911 resultados para anaerobic capacity and creatine kinase
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Duchenne muscular dystrophy is an X-linked genetic disease caused by the absence of functional dystrophin. Pharmacological upregulation of utrophin, the autosomal homologue of dystrophin, offers a potential therapeutic approach to treat Duchenne patients. Full-length utrophin mRNA is transcribed from two alternative promoters, called A and B. In contrast to the utrophin promoter A, little is known about the factors regulating the activity of the utrophin promoter B. Computer analysis of this second promoter revealed the presence of several conserved binding motives for Ets-transcription factors. Using electrotransfer of cDNA into mouse muscles, we demonstrate that a genetically modified beta-subunit of the Ets-transcription factor GA-binding protein potently activates a utrophin promoter B reporter construct in innervated muscle fibers in vivo. These results make the GA-binding protein and the signaling cascade regulating its activity in muscle cells, potential targets for the pharmacological modulation of utrophin expression in Duchenne patients.
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We investigated the physiological consequences of the most challenging mountain ultra-marathon (MUM) in the world: a 330-km trail run with 24000 m of positive and negative elevation change. Neuromuscular fatigue (NMF) was assessed before (Pre-), during (Mid-) and after (Post-) the MUM in experienced ultra-marathon runners (n = 15; finish time = 122.43 hours ±17.21 hours) and in Pre- and Post- in a control group with a similar level of sleep deprivation (n = 8). Blood markers of muscle inflammation and damage were analyzed at Pre- and Post-. Mean ± SD maximal voluntary contraction force declined significantly at Mid- (-13±17% and -10±16%, P<0.05 for knee extensor, KE, and plantar flexor muscles, PF, respectively), and further decreased at Post- (-24±13% and -26±19%, P<0.01) with alteration of the central activation ratio (-24±24% and -28±34% between Pre- and Post-, P<0.05) in runners whereas these parameters did not change in the control group. Peripheral NMF markers such as 100 Hz doublet (KE: -18±18% and PF: -20±15%, P<0.01) and peak twitch (KE: -33±12%, P<0.001 and PF: -19±14%, P<0.01) were also altered in runners but not in controls. Post-MUM blood concentrations of creatine kinase (3719±3045 Ul·(1)), lactate dehydrogenase (1145±511 UI·L(-1)), C-Reactive Protein (13.1±7.5 mg·L(-1)) and myoglobin (449.3±338.2 µg·L(-1)) were higher (P<0.001) than at Pre- in runners but not in controls. Our findings revealed less neuromuscular fatigue, muscle damage and inflammation than in shorter MUMs. In conclusion, paradoxically, such extreme exercise seems to induce a relative muscle preservation process due likely to a protective anticipatory pacing strategy during the first half of MUM and sleep deprivation in the second half.
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Exogenous administration of glucocorticoids is a widely used and efficient tool to investigate the effects of elevated concentrations of these hormones in field studies. Because the effects of corticosterone are dose and duration-dependent, the exact course of plasma corticosterone levels after exogenous administration needs to be known. We tested the performance of self-degradable corticosterone pellets (implanted under the skin) in elevating plasma corticosterone levels. We monitored baseline (sampled within 3min after capture) total corticosterone levels and investigated potential interactions with corticosteroid-binding-globulin (CBG) capacity and the endogenous corticosterone response to handling in Eurasian kestrel Falco tinnunculus and barn owl Tyto alba nestlings. Corticosterone pellets designed for a 7-day-release in rodents elevated circulating baseline total corticosterone during only 2-3 days compared to placebo-nestlings. Highest levels occurred 1-2days after implantation and levels decreased strongly thereafter. CBG capacity was also increased, resulting in a smaller, but still significant, increase in baseline free corticosterone levels. The release of endogenous corticosterone as a response to handling was strong in placebo-nestlings, but absent 2 and 8 days after corticosterone pellet implantation. This indicates a potential shut-down of the hypothalamo-pituitary-adrenal axis after the 2-3 days of elevated baseline corticosterone levels. 20 days after pellet implantation, the endogenous corticosterone response to handling of nestlings implanted with corticosterone pellets attained similar levels as in placebo-nestlings. Self-degradable pellets proved to be an efficient tool to artificially elevate circulating baseline corticosterone especially in field studies, requiring only one intervention. The resulting peak-like elevation of circulating corticosterone, the concomitant elevation of CBG capacity, and the absence of an endogenous corticosterone response to an acute stressor have to be taken into account.
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Evidence has emerged that the initiation and growth of gliomas is sustained by a subpopulation of cancer-initiating cells (CICs). Because of the difficulty of using markers to tag CICs in gliomas, we have previously exploited more robust phenotypic characteristics, including a specific morphology and intrincic autofluorescence, to identify and isolate a subpopulation of glioma CICs, called FL1(+). The objective of this study was to further validate our method in a large cohort of human glioma and a mouse model of glioma. Seventy-four human gliomas of all grades and the GFAP-V(12)HA-ras B8 mouse model were analyzed for in vitro self-renewal capacity and their content of FL1(+). Nonneoplastic brain tissue and embryonic mouse brain were used as control. Genetic traceability along passages was assessed with microsatellite analysis. We found that FL1(+) cells from low-grade gliomas and from control nonneoplasic brain tissue show a lower level of autofluorescence and undergo a restricted number of cell divisions before dying in culture. In contrast, we found that FL1(+) cells derived from many but not all high-grade gliomas acquire high levels of autofluorescence and can be propagated in long-term cultures. Moreover, FL1(+) cells show a remarkable traceability over time in vitro and in vivo. Our results show that FL1(+) cells can be found in all specimens of a large cohort of human gliomas of different grades and in a model of genetically induced mouse glioma as well as nonneoplastic brain. However, their self-renewal capacity is variable and seems to be dependent on the tumor grade.
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PURPOSE OF REVIEW: The control of glucose and energy homeostasis, including feeding behaviour, is tightly regulated by gut-derived peptidic and nonpeptidic endocrine mediators, autonomic nervous signals, as well as nutrients such as glucose. We will review recent findings on the role of the gastrointestinal tract innervation and of portal vein glucose sensors; we will review selected data on the action of gastrointestinally released hormones. RECENT FINDINGS: The involvement of mechanosensory vagal afferents in postprandial meal termination has been clarified using mouse models with selective impairments of genes required for development of mechanosensory fibres. These activate central glucogen-like peptide-1/glucogen-like peptide-2 containing ascending pathways linking the visceroceptive brainstem neurons to hypothalamic nuclei. Mucosal terminals comprise the chemosensory vagal afferents responsive to postprandially released gastrointestinal hormones. The mechanism by which the hepatoportal glucose sensor stimulates glucose utilization by muscles was demonstrated, using genetically modified mice, to be insulin-independent but to require GLUT4 and AMP-kinase. This sensor is a key site of glucogen-like peptide-1 action and plays a critical role in triggering first phase insulin secretion. PeptideYY and ghrelin target intracerebral receptors as they are bidirectionally transported across the blood brain barrier. The anorectic functions of peripherally released peptideYY may however be mediated both via vagal afferents and intracerebral Y2 receptors in the brainstem and arcuate nucleus. SUMMARY: These recent findings demonstrate that the use of improved anatomical and physiological techniques and animal models with targeted gene modifications lead to an improved understanding of the complex role of gastrointestinal signals in the control of energy homeostasis.
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The Programme for Prosperity and Fairness outlined the commitment of the Government to a review of hospital bed capacity in both acute and non-acute settings, to be carried out by the Department of Health and Children in conjunction with the Department of Finance and in consultation with the Social Partners. The focus of this report is on bed capacity in publicly-funded acute hospitals in Ireland. The capacity needs of the sub-acute sector have been assessed separately in the context of the Health Strategy, Quality and Fairness: A Health System for You. Download document here
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To gain insight into the function and regulation of malonyl-CoA decarboxylase (MCD) we have cloned rat MCD cDNA from a differentiated insulin-secreting pancreatic beta-cell-line cDNA library. The full-length cDNA sequence shows 69% identity with the cDNA cloned previously from the goose uropygial gland, and predicts a 492 amino acid protein of 54.7 kDa. The open reading frame contains an N-terminal mitochondrial targeting sequence and the C-terminal part of the enzyme ends with a peroxisomal (Ser-Lys-Leu) targeting motif. Since the sequence does not reveal hydrophobic domains, MCD is most likely expressed in the mitochondrial matrix and inside the peroxisomes. A second methionine residue, located 3' of the mitochondrial presequence, might be the first amino acid of a putative cytosolic MCD, since the nucleotide sequence around it fits fairly well with a consensus Kozak site for translation initiation. However, primer extension detects the presence of only one transcript initiating upstream of the first ATG, indicating that the major, if not exclusive, transcript expressed in the pancreatic beta-cell encodes MCD with its mitochondrial presequence. The sequence also shows multiple possible sites of phosphorylation by casein kinase II and protein kinase C. mRNA tissue-distribution analysis indicates a transcript of 2.2 kb, and that the MCD gene is expressed over a wide range of rat tissues. The distribution of the enzyme shows a broad range of activities from very low in the brain to elevated in the liver and heart. The results provide the foundations for further studies of the role of MCD in lipid metabolism and metabolic signalling in various tissues.
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Primary cultures of cardiomyocytes represent a useful model for analyzing cardiac cell biology as well as pathogenesis of several cardiovascular disorders. Our aim was to standardize protocols for determining the damage of cardiac cells cultured in vitro by measuring the creatine kinase and its cardiac isotype and lactate dehydrogenase activities in the supernatants of mice cardiomyocytes submitted to different protocols of cell lysis. Our data showed that due to its higher specificity, the cardiac isotype creatine kinase was the most sensitive as compared to the others studied enzymatic markers, and can be used to monitor and evaluate cardiac damage in in vitro assays.
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The neurochemical profile of the cortex develops in a region and time specific manner, which can be distorted by psychiatric and other neurological pathologies. Pre-clinical studies often involve experimental mouse models. In this study, we determined the neurochemical profile of C57BL/6 mice in a longitudinal study design to provide a reference frame for the normal developing mouse cortex. Using in vivo proton NMR spectroscopy at 14 T, we measured the concentrations of 18 metabolites in the anterior and posterior cortex on postnatal days (P) 10, 20, 30, 60 and 90. Cortical development was marked by alterations of highly concentrated metabolites, such as N-acetylaspartate, glutamate, taurine and creatine. Regional specificity was represented by early variations in the concentration of glutamine, aspartate and choline. In adult animals, regional concentration differences were found for N-acetylaspartate, creatine and myo-inositol. In this study, animals were exposed to recurrent isoflurane anaesthesia. Additional experiments showed that the latter was devoid of major effects on behaviour or cortical neurochemical profile. In conclusion, the high sensitivity and reproducibility of the measurements achieved at 14 T allowed us to identify developmental variations of cortical areas within the mouse cortex.
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INTRODUCTION: Smoothelin is a cytoskeletal protein of differentiated smooth muscle cells with contractile capacity, distinguishing it from other smooth muscle proteins, such as smooth muscle actin (SMA). OBJECTIVE: To evaluate the expression of smoothelin and SMA in the skin in order to establish specific localizations of smoothelin in smooth muscle cells with high contractile capacity and in the epithelial component of cutaneous adnexal structures. Methods: Immunohistochemical analysis (smoothelin and SMA) was performed in 18 patients with normal skin. RESULTS: SMA was expressed by the vascular structures of superficial, deep, intermediate and adventitial plexuses, whereas smoothelin was specifically expressed in the cytoplasm of smooth muscle cells of the deepest vascular plexus and in no other plexus of the dermis. The hair erector muscle showed intense expression of smoothelin and SMA. Cells with nuclear expression of smoothelin and cytoplasmic expression of SMA were observed in the outer root sheath of the inferior portion of the hair follicles and intense cytoplasmic expression in cells of the dermal sheath to SMA. CONCLUSIONS: We report the first study of smoothelin expression in normal skin, which differentiates the superficial vascular plexus from the deep. The deep plexus comprises vessels with high contractile capacity, which is important for understanding dermal hemodynamics in normal skin and pathological processes. We suggest that the function of smoothelin in the outer root sheath may be to enhance the function of SMA, which has been related to mechanical stress. Smoothelin has not been studied in cutaneous pathology; however we believe it may be a marker specific for the diagnosis of leiomyomas and leiomyosarcomas of the skin. Also, smoothelin could differentiate arteriovenous malformations of cavernous hemangioma of the skin
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Obesity-induced chronic inflammation leads to activation of the immune system that causes alterations of iron homeostasis including hypoferraemia, iron-restricted erythropoiesis, and finally mild-to-moderate anaemia. Thus, preoperative anaemia and iron deficiency are common among obese patients scheduled for bariatric surgery (BS). Assessment of patients should include a complete haematological and biochemical laboratory work-up, including measurement of iron stores, vitamin B12 and folate. In addition, gastrointestinal evaluation is recommended for most patients with iron-deficiency anaemia. On the other hand, BS is a long-lasting inflammatory stimulus in itself and entails a reduction of the gastric capacity and/or exclusion from the gastrointestinal tract which impair nutrients absorption, including dietary iron. Chronic gastrointestinal blood loss and iron-losingenteropathy may also contribute to iron deficiency after BS. Perioperative anaemia has been linked to increased postoperative morbidity and mortality and decreased quality of life after major surgery, whereas treatment of perioperative anaemia, and even haematinic deficiency without anaemia, has been shown to improve patient outcomes and quality of life. However, long-term follow-up data in regard to prevalence, severity, and causes of anaemia after BS are mostly absent. Iron supplements should be administered to patients after BS, but compliance with oral iron is no good. In addition, once iron deficiency has developed, it may prove refractory to oral treatment. In these situations, IV iron (which can circumvent the iron blockade at enterocytes and macrophages) has emerged as a safe and effective alternative for perioperative anaemia management. Monitoring should continue indefinitely even after the initial iron repletion and anaemia resolution, and maintenance IV iron treatment should be provided as required. New IV preparations, such ferric carboxymaltose, are safe, easy to use and up to 1000 mg can be given in a single session, thus providing an excellent tool to avoid or treat iron deficiency in this patient population.
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Because of the emergence of dried blood spots (DBS) as an attractive alternative to conventional venous plasma sampling in many pharmaceutical companies and clinical laboratories, different analytical approaches have been developed to enable automated handling of DBS samples without any pretreatment. Associated with selective and sensitive MS-MS detection, these procedures give good results in the rapid identification and quantification of drugs (generally less than 3 min total run time), which is desirable because of the high throughput requirements of analytical laboratories. The objective of this review is to describe the analytical concepts of current direct DBS techniques and to present their advantages and disadvantages, with particular focus on automation capacity and commercial availability. Finally, an overview of the different biomedical applications in which these concepts could be of major interest will be presented.
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Els isòtops estables com a traçadors de la cadena alimentària, s'han utilitzat per caracteritzar la relació entre els consumidors i els seus aliments, ja que el fraccionament isotòpic implica una discriminació en contra de certs isòtops. Però les anàlisis d'isòtops estables (SIA), també es poden dur a terme en peixos cultivats amb dietes artificials, com la orada (Sparus aurata), la especie más cultivada en el Mediterráneo. Canvis en l'abundància natural d'isòtops estables (13C i 15N) en els teixits i les seves reserves poden reflectir els canvis en l'ús i reciclatge dels nutrients ja que els enzims catabòlics implicats en els processos de descarboxilació i desaminació mostren una preferència pels isòtops més lleugers. Per tant, aquestes anàlisis ens poden proporcionar informació útil sobre l'estat nutricional i metabòlic dels peixos. L'objectiu d'aquest projecte va ser determinar la capacitat dels isòtops estables per ser utilitzats com a marcadors potencials de la capacitat de creixement i condicions de cria de l'orada. En aquest sentit, les anàlisis d'isòtops estables s'han combinat amb altres metabòlics (activitats citocrom-c-oxidasa, COX, i citrat sintasa, CS) i els paràmetres de creixement (ARN/ADN). El conjunt de resultats obtinguts en els diferents estudis realitzats en aquest projecte demostra que el SIA, en combinació amb altres paràmetres metabòlics, pot servir com una eina eficaç per discriminar els peixos amb millor potencial de creixement, així com a marcador sensible de l'estat nutricional i d'engreix. D'altra banda, la combinació de l'anàlisi d'isòtops estables amb les eines emergents, com ara tècniques de proteòmica (2D-PAGE), ens proporciona nous coneixements sobre els canvis metabòlics que ocorren en els músculs dels peixos durant l‟increment del creixement muscular induït per l'exercici.
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BACKGROUND Breast cancer survivors suffer physical impairment after oncology treatment. This impairment reduces quality of life (QoL) and increase the prevalence of handicaps associated to unhealthy lifestyle (for example, decreased aerobic capacity and strength, weight gain, and fatigue). Recent work has shown that exercise adapted to individual characteristics of patients is related to improved overall and disease-free survival. Nowadays, technological support using telerehabilitation systems is a promising strategy with great advantage of a quick and efficient contact with the health professional. It is not known the role of telerehabilitation through therapeutic exercise as a support tool to implement an active lifestyle which has been shown as an effective resource to improve fitness and reduce musculoskeletal disorders of these women. METHODS / DESIGN This study will use a two-arm, assessor blinded, parallel randomized controlled trial design. People will be eligible if: their diagnosis is of stages I, II, or IIIA breast cancer; they are without chronic disease or orthopedic issues that would interfere with ability to participate in a physical activity program; they had access to the Internet and basic knowledge of computer use or living with a relative who has this knowledge; they had completed adjuvant therapy except for hormone therapy and not have a history of cancer recurrence; and they have an interest in improving lifestyle. Participants will be randomized into e-CUIDATE or usual care groups. E-CUIDATE give participants access to a range of contents: planning exercise arranged in series with breathing exercises, mobility, strength, and stretching. All of these exercises will be assigned to women in the telerehabilitation group according to perceived needs. The control group will be asked to maintain their usual routine. Study endpoints will be assessed after 8 weeks (immediate effects) and after 6 months. The primary outcome will be QoL measured by The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 version 3.0 and breast module called The European Organization for Research and Treatment of Cancer Breast Cancer-Specific Quality of Life questionnaire. The secondary outcomes: pain (algometry, Visual Analogue Scale, Brief Pain Inventory short form); body composition; physical measurement (abdominal test, handgrip strength, back muscle strength, and multiple sit-to-stand test); cardiorespiratory fitness (International Fitness Scale, 6-minute walk test, International Physical Activity Questionnaire-Short Form); fatigue (Piper Fatigue Scale and Borg Fatigue Scale); anxiety and depression (Hospital Anxiety and Depression Scale); cognitive function (Trail Making Test and Auditory Consonant Trigram); accelerometry; lymphedema; and anthropometric perimeters. DISCUSSION This study investigates the feasibility and effectiveness of a telerehabilitation system during adjuvant treatment of patients with breast cancer. If this treatment option is effective, telehealth systems could offer a choice of supportive care to cancer patients during the survivorship phase. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT01801527.
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Mitochondrial impairment is hypothesized to contribute to the pathogenesis of insulin resistance. Mitofusin (Mfn) proteins regulate the biogenesis and maintenance of the mitochondrial network, and when inactivated, cause a failure in the mitochondrial architecture and decreases in oxidative capacity and glucose oxidation. Exercise increases muscle mitochondrial content, size, oxidative capacity and aerobic glucose oxidation. To address if Mfn proteins are implicated in these exercise-induced responses, we measured Mfn1 and Mfn2 mRNA levels, pre-, post-, 2 and 24 h post-exercise. Additionally, we measured the expression levels of transcriptional regulators that control mitochondrial biogenesis and functions, including PGC-1alpha, NRF-1, NRF-2 and the recently implicated ERRalpha. We show that Mfn1, Mfn2, NRF-2 and COX IV mRNA were increased 24 h post-exercise, while PGC-1alpha and ERRalpha mRNA increased 2 h post-exercise. Finally, using in vitro cellular assays, we demonstrate that Mfn2 gene expression is driven by a PGC-1alpha programme dependent on ERRalpha. The PGC-1alpha/ERRalpha-mediated induction of Mfn2 suggests a role of these two factors in mitochondrial fusion. Our results provide evidence that PGC-1alpha not only mediates the increased expression of oxidative phosphorylation genes but also mediates alterations in mitochondrial architecture in response to aerobic exercise in humans