Asociación de la tuberculosis pulmonar con los antígenos del sistema HLA en el Noreste de México / Association of pulmonar tuberculosis with HLA system antigens in Northeastern Mexico

Antecedentes: La susceptibilidad genética a tuberculosis pulmonar (TbP) ha sido asociada al sistema HLA (antígenos de los leucocitos humanos) del MHC (complejo mayor de histocompatibilidad), principalmente con los antígenos HLA-DR y -DQ. Dado lo anterior, el objetivo de este estudio caso-control no pareado, fue determinar la asociación de TbP con los antígenos HLA-DR y -DQ en pacientes que asistían a una unidad médica del IMSS. Métodos: Los fenotipos del sistema HLA de casos (n=50) y controles (n=417), se definieron serológicamente por la técnica de microlinfocitotoxicidad dependiente de complemento. Los linfocitos B fueron obtenidos utilizando inmunoperlas. Las frecuencias alélicas y haplotípicas, equilibrio de Hardy-Weinberg y el desequilibrio de ligamiento, se determinaron mediante el programa computacional Arlequín versión 3.01, y el riesgo relativo (RR) mediante el programa Epimax Table Calculator. Resultados: Los alelos HLA-DR11(5), -DR16(2) y -DQ7(3) y los haplotipos /DR11(5)-DQ7(3), /DR14(6)-DQ5(1) y /DR16(2)-DQ7(3) fueron más frecuentes en casos que en controles (RR>1, p<0.05). Los alelos HLA-DR17(3) y DQ8(3) y los haplotipos /DR17(3)-DQ2 y /DR4-DQ8(3) fueron más frecuentes en controles que en casos (RR<1, p<0.05). Conclusiones: Estos resultados sugieren asociación entre TbP y HLA-DR y -DQ en esta población mestiza mexicana y son similares a los encontrados en otros estudios caso-control no pareados a nivel mundial.

BACKGROUND: Genetic susceptibility to pulmonary tuberculosis (PTb) has been associated with the HLA (Antigens of the Human Leukocytes) system of the MHC (Major Histocompatibility Complex), mainly with HLA-DR and-DQ antigens. Based on this assumption we carried out a case control study to determine the association of PTb with the HLA-DR and-DQ antigens among a sample of patients attending a medical unit belonging to the Mexican Social Security System (IMSS). METHODS: HLA system phenotypes from cases (n=50) and controls (n=417), were defined serologically using a complement dependent microlymphocytotoxic assay. B lymphocytes were obtained using immunobeads. The allele and haplotype frequencies were determined using the Arlequin version 3.01 computer software. Relative risk (RR) was calculated with the Epimax Table Calculator. RESULTS: The alelles HLA-DR11(5), -DR16(2) and -DQ7(3) and haplotypes /DR11(5)-DQ7(3), /DR14(6)-DQS(1) and /DR16(2)-DQ7(3) had a higher frequency in cases than in controls (RR>1, p<0.05). The HLA-DR17(3) and DQ8(3) alelles and /DR17(3)-DQ2 and /DR4-DQ8(3) haplotypes had a higher frequency among controls than among cases (RR<1, p<.05). CONCLUSIONS: These results indicate an association between PTb with the HLA-DR and -DQ antigens in a Mexican sample. Our results are similar to those found in the international literature.

Mutagenic activity of diazepan evaluated by in vivo cytogenetic tests

Background. Diazepam, one of the benzodiazepine group of tranquilizers, in used as an adjunctive drug for sedation and for relief of anxiety in the treatment of epilepsy. Suspicion has been aroused of a possible mutagenic and teratogenic effect of this drug, thus the potential for cancer development. Methods. To analyze the mutagenic effect of diazepam, the micronuclei and sister chromatid exchange (SCE) tests were performed by in vivo techniques in the bone marrow of Balb-C mice after intraperitoneal drug administration. Sixty mice, 30 males and 30 females, were classified as negative control (n=12), positive control (n=12), and three groups were treated with diazepam (n=36). All groups were matched by sex, and each mouse received a single intraperitoneal injection. Negative control group was injected with physiological saline, positive control group with mitomycin-C at a dose of 0.5 mg/kg of body weight. Treated groups received diazepam, one at 0.1, the other at 0.2, and the last, at 0.4 mg/kg. Results. The results showed a significant increase in the frequency of micronucleated polychromatic erythrocites at all doses tested for whole population in relation to negative control. The polychromatic/normochromatic erythrocyte ratio showed a significante decrease at doses of 0.1 and 0.4 mg/kg in relation to negative control, the male mice being those affected. Conclusions. It is concluded that diazepam showed mutagenic and genotoxic effects on bone marrow cells of mice and that it might represent a human health risk

Activity satellite association and polymorphismo of Ag stained nucleolus organizer regions (Ag+ NORs) in lymphocytes from women with cervical uterine cancer

Thirty five female patients with different stages of neoplastic lesions: cervical intraepithelial neoplasia (CIN) or dysplasia (CIN I and CIN II), in situ carcinoma (CIS), and adenocarcinoma, and 27 healthy women (controls) wee studied to determine the activity, satellite association, and jpolymorphism of Ag stained nucleolus organizer regions (Ag+NORs) in acrocentric chromosomes in metaphases obtained from peripheral blood lymphocytes. For each person, 25 to 50 metaphases stained with ammoniacal silver technique were scored. The average number of Ag+ NORs was higher in women with adenocarcinoma (7.66 ñ 0.72) than in controls (6.65 ñ 0.74). Non-associated chromosomes showing Ag+ NORs were found more frequently in patients (5.85 ñ 0.88) than in controls (4.81 ñ 0.67). Patients aged 30-39 and 60 or more had an increase of Ag+ NORs (7.99 ñ 1.04, and 7.81 ñ0.71) with respect to their controls (6.36 ñ 0.052 and 6.17 ñ 0.88), but the frequency of satellite association showed lower values in 50 -59 year-old patients (0.75 ñ 0.08) than in controls (1.02 ñ 0.19). The most frequent association in patients was the large type (patients = 38.96 perecent, controls 30.49 ). The partial association showed higher values (6.49 percent) than controls (2.44 percent). Otherwise, the spherical association was more frequent for controls (37.80 percent) than for patients (28.57 percent). All these differences were statistically significant (p<0.05). The frequency of Ag+ NORs and the type of polymorphism of satellite association could be related to the neoplastic process, while the frequency of satellite association and of polymorphism of Ag+ NORs seems to be irrelevant

Risk estimation of ABO and Rho(D) incompatibility in persons with mono- and polyphyletic surnames in Monterrey, Mexico: comparison with other Mexican population

ABO and Rho(D) blood groups were determined in 3813 males and females affiliated with the Instituto Mexicano del Seguro Social (IMSS) who are residents of the Monterrey Metropolitan Area (MMA) in northeastern Mexico. They were selected by their monophyletic or polyphyletic surnames. The ABO and Rho(D) blood group phenotypes and gene frequencies were determined and based upon these, the risk of incompatibilities was estimated for both marriages (MI) and maternal-fetal incompatibility (MFI). These were compared with those estimated for other populations of residents in the MMA, and in other locations in Mexico, as well as with the two most important ancestral populations, Spanish and Tlaxcaltecan Mexican Indians, with the hypothesis that the percent of risk ABO and Rho(D) MI and MFI are greater in the population with monophyletic surnames than those with polyphyletic surnames. It was found that for persons with nomophyletic and polyphyletic surnames, as well as for the other populations in the MMA and other places in Mexico, their ABO and Rho(D) MI and MFI percent of risk are intermediate to the ones estimated for their ancestry. The percentages of MI and MFI are higher for the persons with monophyletic than for the ones with polyphyletic surnames, other populations from the MMA and those from other locations in Mexico. The risks are higher when the similarity with Spanish increases and are lower when their similarities with the mexican Indians increase

Algunos factores epidemiológicos en el cáncer cervicouterino / Certain epidemiologic factors of cervico-uterine cancer

Colateralmente a un estudio citogenético se entrevisto a un grupo de 44 pacientes que acudían por primera vez a la consulta de oncología del Hospital Regional de Especialidades No. 23 "Dr. Ignacio Morones Prieto", Monterrey, N.L., del Instituto Mexicano del Seguro Social, las cuales presentaban alguna alteración neoplásica cervicouterina, y a 45 mujeres sin ningún padecimiento neoplásico que fueron consideradas como grupo control, a las que se les interrogó sobre algunos antecedentes ginecoobstétricos y además se les determinaron los grupos sanguíneos y Rh (D). Los resultado obtenidos indicaron que el cáncer invasor en estadio II es el padecimiento neoplásico cervicouterino más común (25 por ciento), siendo la cuarta década de la vida la etapa en la que mayormente se diagnosticó y tiende a presentarse en mujeres que inicaron relaciones sexuales a edad temprana. Se manifiesta también con más frecuencia en multigestas, en mujeres que presentan antecedentes de uno o más abortos, y en aquéllas que hayan utilizado anticonceptivos orales o dispositivo intrauterino (DIU) como mecanismo de control de la natalidad