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81.
Background
Thirteen percent of the U.S. population is ages 65 and older, a number projected to reach 20% by 2030. By 2015, 50% of Human Immunodeficiency Virus (HIV)-infected individuals in the U.S. are expected to be ages 50 and older. Current Centers for Disease Control and Prevention guidelines recommend “opt-out” HIV screening for individuals ages 13–64. The purpose of this study was to assess the occurrence and barriers to HIV screening in older adults, and to evaluate the rationale for expanding routine HIV screening to this population.Methods
The study used 2009 National Health Interview Survey (NHIS) data. A total of 12,366 (unweighted) adults, ages 50 and older, participated in the adult section of the NHIS and answered questions on the HIV/AIDS, Sexually Transmitted Diseases, and Tuberculosis components. Associations between HIV screening, socio-demographic variables, and knowledge of HIV-related disease were examined using logistic regression models.Results
The HIV screening rate within this population was 25.4%. Race had no statistically significant effect. Low risk perception of HIV exposure (84.1%) accounted for low likelihood of planned screening (3.5%) within 12 months post survey. A routine medical check-up was the single most common reason for HIV screening (37.6%), with only about half (52.7%) of the tests suggested by a health care provider.Conclusion
It is imperative that practices and policies are developed and implemented to increase HIV awareness and screening in the older adult population. Increased health care provider awareness of the importance of HIV screening, especially for those 65 and older, is critical. Health policies and clinical guidelines should be revised to promote and support screening of all adults. 相似文献82.
83.
Fox A Le NM Horby P van Doorn HR Nguyen VT Nguyen HH Nguyen TC Vu DP Nguyen MH Diep NT Bich VT Huong HT Taylor WR Farrar J Wertheim H Nguyen VK 《PloS one》2012,7(2):e31535
Background
It is unclear why the severity of influenza varies in healthy adults or why the burden of severe influenza shifts to young adults when pandemic strains emerge. One possibility is that cross-protective T cell responses wane in this age group in the absence of recent infection. We therefore compared the acute cellular immune response in previously healthy adults with severe versus mild pandemic H1N1 infection.Methods and Principal Findings
49 previously healthy adults admitted to the National Hospital of Tropical Diseases, Viet Nam with RT-PCR-confirmed 2009 H1N1 infection were prospectively enrolled. 39 recovered quickly whereas 10 developed severe symptoms requiring supplemental oxygen and prolonged hospitalization. Peripheral blood lymphocyte subset counts and activation (HLADR, CD38) and differentiation (CD27, CD28) marker expression were determined on days 0, 2, 5, 10, 14 and 28 by flow cytometry. NK, CD4 and CD8 lymphopenia developed in 100%, 90% and 60% of severe cases versus 13% (p<0.001), 28%, (p = 0.001) and 18% (p = 0.014) of mild cases. CD4 and NK counts normalized following recovery. B cell counts were not significantly associated with severity. CD8 activation peaked 6–8 days after mild influenza onset, when 13% (6–22%) were HLADR+CD38+, and was accompanied by a significant loss of resting/CD27+CD28+ cells without accumulation of CD27+CD28− or CD27−CD28− cells. In severe influenza CD8 activation peaked more than 9 days post-onset, and/or was excessive (30–90% HLADR+CD38+) in association with accumulation of CD27+CD28− cells and maintenance of CD8 counts.Conclusion
Severe influenza is associated with transient T and NK cell deficiency. CD8 phenotype changes during mild influenza are consistent with a rapidly resolving memory response whereas in severe influenza activation is either delayed or excessive, and partially differentiated cells accumulate within blood indicating that recruitment of effector cells to the lung could be impaired. 相似文献84.
Lo CM Samuelson LC Chambers JB King A Heiman J Jandacek RJ Sakai RR Benoit SC Raybould HE Woods SC Tso P 《American journal of physiology. Regulatory, integrative and comparative physiology》2008,294(3):R803-R810
CCK acts peripherally as a satiating peptide released during meals in response to lipid feeding and centrally functions in the modulation of feeding, exploratory, and memory activities. The present study determined metabolic parameters, food intake, anxiety-like behaviors, and cognitive function in mice lacking the CCK gene. We studied intestinal fat absorption, body composition, and food intake of CCK knockout (CCK-KO) mice by using the noninvasive measurement of intestinal fat absorption along with quantitative magnetic resonance (QMR) imaging and the DietMax system, respectively. Additionally, exploratory and memory capacities were assessed by monitoring running wheel activity and conducting elevated plus-maze and Morris water-maze tests with these mice. Compared with wild-type (WT) littermate controls, CCK-KO mice had normal food intake, fat absorption, body weight, and body mass. CCK-KO mice ate more food than control animals during the light period and less food during the dark period. Energy expenditure was unchanged between the genotypes; however, CCK-KO mice displayed greater fatty acid oxidation. CCK-KO mice were as active as WT animals in the running wheel test. CCK-KO mice spent more time in the closed arms of an elevated plus-maze, indicative of increased anxiety. Additionally, CCK-KO mice exhibited attenuated performance in a passive avoidance task and impaired spatial memory in the Morris water maze test. We conclude that CCK is involved in metabolic rate and is important for memory and exploration. CCK is intimately involved in multiple processes related to cognitive function and food intake regulation. 相似文献
85.
86.
Wertheim HF Walsh E Choudhurry R Melles DC Boelens HA Miajlovic H Verbrugh HA Foster T van Belkum A 《PLoS medicine》2008,5(1):e17
Background
Staphylococcus aureus permanently colonizes the vestibulum nasi of one-fifth of the human population, which is a risk factor for autoinfection. The precise mechanisms whereby S. aureus colonizes the nose are still unknown. The staphylococcal cell-wall protein clumping factor B (ClfB) promotes adhesion to squamous epithelial cells in vitro and might be a physiologically relevant colonization factor.Methods and Findings
We define the role of the staphylococcal cytokeratin-binding protein ClfB in the colonization process by artificial inoculation of human volunteers with a wild-type strain and its single locus ClfB knock-out mutant. The wild-type strain adhered to immobilized recombinant human cytokeratin 10 (CK10) in a dose-dependent manner, whereas the ClfB− mutant did not. The wild-type strain, when grown to the stationary phase in a poor growth medium, adhered better to CK10, than when the same strain was grown in a nutrient-rich environment. Nasal cultures show that the mutant strain is eliminated from the nares significantly faster than the wild-type strain, with a median of 3 ± 1 d versus 7 ± 4 d (p = 0.006). Furthermore, the wild-type strain was still present in the nares of 3/16 volunteers at the end of follow-up, and the mutant strain was not.Conclusions
The human colonization model, in combination with in vitro data, shows that the ClfB protein is a major determinant of nasal-persistent S. aureus carriage and is a candidate target molecule for decolonization strategies. 相似文献87.
Afforestation is a recommended practice to mitigate global warming. However, their implementation may generate undesirable impacts, mostly if exotic species are used. Plantations of Pinus radiata D Don in Ventania (Bs. As., Argentina) soils showed notorious increments of extractable P (Pe), which could affect the dynamic of this element as well as the degree of phosphorus saturation (GSPBray). The objectives of this study were: i) to quantify the GSPBray in Mollisols afforested with P. radiata comparing the results with those coming from adjacent, natural grassland areas (base line); ii) to evaluate the potential environmental risk induced by afforestation through the identification of a change point (PC) in the GSPBray indicative of a phosphate leaching increment. Treatments included mature stands of P. radiata (TB) and adjacent areas with natural grassland vegetation (TP). Samples were taken at 0-15; 15-30 and 30-45 cm soil depth, and texture, pH, total organic carbon (COT), Pe, soluble reactive phosphorus (PSR), phosphorus sorption index (ISP) and GSPBray were determined. The results showed a significant acidification in TB and an increase in the COT stock, indicating an additional atmospheric CO2 sequestration by the trees. The Pe and PSR values were notoriously higher in TB, and they were reflected in a significant increment in the GSPBray with respect to TP. The detection of a significant PC in the GSPBray-PSR regression indicates higher chances of phosphate leaching in the forest stands, which could reach water courses, lakes and artificial reservoirs promoting their eutrophication. Because of the potential environmental pollution risk of biologic origin derived from the afforestation with P. radiata in Mollisols areas, their inclusion in clean development practices must be reconsidered. 相似文献
88.
John-Paul Mutebi Heiman Wang Li Li Juliet E. Bryant Alan D. T. Barrett 《Journal of virology》2001,75(15):6999-7008
Previous studies with a limited number of strains have indicated that there are two genotypes of yellow fever (YF) virus in Africa, one in west Africa and the other in east and central Africa. We have examined the prM/M and a portion of the E protein for a panel of 38 wild strains of YF virus from Africa representing different countries and times of isolation. Examination of the strains revealed a more complex genetic relationship than previously reported. Overall, nucleotide substitutions varied from 0 to 25.8% and amino acid substitutions varied from 0 to 9.1%. Phylogenetic analysis using parsimony and neighbor-joining algorithms identified five distinct genotypes: central/east Africa, east Africa, Angola, west Africa I, and west Africa II. Extensive variation within genotypes was observed. Members of west African genotype II and central/east African genotype differed by 2.8% or less, while west Africa genotype I varied up to 6.8% at the nucleotide level. We speculate that the former two genotypes exist in enzootic transmission cycles, while the latter is genetically more heterogeneous due to regular human epidemics. The nucleotide sequence of the Angola genotype diverged from the others by 15.7 to 23.0% but only 0.4 to 5.6% at the amino acid level, suggesting that this genotype most likely diverged from a progenitor YF virus in east/central Africa many years ago, prior to the separation of the other east/central African strains analyzed in this study, and has evolved independently. These data demonstrate that there are multiple genotypes of YF virus in Africa and suggest independent evolution of YF virus in different areas of Africa. 相似文献
89.
Leptin is a hormone synthesized and secreted from adipose tissue. To study the physiologic effects of chronic leptin treatment, normal adult female Sprague-Dawley rats were injected subcutaneously for 35 days. Twice daily injections (250 microgram/day, b.i.d.) resulted in a significant (P<0.05) decrease in food intake that was maintained for 10 days before gradually returning to control level by day 21. Leptin decreased body weight by a maximum of 12% of the initial body weight on day 22 and remained reduced for the duration of the treatment. After 35 days of treatment, visible peritoneal adipose tissue was not detected. Body composition analysis showed that chronic injection of leptin resulted in a dramatic decrease in fat content (28+/-2 to 4+/-2 g, P<0.05; mean+/-SEM) while the lean content remained unchanged. Rats pair-fed to the leptin-treated group but treated with vehicle had the same body composition (23+/-3 g fat mass) as that measured for the ad libitum fed controls. Using indirect calorimetry we observed that leptin decreased respiratory quotient and thus increased fat oxidation. Leptin also prevented energy expenditure reduction typically associated with food restriction. Leptin treatment for 35 days decreased plasma triglyceride (0.75+/-0.07 to 0.30+/-0.03 mM, P<0.05), free fatty acid (0.56+/-0.06 to 0.32+/-0.04 mM) and insulin (3.2+/-0.5 to 1. 4+/-0.4 ng/ml, P<0.05) concentrations despite the fact that food intake was normalized by day 35. Withdrawal of leptin triggered hyperphagia indicating that leptin biology remained throughout the duration of the chronic treatment. These data suggest that leptin reduces fat mass by initially decreasing appetite and by maintaining enhanced fat utilization even when food intake has returned to that of vehicle-treated control. 相似文献
90.
Bruce A. Menge Francis Chan Sarah Dudas Dafne Eerkes-Medrano Kirsten Grorud-Colvert Kimberly Heiman Margot Hessing-Lewis Alison Iles Ruth Milston-Clements Mae Noble Kimberly Page-Albins Erin Richmond Gil Rilov Jeremy Rose Joe Tyburczy Luis Vinueza Phoebe Zarnetske 《Journal of experimental marine biology and ecology》2009,377(2):93-100
The search for generality in ecology should include assessing the influence of studies done in one system on those done in other systems. Assuming generality is reflected in citation patterns, we analyzed frequencies of terrestrial, marine, and freshwater citations in papers categorized as terrestrial, marine and freshwater in high-impact “general” ecological journals. Citation frequencies were strikingly asymmetric. Aquatic researchers cited terrestrial papers ~ 10 times more often than the reverse, implying uneven cross-fertilization of information between aquatic and terrestrial ecologists. Comparisons between citation frequencies in the early 1980s and the early 2000s for two of the seven journals yielded similar results. Summing across all journals, 60% of all research papers (n = 5824) published in these journals in 2002–2006 were terrestrial vs. 9% freshwater and 8% marine. Since total numbers of terrestrial and aquatic ecologists are more similar than these proportions suggest, the representation of publications by habitat in “general” ecological journals appears disproportional and unrepresentative of the ecological science community at large. Such asymmetries are a concern because (1) aquatic and terrestrial systems can be tightly integrated, (2) pressure for across-system understanding to meet the challenge of climate change is increasing, (3) citation asymmetry implies barriers to among-system flow of understanding, thus (4) impeding scientific and societal progress. Changing this imbalance likely depends on a bottom-up approach originating from the ecological community, through pressure on societies, journals, editors and reviewers. 相似文献