Papers by Guadalupe Hernández-pacheco
Arch. cardiol. …, 2008
Base de dados : LILACS. Pesquisa : 567655 [Identificador único]. Referências encontradas : 1 [ref... more Base de dados : LILACS. Pesquisa : 567655 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. Texto completo. experimental, Documentos relacionados. Id: 567655 ...
Human Biology
Apolipoprotein E (APOE) genotypes were determined in 75 Mazatecan Indians and 83 Mexican mestizos... more Apolipoprotein E (APOE) genotypes were determined in 75 Mazatecan Indians and 83 Mexican mestizos. APOE allele and genotype frequencies in Mazatecans and mestizos were similar, with high frequencies of the APOE*3 allele (0.900 and 0.915, respectively) and the E3/3 genotype (0.813 and 0.831, respectively) and an absence in both samples of the APOE*2 allele. Our data are similar to those previously described for Mexican-American and Mayan populations, which show the highest frequency worldwide of the APOE*3 allele and the E3/3 genotype. Mazatecans and mestizos also show a decreased frequency of the APOE*4 allele when compared to other Amerindian groups. The absence of the APOE*2 allele has also been reported in other Amerindian groups such as Mayans and Cayapa, whereas in Caucasians the average frequency of this allele is about 8%. Our data are in agreement with previous reports showing absence of the APOE*2 allele in Native American groups. These findings suggest that the APOE*2 alle...
Human biology, 2005
Matrix gamma-carboxyglutamic acid protein (MGP) genotypes (G-7A and T-138C) were determined in 26... more Matrix gamma-carboxyglutamic acid protein (MGP) genotypes (G-7A and T-138C) were determined in 266 individuals from three Mexican populations. Mexicans showed increased frequencies of the G-7A G allele and the G7-A GG genotype compared to Europeans. For the T-138C genotype, we found differences among the Mexicans. This study could help to define the significance of MGP polymorphisms as genetic markers in Amerindian populations.
Aims To investigate the association of the Gly389 allele with positive head-up tilt test (HUT) in... more Aims To investigate the association of the Gly389 allele with positive head-up tilt test (HUT) in a Mexican Mestizo population. Methods and results HUT results were compared between carriers (one or two copies of the Gly389 allele) and non-carriers (Arg389Arg genotype) of the Gly389 allele of the b 1 AR gene in 50 patients with unexplained syncope. Thirty-three patients (66%) had a positive HUT. Patients with a positive HUT had a higher Gly389 allele frequency compared with those with a negative test (30.3 vs. 3%; OR 13; pC ¼ 0.012). Moreover, when comparing positive HUT in passive drug-free phase, positive HUT in pharmacological (nitrate) phase, and negative (both phases), a decreasing gradient in the frequencies of the Gly389 allele was found among the three groups: 45.4, 22.7, and 3%, respectively. Conclusion An association of positive tilt table testing to a single nucleotide polymorphism with a Gly to Arg switch at position 389 of the b 1 AR was found. This polymorphism may contribute to susceptibility to faint during orthostatic challenge.
Molecular Immunology, 2006
The HLA allele frequency distribution of the Mexican Teenek Indians has been studied and compared... more The HLA allele frequency distribution of the Mexican Teenek Indians has been studied and compared with those of other First American Natives and worldwide populations (a total of 15694 chromosomes from 73 different populations were analyzed). This study corroborate the restricted HLA polymorphism in the Amerindian populations and demonstrate how the Amerindians show a relatively homogeneity as opposed to other First Native American groups. Finally, the present data support previous ones that state the lack of complete correlation between language and genetics in micro-environmental studies; Teenek Mayan language does not correspond with a close Mayan (Guatemala) relatedness.
Journal of Autoimmunity, 2005
The aim of this study was to determine the frequency and potential relevance of the promoter poly... more The aim of this study was to determine the frequency and potential relevance of the promoter polymorphisms of the tumor necrosis factor-alpha (TNF-a) in the severity of rheumatoid arthritis (RA) in Mexicans. HLA-DR and polymorphisms at positions ÿ238 and ÿ308 of TNF-a gene were determined in 137 Mexican RA patients (44 with severe and 93 with non-severe RA) as well as in 169 healthy controls (99 were typed for HLA-DR). We observed an increased frequency of HLA-DR4 in severe RA compared to healthy controls (pC Z 0.02, OR Z 2.33). TNF polymorphism analysis showed a significant increased frequency of TNF ÿ238 GG genotype in the whole group of RA patients when compared to healthy controls (pC Z 0.007, OR Z 4.71). When the analyses were carried out separately in severe and non-severe RA patients, the increased frequency of ÿ238 GG genotype only was observed in patients with non-severe forms of the disease. Analysis of ÿ308 polymorphism showed increased frequency of ÿ308 T2 (A) allele in severe RA when compared to non-severe disease (pC Z 0.011, OR Z 3.29) and to healthy controls (pC Z 0.002, OR Z 3.97). The data demonstrate that ÿ308 T2 (A) allele is associated with susceptibility to develop severe RA in Mexicans. This association could be independent from HLA-DR alleles and might be used as a prognostic marker for severe RA.
International Journal of Cardiology, 2003
Rheumatic heart disease (RHD) is an autoimmune sequel of group A streptococcal infection that has... more Rheumatic heart disease (RHD) is an autoimmune sequel of group A streptococcal infection that has been associated with the presence of some major histocompatibility complex (MHC) genes. Thus, the aim of the present study was to investigate the role of class II alleles in the genetic susceptibility to RHD in Mexican patients and establish the relationship of these alleles with the pattern of valve damage. HLA-DR, -DQA1 and -DQB1 allele frequencies were determined by PCR-SSO reverse dot blot and PCR-SSP in 98 Mexican Mestizo patients with RHD and 99 healthy controls. Patients were divided into mitral valve damage (n=46), multivalvular lesion (n=49) and aortic damage (n=3). RHD patients presented an HLA-DR16 increased frequency (pC=0.009, OR=3.9) and a decreased HLA-DR11 frequency (pC=0.018) when compared to healthy controls. HLA-DR16 subtyping showed that DRB1*1602 was the DR16 allele increased in patients (pC=0.007, OR=5.3). Haplotype analysis showed increased frequency of DR16-DQA1*0501-DQB1*0301 in RHD patients when compared to healthy controls (pC=0.011). HLA-DR16 frequency remained significantly increased on patients with multivalvular lesion (pC=0.004, OR=4.8). Our data suggest an important participation of Amerindian autochthonous HLA-DR16 (DRB1*1602) allele and DR16-DQA1*0501-DQB1*0301 haplotype as markers for RHD genetic susceptibility in the Mexican Mestizo population. HLA-DR16 allele could also play an important role in determining the pattern of valve damage on these patients.
International Journal of Cardiology, 2000
Takayasu arteritis (TA) is characterized by a 'pulseless' condition and occurs fr... more Takayasu arteritis (TA) is characterized by a 'pulseless' condition and occurs frequently in young females from Asian and South American countries. It has been associated with Mayor Histocompatibility Complex (MHC) genes in different populations. Recent data indicate direct participation of HLA-B alleles in the susceptibility to the disease. This fact was explored in an associative study with TA to establish if some region in the exon 2, intron 2 or in the exon 3 of HLA-B alleles is common in the alleles associated with TA and at the same time to know if a specific sequence or an epitope, more than an allele, would be responsible for the susceptibility to this vasculitis. We studied HLA-B alleles of 12 Mexican patients with TA using PCR-SSP and sequencing. The analysis by PCR-SSP in 12 patients showed that five of them showed the B*15 allele, three the B*40 allele and two the B*39 allele, the remaining two presented the B*44 allele. Sequence analysis enabled us to define that the B*39 subtypes are B*3908; B*15 subtypes are B*1510, B*1515, B*1522 and B*1531; and the B*40 subtypes are B*4005 and B*4008. An individual with B*51 (B*5107) and another with B*52 (B*5201) alleles were also identified. The sequences of the intron 2 seem be heterogeneous. Analysis at the 63 and 67 positions of HLA-B alleles showed that 9 of them have similarity in some of these positions with the residues detected in the B*5201 and B*3902 alleles associated with TA in Asian populations. The results indicate that there is heterogeneity in the alleles associated with TA in Mexicans but, in spite of that heterogeneity, the alleles associates can be separated into three groups: B*39, B*15 and B*40, whose subtypes are rare and apparently of recent generation in Mexico, probably by recombination events at intron 2 level. The sequences analysis also shows that most of the alleles detected in the Mexican patients share two epitopes described in the susceptibility alleles in Asian populations, suggesting that these epitopes could be responsible for the susceptibility to develop the disease in spite of the allele in which are found.
Immunology Letters, 2005
Takayasu&... more Takayasu's Arteritis (TA) has been associated with the Major Histocompatibility Complex (MHC) genes; nevertheless, results in several populations have been heterogeneous. Studies both in Mexican and Asian populations suggest that residues at positions 63 (glutamic acid) and 67 (serine) of the HLA-B molecule could be the genetic markers for TA. In the present work, we analyzed the sequence of HLA-B alleles in 26 TA patients and 62 healthy controls. HLA-B subtyping analysis showed that all B52 alleles were B*5201, whereas only one HLA-B39 allele was B*3902. Sequencing of HLA-B alleles showed that 19 out of 26 patients studied (73.0%) presented at least an allele with glutamic acid at position 63 and serine at position 67. This condition was observed in only 21.0% of the healthy controls (pC = 0.00001, OR = 10.23). Out of the seven remaining patients, one presented glutamic acid at position 63 and four showed serine at position 67. Two patients (2/26 = 7.7%) and 24 healthy controls (24/62 = 38.7%) did not show similarity at the mentioned positions (pC = 0.016, OR = 0.13). These data corroborate the participation of positions 63 and 67 in the genetic susceptibility to TA and explain the high heterogeneity of alleles associated with the disease in several populations.
Human Immunology, 2002
The human leukocyte antigen DRB1 locus (HLA-DRB1) was typed in genomic DNA extracted from whole b... more The human leukocyte antigen DRB1 locus (HLA-DRB1) was typed in genomic DNA extracted from whole blood samples of 34 Mexican dengue hemorrhagic fever (DHF) patients and 47 dengue fever (DF) patients, by polymerase chain reaction-sequence-specific oligonucleotide reverse dot blot. HLA-DRB1*04 was negatively associated with risk of DHF (OR 0.31, 95% CI 0.11-0.85). HLA-DR4 homozygous individuals were 11.6 times less likely to develop DHF in comparison to DR4 negative persons (OR 0.08, 95% CI 0.01-0.75). After adjusting for gender and infection type by logistic regression, DR4 positive individuals were 3.6 times less likely to develop DHF than DR4 negative persons (OR 0.28, 95% CI 0.12-0.66). A secondary dengue virus infection was also positively linked with DHF risk (OR 2.89, 95% CI 0.92-9.07). This data suggests that genes of the major histocompatibility complex play a major role in the susceptibility and/or resistance to develop DHF. In Mexicans, HLA-DR4 may be a genetic factor that is protective against DHF. Because HLA-DR4 has been positively selected in Latin American populations, these results may apply also to other similar ethnic groups, particularly those with high percentages of admixture with indigenous Amerindian genes.
Human Immunology, 2004
The risk to develop rheumatoid arthritis (RA) has been associated with the presence of HLA-DRB1 a... more The risk to develop rheumatoid arthritis (RA) has been associated with the presence of HLA-DRB1 alleles encoding the "shared epitope" (SE). Additionally, HLA-DRB1 alleles encoding an aspartic acid at position 70 (D 70ϩ ) have been associated with protection against the development of RA. In this study we tested the association between either SE or D 70ϩ and rheumatoid arthritis in Mexican Mestizos. We included 84 unrelated Mexican Mestizos patients with RA and 99 unrelated healthy controls. The HLA-typing was performed by PCR-SSO and PCR-SSP. We used the chi-squared test to detect differences in proportions of individuals carrying at least one SE or D 70ϩ between patients and controls. We found that the proportion of individuals carrying at least one HLA-DRB1 allele encoding the SE was significantly increased in RA cases as compared to controls (p c ϭ 0.0004, OR ϭ 4.1, 95% CI ϭ 2.2-7.7). The most frequently occurring allele was HLA-DRB1*0404 (0.161 vs 0.045). Moreover, we observed a significantly increased proportion of HLA-DRB1 SEϩ cases with RF titers above the median (p ϭ 0.005). Conversely, the proportion of individuals carrying at least one HLA-DRB1 allele encoding the D 70ϩ was significantly decreased (p c ϭ 0.004, OR ϭ 0.4, 95% CI 0.2-0.7) among RA patients compared with controls. In conclusion, the SE is associated with RA in Mexican Mestizos as well as with the highest titers of RF. Human Immunology 65, 262Ϫ269 (2004).
Human Immunology, 2001
DRB1*15/16 nucleotide polymorphism was analyzed in 68 DR2 positive individuals (18 Mexican Mestiz... more DRB1*15/16 nucleotide polymorphism was analyzed in 68 DR2 positive individuals (18 Mexican Mestizos, 30 Mazatecans and 20 Nahuas), carrying a total of 75 DR2 haplotypes. HLA-DR2 was one of the most frequent specificities detected in Mazatecans and Nahuas with gene frequency (gf) of 0.232 and 0.141, respectively. In these populations DRB1*16 was the most frequent DR2 split (gf ϭ 0.183 in Mazatecans and gf ϭ 0.135 in Nahuas), whereas in Mexican Mestizos the most frequent was DRB1*15 (gf ϭ 0.065). Four DRB1-DQB1 combinations in Mexican Mestizos, two in Mazatecans and one in Nahuas were in linkage disequilibrium. In spite of the restricted polymorphism, there were differences on DRB1
Human Biology, 2005
1. Hum Biol. 2005 Jun;77(3):385-91. Matrix gamma-carboxyglutamic acid protein (MGP) G-7A and T-13... more 1. Hum Biol. 2005 Jun;77(3):385-91. Matrix gamma-carboxyglutamic acid protein (MGP) G-7A and T-138C gene polymorphisms in Indian (Mayo and Teenek) and Mestizo populations from Mexico. Hernández-Pacheco G, Murguía ...
Human biology, 2003
The angiotensin-converting enzyme gene (ACE) insertion/deletion polymorphism was determined in 21... more The angiotensin-converting enzyme gene (ACE) insertion/deletion polymorphism was determined in 211 Mexican healthy individuals belonging to different Mexican ethnic groups (98 Mestizos, 64 Teenek, and 49 Nahuas). ACE polymorphism differed among Mexicans with a high frequency of the D allele and the D/D genotype in Mexican Mestizos. The D/D genotype was absent in Teenek and present in only one Nahua individual (2.0%). When comparisons were made, we observed that Caucasian, African, and Asian populations presented the highest frequencies of the D allele, whereas Amerindian (Teenek and Pima) and Australian Aboriginals showed the highest frequencies of the I allele. The distribution of I/D genotype was heterogeneous in all populations: Australian Aboriginals presented the lowest frequency (4.9%), whereas Nahuas presented the highest (73.4%). The present study shows the frequencies of a polymorphism not analyzed previously in Mexican populations and establishes that this polymorphism dis...
Genes and Immunity, 2000
Major histocompatibility complex (MHC) alleles have been recognized as genetic factors for develo... more Major histocompatibility complex (MHC) alleles have been recognized as genetic factors for developing systemic lupus erythematosus (SLE). In the present study we analyzed whether a heat-shock protein gene (HSP70-2) is involved in determining susceptibility to develop SLE in a Mexican Mestizo population. A HSP70-2 Pst I polymorphism was detected by a restriction fragment length polymorphism analysis of polymerase chain reaction (PCR-RFLP) in 107 SLE patients and 158 healthy controls. No statistically significant differences were observed in the HSP70-2 allele distribution between patients and healthy controls. HLA-DR analysis showed an increased frequency of HLA-DR3 allele in the patients group (P Ͻ 0.05, OR = 2.26, EF = 6.0%). On the other hand, when we analyzed HSP70-2 polymorphism in relation to HLA-DR3 allele, we could only detect an increased frequency of AB genotype in the DR3 negative patients (pC Ͻ 0.05, RR = 2.6, EF = 11.3%). Linkage disequilibrium was observed for three haplotypes: HLA-DR3-HSP70-2A (D = 0.03, D' = 0.67, P Ͻ 0.01); HLA-DR1-HSP70-2A (D = 0.03, D' = 0.86, P Ͻ 0.01) and HLA-DR8-HSP70-2B (D = 0.02, D' = 0.46, P = 0.02). Our data indicate that HSP70-2 gene polymorphism as opposed to the other ethnic groups does not appear to be relevant in SLE susceptibility in Mexican patients and that the distribution of the different alleles depend on the frequency of HLA alleles associated with them. Genes and Immunity (2000) 1, 367-370.
Genes and Immunity, 1999
The major histocompatibility complex (MHC) genes are highly polymorphic and therefore have been u... more The major histocompatibility complex (MHC) genes are highly polymorphic and therefore have been useful in population genetics and disease association studies. We analyzed restriction fragment length polymorphism of HSP70-2 alleles in healthy unrelated Mestizo, Mazatecan and Nahua populations. Both Indian groups, Mazatecans and Nahuas, were in Hardy-Weinberg equilibrium, while Mestizos were in disequilibrium ( 2 = 0.399; P Ͻ 0.05). The Mazatecan Indians presented a high frequency of BB homozygosity (17.35%) compared to Mestizos (5%) (P = 0.01). Mexican ethnic groups present differences in distribution of BB genotype. The low frequency of BB genotype in Mestizos may be the result of a negative selection process.
Genes and Immunity, 2001
The major histocompatibility (MHC) genes including TNF-␣, HSP70 and HLA genes have been associate... more The major histocompatibility (MHC) genes including TNF-␣, HSP70 and HLA genes have been associated with systemic lupus erythematosus (SLE) in several populations. In this study we analyze the polymorphism of TNF-␣ promoter in 51 Mexican Mestizo SLE patients and 55 ethnically-matched healthy controls by polymerase chain reaction methods. No statistically significant differences were observed in the TNF −308 allele and genotype distribution between patients and healthy controls. However, we found a significant increase in the TNF G/A −238 genotype and in the TNFA −238 allele frequencies in the SLE group when compared with healthy controls (Pc = 0.03, OR = 4.77 and Pc = 0.02, OR = 3.62, respectively). DRB1 analysis showed a similar distribution in patients and controls. Linkage disequilibrium was observed for five haplotypes: DRB1*1401-TNFA−238 (D = 0.84; DЈ = 1.0; P = 0.015); DRB1*0301-TNFA−238 (D = 1.38; DЈ = 0.41; P = 0.042); DRB1*1106-TNF2−308 (D = 0.9; DЈ = 1.0; P = 0.0006); DRB1*1104-TNF2−308 (D = 0.83; DЈ = 0.45; P = 0.02) and DRB1*1406-TNF2−308 (D = 0.83; DЈ = 0.45; P = 0.02). Our data suggest that the association between the TNF-␣ −238 polymorphism and SLE could play a major role in disease susceptibility. Genes and Immunity (2001) 2, 363-366.
Uploads
Papers by Guadalupe Hernández-pacheco