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Biomedical subjects

R E Rhodes

Publications and source records attributed to R E Rhodes.

At least 19 recordsLinked to original sources

Personality correlates of physical activity: a review and meta-analysis.

This review aimed to combine the literature on major personality traits and physical activity alongside providing some meta-analytic summaries of the findings. Overall, 33 studies containing 35 independent samples, ranging from 1969 to 2006, met the inclusion criteria. Extraversion (r = 0.23), neuroticism (r = -0.11) and conscientiousness (r = 0.20) were identified as correlates of physical activity using random effects meta-analytic procedures correcting for sampling bias and attenuation of measurement error. The five-factor model traits of openness to experience/intellect and agreeableness, as well as Eysenck's psychoticism trait, were not associated with physical activity. Potential moderators of personality and physical activity relationships such as sex, age, culture/country, design and instrumentation were inconclusive given the small number of studies. Still, the existing evidence was suggestive that personality and physical activity relationships are relatively invariant to these factors. Studies examining personality and different physical activity modes suggested differences by traits such as extraversion, but more research is needed to make any conclusions. Future research using multivariate analyses, personality-channelled physical activity interventions, longitudinal designs and objective physical activity measurement is recommended.

Age Factors↗

Social ecological correlates of physical activity in normal weight, overweight, and obese individuals.

OBJECTIVE: Research is limited concerning the moderating influence of weight status (ie normal, over, and obese) on the social ecological correlates of physical activity (PA) in adults. Therefore, the present study attempted to shed light on this issue. DESIGN: In 2001, a national cross-sectional mail out panel survey was conducted over a 3-month period in the United States. SUBJECTS: There were 1867 normal weight (ie body mass index (BMI)=20-24.99 kg/m2), 2145 overweight (ie BMI=25-29.99 kg/m2), and 1902 obese (ie BMI>30 kg/m2) adults. MEASURES: Various demographic measurements were taken in addition to social support (SS), self-efficacy (SE), access to facilities, and PA. RESULTS: Normal weight individuals engaged in significantly more PA than overweight individuals, who in turn engaged in significantly more PA than obese individuals F(2,5991)=55.51, P<0.01. Further regression analyses showed that higher SE, SS, the access to facilities in a neighborhood, and various interactions among these constructs were significantly and positively associated with PA. Interestingly, the strength of these relationships varied depending on weight status. CONCLUSION: Weight status needs to be taken into consideration when examining social ecological correlates of PA.

Adult↗

Temporal relationships of self-efficacy and social support as predictors of adherence in a 6-month strength-training program for older women.

The present study investigated how self-efficacy and social support predicted adherence to a strength training program for elderly women over two time periods in the initial 6 mo. of the program. Participants were 30 elderly women volunteers aged 75 to 80 who completed measures of barrier self-efficacy and general social support at baseline and 3 mo. later. Social support from the program was also measured at 3 mo. Adherence to the program was measured by attendance. Hierarchical regression equations were utilized to identify the contributions of self-efficacy and social support for adherence at 0 to 3 mo. and 4 to 6 mo. For prediction of the first 3 mo. of adherence, both self-efficacy and social support contributed significant unique variance towards the total explained variance of 36%. For the 4- to 6-mo. period, self-efficacy explained significant (12%) variance in adherence even when controlling for the previous 3-mo. adherence. Inclusion of general social support and social support from the program, however, did not account for significant variance. Researchers must continue to examine self-efficacy and social support in exercise adherence within various time periods among older adults to develop effective intervention strategies.

Aged↗

Factors associated with exercise adherence among older adults. An individual perspective.

This paper reviews the literature concerning factors at the individual level associated with regular exercise among older adults. Twenty-seven cross-sectional and 14 prospective/longitudinal studies met the inclusion criteria of a mean participant age of 65 years or older. The findings are summarised by demographics, exercise experience, exercise knowledge, physiological factors, psychological factors, activity preferences and perceived social influences. In general, education and exercise history correlate positively with regular exercise, while perceived physical frailty and poor health may provide the greatest barrier to exercise adoption and adherence in the elderly. Social-cognitive theories identify several constructs that correlate with the regular exercise behaviour of older adults, such as exercise attitude, perceived behavioural control/self-efficacy, perceived social support and perceived benefits/barriers to continued activity. As well, stage modelling may provide additional information about the readiness for regular exercise behaviour among older adults. However, relatively few studies among older adults exist compared with middle-aged and younger adults. Further, the majority of current research consists of cross-sectional designs or short prospective exercise trials among motivated volunteers that may lack external validity. Future research utilising longitudinal and prospective designs with representative samples of older adults will provide a better understanding of significant causal associations between individual factors and regular exercise behaviour.

Aged↗

Talc granulomatosis presenting as spontaneous pneumothorax.

Spontaneous pneumothorax has been described in association with conglomerate masses and bullous disease in end-stage talc granulomatosis. Our case demonstrates that pneumothorax can occur earlier in the course of the disease before these end-stage radiographic changes are present.

Adult↗

Opioid receptors and endogenous opioids in diverse human and animal cancers.

Receptor binding studies demonstrated specific high-affinity, saturable binding of a number of opioid ligands to a wide variety of neural and nonneural human and animal tumors. Radioimmunoassays revealed the presence of beta-endorphin and methionine-enkephalin in these tumors. Both methionine- and leucine-enkephalin were detected in tumor tissue by immunocytochemistry, with immunoreactivity related to the cortical cytoplasm of tumor cells, but not to cell nuclei. Endogenous opioids and receptors were found in benign and malignant tumors representative of ectodermal, mesodermal, and endodermal origin. Receptors and endogenous opioid peptides were present in tumors from many different species, including those transplanted into nude mice. These results suggest that opioid receptors and endogenous opioids are fundamental features of human and animal cancers.

Animals↗

Localization of enkephalin immunoreactivity in diverse tissues and cells of the developing and adult rat.

The distribution of enkephalin, an endogenous opioid, in tissues and cells of the developing and adult rat was determined by immunocytochemistry with antibodies to met- and leu-enkephalin. Met- and leu-enkephalin were found in all developing cells investigated, with staining generally located throughout the cytoplasm; cell nuclei were not immunoreactive. In comparison to developing cells, immunoreactive analogues to met-enkephalin were usually difficult to detect in the adult. Some notable exceptions were reaction products in leukocytes in blood, lung, and cortex of thymus, fibroblasts in the skin, and seminiferous tubules. These results, in concert with earlier reports that opioid receptors are found largely in developing, but not adult, tissues, indicate that endogenous opioids are specifically involved in biological development, particularly cell proliferation and differentiation. Immunoreactivity in adult non-neural cells may be related to their development in some cases, but also could indicate other functions.

Animals↗

Distribution of enkephalin immunoreactivity in germinative cells of developing rat cerebellum.

The cellular distribution of enkephalin, an endogenous opioid, in the developing rat cerebellum was determined by immunocytochemistry. Methionine and leucine enkephalin were concentrated in the external germinal layer, a matrix of proliferative cells; staining was confined to the cortical cytoplasm. Enkephalin was not detected by immunocytochemistry in differentiated neural cells. These results indicate that endogenous opioids are involved specifically in early phases of nervous system development, particularly cell proliferation and differentiation.

Animals↗

Mass spectral identification of the metabolites of alpha,alpha-dimethyl-4-(alpha,alpha,beta,beta-tetrafluorophenethyl)-benzylamine (MK-251), a novel antiarrhythmic agent, in various species.

The identification of a number of metabolites of the novel antiarrhythmic agent, alpha,alpha-dimethyl-4-(alpha,alpha,beta,beta-tetrafluorophenethyl)benzylamine (MK-251), is presented. The compound is extensively metabolized by dog, monkey, baboon and man. Similar metabolic profiles were obtained for all species. Isolation and purification were accomplished by solvent extraction and chromatographic (column, gas and thin-layer) procedures. Gas chromatography, derivatization, infrared, nuclear magnetic resonance and particularly combined gas chromatography low and high resolution mass spectrometry techniques were employed to characterize the metabolites. The major urinary and plasma metabolites were identified as 2-[4-(alpha,alpha,beta,beta-tetrafluorophenethyl)phenyl]-2-propanol and its glucuronide conjugate. Other metabolites characterized were: the N-glucuronide of MK-251; 2-[4-(alpha,alpha,beta,beta-tetrafluorophenethyl)phenyl]propene; 2-nitro-2-[4-)alpha,alpha,beta,beta-tetrafluorophenethyl)phenyl]propane; alpha,alpha-dimethyl-4(alpha,alpha,beta,beta-tetrafluorophenethyl)benzyl methyl ether; and 4-(alpha,alpha,beta,beta-tetrafluorophenethyl)acetophenone. The 0-methyl ether metabolite represents the first instance of in vivo alkylation of a tertiary alcohol. Tentative identification was made for the N-hydroxy analog of MK-251 and for the glycol analog of 2-[4-(alpha,alpha,beta,beta-tetrafluorophenethyl)phenyl]-2-propanol. The observed pharmacological response appears to result mainly from MK-251 and not from the four metabolites.

Amines↗

Personality and exercise participation across the breast cancer experience.

The purpose of this study was to investigate the relationship between personality and exercise participation across the breast cancer experience. Based on the Five-Factor Model and previous exercise research, it was hypothesized that high scores of extraversion (E) and conscientiousness (C), and low scores of neuroticism (N) would discriminate exercise stage during and following cancer treatment as well as changes in exercise stage across the cancer experience (i.e. from prediagnosis through treatment to posttreatment). Participants were 175 non-metastatic breast cancer survivors who completed a mailed questionnaire that assessed demographic and medical information, personality (the NEO-Five Factor Inventory), and exercise stage recalled for three time periods (prediagnosis, during treatment, and posttreatment). Multivariate analysis of variance showed differences in personality based on exercise stage both during cancer treatment and posttreatment and also for exercise pattern across the cancer experience. Univariate F-tests and post hoc analyses identified N, E, and C as the key personality dimensions. N was associated with earlier exercise stages and a maladaptive exercise pattern whereas E and C were associated with more advanced exercise stages and adaptive exercise patterns. It was concluded that personality may be an important determinant of exercise following breast cancer diagnosis.

Adaptation, Psychological↗

Hemorrhagic adrenal adenoma simulating myelolipoma: CT evaluation.

We present a hemorrhagic adrenal adenoma surrounding and encompassing adjacent retroperitoneal fat to simulate the appearance of a myelolipoma by CT. A well-defined fibrous capsule, punctate calcification, and several macroscopic foci of fat within the mass led to an erroneous preoperative diagnosis. Lesions displaying large amounts of soft tissue attenuation material in addition to fat preclude a confident diagnosis of myelolipoma and should undergo directed percutaneous needle biopsy or surgery.

Adenoma↗

Walker-Warburg syndrome.

The Walker-Warburg syndrome (WWS) is a rare autosomal recessive disorder characterized by lissencephaly, cerebellar and retinal malformations, and congenital muscular dystrophy. We report a new case of WWS identified with the aid of cranial MR and briefly review the radiologic findings of this lethal syndrome.

Cerebellum↗