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1.
J Neurol Neurosurg Psychiatry ; 90(8): 882-894, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30852493

RESUMO

The triad of central nervous system symptoms, visual disturbance and hearing impairment is an oft-encountered clinical scenario. A number of immune-mediated diseases should be considered among the differential diagnoses including: Susac syndrome, Cogan syndrome or Vogt-Koyanagi-Harada disease; demyelinating conditions such as multiple sclerosis or neuromyelitis optica spectrum disorder; systemic diseases such as systemic lupus erythematosus, Sjögren syndrome or Behcet disease and granulomatous diseases such as sarcoidosis. In this article, we coin the term 'BEE syndromes' to draw attention to the various immune-mediated diseases that affect the brain, eye and ear. We present common disease manifestations and identify key clinical and investigation features.


Assuntos
Encefalopatias/etiologia , Otopatias/etiologia , Oftalmopatias/etiologia , Doenças do Sistema Imunitário/complicações , Encefalopatias/imunologia , Otopatias/imunologia , Oftalmopatias/imunologia , Humanos , Síndrome
2.
Heliyon ; 10(11): e31615, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38841460

RESUMO

Non-traditional security (NTS) threats have a vast and profound impact on many aspects of economic, political, social, and many other areas, especially supply chain finance (SCF), particularly in countries like Vietnam, which potentially affects the economic efficiency of businesses' supply chain financial, thereby affecting the general economy of the country and the world. In order to prevent and minimize the negative impacts caused by NTS threats to SCF, this study was conducted to identify NTS threats affecting SCF in Vietnam, at the same time calculate the weight of the impact level and find out the cause and effect relationship between them. Solution strategies are also proposed and ranked, thereby serving as a reference basis for relevant parties to choose appropriate response solutions. Due to the multi-criteria nature of NTS threats, the multiple criteria decision-making (MCDM) method is used in combination with the Z-number concept and Fuzzy set theory to approach the problem of certainty and increase the accuracy of study. The NTS threats are first identified through a literature review and then validated for suitability using the DELPHI technique (DELPHI). Suitable threats will be determined by relationship, weighted by Decision Making Trial And Evaluation Laboratory (DEMATEL) method. Proposed strategies are ranked using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. The results indicate that there are 19 NTS factors affecting SCF in Vietnam, and the global economic downturn, pandemic and health crisis, financial crisis and cybersecurity risk are the four root cause factors with the most decisive influence. Businesses and concerns need to prioritize addressing these four threats because they not only have a strong impact but also entail many other threats. The two strategies considered to be the most effective are a sustainable practice and a risk-hedging strategy. Businesses, governments, and stakeholders also should pay attention to the macroeconomic environment, technology, and environment and build sustainable businesses, regularly monitoring economic fluctuations and creating plans to prevent risks.

3.
Brain ; 134(Pt 12): 3516-29, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22067542

RESUMO

Nemaline myopathy, the most common congenital myopathy, is caused by mutations in genes encoding thin filament and thin filament-associated proteins in skeletal muscles. Severely affected patients fail to survive beyond the first year of life due to severe muscle weakness. There are no specific therapies to combat this muscle weakness. We have generated the first knock-in mouse model for severe nemaline myopathy by replacing a normal allele of the α-skeletal actin gene with a mutated form (H40Y), which causes severe nemaline myopathy in humans. The Acta1(H40Y) mouse has severe muscle weakness manifested as shortened lifespan, significant forearm and isolated muscle weakness and decreased mobility. Muscle pathologies present in the human patients (e.g. nemaline rods, fibre atrophy and increase in slow fibres) were detected in the Acta1(H40Y) mouse, indicating that it is an excellent model for severe nemaline myopathy. Mating of the Acta1(H40Y) mouse with hypertrophic four and a half LIM domains protein 1 and insulin-like growth factor-1 transgenic mice models increased forearm strength and mobility, and decreased nemaline pathologies. Dietary L-tyrosine supplements also alleviated the mobility deficit and decreased the chronic repair and nemaline rod pathologies. These results suggest that L-tyrosine may be an effective treatment for muscle weakness and immobility in nemaline myopathy.


Assuntos
Debilidade Muscular/genética , Músculo Esquelético/patologia , Miopatias da Nemalina/tratamento farmacológico , Miopatias da Nemalina/genética , Tirosina/uso terapêutico , Animais , Modelos Animais de Doenças , Força da Mão , Hipertrofia/genética , Hipertrofia/patologia , Camundongos , Camundongos Transgênicos , Contração Muscular/genética , Debilidade Muscular/tratamento farmacológico , Debilidade Muscular/patologia , Mutação , Miopatias da Nemalina/patologia , Fenótipo
4.
BMJ Neurol Open ; 4(1): e000285, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35663588

RESUMO

Case: A 39-year-old man with thymoma-associated acetylcholine receptor antibody myasthenia gravis (MG) presented with fevers, night sweats, abdominal pain and weight loss. Marked splenomegaly and intra-abdominal lymphadenopathy were found. Biopsies confirmed disseminated Mycobacterium genavense infection. Despite antimicrobials and reduced immunosuppressive medications, he worsened. We suspected a thymoma-associated cytokine inhibitory antibody. The addition of subcutaneous interferon-gamma (IFN-γ) induced clinical and radiological improvement. His antimicrobials were able to be ceased. MG remained stable. Subsequent testing demonstrated an endogenous interleukin-12 (IL-12) inhibitor, likely inhibiting the IL-12/IFN-γ axis crucial for defence against mycobacterial infections. Discussion: This case illustrates the autoimmune manifestations that can occur with thymoma. It illustrates the benefit of exogenous IFN-γ in overcoming the immune deficit. In this case, its use did not exacerbate existing autoimmune disease or trigger others. We raise awareness of the need to consider cytokine pathway defects as a contributing factor to refractory atypical infections in patients with thymoma-associated MG.

5.
Case Stud Chem Environ Eng ; 6: 100245, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37520922

RESUMO

Since the beginning of this outbreak, much evidence stated that the climb in the amount of biomedical waste harmed human health and had adverse effects on the environment. With the increase of cases of COVID-19 all around the globe, the amount of biomedical waste was also constantly rising. Also, many solutions regarding either reducing or recycling biomedical waste. However, the potential global burden of biomedical waste during this pandemic was not yet been analyzed. Herein, we perform a systematic review of literature on these modalities, including mentioning types of biomedical waste, the effect on health, the environment, and methods of handling biomedical waste during this pandemic. A total of 3551 published papers were identified by two databases. In the end, 15 references were selected for this systematic analysis. Most of the included studies focus on research on the impact of medical waste caused by the COVID-19 pandemic on the environment. The total biomedical waste during the COVID-19 pandemic was approximately 16,649.48 tons/day. Most publications agreed that the amount of waste has also increased due to the rapidly rising number of COVID-19 patients. In 15 articles, we identified 2 mentioning the COVID-19 biomedical waste on health. 9 out of 15 gave out the context related to the solution of BMW by COVID-19. More studies, including meta-analyses, are recommended to shed more light on the effects of medical waste on environmental health during the COVID-19 pandemic.

6.
Neurology ; 93(9): 390-405, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31451586

RESUMO

The presentation of a patient with brainstem symptoms and signs invokes a number of common and less common differential diagnoses, and accurate diagnosis can be challenging. We review the major immune-mediated and inflammatory syndromes that can affect the brainstem including multiple sclerosis, neuromyelitis optica spectrum disorder, neuro-Behçet disease, chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids, neurosarcoidosis, Susac syndrome, and the histiocytic disorders. We focus on clinical features and MRI clues that help to distinguish among the different brainstem conditions. Accurate diagnosis is important to guide appropriate treatment and limit neurologic disability.


Assuntos
Doenças Autoimunes do Sistema Nervoso/diagnóstico , Tronco Encefálico/patologia , Inflamação/diagnóstico , Doenças Autoimunes do Sistema Nervoso/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Inflamação/diagnóstico por imagem , Imageamento por Ressonância Magnética
7.
Pharmacol Ther ; 202: 40-52, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31153954

RESUMO

Disease behaviour in interstitial lung disease (ILD) is highly variable and accurate clinical tools to predict prognosis and guide management decisions remain unsatisfactorily elusive. Accurate disease stratification would allow clinicians to better distinguish patients at risk of rapid progression requiring urgent treatment, from those indolent disease where potentially toxic drug therapy could be minimised or avoided. Several serum biomarkers have demonstrated potential utility for diagnosis and prognosis of ILD in small retrospective studies, and the hope is future multicentre prospective trials focussed on the markers with most potential will see translation to clinical practice. Two important and contrasting fibrotic lung diseases with high mortality are idiopathic pulmonary fibrosis (IPF) and systemic sclerosis associated ILD (SSc-ILD). In this era where anti-fibrotics for IPF have proven benefit, there are increasing biologic and non-biologic options for the treatment of connective tissue disease ILD (CTD-ILD), and the incidence of both is increasing, there is an urgent need to improve the diagnostic and prognostic accuracy in these complex patients. This comprehensive literature review will summarise and discuss the current evidence for the major candidate serum biomarkers in IPF and SSc-ILD. Biomarkers will be categorised by the following major mechanistic pathways (1) alveolar epithelial cell damage; (2) aberrant fibrogenesis, fibroproliferation and matrix remodelling; (3) immune dysregulation; and (4) vascular and endothelial damage. The aim is to review the rationale, potential and limitations of current candidate biomarkers and their utility in IPF and SSc-ILD to help direct future research and translation to clinical practice.


Assuntos
Biomarcadores/sangue , Fibrose Pulmonar Idiopática/sangue , Fibrose Pulmonar Idiopática/diagnóstico , Doenças Pulmonares Intersticiais/sangue , Doenças Pulmonares Intersticiais/diagnóstico , Escleroderma Sistêmico/sangue , Animais , Humanos , Estudos Retrospectivos
8.
Endocrinology ; 149(5): 2403-10, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18258678

RESUMO

Stanniocalcin (STC), a secreted glycoprotein, was first studied in fish as a classical hormone with a role in regulating serum calcium levels. There are two closely related proteins in mammals, STC1 and STC2, with functions that are currently unclear. Both proteins are expressed in numerous mammalian tissues rather than being secreted from a specific endocrine gland. No phenotype has been detected yet in Stc1-null mice, and to investigate whether Stc2 could have compensated for the loss of Stc1, we have now generated Stc2(-/-) and Stc1(-/-) Stc2(-/-) mice. Although Stc1 is expressed in the ovary and lactating mouse mammary glands, like the Stc1(-/-) mice, the Stc1(-/-) Stc2(-/-) mice had no detected decrease in fertility, fecundity, or weight gain up until weaning. Serum calcium and phosphate levels were normal in Stc1(-/-) Stc2(-/-) mice, indicating it is unlikely that the mammalian stanniocalcins have a major physiological role in mineral homeostasis. Mice with Stc2 deleted were 10-15% larger and grew at a faster rate than wild-type mice from 4 wk onward, and the Stc1(-/-) Stc2(-/-) mice had a similar growth phenotype. This effect was not mediated through the GH/IGF-I axis. The results are consistent with STC2 being a negative regulator of postnatal growth.


Assuntos
Glicoproteínas/fisiologia , Crescimento e Desenvolvimento/genética , Animais , Animais Recém-Nascidos , Peso Corporal/genética , Desenvolvimento Ósseo/genética , Cruzamentos Genéticos , Feminino , Glicoproteínas/genética , Peptídeos e Proteínas de Sinalização Intercelular , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Atividade Motora/genética , Músculo Esquelético/fisiologia , Tamanho do Órgão/genética , Reprodução/genética , Caracteres Sexuais
9.
Adv Exp Med Biol ; 642: 66-77, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19181094

RESUMO

Thin filament integrity is important for the ordered structure and function of skeletal muscles. Mutations within genes that encode thin filament and thin filament-associated proteins can cause muscle disruption, fiber atrophy and alter fiber type composition, leading to muscle weakness. Analyses of patient biopsy samples and tissue culture systems provide rapid methods for studying disease-causing mutations. However, there are limitations to these techniques. Although time consuming, many laboratories are generating and utilizing animal models, in particular the mouse, to study the disease process of various myopathies. This chapter reviews the use of mouse models for thin filament diseases of skeletal muscle and in particular, concentrates on what has been achieved through the generation and characterization of transgenic and knock-in mouse models for the congenital thin filament disease nemaline myopathy. We will review potential therapies that have been trialled on the nemaline models, providing indications for future directions for the treatment of nemaline myopathy patients and muscle weakness in general.


Assuntos
Fibras Musculares Esqueléticas/metabolismo , Doenças Musculares/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Doenças Musculares/genética , Doenças Musculares/patologia , Mutação/genética
10.
J Clin Med ; 6(5)2017 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-28471413

RESUMO

The diagnosis of interstitial lung disease (ILD) requires meticulous evaluation for an underlying connective tissue disease (CTD), with major implications for prognosis and management. CTD associated ILD (CTD-ILD) occurs most commonly in the context of an established CTD, but can be the first and/or only manifestation of an occult CTD or occur in patients who have features suggestive of an autoimmune process, but not meeting diagnostic criteria for a defined CTD-recently defined as "interstitial pneumonia with autoimmune features" (IPAF). The detection of specific autoantibodies serves a critical role in the diagnosis of CTD-ILD, but there remains a lack of data to guide clinical practice including which autoantibodies should be tested on initial assessment and when or in whom serial testing should be performed. The implications of detecting autoantibodies in patients with IPAF on disease behaviour and management remain unknown. The evaluation of CTD-ILD is challenging due to the heterogeneity of presentations and types of CTD and ILD that may be encountered, and thus it is imperative that immunologic tests are interpreted in conjunction with a detailed rheumatologic history and examination and multidisciplinary collaboration between respiratory physicians, rheumatologists, immunologists, radiologists and pathologists.

11.
Artigo em Inglês | MEDLINE | ID: mdl-16473567

RESUMO

The use of multi-factor statistical experimental design methodology minimized the vaccine material and laboratory resources required for optimization and validation of an HPLC assay for quantitation of depolymerized and total PRP. Components of the assay selected for optimization were adjuvant dissolution, ultracentrifuge conditions including ultracentrifuge model, sample diluent, mobile phase and column oven temperature. Previous experience has shown these components of the assay to be most troublesome and therefore required optimization prior to validation. Specificity, linearity, precision, accuracy and ruggedness were confirmed through a validation of the optimized assay. The validation also established the assay to be stability indicating, by showing that changes to the integrity of the PRP-OMPC conjugate could be detected.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Polissacarídeos/análise , Vacinas Combinadas/química , Ultracentrifugação
12.
Dev Comp Immunol ; 26(7): 599-602, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12074924

RESUMO

Marsupials, unlike eutherians, are born immunologically immature, without circulating lymphocytes or organised lymphoid tissue. Their immune response develops while they are in the pouch not in the uterus. In this study, the onset time of immunoglobulin expression in Trichosurus vulpecula pouch young was estimated by reverse transcription polymerase chain reaction. As in eutherian species, IgM heavy chain transcripts were detected first, at day 10 post partum. The first switched transcript, detected at day 18, was Calpha. Cgamma and Cvarepsilon transcripts were not present at day 72, but were seen at day 103, approximately corresponding to the time of release of the teat and exposure to new antigens, as well as the time of the loss of capacity to absorb maternal Igs through the gut.


Assuntos
Cadeias Pesadas de Imunoglobulinas/genética , Gambás/imunologia , Animais , Perfilação da Expressão Gênica , Regiões Constantes de Imunoglobulina/genética , Imunoglobulina M/genética , Cadeias épsilon de Imunoglobulina/genética , Cadeias gama de Imunoglobulina/genética , Cadeias mu de Imunoglobulina/genética , Gambás/genética
13.
J Cell Biol ; 183(6): 1033-48, 2008 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19075112

RESUMO

Regulators of skeletal muscle mass are of interest, given the morbidity and mortality of muscle atrophy and myopathy. Four-and-a-half LIM protein 1 (FHL1) is mutated in several human myopathies, including reducing-body myopathy (RBM). The normal function of FHL1 in muscle and how it causes myopathy remains unknown. We find that FHL1 transgenic expression in mouse skeletal muscle promotes hypertrophy and an oxidative fiber-type switch, leading to increased whole-body strength and fatigue resistance. Additionally, FHL1 overexpression enhances myoblast fusion, resulting in hypertrophic myotubes in C2C12 cells, (a phenotype rescued by calcineurin inhibition). In FHL1-RBM C2C12 cells, there are no hypertrophic myotubes. FHL1 binds with the calcineurin-regulated transcription factor NFATc1 (nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1), enhancing NFATc1 transcriptional activity. Mutant RBM-FHL1 forms aggregate bodies in C2C12 cells, sequestering NFATc1 and resulting in reduced NFAT nuclear translocation and transcriptional activity. NFATc1 also colocalizes with mutant FHL1 to reducing bodies in RBM-afflicted skeletal muscle. Therefore, via NFATc1 signaling regulation, FHL1 appears to modulate muscle mass and strength enhancement.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Musculares/metabolismo , Músculo Esquelético/patologia , Doenças Musculares/patologia , Animais , Calcineurina/metabolismo , Fusão Celular , Fator de Transcrição GATA2/metabolismo , Humanos , Hipertrofia , Proteínas com Domínio LIM , Camundongos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/metabolismo , Doenças Musculares/metabolismo , Mutação/genética , Mioblastos/metabolismo , Mioblastos/patologia , Fatores de Transcrição NFATC/metabolismo , Tamanho do Órgão , Ligação Proteica , Transdução de Sinais , Transcrição Gênica , Ativação Transcricional
14.
Hum Mol Genet ; 15(17): 2603-12, 2006 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-16877500

RESUMO

Nemaline myopathy (NM), the most common non-dystrophic congenital myopathy, is a variably severe neuromuscular disorder for which no effective treatment is available. Although a number of genes have been identified in which mutations can cause NM, the pathogenetic mechanisms leading to the phenotypes are poorly understood. To address this question, we examined gene expression patterns in an NM mouse model carrying the human Met9Arg mutation of alpha-tropomyosin slow (Tpm3). We assessed five different skeletal muscles from affected mice, which are representative of muscles with differing fiber-type compositions, different physiological specializations and variable degrees of pathology. Although these same muscles in non-affected mice showed marked variation in patterns of gene expression, with diaphragm being the most dissimilar, the presence of the mutant protein in nemaline muscles resulted in a more similar pattern of gene expression among the muscles. This result suggests a common process or mechanism operating in nemaline muscles independent of the variable degrees of pathology. Transcriptional and protein expression data indicate the presence of a repair process and possibly delayed maturation in nemaline muscles. Markers indicative of satellite cell number, activated satellite cells and immature fibers including M-Cadherin, MyoD, desmin, Pax7 and Myf6 were elevated by western-blot analysis or immunohistochemistry. Evidence suggesting elevated focal repair was observed in nemaline muscle in electron micrographs. This analysis reveals that NM is characterized by a novel repair feature operating in multiple different muscles.


Assuntos
Músculo Esquelético/patologia , Miopatias da Nemalina/metabolismo , Miopatias da Nemalina/patologia , Animais , Progressão da Doença , Perfilação da Expressão Gênica , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica , Músculo Esquelético/metabolismo , Músculo Esquelético/ultraestrutura , Miofibrilas/metabolismo , Miofibrilas/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Transdução de Sinais
15.
J Biol Chem ; 281(11): 7666-83, 2006 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-16407297

RESUMO

Four and a half LIM protein 1 (FHL1/SLIM1) is highly expressed in skeletal and cardiac muscle; however, the function of FHL1 remains unknown. Yeast two-hybrid screening identified slow type skeletal myosin-binding protein C as an FHL1 binding partner. Myosin-binding protein C is the major myosin-associated protein in striated muscle that enhances the lateral association and stabilization of myosin thick filaments and regulates actomyosin interactions. The interaction between FHL1 and myosin-binding protein C was confirmed using co-immunoprecipitation of recombinant and endogenous proteins. Recombinant FHL2 and FHL3 also bound myosin-binding protein C. FHL1 impaired co-sedimentation of myosin-binding protein C with reconstituted myosin filaments, suggesting FHL1 may compete with myosin for binding to myosin-binding protein C. In intact skeletal muscle and isolated myofibrils, FHL1 localized to the I-band, M-line, and sarcolemma, co-localizing with myosin-binding protein C at the sarcolemma in intact skeletal muscle. Furthermore, in isolated myofibrils FHL1 staining at the M-line appeared to extend partially into the C-zone of the A-band, where it co-localized with myosin-binding protein C. Overexpression of FHL1 in differentiating C2C12 cells induced "sac-like" myotube formation (myosac), associated with impaired Z-line and myosin thick filament assembly. This phenotype was rescued by co-expression of myosin-binding protein C. FHL1 knockdown using RNAi resulted in impaired myosin thick filament formation associated with reduced incorporation of myosin-binding protein C into the sarcomere. This study identified FHL1 as a novel regulator of myosin-binding protein C activity and indicates a role for FHL1 in sarcomere assembly.


Assuntos
Proteínas de Transporte/fisiologia , Proteínas Musculares/fisiologia , Miosinas/química , Sarcômeros/metabolismo , Actomiosina/química , Sequência de Aminoácidos , Animais , Sequência de Bases , Células COS , Proteínas de Transporte/metabolismo , Diferenciação Celular , Proliferação de Células , Chlorocebus aethiops , Eletroforese em Gel de Poliacrilamida , Glutationa Transferase/metabolismo , Humanos , Imuno-Histoquímica , Imunoprecipitação , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas com Domínio LIM , Camundongos , Microscopia de Fluorescência , Dados de Sequência Molecular , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Miócitos Cardíacos/metabolismo , Oligonucleotídeos/química , Peptídeos/química , Fenótipo , Ligação Proteica , Estrutura Terciária de Proteína , Interferência de RNA , Proteínas Recombinantes/química , Homologia de Sequência de Aminoácidos , Transfecção , Técnicas do Sistema de Duplo-Híbrido
16.
J Am Chem Soc ; 126(7): 2058-65, 2004 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-14971940

RESUMO

A long lasting challenge in polymer science is to design polymers that combine desired mechanical properties such as tensile strength, fracture toughness, and elasticity into one structure. A novel biomimetic modular polymer design is reported here to address this challenge. Following the molecular mechanism used in nature, modular polymers containing multiple loops were constructed by using precise and strong hydrogen bonding units. Single-molecule force-extension experiments revealed the sequential unfolding of loops as a chain is stretched. The excellent correlation between the single-molecule and the bulk properties successfully demonstrates our biomimetic concept of using modular domain structure to achieve advanced polymer properties.


Assuntos
Materiais Biomiméticos/química , Polímeros/química , Materiais Biomiméticos/síntese química , Modelos Químicos , Modelos Moleculares , Polímeros/síntese química
17.
Hum Mol Genet ; 13(21): 2633-45, 2004 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-15367485

RESUMO

Patients with the inherited muscle disease nemaline myopathy experience prolonged muscle weakness following periods of immobility. We have examined endurance exercise as a means of improving recovery following muscle inactivity in our alpha-tropomyosin(slow)(Met9Arg)-transgenic mouse model of nemaline myopathy. Physical inactivity, mimicked using a hindlimb immobilization protocol, resulted in fiber atrophy and severe muscle weakness. Following immobilization, the nemaline mice (NM) were weaker than WT mice but regained whole-body strength with exercise training. The disuse-induced weakness and the regain of strength with exercise in NM were associated with the respective formation and resolution of nemaline rods, suggesting a role for rods in muscle weakness. Muscles from NM did not show the typical features of muscle repair during chronic stretch-immobilization of the soleus muscle (regeneration occurred with relative lack of centralized nuclei). This indicates that the normal process of regeneration may be altered in nemaline myopathy and may contribute to poor recovery. In conclusion, endurance exercise can alleviate disuse-induced weakness in NM. The altered myofiber repair process in the nemaline mice may be a response to primary myofibrillar damage that occurs in nemaline myopathy and is distinct from the classical repair in muscular dystrophy resulting from plasma membrane defects.


Assuntos
Fibras Musculares de Contração Lenta/fisiologia , Debilidade Muscular/fisiopatologia , Miopatias da Nemalina/fisiopatologia , Condicionamento Físico Animal , Animais , Modelos Animais de Doenças , Eletroforese em Gel de Poliacrilamida , Humanos , Imobilização/métodos , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Debilidade Muscular/genética , Debilidade Muscular/patologia , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Músculo Esquelético/ultraestrutura , Miopatias da Nemalina/genética , Cadeias Pesadas de Miosina/química , Cadeias Pesadas de Miosina/metabolismo , Resistência Física/fisiologia , Fatores de Tempo
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