The effect of chronic stress on prenatal development of the central nervous system

Abstract

The survival of developing embryos depends on the control and maintenance of homeostasis. Stress caused by chronic immobilization during pregnancy in rats may alter the normal development of the nervous system and increase susceptibility to psychiatric disorders. We investigated the effects of chronic stress on cell proliferation in the forebrains of embryos at 12 days of gestation, and in the hippocampus, dentate gyrus and cortex in embryos at 17 and 21 days of gestation. We examined serial sections of the embryonic brains of control and stressed rats at days 12, 17 and 21 of gestation. Brain sections were immunolabeled with anti-PCNA and stereological analysis was performed on 540 images. The results showed no statistical differences on days 12 and 17 of gestation in the proliferation area of the structures studied, whereas on day 21 of gestation, proliferation decreased in the cortex and dentate gyrus of embryos of the stressed group. These changes were related to decreased prolactin and increased corticosterone concentrations in the plasma.     

嗜肺巴氏杆菌在实验大鼠和小鼠中的传染性研究

目的观察不同来源的嗜肺巴氏杆菌在实验大鼠和小鼠中的传染性.方法取源于野鼠、实验大鼠和小鼠的嗜肺巴氏杆菌3株,对30只受试大鼠和小鼠进行交叉人工感染,并于感染后不同时期取咽拭子分离培养,对感染前后菌株,应用RAPD-PCR、SDS-PAGE和Western blot进行基因型、蛋白和抗原成份比较,以及生物学特性的比较.结果受试实验动物对3株嗜肺巴氏杆菌均易感,被接种的动物能稳定携带嗜肺巴氏杆菌直到试验结束,重新分离的嗜肺巴氏杆菌在生物学特性、蛋白成份、抗原性和基因型方面无明显改变.结论同一株嗜肺巴氏杆菌能在实验大鼠和小鼠中相互传染.     

Effects of temperature on the post-diapause embryonic development and the hatching time in three grasshopper species (Orth., Acrididae)

A study was conducted to determine the effects of six constant temperatures (15, 20, 25, 30, 35 and 40°C) on the post‐diapause embryonic development and the hatching time in three grasshopper species –Omocestus haemorrhoidalis (Charp.), Calliptamus abbreviatus Ikonn. and Chorthippus fallax (Zub.) – from the Inner Mongolian steppe. The results indicate that the species differ in the developmental rates, survival curves and cumulative hatching probabilities. The eggs of O. haemorrhoidalis had the fastest developmental rate with a low developmental threshold temperature of 9.9°C and the sum of effective temperature (SET) 211.2 degree‐days (DD). The corresponding values were 10.9°C and 210.6 DD for C. abbreviatus, 10.5°C and 240.2 DD for Ch. fallax respectively. The SET at which 50% of post‐diapause eggs hatched were 252.0 DD for O. haemorrhoidalis, 262.8 DD for C. abbreviatus, and 273.3 DD for Ch. fallax. The predicted maximal hatch ability of O. haemorrhoidalis (91.17%), C. abbreviatus (75.67%) and Ch. fallax (94.07%) occurred at 23.7, 29.0 and 31.3°C, respectively. The thermal death points of each species were reached at 43.3, 45.0 and 48.6°C. The optimal temperature ranges were 12.2–35.2°C for O. haemorrhoidalis, 21.7–36.3°C for C. abbreviatus and 20.9–41.7°C for Ch. fallax respectively. These results suggest that O. haemorrhoidalis adapt to hatch at a lower temperature range, C. abbreviatus adapt to mid‐temperature range, while Ch. fallax adapt to hatch at a higher temperature range. Although the SET of Ch. fallax is more than that of the other two species, it is not sufficient to explain the hatching sequence of the species in springtime. The results also indicate that Ch. fallax and O. haemorrhoidalis have wider adaptive temperature range than C. abbreviatus.     

早孕因子研究进展

早孕因子既是一种微量蛋白又是一种妊娠相关蛋白,其纯品的获得尤为重要。简要论述了早孕因子的本质和功能,并就早孕因子在超早期妊娠诊断中的实际功能价值进行了深入探讨;结合早孕因子的国内外研究进展和生理生化特点提出了2种蛋白质提纯方案;针对当前早孕因子提纯及检测方法中存在的问题进行了讨论。     

Pregnancy Loss Following Coxsackievirus B3 Infection in Mice during Early Gestation Due toHigh Expression of Coxsackievirus-Adenovirus Receptor (CAR) in Uterus and Embryo

Coxsackieviruses are important pathogens in children and the outcomes of neonatal infection can be serious or fatal. However, the outcomes of coxsackievirus infection during early gestation are not well defined. In this study, we examined the possibility of vertical transmission of coxsackievirus B3 (CVB3) and the effects of CVB3 infection on early pregnancy of ICR mice. We found that the coxsackievirus and adenovirus receptor (CAR) was highly expressed not only in embryos but also in the uterus of ICR mice. CVB3 replicated in the uterus 1 to 7 days post-infection (dpi), with the highest titer at 3 dpi. The pregnancy loss rate in mice infected with CVB3 during early gestation was 38.3%, compared to 4.7% and 2.7% in mock-infected and UV-inactivated-CVB3 infected pregnant mice, respectively. These data suggest that the uterus and embryo, which express abundant CAR, are important targets of CVB3 and that the vertical transmission of CVB3 during early gestation induces pregnancy loss.     

孕期家装污染对子代大鼠脑组织结构和认知功能的影响

目的:建立孕期家装污染大鼠模型,并探讨其对孕鼠子代神经元形态和神经行为的影响.方法:将22只成年孕鼠随机分为对照组和染毒组,分别在孕早期(D1-D10)给予相应的处理.在生后不同时间观察新生大鼠大脑的发育并检测脑组织重量,同时观察新生大鼠皮层神经元的形态变化并检测学习记忆活动.结果:各组新生大鼠脑组织无畸形,且各组大鼠脑组织重量无显著变化,但与对照组相比染毒组皮层神经元的排列及形态欠规则.出生一月后染毒组皮层神经元突起的数量及长度均少于对照组.行为学检测观察到染毒组大鼠其子代大鼠的学习记忆能力明显低于对照组.结论:家装污染物可导致新生大鼠海马神经元的形态学改变并抑制神经元突起的发育与生长,对大鼠的学习记忆功能有明显的损害作用.     

Kisspeptins在孕早期血浆和胎盘组织中的表达及其意义

目的:研究kisspeptins在孕早期血浆和胎盘组织中的表达,拟探讨其来源及其在妊娠中意义.方法:采用酶联免疫吸附法(ELISA),检测40例孕早期妇女和35例正常未妊娠妇女血浆kisspeptins的表达水平,且分析其与hCG的相关性;采用免疫组织化学方法进行其组织学定位.结果:(1)kisspeptins在妊娠组...     

Protective Effects of Garlic and Silymarin on NDEA-Induced Rats Hepatotoxicity

Background ­— The present study was conducted to investigate the chemopreventive effects of garlic extract and silymarin on N-nitrosodiethylamine (NDEA) and carbon tetrachloride (CCl₄)-induced hepatotoxicity in male albino rats. Methods and Results — Animals were pretreated with garlic, silymarin or both for one week prior to the injection of NDEA. Then animals received a single injection of NDEA followed by weekly subcutaneous injections of CCl₄ for 6 weeks. Oral administration was then continued along with the injection of CCl₄ for the duration of the experiment. Serum aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), hepatic lipid peroxidation (LPO), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione-S-transferase (GST) and glutathione reductase (GSR) were measured. Injection of NDEA induced a significant elevation in serum AST, ALT and ALP. In the liver, NDEA increased oxidative stress through the increase in LPO and decrease in SOD, and GSH-dependent enzymes. Although administration of garlic or silymarin significantly reduced the liver toxicity, combined administration was more effective in preventing the development of hepatotoxicity. Conclusion — These novel findings suggest that silymarin and garlic have a synergistic effect, and could be used as hepatoprotective agents against hepatotoxicity.     

早发型重度子痫前期终止妊娠对母婴预后的影响分析

目的:探讨早发型重度子痫前期终止妊娠时机对母婴预后结局的作用,为临床实践提供指导。方法:从2007年1月至2010年12月期间在我院妇产科分娩并为重度子痫前期患者中随机选取135例作为研究对象。按终止妊娠时间分为两组,A组<32周、32周≤B组≤34周。对两组均终止妊娠,比较两组间血压状况、尿蛋白、血小板、凝血、眼底状况及胎儿监护。结果:A组的胎盘早剥、子痫和肾功能损害的发生率略高于B组,然而差异均无统计学意义(P>0.05)。A组的新生儿窒息率,新生儿呼吸窘迫综合征发生率,围产儿死亡率等3个指标均明显高于B组,且卡方检验显示,两组比较差异有显著性(P<0.05)。结论:对于终止妊娠的时间、方式应根据患者的状况进行综合考虑。无论选择何时终止妊娠或治疗,都应该综合考虑母婴两方面的状况,密切进行监护,尽量获得良好的结局。     

Effect of Food Restriction on Ghrelin in Normal‐Cycling Female Rats and in Pregnancy

Objective: Ghrelin is a 28‐amino‐acid acylated peptide that was recently identified as the endogenous ligand for the growth hormone secretagogue receptor. Previous studies have shown that ghrelin potently increases growth hormone release and food intake. The aim of this study was to clarify the physiological implications of ghrelin in the regulation of energy balance, by assessing the effect of undernutrition throughout 21 days in normal‐cycling and pregnant rats on ghrelin. Research Methods and Procedures: We have determined ghrelin levels by radioimmunoassay and gastric ghrelin mRNA expression by Northern blot analysis during 21 days of chronic food restriction (30% of ad libitum available diet) in normal‐cycling female rats and in pregnancy. Results: Our results show that chronic food restriction led to an increase in plasmatic ghrelin levels in normal‐cycling female rats. In pregnancy, ghrelin plasmatic levels were enhanced particularly during the latter part of gestation (19 and 21 days) compared with pregnant rats with free access to food. Gastric ghrelin mRNA expression showed a similar expression pattern, being higher in the food‐restricted group than in the group fed ad libitum, in normal‐cycling as well as in pregnant rats. Discussion: These observations indicate that ghrelin plasmatic levels and ghrelin gastric mRNA are up‐modulated during undernutrition in normal‐cycling rats and in pregnancy. These findings suggest that increased ghrelin levels may have a role in mediating the physiological responses to undernutrition and could represent an adaptative response to prevent long‐lasting alterations in energy balance and body weight homeostasis.     

Does the combination of embryonic diapause and superfoetation occur in the stoat Mustela erminea? A reinterpretation of existing data

Superfoetation is when ovulation and fertilisation occur during pregnancy. Coupled with embryonic diapause, superfoetation presents an intriguing female reproductive advantage in terms of cryptic choice of males. Unfortunately, few studies have identified species possessing both superfoetation and embryonic diapause. We aim to reinterpret existing data on reproductive physiology in the stoat Mustela erminea and suggest it may be a previously overlooked species that possesses this combination. By increasing our knowledge of such reproductive systems, we can further our understanding of a cryptic sexually selected function and better explain the evolutionary gain and loss of embryonic diapause in mammals.     

痛血康胶囊对早孕大鼠不完全流产模型的治疗作用

目的：探讨痛血康胶囊治疗早孕SD大鼠不完全流产模型产后出血的疗效及作用机制。方法：1）受孕7 d予米非司酮和米索前列醇,造成早孕不完全流产模型,痛血康治疗7 d观察并记录SD大鼠离体子宫平滑肌活动情况及病理组织学改变。2）用小鼠尾尖取血法,观察痛血康对小鼠出凝血时间的影响。3）用小鼠耳廓肿胀和SD大鼠棉球肉芽肿两个模型,观察痛血康的抗炎作用。4）用皮下注射肾上腺素加冰水刺激所致SD大鼠血瘀模型,观察痛血康的活血化瘀作用。结果：痛血康能增强早孕不完全流产SD大鼠子宫平滑肌收缩强度,促进残存的胚囊组织排出;能降低血瘀模型SD大鼠全血和血浆黏度,缩短小鼠出凝血时间;对二甲苯所致小鼠耳廓肿胀和SD大鼠棉球肉芽肿有明显抑制作用。结论：痛血康在早孕SD大鼠中具有治疗产后出血的作用,可能与增强流产SD大鼠的子宫收缩强度、促进残留在宫腔的绒毛或蜕膜组织排出、缩短出凝血时间、抑制炎症等有关。     

低温和变温诱导对飞蝗胚胎发育的影响

【目的】飞蝗Locusta migratoria(Linnaeus)是我国乃至全世界广泛发生的重要农业害虫,其种群暴发会给农作物造成重大为害和减产。飞蝗种群发生动态受低温及变温的影响,但低温和变温如何作用于胚胎发育和是否诱导胚胎滞育的发生,目前尚不清楚。【方法】本文在对飞蝗胚胎发育特点观察鉴定的基础上,研究了胚胎发育中期恒定低温诱导、诱导后恢复、发育中期变温诱导及发育早期低温诱导等条件对胚胎发育进程的影响。【结果】研究发现,胚胎发育起点温度下非致死温度7.5℃处理促使胚胎发育历期变异增加,而25~30℃高温下胚胎发育整齐。7.5℃处理时间长短对胚胎发育影响不明显,但该低温培育时间长短影响后期常温下的胚胎发育,即7.5℃下长期低温可能促进25℃或30℃下的胚胎的发育。25℃以下变温温度影响胚胎发育进展,但影响胚胎发育的限制因子主要是发育起点以上温度。【结论】因此,温度作为单一环境因子,其特定的低温和变温处理不仅没有诱导胚胎滞育的发生,反而促进后期胚胎在常温下的发育。本研究结果对揭示温度变化对个体发育和种群动态影响及预测飞蝗种群发生有重要的指导意义。     

右美托咪定对慢性应激抑郁妊娠大鼠子代发育及空间学习记忆能力的影响

妊娠期抑郁症可以通过影响孕妇的生理和心理变化,进而影响新生儿的正常生长发育,右美托咪定(dexmedetomidine,Dex)可以有效缓解抑郁情绪,降低产后抑郁症的发生。为探讨Dex对慢性应激抑郁妊娠大鼠子代发育及空间学习记忆能力的影响,将60只妊娠大鼠随机分为对照组、模型组、低剂量右美托咪定组和高剂量右美托咪定组,统计各组大鼠孕育率、平均产仔率和平均仔鼠成活率,并记录子代大鼠出生后体质量变化及学习记忆能力;检测子鼠脑组织乙酰胆碱(acetylcholine,Ach)、5-HT含量、TChE活力及海马组织CREB、p-CREB及BDNF的表达。结果显示,Dex可以以剂量依赖的方式提高慢性应激抑郁妊娠大鼠子代的平均成活率,调节脑组织Ach、5-HT、CREB、p-CREB和BDNF的水平,改善子鼠的学习记忆能力。结果表明,Dex可能通过调控神经递质和促进CREB信号传导,改善慢性应激抑郁妊娠大鼠的子代鼠学习记忆能力。研究探究了 Dex对妊娠期抑郁症大鼠子代生长发育和空间学习记忆能力的影响,以期指导临床治疗。     

Effects of oestrous synchronization with altrenogest in gilts on endometrial and embryonic characteristics

The use of altrenogest (ALT) supplementation for oestrous synchronization improves subsequent reproductive performance of gilts and sows. However, the causes of this improvement in reproductive performance after ALT treatment are not fully/clearly understood. The objective of this study was to evaluate the effects of ALT supplementation for oestrous synchronization in gilts on the endometrial glands and embryonic development characteristics at 28 days of pregnancy. Pregnant gilts were divided into two experimental treatments: Control (did not receive ALT; n = 9 gilts) and ALT (ALT feeding at 20 mg/day for 18 days; n = 9 gilts). At 28 days of pregnancy, six gilts from each treatment were slaughtered, and reproductive tracts were immediately evaluated. There was no statistical difference (P > 0.05) between treatments regarding ovulation rate, number of embryos, number of vital embryos and number of non-vital embryos. Embryo weight, length and embryonic vesicle weight were lower in ALT treatment compared with Control (P < 0.01), and it was lower in the cervical uterine region compared with apex uterine region, respectively (P < 0.05). Higher values of gland duct area, gland duct perimeter, percentage of the glandular area and total endometrial area were observed in ALT treatment compared with Control (P < 0.05). The use of ALT during 18 days for oestrous synchronization in gilts increased the gland duct area, perimeter and total endometrial area but did not increase the embryo number and embryo size at day 28 of pregnancy.     

C肽对糖尿病大鼠肾脏的影响

比较C肽和胰岛素对大鼠糖尿病肾病的治疗作用。方法:选取Wistar大鼠40只,分为正常对照组(NG组)和糖尿病组(DM组),糖尿病组链脲佐菌素诱发大鼠成模后,随机分为三组:糖尿病组(DM组)、胰岛素组(IG组)和C肽组(ICG组)。治疗8周后测定各组大鼠24小时尿白蛋白排泄率(UAER)、肾重/体重,并观察糖尿病大鼠肾脏超微结构变化。结果:24小时尿白蛋白排泄率:糖尿病组明显增加,C肽组明显低于糖尿病组和胰岛素组,差异具有显著性。大鼠肾脏超微结构变化:各组大鼠肾小球截面积、肾小球平均体积(MGV)、细胞外基质/肾小球截面积比值、细胞外基质截面积、肾小球基底膜厚度相比,糖尿病组明显升高,C肽组较胰岛素组和糖尿病组明显下降,差异具有显著性。结论:C肽治疗可以降低24小时尿白蛋白排泄率,改善糖尿病大鼠肾脏超微结构病变。     

Embryonic loss in mares: Pregnancy rate, length of interovulatory intervals, and progesterone concentrations associated with loss during days 11 to 15

Pregnancy rates, length of interovulatory intervals, and progesterone concentrations were examined in mares which had ultrasonically detected collections of fluid in the uterine lumen and in mares which lost the embryonic vesicle during Days 11 to 15 and did not become pseudopregnant. In mares with embryonic loss, the loss rate for mares with re-established pregnancies (9 18 ) was greater (P<0.05) than the loss rate for all pregnancies (38 154 ), indicating repeatability. Pregnancy rates were higher (P<0.01) in controls (100 177 ) than in mares with intrauterine fluid collections (2 34 ) or mares with embryonic loss (10 33 ), excluding the pregnancy associated with embryonic loss. The mean length (days) of the interovulatory interval was reduced (P<0.05) in mares with intrauterine fluid collections (20.4 +/-0.9) and in mares with embryonic loss both for the intervals in which loss occurred (19.6 +/-0.7) and for intervals in which pregnancy was not detected (21.0 +/-1.0; controls, 23.5 +/-0.6). Mean progesterone concentration (ng/ml) on Day 7 was lower (P<0.05) in mares with intrauterine fluid collections (8.8 +/-1.8) and in mares with embryonic loss (12.1 +/-1.1) than in pregnant controls (17.2 +/-0.9) and nonpregnant controls (17.5 +/-0.1). The embryonic loss seemed attributable to uterine-induced luteolysis in association with uterine inflammation, but the possibility of involvement of a primary luteal inadequacy or other factors in at least some of the mares was not eliminated.     

3670 例早期妊娠妇女梅毒血清学检查及处理

目的:了解早期妊娠妇女梅毒感染情况,采取防治措施,减少先天梅毒的发生。方法:采用梅毒明胶颗粒试验(TPPA)和梅毒甲苯胺红试验(TRUST)对早期妊娠妇女进行梅毒血清学检查,两项结果均阳性者诊为妊娠期梅毒,可采取驱梅治疗或终止妊娠。结果:3670例早期妊娠妇女中,确诊为妊娠期梅毒的29例,其中TRUST滴度大于1:8的有8例,小于1:8的有21例;有12人接受驱梅治疗,有17人选择终止妊娠。结论:在早期妊娠妇女中进行梅毒血清学检查,可及早采取措施,减少先天梅毒的发生。     

药械联合终止早孕的临床研究

目的：探讨药物联合负压吸宫术对哺乳期妊娠流产的有效性及安全性。方法：选择200例哺乳期早期妊娠妇女随即分为药械联合终止早孕组（药械联合组）和负压吸宫术终止早孕组（负压吸宫组）,比较两组间各临床指标。结果：药械联合组I级、II级、III级疼痛评价均较负压吸宫组明显降低（P〈0．05）。两组在完全流产率和不全流产率上差异均无统计学意义（P〉0．05）。药械联合组宫腔吸出组织量（2．48＋0．77）mL明显高于（12．11±4．23）mL（P〈0．05）。两组术后均无感染、闭经、器械性损伤和宫腔或宫颈粘连等并发症发生。结论：药械联合终止早孕有效、安全,疼痛及刮宫程度较轻。     

Effects of heat stress on mammalian reproduction

Heat stress can have large effects on most aspects of reproductive function in mammals. These include disruptions in spermatogenesis and oocyte development, oocyte maturation, early embryonic development, foetal and placental growth and lactation. These deleterious effects of heat stress are the result of either the hyperthermia associated with heat stress or the physiological adjustments made by the heat-stressed animal to regulate body temperature. Many effects of elevated temperature on gametes and the early embryo involve increased production of reactive oxygen species. Genetic adaptation to heat stress is possible both with respect to regulation of body temperature and cellular resistance to elevated temperature.