先天性巨细胞病毒感染状况及检测方法的研究进展

巨细胞病毒感染在人群中非常常见,尤其对于新生儿来说,先天性巨细胞病毒感染可能导致中枢神经系统损伤及其他相关疾病,潜在危害很大。国内外均已针对该病的发病情况开展了大量研究,并发展出多种检测方法。本文对先天性巨细胞病毒在国内外感染的状况以及相关检测方法的研究现状进行综述。     

豚鼠妊娠期感染巨细胞病毒的研究

本实验观察了豚鼠巨细胞病毒感染对怀孕豚鼠的影响。从皮下和心腔接种病毒感染动物,接种病毒的时间在动物妊娠早期。接种病毒后,二组动物都出现病毒血症,从动物的脾、肺和唾液腺均分离到病毒。病毒在唾液腺持续存在。皮下接种组和心腔接种组各有38％和44％的孕鼠的胚胎感染了病毒,各有27％和25％的孕鼠发生流产,皮下接种组还有63％的孕鼠怀有死胎。本实验为研究巨细胞病毒感染提供了动物模型,证实了血源途径也可以引起豚鼠的先天性巨细胞病毒感染。     

人巨细胞病毒潜伏感染机制的研究进展

人巨细胞病毒可通过原发感染或者潜伏感染再激活而广泛传播.基于对人巨细胞病毒AD169株和Towne株基因测序的完成,以及人巨细胞病毒的基因功能研究及其相关动物模型如小鼠模型、猪模型、恒河猴模型等的研究,人巨细胞病毒感染的潜伏机制研究取得了一定进展.本文从人巨细胞病毒的感染机制、免疫应答和免疫逃避三方面对人巨细胞病毒潜伏感染机制的研究现状进行简要综述.     

噪声对大鼠学习记忆的影响

噪声污染已无可争议地成为城市的主要环境公害之一。在噪声对学习、记忆影响程度的研究方面,国内外多数学者认为噪声主要影响学习能力和短时性记忆,而对长时性记忆没有影响或影响较小,故研究工作多集中于短时记忆功能上。目前有关噪声对学习记忆影响程度的大小、作用途径和机理仍很不清楚。本研究以噪声作用下动物电击回避反应为模型,     

巨细胞病毒感染与SARI肺炎病例的相关性研究

探讨巨细胞病毒感染与住院严重急性呼吸道感染(SARI)肺炎的相关性.以67例符合严重急性呼吸系统感染临床诊断标准的住院病例为研究对象,同时以81例流感样门诊病例作为对照,使用荧光定量PCR方法检测所有研究对象的巨细胞病毒感染情况.采用二分类logistic回归模型分析巨细胞感染与住院严重急性呼吸道感染肺炎病例的关联.巨细胞病毒在呼吸道感染病例中有较高的阳性率,阳性率随年龄呈下降趋势.80％以上巨细胞病毒阳性病例存在与其他常见呼吸道病原共感染情况.Logistic回归分析表明:年龄和多病原共感染是SARI肺炎发生的危险因素,单独CMV阳性与SARI肺炎的发生没有显著相关性.SARI肺炎中CMV与其他呼吸道病原共感染概率高,临床上应加强对呼吸道感染病例的巨细胞病毒检测.     

利用孕早期人胚绒毛组织进行先天性巨细胞病毒感染诊断的研究

新生儿出生缺陷已成为影响人口素质的重要因素。在引起出生缺陷的诸因素中,宫内病毒感染是一个重要原因。风疹病毒等对胎儿的影响早巳为人们所熟悉,而巨细胞病毒(cytomegalovirus,CMV)对胎儿的危害,近年来已受到人们的重视。据国内外调查,在新生儿中先天性CMV感染的发生率在0.5—2.0％之间。目前对先天性CMV感染的研究主要用新生儿尿样和脐带血作为研究材料。从产前诊断的角度考虑,     

特发性血小板减少性紫癜与巨细胞病毒、EB 病毒感染相关性

目的:探讨小儿特发性血小板减少性紫癜(ITP)与巨细胞病毒、EB病毒感染的关系。方法:实验组:48例确诊断为ITP患儿,对照组:44例同期呼吸道感染患儿,应用酶联免疫吸附法(ELISA)对两组小儿外周血进行巨细胞病毒IgM抗体(HCMV-IgM)、EB病毒感染IgM抗体(EB-IgM)检测。结果:48例ITP患儿中HCMV-IgM抗体阳性者20例,阳性率为41.67%,明显高于对照组,两组之间差异有显著性(P<0.01);EBV-IgM抗体阳性者14例,阳性率为29.17%,明显高于正常对照组,两组之间差异有显著性(P<0.05)。结论:1、巨细胞病毒感染是引起特发性血小板减少性紫癜的重要原因之一,且通过临床观察巨细胞病毒感染引起的ITP患儿病情重,病程长,治疗时间长,转为慢性ITP的可能性大;2、EB病毒感染可能是引起特发性血小板减少性紫癜的原因之一,并且EB病毒感染引起的特发性血小板减少性紫癜病情也偏重。     

特发性血小板减少性紫癜与巨细胞病毒、EB病毒感染相关性

目的：探讨小儿特发性血小板减少性紫癜（ITP）与巨细胞病毒、EB病毒感染的关系。方法：实验组：48例确诊断为ITP患儿,对照组：44例同期呼吸道感染患儿,应用酶联免疫吸附法（ELISA）对两组小儿外周血进行巨细胞病毒IgM抗体（HCMV-IgM）、EB病毒感染IgM抗体（EB-IgM）检测。结果：48例ITP患儿中HCMV-IgM抗体阳性者20例,阳性率为41.67%,明显高于对照组,两组之间差异有显著性（P〈0.01）;EBV-IgM抗体阳性者14例,阳性率为29.17%,明显高于正常对照组,两组之间差异有显著性（P〈0.05）。结论：1、巨细胞病毒感染是引起特发性血小板减少性紫癜的重要原因之一,且通过临床观察巨细胞病毒感染引起的ITP患儿病情重,病程长,治疗时间长,转为慢性ITP的可能性大;2、EB病毒感染可能是引起特发性血小板减少性紫癜的原因之一,并且EB病毒感染引起的特发性血小板减少性紫癜病情也偏重。     

人巨细胞病毒感染对树突细胞功能的影响

人巨细胞病毒(HCMV)对人多为潜伏感染,但在免疫受损人群中,该病毒感染后会引起严重的后果.人巨细胞病毒感染人体后,可从多条途径干扰宿主细胞的生长、分化,诱导细胞恶变;人巨细胞病毒的IE基因具有抑制凋亡的功能.树突细胞是机体内功能最强的抗原呈递细胞,在免疫应答中发挥重要作用.HCMV感染后,能下调树突细胞表面的主要组织相容性复合物Ⅰ、Ⅱ类分子,CD80,CD86和CD40的表达,也使黏附分子如ICAM-3、ICAM-2等的表达发生改变.由此,人巨细胞病毒逃避了细胞免疫应答,引起持续感染或潜伏感染.     

MAPK信号转导通路与人巨细胞病毒感染

MAPK信号转导通路参与了人巨细胞病毒的致病过程。MAPK通路中的ERK和p38通路在人巨细胞病毒复制周期中起重要作用,通过磷酸化转录因子引起病毒及宿主相关基因的转录,从而调控人巨细胞病毒的复制;人巨细胞病毒的包膜糖蛋白及其他多种基因表达产物可通过不同机制以一定时序激活MAPK通路,调节自身及宿主细胞相应基因表达,以利于病毒完成其生活周期,并参与病毒的致病过程。深入研究MAPK信号转导通路与人巨细胞病毒感染的关系可为治疗该病毒感染引起的疾病提供新的治疗靶点。     

牛磺酸对学习记忆影响的研究现状

牛磺酸作为一种条件必须氨基酸对学习记忆能力的影响受到越来越多的关注,许多研究证明适量牛磺酸的添加可明显提高大鼠的记忆能力。通过牛磺酸对神经细胞、基因、激素、离子、受体、酶类等的作用,对其影响学习记忆方面的研究现状作出综述。     

Learning capacity and memory of normal and Toxoplasma-infected laboratory rats and mice

An experimental Toxoplasma-infection affects the learning performance and the memory of laboratory rats and mice. The investigations yielded the following results: 1. Maze experiments with rats showed that infection significantly reduces the learning performance of the infected animals. However, no significant differences were found between infected rats inoculated at varying times prior to training. In contrast to the learning capacity, memory does not seem to be impaired at all by infection. 2. Compared to rats, the learning capacity of mice is much more conspicuously retarded by a Toxoplasma-infection. In the memory test, the infected animals remained significantly below the performance level of the controls on all days, indicating that their memory was severely affected. 3. A significant correlation was established between the learning performance of the mice and the number of brain cysts. It is assumed that the cysts contribute to the impairment of learning ability. The fact that animals infected for a longer period usually show improved test performances further supports this assumption. This coincides with the decrease in brain cysts. Nevertheless, the clusters of necrosis developing together with the cysts in the nervous tissue might also cause learning retardation. 4. In mice, infection with an avirulent Toxoplasma-strain does not always take a wholly asymptomatic course. When observing the animals closely, a few of them could be seen to run in 'circles' with their heads bent to one side when moving and sitting, which might be interpreted as an impairment of the sense of balance. 5. Another effect of the Toxoplasma-infection in the animal species used is the significantly reduced activity observed on many days of training.     

Cytomegalovirus in the mononucleosis syndrome in children

In 7 children aged 18 months to 7 years isolated from a group of 128 children with infectious mononucleosis the cytomegalovirus infection was found. Infection was diagnosed by determination of antibodies against immediate early and late CMV antigen by means of the ELISA test. Besides that, antibodies were determined against the capsid antigen and early antigen of EB virus by the method of indirect immunofluorescence. In four children only cytomegalovirus infection was found and three had a mixed infection with both viruses and the diagnosis in these cases was: infectious mononucleosis (due to EBV) with coexistent or following CMV infection. In the sera of two children with cytomegalovirus mononucleosis changes were observed in the antibodies against EBV which is explained as a result of interactions between CMV and EBV in the organism of the host.     

The Development of Associate Learning in School Age Children

Associate learning is fundamental to the acquisition of knowledge and plays a critical role in the everyday functioning of the developing child, though the developmental course is still unclear. This study investigated the development of visual associate learning in 125 school age children using the Continuous Paired Associate Learning task. As hypothesized, younger children made more errors than older children across all memory loads and evidenced decreased learning efficiency as memory load increased. Results suggest that age-related differences in performance largely reflect continued development of executive function in the context of relatively developed memory processes.     

Rule-Based Category Learning in Children: The Role of Age and Executive Functioning

Rule-based category learning was examined in 4–11 year-olds and adults. Participants were asked to learn a set of novel perceptual categories in a classification learning task. Categorization performance improved with age, with younger children showing the strongest rule-based deficit relative to older children and adults. Model-based analyses provided insight regarding the type of strategy being used to solve the categorization task, demonstrating that the use of the task appropriate strategy increased with age. When children and adults who identified the correct categorization rule were compared, the performance deficit was no longer evident. Executive functions were also measured. While both working memory and inhibitory control were related to rule-based categorization and improved with age, working memory specifically was found to marginally mediate the age-related improvements in categorization. When analyses focused only on the sample of children, results showed that working memory ability and inhibitory control were associated with categorization performance and strategy use. The current findings track changes in categorization performance across childhood, demonstrating at which points performance begins to mature and resemble that of adults. Additionally, findings highlight the potential role that working memory and inhibitory control may play in rule-based category learning.     

The role of α-synuclein and tau hyperphosphorylation-mediated autophagy and apoptosis in lead-induced learning and memory injury

Lead (Pb) is a well-known heavy metal in nature. Pb can cause pathophysiological changes in several organ systems including central nervous system. Especially, Pb can affect intelligence development and the ability of learning and memory of children. However, the toxic effects and mechanisms of Pb on learning and memory are still unclear. To clarify the mechanisms of Pb-induced neurotoxicity in hippocampus, and its effect on learning and memory, we chose Sprague-Dawley rats (SD-rats) as experimental subjects. We used Morris water maze to verify the ability of learning and memory after Pb treatment. We used immunohistofluorescence and Western blotting to detect the level of tau phosphorylation, accumulation of α-synuclein, autophagy and related signaling molecules in hippocampus. We demonstrated that Pb can cause abnormally hyperphosphorylation of tau and accumulation of α-synuclein, and these can induce hippocampal injury and the ability of learning and memory damage. To provide the new insight into the underlying mechanisms, we showed that Grp78, ATF4, caspase-3, autophagy-related proteins were induced and highly expressed following Pb-exposure. But mTOR signaling pathway was suppressed in Pb-exposed groups. Our results showed that Pb could cause hyperphosphorylation of tau and accumulation of α-synuclein, which could induce ER stress and suppress mTOR signal pathway. These can enhance type II program death (autophgy) and type I program death (apoptosis) in hippocampus, and impair the ability of learning and memory of rats. This is the first evidence showing the novel role of autophagy in the neurotoxicity of Pb.     

Adoptive immunotherapy of murine cytomegalovirus adrenalitis in the immunocompromised host: CD4-helper-independent antiviral function of CD8-positive memory T lymphocytes derived from latently infected donors.

The ability of memory T lymphocytes derived from latently infected mice to control murine cytomegalovirus disease in the immunocompromised host was studied by adoptive transfer experiments. At a stage of pathogenesis when virus had already colonized target tissues, a therapeutic antiviral function could be ascribed to the CD8+ subset. This in vivo function was not restricted to sites in which intravenously infused lymphocytes usually are trapped or home in, such as the lungs or the spleen, respectively, but was also evident in the adrenal glands, a site to which antiviral effector cells have to specifically migrate. Specific infiltration of adrenal gland cortical tissue by donor-derived CD8+ memory T lymphocytes was demonstrated. CD4+ memory T lymphocytes had no antiviral effect by themselves and also were not required for the function of the CD8+ effector cells in this short-term immunotherapy model. These findings should help settle the debate about which subset of T lymphocytes comprises the effector cells that can directly control cytomegalovirus infection in the murine model system.     

Decrease of memory retention in a parasitic wasp: an effect of host manipulation by Wolbachia?

Several factors, such as cold exposure, aging, the number of experiences and viral infection, have been shown to affect learning ability in different organisms. Wolbachia has been found worldwide as an arthropod parasite/mutualist symbiont in a wide range of species, including insects. Differing effects have been identified on physiology and behavior by Wolbachia. However, the effect of Wolbachia infection on the learning ability of their host had never previously been studied. The current study carried out to compare learning ability and memory duration in 2 strains of the parasitoid Trichogramma brassicae: 1 uninfected and 1 infected by Wolbachia. Both strains were able to associate the novel odors with the reward of an oviposition into a host egg. However, the percentage of females that responded to the experimental design and displayed an ability to learn in these conditions was higher in the uninfected strain. Memory duration was longer in uninfected wasps (23.8 and 21.4 h after conditioning with peppermint and lemon, respectively) than in infected wasps (18.9 and 16.2 h after conditioning with peppermint and lemon, respectively). Memory retention increased in response to the number of conditioning sessions in both strains, but memory retention was always shorter in the infected wasps than in the uninfected ones. Wolbachia infection may select for reduced memory retention because shorter memory induces infected wasps to disperse in new environments and avoid competition with uninfected wasps by forgetting cues related to previously visited environments, thus increasing transmission of Wolbachia in new environments.     

Effects of rat cytomegalovirus on the nervous system of the early rat embryo

The purpose of the study was to investigate the impact of rat cytomegalovirus (RCMV) infection on the development of the nervous system in rat embryos, and to evaluate the involvement of Wnt signaling pathway key molecules and the downstream gene neurogenin 1 (Ngn1) in RCMV infected neural stem cells (NSCs). Infection and control groups were established, each containing 20 pregnant Wistar rats. Rats in the infection group were inoculated with RCMV by intraperitoneal injection on the first day of pregnancy. Rat E20 embryos were taken to evaluate the teratogenic rate. NSCs were isolated from E13 embryos, and maintained in vitro. We found: 1) Poor fetal development was found in the infection group with low survival and high malformation rates. 2) The proliferation and differentiation of NSCs were affected. In the infection group, NSCs proliferated more slowly and had a lower neurosphere formation rate than the control. The differentiation ratio from NSCs to neurons and glial cells was significantly different from that of the control, showed by immunofluorescence staining. 3) Ngn1 mRNA expression and the nuclear β-catenin protein level were significantly lower than the control on day 2 when NSCs differentiated. 4) The Morris water maze test was performed on 4-week pups, and the infected rats were found worse in learning and memory ability. In a summary, RCMV infection caused abnormalities in the rat embryonic nervous system, significantly inhibited NSC proliferation and differentiation, and inhibited the expression of key molecules in the Wnt/β-catenin signaling pathway so as to affect NSCs differentiation. This may be an important mechanism by which RCMV causes embryonic nervous system abnormalities.     

Cardamom (Elettaria cardamomum) perinatal exposure effects on the development,behavior and biochemical parameters in mice offspring

Cardamom is a strong antioxidant plant, so it is called the queen of spices. In the present study, we explored the potentials of cardamom on developmental, learning ability and biochemical parameters of mice offspring. Thirty pregnant mice were allocated to three groups of ten animals in each. Groups Π and Ш received pilsbury's Diet containing 10 and 20% of cardamom (w/w) respectively, whereas Group I used as control. Cardomom was administered from the first day of pregnancy and was continued until post-natal day 15 (PD 15) and thereafter the mothers were switched to plain pilsbury's Diet. During the weaning period, three pups in each litter were color marked from the others, and were subjected to various tests (Physical assessment such body weight and eye opening and hair appearance; the neuromaturation of reflexes like righting, rotating, and cliff avoidance reflexes; learning ability and memory retention; estimation of monoamines neurotransmitters like dopamine and serotonin, non-enzymatic oxidative stress such as TBARS and GSH in forebrain at different ages of pups). The results indicated that the body weight gain was declining significantly. Hair appearance and eyes opening were delayed significantly. Righting, rotating, and cliff avoidance reflexes were delayed in treated animals. Exposure to cardamom led to enhance learning and memory retention as compared to control. Monoamines (DA, 5-HT) and GSH were elevated, whereas TBARS was inhibited significantly. In conclusion, perinatal cardamom exposure enhanced learning and memory as compared to control. Cardamom and its benefit compounds were transported via placenta or/and milk during lactation. Cardamom needs more researches to investigate its benefits on other kinds of behavior.