Reduction of Helicobacter pylori cells in rural water supply using slow sand filtration.

Helicobacter pylori is a microorganism that infects 60% of the population and is considered the main cause of atrophic gastritis, gastric and duodenal ulcers, and gastric cancer. Different emerging pathogens have been found in drinking water and their presence is considered to be an important public health problem. For this reason, it is necessary to carry out the validation of reliable technologies for this type of pathogens and evaluate their performance. This paper reports, for the first time, H. pylori reduction in a drinking water pilot plant of two slow sand filters (SSF). Inlet water was taken from a gravel filtration system of a rural water supply in Colombia and then inoculated with viable cells of H. pylori. By determining the Genomic Units (GU) through quantitative Polymerase Chain Reaction (qPCR), the concentration of GU/sample was measured. In the inlet water amplification for SSF1 and SSF2 were 5.13 × 102 ± 4.48 × 102 and 6.59 × 102 ± 7.32 × 102, respectively, while for the treated water they were 7.0 ± 5.6 and 2.05 × 101 ± 2.9 × 101 GU/sample for SSF1 and SSF2, respectively. The SSF pilot plant reached up to 3 log reduction units of H. pylori; therefore, since there is not an H. pylori contamination indicator and its periodic monitoring is financially complicated, the SSF could guarantee the drinking water quality necessity that exists in rural areas and small municipalities in developing countries, where infection rates and prevalence of this pathogen are high.

Quantification of the Tissue Oxygenation Delay Induced by Breath-Holding in Patients with Carotid Atherosclerosis.

Carotid artery stenosis (CAS) is a common vascular disease with long-term consequences for the brain. Although CAS is strongly associated with impaired cerebral hemodynamics and neurodegeneration, the mechanisms underlying hemodynamic impairment in the microvasculature remain unknown. In this work, we employed functional near-infrared spectroscopy (fNIRS) to introduce a methodological approach for quantifying the temporal delay of the evoked hemodynamic response. The method was validated during a vasodilatory task (breath-holding) in 50 CAS patients and 20 controls. Our results suggest that the hemodynamic response to breath-holding can be delayed by up to 6 s in the most severe patients, a significant increase from the median 4 s measured for the control group (p = 0.01). In addition, the fraction of brain regions that responded to the task decreased as the CAS severity increased, from a median of 90% in controls to 73% in the most severe CAS group (p = 0.04). The presence of collateral circulation increases the response to breath-holding and decreases the average time delays across the brain, although the number of communicating arteries alone cannot predict these fNIRS-based hemodynamic variables (p > 0.09). Overall, this work proposes a method to quantitatively assess impaired cerebral hemodynamics in CAS patients.

Virulence Genes of Helicobacter pylori Increase the Risk of Premalignant Gastric Lesions in a Colombian Population.

Background: Genetic variability of Helicobacter pylori is associated with various gastrointestinal diseases; however, little is known about interaction with sociodemographic in the development of premalignant lesions in Colombian patients. Methods: An analytical study was conducted including cases (patients with gastric atrophy, intestinal metaplasia, and gastric dysplasia) and controls (patients with nonatrophic gastritis). Sociodemographic information was obtained using a questionnaire. Histopathological diagnosis was performed according to the Sydney System. The cagA and vacA genotypes were established using polymerase chain reaction in paraffin blocks. The effect of each variable on the study outcome (premalignant lesion) is presented as odds ratio (OR) and 95% CI. A p value of <0.05 was considered as statistically significant. Results: The vacA/s1m1 genotype increases the risk of developing premalignant lesions of the stomach (OR: 3.05, 95% IC: 1.57-5.91, p=0.001). Age and educational level showed a positive interaction with the s1m1 genotype (adjusted OR: 3.68, 95% CI: 1.73-7.82, p=0.001). The cagA genotype was not correlated to the development of premalignant lesions of the stomach (OR: 1.32, 95% CI: 0.90-1.94, p=0.151). Conclusions: The vacA genotype, age, and educational level are indicators of the risk of developing premalignant lesions of the stomach in the study population. Significance Statement. Genetic variability of H. pylori and sociodemographic information could be used to predict the risk of premalignant lesions in stomach in Colombian population.

The Effect in Renal Function and Vascular Decongestion in Type 1 Cardiorenal Syndrome Treated with Two Strategies of Diuretics, a Pilot Randomized Trial.

AIM: The main treatment strategy in type 1 cardiorenal syndrome (CRS1) is vascular decongestion. It is probable that sequential blockage of the renal tubule with combined diuretics (CD) will obtain similar benefits compared with stepped-dose furosemide (SF). METHODS: In a pilot double-blind randomized controlled trial of CRS1 patients were allocated in a 1:1 fashion to SF or CD. The SF group received a continuous infusion of furosemide 100 mg during the first day, with daily incremental doses to 200 mg, 300 mg and 400 mg. The CD group received a combination of diuretics, including 4 consecutive days of oral chlorthalidone 50 mg, spironolactone 50 mg and infusion of furosemide 100 mg. The objectives were to assess renal function recovery and variables associated with vascular decongestion. RESULTS: From July 2017 to February 2020, 80 patients were randomized, 40 to the SF and 40 to the CD group. Groups were similar at baseline and had several very high-risk features. Their mean age was 59 ± 14.5 years, there were 37 men (46.2%). The primary endpoint occurred in 20% of the SF group and 15.2% of the DC group (p = 0.49). All secondary and exploratory endpoints were similar between groups. Adverse events occurred frequently (85%) with no differences between groups (p = 0.53). CONCLUSION: In patients with CRS1 and a high risk of resistance to diuretics, the use of CD compared to SF offers the same results in renal recovery, diuresis, vascular decongestion and adverse events, and it can be considered an alternative treatment. ClinicalTrials.gov with number NCT04393493 on 19/05/2020 retrospectively registered.

Nephrologist Interventions to Avoid Kidney Replacement Therapy in Acute Kidney Injury.

BACKGROUND: Based on the pathophysiology of acute kidney injury (AKI), it is plausible that certain early interventions by the nephrologist could influence its trajectory. In this study, we investigated the impact of 5 early nephrology interventions on starting kidney replacement therapy (KRT), AKI progression, and death. METHODS: In a prospective cohort at the Hospital Civil of Guadalajara, we followed up for 10 days AKI patients in whom a nephrology consultation was requested. We analyzed 5 early interventions of the nephrology team (fluid adjustment, nephrotoxic withdrawal, antibiotic dose adjustment, nutritional adjustment, and removal of hyperchloremic solutions) after the propensity score and multivariate analysis for the risk of starting KRT (primary objective), AKI progression to stage 3, and death (secondary objectives). RESULTS: From 2017 to 2020, we analyzed 288 AKI patients. The mean age was 55.3 years, 60.7% were male, AKI KDIGO stage 3 was present in 50.5% of them, sepsis was the main etiology 50.3%, and 72 (25%) patients started KRT. The overall survival was 84.4%. Fluid adjustment was the only intervention associated with a decreased risk for starting KRT (odds ratio [OR]: 0.58, 95% confidence interval [CI]: 0.48-0.70, and p ≤ 0.001) and AKI progression to stage 3 (OR: 0.59, 95% CI: 0.49-0.71, and p ≤ 0.001). Receiving vasopressors and KRT were associated with mortality. None of the interventions studied was associated with reducing the risk of death. CONCLUSIONS: In this prospective cohort study of AKI patients, we found for the first time that early nephrologist intervention and fluid prescription adjustment were associated with lower risk of starting KRT and progression to AKI stage 3.

Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies.

Neurophysiological monitoring is an important goal in the treatment of neurocritical patients, as it may prevent secondary damage and directly impact morbidity and mortality rates. However, there is currently a lack of suitable non-invasive, real-time technologies for continuous monitoring of cerebral physiology at the bedside. Diffuse optical techniques have been proposed as a potential tool for bedside measurements of cerebral blood flow and cerebral oxygenation in case of neurocritical patients. Diffuse optical spectroscopies have been previously explored to monitor patients in several clinical scenarios ranging from neonatal monitoring to cerebrovascular interventions in adults. However, the feasibility of the technique to aid clinicians by providing real-time information at the bedside remains largely unaddressed. Here, we report the translation of a diffuse optical system for continuous real-time monitoring of cerebral blood flow, cerebral oxygenation, and cerebral oxygen metabolism during intensive care. The real-time feature of the instrument could enable treatment strategies based on patient-specific cerebral physiology rather than relying on surrogate metrics, such as arterial blood pressure. By providing real-time information on the cerebral circulation at different time scales with relatively cheap and portable instrumentation, this approach may be especially useful in low-budget hospitals, in remote areas and for monitoring in open fields (e.g., defense and sports).

Integration of Spatial Information Increases Reproducibility in Functional Near-Infrared Spectroscopy.

As functional near-infrared spectroscopy (fNIRS) is developed as a neuroimaging technique and becomes an option to study a variety of populations and tasks, the reproducibility of the fNIRS signal is still subject of debate. By performing test-retest protocols over different functional tasks, several studies agree that the fNIRS signal is reproducible over group analysis, but the inter-subject and within-subject reproducibility is poor. The high variability at the first statistical level is often attributed to global systemic physiology. In the present work, we revisited the reproducibility of the fNIRS signal during a finger-tapping task across multiple sessions on the same and different days. We expanded on previous studies by hypothesizing that the lack of spatial information of the optodes contributes to the low reproducibility in fNIRS, and we incorporated a real-time neuronavigation protocol to provide accurate cortical localization of the optodes. Our proposed approach was validated in 10 healthy volunteers, and our results suggest that the addition of neuronavigation can increase the within-subject reproducibility of the fNIRS data, particularly in the region of interest. Unlike traditional approaches to positioning the optodes, in which low intra-subject reproducibility has been found, we were able to obtain consistent and robust activation of the contralateral primary motor cortex at the intra-subject level using a neuronavigation protocol. Overall, our findings support the hypothesis that at least part of the variability in fNIRS cannot be only attributed to global systemic physiology. The use of neuronavigation to guide probe positioning, as proposed in this work, has impacts to longitudinal protocols performed with fNIRS.

Real-Time Non-invasive Assessment of Cerebral Hemodynamics With Diffuse Optical Spectroscopies in a Neuro Intensive Care Unit: An Observational Case Study.

Prevention of secondary damage is an important goal in the treatment of severe neurological conditions, such as major head trauma or stroke. However, there is currently a lack of non-invasive methods for monitoring cerebral physiology. Diffuse optical methods have been proposed as an inexpensive, non-invasive bedside monitor capable of providing neurophysiology information in neurocritical patients. However, the reliability of the technique to provide accurate longitudinal measurement during the clinical evolution of a patient remains largely unaddressed. Here, we report on the translation of a hybrid diffuse optical system combining frequency domain diffuse optical spectroscopy (FD-DOS) and diffuse correlation spectroscopy (DCS) for real-time monitoring of cerebral physiology in a neuro intensive care unit (neuro-ICU). More specifically, we present a case study of a patient admitted with a high-grade aneurysmal subarachnoid hemorrhage, who was monitored throughout hospitalization. We show that the neurophysiological parameters measured by diffuse optics at the bedside are consistent with the clinical evolution of the patient at all the different stages following its brain lesion. These data provide support for clinical translation of DOS/DCS as a useful biomarker of neurophysiology in the neuro-ICU, particularly in locations where other clinical resources are limited.

Parameter estimation and mathematical modeling of the diffusion process of a benzoic acid infused Fricke gel dosimeter.

This work presents a mathematical model implementation for studying the diffusion process of ferric ions in post-irradiated Fricke gel dosimeters. Fricke gel samples were manufactured in layers for their analysis by optical transmission imaging and benzoic acid was incorporated to improve their radiosensitivity. The developed method consists on designing the dosimeters with a suitable composition for their optical analysis which allows accurate measurements in a wide dose range with noticeable linear responses with an average linear correlation coefficient of r2=0.993. The developed algorithm calculates the diffusion coefficient by means of an inverse problem formulation. Moreover, the proposed method is capable of modeling time-dependent physical properties and evolution over time of the irradiated dosimeters accurately and comparable with experimentally measured data. The obtained results evince the complexity of the diffusion phenomena in this type of materials and the capacity of the proposed method to provide a reliable quantification of the diffusion coefficient as a scalar approximation of the diffusion tensor. The obtained diffusion coefficient varies from 1.21 to 1.61 mm2/h with uncertainties lower than 2%. The model is also transferable to other diffusion driven systems and the numerical solving method can also be adapted to solve diffusion calculation based on other theoretical approaches.

Frecuencia de mutaciones de la nitrorreductasa RdxA de Helicobacter pylori para la activación del metronidazol en una población del departamento del Cauca, Colombia / Frequency of Helicobacter pylori nitroreductase RdxA mutations for metronidazole activation in a population in the Cauca Department, Colombia

RESUMEN Introducción. La resistencia al metronidazol es un factor clave relacionado con el fracaso del tratamiento contra la infección por Helicobacter pylori asociada, principalmente, con mutaciones en la nitrorreductasa RdxA. A pesar de su importancia, los estudios sobre esta proteína son aún incipientes en Popayán, Colombia. Objetivo. Evaluar la frecuencia de las mutaciones en la nitrorreductasa RdxA en una población de pacientes con enfermedad gastrointestinal por H. pylori. Materiales y métodos. El ADN de 170 biopsias gástricas se amplificó mediante reacción en cadena de la polimerasa (PCR) para detectar las mutaciones en la nitrorreductasa RdxA. Se analizaron las secuencias traducidas a aminoácidos y se compararon con la cepa de referencia 26695. Resultados. La frecuencia de mutaciones de la nitrorreductasa RdxA en la población de estudio fue de 78 %. Su distribución más frecuente se detectó en las posiciones D59N (en 153 muestras), R131K (en 101 muestras), R90K (en 97 muestras), A118T (en 42 muestras), I160F (en 32 muestras), H97T (en 26 muestras) y en los codones de parada Q50*; D59*; E75*; C159* y I160* en cinco, una, tres, diez y seis muestras, respectivamente. El genotipo de virulencia más frecuente fue el vacAs1/m1 negativo para cagA (48,6 %). Conclusiones. La gran frecuencia de mutaciones en la nitrorreductasa RdxA en aislamientos de H. pylori en Popayán sugiere que los tratamientos empíricos con metronidazol no serían una opción válida para su erradicación en pacientes de la población estudiada.

ABSTRACT Introduction: Resistance to metronidazole is a key factor associated with Helicobacter pylori treatment failure. Even though resistance is mostly associated with RdxA nitroreductase mutations, studies of this H. pylori protein in Popayán (Colombia) are still incipient. Objective: To evaluate the frequency of mutations in the RdxA nitroreductase in a population of patients with H. pylori-positive gastrointestinal disease. Materials and methods: We amplified the DNA of 170 gastric biopsies by PCR to detect mutations in the RdxA nitroreductase. An analysis of DNA sequences translated into amino acid sequences was done and then compared to the reference strain 26695. Results: The frequency of RdxA nitroreductase mutations in this study population was 78%. Its most frequent distribution was found in positions D59N (153 samples), R131K (101 samples), R90K (97 samples), A118T (42 samples), I160F (32 samples) and H97T (26 samples), and meaningful stop codons Q50*, D59*; E75*, C159* and I160* in five, one, three, ten and six samples, respectively. The most common virulence genotype was vacAs1/m1 cagA negative (48.6 %). Conclusions: The high frequency of RdxA nitroreductase mutations in H. pylori isolates in Popayán (Colombia) indicates that empirical therapy with metronidazole may not be a valid option for the eradication of H. pylori in patients of the studied population.

[Frequency of Helicobacter pylori nitroreductase RdxA mutations for metronidazole activation in a population in the Cauca Department, Colombia].

INTRODUCTION: Resistance to metronidazole is a key factor associated with Helicobacter pylori treatment failure. Even though resistance is mostly associated with RdxA nitroreductase mutations, studies of this H. pylori protein in Popayán (Colombia) are still incipient. OBJECTIVE: To evaluate the frequency of mutations in the RdxA nitroreductase in a population of patients with H. pylori-positive gastrointestinal disease. MATERIALS AND METHODS: We amplified the DNA of 170 gastric biopsies by PCR to detect mutations in the RdxA nitroreductase. An analysis of DNA sequences translated into amino acid sequences was done and then compared to the reference strain 26695. RESULTS: The frequency of RdxA nitroreductase mutations in this study population was 78%. Its most frequent distribution was found in positions D59N (153 samples), R131K (101 samples), R90K (97 samples), A118T (42 samples), I160F (32 samples) and H97T (26 samples), and meaningful stop codons Q50*, D59*; E75*, C159* and I160* in five, one, three, ten and six samples, respectively. The most common virulence genotype was vacAs1/m1 cagA negative (48.6 %). CONCLUSIONS: The high frequency of RdxA nitroreductase mutations in H. pylori isolates in Popayán (Colombia) indicates that empirical therapy with metronidazole may not be a valid option for the eradication of H. pylori in patients of the studied population.

Molecular structure effects on the post irradiation diffusion in polymer gel dosimeters.

Polymer gel dosimeters have specific advantages for recording 3D radiation dose distribution in diagnostic and therapeutic medical applications. But, even in systems where the 3D structure is usually maintained for long periods of time after irradiation, it is still not possible to eliminate the diffusion of the different species in the regions of dose gradients within the gel. As a consequence, information of the dose loses quality over time. In the pursuit of a solution and to improve the understanding of this phenomenon a novel system based on itaconic acid and N-N'-methylene-bisacrylamide (BIS) is hereby proposed. Effects of changes in the chemical structure of the monomers over the dosimetric sensitivity and over the post-irradiation diffusion of species was studied. In this study, one of the carboxylic groups of the itaconic acid molecule was modified with aniline to obtain molecules with similar reactivity but different molecular sizes. Then, dosimeters based on these modified species and on the original ITA molecules were irradiated in an X-ray tomography apparatus at different doses up to 173Gy. Afterwards, the resulting dosimeters were characterized by Raman spectroscopy and optical absorbance in order to study their feasibility and capabilities as dosimetric systems, and by optical-CT to analyze the post irradiation diffusion.

CagA EPIYA polymorphisms in Colombian Helicobacter pylori strains and their influence on disease-associated cellular responses.

AIM: To investigate the influence of the CagA diversity in Helicobacter pylori (H. pylori) strains from Colombia on the host cell biology. METHODS: Eighty-four H. pylori-cagA positive strains with different Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs patterns, isolated from patients with gastritis (n = 17), atrophic gastritis (n = 17), duodenal ulcer (n = 16), intestinal metaplasia (n = 16) and gastric cancer (n = 18), were included. To determine the integrity of the cag pathogenicity island (cagPAI) we evaluated the presence of cagA, cagT, cagE, and cag10 genes by polymerase chain reaction. AGS gastric epithelial cells were infected with each strain and assayed for translocation and tyrosine phosphorylation of CagA by western blot, secretion of interleukin-8 (IL-8) by enzyme-linked immuno sorbent assay after taking supernatants from cocultures and cell elongation induction. For cell elongation quantification, coculture photographs were taken and the proportion of "hummingbird" cells (> 15 µm) was determined. RESULTS: Overall 72% (60/84) of the strains were found to harbor a functional cagPAI. Levels of phosphorylated CagA were significantly higher for isolates from duodenal ulcer than the ones in strains from gastritis, atrophic gastritis, intestinal metaplasia and gastric cancer (49.1% ± 23.1% vs 21.1% ± 19.5%, P < 0.02; 49.1% ± 23.1% vs 26.2% ± 14.8%, P < 0.045; 49.1% ± 23.1% vs 21.5% ± 19.5%, P < 0.043 and 49.1% ± 23.1% vs 29.5% ± 27.1%, P < 0.047 respectively). We observed variable IL-8 expression levels ranging from 0 to 810 pg/mL and from 8.8 to 1442 pg/mL at 6 h and 30 h post-infection, respectively. cagPAI-defective strains did not induce detectable levels of IL-8 at 6 h post-infection. At 30 h post-infection all strains induced IL-8 expression in AGS cells, although cagPAI-defective strains induced significantly lower levels of IL-8 than strains with a functional cagPAI (57.1 ± 56.6 pg/mL vs 513.6 ± 338.6 pg/mL, P < 0.0001). We did not observe differences in the extent of cell elongation induction between strains with a functional or a defective cagPAI in 6 h cocultures. At 24 h post infection strains with functional cagPAI showed high diversity in the extent of hummingbird phenotype induction ranging from 7% to 34%. cagPAI defective strains induced significantly lower levels of elongation than strains with functional cagPAI with one or more than one EPIYA-C motif (15.1% ± 5.2% vs 18.9% ± 4.7%, P < 0.03; and 15.1% ± 5.2% vs 20.0% ± 5.1%, P < 0.003 respectively). No differences were observed in cellular elongation induction or IL-8 expression among H. pylori strains bearing one and more than one EPIYA-C motifs, neither at 6 h nor at 24 h of coculture. There were no associations between the levels of induction of cell elongation or IL-8 expression and number of EPIYA motifs or pathology. CONCLUSION: The present work describes a lack of association between H. pylori CagA protein EPIYA motifs variations from Colombian isolates and disease-associated cellular responses.

Asociación de los polimorfismos IL-1B-511 e IL-1RN y Helicobacter pylori CagA positivo con cáncer gástrico en una zona de riesgo alto en Colombia / Association of interleukin-1 genetic polymorphism and CagA positive Helicobacter pylori with gastric cancer in Colombia

Background: There is an association of interleukin (IL)1B polymorphism with gastric cancer risk. However systematic reviews of the existing evidence have shown that such association varies across populations with different genetic ancestry. Aim: To evaluate the association of IL-1B-511 and IL-1RN polymorphism and Helicobacter pylori IgG antibodies CagA, with gastric cancer in two Colombian cities located in a high risk area for gastric cancer. Material and Methods: A case-control study including 46 gastric cancer cases and 99 controls with non-atrophic gastritis from a high risk zone for gastric cancer. Polymorphism genotyping was carried out by polymerase chain reaction (PCR) and IgG CagA status by ELISA. Results: IgG CagA seropositive individuals had an increased gastric cancer risk (odds ratio (OR) = 11.56; 95 percent confidence intervals (CI) 2.62-50.91 in Tunja and OR = 19.66, 95 percentCI 0.98-395 in Bogotá). IL-1B-511TT carriers in Tunja had increased risk of gastric cancer (OR = 11.31; 95 percentCI 1.20-106.54)), while IL-1RN*2 alelle carriers in Bogotá showed an inverse association with gastric cancer risk (OR = 0.03; 95 percentCI 0.01-0.65). Conclusions: This study adds evidence to the positive association of Helicobacter pylori CagA positive strains with non-cardial gastric cancer etiology. There is a possible heterogeneity in the association of IL-1B gene polymorphism with cancer, in populations of similar ethnic background and settled in the same risk area.

Polimorfismos genéticos de interleucinas IL-1B-511, IL-1RN, IL-10, factor de necrosis tumoral alfa-308 e infección por Helicobacter pylori CagA positivo en cáncer gástrico y úlcera duodenal en diferentes poblaciones en Colombia / Genetic polymorphisms of IL-1B-511, IL-1RN, IL-10 interleukins, tumor necrosis alfa-308 and Positive Helicobacter pylori CagA infection in gastric cancer and duodenal ulcer in different populations in Colombia

Objetivo: Determinar la asociación entre los polimorfismos IL-1B-511, IL-1RN, TNF-α-308, IL-10-819 e IL-101082 y la infección por Helicobacter pylori CagA positivo en un grupo de pacientes con cáncer gástrico y úlcera duodenal en diferentes poblaciones en Colombia. Métodos: Estudio de casos y controles con 341 pacientes: con gastritis no atrófica, 194; con cáncer gástrico, 58; úlcera duodenal con lesiones preneoplásicas, 54; y con úlcera duodenal, 35. La genotipificación de los polimorfismos se hizo por discriminación alélica usando PCR en tiempo real, y la del IL-1RN, por PCR convencional y electroforesis en agarosa. La infección por Helicobacter pylori CagA se determinó mediante ELISA. Se utilizó la regresión logística en el análisis estadístico. Resultados: Ser portador del genotipo IL-1B-511TT (OR=4,69; IC 95% 1,22-18,09) y tener una infección por Helicobacter pylori CagA positivo (OR=4,43; IC 95% 1,72-11,4) se asociaron a cáncer gástrico. Tener una infección por Helicobacter pylori CagA positivo (OR=4,39; IC95% 1,82-10,59) se asoció a la presencia de úlcera duodenal con lesiones preneoplásicas, y ser portador del genotipo IL-1B-511CT se asoció a úlcera duodenal (OR=0,30; IC 95% 0,10-0,91). Conclusión: Los resultados sugieren que la respuesta pro-inflamatoria y la genética virulenta de la bacteria son factores relacionados con los diferentes desenlaces ocasionados por la infección por Helicobacter pylori en la población estudiada; así, el polimorfismo IL-1B-511 es un factor relacionado con cáncer gástrico y úlcera duodenal, y la infección por Helicobacter pylori CagA positivo es un factor asociado a cáncer gástrico y úlcera duodenal con lesiones preneoplásicas.

Objective: To determine the association between the IL-1B-511, IL-1RN, TNF-α-308, IL-10-819 and IL-101082 polymorphisms and positive Heliocobacter pylori CagA infection in a group of patients with gastric cancer and duodenal ulcer in different populations in Colombia. Methods: A case-control study was performed on 341 patients: those with non-atrophic gastritis, 194; with gastric cancer, 58; duodenal ulcer with preneoplastic lesion, 54; and with duodenal ulcer, 35. The genotyping of polymorphisms was done with allelic discrimination using PCR in real time, and that for IL-1RN with conventional PCR and agarose electrophoresis. Helicobacter pylori CagA infection was ascertained with ELISA. Logistic regression was used in statistical analysis. Results: Being a carrier of genotype IL-1B-511TT (OR=4.69; CI 95% 1.22-18.09) and being positive for Helicobacter pylori CagA infection (OR=4.43; CI 95% 1.72-11.4) are associated with gastric cancer. Positive Helicobacter pylori CagA infection (OR=4.39; CI 95% 1.82-10.59) is associated with the presence of duodenal ulcer with preneoplastic lesions, being a carrier of genotype IL-1B-511CT is associated with duodenal ulcer (OR=0.30; CI 95% 0.10-0.91). Conclusion: The results suggest that pro-inflammatory response and virulent bacterial genetics are factors related to the different outcomes brought about by Helicobacter pylori infection in the population studied; that is, the IL-1B-511 polymorphism is a factor related to gastric cancer and duodenal ulcer, and positive Helicobacter pylori CagA infection is a factor associated with gastric cancer and duodenal ulcer with preneoplastic lesions.

[Association of interleukin-1 genetic polymorphism and CagA positive Helicobacter pylori with gastric cancer in Colombia]. / Asociación de los polimorfismos IL-1B-511 e IL-1RN y Helicobacter pylori CagA positivo con cáncer gástrico en una zona de riesgo alto en Colombia.

BACKGROUND: There is an association of interleukin (IL)1B polymorphism with gastric cancer risk. However systematic reviews of the existing evidence have shown that such association varies across populations with different genetic ancestry. AIM: To evaluate the association of IL-1B-511 and IL-1RN polymorphism and Helicobacter pylori IgG antibodies CagA, with gastric cancer in two Colombian cities located in a high risk area for gastric cancer. MATERIAL AND METHODS: A case-control study including 46 gastric cancer cases and 99 controls with non-atrophic gastritis from a high risk zone for gastric cancer. Polymorphism genotyping was carried out by polymerase chain reaction (PCR) and IgG CagA status by ELISA. RESULTS: IgG CagA seropositive individuals had an increased gastric cancer risk (odds ratio (OR) = 11.56; 95% confidence intervals (CI) 2.62-50.91 in Tunja and OR = 19.66, 95%CI 0.98-395 in Bogotá). IL-1B-511TT carriers in Tunja had increased risk of gastric cancer (OR = 11.31; 95%CI 1.20-106.54)), while IL-1RN*2 alelle carriers in Bogotá showed an inverse association with gastric cancer risk (OR = 0.03; 95%CI 0.01-0.65). CONCLUSIONS: This study adds evidence to the positive association of Helicobacter pylori CagA positive strains with non-cardial gastric cancer etiology. There is a possible heterogeneity in the association of IL-1B gene polymorphism with cancer, in populations of similar ethnic background and settled in the same risk area.

Variation in the number of EPIYA-C repeats in CagA protein from Colombian Helicobacter pylori strains and its ability middle to induce hummingbird phenotype in gastric epithelial cells.

INTRODUCTION: Studies using Western Helicobacter pylori strains have shown that a risk factor for gastric cancer is the number of EPIYA-C motifs in the cytotoxin-associated A protein. CagA is delivered into epithelial cells, where it becomes tyrosine phosphorylated in their EPIYA repeats and induces cytoskeleton rearrangements. OBJECTIVES: The objective of this study was to evaluate H. pylori cagA positive strains isolated from Colombian patients with gastroduodenal diseases for the number of EPIYA-C repeats in cagA and their ability to induce cytoskeleton rearrangements in epithelial cells. MATERIALS AND METHODS: We analyzed the 3´ EPIYA repeats region of cagA by PCR in 93 H. pylori cagA positive strains from 49 patients with gastritis, 17 with gastric cancer, and 24 with duodenal ulcer. AGS cells exposed to the various H. pylori isolates were evaluated for rearrangements in their cytoskeleton. RESULTS: Strains with one EPIYA-C were the most frequent in gastritis and duodenal ulcer patients. Strains with three EPIYA-C were mainly found in gastric cancer. We found a significantly higher risk of gastric cancer for individuals infected with strains harboring three EPIYA-C motifs (OR=12.4, CI95%: 2.32-66.3). Strains from gastric cancer showed significantly higher percentages of induction of cytoskeleton rearrangements in comparison with those from gastritis (p Mann-Whitney<0.005). CONCLUSIONS: H. pylori strains with three EPIYA-C repeats can confer an increased risk of cancer to infected individuals.

Helicobacter pylori CagA protein polymorphisms and their lack of association with pathogenesis.

AIM: To investigate Helicobacter pylori (H. pylori) CagA diversity and to evaluate the association between protein polymorphisms and the occurrence of gastric pathologies. METHODS: One hundred and twenty-two clinical isolates of H. pylori cultured from gastric biopsies obtained from Colombian patients with dyspepsia were included as study material. DNA extracted from isolates was used to determine cagA status, amplifying the C-terminal cagA gene region by polymerase chain reaction. One hundred and six strains with a single amplicon were sequenced and results were used to characterize the 3' variable region of the cagA gene. To establish the number and type of tyrosine phosphorylation motifs Glutamine acid-Proline-Isoleucine-Tyrosine-Alanine (EPIYA) bioinformatic analysis using Amino Acid Sequence Analyzer-Amino Acid Sequence Analyzer software was conducted. Analysis of the association between the number of EPIYA motifs and the gastric pathology was performed using chi(2) test and analysis of the presence of EPIYA-C motifs in relation to the pathology was made by logistic regression odds ratios. Comparisons among EPIYA types found and those reported in GenBank were performed using a proportion test in Statistix Analytical Software version 8.0. RESULTS: After amplification of the 3' of the cagA gene, 106 from 122 isolates presented a single amplicon and 16 showed multiple amplicons. As expected, diversity in the size of the cagA unique fragments among isolates was observed. The 106 strains that presented a single amplicon after 3' cagA amplification came from patients with gastritis (19 patients), atrophic gastritis (21), intestinal metaplasia (26), duodenal ulcer (22) and gastric cancer. DNA sequence analysis showed that the differences in size of 3' cagA unique fragments was attributable to the number of EPIYA motifs: 1.9% had two EPIYA motifs, 62.3% had three, 33.0% had four and 2.8% had five motifs. The majority of tested clinical strains (62.3%) were found to harbor the ABC combination of EPIYA motifs and a significant statistical difference was observed between the frequencies of ABCC tyrosine phosphorylation motifs and Western strains sequences deposited in GenBank. CONCLUSION: The present report describes a lack of association between H. pylori CagA-protein polymorphisms and pathogenesis. ABCC high frequency variations compared with Western-strains sequences deposited in GenBank require more investigation.

Variation in the number of EPIYA-C repeats in CagA protein from Colombian Helicobacter pylori strains and its ability to induce hummingbird phenotype in gastric epithelial cells / Variación en el número de repeticiones EPIYA-C en la proteína CagA de aislamientos colombianos de Helicobacter pylori y su capacidad para inducir fenotipo colibrí en células epiteliales gástricas

Introduction. Studies using Western Helicobacter pylori strains have shown that a risk factor for gastric cancer is the number of EPIYA-C motifs in the cytotoxin-associated A protein. CagA is delivered into epithelial cells, where it becomes tyrosine phosphorylated in their EPIYA repeats and induces cytoskeleton rearrangements. Objectives. The objective of this study was to evaluate H. pylori cagA positive strains isolated from Colombian patients with gastroduodenal diseases for the number of EPIYA-C repeats in cagA and their ability to induce cytoskeleton rearrangements in epithelial cells. Materials and methods. We analyzed the 3’ EPIYA repeats region of cagA by PCR in 93 H. pylori cagA positive strains from 49 patients with gastritis, 17 with gastric cancer, and 24 with duodenal ulcer. AGS cells exposed to the various H. pylori isolates were evaluated for rearrangements in their cytoskeleton. Results. Strains with one EPIYA-C were the most frequent in gastritis and duodenal ulcer patients. Strains with three EPIYA-C were mainly found in gastric cancer. We found a significantly higher risk of gastric cancer for individuals infected with strains harboring three EPIYA-C motifs (OR=12.4, CI95%: 2.32-66.3). Strains from gastric cancer showed significantly higher percentages of induction of cytoskeleton rearrangements in comparison with those from gastritis (p Mann-Whitney<0.005). Conclusions. H. pylori strains with three EPIYA-C repeats can confer an increased risk of cancer to infected individuals.

Introducción. En los aislamientos de Helicobacter pylori del hemisferio occidental, se ha observado que el número de repeticiones EPIYA-C en la proteína CagA es un factor de riesgo para cáncer gástrico. La proteína CagA es introducida en la célula epitelial y, posteriormente, es fosforilada en las tirosinas presentes en los motivos EPIYA e induce rearreglos en el citoesqueleto. Objetivos. Nuestro propósito fue evaluar el número de repeticiones EPIYA-C y la habilidad para inducir rearreglos en el citoesqueleto en los aislamientos de H. pylori positivos para cagA, provenientes de pacientes colombianos con enfermedad gastroduodenal. Materiales y métodos. Mediante PCR, se analizó la región 3´ que contiene las repeticiones EPIYA-C, en 93 aislamientos de H. pylori positivos para cagA provenientes de 49 pacientes con gastritis, 17 con cáncer gástrico y 24 con úlcera duodenal. Los rearreglos del citoesqueleto se evaluaron mediante cultivos simultáneos de células AGS con las cepas de H. pylori.Resultados. En gastritis y úlcera duodenal se observó la mayor frecuencia de aislamientos con EPIYA C; los aislamientos con tres repeticiones EPIYA-C se encontraron con mayor frecuencia en cáncer gástrico. Encontramos un riesgo de cáncer gástrico significativamente mayor para individuos infectados con cepas con tres repeticiones EPIYA-C (OR=12,4; IC95% 2,32-66,3). Los aislamientos provenientes de cáncer gástrico mostraron mayores porcentajes de inducción de rearreglos en el citoesqueleto que los observados con aislamientos provenientes de gastritis (prueba de Mann-Whitney menor de 0,005). Conclusiones. La infección con cepas de H. pylori con tres repeticiones EPIYA-C puede conferir un mayor riesgo de desarrollar cáncer gástrico.