Metabolic Biomarkers in Adults with Type 2 Diabetes: The Role of PPAR-γ2 and PPAR-ß/δ Polymorphisms.

Glucose and lipid metabolism regulation by the peroxisome proliferator-activated receptors (PPARs) has been extensively reported. However, the role of their polymorphisms remains unclear. OBJECTIVE: To determine the relation between PPAR-γ2 rs1801282 (Pro12Ala) and PPAR-ß/δ rs2016520 (+294T/C) polymorphisms and metabolic biomarkers in adults with type 2 diabetes (T2D). MATERIALS AND METHODS: We included 314 patients with T2D. Information on anthropometric, fasting plasma glucose (FPG), HbA1c and lipid profile measurements was taken from clinical records. Genomic DNA was obtained from peripheral blood. End-point PCR was used for PPAR-γ2 rs1801282, while for PPAR-ß/δ rs2016520 the PCR product was digested with Bsl-I enzyme. Data were compared with parametric or non-parametric tests. Multivariate models were used to adjust for covariates and interaction effects. RESULTS: minor allele frequency was 12.42% for PPAR-γ2 rs1801282-G and 13.85% for PPAR-ß/δ rs2016520-C. Both polymorphisms were related to waist circumference; they showed independent effects on HbA1c, while they interacted for FPG; carriers of both PPAR minor alleles had the highest values. Interactions between FPG and polymorphisms were identified in their relation to triglyceride level. CONCLUSIONS: PPAR-γ2 rs1801282 and PPAR-ß/δ rs2016520 polymorphisms are associated with anthropometric, glucose, and lipid metabolism biomarkers in T2D patients. Further research is required on the molecular mechanisms involved.

Early-Life Metabolic Traits and Physical Fitness in Tarahumara, Mennonite, and Mestizo Adolescents from Northern Mexico.

The WHO identifies high BMI, high blood pressure, and high fasting plasma glucose as chronic disease risk factors, whereas physical fitness is identified as a protective behavioral factor. This study responds to the rising interest in assessing metabolic factors and physical activity within young populations of Mestizo, Tarahumara, and Mennonite from Chihuahua Mexico, due to its strong relationship with disease development and low well-being. A cross-sectional study was conducted with 201 teenagers from rural towns in Northern Mexico, and relationships between physical fitness and cardio-metabolic risk related to anthropometric, glycolipid, and vascular function factors were assessed. ANOVA-tested differences among ethnic groups using physical fitness as a grouping variable and measures of cardio-metabolic risks were used as dependent variables. A stepwise regression analysis allowed us to identify the best predictors for physical fitness. Clinical risk factors were analyzed by ethnic group and sex. No differences were found among ethnic groups in physical fitness and cardio-metabolic health risks; sex differentiated higher health risks related to behavioral factors, since young women showed lower physical fitness across ethnicities. Clinically, the Mestizo sample showed higher numbers of individuals with one risk factor. Mennonites showed a high frequency of anthropometric and fitness health risks with low glycolipid and vascular risks. Tarahumara had fewer risk factors as compared with both Mestizo and Mennonite. Rural populations are harder to reach, both for health assessment and intervention; health professionals must work close to local community organizations to gain access.

Pro12Ala PPAR-γ2 and +294T/C PPAR-δ Polymorphisms and Association with Metabolic Traits in Teenagers from Northern Mexico.

Peroxisome proliferator-activated receptors (PPARs) play roles in glucose and lipid metabolism regulation. Pro12Ala PPAR-γ2 and +294T/C PPAR-δ have been associated with dyslipidemia, hyperglycemia and high body mass index (BMI). We compared metabolic traits and determined associations with Pro12Ala PPAR-γ2 or +294T/C PPAR-δ polymorphism among teenagers from different ethnicity. Four hundred and twelve samples with previous biochemical and biometric measurements were used. Genomic DNA from peripheral blood was extracted and analyzed by end-point PCR for Pro12Ala PPAR-γ2. The +294T/C PPAR-δ PCR product was also digested with Bsl I. Two genotype groups were formed: major allele homozygous and minor allele carriers. Pro12Ala PPAR-γ2 G minor allele frequencies were: 10% in Mestizo-1, 19% in Mestizo-2, 23% in Tarahumara, 12% in Mennonite, and 17% in the total studied population. The +294T/C PPAR-δ C minor allele frequencies were: 18% in Mestizo-1, 20% in Mestizo-2, 6% in Tarahumara, 13% in Mennonite, and 12% in the total studied population. Teenagers with PPAR-γ2 G allele showed a greater risk for either high waist/height ratio or low high-density lipoprotein; and, also had lower total cholesterol. Whereas, PPAR-γ2 G allele showed lower overweight/obesity phenotype (BMI Z-score) frequency, PPAR-δ C allele was a risk factor for it. Metabolic traits were associated with both PPAR polymorphisms.

GSTT1 and GSTM1 null variants in Mestizo and Amerindian populations from northwestern Mexico and a literature review

Abstract The GSTT1 and GSTM1 genes are key molecules in cellular detoxification. Null variants in these genes are associated with increase susceptibility to developing different types of cancers. The aim of this study was to determine the prevalence of GSTT1 and GSTM1 null genotypes in Mestizo and Amerindian individuals from the Northwestern region of Mexico, and to compare them with those reported worldwide. GSTT1 and GSTM1 null variants were genotyped by multiplex PCR in 211 Mestizos and 211 Amerindian individuals. Studies reporting on frequency of GSTT1 and GSTM1 null variants worldwide were identified by a PubMed search and their geographic distribution were analyzed. We found no significant differences in the frequency of the null genotype for GSTT1 and GSM1 genes between Mestizo and Amerindian individuals. Worldwide frequencies of the GSTT1 and GSTM1 null genotypes ranges from 0.10 to 0.51, and from 0.11 to 0.67, respectively. Interestingly, in most countries the frequency of the GSTT1 null genotype is common or frequent (76%), whereas the frequency of the GSMT1 null genotype is very frequent or extremely frequent (86%). Thus, ethnic-dependent differences in the prevalence of GSTT1 and GSTM1 null variants may influence the effect of environmental carcinogens in cancer risk.

GSTT1 and GSTM1 null variants in Mestizo and Amerindian populations from northwestern Mexico and a literature review.

The GSTT1 and GSTM1 genes are key molecules in cellular detoxification. Null variants in these genes are associated with increase susceptibility to developing different types of cancers. The aim of this study was to determine the prevalence of GSTT1 and GSTM1 null genotypes in Mestizo and Amerindian individuals from the Northwestern region of Mexico, and to compare them with those reported worldwide. GSTT1 and GSTM1 null variants were genotyped by multiplex PCR in 211 Mestizos and 211 Amerindian individuals. Studies reporting on frequency of GSTT1 and GSTM1 null variants worldwide were identified by a PubMed search and their geographic distribution were analyzed. We found no significant differences in the frequency of the null genotype for GSTT1 and GSM1 genes between Mestizo and Amerindian individuals. Worldwide frequencies of the GSTT1 and GSTM1 null genotypes ranges from 0.10 to 0.51, and from 0.11 to 0.67, respectively. Interestingly, in most countries the frequency of the GSTT1 null genotype is common or frequent (76%), whereas the frequency of the GSMT1 null genotype is very frequent or extremely frequent (86%). Thus, ethnic-dependent differences in the prevalence of GSTT1 and GSTM1 null variants may influence the effect of environmental carcinogens in cancer risk.

Biological aspects of crosses between Triatoma recurva (Stål), 1868 (Hemiptera: Reduviidae: Triatominae) and other members of the Phyllosoma complex.

The degree of reproductive isolation between Triatoma recurva (Stål) (Hemiptera: Reduviidae: Triatominae) and the six species of the genus Meccus plus T. mexicana (Herrich-Schaeffer) (Hemiptera: Reduviidae) was examined. Fertility and the segregation of morphological characteristics were examined in two generations of hybrids from crosses between these species. The percentage of couples with offspring (fertile) was low in the vast majority of sets of crosses, with the exception of that between T. recurva female and M. phyllosomus male. In all studied sets of crosses, no first- (F1) or second- (F2) generation individuals were morphologically similar to T. recurva but instead shared the morphology of the other parental species. A similar phenomenon was observed in the three successful sets of backcrosses. These results indicated that different recorded levels of reproductive fitness among T. recurva and the species of Meccus involved in this study, plus T. mexicana, are present and that they were apparently influenced by differing mechanisms of isolation. The presence of some degree of reproductive compatibility between studied triatomines of distinct genera (Meccus spp. and Triatoma spp.) reinforces the need for generic revision of the tribe Triatomini.

Comparative bionomics of four populations of Meccus longipennis (Hemiptera: Reduviidae: Triatominae) under laboratory conditions.

The values of biological parameters related to the life cycles of four populations of Meccus longipennis (Reduviidae: Triatominae) were evaluated. Cohorts of each of the four studied populations from different geographical areas of Mexico were maintained under similar laboratory conditions and then compared. The population from El Saucito de Araujo was different from the other three studied populations, which could help explain the secondary importance of M. longipennis in the state of Chihuahua. This paper also supports the proposition that biological traits are important criteria for determining relationships between populations.

The biology of three Mexican-American species of Triatominae (Hemiptera: Reduviidae): Triatoma recurva, Triatoma protracta and Triatoma rubida.

The values of biological parameters related to hatching, lifespan, the number of blood meals between moults, mortality, time lapse before the beginning of feeding, feeding time and defecation delay for each instar of three Mexican-American species of Triatominae, Triatoma recurva, Triatoma protracta (former subspecies protracta) and Triatoma rubida (former subspecies uhleri), were evaluated and compared. No significant (p > 0.05) differences were recorded among the three species with respect to the average time required to hatch. This time was approximately 19 days. The average egg-to-adult development time was significantly (p < 0.05) shorter for T. rubida. The number of blood meals at each nymphal instar varied from one-five for each species. The mortality rates were higher for the first-instar nymphs of the three species studied. The mean time lapse before the beginning of feeding was between 0.3-3 min for most nymphs of all instars of each species studied. The mean feeding time was the longest for T. recurva, followed by T. protracta. The defecation delay was less than 10 min for T. recurva and T. rubida. Given these results, only T. rubida should be considered an important potential vector of Trypanosoma cruzi transmission to humans in areas of Mexico where these species exist, whereas T. recurva and T. protracta would be of secondary importance.

Infección natural por Trypanosoma cruzi en triatominos del Centro y Norte de México / Natural infection by Trypanosoma cruzi in triatomines of central and northern Mexico

En este estudio se reportan las colectas de triatominos realizadas en los estados mexicanos de Chihuahua y Aguascalientes, de los cuales se carecía de datos recientes sobre presencia e infección por Trypanosoma cruzi en triatominos vectores de la enfermedad de Chagas. En Chihuahua se colectaron exclusivamente ejemplares adultos de Triatoma recurva y de Meccus phyllosomus longipennis, con porcentajes de infección por Trypanosoma cruzi de 5,17% y 12,5%, respectivamente. En Aguascalientes se colectaron ejemplares adultos y ninfas sólo de M. p. longipennis, con un porcentaje de infección por T. cruzi de 96,7%. Los resultados indican nula colonización de la vivienda por triatominos en el área de estudio en Chihuahua, así como bajo riesgo de infección por T. cruzi. En contraste, en el área de estudio en Aguascalientes se prevé riesgo alto de infección por T. cruzi a la población. Se requiere de investigaciones entomológicas adicionales en las áreas de estudio para clarificar el riesgo de transmisión vectorial de T. cruzi a los humanos y reservorios animales.

On this study are reported some collections of triatomines from the Mexican states of Chihuahua and Aguascalientes, where recent data about vector infection by Trypanosoma cruzi was not available. In the state of Chihuahua only adult specimens of Triatoma recurva and of Meccus phyllosomus longipennis were collected. Percentages of infection by T. cruzi were respectively 5.17% and 12.5%. In the state of Aguascalientes adult as well nymph specimens of M. p. longipennis were collected. Percentage of infection by T. cruzi reached 96.7%. Our results show a null colonization of human dwellings by triatomines in the study area of the state of Chihuahua, as well as low risk of infection by T. cruzi for the inhabitants of that area. On the other hand, in the study area in the state of Aguascalientes, the risk of infection by T. cruzi was high for inhabitants of the area. Complementary entomological studies are necessary to establish the proper risk of infection by vectorial transmission of T. cruzi to human and animal reservoir host in the two studied areas.

Immunogenicity and biophysical properties of a Nocardia brasiliensis protease involved in pathogenesis of mycetoma.

We isolated and purified to homogeneity a caseinolytic protease from a Nocardia brasiliensis cell extract. Preparative polyacrylamide gel electrophoresis and electroelution were employed for purification. This purified protease was injected in BALB/c mice and induced IgM and IgG anti-protease antibodies. Active immunization of mice with this protease prevented mycetoma development in experimentally infected animals. Passive immunization with hyperimmune sera containing a high anti-protease antibody titer conferred partial but transient protection when collected 30 days after donor's immunization. The protective effect of hyperimmune sera was lost when obtained from donors after 60 days from their immunization despite its higher anti-protease antibody concentration. Cytokines are good candidates to explain these findings.