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PubMed1989

Endothelial cell-stimulating angiogenesis factor in vitreous from extraretinal neovascularizations.

The presence of endothelial cell-stimulating angiogenic factor (ESAF) in diseased human vitreous humour has been established. The molecular mass and chromatographic behavior of this material and its property of activating procollagenase indicate it to be identical to the ESAF isolated from other sources. The biological activity of ESAF from human vitreous was demonstrated by its ability to induce positive responses in the rabbit corneal pocket, and in the chick chorioallantoic membrane and yolk sac membrane tests.

Angiogenesis Inducing Agents↗
PubMed1989

[The characteristics of the F1 hybrids of spontaneously hypertensive and normotensive rats].

The F1 hybrids between SHR and WKY rats develop borderline hypertension and may be used as a model for the study of interaction of hereditary and environmental factors in the development of hypertension. In order to characterize this model, arterial pressure level, body mass and some behavioral features were studied in the SHR, WKY rats and in two types of their reciprocal F1 hybrids. The arterial pressure level of the F1 hybrids was clove to limits of the borderline hypertension and to midparental level. F1 hybrids differ from normotensive controls in their behavioral activity and in salt appetite. These peculiarities may be related to an enhanced sensitivity of F1 rats to stresses and to salt loads. No essential reciprocal or sex differences were found in the character of inheritance of the features under study. Therefore both types of reciprocal F1 hybrids and both sexes of hybrid animals may be used as a model of the borderline hypertension.

Animals↗
PubMed1982

Isolation and chemical characterization of two new vitamin D metabolites produced by the intestine. 1,25-Dihydroxy-23-oxo-vitamin D3 and 1,25,26-trihydroxy-23-oxo-vitamin D3.

Two new vitamin D metabolites were isolated in pure form from incubations of 53 nM 1,25-dihydroxyvitamin D3 with homogenates of small intestinal mucosa of vitamin D-replete chicks. The birds were injected intravenously with 8 to 9 nmol of 1,25-dihydroxyvitamin D3/100 g body weight 5 to 8 h before death. The isolation involved methanol-chloroform extraction and four successive chromatographic procedures (Sephadex LH-20 and high performance liquid chromatography). Chemical structures of the metabolites are proposed on the basis of (a) their chromatographic behavior, (b) their mass spectra, and (c) ultraviolet absorption spectra. They are identified as 1 alpha,25-dihydroxy-23-oxo-vitamin D3 and 1 alpha,25,26-trihydroxy-23-oxo-vitamin D3. Neither of the two new metabolites is produced by the intestinal mucosa when 1,25S,26-trihydroxyvitamin D3 is used as a substrate.

Animals↗
PubMed1994

Localized malignant mesothelioma. A clinicopathologic and flow cytometric study.

Six examples of malignant mesothelioma appearing as a localized pleural mass are described. There were four women and two men, ranging in age from 42 to 76 years. A history of asbestos exposure was obtained from three patients. The tumors ranged in size from 2.8 to 10 cm. Two were pedunculated and four were sessile with broad-based pleural attachments. Histologically, three tumors were purely epithelioid and three were biphasic. Immunohistochemical stains in all six cases were positive for cytokeratin and negative for carcinoembryonic antigen. Five were also positive for epithelial membrane antigen. Five were negative for Leu-M1, while one showed focal staining in a peripheral membrane pattern. Electron microscopy in two purely epithelioid tumors showed long, thin microvilli, well-developed desmosomes, and numerous tonofilaments. Flow cytometry showed an aneuploid DNA content in four tumors and a diploid content in one. Flow cytometry in five cases identified a DNA aneuploid cell population in four tumors and a diploid population in one. Three patients showed signs of local recurrences 4, 7, and 18 months after excision and died of their disease 12, 10, and 24 months after diagnosis, respectively. Three patients are well with no evidence of disease 8, 24, and 96 months after diagnosis. These findings indicate that malignant mesotheliomas of the pleura may rarely appear as a localized mass. The biologic behavior of such tumors is difficult to predict, but some patients survive disease-free for a long time after surgical excision.

Adult↗
PubMed1994

Prevalence of gastrointestinal symptoms in obese and normal weight binge eaters.

OBJECTIVES: Disturbances in gastrointestinal function may result from disordered eating and may lead to increases in gastrointestinal (GI) symptoms. We compared GI symptoms in obese and non-obese binge eaters and non-binge eaters. METHODS: One hundred nineteen obese and 77 normal-weight females completed a questionnaire on bowel symptoms and binge eating behaviors for the previous 3 months. Based on binge behaviors and body mass index (> 30 kg/m2), individuals were grouped as obese binge eaters (n = 73), obese non-binge eaters (n = 43), non-obese binge eaters (n = 14), and normal-weight controls (n = 61). RESULTS: Obese binge eaters reported more upper GI symptoms than normal controls or obese non-binge eaters (p < 0.001). Compared with normal controls, nausea, vomiting, and bloating was 2-4 times more prevalent in both binge eating groups. Indigestion was more prevalent in both obese groups. Obese binge eaters reported more lower GI symptoms than normal-weight controls (p < 0.05). Binge eating in both weight groups was associated with more frequent abdominal pain and dyschezia. Obesity was associated with more frequent constipation, diarrhea, straining, and flatus, whether or not subjects reported binge eating. Chi-square showed a significant association between obesity, binge eating, and symptoms of irritable bowel syndrome, using the Manning criteria. CONCLUSIONS: Specific GI symptoms were associated with binge eating and obesity. Overall, symptoms were more prevalent and more severe in obese binge eaters. The high prevalence of GI symptoms in obese patients who indulge in binge eating should be considered in their evaluation and treatment.

Analysis of Variance↗
PubMed2006

Body mass index and body weight perception as risk factors for internalizing and externalizing problem behavior among adolescents.

PURPOSE: To examine the relationship between body mass index (BMI), body weight perception (BWP), and indicators of internalizing and externalizing distress and social, attention and thought problems in a large representative sample of Dutch youth. METHODS: A total of 1826 pupils in the eighth grade of primary education and 5730 students in the first four years of secondary education gave their height and weight to obtain an estimate of their BMI. They reported their evaluation of their body weight and completed Achenbach's Youth Self-Report (YSR) (1991), which assesses eight types of problem behavior. Data were analyzed in a multivariate framework with BMI and BWP as predictors and the YSR scores on different kinds of problem behavior as dependent variables, controlling for background characteristics. RESULTS: Both BMI and BWP are associated with internalizing and externalizing problem behavior, and social, attention and thought problems. Multivariate tests show that BWP is more closely linked to problem behavior than BMI. Adolescents who were either underweight or overweight but considered themselves in good shape had no more problems than the group with normal BMI and BWP 'good'. The perception of being 'too thin' and particularly the perception of being 'too heavy' best predict problem behavior in both male and female adolescents. Overweight youngsters with an adequate perception of their weight have less somatic complaints than their normal-weight peers who perceive themselves as too heavy, but they show higher withdrawnness, social problems, and anxiety/depression. CONCLUSIONS: Adolescent girls are more dissatisfied with their weight than boys; however, the relationship between weight perception and problem behavior is the same for both genders.

Adolescent↗
PubMed2001

Self-reported body mass index and health-related quality of life: findings from the Behavioral Risk Factor Surveillance System.

OBJECTIVE: To examine the relationship between self-reported body mass index (BMI) and health-related quality of life in the general adult population in the United STATES: RESEARCH METHODS AND PROCEDURES: Using data from 109,076 respondents in the 1996 Behavioral Risk Factor Surveillance System, we examined how self-reported BMI is associated with five health-related quality of life measures developed by the Centers for Disease Control and Prevention for population health surveillance. RESULTS: After adjusting for age, gender, race or ethnicity, educational attainment, employment status, smoking status, and physical activity status, participants with a self-reported BMI of <18.5 kg/m(2) and participants with a self-reported BMI of > or =30 kg/m(2) reported impaired quality of life. Compared with persons with a self-reported BMI of 18.5 to <25 kg/m(2), odds ratios (ORs) of poor or fair self-rated health increased among persons with self-reported BMIs of <18.5 (1.57, 95% confidence interval [CI]: 1.31 to 1.89), 25 to <30 kg/m(2) (1.12, 95% CI: 1.04 to 1.20), 30 to <35 kg/m(2) (1.65, 95% CI: 1.50 to 1.81), 35 to <40 kg/m(2) (2.58, 95% CI: 2.21 to 3.00), and > or =40 kg/m(2) (3.23, 95% CI: 2.63 to 3.95); ORs for reporting > or =14 days of poor physical health during the previous 30 days were 1.44 (95% CI: 1.21 to 1.72), 1.04 (95% CI: 0.96 to 1.14), 1.32 (95% CI: 1.19 to 1.47), 1.80 (95% CI: 1.52 to 2.13), and 2.37 (95% CI: 1.90 to 2.94), respectively; ORs for having > or =14 days of poor mental health during the previous 30 days were 1.18 (95% CI: 0.97 to 1.42), 1.02 (95% CI: 0.95 to 1.11), 1.22 (95% CI: 1.10 to 1.36), 1.68 (95% CI: 1.42 to 1.98), and 1.66 (95% CI: 1.32 to 2.09), respectively. DISCUSSION: In the largest study to date, low and increased self-reported BMI significantly impaired health-related quality of life. Particularly, deviations from normal BMI affected physical functioning more strongly than mental functioning.

Adult↗
PubMed2006

Mobility of mass-reared diapaused and nondiapaused Cydia pomonella (Lepidoptera: Tortricidae): effect of different constant temperatures and lengths of cold storage.

Desirable behavioral attributes in mass-reared insects should include the ability to perform favorably under the various environmental conditions they encounter upon release in the field. Insect quality also may be influenced by storage conditions and storage duration before field release. We studied the effects of three different constant ambient temperatures (15, 20, and 25 degrees C) and different lengths of adult cold storage (0, 24, 48, and 72 h at 2 degrees C) on the locomotor activity of adult Cydia pomonella (L.) mass reared through diapause or standard production protocols. Mobility was assessed in actographs housed in a climate controlled chamber; tests lasted 24 h. We found that adult mobility was significantly higher for both males and females at 25 and 20 degrees C than at 15 degrees C. There were no significant differences in mobility in moths reared through diapause or nondiapaused production protocols. In addition, temporal analysis of the data revealed a significant shift in the diel patterns of activity for both genders when adults were tested at the three different temperatures. Moths exposed to the lower temperature shifted their activity pattern from evening to mid-afternoon, which may be an adaptive behavior to take advantage of the expected warmest period of the day. Diapaused adults were significantly less mobile when stored in the cold (24, 48, or 72 h of storage at 2 degrees C) than were diapaused adults that did not experience cold storage (0 h). However, length of time in cold storage did not significantly influence the mobility of adult codling moths reared through standard production protocols.

Animal Husbandry↗
PubMed1999

Hormone replacement therapy and hip fracture risk: effect modification by tobacco smoking, alcohol intake, physical activity, and body mass index.

The authors prospectively studied the overall effect of hormone replacement therapy (HRT) on hip fracture risk and the effect modification by behavioral habits and body mass index. A total of 6,159 postmenopausal women from the Copenhagen Center for Prospective Population Studies, Copenhagen, Denmark, with initial examination in 1976-1978 were followed until 1993. During follow-up 363 hip fractures were identified. Women who reported current use of HRT had a lower risk of hip fracture as compared with women who were nonusers (relative risk (RR) = 0.71; 95 percent confidence interval (CI): 0.50, 1.01). Use of HRT was associated with a lower risk of hip fracture in former (RR = 0.55; 95 percent CI: 0.22, 1.37) and current (RR = 0.61; 95 percent CI: 0.38, 0.99) smokers but not in never smokers (RR = 1.10; 95 percent CI: 0.60, 2.03). HRT was also associated with lower risk of hip fracture among alcohol drinkers (RR = 0.36; 95 percent CI: 0.14, 0.90) and among sedentary women (RR = 0.42; 95 percent CI: 0.18, 0.98) but not among nondrinkers (RR = 0.99; 95 percent CI: 0.61, 1.61) and physically active women (RR = 0.92; 95 percent CI: 0.42, 2.04). There was no evidence of interaction between use of HRT and body mass index. In conclusion, the protective effect of HRT on hip fracture appears to be strongest in women who ever smoked, in women who drink alcohol, and in women who are sedentary. The results suggest that history of behavioral habits offers important information concerning the probable degree of protection against hip fracture afforded by HRT.

Adult↗
PubMed2002

Singular self-preserving regimes of coagulation processes.

The late stages of the time evolution of disperse systems when either coagulation alone governs the temporal changes of particle mass spectra or simultaneous condensation complicates the evolution process are studied under the assumption that the condensation efficiencies and coagulation kernels are homogeneous functions of the particle masses, with gamma and lambda being their homogeneity exponents, respectively. In considering the asymptotic behavior of the particle mass distributions the renormalization-group approach is applied to three types of coagulating systems: free coagulating systems in which coagulation alone is responsible for disperse particle growth; source-enhanced coagulating systems, where an external spacially uniform source permanently adds fresh small particles, with the particle production being a power function of time; and coagulating-condensing systems in which a condensation process accompanies the coagulation growth of disperse particles. The particle mass distributions of the form N(A)(g,t)=A(t)psi(gB(t)) are shown to describe the asymptotic regimes of particle growth in all the three types of coagulating systems (g is the particle mass). The functions A(t) and B(t) are normally power functions of time whose power exponents are found for all possible regimes of coagulation and condensation as the functions of lambda and gamma. The equations for the universality function psi(x) are formulated. It is shown that in many cases psi(x) proportional, variant x(-sigma) (sigma > 1) at small x, i.e., the particle mass distributions are singular. The power exponent sigma is expressed in terms of lambda and gamma. Two exactly soluble models illustrate the general theoretical consideration.

Journal Article↗
PubMed2005

Psychosocial and environmental correlates of adolescent sedentary behaviors.

OBJECTIVE: To determine correlates of sedentary behaviors in adolescents through the examination of psychosocial and environmental variables. METHOD: The study used a cross-sectional design to evaluate an ethnically diverse clinic-based sample of 878 adolescents who were 11 to 15 years old. Bivariate and multivariate analyses were stratified by gender to assess correlates of sedentary behaviors occurring on the most recent nonschool day (television viewing, computer video games, sitting listening to music, and talking on the phone). RESULTS: For girls, age, family support, television/video rules, and hills in the neighborhood were associated with sedentary behaviors. Furthermore, psychological constructs such as self-efficacy, enjoyment, change strategies, and pros and cons of change emerged as correlates of sedentary behaviors. A moderator effect revealed that the proportion of girls in the low-BMI group decreased with increased self-efficacy, whereas the proportion of girls in the high-BMI group did not vary significantly by self-efficacy. For boys, age, ethnicity, BMI, cons of change, and self-efficacy were associated with sedentary behaviors. CONCLUSIONS: This study provides evidence of factors associated and not associated with adolescent sedentary behaviors. Similar to physical activity, measures of specific psychosocial constructs of sedentary behavior demonstrated important associations. The results highlight the need for additional examination of the correlates of sedentary behavior to determine which correlates are mechanisms of behavior change.

Adolescent↗
PubMed1998

Behavioral changes in fasting emperor penguins: evidence for a "refeeding signal" linked to a metabolic shift.

This study examines the relationships between metabolic status and behavior in spontaneously fasting birds in the context of long-term regulation of body mass and feeding. Locomotor activity, escape behavior, display songs, body mass, and metabolic and endocrine status of captive male emperor penguins were recorded during a breeding fast. We also examined whether body mass at the end of the fast affected further survival. The major part of the fast (phase II) was characterized by the maintenance of a very low level of locomotor activity, with almost no attempt to escape, by an almost constant rate of body mass loss, and by steady plasma levels of uric acid, beta-hydroxybutyrate, and corticosterone. This indicates behavioral and metabolic adjustments directed toward sparing energy and body protein. Below a body mass of approximately 24 kg (phase III), spontaneous locomotor activity and attempts to escape increased by up to 8- and 15-fold, respectively, and display songs were resumed. This probably reflected an increase in the drive to refeed. Simultaneously, daily body mass loss and plasma levels of uric acid and corticosterone increased, whereas plasma levels of beta-hydroxybutyrate decreased. Some experimental birds were seen again in following years. These findings suggest that at a threshold of body mass, a metabolic and endocrine shift, possibly related to a limited availability of fat stores, acts as a "refeeding signal" that improves the survival of penguins to fasting.

3-Hydroxybutyric Acid↗
PubMed2002

Dimensionality and the dynamics of human unstable equilibrium.

Maintaining an unstable equilibrium requires that multiple joints be coordinated so that the center of mass is kept above the base of support. The authors' aim in the present study was to discover the underlying dynamics of local (foot, hip, or head) and global (center of mass) components involved in balance control and how those dynamics are affected by changes in the available information. Participants (N = 6) had to maintain their balance on an unstable platform. Using dimensional analyses (largest Lyapunov exponent and correlation dimension), the authors examined the active degrees of freedom involved in balance control. Results indicated a similarity in dimension between local (joints) and global (center of mass) components, between a fixed point and a limit cycle. The behavior of the center of mass was found to be more predictable than the behavior of its local constituents. In addition, the available visual information affected the predictability of the postural behavior, which suggests that vision is used in the stabilization of the low-dimensional dynamics underlying balance control.

Algorithms↗
PubMed2004

Evaluation of 14C abundance in soil respiration using acclerator mass spectrometry.

To clarify the behavior of 14C in terrestrial ecosystems, 14C abundance in soil respiration was evaluated in an urban forest with a new method involving a closed chamber technique and 14C measurement by accelerator mass spectrometry (AMS). Soil respiration had a higher Delta14C than the contemporary atmosphere. This indicates that a significant portion of soil respiration is derived from the decomposition of soil organic matter enriched in 14C by atmospheric nuclear weapons tests, with a notable time lag between atmospheric 14C addition and re-emission from soil. On the other hand, delta14C in soil respiration demonstrated that 14C abundance ratio itself in soil-respired CO2 is not always high compared with that in atmospheric CO2 because of the isotope fractionation during plant photosynthesis and microbial decomposition of soil organic matter. The Delta14C in soil respiration was slightly lower in August than in March, suggesting a relatively high contribution of plant root respiration and decomposition of newly accumulated and/or 14C-depleted soil organic matter to the total soil respiration in August.

Air Pollutants, Radioactive↗
PubMed1999

Flexible vs. Rigid dieting strategies: relationship with adverse behavioral outcomes.

This study was designed to test the hypothesis that different types of dieting strategies are associated with different behavioral outcomes by investigating the relationship of dieting behaviors with overeating, body mass and mood. A sample of 223 adult male and female participants from a large community were studied. Only a small proportion of the sample (18%) was seeking weight loss treatment, though almost half (49.3%) of the subjects were significantly overweight (body mass index, BMI>30). Subjects were administered questionnaires measuring dietary restraint, overeating, depression and anxiety. Measurements of height and weight were also obtained in order to calculate BMI. Canonical correlation was performed to evaluate the relationship of dietary restraint variables with overeating variables, body mass, depression and anxiety. The strongest canonical correlation (r=0.65) was the relationship between flexible dieting and the absence of overeating, lower body mass and lower levels of depression and anxiety. The second strongest canonical correlation (r=0.59) associated calorie counting and conscious dieting with overeating while alone and increased body mass. The third canonical correlation (r=0.57) found a relationship between low dietary restraint and binge eating. The results support the hypothesis that overeating and other adverse behaviors and moods are associated with the presence or absence of certain types of dieting behavior.

Adult↗
PubMedDate not supplied

Attitudes toward bulimic behaviors in two generations: the role of knowledge, body mass, gender, and bulimic symptomatology.

The perceived commonality and acceptability of symptoms of bulimia, as well as associated variables including gender, generation, knowledge of bulimia, body mass index, and bulimic symptomatology, were assessed. These views were explored in a sample of college students (N = 155 male; N = 173 female) and their parents (N = 194 mothers; N = 163 fathers). Females perceived bulimic symptoms to be more common than males, and students perceived them to be more common than their parents. Students perceived bulimic symptoms to be more acceptable than their parents. Females had higher levels of bulimic symptomatology, particularly daughters. Stepwise simultaneous regression analyses revealed that one's own level of bulimic symptomatology was the primary predictor of one's attitudes toward the commonality and acceptability of bulimic symptoms. Bulimic symptomatology was primarily predicted from perceptions of the acceptability of bulimic symptoms and body mass index. Results suggest that college-age students may be at greater risk for the development of bulimia nervosa because of their greater tolerance of these symptoms; alternatively, people endorsing higher levels of bulimic symptomatology may adjust their attitudes, perceiving bulimic symptoms to be more tolerable, in order to alleviate the dissonance between their attitudes and behaviors.

Adolescent↗
PubMed1994

Lagrangian molecular dynamics using selected conformational degrees of freedom, with application to the pseudorotation dynamics of furanose rings.

Using internal conformational degrees of freedom for biopolymers as natural variables, and introducing a Lagrangian dynamics approach, one can simulate time-dependent processes over a much longer time scale than in classical Newtonian molecular dynamics (MD) techniques. Two factors contribute to this: a substantial reduction in the number of degrees of freedom and a very large increase in the size of the time step. We present the Lagrangian equations of motion for repuckering transitions in model furanose (F), ribose (R), and 2'-deoxyribose (dR) ring systems using the pseudorotation phase angle as the single dynamic variable. As in most Lagrangian analyses, the effective masses for the R and dR models are dependent on conformation, and we test the behavior of this variable mass (VM) model. Since the variation in effective mass is small, the VM model is compared with a simplified constant mass (CM) model, which is shown to be an excellent approximation. The equations of motion for the CM and VM models are integrated with the leapfrog and the iterative leapfrog algorithms, respectively. The Lagrangian dynamics approach reduces the number of degrees of freedom from about 40 to 1, and allows the use of time steps on the order of 20 fs, about an order of magnitude greater than is used in conventional MD simulations.

Biopolymers↗