High expression of both desmoplastic stroma and epithelial to mesenchymal transition markers associate with shorter survival in pancreatic ductal adenocarcinoma.

Desmoplastic stroma (DS) and the epithelial-to-mesenchymal transition (EMT) play a key role in pancreatic ductal adenocarcinoma (PDAC) progression. To date, however, the combined expression of DS and EMT markers, and their association with variations in survival within each clinical stage and degree of tumor differentiation is unknown. The purpose of this study was to investigate the association between expression of DS and EMT markers and survival variability in patients diagnosed with PDAC. We examined the expression levels of DS markers alpha smooth muscle actin (α-SMA), fibronectin, and vimentin, and the EMT markers epithelial cell adhesion molecule (EPCAM), pan-cytokeratin, and vimentin, by immunohistochemistry using a tissue microarray of a retrospective cohort of 25 patients with PDAC. The results were examined for association with survival by clinical stage and by degree of tumor differentiation. High DS markers expression -α-SMA, fibronectin, and vimentin- was associated with decreased survival at intermediate and advanced clinical stages (p=0.006-0.03), as well as with both poorly and moderately differentiated tumor grades (p=0.01-0.02). Interestingly, the same pattern was observed for EMT markers, i.e., EPCAM, pan-cytokeratin, and vimentin (p=0.00008-0.03). High expression of DS and EMT markers within each clinical stage and degree of tumor differentiation was associated with lower PDAC survival. Evaluation of these markers may have a prognostic impact on survival time variation in patients with PDAC.

Contribution of APOA5, APOC3, CETP, ABCA1 and SIK3 genetic variants to hypertriglyceridemia development in Mexican HIV-patients receiving antiretroviral therapy.

OBJECTIVE: To investigate the impact of single nucleotide polymorphisms (SNPs) from APOA5, APOC3, CETP, ATP binding cassette transporter A1 and SIK3 genes in the development of hypertriglyceridemia in HIV patients under antiretroviral therapy. MATERIAL AND METHODS: A case-control study was developed. Leukocytic genomic DNA was extracted and genotyping for SNPs rs662799, rs964184, rs5128, rs2854116, rs2854117, rs3764261, rs4149310, rs4149267 and rs139961185 was performed by real time-PCR using TaqMan allelic discrimination assays, in Mexican mestizo patients with HIV infection, with hypertriglyceridemia (>1.7 mmol/L) under antiretroviral therapy. Genetic variants were also investigated in a control group of normolipidemic HIV patients (≤ 1.7 mmol/L). Haplotypes and gene interactions were analyzed. RESULTS: A total of 602 HIV patients were genotyped (316 cases and 286 controls). Age and antiretroviral regimen based on protease inhibitors were associated with hypertriglyceridemia (P = 0.0001 and P = 0.0002. respectively). SNP rs964184 GG genotype in APOA5 gene exhibited the highest association with hypertriglyceridemia risk (OR, 3.2, 95% CI, 1.7-5.8, P = 0.0001); followed by SNP rs139961185 in SIK3 gene (OR = 2.3; (95% CI, 1.1-4.8; P = 0.03 for AA vs. AG genotype; and APOC3 rs5128 GG genotype, (OR, 2.2; 95% CI, 1.1-4.9; P = 0.04) under codominant models. These associations were maintained in the adjusted analysis by age and protease inhibitors based antiretroviral regimens. CONCLUSIONS: This study reveals an association between rs964184 in APOA5; rs5128 in APOC3 and rs139961185 in SIK3 and high triglyceride concentrations in Mexican HIV-patients receiving protease inhibitors. These genetic factors may influence the adverse effects related to antiretroviral therapy.

Molecular Epidemiology and Antimicrobial Resistance of Clostridioides difficile in Hospitalized Patients From Mexico.

Clostridioides difficile is a global public health problem, which is a primary cause of antibiotic-associated diarrhea in humans. The emergence of hypervirulent and antibiotic-resistant strains is associated with the increased incidence and severity of the disease. There are limited studies on genomic characterization of C. difficile in Latin America. We aimed to learn about the molecular epidemiology and antimicrobial resistance in C. difficile strains from adults and children in hospitals of México. We studied 94 C. difficile isolates from seven hospitals in Mexico City from 2014 to 2018. Whole-genome sequencing (WGS) was used to determine the genotype and examine the toxigenic profiles. Susceptibility to antibiotics was determined by E-test. Multilocus sequence typing (MLST) was used to determine allelic profiles. Results identified 20 different sequence types (ST) in the 94 isolates, mostly clade 2 and clade 1. ST1 was predominant in isolates from adult and children. Toxigenic strains comprised 87.2% of the isolates that were combinations of tcdAB and cdtAB (tcdA+/tcdB+/cdtA+/cdtB+, followed by tcdA+/tcdB+/cdtA-/cdtB-, tcdA-/tcdB+/cdtA-/ cdtB-, and tcdA-/tcdB-/cdtA+/cdtB+). Toxin profiles were more diverse in isolates from children. All 94 isolates were susceptible to metronidazole and vancomycin, whereas a considerable number of isolates were resistant to clindamycin, fluroquinolones, rifampicin, meropenem, and linezolid. Multidrug-resistant isolates (≥3 antibiotics) comprised 65% of the isolates. The correlation between resistant genotypes and phenotypes was evaluated by the kappa test. Mutations in rpoB and rpoC showed moderate concordance with resistance to rifampicin and mutations in fusA substantial concordance with fusidic acid resistance. cfrE, a gene recently described in one Mexican isolate, was present in 65% of strains linezolid resistant, all ST1 organisms. WGS is a powerful tool to genotype and characterize virulence and antibiotic susceptibility patterns.

Detection of cytomegalovirus in plasma of patient's HIV by duplex real time PCR / Detección de citomegalovirus en plasma de pacientes con VIH mediante PCR dúplex en tiempo real

BACKGROUND: Cytomegalovirus (CMV) is able to cause serious and even deadly diseases in immunocompromised patients. It is important to have a sensitive, specific and molecular viral tests for its detection, using as targets, key genes for viral replication. The following genes have been used in the molecular detection of CMV: UL122 (replication) and UL83 (most abundant protein of the tegument). OBJECTIVE: Detect and quantify CMV, by real-time duplex PCR, from a minimum amount of plasma. MATERIAL AND METHODS: The UL122 and UL83 genes were amplified with different fluorophores, by real-time duplex PCR. To quantify CMV, curves were generated, starting with DNA-CMV (1.0-0.0000001 ng). RESULTS: The dynamic range of "master" duplex straight had a pendent (m) −3.0, the amplification efficiency was 115.44% plasmas from patients with HIV viral load ≥ 100,000 copies/mL, 11.36% were true positive for CMV and 88.64% had no amplifications or they were outside of the linear range of molecular detection. CONCLUSIONS: This test identified two important CMV genes (UL122 and UL83) in a single reaction (FAM:VIC), viral detection was confirmed from a minimum amount of plasma. This mean a smaller amount of biological sample required and would add a tool to the clinical area, as well as a lower consumption of reagents and materials.

INTRODUCCIÓN: El citomegalovirus (CMV) es capaz de provocar enfermedades graves e incluso mortales en pacientes inmunocomprometidos. Es importante contar con pruebas moleculares de detección viral, sensibles y específicas, utilizando como blanco los genes clave para la replicación viral. En la detección molecular de CMV se han utilizado los genes UL122 (replicación) y UL83 (proteína más abundante del tegumento). OBJETIVO: Detectar y cuantificar el CMV mediante reacción en cadena de la polimerasa (PCR) dúplex en tiempo real, a partir de una mínima cantidad de plasma. MATERIAL Y MÉTODOS: Los genes UL122 y UL83 se amplificaron con diferentes fluoróforos mediante PCR dúplex en tiempo real. Para cuantificar el CMV se generó una recta estándar, a partir de DNA del CMV (1.0-0.0000001 ng). RESULTADOS: El rango dinámico de la «recta maestra¼ tuvo una pendiente (m) de -3.0; la eficiencia de amplificación fue del 115.44%; de los plasmas de pacientes con infección por el virus de la inmunodeficiencia humana (VIH) con una carga viral ≥ 100,000 copias/ml, el 11.36% fueron verdaderos positivos para CMV y el 88.64% no tuvieron amplificaciones o estuvieron fuera del rango lineal de detección molecular. CONCLUSIONES: Esta prueba identificó dos genes importantes del CMV (UL122 y UL83) en una sola reacción (FAM:VIC), y se ratificó la detección viral a partir de una mínima cantidad de plasma. Esto se traduce en una menor cantidad de muestra biológica requerida y sumaría una herramienta al área clínica, así como un menor consumo de reactivos y materiales.

Phenotypic and Genotypic Antibiotic Resistance Patterns in Helicobacter pylori Strains From Ethnically Diverse Population in México.

Helicobacter pylori strains carry a range of mutations in genes that confer antimicrobial resistance and restrict the available options to treat the infection. Latin America is a region that conserve a large number of indigenous communities relatively isolated that practice a traditional medicine without consumption of drugs. We hypothesized that rates of antibiotic resistance are lower in these communities. Recent progress in whole-genome sequencing has allowed the study of drug susceptibility by searching for the known mutations associated with antibiotic resistance. The aim of this work was to study trends of antibiotic resistance over a 20-year period in Mexican H. pylori strains and to compare susceptibility between strains from Mexican mestizos and from indigenous population; we also aimed to learn the prevalence of mutational patterns in genes gyrA, gyrB, rdxA, frxA, rpsU, omp11, dppA, and 23S rRNA and its association with phenotypic tests. Resistance to clarithromycin, metronidazole, amoxicillin and levofloxacin was determined in167 H. pylori isolates by E-test, and the occurrence of mutational patterns in specific genes was determined by whole genome sequencing (WGS). The trend of resistance over 20 years in mestizo isolates showed significant resistant increase for clarithromycin and levofloxacin to frequencies that banned its clinical use. Resistance in H. pylori isolates of native communities was lower for all antibiotics tested. Phenotypic resistance showed good to moderate correlation with genotypic tests. Genetic methods for characterizing antibiotic resistance require further validation in each population.

Erratum: A proposed method for the relative quantification of levels of circulating microRNAs in the plasma of gastric cancer patients.

[This corrects the article DOI: 10.3892/ol.2017.5816.].

A proposed method for the relative quantification of levels of circulating microRNAs in the plasma of gastric cancer patients.

Gastric cancer (GC) is the fifth most common type of malignancy and the third leading cause of cancer-associated mortality worldwide. It is necessary to identify novel methods aimed at improving the early diagnosis and treatment of GC. MicroRNA expression profiles in the plasma of patients with GC have demonstrated a potential use in the opportune diagnosis of this neoplasm. However, there are currently no standardized targets for use in the normalization of microRNA Cq values for different neoplasms. The present study tested two normalization approaches while analyzing plasma derived from patients with GC and non-atrophic gastritis. The first method utilized a panel of small nucleolar RNAs (snoRNAs) and a small nuclear RNA (snRNA) provided by a commercial array. The second normalization approach involved the use of hsa-miR-18a-5p and hsa-miR-29a-3p, which were identified by a stability analysis of the samples being tested. The results revealed that the snoRNAs and snRNA were not expressed in all samples tested. Only the stable microRNAs allowed a narrow distribution of the data and enabled the identification of specific downregulation of hsa-miR-200c-3p and hsa-miR-26b-5p in patients with GC. hsa-miR-200c-3p and hsa-miR-26b-5p have been previously linked to cancer, and a Kyoto Encyclopedia of Genes and Genomes analysis demonstrated that these microRNAs were associated with cell adhesion, cell cycle and cancer pathways.

Elevated Levels of Interferon-γ Are Associated with High Levels of Epstein-Barr Virus Reactivation in Patients with the Intestinal Type of Gastric Cancer.

BACKGROUND: The inflammatory response directed against Helicobacter pylori (HP) is believed to be one of the main triggers of the appearance of gastric lesions and their progression to gastric cancer (GC). Epstein-Barr virus (EBV) has been found responsible for about 10% of all GCs, but the inflammatory response has not been studied in GC patients with evidence of high levels of EBV reactivation. OBJECTIVE: To determine the relationship between inflammation and antibodies against EBV reactivation antigens, HP, and the bacterium virulence factor CagA in patients with GC. METHODS: 127 GC patients, 46 gastritis patients, and 197 healthy subjects were studied. IL-1ß, IL-6, IL-8, IL-10, TNF-α, TGF-ß, MCP-1, and IFN-γ levels were measured in serum or plasma and compared against the antibody titers of VCA-IgG, HP, and the HP virulence factor CagA. Statistical associations were estimated. RESULTS: Significant ORs and positive trends were found between VCA-IgG and IFN-γ, specifically for patients with GC of intestinal type (OR: 6.4, 95% C.I. 1.2-35.4) (p < 0.044). CONCLUSIONS: We confirmed a positive association between a marker of EBV reactivation and intestinal gastric cancer and present evidence of a correlation with elevated serum levels of IFN-γ, but not with the other cytokines.

Human Mesenchymal Stem/Stromal Cells from Umbilical Cord Blood and Placenta Exhibit Similar Capacities to Promote Expansion of Hematopoietic Progenitor Cells In Vitro.

Mesenchymal stem/stromal cells (MSCs) from bone marrow (BM) have been used in coculture systems as a feeder layer for promoting the expansion of hematopoietic progenitor cells (HPCs) for hematopoietic cell transplantation. Because BM has some drawbacks, umbilical cord blood (UCB) and placenta (PL) have been proposed as possible alternative sources of MSCs. However, MSCs from UCB and PL sources have not been compared to determine which of these cell populations has the best capacity of promoting hematopoietic expansion. In this study, MSCs from UCB and PL were cultured under the same conditions to compare their capacities to support the expansion of HPCs in vitro. MSCs were cocultured with CD34+CD38-Lin- HPCs in the presence or absence of early acting cytokines. HPC expansion was analyzed through quantification of colony-forming cells (CFCs), long-term culture-initiating cells (LTC-ICs), and CD34+CD38-Lin- cells. MSCs from UCB and PL have similar capacities to increase HPC expansion, and this capacity is similar to that presented by BM-MSCs. Here, we are the first to determine that MSCs from UCB and PL have similar capacities to promote HPC expansion; however, PL is a better alternative source because MSCs can be obtained from a higher proportion of samples.

[Risk factors related to nosocomial pneumonia in pediatric patients undergoing heart surgery]. / Factores de riesgo para el desarrollo de neumonía nosocomial en pacientes pediátricos sometidos a cirugía cardiovascular.

BACKGROUND: Procalcitonin is a diagnostic marker useful to discern infections and non-infectious complications in heart surgeries. The aim is to describe risk factors related to nosocomial pneumonia and the predictive value of serum procalcitonin in pediatric patients undergoing heart surgery. METHODS: During a year a nested case-control study was carried out in a third level hospital. All patients undergoing open-heart surgery were followed and clinical data searching for pneumonia were registered every day. Blood samples for determination of procalcitonin were taken 48 hours after surgery. Those patients who developed pneumonia based on CDC clinical criteria were defined as cases; and controls were those patients who did not developed pneumonia. RESULTS: 188 patients underwent heart surgery (15 % developed pneumonia). Ninety-seven patients were submitted to open-heart surgery: 24 cases and 73 controls. Seventy-eight % of cases developed pneumonia between second and fifth day after surgery. The average time of surgery, extracorporial bypass, aortic cross-clamp, and mechanical ventilation were greater in control patients. The frequency of open sternotomy, reintubation, and surgical wound infections was greater in case patients. CONCLUSIONS: Some of the events related to heart surgery and their subsequent management are associated significantly to the development of hospital-acquired pneumonia.

Introducción: la procalcitonina (PCT) sirve para discriminar entre infección y complicaciones no infecciosas en cirugías cardiacas. Se busca describir el riesgo de neumonía nosocomial y la utilidad de la PCT en el diagnóstico de pacientes pediátricos sometidos a cirugía cardiovascular. Métodos: estudio de casos y controles anidados en una cohorte. Durante un año a todos los pacientes sometidos a cirugía cardiovascular se les hizo seguimiento diario de sus condiciones clínicas y determinación de PCT a las 48 horas de haber sido intervenidos quirúrgicamente. Se tomaron exclusivamente los pacientes sometidos a circulación extracorpórea: los casos desarrollaron neumonía según los criterios del CDC; los controles, no. Resultados: se intervinieron 188 pacientes. Desarrolló neumonía el 15 %. Fueron sometidos a circulación extracorpórea 97 pacientes, quedando 24 casos y 73 controles. El 78 % de los casos desarrolló proceso neumónico entre el segundo y el quinto día postquirúrgico. La media del tiempo quirúrgico (TQ), circulación extracorpórea (TCE), pinzamiento aórtico (TPA) y ventilación mecánica fueron mayores en los casos (p < 0.001). La frecuencia de esternotomía abierta, reintubación e infección de herida quirúrgica fue más alta en el grupo de casos (p < 0.001). Conclusiones: algunos eventos del proceso quirúrgico cardiovascular y su posterior manejo están significativamente asociados al desarrollo de neumonía nosocomial en niños.

Prevalence of HMTV in breast carcinomas and unaffected tissue from Mexican women.

BACKGROUND: Breast cancer is a complex multifactorial genetic disease. Among other factors, race and, to an even greater extent, viruses are known to influence the development of this heterogeneous disease. It has been reported that MMTV-like (HMTV) gene sequences with a 90 to 98% homology to mouse mammary tumor virus are found in several populations with a prevalence range of 0 to 74%. In the Mexican population, 4.2% of patients with breast cancer exhibit the presence of HMTV (MMTV-like) sequences. The aim of this study was to evaluate the presence and current prevalence of retroviral HMTV (MMTV-like) sequences in breast cancer in Mexican women. METHODS: We used nested PCR and real-time PCR with a TaqMan probe. As a positive control, we used the C3H MMTV strain inserted into pBR322 plasmid. To confirm that we had identified the HMTV sequences, we sequenced the amplicons and compared these sequences with those of MMTV and HMTV (GenBank AF033807 and AF346816). RESULTS: A total of 12.4% of breast tumors were HMTV-positive, and 15.7% of the unaffected tissue samples from 458 patients were HMTV-positive. A total of 8.3% of the patients had both HMTV-positive tumor and adjacent tissues. The HMTV-positive samples presented 98% similarity to the reported HMTV sequence. CONCLUSIONS: These results confirm that the HMTV sequence is present in breast tumors and non-affected tissues in the Mexican population. HMTV should be considered a prominent causative agent of breast cancer.

Preeclampsia is associated with lower production of vascular endothelial growth factor by peripheral blood mononuclear cells.

BACKGROUND: Recent studies show that vascular endothelial growth factor (VEGF) downregulation is implicated in preeclampsia (PE) pathophysiology. This study assessed the relationship between PE and VEGF levels produced by peripheral blood mononuclear cells (PBMCs) and their serum levels. METHODS: A cross-sectional design was performed in 36 patients who had hypertensive disorders during pregnancy. We also used a longitudinal design with 12 pregnant women with risk factors for PE development and/or abnormal uterine arteries by Doppler study. VEGF and soluble fms-like tyrosine kinase-1 (sFlt-1) levels were measured for all patients in both designs. RESULTS: sFlt-1 serum was higher in preeclamptic patients (n = 26), whereas VEGF produced by stimulated PBMCs was lower than in healthy pregnant women and VEGF levels produced by stimulated PBMCs were even lower (p <0.003) in severe PE (n = 16). The receiver-operating characteristic curve analysis allowed establishing a cut-off value to identify patients with PE. VEGF production by PBMCs was 339.87 pg/mL. In addition, a robust linear regression model was performed to adjust the variance in VEGF levels. The patients' age decreased VEGF levels and was adjusted by weeks of gestation (WG) in our model. In the longitudinal study, 7/12 patients developed PE. VEGF produced by PBMCs cells was significantly lower in PE at 24-26 WG. CONCLUSIONS: VEGF production by PBMCs is inhibited during PE, creating a downregulation of the microenvironment; this deficiency may contribute to the pathogenesis of disease.

[Detection of cytomegalovirus by real-time PCR in HIV-positive plasm]. / Detección de citomegalovirus por PCR en tiempo real en plasmas positivos a VIH.

BACKGROUND: Cytomegalovirus is a betaherpesvirus responsible for persistent infections that are generally asymptomatic in healthy individuals. In the absence of an effective immune response, as in neonates, cancer patients, organ transplant recipients, individuals with AIDS, etc., cytomegalovirus may cause severe disease. Early detection of this virus would prevent serious health consequences in immunocompromised patients; it is important to employ sensitive methods and accurate detection to support treatment-related decision making. Real-time molecular methods, such as the polymerase chain reaction, possess higher sensitivity to detect positive samples. METHODS: We compared the sensitivity and specificity of the following detection methods: the endpoint PCR trade-validated method (Pol, viral gene target) and real-time PCR, which detects viral genes Pol (early gene), and pp65 (late gene). We performed a cross-sectional study of 43 human immunodeficiency virus-positive samples. RESULTS: The molecular detection methods in real-time detected a greater number of cytomegalovirus-positive samples than those at the endpoint. CONCLUSIONS: There must be at least two independent cytomegalovirus target-genes in order to make the detection by real-time PCR.

INTRODUCCIÓN: el citomegalovirus es responsable de infecciones persistentes, generalmente asintomáticas en personas sanas pero que en ausencia de una respuesta inmune efectiva puede causar enfermedad severa, por ello es muy importante su detección temprana en los individuos con trastornos de la inmunidad. El objetivo de esta investigación fue hacer un análisis del límite de detección, sensibilidad y concordancia de la reacción en cadena de la polimerasa (PCR) en punto final con los obtenidos con la PCR en tiempo real. MÉTODOS: se realizó un estudio transversal con 43 muestras de plasma humano positivas al virus de la inmunodeficiencia humano, provenientes de individuos de 18 o más años de edad, de uno u otro sexo. Todas las muestras tuvieron una carga viral-VIH mayor a 100 000 copias/mL. Para la PCR en punto final se empleó un método comercial para identificar UL54 (gen viral blanco) y para la PCR en tiempo real se amplificaron fragmentos de los genes UL54 (gen temprano) y UL83 (gen tardío) del citomegalovirus humano. RESULTADOS: mediante PCR en punto final (método comercial-validado) solo tres individuos fueron positivos a citomegalovirus humano (7 %), con una la carga viral de 1500 a 1670 copias/mL. Las muestras positivas a citomegalovirus humano mediante PCR en tiempo real tuvieron un rango de 4.36 a 4692.86 copias de citomegalovirus humano CONCLUSIONES: es necesario tener al menos dos genes blancos de citomegalovirus humano para detectarlo de manera ratificada mediante PCR en tiempo real.

La investigación sobre calidad de la atención en el Instituto Mexicano del Seguro Social: estudio bibliométrico / Research on quality of health care from the Mexican Social Security Institute: a bibliometric study

Objetivo. Identificar las investigaciones sobre calidad de la atención en el IMSS. Material y métodos. Estudio bibliométrico, transversal, retrospectivo y descriptivo, sobre las publicaciones del IMSS de 1992 a 2011. Resultados. Se identificaron 881 investigaciones sobre calidad de la atención (11% IC95% 10.6-12.0) de 7 762 trabajos. Se publicaron 946 artículos (8.9% IC95% 8.4-9.5) relacionados con la calidad. Conclusiones. Se identificó interés en realizar investigación sobre calidad del servicio. Habrá que establecer cuál ha sido el impacto en la mejora de la atención, y su contribución a la toma de decisiones en materia de salud.

Objective. To identify studies on quality of health care in the IMSS. Materials and methods. A bibliometric, descriptive cross-sectional and retrospective study was conducted, from 1992 to 2011. Results. We identified 881 research studies related to the issue of quality (CI95% 10.6-12.0) of 7 762 studies presented at the annual research meetings. 10 521 articles were published in this period of time and only 946 (CI95% 8.4-9.5) were linked to the issue of quality. Conclusions. The results of this study allowed us to identify the interest about research on quality. Further research is needed to establish what has been the impact on the improvement of quality in health care.

Epstein Barr virus and Helicobacter pylori co-infection are positively associated with severe gastritis in pediatric patients.

BACKGROUND: H. pylori infection is acquired during childhood and causes a chronic inflammatory response in the gastric mucosa, which is considered the main risk factor to acquire gastric cancer (GC) later in life. More recently, infection by Epstein-Barr virus (EBV) have also been associated with GC. The role of EBV in early inflammatory responses and its relationship with H. pylori infection remains poorly studied. Here, we assessed whether EBV infection in children correlated with the stage of gastritis and whether co-infection with H. pylori affected the severity of inflammation. METHODOLOGY/PRINCIPAL FINDINGS: 333 pediatric patients with chronic abdominal pain were studied. From them, gastric biopsies were taken and inflammation graded according to the Sydney system; peripheral blood was drawn and antibodies against EBV (IgG and IgM anti-VCA) and H. pylori (IgG anti-whole bacteria and anti-CagA) were measured in sera. We found that children infected only by EBV presented mild mononuclear (MN) and none polymorphonuclear (PMN) cell infiltration, while those infected by H. pylori presented moderate MN and mild PMN. In contrast, patients co-infected with both pathogens were significantly associated with severe gastritis. Importantly, co-infection of H. pylori CagA+/EBV+ had a stronger association with severe MN (PR 3.0) and PMN (PR 7.2) cells than cases with single H. pylori CagA+ infection. CONCLUSIONS/SIGNIFICANCE: Co-infection with EBV and H. pylori in pediatric patients is associated with severe gastritis. Even single infections with H. pylori CagA+ strains are associated with mild to moderate infiltration arguing for a cooperative effect of H. pylori and EBV in the gastric mucosa and revealing a critical role for EBV previously un-appreciated. This study points out the need to study both pathogens to understand the mechanism behind severe damage of the gastric mucosa, which could identified children with increased risk to present more serious lesions later in life.

Is human cytomegalovirus associated with breast cancer progression?

BACKGROUND: It has been hypothesized that human cytomegalovirus (HCMV) may be associated with breast cancer progression. However, the role of HCMV infection in breast cancer remains controversial. We aimed to assess whether HCMV genes (UL122 and UL83) could be detected in breast carcinomas and reinvestigated their possible association with breast cancer progression. DNA from paraffin-embedded tissues was analyzed by real-time PCR. We investigated 20 fibroadenomas and 27 primary breast carcinomas (stages II, III, and IV). FINDINGS: Two carcinomas were positive for HCMV, one was positive for two TaqMan viral detection probes, and one was positive for a sole TaqMan viral detection probe (UL83), whereas the remainder of the samples was negative. CONCLUSIONS: Samples studied showed no association between HCMV infection and breast cancer progression.

[Research on quality of health care from the Mexican Social Security Institute: a bibliometric study]. / La investigación sobre calidad de la atención en el Instituto Mexicano del Seguro Social: estudio bibliométrico.

OBJECTIVE. To identify studies on quality of health care in the IMSS. MATERIALS AND METHODS. A bibliometric, descriptive cross-sectional and retrospective study was conducted, from 1992 to 2011. RESULTS. We identified 881 research studies related to the issue of quality (CI95% 10.6-12.0) of 7 762 studies presented at the annual research meetings. 10 521 articles were published in this period of time and only 946 (CI95% 8.4-9.5) were linked to the issue of quality. CONCLUSIONS. The results of this study allowed us to identify the interest about research on quality. Further research is needed to establish what has been the impact on the improvement of quality in health care.

Correction: Epstein Barr Virus and Helicobacter pylori Co-Infection Are Positively Associated with Severe Gastritis in Pediatric Patients.

[This corrects the article DOI: 10.1371/journal.pone.0062850.].

Use of dried blood samples for monitoring hepatitis B virus infection.

BACKGROUND: Hepatitis B virus (HBV) infection is a problem in several regions of the world with limited resources. Blood samples dried on filter paper (DBS) have been successfully used to diagnose and monitor several infectious diseases. In Mexico there is an urgent need for an affordable and easy sampling method for viral load (VL) testing and monitoring of chronic HBV infection. The purpose of this work was to validate the utility of DBS samples for monitoring HBV infection in patients from Mexico City. METHODS: Matched samples of plasma and DBS on filter paper from 47 HBV infected patients from the Instituto Mexicano del Seguro Social (IMSS), were included. To evaluate the DNA stability and purity from DBS stored at different temperature conditions, samples from ten patients were stored at 4 degree, 25 degree, and 37 degree C for 7 days. After DBS elution and DNA extraction, the purity of these samples was determined measuring the O.D. rate 260/280. The DBS utility for molecular studies was assessed with PCR assays to amplify a 322 bp fragment from the "a" determinant region of the HBV "S" gene. The VL from all samples was determined to evaluate the correlation between plasma and DBS matched samples. RESULTS: The quality of the DNA from DBS specimen is not adversely affected by storage at 4 degree, 25 degree and 37 degree C for up 7 days. Statistical ANOVA analyses did not show any significant difference. The same amplification efficiency was observed between DNA templates from samples stored at different temperatures. The Pearson correlation between the VL from DBS and plasma matched samples was 0.93 (p = 0.01). The SD was 1.48 for DBS vs.1.32 for Plasma, and an average of log10 copies/mL of 5.32 vs. 5.53. ANOVA analysis did not show any statistically significant difference between the analyzed groups (p = 0.92). CONCLUSION: The results provide strong evidence that the isolation and quantification of DNA-HBV from DBS is a viable alternative for patient monitoring, and molecular characterization of the virus variants circulating in Mexico.

Seroepidemiology of giardiasis in Mexico.

Prevalence of antibodies against Giardia duodenalis was determined by enzyme-linked immunosorbent assay in serum samples from a national serologic survey of Mexico that included all geographic areas and socioeconomic and demographic data for each person sampled. The country was divided into four regions on the basis of development (high, medium high, medium low, and low). Of 3,461 serum samples tested, 1,914 (55.3%) were positive for IgG antibodies against Giardia duodenalis. Seropositivity was age-specific; the probability of seropositivity increased 4.9-fold (95% confidence interval [CI] = 3.16-7.64) in adolescents 10-19 years of age, 8.0-fold (95% CI = 5.19-12.53) in young adults 20-39 years of age, and 12.6-fold (95% CI = 7.93-20.28) in adults more than 40 years of age. Giardia duodenalis seropositivity was associated with male sex (odds ratio = 1.40, 95% CI = 1.22-1.61). No association was found between seropositivity and socioeconomic variables or regional development status.