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Hepatitis B virus (HBV) has a low endemicity in Rio de Janeiro, Brazil. Sexual transmission must play an important role in this virus, but the prevalence and risk factors have never been properly investigated. The aim of this paper is to determine the prevalence and risk factors for HBV infection in patients attending a Sexually Transmitted Diseases Clinic of the Universidade Federal Fluminense, from the State of Rio de Janeiro, Brazil. In a retrospective study, HBV seroprevalence was investigated in 440 patients. Serum of each patient was assayed for antibodies against hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg) and antibodies against hepatitis B surface antigen (anti-HBs). Demographic and risk factor data were extracted from clinic notes. The overall seroprevalence of exposure markers for HBV (anti-HBc, HBsAg and anti-HBs) were 13%, 3.4% and 8.5% respectively. Homo/bisexual behaviour, anal intercourse, HIV infection, positive serology for syphilis and blood transfusion were predictors of the HBV exposure. Among demographic data, age and place of birth were associated with the anti-HBc seropositivity.

Objectives: A study was conducted to determine the prevalence of HPV infection in cervical lesions of Brazilian women and to search for specific risk factors associated to progression to malignancy., Methods: Five hundred and fourteen paraffin-embedded biopsies obtained from female cervical lesions were classified according to the Bethesda System in low grade squamous intraepithelial lesion (LSIL), high grade SIL (HSIL) and squamous cell carcinoma (SCC). Specimens were tested for the presence of human papillomavirus (HPV) types 6/11,16/18 and 31/33/35 DNA using non-isotopic in situ hybridization., Results: HPV prevalence ranged from 85.6% in LSIL to 55.2% in SCC. Patients were analysed through an 8 year period: 27. 1% of the lesions spontaneously regressed while 43.6% persisted and 29.3% progressed to carcinoma. High risk types were present in 80.5% (Crude OR 13.8, P=0.0003) of the progressive lesions. Possible co-factors have also been evaluated: history of other sexually transmitted diseases, mainly syphilis, showed to be positively related to progression (Adjusted OR 13.0, P=0.0003) while oral contraceptive use and tobacco smoking were not significantly related to it (P>O.1). Association of two or more co-factors also proved to be related to progression., Conclusions: Oncogenic HPV types 16 and 18 and history of other concurrent sexually transmitted diseases were found to be significantly associated with progression to cancer. Smoking and the use of oral contraceptives did not show a relation to cancer establishment, but when they were associated a significant co-operative role in progression was demonstrated. Our study indicated that HPV and other risk factors for cancer can act together, corroborating the observation of a poor prognosis for Brazilian women presenting SILs.

Two hundred and thirty paraffin-embedded biopsies obtained from female cervical lesions were tested for the presence of human papillomavirus (HPV) types 6/11, 16/18 and 31/33/35 DNA using non-isotopic in situ hybridization. Specimens were classified according to the Bethesda System in low grade squamous intraepithelial lesion (LSIL), high grade SIL (HSIL) and squamous cell carcinoma (SCC). HPV prevalence ranged from 92.5% in LSIL to 68.5% in SCC. Benign types were prevalent in LSILs while oncogenic types infected predominantly HSILs and SCC. HPV infection showed to be age-dependent, but no significant relation to race has been detected. Patients were analyzed through a five-year period: 20.7% of the lesions spontaneously regressed while 48.9% persisted and 30.4% progressed to carcinoma. Patients submitted to treatment showed a 19.4% recurrence rate. High risk types were present in 78.6% (CrudeOR 13.8, P = 0.0003) of the progressive lesions, and in 73.7% of the recurrent SILs (COR 19.3, P = 0.0000001). Possible co-factors have also been evaluated: history of other sexually transmitted diseases showed to be positively related either to progression (Adjusted OR 13.0, P = 0.0002) or to recurrence (AOR 17.2, P = 0.0002) while oral contraceptive use and tobacco smoking were not significantly related to them (P > 0.1). Association of two or more co-factors also proved to be related to both progression and recurrence, indicating that they may interact with HPV infection in order to increase the risk of developing malignant lesions.

Unlabelled: In order to investigate genital papillomavirus infection in a university hospital, we verified that condyloma acuminata and epidermoid carcinoma were the most common diseases associated to this virus., Purpose: This study was undertaken to verify the prevalence of genital lesions associated to papillomavirus and sex, age and race distribution., Methods: We have reported 223 patients who were treated at Hospital Universitario Antonio Pedro, Rio de Janeiro State, during the period 1988-1992. After clinical diagnosis, biopsies were submitted to histological analysis., Results: Results showed that condyloma acuminata and epidermoid carcinoma were the most frequent lesions among genital lesions. Carcinoma cases had a stable prevalence along the period while condyloma cases had a significant increase. Both lesions were more frequently found in Caucasian (white) patients. There were no differences between sexes and condyloma evidence. The media age in the epidermoid carcinoma cases did not change in the years, but it has decreased regarding condyloma acuminata., Conclusion: Genital diseases associated to papillomavirus increased during five years. Attention must be paid to control and early diagnosis to prevent neoplasic evolution.

In a previous report curing of prophage in Staphylococcus aureus by treatment with 8-methoxypsoralen plus near-UV (365 nm) radiation was described. In the present work the use of angelicin and 4,5',8-trimethylpsoralen and repeated irradiation show that monoadducts and DNA interstrand cross-links formed by furocoumarin photoaddition are involved in the curing of the prophage responsible for the suppression of the lipolytic activity in a putative repair proficient strain of Staphylococcus aureus.

A hundred-sixty paraffin-embedded specimens from female cervical lesions were examined for human papillomavirus (HPV) types 6, 11, 16 and 18 infections by non-isotopic in situ hybridization. The data were compared with histologic diagnosis. Eighty-eight (55%) biopsies contained HPV DNA sequences. In low grade cervical intraepithelial neoplasias (CIN I), HPV infection was detected in 78.7% of the cases, the benign HPV 6 was the most prevalent type. HPV DNA was detected in 58% of CIN II and CIN III cases and in 41.8% of squamous cell carcinomas (SCC). Histologically normal women presented 20% of HPV infection. Oncogenic HPV was found in 10% of these cases, what may indicate a higher risk of developing CINs and cancer. Twenty-five percent of the infected tissues contained mixed infections. HPV 16 was the most common type infecting the cervix and its prevalence raised significantly with the severity of the lesions, pointing its role in cancer pathogenesis. White women presented twice the cervical lesions of mulatto and African origin women, although HPV infection rates were nearly the same for the three groups (approximately 50%). Our results showed that HPV typing by in situ hybridization is a useful tool for distinguishing between low and high risk cervical lesions. Further studies are required to elucidate risk factors associated with HPV infection and progression to malignancy in Brazilian population.

Detection of papillomavirus DNA in situ hybridization technique was performed in 29 symptomatic patients (6 males and 23 females) during the period of 1989-1991 at the Clinic for Sexually Transmitted Diseases, Universidade Federal Fluminense, State of Rio de Janeiro. All the male patients had condyloma acuminata. Only HPV 6/11 were found in these lesions. Clinical features in the female patients included vulvar condyloma acuminata, bowenoid papulosis, flat cervical condyloma, cervical condyloma acuminatum and cervical intraepithelial neoplasia grade II (CIN II). We also found cases of condyloma acuminata associated to vulvar intraepithelial neoplasia grade III (VIN III), as well as to vaginal invasive carcinoma. HPV 6/11 and 16/18 were found in vulvar condyloma acuminata. Mixed infection by 6/11-16/18 HPV were also seen in these lesions as well as in the patient who had cervical condyloma acuminatum. HPV 16/18 were found in the condyloma acuminatum plus VIN III and in the CIN II lesions. We have found HPV 31/33/51 in the specimen of condyloma acuminatum plus invasive carcinoma. In order to investigate the ultrastructural aspects of HPV infection in genital tissue, the biopsies of three female patients were observed under electron microscope. Mature virus particles were found in the cells of a condyloma acuminatum as well as in the condyloma acuminatum plus invasive carcinoma case. In another sample, chromosome breakages were found in the nuclei of the infected cells although no viral particles were observed.

Laboratory studies were carried out on 3178 patients with signs and symptoms suggestive of dengue infection from April 1986 to December 1987 in the State of Rio de Janeiro, Brazil. The epidemic had two peaks following the first virus isolation and affected the inhabitants of 17 counties. Both sex and all age groups were affected. Dengue virus type 1 was isolated from 1039 sera and the number of confirmed cases was increased to 1874 (59%) by MAC-ELISA. Isolation rate confirmed cases reached 80% in the specimens obtained until the 4th day after the onset of disease and viraemia ranged from 10(3.0) to 10(8.5) TCID50/ml.

The appearance and persistence of IgM antibodies were studied by MAC-ELISA in 926 confirmed cases of dengue virus type 1 infection. Assays performed on acute and convalescent patient sera revealed that IgM antibodies appeared during the early phase of disease (day 2) and persisted for three months after onset. MAC-ELISA proved to be a valuable early diagnosis test when compared with haemagglutination inhibition.

It was observed that sialic acid and macromolecules rich in this sugar were able to inhibit the hemagglutination activity (HA) of Bacteroides fragilis strains in low concentrations. Reversion of the HA and also of the adsorption to beads of Sepharose coupled to bovine submaxillary mucin, by this sugar residue corroborated the recognition capacity of the bacterial lectin-like adhesin. However, when erythrocytes were treated with clostridial neuraminidase, an increase in the HA of some strains was observed. Protease treatment of erythrocytes abolished the HA, indicating that cell receptors of B. fragilis are probably a glycoprotein moiety.

An evaluation of the IgM antibody immune response against yellow fever using strain 17D was carried out by MAC-ELISA and PRNT. The results showed an agreement of 97% between both tests and the authors conclude that MAC-ELISA can be used as a specific and sensitive assay to replace the PRNT for detecting yellow fever antibodies in human sera, after vaccination programs.

The effects of subinhibitory concentrations of metronidazole on the general morphology, ultrastructure and charge and hydrophobicity of Bacteroides fragilis were investigated using transmission and scanning electron microscopy, and measurements of zeta-potentials and contact angles. Metronidazole treatment induced morphological alterations in B. fragilis. Cells became filamentous and showed a significant loss of cytoplasm. The surface anionogenicity and hydrophobicity of B. fragilis were enhanced by the drug treatment. Metronidazole, by modifying B. fragilis surface properties, could alter, indirectly, interactions with host cells.

This paper presents the evaluation of an enzyme immunoassay in which Mayaro virus-infected cultured cells are used as antigen (EIA-ICC) and an IgM antibody capture ELISA (MAC-ELISA) for Mayaro serologic diagnosis using 114 human sera obtained during a Mayaro outbreak occurred in Bolivia, in 1987. Results were compared with those obtained by haemagglutination-inhibition test (HAI). MAC-ELISA was the most sensitive technique for anti-Mayaro IgM detection. MAC-ELISA was twice as sensitive as IgM EIA-ICC. The data shows that MAC-ELISA is a practical and valid technique for diagnosis of recent Mayaro infection. IgG EIA-ICC showed high sensitivity and high specificity compared to HAI. The combination of anti-Mayaro IgG and IgM EIA-ICC results presented the highest sensitivity of the study. Anti-Mayaro IgG and IgM simultaneous detection by EIA-ICC can be used for recent infection diagnosis (in spite of a less sensitive IgM detection than by MAC-ELISA), for surveillance and sero-epidemiologic studies, and for studies of IgG and IgM responses to Mayaro infection.