“How Smoking Causes Lung Cancer”的版本间的差异

2013年5月1日 (三) 17:08的版本

Lung cancer is a global issue and it is the most popular cancer on earth. Annually the cases of lung cancer are sadly improving. It's become fast worse in developing and former socialist countries, where smoking rate is still high, even though usage of tobacco has dropped in many high income countries. Everyone knows that smoking causes lung cancer but how smoking causes lung cancer is a issue that no body really knows. In this specific article I'll explain how smoking causes lung cancer.A cigarette smoking is really a very intricate combination of various substances. A lot more than 4000 different compounds have now been indentified in mainstream cigarette smoke. From these 4000 and a bit more compounds 60-70 are carciongens: heterocyclic hydrocarbons, N -heterocyclic amines, polycyclic aromatic hydrocarbons (PAH), D -nitrosamines, aromatic amines, natural compounds, aldehydes, inorganic compounds like hydrazine and some materials and free radicals e cigarette unhealthy.Tobacco includes a high level of N-nitrosamines and PAH-s, which are which are strong carciogens. Different substances seem to have lower carciogenic potential. Numerous studies have shown that PAH-s may cause cancers in laboratory animals. PAH- are formed by partial combustion of tobacco. Studies have also found that PAH-s could connect to the DNA, developing mutagenic DNA adducts. And the formation of DNA adducts may be the major starting event of carciogenesis.The concentration of N-nitrosamines in tobacco is fairly large and heavy smokers have the highest exposure to these compounds. The tobacco-specific N -nitrosamines (TSNA), generally the nicotine-derived NNK, will be the strongest respiratory toxins identified in tobacco products. Both benign and malignant tumors are formed in rodents, mice and mice have already been activated by NNK. The focus of NNK in conventional smoke has risen while those of benzo( a pyrene have decreased because the 1960s.The smoke of cigarettes also includes lots of free radicals and oxidative damage is caused by free radicals. Both particulate and gas phase are highly oxidative and therefore damage the lung. Cigarette smoke also triggers proinflammatory cytokines and employees triggered macrophagesand neutrophils to lung tissue.Cigarettes have a very high levels of materials. About 30 materials have already been identified. Some research indicates that metals are powerful initiators of the carcinogenic process, but can be likely supporters during carcinogenesis. Cigarette smoke contains high degrees of cadmium, chromium and also nickel. Chromium accumulates in the tobacco and lung smoking may be the primary supply of cadmium exposure in individuals. Unfortunately the contribution of the metals to lung cancer is poorly understood.