Articles de revues : « Binding, remnants used in »

1

Borensztajn, J., T. J. Kotlar et C. A. Matza. « Heparin-binding apoproteins. Effects on lipoprotein lipase and hepatic uptake of remnants ». Biochemical Journal 233, n^o 3 (1 février 1986) : 909–12. http://dx.doi.org/10.1042/bj2330909.

Texte intégral

Résumé :

Apoprotein-free heparin-binding and non-binding chylomicrons were used as substrates to test the effects on lipoprotein lipase activity of (a) chylomicron protein I; (b) the mixture of proteins I, II and apoprotein E and (c) human beta 2-glycoprotein I. No activation of the enzyme was observed with any of those apoproteins. When rats were injected simultaneously with [3H]cholesterol-labelled heparin-binding chylomicrons (containing proteins I and II) and [14C]cholesterol-labelled non-binding chylomicrons, no differences were detected between the rates of removal from circulation of those two types of particles. Clearance of chylomicrons from circulation was accompanied by the incorporation of 3H and 14C labels into the livers at similar rates. It is concluded that proteins I, II and apoprotein E have no effect on the degradation of chylomicrons by lipoprotein lipase and that the hepatic recognition of remnants does not appear to be affected by proteins I and II.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Boullé, Mikaël, Laurianne Davignon, Keïs Nabhane Saïd Halidi, Salomé Guez, Emilie Giraud, Marcel Hollenstein et Fabrice Agou. « High-Content RNAi Phenotypic Screening Unveils the Involvement of Human Ubiquitin-Related Enzymes in Late Cytokinesis ». Cells 11, n^o 23 (30 novembre 2022) : 3862. http://dx.doi.org/10.3390/cells11233862.

Texte intégral

Résumé :

CEP55 is a central regulator of late cytokinesis and is overexpressed in numerous cancers. Its post-translationally controlled recruitment to the midbody is crucial to the structural coordination of the abscission sequence. Our recent evidence that CEP55 contains two ubiquitin-binding domains was the first structural and functional link between ubiquitin signaling and ESCRT-mediated severing of the intercellular bridge. So far, high-content screens focusing on cytokinesis have used multinucleation as the endpoint readout. Here, we report an automated image-based detection method of intercellular bridges, which we applied to further our understanding of late cytokinetic signaling by performing an RNAi screen of ubiquitin ligases and deubiquitinases. A secondary validation confirmed four candidate genes, i.e., LNX2, NEURL, UCHL1 and RNF157, whose downregulation variably affects interconnected phenotypes related to CEP55 and its UBDs, as follows: decreased recruitment of CEP55 to the midbody, increased number of midbody remnants per cell, and increased frequency of intercellular bridges or multinucleation events. This brings into question the Notch-dependent or independent contributions of LNX2 and NEURL proteins to late cytokinesis. Similarly, the role of UCHL1 in autophagy could link its function with the fate of midbody remnants. Beyond the biological interest, this high-content screening approach could also be used to isolate anticancer drugs that act by impairing cytokinesis and CEP55 functions.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Mamo, John C. L., Gerald F. Watts, P. Hugh R. Barrett, Darrin Smith, Anthony P. James et Sebely Pal. « Postprandial dyslipidemia in men with visceral obesity : an effect of reduced LDL receptor expression ? » American Journal of Physiology-Endocrinology and Metabolism 281, n^o 3 (1 septembre 2001) : E626—E632. http://dx.doi.org/10.1152/ajpendo.2001.281.3.e626.

Texte intégral

Résumé :

Postprandial lipemia after an oral fat challenge was studied in middle-aged men with visceral obesity. The two groups had similar plasma cholesterol levels, but obese subjects had higher levels of plasma triglyceride and reduced amounts of high-density cholesterol. Fasting plasma insulin was fourfold greater in obese subjects because of concomitant insulin resistance, with a calculated HOMA score of 3.1 ± 0.6 vs. 0.8 ± 0.2, respectively. Plasma apolipoprotein B48(apoB48) and retinyl palmitate (RP) after an oral fat challenge were used to monitor chylomicron metabolism. Compared with lean subjects, the fasting concentration of apoB48 was more than twofold greater in obese individuals, suggestive of an accumulation of posthydrolyzed particles. After the oral lipid load, the incremental areas under the apoB48 and RP curves (IAUC) were both significantly greater in obese subjects (apoB48: 97 ± 17 vs. 44 ± 12 μg · ml−1 · h; RP: 3,120 ± 511 vs. 1,308 ± 177 U · ml−1 · h, respectively). A delay in the conversion of chylomicrons to remnants probably contributed to postprandial dyslipidemia in viscerally obese subjects. The triglyceride IAUC was 68% greater in obese subjects (4.7 ± 0.6 vs. 2.8 ± 0.8 mM · h, P< 0.06). Moreover, peak postprandial triglyceride was delayed by ∼2 h in obese subjects. The reduction in triglyceride lipolysis in vivo did not appear to reflect changes in hydrolytic enzyme activities. Postheparin plasma lipase rates were found to be similar for lean and obese subjects. In this study, low-density lipoprotein (LDL) receptor expression on monunuclear cells was used as a surrogate marker of hepatic activity. We found that, in obese subjects, the binding of LDL was reduced by one-half compared with lean controls (70.9 ± 15.07 vs. 38.9 ± 4.6 ng LDL bound/μg cell protein, P = 0.02). Because the LDL receptor is involved in the removal of proatherogenic chylomicron remnants, we suggest that the hepatic clearance of these particles might be compromised in insulin-resistant obese subjects. Premature and accelerated atherogenesis in viscerally obese, insulin-resistant subjects may in part reflect delayed clearance of postprandial lipoprotein remnants.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Zheng, Yifan, Aidan F. Pierce, Willi L. Wagner, Hassan A. Khalil, Zi Chen, Andrew B. Servais, Maximilian Ackermann et Steven J. Mentzer. « Functional Adhesion of Pectin Biopolymers to the Lung Visceral Pleura ». Polymers 13, n^o 17 (2 septembre 2021) : 2976. http://dx.doi.org/10.3390/polym13172976.

Texte intégral

Résumé :

Pleural injuries and the associated “air leak” are the most common complications after pulmonary surgery. Air leaks are the primary reason for prolonged chest tube use and increased hospital length of stay. Pectin, a plant-derived heteropolysaccharide, has been shown to be an air-tight sealant of pulmonary air leaks. Here, we investigate the morphologic and mechanical properties of pectin adhesion to the visceral pleural surface of the lung. After the application of high-methoxyl citrus pectin films to the murine lung, we used scanning electron microscopy to demonstrate intimate binding to the lung surface. To quantitatively assess pectin adhesion to the pleural surface, we used a custom adhesion test with force, distance, and time recordings. These assays demonstrated that pectin–glycocalyceal tensile adhesive strength was greater than nanocellulose fiber films or pressure-sensitive adhesives (p < 0.001). Simultaneous videomicroscopy recordings demonstrated that pectin–glycocalyceal adhesion was also stronger than the submesothelial connective tissue as avulsed surface remnants were visualized on the separated pectin films. Finally, pleural abrasion and hyaluronidase enzyme digestion confirmed that pectin binding was dependent on the pleural glycocalyx (p < 0.001). The results indicate that high methoxyl citrus pectin is a promising sealant for the treatment of pleural lung injuries.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Sleiderink, Remco, et Ben van der Have. « Een nieuw fragment van handschrift A van de Roman der Lorreinen (Michigan State University, Criminology Collection, XX KJC7690.A48 1687) ». Tijdschrift voor Nederlandse Taal- en Letterkunde 137, n^o 2 (1 janvier 2021) : 102–21. http://dx.doi.org/10.5117/tntl2021.2.001.slei.

Texte intégral

Résumé :

Abstract Among the many books in Michigan State University’s Criminology Collection is a Corpus juris militaris, published in Germany in 1687. Its binding contains four small parchment strips with medieval Dutch verses. Although the strips are still attached in the spine, the verses can be identified as belonging to the Roman der Lorreinen, and more specifically as remnants of manuscript A, written in the duchy of Brabant in the second quarter of the fourteenth century. Manuscript A originally must have consisted of over 400 leaves, containing more than 150.000 verses (note: there are no complete manuscripts of the Roman der Lorreinen). Only 7% of manuscript A has been preserved in several European libraries, mainly in Germany. The new fragment suggests that manuscript A was used as binding material not earlier than the end of the seventeenth century (after 1687). The newly found verses are from the first part of the Roman der Lorreinen, which was an adaptation of the Old French chanson de geste Garin le Loherenc. This article offers a first edition and study of the verses, comparing them to the Old French counterparts. This comparison offers additional evidence for the earlier hypothesis that manuscript A contained the same adaptation of Garin le Loherenc as the fragmentary manuscripts B and C.

Styles APA, Harvard, Vancouver, ISO, etc.

6

WENDLING, MIRIAM. « The reception of Hermann of Reichenau at St Michelsberg : some observations on fragments of interval notation ». Plainsong and Medieval Music 24, n^o 2 (25 septembre 2015) : 113–27. http://dx.doi.org/10.1017/s0961137115000108.

Texte intégral

Résumé :

ABSTRACTThe bindings of a large number of manuscripts formerly held in the library of the Benedictine monastery of St Michelsberg in Bamberg preserve fragments of medieval chantbooks documenting a culture in which practical singing and music theory were closely intertwined. These remnants, the work of generations of scribes, reveal a sustained concern for correctness ranging from the use of pitch-clarifying neume notations, to the use of letters, to the recording of melodies along lines prescribed in theoretical works. The influence the music theorist Hermann of Reichenau on St Michelsberg's own theorist, Frutolf, raises two questions. First, what is the nature of the relationship between practical chant and music theory books at St Michelsberg? Second, how was Hermann's notation used at the monastery?

Styles APA, Harvard, Vancouver, ISO, etc.

7

Doungudomdacha, Sombhun, Alla Volgina et Joseph M. DiRienzo. « Evidence that the cytolethal distending toxin locus was once part of a genomic island in the periodontal pathogen Aggregatibacter (Actinobacillus) actinomycetemcomitans strain Y4 ». Journal of Medical Microbiology 56, n^o 11 (1 novembre 2007) : 1519–27. http://dx.doi.org/10.1099/jmm.0.47273-0.

Texte intégral

Résumé :

The authors have previously shown that the periodontal pathogen Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans Y4 contains an operon for a genotoxin known as the cytolethal distending toxin (Cdt). The cdt locus in strain Y4 is flanked by remnants of heterologous plasmid and integrase sequences. In this study, the DNA sequence immediately downstream from the cdt locus on the Y4 chromosome was examined. The extended sequence contained a region that had all the characteristics of a typical bacterial pathogenicity or genomic island. The genomic island (GIY4-1) was approximately 22 kb long, was flanked by a bacteriophage attachment (att) sequence and contained a full-length integrase/resolvase gene (xerD). A total of 22 complete and partial ORFs represented putative DNA replication/DNA binding/conjugation proteins as well as hypothetical proteins. GIY4-1 was most closely related to putative genomic islands in Haemophilus ducreyi 35000HP and Haemophilus influenzae 86-028NP and to a chromosomal region in Haemophilus somnus 129PT. GIY4-1 was not present in HK1651, which was used as the prototype strain for genomic sequencing of A. actinomycetemcomitans. Several sequences in GIY4-1 were homologous to ORFs found on the A. actinomycetemcomitans plasmid pVT745. None of the identified ORFs in GIY4-1 appeared to encode potential virulence genes. However, several unique observations supported the possibility that the cdt locus of A. actinomycetemcomitans Y4 was originally contained within the genomic island.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Pawar, Vipul Mohan, Rashmi Hosalkar et Janaki Iyer. « Immunohistochemical Evaluation of Calretinin and Cytokeratin-19 in Odontogenic Keratocyst and Ameloblastoma : A Retrospective Study ». Journal of Contemporary Dentistry 5, n^o 2 (2015) : 98–103. http://dx.doi.org/10.5005/jp-journals-10031-1116.

Texte intégral

Résumé :

ABSTRACT The odontogenic epithelial remnants, i.e. cell rests of Serre and Malassez, are formed from dental lamina and Hertwig's epithelial root sheath respectively, may proliferate and have role in pathogenesis of odontogenic cysts and tumors. Odontogenic keratocyst (OKC) is the most common and aggressive cyst of the dental lamina origin. Ameloblastoma, the second most common odontogenic tumor (OT), is a clinically benign and locally invasive polymorphic neoplasia. Differentiation of OKC from ameloblastoma sometimes poses a diagnostic dilemma, thus necessitating the need to differentiate between the two (especially unicystic ameloblastoma and OKC). Calretinin, a calcium binding protein, functions as a calcium buffer and a regulator of apoptosis. Some studies have shown its expression in parakeratinized OKC, unicystic and solid ameloblastoma, but not in other OTs. Calretinin may thus provide a better understanding of the biological behavior and tumorogenesis of ameloblastoma. cytokeratin (CK)-19 is a type I cytokeratin, has been found to be a reliable marker of epithelial differentiation. The intense expression of CK-19 is useful for identification of odontogenic epithelial components, thus suggesting their potential for proliferation to form epithelial odontogenic cysts and tumors. The aim of this study is to evaluate calretinin and Ck-19 in OKC and ameloblastoma. For this retrospective study, 20 formalin fixed paraffin embedded tissue samples of histopathologically proven OKC and ameloblastoma each, retrieved from the department of oral pathology was used. The results will be evaluated by using immunohistochemical analysis. How to cite this article Pawar VM, Patel S, Pathak J, Swain N, Hosalkar R, Iyer J. Immunohistochemical Evaluation of Calretinin and Cytokeratin-19 in Odontogenic Keratocyst and Ameloblastoma: A Retrospective Study. J Contemp Dent 2015;5(2):98-103.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Watson, T. D., C. E. Tan, M. McConnell, S. K. Clegg, L. F. Squires et C. J. Packard. « Measurement and physiological significance of lipoprotein and hepatic lipase activities in preheparin plasma ». Clinical Chemistry 41, n^o 3 (1 mars 1995) : 405–12. http://dx.doi.org/10.1093/clinchem/41.3.405.

Texte intégral

Résumé :

Abstract A radiochemical method for selective measurement of postheparin lipase activities was adapted to analyze lipoprotein lipase and hepatic lipase in preheparin plasma. The assay sensitivity was increased about four-fold by doubling both the volume of plasma used and the volume of lipolytic products taken for liquid scintillation counting, and was further improved by increasing the incubation period by 50% to 90 min. Rabbit antiserum to human hepatic lipase was unsuitable for the selective measurement of lipoprotein lipase because of apparent endogenous lipolytic activity. Preheparin hepatic lipase, however, was sensitive to inactivation by sodium dodecyl sulfate (SDS), the inhibition being greatest (> 90%) for plasma incubated with an equal volume of 40 mmol/L SDS. Intra- and interassay CVs for the two enzymes were 12.5-14.6% and 17.4-19.7%, respectively. In a cross-sectional study of 84 healthy subjects, pre- and postheparin hepatic lipase activities were higher in men than women, were correlated with indices of obesity, and were significantly correlated with one another, which explained the association of the former with plasma concentrations of high-density lipoprotein (HDL), HDL2, and small, dense low-density lipoproteins. There was no significant relationship between pre- and postheparin lipoprotein lipase activities, but the former were correlated with plasma concentrations of free fatty acids (FFA) and very-low-density lipoprotein. Apparently, preheparin activities of hepatic lipase, but not of lipoprotein lipase, may be a useful measure of the physiological function of "whole body" enzyme activity in cross-sectional and metabolic studies, where heparinization is not possible. Preheparin lipoprotein lipase activities, however, may reflect displacement of the enzyme by FFA and subsequent binding to remnants of triglyceride-rich lipoproteins.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Windler, E., J. Greeve, B. Levkau, V. Kolb-Bachofen, W. Daerr et H. Greten. « The human asialoglycoprotein receptor is a possible binding site for low-density lipoproteins and chylomicron remnants ». Biochemical Journal 276, n^o 1 (15 mai 1991) : 79–87. http://dx.doi.org/10.1042/bj2760079.

Texte intégral

Résumé :

Binding and internalization of chylomicron remnants from rat mesenteric lymph by HepG2 cells was inhibited by both excess remnants and low-density lipoprotein (LDL) to the same extent. Ligand blots revealed binding of remnants and LDL to the LDL receptor. Measures regulating LDL receptor activity greatly influenced the binding of remnants: ethinyloestradiol, the hydroxymethylglutaryl-CoA reductase inhibitor pravastatin and the absence of LDL all increased binding, whereas high cell density or the presence of LDL decreased binding. Also, asialofetuin, asialomucin, the neoglycoprotein galactosyl-albumin and an antibody against the asialoglycoprotein receptor all decreased substantially the binding of remnants. At high cell density, binding internalization and degradation of chylomicron remnants was inhibited by up to 70-80%, yet binding of LDL was inhibited by no more than 20-30%. In cross-competition studies, the binding of 125I-asialofetuin was efficiently competed for by asialofetuin itself or by the antibody, and also by LDL and remnants, yet remnants displayed an approx. 100-fold higher affinity than LDL. Likewise, remnants of human triacylglycerol-rich lipoproteins and asialofetuin interfered with each others' binding to HepG2 cells or human liver membranes. It is concluded that the LDL receptor mediates the internalization of chylomicron remnants into hepatocytes depending on its activity, according to demand for cholesterol. Additionally, the asialoglycoprotein receptor may contribute to the endocytosis of LDL, but predominantly of chylomicron remnants.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Yu, Kenneth C. W., Darrin Smith, Akira Yamamoto, Akito Kawaguchi, Mariko Harada-Shiba, Taku Yamamura et John C. L. Mamo. « Phagocytic Degradation of Chylomicron Remnants by Fibroblasts from Subjects with Homozygous Familial Hypercholesterolemia ». Clinical Science 92, n^o 2 (1 février 1997) : 197–203. http://dx.doi.org/10.1042/cs0920197.

Texte intégral

Résumé :

1. Familial hypercholesterolaemia is a common genetic abnormality in man characterized by premature atherogenesis as a consequence of disturbed lipoprotein metabolism. Chylomicrons, which represent intestinally derived lipoproteins, are cleared poorly in familial hypercholesterolaemia which may explain the increased retention of chylomicron remnants in arterial fatty lesions. However, cellular uptake of chylomicron remnants in familial hypercholesterolaemia remains unclear. This study determined the quantitative significance of non-low-density lipoprotein receptor-mediated uptake in fibroblasts from subjects with homozygous familial hypercholesterolaemia. 2. The metabolism of chylomicron remnants was assessed in fibroblasts from subjects with homozygous familial hypercholesterolaemia who lack low-density lipoprotein receptors. Compared with fibroblasts from normolipidaemic subjects, binding and degradation of chylomicron remnants was reduced by about two-thirds. Nevertheless, degradation of chylomicron remnants in cells from subjects with familial hypercholesterolaemia persisted in the absence of functioning low-density lipoprotein receptors. 3. Binding of chylomicron remnants to fibroblasts from subjects with familial hypercholesterolaemia was saturable. Unlabelled chylomicron remnants competed efficiently for binding but unlabelled low-density lipoprotein or a monoclonal antibody specific to the human low-density lipoprotein receptor had little effect on binding or degradation. 4. Polyinosinic acid did not alter binding and degradation of chylomicron remnants by fibroblasts from subjects with familial hypercholesterolaemia, ruling out involvement of the scavenger receptor. Lactoferrin was found to inhibit binding and degradation of chylomicron remnants by fibroblasts from subjects with familial hypercholesterolaemia by approximately 50%, implicating involvement of the α2-macroglobulin receptor. 5. Cytochalasin D blocked degradation of chylomicron remnants at 37°C in fibroblasts from subjects with familial hypercholesterolaemia by more than 80% but had no effect on binding at 4°C, consistent with a phagocytic uptake pathway. Collectively, the data suggest that chylomicron remnants bind to a cell-surface protein which initiates phagocytosis and that lactoferrin interferes with binding to this putative cell-surface protein. Phagocytic uptake of chylomicron remnants provides an additional mechanism whereby cells from subjects with familial hypercholesterolaemia can accumulate lipid.

Styles APA, Harvard, Vancouver, ISO, etc.

12

van Bree, Elisabeth J., Soufyan Lakbir, Carmen Rubio-Alarcón, Renske de Wit, Anne Bolijn, Pien Delis-van Diemen, Marianne Tijssen et al. « Abstract 401 : The impact of DNA structural variants on PRKN gene function and colorectal cancer pathogenesis ». Cancer Research 84, n^o 6_Supplement (22 mars 2024) : 401. http://dx.doi.org/10.1158/1538-7445.am2024-401.

Texte intégral

Résumé :

Abstract Background: Cancer is caused by somatic DNA alterations, such as single nucleotide variants, somatic copy number alterations and structural variants (SVs). PRKN is among the genes most frequently affected by SVs in colorectal cancer (CRC), with 37% of primary cancers and 56% of metastatic lesions having focal deletions in PRKN. PRKN encodes the E3 ubiquitin ligase Parkin, which regulates the biological activity and degradation of substrates via post-translational modifications. The genomic location of PRKN is within a common fragile site. Therefore, it remains unclear whether the high frequency of SVs in PRKN are passenger events due to genomic instability or driver events of CRC pathogenesis. Aim: Our study aims to investigate the impact of SVs on the functionality of Parkin in CRC pathogenesis. Methods: We used publicly available DNA deep whole genome sequencing (WGS) and tumor-matched RNA sequencing data (n=394) to estimate the impact of SVs in PRKN on tumor biology. For this, the transcriptome-wide p-value distribution generated by differential expression analysis was used as a measure of biological impact. The HCT116-MLH1-repaired cell line and patient-derived adenoma organoids were genetically modified using CRISPR/Cas9 to mimic the SVs observed in patient material and analyze their impact. RNA-sequencing, whole proteome and ubiquitin remnant-specific proteomics were used to assess the effect of SVs on gene function and identify altered biological processes. Results: Analysis of WGS and RNA sequencing of patient material showed that SVs in PRKN have a large impact on CRC biology, comparable to the impact of mutations in TP53 (impact score 0.379 vs 0.332). The most pronounced effects are seen in the ubiquitin-like, RING0 and RING1 domains. These domains are important for recognition and/or binding to ubiquitin, E2 ubiquitin-conjugating enzymes and substrates. In the HCT116-MLH1-repaired CRC cell line, hemizygous introduction of an SV in PRKN had minimal effects on genome-wide gene expression. In contrast, homozygous deletion altered the expression of nearly 2000 genes. Analyses of ubiquitin motif remnants showed differential ubiquitination of proteins involved in DNA repair following the introduction of an SV in PRKN in the CRC cell line. These proteins include TOP2A (Log2 fold change (L2FC) = -3.69, P = 5.71−5), RAD18 (L2FC = -4.55, P = 1.35−4) and Spartan (SPRTN; L2FC = -2.57, P = 7.43−4). Conclusion: SVs in PRKN have a high impact on tumor biology and result in aberrant gene expression and post-translational modifications of proteins related to DNA repair. Further research will expand to the patient-derived adenoma organoids and focus on understanding if these recurrent somatic alterations contribute to genomic instability and the development of CRC pathogenesis. Citation Format: Elisabeth J. van Bree, Soufyan Lakbir, Carmen Rubio-Alarcón, Renske de Wit, Anne Bolijn, Pien Delis-van Diemen, Marianne Tijssen, Ellen Stelloo, Harma Feitsma, Gerrit A. Meijer, Beatriz Carvalho, Sanne Abeln, Remond J. Fijneman. The impact of DNA structural variants on PRKN gene function and colorectal cancer pathogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 401.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Borensztajn, J., T. J. Kotlar et S. Y. Chang. « Apoprotein-independent binding of chylomicron remnants to rat liver membranes ». Biochemical Journal 279, n^o 3 (1 novembre 1991) : 769–73. http://dx.doi.org/10.1042/bj2790769.

Texte intégral

Résumé :

Rat lymph chylomicrons and chylomicron remnants were treated with trypsin or Pronase. The ability of the resulting apoprotein-free lipoproteins to be taken up by the isolated perfused rat liver, and to bind to isolated rat liver membranes, was examined. Compared with control lipoproteins, the apoprotein-free chylomicrons and remnants retained unaltered their capacity to be differentiated by the intact liver and by the isolated membranes. Further, control remnants and apoprotein-free remnants competed for binding to the isolated membranes. We conclude that apoproteins are not required for the hepatic differentiation between chylomicrons and remnants, and suggest that the lipoprotein phospholipids may play a direct role in this process.

Styles APA, Harvard, Vancouver, ISO, etc.

14

ELSEGOOD, Caryn L., Sebely PAL, Paul D. ROACH et John C. L. MAMO. « Binding and uptake of chylomicron remnants by primary and THP-1 human monocyte-derived macrophages : determination of binding proteins ». Clinical Science 101, n^o 2 (18 juin 2001) : 111–19. http://dx.doi.org/10.1042/cs1010111.

Texte intégral

Résumé :

The binding and uptake of chylomicron remnants by human macrophages was studied in order to resolve paradoxical observations that have described the putative mechanisms by which postprandial lipoproteins induce foam cell formation. Chylomicron remnants bound to human monocyte-derived macrophages (HMMs) and to the transformed monocytic cell line THP-1 with high affinity (Kd of approx. 5.5 µg of chylomicron remnant protein/ml). Binding was found to be saturable for both cell types, and was strongly inhibited in the presence of unlabelled chylomicron remnants. Ligand blot studies with colloidal-gold-labelled chylomicron remnants identified two cell surface binding sites on both HMMs and THP-1 cells, with molecular masses of approx. 128 kDa and 43 kDa. The high-molecular-mass binding site was found to be the low-density lipoprotein (LDL) receptor, based on the strong inhibition of chylomicron remnant binding in the presence of unlabelled LDL, Fab2 antibody fragments to the LDL receptor or calcium chelators. Competition studies suggested that, in HMMs, the LDL receptor appeared to facilitate approximately half of the total chylomicron remnant uptake. In contrast, the LDL receptor was not significantly involved in macrophage uptake of chylomicron remnants by THP-1 cells. The identity of the 43 kDa binding site is presently unknown, but, importantly, expression was not inhibited as a consequence of sterol loading, which was induced by incubating HMMs and THP-1 cells with 25-hydroxycholesterol. In contrast, the expression of the LDL receptor was substantially attenuated following lipid loading. Collectively, our data suggest that, while the macrophage LDL receptor can bind chylomicron remnants and facilitate uptake in non-lipid-loaded HMMs, other sterol-insensitive sites are responsible for the unabated uptake of chylomicron remnants by macrophages. We propose that the 43 kDa macrophage chylomicron remnant binding protein may be a candidate for the sterol loading of macrophages.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Faraone, Christopher A. « Aeschylus' ὓμνος δέσμιος (Eum. 306) and Attic judicial curse tablets ». Journal of Hellenic Studies 105 (novembre 1985) : 150–54. http://dx.doi.org/10.2307/631528.

Texte intégral

Résumé :

When the Erinyes catch up with Orestes in Athens they find him clutching the archaic wooden statue of Athena and invoking her aid along with that of Apollo (Eum. 235 ff.). The Erinyes scorn his prayers and bid him hear their ‘binding song’: ὕμνον δ’ ἀκούσῃ τόνδε δέσμιον (306). Wecklein in his 1888 edition of the play remarked ‘erinnert an magische Künste’ and quoted Laws 933a, where Plato, discussing murder by poison, makes brief mention of the popular belief in sorcerers, incantations and binding spells (καταδέσεις). Subsequent commentators repeat Wecklein's brief note nearly verbatim and then elaborate it along two different lines, either claiming some vague Orphic source (Thomson 1938) or citing Wuensch's Defixionum Tabellae Atticae (Blass 1907; Groeneboom 1952). More recently, Lebeck argued that the ostensible title (‘binding song’) is incompatible with the actual content of the stasimon (Apollo's encroachment on the Erinyes’ power); she concluded that the title is irrelevant or at best only of secondary importance.’ Thus on the whole, this ὕμνος δέσμιος has been treated as a remnant of magical or chthonic lore too obscure to have any real bearing on our understanding of the immediate dramatic situation in Eumenides. I shall argue to the contrary that the song is closely related to a specific kind of curse tablet used to affect the outcome of law cases in Athens as early as the 5th century bc, and as such it is important to the dramatic context of a tragedy which depicts the mythical foundation of Athens’ first homicide court.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Qin, Jin-Hong, Qing Zhang, Zhi-Ming Zhang, Yi Zhong, Yang Yang, Bao-Yu Hu, Guo-Ping Zhao et Xiao-Kui Guo. « Identification of a Novel Prophage-Like Gene Cluster Actively Expressed in Both Virulent and Avirulent Strains of Leptospira interrogans Serovar Lai ». Infection and Immunity 76, n^o 6 (24 mars 2008) : 2411–19. http://dx.doi.org/10.1128/iai.01730-07.

Texte intégral

Résumé :

ABSTRACT DNA microarray analysis was used to compare the differential gene expression profiles between Leptospira interrogans serovar Lai type strain 56601 and its corresponding attenuated strain IPAV. A 22-kb genomic island covering a cluster of 34 genes (i.e., genes LA0186 to LA0219) was actively expressed in both strains but concomitantly upregulated in strain 56601 in contrast to that of IPAV. Reverse transcription-PCR assays proved that the gene cluster comprised five transcripts. Gene annotation of this cluster revealed characteristics of a putative prophage-like remnant with at least 8 of 34 sequences encoding prophage-like proteins, of which the LA0195 protein is probably a putative prophage CI-like regulator. The transcription initiation activities of putative promoter-regulatory sequences of transcripts I, II, and III, all proximal to the LA0195 gene, were further analyzed in the Escherichia coli promoter probe vector pKK232-8 by assaying the reporter chloramphenicol acetyltransferase (CAT) activities. The strong promoter activities of both transcripts I and II indicated by the E. coli CAT assay were well correlated with the in vitro sequence-specific binding of the recombinant LA0195 protein to the corresponding promoter probes detected by the electrophoresis mobility shift assay. On the other hand, the promoter activity of transcript III was very low in E. coli and failed to show active binding to the LA0195 protein in vitro. These results suggested that the LA0195 protein is likely involved in the transcription of transcripts I and II. However, the identical complete DNA sequences of this prophage remnant from these two strains strongly suggests that possible regulatory factors or signal transduction systems residing outside of this region within the genome may be responsible for the differential expression profiling in these two strains.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Windler, E. E. T., J. Greeve, W. H. Daerr et H. Greten. « Binding of rat chylomicrons and their remnants to the hepatic low-density-lipoprotein receptor and its role in remnant removal ». Biochemical Journal 252, n^o 2 (1 juin 1988) : 553–61. http://dx.doi.org/10.1042/bj2520553.

Texte intégral

Résumé :

Binding and uptake of rat chylomicrons of different metabolic stages by the hepatic low-density-lipoprotein (LDL) receptor were studied. Pure chylomicrons, characterized by apolipoprotein B-48 devoid of contaminating B-100, were labelled in their cholesteryl esters. Lymph chylomicrons and serum chylomicrons, enriched in apolipoprotein E and the C-apolipoproteins, bound poorly to rat hepatic membranes. In contrast, chylomicron remnants, containing the apolipoproteins B-48 and E, bound with high affinity. Specific binding of remnants was virtually completely competed for by LDL free of apolipoprotein E. In addition, in ligand blots both remnants and LDL associated with the same protein with an Mr characteristic of the LDL receptor. Uptake of remnants during a single pass through isolated perfused rat livers was decreased to about 50% by an excess of LDL. It is concluded that rat chylomicron remnants are a ligand of the hepatic LDL receptor. The much higher affinity as compared with LDL is mediated by apolipoprotein E but not B-48, and is inhibited by the C-apolipoproteins. This explains why serum chylomicrons are not taken up by the liver, whereas remnants are rapidly removed from the circulation. Results from experiments in vivo suggest that the LDL receptor makes an important contribution to the hepatic uptake of remnants and may be the principal binding site of the liver responsible for remnant removal.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Berndt, MC, BH Chong, HA Bull, H. Zola et PA Castaldi. « Molecular characterization of quinine/quinidine drug-dependent antibody platelet interaction using monoclonal antibodies ». Blood 66, n^o 6 (1 décembre 1985) : 1292–301. http://dx.doi.org/10.1182/blood.v66.6.1292.1292.

Texte intégral

Résumé :

Abstract Two murine monoclonal antibodies, FMC 25 and AN 51, directed against distinct epitopes on the glycoprotein Ib complex, have been used to further define the mechanism of quinine/quinidine drug-dependent antibody interaction with platelets. FMC 25, directed against an epitope on glycoprotein IX, had no effect on platelet aggregation induced by collagen or adenosine diphosphate and little, if any, effect on ristocetin-induced platelet agglutination. FMC 25 and its (Fab)2 fragment, however, were potent inhibitors of drug-dependent antibody- induced platelet aggregation and blocked binding of drug-dependent antibody to platelets as assessed by indirect platelet immunofluorescence. In contrast, AN 51, directed against an epitope on the alpha-subunit of glycoprotein Ib, blocked ristocetin-induced, factor VIII/von Willebrand factor (FVIII/vWF)-dependent platelet agglutination but not drug-dependent antibody-induced platelet aggregation or binding of drug-dependent antibody to platelets. Selective proteolytic removal of the majority of the alpha-subunit of glycoprotein Ib (glycocalicin) from platelets by treatment with calcium- dependent protease did not affect binding of drug-dependent antibody. In addition, a quinidine-dependent antiplatelet antibody immunoprecipitated glycoprotein Ib complex from normal platelets and the membrane-associated proteolytic remnant of the glycoprotein Ib complex from calcium-dependent protease-treated platelets. Preincubation of drug-dependent antibody with purified glycoprotein Ib complex inhibited subsequent binding of antibody to platelets, but the separated components, glycoprotein Ib and glycoprotein IX, were both ineffective, suggesting that the normal interaction between glycoprotein Ib and glycoprotein IX in the intact complex was necessary for drug-dependent antibody recognition. The functional response of platelets to drug-dependent antibody was not mediated by way of platelet Fc receptor, since aggregation of washed platelets by acetone- aggregated IgG was not inhibited by FMC 25 (Fab)2. FVIII/vWF was not required for drug-dependent antibody-induced platelet aggregation. The combined evidence is consistent with quinine/quinidine-dependent antibody-platelet interaction occurring by way of a FVIII/vWF- independent, Fc receptor-independent mechanism that probably involves binding of antibody to glycoprotein IX or the beta-subunit of glycoprotein Ib or both.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Berndt, MC, BH Chong, HA Bull, H. Zola et PA Castaldi. « Molecular characterization of quinine/quinidine drug-dependent antibody platelet interaction using monoclonal antibodies ». Blood 66, n^o 6 (1 décembre 1985) : 1292–301. http://dx.doi.org/10.1182/blood.v66.6.1292.bloodjournal6661292.

Texte intégral

Résumé :

Two murine monoclonal antibodies, FMC 25 and AN 51, directed against distinct epitopes on the glycoprotein Ib complex, have been used to further define the mechanism of quinine/quinidine drug-dependent antibody interaction with platelets. FMC 25, directed against an epitope on glycoprotein IX, had no effect on platelet aggregation induced by collagen or adenosine diphosphate and little, if any, effect on ristocetin-induced platelet agglutination. FMC 25 and its (Fab)2 fragment, however, were potent inhibitors of drug-dependent antibody- induced platelet aggregation and blocked binding of drug-dependent antibody to platelets as assessed by indirect platelet immunofluorescence. In contrast, AN 51, directed against an epitope on the alpha-subunit of glycoprotein Ib, blocked ristocetin-induced, factor VIII/von Willebrand factor (FVIII/vWF)-dependent platelet agglutination but not drug-dependent antibody-induced platelet aggregation or binding of drug-dependent antibody to platelets. Selective proteolytic removal of the majority of the alpha-subunit of glycoprotein Ib (glycocalicin) from platelets by treatment with calcium- dependent protease did not affect binding of drug-dependent antibody. In addition, a quinidine-dependent antiplatelet antibody immunoprecipitated glycoprotein Ib complex from normal platelets and the membrane-associated proteolytic remnant of the glycoprotein Ib complex from calcium-dependent protease-treated platelets. Preincubation of drug-dependent antibody with purified glycoprotein Ib complex inhibited subsequent binding of antibody to platelets, but the separated components, glycoprotein Ib and glycoprotein IX, were both ineffective, suggesting that the normal interaction between glycoprotein Ib and glycoprotein IX in the intact complex was necessary for drug-dependent antibody recognition. The functional response of platelets to drug-dependent antibody was not mediated by way of platelet Fc receptor, since aggregation of washed platelets by acetone- aggregated IgG was not inhibited by FMC 25 (Fab)2. FVIII/vWF was not required for drug-dependent antibody-induced platelet aggregation. The combined evidence is consistent with quinine/quinidine-dependent antibody-platelet interaction occurring by way of a FVIII/vWF- independent, Fc receptor-independent mechanism that probably involves binding of antibody to glycoprotein IX or the beta-subunit of glycoprotein Ib or both.

Styles APA, Harvard, Vancouver, ISO, etc.

20

Park, Anna, Denise M. Honey, Lihui Hou, Julie J. Bird, Christine Zarazinski, Michelle Searles, Christian Braithwaite et al. « Carbohydrate-Mediated Polyethylene Glycol Conjugation of TSH Improves Its Pharmacological Properties ». Endocrinology 154, n^o 3 (1 mars 2013) : 1373–83. http://dx.doi.org/10.1210/en.2012-2010.

Texte intégral

Résumé :

Abstract Thyrogen (thyrotropin alfa for injection), recombinant human TSH (rhTSH), has been successfully used to enhance diagnostic radioiodine scanning and thyroglobulin testing in the follow-up of patients with thyroid cancer and as an adjunctive treatment for radioiodine thyroid remnant ablation. However, the short half-life of rhTSH in the circulation requires a multidose regimen. We developed novel sialic acid-mediated and galactose-mediated conjugation chemistries for targeting polyethylene glycol (PEG) to the three N-linked glycosylation sites on the protein, to prolong plasma half-life by eliminating kidney filtration and potential carbohydrate-mediated clearance. Conjugates of different PEG sizes and copy numbers were screened for reaction yield, TSH receptor binding, and murine phamacokinetics/pharmacodynamics studies. The best performing of these products, a 40-kDa mono-PEGylated sialic acid-mediated conjugate, exhibited a 3.5-fold longer duration of action than rhTSH in rats, as a 5-fold lower affinity was more than compensated by a 23-fold extension of circulation half-life. Biochemical characterization confirmed conjugation through the sialic acids. Correlation of PEG distribution on the three N-linked glycosylation sites and the PEG effect on receptor binding supported the previously reported structure-function relationship of rhTSH glycosylation. This long-acting rhTSH has the potential to significantly improve patient convenience and provider flexibility while reducing potential side effects associated with a sudden elevation of serum TSH.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Lee, Hyeon Jeong, Cheol Ryong Ku, Arthur Cho, TaeHo Cho, ChaeEun Lee, Chan Woo Kang, Daham Kim, Yoon Hee Cho, JaeHyung Koo et Eun Jig Lee. « Acetate-Mediated Odorant Receptor OR51E2 Activation Results in Calcitonin Secretion in Parafollicular C-Cells : A Novel Diagnostic Target of Human Medullary Thyroid Cancer ». Biomedicines 11, n^o 6 (11 juin 2023) : 1688. http://dx.doi.org/10.3390/biomedicines11061688.

Texte intégral

Résumé :

Medullary thyroid cancer originates from parafollicular C-cells in the thyroid. Despite successful thyroidectomy, localizing remnant cancer cells in patients with elevated calcitonin and carcinoembryonic antigen levels remains a challenge. Extranasal odorant receptors are expressed in cells from non-olfactory tissues, including C-cells. This study evaluates the odorant receptor signals from parafollicular C-cells, specifically, the presence of olfactory marker protein, and further assesses the ability of the protein in localizing and treating medullary thyroid cancer. We used immunohistochemistry, immunofluorescent staining, Western blot, RNA sequencing, and real time-PCR to analyze the expression of odorant receptors in mice thyroids, thyroid cancer cell lines, and patient specimens. We used in vivo assays to analyze acetate binding, calcitonin secretion, and cAMP pathway. We also used positron emission tomography (PET) to assess C11-acetate uptake in medullary thyroid cancer patients. We investigated olfactory marker protein expression in C-cells in patients and found that it co-localizes with calcitonin in C-cells from both normal and cancer cell lines. Specifically, we found that OR51E2 and OR51E1 were expressed in thyroid cancer cell lines and human medullary thyroid cancer cells. Furthermore, we found that in the C-cells, the binding of acetate to OR51E2 activates its migration into the nucleus, subsequently resulting in calcitonin secretion via the cAMP pathway. Finally, we found that C11-acetate, a positron emission tomography radiotracer analog for acetate, binds competitively to OR51E2. We confirmed C11-acetate uptake in cancer cells and in human patients using PET. We demonstrated that acetate binds to OR51E2 in C-cells. Using C11-acetate PET, we identified recurrence sites in post-operative medullary thyroid cancer patients. Therefore, OR51E2 may be a novel diagnostic and therapeutic target for medullary thyroid cancer.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Sinnis, P., T. E. Willnow, M. R. Briones, J. Herz et V. Nussenzweig. « Remnant lipoproteins inhibit malaria sporozoite invasion of hepatocytes. » Journal of Experimental Medicine 184, n^o 3 (1 septembre 1996) : 945–54. http://dx.doi.org/10.1084/jem.184.3.945.

Texte intégral

Résumé :

Remnants of lipoproteins, intestinal chylomicrons, and very low density lipoprotein (VLDL), are rapidly cleared from plasma and enter hepatocytes. It has been suggested that remnant lipoproteins are initially captured in the space of Disse by heparan sulfate proteoglycans (HSPGs), and that their subsequent internalization into hepatocytes is mediated by members of the LDL-receptor gene family. Similarly to lipoprotein remnants, malaria sporozoites are removed from the blood circulation by the liver within minutes after injection by Anopheles mosquitoes. The sporozoite's surface is covered by the circumsporozoite protein (CS), and its region II-plus has been implicated in the binding of the parasites to glycosaminoglycan chains of hepatocyte HSPGs. Lactoferrin, a protein with antibacterial properties found in breast milk and neutrophil granules, is also rapidly cleared from the circulation by hepatocytes, and can inhibit the hepatic uptake of lipoprotein remnants. Here we provide evidence that sporozoites, lactoferrin, and remnant lipoproteins are cleared from the blood by similar mechanisms. CS, lactoferrin, and remnant lipoproteins compete in vitro and in vivo for binding sites on liver cells. The relevance of this binding event for sporozoite infectivity is highlighted by our demonstration that apoliprotein E-enriched beta-VLDI and lactoferrin inhibit sporozoite invasion of HepG2 cells. In addition, malaria sporozoites are less infective in LDL-receptor knockout (LDLR -/-) mice maintained on a high fat diet, as compared with littermates maintained on a normal diet. We conclude that the clearance of lipoprotein remnants and sporozoites from the blood is mediated by the same set of highly sulfated HSPGs on the hepatocyte plasma membrane.

Styles APA, Harvard, Vancouver, ISO, etc.

23

Miyazaki, Y., S. Nomura, T. Miyake, H. Kagawa, C. Kitada, H. Taniguchi, Y. Komiyama, Y. Fujimura, Y. Ikeda et S. Fukuhara. « High shear stress can initiate both platelet aggregation and shedding of procoagulant containing microparticles ». Blood 88, n^o 9 (1 novembre 1996) : 3456–64. http://dx.doi.org/10.1182/blood.v88.9.3456.bloodjournal8893456.

Texte intégral

Résumé :

Previous studies have demonstrated that a high level of shear stress can produce platelet aggregation without the addition of any agonist. We investigated whether high shear stress could cause both platelet aggregation and shedding of microparticles from the platelet plasma membrane. A coneplate viscometer was used to apply shear stress and microparticle formation was measured by flow cytometry. It was found that microparticle formation increased as the duration of shear stress increased. Both microparticles and the remnant platelets showed the exposure of procoagulant activity on their surfaces. Investigation of the mechanisms involved in shear-dependent microparticle generation showed that binding of von Willebrand factor (vWF) to platelet glycoprotein lb, influx of extracellular calcium, and activation of platelet calpain were required to generate microparticles under high shear stress conditions. Activation of protein kinase C (PKC) promoted shear-dependent microparticle formation. Epinephrine did not influence microparticle formation, although it enhanced platelet aggregation by high shear stress. These findings suggest the possibility that local generation of microparticles in atherosclerotic arteries, the site that pathologically high shear stress could occur, may contribute to arterial thrombosis by providing and expanding a catalytic surface for the coagulation cascade.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Wathne, K. O., B. Carlander, K. R. Norum et R. Blomhoff. « Uptake of retinyl ester in HL-60 cells via the low-density-lipoprotein-receptor pathway ». Biochemical Journal 257, n^o 1 (1 janvier 1989) : 239–44. http://dx.doi.org/10.1042/bj2570239.

Texte intégral

Résumé :

Newly absorbed retinol is transported in association with chylomicrons and their remnants. In addition, after intake of high doses of retinol, significant amounts are also found in low-density lipoprotein (LDL). As both chylomicron remnants and LDL may be taken up by cells via the LDL receptor, and retinoids inhibit proliferation of some leukaemic cells, we have studied the uptake of retinol in leukaemic cells via the LDL-receptor pathway. HL-60 cells contain saturable binding sites for LDL. The binding of LDL to its receptor has a dissociation constant of about 3.2 x 10(-9) M, and the number of receptors per cell was calculated to be about 2700. Uptake of 125I-LDL by HL-60 cells was increased 2-fold by preincubating the cells with mevinolin. The presence of specific receptors for LDL on HL-60 cells was further confirmed by the finding that exogenous LDL cholesterol was able to up-regulate the ACAT (acyl-CoA: cholesterol acyltransferase) activity of HL-60 cells. We then tested the uptake of retinyl ester in leukaemic cells via the LDL-receptor pathway. HL-60 cells were incubated with LDL or chylomicron remnants labelled with [3H]retinyl palmitate. Uptake of retinyl ester associated with both LDL and chylomicron remnants was observed. Furthermore, the presence of excess LDL decreased the uptake by 75-100%, supporting the hypothesis that the uptake of retinyl ester occurred via the LDL receptor in HL-60 cells.

Styles APA, Harvard, Vancouver, ISO, etc.

25

ZIERE, Gijsbertus J., J. Kar KRUIJT, Martin K. BIJSTERBOSCH et Theo J. C. van BERKEL. « Recognition of lactoferrin and aminopeptidase M-modified lactoferrin by the liver : involvement of proteoglycans and the remnant receptor ». Biochemical Journal 313, n^o 1 (1 janvier 1996) : 289–95. http://dx.doi.org/10.1042/bj3130289.

Texte intégral

Résumé :

1. Lactoferrin and aminopeptidase M-modified lactoferrin (APM-lactoferrin; which lacks its 14 N-terminal amino acids) inhibit the liver uptake of lipoprotein remnants. In the present study, the role of proteoglycans in the initial interaction of β-migrating very-low-density lipoprotein (β-VLDL), native and APM-lactoferrin with isolated rat parenchymal liver cells was investigated. Treatment of the cells with chondroitinase lowered the Kd of lactoferrin binding (from 10 to 2.4 μM), and the number of sites/cell (from 20×106 to 7×106), while heparinase treatment did not affect the binding. The binding characteristics of APM-lactoferrin and β-VLDL were not altered by treatment of the cells with chondroitinase or heparinase. It is concluded that proteoglycans are not involved in the initial binding of APM-lactoferrin and β-VLDL to parenchymal cells, while chondroitin sulphate proteoglycans are mainly responsible for the massive, low-affinity binding of native lactoferrin. 2. The binding of lactoferrin, APM-lactoferrin and β-VLDL to parenchymal liver cells was not influenced by the glutathione S-transferase-receptor-associated protein (GST-RAP) (97.2±4.0%, 95.5±3.7% and 98.5% of the control binding), while the binding of α2-macroglobulin was fully blocked at 10 μg/ml GST-RAP (1.8±0.5% of the control binding). Since GST-RAP blocks the binding of all the known ligands to the low-density lipoprotein (LDL)-receptor-related protein (LRP), it is concluded that LRP is not the initial primary recognition site for lactoferrin, APM-lactoferrin and β-VLDL on parenchymal liver cells. 3. We showed earlier that APM-lactoferrin, as compared with lactoferrin, is a more effective inhibitor of the liver uptake of lipoprotein remnants (49.4±4.0% versus 80.8±4.8% of the control at 500 μg/ml respectively). We found in the present study that β-VLDL is able to inhibit the binding of APM-lactoferrin to parenchymal liver cells significantly (74.9±3.3% of the control; P < 0.002), while the lactoferrin binding was unaffected. It is concluded that a still unidentified specific recognition site (the putative remnant receptor) is responsible for the initial binding of remnants to parenchymal cells and it is suggested that the partial cross-competition between APM-lactoferrin and β-VLDL may be of further help in the elucidation of the molecular nature of this recognition site.

Styles APA, Harvard, Vancouver, ISO, etc.

26

CHANG, Suyi, Nobuyo MAEDA et Jayme BORENSZTAJN. « The role of lipoprotein lipase and apoprotein E in the recognition of chylomicrons and chylomicron remnants by cultured isolated mouse hepatocytes ». Biochemical Journal 318, n^o 1 (15 août 1996) : 29–34. http://dx.doi.org/10.1042/bj3180029.

Texte intégral

Résumé :

Lipoprotein lipase (LPL) has been proposed to play a role in the uptake of chylomicron remnants by hepatocytes by mediating the binding of these lipoproteins to cell-surface glycosaminoglycans and to the low-density-lipoprotein receptor-related protein (LRP). This proposal is based on studies that examined the binding of chylomicrons to HepG2 cells, fibroblasts and Chinese hamster ovary cells in culture, in the presence of large amounts of LPL [Beisiegel (1995) Curr. Opin. Lipidol. 6, 117–122]. We have investigated whether LPL attached to the surface of chylomicrons enhances the binding and uptake of these lipoproteins to isolated hepatocytes maintained in culture. Bovine milk LPL was bound to mouse chylomicrons, double-labelled in vivo with [3H]retinol (in retinyl esters) and with [14C]palmitic acid (in triacylglycerols), collected from the mesenteric lymph of normal mice and from mice lacking the apoprotein E (apo E) gene. Normal chylomicrons (containing apo E) and apo E-free chylomicrons, with or without bound LPL, were incubated with cultured hepatocytes isolated from mice lacking the apo E gene. At 0 °C LPL did not enhance the binding of the normal or apo E-free chylomicrons by the hepatocytes. When incubations were performed at 37 °C the triacylglycerols of normal and apo E-free chylomicrons were hydrolysed by LPL and there was a significant uptake of [14C]fatty acids and [3H]retinol by the hepatocytes. The addition of heparin or lactoferrin, a known inhibitor of hepatic uptake of chylomicron remnants, to the incubation medium inhibited the uptake of [3H]retinol, present in the lipoprotein core, but not the uptake of the [14C]fatty acids. We conclude that: (1) LPL attached to chylomicrons in amounts sufficient to effectively hydrolyse their core triacylglycerols does not enhance the binding of these lipoproteins to the surface of isolated hepatocytes; (2) the recognition and uptake of chylomicrons by hepatocytes requires that these lipoproteins be first hydrolysed by LPL; and (3) the uptake of lipolysed chylomicrons (remnants) by hepatocytes does not require the mediation of apo E.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Oakley, R. A., C. J. Lasky, C. A. Erickson et K. W. Tosney. « Glycoconjugates mark a transient barrier to neural crest migration in the chicken embryo ». Development 120, n^o 1 (1 janvier 1994) : 103–14. http://dx.doi.org/10.1242/dev.120.1.103.

Texte intégral

Résumé :

We report that two molecular markers correlate with a transient inhibition of neural crest cell entry into the dorsolateral path between the ectoderm and the somite in the avian embryo. During the period when neural crest cells are excluded from the dorsolateral path, both peanut agglutinin lectin (PNA)-binding activity and chondroitin-6-sulfate (C6S) immunoreactivity are expressed within this path. Both markers decline as neural crest cells enter. Moreover, both markers are absent after an experimental manipulation that accelerates neural crest entry into this path. Specifically, dermamyotome deletions abolish expression of both markers and allow neural crest cells to enter the dorsolateral path precociously. After partial deletions, dermatome remnants remain. These remnants retain PNA and C6S labeling and impede migration locally. Local glycoconjugate expression thus correlates directly with avoidance responses. Since both PNA-binding activity and C6S expression also typify inhibitory somitic tissues, molecules indicated by these markers (or co-regulated molecules) are likely to inhibit both neural crest and axon advance.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Barnard, Graham F., Sandra K. Erickson, Yasuo Nagata et Allen D. Cooper. « Reduced binding and removal of chylomicron remnants by ethionine-induced premalignant liver ». Hepatology 9, n^o 5 (mai 1989) : 731–39. http://dx.doi.org/10.1002/hep.1840090513.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

29

Weiss, J. « Bactericidal/permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP) : structure, function and regulation in host defence against Gram-negative bacteria ». Biochemical Society Transactions 31, n^o 4 (1 août 2003) : 785–90. http://dx.doi.org/10.1042/bst0310785.

Texte intégral

Résumé :

Lipopolysaccharide-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI) are closely related endotoxin-binding proteins that function in a co-ordinated manner to facilitate an integrated host response to invading Gram-negative bacteria. Differences in the structure and function of BPI and LBP, as well as differences in their mobilization, permit highly sensitive pro-inflammatory responses to small numbers of bacteria at the onset of bacterial invasion and, later, efficient elimination of viable bacteria and their remnants and of endotoxin-driven inflammation.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Thabit, Budoor Mohammed, et Hanisa Hassan. « STUDY ON USAGE OF FABRIC REMNANTS ON YEMENI’S FASHION FOR WOMEN ». International Journal of Heritage, Art and Multimedia 3, n^o 9 (10 juin 2020) : 01–10. http://dx.doi.org/10.35631/ijham.39001.

Texte intégral

Résumé :

The big quantity of fabric remnants was thrown away in Yemen due to a lack of knowledge and competency in reusing the remnants as material for making clothes. It has become a burden to the consumers and also bad for the environment. Therefore, this research aims to understand why the seamstress in Yemen wasted a lot of remnants and the possibility of using the remnants in making innovative designs on Yemenis traditional clothing such as Abaya and Galabiah. In order to answer the objectives, the researcher applies the qualitative approach in order to describe and understand the problems stated for this study by made several interviews with Yemeni’s respondent who used to be a seamstress in Yemen, besides her personal experience when working in the workshop in Yemen. The prior objective is to recognise what was done to remnants in sewing workshops. Secondly, the researcher will be producing a design line using remnants with various techniques of embellishment to create new designs for Yemen's traditional costume of Abaya and Galabiah. The researcher hopes that through her innovation can inspire other designers or seamstress to use remnants as a source of material in making clothes. At the end of this study, the researcher found out that her Yemeni’s respondents threw away remnants because they do not have the knowledge and skill to turn remnants into fashion. Plus, they are also lazy to think of recycling remnants since they had lots of orders from clients. In the end, the researcher made a questionnaire about the final designs and they did agree that remnants can be used to make beautiful traditional Yemeni’s dress. Since remnants came from different sources, the design made is unique and one-off, which is the preference for most Yemenis. The researcher also proved that innovative and creative thinking are vital in creating designs, and hopefully it can change the perspective of Yemeni women towards the usage of remnants in fashion.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Maddox-Hyttel, Poul, Bolette Bjerregaard et Jozef Laurincik. « Meiosis and embryo technology : renaissance of the nucleolus ». Reproduction, Fertility and Development 17, n^o 2 (2005) : 3. http://dx.doi.org/10.1071/rd04108.

Texte intégral

Résumé :

The nucleolus is the site of rRNA and ribosome production. This organelle presents an active fibrillogranular ultrastructure in the oocyte during the growth of the gamete but, at the end of the growth phase, the nucleolus is transformed into an inactive remnant that is dissolved when meiosis is resumed at germinal vesicle breakdown. Upon meiosis, structures resembling the nucleolar remnant, now referred to as nucleolus precursor bodies (NPBs), are established in the pronuclei. These entities harbour the development of fibrillogranular nucleoli and re-establishment of nucleolar function in conjunction with the major activation of the embryonic genome. This so-called nucleologenesis occurs at a species-specific time of development and can be classified into two different models: one where nucleolus development occurs inside the NPBs (e.g. cattle) and one where the nucleolus is formed on the surface of the NPBs (e.g. pigs). A panel of nucleolar proteins with functions during rDNA transcription (topoisomerase I, RNA polymerase I and upstream binding factor) and early (fibrillarin) or late rRNA processing (nucleolin and nucleophosmin) are localised to specific compartments of the oocyte nucleolus and those engaged in late processing are, to some degree, re-used for nucleologenesis in the embryo, whereas the others require de novo embryonic transcription in order to be allocated to the developing nucleolus. In the oocyte, inactivation of the nucleolus coincides with the acquisition of full meiotic competence, a parameter that may be of importance in relation to in vitro oocyte maturation. In embryo, nucleologenesis may be affected by technological manipulations: in vitro embryo production apparently has no impact on this process in cattle, whereas in the pig this technology results in impaired nucleologenesis. In cattle, reconstruction of embryos by nuclear transfer results in profound disturbances in nucleologenesis. In conclusion, the nucleolus is an organelle of great importance for the developmental competence of oocytes and embryos and may serve as a morphological marker for the completion of oocyte growth and normality of activation of the embryonic genome.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Kluiving, S. J., A. L. L. M. Verbers et W. J. F. Thijs. « Lithological analysis of 45 presumed pingo remnants in the northern Netherlands (Friesland) : substrate control and fill sequences ». Netherlands Journal of Geosciences - Geologie en Mijnbouw 89, n^o 1 (juillet 2010) : 61–75. http://dx.doi.org/10.1017/s0016774600000822.

Texte intégral

Résumé :

AbstractA number of 45 presumed pingo remnants have been analysed on lithological criteria while measured parameters of pingo remnants can be compared on a spatial scale. Methods used were hand augering and radiocarbon dating. Out of 45 cored sites thirty sites proved to represent pingo remnants after having tested the results according to the set of descriptive criteria. Does a difference in filling types in a spatial analysis influence the choice of early settlers in this region? Results show that two groups of pingo remnants can be distinguished by the nature of the pingo filling. Type 1 pingo remnants with predominantly peat filling are found in the lower valleys between the higher glacial till ridges. Type 2 pingo remnants with equal loam and peat filling are predominantly found on the higher glacial till ridges. Type 2 pingo remnants generally have a greater depth, are more ellipsoid in shape, and have a steeper slope angle than type 1 pingo remnants on the lower terrain. Results indicate that the substrate character influenced the development of infilling of pingo remnants. Marshy environments may have existed for a prolonged period throughout the Holocene in pingo remnants on the glacial ridges, while pingo remnants on the lower terrain are filled in by peat bogs. Landscape evolution based on the results of a distinct dataset of pingo remnants can help to solve archaeological problems of settlement issues when combined with new palaeobotanic data and high resolution dates.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Ham, Youngjun, et Miran Han. « Evaluation of Shear Bond Strength of Various Orthodontic Bracket Bonding Agents ». JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY 49, n^o 3 (31 août 2022) : 264–73. http://dx.doi.org/10.5933/jkapd.2022.49.3.264.

Texte intégral

Résumé :

Due to the development of properties of adhesive materials currently used in dentistry, the bonding ability between the brackets and the tooth enamel has been greatly improved. In general, in situations where cooperation can be obtained, adhesion of the orthodontic bracket through the conventional three-step process can show excellent bonding strength. However, if it is difficult to expect patient cooperation, as in the pediatric dentistry area, or if moisture isolation is not properly performed, the binding strength that does not reach the expected effect. As a result, various products that simplify the process for adhesion are being developed. The aim of this study was to evaluate and compare the shear bonding strength between the conventional 3-step adhesion system, self-etching primer system and one-step adhesion system that reduces the priming process. A total of 60 human maxillary, mandibular premolars were prepared. Group I (control group) were followed conventional 3-step bonding process. Group II were conditioned with self-etching primer. Group III were etched with 37% phosphoric acid and brackets were bonded with self-priming adhesive. The resultant shear bond strength of each group was measured and an adhesive remnant index (ARI) was recorded. The mean shear bond strength of group I, II, III were 14.69 MPa, 11.21 MPa and 12.21 MPa respectively. Significant differences could only be found between group I, II and group I, III (p < 0.05). The ARI indicated no significant difference among all groups.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Chen, Bo, et Hong Yang. « Observation of hyaloid artery remnants in premature infants ». International Eye Research 2, n^o 4 (28 décembre 2021) : 206–9. http://dx.doi.org/10.18240/ier.2021.04.05.

Texte intégral

Résumé :

AIM: To observe the hyaloid artery remnants in the eyes of premature infants. METHODS: This retrospective study recruited premature infants who consecutively attended the Tongji Hospital for retinopathy of prematurity screening from May 2018 to November 2018. The binocular indirect ophthalmoscope was used for examination. RESULTS: In total, 60 cases were pulled for data analysis. The cases were categorized as having the following condition: hyaloid artery remnants positive or hyaloid artery remnants negative. It was showed that the remnants positive group had significant lower gestational age and birth weight than those of the negative group (P<0.05). There was no significant difference in gender, labor presentation and retinopathy of prematurity between the two groups (P>0.05). The hyaloid artery remnants completely regressed in all the follow-up cases. The range of disappearing time of hyaloid artery remnants was 37-44wk of corrected gestational age. CONCLUSION: The hyaloid artery remnants in preterm infants are most likely to be physiological residues. Younger or lower weight premature infants will have higher positive detection rates of hyaloid artery remnants. It seems like co-existence with retinopathy of prematurity (ROP) has no significant association with the detection of hyaloid artery remnants. When the corrected gestational age extends over 43wk, if the hyaloid artery remnants don’t regress, there is a possibility of pathological changes, and appropriate interventions should be selected according to the severity of the lesions.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Dwek, Eli. « Infrared Analysis of Supernova Remnants ». International Astronomical Union Colloquium 101 (1988) : 363–78. http://dx.doi.org/10.1017/s0252921100102672.

Texte intégral

Résumé :

AbstractInfrared observations of supernova remnants obtained with the Infrared Astronomical Satellite provide new insights into the dynamics and energetics of the remnants, and into their interaction with the ambient interstellar medium. In most remnants the infrared emission arises from dust that is collisionally heated by the X-ray emitting gas. The infrared observations can therefore be used as a diagnostic for the physical conditions of the shocked gas. In particular, it is shown that all the prominent X-ray remnants in the Galaxy and in the LMC cool mainly by dust grain collisions instead of atomic processes.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Gerganov, Venelin Miloslavov, Amir Samii, Arasch Akbarian, Lennart Stieglitz, Madjid Samii et Rudolf Fahlbusch. « Reliability of intraoperative high-resolution 2D ultrasound as an alternative to high–field strength MR imaging for tumor resection control : a prospective comparative study ». Journal of Neurosurgery 111, n^o 3 (septembre 2009) : 512–19. http://dx.doi.org/10.3171/2009.2.jns08535.

Texte intégral

Résumé :

Object Ultrasound may be a reliable but simpler alternative to intraoperative MR imaging (iMR imaging) for tumor resection control. However, its reliability in the detection of tumor remnants has not been definitely proven. The aim of the study was to compare high-field iMR imaging (1.5 T) and high-resolution 2D ultrasound in terms of tumor resection control. Methods A prospective comparative study of 26 consecutive patients was performed. The following parameters were compared: the existence of tumor remnants after presumed radical removal and the quality of the images. Tumor remnants were categorized as: detectable with both imaging modalities or visible only with 1 modality. Results Tumor remnants were detected in 21 cases (80.8%) with iMR imaging. All large remnants were demonstrated with both modalities, and their image quality was good. Two-dimensional ultrasound was not as effective in detecting remnants < 1 cm. Two remnants detected with iMR imaging were missed by ultrasound. In 2 cases suspicious signals visible only on ultrasound images were misinterpreted as remnants but turned out to be a blood clot and peritumoral parenchyma. The average time for acquisition of an ultrasound image was 2 minutes, whereas that for an iMR image was ~ 10 minutes. Neither modality resulted in any procedure-related complications or morbidity. Conclusions Intraoperative MR imaging is more precise in detecting small tumor remnants than 2D ultrasound. Nevertheless, the latter may be used as a less expensive and less time-consuming alternative that provides almost real-time feedback information. Its accuracy is highest in case of more confined, deeply located remnants. In cases of more superficially located remnants, its role is more limited.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Barry, Orla, et Garret FitzGerald. « Mechanisms of Cellular Activation by Platelet Microparticles ». Thrombosis and Haemostasis 82, n^o 08 (1999) : 794–800. http://dx.doi.org/10.1055/s-0037-1615913.

Texte intégral

Résumé :

IntroductionEukaryotic cells, after activation, shed components of their plasma membranes into the extracellular space.1,2 Such fragments may include cytoplasmic elements and are known colloquially as microparticles (MPs). Monocytes,3 lymphocytes,4 endothelial cells,5 erythrocytes,6 and granulocytes7 have been shown to vesiculate either in vitro or in vivo. MPs from other sources have also been reported to exist in vivo.8,9 In addition, platelets have been found to vesiculate following activation by agonists.10,11 Platelets activated with collagen and/or thrombin, by the Ca2+ ionophore A23187 or the complement protein C5b-9, induce platelet microparticle (PMP) formation. While the effect of these agonists is to increase platelet cytosolic Ca2+ concentration, it has been suggested that calpain activation,12-14 cytoskeletal reorganization,12,14,15 protein phosphorylation14 and phospholipid translocation16,17 also may have roles in PMP formation.Shear stress has been shown to induce platelet vesiculation. The mechanisms involved include the binding of von Willebrand factor (vWF) to either glycoprotein (GP)-Ib or GP IIb/IIIa.18 These in vitro observations are supported by an ex vivo model of high arterial shear stress. High shear stress, as pertains in the atherosclerotic vasculature, was shown to activate platelets and trigger PMP formation. Meanwhile, under physiological or simulated shear stress conditions in arteries with a minor degree of stenosis, no vesiculation occurred.19 Platelet microparticles contain surface receptors for both factor VIII, a cofactor in the tenase enzyme complex,20 and factor Va (which assembles with factor Xa to form the prothrombinase complex).10 While a transient expression of platelet membrane factor VIII binding has been reported, more stable factor VIII and factor Va has been reported for PMPs.20 High- and low-affinity binding sites for activated factor IX are also present on PMPs.21 Thus, PMPs have the potential to provide procoagulant activity at a distance from the site of platelet activation and for a longer period than activated platelets. Also, PMPs possess anticoagulant properties.22 These PMPs can bind protein S, an anticoagulant plasma protein responsible for degradation of the phospholipid-bound coagulation factor Va and factor VIII and which supports the binding of both protein C and activated protein C (APC). Coupled to the same platelet stimulation reactions, PMPs possess both pro- and anticoagulant properties. The relative distribution of pro- and anticoagulant activity between platelets and PMP remains approximately the same, irrespective of the agonist used, with approximately 25% of both activities associated with PMP. Furthermore, a recent study reported that protein C inhibitor, a member of the serpin family secreted from activated platelets, binds preferentially to the phosphatidylethanolamine (PE) of platelet membranes and PMPs, and efficiently inhibits phospholipid-bound APC.23 Similar to PMPs, MPs released from monocytes, lymphocytes, erythrocytes, and granulocytes demonstrate procoagulant activity, but whether they display anti-coagulant activity remains to be shown. The density of aminophospholipids also has been shown to be greater on PMPs than on remnant platelets.24,25 This may account for the preferential binding to PMPs over platelets of factor VIII,20 factor Va,10 and factor IXa.21 The PMP surface may provide the optimal phosphatidylserine (PS) level required by the binding sites of these blood clotting factors. Preferential binding of these critical factors favor the participation of PMPs in hemostatic protection and may explain the lack of bleeding symptoms in patients with autoimmune thrombocytopenia associated with high levels of PMPs.26 Elevated levels of PMPs in vivo have been reported for patients with activated coagulation and fibrinolysis,27 unstable angina,28 diabetes mellitus,29 sickle cell anemia,30 and human immunodeficiency virus (HIV).31 Recently, it was demonstrated for the first time that PMPs generated in vivo can stimulate coagulation.32 Procoagulant PMPs generated during coronary bypass surgery, especially in pericardial blood, supported coagulation via a tissue factor (TF)/ factor VII-dependent and factor XII-independent pathway.The functional importance of PMPs in human disease has not been well-defined. This is despite their pro- and anticoagulative properties10,16,20,22 and the convincing evidence that the PMP surface possesses the platelet—endothelium attachment receptors, glycoprotein GP IIb/IIIa, Ib, and IaIIa33-35 and P-selectin.34 Despite the association of PMPs with a range of clinical abnormalities,26-31,36 it remains unsolved whether persistent platelet activation, with concomitant formation of PMPs, is merely a consequence of the disease or reflects the influence of previously formed PMPs in the circulation.PMPs have become a popular focus of research, for both clinical and basic investigation. Recently, the possibility that MPs might, themselves, evoke cellular responses in the immediate microenvironment of their formation has been suggested. For example, endothelial cell activation by thrombin results in vesicle shedding, which, in turn, activates neutrophils and enhances their propensity to adhere to endothelial cells.37 Similarly, MPs shed from platelets activated with Staphylococcus aureus α-toxin induce platelet aggregation.38 The role of PMPs in modulating their local environment is the subject of this review. An overview of the mechanism(s) of cellular activation by PMPs will be provided. PMP-induced activation of platelets, human umbilical vein endothelial cells (HUVECs), monocytes, and U-937 (human promonocytic leukemia) cells have been used as models for assessing the possible biological effects of PMPs in vivo.

Styles APA, Harvard, Vancouver, ISO, etc.

38

ELSEGOOD, Caryn L., Sebely PAL, Paul D. ROACH et John C. L. MAMO. « Binding and uptake of chylomicron remnants by primary and THP-1 human monocyte-derived macrophages : determination of binding proteins ». Clinical Science 101, n^o 2 (1 août 2001) : 111. http://dx.doi.org/10.1042/cs20010057.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

39

Fortin, Daniel, et Graham W. Arnold. « The Influence of Road Verges on the Use of Nearby Small Shrubland Remnants by Birds in the Central Wheatbelt of Western Australia ». Wildlife Research 24, n^o 6 (1997) : 679. http://dx.doi.org/10.1071/wr96081.

Texte intégral

Résumé :

In the Kellerberrin District of the Western Australian wheatbelt, about 60% of the remnants of native vegetation are smaller than 10 ha. We studied the variation in bird abundance in 13 small remnants (range 0·03–6·71 ha) of shrubland isolated in farmland by distances of 70–600 m from the nearest native vegetation, a road verge. Overall, 31 species were recorded in the remnants and nearby road verges, and species richness varied from 7 to 15 at individual sites. Regression analysis showed that the structural attributes of verges and the number of birds found in verges were more often significant predictors of variation in the number of individuals of the most common 19 species censused in remnants than were the structural attributes in the remnants themselves. The diversity of all bird species and the richness of species dependent on native vegetation decreased significantly with the distance of remnants from road verges. For a group of 10 species of small passerines, species richness, species turnover, and variation in the number of individuals between consecutive censuses all were negatively related to the distance between remnants and road verges. For five of these 10 species, there were fewer individuals in remnants than in adjacent road verges when the distance between them exceeded 110 m. However, for less-isolated remnants (≤110 m), only one species showed a significant difference in abundance. It is concluded that these small shrubland remnants are primarily used by birds moving to and from adjacent areas of native vegetation, in this case road verges. The value of small remnants of vegetation as parts of the conservation network decreases with their isolation, and is strongly linked to the use of road verges by the shrubland bird community.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Spinelli, Andrea, Fausto Zamparini, Alessio Buonavoglia, Paolo Pisi, Maria Giovanna Gandolfi et Carlo Prati. « Reciprocating System for Secondary Root Canal Treatment of Oval Canals : CBCT, X-rays for Remnant Detection and Their Identification with ESEM and EDX ». Applied Sciences 12, n^o 22 (17 novembre 2022) : 11671. http://dx.doi.org/10.3390/app122211671.

Texte intégral

Résumé :

Aim of the study: to evaluate root filling remnants after secondary root canal treatments (SRCTs) of oval-shaped canals with X-rays and cone beam computed tomography (CBCT). The SRCTs were performed using reciprocating NiTi instruments. Methods: Single-rooted teeth (N = 64) were randomly treated with Reciproc Blue (RB) and filled with AH Plus/single cone (SC group) or AH Plus/Guttafusion (GF group). After seven days of storage in HBSS (Hanks balanced salt solution), Gates Glidden burs #2/3 and RB #25 and #40 were used for the SRCTs. The time to complete the procedure was measured. X-rays and CBCT were used to calculate, respectively, the area and the volume occupied by the remnants in the coronal, middle, and apical thirds of each canal. Environmental scanning electron microscopy (ESEM) and energy dispersive X-ray spectroscopy (EDX) were used for qualitative evaluation and morphology composition of the remnants in sectioned roots. A statistical analysis was performed using Sigma Plot (version 13, IBM, Armonk, NY, USA). The study was designed according to PRILE guidelines. Results: After the SRCTs, the middle thirds of the root canals showed the presence of remnants in both groups, as demonstrated by X-rays and CBCT. The GF group showed a statistically significant higher volume of remnants than the SC Group only in the middle third. The ESEM supported by the EDX revealed the remnant composition by the detection of trace elements of sealer and gutta-percha in all root canals. Conclusion: The study demonstrated that the middle third of root canals is a critical region where remnants were packed and spread in the buccal-lingual sides of canals. ESEM-EDX detected a fine layer of filling remnants in all root thirds, suggesting a larger canal contamination than the X-rays and CBCT examinations revealed.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Milne, D. K., J. L. Caswell, R. F. Haynes, M. J. Kesteven, K. J. Wellington, R. S. Roger et J. D. Bunton. « Synthesis Observations of Southern Supernova Remnants ». Publications of the Astronomical Society of Australia 6, n^o 1 (1985) : 78–89. http://dx.doi.org/10.1017/s1323358000026734.

Texte intégral

Résumé :

AbstractThe synthesis telescopes at Fleurs and Molonglo have been used to map 50 supernova remnants. Additional specialized software to process the maps has been developed, and Parkes observations have been used to supply short spacing information missing from the maps.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Nurden, Paquita, Alan T. Nurden, Jean-Max Pasquet, Jocelyne Enouf, Cécile Faurie-Bonnafous, Sylvia La Marca, Margherita Punzo, Luciano Baronciani et Augusto B. Federici. « Morphological Changes of Platelets from Patients with Von Willebrand Disease Types 2B and 3 Suggest That Von Willebrand Factor Intervenes in Platelet Formation from Megakaryocytes. » Blood 112, n^o 11 (16 novembre 2008) : 1238. http://dx.doi.org/10.1182/blood.v112.11.1238.1238.

Texte intégral

Résumé :

Abstract The interaction between von Willebrand factor (VWF) and platelets plays a key role in hemostasis. VWF gene abnormalities result in the most common inherited bleeding disorder, von Willebrand disease (VWD). VWD2B, characterized by gain-of-function binding of VWF to platelet glycoprotein (GP)Ib, is due to mutations located within a portion of exon 28 of the VWF gene, coding for the VWFA1 domain. We have previously shown in a family with a R1308P mutation that the enhanced interaction between VWF and GPIb can also occur in the bone marrow leading to a premature release of platelets from megakaryocytes (MKs) with circulating large platelets and agglutinates (Nurden et al, Blood 2006). We have now widened our study to see if these changes are common in VWD2B. As a control, we also included platelets from patients lacking VWF. In total, we have analyzed the platelets from 9 VWD2B patients with the following mutations: P1266L, R1306W, R1308C, I1309V, V1316M, R1341Q, R1341W; platelets from 2 VWD3 patients with a large deletion of the VWF gene were also included. We have used electron microscopy (EM) and immunofluorescence (IF) to evaluate platelet morphological characteristics; included in the morphometric studies was the measure of platelet size. We have also analyzed platelet VWF content and performed plasma/platelet VWF multimeric analyses. PMCA4B belonging to the SERCA proteins (a substrate of caspase) and GRP78 a stress protein were evaluated as markers of abnormal megakaryocytopoiesis. At the time of blood withdrawal, 4 patients were thrombocytopenic; nevertheless, for all patients with VWD2B a pool of giant platelets was found. Agglutinates were often but not always present. Globally, the percentage of platelets with the longest diameter (LD) > than 3μm was 58 ±16% (controls 24 ± 13%) and the shortest diameter (SD) > 2μm was 33% ± 13 (controls 4 ± 0.6%). Thus platelets were enlarged without being round. The largest platelets were found for the patient with the V1316M mutation. The content of alpha granules appeared normal, as was the quantity of internal membrane pools. To our surprise, giant platelets were also present for the two VWD3 patients; 66 and 57% of the platelets have a LD > 3μm and 21 and 19% a SD > than 2μm. The EM evaluation for both type 3 patients suggested that some giant platelets resembled large fragments prematurely detached from MKs. Examining further by IF and EM coupled with immunogold labelling with a mixture of anti-GPIIb-IIIa and GPIb-IX MoAbs revealed occasional circulating MKs. Nuclei surrounded by cytoplasmic remnants were also seen. Analysis of PMCA4B and GRP 78, showed that their levels were increased for VWD2B patients with the R1341Q mutation but borderline for the patient with the R1308C mutation (contrasting with increased levels for R1308P) showing that premature apoptosis was not a constant feature. These results were normal for the VWD3 patients. Our results confirm that megakaryocytopoiesis can be affected by both an abnormal gain-of-function (VWD2B) and completely deficient (VWD3) VWF. However, the consequences of up-regulated VWF and VWF deficiency may be different.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Pedlar, Alan. « Extragalactic Supernovae and the Starformation Rate ». Symposium - International Astronomical Union 205 (2001) : 366–73. http://dx.doi.org/10.1017/s0074180900221487.

Texte intégral

Résumé :

The advantages of studying samples of supernova remnants in external galaxies will be discussed. A summary of how the remnants can be used to infer starformation rates in starburst galaxies will be given, as will the use of these remnants to probe the interstellar medium of these galaxies on parsec scales. Widefield EVN and Global VLBI measurements of remnants in the nearby starburst in M82 will be described in detail, and recent expansion velocity measurements described. The similarity between the strongest compact source in M82 and the objects recently discovered in Arp220 will be noted. The sensitivity limitations of this work will be discussed and the prospects for studies of more distant objects using Square Kilometer Array considered.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Fakhry Attalla et al., Raky. « Investigation of Pineapple Remnants Used in Fish Aqua Feeds ». Egyptian Journal of Aquatic Biology and Fisheries 26, n^o 1 (1 janvier 2022) : 1–22. http://dx.doi.org/10.21608/ejabf.2022.213363.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

45

Alele, Jimmy, Jing Jiang, Jeffrey F. Goldsmith, Xiaoyong Yang, Hiralal G. Maheshwari, Roy A. Black, Gerhard Baumann et Stuart J. Frank. « Blockade of Growth Hormone Receptor Shedding by a Metalloprotease Inhibitor* ». Endocrinology 139, n^o 4 (1 avril 1998) : 1927–35. http://dx.doi.org/10.1210/endo.139.4.5906.

Texte intégral

Résumé :

Abstract GH, an important growth-promoting and metabolic hormone, exerts its biological effects by interacting with cell surface GH receptors (GHRs). The GHR is a single membrane-spanning protein that binds GH via its extracellular domain. The high affinity GH-binding protein (GHBP), which corresponds to a soluble form of the GHR extracellular domain, carries a substantial fraction of the GH in the circulation of various species and probably has a role in modulation of the hormone’s bioavailability. Although in rodents, it is believed that the GHBP is largely derived by translation of an alternatively spliced GHR messenger RNA, in humans and rabbits, proteolytic cleavage of the membrane-anchored receptor releases the GHR extracellular domain, which is believed to thereby become the GHBP. In this study, we used human IM-9 lymphocytes and GHR antibodies to study this proteolytic shedding of the GHBP. As determined by immunoblotting with anti-GHR cytoplasmic domain serum, addition of phorbol 12-myristate 13-acetate (PMA; 1μ g/ml) to serum-starved cells led to rapid loss (roughly 60% decline after 1 h; t1/2 = ∼5 min) of mature GHRs (115–140 kDa) from either total cell or detergent-soluble extracts. Loss of full-length GHRs was accompanied by accumulation of four proteins (65–68 kDa), each reactive with the cytoplasmically directed antiserum. The pattern of appearance of these GHR ctyoplasmic domain proteins, the electrophoretic and immunological characteristics of which are similar to those of a recombinant rabbit GHR mutant that lacks the extracellular domain, was such that progressively faster migrating forms were evident between 5–60 min of PMA exposure. Treatment with N-ethylmaleimide (NEM; 5 mm), an agent known to cause GHBP shedding from IM-9 cells, promoted a similar rapid loss of full-length GHRs and an accumulation of GHR cytoplasmic domain remnant proteins. PMA-induced, but not NEM-induced, GHR proteolysis was blocked by the protein kinase C inhibitor, GF109203X. Both PMA- and NEM-induced receptor proteolysis were, however, inhibited by the metalloprotease inhibitor, Immunex Compound 3 (minimum effective concentration, 10 μm). Notably, PMA and NEM also promoted shedding of GHBP into the conditioned medium of the cells, as determined by a chromatographic [125I]human GH binding assay; this GHBP shedding was also inhibited by Immunex Compound 3. These results strongly implicate a member(s) of the metalloprotease family as a potential GHBP-generating enzyme.

Styles APA, Harvard, Vancouver, ISO, etc.

46

W. Arnold, G., et J. R. Weeldenburg. « The effects of isolation, habitat fragmentation and degradation by livestock grazing on the use by birds of patches of Gimlet Eucalyptus salubris woodland in the wheatbelt of Western Australia ». Pacific Conservation Biology 4, n^o 2 (1998) : 155. http://dx.doi.org/10.1071/pc980155.

Texte intégral

Résumé :

The numbers of species, and the frequency of occurrence of individual species, in patches of Gimlet Eucalyptus salubris woodland in remnants of native vegetation in the central wheatbelt of Western Australia were recorded over a year. These values were examined in relation to the structural characteristics of the patches and the biogeographic attributes of the remnants (i.e., size and various indices of isolation from other native vegetation). There were five patches in large remnants (>100 ha) and 24 patches in small remnants (0.5?27.0 ha). Most of the small remnants were grazed by livestock and had lost much or all of the shrub understorey. The Galah Cacatua roseicapilla and Port Lincoln Ringnecked Parrot Platycercus zonarius were found in all patches, but the remaining large species of birds (Australian Raven Corvus coronoides,Pied Butcherbird Cracticus nigroregularis, Crested Pigeon Ocyphaps lophotes, and Yellow-throated Miner Manorina flavigula) were found more frequently in patches in small remnants. Conversely, with the exception of the Striated Pardalote Pardalotus striatus, small passerine species were found less frequently in patches in small remnants. Remnant size was significantly negatively correlated with frequency of occurrence of six of the eight common large species, indicating that these species concentrated in patches in small remnants, and significantly positively correlated with frequency of occurrence of two of four small passerine species. Having taken out the effect of remnant area, a stepwise regression procedure was used to see whether other biogeographic attributes of the remnants or habitat structure in the patches influenced the frequency of occurrence of individual species and species richness. As area of native vegetation within a 5 km radius increased so did the frequency of occurrence of the Galah and Port Lincoln Parrot, indicating that local numbers of the species affects their presence. Of the large birds only the Yellowthroated Miner was influenced by patch structural attributes whereas all species of small passerines showed responses to various structural attributes of the patches. Frequency of occurrence of the Striated Pardalote and the number of species of small passerines in a patch decreased with increasing distance to the nearest native vegatation. Overall frequency of occurence of small passerines increased with the number of linear strips of native vegetation linked to a remnant. In this study a majority of the small remnants were too small to support resident birds. The Gimlet patches, if used, would be part of a home range. Loss of the shrub understorey through grazing and loss of canopy cover through tree deaths had a significant impact on numbers of species of small passerines using the Gimlet patches. The conservation value of the patches in small remnants would be enhanced by increasing remnant size and by the linking of remnants to nearby native vegetation.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Jovanović, Nemanja. « Case Remnants in the Bulgarian Phrasemes ». Bulgarski Ezik i Literatura-Bulgarian Language and Literature 63, n^o 5 (9 octobre 2021) : 512–27. http://dx.doi.org/10.53656/bel2021-5-5.cases.fras.

Texte intégral

Résumé :

This article analyzes the case remnants in Bulgarian phrasemes. As a source we used Nov frazeologichen rechnik na balgarskiya ezik (1993) by Keti Ankova-Nicheva. Where possible, a comparison has been made with phrasemes in Russian, Serbian, Old Bulgarian and Church Slavonic, which are taken from phraseological dictionaries of the respective languages. The origin of some case forms has been studied. The methods of deﬁnitional, component and comparative analysis with Slavic synthetic languages are used. The analysis of the material shows that under the influence of the Church Slavonic language, most of the phraseologies that have retained case forms belong to the sphere of religion.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Rocha, CFD, HG Bergallo, M. Van Sluys, MAS Alves et CE Jamel. « The remnants of restinga habitats in the brazilian Atlantic Forest of Rio de Janeiro state, Brazil : habitat loss and risk of disappearance ». Brazilian Journal of Biology 67, n^o 2 (mai 2007) : 263–73. http://dx.doi.org/10.1590/s1519-69842007000200011.

Texte intégral

Résumé :

"Restingas" (herbaceous/shrubby coastal sand-dune habitats) used to cover most of Rio de Janeiro State coast, and have suffered extensive degradation over the last five centuries. Using satellite images and field work, we identified the remaining restingas in the State, recording the factors that might cause their degradation. We used two mosaics of Landsat 7 scenes (spatial resolution 15 and 30 m) to map and evaluate preliminarly the remaining areas and conservation status. Each remnant area was checked in the field, degraded areas within it were mapped and subtracted from the remnants. We identified 21 restinga remnants totalling 105,285 ha. The largest and smallest restinga remnants were Jurubatiba (25,141 ha) and Itaipu (23 ha), respectively. We identified 14 causes of degradation. The most important were vegetation removal for housing developments, establishment of exotic plant species, change of original substrate, and selective removal of species of economic importance for the horticultural industry. All restingas had disturbed parts under strong pressure due to human activities. Due to intense habitat loss, and occurrence of endemic/threatened vertebrate species in restinga habitats, we strongly indicate the implementation of new conservation units to protect these fragile remnants. This habitat is steadily decreasing and most remnants lack legal protection. Therefore, under the current human pressure most of this unique habitat is likely to be lost from the State within the next few years.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Seward, Frederick D. « Neutron Stars in Twelve Supernova Remnants ». Symposium - International Astronomical Union 125 (1987) : 99–108. http://dx.doi.org/10.1017/s0074180900160541.

Texte intégral

Résumé :

X-ray observations of selected SNR are summarized. Five contain internal spinning neutron stars–four isolated and one in a binary system. Another seven contain central unresolved sources or bright nebulae. Observations of these nebulae, probably due to synchrotron emission, are used to estimate characteristics of the unseen pulsars.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Angelo, M. S., J. F. C. Santos, W. J. B. Corradi et F. F. S. Maia. « Investigating dynamical properties of evolved Galactic open clusters ». Astronomy & ; Astrophysics 624 (avril 2019) : A8. http://dx.doi.org/10.1051/0004-6361/201832702.

Texte intégral

Résumé :

Context. The stellar content of Galactic open clusters is gradually depleted during their evolution as a result of internal relaxation and external interactions. The final residues of the long-term evolution of open clusters are called open cluster remnants. These are sparsely populated structures that can barely be distinguished from the field. Aims. We aimed to characterise and compare the dynamical states of a set of 16 objects catalogued as remnants or remnant candidates. We employed parameters that are intimately associated with the dynamical evolution: age, limiting radius, stellar mass, and velocity dispersion. The sample also includes 7 objects that are catalogued as dynamically evolved open clusters for comparison purposes. Methods. We used photometric data from the 2MASS catalogue, proper motions and parallaxes from the Gaia DR2 catalogue, and a decontamination algorithm that was applied to the three-dimensional astrometric space of proper motions and parallaxes (μα, μδ, ϖ) for stars in the objects’ areas. The luminosity and mass functions and total masses for most open cluster remnants are derived here for the first time. Our analysis used predictions of N-body simulations to estimate the initial number of stars of the remnants from their dissolution timescales. Results. The investigated open cluster remnants present masses (M) and velocity dispersions (σv) within well-defined ranges: M between ∼10−40 M⊙ and σv between ∼1−7 km s−1. Some objects in the remnant sample have a limiting radius Rlim ≲ 2 pc, which means that they are more compact than the investigated open clusters; other remnants have Rlim between ∼2−7 pc, which is comparable to the open clusters. We suggest that cluster NGC 2180 (previously classified as an open cluster) is entering a remnant evolutionary stage. In general, our clusters show signals of depletion of low-mass stars. This confirms their dynamically evolved states. Conclusions. We conclude that the open cluster remnants we studied are in fact remnants of initially very populous open clusters (N0 ∼ 103−104 stars). The outcome of the long-term evolution is to bring the final residues of the open clusters to dynamical states that are similar to each other, thus masking out the memory of the initial formation conditions of star clusters.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Binding, remnants used in »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres