Ancient genomes reveal insights into ritual life at Chichén Itzá.

The ancient city of Chichén Itzá in Yucatán, Mexico, was one of the largest and most influential Maya settlements during the Late and Terminal Classic periods (AD 600-1000) and it remains one of the most intensively studied archaeological sites in Mesoamerica1-4. However, many questions about the social and cultural use of its ceremonial spaces, as well as its population's genetic ties to other Mesoamerican groups, remain unanswered2. Here we present genome-wide data obtained from 64 subadult individuals dating to around AD 500-900 that were found in a subterranean mass burial near the Sacred Cenote (sinkhole) in the ceremonial centre of Chichén Itzá. Genetic analyses showed that all analysed individuals were male and several individuals were closely related, including two pairs of monozygotic twins. Twins feature prominently in Mayan and broader Mesoamerican mythology, where they embody qualities of duality among deities and heroes5, but until now they had not been identified in ancient Mayan mortuary contexts. Genetic comparison to present-day people in the region shows genetic continuity with the ancient inhabitants of Chichén Itzá, except at certain genetic loci related to human immunity, including the human leukocyte antigen complex, suggesting signals of adaptation due to infectious diseases introduced to the region during the colonial period.

Secular trends in the anthropometric characteristics of children in a rural community in Yucatan, Mexico.

OBJECTIVE: To analyze changes in height, weight, and body mass index (BMI = kg/m2 ) from 1986 to 2022 in 3-11 year old children from Dzeal, a rural Maya community in Yucatan, Mexico. MATERIALS AND METHODS: From October-2022 to February-2023 (third-wave survey), we obtained anthropometric measurements of children (n = 80) and family socioeconomic data and compared them with data obtained in 1986 (n = 38) and 2000 (n = 76). Comparisons of anthropometric parameters by sex between years of measurement were performed graphically and through one-way ANOVA, splitting children into two age groups: 3-7 and 8-11. Bonferroni adjustments for multiple comparisons were used when ANOVAs were statistically significant (p < .05). RESULTS: In girls, significant increases in height and weight between surveys were found in 3-7 and 8-11 age groups; in boys, significant increases were only found in the 8-11 age group. Regarding BMI, there were increases in 2022 compared with 1986/2000 in both sexes from 8 years onwards. Differences indicate increases of 3.9 and 4.4 cm per decade in girls aged 3-7 and 8-11, respectively, and increases in weight of 1.1 and 3.3 kg per decade, respectively. Increases in boys 8-11 years were 2.3 cm and 2.4 kg per decade. CONCLUSION: Significant increases in growth parameters were observed in specific-age children in the community studied in the context of changes in livelihoods and improvements in household material conditions.

Birthweight and its association with cardiometabolic risk parameters in rural Maya children from Yucatan, Mexico.

BACKGROUND: Knowledge about the influence of early developmental factors on cardiometabolic health in the Maya is limited. AIM: To analyse the relationship between birthweight (BW) and cardiometabolic parameters in a sample of rural Maya children from Yucatan, Mexico. SUBJECTS AND METHODS: We took anthropometric measurements and obtained data on BW and fasting blood samples in a sample of 75 children aged 5-14 years. Dependent variables were: fat mass index (FMI), body mass index (BMI), glucose (G), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), LDL/HDL and TC/HDL ratios and metabolic index (TGxG/HDL2). Outcomes were transformed to y = 100 log(e)x and the resulting estimates are interpreted as symmetrical percentage differences. The main independent variable was BW z-score. Multiple linear regression analyses were used to assess the relationship between BW and outcomes. RESULTS: An increase of one standard deviation in BW predicted 6.6% (95% CI [-11.6, -1.6]) decrease in HDL and 11% (95% CI [3.7, 18.4]), 7.8% (95% CI [2.3, 13.2]) and 19.6% (95% CI [3.1, 36]) increases in LDL/HDL, TC/HDL and metabolic index, respectively. CONCLUSION: Higher birthweights were associated with adverse levels of biochemical parameters in this sample of rural Maya children.

In Vitro Activation of Macrophages by an MHC Class II-restricted Trichomonas Vaginalis TvZIP8-derived Synthetic Peptide.

BACKGROUND: Macrophages play an important role in the inflammatory response towards pathogens and their effector functions depend on the mode of activation which is mediated by recognition of pathogen-associated molecular patterns, as peptides. Trichomonas vaginalis provokes an inflammatory response in the host in which macrophages are the first line of defense. This study aimed to analyze the effect of a specific peptide derived from the transporter TvZIP8 of T. vaginalis on the activation of macrophages. METHODS: An in silico approach based on computational prediction of epitopes was applied to detect potential murine MHC class II-restricted peptides from TvZIP8 that can activate macrophages and the immunomodulatory activity was evaluated by in vitro stimulation of murine macrophages. RESULTS: Based on binding scores, one peptide denominated TvZIP8-pep was selected for further analysis. In vitro stimulation with synthetic TvZIP8-pep triggered on murine macrophages the NO and H2O2 production and an overexpression of iNOS and NOX-2 genes. Also, a significant increase of pro-inflammatory cytokines: IL-1ß, IL-6, and TNF-α, as well as, overexpression of the TLR4, MyD88, and NF-κB genes and NF-κB activation were observed on macrophages after stimulation with TvZIP8-pep in vitro. Moreover, higher levels of IFN-γ were detected in co-cultures using CD4 + T cells with TvZIP8-pep-stimulated macrophages. CONCLUSION: These results support the potential of TvZIP8 as a promising antigen to stimulates a specific macrophage response against T. vaginalis, but further analyses are required to evaluate their possible potential as a novel antigen for immunodiagnosis and/or vaccine against trichomoniasis.

Volviéndonos mejores: necesidad de acción inmediata ante el reto de la obesidad. Una postura de profesionales de la salud.

La creciente epidemia de obesidad ha sido uno de los retos más importantes de salud pública en México durante los últimos años. Con apoyo de la Federación Mundial de Obesidad, en 2021 formamos un grupo de profesionales para identificar y resumir las acciones prioritarias en las que puede enfocarse nuestro país para hacer frente a esta epidemia. Al proceso de desarrollo y discusión de este grupo se sumaron más de 1 000 profesionales de la salud para retomar recomendaciones de documentos y guías de alto nivel previamente publicados. En conmemoración del Día Mundial de la Obesidad, en este 2022 se presenta esta postura como insumo para el desarrollo de acciones en el ámbito profesional y de los diferentes sectores, en la que se incluyen 10 recomendaciones de acción, desde la perspectiva poblacional hasta la atención individualizada, y se enfatiza en la importancia de la participación social, de las intervenciones integrales con visión centrada en la persona y de la sostenibilidad planetaria, además de mejorar la educación y las campañas de difusión, propiciar un ambiente promotor de entornos activos y blindar de conflictos de interés los esfuerzos de prevención y control. La postura hace un llamado para abordar la obesidad de manera seria, con base en la evidencia científica, oportuna e integral, con enfoque de curso de vida, de forma ética y sensible, y sin perpetuar las barreras del estigma de peso en la sociedad.

High expression levels of circulating microRNA-122 and microRNA-222 are associated with obesity in children with Mayan ethnicity.

OBJECTIVES: High expression levels (HELs) of microRNA-122 (miR-122) or microRNA-222 (miR-222) have been associated with insulin resistance (IR), which leads to the development of obesity. The association between HELs of circulating miR-122 and miR-222 and the risk of obesity was evaluated in Mexican school-aged children, where childhood obesity is the primary cause of morbidity. METHODS: Anthropometric data, biochemical parameters, and caloric intake were obtained in 50 children with obesity and 49 children with normal weight. The expression of circulating miR-122 and miR-222 was measured by quantitative real-time polymerase chain reaction amplification. Data were analyzed using Student t test, Pearson correlation coefficient, associations with chi-square, and multiple linear and logistic regressions with SPSS software v.23. RESULTS: The mean relative expression for miR-122 and miR-222 was 0.33 and 5.65, respectively, for children with obesity and 0.22 and 3.16, respectively, for children with normal weight. The expression of miR-122 and miR-222 was 1.47 and 1.78-fold higher, respectively, in children with obesity (P = 0.001 and P = 0.025). HELs of both miR-122 and miR-222 were associated with body mass index (BMI), waist to height ratio (WHR), fat percentage, serum high-density lipid levels, triglycerides (TGs), and metabolic index (MI) (P < .001). CONCLUSIONS: The HELs of circulating miR-122 conferred a 3.85-fold increase in the risk for obesity, whereas the HELs of both miR-122 and miR-222 conferred a 3.11-fold increase in the risk for obesity, which were also associated with higher anthropometric or biochemical parameters, such as BMI, WHR, fat percentage, serum high-density lipid levels, TGs, and MI, in Mayan children.

Anti-inflammatory effects of Chrysophyllum cainito fruit extract in lipopolysaccharide-stimulated mouse peritoneal macrophages.

The present paper sought to investigate the in vitro and in vivo anti-inflammatory effects of the methanolic extract (ME), hexane-ethyl acetate fraction E (FE) found in Chrysophyllum cainito fruits (CCF), as well the lupeol acetate (LA) obtained from FE on lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages. The macrophages were treated with ME, FE or LA at various concentrations and the viability of cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. Production of pro-inflammatory (IL-1ß, IL-6, and TNF-α) and anti-inflammatory (IL-10) cytokines, as well as the nitric oxide (NO) and hydrogen peroxide (H2O2) levels was determined using macrophages treated with ME, FE or LA at various concentrations and stimulated with LPS as an in vitro model. Afterwards, we evaluated the anti-inflammatory effects in vivo using the TPA-induced ear edema and carrageenan-induced paw edema tests in mice and production of inflammatory mediators was estimated in serum samples. The results showed that the ME, FE and LA from fruits, FE and LA were able to trigger an inhibition in NO and H2O2 levels, as well as IL-1ß, IL-6, and TNF-α released by macrophages in a concentration-dependent manner. LA from C. cainito fruits was found to significantly attenuate carrageenan-induced paw edema and TPA-induced ear edema. Therefore, the results suggest ME, FE and LA isolated from C. cainito fruits have anti-inflammatory effects on macrophages without affecting cell viability.

In silico analysis of putative metal response elements (MREs) in the zinc-responsive genes from Trichomonas vaginalis and the identification of novel palindromic MRE-like motif.

Zinc is an essential micronutrient that plays an important role as a co-factor to several proteins, including zinc-responsive transcription factors. Trichomonas vaginalis is able to survive in the presence of high zinc concentrations in the male urogenital tract. Several genes in T. vaginalis have been shown to respond to changes in zinc concentrations, however, the zinc-dependent mechanism remains undetermined. Recently, we identified in T. vaginalis the zinc finger protein, TvZNF1, which is an ortholog of the mammal metal transcription factor (MTF1). We searched for several of the zinc-responsive genes in T. vaginalis to determine whether if they contain metal response elements (MRE), cis-acting DNA elements that specifically bind MTF1. Six highly conserved over-represented sequence motifs (TvMREs), which share similarity with other eukaryotic MREs, were identified in the zinc-responsive genes in T. vaginalis. We also demonstrated that some of the TvMREs assemble as divalent complexes either as two closely spaced TvMREs or as two overlapping TvMREs forming a palindromic-like sequence: TGCC(N3)GGCA. Electrophoretic mobility shift assays were used to detect the zinc-dependent binding of TvZNF1 and nuclear proteins from T. vaginalis to this specific palindromic motif. Our results support a novel mechanism used by T. vaginalis for the transcriptional regulation of associated zinc-responsive genes through a MTF1/MRE-like system.

Anti-inflammatory and antinociceptive effects of an ethanol extract from Senna septemtrionalis.

Senna septemtrionalis (Viv.) H.S. Irwin & Barneby (Fabaceae) is a medicinal plant used as a folk remedy for inflammation and pain. The objective of this study was to evaluate the anti-inflammatory and antinociceptive actions of an ethanol extract of Senna septemtrionalis aerial parts (SSE). The in vitro anti-inflammatory effects of SSE were assessed using LPS-stimulated macrophages and the subsequent quantification of the levels of cytokines (IL-6, IL-1ß, and TNF-α) with ELISA kits, nitric oxide (NO), and hydrogen peroxide (H2O2). The in vivo anti-inflammatory actions of SSE were evaluated with the TPA-induced ear oedema test and the carrageenan-induced paw oedema test. The antinociceptive actions of SSE (10-200 mg/kg p.o.) were assessed using three models: two chemical assays (formalin-induced orofacial pain and acetic acid-induced visceral pain) and one thermal assay (hot plate). SSE showed in vitro anti-inflammatory actions with IC50 values calculated as follows: 163.3 µg/ml (IL-6), 154.7 µg/ml (H2O2) and > 200 µg/ml (IL-1ß, TNF-α, and NO). SSE showed also in vivo anti-inflammatory actions in the TPA test (40% of inhibition of ear oedema) and the carrageenan test (ED50 = 137.8 mg/kg p.o.). SSE induced antinociceptive activity in the formalin orofacial pain test (ED50 = 80.1 mg/kg) and the acetic acid-induced writhing test (ED50 = 110 mg/kg). SSE showed no antinociceptive actions in the hot plate assay. The pre-treatment with glibenclamide abolished the antinociceptive action shown by SSE alone. Overall, SSE exerted in vitro and in vivo anti-inflammatory actions, and in vivo antinociceptive effects by the possible involvement of ATP-sensitive K + channels.

Immune Response of BALB/c Mice toward Putative Calcium Transporter Recombinant Protein of Trichomonas vaginalis.

Trichomoniasis is a common sexually transmitted infection caused by Trichomonas vaginalis, which actually does not exist a vaccine for control or prevention. Thus, the identification of new and potent immunogens in T. vaginalis, which can contribute to the development of a vaccine against this parasite, is necessary. Therefore, the aim of this work was to evaluate the potential of a recombinant Transient Receptor Potential-like channel of T. vaginalis (TvTRPV), as a promising immunogen in BALB/c mice. First, TvTRPV was cloned and expressed as a recombinant protein in Escherichia coli BL21 cells and purified by nickel affinity. Next, BALB/c mice were immunized and the antibody levels in mice serum and cytokines from the supernatant of macrophages and from co-culture systems were evaluated. Recombinant TvTRPV triggered high levels of specific total IgG in sera from the immunized mice. Also, a statistically significant increase of cytokines: IL-1ß, IL-6, and TNF-α after stimulation with the corresponding antigens in vitro, was identified. Moreover, co-cultures using CD4+ T cells from immunized mice were able to identify higher levels of IL-10 and IFN-γ. These results were useful to validate the immunogenicity of TvTRPV in BALB/c mice, where IL-10-IFN-γ-secreting cells could play a role in infection control, supporting the potential of TvTRPV as a promising target for vaccine against T. vaginalis.

Intestinal parasites and genotyping of Giardia duodenalis in children: first report of genotype B in isolates from human clinical samples in Mexico.

Giardia duodenalis is one of the most prevalent enteroparasites in children. This parasite produces several clinical manifestations. The aim of this study was to determine the prevalence of genotypes of G. duodenalis causing infection in a region of southeastern Mexico. G. duodenalis cysts were isolated (33/429) from stool samples of children and molecular genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, targeting the triosephosphate isomerase ( tpi ) and glutamate dehydrogenase ( gdh ) genes. The tpi gene was amplified in all of the cyst samples, either for assemblage A (27 samples) or assemblage B (6 samples). RFLP analysis classified the 27 tpi -A amplicons in assemblage A, subgenotype I. Samples classified as assemblage B were further analysed using PCR-RFLP of the gdh gene and identified as assemblage B, subgenotype III. To our knowledge, this is the first report of assemblage B of G. duodenalis in human clinical samples from Mexico.

Models in vivo and in vitro for the study of acute and chronic inflammatory activity: A comprehensive review.

Inflammatory conditions are among the principal causes of morbidity worldwide, and their treatment continues to be a challenge, given the restricted availability of effective and safe drugs. Thus, the identification of new compounds with biological activity that can be used for the treatment of inflammatory disorders is an essential field in medical and health research, in order to improve the health and quality of life of patients suffering from these diseases. Evaluation of the anti-inflammatory activity of drugs requires the implementation of models that accurately depict the biochemical and/or physiological responses that characterize human inflammation; for this reason, several in vitro and in vivo models have been developed, providing a platform for discovering novel or repurposed compounds. For this reason, in the present review we have selected twelve commonly used models for the evaluation of the anti-inflammatory effect, and extensively describes the difference between in vivo and in vitro models of inflammation, highlighting their advantages and limitations. On the other hand, the inflammatory mechanisms involved in them, the methods employed for their establishment, and the different parameters assessed to determine the anti-inflammatory activity of a given compound are extensively discussed. We expect to provide a comprehensive guide for the improved selection of a suitable model for the preclinical evaluation of plausible anti-inflammatory agents.

Short-term estimation and application of biological variation of small dense low-density lipoproteins in healthy individuals.

BACKGROUND: A number of methods have been developed to measure small dense low-density lipoprotein cholesterol (sd-LDL-C) to evaluate atherogenic risk in the population. However, to our knowledge there are no reports about the biologic variability of these lipoproteins. Therefore, the aim of this work was to estimate sd-LDL-C biological variability, and with this information establish quality specifications, index of individuality (II) and reference change values (RCV). METHODS: To estimate within- and between-subject biological variability, sd-LDL-C in serum was measured in 24 individuals (11 female and 13 male) for 5 consecutive days and then, at 2 and 3 weeks. Quality specifications, II, and RCVs were estimated according to procedures described. RESULTS: Total within- and between-subject biological variability, expressed as coefficient of variation, was 9.1% and 20%. Meanwhile, within- and between-biological variability in female and men was 10.9% and 6.7%, and 22% and 17%, respectively. Desirable quality specification to the sd-LDL-C method was 4.6% for analytical imprecision, bias 5.5% and total allowable error of 11.4%; the II was 0.46 and the RCV (calculated at 95% and 99% of significance) was 27.1% and 35.7%, for the total data. CONCLUSIONS: Short-term biological variability components were determined, and then used to estimate quality specifications, II and RCV for sd-LDL-C precipitation assay. To our knowledge, this is one of the first reports about sd-LDL-C biological variability, so that this information can be used as a starting point to develop long-term studies of biological variability for sd-LDL-C.

Detection of rotavirus and norovirus among children with acute gastroenteritis in Merida and Chihuahua cities, Mexico.

INTRODUCTION: Infantile acute gastroenteritis (AGE) is a leading cause of morbidity and mortality, particularly in developing countries. The most frequent etiological agents of viral gastroenteritis in children are adenovirus, astrovirus, rotavirus, and norovirus, the last two, leading causes. Thus, the aim of this study was to identify the presence of these two viruses in children with AGE, from two cities located in the Southeast and the Northwest regions of México. METHODOLOGY: HuNoVs were detected and characterized by RT-PCR and sequencing, while RVs were detected by RNA electrophoresis. RESULTS: The presence of RV and HuNoV was evaluated in 81 stool samples; 37 were collected between April and July 2013 from patients with acute diarrhea in Merida, and 44 were collected between January and June 2017 in Chihuahua, who attended health services. Despite vaccination, RV resulted in the predominant viruses detected, with 30.8% (25/81) positivity, while HuNoV infection was present in 8.6% (7/81) of the stool samples; GII strains were identified circulating in the Southeast, while GI strains were identified in the Northwest. Moreover, co-infections with both viruses were detected at a prevalence rate of 2.4% (2/81). CONCLUSIONS: The circulation of RV and HuNoV in the country is continuous and should be constantly monitored due to their impact on public health.

Pharmacogenetics: ethnicity, treatment and health in Latin American populations.

The Ibero-American Network of Pharmacogenetics and Pharmacogenomics (RIBEF) studies Latin American populations to benefit from the implementation of personalized medicine. Since 2006, it has studied ethnicity to apply pharmacogenetics knowledge in autochthonous populations of Latin America, considering ancestral medicine. The meeting 'Pharmacogenetics: ethnicity, Treatment and Health in Latin American Populations' was held in Mexico City, Mexico, and presented the relevance of RIBEF collaboration with Latin American researchers and the governments of Mexico, Spain and the Autonomous Community of Extremadura. The results of 17 years of uninterrupted work by RIBEF, the Declaration of Mérida/T'Hó and the call for the Dr José María Cantú Award for studies focused on the pharmacogenetics of native populations in Latin America were presented.

Natural marine products as antiprotozoal agents against amitochondrial parasites.

The goal of this work is to compile and discuss molecules of marine origin reported in the scientific literature with anti-parasitic activity against Trichomonas, Giardia, and Entamoeba, parasites responsible for diseases that are major global health problems, and Microsporidial parasites as an emerging problem. The presented data correspond to metabolites with anti-parasitic activity in human beings that have been isolated by chromatographic techniques from marine sources and structurally elucidated by spectroscopic and spectrometric procedures. We also highlight some semi-synthetic derivatives that have been successful in enhancing the activity of original compounds. The biological oceanic reservoir offers the possibility to discover new biologically active molecules as lead compounds to develop new drug candidates. The molecular variety is extensive and must be correctly explored and managed. Also, it will be necessary to take some actions to preserve the source species from extinction or overharvest (e.g., by cryopreservation of coral spermatozoa, oocytes, embryos, and larvae) and coordinate appropriate exploitation to increase the chemical knowledge of the natural products generated in the oceans. Additional initiatives such as the total synthesis of complex natural products and their derivatives can help to prevent overharvest of the marine ecosystems and at the same time contribute to the discovery of new molecules.

Clinical relevance of lipid panel and aminotransferases in the context of hepatic steatosis and fibrosis as measured by transient elastography (FibroScan®).

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease and is associated with various co-morbidities. Transient elastography (FibroScan®) is a non-invasive method to detect NAFLD using the controlled attenuation parameter (CAP). We aimed to evaluate the association of the lipid panel and aminotransferases concentrations with the presence or absence of steatosis and fibrosis. METHODS: One hundred and five patients with NAFLD were included. Hepatic steatosis was quantified by CAP (dB/m) and liver stiffness by Kilopascals (kPa), these values were then analyzed against patient lipid panel and serum concentrations of the liver enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT). A correlation and multiple regression were used. Mann-Whitney U test was used as non-parametric analysis. RESULTS: We observed an association between hepatic steatosis and total cholesterol (B = 0.021, p = 0.038, Exp (B) = 1.021, I.C = 1.001-1.041) as well as serum triglycerides (B = 0.017, p = 0.006, Exp (B) = 1.018 and I.C = 1.005-1.030). Similarly, we found an association between significant hepatic fibrosis and lower concentrations of total cholesterol (B = -0.019, p = 0.005, Exp (B) = 0.982 I.C = 0.969-0.995) and elevated AST (B = 0.042, p = 3.25 × 10-4, Exp (B) = 1.043 I.C = 1.019-1.068) independent of age, gender and BMI. CONCLUSIONS: Our results suggest that, total cholesterol and triglyceride concentrations positively correlate with hepatic steatosis while significant hepatic fibrosis is associated with lower total cholesterol and higher AST concentrations.

Challenges and Opportunities for Clinical Pharmacogenetic Research Studies in Resource-limited Settings: Conclusions From the Council for International Organizations of Medical Sciences-Ibero-American Network of Pharmacogenetics and Pharmacogenomics Meeting.

PURPOSE: The symposium Health and Medicines in Indigenous Populations of America was organized by the Council for International Organizations of Medical Sciences (CIOMS) Working Group on Clinical Research in Resource-Limited Settings (RLSs) and the Ibero-American Network of Pharmacogenetics and Pharmacogenomics (RIBEF). It was aimed to share and evaluate investigators' experiences on challenges and opportunities on clinical research and pharmacogenetics. METHODS: A total of 33 members from 22 countries participated in 2 sessions: RIBEF studies on population pharmacogenetics about the relationship between ancestry with relevant drug-related genetic polymorphisms and the relationship between genotype and phenotype in Native Americans (session 1) and case examples of clinical studies in RLSs from Asia (cancer), America (diabetes and women health), and Africa (malaria) in which the participants were asked to answer in free text their experiences on challenges and opportunities to solve the problems (session 2). Later, a discourse analysis grouping common themes by affinity was conducted. FINDINGS: The main result of session 1 was that the pharmacogenetics-related ancestry of the population should be considered when designing clinical studies in RLSs. In session 2, 21 challenges and 20 opportunities were identified. The social aspects represent the largest proportion of the challenges (43%) and opportunities (55%), and some of them seem to be common. IMPLICATIONS: The main discussion points were gathered in the Declaration of Mérida/T'Hó and announced on the Parliament of Extremadura during the CIOMS-RIBEF meeting in 4 of the major Latin American autochthonous languages (Náhualth, Mayan, Miskito, and Kichwa). The declaration highlighted the following: (1) the relevance of population pharmacogenetics, (2) the sociocultural contexts (interaction with traditional medicine), and (3) the education needs of research teams for clinical research in vulnerable and autochthonous populations.

Genetic diversity of HLA system in two populations from Yucatán, Mexico: Mérida and rural Yucatán.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 324 Mexicans from the state of Yucatán living in the city of Mérida (N = 192) and rural communities (N = 132), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in the state of Yucatán include 16 Native American and one European haplotype. Admixture estimates revealed that the main genetic components in Yucatán are Native American (81.54 ±â€¯4.99% by ML; 62.92% of Native American haplotypes) and European (11.50 ±â€¯15.43% by ML; 23.26% of European haplotypes), and a less prominent African genetic component (6.96 ±â€¯10.47% by ML; 5.93% of African haplotypes).

Genetic diversity of HLA system in two populations from Quintana Roo, Mexico: Cancún and rural Quintana Roo.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 98 Mexicans from the state of Quintana Roo living in the city of Cancún (N = 48) and rural communities (N = 50), to obtain information regarding allelic and haplotypic frequencies and their linkage disequilibrium. We found that the most frequent haplotypes in Quintana Roo include ten Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in Quintana Roo are Native American (80.85 ±â€¯3.70% by ML; 60.20% of Native American haplotypes) and European (15.19 ±â€¯14.25% by ML; 26.02% of European haplotypes), and a less prominent African genetic component (3.96 ±â€¯10.75% by ML; 6.63% of African haplotypes).