Upper Respiratory Tract Infections in Sport and the Immune System Response. A Review

Immunity is the consequence of a complex interaction between organs and the environment. It is mediated the interaction of several genes, receptors, molecules, hormones, cytokines, antibodies, antigens, and inflammatory mediators which in turn relate and influence the psychological health. The immune system response of heavily trained athletes resembles an even more complex conditions being theorized to follow a J or S shape dynamics at times. High training loads modify the immune response elevating the biological markers of immunity and the body susceptibility to infections. Heavy training and/or training in a cold environment increase the athletes' risk to develop Upper Respiratory Tract Infections (URTIs). Therefore, athletes, who are considered healthier than the normal population, are in fact more prone to infections of the respiratory tract, due to lowering of the immune system in the time frames subsequent heavy training sessions. In this revision we will review the behavioral intervention, including nutritional approaches, useful to minimize the "open window" effect on infection and how to cope with stressors and boost the immune system in athletes

Cycling training effects on fat metabolism blood parameters

BACKGROUND: Study the acute and middle term (4 weeks training) effect of cycling training on fat blood hematological parameters, urine, fatigue, and general health in recreational well-trained cyclists. METHODS: Nineteen cyclists underwent five blood sample collections: before and after an incremental maximal ramp test 7 days before day 0 (D-0); before and after 1 hour exhaustion trial test at baseline (D-0); and after 28 days of training (D-28). Age 34.5 years (\ub19.5); weight 74.87 kg (\ub16.6); height 177.3 cm (\ub15.2); BMI 26.3 (\ub14.9); VO2max 53.75 mL/kg/ min (\ub16.01); distance cycled 314.7 km/week (\ub1137.1). RESULTS: Acute effect was strong elevating WBC from 6.27\ub12.34 to 9.01\ub13.63 7103/\ub5L, an increase in LDL and total CHOL, in this respect, existing literature is controversial. No changes in body weight or blood pressure was observed after 1 month of regular training albeit lipid profile significantly improved, as well as GOT. CONCLUSIONS: Effect of a short incremental bout of exercise was to temporary elevated all the blood parameters except MCH and MCHC. A month of intensive training (distance cycled: 314.7\ub1137.1 km/week) significantly improved blood lipids profile with no permanent effect on WBC, blood pressure or body weight, but improved post effort lactate concentration and fatigue perception. Hematuria is confirmed to be a rare occurrence in recreational cyclists. Data can be useful for training monitoring and comparisons with similar groups of athletes, where there is a lack of information in literature and for comparing exercise effects

Nitric oxide can function as either a killer molecule or an antiapoptotic effector in cardiomyocytes

AbstractCaspase enzymes are a family of cysteine proteases that play a central role in apoptosis. Recently, it has been demonstrated that caspases can be S-nitrosylated and inhibited by nitric oxide (NO). The present report shows that in chick embryo heart cells (CEHC), NO donor molecules such as S-nitroso-N-acetylpenicillamine (SNAP), S-nitrosoglutathione, spermine-NO or sodium nitroprusside inhibit caspase activity in both basal and staurosporine-treated cells. However, the inhibitory effect of NO donors on caspase activity is accompanied by a parallel cytotoxic effect, that precludes NO to exert its antiapoptotic capability. N-Acetylcysteine (NAC) at a concentration of 10 mM blocks depletion of cellular glutathione and cell death in SNAP-treated CEHC, but it poorly affects the ability of SNAP to inhibit caspase activity. Consequently, in the presence of NAC, SNAP attenuates not only caspase activity but also cell death of staurosporine-treated CEHC. These data show that changes in the redox environment may inhibit NO-mediated toxicity, without affecting the antiapoptotic capability of NO, mediated by inhibition of caspase enzymes. NO may thus be transformed from a killer molecule into an antiapoptotic agent

Bone mineral density and hormonal status in adolescent athletic girls

The aim of this study was to determine the relationships of bone mineral density (BMD) and content (BMC) with selected fasting hormones in adolescents with different exercise training patterns. The participants were female athletes of weight-loaded (n=23) and weight-supported (n=24) sports, and 33 non-athletic girls aged 13–15 years. BMD (g/cm2) and BMC (g) at the femoral neck (FN) and lumbar spine (LS) were measured. Venous blood samples were drawn to determine the concentration of insulin-like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3), estradiol, visfatin, adiponectin, leptin, insulin, and glucose. After adjusting for age, height, and body mass, the relationships of BMD variables with IGF-1, IGF-1/IGFBP-3 molar ratio, estradiol, and leptin levels remained significant only in the weight-loaded sport group (r=0.41–0.60; p<0.05). Adiponectin was inversely correlated to FN and LS BMD and BMC (r=–0.47–0.62; p<0.05) in weight-supported sport group only, but after adjustments for age, height, and body mass, these associations disappeared. In this study, concentrations of visfatin, a fairly new adipocytokine, were not related to bone parameters in adolescent girls with different training patterns

Assessment of the Effects of Edible Microalgae in a Canine Gut Model

Microalgae are a source of bioactive compounds having recently been studied for their possible application as health-promoting ingredients. The aim of the study was to evaluate in an in vitro canine gut model the effects of four microalgae, Arthrospira platensis (AP), Haematococcus pluvialis (HP), Phaeodactylum tricornutum (PT) and Chlorella vulgaris (CV), on some fecal microbial populations and metabolites. The four microalgae were subjected to an in vitro digestion procedure, and subsequently, the digested biomass underwent colonic in vitro fermentation. After 6 h of incubation, PT increased propionate (+36%) and butyrate (+24%), and decreased total BCFA (-47%), isobutyrate (-52%) and isovalerate (-43%) and C. hiranonis (-0.46 log10 copies/75 ng DNA). After 24 h, PT increased propionate (+21%) and isovalerate (+10%), and decreased the abundance of Turicibacter spp. (7.18 vs. 6.69 and 6.56 log10 copies/75 ng DNA for CTRL vs. PT, respectively); moreover, after 24 h, CV decreased C. coccoides (-1.12 log10 copies/75 ng DNA) and Enterococcus spp. (-0.37 log10 copies/75 ng DNA). In conclusion, the microbial saccharolytic activities and the shift in fecal bacterial composition were less pronounced than expected, based on current literature. This study should be considered as a preliminary assessment, and future investigations are required to better understand the role of microalgae in canine nutrition

Influence of dietary protein and fructooligosaccharides on fecal fermentative end-products, fecal bacterial populations and apparent total tract digestibility in dogs

Background: Feeding dogs with diets rich in protein may favor putrefactive fermentations in the hindgut, negatively affecting the animal\u2019s intestinal environment. Conversely, prebiotics may improve the activity of healthpromoting bacteria and prevent bacterial proteolysis in the colon. The aim of this study was to evaluate the effects of dietary supplementation with fructooligosaccharides (FOS) on fecal microbiota and apparent total tract digestibility (ATTD) in dogs fed kibbles differing in protein content. Twelve healthy adult dogs were used in a 4 74 replicated Latin Square design to determine the effects of four diets: 1) Low protein diet (LP, crude protein (CP) 229 g/kg dry matter (DM)); 2) High protein diet (HP, CP 304 g/kg DM); 3) Diet 1+1.5 g of FOS/kg; 4) Diet 2+1.5 g of FOS/kg. The diets contained silica at 5 g/kg as a digestion marker. Differences in protein content were obtained using different amounts of a highly digestible swine greaves meal. Each feeding period lasted 28 d, with a 12 d wash-out in between periods. Fecal samples were collected from dogs at 0, 21 and 28 d of each feeding period. Feces excreted during the last five days of each feeding period were collected and pooled in order to evaluate ATTD. Results: Higher fecal ammonia concentrations were observed both when dogs received the HP diets (p<0. 001) and the supplementation with FOS (p<0.05). The diets containing FOS resulted in greater ATTD of DM, Ca, Mg, Na, Zn, and Fe (p<0.05) while HP diets were characterized by lower crude ash ATTD (p<0.05). Significant interactions were observed between FOS and protein concentration in regards to fecal pH (p<0. 05), propionic acid (p<0.05), acetic to propionic acid and acetic + n-butyric to propionic acid ratios (p<0.01), bifidobacteria (p<0.05)andATTDofCP(p<0.05)andMn(p<0.001). Conclusions: A relatively moderate increase of dietary protein resulted in higher concentrations of ammonia in canine feces. Fructooligosaccharides displayed beneficial counteracting effects (such as increased bifidobacteria) when supplemented in HP diets, compared to those observed in LP diets and, in general, improved the ATTD of several minerals

Evidence that AMP-activated protein kinase can negatively modulate Ornithine decarboxylase activity in cardiac myoblasts

AbstractThe responses of AMP-activated protein kinase (AMPK) and Ornithine decarboxylase (ODC) to isoproterenol have been examined in H9c2 cardiomyoblasts, AMPK represents the link between cell growth and energy availability whereas ODC, the key enzyme in polyamine biosynthesis, is essential for all growth processes and it is thought to have a role in the development of cardiac hypertrophy. Isoproterenol rapidly induced ODC activity in H9c2 cardiomyoblasts by promoting the synthesis of the enzyme protein and this effect was counteracted by inhibitors of the PI3K/Akt pathway. The increase in enzyme activity became significant between 15 and 30min after the treatment. At the same time, isoproterenol stimulated the phosphorylation of AMPKα catalytic subunits (Thr172), that was associated to an increase in acetyl coenzyme A carboxylase (Ser72) phosphorylation. Downregulation of both α1 and α2 isoforms of the AMPK catalytic subunit by siRNA to knockdown AMPK enzymatic activity, led to superinduction of ODC in isoproterenol-treated cardiomyoblasts. Downregulation of AMPKα increased ODC activity even in cells treated with other adrenergic agonists and in control cells. Analogue results were obtained in SH-SY5Y neuroblastoma cells transfected with a shRNA construct against AMPKα. In conclusion, isoproterenol quickly activates in H9c2 cardiomyoblasts two events that seem to contrast one another. The first one, an increase in ODC activity, is linked to cell growth, whereas the second, AMPK activation, is a homeostatic mechanism that negatively modulates the first. The modulation of ODC activity by AMPK represents a mechanism that may contribute to control cell growth processes

Caspase activation in etoposide‐treated fibroblasts is correlated to ERK phosphorylation and both events are blocked by polyamine depletion

Activation of the extracellular signal‐regulated kinases (ERKs) 1 and 2 is correlated to cell survival, but in some cases ERKs can act in signal transduction pathways leading to apoptosis. Treatment of mouse fibroblasts with 20 μM etoposide elicited a sustained phosphorylation of ERK 1/2, that increased until 24 h from the treatment in parallel with caspase activity. The inhibitor of ERK activation PD98059 abolished caspase activation, but caspase inhibition did not reduce ERK 1/2 phosphorylation, suggesting that ERK activation is placed upstream of caspases. Both ERK and caspase activation were blocked in cells depleted of polyamines by the ornithine decarboxylase inhibitor α‐difluoromethylornithine (DFMO). In etoposide‐treated cells, DFMO also abolished phosphorylation of c‐Jun NH2‐terminal kinases triggered by the drug. Polyamine replenishment with exogenous putrescine restored the ability of the cells to undergo caspase activation and ERK 1/2 phosphorylation in response to etoposide. Ornithine decarboxylase activity decreased after etoposide, indicating that DFMO exerts its effect by depleting cellular polyamines before induction of apoptosis. These results reveal a role for polyamines in the transduction of the death signal triggered by etoposide

Tunable supramolecular chirogenesis in the self-assembling of amphiphilic porphyrin triggered by chiral amines

Supramolecular chirality is one of the most important issues in different branches of science and technology, as stereoselective molecular recognition, catalysis, and sensors. In this paper, we report on the self-assembly of amphiphilic porphyrin derivatives possessing a chiral information on the periphery of the macrocycle (i.e., D- or L-proline moieties), in the presence of chiral amines as co-solute, such as chiral benzylamine derivatives. The aggregation process, steered by hydrophobic effect, has been studied in aqueous solvent mixtures by combined spectroscopic and topographic techniques. The results obtained pointed out a dramatic effect of these ligands on the morphology and on the supramolecular chirality of the final self-assembled structures. Scanning electron microscopy topography, as well as fluorescence microscopy studies revealed the formation of rod-like structures of micrometric size, different from the fractal structures formerly observed when the self-assembly process is carried out in the absence of chiral amine co-solutes. On the other hand, comparative experiments with an achiral porphyrin analogue strongly suggested that the presence of the prolinate moiety is mandatory for the achievement of the observed highly organized suprastructures. The results obtained would be of importance for unraveling the intimate mechanisms operating in the selection of the homochirality, and for the preparation of sensitive materials for the detection of chiral analytes, with tunable stereoselectivity and morphology