Typing class I HLA-A gene using a nested PCR-RFLP procedure

In order to detect several new HLA-A class I alleles that have been described since 1998, the original PCR-RFLP method developed to identify the 78 alleles recognized at that time at high resolution level was adapted by us for low and medium resolution levels using a nested PCR-RFLP approach. The results obtained from blood samples of 23 subjects using both the PCR-RFLP method and a commercial kit (MicroSSP1A®, One Lambda Inc.) showed an agreement higher than 95 percent. The PCR-RFLP adapted method was effective in low and medium resolution histocompatibility evaluations.

Aberrant crypt foci and colon cancer: comparison between a short- and medium-term bioassay for colon carcinogenesis using dimethylhydrazine in Wistar rats

Aberrant crypt foci (ACF) in the colon of carcinogen-treated rodents are considered to be the earliest hallmark of colon carcinogenesis. In the present study the relationship between a short-term (4 weeks) and medium-term (30 weeks) assay was assessed in a model of colon carcinogenesis induced by dimethylhydrazine (DMH) in the rat. Six-week-old male Wistar rats were given subcutaneous injections of DMH (40 mg/kg) twice a week for 2 weeks and killed at the end of the 4th or 30th week. ACF were scored for number, distribution pattern along the colon and crypt multiplicity in 0.1 percent methylene-blue whole-mount preparations. ACF were distinguished from normal crypts by their larger size and elliptical shape. The incidence, distribution and morphology of colon tumors were recorded. The majority of ACF were present in the middle and distal colon of DMH-treated rats and their number increased with time. By the 4th week, 91.5 percent ACF were composed of one or two crypts and 8.5 percent had three or more crypts, while by the 30th week 46.9 percent ACF had three or more crypts. Thus, a progression of ACF consisting of multiple crypts was observed from the 4th to the 30th week. Nine well-differentiated adenocarcinomas were found in 10 rats by the 30th week. Seven tumors were located in the distal colon and two in the middle colon. No tumor was found in the proximal colon. The present data indicate that induction of ACF by DMH in the short-term (4 weeks) assay was correlated with development of well-differentiated adenocarcinomas in the medium-term (30 weeks) assay

Medium-term protocols for in vivo evaluation of chemical modifiers of carcinogenesis

Cancer development is a long-term multistep process which allows interventional measure before the clincial disease emerges. the detection of natural substances which can block the process of carcinogenesis is a important as the identification of anti-tumoral drugs since they might be used in chemoprevention of cancer in high-risk groups. In vivo rodent models of chemical caecinogenesis have been used to study plant-derived inhibitors of carcinofenesis such as indols, coumarins, isothiocyanates, flavones, phenols and allyl-sulfides. Since the standard in vivo rodent bioassay is prolonged and expensive, shorter reliable protocols are needed. Two in vivo medium-term protocols for evaluation of modifiers of carcinogenesis are presented, one related to liver and the other to bladder cancer. Both protocols use rats, last 8 and 36 weeks and are based on the two-step concept of carcinogenesis: initiation and promotion. The protocols use respectively the development of altered foci of hepatocytes expressing immunochistochemically the placental form of gluthation S-transferase and the appearence of pre-neoplastic urothelium and papillomas as the "end-points". the use of these protocols for detection of plantpderived inhibitors of carcinogenesis appear warranted.

Lesöes histológicas da mucosa vesical em 91 autópsias / Histological lesions of the vesical mucosa in 91 autopsies

As bexigas de 91 autópsias foram estudadas histologicamente para se avaliar a freqüência e a distribuiçäo anatômica de alteraçöes uroteliais proliferativas. Sessenta e sete (74%) dos casos apresentaram pelo menos uma das lesöes estudadas, sendo os ninhos de Brünn a lesäo mais freqüente (60%), seguida de "cistite" glandular (45%) e metaplasia escamosa (24%). Todas as lesöes foram mais freqüentes no trígono vesical. Ninhos de Brünn e "cistite" glandular ocorreram em todas as faixas etárias e indiferentemente nos dois sexos, sendo mais freqüentes acima dos 15 anos de idade, quando ocorreram no sexo masculino. A metaplasia escamosa foi alteraçäo observada só acima dos 15 anos de idade, em 70 a 100% das mulheres e somente em 3 a 12% dos homens. frente à baixa freqüência do carcinoma de bexiga em nosso meio, näo há razäo para considerar estas alteraçöes epiteliais täo ubíquas como lesöes pré-neoplásicas

Citodiagnóstico urinário de carcinoma näo-papilipero "in situ" em paciente de alto risco / Urinary cytodiagnosis from \"in situ\" non-papilliferous carcinoma in high risk patient

A elevada taxa de recorrência do câncer de bexiga é parcialmente devida a processo neoplasico multifocal do urotélio, concomitante ou posterior ao diagnóstico da primeira lesäo tumoral. Esta observaçäo justifica o seguimento rigoroso dos pacientes após ressecçäo parcial destas neoplasias. Os autores relatam umc caso de carcinoma "in situ" näo-papilífero de bexiga, detectado pelo exame citológico da urina três anos após ressecçäo de carcinoma papilífero. Depois de discutir este encontro de lesäo urotelial pré-invasiva näo papilífera em paciente de alto rico e apontar a concomitância com hiperplasia nodular depróstata, os autores salientam a eficiência do escrutínio citológico na populaçäo de alto risco para neoplasia vesical