Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In male Swiss mice, muscimol produced myoclonic jerks. A 3 mg/kg (i.p.) dose induced this response in all of the mice tested and the peak response of 73 jerks per min was observed between 27 and 45 min. Increasing the brain serotonin levels by the administration of 5-hydroxytryptophan (80-160 mg/kg) in combination with a peripheral decarboxylase inhibitor resulted in an inhibition of the muscimol effect. However, in a similar experiment l-dopa (80-160 mg/kg) was without effect. In doses of 3-10 mg/kg, the serotonin receptor agonist MK-212 caused a dose-dependent blockade of the response of muscimol. Of the benzodiazepines, clonazepam (0.1-0.3 mg/kg) was found to be several fold more potent than diazepam (0.3-3 mg/kg) in blocking the myoclonic jerks. While (-)-baclofen (1-3 mg/kg) proved to be an effective antagonist of muscimol, its (+)-isomer (5-20 mg/kg) lacked this property. Considering the fact that 5-HTP and the benzodiazepines have been found to be beneficial in the management of clinical myoclonus, the muscimol-induced myoclonus seems to be a satisfactory animal model that may prove useful for the development of new drug treatments for this condition. Our present study indicated the possible value of MK-212 and (-)-baclofen in the management of clinical myoclonus.
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PMID:Serotonergic drugs, benzodiazepines and baclofen block muscimol-induced myoclonic jerks in a strain of mice. 611 80

A 3-year-old male mixed-breed dog was treated for an oral defect along the rostral portion of the hard palate and an oronasal fistula secondary to a severe mandibular brachygnathism and persistent canine distemper virus associated myoclonus. This report describes the treatment using a bilateral radical premaxillectomy, oronasal fistula repair, and pulpotomy.
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PMID:Multiple oral procedures performed on a dog with distemper myoclonus. 791 67

Progressive myoclonus epilepsy of Unverricht-Lundborg type (EPM1; MIM 254800) is an autosomal recessive disorder that occurs with a low frequency in many populations but is more common in Finland and the Mediterranean region. It is characterized by stimulus-sensitive myoclonus and tonic-clonic seizures with onset at age 6-15 years, typical electroencephalographic abnormalities and a variable rate of progression between and within families. Following the initial mapping of the EPM1 gene to chromosome 21 (ref. 6) and the refinement of the critical region to a small interval, positional cloning identified the gene encoding cystatin B (CST6), a cysteine protease inhibitor, as the gene underlying EPM1 (ref. 10). Levels of messenger RNA encoded by CST6 were dramatically decreased in patients. A 3' splice site and a stop codon mutation were identified in three families, leaving most mutations uncharacterized. In this study, we report a novel type of disease-causing mutation, an unstable 15- to 18-mer minisatellite repeat expansion in the putative promoter region of the CST6 gene. The mutation accounts for the majority of EPM1 patients worldwide. Haplotype data are compatible with a single ancestral founder mutation. The length of the repeat array differs between chromosomes and families, but changes in repeat number seem to be comparatively rare events.
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PMID:Unstable minisatellite expansion causing recessively inherited myoclonus epilepsy, EPM1. 909 Mar 86

Progressive myoclonus epilepsy of the Unverricht-Lundborg type (EPM1; MIM 254800) is an autosomal recessive disorder characterized by seizures, myoclonus and progression to cerebellar ataxia. EPM1 arises due to mutations in the cystatin B (CSTB) gene which encodes a cysteine proteinase inhibitor. Only a minority of EPM1 alleles carry point mutations, while the majority contain large expansions of the dodecamer CCCCGCCCCGCG repeat which is present at two to three copies in normal individuals. The dodecamer repeat is located in the 5' flanking region of the CSTB gene, presumably in its promoter. The pathological repeat expansion results in a reduction in CSTB mRNA, which may be cell specific. To elucidate the mechanism of this reduction of gene expression, we have studied the putative CSTB promoter in vitro. A 3.8 kb fragment, containing the putative promoter with a 600 bp repeat expansion, showed a 2- to 4-fold reduction in luciferase activity compared with an identical fragment with a normal repeat; this reduction was observed only in certain cell types. Introduction of heterologous DNA fragments of 730 and 1000 bp into the normal promoter, instead of the repeat expansion, showed similarly reduced activity. Terminal deletions of the promoter implicate a putative AP-1 binding site, upstream of the repeat, in CSTB transcription activation. We propose that a novel mechanism of pathogenesis, the altering of the spacing of transcription factor binding sites from each other and/or the transcription initiation site due to repeat expansion, is among the causes of reduction in CSTB expression and thus EPM1.
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PMID:Altered spacing of promoter elements due to the dodecamer repeat expansion contributes to reduced expression of the cystatin B gene in EPM1. 1044 45

To date, at least 12 types of primary dystonia can be distinguished on a genetic basis. A 3-bp deletion in the DYT1 gene causes early onset, generalized torsion dystonia (TD), and mutations in the GTP cyclohydrolase I and the tyrosine hydroxylase genes result in dopa-responsive dystonia (DYT5). A missense change in the D2 dopamine receptor in one large family (DYT11) has recently been implicated in myoclonus-dystonia. Furthermore, seven other loci for dystonia genes have been mapped to chromosomal regions, including a locus for a mixed dystonia phenotype (DYT6), one form of focal dystonia (DYT7), three types of paroxysmal dystonia (DYT8-10), X-linked dystonia-parkinsonism (DYT3), and rapid-onset dystonia-parkinsonism (DYT12). No positive linkage results have yet been obtained for autosomal recessive TD (DYT2) and several other families of different types of dominantly inherited TD (DYT4). In addition, hereditary secondary dystonia may occur as part of familial diseases of the basal ganglia, metabolic and storage disorders, and various X-linked and other familial neurodegenerative syndromes affecting the basal ganglia. It may be anticipated that the traditional clinical and etiological classifications of dystonia will increasingly be replaced by a genetic one and that the identification of more dystonia genes may lead to a better understanding of these largely nondegenerative disorders.
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PMID:[Genetics of dystonia]. 1091 37

A 3-year-old female pug presented with general seizure following a partial seizure. During the remaining 48 months till death, the dog showed various neurological signs such as disturbance of consciousness, myoclonus and various types of partial seizure after each occurrence of the seizure clusters, and the dog eventually exhibited inability to stand and dementia. Magnetic resonance imaging findings revealed atrophy of the brain over the course of the disease. On histopathological analysis, the dog was diagnosed with necrotizing meningoencephalitis. This case of a canine necrotizing meningoencephalitis observed over the long term is valuable.
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PMID:A canine case of necrotizing meningoencephalitis for long-term observation: clinical and MRI findings. 1805 39

We present a case of pediatric primary cervical neuroblastoma (NB), which is extremely rare. A 3-year-old girl with ataxia but no nasal obstruction, dysphagia, or stridor was diagnosed with cervical NB. Diagnostic results including clinical chemistry, full blood count, and serology, were normal. Ataxia worsened within a few days after onset and was not cured by steroids or intravenous immunoglobulin, delaying a definite diagnosis until a tumor was detected. Opsoclonus-myoclonus syndrome is typified by opsoclonus with myoclonus and ataxia, primarily associated with neuroblastoma. Brain stem cell and cerebellum dysfunction is thought to be due to an autoimmune mechanism. Following chemotherapy and selective neck dissection, the girl has had no recurrence or adverse sequelae. Ataxia disappeared during chemotherapy. We suggest that neuroblastoma should be considered in any child with unexpected by prolonged ataxia.
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PMID:[A case report on cervical neuroblastoma with ataxia]. 2170 71