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Biomedical subjects

I Levy

Publications and source records attributed to I Levy.

At least 109 records · Page 6Linked to original sources

Cellular immune aspects of the human fetal-maternal relationship.

In the present study the number and the function of T lymphocytes obtained from peripheral blood of 35 mothers immediately after delivery and from the cord blood of the respective newborns were tested. Furthermore, the effect of the newborns' lymphocytes on the immunological competence of the mothers' lymphocytes was investigated by means of graft-versus-host-reaction xenograft test. The blood of 14 of the mothers and their newborns was also examined by monoclonal antibodies for determination of T helper and T suppressor lymphocytes. A marked reduction in the absolute number of T helper cells was found in the blood of mothers after delivery. In addition, mothers' lymphocytes manifested a high suppressor activity when added to normal human lymphocytes. It was also found that the cord blood contains lower number and percentage of T suppressor cells. Yet the T cells of the cord blood exert a high suppressor activity on the mother as well as on normal donor lymphocytes. The impaired function of cord blood lymphocytes could be impaired function of cord blood lymphocytes could be restored by in vitro addition of THF, a thymic hormone.

Female↗

Somatostatin and counterregulatory hormone responses to hypoglycaemia in diabetics with and without autonomic neuropathy.

Blood glucose, somatostatin and counterregulatory hormone responses to an i.v. bolus of insulin were studied in insulin-dependent diabetics with different degrees of autonomic neuropathy, after 24 hours of optimised control with an artificial pancreas. There was no plasma catecholamine response in patients with a sympathetic autonomic neuropathy. A normal somatostatin response to hypoglycemia was absent in patients with autonomic neuropathy. Glucagon did not respond in diabetics, independently of the degree of neuropathy. In all diabetics, cortisol and GH were stimulated. Absence of warning symptoms was observed in patients with catecholamine deficiency. Despite different hormone behaviour, blood glucose fall and recovery were similar in all diabetic groups. It is concluded that the glucagon response to insulin hypoglycaemia is reduced in all type 1 longstanding diabetics, whereas catecholamine and somatostatin responses are only abolished in those with autonomic neuropathy. Patients with sympathetic neuropathy would be considered at increased risk severe hypoglycaemia.

Adult↗

Studies on the mechanisms of somatostatin release after insulin induced hypoglycaemia in man.

Insulin-induced hypoglycaemia, which stimulates gastric acid secretion, is associated with an increase in circulating somatostatin levels in man. In order to assess the mechanisms involved in this rise, six normal volunteers connected to a Biostator for continuous glucose monitoring were studied, on three separate occasions. On each occasion after basal blood sampling, 0.15 i.u./kg body weight of insulin was administered i.v. and further samples were obtained intermittently over 150 min. On one occasion, dextrose was infused by the Biostator to prevent hypoglycaemia, while on the other two, a constant infusion of either normal saline or the specific H2 antagonist cimetidine was administered. Insulin plus dextrose caused no significant changes in circulating somatostatin levels, whereas insulin plus saline was associated with a marked, sustained and significant rise in all subjects; insulin plus cimetidine also produced a rise but it was delayed; the area under the curve was significantly (P less than 0.05) greater with insulin plus saline than with insulin plus cimetidine. These results show that in man insulin itself does not stimulate somatostatin secretion directly, but indirectly via hypoglycaemia. Further, the inhibition of gastric acid secretion with cimetidine reduces somatostatin release during insulin-induced hypoglycaemia. This suggests that gastric acid may mediate somatostatin secretion associated with insulin-induced hypoglycaemia.

Adult↗

Herpes encephalitis and herpetic corneal disease.

A case of herpes encephalitis is reported in a patient who had cranial irradiation and high dose steroids for a cerebral neoplasm. Before radiotherapy the patient had had herpetic infections of the skin and eye.

Brain Neoplasms↗

Vision in the temporal crescent in occipital infarction.

Four patients with hemianopias due to occipital infarction are described. In each of these patients there was useful residual vision in the unpaired temporal crescent. Moving stimuli were particularly well perceived in this part of the field. Preservation of the temporal crescent results in strikingly incongruous fields. The significance of this part of the visual field is discussed in relation to perception of movement and to the fixation reflex, and also with regard to recent reports of residual visual ability in patients with striate cortex lesions, and to the possible role of the monocular temporal field in striate and tectal visual systems.

Cerebral Infarction↗

Figural symbolism in Chinese ideographs.

Hebrew-speaking subjects were presented with 42 pairs of Chinese characters designating antonymic concepts and were required to match them with their corresponding Hebrew words. Correct translation was significant and was related to foreign language study and academic experience. Highest success was found for the activity domain of the semantic differential and for attributes judged to afford a diagrammatic representation. Examination of the character-referent relationships suggested that translation success was due to principles of figural symbolism rather than to pictographic representation of the attributes in question. The results are seen as suggestive of the effects of figural symbolization on the invention and/or evolution of natural scripts and are discussed in terms of the manner in which the graphic medium has been fashioned to convey abstract concepts.

Adolescent↗