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Biomedical subjects

M D Carpenter

Publications and source records attributed to M D Carpenter.

15 recordsLinked to original sources
PubMed2000

Investigation of binaural interference in normal-hearing and hearing-impaired adults.

When speech recognition testing is performed under diotic conditions, some elderly persons with asymmetric hearing loss exhibit a phenomenon in which the performance of the poorer ear interferes with that of the better ear. This binaural interference phenomenon has been estimated to occur in 8 to 10 percent of elderly hearing aid users. The purpose of the present study was to investigate the prevalence of this phenomenon in groups (n = 12) of young and elderly listeners with normal hearing, plus groups of elderly listeners with hearing loss who were aided or unaided. Of 48 subjects tested, only 2 exhibited significant evidence of binaural interference, a result that is close to that expected by chance. Although both of these subjects were elderly, one had normal hearing and the other was aided binaurally. A third elderly unaided subject exhibited a significant binaural advantage. Further studies are needed to determine the prevalence of binaural interference in normal-hearing or hearing-impaired listeners in any decade of life.

Adult↗
PubMed1997

Community violence and inpatient assaults: neurobiological deficits.

The goals of this study were to examine the relationship between community violence and inpatient assaults and to identify neurological and neuropsychological deficits underlying violent behavior. Thirty-three inpatients with a history of community violence were compared with 69 patients who did not have such a history. Inpatient assaults were recorded for 4 weeks; a neurological/neuropsychological battery was then administered. Patients without community violence were more likely to show transient or no violence while in the hospital. Patients with community violence performed more poorly on the Wisconsin Card Sorting Test and on psychomotor tasks, impairments that are consistent with frontal lobe dysfunction. Inpatient assaults were not associated with these neuropsychological impairments. They were related, however, to impairment on frontal motor programming tasks and a history of community violence.

Adolescent↗
PubMed1992

Methylphenidate augmentation therapy in schizophrenia.

Eight schizophrenic inpatients participated in a 2-week double-blind crossover study to test the efficacy of methylphenidate treatment for patients on a stabilized neuroleptic dose. All were young men with a childhood history of hyperactivity. The instruments used, the Brief Psychiatric Rating Scale, Scale for Assessment of Positive Symptoms, Scale for Assessment of Negative Symptoms, and Nurses Observation Scale for Inpatient Evaluation, showed no significant differences between stimulant and placebo conditions. One patient suffered a repeated pressor effect and was removed from the protocol. However, staff and self-report found some improvement in 3 patients and a slight worsening in 1.

Adult↗
PubMed1989

Intracerebroventricular infusion of interleukin 1 rapidly decreases peripheral cellular immune responses.

Low doses (50-200 pg or 3.1-12.4 fmol) of interleukin 1 (IL-1) infused into the brain of rats produced rapid suppression of various cellular immune responses in peripheral lymphocytes of rats. Fifteen minutes after infusion of purified IL-1 beta into the lateral ventricle, natural killer cell activity, response to phytohemagglutinin stimulation, and interleukin 2 production were markedly suppressed in lymphocytes isolated from blood and spleen. These effects were due to infusion of IL-1 into brain since they did not occur when IL-1 was infused into the cisterna magna (essentially posterior to brain) or was injected intraperitoneally. Effects of IL-1 in brain could be blocked by simultaneous infusion of alpha-melanocyte-stimulating hormone, which is known to block the biological actions of IL-1. To stimulate release of endogenous IL-1 in brain, lipopolysaccharide was infused; this produced similar effects as IL-1, and these effects also were blocked by alpha-melanocyte-stimulating hormone. At longer intervals after infusion of IL-1 and lipopolysaccharide (3, 6, and 24 hr), immune responses returned to baseline or remained suppressed; i.e., "rebound" immunopotentiation did not occur. Finally, IL-1 infusion suppressed cellular immune responses in adrenalectomized animals, thereby showing that the effects of central IL-1 on peripheral cellular immune responses were, at least in part, independent of the stimulatory effect of IL-1 on secretion of adrenal hormones. These results indicate a link from brain to peripheral immune responses by means of action of a cytokine acting in the brain.

Animals↗
PubMed1989

Performance of Leghorn type hens fed two levels of energy and a synthetic estrogen during the growing period.

Feeding of an estrogen, dienestrol diacetate, at 352 mg/kg of diet to December-hatched White Leghorn type pullets, from 16 to 20 wk of age, caused onset of production to be delayed approximately 3 wk. The dietary dienestrol diacetate also resulted in increased body weights at 30 and 46 wk in one experiment. Hens receiving the estrogen laid significantly (P less than .05) heavier but fewer eggs during most of the production year than did those fed diets without the estrogenic compound. The addition of 2.2% fat to diets of pullets from 0 to 20 wk of age failed to influence their performance in the layer house.

Animal Feed↗
PubMed1988

Ethnic differences in seclusion and restraint.

Data on seclusions or restraints were analyzed by ethnic group for 587 patients in 19 New York State psychiatric hospitals for a 4-week period. No differences among White, Black, or Hispanic patients were found for sex; type of ward where episode occurred; frequency of, length of, or reason for confinement; or the administration of medication as needed. The groups did differ in age, diagnosis, and target of their assaults. When analyzed by age groups, minority patients were not overrepresented in the secluded/restrained sample. Age was the most important variable to account for ethnic differences in confinement.

Adult↗
PubMed1988

Variations in seclusion and restraint practices by hospital location.

Data from a survey of seclusion and restraint practices in New York state hospitals were analyzed to determine if they differed by hospital location. The study included 19 hospitals--five in New York City, four in New York City suburbs, three in large towns, and seven in small towns. Overall, New York City and large-town hospitals had the highest rates of seclusion and restraint, but analysis by age group showed that New York City had the lowest rate for patients under age 35, who constituted the majority of patients who were secluded or restrained, and large towns had the highest rate. Compared with suburban and small-town hospitals, city and large-town hospitals used seclusion more often than restraint and had a higher ward census and a lower-staff patient ratio. In all groups males and blacks were overrepresented compared with the hospital population. The authors believe clarification of regional variations in assaultive behavior is important for treatment and system planning.

Adolescent↗
PubMed1985

Multiple admissions to an urban psychiatric center: a comparative study.

Based on data from medical records of an urban psychiatric center, 113 patients previously identified as having multiple admissions--three or more admissions in 365 days--were compared with 113 patients without multiple admissions who were matched for age, sex, and admission status. No significant differences were found between the two groups on such variables as racial-ethnic background, diagnosis, or living arrangements before and after their index hospital stay. However, patients with multiple admissions were significantly more noncompliant with medication and significantly more likely to abuse drugs or alcohol. They also were younger at their first hospitalization and had more previous hospital admissions, shorter lengths of stay, and more incidents of leave without consent than the patients who did not have multiple admissions.

Adult↗
PubMed1983

Species-related innate resistance to Schistosoma mansoni. Role of mononuclear phagocytes in schistosomula killing in vitro.

Resistance to infection with the multicellular parasite Schistosoma mansoni has been previously demonstrated to vary among several host species. The current investigation was designed to examine the basis for this species-related resistance in vitro. Adherent peritoneal macrophages or peripheral blood mononuclear cells from several species of host animals were incubated with S. mansoni schistosomula for 18-24 h; parasite viability was then assayed by methylene blue exclusion. Peritoneal exudate macrophages from susceptible species, such as mice (C57Bl/6) and hamsters killed, respectively, 6.6 +/- 2 and 8.0 +/- 2% of incubated schistosomula. In contrast, cells from resistant species: rats, guinea pigs, and rabbits, killed 21 +/- 2.3, 15 +/- 4.6, and 17 +/- 5.5%, respectively. Furthermore, blood monocytes from rabbits resulted in a mean of 25.9 +/- 2.8% dead organisms. Schistosomula killing by mononuclear phagocytes obtained from resistant species (rats or rabbits) was dependent on the cell/parasite ratio. Significant schistosomula mortality resulted from culture supernatants of rat macrophages or rabbit monocytes. Killing by cells from both species was significantly reduced upon addition of L-arginine, while catalase reduced killing only by rat macrophages. We conclude that mononuclear phagocytes may play a key role in species-related innate resistance to schistosomiasis; their in vitro schistosomulicidal activity parallels the known in vivo susceptibility of the donor species. Killing is mediated by lysosomal enzymes (arginase) and by products of oxidative metabolism, the predominant mechanism depends on the specific animal species.

Animals↗
PubMed1981

Predicting the community performance of vocational rehabilitation clients.

The outcome for 70 chronic psychiatric patients who had completed a clerical training program at a state hospital rehabilitation center was examined after they had spent some time in the community. Successful completion of the program was found to be the strongest predictor of successful vocational functioning in the community. The only demographic variables associated with this posthospital performance were race, marital status, and living arrangements. Patients who were black, who were or had been married, or who did not live with their parents were more likely to perform at a high level in the community. It is suspected, however, that race was predictive of outcome only because it was highly correlated with living arrangements.

Adult↗