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)

The kinetics and distribution of [3H]tryptamine binding sites in human brain were investigated. Specific [3H]tryptamine binding in frontal cortex was of nanomolar affinity, reversible, saturable, and best fit to a single-site model. A heterogeneous distribution for this binding site was demonstrated, with the highest density observed in hippocampus, thalamus >> caudate nucleus, frontal cortex, pons, temporal cortex > globus pallidus/putamen, cerebellum. The similarities in kinetics and distribution of the [3H]tryptamine binding site in human and rat brain indicate that these two binding sites represent homologous structures. However, the present displacement studies using various ligands (indoleamines and other tryptophan metabolites, phenylethylamines, and miscellaneous drugs) and salts (Na+, K+, Ca2+, Mg2+, Cu2+) indicate stereospecific displacement as well as a rank-order potency profile that is different from that reported for the rat [3H]tryptamine binding site. This suggests the presence of distinct species-dependent [3H]tryptamine binding site subtypes. Taken together with the documented electrophysiological and behavioral evidence of tryptamine-mediated effects in the rat and the recent report of a significant loss of these binding sites in human portal systemic encephalopathy, as well as the present demonstration of an effect of guanine nucleotides on [3H]-tryptamine binding affinity, these findings suggest that these binding sites might be functional receptors. The implied role of tryptamine in neuropsychiatric disorders is supported by this demonstration of a receptor for [3H]-tryptamine in human brain.
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PMID:The [3H]tryptamine receptor in human brain: kinetics, distribution, and pharmacologic profile. 805 46

The eosinophilia-myalgia syndrome (EMS), a multisystem disorder associated with ingestion of L-tryptophan-containing products, causes sclerodermatous skin changes, cardiopulmonary disease, and a range of peripheral neurologic complications. Many EMS patients also report cognitive difficulty in association with the disease. To determine the frequency of objective neurocognitive impairment in EMS patients with subjective complaints of cognitive difficulty and to assess the relationship of neurocognitive loss with demographic features, degree of peripheral eosinophilia, and psychiatric diagnosis, we compared 24 EMS patients with 32 age- and education-matched healthy controls, using a comprehensive neuropsychological test battery. EMS patients additionally underwent a psychiatric interview and rheumatologic evaluation. Sixty-two percent (15 of 24) of the EMS patients demonstrated neurocognitive deficits. Compared with healthy controls, EMS patients demonstrated significant impairment on tests of verbal memory, visual memory, conceptual reasoning, and motor speed. Cognitively impaired EMS patients did not differ from those without cognitive impairment on demographic markers, degree of peripheral eosinophilia, presence of peripheral neuropathy, or frequency of concurrent psychiatric disorder, including major depression. These data support the hypothesis that EMS is associated with an encephalopathy in addition to its previously recognized peripheral neuropathy and other rheumatologic manifestations.
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PMID:Neurocognitive dysfunction in the eosinophilia-myalgia syndrome. 849 48

Six of nine children born from first-cousin parents presented with the same clinical picture: non-progressive congenital encephalopathy with marked hypertonia resembling the stiff-baby syndrome, delayed milestones, mental deficiency and congenital deafness. Rare, usually reversible, episodes of sudden worsening of the neurological status, with progressive loss of consciousness and increase of hypertonia, occurred spontaneously or during febrile illnesses. During these periods, and sometimes on other occasions, transitory renal dysfunction was observed (nephrotic syndrome and/or tubular abnormalities). Death occurred before age 2 years in 4 patients; 2 are still alive (10 and 13 years old). Electrophysiological, biological and enzymatic investigations remained negative, particularly those concerning mitochondrial and peroxisomal metabolism. The only biochemical anomaly was a massive hyperkynureninuria, seen only during the periods of coma (up to 213 mumol/mmol creatinine; normal < 10) and after an intravenous protein loading test. This suggests an anomaly of tryptophan metabolism which has not been reported up to now.
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PMID:Congenital non-progressive encephalopathy and deafness with intermittent episodes of coma and hyperkynureninuria. 883 Jan 73

Numerous studies suggest that modifications in concentrations of both excitatory and inhibitory amino acids are implicated in the pathophysiology of portal-systemic encephalopathy (PSE), a neuropsychiatric disorder associated with chronic liver disease in humans. In this study, amino acid levels were measured by High Performance Liquid Chromatography (HPLC) in Cerebrospinal Fluid (CSF) of 10 dogs (age range: 3 mo.- 3 yr 4 mo.) exhibiting a congenital portal-systemic shunt, either intra or extra-hepatic, and 8 age-matched control dogs who showed no signs of hepatic or neurologic disorders. Dogs with congenital shunts manifested signs of encephalopathy such as disorientation, head pressing, vocalization, depression, seizures and coma. CSF from dogs with congenital shunts contained significantly increased amounts of glutamate (2 to 3-fold increase, p<0.01), glutamine (6-fold increase, p<0.05) and aromatic amino acids (phenylalanine, tyrosine and tryptophan) compared to CSF of control dogs. Concentrations of GABA and branched chain amino acids (valine, leucine, isoleucine) were within normal limits. Modifications of brain glutamate (an excitatory amino acid) as well as tryptophan (the precursor of serotonin) could contribute to the neurological syndrome characteristic of congenital PSE in dogs.
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PMID:Selective alterations of cerebrospinal fluid amino acids in dogs with congenital portosystemic shunts. 947 3

Two cases of glutaric aciduria type 1 (GA 1) are presented. GA 1 is probably underdiagnosed and misdiagnosed, and may explain a proportion of cases of extrapyramidal and 'postencephalitic' cerebral palsy. Most cases of GA 1 present with a severe dystonic-dyskinetic syndrome following an acute encephalopathy. Asymptomatic cases have also been described, complicating genetic counselling and prenatal diagnosis. We raise awareness of GA 1 and stress that if clinically suspected, immediate institution of therapy may reduce late morbidity. Moreover, if recognised in the presymptomatic stage, early institution of treatment may prevent the onset of neurological symptoms. GA 1 is an inborn error of lysine and tryptophan catabolism, caused by deficiency of the enzyme, glutaryl coenzyme-A dehydrogenase. Urine organic acid analyses may be negative. Blood acylcarnitine profile has recently been employed as a more sensitive test but was negative in both our patients. Enzyme assay remains the definitive diagnostic test.
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PMID:Glutaric aciduria type 1: an underdiagnosed cause of encephalopathy and dystonia-dyskinesia syndrome in children. 963 84

Portacaval anastomosis (PCA) in the rat is used as a model for portal systemic encephalopathy. Changes in the serotonergic, histaminergic, and catecholaminergic neurotransmitter systems are often found shortly after PCA. We have examined the long-term effects of PCA on the aminergic systems in brains of male Wistar rats, which 8 months previously had been subjected to PCA. Precursors, amines, and metabolites were assayed by HPLC. Eight months after PCA, the catecholamine levels were unchanged in all brain regions. In contrast, tryptophan was evenly increased throughout the brain. The accumulation of 5-hydroxytryptophan after decarboxylase inhibition (NSD-1015; 100 mg/kg i.p.) and the endogenous levels of 5-hydroxyindoleacetic acid were significantly higher in PCA rats, particularly in the hypothalamus and midbrain, whereas 5-hydroxytryptamine concentrations were unchanged. Histamine levels were elevated throughout the brain with the greatest increase found in the hypothalamus and in the striatum. tele-Methylhistamine levels were significantly elevated in cortex and hypothalamus. We conclude that 8 months after PCA, catecholaminergic systems had reestablished their homeostasis, whereas serotonergic and histaminergic systems still show profound disturbances in their function. With histamine, this is reflected as an increase in the amounts of both transmitter and metabolite; serotonergic neurons respond by increasing only the level of the metabolite.
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PMID:Long-term effects of portacaval anastomosis on the 5-hydroxytryptamine, histamine, and catecholamine neurotransmitter systems in rat brain. 975 Nov 77

Changes in plasma amino acid concentrations were measured in patients with hepatic failure during extracorporeal hemodiabsorption (using the Liver Dialysis Unit, "the Unit") or hemodiabsorption plus sorbent-based pheresis treatment (using the Liver Dialysis Plasmafilter Unit, "the PF-Unit") Systems. Eight patients with hepatic failure, grade 3 or 4 encephalopathy, elevated bilirubin and/or creatinine levels and respiratory or renal failure were treated for 1-3 days with the Unit alone. Three of these were also treated with the Unit containing 10 g of BCAA in the sorbent suspension. Four patients with hepatic failure treated with the PF Unit also had 10 g of branched chain amino acid (BCAA) added to the sorbents of the Unit portion of this device. Pre- and post-plasma samples were drawn and high performance liquid chromatography (HPLC) was used to separate and detect amino acids in the plasma. Both the Unit and the PF-Unit have the capability to selectively remove various amino acids, especially aromatic amino acids (AAA). The pre-treatment amino acid profiles of plasma were typical for hepatic failure, with abnormally high levels of phenylalanine, tyrosine, tryptophan, and methionine and decreased levels of valine, leucine and isbolucine. The average pre-treatment Fischer ratio (BCAA/AAA) for both Unit and PF-Unit patients was 1.43 (+/- 0.58). Treatments by both systems resulted in an increase of BCAA levels in blood and concomitant decrease of AAA levels, with an average Fischer ratio improvement of 30-38% for the Unit and PF-Unit without BCAA. The Fischer ratio improved by 90% (average) for the Unit with BCAA. Levels of many other amino acids (such as alanine, glycine, proline or lysine) increased during both Unit and PF-Unit treatments. The removal of strongly protein-bound toxin and amino acids such as tryptophan and sulphydryl amino acids was more effective by the PF-Unit. Both the Unit and the PF-Unit have the unique capability to remove toxic aromatic amino acids while increasing BCAA levels in patient. The increase in many amino acid levels may be related to the removal of toxins that interfere with normal amino acid metabolism. The addition of the PF module improves the removal of bilirubin and similarly protein-bound chemicals. Changes in amino acid profiles by the Unit and the PF-Unit contrast markedly with other extracorporeal devices.
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PMID:Effect of hemodiabsorption and sorbent-based pheresis on amino acid levels in hepatic failure. 1091 55

It has been suggested that alterations of serotonin transport may be implicated in the pathogenesis of the neuropsychiatric symptoms encountered in acute liver failure. In order to address this issue, microdialysate concentrations of serotonin, its precursor L-tryptophan and metabolite 5-hydroxyindoleacetic acid (5-HIAA) as well as brain regional distribution of serotonin transporter ([3H]-citalopram) sites were measured in rats with acute liver failure resulting from hepatic devascularization. A significant loss of [3H]-citalopram sites was observed in dorsal Raphe nucleus, in frontal and frontoparietal cortices as well as in substantia nigra of rats with severe encephalopathy resulting from acute liver failure. In frontal cortex, this loss of transporter binding sites was accompanied by significant increases of L-tryptophan, serotonin and 5-HIAA concentrations in extracellular fluid. Pharmacological manipulation of the brain serotonin system could afford a novel therapeutic approach to the prevention of the neuropsychiatric symptoms characteristic of acute liver failure in humans.
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PMID:Evidence for a serotonin transporter deficit in experimental acute liver failure. 1113 85

23% of all septic patients develop septic encephalopathy which is associated with an increased mortality rate. Symptoms such as agitation, confusion and disorientation ranging from stupor to coma often develop in early sepsis. Severe hypotension is significantly associated with the development of septic encephalopathy. Several other factors which may play a role are also discussed: effects of inflammatory mediators on the brain, inadequate cerebral perfusion pressure, blood-brain barrier derangements, disturbances of the cerebral microcirculation, cerebral ischemia e.g. due to hypocapnia,metabolic changes, altered amino acid levels, transmitter imbalances, liver insufficiency, multiple organ failure and infections of the CNS, respectively. Compared to patients with an isolated infection,patients in septic shock have increased levels of aromatic amino acids such as phenylalanine and tryptophan in the plasma and brain as well as decreased levels of branched chain amino acids. Patients who died had higher levels of aromatic amino acids than the survivors. The correlation between aromatic amino acids and the APACHE II score was significant. The tryptophan metabolite quinolinic acid which can be synthesized in activated macrophages could act as an excitatory transmitter on the N-methyl-D-aspartate (NMDA) -receptor. Observations from experimental models indicate that activated NMDA receptors activate the neuronal isoform of the NO-synthase and other calcium dependent enzymes. This releases free radicals which may damage the DNA and activate the nuclear enzyme Poly-ADP-ribose-synthetase (PARS), resulting in energy depletion and cell death. Sepsis is the main cause of metabolic encephalopathies in critically ill patients. The differential diagnoses include hepatic, renal,hypoxic-ischemic or cardiovascular encephalopathies as well as encephalopathies,metabolic disorders and organ dysfunctions of other origin. Therapeutic interventions are numerous,however, so far only investigated in few controlled studies. The primary therapeutic goal is to maintain an adequate perfusion pressure and to prevent hypoxia and hypocapnia. Although the infusion of branched chain amino acids is controversial, experimental investigations demonstrated improvements improvements in an animal model with septic encephalopathy. Further investigations with respect to glutamate receptor antagonists, new radical scavengers, NO- and PARS-inhibitors may show whether these substances are suitable for the prophylaxis or early therapy of septic encephalopathy.
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PMID:[Septic encephalopathy. Diagnosis und therapy]. 1275 14

This case report describes the rare phenomenon of encephalopathy associated with massive carcinoid tumor. Extensive investigation failed to reveal an obvious cause but a presumptive diagnosis of tryptophan deficiency was made and she was commenced on tryptophan dietary supplements. A rapid and complete response resulted. This case report discusses this unusual case and reviews the literature regarding carcinoid associated encephalopathy.
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PMID:Carcinoid associated encephalitis successfully treated with tryptophan. 1464 70


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