Biomedical subjects

Elena Matos

Publications and source records attributed to Elena Matos.

8 recordsLinked to original sources

PubMed2006

Variations in the age-specific curves of human papillomavirus prevalence in women worldwide.

An inverse relationship between age and human papillomavirus (HPV) prevalence has been reported in many developed countries, but information on this relationship is scarce in many other parts of the world. We carried out a cross-sectional study of sexually active women from the general population of 15 areas in 4 continents. Similar standardised protocols for women's enrolment, cervical specimen collection and PCR-based assays for HPV testing were used. HPV prevalence in different age groups was compared by study area. 18,498 women aged 15-74 years were included. Age-standardised HPV prevalence varied more than 10-fold between populations, as did the shape of age-specific curves. HPV prevalence peaked below age 25 or 35, and declined with age in Italy, the Netherlands, Spain, Argentina, Korea and in Lampang, Thailand and Ho Chi Minh, Vietnam. This was not the case in Songkla, Thailand nor Hanoi, Vietnam, where HPV prevalence was low in all age groups. In Chile, Colombia and Mexico, a second peak of HPV prevalence was detected among older women. In the poorest study areas in Asia (Shanxi, China and Dindigul, India), and in Nigeria, HPV prevalence was high across all age groups. The substantial differences observed in age-specific curves of HPV prevalence between populations may have a variety of explanations. These differences, however, underline that great caution should be used in inferring the natural history of HPV from age-specific prevalences.

Adolescent↗

PubMed2006

Sexual behavior, condom use, and human papillomavirus: pooled analysis of the IARC human papillomavirus prevalence surveys.

Human papillomavirus (HPV) is a sexually transmitted infection but it is unclear whether differences in transmission efficacy exist between individual HPV types. Information on sexual behavior was collected from 11 areas in four continents among population-based, age-stratified random samples of women of ages > or = 15 years. HPV testing was done using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate odds ratios (OR) of being HPV positive and corresponding 95% confidence intervals (95% CI). Variables were analyzed categorically. When more than two groups were compared, floating confidence intervals were estimated by treating ORs as floating absolute risks. A total of 11,337 women (mean age, 41.9 years) were available. We confirmed that lifetime number of sexual partners is associated with HPV positivity (OR for > or = 2 versus 1, 1.86; 95% CI, 1.63-2.11) but the association was not a linear one for HPV18, 31, and 33 (i.e., no clear increase for > or = 3 versus 2 sexual partners). Women who had multiple-type infection and high-risk HPV type infection reported a statistically nonsignificant higher number of sexual partners than women who had single-type and low-risk type infections, respectively. Early age at sexual debut was not significantly related to HPV positivity. Husband's extramarital sexual relationships were associated with an OR of 1.45 (95% CI, 1.24-1.70) for HPV positivity in their wives after adjustment for age and lifetime number of women's sexual partners. We did not observe a significant association with condom use. Our study showed an effect of both women's and their husbands' sexual behavior on HPV positivity. Furthermore, it suggests some differences in the pattern of the association between sexual behavior and different HPV types.

Adolescent↗

PubMed2006

Reproductive factors, oral contraceptive use, and human papillomavirus infection: pooled analysis of the IARC HPV prevalence surveys.

High parity, early age at first full-term pregnancy (FTP), and long-term oral contraceptive (OC) use increase cervical cancer risk, but it is unclear whether these variables are also associated with increased risk of acquisition and persistence of human papillomavirus (HPV) infection, the main cause of cervical cancer. Information on reproductive and menstrual characteristics and OC use were collected from 14 areas worldwide, among population-based, age-stratified random samples of women aged 15 years or older. HPV testing was done using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate the odds ratios (OR) of being HPV-positive according to reproductive and menstrual factors and corresponding 95% confidence intervals (CI). When more than two groups were compared, floating CIs (FCI) were estimated. A total of 15,145 women (mean age, 40.9 years) were analyzed. Women with >or=5 FTPs (OR, 0.90; 95% FCI, 0.76-1.06) showed a similar risk of being HPV-positive compared with women with only one FTP (OR, 1.00; 95% FCI, 0.86-1.16). However, nulliparous women showed an OR of 1.40 (95% CI, 1.16-1.69) compared with parous women. Early age at first FTP was not significantly related to HPV positivity. HPV positivity was similar for women who reported >or=10 years of use of OCs (OR, 1.16; 95% FCI, 0.85-1.58) and never users of OCs (OR, 1.00; 95% FCI, 0.90-1.12). Our study suggests, therefore, that high parity, early age at first FTP, and long-term OC use are not associated with HPV prevalence, but rather these factors might be involved in the transition from HPV infection to neoplastic cervical lesions.

Adolescent↗

PubMed2004

Smoking behavior and its determinants among women in Concordia, Argentina.

This study assessed smoking, sexual, and reproductive behaviors as determinants of smoking behavior in women from Concordia, Province of Entre Ríos, Argentina, a population with a low incidence of lung cancer and a high incidence of cervical cancer. Interviewers administered structured, close-ended questionnaires to 1,028 women, aged at least 15 years, living in a random sample of households. We calculated the prevalence of smoking-related variables by age group and used a multivariate logistic regression model to identify various behavioral determinants of smoking. Overall, 36% of the women reported having ever smoked, and 23% were current smokers. At least 50% of the women who ever smoked in each age group smoked less than 10 cigarettes per day. The main determinants of ever having smoked were single marital status (OR=1.64, 95% CI=1.01-2.66) and reporting two or more lifetime sexual partners (two or three: OR=2.25, 95% CI=1.63-3.07; four: OR=3.54, 95% CI=2.10-5.08). No association with socioeconomic level, reproductive characteristics, or variables related to health behavior was observed. We conclude that the prevalence of smoking was high, particularly among women aged 35-54 years, and was strongly associated with sexual behavior. Although women seem to be starting to smoke at younger ages compared with women in the past, the younger cohorts do not seem to be taking up the practice to the same extent as the older cohorts. Antismoking interventions and appropriate control measures are still necessary.

Adult↗

PubMed2003

Prevalence of human papillomavirus infection among women in Concordia, Argentina: a population-based study.

BACKGROUND: Preparing for HPV vaccine programs, studies are needed of HPV infection in different populations. GOAL: The goal was to evaluate HPV prevalence and determinants in Concordia, Argentina. STUDY DESIGN: A stratified random sample of 1786 households was obtained. Consenting women aged > or =15 years were interviewed and underwent examination, including colposcopy. Cells were collected for a Papanicolaou smear and HPV DNA testing with GP5+/6+ primer-mediated PCR-EIA. RESULTS: PCR was performed on specimens from 987 women. Prevalence among women reporting no previous sexual activity was 3%, and among sexually active women it was 17.7%, peaking at <25 years of age and decreasing to a minimum at > or =65 years of age. However, low-risk types had similar prevalence (approximately 5%) in all age groups. HPV16 (4.0%), HPV35 (2.6%), and other high-risk types were the most common. Almost half of infections were multiple. Younger women initiated sexual activity earlier and had more partners. The main determinants of HPV detection were lifetime number of sex partners and vaginal discharge. CONCLUSION: A clear pattern of decreasing prevalence of HPV with age was observed. This could be explained by development of immunity against specific types over time or related to a cohort effect associated with a recent spread of HPV in this population after recent changes in sexual behavior.

Adolescent↗

PubMed2002

Review on meat consumption and cancer in South America.

Consumption of red meat and its heterocyclic amines (HCA) content has been associated with an increased risk for colorectal cancer and, with less consistency, with stomach, oesophagus, pancreas, breast, prostate and kidney cancers. Uruguay and Argentina's rates for breast and colon cancer are among the highest in the world. The main type of meat consumed in these countries is beef, of which consumption rank first and second, respectively in the world, with about 60 kg per year per capita. Beef is cut in different ways following the customs of different countries and regions. The predominant consumption of different cuts and ways of cooking, are described for different regions within Argentina as well as frequencies of consumption of different kinds of meats. These differences reflect not only habits and customs but also socioeconomic variations among regions.A review of epidemiological studies performed in South American countries related to meat consumption, ways of cooking, HCA, and different cancers is presented. It is concluded that comparisons among studies generated in countries or regions with different meat types, beef cuts consumption usage and cooking methods must be very careful. Hence, future research for the verification of the observed associations between HCA and cancer, should be conducted through in-depth, chemically validated questionnaires based on local data.

Amines↗

PubMed2002

Circulating 92-kilodalton matrix metalloproteinase (MMP-9) activity is enhanced in the euglobulin plasma fraction of head and neck squamous cell carcinoma.

BACKGROUND: Cancer lethality is usually the result of local invasion and metastasis of neoplastic cells from the primary tumor. Because of their ability to degrade extracellular matrix components (EMC), matrix metalloproteinases (MMPs) have been implicated in the breakdown of basement membranes and underlying stroma, thereby facilitating tumor growth and invasion. METHODS: The authors quantitated, by gelatin zymography and densitometric analysis, MMP activity in the euglobulin plasma fraction of 50 healthy controls and 91 head and neck squamous cell carcinoma (HNSCC) patients (51 from the larynx and 40 from the oropharynx). RESULTS: The median value for 92-kilodalton (kD) MMP (MMP-9) activity was increased significantly in laryngeal (Md 2.1 arbitrary units (AU)/mL plasma; range, 0.2-6.4) and oropharyngeal patients (Md 2.08 AU/mL; range, 0.0-5.0) with respect to the controls (Md 0.48 AU/mL; range, 0.0-1.8). Both groups of cancer patients showed a similar behavior. Multivariate analysis indicated that circulating 92-kD MMP activity was not predicted by the clinical-pathologic parameters such as tumor stage, histologic grade, and metastatic lymph nodes. There was no association between high levels of MMP-9 activity and either cigarette smoking or alcohol consumption, major risk factors for developing HNSCC. CONCLUSIONS: The authors found a significant increase of MMP-9 plasma activity both in laryngeal and oropharyngeal squamous cell carcinoma patients as compared with healthy controls. Further studies are necessary to establish its usefulness in the clinical management of these patients.

Adult↗

PubMed2002

CD44 expression in human gliomas.

BACKGROUND AND OBJECTIVES: Glioma invasiveness involves the attachment of tumor cells to the brain extracellular matrix, rich in hyaluronic acid (HA). CD44, the principal receptor for HA is found as a standard molecule (CD44s) or as variants (CD44v). We undertook a retrospective study to evaluate the expression pattern of CD44s, the isoforms CD44v3, v4/5 and v6 and to correlate their expression with clinical-anatomopathological parameters and survival rate. METHODS: The expression of these molecules was evaluated immunohistochemically in 84 gliomas. RESULTS: No expression of CD44v was detected in any tumors. CD44s staining of tumor cells was found in 70 of 84 (83.3%) of the gliomas. In 23 of 39 (59.0%) of the GBM more than the 70% of the cells were stained, while only 2 of 21 (9.5%) of LGA showed high expression. The association between CD44 and histological grade remained when the prognostic variables were considered in a multivariate analysis. Higher expression of CD44 was associated with worse overall survival rate; however, the Cox analysis indicated that survival was not associated with CD44. CONCLUSIONS: Our results suggest that overexpression of CD44s could be relevant in determining the highly invasive behaviour of gliomas, though it does not behave as an independent prognostic factor for survival.

Adolescent↗