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Biomedical subjects

F X Bosch

Publications and source records attributed to F X Bosch.

157 records · Page 9Linked to original sources
PubMedDate not supplied

Mother to child transmission of hepatitis B virus in the Philippines.

A follow-up study of mother to infant transmission of hepatitis B virus was conducted in the Philippines between 1981 and 1983. The prevalence of HBsAg among 527 mothers was 8.5%. Overall, seven out of 17 (41.2%) infants born to HBsAg carrier mothers became HBsAg positive within the first 12 months of life. The risk of becoming HBsAg positive was about 20 times higher for infants born to HBsAg positive mothers than for infants born to HBsAg negative mothers (OR = 18.9, 95% Ci = 2.0-86.6). The risk was even higher if the mother was a carrier of both HBsAg und HBeAg (OR = 91.0, 95% Ci = 49.2-164.8). However, the risk of transmission was very low if the mother was an HBsAg carrier and anti-HBe positive. It was estimated that mother to infant transmission accounts for about one third of HBsAg positivity at one year of age. The implications of these findings in the planning of vaccination campaigns to prevent HBV infections are discussed.

Adolescent↗
PubMedDate not supplied

[Cancer incidence estimation in Spain: period 1993-1996].

OBJECTIVE: To estimate the number of incident cases of cancer in Spain between 1993 and 1996. METHODS: We used data on the incidence of cancer from nine Spanish population-based cancer registries published in the monograph Cancer incidence in Five Continents, vols. VI and VII (period 1983-92). The National Institute of Statistics provided mortality data (period 1983-96). Generalized linear mixed models were used to estimate the number of incident cases. The incidence/mortality ratio was modeled. To account for heterogeneity, the providence of residence was considered as a random effect. Other factors analyzed were sex, age and period. Model parameters were estimated using a Bayesian approach with BUGS software. Estimates were valdated by comparing the observed number of cases with those predicted by the model in the regions with cancer registry data. RESULTS: The average number of incident cases per annum for all cancer sites except non-melanoma skin cancer was 78,440 for men and 55,480 for women. The most frequent neoplasm in men was lung with 15,480 cases followed by bladder with 9,445 cases and colorectal with 8,876 cases. In women the most frequent cancer was breast with 13,490 cases followed by colorectal with 8,274 cases. These absolute frequencies showed an increasing time trend for all cancers and for the most frequent sites, with the exception of stomach and uterine cervix. Internal validation of the estimates allowed calculation of a relative error smaller than 10%. IMPLICATIONS: This is the first time that the number of incident cases of cancer in Spain has been estimated with methods that account for heterogeneity. These figures show the importance of cancer as a public health problem in our community.

Adult↗
PubMedDate not supplied

Risk factors for HPV DNA detection in middle-aged women.

BACKGROUND AND OBJECTIVES: Strong epidemiologic evidence indicates that human papillomavirus (HPV) is the main etiologic factor of cervical cancer. A few cohort studies suggest that most HPV infections are transient in young women and that persistent HPV infections are more common in older women. Little is known about the determinants of persistent HPV infections. The present study was aimed at increasing our knowledge about these determinants. GOALS: To identify risk factors for genital HPV DNA detection among cytologically normal middle-aged women. STUDY DESIGN: Eight hundred ten women who participated as control subjects in three case-control studies on cervical cancer in Spain, Colombia, and Brazil were included in this study. After an interview, women underwent a gynecologic examination with collection of exfoliated cells for a Papanicolaou smear and HPV DNA detection. Human papilloma virus DNA was detected by polymerase chain reaction (PCR)-based hybridization techniques. RESULTS: The HPV positivity rate was 10.5% in the whole population, but was higher in the areas with high incidence of cervical cancer (17% in Brazil and 13% in Colombia) than in Spain (4.9%), which is a low-risk area for cervical cancer. Age was related to the prevalence of HPV DNA in Brazil, but not in Spain and Colombia. In univariate analyses in all three countries, the prevalence of HPV DNA was positively associated with the number of lifetime sexual partners and inversely associated with the levels of family income and with age at first sexual intercourse. There was four times increase in the odds ratio (OR) of HPV infection in women who had six or more lifetime sexual partners compared with those with one or less. The use of any kind of contraceptive tended to decrease the OR for HPV detection. Their ORs ranged from 0.44 (barrier methods) to 0.48 (oral contraceptives). In Spain and Colombia, antibodies against Chlamydia trachomatis were positively associated with the prevalence of HPV DNA. In a final multivariate model, the positive associations with lifetime number of sexual partners, socioeconomic status, and C. trachomatis persisted. CONCLUSIONS: These results support the sexual transmission of HPV and suggest that socioeconomic status and antibodies to C. trachomatis are independent predictors of HPV detection in middle-aged cytologically normal women.

Adult↗
PubMedDate not supplied

Epidemiology of liver cancer in Europe.

Liver cancer (LC) ranks fifth in frequency in the world, with an estimated 437,000 new cases in 1990. The estimates are different when LC frequency is analyzed by sex and geographical areas. In developed areas, the estimates are 53,879 among men and 26,939 among women. In developing areas, the estimates are 262,043 in men and 93, 961 in women. Areas of highest rates include Eastern and South Eastern Asia, Japan, Africa and the Pacific Islands (LC age-adjusted incidence rates [AAIRs] ranging from 17.6 to 34.8). Intermediate rates (LC AAIRs from 4.7 to 8.9 among men) are found in Southern, Eastern and Western Europe, Central America, Western Asia and Northern Africa. Low rates are found among men in Northern Europe, America, Canada, South Central Asia, Australia and New Zealand (LC AAIRs range from 2.7 to 3.2). In Europe, an excess of LC incidence among men compared with women is observed, and the age peak of the male excess is around 60 to 70 years of age. Significant variations in LC incidence among different countries have been described and suggest differences in exposure to risk factors. Chronic infection with the hepatitis B virus (HBV) and hepatitis C virus (HCV) in the etiology of LC is well established. In Europe, 28% of LC cases have been attributed to chronic HBV infection and 21% to HCV infection. Other risk factors such as alcohol consumption, cigarette smoking and oral contraceptives may explain the residual variation within countries. Interactions among these risk factors have been postulated. New laboratory techniques and biological markers such as polymerase chain reaction detection of HBV DNA and HCV RNA, as well as specific mutations related to LC, may help to provide quantitative estimates of the risk related to each these factors.

Adolescent↗
PubMedDate not supplied

Cervical cancer and human papillomavirus: epidemiological evidence and perspectives for prevention.

Cervical cancer is a major public health problem, as it is the second most common cancer in women world-wide after breast cancer. About 80% of the half a million cases estimated to occur annually in the world, occur in developing countries. The epidemiological evidence linking human papillomavirus (HPV) to cervical cancer is reviewed. It is concluded that over 90% of cervical cancers can be attributed to certain HPV types. HPV 16 accounts for the highest proportion (50%) followed by HPV 18 (12%), HPV 45 (8%) and HPV 31 (5%). The association with these HPV types are very strong and consistent with odds ratios over 15 in all case-control studies in high- and low-risk countries for cervical cancer. However, HPV is not a sufficient cause of this malignancy; certain cofactors are necessary for a proportion of HPV persistent infections to eventually progress to cancer. These include host factors such as histocompatibility types and immunological response, hormonal influences and infections with other sexually transmitted agents such as Chlamydia trachomatis. In addition, results from our studies carried out in Spain and Colombia support the hypothesis that male carriers of HPV play an important role in the development of cervical cancer in their wives. The recognition of the central role of HPV in cervical cancer has far-reaching implications for the primary and secondary prevention of this malignancy. Prophylactic and therapeutic HPV vaccines are now under development and HPV typing is being integrated into screening programmes in pilot studies in a few developed countries. In developing countries, well conducted conventional screening programmes remain the best approach for the control of cervical cancer until a safe and efficient HPV vaccine can be used in the general population.

Carcinoma in Situ↗
PubMedDate not supplied

Risk factors for progression of cervical intraepithelial neoplasm grade III to invasive cervical cancer.

Data from four case-control studies on invasive cervical cancer and on cervical intraepithelial neoplasia grade III (CIN III) that were concurrently conducted in Spain and Colombia were used to look for factors that might favor the progression from CIN III to the invasive stage. These studies were compared in two ways; a case-case comparison and an estimation of the ratio of odds ratios with the use of of special logistic regression model that took into account the different design of each study and possible confounding factors. Variables studied were human papillomavirus status, viral load, viral types, sexual behavior, sexually transmitted diseases, reproductive patterns, oral contraceptives, and smoking. Both CIN III and invasive cervical cancer have a very similar profile of risk factors and none of them was different in a consistent way to suggest a role in the progression from CIN III to invasive cervical cancer. Some methodological problems such as cohort-specific differences and some selection biases could be adjusted for with a careful statistical analysis. Other problems derived from the cross-sectional nature of the design are unavoidable and should be considered in the interpretation of the results.

Adult↗
PubMedDate not supplied

Importance of human papillomavirus endemicity in the incidence of cervical cancer: an extension of the hypothesis on sexual behavior.

The risk of cervical cancer for a woman depends largely on the probability of being infected with some specific types of Human Papillomavirus (HPV). In the control groups of four case-control studies in Colombia and Spain we have shown a strong correlation between the number of sexual partners of males and females and HPV DNA prevalence in the genital tract. Our results suggest that the lifetime number of sexual partners in both sexes are surrogates of the probability of HPV infection and, as such, insufficiently explain the geographical variation in the incidence of cervical cancer. It is proposed that the high rates of cervical cancer in Latin America are linked to the largely unknown characteristics of the HPV endemicity in the population and to the absence of widespread screening for cervical neoplasia. Reliable surveys on the HPV prevalences in selected social groups (i.e., young males and prostitutes) as well as in populations in countries at different risk of cervical cancer are required.

Adult↗
PubMedDate not supplied

Human papillomavirus and cervical intraepithelial neoplasia grade III/carcinoma in situ: a case-control study in Spain and Colombia.

A case-control study of 525 cases of cervical intraepithelial neoplasia grade III (CIN III) and 512 controls was conducted in Spain and Colombia between 1985 and 1988 to assess the role of human papillomavirus (HPV) in the etiology of CIN III. HPV DNA in cytological scrapes from the cervix was assessed by Virapap and by polymerase chain reaction (PCR) based on the L1 consensus primers. A subsample of 268 specimens was also tested for HPV DNA using Southern hybridization. In Spain, the PCR-based prevalences of HPV DNA were 70.7% among cases and 4.7% among controls. Odds ratio (OR) and 95% confidence interval (numbers in parentheses) for HPV DNA were 56.9 (24.8-130.6). In Columbia HPV DNA was detected by PCR in 63.2% of the cases and in 10.5% of the controls. The OR was 15.5 (8.2-29.4). The estimated fractions of CIN III attributable to HPV were 72.4% in Spain and 60.3% in Colombia. HPV 16 was the predominant viral type and showed the strongest association with CIN III; in Spain the OR was 295.5 (44.8-1946.4) and in Colombia the OR was 27.1 (10.6-69.5). HPV DNA of unknown type was frequent in HPV-positive cases (18.3% in Spain and 38.0% in Colombia) and controls (66.7% in Spain and 47.4% in Colombia). The comparison of results from Virapap and PCR indicated that PCR is the method of choice for epidemiological studies. These data strongly support the hypothesis of the viral origin of CIN III, the common etiology of CIN III and invasive cervical cancer, and the causal nature of the association between HPV and CIN III.

Adult↗
PubMedDate not supplied

Risk factors for cervical intraepithelial neoplasia grade III/carcinoma in situ in Spain and Colombia.

A case-control study of 525 histologically confirmed cases of cervical intraepithelial neoplasia grade III and 512 controls was done in Spain and Colombia to assess the role of various risk factors taking into account the effect of human papillomavirus (HPV). The presence of HPV DNA, assessed by a polymerase chain reaction-based method, was the strongest risk factor identified. In Spain the adjusted odds ratio (OR) and 95% confidence interval (CI) (numbers in parentheses) were 56.9 (24.8-130.6) and, in Colombia, were 15.5 (8.2-29.4). In addition to HPV, the multivariate analysis revealed independent effects of early age at first intercourse (in Spain ORa, 4.3; 95% CI, 2.0-9.3 for ages < 17 versus 20+ years and in Colombia ORa, 9.0; 95% CI, 2.6-30.9 for ages < 14 versus 20+ years), and antibodies to Chlamydia trachomatis (in Spain ORa, 2.3; 95% CI, 1.1-4.5; and in Colombia ORa, 1.7; 95% CI, 1.1-2.7). High parity showed a significant effect only in Colombia (ORa, 2.0; 95% CI, 1.0-5.0 for > or = 6 versus 1) while number of partners of the woman and specially of her husband showed a strong effect in Spain only (ORa, 6.9; 95% CI, 3.1-15.3 for partners of the husband > or = 21 versus 1-5). Smoking and use of oral contraceptives did not show significant or consistent associations. Among HPV-DNA positive women early age at first intercourse and high parity increased the risk of cervical intraepithelial neoplasia III but the effect was statistically significant only for the former.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Prostitution, HIV, and cervical neoplasia: a survey in Spain and Colombia.

The prevalence of cervical intraepithelial neoplasia (CIN) and the association of CIN with prostitution was examined in Oviedo, a region in Spain with low incidence of cervical cancer, and in Cali, Colombia, where the incidence of cervical cancer is 6-10 times higher. In Oviedo, the study included 758 prostitutes attending a sexually transmitted diseases clinic and 1203 nonprostitutes attending a family-planning clinic. In Cali, 775 prostitutes and 1795 nonprostitutes attending health centers were included. Seropositivity to common sexually transmitted agents was investigated in Spanish prostitutes. No significant difference was found in the prevalence of CIN between Oviedo and Cali in both prostitutes (2.5 versus 1.8%) and nonprostitutes (1.2 versus 1.1%). Prostitutes had a 2-fold increased risk of CIN as compared to nonprostitutes; in Spain, the prevalence odds ratio (POR) was 2.3 and the 95% confidence interval (CI) was 1.1-4.5, and, in Colombia, POR was 1.8 and the 95% CI was 0.9-3.5. Among prostitutes in Oviedo, human immunodeficiency virus (HIV) prevalence was 4.9% and HIV-positive prostitutes showed a high risk of CIN as compared to HIV-negative prostitutes (POR, 12.7; 95% CI, 3.9-40.9); 76% of HIV-positive prostitutes were i.v. drug users and showed an increased seroprevalence of other sexually transmitted diseases. HIV-negative prostitutes did not show any increased risk of CIN (POR, 1.2; 95% CI, 0.5-2.8). These results show that among nonprostitutes the prevalence of CIN was not statistically different between the two cities in Spain and Colombia; prostitutes were at moderate increased risk compared to nonprostitutes in both cities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗