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Biomedical subjects

S T Green

Publications and source records attributed to S T Green.

At least 91 records · Page 5Linked to original sources
PubMed1988

The electrophysiological properties of the parathyroid cell: results of a study employing Sprague-Dawley rats and a review of the literature.

The present work indicates that the parathyroid cell of the Sprague-Dawley rat has a resting transmembrane potential of -30.5 +/- 4.1 mV. In a review of data obtained by earlier studies using other species, it was clear that in general the parathyroid cell transmembrane potential lies between -20 mV and -45 mV, that the transmembrane K+ concentration gradient is the principal factor in determining the magnitude of the membrane potential in the resting state, and that in most species a reduction in the extracellular Ca++ leads to cellular hyperpolarization. Detailed data on cellular input resistance in intact parathyroid tissue is not as yet available; however, indirect evidence exists that direct communication of the type described between other gland cells is present between parathyroid cells, a phenomenon which allows the passage of current to flow between adjacent cells via specialised connecting structures such as gap junctions.

Animals↗
PubMed1987

Vasoactive intestinal polypeptide does not affect thyroid follicular cell membrane potential or input resistance.

It has been suggested that vasoactive intestinal polypeptide (VIP) has a role as a neurotransmitter and that it participates in the control of hormone release from thyroid follicles. Many hormones and neurotransmitters alter the ionic permeability properties of the plasma membrane of their target cells when they bind to their receptors. Concentrations of VIP able to elicit complex time-dependent changes in rat thyroidal cyclic nucleotide levels did not affect follicular cell membrane potential or input resistance. The suggestion is made that the findings may indicate that Ca2+ is not involved in the initial stages of stimulus-secretion coupling following VIP binding to its receptor on the follicular cell.

Animals↗
PubMed1987

The electrophysiological properties of the resting thyroid follicular cell.

Glass microelectrodes have been useful in the study of the electrical properties of the resting thyroid follicular cell membrane. The resting transmembrane potential (RMP) has probably been underestimated in earlier work, possible as a result of leak artefacts, and it is clear that in most species the RMP is certainly greater than -60 mV. The ratio of membrane Na+ permeability to K+ permeability (PNa/PK) is of the order of 0.07 to 0.08, and Cl- is possibly (although not definitely) distributed in a passive fashion across the cell membrane, indicating that the transmembrane K+ gradient is the most important factor in the generation of the RMP. The existence of an electrogenic sodium pump in the follicular cell membrane has been demonstrated: the pump contributes about -2 mV to the RMP under control conditions. Follicular cells are completely electrically coupled, the basic coupled cellular unit probably being equivalent to the individual thyroid follicle, and the specific membrane resistance and specific membrane capacitance have been calculated to be 5 k omega. cm2 and 3.6 microF/cm2 respectively.

Animals↗
PubMed1987

Shot in the neck in Spain (a rare cause of an isolated Horner's syndrome).

Horner's syndrome is rare. A bullet wound in the neck is a rare cause of the syndrome, and it is exceedingly uncommon for a Horner's syndrome to be the sole noteworthy clinical result of a gunshot wound of this part of the anatomy. Two cases of bullet injury of the neck are described wherein a permanent Horner's syndrome was the only important sequel.

Adult↗
PubMed1987

Intrathyroidal autonomic nerves can directly influence hormone release from rat thyroid follicles: a study in vitro employing electrical field stimulation and intracellular microelectrodes.

The role of the autonomic nervous system in the control of thyroxine release from the rat thyroid gland in vitro, has been investigated using electrical field stimulation as a device to induce intrathyroidal nerves to release their neurotransmitters. The effects of field stimulation on follicular cell membrane potential and input resistance have been investigated using continuous intracellular recordings from individual cells. Electrical field stimulation promotes up to an eightfold increase in throxine release from the thyroid gland in vitro. This effect is blocked by the neurotoxin, tetrodotoxin. Electrical field stimulation has no effect on follicular cell membrane potential or input resistance. This is consistent with the results of previous pharmacological experiments using this preparation. It is concluded that electrical field stimulation induces intrathyroidal nerves to release their neurotransmitters, and that the net effect of this is to cause thyroxine release from the thyroid follicles. The existence of a directly acting secretomotor innervation to the thyroid follicle is suggested.

Animals↗
PubMed1987

Alcoholic ketoacidosis: a case report.

A 43-year-old alcoholic presented in coma with ketoacidosis, after three days of nausea and feeling generally unwell, which had been preceded by a prolonged three-week period of heavy alcohol consumption with poor dietary intake. The acidosis responded rapidly to intravenous dextrose. This is the first Scottish report of a case of alcoholic ketoacidosis.

Acidosis↗
PubMed1987

Varicella and life-threatening streptococcal infection.

Four children with varicella who subsequently developed life-threatening infection with Streptococcus pyogenes are reported. The need for increased awareness of this potentially lethal complication of what is usually a benign exanthem is stressed.

Adolescent↗
PubMed1987

Non-Hodgkin's lymphoma presenting with isolated cauda equina compression.

A 50-year-old man, who had previously been well, presented with symptoms and signs of progressive cauda equina compression. This was shown to be due to an extradural lesion which on biopsy was found to be a non-Hodgkin's lymphoma of the small cell lymphocyte type. There was no evidence of lymphoma deposits elsewhere. Non-Hodgkin's lymphoma rarely affects the central nervous system except as a late feature of widely disseminated disease. This case demonstrates that isolated spinal infiltration in the absence of widespread disease can be a mode of presentation of a non-Hodgkin's lymphoma. Accordingly primary extradural non-Hodgkin's lymphoma should be considered in the differential diagnosis of spinal cord and root compression.

Cauda Equina↗