Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0040822 (tremor)
18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Beta-N-methylamino-L-alanine (BMAA) and beta-N-oxalylamino-L-alanine (BOAA) are chemically related amino acids present in the seeds of Cycas circinalis and Lathyrus sativus, respectively. Consumption of these seeds has been linked to Guam amyotrophic lateral sclerosis (BMAA) and lathyrism (BOAA; a form of primary lateral sclerosis). A single large dose of BOAA or BMAA causes seizures in newborn mice and postsynaptic neuronal edema and degeneration in CNS explants. We report that the acute neurotoxic actions of these amino acids are blocked selectively by specific glutamate-receptor antagonists (administered intracerebroventricularly) (i.c.v.) prior to the amino acid. Administration of BOAA i.c.v. to neonatal mice (ED100 = 50 micrograms) elicits a spectrum of time-dependent behavioral states including arm and leg rigidity, convulsions, and resting tremor. These are blocked in a dose-dependent manner by cis-2,3-piperidine dicarboxylic acid (PDA), an antagonist of quisqualate (QA)-preferring (A2) and kainate (KA)-preferring (A3) glutamate receptors (ED50s; 2.8 micrograms, rigidity; 1.4 micrograms, convulsions; 2.4 micrograms, resting tremor). BMAA induces a transitory hyperexcitable state followed by a long-lasting whole-body shake/wobble (ED100 = 1,000 micrograms, i.c.v.). These responses are antagonized selectively and dose-dependently by 2-amino-7-phosphonoheptanoic acid (AP7), an N-methyl-D-aspartate (NMDA) or A1 glutamate-receptor antagonist (ED50 = 0.45 microgram). Taken collectively, our data indicate that the acute neuronotoxic actions of BOAA and BMAA (or a metabolite) operate through different glutamate-receptor species. BMAA likely exerts most of its action indirectly via the A1 glutamate receptor, while BOAA acts principally at the A2 and/or A3 receptor.
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PMID:Specific antagonism of behavioral action of "uncommon" amino acids linked to motor-system diseases. 314 80

To establish an advantageous method for the production of l-alanine, a procedure was studied for converting l-aspartic acid to l-alanine by microbial l-aspartic beta-decarboxylase. A number of organisms were screened to test their ability to form and accumulate alanine from aspartic acid. Pseudomonas dacunhae was selected as the most advantageous organism. With this organism, enzyme activity as high as 3,910 muliters of CO(2) per hr per ml of medium could be produced by shaking the culture at 30 C in the medium containing ammonium fumarate, sodium fumarate, corn steep liquor, peptone, and inorganic salts. For the enzymatic conversion of l-aspartic acid to l-alanine, the culture broth was employed as the enzyme source. A large amount of l-aspartic acid (as much as 40% of the broth) was converted stoichiometrically to alanine in 72 hr at 37 C. Furthermore, appropriate addition of a surface-active agent to the reaction mixture was found to be highly effective in shortening the time required for the conversion. Accumulated l-alanine was readily isolated in pure form by ordinary procedures with ion-exchange resins. Yields of isolated l-alanine of over 90% from l-aspartic acid were easily attainable.
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PMID:Enzymatic production of L-alanine by Pseudomonas dacunhae. 586 44

The formation of adenosine cyclic 3',5'-phosphate by Brevibacterium liquefaciens ATCC 14929 was studied with the use of nonproliferating cells and cell-free extract. With nonproliferating cells provided by deprivation of sulfate, the formation of this nucleotide was accelerated by adding some amino acids and sugars. Among amino acids tested, alanine and asparagine were most effective. Pentoses were more favorable than hexoses and other sugars. Formation of adenosine cyclic 3',5'-phosphate was observed also with chloramphenicol-treated cells. Experiments on cell-free extract showed that addition of alanine or pyruvate stimulated the formation of adenosine cyclic 3',5'-phosphate from adenosine-5'-triphosphate. When alanine was added to the cell-free system, shaking of the reaction mixture further increased the amount of the nucleotide, but pyruvate was far more effective than alanine. No synergistic effect of alanine and pyruvate was observed. Some enzyme activity was observed which decomposed adenosine cyclic 3',5'-phosphate, but it was weak as compared with adenyl cyclase activity in the presence of pyruvate. From the results obtained, it appears that pyruvate may act as an activating factor of adenyl cyclase in Brevibacterium liquefaciens.
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PMID:Formation of adenosine cyclic 3',5'-phosphate by nonproliferating cells and cell-free extract of Brevibacterium liquefaciens. 603 54

It has recently been demonstrated that human pancreatic GH-releasing factor (hpGRF-44) and Tyr-D-Trp-Ala-Trp-D-Phe-NH2 (subsequently referred to as 'the peptide') release GH from rat pituitary glands maintained in vitro and, in the former case, increase circulating GH in rats and man. The commercial importance of discovering an agent capable of specifically enhancing GH secretion in ruminants stimulated the present study which examined: the intravenous administration of both peptides on plasma GH, prolactin, insulin, glucose, urea and non-esterified fatty acids in goats and the effect of the peptide on the release of GH from sheep pituitary glands maintained in vitro. The peptide was injected into the jugular vein of goats in three different forms and at several concentrations (dispersal by shaking, 0.07 microgram/kg; 0.7 microgram/kg; ball-milled, 7.0 micrograms/kg, 70 micrograms/kg; dimethyl sulphoxide (5%), 7.0 micrograms/kg, 70 micrograms/kg). None of the treatments stimulated a significant increase in circulating GH. Nevertheless the peptide (20 micrograms/ml medium) was found to stimulate a 50-60% increase in the production of GH from sheep pituitary glands maintained in vitro. The effect of intravenously injecting hpGRF-44 (1.0 microgram/kg) was investigated in the present and absence of passive immunization with sheep anti-somatostatin immunoglobulin G (IgG) (a bolus of 600 mg, 3 h before treatment with hpGRF-44). Plasma GH was increased (P less than 0.001) within 15 min of treatment and the magnitude of the response was the same for both the immunized and non-immunized goats. A second peak was measured after approximately 75 min which was only significant (P less than 0.05) in the immunized group.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of intravenous administration of growth hormone-releasing factor (hpGRF-44) and Tyr-D-Trp-Ala-Trp-D-Phe-NH2 on plasma hormones and metabolites in goats. 643 24

L-beta-N-methylamino-L-alanine (L-BMAA, 500 micrograms) infusions into the lateral ventricle induced splay, clonic convulsions, and rigidity in about 60% of rats. Electroencephalograph (EEG) recording during clonic convulsions and rigidity demonstrated epileptiform discharges. Duration and severity of L-BMAA-induced clonic convulsions were reduced significantly by DNQX, a non-NMDA glutamate receptor antagonist, but not by AP-5, a NMDA receptor antagonist or MK-801, a noncompetitive NMDA antagonist. Latency of L-BMAA-induced clonic convulsions was significantly prolonged by DNQX, AP-5 and MK-801. L-BMAA-induced splay was not modified by DNQX or AP-5 but was slightly enhanced by MK-801. L-BMAA-induced rigidity was abolished by MK-801 and partially inhibited by DNQX and AP-5. The L-BMAA-induced behaviors of grooming, facial tremor, etc. were affected by DNQX, AP-5, and MK-801. Our results suggest that L-BMAA may induce behavioral changes by acting upon several subtypes of excitatory amino acid receptors.
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PMID:L-beta-methylamino-alanine-induced behavioral changes in rats. 809 28

Cucurbita maxima trypsin inhibitor I (CMTI-I), a member of the squash-type protease inhibitor family, is composed of 29 amino acids and shows strong inhibition of trypsin by its compact structure. To study the structure-function relationship of this inhibitor using protein engineering methods, we constructed an expression system for CMTI-I as a fused protein with porcine adenylate kinase (ADK). A Met residue was introduced into the junction of ADK and CMTI-I to cleave the fusion protein with CNBr, whereas a Met at position 8 of authentic CMTI-I was replaced by Leu. Escherichia coli JM109 transformed with the constructed plasmid expressed the fused protein as an inclusion body. After cleavage of the expressed protein with CNBr, fully reduced species of CMTI-I were purified by reversed-phase HPLC and then oxidized with air by shaking. For efficient refolding of CMTI-I, we used 50 mM NH4HCO3 (pH 7.8) containing 0.1% PEG 6000 at higher protein concentration. Strong inhibitory activity toward trypsin was detected only in the first of three HPLC peaks. The inhibitor constant of CMTI-I thus obtained, in which Met8 was replaced by Leu, was 1.4 x 10(-10) M. The effect of replacement of Met with Leu at position 8 was shown to be small by comparison of the inhibitor constant of authentic CMTI-III bearing Lys at position 9 (8.9 x 10(-11) M) with that of its mutant bearing Leu at position 8 and Lys at position 9 (1.8 x 10(-10) M). To investigate the role of the well conserved hydrophobic residues of CMTI-I in its interaction with trypsin, CMTI-I mutants in which one or all of the four hydrophobic residues were replaced by Ala were prepared. The inhibitor constants of these mutants indicated that those with single replacements were 5-40 times less effective as trypsin inhibitors and that the quadruple mutant was approximately 450 times less effective, suggesting that the hydrophobic residues in CMTI-I contribute to its tight binding with trypsin. However, each mutant was not converted to a temporary inhibitor.
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PMID:Synthesis of a squash-type protease inhibitor by gene engineering and effects of replacements of conserved hydrophobic amino acid residues on its inhibitory activity. 901 Sep 39

We evaluated the focal therapeutic effect of oily carcinostatic agents administered by transcatheter arterial infusion (TAI) as the initial therapy in patients with hepatocellular carcinoma in a randomized controlled clinical trial. Group A (19 patients) received 4 mg of styrene maleic acid neocarzinostatin in 4 ml of Lipiodol, and group B (18 patients) received 100 mg of epirubicin in 4 ml of Lipiodol via the tumor feeding arteries as peripherally as possible. The grade of Lipiodol accumulation and the tumor regression rate were determined 2 weeks after TAI by computerized tomography. Adverse effects within 2 weeks after TAI were evaluated by subjective signs and symptoms such as fever (maximum body temperature) and the frequency of shaking chills and abdominal pain, and by biochemical parameters such as albumin, prothrombin time, and aspartate and alanine aminotransferases. Lipiodol accumulation in the tumor was significantly greater in group A (12/19; 63.2% showing grade IV Lipiodol accumulation) than in group B (3/18; 16.7% showing grade IV) (P<0.05). The tumor regression rate was also significantly greater in group A (8/17; 47.1% showing more than 25% tumor regression) than in group B (1/13; 7.7% showing more than 25% tumor regression) (P<0.05). Although clinically significant elevations of aminotransferases and reductions of cholinesterase, and shaking chills were observed more often in group A than in group B (P<0.0001), these factors had little influence on the clinical outcome. Our results suggest that styrene maleic acid neocarzinostatin in Lipiodol exerts a more favorable focal therapeutic effect than does epirubicin in Lipiodol in the initial treatment of hepatocellular carcinoma.
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PMID:Focal therapeutic efficacy of transcatheter arterial infusion of styrene maleic acid neocarzinostatin for hepatocellular carcinoma. 1063 37

A 15-year-old boy with T-cell acute lymphoblastic leukemia (ALL) (FAB L1), diagnosed in 1995, received combination chemotherapy consisting of 6 weeks of induction (vincristine, epirubicin, L-asparaginase, prednisolone) and 2 weeks of consolidation (cytosine arabinosides, etoposide). After achieving remission, for further maintenance of remission, he was treated with 14 cycles of intensive chemotherapy consisting of 6-MP, 10 mg/kg orally on the first 4 days, and cyclophosphamide, 1200 mg/m2, vincristine, 1.5 mg/m2, epirubicin, 15 mg/m2, and cytosine arabinoside, 40 mg/m2, intravenously on days 4, 11, 39, and 40, respectively. On day 18 of each cycle, he received intravenous methotrexate (MTX) infusion in a total dose of 150 mg/m2 plus oral leucovorin (30 mg/m2 ) rescue 36 h after starting MTX therapy. In addition, oral trimethoprim-sulfamethoxazole was given regularly to prevent Pneumocystis carinii infection. The patient achieved remission during the first course of treatment, but 8 months later the disease relapsed. He then received four doses of MTX (800 mg intravenously) plus leucovorin rescue in the following 4 months. During the last MTX therapy, small hemorrhagic bullae were found on the lateral side of the right ankle, but subsided after a few days. Due to partial remission of the disease, he was admitted again in January 1999 for high-dose MTX therapy. An initial hemogram on admission revealed hemoglobin 7.2 g/dL, white cell count 15,200/mm3, platelet count 153/mm3, blood creatinine 0.5 mg/dL, and alanine leucine aminotransferase (ALT) 20 U/L. He received 8500 mg of MTX (5000 mg/m2 ) as a continuous intravenous infusion for 24 h. Thirty-six hours after the start of MTX infusion, leucovorin (30 mg, intravenous) rescue was initiated every 6 h for 3 days. Another preventive measure to cover MTX toxicity included aggressive intravenous fluid replacement (4 L/m2 /day) and the addition of 25 meq/L sodium bicarbonate to the intravenous fluid to alkalinize the urine. Concurrent medication included 6-MP (50 mg) once daily and trimethoprim-sulfamethoxazole (120 mg, 600 mg) twice daily every other day. Plasma MTX levels were 52.36 micromol/L 24 h after MTX infusion, 1.87 micromol/L after 48 h, 0.57 micromol/L after 72 h, and 0.41 micromol/L after 96 h. These indicated delayed MTX plasma clearance. The blood creatinine level was mildly elevated from 0.5 mg/dL to 0.7 mg/dL. Thirty-six hours after the administration of MTX, the patient developed an erythematous painful swelling on the right middle finger. The erythema, with subsequent large bulla formation, progressed to all the fingers, toes, palms, and the soles of the feet. Some erythematous to hemorrhagic papules also appeared on the bilateral elbows. Subsequently, diffuse tender erythema with extensive erosions and focal tiny pustules developed on the back, abdomen, proximal extremities, and face (Fig. 1a,b). A positive Nikolsky's sign was also present. A biopsy specimen of the right dorsal hand lesion revealed parakeratosis, detached acanthotic epidermis with scattered necrotic keratinocytes, dyskeratotic cells and nuclear atypia, neutrophilic exocytosis, and many neutrophils in the papillary dermis (Fig. 2). The skin condition deteriorated rapidly. Toxic epidermal necrolysis-like lesions involved 90% of the total body surface on the fifth day after MTX infusion. Mucositis, diarrhea, involuntary tremor, fever, and chills were noted. The patient was then sent to the burn unit for intensive skin care. Ten days after MTX therapy, profound agranulocytosis and thrombocytopenia (white cell count 100/mm3, platelets 14,000/mm3, and hemoglobin 5.6 g/dL) were found. The patient was then started on granulocyte colony stimulation factor (G-CSF, 5 microg/kg/day), but his general condition deteriorated rapidly and he died 6 days later due to septic shock and multiple organ failure.
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PMID:Toxic epidermal necrolysis following combination of methotrexate and trimethoprim-sulfamethoxazole. 1097 34

Environmental toxins have been implicated in the etiology of Parkinson's disease. Recent findings of defects in the ubiquitin-proteasome system in hereditary and sporadic forms of the illness suggest that environmental proteasome inhibitors are candidate PD-inducing toxins. Here, we systemically injected six doses of naturally occurring (epoxomicin) or synthetic (Z-lle-Glu(OtBu)-Ala-Leu-al [PSI]) proteasome inhibitors into adult rats over a period of 2 weeks. After a latency of 1 to 2 weeks, animals developed progressive parkinsonism with bradykinesia, rigidity, tremor, and an abnormal posture, which improved with apomorphine treatment. Positron emission tomography demonstrated reduced carbon-11-labeled 2beta-carbomethoxy-3beta-(4-fluorophenyl)tropane (CFT) binding to dopaminergic nerve terminals in the striatum, indicative of degeneration of the nigrostriatal pathway. Postmortem analyses showed striatal dopamine depletion and dopaminergic cell death with apoptosis and inflammation in the substantia nigra pars compacta. In addition, neurodegeneration occurred in the locus coeruleus, dorsal motor nucleus of the vagus, and the nucleus basalis of Meynert. At neurodegenerative sites, intracytoplasmic, eosinophilic, alpha-synuclein/ubiquitin-containing, inclusions resembling Lewy bodies were present in some of the remaining neurons. This animal model induced by proteasome inhibitors closely recapitulates key features of PD and may be valuable in studying etiopathogenic mechanisms and putative neuroprotective therapies for the illness.
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PMID:Systemic exposure to proteasome inhibitors causes a progressive model of Parkinson's disease. 1686 91

Recent studies suggest that high-affinity neuronal nicotinic acetylcholine receptors (nAChRs) containing alpha4 and beta2 subunits (alpha4beta2*) functionally interact with G-protein-coupled dopamine (DA) D(2) receptors in basal ganglia. We hypothesized that if a functional interaction between these receptors exists, then mice expressing an M2 point mutation (Leu9'Ala) rendering alpha4 nAChRs hypersensitive to ACh may exhibit altered sensitivity to a D(2)-receptor agonist. When challenged with the D(2)R agonist, quinpirole (0.5-10 mg/kg), Leu9'Ala mice, but not wild-type (WT) littermates, developed severe, reversible motor impairment characterized by rigidity, catalepsy, akinesia, and tremor. While striatal DA tissue content, baseline release, and quinpirole-induced DA depletion did not differ between Leu9'Ala and WT mice, quinpirole dramatically increased activity of cholinergic striatal interneurons only in mutant animals, as measured by increased c-Fos expression in choline acetyltransferase (ChAT)-positive interneurons. Highlighting the importance of the cholinergic system in this mouse model, inhibiting the effects of ACh by blocking muscarinic receptors, or by selectively activating hypersensitive nAChRs with nicotine, rescued motor symptoms. This novel mouse model mimics the imbalance between striatal DA/ACh function associated with severe motor impairment in disorders such as Parkinson's disease, and the data suggest that a D(2)R-alpha4*-nAChR functional interaction regulates cholinergic interneuron activity.
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PMID:Dopamine D2-receptor activation elicits akinesia, rigidity, catalepsy, and tremor in mice expressing hypersensitive {alpha}4 nicotinic receptors via a cholinergic-dependent mechanism. 1972 Jun 21


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