时间:2019-01-13 作者:英语课 分类:VOA标准英语2010年(四)月


英语课

Joe DeCapua 15 April 2010




Over the years, there’s been debate over when to start HIV-positive patients on anti-retroviral drugs, or ARVs.  At first the standard practice was to wait until a person’s immune system had nearly collapsed 1.  But a growing body of research shows there may be many benefits to starting treatment much earlier.


 


Measuring the number of CD4 immune cells is a major determining factor on when to begin drug treatment.  It was the norm to give ARVs to people who either had full-blown AIDS or had CD4 counts below 200.


Now it’s generally accepted that anti-retrovirals should be given when the count drops below 350.  But there’s debate over whether to start treatment even earlier than that.




Dr. Roy Gulick, Weill-Cornell Medical Center


The subject was discussed at the recent OPMAN XVIII, the Optimal 2 Management of HIV Disease Conference. 


Dr. Roy Gulick, professor of medicine at the Weill-Cornell Medical Center in New York City, says, “It’s ironic 3 that 23 years now into anti-retroviral therapy we are still asking a very basic question.  And that is, when should we start?”


Pros 4 and cons 5


Gulick outlines a few reasons for starting anti-retroviral treatment early.


“We know that our treatment decreases viral load levels and thus the emergence 6 of (drug) resistance and also increases CD4 cell counts and general immune function.  We have published data to show that our best regimens can suppress viral load levels for up to seven years or longer,” he says


What’s more, he says, “Treatment likely reduces transmission in the community.  That is, treatment can be prevention.”


Starting earlier may also be more cost effective.


Some of the reasons for delaying treatment have included the inconvenience and toxicity 8 of anti-retrovirals and their long-term side effects. 


“On balance, up until recently, we have elected to wait to start.  But there is a lot of data, newer data, to suggest that the balance of this question is likely shifting,” he says.


There had been general agreement that ARV treatment should be started for anyone with AIDS, symptomatic HIV disease or CD4 counts less than 200.


But there’s now agreement on a second group with a higher count.


“That is asymptomatic with CD4s between 200 and 350.  The developed country guidelines all changed to a firm yes in 2008.  And the newest guidelines to now suggest this are the WHO (World Health Organization) ’09 guidelines, which now say, yes, we should be treating anyone with HIV disease, regardless of symptoms, with a CD4 (count) less than 350,” he says.


A study in Haiti helped persuade the World Health Organization to recommend starting treatment earlier.  Fewer deaths and infections were found in those who received ARVs sooner.  Besides a drop in mortality, earlier treatment resulted in fewer tuberculosis 9 cases among patients.


“This was the data that caught the eye of the WHO and really the world and said that we should be starting earlier throughout the world,” he says.


Gulick says the shift to earlier treatment is also due, in part, to “easier, less toxic 7 and more potent 10 therapy.”


He says, “So we go from handfuls of 20 plus pills taken three times daily to as few as one pill once a day.”


 


There are also the findings of many cohort studies to support earlier treatment. The findings are based on thousands of HIV patients, whose progress was followed in clinics.


In 2002, in one study, no difference was seen in those receiving treatment when their CD4 counts were between 200 and 350 and those who started treatment when their counts were over 350.  At least that was the case after comparing the two groups over a three-year period.


“Although there’s no difference at three years,” he says, “at five years, this now reaches statistical 11 significance.  So, there was a benefit to starting earlier in this cohort study.  And it took over three years, more like five years, to convincingly show the clinical benefit here.”


Proof enough?


The professor of medicine asks if the results appear good for those receiving treatment at this stage, why not start even earlier? In other words, a CD4 count above 350.  Some cohort studies seem to support this, but Gulick says those studies are not always enough to go on.


“Well, what’s the problem with all the data I’ve shown you so far?  And that is it’s not randomized clinical trial data.  These are cohort patients.  That is, general patients followed in clinics,” he says.


And these patients may be different.


“It’s safe to say that patients who elect to start ART (anti-retroviral therapy) with high CD4s may not be the same as patients who defer 12 ART with the same high CD4s,” he says.


Those who choose to start treatment sooner may have better health habits. 


“They may use seatbelts more.  They may exercise more.  There may be other confounding reasons why they have general better health than the group who elects to defer.  So we have to take all this cohort data somewhat with a grain of salt,” Gulick says.


And some cohort studies found starting treatment at a much higher 450 to 550 CD4 count showed no significant benefits.


To try to settle the issue, a formal clinical study – the Start study – is now underway.  It’s enrolled 13 patients with CD4 counts higher than 500.  The study could finally determine whether it’s more beneficial to start treatment immediately or wait until CD4s drop below 350, the current standard.  However, the results may not be known for six years. 


Some say the there’s enough data from the cohort studies to not wait for the Start study results. 


 



adj.倒塌的
  • Jack collapsed in agony on the floor. 杰克十分痛苦地瘫倒在地板上。
  • The roof collapsed under the weight of snow. 房顶在雪的重压下突然坍塌下来。
adj.最适宜的;最理想的;最令人满意的
  • What is the optimal mix of private and public property rights in natural resources?私人和国家的自然资源产权的最适宜的组合是什么?
  • Optimal path planning is a key link for the sailing contest.帆船最优行驶路径规划是帆船比赛取胜的关键环节。
adj.讽刺的,有讽刺意味的,出乎意料的
  • That is a summary and ironic end.那是一个具有概括性和讽刺意味的结局。
  • People used to call me Mr Popularity at high school,but they were being ironic.人们中学时常把我称作“万人迷先生”,但他们是在挖苦我。
abbr.prosecuting 起诉;prosecutor 起诉人;professionals 自由职业者;proscenium (舞台)前部n.赞成的意见( pro的名词复数 );赞成的理由;抵偿物;交换物
  • The pros and cons cancel out. 正反两种意见抵消。 来自《现代英汉综合大词典》
  • We should hear all the pros and cons of the matter before we make a decision. 我们在对这事做出决定之前,应该先听取正反两方面的意见。 来自《简明英汉词典》
n.欺骗,骗局( con的名词复数 )v.诈骗,哄骗( con的第三人称单数 )
  • The pros and cons cancel out. 正反两种意见抵消。 来自《现代英汉综合大词典》
  • We should hear all the pros and cons of the matter before we make a decision. 我们在对这事做出决定之前,应该先听取正反两方面的意见。 来自《简明英汉词典》
n.浮现,显现,出现,(植物)突出体
  • The last decade saw the emergence of a dynamic economy.最近10年见证了经济增长的姿态。
  • Language emerges and develops with the emergence and development of society.语言是随着社会的产生而产生,随着社会的发展而发展的。
adj.有毒的,因中毒引起的
  • The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
  • There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。
n.毒性,毒力
  • The hoarse grunt or squeal is characteristic of toxicity.嘶哑的哼声和叫声是中毒的特征。
  • Dieldrin is related to aldrin,and its toxicity to earthworms is similar.狄氏剂与艾氏剂有关,对蚯蚓的毒性是相似的。
n.结核病,肺结核
  • People used to go to special health spring to recover from tuberculosis.人们常去温泉疗养胜地治疗肺结核。
  • Tuberculosis is a curable disease.肺结核是一种可治愈的病。
adj.强有力的,有权势的;有效力的
  • The medicine had a potent effect on your disease.这药物对你的病疗效很大。
  • We must account of his potent influence.我们必须考虑他的强有力的影响。
adj.统计的,统计学的
  • He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
  • They're making detailed statistical analysis.他们正在做具体的统计分析。
vt.推迟,拖延;vi.(to)遵从,听从,服从
  • We wish to defer our decision until next week.我们希望推迟到下星期再作出决定。
  • We will defer to whatever the committee decides.我们遵从委员会作出的任何决定。
adj.入学登记了的v.[亦作enrol]( enroll的过去式和过去分词 );登记,招收,使入伍(或入会、入学等),参加,成为成员;记入名册;卷起,包起
  • They have been studying hard from the moment they enrolled. 从入学时起,他们就一直努力学习。 来自《简明英汉词典》
  • He enrolled with an employment agency for a teaching position. 他在职业介绍所登了记以谋求一个教师的职位。 来自《简明英汉词典》
学英语单词
.bgl
acrobatic feat
ad-libbers
agsim
alkylglycerol
amorosity
an index of the mind
aneurysmal murmur
Atcotibine
audiotron
average confidence interval
axial sub-slot
calcium aluminium silicon alloys
capillary-ejectal (pele's hair)
coeliac lymph gland
column boiler
complete elliptic integral of the second kind
complete transduction
controlled environment chamber
Corydalis tianshanica
cracking in various media
cutbirth
deep drawing sheet
dreamcoats
Dürmentingen
Dīdīga Hāyk'
economic-reform
edmintons
electromagnetic resonator
envelope card
fafiated
formation of lots
fresh air louvers
GRCT
had a good time
HIVIP
hull specification
icosahedral virus
indented form
intel 8008
isomorphism of sheaves
jato release cylinder
life appointment
llantarnam
long johnss
Lplipoprotein
Lucky Country
Lutetian Stage
magnetic excitation
mainframe on-line test
methane triacetic acid
metritic synovitis
Monday Club
one-man rules
organic sludge
pacaya
parallel-laid web
path test
pitch length
pituitary diverticulum
plasma disc
plateau T wave
preterm infant
proagglutinoid
program out hub
propiophenone
prunus davidiana var.alba bean
psilocephala frontata
pSM19035
pyrimidinic
pyrolysis of coal
quasi-equilibrium
quickcuff
sedimentary cycle in coal-bearing series
short-term goal
Slavnoye
solvolytic dissociation
standard gauge
sulphadimidine
sunfang
support a family
svt
tana-lake
tchobanoglous
tchotchkes
that
touch bases
trade status
truncated cone-shaped
two tier system
two-timers
uninterestingness
unpark
upgrown
validity stamp
vart
vertical component seismograph
Victoria Falls
Viola rupestris
weakly signal
welder's mark No.
yuccas