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Background Circulating cell-free mitochondrial DNA (cf-mtDNA) fragments in blood plasma have been reported in patients with schizophrenia (SZ). Although the relationship of cf-mtDNA to the cognitive status of patients with SZ has not yet been explored, it is known that cognitive impairment in SZ compromises the functional and social capacity of these patients and diminishes their quality of life. In this sense, the assessment of the severity of cognitive impairment in a Mexican population with SZ and its association with cf-mtDNA levels in blood plasma may provide the possibility of using cf-mtDNA as a biomarker to determine the status of the disease and the possible ensuing changes over time. Methods Subjects for a case-control study will be recruited. cf-mtDNA obtained from blood plasma will be quantified by real-time polymerase chain reaction, using melting curve technology with SYBR green as amplification marker. Patients with SZ will be grouped into those with severe, mild, and no cognitive impairment according to Montreal Cognitive Assessment scale scores, to determine differences between cognitive performance and cf-mtDNA levels in blood plasma. Ethics and communication This study has been approved by the ethics and investigation committees of the High Specialty Regional Hospital of Mental Health (Hospital Regional de Alta Especialidad de Salud Mental); project No. HRAESM/DG/RP/1128/2018. We plan to communicate our research findings in scientific conferences and in peer-reviewed journals. Conclusion It is known that cognitive dysfunction provokes negative effects in an SZ patient´s life. This project aims to provide better knowledge about the role of cf-mtDNA in the pathogenesis of cognitive impairment in SZ, as an attempt to achieve improvements to the existing treatments, thereby helping to prevent major cognitive deterioration.

Background It is accepted that there is a genetic factor that influences the risk of suicidal behavior. The catechol-O-methyltransferase (COMT) gene, especially the Val108/158Met polymorphism, has been associated with suicide; however, no conclusive outcome has been attained. Therefore, the aim of the present study was to assess the role of COMT Val108/158Met in suicidal behavior throughout an updated meta-analysis. Methods We performed an online search using PubMed and Web of Science (up to March 2017). Our systematic review included case-control studies of individuals who attempted suicide and completed suicide. We tested allelic, homozygous, heterozygous, dominant, and recessive inheritance models. The meta-analysis was performed in accordance with the statement of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Results The meta-analysis comprised 17 studies, which included 3,282 cases and 3,774 controls, and showed that when evaluating the overall population, the Val108/158Met polymorphism of COMT was not associated with suicidal behavior in any of the inheritance models; however, the subanalyses showed that this polymorphism exhibits a risk factor in males and a protective effect in females. Additionally, it conveyed a risk factor in Asian populations when using the allelic (OR 1.25; CI: 1.04-1.51) and recessive models (OR 1.32; CI: 1.03-1.68). Conclusion Our updated meta-analysis suggests a possible association between COMT Val108/158Met and suicidal behavior in Asian populations. However, in view of the small number of studies, these results should be considered exploratory. We recommend that more studies be performed with larger samples.

Background The aim of this case–control study was to explore the association by gender between the HTR2C gene variants and suicidal behavior in a Mexican population. Subjects and methods A total of 183 suicide attempters and 208 healthy volunteers were included in this study. We genotyped five polymorphisms of HTR2C (rs547536, rs2192372, rs4272555, rs6318, and rs2428707), then measured the association by genotype, allele, and haplotype. Results In the female group, we found an association between two polymorphisms of the HTR2C (rs4272555 and rs2428707) and suicide attempts. The C allele of the single-nucleotide polymorphism (SNP) rs4272555 was associated with a decreased risk of suicide attempt (P=0.01, odds ratio =0.26, 95% confidence interval: 0.09–0.79), whereas the G allele of the SNP rs2428707 was associated with an increased risk of suicide attempt (P=0.01, odds ratio =3.68, 95% confidence interval: 1.24–10.90). No significant association was observed between the other polymorphisms studied (rs547536, rs2192372, rs6318) or haplotypes with suicide attempts. Conclusion These findings suggest a possible risk factor of the HTR2C gene in the pathology of suicidal behavior in Mexican population. More studies are necessary to confirm this association.

Background Circulating cell-free mitochondrial DNA (cf-mtDNA) fragments in blood plasma have been reported in patients with schizophrenia (SZ). Although the relationship of cf-mtDNA to the cognitive status of patients with SZ has not yet been explored, it is known that cognitive impairment in SZ compromises the functional and social capacity of these patients and diminishes their quality of life. In this sense, the assessment of the severity of cognitive impairment in a Mexican population with SZ and its association with cf-mtDNA levels in blood plasma may provide the possibility of using cf-mtDNA as a biomarker to determine the status of the disease and the possible ensuing changes over time. Methods Subjects for a case–control study will be recruited. cf-mtDNA obtained from blood plasma will be quantified by real-time polymerase chain reaction, using melting curve technology with SYBR green as amplification marker. Patients with SZ will be grouped into those with severe, mild, and no cognitive impairment according to Montreal Cognitive Assessment scale scores, to determine differences between cognitive performance and cf-mtDNA levels in blood plasma. Ethics and communication This study has been approved by the ethics and investigation committees of the High Specialty Regional Hospital of Mental Health (Hospital Regional de Alta Especialidad de Salud Mental); project No. HRAESM/DG/RP/1128/2018. We plan to communicate our research findings in scientific conferences and in peer-reviewed journals. Conclusion It is known that cognitive dysfunction provokes negative effects in an SZ patient´s life. This project aims to provide better knowledge about the role of cf-mtDNA in the pathogenesis of cognitive impairment in SZ, as an attempt to achieve improvements to the existing treatments, thereby helping to prevent major cognitive deterioration.

Mirna Edith Morales-Marín,1 Alma Delia Genis-Mendoza,1,2 Carlos Alfonso Tovilla-Zarate,3 Nuria Lanzagorta,4 Michael Escamilla,5 Humberto Nicolini1,4 1Genomics of Psychiatric and Neurodegenerative Diseases Laboratory, National Institute of Genomic Medicine (INMEGEN), CDMX, Mexico; 2Psychiatric Care Services, Child Psychiatric Hospital Dr Juan N Navarro, CDMX, Mexico; 3Genomics Research Center, Juarez Autonomous University of Tabasco, Comalcalco, Mexico; 4Carracci Medical Group, CDMX, Mexico; 5Department of Psychiatry, Paul L Foster School of Medicine, Texas Tech University Health Science Center, El Paso TX, USA Background: The brain-derived neurotrophic factor (BDNF) has been considered as an important candidate gene in bipolar disorder (BD); this association has been derived from several genetic and genome-wide studies. A polymorphic variant of the BDNF (Val66Met) confers some differences in the clinical presentation of affective disorders. In this study, we evaluated a sample population from Mexico City to determine whether the BDNF (rs6265) Val66Met polymorphism is associated with the body mass index (BMI) of patients with BD.Methods: This association study included a sample population of 357 individuals recruited in Mexico City. A total of 139 participants were diagnosed with BD and 137 were classified as psychiatrically healthy controls (all individuals were interviewed and evaluated by the Diagnostic Interview for Genetic Studies). Genomic DNA was extracted from peripheral blood leukocytes. The quantitative polymerase chain reaction (qPCR) assay was performed in 96-well plates using the TaqMan Universal Thermal Cycling Protocol. After the PCR end point was reached, fluorescence intensity was measured in a 7,500 real-time PCR system and evaluated using the SDS v2.1 software, results were analyzed with Finetti and SPSS software. Concerning BMI stratification, random groups were defined as follows: normal 30 kg/m2.Results: In the present work, we report the association of a particular BMI phenotype with the presence of the Val66Met allele in patients with BD (P=0.0033 and odds ratio [95% confidence interval] =0.332 [157–0.703]), and correlated the risk for valine allele carriers with Ow and Ob in patients with BD.Conclusion: We found that the methionine allele confers a lower risk of developing Ow and Ob in patients with BD. We also confirmed that the G polymorphism represents a risk of developing Ow and Ob in patients with BD. In future studies, the haplotype analysis should provide additional evidence that BDNF may be associated with BD and BMI within the Mexican population. Keywords: brain-derived neurotrophic factor, bipolar disorder, single nucleotide polymorphism, body mass index

Isela Esther Juárez-Rojop,1 Carlos Mario Fortuny-Falconi,2 Thelma Beatriz González-Castro,3 Carlos Alfonso Tovilla-Zárate,2 Mario Villar-Soto,4 Ester Rodríguez Sanchez,4 Yazmín Hernández-Díaz,3 María Lilia López-Narvaez,5 Jorge L Ble-Castillo,1 Nonanzit Pérez-Hernández,6 José Manuel Rodríguez-Pérez6 1Multidisciplinary Academic Division of Health Sciences; Juarez Autonomous University of Tabasco, Villahermosa, Tabasco, Mexico; 2Multidisciplinary Academic Division of Comalcalco; Juarez Autonomous University of Tabasco, Comalcalco, Tabasco, Mexico; 3Multidisciplinary Academic Division of Jalpa de Méndez; Juarez Autonomous University of Tabasco, Jalpa de Méndez, Tabasco, Mexico; 4Psychiatric Care Services, Hospital of high specialty “Gustavo A. Rovirosa Pérez”, Ministry of Health, Villahermosa, Tabasco, Mexico; 5Pediatric Care Services, General Hospital of Yajalon “Dr. Manuel Velasco Suarez”, Yajalon, Chiapas, Mexico; 6Department of Molecular Biology, National Institute of Cardiology Ignacio Chávez, Mexico City, Mexico Background: Diabetes mellitus is a chronic disease that requires attention and commitment on the part of patients; improving the quality of life of these patients reduces health costs, morbidity, and mortality. We focused on investigating the factors related with the quality of life and depression symptomatology in patients with type 2 diabetes.Participants and methods: A total of 173 Mexican patients with type 2 diabetes were recruited. An interview face-to-face, a sociodemographic characteristics questionnaire, the Short Form 36 (SF-36), and the Clinical Epidemiological Studies of Depression were applied. The biochemical parameters measured were blood glucose, cholesterol, triacylglycerol levels, and glycated hemoglobin.Results: In all SF-36 subscales, female patients had lower scores in comparison with male patients; individuals ≥65 years of age showed less physical function. We observed that married patients presented a better quality of life than people who were widowed or divorced (P

Background It is accepted that there is a genetic factor that influences the risk of suicidal behavior. The catechol-O-methyltransferase (COMT) gene, especially the Val108/158Met polymorphism, has been associated with suicide; however, no conclusive outcome has been attained. Therefore, the aim of the present study was to assess the role of COMT Val108/158Met in suicidal behavior throughout an updated meta-analysis. Methods We performed an online search using PubMed and Web of Science (up to March 2017). Our systematic review included case-control studies of individuals who attempted suicide and completed suicide. We tested allelic, homozygous, heterozygous, dominant, and recessive inheritance models. The meta-analysis was performed in accordance with the statement of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Results The meta-analysis comprised 17 studies, which included 3,282 cases and 3,774 controls, and showed that when evaluating the overall population, the Val108/158Met polymorphism of COMT was not associated with suicidal behavior in any of the inheritance models; however, the subanalyses showed that this polymorphism exhibits a risk factor in males and a protective effect in females. Additionally, it conveyed a risk factor in Asian populations when using the allelic (OR 1.25; CI: 1.04–1.51) and recessive models (OR 1.32; CI: 1.03–1.68). Conclusion Our updated meta-analysis suggests a possible association between COMT Val108/158Met and suicidal behavior in Asian populations. However, in view of the small number of studies, these results should be considered exploratory. We recommend that more studies be performed with larger samples.

Background The aim of this case–control study was to explore the association by gender between the HTR2C gene variants and suicidal behavior in a Mexican population. Subjects and methods A total of 183 suicide attempters and 208 healthy volunteers were included in this study. We genotyped five polymorphisms of HTR2C (rs547536, rs2192372, rs4272555, rs6318, and rs2428707), then measured the association by genotype, allele, and haplotype. Results In the female group, we found an association between two polymorphisms of the HTR2C (rs4272555 and rs2428707) and suicide attempts. The C allele of the single-nucleotide polymorphism (SNP) rs4272555 was associated with a decreased risk of suicide attempt (P=0.01, odds ratio =0.26, 95% confidence interval: 0.09–0.79), whereas the G allele of the SNP rs2428707 was associated with an increased risk of suicide attempt (P=0.01, odds ratio =3.68, 95% confidence interval: 1.24–10.90). No significant association was observed between the other polymorphisms studied (rs547536, rs2192372, rs6318) or haplotypes with suicide attempts. Conclusion These findings suggest a possible risk factor of the HTR2C gene in the pathology of suicidal behavior in Mexican population. More studies are necessary to confirm this association.