988 research outputs found
Microscopy Quality Control in Médecins Sans Frontières Programs in Resource-Limited Settings
Derryck Klarkowski and Daniel Orozco describe the Médecins Sans Frontières program for monitoring the quality of microscopy for malaria, pulmonary tuberculosis, and leishmaniasis
Lymphocytic colitis presenting as difficult diarrhoea in an African woman: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Lymphocytic colitis is an uncommon intestinal disorder that presents with chronic diarrhoea. It is treatable, but in the developing world, its diagnosis may often prove difficult. Data and reports of this condition in Africa are scarce because most medical centres lack a functional gastrointestinal endoscopy unit that would aid in the diagnosis.</p> <p>Case presentation</p> <p>We present the case of a 53-year-old Nigerian woman with pathogen-negative chronic diarrhoea and a family history of chronic diarrhoea. She responded well to treatment after colonoscopy and colonic biopsy successfully diagnosed her illness.</p> <p>Conclusion</p> <p>Referral of patients with pathogen-negative chronic diarrhoea to medical centres that have facilities for colonoscopy and biopsy is important in the developing world.</p
Population Genomic Analysis of a Bacterial Plant Pathogen: Novel Insight into the Origin of Pierce's Disease of Grapevine in the U.S.
Invasive diseases present an increasing problem worldwide; however, genomic techniques are now available to investigate the timing and geographical origin of such introductions. We employed genomic techniques to demonstrate that the bacterial pathogen causing Pierce's disease of grapevine (PD) is not native to the US as previously assumed, but descended from a single genotype introduced from Central America. PD has posed a serious threat to the US wine industry ever since its first outbreak in Anaheim, California in the 1880s and continues to inhibit grape cultivation in a large area of the country. It is caused by infection of xylem vessels by the bacterium Xylella fastidiosa subsp. fastidiosa, a genetically distinct subspecies at least 15,000 years old. We present five independent kinds of evidence that strongly support our invasion hypothesis: 1) a genome-wide lack of genetic variability in X. fastidiosa subsp. fastidiosa found in the US, consistent with a recent common ancestor; 2) evidence for historical allopatry of the North American subspecies X. fastidiosa subsp. multiplex and X. fastidiosa subsp. fastidiosa; 3) evidence that X. fastidiosa subsp. fastidiosa evolved in a more tropical climate than X. fastidiosa subsp. multiplex; 4) much greater genetic variability in the proposed source population in Central America, variation within which the US genotypes are phylogenetically nested; and 5) the circumstantial evidence of importation of known hosts (coffee plants) from Central America directly into southern California just prior to the first known outbreak of the disease. The lack of genetic variation in X. fastidiosa subsp. fastidiosa in the US suggests that preventing additional introductions is important since new genetic variation may undermine PD control measures, or may lead to infection of other crop plants through the creation of novel genotypes via inter-subspecific recombination. In general, geographically mixing of previously isolated subspecies should be avoided
Splenic size after division of the short gastric vessels in Nissen fundoplication in children
Item does not contain fulltextPURPOSE: Nissen fundoplication is an effective treatment for gastro-esophageal reflux disease (GERD). Mobilization of the gastric fundus during fundoplication requires division of short gastric vessels of the spleen, which may cause splenic ischemia. The aim of this study was to determine if Nissen fundoplication results in hypotrophy of the spleen. METHODS: We performed pre-operative and post-operative ultrasound measurements of the spleen in children undergoing Nissen fundoplication. During operation, the surgeon estimated the compromised blood flow by assessment of the percentage of discoloration of the spleen. RESULTS: Twenty-four consecutive children were analyzed. Discoloration of the upper pole of the spleen was observed in 11 patients (48%) of a median estimated splenic surface of 20% (range 5-50%). The median ratio for pre-operative and post-operative length, width, and area of the spleen was 0.97, 1.03, and 0.96, respectively. The percentage of the estimated perfusion defect during surgery was not correlated with the ratios. In three patients, the area ratio was smaller than 0.8 (0.67-0.75), meaning that the area decreased with at least 20% after surgery. In none of these patients a discoloration was observed. CONCLUSION: Discoloration of the spleen after Nissen fundoplication is not associated with post-operative splenic atrophy.1 maart 201
Search for Kaluza-Klein Graviton Emission in Collisions at TeV using the Missing Energy Signature
We report on a search for direct Kaluza-Klein graviton production in a data
sample of 84 of \ppb collisions at = 1.8 TeV, recorded
by the Collider Detector at Fermilab. We investigate the final state of large
missing transverse energy and one or two high energy jets. We compare the data
with the predictions from a -dimensional Kaluza-Klein scenario in which
gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for
=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71
TeV, respectively.Comment: Submitted to PRL, 7 pages 4 figures/Revision includes 5 figure
Measurement of the average time-integrated mixing probability of b-flavored hadrons produced at the Tevatron
We have measured the number of like-sign (LS) and opposite-sign (OS) lepton
pairs arising from double semileptonic decays of and -hadrons,
pair-produced at the Fermilab Tevatron collider. The data samples were
collected with the Collider Detector at Fermilab (CDF) during the 1992-1995
collider run by triggering on the existence of and candidates
in an event. The observed ratio of LS to OS dileptons leads to a measurement of
the average time-integrated mixing probability of all produced -flavored
hadrons which decay weakly, (stat.)
(syst.), that is significantly larger than the world average .Comment: 47 pages, 10 figures, 15 tables Submitted to Phys. Rev.
Brugia malayi Microfilariae Induce a Regulatory Monocyte/Macrophage Phenotype That Suppresses Innate and Adaptive Immune Responses
Background Monocytes and macrophages contribute to the dysfunction of immune
responses in human filariasis. During patent infection monocytes encounter
microfilariae in the blood, an event that occurs in asymptomatically infected
filariasis patients that are immunologically hyporeactive. Aim To determine
whether blood microfilariae directly act on blood monocytes and in vitro
generated macrophages to induce a regulatory phenotype that interferes with
innate and adaptive responses. Methodology and principal findings Monocytes
and in vitro generated macrophages from filaria non-endemic normal donors were
stimulated in vitro with Brugia malayi microfilarial (Mf) lysate. We could
show that monocytes stimulated with Mf lysate develop a defined regulatory
phenotype, characterised by expression of the immunoregulatory markers IL-10
and PD-L1. Significantly, this regulatory phenotype was recapitulated in
monocytes from Wuchereria bancrofti asymptomatically infected patients but not
patients with pathology or endemic normals. Monocytes from non-endemic donors
stimulated with Mf lysate directly inhibited CD4+ T cell proliferation and
cytokine production (IFN-γ, IL-13 and IL-10). IFN-γ responses were restored by
neutralising IL-10 or PD-1. Furthermore, macrophages stimulated with Mf lysate
expressed high levels of IL-10 and had suppressed phagocytic abilities.
Finally Mf lysate applied during the differentiation of macrophages in vitro
interfered with macrophage abilities to respond to subsequent LPS stimulation
in a selective manner. Conclusions and significance Conclusively, our study
demonstrates that Mf lysate stimulation of monocytes from healthy donors in
vitro induces a regulatory phenotype, characterized by expression of PD-L1 and
IL-10. This phenotype is directly reflected in monocytes from filarial
patients with asymptomatic infection but not patients with pathology or
endemic normals. We suggest that suppression of T cell functions typically
seen in lymphatic filariasis is caused by microfilaria-modulated monocytes in
an IL-10-dependent manner. Together with suppression of macrophage innate
responses, this may contribute to the overall down-regulation of immune
responses observed in asymptomatically infected patients
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
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