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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Utilizing a variation of the Fink-Heimer method, we examined the extent and location of axonal and terminal degeneration within the chicken cervical spinal cord, brainstem and cerebellum resulting from a single subcutaneous dose of bis(1-methylethyl)phosphorofluoridate (DFP). The effects of DFP on the activities of whole-brain neuropathy target esterase (NTE) and cholinesterase (ChE) were also assessed as were the development and severity of clinical signs characteristic of organophosphorus-induced delayed neuropathy (OPIDN). Both whole brain NTE and ChE activities were maximally inhibited during the first 24 h post-exposure, showing gradual recovery over a period of 3 weeks. OPIDN clinical signs were not observed at 7 days post-DFP but progressed to severe ataxia by day 14 and paralysis by day 21. There was a relative absence of degeneration at 7 days, a dramatic increase in degeneration density at 14 days, and high density degeneration at both 21 and 28 days. Cervical spinal and medullary tracts containing axonal degeneration included the fasciculus gracilis, dorsal and ventral spinocerebellar tracts, spinal lemniscus, and the intramedullary portions of the glossopharyngeal and vagus nerves. Brainstem nuclei containing terminal degeneration included the lateral cervical, gracile-cuneate, external cuneate, and inferior olivary nuclei, the nucleus tractus solitarius, and the lateral and paragigantocellular lateral reticular nuclei. Mossy fiber degeneration was also present in cerebellar folia I-Vb. These results show that exposure to DFP causes axonal and terminal degeneration in ascending spinal tracts, brainstem nuclei and cerebellar folia associated with the transmission of somatic and visceral sensory information.
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PMID:Selective axonal and terminal degeneration in the chicken brainstem and cerebellum following exposure to bis(1-methylethyl)phosphorofluoridate (DFP). 239 6

Chick embryos were injected on incubation Day 14 with 62 microliter of triorthocresyl phosphate (TOCP)/kg egg. Muscles of the leg were examined from 5 to 25 days after hatching. The sartorius from the thigh and the external gastrocnemius and peroneus longus from the tibial leg region were compared for muscle fiber size and end-plate length over this period. Treated chicks showed no acute toxic effects or overt ataxia and were equal in body weight to controls. At 5, 15, and 25 days after hatching, morphologic alterations consistent with denervation were detected. Muscle fibers were smaller than controls on Day 5 and were hypertrophic on Days 15 and 25. On Day 5 growth of fibers was retarded, an effect consistent with denervation, and the subsequent hypertrophy is predicted as compensation for denervated fibers. Small end plates were seen on Day 15, characteristic of end plates that were delayed in development by denervation. Each of these differences was greater in the tibial muscles than in the more proximally located sartorius. This is consistent with a distal neuropathy, such as that caused by TOCP in adult hens. Some recovery was apparent at the low dose 25 days after hatching. It is suggested that this resulted from reinnervation by repaired axons. This study of the myoneural apparatus and muscle fiber response to TOCP adds evidence to the possibility that the developing chick embryo may develop delayed neuropathy from organophosphorus compounds which produce this effect in adult hens.
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PMID:Morphologic alterations in leg muscles of chicks treated with triorthocresyl phosphate in ovo. 241 88

The susceptibility of wild mallard ducklings to the delayed neurotoxic effect of the neurotoxic organophosphorus insecticides cyanofenphos and leptophos was evaluated following a daily dosing regimen. Ducklings were treated daily with either cyanofenphos or with leptophos at different dose levels for 90 days, or until they died, or became paralyzed. A control group of ducklings given corn oil at 1 ml/kg daily for 90 days was used for comparison. All treated birds were observed daily for any clinical signs of neurotoxicity during the course of this study. All of the surviving ducklings that were treated with cyanofenphos at 4 mg/kg/day or leptophos at 10 mg/kg/day developed clinical signs of delayed neurotoxicity after 7 to 11 weeks of intoxication. Symptoms included leg weakness, ataxia, severe ataxia and paralysis. The observed clinical signs were confirmed by histological changes found in the spinal cords of the treated birds. These changes were of the type associated with organophosphorus-induced delayed neuropathy (OPIDN). These results demonstrate that wild mallard ducklings are susceptible to OPIDN and this avian species can be used in screening organophosphorus compounds for such effect.
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PMID:Delayed neurotoxicity in the wild mallard duckling caused by the organophosphorus insecticides cyanofenphos and leptophos. 243 7

An equimolal single dose (1 mmole/kg) of leptophos or cyanofenphos was given orally to chickens to assay the clinical and biochemical neurotoxic effects of these two organophosphorus insecticides. Parathion and TOCP at 2 and 1000 mg/kg of chicken body weight were tested in the same manner as negative and positive neurotoxicants, respectively. Three birds of each of five groups tested were sacrificed 1,2,3,7,14,21 and 28 days after treatment and the brains were taken for the biochemical tests. Acetylcholinesterase (AChE) and neurotoxic esterase (NTE) activities were determined in the brain microsomal fractions. In addition, the AChE activity in the brain soluble fractions was measured. Clinical observations indicated that leptophos-, cyanofenphos- and parathion-treated chickens became acutely poisoned but recovered from the typical cholinergic signs in a day or two. However, about 10 to 15 days later leptophos- and cyanofenphos-treated chickens developed the characteristic leg weakness and unrecoverable ataxia seen in birds given TOCP. The biochemical results indicated that cyanofenphos followed by leptophos and parathion produced more in vivo AChE inhibition than that produced by TOCP in both chicken brain soluble and microsomal fractions. Results suggested that there are no correlations between the in vivo effect of TOCP, leptophos and cyanofenphos on AChE and phenyl valerate-total hydrolyzing activities and the ability of these chemicals to produce neuropathy in hens. The results obtained from this study of the in vivo effect of the tested compounds on chicken brain NTE activity present an acceptable correlation between the inhibition of this enzyme and the ability of these chemicals to induce neuropathy. The mechanism and explanation for this correlation are presented. The in vivo effect of the tested compounds on the chicken brain NTE activity was determined using the indirect and a new direct method. The data presented in this report suggested that the new direct technique of assaying NTE activity using 4-nitrophenyl valerate (4-NPV) as substrate, can be useful in the in vivo screening studies of organophosphates for their ability to induce neuropathy in hens.
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PMID:In vivo inhibition of chicken brain acetylcholinesterase and neurotoxic esterase in relation to the delayed neurotoxicity of leptophos and cyanofenphos. 243 15

A multicentric study of 15 cases of Rett syndrome selected with the diagnostic criteria according HAG-BERG et al: female sex, normal pre and perinatal period, normal psychomotor development through the first months of life, early dementia between 1-3 years of age with autistic behaviour, loss of acquired purposeful hand skill, "washing hands" stereotypies, normal head circumference at birth with later deceleration of head growth and truncal ataxia with gait apraxia. Waking EEG showed unspecific abnormalities while sleep recording demonstrated extremely frequent multifocal spike and sharp waves mainly over the rolandic region and generalized, and also pseudo-periodic suppression of background activity. In 3 cases the EMG showed a peripheral axonal neuropathy. Only in one case we found hyperammonemia. Karyotypic studies performed in 12 cases demonstrated non specific fragile sites. CT scan was normal in almost all cases. The QD was extremely low.
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PMID:[Rett's syndrome: study of 15 cases]. 245 8

The repeated intravenous injections (RIVInj) of 5 mg/kg/day leptophos [O-(4-bromo-2, 5-dichlorophenyl) O-methyl phenylphosphonothioate] for 3 consecutive days caused delayed ataxia in 4 out of 9 hens (44.4%). And one out of 9 hens (11.1%) given RIVInj of 3 mg/kg leptophos for 5 days was affected with ataxia. Twenty hens, however, which received a single intravenous injection (SIVInj) of 15 mg/kg leptophos did not exhibit any delayed neuropathic signs at all. Thus, delayed neurotoxicity was increased by the subdividing RIVInj of the critical dose which was shown in the SIVInj of leptophos. The leptophos concentration in plasma and liver decreased very rapidly after finish of either SIVInj or RIVInj. Although no significant differences were observed in the biological half life of leptophos in plasma by different dosages, the mean level of leptophos decreased significantly with frequency of injections. On the contrary, the evident accumulation of leptophos was observed in only sciatic nerve with RIVInj. Leg muscle maintained relatively high level of leptophos after the last injection. These results suggest that leptophos seems to transfer from blood to affinitive tissues such as sciatic nerve or leg muscles and to accumulate there easily in initial stage after repeated iv injections, and that this causes the enhancement of neuropathy with repeated administrations of divided critical dose of leptophos in both iv and oral administration.
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PMID:Delayed neurotoxicity and toxicokinetics of leptophos in hens given repeatedly by low-dose intravenous injections. 247 90

Only a few cases of carcinomatous neuropathy with tonic pupils have been reported. In the present paper we described a 53-year-old woman with subacute sensory neuropathy who had presented with bilateral tonic pupils. She noticed numbness over the medial aspect of the left thigh in March, 1988, and then developed dysesthesia over the left forearm and hand, mild weakness of left upper and lower extremities and urinary disturbance. Neurological symptoms were subacutely progressive and she was bed-ridden in May. She was admitted to our hospital in June, 1988. On examination, she had body-weight loss of 6 kg during the last six months and general status was otherwise unremarkable. She had anisocoria; the left pupil was larger in daylight than the right, while smaller in dim light. The left pupil scarcely reacted to light, but promptly constricted to near vision. The right pupil constricted normally to light and near vision. An instillation of 0.0625% pilocarpine solution showed supersensitive response of both pupils. An instillation of 1.25% epinephrine solution demonstrated mild dilation of both pupils. Thus, it was conceivable that she had postganglionic ciliary nerve damage characteristic of tonic pupil as well as the lesion of sympathetic nerve innervating pupillary dilator. She had severe sensory ataxia and pseudoathetosis of the hands. Weakness was mild to moderate in extremities. Almost all deep tendon reflexes were absent. All modalities of sensation, particularly on deep sense, were severely involved with sea-level-type distribution below Th7, and over C2 to C3 regions on the left side.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Subacute sensory neuropathy manifestated by tonic pupils associated with small cell carcinoma of the lung]. 255 97

Verapamil, a calcium channel blocker, was administered to adult white leghorn hens to determine if inhibition of calcium entry could alter delayed neuropathy induced by administration of phenyl saligenin phosphate (PSP). Verapamil was given im in doses of 7 mg/kg/day for 4 days beginning 24 hr before administration of PSP (2.5 mg/kg im). Ataxia was less pronounced in hens given PSP plus verapamil than in hens given PSP alone during observations made 8-28 days after PSP administration. Myelinated fiber lesions were less extensive and regeneration more notable in the biventer cervicis nerve in chickens given PSP plus verapamil, with samples obtained both 17 and 28 days after PSP. In the absence of verapamil, rheobase and chronaxie values of strength-duration curves were higher and shorter, respectively, and sensitivity to acetylcholine was increased in biventer cervicis nerve-muscle preparations from hens given PSP. Verapamil did not alter PSP-induced inhibition of neurotoxic esterase, indicating that the mechanism involved in amelioration of these indices of delayed neuropathy was not associated with initial enzyme inhibition caused by this organophosphorus ester.
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PMID:Effect of verapamil on organophosphorus-induced delayed neuropathy in hens. 255 27

Sural nerve biopsy was done 7 cases of cancer patients associated with peripheral neuropathy. There were 3 cases of lung carcinoma and one each of pancreas adenoma, seminoma, sigmoid carcinoma and chondrosarcoma of the femur. The neurological features manifested themselves with sensory pattern of neuropathy associated with ataxia in one case, sensorimotor neuropathy in 3 cases, and idiopathic polyneuropathy, peripheral neuropathy with proximal myopathy and neuropathy with paraneoplastic cerebellar syndrome each in one case, 6 patients showed neuropathy before malignancy was discovered and only one patient had neuropathy after the onset of carcinoma. Sural nerve biopsy studied in all the 7 patients with light and electron microscope revealed no infiltration of carcinomatous cells in the sural nerve fascicles. There was severe loss of myelinated fibers and severely axonal degeneration in one patient. Another patient showed segmental demyelination (5.03 x 10(3)/mm2). There was evidence of both axonal degeneration and demyelination associated with moderate reduction in the number of the myelinated fiber density ranging from 1.02 to 4.35 x 10(3)/mm2. In 6 cases, mononuclear cells were seen in nerve fascicles under the electron microscope. The characteristic pathological findings, their relation with the duration and onset of the cancer and some ideas regarding the pathogenesis are discussed.
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PMID:[Carcinomatous neuropathy: clinical and pathologic findings of sural nerve biopsy in 7 cases]. 255 34

Attention has recently been directed toward patients having a polyneuropathy and a monoclonal IgM anti-myelin-associated glycoprotein (anti-MAG) antibody. The possibility of a pathogenetic role for the anti-MAG antibody in the evolution of the polyneuropathy and in the development of central nervous system signs, including tremor and ataxia, remains unresolved. In 5 patients with this syndrome whose clinical courses were followed closely, in 1 of whom a complete postmortem examination of the nervous system was performed, we made the following observations: the anti-MAG antibody did not localize to the compact layer of the myelin sheath in affected nerves, but did localize to areas of myelin splitting; anti-MAG antibody present in the sural nerve of an affected individual for 7 years was not associated with progressive pathology; anti-MAG antibody was not deposited in the central nervous system of an affected individual, although the antibody did bind to these same tissues in vitro; deposition of anti-MAG antibody observed at postmortem examination did not correlate with the degree of pathological change; and study of the peripheral nervous system favored a primary axonal neuropathy with secondary demyelination.
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PMID:Polyneuropathy and IgM monoclonal gammopathy: studies on the pathogenetic role of anti-myelin-associated glycoprotein antibody. 258 96


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