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1.
World J Gastroenterol ; 29(15): 2222-2240, 2023 Apr 21.
Article in English | MEDLINE | ID: mdl-37124883

ABSTRACT

Worldwide, gastric cancer (GC) is the fifth most commonly diagnosed malignancy. It has a reduced prevalence but has maintained its poor prognosis being the fourth leading cause of deaths related to cancer. The highest mortality rates occur in Asian and Latin American countries, where cases are usually diagnosed at advanced stages. Overall, GC is viewed as the consequence of a multifactorial process, involving the virulence of the Helicobacter pylori (H. pylori) strains, as well as some environmental factors, dietary habits, and host intrinsic factors. The tumor microenvironment in GC appears to be chronically inflamed which promotes tumor progression and reduces the therapeutic opportunities. It has been suggested that inflammation assessment needs to be measured qualitatively and quantitatively, considering cell-infiltration types, availability of receptors to detect damage and pathogens, and presence or absence of aggressive H. pylori strains. Gastrointestinal epithelial cells express several Toll-like receptors and determine the first defensive line against pathogens, and have been also described as mediators of tumorigenesis. However, other molecules, such as cytokines related to inflammation and innate immunity, including immune checkpoint molecules, interferon-gamma pathway and NETosis have been associated with an increased risk of GC. Therefore, this review will explore innate immune activation in the context of premalignant lesions of the gastric epithelium and established gastric tumors.


Subject(s)
Helicobacter Infections , Helicobacter pylori , Stomach Neoplasms , Humans , Stomach Neoplasms/metabolism , Immunity, Innate , Cytokines/metabolism , Inflammation/metabolism , Toll-Like Receptors/metabolism , Gastric Mucosa/metabolism , Tumor Microenvironment
2.
J Air Waste Manag Assoc ; 55(9): 1289-97, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16259424

ABSTRACT

Environmental agencies are currently in the process of implementing a new air management program, which includes the improvement of fuel quality. In this work, exhaust emissions data and estimated relative risk for various fuels testing in-use vehicles, equipped with three different exhaust emission control technologies, are presented. Aromatics, sulfur, and olefins contents; type of oxygenated compound; and Reid vapor pressure were varied. The aim also includes calculating the ozone (O3) forming potential and a relative cancer risk of emissions from current and formulated gasoline blends in Mexico. The proposed gasoline decreases carbon monoxide, total hydrocarbons (THC), and nitrogen oxides emissions by 18 and 14%, respectively, when compared with gasoline sold in the rest of the country and within ozone nonattainment metropolitan areas in Mexico, respectively.


Subject(s)
Air Pollutants/analysis , Gasoline/analysis , Vehicle Emissions/analysis , Air Pollutants/adverse effects , Air Pollution/prevention & control , Alkenes/analysis , Carbon Monoxide/analysis , Cities , Ethanol/analysis , Humans , Hydrocarbons, Aromatic/analysis , Methyl Ethers/analysis , Mexico , Motor Vehicles/classification , Neoplasms/chemically induced , Nitrogen Oxides/analysis , Ozone/analysis , Risk Assessment , Sulfur/analysis , Vehicle Emissions/adverse effects
3.
Environ Sci Technol ; 39(24): 9715-20, 2005 Dec 15.
Article in English | MEDLINE | ID: mdl-16475357

ABSTRACT

Sulfur oxides are one of the most hazardous atmospheric pollutants since they contribute directly to acid rain formation. Consequently, stringent environmental regulations limit atmospheric SOx emissions, motivating research on efficient ways to reduce them. To supply an alternative to reduce these emissions in fluid catalytic cracking units, this study discloses efficient SOx reducing materials based on calcined MgAlFe hydrotalcite-like compounds (HT's). Thus, HT materials were synthesized by several methods including cerium addition. The adsorption of SO2 was carried out by contacting the calcined solid with a mixture of SO2 (1%) in air at 650 degrees C. It was demonstrated that the isomorphic incorporation of iron increased its reduction capability which was reflected in higher reduction rates and metal sulfate reduction grade at 550 degrees C. Moreover, when cerium was present in the iron-containing materials the saturation rate was improved, because cerium oxide promotes the oxidation of SO2 to SO3. The way cerium is incorporated influences the SO2 adsorption capacity.


Subject(s)
Air Pollution/prevention & control , Aluminum Hydroxide/chemistry , Cerium/chemistry , Magnesium Hydroxide/chemistry , Sulfur Dioxide/isolation & purification , Adsorption , Aluminum/chemistry , Catalysis , Iron/chemistry , Magnesium/chemistry , Microscopy, Electron, Scanning , Oxidation-Reduction , Sulfates/chemistry , Temperature
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