Type IIx muscle fibers are related to poor body composition, glycemic and lipidemic blood profiles in young females: the protective role of type I and IIa muscle fibers.

PURPOSE: The aim of the present study was to investigate the association between muscle fiber composition, body composition, resting glycemic-lipidemic blood profiles, in apparently healthy, young, active females. METHODS: Thirty-four young healthy female volunteers were allocated into two groups, depending on their Vastus Lateralis type IIx muscle fibers percent cross-sectional area (%CSA; H: high type IIx %CSA; L: low type IIx %CSA). Body composition was determined via dual-energy X-ray absorptiometry. Venous blood samples were collected for the determination of resting serum glucose, Insulin, Apo-A1, HOMA-IR, triglycerides (TG), total cholesterol (TC), High-density lipoprotein (HDL-C), and Low-density lipoprotein (LDL-C) concentrations. Nutritional intake was also evaluated. RESULTS: Individuals of the H group have significantly higher body mass, body fat percentage-mass, and resting blood indices of glycemic and lipidemic profiles, compared to those of L group (p < 0.001). Increased type IIx and low type I, IIa muscle fibers %CSAs were linked with poorer body composition, glycemic and lipidemic blood profiles (r: - 0.722 to 0.740, p < 0.001). Linear regression analyses revealed that the impact of muscle fibers %CSA (B coefficients ranged between - 0.700 and 0.835) on the above parameters, was at least, of the same or even of greater magnitude as that of body composition and daily nutritional intake (B: - 0.700 to 0.666). CONCLUSION: Increased type IIx and low Type I, IIa %CSAs are associated with poorer body composition and glycemic-lipidemic profiles in young healthy females. The contribution of the muscle fiber %CSA on health status seems to be comparable to that of nutrition and body composition.

Aldolase A deficiency: Report of new cases and literature review.

Aldolase A (ALDOA), is the predominant isoform of aldolase in skeletal muscle and erythrocytes that catalyzes the reversibleconversion of fructose-1,6-bisphosphate to glyceraldehyde 3-phosphate. Autosomal recessive mutations in ALDOA, are extremely rare and cause hemolytic anemia and/or recurrent episodes of rhabdomyolysis, usually precipitated by fever. In this report we describe, clinical, laboratory and genetic data of two novel unrelated patients harboring mutations in the ALDOA gene who presented with episodic rhabdomyolysis, we review all previously published cases and discuss the most valuable features for diagnosis of this rare disorder.

Early onset posterior subscapular cataract in a series of myotonic dystrophy type 2 patients.

PurposeEarly onset posterior subscapular cataract (<50 years of age) is a characteristic feature of myotonic dystrophy type 2 (DM2). Nevertheless, despite being operated at a young age, many patients remain undiagnosed for years. The purpose of this study was to assess the prevalence of early onset posterior subscapular cataract as a presenting symptom of the disease in a cohort of patients with DM2.Patients and methodsWe retrospectively reviewed medical records of DM2 patients followed in our institution for the presence of early onset posterior subscapular cataract, of any secondary causes of cataract, of the age of onset of muscle weakness and of final disease diagnosis.ResultsTwenty-eight patients were studied. Nine patients (32.1%) had presented early onset posterior subscapular cataract at a median age of 43 years (IQR=36-46) and seven (25%) reported it was the presenting sign. No patient was referred for neuromuscular evaluation due to the occurrence of early onset cataract. Median delay between cataract onset and referral for neuromuscular evaluation was 10 years (IQR=6.0-19.5) and final DM2 diagnosis was achieved after a median of 16 years (IQR=6.5-19.5).ConclusionThis study shows that early onset posterior subscapular cataract was the first symptom of the disease in 25% of our DM2 patients. Nevertheless, none was suspected of having cataract in the context of DM2, and referral for neuromuscular evaluation was made after a long delay and usually following the appearance of other symptoms. Ophthalmologists can be the first physicians encountering these patients and should have a low threshold for referring them for neuromuscular evaluation.

Effects of high-intensity interval cycling performed after resistance training on muscle strength and hypertrophy.

Aim of the study was to investigate whether high-intensity interval cycling performed immediately after resistance training would inhibit muscle strength increase and hypertrophy expected from resistance training per se. Twenty-two young men were assigned into either resistance training (RE; N = 11) or resistance training plus high-intensity interval cycling (REC; N = 11). Lower body muscle strength and rate of force development (RFD), quadriceps cross-sectional area (CSA) and vastus lateralis muscle architecture, muscle fiber type composition and capillarization, and estimated aerobic capacity were evaluated before and after 8 weeks of training (2 times per week). Muscle strength and quadriceps CSA were significantly and similarly increased after both interventions. Fiber CSA increased significantly and similarly after both RE (type I: 13.6 ± 3.7%, type IIA: 17.6 ± 4.4%, type IIX: 23.2 ± 5.7%, P < 0.05) and REC (type I: 10.0 ± 2.7%, type IIA: 14.8 ± 4.3% type IIX: 20.8 ± 6.0%, P < 0.05). In contrast, RFD decreased and fascicle angle increased (P < 0.05) only after REC. Capillary density and estimated aerobic capacity increased (P < 0.05) only after REC. These results suggest that high-intensity interval cycling performed after heavy-resistance exercise may not inhibit resistance exercise-induced muscle strength/hypertrophy after 2 months of training, while it prompts aerobic capacity and muscle capillarization. The addition of high-intensity cycling after heavy-resistance exercise may decrease RFD partly due to muscle architectural changes.

GNE-Myopathy in a Greek Romani Family with Unusual Calf Phenotype and Protein Aggregation Pathology.

BACKGROUND: GNE-myopathy is increasingly diagnosed in different ethnicities worldwide. No clear genotype-phenotype correlation has been established to date. CASE REPORTS: We describe two affected members of the same family from Balkan population carrying an already known homozygous pathogenic mutation in the kinase domain of the UDP-N-acetylglucosamine 2 epimerase/N-acetylmannosamime kinase (GNE) gene. The patients presented with severe distal weakness of lower legs combined with rimmed vacuoles in muscle biopsy. However, in contrast to the typical pattern of muscle involvement, one of them showed severe involvement of posterior calf muscles with spared anterior compartment of the lower leg muscles. CONCLUSIONS: These patients provide evidence for a larger variability and further extend the phenotypic spectrum of GNE-myopathy to include preferential calf involvement.

Electrodiagnosis and muscle biopsy in asymptomatic hyperckemia.

Purpose/aim of the study: An increased serum level of creatine kinase (CK) in asymptomatic individuals is a diagnostic challenge, as it may be associated with either physiological conditions, such as exercise or even signal an ominous neuromuscular disease at a presymptomatic stage. The electromyogram (EMG) and the muscle biopsy play a key role in the evaluation of asymptomatic hyperckemia. The objective of this study was to investigate asymptomatic individuals with increased CK levels. MATERIALS AND METHODS: We comparatively studied EMG, quantitative EMG and muscle biopsy in asymptomatic clinically normal individuals with repeatedly increased CK levels. RESULTS: Conventional EMG was abnormal in 76% of patients, while quantitative EMG showed abnormal results in 88.9%. Muscle biopsy was diagnostic in 28%, one patient had neurogenic findings, 40% showed non-specific changes and 28% had normal results. CONCLUSIONS: EMG and especially quantitative EMG are highly sensitive in detecting subclinical neuromuscular diseases, whereas muscle biopsy may better contribute in the final diagnosis. No strong correlations were found between histological abnormalities and electrophysiological data, but further research is needed.

Extraocular muscle function in adult-onset Pompe disease tested by saccadic eye movements.

Glycogen storage disease type II (Pompe disease) affects mainly proximal skeletal muscles. Despite older histological evidence of extraocular muscle involvement, ocular motor palsies or other eye movement abnormalities are not considered part of the clinical picture. We investigated the dynamics of saccadic eye movements of five patients suffering from late-onset Pompe disease and compared their performance to that of age matched healthy controls. Horizontal rightward and leftward saccades were recorded binocularly, while subjects looked at LED targets placed at ±5°, 10° and 15° eccentricities. No differences in saccade amplitudes, peak velocities or durations were observed between controls and patients. More specifically, for 5° saccades, patients had a mean peak velocity of 146°/s with duration of 76ms. For 10° and 15° saccades these values were 258°/s, 86ms and 324°/s, 101ms respectively, thereby lying well within one standard deviation of the mean of normal data. Moreover, saccadic amplitude accuracy was also unimpaired. These results indicate that patients with late onset Pompe disease perform fast and accurate horizontal saccades without evidence of muscle paresis or other ocular motor abnormalities. Reported histological abnormalities of extraocular muscles do not appear to have a phenotypic impact.

Highlighting intrafamilial clinical heterogeneity in late-onset Pompe disease.

BACKGROUND/AIMS: Pompe disease is a rare metabolic disorder caused by deficiency of the lysosomal enzyme acid alpha-glycosidase (GAA). The late onset form of the disease is characterized by muscle weakness and respiratory involvement of variable severity. The aim of this short communication is to highlight the clinical variability of Pompe disease within siblings suffering from the disease. CASE REPORTS: We report three pairs of siblings with late-onset Pompe disease presenting with different clinical phenotypes within the spectrum of disease phenotypes. CONCLUSION: Clinical manifestations in Pompe disease within the same family can be very different. Clinicians should investigate patients' siblings for symptoms throughout the entire spectrum of the disease in order to avoid delays in the diagnosis and to pick-up mildly affected persons as early as possible, when they can benefit the most from enzyme replacement therapy.

Late onset glycogen storage disease type II: pitfalls in the diagnosis.

BACKGROUND/AIMS: Glycogen storage disease type II (GSD-II) is a lysosomal disorder caused by acid α glucosidase (GAA) deficiency. The infantile form is easier to recognize compared with the milder adult form that may manifest as myopathy without specific clinical characteristics. The aim of this study is to highlight frequent diagnostic errors in adult GSD-II patients. CASE REPORTS: We report four patients with confirmed GSD-II who were at first diagnosed with hypothyroid myopathy, connective tissue disorder, an underlying liver disease and muscular dystrophy, respectively. CONCLUSION: Internists but even neurologists with low suspicion may misdiagnose GSD-II. The early respiratory involvement and the characteristic laboratory abnormalities in a myopathic patient should include GAA deficiency in the differential diagnosis especially in the era of enzyme replacement therapy.

Adult Pompe disease: clinical manifestations and outcome of the first Greek patients receiving enzyme replacement therapy.

OBJECTIVE: Pompe disease is an autosomal recessive lysosomal disorder caused by α-glucosidase deficiency. A specific treatment for the disease with enzyme replacement therapy is currently available. The aim of the present study is to describe the clinical manifestations and the effect of treatment in the first Greek patients with the adult form of the disease. METHODS: Five Greek patients with adult onset Pompe disease aged between 40 and 73 years received 20 mg/kg Myozyme intravenously at two weekly intervals over a different period. Clinical and functional parameters were longitudinally registered. RESULTS: Proximal muscle weakness and respiratory insufficiency were the most common manifestations of the disease, but their severity was different even among patients with similar genotype. The effect of treatment varied with most patients experiencing some improvement in muscle strength and fatigability, while the most severely affected patient did not benefit and stopped therapy. CONCLUSION: No clear genotype-phenotype correlation emerges from our study. The different effect of treatment on our patients seems to be mainly related to their pre-treatment condition and can be reliably assessed only on a long term basis.

Body composition analysis in late-onset Pompe disease.

Pompe disease is an inherited metabolic disorder caused by α-glycosidase deficiency. The adult onset form is mainly characterized by progressive proximal muscle weakness and respiratory dysfunction. The aim of the present study is to evaluate body composition in adult patients before and after enzyme replacement therapy (ERT). Body composition was examined at baseline by means of dual x-ray absorptiometry (DXA) in nine adult patients and after different time periods in six of them who received ERT. Total BMD (bone mineral density) was initially mildly decreased in two patients, while femoral neck BMD was decreased in five patients. On the other hand fat mass was increased in the majority of patients, while body mass index (BMI) was high in four. ERT administration did not seem to induce obvious BMD changes in any patient. Conclusively, the greater femoral neck BMD involvement may be attributed to the lower mechanical load applied by the selectively weakened muscles, whereas the increased fat mass may be the result of metabolic and nutritional derangement.

Superficial siderosis of central nervous system mimicking multiple sclerosis.

INTRODUCTION: Superficial siderosis of the central nervous system is a neurologic disorder mainly characterized by cerebellar involvement, myelopathy, neurosensory hearing loss, and possibly progressive cognitive impairment. Root avulsion due to traumatic plexus injury has been recognized as an extremely rare cause of hemosiderin deposition on leptomeninges and subpial layers of brain and spinal cord parenchyma. CASE REPORT: A 49-year-old man presented with progressively evolving ataxia and spastic paraparesis. CSF oligoclonal bands were indicative of an underlying inflammatory process and raised the possibility of a demyelinating disorder. However, spinal cord and brain MRI revealed hemosiderin deposition along the entire neuraxis. A rigorous electrophysiologic study confirmed a functional impairment in many different levels of the nervous system. CONCLUSION: The demonstration of CSF oligoclonal bands in the reported patient implies that inflammation might be involved in the pathogenesis of superficial siderosis. The diagnosis of this newly recognizable entity needs a high clinical suspicion, but further research is needed to fully elucidate the involved mechanisms.

Platelet-activating factor (PAF) involvement in acetaminophen-induced liver toxicity and regeneration.

Acetaminophen-induced toxicity has been attributed to cytochrome P-450-generated metabolites, which covalently modify target proteins. However, the mechanism of liver injury pathogenesis needs to be further elucidated. Platelet-activating factor (PAF) is one of the mediators involved in inflammatory tissue alterations associated with acute liver failure. In this study, alterations in blood PAF levels and the serum activity of PAF-acetylhydrolase (PAF-AH) were investigated over the time course of liver injury and regeneration induced by acetaminophen treatment in rats. The administration of a toxic dose of acetaminophen (3.5 g/kg) in rats caused acute hepatic injury, as evident by alterations of biochemical (serum enzymes: ALT, AST and ALP) and liver histopathological (degree of inflammation and apoptosis) indices between 20 and 40 h post-treatment. The hepatic damage was followed by liver regeneration, made evident by three independent indices ([3H]thymidine incorporation into hepatic DNA, liver thymidine kinase activity and hepatocyte mitotic index), presenting a peak at 72 h. The PAF levels were elevated at 24 and 28 h, presenting a remarkable peak at 32 h post-treatment. PAF-AH activity presented different kinetics to that of PAF. The enzyme activity was relatively low at all time points examined before the rise in PAF activity, peaking later, at 72, 84 and 96 h. Our data demonstrate that PAF is involved in the pathogenesis of acute liver failure and in augmented compensatory liver tissue repair post-acetaminophen treatment. However, the putative role of PAF during liver toxicity and regeneration remains to be established.