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Biomedical subjects

C R Taylor

Publications and source records attributed to C R Taylor.

At least 397 records · Page 22Linked to original sources

A comparison of sweat gland activity in eight species of East African bovids.

1. The pattern and control of the sweat glands of eight species of wild bovids has been studied.2. Heat exposure resulted in changes in cutaneous moisture loss which showed considerable species variation. Duiker, Grant's gazelle, Thomson's gazelle and oryx all demonstrated periodic discharges of moisture on to the surface of the skin. Defassa waterbuck and eland exhibited discharges which were accompanied by a gradual rise in basal level. Buffalo showed an immediate large increase which was sustained during the period of heat exposure. Three wildebeest displayed small fluctuations whilst a fourth animal showed a step-wise increment in cutaneous moisture loss.3. The intravenous infusion of adrenaline into the buffalo and one wildebeest caused an increase in cutaneous moisture loss, the magnitude of which was directly related to the size of the dose administered. In three other wildebeest, and all other animals tested, a single injection of adrenaline was necessary to cause a discharge of moisture on to the surface of the skin. Noradrenaline was without effect.4. Heat-induced but not adrenaline-induced sweating was inhibited by the intravenous administration of an adrenergic neurone blocking agent, bethanidine.5. It is concluded that the sweat glands of the wild bovids studied are under adrenergic neurone control, in common with the domestic bovids previously studied, and that there is no correlation between the pattern of sweating and the phylogenetic position of the species.

Animals↗

Sweat gland function of the donkey (Equus asinus).

1. Donkeys sweat on exposure to heat and in response to intravenous adrenaline infusion.2. Thermal sweating was abolished by the adrenergic-neurone blocking agent bethanidine but not by atropine.3. Sympathetic decentralization (by preganglionic sympathectomy) abolished thermal sweating but adreno-medullary denervation had no effect.4. Exercise resulted in sweating from both sympathetically innervated and decentralized skin and from the innervated skin of animals which had previously undergone adreno-medullary denervation.5. Insulin-induced hypoglycaemia resulted in sweating from sympathetically decentralized skin and from innervated skin in two out of four animals. Adreno-medullary denervation abolished the sweat gland response to insulin administration.6. Cold exposure inhibited the response of innervated sweat glands but not that of decentralized glands to adrenaline infusion.7. It was concluded that heat-induced and exercise-induced sweating of the donkey is controlled by adrenergic nerves; adreno-medullary secretion may contribute to sweating during exercise, and that cutaneous blood flow is important in the response of the glands to humoral stimulation.

Adrenal Medulla↗

Red blood cells: why or why not?

It is commonly stated that, if hemoglobin were dissolved in the blood plasma rather than enclosed in corpuscles, the viscosity of the blood would be greatly increased. We found that when the corpuscles of dog or goat blood were disrupted with ultrasound, giving a solution with the same hemoglobin concentration, the relative viscosity was drastically reduced. It appears, therefore, that the existence of blood corpuscles does not contribute to a reduced viscosity of blood.

Animals↗

Hairy cell leukemia has a B-cell genotype.

The phenotype and, by inference, the cell of origin of some lymphocytic neoplasms has been defined by surface marker studies; however, the precise cellular origin of other neoplasms of the lymphoid system is still unknown. For example, with reference to hairy cell leukemia (HCL), cell marker data has been used in support of a monocytic, a T cell, or a B cell origin. If hairy cell leukemia is a B cell-derived neoplasm, the controversy may be resolved by genotyping the cells, using the rearrangement of immunoglobulin genes as a marker of the B cell nature of the process. Rearrangement of these genes is detected using the Southern blot technique and cloned probes specific for the JH segment of the immunoglobulin genes. In this study, the arrangement of the immunoglobulin genes was analysed in normal tissue, in two accepted B cell lymphomas and in nine cases of hairy cell leukemia. DNA from peripheral blood leukocytes (two patients) and from the spleen (seven patients) revealed a discrete new JH restriction fragment length in the leukocytes of hairy cell leukemia cases. The presence of rearranged restriction fragments is interpreted as evidence of the existence of clonal B cell populations. Three of six samples had rearranged kappa light chain fragments. We conclude that most cases of hairy cell leukemia have a B cell genotype. The use of genotyping has wider application in the analysis of hematological malignancies.

B-Lymphocytes↗

An immunopathologic evaluation of lymph nodes from monkey and man with acquired immune deficiency syndrome and related conditions.

Morphology and immunostaining of lymph nodes taken from rhesus monkeys and man are compared. The monkeys were inoculated with biologic materials known to transmit simian acquired immune deficiency syndrome (SAIDS) and the human biopsies were obtained from homosexual men with persistent generalized lymphadenopathy syndrome or acquired immune deficiency syndrome (AIDS). The lymph nodes from monkey and man share common immunohistochemical features, ranging from exhuberant follicular hyperplasia to lymphocyte depletion stage. The follicular hyperplasia differed from reactive controls by the larger follicular size and disorganization within the follicular centers as well as an increase in the number of cells with the T suppressor/cytotoxic phenotype. The lymphocyte depletion stage showed a loss of reactive follicles and small T lymphocytes with a predominance of mature monocytes/macrophages. Most monkeys and humans with the lymphocyte depletion morphology fulfilled the case definitions for AIDS and SAIDS while those with follicular hyperplasia usually had 'prodromal' findings. The simian agent is associated with alterations in lymph node morphology and immunostaining which parallel the changes seen in spontaneous human cases supporting a similar pathogenesis for AIDS and SAIDS.

Acquired Immunodeficiency Syndrome↗