Partition Coefficient of 133Xe between Blood and Eye Tissues

1975 ◽  
Vol 14 (04) ◽  
pp. 301-309
Author(s):  
A. Marczak ◽  
A. Moszczyńska-Kowalska ◽  
H. Kowalski
Keyword(s):  
Partition Coefficient ◽  
Aqueous Humour ◽  
Vitreous Body ◽  
Flow Measurements ◽  
Solubility Coefficient ◽  
Eye Muscles ◽  
Eye Tissues ◽  
Relative Solubility ◽  
Blood Flow Measurements

SummaryThe relative solubility coefficient of 133Xe and the tissue-blood partition coefficient for the aqueous humour vitreous body, conjunctiva and external eye muscles of the rabbit were determined in vitro at 37° C and at various haematocrit values. The partition coefficient for haematocrit 40 was: for the aqueous humour 0,49 ml/ml, for the vitreous body 0,50 ml/ml, for the conjunctiva 0,81 ml/g and for the external eye muscles 0,77 ml/g. It was found that the solubility of 133Xe in rabbit erythrocytes is about 50 per cent higher than that in human red cells. The consequences of this fact for the precision of blood flow measurements by the method of tissue clearance are discussed.

Increased number of myocardial blood flow measurements with radionuclide-labeled microspheres

1984 ◽  
Vol 246 (3) ◽  
pp. H418-H434 ◽  
Author(s):  
R. W. Baer ◽  
B. D. Payne ◽  
E. D. Verrier ◽  
G. J. Vlahakes ◽  
D. Molodowitch ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Least Squares ◽  
Reference Sample ◽  
Separation Technique ◽  
Fixed Amount ◽  
Flow Measurements ◽  
Coronary Pressure ◽  
Blood Flow Measurements

We evaluated the use of a least-squares radionuclide separation technique to allow an increased number of myocardial blood flow measurements with radionuclide-labeled microspheres in dogs. Two sets of labeled microspheres were studied: a set of eight labeled with 125I, 153Gd, 57Co, 51Cr, 113Sn, 85Sr, 95Nb, and 46Sc; and a set of nine in which 125I and 46Sc were replaced with 114In, 54Mn, and 65Zn. For each microsphere label the nuclide activities determined by least-squares separation compared favorably with those actually added to in vitro samples containing a fixed amount of the other nuclides in the set. For the set of eight radionuclide-labeled microspheres, myocardial flow measurements made with the least-squares separation technique and the reference sample method were usually within 15% and almost all within 20% of direct measurements of coronary venous outflow in a right heart bypass preparation. Serial left atrial injections of 15-micron microspheres totaling 48 X 10(6) caused no significant changes in systemic hemodynamics, regional myocardial flows, or coronary pressure-flow relations, whether the coronary bed was autorelating or vasodilated with chromonar. We conclude that at least nine myocardial blood flow measurements can be made in dogs with acceptable accuracy and without evidence of dysfunction due to embolization of the coronary vascular bed. With appropriate validation, this method should be applicable to other organs and animal models as well.

scholarly journals Contemporary possibilities in the diagnostics of anterior and posterior eye diseases with the use of new-generation OCT

2021 ◽  
Vol 8 (2) ◽  
pp. 81-86
Author(s):  
Katarzyna Paczwa ◽  
Justyna Mędrzycka ◽  
Joanna Gołębiewska ◽  
Radosław Różycki
Keyword(s):  
Laser Scanning ◽  
Vitreous Body ◽  
Posterior Segment ◽  
Eye Diseases ◽  
Imaging Method ◽  
Flow Measurements ◽  
Precise Evaluation ◽  
Meibomian Glands ◽  
Blood Flow Measurements ◽  
New Generation

Optical coherence tomography is a non-contact imaging method of the anterior and posterior segments of the eye that is based on laser scanning in spectral domain. This study presents diagnostic possibilities of the new generation Solix FullRange™ OCT&OCTA apparatus (Optovue) to examine meibomian glands, cornea, anterior chamber, as well iridocorneal angles and lens. In the posterior segment of the eye it allows for the precise evaluation of the vitreous body, choroid, retina, optic nerve and blood-flow measurements.

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