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

---

Query: UMLS:C0019209 (hepatomegaly)
5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abnormal liver tests, right upper quadrant pain and hepatomegaly occurring in an obese or in a diabetic patient may point to the presence of fat or of glycogen accumulation in the liver parenchymal cells. Marked hepatomegaly due to cytoplasmic glycogen deposition is mainly found in poorly controlled insulin-dependent diabetic patients. If accompanied by cushingoid features, growth retardation and by delayed puberty, a diagnosis of Mauriac syndrome can be made. Hyperglycaemia, insulin administration and increased concentrations of the counterregulatory hormone cortisol may all play a role in the glycogen deposition by their concerted actions on the glycogen phosphorylase and synthase enzymes, promoting the accumulation of glycogen. Hypercortisolism may be responsible for growth retardation and delayed puberty in Mauriac patients. Regression of hepatomegaly and of the associated clinical characteristics may be obtained by a better metabolic control due to the administration of long-acting insulin and the change from single to twice daily injections. Fatty liver is rare in insulin-dependent diabetic patients and is indicative of a poor diabetic control. This process is quickly reversible by adequate insulin treatment. Steatosis is frequently found in maturity-onset diabetics and in obese patients. The pathogenetic mechanisms leading to the accumulation of triglycerides and of fatty acids in the hepatocytes can easily be understood from the normal cycling of fatty acids between the adiopose tissue and the liver. Histologic features of nonalcoholic steatohepatitis can also be found in obese and in diabetic patients. Steatohepatitis may rarely evolve into cirrhosis. In general, there is no correlation between the degree of the biochemical alterations and the severity of the histological findings.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Liver disturbances in obesity and diabetes mellitus. 858 Oct 74

We studied 20 children with a clinical picture and laboratory study suggestive of hepatic glycogenosis. The age of the beginning of symptoms varied from birth to 24 months and the age at the diagnosis varied from 2 to 81 months. Hepatomegaly was found in all patients, diarrhea in 65% (13/26), "doll-face" in 55% (11/20) and convulsions in 50% (10/20). Nutritional evaluation showed more height deficiency than weight deficiency. Laboratory tests showed elevation of hepatic transaminases (12/19), hypercolesterolemia (8/14), hyperuricemia (6/17) and hypoglycemia (6/20). Liver function was not compromised in most of the cases. The results of glucagon tolerance test were variable. The histoenzymology study performed in 15 patients revealed the following results: Type VI (liver phosphorylase deficiency) in seven, Type I (glucose-6-phosphatase deficiency) in two, Type IV (brancher enzyme) in one and no conclusion could be drawn in five patients. The finding of hypoglycemia in few cases of this study can be justified by the few number of glycogenosis Type I, probably due to the fact that this type is the most easily diagnosed, with less necessity of referring them to specialized centers.
...
PMID:[Hepatic glycogenosis in childhood: clinical and laboratory findings in 20 patients]. 872 90

Glycogen storage disease type VI (GSD6) defines a group of disorders that cause hepatomegaly and hypoglycemia with reduced liver phosphorylase activity. The course of these disorders is generally mild, but definitive diagnosis requires invasive procedures. We analyzed a Mennonite kindred with an autosomal recessive form of GSD6 to determine the molecular defect and develop a non-invasive diagnostic test. Linkage analysis was performed using genetic markers flanking the liver glycogen phosphorylase gene ( PYGL ), which was suspected to be the cause of the disorder on biochemical grounds. Mennonite GSD6 was linked to the PYGL locus with a multipoint LOD score of 4.7. The PYGL gene was analyzed for mutations by sequencing genomic DNA. Sequencing of genomic DNA revealed a splice site abnormality of the intron 13 splice donor. Confirmation of the genomic mutation was performed by sequencing RT-PCR products, which showed heterogeneous PYGL mRNA lacking all or part of exon 13 in affected persons. This study is the first to demonstrate that a mutation in the PYGL gene can cause GSD6. This mutation is estimated to be present on 3% of Mennonite chromosomes and the disease affects 0.1% of that population. Determination of this mutation provides a basis for the development of a simple and non-invasive diagnostic test for the disease and the carrier state in this population and confirms biochemical data showing the importance of this gene in glucose homeostasis.
...
PMID:Identification of a mutation in liver glycogen phosphorylase in glycogen storage disease type VI. 953 91

We identified a novel mutation in the glycogen phosphorylase gene (PGYL) in a Chinese patient with glycogen storage disease (GSD) type VI. The patient presented with gross hepatomegaly since the age of two without history of any hypoglycemic attack. Otherwise, he was largely asymptomatic. Liver tissue enzyme assays revealed a mild deficiency of total glycogen phosphorylase. Both PGYL and PHKA2 genes were sequenced. The patient was homozygous of a missense mutation G233D in PGYL. This location forms a hairpin turn secondary structure and the small glycine residue is completely conserved in all the orthologous proteins from Escherichia coli to mammals. This is the sixth reported mutation of this form of GSD.
...
PMID:A novel mutation (G233D) in the glycogen phosphorylase gene in a patient with hepatic glycogen storage disease and residual enzyme activity. 1280 46

Glycogen storage diseases are a rare group of disorders in daily pediatric practice but must be taken into account when a patient presents with poor physical growth, hepatomegaly, hypoglycemia, hypotonia and/or other metabolic disturbances. Early diagnosis allows treatment that might improve the patient's outcome to be started or, at the very least, genetic counseling to be given to the parents. We present a 10-month-old boy who presented with growth retardation, abdominal distention and hepatomegaly and who was finally diagnosed with glycogenosis type IX. Definitive diagnosis was obtained by demonstrating the enzyme defect (phosphorylase beta-kinase) in affected tissues. Enteral nutrition was started using a diurnal high-carbohydrate diet with frequent feedings and nocturnal nasogastric continuous feeding, achieving optimal growth parameters and clinical response.
...
PMID:[Glycogen storage disease type IX presenting as abdominal distention, hepatomegaly and hypoglycemia during infancy]. 1553 Mar 25

The aim of this study was the evaluation of the effects of a subchronic exposure to malathion, an organophosphorus (OP) insecticide, on plasma glucose and hepatic enzymes of glycogenolysis and glycolysis in rats in vivo. Malathion was administered intragastrically by stomach tube in the amount of 1 ml corn oil containing 100mg/kg body weight (BW) daily for 32 days. At the end of the experiment, the liver was removed. The activities of glycogen phosphorylase (GP) and hexokinase (HK) were analysed in the homogenate. The methodology employed was a non-denaturing electrophoresis followed by activity-staining (native PAGE). Malathion decrease GP activity by 50% and increase HK activity by 10%. In addition, an hepatomegaly was recorded with a rise in the hepatic glycogen rate in malathion-treated rats. Moreover, subchronic administration of malathion has no effect on blood glucose concentration. The storage of glycogen in liver may be due to a stimulation of insulin secretion after the inhibition of acethylcholinesterase activity in pancreatic beta cells by malathion. These findings were in favour of an activation of glycogen storage by malathion.
...
PMID:Effect of subchronic exposure to malathion on glycogen phosphorylase and hexokinase activities in rat liver using native PAGE. 1662 Dec 13

Glycogen storage diseases (GSD) are inherited metabolic disorders of glycogen metabolism. Different hormones, including insulin, glucagon, and cortisol regulate the relationship of glycolysis, gluconeogenesis and glycogen synthesis. The overall GSD incidence is estimated 1 case per 20000-43000 live births. There are over 12 types and they are classified based on the enzyme deficiency and the affected tissue. Disorders of glycogen degradation may affect primarily the liver, the muscle, or both. Type Ia involves the liver, kidney and intestine (and Ib also leukocytes), and the clinical manifestations are hepatomegaly, failure to thrive, hypoglycemia, hyperlactatemia, hyperuricemia and hyperlipidemia. Type IIIa involves both the liver and muscle, and IIIb solely the liver. The liver symptoms generally improve with age. Type IV usually presents in the first year of life, with hepatomegaly and growth retardation. The disease in general is progressive to cirrhosis. Type VI and IX are a heterogeneous group of diseases caused by a deficiency of the liver phosphorylase and phosphorylase kinase system. There is no hyperuricemia or hyperlactatemia. Type XI is characterized by hepatic glycogenosis and renal Fanconi syndrome. Type II is a prototype of inborn lysosomal storage diseases and involves many organs but primarily the muscle. Types V and VII involve only the muscle.
...
PMID:Glycogen storage diseases: new perspectives. 1755 1

Deficiency of liver glycogen phosphorylase in glycogen storage disease (GSD) type VI results in a reduced ability to mobilize glucose from glycogen. Six mutations of the PYGL gene, which encodes the liver isoform of the enzyme, have been identified in the literature. We have characterized eight patients from seven families with GSD type VI and identified 11 novel PYGL gene defects. The majority of the mutations were missense, resulting in the substitution of highly conserved residues. These could be grouped into those that were predicted to affect substrate binding (p.V456M, p.E673K, p.S675L, p.S675T), pyridoxal phosphate binding (p.R491C, p.K681T), or activation of glycogen phosphorylase (p.Q13P) or that had an unknown effect (p.N632I and p.D634H). Two mutations were predicted to result in null alleles, p.R399X and [c.1964_1969inv6;c.1969+1_+4delGTAC]. Only 7 of the 23 (30%) reported PYGL alleles carry nonsense, splice site or frameshift mutations compared to 68-80% of affected alleles of the highly homologous muscle glycogen phosphorylase gene, PYGM, that underlie McArdle disease. There was heterogeneity in the clinical symptoms observed in affected individuals. These varied from hepatomegaly and subclinical hypoglycaemia, to severe hepatomegaly with recurrent severe hypoglycaemia and postprandial lactic acidosis. We conclude that deficiency of liver glycogen phosphorylase is predominantly the result of missense mutations affecting enzyme activity. There are no common mutations and the severity of clinical symptoms varies significantly.
...
PMID:High frequency of missense mutations in glycogen storage disease type VI. 1770 25

The preclinical efficacy and safety of GPi921, a glycogen phosphorylase inhibitor, was assessed following twenty-eight days of administration to Zucker Diabetic Fatty (ZDF) rats. The ZDF rat is an animal model of type 2 diabetes mellitus (TTDM) which develops severe hyperglycemia. Inhibition of glycogen phosphorylase throughout the duration of the study was demonstrated by reductions in twenty-four-hour glucose profiles and glycated hemoglobin levels. In addition, progression towards hyperglycemia was halted in treated but not control animals, which developed hyperglycemia over the twenty-eight days of the study. Biochemical and histopathological analysis revealed large increases in hepatic glycogen, which closely paralleled the development of hepatomegaly and ultimately resulted in increases in hepatic lipids. Furthermore, prolonged glycogen phosphorylase inhibition resulted in an increased incidence and severity of other adverse pathological findings in the liver, such as inflammation, fibrosis, hemorrhage, and necrosis. The observed biochemical and histopathological phenotype of the liver closely resembled that seen in severe cases of human glycogen storage diseases (GSD) and hepatic glycogenosis in poorly controlled diabetes mellitus. These findings revealed that although glycogen phosphorylase inhibitors are efficacious agents for the control of hyperglycemia, prolonged treatment might have the potential to cause significant clinical hepatic complications that resemble those seen in GSD and hepatic glycogenosis.
...
PMID:Prolonged inhibition of glycogen phosphorylase in livers of Zucker Diabetic Fatty rats models human glycogen storage diseases. 2103 3

Glycogen storage disease (GSD) due to a deficient hepatic phosphorylase system defines a genetically heterogeneous group of disorders that mainly manifests in children. We investigated 45 unrelated children in whom a liver GSD VI or IX was suspected on the basis of clinical symptoms including hepatomegaly, increased serum transaminases, postprandial lactatemia and/or mild fasting hypoglycemia. Liver phosphorylase and phosphorylase b kinase activities studied in peripheral blood cells allowed to suspect diagnosis in 37 cases but was uninformative in 5. Sequencing of liver phosphorylase genes was useful to establish an accurate diagnosis. Causative mutations were found either in the PYGL (11 patients), PHKA2 (26 patients), PHKG2 (three patients) or in the PHKB (three patients) genes. Eleven novel disease causative mutations, five missense (p.N188K, p.D228Y, p.P382L, p.R491H, p.L500R) and six truncating mutations (c.501_502ins361pb, c.528+2T>C, c.856-29_c.1518+614del, c.1620+1G>C, p.E703del and c.2313-1G>T) were identified in the PYGL gene. Seventeen novel disease causative mutations, ten missense (p.A42P, p.Q95R, p.G131D, p.G131V, p.Q134R, p.G187R, p.G300V, p.G300A, p.C326Y, p.W820G) and seven truncating (c.537+5G>A, p.G396DfsX28, p.Q404X, p.N653X, p.L855PfsX87, and two large deletions) were identified in the PHKA2 gene. Four novel truncating mutations (p.R168X, p.Q287X, p.I268PfsX12 and c.272-1G>C) were identified in the PHKG2 gene and three (c.573_577del, p.R364X, c.2427+3A>G) in the PHKB gene. Patients with PHKG2 mutations evolved towards cirrhosis. Molecular analysis of GSD VI or IX genes allows to confirm diagnosis suspected on the basis of enzymatic analysis and to establish diagnosis and avoid liver biopsy when enzymatic studies are not informative in blood cells.
...
PMID:Liver glycogen storage diseases due to phosphorylase system deficiencies: diagnosis thanks to non invasive blood enzymatic and molecular studies. 2164 31


<< Previous 1 2 3 Next >>

---