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Anita R. Bijoor S. Sudha T. Venkatesh 《Indian journal of clinical biochemistry : IJCB》2012,27(2):147-151
Lead is found in small but appreciable quantities in air, soil drinking water and food. Exposure to such amounts of lead does not cause acute lead toxicity, but produces subtle effects, particularly in children. The CDC advocates “safe” or “acceptable” levels of blood lead up to 10 μg/dl, while OSHA declares blood lead levels up to 40 μg/dl as “safe” or “acceptable” in the occupationally exposed. The objective of the study was to see if blood levels considered “safe” can cause changes in the biogenic neurotransmitters in the developing brain which may cause neurobehavioral defects like hyperactivity and other cognitive disorders. Albino Wistar rats were divided into the control and lead-treated groups. The control group was given unleaded water, while the lead-treated group was fed with 50 ppm lead acetate in drinking water. On day 45 the animals were subjected to a passive avoidance test, their blood analysed for ZPP and lead. They were then sacrificed and the neurotransmitters—Norepinephrine (NE) and its metabolite—methoxyhydroxyphenylglycol (MHPG) estimated in the brain areas associated with learning and memory—the frontal cortex, hippocampus and the striatum by HPLC-ECD. Our results showed significant increases in blood lead, NE and MHPG, while ZPP increase was insignificant. The rats showed neurobehavioral abnormalities as assessed by the passive avoidance test. We concluded that low blood levels of lead cannot be considered “safe” or “acceptable” as it causes neurotransmitter alterations. Increased NE turnover is implicated in hyperactivity disorders such as ADHD and Tourette syndrome. 相似文献
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Joanne S. Lehrer Hariclia H. Petrakos Vivek Venkatesh 《Early education and development》2014,25(3):295-317
Research Findings: This study explored the relationship between play and child development at the Grade 1 level. As previous research has noted a sudden curtailment of classroom play during this period, the relationship between play at home and children's school grades, behavior, and creativity scores was examined using correlational and regression analyses. In particular, this study sought to assess whether particular types of play (pretend play, active physical play, construction play, etc.) and social arrangements during play (play with siblings, with parents, alone, with friends) predicted any of the outcome measures. A total of 56 children ages 6 and 7 from suburban areas outside of Montreal, as well as their parents and teachers, participated in the study. Practice or Policy: Findings indicated that children spent between 1 and 2 hr playing after school each day and that the most common form of play was active physical play. The most common social arrangement during play was play with siblings. Children's free time in the morning and freedom to choose their play activities in the afternoon were predictive of children's academic progress. Watching others play and the ability to choose their own activities in the afternoon predicted positive adaptive behaviors at school. Play with commercial toys and playing alone were predictive of creativity scores. 相似文献
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Lead poisoning is well documented in persons occupationally exposed to lead. What is less known is, that even in persons working
in lead based industries, the effect of lead and the appearance of signs and symptoms of lead poisoning is genetically determined.
Three genes related to lead metabolism, exhibiting polymorphism have already been demonstrated-δALA-dehydratase, Vitamin D
receptor gene and Hemochromatosis gene. These alleles determine the susceptibility of the individuals to lead. We present
here a case of a lead acid battery worker, who presented without any signs and symptoms of lead poisoning except for a very
high level of blood lead (82.8μg/dl and 47.5μg/dl 9 months later) 相似文献
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A healthy civil society has long been held as vital to a healthy democracy and there is interest in whether the Internet affects this linkage. This paper explores the relationships between offline and online modes of associational life and also analyzes offline and online interactions with local governments in the US context. Based on our empirical analyses of 1,203 respondents, we show that online participation is not simply an extension of offline participation, but can be distinguished in important ways. First, we find that political and community-oriented engagements cluster separately from more private-regarding engagements. Second, participants of online democratic engagement are not characterized by the SES markers associated with offline democratic engagement who are older, have higher incomes, and have lived in the community longer. Finally, we find significant links between democratic engagement with the political system and involvement with political associations (but not social and community-oriented associations). 相似文献
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Recently, the model of adoption of technology in households (MATH) was developed and tested in the context of household personal computer (PC) adoption. In this study, we apply MATH to predict personal computer (PC) use. We conducted a nationwide survey including 370 households that owned at least one PC. Results indicate that attitudinal beliefs are extremely important in determining use of a PC in the household. In contrast to previous work examining adopters, normative and control beliefs were not significant in predicting use. Furthermore, several determinants of adoption that were important at different stages of the household life cycle were found nonsignificant in predicting use for the same stages of the household life cycle. Overall, the results demonstrate that the belief structure for household PC use is different from that of household PC adoption. Further, the results provide additional evidence regarding the importance of including household life cycle in studies of household technology adoption and use. 相似文献
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Herman Sunil D'Souza Geraldine Menezes T. Venkatesh 《Indian journal of clinical biochemistry : IJCB》2003,18(2):154-160
Heavy metals are important toxicants known to exert adverse effects in humans and animals, given sufficient exposure and accumulation
in the body. This has a great concern both at personal and public health risk. Heavy metals are also known to interact with
the essential trace minerals at the level of absorption and also during the metabolism. The adverse effects of the absorbed
and accumulated heavy metals include neurological, reproductive, renal and hematological systems. Children are more sensitive
than adults to the effects of lead. Efforts are made to understand the mechanism of the interactions of heavy metals with
essential trace minerals at the level of absorption. With available sensitive and specific methodologies like Anodic Stripping
Voltammetry for the evaluation of the levels of toxic heavy metals such as lead, cadmium, mercury etc., better understanding
of heavy metal absorption is made possible.
Due to the poor nutritional standards, risk of heavy metal exposure is still a major concern in developing countries. Studies
carried out by the author have provided evidence towards the understanding of the prevailing mechanisms of metal-metal interaction
at the intestinal level. During growth and development the demand for the essential minerals being at higher level, differentiation
of various essential metals and heavy metals pose an inherent problem due to certain common properties shared by them. With
this approach to the problem of heavy metal toxicity, it is preventable not only with environmental intervention but also
by the nutritional management. 相似文献
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Yan-Hong Zhang Vydianathan Ravi Geng Qin He Dai Hui-Xian Zhang Feng-Ming Han Xin Wang Yu-Hong Liu Jian-Ping Yin Liang-Min Huang Byrappa Venkatesh Qiang Lin 《国家科学评论(英文版)》2020,7(6):964
Syngnathids (seahorses, pipefishes and seadragons) exhibit an array of morphological innovations including loss of pelvic fins, a toothless tubular mouth and male pregnancy. They comprise two subfamilies: Syngnathinae and Nerophinae. Genomes of three Syngnathinae members have been analyzed previously. In this study, we have sequenced the genome of a Nerophinae member, the Manado pipefish (Microphis manadensis), which has a semi-enclosed brood pouch. Comparative genomic analysis revealed that the molecular evolutionary rate of the four syngnathids is higher than that of other teleosts. The loss of all but one P/Q-rich SCPP gene in the syngnathids suggests a role for the lost genes in dentin and enameloid formation in teleosts. Genome-wide comparison identified a set of 118 genes with parallel identical amino acid substitutions in syngnathids and placental mammals. Association of some of these genes with placental and embryonic development in mammals suggests a role for them in syngnathid pregnancy. 相似文献
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