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Biomedical subjects

J M Weiss

Publications and source records attributed to J M Weiss.

At least 127 records · Page 7Linked to original sources
PubMed1981

A comparison of ornithine decarboxylases from normal and SV40-transformed 3T3 mouse fibroblasts.

Ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) has been purified from 3T3- and SV40-transformed 3T3 mouse fibroblasts by affinity chromatography, and the physicochemical properties of the two enzymes compared. Measured properties include molecular weight of the active species, subunit molecular weight and specific activity of the purified enzymes, kinetic parameters, thermostability, degradation rate in vivo and immunological cross-reactivity. Although crude extracts of the transformant possess more ornithine decarboxylase activity per mg of protein than the parent strain, there is no evidence for the appearance of an altered form of the enzyme in these cells. The results reported in the present paper indicate that the increased ornithine decarboxylase activity in the transformed cells is the result of higher enzyme biosynthesis de novo.

Animals↗
PubMed1980

Stress-induced depression of motor activity correlates with regional changes in brain norepinephrine but not in dopamine.

This experiment examined how inescapable tail shock alters the level of dopamine and norepinephrine within various brain regions of the rat and the relationship of these changes to the depression of motor activity produced by the shock. Following exposure to tail shock that is known to interfere with acquisition of active behavioral tasks, animals were briefly tested for spontaneous motor activity and then sacrificed for neurochemical measures. Norepinephrine and dopamine levels in the frontal cortex, brain stem, striatum, olfactory tubercle, hypothalamus, hippocampus, septum, and amygdala were measured by a sensitive radioenzymatic technique. Exposure to 45 min of tail shock did not alter motor activity significantly, but shock sessions of 60 and 75 min duration produced a marked decrease in motor activity. Levels of dopamine were found to be very little changed in all brain regions studied except for the hypothalamus, in which a substantial rise in dopamine level was observed. Norepinephrine levels, in contrast, fell in many brain regions in response to shock. The fall in norepinephrine levels observed in two brain regions was significantly correlated with the decline in motor activity (brain stem r = +0.70, hypothalamus r = +0.60). These data suggest that deficits in active motor behavior produced by shock parameters similar to those used in this study may reflect concomitant disturbances of noradrenergic function in specific brain regions.

Animals↗
PubMed1980

Biochemical evidence for an interaction of ethanol and stress: preliminary studies.

Studies were carried out to examine the interaction of stress and ethanol. Ethanol (0.5 g/kg)-treated, stressed (electric foot shocks) rats exhibited less marked elevations in plasma levels of nonesterified fatty acids and of corticosterone compared to saline-treated stressed subjects. Stress alone markedly elevated these two parameters in plasma. Ethanol treatment alone also resulted in small elevations in both parameters. Results provide support for a significant interaction of ethanol and stress, and might provide some basis for the purported stress-relieving effect of low doses of ethanol.

Animals↗
PubMed1978

Effect of ACTH 4-10 on passive avoidance of rats lacking vasopressin (Brattleboro strain).

The hypothesis that the effects of ACTH 4-10 on avoidance are mediated via the release of endogenous vasopressin was investigated. To test this hypothesis, we observed the effect of ACTH 4-10 on the passive avoidance of Brattleboro rats with diabetes insipidus resulting from a total genetic deficiency of vasopressin (DI) and Brattleboro rats without diabetes insipidus (HE). Normal Long-Evans rats (LE) were also included for comparison purposes. The results did not support the hypothesis. ACTH 4-10 did influence the passive avoidance of DI rats; this should not have occurred if the release of endogenous vasopressin is necessary for ACTH 4-10 to influence avoidance.

Adrenocorticotropic Hormone↗
PubMed1977

Malignant tumors of the testis: analysis of treatment results and sites and causes of failure.

A total of 150 patients with germinal testicular neoplasms treated at the University of California, San Francisco, were reviewed. The 5-year actuarial survival rate was 95% for 57 patients with seminoma and 56% for 75 patients with carcinoma. Treatment modalities were compared with respect to sites and causes of failure and complications. The most common sites of failure in the carcinoma patients were lung, and supraclavicular or mediastinal lymph nodes. Scrotal orchiectomy, elevated gonadotropins, elements of choriocarcinoma, and bulky abdominal disease were all correlated with high treatment failure rate.

Carcinoma↗
PubMed1977

Predicting success in psychiatric training for foreign medical graduates: II. Patterns in course.

Faculty ratings of 22 foreign medical graduates ('FMGs'), all of whom entered psychiatric residency training at the University of Missouri-Columbia from 1966 through 1973, were compared with those of a similar group of North American medical graduates ('AMGs'). An on-going evaluation programme provided data for a variety of parameters ranging from 'theoretical knowledge' to 'clinical skills'. Results indicated that in most of performance the median FMG started at a level substantially lower than that of the median AMG and very slowly caught up. When achievement criteria were utilized it became apparent that, at least by the third year of training, 'superior' FMGs could equal or surpass the median performance of 'superior' AMGs, whereas 'marginal' residents, whether foreign or native-born, seldom attained even competence in most major spheres of functioning. Implications of these findings and those in related studies are discussed.

Clinical Competence↗
PubMed1976

Attenuation of gastric lesions by psychological aspects of aggression in rats.

Rats that fought with each other in response to electric shock showed reduced gastric lesions in comparison with animals that received the same shocks alone so that fighting behavior did not occur. Also, gastric lesions were similarly reduced in animals that fought even though they could not physically contact one another because of a barrier between them, so that the "protective" effect of fighting derived from release of, or display of, fighting behavior and did not require physical combat. A second experiment showed that animals that received shock together but did not engage in fighting behavior showed no reduction of gastric lesions, so that the protective effect of fighting was not an artifact of animals receiving shock together. Possible explanations for why fighting behavior reduces gastric lesions are discussed.

Adaptation, Psychological↗
PubMed1975

Transcultural attitudes toward homocide and suicide.

Using the concept that homicide and suicide are complex sociopsychiatric phenomena clearly influenced by cultural norms and values that define which behaviors are viewed as deviant, the investigators constructed a small sample model to determine relevant qualitative attributes of public opinion. A stratified factorial sample of 258 subjects distributed among eight large cities throughout the world was selected for interviewing. The 2,603 resulting statements were then subjected to content analysis and categorization. Results indicated that people in cities, regardless of location, are most concerned about crimes of violence, especially homicide, and those against property. Other kinds of life-threatening offenses such as arson, war, and suicide are seldom seen as important "crimes." Many people endorse a problem-solving approach to dealing with crime and criminals, but a reservior of traditional, punitive attitudes clearly remains among the less educated, lower socioeconomic classes. A commonality of many attitudes in these various urban centers does suggest that modern communication techniques may well have a modulating effect on culture-bound orientations toward crime.

Attitude↗