76 research outputs found

    Accuracy and Reliability of Examiners’ Observations of Pre-Practice Warm-Up and FIFA 11+ Injury Prevention Program Exercises

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    Background: The Fédération Internationale de Football Association (FIFA) 11+ is an injury prevention program that decreases the incidence of lower extremity injuries. The purpose of the current study was to understand what specific exercises prevented injury from occurring. We thus developed and tested a form to identify these exercises. We hypothesize that trained examiners could accurately and reliably use this form to identify and record individual exercises performed during preparticipation warm-up. Methods: A repeated-measures study design was used in this investigation. After observing five prepractice warm-up videos obtained from multiple high schools, 11 examiners observed and recorded performed exercises at two different times. The videos included four soccer teams and one American football team. Accuracy, interexaminer reliability, and intraexaminer reliability were assessed. Sensitivity, specificity, accuracy, and percent agreement with a FIFA 11+ expert were measured for each exercise component. Results: The intraclass correlation coefficients between examiners and individually ranged from 0.22 to 1.00 and 0.58 to 1.00, respectively. Reliability was lowest for exercises with similar movements. The percent agreement across all examiners for individual exercises ranged from 20% to 100%. Additionally, the percent agreement between each examiner and the “gold standard” examiner was high (range, 69.6% to 90.4%). For exercises with similar movements, accuracy and reliability were considerably improved (97%) when combined into one category. Conclusion: We determined that trained examiners with different backgrounds and experience can make accurate and reliable observations of most exercises observed in warm-up programs. Using the proposed form, researchers can accurately record exercises and perform quality and fidelity assessments of warm-up exercise routines

    Blocking of ERK1 and ERK2 sensitizes human mesothelioma cells to doxorubicin

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    <p>Abstract</p> <p>Background</p> <p>Malignant mesotheliomas (MM) have a poor prognosis, largely because of their chemoresistance to anti-cancer drugs such as doxorubicin (Dox). Here we show using human MM lines that Dox activates extracellular signal-regulated kinases (ERK1 and 2), causally linked to increased expression of ABC transporter genes, decreased accumulation of Dox, and enhanced MM growth. Using the MEK1/2 inhibitor, U0126 and stably transfected shERK1 and shERK2 MM cell lines, we show that inhibition of both ERK1 and 2 sensitizes MM cells to Dox.</p> <p>Results</p> <p>U0126 significantly modulated endogenous expression of several important drug resistance (<it>BCL2, ABCB1, ABCC3</it>), prosurvival (<it>BCL2</it>), DNA repair (<it>BRCA1, BRCA2</it>), hormone receptor (<it>AR, ESR2, PPARγ</it>) and drug metabolism (<it>CYP3A4</it>) genes newly identified in MM cells. In comparison to shControl lines, MM cell lines stably transfected with shERK1 or shERK2 exhibited significant increases in intracellular accumulation of Dox and decreases in cell viability. Affymetrix microarray analysis on stable shERK1 and shERK2 MM lines showed more than 2-fold inhibition (p ≤ 0.05) of expression of ATP binding cassette genes (<it>ABCG1, ABCA5, ABCA2, MDR/TAP, ABCA1, ABCA8, ABCC2</it>) in comparison to shControl lines. Moreover, injection of human MM lines into SCID mice showed that stable shERK1 or shERK2 lines had significantly slower tumor growth rates in comparison to shControl lines after Dox treatment.</p> <p>Conclusions</p> <p>These studies suggest that blocking ERK1 and 2, which play critical roles in multi-drug resistance and survival, may be beneficial in combination with chemotherapeutic drugs in the treatment of MMs and other tumors.</p

    CREB-Induced Inflammation Is Important for Malignant Mesothelioma Growth

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    Malignant mesothelioma (MM) is an aggressive tumor with no treatment regimen. Previously we have demonstrated that cyclic AMP response element binding protein (CREB) is constitutively activated in MM tumor cells and tissues and plays an important role in MM pathogenesis. To understand the role of CREB in MM tumor growth, we generated CREB-inhibited MM cell lines and performed in vitro and in vivo experiments. In vitro experiments demonstrated that CREB inhibition results in significant attenuation of proliferation and drug resistance of MM cells. CREB-silenced MM cells were then injected into severe combined immunodeficiency mice, and tumor growth in s.c. and i.p. models of MM was followed. We observed significant inhibition in MM tumor growth in both s.c. and i.p. models and the presence of a chemotherapeutic drug, doxorubicin, further inhibited MM tumor growth in the i.p. model. Peritoneal lavage fluids from CREB-inhibited tumor-bearing mice showed a significantly reduced total cell number, differential cell counts, and pro-inflammatory cytokines and chemokines (IL-6, IL-8, regulated on activation normal T cell expressed and secreted, monocyte chemotactic protein-1, and vascular endothelial growth factor). In vitro studies showed that asbestos-induced inflammasome/inflammation activation in mesothelial cells was CREB dependent, further supporting the role of CREB in inflammation-induced MM pathogenesis. In conclusion, our data demonstrate the involvement of CREB in the regulation of MM pathogenesis by regulation of inflammation

    Mechanisms of oxidative stress and alterations in gene expression by Libby six-mix in human mesothelial cells

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    <p>Abstract</p> <p>Background</p> <p>Exposures to an amphibole fiber in Libby, Montana cause increases in malignant mesothelioma (MM), a tumor of the pleural and peritoneal cavities with a poor prognosis. Affymetrix microarray/GeneSifter analysis was used to determine alterations in gene expression of a human mesothelial cell line (LP9/TERT-1) by a non-toxic concentration (15×10<sup>6 </sup>μm<sup>2</sup>/cm<sup>2</sup>) of unprocessed Libby six-mix and negative (glass beads) and positive (crocidolite asbestos) controls. Because manganese superoxide dismutase (MnSOD; SOD2) was the only gene upregulated significantly (p < 0.05) at both 8 and 24 h, we measured SOD protein and activity, oxidative stress and glutathione (GSH) levels to better understand oxidative events after exposure to non-toxic (15×10<sup>6 </sup>μm<sup>2</sup>/cm<sup>2</sup>) and toxic concentrations (75×10<sup>6 </sup>μm<sup>2</sup>/cm<sup>2</sup>) of Libby six-mix.</p> <p>Results</p> <p>Exposure to 15×10<sup>6 </sup>μm<sup>2</sup>/cm<sup>2 </sup>Libby six-mix elicited significant (p < 0.05) upregulation of one gene (<it>SOD2</it>; 4-fold) at 8 h and 111 gene changes at 24 h, including a 5-fold increase in <it>SOD2</it>. Increased levels of SOD2 mRNA at 24 h were also confirmed in HKNM-2 normal human pleural mesothelial cells by qRT-PCR. SOD2 protein levels were increased at toxic concentrations (75×10<sup>6 </sup>μm<sup>2</sup>/cm<sup>2</sup>) of Libby six-mix at 24 h. In addition, levels of copper-zinc superoxide dismutase (Cu/ZnSOD; SOD1) protein were increased at 24 h in all mineral groups. A dose-related increase in SOD2 activity was observed, although total SOD activity remained unchanged. Dichlorodihydrofluorescein diacetate (DCFDA) fluorescence staining and flow cytometry revealed a dose- and time-dependent increase in reactive oxygen species (ROS) production by LP9/TERT-1 cells exposed to Libby six-mix. Both Libby six-mix and crocidolite asbestos at 75×10<sup>6 </sup>μm<sup>2</sup>/cm<sup>2 </sup>caused transient decreases (p < 0.05) in GSH for up to 24 h and increases in gene expression of heme oxygenase 1 (<it>HO-1</it>) in LP9/TERT-1 and HKNM-2 cells.</p> <p>Conclusions</p> <p>Libby six-mix causes multiple gene expression changes in LP9/TERT-1 human mesothelial cells, as well as increases in SOD2, increased production of oxidants, and transient decreases in intracellular GSH. These events are not observed at equal surface area concentrations of nontoxic glass beads. Results support a mechanistic basis for the importance of SOD2 in proliferation and apoptosis of mesothelial cells and its potential use as a biomarker of early responses to mesotheliomagenic minerals.</p

    1,3-Butadiene: Biomarkers and application to risk assessment

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    1,3-Butadiene (BD) is a known rodent and human carcinogen that is metabolized mainly by P450 2E1 to three epoxides, 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB) and 1,2-epoxy-3,4-butanediol (EB-diol). The individual epoxides vary up to 200-fold in their mutagenic potency, with DEB being the most mutagenic metabolite. It is important to understand the internal formation of the individual epoxides to assign the relative risk for each metabolite and to understand the molecular mechanisms responsible for major species differences in carcinogenicity. We have conducted extensive exposure-biomarker studies on mice, rats and humans. Using low exposures that range from current occupational levels to human exposures from tobacco smoke has provided evidence that mice are very different from humans, with mice forming ~200 times more DEB than humans at exposures of 0.1–1.5 ppm BD. While no gender differences have been noted in mice and rats for globin adducts or N-7 guanine adducts, female rats and mice had 2–3-fold higher Hprt mutations and DNA-DNA cross-links, suggesting a gender difference in DNA repair. Numerous molecular epidemiology studies have evaluated globin adducts and Hprt mutations, SCEs and chromosomal abnormalities. None of the blinded studies have shown evidence of human genotoxicity at current occupational exposures and studies of globin adducts have shown similar or lower formation of adducts in females than males. If one calculates the EB dose-equivalents for the three species, mice clearly differ from rats and humans, being ~44 and 174 times greater than rats and humans, respectively. These data provide a scientific basis for improved risk assessment of BD

    Ages at menarche- and menopause-related genetic variants in relation to terminal duct lobular unit involution in normal breast tissue

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    PURPOSE: Reduced levels of terminal duct lobular unit (TDLU) involution, as reflected by higher numbers of TDLUs and acini per TDLU, have been associated with higher breast cancer risk. Younger age at menarche and older age at menopause have been previously related to lower levels of TDLU involution. To determine a possible genetic link, we examined whether single nucleotide polymorphisms (SNPs) previously established in genome-wide association studies (GWAS) for ages at menarche and menopause are associated with TDLU involution. METHODS: We conducted a pooled analysis of 862 women from two studies. H&E tissue sections were assessed for numbers of TDLUs and acini/TDLU. Poisson regression models were used to estimate associations of 36 menarche- and 21 menopause-SNPs with TDLU counts, acini counts/TDLU, and the product of these two measures, adjusting for age and study site. RESULTS: Fourteen percent of evaluated SNPs (8 SNPs) were associated with TDLU counts at p<0.05, suggesting an enrichment of associations with TDLU counts. However, only menopause-SNPs had >50% that were either significantly or nonsignficantly associated with TDLU measures in the directions consistent with their relationships shown in GWAS. Among 10 SNPs that were statistically significantly associated with at least one TDLU involution measure (p<0.05), seven SNPs (rs466639: RXRG; rs2243803: SLC14A2; rs2292573: GAB2; rs6438424: 3q13.32; rs7606918: METAP1D; rs11668344: TMEM150B; rs1635501: EXO1) were associated in the consistent directions. CONCLUSIONS: Our data suggest that the loci associated with ages at menarche and menopause may influence TDLU involution, suggesting some shared genetic mechanisms. However, larger studies are needed to confirm the results
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