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Yorio, Jeffrey Thomas, Patricia S. Fox, Richard Wayne Joseph, Roland Bassett, and Michael A. Davies. "Assessment of absolute lymphocyte count (ALC) as a predictor of progression-free survival (PFS) and overall response rate (ORR) in metastatic melanoma (MM) patients (pts) treated with high-dose interleukin-2 (HD IL-2)." Journal of Clinical Oncology 31, no. 15_suppl (May 20, 2013): 9096. http://dx.doi.org/10.1200/jco.2013.31.15_suppl.9096.
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9096 Background: HD IL-2 is an approved immunotherapy that can achieve durable cures in MM pts. Due to toxicity and low ORR, identification of predictors of clinical benefit would enhance pt selection and outcomes with HD IL-2. Recent research identified a positive correlation for ALC ≥ 1000 (either at baseline or at dose 3) with OS among MM pts treated with the immunotherapy agent ipilimumab. We tested the hypothesis that ALC (≥ 1000) or other hematological parameters correlates with clinical benefit from HD IL2. Methods: Results of hematologic testing in patients (n=98) treated with HD IL2 at MD Anderson Cancer Center were collected, including absolute levels of neutrophils (ANC), lymphocytes (ALC), monocytes (AMC), eosinophils (AEC), and platelets (APC) at baseline, after cycle 1 (C1), and after cycle 2 (C2) of HD IL-2; changes in each parameter for each interval were also calculated. Hematologic values were assessed as categorical (for ALC, ≥ 1000 Yes/No; other parameters, above upper limit of normal [ULN] Yes/No) and continuous variables. Associations between these parameters and PFS and ORR were analyzed. Results: ALC was≥ 1000 in 75 pts (76%) at baseline, in 81 (83%) after C1, and in 80 of 86 pts (93%) after completion of C2 of HD IL-2. PFS was not significantly associated with ALC ≥ 1000 at baseline (HR 0.69, p=0.13), after C1 (HR 1.32, p=0.33), or after C2 (HR 1.01, p=0.98). ALC ≥ 1000 at each timepoint was not significantly associated with ORR or OS. There was no significant difference in the change in ALC with HD IL2 treatment among responders versus non-responders. Among baseline hematological factors, APC > ULN was significantly associated with PFS (p=0.001), but it was rare (2/98 patients). Exploratory analyses identified significantly shorter PFS for patients with baseline APC > 300 (11%, HR 2.75, p=0.002). Analysis of hematologic factors as continuous values identified significant associations with PFS for AMC (HR 2.42, p=0.03) and AEC (HR 1.73, p=0.009) after C2. Conclusions: ALC ≥ 1000 did not correlate with PFS, ORR, or OS with HD IL-2 therapy in this cohort of metastatic melanoma pts.
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Alali, Muayad, Cassandra Prather, Lara A. Danziger-Isakov, Michelle L. Kussin, Malak Khalifeh, Nashwan Al Othman, and Allison H. Bartlett. "Absolute Monocyte Count as Early and Safe Marker for Antibiotic Cessation in Febrile Neutropenia Without Etiology in Pediatric Oncology Patients." Journal of Pediatric Hematology/Oncology 45, no. 6 (June 26, 2023): e702-e709. http://dx.doi.org/10.1097/mph.0000000000002696.
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Background: There is no practice standard regarding antibiotic duration in children with cancer and unexplained febrile neutropenia (FN). We hypothesized that absolute monocyte count (AMC) and absolute phagocyte count (APC= ANC + AMC + bands) are more sensitive, earlier, and safe markers of antibiotic cessation compared with absolute neutrophil count (ANC). Methods: A retrospective review of FN episodes (FNEs) in pediatric oncology patients was conducted between 2009 and 2016. Included patients were afebrile for 24 hours and without an identified infectious source at antibiotic cessation. Primary endpoints, including recurrent fever, readmission, bloodstream infection, microbiologically documented infection, and adverse outcomes, were assessed 10 days after antibiotic cessation and compared among different bone marrow recovery parameters (ANC, AMC, APC). Secondary endpoints included length of FN stay, antibiotic-free days, and cost. Results: Three hundred ninety-one FNEs in 235 patients were included. Three groups were compared based on ANC (cells/μL) at the time of antibiotic cessation: < 200 in 102 (26%), 200 to 500 in 111 (28%), and >500 in 178 (46%). No statistically significant differences in primary endpoints were identified among the 3 ANC groups; however, a trend toward unfavorable outcomes in the ANC ≤200 cells/μL group compared with the ANC >200 cells/μL was observed. Primary endpoints based on AMC >100 cells/μL at the time of antibiotic cessation showed statistically significant favorable outcomes compared AMC ≤100 cells/μL (80%, 88%, 90%, 89%, and 93% risk reduction in recurrent fever, readmission, new bloodstream infection, new microbiologically documented infection, and adverse events, respectively). Similar favorable results were seen when APC >300 cells/μL was used as a threshold for antibiotic cessation. The median length of stay for FN if discharged when AMC >100 cells/μL was 3 days shorter and associated with fewer unfavorable outcomes, thus resulting in fewer hospital days, fewer antibiotic days, and decreased cost. Conclusion: Our results suggest that AMC >100 cells/μL (regardless of ANC) or APC >300 cells/μL may be safe thresholds for empiric antibiotic cessation and result in reduced unfavorable clinical outcomes within 10 days postdischarge, reduced antibiotic days of therapy and reduced health care costs. Further prospective studies are needed to validate AMC as an accurate surrogate marker for antibiotic cessation in FNEs in children with cancer.
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Alali, Muayad. "#32 Pediatric Febrile Neutropenia with Low Risk of Systemic Infection: When Is It Safe to Stop Antibiotics?" Journal of the Pediatric Infectious Diseases Society 11, Supplement_1 (June 14, 2022): S1—S2. http://dx.doi.org/10.1093/jpids/piac041.003.
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Abstract Background There are no standard practices about antibiotics duration in unexplained stable febrile neutropenia (FN). Absolute neutrophile count (ANC) recovery has been used clinically to represent bone marrow recovery (BMR) but data about safe ANC threshold for antibiotic cessation (AC) and discharge is still unknown. Other markers should be considered. We hypothesized that absolute monocyte count (AMC), and absolute phagocyte count (APC= ANC + AMC+ bands) are more sensitive, and an earlier safe marker of AC compared with ANC Method A retrospective review was performed for FN episodes (FNEs) at a single institution (2009 and 2016) in pediatric oncology patients. Eligible FNEs who were a febrile for 24 hours and had no documented infectious source identified at AC and did not receive chemotherapy 10 days following AC. Ten-day post-AC primary end points (recurrent fever, readmission, blood stream infection BSI, microbiology documented infection MDI, and adverse outcomes) were assessed and compared among different BMR parameters (ANC vs AMC vs APC). Secondary end point compares length of stay, antibiotics free days and cost-effectiveness among different BMR markers. Results Eligible FNEs were 391 at time of AC in 235 patients. Three groups were compared based on ANC (cells/μL) at the time of AC : < 200 in 102 (26%), 200-500 in 111 (28%), and >500 /uL in 178 (46%) with an overall ten-day recurrent fever rate 7.4% (29/391). No significant differences in primary end point outcomes rates were identified among 3 ANC groups (11.7%,, 6.3% and 5.6% respectively, P=0.06) and readmission (10%,4.5%, 4%, respectively; P=0.05)(Table 1), however, there is a trend toward unfavorable outcomes in ANC< 200 group compared with ANC>200. In subset analysis in group of ANC>200, favorable outcomes in (ANC>200 with AMC>100) than in the (ANC>200 with AMC<100) group. There was significant risk reduction in primary end points (75% in recurrent fever, 85% readmission, 87% in BSI, 88% in MDI and 87% in adverse events in (ANC>200 with AMC>100) compared with (ANC>200 with AMC<100/uL) group. More importantly, primary end points based on AMC>100 /uL as BMR for AC, regardless ANC values, showed significant favorable outcomes compared AMC<100 /uL. There is 80%, 88, 90%, 89%, and 93% risk reduction in end points recurrent fever, readmission BSI, MDI, and adverse outcomes respectively. Similar favorable results were seen when APC>300 used as threshold for AC (Table 2, 3). Median of length of stay of FN was 3 days shorter using AMC >100/uL for BMR compared with any threshold of ANC (P< 0.01) and decrease overall FN cost stay (P< 0.01). Conclusion Our results suggest that AMC > 100 /uL regardless of ANC/uL, or APC> 300 or ANC>200 with AMC>100/uL all are a safe thresholds for empiric AC. Further prospective studies are needed to validate AMC as accurate surrogate for AC in FN children with cancer.
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Fearnhead, N. S. "The ABC of APC." Human Molecular Genetics 10, no. 7 (April 1, 2001): 721–33. http://dx.doi.org/10.1093/hmg/10.7.721.
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Booth, JL, ES Duggan, VI Patel, J. Metcalf, M. Langer, KM Coggeshall, and A. Braun. "ID: 106: ALVEOLAR ESCAPE BY BACILLUS ANTHRACIS SPORES DOES NOT REQUIRE A CARRIER CELL AND IS NOT ALTERED BY LETHAL TOXIN." Journal of Investigative Medicine 64, no. 4 (March 22, 2016): 960.2–961. http://dx.doi.org/10.1136/jim-2016-000120.101.
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RationaleThe lung is the entry site for Bacillus anthracis in inhalation anthrax, the most deadly form of the disease. B. anthracis spores must escape from the alveolus, pass to the regional lymph nodes, germinate and enter the circulatory system as vegetative bacteria to cause systemic disease. Of the resident lung cells, three have been reported to take up B. anthracis spores: the antigen presenting cells (APC) alveolar macrophages and dendritic cells, and alveolar epithelial cells (AEC). Also, B. anthracis produces the exotoxins lethal factor and protective antigen (PA) which combine to form lethal toxin (LT), a metalloproteinase important in pathogenicity. The roles of carrier cells and the effects of B. anthracis toxins in escape of spores from the alveolus are unclear, especially in humans.MethodsWe employed a human lung organ culture model and a human A549 alveolar epithelial cell culture model, along with fluorescent confocal imaging to quantitate spore partitioning between APC and AEC, and the effects of B. anthracis LT and PA on this process. Cell types were distinguished by positive staining for HLA-DR (APC) and cytokeratin (AEC).ResultsWe found that spores progressed through the lung slice over time, and that spore movement was not dependent on cell internalization. Both free and cell-associated spores moved through slices between 2 and 48 hrs of incubation. However, partitioning of spores between AEC, APC, and the extracellular space did not significantly change over this time. After 2 hrs, 4.7% of spores were in APC; 13.8% in AEC; and 81.5% were not cell-associated. By 48 hrs, 2.9% were in APC; 12.7% were in AEC; and 84.4% were not cell-associated. Spores also internalized in a non-uniform manner, with more variable spore internalization into AEC than into APC. At all incubation times, the majority of cell-associated spores were in AEC, not in APC. PA and LT did not affect transit of the spores through the lung tissue or the distribution of spores into AEC and APC. In A549 cells, spore internalization increased significantly after 24 hrs incubation. However, there was no statistically consistent effects of PA or LT on spore internalization in A549 cells.ConclusionsOverall, our results support a “Jailbreak”-like model of spore escape from the alveolus that involves transient passage of spores, although this occurs through intact AEC. However, subsequent transport of spores by APC from the lung to the lymph nodes may occur.
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Bell, Stephen A. J. "ANPC member profile for APC." Australasian Plant Conservation: journal of the Australian Network for Plant Conservation 29, no. 1 (August 2020): 38–39. http://dx.doi.org/10.5962/p.373844.
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Chang, Joanne T., Jihyoun Jeon, Hutcha Sriplung, Seesai Yeesoonsang, Surichai Bilheem, Laura Rozek, Imjai Chitapanarux, et al. "Temporal Trends and Geographic Patterns of Lung Cancer Incidence by Histology in Thailand, 1990 to 2014." Journal of Global Oncology, no. 4 (December 2018): JGO.18.00013. http://dx.doi.org/10.1200/jgo.18.00013.
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Purpose Lung cancer is one of the most common cancers worldwide and in Thailand. We characterize and forecast region-specific patterns of lung cancer incidence by histology and sex. Methods We analyzed lung cancer incidence trends in Thailand by histology (adenocarcinoma [AdC]; squamous cell carcinoma [SCC]; and large-cell, small-cell, and other carcinomas) from 1990 to 2014 in four cancer registries in three regions (north, Chiang Mai Province and Lampang Province; northeast: Khon Kaen Province; south: Songkhla Province). Annual percent change (APC) was calculated to quantify the incidence rate trends using joinpoint regression. Age-period-cohort models were used to examine the temporal trends of AdC and SCC by age, calendar year, and birth cohort. We projected the incidence of AdC and SCC up to 2030 using three independent approaches: joinpoint, age-period-cohort, and Nordpred models. Results AdC incidence significantly increased from 1990 to 2012 in Chiang Mai males (APC, 1.3%), Songkhla males from 2004 to 2014 (APC, 2.5%), Songkhla females from 1990 to 2014 (APC, 5.9%), and Khon Kaen females from 2005 to 2014 (APC, 3.1%). Conversely, SCC incidence significantly decreased from 1990 to 2012 in Chiang Mai males and females (APC, −1.2% and −4.8%, respectively), Lampang males and females from 1993 to 2014 (APC, −5.4% and −5.2%, respectively), and Songkhla females from 1990 to 2014 (APC, −2.1%). In general, trends of AdC and SCC correlated more with birth cohort than with calendar year. Three projection models suggested that incidence rates of AdC in Songkhla may continue to increase until 2030. Conclusion Temporal trends of lung cancer by histology varied among regions in Thailand. Reduction of lung cancer incidence in Thailand likely will require prevention strategies tailored to each specific region.
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Abboud, Yazan, Madison Fraser, Imran Qureshi, and Kaveh Hajifathalian. "Early-Onset Colorectal Cancer: Are Neuroendocrine Tumors or Adenocarcinomas the Culprit? Analysis of the Largest U.S. Cancer Incidence Database, 2001–2020." Journal of Clinical Medicine 13, no. 4 (February 15, 2024): 1098. http://dx.doi.org/10.3390/jcm13041098.
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(1) Background: While prior data showed an increasing incidence of colorectal cancer (CRC) in young adults, the contribution of adenocarcinoma (ADC) and neuroendocrine tumors (NETs) to this trend is not well studied. Therefore, we conducted a comparative analysis of the incidence rates and time trends of colorectal ADC and NETs in young adults (aged 24–54) using the United States Cancer Statistics (USCS) database. (2) Methods: Age-adjusted CRC incidence rates between 2001 and 2020 were calculated and categorized by sex, histopathology, and stage at diagnosis. Annual percentage change (APC) and average APC (AAPC) were computed via joinpoint regression utilizing weighted Bayesian information criteria to generate the simplest trend. Pairwise comparative analysis of ADC and NETs was conducted using tests of identicalness and parallelism. (3) Results: In this study, 514,875 patients were diagnosed with early-onset-CRC between 2001 and 2020 (54.8% men). While CRC incidence was significantly increased, including both ADC (448,670 patients) and NETs (36,205 patients), a significantly greater increase was seen for NETs (AAPC = 2.65) compared to ADC (AAPC = 0.91), with AAPC difference = 1.73 (p = 0.01) and non-identical non-parallel trends (p-values < 0.001). This was most notable in males (AAPC difference = 1.81, p = 0.03) and for early-stage tumors (AAPC difference = 3.56, p < 0.001). (4) Conclusions: Our study, covering ~98% of the U.S. population provides the first comparative analysis of early-onset CRC histopathological subtypes, showing that the rate of increase of NETs in young adults is much greater than that of ADC. Given that patients with NETs with malignant behavior can experience significant mortality, our findings are importance, highlighting the rapidly increasing NET incidence in young adults and encouraging early screening that can improve outcomes.
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Omar, Mohd Shah Fazly, Syirah Nazirah Mohd Tajuddin, Sabariah Md Noor, and Zainina Seman. "Full Blood Count Parameters in COVID-19 Patients With Disease Severity, Patient Outcome and Vaccination Status." LAB MEDICINE AND RESEARCH IN PATHOLOGY 19, s16 (December 16, 2023): 16–23. http://dx.doi.org/10.47836/mjmhs.19.s16.4.
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Introduction: A link between full blood count (FBC) parameters with the severity and prognosis of individuals with coronavirus disease 2019 (COVID-19) infection is shown. We aim to identify changes in FBC parameters depending on patients’ characteristics, the severity of the disease and vaccination status. Methods: A cross-sectional retrospective laboratory study is done on 208 respondents who were selected from February 2021 to December 2022 in the Pathology Department of the Tuanku Ja’afar Hospital in Negeri Sembilan. All patients are confirmed COVID-19 positive by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of pharyngeal and nasal swab specimens. Patients are further classified based on their COVID clinical stages, severity, vaccination status and outcome. The statistical data are analysed using IBM SPSS version 27. Results: Severe patients have significantly lower absolute lymphocyte count (ALC), absolute monocyte count (AMC), absolute eosinophil count (AEC) and absolute basophil count (ABC) but higher mean platelet volume (MPV), absolute neutrophil count (ANC), neutrophil to lymphocyte ratio (NLR) and immature granulocytes (IG) compared to non-severe patients (p < 0.05). Similar findings are seen among non-survivors (p < 0.05). Fully vaccinated patients have significantly lower NLR and MPV but higher ALC, AMC, AEC and ABC than unvaccinated or partially vaccinated patients (p < 0.05). Conclusion: Selected FBC parameters of COVID-19 patients (platelets, ANC, NLR, MPV, ALC, AMC, AEC, and ABC) are significantly different depending on patients’ severity, outcome and vaccination status. These results might give a clear insight for clinicians to anticipate the severity and outcome of patients based on the patient’s FBC parameters.
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Ormiston, Cameron K., Wayne R. Lawrence, Saanie Sulley, Meredith S. Shiels, Emily A. Haozous, Catherine M. Pichardo, Erica S. Stephens, et al. "Trends in Adolescent Suicide by Method in the US, 1999-2020." JAMA Network Open 7, no. 3 (March 29, 2024): e244427. http://dx.doi.org/10.1001/jamanetworkopen.2024.4427.
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ImportanceAdolescent suicide in the US is a major public health problem, yet temporal trends in suicide methods by demographics are understudied.ObjectiveTo examine national trends in suicide mortality by method (firearm, poisoning, hanging and asphyxiation, and all other means) from 1999 to 2020 by demographic characteristics.Design, Setting, and ParticipantsThis serial cross-sectional study used national death certificate data of adolescent (aged 10-19 years) suicide decedents compiled by the National Center for Health Statistics from January 1, 1999, to December 31, 2020. Data analysis was performed from April 1, 2023, to July 9, 2023.ExposuresAge, sex, and race and ethnicity.Main Outcomes and MeasuresTrends in age-standardized mortality rates and average annual percent change (AAPC) in rates were estimated by age, sex, and race and ethnicity for each suicide method.ResultsThis study assessed data from 47 217 adolescent suicide decedents. From 1999 to 2020, suicide by firearm (AAPC, 1.0; 95% CI, 0.1-1.9), poisoning (AAPC, 2.7; 95% CI, 1.0-4.4), hanging and asphyxiation (AAPC, 2.4; 95% CI, 0.2-4.6), and other means (AAPC, 2.9; 95% CI, 1.2-4.6) increased. Rapidly increasing rates were observed among female adolescents for poisoning (AAPC, 4.5; 95% CI, 2.3-6.7) and hanging and asphyxiation (AAPC, 5.9; 95% CI, 5.0-6.8) suicides. From 2007 to 2020, firearm suicides sharply increased among female (annual percent change [APC], 7.8; 95% CI, 6.0-9.5) and male (APC, 5.3; 95% CI, 4.3-6.3) adolescents. Firearm suicide rates increased among Black adolescents from 2012 to 2020 (APC, 14.5; 95% CI, 9.7-19.5), Asian and Pacific Islander adolescents from 2008 to 2020 (APC, 12.0; 95% CI, 9.7-14.5), American Indian and Alaska Native adolescents from 2014 to 2020 (APC, 10.6; 95% CI, 2.6-19.3), and Hispanic or Latino adolescents from 2011 to 2020 (APC, 10.2; 95% CI, 6.3-13.8). During the study period, Black adolescents had the highest average increase in hanging and asphyxiation suicides (AAPC, 4.2; 95% CI, 3.2-5.2). From 2011 to 2020, poisoning suicide deaths increased (APC, 12.6; 95% CI, 8.5-16.7) among female adolescents.Conclusions and RelevanceSuicide rates increased across all methods from 1999 to 2020. Differences were noted by sex, age, and race and ethnicity. Increasing suicide rates among racial and ethnic minoritized youth are especially concerning, and effective prevention strategies are urgently needed.
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Golderman, Valery, Shany G. Gofrit, Nicola Maggio, Orna Gera, Alexandra Gerasimov, Dar Laks, Joab Chapman, and Efrat Shavit-Stein. "A Novel Highly Sensitive Method for Measuring Inflammatory Neural-Derived APC Activity in Glial Cell Lines, Mouse Brain and Human CSF." International Journal of Molecular Sciences 21, no. 7 (March 31, 2020): 2422. http://dx.doi.org/10.3390/ijms21072422.
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Background: Neural inflammation is linked to coagulation. Low levels of thrombin have a neuroprotective effect, mediated by activated protein C (APC). We describe a sensitive novel method for the measurement of APC activity at the low concentrations found in neural tissue. Methods: APC activity was measured using a fluorogenic substrate, Pyr-Pro-Arg-AMC, cleaved preferentially by APC. Selectivity was assessed using specific inhibitors and activators. APC levels were measured in human plasma, in glia cell lines, in mice brain slices following mild traumatic brain injury (mTBI) and systemic lipopolysaccharide (LPS) injection, and in cerebrospinal fluid (CSF) taken from viral meningoencephalitis patients and controls. Results: Selectivity required apixaban and alpha-naphthylsulphonylglycyl-4-amidinophenylalanine piperidine (NAPAP). APC levels were easily measurable in plasma and were significantly increased by Protac and CaCl2. APC activity was significantly higher in the microglial compared to astrocytic cell line and specifically lowered by LPS. Brain APC levels were higher in posterior regions and increased by mTBI and LPS. Highly elevated APC activity was measured in viral meningoencephalitis patients CSF. Conclusions: This method is selective and sensitive for the measurement of APC activity that significantly changes during inflammation in cell lines, animal models and human CSF.
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Stefanski, Casey D., Anne Arnason, Sara Maloney, Janna Kotsen, Elizabeth Powers, Jian-Ting Zhang, and Jenifer R. Prosperi. "APC Loss Prevents Doxorubicin-Induced Cell Death by Increasing Drug Efflux and a Chemoresistant Cell Population in Breast Cancer." International Journal of Molecular Sciences 24, no. 8 (April 21, 2023): 7621. http://dx.doi.org/10.3390/ijms24087621.
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Chemoresistance is a major health concern affecting cancer patients. Resistance is multifactorial, with one mechanism being the increased expression of ABC transporters (such as MDR1 and MRP1), which are drug efflux transporters capable of preventing intracellular accumulation of drugs and cell death. Our lab showed that the loss of Adenomatous Polyposis Coli (APC) caused an intrinsic resistance to doxorubicin (DOX), potentially through an enhanced tumor-initiating cell (TIC) population and the increased activation of STAT3 mediating the expression of MDR1 in the absence of WNT being activated. Here, in primary mouse mammary tumor cells, the loss of APC decreased the accumulation of DOX while increasing the protein levels of MDR1 and MRP1. We demonstrated decreased APC mRNA and protein levels in breast cancer patients compared with normal tissue. Using patient samples and a panel of human breast cancer cell lines, we found no significant trend between APC and either MDR1 or MRP1. Since the protein expression patterns did not show a correlation between the ABC transporters and the expression of APC, we evaluated the drug transporter activity. In mouse mammary tumor cells, the pharmacological inhibition or genetic silencing of MDR1 or MRP1, respectively, decreased the TIC population and increased DOX-induced apoptosis, supporting the use of ABC transporter inhibitors as therapeutic targets in APC-deficient tumors.
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Sun, Xian-He, and Dawei Wang. "APC." ACM SIGMETRICS Performance Evaluation Review 40, no. 2 (October 8, 2012): 125–30. http://dx.doi.org/10.1145/2381056.2381082.
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Bienz, Mariann. "APC." Current Biology 13, no. 6 (March 2003): R215—R216. http://dx.doi.org/10.1016/s0960-9822(03)00152-0.
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Onrat, Serap Tutgun, and Nurhan Dogan. "Evaluation of Congenital and Chromosomal Anomalies Mortality in Turkey by Joinpoint Regression Analysis." Global Journal Of Epidemiology and Public Health 6 (June 15, 2022): 51–57. http://dx.doi.org/10.12974/2313-0946.2021.06.01.4.
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Congenital anomalies (CAs) represents one of the main cause of fetal death, infant mortality and morbidity, and long-term disability. This study aims that it was to analyze the mortality trends of Congenital and Chromosomal Anomalies (CCAs) mortality in Turkey. This population-based observational study covers nine years in Turkey. CCAs mortality data was reported from the Turkish Statistical Institute death database by gender and age. Age-standardized mortality rates per 100,000 population were calculated by direct standardization using the WHO Reference Population. Average annual percent change (AAPC), annual percent change (APC), and 95% confidence interval (CI) were computed using the joinpoint regression analysis. Joinpoint Regression analysis results showed a significant trend for overall CCA-type mortality over the entire observation period (AAPC=3.9%, 95% CI:1.4 to 6.4). A significant increase in the mortality rate of nervous system (in male: APC:7.6%, 95% CI: 2.2 to 13.4; in female: APC:6.6%, 95% CI:2.6 to 10.7) and circulatory system (in male: APC:4.6%, 95% CI:1.5 to 7.8; in female: APC:3.4%, 95% CI:0.8 to 6.1) were observed in both gender during the study period (p<0.001). Congenital anomalies in Turkey are a major cause of fetal and neonatal death, however, most of the anomalies can be preventable or treatable.
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Stefanski, Casey D., Janna Kotsen, Amy Bernard, and Jenifer Prosperi. "Abstract 3246: APC loss prevents doxorubicin-induced cell death by effluxing drug and increasing a chemoresistant cell population." Cancer Research 82, no. 12_Supplement (June 15, 2022): 3246. http://dx.doi.org/10.1158/1538-7445.am2022-3246.
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Abstract Chemoresistance is a leading cause of breast cancer related deaths. Therefore, understanding the molecular basis for chemoresistance is essential for novel therapeutic advancement and improving patient outcome. The Adenomatous Polyposis Coli (APC) tumor suppressor is lost in up to 70% of sporadic breast cancer; however, little is known about how APC loss contributes to chemoresistance. Using mammary tumor cells isolated from the ApcMin/+ mouse crossed to the Polyoma middle T antigen (PyMT) transgenic model, we made the novel observation that APC loss decreased doxorubicin (DOX) induced apoptosis. Therefore, we examined the mechanisms contributing to DOX resistance with APC loss to identify combination therapy options. We previously showed that APC loss in MMTV-PyMT;ApcMin/+ cells activated signal transducer and activator of transcription 3 (STAT3) thereby increasing the expression of the drug efflux pump, multidrug resistance protein 1 (MDR1). ATP-binding cassette (ABC) transporters, such as MDR1, are well established to contribute to drug resistance through exporting drugs from the cell. Furthermore, tumor initiating cells (TICs) have increased expression of ABC transporters and are known to be chemoresistant. We showed that MMTV-PyMT;ApcMin/+ cells have an increased TIC population. In addition, decreased intracellular DOX accumulation was observed in APC-deficient cells suggesting enhanced drug efflux. To investigate this decreased intracellular DOX accumulation, we measured the expression and activity of the drug export pumps, MDR1 and multidrug resistance protein 1 (MRP1). Using a small molecule inhibitor (Valspodar), we found that MDR1 inhibition restored the DOX-induced cleaved caspase 3 expression, demonstrating that MDR1 contributes to DOX resistance. MDR1 inhibition also increased the intracellular DOX accumulation in the APC-deficient cells and reduced the TICs. Genetic manipulation to silence MRP1 also increased DOX-induced apoptosis, increased DOX accumulation, and decreased the TICs in MMTV-PyMT;ApcMin/+ cells. To target both MDR1 and MRP1, a small molecule inhibitor (Reversan) was used to see if affecting both would offer more benefit. We again found that Reversan restored DOX sensitivity in MMTV-PyMT;ApcMin/+ cells through increasing DOX accumulation and decreasing TICs. Future studies include using a panel of human breast cancer cell lines to determine correlation of APC expression and DOX sensitivity. In addition, we will also evaluate patient tumor protein lysates for APC, MDR1, and MRP1 expression, followed by correlation studies to determine whether expression of APC inversely correlates with MDR1 or MRP1. Taken together, APC loss mediates DOX resistance via increasing DOX export and the TIC population demonstrating the potential use of combination therapy to overcome chemoresistance. Citation Format: Casey D. Stefanski, Janna Kotsen, Amy Bernard, Jenifer Prosperi. APC loss prevents doxorubicin-induced cell death by effluxing drug and increasing a chemoresistant cell population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3246.
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Zeng, Q., E. Vogtmann, M. Jia, M. Parascandola, Q. Feng, and X. Zou. "Tobacco Smoking and Trends in Histological Subtypes of Female Lung Cancer at The Cancer Hospital of The Chinese Academy of Medical Sciences Over 13 Years." Journal of Global Oncology 4, Supplement 2 (October 1, 2018): 29s. http://dx.doi.org/10.1200/jgo.18.51200.
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Background: Smoking among Chinese women accounts for a small proportion, but the incidence and mortality rates of female lung cancer is increasing in recent years. Studies found that there were changes in histologic subtypes of lung cancer patients in China. Aim: This study investigated the tobacco smoking and trends in histologic subtypes of female lung cancer in a cancer hospital in China. Methods: Demographic, smoking history and histologic information about female lung cancer patients diagnosed or treated from 2000 to 2012 was collected from Cancer Hospital, Chinese Academy of Medical Science (CHCAMS). Trends of histologic subtypes calculated with annual percentage change (APC). The distribution differences of adenocarcinoma (ADC), squamous cell carcinoma (SCC), small cell lung cancer (SCLC) and the other subtypes between smokers and nonsmokers were calculated by 7th AJCC cancer staging. Results: Totally of 5,870 female cases of lung cancer, including 630 with history of smoking and 5,240 without, were analyzed. The number of female lung cancer patients increased from 509 (2000-2002) to 1744 (2012-2013). The main histologic type of lung cancer was adenocarcinoma (ADC) (72.93%), followed by small cell lung cancer (SCLC) (11.06%), squamous cell carcinoma (SCC) (8.38%) and the other (7.63%). Among smokers, the proportion of SCC decreased from 40.5% to 23.7% (APC = -11.68%, P = 0.005), however, the ADC increased from 35.7% to 50.7% (APC = 8.63%, P = 0.009). In nonsmokers, the ADC was 76.1%, and SCC was 5.9%. ADC increased from 63.1% to 80.6% (APC = -21.33%, P = 0.006), SCC decreased from 13.6% to 4.5% (APC = 3.86%, P = 0.016). Among squamous cell carcinoma, the cases with history of smoking were more likely diagnosed at early stages (I/II: 47.1%) than those at late stages (III, 34.3%; IV, 18.6%). Conclusion: The number of female lung cancer patients was increased in CHCAMS by year of diagnosis. In both smoking and nonsmoking cases, the proportion of adenocarcinoma was increasing. Among the squamous cell carcinoma, smokers seem to find in early stages.
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Elice, Francesca, Louis Fink, Guido J. Tricot, Teresa J. Milner, Bart Barlogie, and Maurizio Zangari. "Acquired Resistance to Activated Protein C (aAPCR) Is Associated with Increased Risk of Deep Vein Thrombosis in Multiple Myeloma." Blood 106, no. 11 (November 16, 2005): 3484. http://dx.doi.org/10.1182/blood.v106.11.3484.3484.
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Abstract Non factor V Leiden APC resistance (aAPCR) has been described in cancer patients and found to be associated with an increased risk of deep venous thrombosis (DVT). We analyzed the incidence and clinical impact of APC resistance in a large group of multiple myeloma patients. A total of 1178 myeloma patients were tested for APC resistance using an aPTT-based assay in the presence of excess of factor V-deficient plasma and the ratio with or without APC was calculated (≤ 2.00 was considered abnormal). PCR amplification of genomic DNA was used to detect Factor V Leiden. Abnormal APC resistance was found in 109 patients (9.3%), 83 of those were tested for factor V Leiden, 31 had the mutation and 52 (63%) did not have it. Analyzing a subgroup of 254 chemotherapy naïve patients, APC ratio was abnormal in 11% of patients and two third of them were not carriers of factor V Leiden mutation. The presence of aAPC resistance was associated with an increased risk for DVT: 27.9% in patients with aAPCR vs.12.3% in the others (P = 0.008); 22.6% in patients with factor V Leiden mutation. In 32 patients with abnormal aAPCR, the test was repeated: 31/32 patients normalized their APC ratio in sequential testing. Correlation between myeloma baseline markers (serum and urine M-component, beta2-microglobulin, CRP, IL-6), response to treatment and APC activity were studied. In this analysis active disease emerged as the most important factor associated with aAPCR, as 19 patients with normalization of the APC ratio had a concomitant clinical response to therapy. We concluded that aAPCR is a transient finding in myeloma patients that showed a significant correlation with development of DVT.
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Barbosa, Isabelle Ribeiro, Íris do Céu Clara Costa, María Milagros Bernal, and Dyego Leandro Bezerra De Souza. "TENDÊNCIA DAS TAXAS DE MORTALIDADE PELAS DEZ PRINCIPAIS CAUSAS DE ÓBITOS POR CÂNCER NO BRASIL, 1996-2012." Revista Ciência Plural 2, no. 1 (August 30, 2016): 03–16. http://dx.doi.org/10.21680/2446-7286.2016v2n1id8886.
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Objetivo: analisar a tendência das taxas de mortalidade pelas dez principais causas de óbitos por câncer no Brasil. Metodologia: Estudo de série temporal com dados do Sistema de Informação sobre Mortalidade (SIM) sobre óbitos por câncer ocorridos no período de 1996 a 2012. Foi empregada a regressão Joinpoint. Resultados: Apresentaram tendências de aumento no sexo masculino as taxas de mortalidade pelos cânceres de próstata (Variação percentual anual- APC=1,3%; IC95% 0,6-1,9),de fígado (APC=1,7%; IC95% 1,2-2,1) e de cólon e reto (APC=1,8%; IC95% 1,4-2,2). No feminino, apresentaram aumento as taxas dos cânceres de pulmão (AAPC= 2,4%; IC95% 1,9-2,9) e mama (APC=0,5%; IC95% 0,1-1,0). As taxas de mortalidade por cânceres de encéfalo e pâncreas aumentaram em ambos os sexos. Conclusões: Foram observados padrões distintos nas tendências de mortalidade segundo sexos, para os cânceres de pulmão, fígado e cólon, além da tendência de aumento para os cânceres de próstata e mama.
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Gordon, Alasdair. "APC mutations." Nature 358, no. 6384 (July 1992): 288. http://dx.doi.org/10.1038/358288a0.
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Pötzsch, B., and I. Witt. "APC-Resistenz." Hämostaseologie 22, no. 02 (2002): 67–70. http://dx.doi.org/10.1055/s-0037-1619539.
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ZusammenfassungDie APC-Resistenz stellt in der Bevölkerung der westlichen Industrieländer mit kaukasischer Abstammung den häufigsten, bisher bekannten angeborenen und zur Thrombose führenden Risikofaktor dar. Im Plasma von betroffenen Personen ist die antikoagulatorische Wirkung von zugesetztem aktiviertem Protein C im Vergleich mit Plasma von Personen ohne diesen Defekt vermindert. In der überwiegenden Mehrzahl der Personen mit APC-Resistenz kann innerhalb des Faktor-V-Gens eine G-A-Punktmutation in Position 1691 nachgewiesen werden. Ein von dieser Mutation betroffener Faktor V verliert durch Austausch der basischen Aminosäure Arginin durch die neutrale Aminosäure Glutamin in Position 506 der schweren Kette des Faktor-V-Moleküls seine potentielle Spaltstelle für aktiviertes Protein C. Im Vergleich mit anderen angeborenen Risikofaktoren ist das Thromboserisiko von heterozygot betroffenen Personen in etwa mit dem von Personen mit einem heterozygoten Protein-C-Mangel vergleichbar. Homozygote Merkmalsträger haben ein etwa 40fach höheres Thromboserisiko. Eine kausale Therapie der APC-Resistenz ist zur Zeit nicht möglich. Zur Vermeidung von Rezidiven nach thromboembolischen Komplikationen wird eine orale Antikoagulation mit einem INR-Zielwertbereich zwischen 2,0 und 3,0 empfohlen, deren Dauer in Abhängigkeit von der klinischen Symptomatik festgelegt wird. Zur Diagnostik der APC-Resistenz stehen verschiedene funktionelle Testverfahren zur Verfügung, die in der Regel als Suchtests eingesetzt werden. Bei positivem oder grenzwertigem Befund wird mit molekulargenetischen Untersuchungsverfahren durch den Nachweis der G 1691 A-Mutation die Diagnose einer APC-Resistenz gesichert. Nur mithilfe der Genanalyse kann sicher zwischen heterozygot und homozygot betroffenen Merkmalsträgern unterschieden werden.
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Alali, Muayad, Allison Bartlett, Lara Danziger-Isakov, and Lara Danziger-Isakov. "64. Absolute Monocyte Count (AMC) as Early and Safe Marker for Discharge in Low-risk Pediatric Febrile Neutropenia with Cancer." Open Forum Infectious Diseases 8, Supplement_1 (November 1, 2021): S150—S151. http://dx.doi.org/10.1093/ofid/ofab466.266.
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Abstract Background Fever with neutropenia (FN) is common and the timing of antibiotic cessation in patients without an identified fever source is uncertain. Absolute neutrophile count (ANC) recovery has been used clinically to represent bone marrow recovery (BMR) but other options should be considered. We hypothesized that absolute monocyte count (AMC), and absolute phagocyte count (APC) are more sensitive, and an earlier safe marker of antibiotic cessation (AC) compared with ANC Methods A retrospective review was performed for FN episodes (FNEs) at UCM Comer Children’s Hospital between 2009 and 2016 in pediatric oncology patients. Eligible FNEs who were a febrile for 24 hours, had no bacterial source identified at time of AC, and did not receive chemotherapy 10 days following AC. Ten-day post-AC outcomes, length of stay and cost were assessed and compared among different BMR parameters (ANC vs AMC). Results A total of 928 FN episodes (FNEs) were identified. 391 eligible FNEs occurred in 235 patients. Three groups were compared based on ANC (cells/μL) at the time of AC : < 200 in 102 (26%), 200-500 in 111 (28%), and >500 /uL in 178 (46%) (Figure1) with an overall ten-day recurrent fever rate 7.4% (29/391) and readmission rate of 5.6% (22/391). No significant differences in recurrent fever rates were identified among 3 ANC groups (11.7%, 6.3% and 5.6% respectively, P=0.08) and readmission (10%,4.5%, 4%, respectively; P=0.07)(Table 1).In subset analysis of AMC for each ANC group, patients with AMC >100 at AC have favorable outcomes, regardless ANC threshold (P< 0.01) (Table 1). Median of length of stay of FN was 3 days shorter using AMC >100/uL for BMR compared with any threshold of ANC (P< 0.01) and decrease overall FN cost stay (P< 0.01) (Table 2). Similar analysis show APC >300/uL at time of AC has favourable outcomes and decrease LOS regardless ANC threshold (data not shown here). Conclusion Our results suggest that a AMC > 100 /uL regardless of ANC/uL, is a safe threshold value for empiric AC and discharge. This approach may shorten length of stay, reduce burden of cost of febrile neutropenia cost and potential long term antibiotics side effects. Disclosures Lara Danziger-Isakov, MD, MPH, Ansun (Individual(s) Involved: Self): Scientific Research Study Investigator; Astellas (Individual(s) Involved: Self): Scientific Research Study Investigator; Merck (Individual(s) Involved: Self): Consultant, Scientific Research Study Investigator; Pfizer (Individual(s) Involved: Self): Scientific Research Study Investigator; Shire (Individual(s) Involved: Self): Consultant, Scientific Research Study Investigator; Viracor: Grant/Research Support
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Brinkman, Herm Jan, Erica Sellink, Bas de Laat, and Koen Mertens. "Differential Anticoagulant Effects of Protein S on Vascular Cells and Platelets." Blood 112, no. 11 (November 16, 2008): 2026. http://dx.doi.org/10.1182/blood.v112.11.2026.2026.
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Abstract Background: Protein S is a vitamin K-dependent plasma protein and involved in down-regulation of the coagulation process. Protein S serves as a cofactor of activated protein C (APC) in the proteolytic inactivation of activated factor V and VIII. Protein S is also able to exert its anticoagulant activity independent of APC, e.g. by supporting the anticoagulant activity of tissue factor pathway inhibitor (TFPI). The anticoagulant properties of protein S have been thoroughly characterized by in vitro methods. However, fewer studies focus on protein S function on vascular cells. These studies are limited to model systems employing purified coagulation factors. The aim of this study was to investigate the role of protein S in plasma that is in contact with natural cell membranes, including endothelial cells, smooth muscle cells and platelets. Method: We employed thrombography to evaluate protein S function in 50 % v/v recalcified citrated plasma in the presence of washed platelets, cultured umbilical vein endothelial cells or cultured umbilical artery smooth muscle cells. Since we aimed at a comparison between different cellular membranes, micro-particle free plasma was used. As a reference, we also examined synthetic phospholipid membranes composed of phosphatidyl serine, phosphatidyl choline and phosphatidyl ethanolamine in a 2/6/2 molar ratio. Thrombin activity was measured employing the fluorogenic substrate z-Gly-Gly- Arg-AMC. Protein S activity was probed with CLB-PS13, an antibody directed against the protein S Gla-domain. The APC-independent activity of protein S was assayed in the presence of an inhibitory antibody against protein C. In studies employing phospholipids, thrombin generation was triggered with relipidated tissue factor (TF). Expression of TF on endothelial cells was induced during a 6-hour preincubation with PMA. Results: In the presence of CLB-PS13, the APC-independent activity of protein S became apparent as an increase in peak height in the thrombogram. Lag time, time to peak and area under the curve remained essentially unaffected. Peak height was increased two-fold when examining phospholipids at standard conditions (4 μM lipids and 1 pM TF). This increase in peak height by CLB-PS13 was concentration dependent and complete at 10 μg/ml IgG. Increasing the TF concentration from 1 to 5 pM resulted in loss of the APC-independent activity of protein S on these membranes. APC cofactor activity was assessed in the presence of APC. Addition of APC resulted in inhibition of the thrombin formation on phospholipids with an IC50 of 0.4 nM. CLB-PS13 completely abolished this decrease in thrombin generation up to 50 nM APC, irrespective whether 1 or 5 pM TF was present. Our results are compatible with the view that at high procoagulant stimuli the TFPI-cofactor activity of protein S is abolished. Furthermore, these results show that in plasma APC is completely dependent on protein S. Protein S activity on platelets was studied in the presence of 1 pM TF. As for synthetic lipid membranes and in the absence of APC, CLB-PS13 increased the peak height in the thrombogram. APC inhibited platelet mediated thrombin generation (IC50 = 19 nM), and this inhibition was completely abolished by CLB-PS13. These observations suggest that platelets support both APC-dependent and APC-independent anticoagulant activities of protein S. Thrombography on TF-expressing endothelial cells and smooth muscle cells revealed massive thrombin generation that could not be enhanced with CLB-PS13, indicating that protein S does not contribute to regulation of thrombin formation under these conditions. The APC-dependent activity of protein S became apparent as an abolished inhibition by APC in the presence of CLB-PS13. However, APC proved relatively inefficient in inhibiting thrombin generation on TF-expressing vascular cells (IC50 > 50 nM). Inhibition of TF restored the APC-independent protein S activity. Conclusion: Our results indicate that, in plasma, vascular cells and platelets are able to support the APC-dependent as well as the APC-independent anticoagulant activities of protein S. The APC-independent activity on vascular cells is abolished upon increasing TF expression, while the APC-dependent activity of protein S is limited by the relatively low anticoagulant activity of APC on these cell surfaces. We conclude that protein S activity on cells require relatively high levels of APC or low expression of TF.
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Patel, Sanjay, Christoph Male, Leslie Berry, Lesley Mitchell, and Anthony Chan. "Activated protein C generation is greatly decreased in plasma from newborns compared to adults in the presence or absence of endothelium." Thrombosis and Haemostasis 91, no. 02 (2004): 238–47. http://dx.doi.org/10.1160/th03-06-0372.
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SummaryActivated protein C (APC) generation strongly affects sepsis and thrombosis by inhibition of thrombin generation. However, it is unclear if there are age-related differences in effectiveness of protein C (PC). We studied age effects on plasma APC generation ± endothelium. Defibrinated (Ancrod) plasma (from adults or newborns (umbilical cord)) was recalcified with buffer containing tissue factor ± thrombomodulin (TM) on either plastic or endothelium (HUVEC) at 37oC. Timed subsamples of reaction mixture were taken into either heparin-EDTA or FFRCMK-EDTA solutions and analyzed for APC-PC inhibitor (APC-PCI) or APC-α1antitrypsin (APC-α1AT) by ELISAs. Since heparin converts free APC to APC-PCI, the difference in APCPCI measured in heparin-EDTA and FFRCMK-EDTA samples was equal to free active APC. APC-α2macroglobulin (APC-α2M) was measured as remaining chromogenic activity in heparin-EDTA. Free APC, APC-PCI and APC-α1AT were decreased in newborn compared to adult plasma on plastic. However, APC-α2M made up a larger fraction of inhibitor complexes in newborn plasma. On endothelium, significantly more APC, APC-PCI and APC-α1AT were generated in either plasma compared to that on plastic with excess added TM. APC, APC-PCI and APC-α1AT were also reduced and total APC-α2M increased in newborn plasma on HUVEC. Addition of PC to newborn plasma gave APC generation similar to adult plasma. Thus, free APC, APC-PCI and APC-α1AT generation is reduced in newborn compared to adult plasma with or without endothelium, likely due to reduced plasma PC levels. Endothelium enhances APC generation, regardless of plasma type, possibly because of cell surface factors such as TM, phospholipid and endothelial PC receptor.
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Espana, F., A. Gruber, MJ Heeb, SR Hanson, LA Harker, and JH Griffin. "In vivo and in vitro complexes of activated protein C with two inhibitors in baboons." Blood 77, no. 8 (April 15, 1991): 1754–60. http://dx.doi.org/10.1182/blood.v77.8.1754.bloodjournal7781754.
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In vivo complex formation of activated protein C with protein C inhibitor (APC-PCI) and with alpha 1-antitrypsin (APC-alpha 1AT) following infusion of 0.25 or 1.0 mg APC/kg in 1 hour into baboons was studied using immunoblotting and sandwich enzyme-linked immunosorbent assay (ELISA)s. Before APC infusion, detectable plasma levels (about 30 ng/mL) of APC-alpha 1AT complex were found in the baboon plasma. At the lower APC dose, APC-PCI and APC-alpha 1AT complex levels were 1.4 +/- 0.3 (mean +/- SD) and 0.8 +/- 0.1 microgram/mL after 1 hour of infusion. At the higher APC dose, the APC-PCI level was similar to the APC-alpha 1AT level during the first 30 minutes, but after 1 hour of infusion the APC-alpha 1AT level was higher than the APC-PCI level, reaching 4.1 +/- 1.2 and 2.9 +/- 1.2 microgram/mL, respectively. After 24 hours, complex levels had returned to basal conditions. During infusion of protein C (1.0 mg/kg in 1 hour), both complexes were detected in low concentrations. Following bolus injection of APC, half- lives (t1/2) for APC and APC-PCI and APC-alpha 1AT complexes of 10, 40, and 140 minutes, respectively, were observed. After 1-hour incubation with 2.5 micrograms/mL APC, baboon plasma contained 1.0 +/- 0.2 and 0.8 +/- 0.1 microgram/mL of APC-PCI and APC-alpha 1AT, respectively. Addition of 10 micrograms/mL APC to baboon plasma yielded 2.5 and 2.4 micrograms/mL APC-PCI and APC-alpha 1AT after 1 hour, respectively. Immunoblotting analysis also showed in vivo formation of complexes of APC with an auxilliary inhibitor but not in vitro in citrated plasma. These data show that both PCI and alpha 1AT are physiologic inhibitors of APC and suggest that when PCI is depleted by a high dose of APC, alpha 1AT becomes the major inhibitor of APC.
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Abu-Daabes, Malyuba A., Edrees Abu Zeitoun, and Wafa Mazi. "Competitive Adsorption of Quaternary Metal Ions, Ni2+, Mn2+, Cr6+, and Cd2+, on Acid-Treated Activated Carbon." Water 15, no. 6 (March 10, 2023): 1070. http://dx.doi.org/10.3390/w15061070.
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This paper examined the competitive removal of metal ions from quaternary aqueous solutions containing Ni2+, Mn2+, Cr6+, and Cd2+ using adsorption on both acid-modified and unmodified activated carbon. Activated carbon (AC) was oxidized with nitric acid, both in granular (AGC) and powder (APC) forms, and tested for the competitive adsorption of Ni2+, Mn2+, Cr6+, and Cd2+ from an aqueous solution. Surface oxidation led to a reduction in BET surface area and HK pore width and an increase in the intensities of hydroxyl and carboxyl functional groups for both AGC and APC compared to unmodified activated carbon, AC, as indicated with BET and FTIR analyses. The adsorption capacity of all four metal ions on AC was in the order Ni2+ > Cd2+ > Cr6+ > Mn2+, while it was altered for the two oxidized AGC and APC carbons to be Cr6+ > Ni2+ > Cd2+ > Mn2+. Acid treatment resulted in high selectivity for Cr6+ over all other available ions with a 100% removal efficiency, while it decreased for Ni2+, Cd2+, and Mn2+ compared to AC. This improvement in Cr6+ adsorption is due to its higher ionic potential and smaller size, which results in a faster diffusion and stronger adsorption to the acidic groups located at the pore edges. Therefore, it will repel and hinder other ions from accessing the activated carbon pores. Modeling of the adsorption isotherms with DKR was better than both Freundlich and Langmuir for the competitive ions. DKR showed strong attraction for both Ni2+ and Cd2+ by ion exchange on the AC surface, as indicated by their apparent adsorption energy (E) values. Cr6+ adsorption was found to be by physical adsorption on AC and by ion exchange on both AGC and APC. Mn2+ ions had a very weak attraction to all types of tested activated carbons in the presence of other ions.
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Espana, F., A. Gruber, MJ Heeb, SR Hanson, LA Harker, and JH Griffin. "In vivo and in vitro complexes of activated protein C with two inhibitors in baboons." Blood 77, no. 8 (April 15, 1991): 1754–60. http://dx.doi.org/10.1182/blood.v77.8.1754.1754.
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Abstract In vivo complex formation of activated protein C with protein C inhibitor (APC-PCI) and with alpha 1-antitrypsin (APC-alpha 1AT) following infusion of 0.25 or 1.0 mg APC/kg in 1 hour into baboons was studied using immunoblotting and sandwich enzyme-linked immunosorbent assay (ELISA)s. Before APC infusion, detectable plasma levels (about 30 ng/mL) of APC-alpha 1AT complex were found in the baboon plasma. At the lower APC dose, APC-PCI and APC-alpha 1AT complex levels were 1.4 +/- 0.3 (mean +/- SD) and 0.8 +/- 0.1 microgram/mL after 1 hour of infusion. At the higher APC dose, the APC-PCI level was similar to the APC-alpha 1AT level during the first 30 minutes, but after 1 hour of infusion the APC-alpha 1AT level was higher than the APC-PCI level, reaching 4.1 +/- 1.2 and 2.9 +/- 1.2 microgram/mL, respectively. After 24 hours, complex levels had returned to basal conditions. During infusion of protein C (1.0 mg/kg in 1 hour), both complexes were detected in low concentrations. Following bolus injection of APC, half- lives (t1/2) for APC and APC-PCI and APC-alpha 1AT complexes of 10, 40, and 140 minutes, respectively, were observed. After 1-hour incubation with 2.5 micrograms/mL APC, baboon plasma contained 1.0 +/- 0.2 and 0.8 +/- 0.1 microgram/mL of APC-PCI and APC-alpha 1AT, respectively. Addition of 10 micrograms/mL APC to baboon plasma yielded 2.5 and 2.4 micrograms/mL APC-PCI and APC-alpha 1AT after 1 hour, respectively. Immunoblotting analysis also showed in vivo formation of complexes of APC with an auxilliary inhibitor but not in vitro in citrated plasma. These data show that both PCI and alpha 1AT are physiologic inhibitors of APC and suggest that when PCI is depleted by a high dose of APC, alpha 1AT becomes the major inhibitor of APC.
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Kern, U., and B. Westrich. "Sediment contamination by heavy metals in a lock-regulated section of the River Neckar." Marine and Freshwater Research 46, no. 1 (1995): 101. http://dx.doi.org/10.1071/mf9950101.
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For a lock-regulated reach of the River Neckar at Lauffen, Germany, results from sediment core analysis are presented. It is observed that sediment layers with a high concentration of heavy metals, especially cadmium, are covered by younger, less polluted sediment layers. A principal component analysis separated the parameters measured into three groups: heavy metals from human activities (Cd, Cr, Ni, Pb, Zn), metals from natural sources (Co, Fe, Mn), and inorganic carbon. Within the fine-grained sediment fraction containing particles smaller than 20 μm, a higher concentration of anthropogenic trace metals was found in fine-grained samples than in coarse-grained samples, whereas Co, Fe and Mn showed the opposite tendency. Obviously, this is due to two different sources of fine-grained material: sewage flocs and natural erosion particles. Acid-producing capacity (APC) and acid-neutralizing capacity (ANC) are calculated for both pore water and particulate matter of the sediment. At a depth of 20 cm, APC and ANC are controlled by the sediment matrix. ANC, which is due to calcium carbonate, is 20 times higher than APC, which is predominantly due to reduced sulfur components. Therefore, oxidation of sediment of the River Neckar does not lead to acidification.
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Pikala, Małgorzata, and Monika Burzyńska. "Trends in Mortality Due to Malignant Neoplasms of Female Genital Organs in Poland in the Period 2000–2021—A Population-Based Study." Cancers 16, no. 5 (March 3, 2024): 1038. http://dx.doi.org/10.3390/cancers16051038.
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The aim of this study is to assess mortality trends due to malignant neoplasms of female genital organs (MNFGOs) in Poland between 2000 and 2021. For the purpose of the study, the authors used data on all deaths of Polish female inhabitants due to MNFGO between 2000 and 2021, obtained from the Statistics Poland database. The standardised death rates (SDR), potential years of life lost (PYLL), annual percentage change (APC) and average annual percentage change (AAPC) were calculated. Between the years 2000 and 2021, 138,000 women died due to MNFGOs in Poland. Of this number, 54,975 (39.8%) deaths were caused by ovarian cancer, 37,487 (27.2%) by cervix uteri cancer, and 26,231 (19.0%) by corpus uteri cancer. A decrease in mortality due to cervix uteri cancer (APC = −2.4%, p < 0.05) was the most favourable change that occurred in the period 2000–2021, while the least favourable change was an increase in mortality due to corpus uteri cancer for the period 2005–2019 (APC = 5.0%, p < 0.05). SDRs due to ovarian cancer showed a decreasing trend between 2007 and 2021 (APC = −0.5%, p < 0.05). The standardised PYLL index due to cervical cancer was 167.7 per 100,000 women in 2000 and decreased to 75.0 in 2021 (AAPC = −3.7, p < 0.05). The number of lost years of life due to ovarian cancer decreased from 143.8 in 2000 to 109.5 in 2021 (AAPC = −1.3, p < 0.05). High values of death rates due to MNFGO in Poland, compared to other European countries, show that there is a need to promote preventive programmes and continue to monitor changes in mortality.
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de Ronde, Hans, and Rogier M. Bertina. "Laboratory Diagnosis of APC-Resistance: A Critical Evaluation of the Test and the Development of Diagnostic Criteria." Thrombosis and Haemostasis 72, no. 06 (1994): 880–86. http://dx.doi.org/10.1055/s-0038-1648978.
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SummaryThe APC-resistance test consists of two APTT’s, one in the presence and one in the absence of a fixed amount of Activated Protein C (APC), and is a simple and reliable method to detect a reduced sensitivity to the anticoagulant action of APC (APC-resistance). At a fixed concentration of APC the prolongation of the APTT is dependent on the activator, the CaCl2 concentration, the citrate concentration in the sample, and on sample handling. The effect of sample handling can be reduced by calculating the APC-Sensitivity Ratio (APC-SR). The actual prolongation of the APTT is also influenced by low protein S levels (reduction of APC-SR) and by reduced levels of factors V, VIII and IX (increase of APC-SR). The APC-SR is most dramaticly effected by reduced levels of factors II and X, which result often in “unmeasurable” APC-SR’s in plasmas of patients on oral anticoagulant treatment. So at present no reliable APC-SR’s can be measured in these patients. Patients treated with heparin can be tested after treatment of their plasma with Hepzym®. The inter- and intra-assay variation in the APC-SR is 4% and 2%, respectively, when using the same batches of activator and APC. The variation which is introduced in the APC-SR by use of different batches of activator or APC, or by the use of different APC or CaCl2 concentrations, can effectively be avoided by expressing the result of the test in normalized-APC-SR (n-APC-SR).The diagnosis of APC-resistance is defined by a n-APC-SR < 0.84. Patients who are heterozygous for the Factor V Leiden mutation have a n-APC-SR of 0.45-0.70, while patients who are homozygous for the mutation have a n-APC-SR <0.45.
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Batyrbekov, K., and A. Galiakbarova. "THE USE OF ARGON PLASMA COAGULATION IN ENDOSCOPY." Oncologia i radiologia Kazakhstana 69, no. 3 (October 10, 2023): 27–33. http://dx.doi.org/10.52532/2663-4864-2023-3-69-27-33.
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Relevance: Argon plasma coagulation (APC) is a minimally invasive, non-contact electrosurgery method. This procedure is performed in the following conditions: bleeding in hollow organs, including ulceration after radiation therapy, Barrett’s esophagus, with the germination of a malignant tumor through a stent, benign neoplasms, precancerous conditions, some malignant tumors at the earliest stages. In this article, the authors present the first and successful experience of the use of APC in Kazakhstan during endoscopic interventions in patients with various pathologies.
The aim of the study was to evaluate the effectiveness of the introduction of APC as an endoscopic treatment in patients with precancerous pathology and complications of surgical treatment in oncological patients.
Methods: A retrospective analysis of the use and effectiveness of AIC was carried out in 15 patients with various pathologies who were on inpatient treatment at the National Research Oncology Center (NROC, Astana, Kazakhstan) during 2022.
Results: Barrett’s esophageal APC was successfully performed in the NROC hospital in 6 patients, no signs of intestinal-type metaplasia of the esophageal epithelium were detected in the biopsy material. Two patients with post-radiation hemorrhagic proctitis underwent coagulation in Pulse 15Wt mode and argon flow of 0.4-1.0 L/min. A patient with the GAVE syndrome with hemorrhages underwent 2 sessions of APC in 35Wt mode with a gas flow of 0.8 L/min. In 3 patients with fistulas of the suture of the main bronchus, coagulation was performed after pulmonectomy and closure of the fistula was observed for 1 week. Two patients with esophagoenteroanastomosis failure underwent 2 sessions of APC using 40-watt argon with an interval of 5 days. After anterior rectal resection, the patient had a failure of anastomosis with a multi-chamber cavity and the presence of purulent contents. 4 courses of APC were conducted with an interval of 2 weeks, after the APC, the mouth of the main chamber narrowed, the discharge of pus stopped, as a result, there was a blind pocket up to 2.0 cm without additional chambers and signs of inflammation.
Conclusion: The presented article describes the results of the introduction of APC as an endoscopic method of treating patients with various pathologies in an oncological clinic, and based on these results, APC can be recommended for widespread implementation throughout Kazakhstan.
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Bhandaru, Madhuri, Daniela S. Kempe, Anand Rotte, Rexhep Rexhepaj, Dietmar Kuhl, and Florian Lang. "Hyperaldosteronism, hypervolemia, and increased blood pressure in mice expressing defective APC." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 297, no. 3 (September 2009): R571—R575. http://dx.doi.org/10.1152/ajpregu.00070.2009.
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Adenomatous polyposis coli (APC) fosters degradation of β-catenin, a multifunctional protein upregulating the serum- and glucocorticoid-inducible kinase (SGK1). SGK1 regulates a wide variety of renal transport processes. The present study explored the possibility that APC influences renal function. To this end, metabolic cage experiments were performed in mice carrying a loss-of-function mutation in the APC gene ( apc Min/+), their wild-type littermates ( apc+/+), and apc Min/+ mice lacking functional SGK1 ( apc Min/+ /sgk1−/−). As a result, mean body weight, food intake, fluid intake, salt appetite, urinary flow, as well as plasma Na+ and K+ concentrations were similar in apc Min/+ mice, apc+/+ mice, and apc Min/+ /sgk1−/− mice. Glomerular filtration rate and absolute renal Na+ excretion were decreased, and fractional urinary K+ excretion was enhanced in apc Min/+ mice. The antinatriuresis, but not the hypofiltration and kaliuresis was partially reversed by additional lack of SGK1. Plasma corticosterone and aldosterone concentrations were significantly enhanced in apc Min/+ mice. While the plasma corticosterone concentration was similar in apc+/+ mice and apc Min/+ /sgk1−/− mice, plasma aldosterone was even higher in apc Min/+ /sgk1−/− mice than in apc Min/+ mice. The hyperaldosteronism of apc Min/+ mice was paralleled by significantly elevated plasma volume and blood pressure. The experiments reveal an influence of defective APC on adrenal hormone release and renal function, effects partially but not completely explained by APC dependence of SGK1 expression.
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Carlberg, Michael, Tarmo Koppel, Lena K. Hedendahl, and Lennart Hardell. "Is the Increasing Incidence of Thyroid Cancer in the Nordic Countries Caused by Use of Mobile Phones?" International Journal of Environmental Research and Public Health 17, no. 23 (December 7, 2020): 9129. http://dx.doi.org/10.3390/ijerph17239129.
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The International Agency for Research on Cancer (IARC) at the World Health Organization (WHO) categorized in 2011 radiofrequency (RF) as a possible human carcinogen, Group 2B. During use of the handheld wireless phone, especially the smartphone, the thyroid gland is a target organ. During the 21st century, the incidence of thyroid cancer is increasing in many countries. We used the Swedish Cancer Register to study trends from 1970 to 2017. During that time period, the incidence increased statistically significantly in women with average annual percentage change (AAPC) +2.13%, 95% confidence interval (CI) +1.43, +2.83%. The increase was especially pronounced during 2010–2017 with annual percentage change (APC) +9.65%, 95% CI +6.68, +12.71%. In men, AAPC increased during 1970–2017 with +1.49%, 95% CI +0.71, +2.28%. Highest increase was found for the time period 2001–2017 with APC +5.26%, 95% CI +4.05, +6.49%. Similar results were found for all Nordic countries based on NORDCAN 1970–2016 with APC +5.83%, 95% CI +4.56, +7.12 in women from 2006 to 2016 and APC + 5.48%, 95% CI +3.92, +7.06% in men from 2005 to 2016. According to the Swedish Cancer Register, the increasing incidence was similar for tumors ≤4 cm as for tumors >4 cm, indicating that the increase cannot be explained by overdiagnosis. These results are in agreement with recent results on increased thyroid cancer risk associated with the use of mobile phones. We postulate that RF radiation is a causative factor for the increasing thyroid cancer incidence.
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Ba shbil, Abdullah, Y. S. Nagaraju, H. Ganesha, S. Veeresh, D. S. Suresh, S. P. Vijaykumar, and Sapna Sharanappa. "Nilgiri tree peels-derived activated porous carbon for high performance supercapacitor applications." IOP Conference Series: Materials Science and Engineering 1300, no. 1 (April 1, 2024): 012010. http://dx.doi.org/10.1088/1757-899x/1300/1/012010.
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Abstract In this study, the activated porous carbon (APC-x) was collected from Nilgiri tree peels, making it a sustainable and cost-effective green synthesis approach. The raw material undergoes carbonization and activating it using KOH as chemical activation agent. The chemical composition, crystallinity and morphology of the surface of ACP-x was examined by Fourier Transform infra-red (FTIR), X-ray diffraction and Field emission scanning electron microscope (FESEM). The cyclic voltammetry technique was used to measure the electrochemical performance of APC-x using PVA/KOH gel electrolyte in two-electrode system. The highest specific capacitance value 140 F/g was obtained for APC-0 at scan rate of 10 mV/s. The use of Nilgiri tree peels as precursor for activated porous carbon production presents a sustainable approach for developing high-performance supercapacitor materials.
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Tanaka, Makito, Tetsuro Sasada, Tetsuya Nakamoto, Sascha Ansén, Osamu Imataki, Alla Berezovskaya, Marcus Butler, Lee Nadler, and Naoto Hirano. "Immunogenicity of Artificial Dendritic Cells Is Upregulated by ROCK Inhibition-Mediated Dendrite Formation." Blood 114, no. 22 (November 20, 2009): 3022. http://dx.doi.org/10.1182/blood.v114.22.3022.3022.
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Abstract Abstract 3022 Poster Board II-998 Dendritic cells (DC) are “professional” antigen-presenting cells (APC) that can prime T cells. Their characteristic morphology and phenotype segregate them from other APC. Many studies suggest that mature DC are able to induce potent antitumor T cell immunity that can reject tumors. Based on this, numerous cancer vaccine trials using ex vivo generated DC have been conducted in humans. However, the observed objective response rates in these studies have been disappointing. This could partially be attributed to difficulties in generating large numbers of clinical grade, optimally matured DC. Also, it is widely accepted that the quality and quantity of DC generated ex vivo vary substantially among individuals. We have hypothesized that the generation of standardized artificial DC (aDC) will overcome the time, expense, and suboptimal reproducibility of DC cultures and prompt the development of DC-based immunotherapy for cancer. Previously, we developed a renewable and standardized artificial APC (aAPC) by transducing HLA-A2, CD80, and CD83 to the human erythroleukemic suspension cell line, K562. This aAPC can naturally process and present HLA-A2-restricted peptides and uniquely support the priming and prolonged expansion of large numbers of antigen-specific CD8+ CTL. Generated antigen-specific CTL display a central ∼ effector memory phenotype consistent with in vivo persistence, possess potent effector function, and specifically recognize tumor cells. Furthermore, CTL can be maintained in vitro for a prolonged period of time up to >1 year without any feeder cells or cloning. Recent clinical trials have demonstrated that adoptive transfer of anti-tumor CTL with a memory phenotype generated ex vivo using this aAPC, IL-2, and IL-15 can persist in cancer patients as memory T cells for >6 months without any lymphodepletion, adjuvants, or cytokine administration. Clinical responses have also been observed in some patients. To develop a standardized aDC, we have undertaken an approach to differentiate our K562-based aAPC into aDC. In neurogenesis, it has been well established that a family of Rho GTPases (Rho, Rac, and Cdc42) critically regulates the outgrowth of neurites, i.e. dendrites and axon. We have found that the inhibition of Rho kinase (ROCK), which is a key effector molecule of Rho, can promote the differentiation of monocyte-derived immature DC into mature DC both morphologically and phenotypically. Intriguingly, when aAPC were forced to attach via a newly identified surface molecule, PladX, and ROCK activity was subsequently blocked, K562-derived aAPC “differentiated” into DC-like cells by acquiring dendrite extensions and growth cone-like structures at the end of the extensions (see picture). PladX-mediated strong attachment was critical for differentiation, since ROCK inhibition without attachment or following attachment via conventional adhesion molecules such as poly-L lysine, fibronectin, or collagen was not sufficient to induce dendrites. Confocal microscopy analysis revealed that dendrites were composed of F-actin rich filopodia and lamellipodia. Furthermore, F-actin and microtubules were differentially localized in the “growth cones” and “dendrite shafts” of aDC, respectively. While treatment with actin inhibitors blocked the generation of “growth cones” but not dendritic shafts, exposure to microtubule inhibitors abrogated the extension of dendritic shafts. Finally, we were able to demonstrate that aDC were more potent than aAPC in CD8+ T cell stimulatory activity. This was the case despite the fact that differentiation of aAPC into aDC does not alter the expression level of molecularly engineered immunoaccessory molecules MHC class I, CD80, and CD83. The effects of the differentiation on processing and presentation of antigenic peptides were negligible since CD8+ T cell antigen was exogenously pulsed as a fully processed synthetic peptide. Taken together, this result indicates that the dendrite formation and the resultant enlarged surface area are critical determinants of DC's enhanced immunogenicity. We have succeeded in producing infinite number of aDC with enhanced immunogenicity by differentiating our renewable and standardized K562-based aAPC, which has been already tested in the clinic. This novel aDC may overcome the cumbersome issues inherent to conventional DC and widen the applicability of DC-based immunotherapy for cancer. Disclosures No relevant conflicts of interest to declare.
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Yang, Xia V., John H. Griffin, and Laurent O. Mosnier. "Anti-Inflammatory and Anti-Apoptotic Activities of Activated Protein C Are Independent of Anticoagulant Activity." Blood 108, no. 11 (November 16, 2006): 65. http://dx.doi.org/10.1182/blood.v108.11.65.65.
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Abstract Activated protein C (APC), a well known anticoagulant enzyme, reduces mortality in severe sepsis patients and exhibits beneficial effects in multiple animal injury models, including neuroprotective activity in rodent ischemic stroke, attenuation of inflammatory lung injury, and survival benefits in rodent sepsis models. For these in vivo benefits, the relative importance of APC’s anticoagulant activity vs. APC’s direct cytoprotective effects on cells is unclear. APC anticoagulant activity involves inactivation of factors Va and VIIIa whereas cytoprotection by APC involves two receptors, Endothelial Protein C Receptor (EPCR) and Protease Activated Receptor-1. To distinguish the cytoprotective from the anticoagulant activities of APC, we made recombinant human wild type (wt) APC and a protease domain mutant, 5A-APC (RR229/230AA + KKK191−193AAA), a Gla domain mutant, PTGla-APC (APC with prothrombin residues 1–46)(Smirnov et al JBC 1998) and an active site mutant, S360A-APC. Active site titration and chromogenic assays showed that wtAPC, 5A-APC and PTGla-APC had full enzymatic activity while S360A-APC had none. 5A-APC had almost no anticoagulant activity (< 3 %) whereas PTGla-APC had 300% of wtAPC anticoagulant activity. APC binding to EPCR was assayed as binding to immobilized soluble EPCR and to K293 cells transfected with wtEPCR. We verified that wtAPC and 5A-APC each could bind to EPCR with similar affinity (Kd,app = 37 nM and 29 nM, respectively) whereas, in contrast, PTGla-APC bound very weakly to EPCR (Kd,app > 300 nM ). We then compared the anti-inflammatory and anti-apoptotic activities of the hypo-anticoagulant 5A-APC and the hyper-anticoagulant PTGla-APC to those of wtAPC. To assay APC anti-inflammatory activity, APC-mediated inhibition of LPS-induced TNFα secretion from U937 monocytic cells was determined. The ability of 5A-APC to inhibit LPS-induced TNFα secretion was indistinguishable from that of wtAPC with half-maximum inhibition at 5.4 nM and 6.5 nM, respectively. Neither the enzymatically inactive S360A-APC not the protein C zymogen inhibited LPS-induced TNFα secretion, indicating that a functional APC active site was required. Anti-EPCR antibodies blocking APC binding prevented the anti-inflammatory activity of wtAPC, indicating binding of APC to EPCR on U937 cells was required. The anti-apoptotic activity of each APC species was determined in staurosporine-induced endothelial cell apoptosis assays. Dose-dependent inhibition of apoptosis by 5A-APC was indistinguishable from that by wt-APC with half-maximum inhibition at 0.70 and 2.0 nM, respectively. In contrast to this potent anti-apoptotic activity of wtAPC and 5A-APC, the hyper-anticoagulant PTGla-APC required a 24-fold higher concentration for half-maximal inhibition of endothelial apoptosis. As expected, S360A-APC showed no significant inhibition of endothelial apoptosis. Hence, the 5A-APC variant with < 3% anticoagulant activity exhibited normal anti-inflammatory and anti-apoptotic activities in vitro on monocytic and endothelial cells. These APC variants may be useful for in vivo assessment of the relative importance of APC’s anticoagulant vs. cytoprotective activities. In summary, these data highlight important distinctions between structural requirements for APC’s anticoagulant functions compared to its anti-inflammatory and anti-apoptotic activities. These structural insights may lead to safer therapeutic APC variants that retain APC’s beneficial cytoprotective effects but that have reduced bleeding risk due to reduction in anticoagulant activity.
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Preston, Roger JS, Shona Harmon, Fionnuala B. Ni Ainle, Jennifer A. Johnson, Moya Cunningham, O. Smith, Barry White, and James S. O’Donnell. "Dissociation of Activated Protein C Functions by Elimination of Protein S Cofactor Enhancement." Blood 112, no. 11 (November 16, 2008): 21. http://dx.doi.org/10.1182/blood.v112.11.21.21.
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Abstract Activated protein C (APC) plays a critical anticoagulant role by inactivating factor Va (FVa) and factor VIIIa (FVIIIa) and thus down-regulating thrombin generation. In addition, APC bound to the endothelial cell protein C receptor (EPCR) can initiate PAR-1 mediated cytoprotective signalling. Although protein S constitutes a critical cofactor for APC anticoagulant function, the molecular basis through which protein S interacts with APC is not fully understood. In this study, we employed a site-directed mutagenesis strategy to characterise the effects of four single amino acid substitutions (D35T, D36A, L38D and A39V) within a region of the APC Gla domain important for protein S cofactor enhancement. To maintain Gla domain structural integrity, each residue was substituted with the corresponding residue of the human prothrombin Gla domain. Protein C variants were expressed in HEK 293 cells and purified by ion-exchange chromatography. Upon activation, the amidolytic activity of each recombinant APC variant was identical to that of wild type APC. The anticoagulant function of recombinant wild type and variant APC was compared in a tissue factor-initiated thrombin generation assay using protein C-deficient plasma. Wild type APC diminished thrombin generation in a concentration-dependent manner as expected. Variants APC-D35T, APC-D36A and APC-A39V exhibited only mildly impaired (<2-fold) anticoagulant activity compared to wild type APC. The anticoagulant activity of APC-L38D, however, was severely impaired. APC-L38D was unable to achieve half-maximal inhibition of endogenous thrombin potential (ETP) at APC concentrations as high as 150nM, compared to wild type APC, which achieved half-maximal inhibition at 7.2nM APC. To clarify the role of Leu-38 in facilitating APC anticoagulant function, we further studied the ability of APC-L38D to be stimulated in protein S-deficient plasma reconstituted with plasma-purified protein S. Co-incubation of wild type APC with increasing protein S concentration (12.5–200nM) caused a corresponding reduction in ETP (IC50 = 24nM protein S). In contrast, APC-L38D was unresponsive to protein S. In the presence of APC-L38D, ETP was reduced only 22% at 1.5μM protein S (10-fold higher than plasma free protein S). In a phospholipid-dependent FVa proteolysis time course assay, both wild type APC and APC-L38D rapidly reduced FVa cofactor activity, indicating that the observed impaired plasma anticoagulant activity of APC-L38D is not mediated by impaired interaction with anionic phospholipids or FVa. In a modified version of this assay, wild type APC-mediated FVa proteolysis was rapidly enhanced by added protein S, with half-maximal inhibition observed at 5nM protein S. In contrast, APC-L38D exhibited no protein S-enhanced FVa proteolysis. Cumulatively, these data confirm that Leu-38 mediates APC anticoagulant function in plasma by facilitating critical protein S cofactor enhancement of FVa proteolysis. Previous studies have shown that APC Gla domain mutations can influence EPCR binding, a pre-requisite for PAR-1 mediated cytoprotective signalling. Consequently, we assessed APC binding to sEPCR using surface plasmon resonance. Binding affinities of APC-L38D and wild type APC were very similar (KD 112±25nM versus 117±36nM). Furthermore, the ability of APC-L38D to protect EAhy926 cells from staurosporine-induced apoptosis was also investigated using RT-PCR quantification of pro- (bax) and anti- (bcl-2) apoptotic gene expression. Pre-incubation with APC-L38D significantly reduced the bax/bcl-2 ratio to the same extent as wild type APC. The EPCR-dependence of these anti-apoptotic activities was confirmed using RCR-252, (an inhibitory anti-EPCR antibody) which ablated the cytoprotective effect of both APC species. In conclusion, we demonstrate that a single amino acid substitution (L38D) can significantly impair APC anticoagulant activity due to elimination of protein S cofactor enhancement. However, despite the location of Leu-38 in the Gla domain, APC-L38D retains its ability to bind EPCR, and trigger PAR-1 mediated cytoprotective signalling in a manner indistinguishable from that of wild type APC. Consequently, elimination of protein S cofactor enhancement of APC anticoagulant function represents a novel and effective strategy by which to dissociate the anticoagulant and cytoprotective functions of APC for potential therapeutic gain.
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Livnat, Tami, Yehonatan Weinberger, José A. Fernández, Alaa Bashir, Gil Ben-David, Dahlia Palevski, Sarina Levy-Mendelovich, et al. "Activated Protein C (APC) and 3K3A-APC-Induced Regression of Choroidal Neovascularization (CNV) Is Accompanied by Vascular Endothelial Growth Factor (VEGF) Reduction." Biomolecules 11, no. 3 (February 26, 2021): 358. http://dx.doi.org/10.3390/biom11030358.
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The activated protein C (APC) ability to inhibit choroidal neovascularization (CNV) growth and leakage was recently shown in a murine model. A modified APC, 3K3A-APC, was designed to reduce anticoagulant activity while maintaining full cytoprotective properties, thus diminishing bleeding risk. We aimed to study the ability of 3K3A-APC to induce regression of CNV and evaluate vascular endothelial growth factor (VEGF) role in APC’s activities in the retina. CNV was induced by laser photocoagulation on C57BL/6J mice. APC and 3K3A-APC were injected intravitreally after verification of CNV presence. CNV volume and vascular penetration were evaluated on retinal pigmented epithelium (RPE)-choroid flatmount by fluorescein isothiocyanate (FITC)-dextran imaging. VEGF levels were measured using immunofluorescence anti-VEGF staining. We found that 3K3A-APC induced regression of pre-existing CNV. VEGF levels, measured in the CNV lesion sites, significantly decreased upon APC and 3K3A-APC treatment. Reduction in VEGF was sustained 14 days post a single APC injection. As 3K3A-APC retained APCs’ activities, we conclude that the anticoagulant properties of APC are not mandatory for APC activities in the retina and that VEGF reduction may contribute to the protective effects of APC and 3K3A-APC. Our results highlight the potential use of 3K3A-APC as a novel treatment for CNV and other ocular pathologies.
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Castoldi, Elisabetta, Jeroen M. Brugge, Gerry A. F. Nicolaes, Domenico Girelli, Guido Tans, and Jan Rosing. "Impaired APC cofactor activity of factor V plays a major role in the APC resistance associated with the factor V Leiden (R506Q) and R2 (H1299R) mutations." Blood 103, no. 11 (June 1, 2004): 4173–79. http://dx.doi.org/10.1182/blood-2003-10-3578.
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Abstract Activated protein C (APC) resistance is a major risk factor for venous thrombosis. Factor V (FV) gene mutations like FVLeiden (R506Q) and FVR2 (H1299R) may cause APC resistance either by reducing the susceptibility of FVa to APC-mediated inactivation or by interfering with the cofactor activity of FV in APC-catalyzed FVIIIa inactivation. We quantified the APC cofactor activity expressed by FVLeiden and FVR2 and determined the relative contributions of reduced susceptibility and impaired APC cofactor activity to the APC resistance associated with these mutations. Plasmas containing varying concentrations of normal FV, FVLeiden, or FVR2 were assayed with an APC resistance assay that specifically measures the APC cofactor activity of FV in FVIIIa inactivation, and with the activated partial thromboplastin time (aPTT)-based assay, which probes both the susceptibility and APC cofactor components. FVR2 expressed 73% of the APC cofactor activity of normal FV, whereas FVLeiden exhibited no cofactor activity in FVIIIa inactivation. Poor susceptibility to APC and impaired APC cofactor activity contributed equally to FVLeiden-associated APC resistance, whereas FVR2-associated APC resistance was entirely due to the reduced APC cofactor activity of FVR2. Thrombin generation assays confirmed the importance of the anticoagulant activity of FV and indicated that FVLeiden homozygotes are exposed to a higher thrombotic risk than heterozygotes because their plasma lacks normal FV acting as an anticoagulant protein.
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Kita, Katsuhiro, Torsten Wittmann, Inke S. Näthke, and Clare M. Waterman-Storer. "Adenomatous Polyposis Coli on Microtubule Plus Ends in Cell Extensions Can Promote Microtubule Net Growth with or without EB1." Molecular Biology of the Cell 17, no. 5 (May 2006): 2331–45. http://dx.doi.org/10.1091/mbc.e05-06-0498.
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In interphase cells, the adenomatous polyposis coli (APC) protein accumulates on a small subset of microtubules (MTs) in cell protrusions, suggesting that APC may regulate the dynamics of these MTs. We comicroinjected a nonperturbing fluorescently labeled monoclonal antibody and labeled tubulin to simultaneously visualize dynamics of endogenous APC and MTs in living cells. MTs decorated with APC spent more time growing and had a decreased catastrophe frequency compared with non-APC-decorated MTs. Endogenous APC associated briefly with shortening MTs. To determine the relationship between APC and its binding partner EB1, we monitored EB1-green fluorescent protein and endogenous APC concomitantly in living cells. Only a small fraction of EB1 colocalized with APC at any one time. APC-deficient cells and EB1 small interfering RNA showed that EB1 and APC localized at MT ends independently. Depletion of EB1 did not change the growth-stabilizing effects of APC on MT plus ends. In addition, APC remained bound to MTs stabilized with low nocodazole, whereas EB1 did not. Thus, we demonstrate that the association of endogenous APC with MT ends correlates directly with their increased growth stability, that this can occur independently of its association with EB1, and that APC and EB1 can associate with MT plus ends by distinct mechanisms.
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Listovsky, Tamar, and Julian E. Sale. "Sequestration of CDH1 by MAD2L2 prevents premature APC/C activation prior to anaphase onset." Journal of Cell Biology 203, no. 1 (October 7, 2013): 87–100. http://dx.doi.org/10.1083/jcb.201302060.
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The switch from activation of the anaphase-promoting complex/cyclosome (APC/C) by CDC20 to CDH1 during anaphase is crucial for accurate mitosis. APC/CCDC20 ubiquitinates a limited set of substrates for subsequent degradation, including Cyclin B1 and Securin, whereas APC/CCDH1 has a broader specificity. This switch depends on dephosphorylation of CDH1 and the APC/C, and on the degradation of CDC20. Here we show, in human cells, that the APC/C inhibitor MAD2L2 also contributes to ensuring the sequential activation of the APC/C by CDC20 and CDH1. In prometaphase, MAD2L2 sequestered free CDH1 away from the APC/C. At the onset of anaphase, MAD2L2 was rapidly degraded by APC/CCDC20, releasing CDH1 to activate the dephosphorylated APC/C. Loss of MAD2L2 led to premature association of CDH1 with the APC/C, early destruction of APC/CCDH1 substrates, and accelerated mitosis with frequent mitotic aberrations. Thus, MAD2L2 helps to ensure a robustly bistable switch between APC/CCDC20 and APC/CCDH1 during the metaphase-to-anaphase transition, thereby contributing to mitotic fidelity.
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Solymoss, Susan, and Kim Thi Phu Nguyen. "Plasma Factor V Activation Is Prevented by Activated Protein C in the Presence of Phospholipid Vesicles, Not Platelets." Thrombosis and Haemostasis 69, no. 02 (1993): 124–29. http://dx.doi.org/10.1055/s-0038-1651567.
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SummaryActivated protein C (APC) is a vitamin K dependent anticoagulant which catalyzes the inactivation of factor Va and VIIIa, in a reaction modulated by phospholipid membrane surface, or blood platelets. APC prevents thrombin generation at a much lower concentration when added to recalcified plasma and phospholipid vesicles, than recalcified plasma and platelets. This observation was attributed to a platelet associated APC inhibitor. We have performed serial thrombin, factor V one stage and two stage assays and Western blotting of dilute recalcified plasma containing either phospholipid vesicles or platelets and APC. More thrombin was formed at a given APC concentration with platelets than phospholipid. One stage factor V values increased to higher levels with platelets and APC than phospholipid and APC. Two stage factor V values decreased substantially with platelets and 5 nM APC but remained unchanged with phospholipid and 5 nM APC. Western blotting of plasma factor V confirmed factor V activation in the presence of platelets and APC, but lack of factor V activation with phospholipid and APC. Inclusion of platelets or platelet membrane with phospholipid enhanced rather than inhibited APC catalyzed plasma factor V inactivation. Platelet activation further enhanced factor V activation and inactivation at any given APC concentration.Plasma thrombin generation in the presence of platelets and APC is related to ongoing factor V activation. No inhibition of APC inactivation of FVa occurs in the presence of platelets.
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Wang, Chongkai, Ching Ouyang, Jaideep Singh Sandhu, Michael Kahn, and Marwan Fakih. "Wild-type APC and prognosis in metastatic colorectal cancer." Journal of Clinical Oncology 38, no. 4_suppl (February 1, 2020): 223. http://dx.doi.org/10.1200/jco.2020.38.4_suppl.223.
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223 Background: Somatic mutations at adenomatous polyposis coli ( APC) gene, found in ~75% of colorectal cancers (CRC), are under-represented in microsatellite instable (MSI-H) tumors. While several studies have suggested worse outcomes for CRC patients (pts) with wild-type APC ( APC-WT), the prognostic implication of this genomic alteration in metastatic CRC (mCRC) is not well defined. Methods: APC prognostic value was evaluated in 331 stage IV microsatellite stable (MSS) CRC pts treated in our institution. Next-generation genomic analysis (FoundationOne) was used to characterize the molecular characteristics of APC-WT and mutant APC ( APC-MT) pts. Findings were validated on a public database of stage IV colon cancer from MSKCC. Results: APC-WT was present in 26% of mCRC patients. In comparison to APC-MT population (n = 244), APC-WT pts (n = 87) tended to be younger (median age: 49 vs. 58 years), right-sided (44% vs. 24%), BRAF-V600E mutated (25% vs. 5%), p53 WT (38% vs. 21%) and RAS WT (66% vs. 53%). APC-WT tumors were associated with other Wnt activating alterations ( CTNNB1, FBXW7, RNF43, ARID1A and SOX9). Among those, RNF43 and CTNNB1 were more significantly represented in the APC-WT vs APC-MT population (12% vs 1% and 11% vs 3%, respectively). APC-WT pts had a worse overall survival (OS) than APC-MT pts (30 vs 48 months, HR = 1.809, 95% CI 1.260-2.596, p < 0.0001). Using a multivariate model correcting for primary tumor location, RAS and BRAF status, APC-WT was predictive of poor survival (HR = 1.7, p = 0.001) in our data set. The prognostic implication of APC-WT on OS were confirmed further in a similar multivariate model of 433 stage IV pts from MSKCC public database (HR = 1.6, P = 0.01). Conclusions: APC-WT is associated with poor OS in MSS mCRC regardless of RAS, BRAF status. Compared with APC-MT mCRC tumors, APC-WT tumors were associated with other activating alterations of Wnt pathway, including RNF43 and CTNBB1.
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Barth, Angela I. M., Kathleen A. Siemers, and W. James Nelson. "Dissecting interactions between EB1, microtubules and APC in cortical clusters at the plasma membrane." Journal of Cell Science 115, no. 8 (April 15, 2002): 1583–90. http://dx.doi.org/10.1242/jcs.115.8.1583.
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End-binding protein (EB) 1 binds to the C-terminus of adenomatous polyposis coli (APC) protein and to the plus ends of microtubules (MT) and has been implicated in the regulation of APC accumulation in cortical clusters at the tip of extending membranes. We investigated which APC domains are involved in cluster localization and whether binding to EB1 or MTs is essential for APC cluster localization. Armadillo repeats of APC that lack EB1- and MT-binding domains are necessary and sufficient for APC localization in cortical clusters; an APC fragment lacking the armadillo repeats, but containing MT-and EB1-binding domains, does not localize to the cortical clusters but instead co-aligns with MTs throughout the cell. Significantly, analysis of endogenous proteins reveals that EB1 does not accumulate in the APC clusters. However, overexpressed EB1 does accumulate in APC clusters; the APC-binding domain in EB1 is located in the C-terminal region of EB1 between amino acids 134 and 268. Overexpressed APC- or MT-binding domains of EB1 localize to APC cortical clusters and MT, respectively, without affecting APC cluster formation itself. These results show that localization of APC in cortical clusters is different from that of EB1 at MT plus ends and appears to be independent of EB1.
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Murakami, K., K. Okajima, M. Uchiba, M. Johno, T. Nakagaki, H. Okabe, and K. Takatsuki. "Activated protein C prevents LPS-induced pulmonary vascular injury by inhibiting cytokine production." American Journal of Physiology-Lung Cellular and Molecular Physiology 272, no. 2 (February 1, 1997): L197—L202. http://dx.doi.org/10.1152/ajplung.1997.272.2.l197.
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We investigated the effect of activated protein C (APC) on pulmonary vascular injury and the increase in tumor necrosis factor (TNF) levels in lipopolysaccharide (LPS)-treated rats to determine whether APC reduces LPS-induced endothelial damage by inhibiting cytokine production. Intravenously administered LPS (5 mg/kg) induced pulmonary vascular injury, as indicated by an increase in the lung wet-to-dry weight ratio. LPS-induced pulmonary vascular injury was prevented by APC but not by active site-blocked factor Xa [dansyl glutamyl-glycyl-arginyl chloromethyl detone-treated activated factor X (DEGR-Xa)], a selective inhibitor of thrombin generation, or inactivated APC [diisopropyl fluorophosphate-treated APC (DIP-APC)]. APC, but not DEGR-Xa or DIP-APC, significantly inhibited the LPS-induced increase in the plasma level of TNF. APC significantly inhibited the production of TNF by LPS-stimulated monocytes in a dose-dependent fashion in vitro, but DIP-APC did not. APC did not inhibit the functions of activated neutrophils in vitro. These findings suggest that APC prevented LPS-induced pulmonary vascular injury by inhibiting TNF production by monocytes and not via its anticoagulant activity. The serine protease activity of APC appears to be essential for inhibition of TNF production.
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Thorelli, Elisabeth, Randal J. Kaufman, and Björn Dahlbäck. "Cleavage of Factor V at Arg 506 by Activated Protein C and the Expression of Anticoagulant Activity of Factor V." Blood 93, no. 8 (April 15, 1999): 2552–58. http://dx.doi.org/10.1182/blood.v93.8.2552.
Full textAbstract:
Abstract Activated protein C (APC) inhibits coagulation by cleaving and inactivating procoagulant factor Va (FVa) and factor VIIIa (FVIIIa). FV, in addition to being the precursor of FVa, has anticoagulant properties; functioning in synergy with protein S as a cofactor of APC in the inhibition of the FVIIIa-factor IXa (FIXa) complex. FV:Q506 isolated from an individual homozygous for APC-resistance is less efficient as an APC-cofactor than normal FV (FV:R506). To investigate the importance of the three APC cleavage sites in FV (Arg-306, Arg-506, and Arg-679) for expression of its APC-cofactor activity, four recombinant FV mutants (FV:Q306, FV:Q306/Q506, FV:Q506, and FV:Q679) were tested. FV mutants with Gln (Q) at position 506 instead of Arg (R) were found to be poor APC-cofactors, whereas Arg to Gln mutations at positions 306 or 679 had no negative effect on the APC-cofactor activity of FV. The loss of APC-cofactor activity as a result of the Arg-506 to Gln mutation suggested that APC-cleavage at Arg-506 in FV is important for the ability of FV to function as an APC-cofactor. Using Western blotting, it was shown that both wild-type FV and mutant FV was cleaved by APC during the FVIIIa inhibition. At optimum concentrations of wild-type FV (11 nmol/L) and protein S (100 nmol/L), FVIIIa was found to be highly sensitive to APC with maximum inhibition occurring at less than 1 nmol/L APC. FV:Q506 was inactive as an APC-cofactor at APC-concentrations ≤ 1 nmol/L and only partially active at higher APC concentrations. Our results show that increased expression of FV anticoagulant activity correlates with APC-mediated cleavage at Arg-506 in FV, but not with cleavage at Arg-306 nor at Arg-679.
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Thorelli, Elisabeth, Randal J. Kaufman, and Björn Dahlbäck. "Cleavage of Factor V at Arg 506 by Activated Protein C and the Expression of Anticoagulant Activity of Factor V." Blood 93, no. 8 (April 15, 1999): 2552–58. http://dx.doi.org/10.1182/blood.v93.8.2552.408k15_2552_2558.
Full textAbstract:
Activated protein C (APC) inhibits coagulation by cleaving and inactivating procoagulant factor Va (FVa) and factor VIIIa (FVIIIa). FV, in addition to being the precursor of FVa, has anticoagulant properties; functioning in synergy with protein S as a cofactor of APC in the inhibition of the FVIIIa-factor IXa (FIXa) complex. FV:Q506 isolated from an individual homozygous for APC-resistance is less efficient as an APC-cofactor than normal FV (FV:R506). To investigate the importance of the three APC cleavage sites in FV (Arg-306, Arg-506, and Arg-679) for expression of its APC-cofactor activity, four recombinant FV mutants (FV:Q306, FV:Q306/Q506, FV:Q506, and FV:Q679) were tested. FV mutants with Gln (Q) at position 506 instead of Arg (R) were found to be poor APC-cofactors, whereas Arg to Gln mutations at positions 306 or 679 had no negative effect on the APC-cofactor activity of FV. The loss of APC-cofactor activity as a result of the Arg-506 to Gln mutation suggested that APC-cleavage at Arg-506 in FV is important for the ability of FV to function as an APC-cofactor. Using Western blotting, it was shown that both wild-type FV and mutant FV was cleaved by APC during the FVIIIa inhibition. At optimum concentrations of wild-type FV (11 nmol/L) and protein S (100 nmol/L), FVIIIa was found to be highly sensitive to APC with maximum inhibition occurring at less than 1 nmol/L APC. FV:Q506 was inactive as an APC-cofactor at APC-concentrations ≤ 1 nmol/L and only partially active at higher APC concentrations. Our results show that increased expression of FV anticoagulant activity correlates with APC-mediated cleavage at Arg-506 in FV, but not with cleavage at Arg-306 nor at Arg-679.
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Pahlevi, Dani Afrizal Putra. "Analisis Produktivitas Usaha Dagang Menggunakan Metode APC dan Craig-Harris di Kecamatan Kepanjenkidul." Jurnal Ilmu Ekonomi JIE 7, no. 01 (March 2, 2023): 53–64. http://dx.doi.org/10.22219/jie.v7i01.23921.
Full textAbstract:
On the 2019-2021 productivity index for the APC method and the Craig Harris method, the material input composition is 51% in the APC method, -55% in the Craig Harris method, and the labor input in the APC method is a 61% reduction, Craig Harris method reduced -38%, APC method reduced total usage by 6% and Craig Harris method reduced -14%. While the energy input component of the APC method increased by 55%, the Craig Harris method increased by 29%, while the capital input component of the APC method increased by 53% and the Craig Harris method increased by 2%. Pada indeks produktivitas metode APC dan metode Craig-Harris pada tahun 2019 sampai tahun 2021 dimana komponen input material pada metode APC 51% dan metode Craig-Harris -55%, input tenaga kerja metode APC 61% dan Metode Craig-Harris -38% serta input total metode APC 6% dan metode Craig-Harris -14% terjadi penurunan. sedangkan pada komponen input energi metode APC 55% dan metode Craig-Harris 29% dan input modal metode APC 53% dan metode Craig-Harris 2% mengalami peningkatan.
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Nicolaes, Gerry A. F., M. Christella, L. G. D. Thomassen, Rene van Oerle, Karly Hamulyak, H. Coenraad Hemker, Guido Tans, and Jan Rosing. "A Prothrombinase-based Assay for Detection of Resistance to Activated Protein C." Thrombosis and Haemostasis 76, no. 03 (1996): 404–10. http://dx.doi.org/10.1055/s-0038-1650591.
Full textAbstract:
SummaryIn this paper we present a new method for the detection of resistance to activated protein C (APC) that is based on direct measurement of the effect of APC on the cofactor activity of plasma factor Va. The factor V present in a diluted plasma sample was activated with thrombin and its sensitivity towards APC was subsequently determined by incubation with phospholipids and APC. The loss of factor Va cofactor activity was quantified in a prothrombinase system containing purified prothrombin, factor Xa and phospholipid vesicles and using a chromogen-ic assay for quantitation of thrombin formation. The reaction conditions were optimized in order to distinguish normal, heterozygous and homozygous APC-resistant plasmas. Maximal differences in the response of these plasmas towards APC were observed when factor Va was inactivated by APC in the absence of protein S and when the cofactor activity of factor Va was determined at a low factor Xa concentration (0.3 nM).Addition of 0.2 nM APC and 20 μM phospholipid vesicles to a 1000-fold diluted sample of thrombin-activated normal plasma resulted in loss of more than 85% of the cofactor activity factor Va within 6 rnin. Under the same conditions, APC inactivated ∼ 60% and ∼20% of the factor Va present in plasma samples from APC-resistant individuals that were heterozygous or homozygous for the mutation Arg506⟶Gln in factor V, respectively. Discrimination between the plasma samples from normal and heterozygous and homozygous APC-resistant individuals was facilitated by introduction of the so-called APC-sensitivity ratio (APC-sr). The APC-sr was defined as the ratio of the factor Va cofactor activities determined in thrombin-activated plasma samples after 6 min incubation with or without 0.2 nM APC and was multiplied by 100 to obtain integers (APC-sr = {factor Va+APC/factor Va−APC} × 100). Clear differences were observed between the APC-sr of plasmas from normal healthy volunteers (APC-sr: 8-20, n = 33) and from individuals that were heterozygous (APC-sr: 35-50, n = 17) or homozygous APC resistant (APC-sr: 82-88, n = 7). There was no mutual overlap between the APC-sr of normal plasmas and plasmas from heterozygous or homozygous APC resistant individuals (p <0.0001). In all cases our test gave the same result as the DNA-based assay. Since the test is performed on a highly diluted plasma sample there is no interference by conditions that affect APC resistance tests that are based on clotting time determinations (e.g. coagulation factor deficiencies, oral anticoagulation, heparin treatment, the presence of lupus anticoagulants, pregnancy or the use of oral contraceptives). Furthermore, we show that part of the factor Va assay can be performed on an autoanalyzer which increases the number of plasma samples that can be handled simultaneously.
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Johnson, Jennifer, Fionnuala Ni Ainle, Shona Harmon, James S. O’Donnell, and Roger JS Preston. "A Single Amino Acid Substitution (I18V) in the Gla Domain of Activated Protein C Markedly Impairs Ability of PE and GlyCer to Enhance Anticoagulant Activity." Blood 112, no. 11 (November 16, 2008): 3071. http://dx.doi.org/10.1182/blood.v112.11.3071.3071.
Full textAbstract:
Abstract Phosphatidylethanolamine (PE) and glucosylceramide (GlyCer) are cell surface lipids that preferentially enhance anticoagulant, rather than procoagulant pathways. In particular, both PE and GlyCer enhance the anticoagulant activity of activated protein C (APC). Previous studies have indicated that specific APC Gla domain residues may mediate APC interaction with PE and GlyCer. To investigate whether specific APC residues mediate PE and GlyCer enhanced APC anticoagulant activity, we expressed a series of APC variants in which APC Gla domain residues not shared with the human prothrombin Gla domain were substituted with their prothrombin amino acid equivalent. The anticoagulant activity of each APC Gla domain variant was assessed in a tissue factor-initiated thrombin generation assay containing phospholipid vesicles of differing composition (80% PC/20% PS); or PC/PS/PE (60%/20%/20%); or PC/PS/GlyCer (60%/20%/20%). For each of these lipid mixtures, thrombin generation (endogenous thrombin potential, ETP) was not significantly different in the absence of APC. In the presence of PC/PS vesicles, APC reduced thrombin generation by 63±3% at the highest APC concentration tested (6nM). However, APC impairment of thrombin generation was enhanced 3-fold in the presence of PC/PS/PE compared with vesicles containing PC/PS alone, and in the presence of PC/PS/GlyCer was enhanced 4.3-fold. Enhancement of anticoagulant function by PE and GlyCer was similar for the majority of the APC Gla domain variants tested. Interestingly, one APC variant (APC-I18V) exhibited similar anticoagulant activity to that of wild type APC with PC/PS vesicles, but was not enhanced by the presence of PE- or GlyCer-containing vesicles. Phospholipid vesicles containing PE or GlyCer have been previously described to enhance protein S cofactor enhancement of APC. Therefore, to further characterize APC-I18V, we assessed the ability of wild type APC and APC-I18V to be enhanced by protein S in the presence of PC/PS, PC/PS/PE or PC/PS/GlyCer using a protein S-sensitive thrombin generation assay. In the presence of PC/PS, increasing protein S concentration in protein S-deficient plasma resulted in an APC-mediated slow decrease in thrombin generation, irrespective of whether wild type or APC-I18V was used (IC50 for protein S-mediated APC inhibition of thrombin generation with PC/PS, 130nM). However, in the presence of PC/PS/PE or PC/PS/GlyCer, thrombin generation was impaired by wild type APC at 3–4-fold lower protein S concentration than that observed when PC/PS vesicles alone were used (IC50, PC/PS/PE=31.5nM and PC/PS/GlyCer=37.5nM). APC-I18V, however, did not exhibit a similarly increased sensitivity to protein S in the presence of PE or GlyCer, as the anticoagulant activity of this variant was the same as when only PC/PS was included. To investigate whether the loss of specific neutral lipid enhancement in APC-I18V affected its ability to initiate cytoprotective signaling via EPCR-PAR-1 on endothelial cells, the capacity of APC-I18V to inhibit thrombin-induced endothelial cell barrier permeability was assessed. When cells were pre-treated with either wild type APC or APC-I18V, there was a significant enhancement in barrier integrity and attenuation of thrombin-induced permeability (P<0.05), demonstrating that loss of PE/GlyCer enhancement of APC anticoagulant activity does not adversely affect EPCR binding and EPCR/PAR-1 cytoprotective signaling. Collectively, these results suggest PE and GlyCer enhancement of APC anticoagulant activity is mediated by increased sensitivity to protein S, and that Ile-18 in the APC Gla domain is critical for mediating APC-specific functional enhancement by PE/GlyCer.