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  • 致癌物和癌症

    What's the worst thing you can do to hurt your health?
    ::最糟糕的事情是什么 你能做 伤害你的健康?

    Besides , many other dangers in the environment may negatively affect human health. For example, can cause lung . It can also make asthma and other diseases worse. is another potential threat in the environment. It may poison large numbers of people or cause epidemics of deadly diseases. But the worst thing you can do to yourself is smoke cigarettes.
    ::此外,环境中的许多其他危险也可能对人类健康产生不利影响,例如,可能导致肺部疾病,也可能使哮喘和其他疾病恶化,这是环境的另一个潜在威胁,可能毒害大量人口或造成致命疾病的流行,但最坏的办法是吸烟。

    Carcinogens and Cancer
    ::致癌物和癌症

    Cancer is one of many human diseases that can be caused by the environment. Air pollution may increase the risk of lung cancer and can also cause or worsen asthma, , and other health problems. Bioterrorism is another potential threat to human health and may lead to severe environmental problems that have the potential to poison large numbers of people or cause epidemics of deadly diseases.
    ::癌症是环境可能造成的许多人类疾病之一,空气污染可能增加肺癌的风险,也可能造成或加剧哮喘、哮喘和其他健康问题,生物恐怖主义是对人类健康的另一个潜在威胁,并可能导致严重的环境问题,有可能毒害大量人口或造成致命疾病的流行。

    Carcinogens
    ::致癌物

    Carcinogens may be pathogens, chemical substances, or radiation, and they often occur in nature. Some are important carcinogens; different viruses cause as many as 15 percent of all human cancers. The human papilloma virus (HPV) is the main cause of cervical cancer in females, the hepatitis B virus can cause liver cancer, and the Epstein-Barr virus can cause cancer of the lymph nodes .
    ::致癌物可能是病原体、化学物质,也可能是辐射,它们经常发生于自然之中。 其中一些是重要的致癌物;不同的病毒导致人类癌症的15%。 人类乳头瘤病毒(HPV)是女性宫颈癌的主要原因,乙型肝炎病毒可能导致肝癌,而Epstein-Barr病毒可能导致淋巴结癌。

    The most common natural carcinogen is ultraviolet (UV) radiation from the sun and is the leading cause of skin cancer . Exposure to radon , a natural, radioactive gas that seeps out of the ground, can cause lung cancer. Asbestos can also cause lung cancer. A mineral previously used for insulation and many other purposes, asbestos has been banned because of its link to cancer.
    ::最常见的自然致癌物是太阳的紫外线(UV)辐射,是导致皮肤癌的主要原因,接触从地面渗出的天然放射性气体 -- -- 可导致肺癌,石棉也可能导致肺癌,石棉是一种以前用于绝缘和其他许多用途的矿物,由于它与癌症有关,因此被禁止使用石棉。

    In addition to naturally occurring carcinogens, humans are exposed to many artificial carcinogens including those in tobacco smoke. Tobacco smoke contains dozens of carcinogens including nicotine and formaldehyde, which is used to preserve dead bodies. This smoke may be the primary source of human exposure to carcinogens. Other artificial carcinogens are or were found in foods. Some food additives, such as food dyes, have proven to be carcinogens. Cooking foods at very high temperatures also causes carcinogens to form. A carcinogen called acrylamide forms when are cooked at very high temperatures. It is found in foods such as french fries and potato chips. Barbecued or broiled meats also contain several carcinogens.
    ::烟草烟雾含有数十种致癌物,包括用于保存尸体的尼古丁和甲醛;这种烟雾可能是人类接触致癌物的主要来源;在食物中发现或曾经发现过其他人造致癌物;一些食品添加物,如食物染料,已证明是致癌物;在极高温度下烹饪食物也造成致癌物;一种在极高温度下烹饪时被称为丙烯酸形式的致癌物;在薯条和薯片等食品中发现过。

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    Barbecued foods are cooked at very high temperatures. This may cause carcinogens to form.
    ::烧烤食品在极高的温度下煮熟,可能导致致癌物形成。

    How Cancer Occurs
    ::癌症发生情况如何

    Carcinogens generally cause cancer by inducing in genes that control or other aspects of the . The mutations typically occur in two types of genes: tumor-suppressor genes and proto-oncogenes . These two types of genes are briefly discussed below:
    ::致癌素一般通过诱导基因来控制或控制这些基因的其他方面而致癌。

    • Tumor-suppressor genes are genes that normally repair damaged or prevent with badly damaged DNA from dividing ( Figure   ). If mutations occur in these genes, they may no longer be able to prevent cells with damaged DNA from dividing ( Figure   ).
      ::肿瘤压抑基因通常是修复受损基因或防止严重损坏的DNA分解的基因(图)。如果这些基因发生突变,它们可能不再能够防止有受损DNA的细胞分解(图)。
    • Proto-oncogenes are genes that normally help regulate cell division. Mutations can turn them into oncogenes . Oncogenes are abnormal genes that stimulate the division of cells with damaged DNA.
      ::蛋白蛋白质是通常有助于调节细胞分裂的基因。 突变可以将蛋白质转化为蛋白质。 蛋白质是不正常的基因,刺激细胞与受损的DNA的分离。

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    Figure A: A cell with damaged DNA is normally not allowed to divide, so the damage is not passed on to other cells. Figure B: If a cell with damaged DNA is allowed to divide, it results in many more damaged cells.
    ::图A:一个DNA受损的细胞通常不得分离,因此损害不会传到其他细胞。 图B:如果允许DNA受损的细胞分离,则导致更多的细胞受损。

     

      

     

    Cells that divide uncontrollably form a tumor , which is an abnormal mass of tissue that can be benign or malignant. Benign tumors remain localized and generally do not harm health. Malignant tumors are cancerous, have no limits on their growth, and invade and damage neighboring tissues. Cells from malignant tumors can also break away from the tumor, enter the , and start growing in another part of the body. This is called metastasis.
    ::无法控制地分裂成肿瘤的细胞,肿瘤是一种非正常的组织质量,可以是良性的或恶性的。 恶性肿瘤仍然局部存在,一般不会损害健康。 恶性肿瘤是癌症,其生长没有限制,入侵和破坏近身组织。 恶性肿瘤的细胞也可以脱离肿瘤,进入体内,开始在身体的另一部分生长。这被称为转移。

    Types of Cancer
    ::癌症类型

    Cancer is usually classified according to the type of tissue where the cancer begins. Common types of cancer include the following:
    ::癌症通常按癌症发端的组织类型分类。

    • Carcinoma : Tumor of epithelial tissues such as lung tissue.
      ::肿瘤:肺组织等上皮组织肿瘤。
    • Sarcoma : Tumor of connective tissues such as .
      ::Sarcoma: 连接组织(例如)的肿瘤 。
    • Lymphoma : Tumor of lymphatic cells such as T cells .
      ::淋巴瘤:T细胞等淋巴细胞的肿瘤。

    Specific cancers are generally named after the organs where the cancers begin. Relatively common cancers include lung, prostate, bladder , and breast cancers. These and several other cancers are listed in Table .
    ::特定癌症通常以癌症发端的器官命名,相对常见的癌症包括肺癌、前列腺癌、膀胱癌和乳腺癌。

    Common Cancers among Adult Males and Females in the United States
    Adult Males Adult Females
    Most Common Cancers (percent of all cancers) Most Common Causes of Cancer Deaths (percent of all cancer deaths) Most Common Cancers (percent of all cancers) Most Common Causes of Cancer Deaths (percent of all cancer deaths)
    Prostate cancer (33%) Lung cancer (31%) Breast cancer (32%) Lung cancer (27%)
    Lung cancer (13%) Prostate cancer (10%) Lung cancer (12%) Breast cancer (15%)
    Colorectal cancer (10%) Colorectal cancer (10%) Colorectal cancer (11%) Colorectal cancer (10%)
    Bladder cancer (7%) Pancreatic cancer (5%) Endometrial cancer (6%) Ovarian cancer (6%)

    Cancer can also occur in children and teens, but it is rare. Most childhood cancers occur during the first year of life. The most common type of infant cancer is leukemia, which accounts for about 30 percent of cancers at this age. With prompt treatment, there is a good chance that an infant with cancer will survive.
    ::癌症还可能发生在儿童和青少年身上,但很少发生。 儿童癌症大多发生在婴儿出生的第一年。 最常见的婴儿癌症类型是白血病,占这个年龄癌症的30%左右。 通过及时治疗,患癌症的婴儿很有可能存活下来。

    Cancer Treatment and Prevention
    ::癌症治疗和预防

    Most cancers can be treated, and some can be cured. Cancer may be treated with a combination of surgery, chemotherapy , and/or radiation, with the goal of removing the tumor without damaging the body. In the past, chemotherapy drugs caused serious side effects, but many of today’s chemotherapy drugs target specific molecules in tumors, therefore reducing damage to normal and causing fewer side effects.
    ::大多数癌症都可以治疗,有些也可以治愈。 癌症可以通过手术、化疗和(或)辐射相结合来治疗,目的是除去肿瘤而不伤害身体。 过去,化疗药物造成了严重的副作用,但今天的许多化疗药物都针对肿瘤中的特定分子,从而减少了对正常的伤害,减少了副作用。

    The outcome of cancer treatment depends on factors such as the type of cancer and its stage. The stage of cancer refers to the extent to which the cancer has developed. Stage 1 cancers are localized and can be relatively easily removed with surgery, while stage 4 cancers have metastasized and are much more difficult to remove completely. Generally, early diagnosis and treatment lead to the best chances of survival. Typical warning signs of cancer include the following:
    ::癌症治疗的结果取决于癌症类型及其阶段等因素,癌症的阶段是指癌症发展的程度。第一阶段癌症是局部的,通过外科手术可以相对容易地消除,而第四阶段癌症已经转移,更难完全消除。一般而言,早期诊断和治疗最有可能存活。癌症的典型警告迹象包括:

    • A change in bowel or bladder habits.
      ::肠胃或膀胱习惯的改变。
    • A sore that does not heal.
      ::伤口无法愈合
    • Unusual bleeding or discharge.
      ::异常出血或出院
    • A lump in the breast or other parts of the body.
      ::胸腔或身体其他部位的肿块。
    • Chronic indigestion or difficulty in swallowing.
      ::慢性消化不良或吞咽困难。
    • Obvious changes in a wart or mole.
      ::明显变异的微小或内鬼。
    • Persistent coughing or hoarseness.
      ::持续咳嗽或粗糙。

    Having warning signs of cancer does not mean that you have cancer, but you should see a doctor to be sure. Getting recommended tests for particular cancers, such as colonoscopies for colon cancer, can also help detect cancers early, when chances of a cure are greatest.
    ::癌症的警告征兆并不意味着你有癌症,但你应该看医生才能确定。 接受推荐的特定癌症的检测,如结肠癌的结肠镜检查,也可以帮助早期发现癌症,而当治愈的可能性最大时。

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    Regular checkups with a dermatologist can help detect skin cancers early. Why is early detection important?
    ::皮肤科医生的定期检查有助于及早发现皮肤癌。 为什么早期发现很重要?

    Many cancers can be prevented, or at least their risks can be reduced. You can help reduce your risk of cancer by avoiding specific carcinogens and maintaining a healthy lifestyle. Carcinogens you can avoid or limit your exposure to include tobacco smoke, sexually transmitted viruses, improperly cooked foods, and UV radiation . Other lifestyle choices you can make to reduce your risk of cancer include being physically active, eating a low-fat diet, and maintaining a normal weight.
    ::许多癌症是可以预防的,或者至少可以降低其风险。您可以通过避免特定致癌物和保持健康的生活方式来帮助降低癌症风险。 致癌物可以避免或限制暴露于烟草烟雾、性传染病毒、不正确烹饪的食物和紫外线辐射。 为降低癌症风险,您还可以做出其他生活方式选择,包括身体活跃、吃低脂肪饮食以及保持正常体重。

    Summary
    ::摘要

    • Cancerous tumors are caused by two types of genetic mutations.
      ::癌症肿瘤是由两种基因突变引起的。
    • These mutations are primarily a result of environmental carcinogens.
      ::这些突变主要是环境致癌物造成的。
    • Cancers are most easily treated when the cancer is caught in the early stages, so early detection is important.
      ::当癌症处于早期阶段时,癌症最容易得到治疗,因此早期发现很重要。

    Review
    ::回顾

    1. What is the difference between proto-oncogenes and tumor-suppressor genes?
      ::蛋白质和肿瘤抑制基因有什么区别?
    2. What environmental carcinogens are the most common?
      ::哪些环境致癌物最为常见?
    3. What cancers are the most common? The most deadly?
      ::最常见的癌症是什么?最致命的?