[BBC News] Arthritis drug dangers explained

Published: 2006/11/29 00:01:07 GMT

◆ arthritis:關節炎

rheumatoid arthritis:類風濕性關節炎

Scientists believe they have uncovered why some arthritis drugs such as Vioxx can cause heart attacks and strokes.

下面心臟病及中風的徵兆取自American Heart Association 網站。

◆ heart attack:心臟病發

Chest discomfort. Most heart attacks involve discomfort in the center of the chest that lasts more than a few minutes, or that goes away and comes back. It can feel like uncomfortable pressure, squeezing, fullness or pain.
Discomfort in other areas of the upper body. Symptoms can include pain or discomfort in one or both arms, the back, neck, jaw or stomach.
Shortness of breath. May occur with or without chest discomfort.
Other signs: These may include breaking out in a cold sweat, nausea or lightheadedness

◆ stoke:中風

Sudden numbness or weakness of the face, arm or leg, especially on one side of the body
Sudden confusion, trouble speaking or understanding
Sudden trouble seeing in one or both eyes
Sudden trouble walking, dizziness, loss of balance or coordination   
Sudden, severe headache with no known cause

They found Cox-2 inhibitor painkillers were stopping an enzyme producing blood-thinning agents - leading to a greater chance of blood clotting.

生化裡頭的inhibitor 通常是指會抑制其他酵素(enzyme)活動的物質,使酵素不能活化,進而無法催化一些細胞內的活動。

【註】enzyme:中文好像都翻譯成「酶」,現在最熱門的enzyme 應該是Q10了吧。

 Cox-2 是一種enzyme,全名為cyclo-oxgenase,它在脂肪酸(fatty acid)轉換成賀爾蒙prostaglandin(PGH) 的化學反應中扮演催化的腳色。身體受傷的地方會刺激Cox-2 產生更多的PGH,因此會擴大發炎(inflammation)的情況,造成疼痛。

◆ blood-thining:血液稀釋。

這裡指Cox-2 inhibitor 抑制了能夠稀釋血液的物質(blood-thinning agents),血液不能被稀釋,血液裡的血小板(platelet)濃度也因此比正常高,於是就更容易造成血液凝結。

血液凝結的動詞是用clot:blood clotting

◆ painkiller:止痛劑

Vioxx and other Cox-2 inhibitors have been pulled from the market because of their risks to health.

Vioxx® 和其他Cox-2 inhibitors 因為會對健康造成危害,而被從市場回收。

◆ be pulled from the market

這個研究已經發表在期刊Federation of American Societies for Experimental Biology 上。

After Vioxx was withdrawn in 2004, its manufacturer Merck was ordered to pay $253.4m (£141m) to the widow of a man who died from a heart attack blamed on the drug. The US pharmaceutical giant is currently facing thousands of law suits.

自從2004年Vioxx® 從市場下架後,它的製造商Merck因為一位寡婦的丈夫被指稱死於藥物造成的心臟病發,而被要求賠償$243.4百萬美金。

◆ law suit:訴訟案件

◆ giant:
 [n] 巨人、巨物;卓越人物【例:a giant in the field of biochemistry】
 [a] 巨大的;偉大的【例:a giant impact】

這裡的pharmaceutical giant 指的是Merck 這間製藥公司。

Other Cox-2 inhibitor drugs have since been withdrawn from the market or are accompanied by strong warnings of the possible damaging effects on health.

其他Cox-2 inhibitor 也因此下架,或使用者會被嚴重警告其藥性對健康可能會產生的傷害。

除了之前用過的be pulled from the market,這裡用withdrawn。

◆ be withdrawn from the market

◆ be accompanied by strong warnings

這裡用accompany(伴隨),除了用在「人」身上,如:She is accompanied by her friends.
也可以這樣用:Heavy rain is usually accompanied with thunder.

However, the precise mechanism of how this class of drug can boost the risk of heart attack or stroke has up to now remained unknown.

◆ mechanism:機制,生化中非常常用到的字。【例:mechanism of signaling transduction】

◆ boost the risk


那,什麼是blooding-thinning agents 呢?

Blood-thinning agents

Cox-2 inhibitors work by blocking the Cox-2 enzyme, thereby halting the production of hormones that swell the joints and cause pain.

Cox-2 inhibitors 之所以可以止痛,是因為它抑制了Cox-2,進而抑制了會擴大關節發炎情況而產生疼動的賀爾蒙(hormones)的製造。

But the team has discovered the inhibitors are also blocking an enzyme called Cox-1 inside of the cells that line blood vessels.

但是他們也發現inhibitors 不只會抑制Cox-2,也會抑制Cox-1。

Within these cells, Cox-1 is responsible for producing a blood-thinning agent called prostacyclin, but if the enzyme is blocked, the blood may clot and heighten the risk of heart attack or stroke.

在細胞裡面,Cox-1 的責任是製造可以稀釋血液的prostacyclin(也是屬於PGH家族,又叫PGI2),所以如果Cox-1 被抑制了,它就沒辦法製造prostacyclin,這樣就會造成血液過濃,增加了血液凝結和心臟病發及中風的機率。

在這裡補充一下,我們日常生活中常用的止痛劑阿斯匹靈(Aspirin)也是Cox-1 和Cox-2 inhibitor 喔!這也是為什麼阿斯匹靈能止痛,因為它能夠抑制Cox-2 來減低發炎的情況。

既然阿斯匹靈也是Cox-1 inhibitor,那為什麼醫生說每天吃微量的阿斯匹靈能預防血管阻塞呢?回去翻了一下生化課本,因為Cox -1 所催化的反應中,有一個會產生TxA2,作用是促進血液凝結,通常會和PGI2 互相抗衡。阿斯匹靈抑制了Cox-1,相對的也抑制了TxA2 的產生,減低了血液凝結的功能。

The researchers said the findings are significant because it may lead to the development of Cox-2 drugs which do not carry these side-effects.

研究學者說這個發現很重要,因為這樣就可以研發出不會產生副作用的Cox-2 藥物。

◆ side-effect:副作用

帶有副作用的動詞是用carry:drugs that carry the side-effects

Professor Jane Mitchell, an author of the study from the National Heart and Lung Institute at Imperial College London, said: "Cox-2 inhibitors can have great benefits for patients suffering from conditions such as arthritis and it would be great if they could remain available.

"However, the problem is that their use appears associated with an increased risk of heart attacks."

雖然Cox-2 對關節炎病人來說是種福利,但是問題是,它會增加心臟病發的危險性。

Professor Tim Warner, a co-author from Barts and the London at Queen Mary University of London, said: "Our new research is exciting because it means we can work on developing better Cox-2 inhibitors that don't pose the same risks in terms of heart attacks and strokes." Professor Alan Silman, the incoming medical director of the Arthritis Research Campaign, said it was important to pinpoint possible mechanisms for the side-effects of these drugs.


◆ pose the same risk


例:pose a question (提出問題)
  pose a threat (提出威脅)

◆ in terms of (idiom): regarding or indicated by.


risk in terms of heart attacks and strokes 像心臟病或中風這類的危險性

◆ pinpoint:
 [v] 瞄準(pinpoint a target 瞄準目標);提出、指出(pinpoint the flaws 指出缺點)
 [a] 精準的(pinpoint accuracy 精準無誤);極小的(pinpoint creature 微小生物)

do something with pinpoint accuracy

However, he added, the bigger picture was still not clear. Recent research, he said, had shown some Cox-2 inhibitor drugs did not seem to increase the risk of these side-effects while some of the traditional drugs did.

但是,這項研究的大藍圖還不清楚。最近研究顯示,跟傳統藥物相比,一些Cox-2 inhibitor drugs 看起來並沒有較高的危險性。

◆ big picture


He said it was important to work out the reasons behind this.


◆ work out (idiom)

例:work out a plan (訂出一個計畫)

或是「有個滿意的結果」、「可行」的意思,如:This plan did not work out. (這個計畫不成功。)

另外,現在還算流行的「上健身房」也是用work out 這個詞,如:Let's go work out! (我們去健身房吧!)

之前在Summerland 做co-op 的時候,一起的UBC co-op 學生下班後會問我:do you want to work out tonight?

The UK team believes their findings may help to develop drugs that do not have this side-effect.


citation from The American Heritage® Dictionary of Idioms. Houghton Mifflin Company, 1992. Answers.com 03 Dec. 2006. (按圖可連結到引用頁面)


[CBC News] Vioxx's heart risk tied to clotting effect
[Pharm Business Review] Study may reveal cause of Vioxx side effects

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