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Biomedical subjects

S E Taylor

Publications and source records attributed to S E Taylor.

At least 55 records · Page 3Linked to original sources

Social identity and physical health: accelerated HIV progression in rejection-sensitive gay men.

Research linking sensitivity to others and their evaluation of the self to alterations in physiologic function led the authors to examine whether HIV infection might progress more rapidly in gay men who are particularly sensitive to social rejection. Analyses of data from a 9-year prospective study of 72 initially healthy HIV-positive gay men indicated that rejection-sensitive individuals experienced a significant acceleration in times to a critically low CD4 T lymphocyte level, times to AIDS diagnosis, and times to HIV-related mortality (despite control for a variety of potential biobehavioral confounders). Accelerated HIV progression was not observed in rejection-sensitive gay men who concealed their homosexual identity, suggesting that concealment may protect such individuals from negative health effects. Data distinguishing rejection sensitivity from other health-relevant psychosocial characteristics are presented, and possible links to HIV pathophysiology are described.

Adult↗

A stitch in time: self-regulation and proactive coping.

In a conceptual and temporal framework, derived from research on social cognition, social interaction, and stress and coping, the authors analyze the processes through which people anticipate or detect potential stressors and act in advance to prevent them or to mute their impact (proactive coping). The framework specifies five stages in proactive coping: (1) resource accumulation, (2) recognition of potential stressors, (3) initial appraisal, (4) preliminary coping efforts, and (5) elicitation and use of feedback concerning initial efforts. The authors detail the role of individual differences skills, and resources at each stage. They highlight the unique predictions afforded by a focus on proactive coping and the importance of understanding how people avoid and offset potential stressors.

Adaptation, Psychological↗

Health psychology: what is an unhealthy environment and how does it get under the skin?

This review explores the role of environments in creating chronic and acute health disorders. A general framework for studying the nesting of social environments and the multiple pathways by which environmental factors may adversely affect health is offered. Treating socioeconomic status (SES) and race as contextual factors, we examine characteristics of the environments of community, work, family, and peer interaction for predictors of positive and adverse health outcomes across the lifespan. We consider chronic stress/allostatic load, mental distress, coping skills and resources, and health habits and behaviors as classes of mechanisms that address how unhealthy environments get "under the skin," to create health disorders. Across multiple environments, unhealthy environments are those that threaten safety, that undermine the creation of social ties, and that are conflictual, abusive, or violent. A healthy environment, in contrast, provides safety, opportunities for social integration, and the ability to predict and/or control aspects of that environment.

Behavioral Medicine↗

Kinetic analysis of rubidium and thallium as deposited myocardial blood flow tracers in isolated rabbit heart.

Evaluation of myocardial perfusion with tracers such as thallium and rubidium is based on the assumption that tissue tracer content is proportional to flow. The purpose of this study was to evaluate the relationship between flow and tissue tracer content of 201Tl and 83Rb in the isolated perfused rabbit heart. 83Rb (86-day half-life), an isotope that is not used clinically, was used as a subsitute for 82Rb (76-s half-life) to improve the accuracy and precision of data acquisition. The multiple indicator-dilution technique was employed with two independent computational approaches. The first approach explicitly deconvolved 201Tl and 83Rb venous concentration curves by the intravascular reference tracer curve. The second approach used a conventional analysis. Both approaches showed that there was more early washout of 83Rb than 201Tl and that the heart retained 201Tl better than 83Rb within 2 min after isotope introduction. These data indicate that 201Tl is a better perfusion tracer than 83Rb in the isolated rabbit heart.

Animals↗

The psychological consequences of cardiopulmonary resuscitation training for family members of patients at risk for sudden death.

OBJECTIVES: The purpose of this study was to determine psychological consequences of teaching cardiopulmonary resuscitation (CPR) to family members of patients at risk for sudden death. METHODS: Patient-family pairs (n = 337) were randomized into one of four groups: control, CPR only, CPR with cardiac risk factor education, and CPR with a social support intervention. Only family members received CPR training. Data on emotional state and psychosocial adjustment to illness were collected at baseline, 2 weeks, and 3 and 6 months following CPR training. RESULTS: There were no significant differences in the emotional states of family members across the four groups. However, significant differences in psychosocial adjustment and emotional states occurred in patients across treatment groups following CPR training. Patients whose family members learned CPR with the social support intervention reported better psychosocial adjustment and less anxiety and hostility than patients in the other groups. Control patients reported better psychosocial adjustment and less emotional distress than patients in the CPR-only and CPR-education groups. CONCLUSIONS: These findings support tailoring family CPR training so that instruction does not result in negative psychological states in patients. The findings also illustrate the efficacy of a simple intervention that combines CPR training with social support.

Aged↗

Factors affecting events during oxidation of low density lipoprotein: correlation of multiple parameters of oxidation.

The present study shows that copper oxidation of LDL is a tightly-ordered process which can be finely controlled by appropriate selection of duration of oxidation and of concentrations of LDL and copper. Oxidation of LDL (0.1-2.0 mg LDL protein/ml) was carried out by copper catalysis (in the ratio of 2.5 microM Cu2+ to 0.1 mg LDL protein/ml) in phosphate-buffered saline, and was monitored by agarose gel electro-phoresis, gas chromatography (GC), anion exchange fast protein liquid chromatography (FPLC), fluorescence spectroscopy and dynamic light scattering. Analysis of the data showed strong cross correlations between many of the parameters of oxidation. Oxidation was more rapid for lower concentrations than for higher concentrations of LDL, despite the same ratio of copper to LDL being employed. Chemical kinetics analysis of the GC data suggested that 7beta-hydroxycholesterol formation occurred as a first order (or pseudo first order) consecutive reaction to the oxidation of linoleate. The first order rate constants for decomposition of linoleate and production of 7beta-hydroxycholesterol correlated closely with the theoretically-calculated times between collision of LDL particles. LDL particle diameter, measured by dynamic light scattering, increased by ca. 50% over 24 h oxidation, suggesting unfolding of apo B-100. Prolonged oxidation of LDL at low concentration suggested that the radical chain reaction was able to propagate, albeit slowly, on cholesterol after all the polyunsaturated fatty acid was consumed. For higher concentrations of LDL, prolonged oxidation resulted in partial aggregation. These findings are applicable to preparing oxidised LDL with different degrees of oxidation, under controlled conditions, for studying its biological properties.

Arachidonic Acid↗

A comparison of AIDS-related sexual risk behaviors among African-American college students.

This article compares the sexual practices and risk-taking behaviors of African-American male and female college students (n = 649) attending 4-year institutions in a major southeastern metropolitan area. It is a descriptive study of the kinds of practices that put African-American college students at a high risk of contracting the human immunodeficiency virus (HIV). Overall, the reported practices indicate that the college students studied are exposed to risk by certain sexual behaviors, with males reporting significantly higher frequency of risk behaviors than females. The percentages of male students reporting they engage in an array of risky sexual practices (including sex without condoms and anal intercourse) suggest the invulnerability to HIV apparently perceived by this group. Although the students overall adhere to some HIV-preventive behaviors, they also violate important HIV prevention practices. The findings illuminate the need for designing and conveying messages for African-American college students, and particularly for males, that impress the realities of acquired immunodeficiency syndrome (AIDS) as an indiscriminant disease on this group.

Acquired Immunodeficiency Syndrome↗

Presence of two Ca2+ influx components in internal Ca2+-pool-depleted rat parotid acinar cells.

The molecular mechanism(s) involved in mediating Ca2+ entry into rat parotid acinar and other non-excitable cells is not known. In this study we have examined the kinetics of Ca2+ entry in fura-2-loaded parotid acinar cells, which were treated with thapsigargin to deplete internal Ca2+ pools (Ca2+-pool-depleted cells). The rate of Ca2+ entry was determined by measuring the initial increase in free cytosolic [Ca2+] ([Ca2+]i) in Ca2+-pool-depleted, and control (untreated), cells upon addition of various [Ca2+] to the medium. In untreated cells, a low-affinity component was detected with KCa = 3. 4 +/- 0.7 mM (where KCa denotes affinity for Ca2+) and Vmax = 9.8 +/- 0.4 nM [Ca2+]i /s. In thapsigargin-treated cells, two Ca2+ influx components were detected with KCa values of 152 +/- 79 microM (Vmax = 5.1 +/- 1.9 nM [Ca2+]i/s) and 2.4 +/- 0.9 mM (Vmax = 37.6 +/- 13.6 nM [Ca2+]i/s), respectively. We have also examined the effect of Ca2+ and depolarization on these two putative Ca2+ influx components. When cells were treated with thapsigargin in a Ca2+-free medium, Ca2+ influx was higher than into cells treated in a Ca2+-containing medium and, while there was a 46% increase in the Vmax of the low-affinity component (no change in KCa), the high-affinity component was not clearly detected. In depolarized Ca2+-pool-depleted cells (with 50 mM KCl in the medium) the high-affinity component was considerably decreased while there was an apparent increase in the KCa of the low-affinity component, without any change in the Vmax. These results demonstrate that Ca2+ influx into parotid acinar cells (1) is increased (four- to five-fold) upon internal Ca2+ pool depletion, and (2) is mediated via at least two components, with low and high affinities for Ca2+.

Animals↗

Elevated physical health risk among gay men who conceal their homosexual identity.

This study examined the incidence of infectious and neoplastic diseases among 222 HIV-seronegative gay men who participated in the Natural History of AIDS Psychosocial Study. Those who concealed the expression of their homosexual identity experienced a significantly higher incidence of cancer (odds ratio = 3.18) and several infectious diseases (pneumonia, bronchitis, sinusitis, and tuberculosis; odds ratio = 2.91) over a 5-year follow-up period. These effects could not be attributed to differences in age, ethnicity, socioeconomic status, repressive coping style, health-relevant behavioral patterns (e.g., drug use, exercise), anxiety, depression, or reporting biases (e.g., negative affectivity, social desirability). Results are interpreted in the context of previous data linking concealed homosexual identity to other physical health outcomes (e.g., HIV progression and psychosomatic symptomatology) and theories linking psychological inhibition to physical illness.

Adaptation, Psychological↗

Causal attributions predict rate of immune decline in HIV-seropositive gay men.

Research has suggested that attributions-the perceived causes of events-may affect psychological and physical health and the immune system. The authors hypothesized that attributions reflecting negative beliefs about the self, the future, and control would affect helper T cell (CD4) decline and onset of AIDS in individuals with HIV, either directly or through associations with psychological states such as depression. HIV+ gay men (N = 86) participated in a structured interview from which causal attributions were extracted and coded. Attributing negative events to aspects of the self significantly predicted faster CD4 decline over 18 months following the interview, controlling for potential psychological, behavioral, social, and health mediators such as depression and health behavior. However, attributions did not predict AIDS diagnosis during the study period. The results support the idea that causal attributions related to beliefs about the self may have an influence on the immune system.

Adult↗

Positive illusions and coping with adversity.

We review the literature showing that positive illusions (i.e., self-aggrandizement, unrealistic optimism, and exaggerated perceptions of control) are common and associated with successful adjustment to stressful events, including conditions of extreme adversity. Using theory and recent data, we offer a basis for integrating positive illusions with the constraints of reality. We explicitly contrast the social psychological model of positive illusions with a personality viewpoint that addresses the question "Do higher levels of positive illusions predict higher levels of adjustment?" These issues are explored in the context of people coping with an array of normal stressful events, as well as those coping with more extreme stressful events, including cancer, heart disease, and HIV infection.

Adaptation, Psychological↗

Iodine-123-5-iodo-6-nitroquipazine: SPECT radiotracer to image the serotonin transporter.

UNLABELLED: Because serotonergic function has been implicated in the pathophysiology of a number of diseases of the nervous system, efforts to image this system in vivo have received considerable recent attention. Promising preliminary results with the tracer 5-iodo-6-nitroquipazine (INQUIP) have prompted us to perform further studies designed to validate the use of the tracer as an in vivo ligand for the serotonin transporter. METHODS: We studied six adult macaca mulatta in eight experiments which involved SPECT imaging at 17 to 24 hr post-tracer injection, including three experiments with coinjection of the 123I-and 125I-radiolabeled tracer for direct comparison of autoradiography and SPECT, and three experiments in which animals were lesioned with the serotonergic neurotoxin (+/-)3,4-methyl-enedioxymethamphetamine (MDMA). In addition, we evaluated the metabolism of the tracer in the brain and periphery. RESULTS: SPECT images obtained at 17 and 24 hr reflected the known pattern of distribution of serotonin transporters and also showed close correspondence to the autoradiograms. Ratios of binding in the brain-stem to binding in the cerebellum were close to 3 at 17 hr. autoradiograms from an MDMA-treated animal showed up to 95% reductions of binding, while the SPECT data showed smaller reductions. Virtually all of the tracer in the brain stem was in the form of unmetabolized parent compound, but plasma showed rapid peripheral metabolism of the tracer. CONCLUSION: These results demonstrate that INQUIP SPECT images are sensitive measures of in vivo binding to the serotonin transporter, and support the further development of the tracer as a method for the in vivo study of serotonergic neurons in humans.

Animals↗

Pilocarpine, an old drug; a new formulation.

This article is intended to familiarize dental practitioners with a new drug preparation, Salagen, which is specifically indicated for treatment of dry mouth. Salagen, an oral form of the drug pilocarpine, is a parasympathetic agonist which causes widespread effects on many vital tissues and organs, including the heart, blood vessels, smooth muscle, and exocrine glands. The safety and efficacy of pilocarpine relies greatly on the accurate diagnosis of the underlying cause of dry mouth and an understanding of its mechanism of action. The purpose of this article is to provide dental practitioners with a brief review of the physiology of salivary secretion and the pharmacology of pilocarpine, including its mechanism of action. It is hoped that this information will provide a better understanding of the appropriate use of this medication.

Administration, Oral↗

Lipids and oxidised lipids in human atherosclerotic lesions at different stages of development.

Lipids and oxidised lipids were analysed by GC and GC-MS in human necropsy samples of normal artery and individual atherosclerotic lesions, from aorta and common carotid artery, including fatty streaks, intermediate lesions and advanced lesions. Age-related increases were seen for linoleate, oleate and cholesterol in normal artery, but not in lesions. Each category of lesion was much richer than normal artery in all the lipids measured and in oxidised lipids (oxysterols and hydroxyoctadecadienoic acids), although a degree of overlap existed between the compositions of the various categories of lesion. 26-Hydroxycholesterol and 7 beta-hydroxycholesterol levels were extremely low or undetectable in normal artery, but significantly higher in each of the categories of lesions. The generally wide variation in lipid composition of individual lesions within each category, and the fact that a few individual lesions showed no detectable 26-hydroxycholesterol or 7 beta-hydroxycholesterol, suggested that the lipid oxidation in lesions and therefore perhaps the progression of lesions may be intermittent. Fatty streaks showed the highest concentration of 7 beta-hydroxycholesterol relative to cholesterol, and the lowest ratio of linoleate to oleate, suggesting that this type of lesion experiences the greatest concentration of free radical activity. Levels of the enzymatic product 26-hydroxycholesterol were approximately proportional to cholesterol in all the categories of lesions. 26-Hydroxycholesterol was significantly more abundant in advanced lesions than in intermediate lesions or fatty streaks. 26-Hydroxycholesterol levels were higher in macrophage-rich intermediate and advanced lesions than in their fibrous counterparts. This distinction between macrophage-rich and fibrous lesions was also true for most of the other lipid components, consistent with the involvement of macrophages in lipid accumulation, lipid oxidation and lesion development.

Aging↗

Effects of mindset on positive illusions.

S. E. Taylor and J. D. Brown's (1988) position that mentally healthy people exhibit positive illusions raises a dilemma: How do people function effectively if their perceptions are positively biased? Using Gollwitzer's deliberative-implemental mindset distinctiion, we assessed whether people in a deliberative mindset show less evidence of positive illusions than people in an implemental mindset. Participants completed a mindset task and assessments of mood, self-perceptions, and perceived (in)vulnerability to risk. Deliberation led to worsened mood, greater perceived risk, and poorer self-perceptions, relative to implementation; control (no mindset) participants typically scored in between. Study 3 demonstrated that the mindset manipulation corresponds to how people actually make decisions or implement them. Results suggest that people use relatively realistic thinking when setting goals and more positive thinking when implementing them.

Adolescent↗

Self-evaluation processes: motives, information use, and self-esteem.

At least three motives guide self-evaluation: accuracy, self-enhancement, and self-improvement. To satisfy these motives, self-evaluation may utilize different information sources. Self-esteem may also moderate self-evaluation strategies. Participants evaluated the frequency and usefulness of eight types of information for meeting the three motives in two life domains: academics and social life. Personal standards information was reported to be used more frequently than objective or social comparison information and also perceived as most useful for meeting all three motives. Individuals low in self-esteem reported using more social comparison information than those high in self-esteem, especially upward social comparison information. Individuals with high self-esteem reported using personal standards information more often than they used social comparison information, while individuals with low self-esteem relied equally often on these two types of information. Discussion focuses on the role social comparison information may have for those with unstable self-concepts.

Adolescent↗

Macrophages, lipid oxidation, ceroid accumulation and alpha-tocopherol depletion in human atherosclerotic lesions.

Necropsy samples of atherosclerotic lesions of different histological stages have been analysed. Ceroid was present in all the lesions, within lipid-laden macrophage foam cells and extracellularly in the atheromatous core of advanced lesions. Mean levels of 7 beta-hydroxycholesterol, 26-hydroxycholesterol and hydroxyoctadecadienoic acids were all significantly greater in lesions than in normal intima. Levels of hydroxycholesterols were very low or undetectable in normal intima. Fatty streaks showed the highest ratio of 7 beta-hydroxycholesterol to cholesterol, and the lowest ratio of linoleate to oleate, suggesting that this type of lesion experiences the greatest free radical activity. Levels of 26-hydroxycholesterol, a product of the cytochrome P-450 enzyme sterol 26-hydroxylase, and the ratio of 26-hydroxycholesterol to cholesterol were significantly higher in advanced lesions than in intermediate lesions or fatty streaks. The ratio of alpha-tocopherol to cholesterol levels varied widely in normal intima but was consistently low in lesions, especially those rich in macrophage foam cells, suggesting that oxidative activity in the lesion may lead to significant oxidation of the lesion constituents only after alpha-tocopherol has been depleted. Macrophage death was a characteristic feature of advanced lesions, with apoptotic bodies present, and occasionally, intact apoptotic cells were seen in lesions. These striking correlations between macrophages, lipid oxidation, alpha-tocopherol depletion, ceroid accumulation, and macrophage death in advanced lesions, strongly support a role for oxidative damage in atherosclerosis, and lend credence to the idea that alpha-tocopherol dietary supplementation may slow the progression of atherosclerosis in humans.

Aorta, Abdominal↗