亚洲免费av电影一区二区三区,日韩爱爱视频,51精品视频一区二区三区,91视频爱爱,日韩欧美在线播放视频,中文字幕少妇AV,亚洲电影中文字幕,久久久久亚洲av成人网址,久久综合视频网站,国产在线不卡免费播放

        ?

        時(shí)文限時(shí)閱讀訓(xùn)練

        2020-04-30 06:43:17潘井正
        關(guān)鍵詞:灌南時(shí)文硬化癥

        多發(fā)性硬化癥(Multiple sclerosis)是一種影響包括大腦、視神經(jīng)和脊髓等中樞神經(jīng)系統(tǒng)的疾病。來(lái)自哈佛大學(xué)附屬研究院安·羅姆尼中心研究神經(jīng)系統(tǒng)疾病的一群專家開(kāi)始研究為什么多發(fā)性硬化癥會(huì)隨著季節(jié)的變化而變化——隨著白天時(shí)間的變短而有所改善。

        For patients and clinicians alike, its long been a mystery: Why do symptoms of multiple sclerosis (MS) seem to get better in the winter and worse in the summer? A group led by Francisco Quintana and collaborators have found an explanation that could lead to a deeper understanding of the disease and more targeted treatment options for patients. By looking first broadly at possible environmental factors and then deeply at preclinical models of MS, the research team found that melatonin—a hormone involved in regulating a persons sleepwake cycle—may influence MS disease activity. The team reports its findings this week in Cell.

        “We know that for multiple sclerosis and most autoimmune diseases, both genetic and environmental factors play an important role, but in the last decade, most research has focused only on the genetic side of the equation,” said cocorresponding author Quintana. “But we wanted to see what environmental factors would reveal to us about this disease. We knew that MS disease activity changed with the seasons. What weve uncovered offers an explanation for why that is the case.”

        Quintana and his colleagues began by studying patients. The team found that during the fall and winter, the group of 139 relapsing? remitting? MS patients they studied experienced a significant improvement in symptoms—a phenomenon thats been observed in previous studies. The team then explored a variety of environmental? factors that have been proposed as possibly linked to MS symptoms, including vitamin D levels, UV incidence, and upper respiratory tract infections. But the factor that was consistently associated with severity of MS symptoms was melatonin. Melatonin levels are known to correlate with the durations of days—during the longer days of the spring and summer, levels are lower; during the shorter days of the fall and winter, levels are higher.

        Based on this observation, the team tested this lead in the lab, studying the role that melatonin may play on a cellular level. Using both a mouse model and human cells, they investigated the effects of melatonin on certain types of cells known to play a role in the immune response that leads to MS symptoms. The team found that melatonin affected the roles of two kinds of cells that are important in MS disease progression: pathogenic T cells, which directly attack and destroy tissue, and regulatory T cells, which are supposed to keep pathogenic T cells in check.

        “We found that melatonin has a protective effect,” said Quintana. “It dampens the immune response and helps keep the bad guys—or pathogenic T cells—at bay.”

        Although melatonin is available over the counter, it has significant drawbacks, including causing unwanted drowsiness. The teams goal is to tease apart the molecular mechanisms that underlie melatonins role in order to develop targeted, nontoxic drugs that are safe and effective with minimal side effects.

        “In the future, melatonin or its derivatives may be used in MS patients after appropriate clinical trials are conducted and dosage is established,” said Quintana. “However, extreme caution should be exercised: Our data do not show that melatonin or its analogs are effective in treating MS.”

        1.? ? Which of the following descriptions is not right?

        A.? Melatonin dampens the immune response and helps keep pathogenic T cells at bay.

        B. The team found that pathogenic T cells directly attack and destroy tissue.

        C. The research team has no idea whether MS disease changed with the season.

        D. It is known that melatonin levels are associated with the durations of days.

        2.? ? What can be inferred from the article?

        A.? Most research focus only on the genetic side because environmental factors are not important.

        B. The research has developed targeted, nontoxic drugs? that are safe and effective with no side effects.

        C. Why symptoms of MS seem to get better in the winter and worse in the summer is a myster.

        D. Scientists havent found out whether melatonin or? its analogs are effective in treating MS so far.

        3.? ? Which of the following factors is consistently linked to severity of MS symptons?

        A. Vitamin D levels.? B. UV incidence.

        C. Upper respiratory.? D. Melatonin.

        4.? ? Which of the following word can best replace the underlined word in paragrah three?

        A. Avoiding.? B. Decreasing.

        C. Relieving.? D. Changing.

        5.? ? What is the main idea of this article?

        A.? Why MS symptoms may improve as days get shorter?

        B. What is multiple sclerosis (MS)?

        C.? How to cure patients of multiple sclerosis (MS).

        D. A deadly disease

        參考答案

        1—5 CDDCA

        (作者:潘井正,江蘇省灌南高級(jí)中學(xué))

        猜你喜歡
        灌南時(shí)文硬化癥
        痛風(fēng)的多組學(xué)研究進(jìn)展
        遺傳(2023年8期)2023-08-25 07:00:20
        小城鎮(zhèn)公園景觀設(shè)計(jì)中鄉(xiāng)土元素的應(yīng)用分析
        談時(shí)文閱讀在小學(xué)寫(xiě)作教學(xué)中的應(yīng)用
        題型專練
        耳硬化癥的臨床與影像分析
        正確認(rèn)識(shí)多發(fā)性硬化癥
        灌南縣農(nóng)作物秸稈綜合利用存在的問(wèn)題及發(fā)展對(duì)策
        肌萎縮側(cè)索硬化癥的重復(fù)電刺激研究
        智 珠
        英語(yǔ)時(shí)文閱讀
        国产av丝袜熟女丰满一区二区| a级毛片免费观看网站| 日本丰满熟妇bbxbbxhd| 精品一区二区三区无码视频| 四虎成人在线| 国产精品久久久久久久专区| 国产精品午夜福利天堂| 国产一级内射视频在线观看| 久久精品国产亚洲av麻豆| 成人免费va视频| 国产精品国产三级在线专区| 精品乱色一区二区中文字幕| 亚洲欧洲免费无码| 国产精品嫩草99av在线| 国产精品美女一区二区三区| 国产亚洲精品综合一区| 国产一区二区av男人| 日韩精品极品系列在线免费视频| 精品无人区无码乱码毛片国产| 亚洲一区二区三区偷拍视频| 国内揄拍国内精品人妻久久| 蜜臀性色av免费| 欧美精品v国产精品v日韩精品| 亚洲美女影院| 亚洲女同系列高清在线观看 | 新久久国产色av免费看| 18精品久久久无码午夜福利 | 久久精品免视看国产盗摄| 日韩在线精品免费观看| 久久久免费看少妇高潮| 51看片免费视频在观看| 国模无码人体一区二区| 不卡国产视频| 国产精品夜色视频久久| 精品香蕉一区二区三区| 久久久久亚洲av片无码v| 一本无码av一区二区三区| 国产一级黄色片一区二区| 国内精品久久久久国产盗摄| 欧美午夜刺激影院| 无遮挡很爽视频在线观看|