Individual and Combined Effect of MAO-A/MAO-B Gene Variants and Adverse Childhood Experiences on the Severity of Major Depressive Disorder.

BACKGROUND: Major depressive disorder (MDD) is a mood disorder with a high prevalence worldwide that causes disability and, in some cases, suicide. Although environmental factors play a crucial role in this disease, other biological factors may predispose individuals to MDD. Genetic and environmental factors influence mental disorders; therefore, a potential combined effect of MAO-A/MAO-B gene variants may be a target for the study of susceptibility to MDD. This study aimed to evaluate the effects of MAO-A and -B gene variants when combined with adverse childhood experiences (ACEs) on the susceptibility and severity of symptoms in MDD. METHODS: A case-control study was performed, including 345 individuals, 175 MDD cases and 170 controls. Genotyping was performed using real-time PCR with hydrolysis probes. The analysis of the rs1465107 and rs1799836 gene variants of MAO-A and -B, respectively, was performed either alone or in combination with ACEs on the severity of depression, as determined through specific questionnaires, including DSM-IV diagnostic criteria for MDD. RESULTS: According to individual effects, the presence of ACEs, as well as the allele G of the rs1465107 of MAO-A, is associated with a higher severity of depression, more significantly in females. Furthermore, the allele rs1799836 G of MAO-B was associated with the severity of depression, even after being adjusted by gene variants and ACEs (IRR = 1.67, p = 0.01). In males, the allele rs1799836 G of MAO-B was shown to interact with SNP with ACEs (IRR = 1.70, p < 0.001). According to combined effect analyses, the severity of depression was associated with ACEs when combined with either allele rs1465107 of MAO-A or allele rs17993836 of MAO-B, whereas SNP risk association was influenced by gender. CONCLUSIONS: The severity of depression is related to either individual or combined effects of temperamental traits and genetic susceptibility of specific genes such as MAO-A and MAO-B.

Family Functioning and Suicide Attempts in Mexican Adolescents.

Suicide is considered a public health problem that affects families worldwide. Family functioning is the capability of the family system to fulfill needs during the stages of its development. In this study, we focused on evaluating family cohesion and adaptability in a group of adolescents who had attempted suicide and were hospitalized at a hospital for mental health disorders, compared to a control group. Methods: based on Olson's circumplex model, we used the FACES III scale to gain insights into the family functioning of both suicidal and control groups. Results: The case group presented lower scores in cohesion and adaptability compared to the control group, with moderate effect-size for cohesion (Cohen's d/r test = 1.217/0.52) and low effect-size for adaptability (Cohen's d/r test = 0.746/0.35) (p < 0.001 for both variables), and also presented predominantly disengaged families (72.5% in the case group vs. 27.5% in the control group) and structured families (45% in the case group vs. 23.8% in the control group). The type of family described by the adolescents with a history of suicide attempts may explain the presence of low self-esteem and little emotional support usually present in this type of patient.

Quality and Safety in Healthcare for Medical Students: Challenges and the Road Ahead.

Background: The development of skills, behaviors and attitudes regarding patient safety is of utmost importance for promoting safety culture for the next generation of health professionals. This study describes our experience of implementing a course on patient safety and quality improvement for fourth year medical students in Mexico during the COVID-19 outbreak. The course comprised essential knowledge based on the patient safety curriculum provided by the WHO. We also explored perceptions and attitudes of students regarding patient safety. Methods: Fourth year medical students completed a questionnaire regarding knowledge, skills, and attitudes on patient safety and quality improvement in medical care. The questionnaire was voluntarily answered online prior to and after the course. Results: In total, 213 students completed the questionnaires. Most students were able to understand medical error, recognize failure and the nature of causation, perform root-cause analysis, and appreciate the role of patient safety interventions. Conversely, a disapproving perspective prevailed among students concerning the preventability of medical errors, utility of reporting systems, just culture and infrastructure (p < 0.05). Conclusion: We found students had a positive perspective concerning learning quality in healthcare and patient safety during our course; nevertheless, their perception of the usefulness of reporting systems to prevent future adverse events and prevent medical errors is uncomplimentary. Medical education should promote error reporting and just culture to change the current perception of medical students.

Analysis of the rs13306560 functional variant in the promoter region of the MTHFR gene in sporadic Parkinson´s disease.

OBJECTIVE: Among susceptibility genes for Sporadic Parkinson´s Disease (SPD), the MTHFR gene has been suggested as candidate. The A allele of the functional variant rs13306560 in its promoter region has been liked to decreased transactivation capacity. Therefore, we sought to determine a possible association of the rs13306560 and SPD. METHODS: In total, 237 individuals were genotyped, 113 patients with SPD diagnosed according to the Queen Square Brain Bank criteria and 124 neurologically healthy controls. Genotyping was performed using TaqMan probes for the rs13306560 and real-time PCR. RESULTS: The A allelle was associated to protection in SPD, under the dominant model, (OR=0.22, C.I.=[0.048-1.080], p=0.04), nevertheless, after logistic regression analysis with adjustment for gender, resulted only in a trend (Exp (ß)=0.211, [I.C. 95.0%, 0.042-1.057], p=0.058). CONCLUSION: Although further studies are needed, our data suggest an important role of the MTHFR gene variants in the fine-tuning regulation of one-carbon metabolism in the brain.

Polysomnography-based diagnosis in Mexican adult patients with Obstructive Sleep Apnea Syndrome (OSAS) clinical suspicion.

INTRODUCTION: Obstructive sleep apnea syndrome (OSA) occurs in 2-4% of adults, increasing by 2.5 times the risk of sudden death. OBJECTIVE: Establish the concordance of the clinical diagnostic and electrical diagnosis in an adult series that underwent polysomnography. MATERIALS AND METHODS: Patients with sleep disorders that underwent consecutively polysomnography recording. RESULTS: In this study, 51 subjects from 24 to 77 years old (54.1±12.12) were included in the study; 23 males and 28 females; 78.43% were overweight or obese; 35.29% were smokers; 31.37% alcohol consumers; 47.05% hypertensive; 21% diabetics; 35.29% with airway alterations; 29.41% with depression; 13.72% dyslipidaemic and 7.84% with ischemic heart disease. Only 22 of the subjects qualified for OSA and the concordance between the clinical diagnostic and polysomnographic recording was 54% (Ko=0.60, Ke 0.50, Ka=0.20) with a 0.55 sensibility, 0.66 specificity, PPV 0.54, NPV 0.65, PLR 1.2, RVN 0.69 and PPP 0.47. The neck circumference in OSA was 40.68±5 vs. 37.7±3.5 cm. (p<0.02) and BMI was 36.48±13.16 vs 29.37±6.58 (p<0.008); male/female proportion was 1.8:1 (p<0.01), BMI was higher in OSA (p<0.002). The Epworth Sleepiness Scale did not discriminate between OSA and other sleep alteration (p<0.29). DISCUSSION AND CONCLUSIONS: We observed a poor agreement between clinical diagnosis and polysomnography. The Epworth Sleepiness Scale did not discern between OSA and other sleep disorders and finally there was no association with a systemic process.

Low Proteolytic Clipping of Histone H3 in Cervical Cancer.

Chromatin in cervical cancer (CC) undergoes chemical and structural changes that alter the expression pattern of genes. Recently, a potential mechanism, which regulates gene expression at transcriptional levels is the proteolytic clipping of histone H3. However, until now this process in CC has not been reported. Using HeLa cells as a model of CC and human samples from patients with CC, we identify that the H3 cleavage was lower in CC compared with control tissue. Additionally, the histone H3 clipping was performed by serine and aspartyl proteases in HeLa cells. These results suggest that histone H3 clipping operates as part of post-translational modification system in CC.

Serum Levels of MicroRNA-206 and Novel Mini-STR Assays for Carrier Detection in Duchenne Muscular Dystrophy.

Duchenne Muscular Dystrophy (DMD) is an X-linked neuromuscular disorder in which the detection of female carriers is of the utmost importance for genetic counseling. Haplotyping with polymorphic markers and quantitation of creatine kinase levels (CK) allow tracking of the at-risk haplotype and evidence muscle damage, respectively. Such approaches are useful for carrier detection in cases of unknown mutations. The lack of informative markers and the inaccuracy of CK affect carrier detection. Therefore, herein we designed novel mini-STR (Short Tandem Repeats) assays to amplify 10 loci within the DMD gene and estimated allele frequencies and the polymorphism information content among other parameters in 337 unrelated individuals from three Mexican populations. In addition, we tested the utility of the assays for carrier detection in three families. Moreover, given that serum levels of miR-206 discern between DMD patients and controls with a high area under the curve (AUC), the potential applicability for carrier detection was assessed. The serum levels of miR-206 of non-carriers (n = 24) and carriers (n = 23) were compared by relative quantitation using real-time PCR (p < 0.05), which resulted in an AUC = 0.80 in the Receiver Operating Characteristic curve analysis. In conclusion, miR-206 has potential as a "liquid biopsy" for carrier detection and genetic counseling in DMD.

[Intracellular signaling mechanisms in thyroid cancer]. / Mecanismos de señalización intracelular en cáncer de tiroides.

BACKGROUND: Thyroid cancer is the most common malignancy of the endocrine system, the papillary variant accounts for 80-90% of all diagnosed cases. In the development of papillary thyroid cancer, BRAF and RAS genes are mainly affected, resulting in a modification of the system of intracellular signaling proteins known as «protein kinase mitogen-activated¼ (MAPK) which consist of «modules¼ of internal signaling proteins (Receptor/Ras/Raf/MEK/ERK) from the cell membrane to the nucleus. In thyroid cancer, these signanling proteins regulate diverse cellular processes such as differentiation, growth, development and apoptosis. MAPK play an important role in the pathogenesis of thyroid cancer as they are used as molecular biomarkers for diagnostic, prognostic and as possible therapeutic molecular targets. Mutations in BRAF gene have been correlated with poor response to treatment with traditional chemotherapy and as an indicator of poor prognosis. OBJECTIVE: To review the molecular mechanisms involved in intracellular signaling of BRAF and RAS genes in thyroid cancer. CONCLUSIONS: Molecular therapy research is in progress for this type of cancer as new molecules have been developed in order to inhibit any of the components of the signaling pathway (RET/PTC)/Ras/Raf/MEK/ERK; with special emphasis on the (RET/PTC)/Ras/Raf section, which is a major effector of ERK pathway.

Polymorphisms of APLN-APLNR system are associated with essential hypertension in Mexican-Mestizo individuals.

The aim of this study was to evaluate if polymorphisms of APLN and APLNR genes may play a role as susceptibility markers for hypertension in a group of Mexican-Mestizo patients. A case-control study was carried out including normotensive and hypertensive individuals. For these, two polymorphisms of APLN (rs3761581 and rs56204867) and two of APLNR () genes were genotyped by 5' exonuclease TaqMan assay in 400 normotensive individuals and 383 patients. The results showed that, under an additive model adjusted by BMI, HDL, triglycerides, glucose and family history of essential hypertension, the rs7119375 and rs10501367 polymorphisms of APLNR gene were associated significantly with a decreased risk of essential hypertension (P=0.039 and P=0.029, respectively). Besides, the haplotypes analysis of these polymorphisms showed that H1 haplotype was associated with an increased risk of essential hypertension (P=0.026), while the H2 haplotype was associated with a decreased risk (P=0.032). Contrary, the rs3761581 and rs56204867 polymorphisms of APLN gene were not associated with essential hypertension (P=0.1707 and P=0.0769, respectively). The data suggest that APLNR rs7119375 and rs10501367 are associated with a decreased risk of essential hypertension in our Mexican-Mestizo studied group, but further studies are warranted.

Non-Invasive Biomarkers for Duchenne Muscular Dystrophy and Carrier Detection.

Non-invasive biological indicators of the absence/presence or progress of the disease that could be used to support diagnosis and to evaluate the effectiveness of treatment are of utmost importance in Duchenne Muscular Dystrophy (DMD). This neuromuscular disorder affects male children, causing weakness and disability, whereas female relatives are at risk of being carriers of the disease. A biomarker with both high sensitivity and specificity for accurate prediction is preferred. Until now creatine kinase (CK) levels have been used for DMD diagnosis but these fail to assess disease progression. Herein we examined the potential applicability of serum levels of matrix metalloproteinase 9 and matrix metalloproteinase 2, tissue inhibitor of metalloproteinases 1, myostatin (GDF-8) and follistatin (FSTN) as non-invasive biomarkers to distinguish between DMD steroid naïve patients and healthy controls of similar age and also for carrier detection. Our data suggest that serum levels of MMP-9, GDF-8 and FSTN are useful to discriminate DMD from controls (p < 0.05), to correlate with some neuromuscular assessments for DMD, and also to differentiate between Becker muscular dystrophy (BMD) and Limb-girdle muscular dystrophy (LGMD) patients. In DMD individuals under steroid treatment, GDF-8 levels increased as FSTN levels decreased, resembling the proportions of these proteins in healthy controls and also the baseline ratio of patients without steroids. GDF-8 and FSTN serum levels were also useful for carrier detection (p < 0.05). Longitudinal studies with larger cohorts are necessary to confirm that these molecules correlate with disease progression. The biomarkers presented herein could potentially outperform CK levels for carrier detection and also harbor potential for monitoring disease progression.

Functional Polymorphism rs13306560 of the MTHFR Gene Is Associated With Essential Hypertension in a Mexican-Mestizo Population.

BACKGROUND: Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) have been associated with diastolic blood pressure, hypertension, and other cardiovascular diseases; however, results of these studies are still controversial. In this study, we sought to determine whether 2 functional variants (rs1801133 and rs13306560) within the MTHFR are associated with hypertension in Mexican-Mestizos. METHODS AND RESULTS: We performed a case-control study with 1214 subjects including adults and children to test for the association of both single nucleotide polymorphisms with essential hypertension. The adult group included 764 participants (372 patients and 391 controls) and the group of children included 418 participants (209 patients and 209 controls). rs13306560 was associated with essential hypertension in adults (odds ratio, 4.281; 95% confidence interval, 1.841-9.955; P=0.0003) with a statistical power >0.8. In children, none of the polymorphisms was associated with essential hypertension. In addition, we assessed the effect of the rs13306560 polymorphism on the MTHFR promoter region by means of luciferase reporter gene assays using human umbilical vein endothelial cells. Cells transfected with the pMTHFRaLUC construct showed an ≈25% reduction in luciferase activity (P=0.003). Furthermore, the promoter activity was reduced considerably by in vitro methylation of CpG sequences. CONCLUSIONS: Our data suggest that the rs13306560 polymorphism of the MTHFR may be part of the observed hypertension process in Mexican-Mestizo populations, but further studies are warranted. In addition, the allele A of the rs13306560 polymorphism as well as the in vitro methylation of CpGs reduced the promoter activity of the MTHFR regulatory region.

Comparison of mutation profiles in the Duchenne muscular dystrophy gene among populations: implications for potential molecular therapies.

Novel therapeutic approaches are emerging to restore dystrophin function in Duchenne Muscular Dystrophy (DMD), a severe neuromuscular disease characterized by progressive muscle wasting and weakness. Some of the molecular therapies, such as exon skipping, stop codon read-through and internal ribosome entry site-mediated translation rely on the type and location of mutations. Hence, their potential applicability worldwide depends on mutation frequencies within populations. In view of this, we compared the mutation profiles of the populations represented in the DMD Leiden Open-source Variation Database with original data from Mexican patients (n = 162) with clinical diagnosis of the disease. Our data confirm that applicability of exon 51 is high in most populations, but also show that differences in theoretical applicability of exon skipping may exist among populations; Mexico has the highest frequency of potential candidates for the skipping of exons 44 and 46, which is different from other populations (p < 0.001). To our knowledge, this is the first comprehensive comparison of theoretical applicability of exon skipping targets among specific populations.

Analysis of ERCC1 and ERCC2 gene variants in osteosarcoma, colorectal and breast cancer.

The Asn118Asn (rs11615) variant in the ERCC1 gene, and the Lys751Gln (rs13181) and Asp312Asn (rs1799793) variants in the ERCC2 gene have been associated with the development of varied types of cancer. The aim of the present study was to test for any association between the ERCC1 and ERCC2 gene variants and three different types of cancer in Mexican-mestizo patients. Patients and their respective controls were formed into three groups: The osteosarcoma group, with 28 patients and 97 controls; the colorectal group, with 108 patients and 119 controls; and the breast cancer group, with 71 patients and 74 controls. Genotyping was performed using TaqMan probes and quantitative polymerase chain reaction. Allele and genotype frequencies were compared using a χ2 test. Only one SNP (rs1799793) was found to be associated with breast cancer. This is the first study analyzing the SNPs in ERCC1 and ERCC2 genes and the susceptibility to cancer in Mexican-mestizo patients with osteosarcoma, and colorectal and breast cancer.

Low prevalence of most frequent pathogenic variants of six PARK genes in sporadic Parkinson's disease.

Genetic variants that confer susceptibility to Parkinson's disease (PD) show unbalanced distribution among different populations; genetic predisposition to either familial or sporadic forms of PD in Mexican-mestizo population has not been comprehensively studied. The aim of the present study was to analyze genetic variants in six PARK genes in PD patients. In total 381 individuals (173 patients, 208 controls) were genotyped for p.Gly2019Ser and p.Gly2385Arg variants of LRRK2. The p.Gly2019Ser variant was present in two patients and one healthy control; the p.Gly2385Arg variant was not found. In a subgroup of early-onset PD (EOPD), MLPA analysis was done for PARKIN (PARK2), PINK1 (PARK6), DJ-1 (PARK7), LRRK2 (PARK8), SNCA (PARK1/4) and ATP13A2 (PARK9). We found a heterozygous deletion of exon 2 in PARK2 in the youngest patient of the early-onset group, who showed limited response to antiparkinsonian therapy. Although the changes Gly2019Ser and Gly2385Arg of LRRK2 are associated with PD in different populations; they may be a rare cause of PD in our population. Novel population-specific variants may underlie PD susceptibility in Mexican mestizos. Our study suggests that the heterozygous deletion of exon 2 in the PARK2 gene is a risk factor for EOPD.