scholarly journals Ultrastructural Lesions of Pyridoxine Toxicity in Beagle Dogs

1981 ◽  
Vol 18 (6) ◽  
pp. 769-777 ◽  
Author(s):  
D. M. Hoover ◽  
W. W. Carlton ◽  
C. K. Henrikson

Three adult Beagle dogs given pyridoxine hydrochloride orally at a dose of 150 mg/kg body weight/day for about 100 days developed ataxia and had spastic, dysmetric leg movements. Ultrastructural alterations in the dorsal funiculus of the spinal cord were degeneration and loss of axons and myelin, and secondary changes of the myelin sheaths. Possible pathogenic mechanisms of pyridoxine neurotoxicity are discussed.

1981 ◽  
Vol 18 (6) ◽  
pp. 757-768 ◽  
Author(s):  
D. M. Hoover ◽  
W. W. Carlton

The lesions caused by excess oral pyridoxine hydrochloride (150 mg/kg body weight/day) and clioquinol (200 mg/kg body weight/day), given individually and in combination to adult Beagle dogs, were evaluated. The experimental period was 100 to 112 days, except that four dogs in each of the clioquinol and combined-treatment groups were killed early because of severe debilitation or neurologic disease, and one dog given both compounds died on the third day of compound administration. Degenerative neurologic lesions had distribution specific for the compound given. Pyridoxine-treated dogs had lesions limited to tracts and nerves with neuronal bodies of their nerve fibers in the spinal and trigeminal ganglia. Clioquinol-treated dogs had neurologic lesions limited to the central nervous system. The most severe lesions were in the rostral dorsal funiculus and distal aspects of the optic nerve fibers, but minimal to mild degenerative changes also occurred in distal aspects of the corticospinal and spinocerebellar tracts. Dogs given both pyridoxine hydrochloride and clioquinol had a combination of the lesions in dogs given pyridoxine or clioquinol individually. Several dogs given clioquinol or pyridoxine plus clioquinol had extraneural lesions, including myocardial degeneration and thyroidal alterations.


1981 ◽  
Vol 18 (6) ◽  
pp. 745-756 ◽  
Author(s):  
D. M. Hoover ◽  
W. W. Carlton

The clinical and clinicopathologic effects of excess oral pyridoxine hydrochloride (150 mg/kg body weight/day) and clioquinol (200 mg/kg body weight/day) alone and in combination were evaluated in adult Beagle dogs over an experimental period of approximately 100 days. Anorexia and loss of body weight occurred in the first weeks of the trial period in each treatment group, but was most severe in dogs given both compounds. Dogs in each treatment group (10 of 10 pyridoxine-treated dogs, 6 of 13 clioquinol-treated dogs and 12 of 13 pyridoxine plus clioquinol-treated dogs) developed neurologic disease, manifested principally by ataxia. Pyridoxine-treated dogs had proprioceptive loss involving both fore- and hindquarters, characterized by stiff, spastic, dysmetric leg movements. In clioquinol-treated dogs, dysmetric leg movements were accompanied by failure to support body weight in the hindquarters, but similar forelimb involvement occurred in severely affected dogs. The neurologic disease in dogs given both compounds varied; signs in some dogs resembled those of affected dogs of the pyridoxine-treated group, and in others, those in the clioquinol-treated group. Erythrocyte counts, hemoglobin concentrations and packed cell volumes were reduced in dogs in each treatment group and were lowest in dogs given both compounds. Plasma protein was mildly reduced in dogs given pyridoxine or pyridoxine plus clioquinol. Few or no differences were present in the leukocyte counts, blood urea nitrogen concentrations, in activities of serum alanine aminotransferase and aspartate aminotransferase, and in concentrations of sodium, chloride or potassium in treated dogs as compared to control dogs.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samira Ahmadvand Koohsari ◽  
Abdorrahim Absalan ◽  
Davood Azadi

AbstractThe therapeutic effects of mesenchymal stem cells-extracellular vesicles have been proved in many inflammatory animal models. In the current study, we aimed to investigate the effect of extracellular vesicles (EVs) derived from human umbilical cord-MSC (hUCSC-EV) on the clinical score and inflammatory/anti-inflammatory cytokines on the EAE mouse model. After induction of EAE in C57Bl/6 mice, they were treated intravenously with hUCSC-EV or vehicle. The clinical score and body weight of all mice was registered every day. On day 30, mice were sacrificed and splenocytes were isolated for cytokine assay by ELISA. Cytokine expression of pro-/anti-inflammatory cytokine by real-time PCR, leukocyte infiltration by hematoxylin and eosin (H&E) staining, and the percent of glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) positive cells by immunohistochemistry were assessed in the spinal cord. Our results showed that hUCSC-EV-treated mice have lower maximum mean clinical score (MMCS), pro-inflammatory cytokines, and inflammatory score in comparison to the control mice. We also showed that hUCSC-EV administration significantly improved body weight and increased the anti-inflammatory cytokines and the frequency of Treg cells in the spleen. There was no significant difference in the percent of GFAP and MBP positive cells in the spinal cord of experimental groups. Finally, we suggest that intravenous administration of hUCSC-EV alleviate induce-EAE by reducing the pro-inflammatory cytokines, such as IL-17a, TNF-α, and IFN-γ, and increasing the anti-inflammatory cytokines, IL-4 and IL-10, and also decrease the leukocyte infiltration in a model of MS. It seems that EVs from hUC-MSCs have the same therapeutic effects similar to EVs from other sources of MSCs, such as adipose or bone marrow MSCs.


1992 ◽  
Vol 29 (3) ◽  
pp. 230-238 ◽  
Author(s):  
J. E. Burkhardt ◽  
M. A. Hill ◽  
J. J. Turek ◽  
W. W. Carlton

The ultrastructural features of quinolone-induced arthropathy were studied in' the humeral and femoral heads of nine skeletally immature Beagle dogs (3 months old) that were dosed orally with difloxacin at 300 mg/kg body weight and euthanatized 24, 36, or 48 hours later in groups of three. Three age-matched dogs were given a placebo and euthanatized after 48 hours. Mitochondria in chondrocytes had significantly greater cross-sectional areas ( P < 0.05) in electron micrographs from dogs euthanatized after 48 hours of treatment than did those in other groups. There was also a significantly greater percentage of chondrocytes with swollen mitochondria in treated dogs than in the controls ( P < 0.05). These changes preceded the necrosis observed in some chondrocytes in the dogs of the 48-hour group. Disruption of extracellular matrix was first observed in the pericellular matrix of necrotic chondrocytes, indicating that this change was secondary to the changes in chondrocytes. Fissures within cartilages apparently resulted from the loss of the normal association of proteoglycans with collagen fibrils.


2021 ◽  
Vol 6 (4) ◽  
pp. 191-197
Author(s):  
Kanika Singhal ◽  
Chitra Kataria

Background: Rhythmic auditory stimulation and body weight supported treadmill training both are standardized gait rehabilitation techniques. However there is limited literature evaluating the effect of rhythmic auditory stimulation and its combination with gait training in spinal cord injury. Aim of this study is to determine the short term effectiveness of rhythmic auditory stimulation with body weight supported treadmill training on gait and balance in individuals with incomplete Spinal Cord Injury. Method: A randomized control study design. 8 subjects with incomplete spinal cord injury who met the inclusion criteria were randomly allocated into two groups: Experimental and Control. Subjects in experimental group were given body weight supported treadmill training with rhythmic auditory stimulation. Subjects in Control Group were given Body weight supported treadmill training alone. Both the groups received conventional rehabilitation as well. Both groups received training for 30 minutes, five times a week for two weeks (10 sessions). Outcome Measures: Gait parameters i.e. cadence, velocity, step length were measured using the Biodex Gait Trainer 2TM, level of walking performance measured using Walking Index for Spinal Cord Injury II, and balance was evaluated using Prokin 252NTM , Berg Balance Scale, and Activity specific Balance Confidence scale. Results: No significant improvement was found on gait parameters i.e. cadence, velocity, step length which were measured using the Gait Trainer, level of walking performance measured using WISCI II, and balance which was evaluated using Prokin 252NTM , Berg Balance Scale, and Activity specific Balance Confidence scale. Conclusion: Rhythmic auditory stimulation didn’t have any positive effect on gait training in incomplete spinal cord injured patients. Further studies are warranted to explore the entrainment effects of rhythmic auditory stimulation in spinal cord injured individuals on gait rehabilitation. Keywords: Rhythmic Auditory Stimulation (RAS), Body Weight Supported Treadmill Training (BWSTT), Metronome, Incomplete spinal cord injury, Biodex Gait Trainer 2.0, Prokin 252N


2001 ◽  
Vol 19 (4) ◽  
pp. 702-710
Author(s):  
Renata Teles Vieira ◽  
Rafaela Machado de Gusmão Oliveira ◽  
Camila Alves Nogueira Barros ◽  
Leonardo Caixeta

Objetivo. O objetivo deste trabalho foi realizar uma revisão de literatura sobre o uso do treino locomotor em pacientes portadores de lesão medular incompleta, a fim de verificar os seus efeitos para a marcha destes pacientes. Método. Foi realizada uma busca utilizando os bancos de dados medline, scielo e bvs a partir dos descritores: body weight-support treadmill training (suporte parcial de peso com treinamento em esteira), locomotor training (treino locomotor), spinal cord injury (lesão medular), gait (marcha). Todos os artigos coletados nos últimos 18 anos foram analisados. Discussão. A lesão medular é uma grave síndrome neurológica que causa diversos comprometimentos, inclusive da marcha. Para aperfeiçoar este processo, deu-se início à prática de reabilitação na esteira com suporte de peso corporal. A ampla utilização desta técnica de reabilitação deve-se a maior facilidade para o treino da marcha, a satisfação dos pacientes durante o tratamento e, principalmente, aos bons resultados gerados. Conclusão. Um número significante de estudos mostrou que o treino de marcha com suporte de peso corporal é um meio seguro e confiável, e que surgiu para inovar a reabilitação funcional da marcha. Não há evidência científica para afirmar que o treino locomotor com suporte de peso seja um método superior a outras terapias.


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