Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
Transpl Int ; 36: 10765, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36744053

RESUMEN

Kidney transplant recipients develop atypical infections in their epidemiology, presentation and outcome. Among these, meningitis and meningoencephalitis require urgent and adapted anti-infectious therapy, but published data is scarce in KTRs. The aim of this study was to describe their epidemiology, presentation and outcome, in order to improve their diagnostic and management. We performed a retrospective, multicentric cohort study in 15 French hospitals that included all 199 cases of M/ME in KTRs between 2007 and 2018 (0.9 case per 1,000 KTRs annually). Epidemiology was different from that in the general population: 20% were due to Cryptococcus neoformans, 13.5% to varicella-zoster virus, 5.5% to Mycobacterium tuberculosis, and 4.5% to Enterobacteria (half of which produced extended spectrum beta-lactamases), and 5% were Post Transplant Lymphoproliferative Disorders. Microorganisms causing M/ME in the general population were infrequent (2%, for Streptococcus pneumoniae) or absent (Neisseria meningitidis). M/ME caused by Enterobacteria, Staphylococci or filamentous fungi were associated with high and early mortality (50%-70% at 1 year). Graft survival was not associated with the etiology of M/ME, nor was impacted by immunosuppression reduction. Based on these results, we suggest international studies to adapt guidelines in order to improve the diagnosis and the probabilistic treatment of M/ME in SOTRs.


Asunto(s)
Encefalitis , Trasplante de Riñón , Meningitis , Humanos , Estudios Retrospectivos , Estudios de Cohortes , Trasplante de Riñón/efectos adversos , Meningitis/complicaciones , Meningitis/diagnóstico , Encefalitis/diagnóstico , Encefalitis/epidemiología , Encefalitis/etiología
2.
Open Forum Infect Dis ; 10(2): ofad018, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36817745

RESUMEN

Background: Prolonged (val)ganciclovir [(V)GCV] exposure for ≥6 weeks is a known predisposing factor for cytomegalovirus (CMV) drug resistance. However, the selection of this threshold was based on limited data. In this study, we sought to reappraise the risk factors for the development of (V)GCV resistance through a specific focus on kidney transplant recipients (KTRs). Methods: This single-center retrospective study included 313 consecutive KTRs treated for a first CMV episode. Adjusted Cox multivariate regression analysis was used for identifying independent risk factors. Results: Antiviral drug resistance was identified in 20 (6%) KTRs. A cumulative (V)GCV exposure for more than 6 weeks (regardless of the viral load) was not associated with antiviral drug resistance (hazard ratio [HR] = 2.45, 95% confidence interval [CI] = 0.33-18.30, P = .38). In contrast, persistent CMV DNAemia requiring (V)GCV treatment for more than 8 weeks was the main independent risk factor for antiviral drug resistance (HR = 11.68, 95% CI = 2.62-52.01, P = .001). The (V)GCV treatment for more than 8 weeks was given to 9% and 18% of patients who had persistent or recurrent CMV DNAemia, respectively. These scenarios were associated with the occurrence of drug resistance in 39% and 12% of cases, respectively. Conclusions: Cumulative (V)GCV exposure ≥6 weeks regardless of the viral load is not associated with antiviral drug resistance. In contrast, prolonged exposure to (V)GCV during CMV replication (with a cutoff ³8 weeks) seems to be a key factor.

3.
Rev Neurol (Paris) ; 175(5): 291-297, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30902429

RESUMEN

Transnational exchanges have existed for centuries, with both economic and cultural effects. At the end of the 18th century, in the aftermath of the French Revolution, medical education in France underwent radical innovations, prefiguring the training system now almost universally accepted. This paper presents 19th and early 20th century neurology-related exchanges between the United States (US) and Europe, particularly, Paris, which had become a major medical center and where many US neurologists were trained. We discuss some of the intense neurology-related exchanges between the USA and Europe, notably the role of US neurology founders William Alexander Hammond, Silas Weir Mitchell, Edward Seguin as well as Mauritius-born Charles Edouard Brown-Séquard and a few others. We emphasize the mutual benefits that resulted from such exchanges. In later years, the trend reversed with many foreigners, particularly Europeans coming to improve their knowledge in the US. More recently, a shared pattern of travel and enrichment is occurring despite current threats caused by isolationism and undue stress on local identity.


Asunto(s)
Intercambio Educacional Internacional/historia , Neurología/educación , Francia , Historia del Siglo XIX , Historia del Siglo XX , Estados Unidos
5.
Obes Rev ; 18(12): 1425-1438, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28960764

RESUMEN

INTRODUCTION: Social marketing is a promising planning approach for influencing voluntary lifestyle behaviours, but its application to nutrition and physical activity interventions in the early care and education setting remains unknown. METHODS: PubMed, ISI Web of Science, PsycInfo and the Cumulative Index of Nursing and Allied Health were systematically searched to identify interventions targeting nutrition and/or physical activity behaviours of children enrolled in early care centres between 1994 and 2016. Content analysis methods were used to capture information reflecting eight social marketing benchmark criteria. RESULTS: The review included 135 articles representing 77 interventions. Two interventions incorporated all eight benchmark criteria, but the majority included fewer than four. Each intervention included behaviour and methods mix criteria, and more than half identified audience segments. Only one-third of interventions incorporated customer orientation, theory, exchange and insight. Only six interventions addressed competing behaviours. We did not find statistical significance for the effectiveness of interventions on child-level diet, physical activity or anthropometric outcomes based on the number of benchmark criteria used. CONCLUSION: This review highlights opportunities to apply social marketing to obesity prevention interventions in early care centres. Social marketing could be an important strategy for early childhood obesity prevention efforts, and future research investigations into its effects are warranted.


Asunto(s)
Guarderías Infantiles/normas , Dieta , Ejercicio Físico , Política Nutricional , Mercadeo Social , Benchmarking , Cuidado del Niño/normas , Preescolar , Humanos
6.
Eur J Neurol ; 23(8): 1372-9, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27185333

RESUMEN

BACKGROUND AND PURPOSE: Glucocorticoids (GCs) are the mainstay treatment of myasthenia gravis (MG). However, wide inter-individual variability exists in the response to GCs. METHODS: A Chinese cohort of 257 MG patients treated with GCs was evaluated for the association between 19 single nucleotide polymorphisms in the GR gene and clinical response to the initial 3 month GC therapy. A quantitative MG score decreasing by ≥3 units or becoming zero was defined as sensitivity to GCs. RESULTS: The rs17209237* G allele was less frequent in the GC insensitive group compared with the GC sensitive group [P = 0.013, odds ratio (OR) 0.119]. The rs9324921* A allele was more frequent in the GC insensitive group than in the GC sensitive group (P = 0.046, OR 1.94). Carriers of the rs17209237 G allele were less frequent in the GC insensitive group than in the GC sensitive group (dominant model, P = 0.009). Carriers of the rs9324921 A allele were more frequent in the GC insensitive group than in the GC sensitive group (dominant model, P = 0.037). Multivariate logistic regression revealed that the rs17209237 G allele carrier (P = 0.037, OR 0.12) and disease duration before GC treatment (P = 0.011, OR 3.45) were independent factors that contributed to GC efficacy. CONCLUSION: rs17209237 in the GR gene was identified as an independent factor that contributes to GC efficacy in MG patients. The genetic variations of the GR gene may play a role in predicting response to GC treatment.


Asunto(s)
Glucocorticoides/uso terapéutico , Miastenia Gravis/tratamiento farmacológico , Miastenia Gravis/genética , Polimorfismo de Nucleótido Simple , Receptores de Glucocorticoides/genética , Adulto , Alelos , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Farmacogenética
7.
Am J Transplant ; 16(8): 2384-94, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-26953216

RESUMEN

Universal prophylaxis for cytomegalovirus (CMV) prevention is viable but, compared with a preemptive strategy, leads to higher incidence of late-onset disease (LOD) associated with poor patient and graft survival. The purpose of this study was to compare LOD with early onset disease (EOD), with a focus on the highest risk kidney transplant recipients (KTRs): CMV seronegative recipients transplanted from seropositive donors (D+R-). Since CMV control depends on both antiviral treatment and specific immune response, we also compared Vδ2-negative (Vδ2(neg) ) γδ T cell expansion involved in CMV infection resolution. EOD was defined as occurring <3 mo and LOD as occurring >3 mo after transplantation. Depending on the period, universal prophylaxis or preemptive treatment was used. Overall, 168 D+R- KTRs were included between 2003 and 2011. LOD was associated with a lower peak DNAemia (p = 0.04), fewer recurrences (odds ratio 0.16; 95% confidence interval 0.05-0.55; p = 0.01) and shorter anti-CMV curative treatment (40 vs. 60 days, p < 0.0001). As a corollary, we found that Vδ2(neg) γδ T cell expansion was faster in LOD than in EOD (31 vs. 168 days after the beginning of CMV disease, p < 0.0001). In D+R- KTRs, universal prophylaxis is associated with more LOD, which had better infection management and a faster immune response. These results support the use of universal prophylaxis over a preemptive strategy and reappraise outcomes of LOD.


Asunto(s)
Antivirales/farmacología , Infecciones por Citomegalovirus/inmunología , Citomegalovirus/inmunología , Supervivencia de Injerto/inmunología , Fallo Renal Crónico/cirugía , Trasplante de Riñón , Linfocitos T/inmunología , Edad de Inicio , Infecciones por Citomegalovirus/tratamiento farmacológico , Infecciones por Citomegalovirus/virología , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Supervivencia de Injerto/efectos de los fármacos , Humanos , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Linfocitos T/efectos de los fármacos , Donantes de Tejidos
8.
Am J Transplant ; 16(8): 2254-69, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-26991039

RESUMEN

Interpretation of clinical data regarding the impact of cytomegalovirus (CMV) infection on allograft function is complicated by the diversity of viral strains and substantial variability of cellular receptors and viral gene expression in different tissues. Variation also exists in nonspecific (monocytes and dendritic cells) and specific (NK cells, antibodies) responses that augment T cell antiviral activities. Innate immune signaling pathways and expanded pools of memory NK cells and γδ T cells also serve to amplify host responses to infection. The clinical impact of specific memory T cell anti-CMV responses that cross-react with graft antigens and alloantigens is uncertain but appears to contribute to graft injury and to the abrogation of allograft tolerance. These responses are modified by diverse immunosuppressive regimens and by underlying host immune deficits. The impact of CMV infection on the transplant recipient reflects cellular changes and corresponding host responses, the convergence of which has been termed the "indirect effects" of CMV infection. Future studies will clarify interactions between CMV infection and allograft injury and will guide interventions that may enhance clinical outcomes in transplantation.


Asunto(s)
Infecciones por Citomegalovirus/inmunología , Citomegalovirus/inmunología , Rechazo de Injerto/prevención & control , Inmunidad Celular/inmunología , Trasplante de Órganos/efectos adversos , Linfocitos T/inmunología , Infecciones por Citomegalovirus/patología , Infecciones por Citomegalovirus/virología , Rechazo de Injerto/inmunología , Rechazo de Injerto/virología , Humanos , Linfocitos T/patología , Linfocitos T/virología
9.
Transplant Proc ; 45(4): 1603-7, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23726629

RESUMEN

Maribavir (MBV), a UL97 inhibitor, shows good oral bioavailability, low host cell toxicity, and theoretical benefits to inhibit cross-resistant viruses. We herein examined clinical and virological outcomes of 12 patients, including 3 bone marrow recipients and 9 organ recipients infected with resistant cytomegalovirus (CMV) and treated with MBV during 2011-2012. All received at least 800-mg daily doses. They had developed clinical (12/12) and/or virological (11/12) resistance to CMV infection. Based on a decrease of viral load in blood >1.5 log copies/mL half of them responded to MBV treatment. The individual changes varied from a rapid decrease in viral load (n = 4) to no response (n = 3) with some late response slowly decreasing viremia (n = 3). In 2 cases MBV was used as secondary prophylaxis. No clear parameter emerged as a clinical surrogate for nonresponse to MBV. These results contrast with the lack of efficacy in phase III trials of MBV prophylaxis among stem cell recipients, which were possibly due to low doses or inadequate timing of drug initiation in the study. Additional clinical and surrogate laboratory markers are needed to determine antiviral responses to guide MBV use. Dosage ranging studies might benefit future MBV use.


Asunto(s)
Antivirales/uso terapéutico , Bencimidazoles/uso terapéutico , Infecciones por Citomegalovirus/tratamiento farmacológico , Trasplante de Órganos , Ribonucleósidos/uso terapéutico , Adulto , Antivirales/farmacología , Bencimidazoles/farmacología , Citomegalovirus/efectos de los fármacos , Francia , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Ribonucleósidos/farmacología
10.
Acta Physiol (Oxf) ; 207(4): 721-31, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23347696

RESUMEN

AIM: In the present study, we aimed to elucidate the effects of chronic vasopressin administration on renal medullary oxygen levels. METHODS: Adult Sprague Dawley or vasopressin-deficient Brattleboro rats were treated with the vasopressin V2 receptor agonist, desmopressin (5 ng/h; 3d), or its vehicle via osmotic minipumps. Immunostaining for pimonidazole and the transcription factor HIF-1α (hypoxia-inducible factor-1α) were used to identify hypoxic areas. Activation of HIF-target gene expression following desmopressin treatment was studied by microarray analysis. RESULTS: Pimonidazole staining was detected in the outer and inner medulla of desmopressin-treated rats, whereas staining in control animals was weak or absent. HIF-1α immunostaining demonstrated nuclear accumulation in the papilla of desmopressin-treated animals, whereas no staining was observed in the controls. Gene expression analysis revealed significant enrichment of HIF-target genes in the group of desmopressin-regulated gene products (P = 2.6*10(-21) ). Regulated products included insulin-like growth factor binding proteins 1 and 3, angiopoietin 2, fibronectin, cathepsin D, hexokinase 2 and cyclooxygenase 2. CONCLUSION: Our results demonstrate that an activation of the renal urine concentrating mechanism by desmopressin causes renal medullary hypoxia and an upregulation of hypoxia-inducible gene expression.


Asunto(s)
Hipoxia/metabolismo , Médula Renal/metabolismo , Oxígeno/metabolismo , Receptores de Vasopresinas/fisiología , Transducción de Señal/fisiología , Animales , Desamino Arginina Vasopresina/farmacología , Modelos Animales de Enfermedad , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Médula Renal/efectos de los fármacos , Nitroimidazoles/metabolismo , Ratas , Ratas Brattleboro , Ratas Sprague-Dawley , Receptores de Vasopresinas/agonistas , Receptores de Vasopresinas/efectos de los fármacos , Vasopresinas/deficiencia , Vasopresinas/genética , Vasopresinas/metabolismo
11.
Neurology ; 72(18): 1548-54, 2009 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-19414721

RESUMEN

OBJECTIVE: To determine the incidence and mortality rates and predictors of death in myasthenia gravis (MG) and MG crisis in a large US cohort. METHODS: Our cohort was identified from the Nationwide Inpatient Sample database for the years 2000 through 2005 using ICD-9-CM codes. MG crisis was identified by the principal diagnosis code or by the presence of respiratory failure. The incidence of MG was stratified by age, ethnicity, and gender. Multivariate logistic regression analysis was used to identify predictors of mortality in MG. For trend analyses of immune intervention, we used the Cochrane-Armitage test. RESULTS: After data cleansing, 5,502 patients with MG were included. In women, the incidence of admission was two to three times higher during the first 5 decades. In men, the incidence of admission was higher during the sixth, seventh, and eighth decades. The annual incidence rate of MG was higher in black women (0.01 per 1,000 persons/year) compared to white women and white and black men (0.009, 0.008, and 0.007 per 1,000 persons/year). The overall in-hospital mortality rate was 2.2%, being higher in MG crisis (4.47%). Older age and respiratory failure were the predictors of death, with adjusted odds ratios of 9.28 (95% confidence interval [CI], 3.31, 26.0) and 3.58 (95% CI, 2.01, 6.38). The trend of i.v. immunoglobulin utilization has increased compared to plasma exchange and thymectomy (p < 0.0001). CONCLUSION: Myasthenia gravis (MG) is still a disease of young women and old men, as reflected by the hospital admission rates. In-hospital mortality of MG is low. Hospital utilization of i.v. immunoglobulin has significantly increased compared to plasma exchange and thymectomy.


Asunto(s)
Miastenia Gravis/epidemiología , Insuficiencia Respiratoria/mortalidad , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Comorbilidad , Femenino , Hospitales/estadística & datos numéricos , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Incidencia , Masculino , Persona de Mediana Edad , Mortalidad , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatología , Miastenia Gravis/tratamiento farmacológico , Miastenia Gravis/mortalidad , Grupos Raciales , Músculos Respiratorios/metabolismo , Músculos Respiratorios/fisiopatología , Distribución por Sexo , Estados Unidos/epidemiología , Adulto Joven
12.
Cochrane Database Syst Rev ; (2): CD005081, 2006 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-16625623

RESUMEN

BACKGROUND: Approximately 50% of people with myasthenia gravis present initially with purely ocular symptoms, so called ocular myasthenia and between 50 to 60% of these people will progress to develop generalized disease. The vast majority will do so within the first one to two years. There is controversy surrounding the appropriate management of patients with ocular myasthenia. OBJECTIVES: To perform a systematic review of the literature relevant to the treatment of ocular myasthenia and to answer three specific questions. Are there any medical or surgical treatments that have an impact on the risk of progression from ocular to generalized myasthenia gravis? Are there any medical or surgical treatments that improve symptoms of diplopia or ptosis in ocular myasthenia? What is the frequency of side effects associated with treatments used in people with ocular myasthenia? SEARCH STRATEGY: We searched the Cochrane Neuromuscular Disease Group Trials Register (searched December 2004), MEDLINE (1996 to 2004) and EMBASE (1980 to 2004) for randomized controlled trials as well as case-control and cohort studies. The titles and abstracts of all articles were read by both authors and the full text of all articles that were of possible relevance was reviewed in full. The references of all manuscripts included in the review were scanned to identify additional articles of relevance and experts in the field were contacted to identify additional published and unpublished data. Where necessary and possible, we contacted authors for further information. SELECTION CRITERIA: To be included in the review, studies had to meet three criteria: (a) randomized (or quasi-randomized) controlled study design; (b) active treatment compared to placebo, no treatment or some other treatment; and (c) results reported separately for patients with ocular myasthenia (grade 1) as defined by the Myasthenia Gravis Foundation of America. DATA COLLECTION AND ANALYSIS: We collected data regarding the risk of progression to generalized myasthenia gravis, improvement in ocular symptoms, and the frequency of treatment-related side effects. MAIN RESULTS: We identified two randomized controlled trials relevant to the treatment of ocular myasthenia, only one of which reported results in terms of the pre-specified outcome measures used in this review. This study included only three participants and was of limited methodological quality. In the absence of data from randomized controlled trials, we present a review of the available observational data. AUTHORS' CONCLUSIONS: There are no data from randomized controlled trials on the impact of any form of treatment on the risk of progression from ocular to generalized myasthenia gravis. The available randomized controlled literature does not permit any meaningful conclusions about the efficacy of any form of treatment for ocular myasthenia. Data from several reasonably good quality observational studies suggest that corticosteroids and azathioprine may be beneficial in reducing the risk of progression to generalized myasthenia gravis.


Asunto(s)
Inhibidores de la Colinesterasa/uso terapéutico , Miastenia Gravis/tratamiento farmacológico , Músculos Oculomotores , Hormona Adrenocorticotrópica/efectos adversos , Hormona Adrenocorticotrópica/uso terapéutico , Inhibidores de la Colinesterasa/efectos adversos , Humanos , Miastenia Gravis/cirugía , Neostigmina/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto
14.
Science ; 308(5718): 92-5, 2005 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-15802600

RESUMEN

Creep damage by void nucleation and growth limits the lifetime of components subjected to loading at high temperatures. We report a combined tomography and diffraction experiment using high-energy synchrotron radiation that permitted us to follow in situ void growth and microstructure development in bulk samples. The results reveal that void growth versus time follows an exponential growth law. The formation of large void volumes coincides with texture evolution and dislocation density, reaching a steady state. Creep damage during a large proportion of sample creep life is homogeneous before damage localization occurs, which leads to rapid failure. The in situ determination of void evolution in bulk samples should allow for the assessment of creep damage in metallic materials and subsequently for lifetime predictions about samples and components that are subject to high-temperature loading.

17.
Proc Natl Acad Sci U S A ; 98(21): 12062-7, 2001 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-11572940

RESUMEN

Skeletal muscle fibers are defined by patterned covariation of key traits that determine contractile and metabolic characteristics. Although the functional properties of most skeletal muscles result from their proportional content of a few conserved muscle fiber types, some, typically craniofacial, muscles exhibit fiber types that appear to lie outside the common phenotypic range. We analyzed gene expression profiles of three putative muscle classes, limb, masticatory, and extraocular muscle (EOM), in adult mice by high-density oligonucleotide arrays. Pairwise comparisons using conservative acceptance criteria identified expression differences in 287 genes between EOM and limb and/or masticatory muscles. Use of significance analysis of microarrays methodology identified up to 400 genes as having an EOM-specific expression pattern. Genes differentially expressed in EOM reflect key aspects of muscle biology, including transcriptional regulation, sarcomeric organization, excitation-contraction coupling, intermediary metabolism, and immune response. These patterned differences in gene expression define EOM as a distinct muscle class and may explain the unique response of these muscles in neuromuscular diseases.


Asunto(s)
Expresión Génica , Músculos Oculomotores/metabolismo , Animales , Perfilación de la Expresión Génica , Masculino , Músculos Masticadores/inmunología , Músculos Masticadores/metabolismo , Ratones , Ratones Endogámicos C57BL , Músculo Esquelético/inmunología , Músculo Esquelético/metabolismo , Enfermedades Neuromusculares/genética , Músculos Oculomotores/inmunología , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Fenotipo , Transducción de Señal , Factores de Transcripción/genética
18.
Neuromuscul Disord ; 11(6-7): 517-24, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11525879

RESUMEN

Nitric oxide is a ubiquitous cell-signaling molecule involved in regulation of numerous homeostatic mechanisms and in mediation of tissue injury. Nitric oxide influences contraction, blood flow, and metabolism, as well as myogenesis. Nitric oxide exerts its influence by activation of guanylate cyclase and nitrosylation of proteins, which include glyceraldehyde-3-phosphate dehydrogenase, the ryanodine receptor and actomyosin ATPase. Skeletal muscle expresses all three isoforms of the nitric oxide synthase, including a muscle-specific splice variant; expression of the isoforms is fiber-type specific and influenced by age and disease. Nitric oxide produced with certain systemic conditions and local inflammation is likely toxic to skeletal muscle, either directly or in reactions with oxygen-derived radicals. Although nitric oxide impacts on many functions in muscle, its effects are subtle, and much work remains to be done to determine its importance in the pathogenesis of muscle diseases.


Asunto(s)
Músculo Esquelético/metabolismo , Enfermedades Musculares/metabolismo , Óxido Nítrico/metabolismo , Animales , Humanos
19.
FASEB J ; 15(10): 1764-70, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11481224

RESUMEN

Extraocular muscles (EOMs) are specialized skeletal muscles that are constantly active, generate low levels of force for cross sectional area, have rapid contractile speeds, and are highly fatigue resistant. The neuronal isoform of nitric oxide synthase (nNOS) is concentrated at the sarcolemma of fast-twitch muscles fibers, and nitric oxide (NO) modulates contractility. This study evaluated nNOS expression in EOM and the effect of NO modulation on lateral rectus muscle's contractility. nNOS activity was highest in EOM compared with diaphragm, extensor digitorum longus, and soleus. Neuronal NOS was concentrated to the sarcolemma of orbital and global singly innervated fibers, but not evident in the multi-innervated fibers. The NG-nitro-L-arginine methyl ester (L-NAME, a NOS inhibitor), increased submaximal tetanic and peak twitch forces. The NO donors S-nitroso-N-acetylcysteine (SNAC) and spermineNONOate reduced submaximal tetanic and peak twitch forces. The effect of NO on the contractile force of lateral rectus muscle is greater than previously observed on other skeletal muscle. NO appears more important in modulating contraction of EOM compared with other skeletal muscles, which could be important for the EOM's specialized role in generation of eye movements.


Asunto(s)
Movimientos Oculares , Contracción Muscular/efectos de los fármacos , Músculo Esquelético/fisiología , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/fisiología , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacología , Animales , Inhibidores Enzimáticos/farmacología , Femenino , Histocitoquímica , Fibras Musculares Esqueléticas/enzimología , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/enzimología , NADPH Deshidrogenasa/análisis , NG-Nitroarginina Metil Éster/farmacología , Donantes de Óxido Nítrico/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo I , Óxidos de Nitrógeno , Ratas , Ratas Endogámicas Lew , Sarcolema/enzimología , Espermina/análogos & derivados , Espermina/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...