Newsletter No. 419

12 No. 419, 4.6.2013 赵慧君教授 化学病理学系 请给读者说一下目前做的研究好吗? 主力研究是分析人的血液样本所含的林林总总的DNA物质,扩大 血液测试的应用范围,以代替抽取活检样本的较高风险检查。传 统认知是必须抽取器官组织才可做DNA诊断,但原来人体细胞 因新陈代谢或疾病而坏死的时候,其新陈代谢物会浮在血浆里。  卢煜明 教授在1997年证实孕妇的血液含有胎盘的新陈代谢物,从 而可化验出胎儿的DNA。此后十多年进度惊人,2008年发展出唐 氏综合症无创产前检测,2010年,我们已可利用母体血液样本中 微量的胎儿DNA,排列出胎儿的完整基因图谱,理论上可以检测 出任何遗传病。目前,我们已能透过血液样本重整出肝癌、乳癌和 卵巢癌等细胞的基因图谱,目标是发展出应用范围广泛、可频密进 行的无创癌症检查,侦测所有基因异变。 就安洁莉娜  • 裘莉主动接受乳房组织切除手术引起的广泛 回响,你认为医生对考虑这类「预防性」手术的人士应给予 什么忠告? 安洁莉娜  • 裘莉 的病例和手术并不新鲜,她了不起之处是公开自 己的决定和手术过程,提高大众对基因诊断的认知,凸显医生在 这方面应有的专业操守:一、对基因疾病应有丰富认识;乳癌是 女性头号杀手之一,大概百分之十由家族遗传的BRCA 1 基因病变 引起。有这种基因病变的人,在七十岁之前乳癌和卵巢癌的发病 率分别是八成和四成。医生有责任向有家族乳癌病例的病人介 绍BRCA 1 检测。二、充分辅导,清晰解释检测局限,以及各种检测 结果所牵涉的应对方法,譬如结果属阳性,家庭成员也将面临检 测的压力。三、细陈利弊;解释动手术可降低患癌风险的程度、手 术过程及日后对身心的潜在影响,让病人有足够的资讯权衡是否 接受检测和手术。 你如何看基因检测所引起的道德争议? 基因诊断如同任何新科技一样,都会带出新问题和令部分人不安, 只要有足够的认知,有效善用,是无需担心的。在健全的医学体制 里,例如在香港,所有医学检测须由医生转介,也需经过筛选,例 如针对可治疗的遗传疾病,或有高危家族史的疾病如地中海贫血 症。医生得严格把关,确保没有不当使用检测技术,以及正确解读 检测结果。 你获得杨孟思教授赏识,走上研究之路。如果要物色徒弟 或接班人,会侧重什么质素? 先决条件是热诚,有渴望服务社会作出改变的心,否则难以在争 分夺秒的世界研究平台上突围而出。其次是逻辑思考;做研究着眼 点不在于显而在于隐,但隐而未发的往往是书本知识所不及揭示 之处,得靠蛛丝马迹在千万种可能性中依次发掘,每一步骤都精 密非常。第三是脚踏实地,虚心挖掘每一步骤背后的真理,不能诉 诸主观略过某些步骤,否则便难窥全豹,但循序渐进之余又得保 持思想开明,向不可能挑战。 都说你擅长写研究论文和建议书,个中有什么窍门? 尊重读者─在写每一篇文章前,我必谨慎斟酌要让读者有什么得 着。卢教授对我们的要求是一下笔便要令专业以外的读者也能明 白论述范畴,同时锁定其注意力,引起探索的兴味。我注重上文下 理的逻辑思维,力求深入浅出而带文采,令人阅后击节赞赏,就像 看完歌剧站起来大声喝采!研究经费申请书尤其要言简意赅,提 纲挈领,让评审人员在有限的宝贵时间内,迅速掌握研究重点和 价值所在,欣赏认同而批出款项。 众所周知你是位出色的研究人员,你如何评价自己当教师 和母亲的表现? 每教一课,我都全力以赴。无论教的是专业人士、研究生还是本科 生,我定会先估量学生的平均水平和期望,筹算在有限的课时里把 最重要的信息深印于他们的脑海。我的教材因应受众而微调,不 会一成不变。施教时我时刻留意学生的反应,下课后自我评估,力 求改善。我重视工作,但工作是有尽期的,家人是永远的,女儿是 我生命中很重要的部分,我不会让工作侵蚀我当母亲的角色。女儿 欣赏和尊重我的工作,和我的关系也很亲 厚。我参与家长会和学校活动的频密程度 曾令人误会我是全职妈妈呢。 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. 请扫描QR码阅读全文版 Scan the QR code for the full version Photos of Prof. Rossa Chiu in this issue by Cheung Wai-lok

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