223 research outputs found
Protein supplementation in strength and conditioning adepts: knowledge, dietary behaviour and practice in Palermo, Italy
Background:
It is known that supplement use is a widespread and accepted practice by athletes and people who attend commercial gyms. Little is known about protein supplement amongst people undertaking strength training in commercial gyms in Italy when compared to the US.
Objective:
The purpose of this study was to examine the use of protein supplementation, alone or in association with other supplements, and dietary behavior amongst regular fitness center attendees in Palermo, Italy.
Design: Resistance training information have been collected from 800 regular fitness center attendees for the initial analysis. A specific questionnaire was generated for the experimentation. Data were collected using a face-to-face interview method. Supplement users were then compared to the non users and analyzed using a one-way ANOVA, Kruskall-Wallis, chi-square test or exact test of Fisher when appropriate.
Results:
30.1% of the respondents use dietary supplements during their training as a believe it is the "way to gain muscles and strength". Whey protein shakes (50.0%) mixed with creatine and amino-acids (48.3%) were the most frequent choices amongst the users. A majority of the subjects (34.0%) appeared to rely on their gym instructors' advice for their intake; a lower proportion (13.0%) consulted physicians, while none of them consulted nutritionists. A high consumption of milk has been noticed in both users (67,7%) and non-users (52,8%); supplement non-users consumed significantly more snacks and bakery products than users per week (P < 0.001), while users consumed significantly more protein-rich foods (P < 0.01) with a particular preference for meat (48.0%).
Conclusions:
A considerable number of regular strength training adepts consume protein supplements mixed with other products (mainly creatine and amino-acids). Limited numbers consult "dietary specialists" and rely mainly on their instructors. We emphasize on the importance of the dissemination of scientifically based information about supplementation in this environment and the promotion of updated educational programs for the instructors
Altered mRNA Editing and Expression of Ionotropic Glutamate Receptors after Kainic Acid Exposure in Cyclooxygenase-2 Deficient Mice
Kainic acid (KA) binds to the AMPA/KA receptors and induces seizures that result in inflammation, oxidative damage and neuronal death. We previously showed that cyclooxygenase-2 deficient (COX-2β/β) mice are more vulnerable to KA-induced excitotoxicity. Here, we investigated whether the increased susceptibility of COX-2β/β mice to KA is associated with altered mRNA expression and editing of glutamate receptors. The expression of AMPA GluR2, GluR3 and KA GluR6 was increased in vehicle-injected COX-2β/β mice compared to wild type (WT) mice in hippocampus and cortex, whereas gene expression of NMDA receptors was decreased. KA treatment decreased the expression of AMPA, KA and NMDA receptors in the hippocampus, with a significant effect in COX-2β/β mice. Furthermore, we analyzed RNA editing levels and found that the level of GluR3 R/G editing site was selectively increased in the hippocampus and decreased in the cortex in COX-2β/β compared with WT mice. After KA, GluR4 R/G editing site, flip form, was increased in the hippocampus of COX-2β/β mice. Treatment of WT mice with the COX-2 inhibitor celecoxib for two weeks decreased the expression of AMPA/KA and NMDAR subunits after KA, as observed in COX-2β/β mice. After KA exposure, COX-2β/β mice showed increased mRNA expression of markers of inflammation and oxidative stress, such as cytokines (TNF-Ξ±, IL-1Ξ² and IL-6), inducible nitric oxide synthase (iNOS), microglia (CD11b) and astrocyte (GFAP). Thus, COX-2 gene deletion can exacerbate the inflammatory response to KA. We suggest that COX-2 plays a role in attenuating glutamate excitotoxicity by modulating RNA editing of AMPA/KA and mRNA expression of all ionotropic glutamate receptor subunits and, in turn, neuronal excitability. These changes may contribute to the increased vulnerability of COX-2β/β mice to KA. The overstimulation of glutamate receptors as a consequence of COX-2 gene deletion suggests a functional coupling between COX-2 and the glutamatergic system
Mn bioavailability by polarized Caco-2 cells: comparison between Mn gluconate and Mn oxyprolinate
<p>Abstract</p> <p>Background</p> <p>Micronutrient inadequate intake is responsible of pathological deficiencies and there is a need of assessing the effectiveness of metal supplementation, frequently proposed to rebalance poor diets. Manganese (Mn) is present in many enzymatic intracellular systems crucial for the regulation of cell metabolism, and is contained in commercially available metal supplements.</p> <p>Methods</p> <p>We compared the effects of two different commercial Mn forms, gluconate (MnGluc) and oxyprolinate (MnOxP). For this purpose we used the polarized Caco-2 cells cultured on transwell filters, an established in vitro model of intestinal epithelium. Since micronutrient deficiency may accelerate mitochondrial efficiency, the mitochondrial response of these cells, in the presence of MnGluc and MnOxP, by microscopy methods and by ATP luminescence assay was used.</p> <p>Results</p> <p>In the presence of both MnOxP and MnGluc a sustained mitochondrial activity was shown by mitoTraker labeling (indicative of mitochondrial respiration), but ATP intracellular content remained comparable to untreated cells only in the presence of MnOxP. In addition MnOxP transiently up-regulated the antioxidant enzyme Mn superoxide dismutase more efficiently than MnGluc. Both metal treatments preserved NADH and Ξ²NADPH diaphorase oxidative activity, avoided mitochondrial dysfunction, as assessed by the absence of a sustained phosphoERK activation, and were able to maintain cell viability.</p> <p>Conclusions</p> <p>Collectively, our data indicate that MnOxP and MnGluc, and primarily the former, produce a moderate and safe modification of Caco-2 cell metabolism, by activating positive enzymatic mechanisms, thus could contribute to long-term maintenance of cell homeostasis.</p
Vav3 oncogene activates estrogen receptor and its overexpression may be involved in human breast cancer
<p>Abstract</p> <p>Background</p> <p>Our previous study revealed that Vav3 oncogene is overexpressed in human prostate cancer, activates androgen receptor, and stimulates growth in prostate cancer cells. The current study is to determine a potential role of Vav3 oncogene in human breast cancer and impact on estrogen receptor a (ERΞ±)-mediated signaling axis.</p> <p>Methods</p> <p>Immunohistochemistry analysis was performed in 43 breast cancer specimens and western blot analysis was used for human breast cancer cell lines to determine the expression level of Vav3 protein. The impact of Vav3 on breast cancer cell growth was determined by siRNA knockdown of Vav3 expression. The role of Vav3 in ERΞ± activation was examined in luciferase reporter assays. Deletion mutation analysis of Vav3 protein was performed to localize the functional domain involved in ERΞ± activation. Finally, the interaction of Vav3 and ERΞ± was assessed by GST pull-down analysis.</p> <p>Results</p> <p>We found that Vav3 was overexpressed in 81% of human breast cancer specimens, particularly in poorly differentiated lesions. Vav3 activated ERΞ± partially via PI3K-Akt signaling and stimulated growth of breast cancer cells. Vav3 also potentiated EGF activity for cell growth and ERΞ± activation in breast cancer cells. More interestingly, we found that Vav3 complexed with ERΞ±. Consistent with its function for AR, the DH domain of Vav3 was essential for ERΞ± activation.</p> <p>Conclusion</p> <p>Vav3 oncogene is overexpressed in human breast cancer. Vav3 complexes with ERΞ± and enhances ERΞ± activity. These findings suggest that Vav3 overexpression may aberrantly enhance ERΞ±-mediated signaling axis and play a role in breast cancer development and/or progression.</p
abd-A Regulation by the iab-8 Noncoding RNA
The homeotic genes in Drosophila melanogaster are aligned on the chromosome in the order of the body segments that they affect. The genes affecting the more posterior segments repress the more anterior genes. This posterior dominance rule must be qualified in the case of abdominal-A (abd-A) repression by Abdominal-B (Abd-B). Animals lacking Abd-B show ectopic expression of abd-A in the epidermis of the eighth abdominal segment, but not in the central nervous system. Repression in these neuronal cells is accomplished by a 92 kb noncoding RNA. This βiab-8 RNAβ produces a micro RNA to repress abd-A, but also has a second, redundant repression mechanism that acts only βin cis.β Transcriptional interference with the abd-A promoter is the most likely mechanism
Association of blood manganese level with diabetes and renal dysfunction: a cross-sectional study of the Korean general population
Herbal supplements in the print media: communicating benefits and risks
Background The rise in use of food supplements based on botanical ingredients (herbal supplements) is depicted as part of a trend empowering consumers to manage their day-to-day health needs, which presupposes access to clear and accurate information to make effective choices. Evidence regarding herbal supplement efficacy is extremely variable so recent regulations eliminating unsubstantiated claims about potential effects leave producers able to provide very little information about their products. Medical practitioners are rarely educated about herbal supplements and most users learn about them via word-of-mouth, allowing dangerous misconceptions to thrive, chief among them the assumption that natural products are inherently safe. Print media is prolific among the information channels still able to freely discuss herbal supplements. Method This study thematically analyses how 76 newspaper/magazine articles from the UK, Romania and Italy portray the potential risks and benefits of herbal supplements. Results Most articles referenced both risks and benefits and were factually accurate but often lacked context and impartiality. More telling was how the risks and benefits were framed in service of a chosen narrative, the paucity of authoritative information allowing journalists leeway to recontextualise herbal supplements in ways that serviced the goals and values of their specific publications and readerships. Conclusion Providing sufficient information to empower consumers should not be the responsibility of print media, instead an accessible source of objective information is required.</p
Dissection of Pol II Trigger Loop Function and Pol II ActivityβDependent Control of Start Site Selection In Vivo
Structural and biochemical studies have revealed the importance of a conserved, mobile domain of RNA Polymerase II (Pol II), the Trigger Loop (TL), in substrate selection and catalysis. The relative contributions of different residues within the TL to Pol II function and how Pol II activity defects correlate with gene expression alteration in vivo are unknown. Using Saccharomyces cerevisiae Pol II as a model, we uncover complex genetic relationships between mutated TL residues by combinatorial analysis of multiply substituted TL variants. We show that in vitro biochemical activity is highly predictive of in vivo transcription phenotypes, suggesting direct relationships between phenotypes and Pol II activity. Interestingly, while multiple TL residues function together to promote proper transcription, individual residues can be separated into distinct functional classes likely relevant to the TL mechanism. In vivo, Pol II activity defects disrupt regulation of the GTP-sensitive IMD2 gene, explaining sensitivities to GTP-production inhibitors, but contrasting with commonly cited models for this sensitivity in the literature. Our data provide support for an existing model whereby Pol II transcriptional activity provides a proxy for direct sensing of NTP levels in vivo leading to IMD2 activation. Finally, we connect Pol II activity to transcription start site selection in vivo, implicating the Pol II active site and transcription itself as a driver for start site scanning, contravening current models for this process
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