No abstract

A B S T R A C TObjectives: This study was performed to determine whether neutralizing antibodies against yellow fever virus (YFV) generated by YFV vaccine could interfere in the specificity of dengue virus (DENV) and Zika virus (ZIKV) IgG ELISA tests. Methods: Seventy-nine pairs of serum samples (pre-and post-vaccination), collected during the years 1997-1998 from children with no history of yellow fever disease who had been vaccinated against YFV, were tested. The seroconversion post-vaccination was evaluated through plaque reduction neutralization test (PRNT), and four different commercial ELISA kits were used for the detection of DENV and ZIKV IgG antibodies. Results: A cross-reactivity rate of 3.9% with DENV IgG antibodies was found only with the Dengue Virus IgG Dx Select kit (Focus Diagnostics). Conclusions: As several countries have local transmission of multiple arboviruses, the absence of crossreactivity or minimum cross-reactivity of YFV neutralizing antibodies with DENV and ZIKV antigens is a relevant finding, since the interpretation of sero-epidemiological investigations would be seriously impacted in many regions where YFV vaccination is mandatory.

Invasive cervical cancer (ICC) is the third most frequent cancer among women worldwide and is associated with persistent infection by carcinogenic human papillomaviruses (HPVs). The combination of large populations of viral progeny and decades of sustained infection may allow for the generation of intra-patient diversity, in spite of the assumedly low mutation rates of PVs. While the natural history of chronic HPVs infections has been comprehensively described, within-host viral diversity remains largely unexplored. In this study we have applied next generation sequencing to the analysis of intra-host genetic diversity in ten ICC and one condyloma cases associated to single HPV16 infection. We retrieved from all cases near full-length genomic sequences. All samples analyzed contained polymorphic sites, ranging from 3 to 125 polymorphic positions per genome, and the median probability of a viral genome picked at random to be identical to the consensus sequence in the lesion was only 40%. We have also identified two independent putative duplication events in two samples, spanning the L2 and the L1 gene, respectively. Finally, we have identified with good support a chimera of human and viral DNA. We propose that viral diversity generated during HPVs chronic infection may be fueled by innate and adaptive immune pressures. Further research will be needed to understand the dynamics of viral DNA variability, differentially in benign and malignant lesions, as well as in tissues with differential intensity of immune surveillance. Finally, the impact of intralesion viral diversity on the long-term oncogenic potential may deserve closer attention.

Evaluate expression and amplification of EGFR in cholangiocarcinoma (CCA) and correlate with the different histological types. 74 patients with CCA from 1992 to 2017 were evaluated. Cases were classified in large duct subtype (DL), cholangiolocarcinoma (CLC), intermediate cell carcinoma (ICC) and papillary (LP).The immunohistochemistry (IHQ) was conducted in 71 cases and the amplification of EGFR was using the fluorescence in situ hybridization (FISH) in 48 cases. From the 74 patients, most lesions affected the perihilar topography (54%, 40/74), extrahepatic portion (27%, 20/74) and the least frequent was the intrahepatic (19%, 14/74). Periductal infiltrative macroscopic growth patterns 60.9% (45/74) and the mass forming 33.7% (25/74) were the predominant, intraductal pattern 5.4% (4/74) lower frequency. The DL subtype was the most frequent (66.2%, 49/74), followed by the CLC (21.7%, 16/74). The LP (8.1%, 6/74) and the ICC (4.0%, 3/74) had a lower frequency. In the IHQ, EGFR showed positivity in 80.2% (57/71), presenting moderate intensity 2+ in 55.0% (39/71) of the cases and strong intensity 3+ in 25.3% (18/71), 14 were detected as negative 19.8%. The FISH, of the 48 cases, 10.5% (5/48) were amplified by the gain in the number of copies of the EGFR gene and 89.5% (43/48) were considered negative. The amplified cases were distributed in 12.5% (4/32) of the DL subtype and 12.5% (1/8) of the CLC subtype. The IHQ expression of EGFR in the tumor is high in all histological subtypes of CCA. EGFR amplification occurred in a small portion of the DL and CLC subtypes.

pelas oportunidades, colaborações e ensinamentos ao longo destes anos que trabalhamos juntos. À Clara Felix, que me ensinou e auxiliou em muitos aspectos e que se tornou uma grande amiga durante estes anos de projetos e trabalhos. À todos os funcionários do Laboratório de Virologia do Instituto de Medicina Tropical de São Paulo pelo carinho com o qual me receberam e pelos ensinamentos que contribuíram muito para minha formação profissional. Ao Hospital de Câncer de Barretos e à Dr.ª Vanessa Almeida Pádua pela colaboração e por tornarem este trabalho possível. Ao CNPq pelo apoio financeiro para a execução deste trabalho. Aos meus pais, Maria de Fátima Souza Santiago e Souza e Carlos José de Souza, as pessoas mais importantes da minha vida, que sempre me apoiaram em todas as minhas decisões e confiaram em meu potencial. Ao meu noivo, Luís Carlos Silva Gómez Alvarez, pelo apoio, amor, compreensão e companheirismo. Às minhas amigas queridas por todos estes anos de amizade e incentivo. Meu muito obrigada à todos! Vocês foram essenciais para que esta jornada fosse concluída. Esta dissertação está de acordo com as seguintes normas, em vigor no momento desta publicação: Referências: adaptado de International Committee of Medical Journals Editors (Vancouver).