Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019209 (hepatomegaly)
 5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Deficiency of glucose-6-phosphatase (G6Pase), a key enzyme in glucose homeostasis, causes glycogen storage disease type Ia (GSD-Ia), an autosomal recessive disorder characterized by growth retardation, hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, hyperuricemia, and lactic acidemia. G6Pase is an endoplasmic reticulum-associated transmembrane protein expressed primarily in the liver and the kidney. Therefore, enzyme replacement therapy is not feasible using current strategies, but somatic gene therapy, targeting G6Pase to the liver and the kidney, is an attractive possibility. Previously, we reported the development of a mouse model of G6Pase deficiency that closely mimics human GSD-Ia. Using neonatal GSD-Ia mice, we now demonstrate that a combined adeno virus and adeno-associated virus vector-mediated gene transfer leads to sustained G6Pase expression in both the liver and the kidney and corrects the murine GSD-Ia disease for at least 12 months. Our results suggest that human GSD-Ia would be treatable by gene therapy.
Hum Mol Genet 2002 Sep 01
PMID:Sustained hepatic and renal glucose-6-phosphatase expression corrects glycogen storage disease type Ia in mice. 1218 68

We report clinical and genetic characteristics of seven juvenile hemochromatosis (JH) patients (six females, one male) in two unrelated kinships from the southeastern U.S. All had severe iron overload. Mean age at diagnosis was 20 +/- 5 years (range 8-23 years). In six patients, the mean age at onset of signs and symptoms attributable to iron overload was 15 +/- 2 years (12-18 years); an 8-year-old girl had no symptoms. Six of the seven patients had hypogonadotrophic hypogonadism, two had severe cardiomyopathy, seven had hepatomegaly, two had hepatic cirrhosis, and five had hyperpigmentation. Two of four siblings with JH also had Hashimoto thyroiditis. One patient with severe cardiomyopathy improved with therapeutic phlebotomy, medical therapy for congestive heart failure, and a permanent pacemaker; the other died before phlebotomy was initiated. Estimates of average daily iron absorption before phlebotomy-induced iron depletion were 2.3, 3.1, and 1.7 mg in a male and two females, respectively. Both parents of four siblings with JH were heterozygous at two Ch1q loci (D1S1156, D1S2344); each of the four affected siblings was homozygous at both loci. An unaffected sib was heterozygous at D1S1156. One patient was heterozygous for HFE H63D, five others did not have HFE C282Y or H63D, and one was unavailable for testing. We conclude that JH occurs in the southeastern U.S. It is likely that JH allele(s) in at least one of the present kinships occur(s) on Ch1q, and presumably this represents a mutation(s) of the same gene localized to Ch1q in Italian and Greek JH kindreds. The present cases do not have HFE genotypes typical of hemochromatosis diagnosed in adults. Hashimoto thyroiditis, linked to Ch6p in many kinships, did not segregate with JH alleles on Ch1q in the present kinship.
Blood Cells Mol Dis
PMID:Juvenile hemochromatosis in the southeastern United States: a report of seven cases in two kinships. 1248 11

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.
Mol Genet Metab 2003 Jun
PMID:A novel mutation (G233D) in the glycogen phosphorylase gene in a patient with hepatic glycogen storage disease and residual enzyme activity. 1280 46

Veno-occlusive disease (VOD) is an entity described as a triad of pathologic findings including ascites, tender hepatomegaly, and elevated liver enzymes. The prognosis of patients suffering from VOD is highly variable, ranging from slow resolution to the need for liver transplant. The histopathology of VOD has been described by light and electron microscopy. However, the pathogenesis of VOD is still largely unclear. In the present case study, we report the significant findings in a case of pediatric VOD following chemotherapy. We studied the liver biopsy by light and electron microscopes. In addition to previous reported findings of occlusion of the central vein with endothelial cell damage, proliferation and activation of stellate cells, and collagen deposition in the central vein wall, there were prominent activated macrophages within the lumen and wall of central veins. The following mechanism of VOD was proposed: Tissue damage activates monocytes through monocyte chemoattractant protein-1. The secretory macrophages release TGF-beta, which promotes proliferation of stellate cells to cause collagenous thickening of the central vein. The activated stellate cells produce collagen. The normal drainage of the Space of Disse and sinusoids draining into the central vein are blocked by the fibrosis. This leads to extravasated RBCs trapped within the thickened central vein wall and impaction of RBCs in the sinusoids.
Exp Mol Pathol 2003 Dec
PMID:Role of macrophages and stellate cells in the pathogenesis of veno-occlusive disease: an electron microscopic case study. 1461 11

In order to cast light on carcinogen-specific molecular mechanisms underlying experimental hepatocarcinogenesis in rats, in vivo mutagenicity and mutation spectra of known genotoxic rat hepatocarcinogens N-nitrosopyrrolidine (NPYR), and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), as well as the nongenotoxic hepatocarcinogen di(2-ethylhexyl)phthalate (DEHP) and the noncarcinogen acetaminophen (AAP), were investigated in guanine phosphoribosyltransferase (gpt) delta transgenic rats, a recently developed animal model for genotoxicity analysis. After 13-wk treatment, glutathione S-transferase placental form (GST-P)-positive liver cell foci were significantly increased in NPYR-treated and IQ-treated rats. In the DEHP-treated rats, marked hepatomegaly with centrilobular hypertrophy of hepatocytes occurred, although GST-P staining was consistently negative. Positive mutagenicity was detected in IQ- and NPYR-treated rats. Mutant frequencies (MFs) in the liver DNA were 188.0 x 10(-6) and 56.5 x 10(-6), approximately 35-fold and 10-fold higher, respectively, than that of nontreatment control rats (5.5 x 10(-6)). There were no increases in MFs in the DEHP- or AAP-treated rats as compared to the nontreatment control value. IQ induced mainly base substitutions leading to G:C to T:A transversions (56.9%) and deletions of G:C base pairs. In contrast, NPYR primarily caused specific A:T to G:C transitions (49.3%), which are very rare in the other groups. These data provided support for the conclusion that IQ and NPYR hepatocarcinogenesis depends on genotoxic processes and specific DNA adduct formation while DEHP exerts its influence via a nongenotoxic promotional pathway. Our data also indicate that analysis of specific in vivo mutational responses with transgenic animal models can provide crucial information for understanding the molecular mechanisms underlying chemical carcinogenesis.
Mol Carcinog 2005 Jan
PMID:In vivo mutational analysis of liver DNA in gpt delta transgenic rats treated with the hepatocarcinogens N-nitrosopyrrolidine, 2-amino-3-methylimidazo[4,5-f]quinoline, and di(2-ethylhexyl)phthalate. 1548 47

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) results in a broad spectrum of toxic effects. Most, if not all, of these responses are dependent upon the binding of dioxin to the aryl hydrocarbon receptor. Given their common roles in chemically induced toxicity, we asked whether interleukin 1 (IL1)-like cytokines play a role in acute aspects of the dioxin response. To test this idea, we employed a "triple-null" mouse model that lacks the two receptors for the tumor necrosis factors-alpha and -beta and the receptor for the IL1-alpha and IL1-beta cytokines. When triple null mice were treated with dioxin, there was significant attenuation in the levels of serum alanine aminotransferase, signifying reduced hepatocellular damage. In addition, the triple-null mice were protected from dioxin-induced liver inflammation. Loss of receptors for the IL1-like cytokines was not protective for all aspects of dioxin toxicity. Endpoints such as thymic involution, Cyp1a2 induction, hepatomegaly, and hydropic degeneration remain unchanged in this model.
Mol Pharmacol 2005 May
PMID:Aspects of dioxin toxicity are mediated by interleukin 1-like cytokines. 1572 56

Cux-1 is a member of a family of homeobox genes structurally related to Drosophila Cut. Mammalian Cut proteins function as transcriptional repressors of genes specifying terminal differentiation in multiple cell lineages. In addition, mammalian Cut proteins serve as cell-cycle-dependent transcriptional factors in proliferating cells, where they function to repress expression of the cyclin kinase inhibitors p21 and p27. Previously we showed that transgenic mice expressing Cux-1 under control of the CMV immediate early gene promoter develop multiorgan hyperplasia. Here we show that mice constitutively expressing Cux-1 exhibit hepatomegaly correlating with an increase in cell proliferation. In addition, the increase in Cux-1 expression in transgenic livers was associated with a decrease in p21, but not p27, expression. Within transgenic livers, Cux-1 was ectopically expressed in a population of small cells, but not in mature hepatocytes, and many of these small cells expressed markers of proliferation. Transgenic livers showed an increase in alpha-smooth muscle actin, indicating activation of hepatic stellate cells, and an increase in cells expressing chromogranin-A, a marker for hepatocyte precursor cells. Morphological analysis of transgenic livers revealed inflammation, hepatocyte swelling, mixed cell foci, and biliary cell hyperplasia. These results suggest that increased expression of Cux-1 may play a role in the activation of hepatic stem cells, possibly through the repression of the cyclin kinase inhibitor p21.
Mol Carcinog 2005 May
PMID:Hepatomegaly in transgenic mice expressing the homeobox gene Cux-1. 1581 24

The constitutive androstane receptor (CAR, NR1I3) is a central regulator of xenobiotic metabolism. CAR activation induces hepatic expression of detoxification enzymes and transporters and increases liver size. Here we show that CAR-mediated hepatomegaly is a transient, adaptive response to acute xenobiotic stress. In contrast, chronic CAR activation results in hepatocarcinogenesis. In both acute and chronic xenobiotic responses, hepatocyte DNA replication is increased and apoptosis is decreased. These effects are absent in CAR null mice, which are completely resistant to tumorigenic effects of chronic xenobiotic stress. In the acute response, direct up-regulation of Mdm2 expression by CAR contributes to both increased DNA replication and inhibition of p53-mediated apoptosis. These results demonstrate an essential role for CAR in regulating both liver homeostasis and tumorigenesis in response to xenobiotic stresses, and they also identify a specific molecular mechanism linking chronic environmental stress and tumor formation.
Mol Endocrinol 2005 Jun
PMID:Xenobiotic stress induces hepatomegaly and liver tumors via the nuclear receptor constitutive androstane receptor. 1583 21

Detection of hepatic carnitine palmitoyltransferase I (CPT IA) deficiency by metabolite screening may be problematic. The urine organic acid profile is generally said to be normal and no abnormal or increased acylcarnitine species are evident on bloodspot tandem MS examination. We diagnosed CPT IA deficiency presenting with acute encephalopathy +/- hypoglycemia and hepatomegaly in one Bukharan Jewish and two Palestinian Arab infants from consanguineous families. CPT1A mutation analysis identified two novel nonsense mutations, c.1737C>A (Y579X) and c.1600delC (L534fsX), extending the known genetic heterogeneity in this disorder. A distinctive organic aciduria was observed in all three patients, even several days after initiation of treatment and resolution of symptoms. Abnormal findings included a hypoketotic dicarboxylic aciduria with prominence of the C12 dicarboxylic (dodecanedioic) acid. This C12 dicarboxylic aciduria suggests that CPT I may play a role in uptake of long-chain dicarboxylic acids by mitochondria after their initial shortening by beta-oxidation in peroxisomes. In addition, increased excretion of 3-hydroxyglutaric acid was detected in all three patients, a finding previously observed only in glutaric aciduria type 1, ketosis, and short-chain hydroxyacyl-CoA dehydrogenase deficiency. Examination of urine organic acids with awareness of these metabolic findings may lead to improved diagnosis of this seemingly rare disorder.
Mol Genet Metab 2005 Nov
PMID:Novel metabolic and molecular findings in hepatic carnitine palmitoyltransferase I deficiency. 1614 4

The glycogen storage diseases comprise several inherited diseases caused by abnormalities of enzymes that regulate the synthesis or degradation of glycogen. In contrast to the classic hepatic glycogen storage diseases that are characterized by fasting hypoglycemia and hepatomegaly, the liver is not enlarged in GSD0. Patients with GSD0 typically have fasting ketotic hypoglycemia without prominent muscle symptoms. Most children are cognitively and developmentally normal. Short stature and osteopenia are common features, but other long-term complications, common in other types of GSD, have not been reported in GSD0. Until recently, the definitive diagnosis of GSD0 depended on the demonstration of decreased hepatic glycogen on a liver biopsy. The need for an invasive procedure may be one reason that this condition has been infrequently diagnosed. Mutation analysis of the GYS2 gene (12p12.2) is a non-invasive method for making this diagnosis in patients suspected to have this disorder. This mini-review discusses the pathophysiology of this disorder, use of mutation analysis to diagnose GSD0, and the clinical characteristics of all reported cases of GSD0.
Mol Genet Metab 2006 Apr
PMID:Hepatic glycogen synthase deficiency: an infrequently recognized cause of ketotic hypoglycemia. 1633 19


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