75 research outputs found

    Evidence of ΄(1S)→J/ψ+χc1\Upsilon(1S) \to J/\psi+\chi_{c1} and search for double-charmonium production in ΄(1S)\Upsilon(1S) and ΄(2S)\Upsilon(2S) decays

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    Using data samples of 102×106102\times10^6 ΄(1S)\Upsilon(1S) and 158×106158\times10^6 ΄(2S)\Upsilon(2S) events collected with the Belle detector, a first experimental search has been made for double-charmonium production in the exclusive decays ΄(1S,2S)→J/ψ(ψâ€Č)+X\Upsilon(1S,2S)\rightarrow J/\psi(\psi')+X, where X=ηcX=\eta_c, χcJ(J= 0, 1, 2)\chi_{cJ} (J=~0,~1,~2), ηc(2S)\eta_c(2S), X(3940)X(3940), and X(4160)X(4160). No significant signal is observed in the spectra of the mass recoiling against the reconstructed J/ψJ/\psi or ψâ€Č\psi' except for the evidence of χc1\chi_{c1} production with a significance of 4.6σ4.6\sigma for ΄(1S)→J/ψ+χc1\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}. The measured branching fraction \BR(\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}) is (3.90±1.21(stat.)±0.23(syst.))×10−6(3.90\pm1.21(\rm stat.)\pm0.23 (\rm syst.))\times10^{-6}. The 90%90\% confidence level upper limits on the branching fractions of the other modes having a significance of less than 3σ3\sigma are determined. These results are consistent with theoretical calculations using the nonrelativistic QCD factorization approach.Comment: 12 pages, 4 figures, 1 table. The fit range was extended to include X(4160) signal according to referee's suggestions. Other results unchanged. Paper was accepted for publication as a regular article in Physical Review

    Genetic Characterization of Human T-Cell Lymphotropic Virus Type 1 in Mozambique: Transcontinental Lineages Drive the HTLV-1 Endemic

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    Human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of Adult T-Cell Leukemia/Lymphoma (ATL), the Tropical Spastic Paraparesis/HTLV-1-associated Myelopathy (TSP/HAM) and other inflammatory diseases, including dermatitis, uveitis, and myositis. It is estimated that 2–8% of the infected persons will develop a HTLV-1-associated disease during their lifetimes, frequently TSP/HAM. Thus far, there is not a specific treatment to this progressive and chronic disease. HTLV-1 has means of three transmission: (i) from mother to child during prolonged breastfeeding, (ii) between sexual partners and (iii) through blood transfusion. HTLV-1 has been characterized in 7 subtypes and the geographical distribution and the clinical impact of this infection is not well known, mainly in African population. HTLV-1 is endemic in sub-Saharan Africa. Mozambique is a country of southeastern Africa where TSP/HAM cases were reported. Recently, our group estimated the HTLV prevalence among Mozambican blood donors as 0.9%. In this work we performed a genetic analysis of HTLV-1 in blood donors and HIV/HTLV co-infected patients from Maputo, Mozambique. Our results showed the presence of three HTLV-1 clusters within the Cosmopolitan/Transcontinental subtype/subgroup. The differential rates of HIV-1/HTLV-1 co-infection in the three HTLV-1 clusters demonstrated the dynamic of the two viruses and the need for implementation of control measures focusing on both retroviruses

    Urothelial Plaque Formation in Post-Golgi Compartments

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    Urothelial plaques are specialized membrane domains in urothelial superficial (umbrella) cells, composed of highly ordered uroplakin particles. We investigated membrane compartments involved in the formation of urothelial plaques in mouse umbrella cells. The Golgi apparatus did not contain uroplakins organized into plaques. In the post-Golgi region, three distinct membrane compartments containing uroplakins were characterized: i) Small rounded vesicles, located close to the Golgi apparatus, were labelled weakly with anti-uroplakin antibodies and they possessed no plaques; we termed them “uroplakin-positive transporting vesicles” (UPTVs). ii) Spherical-to-flattened vesicles, termed “immature fusiform vesicles” (iFVs), were uroplakin-positive in their central regions and contained small urothelial plaques. iii) Flattened “mature fusiform vesicles” (mFVs) contained large plaques, which were densely labelled with anti-uroplakin antibodies. Endoytotic marker horseradish peroxidase was not found in these post-Golgi compartments. We propose a detailed model of de novo urothelial plaque formation in post-Golgi compartments: UPTVs carrying individual 16-nm particles detach from the Golgi apparatus and subsequently fuse into iFV. Concentration of 16-nm particles into plaques and removal of uroplakin-negative membranes takes place in iFVs. With additional fusions and buddings, iFVs mature into mFVs, each carrying two urothelial plaques toward the apical surface of the umbrella cell

    Co-infection by human immunodeficiency virus type 1 (HIV-1) and human T cell leukemia virus type 1 (HTLV-1): does immune activation lead to a faster progression to AIDS?

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    <p>Abstract</p> <p>Background</p> <p>Recent data have shown that HTLV-1 is prevalent among HIV positive patients in Mozambique, although the impact of HTLV-1 infection on HIV disease progression remains controversial. Our aim was to determine the phenotypic profile of T lymphocytes subsets among Mozambican patients co-infected by HIV and HTLV-1.</p> <p>Methods</p> <p>We enrolled 29 patients co-infected by HTLV-1 and HIV (co-infected), 59 patients mono-infected by HIV (HIV) and 16 healthy controls (HC), respectively.</p> <p>For phenotypic analysis, cells were stained with the following fluorochrome-labeled anti-human monoclonal antibodies CD4-APC, CD8-PerCP, CD25-PE, CD62L-FITC, CD45RA-FITC. CD45RO-PE, CD38-PE; being analysed by four-colour flow cytometry.</p> <p>Results</p> <p>We initially found that CD4<sup>+ </sup>T cell counts were significantly higher in co-infected, as compared to HIV groups. Moreover, CD4<sup>+ </sup>T Lymphocytes from co-infected patients presented significantly higher levels of CD45RO and CD25, but lower levels of CD45RA and CD62L, strongly indicating that CD4<sup>+ </sup>T cells are more activated under HTLV-1 plus HIV co-infection.</p> <p>Conclusion</p> <p>Our data indicate that HTLV-1/HIV co-infected patients progress with higher CD4<sup>+ </sup>T cell counts and higher levels of activation markers. In this context, it is conceivable that in co-infected individuals, these higher levels of activation may account for a faster progression to AIDS.</p

    Postoperative outcomes in oesophagectomy with trainee involvement

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    BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery

    Major Role of Microbes in Carbon Fluxes during Austral Winter in the Southern Drake Passage

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    Carbon cycling in Southern Ocean is a major issue in climate change, hence the need to understand the role of biota in the regulation of carbon fixation and cycling. Southern Ocean is a heterogeneous system, characterized by a strong seasonality, due to long dark winter. Yet, currently little is known about biogeochemical dynamics during this season, particularly in the deeper part of the ocean. We studied bacterial communities and processes in summer and winter cruises in the southern Drake Passage. Here we show that in winter, when the primary production is greatly reduced, Bacteria and Archaea become the major producers of biogenic particles, at the expense of dissolved organic carbon drawdown. Heterotrophic production and chemoautotrophic CO2 fixation rates were substantial, also in deep water, and bacterial populations were controlled by protists and viruses. A dynamic food web is also consistent with the observed temporal and spatial variations in archaeal and bacterial communities that might exploit various niches. Thus, Southern Ocean microbial loop may substantially maintain a wintertime food web and system respiration at the expense of summer produced DOC as well as regenerate nutrients and iron. Our findings have important implications for Southern Ocean ecosystem functioning and carbon cycle and its manipulation by iron enrichment to achieve net sequestration of atmospheric CO2

    Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

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    We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2

    Bacterioplankton drawdown of coral mass-spawned organic matter

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    Coral reef ecosystems are highly sensitive to microbial activities that result from dissolved organic matter (DOM) enrichment of their surrounding seawater. However, the response to particulate organic matter (POM) enrichment is less studied. In a microcosm experiment, we tested the response of bacterioplankton to a pulse of POM from the mass-spawning of Orbicella franksi coral off the Caribbean coast of Panama. Particulate organic carbon (POC), a proxy measurement for POM, increased by 40-fold in seawater samples collected during spawning; 68% degraded within 66 h. The elevation of multiple hydrolases presumably solubilized the spawn-derived POM into DOM. A carbon budget constructed for the 275 ”M of degraded POC showed negligible change to the concentration of dissolved organic carbon (DOC), indicating that the DOM was readily utilized. Fourier transform ion cyclotron resonance mass spectrometry shows that the DOM pool became enriched with heteroatom-containing molecules, a trend that suggests microbial alteration of organic matter. Our sensitivity analysis demonstrates that bacterial carbon demand could have accounted for a large proportion of the POC degradation. Further, using bromodeoxyuridine immunocapture in combination with 454 pyrosequencing of the 16S ribosomal RNA gene, we surmise that actively growing bacterial groups were the primary degraders. We conclude that coral gametes are highly labile to bacteria and that such large capacity for bacterial degradation and alteration of organic matter has implications for coral reef health and coastal marine biogeochemistry
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