248 research outputs found

    Comparison of antibodies that mediate HIV type 1 gp120 antibody-dependent cell-mediated cytotoxicity in asymptomatic HIV type 1-positive men and women

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    Recent studies suggest that HIV-specific antibody-dependent cell-mediated cytotoxicity (ADCC) antibodies contribute to protective immunity against HIV. An important characteristic of future HIV vaccines will, therefore, be the ability to stimulate production of these antibodies in both men and women. Early studies suggest that men may have a better ADCC antibody response against HIV than women. Our objective was to determine whether men and women differ with respect to their ADCC response to HIV-1 gp120. HIV-positive, asymptomatic untreated men and women were matched for race, age, CD4(+) T cell number, HIV-1 viral load, and treatment and HIV-1 gp120 ADCC antibody titers were compared. A standard (51)Cr-release assay was used to determine HIV-1 gp120 ADCC antibody titers in HIV-1-seropositive individuals from the Multicenter AIDS Cohort Study (MACS; n=32) and the Women's Interagency HIV Study (WIHS; n=32). Both sexes had high ADCC titers against HIV-1 gp120: 34.4% (n=11) and 40.6% (n=13) of men and women, respectively, had titers of 10,000; 62.5% (n=20) and 56.3% (n=18) had titers of 100,000. Groups did not differ in percent specific release (% SR), lytic units (LU), correlations of titer to viral load, or titer to CD4(+) T cells in men or women. Both groups also had similar cross-clade ADCC antibody responses (p>0.5 for % SR and LU). Comparable groups of asymptomatic HIV-1-infected men and women had comparable HIV-1 gp120 ADCC antibodies. Both sexes had significant cross-clade reactivity. Differences between men and women may become evident as disease progresses; this should be evaluated at later stages of HIV-1 infection

    The Rourke Baby Record Infant/Child Maintenance Guide: do doctors use it, do they find it useful, and does using it improve their well-baby visit records?

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    Background. The Rourke Baby Record (RBR) - http://www.rourkebabyrecord.ca - is a freely available evidence-based structured form for child health surveillance from zero to five years. Family physicians/general practitioners (FP/GPs) doing office based well-baby care in three Ontario Canada cities (London, Ottawa, and Toronto) were randomly sampled to study the prevalence and utility of the RBR and documentation of well-baby visits. Methods. Database with telephone confirmation was conducted to assess the prevalence of use of the RBR. Study Part 1: Questionnaire mailed to a random sample of 100 RBR users. Outcome measures were utility of, helpfulness of, and suggestions for the RBR. Descriptive analysis was employed. Study Part 2: Retrospective chart review of well-baby visits by 38 FP/GPs using student t-tests and factor analysis. Outcome measures were well-baby visit documentation of growth, nutrition, safety issues, developmental milestones, physical examination, and overall comprehensiveness. Results. The RBR was used by 78.5% (402/512) of successfully contacted FP/GPs who did well-baby care in these 3 cities. Study Part 1: Questionnaire respondents (N = 41/100) used the RBR in several ways, and found it most helpful for assessing healthy child development, charting/recording the visits, managing time effectively, addressing parent concerns, identifying health problems, and identifying high risk situations. The RBR was seen to be least helpful as a tool for managing or for referring identified health problems. Study Part 2: Charts from a total of 1,378 well-baby visits on 176 children were audited. Well-baby care provided by the 20 FP/GPs who used the RBR compared to that by the 18 non-users was statistically more likely to include documentation of type of feeding (p = 0.023), discussion of safety issues (p < 0.001), assessment of development (p = 0.001), and overall comprehensiveness (p < 0.001). Well-baby care provided by the RBR users compared to that by the non-users was not more likely to include documentation of measurement of growth (p = 0.097), or physical examination (p = 0.828). Conclusion. The RBR was widely used by FP/GPs in these settings. RBR users found it helpful for many purposes, and had a consistently high rate of documentation of many aspects of well-baby care. The Rourke Baby Record has become a de facto gold standard clinical practice tool in knowledge translation for pediatric preventive medicine and health surveillance for primary care pediatric providers

    Towards an understanding of the information and support needs of surgical adolescent idiopathic scoliosis patients: a qualitative analysis

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    <p>Abstract</p> <p>Background</p> <p>Informed decision making for adolescents and families considering surgery for scoliosis requires essential information, including expected outcomes with or without treatment and the associated risks and benefits of treatment. Ideally families should also receive support in response to their individual concerns. The aim of this study was to identify health-specific needs for online information and support for patients with adolescent idiopathic scoliosis who have had or anticipate having spinal surgery.</p> <p>Methods</p> <p>Focus group methodology was chosen as the primary method of data collection to encourage shared understandings, as well as permit expression of specific, individual views. Participants were considered eligible to participate if they had either experienced or were anticipating surgery for adolescent idiopathic scoliosis within 12 months, were between the ages of 10 and 18 years of age, and were English-speaking.</p> <p>Results</p> <p>Two focus groups consisting of 8 adolescents (1 male, 7 female) and subsequent individual interviews with 3 adolescents (1 male, 2 female) yielded a range of participant concerns, in order of prominence: (1) recovery at home; (2) recovery in hospital; (3) post-surgical appearance; (4) emotional impact of surgery and coping; (5) intrusion of surgery and recovery of daily activities; (6) impact of surgery on school, peer relationships and other social interactions; (7) decision-making about surgery; (8) being in the operating room and; (9) future worries.</p> <p>Conclusion</p> <p>In conclusion, adolescents welcomed the possibility of an accessible, youth-focused website with comprehensive and accurate information that would include the opportunity for health professional-moderated, online peer support.</p

    Acquired Type III Secretion System Determines Environmental Fitness of Epidemic Vibrio parahaemolyticus in the Interaction with Bacterivorous Protists

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    Genome analyses of marine microbial communities have revealed the widespread occurrence of genomic islands (GIs), many of which encode for protein secretion machineries described in the context of bacteria-eukaryote interactions. Yet experimental support for the specific roles of such GIs in aquatic community interactions remains scarce. Here, we test for the contribution of type III secretion systems (T3SS) to the environmental fitness of epidemic Vibrio parahaemolyticus. Comparisons of V. parahaemolyticus wild types and T3SS-defective mutants demonstrate that the T3SS encoded on genome island VPaI-7 (T3SS-2) promotes survival of V. parahaemolyticus in the interaction with diverse protist taxa. Enhanced persistence was found to be due to T3SS-2 mediated cytotoxicity and facultative parasitism of V. parahaemolyticus on coexisting protists. Growth in the presence of bacterivorous protists and the T3SS-2 genotype showed a strong correlation across environmental and clinical isolates of V. parahaemolyticus. Short-term microcosm experiments provide evidence that protistan hosts facilitate the invasion of T3SS-2 positive V. parahaemolyticus into a coastal plankton community, and that water temperature and productivity further promote enhanced survival of T3SS-2 positive V. parahaemolyticus. This study is the first to describe the fitness advantage of GI-encoded functions in a microbial food web, which may provide a mechanistic explanation for the global spread and the seasonal dynamics of V. parahaemolyticus pathotypes, including the pandemic serotype cluster O3:K6, in aquatic environments

    A Putative P-Type ATPase Required for Virulence and Resistance to Haem Toxicity in Listeria monocytogenes

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    Regulation of iron homeostasis in many pathogens is principally mediated by the ferric uptake regulator, Fur. Since acquisition of iron from the host is essential for the intracellular pathogen Listeria monocytogenes, we predicted the existence of Fur-regulated systems that support infection. We examined the contribution of nine Fur-regulated loci to the pathogenicity of L. monocytogenes in a murine model of infection. While mutating the majority of the genes failed to affect virulence, three mutants exhibited a significantly compromised virulence potential. Most striking was the role of the membrane protein we designate FrvA (Fur regulated virulence factor A; encoded by frvA [lmo0641]), which is absolutely required for the systemic phase of infection in mice and also for virulence in an alternative infection model, the Wax Moth Galleria mellonella. Further analysis of the ΔfrvA mutant revealed poor growth in iron deficient media and inhibition of growth by micromolar concentrations of haem or haemoglobin, a phenotype which may contribute to the attenuated growth of this mutant during infection. Uptake studies indicated that the ΔfrvA mutant is unaffected in the uptake of ferric citrate but demonstrates a significant increase in uptake of haem and haemin. The data suggest a potential role for FrvA as a haem exporter that functions, at least in part, to protect the cell against the potential toxicity of free haem

    Functional Integration of Grafted Neural Stem Cell-Derived Dopaminergic Neurons Monitored by Optogenetics in an In Vitro Parkinson Model

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    Intrastriatal grafts of stem cell-derived dopamine (DA) neurons induce behavioral recovery in animal models of Parkinson's disease (PD), but how they functionally integrate in host neural circuitries is poorly understood. Here, Wnt5a-overexpressing neural stem cells derived from embryonic ventral mesencephalon of tyrosine hydroxylase-GFP transgenic mice were expanded as neurospheres and transplanted into organotypic cultures of wild type mouse striatum. Differentiated GFP-labeled DA neurons in the grafts exhibited mature neuronal properties, including spontaneous firing of action potentials, presence of post-synaptic currents, and functional expression of DA D2 autoreceptors. These properties resembled those recorded from identical cells in acute slices of intrastriatal grafts in the 6-hydroxy-DA-induced mouse PD model and from DA neurons in intact substantia nigra. Optogenetic activation or inhibition of grafted cells and host neurons using channelrhodopsin-2 (ChR2) and halorhodopsin (NpHR), respectively, revealed complex, bi-directional synaptic interactions between grafted cells and host neurons and extensive synaptic connectivity within the graft. Our data demonstrate for the first time using optogenetics that ectopically grafted stem cell-derived DA neurons become functionally integrated in the DA-denervated striatum. Further optogenetic dissection of the synaptic wiring between grafted and host neurons will be crucial to clarify the cellular and synaptic mechanisms underlying behavioral recovery as well as adverse effects following stem cell-based DA cell replacement strategies in PD

    Suicide-related behaviors in older patients with new anti-epileptic drug use: data from the VA hospital system

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    <p>Abstract</p> <p>Background</p> <p>The U.S. Food and Drug Administration (FDA) recently linked antiepileptic drug (AED) exposure to suicide-related behaviors based on meta-analysis of randomized clinical trials. We examined the relationship between suicide-related behaviors and different AEDs in older veterans receiving new AED monotherapy from the Veterans Health Administration (VA), controlling for potential confounders.</p> <p>Methods</p> <p>VA and Medicare databases were used to identify veterans 66 years and older, who received a) care from the VA between 1999 and 2004, and b) an incident AED (monotherapy) prescription. Previously validated ICD-9-CM codes were used to identify suicidal ideation or behavior (suicide-related behaviors cases), epilepsy, and other conditions previously associated with suicide-related behaviors. Each case was matched to controls based on prior history of suicide-related behaviors, year of AED prescription, and epilepsy status.</p> <p>Results</p> <p>The strongest predictor of suicide-related behaviors (N = 64; Controls N = 768) based on conditional logistic regression analysis was affective disorder (depression, anxiety, or post-traumatic stress disorder (PTSD); Odds Ratio 4.42, 95% CI 2.30 to 8.49) diagnosed before AED treatment. Increased suicide-related behaviors were not associated with individual AEDs, including the most commonly prescribed AED in the US - phenytoin.</p> <p>Conclusion</p> <p>Our extensive diagnostic and treatment data demonstrated that the strongest predictor of suicide-related behaviors for older patients newly treated with AED monotherapy was a previous diagnosis of affective disorder. Additional, research using a larger sample is needed to clearly determine the risk of suicide-related behaviors among less commonly used AEDs.</p
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