Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a 21-year-old man with distal dominant progressive muscle atrophy. The patient was apparently well until 17 years of age when he noted a decrease in exercise tolerance. One year later, he noted difficulty in arising his heels when the walked. He was admitted to our service for the work up in June 10, 1992. On admission, the patient was rather slender in the body build up; otherwise general physical examination was unremarkable. Upon neurologic examination, mental status and higher cerebral functions were normal. In the cranial nerves, the sternocleidomastoid muscles were atrophic bilaterally; other cranial nerves appeared intact. His gait was unstable and he showed steppage gait; walking on toes and heels were impossible. Distal dominant muscle atrophy was noted in both upper and lower extremities. Muscle strength in the deltoid, biceps brachii and triceps brachii was normal. In the lower extremities, both tibialis anterior and triceps surae muscles were weak (3/5). The iliopsoas and quadriceps femoris muscles were normal, however, the adductor muscles of the thigh showed marked weakness (2/5). Myotonia was absent. Deep reflexes were decreased; sensation was intact. Routine blood tests were unremarkable; CK was 96 IU/l, lactate 6.9 mg/dl, and pyruvate 0.61 mg/dl. After an ischemic forearm exercise test, blood lactate level rose to 22.5mg/dl (base line 11.2), and blood ammonia to 88.3 micrograms/dl (base line 71.2). EMG showed myogenic changes and myotonic discharges. A diagnostic biopsy was performed. The patient was discussed in a neurologic CPC, and the chief discussant arrived at the conclusion that the patient had type III glycogen storage disease. The differential diagnosis included rimmed vacuole type myopathy, Miyoshi type distal muscular dystrophy, Welander type muscular dystrophy, adult type acid-maltase deficiency, and lysosomal glycogen storage disease with normal acid maltase. However, characteristic clinical presentation of initial weakness in the triceps surae muscle associated with atrophy of the sternocleidomastoid muscle confirmed best of the clinical characteristics of type III glycogen storage disease; the only finding which did not fit with its diagnosis was elevation of the blood lactate level after the ischemic exercise test. The muscle biopsy specimen showed marked vacuole formation; approximately 20 to 30% of the vacuoles were rimmed vacuoles, however, the majority was not rimmed. PAS staining on an epon-embedded specimen revealed marked accumulation of PAS-positive materials in those vacuoles as well as in the interfascular space. The non-rimmed vacuoles were not positively stained in the acid-phosphatase staining, which exclude the diagnosis of acid maltase deficiency. No mitochondrial abnormalities were found.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[A 21-year-old man with distal dominant progressive muscle atrophy]. 778 29

Malnutrition is a serious threat to patients with neuromuscular disease and marginally-compensated respiratory muscle weakness. It causes atrophy of inspiratory muscles, further weakening them. It reduces respiratory drive, potentially aggravating respiratory failure, either directly or indirectly, by promoting atelectasis and pneumonia, and it contributes strongly to such patients' risk of infection, their most common cause of death. In treating such patients, it must be remembered that abrupt increases in nutritional support, particularly with high percentages of carbohydrates, will increase CO2 production, potentially worsening ventilatory failure. Certain selected neuromuscular disease patients benefit from specific nutritional treatments (carnitine for carnitine deficient patients, high-calorie diets for muscular dystrophy and acid-maltase deficiency). Finally, the amino acid, fat, and nucleic acid content of the diet affects the immune response in beneficial or harmful ways, that are just now being elucidate. The potential for useful nutritional interventions in patients with neuromuscular diseases has never looked better, but is not yet fully realized. The challenges for the future will be to work out the beneficial and harmful effects of the various nutrients in the various diseases, to find ways to rapidly identify patients who will benefit, and to determine the safest, least uncomfortable, and most effective methods of delivery of the required nutrients.
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PMID:Nutritional factors in the pathogenesis and therapy of respiratory insufficiency in neuromuscular diseases. 825 75

Clinical, diagnostic and biochemical features of generalised glycogenosis are described in 96 Brahman-type calves. Typically the calves were presented when about 6 months of age, with ill-thrift and muscular weakness as the most common signs. Acidic alpha-glucosidase activity was reduced in peripheral blood lymphocytes and skeletal muscle. Muscle glycogen concentration was consistently higher in affected animals than in clinically normal cattle. Other observations in affected calves included elevation of serum aspartate aminotransferase and creatine kinase activities and excessive amounts of high molecular weight oligosaccharides in urine. Fine cytoplasmic vacuolation of neurones in the brain and spinal cord, skeletal muscle, myocardium and of Purkinje fibres were consistent histological observations. Periodic acid-Schiff staining revealed the presence of glycogen-like material in peripheral blood lymphocytes of all affected calves, indicating that this is a useful aid for the diagnosis of glycogenosis. While 3 of the 96 calves showed somewhat different clinical signs, the similarity of pathology and the biochemical and clinical evidence in the remainder suggested that, in these animals, the disease was expressed as a single syndrome.
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PMID:Clinical, diagnostic and biochemical features of generalised glycogenosis type II in Brahman cattle. 828 22

A 46-year-old white female was admitted for decompensated cor pulmonale (CP). It had not interfered with her daily activities and she had not experienced shortness of breath, fatigue or muscle weakness prior to the onset of right heart failure. A thorough investigation revealed severe generalized muscle weakness with restrictive chest bellows disease and secondary CP (mean pressure in the pulmonary artery 60 mm Hg). After having refused respiratory support the patient died a few days after admission. The muscle biopsy was consistent with adult-onset acid-maltase deficiency. This is a rare case of metabolic myopathy presenting as decompensated CP without previous symptoms of muscle weakness. This condition can easily be treated with nocturnal ventilatory support, improving the quality and length of life.
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PMID:Decompensated cor pulmonaleas the first manifestation of adult-onset myopathy. 973 Aug 2

Dumping syndrome commonly occurs after gastrectomy. The late dumping, which is one of the dumping syndromes, is due to postprandial hypoglycaemia caused by an excessive insulin secretion after a sharp rise in plasma glucose. Several treatments, including operation, dietary fibre and somatostatin, have been attempted to relieve dumping symptoms. These treatments take effect through modulation of plasma insulin and glucose levels, but their efficacy is still under consideration. Alpha-glucosidase inhibitor attenuates the postprandial increase of plasma glucose levels and is widely used for treatment of non-insulin-dependent diabetes mellitus (NIDDM). The acute effect of alpha-glucosidase inhibitor on late dumping syndrome has been reported by some studies with test meals. The purpose of this study was to evaluate a long-term effect of alpha-glucosidase inhibitor treatment with ordinary meals in late dumping patients with NIDDM because administration of alpha-glucosidase inhibitor is only ethically allowed for diabetic patients in Japan. Six late dumping patients with NIDDM were orally administered alpha-glucosidase inhibitor, acarbose (50 or 100 mg), three times a day before each meal for 1 month. Diurnal changes of plasma glucose, insulin and pancreatic glucagon levels were compared before and after the alpha-glucosidase inhibitor treatment. All patients had late dumping-related symptoms, such as weakness, palpitation and dizziness before the induction of alpha-glucosidase inhibitor treatment. Patients suffered from a rapid fall in plasma glucose levels from hyperglycaemia at the same time as dumping symptoms. These late dumping-related symptoms disappeared and a rapid change of plasma glucose and insulin levels were attenuated after the alpha-glucosidase inhibitor treatment. These data suggest a long-term therapeutic efficacy of alpha-glucosidase inhibitor for late dumping patients.
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PMID:Long-term effect of alpha-glucosidase inhibitor on late dumping syndrome. 991 26

The importance of proper lysosomal activity in cell and tissue homeostasis is underlined by "experiments of nature", i.e. genetic defects in one of the at least 40 lysosomal enzymes/proteins present in the human cell. The complete lack of 1-4 alpha-glucosidase (glycogen storage disease type II (GSD II) or Pompe disease) is life-threatening. Patients suffering from GSD II commonly die before the age of 2 years because of cardiorespiratory insufficiency. Striated muscle cells appear to be particularly vulnerable in GSD II. The high cytoplasmic glycogen content in muscle cells most likely gives rise to a high rate of glycogen engulfment by the lysosomes. The polysaccharides become subsequently trapped in these organelles when 1-4 alpha-glucosidase activity is absent. During the course of the disease, muscle wasting occurs. It is hypothesised that the gradual loss of muscle mass is caused by a combination of disuse atrophy and lipofuscine-mediated apoptosis of myocytes. Moreover, we hypothesise that in the remaining skeletal muscle cells, longitudinal transmission of force is hampered by swollen lysosomes, clustering of non-contractile material and focal regions with degraded contractile proteins, which results in muscle weakness.
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PMID:Lysosomal dysfunction in muscle with special reference to glycogen storage disease type II. 1263 5

Pompe's disease is an autosomal recessive myopathy. The characteristic lysosomal storage of glycogen is caused by acid alpha-glucosidase deficiency. Patients with late-onset Pompe's disease present with progressive muscle weakness also affecting pulmonary function. In search of a treatment, we investigated the feasibility of enzyme replacement therapy with recombinant human alpha-glucosidase from rabbit milk. Three patients (aged 11, 16, and 32 years) were enrolled in the study. They were all wheelchair-bound and two of them were ventilator dependent with a history of deteriorating pulmonary function. After 3 years of treatment with weekly infusions of alpha-glucosidase, the patients had stabilized pulmonary function and reported less fatigue. The youngest and least affected patient showed an impressive improvement of skeletal muscle strength and function. After 72 weeks of treatment, he could walk without support and finally abandoned his wheelchair. Our findings demonstrate that recombinant human alpha-glucosidase from rabbit milk has a therapeutic effect in late-onset Pompe's disease. There is good reason to continue the development of enzyme replacement therapy for Pompe's disease and to explore further the production of human therapeutic proteins in the milk of mammals.
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PMID:Enzyme replacement therapy in late-onset Pompe's disease: a three-year follow-up. 1504 88

A six-year-old child presented at 8 months of age with proximal muscle weakness and mild cardiac hypertrophy. Some alpha-glucosidase activity was detected in muscle but not in fibroblasts. As none of the two pathogenic mutations, [c.1933G>A]+[c.2702T>A] (Asp645Asn/Leu901Gln), led to detectable alpha-glucosidase activity upon expression in COS cells, the phenotype of the patient remained unexplained. A functionally comparable set of mutations, Asp645Asn/insGnt2243, was reported previously to cause classic infantile Pompe disease [Biochem Biophys Res Commun 244 (1998) 921]. We conclude that secondary genetic or environmental factors can be decisive for the phenotypic outcome of classic infantile versus childhood Pompe disease, when the acid alpha-glucosidase activity is extremely low.
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PMID:A case of childhood Pompe disease demonstrating phenotypic variability of p.Asp645Asn. 1514 38

Pompe's disease is a neuromuscular disorder caused by deficiency of lysosomal acid alpha-glucosidase. Recombinant human alpha- glucosidase is under evaluation as therapeutic drug. In light of this development we studied the natural course of cases not fitting the definition of classic infantile Pompe's disease. Our review of 109 reports including 225 cases shows a continuous spectrum of phenotypes. The onset of symptoms ranged from 0 to 71 years. Based on the available literature, no criteria to delineate clinical sub-types could be established.A common denominator of these cases is that first symptoms were related to or caused by muscle weakness. In general, patients with a later onset of symptoms seemed to have a better prognosis. Respiratory failure was the most frequent cause of death. CK, LDH, ASAT, ALAT and muscle glycogen levels were frequently but not always elevated. In most cases a muscle biopsy revealed lysosomal pathology, but normal muscle morphology does not exclude Pompe's disease. In 10% of the cases in which the enzyme assay on leukocytes was used, a normal alpha-glucosidase activity was reported. Data on skeletal muscle strength and function, pulmonary function, disability, handicap and quality of life were insufficiently reported in the literature. Studies of non-classic Pompe's disease should focus on these aspects, before enzyme replacement therapy becomes generally available.
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PMID:The natural course of non-classic Pompe's disease; a review of 225 published cases. 2161 30

Pompe disease, or glycogen storage disease type II, is a rare autosomal recessive disorder caused by mutations in the gene that encodes for alpha-glucosidase. Presentation in infancy is associated with respiratory failure, cardiomyopathy, and severe muscle weakness. Juvenile- or adult-onset cases typically present with proximal muscle weakness and are associated with respiratory insufficiency or exertional dyspnea. Treatment, until recently, was focused on supportive measures, and infants diagnosed with Pompe disease usually died within the first year of life. The recent development of recombinant alpha-glucosidase has dramatically improved the life expectancy and quality of life of infantile-onset disease with improvements in respiratory and motor function observed in juvenile- or adult-onset cases. This review focuses on the presentation, pathogenesis, diagnosis, and treatment recommendations for Pompe disease in this new era of enzyme replacement therapy.
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PMID:Pompe disease: a review of the current diagnosis and treatment recommendations in the era of enzyme replacement therapy. 1852 27


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