scholarly journals Renal Perfusion during Hemodialysis: Intradialytic Blood Flow Decline and Effects of Dialysate Cooling

2019 ◽  
Vol 30 (6) ◽  
pp. 1086-1095 ◽  
Author(s):  
Raanan Marants ◽  
Elena Qirjazi ◽  
Claire J. Grant ◽  
Ting-Yim Lee ◽  
Christopher W. McIntyre
Keyword(s):  
Myocardial Stunning ◽  
Statistical Significance ◽  
Ischemic Injury ◽  
Residual Renal Function ◽  
Renal Perfusion ◽  
Circulatory Stress ◽  
The Brain ◽  
Perfusion Maps ◽  
Renal Computed Tomography

BackgroundResidual renal function (RRF) confers survival in patients with ESRD but declines after initiating hemodialysis. Previous research shows that dialysate cooling reduces hemodialysis-induced circulatory stress and protects the brain and heart from ischemic injury. Whether hemodialysis-induced circulatory stress affects renal perfusion, and if it can be ameliorated with dialysate cooling to potentially reduce RRF loss, is unknown.MethodsWe used renal computed tomography perfusion imaging to scan 29 patients undergoing continuous dialysis under standard (36.5°C dialysate temperature) conditions; we also scanned another 15 patients under both standard and cooled (35.0°C) conditions. Imaging was performed immediately before, 3 hours into, and 15 minutes after hemodialysis sessions. We used perfusion maps to quantify renal perfusion. To provide a reference to another organ vulnerable to hemodialysis-induced ischemic injury, we also used echocardiography to assess intradialytic myocardial stunning.ResultsDuring standard hemodialysis, renal perfusion decreased 18.4% (P<0.005) and correlated with myocardial injury (r=−0.33; P<0.05). During sessions with dialysis cooling, patients experienced a 10.6% decrease in perfusion (not significantly different from the decline with standard hemodialysis), and ten of the 15 patients showed improved or no effect on myocardial stunning.ConclusionsThis study shows an acute decrease in renal perfusion during hemodialysis, a first step toward pathophysiologic characterization of hemodialysis-mediated RRF decline. Dialysate cooling ameliorated this decline but this effect did not reach statistical significance. Further study is needed to explore the potential of dialysate cooling as a therapeutic approach to slow RRF decline.

Characterization of Ischemic Stroke in CT Images using Image Processing

2017 ◽  
Vol 7 (9) ◽  
pp. 18
Author(s):  
Amal Alzain ◽  
Suhaib Alameen ◽  
Rani Elmaki ◽  
Mohamed E. M. Gar-Elnabi
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Classification Accuracy ◽  
Ct Images ◽  
Gray Level ◽  
Level Variation ◽  
Interactive Data ◽  
The Brain ◽  
Brain Tissues

This study concern to characterize the brain tissues to ischemic stroke, gray matter, white matter and CSF using texture analysisto extract classification features from CT images. The First Order Statistic techniques included sevenfeatures. To find the gray level variation in CT images it complements the FOS features extracted from CT images withgray level in pixels and estimate the variation of thesubpatterns. analyzing the image with Interactive Data Language IDL software to measure the grey level of images. The results show that the Gray Level variation and   features give classification accuracy of ischemic stroke 97.6%, gray matter95.2%, white matter 97.3% and the CSF classification accuracy 98.0%. The overall classification accuracy of brain tissues 97.0%.These relationships are stored in a Texture Dictionary that can be later used to automatically annotate new CT images with the appropriate brain tissues names.

Implantable neural interfaces

2018 ◽  
Author(s):  
Stefano Vassanelli
Keyword(s):  
Brain Function ◽  
Large Scale ◽  
Ionic Channels ◽  
Patch Clamp Technique ◽  
Advantages And Disadvantages ◽  
Optogenetic Stimulation ◽  
Physical Interfaces ◽  
The Brain

Establishing direct communication with the brain through physical interfaces is a fundamental strategy to investigate brain function. Starting with the patch-clamp technique in the seventies, neuroscience has moved from detailed characterization of ionic channels to the analysis of single neurons and, more recently, microcircuits in brain neuronal networks. Development of new biohybrid probes with electrodes for recording and stimulating neurons in the living animal is a natural consequence of this trend. The recent introduction of optogenetic stimulation and advanced high-resolution large-scale electrical recording approaches demonstrates this need. Brain implants for real-time neurophysiology are also opening new avenues for neuroprosthetics to restore brain function after injury or in neurological disorders. This chapter provides an overview on existing and emergent neurophysiology technologies with particular focus on those intended to interface neuronal microcircuits in vivo. Chemical, electrical, and optogenetic-based interfaces are presented, with an analysis of advantages and disadvantages of the different technical approaches.

Predictors of Faster Decline of Residual Renal Function in Taiwanese Peritoneal Dialysis Patients

2008 ◽  
Vol 28 (3_suppl) ◽  
pp. 191-195 ◽  
Author(s):  
Chia-Te Liao ◽  
Chih-Chung Shiao ◽  
Jenq-Wen Huang ◽  
Kuan-Yu Hung ◽  
Hsueh-Fang Chuang ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Renal Function ◽  
Peritoneal Dialysis ◽  
Clinical Laboratory ◽  
Statistical Significance ◽  
Univariate Analysis ◽  
Residual Renal Function ◽  
Measure Data ◽  
Chi Square ◽  
Artery Disease

⋄ Objective Loss of residual renal function (RRF) in peritoneal dialysis (PD) patients is a powerful predictor of mortality. The present study was conducted to determine the predictors of faster decline of RRF in PD patients in Taiwan. ⋄ Methods The study enrolled 270 patients starting PD between January 1996 and December 2005 in a single hospital in Taiwan. We calculated RRF as the mean of the sum of 24-hour urea and creatinine clearance. The slope of the decline of residual glomerular filtration rate (GFR) was the main outcome measure. Data on demographic, clinical, laboratory, and treatment parameters; episodes of peritonitis; and hypotensive events were analyzed by Student t-test, Mann–Whitney U-test, and chi-square, as appropriate. All variables with statistical significance were included in a multivariate linear regression model to select the best predictors ( p < 0.05) for faster decline of residual GFR. ⋄ Results All patients commencing PD during the study period were followed for 39.4 ± 24.0 months (median: 35.5 months). The average annual rate of decline of residual GFR was 1.377 ± 1.47 mL/min/m2. On multivariate analysis, presence of diabetes mellitus ( p < 0.001), higher baseline residual GFR ( p < 0.001), hypotensive events ( p = 0.001), use of diuretics ( p = 0.002), and episodes of peritonitis ( p = 0.043) independently predicted faster decline of residual GFR. Male sex, old age, larger body mass index, and presence of coronary artery disease or congestive heart failure were also risk factors on univariate analysis. ⋄ Conclusions Our results suggested that diabetes mellitus, higher baseline residual GFR, hypotensive events, and use of diuretics are independently associated with faster decline of residual GFR in PD patients in Taiwan.

scholarly journals The orthopedic characterization of cfap298tm304 mutants validate zebrafish to faithfully model human AIS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marie-Hardy Laura ◽  
Cantaut-Belarif Yasmine ◽  
Pietton Raphaël ◽  
Slimani Lotfi ◽  
Pascal-Moussellard Hugues
Keyword(s):  
Cerebrospinal Fluid ◽  
Three Dimensional ◽  
Fluid Circulation ◽  
Micro Computed Tomography ◽  
Csf Flow ◽  
Cerebrospinal Fluid Circulation ◽  
Clinical Criteria ◽  
Brain And Spinal Cord ◽  
The Brain

AbstractCerebrospinal fluid (CSF) circulation relies on the beating of motile cilia projecting in the lumen of the brain and spinal cord cavities Mutations in genes involved in cilia motility disturb cerebrospinal fluid circulation and result in scoliosis-like deformities of the spine in juvenile zebrafish. However, these defects in spine alignment have not been validated with clinical criteria used to diagnose adolescent idiopathic scoliosis (AIS). The aim of this study was to describe, using orthopaedic criteria the spinal deformities of a zebrafish mutant model of AIS targeting a gene involved in cilia polarity and motility, cfap298tm304. The zebrafish mutant line cfap298tm304, exhibiting alteration of CSF flow due to defective cilia motility, was raised to the juvenile stage. The analysis of mutant animals was based on micro-computed tomography (micro-CT), which was conducted in a QUANTUM FX CALIPER, with a 59 µm-30 mm protocol. 63% of the cfap298tm304 zebrafish analyzed presented a three-dimensional deformity of the spine, that was evolutive during the juvenile phase, more frequent in females, with a right convexity, a rotational component and involving at least one dislocation. We confirm here that cfap298tm304 scoliotic individuals display a typical AIS phenotype, with orthopedic criteria mirroring patient’s diagnosis.

Significance tests: Necessary but not sufficient

1998 ◽  
Vol 21 (2) ◽  
pp. 221-222
Author(s):  
Louis G. Tassinary
Keyword(s):  
Effect Size ◽  
Scientific Community ◽  
Statistical Significance ◽  
Significance Tests ◽  
Experimental Control

Chow (1996) offers a reconceptualization of statistical significance that is reasoned and comprehensive. Despite a somewhat rough presentation, his arguments are compelling and deserve to be taken seriously by the scientific community. It is argued that his characterization of literal replication, types of research, effect size, and experimental control are in need of revision.

scholarly journals Pretreatment with Monosialoganglioside GM1 Protects the Brain of Fetal Sheep against Hypoxic-Ischemic Injury without Causing Systemic Compromise

1993 ◽  
Vol 34 (1) ◽  
pp. 18-22 ◽  
Author(s):  
William K M Tan ◽  
Chris E Williams ◽  
Alistair J Gunn ◽  
E Carina Mallard ◽  
Peter D Gluckman
Keyword(s):  
Ischemic Injury ◽  
Fetal Sheep ◽  
The Brain ◽  
Hypoxic Ischemic Injury

scholarly journals Characterization of calcium-dependent membrane binding proteins of brain cortex

1985 ◽  
Vol 229 (3) ◽  
pp. 587-593 ◽  
Author(s):  
A R Rhoads ◽  
M Lulla ◽  
P B Moore ◽  
C E Jackson
Keyword(s):  
Brain Cortex ◽  
Peptide Mapping ◽  
Bovine Brain ◽  
Particulate Fraction ◽  
Structural Homology ◽  
One Dimensional ◽  
Calcium Dependent ◽  
Stokes Radius ◽  
The Brain

Proteins of Mr 68 000, 34 000 and 32 000 were selectively extracted by EGTA from brain cortex. The three proteins that were extracted along with calmodulin were acidic, monomeric, and did not exhibit structural homology, as demonstrated by one-dimensional peptide mapping. The Mr-68 000 protein was purified to homogeneity and had a Stokes radius of 3.54 nm and S20,W value of 5.1S. Purified calmodulin, Mr-68 000 protein and two proteins of Mr 34 000 and Mr 32 000, interacted with the brain particulate fraction, with half-maximal binding occurring at 3.5 microM, 8.3 microM and 150 microM-Ca2+ respectively. Proteins were bound independently of each other and calmodulin. Pretreatment of the particulate fraction with trypsin prevented the Ca2+-dependent binding of calmodulin; however, the binding of the Mr-68 000 protein or the Mr−32 000 and −34 000 proteins was unaffected. The Mr-68 000 protein of bovine brain did not cross-react immunologically with Mr-67 000 calcimedin from chicken gizzard.

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