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Biomedical subjects

J L Steinberg

Publications and source records attributed to J L Steinberg.

At least 19 recordsLinked to original sources
PubMed1995

Cerebellar blood flow in schizophrenic patients and normal control subjects.

We used 133Xe dynamic single-photon emission computed tomography (DSPECT) to measure the resting cerebellar blood flow in 17 neuroleptic-free schizophrenic and schizophreniform patients and 13 normal control subjects. A subset of these subjects (11 patients and 7 control subjects) additionally underwent activation studies during the Wisconsin Card Sorting (WCS) and Number Matching (NM) tests. Baseline relative cerebellar blood flow was significantly lower in older patients than in age-matched control subjects. For absolute cerebellar flow, there was a significant difference between patients and control subjects in the overall activation response (patients: NM 13.4% increase, WCS 15.7% increase; control subjects: NM 3.1% decrease, WCS 0.0% change). This difference was more pronounced in older subjects. Cerebral blood flow significantly increased during NM (patients: 21.3% increase, control subjects: 6.5% increase) and WCS (patients: 16.5% increase, control subjects: 9.7% increase). The difference in the magnitude of cerebral NM activation between schizophrenic patients and control subjects, although not statistically significant, may call into question the appropriateness of using NM as a control task in schizophrenic patients. Finally, we found no differences between the effects of WCS and NM on cerebellar or cerebral blood flow. Because of the small number of subjects in each group, the results of this study should be interpreted cautiously.

Adult↗
PubMed1994

Serotonin and impulsive/aggressive behavior in cocaine dependent subjects.

1. 10 male cocaine dependent patients and 10 sex matched controls were administered several behavioral measures of aggression including the Buss-Durkee Hostility Inventory, and The Brown-Goodwin Life History of Aggression. 2. All subjects were also administered a buspirone neuroendocrine challenge as a measure of serotonin function. 3. The cocaine dependent subjects were significantly more aggressive than the controls. 4. There was a significant correlation between the growth hormone response to buspirone and behavioral measures of aggression in the cocaine dependent subjects, but not in the controls. 5. There was no difference in the overall growth hormone response between the controls and cocaine dependent subjects, possibly due to differences in metabolism of buspirone. 6. This study supports a role for serotonin in aggression in cocaine dependent subjects.

Adult↗
PubMed1994

A preliminary neuroendocrine study with buspirone in major depression.

We administered the serotonin-1a agonist buspirone (0.4 mg/kg orally) as a neuroendocrine challenge agent to a group of male patients with DSM-III-R major depressive disorder (MDD) (n = 13) and a group of male healthy controls (n = 10). The primary hypothesis of the study was that the prolactin response to buspirone would be blunted in the depressed patients. The prolactin response was significantly lower in depressed patients than in controls. There was no significant relationship between placebo corrected-peak prolactin level and severity of depression or suicidality. There was a nonsignificant trend for the melancholic (n = 5) depressed patients to have a lower placebo corrected-peak prolactin level than nonmelancholic depressed patients (n = 8). Our findings support a role for the serotonin-1a receptor in the etiology of MDD, specifically at the postsynaptic site.

Adult↗
PubMed1993

Effects of tricyclic antidepressant treatment on tyramine-O-sulfate excretion in depressed patients.

The urinary excretion of tyramine-O-sulfate following an oral load of tyramine (Tyramine Challenge Test, 'TCT') was measured in a group of fourteen inpatients with unipolar and bipolar major depressive episode. TCT was done both during a pretreatment baseline period and following four weeks of treatment with tricyclic antidepressants. The change in TCT values after treatment correlated with improvement in depression. The previously described ability of TCT to discriminate between endogenous and nonendogenous depressed patients was confirmed at baseline. However, following tricyclic antidepressant treatment, TCT values were not significantly different between endogenous and nonendogenous patients.

Adult↗
PubMed1993

Serum homovanillic acid levels in schizophrenic patients and normal control subjects.

Schizophrenic patients with an early age at onset of illness had low baseline levels of homovanillic acid (HVA) in serum compared with schizophrenic patients with a late age at onset. After adjustments were made for age at onset, there was a significant partial correlation between positive symptoms and serum HVA. The relationship between positive symptom scores and serum HVA was shifted to the left in the early onset patients, suggesting a relatively increased sensitivity of dopamine-associated response. Patients with severe negative symptoms also had an earlier age at onset and a trend toward lower serum HVA. This study found no difference between mean serum HVA values in schizophrenic patients and normal control subjects.

Adult↗
PubMed1990

Effects of acute administration of diazepam and d-amphetamine on aggressive and escape responding of normal male subjects.

Normal males participated in sessions providing two operant response options and were administered either diazepam (study I and II) or d-amphetamine (study II). The acute effects of diazepam on human aggressive responding, which ostensibly subtracted points from another person, were determined in study I. Study II was conducted to determine the extent to which social context and response consequence influenced diazepam (study I) and d-amphetamine (previous research) effects on aggressive responding. In study II, the other response option was escape responding which protected the subject's counter from point losses. Aggressive and escape responding were engendered by subtracting points from the subject's counter, and maintained by initiation of intervals free of point loss. Point subtractions were attributed to the other person (study I) or to a machine (study II). Responding to accumulate points exchangeable for money was available in both studies. Acute diazepam administration decreased aggressive responding in most subjects (study I), slightly increased escape responding (study II), and decreased responding to accumulate points. In study II, d-amphetamine increased both escape responding and responding to accumulate points. The effects of d-amphetamine and diazepam were altered by the instructed source of point loss.

Aggression↗
PubMed1990

Human aggressive responses maintained by avoidance or escape from point loss.

During 50-min sessions, 6 male human subjects could press either Button A or Button B available as nonreversible options. Button A presses were nonaggressive responses and earned points according to a fixed-ratio 100 schedule. Prior to the experiment subjects were instructed that every 10 (fixed-ratio 10) Button B presses (aggressive responses) subtracted a point from a fictitious 2nd subject. A random-time schedule of point loss was used to engender aggressive responding. The instructions attributed these point losses to the Button B presses of the subject's fictitious partner. Aggressive responding either escaped or avoided point loss by initiating an interval free of point loss. The duration of the interval was varied systematically across sessions. Avoidance contingencies maintained a high rate of aggressive responding over 30 sessions in the absence of point loss. Escape contingencies also maintained aggressive responding across sessions, with rates of aggressive responding corresponding to rates of point loss.

Adult↗
PubMed1989

Effects of nicotine gum and tobacco smoking on human avoidance responding.

Three male smokers were exposed to a free-operant avoidance schedule in which a lever press postponed a point subtraction on a counter for twenty seconds. Subtractions were scheduled to occur every 5 seconds in the absence of lever presses. Prior to each experimental session the subject was administered varying amounts of nicotine via either chewing nicotine gum or smoking low or high nicotine yield cigarettes. Smoking cigarettes resulted in increased avoidance responding relative to baseline nonsmoking rates. Chewing nicotine gum did not produce changes in avoidance responding, however, nicotine blood levels produced by chewing nicotine gum were similar to levels produced by smoking cigarettes. The differential responding determined by route of nicotine administration is discussed and the implications for use of nicotine gum as an adjunct for smoking cessation is addressed.

Avoidance Learning↗
PubMed1989

Effects of d-amphetamine on human aggressive responding maintained by avoidance of provocation.

Male subjects were administered placebo and three doses of d-amphetamine (5, 10 and 20 mg per 70 kg of body weight) under double-blind conditions in a laboratory setting which provided both aggressive and nonaggressive response options. the nonaggressive response was button pressing maintained by the presentation of points which were exchanged for money. The aggressive response was pressing another button which ostensibly resulted in the subtraction of points from a fictitious person. Aggressive responding was initiated by subtracting points from the subject. Point subtractions were attributed to the other person. Aggressive responding was maintained by an avoidance contingency between aggressive responses and scheduled provoking point subtraction presentations. d-Amphetamine increased nonaggressive responding, while aggressive responding was increased at the 10 mg dose and 20 mg resulted in significant decreases in aggressive responding relative to the 10 mg dose. Comparisons with previous research indicate that the contingency relationship between aggressive responses and presentation of provoking point subtractions can alter the effects of d-amphetamine on aggressive responding.

Adolescent↗
PubMed1989

Menstrual cycle and cigarette smoking behavior.

Female cigarette smokers participated in daily two-hour sessions over at least two consecutive menstrual cycles. Automated measurements of each cigarette puff and its duration were recorded. Comparisons in these measurements were between premenstrual and menstrual portions and the rest of the cycle. Most of the subjects increased the mean number of cigarette puffs per session and/or the total puff duration per session during the menstrual phase of the cycles.

Adolescent↗
PubMed1989

Effects of secobarbital on human aggressive and non-aggressive responding.

This study examined the effects of secobarbital on human aggressive responding in a controlled laboratory setting. Sixty minutes prior to experimental sessions, male subjects were administered either placebo or 50, 100 or 200 mg per 70 kg of body weight doses of secobarbital double-blind. During these sessions, subjects could press a button to accumulate points exchangeable for money (non-aggressive response) or press another button ostensibly to subtract points from a fictitious person (aggressive response). Aggressive responding was occasioned by subtracting points from the subject. Subjects were instructed that points were subtracted by another person. Aggressive responding was maintained by contingent presentation of periods free of point subtractions, i.e., provocations. Acute secobarbital administration produced dose-dependent decreases in non-aggressive responding, and increases in aggressive responding.

Aggression↗
PubMed1989

Concurrent reinforcement and alcohol: interactive effects on human aggressive behavior.

The relationship between alcohol and human aggressive behavior was studied under conditions in which nonaggressive response requirements maintained by point presentation were manipulated. Six normal adult male recreational alcohol users pressed buttons that produced points (redeemable for money) on their own counters or ostensibly subtracted points (money) from another fictitious subject described as participating in the same study at another location. During random components of each session, subjects were required to press a button 50, 200 or 500 times in order to produce point increments on their own counters. Ten responses on a second button were required to subtract a point from the other subject during all components. Aggressive responding was engendered by occasional point subtractions which were attributed to the fictitious subject. Alcohol (0, 0.125, 0.25 and 0.5 g/kg of 95% ethanol) produced dose-related increases in aggressive responding. Aggressive responding was also significantly related to the concurrent schedule of point presentation. Finally, a significant interaction between alcohol and concurrent point presentation contingencies was observed. These results indicate that aggressive responding is affected by ongoing reinforcement contingencies not directly related to aggressive behavior and that reinforcement schedule interaction may be one factor mediating the situation-dependent nature of alcohol's effects on aggressive behavior.

Adolescent↗
PubMed1988

Effects of provocation and alcohol on human aggressive behavior.

Effects of provoking stimuli on human aggressive behavior and on the relationship between alcohol and aggressive behavior were measured. Four adult males manipulated pushbuttons that produced points on their own counters (redeemable for money) or ostensibly subtracted points (money) from the counters of fictitious persons described as participating in the same study at other locations. During five 10-min components, frequency and intensity of point subtractions, ostensibly controlled by another person, were manipulated. Each subject was repeatedly exposed to alcohol doses (0.25, 0.5 and 0.75 g/kg of 95% ethanol) over time using a repeated measures design. Aggressive responding was affected by provocation intensity and frequency. The highest dose of alcohol produced selective increases in aggressive responding; however, no interactions between alcohol effects and provocation conditions were observed.

Adult↗
PubMed1987

Effects of d-amphetamine on aggressive responding of normal male subjects.

Male research subjects were administered placebo and three doses of d-amphetamine (5, 10, and 20 mg/70 kg of body weight) under double-blind conditions in a laboratory situation that provided both aggressive and nonaggressive response options. The nonaggressive response was button pressing maintained by the presentation of points which were exchanged for money. The aggressive response was button pressing on a separate manipulandum which ostensibly subtracted points from a fictitious person. Aggressive responding was initially established by subtracting points from the research subjects, which was attributed to the other person. d-Amphetamine increased nonaggressive responding, while aggressive responding was generally decreased.

Adult↗
PubMed1987

Nerve/muscle pedicle graft for bilateral vocal cord palsy.

The nerve-muscle pedicle graft was successfully used in six of the seven patients admitted with bilateral vocal cord palsy. The diagnostic evaluation included bilateral vocal cord palsy for more than six months; passive mobility test of the arytenoids under general anaesthesia; and exclusion of an organic lesion as a cause of the vocal cord paralysis. The post-operative assessment was done by indirect or direct laryngoscopy. An improvement in phonation and respiration was noted 4 to 10 weeks after the operation. An exertional test was performed. Identification of the origin of ansa cervicalis from the hypoglossal nerve facilitated the operation.

Adult↗