PubMed Health⌕ Search

Biomedical subjects

F Xavier Bosch

Publications and source records attributed to F Xavier Bosch.

45 records · Page 3Linked to original sources
PubMed2002

Prevalence of Kaposi's sarcoma-associated herpesvirus infection in sex workers and women from the general population in Spain.

Transmission routes of Kaposi's sarcoma-associated herpesvirus (KSHV) in the general population are poorly understood. Whereas sexual transmission appears to be common in homosexual men, the evidence for heterosexual transmission is less convincing. In our study, prevalence of KSHV infection was examined among women in the Spanish general population and among sex workers. Subjects consisted of 100 prostitutes and 100 women randomly sampled from the general population and age-matched to the prostitutes. Women had a personal interview and gynecologic examinations in which a blood sample, cervical cells and oral cells were obtained. Peripheral blood mononuclear cells (PBMC), oral and cervical samples were tested for KSHV DNA by quantitative real-time PCR. Sera were tested for antibodies against human immunodeficiency virus (HIV) by ELISA and against KSHV by latent IFA and K8.1 ELISA. Women who were positive in either serologic assay or PCR were considered infected by KSHV. Human papillomavirus (HPV) DNA in cervical scrapes were evaluated using the Hybrid Capture System. The study population had an average age of 30 years and were HIV-negative. Women from the general population were largely of Spanish nationality, and 61% reported lifetime monogamy. The majority of the prostitutes (76%) were immigrants, primarily from South America. Sex workers were twice as likely to be infected with KSHV than women in the general population (16% vs. 8%, prevalence odds ratio [OR] = 2.2). KSHV was more prevalent among HPV DNA-positive women (OR = 2.5) and among women with an early age at first sexual intercourse (OR = 2.7, p < 0.05). KSHV DNA was detected by PCR in 3% of the oral cavity samples, in 2% of the cervical samples of the prostitutes and in 1% of the cervical samples of women in the general population. All PBMC samples were negative. These results suggest that in low-risk countries for KSHV, oral shedding and heterosexual contacts are potential pathways for KSHV transmission.

Adult↗
PubMed2002

Evidence for Chlamydia trachomatis as a human papillomavirus cofactor in the etiology of invasive cervical cancer in Brazil and the Philippines.

Chlamydia trachomatis infection was examined as a cause of invasive cervical cancer (ICC) among women with human papillomavirus (HPV) infection. In total, 499 women with incident ICC (ICC patients) and 539 control patients from São Paulo, Brazil, and Manila, the Philippines, were included. C. trachomatis antibodies were detected by microimmunofluorescence assay. Presence of HPV DNA in cervical specimens was determined by a polymerase chain reaction-based assay. C. trachomatis seropositivity was associated with sexual behavior but not with HPV infection. C. trachomatis increased the risk of squamous cervical cancer among HPV-positive women (odds ratio, 2.1; 95% confidence interval, 1.1-4.0). Results were similar in both countries. There was a suggestion of increasing squamous cancer risk with increasing C. trachomatis antibody titers. This large study examined C. trachomatis and cervical cancer, taking into account the central role of HPV infection. C. trachomatis infection was found to be a possible cofactor of HPV in the etiology of squamous cervical cancer, and its effect may be mediated by chronic inflammation.

Adult↗
PubMed2002

Aflatoxin, hepatitis and worldwide liver cancer risks.

Aflatoxins are among the most potent mutagenic and carcinogenic substances known. Differential potency of aflatoxin among species can be partially attributed to differences in metabolism; however, current information on competing aspects of metabolic activation and detoxification of aflatoxin in various species does not identify an adequate animal model for humans. Risk of liver cancer is influenced by a number of factors, most notably carriage of hepatitis B virus as determined by the presence in serum of the hepatitis B surface antigen (HBsAg+ or HBsAg-). About 50 to 100% of liver cancer cases are estimated to be associated with persistent infection of hepatitis B (or C) virus. The potency of aflatoxin in HBsAg+ individuals is substantially higher (about a factor of 30) than the potency in HBsAg- individuals. Thus, reduction of the intake of aflatoxins in populations with a high prevalence of HBsAg+ individuals will have greater impact on reducing liver cancer rates than reductions in populations with a low prevalence of HbsAg+ individuals. The present analysis suggests that vaccination against hepatitis B (or protection against hepatits C), which reduces prevalence of carriers, would reduce the potency of the aflatoxins in vaccinated populations and reduce liver cancer risk.

Aflatoxins↗
PubMed2002

Human papillomavirus in cervical cancer.

Epidemiologic studies supported by molecular technology have provided sufficient evidence of the causal role of some human papillomavirus (HPV) infections in the development of cervical cancer. The finding is consistent universally, and HPV has been proposed as the first identified necessary cause of cervical cancer. Such recognition translates into the concept that cervical cancer does not develop without persistent presence of HPV DNA. In the developed parts of the world, cytologic screening programs could benefit from the addition of HPV testing to their protocols. Controlled studies and one randomized trial have shown that HPV testing is helpful in solving the ambiguous cases generated by cytology reading. In populations where cytology programs are not functional or efficient, HPV testing is being evaluated as an alternative means of primary screening. Prevention of exposure to high-risk HPV types, either by prophylactic vaccination or by combined prophylactic and therapeutic immunologic intervention, may prove to be the most efficient and logistically feasible option for the prevention of cervical cancer in developing populations.

Age Distribution↗
PubMed2002

The viral etiology of cervical cancer.

Epidemiological studies supported by molecular technology have provided sufficient evidence on the causal role of some Human Papillomavirus (HPV) infections in the development of cervical cancer. This association has been evaluated under all proposed sets of causality criteria and endorsed by the scientific community and major review institutes. HPV has been proposed as the first-ever identified, necessary cause of a human cancer. In practical terms, the concept of a necessary cause implies that cervical cancer does not and will not develop in the absence of the persistent presence of HPV-deoxyribonucleic acid (DNA). This important advancement has two practical implications in prevention. Firstly, screening programs can be enhanced if HPV testing is judiciously incorporated into solving the fraction of ambiguous cytology readings. In some populations HPV screening as a primary test may prove to be the strategy of choice. Secondly, like in the hepatitis B disease model, intense efforts are currently being put into the development and testing of vaccines that may prevent the relevant HPV infections, and presumably, cervical cancer. At this stage of development, regulatory agencies are requested to evaluate the scientific evidence and weigh its implications in relation to costs, public health investments and policy. This is a subjective evaluation that could be guided by a careful description of the most relevant studies and findings.

Adolescent↗
PubMed2002

Environmental co-factors in HPV carcinogenesis.

Epidemiological studies have shown that only a small fraction of women infected with oncogenic HPV types will eventually progress to high-grade intraepithelial lesions (HSIL) and cervical cancer (CC). Because infection by oncogenic HPVs is a necessary but not a sufficient cause of CC, it has been assumed that other factors, acting in conjunction with HPV, influence the risk of transition from cervical HPV infection to cervical malignancy. This paper reviews the epidemiological evidence for the role of environmental co-factors in HPV carcinogenesis as assessed from selected studies that report associations within a well-defined HPV-DNA positive group. Co-factors assessed include parity, use of oral contraceptives, tobacco smoking, infection with other sexually transmitted diseases, and dietary and nutritional factors. Based on the evidence provided by the largest epidemiological studies that using sensitive detection methods allowed for the effects of HPV, it can be concluded that, among HPV positive women, high parity, long-term OC use, smoking, and co-infection with other sexually transmitted agents are the most consistently identified environmental co-factors likely to influence the risk of progression from cervical HPV infection to HSIL and invasive CC. There is limited evidence for a role of dietary factors in HPV carcinogenesis. On-going epidemiological studies will shed more light into the role of these and other co-factors, but if confirmed, these conclusions may imply that multiparous women, women who are smokers, and women on long-term OC use, might need a closer cytological and HPV surveillance than women in the general population.

Contraceptives, Oral↗
PubMed2002

Risk factors of invasive cervical cancer in Mali.

BACKGROUND: Cervical cancer is the most common cancer in women in Mali and the second commonest cause of cancer mortality. METHODS: As part of an international effort to evaluate the role of human papillomavirus (HPV) in the aetiology of cervical cancer, we conducted a hospital-based case-control study in three medical centres in Bamako during 1994-1995. A total of 82 cases (invasive cervical cancer patients) and 97 controls matched to the cases for age were included. Information on risk factors was collected through personal interview. Serum antibodies to HPV 16, 18 and 31 virus like particles (VLP) were detected using ELISA assays. Polymerase chain reaction was used to detect HPV DNA in frozen biopsies of cases. RESULTS: Human papillomavirus 6, 18, 31 VLP were detected in 60.4% of cases and 45.4% of controls (P = 0.03). Overall, HPV DNA was identified in 96.9% of the cervical cancer cases. Risk factors for cervical cancer were parity >10 versus <5 children ([odds ratio] OR = 4.8, 95% CI : 1.5-14.7), never having practised vaginal douching (OR = 17.6, 95% CI : 4.2-74.7), re-using home-made feminine napkins (OR = 45.9, 95% CI : 8.8-238.7) and having a husband with more than two wives (OR = 5.3, 95% CI : 1.3-21.3). CONCLUSIONS: These data provide further evidence on the role of HPV in cervical cancer and show that high parity and poor genital hygiene conditions were the main co-factors for cervical cancer in this population with prevalent HPV infection.

Adult↗
PubMedDate not supplied

[Assessment of HPV detection assays for use in cervical cancer screening programs].

OBJECTIVE: Detection of high-risk human papillomavirus types (HPV) infection is an important tool in the screening of cervical cancer and triage of cytological abnormalities. The different techniques for detection of this cancer need to be contrasted and validated for use in population screening. MATERIAL AND METHODS: Cervical cell samples were collected from 166 women attending a dermatology clinic in Oviedo (Spain). We evaluated the performance of three different assays for VPH detection. The methods utilized were 1) In-house PCR-EIA using LI consensus primers MY09/ MY11, 2) A PCR-reverse line blot hybridization (PCR-LBH) that uses LI consensus PGMY primers. 3) Hybrid Capture 2. All assays were performed blinded. The kappa statistic was used to test for global agreement between assay pairs. RESULTS: HPV DNA was detected in 24,7%, 25,3% and 29,5% of the women, respective to the assay. The overall agreement between the in-house PCR, PCR-LBH and HC2 was (73.5%) with all kappa values between assay pairs exceeding 0.56 (p<0.001). CONCLUSION: The three HPV assays were equally accurate in estimating high-risk HPV prevalence and HPV-related lesions. The method for HPV detection must be decided depending on the goals of the search (screening, follow-up or molecular studies).

DNA Probes, HPV↗