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C Martin

Publications and source records attributed to C Martin.

At least 1,099 records · Page 61Linked to original sources
PubMed1980

Application of two multi-dimensional analytical methods to histological study of the aorta in dietary atherosclerosis of the rabbit.

Multivariate analysis (principal component analysis, discriminant analysis) have been applied to the histological data of arterial lesions in experimental atherosclerosis of the rabbit. We carried out a comparative study of: 1. the lesion observed at three levels of the aortas; origin of the aorta, thoracic aorta and abdominal aorta, and 2. the lesions according to the type of fat ingested during the experimental period. Five edible fats were studied: butter, olive oil, arachid oil, rapeseed oil rich in erucic acid, and rapeseed oil poor in erucic acid (Primor). This study re-affirms the possible importance of the above mentioned methods in evaluation by histology of lesions induced in the arteries by the different hyperlipidic regimens. Indeed these methods are complementary and enable the introduction of statistical methods in the quantitative evaluation of morphological lesions.

Animals↗
PubMed1980

Correlation of in vivo bioavailability of erythromycin stearate tablets with in vitro tests.

Correlations between the bioavailability parameters for erythromycin stearate tablets from five manufacturers and in vitro tests of these tablets were examined using forward (stepwise), multiple linear regression analysis. Bioavailability parameters were determined in clinical studies employing a balanced, incomplete block design. In vitro tests used disintegration, dissolution, and dissolution/dialysis as the independent variables in regression equations. Significant correlations were found between linear combinations of these parameters and the time of peak and the peak serum levels. The inclusion of an in vitro disintegration test to describe peak serum levels of erythromycin is noteworthy since it has been suggested that disintegration tests are of less value than dissolution techniques employed in the present investigation may be useful for selection of appropriate physicochemical tests for continued monitoring of the bioavailability of erythromycin stearate tablets.

Biological Availability↗
PubMed1979

Effects of post-mortem storage on synaptic 5-HT binding and uptake in mammalian brain.

Synaptosomes and synaptic membranes were isolated from rat brain after various storage times and temperatures of the tissue. Synaptosomal 5-HT uptake was diminished by about 20% within the first hour after decapitation. No significant change in the incorporation rate was observed for the seven proceeding hours if the brains were stored at room temperature. After an initial decrease of about 15%, 5-HT incorporation remained constant for at least 24 hours if the tissue was stored at 4 degrees C. Electron micrographs showed that nerve endings were highly disrupted by freezing and thawing of the brains.--The capacity of high affinity 5-HT binding to the microsomal synaptic membrane fraction decreased with the first hour by about 13% to 120--130 fmoles 5-HT/mg protein and remained almost constant for the next eight hours. Freezing at --80 degrees C of whole brain or of isolated membranes did not affect 5-HT receptor interaction.--The capacity of specific 5-HT binding to membranes isolated from human post-mortem brain was comparable to that found with synaptic membranes from rat brain. In contrast to the control values, a significant decrease in 5-HT binding was observed in membrane fractions isolated from brain after cerebral insult.

Animals↗
PubMed1979

The effect of sulfinpyrazone on morphological changes in the coronary vasculature induced by prolonged unpredictable stress in the rat.

It was confirmed that prolonged unpredictable stress in the rat induces morphological change in the coronary microcirculation. These changes include dilation in venules, deposits staining positive with PAS in the venules due to platelet aggregation and a breakdown of the endothelial lining in arterioles. Sulfinpyrazone is reported to prevent platelet agglutination, and shows effectiveness in the clinic in preventing re-infarction following infarction. Accordingly rats were exposed to the stress regimen for 50 days, and groups were treated with sulfinpyrazone, either prophylactically (receive drug for 50 days) or therapeutically (receive drug Day 30 to Day 50). The morphology of the hearts of treated animals were compared with those of placebo treated controls. It was demonstrated that therapeutic sulfinpyrazone did not prevent (p less than 0.01), but reduced the incidence of morphological change in the coronary microcirculation. Prophylactic sulfinpyrazone had a distinct protective effect (p less than 0.001). It was demonstrated that the plasma corticosterone levels in both drug groups did not fall to the level found in control groups. The results are discussed in terms of a glucocorticoid-sulfinpyrazone interaction preventing prostaglandin release which will prevent platelet aggregation. It is possible that the interaction relates to maintaining the integrity of the microcirculatory endothelial cells, thus preventing the local release of inflammatory substances.

Animals↗
PubMed1979

Urinary sodium and blood pressure in vegetarians.

Urinary sodium, potassium urea, creatinine, uric acid, plasma urea, creatinine, cholesterol, blood pressures, height, weight, and skinfold thickness were measured in some or all of 106 matched pairs of vegetarians (mainly Seventh-Day Adventists) and nonvegetarians. Mean blood pressures were lower in vegetarians (141.9/88.9 mm) than nonvegeterians (148.0/90.9 mm) but the urinary excretion of sodium was higher, although not significantly, in the vegetarians (mean of 169.7 compared with 161.2 mmole/day). The vegetarians also had a higher urinary potassium excretion (62.9 mmole/day) than the nonvegetarians (54.8 mmole/day) thus giving them a lower mean sodium to potassium ratio (3.0 compared with 3.3). Both systolic and diastolic blood pressures correlated positively with plasma cholesterol levels which were less in vegetarians (6.0 mmole/liter) than nonvegetarians (6.6 mmole/liter). They also correlated positively with the urinary sodium to potassium ratio, but only in nonvegetarians. It was concluded that dietary sodium does not explain the blood pressure differences between vegetarians and nonvegetarians.

Adolescent↗
PubMed1979

Intraembryonic origin of lymphoid stem cells in the chicken: studies with sex chromosome and IgG allotype markers in histocompatible yolk sac-embryo chimaeras.

Two-day-old chick embryonic bodies were transplanted onto the area vasculosa of age-matched histocompatible blastoderms, resulting in the development of yolk sac-embryo chimaeras. Eighteen of these succeeded in hatching and became adults. Differences in the sex chromosomes and in IgG allotype between the embryo and the yolk sac were used to study the contribution of these two components to the lymphoid cell development. At 5-7 weeks of age the chimaeras proved to be completely normal in the IgM and IgG antibody production against human gamma globulin and Brucella abortus and in the lymphocyte responses to phytohaemagglutinin and concanavalin A. For the sex chromosome analyses bursa cells and specifically stimulated B and T lymphocytes were used. The latter was achieved by stimulating thymus, spleen, and bone marrow cells in vitro with anti-Ig and Con A. Only four out of 1498 mitoses analysed belonged to the sex opposite to that of the bird. Among the chimaeras eleven were marked through IgG allotypes. At the age of 3-20 weeks all eleven chimaeras showed serum IgG of the embryo allotype and none of the yolk sac type. These results, based on the use of two different markers, indicate that lymphoid stem cells in the chicken are originally derived from an intraembryonic source and not from the yolk sac.

Animals↗