Inflammatory bowel disease: The role of commensal microbiome in immune regulation.

The incidence of inflammatory bowel disease (IBD) is increasing. Microbiome is one of the most important factors in its development and affects the different clinical outcomes of IBD patients depending on its composition and different alterations. We conducted a systematic review to discuss the association between microbiome and IBD in terms of immune regulation, and therapies that can modify microbiota. A comprehensive systematic literature search was performed through April 2020 in PubMed, Web of Science, the Cochrane Library, and clinicaltrials.gov. Inclusion criteria required IBD immune regulation and alternate therapeutics for IBD. This analysis helps explain the multifactorial origin of microbiome diversity including normal immune regulation, immune pathophysiology of IBD, and shows the evidence of several therapeutic targets to change microbiome in patients with IBD, such as prebiotics, probiotics, antibiotics, fecal microbiota transplant, and others.

Promising diagnostic biomarkers of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis: From clinical proteomics to microbiome.

Fatty liver has been present in the lives of patients and physicians for almost two centuries. Vast knowledge has been generated regarding its etiology and consequences, although a long path seeking novel and innovative diagnostic biomarkers for nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) is still envisioned. On the one hand, proteomics and lipidomics have emerged as potential noninvasive resources for NAFLD diagnosis. In contrast, metabolomics has been able to distinguish between NAFLD and NASH, even detecting degrees of fibrosis. On the other hand, genetic and epigenetic markers have been useful in monitoring disease progression, eventually functioning as target therapies. Other markers involved in immune dysregulation, oxidative stress, and inflammation are involved in the instauration and evolution of the disease. Finally, the fascinating gut microbiome is significantly involved in NAFLD and NASH. This review presents state-of-the-art biomarkers related to NAFLD and NASH and new promises that could eventually be positioned as diagnostic resources for this disease. As is evident, despite great advances in studying these biomarkers, there is still a long path before they translate into clinical benefits.

A review of Helicobacter pylori diagnosis, treatment, and methods to detect eradication.

Helicobacter pylori (H. pylori) affects nearly half of the world's population and, thus, is one of the most frequent and persistent bacterial infections worldwide. H. pylori is associated with peptic ulcer disease, gastric ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Various diagnostic methods exist to detect infection, and the choice of one method or another depends on several factors, such as accessibility, advantages and disadvantages of each method, cost, and the age of patients. Once H. pylori infection is diagnosed, the clinician decides whether treatment is necessity, according to the patient's clinical condition. Typically, eradication of H. pylori is recommended for treatment and prevention of the infection. Cure rates with the standard triple therapy are acceptable, and effective quadruple therapies, sequential therapies, and concomitant therapies have been introduced as key alternatives to treat H. pylori infection. In this work, we review the main diagnostic methods used to identify H. pylori infection and to confirm eradication of infection. In addition, key factors related to treatment are reviewed.

Prevalence of minimal hepatic encephalopathy in cirrhotic patients.

Background. Minimal hepatic encephalopathy (MHE) has implications for health-related quality of life as well as for survival of cirrhotic patients, but a standardized diagnostic test is not available. Objective. To determine the prevalence of MHE among cirrhotic patients by using the psychometric hepatic encephalopathy score (PHES) system and the critical flicker frequency (CFF) test to diagnose MHE and to identify factors that influence the results of these tests. Material and methods. From April 2007 to March 2008, PHES and CFF tests were performed on patients with cirrhosis but no overt hepatic encephalopathy. Descriptive statistics were used to express the results and the Spearman correlation was used to evaluate CFF and PHES results according to age and education level. Results. We studied 104 patients. The prevalence of MHE was 55.8% (n = 58) based on a positive result for either the PHES or the CFF test, 32.7% (n = 34) based on positive PHES results alone, 34.6% (n = 36) based on positive CFF test results alone and 11.5% (n = 12) based on a positive result for both tests. According to PHES, the incidence of MHE was correlated with education level (r = 0.333, p = 0.001), but not with age. According to CFF, the incidence of MHE was correlated with age (r = -0.93, p = 0.049), but not with education level. Conclusion. The prevalence of MHE was similar to that previously reported. Patient literacy influences MHE diagnosis with PHES but not with CFF. CFF is a simple and feasible method that identifies patients with MHE who may benefit from treatment independently of their education level.

Determination of ammonia concentrations in cirrhosis patients-still confusing after all these years?

By the end of the nineteenth century, ammonia had been identified as the main factor responsible for hepatic encephalopathy syndrome. Ammonia is one of the principal products of hepatic metabolism and high concentrations are toxic to the body. Under physiological conditions, the main way by which the body restricts the blood concentration of ammonia to a nontoxic level is by converting it to urea in the liver via the Krebs cycle. The synthesis of glutamine represents an alternative pathway for ammonia detoxification in cirrhotic patients. Although high concentrations of ammonia have been strongly associated with brain edema, estimates of the strength of the correlation between serum ammonia levels and the severity of hepatic encephalopathy vary. The accuracy of ammonia assays depends on the site of specimen collection, treatment of the specimen and the analytical method used. New methods involving measurement of the partial pressure of ammonia and new noninvasive techniques involving quantification of ammonium in the breath have been described. The purpose of this review is to identify factors that affect serum ammonia levels, from its origin and metabolism to its analysis and interpretation of results in the laboratory. In conclusion, variations in estimates of serum ammonia level and the severity of hepatic encephalopathy arise because of individual differences in ammonia metabolism and differences in the accuracy of analytical methods.

Prevalence of multidrug-resistant bacteria at a tertiary-care teaching hospital in Mexico: special focus on Acinetobacter baumannii.

Our aim was to determine the prevalence of multidrug resistance of Acinetobacter baumannii and other pathogens at a tertiary-care teaching hospital in Mexico over a 3-year period. Clinical isolates of A. baumannii (n = 550), Pseudomonas aeruginosa (n = 250), some Enterobacteriaceae species (n = 500) and Staphylococcus aureus (n = 250) collected over a 3-year period were included. Susceptibility tests were performed by the broth microdilution method. 74% of A. baumannii, 40% of Escherichia coli, 34% of P. aeruginosa, 22% of Klebsiella pneumoniae, 9% of Enterobacter cloacae, and 7% of Serratia sp. were multidrug resistant. 59% of A. baumannii clinical isolates were meropenem-resistant. A. baumannii isolates from the lower respiratory tract were the most susceptible, followed by urine clinical isolates. Species from Enterobacteriaceae showed susceptibility rates higher than 90% to meropenem and tigecycline and Serratia sp. showed the highest susceptibility to the drugs evaluated. For P. aeruginosa, the most potent drug was levofloxacin, followed by meropenem and piperacillin-tazobactam. With regard to S. aureus, 96% of the isolates were susceptible to vancomycin, followed by tigecycline and minocycline (91% of strains susceptible). The high multidrug resistance observed underscores the need for surveillance of bacterial drug resistance.

Hepatitis C virus infection in health-care settings: medical and ethical implications.

Hepatitis C is a major public health issue. It infects about 200 million people worldwide and is a major cause of chronic liver disease. Its transmission in medical facilities is a topic of increased concern, as outbreaks of the disease had raised the attention of media and medical authorities. To date, evidence suggests that infection from in which a health-care worker is involved is mostly result of bad injecting practices as well as the result of shared medical devices. Furthermore, the infection caused by physicians is rare and very few well documented cases exist on the literature. Among countries, different definitions and legislation exist, in that mode that the responsibility of this issue almost is an obligation of individual institutions. Nonetheless, Hepatitis C virus transmission in medical facilities is an important source of new cases, and as treatments options are very limited, it's recommendable that institutions as well as governments implement policies to avoid Hepatitis C spread in a almost fully preventable setting.

mRNA levels of TLR4 and TLR5 are independent of H pylori.

AIM: To determine if the presence H pylori or its virulence affect toll-like receptor 4 (TLR4) and TLR5 mRNA expression levels. METHODS: For the in vivo assays, gastric biopsies were obtained from 40 patients and H pylori status was determined. For the in vitro assays, human gastric adenocarcinoma mucosal cells (AGS) were cultured in the presence or absence of twelve selected H pylori strains. H pylori strains isolated from culture-positive patients and selected strains were genotyped for cagA and vacA. The cDNA was obtained from mRNA extracted from biopsies and from infected AGS cells. TLR4 and TLR5 mRNA levels were examined by real-time PCR. RESULTS: The presence of H pylori did not affect the mRNA levels of TLR4 or TLR5 in gastric biopsies. The mRNA levels of both receptors were not influenced by the vacA status (P > 0.05 for both receptors) and there were no differences in TLR4 or TLR5 mRNA levels among the different clinical presentations/histological findings (P > 0.05). In the in vitro assay, the mRNA levels of TLR4 or TLR5 in AGS cells were not influenced by the vacAs1 status or the clinical condition associated with the strains (P > 0.05 for both TLR4 and TLR5). CONCLUSION: The results of this study show that the mRNA levels of TLR4 and TLR5 in gastric cells, both in vivo and in vitro, are independent of H pylori colonization and suggest that vacA may not be a significant player in the first step of innate immune recognition mediated by TLR4 or TLR5.

Utility of diagnostic tests for detection of Helicobacter pylori in children in northeastern Mexico.

BACKGROUND: The presence of Helicobacter pylori in pediatric population has been associated with recurrent abdominal pain (RAP), although this association is unclear. One of the major problems in studying the role of H. pylori in RAP is that methods used to detect the bacteria in children have poor sensitivity and specificity. The aims of the present study were to determine the prevalence of H. pylori in pediatric patients with RAP in northeastern Mexico and to assess the diagnostic utility of invasive tests and serology in this population. METHODS: A total of 40 patients (mean age, 7.9 years; range 2-16 years; F: M, 0.81), who underwent an endoscopy procedure for RAP, were studied. The presence of H. pylori was assessed using invasive diagnostic tests (culture, rapid urease test, polymerase chain reaction and histology) and one non-invasive test: determination of IgG antibodies. The prevalence of H. pylori in the present group and the diagnostic utility for each test were evaluated. RESULTS: The prevalence of H. pylori in the present pediatric group with RAP was 12.5-42.5% depending on the criteria of positivity used. The non-invasive methods (serology) had acceptable values in sensitivity and specificity in comparison with invasive tests. CONCLUSIONS: This is the first report on prevalence of H. pylori in pediatric patients with RAP from the northeastern region of Mexico. The prevalence of H. pylori was low compared with the adult population in the same geographic region. Serology had the best diagnostic utility.

[How to write a scientific article: how to get your research published]. / Cómo escribir un artículo científico: cómo lograr que su investigación sea publicada.

Into a new and even more competitive profession, doing research and being able to publish it can make a difference. Having the bases for writing a good article, which can efficiently and clearly transmit your discoveries, is essential. We pretend to offer a general guide about what constitutes the content of a publication, and which are the most frequently committed errors. Knowing this can be the difference between being or not published.

[Development of a protocol of pyrosequencing for determination of the polymorphism at position -31 of the interleukin-1beta gene in the study of risk of development of stomach cancer]. / Desarrollo de un protocolo de pirosecuenciación para la tipificación del polimorfismo -31 del gen de la interleucina-1beta en el estudio del riesgo al desarrollo de cáncer gástrico.

BACKGROUND: Single nucleotide polymorphism association studies among cases and controls have been widely used for genetic analysis. The pyrosequencing method is based on indirect luminometric quantification of the pyrophosphate that is released as a result of nucleotide incorporation onto an amplified template. It has the advantages of accuracy, flexibility, automatization and speed when compared with PCR-RFLP method. AIM: To develop a protocol for allele frequency determination using pyrosequencing technology in the detection of the polymorphism at position -31 of the interleukin-1beta (IL-1beta) gene. METHODS: 162 patients (F/M = 0.93) who were enrolled at the Hospital Universitario Dr "José Eleuterio Gonzalez" were studied. 123 patients had non-ulcer dyspepsia and 39 had histologically confirmed gastric cancer (GC). The polymorphism of IL-1beta -31 was determined by both RFLP and pyrosequencing methods. PCR-RFLP method used Alul restriction endonuclease. The same specific primers for PCR-RFLP and pyrosequencing were used for initial amplification and an additional biotinylated specific primer was designed for sequencing. RESULTS: 157 (96.9%) samples were clearly typed by the pyrosequencing method and the results were in accordance with the results of the PCR-RFLP method. The results of 5 samples (3.1%) were not in accordance between both methods. Two of them were T/T and 2 were C/T by sequencing method and all four were C/C by RFLP. Another sample was C/ C by sequencing and T/T by RFLP. CONCLUSION: The pyrosequencing method is not only suitable for the IL-1beta -31 genotyping but is a fast and unexpensive way of genotyping since requires smaller amounts of DNA, and required significantly less time in the generation of results than the RFLP technique. The protocol developed is useful for the typing of the IL-1beta -31 polymorphism.

[C677T polymorphism of the MTHFR gene and the risk of developing distal gastric cancer in a Mexican population]. / Polimorfismo C677T del gen MTHFR y el riesgo al desa- rrollo de cáncer gástrico distal en una población mexicana.

BACKGROUND: The 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C-->T polymorphism has been associated to a higher risk to develop proximal gastric cancer. AIM: To study the role of the MTHFR C677T polymorphism as a risk factor for the development of distal gastric cancer (DGC) in a Mexican population. PATIENTS AND METHODS: Fifty-one histologically confirmed DGC (mean age = 57.6y, F:M = 0.76) and 83 ethnically matched non-GC controls (mean age 51.5y, F:M = 0.59) were studied. The MTHFR C677T polymorphism was typed by PCR-RFLP. The infection by Helicobacter pylori was defined by the positive result of at least two of the next diagnostic tests: histology, rapid urease test and culture. RESULTS: Among the GC patients, 16 (31.4%) were homozygous for C and 23 (45.1%) were CT Among the non-cancer control patients 17 (20.5%) were CC and 49 (59%) were CT. No difference was found in the frequency of the mutated variant MTHFR 677T between the GC cases and the non-cancer control patients (23.5% vs. 20.5 respectively) (p = 0.84; odds ratio: 1.19, 95% confidence interval: 0.48-2.98). The frequency of MTHFR 677TT genotype was not influenced by the infection by H. pylori. CONCLUSION: The mutated genotype TT of the MTHFR is frequent in Mexican population. Our study provides evidence that there is no association between the MTHFR C677T polymorphism and the development of gastric cancer in the Mexican population studied.