Aerobic and functional capacities in a selected active population of European octogenarians

Master athletes are often considered to represent the ideal rate of decline of aerobic function; however, most of the studies interested in active elderly people are often limited to people younger than 75. We aimed to determine the physiological adaptations and aerobic fitness in a selected European population of active octogenarians during maximal and submaximal exercise tests. Aerobic capacity was measured during maximal incremental tests on treadmill (TR) and cycle-ergometer (CE) and functional capacity during a 6-minute walk test (6-MWT) in 17 subjects aged 81.2 +/- 0.8 years. Pulmonary gas exchange and heart rate (HR) were continuously measured during the different exercise tests. Maximal oxygen consumption (V.O (2max)) on TR and CE was significantly higher than predicted values (TR: 28.7 +/- 1.2 vs. 17 +/- 0.5 ml . kg (-1) . min (-1); CE: 23 +/- 1.2 vs. 16 +/- 0.6 ml . kg (-1) . min (-1) for measured and predicted values respectively). V.O (2max) and HR (max), as well as V.O (2) and HR at the ventilatory threshold (V.O (2)T (V.E) and HR T (V.E)) were significantly higher on TR than on CE (HR (max): 144 +/- 4 vs. 138 +/- 4 bpm; V.O (2)T (V.E): 22.5 +/- 0.8 vs. 17.7 +/- 0.9 ml . kg (-1) . min (-1) for TR and CE respectively). V.O (2)T (V.E) and HR T (V.E) on TR were equivalent to V.O (2) and HR measured during the 6-MWT. HR T (V.E) on TR and mean HR during the 6-MWT were strongly correlated (R = 0.82, p < 0.01). Maintenance of regular physical activity provides high aerobic fitness, in octogenarians, as was shown by the higher values of our subjects in comparison to predicted values. Moreover, the close relation between the intensity developed at T (V.E) on TR and 6-MWT could support the idea that a walk test is a submaximal test performed at high intensity that could provide a basis for exercise prescription in an individualized manner in active elderly people.

Effects of two types of fatigue on the VO(2) slow component.

The aim of the study was to test the hypothesis of the involvement of type II fibres in the V.O (2) slow component phenomenon by using two prior fatiguing protocols on the knee extensor muscles. Nine subjects performed three constant-load cycling exercises at a work rate corresponding to 80 % of their V.O (2) max: (i) preceded by a 20-min fatiguing protocol using electromyostimulation (EMS), (ii) preceded by a 20-min fatiguing protocol using voluntary contractions (VOL), and (iii) without fatiguing protocol (NFP). Voluntary and evoked neuromuscular properties of the knee extensor muscles were tested before (PRE) and after (POST) the two fatiguing protocols. Results show a significant reduction in voluntary force after both fatiguing protocols (-19.9 % and -11.8 %, in EMS and VOL, respectively p<0.01). After EMS, this decrease was greater than after VOL (p<0.05) and was combined with a slackening of muscle contractile properties which was absent after VOL (p<0.05). Regarding the effects on oxygen uptake kinetics, the appearance of the slow component was delayed after EMS and its amplitude was lower than those obtained in VOL and NFP conditions (0.48+/-0.07 vs. 0.75+/-0.09 and 0.69+/-0.08 L . min (-1), respectively; p<0.05). It can thus be concluded that exercises dedicated to preferentially fatiguing type II fibres may alter V.O (2) kinetics.

Dynamic responses of oxygen uptake at the onset and end of moderate and heavy exercise in trained subjects.

Inconsistencies about dynamic asymmetry between the on- and off-transient responses in VO2 are found in the literature. Therefore the purpose of this study was to examine VO2 on- and off-transients during moderate- and heavy-intensity cycling exercise in trained subjects. Ten men underwent an initial incremental test for the estimation of ventilatory threshold (VT) and, on different days, two bouts of square-wave exercise at moderate (<VT) and heavy (>VT) intensities. VO2 kinetics in exercise and recovery were better described by a single exponential model (<VT), or by a double exponential with two time delays (>VT). For moderate exercise, we found a symmetry of VO2 kinetics between the on- and off-transients (i.e., fundamental component), consistent with a system manifesting linear control dynamics. For heavy exercise, a slow component superimposed on the fundamental phase was expressed in both the exercise and recovery, with similar parameter estimates. But the on-transient values of the time constant were appreciably faster than the associated off-transient, and independent of the work rate imposed (<VT and >VT). Our results do not support a dynamically linear system model of VO2 during cycling exercise in the heavy-intensity domain.

Dynamic responses of O2 uptake at the onset and end of exercise in trained subjects.

Inconsistencies about dynamic asymmetry between the on- and off-transient responses in .VO2 are found in the literature. Therefore the purpose of this study was to examine .VO2on- and off-transients during moderate- and heavy-intensity cycling exercise in trained subjects. Ten men underwent an initial incremental test for the estimation of ventilatory threshold (VT) and, on different days, two bouts of square-wave exercise at moderate (<VT) and heavy (>VT) intensities. .VO2 kinetics in exercise and recovery were better described by a single exponential model (<VT) or by a double exponential with two time delays (>VT). For moderate exercise, we found a symmetry of .VO2 kinetics between the on- and off-transients (i.e., fundamental component), consistent with a system manifesting linear control dynamics. For heavy exercise, a slow component superimposed on the fundamental phase was expressed in both the exercise and recovery, with similar parameter estimates. But the on-transient values of the time constant were appreciably faster than the associated off-transient, and independent of the work rate imposed (<VT and >VT). Our results do not support a dynamically linear system model of .VO2 during cycling exercise in the heavy-intensity domain.

Alcohol attributable burden of incidence of cancer in eight European countries based on results from prospective cohort study.

Objective To compute the burden of cancer attributable to current and former alcohol consumption in eight European countries based on direct relative risk estimates from a cohort study. Design Combination of prospective cohort study with representative population based data on alcohol exposure. Setting Eight countries (France, Italy, Spain, United Kingdom, the Netherlands, Greece, Germany, Denmark) participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Participants 109 118 men and 254 870 women, mainly aged 37-70. Main outcome measures Hazard rate ratios expressing the relative risk of cancer incidence for former and current alcohol consumption among EPIC participants. Hazard rate ratios combined with representative information on alcohol consumption to calculate alcohol attributable fractions of causally related cancers by country and sex. Partial alcohol attributable fractions for consumption higher than the recommended upper limit (two drinks a day for men with about 24 g alcohol, one for women with about 12 g alcohol) and the estimated total annual number of cases of alcohol attributable cancer. Results If we assume causality, among men and women, 10% (95% confidence interval 7 to 13%) and 3% (1 to 5%) of the incidence of total cancer was attributable to former and current alcohol consumption in the selected European countries. For selected cancers the figures were 44% (31 to 56%) and 25% (5 to 46%) for upper aerodigestive tract, 33% (11 to 54%) and 18% (−3 to 38%) for liver, 17% (10 to 25%) and 4% (−1 to 10%) for colorectal cancer for men and women, respectively, and 5.0% (2 to 8%) for female breast cancer. A substantial part of the alcohol attributable fraction in 2008 was associated with alcohol consumption higher than the recommended upper limit: 33 037 of 178 578 alcohol related cancer cases in men and 17 470 of 397 043 alcohol related cases in women. Conclusions In western Europe, an important proportion of cases of cancer can be attributable to alcohol consumption, especially consumption higher than the recommended upper limits. These data support current political efforts to reduce or to abstain from alcohol consumption to reduce the incidence of cancer.

Blood lipid and lipoprotein concentrations and colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition

Objective To examine the association between serum concentrations of total cholesterol, high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol, triglycerides, apolipoprotein A-I (apoA), apolipoprotein B and the incidence of colorectal cancer (CRC). Design Nested case–control study. Setting The study was conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC), a cohort of more than 520 000 participants from 10 western European countries. Participants 1238 cases of incident CRC, which developed after enrolment into the cohort, were matched with 1238 controls for age, sex, centre, follow-up time, time of blood collection and fasting status. Main outcome measures Serum concentrations were quantitatively determined by colorimetric and turbidimetric methods. Dietary and lifestyle data were obtained from questionnaires. Conditional logistic regression models were used to estimate incidence rate ratios (RRs) and 95% CIs which were adjusted for height, weight, smoking habits, physical activity, education, consumption of fruit, vegetables, meat, fish, alcohol, fibre and energy. Results After adjustments, the concentrations of HDL and apoA were inversely associated with the risk of colon cancer (RR for 1 SD increase of 16.6 mg/dl in HDL and 32.0 mg/dl in apoA of 0.78 (95% CI 0.68 to 0.89) and 0.82 (95% CI 0.72 to 0.94), respectively). No association was observed with the risk of rectal cancer. Additional adjustment for biomarkers of systemic inflammation, insulin resistance and oxidative stress or exclusion of the first 2 years of follow-up did not influence the association between HDL and risk of colon cancer. Conclusions These findings show that high concentrations of serum HDL are associated with a decreased risk of colon cancer. The mechanism behind this association needs further elucidation.

Alcohol intake and the risk of coronary heart disease in the Spanish EPIC

Background: The association between alcohol consumption and coronary heart disease (CHD) has been widely studied. Most of these studies have concluded that moderate alcohol intake reduces the risk of CHD. There are numerous discussions regarding whether this association is causal or biased. The objective of this paper is to analyse the association between alcohol intake and CHD risk in the Spanish cohort of the European Prospective Investigation into Cancer (EPIC). Methods: Participants from the EPIC Spanish cohort were included (15 630 men and 25 808 women). The median follow-up period was 10 years. Ethanol intake was calculated using a validated dietary history questionnaire. Participants with a definite CHD event were considered cases. A Cox regression model adjusted for relevant co-variables and stratified by age was produced. Separate models were carried out for men and women. Results: The crude CHD incidence rate was 300.6/100 000 person-years for men and 47.9/100 000 person-years for women. Moderate, high and very high consumption was associated with a reduced risk of CHD in men: hazard ratio 0.90 (95% CI 0.56 to 1.44) for former drinkers, 0.65 (95% CI 0.41 to 1.04) for low, 0.49 (95% CI 0.32 to 0.76) for moderate, 0.46 (95% CI 0.30 to 0.71) for high and 0.50 (95% CI 0.29 to 0.85) for very high consumers. A negative association was found in women, with p values above 0.05 in all categories. Conclusions: Alcohol intake in men aged 29–69 years was associated with a more than 30% lower CHD incidence. This study is based on a large prospective cohort study and is free of the abstainer error.

Toxoplasma gondii in animals used for human consumption

Food-borne toxoplasmosis in humans may result from exposure to different stages of Toxoplasma gondii, in particular from the ingestion of tissue cysts or tachyzoites contained in meat, primary offal (viscera) or meat-derived products of many different animals, or the ingestion of sporulated oocysts that are contained in the environment and may contaminate food and water. Although the potential for transmission of the parasite to humans via food has been known for several decades, it is not known which routes are most important from a public health point of view. It is likely that transmission of the parasite to humans is influenced not only by the potential contamination of various food sources, but also by the individual behaviour of consumers in different ethnic groups and geographical regions. Most current methods for detection of T. gondii in meat-producing animals, in products of animal origin, or in the environment are insufficient because they do not allow quantification of infectious stages. Hence, most studies report only qualitative data from which it is difficult to assess the true risk of infection in individual cases. There is a need for quantitative data so that efficient strategies to reduce food-borne transmission of T. gondii to humans can be developed.

Prevalence of acute toxoplasmosis infection among 41,112 pregnant women and the mother-to-child transmission rate in a public hospital in South Brazil

Untreated acute toxoplasmosis among pregnant women can lead to serious sequelae among newborns, including neurological impairment and blindness. In Brazil, the risk of congenital toxoplasmosis (CTox) has not been fully evaluated. Our aim was to evaluate trends in acute toxoplasmosis prevalence from 1998-2005, the incidence of CTox and the rate of mother-to-child transmission (MTCT). A cross-sectional study was undertaken to dentify patients who fit the criteria for acute toxoplasmosis during pregnancy. Exposed newborns were included in a historical cohort, with a median follow-up time of 11 months, to establish definite diagnosis of CTox. Diagnoses for acute infection in pregnancy and CTox were based on European Research Network on Congenital Toxoplasmosis criteria. In 41,112 pregnant women, the prevalence of acute toxoplasmosis was 4.8/1,000 women. The birth prevalence of CTox was 0.6/1,000 newborns [95% confidence interval (CI): 0.4-0.9]. During the follow-up study, 12 additional cases were detected, increasing the CTox rate to 0.9/1,000 newborns (95% CI: 0.6-1.3). Among the 200 newborns exposed to Toxoplasma gondii,there were 37 babies presenting diagnostic criteria of CTox, leading to an MTCT rate of 18.5% (95% CI: 13.4-24.6%). The additional cases identified during follow-up reinforce the need for serological monitoring during the first year of life, even in the absence of evidence of congenital infection at birth.

Consumption and portion sizes of tree nuts, peanuts and seeds in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts from 10 European countries

Tree nuts, peanuts and seeds are nutrient dense foods whose intake has been shown to be associated with reduced risk of some chronic diseases. They are regularly consumed in European diets either as whole, in spreads or from hidden sources (e.g. commercial products). However, little is known about their intake profiles or differences in consumption between European countries or geographic regions. The objective of this study was to analyse the population mean intake and average portion sizes in subjects reporting intake of nuts and seeds consumed as whole, derived from hidden sources or from spreads. Data was obtained from standardised 24-hour dietary recalls collected from 36 994 subjects in 10 different countries that are part of the European Prospective Investigation into Cancer and Nutrition (EPIC). Overall, for nuts and seeds consumed as whole, the percentage of subjects reporting intake on the day of the recall was: tree nuts = 4. 4%, peanuts = 2.3 % and seeds = 1.3 %. The data show a clear northern (Sweden: mean intake = 0.15 g/d, average portion size = 15.1 g/d) to southern (Spain: mean intake = 2.99 g/d, average portion size = 34.7 g/d) European gradient of whole tree nut intake. The three most popular tree nuts were walnuts, almonds and hazelnuts, respectively. In general, tree nuts were more widely consumed than peanuts or seeds. In subjects reporting intake, men consumed a significantly higher average portion size of tree nuts (28.5 v. 23.1 g/d, P<0.01) and peanuts (46.1 v. 35.1 g/d, P<0.01) per day than women. These data may be useful in devising research initiatives and health policy strategies based on the intake of this food group.

Evolutionary implications of a high selfing rate in the freshwater snail Lymnaea truncatula.

Self-compatible hermaphroditic organisms that mix self-fertilization and outcrossing are of great interest for investigating the evolution of mating systems. We investigate the evolution of selfing in Lymnaea truncatula, a self-compatible hermaphroditic freshwater snail. We first analyze the consequences of selfing in terms of genetic variability within and among populations and then investigate how these consequences along with the species ecology (harshness of the habitat and parasitism) might govern the evolution of selfing. Snails from 13 localities (classified as temporary or permanent depending on their water availability) were sampled in western Switzerland and genotyped for seven microsatellite loci. F(IS) (estimated on adults) and progeny array analyses (on hatchlings) provided similar selfing rate estimates of 80%. Populations presented a low polymorphism and were highly differentiated (F(ST) = 0.58). Although the reproductive assurance hypothesis would predict higher selfing rate in temporary populations, no difference in selfing level was observed between temporary and permanent populations. However, allelic richness and gene diversity declined in temporary habitats, presumably reflecting drift. Infection levels varied but were not simply related to either estimated population selfing rate or to differences in heterozygosity. These findings and the similar selfing rates estimated for hatchlings and adults suggest that within-population inbreeding depression is low in L. truncatula.

Le taux de détresse respiratoire du nouveau-né augmente, celui des césariennes aussi: et si ce n'était pas un hasard? [Respiratory distress of the neonate and the rate of caesarean section have increased over the last 30 years. Is there a link?]

Ces trente dernières années, on note en Suisse une augmentation significative de l'incidence du syndrome de détresse respiratoire (SDR) chez le nouveau-né (NN), touchant particulièrement les enfants avec un poids de naissance >2500 g. En même temps, le taux des césariennes (CS) s'est aussi accru. Une explication pour une éventuelle corrélation entre les deux évolutions est une augmentation en particulier des CS électives qui ont tendance à être planifiées à un terme précoce pour éviter la mise en travail spontanée. Suite à cela, le foetus est privé de différents mécanismes qui favorisent l'adaptation pulmonaire périnatale. Les bénéfices réels de la CS sur la morbidité tant foetale que maternelle ne doivent pas faire oublier que la CS est un facteur de risque pour le SDR du NN. Ce risque peut être diminué efficacement en planifiant une CS élective après 39 semaines révolues. In Switzerland, the rate of respiratory distress in neonates needing hospitalization has doubled over the last thirty years, concerning in particular babies weighing more than 2500 g. In the same time, the rate of Caesarean section (CS) has also multiplied. We suppose that a link between the two evolutions might be the increase of elective CS. They tend to be planned early at term to avoid the onset of spontaneous labour As a consequence, the foetus is deprived of different mechanisms helping pulmonary transition around birth. The potential benefits of CS regarding morbidity of foetus and mother should not overshadow that CS is a significant risk factor for respiratory problems of the neonate. This risk could be dramatically decreased by planning elective CS only after completed 39 weeks of gestation

Microbiological activities in moonmilk monitored using isothermal microcalorimetry (cave of Vers Chez le Brandt, Neuchatel, Switzerland)

Studies of the influence of microbial communities on calcium carbonate deposits mostly rely on classical or molecular microbiology, isotopic analyses, and microscopy. Using these techniques, it is difficult to infer microbial activities in such deposits. In this context, we used isothermal microcalorimetry, a sensitive and nondestructive tool, to measure microbial activities associated with moonmilk ex-situ. Upon the addition of diluted LB medium and other carbon sources to fresh moonmilk samples, we estimated the number of colony forming units per gram of moonmilk to be 4.8 3 105 6 0.2 3 105. This number was close to the classical plate counts, but one cannot assume that all active cells producing metabolic heat were culturable. Using a similar approach, we estimated the overall growth rate and generation time of the microbial community associated with the moonmilk upon addition of various carbon sources. The range of apparent growth rates of the chemoheterotrophic microbial community observed was between 0.025 and 0.067 h21 and generation times were between 10 and 27 hours. The highest growth rates were observed for citrate and diluted LB medium, while the highest carbon-source consumption rates were observed for low molecular weight organic acids (oxalate and acetate) and glycerol. Considering the rapid degradation of organic acids, glucose, and other carbon sources observed in the moonmilk, it is obvious that upon addition of nutrients during snow melting or rainfall these communities can have high overall activities comparable to those observed in some soils. Such communities can influence the physico-chemical conditions and participate directly or indirectly to the formation of moonmilk.

Experimentation and Stages of Acquisition for Tobacco Consumption in Spanish Adolescents

One area which has been largely neglected when studying the acquisition of addiction to smoking with thetranstheoretical model is whether the individual had previously experimented with smoking. The importance of includingthe experimentation variable was supported by this research