蒙族男生青春期性发育与体成分关系探讨

本文调查了155名8～15岁牧区蒙族男生性发育、皮褶厚度及部分年龄段唾液睾酮水平．并以右肱三头肌及右肩胛下角皮褶厚度推算了体成分。分析结果表明：随性发育水平升高，瘦体重增加明显．总体脂呈缓慢上升．而体脂比则有下降趋势，提示蒙族男生育着期性发育与体成分的变化有一定联系。     

Mitochondrial COI sequences in mites: evidence for variations in base composition

Studies of mitochondrial DNA sequences in a variety of animals have shown important differences between phyla, including differences in the genetic codes used, and varying constraints on base composition. In that respect, little is known of mites, an important and diversified group. We sequenced a portion (340 nt) of the cytochrome oxidase subunit I (COI) encoding gene in twenty species of phytophagous mites belonging to nine genera of the two families Tetranychidae and Tenuipalpidae. The mitochondrial genetic code used in mites appeared to be the same as in insects. As is generally also the case in insects, the mite sequences were very rich in A + T (75% on average), especially at the third codon position (94%). However, important variations of base composition were observed among mite species, one of them showing as little as 69% A + T. Variations of base composition occur mostly through synonymous transitions, and do not have detectable effects on polypeptide evolution in this group.     

Study on Amino Acid Composition of HSP70 and the Level of Plasma Free Amino Acids of Workers with Long-term Exposure to Harmful factors

In order to know the practical value of heat stress protein 70 (HSP70) and to know the changes of plasma free amino acids of workers with the induction of HSP70 by harmful factors, the amino acid composition of major HSP, HSP70 purified from the heated cultured human leukemia cancer cell line K562, rabbit liver, rat liver and heart, and mouse liver with two-step procedures of DE52-cellulose ion exchange chromatography and affinity chromatography on ATP-agarose was examined. The level of plasma free amino acids of workers with long-term exposure to heat, carbon monoxide and the combined effect of both heat and car bon monoxide was also investigated. The results showed that the three richest amino acids in HSP70 of all origins were Gly, Glu and Asp, except that of rat heart which was rich in Gly, Phe and Glu. Additionally, Lys, Val, Leu and Ala were also found very rich in HSP70 of all origins. Compared with controls, the most of plasma free amino acids tended to increase and free methionine and tryptophan     

Assessment of total body water in paediatric patients on dialysis

BACKGROUND: Various anthropometric techniques are used to assess total bodywater in children on dialysis; however, their predictive accuracyand precision has not been validated. METHODS: We compared total body water measurements obtained by deuteriumoxide (D₂O) dilution with predictions of total body water from(1) height and weight, (2) skinfold measurements, and (3) bioelectricalimpedance analysis, using previously published formulae forhealthy children. Measurements were performed in 14 patientson peritoneal and in nine patients on haemodialysis, aged 4–22years. RESULTS: In the total population of dialysed patients, weight was thestrongest single predictor of total body water (R²=0.93) followedby the resistance index (RI=height²/impedance; R²=0.85) andheight (R²=0.93). A prediction formula based on height and weightpredicted total body water with a residual mean square error(RMSE) of 1.97 l (coefficient of variation (CV)=10.0%) and witha systematic overestimation of true total body water by 0.4%.A prediction equation based on skinfold measurements yieldeda total body water estimate with an RMSE of 2.15 1 (CV=10.5%)and overpredicted true total body water by an average of 2.2%.Using three published prediction equations incorporating RI,RMSEs of 2.78 1 (CV=14.1%) with a mean under- or overestimationof true total body water by 6.9, 7.1, and 0.8% respectively,were achieved. The prediction of total body water was optimizedby linear combinations of RI or the log-transformed sum of fourskinfolds (logsum) with weight by the following equations: total body water (1) = 9.97–3.13xlogsum +0.59xweight (kg) (1) (R² = 0.951; RMSE=1.67 1; CV = 8.17%). total body water (1) = 1.99 + 0.144 x RI (Ohm/cm²) + 0.40 x weight (kg) (2) (R² = 0.949; RMSE = 1.671; CV = 8.53%). The fit of these prediction formulae, which were derived fromthe total population, did not differ significantly between haemo-and peritoneal dialysis patients or between boys and girls. CONCLUSIONS: Both skinfold measurements and bioelectrical impedance analysiscan be used to improve the height- and weight- based predictionof total body water in children on dialysis.     

高锌摄入对正常小鼠生长发育、血液成份及免疫功能的影响

观察了高锌摄入对小鼠食量、体重、血液成份及免疫功能的影响，结果显示，连续给予高锌饲料（１．５ｇ／ｋｇ）３周后，可使小鼠食欲下降，体重增长延缓，饲料效价显著降低，血红蛋白和血钙含量明显减少，可明显增加血小板数量，升高血中胆固醇含量，并可导致脾肿大，抑制细胞吞噬功能，提示高锌对机体的危害。     

Effect of a Moderately Energy- and Salt-reduced Diet on Body Compartments and Blood Pressure Control in Obese Men with Mild Hypertension

Abstract Ten middle-aged moderately obese men with untreated mild hypertension were studied during a 6-week weight maintenance period and a 9-week period on a diet containing 5 MJ when body mass decreased by 8.4 kg (SE 1.4). According to urinary sodium excretion there was a mean reduction of 89 mmol/day (SE 16) in sodium intake. Mean arterial pressure fell by 2.5 to 14.1 mmHg (95% confidence interval) which was correlated to the reduction of body mass. The sympathetic nervous activity diminished with decreasing noradrenaline excretion and heart rate. There were no changes in the renin-aldosterone system. Estimation of the body composition with a four-compartment model utilizing determinations of body mass, total body potassium and total body water (TBW) showed reductions of body fat (8.4 kg (SE 1.4)) and body cell mass (BCM) (2.4 kg (SE 0.6)), but not of TBW. Extracellular water (ECW) increased significantly as judged from ECW/BCM calculations. Plasma volume was determined by Evan's blue and did not change significantly. We suggest that the observed changes in body composition represent one aspect of the adjustment to a weight reducing diet, while blood pressure is lowered by another mechanism in the adaptive response to dieting, i.e. reduction in sympathetic nervous activity.     

Fatty Acid Composition of Adipose Cells in Red and Yellow Marrow: A Possible Determinant of Haematopoietic Potential

The fatty acid composition of whole bone marrow and that of isolated, disaggregated adipose cells from red and yellow marrow was examined by gas chromatography. Consistent and significant shifts from myristic and palmatic acids (in red marrow) to their respective monounsaturated derivatives myristoleic and palmitoleic acids (in yellow marrow) were found. These differences in the fatty acids correlate with histochemical studies and lend further support to the concept that the composition of lipid in the adipose cells of bone marrow may determine their relative stability in relation to haematopoietic requirements.     

A qualitative study of work and work return in cancer survivors

Few studies have examined the impact of cancer on the survivor's quality of work life. The purpose of this qualitative study is to describe the work experiences among a diverse group of cancer survivors and to explore factors influencing decisions about work after cancer diagnosis and treatment. We interviewed 28 participants with a broad range of socioeconomic backgrounds and primary cancer sites. Qualitative results indicate that after learning about their cancer diagnosis, participants had diverse and complex patterns of work return and work change, and experienced a variety of factors that influenced post-cancer decisions. Experiences at work after cancer also varied in relation to how others responded, changes in productivity, effects of cancer and treatment on work, and feelings about work. Most respondents received little guidance from their physicians about work, and many participants described their cancer as impacting their priority of work relative to other aspects of their lives. Our findings reinforce the complexity of measuring employment outcomes and the range of adaptations made to improve the quality of work life. Additional research is needed to identify prognostic factors that can guide clinical or workplace efforts to restore cancer survivors to their desired level of work function and economic productivity.     

The subunit composition and pharmacology of alpha-Conotoxin MII-binding nicotinic acetylcholine receptors studied by a novel membrane-binding assay

The subunit composition and pharmacology of alpha-Conotoxin MII-binding (alpha-CtxMII) nicotinic acetylcholine receptors (nAChR) was studied by an improved [(125)I]-alpha-CtxMII membrane binding method. This binding method facilitates pharmacological studies that have been difficult to accomplish with [(125)I]-alpha-CtxMII autoradiography or alpha-CtxMII inhibition of [(125)I]-epibatidine binding. Binding densities and K(d)-values obtained by this [(125)I]-alpha-CtxMII membrane binding were similar to the values obtained by autoradiography or alpha-CtxMII inhibition of [(125)I]-epibatidine binding, verifying that each of these approaches measures the same nAChR population. Binding results with nAChR subunit-null mutant mice confirm and extend observations from earlier studies: [(125)I]-alpha-CtxMII binding measures two sets of alpha6beta2* nAChR (alpha4alpha6beta2beta3 or alpha6beta2beta3). Most nicotinic agonists and antagonists show monophasic inhibition of [(125)I]-alpha-CtxMII binding, indicating that alpha4alpha6beta2beta3 and alpha6beta2beta3 have similar binding properties. Comparison of the binding and activation profiles of alpha6beta2* nAChR to those of other nAChR subtypes (alpha4beta2* and beta4*) indicates that these receptors have distinctly different pharmacology indicating that it may be possible to target alpha6beta2* nAChR selectively to develop compounds that might be therapeutically useful.     

Healthy eating, activity and obesity prevention: a qualitative study of parent and child perceptions in Australia

Preventative health strategies incorporating the views of target participants have improved the likelihood of success. This qualitative study aimed to elicit child and parent views regarding social and environmental barriers to healthy eating, physical activity and child obesity prevention programmes, acceptable foci, and appropriate modes of delivery. To obtain views across a range of social circumstances three demographically diverse primary schools in Victoria, Australia were selected. Children in Grades 2 (aged 7-8 years) and 5 (aged 10-11 years) participated in focus groups of three to six children. Groups were semi-structured using photo-based activities to initiate discussion. Focus groups with established parent groups were also conducted. Comments were recorded, collated, and themes extracted using grounded theory. 119 children and 17 parents participated. Nine themes emerged: information and awareness, contradiction between knowledge and behaviour, lifestyle balance, local environment, barriers to a healthy lifestyle, contradictory messages, myths, roles of the school and family, and timing and content of prevention strategies for childhood obesity. In conclusion, awareness of food 'healthiness' was high however perceptions of the 'healthiness' of some sedentary activities that are otherwise of benefit (e.g. reading) were uncertain. The contradictions in messages children receive were reported to be a barrier to a healthy lifestyle. Parent recommendations regarding the timing and content of childhood obesity prevention strategies were consistent with quantitative research. Contradictions in the explicit and implicit messages children receive around diet and physical activity need to be prevented. Consistent promotion of healthy food and activity choices across settings is core to population prevention programmes for childhood obesity.