300 research outputs found

    Chapter 1: Introduction to the Methods Guide for Medical Test Reviews

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    Evaluation of medical tests presents challenges distinct from those involved in the evaluation of therapies; in particular, the very great importance of context and the dearth of comprehensive RCTs aimed at comparing the clinical outcomes of different tests and test strategies. Available guidance provides some suggestions: 1) Use of the PICOTS typology for clarifying the context relevant to the review, and 2) use of an organizing framework for classifying the types of medical test evaluation studies and their relationship to potential key questions. However, there is a diversity of recommendations for reviewers of medical tests and a proliferation of concepts, terms, and methods. As a contribution to the field, this Methods Guide for Medical Test Reviews seeks to provide practical guidance for achieving the goals of clarity, consistency, tractability, and usefulness

    The native architecture of a photosynthetic membrane

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    In photosynthesis, the harvesting of solar energy and its subsequent conversion into a stable charge separation are dependent upon an interconnected macromolecular network of membrane-associated chlorophyll–protein complexes. Although the detailed structure of each complex has been determined, the size and organization of this network are unknown. Here we show the use of atomic force microscopy to directly reveal a native bacterial photosynthetic membrane. This first view of any multi-component membrane shows the relative positions and associations of the photosynthetic complexes and reveals crucial new features of the organization of the network: we found that the membrane is divided into specialized domains each with a different network organization and in which one type of complex predominates. Two types of organization were found for the peripheral light-harvesting LH2 complex. In the first, groups of 10–20 molecules of LH2 form light-capture domains that interconnect linear arrays of dimers of core reaction centre (RC)–light-harvesting 1 (RC–LH1–PufX) complexes; in the second they were found outside these arrays in larger clusters. The LH1 complex is ideally positioned to function as an energy collection hub, temporarily storing it before transfer to the RC where photochemistry occurs: the elegant economy of the photosynthetic membrane is demonstrated by the close packing of these linear arrays, which are often only separated by narrow 'energy conduits' of LH2 just two or three complexes wide

    Successful treatment of bilateral open calcaneal fractures with concomitant lower extremity injuries: A case report

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    Open calcaneal fractures are high morbidity injuries and the risk of complications depends on the concomitant injuries, on the size and the position of the traumatic wound. A 53-year-old male patient with bilateral open calcaneal fractures and associated concomitant lower extremity injuries such as subtalar dislocation, talonavicular dislocation and open distal tibial metaphyseal fracture was immediately operated by percutaneous Kirschner wire fixation combined with external fixators. He was able to walk with full weight bearing without any assistance at the end of the first postoperative year. Early aggressive debridement and irrigation followed by fixation with percutaneous Kirschner wires and external fixator can supply bony alignment in open comminuted calcaneal fractures associated with concomitant lower extremity injuries and should be considered for the healthy and active patients before primary arthrodesis

    Estimating the prevalence and predictors of musculoskeletal disorders in Tanzania: a cross-sectional pilot study

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    \ua9 2024, African Field Epidemiology Network. All rights reserved.Introduction: musculoskeletal (MSK) disorders account for approximately 20% of all years lived with disability worldwide however studies of MSK disorders in Africa are scarce. This pilot study aimed to estimate the community-based prevalence of MSK disorders, identify predictors, and assess the associated disability in a Tanzanian population. Methods: a cross-sectional study was conducted in one village in the Kilimanjaro region from March to June 2019. The Gait, Arms, Legs, Spine (GALS) or paediatric GALS (pGALS) examinations were used during household and school visits. Individuals positive in GALS/pGALS screening were assessed by the regional examination of the musculoskeletal system (REMS) and Modified Health Assessment Questionnaire (MHAQ). Results: among the 1,172 individuals enrolled in households, 95 (8.1%, 95% CI: 6.6-9.8) showed signs of MSK disorders using the GALS/pGALS examination and 37 (3.2%, 95% CI: 2.2-4.3) using the REMS. Among 682 schools enrolled children, seven showed signs of MSK disorders using the GALS/pGALS examination (1.0%, 95% CI: 0.4-2.1) and three using the REMS (0.4%, 95% CI: 0.0-1.3). In the household-enrolled adult population, female gender and increasing age were associated with GALS and REMS-positive findings. Among GALS-positive adults, increasing age was associated with REMS-positive status and increasing MHAQ score. Conclusion: this Tanzanian study demonstrates a prevalence of MSK disorders and identifies predictors of MSK disorders comparable to those seen globally. These findings can inform the development of rheumatology services and interventions in Tanzania and the design of future investigations of the determinants of MSK disorders, and their impacts on health, livelihoods, and well-being

    The 1988 and 2002 phocine distemper virus epidemics in European harbour seals

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    We present new and revised data for the phocine distemper virus (PDV) epidemics that resulted in the deaths of more than 23 000 harbour seals Phoca vitulina in 1988 and 30 000 in 2002. On both occasions the epidemics started at the Danish island of Anholt in central Kattegat, and subsequently spread to adjacent colonies in a stepwise fashion. However, this pattern was not maintained throughout the epidemics and new centres of infection appeared far from infected populations on some occasions: in 1988 early positive cases were observed in the Irish Sea, and in 2002 the epidemic appeared in the Dutch Wadden Sea, 6 wk after the initiation of the outbreak at Anholt Island. Since the harbour seal is a rather sedentary species, such 'jumps' in the spread among colonies suggest that another vector species could have been involved. We discussed the role of sympatric species as disease vectors, and suggested that grey seal populations could act as reservoirs for PDV if infection rates in sympatric species are lower than in harbour seals. Alternatively, grey seals could act as subclinical infected carriers of the virus between Arctic and North Sea seal populations. Mixed colonies of grey and harbour seal colonies are found at all locations where the jumps occurred, It seems likely that grey seals, which show long-distance movements, contributed to the spread among regions. The harbour seal populations along the Norwegian coast and in the Baltic escaped both epidemics, which could be due either to genetic differences among harbour seal populations or to immunity. Catastrophic events such as repeated epidemics should be accounted for in future models and management strategies of wildlife populations

    \u3ci\u3eSenecio Conrathii\u3c/i\u3e N.E.Br. (Asteraceae), a New Hyperaccumulator of Nickel from Serpentinite Outcrops of the Barberton Greenstone Belt, South Africa

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    Five nickel hyperaccumulators belonging to the Asteraceae are known from ultramafic outcrops in South Africa. Phytoremediation applications of the known hyperaccumulators in the Asteraceae, such as the indigenous Berkheya coddii Roessler, are well reported and necessitate further exploration to find additional species with such traits. This study targeted the most frequently occurring species of the Asteraceae on eight randomly selected serpentinite outcrops of the Barberton Greenstone Belt. Twenty species were sampled, including 12 that were tested for nickel accumulation for the first time. Although the majority of the species were excluders, the known hyperaccumulators Berkheya nivea N.E.Br. and B. zeyheri (Sond. & Harv.) Oliv. & Hiern subsp. rehmannii (Thell.) Roessler var. rogersiana (Thell.) Roessler hyperaccumulated nickel in the leaves at expected levels. A new hyperaccumulator of nickel was discovered, Senecio conrathii N.E.Br., which accumulated the element in its leaves at 1695 ± 637 µg g−1 on soil with a total and exchangeable nickel content of 503 mg kg−1 and 0.095 µg g−1, respectively. This makes it the third known species in the Senecioneae of South Africa to hyperaccumulate nickel after Senecio anomalochrous Hilliard and Senecio coronatus (Thunb.) Harv., albeit it being a weak accumulator compared with the latter. Seven tribes in the Asteraceae have now been screened for hyperaccumulation in South Africa, with hyperaccumulators only recorded for the Arctoteae and Senecioneae. This suggests that further exploration for hyperaccumulators should focus on these tribes as they comprise all six species (of 68 Asteraceae taxa screened thus far) to hyperaccumulate nickel

    The copper centers of tyramine β-monooxygenase and its catalytic-site methionine variants: an X-ray absorption study

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    Tyramine β-monooxygenase (TBM) is a member of a family of copper monooxygenases containing two noncoupled copper centers, and includes peptidylglycine monooxygenase and dopamine β-monooxygenase. In its Cu(II) form, TBM is coordinated by two to three His residues and one to two non-His O/N ligands consistent with a [CuM(His)2(OH2)2–CuH(His)3(OH2)] formulation. Reduction to the Cu(I) state causes a change in the X-ray absorption spectroscopy (XAS) spectrum, consistent with a change to a [CuM(His)2S(Met)–CuH(His)3] environment. Lowering the pH to 4.0 results in a large increase in the intensity of the Cu(I)–S extended X-ray absorption fine structure (EXAFS) component, suggesting a tighter Cu–S bond or the coordination of an additional sulfur donor. The XAS spectra of three variants, where the CuM Met471 residue had been mutated to His, Cys, and Asp, were examined. Significant differences from the wild-type enzyme are evident in the spectra of the reduced mutants. Although the side chains of His, Cys, and Asp are expected to substitute for Met at the CuM site, the data showed identical spectra for all three reduced variants, with no evidence for coordination of residue 471. Rather, the K-edge data suggested a modest decrease in coordination number, whereas the EXAFS indicated an average of two His residues at each Cu(I) center. These data highlight the unique role of the Met residue at the CuM center, and pose interesting questions as to why replacement by the cuprophilic thiolate ligand leads to detectable activity whereas replacement by imidazole generates inactive TBM

    Breast cancer incidence and mortality in Tyrol/Austria after fifteen years of opportunistic mammography screening

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to analyse breast cancer incidence and mortality in Tyrol from 1970 to 2006, namely after performing more than a decade of opportunistic mammography screening and just before piloting an organised screening programme. Our investigation was conducted on a population level.</p> <p>Methods</p> <p>To study time trends in breast cancer incidence and mortality, we applied the age-period-cohort model by Poisson regression to the official mortality data covering more than three decades from 1970 to 2006 and to the incidence data ranging from 1988 to 2006. In addition, for incidence data we analysed data on breast cancer staging and compared these with EU guidelines.</p> <p>Results</p> <p>For the analysis of time trend in breast cancer mortality in age groups 40-79, an age-period-cohort model fits well and shows for years 2002-2006 a statistically significant reduction of 26% (95% CI 13%-36%) in breast cancer mortality as compared to 1992-1996.</p> <p>We see only slight non-significant increases in breast cancer incidence. For the past five years, incidence data show a 10% proportion of in situ cases, and of 50% for cases in stages II+.</p> <p>Conclusions</p> <p>The opportunistic breast cancer screening programme in Tyrol has only in part exploited the mortality reduction known for organised screening programmes. There seems to be potential for further improvement, and we recommend that an organised screening programme and a detailed screening database be introduced to collect all information needed to analyse the quality indicators suggested by the EU guidelines.</p

    Economic evaluation of three populational screening strategies for cervical cancer in the county of Valles Occidental: CRICERVA clinical trial

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    Copyright @ 2011 Acera et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.A high percentage of cervical cancer cases have not undergone cytological tests within 10 years prior to diagnosis. Different population interventions could improve coverage in the public system, although costs will also increase. The aim of this study was to compare the effectiveness and the costs of three types of population interventions to increase the number of female participants in the screening programmes for cancer of the cervix carried out by Primary Care in four basic health care areas.Fondo de Investigación Sanitaria del Instituto Carlos III de Madri
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