Search PubMed⌕ Search

Biomedical subjects

R Cohen

Publications and source records attributed to R Cohen.

At least 505 records · Page 28Linked to original sources
PubMed1983

Spatial representations of young children: the role of self- versus adult-directed movement and viewing.

The influence of the control of movement and viewing while exploring a novel large-scale environment was assessed. Forty kindergarteners and forty second grade children served in four activity conditions that represented the factorial combination of movement (self vs adult directed) and viewing (self vs adult directed). A significant grade level X movement X viewing interaction revealed that when kindergarteners directed their own movement, estimates of interlocation distances were equivalent whether viewing was self or adult directed. If movement was directed by an adult, kindergarteners estimated interlocation distances more accurately if the adult also directed their viewing than if the children directed their own viewing. Second grade children performed comparably across all four experimental conditions.

Attention↗
PubMed1983

A programme in undergraduate geriatric education: the Beer Sheva experiment.

The Beer Sheva medical school was started in 1974 with the objective of training primary care doctors to meet the health needs of the Negev region of Israel. This paper describes a programme developed at Beer Sheva to prepare students to deal with the health-related problems of the elderly. Students begin their contact with the elderly in their first year (early clinical teaching programme) and continue this exposure in varying degrees during the 6 year curriculum. A preliminary study has shown that there is a trend for students to commence their studies with positive attitudes toward the elderly. The early clinical teaching programme which emphasizes interviewing skills, knowledge about ageing and community services that relate to the aged, reinforces the student's sensitivity to geriatric issues. In order to maintain the student's interest in working with the elderly, it is apparent that it will be necessary to educate both hospital and community-based physicians to provide positive role models for students.

Attitude of Health Personnel↗
PubMed1983

Splenic regeneration following splenectomy for traumatic rupture.

Thirty-three patients previously splenectomized following traumatic rupture of the spleen were assessed using a radionuclide technique. Splenic tissue was detected by this means in 22 patients (67%). Peripheral venous blood was examined for the presence of erythrocyte surface vacuoles. Vacuolated red blood cells were detected more frequently than in the normal population. The incidence of vacuolated red blood cells was inversely related to the estimated volume of regenerated splenic tissue.

Adolescent↗
PubMed1983

Autonomic reactivity in the premenstrual phase.

The aim of the present experiment was to determine the effects of the premenstrual cycle phase on autonomic arousal. In a repeated measurement study 40 female subjects were tested premenstrually and postmenstrually for their autonomic reactivity during stress (cold pressor test, mental arithmetic) and for their acquisition of conditioned electrodermal responses, using a standardized auditory conditioning procedure. None of the differences between the cycle phases were significant. Similar results were obtained in the subjects' answers in a mood adjective list and their stimulus ratings. There was a general decrease in autonomic reactivity from the first to the second recording session, independent of the menstrual cycle periods.

Adolescent↗
PubMed1983

Virus-host cell interaction in rat C6 glial cell cultures persistently infected with herpes simplex virus.

The virus-host cell interaction in a rat C6 glial cell line persistently infected with herpes simplex virus type 1 (HSV1) was examined. The C6 cultures infected at an MOI of 10 or 0.01 exhibited virally induced cytopathology and produced infectious virus and viral antigens for 108 and 50 days, respectively. Infectious virus was continually present in the supernatant fluids of persistently infected cultures, with only a minority of the cells having viral CPE or viral antigens at any given time. There was no obvious pattern of periodic cyclical viral replication in these cultures; no predictable regularity in the fluctuations of virus production was evident. 'Cured' cultures were as susceptible to re-infection with HSV1 as previously uninfected cultures; thus, there was no selection of a subpopulation of C6 cells resistant to subsequent challenge with HSV1. The virus recovered from persistently infected cultures was more infectious for C6 cells relative to HeLa cells than was the original virus stock. Significant levels of interferon were not detected in HSV1-infected C6 cultures during either the acute or persistent phases of infection or in 'cured' cultures.

Animals↗
PubMed1983

Hormonal and metabolic effects of near physiological increase of plasma immunoreactive somatostatin 14.

The possibility that somatostatin 14 (SRIF) may exert true endocrine actions in man was tested by investigating the hormonal and metabolic effects of the peptide infused for 80 min at rates of 36.5, 73, and 146 pmol kg-1 h-1 in six healthy subjects who fasted overnight. These three doses increased the level of plasma SRIF-like immunoreactivity in the range of concentrations recorded postprandially with the same assay system. These low SRIF infusion rates decreased insulinemia and to a lesser extent glucagonemia, and increased glucosemia and ketonemia. Both the reduction of insulin and the increase of glucosemia were significantly related to the increase of plasma SRIF-like immunoreactivity. All parameters returned to control values upon discontinuing the peptide infusion. This study suggests that SRIF may have an endocrine role in man and that such low dose, short time SRIF infusions could exert metabolic effects different from those of larger, probably pharmacological, infusion rates.

Adult↗
PubMed1983

Role of catecholamines in the ketonemic response to somatostatin in normal man.

In order to determine if a rise of circulating catecholamines occurs during somatostatin (SRIF) infusion in normal man, and if this increase plays a significant metabolic role, we infused four normal subjects with SRIF (500 micrograms/h) alone or associated with either alpha-(phentolamine) or beta-(propranolol) adrenergic blocking agents. During SRIF infusion, the initial small decrease in blood glucose was followed by a rise of epinephrine from 25-46 ng/liter (range) to 117-143 ng/liter (range) (P less than 0.05) at 80 min and norepinephrine from 204 +/- 16 to 418 +/- 60 ng/liter at 90 min (P less than 0.05). Thereafter, plasma nonesterified fatty acids, blood glycerol, and ketone bodies increased significantly. Phentolamine adjunction modified neither the catecholamines rise, nor the metabolic changes. Propranolol adjunction did not modify the glucose fall and the catecholamine rise, but resulted in blunted increments of fatty acids and glycerol and in an almost complete suppression of the increase of ketone bodies. These results suggest that the enhanced lipolysis and ketogenesis observed during SRIF infusion are not only due to the SRIF-induced insulin deficiency but also in part to a beta-receptor mediated effect of catecholamines.

Adult↗
PubMed1983

Is the period of rapidly declining adult mortality in the United States coming to an end?

Age-standardized death rates from all causes for persons age 35-74 fell 23 per cent, 1968-1979. The monotonic decline was interrupted by only one period of excess influenza mortality. In the late 1970s, however, the decline in mortality decelerated and no further decrease was observed, 1979-1981. The recurrence of epidemic influenza contributed significantly to this trend although it would appear that the underlying mortality pattern has begun to change.

Adult↗
PubMed1983

Regulation of ketonaemia in hyperthyroidism: study of the role of free fatty acids.

We have indirectly assessed the role of free fatty acids (FFA) and of hepatic ketogenesis in the regulation of ketone body levels in euthyroid and hyperthyroid subjects. All studies were performed under controlled dietary conditions (35 and 45 kcal/kg body weight/day respectively for euthyroid and hyperthyroid subjects). In the post-absorptive state hyperthyroid patients had normal, glucagon levels and, in spite of increased insulinemia (p less than 0.02), elevated concentrations of blood glucose (p less than 0.01), glycerol (p less than 0.001) and ketone bodies (p less than 0.05). In the face of this hyperketonaemia, there was no significant increase of plasma FFA, suggesting possible increased hepatic conversion of FFA to ketone bodies. However, when FFA were acutely raised to high levels, the induced rise of ketone bodies was similar in hyperthyroid and euthyroid subjects. Oral propranolol administration to hyperthyroid patients in the post-absorptive state decreased the concentrations of glycerol (p less than 0.05) and ketone bodies (p less than 0.05) without altering insulin concentrations. Ketone bodies fell without any significant decrease of FFA suggesting a possible direct effect of propranolol administration on hepatic ketogenesis. However, the ketone body response to raised FFA levels was unaffected by propranolol. We have evidence in hyperthyroid patients of increased lipolysis and ketogenesis in spite of increased daily caloric intake. These results suggest that these metabolic abnormalities are not merely due to relative starvation. We have tentative evidence for modification of the intra-hepatic conversion of FFA to ketone bodies in the post-absorptive state but no supporting evidence when FFA levels were experimentally raised.

Adult↗
PubMed1983

[Somatocrinin induces growth hormone release in a case of growth hormone deficiency of hypothalamic origin in a child].

Somatocrinin (hp-GRF-44), a growth hormone releasing factor, stimulates acute pituitary response in a 11 years and 4 months old boy, with growth hormone deficiency. The capability of the anterior pituitary to secrete growth hormone in response to an IV injection of somatocrinin (120 micrograms 4 micrograms/kg) was documented, therefore proving the hypothalamic origin of the deficit which had been suspected because of association of diabetes insipidus and hyperprolactinemia.

Child↗
PubMed1983

[Acromegaly, clinical expression of the production of growth hormone releasing factor in pancreatic tumors].

In exceptional cases, acromegaly develops as the clinical expression of an ectopic secretion of Growth Hormone (GH) or Growth Hormone-Releasing Factor (GRF), tumorous in origin. In the present report, we describe an instance of acromegaly caused by the secretion of GRF from a voluminous pancreatic tumor. The resection of this tumor resulted in a temporary disappearance of the biological and clinical symptoms of acromegaly, which then reappeared in conjunction with a rise in plasma GRF. From this pancreatic tumor, substances displaying a potent GRF activity were isolated and characterized. Amino acid analyses revealed that they were related to 3 peptides containing respectively 44, 40 and 37 aminoacids. The largest (hp GRF (1-44)-NH2) referred as hp GRF or somatocrinin is considered to be the primary molecule. The pancreatic tumor was multisecreting as proved by high plasma levels of somatostatin, pancreatic polypeptide and glucagon, normalized after the tumor removal, taken together with the immunocytochemical demonstration of the presence of these peptides in the tissue and with the isolation of somatostatin. In contrast hypercalcemia associated with an elevated plasma level of IR-PTH was unmodified by tumor removal. Diagnosis of acromegaly as ectopic endocrine syndrome will probably be facilitated by plasma GRF radioimmunoassay, as a result of production of anti synthetic GRF antibodies.

Acromegaly↗