用动力学模型定量分析低钠透析液对钠清除量的影响

目的　定量地分析低钠透析液对钠清除量的影响以便为临床减少钠潴留的发生提供策略。方法　我们依据三孔模型 ,建立了单次透析过程中钠转运的数学模型 ,描述了低钠透析液对钠清除量的影响。并在合理假设的基础上探讨了低钠透析液中合适的钠浓度。结果　钠浓度每降低 5mmol/L ,清除量增加 0 .2 3g。低钠透析液中合适的钠浓度可能 1 2 8mmol/L。结论　低钠透析液能够明显增加钠的清除。     

Novel TPM3 mutation in a family with cap myopathy and review of the literature

Cap myopathy is a rare congenital myopathy characterized by the presence of caps within muscle fibres and caused by mutations in ACTA1, TPM2 or TPM3. Thus far, only three cases with TPM3-related cap myopathy have been described. Here, we report on the first autosomal dominant family with cap myopathy in three-generations, caused by a novel heterozygous mutation in the alpha-tropomyosin-slow-encoding gene (TPM3; exon 4; c.445C>A; p.Leu149Ile). The three patients experienced first symptoms of muscle weakness in childhood and followed a slowly progressive course. They presented generalized hypotrophy and mild muscle weakness, elongated face, high arched palate, micrognathia, scoliosis and respiratory involvement. Intrafamilial variability of skeletal deformities, respiratory involvement and mild cardiac abnormalities was noted. Muscle MRI revealed a recognizable pattern of fatty muscle infiltration and masseter muscle hypertrophy. Subsarcolemmal caps were present in 6–10% of the fibres and immunoreactive with anti-tropomyosin antibodies. We conclude that the MRI-pattern of muscle involvement and the presence of masseter muscle hypertrophy in cap myopathy may guide molecular genetic diagnosis towards a mutation in TPM3. Regular respiratory examinations are important, even if patients have no anamnestic clues. We compare our findings to all cases of cap myopathy with identified mutations (n = 11), thus far reported in the literature.     

La psychiatrie de la personne âgée : enjeux et perspectives

Psychiatry in the elderly is a recent branch of psychiatry, born with the increased elderly population, and which tries to be an autonomous discipline in France. European and international Psychiatry in the elderly developed a corpus of knowledge, practices and institutional organizations of its own since 1950s. In France, its current organization is very recent and unequal between regions, so it needs to be clarified and developed. Its teaching has also to be delimited in order to give a better training for different levels of professionals, especially psychiatrists. We will discuss the current situation in France in the light of national and international data and will make hypothesis for development perspectives of its teaching.     

The effects of strength,aerobic, and concurrent exercise on skeletal muscle damage in rats

Introduction: In this study we examined oxidative stress and skeletal muscle damage resulting from acute strength, aerobic, or concurrent exercise in rats. Methods: The animals were divided into control (C), strength (SE), aerobic (AE), and combined (CE) exercise groups. They were euthanized at 3 different time‐points (6, 24, and 48 h) after acute exercise. Results: SE exercise rats had increased dichlorofluorescein oxidation at 6 h post‐exercise and decreased superoxide dismutase activity at all time‐points. Glutathione peroxidase activity and sulfhydryl levels were increased in the AE group at 48 h post‐exercise. Serum lactate dehydrogenase activity was increased in the SE and CE groups at 24 h and in the AE group at 48 h. Echo intensity was elevated at 24 h for all groups. Conclusions: Forty‐eight hours was sufficient for complete recovery from oxidative stress and muscle damage in the SE and CE groups, but not in the AE group. Muscle Nerve 50 : 79–86, 2014     

ROLE of exercise in maintaining the integrity of the neuromuscular junction

Physical activity plays an important role in preventing chronic disease in adults and the elderly. Exercise has beneficial effects on the nervous system, including at the neuromuscular junction (NMJ). Exercise causes hypertrophy of NMJs and improves recovery from peripheral nerve injuries, whereas decreased physical activity causes degenerative changes in NMJs. Recent studies have begun to elucidate molecular mechanisms underlying the beneficial effects of exercise. These mechanisms involve Bassoon, neuregulin‐1, peroxisome proliferator–activated receptor gamma coactivator 1α, insulin‐like growth factor‐1, glial cell line–derived neurotrophic factor, neurotrophin 4, Homer, and nuclear factor of activated T cells c1. For example, NMJ denervation and active zone decreases have been observed in aged NMJs, but these age‐dependent degenerative changes can be ameliorated by exercise. In this review we assess the effects of exercise on the maintenance and regeneration of NMJs and highlight recent insights into the molecular mechanisms underlying these exercise effects. Muscle Nerve 49 :315–324, 2014     

RYR1-related congenital myopathy with fatigable weakness,responding to pyridostigimine

The spectrum of RYR1 mutation associated disease encompasses congenital myopathies, exercise induced rhabdomyolysis, malignant hyperthermia susceptibility and King-Denborough syndrome. We report the clinical phenotype of two siblings who presented in infancy with hypotonia and striking fatigable ptosis. Their response to pyridostigimine was striking, but genetic screening for congenital myasthenic syndromes was negative, prompting further evaluation. Muscle MRI was abnormal with a selective pattern of involvement evocative of RYR1-related myopathy. This directed sequencing of the RYR1 gene, which revealed two heterozygous c.6721C>T (p.Arg2241X) nonsense mutations and novel c.8888T>C (p.Leu2963Pro) mutations in both siblings. These cases broaden the RYR1-related disease spectrum to include a myasthenic-like phenotype, including partial response to pyridostigimine. RYR1-related myopathy should be considered in the presence of fatigable weakness especially if muscle imaging demonstrates structural abnormalities. Single fibre electromyography can also be helpful in cases like this.     

The effects of prednisone and steroid-sparing agents on decay accelerating factor (CD55) expression: Implications in myasthenia gravis

Decay accelerating factor (DAF) expression at the muscle endplate is an important defence against complement-mediated damage in myasthenia gravis. Previously we implicated the c.-198C > G DAF polymorphism with the development of treatment-resistant myasthenia-associated ophthalmoplegia by showing that the C > G DAF polymorphism prevented lipopolysaccharide-induced upregulation of lymphoblast DAF. We postulated that drugs used in myasthenia gravis may increase the susceptibility of extraocular muscles to complement-mediated damage and studied their effects on endogenous DAF using patient-derived lymphoblasts as well as mouse myotubes. We show that prednisone repressed C > G DAF expression in lymphoblasts and increased their susceptibility to cytotoxicity. Methotrexate, but not azathioprine or cyclosporine, increased DAF in C > G lymphoblasts. In mouse myotubes expressing wild-type Daf, prednisone also repressed Daf expression. Although cyclosporine, azathioprine, and methotrexate increased muscle Daf levels when used alone, upon co-treatment with prednisone only azathioprine maintained myotube Daf levels close to basal. Therefore, prednisone negatively influences DAF expression in C > G lymphoblasts and in myotubes expressing wild-type Daf. We speculate that myasthenic individuals at risk of developing the ophthalmoplegic complication, such as those with C > G DAF, may have inadequate endogenous levels of complement regulatory protein protection in their extraocular muscle in response to prednisone, increasing their susceptibility to complement-mediated damage.     

Congenital absence of superficial posterior compartment calf muscles

Although various congenital abnormalities have been described, congenital absence of calf musculature is extremely rare, with only one report on its complete absence. We are the first to describe a case of congenital absence of muscles of the superficial posterior compartment of the calf presenting in a toddler. The child presented with a history of a painless limp, however no significant difference was found in functional gait analysis. We suggest that such cases should be monitored and parents can be reassured that no immediate treatment is required.