哺乳期过度喂养对子代小鼠成年早期脏器形态影响

目的 探讨哺乳期过度喂养对子代小鼠器官发育影响,为深入研究哺乳期过度喂养对远期健康和疾病的影响提供科学依据。方法 20只昆明种孕鼠随机分为对照组和实验组,孕期条件相同,产后母乳喂养,产后3 d调整每窝子鼠数为实验组4只,对照组10～12只;3周断乳,其后两组子鼠均以标准饲料喂养。监测子鼠体格发育情况,生后6周测定子鼠心、肝、胰、脾、肾和脑脏器系数,并检测各器官组织形态。结果 1)体格发育:生后3周和6周,实验组子鼠体重显著大于对照组(P<0.05);2)脏器系数:生后6周,实验组子鼠心、肝、脾脏器系数显著高于对照组(P<0.05);3)组织形态:与对照组子鼠比较,实验组子鼠心脏房、室壁厚度增加,心肌纤维横截面积增大,心肌纤维厚度增宽;肝细胞呈轻度水肿表现;脾脏红、白髓以及边缘区结构不清,白髓发育不良。结论 哺乳期过度喂养可导致子代生后近、远期肥胖,对某些器官造成形态学影响,后者可能是生命早期过度喂养影响生后远期健康的解剖学基础,其机制值得深入研究。     

金属硫蛋白与铅致子代鼠肝组织氧化损伤的关系

目的　应用金属硫蛋白 (MT)基因敲除小鼠及野生型小鼠模型 ,探讨孕期铅暴露 ,新生子代鼠肝组织氧化损伤与MT间的关系。方法　采用整体动物实验 ,于金属硫蛋白基因敲除小鼠 [MT( -/ -) ]和野生型小鼠 [MT( +/ +) ]孕第 0天至妊娠结束进行醋酸铅灌胃染毒 ,染毒剂量分别为 0、10、3 0、90mg/kg(对照、低、中、高剂量组 ) ,子鼠出生后第 1天处死 ,取肝组织测定丙二醛 (MDA)、还原型谷胱甘肽 (GSH)含量及超氧化物歧化酶 (SOD)活性 ,同时测定肝组织中MT的含量及母鼠血铅含量。结果　宫内铅暴露使MT( +/ +)及MT( -/ -)新生子鼠肝组织MDA升高 ,SOD活性降低 ,与染铅剂量组间存在显著的剂量 效应关系 (P <0 0 1)。相同铅染毒剂量组间比较结果显示 ,对照组、低及中剂量染铅组MT( -/ -)子鼠肝组织MDA含量显著高于MT( +/ +)子鼠 ,差异具有显著性 (P <0 0 1)。随染铅剂量的增加 ,MT( +/ +)子鼠肝组织GSH含量单向性升高 ;而MT( -/ -)子鼠肝组织GSH含量的变化为非单向性 ,表现为低、中剂量升高 ,高剂量时下降的趋势。低及高剂量染铅组MT( +/ +)子鼠肝组织MT含量显著高于对照组 (P <0 0 1)。相同染铅剂量MT( -/ -)母鼠血铅水平显著高于MT( +/ +)母鼠 (P <0 0 1)。结论　MT的缺乏可使经孕期铅暴露的新生子鼠肝组织脂     

孕期和哺乳期PM2.5气管暴露对子代小鼠主要脏器发育的影响及槲皮素的干预效果研究

目的探讨孕期和哺乳期PM2.5气管暴露对子代小鼠主要脏器发育的影响及槲皮素的干预效果。方法将北京大学医学部实验动物科学部提供健康成年SPF级ICR孕鼠60只随机分为空白对照组、PM2.5模型对照组和低、中、高三个槲皮素干预组,每组12只。于孕3、6、9、12、15天和产后2、5、8、11、14、17天分别进行气管滴注,除空白对照组外,其余各组均滴注PM2.5溶液(15 mg/kg),空白组给予相应剂量的干净滤膜洗脱液;各组孕鼠于孕期和哺乳期每天灌胃,空白对照组和PM2.5模型组给予0.15%羧甲基纤维素钠灌胃,槲皮素三个干预组分别予以50 mg/kg、100 mg/kg、200 mg/kg的槲皮素羧甲基纤维素钠混悬液灌胃。所有孕鼠自然生产,并记录生产仔鼠只数及性别。于产后3天调窝至每窝6只仔鼠,雌雄各半,于产后21天处死母鼠,并于生后3天、10天、21天、5周每窝仔鼠分别处死一雌一雄,摘取脏器(心、肝、脾、肺、肾)并称重,并计算脏器系数,同时测量肠道长度。结果四个时间点仔鼠的脏器重量和系数模型组和空白组之间差异有统计学意义,尤其表现为心、脾、肾,而槲皮素低、中剂量组与PM2.5模型组相比表现出一定的干预作用。PM2.5模型组仔鼠生后10天、21天及5周的小肠长度显著小于空白对照组(P0.05)。结论孕期及哺乳期PM2.5气管暴露对子代小鼠的心、脾、肾重量和脏器系数产生影响,并且使得子代小鼠小肠长度变短。孕期和哺乳期进行50 mg/kg和100 mg/kg的槲皮素干预可以在一定程度上减少PM2.5的上述发育损害。     

孕期和哺乳期双酚A暴露对母鼠体内糖代谢及瘦素水平的影响

目的研究孕期和哺乳期暴露双酚A(bispheno1 A,BPA)对母鼠体内糖代谢及血清瘦素水平的影响。方法将18只妊娠的健康清洁级SD雌性大鼠随机分为3组,分别为对照组(含1%乙醇溶液)和低剂量(1 mg/L)、高剂量(10mg/L)BPA染毒组,每组6只。从妊娠第6天至哺乳期[哺乳(lactation day,LD)21 d]结束,采用自由饮水方式进行染毒。测定母鼠空腹时血糖及血清胰岛素、瘦素水平,并计算胰岛素抵抗指数。结果与对照组比较,断乳后各剂量BPA染毒组母鼠空腹时血糖、胰岛素和瘦素水平及胰岛素抵抗指数均显著增高,差异有统计学意义(P<0.05,P<0.01);与低剂量BPA染毒组比较,高剂量BPA染毒组母鼠血清胰岛素水平和胰岛素抵抗指数均明显增高,差异有统计学意义(P<0.05)。且随着BPA染毒浓度的升高,母鼠空腹时血糖及血清胰岛素、瘦素水平和胰岛素抵抗指数均呈上升趋势。结论孕期和哺乳期暴露BPA可引起母鼠胰岛素抵抗,这可能与血清瘦素水平升高有关。     

壬基酚对断乳期子代雄性SD大鼠生殖系统发育的影响

[目的]研究壬基酚(NP)对断乳期子代雄性SD大鼠生殖系统发育的影响。[方法]对母鼠孕期d7直至产后断乳期染毒NP(0,50,100,200mg/kg),每组10只母鼠。断乳期处死母鼠,同时每个剂量组处死F1雄性子代大鼠10只,两者均股动脉取血,测定血清催乳素(PRL)、黄体生成激素(LH)、卵泡刺激素(FSH)水平和血清NP浓度,检查F1雄性子代脏器系数,并对F1雄性子代睾丸进行组织病理学分析。[结果]50mg/kg,100mg/kgNP组母鼠催乳素(PRL)低于对照组,差异有统计学意义(P﹤0.05)。100mg/kg,200mg/kgNP组的血清NP浓度高于对照组,差异有统计学意义(P﹤0.05)。F1子代大鼠断乳期血清壬基酚浓度,100、200mg/kgNP剂量组高于对照组,差异有统计学意义(P﹤0.05),而体重低于对照组,差异有统计学意义(P﹤0.05)。组织病理学观察可见200mg/kg壬基酚组睾丸生精小管与对照组相比显著缩小,差异有统计学意义(P﹤0.05)。[结论]母鼠孕期和哺乳期染毒壬基酚能够影响断乳期子代雄性SD大鼠生殖系统的正常发育。     

邻苯二甲酸丁苄酯对仔代大鼠发育的影响

目的探讨邻苯二甲酸丁苄酯(butyl benzyl phthalate,BBP)暴露对仔代大鼠发育的影响。方法将80只4周龄Wistar雌性大鼠按体重随机分为4组,每组20只,分别喂饲BBP含量为0、0.05%、0.25%和0.75%(分别相当于每日50、250和750 mg/kg体重)的饲料,从4周龄持续到其仔鼠出生后第21天(postnatal day 21,PND21)断乳结束(包括雌性大鼠交配期、孕期及哺乳期);仔鼠断乳前与母鼠同笼饲养,断乳后至PND49,仔鼠按性别分笼饲养,喂饲方式和染毒剂量与其亲代母鼠相同。观察母鼠的一般情况,记录其妊娠时间、产仔数,计算分娩率、仔鼠性别比等;测定不同日龄仔鼠的体重以及脑、心、肝、脾、肺、肾、睾丸(或子宫、卵巢)重量,并计算脏器系数;测定仔鼠血清相关生化指标水平。结果与对照组比较,250 mg/kg组雌雄仔鼠脾脏系数升高(P0.05),750 mg/kg组雌雄仔鼠肝脏系数升高(P0.01),雄性仔鼠睾丸系数升高(P0.05);各剂量BBP染毒组母鼠的分娩率、妊娠时间、产仔数、仔鼠性别比无明显变化;250、750 mg/kg组雄性仔鼠血清丙氨酸氨基转移酶(ALT)活力均明显升高;各剂量染毒组血清总胆红素(TBIL)含量均下降;750 mg/kg组血清总胆固醇(CHO)含量和碱性磷酸酶(ALP)、胆碱酯酶(CHE)活力均升高;雌性大鼠仅血清TBIL含量下降(P0.05);其他指标未见异常。结论 BBP暴露影响仔鼠的肝脏、脾脏及睾丸发育,BBP致雄性仔鼠肝功能损伤较雌性仔鼠严重。     

出生前接触酒精对大鼠小脑中BDNF和TrkB的影响

[目的]研究出生前接触酒精对出生后大鼠小脑中脑源性神经营养因子(BDNF)及其受体酪氨酸激酶B(TrkB)的影响。[方法]选择SD母鼠24只,怀孕d6时随机法分为酒精组、正常组和代理母组。酒精组(n=6)每日摄取35卡的酒精;正常组(n=6)每日摄取与酒精组相同热卡的奶粉;代理母组(n=12)每日摄取正常的鼠食。酒精组、正常组母鼠分娩6h后,与其子分开,麻醉后心脏采血,测试血液中乙醇浓度和甲状腺素量,并作统计学分析。酒精组、正常组新生子鼠由代理母组的代理母鼠养育,并分别于生后0,7,14,21,28d(P0、P7、P14、P21、P28)时麻醉处死,采用免疫组织化学染色法,在小脑颗粒层中观察BDNF及TrkB阳性浦肯野细胞(PurkinjeCell,Pc)的分布及形态。[结果]①酒精组母鼠血液中酒精浓度明显高于正常组(P﹤0.05),而酒精组母鼠血液中甲状腺素含量明显低于正常组(P﹤0.05)。②正常组子鼠小脑中P14开始出现基本单层排列的成熟的BDNF及TrkB阳性浦肯野细胞,但酒精组子鼠小脑中始终未出现完全单层排列的成熟的BDNF及TrkB阳性浦肯野细胞,且P28时出现BDNF及TrkB阳性浦肯野细胞的明显减少。[结论]母鼠孕期摄取酒精时,引起其血液中甲状腺素含量减少,并可抑制其后代小脑中BDNF及TrkB阳性浦肯野细胞的发育。     

母鼠妊娠及哺乳期铅摄入致后代学习记忆损害动物模型的建立

目的建立妊娠及哺乳期铅摄入对后代学习记忆损害的动物模型的影响。方法母鼠在妊娠及哺乳期的不同阶段给予铅暴露后观察子鼠的学习记忆能力的变化,孕鼠70只,自确定受孕后即随机分成7组。孕早期低剂量组(60mg/kg)和孕早期高剂量组(240mg/kg),于受孕第0天给醋酸铅直至仔鼠断乳,其染铅42d;孕晚期低剂量组(60mg/kg)和孕晚期高剂量组(240mg/kg),于受孕第14天起给醋酸铅至仔鼠断乳,共染铅28d;出生后低剂量组(60mg/kg)和高剂量组(240mg/kg),于分娩日起给醋酸铅至仔鼠断乳,共染铅21d;另设阴性对照组。结果大鼠在孕期和哺乳期给铅致20日龄后代幼鼠的定位航行能力受到明显影响。随着训练时间的增加,对照组的幼鼠逃避时间显著缩短,而在孕期和哺乳期给铅致20日龄各组后代幼鼠的逃避时间并没有显著缩短,与对照组比较,差异具有统计学意义。在训练7d后进行空间探索测试,对照组幼鼠搜寻平台的时间明显较实验各组快,差异具有统计学意义;穿越平台的次数对照组也显著多于实验各组,差异有统计学意义;在第Ⅰ象限停留的时间比实验各组要长,差异有统计学意义。结论母鼠妊娠及哺乳期铅处理的各组幼鼠空间学习记忆能力有明显的影响,此模型适合进一步研究围产期铅暴露后子代学习记忆的影响。     

弓形虫感染孕鼠出生子鼠的发育研究

[目的]观察孕鼠感染弓形虫后出生子鼠的身体、智力发育、寿命.[方法]以1×103个/ml和2×103个/ml RH株弓形虫0.1ml腹腔感染孕中期鼠(d 10),获得分娩子鼠.根据母鼠感染剂量不同,将子鼠分为重度感染组、轻度感染组和非感染组,根据子鼠出生时IgM或CAg是否阳性,分为感染阳性组、感染阴性和非感染组,记录子鼠体重、智力发育、寿命情况.[结果]重度感染组比轻度感染组、感染阳性组比感染阴性组子鼠体重轻、智力低、寿命短.感染阳性组与非感染组比较,智力低、寿命无差别.[结论]孕期感染弓形虫可使存活子代体重减轻、智力降低、寿命缩短,其严重程度与感染剂量大小有关.     

母鼠孕期低铁干预对子代成年大鼠细胞因子水平的影响

目的:通过建立大鼠孕期营养性铁缺乏模型,探讨母鼠孕期低铁干预对其子鼠TNF-α,IL-6,EPO的影响。方法:将6周龄健康Wistar雌性大鼠随机分为二组,实验组喂低铁饲料,对照组喂富铁饲料。4周后与健康成年Wistar雄鼠同笼交配,低铁干预持续至哺乳期结束,随后二组大鼠均转入铁平衡期,持续7周。将实验组和对照组各自再分为两小实验组,每小实验组再经低铁干预。持续14周后宰杀大鼠,检测仔鼠血浆中TNF-α,IL-6,EPO的水平。结果:低铁干预组子代大鼠体重在断乳以后及转入平衡期饲喂富铁饲料后比对照组增长显著,呈现追赶生长;母鼠孕期低铁干预,其子鼠成年后再次铁干预,实验组血浆中TNF-α,EPO和IL-6均高于对照组(P<0.05)。结论:母鼠孕期低铁干预,其子鼠的体重在断乳后及补铁后生长迅速并显著超过对照组;铁缺乏可改变体内细胞因子的水平;生命早期低铁干预可产生更大的影响,并由此可能影响由该细胞因子介导的免疫反应。     

Risk,Efficacy, and Seeking of General,Breast, and Prostate Cancer Information

The authors investigated the independent and interactive effects of perceived risk and perceived efficacy on seeking of general, breast, and prostate cancer information. Analysis of the 2003 Health Information National Trend Survey indicates that perceived absolute risk and perceived response efficacy have generally independent—rather than interactive—effects on cancer information seeking. The influence of perceived absolute risk on prostate cancer information seeking appears to be moderated by perceived relative risk. When perceived relative risk is low, perceived absolute risk has no effect on prostate cancer information seeking; when perceived relative risk is high, perceived absolute risk exerts a significant positive influence on prostate cancer information seeking. The authors discuss the theoretical and practical implications.     

Risk, efficacy, and seeking of general, breast, and prostate cancer information

The authors investigated the independent and interactive effects of perceived risk and perceived efficacy on seeking of general, breast, and prostate cancer information. Analysis of the 2003 Health Information National Trend Survey indicates that perceived absolute risk and perceived response efficacy have generally independent-rather than interactive-effects on cancer information seeking. The influence of perceived absolute risk on prostate cancer information seeking appears to be moderated by perceived relative risk. When perceived relative risk is low, perceived absolute risk has no effect on prostate cancer information seeking; when perceived relative risk is high, perceived absolute risk exerts a significant positive influence on prostate cancer information seeking. The authors discuss the theoretical and practical implications.     

Bioaccumulation,metabolism, and effects of DDT,fenitrothion, and chlorpyrifos onSaccharomyces cerevisiae

Saccharomyces cerevisiae accumulated DDT, fenitrothion, and chlorpyrifos rapidly from yeast glucose medium. The maximum concentrations of DDT, fenitrothion, and chlorpyrifos accumulated were 8,253, 18,960 and 11,579 g/g (dry wt), respectively. The pattern of accumulation was similar for all insecticides. The bioconcentration factor was inversely proportional to insecticide solubilities.Saccharomyces metabolized the three insecticides, but only two metabolites of DDT (DDD and DDE) were identified. Protoplast cultures were more sensitive to DDT and fenitrothion compared to normal cultures but were less sensitive to chlorpyrifos. Both the normal and protoplast cultures recovered from the toxic effect after 24 hr.     

Water,sanitation, and hygiene in schools: Status and implications of low coverage in Ethiopia,Kenya, Mozambique,Rwanda, Uganda,and Zambia

Adequate access to water, sanitation, and hygiene (WaSH) in schools impacts health, educational outcomes, and gender disparities. Little multi-country research has been published on WaSH in rural schools in Sub-Saharan Africa. In this multi-national cross-sectional WaSH study, we document WaSH access, continuity, quality, quantity, and reliability in 2270 schools that were randomly sampled in rural regions of six Sub-Saharan African countries: Ethiopia, Kenya, Mozambique, Rwanda, Uganda, and Zambia. Data collection included: school WaSH surveys containing internationally established WaSH indicators, direct observation, and field- and laboratory-based microbiological water quality testing. We found 1% of rural schools in Ethiopia and Mozambique to 23% of rural schools in Rwanda had improved water sources on premises, improved sanitation, and water and soap for handwashing. Fewer than 23% of rural schools in the six countries studied met the World Health Organization’s recommended student-to-latrine ratios for boys and for girls. Fewer than 20% were observed to have at least four of five recommended menstrual hygiene services (separate-sex latrines with doors and locks, water for use, waste bin). The low access to safe and adequate WaSH services in rural schools suggest opportunities for WaSH interventions that could have substantive impact on health, education, and gender disparities.     

Analysis of protein amino acids,non-protein amino acids and metabolites,dietary protein,glucose, fructose,sucrose, phenolic,and flavonoid content and antioxidative properties of potato tubers,peels, and cortexes (pulps)

The composition and antioxidative activity of whole potato tubers from five Korean cultivars, three peels from one cultivar, and eight pulps (cortexes) after peeling from six different cultivars were evaluated. Whole tubers were sectioned into three parts followed by analysis of the peels and pulps of each part. The following characteristics were determined: the dimensions and water content of whole tubers; nutritional protein content consisting of protein and free amino acids by an automated Kjeldahl nitrogen assay; free non-protein amino acids, metabolites, and fructose, glucose, and sucrose content by HPLC; phenolic compounds by HPLC and LC/MS; total phenolics and flavonoids by colorimetry; and antioxidative properties by ABTS, DPPH, and FRAP assays. The results demonstrate differences and similarities in the content of nutritional and bioactive compounds and in their bioactivities from whole potatoes, peels, and pulps. The present study reports for the first time the analysis of multiple potato nutrients and bioactive components as well the antioxidative properties of whole potatoes, peels, and pulps derived from the same tubers. The described methods are expected to facilitate the analysis of commercial and newly-developed potato cultivars, peels, and pulps and relate their composition and antioxidative activities to their reported nutritional, health-promoting, and industrial properties.     

The effect of lead and cadmium on liver,kidney, and brain levels of cadmium,copper, lead,manganese, and zinc,and on erythrocyte ALA-D activity in mice

Summary Lead and cadmium were administered intraperitoneally, singly and jointly, to the mice. The levels of cadmium, copper, manganese, lead and zinc were determined in liver, kidney and brain by atomic absorption spectrophotometric technique and deltaaminolevulinic acid dehydratase (ALA-D) activity was determined in erythrocytes. The tissue levels of some of these metals were found significantly altered by cadmium and lead both, but cadmium was found to have no effect on blood on ALA-D activity.     

Contributions of obesity, gender, hunger, food preference, and body size to bite size, bite speed, and rate of eating

College students ate two high preference or two low preference doughnuts under high or low hunger conditions. Subjects were led to believe that we were interested in preference ratings made after eating the doughnuts. The number of bites and the total snack time were covertly recorded. Having weighed the doughnuts previously, we calculated the bite size (amount per bite), bite speed (time per bite), and eating rate (amount per second). Eating rate increased as obesity, body size, hunger, and preference increased; men ate at a faster rate than women. Larger bites accounted for the increased rate of the obese, the high preference subjects, and those having a larger body size. The hungry subjects increased their eating rate by taking faster bites. Men ate faster than women by taking both larger but slower bites. Thus eating rate is under multiple control. The data also suggest that the effects of obesity and, in part, gender on these eating responses may be more parsimoniously explained as body size effects. Modification of these within-session eating responses in order to regulate food intake will be successful only when the relationships among these measures are understood.