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Biomedical subjects

F L Carson

Publications and source records attributed to F L Carson.

7 recordsLinked to original sources
PubMed1989

Small intestinal morphology in experimental diabetic rats: a stereological study on the effects of an aldose reductase inhibitor (ponalrestat) given with or without conventional insulin therapy.

The gross and microscopical dimensions of small intestines from 12-week old streptozotocin-diabetic rats receiving no therapeutic intervention were compared with those from animals receiving insulin alone or in conjunction with the aldose reductase inhibitor, ponalrestat. Four regions along each intestine were analysed stereologically. Insulin had significant beneficial effects on body weight as well as on intestinal length, width, surface area and volume. In contrast, ponalrestat did not improve body weight deficits and was associated with crypt hypertrophy and a reduced villous surface/crypt volume ratio. There were interaction effects between insulin and ponalrestat for intestinal length and primary mucosal surface area. All groups displayed significant regional differences in surface area of primary mucosa and volume of muscularis externa. Only untreated diabetic rats failed to reveal regional variation in the surface area and volume of villi. Ratios of villous surface area/crypt volume varied from region-to-region in insulin-treated diabetic rats but not in other groups. The study fails to reveal any beneficial effect of aldose reductase inhibition on the changes in intestinal morphology seen in experimental diabetes.

Analysis of Variance↗
PubMed1989

Mechanisms of adaptation in rat small intestine: regional differences in quantitative morphology during normal growth and experimental hypertrophy.

The gross and microscopical dimensions of small intestines from three groups of rats were investigated by morphometric (mainly stereological) methods. The groups were chosen to represent relatively 'steady state' situations: normal growth (over a 12 week period) and intestinal hyperplasia due to streptozotocin-diabetes of 12 weeks duration. Four intestinal segments were sampled along each intestine. For normal groups, no interaction effects were found, suggesting that growth affected all regions of the small intestine in the same way. Older rats were heavier and their intestines were longer and narrower. In addition, villous surface area was more extensive and the villi differed in shape. Volumes of crypts, submucosa and muscularis externa were all reduced. Diabetic animals weighed less than age-matched controls and their intestines were wider but not significantly longer. All surface areas and volumes were increased substantially. However, hypertrophy of the muscularis externa was not detected by measuring muscularis thickness. Villi altered their shape. At least for villous height, the effects of diabetes were greater in terminal segments. These findings are discussed in the context of the reported effects of age and experimental hyperplasia (including diabetes) on intestinal architecture and behaviour.

Adaptation, Physiological↗
PubMed1978

Calcium localization in normal rachitic, and D3-treated chicken epiphyseal chondrocytes utilizing potassium pyroantimonate-osmium tetroxide.

Normal, rachitic, and vitamin D3-replete chicken growth plates were studied utilizing the potassium pyroantimonate-osmium tetroxide procedure. A marked membrane and mitochondrial calcium was revealed in all specimens in the maturing and early hypertrophic zones which disappeared as heavy matrix mineralization began. The most significant difference shown in the specimens was in the marked intracellular lipid content of chondrocytes in all zones of the rachitic and D3-replete growth plates. There was negligible lipid present in normal specimens. It is suggested that as most of the mechanisms postulated as necessary for calcification are present in rachitic chicks, perhaps the increased intracellular lipid pool results from the formation of abnormal lipids for insertion into the plasma membrane and thus prevents normal calcium transport. Chains of intracellular vesicles were also visualized in maturing and hypertrophic chondrocytes. These were more often seen in rachitic growth plates and in increased numbers in the early D3-replete specimens. The etiology is unknown at the present time.

Animals↗