Stability of unstimulated and stimulated whole saliva flow rates in children.

OBJECTIVE: To analyze the stability of the unstimulated saliva flow rate (USFR) and the stimulated saliva flow rate (SSFR) in children followed from age 7 to 12 years old. METHODS: Longitudinal study. Whole saliva samples were collected from school children (50 girls and 50 boys). Forty-four girls and 32 boys remained in this cohort for 6 years (dropout rate 24%). Variables that could influence USFR or SSFR patterns were analyzed in a repeated-measures manova. RESULTS: Over a 6-year follow-up, the children's USFR ranged from 0.41 to 0.46 mL/min in the initial and final observation, respectively, and showed no significant differences (P = 0.4455) during the follow-up. The children consistently belonged to one of three distinct SSFR groups (P < 0.0001). A repeated-measures manova model showed that USFR and SSFR were not associated with sex, body mass index, or indoor temperature during sampling. CONCLUSION: These results indicate that USFR and SSFR patterns were stable from 7 to 12 years old. This finding may be useful in oral health prevention or treatment and in the search for biomarkers in saliva for screening or diagnostic purposes.

[Level of clinical competence in seven cohorts of medical students at the end of the internship]. / Grado de competencia clínica de siete generaciones de estudiantes al término del internado médico de pregrado.

INTRODUCTION: Objective structured clinical examination is the instrument with more validated evidence to assess the degree of clinical competence of medical students. OBJECTIVES: To assess the degree of clinical competence of medical students at the end of their internship; to assess the reliability of the instruments with G theory. METHODS: This was an observational, longitudinal, and comparative study. The target population was composed of 5,399 interns of seven generations that finished their internship at the Faculty of Medicine of UNAM, between 2009 and 2015. The instrument used was 18 OSCE stations, three in each subject of the internship. RESULTS: The undergraduate medical interns show a sufficient degree of clinical competence to be general practitioners. The laboratory interpretation and physical examination had the highest scores. The interpretation of imaging studies was the component with the lowest score. The Family Medicine disciplinal area had the highest average score in the OSCE; in contrast, Pediatrics obtained the lowest score on average. The reliability was measured with Generalizability Theory and ranged between 0.81 and 0.93. CONCLUSIONS: The clinical competence of undergraduate medical interns is considered sufficient. The results also show the subjects that require educational interventions to improve clinical competence of students.

A Water and Education Provision Intervention Modifies the Diet in Overweight Mexican Women in a Randomized Controlled Trial.

BACKGROUND: There is minimal information on the impact of replacing sugar-sweetened beverage (SSB) consumption with water on diet quality from randomized controlled trials. OBJECTIVE: We evaluated the effect of a water intake intervention on diet quality in overweight Mexican women. METHODS: Women with a body mass index ≥25 and <39, 18-45 y old, and a self-reported high intake of SSBs (≥250 kcal/d) were randomly allocated to either the water and education provision (WEP) group (n = 120) or the education provision (EP) only group (n = 120). Each group received monthly nutrition counseling, and the WEP group received biweekly water deliveries for 9 mo. Three 24-h recalls, anthropometry, and demographic information were collected at baseline, and 3, 6, and 9 mo. Energy, macronutrient, sugar, SSB, fruit and vegetable, salty snack, cake and cookie, and fast food intakes were assessed in study completers (n = 189) classified by intervention assignment and by actual water intake at every time point (low <1200 vs. high ≥1200 mL/d). RESULTS: The WEP group reported greater decreases in SSB intake than the EP group (from 20.9% to 10.3% of energy/d vs. from 20.1% to 17.8%). Thirty-eight percent of the EP group and 84.3% of the WEP group reported attaining a water intake ≥1200 mL/d. Reductions in energy intake and food groups were similar across intervention groups. However, the high actual water intake group reported greater increases vs. the lower intake group in intake of fruits and vegetables (117 vs. 47 g/d), as well as larger reductions in salty snacks (4.6 vs. 0.7 g/d) and cakes and cookies (31.7 vs. 14.7 g/d). CONCLUSIONS: Other than SSBs, improvements in food group intake did not differ by intervention group in overweight Mexican women. However, post hoc analyses suggested that achieving a high actual water intake was associated with additional beneficial changes in food group intake. This trial was registered at clinicaltrials.gov as NCT01245010.

[Clinical competence evaluation using the Objective Structured Clinical Examination (OSCE) in medical internship at UNAM]. / Evaluación de la competencia clínica con el examen clínico objetivo estructurado en el internado médico de la Universidad Nacional Autónoma de México.

INTRODUCTION: The Objective Structured Clinical Examination (OSCE) is a widely used measurement tool to assess clinical competence in the health sciences. There is little published evidence of its use in Mexican medical schools. OBJECTIVE: To assess clinical competence in medical students with an OSCE, before and after the Medical Internship. METHODS: Prospective cohort study, pre- post-test research design. The assessed population was medical students at UNAM Faculty of Medicine in Mexico in their Internship year. The instrument was an 18-stations OSCE, three stations per academic area of the Internship curriculum. RESULTS: We assessed the clinical competence of 278 students in a pretest OSCE when starting the Internship year, and tested them 10 months later with an equivalent post-test OSCE. The sample of students was 30.4% of the total Internship population. Test reliability with Cronbach's alpha was 0.62 in the pre-test and 0.64 in the post-test. The global mean score in the pretest OSCE was 55.6 ± 6.6 and in the post-test 63.2 ± 5.7 (p < 0.001), with a Cohen's d of 1.2. CONCLUSIONS: The clinical competence of medical students measured with an OSCE is higher after the medical internship year. This difference suggests that the internship can influence the development of clinical competence in medical students.

Systemic Sclerosis: Elevated Levels of Leukotrienes in Saliva and Plasma Are Associated with Vascular Manifestations and Nailfold Capillaroscopic Abnormalities.

The role of leukotrienes (LTs) in the pathogenesis of systemic sclerosis (SSc) needs clarification. We analyzed the association of salivary (sa) and plasma (p) levels (pg/mL) of cysteinyl-leukotrienes (CysLT) and LTB4 with SSc vascular manifestations and nailfold capillaroscopy (NFC) in a cross-sectional study. Patients and healthy controls were evaluated for vascular manifestations and NFC. LTs were compared between groups as follows: SSc with or SSc without vascular features and controls, and by NFC parameters. Twenty SSc patients and 16 volunteers were recruited; Raynaud's phenomenon (RP) history (SSc: saCysLT 99.4 ± 21.8 vs. controls: 23.05 ± 23.7, p = 0.01), RP at examination (SSc: saCysLT 129.3 ± 24.6 vs. controls: 23.05 ± 22.46, p = 0.01; pCysLT SSc: 87.5 ± 11.2 vs. controls: 32.37 ± 10.75, p = 0.002), capillary loss (saCysLT 138.6 ± 26.7 vs. 23.05 ± 21.6, p = 0.0007; saLTB4 3380.9 ± 426.6 vs. 1216.33 ± 346.1, p = 0.0005), "late" scleroderma pattern vs. controls (saCysLT 205.6 ± 32 vs. 23 ± 19.6, p = 0.0002; saLTB4 4564.9 ± 503.6 vs. 1216.3 ± 308.3; p < 0.0001) were all significant. Late patterns had higher levels (saCysLT, p = 0.002; LTB4 p = 0.0006) compared to active and early patterns (LTB4, p = 0.0006), and giant capillaries (p = 0.01) showed higher levels of LTs. Levels of pCysLT were higher in patients with RP at examination vs. patients without RP; saCysLT and LTB4 were higher in SSc group with vs. without capillary loss. LTs could be involved in the pathophysiology of vascular abnormalities. Further research is required to determine if blocking LTs could be a therapeutic target for SSc vascular manifestations.

Social Class for Collective Health Research: A Conceptual and Empirical Challenge.

Social Determination of Health (SDH)/Collective Health is a Latin American framework that sees the Marxist core concept of social class as fundamental for understanding health inequalities. In contrast to social stratification approaches, Marxist proposals seek to understand health as part of the historical transformations of capitalism's mode of production. In this article we aim to analyze the relationship between social class and health inequalities using data from the IV Oral Health National Study in Colombia. We conducted hierarchical cluster analyses to classify the population in five class positions and three living conditions clusters, which reflect how the spheres of production and social reproduction relate to social classes in Colombia. To measure oral health we use DMFT, as well as care and treatment needs indexes. Through variance analysis models we found that people from more exploited class positions and worse living conditions have more active disease and higher treatment needs. Despite technical and conceptual challenges, we conclude that a social class analytical framework can be operationalised via the interrelated spheres of production and social reproduction, which sheds light on the relationship between health inequalities and the class structure of the capitalist system.

Maternal dietary omega fatty acid intake and auditory brainstem-evoked potentials in Mexican infants born at term: cluster analysis.

OBJECTIVE: To identify biological and socioeconomic factors associated with the neurological development of Mexican infants born at term, as measured by brainstem auditory-evoked potentials (BAEPs). SUBJECTS AND METHODS: We conducted a cohort study among 76 women with low risk pregnancies recruited in their third trimester of pregnancy and followed their infants until 12 months of age. BAEP tests were conducted on the infants before 3 months of age during physiologic sleep, using 100 msec bipolar clicks. Maternal dietary intake was evaluated by food frequency questionnaire. Two BAEP groups (short latency, long latency) were identified by cluster analysis. The association between BAEP group and maternal PUFAs was estimated using logistic regression models adjusted for socioeconomic and biological factors. RESULTS: Short latency BAEPs were associated with a maternal diet rich in arachidonic acid (OR=3.63, 95% CI 1.23-10.67) after adjusting for age (in days) sex, head circumference and gestational age but was not significantly associated to a maternal diet rich in docosahexaenoic acid (DHA). CONCLUSIONS: Our results suggest the importance of arachidonic acid intake during pregnancy for short latency BAEPs and adequate fetal myelination.

[Tobacco smoking in urban and rural adolescents and its association with individual and familiar characteristics]. / Tabaquismo en adolescentes del medio urbano y rural. Caracteristicas individuales y familiares asociadas.

OBJECTIVE: The purpose was to estimate the prevalence of smoking in adolescents and its association with some individual and family characteristics in urban and rural areas. METHODS: An analytic cross-sectional study was carried out in 3161 junior high school students, of eight public and two private urban schools and three public rural schools. Some student behaviors on tobacco use, patterns of smoking and alcohol consumption in the family and socioeconomic status were measured. RESULTS: The prevalence of smoking increased with age. In private urban schools, women had a higher prevalence that males (27.6 % vs. 19.3 %). In rural area schools was higher in males (9.9 % vs. 3.5 %). Individual characteristics associated with smoking were: the curiosity to smoke (OR = 9.7, CI 95 % = 5.8-16.3), having experienced with smoking (OR = 26, CI 95% = 12-56.6) and alcohol consumption (OR = 2.9, CI 95 % = 2.1-3.9). The family characteristics that influence adolescent smoking were the presence of smoking habit in the father (OR = 1.5, CI 95% = 1.1-2) or in the brother or sister (OR = 2, CI 95 % = 1.3-3). The parents living together (OR = 0.6, CI 95 % = 0.4-0.9) was a protective factor. CONCLUSIONS: The exploratory behavior of the adolescent and the patterns of tobacco use and alcohol consumption in the family influenced the adoption of this habit.

Prevalence of anemia and deficiency of iron, folic acid, and zinc in children younger than 2 years of age who use the health services provided by the Mexican Social Security Institute.

BACKGROUND: In Mexico, as in other developing countries, micronutrient deficiencies are common in infants between 6 and 24 months of age and are an important public health problem. The objective of this study was to determine the prevalence of anemia and of iron, folic acid, and zinc deficiencies in Mexican children under 2 years of age who use the health care services provided by the Mexican Institute for Social Security (IMSS). METHODS: A nationwide survey was conducted with a representative sample of children younger than 2 years of age, beneficiaries, and users of health care services provided by IMSS through its regular regimen (located in urban populations) and its Oportunidades program (services offered in rural areas). A subsample of 4,955 clinically healthy children was studied to determine their micronutrient status. A venous blood sample was drawn to determine hemoglobin, serum ferritin, percent of transferrin saturation, zinc, and folic acid. Descriptive statistics include point estimates and 95% confidence intervals for the sample and projections for the larger population from which the sample was drawn. RESULTS: Twenty percent of children younger than 2 years of age had anemia, and 27.8% (rural) to 32.6% (urban) had iron deficiency; more than 50% of anemia was not associated with low ferritin concentrations. Iron stores were more depleted as age increased. Low serum zinc and folic acid deficiencies were 28% and 10%, respectively, in the urban areas, and 13% and 8%, respectively, in rural areas. The prevalence of simultaneous iron and zinc deficiencies was 9.2% and 2.7% in urban and rural areas. Children with anemia have higher percentages of folic acid deficiency than children with normal iron status. CONCLUSION: Iron and zinc deficiencies constitute the principal micronutrient deficiencies in Mexican children younger than 2 years old who use the health care services provided by IMSS. Anemia not associated with low ferritin values was more prevalent than iron-deficiency anemia. The presence of micronutrient deficiencies at this early age calls for effective preventive public nutrition programs to address them.

Reliability analysis of the objective structured clinical examination using generalizability theory.

BACKGROUND: The objective structured clinical examination (OSCE) is a widely used method for assessing clinical competence in health sciences education. Studies using this method have shown evidence of validity and reliability. There are no published studies of OSCE reliability measurement with generalizability theory (G-theory) in Latin America. The aims of this study were to assess the reliability of an OSCE in medical students using G-theory and explore its usefulness for quality improvement. METHODS: An observational cross-sectional study was conducted at National Autonomous University of Mexico (UNAM) Faculty of Medicine in Mexico City. A total of 278 fifth-year medical students were assessed with an 18-station OSCE in a summative end-of-career final examination. There were four exam versions. G-theory with a crossover random effects design was used to identify the main sources of variance. Examiners, standardized patients, and cases were considered as a single facet of analysis. RESULTS: The exam was applied to 278 medical students. The OSCE had a generalizability coefficient of 0.93. The major components of variance were stations, students, and residual error. The sites and the versions of the tests had minimum variance. CONCLUSIONS: Our study achieved a G coefficient similar to that found in other reports, which is acceptable for summative tests. G-theory allows the estimation of the magnitude of multiple sources of error and helps decision makers to determine the number of stations, test versions, and examiners needed to obtain reliable measurements.

[The debate on lower back pain and its relationship to work: a retrospective study of workers on sick leave]. / La polémica sobre las lumbalgias y su relación con el trabajo: estudio retrospectivo en trabajadores con invalidez.

Lower back pain has a high prevalence among the Mexican working population, with extensive social and economic repercussions. Official figures show that lower back pain accounts for 10.0 to 15.0% of sick leave excuses. However, this fails to identify any relationship between lower back pain and job conditions, since such leave is only granted if it can be shown that the condition was not work-related. The present study shows that such a relationship does in fact exist. A retrospective study examined all cases (n = 210) in which workers were granted sick leave for lower back pain in an IMSS (Mexican Government Health Insurance) hospital in Mexico City during a seven-year period. The results show the association and interactions between debilitating lower back pain and several work-related variables: job position, time-on-the-job, and physical effort and weight-carrying associated with the position. Causes of lower back pain and the difficulty in obtaining accurate, precise back pain diagnosis are discussed. A number of clinical, epidemiological, and legal strategies for the study and prevention of back pain are suggested.

Computer use increases the risk of musculoskeletal disorders among newspaper office workers.

BACKGROUND: Our objectives were to estimate prevalence of musculoskeletal disorders among office workers at a newspaper in Mexico City, analyze the relationship between musculoskeletal disorders and use of the personal computer (PC) and associated ergonomic factors in the aforementioned population, and to analyze the modifying effect that psychosocial factors have on the relationship between ergonomic factors and musculoskeletal disorders and extant jobs at the newspaper. METHODS: A total of 73% (218 of 298) of office workers at a newspaper were studied. Information was collected by a questionnaire completed by participants. Cases for work-related musculoskeletal disorder in hands (WMSD-H), upper extremity (WMSD-UE), and back (WMSD-B) were established. Working conditions, computer use, and ergonomic and psychosocial factors were studied as independent variables. To study the relationship between musculoskeletal disorders and independent variables, prevalence ratios adjusted for potential confounders (sex, age, educational level, and marital status) were estimated. RESULTS: Risk of musculoskeletal disorders was greater among workers at the newspaper who used computers, those involved in editing work, and those who adopted uncomfortable positions. The modifying effect of psychosocial factors was observed only in the relationship between ergonomic factors and WMSD-B because among workers with control over work, WMSD-B risk was reduced by the greater number of work breaks. Among workers without social support, increase in number of postures and rotation/inclination of the neck was associated with substantial risk increase, while amid workers under psychological demand number of PC tasks and number of rest pauses were associated with increase in WMSD-B risk. CONCLUSIONS: The findings of our study showed that PC use increased risk of developing musculoskeletal disorders (WMSD-H and WMSD-UE). Such an increase is mediated by ergonomic factors such as mouse use, remaining seated for prolonged periods, adoption of inadequate or uncomfortable postures, performing certain PC tasks, and psychosocial factors.

Healing of chronic arterial and venous leg ulcers through systemic effects of electromagnetic fields [corrected].

BACKGROUND: Mitogen-activated autologous peripheral blood mononuclear cells applied locally on the ulcer surface promote healing of chronic arterial and venous leg ulcers. In vitro, extremely low frequency electromagnetic fields (ELF) interact with peripheral blood mononuclear cells (PBMC) via Ca++ channels, activating signal transduction cascades, promoting cytokine synthesis, and changing cell proliferation patterns. METHODS: ELF frequencies were configured to interact in vitro with the proliferation patterns of PBMC obtained from normal human volunteers. These ELF were then applied peripherally as the sole treatment to 26 patients with 42 chronic leg ulcers of predominantly arterial or venous etiology unresponsive to previous medical and/or surgical treatments in a phase I before-after design. RESULTS: At admission, age of ulcers had a skewed distribution with a median of 639 days. Wound healing or deleterious effects began in all patients during the first 2 weeks after ELF exposure, permitting their previously unresponsive ulcers to function as internal controls. After ELF exposure, 69% of all lesions were cured or healed >50% in a period <4 months. Defective wound healing was observed in lesions associated with important arterial occlusion, uncontrolled arterial hypertension, severe lipodermatosclerosis, non-pitting edema, and obesity (body mass index >30). Lesions worsened in patients with autoimmune diseases. CONCLUSIONS: Systemic effects are hypothetically explained by ELF activation of PBMC and their subsequent transportation to the ulcer site via humoral route. This therapy is effective in selected patients with chronic arterial and venous leg ulcers.

Esophageal anastomotic failure: an experimental study.

BACKGROUND: Postsurgical complications in patients with esophageal atresia have remained unchanged during the last three decades. This study was aimed at investigating certain risk factors for small-sized esophageal anastomosis and to assess the probable relationship between esophageal length and body weight in rabbit. METHODS: Six groups of 10 adult rabbits were subjected to section or 1-cm segmental resection of thoracic esophagus followed by end-to-end anastomosis. Approximation strength of esophageal ends was measured. Three different suture materials were used, and three different surgeons carried out procedures. Observed morbidity was recorded, as well as leakage or stenosis frequency in suture line. Esophageal length and body weight of nonresected rabbits were measured. RESULTS: Fifteen leakages were observed in suture line; there were no differences in relative risk between groups with and without resection, or in ratio of this complication among surgeons; nonetheless, a greater number of leakages (p < 0.05) was observed at higher tension. There were no differences in magnitude of stenosis among surgeons, tension degree, or suture material used. Quadratic association was found between length of thoracic esophagus and body weight in nonresected rabbits. CONCLUSIONS: Rabbit esophagus is a suitable model to assess early surgical complications but not for late complications. Among three assessed factors, increased tension in patients with segmental deficit was the most significant factor in development of anastomotic leakage. Existence of nonlineal correlation between esophageal length and body weight in rabbit showed that resection of 1 cm of esophagus represented a different weight-dependent segmental deficit, which increased as weight decreased.

Prediction equations for spirometric parameters in Mexican adult population.

BACKGROUND: Our objective was to develop prediction equations for spirometric parameters that included the following: forced vital capacity (FVC); 1st-sec forced expiratory volume (FEV1); FEV1/FVC ratio; peak expiratory flow (PEF); maximal expiratory flow 50% FVC (VF50) and maximal expiratory flow 75% FVC (VF75); maximal mid-expiratory flow (FEF25-75), and forced late expiratory flow rate (FEF75-85) in a sample of adult Mexican population of both sexes. Age and height variables were utilized. METHODS: Spirometric studies were carried out, observing the international recommendations and norms in force and effected under basal conditions and post-bronchodilator. Linear regression equations were generated based on gender, age, and height. For each spirometric parameter, we selected a linear model. Studies were carried out with spirometry that was in agreement with quality criteria recommended by the American Thoracic Society (ATS). Bronchodilatator administration allowed for elimination of subjects with subclinical bronchial hyperreactivity RESULTS: We studied 436 patients with normal clinical radiographic and pulmonary function, with negative smoking and age range between 17 and 63 years; 206 were females and 230, males. Linear regression equations obtained had direct linear correlation with height and inverse linear correlation with age; in addition, equations had a determination coefficient equal to or less than those reported by authors recommended by the ATS. CONCLUSIONS: Equations obtained in this study possessed the quality required for application in adult Mexican population exposed or not to occupational and environmental contaminants.

A cluster analysis model for caries risk assessment.

Cluster analysis was applied to determine, the natural grouping of individuals, among sixty 8-10-year-old children, and to identify the most significant set of markers for risk assessment. The risk clusters were obtained with initial clinical and bacteriological measurements including dmf + DMFS, active caries, mutans streptococci and lactobacilli counts in plaque or saliva on two media, and Snyder's test results. The morbidity clusters were constructed with the final clinical indexes and incidence after 18 months (dependent variables). A risk cluster was identified that included the following significant initial variables; dmf + DMFS, active caries, counts of mutans streptococci from plaque on TSY20B and lactobacilli in saliva, and Snyder's test results. This set of markers identified 86% of the children at high risk who developed high morbidity, as well as 94% of children in the low-risk cluster who developed low or no caries. The results of this investigation provide the basis to develop a system for caries risk assessment.

Aflatoxin (B1 , B2 , G1 , and G2 ) contamination in rice of Mexico and Spain, from local sources or imported.

Rice is an important cereal but it is often contaminated with aflatoxins (AFs). The purpose of this study was to identify and quantify AF (B1 , B2 , G1 , and G2 ) in 67 rice samples cultivated in Mexico and Spain, and from imported crops collected in 2008 and 2009. The methodology was validated, the rice samples were concentrated and purified with immunoaffinity columns and were quantified by high-pressure liquid chromatography (HPLC). The average total AF (AFt) in the Spanish rice was 37.3 µg/kg, the range was from 1.6 to 1383 µg/kg, the most contaminated samples being from San Juan de Aznalfarache, Sevilla (AFt = 138.6 µg/kg), from Tortosa, Tarragona (AFt = 104.6 µg/kg), and Calasparra, Murcia (AFt = 103.9 µg/kg). The rice imported from France to Spain had AFt of 26.6 µg/kg and from Pakistan AFt of 18.4 µg/kg, showing less AF contamination than the local one. The rice which originated from Mexico contained (AFt = 16.9 µg/kg), and those imported from the United States (AFt = 14.4 µg/kg) and Uruguay (AFt = 15.6 µg/kg). The imported rice had better quality in terms of the presence of AFs.

Tracheal dimensions in the Mexican population.

BACKGROUND: There are few studies regarding the measurement of tracheal dimensions. Most are focused on morphology and tracheal development. The aim of this study was to determine the length and tracheal diameter of adults in our population and its correlation with external measurements. METHODS: The study design was prospective, observational and descriptive. We included a nonrandom sampling of deaths of Mexican national citizens who were between 18 and 65 year old. The study period was from June 1 to November 30, 2009, and the study was carried out at the facilities of the Forensic Medical Service of the Federal District, Mexico. Standardized measurements of tracheal diameter and length were correlated with external measurements. RESULTS: We dissected 44 cadavers, 19 (43%) females and 25 (57%) males. In females the average age was 39.2 ± 13.9 years (range: 19-61 years), average height 161.9 ± 7.4 cm (range: 154-179 cm), tracheal length (TL) 8.6 ± 0.5 cm (range: 7.8-9.5 cm) and transverse diameter (TD) 1.7 ± 0.3 cm (range: 1.3-2.0 cm). Average age of males was 36.4 ± 14.4 years (range: 19-65 years), average height 169.8 ± 6.7 cm (range: 156-184 cm), TL 9.1 ± 0.9 cm (range: 8.0-10.7) and TD 1.9 ± 0.2 cm (range: 1.6-2.3 cm). TL was significantly correlated with sternal length (0.82, p <0.0001) and age (0.56, p = 0.0003). According to gender, there was no significant correlation between TL and height. CONCLUSIONS: We found a low average TL and no significant correlation with height. These data should be considered when carrying out direct procedures on the trachea.

Polymorphisms associated with the risk of lung cancer in a healthy Mexican Mestizo population: Application of the additive model for cancer.

Lung cancer is the leading cause of cancer mortality in Mexico and worldwide. In the past decade, there has been an increase in the number of lung cancer cases in young people, which suggests an important role for genetic background in the etiology of this disease. In this study, we genetically characterized 16 polymorphisms in 12 low penetrance genes (AhR, CYP1A1, CYP2E1, EPHX1, GSTM1, GSTT1, GSTPI, XRCC1, ERCC2, MGMT, CCND1 and TP53) in 382 healthy Mexican Mestizos as the first step in elucidating the genetic structure of this population and identifying high risk individuals. All of the genotypes analyzed were in Hardy-Weinberg equilibrium, but different degrees of linkage were observed for polymorphisms in the CYP1A1 and EPHX1 genes. The genetic variability of this population was distributed in six clusters that were defined based on their genetic characteristics. The use of a polygenic model to assess the additive effect of low penetrance risk alleles identified combinations of risk genotypes that could be useful in predicting a predisposition to lung cancer. Estimation of the level of genetic susceptibility showed that the individual calculated risk value (iCRV) ranged from 1 to 16, with a higher iCRV indicating a greater genetic susceptibility to lung cancer.

Estímulos económicos, exigencias de trabajo y salud en académicos universitarios mexicanos / Economic stimulus, work requirements and health in Mexican university faculty

Establecer la asociación entre las principales exigencias de trabajo y los daños a la salud en académicos que tienen la opción de participar en los programas de estímulos económicos. Estudio transversal y observacional, participaron 192 académicos universitarios con base en un muestreo aleatorio estratificado. Se recabaron datos sociodemográficos, exigencias laborales, perfil de daños a la salud e implicaciones derivadas de la participación en los programas de becas. Se utilizó el JMP8 y se controlaron variables confusoras (edad, género y antigüedad) estableciendo un nivel de significancia de p<0.05. El 64% cuenta con algún tipo de estímulo económico. El perfil de daños a la salud se caracterizó por trastornos músculo-esqueléticos (42%). Las exigencias de trabajo más representativas fueron: laborar en días de descanso (86%), cubrir una cuota de trabajo (80%) y sobrecarga de trabajo (60%); éstas se asociaron significativamente con: lumbalgia, músculo-esqueléticos, túnel del carpo y disfonía. Prevalecen tasas elevadas de trastornos músculo-esqueléticos, lumbalgia y disfonía, entre 3 y 4 de cada 10 trabajadores. Las exigencias laborales para poder concursar en los estímulos económicos se asociaron más significativamente con los daños a la salud, que los propios estímulos como tal. Es necesario visibilizar estos resultados para prevenirlos y atenderlos en materia de salud de los trabajadores.

To examine the association between the main job demands and adverse health effects among Mexican university faculty who have the option of participating in economic stimulus programs. Cross-sectional, observational study, involving a stratified random sample of 192 university academics. Data were collected on sociodemographics, job demands, adverse health profile implications arising from participation in economic incentive programs. The JMP8 was used and the analysis controlled for confounding variables (age, gender and age); statistical significance level was set at p < 0.05. Sixty-four percent of respondents indicated being eligible for some type of economic stimulus. The adverse health profile was characterized by musculoskeletal disorders (42%). The most representative job demands were working on days off (86%), covering for others (80%) and increased workload (60%). These factors were significantly associated with low back pain, musculoskeletal, carpal tunnel syndrome and dysphonia. The prevailing high rates of musculoskeletal disorders, back pain and dysphonia, affected between 3 and 4 out of 10 workers. Job demands required to participate in the economic stimulus were more significantly associated with adverse health than the economic incentives themselves.