Chronic exposure to cigarette smoke is the leading cause of human lung cancer and its most prevalent form, adenocarcinoma. However, the mechanisms by which smoking induces adenocarcinoma are largely inferred from the ...Chronic exposure to cigarette smoke is the leading cause of human lung cancer and its most prevalent form, adenocarcinoma. However, the mechanisms by which smoking induces adenocarcinoma are largely inferred from the analysis of fully developed tumors. The current work focuses on the early events that precede the existence of clinically detectable tumors and where the progressive mechanisms are believed to be different from the ones driving established tumor growth. Biological information was drawn from the literature and generalized into a conceptual model, or framework, which describes and integrates the main processes involved in the early stages of smoking-induced lung adenocarcinoma development. No such integrative representation currently exists. The biological framework presented here is based on the “field of injury” of the lung. It covers the smoking-induced stepwise transition of unexposed (naive) lung tissue to the first appearance of neoplastic cells through defined tissue states referred to as pre-field and field. Each tissue state exhibits its own formalized characteristics (or phenotype properties), which evolve as a result of the combined effects of smoking, the interactions between the different tissue properties, and the local environment represented in the framework as lung inflammation and immune surveillance. The resulting network of influences between the lung tissue states and properties provides a good understanding of the early events involved in lung adenocarcinoma triggered by smoking. The resulting conceptual model—an integrative mechanistic hypothesis—can explain a broad range of cigarette smoking and smoking cessation scenarios.展开更多
OBJECTIVE:Accumulation of advanced glycation end products(AGEs) in the body due to the non-enzymatic glycation of proteins and oxidation is associated with aging and diabetes mellitus.In this study we wanted to invest...OBJECTIVE:Accumulation of advanced glycation end products(AGEs) in the body due to the non-enzymatic glycation of proteins and oxidation is associated with aging and diabetes mellitus.In this study we wanted to investigate the antiglycation and antioxidation potential of two medicinal plants:Juglans regia and Calendula officinalis.METHODS:In-vitro investigation was carried out to discover the antiglycation and antioxidation potential of J.regia and C.officinalis.Using an Ultraviolet Double-beam Spectrophotometer,we evaluated the antiglycation property of the crude methanolic extracts of J.regia and C.officinalis by assessing their ability to inhibit the Maillard reaction.Employing the same instrument we also measured the antioxidation potential of these plant extracts using the nitric oxide(NO) free radical-scavenging assay.RESULTS:J.regia had greater antiglycation ability,with a minimum inhibitory concentration(MIC 50) of 28 μg/mL as compared with that of C.officinalis(270 μg/mL).C.officinalis had greater antioxidation potential(26.10,22.07 and 16.06% at 0.5 mg,0.25 mg and 0.125 mg,respectively,as compared with 18.15,16.50 and 16.06% of J.regia,respectively).CONCLUSION:J.regia and C.officinalis inhibited the Maillard reaction and prevented oxidation in-vitro.Hence,the extracts of these plants could have therapeutic uses in curbing chronic diabetic complications and slowing down aging.展开更多
文摘Chronic exposure to cigarette smoke is the leading cause of human lung cancer and its most prevalent form, adenocarcinoma. However, the mechanisms by which smoking induces adenocarcinoma are largely inferred from the analysis of fully developed tumors. The current work focuses on the early events that precede the existence of clinically detectable tumors and where the progressive mechanisms are believed to be different from the ones driving established tumor growth. Biological information was drawn from the literature and generalized into a conceptual model, or framework, which describes and integrates the main processes involved in the early stages of smoking-induced lung adenocarcinoma development. No such integrative representation currently exists. The biological framework presented here is based on the “field of injury” of the lung. It covers the smoking-induced stepwise transition of unexposed (naive) lung tissue to the first appearance of neoplastic cells through defined tissue states referred to as pre-field and field. Each tissue state exhibits its own formalized characteristics (or phenotype properties), which evolve as a result of the combined effects of smoking, the interactions between the different tissue properties, and the local environment represented in the framework as lung inflammation and immune surveillance. The resulting network of influences between the lung tissue states and properties provides a good understanding of the early events involved in lung adenocarcinoma triggered by smoking. The resulting conceptual model—an integrative mechanistic hypothesis—can explain a broad range of cigarette smoking and smoking cessation scenarios.
文摘OBJECTIVE:Accumulation of advanced glycation end products(AGEs) in the body due to the non-enzymatic glycation of proteins and oxidation is associated with aging and diabetes mellitus.In this study we wanted to investigate the antiglycation and antioxidation potential of two medicinal plants:Juglans regia and Calendula officinalis.METHODS:In-vitro investigation was carried out to discover the antiglycation and antioxidation potential of J.regia and C.officinalis.Using an Ultraviolet Double-beam Spectrophotometer,we evaluated the antiglycation property of the crude methanolic extracts of J.regia and C.officinalis by assessing their ability to inhibit the Maillard reaction.Employing the same instrument we also measured the antioxidation potential of these plant extracts using the nitric oxide(NO) free radical-scavenging assay.RESULTS:J.regia had greater antiglycation ability,with a minimum inhibitory concentration(MIC 50) of 28 μg/mL as compared with that of C.officinalis(270 μg/mL).C.officinalis had greater antioxidation potential(26.10,22.07 and 16.06% at 0.5 mg,0.25 mg and 0.125 mg,respectively,as compared with 18.15,16.50 and 16.06% of J.regia,respectively).CONCLUSION:J.regia and C.officinalis inhibited the Maillard reaction and prevented oxidation in-vitro.Hence,the extracts of these plants could have therapeutic uses in curbing chronic diabetic complications and slowing down aging.
