Thirty years after the first HIV case in French Guiana, the drivers of the epidemic are not clearly known, but the epidemic is usually conceptualized as generalized. Cross-linking results from a study in the general population and a study in the HIV-infected population in Cayenne suggests that in the general population of HIV-positive men, 45% of HIV cases are attributable to having sex with someone they paid. Similarly, for HIV-positive women exchanging sex for presents or money, 10.7% of HIV cases are attributable to transactional sex. A surprising finding was that 16.8% of HIV patients had tried crack cocaine before. On the Maroni river, the female-biased sex ratio suggests the drivers in that remote area may be related to cultural polygyny. These observations have important consequences on communication and prevention strategies.

No abstract

Considering the importance of BRCA1, BRCA2, CHEK2 and TP53 in the development of hereditary early-onset breast and ovarian cancer and that the genetic susceptibility profile of the Northeast population from Brazil has never been analyzed, this study aimed to verify the frequency of mutations of clinical significance in these genes in high-risk hereditary breast and ovarian cancer (HBOC) syndrome patients from that region. DNA samples from 106 high-risk unrelated patients mostly from Bahia, the biggest state in the Northeast region, were analyzed. These patients underwent full BRCA1 gene sequencing, screening for common founder mutations in the BRCA2, CHEK2 and TP53 genes and genetic ancestry analysis with nine ancestry informative markers. The positive results were confirmed by two sequencing reactions. Three mutations of clinical significance were found: BRCA1 p.R71G (4.71%), 3450del4 (3.77%) and TP53 p.R337H (0.94%). The genetic ancestry analysis showed a high European ancestry contribution (62.2%) as well as considerable African (31.2%) and Amerindian (6.6%) ancestry contributions (r2=0.991); this degree of heterogeneity was also significant in the population structure analysis (r=0.604). This population is highly admixed with a different spectrum of genetic susceptibility, with the Galician founder mutation BRCA1 p.R71G accounting for 50% of all identified mutations in high-risk HBOC patients. TP53 p.R337H was also significantly frequent; thus, the combined screening of BRCA1/2 and TP53 should be offered to high-risk HBOC patients from Northeast Brazil.

Previous data suggest that Salvador, the capital of the State of Bahia, a northeastern state of Brazil, has the highest prevalence of HTLV infection in blood donors among Brazilian cities. The aim of this case-control study was to identify the determinants of risk for HTLV infection among blood donors in the city of Salvador. Between January 2000 and December 2003, 504 blood donors with positive screening tests for HTLV infection (unconfirmed prevalence of 0.48%) were invited to participate in our study. A total of 154 had performed a Western Blot (WB) test, 139 were of which found to be positive (false positive screening rate 9.9%). Using a standardized questionnaire, a single interviewer obtained information on demographic, socioeconomical and educational characteristics, as well as sexual behavior from 91 out of the 139 positive by WB and from 194 HTLV-negative blood donors. Prevalence of HTLV infection was 0.48%. Multivariate analysis revealed women (OR 3.79 [1.61-8.88], p=0.002), low family income* (OR 3.37 [1.17-9.66], p=0.02), self-reported history of sexual transmitted diseases (OR 6.15 [2.04-18.51], p=0.001), 2 or more sexual partners during life (OR 9.29 [2.16-39.94], p=0.0020) and inconsistent use of condoms (OR 4.73 [1.98-11.26], p=0.0004) as risk factors for HTLV infection. In accordance with previous published data, our results point to an association between low socio-economical level, poor education and unsafe sexual behavior with HTLV infection. We observed a lower prevalence of HLTV infection when compared to previous data.

No abstract

The applicability of FISH is clear, particularly for residual disease detection. Classical and molecular cytogenetics are complementary methods.

No abstract

Chronic lymphocytic leukemia (CLL) presents a varying incidence of karyotypic abnormalities whose detection is complicated by difficulties in obtaining mitosis for analysis in this type of mature lymphocyte disorder. Since the introduction of molecular cytogenetics (FISH = fluorescent in situ hybridization), applying centromeric probes for chromosome 12 has made it possible to detect a higher percentage of trisomy 12 cases. The objective of the present study was to detect trisomy 12 by FISH (alpha satellite probe) in 13 patients with CLL whose karyotypes by G-banding were either normal or inadequate. Using this method trisomy 12 was detected in three patients in a percentage of positive cells varying from 55.5% to 79%, showing that FISH is a sensitive and highly specific method for trisomy detection and should be routinely performed when the karyotype is normal.
A leucemia linfocítica crônica (CLL) apresenta incidência variável de anomalias de cariótipo devido às dificuldades em se obter mitose para análise. Desde a introdução da citogenética molecular (FISH = hibridação in situ por fluorescência) usando sonda centromérica para o cromossomo 12 foi possível detectar uma maior porcentagem de casos com trissomia 12. O objetivo deste trabalho foi de detectar trissomia 12 por FISH (sonda alfa satélite) em 13 pacientes com CLL cujos cariótipos por banda G haviam sido normais ou sem resultado. Três pacientes apresentaram trissomia 12 por este método com uma porcentagem de células trissômicas variando de 55,5 a 79%, demonstrando que a FISH é um método sensível e altamente específico para detecção de trissomia 12