MRI characterization of 124 CT-indeterminate focal hepatic lesions: evaluation of clinical utility

Objective. To evaluate the diagnostic yield of MRI performed for characterization of focal hepatic lesions that are interpreted as indeterminate on CT. Patients and methods. In a retrospective investigation, 124 indeterminate focal hepatic lesions in 96 patients were identified on CT examinations over 5 years from 1997 to 2001. All patients had MRI performed for the liver within 6 weeks of their CT examination. CT and MR images were reviewed independently by two separate groups of two radiologists. The value of MRI in characterizing these lesions was assessed. Diagnoses were confirmed based on histology, characteristic imaging features, and clinical follow-up . Results. MRI definitely characterized 73 lesions (58%) that were indeterminate on CT. MRI was accurate in 72/73 of these lesions. MRI could not definitely characterize 51 lesions (42%). Ten lesions were not visualized on MRI, and follow-up imaging confirmed that no lesion was present in eight of these cases (pseudolesions). Conclusion. MRI is valuable for the characterization of indeterminate focal hepatic lesions detected on CT.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75168/1/13651820701216950.pd

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Modelling predation in functional response

Functional response is important in understanding the dynamics of predator-prey systems-it is essentially the interpretation of a bio-assay system in which individual predators have access to fixed numbers of prey for a given period of time. The classical approach to the problem has entailed the use of mechanistic models to interpret the data, but more recently several papers have argued that the use of simple logistic regression is both more consistent with the nature of the data and allows for the stochastic variation inherent in the system. Nevertheless, both the classical approach and this newer interpretation focus only on the modelling of means, and ignore the variability of the data. Another overlooked difficulty is that many published data sets display over-dispersion which itself may be a function of prey density In this paper we present some models which, as well as modelling the mean response, also account for the over-dispersion. The beta-binomial is a common model for admitting extra-variation, and here we develop some variants that allow a dependency on prey density. We also develop some new models based on stochastic counting processes. These models are compared and contrasted on a strict likelihood basis. It is found that beta-binomial models provide a markedly better fit to the data than do simple binomial models. The best-fitting counting process model is almost as good (in likelihood terms) as the best-fitting beta-binomial model. We argue that the counting process models offer richer insights into the predation process than do the other more 'descriptive' models. (c) 2006 Elsevier B.V. All rights reserved

Thigh-length compression stockings and DVT after stroke

Controversy exists as to whether neoadjuvant chemotherapy improves survival in patients with invasive bladder cancer, despite randomised controlled trials of more than 3000 patients. We undertook a systematic review and meta-analysis to assess the effect of such treatment on survival in patients with this disease

Egg distributions of insect parasitoids: modelling and analysis of temporal data with host density dependence

A simple numerical procedure is presented for the problem of estimating the parameters of models for the distribution of eggs oviposited in a host. The modelling is extended to incorporate both host density and time dependence to produce a remarkably parsimonious structure with only seven parameters to describe a data set of over 3,000 observations. This is further refined using a mixed model to accommodate several large outliers. Both models show that the level of superparasitism declines with increasing host density, and the rate declines over time. It is proposed that the differing behaviours represented by the mixed model may reflect a balance between behavioural strategies of different selective benefit

Rapport du séminaire de l'OCDE sur l'analyse statistique des données de toxicité aquatique

Following a decision taken by the National Co-ordinators of the OECD Test Guideline Programme and the OECD Risk Assessment Advisory Body (RAAB) at their joint session in December 1995, an OECD Workshop on Statistical Analysis of Aquatic Ecotoxicity Data was held in Braunschweig, Germany on 15-17 October 1996. The workshop was hosted by the Biologische Bundesanstalt für Land-und Forstwirtschaft (BBA) in Braunschweig and was chaired by Dr Arno Lange of the German Umweltbundesamt (UBA). The objectives of the workshop were: • to review the options available for the analysis of data from ecotoxicity tests; • to compare their advantages and disadvantages; • to recommend (a) the most appropriate approach for deriving a summary parameter(s) which has (have) scientific validity, and (b) further work to be undertaken by the OECD and/or others, as appropriate. In plenary and working group sessions participants discussed statistical data analysis appropriate for single-species chronic/subchronic studies using a number of test concentrations, i.e. dose-response tests. Aquatic tests served as a basis for these discussions, however the issues addressed may be similar for toxicity tests in general. Background documents had been prepared on the following main existing data analysis approaches for such tests: analysis of variance/hypothesis testing (“ANOVA/NOEC approach”); regression analysis (based on empirical models); and mechanistic modelling (theory-based). It was concluded that the NOEC, as the main summary parameter of aquatic ecotoxicity tests, is inappropriate for a number of reasons (see detailed discussion in the report) and should therefore be phased out. It was recommended that the OECD should move towards a regression-based estimation procedure. The time course of effects should be incorporated in the analytical procedures, and the OECD should initiate a study of the available time-dependent regression models (both mechanistic and empirical) in order to select those which best meet its needs. The study should also address the issue of appropriate values of x for ECx and the optimal experimental designs. A steering group should be set up to direct the mathematical, statistical and biological work required to take the workshop recommendations forward. This group should include representatives from the appropriate scientific and regulatory communities.Suite à une décision des Coordinateurs nationaux du Programme de l’OCDE sur les Lignes directrices pour les essais et du Groupe consultatif de l’OCDE sur l’évaluation des risques (RAAB) lors de leur session conjointe en décembre 1995, un atelier de l’OCDE sur l’analyse statistique des données d’écotoxicité aquatique s’est tenu à Braunschweig, en Allemagne du 15 au 17 octobre 1996. L’atelier fut accueilli par le Biologische Bundesanstalt für Land-und Forstwirtschaft (BBA), sous la présidence du Docteur Arno Lange du Umweltbundesamt (UBA). L’atelier avait pour objectifs de: • examiner les différentes options existantes pour l’analyse des données des essais d’écotoxicité; • comparer leurs avantages et leurs inconvénients; • faire des recommandations concernant (a) l’approche la plus appropriée pour obtenir un/des paramètre(s) “résumé(s)” qui soi(en)t scientifiquement valides, et (b) les travaux ultérieurs qu’il conviendrait que l’OCDE et/ou d’autres mettent en oeuvre; Au cours des sessions plénières et des sessions de groupe de travail, les participants ont débattu de l’analyse statistique des données relatives aux études chroniques/subchroniques réalisées sur un seul organisme et utilisant un certain nombre de concentrations, c’est-à-dire les essais dits “dose-réponse”. Les essais dans le domaine aquatique ont servi de base aux discussions; cependant, les questions abordées peuvent être les mêmes pour les essais de toxicité et concernent les principales approches pour l’analyse des données d’essais que sont: l’analyse de la variance/hypothèse d’essai (“approche ANOVA/NOEC”) , l’analyse de régression (basée sur les modèles empiriques), et la modélisation méchanistique (basée sur la théorie). Il a été conclu que, pour un certain nombre de raisons (voir les arguments détaillés dans ce rapport), la NOEC ne convient pas comme principal paramètre “résumé” des essais d’écotoxicité aquatique et qu’elle devrait donc être progressivement abandonnée. Il a été recommandé que l’OCDE s’oriente vers une procédure d’estimation basée sur la régression. Les effets au cours de temps devraient être pris en compte dans les procédures analytiques, et l’OCDE devrait mettre en place une étude des modèles disponibles de régression dépendants du temps (à la fois méchanistique et empirique) afin de choisir ceux qui correspondent le mieux aux besoins de l’OCDE. L’étude devrait aussi aborder la question des valeurs appropriées de x pour l’ECx et celle de la conception optimale des essais. Un groupe directeur devrait diriger les travaux d’ordre mathématique, statistique et biologique nécessaires afin de mettre en place les recommandations de l’atelier. Ce groupe devrait être composé de représentants des communautés scientifiques et réglementaires compétentes.OECD Environmental Health and Safety Publication