Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1762617 (weakness)
 37,932 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

beta-N-Oxalylamino-L-alanine (BOAA) and beta-N-methylamino-L-alanine (BMAA) are chemically related excitant amino acids isolated from the seed of Lathyrus sativus (BOAA) and Cycas circinalis (BMAA), consumption of which has been linked to lathyrism (an upper motor neuron disorder) and Guam amyotrophic lateral sclerosis (ALS), respectively. Both diseases are associated with degeneration of motor neurons. Experimentally, single doses of BOAA or BMAA induce seizures in neonatal mice and postsynaptic neuronal oedema and degeneration in explants of mouse spinal cord and frontal cortex. Preliminary studies show that these behavioural and pathological effects are differentially blocked by glutamate-receptor antagonists. In macaques, several weeks of daily oral doses of BOAA produce clinical and electrophysiological signs of corticospinal dysfunction identical to those seen in comparably well-nourished animals receiving a fortified diet based on seed of Lathyrus sativus. By contrast, comparable oral dosing with BMAA precipitates tremor and weakness, bradykinesia and behavioural changes, with conduction deficits in the principal motor pathway. BOAA and BMAA (or a metabolite thereof) are the first members of the excitotoxin family to have been shown to possess chronic motor-system toxic potential. These observations provide a rational basis for searching for comparable endogenous neurotoxins in sporadic and inherited forms of human motor neuron disease.
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PMID:Discovery and partial characterization of primate motor-system toxins. 310 39

A new patient with Leigh's syndrome (subacute necrotizing encephalomyelopathy due to pyruvate dehydrogenase complex deficiency) is presented. A Turkish boy of consanguinously married healthy parents developed progressive muscle weakness since infancy. At the age of 3 years he was unable to sit, stand or walk. Clinical examination showed general muscle weakness, hypotonia, muscle hypotrophy, bilateral ptosis, partial bilateral external ophthalmoplegia, nystagmus, intention tremor and hypoactive tendon reflexes. The EEG showed diffuse slowing, the cerebral CT scan disclosed mild hydrocephalus e vacuo. Motor nerve conduction velocity was slightly decreased, the EMG revealed signs of neuropathy. In the biopsied muscle only a mild hypotrophy of type 2 fibres was found, no abnormal mitochondria could be detected. The sural nerve was slightly abnormal: loss of large myelinated axons, loss of unmyelinated nerves. CSF protein was elevated to 80 mg/dl, protein electrophoresis revealed the pattern of markedly impaired blood-CSF barrier. Serum lactate and pyruvate were permanently elevated. In the urine the excretion of alanine was raised. The clinical state deteriorated during intercurrent infections; somnolence, vomiting and Cheyne-Stoke's respiration occurred. At the age of 3 1/2 years the child died of pneumonia. In the liver tissue a decreased activity of the pyruvate dehydrogenase complex was found. Neuropathological examination of the brain demonstrated wide-spread changes of Leigh's spongiform encephalopathy. Several enzyme deficiencies have hitherto been associated with Leigh's syndrome: This patients confirms earlier findings that a subgroup of Leigh's syndrome is caused by pyruvate dehydrogenase complex deficiency.
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PMID:[Leigh's subacute necrotizing encephalomyelopathy due to decreased activity of the pyruvate dehydrogenase complex]. 312 26

We report on a patient, now 17 year old, in whom lactic acidosis was detected at the age of 7 while attempting to diagnose the causes of increasing weakness. The laboratory examinations revealed elevated pyruvate, alanine and oxaloacetate levels in serum and also a lowered citrate level. This led us to suspect a disturbance of the pyruvate dehydrogenase complex. Reduced pyruvate dehydrogenase activation in leucocytes and muscle tissue was indeed found. This article reports on the 10 year history of this case and attempts to establish a connection between the various symptoms observed and the underlying metabolic defect.
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PMID:[Lactic acid acidosis with mitochondrial myopathy due to a pyruvate dehydrogenase deficiency]. 391 58

Fraternal twins who had fasting hypoglycemia, hypoketonemia, muscle weakness, and hepatic dysfunction are reported. The hepatic dysfunction occurred only during periods of caloric deprivation. The surviving patient developed a cardiomyopathy. In this sibling, muscle weakness and cardiomyopathy were markedly improved by a diet high in medium chain triglycerides. There was a marked deficiency of muscle total carnitine and a mild deficiency of hepatic total carnitine. Unlike patients with systemic carnitine deficiency, serum and muscle long-chain acylcarnitine were elevated and renal reabsorption of carnitine was normal. It was postulated that the defect in long-chain fatty acid oxidation in this disorder is caused by an abnormality in the mitochondrial acylcarnitine transport. Detailed studies of the cause of the hypoglycemia revealed that insulin, growth hormone, cortisol, and glucagon secretion were appropriate and that it is unlikely that there was a major deficiency of a glycolytic or gluconeogenic enzyme. Glucose production and alanine conversion to glucose were in the low normal range when compared to normal children in the postabsorptive state. The hypoglycemia in our patients was probably due to a modest increase in glucose consumption, secondary to the decreased oxidation of fatty acids and ketones, alternate fuels which spare glucose utilization, plus a modest decrease in hepatic glucose production secondary to decreased available hepatic energy substrates.
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PMID:Hypoglycemia, hepatic dysfunction, muscle weakness, cardiomyopathy, free carnitine deficiency and long-chain acylcarnitine excess responsive to medium chain triglyceride diet. 668 67

The excess enthalpies of the ternary aqueous solutions containing urea and the glycyl-glycine, glycyl-L-alanine, L-alanyl-L-alanine and sarcosyl-sarcosine diketopiperazines respectively have been determined. A weak but favourable enthalpic contribution to the interaction between these solutes is found. The difference between "strong" and "weak" interactions in aqueous solutions of non-electrolytes is stressed and the role of water in the weak, non-specific interactions, is discussed. The consequence of the weakness of the urea-peptide interactions on the binding of urea to the proteins is also briefly discussed.
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PMID:Peptide-urea interaction. Heats of mixing of cyclic dipeptides with urea. 711 31

Mice engineered to express a transgene encoding a human Cu/Zn superoxide dismutase (SOD1) with a Gly93 --> Ala (G93A) mutation found in patients who succumb to familial amyotrophic lateral sclerosis (FALS) develop a rapidly progressive and fatal motor neuron disease (MND) similar to amyotrophic lateral sclerosis (ALS). Hallmark ALS lesions such as fragmentation of the Golgi apparatus and neurofilament (NF)-rich inclusions in surviving spinal cord motor neurons as well as the selective degeneration of this population of neurons were also observed in these animals. Since the mechanism whereby mutations in SOD1 lead to MND remains enigmatic, we asked whether NF inclusions in motor neurons compromise axonal transport during the onset and progression of MND in a line of mice that contained approximately 30% fewer copies of the transgene than the original G93A (Gurney et al., 1994). The onset of MND was delayed in these mice compared to the original G93A mice, but they developed the same neuropathologic abnormalities seen in the original G93A mice, albeit at a later time point with fewer vacuoles and more NF inclusions. Quantitative Western blot analyses showed a progressive decrease in the level of NF proteins in the L5 ventral roots of G93A mice and a concomitant reduction in axon caliber with the onset of motor weakness. By approximately 200 d, both fast and slow axonal transports were impaired in the ventral roots of these mice coincidental with the appearance of NF inclusions and vacuoles in the axons and perikarya of vulnerable motor neurons. This is the first demonstration of impaired axonal transport in a mouse model of ALS, and we infer that similar impairments occur in authentic ALS. Based on the temporal correlation of these impairments with the onset of motor weakness and the appearance of NF inclusions and vacuoles in vulnerable motor neurons, the latter lesions may be the proximal cause of motor neuron dysfunction and degeneration in the G93A mice and in FALS patients with SOD1 mutations.
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PMID:Neurofilaments and orthograde transport are reduced in ventral root axons of transgenic mice that express human SOD1 with a G93A mutation. 938 75

Since 1983 large number of people are being encountered with arsenic toxicity due to drinking of arsenic contaminated water (0.05-3.2 mg/l) in 6 districts of West Bengal. Clinical and various laboratory investigations were carried out on 156 patients to ascertain the nature and degree of morbidity and mortality that occurred due to chronic arsenic toxicity. All the patients studied had typical rain drop like skin pigmentation (being inclusion criteria) while thickening of palm and sole were found in 65.5% patients. Other features included weakness (70%), gastro-intestinal symptoms (58.6%), involvement of respiratory system (57.08%) and nervous system (50.6%). Lung function tests showed restrictive lung disease in 53% (9/17) and combined obstructive and restrictive lung disease in 41% (7/17) of patients. Abnormal electromyography was found in 34.8% (10/29) and altered nerve conduction velocity in 34.8% (10/29) of cases. Enlargement of liver was found in 120 cases (76.9%) while splenomegaly in 31.4% cases. Liver function test showed elevated globulin level in 15.8% and alkaline phosphatase in 51.3%, alanine amino transferase (ALT) in 11.8% and aspartate amino transferase (AST) in 27.6% of cases. Evidence of portal hypertension was found in 33.3% patients. Liver biopsy reports of 45 patients showed non-cirrhotic portal fibrosis in 41, cirrhosis in 2 and normal histology in 2 cases. There was no correlation between the quantity of arsenic taken through water and the level of arsenic in hair, nail, liver tissues and the degree of fibrosis. There were 5 deaths of which one had skin cancer. The various non-cancer manifestations which were observed in these patients were much severe than those reported in similar cases in other parts of the world.
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PMID:Chronic arsenic toxicity in west Bengal--the worst calamity in the world. 960 Nov 81

A six-year-old male cocker spaniel was presented to the Veterinary Medical Teaching Hospital, University of Florida, with a three-week history of generalised weakness and myalgia. Electrodiagnostic evaluation, cerebrospinal fluid analysis and thoracolumbar myelography were unremarkable. Biopsies from vastus lateralis and triceps muscles revealed numerous large lipid droplets within type 1 fibres and to a lesser degree within type 2 fibres. The resting plasma lactate was mildly increased and there was elevated urinary excretion of lactic, pyruvic and acetoacetic acids, increased urinary excretion of carnitine esters, and increased plasma alanine. This pattern of metabolite excretion is consistent with an, as yet undefined, block in oxidative metabolism.
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PMID:Lipid storage myopathy in a cocker spaniel. 1009 40

Expression of a mutant superoxide dismutase 1 (SOD1) gene in transgenic mice induces a gradual degeneration of cholinergic motor neurons in the spinal cord, causing progressive muscle weakness and hindlimb paralysis. Transgenic mice over-expressing the human SOD1 gene containing a Gly-->Ala substitution at position 93 (G93A) were employed to explore the effects of the SOD1 mutation on choline acetyltransferase (ChAT) expression in the striatum, and in the lumbar and cervical spinal cord. These mice showed a progressive loss of their spinal cord motor neurons, and at 130 days of age showed an up-regulation of ChAT mRNA expression in the striatum. On the other hand, ChAT mRNA decreased in cervical and lumbar motor neurons. These findings suggest that cholinergic interneurons in striatum in SOD1 transgenic mice are over-activated in an attempt to compensate for the death of spinal motor neurons.
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PMID:Compensatory mechanism of motor defect in SOD1 transgenic mice by overactivation of striatal cholinergic neurons. 1032 77

Environmental chemicals involved in the etiology of human neurodegenerative disorders are challenging to identify. Described here is research designed to determine the etiology and molecular pathogenesis of nerve cell degeneration in two little known corticomotoneuronal diseases with established environmental triggers. Both conditions are toxic-nutritional disorders dominated by persistent spastic weakness of the legs and degeneration of corresponding corticospinal pathways. Lathyrism, a disease caused by dietary dependence on grass pea (Lathyrus sativus), is mediated by a stereospecific plant amino acid (beta-N-oxalylamino-L-alanine) that serves as a potent agonist at the (RS)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) subclass of neuronal glutamate receptors. A neurologically similar disorder, konzo ("tied legs"), is found among protein-poor African communities that rely for food on cyanogen-containing cassava roots. Thiocyanate, the principal metabolite of cyanide, is an attractive etiologic candidate for konzo because it selectively promotes the action of glutamate at AMPA receptors. Studies are urgently needed to assess the health effects of cassava and other cyanogenic plants, components of which are widely used as food.
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PMID:Food toxins, ampa receptors, and motor neuron diseases. 1046 41


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