MDCT Arthrography of the Hip: Value of the Adaptive Statistical Iterative Reconstruction Technique and Potential for Radiation Dose Reduction

Au cours des deux dernières décennies, la technique d'imagerie arthro-scanner a bénéficié de nombreux progrès technologiques et représente aujourd'hui une excellente alternative à l'imagerie par résonance magnétique (IRM) et / ou arthro-IRM dans l'évaluation des pathologies de la hanche. Cependant, elle reste limitée par l'exposition aux rayonnements ionisants importante. Les techniques de reconstruction itérative (IR) ont récemment été mis en oeuvre avec succès en imagerie ; la littérature montre que l'utilisation ces dernières contribue à réduire la dose d'environ 40 à 55%, comparativement aux protocoles courants utilisant la rétroprojection filtrée (FBP), en scanner de rachis. A notre connaissance, l'utilisation de techniques IR en arthro-scanner de hanche n'a pas été évaluée jusqu'à présent. Le but de notre étude était d'évaluer l'impact de la technique ASIR (GE Healthcare) sur la qualité de l'image objective et subjective en arthro-scanner de hanche, et d'évaluer son potentiel en terme de réduction de dose. Pour cela, trente sept patients examinés par arthro-scanner de hanche ont été randomisés en trois groupes : dose standard (CTDIvol = 38,4 mGy) et deux groupes de dose réduite (CTDIvol = 24,6 ou 15,4 mGy). Les images ont été reconstruites en rétroprojection filtrée (FBP) puis en appliquant différents pourcentages croissants d'ASIR (30, 50, 70 et 90%). Le bruit et le rapport contraste sur bruit (CNR) ont été mesurés. Deux radiologues spécialisés en imagerie musculo-squelettique ont évalué de manière indépendante la qualité de l'image au niveau de plusieurs structures anatomiques en utilisant une échelle de quatre grades. Ils ont également évalué les lésions labrales et du cartilage articulaire. Les résultats révèlent que le bruit augmente (p = 0,0009) et le CNR diminue (p = 0,001) de manière significative lorsque la dose diminue. A l'inverse, le bruit diminue (p = 0,0001) et le contraste sur bruit augmente (p < 0,003) de manière significative lorsque le pourcentage d'ASIR augmente ; on trouve également une augmentation significative des scores de la qualité de l'image pour le labrum, le cartilage, l'os sous-chondral, la qualité de l'image globale (au delà de ASIR 50%), ainsi que le bruit (p < 0,04), et une réduction significative pour l'os trabuculaire et les muscles (p < 0,03). Indépendamment du niveau de dose, il n'y a pas de différence significative pour la détection et la caractérisation des lésions labrales (n=24, p = 1) et des lésions cartilagineuses (n=40, p > 0,89) en fonction du pourcentage d'ASIR. Notre travail a permis de montrer que l'utilisation de plus de 50% d'ASIR permet de reduire de manière significative la dose d'irradiation reçue par le patient lors d'un arthro-scanner de hanche tout en maintenant une qualité d'image diagnostique comparable par rapport à un protocole de dose standard utilisant la rétroprojection filtrée.

Between-year variation in population sex ratio increases with complexity of the breeding system in Hymenoptera.

While adaptive adjustment of sex ratio in the function of colony kin structure and food availability commonly occurs in social Hymenoptera, long-term studies have revealed substantial unexplained between-year variation in sex ratio at the population level. In order to identify factors that contribute to increased between-year variation in population sex ratio, we conducted a comparative analysis across 47 Hymenoptera species differing in their breeding system. We found that between-year variation in population sex ratio steadily increased as one moved from solitary species, to primitively eusocial species, to single-queen eusocial species, to multiple-queen eusocial species. Specifically, between-year variation in population sex ratio was low (6.6% of total possible variation) in solitary species, which is consistent with the view that in solitary species, sex ratio can vary only in response to fluctuations in ecological factors such as food availability. In contrast, we found significantly higher (19.5%) between-year variation in population sex ratio in multiple-queen eusocial species, which supports the view that in these species, sex ratio can also fluctuate in response to temporal changes in social factors such as queen number and queen-worker control over sex ratio, as well as factors influencing caste determination. The simultaneous adjustment of sex ratio in response to temporal fluctuations in ecological and social factors seems to preclude the existence of a single sex ratio optimum. The absence of such an optimum may reflect an additional cost associated with the evolution of complex breeding systems in Hymenoptera societies.

Effect of weight reduction in moderately overweight patients on recorded ambulatory blood pressure and free cytosolic platelet calcium.

Although platelet cytosolic calcium has been shown to decrease during pharmacological treatment of hypertension, there is no evidence that cytosolic calcium also falls during a nonpharmacological reduction in blood pressure. To provide such evidence, we examined prospectively the relation between platelet cytosolic calcium and ambulatory blood pressure during weight reduction in moderately overweight (body mass index [BMI] greater than 25), mildly hypertensive individuals. The experimental group (responders: BMI reduction greater than 5%) consisted of 19 patients who lost 8.5 +/- 2.9 kg (mean +/- SD, p less than 0.05) during a 10-week hypocaloric diet, whereas the control group (nonresponders: BMI reduction less than 5%) consisted of 12 patients who showed no relevant change in body weight (-2.0 +/- 1.3 kg) during the same period of time. The moderate weight loss of the responders decreased blood pressure by 14/5 mm Hg (p less than 0.05), as measured by ambulatory monitoring, which renders a placebo effect unlikely. This nonpharmacological reduction in blood pressure was accompanied by a proportional 11% decrease (p less than 0.05) in platelet cytosolic calcium and also by significant (p less than 0.05) decreases in plasma catecholamines and serum cholesterol. These findings establish the concept of a nonpharmacological reduction in free cytosolic platelet calcium in humans and add further evidence suggesting a link between intracellular calcium homeostasis and blood pressure regulation.

IL28B polymorphisms predict reduction of HCV RNA from the first day of therapy in chronic hepatitis C.

Background & Aims: Single nucleotide polymorphisms (SNPs) associated with IL28B influence the outcome of peginterferon-alpha/ribavirin therapy of chronic hepatitis C virus (HCV) infection. We analyzed the kinetics of HCV RNA during therapy as a function of IL28B SNPs.Methods: IL28B SNPs rs8099917, rs12979860, and rs12980275 were genotyped in 242 HCV treatment-naive Caucasian patients (67% genotype 1, 28% genotype 2 or 3) receiving peginterferon-alpha 2a (180 mu g weekly) and ribavirin (1000-1200 mg daily) with serial HCV-RNA quantifications. Associations between IL28B polymorphisms and early viral kinetics were assessed, accounting for relevant covariates.Results: In the multivariate analyses for genotype 1 patients, the T allele of rs12979860 (T(rs12979860)) was an independent risk factor for a less pronounced first phase HCV RNA decline (log(10) 0.89 IU/ml among T carriers vs. 2.06 among others, adjusted p <0.001) and lower rapid (15% vs. 38%, adjusted p = 0.007) and sustained viral response rates (48% vs. 66%, adjusted p <0.001). In univariate analyses, Trs12979860 was also associated with a reduced second phase decline (p = 0.002), but this association was no longer significant after adjustment for the first phase decline (adjusted p = 0.8). In genotype 2/3 patients, Trs12979860 was associated with a reduced first phase decline (adjusted p = 0.04), but not with a second phase decline.Conclusions: Polymorphisms in IL28B are strongly associated with the first phase viral decline during peginterferon-alpha/ribavirin therapy of chronic HCV infection, irrespective of HCV genotype. (C) 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Reduction of plasma alanine aminotransferase during vigabatrin treatment.

In 9 drug-resistant patients with partial seizures treated with vigabatrin, gamma-vinyl GABA (VGB), alanine aminotransaminase (ALAT) activity in plasma was significantly reduced. Comparison of in vitro with in vivo measurements led us to conclude that this reduction is mainly an in vivo phenomenon, perhaps due to cross-enzyme inhibition. The assessment of two biological variables linked with ALAT, glucose and alanine levels under fasting conditions, failed to show any significant metabolic alterations. VGB is an effective drug for partial epilepsy. Our observations do not suggest that reduced ALAT activity is of clinical concern.

Complexité, médecine générale et réformes des systèmes de santé [Complexity, general practice and reforms of health systems].

The family doctor facing complexity must decide in situations of low certainty and low agreement. Complexity is in part subjective but can also be measured. Changes in the health systems aim to reduce health costs. They tend to give priority to simple situations and to neglect complexity. One role of an academic institute of family medicine is to present and promote the results of scientific research supporting the principles of family medicine, taking into account both the local context and health systems reforms. In Switzerland the new challenge is the introduction of managed care.

Inactivation des pathogènes des produits sanguins labiles: entre enjeux financiers et conséquences possibles à long terme [Pathogen reduction of blood components: from financial issues to possible long-term consequences].

Pathogen inactivation of blood products represents a global and major paradigm shift in transfusion medicine. In the next near future, it is likely that most blood products will be inactivated by various physicochemical approaches. The concept of blood safety will be challenged as well as transfusion medicine practice, notably for donor selection or biological qualification. In this context, it seems mandatory to develop analytical economic approaches by assessing costs-benefits ratio of blood transfusion as well as to set up cohorts of patients based on hemovigilance networks allowing rigorous scientific analysis of the benefits and the risks of blood transfusion at short- and long-term.

Comparison of antibiotic drops placed in the conjunctival cul-de-sac to antibiotic ointment applied to the lid margin in reduction of bacterial colonization on the lid margin.

PURPOSE: To compare the efficacy of antibiotic drops placed in the conjunctival cul-de-sac to antibiotic ointment applied to the lid margin in reduction of bacterial colonization on the lid margin. METHODS: A randomized, prospective, single-masked study was conducted on 19 patients with culture-proven colonization of bacteria on the lid margins. Ophthalmic eligibility criteria included the presence of > or =50 colony-forming units/mL (CFU/mL) of bacteria on both right and left lids. Each patient received one drop of ofloxacin in one eye every night for one week, followed by one drop once a week for one month. In the same manner, each patient received bacitracin ointment (erythromycin or gentamicin ointment if lid margin bacteria were resistant to bacitracin) to the lid margin of the fellow eye. Quantitative lid cultures were taken at initial visit, one week, one month, and two months. Fifteen volunteers (30 lids) served as controls. Lid cultures were taken at initial visit, one week, and one month. RESULTS: Both antibiotic drop and ointment reduced average bacterial CFU/mL at one week and one month. Average bacterial CFU/mL reestablished to baseline values at two months. There was no statistically significant difference between antibiotic drop and ointment in reducing bacterial colonization on the lid margin. CONCLUSION: Antibiotic drops placed in the conjunctival cul-de-sac appear to be as effective as ointment applied to the lid margins in reducing bacterial colonization in patients with > or =50 CFU/mL of bacteria on the lid margins.

Disaster Risk, Livelihoods and Natural Barriers, Strengthening Decision-Making Tools for Disaster Risk Reduction: A case study from northern Pakistan

The goal of this interdisciplinary study is to better understand the land use factors that increase vulnerability of mountain areas in northern Pakistan. The study will identify and analyse the damages and losses caused by the October 2005 earthquake in two areas of the same valley: one "low-risk" watershed with sound natural resources management, the other, "high-risk" in an ecologically degraded watershed. Secondly, the study will examine natural and man-made causes of secondary hazards in the study area, especially landslides; and third it will evaluate the cost of the earthquake damage in the study areas on the livelihoods of local communities and the sub-regional economy. There are few interdisciplinary studies to have correlated community land use practices, resources management, and disaster risk reduction in high-risk mountain areas. By better understanding these linkages, development- humanitarian- and donor agencies focused on disaster reduction can improve their risk reduction programs for mountainous regions.

Reduction des risques au cabinet du généraliste chez les consommateurs de cocaine: une perspective motivationnelle [Risk reduction among cocaine users: a motivational approach in the GP's office]

Today, cocaine use is a public health issue. Cocaine is a powerfully addictive stimulant drug which use is increasing among some part of the population. After a brief description of the physical and psychological effects of cocaine use, the article presents a motivational way for general practitioners to deal with risk-reduction issues. Based on the Transtheoretical Model of human behavior change and providing clinical examples, the article focuses particularly on the two earliest stages of change: "pre-contemplation" and "contemplation".

Taking care of the most vulnerable : a descriptive study of patients with 12 attendances or more at a Swiss university hospital emergency department in 2009

Introduction: Patients who repeatedly attend the Emergency Department (ED) often have a distinct and complex vulnerability profile that includes poor somatic, psychological, and social indicators. This profile has an impact on the patients' well-being as well as on hospital costs. The objective of the study was to specify the characteristics of hyper users (HU) and explore the connection with ED care and hospital costs. Methods: The study sample comprised all adult patients with 12 or more attendances at the ED of the Lausanne University Hospital in 2009. The data were collected by retrospectively searching internal databases to identify the patients concerned and then analysing the profiles of these patients. Information gathered included demographic, somatic, psychological, at-risk behaviour, and social indicators, and health system consumption including costs. Results: In 2009, 23 patients (0.1%) attended 12 times or more (425 attendances, 0.8%). The average age was about 43 years, 60.9% were female, and 47.8% single. Of these 95.7% had basic insurance, 87.0% had a general practitioner, and 30.4% were under legal guardianship. The majority attended in the evening or at night (67.1%), and almost one quarter of these attendances resulted in inpatient treatment (24.0%). Most HU had attended the ED in previous years too (95.7% in 2008). The most prevalent diagnoses concerned 'mental disorders' (87.0%). About 30.4% of patients had attempted suicide (all were female patients). Other frequent diagnoses concerned 'trauma' (65.2%), and the 'digestive' and the 'nervous system' (each 56.5%). At-risk behaviour such as severe alcohol consumption (34.8%), or excessive use of medicines (26.1%) was very frequent, and some patients used illicit drugs (21.7%). There was only a weak association between the number of ED attendances and the resulting costs. However, a reduction of one outpatient visit per patient would have decreased ED outpatient costs by 8.5%. Conclusions: HU often have a particularly vulnerable profile. Mental problems are prevalent among them, as are at-risk behaviour and severe somatic conditions. The complexity of the patients' profiles demands specific care that cannot be guaranteed within an everyday ED routine. The use of an interdisciplinary case management team might be a promising approach in diminishing the number of attendances and the associated costs, although the profiles of HU are such that they probably cannot completely give up ED attendance.

Pre-Treatment for Reduction of Asphalt Absorption in Porous Aggregate, April 2005

The objective of this research was to evaluate the performance of the product Ultracote® (a polymer based additive produced by Ultrapave, a division of Goodyear) as an aggregate pre-treatment for the reduction of asphalt binder absorption in hot mix asphalt (HMA). The product was tested with a paving project in Louisa county, Iowa with aggregate that had historically shown very high asphalt binder absorption. Results of the testing did not provide any evidence of reduction in binder absorption.

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Climate change data and predictions for the Himalayas are very sparse and uncertain, characterized by a ?Himalayan data gap? and difficulties in predicting changes due to topographic complexity. A few reliable studies and climate change models for Nepal predict considerable changes: shorter monsoon seasons, more intensive rainfall patterns, higher temperatures, and drought. These predictions are confirmed by farmers who claim that temperatures have been increasing for the past decade and wonder why the rains have ?gone mad.? The number of hazard events, notably droughts, floods, and landslides are increasing and now account for approximately 100 deaths in Nepal annually. Other effects are drinking water shortages and shifting agricultural patterns, with many communities struggling to meet basic food security before climatic conditions started changing. The aim of this paper is to examine existing gaps between current climate models and the realities of local development planning through a case study on flood risk and drinking water management for the Municipality of Dharan in Eastern Nepal. This example highlights current challenges facing local-level governments, namely, flood and landslide mitigation, providing basic amenities ? especially an urgent lack of drinking water during the dry season ? poor local planning capacities, and limited resources. In this context, the challenge for Nepal will be to simultaneously address increasing risks caused by hazard events alongside the omnipresent food security and drinking water issues in both urban and rural areas. Local planning is needed that integrates rural development and disaster risk reduction (DRR) with knowledge about climate change considerations. The paper concludes with a critical analysis of climate change modeling and the gap between scientific data and low-tech and low capacities of local planners to access or implement adequate adaptation measures. Recommendations include the need to bridge gaps between scientific models, the local political reality and local information needs.