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Biomedical subjects

B Graber

Publications and source records attributed to B Graber.

At least 19 recordsLinked to original sources

Yohimbine and naloxone: effects on male rat sexual behavior.

We evaluated the effects of yohimbine (2 mg/kg) and naloxone (5 mg/kg), separately and in combination, on copulatory behavior in male rats. In Experiment 1, yohimbine evinced decrements in intromission frequency, ejaculation latency, and copulatory efficiency, whereas naloxone administration was followed by an increased ejaculation latency, and the combination of yohimbine plus naloxone was without effect. In Experiment 2, yohimbine evinced decreases in intromission frequency, ejaculation latency, copulatory efficiency in the first, but not subsequent, copulatory series, as well as a decreased latency to sexual exhaustion. Further, treatment with yohimbine alone, naloxone alone, or yohimbine plus naloxone was followed by a reduction in the number of ejaculation prior to sexual exhaustion. Thus, at the doses tested, no synergistic effects were observed for the combination of yohimbine plus naloxone.

Animals

Clozapine for psychosis in Parkinson's disease.

The clinical efficacy of clozapine, an atypical antipsychotic, in treating levodopa-induced hallucinations was investigated in five patients with Parkinson's disease under open label conditions. Two patients could not tolerate clozapine, even in doses as low as 12.5-25 mg daily, because of extreme sedation. Three patients could tolerate clozapine and experienced improvement or elimination of their hallucinations at doses below 100 mg daily. Despite a significant risk of adverse effects, cautious use of clozapine in low doses may be beneficial for patients with levodopa-induced psychosis who do not respond to more conservative measures.

Aged

Neuroendocrine responses to exogenous estrogen: no differences between heterosexual and homosexual men.

Plasma LH concentrations were determined in 55 men before and for four days following injection of 10 mg, 20 mg, or 30 mg Premarin or a placebo injection of vehicle. Testosterone (T) and dihydrotestosterone (DHT) concentrations were also determined in plasma samples taken just prior to Premarin or placebo injection and in samples taken three days later. All subjects provided self-descriptions of their sexual orientation and, based upon these descriptions, were classified as heterosexual (N = 39) or homosexual (N = 16). Premarin injection resulted in a reliable reduction in plasma LH 24 hr later. In subsequent samples, LH values rose and in many cases exceeded baseline levels, most reliably in those subjects receiving the 10 mg dose. Contrary to some previous reports, we observed no significant differences between heterosexual and homosexual subjects in the likelihood of their exhibiting elevated LH concentrations following exogenous estrogens. T, but not DHT, concentrations were suppressed after Premarin injection in both groups of subjects. Other than Premarin dosage, we could not identify any variable which predicted the likelihood of elevated LH values.

Adult

Brain structure and function in sexual molesters of children and adolescents.

Sixteen men incarcerated in a state psychiatric facility pursuant to sexual molestation of children and/or adolescents were evaluated by computed tomography (CT) head scans and regional cerebral blood flow (rCBF) estimation. Compared with controls, child molesters were found to have thinner and less dense skulls and lower rCBF values. Variations from control values in rCBF and characteristics of CT head scans for the sex offenders suggest a role for cerebral dysfunction in the etiology of their aberrant behavior.

Adult

A thirteenth cranial nerve: the cloacal nerve.

The completion by vertebrates of micturition, defecation, and copulation via the cloaca or its derivatives is hypothesized to be best explained by the existence of a thirteenth cranial nerve, the cloacal nerve, which, similar to the facial and trigeminal nerves, functions as a mixed cranial nerve containing both general and special components.

Animals

EEG during masturbation and ejaculation.

The occurrence of a distinctive EEG pattern specifically related to sexual arousal and orgasm would provide a reliable and convenient means of identifying such events in the laboratory and would also provide clues to cerebral structures involved in the processes. EEG-polygraph recordings were obtained under rigorously controlled conditions in four normal male subjects during masturbation and ejaculation. The EEG data were subjected to both impressionistic and quantitative analyses. They showed no remarkable changes during the sequence of relevant physiological responses. The sole effect was a slight depression of alpha activity, a well-known nonspecific effect associated with changes in attention and arousal. Examination of the literature shows little agreement among reported results of studies of EEG changes during orgasm. It is likely that at least some reported changes were artifactual. It is concluded that the case for the existence of EEG changes specifically related to sexual arousal and orgasm remains unproven.

Adult

Neuropsychological deficit and regional cerebral blood flow in schizophrenic patients.

The paper examined the relationship between the scales of the Luria Nebraska Neuropsychological Battery and measures of cerebral blood flow in a sample of 51 chronic schizophrenic patients without a history of brain damage. Of 88 correlations between the two sets of data, 22 were significant at the .05 level. The measurement of left anterior gray flow were particularly predictive of LNNB scores, although all correlations were at a moderate level, ranging from -.24 to -.38. The data are consistent with the hypothesis that neuropsychological testing performance in schizophrenics is related to brain function rather than merely reflecting deficits due to anxiety or other psychiatric features which have been hypothesized to invalidate neuropsychological assessment in this population. The data are also consistent with the notion that schizophrenia is more likely associated with left-anterior functioning, and that gray-matter measures in rCBF are effective predictors of neuropsychological performance.

Adult

Regional cerebral blood flow in schizophrenics. Tests using the xenon Xe 133 inhalation method.

Measurements of intrahemispheric and bilateral regional cerebral blood flow (CBF) for gray and white matter were compared in 29 schizophrenic patients and 22 normal controls, using the xenon Xe 133 inhalation method. Results showed significantly lower CBF values for all brain regions in the schizophrenic group, and post hoc comparisons showed relatively greater reduced gray-matter CBF values in the anterior areas of the brain. There was also a left-hemisphere frontal loss similar to that reported previously, although it was in the context of a generalized loss in anterior functioning. Interhemispheric comparison within both groups showed no differences between homologous regions for gray matter, and greater white-matter CBF values in the right hemisphere than in the left hemisphere. The findings support a hypothesis of a bilateral anterior deficit in schizophrenia.

Adolescent

Aging and performance on the Luria-Nebraska neuropsychological battery.

The Luria-Nebraska Battery has been shown to be a valid measure of neuropsychological functioning in younger adults; however, little validity research with the elderly has been reported. Seventy-eight healthy elderly adults (mean age = 72.2 years) were tested with the Luria-Nebraska Battery and 92% of the profiles were found to be within normal limits. Significant age-related effects were also found on the Luria-Nebraska Battery. Similarly, the healthy elderly were divided into two age groups, young-old (60-74) and old-old (75+). Only the expressive speech and writing scales showed significant differences, and these were in the opposite direction one might expect, in that the old-old group performed significantly better. Additionally, the performance of 100 elderly brain damaged patients (mean age = 68 years) was examined and 86% of the profiles indicated the presence of brain damage. Overall, this study suggests that the Luria-Nebraska Battery may be a useful measure of neuropsychological functioning in elderly groups.

Aged

Effect of alcohol ingestion on regional cerebral blood flow.

Regional distribution of cerebral blood flow was assessed in 10 normal social drinkers following consumption of .75 g/kg alcohol and in a control session without alcohol. Alcohol increased blood flow in the gray matter in all brain areas except the left anterior area. The results are discussed in terms of the effect of alcohol on regional cerebral activation.

Adult

Brain damage among mentally disordered sex offenders.

The incidence and nature of structural brain dysfunction was investigated in a pilot study sample of individuals currently assigned the Nebraska Penal Code designation of mentally disordered sexual offender. It was hypothesized that the sexual offenders would show a significantly higher incidence of dysfunction than a psychosocially normal group as evidenced by computed tomography scan measures, regional cerebral blood flow, and neuropsychological instruments. The hypothesis was tested by two different methods. One method used a 160 by 160 printout of density numbers generated by computer from computed tomography scans administered to the sexual offenders. The second method used mean blood flow data generated from a Harshaw TASC-5 Regional Cerebral Blood Flow analysis system. Additionally, the Luria-Nebraska Neuropsychological Test Battery was administered as a measure of the behavioral correlates of brain dysfunction. Preliminary analyses indicate that 50% of the sexual offenders tested showed brain dysfunction as demonstrated by decreased density measures, decreased blood flow, and performance deficits on the Luria Battery. The implications of these findings, if confirmed, are substantial on issues of criminal responsibility, sentencing, treatment, and rehabilitation of the sex offender. Case reports of the patients studied are presented.

Adult

Difference in brain densities between chronic alcoholic and normal control patients.

The densities of the brains of 11 chronic alcoholics were compared with those of 11 age-matched normal control subjects. Densities were determined from the density numbers generated by computerized tomography at three levels of the brain-the highest level of the lateral ventricles and the next two higher levels-with adjustments made to control for possible artifacts in the data. The advantage of the dominant hemisphere over the nondominant hemisphere was lessened in alcoholics.

Adult

Structural brain deficits in schizophrenia. Identification by computed tomographic scan density measurements.

Research has suggested the presence of brain damage as a cause or concomitant of chronic schizophrenia. The most recent research in this area has been the identification of abnormalities in schizophrenia by computed tomographic (CT) scans. A study was done to investigate localized changes in CT scan density numbers in the brains of schizophrenic patients, as opposed to the brains in normal control subjects. Twenty-four normal subjects and 23 schizophrenic patients were tested with CT scans. Density measurements in each area of the brain (left, right, anterior and posterior) were compared to three separate CT scan levels. Of six measurements of anterior left-hemisphere density, it was found that five showed lower density in schizophrenic brains, as compared with normal brains. Of the remaining 18 measurements that evaluated other areas of the brain, only three differentiated between schizophrenic patients and normal subjects. The results support the hypothesis that there are primary structural deficits in some schizophrenic patients, and these deficits are centered in and around the anterior area of the left (dominant) hemisphere. The results also demonstrated further implications.

Absorptiometry, Photon

Time factors and orgasmic response.

A retrospective review of data from a 619-member female sample presenting for treatment of sexual dysfunction was conducted to determine if foreplay and intromission duration variables were related to sexual dysfunction. Patients were assigned to coitally anorgasmic and noncoitally anorgasmic, coitally anorgasmic and noncoitally orgasmic, or coitally and noncoitally orgasmic categories on the basis of interview data collected by a nurse-physician team. Duration measure differences are not found between diagnostic categories. However, significant differences are reported for the duration measures between status of relationship groupings: married, single, divorced, or cohabitating (p less than 0.05). Data from the sexually dysfunctional sample are compared with data from the surveys of Kinsey, Fisher, and Hunt. The importance of extended foreplay and intromission in enhancing female coital orgasmic response is not supported.

Female