母鼠孕前营养过剩对子代小鼠生长发育影响

目的构建孕前营养过剩及超重小鼠模型,探讨孕前营养过剩对子代小鼠生长发育影响。方法 20只昆明种雌鼠随机分为对照组和实验组,分别给予标准饲料和高脂高糖饲料;两组单纯饲养4周后与雄鼠合笼,孕期继续上述饮食;产后均母乳喂养,产后3w断乳,哺乳期间母鼠仍按各自组别进食;监测单纯饲养期、孕期和哺乳期母鼠体重、血糖变化。两组子鼠断乳后一律以标准饲料喂养,监测子鼠出生至生后5w体重、身长和尾长发育。结果 1.母鼠体重和血糖变化：单纯饲养1周后开始实验组母鼠体重持续显著高于对照组（P〈0.05）;饲养1w和4w时,实验组母鼠血糖显著高于对照组（P〈0.05）。孕中、晚期实验组母鼠体重与对照组无显著差异（P〉0.05）。哺乳期两组母鼠体重、血糖均无显著差异（P〉0.05）。2.母乳喂养期子鼠发育：出生3天和7天,实验组子鼠体重显著高于对照组（P〈0.05）;整个母乳喂养期,实验组子鼠尾长显著长于对照组（P〈0.05）,两组子鼠身长无显著差异（P〉0.05）。3.自由采食期子鼠发育：整个自由采食期,实验组雌性子鼠体重显著高于对照组（P〈0.05）;出生35天,实验组雄性子鼠体重也显著高于对照组（P〈0.05）;整个自由采食期,实验组子鼠尾长均显著长于对照组（P〈0.05）,两组子鼠身长无显著差异（P〉0.05）。结论通过高脂高糖饲料可以建立孕前营养过剩及超重小鼠模型,母鼠孕前营养过剩导致子代小鼠出生体重增加以及成年早期肥胖,其对机体的深入影响及机制值得进一步研究。     

2018年襄阳市0～5岁儿童营养状况分析

目的分析2018年襄阳市5岁以下儿童营养现状,为制定儿童营养相关政策措施提供科学依据。方法采用整群分层随机抽样法抽取襄阳1 669名5岁以下儿童,对其主要健康体检指标进行Z评分,并通过SPSS 20.0对营养不良和营养过剩情况进行描述分析。结果襄阳市5岁以下儿童低体重率为1.08%、生长迟缓率2.22%、超重率5.09%;其中男童低体重率高于女童(χ²=5.508,P=0.019),女童生长迟缓率高于男童(χ²=4.816,P=0.028);县区生长迟缓率和超重率均高于市区(χ²=26.162,P<0.001;χ²=4.374,P=0.036)。结论襄阳市5岁以下儿童营养不良与超重问题并存,应加强重点地区(县区)儿童营养异常状况的早期筛查、识别和评估;大力开展儿童营养健康教育,提高人群营养知识知晓率;联合疾控机构、医疗机构、托幼机构和家庭实施干预措施,帮助5岁以下儿童建立正确合理的饮食和生活习惯。     

Breast cancer in relation to overnutrition

Summary Overnutrition and obesity, mainly due to intake of excess animal fat, have been associated with an increased risk of breast cancer by virtue of: (1) fat serving as a vehicle for fat-soluble environmental carcinogens, (2) fat-derived cocarcinogenic fatty acids and sterols, (3) hypercholesterolemia and increased ovarian and adrenocortical steroid synthesis (estrogens, androgens, cortisol), (4) decreased conversion of estrone to the antiestrogenic 2-hydroxyestrone, (5) increased conversion of androstenedione to the carcinogenic estrone (estradiol), and (6) depression of the immune response. However, the relevance of each of these mechanisms on the risk of breast cancer, remains unclear, despite many epidemiological, endocrinological, and immunological studies in humans and laboratory animals. Thus at present, the cause-effect relationship between overnutrition and breast cancer is not clear, nor is the interplay between nutritional, hormonal, and environmental risk factors of breast cancer understood. It seems that progress regarding overnutrition and risk of breast cancer can be achieved only when the various interrelated factors are evaluated in prospective studies with improved methods.     

Early weight gain and behavioral responsivity as predictors of dietary obesity in rats

Variance in diet-induced weight gain was examined for possible relationships with variations in early weight gain and three tests of behavioral responsivity. Female Sprague-Dawley rats were reared in litters of 4, 8, or 20. When animals reached adulthood, each animal's acoustic startle reflex, tail-pinch feeding responses and activity in an open field containing a palatable food were assessed. After completing these behavioral tests, rats were exposed to either palatable foods or a control diet for 59 days, following which all subjects were maintained on the control diet for 66 days. Body weights, food intakes, and naso-anal lengths were measured. Preweaning body weight gain for all rats correlated positively with later diet-induced weight gain. Rats reared in litters of 4 or 20 both gained less weight after exposure to palatable foods than did rats reared in litters of 8. Diet-induced weight gain correlated positively with magnitude of acoustic startle reflex and with latency to eat in response to tail pinch. These results tentatively identify specific predictive factors which may be useful in future studies of dietary obesity.     

High calcium diet improves the liver oxidative stress and microsteatosis in adult obese rats that were overfed during lactation

Obesity is related to diabetes, higher oxidative stress and nonalcoholic fatty liver disease, and dietetic therapies, for instance calcium-rich diet, can improve these dysfunctions. Rats raised in small litters (SL) had increased fat depots and insulin resistance at adulthood associated with higher liver oxidative stress and microsteatosis. Thus, we evaluated if dietary calcium can improve these changes. In PN3, litter size was adjusted to 3 pups (SL group) to induce overfeeding, while controls had 10 pups until weaning. At PN120, SL group was randomly divided into: rats fed with standard chow or fed with calcium supplementation (SL–Ca group, 10 g/kg chow) for 60 days. At PN180, dietary calcium normalized food consumption, visceral fat, plasma aspartate aminotransferase (AST) and glycaemia. Concerning oxidative balance, calcium restored both higher hepatic lipid peroxidation and protein carbonylation as well as higher plasma lipid peroxidation. Higher fatty acid synthase (FAS) content, steatosis and lower protein kinase B (Akt) in SL group were normalized by dietary calcium and SL–Ca rats had lower hepatic cholesterol. Thus, calcium supplementation improved the insulin sensitivity, redox balance and steatosis in the liver. Therefore, dietary calcium can be a promising therapy for liver disease in the metabolic syndrome.     

宫内营养对胎儿心血管健康的远期影响

宫内生长发育是复杂的动态过程,这一过程受到胎儿本身遗传因素的控制和影响,只有当母亲营养充足,胎盘功能良好足以维持胎儿的高效增殖、生长和分化时,胎儿才能依其生长轨迹生长发育。能量和（或）蛋白质的摄入情况对胎儿发育起着重要的决定作用。宫内营养不均衡包括营养不足和营养过剩。越来越多的证据表明宫内营养不均衡对胎儿远期的心血管健康造成了负面影响。宫内营养不均衡直接影响子代的血管结构及功能并增加子代心血管代谢异常的危险,从而影响子代的血管健康。母体营养不良可能导致胎儿生长受限;同样,母体的代谢性疾病,如胰岛素抵抗、糖尿病、高血压、血脂异常也会增加子代发生动脉粥样硬化和心血管疾病的风险。