The Flow of Sickle Blood Through Glass Capillaries and Its Diagnostic Implications

2021 ◽  
Author(s):  
Christopher D. Brown
Keyword(s):  
1989 ◽  
Vol 62 (03) ◽  
pp. 989-995 ◽  
Author(s):  
Juliette N Mulvihill ◽  
J Andrew Davies ◽  
Florence Toti ◽  
Jean-Marie Freyssinet ◽  
Jean-Pierre Cazenave

SummaryThe generation of trace amounts of thrombin at artificial surfaces in contact with blood is likely to be a contributing factor in thrombosis on biomaterials. Using an in vitro capillary perfusion system, platelet accumulation on glass surfaces, uncoated or precoated with purified bovine collagen or human plasma proteins, was determined in the presence or absence of preadsorbed purified human thrombin. Static adsorption for 15 min at 22° C from solutions of thrombin 100 NIH units (33 μg)/ml gave surface concentrations in the range 0.019-0.101 μg/cm2. Protein coated capillaries, thrombin treated or untreated, were perfused for 2 min at 37° C with suspensions of washed 111In-labeled human platelets in Tyrode's-albumin buffer containing 40% washed red blood cells, under conditions of controlled, non pulsatile laminar flow (50 s−1 or 2,000 s−1). Platelet accumulation was increased in the presence of surface adsorbed thrombin on uncoated and albumin or fibrinogen coated glass but little affected on fibronectin or collagen coated glass. On von Willebrand factor (vWF) coated glass, thrombin enhancement was observed only at high shear forces. In experiments using antibodies against human platelet α-granule proteins, thrombin stimulated platelet deposition in uncoated glass capillaries was inhibited at 2,000 s−1 by anti-vWF and to a lesser extent by anti-fibrinogen but not by antithrombospondin antibodies.


CHEST Journal ◽  
2001 ◽  
Vol 120 (5) ◽  
pp. 1651-1654 ◽  
Author(s):  
Marie Pia d’Ortho ◽  
Christophe Delclaux ◽  
Francoise Zerah ◽  
Robert Herigault ◽  
Serge Adnot ◽  
...  

1982 ◽  
Vol 241 (1) ◽  
pp. 41-48 ◽  
Author(s):  
T. Welsch ◽  
R. Müller ◽  
W. Engewald ◽  
G. Werner

1978 ◽  
Vol 76 (3) ◽  
pp. 652-674 ◽  
Author(s):  
I B Täljedal

Pancreatic islets, or suspensions of islet cells, from noninbred ob/ob-mice were incubated with chlorotetracycline and analyzed for Ca2+-dependent fluorescence in a microscope. Unless logarithmically transformed, signals from islets were asymmetrically distributed with unstable variance. Signals from cells pelleted in glass capillaries were more homogeneous and depended linearly on the thickness of the sample. The effect of sample thickness and a significant enhancement of fluorescence by alloxan suggest that beta-cells were involved in producing the signal from whole islets. The signal from dispersed cells was probably diagnostic of Ca2+ in beta-cell plasma membranes because it was suppressed by La3+ and had a spectrum indicative of an apolar micromilieu; fluorescent staining of cell surfaces was directly seen at high magnification. Fluorescence from cells was enhanced by 0.5-10 mM Ca2+ in a dose-dependent manner, whereas less than 0.5 mM Ca2+ saturated the probe alone in methanol. The signal from islets or dispersed cells was suppressed by 5 mM theophylline; that from cells was also suppressed by 0.5 mM 3-isobutyl-1-methylxanthine, 1.2 or 15 mM Mg2+, 3-20 mM D-glucose, and, to a lesser extent, 20 mM 3-O-methyl-D-glucose. D-glucose was more inhibitory in the absence than in the presence of Mg2+, as if Mg2+ and D-glucose influenced the same Ca2+ pool. L-glucose, D-mannopheptulose, or diazoxide had no noticeable effect and 20 mM bicarbonate was stimulatory. The results suggest that microscopy of chlorotetracycline-stained cells can aid in characterizing calcium pools of importance for secretion. Initiation of insulin release may be associated with an increas


1996 ◽  
Vol 3 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Yoji Suzuki ◽  
Norihiko Tateishi ◽  
Masao Soutani ◽  
Nobuji Maeda

1963 ◽  
Vol 18 (5) ◽  
pp. 1041-1042 ◽  
Author(s):  
Curt A. Wiederhielm

A system which permits continuous recording of dimensions of microscopic blood vessels is described. The system utilizes information contained in the video signal of a television microscope to develop an analog voltage proportional to the time required for the electron beam to sweep across the image of the blood vessel. This time interval is also proportional to the dimension of the vessel. Calibration of the system yielded a standard error of estimate of ±3.7 μ on a series of glass capillaries, ranging in size from 15 to 150 μ. The rise time of the system was in the order of 40 msec. Long- and short-term drift was less than 3 μ/hr. The system is used in an experimental study of viscoelastic properties of small arteries and arterioles. microcirculation; viscoelastic properties; frog mesentery Submitted on April 17, 1963


Sign in / Sign up

Export Citation Format

Share Document