Toward Exercise Guidelines for Optimizing Fat Oxidation During Exercise in Obesity: A Systematic Review and Meta-Regression.

BACKGROUND: Exercise training performed at maximal fat oxidation (FATmax) is an efficient non-pharmacological approach for the management of obesity and its related cardio-metabolic disorders. OBJECTIVES: Therefore, this work aimed to provide exercise intensity guidelines and training volume recommendations for maximizing fat oxidation in patients with obesity. METHODS: A systematic review of original articles published in English, Spanish or French languages was carried out in EBSCOhost, PubMed and Scopus by strictly following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Those studies that analyzed maximal fat oxidation (MFO) and FATmax in patients with obesity (body fat > 25% for men; > 35% for women) by calculating substrate oxidation rates through indirect calorimetry during a graded exercise test with short-duration stages (< 10 min) were selected for quantitative analysis. The accuracy of relative oxygen uptake (% peak oxygen uptake [%[Formula: see text]O2peak]) and relative heart rate (% peak heart rate [%HRpeak]) for establishing FATmax reference values was investigated by analyzing their intra-individual and inter-study variation. Moreover, cluster analysis and meta-regression were used for determining the influence of biological factors and methodological procedures on MFO and FATmax. RESULTS: Sixty-four manuscripts were selected from 146 records; 23 studies only recruited men (n = 465), 14 studies only evaluated women (n = 575), and 27 studies included individuals from both sexes (n = 6434). The majority of the evaluated subjects were middle-aged adults (aged 40-60 y; 84%) with a poor cardiorespiratory fitness (≤ 43 mL·kg-1·min-1; 81%), and the reported MFO ranged from 0.27 to 0.33 g·min-1. The relative heart rate at FATmax (coefficient of variation [CV]: 8.8%) showed a lower intra-individual variation compared with relative oxygen uptake (CV: 17.2%). Furthermore, blood lactate levels at FATmax ranged from 1.3 to 2.7 mmol·L-1 while the speed and power output at FATmax fluctuated from 4 to 5.1 km·h-1 and 42.8-60.2 watts, respectively. Age, body mass index, cardiorespiratory fitness, FATmax, the type of ergometer and the stoichiometric equation used to calculate the MFO independently explained MFO values (R2 = 0.85; p < 0.01). The MFO in adolescents was superior in comparison with MFO observed in young and middle-aged adults. On the other hand, the MFO was higher during treadmill walking in comparison with stationary cycling. Body fat and MFO alone determined 29% of the variation in FATmax (p < 0.01), noting that individuals with body fat > 35% showed a heart rate of 61-66% HRpeak while individuals with < 35% body fat showed a heart rate between 57 and 64% HRpeak. Neither biological sex nor the analytical procedure for computing the fat oxidation kinetics were associated with MFO and FATmax. CONCLUSION: Relative heart rate rather than relative oxygen uptake should be used for establishing FATmax reference values in patients with obesity. A heart rate of 61-66% HRpeak should be recommended to patients with > 35% body fat while a heart rate of 57-64% HRpeak should be recommended to patients with body fat < 35%. Moreover, training volume must be higher in adults to achieve a similar fat oxidation compared with adolescents whereas exercising on a treadmill requires a lower training volume to achieve significant fat oxidation in comparison with stationary cycling.

Eocene intra-plate shortening responsible for the rise of a faunal pathway in the northeastern Caribbean realm.

Intriguing latest Eocene land-faunal dispersals between South America and the Greater Antilles (northern Caribbean) has inspired the hypothesis of the GAARlandia (Greater Antilles Aves Ridge) land bridge. This landbridge, however, should have crossed the Caribbean oceanic plate, and the geological evolution of its rise and demise, or its geodynamic forcing, remain unknown. Here we present the results of a land-sea survey from the northeast Caribbean plate, combined with chronostratigraphic data, revealing a regional episode of mid to late Eocene, trench-normal, E-W shortening and crustal thickening by ∼25%. This shortening led to a regional late Eocene-early Oligocene hiatus in the sedimentary record revealing the location of an emerged land (the Greater Antilles-Northern Lesser Antilles, or GrANoLA, landmass), consistent with the GAARlandia hypothesis. Subsequent submergence is explained by combined trench-parallel extension and thermal relaxation following a shift of arc magmatism, expressed by a regional early Miocene transgression. We tentatively link the NE Caribbean intra-plate shortening to a well-known absolute and relative North American and Caribbean plate motion change, which may provide focus for the search of the remaining connection between 'GrANoLA' land and South America, through the Aves Ridge or Lesser Antilles island arc. Our study highlights the how regional geodynamic evolution may have driven paleogeographic change that is still reflected in current biology.

Trends in hospitalisation rates for inflammatory bowel disease in western versus newly industrialised countries: a population-based study of countries in the Organisation for Economic Co-operation and Development.

BACKGROUND: Hospitalisation rates for inflammatory bowel disease (IBD) vary across the world. We aimed to investigate temporal patterns of hospitalisation for IBD in member countries of the Organisation for Economic Co-operation and Development (OECD). METHODS: From the OECD database, we assessed IBD-related hospitalisation rates (expressed as annual rates per 100 000 inhabitants) for 34 countries from 1990 to 2016. We calculated mean hospitalisation rates for the period 2010-15 and used joinpoint regression models to calculate average annual percentage changes with 95% CIs. FINDINGS: Mean hospitalisation rates for IBD from 2010 to 2015 were highest in North America (eg, 33·9 per 100 000 in the USA), Europe (eg, 72·9 per 100 000 in Austria), and Oceania (eg, 31·5 per 100 000 in Australia). Hospitalisation rates for IBD were stabilising or decreasing over time in many countries in these regions but increasing in others. Countries in Asia and Latin America and the Caribbean had the lowest IBD-related hospitalisation rates but the greatest increases in rates over time. For example, Turkey had an annual hospitalisation rate of 10·8 per 100 000 inhabitants and an average annual percentage change of 10·4% (95% CI 5·2-15·9). Similarly, Chile had an annual hospitalisation rate of 9·0 per 100 000 inhabitants and an average annual percentage change of 5·9% (4·9-7·0). INTERPRETATION: Hospitalisation rates for IBD are high in western countries but are typically stabilising or decreasing, whereas rates in many newly industrialised countries are rapidly increasing, which reflects the known increase in IBD prevalence in these countries. Potential explanations for these trends include changes in the epidemiology of IBD, health-care delivery, and infrastructure in these countries, as well as overall country-specific patterns in hospitalisations and differences between countries in data collection methods. FUNDING: None.

Chemical and pharmacognostical characterization of two Malaysian plants both known as Ajisamat

Ajisamat, an herb commonly used as an aphrodisiac in the Malaysian traditional medicine, corresponds to two different species from different families - Salacia macrophylla Blume, Celastraceae, and Prismatomeris glabra (Korth.) Valeton, Rubiaceae. Macromorphological inspection of the vegetative parts both plants reveals only a slight difference in the arrangement of the petioles. Microscopic investigation of the plants roots used as crude drugs revealed however distinctive anatomical features. Prismatic calcium oxalate crystals and banded paratracheal parenchyma are characteristics of S. macrophylla while P. glabra displays an abundance as crystals. Other features such as vessels diameters and arrangements are also of diagnostic importance. Some of these characters were also identified in the powder of thes e plant materials and proposed for diagnostic purpose. The values for extraction of ethanol and water as well as total ash, acid-insoluble ash, water-soluble ash and sulfated ash were determined for both plants. Phytochemical studies were carried out on hexane and chloroform extracts of S. macrophylla and methanolic extract of P. glabra. S. macrophylla was shown to contain highly oxidized pentacyclic triterpenes while P. glabra contains anthraquinones. The pharmacognostical and hytochemical information can be utilised as the identification tools for Salacia macrophylla and Prismatomeris glabra .

Exercise hemorheology: classical data, recent findings and unresolved issues.

The present review focuses on the past and recent knowledge in the field of exercise hemorheology and presents some unresolved issues for opening discussion. Acute exercise is associated with a rise in hematocrit which results in an increase in blood viscosity. Whereas increased blood viscosity was previously viewed as having negative consequences for cardiovascular function and aerobic performance, recent findings suggest dynamic changes in blood viscosity might be useful for vascular function during exercise by increasing nitric oxide production. Other determinants of blood viscosity are altered by exercise (e.g., decreased red blood cell deformability, increased red blood cell aggregation and plasma viscosity) and may, independent of the associated effect on blood viscosity, directly modulate aerobic capacity. However, the data published on the effects of exercise on the hemorheology are not consistent, with some studies showing decreased, unchanged, or increased red blood cell deformability/aggregation when compared with rest. These discrepancies seem to be related to the exercise protocol investigated, the population tested or the methodogy utilized for hemorheological measurements. Finally, this review focuses on the effects of exercise training (i.e. chronic physical activity) on the hemorheological profile of healthy individuals and patients with cardiovascular and metabolic disorders.

Maximal exercise and lactate do not change red blood cell aggregation in well trained athletes.

Exercise and lactate usually change blood rheology, particularly red blood cell (RBC) deformability. The effect of lactate on RBC aggregation is unknown. The present study tested the in vivo effects of exercise on both lactate and RBC aggregation and the in vitro effects of lactate on RBC aggregation. Thirteen well trained athletes performed a progressive and maximal exercise test during which blood was sampled at rest, at 50% of maximal exercise, and at maximal exercise. RBC aggregation was assessed with the Myrenne aggregometer which gives two indexes of RBC aggregation: "M" (aggregation during stasis after shearing at 600 s(-1)) and "M1" (facilitated aggregation at low shear rate after shearing at 600 s(-1)). A part of the resting blood sample was also reserved to test the in vitro effects of three lactate concentrations (2, 4 and 10 mM). The lactate solutions were described in a previous study (P. Connes, D. Bouix, G. Py, C. Préfaut, J. Mercier, J.F. Brun and C. Caillaud, Opposite effects of in vitro lactate on erythrocyte deformability in athletes and untrained subjects, Clin. Hemorheol. Microcirc. 31 (2004), 311-318). The results demonstrated that M and M1 were unchanged with exercise and lactate. Therefore, lactate is able to change RBC deformability but not RBC aggregation.

Environnement et systeme immunitaire: application au domaine de l'auto-immunite / Environment and immunitary system: application to the extent of auto immunity

Le reseau idiotypique, structure hierarchisee et regulee, est capable d'integrer en "images dynamiques"les informations du non-soi (virus, bacterie... de l'environnement) et du soi. La survenue de pathologies auto-immunes peut etre consideree comme une deviation ou une alteration de la reconnaissance de ce message par le systeme immunitaire de sujets predisposes. Les superantigenes bacteriens ou... (AU)