Testing ecological and universal models of body shape and child health using a global sample of infants and young children

Aim: To test whether a risk of child illness is best predicted by deviations from a population-specific growth distribution or a universal growth distribution.

Subjects and methods: Child weight for height and child illness data from 433 776 children (1–59 months) from 47 different low and lower income countries are used in regression models to estimate for each country the child basal weight for height. This study assesses the extent to which individuals within populations deviate from their basal slenderness. It uses correlation and regression techniques to estimate the relationship between child illness (diarrhoea, fever or cough) and basal weight for height, and residual weight for height.

Results: In bivariate tests, basal weight for height z-score did not predict the country level prevalence of child illness (r²?=?–0.01, n?=?47, p?=?0.53), but excess weight for height did (r²?=?0.14, p?p?n?=?433 776) and basal weight for height was not (beta?=?0.20, p?=?0.27). Deviations from country-specific basal weight for height were negatively associated with the likelihood of illness (beta?=?–0.13, p?Conclusion: These results are consistent with the idea that populations may differ in their body slenderness, and that deviations from this body form may predict the risk of childhood illness.     

Immediate effects of foot orthoses on pain during functional tasks in people with patellofemoral osteoarthritis: A cross-over,proof-of-concept study

Background

The purpose of the study was to determine whether prefabricated foot orthoses immediately reduce pain during functional tasks in people with patellofemoral osteoarthritis, compared to flat insoles and shoes alone.

Root cause analysis of limitations of virtual crossmatch for kidney allocation to highly-sensitized patients

Efficient allocation of deceased donor organs depends upon effective prediction of immunologic compatibility based on donor HLA genotype and recipient alloantibody profile, referred to as virtual crossmatching (VCXM). VCXM has demonstrated utility in predicting compatibility, though there is reduced efficacy for patients highly sensitized against allogeneic HLA antigens. The recently revised deceased donor kidney allocation system (KAS) has increased transplantation for this group, but with an increased burden for histocompatibility testing and organ sharing. Given the limitations of VCXM, we hypothesized that increased organ offers for highly-sensitized patients could result in a concomitant increase in offers rejected due to unexpectedly positive crossmatch. Review of 645 crossmatches performed for deceased donor kidney transplantation at our center did not reveal a significant increase in positive crossmatches following KAS implementation. Positive crossmatches not predicted by VCXM were concentrated among highly-sensitized patients. Root cause analysis of VCXM failures identified technical limitations of anti-HLA antibody testing as the most significant contributor to VCXM error. Contributions of technical limitations including additive/synergistic antibody effects, prozone phenomenon, and antigens not represented in standard testing panels, were evaluated by retrospective testing. These data provide insight into the limitations of VCXM, particularly those affecting allocation of kidneys to highly-sensitized patients.     

甘肃兰州市区城镇居民体成分分析

目的分析甘肃兰州市区城镇成人居民体成分和脂肪分布随年龄变化的特点及发展趋势,为改善居民的身体状况提供理论依据。方法采用生物电阻抗法(日本产MC-180型人体成分分析仪)对1357名男女居民进行测试,对测试结果进行统计学分析。结果 20~79岁年龄段男女性居民体脂率、腰臀比(WHR)随年龄的增长而递增。蛋白质总量、肌肉总量、推定骨量、身体水分、身体质量指数(BMI)值随年龄的增长呈先升后降的趋势。内脏脂肪男、女性均随年龄的增长而增长,皮下脂肪男性随年龄的增长呈先升后降的趋势,女性则随年龄的递增而递增。结论男性居民在20~岁年龄段后、女性在40~岁年龄段后出现了腹内型肥胖,男性在30~岁年龄段后,女性在60~岁年龄段后出现超重,超出了警戒范围。     

Extremes of body mass do not adversely affect the outcome of superovulation and in-vitro fertilization

The effect of extremes of body mass on ovulation is well recognized by clinicians. However, the effect of obesity and extreme underweight on the outcome of in-vitro fertilization (IVF) cycles has received relatively little attention. In a retrospective nested case-control study we examined the effect of the extremes of body mass index (BMI) on IVF-embryo transfer outcome at a university-based IVF unit. A total of 333 patients were included in the study; 76 obese patients (BMI > 27.9) with 152 controls, and 35 underweight patients (BMI < 19) with 70 controls. The patients were matched with their controls in age +/- 1 year, day 3 follicle stimulating hormone (FSH) concentration, daily dose of gonadotrophin (+/- 37.25 IU), gonadotrophin preparation and the year of treatment. The following parameters were compared between the study and control groups: duration of administration and dose of gonadotrophin, number of follicles aspirated, number of eggs, fertilization rate, number of embryos, serum oestradiol concentration on human chorionic gonadotrophin (HCG) day (peak oestradiol), clinical pregnancy rate, implantation rate, miscarriage rate, and incidence of ovarian hyperstimulation syndrome. Apart from a significantly lower peak oestradiol concentration (P = 0.009) in the obese patients, they and the underweight patients were not significantly different from their normal controls. The extremes of body mass index do not adversely affect the outcome of IVF-embryo transfer treatment. However, the obese patients had lower peak oestradiol concentrations than their normal controls despite receiving similar gonadotrophin doses.     

Effects of ageing and gender on contractile properties in human skeletal muscle and single fibres

Aim: The objective of this study is to improve our understanding of the mechanisms underlying the ageing‐ and gender‐related muscle weakness. Methods: Ageing‐ and gender‐related differences in regulation of muscle contraction have been studied in knee‐extensor muscles at the whole muscle and single muscle fibre levels in young and old sedentary men and women. In vivo knee‐extensor muscle function was measured at slow (30° s^?1) and faster (180 ° s^?1) speeds of movement. Maximum velocity of unloaded shortening (V₀) and maximum force normalized to cross‐sectional area (CSA) [specific tension (ST)] were measured in single ‘skinned’ skeletal muscle fibre segments. Results: Significant ageing‐ and gender‐related differences were observed in muscle torque. A 33–55% ageing‐related decline (P < 0.001) in maximum torque was observed irrespective of gender. At the single muscle fibre level, the ageing‐related decline in knee‐extensor muscle function was accompanied by a 20–28% decline in ST in muscle fibres expressing the type I MyHC isoform in both men and women, and a 29% decline in type IIa muscle fibre CSA, but the decreased fast‐twitch fibre size was restricted to the men. Furthermore, in both men and women, V₀ decreased in muscle cells expressing the type I and IIa MyHC isoforms. Conclusion: The present results provide evidence of specific ageing‐ and gender‐related differences in regulation of muscle contraction at the cellular level. It is suggested that these cellular changes have a significant impact on muscle function and the ageing‐related motor handicap.     

马兜铃酸Ⅰ-DNA加合物合成及电喷雾质谱法检测

目的建立体外合成及检测马兜铃酸Ⅰ(aristolochic acid I,AAⅠ)-DNA加合物的方法。方法分别采用酶活化法和化学活化法活化AAⅠ后与脱氧腺苷酸反应以合成AAⅠ-DNA加合物,优化各种反应条件,使用液相色谱/串联质谱(LC/MS/MS)法对合成的AAⅠ-DNA加合物进行结构鉴定。结果两种方法均可制得AAⅠ-DNA加合物,质谱负离子采集模式下测得其准分子离子峰m/z621,电喷雾串联质谱(ESI-MS/MS)谱图提供了丰富的结构信息。结论AAⅠ活化后能与腺嘌呤形成AAⅠ-DNA加合物,LC/MS/MS技术能够快速方便准确地检测AAⅠ-DNA加合物。     

Correlation between body mass index and postural balance

OBJECTIVE: To evaluate the correlation between body mass index (BMI) and postural balance in unipodal support. METHOD: 40 males, age 26 +/- 5 yrs, body mass 72.3 +/- 11 kg, height 176 +/_ 6 cm and BMI 23.3 +/- 3.2 kg/m(2), were submitted to functional stability tests using the Biodex Balance System (stability evaluation protocol level 2, which allows an inclination of up to 20 degrees in the horizontal plane in all directions) to compare stability with BMI. RESULTS: The general stability index showed a correlation between BMI and postural balance--measured as imbalance (R=0.723-dominant side and R=0.705-non-dominant side). The anteroposterior stability index--measured as instability--showed correlations on the dominant (R=0.708) and non-dominant side (R=0.656). Lateral instability showed a correlation on the dominant side (R=0.721) and non-dominant side (R=0.728). The comparison of the balance indexes for dominant and non-dominant sides showed no statistically significant differences. CONCLUSION: High BMI demands more displacements to maintain postural balance.     

Differences in quadriceps muscle strength and fatigue between lean and obese subjects

The present study aimed to compare quadriceps femoris muscle strength and fatigue between obese (grade II and III) and nonobese adults. Ten obese (mean age: 25 years; mean BMI: 41 kg/m2) and ten lean (mean age: 27 years; mean BMI: 23 kg/m2) men were tested. Quadriceps muscle fatigue was quantified as the (percent) torque loss during a voluntary isokinetic (50 maximal contractions at 180°/s) and an electrostimulated (40 Hz) isometric protocol (5 min, 10% of the maximal torque). Maximal voluntary isometric and isokinetic torque and power were also measured. Voluntary torque loss was significantly higher (P < 0.05) in obese (−63.5%) than in lean subjects (−50.6%). Stimulated torque decreased significantly (P < 0.05) but equally in the two subject groups. Obese subjects displayed higher absolute (+20%; P < 0.01) but lower relative (i.e., normalized to body mass) (−32%; P < 0.001) muscle torque and power than their lean counterparts. Obese individuals demonstrated lower fatigue resistance during voluntary but not during stimulated knee extensions compared to their nonobese counterparts. Peripheral mechanisms of muscle fatigue—at least those associated to the present stimulated test—were not influenced by obesity. The observed quadriceps muscle function impairments (voluntary fatigue and relative strength) probably contribute to the reduced functional capacity of obese subjects during daily living activities.     

Body composition and endocrine status of long-term stress-induced binge-eating rats

Clinical binge eating runs a protracted course. The etiology of binge eating remains perplexing in part because, in humans, it is difficult to isolate and assess the independent and aggregate impact of various contributing variables. Using rats, we found that footshock stress and a history of caloric restriction (S+R), combine synergistically to induce binge eating. Stress and dieting are also strong antecedents and relapse factors in human eating disorders. Here we report further behavioral and physiological parallels to human binge eating. Like the protracted course of human binge eating, young female Sprague-Dawley rats continued to binge eat after 23 restriction/stress cycles (7 months) and this despite experiencing no significant weight loss during the restriction phases. Stress alone reduced adiposity by 35% (p<0.001) but S+R rats had no significant fat loss. An endocrine profile of normal plasma leptin and insulin levels but marked elevation of plasma corticosterone levels was found only in the binge-eating (S+R) rats (p<0.01), also paralleling endocrine profiles reported in clinical binge-eating studies. These behavioral and physiological similarities between this animal model and clinical binge eating increase its utility in understanding binge eating. Importantly, our findings also highlight the stubborn nature of binge eating: once a critical experience with dieting and stress is experienced, little if any further weight loss or food restriction is necessary to sustain it.