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Biomedical subjects

S E Taylor

Publications and source records attributed to S E Taylor.

At least 19 recordsLinked to original sources
PubMed1992

Tracer kinetic evidence for abnormal methyl metabolism in schizophrenia.

The original transmethylation hypothesis of schizophrenia has evolved with time and experiment to the present concept that a defect in the methyl-carbon metabolic pathway may be causative in this illness. Various researchers have proposed that specific steps in the methyl-carbon pathway may be defective, and have presented evidence to support these possibilities. We have tested the general concept of the hypothesis by administering methionine labeled with 11C or 14C in the S-methyl carbon to patients with schizophrenia and to controls and measured the expiration of 11CO2 and 14CO2. We found that the rate and total expiration of labeled CO2 were three times less in the patients than in the controls, with no overlap of data points in the two groups. Specific steps in the methylcarbon pathway that might be defective and produce the results seen here are discussed in light of this and other researchers' findings.

Adult↗
PubMed1992

Carbachol potentiates isoprenaline-induced mucin secretion by rat submandibular gland.

We studied the effects of carbachol on isoprenaline-induced secretion of 3[H]glucosamine-labeled high molecular weight protein from in vitro fragments of rat submandibular gland. The concentration-response curve for isoprenaline was determined alone and in the presence of one of two concentrations of carbachol. Isobolic interaction indices were calculated from the resulting curves. The role of extracellular calcium on this interaction was assessed by examining the effect of increasing concentrations of [Ca2+]e on secretion induced by a fixed concentration of isoprenaline alone and in the presence of carbachol. Carbachol alone caused a small, but statistically significant, protein secretion. Carbachol markedly shifted the isoprenaline concentration-response curve to the left in a dose-dependent manner. In the absence of extracellular calcium, carbachol did not increase isoprenaline-induced secretion, but secretion increased as the [Ca2+]e was increased. The carbachol-induced increase in secretion reached a maximal level at approximately 2.0 mM [Ca2+]e. We conclude that carbachol's increase of isoprenaline-induced secretion of 3[H]glucosamine-labeled high molecular weight protein is not additive, but is true potentiation. This potentiation requires extracellular calcium, and may be maximal at physiological [Ca2+]e.

Animals↗
PubMed1992

Optimism, coping, psychological distress, and high-risk sexual behavior among men at risk for acquired immunodeficiency syndrome (AIDS).

In a cohort of gay men responding to the threat of acquired immunodeficiency syndrome (AIDS), dispositional optimism was associated with less distress, less avoidant coping, positive attitudes as a coping strategy, and fewer AIDS-related concerns. Men who knew they were seropositive for human immunodeficiency virus (HIV) were significantly more optimistic about not developing AIDS than men who knew they were seronegative for HIV. This AIDS-specific optimism was related to higher perceived control over AIDS and to active coping among seropositive men only and to health behaviors in both serostatus groups. There was no relation of optimism to risk-related sexual behavior. It is concluded that optimism is psychologically adaptive without necessarily compromising health behavior. It is also concluded that it is useful to distinguish between event-based optimistic expectations and dispositional optimism.

AIDS Serodiagnosis↗
PubMed1992

Modeling cognitive adaptation: a longitudinal investigation of the impact of individual differences and coping on college adjustment and performance.

Drawing on cognitive adaptation theory, optimism, psychological control, and self-esteem were explored as longitudinal predictors of adjustment to college in a sample of 672 freshmen. Although a direct effect of optimism on adjustment was found, most of the predicted effects were mediated by coping methods. Controlling for initial positive and negative mood, the beneficial effects of optimism, control, and self-esteem on adjustment were mediated by the nonuse of avoidance coping, greater use of active coping, and greater seeking of social support. Alternative models of the causal relations among these variables did not fit the data as well as the a priori mediational model. The results of a 2-year follow-up indicated that self-esteem and control predicted greater motivation and higher grades, controlling for college entrance exam scores. Implications for cognitive adaptation theory and for interventions with populations under stress are discussed.

Achievement↗
PubMed1992

Patterns of coping with cancer.

We identified five patterns of coping in a sample of 603 cancer patients: "seeking or using social support," "focusing on the positive," "distancing," "cognitive escape-avoidance," and "behavioral escape-avoidance." Relationships of these coping patterns to sociodemographic characteristics, medical factors, stress appraisals, psychotherapeutic experience, and emotional distress were tested using correlational and regression techniques. Type of cancer, time since diagnosis, and whether a person was currently in treatment had few or no relationships to coping. The specific cancer-related problem (e.g., pain, fear of future) was also not associated with how individuals coped. Perceptions of its stressfulness, however, were related to significantly more coping through social support and more of both forms of escape-avoidance. Coping through social support, focusing on the positive, and distancing was associated with less emotional distress, whereas using cognitive and behavioral escape-avoidance was associated with more emotional distress. Implications of the results for understanding coping processes and intervention with cancer patients are discussed.

Adaptation, Psychological↗
PubMed1992

Binding potency of paroxetine analogues for the 5-hydroxytryptamine uptake complex.

The in-vitro inhibition constants (Ki) of 14 structural analogues of the potent 5-hydroxytryptamine (5-HT)-uptake inhibitor paroxetine were determined to assess the structure-affinity relationship of these derivatives. A goal of these studies was to determine those positions on paroxetine which could be derivatized without significantly decreasing the affinity of the drug for the binding site, so that radiolabels such as [18F]fluoroalkyl groups might be appended for future in-vivo imaging studies of the 5-HT uptake system. Using the methyl moiety as a steric probe for these studies, it was found that the rank order of potency of various methyl-substituted paroxetine analogues for inhibiting the binding of [3H]paroxetine to the 5-HT re-uptake site was: 4'-approximately equal to 3'-approximately equal to 2''- > 2'-approximately equal to 1- > 5''- > 6''-methyl. The in-vitro equipotent molar ratios (EPMR, Ki(analogue)/Ki(paroxetine)) of the analogues were determined, and the EPMRs of the 4'-, 3'-, and 2''-methyl derivatives were 1.9, 2.2 and 2.2, respectively. The 4'- and 2''-fluoromethyl and -fluoroethyl analogues were synthesized, and the EPMRs of the 4'- and 2''-fluoromethyl derivatives were determined to be 2.0 and 3.5, and those of the 4'- and 2''-fluoroethyl analogues were 5.2 and 6.2, respectively. The 2''-fluoromethyl analogue was unstable in aqueous solutions, and it is not a promising ligand for in-vivo studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effects of a multidimensional cardiopulmonary rehabilitation program on psychosocial function.

The effects of participation in a structured, outpatient cardiac rehabilitation program on psychosocial function after acute myocardial infarction or coronary artery bypass surgery, or both, were evaluated prospectively in 141 patients who were married or living with "a significant other" (89% men, mean [+/- standard deviation] age 63 +/- 9 years old). Forty-one patients who were participants in a 3-month cardiac rehabilitation program were compared with 100 patients who did not participate in a formal program. On average, patients in both groups were well educated, older Caucasians who had minimal cardiac dysfunction (New York Heart Association class I or II). Patients in the 2 groups were not different at baseline in sociodemographic or clinical characteristics or in any of the dependent measures of anxiety, depression, psychosocial adjustment to illness or marital adjustment. Six months after initial testing, patients who attended cardiac rehabilitation were significantly less anxious (F[1,139] = 5.09, p = 0.03), less depressed (F[1,139] = 8.39, p = 0.004), had better psychosocial adjustment (F[1,139] = 5.87, p = 0.02), and were more satisfied with their marriages (F[1,139] = 8.6, p = 0.004) than nonparticipants. The findings support the effectiveness of group cardiac rehabilitation for this subgroup of patients in facilitating their psychosocial recovery after an acute cardiac event.

Adult↗
PubMed1991

Factor influencing suicide intent in gay and bisexual suicide ideators: differing models for men with and without human immunodeficiency virus.

Of 778 gay and bisexual men (none with acquired immunodeficiency syndrome [AIDS]), 27% (n = 212) reported suicidal ideation over the previous 6 months. Covariance structure models were used to explore predictors of suicide intent among (n = 112) suicide ideators with (n = 100) and without (n = 112) human immunodeficiency virus (HIV). Current AIDS-related stressors (deaths and illnesses and perceived AIDS risk) and past levels of adaptive functioning (social isolation and depression) were significantly more powerful predictors of suicide intent among HIV-positive than among HIV-negative ideators. Biological AIDS risk predicted neither suicide intent, current distress, nor perceived AIDS risk. Pathways to suicide intent appear to be psychologically, rather than biologically, mediated. Among HIV-positive ideators, AIDS-related death and illness events predicted suicide intent but not current distress symptoms. Some suicidal ideation in response to AIDS-related events may be an effort to cope rather than a manifestation of psychological distress.

Adaptation, Psychological↗
PubMed1991

Psychosocial predictors of gay men's AIDS risk-reduction behavior.

Used psychosocial variables derived from the health belief model (Rosenstock, 1974), Bandura's (1986) self-efficacy framework, and protection motivation theory (Rogers, 1984) to predict self-reported AIDS risk-reduction behaviors in a sample of 389 homosexual men who participated in the Multicenter AIDS Cohort Study in Los Angeles and who knew their HIV antibody status. Hierarchical multiple regression analyses showed that self-efficacy, perceived risk, response efficacy, and prior sexual behavior accounted for approximately 70% of the variance in the total number of sexual partners and the number of anonymous partners over a 6-month interval, controlling for demographic variables, HIV antibody status, and presence of a primary partner. A logistic regression analysis showed that barriers to change predicted increased unprotected anal receptive intercourse over a 6-month interval, controlling for prior behavior. The relation of health beliefs to risk-reduction behavior was substantially different for HIV-seropositive men without primary partners than for other groups of gay men. Implications for interventions are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Asymmetrical effects of positive and negative events: the mobilization-minimization hypothesis.

Negative (adverse or threatening) events evoke strong and rapid physiological, cognitive, emotional, and social responses. This mobilization of the organism is followed by physiological, cognitive, and behavioral responses that damp down, minimize, and even erase the impact of that event. This pattern of mobilization-minimization appears to be greater for negative events than for neutral or positive events. Theoretical accounts of this response pattern are reviewed. It is concluded that no single theoretical mechanism can explain the mobilization-minimization pattern, but that a family of integrated process models, encompassing different classes of responses, may account for this pattern of parallel but disparately caused effects.

Adaptation, Psychological↗
PubMed1991

Synthesis of abnormal immunoglobulins by hybridomas from autoimmune "viable motheaten" mutant mice.

Secretory defects in abnormal plasma cells, called Mott cells, that appear in lymphoid tissues of spontaneously autoimmune, "viable motheaten" (mev/mev) mice lead to deposition of immunoglobulin in RER-bound vesicles. Such vesicles have been termed Russel bodies. Cells with Russel bodies can also be observed rarely in normal animals, usually as a result of extreme antigenic loads or pathologic states. To understand why these abnormal cells appear commonly in mev/mev mice, we have established a panel of hybridomas that contain Russell bodies. Using immunochemical analysis and immunoelectron microscopy, we have characterized the secretory defects. Although these hybridoma cells synthesize a normal size heavy chain and it associates with light chain, the Russell bodies have many characteristics of inclusion bodies, which commonly appear in cells synthesizing mutant proteins and often are associated with incompletely or abnormally folded proteins. Pulse-chase experiments showed that immunoglobulins synthesized by these hybridomas accumulate rapidly into insoluble complexes and have an intracellular half life approximately 10 time greater than normal immunoglobulins. The defect affected only the immunoglobulin derived from the mev/mev mice and did not affect the secretion of normal immunoglobulin produced by an IgG1-secreting fusion partner. In addition to accumulating intracellular immunoglobulins, many mutant cell lines also secreted immunoglobulin. Endoglycosidase H digestion was used to determine the state of processing of the N-linked carbohydrates on the immunoglobulin molecules. This analysis demonstrated that the N-linked carbohydrates on the secreted immunoglobulin were resistant to endoglycosidase H digestion, indicating that they were processed normally. The insoluble IgM molecules were sensitive to endoglycosidase H, which is consistent with their localization to the RER. We propose several models by which these abnormal immunoglobulin-secreting cells commonly appear in this autoimmune mutant mouse.

Acetylglucosaminidase↗
PubMed1991

AIDS-related factors predictive of suicidal ideation of low and high intent among gay and bisexual men.

AIDS-related stressors were studied in relationship to suicidal ideation and suicide intent among 778 gay and bisexual men (none with AIDS). Over the previous six months, 27% (n = 212) reported suicidal ideation. Subjects who reported suicidal ideation (compared to those who did not) were more likely to report recent (last 6 months) bereavement of partner, recent ARC diagnosis, and multiple close friends with ARC. Suicide ideators were divided by a median split on a self-report scale of suicide intent into low (n = 105) and high (n = 107) intent suicide ideators. News of HIV seropositivity was specifically related to low intent suicidal ideation. High intent suicidal ideation was associated with having a partner with AIDS or ARC, or multiple close friends with AIDS, or having ARC. Generally speaking, while temporally discrete AIDS-related events were associated the report of suicidal ideation, ongoing stressors which may more greatly challenge adaptational capacities were more associated with high intent suicidal ideation.

AIDS Serodiagnosis↗
PubMed1991

Adrenergic interaction in mucin secretion of rat submandibular gland in vitro.

Previous studies have reported that maximally effective concentrations of the "mixed" alpha and beta adrenoceptor agonists, epinephrine and norepinephrine, cause greater amounts of mucin secretion than the "pure" beta adrenoceptor agonist, isoproterenol, and that this response requires extracellular calcium. The purpose of the present study was to examine directly the nature of the effect of the putative pure alpha adrenoceptor agonist, phenylephrine, on isoproterenol-induced mucin secretion and the role of extracellular calcium in this interaction. We used a graphical method which provides a procedure for determining whether interaction between two drugs is additive, antagonistic or synergistic to analyze this interaction. Submandibular glands were removed from male rats, divided into sections and placed in modified Hank's balanced salt solution. Mucin secretion was measured as acid precipitable disintegrations per minute after labeling the submandibular gland with [14C]glucosamine. Phenylephrine caused a small but significant secretion of mucin which was blocked partially by phentolamine and completely by propranolol. Phenylephrine caused a significant shift of the isoproterenol concentration-response curve to the left of the theoretical curve expected if two drugs act additively. Mucin secretion induced by isoproterenol alone was independent of extracellular calcium concentration; however, the combination of isoproterenol and phenylephrine caused a concentration-dependency on extracellular calcium.

Animals↗
PubMed1990

Cardiopulmonary resuscitation skills retention in family members of cardiac patients.

The purpose of this study was to determine if the use of a retention strategy would maintain cardiopulmonary resuscitation (CPR) skills in family members of cardiac patients. Thirty-one subjects trained in CPR received retention packets 3 and 6 months after CPR training. Sixteen subjects were tested for CPR retention at 7 months after initial training, and 15 at 12 months. Likelihood chi 2 was used to compare the 7- and 12-month groups. There were no differences between the 7- and 12-month groups, because CPR retention overall was poor. Only 19.4% of subjects reported using the retention packet; therefore, subjects were regrouped into practice and no practice groups for purposes of further statistical analysis. There were significant differences in retention in subjects who practiced compared with subjects who did not. These findings underscore the importance of promoting practice/review after initial CPR training for family members of cardiac patients.

Adult↗
PubMed1990

Health psychology. The science and the field.

Reviews scientific and professional trends in the field of health psychology. I discuss recent research on health promotion, psychological factors in the development of illness, cognitive representations of health and illness, stress and coping, social support, interventions to promote coping, and trends that will affect progress in the field, such as the need for cost containment and the aging of the population.

Cognition↗
PubMed1990

Victims' perceptions of social support: what is helpful from whom?

Although research has demonstrated that social interactions influence psychological well-being, little is known about what specific actions victims of stressful life events experience as helpful or unhelpful. Wortman and Dunkel-Schetter (1979) previously suggested that victims frequently experience rejection, withdrawal, and communication problems with those close to them. To address these issues, 55 cancer patients were interviewed concerning the specific actions they found to be helpful or unhelpful from several potential support providers: spouse, other family members, friends, acquaintances, others with cancer, physicians, and nurses. The data indicated that the Wortman and Dunkel-Schetter victimization model applied better to interactions with friends and acquaintances than to interactions with close family members. In addition, support was found to be partially dependent on the source: Particular actions were perceived to be helpful from some but not other network members. Implications for theory and research on social support are discussed.

Adaptation, Psychological↗