Oral carcinoma epidemiology in Paraná State, Southern Brazil / Epidemiologia do câncer bucal em pacientes do Estado do Paraná, Sul do Brasil

Oral carcinoma is the sixth most frequent type of cancer in the world and the seventh most common in Brazil (the country with the highest incidence in Latin America). Mean five-year survival remains one of the lowest among the main cancers, thus justifying studies that contribute to the development of preventive strategies. The aim of this study was to compare the epidemiological, clinical, and histological characteristics of 91 patients with oral carcinoma. Mean age was 58.62 ± 10.46 years, and male-to-female ratio was 6.6:1.0 (79 men and 12 women). European descendants predominated with 79 patients (86.8 percent). Eighty-five individuals (93.4 percent) smoked and 70 (76.9 percent) consumed alcohol regularly. Anatomical distribution of tumors was: 27 (29.7 percent) tongue; 18 (19.8 percent) floor of mouth; 11 (12.1 percent) oropharynx; and 11 (12.1 percent) oral mucosa. Fifty-seven patients (62.6 percent) presented lymph node involvement and three (3.3 percent) had distant metastases. Surgery and radiotherapy were used in 43.2 percent of patients. With the exception of the male/female ratio (which was higher), our data are consistent with previous studies on oral carcinoma patients.

O carcinoma bucal é o sexto tipo mais comum de câncer no mundo e o sétimo no Brasil, onde ocorre a maior incidência da América Latina. A sobrevida média de aproximadamente cinco anos permanece como uma das menores entre os principais cânceres, justificando estudos que auxiliem no delineamento de estratégias de prevenção. Este estudo objetivou avaliar em uma amostra de 91 pacientes portadores de carcinomas bucais características epidemiológicas; fatores de risco, clínicos e histopatológicos. A média de idade foi de 58,62 ± 10,46 anos e a razão sexual de 6,6:1,0 (79 homens e 12 mulheres). A etnia euro-descendente foi predominante com 79 (86,8 por cento) pacientes. Oitenta e cinco (93,4 por cento) indivíduos eram tabagistas e 70 (76,9 por cento) etilistas. As localizações anatômicas prevalentes foram: 27 tumores (29,7 por cento) de língua; 18 (19,8 por cento) de assoalho; 11(12,1 por cento) de orofaringe e 11 (12,1 por cento) de mucosa. Cinqüenta e sete (62,6 por cento) pacientes apresentaram os linfonodos comprometidos e três apresentaram (3,3 por cento) metástases à distância. A maioria dos pacientes (43,2 por cento) recebeu tratamento cirúrgico e radioterápico. Com exceção da proporção sexual, nossos dados concordam com os freqüentemente descritos para portadores de carcinomas bucais.

Population analysis of xenobiotic metabolizing genes in South Brazilian Euro and Afro-descendants

Individual variability in xenobiotic metabolism has been associated with susceptibility to developing complex diseases. Genes involved in xenobiotic metabolism have been evaluated in association studies; the difficulty of obtaining accurate gene frequencies in mixed populations makes interpretation of the results difficult. We sought to estimate population parameters for the cytochrome P450 and glutathione S-transferase gene families, thus contributing to studies using these genes as markers. We describe the frequencies of six genes (CYP1A1, CYP2D6, CYP2E1, GSTM1, GSTT1, and GSTP1) and estimate population parameters in 115 Euro-descendants and 196 Afro-descendants from Curitiba, South of Brazil. PCR-based methods were used for genotyping, and statistical analysis were performed by AMOVA with ARLEQUIN software. The mutant allele frequencies in the Afro-descendants and Euro-descendants, respectively, were: CYP1A1*2A = 30.1 percent and 15.2 percent; CYP2D6*4 = 14.5 percent and 21.5 percent; CYP2E1*5B = 7.9 percent and 5 percent; GSTP1*B = 37.8 percent and 28.3 percent. The null genotype frequencies were: GSTM1*0 = 36.8 percent and 46.1 percent; GSTT1*0 = 24.2 percent and 17.4 percent.

Microsatellite studies on an isolated population of African descent in the Brazilian state of Bahia

The African descent population of the Bananal community in the Brazilian state of Bahia (BA) was characterized as a genetic isolate and analyzed for some short tandem repeat (STR) microsatellite autosomic polymorphic loci (CSF1PO, TH01, TPOX, F13A1, FESFPS and vWA). These genetic variants were further compared to data obtained from an urban sample from the town of Jequié (BA) regarding demographic and anthropogenetic aspects. The Bananal sample comprised 32 unrelated individuals whereas Jequié was represented by 76 individuals. The Bananal Negroid Phenotypic Index (NPI) was 0.98 and the Negroid Cultural Index (NCI) 0.24. Consanguineous marriages occurred at a frequency of 34.61 percent and the F value was 0.0126. All six loci studied were in Hardy-Weinberg Equilibrium (p > 0.05). The genotypic and allele frequencies of the CSF1PO and vWA loci were similar. In the Bananal population the genic diversity of the THO1 locus was 66.8 percent and that of the F13A1 locus was 83.7 percent. The estimated ethnic racial admixture was 81 percent African and 19 percent Amerindian. The multiple correlation coefficient (R²) indicated adequate adaptation (99 percent). Total genetic variation for the six loci was 82.9 percent with an index of 6.7 percent for population subdivision (G ST' = 0.067). Anthropologic data and results obtained from the allele frequencies of the loci studied are indicative of a genetic isolate in Bananal, reminiscent of the a 'quilombo community' (i.e. one founded by run away slaves).

Unexpected chromosomal alterations in Tayassu tajacu (Artiodactyla: Tayassuidae) in captivity

Os animais silvestres têm sido utilizados como bioindicadores quando o ambiente é exposto a estressores químicos. Em geral, os agentes químicos podem induzir às alterações cromossômicas dos tipos falhas e quebras. Tayassu tajacu, é uma espécie aparentada dos porcos verdadeiro e apresenta uma grande estabilidade cariotípica. As únicas alterações descritas são em relação a forma do cromossomo X. Foram observadas falhas e quebras cromossômicas durante as análise citogenética. Estas alterações foram detectadas em cromossomos autossômicos. Levantamentos realizados na literatura associados as dados observados nos exemplares estudados, indicam um vermífugo, a base de ivermectina, como o possível causador dessas alterações cromossômicas.