Human papillomavirus infection and p53 protein expression in vulvar intraepithelial neoplasia and invasive squamous cell carcinoma

The etiopathogenesis of vulvar intraepithelial neoplasia (VIN III) and invasive squamous cell carcinoma are largely unknown. Since there are few studies on Brazilian patients, our purpose was to determine the frequency of human papillomavirus (HPV) infection and the expression of p53 in these lesions, and associate them with other factors such as age, morphological subtypes, multicentric and multifocal disease. Thirty-eight cases of VIN III, nine of superficially invasive carcinoma, and 55 of invasive vulvar carcinoma were retrospectively evaluated from 1983 to 1995 for the presence of HPV by immunohistochemistry and in situ hybridization, and for p53 protein expression by immunohistochemistry on paraffin sections. All cases for whom material (slides and paraffin blocks) and clinical data were available were included. HPV and p53 were detected in 57.9 and 21.1% of the VIN III lesions, 33.3 and 66.7% of superficially invasive carcinomas, and 7.3 and 58.2% of invasive squamous cell carcinomas, respectively. HPV infection was associated with younger age in the VIN III and invasive carcinoma groups. In the latter, HPV infection was associated with the basaloid variant. p53 expression rate was higher in superficially invasive and invasive lesions and was not related to HPV infection. Our findings are similar to others and support the hypothesis that there are two separate entities of the disease, one associated with HPV and the other unrelated, with p53 inactivation possibly being implicated in some of the cases.

Autoantibody production in chronic idiopathic urticaria is not associated with Helicobacter pylori infection

Chronic idiopathic urticaria (CIU) is a dermatological syndrome, characterized by raised erythematous skin lesions, that affects 20% of the general population and has been associated with autoimmunity. However, some reports have also suggested a close relationship between CIU and Helicobacter pylori infection, which is endemic in developing countries and associated with chronic gastritis, peptic ulcer disease, and gastric carcinoma. In the present study, we investigated the occurrence of autoantibodies in sera from 23 CIU subjects infected with H. pylori and from 23 CIU subjects without this infection. The presence of anti-thyroid antibodies was determined by indirect hemagglutination assay and the presence of autoantibodies to IgE and C1INH was determined by ELISA. Antibodies to thyroid antigens were detected at low titers from 100 to 400 in three of 23 (13%) CIU-infected subjects and in four of 23 (17%) CIU-noninfected subjects. The titers of anti-IgE autoantibodies were similar in these CIU groups, presenting absorbances of 1.16 ± 0.09 and 1.07 ± 0.16, respectively, while a titer of 1.14 ± 0.15 was detected in the healthy control group. The concentration of anti-C1INH autoantibodies was the same in the CIU-infected and -noninfected subjects (7.28 ± 1.31 and 7.91 ± 2.45 ng/ml, respectively), and was 7.20 ± 2.25 ng/ml in the healthy control group. However, the serum levels of complexed anti-C1INH antibodies were increased in CIU-infected subjects compared to CIU-noninfected subjects and healthy controls with an absorbance of 1.51 ± 0.21 vs 1.36 ± 0.16 and 1.26 ± 0.23, respectively (P < 0.05), indicating an impaired clearance of immune complexes in CIU-infected patients. In conclusion, no correlation was observed between H. pylori infection and autoantibody production in CIU patients consistent with reports of clinical studies.

Measurement of Ki-67 antigen in 159 pituitary adenomas using the MIB-1 monoclonal antibody

Pituitary adenomas sometimes show rapid growth and recurrence, and about one third invade the structures surrounding the sella turcica. In an attempt to determine aggressive behavior at an early stage, we used the MIB-1 antibody to identify the Ki-67 antigen. The present study was designed to evaluate pituitary adenomatous tissue in terms of secretion and proliferation and to correlate the Ki-67 index with hormone phenotype and invasive behavior. Material from 159 patients submitted to one or more resections of pituitary adenomas was evaluated. Forty-two non-secretory adenomas and 43 adenomas immunoreactive for growth hormone, 19 for prolactin, 18 for growth hormone and prolactin, 16 for adrenocorticotropic hormone (ACTH), and 21 cases of plurihormonal/gonadotropin adenomas were detected by immunohistochemistry. The MIB-1 antibody was positive in 139 samples and the Ki-67 index ranged from 0.16 to 15.48% (mean = 1.22 ± 2.09%), with no significant difference between genders, age groups, or secretory and non-secretory status. The Ki-67 index was higher in ACTH-secreting adenomas. Invasive pituitary adenomas had a significantly higher Ki-67 index (2.01 ± 3.15%) than macroadenomas with or without supra-sellar extension (1.12 ± 1.87%; P = 0.02). The index was not significantly different in the subgroup of adenomas with invasion of the cavernous sinus compared to groups with other types of invasion. We conclude that tumoral proliferative activity evaluated by the detection of the Ki-67 antigen is significantly higher in invasive than noninvasive adenomas, information which can be useful in therapeutic postoperative management since index cut-off values associated with aggressive behavior can be established.

Noroviruses associated with acute gastroenteritis in a children's day care facility in Rio de Janeiro, Brazil

Noroviruses (Norwalk-like viruses) are an important cause of gastroenteritis worldwide. They are the most common cause of outbreaks of gastroenteritis in the adult population and occur in nursing homes for the elderly, geriatric wards, medical wards, and in hotel and restaurant settings. Food-borne outbreaks have also occurred following consumption of contaminated oysters. This study describes the application of a reverse transcription-polymerase chain reaction (RT-PCR) assay using random primers (PdN6) and specific Ni and E3 primers, directed at a small region of the RNA-dependent RNA polymerase-coding region of the norovirus genome, and DNA sequencing for the detection and preliminary characterisation of noroviruses in outbreaks of gastroenteritis in children in Brazil. The outbreak samples were collected from children <5 years of age at the Bertha Lutz children's day care facility at Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, that occurred between 1996 and 1998, where no pathogen had been identified. At the Bertha Lutz day care center facility, only Fiocruz's employee children are provided for, and they come from different social, economic and cultural backgrounds. Three distinct genogroup II strains were detected in three outbreaks in 1997/98 and were most closely related to genotypes GII-3 (Mexico virus) and GII-4 (Grimsby virus), both of which have been detected in paediatric and adult outbreaks of gastroenteritis worldwide.