Adiposity is related to decrements in cardiorespiratory fitness in obese and normal-weight children.

BACKGROUND: Obese children are typically less physically active than their normal-weight peers and are often assumed to be 'unfit'. OBJECTIVE: Investigate the relationships between adiposity, physical activity levels and cardiorespiratory fitness (CRF) in obese and normal-weight children. A secondary aim was to examine obese/normal-weight differences in CRF. METHODS: Obese (N = 107) and normal-weight (N = 132) 10-13-year-olds participated. Fat-free mass (FFM), percent fat, physical activity and peak oxygen uptake (VO2peak ) were assessed. Analyses were adjusted for socioeconomic status (SES). RESULTS: Higher percent fat was inversely associated with VO2peak normalized for mass (r = -0.780, P < 0.001) even after controlling for physical activity (r = -0.673, P < 0.001). While higher percent fat was also inversely associated with VO2peak normalized for FFM, this was only significant in males (r = -0.247, P = 0.004) and did not persist after controlling for physical activity (r = -0.059 P = 0.526). Compared with normal-weight children, obese children had higher absolute VO2peak , lower VO2peak corrected for mass (P ≤ 0.009) and lower VO2peak corrected for FFM (P = 0.041) that did not persist after controlling for SES (P = 0.086). CONCLUSION: Obesity-related inefficiencies in CRF were evident. Higher adiposity was associated with poorer CRF relative to mass, irrespective of physical activity levels. However, low physical activity levels may be responsible for associations between adiposity and CRF relative to FFM seen in boys, indicating the importance of encouraging physical activity.

Day-to-day physical functioning and disability in obese 10- to 13-year-olds.

UNLABELLED: What is already known about this subject? Compared with their healthy-weight peers, children with obesity have; impaired physical health-related quality of life reduced physical activity levels reduced capacity to perform certain weight-bearing tasks in field-based fitness tests What this study adds? First investigation of obesity-related disability in children using the International Classification for Functioning, Disability and Health framework for Children and Youth. Obesity in children appears to be associated with disability impacting basic locomotor skills and physical health-related quality of life. Children's participation in key life areas related to physical functioning appears to be minimally impacted by obesity. OBJECTIVE: The aim of this study was to investigate whether obesity is related to impaired day-to-day physical functioning and disability in children. METHODS: An observational case-control study was conducted in three Australian states. Obese (n = 107) and healthy-weight (n = 132) 10- to 13-year-olds (132 male, 107 female) were recruited via media advertisements. Assessment of body composition (dual energy X-ray absorptiometry), locomotor capacity (six-minute walk test [6MWT], timed up and down stairs test [TUDS] and timed up and go [TUG]) and child-reported physical health-related quality of life (HRQoL) were undertaken. Participants wore an accelerometer for 8 days and completed two use-of-time telephone interviews to assess participation in key life areas. RESULTS: Compared with their healthy-weight counterparts, obese children had lower physical HRQoL scores (P < 0.01) and reduced locomotor capacity (TUDS z-score, TUG and 6MWT; P < 0.01). Higher percent body fat was significantly related to lower physical HRQoL scores (r = -0.48, P < 0.01), slower performance times for the TUDS and TUG (r = 0.59 and 0.26 respectively, P < 0.01), shorter 6MWT distances (r = -0.51, P < 0.01) and reduced time spent in community participation activities (r = -0.23, P < 0.01). CONCLUSIONS: As anticipated, obesity appears to undermine physical functioning in children, including the capacity to perform basic locomotor skills yet, unexpectedly, participation in key life areas related to physical functioning appeared largely unaffected.

Genome-wide association studies of female reproduction in tropically adapted beef cattle.

The genetics of reproduction is poorly understood because the heritabilities of traits currently recorded are low. To elucidate the genetics underlying reproduction in beef cattle, we performed a genome-wide association study using the bovine SNP50 chip in 2 tropically adapted beef cattle breeds, Brahman and Tropical Composite. Here we present the results for 3 female reproduction traits: 1) age at puberty, defined as age in days at first observed corpus luteum (CL) after frequent ovarian ultrasound scans (AGECL); 2) the postpartum anestrous interval, measured as the number of days from calving to first ovulation postpartum (first rebreeding interval, PPAI); and 3) the occurrence of the first postpartum ovulation before weaning in the first rebreeding period (PW), defined from PPAI. In addition, correlated traits such as BW, height, serum IGF1 concentration, condition score, and fatness were also examined. In the Brahman and Tropical Composite cattle, 169 [false positive rate (FPR) = 0.262] and 84 (FPR = 0.581) SNP, respectively, were significant (P < 0.001) for AGECL. In Brahman, 41% of these significant markers mapped to a single chromosomal region on BTA14. In Tropical Composites, 16% of these significant markers were located on BTA5. For PPAI, 66 (FPR = 0.67) and 113 (FPR = 0.432) SNP were significant (P < 0.001) in Brahman and Tropical Composite, respectively, whereas for PW, 68 (FPR = 0.64) and 113 (FPR = 0.432) SNP were significant (P < 0.01). In Tropical Composites, the largest concentration of PPAI markers were located on BTA5 [19% (PPAI) and 23% (PW)], and BTA16 [17% (PPAI) and 18% (PW)]. In Brahman cattle, the largest concentration of markers for postpartum anestrus was located on BTA3 (14% for PPAI and PW) and BTA14 (17% PPAI). Very few of the significant markers for female reproduction traits for the Brahman and Tropical Composite breeds were located in the same chromosomal regions. However, fatness and BW traits as well as serum IGF1 concentration were found to be associated with similar genome regions within and between breeds. Clusters of SNP associated with multiple traits were located on BTA14 in Brahman and BTA5 in Tropical Composites.

Health-related quality of life in obese children and adolescents.

OBJECTIVE: This review addresses the effect of overweight and obese weight status on pediatric health-related quality of life (HRQOL). METHOD: Web of Science, Medline, CINAHL, Cochrane Library, EMBASE, AMED and PubMed were searched for peer-reviewed studies in English reporting HRQOL and weight status in youth (<21 years), published before March 2008. RESULTS: Twenty-eight articles were identified. Regression of HRQOL against body mass index (BMI) using pooled data from 13 studies utilizing the Pediatric Quality of Life Inventory identified an inverse relationship between BMI and pediatric HRQOL (r=-0.7, P=0.008), with impairments in physical and social functioning consistently reported. HRQOL seemed to improve with weight loss, but randomized controlled trials were few and lacked long-term follow-up. CONCLUSIONS: Little is known about the factors associated with reduced HRQOL among overweight or obese youth, although gender, age and obesity-related co-morbidities may play a role. Few studies have examined the differences in HRQOL between community and treatment-seeking samples. Pooled regressions suggest pediatric self-reported HRQOL can be predicted from parent proxy reports, although parents of obese youths tend to perceive worse HRQOL than children do about themselves. Thus, future research should include both pediatric and parent proxy perspectives.

Development of a scale to measure discomfort during pregnancy.

During pregnancy fundamental changes occur in a woman's body that make physical discomforts almost unavoidable. Extensive literature searches revealed that there was no psychometrically acceptable tool available to assess accurately maternal physical discomfort. This paper presents the procedures undertaken to develop the Maternal Physical Discomfort Scale (MPDS), an assessment instrument designed to quantify the type and number of maternal physical discomforts. The MPDS, a scale consisting of 36 items, was developed and psychometrically evaluated using factor analysis, item response theory and reliability measures. The initial version of the scale was validated by a sample of 307 pregnant women. Based on the result from this sample, the MPDS was modified to 33 items and validated by a further sample of 125 pregnant women. The MPDS developed in this study was demonstrated to have content and construct validity and to be reliable.

Effect of nutrition during pregnancy on fetal growth and survival in Fec(B) Booroola x South Australian Merino ewes.

The effect of nutritional manipulation during mid and late pregnancy on fetal growth and survival in high fecundity (Fec(B) Fec(+)) Merino ewes was examined. A total of 4 treatment groups was utilized in each of 3 years (1987, 1988 and 1989); and 2 groups were given low nutrition during mid pregnancy while 2 groups received high nutrition during this period. One group from each of these treatments subsequently received a high protein diet 1 to 2 weeks prior to term. Differential feeding during mid pregnancy resulted in the high and low treatment groups varying by 7.5 and 5.0 kg liveweight at Days 100 and 135 of pregnancy, respectively. Fetal survival was not improved by variation in nutritional intake during mid pregnancy (P>0.05) and neither were placental and fetal growth (P>0.05), as indicated by observations on cotyledon diameter and fetal head width, respectively. However, fetal survival during late pregnancy was reduced by a high level of nutrition during both mid and late pregnancy (P<0.05).

Factors influencing lamb survival in a high fecundity Booroola Merino x South Australian Merino flock.

The effects of year of lambing, age of ewe and litter size on lamb survival and birthweight, and the effects of ewe mating weight and pregnancy wastage (ovulation rate minus litter size) on birthweight were examined in Booroola Merino x South Australian Merino ewes. Year of lambing, litter size and their interaction were significant (P<0.001) sources of variation for lamb survival. When birthweight was included as a linear and quadratic covariate for lamb survival, year of lambing and litter size and their interaction remained as statistically significant sources of variation. Year of lambing, litter size and pregnancy wastage contributed significantly (P<0.05) to variation in birthweight. Ewe liveweight at mating was not an important source of variation (P>0.05). Birthweight was significantly (P<0.05) reduced with an increase in pregnancy wastage. Improvement of birthweight of multiple birth lambs has some potential for increasing lamb survival. Other factors influencing lamb survival (year of lambing, litter size, pregnancy wastage) require further study so that strategies for reducing lamb loss in high fecundity Merino flocks can be developed.

Fertilization and embryo loss in Booroola Merino x South Australian Merino ewes: Effect of the F gene.

The effects of Booroola genotype (F+, ++); the number of ovulations per ewe (one, two or three); and the age of a ewe (2.5 yr vs 3.5 to 6.5 yr) on the percentage of ova fertilized, embryo loss and fetal loss were examined in Booroola x South Australian Merino ewes slaughtered on Days 4, 21 and 90 after insemination. Ewes slaughtered on Day 90 were examined by real-time ultrasound imaging (RUI) on Day 45. Fertilization failure was independent of ewe genotype, ovulation rate and age of ewe, and it was not an important source of wastage (F+, 9.4%; ++, 6.7%). Most embryo loss occurred during the first 21 d (F+, 54.7%; ++, 40.3%). Interpretation of the effects of genotype and ovulation rate on embryo wastage measured on Days 21, 45 and 90 was obscured by significant (P < 0.05) genotype and ovulation rate interactions with the day of slaughter/RUI. The effect of age on embryo loss was not significant (P > 0.05). Reasons for the high rate of wastage observed in this experiment require further study.

The effectiveness of an interactive videodisc qualitative assessment training program.

This study was designed to investigate the effect of an interactive videodisc motor skill assessment training program on the development of preservice and inservice teachers' qualitative assessment proficiency on two motor skills: the overhand throw and catch. Twenty-seven preservice and 27 inservice physical education teachers were randomly assigned to one of three treatment conditions: interactive videodisc (IVD), teacher-directed (TD), or self-directed (SD). Motor skill qualitative assessment accuracy was evaluated on a pre- and post-test basis using a 50-item motor skill assessment accuracy test (10 performances rated on 5 components) for each skill. Analysis of covariance results indicated significant main effects for treatment for both skills. Post hoc tests revealed that for the overhand throw, the IVD and TD groups were superior to the SD group but not different from each other. For the catch, the IVD group was found to be superior to both the TD and SD groups. These findings are discussed in relation to the advantages of interactive videodisc in terms of efficiency and user independence and with comparable findings in other educational applications.

Uterine presensitization and embryo survival and growth in Booroola Merino x South Australian Merino ewes.

The fertility enhancing effects of semen were examined following the intra-uterine insemination of killed spermatozoa plus seminal plasma 17 d prior to insemination with viable spermatozoa. Three experiments were conducted: two on 1.5-yr old and 2.5 to 5.5 yr-old Booroola Merino x South Australian Merino ewes in 1986 and one on 1.5 yr-old ewes in 1987. Differences between treatment and control groups for the percentage of ewes exhibiting estrus by Days 21 and 35 following fertile insemination, the percentage of ewes with viable embryos at Day 35, the number and weight of viable embryos per ewe, the nubmer of caruncular implantation sites and the progesterone level were not statistically significant (P>0.05). There were no statistically significant treatment by experiment interactions for any of the variables examined. Inflammation and edema of the endometrial tissue was not observed following the presensitization treatment.

The use of physiological traits in genetic selection for litter size in sheep.

The objective was to quantify and compare the genetic responses by direct selection on litter size, by indirect selection through a physiological trait and by combined selection, combining litter size and the physiological trait in a selection index. Three kinds of physiological trait were considered, male sex-limited (e.g. testes size), female sex-limited (ovulation rate) and traits measurable in both sexes (gonadotrophin levels). The results are presented graphically and cover a wide range of possible situations and show the size of the responses for different parameters of the physiological trait. There is usually scope for improvement in the rate of response with combined selection, and also in special cases (high heritability and genetic correlation) with indirect selection. The increases in predicted response may range from zero to two or three times the direct response, depending on the genetic parameters. However, the need for reliable estimates of the genetic parameters is stressed, because the predicted responses might otherwise be overestimated and the selection effort misplaced.

Comparison of labetalol, hydrallazine, and propranolol in the therapy of moderate hypertension.

The efficacy of labetalol, an alpha and beta adrenoceptor blocking drug, has been compared with that of placebo, of propranolol alone, of hydrallazine alone, and of hydrallazine plus propranolol in combination in a randomized double-blind, fixed-dose crossover trial. Labetalol (300 mg twice a day) was equally effective with propranolol (80 mg twice a day), and more effective than hydrallazine (50 mg twice a day) alone. The effect of labetalol was comparable with that of hydrallazine plus propranolol when the patient was standing, but less potent with the patient in the supine position. Side effects were few.

The persistence of dextran 70 in blood plasma following its infusion, during surgery, for prophylaxis against thromboembolism.

An infusion of dextran (mean molecular weight 70000) in normal saline (either 1 litre or 500 ml) was given to patients undergoing hysterectomy. The infusion was started at induction of anaesthesia and continued throughout the operation and for up to 5 h thereafter. The rate of elimination of dextran was independent of the dose given. The time to eliminate half the dose was nearly two days and up to 10% was still present in the circulation after one week. The persistence of dextran in the plasma in these amounts and for this length of time may have considerable implications in the prophylaxis of postoperative deep venous thrombosis.