Prevalence and time course of acute mountain sickness in older children and adolescents after rapid ascent to 3450 meters

OBJECTIVE: Acute mountain sickness is a frequent and debilitating complication of high-altitude exposure, but there is little information on the prevalence and time course of acute mountain sickness in children and adolescents after rapid ascent by mechanical transportation to 3500 m, an altitude at which major tourist destinations are located throughout the world. METHODS: We performed serial assessments of acute mountain sickness (Lake Louise scores) in 48 healthy nonacclimatized children and adolescents (mean +/- SD age: 13.7 +/- 0.3 years; 20 girls and 28 boys), with no previous high-altitude experience, 6, 18, and 42 hours after arrival at the Jungfraujoch high-altitude research station (3450 m), which was reached through a 2.5-hour train ascent. RESULTS: We found that the overall prevalence of acute mountain sickness during the first 3 days at high altitude was 37.5%. Rates were similar for the 2 genders and decreased progressively during the stay (25% at 6 hours, 21% at 18 hours, and 8% at 42 hours). None of the subjects needed to be evacuated to lower altitude. Five subjects needed symptomatic treatment and responded well. CONCLUSION: After rapid ascent to high altitude, the prevalence of acute mountain sickness in children and adolescents was relatively low; the clinical manifestations were benign and resolved rapidly. These findings suggest that, for the majority of healthy nonacclimatized children and adolescents, travel to 3500 m is safe and pharmacologic prophylaxis for acute mountain sickness is not needed.

Indexing strategies for rapid searches of short words in genome sequences.

Searching for matches between large collections of short (14-30 nucleotides) words and sequence databases comprising full genomes or transcriptomes is a common task in biological sequence analysis. We investigated the performance of simple indexing strategies for handling such tasks and developed two programs, fetchGWI and tagger, that index either the database or the query set. Either strategy outperforms megablast for searches with more than 10,000 probes. FetchGWI is shown to be a versatile tool for rapidly searching multiple genomes, whose performance is limited in most cases by the speed of access to the filesystem. We have made publicly available a Web interface for searching the human, mouse, and several other genomes and transcriptomes with oligonucleotide queries.

Rapid Improvement and Maintenance of the Lipid Profile After Roux-en-Y Gastric Bypass (RYGBP)

Background: Dyslipidemia, a major component of the metabolic syndrome and an important cardiovascular risk factor, is one of the commonest comorbidity associated with morbid obesity. The aim of this paper is to show that RYGBP markedly improves dyslipidemia and that this improvement maintains over time. Patients and Methods: Prospectively updated databank for bariatric patients. Patients undergoing RYGBP have yearly blood tests during follow-up. The results for lipids at one to five years were compared with preoperative values. Results: The mean excess BMI loss after one and five years was 77,9 % and 72,3%respectively. After one year, there was a significant reduction of the mean total cholesterol, LDL-cholesterol, total cholesterol/HDL ratio and triglyceride values, which maintained up to five years, and an increase of the HDL fraction, which progressed until five years. The proportion of patients with abnormal values decreased from 24,3 to 6,2% for total cholesterol, from 45,1 to 11,7 %for HDL, from 53,3 to 21,9 for LDL, and from 40,5 to 10 % for triglycerides, with no significant change between three and five years, despite some weight regain. Conclusions: RYGBP rapidly improves all components of dyslipidemia, and thereby reduces the overall cardiovascular risk in operated patients.

Rapid LC-MS/MS quantification of the major benzodiazepines and their metabolites on dried blood spots using a simple and cost-effective sample pretreatment.

BACKGROUND: Dried blood spots (DBS) sampling has gained popularity in the bioanalytical community as an alternative to conventional plasma sampling, as it provides numerous benefits in terms of sample collection and logistics. The aim of this work was to show that these advantages can be coupled with a simple and cost-effective sample pretreatment, with subsequent rapid LC-MS/MS analysis for quantitation of 15 benzodiazepines, six metabolites and three Z-drugs. For this purpose, a simplified offline procedure was developed that consisted of letting a 5-µl DBS infuse directly into 100 µl of MeOH, in a conventional LC vial. RESULTS: The parameters related to the DBS pretreatment, such as extraction time or internal standard addition, were investigated and optimized, demonstrating that passive infusion in a regular LC vial was sufficient to quantitatively extract the analytes of interest. The method was validated according to international criteria in the therapeutic concentration ranges of the selected compounds. CONCLUSION: The presented strategy proved to be efficient for the rapid analysis of the selected drugs. Indeed, the offline sample preparation was reduced to a minimum, using a small amount of organic solvent and consumables, without affecting the accuracy of the method. Thus, this approach enables simple and rapid DBS analysis, even when using a non-DBS-dedicated autosampler, while lowering the costs and environmental impact.

Prevalence and time course of acute mountain sickness in older children and adolescents after rapid ascent to 3'450 meters

Rapport de synthèse :Grâce au développement de moyens de transport modernes, de plus en plus d'enfants et d'adolescents se rendent en haute altitude dans le cadre de leurs loisirs. Le mal aigu des montagnes est une complication fréquente des séjours en haute altitude. Ses symptômes en sont des maux de tête, une fatigue, des troubles du sommeil, des nausées et des vertiges. La vitesse d'ascension, |'attitude maximale atteinte, une susceptibilité individuelle ainsi qu'une acclimatation antérieure a l'attitude sont tous des facteurs influant sur le risque de développer un mal aigu des montagnes et sur sa sévérité. Bien que très fréquente chez l'adulte, nous ne possédions, au moment d'entreprendre |'étude faisant |'objet de cette thèse, que peu de données solides concernant la prévalence de cette affection chez l'enfant ainsi que sur son évolution au cours du temps. Cette étude a pour but de mesurer la prévalence du mal aigu des montagnes, et son évolution au cours du temps au sein d'un groupe d'enfants et d'adolescents dans des conditions contrôlées. C'est à dire en éliminant |'influence de facteurs confondants tels que l'importance de l'exercice physique fourni ou une différence dans la vitesse d'ascension. Pour ce faire nous avons évalué la présence de mal aigu des montagnes dans un groupe de 48 garçons et de filles âgés de 11 à 17 ans en bonne santé habituelle, n'ayant jamais séjourné en haute altitude au préalable. Afin d'évaluer la présence ou non de mal aigu des montagnes nous avons utilisé une version française du « Lake Louise Score >>. Les mesures furent effectuées 6,24 et 48 heures après |`arrivée à la station de recherche de la Jungfraujoch située à 3'450m. L'ascension a consisté en un trajet de train durant 2h30. Nos observations montrent que la prévalence du mal aigu des montagnes durant les 3 premiers jours ne dépasse jamais les 25%. Elle est similaire pour les deux sexes et diminue au cours du séjour. (17% après 24 heures, 8% après 48 heures) Aucun sujet n'a dû être évacué à une altitude inférieure, Cinq sujets ont eu besoin de recourir à un traitement symptomatique et y ont bien répondu Les résultats de cette étude démontrent que dans le groupe d'âge étudié, après une ascension rapide en haute altitude, la prévalence du mal aigu des montagnes est relativement faible, ses manifestations cliniques sont bénignes et, |lorsqu'' elles sont présentes, se résolvent rapidement. Ces observations suggèrent que pour la majorité des enfants et des adolescents en bonne santé et non habitués a |'attitude, un séjour en haute altitude ne présente pas de risque et une prophylaxie pharmacologique du mal aigu des montagnes n'est pas nécessaire.

Electrophysiological markers of rapid cognitive decline in mild cognitive impairment

Electroencephalography (EEG) is an easily accessible and low-cost modality that might prove to be a particularly powerful tool for the identification of subtle functional changes preceding structural or metabolic deficits in progressive mild cognitive impairment (PMCI). Most previous contributions in this field assessed quantitative EEG differences between healthy controls, MCI and Alzheimer's disease(AD) cases leading to contradictory data. In terms of MCI conversion to AD, certain longitudinal studies proposed various quantitative EEG parameters for an a priori distinction between PMCI and stable MCI. However, cross-sectional comparisons revealed a substantial overlap in these parameters between MCI patients and elderly controls. Methodological differences including variable clinical definition of MCI cases and substantial interindividual differences within the MCI group could partly explain these discrepancies. Most importantly, EEG measurements without cognitive demand in both cross-sectional and longitudinal designs have demonstrated limited sensitivity and generally do not produce significant group differences in spectral EEG parameters. Since the evolution of AD is characterized by the progressive loss of functional connectivity within neocortical association areas, event-modulated EEG dynamic analysis which makes it possible to investigate the functional activation of neocortical circuits may represent a more sensitive method to identify early alterations of neuronal networks predictive of AD development among MCI cases. The present review summarizes clinically significant results of EEG activation studies in this field and discusses future perspectives of research aiming to reach an early and individual prediction of cognitive decline in healthy elderly controls.

Rapid marine recovery after the end-Permian mass-extinction event in the absence of marine anoxia

A new Early Triassic marine fauna is described from the Central Oman Mountains. The fauna is Griesbachian in age, on the basis of abundant conodonts and ammonoids, and was deposited in an oxygenated seamount setting off the Arabian platform margin. It is the first Griesbachian assemblage from a well-oxygenated marine setting and thus provides a test for the hypothesis that widespread anoxia prevented rapid recovery. The earliest Griesbachian (parvus zone) contains a low-diversity benthic fauna dominated by the bivalves Promyalina and Claraia. A similar level of recovery characterizes the immediate postextinction interval worldwide. However, the middle upper Griesbachian sedimentary rocks (isarcica and catinata zones) contain an incredibly diverse benthic fauna of bivalves, gastropods, articulate brachiopods, a new undescribed crinoid, echinoids, and ostracods. This fauna is more diverse and ecologically complex than the typical middle to late Griesbachian faunas described from oxygen-restricted settings worldwide. The level of postextinction recovery observed in the Oman fauna is not recorded elsewhere until the Spathian. These data support the hypothesis that the apparent delay in recovery after the end-Permian extinction event was due to widespread and prolonged benthic oxygen restriction: in the absence of anoxia, marine recovery is much faster.

Ultra-rapid opiate detoxification using deep sedation and prior oral buprenorphine preparation: long-term results.

BACKGROUND: New methods of ultra-rapid opiate detoxification (URD) under intravenous sedation have been criticized because of limited data on safety and long-term follow-up. Premedication with buprenorphine has been advocated to improve safety by decreasing vomiting. Prior research has not explored URD in socially impaired patients. METHOD: Sixteen patients were detoxified with URD and prospectively evaluated over at least 30 months. Data of this procedure were compared with those of our previous study without buprenorphine preparation (Drug Alcohol Depend. 52(3) (1998) 243). The 16 patients were followed up by a general practitioner (GP) before and after URD. The GPs also supervised the 7-day course of buprenorphine treatment prescribed for the 16 patients prior to URD. RESULTS: During the procedure, only one episode of vomiting occurred instead of 13 out of 20 in our previous study. Post-procedure, only two patients experienced moderate withdrawal symptoms, such as persistent nausea, abdominal cramps and vomiting lasting from 24 to 48 h, in comparison with most patients in the previous study without buprenorphine. After a period of at least 30 months (36.0+/-6.38), the 16 patients were still alive and were regularly monitored by their GP. Only two of the 16 never relapsed after URD and reported total opiate abstinence. Fourteen patients relapsed; 12 of these were prescribed a licensed methadone substitution program and two were still using heroin. CONCLUSION: In this small sample, the data indicated that URD with buprenorphine preparation was safe and that it markedly decreased post-procedure morbidity. No patient died over a minimum 30-month follow-up period. Furthermore, the procedure was employed with socially impaired patients. In the long term, a few patients were still free of opiates, while the majority opted for a methadone maintenance program, showing that URD can serve as one possible step in a long-term treatment program.

Phylogenetic analysis of plastid and nuclear DNA sequences reveals a rapid late Miocene radiation of the temperate bamboo tribe Arundinarieae (Poaceae, Bambusoideae)

Background: Arundinarieae are a large tribe of temperate woody bamboos for which phylogenetics are poorly understood because of limited taxon sampling and lack of informative characters. Aims: This study assessed phylogenetic relationships, origins and classification of Arundinarieae. Methods: DNA sequences (plastid trnL-F; nuclear ITS) were used for parsimony and Bayesian inference including 41 woody bamboo taxa. Divergence dates were estimated using a relaxed Bayesian clock. Results: Arundinarieae were monophyletic but their molecular divergence was low compared to the tropical Bambuseae. Ancestors of the Arundinarieae lineage were estimated to have diverged from the other bamboos 23 (15-30) million years ago (Mya). However, the Arundinarieae radiation occurred 10 (6-16) Mya compared to 18 (11-25) Mya for the tropical Bambuseae. Some groups could be defined within Arundinarieae, but they do not correspond to recognised subtribes such as Arundinariinae or Shibataeinae. Conclusions: Arundinarieae are a relatively ancient bambusoid lineage that underwent a rapid radiation in the late Miocene. The radiation coincides with the continental collision of the Indo-Australian and Eurasian Plates. Arundinarieae are distributed primarily in East Asia and the Himalayas to northern Southeast Asia. It is unknown whether they were present in Asia long before their radiation, but we believe recent dispersal is a more likely scenario. Keywords: Arundinarieae; Bambuseae; internal transcribed spacer (ITS); molecular clock; phylogenetics; radiation; temperate bamboos; Thamnocalaminae; trnL-F

Rapid detection of bacterial resistance to antibiotics using AFM cantilevers as nanomechanical sensors.

The widespread misuse of drugs has increased the number of multiresistant bacteria, and this means that tools that can rapidly detect and characterize bacterial response to antibiotics are much needed in the management of infections. Various techniques, such as the resazurin-reduction assays, the mycobacterial growth indicator tube or polymerase chain reaction-based methods, have been used to investigate bacterial metabolism and its response to drugs. However, many are relatively expensive or unable to distinguish between living and dead bacteria. Here we show that the fluctuations of highly sensitive atomic force microscope cantilevers can be used to detect low concentrations of bacteria, characterize their metabolism and quantitatively screen (within minutes) their response to antibiotics. We applied this methodology to Escherichia coli and Staphylococcus aureus, showing that live bacteria produced larger cantilever fluctuations than bacteria exposed to antibiotics. Our preliminary experiments suggest that the fluctuation is associated with bacterial metabolism.

Explaining rapid transitions in the practice of flood risk management

This article draws on empirical material to reflect on what drives rapid change in flood risk management practice, reflecting wider interest in the way that scientific practices make risk landscapes and a specific focus on extreme events as drivers of rapid change. Such events are commonly referred to as a form of creative destruction, ones that reveal both the composition of socioenvironmental assemblages and provide a creative opportunity to remake those assemblages in alternate ways, therefore rapidly changing policy and practice. Drawing on wider thinking in complexity theory, we argue that what happens between events might be as, if not more, important than the events themselves. We use two empirical examples concerned with flood risk management practice: a rapid shift in the dominant technologies used to map flood risk in the United Kingdom and an experimental approach to public participation tested in two different locations, with dramatically different consequences. Both show that the state of the socioenvironmental assemblage in which the events take place matters as much as the magnitude of the events themselves. The periods between rapid changes are not simply periods of discursive consolidation but involve the ongoing mutation of such assemblages, which could either sensitize or desensitize them to rapid change. Understanding these intervening periods matters as much as the events themselves. If events matter, it is because of the ways in which they might bring into sharp focus the coding or framing of a socioenvironmental assemblage in policy or scientific practice irrespective of whether or not those events evolve the assemblage in subtle or more radical ways.

Marooned plants : vernacular naming practices in the Mascarene Islands

This article explores possible histories of plant exchanges and plant naming tied to the slave trade between East Africa, Madagascar and the Mascarene Islands. The subsequent 'marronnage' of slaves on these islands - their escape from captivity, sometimes to live in mountain hideouts - continues to inspire cultural references. Inspired by the use of the adjective 'marron/marronne' for a number of plants on Reunion Island, we compile evidence of plant exchanges and plant naming from ecological records, historical accounts and the use of descriptive, emotive or symbolic vernacular names as clues for deepening our knowledge of historical societies and environments. The evidence from the Mascarenes opens a window into the role of the African diaspora in plant introduction, diffusion, domestication and cultivation. We document that maroons relied on a variety of wild, escaped and cultivated plants for their subsistence. We also highlight the role of marronnage in the popular and literary imaginary, with the result that many plants are named 'marron/marrone' in a metaphorical sense. Finally, we identify a few plants that may have been transported, cultivated, or encouraged in one way or another by maroons. Along the way, we reflect on the pitfalls and opportunities of such interdisciplinary work.