Cyclosporin safety in a simplified rat brain tumor implantation model.

Brain cancer is the second neurological cause of death. A simplified animal brain tumor model using W256 (carcinoma 256, Walker) cell line was developed to permit the testing of novel treatment modalities. Wistar rats had a cell tumor solution inoculated stereotactically in the basal ganglia (right subfrontal caudate). This model yielded tumor growth in 95% of the animals, and showed absence of extracranial metastasis and systemic infection. Survival median was 10 days. Estimated tumor volume was 17.08 ± 6.7 mm(3) on the 7(th) day and 67.25 ± 19.8 mm(3) on 9(th) day post-inoculation. Doubling time was 24.25 h. Tumor growth induced cachexia, but no hematological or biochemical alterations. This model behaved as an undifferentiated tumor and can be promising for studying tumor cell migration in the central nervous system. Dexamethasone 3.0 mg/kg/day diminished significantly survival in this model. Cyclosporine 10 mg/kg/day administration was safely tolerated.

Cyclosporin safety in a simplified rat brain tumor implantation model / Segurança do tratamento com ciclosporina em um modelo pré-clínico de tumor cerebral experimental em ratos

Brain cancer is the second neurological cause of death. A simplified animal brain tumor model using W256 (carcinoma 256, Walker) cell line was developed to permit the testing of novel treatment modalities. Wistar rats had a cell tumor solution inoculated stereotactically in the basal ganglia (right subfrontal caudate). This model yielded tumor growth in 95 percent of the animals, and showed absence of extracranial metastasis and systemic infection. Survival median was 10 days. Estimated tumor volume was 17.08±6.7 mm³ on the 7th day and 67.25±19.8 mm³ on 9th day post-inoculation. Doubling time was 24.25 h. Tumor growth induced cachexia, but no hematological or biochemical alterations. This model behaved as an undifferentiated tumor and can be promising for studying tumor cell migration in the central nervous system. Dexamethasone 3.0 mg/kg/day diminished significantly survival in this model. Cyclosporine 10 mg/kg/day administration was safely tolerated.

Neoplasias encefálicas constituem a segunda causa neurológica de morte. Foi desenvolvido um modelo animal simplificado de tumor cerebral em ratos utilizando a linhagem celular W256 (carcinoma 256 de Walker) para permitir teste de novos tratamentos. Ratos Wistar foram inoculados nos gânglios da base (caudato subfrontal direito) com uma solução celular tumoral, por via estereotáxica. Este modelo demonstrou crescimento tumoral em 95 por cento dos animais inoculados com sucesso, além de mostrar ausência de metástases extracranianas e infecção sistêmica. A mediana de sobrevida dos animais foi de 10 dias. O volume tumoral estimado foi de 17,08±6,7 mm³ no sétimo dia e de 67,25±19,8 mm³ no nono dia após a inoculação. O tempo de duplicação foi estimado em 24,25 h. O crescimento tumoral induziu a caquexia, mas não houve alterações bioquímicas ou hematológicas. Esse modelo permite fácil reprodução e comporta-se como um tumor indiferenciado, mostrando potencial para estudar migração celular tumoral no sistema nervoso central. Dexametasona 3,0 mg/kg/dia reduziu significantemente a sobrevida dos animais inoculados com tumor nesse modelo. Ciclosporina 10 mg/kg/dia não teve efeito na sobrevida, sendo sua administração bem tolerada.

Analysis of survival and prognostic factors of pediatric patients with brain tumor.

OBJECTIVES: To estimate survival and evaluate prognostic factors of pediatric patients with central nervous system (CNS) tumors treated in a single center. METHODS: Retrospective analysis of survival of 103 children with primary brain tumors diagnosed consecutively from January 2000 to December 2006. Cox regression was used for multivariate analysis of factors that affect overall survival to define possible prognostic factors. RESULTS: Median and mean ages were 7.2 and 7.6 years. There was a male predominance (1.22:1). Most patients had medulloblastomas or primitive neuroectodermal tumors (PNET, 38%), or low-grade astrocytomas (18%). The anatomic site of most tumors was the cerebellum (49%) and the brain stem (21%). Five-year survival after diagnosis was 84% for low-grade astrocytomas and 51% for medulloblastomas and PNET. Prognostic factors for overall survival were histopathological type (high-grade astrocytomas and ependymomas; hazard ratio = 3.7 to 3.9), surgery (hazard ratio of 0.5 for completely resected tumors) and radiotherapy (hazard ratio of 0.5 for patients who underwent radiotherapy). CONCLUSIONS: Overall survival of pediatric patients with brain tumors in this study was similar to that found in populations of the United States and Europe. The prognostic factors defined for overall survival are also similar to those published in previous studies.

Análise de sobrevida e fatores prognósticos de pacientes pediátricos com tumores cerebrais / Analysis of survival and prognostic factors of pediatric patients with brain tumor

OBJETIVOS: Realizar análise de sobrevida e avaliar, através de análise multivariada, a influência de diversas variáveis na sobrevida, definindo fatores prognósticos de pacientes pediátricos com tumores do sistema nervoso central (SNC) tratados em um único centro. MÉTODOS: Analisamos, retrospectivamente, a sobrevida de 103 crianças portadoras de tumores cerebrais primários, diagnosticadas consecutivamente no período entre janeiro de 2000 e dezembro de 2006. Análise multivariada de fatores influenciando a sobrevida global por regressão de Cox foi usada para definir possíveis fatores prognósticos. RESULTADOS: A mediana e a média de idade foram de 7,2 e 7,6 anos. Houve predominância do sexo masculino (relação 1,22:1). A maioria dos pacientes tinha meduloblastoma ou tumores neuroectodérmicos primitivos (PNET, 38 por cento) ou astrocitomas de baixo grau (18 por cento). As topografias mais comuns foram cerebelar (49 por cento) e tronco cerebral (21 por cento). A sobrevida, 5 anos após o diagnóstico, foi de 84 por cento para astrocitomas de baixo grau e 51 por cento para meduloblastomas e PNET. Fatores prognósticos para a sobrevida global foram histopatológico (astrocitomas de alto grau e ependimomas, razão de risco entre 3,7 e 3,9), cirurgia (razão de risco 0,5 para tumores completamente ressecados) e radioterapia (razão de risco 0,5 para pacientes que receberam radioterapia). CONCLUSÕES: A sobrevida global de pacientes pediátricos com tumores cerebrais neste estudo é comparável àquela dos registros populacionais dos Estados Unidos e Europa. Os fatores de prognóstico definidos para sobrevida global também se assemelham àqueles previamente publicados.

OBJECTIVES: To estimate survival and evaluate prognostic factors of pediatric patients with central nervous system (CNS) tumors treated in a single center. METHODS: Retrospective analysis of survival of 103 children with primary brain tumors diagnosed consecutively from January 2000 to December 2006. Cox regression was used for multivariate analysis of factors that affect overall survival to define possible prognostic factors. RESULTS: Median and mean ages were 7.2 and 7.6 years. There was a male predominance (1.22:1). Most patients had medulloblastomas or primitive neuroectodermal tumors (PNET, 38 percent), or low-grade astrocytomas (18 percent). The anatomic site of most tumors was the cerebellum (49 percent) and the brain stem (21 percent). Five-year survival after diagnosis was 84 percent for low-grade astrocytomas and 51 percent for medulloblastomas and PNET. Prognostic factors for overall survival were histopathological type (high-grade astrocytomas and ependymomas; hazard ratio = 3.7 to 3.9), surgery (hazard ratio of 0.5 for completely resected tumors) and radiotherapy (hazard ratio of 0.5 for patients who underwent radiotherapy). CONCLUSIONS: Overall survival of pediatric patients with brain tumors in this study was similar to that found in populations of the United States and Europe. The prognostic factors defined for overall survival are also similar to those published in previous studies.

Antiplatelet effects of piplartine, an alkamide isolated from Piper tuberculatum: possible involvement of cyclooxygenase blockade and antioxidant activity.

OBJECTIVES: Piplartine (piperlongumine; 5,6-dihydro-1-[1-oxo-3-(3,4,5-trimethoxyphenyl]-2(1H) pyridinone) is an alkaloid amide isolated from Piper species (Piperaceae). It has been reported to show multiple pharmacological activities in vitro and in vivo. METHODS: We evaluated the in-vitro antiplatelet effect of piplartine isolated from the roots of P. tuberculatum, on human platelet aggregation induced in platelet-rich plasma by the agonists collagen, adenosine 5'-diphosphate (ADP), arachidonic acid (AA) and thrombin. KEY FINDINGS: Piplartine (100 mug/ml) caused a 30% inhibition in platelet aggregation when collagen was the agonist. At 200 mug/ml, piplartine significantly inhibited the aggregation induced by arachidonic acid (100%), collagen (59%) or ADP (52%) but not that induced by thrombin. The highest concentration of piplartine (300 mug/ml) inhibited thrombin- (37%), ADP- (71%) and collagen- (98%) induced aggregation. The inhibitory effect of piplartine on ADP-induced platelet aggregation was not modified by pretreatment with pentoxifylline (a phosphodiesterase inhibitor), L-arginine (a substrate for nitric oxide synthase) or ticlopidine (a P2Y(12) purinoceptor antagonist). However, aspirin, a well-known inhibitor of cyclooxygenase, greatly increased the inhibitory effect of piplartine on arachidonic-acid-induced platelet aggregation. CONCLUSIONS: The mechanism underlying the piplartine antiplatelet action is not totally clarified. It could be related to the inhibition of cyclooxgenase activity and a decrease in thromboxane A(2) formation, similar to that occurring with aspirin. This and other possible mechanisms require further study.

Analgesic and anti-inflammatory activities of a fraction rich in oncocalyxone A isolated from Auxemma oncocalyx.

In the present work we studied the antinociceptive and antiedematogenic effects of a quinone fraction (QF) isolated from the heartwood of Auxemma oncocalyx Taub. The major constituent of QF, which represented around 80% of this fraction, was a terpenoid quinone named oncocalyxone A (1). Results show that QF (10 and 30 mg/kg body wt., i.p.) significantly inhibited paw edema induced by carrageenan at the second, third, and fourth hours. The effect was dose-dependent and long lasting, and QF was less effective orally. An antiedematogenic effect was also demonstrated in the dextran-induced paw edema. In this model, however, QF was somewhat less potent. QF (1 and 5 mg/kg body wt., i.p.) inhibited acetic acid-induced abdominal contractions in mice in a dose-dependent manner. In addition, QF (5 and 10 mg/kg body wt., i.p.) inhibited only the second phase (inflammatory) in the formalin test, and showed no effect in the hot-plate test in mice. The antinociceptive activity of QF was predominantly peripheral and independent of the opioid system. The observed effects of QF are, at least in part, probably due to the presence of oncocalyxone A (1).