KRAS Exon 2 Mutations in Patients with Sporadic Colorectal Cancer: Prevalence Variations in Mexican and Latin American Populations.

We searched for the prevalence of actionable somatic mutations in exon 2 of the KRAS gene in western Mexican patients with CRC. Tumor tissue DNA samples from 150 patients with sporadic CRC recruited at the Civil Hospital of Guadalajara were analyzed. Mutations in exon 2 of the KRAS gene were identified using Sanger sequencing, and the data were analyzed considering clinical-pathological characteristics. Variants in codon 12 (rs121913529 G>A, G>C, and G>T) and codon 13 (rs112445441 G>A) were detected in 26 patients (with a prevalence of 17%). No significant associations were found between these variants and clinical-pathological characteristics (p > 0.05). Furthermore, a comprehensive search was carried out in PubMed/NCBI and Google for the prevalence of KRAS exon 2 mutations in Latin American populations. The 17 studies included 12,604 CRC patients, with an overall prevalence of 30% (95% CI = 0.26-0.35), although the prevalence ranged from 13 to 43% across the different data sources. Determining the variation and frequency of KRAS alleles in CRC patients will enhance their potential to receive targeted treatments and contribute to the understanding of the genomic profile of CRC.

An Indoor Navigation Methodology for Mobile Devices by Integrating Augmented Reality and Semantic Web.

Indoor navigation systems incorporating augmented reality allow users to locate places within buildings and acquire more knowledge about their environment. However, although diverse works have been introduced with varied technologies, infrastructure, and functionalities, a standardization of the procedures for elaborating these systems has not been reached. Moreover, while systems usually handle contextual information of places in proprietary formats, a platform-independent model is desirable, which would encourage its access, updating, and management. This paper proposes a methodology for developing indoor navigation systems based on the integration of Augmented Reality and Semantic Web technologies to present navigation instructions and contextual information about the environment. It comprises four modules to define a spatial model, data management (supported by an ontology), positioning and navigation, and content visualization. A mobile application system was developed for testing the proposal in academic environments, modeling the structure, routes, and places of two buildings from independent institutions. The experiments cover distinct navigation tasks by participants in both scenarios, recording data such as navigation time, position tracking, system functionality, feedback (answering a survey), and a navigation comparison when the system is not used. The results demonstrate the system's feasibility, where the participants show a positive interest in its functionalities.

High frequency of MLH1 promoter methylation mediated by gender and age in colorectal tumors from Mexican patients.

INTRODUCTION: Several genes determine the development of colorectal cancer (CRC), such as MLH1, which encodes a protein that participates in DNA repair. MLH1 hypermethylation has been associated with gene silencing. OBJECTIVE: To analyze the methylation of five regions of MLH1 CpG island in colorectal tumors from Mexican patients. MATERIALS AND METHODS: One hundred and one tumor tissue samples were obtained from Mexican patients with CRC who provided informed consent. DNA was subjected to bisulfite conversion. Methylation of all five regions of the CpG island was evaluated using methylation-specific PCR. RESULTS: The frequency of methylation in Mexican patients with CRC was 25%. Regions A and B methylation was the main observed pattern (60%). Female patients showed a higher frequency of methylation (71%; OR 3.085; CI: 1.85-8.03; p = 0.02), and out of total methylated samples, 80% corresponded to individuals older than 45 years (p < 0.05). CONCLUSION: We calculated a methylation frequency for the MLH1 gene of 25% in Mexican patients with CRC, with this being the first report for this population. Female patients and patients older than 45 years showed a higher frequency of methylation.

INTRODUCCIÓN: Varios genes determinan el desarrollo de cáncer colorrectal (CCR), como MLH1, el cual codifica una proteína que participa en la reparación del ADN. La hipermetilación de MLH1 ha sido asociado con silenciamiento génico. OBJETIVO: Analizar la metilación de cinco regiones de la isla CpG de MLH1 en tumores colorrectales de pacientes mexicanos. MATERIALES Y MÉTODOS: Se obtuvieron 101 muestras de tejido tumoral de pacientes mexicanos con CCR, quienes proporcionaron su consentimiento informado. El ADN fue sometido a conversión por bisulfito. La metilación de las cinco regiones de la isla CpG fue evaluada utilizando PCR específica para metilación. RESULTADOS: La frecuencia de metilación en pacientes mexicanos con CCR fue del 25%. La metilación de las regiones A y B fue el principal patrón observado (60%). Las pacientes de sexo femenino mostraron una mayor frecuencia de metilación (71%) (odds ratio: 3.085; intervalo de confianza; 1.85-8.03; p = 0.02); y del total de muestras metiladas, el 80% fueron individuos mayores de 45 años (p < 0.05). CONCLUSIÓN: Calculamos una frecuencia de metilación para el gen MLH1 del 25% en pacientes mexicanos con CCR, siendo el primer reporte para esta población. Pacientes de sexo femenino y pacientes mayores de 45 años mostraron una mayor frecuencia de metilación.

Prevalence of the BRAF p.v600e variant in patients with colorectal cancer from Mexico and its estimated frequency in Latin American and Caribbean populations.

This study aimed to investigate the frequency of the somatic BRAF p.V600E in patients with colorectal cancer (CRC) in Mexico and compare it with those estimated for Latin American and Caribbean populations. One hundred and one patients with CRC with AJCC stages ranging I-IV from Western Mexico were included, out of which 55% were male and 61% had AJCC stage III-IV, with a mean age of 60 years. PCR-Sanger sequencing was used to identify the BRAF p.V600E variant. In addition, a systematic literature search in PubMed/Medline database and Google of the 42 countries in Latin America and the Caribbean led to the collection of information on the BRAF p.V600E variant frequency of 17 population reports. To compare the BRAF variant prevalence among populations, a statistical analysis was performed using GraphPad Prism V.6.0. We found that 4% of patients with CRC were heterozygous for the p.V600E variant. The χ2 test showed no significant difference (p>0.05) in p.V600E detection when comparing with other Latin American and Caribbean CRC populations, except for Chilean patients (p=0.02). Our observational study provides the first evidence on the frequency of BRAF p.V600E in patients with CRC from Western Mexico, which is 4%, but increases to 7.8% for all of Latin America and the Caribbean. The patient mean age and genetic descent on the observed frequencies of the variant in populations could influence the frequency differences.

A family of saturated controllers for UWMRs.

Input saturation appears in a physical system when a large power dissipation is requested. In this situation, and specifically for unicycle-type wheeled mobile robots, actuators only can deliver a finite amount of power. Thus, in practice the linear and angular velocity input of this class of mobile robots is limited and this should be considered in the control design. In this paper, a family of controllers that produce saturated velocity input for unicycle-type wheeled mobile robots is presented. The proposed family of controllers is designed to satisfy the trajectory tracking control goal. Sufficient conditions to prove the closed-loop system global asymptotic stability are established by using Lyapunov's theory. Already reported schemes and original designs are shown to satisfy the properties of the given family of controllers. By using two different motion tasks, experimental tests in real-time with five saturated control schemes are presented in order to validate the proposed theory. In order to show the ability of the family of controllers to produce limited control action, experiments have also been carried out with an unsaturated algorithm. Better tracking accuracy is obtained with the original design derived from the proposed class of algorithms.

Methylation analysis of MIR200 family in Mexican patients with colorectal cancer.

The present study aimed to analyze the methylation pattern of the MIR200 family in the colorectal tissues and peripheral blood of colorectal cancer (CRC) patients. Previous informed consent, 102 samples of colorectal tissues (tumor and adjacent normal tissues) and 40 peripheral blood samples were collected from CRC patients. Additionally, we included a reference group of 40 blood samples. DNA extraction was done for colorectal tissues and peripheral blood. For methylation-specific PCR, we used bisulfite-treated DNA and controls for methylated and unmethylated DNA were included to each assay. PCR fragments were separated by 6% polyacrylamide gel electrophoresis. Methylation-positive and methylation-negative results were confirmed by bisulfite genomic sequencing technique. We analyzed 102 colorectal tissues and 40 blood samples from 51 CRC patients. MIR200B/MIR200A/MIR429 methylation analysis discloses no differences among tissues (p>0.05). However, MIR200C/MIR141 methylation showed differences between colorectal tissues and peripheral blood of CRC patients (p<0.0001) and mainly methylated alleles were observed in peripheral blood. These findings suggest a tissue-specific methylation pattern for the MIR200C/MIR141 promoter.

Control of a self-balancing robot with two degrees of freedom via IDA-PBC.

This paper presents an interconnection and damping assignment passivity-based control (IDA-PBC) to drive a self-balancing robot restricted to two degrees of freedom including the dynamics of the actuators. The design of the control law, stability analysis and estimation of the domain of attraction are shown in detail. A convenient change of variables and an appropriate handling of the matching equations have been key to design the control law and to get the asymptotic stability analysis, respectively. Two scalar functions have been used in the design of the controller to underscore how different proposals for the desired potential energy can shape the behavior of the self-balancing robot in closed loop. Experimental results are presented in order to confirm the theoretical proposal and to illustrate the performance of the proposed control law in the regulation task and the practical robustness against external disturbances.

Post-transplant lymphoproliferative disorders after solid organ and hematopoietic stem cell transplantation.

Post-transplant lymphoproliferative disorders (PTLD) are a rare complication after both solid organ (SOT) and allogeneic hematopoietic stem cell transplantation (allo-HSCT). In this single center retrospective study, we compared clinical, biological, and histological features, and outcomes of PTLD after both types of transplant. We identified 82 PTLD (61 after SOT and 21 after allo-HSCT). The presence of B symptoms, Waldeyer ring, spleen, central nervous system, and liver involvement, and advanced Ann-Arbor stage were more frequent in allo-HSCT recipients. PTLD had an earlier onset in allo-HSCT than in SOT cohort (4 vs. 64 months, p < .0001). PTLD was EBV-positive in 100% of allo-HSCT, in contrast to 47% of SOT (p = .0002). Four years after PTLD diagnosis, median overall survival was 32% (95% CI, 22-48) and 10% (95% CI, 2-49) in SOT and allo-HSCT recipients, respectively (p = .002). In conclusion, the clinical presentation and the outcome of PTLD varies greatly depending on the type of transplant.

Relation Between Body Mass Index and Body Image in Spanish and Mexican Adolescents.

This article aims to study the relation between Body Mass Index (BMI) and body image in adolescents from two different social environments in Spain and Mexico, and to compare the construction of an appropriate body scheme in youth from these two countries. The majority of participants were found to be in the normal weight category of BMI. No significant differences were found in BMI or body image comparing Mexican and Spanish adolescents. Regardless of the country of origin, youth belonging to the weight deficit category of BMI overestimated their body shape, whereas those pertaining to overweight and obesity categories underestimated it. Both over- and underestimating own body shape imply higher risk to suffer from behavioral and psychological distresses, such as eating disorders. Further research is recommended in order to analyze the social, educational, and emotional patterns related to this occurrence and to improve their quality of life.

Screening of anthocyanins in single red grapes using a non-destructive method based on the near infrared hyperspectral technology and chemometrics.

BACKGROUND: Anthocyanins are the main compounds responsible for the colour of red wines and therefore it may be important to evaluate the content of the aforesaid secondary metabolites during grape ripening due to the crucial importance to determine wine colour. Nowadays, there is a growing demand of rapid and non-destructive analytical tools for analysing grapes, such as the emerging hyperspectral analysis. RESULTS: The hyperspectral images of intact grapes (Vitis vinifera L. cv. Tempranillo, Graciano, Garnacha and Mazuelo red grape from vineyards located in the D.O.Ca. Rioja at two different developmental stages) were recorded using a near infrared hyperspectral imaging device (900-1700 nm). Reference values of anthocyanins were obtained by HPLC-DAD. Calibrations were performed by modified partial least squares regression and present a good potential (coefficient of determination of 0.72 and standard error of cross-validation values of 0.78 and 0.70 mg per grape for total and non-acylated anthocyanins respectively). CONCLUSION: The procedure reported here presents a good potential for a fast and reasonably inexpensive screening of these compounds in intact single berries. Moreover, the heterogeneity of anthocyanins within the same ripeness stage could be evaluated using this non-detructive tool.

Point prevalence of pressure ulcers in three second-level hospitals in Mexico.

Pressure ulcers (PU) are the source of multiple complications and even death. To our knowledge, there is no available data about PU prevalence in Mexico. The objective of this study was to determine the point prevalence of PU in three second-level hospitals in Mexico. Every adult hospitalised patient was included in each hospital. Age, gender, hospitalisation ward, Braden score, and the number, location and stage of the ulcers encountered were recorded, as well as any pressure relief measures. In total, 294 patients were examined (127 were male); of these, 63 were considered to be at risk. The average age was 48·6 years. The overall prevalence of the PU was 17%. The service with the highest prevalence was the ICU. The most frequent stage was II (32%) and they were most commonly found in the sacrum (74%). The average Braden score of the patients with ulcers was 10, and 21·4% of the patients obtained moderate- to high-risk Braden scores. Of them, 60·3% had ulcers and only 46% had any preventive measures. The prevalence of PU in three hospitals in Mexico is 17%. The most common stage is II and the most commonly affected site is the sacrum. Only 46% of patients with PU had at least one pressure release measure.