Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085584 (encephalopathy)
 18,178 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aluminum is highly oxophilic and its minerals are usually found surrounded by six oxygen atoms. A role for the metal has been established in dialysis encephalopathy and Al-induced osteomalacia. The metal has been implicated in Alzheimer's disease but the issue is at present controversial. Human cell lines of neural origin were utilized to study the effect of lipophilic aluminum acetylacetonate and non-lipophilic aluminum sulfate on cell proliferation and viability. Although analysis of Al species in the cell culture media demonstrated that there are positively charged Al species present in solutions prepared with both Al salts, only the aluminum acetylacetonate salt caused changes in cell proliferation and viability. Therefore, the lipophilic nature of the organic Al salt is a critical determinant of toxicity. The effect of aluminum acetylacetonate was dose-dependent and time-dependent. Neuroblastoma (SK-N-SH) cells were more susceptible to decreased cell proliferation although the lipophilic Al salt was more toxic to the glioblastoma (T98G) cells. While the toxicity of aluminum acetylacetonate was inhibited in the T98G cells by the addition of phosphate, the same treatment did not reverse cell death in the SK-N-SH cells. Thus, the mechanism of Al toxicity appears to be different in the two cell lines. It is possible that the principal neurotoxic target of the metal is glial and when these cells are in a compromised state, this may secondarily impact the neuronal population and thus eventually lead to neurodegeneration.
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PMID:Differential toxicity of aluminum salts in human cell lines of neural origin: implications for neurodegeneration. 1130 52

Treatment of hypercalcemia of malignancy (HCM) is briefly reviewed, available treatments are compared, and treatment guidelines are presented. The most effective strategy is treatment of the underlying malignancy. For patients who have a poor prognosis and no viable treatment options, the most humane course may be no treatment at all since encephalopathy will cloud their consciousness. Patients with mild hypercalcemia (corrected serum calcium concentration < 12 mg/dL) may respond to oral hydration, salt restriction, and ambulation, which encourage the normal bone remodeling process. Patients with moderate (corrected serum calcium concentration 12.0-13.5 mg/dL) to severe (> 13.5 mg/dL) hypercalcemia may require rehydration with 0.9% sodium chloride injection. Furosemide may be indicated to counteract fluid overload from rehydration measures or in patients at risk of developing congestive heart failure. For patients with renal failure not caused by dehydration, dialysis with a calcium-free or low-calcium solution is the treatment of choice. The calciuric effect of rehydration lasts only two to three days, and antiresorptive therapy is indicated for patients who require a longer duration of effect. Calcitonin is useful if a rapid decrease in serum calcium is necessary, but tachyphylaxis limits its use. Corticosteroids should be used only in patients with tumors that produce 1,25-dihydroxycholecalciferol. The use of plicamycin is limited because of adverse effects. Before the availability of zolendronic acid, pamidronate disodium was the treatment of choice, because of its longer duration of action than etidronate disodium and potential safety advantages. Zolendronic acid (discussed elsewhere in this supplement) is likely to supercede pamidronate disodium as the drug of choice for HCM, but the presence of symptoms, the rate of rise in serum calcium concentration, and the overall status of the patient are important considerations in selecting therapy.
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PMID:Conventional treatment of hypercalcemia of malignancy. 1175 6

Diarrhoea, a major cause of morbidity and mortality can be produced by a variety of etiological factors. Management protocol includes assessment of the child, physical examination, lab-evaluation, assessment of severity of dehydration and rehydration therapy using either of the following - WHO - ORS, Home available fluids (HAF), sugar salt solution (SSS), improve WHO-ORS, Amino acid fortified ORS, rice based ORS, low osmolarity ORS. Intravenous fluids are required if patients can't accept orally. Commonly observed electrolyte disturbances are hypernatremia, hyponatremia and hypokalemia. Concussion is a common problem and can result due to electrolyte imbalance, cavernous sinus thrombosis, associated meningitis, shigella encephalopathy and hypoglycemia in undernourished children. Treatment includes i.v. diazepam and i.v. glucose and correction of electrolyte imbalance. Additional treatment interventions include antimicrobial drugs including antibiotics, antimotility drugs, absorbents, nutritional and micro and macro nutrient supplementation.
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PMID:Management of diarrhoea in practice. 1235 21

A 9-year-old boy was admitted to our hospital with daytime urinary incontinence for the past one year. MRI showed craniopharyngioma occupying the third ventricle. The tumor was excised by interhemispheric approach. Because hyponatremia and polyuria with high renal loss of sodium were observed on postoperative day 3, hydrocortisone and DDAVP were replaced. On postoperative day 24, successive general convulsions and hyponatremia recurred, and MRI FLAIR imaging showed marked brain edema in the bilateral parieto-occipital lobes. This finding disappeared late in the course of treatment, and the case was diagnosed as posterior reversible encephalopathy syndrome. The pathophysiology of cerebral salt wasting and posterior reversible encephalopathy syndrome in a craniopharyngioma patient are also discussed in the article.
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PMID:[Prolonged cerebral salt wasting following craniopharyngioma surgery and posterior reversible encephalopathy syndrome: a case report]. 1578 2

Antichymotrypsin (SERPINA3) is a widely expressed member of the serpin superfamily, required for the regulation of leukocyte proteases released during an inflammatory response and with a permissive role in the development of amyloid encephalopathy. Despite its biological significance, there is at present no available structure of this serpin in its native, inhibitory state. We present here the first fully refined structure of a murine antichymotrypsin orthologue to 2.1 A, which we propose as a template for other antichymotrypsin-like serpins. A most unexpected feature of the structure of murine serpina3n is that it reveals the reactive center loop (RCL) to be partially inserted into the A beta-sheet, a structural motif associated with ligand-dependent activation in other serpins. The RCL is, in addition, stabilized by salt bridges, and its plane is oriented at 90 degrees to the RCL of antitrypsin. A biochemical and biophysical analysis of this serpin demonstrates that it is a fast and efficient inhibitor of human leukocyte elastase (ka: 4 +/- 0.9 x 10(6) m(-1) s(-)1) and cathepsin G (ka: 7.9 +/- 0.9 x 10(5) m(-1) s(-)1) giving a spectrum of activity intermediate between that of human antichymotrypsin and human antitrypsin. An evolutionary analysis reveals that residues subject to positive selection and that have contributed to the diversity of sequences in this sub-branch (A3) of the serpin superfamily are essentially restricted to the P4-P6' region of the RCL, the distal hinge, and the loop between strands 4B and 5B.
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PMID:The murine orthologue of human antichymotrypsin: a structural paradigm for clade A3 serpins. 1614 Nov 97

Shiga toxin 1 (Stx1) represents an AB5 toxin produced by enterohemorrhagic Escherichia coli, which cause gastrointestinal diseases in humans that are often followed by potentially fatal systemic complications, such as acute encephalopathy and hemolytic uremic syndrome. The expression of the preferential Stx1 receptor, Gb3Cer/CD77 (Gal alpha1-4Gal beta1-4Glc beta1-1Cer), is one of the primary determinants of susceptibility to tissue injury. Due to the clinical importance of this life-threatening toxin, a combined strategy of preparative high-performance thin-layer chromatography (HPTLC) overlay assay and mass spectrometry was developed for the detection and structural characterization of Stx1-binding glycosphingolipids (GSLs). A preparation of neutral GSLs from human erythrocytes, comprising 21.4% and 59.1% of the high- and low-affinity Stx1-binding ligands Gb3Cer/CD77 and Gb4Cer, respectively, was separated on silica gel precoated HPTLC plates and probed for the presence of Stx1 receptors. Stx1 positive on the one hand and anti-Gb3Cer/CD77 and anti-Gb4Cer antibody positive bands from parallel reference runs on the other hand were extracted with chloroform/methanol/water (30/60/8, v/v/v). These crude extracts were used without any further purification for a detailed structural analysis by nanoelectrospray ionization quadrupole time-of-flight mass spectrometry (nanoESI-QTOF-MS) in the negative ion mode. In all extracts investigated, neutral GSLs were detected as singly charged deprotonated molecular ions, [M-H]-, and neither buffer-derived salt adducts nor coextracted contaminants from the overlay assay procedure or the silica gel layer were observed. For the structural characterization of Stx1- and antibody-binding GSLs low-energy collision-induced dissociation (CID) was applied to high and low abundant receptor species of the crude extracts. All MS/MS spectra obtained contained full series of Y-type ions, B-type ions and additional ions generated by ring cleavages of the sugar moiety. Only analytical quantities in the microgram scale of a single GSL species within the complex GSL mixture were required for the structural MS characterization of Stx1 ligands as Gb3Cer/CD77 and Gb4Cer. This effective combined HPTLC/MS procedure offers a broad range of applications, not only for toxins of bacterial origin, but also for any GSL-binding agents such as plant-derived lectins or human proteins with yet unknown binding specificities.
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PMID:Application of combined high-performance thin-layer chromatography immunostaining and nanoelectrospray ionization quadrupole time-of-flight tandem mass spectrometry to the structural characterization of high- and low-affinity binding ligands of Shiga toxin 1. 1628 17

The management of children with end-stage chronic liver disease and acute liver failure mandates a multidisciplinary approach and intense monitoring. In recent years, considerable progress has been made in developing specific and supportive medical measures, but studies and publications have mainly concerned adult patients. Therapeutic approaches to complications of end-stage chronic liver disease and acute liver failure (e.g. refractory ascites, hepatorenal syndrome, encephalopathy, and cerebral edema) that may be applied to children are reviewed in this article.Mild-to-moderate ascites should be managed by modest salt restriction and oral diuretic therapy in the first instance. Large volume paracentesis associated with colloid volume expansion and diuretic therapy may be effective for acute relief. Treatment of hepatorenal syndrome type 1 with vasopressin analogs (terlipressin) is recommended prior to liver transplantation in order to improve renal function. Prevention and treatment of chronic hepatic encephalopathy are directed primarily at controlling the events that may precipitate hepatic encephalopathy and at reducing ammonia generation and increasing its detoxification or removal. In addition to reduction of gut ammonia production using non-absorbable disaccharides such as lactulose and/or antibacterials such as neomycin, sodium benzoate may be used on a long-term basis to prevent, stabilize, or improve hepatic encephalopathy. The management of hepatic encephalopathy in acute liver failure is considerably more unsatisfactory; treatment is aimed at preventing brain edema and intracranial hypertension. Extracorporeal liver support devices are now used commonly in critically ill children with acute renal failure, advanced hepatic encephalopathy, cerebral edema, intracranial hypertension, and severe coagulopathy. Continuous renal replacement therapy could potentially help support patients until liver transplantation is performed or liver regeneration occurs. The Molecular Adsorbent Recirculating System (MARS or albumin dialysis) is the liver support system most frequently used worldwide in adults and appears to offer distinct advantages over hepatocyte-based systems. There are no specific medical therapies or devices that can correct all of the functions of the liver. Apart from a few metabolic diseases presenting with severe liver dysfunction for which specific medical therapies may preclude the need for liver transplantation, liver transplantation still remains the only definitive therapy in most instances of end-stage chronic liver disease and acute liver failure. Future research should focus on gaining a better understanding of the mechanisms responsible for liver cell death and liver regeneration, as well as developments in hepatocyte transplantation and liver-directed gene therapy.
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PMID:New management options for end-stage chronic liver disease and acute liver failure: potential for pediatric patients. 1649 8

Hepatic hydrothorax was diagnosed in four patients with liver cirrhosis, three men aged 65, 41, and 48 and a woman aged 48. They presented with either right-sided or bilateral pleural-fluid accumulations in the absence of cardiopulmonary disease. In the first man with no concurrent ascites, the disorder was missed, resulting in prolonged chest tube drainage, multiple severe complications and death. In the 41-year-old man chest tube drainage was also associated with complications including renal failure and encephalopathy. Pleurodesis was effective in the woman while in the remaining man hepatic hydrothorax was only a temporary, asymptomatic finding. Pleural effusions in cirrhotic patients should be considered and managed as hepatic hydrothorax unless diagnostic studies reveal a different aetiology. Absence of ascites is not uncommon and should not delay the correct diagnosis. The gradient between pleural and serum albumin concentration is typically more than 11 g/l. Prolonged chest tube drainage is dangerous and should be avoided. In cases refractory to salt restriction and diuretic therapy, transjugular introduction of an intrahepatic portosystemic shunt is the treatment of choice. Recently, pleurodesis combined with thoracoscopic repair ofdiaphragmatic defects has been reported as a potentially effective form of therapy.
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PMID:[Hepatic hydrothorax]. 1692 51

Hypertensive encephalopathy is a potentially fatal condition associated with cerebral edema and the breakdown of the blood-brain barrier (BBB). The molecular pathways leading to this condition, however, are unknown. We determined the role of deltaPKC, which is thought to regulate microvascular permeability, in the development of hypertensive encephalopathy using deltaV1-1 - a selective peptide inhibitor of deltaPKC. As a model of hypertensive encephalopathy, Dahl salt-sensitive rats were fed an 8% high-salt diet from 6 weeks of age and then were infused s.c. with saline, control TAT peptide, or deltaV1-1 using osmotic minipumps. The mortality rate and the behavioral symptoms of hypertensive encephalopathy decreased significantly in the deltaV1-1-treated group relative to the control-treated group, and BBB permeability was reduced by more than 60%. Treatment with deltaV1-1 was also associated with decreased deltaPKC accumulation in capillary endothelial cells and in the endfeet of capillary astrocytes, which suggests decreased microvasculature disruption. Treatment with deltaV1-1 prevented hypertension-induced tight junction disruption associated with BBB breakdown, which suggests that deltaPKC may specifically act to dysregulate tight junction components. Together, these results suggest that deltaPKC plays a role in the development of hypertension-induced encephalopathy and may be a therapeutic target for the prevention of BBB disruption.
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PMID:Sustained pharmacological inhibition of deltaPKC protects against hypertensive encephalopathy through prevention of blood-brain barrier breakdown in rats. 1809 80

Mutations in pyridoxine 5'-phosphate oxidase are known to cause neonatal epileptic encephalopathy. This disorder has no cure or effective treatment and is often fatal. Pyridoxine 5'-phosphate oxidase catalyzes the oxidation of pyridoxine 5'-phosphate to pyridoxal 5'-phosphate, the active cofactor form of vitamin B(6) required by more than 140 different catalytic activities, including enzymes involved in amino acid metabolism and biosynthesis of neurotransmitters. Our aim is to elucidate the mechanism by which a homozygous missense mutation (R229W) in the oxidase, linked to neonatal epileptic encephalopathy, leads to reduced oxidase activity. The R229W variant is approximately 850-fold less efficient than the wild-type enzyme due to an approximately 192-fold decrease in pyridoxine 5'-phosphate affinity and an approximately 4.5-fold decrease in catalytic activity. There is also an approximately 50-fold reduction in the affinity of the R229W variant for the FMN cofactor. A 2.5 A crystal structure of the R229W variant shows that the substitution of Arg-229 at the FMN binding site has led to a loss of hydrogen-bond and/or salt-bridge interactions between FMN and Arg-229 and Ser-175. Additionally, the mutation has led to an alteration of the configuration of a beta-strand-loop-beta-strand structure at the active site, resulting in loss of two critical hydrogen-bond interactions involving residues His-227 and Arg-225, which are important for substrate binding and orientation for catalysis. These results provide a molecular basis for the phenotype associated with the R229W mutation, as well as providing a foundation for understanding the pathophysiological consequences of pyridoxine 5'-phosphate oxidase mutations.
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PMID:Molecular basis of reduced pyridoxine 5'-phosphate oxidase catalytic activity in neonatal epileptic encephalopathy disorder. 1975 1


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