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Biomedical subjects

S S Sobin

Publications and source records attributed to S S Sobin.

At least 37 records · Page 2Linked to original sources
PubMed1981

Computer-derived image compositing.

A computer-derived composite image is obtained of the details contained in successive photomicrographs taken by optical sectioning of the collagen networks in the pulmonary interalveolar wall. Three-dimensional information is therefore contained in a two-dimensional portrayal, providing a basis for computer digital analysis otherwise not readily available.

Computers↗
PubMed1981

Redistribution of canine left ventricular myocardial blood flow in unloaded systole.

The left coronary arteries of dogs were cannulated and perfused with blood from support dogs. The experimental hearts were unloaded by severing the aortas to maximize strains and minimize fiber stress. In each heart we compared the transmural distribution of blood flow in two states: (1) provision of perfusion pressure (40 mm Hg) only during systole and then (2) provision of perfusion pressure throughout the cardiac cycle. The distribution of flow in each of these perfusion states was labeled with a diffusible radioisotope (42K or 86Rb, one labeling the first state; the other labeling the second). Quantitative, paired autoradiography was used to visualize the two flow distributions. The differences between the two distributions after standardization was plotted as differences between activity vs. depth in the myocardium (r = 0.91). This was fitted with a line by least squares, the slope of which was significantly different from zero at the 0.005 level. The magnitude of the gradient of the systolic flow was represented by the ratio of deep to shallow flow. The mean of these ratios was 0.54 +/- 0.12 (95% confidence interval). A graphical analysis shows that the data are consistent with a gradient of extravascular compression across the left ventricular wall.

Animals↗
PubMed1980

Intralamellar blood flow patterns in fish gills.

The dimensions of the lamellar vascular sheet in ling cod gills were examined over a range of transmural pressures (delta Plam). The mean vascular sheet thickness (h) increased linearly with delta Plam over the range 30-60 cmH2O, where h = 8.36 + 0.07 delta Plam. The vascular space-to-tissue ratio, however, was unchanged over the pressure range examined. Thus sheet flow equations, formerly derived for the interalveolar wall of the mammalian lungs, can be used to describe blood flow through the lamellae. Predictions were made on the distribution of blood flow within the lamella. When delta Plam and flow are raised, blood flow is redistributed away from the base of the lamella, since regional variations exist in the thickness and the vascular compliance of the lamellar sheet. Variations in the pattern of intralamellar blood flow are likely to affect gas transfer in the gills.

Animals↗