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)

Acrylamide, widely employed as a vinyl monomer in the polymer industry, is a potent neurotoxin to man and to animals. The cumulative effect of prolonged, low-level exposure to acrylamide monomer is the insidious development of a progressive peripheral neuropathy. Sensory symptoms begin in the hands and feet (numbness, pins and needles), certain reflexes are lost and, with severe exposure, muscle weakness and atrophy occur in the extremities. The peripheral neuropathy may be supplemented by symptoms indicative of central nervous system damage (ataxia, tremor, somnolence and mental changes). The neuropathologic basis for this clinical picture has been determined in cats. Here, chronic acrylamide intoxication produces selective peripheral and central nerve fiber degeneration. Degeneration first occurs in the extremities of long and large nerve fibers which later undergo a progressive, seriate proximal axonal degeneration known as dying-back. Especially vulnerable are sensory axons supplying Pacinian corpuscles and muscle spindles in the hindfoot toepads, while adjacent motor nerve axons die back later. Distal central nerve fiber degeneration is seen in the medulla and the cerebellum. The neurotoxic property of acrylamide is of practical concern in two areas. One major problem is the protection of factory workers engaged in the manufacture of acrylamide. A sensitive test of neurologic function in these individuals, i.e., touch sensation, based on the experimental observation of the exquisite vulnerability of Pacinian corpuscles in acrylamide intoxicated cats, is presently under consideration. The second area for concern is the exposure of the populace to minute amounts of neurotoxic acrylamide monomer which contaminate acrylamide polymers currently deployed in the environment. Federal restrictions on the maximum permitted exposure to acrylamide, based on a largely clinical study of acrylamide neurotoxicity conducted ten years ago, may require a re-evaluation in the light of recent advances which have pinpointed the initial sites of nerve fiber degeneration.
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PMID:Nervous system degeneration produced by acrylamide monomer. 17 76

The mutagenicity of acrylonitrile (vinyl cyanide, propenenitrile) has been demonstrated in the Ames Salmonella typhimurium/liver microsome assay system. Acrylonitrile, in the presence of a mouse liver homogenate produced mutations in the TA 1535, TA 1538 and TA 1978 strains. Exposure of the bacteria was achieved by spotting the acrylonitrile on a "lawn" of salmonella, by shaking a reaction mixture consisting of bacteria, liver homogenate and acrylonitrile, and by exposing the homogenate and bacteria to an atmosphere containing the acrylonitrile. Mutagenesis by this latter method was observed at exposures as low as 57 ppm, less than three times the TLV of 20 ppm that is designated in the United States.
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PMID:Mutagenic studies with acrylonitrile. 32 11

The crude ethanolic extract prepared from the stem bark of Solanum pseudo-quina produced excitatory effects dominated by convulsions in rats and mice. Solvent extraction followed by alumina column chromatography resulted in the isolation of a pharmacologically active material (AP) which was identified to be (25S)-isosolafloridine. The convulsions produced by AP were predominantly clonic and invariably preceded by generalized fine and coarse tremors. This convulsive behaviour did not entirely resemble the convulsions produced by strychnine, pentylenetetrazol, bicuculline, picrotoxin or 3-mercaptopropionic acid. The tremor and convulsions were only slightly affected by drugs interfering with cholinergic, catecholaminergic, serotoninergic or encephalinergic neurotransmission. Only diazepam and particularly gamma-vinyl-GABA blocked AP-induced effects. After section of the spinal cord at a mid-theoretic level, AP produced convulsions only in the anterior part of the body. After intracerebroventricular administration, AP produced only sedation. A depressive effect was also observed on the blood pressure of conscious rats before and after the convulsions. In subconvulsive doses AP enhanced spontaneous motor activity in mice.
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PMID:Convulsive action of (25S)-isosolafloridine isolated from Solanum pseudo-quina bark. 325 86

Intraperitoneal injection of ethanol (1-2 g/kg) and chlordiazepoxide (2-16 mg/kg) suppressed susceptibility to audiogenically induced, clonic-tonic seizures and antagonized forelimb tremor in rats undergoing ethanol withdrawal, 30 min after treatment. However, a smaller dose of ethanol (0.5 g/kg) actually increased clonic seizure frequency, suggesting that ethanol exerts a biphasic proconvulsant/anticonvulsant action. Direct activation of gamma-aminobutyric acid (GABA) receptors by intracisternal administration of GABA (100-1000 micrograms), muscimol (0.3-1.0 micrograms) or 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol (THIP) (0.3-3.0 micrograms) 5 to 10 min before testing also reduced susceptibility to audiogenic clonic-tonic seizures. In sharp contrast to these anticonvulsant actions, GABA, muscimol and THIP had no effect on withdrawal-induced forelimb tremors. Blockade of GABA uptake with 1-2,4-diaminobutyric acid (300 and 600 mg/kg i.p.) and inhibition of GABA transaminase with aminooxyacetic acid (12.5 and 25.0 mg/kg i.p.) both reduced susceptibility to seizures. However, anticonvulsant doses of these two drugs, unlike GABA, muscimol and THIP, also reduced forelimb tremor. Three other GABA transaminase inhibitors, gamma-vinyl GABA (450 and 900 mg/kg i.p.), gamma-acetylenic GABA (50-150 mg/kg i.p.) and ethanolamine-O-sulfate (250-750 mg/kg i.p.), were inactive against ethanol withdrawal audiogenic seizures and forelimb tremors. These results indicate that direct GABA receptor activation can selectively suppress one type of ethanol withdrawal response (i.e., audiogenic seizure susceptibility) while failing to influence another (forelimb tremors).
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PMID:Differential sensitivity of ethanol withdrawal signs in the rat to gamma-aminobutyric acid (GABA)mimetics: blockade of audiogenic seizures but not forelimb tremors. 631 80

Wet-dog-shaking resembling morphine withdrawal behaviour can be evoked in rats by administration of dipropylacetate (DPA). It has been postulated that DPA elicits the withdrawal like behaviour through specifically inhibiting the GABA-degradation in nerve terminals. Inhibition of GABA-transaminase (GABA-T) by aminooxyacetic acid (AOAA) in other compartments of the brain would result in an inhibition of the stimulated GABA-release via feedback on autoreceptors and therefore suppress the DPA-evoked behaviour. This hypothesis has been tested using the GABA-T inhibitors gamma-acetylenic-GABA (GAG), gamma-vinyl-GABA (GVG) and ethanolamine-O-sulphate (EOS). Although GAG and AOAA were found to suppress the body shakes, both GVG and EOS had no effect. Both GAG and AOAA have possibly also effect on glutamate decarboxylase (GAD) whereas GVG and EOS did not affect this enzyme, suggesting a nerve terminal-specific effect on DPA-induced behaviour. GVG stimulated DPA-evoked body shakes after 36 and 60 h, when a specific GABA-increase in nerve terminals will be present.
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PMID:Quasi-morphine withdrawal behaviour: indication for a specific involvement of the GABA-ergic nerve terminal compartment. 642 Jun 29

The adhesion and growth of two pathogenic bacteria (Escherichia coli and Staphylococcus aureus) on the surface of a heparinized hydrophilic polymer were studied. Heparinized hydrophilic polymer is composed of poly(vinyl chloride) grafted with poly(ethylene glycol) monomethacrylate, diethylaminoethyl methacrylate, and ionically bound heparin. Poly(vinyl chloride) was used as a control. Plasma protein pre coated polymers were also prepared to evaluate the effect of proteins on bacterial adhesion. Polymer films were stored in bacterial suspensions under gentle shaking at 37 degrees C for 24 hr. The amount of adherent bacterial cells was measured by the bioluminescent assay of bacterial adenosine triphosphate. Their structure was observed by use of a scanning electron microscope. These evaluations demonstrated that a large amount of bacterial adhesion and biofilm formation was found on the surface of poly(vinyl chloride), whereas significant reductions in bacterial adhesion and no biofilm formation were observed on heparinized hydrophilic polymer. Bacterial adhesion onto plasma protein pre coat polymer films were also investigated, and it was clear that the bacterial adhesion on these surfaces was dependent upon the amount and species of absorbed proteins.
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PMID:Inhibition of bacterial adhesion and biofilm formation by a heparinized hydrophilic polymer. 857 26

The microbial oxidation of ebastine to carebastine was investigated. Among the 15 micro-organisms examined, only the Cunninghamella strains showed the desired biotransformation. Cunninghamella blakesleeana oxidised the substrate within 7 days, via the intermediates alcohol and aldehyde, mainly to carebastine, the corresponding carboxylic acid. Optimisation of the culture conditions increased the yield from initially 10% up to a reproducible 40%. For the synthesis of carebastine a substrate concentration of 200 mg/l, a starting pH of 5.0 and the addition of 1% poly(vinyl alcohol) is favourable. The results achieved in experiments with shaking flasks are transferable to the fermentation scale and yielded 270 mg carebastine in a 3-1 fermentation of 600 mg ebastine. The progress of the reaction was detected by TLC and HPLC, the products were identified by mass spectrometry and NMR.
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PMID:Microbial oxidation of ebastine. 886 30

The effects of the administration of two doses (1,000 and 1,500 mg kg-1) of gamma-vinyl-GABA (GVG), have been tested in pubescent rats, systemically injected with kainic acid (KA). The changes in spontaneous behaviour before KA injection, the behavioural and epileptic manifestations (Wet Dog Shakes, Limbic Seizures and Status Epilepticus) and the lethality rate caused by KA were taken into account and compared to those observed in controls and in carbamazepine (CBZ) or phenytoin (PHT) treated animals. While GVG appeared to reduce the incidence of the epileptic manifestations and the subsequent mortality, particularly when higher doses of the drug were used, CBZ exerted a proconvulsant action and PHT did not substantially modify the parameters considered. Moreover, GVG, but not CBZ and PHT, induced remarkable sedative effects which disappeared within 48 h. The different anticonvulsant profile of GVG, CBZ and PHT were correlated to their different modes of action, since GVG acts by enhancing the inhibitory GABA-mediated processes, while CBZ and PHT act by reducing the excitatory processes.
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PMID:Vigabatrin versus carbamazepine and phenytoin in kainic acid-treated pubescent rats. 934 35

The aim of this study is to clarify the physico-chemical factors which influence apatite formation on/in a hydrogel during a novel alternate soaking process. A poly(vinyl alcohol) (PVA) gel was used as a model matrix. The amount of apatite formed on/in PVA gels decreased with an increase in the reaction temperature during the same reaction cycles. This suggested that the equilibrium swelling ratios decreased with increasing reaction temperatures; that is, the diffusion of calcium and phosphate ions reduced at high reaction temperature. However, the crystallinity of apatite formed on/in PVA gels was greater at higher reaction temperatures. The amount of apatite formed on/in PVA gels increased with an increase in the calcium and phosphate solution concentrations, and increased by shaking at the first three reaction cycles. A few influences could be observed when the solution volume was changed, however, the soaking order was not effective in this study. These results indicate that the amount of apatite formation on/in PVA gels can be controlled by changing the reaction temperature and the Ca- and P-solution concentrations, and that the crystallinity of apatite can be also changed by controlling the reaction temperatures.
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PMID:Apatite formation on/in hydrogel matrices using an alternate soaking process (III): effect of physico-chemical factors on apatite formation on/in poly(vinyl alcohol) hydrogel matrices. 1048 15

An RFB (radial-flow bioreactor) with a reactor volume of 5 ml was applied to produce human beta3GnT (beta1,3-N-acetylglucosaminyltransferase) using two stably transformed insect cell lines. When air was supplied to the RFB, cell growth stopped at 4 days of culture and beta3GnT was not detected. However, with a supply of pure oxygen, the cell concentration, assumed from glucose consumption, increased by 1.3x10(7) cells/ml. Insect cells attached to poly(vinyl alcohol) matrixes packed in the RFB and grew confluently; 5.6 m-units/ml beta3GnT was produced under the conditions of pure oxygen supply and addition of glucose and glutamine. This RFB was first applied in beta3GnT production using stably transformed insect cells. The amount of beta3GnT production in only a 5 ml-scale RFB was comparable with that of a 100 ml shaking flask culture.
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PMID:Application of a radial-flow bioreactor in the production of beta1,3-N-acetylglucosaminyltransferase-2 fused with GFPuv using stably transformed insect cell lines. 1563 81


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