Biomedical subjects

N Tomoyasu

Publications and source records attributed to N Tomoyasu.

11 recordsLinked to original sources

PubMed2001

HIV and AIDS surveillance among inmates in Maryland prisons.

The prevalence of those with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) is higher among inmates of correctional facilities than among the general population. This raises the need to identify inmates living with or at risk of HIV/AIDS and to provide counseling and appropriate services for HIV treatment and prevention. The Maryland Division of Corrections (DOC) offers voluntary testing to all inmates on entry and tests inmates when clinically indicated. We reviewed all 1998 HIV antibody tests and confirmed AIDS cases in the Maryland DOC. Inmate demographics, testing acceptance, rates of seropositivity, and AIDS cases and comparisons based on gender, race/ethnicity, and age were examined. Comparisons were also made to HIV testing and AIDS cases from the nonincarcerated Maryland population. Trends in DOC AIDS diagnoses and AIDS-related deaths over time were also examined. Of the inmates, 39% were voluntarily tested for HIV on entry to the Maryland DOC in 1998 (38% of males and 49% of females). Overall, HIV seropositivity was 3.3% (5% for females and 3% for males). The 888 cumulative AIDS cases diagnosed in the DOC inmate population were concentrated among males (90% vs. 77% statewide), African Americans (91% vs. 75% statewide), and among IDUs (84% vs. 39% statewide). Due to high rates of HIV and AIDS, inmate populations are a crucial audience for HIV/AIDS testing, treatment, and prevention efforts, especially women. Prison-based programs can identify significant numbers of HIV and AIDS cases and bring HIV prevention interventions to a population characterized by frequent high-risk behavior.

AIDS Serodiagnosis↗

PubMed2001

Self-efficacy targeted treatments for weight loss in postmenopausal women.

Matching behavioral treatment programs to different types of obese clients is a rarely studied strategy, thus guidelines for identifying who might benefit most from which program remain elusive. This study categorized the weight control self-efficacy beliefs of obese, postmenopausal women, and determined the effects of self-efficacy targeted versus non-targeted (control) treatment on weight loss outcomes (body habitus, physical conditioning, affect, and eating behaviors). Obese (BMI 33 +/- 5), postmenopausal (60 +/- 6 years old) women (n = 59) participated in a 6-month weight loss program. The 37 women categorized by Q methodology as Assured (self-confident, independent) were randomized to Assured (AT) or Non-Targeted (NT) treatment; the 22 Disbelievers (doubtful, wavering) were randomized to Disbeliever (DT) or NT treatment. At baseline, the Assureds had significantly smaller body girths and reported significantly greater self-esteem, fewer symptoms of binge eating, and less negative affect overeating than the Disbelievers. Improvement in these variables with weight loss erased significant differences between the groups and was a desired outcome. Treatment delivery type may have influenced attrition rate, since significantly more Assureds dropped from NT than AT and significantly more Disbelievers dropped from DT than NT. Thus, the self-efficacy type may serve as a means to identify different types of treatment needs (flexible vs. rigid) to sustain women's adherence and success in the program. The significant weight loss outcomes for women in all groups argues for the incorporation of strategies to enhance self-efficacy but not the need for specific treatments that directly target self-efficacy types.

Aged↗

PubMed2000

A profile of early versus late onset of obesity in postmenopausal women.

Obesity is a serious health problem among women across the life span. Although people can become obese at any age, there is a large proportion of older women who have been obese since childhood. The purpose of this study was to determine whether postmenopausal women with an early versus late onset of obesity manifested differences in body habitus, eating behaviors, and mood. One hundred thirty-five postmenopausal women with obesity responded to self-report questionnaires on weight history, weight loss and maintenance expectancy, eating behaviors, and mood. Women with an early onset of obesity had a significantly higher body mass index (BMI), waist circumference, and highest attained adult body weight than women with a late onset of obesity. They had attempted a significantly larger number of diets and had lost more weight on any single diet. The groups also differed significantly on binge eating and overeating in response to negative affect. There was a tendency for women with an early onset to have more depressive and anxious symptoms. Postmenopausal women with an early onset of obesity differed physiologically and psychologically from those with a late onset. Tailoring dietary and behavioral interventions to profiles of postmenopausal women based on onset of obesity may improve the overall efficacy of weight loss programs.

Affect↗

PubMed1999

Effects of cigarette smoking and its cessation on body weight and plasma leptin levels.

Smokers weigh less than age-matched nonsmokers, and most smokers gain weight after smoking cessation due to an increase in food intake and a decrease in energy expenditure. Leptin is an endocrine signal thought to regulate body fat stores through hypothalamic control of energy intake and expenditure. To determine whether the "weight-reducing" effects of smoking may be mediated by leptin, we measured plasma leptin concentrations in 22 middle-aged and older male smokers (body mass index [BMI], 28 +/- 1 kg/m2, mean +/- SEM) and 22 nonsmokers matched to the smokers for age (64 +/- 1 years) and BMI (28 +/- 1 kg/m2). The body weight and leptin concentration were remeasured at 3 and 6 months in 13 of the smokers who successfully stopped smoking. The leptin concentration correlated positively with the BMI in both smokers (r = .74, P < .001) and nonsmokers (r = .76, P < .001). However, the intercept of the regression line was higher for smokers versus nonsmokers (P < .05), with no difference in the slope. Thus, male smokers have a higher leptin level for a given BMI than nonsmokers. Following 6 months of smoking cessation, body weight increased by 7% (6.0 +/- 0.1 kg, n = 13, P < .01). Despite this weight gain, the mean leptin concentration did not increase with smoking cessation. On average, leptin levels were 25% lower than would be expected for the amount of weight gained after smoking cessation. These findings suggest that cigarette smoking directly elevates circulating plasma leptin concentrations, and this increase may be one mechanism for the lower body weight of smokers compared with nonsmokers.

Aged↗

PubMed1998

Patients' pretreatment expectations of chemotherapy-related nausea are an independent predictor of anticipatory nausea.

Based on extensive research with animals, classical conditioning theorists have come to regard contingency as the primary factor in the development of conditioned responses. However, recent experimental work with humans has suggested the possibility that participant expectations may also directly contribute to the development of conditioned responses. To date, this phenomenon has not been investigated in clinical settings. Anticipatory nausea (AN) in chemotherapy patients, widely viewed as the best established example of classical conditioning in clinical medicine, provides an opportunity to examine the contributions of patient expectations to the development of a conditioned response outside the laboratory. The present study of 59 breast cancer patients supported the hypothesis that pretreatment patient expectations make a significant (p < .03) contribution to the development of AN after statistically controlling for the strongest conditioning predictor, contingency. These data imply that patient expectations should be considered when evaluating conditioned responses to aversive medical treatments.

Adult↗

PubMed1997

Treadmill aerobic exercise training reduces the energy expenditure and cardiovascular demands of hemiparetic gait in chronic stroke patients. A preliminary report.

BACKGROUND AND PURPOSE: Elevated energy costs of hemiparetic gait contribute to functional disability after stroke, particularly in physically deconditioned older patients. We investigated the effects of 6 months of treadmill aerobic exercise training on the energy expenditure and cardiovascular demands of submaximal effort ambulation in stroke patients with chronic hemiparetic gait. METHODS: Nine older stroke patients with chronic hemiparetic gait were enrolled in a 6-month program of low-intensity aerobic exercise using a graded treadmill. Repeated measures of energy expenditure based on steady state oxygen consumption during a standardized 1-mph submaximal effort treadmill walking task were performed before and after training. RESULTS: Six months of exercise training produced significant reductions in energy expenditure (n = 9; 3.40 +/- 0.27 versus 2.72 +/- 0.25 kcal/min [mean +/- SEM]; P < .005) during a given submaximal effort treadmill walking task. Repeated measures analysis in the subset of patients (n = 8) tested at baseline and after 3 and 6 months revealed that reductions in energy expenditure were progressive (F = 11.1; P < .02) and that exercise-mediated declines in both oxygen consumption (F = 9.7; P < .02) and respiratory exchange ratio (F = 13.4; P < .01) occurred in a strong linear pattern. These stroke patients could perform the same standardized submaximal exercise task at progressively lower heart rates after 3 months (96 +/- 4 versus 87 +/- 4 beats per minute) and 6 months of training (82 +/- 4 beats per minute; F = 35.4; P < .002). CONCLUSIONS: Six months of low-intensity treadmill endurance training produces substantial and progressive reductions in the energy expenditure and cardiovascular demands of walking in older patients with chronic hemiparetic stroke. This suggests that task-oriented aerobic exercise may improve functional mobility and the cardiovascular fitness profile in this population.

Aged↗

PubMed1996

Conditioned reactions to cancer chemotherapy: percent reinforcement predicts anticipatory nausea.

Current theorizing on classical conditioning has emphasized the role of contingent relations between the conditioned and unconditioned stimuli in the development of conditioned responses. The present study is the first to examine the relevance of this concept to our understanding of the phenomenon of anticipatory nausea in cancer chemotherapy patients. Anticipatory nausea in patients receiving emetogenic chemotherapy has been cited as an example of the importance of classical conditioning in clinical medicine. Outpatient chemotherapy can be viewed as a series of conditioning trials in which the previously neutral stimuli of the clinic (conditioned stimuli) are associated with chemotherapy infusions and postinfusion nausea. Reexposure to these clinic stimuli alone is sufficient to elicit nausea (conditioned response) in some patients prior to subsequent infusions. In the present study we examined whether differences among patients in percent reinforcement (the percentage of infusions followed by nausea) would predict anticipatory nausea, which was assessed at the sixth infusion. Results were consistent with the hypothesis. Percent reinforcement was positively correlated with the incidence of anticipatory nausea. Comparison of patients with and without anticipatory nausea (t-test and hierarchical logistic regression analysis) confirmed that percent reinforcement was a significant predictor of anticipatory nausea, independent of other factors previously reported to be involved.

Adult↗

PubMed1994

Food aversion induced by area postrema ablation.

Rats with lesions of the area postrema (APX rats) avoid foods ingested on a regular basis during the period of severe hypophagia immediately following surgery (Tomoyasu & Kenney, 1989). The present work determined whether APX rats would also avoid foods to which they are exposed only after they have recovered from the lesion-induced hypophagia. APX and SHAM-lesion rats were fed a novel food for 8 days beginning at least 1 month after surgery when food intakes (adjusted for body weight) and weight gains of the APX rats had returned to control levels. During 24 h, two-food choice tests, APX rats avoided the food ingested a month after the ablation while avidly ingesting an alternative food, but SHAM rats showed no preference between the foods. There was no indication that this aversion developed by APX rats to foods ingested after recovery from hypophagia is weaker than that developed to foods ingested immediately after the lesion. We conclude that area postrema ablation results in the development of an unconditioned stimulus capable of supporting food-aversion conditioning which remains effective more than 1 month after the ablation. Hence, the relationship between APX-induced food aversion and hypophagia must be indirect and complex. Also, conditioning of food aversions induced by area postrema ablation alone may confound studies of the role of this structure in mediating the development of food aversions after other physiological and/or pharmacological manipulations.

Animals↗

PubMed1991

The triple threat: a discussion of gender, class, and race differences in weight.

Gender, poverty and race, the "triple threat" referred to in the title, are three major risk factors that contribute to the high prevalence of weight-related problems in this country. Current psychological literature on weight management has generally ignored the effects of these variables and their implications for developing interventions for underserved populations which include women, minorities and poor people. The present paper discusses the literature on the effects of gender, race, and class on weight levels and associated psychosocial variables. Conclusions drawn illustrate that weight is a major issue for women, and that race and class also have effects on weight levels which can affect health status. Areas of further exploration and of action are identified to address problems that women face regarding weight.

Attitude to Health↗

PubMed1989

Body weight of rats following area postrema ablation: effect of early force-feeding.

This study examined the effect of intragastric force-feeding of a milk diet on body weights of rats with lesions of the area postrema/caudal medial nucleus of the solitary tract (AP/cmNTS). Force-feeding was conducted over the first 10 days after the ablation. Body weight was monitored both during and after force-feeding. Food intake was measured during all ad libitum feeding periods. During force-feeding, rats with AP/cmNTS lesions gained weight at the same rate as force-fed sham-lesioned rats or sham-lesioned rats that voluntarily ingested an equal amount of the milk. When returned to ad libitum feeding, lesioned rats that had been force-fed were not hypophagic and did not lose weight. Body weights of such rats remained above those of lesioned rats that were not force-fed and similar to those of nonlesioned rats throughout this study. Despite their normal weights, preliminary analysis indicated that body fat of the force-fed lesioned rats may have been reduced. These findings suggest that the effects of AP/cmNTS ablation are multiple and that reduction of body weight need not be the primary effect of such lesions.

Animals↗

PubMed1989

Response to palatability after area postrema lesions: a result of learned aversions.

The role of palatability, novelty, and food aversion in determining changes of food choice after ablation of the area postrema and caudal-medial aspect of the nucleus of the solitary tract (AP/cmNTS) is examined through a series of studies utilizing 24-h, two-food choice tests. On test days, the food that the animal has ingested since the time of lesioning or sham surgery is presented along with a novel food that varies in palatability. The results indicate that postlesion diet history is the major determinant of food choice by lesioned rats. Lesioned rats consistently take less of their familiar postlesion food than diet-matched controls, suggesting that the lesioned rats have developed an aversion to that food. Over-ingestion of the novel food may occur, but this outcome is not reliable. No indication that the animals' response to food palatability is affected by AP/cmNTS ablation was found. Learned aversion to a food ingested after AP/cmNTS ablation may account not only for changes of food preference after the lesion but also may be involved in the hypophagia and weight loss resulting from the ablation.

Animals↗