1,137 research outputs found

    Cloning and characterization of a conjugal Tcr element from bacteroides

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    Thesis (B.S.) in Microbiology -- University of Illinois at Urbana-Champaign, 1988.Bibliography: leaves 15-18.Microfiche of typescript. [Urbana, Ill.]: Photographic Services, University of Illinois, U of I Library, [1988]. 1 microfiche (39 frames): negative

    Polyclonal Infections Due to Mycobacterium Avium Complex in Patients with AIDS Detected by Pulsed-field Gel Electrophoresis of Sequential Clinical Isolates.

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    Invasive infection with organisms of the Mycobacterium avium complex (MAC) is common among patients with advanced human immunodeficiency virus infection. In previous studies, we analyzed multiple individual colonies of MAC isolated from specimens obtained at the same time and observed that 14 to 20% of patients are simultaneously infected with more than one strain. In this study, we examined sequential isolates from 12 patients with AIDS who had two or more MAC isolates available from clinical specimens collected more than 1 week apart; the intervals between the first and last specimens ranged from 8 to 192 (median, 46) days. For each isolate, restriction digests of genomic DNA were analyzed by pulsed-field gel electrophoresis; DNA was prepared by using a protocol, described here in detail, which had been optimized for conditions of bacterial growth and lysis. The pulsed-field gel electrophoresis analysis identified four patients (33%) infected with two different MAC strains. Both M. avium and M. intracellulare were cultured from blood specimens from two patients. In each of the four patients, the second strain was identified from a culture taken within 14 days of the initial study isolate, and in three of these patients, the first strain was detected again in a subsequent culture. These observations suggest that the presence of two different strains among isolates from sequential cultures may reflect ongoing polyclonal infection. We conclude that polyclonal infection with MAC is common among patients with AIDS. The identification of such infections may be critical in the development of effective treatments

    Reproductive Failure in UK Harbour Porpoises Phocoena phocoena : Legacy of Pollutant Exposure?

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    This research was supported by a Marie Curie International Outgoing Fellowship within the Seventh European Community Framework Programme (Project Cetacean-stressors, PIOF-GA-2010-276145 to PDJ and SM). Additional funding was provided through the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS) (Grants SSFA/2008 and SSFA / ASCOBANS / 2010 / 5 to SM). Analysis of Scottish reproductive and teeth samples was funded by the EC-funded BIOCET project (BIOaccumulation of persistent organic pollutants in small CETaceans in European waters: transport pathways and impact on reproduction, grant EVK3-2000-00027 to GJP), and Marine Scotland (GJP). Samples examined in this research were collected under the collaborative Cetacean Strandings Investigation Programme (http://ukstrandings.org/), which is funded by the Department for Environment, Food and Rural Affairs (Defra) and the UK’s Devolved Administrations in Scotland and Wales (http://sciencesearch.defra.gov.uk/Defaul​t.aspx?Menu=Menu&Module=More&Location=No​ne&Completed=0&ProjectID=15331) (grants to PDJ, RD). UK Defra also funded the chemical analysis under a service-level agreement with the Centre for Environment, Fisheries and Aquaculture Science (grants to RJL, JB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Transport and Use of a Centaur Second Stage in Space

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    As nations continue to explore space, the desire to reduce costs will continue to grow. As a method of cost reduction, transporting and/or use of launch system components as integral components of missions may become more commonplace in the future. There have been numerous scenarios written for using launch vehicle components (primarily space shuttle used external tanks) as part of flight missions or future habitats. Future studies for possible uses of launch vehicle upper stages might include asteroid diverter using gravity orbital perturbation, orbiting station component, raw material at an outpost, and kinetic impactor. The LCROSS (Lunar CRater Observation and Sensing Satellite) mission was conceived as a low-cost means of determining whether water exists at the polar regions of the moon. Manifested as a secondary payload with the LRO (Lunar Reconnaissance Orbiter) spacecraft aboard an Atlas V launch vehicle, LCROSS guided its spent Centaur Earth Departure Upper Stage (EDUS) into the lunar crater Cabeu's, as a kinetic impactor. This paper describes some of the challenges that the LCROSS project encountered in planning, designing, launching with and carrying the Centaur upper stage to the moon

    Queen Conch (Strombus gigas) Testis Regresses during the Reproductive Season at Nearshore Sites in the Florida Keys

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    BACKGROUND: Queen conch (Strombus gigas) reproduction is inhibited in nearshore areas of the Florida Keys, relative to the offshore environment where conchs reproduce successfully. Nearshore reproductive failure is possibly a result of exposure to environmental factors, including heavy metals, which are likely to accumulate close to shore. Metals such as Cu and Zn are detrimental to reproduction in many mollusks. METHODOLOGY/PRINCIPAL FINDINGS: Histology shows gonadal atrophy in nearshore conchs as compared to reproductively healthy offshore conchs. In order to determine molecular mechanisms leading to tissue changes and reproductive failure, a microarray was developed. A normalized cDNA library for queen conch was constructed and sequenced using the 454 Life Sciences GS-FLX pyrosequencer, producing 27,723 assembled contigs and 7,740 annotated transcript sequences. The resulting sequences were used to design the microarray. Microarray analysis of conch testis indicated differential regulation of 255 genes (p<0.01) in nearshore conch, relative to offshore. Changes in expression for three of four transcripts of interest were confirmed using real-time reverse transcription polymerase chain reaction. Gene Ontology enrichment analysis indicated changes in biological processes: respiratory chain (GO:0015992), spermatogenesis (GO:0007283), small GTPase-mediated signal transduction (GO:0007264), and others. Inductively coupled plasma-mass spectrometry analysis indicated that Zn and possibly Cu were elevated in some nearshore conch tissues. CONCLUSIONS/SIGNIFICANCE: Congruence between testis histology and microarray data suggests that nearshore conch testes regress during the reproductive season, while offshore conch testes develop normally. Possible mechanisms underlying the testis regression observed in queen conch in the nearshore Florida Keys include a disruption of small GTPase (Ras)-mediated signaling in testis development. Additionally, elevated tissue levels of Cu (34.77 ng/mg in testis) and Zn (831.85 ng/mg in digestive gland, 83.96 ng/mg in testis) nearshore are similar to reported levels resulting in reproductive inhibition in other gastropods, indicating that these metals possibly contribute to NS conch reproductive failure

    Flight Operations for the LCROSS Lunar Impactor Mission

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    The LCROSS (Lunar CRater Observation and Sensing Satellite) mission was conceived as a low-cost means of determining the nature of hydrogen concentrated at the polar regions of the moon. Co-manifested for launch with LRO (Lunar Reconnaissance Orbiter), LCROSS guided its spent Centaur upper stage into the Cabeus crater as a kinetic impactor, and observed the impact flash and resulting debris plume for signs of water and other compounds from a Shepherding Spacecraft. Led by NASA Ames Research Center, LCROSS flight operations spanned 112 days, from June 18 through October 9, 2009. This paper summarizes the experiences from the LCROSS flight, highlights the challenges faced during the mission, and examines the reasons for its ultimate success

    Evolving coral reef conservation with genetic information

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    Targeted conservation and management programs are crucial for mitigating anthropogenic threats to declining biodiversity. Although evolutionary processes underpin extant patterns of biodiversity, it is uncommon for resource managers to explicitly consider genetic data in conservation prioritization. Genetic information is inherently relevant to management because it describes genetic diversity, population connectedness, and evolutionary history; thereby typifying their behavioral traits, physiological climate tolerance, evolutionary potential, and dispersal ability. Incorporating genetic information into spatial conservation prioritization starts with reconciling the terminology and techniques used in genetics and conservation science. Genetic data vary widely in analyses and their interpretations can be challenging even for experienced geneticists. Therefore, identifying objectives, decision rules, and implementations in decision support tools specifically for management using genetic data is challenging. Here, we outline a framework for eight genetic system characteristics, their measurement, and how they could be incorporated in spatial conservation prioritization for two contrasting objectives: biodiversity preservation vs maintaining ecological function and sustainable use. We illustrate this framework with an example using data from Tridacna crocea (Lamarck, 1819) (boring giant clam) in the Coral Triangle. We find that many reefs highlighted as conservation priorities with genetic data based on genetic subregions, genetic diversity, genetic distinctness, and connectivity are not prioritized using standard practices. Moreover, different characteristics calculated from the same samples resulted in different spatial conservation priorities. Our results highlight that omitting genetic information from conservation decisions may fail to adequately represent processes regulating biodiversity, but that conservation objectives related to the choice of genetic system characteristics require careful consideration

    Identification and characterization of a spontaneous ovarian carcinoma in Lewis rats

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    <p>Abstract</p> <p>Background</p> <p>Ovarian carcinoma is the fourth most common cause of death from cancer in women. Limited progress has been made toward improving the survival rate of patients with this disease in part because of the lack of a good animal model. We present here a model of spontaneous ovarian carcinoma arising in a normal Lewis rat.</p> <p>Methods</p> <p>A spontaneously occurring tumor of the left ovary was found in a normal Lewis rat during necropsy, which was sectioned for histological examination and placed into single cell suspension. Tumor cells were passaged <it>in vivo </it>by intraperitoneal injection into immunocompetent Lewis rats, and <it>in vitro </it>culture resulted in generation of a cell line. Tumor cells were examined by flow cytometry for expression of estrogen receptor α, progesterone receptor, androgen receptor, her-2/neu, epithelial cell adhesion molecule, and CA125. β-catenin expression and cellular localization was assessed by immunocytochemistry. RNA was harvested for gene expression profiling and studying the expression of cytokines.</p> <p>Results</p> <p>The tumor, designated FNAR, could be serially transplanted into Lewis rats and propagated as a cell line <it>in vitro</it>, maintaining the properties of the original tumor. The FNAR cells displayed striking morphologic similarities to human ovarian carcinoma, resembling the endometrioid carcinoma subtype of surface epithelial neoplasms. The cells expressed estrogen receptor α, progesterone receptor, androgen receptor, her-2/neu, epithelial cell adhesion molecule, CA125, and nuclear β-catenin. A gene expression profile showed upregulation of a number of genes that are also upregulated in human ovarian carcinoma.</p> <p>Conclusion</p> <p>This reliable model of ovarian carcinoma should be helpful in better understanding the biology of the disease as well as the development of novel treatment strategies.</p

    Perinatal Bisphenol A Exposure in C57B6/129svj Male Mice: Potential Altered Cytokine/Chemokine Production in Adulthood

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    Pregnant mice (n = 3) were exposed to BPA by intraperitoneal injection, from gestation day 9.5 until end of lactation. Male offspring were evaluated for cytokine production at 20 wk-of-age. One pregnant control mouse produced no males, precluding statistical analysis. However, recurring shifts in cytokines were suggested in the adult BPA offspring. Serum showed a numeric increase in 16 of 21 basal cytokine levels. ConA-stimulated splenocytes showed a numeric increase in 17 of 21 cytokines, and LPS-stimulated splenocytes an increase in 18 of 21 cytokines. The cytokine profile was one of TH1 up-regulation more than TH2, and with skewing toward TH17 responses
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