Biomedical subjects

L L Villa

Publications and source records attributed to L L Villa.

At least 19 recordsLinked to original sources

PubMed2006

High sustained efficacy of a prophylactic quadrivalent human papillomavirus types 6/11/16/18 L1 virus-like particle vaccine through 5 years of follow-up.

Human papillomavirus (HPV) causes cervical, vulvar, and vaginal cancers, precancerous dysplasia, and genital warts. We report data for the longest efficacy evaluation to date of a prophylactic HPV vaccine. In total, 552 women (16-23 years) were enrolled in a randomised, placebo-controlled study of a quadrivalent HPV 6/11/16/18 L1 virus-like-particle vaccine with vaccination at months 0, 2, and 6. At regular intervals through 3 years, subjects underwent gynaecologic examination, cervicovaginal sampling for HPV DNA, serum anti-HPV testing, and Pap testing, with follow-up biopsy as indicated. A subset of 241 subjects underwent two further years of follow-up. At 5 years post enrollment, the combined incidence of HPV 6/11/16/18-related persistent infection or disease was reduced in vaccine-recipients by 96% (two cases vaccine versus 46 placebo). There were no cases of HPV 6/11/16/18-related precancerous cervical dysplasia or genital warts in vaccine recipients, and six cases in placebo recipients (efficacy = 100%; 95% CI:12-100%). Through 5 years, vaccine-induced anti-HPV geometric mean titres remained at or above those following natural infection. In conclusion, a prophylactic quadrivalent HPV vaccine was effective through 5 years for prevention of persistent infection and disease caused by HPV 6/11/16/18. This duration supports vaccination of adolescents and young adults, which is expected to greatly reduce the burden of cervical and genital cancers, precancerous dysplasia, and genital warts.

Adolescent↗

PubMed2006

Epidemiological and functional implications of molecular variants of human papillomavirus.

Human papillomavirus genomes are classified into molecular variants when they present more than 98% of similarity to the prototype sequence within the L1 gene. Comparative nucleotide sequence analyses of these viruses have elucidated some features of their phylogenetic relationship. In addition, human papillomavirus intratype variability has also been used as an important tool in epidemiological studies of viral transmission, persistence and progression to clinically relevant cervical lesions. Until the present, little has been published concerning the functional significance of molecular variants. It has been shown that nucleotide variability within the long control region leads to differences in the binding affinity of some cellular transcriptional factors and to the enhancement of the expression of E6 and E7 oncogenes. Furthermore, in vivo and in vitro studies revealed differences in E6 and E7 biochemical and biological properties among molecular variants. Nevertheless, further correlation with additional functional information is needed to evaluate the significance of genome intratypic variability. These results are also important for the development of vaccines and to determine the extent to which immunization with L1 virus-like particles of one variant could induce antibodies that cross-neutralize other variants.

Epidemiologic Studies↗

PubMed2006

Infection with human papillomaviruses of sexual partners of women having cervical intraepithelial neoplasia.

Epidemiological studies show that human papillomaviruses (HPV) are strongly related to cervical cancer and cervical intraepithelial neoplasias (CIN). Unlike the case for women, there are no consistent data on the natural history of HPV in the male population even though these viruses are prevalent in males. We carried out a prospective study to assess the prevalence of HPV in males as well as the factors that determine such infections in 99 male sexual partners of women with CIN. The genitalia of the males were physically examined and subjected to peniscopy for the collection of scrapings which were subjected to the polymerase chain reaction and restriction fragment length polymorphism to detect HPV. Of the 99 males sampled, 54 (54.5%) were positive for HPV DNA, 24% of whom presented normal peniscopy, 28% presented evident clinical lesions and 48% isolated lesions consistent with subclinical infection. In the HPV-negative group, 53% showed normal peniscopy, 4% presented evident clinical lesions and 42% isolated lesions consistent with subclinical infection. The study detected a statistically significant association (P < 0.02, Pearson chi-square test) between HPV infection and both the mean number of sexual partners which a male had during his life and the mean number of sexual partners in the year prior to testing. Viral types 6 and 11 were most frequently encountered. The study shows that infection with HPV was frequent in male sexual partners of women with CIN.

Adolescent↗

PubMed2004

Molecular evidence of tumour cell removal from salvaged blood after irradiation and leucocyte depletion.

Intra-operative autologous blood recovery offers many advantages. However, blood salvage during cancer surgery is of limited use due to the potential presence of circulating tumour cells. It was the aim of this study to show that intra-operative salvage blood can be freed of cells and cellular DNA after leucoreduction by filtration and irradiation of washed blood. Known amounts of tissue culture derived from carcinoma, melanoma and osteosarcoma were added to whole blood bags. This mixture was then submitted to washing, leucoreduction and irradiation. Samples were studied stepwise in relation to the integrity and size of DNA by the polymerase chain reaction (PCR). After filtration and irradiation, PCR targeting the beta-globin gene (268 bp amplicon) was negative. Our results were corroborated by studying plasma samples added with tumoural cells. Using PCR methodology, we showed the absence of DNA from cells in experimentally contaminated blood and plasma bags after filtration and irradiation. This experimental study is an effort to ensure the safety of intra-operative autologous transfusion.

Blood Cells↗

PubMed2003

Estrogen and progesterone receptors in human papilloma virus-related cervical neoplasia.

Estrogen (ER) and progesterone (PR) receptors in the normal uterine cervix, cervical intraepithelial neoplasia and invasive carcinoma were studied in consecutive samples from Hospital do Cáncer, São Paulo, between 1996 and 1997. Tissue was collected by removing a fragment of the tumoral area using a 5-mm diameter biopsy punch, followed by removal of a macroscopically normal area as close as possible from the tumor. Histopathological confirmation was obtained for all specimens analyzed. A total of 24 normal tissues, 17 cases of cervical intraepithelial neoplasia and 7 of invasive carcinomas were studied. The ER/PR ratio was determined by immunohistochemistry using monoclonal antibodies specific for each receptor. Adjacent tissue slides were submitted to generic PCR for human papillomavirus (HPV) DNA detection followed by typing by dot blot hybridization. About half (45.8%) of the tumors were HPV DNA positive while 29.1% of the patients were also HPV positive in their respective normal tissue. ER was negative in the tumoral epithelium of 11 HPV-positive patients (P=0.04). There was a trend in the ER distribution in normal tissue that was opposite to that from lesions, but it was not statistically significant (P=0.069). No difference in ER distribution in stromal tissues was observed between HPV-positive and HPV-negative tissues. PR staining was negative in the epithelium of all cases studied. The results obtained from this small number of cases cannot be considered to be conclusive but do suggest that factors related to viral infection affect the expression of these ER/PR cervix receptors.

Adult↗

PubMed2003

Human papillomavirus prevalence among women with cervical intraepithelial neoplasia III and invasive cervical cancer from Goiânia, Brazil.

This study estimated the prevalence and distribution of human papillomavirus (HPV) types among women with cervical intraepithelial neoplasia (CIN) grade III and invasive cervical cancer from Goi s (Brazil Central Region). Seventy-four cases were analyzed and consisted of 18 CIN III, 48 squamous cell carcinomas, 4 adenocarcinomas, 1 adenosquamous carcinoma and 3 undifferentiated carcinomas. HPV-DNA sequences were examined in formalin-fixed and paraffin-embedded tissues using primers from L1 region GP5+/GP6+. Polymerase chain reaction products were typed with dot blot hybridization using probes for HPV 16, 18, 31, 33, 45, 54, 6/11, 42/43/44, 51/52, 56/58. The prevalence of HPV was estimated to be 76% (56/74). HPV 16 was the most frequently found type, followed by HPV 33, 18 and 31. The prevalence of untyped HPV was 6%; 79% percent of the squamous cell carcinoma cases and 61% percent of the CIN III were positive for HPV and the prevalence rate of HPV types was the same for the total number of cases. According to other studies, HPV type 16 is the most prevalent virus in all Brazilian regions, but there is variation regarding to other types. Type 18 is the second most prevalent HPV in North, Southeast and South Brazil regions and types 31 and 33 are the second most prevalent HPV in Northeast and Central Brazil, respectively.

Adult↗

PubMed2003

Detection of oncogenic human papillomavirus in sporadic retinoblastoma.

PURPOSE: To investigate the presence of human papillomavirus (HPV) DNA in tumour tissue from patients with unilateral retinoblastoma. METHODS: Samples of paraffin-embedded tumour tissue from 43 children with unilateral retinoblastoma were collected to investigate the presence of HPV DNA using polymerase chain reaction (PCR) and dot blot hybridization. RESULTS: Oncogenic HPV DNA types 16 and 35 were detected in 12 (27.9%) of 43 tumour specimens. A higher frequency of differentiated tumours (63.3%) was observed among the HPV-positive tumours. CONCLUSIONS: Future studies are necessary to demonstrate an association between HPV and sporadic retinoblastoma.

Child, Preschool↗

PubMed2003

Epidemiologic correlates of antibody response to human papillomavirus among women at low risk of cervical cancer.

A population at low risk for developing cervical cancer in Southern Brazil was studied to identify the main determinants of serological response to human papillomavirus (HPV). Enzyme-linked immunosorbent assay tests were performed in 976 women to detect serum IgG antibodies against HPV 16 L1 virus-like particles (VLPs) and HPVs 16, 18, 6 and 11 L1 VLPs as a mixture of antigens. Women with four or more sexual partners were more likely to be seropositive than women with one partner (HPV 16 serology odds ratio [OR]=3.06, 95% confidence interval [CI]: 2.0-4.8; HPV 6/11/16/18 serology OR=4.64, 95% CI: 3.0-7.2). HPV DNA and both serological responses were associated. Those positives to HPV 16 serology were twice as likely to have a cytological diagnosis of squamous intraepithelial lesions (SILs) than seronegatives (OR=2.07; 95% CI: 1.0-4.5, and OR=1.73; 95% CI: 0.8-3.8). Seropositivity to HPV 16 and HPV 6/11/16/18 antigens seem to be better markers of past sexual activity than current HPV infection, and humoral response to HPV 16 or HPV 6/11/16/18 may not be a strong indicator of cervical lesions in populations at low risk for cervical lesions.

Adolescent↗

PubMed2002

TRAP-silver staining, a highly sensitive assay for measuring telomerase activity in tumor tissue and cell lines.

Measurement of telomerase activity in clinically obtained tumor samples may provide important information for use as both a diagnostic marker and a prognostic indicator for patient outcome. In order to evaluate telomerase activity in tumor tissue without radiolabeling the product, we developed a simple telomeric repeat amplification protocol-silver-staining assay that is less time-consuming, is safe and requires minimal equipment. In addition, we determined the sensitivity of the silver-staining method by using extracts of telomerase-positive thyroid carcinoma cell lines which were serially diluted from 5,000 to 10 cells. Telomerase activity was also assayed in 19 thyroid tumors, 2 normal controls and 27 bone marrow aspirates. The results indicate that the technique permits the detection of telomerase activity from 5000 to as few as 10 cells. We propose that it could be immediately applicable in many laboratories due to the minimal amount of equipment required.

Biomarkers, Tumor↗

PubMed2001

Persistent human papillomavirus infection as a predictor of cervical intraepithelial neoplasia.

CONTEXT: Human papillomavirus (HPV) infection is believed to be the central cause of cervical cancer, although most of the epidemiological evidence has come from retrospective, case-control studies, which do not provide information on the dynamics of cumulative or persistent exposure to HPV infection. OBJECTIVE: To assess the risks of cervical neoplasia related to prior persistent HPV infections. DESIGN AND SETTING: Longitudinal study of the natural history of HPV infection and cervical neoplasia in women residing in the city of São Paulo, Brazil, which was conducted between November 1993 and March 1997 and involved repeated measurements of HPV and lesions with follow-up until June 2000. PARTICIPANTS: A total of 1611 women with no cytological lesions at enrollment and HPV test results available from the first 2 visits. MAIN OUTCOME MEASURE: Cervical specimens taken for Papanicolaou cytology and HPV testing every 4 months in the first year and twice yearly thereafter. Incident cervical cancer precursor lesions ascertained by expert review of all cytology smears. RESULTS: The incidence rate of squamous intraepithelial lesions (SILs) was 0.73 per 1000 women-months (95% confidence interval [CI], 0.5-0.9) among women free of HPV at the 2 initial visits and 8.68 (95% CI, 2.3-15.1) among women with HPV type 16 or 18 infections persisting over both visits. Relative to those negative for HPV oncogenic types at both initial visits, the relative risk (RR) of incident SIL was 10.19 (95% CI, 5.9-17.6) for persistent infections with any known oncogenic HPV types. The equivalent RR of incident high-grade SIL was 11.67 (95% CI, 4.1-33.3). The RRs of lesions were considerably higher for persistent infections with HPV type 16 or 18. CONCLUSION: A strong relationship exists between persistent HPV infections and SIL incidence, particularly for HPV types 16 and 18.

Adult↗

PubMed2001

Cervical coinfection with human papillomavirus (HPV) types as a predictor of acquisition and persistence of HPV infection.

Interest in coinfection with multiple types of human papillomavirus (HPV) has increased in response to the possibility of vaccination and the discovery that the host immune response appears to be mainly type specific. This study attempts to document the occurrence of coinfection with multiple HPV types and to determine whether these coinfections predicted acquisition or persistence of other HPV types in a prospective cohort of women in Brazil. Multiple HPV types were detected at the same visit in one-fifth of all women who tested positive for HPV at any time. Acquisition of an HPV infection was more likely among women with any HPV type detected on study entry. Persistence of HPV infection, the true precursor of cervical abnormalities, was independent of coinfection with other HPV types. Given the increasing prominence of HPV vaccination as a potential preventive approach, it is imperative that additional insights on cross-type protection be obtained from longer-term longitudinal investigations.

Adolescent↗

PubMed2001

Human papillomavirus as a prognostic factor in carcinoma of the penis: analysis of 82 patients treated with amputation and bilateral lymphadenectomy.

BACKGROUND: Many studies have tried to identify prognostic factors to guide the selection of patients at high risk for metastases in penile carcinoma. The authors evaluated human papillomavirus (HPV) status with respect to clinical features, incidence of metastases, and prognosis of penile carcinoma. METHODS: Human papillomavirus DNA was detected using the polymerase chain reaction on paraffin embedded material from 82 patients with penile carcinoma. The following variables were recorded: age, marital status, clinical staging, tumor surgery extension, histologic grade, tumor thickness, lymphatic and venous embolization, corpora cavernosa and corpus spongiosum infiltration, urethral infiltration, mononuclear and eosinophilic infiltrate, and lymph node spread. Follow-up ranged from 0.1 to 453 months. RESULTS: Human papillomavirus DNA was detected in 30.5% (25 of 82) of samples. HPV-16 was the most frequent type detected (13 of 25, 52%). Human papillomavirus DNA positive tumors had less lymphatic embolization by neoplastic cells than HPV negative ones (P = 0.007). The logistic regression revealed that only lymphatic embolization was related to HPV status. There was no difference, however, between HPV DNA negative and HPV DNA positive patients according to presence of lymph node metastases (P = 0.386). No difference was found in the 10-year survival rate (68.4% vs. 69.1%; P = 0.830) between the two groups. CONCLUSIONS: These data suggest that HPV status does not influence prognosis in invasive penile carcinoma.

Adult↗

PubMed2001

Expression of Ki-67 can assist in predicting recurrences of low-grade anal intraepithelial neoplasia in AIDS.

PURPOSE: The incidence of anogenital squamous-cell carcinoma was observed to have increased since the beginning of the human immunodeficiency virus infection epidemic among male homosexuals, both with acquired immunodeficiency syndrome and without acquired immunodeficiency syndrome. It seems that immunosuppression is the most important risk factor for the progression of anogenital lesions, recurrences of anal condyloma, and development of anal carcinoma, in particular in acquired immunodeficiency syndrome. High-grade anal intraepithelial neoplasia was predominantly observed in the human immunodeficiency virus-positive men. We have also observed a high rate of recurrences of anal lesions in cases of high-grade anal intraepithelial neoplasia. However, there are many cases of recurrences of low-grade anal intraepithelial neoplasia that cannot be predicted by routine histologic studies. By using immunohistochemical methods, we studied the expression of Ki-67 in epithelial cells of low-grade anal intraepithelial neoplasia of patients with acquired immunodeficiency syndrome to try to predict recurrence of these lesions. METHODS: Anal biopsies of 38 patients were studied retrospectively. Of these patients, 14 had no recurrences (Group 1), and 24 patients had recurrence of the anal lesions before one year of follow-up (Group 2). RESULTS: The median percentage of Ki-67-positive cells in Group 1 was 6.3 +/- 7.03 and in Group 2 was 24.1 +/- 16.72. The difference between Groups 1 and 2 was statistically significant (P < 0.001). CONCLUSIONS: Our results showed a high correlation between the percentage of Ki-67-positive cells and recurrences. We concluded that Ki-67 counting in low-grade anal intraepithelial neoplasia can aid in predicting recurrences and therefore aid in the follow-up of these patients.

Acquired Immunodeficiency Syndrome↗

PubMed2001

Clinicopathologic features and human papillomavirus dna prevalence of warty and squamous cell carcinoma of the penis.

Squamous cell carcinoma (SCC) accounts for 95% of penile malignant neoplasms. A subtype of SCC, named warty carcinoma (WC), is a morphologically distinct verruciform tumor with features of human papillomavirus (HPV)-related lesions. Descriptions of the behavior and histologic features of this tumor are scarce in the literature. The aim of this report is to analyze the clinicopathologic features and HPV deoxyribonucleic acid status in 60 SCCs and 11 WCs. The mean patient age was 46.5 +/- 15.9 years for WC and 52.6 +/- 12.4 years for SCC. No significant differences in age (p = 0.154) and clinical staging (T, p = 0.649; N, p = 0.497) between the two groups of tumors were found. When compared with SCCs, WCs exhibited less lymphatic embolization (p = 0.001), nodal metastasis (p = 0.019), and corpora cavernosa and corpus spongiosum infiltration (p = 0.040). Lymph node metastases were found in 34 of 60 SCC patients (56.7%) and in two of 11 WC patients (18.2%). No patients with WC tumors died of the disease compared with 19 of 60 (5-year specific survival, 66.0%) in the SCC group (p = 0.032). HPV deoxyribonucleic acid was more likely to be associated with WC (five of 11, 45.5%) than SCC (16 of 60, 26.7%), although significance was not reached (p = 0.209). The results suggest that WC is less aggressive and confers a better prognosis than typical SCC of the penis.

Adult↗

PubMed2001

Low frequency of p53 mutations in cervical carcinomas among Brazilian women.

Human papillomavirus (HPV) infections of the high-risk types are strongly linked to the development of cervical carcinoma. The HPV oncoproteins E6 and E7 are thought to play a crucial role in this process through their interactions with the p53 protein and the retinoblastoma susceptibility gene product pRb, respectively. E6 binds to p53 protein promoting its degradation. This is considered to contribute to the oncogenesis of HPV-associated anogenital cancer. On the other hand, in HPV-negative cervical carcinoma, p53 mutations are thought to have a role in the transformation process. A total of 122 HPV-positive cervical carcinoma tissue samples were evaluated for the presence of mutations in exons 5-8 of the p53 gene by single-stranded conformation polymorphism analysis and DNA sequencing. Only four missense point mutations were detected. These findings suggest that other mechanisms independent of p53 inactivation may play a role in the genesis of cervical carcinomas.

Base Sequence↗

PubMed2000

Detection of human papillomavirus in epithelial lesions of the conjunctiva.

CONTEXT: Many factors like exposure to UV radiation, climatic conditions, genetic predisposition, immunological state and, more recently, the presence of HPV have been implicated in the genesis of some lesions of the conjunctiva, especially the carcinoma. OBJECTIVE: To evaluate the presence of HPV DNA in acquired lesions of the conjunctiva and in normal mucosa. TYPE OF STUDY: Cross-sectional study. SETTING: A public university referral center (the Ophthalmology Service of the A.C. Camargo Hospital - A. Prudente Foundation, São Paulo). PARTICIPANTS: Thirty patients with acquired lesions of the conjunctiva and 60 matched controls (by age and sex) were evaluated in this study, from June 1993 to March 1995. PROCEDURES: The detection of HPV DNA in the normal conjunctiva and in acquired lesions was done by the PCR technique and dot blot hybridization. The material was collected by scraping the normal mucosa and the surface of the lesions. A fragment of fresh frozen tissue and paraffin embedded specimens of each lesion were also included. MAIN MEASUREMENTS: The association between the HPV infection and the presence or absence of conjunctival lesions. RESULTS: Sequences of HPV DNA were detected in 4 of the 31 lesions evaluated (12.9%) and in the healthy mucosa of one individual of the control group (1.6%). HPV type 16 was detected in 2 carcinomas and in the normal mucosa of one individual of the control group. HPV type 11 was demonstrated in 2 papillomas of one patient with lesions in both eyes. CONCLUSIONS: The low frequency of HPV DNA found in the lesions of this sample and the detection of the viral genome in the normal mucosa indicate that there is a weak possibility of association between HPV infection and the carcinoma of the conjunctiva.

Adolescent↗

PubMed2000

P53 polymorphism in codon 72 and risk of human papillomavirus-induced cervical cancer: effect of inter-laboratory variation.

An association between codon-72 p53 polymorphism and risk of human papillomavirus (HPV)-induced cervical cancer has been found recently, but it has been difficult to replicate. In this study, we assess the impact of inter-laboratory variation in p53 genotyping on the validity of the proposed association. DNA specimens were randomly selected from 54 invasive, squamous cell carcinoma cases, 52 HPV-negative, and 39 HPV-positive controls from a previous case-control study in Brazil. Codon-72 polymorphism was blindly analyzed in three different laboratories. We calculated age- and race-adjusted odds ratios (OR) and 95% confidence intervals (CI) using logistic regression for gauging the association between p53 polymorphism and cervical cancer risk. The proportions of the Arg/Arg, Arg/Pro, and Pro/Pro genotypes varied substantially among laboratories with Kappa coefficients in the 0.49-0.63 range. When disagreement between labs was allowed, the OR for the Arg/Arg genotype, compared to other forms, was as low as 1.5 (95% CI: 0.5-3. 9). In contrast, the OR increased to 8.0 (95% CI: 2.3-28.5) after exclusion of discordant genotypes. Restricting the comparison to HPV-positive controls increased the magnitude of the relation appreciably. After exclusion of all discordant diagnoses, the OR was 21.5 (95% CI: 3.4-137.8), whereas with disagreed genotypes the association was not significant (OR = 2.9, 95% CI: 0.7-11.9). Homozygous codon-72 p53-Arg apparently confers a higher susceptibility to HPV-associated cervical tumorigenesis. However, exposure misclassification consequent to inter-laboratory variation in protocols may affect the ability to detect the association.

Adult↗

PubMed2000

Identification of a novel allele, DRB1*1340, in two Brazilian individuals.

We identified a novel HLA-DRB1 allele, named DRB1*1340 by the WHO HLA Nomenclature Committee, in two Brazilian individuals. Typing by polymerase chain reaction using sequence-specific oligonucleotide probes (PCR-SSOP) showed a DRB1*13 allele with an unusual hybridization pattern. DNA sequencing of both strands and comparison of the sequence with previously described DRB1 alleles revealed that the most similar allele is DRB1*1301, from which DRB1*1340 differs by a single nucleotide (T-->A) in exon 2, at position 127, codon 47 (Phe-->Tyr). The sequence received accession number AJ237964 from the EMBL database.

Alleles↗