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Biomedical subjects

D C Bennett

Publications and source records attributed to D C Bennett.

79 records · Page 5Linked to original sources
PubMed1979

Vitellogenesis stimulated by thoracic ganglion implants into destalked immature spider crabs, Libinia emarginata.

Since destalked immature female Libinia emarginata fail to molt to maturity (Hinsch, 1972) and implants of thoracic ganglion of adult females into young females of Potamon dehaani caused a doubling of ovarian weight and differentiation of yolk granules (Otsu, 1963), the effects of the thoracic ganglion implantation on sexual maturation in Libinia was investigated. Destalked immature Libinia with a maximum carapace length of 4-5 cm received two implants of adult female thoracic ganglion at 10-day intervals. All of the surviving experimental animals and destalked controls molted to immaturity. Most of the experimental animals failed to complete a successful molt and few survived longer than 3-4 days. The experimental animals that survived for over a week showed signs of yolk deposition not observed in the destalked controls. Eggs in several stages of vitellogenesis were scattered throughout the gonad in the animal showing the most pronounced effect. This was not observed in any of the destalked controls.

Animals↗
PubMed1978

A possible mammary stem cell line.

The cell line Rama 25 is derived from a mammary tumor induced in a rat by dimethylbenzanthracene. During rapid proliferation, Rama 25 cells appear as a single undifferentiated epithelial type; at high cell densities, however, small numbers of two other cell types are formed, which respectively resemble secretory and myoepithelial cells of the mammary gland, as judged by light and electron microscopy and immunofluorescent staining for casein (milk proteins). These additional cell types cannot be explained as contaminating cell populations since the cell line has been cloned several times; furthermore, the proportion of either can be increased by dimethylsulphoxide under different conditions. Specific epithelial features are seen by histological and ultrastructural examination of tumors formed by Rama 25 cells in immunodeficient mice. A line of the myoepithelial-like cells, Rama 29, isolated from a Rama 25 culture by cloning, is also described. We propose that the undifferentiated cell type is a form of mammary stem cell which can differentiate in culture.

Adipose Tissue↗
PubMedDate not supplied

Suspected sodium toxicity in hand-reared great blue heron (Ardea herodias) chicks.

Sodium toxicity was suspected in hand-reared great blue heron (Ardea herodias) chicks fed herring frozen in brine (seawater). Affected chicks were lethargic with stiff legs that extended to the posterior, and breathing was labored. Chicks regurgitated food or refused to eat. All chicks that were fed herring exclusively and eight of the 10 chicks fed a mixed diet (herring and salmonids) died, whereas all chicks fed only salmonids survived. Renal lesions ranged from mild to marked generalized nephrosis, which was characterized by degeneration and necrosis of the proximal convoluted tubular epithelium and dilation of the distal convoluted tubules and collecting ducts. These observations suggest that fish frozen in brine is unsuitable food for hand-rearing of young herons.

Animal Feed↗