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:3.1.3.9 (glucose-6-phosphatase)
3,081 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A four-month-old boy affected by glycogen storage disease type I is presented. The child suffered from hepatomegaly, lactic acidosis, fasting hypoglycemia and failure to thrive. He had repeated infectious and cyclic neutropenia. Immunoglobulin and chemotactic neutrophil motility was impaired. Liver biopsy showed increased amounts of glycogen in hepatic cells as assessed by morphological and biochemical grounds. The activity of glucose-6-phosphatase as well as other glycogenolytic enzymes was normal in the frozen liver. The aforementioned characteristics suggested the diagnosis of glycogen storage disease type Ib. The child was first treated by enteral continuous feeding and later on by frequent meals during the daytime and enteral continuous feeding during the night time, improving the hypoglycemia as well as the other biochemical and metabolic abnormalities.
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PMID:[Present-day status of glycogenosis Ib. Report of a new case]. 319 58

Carbohydrates with digestion characteristics between those of lente uncooked starches and rapidly digestible oligosaccharides were administered in a dose of 1.5 g/kg body weight to five patients with glycogenosis from glucose-6-phosphatase deficiency. Postprandial duration of normoglycemia and concentrations of blood insulin and lactate were determined. Uncooked barley groats in water, or incorporated in a meal turned out to behave as lente carbohydrates. Uncooked couscous in water, couscous incorporated in a meal, and partially cooked macaroni given as a meal behaved as semilente carbohydrates as compared with uncooked cornstarch and glucose. The in vitro determination of the digestibility index along with the in vivo tolerance test enables us to choose and incorporate semilente carbohydrates in the day-time treatment of patients.
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PMID:Complex carbohydrates in the dietary management of patients with glycogenosis caused by glucose-6-phosphatase deficiency. 329

Polymorphonuclear leukocyte (PMN) function was investigated in two patients with glycogen storage disease type IB and neutropenia. Glycogen storage disease type IB was documented by liver biopsy and a normal amount of latent glucose-6-phosphatase activity. Patient A had stomatitis, skin infections, and septicemia; patient B had respiratory infections, periodontitis, and oral candidiasis. Absolute neutrophil counts ranged from 114 to 2580/mm3. Diminished and delayed migration of PMN into a skin "window" occurred in B. Random and directed PMN migration under agarose toward f-Met-Leu-Phe, pepstatin A, and zymosan-activated serum were severely diminished in both patients. At 10(-7) M f-Met-Leu-Phe, mean random and directed migration were 52 and 23% (A, n = 3) and 48 and 13% (B, n = 4) of controls. These results were independent of incubation time and chemoattractant concentration. Patients' PMN had diminished quantitative nitroblue tetrazolium reduction compared to controls. B had a significant defect in PMN bactericidal activity with Escherichia coli with less than 0.2 log killing at 2 h. These results further characterize the defect in PMN migration reported by Beaudet et al. (J Pediatr 97:906, 1980). The finding of other abnormalities of PMN function suggests a metabolic defect in the neutrophil which may be related to the microsomal membrane defect in hepatocytes in glycogen storage disease type IB.
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PMID:Impaired chemotaxis and neutrophil (polymorphonuclear leukocyte) function in glycogenosis type IB. 345 31

Abnormal lipid transport is one of the more severe pathophysiological manifestations of glucose-6-phosphatase deficiency (glycogen storage disease, type I: GSD-I). To characterize further lipoprotein abnormalities in this inborn error of glycogen metabolism, we determined the levels of serum apolipoproteins (Apo) A-I, A-II, B, C-I, C-II, C-III, D, and E in 10 male and 12 female patients, 1-37 yr of age. Results showed that patients with GSD-I have a unique apolipoprotein profile characterized by normal or slightly decreased levels of ApoA-I and ApoA-II, reduced concentrations of ApoD, and significantly increased levels of ApoC-I and ApoC-II (p less than 0.01) and ApoB, ApoC-III, and ApoE (p less than 0.0001) in comparison with age- and sex-matched normolipidemic controls. However, there was some overlap of values in patients and controls for each of the lipid and apolipoprotein constituents with the exception of ApoC-III. This finding supported by the results of the logistic regression analysis showed that the concentration of ApoC-III is the best criterion for distinguishing patients with GSD-I from control subjects and the most characteristic feature of the deranged lipid transport system in this deficiency disease. It remains to be clarified, however, whether the ApoC-III concentrations in patients with GSD-I reflect the degree of other metabolic and clinical manifestations of this disease such as hyperlacticacidemia, hyperuricemia, and growth retardation.
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PMID:The serum apolipoprotein profile of patients with glucose-6-phosphatase deficiency. 385 88

Clinical, hematologic, and immunologic findings were reviewed in 21 patients with glycogenosis Ib. Fifteen of the patients suffered from moderate to severe bacterial infections. Ten patients had excessive epistaxis or bleeding from surgical sites, and eight suffered oral and anal mucosal ulceration. Sixteen of 21 patients exhibited chronic neutropenia associated with abnormalities in myeloid maturation and decreases in the bone marrow storage and peripheral marginating pools. Diminished neutrophil motility was documented in 14 of 15 patients tested, and adherence was decreased in three patients studied. Neutrophil microbicidal activity, reduction of nitroblue tetrazolium, and ingestion were normal in all patients tested. Bleeding times were prolonged in five of eight patients, and results of platelet function studies were abnormal in five individuals. Excessive bleeding in patients with glycogenoses Ia and Ib are similar and may be secondary to the functional deficiency of glucose-6-phosphatase. However, neutropenia, neutrophil dysfunction, and the resulting infectious complications are specific for Ib disease and may be related to abnormal glucose-6-phosphate transport.
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PMID:Infectious and bleeding complications in patients with glycogenosis Ib. 386

Palmitate, glucose, and glycerol oxidation to CO(2) have been investigated in the fasted state in ten normal subjects and nine patients (six hyperlipoproteinemias, one xanthomatosis, and two glycogenosis) after intravenous injection of [1-(14)C]palmitate, [1-(14)C]glucose, or [1-(14)C]glycerol in tracer amounts. The specific activities and concentrations of plasma palmitate, glycerol, or glucose and expired CO(2) were measured at various intervals after the injection for a period of 24 h. All the studies were analyzed in terms of a multicompartment model describing the structure for each of the subsystems, the transfer of carbon label between subsystems, and the oxidation to CO(2). A bicarbonate subsystem was also included in the model to account for its role in shaping the CO(2) curves. All the CO(2) activity following a palmitate injection could be accounted for by a direct oxidative pathway from plasm FFA with the addition of a 20-min delay compartment. The same also applied to glucose, except that the delay compartment had a mean time of about 150 min. Only about a third of the injected glycerol was directly oxidized to CO(2) from plasma; the delay time was about 4 min. Most of the remainder was converted to glucose. In normals about 45% of the FFA is oxidized to CO(2) directly. This constitutes about 30% of the total CO(2) output. In hyperlipemia the CO(2) output is nearly unchanged and the contribution from FFA is nearly the same. There is a considerable increase (factor of 2), however, in FFA mobilization, most of which is probably diverted to triglyceride synthesis. The glucose and glycerol subsystems are roughly the same in normals and hyperlipemics. About 50% of glucose is oxidized by the direct pathways which accounts for about 35% of the CO(2) output. Glycerol accounts for only 1.5% of the CO(2) produced. Major changes occurred in the glycerol and glucose subsystems in glycogenosis. The changes are consistent with the known deficiency in glucose-6-phosphatase in this disorder. There is a considerable reduction (factor of 2 or more) in the release of glucose to plasma (gluconeogenesis) and in the conversion of glycerol to glucose. Despite the integration of the kinetics of the glucose, glycerol, and FFA subsystems over a 24-h period, 36% of the CO(2) production was still unaccounted for in normals and 50% in hyperlipemics. Thus, some of the carbon must wind up in very slowly turning-over pools which supply CO(2) through subsystems not covered in these studies (triglycerides, glycogen, amino acids, etc.). All the modeling was carried out with the aid of the SAAM25 computer program.
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PMID:Interrelations in the oxidative metabolism of free fatty acids, glucose, and glycerol in normal and hyperlipemic patients. A compartmental model. 452 90

Patients with glycogen storage disease (GSD) type 1b have shown normal activity of glucose-6-phosphatase (EC 3.1.3.9) as assayed in frozen liver, though their clinical and biochemical findings were similar to those of patients with GSD 1a (McKusick 23220) (Senior and Loridan, 1968). In 1978, we suggested that a basic defect of GSD 1b exists in the glucose-6-phosphate (G6P) transport system (Narisawa et al., 1978; Igarashi et al., 1979). Since then, there have been reports confirming our observation (Beaudet et al., 1980; Lange et al., 1980; Corbeel et al., 1981; Schaub et al., 1981). Recently, it was postulated that the G6Pase system contains a phosphate translocase which mediates the efflux of phosphate, in addition to a G6P translocase and a non-specific phosphohydrolase (Arion et al., 1980). Therefore, it is possible that GSD 1b is caused by a defect of phosphate translocase. In this paper, the basic defect in GSD type 1b was investigated in two patients; one with severe, the other with mild, clinical symptoms.
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PMID:Glycogen storage disease type 1b due to a defect of glucose-6-phosphate translocase. 613 35

The basic defect in glycogen storage disease (GSD) type 1b was investigated in two patients: one, (Y.S.), a severely affected infant and the other, (Y.M.), an adult with mild clinical symptoms. The enzymatic studies on liver needle biopsy specimens from the two patients indicated that glucose-6-phosphate (G-6-P) phosphohydrolase activity of the "intact microsomes" was partially deficient (20% of that in controls) in Y.M. and undetectable in Y.S. Activities of G-6-P phosphohydrolase in the disrupted microsomes of Y.S. and Y.M. are higher than those in the disrupted microsomes of controls (12.60 mumole/min/g liver in Y.S., 9.18 in Y.M. and 6.26 +/- 1.22, mean +/- S.D. in controls). Our study also shows that PPi phosphohydrolase activities of the "intact microsomes" from both patients (6.07 mumol/min/g liver in Y.S. and 5.36 in Y.M.) were greater than those of the controls (3.23 +/- 0.77 mumole/min/g wet weight liver). These results indicate that the G-6-P translocase was the locus of the defect in both patients with GSD type 1b. Clinical symptoms and enzymatic studies suggest that the clinical severity of this disorder depends on the level of residual activities of G-6-P translocase. Kinetic studies showed an abnormally high Km of the residual G-6-P translocase in Y.M., suggesting a structural gene mutation. The systematic assay method for glucose-6-phosphatase system, which requires only 15 mg of liver tissues, is also described.
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PMID:Glycogen storage disease type 1b: microsomal glucose-6-phosphatase system in two patients with different clinical findings. 613 4

Glycogen storage diseases constitute a highly heterogeneous group of disorders, because of the many complex enzyme systems involved in glycogen metabolism, and also because of the diversity of molecular defects connected with gene mutations. To illustrate these features, the authors studied four types of liver glycogen storage diseases, respectively caused by deficiencies of glucose-6-phosphatase, debranching enzyme, phosphorylase and phosphorylase kinase. In each case, the role and functional characteristics of the enzyme system are described, as well as the bioclinical aspects of the deficiency. The only reliable way of diagnosing glycogen storage disease is by assaying the activity of the enzyme concerned. Assay procedure must take account of various factors, especially the progress made in understanding the nature and mechanism of action of enzyme systems, the possible tissular heterogeneity of the deficiency and the functional characteristics of certain enzymes.
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PMID:[Genetic heterogeneity and the diagnosis of hepatic glycogenoses]. 624 Oct 11

A girl presented with an important growth retardation, hepatomegaly, fasting hypoglycemia, lactic acidosis, increased serum cholesterol, triglycerides and uric acid, and increased liver glycogen (7.5%). There was no rise in blood glucose after IV galactose or fructose, but glucagon gave a delayed response. Type Ib glycogen storage disease was suggested by the low normal activity of glucose-6-phosphatase (G-6-Pase) which reached 1.8 units/g (normal, 2 to 10 units/g) and the normal activity of other glycogenolytic enzymes, measured in homogenates prepared in H2O (mean +/- S.E. in control subjects: 59% +/- 7; in type Ia GSD: 92% +/- 3). The activity of G-6-Pase measured as described above increased to 3.8 units/g of liver 1 year after PCS and 7.85 units/g of liver after 3 years. At that time, a simultaneous assay of the enzyme in a fresh, previously not frozen liver biopsy, homogenized in 0.25 M sucrose, revealed only about 29% of the activity of the same sample prepared in H2O (mean +/- S.E. in three controls: 95.8% +/- 8.9.
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PMID:Clinical and biochemical findings before and after portacaval shunt in a girl with type Ib glycogen storage disease. 625 80


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