Correlation between high risk obesity groups and low socioeconomic status in school children

OBJECTIVE: Obesity is a major health problem among children and adolescents which is potentially affected by socioeconomic status (SES). The high risk group (HRG) comprises those youths with a body mass index (BMI) between the 85th and 95th percentile (at risk for overweight) and > or = 95th percentile (overweight). We sought a potential link between the HRG and SES. METHODS: Public schools in Chesterfield County, Virginia measured BMI among students in kindergarten and third, seventh, and tenth grades. We assessed SES based on eligibility for the National School Lunch Program and the percentage of the school-age population living in poverty based on per capita income from the 2000 Census. RESULTS: From 28 to 38% of children and adolescents were in the high risk group. Low SES had robust and highly significant correlations with HRG status with r-values ranging from 0.565 to 0.842, P < 0.0001. CONCLUSIONS: Low SES appears to be an important factor in childhood and adolescent obesity.     

Structural elucidation of the m157 mouse cytomegalovirus ligand for Ly49 natural killer cell receptors

Natural killer (NK) cells express activating and inhibitory receptors that, in concert, survey cells for proper expression of cell surface major histocompatibility complex (MHC) class I molecules. The mouse cytomegalovirus encodes an MHC-like protein, m157, which is the only known viral antigen to date capable of engaging both activating (Ly49H) and inhibitory (Ly49I) NK cell receptors. We have determined the 3D structure of m157 and studied its biochemical and cellular interactions with the Ly49H and Ly49I receptors. m157 has a characteristic MHC-fold, yet possesses several unique structural features not found in other MHC class I-like molecules. m157 does not bind peptides or other small ligands, nor does it associate with beta(2)-microglobulin. Instead, m157 engages in extensive intra- and intermolecular interactions within and between its domains to generate a compact minimal MHC-like molecule. m157's binding affinity for Ly49I (K(d) approximately 0.2 microM) is significantly higher than that of classical inhibitory Ly49-MHC interactions. Analysis of viral escape mutations on m157 that render it resistant to NK killing reveals that it is likely to be recognized by Ly49H in a binding mode that differs from Ly49/MHC-I. In addition, Ly49H+ NK cells can efficiently lyse RMA cells expressing m157, despite the presence of native MHC class I. Collectively, our results show that m157 represents a structurally divergent form of MHC class I-like proteins that directly engage Ly49 receptors with appreciable affinity in a noncanonical fashion.     

Natural killer cells in NOD.NK1.1 mice acquire cytolytic function during viral infection and provide protection against cytomegalovirus

Resting natural killer (NK) cells in nonobese diabetic (NOD) mice have impaired immune functions compared with NK cells from other mouse strains. Here we investigated how NOD NK cells respond after mouse cytomegalovirus (MCMV) infection, using NOD mice congenic for the protective NK gene complex from C57BL/6 mice. Compared with C57BL/6 mice congenic for the H2 gene complex from NOD mice (B6.g7), NOD.NK1.1 mice fail to control early infection with MCMV. After MCMV infection, however, NOD.NK1.1 NK cells demonstrate increased cytolytic function, associated with higher expression of granzyme B, and undergo robust expansion. One week after infection, NOD.NK1.1 NK cells control MCMV replication as effectively as B6.g7 NK cells, even in the absence of T cells and B cells. Thus, the impaired cytotoxic function of NK cells in NOD mice is alleviated by viral infection, which enables NOD NK cells to efficiently control MCMV infection.     

A Chemical Biology Approach to Myocardial Regeneration

Heart failure is one of the major causes of death in the Western world because cardiac muscle loss is largely irreversible and can lead to a relentless decline in cardiac function. Novel therapies are needed since the only therapy to effectively replace lost myocytes today is transplantation of the entire heart. The advent of embryonic and induced pluripotent stem cell (ESC/iPSC) technologies offers the unprecedented possibility of devising cell replacement therapies for numerous degenerative disorders. Not only are ESCs and iPSCs a plausible source of cardiomyocytes in vitro for transplantation, they are also useful tools to elucidate the biology of stem cells that reside in the adult heart and define signaling molecules that might enhance the limited regenerative capability of the adult human heart. Here, we review the extracellular factors that control stem cell cardiomyogenesis and describe new approaches that combine embryology with stem cell biology to discover drug-like small molecules that stimulate cardiogenesis and potentially contribute to the development of pharmaceutical strategies for heart muscle regeneration.     

An update on diastolic dysfunction

Diastolic dysfunction refers to abnormal diastolic filling properties of the left ventricle regardless of whether systolic function is normal or the patient has symptoms. Diastolic heart failure (HF), or more accurately, HF with preserved systolic function, is a distinct clinical entity characterized by the presence of the triad of impaired diastolic function, normal systolic function (left ventricular ejection fraction > 50%), and symptoms of HF. Patients with HF with preserved systolic function are frequently symptomatic from both acute and chronic elevations in left ventricular end-diastolic pressure and/or left atrial pressure.     

Tim-3 marks human natural killer cell maturation and suppresses cell-mediated cytotoxicity

Natural killer (NK) cells are innate lymphocytes that play an important role against viral infections and cancer. This effect is achieved through a complex mosaic of inhibitory and activating receptors expressed by NK cells that ultimately determine the magnitude of the NK-cell response. The T-cell immunoglobulin- and mucin domain-containing (Tim)-3 receptor was initially identified as a T-helper 1-specific type I membrane protein involved in regulating T-cell responses. Human NK cells transcribe the highest amounts of Tim-3 among lymphocytes. Tim-3 protein is expressed on essentially all mature CD56(dim)CD16(+) NK cells and is expressed heterogeneously in the immature CD56(bright)CD16(-) NK-cell subset in blood from healthy adults and in cord blood. Tim-3 expression was induced on CD56(bright)CD16(-) NK cells after stimulation with IL-15 or IL-12 and IL-18 in vitro, suggesting that Tim-3 is a maturation marker on NK cells. Whereas Tim-3 has been used to identify dysfunctional T cells, NK cells expressing high amounts of Tim-3 are fully responsive with respect to cytokine production and cytotoxicity. However, when Tim-3 was cross-linked with antibodies it suppressed NK cell-mediated cytotoxicity. These findings suggest that NK-cell responses may be negatively regulated when NK cells encounter target cells expressing cognate ligands of Tim-3.     

A Toolbox for Herpesvirus miRNA Research: Construction of a Complete Set of KSHV miRNA Deletion Mutants

Kaposi’s sarcoma-associated herpesvirus (KSHV) encodes 12 viral microRNAs (miRNAs) that are expressed during latency. Research into KSHV miRNA function has suffered from a lack of genetic systems to study viral miRNA mutations in the context of the viral genome. We used the Escherichia coli Red recombination system together with a new bacmid background, BAC16, to create mutants for all known KSHV miRNAs. The specific miRNA deletions or mutations and the integrity of the bacmids have been strictly quality controlled using PCR, restriction digestion, and sequencing. In addition, stable viral producer cell lines based on iSLK cells have been created for wildtype KSHV, for 12 individual miRNA knock-out mutants (ΔmiR-K12-1 through -12), and for mutants deleted for 10 of 12 (ΔmiR-cluster) or all 12 miRNAs (ΔmiR-all). NGS, in combination with SureSelect technology, was employed to sequence the entire latent genome within all producer cell lines. qPCR assays were used to verify the expression of the remaining viral miRNAs in a subset of mutants. Induction of the lytic cycle leads to efficient production of progeny viruses that have been used to infect endothelial cells. Wt BAC16 and miR mutant iSLK producer cell lines are now available to the research community.     

新疆护理专职教师工作压力现状及影响因素

目的探讨新疆护理教师工作压力现状并分析其影响因素,为提出护理教师队伍建设的相关对策提供实证依据并为护理院校管理和教师人才队伍的可持续发展提出建议。方法采用高职教师工作压力量表对新疆15个地、市、州抽取的10所护理院校在编在岗的256位护理教师进行问卷调查,调查其工作压力现状并分析其影响因素。结果护理专职教师的工作压力得分为（2．436±0．576）分,大于2分,说明教师的工作压力大。教龄、婚姻、兼职情况及教学工作量不同的教师因社会因素而产生的工作压力水平不同,不同婚姻状况的教师因学校管理及制度因素产生的压力水平不同,性别、年龄、学历、婚姻、教学工作量不同的教师个人职业发展所带来的压力水平不同,性别、教龄、每周课时量等在护理院校教师工作压力不同;年龄、婚姻状况、教学工作量不同的教师因人际关系产生的工作压力水平不同,性别、年龄、教龄、职称、婚姻、教学工作量、收入水平及兼职情况不同的教师因工作负荷压力水平不同,性别、职称、婚姻、教学工作量、担任教学课程不同的教师因个人特质因素带来的工作压力不同,差异均有统计学意义（P〈0．05）。结论护理专职教师的工作压力大,来源是多方面的,学校管理制度和社会因素带来的压力最大,因此应尽快改变社会各界对护理教育认识上的不足和偏见,明确护理教育的定位,加大国家对护理教育的投入,同时护理教师应提高对自己职业的认识,合理制定自己的职业生涯发展规划。     

The effects of transient hyperglycemia on brain glucose in rats anesthetized with halothane

The effects of transient hyperglycemia on brain glucose and the relationship between blood and brain glucose were studied in 76 Sprague-Dawley rats anesthetized with halothane 1% inspired. In a common control group, blood and brain glucose were determined prior to any intervention (n = 10). A second group of 30 rats was given an iv infusion of 3.9 ml of saline over a 30-min period, and blood and brain glucose were subsequently determined at several time points: 30 min (immediately after the saline infusion), 45, 60, 90, or 120 min (n = 6 for each time point). A third group of 36 rats was administered 3 g/kg of glucose in 3.9 ml of iv saline over a similar 30-min period, and blood and brain glucose were measured at the same time periods as in saline-treated rats and also when half of the glucose infusion was given (time = 15 min; n = 6 for each time point). In the common control group, blood glucose was 114 +/- 14 mg/dl (6.4 +/- 0.8 mumol/ml; mean +/- SD) and brain glucose was 2.41 +/- 0.59 mumol/g. Saline infusion had no effect on brain or blood glucose. In contrast, glucose infusion in the study group produced significant increases in both blood and brain glucose, achieving maximal values of 488 +/- 60 mg/dl (27.4 +/- 3.4 mumol/ml) and 7.62 +/- 0.52 mumol/g, respectively, at the 30-min measurement period. The ratio of brain to blood glucose, normalized so that the common control group data achieved a value of 1, was less than unity during the period of glucose infusion. This ratio reached a nadir of 0.75 +/- 0.07 at the 30-min measurement period (P less than 0.05 versus saline infusion). Thereafter, with the cessation of glucose infusion, the ratio returned to 1 and eventually exceeded unity: the peak ratios were 1.23 +/- 0.13 and 1.16 +/- 0.21 at the 60- and 90-min period, respectively (P less than 0.05 versus saline treatment). The authors concluded that during periods of rapidly fluctuating blood glucose, there is a hysteresis between blood and brain glucose values; hence, it may not be possible to accurately estimate brain glucose by measuring blood glucose.