146 research outputs found
Fishermen as a Suitable Population for HIV Intervention Trials
Background. Suitable populations to sustain continued evaluation of HIV and sexually transmitted infection (STI) prevention interventions are required. We sought to determine whether fishermen are a suitable population for HIV intervention trials. Methods. In a cross-sectional descriptive survey, we selected 250 fishermen from proportional to size sampled boats. We collected socioeconomic and behavioral information, and specimens for HIV, herpes simplex virus (HSV-2), syphilis, gonorrhea, chlamydia and human papillomavirus (HPV) tests from consenting participants. Results. One third of the fishermen had concurrent sexual partnerships and two thirds were involved in transactional sex. About 70% were involved in extramarital sex with only one quarter using condoms in their three most recent sexual encounters. HIV prevalence was 26% and HSV-2 and HPV was 57%. Over 98% were willing to participate in a future HIV prevention clinical trial. Conclusion. Fishermen are a high-risk group for HIV/STI infections that may be suitable for HIV prevention trials. A cohort study would be useful to measure the incidence of HIV/STIs to ultimately determine the feasibility of enrolling this population in an HIV/STI prevention clinical trial
Population levels and geographical distribution of HIV RNA in rural Ugandan and Kenyan communities, including serodiscordant couples: a cross-sectional analysis.
BackgroundAs sub-Saharan Africa transitions to a new era of universal antiretroviral therapy (ART), up-to-date assessments of population-level HIV RNA suppression are needed to inform interventions to optimise ART delivery. We sought to measure population viral load metrics to assess viral suppression and characterise demographic groups and geographical locations with high-level detectable viraemia in east Africa.MethodsThe Sustainable East Africa Research in Community Health (SEARCH) study is a cluster-randomised controlled trial of an HIV test-and-treat strategy in 32 rural communities in Uganda and Kenya, selected on the basis of rural setting, having an approximate population of 10 000 people, and being within the catchment area of a President's Emergency Plan for AIDS Relief-supported HIV clinic. During the baseline population assessment in the SEARCH study, we did baseline HIV testing and HIV RNA measurement. We analysed stable adult (aged ≥15 years) community residents. We defined viral suppression as a viral load of less than 500 copies per mL. To assess geographical sources of transmission risk, we established the proportion of all adults (both HIV positive and HIV negative) with a detectable viral load (local prevalence of viraemia). We defined transmission risk hotspots as geopolitical subunits within communities with an at least 5% local prevalence of viraemia. We also assessed serodiscordant couples, measuring the proportion of HIV-positive partners with detectable viraemia. The SEARCH study is registered with ClinicalTrials.gov, number NCT01864603.FindingsBetween April 2, 2013, and June 8, 2014, of 303 461 stable residents, we enumerated 274 040 (90·3%), of whom 132 030 (48·2%) were adults. Of these, 117 711 (89·2%) had their HIV status established, of whom 11 964 (10·2%) were HIV positive. Of these, we measured viral load in 8828 (73·8%) people. Viral suppression occurred in 3427 (81·6%) of 4202 HIV-positive adults on ART and 4490 (50·9%) of 8828 HIV-positive adults. Regional viral suppression among HIV-positive adults occurred in 881 (48·2%) of 1827 people in west Uganda, 516 (45·0%) of 1147 in east Uganda, and 3093 (52·8%) of 5854 in Kenya. Transmission risk hotspots occurred in three of 21 parishes in west Uganda and none in east Uganda and in 24 of 26 Kenya geopolitical subunits. In Uganda, 492 (2·9%) of 16 874 couples were serodiscordant: in 287 (58·3%) of these couples, the HIV-positive partner was viraemic (and in 69 [14·0%], viral load was >100 000 copies per mL). In Kenya, 859 (10·0%) of 8616 couples were serodiscordant: in 445 (53·0%) of these couples, the HIV-positive partner was viraemic (and in 129 [15%], viral load was >100 000 copies per mL).InterpretationBefore the start of the SEARCH trial, 51% of east African HIV-positive adults had viral suppression, reflecting ART scale-up efforts to date. Geographical hotspots of potential HIV transmission risk and detectable viraemia among serodiscordant couples warrant intensified interventions.FundingNational Institute of Allergy and Infectious Diseases (National Institutes of Health) and the President's Emergency Plan for AIDS Relief
A superconducting tensor detector for mid-frequency gravitational waves: its multi-channel nature and main astrophysical targets
Mid-frequency band gravitational-wave detectors will be complementary for the
existing Earth-based detectors (sensitive above 10 Hz or so) and the future
space-based detectors such as LISA, which will be sensitive below around 10
mHz. A ground-based superconducting omnidirectional gravitational radiation
observatory (SOGRO) has recently been proposed along with several design
variations for the frequency band of 0.1 to 10 Hz. For three conceptual designs
of SOGRO (e.g., pSOGRO, SOGRO and aSOGRO), we examine their multi-channel
natures, sensitivities and science cases. One of the key characteristics of the
SOGRO concept is its six detection channels. The response functions of each
channel are calculated for all possible gravitational wave polarizations
including scalar and vector modes. Combining these response functions, we also
confirm the omnidirectional nature of SOGRO. Hence, even a single SOGRO
detector will be able to determine the position of a source and polarizations
of gravitational waves, if detected. Taking into account SOGRO's sensitivity
and technical requirements, two main targets are most plausible: gravitational
waves from compact binaries and stochastic backgrounds. Based on assumptions we
consider in this work, detection rates for intermediate-mass binary black holes
(in the mass range of hundreds up to ) are expected to be
. In order to detect stochastic gravitational
wave background, multiple detectors are required. Two aSOGRO detector networks
may be able to put limits on the stochastic background beyond the indirect
limit from cosmological observations.Comment: 35 pages, 8 figures, 4 table
Effect of oxidant stressors and phenolic antioxidants on the ochratoxigenic fungus Aspergillus carbonarius
28 pages, 4 figures.--Article first published online: 27 FEB 2015BACKGROUND:There are few studies dealing with the relationship between oxidative stress and ochratoxin A (OTA) biosynthesis. In this work, we analyzed the effect of the oxidant stressor menadione and the antioxidants 3,5-di-tert-butyl-4-hydroxytoluene (BHT), catechin, resveratrol and a polyphenolic extract on growth, generation of reactive oxygen species (ROS), OTA production and gene expression of antioxidant enzymes of Aspergillus carbonarius.
RESULTS:Exposure to menadione concentrations higher than 20 µmol L−1 led to increases in ROS and OTA levels and a decrease in growth rate. Exposure to 2.5–10 mmol L−1 BHT also led to higher ROS and OTA levels, although growth rate was only affected above 5 mmol L−1. Naturally occurring concentrations of catechin, resveratrol and polyphenolic extract barely affected growth rate, but they produced widely different effects on OTA production level depending on the antioxidant concentration used. In general, gene expression of antioxidant enzymes superoxide dismutase (SOD) and peroxiredoxin (PRX) was downregulated after exposure to oxidant and antioxidant concentrations that enhanced OTA production level.
CONCLUSION:Aspergillus carbonarius responds to oxidative stress, increasing OTA production. Nevertheless, the use of naturally occurring concentrations of antioxidant phenolic compounds to reduce oxidative stress is not a valid approach by itself for OTA contamination control in grapes.A Crespo-Sempere is the recipient of an FPI fellowship from the Spanish Government. This research was supported by grants AGL2005-00707 and AGL2008-04828-C03-02 from the Spanish Government.Peer reviewe
A Case of Non-Functioning Huge Adrenocortical Carcinoma Extending Into Inferior Vena Cava and Right Atrium
Primary adrenocortical carcinoma (ACC) is a rare tumor and its usual sites of metastasis are the lung (71%), lymph node (68%), liver (42%), and bone (26%). However, intracaval invasion extending into the right atrium is very rare and spontaneous regression of tumor burden in adrenal carcinoma is also rare. We report a case of ACC with direct invasion of the inferior vena cava and right atrium. A 34-yr-old male patient presented with progressive dyspnea, weight loss, and poor oral intake over 3 months. Non-functioning ACC with direct invasion of the inferior vena cava and right atrium was confirmed by imaging, pathologic, and hormonal study. Chemo-radio-therapy was attempted. However, tumor burden was not changed, but rather toxic hepatitis and thrombocytopenia were developed. His subjective symptoms and general conditions were improved after 1 month of conservative management and the patient was discharged. During clinical follow-up, this tumor showed spontaneous regression
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