118 research outputs found

    Comparison of David V valve-sparing root replacement and bioprosthetic valve conduit for aortic root aneurysm

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    ObjectiveValve sparing root replacement (VSRR) is an attractive option for the management of aortic root aneurysms with a normal native aortic valve. Therefore, we reviewed our experience with a modification of the David V VSRR and compared it with stented pericardial bioprosthetic valve conduit (BVC) root replacement in an age-matched cohort of older patients.MethodsA total of 48 VSRRs were performed at our institution, excluding those on bicuspid aortic valves. WeĀ compared these cases with 15 aortic root replacements performed using a BVC during the same period. Subgroup analysis was performed comparing 16 VSRR cases and 15 age-matched BVC cases.ResultsThe greatest disparity between the VSRR and BVC groups was age (53 vs 69 years, respectively; PĀ <Ā .0005). The matched patients were similar in terms of baseline demographics and differed only in concomitant coronary artery bypass grafting (2 VSRR vs 7 BVC patients; PĀ =Ā .036). None of the VSRR and 3 of the BVC procedures were performed for associated dissection (PĀ =Ā .101). Postoperative aortic insufficiency grade was significantly different between the 2 groups (PĀ =Ā .004). The cardiopulmonary bypass, crossclamp, and circulatory arrest times were not different between the VSRR and BVC groups (174 vs 187 minutes, PĀ =Ā .205; 128 vs 133 minutes, PĀ =Ā .376; and 10 vs 13 minutes, respectively; PĀ =Ā .175). No differences were found between the 2 groups with respect to postoperative complications. One postoperative death occurred in the BVC group and none in the VSRR group. The postoperative length of stay and aortic valve gradients were less in the VSRR group (6 vs 8 days, PĀ =Ā .038; 6 vs 11.4 mm Hg, PĀ =Ā .001). The intensive care unit length of stay was significantly less in the VSRR group (54 vs 110 hours, PĀ =Ā .001).ConclusionsVSRR is an effective alternative to the BVC for aortic root aneurysm

    S100A8 and S100A9 in experimental osteoarthritis

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    INTRODUCTION: The objective was to evaluate the changes in S100A8 S100A9, and their complex (S100A8/S100A9) in cartilage during the onset of osteoarthritis (OA) as opposed to inflammatory arthritis. METHODS: S100A8 and S100A9 protein localization were determined in antigen-induced inflammatory arthritis in mice, mouse femoral head cartilage explants stimulated with interleukin-1 (IL-1), and in surgically-induced OA in mice. Microarray expression profiling of all S100 proteins in cartilage was evaluated at different times after initiation of degradation in femoral head explant cultures stimulated with IL-1 and surgically-induced OA. The effect of S100A8, S100A9 or the complex on the expression of aggrecan (Acan), collagen II (Col2a1), disintegrin and metalloproteases with thrombospondin motifs (Adamts1, Adamts 4 &Adamts 5), matrix metalloproteases (Mmp1, Mmp3, Mmp13 &Mmp14) and tissue inhibitors of metalloproteinases (Timp1, Timp2 &Timp3), by primary adult ovine articular chondrocytes was determined using real time quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: Stimulation with IL-1 increased chondrocyte S100a8 and S100a9 mRNA and protein levels. There was increased chondrocyte mRNA expression of S100a8 and S100a9 in early but not late mouse OA. However, loss of the S100A8 staining in chondrocytes occurred as mouse OA progressed, in contrast to the positive reactivity for both S100A8 and S100A9 in chondrocytes in inflammatory arthritis in mice. Homodimeric S100A8 and S100A9, but not the heterodimeric complex, significantly upregulated chondrocyte Adamts1, Adamts4 and Adamts 5, Mmp1, Mmp3 and Mmp13 gene expression, while collagen II and aggrecan mRNAs were significantly decreased. CONCLUSIONS: Chondrocyte derived S100A8 and S100A9 may have a sustained role in cartilage degradation in inflammatory arthritis. In contrast, while these proteins may have a role in initiating early cartilage degradation in OA by upregulating MMPs and aggrecanases, their reduced expression in late stages of OA suggests they do not have an ongoing role in cartilage degradation in this non-inflammatory arthropathy

    Gattini 2010: Cutting Edge Science at the Bottom of the World

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    The high altitude Antarctic sites of Dome A and the South Pole offer intriguing locations for future large scale optical astronomical Observatories. The Gattini project was created to measure the optical sky brightness, large area cloud cover and aurora of the winter-time sky above such high altitude Antarctic sites. The Gattini-DomeA camera was installed on the PLATO instrument module as part of the Chinese-led traverse to the highest point on the Antarctic plateau in January 2008. This single automated wide field camera contains a suite of Bessel photometric filters (B, V, R) and a long-pass red filter for the detection and monitoring of OH emission. We have in hand one complete winter-time dataset (2009) from the camera that was recently returned in April 2010. The Gattini-South Pole UV camera is a wide-field optical camera that in 2011 will measure for the first time the UV properties of the winter-time sky above the South Pole dark sector. This unique dataset will consist of frequent images taken in both broadband U and B filters in addition to high resolution (R similar to 5000) long slit spectroscopy over a narrow bandwidth of the central field. The camera is a proof of concept for the 2m-class Antarctic Cosmic Web Imager telescope, a dedicated experiment to directly detect and map the redshifted lyman alpha fluorescence or Cosmic Web emission we believe possible due to the unique geographical qualities of the site. We present the current status of both projects

    What is a return to work after stroke?: 12 month work outcomes in a feasibility trial

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    Background: Return to work (RTW) is an outcome in determining the effectiveness of rehabilitation post-stroke. However, stroke survivors (SS) may return to different roles with altered work status. Income, hours, responsibilities and job-satisfaction may be reduced. SS may be dissatisfied if unable to resume apriori work status; alternatively adjusted work status may be viewed positively if perceived as a way of reducing the risk of another stroke. The purpose of this study was to explore what is meant by RTW. Method: Information about the nature of RTW (job type, hours, roles, responsibilities) was extracted from 3, 6 and 12 month follow-up postal questionnaires in 46 SS participants in a feasibility randomised controlled trial investigating effectiveness of a vocational rehabilitation intervention. Results/Findings: Participants took a mean 90 (SD:70, range 7-227) days to RTW. 19/46 reported working at 12 months. In 17 who supplied complete data, 7(41%) reported reduced working hours. Participants incurred a mean wage loss of 44% against pre-stroke earnings. 10/17(59%) participants were in the same job with the same employer and 6(35%) were working in different/modified jobs (1 missing:). 10/17(59%) had work-place adjustments. 18/46 (39%) participants were happy with their work situation. Discussion: Participants experienced marked changes in work status post-stroke, with implications for job-satisfaction, financial security and quality of life. Research into psychological adjustment following altered vocational status in SS is warranted. Conclusion: RTW is a complex outcome and may not translate to a return to pre-stroke vocational status. It is important to consider what constitutes a RTW following stroke

    Identification of the skeletal progenitor cells forming osteophytes in osteoarthritis.

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    OBJECTIVES: Osteophytes are highly prevalent in osteoarthritis (OA) and are associated with pain and functional disability. These pathological outgrowths of cartilage and bone typically form at the junction of articular cartilage, periosteum and synovium. The aim of this study was to identify the cells forming osteophytes in OA. METHODS: Fluorescent genetic cell-labelling and tracing mouse models were induced with tamoxifen to switch on reporter expression, as appropriate, followed by surgery to induce destabilisation of the medial meniscus. Contributions of fluorescently labelled cells to osteophytes after 2 or 8 weeks, and their molecular identity, were analysed by histology, immunofluorescence staining and RNA in situ hybridisation. PdgfrĪ±-H2BGFP mice and PdgfrĪ±-CreER mice crossed with multicolour Confetti reporter mice were used for identification and clonal tracing of mesenchymal progenitors. Mice carrying Col2-CreER, Nes-CreER, LepR-Cre, Grem1-CreER, Gdf5-Cre, Sox9-CreER or Prg4-CreER were crossed with tdTomato reporter mice to lineage-trace chondrocytes and stem/progenitor cell subpopulations. RESULTS: Articular chondrocytes, or skeletal stem cells identified by Nes, LepR or Grem1 expression, did not give rise to osteophytes. Instead, osteophytes derived from PdgfrĪ±-expressing stem/progenitor cells in periosteum and synovium that are descendants from the Gdf5-expressing embryonic joint interzone. Further, we show that Sox9-expressing progenitors in periosteum supplied hybrid skeletal cells to the early osteophyte, while Prg4-expressing progenitors from synovial lining contributed to cartilage capping the osteophyte, but not to bone. CONCLUSION: Our findings reveal distinct periosteal and synovial skeletal progenitors that cooperate to form osteophytes in OA. These cell populations could be targeted in disease modification for treatment of OA

    Four-class drug-resistant HIV-1 subtype C in a treatment experienced individual on dolutegravir-based antiretroviral therapy in Botswana.

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    : There are limited data on the effectiveness of dolutegravir (DTG)-based combination antiretroviral therapy (ART) in real-life settings in southern Africa where HIV-1 subtype C predominates. We report a patient infected with HIV-1 subtype C on DTG-based ART previously exposed to raltegravir who developed multidrug resistance mutations to four antiretroviral classes. There is need for drug resistance monitoring and clinical vigilance to ensure effectiveness of HIV treatment programs even in the era of DTG-based ART

    Diagnosis and prevalence of two new species of haplosporidians infecting shore crabs Carcinus maenas: Haplosporidium carcini n. sp., and H. cranc n. sp.

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    This study provides a morphological and phylogenetic characterization of two novel species of the order Haplosporida (Haplosporidium carcini n. sp., and H. cranc n. sp.) infecting the common shore crab Carcinus maenas collected at one location in Swansea Bay, South Wales, UK. Both parasites were observed in the haemolymph, gills and hepatopancreas. The prevalence of clinical infections (i.e. parasites seen directly in fresh haemolymph preparations) was low, at ~1%, whereas subclinical levels, detected by polymerase chain reaction, were slightly higher at ~2%. Although no spores were found in any of the infected crabs examined histologically (n = 334), the morphology of monokaryotic and dikaryotic unicellular stages of the parasites enabled differentiation between the two new species. Phylogenetic analyses of the new species based on the small subunit (SSU) rDNA gene placed H. cranc in a clade of otherwise uncharacterized environmental sequences from marine samples, and H. carcini in a clade with other crustacean-associated lineages

    Peripheral-Blood Stem Cells versus Bone Marrow from Unrelated Donors

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    BACKGROUND Randomized trials have shown that the transplantation of filgrastim-mobilized peripheral-blood stem cells from HLA-identical siblings accelerates engraftment but increases the risks of acute and chronic graft-versus-host disease (GVHD), as compared with the transplantation of bone marrow. Some studies have also shown that peripheral-blood stem cells are associated with a decreased rate of relapse and improved survival among recipients with high-risk leukemia. METHODS We conducted a phase 3, multicenter, randomized trial of transplantation of peripheral-blood stem cells versus bone marrow from unrelated donors to compare 2-year survival probabilities with the use of an intention-to-treat analysis. Between March 2004 and September 2009, we enrolled 551 patients at 48 centers. Patients were randomly assigned in a 1:1 ratio to peripheral-blood stem-cell or bone marrow transplantation, stratified according to transplantation center and disease risk. The median follow-up of surviving patients was 36 months (interquartile range, 30 to 37). RESULTS The overall survival rate at 2 years in the peripheral-blood group was 51% (95% confidence interval [CI], 45 to 57), as compared with 46% (95% CI, 40 to 52) in the bone marrow group (P=0.29), with an absolute difference of 5 percentage points (95% CI, āˆ’3 to 14). The overall incidence of graft failure in the peripheral-blood group was 3% (95% CI, 1 to 5), versus 9% (95% CI, 6 to 13) in the bone marrow group (P=0.002). The incidence of chronic GVHD at 2 years in the peripheral-blood group was 53% (95% CI, 45 to 61), as compared with 41% (95% CI, 34 to 48) in the bone marrow group (P=0.01). There were no significant between-group differences in the incidence of acute GVHD or relapse. CONCLUSIONS We did not detect significant survival differences between peripheral-blood stem-cell and bone marrow transplantation from unrelated donors. Exploratory analyses of secondary end points indicated that peripheral-blood stem cells may reduce the risk of graft failure, whereas bone marrow may reduce the risk of chronic GVHD. (Funded by the National Heart, Lung, and Blood Instituteā€“National Cancer Institute and others; ClinicalTrials.gov number, NCT00075816.

    Models of <i>KPTN</i>-related disorder implicate mTOR signalling in cognitive and overgrowth phenotypes

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    KPTN-related disorder is an autosomal recessive disorder associated with germline variants in KPTN (previously known as kaptin), a component of the mTOR regulatory complex KICSTOR. To gain further insights into the pathogenesis of KPTN-related disorder, we analysed mouse knockout and human stem cell KPTN loss-of-function models. Kptn -/- mice display many of the key KPTN-related disorder phenotypes, including brain overgrowth, behavioural abnormalities, and cognitive deficits. By assessment of affected individuals, we have identified widespread cognitive deficits (n = 6) and postnatal onset of brain overgrowth (n = 19). By analysing head size data from their parents (n = 24), we have identified a previously unrecognized KPTN dosage-sensitivity, resulting in increased head circumference in heterozygous carriers of pathogenic KPTN variants. Molecular and structural analysis of Kptn-/- mice revealed pathological changes, including differences in brain size, shape and cell numbers primarily due to abnormal postnatal brain development. Both the mouse and differentiated induced pluripotent stem cell models of the disorder display transcriptional and biochemical evidence for altered mTOR pathway signalling, supporting the role of KPTN in regulating mTORC1. By treatment in our KPTN mouse model, we found that the increased mTOR signalling downstream of KPTN is rapamycin sensitive, highlighting possible therapeutic avenues with currently available mTOR inhibitors. These findings place KPTN-related disorder in the broader group of mTORC1-related disorders affecting brain structure, cognitive function and network integrity.</p
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