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Kang, Yang Jun. "Microfluidic-Based Biosensor for Sequential Measurement of Blood Pressure and RBC Aggregation Over Continuously Varying Blood Flows". Micromachines 10, n.º 9 (30 de agosto de 2019): 577. http://dx.doi.org/10.3390/mi10090577.
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Aggregation of red blood cells (RBCs) varies substantially depending on changes of several factors such as hematocrit, membrane deformability, and plasma proteins. Among these factors, hematocrit has a strong influence on the aggregation of RBCs. Thus, while measuring RBCs aggregation, it is necessary to monitor hematocrit or, additionally, the effect of hematocrit (i.e., blood viscosity or pressure). In this study, the sequential measurement method of pressure and RBC aggregation is proposed by quantifying blood flow (i.e., velocity and image intensity) through a microfluidic device, in which an air-compressed syringe (ACS) is used to control the sample injection. The microfluidic device used is composed of two channels (pressure channel (PC), and blood channel (BC)), an inlet, and an outlet. A single ACS (i.e., air suction = 0.4 mL, blood suction = 0.4 mL, and air compression = 0.3 mL) is employed to supply blood into the microfluidic channel. At an initial time (t < 10 s), the pressure index (PI) is evaluated by analyzing the intensity of microscopy images of blood samples collected inside PC. During blood delivery with ACS, shear rates of blood flows vary continuously over time. After a certain amount of time has elapsed (t > 30 s), two RBC aggregation indices (i.e., SEAI: without information on shear rate, and erythrocyte aggregation index (EAI): with information on shear rate) are quantified by analyzing the image intensity and velocity field of blood flow in BC. According to experimental results, PI depends significantly on the characteristics of the blood samples (i.e., hematocrit or base solutions) and can be used effectively as an alternative to blood viscosity. In addition, SEAI and EAI also depend significantly on the degree of RBC aggregation. In conclusion, on the basis of three indices (two RBC aggregation indices and pressure index), the proposed method is capable of measuring RBCs aggregation consistently using a microfluidic device.
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Browne, Vaughn A., Colleen G. Julian, Lillian Toledo-Jaldin, Darleen Cioffi-Ragan, Enrique Vargas e Lorna G. Moore. "Uterine artery blood flow, fetal hypoxia and fetal growth". Philosophical Transactions of the Royal Society B: Biological Sciences 370, n.º 1663 (5 de março de 2015): 20140068. http://dx.doi.org/10.1098/rstb.2014.0068.
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Evolutionary trade-offs required for bipedalism and brain expansion influence the pregnancy rise in uterine artery (UtA) blood flow and, in turn, reproductive success. We consider the importance of UtA blood flow by reviewing its determinants and presenting data from 191 normotensive (normal, n = 125) or hypertensive (preeclampsia (PE) or gestational hypertension (GH), n = 29) Andean residents of very high (4100–4300 m) or low altitude (400 m, n = 37). Prior studies show that UtA blood flow is reduced in pregnancies with intrauterine growth restriction (IUGR) but whether the IUGR is due to resultant fetal hypoxia is unclear. We found higher UtA blood flow and Doppler indices of fetal hypoxia in normotensive women at high versus low altitude but similar fetal growth. UtA blood flow was markedly lower in early-onset PE versus normal high-altitude women, and their fetuses more hypoxic as indicated by lower fetal heart rate, Doppler indices and greater IUGR. We concluded that, despite greater fetal hypoxia, fetal growth was well defended by higher UtA blood flows in normal Andeans at high altitude but when compounded by lower UtA blood flow in early-onset PE, exaggerated fetal hypoxia caused the fetus to respond by decreasing cardiac output and redistributing blood flow to help maintain brain development at the expense of growth elsewhere. We speculate that UtA blood flow is not only an important supply line but also a trigger for stimulating the metabolic and other processes regulating feto-placental metabolism and growth. Studies using the natural laboratory of high altitude are valuable for identifying the physiological and genetic mechanisms involved in human reproductive success.
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Bouhemad, Bélaïd, Fabio Ferrari, Kris Leleu, Charlotte Arbelot, Qin Lu e Jean-Jacques Rouby. "Echocardiographic Doppler Estimation of Pulmonary Artery Pressure in Critically Ill Patients with Severe Hypoxemia". Anesthesiology 108, n.º 1 (1 de janeiro de 2008): 55–62. http://dx.doi.org/10.1097/01.anes.0000296067.02462.34.
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Background In spontaneously breathing cardiac patients, pulmonary artery pressure (PAP) can be accurately estimated from the transthoracic Doppler study of pulmonary artery and tricuspid regurgitation blood flows. In critically ill patients on mechanical ventilation for acute lung injury, the interposition of gas between the probe and the heart renders the transthoracic approach problematic. This study was aimed at determining whether the transesophageal approach could offer an alternative. Methods Fifty-one consecutive sedated and ventilated patients with severe hypoxemia (arterial oxygen tension/fraction of inspired oxygen < 300) were prospectively studied. Mean PAP measured from the pulmonary artery catheter was compared with several indices characterizing pulmonary artery blood flow assessed using transesophageal echocardiography: preejection time, acceleration time, ejection duration, preejection time on ejection duration ratio, and acceleration time on ejection duration ratio. In a subgroup of 20 patients, systolic PAP measured from the pulmonary artery catheter immediately before withdrawal was compared with Doppler study of regurgitation tricuspid flow performed immediately after pulmonary artery catheter withdrawal using either the transthoracic or the transesophageal approach. Results Weak and clinically irrelevant correlations were found between mean PAP and indices of pulmonary artery flow. A statistically significant and clinically relevant correlation was found between systolic PAP and regurgitation tricuspid flow. In 3 patients (14%), pulmonary artery pressure could not be assessed echocardiographically. Conclusions In hypoxemic patients on mechanical ventilation, mean PAP cannot be reliably estimated from indices characterizing pulmonary artery blood flow. Systolic PAP can be estimated from regurgitation tricuspid flow using either transthoracic or transesophageal approach.
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Kang, Yang. "A Disposable Blood-on-a-Chip for Simultaneous Measurement of Multiple Biophysical Properties". Micromachines 9, n.º 10 (20 de setembro de 2018): 475. http://dx.doi.org/10.3390/mi9100475.
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Biophysical properties are widely used to detect pathophysiological processes of vascular diseases or clinical states. For early detection of cardiovascular diseases, it is necessary to simultaneously measure multiple biophysical properties in a microfluidic environment. However, a microfluidic-based technique for measuring multiple biophysical properties has not been demonstrated. In this study, a simple measurement method was suggested to quantify three biophysical properties of blood, including red blood cell (RBC) deformability, RBC aggregation, and hematocrit. To demonstrate the suggested method, a microfluidic device was constructed, being composed of a big-sized channel (BC), a parallel micropillar (MP), a main channel, a branch channel, inlet, and outlets. By operating a single syringe pump, blood was supplied into the inlet of the microfluidic device, at a periodic on-off profile (i.e., period = 240 s). The RBC deformability index (DI) was obtained by analyzing the averaged blood velocity in the branch channel. Additionally, the RBC aggregation index (AIN) and the hematocrit index (HiBC) were measured by analyzing the image intensity of blood flows in the MP and the BC, respectively. The corresponding contributions of three influencing factors, including the turn-on time (Ton), the amplitude of blood flow rate (Q0), and the hematocrit (Hct) on the biophysical indices (DI, AIN, and HiBC) were evaluated quantitatively. As the three biophysical indices varied significantly with respect to the three factors, the following conditions (i.e., Ton = 210 s, Q0 = 1 mL/h, and Hct = 50%) were maintained for consistent measurement of biophysical properties. The proposed method was employed to detect variations of biophysical properties depending on the concentrations of autologous plasma, homogeneous hardened RBCs, and heterogeneous hardened RBCs. Based on the observations, the proposed method exhibited significant differences in biophysical properties depending on base solutions, homogeneous hardened RBCs (i.e., all RBCs fixed with the same concentration of glutaraldehyde solution), and heterogeneous hardened RBCs (i.e., partially mixed with normal RBCs and homogeneous hardened RBCs). Additionally, the suggested indices (i.e., DI, AIN, and HiBC) were effectively employed to quantify three biophysical properties, including RBC deformability, RBC aggregation, and hematocrit.
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Toubaei, S. "Blood Flow of Carotid Arteries in Schizophrenic Patients". European Psychiatry 24, S1 (janeiro de 2009): 1. http://dx.doi.org/10.1016/s0924-9338(09)71439-7.
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Background:Based on new imaging, some results have led to the hypothesis, indicating left hemispheric dysfunction in schizophrenic patients,Transcranial color Doppler sonography also showed significant blood flow velocity changes in schizophrenic patients.Our study tried to clarify possible differences between carotid blood flow of each side, in symptom positive and symptom negative schizophrenic patients, as well as differences of blood flow between schizophrenic patients versus control cases.Methods:31 schizophrenic patients which had been selected randomly were divided in two separate groups of symptom positive (14 cases) and symptom negative (17 cases) patients, according to PANSS test. Then carotid color Doppler sonography was performed for them and for 32 control cases.Velosities (PSV, DV) and Doppler indices (RL, PI) were measured to be compared statistically in patients and control cases.Results:According to P value < 0.05 as level of significance in all comparisons, no evidence of any significant differences is seen between two sides of patients(positive symptoms and negative symptoms) as though between control cases and patients. No positive conclusion also derived based on sex interference.Conclusion:So examination reveals no differences between carotid blood flows of two sides in schizophrenic patients(positive and negative symptom).There is no differences between carotid blood flow of patients and control group, even when sex interfered as a variety.
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Tiederman, W. G., M. J. Steinle e W. M. Phillips. "Two-Component Laser Velocimeter Measurements Downstream of Heart Valve Prostheses in Pulsatile Flow". Journal of Biomechanical Engineering 108, n.º 1 (1 de fevereiro de 1986): 59–64. http://dx.doi.org/10.1115/1.3138581.
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Elevated turbulent shear stresses resulting from disturbed blood flow through prosthetic heart valves can cause damage to red blood cells and platelets. The purpose of this study was to measure the turbulent shear stresses occurring downstream of aortic prosthetic valves during in-vitro pulsatile flow. By matching the indices of refraction of the blood analog fluid and model aorta, correlated, simultaneous two-component laser velocimeter measurements of the axial and radial velocity components were made immediately downstream of two aortic prosthetic valves. Velocity data were ensemble averaged over 200 or more cycles for a 15-ms window opened at peak systolic flow. The systolic duration for cardiac flows of 8.4 L/min was 200 ms. Ensemble-averaged total shear stress levels of 2820 dynes/cm2 and 2070 dynes/cm2 were found downstream of a trileaflet valve and a tilting disk valve, respectively. These shear stress levels decreased with axial distance downstream much faster for the tilting disk valve than for the trileaflet valve.
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Gelsomino, Sandro, Pieter Willem Lozekoot, Roberto Lorusso, Monique Maria de Jong, Orlando Parise, Francesco Matteucci, Fabiana Lucà et al. "A New 35-mm Short Intra-aortic Balloon Catheter: A Suitable Option also for Non-Small-Sized Patients?" Innovations: Technology and Techniques in Cardiothoracic and Vascular Surgery 11, n.º 1 (janeiro de 2016): 46–53. http://dx.doi.org/10.1097/imi.0000000000000233.
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Objective Visceral ischemia can be a potentially life-threatening complication of intra-aortic balloon pump (IABP) support. A shorter IABP catheter might lead to a reduction of visceral complications. In this animal study, we evaluate the effects of a 35-mL short catheter in comparison with a 40-mL standard-sized catheter. Methods Eighteen healthy swine underwent 120-minute ligation of the left anterior descending coronary artery followed by 6 hours of reperfusion being supported by either a short IABP catheter (short group) (n = 6) or a long IABP catheter (long group) (n = 6) or with no assistance (controls) (n = 6). Hemodynamics, visceral and coronary flows, as well as biochemical markers were evaluated throughout the different phases of the protocol. Results Mesenteric flows increased significantly at reperfusion (P < 0.001 both) remaining constant afterward (all, P > 0.05) in the short group, while remaining significantly lower in the long group at the start of reperfusion, remaining constantly lower than the short group and controls (P < 0.001 vs short, P < 0.003 vs controls). In both long and short groups, catheters improved renal flows at reperfusion (P < 0.001 both) without any further variation (P < 0.05). In the short group, the flows were higher during the whole of reperfusion (all, P < 0.05). Intra-aortic balloon pump support improved hemodynamic indices and coronary blood flows during reperfusion to a similar extent in both the small and the long group (P > 0.05). Conclusions The short IABP catheter proved to be as effective as the standard-sized catheter in supporting hemodynamics and coronary circulation. Furthermore, it even improves visceral flows in comparison with conventional IABP catheters.
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Mandolfo, S., F. Galli, S. Costa, P. Ravani, P. Gaggia e E. Imbasciati. "Factors Influencing Permanent Catheter Performance". Journal of Vascular Access 2, n.º 3 (julho de 2001): 106–9. http://dx.doi.org/10.1177/112972980100200304.
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Permanent dual lumen catheters (PDLC) provide an alternative vascular access in patients considered unsuitable for arteriovenous fistula, graft or peritoneal dialysis. However, the use of PDLC is often complicated by inadequate blood flow. The aim of this study was to identify catheter dysfunctions. We studied prospectively 57 chronic hemodialyzed patients, 73±11 years of age, with PDLC for 18±14 (1–48) months. Catheters were tunneled in silicone (MedComp Tesio n= 40) or in polyurethane (Permcath Quinton n = 11, GamCath Gambro n = 6) in left or right internal jugular (n = 49), in left or right subclavian (n = 3) and in right femoral vein (n = 5). We studied the blood viscosity indices (hematocrit, total protein, cholesterol and triglycerides), catheter intra-dialytic parameters (pre-pump and venous pressure), localization of the catheter tip (superior vena cava = SVC, right atrium = RA, inferior vena cava = IVC), blood pressure before and after hemodialysis during the 3 last dialyses, use of anticoagulant (ACT) or antiaggregant therapy (AAT) and previous infectious episodes. The mean blood flow was 269±37 ml/min (median 280 ml/min). The patients were divided according to the median value into groups I (Qb < 280, n = 28) and group II (Qb > 280, n =29). Results: Blood viscosity, patients’ mean arterial pressure and venous catheter line pressure did not differ between the two groups. Pre-pump pressure, at the start and at the end of treatment, was higher in group I. ACT, AAT and previous infectious episodes could not explain the low-performance. Blood flows of catheters localized in RA, SVC, and in IVC were respectively 287±20, 268±39, 244±27 ml/min. In the first case the Qb was significantly higher than IVC (p = 0.03) and SVC (p = 0.04). In conclusion, the most important factor influencing blood flow rates seems to be the position of the catheter tip in the venous system. The best blood flows were found in catheters with the tip localized in the right cardiac cavities, while PLDC placed in inferior vena cava showed lower blood flow.
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Hazari, Vajihe, Fatemeh Sarvi, Ashraf Alyasin, Marzieh Agha-Hosseini e Sedigheh Hosseinimousa. "Effectiveness the perfusion of Endometrial and Subendometrial and Endometrial volume on the endometrial receptivity of FET Cycles". Obstetrics Gynecology and Reproductive Sciences 5, n.º 7 (25 de setembro de 2021): 01–06. http://dx.doi.org/10.31579/2578-8965/067.
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Objective: this study was effects of endometrial and subendometrial blood perfusion and endometrial volume on endometrial receptivity in frozen embryo transfer (FET) cycles. Materials and methods: This prospective observational cohort study, that on infertile women who referred for FET to Shariati Hospital and Omid Infertility Clinic in Tehran (Iran) .112 patients selected among eligible women with good quality embryos. After homogenization, participants underwent endometrial preparation for hormone replacement therapy (HRT) according to a similar routine protocol. On the day of the FET, they underwent a thorough ultrasound examination for possible effective parameters. Subsequently, one to two good quality blastocysts were transferred, and the pregnancy outcomes were monitored. Results: In vitro fertilization (IVF) was performed on 112 patients with a mean age of 33.93±4.93 years. Although, serum β-HCG level was used to confirm pregnancy. Accordingly, out of 112 participating patients, 50 (44.6%) became pregnant after IVF. Based on the results of this study, the endometrial blood flow was significantly different between the two groups of pregnant and non-pregnant women, so that a higher pregnancy rate was observed in participants with multi-focal and spare endometrial blood flows (P<0.05). Additionally, a significant relationship between endometrial blood flow and pregnancy outcome so that there was more ongoing pregnancy rates in those with multi-focal and spare endometrial blood flows (P<0.05). But the endometrial variables of volume, length, width, thickness and pattern were not significantly different between the two groups of pregnant and non-pregnant women. Moreover, contextual parameters had no significant relationship with pregnancy outcome (P>0.05). Endometrial measurement indices were also ineffective on pregnancy outcomes and no significant difference was there between the groups (P>0.05). Conclusion: Collectively, the endometrial blood flow can play an effective role in improving pregnancy event and its stability after IVF, but the endometrial volume was unable to predict pregnancy event and its stability after IVF.
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Nestola, Maria G. C., Alessio Gizzi, Christian Cherubini e Simonetta Filippi. "Three-band decomposition analysis in multiscale FSI models of abdominal aortic aneurysms". International Journal of Modern Physics C 27, n.º 02 (23 de dezembro de 2015): 1650017. http://dx.doi.org/10.1142/s0129183116500170.
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Computational modeling plays an important role in biology and medicine to assess the effects of hemodynamic alterations in the onset and development of vascular pathologies. Synthetic analytic indices are of primary importance for a reliable and effective a priori identification of the risk. In this scenario, we propose a multiscale fluid-structure interaction (FSI) modeling approach of hemodynamic flows, extending the recently introduced three-band decomposition (TBD) analysis for moving domains. A quantitative comparison is performed with respect to the most common hemodynamic risk indicators in a systematic manner. We demonstrate the reliability of the TBD methodology also for deformable domains by assuming a hyperelastic formulation of the arterial wall and a Newtonian approximation of the blood flow. Numerical simulations are performed for physiologic and pathologic axially symmetric geometry models with particular attention to abdominal aortic aneurysms (AAAs). Risk assessment, limitations and perspectives are finally discussed.
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Henao, Daniel A., Benjamin J. Sprague, Terrance M. Phernetton, Naomi C. Chesler e Ronald R. Magness. "Effect of Gravidity on Uterine Blood Flows Relative to Structural and Mechanical Indices of Remodeling in Uterine Arteries During the Ovine Ovarian Cycle vs. Pregnancy." Biology of Reproduction 81, Suppl_1 (1 de julho de 2009): 89. http://dx.doi.org/10.1093/biolreprod/81.s1.89.
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Grazuleviciene, Regina, Sandra Andrusaityte, Audrius Dėdelė, Tomas Grazulevicius, Leonas Valius, Aurimas Rapalavicius, Violeta Kapustinskiene e Inga Bendokiene. "Urban Environment and Health: A Cross-Sectional Study of the Influence of Environmental Quality and Physical Activity on Blood Pressure". International Journal of Environmental Research and Public Health 18, n.º 11 (6 de junho de 2021): 6126. http://dx.doi.org/10.3390/ijerph18116126.
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Few studies have examined the relation between urban built environment and the prevalence of hypertension. This cross-sectional study aimed at assessing the relationship between the environmental quality, physical activity, and stress on hypertension among citizens of Kaunas city, Lithuania. We conducted a survey of 1086 citizens residing in 11 districts to determine their perceptions of environmental quality, health behavior, and health indices. The independent variables included residential traffic flows, access to public transportation and green spaces. Dependent variables included physician-diagnosed hypertension, systolic and diastolic blood pressure, and stress level. We used multivariable logistic regression to assess the associations as odds ratios (OR). The environmental factors beneficially associated with meeting the physical activity recommendations were opportunities for walking to reach the city’s green spaces and available relaxation areas. Residents of high noise level districts aged 45–64 years had a significantly higher OR of stress and a higher prevalence of hypertension when age, sex, education status, family status, and smoking were accounted for. However, meeting the physical activity recommendations had a beneficial effect on the risk of hypertension. This study provided evidence that improvement of the district-level built environment supporting citizens’ physical activity might reduce the risk of hypertension.
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Polglase, Graeme R., Stuart B. Hooper, Martin Kluckow, Andrew W. Gill, Richard Harding e Timothy J. M. Moss. "The cardiopulmonary haemodynamic transition at birth is not different between male and female preterm lambs". Reproduction, Fertility and Development 24, n.º 3 (2012): 510. http://dx.doi.org/10.1071/rd11121.
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Males born preterm are at greater risk of illness and death than females, principally due to respiratory disease. Much of the excess morbidity occurs within the first few hours of life. Therefore, the aim of the present study was to investigate whether or not differences in the cardiopulmonary transition soon after birth underlie the increased morbidity in males after preterm birth. Nine female and thirteen male lambs (128 ± 2 days gestation) underwent surgery immediately before delivery for implantation of a pulmonary arterial flow-probe and catheters into the main pulmonary artery and a carotid artery. After birth lambs were ventilated for 30 min (tidal volume 7 mL kg–1) while anaesthetised. Arterial pressures and flows were recorded in real time and left-ventricular output measured using Doppler echocardiography. Before birth, fetal cardiopulmonary haemodynamics, arterial blood gases, pH, glucose and lactate did not differ between sexes. Similarly, in the neonatal period there were no significant differences in arterial blood gas status, ventilation parameters, respiratory indices or cardiopulmonary haemodynamics between the sexes. Our data show that the cardiopulmonary transition at birth in ventilated, anaesthetised preterm lambs is not influenced by sex. Thus, the neonatal ‘male disadvantage’ is not explained by an impaired cardiovascular transition at birth.
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Morel, Olivier, Frederic Pachy, Pascale Chavatte Palmer, Michel Bonneau, Etienne Gayat, Patrice Laigre e Vassilis Tsatsaris. "W13.6 Correlation between the three-dimensional power Doppler quantified indices and the real blood flows within the utero-placental unit: evaluation in a pregnant sheep experimental model". Pregnancy Hypertension: An International Journal of Women's Cardiovascular Health 1 (outubro de 2010): S38. http://dx.doi.org/10.1016/s2210-7789(10)60154-7.
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Yokoyama, Tadashi, Ryoji Okamoto, Yuzo Yamamoto, Dai Manaka, Hirokazu Sasaki, Masanobu Washida, Toshiyuki Kitai et al. "Hepatic energy status in hypotension of different aetiologies in dogs". Clinical Science 81, n.º 5 (1 de novembro de 1991): 627–33. http://dx.doi.org/10.1042/cs0810627.
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1. The alterations in hepatic energy metabolism in hypotension induced by the administration of trimetaphan camsylate (Arfonad) were investigated in comparison with those produced by hypotension resulting from massive haemorrhage by measuring the arterial ketone body ratio, which reflects the hepatic mitochondrial redox state, and other indices of hepatic energy metabolism together with simultaneous measurement of hepatic blood flow in dogs. 2. Mean arterial blood pressure was decreased from 130 mmHg to 60 mmHg by the continuous intravenous infusion of trimetaphan camsylate or by the use of Wiggers' shock model. In hypotension induced by trimetaphan camsylate, the arterial ketone body ratio, ATP and total adenine nucleotide concentrations and energy charge were maintained at near-control values throughout the experimental period. By contrast, the arterial ketone body ratio decreased from 1.04 ±0.09 to 0.29 ±0.06 at 3 h after haemorrhage in Wiggers' shock model (P <0.01). The ATP and total adenine nucleotide concentrations and energy charge also decreased significantly in this model (P <0.05). The difference in hepatic energy status was also shown by data from 31P nuclear magnetic resonance spectroscopy. 3. During hypotension, portal venous and total hepatic blood flows diminished significantly compared with the control values in each group (P <0.01). Although there was no significant difference in total hepatic flow between the two groups, the portal venous blood flow in hypotension induced by trimetaphan camsylate was significantly higher than that in Wiggers' shock model (P <0.05). 4. During hypotension induced by trimetaphan camsylate, the hepatic energy metabolism was well maintained at the mean arterial blood pressure value of 60 mmHg, but in haemorrhagic hypotension it was severely curtailed, although there was no significant difference in total hepatic blood flow between the two groups. It is conjectured that the portal venous blood flow contributes significantly to the maintenance of hepatic energy metabolism and hepatic tissue perfusion during hypotension induced by trimetaphan camsylate.
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Cohen, Eytan, Kevin Murphy, Lewis Adams, Abraham Guz e Gila Benchetrit. "Is Voluntary Control of Breathing Impaired in Patients with Chronic Obstructive Pulmonary Disease?" Clinical Science 88, n.º 4 (1 de abril de 1995): 453–61. http://dx.doi.org/10.1042/cs0880453.
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1. To assess whether voluntary control of breathing is impaired in patients with chronic obstructive pulmonary disease, a group of such patients performed a tracking task, requiring volitional control of respiratory muscles. 2. Eight patients (mean age 60 years; mean ratio of forced expiratory volume in 1 s to forced vital capacity = 31%) took part in the study. Five of the seven patients in whom blood gas measurements were made were mildly hypoxaemic (Pao2 = 53–71 mmHg), and one of these was hypercapnic (Paco2 = 55 mmHg). Each subject performed a compensatory ventilatory tracking task using a tracking system which comprised a fixed target displayed on a monitor screen and a cursor moving in a line bisecting the target. The position of the cursor was perturbed by a forcing function and patients were required to keep the cursor on the target by breathing in and out of a spirometer. 3. To allow for any non-specific deficiency in motor control, patients performed a similar manual tracking task, using their dominant arm to move a joystick. As a control group, 11 healthy subjects (mean age 58 years; mean ratio of forced expiratory volume in 1 s to forced vital capacity = 77%) underwent an identical experimental protocol. 4. Motor control performances were measured in terms of the error between the target position and the subject's positioning of the cursor. Indices of performance were the root mean square of the error and the averages of the zero errors (i.e. end expiration/arm movement towards the trunk) and the peak errors (i.e. end inspiration/arm movement from the trunk). 5. For manual tracking, patients with chronic obstructive pulmonary disease, were not significantly different from control subjects in terms of mean root mean square (69.3 versus 60.9), mean zero error (93.8 versus 72.2) or mean peak error (99.5 versus 82.7). For ventilatory tracking, mean root mean square was significantly higher in patients (83.4 versus 65.9). This was due to a significantly higher mean zero error (101.4 versus 66.1); mean peak error was not significantly different (68.3 versus 82.1). Comparison of flows achieved during ventilatory tracking with those possible during a maximal forced expiratory manoeuvre in the patients suggested that poor expiratory control in this group could be explained by their degree of airflow limitation rather than a deficiency in motor control per se. 6. These results provide no evidence that patients with chronic obstructive pulmonary disease have any impairment in their voluntary motor control of breathing.
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Faraci, F. M., e M. R. Fedde. "Regional circulatory responses to hypocapnia and hypercapnia in bar-headed geese". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 250, n.º 3 (1 de março de 1986): R499—R504. http://dx.doi.org/10.1152/ajpregu.1986.250.3.r499.
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To investigate mechanisms that may allow birds to tolerate extreme high altitude (hypocapnic hypoxia), we examined the effects of severe hypocapnia and moderate hypercapnia on regional blood flow in bar-headed geese (Anser indicus), a species that flies at altitudes up to 9,000 m. Cerebral, coronary, and pectoral muscle blood flows were measured using radioactive microspheres, while arterial CO2 tension (PaCO2) was varied from 7 to 62 Torr in awake normoxic birds. Arterial blood pressure was not affected by hypocapnia but increased slightly during hypercapnia. Heart rate did not change during alterations in PaCO2. Severe hypocapnia did not significantly alter cerebral, coronary, or pectoral muscle blood flow. Hypercapnia markedly increased cerebral and coronary blood flow, but pectoral muscle blood flow was unaffected. The lack of a blood flow reduction during severe hypocapnia may represent an important adaptation in these birds, enabling them to increase O2 delivery to the heart and brain at extreme altitude despite the presence of a very low PaCO2.
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Silas, Ekuyikeno, Selaelo Ivy Tshilwane e Samson Mukaratirwa. "Cytokines, Chemokines, Insulin and Haematological Indices in Type 2 Diabetic Male Sprague Dawley Rats Infected with Trichinella zimbabwensis". Applied Sciences 12, n.º 15 (1 de agosto de 2022): 7743. http://dx.doi.org/10.3390/app12157743.
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Diabetes mellitus is a chronic metabolic disease induced by the inability to control high blood glucose level. Helminth-induced immunomodulation has been reported to prevent or delay the onset of type 2 diabetes mellitus (T2DM), which, in turn, ameliorates insulin sensitivity. Therefore, there is a need to understand the underlying mechanisms utilized by helminths in metabolism and the induction of immuno-inflammatory responses during helminthic infection and T2DM comorbidity. This study aimed at using a laboratory animal model to determine the cytokines, chemokines and haematological indices in diabetic (T2DM) male Sprague Dawley (SD) rats infected with Trichinella zimbabwensis. One hundred and two male SD rats (160–180 g) were randomly selected into three experimental groups (i. T2DM-induced group (D) ii. T. zimbabwensis infected + T2DM group (TzD) and iii. T. zimbabwensis-infected group (Tz)). Rats selected for the D group and TzD group were injected with 40 mg/kg live weight of streptozotocin (STZ) intraperitoneally to induce T2DM, while animals in the Tz and TzD group were infected with T. zimbabwensis. Results showed that adult T. zimbabwensis worm loads and mean T. zimbabwensis larvae per gram (lpg) of rat muscle were significantly higher (p < 0.001) in the Tz group when compared to the TzD group. Blood glucose levels in the D group were significantly higher (p < 0.001) compared to the TzD group. An increase in insulin concentration was observed among the TzD group when compared to the D group. Liver and muscle glycogen decreased in the D when compared to the TzD group. A significant increase (p < 0.05) in red blood cells (RBCs) was observed in the D group when compared to the TzD and Tz groups. An increase in haematocrit, haemoglobin, white blood cells (WBCs), platelet, neutrophils and monocyte were observed in the D group when compared to the TzD group. TNF-α, IFN-γ, IL-4, IL-10 and IL-13 concentrations were elevated in the TzD group when compared to the D and Tz groups, while IL-6 concentration showed a significant reduction in the Tz when compared to the D and the TzD groups. A significant increase in CCL5 in the D and TzD groups was observed in comparison to the Tz group. CXCL10 and CCL11 concentration also showed an increase in the TzD group in comparison to the Tz and the D groups. Overall, our results confirm that T. zimbabwensis, a parasite which produces tissue-dwelling larvae in the host, regulates T2DM driven inflammation to mediate a positive protective effect against T2DM outcomes.
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Mejía-Mejía, Elisa, e Panicos A. Kyriacou. "Photoplethysmography-Based Pulse Rate Variability and Haemodynamic Changes in the Absence of Heart Rate Variability: An In-Vitro Study". Applied Sciences 12, n.º 14 (18 de julho de 2022): 7238. http://dx.doi.org/10.3390/app12147238.
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Pulse rate variability (PRV), measured from pulsatile signals such as the photoplethysmogram (PPG), has been largely used in recent years as a surrogate of heart rate variability (HRV), which is measured from electrocardiograms (ECG). However, different studies have shown that PRV does not always replicate HRV as there are multiple factors that could affect their relationship, such as respiration and pulse transit time. In this study, an in-vitro model was developed for the simulation of the upper-circulatory system, and PPG signals were acquired from it when haemodynamic changes were induced. PRV was obtained from these signals and time-domain, frequency-domain and non-linear indices were extracted. Factorial analyses were performed to understand the effects of changing blood pressure and flow on PRV indices in the absence of HRV. Results showed that PRV indices are affected by these haemodynamic changes and that these may explain some of the differences between HRV and PRV. Future studies should aim to replicate these results in healthy volunteers and patients, as well as to include the HRV information in the in-vitro model for a more profound understanding of these differences.
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Sun, Zhihong, Yan Zhang, Datao Xu, Yaqi Fei, Qiner Qiu e Yaodong Gu. "The Effects of Six-Month Subalpine Training on the Physical Functions and Athletic Performance of Elite Chinese Cross-Country Skiers". Applied Sciences 12, n.º 1 (2 de janeiro de 2022): 421. http://dx.doi.org/10.3390/app12010421.
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Purpose: This study investigated the changes in the blood indices, specific athletic abilities, and physical fitness of outstanding cross-country skiers, trained in the subalpine; Methods: Twenty-eight athletes (twenty males and eight females) from the National Cross-country Ski Training Team completed sub-alpine training during the 2020–2021 snow season. The athletes′ physical functions were evaluated by collecting blood from elbow veins and measuring blood biochemical indexes. To compare the treadmill roller-skiing athletic ability and physical fitness of athletes before and after subalpine; Results: Male and female athletes showed different trends in red blood cells (RBC), hemoglobin (Hb), cortisol (C), Creatine Kinase (CK) and blood urea (BU) (p < 0.05 or p < 0.01). Overall, the female athletes’ mean values of RBC, Hb, CK, and BU were lower than that of male athletes, while C was just the opposite. Comparing the athletic performance of athletes before and after the subalpine, it was found that blood lactate concentrations were significantly lower in both male and female athletes at the same load intensity (p < 0.05 or p < 0.01), whereas 10 km endurance running and 1 RM deep squat were significantly higher in both male and female athletes (p < 0.05 or p < 0.01). Conclusions: After 6 months of subalpine training, cross-country skiers improved their oxygen-carrying capacity and anabolism, and showed significant improvements in specific athletic ability, physical endurance, acid tolerance and 1 RM absolute strength for both male and female athletes.
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Saha, Shubhajit, Azubuike V. Chukwuka, Dip Mukherjee, Lipika Patnaik, Susri Nayak, Kishore Dhara, Nimai Chandra Saha e Caterina Faggio. "Chronic Effects of Diazinon® Exposures Using Integrated Biomarker Responses in Freshwater Walking Catfish, Clarias batrachus". Applied Sciences 11, n.º 22 (18 de novembro de 2021): 10902. http://dx.doi.org/10.3390/app112210902.
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Diazinon exposures have been linked to the onset of toxic pathways and adverse outcomes in aquatic species, but the ecological implications on model species are not widely emphasized. The objective of this study was to determine how the organophosphate pesticide diazinon affected hematological (hemoglobin, total red blood count, total white blood count, and mean corpuscular hemoglobin), growth (condition factor, hepatosomatic index, specific growth rate), biochemical (total serum glucose, total serum protein), and endocrine (growth hormone, tri-iodothyronine, and thyroxine) parameters in Clarias batrachus after chronic exposure. Diazinon was administered at predefined exposure doses (0.64 and 1.28 mg/L) and monitored at 15, 30, and 45 days into the investigation. Observation for most biomarkers revealed patterns of decreasing values with increasing toxicant concentration and exposure duration. Correlation analysis highlighted a significant inverse relationship between variables (mean corpuscular hemoglobin, condition factor, specific growth rate, tri-iodothyronine, thyroxine, and total serum protein) and elevated chronic diazinon exposure concentrations. The integrated indices (IBR and BRI) indexes were used to provide visual and understandable depictions of toxicity effects and emphasized the relativity of biomarkers in terms of sensitivity and magnitude or severity of responses under graded toxicant exposures. The significant damage reflected by evaluated parameters in diazinon exposure groups compared to control portends risks to the health of local fish populations, including Clarias batrachus in aquatic systems adjacent to agrarian landscapes.
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Galali, Yaseen, Gail Rees e Victor Kuri. "The Impact of Waxy Wheat Flour, Inulin and Guar Gum on Post-Prandial Glycaemic and Satiety Indices, Sensory Attributes and Shelf Life of Tandoori and Pita Breads". Applied Sciences 12, n.º 7 (25 de março de 2022): 3355. http://dx.doi.org/10.3390/app12073355.
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The purpose of this study was to develop two different functional breads (Pita and Tandoori) supplemented with novel functional ingredients: waxy wheat flour (15%), inulin (8%) and guar gum (2%) independently and in combination. The breads were submitted to sensory characteristics, shelf life, glycaemic and satiety indices assessments. Both guar gum and inulin independently and in combination significantly (p < 0.05) decreased post-prandial blood glucose and glycemic response of Pita (GI of guar gum bread was 55%, inulin 57%) and Tandoori (GI of guar gum bread was 57% and inulin bread was 60%) compared to the control breads (GI 100%). Moreover, the results of the area under the curve of satiety showed that the addition of functional ingredients increased satiety levels as follows: for Pita, control was 355, a combination of all ingredients was 418, inulin was 451 and guar gum was 452; for Tandoori, control was 329, a combination of all ingredients was 420, inulin was 381 and guar gum was 390. The results showed that all sensory characteristics were improved, and breads were acceptable (all obtained more than five points) when the highest proportions of ingredients were added. Similarly, the shelf life of supplemented Pita and Tandoori breads was improved with the addition of ingredients. Therefore, the functional ingredients such as inulin and guar gum can be used independently and in combination to reduce GI and increase satiety of Pita and Tandoori bread with acceptable quality and shelf life.
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Alanazi, Ahmed Z., Mohamed Mohany, Fawaz Alasmari, Ramzi A. A. Mothana, Abdulaziz O. A. Alshehri, Khalid Alhazzani, Mohammed M. Ahmed e Salim S. Al-Rejaie. "Amelioration of Diabetes-Induced Nephropathy by Loranthus regularis: Implication of Oxidative Stress, Inflammation and Hyperlipidaemia". Applied Sciences 11, n.º 10 (17 de maio de 2021): 4548. http://dx.doi.org/10.3390/app11104548.
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In traditional Yemeni medicine, various preparations of Loranthus regularis (L. regularis), such as powder, decoctions and infusions are commonly used to treat diabetes, kidney stone formations and inflammation. In the present study, we evaluated the antinephrotoxic effects of L. regularis extract in experimentally-induced diabetes in male Wistar rats. A single dose (60 mg/kg/day) of Streptozotocin (STZ) was used to induce type 1 diabetes. Animals were then treated for four weeks with L. regularis extract (150 or 300 mg/kg/day) by oral gavage. Renal and blood samples were subsequently harvested. Several biochemical indices, oxidative stress and inflammatory markers were assessed. Additionally, histological alterations in the renal tissue were examined. Serum glucose levels were significantly (p < 0.01) lowered while insulin levels were enhanced in L. regularis-treated diabetic animals. The increased renal markers in diabetic rats were decreased by L. regularis treatment. Serum elevated lipid profiles were markedly decreased by the plant extract. The serum and renal cytokines that were significantly increased (p < 0.001) by STZ were diminished by L. regularis treatment. Finally, renal tissue antioxidant enzymatic activity was enhanced with L. regularis treatment. Taken together, the data here indicate that L. regularis possesses therapeutic ability to reduce the development of diabetic nephropathy (DN) by minimizing oxidative injury and inflammation.
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Kandil, Heba, Ahmed Soliman, Nada Elsaid, Ahmed Saied, Norah Saleh Alghamdi, Ali Mahmoud, Fatma Taher e Ayman El-Baz. "Studying the Role of Cerebrovascular Changes in Different Compartments in Human Brains in Hypertension Prediction". Applied Sciences 12, n.º 9 (24 de abril de 2022): 4291. http://dx.doi.org/10.3390/app12094291.
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Hypertension is a major cause of mortality of millions of people worldwide. Cerebral vascular changes are clinically observed to precede the onset of hypertension. The early detection and quantification of these cerebral changes would help greatly in the early prediction of the disease. Hence, preparing appropriate medical plans to avoid the disease and mitigate any adverse events. This study aims to investigate whether studying the cerebral changes in specific regions of human brains (specifically, the anterior, and the posterior compartments) separately, would increase the accuracy of hypertension prediction compared to studying the vascular changes occurring over the entire brain’s vasculature. This was achieved by proposing a computer-aided diagnosis system (CAD) to predict hypertension based on cerebral vascular changes that occur at the anterior compartment, the posterior compartment, and the whole brain separately, and comparing corresponding prediction accuracy. The proposed CAD system works in the following sequence: (1) an MRA dataset of 72 subjects was preprocessed to enhance MRA image quality, increase homogeneity, and remove noise artifacts. (2) each MRA scan was then segmented using an automatic adaptive local segmentation algorithm. (3) the segmented vascular tree was then processed to extract and quantify hypertension descriptive vascular features (blood vessels’ diameters and tortuosity indices) the change of which has been recorded over the time span of the 2-year study. (4) a classification module used these descriptive features along with corresponding differences in blood pressure readings for each subject, to analyze the accuracy of predicting hypertension by examining vascular changes in the anterior, the posterior, and the whole brain separately. Experimental results presented evidence that studying the vascular changes that take place in specific regions of the brain, specifically the anterior compartment reported promising accuracy percentages of up to 90%. However, studying the vascular changes occurring over the entire brain still achieve the best accuracy (of up to 100%) in hypertension prediction compared to studying specific compartments.
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Guo, Fumin, Matthew Ng, Idan Roifman e Graham Wright. "Cardiac Magnetic Resonance Left Ventricle Segmentation and Function Evaluation Using a Trained Deep-Learning Model". Applied Sciences 12, n.º 5 (3 de março de 2022): 2627. http://dx.doi.org/10.3390/app12052627.
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Cardiac MRI is the gold standard for evaluating left ventricular myocardial mass (LVMM), end-systolic volume (LVESV), end-diastolic volume (LVEDV), stroke volume (LVSV), and ejection fraction (LVEF). Deep convolutional neural networks (CNNs) can provide automatic segmentation of LV myocardium (LVF) and blood cavity (LVC) and quantification of LV function; however, the performance is typically degraded when applied to new datasets. A 2D U-net with Monte-Carlo dropout was trained on 45 cine MR images and the model was used to segment 10 subjects from the ACDC dataset. The initial segmentations were post-processed using a continuous kernel-cut method. The refined segmentations were employed to update the trained model. This procedure was iterated several times and the final updated U-net model was used to segment the remaining 90 ACDC subjects. Algorithm and manual segmentations were compared using Dice coefficient (DSC) and average surface distance in a symmetric manner (ASSD). The relationships between algorithm and manual LV indices were evaluated using Pearson correlation coefficient (r), Bland-Altman analyses, and paired t-tests. Direct application of the pre-trained model yielded DSC of 0.74 ± 0.12 for LVM and 0.87 ± 0.12 for LVC. After fine-tuning, DSC was 0.81 ± 0.09 for LVM and 0.90 ± 0.09 for LVC. Algorithm LV function measurements were strongly correlated with manual analyses (r = 0.86–0.99, p < 0.0001) with minimal biases of −8.8 g for LVMM, −0.9 mL for LVEDV, −0.2 mL for LVESV, −0.7 mL for LVSV, and −0.6% for LVEF. The procedure required ∼12 min for fine-tuning and approximately 1 s to contour a new image on a Linux (Ubuntu 14.02) desktop (Inter(R) CPU i7-7770, 4.2 GHz, 16 GB RAM) with a GPU (GeForce, GTX TITAN X, 12 GB Memory). This approach provides a way to incorporate a trained CNN to segment and quantify previously unseen cardiac MR datasets without needing manual annotation of the unseen datasets.
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Asif, Mishal, Syed Muhammad Yousaf Farooq, Talha Saleemee, Muhammad Talha Asif, Zartash Gull, Hafsa Talat, Taiba Suleman, Ayesha Mudassar, Muhammad Kamran e Irfan Ullah. "Comparison of Uterine Artery Dynamics in Normotensive and Hypertensive Pregnancies on Doppler Ultrasound". Pakistan Journal of Medical and Health Sciences 16, n.º 6 (30 de junho de 2022): 793–96. http://dx.doi.org/10.53350/pjmhs22166793.
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Background: Hypertension during pregnancy is a common disease that can alter the health of both mothers and fetus. It is a leading cause of maternal, fetal, and neonatal death, as well as an increased risk of having an undesirable pregnancy outcome. Objective: To compare uterine artery dynamics in normotensive and gestational hypertensive pregnancies on Doppler ultrasound. Methodology: A cross-sectional case control study was carried out in Radiology department of District Head Quarter (DHQ) hospital, Faisalabad. Written consent was taken from all patients before the ultrasound examination. The calculated sample size was 98. Patients were assessed for eligibility in inclusion criteria. Confirmation of intrauterine living pregnancy and gestational age was done with routine obstetric ultrasound. Enrolled pregnant patients both normal and hypertensive were assessed for uterine artery Doppler ultrasound examination. Results: Ninety eight women, forty-nine with hypertension and forty-nine normal women participated in the investigation. The comparison of data showed that pre pregnancy weight and mean blood pressure were significantly high in hypertensive group when compared to the normotensive group (P <0.05). Doppler ultrasound also showed that the values of uterine artery parameters such as S/D Ratio, PI, RI was significantly high in hypertensive group when compared to the normotensive group (P <0.05). Conclusion: The Uterine artery Doppler parameters are significantly higher in hypertensive patients as compared to normotensive patients. According to the findings of our study, notching on the right, left, or bilateral, as well as Pulsatility index and Resistivity Index, are diagnostic parameters for evaluating the complications before they worsen. Keywords: Uterine artery, Gestational hypertension, Doppler Ultrasound, Doppler Indices, Pre-Eclampsia
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Salem, Hanaa, Mahmoud Y. Shams, Omar M. Elzeki, Mohamed Abd Elfattah, Jehad F. Al-Amri e Shaima Elnazer. "Fine-Tuning Fuzzy KNN Classifier Based on Uncertainty Membership for the Medical Diagnosis of Diabetes". Applied Sciences 12, n.º 3 (18 de janeiro de 2022): 950. http://dx.doi.org/10.3390/app12030950.
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Diabetes, a metabolic disease in which the blood glucose level rises over time, is one of the most common chronic diseases at present. It is critical to accurately predict and classify diabetes to reduce the severity of the disease and treat it early. One of the difficulties that researchers face is that diabetes datasets are limited and contain outliers and missing data. Additionally, there is a trade-off between classification accuracy and operational law for detecting diabetes. In this paper, an algorithm for diabetes classification is proposed for pregnant women using the Pima Indians Diabetes Dataset (PIDD). First, a preprocessing step in the proposed algorithm includes outlier rejection, imputing missing values, the standardization process, and feature selection of the attributes, which enhance the dataset’s quality. Second, the classifier uses the fuzzy KNN method and modifies the membership function based on the uncertainty theory. Third, a grid search method is applied to achieve the best values for tuning the fuzzy KNN method based on uncertainty membership, as there are hyperparameters that affect the performance of the proposed classifier. In turn, the proposed tuned fuzzy KNN based on uncertainty classifiers (TFKNN) deals with the belief degree, handles membership functions and operation law, and avoids making the wrong categorization. The proposed algorithm performs better than other classifiers that have been trained and evaluated, including KNN, fuzzy KNN, naïve Bayes (NB), and decision tree (DT). The results of different classifiers in an ensemble could significantly improve classification precision. The TFKNN has time complexity O(kn2d), and space complexity O(n2d). The TFKNN model has high performance and outperformed the others in all tests in terms of accuracy, specificity, precision, and average AUC, with values of 90.63, 85.00, 93.18, and 94.13, respectively. Additionally, results of empirical analysis of TFKNN compared to fuzzy KNN, KNN, NB, and DT demonstrate the global superiority of TFKNN in precision, accuracy, and specificity.
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Hassan, Menna Allah Kamal, Mohamed Mohsen Elnamory, Ayman Abd Elaziz Eldorf e Hesham Mohamed Eltokhy. "The Effect of Methyl Dopa, Nifedipine and Labetalol Treatment on Uterine, Umbilical and Fetal Middle Cerebral Artery Blood Flows in Cases Suffered from Pregnancy Induced Hypertension". Journal of Advances in Medicine and Medical Research, 27 de outubro de 2021, 84–94. http://dx.doi.org/10.9734/jammr/2021/v33i2131136.
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Background: Treatment of severe maternal hypertension is strongly indicated for the prevention of maternal complications, such as cerebrovascular accidents and placental abruption, for avoiding extreme pre maturity. The selection criteria for the various antihypertensive drugs are somewhat unclear, and although vasodilator agents reducing peripheral vascular resistance (e.g., methyldopa, nifidipine and labetalol) have been accepted for general obstetric use. The aim of the study is to compare the effect of methyl dopa, nifedipine and labetalol treatment on the doppler indices of uterine, umbilical and fetal middle cerebral artery blood flows in cases suffered from pregnancy induced hypertension.
Methods: This prospective randomized comparative clinical trial study was carried out on 75 pregnant women suffered from pregnancy-induced hypertension. The patients were divided into three equal groups: Group I: received alpha methyldopa750 mg-2000 mg per day, Group II: received labetalol 100 mg twice per day and Group III: received nifedipine oral sustained tablets 20-120mg per day.
Results: Follow up of the patients was done with assessment of the outcome measures and statistical analysis was done and revealed that the use of alpha methyldopa, nifedipine and labatalol in pregnancy induced hypertension cases produce significant reduction of blood pressure ,prolong pregnancy duration, decrease the need for maternal admission to the ICU due to uncontrolled severe hypertension, decrease insignificantly the progression of mild preeclampsia to severe preeclampsia without producing negative effect on the mother or the fetus because these drugs did not impair the uteroplacental or middle cerebral blood flow documented by Doppler studies.
Conclusions: Use of methyl dopa, nifidipine and labetalol treatment in PIH cases make an improvement of uteroplacental and middle cerebral blood flow which indicated by maternal uterine, umbilical and fetal middle cerebral arteries doppler indices (resistive index, pulatility index and S/D ratio). Labetalol is ideal first line of treatment because it has potent and fast hypotensive effect without producing significant side effects on the mother or fetus.
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Ma, SKT, WC Sin, CW Ngai, ASK Wong, WM Chan e PY Ng. "Flow manipulation and the association with myocardial contractility during extracorporeal life support (FLAME)". European Heart Journal. Acute Cardiovascular Care 10, Supplement_1 (1 de abril de 2021). http://dx.doi.org/10.1093/ehjacc/zuab020.030.
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Abstract Funding Acknowledgements Type of funding sources: None. Background Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is an advanced technique in extracorporeal life support (ECLS) used to support extreme circulatory failure including patients with cardiac arrest and cardiogenic shock refractory to conventional support. It is a long-standing belief that peripheral V-A ECMO poses increased afterload to the inured heart, but conventional echocardiographic measurements are often insensitive in detecting subtle changes in loading conditions. Purpose This study aimed to evaluate the effects of varying blood flow during peripheral V-A ECMO on intrinsic myocardial contractility, using detailed echocardiographic assessment including speckle tracking echocardiography (STE). Methods Adult patients with acute cardiogenic shock who were supported by peripheral V-A ECMO from April 2019 to September 2020 were recruited. Serial hemodynamic and cardiac performance parameters were measured by transthoracic echocardiogram (TTE) within 48 hours after implementation of V-A ECMO, at different levels of extracorporeal blood flow – 100%, 120% and 50% of target blood flow (TBF). Results A total of 30 patients were included. 22 (71%) were male, and the mean (SD) age was 54 (13) years. The major indications for V-A ECMO were myocardial infarction (19, 63% patients), and myocarditis (5, 17%). With a decrease in extracorporeal blood flow from 100% to 50% of TBF, mean arterial pressure (MAP) dropped from 76+/-3 to 64+/-3mmHg (p <0.001), and cardiac index (CI) increased from 0.89+/-0.13 to 1.27+/-0.18L/min/m2 (p < 0.001). All indices of left ventricular contractility improved at a lower extracorporeal blood flow: the myocardial contractility measured by global longitudinal peak systolic strain (GLPSS) improved from -3+/-0.7% to -5+/-0.8% (p < 0.001); left ventricular ejection fraction (LVEF) increased from 21.5+/-2.6% to 30.9+/-2.7% (p < 0.001) and 19.7+/-3.1% to 28.4+/-3.2% (p < 0.001) by biplane and linear methods, respectively; left ventricular index of myocardial performance (LIMP) improved from 1.51+/-0.12 to 1.03+/-0.09 (p < 0.001). Similar findings were reproduced when comparing left ventricular contractility at extracorporeal blood flows of 120% and 50% of TBF. Conclusions The ECMO blood flow rate in peripheral V-A ECMO is inversely related to myocardial contractility, and is quantifiable by myocardial strain measured by STE.
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Vorobeva, Darya A., Vyacheslav V. Ryabov, Julia G. Lugacheva, Konstantin V. Zavadovsky e Andrew V. Mochula. "Relationships between indicators of prothrombotic activity and coronary microvascular dysfunction in patients with myocardial infarction with obstructive and non-obstructive coronary artery disease". BMC Cardiovascular Disorders 22, n.º 1 (6 de dezembro de 2022). http://dx.doi.org/10.1186/s12872-022-02985-z.
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Abstract The relationship between prothrombotic activity and coronary microvascular dysfunction (MVD) is limited. This study aimed to perform a comparative analysis of the relationship between prothrombotic activity and MVD in patients with myocardial infarction without obstructive coronary artery disease (MINOCA) and myocardial infarction with obstructive coronary artery disease (MI-CAD). Material and methods A total of 37 patients were enrolled in the study; the main group included 16 MINOCA patients, and 21 MI-CAD patients were included in the control group. Blood samples for protein C, antithrombin, WF, plasminogen, and homocysteine were performed on the 4th ± 1 day of admission. CZT-SPECT data were used to determine the standard indices of myocardial perfusion dis-orders (SSS, SRS, and SDS), as well as stress and rest myocardial blood flow (MBF), myocardial flow reserve (MFR), and difference flows (DF). MVD was defined as MFR (≤ 1.91 ml/min); coronary slow flow (CSF) was defined as corrected TIMI frame count (21 ± 3). Results We performed a step-by-step analysis of prothrombotic activity of the hemostasis system in binary logistic regression for MINOCA patients to identify factors associated with MVD (MFR ≤ 1.91 ml/min). A predictive model was developed to estimate the probability of reduced MFR. A low MFR is related to only plasminogen in MINOCA patients, whereas only wall motion score index (WMSI) in MI-CAD group was associated with a low MFR. Conclusion This small-scale study revealed the relationship between indicators of prothrombotic activity and MVD. The key factors that affect MVD in MINOCA patients was plasminogen, whereas, in patients with MI-CAD, WMSI was the key factor. Measurements of MVD may enhance the risk stratification and facilitate future targeting of adjunctive antithrombotic therapies in MINOCA and MI-CAD patients.
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Remde, Alan, Stephen N. DeTurk, A. Almardini, Lauren Steiner e Thomas Wojda. "Plant-predominant eating patterns – how effective are they for treating obesity and related cardiometabolic health outcomes? – a systematic review". Nutrition Reviews, 8 de setembro de 2021. http://dx.doi.org/10.1093/nutrit/nuab060.
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Abstract Context The obesity epidemic is a main driver of the chronic disease epidemic; however, present treatment approaches have suboptimal efficacy. Objectives To assess the efficacy of plant-predominant (vegan, vegetarian, plant-based whole foods [PBWFs]) diets in treating obesity and its main cardiometabolic sequelae: hyperlipidemia (HLD); indices of insulin resistance, glycemic control, and diabetes mellitus type 2 (DM2); and cardiovascular disease (CVD), including hypertension (HTN). Data Sources A systematic search of multiple databases was conducted for articles published between November 2019 and February 2020; databases searched included: PubMed, Medline (Ovid), Cochrane, CENTRAL, and CINAHL. Data Extraction and Analysis All interventional trials (randomized controlled trials [RCTs] and trials of non-randomized experimental design) that met the inclusion criteria (English language, duration of at least 4 weeks, primary end point congruent with above objectives, no major flaws in research design that would prevent interpretation) were included in the review. A total of 3135 articles were scanned and 84 were selected. The articles were collated and summarized in 2 evidence tables. Risk of bias for RCTs was assessed using the Cochrane Risk-of-Bias tool 2 as a guide. For non-randomized trials, higher risk of bias was assumed, and the JBI Critical Appraisal tool was used as a guide to determine inclusion. Results Plant-based diets, in general, demonstrated improved weight control and cardiometabolic outcomes related to lipids, cardiovascular end points, blood pressure, insulin sensitivity, A1C, and fasting glucose, and a lower risk of diabetes compared with usual diets and in some cases standard health-oriented diets such as the American Heart Association (AHA), American Diabetic Association (ADA), and Mediterranean diets. Preliminary studies suggest plant-predominant diets practiced as part of healthy lifestyle interventions may stabilize or even reverse DM 2 and CVD. The acceptability and sustainability of plant-predominant diets where measured were generally similar to other health-oriented diets. Conclusion Plant-predominant diets can play a major role in reversing the obesity and chronic disease epidemics. In the setting of sustained lifestyle intervention programs, they may arrest or even reverse DM2 and CVD. Further higher-level RCTs are needed to confirm and expand on these findings.