Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The dog with an end-to-side portacaval shunt (PCS) has been extensively used as a model to investigate hepatic encephalopathy (HE) as it demonstrates a plasma amino acid pattern similar to patients with chronic liver disease. In adult mongrel dogs, the effect of PCS on plasma and CSF amino acids, octopamine (OCT), phenylethanolamine (PEA) and CSF 5-hydroxyindolacetic acid (5-HIAA), were studied. Moreover, the effect of correction of plasma amino acids by infusional techniques was investigated.Tyrosine, tryptophan and phenylalanine levels increased dramatically during the development of HE in plasma and CSF, while valine, leucine and isoleucine decreased in plasma only, but CSF levels remained stable. Plasma and CSF octopamine and phenylethanolamine and CSF 5-HIAA increased markedly as clinical features in the dogs' behavior, characteristic of hepatic encephalopathy occurred, including hypersalivation, ataxia, flapping tremor, somnolence and finally coma. Once in coma, the dogs were infused with an amino acid mixture (F080) calculated to normalize the plasma amino acid pattern. After one to eight hours, the dogs began to awake. Simultaneously, blood, and CSF aromatic amino acids returned to their control values, as did OCT, PEA and CSF 5-HIAA. If F080 infusion was stopped, biochemical alterations would appear within one week, again accompanied by clinical hepatic encephalopathy.The results indicate that the altered levels of aromatic and branched chain amino acids, octopamine and PEA in plasma and CSF correlate well with the development of HE and that correction of the plasma amino acid abnormalities improves encephalopathy simultaneously with correction of neurotransmitter derangements in CSF.
 ...
PMID:Alterations in plasma and CSF amino acids, amines and metabolites in hepatic coma. 63 94

Acivicin is an investigational amino acid antitumor antibiotic currently being evaluated in Phase II clinical trials. In humans acivicin causes reversible, dose-limiting central nervous system (CNS) effects including somnolence, ataxia, personality changes, and hallucinations. We have observed and reported previously that acivicin-treated cats exhibit symptoms (ataxia, sedation, somnolence) resembling CNS toxicity reported in humans. We hypothesized that if acivicin uptake into brain were mediated by a saturable transport system common to endogenous amino acids, drug uptake and CNS toxicity might be blocked by elevation of normal amino acid concentrations in circulating plasma. To test this hypothesis, cats received constant-rate i.v. infusions of either saline or Aminosyn, 10% (a commercially available mixture of 16 amino acids not containing glutamine, glutamate, aspartate, or cysteine) for 4 h prior to and 18 h subsequent to administration of acivicin at a dose producing marked behavioral changes in control cats. Presence or absence of ataxia and sedation were noted at intervals after acivicin treatment. Results showed that Aminosyn infusion prevented CNS symptoms in six of eight cats. Subsequent experiments showed that acivicin levels in brain tissue of Aminosyn-treated cats were 13% of the drug levels in saline-infused cats. Acivicin levels in most peripheral tissues were also decreased significantly by Aminosyn infusion but not to the extent observed in brain. Decreased brain uptake was shown to be due to a combination of amino acid blockade of drug transport into that organ and of increased total body clearance of drug. Concomitant Aminosyn treatment did not alter the efficacy of acivicin in mice bearing L1210 leukemia or MX-1 human mammary carcinoma. Further studies demonstrated that a solution containing only four large neutral amino acids (leucine, isoleucine, phenylalanine, and valine) could also protect cats from acivicin-induced CNS toxicity, apparently without increasing acivicin total body clearance. However, a mixture of several other amino acids contained in Aminosyn (alanine, arginine, tyrosine, histidine, proline, serine, and glycine) failed to prevent CNS toxicity. We conclude that cotreatment with Aminosyn or a mixture of large neutral amino acids could protect cancer patients from acivicin-induced CNS toxicity without ablating antitumor efficacy.
 ...
PMID:Prevention of central nervous system toxicity of the antitumor antibiotic acivicin by concomitant infusion of an amino acid mixture. 238 52

Heterozygotes of autosomal-recessive diseases can often be recognized by special heterozygote tests, since enzyme activities are normally reduced in comparison with the normal homozygote state. In Drosophila, the majority of recessive lethal mutations shows a reduction of fitness in heterozygotes, whereas in a strong minority fitness of heterozygotes is increased. This review will be devoted to a consideration of the extent to which heterozygotes for a wide variety of nominally recessive diseases are subject either to an increased liability for common diseases or slight shifts of behavioral characteristics. The available evidence has been collected and will be discussed in three steps: Most studies are available for phenylketonuria. For this group of diseases, a slight reduction of average--especially verbal--I.Q. in heterozygotes has been reported together with signs of a slightly increased cerebral irritability, a possible slight increase of risk for mental disease, and an increase of blood phenylalanine levels in stress situations. The PKU example is used to discuss methodological problems involved in such studies. Other conditions for which relevant deviations in heterozygotes are possible or even likely include among others lipid storage diseases, microcephaly, myoclonus epilepsy, Wilson's disease, galaktokinase deficiency, homocystinuria, recessive myotonia and ataxia- teleangiectasia (increased cancer risk). Since heterozygotes for autosomal recessive diseases are common, it is possible that an appreciable fraction of "multifactorial" genetic liabilities for common, "constitutional" or mental disease might simply be due to heterozygosity for genes whose homozygous affects are already well known. By the same token, much of the "normal" genetic variability influencing cognitive performance (I.Q.)--especially in the lower range--and personality characteristics could also be caused by recessive genes in the heterozygous state.
 ...
PMID:Clinical consequences of heterozygosity for autosomal-recessive diseases. 637 70

A 10-year-old boy with palmoplantar hyperkeratosis and keratitis was reported. His physical development was normal and mental development was lower limit. He had also convulsions with low grade fever several times, and his EEG showed paroxysmal discharges. The plasma levels of phenylalanine and tyrosine were 5 to 10 times higher than those of controls. Tyrosinemia II was diagnosed on the low level of cytosol tyrosine aminotransferase in biopsied liver. The cases of tyrosinemia II were reviewed on the symptoms of the central nervous system. Two of twelve cases had convulsions. Adult cases demonstrated nystagmus, tremor, ataxia, and convulsion. Hyperkeratosis and corneal lesions were characteristic in symptoms of tyrosinemia II, but attention should be paid to the symptoms of the central nervous system.
 ...
PMID:[A case of tyrosinemia type II with convulsion and EEG abnormality]. 826 Feb 11

There have been several reports describing that immunoadsorption therapy improves the neurologic involvement in Fisher's syndrome (FS). However, few studies have assessed the usefulness of immunoadsorption therapy in view of the removal ability of anti-GQ(1b) antibody, which may function the development of FS. We examined the ability of immunoadsorbents for the anti-GQ(1b) antibody in a patient with FS. A 28-year-old woman developed diplopia and giddiness following a cough, fever and diarrhea. On admission (day 22), neurologic examination showed bilateral moderate oculomotor paralysis and bilateral complete abducens paralysis. She had areflexia, numbness of middle and ring fingers on the left and mild ataxic gait. Her serum had IgG anti-GQ(1b) and anti-GD(1b) antibodies. We examined the absorption of anti-ganglioside antibodies onto a polyvinyl alcohol gel (PVA), a phenylalanine-linked PVA (PH-350) and a tryptophan-linked PVA (TR-350) by the batchwise adsorption method. TR-350 absorbed the autoantibodies, but the removal ability of autoantibody by PVA and PH-350 was not proved. The FS patient was treated with TR-350 (days 29, 34 and 43) and PH-350 (day 39). Anti-GQ(1b) and anti-GD(1b) antibodies were significantly removed by the TR-350, in accordance with the results of the in vivo study. There was little loss of albumin as compared with the immunoglobulins and complements. The numbness and ataxia disappeared on day 44. The diplopia disappeared on day 106. TR-350 would be better than PH-350 in the treatment of FS by immunoadsorption therapy.
 ...
PMID:[Immunoadsorption therapy on Fisher's syndrome--removal ability of anti-ganglioside antibodies by tryptophan-linked immunoadsorbent]. 866 31

The beneficial effect of plasma exchange, plasmapheresis or immunoadsorption therapy on Fisher's syndrome, suggested previously, has not been proved since no controlled studies have been conducted. In order to assess the effect of any treatment on Fisher's syndrome, simple and reasonable grading scales for evaluating the major neurological signs are needed. We tried immunoadsorption therapy in four patients with Fisher's syndrome, whose sera had anti-GQ1b antibodies. The clinical course was observed, with assessment of the severity of the major neurological signs based on grading scores; ranging from 0 to 30 for external ophthalmoplegia, from 0 to 10 for ataxia, and from 0 to 16 for areflexia. Tryptophan- or phenylalanine-linked polyvinyl alcohol gel column (TR-350, PH-350) was used as an adsorbent. In a patient who had IgG anti-GQ1b antibody and another patient who had both IgG and IgM anti-GQ1b antibodies, we compared the effectiveness of TR-350 and PH-350 to remove the anti-GQ1b antibody during the therapy. Two patients underwent immunoadsorption therapy at the height of clinical manifestations: in one patient, the therapy was discontinued because of critical hypotension and arrhythmia; the other was given only three sessions of therapy. The other two patients received six or seven sessions during the early recovering stage. All patients recovered without major neurological sequelae. Since ataxia was improved earlier than external ophthalmoplegia, the duration of hospitalization and the time of return to social life depended upon the recovery of external ophthalmoplegia. Analysis of the time course of external ophthalmoplegia score indicated that the improving period and the 50%-recovery day came earlier in the patients who were given a sufficient number of sessions than those who received an insufficient number of sessions. The treatment with TR-350 reduced the IgG anti-GQ1b antibody titer more than that with PH-350, but reduced the IgM anti-GQ1b antibody titer similarly. Immunoadsorption therapy using TR-350 has a probable beneficial effect on Fisher's syndrome even though it is carried out after the height of illness. The evaluation method for the severity of external ophthalmoplegia that we used in the present study is useful for assessing the effect of therapy on Fisher's syndrome.
 ...
PMID:[Immunoadsorption therapy for Fisher's syndrome: analysis of the recovery process of external ophthalmoplegia and the removal ability of anti-GQ1b antibodies]. 881 Aug 48

Familial hemiplegic migraine, episodic ataxia type 2 (EA2), and spinocerebellar ataxia type 6 are allelic disorders of the CACNA1A gene (coding for the alpha(1A) subunit of P/Q calcium channels), usually associated with different types of mutations (missense, protein truncating, and expansion, respectively). However, the finding of expansion and missense mutations in patients with EA2 has blurred this genotype-phenotype correlation. We report the first functional analysis of a new missense mutation, associated with an EA2 phenotype-that is, T-->C transition of nt 4747 in exon 28, predicted to change a highly conserved phenylalanine residue to a serine at codon 1491, located in the putative transmembrane segment S6 of domain III. Patch-clamp recording in HEK 293 cells, coexpressing the mutagenized human alpha(1A-2) subunit, together with human beta(4) and alpha(2)delta subunits, showed that channel activity was completely abolished, although the mutated protein is expressed in the cell. These results indicate that a complete loss of P/Q channel function is the mechanism underlying EA2, whether due to truncating or to missense mutations.
 ...
PMID:Complete loss of P/Q calcium channel activity caused by a CACNA1A missense mutation carried by patients with episodic ataxia type 2. 1117 22

The CHK2 gene encodes a protein kinase that is important for the regulation of cell cycle arrest after DNA damage. CHK2 acts downstream of ataxia teleangiecstasia mutated (ATM), modulates the function of p53 and may help mediate cell cycle arrest at G2/M by phosphorylation of Cdc25C. Recently, the human homolog of the checkpoint kinase Cds1 (CHK2) has been suggested to be a tumor suppressor gene. Heterozygous germline mutations have been reported in Li-Fraumeni syndrome (LFS), a highly penetrant familial cancer phenotype, and in sporadic colon cancer. LFS is associated with the development of lymphoid malignancies, especially childhood ALL. Therefore, we analyzed the DNA from 143 lymphoid malignancies to determine whether they had mutations of the CHK2 gene. The 14 exons of CHK2 were studied by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) and sequencing of aberrantly migrating bands. One missense mutation changing serine to phenylalanine (codon 428) in an evolutionarily highly conserved domain was found in a non-Hodgkin's aggressive lymphoma. Another point mutation in the non-coding region was identified in one of adult T-cell leukemias (ATL) samples. This result suggests that mutation of the CHK2 gene may rarely be involved in the development of selected lymphomas.
 ...
PMID:Analysis of the CHK2 gene in lymphoid malignancies. 1169 18

Hereditary spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders for which >/=14 different genetic loci have been identified. In some SCA types, expanded tri- or pentanucleotide repeats have been identified, and the length of these expansions correlates with the age at onset and with the severity of the clinical phenotype. In several other SCA types, no genetic defect has yet been identified. We describe a large, three-generation family with early-onset tremor, dyskinesia, and slowly progressive cerebellar ataxia, not associated with any of the known SCA loci, and a mutation in the fibroblast growth factor 14 (FGF14) gene on chromosome 13q34. Our observations are in accordance with the occurrence of ataxia and paroxysmal dyskinesia in Fgf14-knockout mice. As indicated by protein modeling, the amino acid change from phenylalanine to serine at position 145 is predicted to reduce the stability of the protein. The present FGF14 mutation represents a novel gene defect involved in the neurodegeneration of cerebellum and basal ganglia.
 ...
PMID:A mutation in the fibroblast growth factor 14 gene is associated with autosomal dominant cerebellar ataxia [corrected]. 1248 43

We report our observations in an Australian family with spinocerebellar ataxia type 14 (SCA 14). We describe a novel mutation in exon 5 of the PRKCG gene, altering a highly conserved cysteine to a phenylalanine at codon 150, and record the detailed clinical observations in six affected family members.
 ...
PMID:Spinocerebellar ataxia type 14: study of a family with an exon 5 mutation in the PRKCG gene. 1629 2


1 2 3 Next >>