Sulfated fucan from marine alga inhibits HeLa cells infection by HTLV-1 free particles: semi-quantitative analysis

A sulfated fucan from Laminaria abyssalis marine alga prevented the interaction of HTLV-1 particles, purified from the MT-2 cell line, with HeLa cells. The infection obtained using a concentrated virus suspension was detected only by amplification of the newly synthesized HTLV-1 proviral cDNA by the nested-polymerase chain reaction (PCR). The sulfated polysaccharide was not toxic to the cells at a concentration of 100 µg/mL and prevented infection by the viral particles when added to the cell monolayers. The proviral cDNA was only detected when the sulfated polysaccharide was added to the cells three hours post-infection, indicating that the inhibitory activity occurred in the initial stages of virus-cell interaction. Our results demonstrate, for the first time, the ability of a sulfated fucan from marine algae to inhibit virus transmission through free virus particles.

Human papillomavirus and penile cancers in Rio de Janeiro, Brazil: HPV typing and clinical features

OBJECTIVE: To determine the prevalence of human papillomavirus (HPV) DNA in penile cancers in Rio de Janeiro, Brazil. MATERIALS AND METHODS: We studied, prospectively, 80 consecutive cases of patients with penile cancers who underwent surgical treatment at three different Hospitals in Rio de Janeiro between March 1995 and June 2000. Of these patients, 72 were diagnosed with invasive squamous cell carcinoma and 8 patients with verrucous carcinoma. The following parameters were observed: presence or absence of HPV DNA viral type, histological subtypes, clinical stage and overall survival. RESULTS: HPV DNA was detected in 75 percent of patients with invasive carcinomas and in 50 percent of patients with verrucous carcinomas. High risk HPVs were detected in 15 of 54 (27.8 percent) patients with HPV positive invasive tumors and in 1 of 4 (25 percent) patients with HPV positive verrucous tumors. HPV 16 was the most frequent type observed. No correlation was observed between HPV status and histological subtype (p = 0.51) as well as HPV status and stage stratification (p = 0.88). HPV status was also not significantly associated with the presence of regional metastases (p = 0.89). The overall survival was related to the presence of lymph node metastases (p < 0.0001). CONCLUSIONS: HPV infection may have contributed to malignant transformation in a large proportion of our penile cancer cases but only inguinal metastasis was a prognostic factor for survival in these patients with penile carcinoma.

Ultrastructural aspects of the human T-lymphotropic virus type I (HTLV-I) in Brazil

Nowadays, Brazil may be considered an endemic area for HTLV-I infection. Several studies showed a high incidence of HTLV-I infection among the general population and different groups such as blood donors, hemophiliacs, hematological and neurological patients. Cases of adult T-cell leukemia/lymphoma as well as tropical spastic paraparesis/HTLV-I associated myelopathy have been already described. Therefore the use of different technical approaches, to characterize Brazilian HTLV strains has become important. HTLV particles were characterized and recognized by the use of transmission electron microscopy in lymphocyte cocultures. The ultra-structural analysis revealed typical virus particles close to the lymphocyte membrane. The immunoelectron microscopy allowed the identification of the virus as HTLV, a type C oncovirus, group HTLV-BLV. The ethanol phosphotungstic acid technique showed structures similar to the virus budding process and the routine preparations have contributed to the analysis of the first virus-cell interaction events. Structures related to the endocytic route HTLV entrance are also pointed out.