Effect of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children

Objective: To investigate the influence of lead exposure on the immune function of lymphocytes and erythrocytes in preschool children. Materials and methods: A group of 217 children three to six years of age from a rural area were given a thorough physical examination and the concentration of lead in blood samples taken from each subject was determined. The indices of lymphocyte immunity (CD 3CD 4, CD 3CD 8, CD 4CD 8, CD-3CD 19) and erythrocyte immunity (RBC-C3b, RBC-IC, RFER, RFIR, CD35 and its average fluorescence intensity) of 40 children with blood lead levels above 0.483 μmol/L were measured and compared with a control group. Results: The blood lead levels of the 217 children ranged from 0.11 μmol/L to 2.11 μmol/L. The CD 3CD 4and CD 4CD 8 cells were lower (P＜0.01) and the CD 3CD 8 cells were higher in the lead-poisoned subjects than those in the control group (P＜0.05). CD 3 and CD-3CD 19 did not show significant differences. Although the RBC-C3b rosette forming rate was lower and the RBC-IC rosette forming rate was higher in the lead-poisoned group, this difference could not be shown to be statistically significant (P＞0.05). RFIR was found to be lower in the lead-poisoned group (P＜0.01). Compared with the control group, the positive rate of CD35 was not found to be significantly different in a group of 25 lead-poisoned children (P＞0.05), while the average fluorescence intensity was lower in the lead-poisoned group (P＜0.05). Conclusion: Lead exposure can result in impaired immune function of T lymphocytes and erythrocytes in preschool children.     

Non-occupational lead exposure and hypertension in Pakistani adults

INTRODUCTION Blood-Pb levels are taken as representative of dose/exposure, as all clinical symptoms resulting from the toxic effects of Pb are manifested mainly in blood. Lead exposure of children correlates with de- creased IQ, symptoms of hyper kinesis or minima brain dysfunction, poor learning, or defects in specific neuromotor tasks (Landgrin et al., 1980). Large number of observations over the years has associated lead exposure with human diseases (McMichael and Johnson, 1982). Ca…     

Study on the neurotoxic effects of low-level lead exposure in rats

Objective: To investigate effects of developmental lead exposure on nitric oxide synthase (NOS) activity in different brain regions and on N-methyl-D-aspartate (NMDA) receptor mRNA expression in the hippocampus of rats. On the basis of these observations, we explored possible mechanisms by which lead exposure leads to impaired learning and memorizing abilities in children. Methods: A series of rat animal models exposed to low levels of lead during the developing period was established (drinking water containing 0.025%, 0.05% and 0.075% lead acetate). NOS activities in the hippocampus, the cerebral cortex, the cerebellum and the brain stem were determined with fluorescence measurement and levels of mRNA expression of the NMDA receptor 2A (NR2A) subunit and NMDA receptor 2B (NR2B) subunit in the rat hippocampus were measured with Retro-translation (RT-PCR). Results: There were no differences in the body weight of rat pups between any of the groups at any given time (P>0.05). The blood lead level of Pb-exposed rat pups showed a systematic pattern of change: at 14 d of age, it was lower than that at 7 d of age, then rising to the peak level at 21 d and finally falling to lower levels at 28 d. The hippocampal NOS activities of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.01). NOS activities in the cerebellum of lead-exposed groups were all lower than that of the control group on the 21st and 28th day (P<0.001) and the NOS activity of the 0.025% group was significantly lower than that of the 0.05% and 0.075% groups on the 28th day (P<0.05). NOS activity in the cerebral cortex of the 0.075% group was significantly lower than that of the control, 0.025% and 0.05% groups on the four day spans (P<0.001). There was no significant difference of NOS activity in the brain stem between any lead-exposed group and the control group on the four day spans. In the 0.05% and the 0.075% groups, the level of NR2A mRNA expression was higher than that in the control group at 7 d and 14 d of age (P<0.05). In the 0.025% group, the level of NR2A was found to be higher than that in the control group at 7 d of age only (P<0.05). No significant differences were found for the levels of NR2B mRNA expression between any of the groups at any given time. Conclusions: NOS activity in the hippocampus, the cerebral cortex and the cerebellum are inhibited by lead exposure. The degree of the inhibitory effect depends on the time span of exposure and the lead concentration. Developmental low-level lead exposure was found to raise the level of NR2A mRNA expression in the hippocampus of rats. Developmental low-level lead exposure does not affect the level of NR2B mRNA expression in the hippocampus.     

3621名学龄前儿童血铅测定结果分析

[目的]了解儿童血铅水平及其影响因素。[方法]采用全血锌原卟啉值测定;问卷调查影响儿童血铅水平的相关因素,并进行多元逐步回归分析。[结果]3621名儿童平均血铅浓度为0.504umol/L。超过0.483umol/L共有1615人,占44.6％,多元逐步回归分析表明饭前不洗手、常玩金属或带油漆的玩具、使用含铅量高的学习和生活用具、常吃含铅量高食品、父母吸烟等因素与儿童血铅水平密切相关。[结论]儿童血铅含量水平与不良的生活习惯及生活环境的铅污染有关,应对影响儿童血铅水平的危险因素进行有效的预防。     

大豆异黄酮对鸭小肠黏膜内淋巴细胞分布的影响

本试验研究了大豆异黄酮对鸭小肠黏膜内淋巴细胞分布的影响。试验选用咔叽-康贝尔鸭200只,随机分成对照组和试验组。每组100只,对照组饲喂基础日粮,试验组在基础日粮中添加0.04%大豆异黄酮,试验期为40d。试验结束时从各组选择50只鸭进行屠杀,采集鸭的十二指肠、空肠、回肠组织样本,置于波氏固定液中固定。采用常规石蜡切片技术制作组织切片,应用OlympusCH-30显微摄影系统进行观察与拍照。结果表明,饲喂大豆异黄酮的试验组鸭小肠黏膜内淋巴细胞分布较对照组明显增多。说明大豆异黄酮能显著提高咔叽-康贝尔鸭小肠黏膜免疫功能。     

Conditional and indirect effects of age of first exposure on PTSD symptoms

Childhood violence exposure (CVE) in formative developmental years may have potent effects on severity and complexity of post-traumatic stress symptoms (PTSS) in adulthood, yet little research has examined the role of age of first exposure in the context of polyvictimization or gone beyond an examination of direct effects. The current study examines the specific associations between age of first exposure, total CVE, and posttraumatic stress symptoms in adulthood. Further, the conditional and indirect effects of age of first exposure on posttraumatic stress symptoms were examined. We hypothesized that age of first exposure to violence would be associated with higher total violence exposure across childhood, thereby predicting current posttraumatic stress symptom severity (i.e., indirect effect). We also postulated that age of first exposure would affect the relationship between total violence exposure and posttraumatic stress symptoms such that earlier exposure would exacerbate the effects of violence exposure (i.e., conditional effect). Participants included 269 violence-exposed adults recruited through MTurk; the mean age of first CVE was 6 years (SD = 3.29). Conditional process models indicated that age of first exposure was significantly associated with higher total childhood violence exposure, which in turn, was significantly associated with current posttraumatic stress symptoms in all domains. Further, a conditional effect of age of first exposure was present such that the relationship between total exposure to violence and symptoms of hyperarousal was stronger for those first exposed at earlier ages. Findings provide support suggesting the particular potency of early trauma on regulatory response systems.     

浅谈父亲在学前儿童心理发展中的角色和作用

父爱如山,在学前儿童的心理发展过程中,父亲扮演着重要的角色,如果缺少父亲的陪伴,将会对儿童的心理发育产生严重的影响。长期拥有父亲陪伴的儿童具有更加积极的性格,相反,如果长期没有父亲的陪伴,会在学前儿童的内心深处产生深刻的自卑心理,因此,父亲的作用是十分重要的,尤其是学前儿童正处在身心发育的关键性阶段,如果不能得到父亲的关怀与细心的呵护,将会对今后的人生产生严重的心理障碍。本文的论述重点就是针对父亲在学前儿童的成长过程中所扮演角色进行论述,并且分析父亲对儿童心理所具有的作用,希望通过本文的论述,能够为父母起到一定的警示性作用,为了孩子的健康成长,我们要重视起父亲的角色。     

贝类免疫机制研究概况

贝类免疫学是新兴学科无脊椎动物免疫学中的一个分支,近些年越来越受到学者们的关注．文章就贝类免疫防御体系的形成做一综述．贝类体内缺乏免疫球蛋白,其机体的细胞免疫主要依赖于血细胞的吞噬和包囊作用;而体液免疫是依靠血清中的一些非特异性的酶和调节因子来进行的,如溶酶体酶、酚氧化酶原激活系统、超氧化物歧化酶、抗菌肽、凝集素等．     

Phonological processing and emergent literacy in younger and older preschool children

Phonological awareness, phonological memory, and phonological access to lexical storage play important roles in acquiring literacy. We examined the convergent, discriminant, and predictive validity of these phonological processing abilities (PPA) in 389 3-, 4-, and 5-year-old children. Confirmatory factor analysis supported the validity of each PPA as separate from general cognitive ability and separate from each other. Multigroup structural equation modeling (SEM) with mean structure demonstrated that older preschoolers have better developed latent PPA than younger preschoolers but that the structure of PPA is equivalent. RAN was found uniquely associated with letter knowledge and text discrimination in younger preschoolers, and PA was found uniquely associated with word reading skills in older preschoolers. Finally, general cognitive ability was only indirectly associated with emergent literacy via PPA. These results highlight the importance of PPA in the early literacy development of English-speaking preschool children.     

The binding of MBL to common bacteria in infectious diseases of children

Objective:To purify Mannan-binding lectin(MBL)from human serum and detect its binding ability to several kindsof bacteria common in infections diseases of children.Methods:MBL was purifide from human serum by affinity chromatographyon mannan-Sepharose 4B column.Its binding ability to eight species,97 stratus of bacteria was detected by enzyme-linked lectinassay(ELLA).Results:MBL has different binding ability to bacteria and shows strong binding ability to Klebsiella ornithinolvticaand Escherichia coli,but shows relatively lower binding ability to Staphylococcus haemolyticus,Enterobacter cloacae andStaphylococcus epidermidis.To different isolates of Klebsiella pneumoniae,Haemophilus influenzae and Staphylococcus aureus,MBL shows quite different binding ability.Conclusions:MBL has different binding ability to different bacteria,and has relativelystronger binding ability to Gram-negative bacteria.Its binding ability to different isolates of certain kinds of bacteria is quitedifferent.     

An evaluation of the preschool PATHS curriculum on the development of preschool children

This study evaluated the efficacy of preschool Promoting Alternative Thinking Strategies (PATHS), an early years curriculum designed to improve children’s social and emotional competence, and reduce problem behaviour. Fifty-seven children aged three to four years took part in the study over one academic year. The control group (Group 1) received no preschool PATHS curriculum, Group 2 received an adapted version, and Group 3 received the full preschool PATHS curriculum. Relevant vocabulary and perspective-taking skills were assessed before and after the intervention alongside behavioural questionnaires completed by preschool staff and parents. Staff views were investigated. Group 3 significantly improved on some measures, but Groups 1 and 2 showed no significant improvements. Children who received the full version of the preschool PATHS curriculum exhibited less problem behaviour, showed better emotional knowledge, better attentional skills, and better prosocial behaviour. The contribution of the local Educational Psychology Service to the initiative is discussed.     

The contributions of parental management language to executive function in preschool children

This study investigated relations between preschoolers’ emergent executive function skills and their interactions with parents, with particular focus on the verbal utterances parents use to guide children's behavior (i.e., management language). Parent–child dyads (n = 127) were videotaped during a structured play task and the frequency of two types of management language, Direction (high control) and Suggestion (low control), was observed. Children's executive function was assessed using the Head–Toes–Knees–Shoulders (HTKS) task. Latent growth modeling was used to investigate relations between management language and the development of children's executive function. Direction language (i.e., commands) was negatively associated with children's age three executive function but not significantly related to the rate of executive function development over time. Conversely, Suggestion language (i.e., questions and statements that offer children some degree of choice) was positively related to executive function at age three but negatively related to growth. The potential importance of management language as a parenting behavior that contributes to various aspects of children's self-regulation during preschool and kindergarten is discussed.     

The impact of exposure to domestic violence on children and young people: a review of the literature

OBJECTIVE: This article reviews the literature concerning the impact of exposure to domestic violence on the health and developmental well-being of children and young people. Impact is explored across four separate yet inter-related domains (domestic violence exposure and child abuse; impact on parental capacity; impact on child and adolescent development; and exposure to additional adversities), with potential outcomes and key messages concerning best practice responses to children's needs highlighted. METHOD: A comprehensive search of identified databases was conducted within an 11-year framework (1995-2006). This yielded a vast literature which was selectively organized and analyzed according to the four domains identified above. RESULTS: This review finds that children and adolescents living with domestic violence are at increased risk of experiencing emotional, physical and sexual abuse, of developing emotional and behavioral problems and of increased exposure to the presence of other adversities in their lives. It also highlights a range of protective factors that can mitigate against this impact, in particular a strong relationship with and attachment to a caring adult, usually the mother. CONCLUSION: Children and young people may be significantly affected by living with domestic violence, and impact can endure even after measures have been taken to secure their safety. It also concludes that there is rarely a direct causal pathway leading to a particular outcome and that children are active in constructing their own social world. Implications for interventions suggest that timely, appropriate and individually tailored responses need to build on the resilient blocks in the child's life. PRACTICE IMPLICATIONS: This study illustrate the links between exposure to domestic violence, various forms of child abuse and other related adversities, concluding that such exposure may have a differential yet potentially deleterious impact for children and young people. From a resilient perspective this review also highlights range of protective factors that influence the extent of the impact of exposure and the subsequent outcomes for the child. This review advocates for a holistic and child-centered approach to service delivery, derived from an informed assessment, designed to capture a picture of the individual child's experience, and responsive to their individual needs.     

Short-term memory and working memory in children as a function of language-specific knowledge in English and Spanish

This study determined the degree to which the phonological and executive components of memory reflect language-specific capacities in Spanish and English vocabulary. We tested whether the memory processes in a sample of English language learners found in Grade 1 also emerged in Grade 2. For the total sample (N = 90), Grade 1 English STM measures shared a common construct with Spanish STM, whereas Grade 2 STM measures were language dependent. In contrast, WM measures were language independent across grades 1 and 2. When vocabulary subgroups were analyzed, a subgroup × type of memory task emerged. The results showed that performance on Spanish and English STM tasks were a function of high and low Spanish and English vocabulary knowledge, whereas WM was not. The relationship between language-specific processes in memory was discussed.     

Handwriting isolated cursive letters in young children: Effect of the visual trace deletion

This study assesses the handwriting of isolated cursive letters in five-year-old children and the effect of a modification in visual feedback. Sixty-four children copied twelve cursive letters with an inking pen and a non-inking pen. Reducing visual feedback decreased the mean number of penlifts, and increased mean velocity and fluency. However, it increased the size of the letters (trajectory length) and reduced their quality. We suggest that processing visual feedback of the emerging visual trace may interrupt the fluency of the movement, while writing without seeing the trace may place greater emphasis on motor control and the use of somatosensory feedback. This study supplies reflection about sensory feedback and the moment when it should be provided in handwriting instruction. Practitioners should be aware that variation in the writing environment (surface, tools …) modifies sensory feedback and affects handwriting learning (gesture and outcome) in different manner.     

音乐渗透对学前儿童智力开发的影响

相对于专门的音乐活动,渗透性音乐活动发挥着越来越重要的作用.结合心理学观点和学前儿童教育特点,设计相应的音乐渗透活动方案,通过这些活动,促进学前儿童智力因素的发展.     

Executive function performance and trauma exposure in a community sample of children

ObjectiveThough children exposed to familial violence are reported to have difficulties with a range of emotional and behavioral problems (e.g., lower school achievement) that implicate executive function (EF) deficits, relatively little research has specifically examined EF as a function of trauma exposure in children.MethodsBased on parent report of children's exposure to potentially traumatic events, children (N = 110; Age_Mean = 10.39) from an ethnically diverse community sample were compared across three trauma-exposure groups: familial trauma, non-familial trauma, and no trauma. Children completed a battery of tests to assess working memory, behavioral inhibition, processing speed, auditory attention, and interference control.ResultsFamilial trauma (relative to non-familial and no trauma exposure) was associated with poorer performance on an EF composite (composed of working memory, inhibition, auditory attention, and processing speed tasks); the effect size was medium. Both trauma-exposure status and dissociation symptoms explained unique variance in EF performance after controlling for anxiety symptoms, socio-economic status, and potential traumatic brain injury. While IQ and EF performance were related, SES predicted unique variance in IQ (and not EF) scores, while familial-trauma exposure did not.ConclusionsThe contribution of trauma exposure to basic executive functioning held after taking into account symptoms (anxiety and dissociation), socio-economic status, and possible traumatic brain injury exposure. EF problems may provide one route via which maltreated children become at risk for peer, academic, and behavior problems relative to their peers.Practice implicationsEF problems may provide one route via which maltreated children become at risk for peer, academic, psychological, and behavior problems relative to their peers. Recently, intervention strategies have emerged in the anxiety and mood disorder treatment literatures that appear to effectively target EFs. As future research continues to specify the relationship between child trauma exposure and EF performance, these innovative treatments may have important practice implications for addressing EF deficits.     

The impact of domestic violence exposure on South Asian children in the United States: Perspectives of domestic violence agency staff

The South Asian community is the fastest growing ethnic group in the United States, and past research suggests that South Asian domestic violence (DV) survivors may require culturally-specific resources. Similarly, South Asian children in the US exposed to DV may have unique responses and needs, but this has not been explored to date. The objective of this study was to examine the specific needs of South Asian children exposed to DV from the vantage point of staff from South Asian DV agencies across the United States. Thirty interviews were conducted, with data coded and consolidated into larger themes using thematic analysis. Participants described several factors important to understanding the impact of DV on South Asian children including the role of the extended family, identifying with two cultures, fear about what the South Asian community will think, gender differences, and the importance of projecting an image of perfection. Participants also discussed development of culturally-tailored resources. This study suggests the importance of framing South Asian children’s experiences within the context of interweaving South Asian and American cultural values, with careful attention paid to how potential culture clashes between parents and children may impact the way children process trauma. Further work should triangulate these themes with children, parents, and extended family, as well as collaborate with South Asian DV agencies to design child-focused programs.     

Internal and external influences on vocabulary development in preschool children

Competency in society's lingua franca plays a major role in the emergence of social disparities within education. Therefore, the present longitudinal study investigates vocabulary development and its predictors in preschool years. We focus on whether internal (phonological working memory) and external variables (preschool and home learning environment) have different impacts depending on parental native language. The study considers 547 children from 97 German preschools. Children's vocabulary was assessed at the ages of 3, 4, and 5 years. Latent growth curve models show that non-native German language children are characterized by reduced vocabulary at first assessment and lower progress compared to monolingual peers. Phonological working memory has a strong impact on all children's initial vocabulary but also on vocabulary growth in those whose parents speak German as an additional language. The effects of preschool and home learning environment are comparatively smaller.