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PubMed2000

Physical activity and postmenopausal endometrial cancer risk (Sweden).

OBJECTIVES: To examine the hypothesis that sedentary women have an increased risk of endometrial cancer compared to physically active women. METHODS: This is a population-based case-control study in the entire Swedish female population aged 50-74 years in 1994-1995. We obtained self-reported information on leisure-time physical activity during childhood, at ages 18-30, and recently from 709 incident case women with endometrial cancer and 3368 population controls. Occupational physical activity was estimated through record linkage to the Swedish census data from 1960, 1970, 1980, and 1990. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for different activity levels by multivariate logistic regression, taking into account potential confounders. RESULTS: Comparing lowest to highest (reference) levels of physical exercise, we observed statistically significant associations with risk of endometrial cancer for leisure-time activity at age 18-30 years (multivariate OR = 1.4; 95% CI = 1.0-1.8; p for trend 0.01) and in recent years (multivariate OR = 1.3; 95% CI = 1.0-1.7; p for trend 0.01). We found similar associations comparing lowest to highest (reference) levels of occupational activity assessed at the censuses in 1980 (multivariate OR = 1.4; 95% CI = 1.0-1.9; p for trend 0.03) and 1990 (multivariate OR = 1.3; 95% CI = 0.9-1.9, p for trend 0.05), but a less consistent association with censuses in 1960 and 1970. The increased risk associated with low level of occupational physical activity was confined to women who were not obese and to women who were smokers. CONCLUSION: Our data, in conjunction with past epidemiological studies, indicate that both occupational and leisure-time physical activity may reduce the risk for postmenopausal endometrial cancer.

Aged↗
PubMed2004

[Development of a Hebrew questionnaire to be used in epidemiological studies to assess physical fitness--validation against sub maximal stress test and predicted VO2max].

BACKGROUND: The physical activity questionnaire is typically chosen for population studies because it is practical and does not interfere with the behavior of the surveyed individual. This instrument can be adapted for the particular studied population, and in terms of accuracy it is both reliable and valid. AIM: To develop a valid and appropriate measure to assess physical fitness according to the level of physical activity throughout the day, and to estimate the relation between a subjective questionnaire measurement evaluating physical activity, to predicted VO2max, as an objective measure of physical fitness. METHODS: Three hundred healthy subjects, 150 men and 150 women, aged 25-65 years old participated in this study. All subjects were routinely examined in the Sheba Medical Center Executive Screening Survey. They were asked to complete a self-administered questionnaire and report on the level of physical activity at work, the level of sports activity and the level of leisure time non-sport activity. The index calculated from the questionnaire was compared to the result from a sub-maximal exercise test, which they performed in The Executive Screening Survey, to composite a valid questionnaire to estimate physical fitness. RESULTS: A high and statistically significant correlation (r = 0.64, P < 0.01) was found between the indexes of physical activity calculated from the questionnaire to the predicted VO2max, measured from the sub-maximal exercise test. The reliability of the questionnaire was examined by test-retest and a high and statistically significant correlation (r = 0.89, P < 0.01) was found between the first and the proceeding one month administration of the questionnaire. The final modal to predict VO2max included a total index of physical activity, gender, BMI, age and resting heart rate. Overall this model predicted 58% of the VO2max. CONCLUSIONS: The self-administered questionnaire developed in this study has high construct validity and a significant correlation to predicted VO2max, with high sensitivity in both sexes and among active and non-active subjects. It is therefore an appropriate tool to be used in epidemiological studies.

Adult↗
PubMed2004

Joint effects of physical activity, body mass index, waist circumference and waist-to-hip ratio with the risk of cardiovascular disease among middle-aged Finnish men and women.

AIMS: To assess joint associations of physical activity and different indicators of obesity (body mass index, waist circumference, and waist-to-hip ratio) with the risk of cardiovascular disease (CVD). METHODS AND RESULTS: The study comprised 18,892 Finnish men and women aged 25-74 years without history of coronary heart disease, stroke, or heart failure at baseline. Physical activity, different indicators of obesity, education, smoking, blood pressure, total and high-density lipoprotein cholesterol and history of diabetes were measured at baseline. An incident CVD event was defined as the first stroke or coronary heart disease event or CVD death based on national hospital discharge and mortality register data. The median follow-up time was 9.8 years. Physical activity had a strong, independent, and inverse association with CVD risk in both genders. All obesity indicators had a significant direct association with CVD risk after adjustment for age, smoking, education and physical activity. Further adjustment for the obesity-related risk factors weakened the associations and they remained statistically significant in men only. Physical activity and the obesity indicators both predicted CVD risk in men, but in women the joint effect was inconsistent. CONCLUSION: Both regular physical activity and normal weight can reduce the risk of CVD. Physical inactivity seems to have an independent effect on CVD risk, whereas obesity increases the risk partly through the modification of other risk factors.

Adult↗
PubMed2002

Change in muscle strength explains accelerated decline of physical function in older women with high interleukin-6 serum levels.

OBJECTIVES: To test whether accelerated sarcopenia in older persons with high interleukin (IL)-6 serum levels plays a role in the prospective association between inflammation and disability found in many studies. DESIGN: Cohort study of older women with moderate to severe disability. PARTICIPANTS: Six hundred twenty older women from the Women's Health and Aging Study in whom information on baseline IL-6 serum level was available. MEASUREMENTS: Self-report of functional status, objective measures of walking performance, and knee extensor strength were assessed at baseline and over six semiannual follow-up visits. Potential confounders were baseline age, race, body mass index, smoking, depression, and medical conditions. RESULTS: At baseline, women with high IL-6 were more often disabled and had lower walking speed. After adjusting for confounders, women in the highest IL-6 tertile (IL-6>3.10 pg/mL) were at higher risk of developing incident mobility disability (risk ratio (RR) = 1.50, 95% confidence interval (CI) = 1.01-2.27), disability in activities of daily living (RR = 1.41, 95% CI = 1.01-1.98), and severe limitation in walking (RR = 1.61, 95% CI = 1.09-2.38) and experienced steeper declines in walking speed (P <.001) than women in the lowest IL-6 tertile (IL-6 < or =1.78 pg/mL). Decline in knee extensor strength was also steeper, but differences across IL-6 tertiles were not significant. After adjusting for change over time in knee extensor strength, the association between high IL-6 and accelerated decline of physical function was no longer statistically significant. CONCLUSIONS: Older women with high IL-6 serum levels have a higher risk of developing physical disability and experience a steeper decline in walking ability than those with lower levels, which are partially explained by a parallel decline in muscle strength.

Activities of Daily Living↗
PubMed2006

Effect of early correction of anemia on the progression of CKD.

BACKGROUND: This study is designed to assess the effect of early and complete correction of anemia by using recombinant human erythropoietin (epoetin) alfa on the progression of chronic kidney disease (CKD). METHODS: Patients were randomly assigned to achieve high (13 to 15 g/dL [130 to 150 g/L]) or low (11 to 12 g/dL [110 to 120 g/L]) hemoglobin-level targets during 4 months of stabilization, followed by 36 months of maintenance. Glomerular filtration rate (GFR) decrease was measured by using iohexol clearance. Quality of life, nutrition, and safety also were monitored. RESULTS: Because of labeling changes for subcutaneous administration of epoetin alfa (Eprex; Johnson and Johnson, Schaffhausen, Switzerland), the study was terminated prematurely. There were 195 patients enrolled in each group; 108 high-hemoglobin and 133 low-hemoglobin patients entered the maintenance phase. Mean maintenance duration was 7.4 months for the high-hemoglobin group and 8.3 months for the low-hemoglobin group. GFR decrease was numerically, but not statistically significantly, lower with the high-hemoglobin group (0.058 versus 0.081 mL/min/1.73 m2/mo [< 0.01 mL/s/1.73 m2/mo]). Physical quality-of-life measures showed trends (Role-Physical, P = 0.055; Physical Function, P = 0.083) or statistically significant improvement (Vitality, P = 0.042) with high hemoglobin levels at the end of the stabilization phase. Adverse events were similar between groups. Cardiovascular adverse events occurred in 25% of the high-hemoglobin and 18% of the low-hemoglobin patients (P = 0.137). Neither epoetin dosage nor hemoglobin level was associated with cardiovascular adverse events or death. CONCLUSION: These data suggest that normalization of hemoglobin levels in patients with CKD is safe. Longer duration studies are needed to clarify efficacy benefits with high hemoglobin levels.

Adolescent↗
PubMed1998

A workplace stretching program. Physiologic and perception measurements before and after participation.

The purpose of this study was to implement a primary prevention program in the workplace targeted to prevent muscle strains. Physiologic and perception measurements were taken before and after participation in a stretching program developed to improve flexibility through conditioning. A one group pre-test post-test design was used with 60 employees enrolled in a 36 session stretching program in the workplace. Flexibility was measured by a flexibility profile including the sit and reach test, bilateral body rotation measurements, and shoulder rotation measurements. A statistically significant increase was found in all flexibility measurements at the conclusion of the study for the participants as a total group. Perception, as measured by the Fox Physical Self Perception Profile, was statistically significant in relation to participants' perceptions of their body attractiveness, physical conditioning, and overall self worth at the program's conclusion. In addition, participants who completed the program had zero occurrences of musculoskeletal injuries during the 2 month period. The results of this study suggest that continued development and implementation of stretching programs in the workplace may benefit employees by increasing flexibility and potentially preventing injuries due to muscle strains. Stretching programs in the workplace also may improve components of employees' perceptions of their physical bodies.

Adult↗
PubMed1989

Proton production in relativistic heavy ion collisions; comparison with a thermodynamical model.

Experimental results concerning proton production in nuclear collisions, obtained at Saturne with the Diogene 4 pi facility, are compared with the predictions of a thermodynamical model, using collective velocity distributions combined with a statistical thermodynamics in local rest frames. Experimental differential cross sections for alpha + nucleus and Neon + nucleus central collisions at incident energies between 200 and 800 MeV per nucleon are well reproduced by the model, for an angular range 30-110 degrees in the laboratory system. Extracted values of the temperatures are compared with those given by other authors.

Models, Theoretical↗
PubMed2002

Effect of aging on male and female master athletes' performance in strength versus endurance activities.

Aging has traditionally been associated with several functional declines within the musculoskeletal system. In this study, we characterized and compared age-related changes in performance in power and endurance activities (ie, power-lifting, stationary rowing). From age 25 to age 85, men's and women's rowing performance decreases 29%; from age 25 to age 55, men's rowing performance decreases 0.12% per year, and women's performance decreases 0.23% per year. The pattern of decline in power-lifting performance is characterized by earlier onset and more rapid progression. During the fourth decade, men's and women's power-lifting performance decreases 3% per year; thereafter, their performance decreases 1% per year. The difference between the age-related change rates for rowing and power-lifting is statistically significant (P = .05). The older athletes' performance in both activities suggests that the capacity for significant function in activities requiring power and endurance persists throughout life in individuals who train and who remain in good health. That strength decreases more rapidly than endurance capacity points to the importance of resistance exercises for minimizing muscle weakness in an aging population.

Adult↗
PubMedDate not supplied

[The ontogenetic characteristics of the functional organization of the cerebral hemispheres in selective attention: perceptual task expectancy].

EEG characteristics of brain organization of selective attention were studied in children (n = 10, 9 years old) during task expectancy with special reference to hemisphere specialization. Children had to distinguish lateralized signals according to their duration. Warning stimulus pointed to the modality of the task (tactile, auditory, visual). Intra-hemispheric alpha-coherence was evaluated in the prestimulus period with the following statistical analysis of the individual data. The main distinctions of the brain functional organization during expectancy between children and adults consisted in less pronounced selectivity of EEG changes in the left hemisphere and in existence of modal specificity in the right hemisphere in children as compared to adults. Thus, the functional specialization of the hemispheres in children is not yet completely developed. Brain hemispheres of children partly share functions rather than complement each other.

Adult↗
PubMed1994

[Do the physical characteristics of radiopaque markers modify the results of the measurement of colonic transit time?].

UNLABELLED: This study was performed in 15 healthy control subjects (8 males- age 23-70 and 7 females age 20-74) as a way to compare the total and segmental colonic transit time with two different type of radiopaque markers. One type of markers was 3 mm cut sections of a radiopaque polietilene 14 French Levine tube, with a medium weight of 64.3 mg and a specific gravity (SG) of 1.28. The other type were 7 mm lenticular insoluble barium (lentils) with medium weight of 231 mg and a SG of 1.87. Each subject ingested 20 markers of each type with the breakfast and front and profile plain films of the abdomen were taken 24 and 48 hs after. The total colonic transit time for the polietilene markers was 17.7 hs and 27.3 hs for the barium type (BM) (p < 0.001). The segmental transit time for right colon was 2.4 hs (PM) and 9.7 hs (PM) and 9.7 hs (BM) (p < 0.001) in the left colon 9.5 hs (PM) and 11.3 hs (BM) and in rectoanun 5.9 hs (BM) with no statistical significance. CONCLUSION: the physical characteristics of the radiopaque markers can modify the results of the colonic transit times.

Adult↗
PubMed1996

Recent developments in the theory of protein folding: searching for the global energy minimum.

Statistical mechanical theories and computer simulation are being used to gain an understanding of the fundamental features of protein folding. A major obstacle in the computation of protein structures is the multiple-minima problem arising from the existence of many local minima in the multidimensional energy landscape of the protein. This problem has been surmounted for small open-chain and cyclic peptides, and for regular-repeating sequences of models of fibrous proteins. Progress is being made in resolving this problem for globular proteins.

Chemical Phenomena↗
PubMed2000

Functioning in daily living and psychological well-being of female cancer patients.

The objective of this prospective study was to compare outcomes concerning psychological and physical functioning of patients with various gynecological malignancies. A sample of 119 newly diagnosed cancer patients completed two questionnaires evaluating psychological well-being and functioning in daily living. Outcome measures were obtained at three time points: before surgery, 3 months after surgery, and 1 year after surgery. The results showed that the psychological well-being improved significantly from the first to the third time point for the sample as a whole. After surgery, patients with ovarian and cervical cancer showed slightly lower scores than patients with endometrial cancer. The level of functioning in daily living declined 3 months after surgery for all except endometrial cancer patients, but increased significantly at the 1 year follow-up. At all three time points the mean differences for psychological well-being and functioning in daily living were not statistically significant among subgroups. Physical and psychological well-being of the patients treated for gynecological malignancies is affected independently of age, cancer site and stage of disease. However, throughout the observational period the psychological well-being scores were lower than those of patients with other chronic illnesses or healthy subjects. Therefore, we conclude that psychological interventions for patients facing gynecological cancer treatment should be provided as an integral component of cancer management.

Activities of Daily Living↗
PubMed1994

Safety and compatibility of betaxolol hydrochloride combined with diltiazem or nifedipine therapy in stable angina pectoris.

Compared with placebo, adding betaxolol 20 mg every day to nifedipine (up to 60 mg/day in divided doses) or diltiazem (up to 360 mg/day in divided doses) for a 3-week treatment period in 135 patients with stable angina pectoris significantly (p < 0.05) lengthened the time to onset of moderate angina during exercise tolerance tests at all treatment time points. The median increases in the time to onset of moderate angina at the final exercise tolerance test (end point) compared with baseline were 1.08 and 0.53 minutes for betaxolol and placebo groups, respectively (p = 0.002, betaxolol and placebo groups, respectively (p = 0.002, betaxolol vs placebo). The time to onset of 1 mm ST-segment depression increased significantly (p < 0.05) with betaxolol compared with placebo at all but 1 treatment time point (median increase [p = 0.001] 1.77 and 0.37 minutes, respectively, at end point). Duration of exercise also was increased significantly (p < 0.05) after the third week of treatment and at end point (median 0.62 and 0.50 minutes, respectively; p = 0.03). Generally comparable results were found within the diltiazem (n = 128) and nifedipine (n = 25) subgroups, although the nifedipine group was too small to detect statistically significant differences between betaxolol and placebo treatment. Resting systolic blood pressure, heart rate and the rate-pressure product, measured both when angina occurred and at the end of exercise, also were influenced significantly (p < 0.05) by the betaxolol addition. The only serious adverse effect associated with betaxolol treatment was syncope, seen in 2 patients.

Adult↗
PubMed2003

Bile salt/lecithin mixed micelles optimized for the solubilization of a poorly soluble steroid molecule using statistical experimental design.

Bile salts and lecithin combine physiologically to form mixed micelles which aid the solubilization and absorption of dietary fats and drug molecules. In this series of experiments, we have shown how experimental design procedures aid the optimization of a formulation incorporating a bile salt, lecithin, and water with fluticasone propionate (FP) as the model poorly soluble drug. The initial inclusion of a categorical variable ruled out the use of classic response surface designs; therefore the experimental design was constructed using a d-optimal selection from a candidate set of all possible experimental combinations. A separate 2-factor central composite design was used to determine the optimum lecithin and bile salt concentrations over an extended range after the categorical variable had been eliminated. It has been demonstrated that an increase in either lecithin or cholic acid concentration produces an increase in solubility of FP, while sodium taurocholate appears to depress the solubility of FP compared with the other two bile salts. The increase in solubility associated with the increase in bile salt and lecithin is further demonstrated by a linear relationship between FP solubility and the total lipid in the formulation. The influence of molar ratio of lecithin to bile salt in the formulation is also significant. The physical properties of the mixed micellar system (solution turbidity and viscosity ranking) were used to further discriminate between formulations. The optimization showed that the dominant effect was the lecithin, which improves the solubilizing characteristics of the formulation with increasing concentration. The effect of salt concentration is less marked though slightly quadratic in nature. The overall increase in solubility demonstrated was from <1 microg/mL in water to 205 microg/mL in the optimized mixed micellar system.

Bile Acids and Salts↗
PubMed2005

Statistical mechanics of columnar DNA assemblies.

Many physical systems can be mapped onto solved or "solvable" models of magnetism. In this work, we have mapped the statistical mechanics of columnar phases of ideally helical rigid DNA--subject to the earlier found unusual, frustrated pair potential (A.A. Kornyshev, S. Leikin, J. Chem. Phys. 107, 3656 (1997))--onto an exotic, unknown variant of the XY model on a fixed or restructurable lattice. Here, the role of the "spin" is played by the azimuthal orientation of the molecules. We have solved this model using a Hartree-Fock approximation, ground-state calculations, and finite-temperature Monte Carlo simulations. We have found peculiar spin order transitions, which may also be accompanied by positional restructuring, from hexagonal to rhombohedric lattices. Some of these have been experimentally observed in dense columnar aggregates. Note that DNA columnar phases are of great interest in biophysical research, not only because they are a useful in vitro tool for the study of DNA condensation, but also since these structures have been detected in living matter. Within the approximations made, our study provides insight into the statistical mechanics of these systems.

Computer Simulation↗
PubMed1992

Influence of aerobic capacity, body composition, and thyroid hormones on the age-related decline in resting metabolic rate.

It has been suggested that changes in fat-free weight may not fully explain the decline of resting metabolic rate (RMR) that occurs with aging. We therefore examined the hypothesis that a reduction in maximal aerobic capacity (VO2max) may partially explain the lower RMR in older men, after accounting for differences in fat-free weight and fat weight. We also considered differences in energy intake and plasma thyroid hormones as possible modulators of the age-related decline in RMR in men. Three-hundred healthy men (aged 17 to 78 years) were characterized for: (1) RMR (kcal/min) from indirect calorimetry; (2) body composition from underwater weighing; (3) maximal aerobic capacity from a test of VO2max; (4) plasma thyroid hormones (total triiodothyronine [T3], free T3, total thyroxine [T4], and free T4); and (5) estimated energy intake (kcal/d) from a 3-day food diary. A curvilinear decline of RMR with age was found (P less than .01), in which no relationship was found in men less than 40 years of age (r = .10, slope = 0.002 kcal/min/yr), whereas in men older than 40 years, RMR was negatively related to age (r = -.52, slope = -0.008 kcal/min/yr). After statistical control for differences in fat-free weight and fat weight, a negative relationship between age and RMR persisted (partial r = -.30, P less than .01). It was only after control for fat-free weight, fat weight, and VO2max (partial r = -.10, P greater than .05) that no association between age and RMR was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗