335 research outputs found
Oral contraceptives and rheumatoid arthritis : further epidemiologic evidence for a protective effect
In Chapter I the history of the investigation is described: the literature
reports that the pill would halve the incidence of rheumatoid arthritis which
first drew our attention, our initial views on how to test this hypothesis by
means of a case-control study, and the opportunity presented by the
rheumatologic registry at the Erasmus University Rotterdam. The aim of
the study is stated: to investigate whether the halving of the incidence of
rheumatoid arthritis among oral-contraceptive users relative to never-users,
as originally described in a follow-up study in Great Britain, would also be
demonstrable in a case-control study in the Netherlands.
In Chapter II the reasons for starting the investigation are elaborated.
First, the relevant literature is critically reviewed. The evidence for a
negative association between oral-contraceptive use and the development
of rheumatoid arthritis is judged interesting, although still wanting: several
objections to the validity of the inference can be formulated. Second, the
phenomenon is interesting from a point of view of public health. If the pill
protects against a crippling disease which is frequent in women, this might
to a certain extent balance the negative aspects of its cardiovascular
side-effects. Third, there is a strong biological interest. If the pill causally
prevents rheumatoid arthritis, this provides another piece of the puzzle of
the pathogenesis of this disease, which advances the state of our knowledge.
The fourth and last reason for starting the investigation was the unique
opportunity of a rheumatology registry that covers the patients of several
of the major rheumatology clinics in the Netherlands
Das Strengthening the Reporting of Observational Studies in Epidemiology (STROBE-) Statement: Leitlinien für das Berichten von Beobachtungsstudien
Zusammenfassung: Ein Großteil der biomedizinischen Forschung ist beobachtend, und die Qualität der veröffentlichten Berichte über diese Forschung ist oft unzureichend. Dies behindert die Beurteilung der Stärken und Schwächen einer Studie und ihrer Übertragbarkeit. Die Strengthening the Reporting of Observational Studies in Epidemiology (STROBE-) Initiative hat Empfehlungen entwickelt, was in einem akkuraten und vollständigen Bericht einer Beobachtungsstudie enthalten sein sollte. Die Empfehlungen wurden von uns so definiert, dass sie 3Hauptstudientypen abdecken: Kohorten-, Fallkontroll- und Querschnittsstudien. Im September 2004 veranstalteten wir einen zweitägigen Workshop mit Methodikern, Forschern und Herausgebern wissenschaftlicher Zeitschriften, um eine Checkliste zu entwerfen. Anschließend wurde der Entwurf bei mehreren Treffen der Koordinierungsgruppe und nach E-Mail-Diskussionen mit der erweiterten STROBE-Gruppe revidiert und dabei empirische Evidenz und methodologische Aspekte berücksichtigt. Das Ergebnis des Workshops und des anschließenden iterativen Prozesses aus Beratung und Revision war eine Checkliste von 22Punkten (STROBE-Statement), die sich auf die Bereiche Titel, Abstract, Einleitung, Methoden, Ergebnisse und Diskussion eines Artikels beziehen. 18 der Punkte sind relevant für alle 3Studiendesigns, während 4 der Punkte spezifisch für Kohorten-, Fallkontroll- und Querschnittsstudien sind. Ein ausführlicher Begleitartikel (Explanation and Elaboration) wurde separat veröffentlicht und ist auf den Webseiten von PLoS Medicine, Annals of Internal Medicine und Epidemiology frei zugänglich. Wir hoffen, dass das STROBE-Statement dazu beitragen kann, dass Beobachtungsstudien besser berichtet werde
The influence of the diagnostic technique on the histopathological diagnosis in malignant mesothelioma
In the histopathology of malignant mesotheliomas three different types (epithelial, connective tissue and mixed type) are distinguished. Some authors believe all tumours to be of mixed type, but consider that due to inadequate sampling or small biopsies this may be missed frequently. In this study the relationship between the histopathological diagnosis and the amount of tissue examined was investigated. In a series of 124 cases of malignant pleural mesothelioma a high percentage of mixed type tumours was found (55%). In cases where the decisive diagnostic procedure had been an Abrams biopsy (the "small-specimen" technique) mixed-type histology was found in 36%. If thoracoscopy, thoracotomy or autopsy (the "large-specimen" techniques) had delivered a definite diagnosis, mixed-type histology was found in 63%. Apparently diagnosing the mixed-type variety depends on the amount of tumour tissue obtained. However, the assumption that all mesotheliomas are of mixed type cannot be confirmed
Plasmid-mediated AmpC
_Objectives:_ The objective of this study was to determine the prevalence of pAmpC beta-lactamases in community-acquired Gram negative bacteria in the Netherlands, and to identify possible risk factors for carriage of these strains. Methods: Fecal samples were obtained from community-dwelling volunteers. Participants also returned a questionnaire for analysis of risk factors. Screening for pAmpC was performed with selective enrichment broth and a selective screening agar. Confirmation of AmpC-production was performed with two double disc combination tests: cefotaxime and ceftazidime with either boronic acid or cloxacillin as inhibitor. Multiplex PCR was used as gold standard for detection of pAmpC. 16S rRNA PCR and AFLP were performed as required, plasmids were identified by PCR-based replicon typing. Questionnaire results were analyzed with SPSS, version 20.0. Results: Fecal samples were obtained from 550 volunteers; mean age 51 years (range: 18-91), 61% were females. pAmpC was present in seven E. coli isolates (7/550, 1.3%, 0.6-2.7 95% CI): six CMY-2-like pAmpC and one DHA. ESBL-encoding genes were found in 52/550 (9.5%, 7.3-12.2 95% CI) isolates; these were predominantly blaCTX-M genes. Two isolates had both ESBL and pAmpC. Admission to a hospital in the previous year was the only risk factor we identified. Conclusions: Our data indicate that the prevalence of pAmpC in the community seems still low. However, since pAmpC-producing isolates were not identified as ESBL producers by routine algorithms, there is consistent risk that further increase of their prevalence might go undetected
Factor V Leiden mutation, prothrombin gene mutation, and deficiencies in coagulation inhibitors associated with Budd-Chiari syndrome and portal vein thrombosis: results of a case-control study
In a collaborative multicenter case-control study, we investigated the
effect of factor V Leiden mutation, prothrombin gene mutation, and
inherited deficiencies of protein C, protein S, and antithrombin on the
risk of Budd-Chiari syndrome (BCS) and portal vein thrombosis (PVT). We
compared 43 BCS patients and 92 PVT patients with 474 population-based
controls. The relative risk of BCS was 11.3 (95% CI 4.8-26.5) for
individuals with factor V Leiden mutation, 2.1(95% CI 0.4-9.6) for those
with prothrombin gene mutation, and 6.8 (95% CI 1.9-24.4) for those with
protein C deficiency. The relative risk of PVT was 2.7 (95% CI 1.1-6.9)
for individuals with factor V Leiden mutation, 1.4 (95% CI 0.4-5.2) fo
Leading order determination of the gluon polarisation from DIS events with high-p_T hadron pairs
We present a determination of the gluon polarisation Delta g/g in the
nucleon, based on the longitudinal double-spin asymmetry of DIS events with a
pair of large transverse-momentum hadrons in the final state. The data were
obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon
beam scattering off a polarised ^6LiD target. The gluon polarisation is
evaluated by a Neural Network approach for three intervals of the gluon
momentum fraction x_g covering the range 0.04 < x_g < 0.27. The values obtained
at leading order in QCD do not show any significant dependence on x_g. Their
average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at x_g=0.09
and a scale of mu^2 = 3 (GeV/c)^2.Comment: 13 pages, 6 figures and 3 table
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