Preoperative oral practices and incidence of postoperative complications in hospital medical-surgical procedures: A meta-analysis.

BACKGROUND:  Oral decay prior to a hospital medical-surgical procedure is a risk factor for the development of postoperative complications. However, perioperative oral practices as a protective factor have not been studied. This review aims to evaluate the effectiveness of perioperative oral practices in the reduction of risk of developing postoperative complications in in-hospital medical surgical procedures. MATERIAL AND METHODS: This review and meta-analysis was conducted according to Cochrane guidelines. Medline, Scopus, Scielo, and Cochrane were consulted. Articles of the previous 10 years concerning adult patients undergoing perioperative oral practices prior to hospital medical-surgical procedures, were included. Data of the type of perioperative oral practice, type of postoperative complication and measures of effect on the development of complications were extracted. RESULTS: Of a pool of 1470 articles, 13 were included for systematic review and 10 for meta-analysis. The most common perioperative oral procedures were focalized approach (FA), referred to only the elimination of infectious foci in the oral cavity and comprehensive approach (CA), referred to a integral approach of the patient's oral health, both of which were mainly performed in oncologic surgeries, both were effective in the reduction of postoperative complications (RR=0.48, [95% CI 0.36 - 0.63]). The most reported postoperative complication was postoperative pneumonia. CONCLUSIONS: Perioperative oral management proved to be a protective factor against the development of postoperative complications.

Long-term outcomes of primary cystocele repair by transvaginal mesh surgery versus laparoscopic mesh sacropexy: extended follow up of the PROSPERE multicentre randomised trial.

OBJECTIVE: To compare the effectiveness and safety of laparoscopic sacropexy (LS) and transvaginal mesh (TVM) at 4 years. DESIGN: Extended follow up of a randomised trial. SETTING: Eleven centres. POPULATION: Women with cystocele stage ≥2 (pelvic organ prolapse quantification [POP-Q], aged 45-75 years without previous prolapse surgery. METHODS: Synthetic non-absorbable mesh placed in the vesicovaginal space and sutured to the promontory (LS) or maintained by arms through pelvic ligaments and/or muscles (TVM). MAIN OUTCOME MEASURES: Functional outcomes (pelvic floor distress inventory [PFDI-20] as primary outcome); anatomical assessment (POP-Q), composite outcome of success; re-interventions for complications. RESULTS: A total of 220 out of 262 randomised patients have been followed at 4 years. PFDI-20 significantly improved in both groups and was better (but below the minimal clinically important difference) after LS (mean difference -7.2 points; 95% CI -14.0 to -0.05; P = 0.029). The improvement in quality of life and the success rate (LS 70%, 61-81% versus TVM 71%, 62-81%; hazard ratio 0.92, 95% CI 0.55-1.54; P = 0.75) were similar. POP-Q measurements did not differ, except for point C (LS -57 mm versus TVM -48 mm, P = 0.0093). The grade III or higher complication rate was lower after LS (2%, 0-4.7%) than after TVM (8.7%, 3.4-13.7%; hazard ratio 4.6, 95% CI 1.007-21.0, P = 0.049)). CONCLUSIONS: Both techniques provided improvement and similar success rates. LS had a better benefit-harm balance with fewer re-interventions due to complications. TVM remains an option when LS is not feasible. TWEETABLE ABSTRACT: At 4 years, Laparoscopic Sacropexy (LS) had a better benefit-harm balance with fewer re-interventions due to complications than Trans-Vaginal Mesh (TVM).

Oral Human Papillomavirus: a multisite infection.

BACKGROUND: The Human Papillomavirus (HPV) has different strategies for persist in the cells. This characteristic has led us to consider the presence of the virus in tissues of the oral cavity that had no clinical signs of infection. The aim of this study was to detect the presence of DNA-HPV at multiple sites of the oral cavity. MATERIAL AND METHODS: A case-control study was designed: Oral Squamous Carcinoma Group (OSCG), healthy n=72 and Control Group (CG), n=72, healthy volunteers paired by sex and age with OSCG. Four samples were taken from OSCG: saliva, biopsy, brush scraping of lesion and contralateral healthy side. In CG a saliva sample and a scratch of the posterior border of tongue were collected. HPV was detected by PCR using Bioneer Accuprep genomic DNA Extraction kit, and consensus primers MY09 and MY11. Chi square test was applied. RESULTS: 432 samples were obtained from 144 individuals. DNA-HPV was detected in 30 (42%) of OSCG subjects and 3(4%) of CG. Two or more positive samples were obtained in 67% of the OSCG, 67% in saliva and 60% in biopsy; in CG 100% of the individuals were positive in the two samples. CONCLUSIONS: HPV is frequently present in oral cavity as a multifocal infection, even without the presence of clinical lesions.

Physical inactivity and platelet function in humans and brown bears: A comparative study.

Physical inactivity increases the risk of thromboembolism. However, good standardized human models on inactivity are in short supply and experimental models are few. Our objective was to investigate how standardized bed rest affects platelet aggregation in humans and to investigate if aggregation is altered in a translational model system - the hibernating brown bear (Ursus arctos). We collected blood from (1) healthy male volunteers participating in a 21-day bed rest study in head-down tilt position (-6°) 24 h a day; (2) free-ranging brown bears captured during winter hibernation and again during active state in summer. We analyzed platelet function using multiple electrode platelet aggregometry. In total, 9 healthy male volunteers (age 31.0 ± 6.4 years) and 13 brown bears (7 females and 6 males, age 2.8 ± 0.6 years) were included. In hibernating bears adenosine diphosphate, arachidonic acid, thrombin receptor activating peptide, and collagen impedance aggregometry tests were all halved compared to summer active state. In human volunteers no statistically significant changes were found between baseline and the end of bed rest. In human male volunteers 3 weeks of bed rest did not affect platelet function. In hibernating brown bears platelet aggregation was halved compared to summer and we hypothesize that this is a protective measure to avoid formation of thrombi under periods of low blood flow.

Exercise training improves fat metabolism independent of total energy expenditure in sedentary overweight men, but does not restore lean metabolic phenotype.

BACKGROUND: Obesity is a dietary fat storage disease. Although exercise prevents weight gain, effects of chronic training on dietary fat oxidation remains understudied in overweight adults. OBJECTIVE: We tested whether 2 months of training at current guidelines increase dietary fat oxidation in sedentary overweight adults like in sedentary lean adults. DESIGN: Sedentary lean (n=10) and overweight (n=9) men trained on a cycle ergometer at 50% VO2peak, 1 h day-1, four times per week, for 2 months while energy balance was clamped. Metabolic fate of [d31]palmitate and [1-13C]oleate mixed in standard meals, total substrate use, total energy expenditure (TEE), activity energy expenditure (AEE) and key muscle proteins/enzymes were measured before and at the end of the intervention. RESULTS: Conversely to lean subjects, TEE and AEE did not increase in overweight participants due to a spontaneous decrease in non-training AEE. Despite this compensatory behavior, aerobic fitness, insulin sensitivity and fat oxidation were improved by exercise training. The latter was not explained by changes in dietary fat trafficking but more likely by a coordinated response at the muscle level enhancing fat uptake, acylation and oxidation (FABPpm, CD36, FATP1, ACSL1, CPT1, mtGPAT). ACSL1 fold change positively correlated with total fasting (R2=0.59, P<0.0001) and post-prandial (R2=0.49, P=0.0006) fat oxidation whereas mtGPAT fold change negatively correlated with dietary palmitate oxidation (R2=0.40, P=0.009), suggesting modified fat trafficking between oxidation and storage within the muscle. However, for most of the measured parameters the post-training values observed in overweight adults remained lower than the pre-training values observed in the lean subjects. CONCLUSION: Independent of energy balance and TEE, exercise training at current recommendations improved fitness and fat oxidation in overweight adults. However the improved metabolic phenotype of overweight adults was not as healthy as the one of their lean counterparts before the 2-month training, likely due to the spontaneous reduction in non-training AEE.

Drivers of hibernation in the brown bear.

BACKGROUND: Hibernation has been a key area of research for several decades, essentially in small mammals in the laboratory, yet we know very little about what triggers or ends it in the wild. Do climatic factors, an internal biological clock, or physiological processes dominate? Using state-of-the-art tracking and monitoring technology on fourteen free-ranging brown bears over three winters, we recorded movement, heart rate (HR), heart rate variability (HRV), body temperature (Tb), physical activity, ambient temperature (TA), and snow depth to identify the drivers of the start and end of hibernation. We used behavioral change point analyses to estimate the start and end of hibernation and convergent cross mapping to identify the causal interactions between the ecological and physiological variables over time. RESULTS: To our knowledge, we have built the first chronology of both ecological and physiological events from before the start to the end of hibernation in the field. Activity, HR, and Tb started to drop slowly several weeks before den entry. Bears entered the den when snow arrived and when ambient temperature reached 0 °C. HRV, taken as a proxy of sympathetic nervous system activity, dropped dramatically once the bear entered the den. This indirectly suggests that denning is tightly coupled to metabolic suppression. During arousal, the unexpected early rise in Tb (two months before den exit) was driven by TA, but was independent of HRV. The difference between Tb and TA decreased gradually suggesting that bears were not thermoconforming. HRV increased only three weeks before exit, indicating that late activation of the sympathetic nervous system likely finalized restoration of euthermic metabolism. Interestingly, it was not until TA reached the presumed lower critical temperature, likely indicating that the bears were seeking thermoneutrality, that they exited the den. CONCLUSIONS: We conclude that brown bear hibernation was initiated primarily by environmental cues, but terminated by physiological cues.

Analytical aspects of measuring (2)H/(1)H and (18)O/(16)O ratios in urine from doubly labelled water studies by high-temperature conversion elemental analyser-isotope-ratio mass spectrometry.

RATIONALE: Total Body Water (TBW) and Total Energy Expenditure (TEE) are routinely measured in free-living conditions by the (2)H2(18)O method. Isotope eliminations can be measured from spot urine samples by HTC-EA IRMS, but only after cumbersome cryogenic distillation to extract water. Distillation may, however, be replaced by charcoal treatment and filtration. This study tested (1) the effect of sample treatments (filtration versus distillation) on the isotope ratios, (2) the effect of different ways of normalization that respect or not the principle of identical treatment of the sample and references, and (3) the impact on the biological outcomes. METHODS: Two filters (PES membrane; 10 kDa) accepting volumes of urine samples (V500: 0.5 mL versus V6: 3.0 mL) were tested. In-house water standards and in-house urine standards were prepared and normalized against the international scale to calibrate the urine samples. The δ(2)H and δ(18)O values from water in the urine were measured by HTC-EA IRMS. RESULTS: Filtered urine normalized with water standards showed a bias in the δ(2)H values that was corrected when calibration was performed with urine standards. At a δ(2)H value of 1101.4‰, the accuracy increased from -11.9 to -0.2 δ‰ (V500) and from -3.8 to 0.4 δ‰ (V6). The TBW errors were greatest with V500 and water calibration (1.20%) and lowest with V6 and urine calibration (0.34%; preparation-by-calibration interaction p = 0.027). For the δ(18)O values the accuracy of enrichments and TBW were not affected whatever preparations and normalization were used. The average TEE was not affected but the variability increased from 0.6 to 2.7% versus cryogenic distillation. CONCLUSIONS: Cryogenic distillation remains the gold standard for small sample size experiments where small changes in TEE are to be detected. Filtration offers an alternative for large-scale experiments. When the body composition is derived from (2)H2O dilution, it is strongly recommended that urine standards should be used to eliminate the effect of filtration.

Improved recovery of Listeria monocytogenes from stainless steel and polytetrafluoroethylene surfaces using air/water ablation.

AIMS: To develop a gentle ablation technique to recover Listeria monocytogenes biofilms from stainless steel (SS) and polytetrafluoroethylene (PTFE) surfaces by using compressed air and water injection. METHODS AND RESULTS: Biofilms were grown for 4, 24 and 48 h or 7 days and a compressed air and water flow at 2, 3 and 4 bars was applied for cell removal. Collected cells were quantified for total/dead by staining with SYTO 9/PI double staining and cultivable populations were determined by plating onto brain heart infusion (BHI) agar, while coupon surfaces also were stained with DAPI to quantify in situ the remaining cells. The recovery efficiency was compared to that of conventional swabbing. Results showed that the air/water ablation is able to collect up to 98·6% of cells from SS surfaces while swabbing only recovered 11·2% of biofilm. Moreover, air/water ablation recovered 99·9% of cells from PTFE surfaces. CONCLUSIONS: The high recovery rate achieved by this technique, along with the fact that cells were able to retain membrane integrity and cultivability, indicate that this device is suitable for the gentle recovery of viable L. monocytogenes biofilm cells. SIGNIFICANCE AND IMPACT OF THE STUDY: This work presents a highly efficient technique to remove, collect and quantify L. monocytogenes from surfaces commonly used in the food industry, which can thus serve as an important aid in verifying cleaning and sanitation as well as in reducing the likelihood of cross-contamination events.

A socio-ecological approach promoting physical activity and limiting sedentary behavior in adolescence showed weight benefits maintained 2.5 years after intervention cessation.

BACKGROUND: Obesity in youth remains a major public health issue. Yet no effective long-term preventive strategy exists. We previously showed that a school-based socio-ecological approach targeting behavior and social/environmental influences on physical activity (PA) prevented 4-year excessive weight gain in 12-year olds. In this study, we investigated if this efficacy persists 30 months after intervention cessation. METHODS AND FINDINGS: The program targeted students, family, school and the living environment to promote/support PA and prevent sedentary behavior (SB). A total of 732 students from eight randomized middle schools completed the 4-year trial. At the 30-month post-trial follow-up, body mass index (BMI), fat mass index (FMI), leisure PA (LPA), home/school/workplace active commuting, TV/video time (TVT), and attitudes toward PA were measured in 531 adolescents. The beneficial effects of the intervention on the excess BMI increase (+0.01 vs +0.34 kg m(-2) in the intervention and control groups, respectively) and on the overweight incidence in initially non-overweight students (4.3% vs 8.6%; odds ratio=0.48 (95% confidence interval: 0.23-1.01)) were maintained at the post-trial follow-up. LPA was not maintained at the level achieved during the trial. However, we still observed a prevention of the age-related decrease of the adolescents' percentage reporting regular LPA (-14.4% vs -26.5%) and a higher intention to exercise in the intervention group. The intervention promoted lower TVT (-14.0 vs +13.6 min per day) and higher active commuting changes (+11.7% vs -4.8%). Trends in higher BMI reduction in students with high initial TVT and in the least wealthy group were noted. TVT changes throughout the follow-up predicted excess BMI and FMI changes. CONCLUSIONS: Long-term multilevel approach targeting PA and SB prevents excessive weight gain up to 30 months after intervention cessation. The efficacy may be higher in the most sedentary and least wealthy adolescents. Healthy PA-related behavior inducing long-lasting weight effects can be promoted in youth providing that an ecological approach is introduced in the prevention strategy.

Thermal and morphometric correlates of the extremely low rate of energy use in a wild frugivorous primate, the Mayotte lemur.

Primates spend on average half as much energy as other placental mammals while expressing a wide range of lifestyles. However, little is known about how primates adapt their rate of energy use in the context of natural environmental variations. Using doubly labelled water, behavioral and accelerometric methods, we measured the total energy expenditure (TEE) and body composition of a population of Eulemur fulvus (N = 12) living in an agroforest in Mayotte. We show that the TEE of this medium-sized cathemeral primate is one of the lowest recorded to date in eutherians. Regression models show that individual variation in the rate of energy use is predicted by fat-free mass, body size, thigh thickness and maximum temperature. TEE is positively correlated with increasing temperature, suggesting that thermoregulation is an important component of the energy budget of this frugivorous species. Mass-specific TEE is only 10% lower than that of a closely related species previously studied in a gallery forest, consistent with the assertion that TEE varies within narrow physiological limits. As lemur communities include many species with unique thermoregulatory adaptations, circadian and/or seasonal temperature variations may have constituted a major selective pressure on the evolution of lemur metabolic strategies.

Raman-scattering measurements and theory of the energy-momentum spectrum for underdoped Bi2Sr2CaCuO(8+δ) superconductors: evidence of an s-wave structure for the pseudogap.

We reveal the full energy-momentum structure of the pseudogap of underdoped high-Tc cuprate superconductors. Our combined theoretical and experimental analysis explains the spectral-weight suppression observed in the B2g Raman response at finite energies in terms of a pseudogap appearing in the single-electron excitation spectra above the Fermi level in the nodal direction of momentum space. This result suggests an s-wave pseudogap (which never closes in the energy-momentum space), distinct from the d-wave superconducting gap. Recent tunneling and photoemission experiments on underdoped cuprates also find a natural explanation within the s-wave pseudogap scenario.

Transepithelial heme-iron transport: effect of heme oxygenase overexpression.

BACKGROUND: Heme iron is found in the diet mainly in the form of hemoglobin and myoglobin. It is known that heme iron (heme-Fe) and inorganic iron are absorbed differently. Intracellularly, heme oxygenase-1 (HO1) participates in the cleavage of the heme ring producing biliverdin, CO and ferrous iron. Iron released from heme becomes part of labile iron pool, and it can be stored in ferritin or released through the basolateral membrane. The mechanism by which heme-Fe is metabolized within cells is not completely understood. OBJECTIVE: This study focused on the uptake and transport of heme iron and on the role of heme oxygenase-1 on heme iron metabolism. DESIGN: Caco-2 cells were incubated with different concentrations of heme-Fe. A full-length heme oxygenase-1 cDNA was expressed in Caco-2 cells and intracellular iron and heme-Fe content, heme uptake, heme and iron transport and heme oxygenase-1 immunolocalization were assessed in these cells. RESULTS: Heme-Fe was bioavailable and induced an intracellular increase in iron, ferritin and HO1 levels and a decrease in DMT1 expression. In cells overexpressing HO1, heme-Fe uptake and transepithelial Fe transport was higher than in controls. Most heme-Fe was metabolized to free iron, most of which was found mainly in the basolateral chamber. However, there is a fraction of heme that is delivered intact to the basolateral side. In a high heme-Fe condition, HO1 is found near the plasma membrane. CONCLUSIONS: These results suggest that heme oxygenase-1 catabolizes most of the heme-Fe and favors iron influx and efflux in intestinal cells.

[Genotyping of blood group systems at the CNRGS. I: FY, JK, MNS systems]. / Génotypage des systèmes de groupe sanguin d'intérêt transfusionnel au CNRGS. I: les systèmes FY, JK, MNS.

AIM OF THE STUDY: Determination of blood group antigens from data obtained by using molecular methods (genotyping) has become an indispensable tool in the specialized immunohematology laboratories. The French National Reference Centre for Blood group typing (CNRGS) routinely performs genotyping of the FY, JK and MNS system (common genotyping), providing a phenotype deduced from genotyping data for FY1, FY2, JK1, JK2, MNS3 and MNS4 antigens. PATIENTS AND METHODS: We performed a study to evaluate the common genotyping prescriptions referred to the CNRGS over the last three years. RESULTS: Between February 2006 and February 2009, the CNRGS performed 2392 genotyping, including 981 common genotyping. Analysis of 172 common genotyping performed in 2008 showed that 63.8% of the prescriptions expressed a genotyping demand. Of the latter, 42.7% were genotyping prescriptions only, whereas 57.2% were prescriptions of genotyping associated with alloantibody identification. All prescriptions refer to blood group genotyping indications issued from guidelines, with no incorrect prescription, that are patients transfused within four months before blood sampling in 63.6% of cases or a positive direct antiglobulin test in 24.5% of cases. Lastly, 36% of the blood samples referred to the CNRGS had no genotyping prescription. Yet, common genotyping was performed by the CNRGS to get complete immunohematology data for antibody identification. CONCLUSION: Usefulness of blood group genotyping in specialized immunohematology laboratories is obvious. However, the strategy for implementation of molecular methods remains to be defined. Use of high-throughput DNA analysis should change our way of working.

Successful overweight prevention in adolescents by increasing physical activity: a 4-year randomized controlled intervention.

BACKGROUND: Population-based studies directed at promoting physical activity in youth have shown limited success in obesity prevention. OBJECTIVE: To assess whether an intervention integrating environmental changes to induce sustained changes in physical activity, prevents overweight in adolescents. DESIGN: Four-year randomized trial started in 2002 in eight middle schools of Eastern France. The intervention, randomized at school level, was designed to promote physical activity by changing attitudes through debates and attractive activities, and by providing social support and environmental changes encouraging physical activity. SUBJECTS: Nine hundred and fifty four 12-year-old six-graders. MEASUREMENTS: Body mass index (BMI), body composition, physical activity by questionnaire, plasma lipids and glucose, insulin resistance. RESULTS: Intervention students had a lower increase in BMI (P=0.01) and age- and gender-adjusted BMI (P<0.02) over time than controls. The differences across groups of the age- and gender-adjusted BMI changes (95% confidence interval (CI)) were -0.29 (-0.51; -0.07) kg/m2 at 3 years, -0.25 (-0.51; 0.01) kg/m2 at 4 years. An interaction with baseline weight status was noted. The intervention had a significant effect throughout the study in initially non-overweight adolescents (-0.36 (-0.60;-0.11) kg/m2 for adjusted BMI at 4 years), corresponding to a lower increase in fat mass index (P<0.001). In initially overweight adolescents, the differences observed across groups at 2 years (-0.40 (-0.94; 0.13) kg/m2 for adjusted BMI) did not persist over time. At 4 years, 4.2% of the initially non-overweight adolescents were overweight in the intervention schools, 9.8% in the controls (odds ratio=0.41 (0.22; 0.75); P<0.01). Independent of initial weight status, compared with controls, intervention adolescents had an increase in supervised physical activity (P<0.0001), a decrease of TV/video viewing (P<0.01) and an increase of high-density cholesterol concentrations (P<0.0001). CONCLUSION: Enhancing physical activity with a multilevel program prevents excessive weight gain in non-overweight adolescents. Our study provides evidence that prevention of obesity in youth is feasible.

[Isolated infarct of the corpus callosum: a misleading appearance]. / Infarctus isolé du corps calleux: un aspect trompeur.

We report here the case of an isolated corpus callosum infarct in a 48-year-old woman. Characteristics of this unusual condition are illustrated by multiple imaging modalities on follow-up. We discuss the pathophysiology of this rare entity and the more important differential diagnoses.

Prior automatic posture and activity identification improves physical activity energy expenditure prediction from hip-worn triaxial accelerometry.

Accelerometry is increasingly used to quantify physical activity (PA) and related energy expenditure (EE). Linear regression models designed to derive PAEE from accelerometry-counts have shown their limits, mostly due to the lack of consideration of the nature of activities performed. Here we tested whether a model coupling an automatic activity/posture recognition (AAR) algorithm with an activity-specific count-based model, developed in 61 subjects in laboratory conditions, improved PAEE and total EE (TEE) predictions from a hip-worn triaxial-accelerometer (ActigraphGT3X+) in free-living conditions. Data from two independent subject groups of varying body mass index and age were considered: 20 subjects engaged in a 3-h urban-circuit, with activity-by-activity reference PAEE from combined heart-rate and accelerometry monitoring (Actiheart); and 56 subjects involved in a 14-day trial, with PAEE and TEE measured using the doubly-labeled water method. PAEE was estimated from accelerometry using the activity-specific model coupled to the AAR algorithm (AAR model), a simple linear model (SLM), and equations provided by the companion-software of used activity-devices (Freedson and Actiheart models). AAR-model predictions were in closer agreement with selected references than those from other count-based models, both for PAEE during the urban-circuit (RMSE = 6.19 vs 7.90 for SLM and 9.62 kJ/min for Freedson) and for EE over the 14-day trial, reaching Actiheart performances in the latter (PAEE: RMSE = 0.93 vs. 1.53 for SLM, 1.43 for Freedson, 0.91 MJ/day for Actiheart; TEE: RMSE = 1.05 vs. 1.57 for SLM, 1.70 for Freedson, 0.95 MJ/day for Actiheart). Overall, the AAR model resulted in a 43% increase of daily PAEE variance explained by accelerometry predictions. NEW & NOTEWORTHY Although triaxial accelerometry is widely used in free-living conditions to assess the impact of physical activity energy expenditure (PAEE) on health, its precision and accuracy are often debated. Here we developed and validated an activity-specific model which, coupled with an automatic activity-recognition algorithm, improved the variance explained by the predictions from accelerometry counts by 43% of daily PAEE compared with models relying on a simple relationship between accelerometry counts and EE.

Pain and Vertebral Dysfunction in Dry Immersion: A Model of Microgravity Simulation Different from Bed Rest Studies.

BACKGROUND: Astronauts frequently experience back pain during and after spaceflight. The aim of this study was to utilize clinical methods to identify potential vertebral somatic dysfunction (VD) in subjects exposed to dry immersion (DI), a model of microgravity simulation. METHOD: The experiment was performed in a space research clinic, respecting all the ethical rules, with subjects completing three days of dry immersion (n = 11). Assessments of VD, spine height, and back pain were made before and after simulated microgravity. RESULTS: Back pain was present in DI with great global discomfort during the entire protocol. A low positive correlation was found (Pearson r = 0.44; P < 0.001) between VD before DI and pain developed in the DI experiment. CONCLUSIONS: There is a specific location of pain in both models of simulation. Our analysis leads to relativizing constraints on musculoskeletal system in function of simulation models. This study was the first to examine manual palpation of the spine in a space experience. Additionally, osteopathic view may be used to select those individuals who have less risk of developing back pain.

Helper-dependent vector transmission of plant viruses.

A variety of noncirculatively transmitted viruses have evolved a vector transmission strategy that involves, in addition to virions, virus-encoded proteins that are not constituents of virions. These "helpers" and the genes encoding them have been characterized for viruses in the genera Potyvirus and Caulimovirus. Several lines of evidence support the hypothesis that these helpers act by mediating retention of virions in regions of the vector's alimentary tract from which they subsequently can be egested to initiate an infection. The possible advantage this convergently evolved strategy could confer to noncirculatively transmitted virus quasispecies is discussed.

Fuel homeostasis during physical inactivity induced by bed rest.

The consequences of physical inactivity on fuel homeostasis were evaluated during 7 days of head-down bed rest (HDBR), a model mimicking weightlessness. Eight men (32.4 +/- 1.9 yr; body mass index, 23.9 +/- 0.7 kg/m2) and eight women (27.9 +/- 0.9 yr; body mass index, 20.9 +/- 0.6 kg/m2) underwent an oral glucose tolerance test (OGTT; 1 g/kg) before and after HDBR. The glucose load was labeled with 13C and associated with D-[6,6-2H2] glucose infusion, indirect calorimetry, breath tests, and plasma measurements to determine the glucose turnover and biodisponibility, substrate oxidation, and endocrine responses. Body composition was assessed using H2(18)O dilution. In addition, hormones were measured in daily blood and 24-h urine samples. No change in body composition was noted. Daily fasting insulin increased during HDBR (men, 34%; women, 26%), as did the insulin to glucose ratio (men, 30%; women, 25%). The normetanephrine level dropped (men, 30%; women, 16%), but metanephrine was unchanged. During OGTTs, the insulin response was increased after HDBR (men, 47%; women, 67%), whereas plasma glucose levels were similar. Nonesterified fatty acids and beta-hydroxybutyrate levels were lower. Endogenous glucose production dropped (28%), and exogenous glucose oxidation increased (28%) only in men. Resting energy expenditure was unchanged, but nonproteic respiratory quotient increased (men, 10%; women, 14%). Basal levels of lipid oxidation dropped in both sexes (approximately 90%), but those of carbohydrate oxidation increased in men (40%); as did lipogenesis in women (570%). In response to OGTTs, lipid oxidation was 80% reduced in both sexes after HDBR, but carbohydrate oxidation increased (25%) in men. Lipogenesis occurred in men (304%) and women (74%), but the latter had higher absolute levels. Therefore, 7 days of HDBR resulted in 1) reduced sympathetic activity, 2) insulin resistance suggested at the muscle level in men and at both the muscle and liver levels in women, 3) no changes in glucose biodisponibility, suggesting no alterations in the gastrointestinal function, and 4) a shift toward carbohydrate oxidation in men and a net lipogenesis in women. Such results suggest gender differences in response to sedentary life style and warrant further analysis.