问题 问答题 案例分析题

1992年3月16日,某社区约40名村民由于曾经参与卖血,当地疾病预防控制中心怀疑该群体中有村民已经是艾滋病患者,紧急通知该群体进行血液检测。

采集可疑血样的操作、贮藏和运输过程中的注意要点?

答案

参考答案:

采集可疑血样的操作、贮藏和运输过程中的注意要点。

(1)若进行HIV抗体、抗原检测,常用的样本是血清或血浆。

1)血清样品采集和处理:用一次性注射器或真空采血管抽取3~5ml静脉血,室温放置1~2小时,待血液凝固、血块收缩后再离心,尽可能地吸出血清备用。

2)血浆样品采集和处理:抗凝剂最常用的是K2EDTA,用一次性注射器抽取3~5ml静脉血,转移至加有抗凝剂的试管,或直接用加有抗凝剂的真空采血管,反复轻摇,室温放置,血浆和血细胞会分层,尽可能地吸出血浆备用。

3)送检要求:经HIV初筛实验室进行初筛检测后,若需上送的样品,只送血清或血浆,标本量要求达到1ml,最少不能低于0.7ml,不符合要求的标本将可能被拒收。标本用螺口的血清管装,在管外标记好病人姓名;每份标本需填写"HIV复检送检单",表格内资料要填写齐全,送检时与标本分开放置。

应采用WHO提出的三级包装系统:第一层容器:装样品,要求防渗漏。样品应置于带盖的试管内,试管上应有明显的标记,标明样品的编号或受检者姓名、种类和采集时间。在试管的周围应垫有缓冲吸水材料,以免碰碎。随样品应附有送检单,送检单应与样品分开放置。第二层容器:要求耐受性好、防渗漏、容纳并保护第一层容器,可以装若干个第一层容器。将试管装入专用带盖的容器内,容器的材料要易于消毒处理。第三层容器:放在一个运输用外层包装内,应易于消毒。在第三层容器外面要贴标签(数量,收、发件人)。

(2)若进行HIV核酸定性检测最常用的是血清、血浆或血细胞。

1)血清样品采集和处理:同上述血清样品采集和处理。

2)血浆和血细胞样品采集和处理:抗凝剂最常用的是K2EDTA,采集的抗凝血应在4~8小时内分离PBMC和血浆,否则应在24~48小时内分离血浆和血细胞。

3)样品的运送和保存:4℃冷冻送检采集的抗凝全血,采集后务必在24小时内送到目的实验室。分离出的血清、血浆、血细胞、PBMC均立即放入﹣80℃冰箱备用。样品的包装采用WHO提出的三级包装系统。

(3)若进行HIV核酸定量(病毒载量)测定最常用的是血浆:

1)抗凝剂的选择:不同病毒载量检测方法选用不同的抗凝剂,最通用的是K2EDTA。

2)血浆样品采集和处理:同上。

3)样品的运送和保存:同上。

(4)若进行CD4+和CD8+T淋巴细胞检测使用的样品是抗凝全血。

1)抗凝剂的选择:最常用的是K2EDTA。

2)抗凝全血的采集:用一次性注射器抽取3~5ml静脉血,转移至加有抗凝剂的试管,或直接用加有抗凝剂的真空采血管,采血后立即握住试管两端颠倒混匀数次,将血液与抗凝剂充分混匀,以防止凝固,但用力不可太猛,避免溶血。

3)样品的运送和保存:尽可能快地在24小时内将样品送至目的实验室。在室温(18~23℃)下保存和运送样品,避免过冷和过热,一般春、秋、冬季无需冷藏,天气太热时,需要用一个隔热的容器装样品,并且把这个容器放于另一个有冰袋和吸热物质的容器中。样品的包装采用WHO提出的三级包装系统。

选择题
单项选择题

Questions 21~25


While other members of my team explored the wreck of a small Greek merchant ship that sank off the Turkish coast more than 2,400 years ago, I hovered above them in a submarine. One diver, an archaeologist, placed an amphora, or two-handled jar, inside a lifting basket. Another vacuumed sediment from the site by fanning sand into the mouth of a nearly vertical pipe. Two more were taking measurements, carefully, but of necessity quickly, for at this depth each diver had only 20 minutes to complete the morning’s assigned task. Any longer, and they would require lengthy medical treatment, to avoid the divers’ ailment known as the bends.
In four decades of diving on shipwrecks, I’ d been too engrossed in carrying out similar tasks to think of the families whose loved ones may have disappeared long ago. I had always concentrated on the technical features of my trade. I had stopped diving regularly 15 years before this exploration, turning over the bulk of the underwater work to a younger generation, but I continue to make inspection dives on most wrecks we excavate.
This was not just any wreck. Although I’ve been involved in uncovering the remains of much older ships, and of more than a hundred ancient shipwrecks along the Turkish coast. I had never even seen a wreck from the fifth century BC. Preliminary photographs of the cargo dated it to the third quarter of the century, during the Golden Age of classical Greece. Athens, then as now the major city in Greece, controlled an empire stretching from one side of the Aegean Sea to the other. None of this would have been possible without naval might and maritime commerce.
During our three-year exploration of the wreck we excavated examples of nearly every type of jar that the classical Greeks made for wine or water. Many types might have been used as tableware by the ship’s crew, but they were far in excess of what would have been required. We concluded therefore that they must have been cargo. We also discovered in the seabed two marble discs, which we guessed were the ship’s eyes. It has long been known from vase paintings that classical Greek ships—like those from other cultures—had eyes to give them life or help them see their way through the waves. Although warships were known to have had naturalistic marble eyes attached to them, most scholars assumed that the eyes on more modest merchant ships were depicted as simple circles painted onto the sides of the vessel.
Did the sailors who depended on these eyes for safety survive the ship’s last voyage They could have lived through the actual sinking. The ship was less than a hundred yards from land when it sank, so they might have swum towards the shore. And we know from Greek literature that some ships had lifeboats. But proximity to land and having lifeboats are no guarantee of safety. Even if some had swum to shore, it’s hard to imagine that many managed to crawl up on the exposed and sharp rocks while being smashed by waves like those that almost certainly sank their ship.

What does the writer suggest about himself in the second paragraph ______

A. He had developed every skill that was needed for exploring wrecks.
B. He had benefited by changing his role in explorations.
C. He was pleased he had started training younger divers.
D. He was aware he distanced himself from aspects of his work.