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1.
Trans R Soc Trop Med Hyg ; 101(2): 104-12, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16860356

RESUMO

A recent therapeutic index study in rats demonstrated that i.v. artesunate (AS) is safer than artelinate (AL). The present study of acute toxicity illustrated an LD(50) of 177 mg/kg and 488 mg/kg for AL and AS, respectively, following daily i.v. injection for 3 days in Plasmodium berghei-infected rats. In uninfected rats, the LD(50) values were 116 mg/kg and 351 mg/kg after a single dose of AL and AS, respectively. This study showed vascular necrosis in 50% of the animals at 13.5 mg/kg AL and at 42.8 mg/kg AS. Animals also showed moderate signs of renal failure at 40 mg/kg AL and 240 mg/kg AS (100 times higher than the therapeutic dose). Histopathological evaluation demonstrated mild to moderate tubular necrosis in uninfected rats treated with 40 mg/kg AL and 240 mg/kg AS; interestingly, fewer pathological lesions were observed in malaria-infected rats. Renal injury was reversible in all cases by Day 8 after cessation of dosing. No neurotoxicity was seen in any case with all i.v. regimens. In conclusion, AL and AS exhibit less toxic effects in P. berghei-infected rats than in uninfected rats. Both agents caused irreversible vascular irritation, reversible nephrotoxicity and no neurotoxicity at high doses. The data indicate that AS is three times safer than AL in rats.


Assuntos
Injúria Renal Aguda/induzido quimicamente , Antimaláricos/toxicidade , Artemisininas/toxicidade , Encefalopatias/induzido quimicamente , Malária/tratamento farmacológico , Sesquiterpenos/toxicidade , Doenças Vasculares/induzido quimicamente , Injúria Renal Aguda/patologia , Animais , Artesunato , Encefalopatias/patologia , Relação Dose-Resposta a Droga , Dose Letal Mediana , Masculino , Necrose/induzido quimicamente , Necrose/patologia , Plasmodium berghei , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Cauda/irrigação sanguínea , Cauda/patologia , Doenças Vasculares/patologia
2.
Comp Med ; 55(2): 162-8, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15884779

RESUMO

Dilated cardiomyopathy (DCM) was identified histopathologically in a colony of owl monkeys (Aotus nancymae) over a 15-year period. We characterized the incidence of cardiac disease echocardiographically in the colony over a 14-month period. Of 77 monkeys, 21 had systolic myocardial failure, and postmortem examination confirmed the antemortem diagnosis of DCM in eight animals. Monkeys with a questionable diagnosis at the first examination demonstrated progression of disease with time. Left ventricular end-systolic cross-sectional area and left ventricular fractional area change were the indices that most reliably discriminated between normal and diseased animals. Serum cardiac troponin I concentrations were below detectable limits in normal and diseased monkeys. The apparent high prevalence of disease in this colony precluded establishment of reference intervals for Aotus nancymae. Our study provides the first comprehensive echocardiographic evaluation of owl monkeys with cardiomyopathy.


Assuntos
Aotidae , Cardiomiopatia Dilatada/veterinária , Doenças dos Macacos/patologia , Animais , Cardiomiopatia Dilatada/epidemiologia , Cardiomiopatia Dilatada/patologia , District of Columbia/epidemiologia , Ecocardiografia/veterinária , Feminino , Ventrículos do Coração/diagnóstico por imagem , Incidência , Masculino , Doenças dos Macacos/epidemiologia , Radiografia , Sístole , Troponina I/sangue
3.
J Am Vet Med Assoc ; 222(3): 340-2, 316, 2003 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-12564597

RESUMO

A 13-year-old spayed female domestic shorthair cat with an abdominal mass was evaluated; radiography revealed a radiopaque mass in the cranioventral region of the abdomen. A celiotomy was performed, and the mass was identified histologically as a hepatic osteosarcoma. Complete remission of the tumor was accomplished after partial hepatectomy and adjuvant treatment with carboplatin.


Assuntos
Doenças do Gato/diagnóstico , Neoplasias Hepáticas/veterinária , Osteossarcoma/veterinária , Animais , Antineoplásicos/uso terapêutico , Carboplatina/uso terapêutico , Doenças do Gato/patologia , Doenças do Gato/cirurgia , Gatos , Quimioterapia Adjuvante , Feminino , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Recidiva Local de Neoplasia/prevenção & controle , Recidiva Local de Neoplasia/veterinária , Osteossarcoma/diagnóstico , Osteossarcoma/patologia , Osteossarcoma/cirurgia , Prognóstico
4.
J Wildl Dis ; 48(2): 483-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22493127

RESUMO

Three sarcomas were diagnosed in wild northern sea otters (Enhydra lutris kenyoni) during the mid- to late 1990s. Histologically, the tumors were a chondrosarcoma and two low-grade fibrosarcomas with myofibroblastic cell differentiation. The three sea otters were surviving in the wild and were killed by hunters.


Assuntos
Neoplasias Ósseas/veterinária , Condrossarcoma/veterinária , Fibrossarcoma/veterinária , Lontras , Alaska/epidemiologia , Animais , Animais Selvagens , Neoplasias Ósseas/epidemiologia , Neoplasias Ósseas/patologia , Condrossarcoma/epidemiologia , Condrossarcoma/patologia , Feminino , Fibrossarcoma/epidemiologia , Fibrossarcoma/patologia , Masculino
5.
J Vet Cardiol ; 13(1): 71-7, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21303738

RESUMO

A 1 year old intact female Labrador retriever dog presented for evaluation of syncope caused by severe bradycardia. Advanced atrioventricular block was diagnosed. A mass infiltrating the interventricular septum and the tricuspid annulus was identified with echocardiography. Histopathological evaluation of the mass was consistent with cardiac leiomyoma, and immunohistochemical staining for smooth muscle actin confirmed the diagnosis. To the authors' knowledge, this is the first report of cardiac leiomyoma in the canine species.


Assuntos
Bloqueio Atrioventricular/veterinária , Doenças do Cão/etiologia , Neoplasias Cardíacas/veterinária , Leiomioma/veterinária , Animais , Bloqueio Atrioventricular/etiologia , Bloqueio Atrioventricular/patologia , Doenças do Cão/patologia , Cães , Feminino , Neoplasias Cardíacas/complicações , Neoplasias Cardíacas/patologia , Leiomioma/complicações , Leiomioma/patologia
6.
Int J Toxicol ; 26(5): 401-10, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17963127

RESUMO

Neurotoxicity secondary to oil-soluble artemisinins has been reported in various animal species. The onset of neurotoxicity and toxicokinetics of oral artelinic acid (AL), a water-soluble artemisinin, were investigated. After dose range study, rats were dosed at either 160 mg/kg daily for 9 consecutive days or at 288 mg/kg once every other day for five doses, so that the total dose (1440 mg/kg) and duration (9 days) were identical. Neuronal damage of varying severity was identified beginning as early as 1 day after completing dosing and continued for up to 10 days post dosing. Neuronal injury was most severe 7 days after the last treatment in each of the two dosing regimens. The rats dosed with 160 mg/kg of AL daily showed moderate neurotoxicity and lost 22% of their body weight during treatment. Compared with the first dose, the toxicokinetic profile of this regimen changed significantly, with the elimination half-life increasing 3.82-fold and the volume of distribution increasing 5.23-fold on the last day of dosing. In the animals treated with AL at 288 mg/kg every other day for 5 doses, minimal neuronal degeneration (severity score 1.17) was identified and the body weight was only 8% loss. Furthermore, there were no obvious differences in the pharmacokinetic parameters between first and last dosing days with this regimen. Additionally, a progressively drug retention in stomach and drug accretion in blood were only found in rats treated with 160 mg/kg daily for 9 days. These results imply that delayed gastric emptying resulted in AL accumulation in blood and prolonged a neurotoxic exposure time (186 h) in 160 mg/kg rats when compared to that (75 h) in 288 mg/kg animals. Therefore, the drug exposure time is a key factor in the neurotoxicity induced by AL.


Assuntos
Artemisininas/farmacocinética , Artemisininas/toxicidade , Síndromes Neurotóxicas/etiologia , Sesquiterpenos/farmacocinética , Sesquiterpenos/toxicidade , Administração Oral , Animais , Antimaláricos/administração & dosagem , Antimaláricos/farmacocinética , Antimaláricos/toxicidade , Área Sob a Curva , Artemisininas/química , Artemisininas/metabolismo , Disponibilidade Biológica , Tronco Encefálico/efeitos dos fármacos , Tronco Encefálico/patologia , Relação Dose-Resposta a Droga , Esvaziamento Gástrico/efeitos dos fármacos , Meia-Vida , Masculino , Estrutura Molecular , Necrose , Neurônios/efeitos dos fármacos , Neurônios/patologia , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/patologia , Ratos , Ratos Sprague-Dawley , Sesquiterpenos/química , Sesquiterpenos/metabolismo , Fatores de Tempo , Distribuição Tecidual , Redução de Peso/efeitos dos fármacos
7.
Int J Toxicol ; 24(4): 251-64, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16126619

RESUMO

Artesunate (AS) is being developed as a potential agent for the treatment of severe and complicated malaria. A risk assessment of the therapeutic index and related hematological changes of AS and artelinate (AL) following daily intravenous injection for 3 days was conducted in Plasmodium berghei-infected and uninfected rats. The minimum doses of AS and AL for parasitemia suppression were 2.3 and 2.5 mg/kg, respectively, and the suppressive doses for half parasitemia (SD50) were 7.4 and 8.6 mg/kg, respectively. The maximum tolerated dose (MTD) for AS was 240 mg/kg with a therapeutic index of 32.6. The MTD for AL was 80 mg/kg with a therapeutic index of 9.3. Hematological changes were studied on days 1 and 8 after the final dosing. In both AS- and AL-treated rats, dose-dependent and rapidly reversible hematological changes (significant reductions in RBC, HCT, Hb, and reticulocyte levels) were seen in the peripheral blood. Bone marrow evaluation revealed a statistically significant reduction in the myeloid/erythroid ratio only at the highest dose of AS (240 mg/kg), albeit still within the normal ratio range (1.0-1.5:1.0). Looking at the respective therapeutic indices the authors have concluded that AS is much safer than AL. Both drugs induced hematological changes in rats that parallel the dose-dependent, reversible anemia and reticulocytopenia previously reported in animals and humans. However, no significant bone marrow depression was seen for either agent.


Assuntos
Antimaláricos/toxicidade , Artemisininas/toxicidade , Malária/tratamento farmacológico , Plasmodium berghei , Sesquiterpenos/toxicidade , Anemia/induzido quimicamente , Animais , Antimaláricos/administração & dosagem , Artemisininas/administração & dosagem , Artemisininas/farmacocinética , Artesunato , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Contagem de Eritrócitos , Feminino , Hematócrito , Malária/sangue , Malária/parasitologia , Masculino , Dose Máxima Tolerável , Parasitemia/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Contagem de Reticulócitos , Medição de Risco , Sesquiterpenos/administração & dosagem , Sesquiterpenos/farmacocinética , Fatores Sexuais , Equivalência Terapêutica , Fatores de Tempo
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