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1.
Gait Posture ; 108: 35-43, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37980833

RESUMO

BACKGROUND: Promoting an erect posture in standing has been advocated to offer superior protection to the spine when compared to hyperlordotic and swayback postures. RESEARCH QUESTION: Do postural adjustments towards external perturbation differ between erect, hyperlordotic and swayback postures? If so, which posture offers better protection to lumbar spine? METHODS: Forty-four healthy adults received top-down perturbations under unpredictable (without visual-and-auditory input) and predictable (with visual-and-auditory input) conditions in three simulated postures: erect, hyperlordotic, and swayback. Postural adjustments namely the centre of pressure parameters, joint angle onsets, and neuromuscular responses measured by muscle onsets and co-contraction between muscle pairs upon the perturbation were compared using the two-way repeated measures ANOVA. Post-hoc analysis with Bonferroni correction was conducted to identify the between-posture differences for the respective postural adjustment parameters. RESULTS: Path length, ellipse area and average velocity of centre of pressure were significantly greater under unpredictable condition as compared to predictable condition (p < 0.001). Significant between-posture difference was detected in centre of pressure path length (p < 0.035), pelvic tilt onset (p < 0.038) and all muscle co-contraction indexes (p < 0.001). Post-hoc analysis revealed significantly smaller centre of pressure path length in erect posture as compared to hyperlordotic and swayback postures (p < 0.01) under unpredictable conditions. Significantly greater co-contraction indexes of lumbar multifidus and erector spinae, and internal oblique and lumbar multifidus were found in hyperlordotic as compared to erect and swayback postures (p < 0.05). SIGNIFICANCE: Compared to erect posture, adoption of hyperlordotic and swayback postures altered the contributions of the active and passive subsystems of the spine that regulates postural control upon external perturbations. Such differences in neuromuscular control may lessen the capacity of the human spine to withstand loading and shear forces. Prospective studies are required to validate if habitually adopted hyperlordotic and swayback postures contribute to an earlier/ higher prevalence of spinal dysfunctions.


Assuntos
Lordose , Lordose Equina , Adulto , Ovinos , Animais , Humanos , Músculo Esquelético/fisiologia , Postura/fisiologia , Vértebras Lombares , Eletromiografia
3.
Can Vet J ; 46(11): 1017-21, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16363328

RESUMO

Endoparasitism is a problem in Trinidad, as it is in most tropical countries. Parasite infection has been suspected to contribute to the pathogenesis of swayback disease (which is also prevalent in Trinidad), but the mode of action has not been clearly defined, although it has been suggested that parasites interfere with the absorption of copper from the gastrointestinal tract. The objectives of the study were to assess the effect of endoparasitism on blood copper levels and hemoglobin (Hb) concentration in sheep in Trinidad. Copper was administered intramuscularly to parasite infected and noninfected animals. The results showed that parasitism has a depressing effect on blood copper and Hb levels, even when administered parenterally. It is concluded that parasitism can aggravate existing hypocupremia and possibly influence the expression of swayback disease.


Assuntos
Cobre , Hemoglobinas/análise , Infecções por Nematoides/veterinária , Doenças dos Ovinos/sangue , Animais , Cobre/administração & dosagem , Cobre/sangue , Cobre/deficiência , Feminino , Infecções por Nematoides/sangue , Infecções por Nematoides/complicações , Ovinos , Doenças dos Ovinos/etiologia , Lordose Equina/sangue , Lordose Equina/complicações , Trinidad e Tobago/epidemiologia
8.
Mol Chem Neuropathol ; 34(2-3): 233-47, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-10327420

RESUMO

Swayback disease, a neurodegenerative disorder of lambs, and Menkes disease, the human equivalent, are caused by a deficiency of dietary copper. Reports of low enzymic activity suggest that several copper-containing enzymes, including cytochrome-c oxidase (COX), may influence the progress of these diseases. To investigate its role in the development of neurodegenerative disorders, in particular swayback disease, we isolated COX from the brains and livers of swayback-diseased lambs. Comparative sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) combined with densitometric analysis revealed that whereas the structure of COX from the liver of diseased animals was normal, the corresponding brain enzyme was subunits II-, III-, and IV-deficient; the deficiency was 55, 30, and 65% respectively. The activities of liver and brain COX from normal and diseased lambs were compared by polarographic assay at low ionic strength. Whereas the enzyme from normal brains and both forms of the liver enzyme yielded characteristic biphasic Eadie-Hofstee plots, the brain enzyme from diseased animals displayed a single phase with a K(m) of 4.7 +/- 2.4 x 10(-6) M: the K(m) values of COX from the normal brain were 12 +/- 2.5 x 10(-6) and 5.5 +/- 0.5 x 10(-7) M. We conclude that the altered enzyme structure accounts for the uncharacteristic kinetics and low activity we have observed for the isolated brain enzyme. We also conclude that the altered enzyme structure partly accounts for the low oxidase activity and decreased ATP synthesis that has been widely reported for brain tissue from swayback-diseased animals. We postulate that the subunit deficiency probably results from incomplete crosslinking between the subunits and the membrane, and predict that similar structural and kinetic factors may also account for low COX activity in Menkes disease.


Assuntos
Encéfalo/enzimologia , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias/enzimologia , Lordose Equina/enzimologia , Animais , Complexo IV da Cadeia de Transporte de Elétrons/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Humanos , Cinética , Síndrome dos Cabelos Torcidos/enzimologia , Mitocôndrias Hepáticas/enzimologia , Concentração Osmolar , Polarografia , Valores de Referência , Ovinos
9.
J Vet Med Sci ; 58(9): 849-54, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8898282

RESUMO

Thirteen Sika deer (Cervus nippon Temminck) showing ataxia on a stock farm in the north eastern district of China were examined histopathologically. The principal pathological changes were spongy vacuolation and myelin deficiency in the white matter of the spinal cord and brain stem, fibrosis and rupture of the elastic lamina of the spinal arterioles, and mesothelial hyperplasia in the spinal arachnoid. Other findings included defective formation of the elastic laminae of the aorta, and the blood vessels in the kidney and lung, hemosiderosis in the spleen and liver, and lymphocyte depletion in the systemic lymph nodes. Copper concentrations were low in the serum and liver. In the white matter of the spinal cord and brain stem, demyelination appeared to coexist with dysmyelination and secondary myelin breakdown. It was inferred that decreased activity of copper containing enzyme induced various lesions. The possible role of copper deficiency in the pathogenesis of the ataxic conditions is discussed.


Assuntos
Tronco Encefálico/patologia , Cervos , Medula Espinal/patologia , Lordose Equina/patologia , Animais , Aorta/patologia , Arteríolas/patologia , Tronco Encefálico/ultraestrutura , China/epidemiologia , Cobre/análise , Cobre/sangue , Cobre/deficiência , Feminino , Rim/irrigação sanguínea , Fígado/química , Pulmão/irrigação sanguínea , Masculino , Proteínas da Mielina/análise , Proteínas da Mielina/metabolismo , Ovinos , Medula Espinal/ultraestrutura , Lordose Equina/epidemiologia , Lordose Equina/metabolismo
10.
J S Afr Vet Assoc ; 67(2): 93-6, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8765071

RESUMO

Ataxia associated with myelopathy and low liver copper concentrations is described in a blesbok (Damaliscus dorcas phillipsi) and black wildebeest (Connochaetes gnou) from the Karoo Nature Reserve, Graaff-Reinet. This syndrome, which occurs in neonatal and delayed forms, has been described in sheep, goats, pigs and domesticated red deer, but reports in other ungulates, including antelope, are very rare and generally unconfirmed by histopathological examination. The 2 animals examined exhibited a typical pattern of Wallerian degeneration in selected tracts of the spinal cord. Many blesbok in the reserve are markedly pale in colour. Fading of the hair is also associated with copper deficiency in ungulates. High lamb mortality occurs as a result of the ataxia and threatens the survival of the blesbok herd in the reserve. Confirmation of low liver copper concentrations in affected animals offers direction towards the solution of the problem.


Assuntos
Antílopes/metabolismo , Cobre/deficiência , Lordose Equina/etiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ataxia/patologia , Ataxia/veterinária , Encéfalo/metabolismo , Encéfalo/patologia , Proteínas na Dieta/metabolismo , Feminino , Rim/metabolismo , Rim/patologia , Fígado/metabolismo , Fígado/patologia , Masculino , Ovinos , África do Sul , Medula Espinal/metabolismo , Medula Espinal/patologia , Lordose Equina/diagnóstico , Lordose Equina/patologia
11.
Mol Chem Neuropathol ; 28(1-3): 285-93, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8871971

RESUMO

Swayback disease (SD), a fatal neurological disorder affecting lambs and kids, is characterized by abnormal mitochondria and low cytochrome-c oxidase activity. The cytochrome-c oxidase content and activity and the protein composition of mitochondria isolated from the brains of SD lambs were investigated. Difference spectra analysis indicated that the cytochrome-c oxidase content of mitochondria from SD animals was lower than normal, and electrophoresis showed that when compared to mitochondria from normal animals, lipid-depleted mitochondria from SD lambs had a different protein composition, particularly, in the 40-55 kDa region. Polarographic studies, using cytochrome-c as substrate, confirmed low intrinsic activity of cytochrome-c oxidase within the mitochondria of SD lambs. These studies also showed that at low ionic strength, such mitochondria did not yield the expected characteristic biphasic Eadie-Hofstee plots.


Assuntos
Encéfalo/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias/metabolismo , Proteínas/metabolismo , Lordose Equina/metabolismo , Animais , Oxirredução , Polarografia , Proteínas/isolamento & purificação , Valores de Referência , Ovinos
12.
J Comp Pathol ; 114(3): 283-90, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8762586

RESUMO

The livers of 13 Sika deer (Cervus nippon Temminck) aged 4 to 9 years and suffering from copper deficiency (enzootic ataxia) were examined histologically, histochemically and by electron microscopy. In addition, the serum and liver copper concentrations, measured in three animals, were found to be low. Histologically, the hepatocytes exhibited cloudy swelling, and numerous haemosiderin deposits were seen in the hepatocytes and Kupffer cells. Staining with p-dimethyl amino-benzylidene-rhodamine revealed distinctly fewer copper granules than normal. Histochemically, 3,3'-diaminobenzidine-H2O2 staining revealed increased numbers of catalase-positive granules around nuclei. Electron microscopically, "giant" and bizarre-shaped mitochondria, irregular depression of the mitochondrial membrane, and fusion of cristae were noted. Disorders of copper-containing enzymes, including cytochrome oxidase, caeruloplasmin and monoamine oxidase, may have been responsible for the mitochondrial abnormalities.


Assuntos
Cobre/deficiência , Cervos/anatomia & histologia , Fígado/ultraestrutura , Lordose Equina/patologia , Animais , Animais Domésticos , Ceruloplasmina/análise , Cobre/análise , Cobre/sangue , Surtos de Doenças/veterinária , Complexo IV da Cadeia de Transporte de Elétrons/análise , Feminino , Fígado/química , Masculino , Mitocôndrias Hepáticas/ultraestrutura , Monoaminoxidase/análise , Ovinos , Lordose Equina/epidemiologia , Lordose Equina/etiologia
14.
Vet Res Commun ; 18(4): 251-60, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7831754

RESUMO

The clinical signs of camel sway disease in the Hexi Corridor of Gansu province were defined. The contents of eight minerals in soils, in forage and in the blood and hair of bactrian camels from this region were determined. The related blood indices were also measured. The concentration of molybdenum in soils and forage was 4.8 +/- 0.02 and 4.8 +/- 0.25 micrograms/g (dry matter), respectively, the copper to molybdenum ratio in the forage being only 1.3. The concentration of copper in blood and hair from the camels was 0.28 +/- 0.17 micrograms/ml and 3.50 +/- 1.00 micrograms/g, respectively. There was a hypochromic microcytic anaemia and a low level of ceruloplasmin in the blood. It is therefore suggested that sway disease of bactrian camels in this region is caused by secondary copper deficiency, mainly due to the high molybdenum content in soils and forage. The copper deficiency in the camels was aggravated during reproduction. Oral administration of copper sulphate can prevent and cure the disease.


Assuntos
Ração Animal/análise , Camelus , Cobre/análise , Solo/análise , Lordose Equina/etiologia , Animais , Contagem de Células Sanguíneas/veterinária , Camelus/sangue , China , Cobre/deficiência , Cobre/uso terapêutico , Sulfato de Cobre , Ovinos , Lordose Equina/sangue , Lordose Equina/tratamento farmacológico
17.
Vet Rec ; 118(24): 657-60, 1986 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-3526699

RESUMO

Clinical, biochemical and pathological findings led to a diagnosis of swayback in a herd of goats. Trace element values in soil, pasture and supplementary feed were measured, and copper oxide needles administered to the adult goats. This form of treatment had a more limited effect in these goats than is reported in sheep.


Assuntos
Cobre/uso terapêutico , Doenças Desmielinizantes/veterinária , Cabras , Animais , Cobre/sangue , Doenças Desmielinizantes/sangue , Doenças Desmielinizantes/tratamento farmacológico , Doenças Desmielinizantes/patologia , Feminino , Masculino , Ovinos , Lordose Equina/sangue , Lordose Equina/tratamento farmacológico , Lordose Equina/patologia
18.
Vet Q ; 8(1): 45-56, 1986 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3515745

RESUMO

The results of a retrospective study of 23 goat kids with delayed swayback are reported. Principal clinical signs were ataxia, loss of postural control, spasticity of the hindlimbs, and muscular weakness, often progressing to permanent recumbency. Denervation of skeletal muscles was demonstrated by electromyography in 2 kids. Three kids slowly recovered during hospitalisation. Histopathological changes were characterized by degeneration of selected neuronal populations with their processes within the central and the peripheral nervous system. Affected systems included upper motor neuron, vestibular, general proprioceptive, and lower motor neuron pathways, with additional involvement of the cerebellar cortex in some animals. Our findings, including limited ultrastructural observations, support the notion that the neuraxon rather than the myelin sheath is the prime target of disease in delayed swayback. The available copper values of affected kids and their unaffected herd mates were significantly lower than those of random control goats, which provides further support for a role of copper deficiency in the aetiology of this disease in the goat.


Assuntos
Encéfalo/patologia , Cabras , Doenças dos Ovinos/patologia , Medula Espinal/patologia , Lordose Equina/patologia , Animais , Cobre/deficiência , Neurônios Motores/patologia , Músculos/patologia , Estudos Retrospectivos , Ovinos , Nervos Espinhais/patologia , Lordose Equina/etiologia , Fatores de Tempo
20.
J Neurol Neurosurg Psychiatry ; 48(9): 859-65, 1985 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-4045479

RESUMO

Four out of seven research workers into swayback disease, a neurological disease of lambs, developed symptoms and signs of multiple sclerosis, and were reported in 1947. A further worker later joined the group. All of the original seven have died and two at necropsy had multiple areas of demyelination in the brain and spinal cord. The chance of four or more out of a random group of eight men developing multiple sclerosis is about one in a thousand million. Multiple sclerosis has not occurred in other workers on swayback disease elsewhere.


Assuntos
Esclerose Múltipla/epidemiologia , Doenças Profissionais/epidemiologia , Pesquisadores , Doenças dos Ovinos , Lordose Equina , Medicina Veterinária , Adulto , Animais , Sistema Nervoso Central/patologia , Inglaterra , Seguimentos , Humanos , Masculino , Esclerose Múltipla/patologia , Ovinos , Conglomerados Espaço-Temporais
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