227 research outputs found

    Major practicum as a learning site for exercise science professionals: A pilot study

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    Exercise science is now an integral part of the allied health framework in Australia and graduates from accredited programmes are equipped with skills recognised as being important in the prevention and management of lifestyle-related diseases. This pilot study sought to determine the experiences of 11 final-year exercise science students in their major practicum and identify skills learned and developed while on placement. Analysis of the interview data established that the students worked with clients from a broad range of sociocultural and socioeconomic backgrounds, both within and between practicum sites; the students' experiences and their preparedness to engage with clients from different backgrounds varied as a result. Although the students generally reported being technically skilled for their major placement, many reported being underprepared to deal with people from different backgrounds. However, all participants held that their interpersonal skills greatly improved in response to their placement and several remarked that they developed their problem-solving skills through watching and assisting their supervisors work with clients. The present study confirms the practicum as a critical learning site for improving communication and problem-solving skills with exercise science and exercise physiology students

    Lead and δ-Aminolevulinic Acid Dehydratase Polymorphism: Where Does It Lead? A Meta-Analysis

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    BACKGROUND: Lead poisoning affects many organs in the body. Lead inhibits δ-aminolevulinic acid dehydratase (ALAD), an enzyme with two co-dominantly expressed alleles, ALAD1 and ALAD2. OBJECTIVE: Our meta-analysis studied the effects of the ALAD polymorphism on a) blood and bone lead levels and b) indicators of target organ toxicity. DATA SOURCE: We included studies reporting one or more of the following by individuals with genotypes ALAD1-1 and ALAD1-2/2-2: blood lead level (BLL), tibia or trabecular lead level, zinc protoporphyrin (ZPP), hemoglobin, serum creatinine, blood urea nitrogen (BUN), dimercaptosuccinic acid–chelatable lead, or blood pressure. DATA EXTRACTION: Sample sizes, means, and standard deviations were extracted for the genotype groups. DATA SYNTHESIS: There was a statistically significant association between ALAD2 carriers and higher BLL in lead-exposed workers (weighted mean differences of 1.93 μg/dL). There was no association with ALAD carrier status among environmentally exposed adults with BLLs < 10 μg/dL. ALAD2 carriers were potentially protected against adverse hemapoietic effects (ZPP and hemoglobin levels), perhaps because of decreased lead bioavailability to heme pathway enzymes. CONCLUSION: Carriers of the ALAD2 allele had higher BLLs than those who were ALAD1 homozygous and higher hemoglobin and lower ZPP, and the latter seems to be inversely related to BLL. Effects on other organs were not well delineated, partly because of the small number of subjects studied and potential modifications caused by other proteins in target tissues or by other polymorphic genes

    Sequencing the genome of the Burmese python (Python molurus bivittatus) as a model for studying extreme adaptations in snakes

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    The Consortium for Snake Genomics is in the process of sequencing the genome and creating transcriptomic resources for the Burmese python. Here, we describe how this will be done, what analyses this work will include, and provide a timeline

    TNF-α increases human melanoma cell invasion and migration in vitro: the role of proteolytic enzymes

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    Inflammatory mediators have been reported to promote malignant cell growth, invasion and metastatic potential. More specifically, we have recently reported that tumour necrosis factor alpha (TNF-a) increases melanoma cell attachment to extracellular matrix (ECM) substrates and invasion through fibronectin. In this study, we extend these investigations asking specifically whether the TNF-a effect on cell invasion and migration involves activation of proteolytic enzymes. We examined the effect of TNF-a on melanoma expression/activation of type IV gelatinases matrix metalloproteinases 2 and 9 (MMPs -2 and -9) and general proteolytic enzymes. Stimulation with TNF-a significantly increased both melanoma cell migration at 24 h ( þ 21%) and invasion through fibronectin ( þ 35%) but did not upregulate/activate the expression of latent MMP-2 constitutively produced by these cells and did not upregulate their general protease activity. However, the increased cell migration and invasion through fibronectin observed following stimulation with TNF-a were inhibited by the general protease inhibitor a2 macroglobulin. These findings suggest that the promigratory and proinvasive effect of TNF-a on this melanoma cell line may be mediated to some extent by induction of localised cell membrane-bound degradative enzyme activity, which is not readily detected in biochemical assays

    Toxic Metals (Pb and Cd) and Their Respective Antagonists (Ca and Zn) in Infant Formulas and Milk Marketed in Brasilia, Brazil

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    In non-ideal scenarios involving partial or non-breastfeeding, cow’s milk-based dairy products are mainstream in infant feeding. Therefore, it is important to study the concentrations of potentially neurotoxic contaminants (Pb and Cd) and their respective counteracting elements (Ca and Zn) in infant dairy products. Fifty-five brands of infant formulas and milk sold in Brasilia, Brazil were analyzed. The dairy products came from areas in the central-west (26%), southeast (29%) and south of Brazil (36%) extending as far as Argentina (7%) and the Netherlands (2%). For toxic Pb and Cd, median concentrations in powdered samples were 0.109 mg/kg and 0.033 mg/kg, respectively; in fluid samples median Pb concentration was 0.084 mg/kg, but median Cd concentration was below the limit of detection and overall values were below reference safety levels. However, 62% of these samples presented higher Pb concentration values than those established by FAO/WHO. Although the inverse correlation between Cd and Zn (Spearman r = −0.116; P = 0.590) was not statistically significant, the positive correlation between Ca and Pb was (Spearman r = 0.619; P < 0.0001). Additionally, there was a significant correlation between Pb and Cd. Furthermore, the study also revealed that provision of the essential trace element Zn in infant formulas can provide adequate amounts of the recommended daily requirements. Infant formulas and milk sold for consumption by infants and children can be an efficient tool to monitor neurotoxic metal risk exposure among young children

    Maternal Low-Level Lead Exposure and Fetal Growth

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    Background Limited epidemiologic studies have examined the association between maternal low-level lead exposure [blood lead (PbB) \u3c 10 μg/dL] and fetal growth. Objective We examined whether maternal low-level lead exposure is associated with decreased fetal growth. Methods We linked New York State Heavy Metals Registry records of women who had PbB measurements with birth certificates to identify 43,288 mother–infant pairs in upstate New York in a retrospective cohort study from 2003 through 2005. We used multiple linear regression with fractional polynomials and logistic regression to relate birth weight, preterm delivery, and small for gestational age to PbB levels, adjusting for potential confounders. We used a closed-test procedure to identify the best fractional polynomials for PbB among 44 combinations. Results We found a statistically significant association between PbB (square root transformed) and birth weight. Relative to 0 μg/dL, PbBs of 5 and 10 μg/dL were associated with an average of 61-g and 87-g decrease in birth weight, respectively. The adjusted odds ratio for PbBs between 3.1 and 9.9 μg/dL (highest quartile) was 1.04 [95% confidence interval (CI), 0.89–1.22] for preterm delivery and 1.07 (95% CI, 0.93–1.23) for small for gestational age, relative to PbBs ≤ 1 μg/dL (lowest quartile). No clear dose–response trends were evident when all of the quartiles were assessed. Conclusions Low-level PbB was associated with a small risk of decreased birth weight with a supralinear dose–response relationship, but was not related to preterm birth or small for gestational age. The results have important implications regarding maternal PbB

    Zinc/copper imbalance reflects immune dysfunction in human leishmaniasis: an ex vivo and in vitro study

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    BACKGROUND: The process of elimination of intracellular pathogens, such as Leishmania, requires a Th1 type immune response, whereas a dominant Th2 response leads to exacerbated disease. Experimental human zinc deficiency decreases Th1 but not Th2 immune response. We investigated if zinc and copper levels differ in different clinical forms of leishmaniasis, and if these trace metals might be involved in the immune response towards the parasite. METHODS: Blood was collected from 31 patients with either localized cutaneous (LCL), mucosal (ML) or visceral (VL) leishmaniasis, as well as from 25 controls from endemic and non-endemic areas. Anti-Leishmania humoral and cellular immune response were evaluated by quantifying specific plasma IgG, lymphoproliferation and cytokine production, respectively. Plasma levels of Cu and Zn were quantified by atomic absorption spectrophotometry. RESULTS: A significant decrease in plasma Zn was observed in all three patient groups (p < 0.01 for LCL and ML, p < 0.001 for VL), as compared to controls, but only VL (7/10) and ML (1/7) patients displayed overt Zn deficiency. Plasma Cu was increased in LCL and VL (p < 0.001) but not in ML, and was strongly correlated to anti-Leishmania IgG (Spearman r = 0.65, p = 0.0028). Cu/Zn ratios were highest in patients with deficient cellular (VL<<LCL<ML) and exacerbated humoral (VL>LCL>ML) immune response. Ex vivo production of parasite-induced IFN-γ was negatively correlated to plasma Cu levels in LCL (r = -0.57, p = 0.01). In vitro, increased Cu levels inhibited IFN-γ production. CONCLUSIONS: 1. Zn deficiency in VL and ML indicate possible therapeutic administration of Zn in these severe forms of leishmaniasis. 2. Plasma Cu positively correlates to humoral immune response across patient groups. 3. Environmentally or genetically determined increases in Cu levels might augment susceptibility to infection with intracellular pathogens, by causing a decrease in IFN-γ production
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