Letter to the Editor

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153577/1/jddj002203372005693tb03917x.pd

The validity of self-rated health as a measure of health status among young military personnel: evidence from a cross-sectional survey

Abstract Background Single item questions about self ratings of overall health status are widely used in both military and civilian surveys. Limited information is available to date that examines what relationships exist between self-rated health, health status and health related behaviors among relatively young, healthy individuals. Methods The current study uses the population of active duty United States Air Force recruits (N = 31,108). Participants completed surveys that asked about health behaviors and health states and were rated their health on a continuum from poor to excellent. Results Ratings of health were consistently lower for those who used tobacco (F = 241.7, p < .001), reported binge drinking (F = 69.0, p < .001), reported drinking and driving (F = 19.4, p < .001), reported taking health risks (F = 109.4, p < .001), were depressed (F = 256.1, p < .001) and were overweight (F = 39.5, p < .001). Conclusion Given the consistent relationship between self-rated overall health and factors important to military health and fitness, self-rated health appears to be a valid measure of health status among young military troops.Peer Reviewe

Ultrastructural and functional fate of recycled vesicles in hippocampal synapses

Efficient recycling of synaptic vesicles is thought to be critical for sustained information transfer at central terminals. However, the specific contribution that retrieved vesicles make to future transmission events remains unclear. Here we exploit fluorescence and time-stamped electron microscopy to track the functional and positional fate of vesicles endocytosed after readily releasable pool (RRP) stimulation in rat hippocampal synapses. We show that most vesicles are recovered near the active zone but subsequently take up random positions in the cluster, without preferential bias for future use. These vesicles non-selectively queue, advancing towards the release site with further stimulation in an actin-dependent manner. Nonetheless, the small subset of vesicles retrieved recently in the stimulus train persist nearer the active zone and exhibit more privileged use in the next RRP. Our findings reveal heterogeneity in vesicle fate based on nanoscale position and timing rules, providing new insights into the origins of future pool constitution

Specific Loss of Histone H3 Lysine 9 Trimethylation and HP1γ/Cohesin Binding at D4Z4 Repeats Is Associated with Facioscapulohumeral Dystrophy (FSHD)

Facioscapulohumeral dystrophy (FSHD) is an autosomal dominant muscular dystrophy in which no mutation of pathogenic gene(s) has been identified. Instead, the disease is, in most cases, genetically linked to a contraction in the number of 3.3 kb D4Z4 repeats on chromosome 4q. How contraction of the 4qter D4Z4 repeats causes muscular dystrophy is not understood. In addition, a smaller group of FSHD cases are not associated with D4Z4 repeat contraction (termed “phenotypic” FSHD), and their etiology remains undefined. We carried out chromatin immunoprecipitation analysis using D4Z4–specific PCR primers to examine the D4Z4 chromatin structure in normal and patient cells as well as in small interfering RNA (siRNA)–treated cells. We found that SUV39H1–mediated H3K9 trimethylation at D4Z4 seen in normal cells is lost in FSHD. Furthermore, the loss of this histone modification occurs not only at the contracted 4q D4Z4 allele, but also at the genetically intact D4Z4 alleles on both chromosomes 4q and 10q, providing the first evidence that the genetic change (contraction) of one 4qD4Z4 allele spreads its effect to other genomic regions. Importantly, this epigenetic change was also observed in the phenotypic FSHD cases with no D4Z4 contraction, but not in other types of muscular dystrophies tested. We found that HP1γ and cohesin are co-recruited to D4Z4 in an H3K9me3–dependent and cell type–specific manner, which is disrupted in FSHD. The results indicate that cohesin plays an active role in HP1 recruitment and is involved in cell type–specific D4Z4 chromatin regulation. Taken together, we identified the loss of both histone H3K9 trimethylation and HP1γ/cohesin binding at D4Z4 to be a faithful marker for the FSHD phenotype. Based on these results, we propose a new model in which the epigenetic change initiated at 4q D4Z4 spreads its effect to other genomic regions, which compromises muscle-specific gene regulation leading to FSHD pathogenesis

Synapse Clusters Are Preferentially Formed by Synapses with Large Recycling Pool Sizes

Synapses are distributed heterogeneously in neural networks. The relationship between the spatial arrangement of synapses and an individual synapse's structural and functional features remains to be elucidated. Here, we examined the influence of the number of adjacent synapses on individual synaptic recycling pool sizes. When measuring the discharge of the styryl dye FM1–43 from electrically stimulated synapses in rat hippocampal tissue cultures, a strong positive correlation between the number of neighbouring synapses and recycling vesicle pool sizes was observed. Accordingly, vesicle-rich synapses were found to preferentially reside next to neighbours with large recycling pool sizes. Although these synapses with large recycling pool sizes were rare, they were densely arranged and thus exhibited a high amount of release per volume. To consolidate these findings, functional terminals were marked by live-cell antibody staining with anti-synaptotagmin-1-cypHer or overexpression of synaptopHluorin. Analysis of synapse distributions in these systems confirmed the results obtained with FM 1–43. Our findings support the idea that clustering of synapses with large recycling pool sizes is a distinct developmental feature of newly formed neural networks and may contribute to functional plasticity

Taxonomy based on science is necessary for global conservation

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GWAS meta-analysis of intrahepatic cholestasis of pregnancy implicates multiple hepatic genes and regulatory elements

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder affecting 0.5–2% of pregnancies. The majority of cases present in the third trimester with pruritus, elevated serum bile acids and abnormal serum liver tests. ICP is associated with an increased risk of adverse outcomes, including spontaneous preterm birth and stillbirth. Whilst rare mutations affecting hepatobiliary transporters contribute to the aetiology of ICP, the role of common genetic variation in ICP has not been systematically characterised to date. Here, we perform genome-wide association studies (GWAS) and meta-analyses for ICP across three studies including 1138 cases and 153,642 controls. Eleven loci achieve genome-wide significance and have been further investigated and fine-mapped using functional genomics approaches. Our results pinpoint common sequence variation in liver-enriched genes and liver-specific cis-regulatory elements as contributing mechanisms to ICP susceptibility

Attitudes and beliefs of adolescents and parents regarding adolescent suicide

OBJECTIVE: The goal was to understand the attitudes, beliefs, and perceptions of adolescents and parents of adolescents, from a variety of backgrounds, regarding adolescent suicide. METHODS: This qualitative study used focus groups to elicit the thoughts of distinct sociodemographic groups. A professional moderator guided the sessions by using a semistructured script. All groups were audiotaped. The transcripts and transcript summaries were analyzed for recurrent themes. The study was performed in community centers and schools in Chicago, Illinois (urban), and the Kansas City, Kansas, area (suburban and rural). A total of 66 adolescents (13-18 years of age) and 30 parents of adolescents participated in 13 focus groups. RESULTS: Both adolescents and parents recognized adolescent suicide as a major problem, but not for their own communities. All parent and adolescent groups identified many risk factors for suicide. Most adolescents reported drug and alcohol use as risk factors for suicide. However, parents often viewed drug and alcohol use as normal adolescent behavior. Both adolescent and parent groups suggested securing or removing guns if an adolescent was known to be suicidal. All participants requested information about adolescent suicide. CONCLUSIONS: Adolescents and parents need help understanding that suicide is an underidentified problem in their own communities. Both adolescents and parents are interested in learning more about how to identify and to intervene with a suicidal adolescent. Pediatricians are well positioned to provide this information in the office and in the community

Prediction of adult-onset smoking initiation among U.S. Air Force recruits using the Pierce Susceptibility Questionnaire

Background: At one time, it was expected that if an individual reached young adulthood without smoking, his/her risk for initiation was minimal. However, recent data suggest that smoking initiation among young adults may be increasing. One particularly vulnerable population of young adults for smoking initiation is military recruits. This study examined whether a modified version of the Pierce Susceptibility Questionnaire (PSQ) might be useful for identifying military recruits who are vulnerable for the initiation of tobacco use. Methods: Active duty recruits entering the U.S. Air Force over a 1-year period (n=31,107) were assessed upon entry into basic military training (BMT), and a subsample was also assessed at 12 months following training. Results: The modified PSQ predicted initiation of cigarette use for all categories of baseline smokers (never, experimenters, former smokers, and regular users). The likelihood of initiating smoking after BMT was substantially higher among those identified as susceptible than among those identified as not susceptible. Conclusions: It is likely that the PSQ would prove to be a valuable tool in attempts to reduce tobacco use in the military. The predictive abilities of the measure could be used to target intervention and prevention efforts towards those most at risk. © 2005 American Journal of Preventive Medicine