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Biomedical subjects

E Lazcano-Ponce

Publications and source records attributed to E Lazcano-Ponce.

At least 19 recordsLinked to original sources
PubMed2006

Frequency of antibodies against E4 and E7 from human papillomavirus type 16 in Mexican soldiers.

The high prevalence of HPV in men's genitalia and the low frequency of virus-associated lesions gave rise to questions on the influence of infection-site on the HPV antibody profile. In a cross-sectional study, HPV infection in penis and urethra, and serum antibodies against HPV-16 E4 and E7 proteins were evaluated in 288 Mexican soldiers. The results showed that HPV prevalence was 31% (51% in penis, 11% in urethra and 38% in both sites), while 47% were multiple infections. Overall, seroprevalence was 13% for anti-E4 antibodies and 6% for anti-E7. However, the highest prevalence of anti-E4 antibodies was observed in men with HPV infection in urethra (30%), while for E7 antibodies, the highest prevalence (10%) was found in men who tested positive for HPV in penis. The prevalence of IgG and IgA anti-E4 was related to HPV-16 urethral infection, while detection of HPV-16 in penis was related to IgG anti-E7 prevalence. In conclusion, the high-risk sexual behavior observed in this population might be responsible for high HPV prevalence and multiple infections. However, the seroprevalence of E4 and E7 was similar to that observed in healthy Mexican women. These results suggest that the humoral immune response against HPV infection in men differs, depending on the site of infection.

Adolescent↗
PubMed2006

Human papillomavirus in men: comparison of different genital sites.

OBJECTIVE: To elucidate which anatomical sites need to be sampled to detect human papillomavirus (HPV) infection in the lower male genital tract. METHOD: In an HPV survey of Mexican soldiers (median age 24 years; range 16-50 years), a cell sample from 2 cm deep into the distal urethra (group 1; n = 168 men), or 0.5 cm deep into the meatus urethralis (group 2; n = 414 men) was collected, along with a sample from the external genitalia. The different samples were tested for 27 HPV types using a polymerase chain reaction based strip assay. RESULTS: HPV DNA was detected more frequently in external genitalia samples (46.4%) than in the urethra (20.8%) or meatus samples (12.1%). Lack of samples from the urethra or meatus would have led to 5.1% and 1.5% false HPV negative results, respectively. The most frequently detected high risk HPV types (HPV 59, 52, 51, and 16) were similar in different sites, whereas low risk types were found rarely in urethra samples. CONCLUSIONS: The addition of cell samples from the meatus to those from external genitalia contributed negligibly to the evaluation of the prevalence of HPV in men. HPV detection was slightly improved by the addition of urethra samples, but the gain may not justify the discomfort of the procedure in large epidemiological studies.

Adolescent↗
PubMed2005

Early alcohol or tobacco onset and transition to other drug use among students in the state of Morelos, Mexico.

UNLABELLED: In this study, we explored if patterns in the transition from alcohol/tobacco in the Mexican State of Morelos, Mexico are similar to those observed in other countries. METHODS: The data were from a representative sample of youth age 11-21 years (n = 13,105), who participated in a paper-and-pencil survey in middle schools, high schools, and colleges in the State of Morelos, Mexico. Drug use was assessed via the standardized instrument mostly used in Mexican student surveys. Cox's models for discrete time-survival analyses, stratified by school and age group were used to estimate the risk of drug use in relation to age of alcohol and tobacco use initiation by gender, while accommodating the complex survey design. RESULTS: About 5% of the students were estimated to have used drugs in their life. Male early users of alcohol or tobacco were more likely to use other drugs, compared to students who did not have an early alcohol or tobacco onset. COMMENT: Further studies on social mechanisms might help to account for observed similarities in patterns of drug involvement in different countries, even in the context of important differences in rates of drug use.

Adolescent↗
PubMed2005

Gender, body mass index and socio-demographic variables associated with knowledge about type 2 diabetes mellitus among 13,293 Mexican students.

The main aim of this study was to evaluate correlates of the knowledge Mexican young people have about type 2 diabetes mellitus (DM) risk and prevention. We developed a cross-sectional study in public schools in Morelos, in central Mexico during 1998-1999 in 13,293 students (11-24 years). We determined body mass index (BMI) with anthropometric measurements (height and weight). Using questionnaire data, we constructed a DM knowledge-based scale. Statistical analysis was done using an ordinal, logistic regression model. Only 1.6% of the students (95%CI = 1.4-1.8) had high DM knowledge levels; 85.6% (95%CI = 84.9-86.1) had low levels. The factors with the strongest associations with high levels of knowledge about type 2 DM among the Mexican students in this study were: being in high school or at university (vs. junior high), urban residence, higher socio-economic level, and BMI indicating overweight or obesity. Other socio-demographic factors correlated with high levels of knowledge about the disease, but with slightly weaker associations, included female gender, higher age, higher academic achievement (grades) and higher education level of the student's mother. While young men who were overweight or obese were 2.6 and 3.4 times more likely to have high levels of knowledge about DM (95%CI = 1.9-3.6 and 2.1-5.5, respectively), young women who were overweight or obese were only 1.4 and 1.1 times more likely to have high knowledge about DM (95%CI = 1.0-1.9 and 0.6-1.8, respectively). Mexican young people have limited knowledge about DM, although this chronic disease is increasingly common in Mexico as in many other countries.

Adolescent↗
PubMed2001

Epidemiology of HPV infection among Mexican women with normal cervical cytology.

Cervical cancer is caused by human papillomavirus (HPV) and is the most common cancer among Mexican women, but no population-based studies have reported the prevalence and determinants of HPV infection in Mexico. A population-based study was carried out between 1996 and 1999, based on an age-stratified random sample of 1,340 women with normal cytologic diagnoses from 33 municipalities of Morelos State, Mexico. The prevalence of cervical HPV DNA was determined by reverse line blot strip assay to detect 17 cancer-associated and 10 non-cancer-associated HPV types. Two peaks of HPV DNA prevalence were observed. A first peak of 16.7% was observed in the age group under 25 years. HPV DNA prevalence declined to 3.7% in the age group 35-44 years, then increased progressively to 23% among women 65 years and older. Cancer-associated HPV types were the most common in all age groups; non-cancer-associated HPV types were rare in the young and became more common linearly with age. Twenty-four types of HPV were detected; HPV 16, HPV 53, HPV 31 and HPV 18 were the most common, but none was present in more than 1.7% of subjects. The main determinant of infection with both cancer-associated and non-cancer-associated HPV types was the number of sexual partners in all age groups. Less-educated women were at an increased risk of infection with cancer-associated but not with non-cancer-associated HPV types; low socioeconomic status was associated with detection of non-cancer-associated HPV types. Among young women an increasing number of pregnancies was associated with lower HPV detection and among older women low socioeconomic status was related to increased HPV detection, particularly for the age group 35-54 years. Among women with cancer-associated HPV types, there was a higher intensity of polymerase chain reaction signal in younger than in older age groups (p < 0.001). We present additional evidence for the sexually transmitted nature of HPV infection, regardless of age group and HPV type. We confirm previous findings of a second peak of high-risk HPV infections in postmenopausal women, in this case with a clear predominance of cancer-associated HPV types. In populations with this pattern, which can be related to reactivation of latent HPV infections or high previous exposure in older women, screening with HPV testing can have a reduced specificity among older women if proper cut-off points for HPV positivity are not used. Longitudinal studies of immune responses to HPV infection in different age groups are warranted.

Adult↗
PubMed2001

Prognostic factors related to cervical cancer survival in Mexican women.

OBJECTIVE: To identify prognostic survival factors among Mexican women with cervical cancer. METHODS: A total of 378 women with cervical cancer admitted from 1984 to 1996 to our referral hospital were evaluated, using survival analysis (Kaplan-Meier and Cox proportional hazards method). We designed a symptom index which included asymptomatic conditions, severity of symptoms and comorbidity. RESULTS: Overall 5-year survival was 66.6%. The shortest survival time was for FIGO stage IV (21.5%, P<0.001) and adenosquamous histologic type (53.1%, P=0.15). The main prognostic factors were primary symptoms (RR, 2.6; 95% CI, 1.02-6.66); systemic symptoms (RR, 3.3; 95% CI, 1.23-9.01); FIGO stage IV (RR, 5.5; 95% CI, 2.36-12.96); and oncogenic symptoms (prognostic comorbidity present) (RR, 2.3; 95% CI, 1.08-4.89). CONCLUSIONS: Our findings show that clinical stage and several types of symptoms influence CC survival. This present strategy to assess morphological and clinical characteristics may be a more accurate indicator of survival rate and potentially an efficient indicator of new therapeutic alternatives.

Adenocarcinoma↗
PubMed2001

High prevalence of antibodies to herpes simplex virus type 2 among middle-aged women in Mexico City, Mexico: a population-based study.

BACKGROUND: Herpes simplex virus type 2 (HSV-2) is among the most prevalent sexually transmitted diseases worldwide. In Mexico there is a lack of population-based HSV-2 surveys. GOALS: To determine population-based HSV-2 seroprevalence and risk factors among women in Mexico City. STUDY DESIGN: A random sample of 730 women was identified among the residents of Mexico City. Women ages 25 to 85 years were selected from 3,694 households. Western blot serology testing was conducted on serum samples to determine HSV-2 type-specific serostatus. A structured questionnaire was administered, and multivariate analyses were performed to identify risk factors for HSV-2 seropositivity, which were stratified into two age categories: younger than 50 years of age and 50 years of age or older. RESULTS: The HSV-2 seroprevalence among female participants was 29.8%, with a significant trend of increasing HSV-2 prevalence for each higher level of age (P < 0.001). Female participants had a median age of 46 years and were predominantly monogamous (82.6%). The overall population-based seroprevalence estimated in Mexico City among women was 35.8%. The independent risk factors for HSV-2 seropositivity included a history of two or more sexual partners (odds ratio [OR], 2.2; 95% CI, 1.4-3.4), two or more sexual partners before first pregnancy (OR, 2.3; 95% CI, 1.4-3.7), cohabitation with partner (OR, 2.5; 95% CI, 1.3-4.7), and current vaginal douching (OR, 1.7; 95% CI, 1.2-2.6). CONCLUSIONS: Population-based HSV-2 seroprevalence is endemically high among middle-age women in Mexico City, and clearly is correlated with higher-risk sexual behavior. This elevated HSV-2 seroprevalence may reflect unrecognized HSV-2 transmission throughout life.

Adolescent↗
PubMed2001

High prevalence of human papillomavirus infection in Mexican males: comparative study of penile-urethral swabs and urine samples.

BACKGROUND: Although extensive information has been gathered about the prevalence and determinants of human papillomavirus infection among women, little is known about the prevalence and natural history of this infection among males. GOAL: To investigate the potential usefulness of urine specimens to assess the presence of genital human papillomavirus DNA infection. STUDY DESIGN: The authors conducted a study of 120 healthy men from Cuernavaca, Mexico. A urine specimen and urethral and coronal sulcus swab samples were collected and tested for human papillomavirus using the GP5+/6+ polymerase chain reaction enzyme immunoassay method. RESULTS: In 95% of the urethral-coronal sulcus samples, the beta-globin gene was detectable, indicating adequacy of the specimen for DNA amplification; however, only 14% of the urine specimens had detectable beta-globin. Removal of inhibitors by DNA purification in a sample of subjects produced beta-globin amplification, but no increase in human papillomavirus DNA positivity was detected. Human papillomavirus DNA was not detectable in penile-urethral swab samples in any of the subjects who reported not having engaged in sexual activity but was present in 43% of men who reported sexual activity, a strong indication of the sexual transmission of human papillomavirus. CONCLUSIONS: Human papillomavirus is a common sexually transmitted infection among Mexican males, and urine sample specimens cannot adequately detect the presence of this infection in males.

Adolescent↗
PubMed2000

Breast cancer, lactation history, and serum organochlorines.

The authors analyzed the relation between lactation history, organochlorine serum levels-in particular, 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE)-and the risk of breast cancer within a subsampe from a larger breast cancer case-control study conducted among women living in Mexico City, Mexico, between 1990 and 1995. From the original study, they selected a random sample of 260 subjects (1:1 case/control ratio). Analysis was restricted to 120 cases and 126 controls who had given birth to at least one child and had complete information on all key variables. Serum DDE levels were higher among cases (mean = 3.84 microg/g lipids, standard deviation = 5.98) than among controls (mean = 2.51 microg/g lipids, standard deviation = 1.97). After adjustment for age, age at menarche, duration of lactation, Quetelet index, and serum DDT levels, serum DDE levels were positively related to the risk of breast cancer (adjusted odds ratio (OR)Q1-Q2 = 1.24, 95% confidence interval (CI): 0.50, 3.06; ORQ1-Q3 = 2.31, 95% CI: 0.92, 5.86; ORQ1-Q4 = 3.81, 95% CI: 1.14, 12.80; test of trend, p = 0.02). The increased risk associated with higher serum DDE levels was more apparent among postmenopausal women (ORQ1-Q4 = 5.26, 95% CI: 0.80, 34.30; test of trend p = 0.03). A longer period of lactation was associated with a slightly decreased risk of breast cancer independently of serum DDE levels (OR = 0.91, 95% CI: 0.85, 0.99 change in risk per 10 months of lactation). Serum DDT level was not related to the risk of breast cancer. The data suggest that high levels of exposure to DDE may increase women's risk of breast cancer, particularly among postmenopausal women.

Adult↗
PubMed2000

Breast cancer in Mexican women: an epidemiological study with cervical cancer control.

INTRODUCTION: In Mexico, breast cancer (BC) is one of the main causes of cancer deaths in women, with increasing incidence and mortality in recent years. Therefore, the aim of the study is identify possible risk factors related to BC. METHODS: An epidemiological study of hospital cases of BC and controls with cervical uterine cancer (CUCA) was carried out at eight third level concentration hospitals in Mexico City. The total of 353 incident cases of BC and 630 controls with CUCA were identified among women younger than 75 years who had been residents of the metropolitan area of Mexico City for at least one year. Diagnosis was confirmed histologically in both groups. Variables were analyzed according to biological and statistical plausibility criteria. Univariate, bivariate and multivariate analyses were carried out. Cases and controls were stratified according to the menopausal hormonal status (pre and post menopause). RESULTS: The factors associated with BC were: higher socioeconomic level (OR= 2.77; 95%CI = 1.77 - 4.35); early menarche (OR= 1.32; 95%CI= 0.88 - 2.00); old age at first pregnancy (>31 years: OR= 5.49; 95%CI= 2.16 - 13.98) and a family history of BC (OR= 4.76; 95% CI= 2.10 - 10.79). In contrast, an increase in the duration of the breastfeeding period was a protective factor (>25 months: OR= 0.38; 95%CI= 0.20 - 0.70). CONCLUSIONS: This study contributes to the identification of risk factors for BC described in the international literature, in the population of Mexican women. Breastfeeding appears to play an important role in protecting women from BC. Because of changes in women's lifestyles, lactation is decreasing in Mexico, and young women tend not to breastfeed or to shorten the duration of lactation.

Adult↗
PubMed1999

[Reproductive risk factors associated with breast cancer in Colombian women].

INTRODUCTION: As of 1992, breast cancer has been the second cause of death in Columbian women, with a rising trend in mortality due to this type of neoplasm (average annual rate 4.5*/100.000 inhabitants). Information about potential risk factors for breast cancer in Latin American countries is scarce. The objectives of the project were to test the breastfeeding protection against breast cancer and to establish the reproductive factors associated with breast cancer in Columbia. METHODS: A hospital case-control study was carried out from July 1995 to March 1996 in Bogotá, Columbia, using paring by age groups. The study population consisted of 171 histopathologically confirmed cases and 171 controls. Reproductive history and sociodemographic data were collected through a questionnaire, and logistic regression models were used for statistical analysis of the data. RESULTS: The following associated factors were found as principal results: nuli-parousness as compared with women with over 3 children (OR=3.35 CI 1.40-8.0), age at first birth (OR=1.83 CI 0.70- 4.80), breast cancer history, breastfeeding the first child (OR=0.09 CI 0.01-0.64 for 1-11 months) and with a highly significant trend for accumulated breastfeeding above 24 months (p=0.001). CONCLUSIONS: This study indicates the importance of focusing on the promotion of prolonged breastfeeding by women identified as being at higher risk, and confirms that socio-economic level can determine life styles and reproductive events among women (such as breastfeeding time); this could explain the increase in breast cancer mortality in Latin American countries, similar to that in developed countries in terms of fertility and risk factors for breast cancer. The epidemiological information produced by this study will be useful for planning and carrying out early diagnosis and treatment of breast cancer in women identified as being at high risk of this disease.

Adult↗
PubMedDate not supplied

Acceptability of a human papillomavirus (HPV) trial vaccine among mothers of adolescents in Cuernavaca, Mexico.

BACKGROUND: A scenario that must be considered when testing prophylactic human papillomavirus (HPV) vaccines in teenagers is the parents' acceptability of their daughters' participation in the study. METHODS: A survey was carried out in a random sample of 880 women between the ages of 15 and 49 years in the metropolitan area of Cuernavaca, Mexico. These women were interviewed to obtain information concerning their knowledge of risk factors for cervical cancer and their perception of the usefulness of vaccines. Afterward, they were provided with information on the main risk factors for cervical cancer and the future availability of a human papillomavirus (HPV) vaccine to prevent cervical cancer. Finally, we explored, with parents, the possible acceptability of an HPV vaccine for their teenaged daughters. The degree of acceptability and its association with a series of sociodemographic and reproductive factors were assessed. RESULTS: The respondents had little knowledge regarding the etiology of cervical cancer. Only 1.9% said that the principal risk factor was infection with HPV; however, 84.2% were aware of the usefulness of vaccines and 83.6% of the women indicated that they would allow their daughters to participate in a trial to evaluate the effectiveness of an HPV vaccine that helps prevent cervical cancer. The main factor associated with the acceptance of a possible vaccine against HPV was the knowledge of the usefulness of vaccines [odds ratio (OR) = 6.5, 95% confidence interval (CI) 5.2-8.2]. Likewise, a history of two or more sexual partners (OR = 2.2, 95% CI 1.3-3.6) increased acceptability. Acceptance was not associated with the number of live births (never vs. ever OR = 0.9, 95% CI 0.3-2.1). There were 525 women with children over the age of 10 years (59.6%); prevalence of acceptability among these women was 80.1%, not statistically different from the remainder of the sample (p >0.05). CONCLUSIONS: Acceptance of a potential HPV vaccine was high in this sample of Mexican women. Initiation of HPV vaccine clinical trials and immunization campaigns that target school children and/or teenagers who are not sexually active should include educational programs aimed at mothers of these individuals. Knowledge of the benefits of a preventive vaccine as well as the etiology and risk factors of cervical cancer should be emphasized.

Adolescent↗
PubMedDate not supplied

Dietary factors and endometrial cancer risk. Results of a case-control study in Mexico.

Daily diet factors that could potentially be related to endometrial cancer (EC) in Mexico are still unknown. This study aims to evaluate the association between EC and Mexican dietary factors. A case-control study in Mexico City was conducted during 1995-1997 in a social security hospital, using 85 incident cases of EC and 629 controls. A validated questionnaire with 116 items about the frequency and type of food intake was used. The analysis of nutrients was performed using the residual method, adjusting by predictor variables through logistic regression methods. In addition, partitional models estimated total caloric intake for other sources. We found no association between EC risk and consumption of animal or vegetable proteins, saturated, monounsaturated, or polyunsaturated fat, although high intake of nutrients such as lactose (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.21-1.01, P for trend = 0.004), vitamin D (OR, 0.38; 95% CI, 0.18-0.82, P= 0.003), and calcium (OR, 0.39; 95% CI, 0.17-0.89, P= 0.02) were inversely associated with EC. Our results suggest that dietary vitamin D and calcium play an important role in the development of EC, although the mechanisms postulated should be explained with additional studies with large populations.

Adolescent↗
PubMedDate not supplied

Perceptions of nurses with regard to doctor-patient communication.

The objective of this study was to evaluate nurses' perceptions of communication between doctors and patients with cancer, AIDS and rheumatoid arthritis. A cross-sectional study was conducted with 741 nurses in 12 hospitals. Nurses received a self-questionnaire that included questions on personal value and attitudes. The answers were used in constructing affective variables (religious beliefs, attitude towards death, paternalism). The prevalence of explicit communication in 'nurse perception of doctor-patient communication' in the case of cancer was 4.5%, with AIDS 30%, and with rheumatoid arthritis 41.8%. When the value of communication was evaluated, it became evident that the likelihood of a nurse perceiving explicit communication in reference to a diagnosis of cancer was 6.5 time greater when communication was considered to be of greater value (CI 95% 2.6-6.6). For nurses who accept the possibility of death, the likelihood of perceiving explicit communication in the case of AIDs was 7.4 times greater than for nurses who deny this possibility (CI 95% 3.7-14.7), and when nurses displayed a deeply religious attitude, the likelihood of perceiving explicit communication was 80% greater than for nurses without this attitude (CI 95% 1.1-2.9). Nurses participate actively in the process of attending to patients with cancer and other disabling illnesses. Thus, there is a need for health professionals who provide compassionate attention, which will improve the various interrelationships between nurses and patients.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Knowledge of health professionals about the prevention of cancer the cervix. Alternatives to medical education].

OBJECTIVE: Several studies have shown the importance of health care professionals as predictors of the use of cervical cancer screening (CCS). MATERIAL AND METHODS: A cross-sectional study of 520 health care professionals in the State of Morelos during 1998, in order to evaluate and quantify their level of knowledge on the impact, etiology, screening, diagnosis and treatment of cervical cancer. A 1 to 10 scale questionnaire was given, and the sample included family medicine specialists, general practitioners, specialist and general nurses, and social workers. Statistical analysis included analysis of variance and 95% confidence intervals. RESULTS: A knowledge mean of 4.74 (95% CI 4.57-4.88) was observed for a scale of 10; specialist physicians scored higher (mean 5.21, 95% CI 4.81-5.60) than social workers (mean 3.07, 95% CI 2.31-3.82). Periodicity of the Pap test in most cases was less than 1 year and there was poor consensus about the age period during which the Pap test should be obtained. The knowledge level was lower when trying to identify etiologic aspects and treatment perspectives. CONCLUSIONS: The results of this study show that, besides the improvement of undergraduate academic programs, it is necessary to improve educational interventions for health care professionals through the updating, recycling, training, health education, and continuing medical education, among others, to promote professional competence and thus improve the quality of medical care.

Clinical Competence↗