Episode 2 - Scrape wound
第二集：擦傷


角色介紹
Platelet
血小板

When I started this, I had figured that the logical progression would be RBC > neutrophil > platelet, but it's pretty clear the platelet is the star of this episode (not to mention a fan favourite), and so merits next discussion.
剛開(kāi)始時(shí)，我還以為這番應(yīng)該按 紅細(xì)胞 --> 中性粒細(xì)胞 -->血小板 的順序來(lái)介紹。但這集的主角明顯是血小板嘛 (人活著就是為了血小板)，所以接下來(lái)介紹它們。

The platelet is the smallest cell in the human body--that is, if we were to even consider it a cell. Platelets are actually cellular fragments that mature and break off of the very large precursor, the megakaryocyte. They are extremely small--2 to 3 microns in diameters--and have a relatively simple structure. Like the RBC, they have no nucleus, which means they have no regenerative potential. Normal humans should have 150-450 thousand per microliter of blood, or around 0.5-2.5 trillion in total.
血小板是人體里最小的細(xì)胞，如果你還把它當(dāng)細(xì)胞的話。血小板其實(shí)是細(xì)胞殘余，它從它的前身，一個(gè)超級(jí)大的細(xì)胞“巨核細(xì)胞”中脫落下來(lái)。它們超級(jí)小，直徑2-3微米，結(jié)構(gòu)比較簡(jiǎn)單。像紅血球一樣，它們也沒(méi)有細(xì)胞核，也就是無(wú)法再生。一微升的血液里有15-45萬(wàn)個(gè)血小板，也就是，人體里大概有5000億~2.5萬(wàn)億個(gè)血小板。


The platelet's primary (actually, sole) function is to trigger hemostasis, or clotting. Hemostasis is an extremely complex and highly regulated process with many different moving parts and players. To briefly summarize it, platelets circulate in the blood stream, happily rolling along until they encounter a damaged vessel. Instead of the normal smooth vascular endothelium, they come into contact with exposed subendothelial collagen and von Willebrand factor.
血小板的主要（唯一）作用是止血。止血過(guò)程非常復(fù)雜，需要好多玩意兒一起協(xié)調(diào)管理。簡(jiǎn)單來(lái)說(shuō)，血小板在血液中流動(dòng)，碰到破損的血管就會(huì)停下來(lái)。它們不接觸平滑的血管內(nèi)皮，而是與暴露出的?內(nèi)皮下膠原?和'血管假性血友病因子'(von Willebrand factor)結(jié)合。


Platelets express receptors that help them bind to this substrate (glycoprotein 1b complex, or GP1b). Once bound, they become activated, secreting numerous chemical substances from either alpha granules or dense granules. These substances include proteins that bind more platelets and small molecules cause more activation (examples: calcium, thromboxane-A2, and ADP). Importantly, the use of an NSAID poisons platelets, stopping them from producing thromboxane-A2, and impairing their function. This is (one of many) reasons a patient at risk of cardiovascular disease may take a daily aspirin.
血小板產(chǎn)生受體，幫它們和底物GP1b結(jié)合（糖蛋白1b復(fù)合物）。一旦結(jié)合，血小板就會(huì)活化，從'α顆粒體'和'致密顆粒'中分泌出一系列化學(xué)物質(zhì)。這些東西包括，可以粘上更多血小板的蛋白質(zhì)，以及導(dǎo)致它更加活化的小分子(比如，鈣離子，血栓素A2，ADP)。阿司匹林等抗炎藥會(huì)毒害血小板，不讓它們產(chǎn)生血栓素。這就是為什么心血管病病人，每天可能得吃片阿司匹林。

And recall that since the platelet has no regenerative potential, there is naught to do but wait for the platelet to be eliminated and replaced with unpoisoned platelets (their lifespan is around 7 days). You may have a relative whose surgery was deferred for a week for such a reason, as it increases the risk of bleeding. The activated platelets express another receptor, glycoprotein IIb/IIIa, which allows them to bind other platelets by linking through a molecule called fibrinogen, which is produced by the liver and floats in the circulating plasma. The platelets and fibrinogen constitute a "platelet plug"--this is the process of primary hemostasis.

還記得吧，血小板不可自我再生。所以，我們只能等著中毒的血小板被清理走，換成健康的血小板（血小板存活天數(shù)：大約7天）。手術(shù)就可能因此推遲一周，因?yàn)?strong>中毒的血小板會(huì)導(dǎo)致大出血?；罨难“暹€有另一個(gè)受體，糖蛋白IIb/IIIa, 它讓血小板通過(guò)‘纖維蛋白原’（從肝臟產(chǎn)生）和其他的血小板伙伴們結(jié)合?！“濉汀w維蛋白原’組成了‘血小板栓’ - 就是初期止血的過(guò)程。

A platelet plug is not very sturdy, however, and maturation of the plug requires the effect of coagulation factors, more soluble proteins usually made in the liver. This process is kind of complicated, so let's not get into it. What results is the enzymatic cleavage of fibrinogen into mature fibrin, which is much more sturdy. This is the process of secondary hemostasis.
但是，血小板栓不太結(jié)實(shí)。成熟的‘血小板栓’，需要一種更可溶的蛋白質(zhì)，凝血因子（通常在肝臟產(chǎn)生）。這個(gè)過(guò)程比較復(fù)雜，就不細(xì)說(shuō)了。結(jié)果就是，‘纖維蛋白原’分開(kāi)，變成更結(jié)實(shí)的‘血纖蛋白’。這是第二期止血過(guò)程。

A few other random thoughts about platelets: There are many diseases that involve platelets (and hemostasis more broadly), whether through inherited defect (Von Willebrand disease, Glanzmann's thrombasthenia, Bernard-Soulier disease) or acquired malfunction (DIC, TTP, ITP, PTP). Unclear if these will come up.. What you should take away is that the platelet initiates and largely controls clotting. I don't have anything insightful to say about their character design, however. The hat, boots, and oversized shirt are not immediately reminiscent of platelet cytomorphology. Their blue theme is probably also stylistic.

再隨便聊聊血小板。血小板和很多疾病有關(guān)，有的原因是基因缺陷（血友病，血小板無(wú)力癥，巨大血小板綜合癥），有的是后天缺陷（DIC, TTP, ITP, PTP）。不知道以后會(huì)不會(huì)提到這些……現(xiàn)在記得血小板啟動(dòng)、并且控制止血就好。對(duì)于血小板的角色設(shè)計(jì)，我沒(méi)什么好說(shuō)的。帽子，鞋，還有大T-shirt和血小板細(xì)胞本身的造型沒(méi)什么關(guān)系。它們身上的藍(lán)色也估計(jì)是為了造型。

Episode 2 - Scrape wound
第二集 - 擦傷

Intro: A scrape wound, or "abrasion" in typical doctor-speak, is a superficial injury sustained to the epidermis. These injuries can bleed and be painful, but usually do not require special intervention or treatment beyond being kept clean and can resolve by themselves, as we shall see.
擦傷，是表皮上產(chǎn)生的表面?zhèn)?。傷口可能?huì)流血，疼痛，但除了保持傷口清潔之外，并不需要特別處理。如之后所見(jiàn)，它會(huì)自愈。

Our protagonist RBC, AE-3806 is on a delivery trip to drop off some nutrients. Capillary 34?! Try 3.4 billion!?No wonder she's always getting lost.?

AE-3806在搞快遞，輸送營(yíng)養(yǎng)。毛細(xì)管34？！應(yīng)該是34億才對(duì)！怪不得她總迷路。

A note on the nutrients that came up last time: Red blood cells do not generally carry nutrients. They do contain some amount of sugar and amino acids, and their lipid membranes do constitute some usable energy, but by and large "food" is dissolved in plasma. Glucose (the most readily usable energy source for any organ, and especially preferred by nervous tissue and RBCs) is directly dissolved. Amino acids too, if I recall correctly. Lipids tend to be transported in small protein-bound particles (lipoproteins), as their nonpolar nature precludes direct dissolution in plasma, which is aqueous. See?

上回說(shuō)過(guò)，紅細(xì)胞一般不輸送營(yíng)養(yǎng)。它們的確含糖以及氨基酸，它們的磷脂雙分子層（細(xì)胞膜上的）里也有可用的能量，但大部分情況下，“食物”溶解在血漿里。葡萄糖（最容易被利用的能源，神經(jīng)組織和紅細(xì)胞的最愛(ài)）會(huì)直接溶解到血里。印象里氨基酸也可以溶解。磷脂會(huì)由脂蛋白運(yùn)送，因?yàn)樗鼈兎菢O性（不溶于水），不會(huì)直接溶解在水性的血漿里。

A bunch of platelets are transporting...something. We'll learn what later. They have some trouble getting down some stairs--this does not represent any physiologic process to me, probably it's just them being cute. Hopefully a gaggle of platelets moving in a group does not represent a thrombus (clot), that would not be something you'd want floating around...
一群血小板在運(yùn)送個(gè)……啥？后面我們就知道了。他們下臺(tái)階不太順利，這和生理過(guò)程沒(méi)啥關(guān)系，就是為了賣萌吧。血小板這么聚集在一起，希望這并不代表血栓，誰(shuí)都不想讓那玩意動(dòng)來(lái)動(dòng)去??！

Oh, the big package is fibrin. Well, it's probably fibrinogen, as used fibrin cannot be "recycled" but is instead digested by a series of fibrinolytic enzymes expressed by endothelial cells. These enzymes have been reverse-engineered by us to be used as "clot busters" in stroke and heart attack patients.
哦呀，大箱子里是“血纖蛋白”。其實(shí)應(yīng)該是“纖維蛋白原”吧，因?yàn)橛眠^(guò)的“血纖蛋白”不能回收，而是會(huì)被內(nèi)皮上分泌的一系列“ 纖維蛋白溶解酶”消化掉。我們也可以反過(guò)來(lái)利用這些酶，‘捅開(kāi)’中風(fēng)或心臟病人的血栓。

AE3803 and her senpai travel to a superficial vessel in the skin. To briefly summarize, the skin is one large, continuous epithelial lining which functions in thermoregulation, in sensation, but most importantly as a barrier to the external environment. If you were to lose your skin (say, suffer a severe burn), you will find that it becomes difficult to impossible to regulate your internal environment, not to mention inviting a bunch of foreign invaders, as we shall see...
AE3803和紅血球前輩在皮膚表層的血管走動(dòng)。簡(jiǎn)單來(lái)說(shuō)，皮膚是一大片連續(xù)的上皮層，它控制溫度、感知，但最重要的是，它隔離了外界。如果你沒(méi)了皮膚（比如嚴(yán)重?zé)齻蜁?huì)發(fā)現(xiàn)很難、或者不可能調(diào)節(jié)身體內(nèi)部環(huán)境，而且還會(huì)讓外敵入侵，我們待會(huì)就看到了……

Oops, giant scrape wound. We better get used to AE3803 being helpless and saved a lot, as erythrocytes truly do not have any sort of defense mechanisms. In typical fashion, U-1146 is one of the first responders.
呀哈，好大的傷口。我們也該習(xí)慣AE3803弱小可憐又無(wú)助了，因?yàn)榧t細(xì)胞真的沒(méi)有任何的防御機(jī)制。按套路，U-1146又是第一個(gè)回應(yīng)的。

Invasion! We get a glimpse of some new bacteria. I can't begin to identify all of them without some additional cues, but we will get to look at a couple in depth here.
入侵警告！我們看到了一些新細(xì)菌。我不能一一辨認(rèn)，但會(huì)仔細(xì)說(shuō)下其中幾個(gè)細(xì)菌。

Staphylococcus Aureus

金黃色葡萄球菌

Staphylococcus Aureus is one of the most common human pathogens. It, like most staph and strep species, is a skin commensal--that is, it normally lives on the surface of your skin, not causing any problems unless it is introduced into a wound. The design of this character gives it away immediately; staph aureus is known for producing a pigment that gives it a bright golden color, staphyloxanthin (Staph aureus, from the latin "aurum" meaning gold). Also notice the clusters of, uhh, balls on her. This is an allusion to its tendency to form "clusters" in culture. It also causes a huge number of diseases and expresses a wide variety of virulence factors. It can cause skin infections (cellulitis), pneumonia, endocarditis, really it can **** with any organ it gets into. And alarmingly, it is resistant to a number of antibiotics, a number that is steadily growing.
金黃色葡萄球菌是最常見(jiàn)的一種人類病原體。像大部分的葡萄球菌和鏈球菌一樣，它一般活在皮膚表面。一般來(lái)說(shuō)，它不會(huì)造成任何問(wèn)題，除非——你有了傷口。它的人設(shè)非常有特點(diǎn)，讓人一眼就知道是它?！瘘S色葡萄球菌’會(huì)產(chǎn)生一種染料，讓它變成金黃色(金黃色葡萄球菌的英文是Staph aureus, aureus就是拉丁語(yǔ)的‘金子’，所以化學(xué)符號(hào)Au也代表‘金’)。還有注意它那一串串的……嗯……球球。這代表它在培養(yǎng)液里容易形成“菌落”。它也會(huì)造成許許多多的疾病。它能導(dǎo)致皮膚炎（蜂窩組織炎），肺炎，心內(nèi)膜炎，基本上能搞壞任何它接觸的器官。更可怕的是，它對(duì)一些消炎藥有抗藥性，并且抗藥的種類越來(lái)越多。

Streptococcus Pyogenes
釀膿鏈球菌

Streptococcus Pyogenes is another common skin commensal related to our friend pneumococcus. It too is gram-positive, though this guy is not blue. Maybe my old theory should be tossed. Like staph aureus, it can cause all manner of infection, though the one you are probably most familiar with is strep throat. We have some visual cues again; the "balls" are arranged in chains this time, reflecting its tendency to form chains in culture.

釀膿鏈球菌是另一種常見(jiàn)的皮膚上的細(xì)菌，它和之前的肺炎球菌也有關(guān)系。它也是革蘭氏陽(yáng)性，雖然這家伙并不是藍(lán)色的。也許我之前的理論不對(duì)。和金黃色葡萄球菌一樣，它也可以引起各種感染，但你們最熟悉的應(yīng)該是它引起的咽喉炎。他的人設(shè)也是有道理的；他身上的“球”排成一串，是因?yàn)樗菀自谂囵B(yǎng)液里形成‘串’。

Pseudomonas Aeruginosa
綠膿桿菌

Pseudomonas Aeruginosa is another very common bug. This one is, to my knowledge, not a typical skin commensal, but it is ubiquitous in the environment, in soil, etc. Unlike all of the other bugs so far, it is a gram-negative rod, and this guy's green color is due to a pigment involved in binding iron (pyocyanins, pyoverdin). It too can cause a huge variety of infections, and can be notoriously resistant to antibiotics. It also has a distinctive, uh, "grapey" odor.

綠膿桿菌也是個(gè)常見(jiàn)的細(xì)菌。不過(guò)據(jù)我所知，它在皮膚上不常見(jiàn)，但是它在外界環(huán)境里到處都有，比如土壤里就有。和其他的幾位不一樣，它是革蘭氏陰性。這家伙是綠色的，因?yàn)樗丸F結(jié)合就綠了（綠膿青素）。它也可以引起一大堆感染，也對(duì)消炎藥有抗藥性。它還有很特別的“葡萄味”。

The vessels are constricting. This is a normal reflexive process with any sort of vascular damage to minimize blood loss, and its driven by both neural impulse (though someone may wanna check me on that) and chemicals like endothelin.

血管在收縮。這是正常條件反射，血管受損時(shí)，這樣可以減少流血量。收縮由神經(jīng)信號(hào)以及化學(xué)物質(zhì)（如內(nèi)皮素）引起。

Damn valve. We've already been over them (Ep. 1).
又是靜脈瓣。第一集里說(shuō)過(guò)了。

Lmao neutrophils back on the scene. I wanted to point this out last episode, but if the neuts seem single-minded in their pursuit of bacteria, it's because they are. They are actually quite "dumb" and just move towards any foreign antigen and try to eat or kill it.

媽媽咪呀，中性粒細(xì)胞又回來(lái)了。這些中性粒細(xì)胞追細(xì)菌時(shí)非常一根筋，這是因?yàn)樗麄兙褪穷^腦簡(jiǎn)單。它們蠻傻的，只會(huì)沖向外來(lái)抗原，要么吃掉它們，要么殺掉它們。

Oh, I forgot to describe the process of neutrophil diapedesis earlier. A detailed explanation can wait until I do the neutrophil character highlight, but briefly: In order to reach their target tissues, neutrophils have adhesion molecules that allow them to cling to vascular endothelium and squeeze between them (transmigration). L-selectin is a protein that allows them to bind...I'm not actually sure what specifically ("sulfatides and sulfated polysaccharides", apparently).

忘了說(shuō)“中性粒細(xì)胞滲出”了。詳細(xì)的等‘中性粒細(xì)胞’做主角時(shí)再講，簡(jiǎn)單來(lái)說(shuō)就是，為了貼近目標(biāo)，中性粒細(xì)胞身上有粘合性的分子，把它們粘在血管內(nèi)皮上，然后再?gòu)膬?nèi)皮之間擠過(guò)去。蛋白質(zhì)‘L-選擇素’就可以讓中性粒細(xì)胞和‘硫脂類’和‘硫酸多糖類’結(jié)合。
這個(gè)滲出過(guò)程后面有表現(xiàn)，我先貼這兒了。

I don't agree with Staph Aureus's assessment that by overcoming local neutrophil response that she'll be able to sneak right on through. A localized infection takes hold, but you can bet that as long as there are still foreign peptides and inflammatory cytokines, the immune system will keep sending soldiers.
我不同意金葡菌的分析，啥？沖破了中性粒細(xì)胞的防線就能入侵進(jìn)去？感染目前只在一小片區(qū)域，但只要有外界物質(zhì)和感染的‘細(xì)胞因子’，免疫系統(tǒng)就會(huì)不斷輸送士兵過(guò)來(lái)。


Platelets inbound! Aha, see? GP1b. And I guess the metal things are coagulation factors (reminder that these are normally dissolved in plasma, and generally not directly carried by platelets).
血小板入場(chǎng)！看吧，GP1b。我估計(jì)金屬的東西是“凝血因子”。提醒下，這些因子一般溶于血漿，不由血小板輸送。

Aaaand boom, secondary hemostasis. Oh yeah, although fibrin is the chief protein required for forming a mature clot, any cells in the vicinity will get stuck and incorporated into the clot. The ultimate fate of all of these cells (platelets, entrapped RBCs and anything else) will be to ultimately die and degenerate as the clot matures, until it is either broken up by fibrinolytic enzymes, eaten up by macrophages, or (as scabs do) falls away. Late in the healing process, the normal tissues will regenerate.

當(dāng)當(dāng)當(dāng)。第二次止血過(guò)程。哦，沒(méi)錯(cuò)，盡管止血主要需要‘血纖蛋白’，但是它也會(huì)把周邊的細(xì)胞吸過(guò)來(lái)。這些細(xì)胞的最終命運(yùn)（血小板，被吸的紅血球等等），就是在血凝塊形成好時(shí)死去，降解。它們可能被“溶解纖維蛋白酶”分解，被“巨噬細(xì)胞”吃掉，或者隨著血痂脫落。之后的愈合期里，會(huì)再生出正常組織。

Summary

總結(jié)
Another fairly humdrum infectious incursion resulting from an abrasion. Again, this probably required no treatment and resolved naturally. I think we can get comfortable with our heroes sticking around for a long time, because they really should have died by now.


總結(jié)，這是擦傷引起的臨時(shí)性感染。它也不需要特別處理，會(huì)自己痊愈。主角們都自帶光環(huán)，因?yàn)樗鼈儸F(xiàn)在本該死掉。

生物類單詞

platelet? 血小板

precusor? 前身

megakaryocyte? 巨核細(xì)胞

nucleus? 細(xì)胞核

hemostasis? 止血

vessel? 血管

vascular endothelium? 血管內(nèi)皮

collagen 膠原

receptor 受體

substrate? 底物

glycoprotein? 糖蛋白

fibrinogen? 纖維蛋白原

platelet plug? 血小板栓

coagulation factor? 凝血因子

fibrin? 血纖蛋白

fibrinogen? 纖維蛋白原

inherited defect? 先天缺陷

acquired malfunction? 后天缺陷

cytomorphology? 細(xì)胞形態(tài)

epidermis? 表皮

amino acid? 氨基酸

plasma? 血漿

lipid? 磷脂

glucose 葡萄糖

nonpolar? 非極性

thrombus? 血栓

endothelial? 內(nèi)皮的

endothelium 內(nèi)皮

epithelial? 上皮的

Staphylococcus Aureus? 金黃色葡萄球菌

culture? 培養(yǎng)液

pneumonia? 肺炎

endocarditis? ?心內(nèi)膜炎

Streptococcus Pyogenes? 釀膿鏈球菌

strep throat? 鏈球菌性喉炎

Pseudomonas Aeruginosa? 綠膿桿菌

antibiotics? 抗生素

diapedesis? ?血細(xì)胞滲出

cytokine? ? 細(xì)胞因子