United States Department of the Army

About: United States Department of the Army is a government organization based out in Arlington, Virginia, United States. It is known for research contribution in the topics: Poison control & Population. The organization has 32668 authors who have published 42453 publications receiving 947075 citations. The organization is also known as: DA & U.S. Department of the Army.

Anal cancers among HIV-infected persons: HAART is not slowing rising incidence.

Abstract: Objective— To evaluate the incidence rates of anal cancer over the HIV epidemic and assess theimpact of HAART use on anal cancer events. Methods— We evaluated the incidence of and factors associated with anal cancer usinglongitudinal data from the prospective U.S. Natural History Study (1985-2008). Poissonregression and Cox proportional hazard models were utilized. Correspondence: Dr. Nancy Crum-Cianflone, c/o Clinical Investigation Department (KCA), Naval Medical Center San Diego, 34800Bob Wilson Drive, Ste. 5, San Diego, CA 92134-1005. Phone: 619/532-8134/40; FAX: 619/532-8137; nancy.crum@med.navy.mil.The content of this publication is the sole responsibility of the authors and does not necessarily reflect the views or policies of the NIHor the Department of Health and Human Services, the DoD or the Departments of the Army, Navy or Air Force. Mention of tradenames, commercial products, or organizations does not imply endorsement by the U.S. Government.This work is original and has not been published elsewhere.Author Contributions: All authors have reviewed and approved this manuscript.Nancy Crum-Cianflone and Kathy Huppler Hullsiek had full access to all the data and take responsibility for the accuracy of the data.Study concept and design: Crum-CianfloneAcquisition of the data: Crum-Cianflone, Marconi, Ganesan, Weintrob, Barthel, AganAnalysis and interpretation of the data: Crum-Cianflone, Huppler Hullsiek, Marconi, Ganesan, Weintrob, Barthel, AganDrafting of the manuscript: Crum-Cianflone, Huppler HullsiekCritical review of the manuscript: Marconi, Ganesan, Weintrob, Barthel, AganStatistical analyses: Huppler HullsiekObtaining funding: Crum-Cianflone, AganAdministrative or technical support: Crum-Cianflone, Marconi, Ganesan, Weintrob, Barthel, AganStudy supervision: Crum-CianfloneThe IDCRP working group is comprised of: Susan Banks, Mary Bavaro MD, Helen Chun MD, Cathy Decker MD, Lynn Eberly PhD,Conner Eggleston, Heather Hairston, Cliff Hawkes MD, Arthur Johnson MD, Michael Landrum MD, Alan Lifson MD, Scott Merritt,Robert O'Connell MD, Jason Okulicz MD, Sheila Peel PhD, Michael Polis MD, John Powers MD, Edmund Tramont MD, TimothyWhitman MD, Glenn Wortmann MD, Michael Zapor MD.

Rhizosphere microbial populations in contaminated soils

Abstract: Rhizosphere microbial populations may increase bioremediation of soil contaminated with organic chemicals. A growth chamber study was conducted to evaluate rhizosphere microbial populations in contaminated and non-contaminated soil. Alfalfa (Medicago sativa L.) and alpine bluegrass (Poa alpina L.) were grown in soil containing a mixture of organic chemicals for 14 weeks. The equal millimolar mixture of hexadecane, (2,2-dimethyl-propyl)-benzene, cis-decahydronaphthalene (decalin), benzoic acid, phenanthrene, and pyrene was added at levels of 0 and 2000 mg/kg. Organic chemical degrader (OCD) populations were assessed by a Most-Probable-Number technique, and bacteria and fungi were enumerated by plate count methods. Different methods for expressing OCD rhizosphere populations were investigated to determine the effect it had on interpretation of the results. At 9 weeks, the OCD numbers were significantly higher in rhizosphere and contaminated soils than in bulk and non-contaminated soils, respectively. Alfalfa rhizosphere OCD levels were 4 × 107/g for contaminated and 6 × 106/g for non-contaminated soils. Bluegrass rhizosphere OCD levels were 1 × 107/g and 1 × 106/g in contaminated and non-contaminated soils, respectively. Selective enrichment of OCD populations was observed in contaminated rhizosphere soil. Higher numbers of OCD in contaminated rhizospheres suggest potential stimulation of bioremediation around plant roots.

Liquid crystallinity of natural silk secretions

Abstract: NATURAL silk exhibits a strength and stiffness similar to, and a toughness up to ten times greater than, that of artificial high-performance fibres1–5. These exceptional tensile properties, the optical birefringence of some silk secretions6–9 and the molecular order exhibited by some synthetic polypeptides in solution10 all suggest that natural silk secretions might form liquid-crystalline phases. We have now used polarized-light microscopy to study the secretions from major ampullae of spiders (Nephila clavipes) and from silk glands of silkworms (Bombyx mori). As the concentration is increased by evaporation of water, nematic liquid-crystalline microstructures develop. We deduce that natural silk secretions become liquid crystalline after leaving the gland but before solidifying into a fibre, thus promoting global molecular alignment in the fibre. Our hand-drawn fibres from droplets of secretion, as well as sheared thin films, show a banded microstructure which is indicative of a periodic variation in the direction of molecular alignment11. Both B. mori and N. clavipes, on the other hand, have apparently developed processing routes that ensure uniform molecular alignment: the threads and draglines, respectively, of these species do not show banded microstructures.

Ribavirin Causes Error Catastrophe during Hantaan Virus Replication

Abstract: Except for ribavirin, no other antiviral drugs for treating hantaviral diseases have been identified. It is well established that ribavirin will inhibit the production of infectious Hantaan virus (HTNV); however, its mechanism of action is unknown. To characterize the inhibitory effect of ribavirin on HTNV, the levels of viral RNAs, proteins, and infectious particles were measured for 3 days posttreatment of HTNV-infected Vero E6 cells. HTNV-infected cells treated with ribavirin showed a slight reduction in the levels of cRNA, viral RNA, and mRNA populations on the first day postinfection. The amount of cRNA and viral RNA increased to that observed for untreated HTNV-infected cells on day 2, whereas mRNA levels were more greatly reduced on days 2 and 3. Despite the finding of S-segment mRNA, albeit low, three of the viral proteins—nucleocapsid (N) protein and glycoproteins G1 and G2—could not be detected by immunohistochemistry in ribavirin-treated cells. To test the hypothesis that these effects were caused by incorporation of ribavirin into nascent RNA and a resultant “error catastrophe” was occurring, we cloned and sequenced the S-segment cRNA/mRNA from ribavirin-treated or untreated cells from day 3. We found a high mutation frequency (9.5/1,000 nucleotides) in viral RNA synthesized in the presence of ribavirin. Hence, the transcripts produced in the presence of the drug were not functional. These results suggest that ribavirin's mechanism of action lies in challenging the fidelity of the hantavirus polymerase, which causes error catastrophe.

Determinants of Inapparent and Symptomatic Dengue Infection in a Prospective Study of Primary School Children in Kamphaeng Phet, Thailand

Abstract: Background Dengue viruses are a major cause of morbidity in tropical and subtropical regions of the world. Inapparent dengue is an important component of the overall burden of dengue infection. It provides a source of infection for mosquito transmission during the course of an epidemic, yet by definition is undetected by health care providers. Previous studies of inapparent or subclinical infection have reported varying ratios of symptomatic to inapparent dengue infection. Methodology/Principal Findings In a prospective study of school children in Northern Thailand, we describe the spatial and temporal variation of the symptomatic to inapparent (S:I) dengue illness ratio. Our findings indicate that there is a wide fluctuation in this ratio between and among schools in a given year and within schools over several dengue seasons. The most important determinants of this S:I ratio for a given school were the incidence of dengue infection in a given year and the incidence of infection in the preceding year. We found no association between the S:I ratio and age in our population. Conclusions/Significance Our findings point to an important aspect of virus-host interactions at either a population or individual level possibly due to an effect of heterotypic cross-reactive immunity to reduce dengue disease severity. These findings have important implications for future dengue vaccines.