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Biomedical subjects

B Fehr

Publications and source records attributed to B Fehr.

12 recordsLinked to original sources
PubMed1999

Laypeople's conceptions of commitment.

The author conducted 8 studies to elucidate the content and structure of lay conceptions of commitment. Studies 1 to 5 revealed that laypeople regard commitment to close relationships (e.g., friends, family, spouse) as central to the concept, whereas they consider nonclose (e.g., commitment to a neighbor) and noninterpersonal varieties (e.g., one's occupation) peripheral. This prototype structure influenced information processing in predictable ways. Studies 6 to 8 focused on the vertical structure of commitment categories. Results suggest that types of commitment are organized as fuzzy rather than true class-inclusion hierarchies. Study 8 also examined relationship implications of conceptions of commitment. People who held a relational conception of commitment had more positive perceptions, thoughts, and feelings about their dating relationship than did those who held a nonrelational conception.

Adolescent↗
PubMed1997

Procoagulant activity of purified protein derivative-stimulated pleural effusion mononuclear cells in tuberculous pleurisy.

Mononuclear cells (MNC) generate cell-bound procoagulant activity (PCA) which shortens recalcification time after incubation with an antigen to which the donor has been sensitized. PCA has been demonstrated in various lung diseases, including exudative pleural effusions. To determine the value of measuring cell-bound PCA in the diagnosis of tuberculous pleural effusions we examined pleural effusion MNC of patients with tuberculosis (n = 19), congestive heart failure (n = 7), and carcinoma (n = 7). MNC were isolated, incubated in 0 or 10 micrograms/ml purified protein derivative (PPD) for 15 min and for 20 h, and recalcification time determined. Incubation with thromboplastin was used as control. The recalcification times in serum incubated for 15 min varied within a wide range, the mean values were longest for tuberculous effusion MNC, incubation for 20 h increased variation. Incubation of cells for 15 min with thromboplastin led to a decrease of mean recalcification time in tuberculous (p < 0.001) and heart failure (p < 0.05), and with no significance in carcinomatous effusions. Incubation with PPD led to decrease of recalcification time which was not significant. Comparisons of the mean relative recalcification times after PPD incubation showed that tuberculosis differed from lung cancer (p < 0.001), lung cancer from heart failure (p < 0.05), but not heart failure from tuberculosis. We conclude from our study that pleural effusion MNC express spontaneous PCA in vitro which is strongest in carcinomatous pleural effusions. Incubation of MNC with thromboplastin and less discernable with PPD leads to an increase in PCA which is more pronounced in tuberculous pleural effusions. However, due to substantial intersubject variability and overlap between the study groups, this test does not allow reliable differentiation of tuberculous from other MNC rich pleural effusions.

Blood Coagulation↗
PubMed1997

Protein extract as a surrogate mother.

Brief dynamic psychotherapy, carried out by an resident in training, can bring significant improvement to a patient who does not necessarily meet ideal selection criteria. S. had experienced early childhood deprivation resulting in adult psychosomatic manifestations of feeling hypoglycemic under pressure of responsibility or during fear of abandonment. He soothed himself with the aid of a bottle of "protein extract," which he carried at all times on his belt. The 21-week therapy resulted in his increased ability to differentiate the sources of his anxiety and allowed him to find new and more mature ways of coping with stress. Although still confronting internal conflicts and anxiety, he relinquished the protein-extract bottle and began to take a more active role in work and relationships. With the help of brief dynamic psychotherapy, this patient was able to start moving forward in his personal growth. Finally, although requiring ongoing supervision and training, resident therapists should be encouraged to treat difficult patients with brief dynamic psychotherapy despite their limited experience with such a promising therapeutic technique.

Adaptation, Psychological↗
PubMed1994

Fuzzy concepts in a fuzzy hierarchy: varieties of anger.

This article argues that the concept of anger is not well characterized from the classical perspective. Instead, its membership is graded, its borders are fuzzy, and its subcategories fail to form a true class-inclusion hierarchy. Ss rated potential anger subcategories (fury, jealousy, annoyance, etc.) and remembered instances of their own anger as varying in degree of membership in anger. Degree of membership (prototypicality) predicted each subcategory's availability from memory given the category name, reaction time to verify its status as a subcategory, and its substitutability within naturally generated sentences about anger. Two predictions of a true class-inclusion hierarchy failed: that Ss would agree in adjudicating the membership of potential subcategories of anger and that all instances of a subcategory of anger would also be instances of anger. As an alternative to the classical view, emotion concepts are hypothesized to vary in their degree of breadth and overlap and to be mentally represented as scripts that allow different instantiations in different contexts.

Anger↗
PubMed1991

Becker's nevus and malignant melanoma.

We describe 9 patients who presented Becker's nevus (BN) together with a malignant melanoma (MM). Eight patients were male. In 5 patients the MM was on the same body site as the BN. The melanoma was of the superficial-spreading type in 7 cases and in 1 patient was within the BN. Twice a dysplastic-nevus syndrome was diagnosed and in 2 patients a familial melanoma. To the best of our knowledge this is the first report of the co-occurrence of BN and MM.

Adult↗
PubMed1990

Self-esteem and perceptions of conveyed impressions: is negative affectivity associated with greater realism?

Two studies examined the notion that negative affectivity (Watson & Clark, 1984) is associated with more accurate perceptions of conveyed impressions in social interactions. In Study 1 (n = 160), low self-esteem (LSE) and high self-esteem (HSE) subjects were paired with either an LSE or an HSE partner. After a 15-min interaction, they rated themselves, their partners, and how they believed their partners would rate them on 20 adjectives related to social competence. Study 2 (n = 40) was identical except that each interaction was observed by 2 observers who rated each participant, and participants also rated how they believed an observer would rate them. LSE subjects exhibited greater accuracy only with respect to the elevation component of observers' ratings; HSE subjects overestimated the positivity of observers' evaluations, whereas LSE subjects were relatively accurate. However, LSE subjects exhibited less overall accuracy with respect to their partners' ratings. We argue that when these results are considered with earlier research, there is no support for the notion of depressive realism in assessing conveyed impressions.

Adult↗
PubMed1985

Atracurium infusion requirements in children during halothane, isoflurane, and narcotic anesthesia.

We were interested in determining the dose-response relationship of atracurium in children (2-10 yr) during nitrous oxide-isoflurane anesthesia (1%) and the atracurium infusion rate required to maintain about 95% neuromuscular blockade during nitrous oxide-halothane (0.8%), nitrous oxide-isoflurane (1%), or nitrous oxide-narcotic anesthesia. Neuromuscular blockade was monitored by recording the electromyographic activity of the adductor pollicis muscle resulting from supramaximal stimulation at the ulnar nerve at 2 Hz for 2 sec at 10-sec intervals. To estimate dose-response relationships, three groups of five children received 80, 100, 150 micrograms/kg atracurium, respectively. During isoflurane anesthesia, the neuromuscular block produced by 80 micrograms/kg was 23.6% +/- 6.5 (mean +/- SEM), by 100 micrograms/kg was 45% +/- 7.2, and by 150 micrograms/kg was 64% +/- 8.7. The ED50 and ED95 (estimated from linear regression plots of log dose vs probit of effect) were 120 micrograms/kg and 280 micrograms/kg, respectively. At equipotent concentrations, halothane and isoflurane augment atracurium neuromuscular block to the same extent, compared to narcotic anesthesia. Atracurium steady-state infusion requirements averaged 6.3 +/- 0.6 micrograms . kg-1 . min-1 during halothane or isoflurane anesthesia; the requirements during balanced anesthesia were 9.3 +/- 0.8 micrograms . kg-1 . min-1 (P less than 0.05). There was no evidence of cumulation during prolonged atracurium infusion.

Anesthesia, General↗
PubMed1984

Carbamazepine decreases catecholamine turnover in the rat brain.

The anticonvulsant carbamazepine (100 mg/kg i.p.) increased the levels of 3-methoxy-4-hydroxyphenylglycol sulfate in the rat brain as well as its accumulation after inhibition of acid transport by probenecid. It did not interfere with 3-methoxy-4-hydroxyphenylglycol sulfation in vivo. However, this was not corroborated by the results of turnover studies. The depletion of brain norepinephrine after inhibition of tyrosine hydroxylase or dopamine (DA) beta-hydroxylase rather tended to be decreased and the accumulation of DA in the rat heart after DA beta-hydroxylase inhibition was diminished. Carbamazepine also reduced the depletion of striatal DA after tyrosine hydroxylase inhibition and the accumulation of striatal dopa after central decarboxylase inhibition, but did not affect the levels of the deaminated DA metabolites, homovanillic acid and 3,4-dihydroxyphenylacetic acid, even after pretreatment with probenecid. Therefore, carbamazepine seems to reduce catecholamine turnover in spite of its enhancing action on the firing of norepinephrine and DA neurons reported in the literature. These apparently paradoxical effects might be explained by an interference with the catecholamine storage mechanism. Two other anticonvulsants, diphenylhydantoin and phenobarbital, in doses approximately equieffective to that of carbamazepine with respect to their anticonvulsant action, showed similar although somewhat weaker effects on DA, but not on norepinephrine turnover. Within the catecholamine hypothesis of affective disorders, the reduction of catecholamine turnover by carbamazepine might explain the reported antimanic and antipsychotic effects in patients.

Animals↗
PubMed1983

The effects of amfonelic acid on 5-HT metabolism in rat brain.

The non-amphetamine stimulant amfonelic acid (AFA), an inhibitor of dopamine (DA) uptake, has been found to increase the levels of tryptophan (TRYP) and 5-hydroxyindoleacetic acid (5-HIAA) in the rat c. striatum, cerebral cortex, and brain stem. Pretreatment with the DA antagonist haloperidol did not affect this action of AFA in the c. striatum, suggesting that it is independent of the effects of this compound on DA neurons. The duration of action of the effect of AFA on TRYP and 5-HIAA appeared to be longer than that of the increase of the striatal DA metabolites homovanillic acid and 3,4-dihydroxyphenylacetic acid. The increased 5-HIAA concentrations seemed only in part be due to a probenecid-like effect of AFA; evidence for an increased 5-HT synthesis, probably related to the increased TRYP concentrations, was also obtained. This biochemical effect of AFA seems to differ from those reported in the literature on amphetamine and other, related stimulating agents. It might be of interest to see whether corresponding behavioural differences between AFA and these agents can be found.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1981

Experimentally induced supersensitivity of neocortical neurons to microiontophoretically administered serotonin.

Central serotonergic fiber systems of the rat were selectively lesioned by intraventricular injection of the neurotoxin 5,7-dihydroxytryptamine (5,7-DHT). At various times thereafter, the sensitivity of rostral cortical neurons to microiontophoretically administered serotonin (5-HT) was compared in groups of lesioned and sham-operated animals pretreated with the 5-HT uptake inhibitor CGP 6085. Twenty-four hours after the injection of 5,7-DHT, at which time the cortical 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) levels were both reduced by 40%, there was no significant difference in the sensitivity of cortical neurons to 5-HT. However, 3 days after such treatment, when the cortical 5-HT and 5-HIAA levels were reduced by 52% and 53% respectively, pronounced supersensitivity to 5-HT was noted. The depressant action of 5-HT on neuronal firing was potentiated with regard to both maximal firing depression and duration of the firing inhibition. A similar potentiation of the 5-HT responses was observed 7 days after lesioning. Supersensitivity thus appears to develop between 1 and 3 days after the injection of 5,7-DHT. Seven days after lesioning, the sensitivity of rostral cortical neurons to gamma-aminobutyric acid was unchanged compared to that observed in sham-operated animals.

5,7-Dihydroxytryptamine↗
PubMed1978

Effects of baclofen and gamma-hydroxybutyrate on rat striatal and mesolimbic 5-HT metabolism.

The effects of D, L-baclofen and gamma-hydroxybutyric acid (GHBA) on endogenous 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in the rat striatum and the mesolimbic area were investigated and compared with their effects on dopamine (DA) concentrations in the same regions. Both baclofen (5-50 mg/kg i.p.) and GHBA (300--1500 mg/kg i.p.) led to dose-dependent increases in the striatal levels of 5-HT and 5-HIAA by up to 200%. Maximal effects of both drugs occurred about 3 h after treatment. Normalization was reached 6 h after GHBA and 16 h after baclofen. The effect of GHBA in the mesolimbic area was qualitatively similar to, but weaker than, its effect in the striatum. Baclofen had little or no effect in the mesolimbic area, the cortex or the brain stem. The two drugs affected striatal 5-HT and DA metabolism similarly. Their effects on the latter are thought to be due to cessation of impulse flow. The effects on striatal 5-HT may be related to more complex phenomena.

Aminobutyrates↗