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Biomedical subjects

S Levine

Publications and source records attributed to S Levine.

At least 487 records · Page 27Linked to original sources
PubMed1978

ACTH and ACTH4-10 modification of neophobia and taste aversion responses in the rat.

A series of experiments assessed the effects of ACTH and the ACTH analogue ACTH4-10 on drinking in conditioned taste aversion and neophobic situations. Both substances delayed the extinction of a conditioned taste aversion established by a single pairing of lithium chloride with milk (Experiment 1). However, in this situation, the ACTH parent peptide was more potent behaviorally. Administration of ACTH suppressed milk consumption in animals with no toxicosis experience (Experiment 2). This effect was apparently not due to the conditioning of a taste aversion (Experiment 3) with ACTH serving as a weak aversive unconditioned stimulus. Administration of exogenous ACTH (Experiment 4) or ACTH4-10 (Experiment 5) did not enhance neophobia; however, repeated injections of ACTH suppressed drinking. This ACTH suppression was related to the familiarity/novelty of the subtance being consumed. The neophobic response to milk eas no accompanied by pituitary-adrenal activation (Experiment 6). Both neophobic and conditioned taste aversion situation appear to be useful for assessing peptide effects on consummatory behavior.

Adrenocorticotropic Hormone↗
PubMed1978

The relationship of psychosocial factors to coronary heart disease in the Framingham study. I. Methods and risk factors.

Questionnaires administered to 1822 members of the Framingham Heart Study from 1965 to 1967 provided measures of personality type, sociocultural mobility, situational stress and somatic strain. Clusters of questions selected by a panel of experts, and verified by item and factor analysis, formed scales of Type A behavior and other psychosocial states. The Framingham Type A behavior scale was significantly correlated with daily stress (.47), emotional lability (.43), tension (.42), anger symptoms (.34), and ambitiousness (.31). Women were less likely than men to be ambitious and to exhibit the Framingham Type A behavior, and were more likely than men to be emotionally labile, tense, and to suppress hostility. Few consistent associations were found between psychosocial stress measures and levels of blood pressure or cholesterol. Social status and marital conflicts were significantly associated with patterns of smoking. The Framingham Type A behavior pattern and other psychosocial measures were not related to the level of CHD risk, as determined by the Framingham logistic equations.

Adult↗
PubMed1978

The relationship of psychosocial factors to coronary heart disease in the Framingham study. II. Prevalence of coronary heart disease.

In a cross-sectional study of 1822 persons aged 45 to 77 years of age, the association of 20 psychosocial scales with coronary heart disease (CHD) prevalence was assessed. Women (aged 45 to 64 years) with coronary disease scored significantly higher on the Framingham Type A behavior, emotional lability, aging worries, tension, and anger symptoms scales than women free of CHD. The prevalence of CHD was significantly higher among working women and housewives classified as Type A than as Type B behavior. Among men under 65 years, Framingham Type A behavior, aging worries, daily stress, and tension were associated with the prevalence of myocardial infarction (MI). For men and women over 65 years, marital dissatisfactions or disagreements were significantly related to the prevalence of CHD. In a multivariate analysis, the above associations were controlled for age, blood pressure, cholesterol, smoking, and other psychosocial scales. Among women under 65 years of age, Framingham Type A behavior and emotional lability remained significant discriminators of CHD prevalence. Aging worries significantly differentiated men under 65 with and without MI. Issues related to the interpretation of results from cross-sectional studies are discussed, and four hypotheses are suggested for future prospective work in this area.

Adult↗
PubMed1978

Lymphocytic inflammation produced by intracerebral implantation of zinc and other metals.

Sxteen pure metals were implanted as pellets of powder or as wires into the brains of rats. Al, Be, Cr, Fe, Pb, Sn, and W were relatively innocuous. Mg and Mn produced local necrosis. Bi, Cd, Co, Cu and Ni produced more severe local necrosis. Viable tissue adjacent to Co and Ni necrotic lesions had some perivascular lymphocytic infiltrates. Zn implants caused very little necrosis but adjacent areas had prominent perivascular lymphocytic cuffs. The infiltrates persisted for at least 4 weeks but disappeared as soon as the zinc was removed. Some compounds of zinc were also capable of inducing infiltrates. The perivascular infiltrates resembled the lesions of allergic encephalomyelitis, but there was no correlation between the ability of metal powders to induce lymphocytic infiltrates after intracerebral implantation and their adjuvancy after intraperitoneal injection with neural antigen.

Adjuvants, Immunologic↗
PubMed1978

Comparison of the effects of restricted morning or evening water intake on adrenocortical activity in female rats.

The effects of restricting daily water intake to either a 30-min morning or evening period were investigated on: (1) the overall circadian pattern of adrenocortical activity, and (2) adrenocortical activity during the 20-min period immediately after water presentation. Morning water restriction produced a substantial increase in pre-water levels of circulating corticosterone without affecting evening levels, thereby changing the form of the circadian pattern. In contrast, evening water restriction did not elicit any pre-water increase in corticosterone levels, and there was no change in the circadian pattern. Both morning and evening water restricted animals showed a pronounced and rapid decline in corticosterone levels during the 20-min post-water period, with levels dropping by more than 50% within 10 min of water presentation. The dissociation of the pre-water elevation and post-water decline in corticosterone evident in evening water animals indicates that these 2 processes may be governed by different factors. It is suggested that the pre-water effect involves circadian regulatory mechanisms whereas the post-water effect is associated with the process of reinforcement.

Adrenal Cortex↗
PubMed1978

Hormonal response to stress in the squirrel monkey (Saimiri sciureus).

The pituitary-adrenal and gonadal responses following stress were evaluated in the squirrel monkey. Plasma levels of cortisol (CS), ACTH and testosterone (T) were determined during a 4-h period following the combined stress of capture and ether anesthesia. The results indicated that the squirrel monkey manifests higher basal levels of steroids than typically found in other mammals. The endocrine response following stress was biphasic, involving an initial elevation and subsequent decline in hormone levels. Males manifested significantly higher plasma levels of CS and T and lower plasma levels of ACTH than did females.

Adrenal Glands↗
PubMed1978

Social organization and social behavior in two subspecies of squirrel monkeys (Saimiri sciureus).

Social organization and social behavior were examined in two subspecies of squirrel monkeys which differ markedly in the degree of sexual dimorphism. The Bolivian squirrel monkeys, the subspecies with greater sexual dimorphism, manifested a sexually segregated form of social organization, while the social organization of the Guyanese monkeys was sexually integrated. Dominance relationships were found to reflect these patterns of sexual segregation or integration; in the Bolivian social groups separate linear dominance hierarchies were established within each sex while the Guyanese monkeys established a single linear hierarchy which included both males and females. Relationships between males and females in the two subspecies appear to be regulated by two distinct mechanisms, dominance in the Guyanese monkeys and sexual segregation in the Bolivians.

Animals↗
PubMed1978

Suppression of experimental allergic encephalomyelitis by 6-hydroxyphthalaldehydic acid, O-(p-chlorobenzyl)oxime (EN3638).

EN3638 is a new oxime derivative of salicylic acid that has immunosuppressive properties. Oral administration of the compound to rats during the incubation period of experimental allergic encephalomyelitis (EAE) delayed the onset of clinical signs. EN3638 was effective in both ordinary and hyperacute forms of EAE. Doses of 50, 100, or 150 mg/kg daily, 250 mg/kg three times a week, or 400 mg/kg twice a week suppressed both clinical and histologic evidence of EAE during the course of therapy (as long as 4 weeks) and for 8 or more days thereafter. Clinical EAE developed after a full incubation period after discontinuance of EN3638, probably due to the persisting depot of antigen in oil. When EAE was produced without an oily depot, a single dose suppressed the disease for at least 5 weeks in some rats. EN3638 was effective when given only in the second half of the incubation period but not when given at the time that EAE lesions and signs develop. Passive transfer experiments suggested that the drug prevented and even reversed sensitization to neural antigens. It had only slight effect on fully sensitized lymphoid cells or on the recruitment of nonimmune inflammatory cells in the nervous system, and it was not acting as a source of salicylate or as an adrenocortical stimulator.

Animals↗
PubMed1978

Renal lesions induced induced by tilorone and an analog. Ultrastructure and acid phosphatase study.

Tilorone, 2,7-bis-(diethylaminoethoxy)-fluoren-9-one hydrochloride, an interferon inducer, has been shown to cause hydropic degeneration in choroid plexus and distal convoluted tubules of kidney. Ultrastructural and histochemical studies of the renal lesion produced by tilorone and one of its analogs revealed striking accumulation of vacuoles and/or acid-phosphatase-positive lemellar bodies retricted to glomeruli, ascending limb of Henle's loop, and distal convoluted tubules.

Alkaline Phosphatase↗
PubMed1977

Proteolytic enzymes in ordinary, hyperacute, monocytic and passive transfer forms of experimental allergic encephalomyelitis.

The changed patterns of proteolytic activity in brain and spinal cord of Lewis rats were examined in 4 different morphological variants of EAE: ordinary induced by the standard emulsion, hyperacute induced by an emulsion plus pertussis vaccine, passive induced by donor EAE cells, and monocytic induced by treatment of passive EAE with the immunosupressive drug tilorone. The following enzymatic changes were found: firstly, in ordinary EAE there was a 2--3.5-fold increase in cathepsins A and C (E.C. 3.4.14.1) in spinal cord one day following the appearance of paralysis with a smaller change in hindbrain, and none in the forebrain regions. With recovery from paralysis, levels of cathepsin A remained high in upper cord, and cathepsin C levels fell to about half. In contrast, increase in cathepsin D(E.C. 3.4.23.5) was smaller and occurred only 4--5 days after paralysis with the largest change in spinal cord areas and with only a small decrease on recovery from paralysis. Secondly, in hyperacute EAE, the increase in all cases was smaller with the largest change in cathepsin A level in upper spinal cord. In passive EAE, the most significant increase occurred only in the lower spinal cord for cathepsins A and C, and fourthly, in monocytic EAE induced by tilorone, there was an exceptionally large, 3-fold increase in cathepsin C in lower cord as compared to a 1.5-2 fold increase for other cathepsins. No major differences were observed on comparison of antigens from different sources (guinea pig and bovin spinal cord myelin peptide). An attempt is made to relate enzymatic changes to the morphological features of each variant with special reference to the nature of the infiltrating cells.

Acute Disease↗