RESUMEN
Previous studies indicated that Taiwan betel quid is a promoter rather than an initiator during the carcinogenesis of hamster buccal pouch carcinoma. The maximum promoting activity can be demonstrated 24 weeks after betel quid implantation, following an initial application of 0.5% DMBA (7,12-dimethyl benzanthracene) three times per week for 4 weeks. In the present study, components of Taiwan betel quid and its additives (dry betel nut fibre, piper betel, slaked lime, cold aqueous extract, and hot aqueous extract) were applied respectively or in various combinations to investigate their promoting activity. One hundred and thirty Syrian hamsters were divided into 13 groups based on different combinations of the betel quid ingredients applied. The incidence of tumours in the hamster buccal pouch was significantly higher in groups exposed to dry betel nut fibre (P < 0.01) and cold aqueous extract (P < 0.05). The results indicate that betel nut fibre and cold aqueous extract are the major components of betel quid that may promote carcinogenesis in the hamster buccal pouch.
Asunto(s)
Areca , Transformación Celular Neoplásica , Neoplasias de la Boca/etiología , Plantas Medicinales , 9,10-Dimetil-1,2-benzantraceno , Animales , Mejilla , Cocarcinogénesis , Cricetinae , Masculino , Mesocricetus , Extractos Vegetales/toxicidadRESUMEN
Sixty squamous cell carcinomas of tongue and buccal mucosa were examined for expression of p53 protein by using an immunohistochemical technique improved by an antigen retrieval method. Twenty-seven (45%) tumors demonstrated strongly positive staining. Thirteen of p53-positive tumors (48%) also exhibited overexpression of p53 in immediately adjoining hyperplastic or pre-malignant epithelium. All 22 metastatic lymph nodes and 18 local recurrent lesions (except two) had an identical p53 immunophenotype to their corresponding primary sites. Mitotic indices were significantly higher in p53-positive tumors (P < 0.01); however, no association of PCNA scores with p53 expression was found (P > 0.1). There was no correlation between p53 overexpression and tumor grade, size and staging, vascular invasion, lymph node metastasis, and early local recurrence. Overexpression of p53 was found to be relatively higher, although not statistically significant, in nonsmokers than in heavy smokers (66.7% vs. 42.9%), and in nonbetel-quid chewers than in heavy chewers (62.5% vs. 34.2%). These data are consistent with the hypothesis that inactivation of p53 protein may occur in the early phases of oral tumorigenesis. It may not be a useful prognostic marker but could possibly be used for risk assessment and surveillance of local recurrence.
Asunto(s)
Carcinoma de Células Escamosas/patología , Regulación Neoplásica de la Expresión Génica , Mucosa Bucal/patología , Neoplasias de la Boca/patología , Neoplasias de la Lengua/patología , Proteína p53 Supresora de Tumor/genética , Adulto , Anciano , Anciano de 80 o más Años , Areca , Carcinoma de Células Escamosas/genética , Epitelio/patología , Femenino , Humanos , Hiperplasia , Inmunohistoquímica , Metástasis Linfática/genética , Metástasis Linfática/patología , Masculino , Persona de Mediana Edad , Índice Mitótico , Neoplasias de la Boca/genética , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Plantas Medicinales , Lesiones Precancerosas/genética , Lesiones Precancerosas/patología , Antígeno Nuclear de Célula en Proliferación/análisis , Fumar/genética , Taiwán , Neoplasias de la Lengua/genéticaRESUMEN
The effects of interleukin-1 receptor antagonist (IL-Ira) on both local cerebral blood flow and neuronal damage of the hypothalamus, corpus striatum, cortex or thalamus were assessed in rats with heat stroke. Heat stroke was induced by exposing the urethane-anesthetized rats to a high ambient temperature (42 degrees C). Damage to the hypothalamus, corpus striatum, cortex or thalamus was scored on a scale of zero to three modified from the grading system of Pulsinelli and colleagues in which: 0 = normal, 1 = few neurons damaged, 2 = many neurons damaged, and 3 = all neurons damaged. During the onset of heat stroke, as compared to those of normothermia controls, the heat stroke rats displayed a higher value of colonic temperature or neuronal damage score, as well as a lower value of local cerebral blood flow or mean arterial blood pressure. In addition, compared to those of normothermic, control rats, the heat stroke rats had increased interleukin-1 and tumor necroting factor production in the diencephalon, brain stem and cortex. The heat stroke-induced neuronal damage and diminished local cerebral blood flow in different brain structures, as well as the systemic hypotension, were attenuated in animals pretreated with IL-1ra (200 micrograms/kg, iv) 30 min before the onset of heat stroke. The results indicate that IL-1ra attenuates the heat stroke-induced cerebral neuronal damage by reducing cerebral ischemia in rats.