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Biomedical subjects

C E Smith

Publications and source records attributed to C E Smith.

16 recordsLinked to original sources
PubMed1979

Stress-induced cortisol release in hypothalamic hypoadrenalism.

A 52-year-old woman experienced hypoadrenalism (mean 8 AM plasma cortisol level, 3.7 microgram/dL) after hypothalamic surgery and radiotherapy for craniopharyngioma. Despite low plasma adrenocorticotropic hormone levels (less than 25 pg/mL), absent diurnal variation of the plasma cortisol level, and subnormal urinary 17-hydroxycorticosteroid response to metyrapone, she had normal plasma cortisol responses to insulin-induced hypoglycemia and to administration of vasopressin or synthetic adrenocorticotropic hormone. Stress-induced cortical release may be preserved despite notable abnormalities in regulation of cortisol secretion by diurnal and feedback-mediated mechanisms.

17-Hydroxycorticosteroids↗
PubMed1979

Potential antiinflammatory compounds. 3. Compounds derived from acenaphthene and indan.

Compounds having acenaphthene and indan as their parent nuclei were synthesized for antiinflammatory testing. Compounds which showed activity were 1-phenyl-5-acenaphthenylacetic acid and its alpha-methyl derivative (carrageenan rat paw edema) and the same alpha-methylacenaphthenylacetic acid and 2-(4-chlorobenzylidene)-3-oxo-5-indanacetic acid and its alpha-methyl derivative (rat adjuvant arthritis). None of the compounds was more active than the control compounds phenylbutazone and indomethacin.

Acenaphthenes↗
PubMed1979

Ameloblasts: secretory and resorptive functions.

The sequence of steps which an ameloblast passes through in forming enamel appears remarkably similar in amphibian and man. Despite considerable improvements in understanding the early events in the life cycle that lead to the intracellular synthesis and secretion of enamel matrix by the cell, little is known about the cell's functional role at later stages of the life cycle when the extracellular enamel matrix undergoes classical maturation in becoming fully mineralized.

Ameloblasts↗
PubMed1979

Hydrocortisone and the antibody response in mice. II. Correlations between serum and antibody and PFC in thymus, spleen, marrow and lymph nodes.

The discovery that corticosteroids can alter leucocyte distribution implies that suppression of PFC in the spleen is not necessarily indicative of suppression of the antibody response as a whole. Therefore we have examined IgM and IgG serum antibodies and PFC in the thymus, spleen, femoral marrow, popliteal, thoracic and mesenteric lymph nodes of mice given a single injection of hydrocortisone acetate at various times relative to primary immunization with SRBC. Contrary to certain reports, there was close correlation between suppression of serum antibody and of splenic PFC, from which it was predicted and verified that few PFC could be detected elsewhere. In our hands, therefore, splenic PFC measurements did give an accurate indication of suppression overall. The characteristics of suppression suggest some of the underlying causes, and these are discussed.

Animals↗
PubMed1979

Hydrocortisone and the antibody response in mice. I. Correlations between serum cortisol levels and cell numbers in thymus, spleen, marrow and lymph nodes.

Mice injected with a single well tolerated dose of hydrocortisone acetate were observed over 2--3 weeks for serum cortisol levels and for cell depletion in thymus, spleen, femoral marrow, mesenteric, inguinal and popliteal lymph nodes. Serum cortisol peaked within 24 h and declined to normal after 4 days. Total marrow cell numbers were relatively unaffected, but in all other tissues studied, cell depletion was severe and prolonged. B lymphocytes were affected more severely than T lymphocytes. There was a transient increase in the percentage of marrow T lymphocytes but otherwise little change. The percentage of node T lymphocytes increased while that of B lymphocytes decreased. The percentage of spleen B lymphocytes was reduced severely but transiently during the period of serum cortisol elevation. Spleen T lymphocyte percentages rose steadily between the fourth and seventh days after treatment, then returned to normal. Representatives of most types of lymphoid tissue were studied. As cell losses in any one were not compensated by gains in any other, most were probably due to destruction rather than redistribution. The slow rates of recovery were also more consistent with regeneration than with reappearance after redistribution.

Animals↗
PubMed1977

Inorganic trimetaphosphatase as a histochemical marker for lysosomes in light and electron microscopy.

A new cytochemical method is presented for the light and electron microscopic localization of lysosomes in mineralized and soft tissues. Inorganic trimetaphosphate is used as substrate in a lead chelate incubation medium at pH 3.9. Lysosomes in several tissues are strongly reactive, and reaction product is frequently present in Golgi saccules and GERL. The reaction can be differentiated from acid glycerophosphatase activity, is relatively insensitive to fixation and demineralization procedures, and the reaction is often complete after short incubation times.

Animals↗
PubMed1975

The significance of mosquito longevity and blood-feeding behaviour in the dynamics of arbovirus infections.

Mosquito longevity and blood-feeding behaviour are very important but neglected factors in the dynamics of arbovirus infections as changes in them affect transmission rates exponentially. Some mosquito species feed on a narrow range of vertebrates, some on a wide range, both influenced by host-availability and other environmental and behavioural factors. Only those which feed on maintenance hosts contribute to maintenance of the infection. Some species change their feeding pattern with season. The frequency of blood-feeding depends inter alia on environmental temperature. Longevity is perhaps most important: the majority of mosquitoes infected probably do not survive long enough to become infective; it is influenced by relative humidity, temperature and predation. Longevity, feeding frequency and the extrinsic incubation period are all temperature dependent and are therefore important rate determinants in seasonal epizootics or epidemics. Equally, their relative stability in the tropics contributes to the equilibrium of an enzootic or endemic.

Aedes↗