Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019214 (hepatosplenomegaly)
 4,408 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the gamma-glutamyl cycle, hereditary defects have been described in four of the six enzymes namely: gamma-GC synthetase; GSH synthetase; gamma-glutamyl transpeptidase and 5-oxoprolinase. Mutants are still to be found in gamma-glutamyl cyclotransferase and in the dipeptidase. Deficiency of GSH synthatase or gamma-GC synthetases results in low levels of GSH. In gamma-GC synthetase deficiency hemolytic anemia is the most prominent symptom, with or without hepatosplenomegaly. In generalized GSH synthetase deficiency 5-oxoproline is overproduced due to lack of feedback inhibition of gamma-GC synthetase. These patients have metabolic acidosis, 5-oxoprolinuria, hemolytic anemia and about 50% of them also have progressive neurological symptoms. Treatment includes acidosis correction, high doses of vitamin E and C and avoidance of drugs precipitating hemolytic crises in G6PD deficiency. Therapeutic trials with GSH analogues, N-acetylcysteine and GSH esters have been carried out. Glutathione synthetase deficiency restricted to erythrocytes results in hemolytic anemia but no 5-oxoprolinuria. gamma-Glutamyl transpeptidase deficiency is associated with GSH-emia and GSH-uria whereas 5-oxoprolinase deficiency is associated with 5-oxoprolinuria. In diagnostic work it must be emphasized that erythrocytes contain an incomplete gamma-glutamyl cycle; they lack both gamma-glutamyl transpeptidase and 5-oxoprolinase and these enzyme activities must therefore be analyzed in other types of cells such as leukocytes and fibroblasts. It is also important to investigate other patients with inherited defects in the gamma-glutamyl cycle to learn more about the biological role of GSH in man.
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PMID:Patients with genetic defects in the gamma-glutamyl cycle. 967 48

Human health in the past and presently is influenced by the amounts and proportion of chemical elements to which humans have been exposed. Arsenic, as a therapeutic agent was known to ancient Greeks and Romans. Ehrlick introduced organic arsenicals as anti linetic agents but with advent of penicillin these have nearly become obsolete. Once considered toxic, harmful to humans, arsenic is now considered an essential ultra trace element at least in animals. Now the impact of arsenic on health is more from industrial and environmental than medicinal exposure. This article reviews human exposure to arsenic in non occupational population, mostly through drinking water which is a worldwide problem, more so in south East Asia. Sources of arsenic, normal and abnormal levels in blood and tissues levels, old and new methods of estimation of arsenic, mechanism of action of arsenic in experimental animal is briefly reviewed. Old described clinical manifestation of arsenic in humans is briefly reviewed and newly described clinical manifestations in human with special emphasis on atherosclerosis, liver and diabetes are discussed. Proposed biological mechanisms in experimental animals included up regulation of inflammatory signals like cytokines and TNF-alpha, oxidative stress, hypomethylation, decreased DNA repair and apoptosis, cell proliferation, angiogenesis, activation of several enzymes like methyl transferase which converts inorganic arsenic to MMA and DMA, and GSH in in-vivo and in-vitro in experimental rat liver slices. Experimentally NAC (N-Acetyl Cysteine) treatment attenuates oxidative stress in atherosclerosis apoptosis and liver injury. GSH probably plays an important role in deactivation of the intermediate products of arsenic metabolism and prevents peroxidation of membrane lipids. Chronic human exposure has been linked to several systems in the human body: dermal (exfoliative dermatitis, keratosis, vitiligo, skin cancer), peripheral neuropathy, encephalopathy, bronchitis, pulmonary fibrosis, hepatosplenomegaly resembling NCPF, portal hypertension, peripheral vascular disease and BFD, arteriosclerosis and cancers of lung, urinary bladder, other internal organs and diabetes. Experimental and epidemiological evidence support diabetes effect of high level arsenic exposure. Low and moderate exposure to arsenic in drinking water is widely prevalent and may play a role in diabetes prevalence and needs to be studied further. Role of arsenic in Indian arteriosclerosis, diabetes and liver diseases, (cirrhosis, NCPF), need to be studied further. Study of mechanisms and enzymes mentioned need to be studied in humans exposed to arsenic and other xenobiotics. Measuring arsenic exposure, metabolic and biologic effects by newly described and simpler urine proteomics may accelerate our understanding of arsenic on health consequences.
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PMID:Arsenicosis: review of recent advances. 2175 19

Niemann Pick type C (NPC) disease is a progressive lysosomal storage disorder caused by mutations in genes encoding NPC1/NPC2 proteins, characterized by neurological defects, hepatosplenomegaly and premature death. While the primary biochemical feature of NPC disease is the intracellular accumulation of cholesterol and gangliosides, predominantly in endolysosomes, mitochondrial cholesterol accumulation has also been reported. As accumulation of cholesterol in mitochondria is known to impair the transport of GSH into mitochondria, resulting in mitochondrial GSH (mGSH) depletion, we investigated the impact of mGSH recovery in NPC disease. We show that GSH ethyl ester (GSH-EE), but not N-acetylcysteine (NAC), restored the mGSH pool in liver and brain of Npc1-/- mice and in fibroblasts from NPC patients, while both GSH-EE and NAC increased total GSH levels. GSH-EE but not NAC increased the median survival and maximal life span of Npc1-/- mice. Moreover, intraperitoneal therapy with GSH-EE protected against oxidative stress and oxidant-induced cell death, restored calbindin levels in cerebellar Purkinje cells and reversed locomotor impairment in Npc1-/- mice. High-resolution respirometry analyses revealed that GSH-EE improved oxidative phosphorylation, coupled respiration and maximal electron transfer in cerebellum of Npc1-/- mice. Lipidomic analyses showed that GSH-EE treatment had not effect in the profile of most sphingolipids in liver and brain, except for some particular species in brain of Npc1-/- mice. These findings indicate that the specific replenishment of mGSH may be a potential promising therapy for NPC disease, worth exploring alone or in combination with other options.
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PMID:Mitochondrial GSH replenishment as a potential therapeutic approach for Niemann Pick type C disease. 2788 92