丝瓜络对实验性高血脂大鼠的降血脂效应

目的:探讨中药丝瓜络(RLF)对实验性高血脂大鼠的降血脂效果,以及对实验大鼠体重的影响。方法:雄性SD大鼠32只,随机均分为4组:对照(A)组、高脂模型(B)组、高脂+丝瓜络(C)组、丝瓜络(D)组。 A组和D组大鼠每日饲基础饲料,B组和C组给予高胆固醇饲料,C组和D组的大鼠每日经胃灌服丝瓜络煎剂10 mL/kg BW,A组和B组为每日每只经胃灌服饮用水2 mL,实验周期为14 d。结果:(1)实验后B组大鼠的血清胆固醇(TC)和甘油三脂(TG)分别为(4.63±1.10)和(1.13±0.15) mmol/L,显著高于对照(A)组的TC 和 (P<0.01), 而C组的TC 和TG 则显著低于B组(分别为P<0.05及P<0.01);(2)D组大鼠的TC,实验后较给药前有显著降低(P<0.01);(3)在实验的第8d,B组大鼠的血清高密度脂蛋白胆固醇(HDL-C)为(0.61±0.11) mmol/L,显著低于A 组 (P<0.01),而C组HDL-C 与A组没有显著差异(P>0.05);(4)B组大鼠体重实验后显著增加,而 C组的体重在变化与A组相似。结论:丝瓜络对实验性高血脂大鼠有明显的降血脂效应,使实验大鼠的TC和TG显著降低,HDL-C显著升高,而且能显著减轻实验大鼠的体重。     

N-乙酰半胱氨酸对顺铂导致肾毒性的保护作用及作用机制分析

目的:通过动物实验分析探讨N-乙酰半胱氨酸对于顺铂诱导的肾毒性和肾损伤的保护功能及其机制,为临床药理研究提供参考。方法:选取60只BALB/c小鼠,雌雄各半,喂养7 d后腹腔注射20 mg/kg的顺铂,持续注射3 d诱导并建立急性肾损伤小鼠模型(AKI),后随机分为6组,A组给予5 mg/kg顺铂,B组给予250μg/(100 g·d)的N-乙酰半胱氨酸,C组给予5 mg/kg顺铂+250μg/(100 g·d)的N-乙酰半胱氨酸;D组给予500μg/(100 g·d)的N-乙酰半胱氨酸;E组给予5 mg/kg顺铂+500μg/(100 g·d)的N-乙酰半胱氨酸,F组注射生理盐水做对照,连续治疗7 d后,抽取小鼠眼球血,测定生化指标、炎症因子水平;做肾脏病理切片图评价肾损伤水平,并加以比较。结果:在给药前,6组小鼠的血肌酐(Scr)、尿素氮(BUN)、肾损伤评分(RIS)、肿瘤坏死因子α(TNF-α)、谷胱甘肽(GSH)水平比较差异无统计学意义(P0.05);给药后,6组上述指标差异有统计学意义(P0.05):①血清Scr、BUN、TNF-α和肾损伤评分RIS:A组F组C组E组B组D组,与治疗前相比,A组显著增加(P0.05);B组、D组、E组显著降低(P0.05),C组、F组差异无统计学意义(P0.05);②血清GSH:A组F组C组E组B组D组,与治疗前相比,A组显著降低(P0.05);B组、D组、E组显著增加(P0.05),C组、F组差异无统计学意义(P0.05)。结论:N-乙酰半胱氨酸可减轻因顺铂导致的小鼠肾毒性和肾损伤程度,对肾脏具有保护作用,且动物实验的疗效与N-乙酰半胱氨酸的剂量有高度相关性,其机制则与N-乙酰半胱氨酸具有抑制炎症反应和肾组织细胞凋亡、抗氧化应激等药理作用有关。     

富氢水和乳果糖对环磷酰胺处理小鼠的抗突变作用

目的 探讨饮用富氢水和产氢营养因子乳果糖的抗突变作用.方法 36只昆明小鼠按随机数字表分为6组,每组6只.空白对照组(A组)、富氢水处理组(B组)和乳果糖处理组(C组):这3组小鼠正常喂养3d后,第4～6天分别使用蒸馏水、富氢水、50％乳果糖灌胃(20 ml/kg、1次/d);抗生素对照组(D组)、抗生素+富氢水处理组(E组)和抗生素+乳果糖处理组(F组):这3组小鼠第1～3天随意饮用含抗生素的水,第4～6天分别使用蒸馏水、富氢水、50％乳果糖灌胃(20 ml/kg、1次/d).末次灌胃后小鼠腹腔注射环磷酰胺(0.04 g/kg),24 h后处死小鼠,进行骨髓细胞学检查,计算各组小鼠骨髓嗜多染红细胞微核率.结果 A、B、C、D、E、F组小鼠骨髓嗜多染红细胞微核率分别为(16.00±0.67)‰、(15.11±0.25)‰、(10.17±0.35)‰、(22.39±0.51)‰、(15.44±0.44)‰、(18.67±0.37)‰.与A组比较,C组微核率显著减少,D组微核率显著增加(均P＜0.01).与D组比较,E组和F组微核率显著减少(均P＜o.o1).与C组比较,F组微核率显著增加(P＜0.01).结论 富氢水和乳果糖均可拮抗环磷酰胺的致突变作用,抗生素预处理可以显著降低乳果糖的抗突变作用.     

富血小板纤维蛋白联合姜黄素纳米颗粒水凝胶促糖尿病小鼠创面愈合

背景:糖尿病难愈性创面目前仍缺乏十分理想的治疗手段,探索促进糖尿病创面愈合的方法意义重大。目的:观察富血小板纤维蛋白联合姜黄素纳米颗粒水凝胶对糖尿病小鼠创面愈合的影响。方法:分别制备富血小板纤维蛋白与姜黄素纳米颗粒水凝胶。从100只成年C57BL/6J小鼠中随机取20只作为正常对照(A组),另外80只建立糖尿病模型。在建模成功的72只小鼠背部制作直径1 cm的圆形全层皮肤损伤创面,随机分4组处理:B组涂抹生理盐水,C组涂抹富血小板纤维蛋白与游离姜黄素溶液,D组涂抹富血小板纤维蛋白与姜黄素纳米颗粒溶液,E组涂抹富血小板纤维蛋白与姜黄素纳米颗粒水凝胶,每组18只。A组小鼠背部制作直径1 cm的圆形全层皮肤损伤创面,涂抹生理盐水。于创面造模当日即开始给药,之后隔日分别给予上述对应药物,直至伤后12 d。处理后第3,9,12天,观察创面愈合及创缘组织病理组织学变化。结果与结论:(1)处理后第12天,A、C、D、E组创面基本愈合完全,B组创面未完全愈合,E组创面愈合率高于B、C、D组(P <0.05);(2)处理后第3天苏木精-伊红染色显示,E组创面愈合情况好于B、C、D组,炎细胞浸润及肉...     

高压氧对胎兔及新生子兔生长发育的影响

目的:探讨高压氧对妊娠期限以及胎兔、新生子兔生长发育的影响。方法:新西兰妊娠大白兔10只,随机分成实验组A(组)和对照组B(组),实验组接受高压氧治疗,对照组置于常压空气中,连续10天,母兔分娩后,随机选择新生子兔40只,根据母兔接受高压氧与否,按出生体重相近分别配对分为C、D组(即孕兔接受高压氧治疗A组之子兔)和E、F组(即孕兔常压空气对照B组之子兔)。其中C、E组从出生第二天接受HBO治疗,D、F组置于常压空气中。结果:1.A、B两组母兔妊娠期及新生子兔成活率无显著性差异(P>0.05)。2.A、B两组新生子兔平均出生体重无显性差异(P>0.05);C、E两组子兔第12天平均体重及摄乳量与D、F组相比明显增加,有显著性差异(P<0.01);D与F组第12天平均体重及摄乳量无明显显著性差异(P>0.05)。3.各组新生子兔均于第12天开眼。结论:1.高压氧对母兔孕龄无影响,不导致早产。2.小剂量高压氧对正常胎兔生长发育无影响。3.高压氧促进新生子兔生长发育。     

TLR2基因敲除下调高脂饮食诱导的肥胖小鼠脂肪组织炎症因子表达和细胞凋亡

目的研究Toll样受体2(TLR2)基因敲除对高脂饮食诱导的肥胖小鼠脂肪组织炎症因子表达和细胞凋亡的影响。方法雄性C57BL6小鼠和TLR2基因敲除小鼠分为:正常对照组、肥胖组、TLR2基因敲除组和TLR2基因敲除肥胖组,并给予普通饮食或高脂饮食喂养。16周后检测各组小鼠空腹血糖、甘油三酯、总胆固醇、低密度脂蛋白、高密度脂蛋白和游离脂肪酸水平。分光光度计法检测小鼠脂肪组织Caspase3活性,Western blot检测Bcl2、Bax、MyD88和p65NFκB蛋白相对表达量。荧光实时定量PCR检测小鼠脂肪组织IL-6和TNF-αmRNA相对表达量。结果与正常对照组相比,肥胖组小鼠空腹血糖、甘油三酯、总胆固醇、低密度脂蛋白、高密度脂蛋白水平降低和游离脂肪酸水平升高;脂肪组织Caspase3活性、Bax蛋白、MyD88蛋白、p65NFκB蛋白、IL-6 mRNA和TNF-αmRNA相对表达量升高,Bcl2蛋白相对表达量减少。与肥胖组相比,基因敲除肥胖组小鼠空腹血糖、甘油三酯、总胆固醇、低密度脂蛋白、高密度脂蛋白水平降低和游离脂肪酸水平降低;脂肪组织Bcl2蛋白相对表达量增加,Caspase3活性、Bax蛋白、MyD88蛋白、p65NFκB蛋蛋白、IL-6 mRNA和TNF-αmRNA相对表达量减少。结论 TLR2基因敲除下调了高脂饮食诱导的肥胖小鼠脂肪组织炎症因子的表达和细胞凋亡。     

不同出生体重儿的甲状腺功能检测及分析

目的探讨不同出生体重新生儿的甲状腺功能。方法将盐城市第三人民医院2003年2月~2006年12月收治的不同出生体重的新生儿120例分成4组:A组(出生体重1100g~1499g n1=30),B组(出生体重1500g~1999g n2=30),C组(出生体重2000g~2499g n3=30),D组(出生体重2500g~3750g n4=30),采用放免法测定不同出生体重新生儿出生后第1天及第10天血清FT3、FT4及TSH水平。结果各组血清FT3、FT4、TSH生后1~10天均成下降趋势,FT3、FT4的水平与出生体重成正相关,C组、D组生后第1,10天血清FT3、FT4明显高于A组、B组,B组明显高于A组,C组与D组之间差异无显著性;生后第1天TSH水平C组、D组>A组、B组,生后第10天血清TSH A组、B组>C组、D组,C组与D组之间差异无显著性。结论新生儿的甲状腺功能与出生体重成正相关,出生体重低于1999g的新生儿存在甲状腺功能的暂时性低下。     

丝瓜络对实验性高血脂大鼠的降血脂效应

目的 :探讨中药丝瓜络 (LuffacylindericaRoam)对实验性高血脂大鼠的降血脂效果 ,以及对实验大鼠体重的影响。方法 :雄性SD大鼠 32只 ,随机均分为 4组 :对照组 (A组 )组 ,丝瓜络组 (B组 ) ,高脂模型组 (C组 ) ,高脂 +丝瓜络组 (D组 ) ,A组和B组的大鼠每日饲基础饲料 ,C组和D组给予高胆固醇饲料 ,B和D组的大鼠每日经胃灌服丝瓜络煎剂 6 70g生药·L-1/只 ,A和C组为每日经胃灌服饮用水 2mL/只 ,实验周期为 14d。结果 :(1)实验后C组大鼠的血清胆固醇 (TC)和甘油三脂 (TG)分别为(4 33± 1 10 )和 (1 13± 0 15 )mmol/L ,显著高于对照…     

早期肠内营养治疗对极低出生体重儿近期预后及hGH、IGF-1的影响

目的 探讨早期肠内营养治疗对极低出生体重儿近期预后的临床影响.方法 将136例极低出生体重儿根据肠内营养开始治疗时间分为A组(≤3d,n =73)、B组(4～6d,n=41例)和C组(≥7d,n=22)三组,比较三组极低出生体重儿的生长速度、消化功能改善情况,并比较三组极低出生体重儿治疗前后生长激素(hGH)、胰岛素样生长因子-1(IGF-1)水平变化情况.结果 三组低出生体重儿消化道症状发生率及头围增长幅度、体重增长幅度比较差异无统计学意义(P＞0.05);第1周时A组奶量均高于B组、C组(P＜0.05),B组奶量高于C组(P＜0.05);第2、3周时A组、B组奶量均高于C组(P＜0.05);A组院内感染发生率低于C组(P＜0.05);第1周时,A组身长增长幅度高于B组和C组(P＜0.05),B组高于C组(P＜0.05);A组达全肠内营养时间低于B组和C组(P＜0.05),B组低于C组(P＜0.05);A组、B组住院时间均低于C组(P＜0.05);A组hGH、IGF-1水平均高于B组和C组,B组高于C组,差异有统计学意义(P＜0.05).结论 早期肠内营养治疗增加了极低出生体重儿喂奶量,缩短了达全肠内营养时间、中心静脉置管时间及住院时间,值得临床重视.     

毛囊保存技术在自体毛发移植中的作用机制及疗效的影响研究

目的研究不同毛囊保存技术对离体毛囊活性的影响,并对自体毛发移植中的毛囊活性进行评估和比较。方法将毛囊放置于0℃~4℃生理盐水(A组)、0℃~4℃醋酸平衡盐(B组)、0℃~4℃DMEM培养基(C组)、胰岛素加氢化可的松加DMEM培养基(D组)、D组加10%自体血清(E组)、E组加表皮生长因子(F组)各缓冲液6 h后,在培养箱中培养6 d。测量毛囊生长长度(hair shaft elongation,HSE),HE染色观察毛囊生长状态及自体移植后20周时行梳发实验测定疗效。结果 HSE结果表明,A、B、C组之间无显著差异,D、E、F组HSE明显高于A、B、C组;F组明显优于D、E组,差异具有统计学意义(P0.05)。A、B、C组毛囊的毛母质、外毛根鞘中凋亡细胞明显增多,F组中仅可见散在凋亡细胞,毛囊的生长状态最好。A+B+C组和D+E+F组的有效率分别为60.0%和86.67%,差异有统计学意义(P0.05)。结论 Williams E液作为毛囊存放的缓冲液,有利于保持毛囊的活性。     

Hypolipidemic effect of pantothenic acid derivatives in mice with hypothalamic obesity induced by aurothioglucose

The hypolipidemic effects of pantothenic acid derivatives (phosphopantothenate, panthenol and pantethine) were studied in mice with hypothalamic obesity. Hypothalamic obesity in mice was induced by single injection of aurothioglucose (300 mg/kg body wt, i.p.). All the tested substances were administered during the last 10 days before decapitation (i.m., of dosage equivalent to 150 mg/kg body wt of phosphopantothenate). The studied substances inhibited the weight gain of the animals with hypothalamic obesity over the last 10 days of the experiment. The treatment with aurothioglucose increased food intake and mean body weight, blood glucose level; insulin, serum total cholesterol, triglyceride, the sum of LDL + VLDL and LDL-cholesterol concentration; triglyceride and cholesterol fractions in the liver; triglyceride and FFA content as well as lipoprotein lipase activity in adipose tissue of experimental mice. The administration of the assay compounds lowered food intake and mean body weight, insulin and glucose levels and decreased the content of triglycerides, total cholesterol and cholesterol esters in serum and adipose tissue as well as raised the activity of lipoprotein lipase in adipose tissue and serum lipolytic activity in obese mice. Among the compounds studied the reverse effect of panthenol was especially pronounced. The mechanism of hypolipidemic effects of pantothenic acid derivatives can be related to the reduced resistance to insulin and activation of lipolysis in serum and adipose tissue.     

枸骨叶水提物对小鼠肥胖的预防作用及对脂肪分化的影响

目的:研究枸骨叶水提物(ICAE)对高脂饮食(HFD)小鼠肥胖的预防作用及对脂肪分化的影响.方法:本研究采用HFD诱导小鼠肥胖,同时灌胃给予ICAE,以奥利司他(orlistat)为阳性对照药。39只昆明雄性小鼠分成4组,包括对照组(n=10)、肥胖模型组(n=9)、orlistat治疗组(n=10)和ICAE治疗组(n=10)。以体重、腹内和皮下脂肪含量、肝重以及血清甘油三酯(TG)和总胆固醇(TC)水平为指标,观察ICAE对肥胖的预防作用;在实验第5周,连续5 d监测ICAE对小鼠24 h平均摄食量的影响;HE染色观察ICAE对脂肪组织的影响。分离和培养大鼠附睾来源的前脂肪细胞,尼罗红染色观察ICAE对分化脂肪细胞内脂滴形态的影响,Western blot法检测ICAE对细胞内过氧化物酶体增殖物激活受体γ(PPARγ)、脂滴包被蛋白1(Plin1)及激素敏感性脂肪酶(HSL)蛋白表达的影响。结果:ICAE可以显著抑制HFD引起的小鼠体重、腹内和皮下脂肪含量以及肝重的增加(P<0.01),并且显著降低血清TC和TG水平(P<0.01),但是对摄食量无显著影响;HE染色显示,ICAE能够显著减少HFD引起的白色脂肪细胞肥大。此外,在原代培养的大鼠分化脂肪细胞中,ICAE可以显著抑制细胞内脂滴的积累,并且显著下调脂肪分化关键转录因子PPARγ以及脂肪分化标志物Plin1和HSL的蛋白水平(P<0.01)。结论:ICAE对HFD诱导的小鼠肥胖具有预防作用,但对摄食量无明显影响;ICAE可以显著抑制脂肪分化过程,此作用可能与下调PPARγ的蛋白表达有关。     

Effects of ageing on the energy balance of food-restricted rats

AIMS: Age can alter energy balance by decreasing the resting metabolic rate. Food restriction can also change energy balance by decreasing energy expenditure as a mechanism of energy conservation. We investigated the influence of food restriction on the energy balance of rats at different ages. METHODS: Wistar EPM-1 female rats were used at ages of 3, 9, 15 and 21 months. At each age, two food intake schedules were provided: control (ad libitum) and food restriction (50%). Animals remained under these schedules for 30 days, and throughout this period body weight, food intake, and stool collection were controlled daily. On the 30th day, animals were killed, blood was collected and the carcasses and faeces were processed for analysis by pump calorimetry. Blood glucose, T(3), T(4) and rT(3) levels were determined. RESULTS: Food restriction reduced energy gain and gross food efficiency of animals at different ages, but more so in older animals. Food-restricted rats also had lower energy expenditure than controls. This reduction was about 40% of the energy expenditure of control animals irrespective of age. Water content increased and fat content decreased in the carcass of food-restricted animals. Serum T(3) and T(4) levels were lower in food-restricted animals pointing out to a major role of thyroid hormones in the mechanism of energy conservation exhibited by food-restricted animals. CONCLUSIONS: The mechanism of energy conservation takes place in all restricted animals and is very important for survival and for species preservation, mainly in aged animals in which food restriction is frequently aggravated by senescence-related organic disorders.     

Opiate receptors, food intake and obesity

The present studies tested the effect of acute and chronic administration of naloxone on food intake of lean and genetically obese (ob/ob) mice. Acute administration of naloxone, a drug which blocks opiate receptors, produced a greater reduction of food intake in obese (ob/ob) mice than in the lean littermates. For chronic experiments with naloxone, the daily feeding period was shortened to eight hours and two injections of naloxone were given four hours apart. With this procedure of scheduled-feeding the food intake of both lean and obese mice was depressed during the first hour after injecting naloxone. However, beginning on the second day of treatment, the lean mice began to eat more food than the untreated controls during the eight hour feeding period. Food consumption by lean mice reached values 140 to 200% above the control levels between the fourth and sixth day. In the obese mice the rise in food intake was more gradual and did not reach 200% of the control value until the sixth day. Body weight changes reflected the changes in food intake. In contrast to naloxone, chronic treatment with morphine lowered food intake and blocked the stimulatory effect of naloxone. Our findings suggest that endogenous opioids may play a role in signalling satiety and in regulating long-term energy balance.     

Leptin responsiveness in mice that ectopically express agouti protein

Agouti protein is an endogenous antagonist of melanocortin receptors (MCR), including MCR3 and MCR4, which have been implicated as part of the hypothalamic mechanism that mediates leptin-induced hypophagia. In this experiment we examined the effects of peripheral and central leptin administration in male and female beta-actin promoter (BAPa) mice that express agouti protein ectopically and have a phenotype that includes obesity and diabetes which is exaggerated in males compared with females. Intraperitoneal infusion of 10 microg leptin/day for 13 days caused weight loss and a transient inhibition of food intake in wild-type mice, with a greater effect in males than females. Male BAPa mice were resistant to leptin infusion whereas female mice lost weight. All of the mice lost body weight following a single intracerebroventricular injection of leptin but the effect was greater in female BAPa mice than any other group. There also was a delayed suppression of food intake that was the same for wild-type and BAPa female mice, whereas food intake recovered faster in BAPa than wild-type males. The dissociation between food intake and body weight loss implies a significant effect of leptin on energy expenditure in BAPa mice. These results demonstrate that the effect of leptin on energy balance is not entirely dependent upon the melanocortin system.     

Effect of kami-untan-to on the impairment of learning and memory induced by thiamine-deficient feeding in mice

We have recently reported that thiamine deficient (TD) mice show an impairment of learning and memory on the 20th day after start of TD feeding. Interestingly, it has been reported that the kampo medicine, "kami-untan-to" (KUT) may be useful as a potential therapeutic agent in diseases associated with cholinergic deficit such as Alzheimer's disease. In the present study, we investigated the effects of KUT on the impairment of memory-related behavior concomitant with psychoneuronal symptoms after TD feeding in mice. Oral administration of KUT had no effect on the food intake, body weight or locomotor activity in TD mice, but the mortality rate in the KUT-treated TD group was significantly lower compared with that in the non-treated TD group. Daily administration of KUT from the 1st day of TD feeding protected against the impairment of memory-related behavior induced by TD. The intensity of the choline acetyltransferase fluorescence decreased in the field of CA1 and dentate gyrus in the hippocampus in TD mice compared with pair-fed mice as the control group, and KUT treatment inhibited this decrease. These results suggest that the effect of KUT on the impairment of memory-related behavior induced by TD feeding may be closely related to the activation of cholinergic neurons in the hippocampus.     

Effects of dietary caloric density on feeding behavior in Mongolian gerbils (Meriones unguiculatus)

Total daily energy intake, water intake, body weight, and meal patterns were studied in Mongolian gerbils as a function of dietary caloric density. On diets ranging in caloric density from 2.25 kcal/g to 6.09 kcal/g, gerbils consumed an average of 40 kcal per 100 g of body weight per day. In comparison to gerbils fed ground Purina Laboratory Chow (4.2 kcal/g), gerbils presented with diets diluted with nonutritive cellulose increased food intake in proportion to the percentage of cellulose added. Gerbils given diets in which the caloric density was increased by the addition of fat, decreased food intake as a direct function of the added fat. Water intake was increased on the calorically diluted diets, and decreased on the concentrated diets. Body weight did not vary as a function of dietary conditions. On a standard pelleted diet (Noyes), gerbils ate approximately 18 meals a day. Average meal size was 0.4 g. When presented with calorically diluted pellets, gerbils maintained daily energy intake by increasing both meal frequency and meal size. There were no differences in food intake, meal frequency or meal size between the light and dark portions of the 24-hr cycle.     

Effects of ageing on the energy balance of food‐restricted rats

Aims: Age can alter energy balance by decreasing the resting metabolic rate. Food restriction can also change energy balance by decreasing energy expenditure as a mechanism of energy conservation. We investigated the influence of food restriction on the energy balance of rats at different ages. Methods: Wistar EPM‐1 female rats were used at ages of 3, 9, 15 and 21 months. At each age, two food intake schedules were provided: control (ad libitum) and food restriction (50%). Animals remained under these schedules for 30 days, and throughout this period body weight, food intake, and stool collection were controlled daily. On the 30th day, animals were killed, blood was collected and the carcasses and faeces were processed for analysis by pump calorimetry. Blood glucose, T₃, T₄ and rT₃ levels were determined. Results: Food restriction reduced energy gain and gross food efficiency of animals at different ages, but more so in older animals. Food‐restricted rats also had lower energy expenditure than controls. This reduction was about 40% of the energy expenditure of control animals irrespective of age. Water content increased and fat content decreased in the carcass of food‐restricted animals. Serum T₃ and T₄ levels were lower in food‐restricted animals pointing out to a major role of thyroid hormones in the mechanism of energy conservation exhibited by food‐restricted animals. Conclusions: The mechanism of energy conservation takes place in all restricted animals and is very important for survival and for species preservation, mainly in aged animals in which food restriction is frequently aggravated by senescence‐related organic disorders.     

Dengue-specific CD8+ T cells have both protective and pathogenic roles in dengue virus infection

To analyze roles of memory T cells in the pathogenesis of dengue (DEN) virus infection, a DEN virus-specific CD8+ cell clone (2D42 cell) was employed to investigate its in vivo function after DEN virus infection using an animal model. HepG2 grafted severe combined immunodeficient (HepG2-grafted SCID) mice were divided into three groups--group A: HepG2-grafted SCID mice were inoculated intraperitoneally (ip) with 2D42 cells and then ip-infected with DEN virus type 2 (DEN-2); group B: HepG2-grafted SCID mice were inoculated with naive mouse thymocytes (NMT) and then ip-infected with DEN-2; group C: HepG2-grafted SCID mice were ip-infected with DEN-2 alone. Eighty percentage of group A mice died at average day 12.8 post-infection (p.i.) and 20% of them recovered from the disease after showing clinical signs and survived more than 3 months. They showed severe manifestations including dramatically decreased platelet count, decreased hematocrit, anemia, viremia and high frequency of histopathological changes in several organs. All of group B mice also showed the above severe clinical signs. One hundred percentage mortality rate was noted in these mice and death occurred at average day 10.8 p.i., which was the earliest among three groups. Although the mice from group C showed 100% mortality rate and similar clinical signs, death observed in these mice occurred at average day 17.4 p.i. and the manifestations were slight and developed slowly. Our results suggested both protective and pathogenic roles for DEN-specific CD8+ T cell in DEN virus infection, whereas NMT did not provided any protection.     

Hypothalamic implants of dilute estradiol fail to reduce feeding in ovariectomized rats

To investigate further the site where estradiol (E(2)) inhibits food intake, we tested the effects on feeding of subcutaneous and intrahypothalamic implants of 10% E(2) benzoate in cholesterol (CHOL) or CHOL alone. E(2) was implanted subcutaneously in Silastic tubes, and intrahypothalamically via bilateral 29-gauge cannulas into the paraventricular nucleus (PVN) or the medial preoptic area (MPA) of ovariectomized (OVX) Sprague-Dawley and Long-Evans rats. Three-day implant periods followed 3-day baseline periods. Rats were allowed ad libitum access to chow and tap water, and food intake and body weight were measured each day. Subcutaneous 10% E(2) implants in Sprague-Dawley rats reduced food intake 21% on Day 2 and 34% on Day 3 (P's<.01) and decreased 3-day body weight gain 11 g (P<.05). In contrast, 10% E(2) implants in the PVN of Sprague-Dawley rats did not change food intake or body weight. Implants of 10% or 20% E(2) in the MPA also failed to decrease food intake. MPA implants of 10% E(2) decreased body weight gain 8 g (P<.05), but MPA implants of 20% E(2) decreased weight gain only 4 g (P>.05). To determine whether the strain of rat affected our negative results on food intake, we implanted 10% E(2) into the PVN of Long-Evans rats. Again, PVN E(2) did not decrease food intake significantly in comparison to the pretest baseline. PVN E(2) did, however, decrease body weight gain 5 g and decreased food intake 6% compared to rats with implants of CHOL (both P<.05), but these effects appeared to be due to an increase in feeding in the CHOL group in comparison to their baseline. Finally, CHOL and E(2) implants did not impair the responsivity of the PVN because acute implants of norepinephrine (NE) into the PVN of E(2)- or CHOL-treated Long-Evans rats significantly increased food intake. Our results do not support the hypothesis that E(2)'s actions in either the PVN or the MPA are sufficient to account for its inhibitory effects on feeding.