Search PubMed⌕ Search

Biomedical subjects

R F Kaplan

Publications and source records attributed to R F Kaplan.

At least 55 records · Page 3Linked to original sources
PubMed1990

Giving ethanol to alcoholics in a research setting: its effect on compliance with disulfiram treatment.

In order to evaluate the effect of experimental ethanol administration on disulfiram compliance, a 6-month follow-up study was conducted with inpatient alcoholics. Two groups of patients were studied. Though not randomly assigned, the groups were matched on a variety of demographic and alcoholic-related variables. One group (N = 15) received ethanol in a laboratory-based study while the other group (N = 21) underwent treatment as usual. Days of disulfiram use did not differ between groups at follow-up. Studies concerning compliance with disulfiram support the validity of this measure as an indicator of treatment outcome. Our findings are consistent with other studies of the effect of experimental administration of ethanol to alcoholics, in that there were no immediate adverse effects and treatment outcome did not appear to suffer as a consequence of ethanol exposure.

Adult↗
PubMed1990

Effects of changes in stimulus contingency on visual extinction.

Left visual field (LVF) extinction during double simultaneous stimulation (DSS) is common in patients with right cerebral lesions. A postulate is that during DSS, the intact left hemisphere's limited attentional capacity is directed to right hemispace, resulting in LVF extinction. External cueing may help direct attention to the LVF and improve performance. In the present study, we varied patterns of unilateral stimulation preceding DSS in an attempt to redirect attention through expectancy. Nine patients (7 stroke, 2 tumor) with right hemisphere lesions each had 40 DSS trials with the distribution of unilateral stimulation trials systematically varied. Mean extinction percentages on DSS trials were 17% following 5 right unilateral trials, 30% following 1 right unilateral trial, 52% following 1 left unilateral trial, and 63% following 5 left unilateral trials. These findings indicate that the probability of extinction decreases following unilateral stimulation to the right visual field and increases following unilateral stimulation to the LVF. These results suggest that expectancy alters the attentional bias which mediates extinction.

Adult↗
PubMed1988

Behavioral and EEG responses to alcohol in nonalcoholic men with a family history of alcoholism.

1. Behavioral and EEG responses were examined in nonalcoholic males with (FH+) and without (FH-) a family history of alcoholism following the consumption of a placebo and real beer. 2. FH+ subjects were less confident of being able to resist another drink following consumption of the placebo and reported higher taste ratings and feeling more intoxicated immediately following ethanol consumption than FH- subjects. 3. Both groups showed increases in EEG alpha activity (9-12Hz) following alcohol consumption. 4. Alpha activity was positively associated with desire to drink in the FH+ group before and after consumption, but was positively associated with perceived intoxication in the FH- group only after consumption.

Adult↗
PubMed1987

Neuroendocrine, psychophysiological and subjective reactivity to an alcohol placebo in male alcoholic patients.

Alteration in neuroendocrine activity associated with the regulation of energy metabolism and food intake may play a role in characterizing the alcohol dependent state. Alcoholics, when compared to controls, demonstrated significantly larger and more rapid glucose and insulin responses following the consumption of a placebo beer, which they believed contained alcohol. The existence of significant correlations between peak neuroendocrine responses and desire to drink, anxiety, as well as psychophysiological responses in alcoholics suggests the potential multivariate nature of the biological/behavioral state associated with alcohol dependence.

Adult↗
PubMed1985

Power and coherence analysis of the EEG in hospitalized alcoholics and nonalcoholic controls.

EEG recordings from 56 alcoholics (20 women) and 9 nonalcoholic controls (15 women) were compared using power spectral density and coherence techniques. Alcoholics had more power in the delta frequency bands (1-4 Hz) and less power in alpha (9-13 Hz) from all regions of the skull. Interhemispheric coherence scores from homologous brain sites were greater for alcoholics in the delta band (1-4 Hz) but greater for nonalcoholics in the higher frequencies. Among alcoholics, power in the alpha bandwidth was positively correlated with Brain Age Quotient (BAQ) scores, whereas delta power was inversely related to BAQ scores. Increased power in the beta frequencies (14 + Hz) among alcoholics was a function of the time elapsed since the last drink and the use of chlordiazepoxide during detoxication. Issues relating to transient brain dysfunction in recently abstaining alcoholics are also discussed.

Adult↗
PubMed1985

Reactivity to alcohol-related cues: physiological and subjective responses in alcoholics and nonproblem drinkers.

Physiological reactivity and self-reported desire to drink in nonproblem drinkers (N = 11 women and 15 men) and hospitalized alcoholics (N = 25 women and 34 men) were examined while subjects held and sniffed their preferred alcoholic beverage. Skin conductance level (SCL) and heart rate during alcohol exposure were significantly higher in the alcoholics than in the non-alcoholics. Self-reported desire to drink and SCL during alcohol exposure were correlated for alcoholics but not for nonalcoholics. Among alcoholics, SCL change was positively correlated with the number of heavy-drinking days in the month preceding admission to treatment. Consistent with conditioning models of relapse, alcoholics showed a distinctive response to alcohol cues, characterized by autonomic reactivity and concordance between this reactivity and self-reported desire for alcohol.

Adult↗
PubMed1983

Metocurine requirements and plasma concentrations in burned paediatric patients.

A cumulative dose-response study for metocurine was performed on 11 burned and 11 non-burned children during thiopentone, nitrous oxide in oxygen and narcotic anaesthesia. Burned children required a significantly (P less than 0.001) greater dose (three-fold) of metocurine to achieve a given degree of neuromuscular blockade compared with non-burned children. For the same degree of twitch depression, burned children required twice the plasma concentration of metocurine. Despite the larger dose, the recovery time for the twitch was not significantly different in the two groups. It is speculated that there may be fundamental changes at the neuromuscular junction of burned children to account for their resistance to the effect of non-depolarizing neuromuscular blockers.

Anesthesia, General↗
PubMed1983

Halothane-induced ATP depletion in platelets from patients susceptible to malignant hyperthermia and from controls.

Since the cellular defect of malignant hyperthermia (MH) may occur in tissues other than muscle and since platelets share certain contractile characteristics with muscle cells, testing platelets has been suggested as a way to diagnose susceptibility to MH. In analogy to the in vitro depletion of muscle adenosine triphosphate (ATP), the authors compared platelet basal nucleotide levels and halothane-induced depletion of ATP from 10 MH-susceptible patients and from 12 unrelated nonsusceptible controls. A rapid and simple isocratic high-pressure liquid chromatography technique was used to analyze acid-extracted platelet nucleotides. Halothane added to platelet-rich plasma at 37 degrees C significantly decreased ATP in platelets in a dose-dependent as well as a time-dependent manner. In contrast, adenosine diphosphate (ADP) and adenosine monophosphate (AMP) were not changed significantly. Other volatile anesthetic agents also depleted ATP in platelets. Although ATP in platelets exposed to halothane was depleted significantly, there was no difference between platelets from MH-susceptible patients and nonsusceptible controls. Therefore, halothane-induced ATP depletion in platelets is not a reliable test for diagnosing MH susceptibility.

Adenosine Diphosphate↗