150 research outputs found

    CROSS-EDUCATION EFFECT OBSERVED IN VOLUIUTARY AND ELECTROMYOSTIMULATION STRENGTH TRAINING

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    This study investigated the effects of four weeks of unilateral electromyostimulation(EMS) versus isometric strength training(lM), on knee extension strength of contralateral limb in previously untrained young adults. Subjects performed (IM, n=10) or evoked (EMS, n=10) 40 isometric knee extensions, at an intensity of 65% of maximum voluntary contraction (MVC) force, three times per week, for four weeks. Pre and post training, both legs were tested for maximum voluntary strength on an isokinetic dynamometer, at 0 degls (isometric), 60 and 180 degls velocities. The results showed that the EMS and IM training had a similar effect in strength improvement in these subjects. Both types of training induced significant cross-education effect on isometric MVC of the untrained limb, but not in isokinetic torque. The mechanisms underlying this phenomenon require further study

    Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players

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    Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm) and larger brachial artery diameter during FMD (4.3 ± 0.5 mm versus 3.7 ± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 ± 6.4 mmHg versus 122.4 ± 6.8 mmHg), submaximal exercise (150.4 ± 18.8 mmHg versus 137.3 ± 9.5 mmHg), maximal exercise (211.3 ± 25.9 mmHg versus 191.4 ± 19.2 mmHg), and 24-hour BP (124.9 ± 6.3 mmHg versus 109.8 ± 3.7 mmHg). Football players also had higher fasting glucose (91.6 ± 6.5 mg/dL versus 86.6 ± 5.8 mg/dL), lower HDL (36.5±11.2 mg/dL versus 47.1±14.8 mg/dL), and higher body fat percentage (29.2±7.9% versus 23.2±7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk

    Endogenous cholinergic inputs and local circuit mechanisms govern the phasic mesolimbic dopamine response to nicotine

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    Nicotine exerts its reinforcing action by stimulating nicotinic acetylcholine receptors (nAChRs) and boosting dopamine (DA) output from the ventral tegmental area (VTA). Recent data have led to a debate about the principal pathway of nicotine action: direct stimulation of the DAergic cells through nAChR activation, or disinhibition mediated through desensitization of nAChRs on GABAergic interneurons. We use a computational model of the VTA circuitry and nAChR function to shed light on this issue. Our model illustrates that the α4β2-containing nAChRs either on DA or GABA cells can mediate the acute effects of nicotine. We account for in vitro as well as in vivo data, and predict the conditions necessary for either direct stimulation or disinhibition to be at the origin of DA activity increases. We propose key experiments to disentangle the contribution of both mechanisms. We show that the rate of endogenous acetylcholine input crucially determines the evoked DA response for both mechanisms. Together our results delineate the mechanisms by which the VTA mediates the acute rewarding properties of nicotine and suggest an acetylcholine dependence hypothesis for nicotine reinforcement.Peer reviewe

    Analyzing the regulation of metabolic pathways in human breast cancer

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    <p>Abstract</p> <p>Background</p> <p>Tumor therapy mainly attacks the metabolism to interfere the tumor's anabolism and signaling of proliferative second messengers. However, the metabolic demands of different cancers are very heterogeneous and depend on their origin of tissue, age, gender and other clinical parameters. We investigated tumor specific regulation in the metabolism of breast cancer.</p> <p>Methods</p> <p>For this, we mapped gene expression data from microarrays onto the corresponding enzymes and their metabolic reaction network. We used Haar Wavelet transforms on optimally arranged grid representations of metabolic pathways as a pattern recognition method to detect orchestrated regulation of neighboring enzymes in the network. Significant combined expression patterns were used to select metabolic pathways showing shifted regulation of the aggressive tumors.</p> <p>Results</p> <p>Besides up-regulation for energy production and nucleotide anabolism, we found an interesting cellular switch in the interplay of biosynthesis of steroids and bile acids. The biosynthesis of steroids was up-regulated for estrogen synthesis which is needed for proliferative signaling in breast cancer. In turn, the decomposition of steroid precursors was blocked by down-regulation of the bile acid pathway.</p> <p>Conclusion</p> <p>We applied an intelligent pattern recognition method for analyzing the regulation of metabolism and elucidated substantial regulation of human breast cancer at the interplay of cholesterol biosynthesis and bile acid metabolism pointing to specific breast cancer treatment.</p

    Correlation of microarray-based breast cancer molecular subtypes and clinical outcomes: implications for treatment optimization

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    <p>Abstract</p> <p>Background</p> <p>Optimizing treatment through microarray-based molecular subtyping is a promising method to address the problem of heterogeneity in breast cancer; however, current application is restricted to prediction of distant recurrence risk. This study investigated whether breast cancer molecular subtyping according to its global intrinsic biology could be used for treatment customization.</p> <p>Methods</p> <p>Gene expression profiling was conducted on fresh frozen breast cancer tissue collected from 327 patients in conjunction with thoroughly documented clinical data. A method of molecular subtyping based on 783 probe-sets was established and validated. Statistical analysis was performed to correlate molecular subtypes with survival outcome and adjuvant chemotherapy regimens. Heterogeneity of molecular subtypes within groups sharing the same distant recurrence risk predicted by genes of the Oncotype and MammaPrint predictors was studied.</p> <p>Results</p> <p>We identified six molecular subtypes of breast cancer demonstrating distinctive molecular and clinical characteristics. These six subtypes showed similarities and significant differences from the Perou-Sørlie intrinsic types. Subtype I breast cancer was in concordance with chemosensitive basal-like intrinsic type. Adjuvant chemotherapy of lower intensity with CMF yielded survival outcome similar to those of CAF in this subtype. Subtype IV breast cancer was positive for ER with a full-range expression of HER2, responding poorly to CMF; however, this subtype showed excellent survival when treated with CAF. Reduced expression of a gene associated with methotrexate sensitivity in subtype IV was the likely reason for poor response to methotrexate. All subtype V breast cancer was positive for ER and had excellent long-term survival with hormonal therapy alone following surgery and/or radiation therapy. Adjuvant chemotherapy did not provide any survival benefit in early stages of subtype V patients. Subtype V was consistent with a unique subset of luminal A intrinsic type. When molecular subtypes were correlated with recurrence risk predicted by genes of Oncotype and MammaPrint predictors, a significant degree of heterogeneity within the same risk group was noted. This heterogeneity was distributed over several subtypes, suggesting that patients in the same risk groups require different treatment approaches.</p> <p>Conclusions</p> <p>Our results indicate that the molecular subtypes established in this study can be utilized for customization of breast cancer treatment.</p

    Mesopontine rostromedial tegmental nucleus neurons projecting to the dorsal raphe and pedunculopontine tegmental nucleus: psychostimulant-elicited Fos expression and collateralization

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    The mesopontine rostromedial tegmental nucleus (RMTg) is a GABAergic structure in the ventral midbrain and rostral pons that, when activated, inhibits dopaminergic neurons in the ventral tegmental area and substantia nigra compacta. Additional strong outputs from the RMTg to the pedunculopontine tegmental nucleus pars dissipata, dorsal raphe nucleus, and the pontomedullary gigantocellular reticular formation were identified by anterograde tracing. RMTg neurons projecting to the ventral tegmental area express the immediate early gene Fos upon psychostimulant administration. The present study was undertaken to determine if neurons in the RMTg that project to the additional structures listed above also express Fos upon psychostimulant administration and, if so, whether single neurons in the RMTg project to more than one of these structures. We found that about 50% of RMTg neurons exhibiting retrograde labeling after injections of retrograde tracer in the dorsal raphe or pars dissipata of the pedunculopontine tegmental nucleus express Fos after acute methamphetamine exposure. Also, we observed that a significant number of RMTg neurons project both to the ventral tegmental area and one of these structures. In contrast, methamphetamine-elicited Fos expression was not observed in RMTg neurons labeled with retrograde tracer following injections into the pontomedullary reticular formation. The findings suggest that the RMTg is an integrative modulator of multiple rostrally projecting structures

    Agency, stewardship and the universal-family firm : a qualitative historical analysis

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    This paper introduces the idea of a non-kinship-based Universal-family firm, an organizational form we developed based on interpreting historical writings in their socio-economic context. We analyzed Luke’s gospel with an eye toward drawing implications for the stewardship-agency debate in the contemporary family business literature. Our paper makes contributions at two important levels. In addition to introducing and developing theory about the Universal-family firms, we also contribute to the methodological toolkit of family business scholars by providing a template for using historical documents to challenge, enhance and develop theory

    Multidisciplinary approach of early breast cancer: The biology applied to radiation oncology

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    Early breast cancer treatment is based on a multimodality approach with the application of clinical and histological prognostic factors to determine locoregional and systemic treatments. The entire scientific community is strongly involved in the management of this disease: radiologists for screening and early diagnosis, gynecologists, surgical oncologists and radiation oncologists for locoregional treatment, pathologists and biologists for personalized characterization, genetic counselors for BRCA mutation history and medical oncologists for systemic therapies

    Transcriptomic landscape of breast cancers through mRNA sequencing

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    Breast cancer is a heterogeneous disease with a poorly defined genetic landscape, which poses a major challenge in diagnosis and treatment. By massively parallel mRNA sequencing, we obtained 1.2 billion reads from 17 individual human tissues belonging to TNBC, Non-TNBC, and HER2-positive breast cancers and defined their comprehensive digital transcriptome for the first time. Surprisingly, we identified a high number of novel and unannotated transcripts, revealing the global breast cancer transcriptomic adaptations. Comparative transcriptomic analyses elucidated differentially expressed transcripts between the three breast cancer groups, identifying several new modulators of breast cancer. Our study also identified common transcriptional regulatory elements, such as highly abundant primary transcripts, including osteonectin, RACK1, calnexin, calreticulin, FTL, and B2M, and “genomic hotspots” enriched in primary transcripts between the three groups. Thus, our study opens previously unexplored niches that could enable a better understanding of the disease and the development of potential intervention strategies
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