PubMed Health⌕ Search

Biomedical subjects

J Schafer

Publications and source records attributed to J Schafer.

14 recordsLinked to original sources
PubMed1992

The relationship between length of stay in drug-free therapeutic communities and neurocognitive functioning.

The relationship between neurocognitive functioning and length of stay in drug-free therapeutic communities (TCs) was investigated. The Wechsler Adult Intelligence Scale (WAIS) was administered to 495 patients admitted to a therapeutic community. It was hypothesized that Digit Symbol and Block Design, which have been found to be more sensitive to diffuse neuropsychological impairment than other WAIS subtests, would be significant predictors of length of stay. A hierarchical regression analysis was performed, and both subtests were found to be predictive of time-in-residence. These findings are congruent with recent investigations that have found a relationship between cognitive impairment and treatment process and outcome in substance abuse treatment.

Adolescent↗
PubMed1992

The treatment of substance abusers diagnosed with obsessive-compulsive disorder: an outcome study.

Sixty substance abusers dually diagnosed with obsessive-compulsive disorder (OCD) and voluntarily admitted to a drug-free therapeutic community were randomly assigned to one of three treatment conditions. One group received a combined intervention that addressed their obsessive-compulsive symptoms and substance abuse; a second group received only substance abuse treatment; and an attention control group received treatment for their substance abuse and training in progressive muscle relaxation. Patients who received treatment for their OCD and substance abuse stayed in treatment longer, showed greater reductions in OCD symptom severity, and had higher overall abstinence rates at 12-month follow-up.

Adult↗
PubMed1991

Marijuana and cocaine effect expectancies and drug use patterns.

Self-reports from 704 college students were content analyzed and used to develop the Marijuana Effect Expectancy Questionnaire and Cocaine Effect Expectancy Questionnaire. Responses were examined using exploratory and confirmatory principle components analysis. Six marijuana expectancies (34.6% of variance) were identified: (a) cognitive and behavioral impairment, (b) relaxation and tension reduction, (c) social and sexual facilitation, (d) perceptual and cognitive enhancement, (e) global negative effects, and (f) craving and physical effects. Five cocaine expectancies (32.5% of variance) consisted of (a) global positive effects, (b) global negative effects, (c) generalized arousal, (d) anxiety, and (e) relaxation and tension reduction. Drug effect expectancies distinguished between patterns of nonuse and varying degrees of use of these two drugs.

Adult↗
PubMed1991

Effect of adenosine and glucagon on hepatic blood volume responses to sympathetic nerves.

Hepatic blood volume responses were studied in cats using in vivo plethysmography. The maximal response (Rmax) to sympathetic nerve stimulation and to infusions of norepinephrine into the hepatic artery or portal vein was similar (12-14 mL expelled per liver in 2.9-kg cats; average liver weight, 76.8 +/- 6.8 g). The ED50 for norepinephrine intraportal (0.44 +/- 0.13) and intrahepatic arterial infusions (0.33 +/- 0.08 micrograms.kg-1.min-1) were similar indicating equal access of both blood supplies to the capacitance vessels. Adenosine (2.0 mg.kg-1.min-1) did not cause significant volume changes but produced a mild (27%) suppression of Rmax due to nerve stimulation with no change in the frequency (3.4 Hz) needed to produce 50% of Rmax. Rmax tended (not statistically significant) to decrease during glucagon (1.0 micrograms.kg-1.min-1) infusion but the nerve frequency needed to produce 50% of Rmax rose to 5.6 Hz. Thus both adenosine and glucagon produced modulation of sympathetic nerve-induced capacitance responses without having significant effects on basal blood volume. Adenosine, by virtue of its marked effects on arterial resistance vessels (at substantially lower doses than those used here) and the relative lack of effect on venous capacitance vessels, may be useful for producing clinical afterload reduction without venous pooling.

Adenosine↗
PubMed1986

A case of ventricular undersensing in the DDI mode: cause and correction.

A case is presented that demonstrates a confusing problem of ventricular undersensing in the DDI pacing mode. Electrocardiographic monitoring of the patient after pacemaker implantation revealed intermittent ventricular channel outputs which appeared to be inappropriate. These occurred a period of time after the intrinsic R wave, equal to the programmed AV interval. This problem was caused by ventricular lead undersensing, which resulted when the patient's intrinsic rate was such that the intrinsic ventricular complex occurred during the ventricular blanking period. The problem was corrected by reprogramming the blanking period.

Cardiac Pacing, Artificial↗
PubMed1985

Growth-plate-chondrocyte profiles and their orientation.

We studied the proximal tibial physes of mice, seven, fifteen, twenty-two, and twenty-eight days old, to define in mathematical terms the changes in cell profile and profile orientation among growth-plate zones and to determine if cell profile and profile orientation change with changes in the rate of growth. Using electron microscopy, we identified five growth-plate zones: the reserve zone, the upper proliferative zone, the lower proliferative zone, the upper hypertrophic zone, and the lower hypertrophic zone. In transverse sections, cell profiles did not change among growth-plate zones and the degree of cell-profile orientation approached zero in all zones. In longitudinal sections, cell profiles and profile orientations differed significantly among zones. Cell profiles in the upper and lower proliferative zones were eccentric and highly oriented. They became more rounded and the degree of cell orientation decreased between the proliferative and hypertrophic zones. As the rate of longitudinal bone growth decreased, cell profiles and cell-profile orientation changed. The cell profiles in the reserve zone became flatter and in the other zones the cell profiles became more rounded. The degree of cell-profile orientation decreased quadratically in the upper and lower proliferative zones, decreased linearly in the reserve and upper hypertrophic zones, and remained unchanged in the lower hypertrophic zone.

Aging↗
PubMed1970

Certifying board.

Explore the source record for details and available documents.

Certification↗
PubMedDate not supplied

Rapid induction of tolerance to the antipunishment effects of ethanol.

Tolerance to ethanol was tested with 24 adult, male, Wistar rats using a modified Geller-Seifter paradigm. This design consisted of three components: an unpunished random interval-30 sec (RI-30) schedule, a time-out period, and a punished plus continuous reinforcement (conflict) schedule. This procedure allowed for a distinction to be made between the sedative and the "anxiolytic" effects of ethanol. Rats were trained on this procedure until response rates stabilized. They were then randomly divided into three groups. One group served as a control group for two experiments. In the first experiment, the test group received ethanol (0.75 g/kg IP) on days 2-8 and saline on days 1 and 9. For the second experiment, the control group received saline and the test group received ethanol three times in one day at three hour intervals. The "anxiolytic" action (defined as an increase in the rate of punished responding or antipunishment effect) was observed to undergo rapid tolerance (by day 4 in experiment one and by the second session in experiment two), while tolerance to the sedative action (defined as a decrease in the rate of unpunished responding) developed more slowly (only by day 7 in experiment one, but by the third session in experiment two). These results suggest that rapid tolerance develops to the "anxiolytic" actions of ethanol and this may have important implications for the development of ethanol abuse.

Animals↗
PubMedDate not supplied

Picrotoxinin receptor ligand blocks anti-punishment effects of alcohol.

Ethanol at low doses produces a release of punished responding in an operant rat conflict test similar to that observed for benzodiazepines and phenobarbital. It has been hypothesized that these anti-punishment effects are mediated via the GABA-benzodiazepine receptor-ionophore complex but not at the benzodiazepine binding site. In the present study isopropylbicyclophosphate (IPPO), which binds at the picrotoxinin site, reversed the release of punished responding produced by ethanol, pentobarbital and chlordiazepoxide; at low doses IPPO (less than 10 micrograms/kg) appeared to be most effective against ethanol but at higher doses (greater than 15 micrograms/kg) was also effective against pentobarbital and chlordiazepoxide. At still higher doses IPPO produced a decrease in punished and unpunished responding. These results suggest that the "anxiolytic" actions of ethanol may involve a direct action on the GABA-benzodiazepine receptor-ionophore complex and this action may underlie some of the intoxicating effects of ethanol.

Animals↗
PubMedDate not supplied

A sleeping giant.

Explore the source record for details and available documents.

Dental Assistants↗