Mitochondrial myopathy with dystrophic features due to a novel mutation in the MTTM gene

Introduction: A 61‐year‐old woman with a 5‐year history of progressive muscle weakness and atrophy had a muscle biopsy characterized by a combination of dystrophic features (necrotic fibers and endomysial fibrosis) and mitochondrial alterations [ragged‐red, cytochrome c oxidase (COX)‐negative fibers]. Methods: Sequencing of the whole mtDNA, assessment of the mutation load in muscle and accessible nonmuscle tissues, and single fiber polymerase chain reaction. Results: Muscle mitochondrial DNA (mtDNA) sequencing revealed a novel heteroplasmic mutation (m.4403G>A) in the gene (MTTM) that encodes tRNA^Met. The mutation was not present in accessible nonmuscle tissues from the patient or 2 asymptomatic sisters. Conclusions: The clinical features and muscle morphology in this patient are very similar to those described in a previous patient with a different mutation, also in MTTM, which suggests that mutations in this gene confer a distinctive “dystrophic” quality. This may be a diagnostic clue in patients with isolated mitochondrial myopathy. Muscle Nerve 50:292–295, 2014     

采用SWOT法对高职医药营销专业就业形势的分析

据高职医药营销专业就业难的现状,采用SWOT分析法对该专业存在的优势、劣势、机会和威胁进行深入客观的分析.以便权衡利弊,帮助毕业生克服就业过程中的不足,协助学校审视自身存在的劣势,为高职医药营销专业就业形势改善提供参考.     

Postural instability in Charcot-Marie-Tooth 1A disease

The aim of this study was to evaluate the influence of somatosensory impairment, distal muscle weakness and foot deformities on the balance in 21 CMT1A patients using a baropodometric platform.Stabilometric analysis by measuring sway area and velocity of a centre of pressure (CoP) both at open and closed eyes were used to assess postural imbalance. Static analysis, by measuring the load and the plantar surface of forefoot, midfoot and hindfoot was used to define the footprint shape and to assess as a whole foot deformities. Stabilometric and static results were compared with those of a control group. In CMT1A patients, stabilometric findings were correlated with static parameters, Achilles’ tendon retraction, distal muscle strength and CMT examination score (CMTES). CMT1A patients compared to controls had lower plantar surface and load on midfoot, and higher load on a forefoot. CMT1A patients had a greater postural instability, since they had a higher CoP velocity, both at open and closed eyes. Moreover, the CoP velocity correlated inversely with the strength of ankle dorsi-flexion muscles and directly with CMTES as whole and with the item “motor symptoms legs”. Postural imbalance was not correlated with sensory impairment and foot deformities as expressed by static analysis and Achilles’ tendon retraction.In this study we demonstrated an altered balance in CMT1A patients during upright standing. The imbalance in our CMT patients seems to be related to the weakness of ankle dorsi-flexor muscles rather than sensory impairment or foot deformities. These results could be due to a mildly affected CMT1A population, evaluated in an early stage of the disease.     

胆汁反流性胃炎的病因病机探讨

胆汁反流性胃炎是开展纤维胃镜以来发现的疾病,深入研究其病因病机,对指导中医临床治疗用药,提高疗效具有重要意义。通过对胆汁反流性胃炎的病因病机进行中医理论的探讨,认为脾虚为致病之本,肝郁是致病之标,肝脾不和是病机的关键。     

多发性硬化的病因病机探讨

从邪毒外侵和正气内虚两方面认识多发性硬化的病因病机。邪毒主要考虑风邪外袭、湿热胶着、痰瘀互阻;正虚有肺气虚、脾气虚、脾阳虚、肝阴虚、肝血虚、肾精不足。     

Distal myasthenia gravis frequency and clinical course in a large prospective series

OBJECTIVES: In Myasthenia gravis (MG) proximal limb, ocular and/or bulbar muscles are most commonly affected, whereas distal extremity muscles are typically spared. The aim of the current study was to assess the frequency of primarily distal MG in the Tyrol and to describe its clinical peculiarities. MATERIAL AND METHODS: Over the past 20 years 84 patients with MG have undergone follow-up at the Department of Neurology of Innsbruck University. Types of presentation, clinical course and treatment response were followed over a period of 20 years (1980-2000). RESULTS: Six of 84 MG patients showed a predominance of muscle weakness and fatigability in distal limb muscles (two at presentation, four over the later course of the illness). There was no difference between distal MG and MG with a more typical distribution of muscle weakness regarding age, gender and response to therapy. CONCLUSIONS: The case series indicates that predominantly distal presentations of otherwise typical MG are more frequent than generally assumed and should be considered in the differential diagnosis of diseases with distal limb weakness.     

Spinal accessory neuropathy,droopy shoulder,and thoracic outlet syndrome

Droopy shoulder has been proposed as a cause of thoracic outlet syndrome. Two patients developed manifestations of neurovascular compression upon arm abduction, associated with unilateral droopy shoulder and trapezius muscle weakness caused by iatrogenic spinal accessory neuropathies following cervical lymph node biopsies. The first patient developed a cold, numb hand with complete axillary artery occlusion when his arm was abducted to 90 degrees. The second patient complained of paresthesias in digits 4 and 5 of the right hand, worsened by elevation of the arm, with nerve conduction findings of right lower trunk plexopathy (low ulnar and medial antebrachial cutaneous sensory nerve action potentials). Spinal accessory nerve grafting (in the first patient) coupled with shoulder strengthening physical exercises in both patients resulted in gradual improvement of symptoms in 2 years. These two cases demonstrate that unilateral droopy shoulder secondary to trapezius muscle weakness may cause compression of the thoracic outlet structures.     

Effect of prolonged mechanical ventilation on diaphragm muscle mitochondria in piglets

BACKGROUND: Respiratory muscle weakness is a common problem in the intensive care unit and could be involved in difficulties in weaning from the ventilator after prolonged mechanical ventilation. Animal models have shown that mechanical ventilation itself impairs diaphragm muscle function. In this study we investigated whether diaphragm contractile impairment caused by mechanical ventilation and immobilization in piglets is associated with a derangement in diaphragm mitochondria. METHODS: Seven piglets received controlled mechanical ventilation during 5 days. A control group of eight piglets were anaesthetized and surgically manipulated in the same way, but were mechanically ventilated for 4-6 h. After mechanical ventilation, diaphragm muscle biopsies were taken for measurements of mitochondria content, mitochondrial respiratory enzymes and markers of oxidative stress. RESULTS: Diaphragm mitochondrial content, as assessed by citrate synthase activities and volume density, was not different between the control and ventilated piglets. Activity of complex IV of the mitochondrial respiratory chain decreased by 21% (P=0.02) when expressed per muscle weight and by 11% (P=0.03) when expressed per citrate synthase activity. There were no changes in the markers of oxidative stress between the two groups. CONCLUSION: Five days of mechanical ventilation and immobilization decreased the activity of complex IV of the mitochondrial respiratory chain in the diaphragm muscle of the piglets.     

Electrophysiological signs of permanent axonal loss in a follow-up study of patients with Guillain-Barré syndrome

The neurophysiological mechanisms for persisting impairment of motor function after Guillain-Barre syndrome (GBS) were assessed in 37 unselected patients 1-13 years after diagnosis. For evaluation of reinnervation and axonal loss, macroelectromyography (macro-EMG) including measurement of fiber density (FD) was performed. Data from neuropathy symptom score, neuropathy disability score, nerve conduction studies, and quantitative sensory examination were ranked and summed to a neuropathy rank sum score (NRSS). The isokinetic muscle strength at the ankle was measured. Signs of axonal loss with increase of either macro motor unit potential (macro-MUP) amplitude or FD occurred in 76% of patients. The macro-MUP amplitude correlated with muscle strength and with NRSS. Patients with evidence of residual neuropathy had increased macro-MUP amplitude and FD as well as decreased muscle strength compared to patients without evidence of residual neuropathy. We conclude that axonal loss takes place in a substantial number of GBS patients and is associated with permanent muscle weakness caused by insufficient reinnervation. Possible patterns of pathology are discussed in relation to the macro-EMG findings.