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Biomedical subjects

S Levine

Publications and source records attributed to S Levine.

At least 163 records · Page 9Linked to original sources
PubMed1994

The mock trial in psychiatric staff education.

The mock trial is an important educational technique that has seldom been reported in the medical literature. In this paper we describe the evolution of mock trials as a regular component in the educational program for our multidisciplinary staff. The mock trial is not only an excellent strategy for teaching about the interface between psychiatry and the law, but also for teaching about malpractice, documentation, and medical reasoning. The most effective presentation used an actual case from our facility, practicing attorneys, and an experienced judge in a condensed version of a trial.

Forensic Medicine↗
PubMed1993

Maternal regulation of the hypothalamic-pituitary-adrenal axis in the infant rat: the roles of feeding and stroking.

Twenty-four hours of maternal separation results in increased secretion of ACTH and corticosterone (CORT), suggesting the hypothalamic-pituitary-adrenal (HPA) axis is regulated by some aspect of maternal behavior. Previous results indicate that feeding plays a role in maintaining low levels of CORT in 12-day-old pups. In Experiment 1 basal and stress levels of CORT and ACTH were measured in maternally-deprived pups either provided or not with milk to determine whether: (1) feeding maintains ACTH secretion at low levels, and/or (2) feeding maintains the adrenal insensitive to ACTH. The results showed that, although ACTH levels were markedly low (compared to previous values reported by this laboratory) for both groups, only non-fed pups showed a robust increase in basal and stress CORT levels. During the deprivation period in Experiment 1, all pups were manually stroked to induce urination and defecation, suggesting an effect of stroking on ACTH secretion. Experiment 2 examined this hypothesis. Stroking suppressed stress-induced elevations of ACTH secretion due to maternal deprivation. CORT levels, however, were elevated in all deprived pups. The results indicate that maternal regulation of the infant's HPA axis occurs at multiple levels. Feeding appears to regulate adrenal sensitivity, whereas anogenital stroking inhibits the activation of centrally-controlled components of the axis.

Adrenocorticotropic Hormone↗
PubMed1993

Multiple meningiomas in a patient with constitutional ring chromosome 22.

We report on a patient with multiple congenital anomalies and ring chromosome 22 who died at age 16 years of bronchopneumonia. Autopsy documented multiple psammomatous meningiomas of the spinal dura and tentorium. Tumor tissue for cytogenetic analysis was not available. Although abnormalities of chromosome 22 in tumor tissue have been reported, to our knowledge, this is only the third report of a constitutional chromosome 22 abnormality associated with the development of meningiomas. Thus, a constitutional chromosome 22 abnormality may predispose to the development of meningiomas.

Abnormalities, Multiple↗
PubMed1993

A novel non-ataxic guinea pig strain with cerebrocortical and cerebellar abnormalities.

This is the first description of GS guinea pigs, a partially inbred, non-ataxic, albino Peruvian (long-hair) strain with abnormal motor behavior and seizures. GS guinea pigs show gross and microscopic cerebellar and microscopic cerebrocortical abnormalities compared to Hartley strain animals. There is little difference between GS and short-hair guinea pig strains in Purkinje cell function, electrically evoked Ca2+ transients or immune responsiveness. The GS strain may prove useful in studying altered functions of the cerebellum in human disease.

Animals↗
PubMed1993

Maternal regulation of adrenocortical activity in the infant rat: effects of feeding.

Basal and stress-induced corticosterone release in the infant rat has been shown to be inhibited by some aspect of maternal care. The following studies examined specific maternal cues that might be responsible for this regulation. In Experiments 1 and 2, 12-day-old pups remained with their dam but were either prevented or not from feeding; at the end of 24 hr, basal and stress-induced corticosterone levels were measured. Only those animals that were able to feed showed the hyporesponsiveness characteristic of nondeprived animals, suggesting that feeding rather than some other aspect of maternal care was the critical variable. In Experiment 3, all animals were maternally deprived, and some of them were fed via an intracheek cannula. Once again, feeding led to a pronounced diminution in both basal and stress-induced levels of corticosterone. Our results point to feeding as one of the critical features responsible for the inhibitory effect of the dam on the infant's adrenocortical activity.

Animals↗
PubMed1993

Ontogeny of corticosteroid receptors in the brain.

1. In the brain, glucocorticoids bind to both the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). These receptors show clearly distinct developmental patterns in the infant rat. 2. Low levels of GRs are present around the time of birth throughout the brain. Concentrations rise slowly, and do not achieve adult levels until the third week of life, approximately. GR affinity for corticosterone is higher perinatally than at later ages. Receptor microdistribution changes dramatically during ontogeny. In particular, certain regions, such as the suprachiasmatic nucleus of the hypothalamus, express high levels of receptor only during the first week of life. GRs may show impaired capacity to undergo transformation and/or nuclear translocation during the second postnatal week. Environmental manipulations during early ontogeny (e.g., early handling) may have permanent effects on GR capacity. 3. MRs are present at very low concentrations in the first days of life. Binding capacity rises rapidly thereafter and resembles that found in the adult by the end of 1 week. Neither binding affinity in vitro nor overall distribution changes with age. As in the adult, low doses of corticosterone, in vivo, bind mainly to the MRs. Levels of corticosterone are low and relatively unperturbable in the intact infant rat. It is likely, therefore, that most of the physiological actions of this hormone during this period are mediated by the MR.

Aging↗
PubMed1993

Children with mucopolysaccharidosis: perioperative care, morbidity, mortality, and new findings.

The perioperative care, morbidity, and mortality in 30 patients with mucopolysaccharidosis (MPS) are presented. They underwent a detailed preoperative assessment and were anesthetized 141 times. An intravenous induction technique was used in most patients. It was easier to see the vocal cords, during laryngoscopy, in children with Hurler syndrome (HS) when they were younger (23 v 41 months, P < or = .01) and smaller (12 v 15 kg, P < or = .05). Preoperative obstructive breathing was associated with a significantly higher incidence of postextubation obstruction (P < or = .05). A total of 28 children underwent bone marrow transplantation (BMT); this reversed upper airway obstruction and also reversed intracranial hypertension. In children with HS, the incidence of odontoid dysplasia was 94%; 38% demonstrated anterior C1-C2 subluxation. Head and neck manipulation was limited in children with cervical spine defects. None of the 30 patients experienced spinal cord morbidity. One child suffered an intraoperative stroke; another, pulmonary edema. Severe and extensive coronary obstruction was responsible for 2 intraoperative deaths. Coronary angiography underestimated coronary artery disease.

Adolescent↗
PubMed1993

Food search demand effort effects on behavior and cortisol in adult female squirrel monkeys.

Laboratory-born, group-housed, ovariectomized adult female squirrel monkeys (Saimiri sciureus) were exposed to feeding conditions in which the availability and accessibility of food were altered. Both high- and variable-demand feeding conditions were utilized. The variable-demand condition required alternating periods of high effort (120% of normal daily intake presented) and low effort (600% of normal daily intake presented) to obtain food for 10-12 weeks. An additional group was exposed solely to the high-demand condition for 10 weeks. Blood samples were obtained weekly, and behavioral observations were conducted daily. In the variable-demand condition, plasma cortisol was elevated above baseline during the periods of high effort. For the constant high-demand group, cortisol was elevated for the duration of the experimental treatment. Contact with other animals, as well as a species-specific inactive posture, decreased as a result of exposure to high demand. Maintenance of body weight indicated that nutritional deprivation did not occur. The imposition of increased food-seeking efforts provides an ecologically relevant and noninvasive method of producing chronic stress in the squirrel monkey.

Animals↗
PubMed1993

Early experience effects on the development of fear in the squirrel monkey.

This study was conducted to determine whether juvenile squirrel monkeys exposed to a snake for a 60-min episode during the preweaning period display behavioral and physiological responses to a snake similar to those displayed by feral-born adult monkeys. Juvenile male monkeys born to feral mothers in the lab were either exposed to a live snake during infancy or were snake-naive. Simultaneously tested were adult feral-born and adult lab-born (snake-naive) males. Juveniles exposed as infants to a snake displayed behavioral responses and plasma cortisol elevations following exposure to the snake that were similar to those of feral-born adults. In contrast, the snake-naive monkeys, regardless of age, rarely vocalized at the snake and displayed lower plasma cortisol elevations. These behavioral and physiological responses did not appear to be elicited by a moving animate stimulus per se, insofar as exposure to a moving fish elicited minimal behavioral changes and no cortisol elevations. In contrast to previous findings, these studies indicate that lab-born snake-naive squirrel monkeys are responsive to snakes, but that experience with snakes in infancy produces behavioral and physiological responses more similar to those observed in feral-born monkeys.

Animal Communication↗
PubMed1993

The feasibility of smoking bans on psychiatric units.

We conducted a prospective study of a smoking ban on a general inpatient psychiatry service in response to staff concerns about the feasibility of a proposed hospital-wide ban. Demographic information, smoking history, and DSM III-R diagnoses were obtained for consecutively admitted patients during two study conditions: smoking and nonsmoking. A log of p.r.n. medication, seclusion, restraint, elopement, incident reports, and smoking-related discharges was kept for each patient. Chi-square analysis of 232 patients for whom demographic, smoking, diagnostic, and log data were complete showed no significant differences between study conditions for demographic or diagnostic variables. Two-tailed t-test analysis of the log data for these 232 patients showed no significant difference in disruptive incidents during smoking and nonsmoking conditions (p = 0.183). Fifty staff members answered pre- and post-ban questionnaires. Paired t-test analysis demonstrated a significant change in staff attitude toward supporting the ban. These data indicate that smoking can be stopped on inpatient psychiatry units without increases in unit disruption or adverse effects on staff morale.

Adult↗
PubMed1993

Temporal and social factors influencing behavioral and hormonal responses to separation in mother and infant squirrel monkeys.

The behavioral and hormonal responses of mother and infant squirrel monkeys (Saimiri sciureus) were examined to assess temporal and environmental factors that influence the response to separation. In two experiments evaluating the effects of 1-, 3-, 6-, and 24-hr separations, it was found that signs of infant behavioral agitation decreased over time, whereas adrenocortical activation persisted or even increased. Moreover, two separation environments were shown to differentially affect behavioral and hormonal responses. Separated infants vocalized significantly more when their mothers were proximal than when isolated, but showed lower cortisol levels in the adjacent separation than in the total-isolation condition. These data indicate that the intensity of the infant's calling response cannot be used to predict internal state (as reflected by cortisol levels). Furthermore, vocalization rate is highly dependent upon contingent stimuli, such as the presence of maternal cues. Following separation, the mothers also showed elevated cortisol levels. However, both the magnitude and pattern of the response differed considerably from that of the infant.

Animals↗
PubMed1993

Effects of maternal deprivation on the ACTH stress response in the infant rat.

Prolonged maternal deprivation during early ontogeny results in increased basal and stress-induced corticosterone levels. In the following experiments we examined whether these increases were due, at least in part, to augmented ACTH secretion. Thus, ACTH levels were measured in 24-hour maternally deprived and nondeprived 6-, 9-, and 12-day-old pups exposed to a mild stressor (i.e. saline injection followed by placement in a novel environment at room temperature). The results showed: (1) nondeprived pups showed a small response to saline--the response of deprived pups, however, was greater than that of nondeprived pups; (2) the magnitude of the response increased with age; (3) ACTH levels remained elevated for at least 30 min. Subsequent experiments examined whether the continuous exposure to novelty and/or loss of body heat could explain the persistence of this response. Neither variable affected the ACTH response to saline. Our results indicate that factors of maternal origin are partly responsible for the regulation of the ACTH response to stress. Furthermore, the persistence of the response suggests that the negative feedback system in the infant is immature.

Adrenocorticotropic Hormone↗
PubMed1993

The influence of social factors on the response to stress.

The studies described in this paper provide evidence for the importance of social factors in determining the response of the hypothalamic-pituitary-adrenal (H-P-A) system to stress. The presence of familiar social partners can reduce or eliminate the cortisol response to either loss of a significant social relationship or to fear inducing stimulus. In contrast, disruptions of ongoing social behavior can be a potent activator of the H-P-A axis. Social isolation, the formation of new social groups of unfamiliar monkeys, and disruption of social behavior under conditions of high demand food seeking, all result in elevations of circulating cortisol. Of importance is that these elevation persist for protracted periods of time and represents an animal model of chronic stress.

Animals↗