Newsletter No. 419

12 No. 419, 4.6.2013 趙慧君教授 化學病理學系 請給讀者說一下目前做的研究好嗎？ 主力研究是分析人的血液樣本所含的林林總總的DNA物質，擴大 血液測試的應用範圍，以代替抽取活檢樣本的較高風險檢查。傳 統認知是必須抽取器官組織才可做DNA診斷，但原來人體細胞 因新陳代謝或疾病而壞死的時候，其新陳代謝物會浮在血漿裏。  盧煜明 教授在1997年證實孕婦的血液含有胎盤的新陳代謝物，從 而可化驗出胎兒的DNA。此後十多年進度驚人，2008年發展出唐 氏綜合症無創產前檢測，2010年，我們已可利用母體血液樣本中 微量的胎兒DNA，排列出胎兒的完整基因圖譜，理論上可以檢測 出任何遺傳病。目前，我們已能透過血液樣本重整出肝癌、乳癌和 卵巢癌等細胞的基因圖譜，目標是發展出應用範圍廣泛、可頻密進 行的無創癌症檢查，偵測所有基因異變。 就安潔莉娜  • 裘莉主動接受乳房組織切除手術引起的廣泛 回響，你認為醫生對考慮這類「預防性」手術的人士應給予 甚麼忠告？ 安潔莉娜  • 裘莉 的病例和手術並不新鮮，她了不起之處是公開自 己的決定和手術過程，提高大眾對基因診斷的認知，凸顯醫生在 這方面應有的專業操守：一、對基因疾病應有豐富認識；乳癌是 女性頭號殺手之一，大概百分之十由家族遺傳的BRCA 1 基因病變 引起。有這種基因病變的人，在七十歲之前乳癌和卵巢癌的發病 率分別是八成和四成。醫生有責任向有家族乳癌病例的病人介 紹BRCA 1 檢測。二、充分輔導，清晰解釋檢測局限，以及各種檢測 結果所牽涉的應對方法，譬如結果屬陽性，家庭成員也將面臨檢 測的壓力。三、細陳利弊；解釋動手術可降低患癌風險的程度、手 術過程及日後對身心的潛在影響，讓病人有足夠的資訊權衡是否 接受檢測和手術。 你如何看基因檢測所引起的道德爭議？ 基因診斷如同任何新科技一樣，都會帶出新問題和令部分人不安， 只要有足夠的認知，有效善用，是無需擔心的。在健全的醫學體制 裏，例如在香港，所有醫學檢測須由醫生轉介，也需經過篩選，例 如針對可治療的遺傳疾病，或有高危家族史的疾病如地中海貧血 症。醫生得嚴格把關，確保沒有不當使用檢測技術，以及正確解讀 檢測結果。 你獲得楊孟思教授賞識，走上研究之路。如果要物色徒弟 或接班人，會側重甚麼質素？ 先決條件是熱誠，有渴望服務社會作出改變的心，否則難以在爭 分奪秒的世界研究平台上突圍而出。其次是邏輯思考；做研究着眼 點不在於顯而在於隱，但隱而未發的往往是書本知識所不及揭示 之處，得靠蛛絲馬跡在千萬種可能性中依次發掘，每一步驟都精 密非常。第三是腳踏實地，虛心挖掘每一步驟背後的真理，不能訴 諸主觀略過某些步驟，否則便難窺全豹，但循序漸進之餘又得保 持思想開明，向不可能挑戰。 都說你擅長寫研究論文和建議書，箇中有甚麼竅門？ 尊重讀者─在寫每一篇文章前，我必謹慎斟酌要讓讀者有甚麼得 着。盧教授對我們的要求是一下筆便要令專業以外的讀者也能明 白論述範疇，同時鎖定其注意力，引起探索的興味。我注重上文下 理的邏輯思維，力求深入淺出而帶文采，令人閱後擊節讚賞，就像 看完歌劇站起來大聲喝采！研究經費申請書尤其要言簡意賅，提 綱挈領，讓評審人員在有限的寶貴時間內，迅速掌握研究重點和 價值所在，欣賞認同而批出款項。 眾所周知你是位出色的研究人員，你如何評價自己當教師 和母親的表現？ 每教一課，我都全力以赴。無論教的是專業人士、研究生還是本科 生，我定會先估量學生的平均水平和期望，籌算在有限的課時裏把 最重要的信息深印於他們的腦海。我的教材因應受眾而微調，不 會一成不變。施教時我時刻留意學生的反應，下課後自我評估，力 求改善。我重視工作，但工作是有盡期的，家人是永遠的，女兒是 我生命中很重要的部分，我不會讓工作侵蝕我當母親的角色。女兒 欣賞和尊重我的工作，和我的關係也很親 厚。我參與家長會和學校活動的頻密程度 曾令人誤會我是全職媽媽呢。 Prof. Rossa Chiu Department of Chemical Pathology Please tell us something about your current research. I’m primarily analysing the DNA materials in human blood samples, expanding the applications of blood tests with an aim to replace the need to collect biopsy samples which has a much higher risk. Conventionally, it was thought that organ tissues were required for DNA diagnoses. But in fact when cells die due to natural metabolism or illness, metabolic substances remain in the blood plasma. In 1997, Prof. Lo Yuk-ming Dennis discovered the presence of fetal DNA in the maternal blood plasma, and pioneered the use of such markers for fetal DNA diagnosis. In 2008, a non-invasive prenatal test for Down syndrome was developed. In 2010, we can decipher a genome-wide genetic map of the fetus through the analysis of the small amounts of fragmented DNA in the maternal blood. This allows us to develop non-invasive prenatal diagnostic tests for multiple genetic diseases in a non-invasive way. Currently, we can reconstruct genetic maps of liver, breast and ovarian cancer using blood samples. The aim is to develop methods for screening cancer and genetic mutations, that are non-invasive, widely applicable, and can be frequently carried out. In the wake of the so-called Angelina effect, what is the role of the medical practitioner in advising people considering such ‘preventative’ actions? Medically, Angelina Jolie ’s case is nothing new. Her uniqueness lies in publicizing her decision and the surgery. By doing so, she raises awareness of genetic diagnosis, and draws attention to the ethical principles doctors should have. Firstly, doctors should be knowledgeable about genetic disorders. Breast cancer is one of the main killers of women. About 10% of cases are caused by a BRCA 1 gene mutation. People with the mutation have a probability of 80% and 40% respectively, of developing breast cancer and ovarian cancer before age 70. Doctors should tell patients with a family history of breast cancer about the BRCA 1 test. Secondly, there should be adequate counselling, clear explanation of the test’s limitation and what different results entail. For example, if the result is positive, family members may be under pressure to take the test. Thirdly, doctors should explain the pros and cons in detail—by how much surgery would reduce the risk, the surgical process, its potential physical and psychological effects, so that patients are well informed about whether they should take the test or undergo the surgery. Genetic mapping has become a reality. What are the ethical issues? Like any new technology, genetic diagnosis makes some people uncomfortable. It introduces new problems, but with adequate knowledge and effective application, it’s nothing to worry about. Under a healthy medical system, like that in Hong Kong, all medical tests are referred by doctors and undergo a selection process. A case in point are tests for treatable hereditary diseases or illnesses with a family history such as Thalassemia. Doctors have to be strict gate-keepers, ensuring that testing technology is appropriately deployed and results are interpreted accurately. You were chosen by Prof. Magnus Hjelm to take the path of research. What qualities would you look for if you were to identify someone to be your mentee or understudy? Passion is what I look for first—a desire to serve and bring change. This is crucial if you want to stand out in the highly competitive global research arena. Logical thinking is also important. In doing research, having an eye for the non-obvious, yet the non-obvious is usually what the books don’t cover. To find it, you need to examine millions of possibilities in the right order, following exact steps throughout. You will also need to be down-to-earth and have the modesty and objectivity to uncover the truth behind each step, rather than taking short-cuts and missing out on the whole picture. And accompanying all this are open- mindedness and the desire to challenge the impossible. You have been characterized as a very good and efficient writer of research papers and proposals. What are the tricks? Respect the reader. Before putting pen to paper, I contemplate what I want my readers to gain from my article. Professor Lo required us to write in a way that layman readers would comprehend and find instantly interesting. I place a lot on an article’s underlying logic, striving for accessibility in the presentation of difficult concepts. It also has to be well written. I’d like my readers to give me a standing ovation after reading, as if it were a wonderful operatic performance. Grant proposals should be clear, to-the-point and concise, allowing the judging panel to grasp the main points and the value of the research within limited time. We all know you are an excellent researcher. How would you describe yourself as a teacher and a mother? I give my all to every class I teach. Whether my students are professionals, graduate students or undergraduates, I would assess their standards and expectations, and ponder how to enable the most important information to make the deepest impression within the duration of the class. I adjust my teaching materials according to the students I have. During class, I watch their reaction; after class, I assess myself. Work is important, but it is finite. Family is eternal. My daughters are a crucial part of my life. I would not let my work eclipse my duties as a mother. My daughters appreciate and respect my work, and we’re close. My active participation in the parents’ association and school activities has led people to mistake me for being a full-time mom. 請掃描QR碼閱讀全文版 Scan the QR code for the full version Photos of Prof. Rossa Chiu in this issue by Cheung Wai-lok