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Role of dup A in virulence of Helicobacter pylori

World Journal of Gastroenterology 2016年第46期22卷 10118-10123页

作者： Amin Talebi Bezmin Abadi guillermo perez-perez Department of Bacteriology Faculty of Medical Sciences Tarbiat Modares University Departments of Medicine and Microbiology New York University School of Medicine and VA Medical Center

Helicobacter pylori(H. pylori) is a gastric human pathogen associated with acute and chronic gastritis, 70% of all gastric ulcers, 85% of all duodenal ulcers, and both forms of stomach cancer, mucosal-associated lymphoid tissue(MALT) lymphoma and adenocarcinoma. Recently, attention has focused on possible relationship between presence of certain virulence factor and H. pylori-associated diseases. Some contradictory data between this bacterium and related disorders has been observed since not all the colonized individuals develop to severe disease. The reported diseases plausibility related to H. pylori specific virulence factors became an interesting story about this organism. Although a number of putative virulence factors have been identified including cytotoxin-associated gene a(cag A) and vac A, there are conflicting data about their actual participation as specific risk factor for H. pylori-related diseases. Duodenal ulcer promoting gene a(dup A) is a virulence factor of H. pylori that is highly associated with duodenal ulcer development and reduced risk of gastric cancer. The prevalence of dup A in H. pylori strains isolated from western countries is relatively higher than in H. pylori strains from Asian countries. Current confusing epidemiological reports will continue unless future sophisticated and molecular studies provide data on functional and complete dup A cluster in H. pylori infected individuals. This paper elucidates available knowledge concerning role of dup A in virulence of H. pylori after a decade of its discovery.

关键词： Helicobacter pylori dup A Bacterial virulence infection Clinical outcome

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Synthesis of hydroxymethylfurfural and furfural from hardwood and softwood pulp using ferric sulphate as catalyst

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Frontiers of Chemical Science and Engineering 2019年第3期13卷 531-542页

作者： Agneev Mukherjee guillermo Portillo-perez Marie-Josee Dumont Bioresource Engineering Department McGill UniversityQC H9X 3V9Canada

Hydroxymethylfurfural (HMF) and furfural are promising chemicals for the creation of a bio-based economy. The development of an inexpensive catalytic system for converting cellulosic biomass into these chemicals is an important step in this regard. Ferric sulphate is a common, cheap and non-toxic Lewis acid that has been used to catalyse reactions such as wood depolymerisation. In this work, ferric sulphate was used to help the production of HMF and furfural from hardwood and softwood pulps. It was found that for hardwood pulp, the use of ferric sulphate alone gave a maximum HMF yield of 31.6 mol-%. The addition of the ionic liquid [BMIM]Cl or HCl as co-catalysts did not lead to an increase in the yields obtained. A prior decationisation step, however, resulted in HMF yields of 50.4 mol-%. Softwood pulp was harder to depolymerise than hardwood, with a yield of 28.7% obtained using ferric sulphate alone. The maximum HMF yield from softwood, 37.9 mol-%, was obtained using a combination of ferric sulphate and dilute HCl. It was thus concluded that ferric sulphate is a promising catalyst for HMF synthesis from cellulosic biomass.

关键词： 5-hydroxymethylftirfural hardwood softwood ferric sulphate biorefinery

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Memory for location and visual cues in white-eared hummingbirds Hylocharis leucotis

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Current Zoology 2011年第4期57卷 468-476页

作者： guillermo perez Carlos LARA Jose VICCON-PALE Martha SIGNORET-POILLON Doctorado en Ciencias Biologicas Universidad Autonoma Metropolitana. Unidad Xochimilco. Calzada del Hueso 1100 Col. Villa Quietud 04960 Moxico D.F. Moxico Laboratorio de Ecologfa de la Conducta Centro Tlaxcala de Biologfa de la Conducta UAT-UNAM Km 1.5 carretera Tlaxcala- Puebla s/n Colonia Xicohtoncatl Apdo. Postal 262 Tlaxcala Tlaxcala 90070 Moxico. Departamento el Hombre y su Ambiente. Universidad Autdnoma Metropolitana. Unidad Xochimilco. Calzada del Hueso 1100 Col. Villa Quietud 04960 MExico D.F. Mexico

In nature hummingbirds face floral resources whose availability, quality and quantity can vary spatially and temporally. Thus, they must constantly make foraging decisions about which patches, plants and flowers to visit, partly as a function of the nectar reward. The uncertainty of these decisions would possibly be reduced if an individual could remember locations or use visual cues to avoid revisiting recently depleted flowers. In the present study, we carried out field experiments with white-eared hummingbirds Hylocharis leucotis, to evaluate their use of locations or visual cues when foraging on natural flowers Penstemon roseus. We evaluated the use of spatial memory by observing birds while they were foraging between two plants and within a single plant. Our results showed that hummingbirds prefer to use location when foraging in two plants, but they also use visual cues to efficiently locate unvisited rewarded flowers when they feed on a single plant. However, in absence of visual cues, in both experiments birds mainly used the location of previously visited flowers to make subsequent visits. Our data suggest that hummingbirds are capable of learning and employing this flexibility depending on the faced environmental conditions and the information acquired in previous visits [Current Zoology 57 （4）： 468-476, 2011].

关键词： Visual cues Location White-eared hummingbird Foraging

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

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World Journal of Gastroenterology 2014年第6期20卷 1438-1449页

作者： Elvira Garza-González guillermo igna.io perez-perez Héctor Jesús Maldonado-Garza Francisco Javier Bosques-Padilla Servicio de Gastroenterología y Departamento de Patología Clínica Hospital Universitario "Dr. José Eleuterio González" Universidad Autónoma de Nuevo León Departments of Medicine and Microbiology New York University School of Medicine

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.

关键词： Diagnosis Helicobacter pylori Treatment Hybrid therapy Concomitant therapy Sequential therapy

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Precision silviculture:use of UAVs and comparison of deep learning models for the identification and segmentation of tree crowns in pine crops

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International Journal of Digital Earth 2022年第1期15卷 2223-2238页

作者： Manuel igna.io perez Bruno Karelovic Roberto Molina Rodrigo Saavedra Pierluigi Cerulo guillermo Cabrera Department of Computer Sciences Universidad de Concepcion Biblioteca CentralConcepcionChile Celulosa Arauco y Constitucion SA I&DSantiagoChile

The monitoring of trees is crucial for the management of large areas of forest cultivations,but this process may be ***,remotely sensed data offers a solution to automate this *** this work,we used two neural network methods named You Only Look Once(YOLO)and Mask R-CNN to overcome the challenging tasks of counting,detecting,and segmenting high dimensional Red–Green–Blue(RGB)images taken from unmanned aerial vehicles(UAVs).We present a processing framework,which is suitable to generate accurate predictions for the aforementioned tasks using a reasonable amount of labeled *** compared our method using forest stands of different ages and *** counting,YOLO overestimates 8.5%of the detected trees on average,whereas Mask R-CNN overestimates a 4.7%of the *** the detection task,YOLO obtains a precision of 0.72 and a recall of 0.68 on average,while Mask R-CNN obtains a precision of 0.82 and a recall of *** segmentation,YOLO overestimates a 13.5%of the predicted area on average,whereas Mask R-CNN overestimates a 9.2%.The proposed methods present a cost-effective solution for forest monitoring using RGB images and have been successfully used to monitor∼146,500 acres of pine cultivations.

关键词： Artificial intelligence tree identification forestry remote sensing

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mRNA levels of TLR4 and TLR5 are independent of H pylori

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World Journal of Gastroenterology 2008年第34期14卷 5306-5310页

作者： Elvira Garza-González Virgilio Bocanegra-García Francisco Javier Bosques-Padilla Juan Pablo Flores-Gutiérrez Francisco Moreno guillermo igna.io perez-perez Departmento de Microbiología Facultad de MedicinaUniversidad Autónoma de Nuevo León Departmento de Biología Molecular y Bioingeniería UAM Reynosa Aztlán Universidad Autónoma de Tamaulipas Hospital Universitario "Dr. José Eleuterio González" Universidad Autónoma de Nuevo León Department of Medicine and Microbiology New York University School of Medicine

AIM:To determine if the presence H pylori or its viru- lence 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) andthere were no differences in TLR4 or TLR5 mRNA levels among the different clinical presentations/histological fi ndings (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 as-sociated 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.

关键词： H pylori Toll-like receptor 4 Toll-likereceptor 5 AGS cells mRNA

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Factors associated with H pylori epidemiology in symptomatic children in Buenos Aires,Argentina

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World Journal of Gastroenterology 2006年第33期12卷 5384-5388页

作者： Cinthia Goldman Andrés Barrado Mariana Janjetic Norma Balcarce Eduardo Cueto Rua Masaru Oshiro María L Calcagno Margarita Martinez Sarrasague Julián Fuda Ricardo Weill Marcela Zubillaga guillermo I perez-perez José Boccio Radioisotopes Laboratory and Laboratory of Stable Isotopes Applied to Biology and Medicine Physics Department School of Pharmacy and Biochemistry University of Buenos Aires Buenos Aires Argentina Laboratory of Stable Isotopes Applied to Biology and Medicine Physics Department School of Pharmacy and Biochemistry University of Buenos Aires Buenos Aires Argentina Gastroenterology Unit Hospital de nios "Superiora Sor María Ludovica" La Plata Argentina Health Center Di Matteo San Fernando Buenos Aires Argentina Mathematics Department School of Pharmacy and Biochemistry University of Buenos Aires Buenos Aires Argentina Agrarian Industries Department School of Agronomy University of Morón Buenos Aires Argentina Departments of Medicine and Microbiology New York University School of Medicine New York United States

AIM： To determine prevalence of H pylori infection in symptomatic children in Buenos Aires, Argentina, and to investigate factors associated with HpyloH positivity. METHODS： A total of 395 children with upper gastrointestinal symptoms referred to the Gastroenterology Unit of the Children Hospital ＂Sor Maria Ludovica＂ were evaluated for the presence of H py/or/by the ^13C-Urea Breath Test （^13C-UBT）. A questionnaire was applied to the recruited population. RESULTS： Prevalence of H pylo H infection was 40.0% in this population （mean age 9.97 ± 3.1 years）. The factors associated with H py/or/positivity were number of siblings （P 〈 0.001）, presence of pet cats （P = 0.03） and birds （P = 0.04） in the household, and antecedents of gastritis among family members （P = 0.01）. After multivariate analysis, number of siblings [Odds ratio （OR） = 1.39; 95% CI, 1.20-1.61] and contact with pet cats （OR = 1.76; 95% CI, 1.00-3.09） remained as variables associated with H pylori infection. CONCLUSioN： The prevalence of H pylori infection in children with upper gastrointestinal symptoms in Argentina was similar to that reported in developed countries. Children from families with a higher crowding index and presence of pet cats have a higher risk of being colonized with Hpylori.

关键词： H pylori Children Epidemiology Urea breathtest Prevalence

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Progress in Use of Natural Products and Their Active Components against Helicobacter pylori

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Advances in Microbiology 2016年第14期6卷 1091-1129页

作者： Alejandro Venegas Jorge Hantar Touma Jessica Bravo guillermo perez-perez Centro de Investigación Biomédica Facultad de Medicina Universidad Diego Portales Santiago Chile Departments of Medicine and Microbiology New York Langone Medical Center NYU New York USA

Helicobacter pylori is considered the main etiological agent of gastritis, ulcers, and gastric carcinoma. It colonizes human gastric mucosa quite efficiently. Fifty % of the world population is actually infected. Since H. pylori discovery in 1982, it is well known the sensitivity of several H. pylori strains to a number of antibiotics when these are assayed in vitro. However, eradication therapies with a single antibacterial agent have failed. Recently, triple, quadruple, sequential, concomitant and hybrid therapies which include antibiotics and a proton pump inhibitor show improved eradication rate and low side effects. However, new problems have emerged. Antimicrobial resistance to the common antibiotics used has become a problem in both developed and developing countries. In particular, H. pylori clarithromycin- and metronidazole-resistant strains are a major problem in countries where H. pylori is highly prevalent. Thus, the widespread use of antibiotics is not economically feasible and might increase difficulties in the treatment of H. pylori. At present, there are no vaccines available in the market. As an alternative, effective non-antibiotic compounds should be highly desirable since their use may be safer and suitable to eradicate H. pylori. The first step in this direction has been to study the effect of medicinal herbs and natural products, such as green tea, ginseng, garlic, propolis, and probiotics, then identify their active components such as polyphenols, antioxidants, purify them, and finally test them using in vitro and in vivo H. pylori growth assays. Some of them have been quite effective. The topics related to alternative therapies for H. pylori infections and current status of their use will be discussed in the present review.

关键词： H. pylori Growth Inhibition Natural Products Herb Infusions Phytochemicals

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Analysis of the postoperative hemostatic profile of colorectal cancer patients subjected to liver metastasis resection surgery

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World Journal of Clinical Cases 2019年第17期7卷 2477-2486页

作者： guillermo perez Navarro Ana Maria Pascual Bellosta Sonia María Ortega Lucea Mario Serradilla Martín Jose Manuel Ramirez Rodriguez Javier Martinez Ubieto Department of Anesthesiology University Hospital Miguel ServetZaragoza 50009Spain Department of General Surgery University Hospital Miguel ServetZaragoza 50009Spain Department of General Surgery University Hospital Lozano BlesaZaragoza 50009Spain

BACKGROUND Liver resection surgery has advanced greatly in recent years,and the adoption of fasttrack programs has yielded good *** anesthesia (general anesthesia associated to epidural analgesia) is an anesthetic-analgesic strategy commonly used for the perioperative management of patients undergoing surgery of this kind,though there is controversy regarding the coagulation alterations it may cause and which can favor the development of spinal *** To study the postoperative course of liver resection surgery,an analysis was made of the outcomes of liver resection surgery due to colorectal cancer metastases in our centre in terms of morbiditymortality and hospital stay according to the anesthetic technique used (general vs combination anesthesia).METHODS A prospective study was made of 61 colorectal cancer patients undergoing surgery due to liver metastases under general and combination anesthesia between January 2014 and October *** patient characteristics,intraoperative variables,postoperative complications,evolution of hemostatic parameters,and stay in intensive care and in hospital were *** A total of 61 patients were included in two homogeneous groups: general anesthesia (n = 30) and combination anesthesia (general anesthesia associated to epidural analgesia)(n = 31).All patients had normal coagulation values before *** international normalized ratio (INR) in both the general and combination anesthesia groups reached maximum values at 2448 h (mean 1.37 and 1.45 vs 1.39 and 1.41,respectively),followed by a gradual *** was less intraoperative bleeding in the combination anesthesia group (769 mL) than in the general anesthesia group (1200 mL)(P ion vs 6.6% in the combination anesthesia group (P < 0.001).The time to gastrointestinal tolerance was significantly correlated to the type of anesthesia,though

关键词： Hepatectomy Epidural analgesia Perioperative complications Epidural hematoma Multimodal rehabilitation Outcomes

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Immunotherapy and immunoescape in colorectal cancer

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World Journal of Gastroenterology 2007年第44期13卷 5822-5831页

作者： guillermo Mazzolini Oihana Murillo Catalina Atorrasagasti Juan Dubrot Iigo Tirapu Miguel Rizzo Ainhoa Arina Carlos Alfaro Arantza Azpilicueta Carmen Berasain José L perez-Gracia Alvaro Gonzalez igna.io Melero Liver Unit Facultad de Ciencias Biomédicas Universidad Austral Presidente Perón 1500 (1635) Derqui-Pilar Buenos Aires Argentina Centro de Investigación Médica Aplicada and Clínica Universitaria Universidad de Navarra Pamplona Spain

Immunotherapy encompasses a variety of interventions and techniques with the common goal of eliciting tumor cell destructive immune responses. Colorectal carcinoma often presents as metastatic disease that impedes curative surgery. Novel strategies such as active immunization with dendritic cells (DCs), gene transfer of cytokines into tumor cells or administration of immunostimulatory monoclonal antibodies (such as anti-CD137 or anti-CTLA-4) have been assessed in preclinical studies and are at an early clinical development stage. Importantly, there is accumulating evidence that chemotherapy and immunotherapy can be combined in the treatment of some cases with colorectal cancer, with synergistic potentiation as a result of antigens cross-presented by dendritic cells and/or elimination of competitor or suppressive T lymphocyte populations (regulatory T-cells). However, genetic and epigenetic unstable carcinoma cells frequently evolve mechanisms of immunoevasion that are the result of either loss of antigen presentation, or an active expression of immunosuppressive substances. Some of these actively immunosuppressive mechanisms are inducible by cytokines that signify the arrival of an effector immune response. For example, induction of 2, 3 indoleamine dioxygenase (IDO) by IFNγ in colorectal carcinoma cells. Combinational and balanced strategies fostering antigen presentation, T-cell costimulation and interference with immune regulatory mechanisms will probably take the stage in translational research in the treatment of colorectal carcinoma.

关键词： Colorectal carcinoma Immunotherapy Gene therapy interleukin-12 Dendritic cells CD137 indoleamine 2, 3 dioxygenase

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