251 research outputs found

    Corrélation entre l'excrétion des mycoplasmes et les cinétiques des anticorps mis en évidence par fixation du complément, hémagglutination passive et séroagglutination rapide, au cours d'une infection expérimentale de bovins par Mycoplasma mycoides subsp. mycoides SC

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    Dans un foyer expérimental de péripneumonie contagieuse bovine (PCB), 5 bovins infectés expérimentalement et 5 bovins infectés naturellement au contact des premiers ont fait l'objet d'un suivi hebdomadaire de l'excrétion de Mycoplasma mycoides subsp. mycoides SC et d'un suivi sérologique en fixation du complément (FC), en hémagglutination passive (HAP) et en séroagglutination rapide (SAG). Ces suivis ont été effectués sur 4 mois à compter de l'inoculation. Dans les cas d'évolution aiguë ou chronique avec lésions, aucune défaillance du dépistage en FC et en SAG excepté en phase prodromique n'a été constatée sur une période de 11 à 13 semaines aprÚs le début de l'excrétion. L'HAP semble pouvoir détecter précocement les infections débutantes, mais est insuffisante en phase chronique et ultime de la maladie. Dans les cas d'infection latente évoluant sans symptÎme ni lésion malgré une excrétion prolongée dans le temps, des défaillances importantes du dépistage sont notées, cela quelle que soit la technique utilisée (Résumé d'auteur

    Characteristics of scattered electron beams shaped with a multileaf collimator

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134775/1/mp8046.pd

    Recherche sur l'origine des fausses réactions positives dans le diagnostic sérologique de la péripneumonie contagieuse bovine

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    Des bovins ont été expérimentalement immunisés respectivement avec Mycoplasma (M) capricolum, M. mycoides subsp. mycoides (LC), M. mycoides subsp. capri, M. species groupe 7 de LEACH. Pendant 8 semaines ces animaux ont fait l'objet d'un suivi sérologique vis-à-vis de l'agent de la péripneumon ie contagieuse bovine (PPCB), par le test immunoenzymatique (ELISA), en fixation du complément (FC) et en hémagglutination passive (HAP), l'HAP étant effectuée également vis-à-vis des valences d'immunisation. En FC, utilisée selon la méthode standardisée, des réactions croisées, souvent transitoires, sont notées chez les bovins immunisés par le groupe 7 et les 2 "mycoides" caprins. Ce modÚle experimental pourrait expliquer certaines réactions aspécifiques naturelles rencontrées exceptionnellement lors du diagnostic sérologique de la PPC

    The management of hepatobiliary cystadenomas: lessons learned

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    AbstractBackgroundMucinous cystic neoplasms of the liver (hepatobiliary cystadenomas) are rare neoplastic lesions. Such cysts are often incorrectly diagnosed and managed, and carry a risk of malignancy. The objective of this study was to review the surgical experience with these lesions over 15 years.MethodsA retrospective chart review identified consecutive patients undergoing surgery for liver cystadenomas from 1997–2011. Clinical data were collected and summarized.ResultsThirteen patients (mean age 51 years, 12/13 females) with cysts 4.6–18.1cm were identified. Most cysts were located in the left lobe/centrally (11/12) and had septations (8/13). Mural nodularity was infrequent (3/13). Nine patients had liver resection/enucleation, whereas four had unroofing. Frozen section analysis had a high false‐negative rate (4/6). All patients had cystadenomas, of which two had foci of invasive carcinoma (cystadenocarcinoma) within mural nodules. There was no 90‐day mortality. All but one patient (myocardial infarction) were alive at a median follow‐up of 23.1 months. No patient with unroofing has developed malignancy to date.ConclusionsNon‐invasive hepatobiliary cystadenomas present as large central/left‐sided cysts in young or middle‐aged women. Associated malignancy was relatively uncommon and found within mural nodules. Intra‐operative frozen section analysis was ineffective at ruling out cystadenomas. Complete excision is recommended, but close follow‐up might be considered in patients with a prohibitive technical or medical risk, in the absence of nodularity on high‐quality imaging

    Long term evaluation of disease progression through the quantitative magnetic resonance imaging of symptomatic knee osteoarthritis patients: correlation with clinical symptoms and radiographic changes

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    The objective of this study was to further explore the cartilage volume changes in knee osteoarthritis (OA) over time using quantitative magnetic resonance imaging (qMRI). These were correlated with demographic, clinical, and radiological data to better identify the disease risk features. We selected 107 patients from a large trial (n = 1,232) evaluating the effect of a bisphosphonate on OA knees. The MRI acquisitions of the knee were done at baseline, 12, and 24 months. Cartilage volume from the global, medial, and lateral compartments was quantified. The changes were contrasted with clinical data and other MRI anatomical features. Knee OA cartilage volume losses were statistically significant compared to baseline values: -3.7 ± 3.0% for global cartilage and -5.5 ± 4.3% for the medial compartment at 12 months, and -5.7 ± 4.4% and -8.3 ± 6.5%, respectively, at 24 months. Three different populations were identified according to cartilage volume loss: fast (n = 11; -13.2%), intermediate (n = 48; -7.2%), and slow (n = 48; -2.3%) progressors. The predictors of fast progressors were the presence of severe meniscal extrusion (p = 0.001), severe medial tear (p = 0.005), medial and/or lateral bone edema (p = 0.03), high body mass index (p < 0.05, fast versus slow), weight (p < 0.05, fast versus slow) and age (p < 0.05 fast versus slow). The loss of cartilage volume was also slightly associated with less knee pain. No association was found with other Western Ontario McMaster Osteoarthritis Index (WOMAC) scores, joint space width, or urine biomarker levels. Meniscal damage and bone edema are closely associated with more cartilage volume loss. These data confirm the significant advantage of qMRI for reliably measuring knee structural changes at as early as 12 months, and for identifying risk factors associated with OA progression

    Association between meniscal tears and the peak external knee adduction moment and foot rotation during level walking in postmenopausal women without knee osteoarthritis: a cross-sectional study

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    Introduction Meniscal injury is a risk factor for the development and progression of knee osteoarthritis, yet little is known about risk factors for meniscal pathology. Joint loading mediated via gait parameters may be associated with meniscal tears, and determining whether such an association exists was the aim of this study. Methods Three-dimensional Vicon gait analyses were performed on the dominant knee of 20 non-osteoarthritic women, and the peak external knee adduction moment during early and late stance was determined. The degree of foot rotation was also examined when the knee adductor moment peaked during early and late stance. Magnetic resonance imaging was used to determine the presence and severity of meniscal lesions in the dominant knee. Results The presence (P = 0.04) and severity (P = 0.01) of medial meniscal tears were positively associated with the peak external knee adduction moment during early stance while a trend for late stance was observed (P = 0.07). They were also associated with increasing degrees of internal foot rotation during late stance, independent of the magnitude of the peak external knee adduction moment occurring at that time (P = 0.03). During level walking among healthy women, the presence and severity of medial meniscal tears were positively associated with the peak external knee adduction moment. Moreover, the magnitude of internal foot rotation was associated with the presence and severity of medial meniscal lesions, independent of the peak knee adductor moment during late stance. Conclusion These data may suggest that gait parameters may be associated with meniscal damage, although longitudinal studies will be required to clarify whether gait abnormalities predate meniscal lesions, or vice versa, and therefore whether modification of gait patterns may be helpful

    Value of biomarkers in osteoarthritis: Current status and perspectives

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    Osteoarthritis affects the whole joint structure with progressive changes in cartilage, menisci, ligaments and subchondral bone, and synovial inflammation. Biomarkers are being developed to quantify joint remodelling and disease progression. This article was prepared following a working meeting of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis convened to discuss the value of biochemical markers of matrix metabolism in drug development in osteoarthritis. The best candidates are generally molecules or molecular fragments present in cartilage, bone or synovium and may be specific to one type of joint tissue or common to them all. Many currently investigated biomarkers are associated with collagen metabolism in cartilage or bone, or aggrecan metabolism in cartilage. Other biomarkers are related to non-collagenous proteins, inflammation and/or fibrosis. Biomarkers in osteoarthritis can be categorised using the burden of disease, investigative, prognostic, efficacy of intervention, diagnostic and safety classification. There are a number of promising candidates, notably urinary C-terminal telopeptide of collagen type II and serum cartilage oligomeric protein, although none is sufficiently discriminating to differentiate between individual patients and controls (diagnostic) or between patients with different disease severities (burden of disease), predict prognosis in individuals with or without osteoarthritis (prognostic) or perform so consistently that it could function as a surrogate outcome in clinical trials (efficacy of intervention). Future avenues for research include exploration of underlying mechanisms of disease and development of new biomarkers; technological development; the ‘omics’ (genomics, metabolomics, proteomics and lipidomics); design of aggregate scores combining a panel of biomarkers and/or imaging markers into single diagnostic algorithms; and investigation into the relationship between biomarkers and prognosis. This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial

    Psychophysiological models of hypovigilance detection: A scoping review

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    Hypovigilance represents a major contributor to accidents. In operational contexts, the burden of monitoring/managing vigilance often rests on operators. Recent advances in sensing technologies allow for the development of psychophysiology‐based (hypo)vigilance prediction models. Still, these models remain scarcely applied to operational situations and need better understanding. The current scoping review provides a state of knowledge regarding psychophysiological models of hypovigilance detection. Records evaluating vigilance measuring tools with gold standard comparisons and hypovigilance prediction performances were extracted from MEDLINE, PsychInfo, and Inspec. Exclusion criteria comprised aspects related to language, non‐empirical papers, and sleep studies. The Quality Assessment tool for Diagnostic Accuracy Studies (QUADAS) and the Prediction model Risk Of Bias ASsessment Tool (PROBAST) were used for bias evaluation. Twenty‐one records were reviewed. They were mainly characterized by participant selection and analysis biases. Papers predominantly focused on driving and employed several common psychophysiological techniques. Yet, prediction methods and gold standards varied widely. Overall, we outline the main strategies used to assess hypovigilance, their principal limitations, and we discuss applications of these models

    CHERCAM: A Cherenkov imager for the CREAM experiment

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    International audienceThe CREAM experiment (Cosmic Ray Energetics and Mass) is dedicated to the measurement of the energy spectrum of nuclear elements in cosmic rays, over the range 1012^{12} to 1015^{15} eV. The individual elements separation, which is a key feature of CREAM, requires instruments with strong identification capabilities. A proximity focused type of Cherenkov imager, CHERCAM (CHERenkov CAMera), providing both a good signature of downgoing Z=1 particles and good single element separation through the whole range of nuclear charges [Buénerd et al. 28th ICRC, Tsukuba, OG 1.5, 2003, p. 2157], is under development. After a brief introduction, the main features and the construction status of the CHERCAM are being summarized
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