Loss to follow-up in an international, multicentre observational study.

OBJECTIVE: The aim of this work was to assess loss to follow-up (LTFU) in EuroSIDA, an international multicentre observational cohort study. METHODS: LTFU was defined as no follow-up visit, CD4 cell count measurement or viral load measurement after 1 January 2006. Poisson regression was used to describe factors related to LTFU. RESULTS: The incidence of LTFU in 12 304 patients was 3.72 per 100 person-years of follow-up [95% confidence interval (CI) 3.58-3.86; 2712 LTFU] and varied among countries from 0.67 to 13.35. After adjustment, older patients, those with higher CD4 cell counts, and those who had started combination antiretroviral therapy all had lower incidences of LTFU, while injecting drug users had a higher incidence of LTFU. Compared with patients from Southern Europe and Argentina, patients from Eastern Europe had over a twofold increased incidence of LTFU after adjustment (incidence rate ratio 2.16; 95% CI 1.84-2.53; P<0.0001). A total of 2743 patients had a period of >1 year with no CD4 cell count or viral load measured during the year; 743 (27.1%) subsequently returned to follow-up. CONCLUSIONS: Some patients thought to be LTFU may have died, and efforts should be made to ascertain vital status wherever possible. A significant proportion of patients who have a year with no follow-up visit, CD4 cell count measurement or viral load measurement subsequently return to follow-up.

INTERMED predicts non-return to work in an occupational rehabilitation setting for individuals with orthopaedic trauma-part 2

Introduction.- The model presented in part I (19 predictors) had good predictive values for non-return to work 2 years after vocational rehabilitation for orthopaedic trauma. However, the number of predictors is high for the detection of patients at risk in a clinic. For example, the INTERMED for itself consists of 20 questions and needs 20 minutes to be filled in. For this reason, the aim of this study was to compare the predictive value of different models for the prediction of non-return to work.Patients and methods.- In this longitudinal prospective study, the cohort consisted of 2156 included inpatients with orthopaedic trauma attending a rehabilitation hospital after a work, traffic, sport or leisure related injury. Two years after discharge, 1502 patients returned a questionnaire regarding return to work. We compared the area under the receiver-operator-characteristics curve (ROC) between different models: INTERMED total score, the 4 partial INTERMED scores, the items of the most predictive partial score; with or without confounders.Results.- The ROC for the total score of the INTERMED plus the five confounders of the of the part one (qualified work, speaking French, lesion of upper extremity, education and age) was 0.72. The sole partial INTERMED score to predict return to work was the social sub score. The ROC for the five items of the latter sub score of the INTERMED was 0.69. The ROC for the five items of the social subscale of the INTERMED combined with five predictors was 0.73. This was significantly better than the use of only the five items from INTERMED alone (delta 0.034; 95% CI 0.017 to .050). The model presented in part I (INTERMED total score plus 18 predictors) was not significantly better than the five items INTERMED social score plus five confounders.Discussion.- The use of a model with ten variables (INTERMED social five items plus five confounders) has good predictive value to detect patients not returning to work after vocational rehabilitation after orthopaedic trauma. The parsimony of this model facilitates its use in a clinic for the detection of patients at risk.

How important are interview methods and questionnaire designs in research on self-reported juvenile delinquency? An experimental comparison of internet vs. paper-and-pencil questionnaires and different definitions of the reference period

There has been relatively little change over recent decades in the methods used in research on self-reported delinquency. Face-to-face interviews and selfadministered interviews in the classroom are still the predominant alternatives envisaged. New methods have been brought into the picture by recent computer technology, the Internet, and an increasing availability of computer equipment and Internet access in schools. In the autumn of 2004, a controlled experiment was conducted with 1,203 students in Lausanne (Switzerland), where "paper-and-pencil" questionnaires were compared with computer-assisted interviews through the Internet. The experiment included a test of two different definitions of the (same) reference period. After the introductory question ("Did you ever..."), students were asked how many times they had done it (or experienced it), if ever, "over the last 12 months" or "since the October 2003 vacation". Few significant differences were found between the results obtained by the two methods and for the two definitions of the reference period, in the answers concerning victimisation, self-reported delinquency, drug use, failure to respond (missing data). Students were found to be more motivated to respond through the Internet, take less time for filling out the questionnaire, and were apparently more confident of privacy, while the school principals were less reluctant to allow classes to be interviewed through the Internet. The Internet method also involves considerable cost reductions, which is a critical advantage if self-reported delinquency surveys are to become a routinely applied method of evaluation, particularly so in countries with limited resources. On balance, the Internet may be instrumental in making research on self-reported delinquency far more feasible in situations where limited resources so far have prevented its implementation.

Long-distance wolf recolonization of France and Switzerland inferred from non-invasive genetic sampling over a period of 10 years

In the early 1900s, the wolf (Canis lupus) was extirpated from France and Switzerland. There is growing evidence that the species is presently recolonizing these countries in the western Alps. By sequencing the mitochondrial DNA (mtDNA) control region of various samples mainly collected in the field (scats, hairs, regurgitates, blood or tissue; n = 292), we could (1) develop a non-invasive method enabling the unambiguous attribution of these samples to wolf, fox (Vulpes vulpes) or dog (Canis familiaris), among others; (2) demonstrate that Italian, French and Swiss wolves share the same mtDNA haplotype, a haplotype that has never been found in any other wolf population world-wide. Combined together, field and genetic data collected over 10 years corroborate the scenario of a natural expansion of wolves from the Italian source population. Furthermore, such a genetic approach is of conservation significance, since it has important consequences for management decisions. This first long-term report using non-invasive sampling demonstrates that long-distance dispersers are common, supporting the hypothesis that individuals may often attempt to colonize far from their native pack, even in the absence of suitable corridors across habitats characterized by intense human activities.

The effect of a period of intensive exercise on the isoform test to detect growth hormone doping in sports.

OBJECTIVE: The major objective of this study was to investigate the effects of several days of intense exercise on growth hormone (hGH) testing using the World Anti-Doping Agencies hGH isoform differential immunoassays. Additionally the effects of circadian variation and exercise type on the isoform ratios were also investigated. STUDY DESIGN: 15 male athletes performed a simulated nine day cycling stage race. Blood samples were collected twice daily over a period of 15days (stage race+three days before and after). hGH isoforms were analysed by the official WADA immunoassays (CMZ Assay GmbH). RESULTS: All measured isoform ratios were far below the WADA decision limits for an adverse analytical finding. Changes in the isoform ratios could not be clearly connected to circadian variation, exercise duration or intensity. CONCLUSIONS: The present study demonstrates that the hGH isoform ratios are not significantly affected by exercise or circadian variation. We demonstrated that heavy, long term exercise does not interfere with the decision limits for an adverse analytical finding.

Clinical update: suspension trauma

Objective.-Suspension trauma refers to the pathophysiologic syndrome that occurs when a victim is suspended motionless in a vertical position for an extended period of time. This can occur in sports that use a harness system as well as in various occupational activities including work on high wires or helicopter rescue operations. We reviewed the scientific evidence published to date in order to improve the prevention and treatment of suspension trauma.Methods.-Medline, PreMedline, the Cochrane Library, and Google Scholar were searched for relevant information about suspension trauma.Results.-Published data describing the pathophysiology of and the therapeutic approach to suspension trauma are sparse and consist mainly of case reports and a limited number of human experimental prospective studies. The pathophysiology of suspension trauma is related to hypovolemia induced by reduced venous return and by vagal stimulation. It is also influenced by the type of harness used. Chest harnesses may induce severe cardiorespiratory repercussions and have the lowest motionless suspension tolerance. Symptoms of suspension trauma include presyncope and can lead to a loss of consciousness.Conclusions.-Sports enthusiasts and workers who use a body harness system should never act alone and should not use a simple chest harness. If a victim shows symptoms of presyncope or is unconscious, he should be released from suspension as soon as is safely possible. There is no clear evidence to support the idea that the return to the horizontal position may contribute to the potential risk of rescue death.

Reconstruction of the recent history of a large deep prealpine lake (Lake Bourget, France) using subfossil chironomids, diatoms, and organic matter analysis: towards the definition of a lake-specific reference state

This paper presents the recent history of a large prealpine lake (Lake Bourget) using chironomids, diatoms and organic matter analysis, and deals with the ability of paleolimnological approach to define an ecological reference state for the lake in the sense of the European Framework Directive. The study at low resolution of subfossil chironomids in a 4-m-long core shows the remarkable stability over the last 2.5 kyrs of the profundal community dominated by a Micropsectra-association until the beginning of the twentieth century, when oxyphilous taxa disappeared. Focusing on this key recent period, a high resolution and multiproxy study of two short cores reveals a progressive evolution of the lake's ecological state. Until AD 1880, Lake Bourget showed low organic matter content in the deep sediments (TOC less than 1%) and a well-oxygenated hypolimnion that allowed the development of a profundal oxyphilous chironomid fauna (Micropsectra-association). Diatom communities were characteristic of oligotrophic conditions. Around AD 1880, a slight increase in the TOC was the first sign of changes in lake conditions. This was followed by a first limited decline in oligotrophic diatom taxa and the disappearance of two oxyphilous chironomid taxa at the beginning of the twentieth century. The 1940s were a major turning point in recent lake history. Diatom assemblages and accumulation of well preserved planktonic organic matter in the sediment provide evidence of strong eutrophication. The absence of profundal chironomid communities reveals permanent hypolimnetic anoxia. From AD 1995 to 2006, the diatom assemblages suggest a reduction in nutrients, and a return to mesotrophic conditions, a result of improved wastewater management. However, no change in hypolimnion benthic conditions has been shown by either the organic matter or the subfossil chironomid profundal community. Our results emphasize the relevance of the paleolimnological approach for the assessment of reference conditions for modern lakes. Before AD 1900, the profundal Micropsectra-association and the Cyclotella dominated diatom community can be considered as the Lake Bourget reference community, which reflects the reference ecological state of the lake.

Newer antiepileptic drugs in the treatment of status epilepticus: Impact on prognosis.

Newer antiepileptic drugs (AEDs) are increasingly prescribed and seem to have a comparable efficacy as the classical AEDs; however, their impact on status epilepticus (SE) prognosis has received little attention. In our prospective SE database (2006-2010), we assessed the use of older versus newer AEDs (levetiracetam, pregabalin, topiramate, lacosamide) over time and its relationship to outcome (return to clinical baseline conditions, new handicap, or death). Newer AEDs were used more often toward the end of the study period (42% of episodes versus 30%). After adjustment for SE etiology, SE severity score, and number of compounds needed to terminate SE, newer AEDs were independently related to a reduced likelihood of return to baseline (p<0.001) but not to increased mortality. These findings seem in line with recent findings on refractory epilepsy. Also, in view of the higher price of the newer AEDs, well-designed, prospective assessments analyzing the impact of newer AEDs on efficacy and tolerability in patients with SE appear mandatory.

CAVIN-3 regulates circadian period length and PER:CRY protein abundance and interactions.

In mammals, transcriptional autorepression by Period (PER) and Cryptochrome (CRY) protein complexes is essential for the generation of circadian rhythms. We have identified CAVIN-3 as a new, cytoplasmic PER2-interacting protein influencing circadian clock properties. Thus, CAVIN-3 loss- and gain-of-function shortened and lengthened, respectively, the circadian period in fibroblasts and affected PER:CRY protein abundance and interaction. While depletion of protein kinase Cδ (PKCδ), a known partner of CAVIN-3, had little effect on circadian gene expression, CAVIN-3 required the PKCδ-binding site to exert its effect on period length. This suggests the involvement of yet uncharacterized protein kinases. Finally, CAVIN-3 activity in circadian gene expression was independent of caveolae.

Density, climate and varying return points: an analysis of long-term population fluctuations in the threatened European tree frog.

Experimental research has identified many putative agents of amphibian decline, yet the population-level consequences of these agents remain unknown, owing to lack of information on compensatory density dependence in natural populations. Here, we investigate the relative importance of intrinsic (density-dependent) and extrinsic (climatic) factors impacting the dynamics of a tree frog (Hyla arborea) population over 22 years. A combination of log-linear density dependence and rainfall (with a 2-year time lag corresponding to development time) explain 75% of the variance in the rate of increase. Such fluctuations around a variable return point might be responsible for the seemingly erratic demography and disequilibrium dynamics of many amphibian populations.

Intermittent atrial tachycardia facilitates atrial fibrillation by a shortening of activation recovery interval

Introduction: We recently observed in a chronic ovine model that a shortening of action potential duration (APD) as assessed by the activation recovery interval (ARI) may be a mechanism whereby pacing-induced atrial tachycardia (PIAT) facilitates atrial fibrillation (AF), mediated by a return to 1:1 atrial capture after the effective refractory period has been reached. The aim of the present study is to evaluate the effect of long term intermittent burst pacing on ARI before induction of AF.Methods: We specifically developed a chronic ovine model of PIAT using two pacemakers (PM) each with a right atrial (RA) lead separated by ∼2cm. The 1st PM (Vitatron T70) was used to record a broadband unipolar RA EGM (800 Hz, 0.4 Hz high pass filter). The 2nd was used to deliver PIAT during electrophysiological protocols at decremental pacing CL (400 beats, from 400 to 110ms) and long term intermittent RA burst pacing to promote electrical remodeling (5s of burst followed by 2s of sinus rhythm) until onset of sustained AF. ARI was defined as the time difference between the peak of the atrial repolarization wave and the first atrial depolarization. The mean ARIs of paired sequences (before and after remodeling), each consisting of 20 beats were compared.Results: As shown in the figure, ARIs (n=4 sheep, 46 recordings) decreased post remodeling compared to baseline (86±19 vs 103±12 ms, p<0.05). There was no difference in atrial structure as assessed by light microscopy between control and remodeled sheep.Conclusions: Using standard pacemaker technology, atrial ARIs as a surrogate of APDs were successfully measured in vivo during the electrical remodeling process leading to AF. The facilitation of AF by PIAT mimicking salvos from pulmonary veins is heralded by a significant shortening of ARI.