Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The present paper describes an animal model of lysosomal glycogenosis as induced by a competitive inhibitor of alpha-glucosidase. Rats received intraperitoneal injections of the inhibitor, a pseudotetrasaccharide (Acarbose, Bay g 5421); liver tissue was examined by light and electron microscopy. Substrate-histochemical and enzyme-cytochemical methods were used to demonstrate intralysosomal glycogen storage within hepatocytes and Kupffer cells. The cytological picture closely resembled that occurring in glycogenosis type II (Pompe's disease) of humans. After cessation of drug treatment, the glycogen storage was slowly reversible. The present results point to the physiological role of the lysosomal apparatus for intracellular glycogen turnover. On the cellular level, this experimentally induced glycogenosis may be useful as a model of Pompe's disease.
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PMID:Lysosomal glycogen storage mimicking the cytological picture of Pompe's disease as induced in rats by injection of an alpha-glucosidase inhibitor. I. Alterations in liver. 611 39

Glycogen storage diseases of type I, II, III, IV, V and the other muscle types, were examined electron microscopically, biochemically and physicochemically. Glycogenosomes (glycogen containing vacuoles) were found in the affected tissues of type II, type III variant of muscle glycogen storage disease, type IV and muscle type phosphorylase b kinase deficiency (disorder of the phosphorylase b kinase activation mechanism). The acid alpha-glucosidase activity was decreased only in the case of type II glycogen storage disease (Pompe's disease). The other types of glycogen storage disease showed no decrease in acid alpha-glucosidase activity. Moreover, one patient with type II disease also revealed a decrease in neutral alpha-glucosidase activity. In all cases where glycogenosomes were found, the extracted glycogen macromolecules showed some molecular abnormality or deviation when compared with normal native glycogen macromolecules.
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PMID:Glycogen storage disease. Studies related to the mechanism of glycogenosome formation. 630 67

An infant with hypotonia, gross cardiomegaly and heart failure is described. Angiocardiography revealed a hypertrophic restrictive cardiomyopathy. The diagnosis of type II glycogenosis was confirmed by the total absence of alpha-1,4-glucosidase in cultured skin fibroblasts. It is now possible to offer prenatal diagnosis by amniocentesis to women at risk of having affected children.
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PMID:Angiocardiographic and enzyme studies in a patient with type II glycogenosis (Pompe's disease). A case report. 677 81

We analyzed clinical, histological and biochemical findings in 10 patients with glycogen storage disease in skeletal muscle. Four patients were deficient in acid-alpha-glucosidase (Glycogenosis type II), three of them with late infantile onset and one patient adult form. Five patients, two of them siblings, were deficient in myophosphorylase (glycogenosis type V, McArdle's disease). One patient was a newborn with phosphofructokinase deficiency (glycogenosis type VII, Tarui's disease). Of the study of our cases we would like to outline the following features: in the glycogenosis type II the deposit is fundamentally intralysosomal in the late infantile form, storage of mucopolysaccharides and deposit in interstitial fibroblasts were found, while in the adult form glycogen storage is minimal. In the glycogenosis type V the storage of glycogen is free and of a small amount. In two patients we have observed enzymatic activity in regenerating fibres. In glycogenosis type VII the storage is free, of considerable quantity and the interstitial cells are also affected; no storage is observed in the satellite cells.
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PMID:Glycogen storage disease in skeletal muscle. Morphological, ultrastructural and biochemical aspects in 10 cases. 693 56

Type II glycogenosis is an autosomal recessive storage disease characterized by absence of the enzyme acid alpha-1,4-glucosidase. The eye of a 16 week fetus, aborted after diagnosis by amniocentesis, was studied by light and electron microscopy. Extensive deposits of lysosomal and cytoplasmic glycogen were present in virtually all ocular tissues examined, with the notable exception of pigment epithelia (iris and retina). The massive glycogen deposits present in this, the youngest case thus far examined histologically, emphasize the involvement of the fetus from its earliest stages and the importance of prenatal diagnosis.
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PMID:Ultrastructure of the eye in fetal type II glycogenosis (Pompe's disease). 694 96

Soluble polymers of rat (or human) albumin and alpha-1,4-glucosidase are prepared using the cross-linking agent glutaraldehyde. The resulting polymer has an average molecular weight of 800 000 indicating an average composition of 12 albumin molecules for each enzyme molecule. Compared with an equivalent amount of free enzyme, the enzyme-albumin polymer has an increased resistance to heat denaturation (half-life of 15 h compared with 1 h for free enzyme at 37 degrees C) and to proteolysis by trypsin (half-life of 180 min compared with 10 min). The high degree of resistance to bioinactivation of the enzyme-albumin polymer is discussed in relation to requirements for enzyme replacement therapy in a range of metabolic diseases including type II glycogenosis (Pompe's disease) where alpha-1,4-glucosidase is the defective enzyme.
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PMID:alpha1,4-Glucosidase-albumin polymers: in vitro properties and advantages for enzyme replacement therapy. 699 Oct 81

The results of immunochemical studies performed in 6 cases of type II glycogenosis (1 classical form, Pompe's disease) and 5 atypical forms (2 juvenile, 3 adult) are reported. The use of antiacid alpha-1,4-glucosidase antibodies greatly improved the specificity of the diagnostic tests for type II glycogenosis, particularly in fibroblasts, lymphocytes, and urine. The use of these antibodies permits the precise measurement of lysosomal enzymes and also enables to demonstrate the activating influence of potassium chloride on urinary lysosomal alpha-1,4-glucosidase. The use of such specific antibodies should prove to be an aid in genetic studies and allows a better understanding of the disease mechanism.
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PMID:Immunochemical studies of human acid alpha-1,4-glucosidase in type II glycogenosis. 701 96

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

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

Northern analyses revealed normal levels of acidic alpha-glucosidase mRNA in cultured fibroblasts from a Shorthorn calf affected with glycogenosis but a gross deficiency in an affected Brahman calf. Analyses of acidic alpha-glucosidase activity, relative to that of other lysosomal enzymes, in blood mononuclear cells revealed greater variation within and between Brahman herds than Shorthorn herds. A Msp1 restriction fragment length polymorphism associated with glycogenosis in Brahmans was not found in Shorthorns. These results are considered in relation to molecular heterogeneity for AAG deficiency in cattle and its implications for disease control programs.
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PMID:Evidence of molecular heterogeneity for generalised glycogenosis between and within breeds of cattle. 857 63


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