利用SCID小鼠模型评价-80℃冷冻人血小板的体内生存能力

为了评估人血小板-80℃冷冻保存后在活体内的生存能力,取新鲜机采血小板加入二甲基亚砜（DMSO）,使其终浓度为5％,于～80℃保存10天后,取出立即放置于37℃水浴箱中快速解冻,并离心浓缩10倍。用带有超细针头的胰岛素注射器抽取浓缩血小板1130μl,经尾静脉注入重症联合免疫缺陷（SCID）小鼠体内,在注入0．5、2、4、6、12、24小时时采集小鼠全血,肝素抗凝,用CD61-PE标记后,流式细胞术计数人血小板,以30分钟时的人血小板计数为100％,计算人血小板存活率。结果表明：冷冻血小板在活体内存活率明显降低,新鲜血小板和冷冻血小板输注SCID小鼠体内4小时时的存活率分别为（79．5±9．1）％和（40．6±6．6）％（P〈0．01）,推算半寿期（T1/2）分别为7小时和2．5小时。结论：血小板-80℃冷冻保存后在活体内的生存能力降低。     

类似人弥漫型大B细胞淋巴瘤小鼠模型的免疫学特征

本研究建立类似人弥漫型大B细胞淋巴瘤的BALB／c小鼠模型并探索其免疫学特征。将鼠源性B淋巴瘤细胞株（A20细胞）接种于同源BALB／c小鼠以建立B细胞淋巴瘤鼠模型。实验分为3组：成瘤小鼠组,未成瘤小鼠组和正常小鼠组（对照组）。用流式细胞术检测肿瘤细胞CD抗原表达及成瘤小鼠、未成瘤小鼠和对照正常小鼠的外周血和脾脏的T／B淋巴细胞亚群比例。结果表明：在成功构建病理学形态类似人弥漫大B细胞淋巴瘤的BALB／c鼠模型肿瘤组织中,检测到CD3、CD4、CD8、CD19、CD30阳性细胞的比例分别为（49．27±23．75）％,（6．07±3．65）％,（51．2±23．1）％,（67．06±16．39）％,（37．93±17．03）％,与接种前A20细胞相比,其CD3和CD8阳性细胞比例显著升高,CD19阳性表达比例显著下降（P〈0．05）。成瘤小鼠外周血淋巴细胞亚群阳性表达比例较正常小鼠有显著差异,其CD3和CD4阳性细胞比例显著降低（P〈0．05）。未成瘤小鼠脾脏淋巴细胞亚群的阳性表达比例与正常小鼠相比,CD3、CD4、CD8阳性细胞比例降低,而CD19阳性细胞比例升高（P〈0．05）。结论：本研究为在有免疫功能的小鼠体内进行B细胞淋巴瘤相关研究提供了免疫相关实验依据。     

未成熟树突状细胞-胃癌细胞融合细胞来源的exosome诱导特异性抗肿瘤免疫

目的观察未成熟树突状细胞（DC）-胃癌细胞融合细胞来源的exosome诱导特异性抗肿瘤免疫的效果。方法以细胞培养技术将BALB／c小鼠未成熟Dc与人胃癌细胞SGC-7901融合,并提取融合细胞分泌的exosome作为瘤苗。将人胃癌细胞株接种于BALB／c小鼠以建立4组荷瘤小鼠模型,A、B、C组小鼠接种SGC-7901细胞。D蛆小鼠接种BGC．823细胞。各组2周后开始在腹腔接种相应瘤苗。A组瘤苗为对照用PBS;B组溜苗为BALB／c小鼠来源的未成熟Dc,c组及D组瘤苗为未成熟DC-SGC7901融合细胞来源的exosome。每组取6只小鼠收集脾细胞悬液,进行体外细胞毒实验。剩余每组6只小鼠留待观察生存期。结果A、B、C、D组小鼠脾细胞悬液的细胞毒性分别为（27．22±7．31）％、（58．28±7．80）％、（72．36±6．28）％、（43．15±5。60）％,4组小鼠的存活时间分别为（14．2±1．3）d、（29．2±1．8）d、（37．6±2．2）d、（22．1±2．6）d。方差分析提示组间差异有统计学意义（P〈0．05）;S-N-K检验提示各组之间的差异均有统计学意义（P〈0．05）。结论未成熟DC-胃癌细胞融合细胞来源的exosome作为新型、高效肿瘤疫苗,可诱导抗胃癌细胞的特异性免疫反应。     

在人-小鼠异种移植模型中提高人红细胞产生效率条件的优化

本研究旨在探讨在建立人-小鼠异种移植模型中提高人红细胞产生效率的条件。本研究从三个方面分别进行条件优化：①受体免疫缺陷小鼠品系选择,分别对NOD／SCID和NOD／SCID／IL2rγnull两种小鼠品系进行移植,考察移植后不同品系小鼠嵌合率和人红细胞发育情况;②考察照射剂量和照射方法对小鼠生存率的影响;③优化人造血干细胞培养条件及感染方法,检测重建率及红细胞产生率。结果表明,移植后4周检测小鼠骨髓细胞显示,NOD／SCID／IL2rγnull小鼠人CD45比例可达（51．4±13．9）％,并能检测到人红细胞（5．98±3．46）％;利用x射线分2次对小鼠进行总剂量2．5Gy的照射,照射后小鼠生存率可以达到100％;利用新鲜脐带血分离的CD34＋细胞,不经过冻融和分选过程,在分离后72h内完成转染和移植过程,移植后嵌合率可达（51．4±13．9）％,并且人红细胞产生的效率为（5．98±3．46）％。结论：利用x射线分两次照射NOD／SCID／IL2rγnull小鼠后通过尾静脉注射2×10^5个细胞,新鲜分离的人脐带血CD34＋细胞在移植前缩短体外培养时间（≤72h）,有利于提高免疫缺陷小鼠体内人红细胞产生效率。     

应用小鼠模型评价人血小板体内活力的方法研究

目的选择合适的方法抑制小鼠对输入的人血小板的快速吞噬清除,建立适合于评价人血小板体内活力的小鼠实验动物模型。方法对4周龄雄性昆明鼠分别腹腔注射不同剂量地塞米松（DEX）,用碳粒廓清试验检测小鼠巨噬细胞抑制效果。分别给DEX鼠和对照鼠尾静脉输注新鲜的人血小板,用小鼠抗人CD41-FITC单克隆抗体和流式细胞仪检测小鼠全血中的人血小板数,比较人血小板在小鼠体内的回收率和生存时间的差异。给DEX鼠分别输注22℃保存5d或4℃保存1d的人血小板,观察血小板体内活力的差异。结果碳粒廓清试验显示,注射高、低两种剂量地塞米松（30mg、60mg/kg体重）的小鼠吞噬指数分别为2.90±0.69和3.84±0.53,两组差异无统计学意义（n=5,P〉0.05）;而与对照鼠6.69±1.30相比差异均有统计学意义（P〈0.05）。以低剂量DEX建立小鼠模型,输注新鲜人血小板,24h回收率和生存时间与对照鼠相比分别为（36.62±13.90）%,（25.92±9.66）hvs（0.96±0.61）%,（5.10±0.58）h,明显高于对照鼠（n=6,P〈0.05）。用DEX鼠检测22℃保存5d或4℃保存1d的人血小板与22℃保存1d的血小板相比,24h回收率和生存时间差异均有统计学意义（P〈0.05）。结论地塞米松有效地延长了人血小板在小鼠体内的生存时间。该小鼠模型可检测22℃或4℃保存的血小板体内活力的差异,有望用于评价人血小板的体内活力。     

桂皮醛对抗血小板聚集和血栓形成的特点

目的：观察桂皮醛对血小板聚集和血栓形成的影响。方法：实验于2005—07／11在第四军医大学药学系药物研究所实验室完成。④体外血小板聚集实验：制备大鼠洗涤血小板，观察0．15，0．30和0．60mmol／L桂皮醛对胶原蛋白（100mg／L）和凝血酶（3U／mL）诱导的大鼠体外血小板聚集的抑制作用。桂皮醛购自中国医药集团上海化学试剂公司，纯度〉98％。②出、凝血时间测定及胶原蛋白-肾上腺素诱发体内血栓形成实验：取BALB／c小鼠60只，随机分成6组（n=10），生理盐水组灌胃生理盐水；阿司匹林组灌胃阿司匹林100mg／kg为阳性对照；还设置桂皮醛灌胃（250，500mg／kg）和腹腔注射（50，100mg／kg）4个剂量组。所有动物每天给药1次，10μL/g，连续11d。第10天给药后1h采用断尾法和玻片法测定小鼠出血、凝血时间；第11天给药后1h观察小鼠尾静脉注射胶原蛋白（3．57mg／kg）-肾上腺素（0．143mg／kg）混合血栓诱导剂后5min内的存活率。⑧动-静脉旁路血栓形成实验：SD大鼠48只，随机分为6组（n=8）。生理盐水组灌胃生理盐水；阿司匹林组灌胃阿司匹林80mg／kg为阳性对照；桂皮醛分为灌胃200，400mg／kg组和腹腔注射40，80mg/kg4个剂量组。所有动物每天给药1次，10μL／g，连续10d。末次给药后1h测定动-静脉旁路丝线上的血栓湿质量。结果外鼠60只和大鼠48只全部进入结果分析。①桂皮醛能够明显抑制胶原蛋白和凝血酶诱导的大鼠体外血小板聚集，并呈剂量依赖性，与对照组比较差异显著（P〈0．05，0．01）。②桂皮醛显著延长小鼠出、凝血时间，与对照组比较差异非常显著（P〈0．01）。⑧胶原蛋白-肾上腺素诱发性小鼠肺动脉栓塞存活率：生理盐水组为10％，阿司匹林组为80％，桂皮醛各剂量组为70％～100％。④动-静脉旁路丝线上的血栓湿质量：阿司匹林组和桂皮醛各剂量组均低于生理盐水组（P〈0．01）；桂皮醛各剂量组对大鼠血栓的抑制率范围为30％～43．4％。结论：桂皮醛体外能够明显抑制胶原蛋白和凝血酶诱导的大鼠血浆中血小板的聚集；体内能够显著延长小鼠断尾后的出、凝血时间，减轻大鼠动-静脉旁路丝线上血栓的质量。提示桂皮醛具有明显抗血小板聚集和体内抗血栓作用。     

利用SCID小鼠模型监测人血小板常温保存期内体内生存力的变化

目的监测和比较人浓缩血小板和单采血小板常温保存后在动物体内生存力的变化。方法浓缩血小板和单采血小板各10(人)份,22℃振荡保存,在保存0—7 d内的不同时间分别取样1 ml,并将样品浓缩10倍后,经尾静脉分别注入80只重症联合免疫缺陷(SCID)小鼠体内,在注入30 min和4 h时经尾尖采集小鼠全血30μl/只,肝素抗凝,用CD61-PE标记后,流式细胞术计数其中的人血小板数,以30 min时的人血小板计数为100%,计算输注4 h时的人血小板存活率。结果保存0、3、5、7 d时,单采血小板和浓缩血小板在输入SCID小鼠体内4 h时的血小板存活率分别为(70.5±7.5)%、(69.8±8.0)%、(67.5±8.4)%、(55.6±4.7)%和(68.7±8.1)%、(71.2±8.9)%、(70.2±7.8)%、(58.1±5.4)%,在相同保存期内,2种血小板制品相比差异无统计学意义(P>0.05);保存7 d时,2种血小板的体内存活率均明显降低,与0 d相比差异具统计学意义(P<0.01)。结论 22℃振荡保存5 d内,血小板在SCID小鼠体内生存力无明显变化,保存7 d时存活率降低;浓缩血小板和单采血小板的输注效果相同。     

不同来源人造血干/祖细胞在NOD/SCID小鼠体内归巢能力的差异

目的 比较不同来源的人造血干／祖细胞在NOD／SCID小鼠体内归巢能力的差异性，并探讨其体内归巢能力与膜表面归巢相关分子CXCR4表达水平的相关性。方法 采用流式细胞术（FACS）检测新鲜脐血、冻存脐血、动员后外周血（mPB）及骨髓来源的CD34^＋细胞表面CXCR4表达水平；将荧光染料CFSE标记的人CD34^＋细胞移植人接受照射的NOD／SCID小鼠，移植后20小时检测已归巢于NOD／SCID小鼠骨髓及脾脏中不同来源的人CD34^＋细胞，计算其相应的骨髓及脾脏归巢效率；并将小鼠股骨制成组织切片，荧光显微镜下观察人CD34^＋细胞在小鼠骨髓腔内的分布。结果 新鲜脐血、冻存脐血、mPB和骨髓CD34^＋细胞膜表面CXCR4表达阳性率分别为（49.52±1．12）％。（46．12±2．29）％，（48．50±2．48）％和（65．39±1．27）％，CD34^＋细胞在NOD／SCID小鼠骨髓的归巢效率分别为（3．00±0．44）％，（2．84±0．46）％，（4．06±0．70）％及（5．76±0．52）％；在脾脏的归巢率分别为（1．88±0．12）％，（1．80±0．15）％，（1．90±0．22）％，（2．16±0．34）％。归巢的CD34^＋细胞主要分布于小鼠股骨的骨内膜区域。结论 脐血CD34^＋细胞膜表面CXCR4水平低于mPB和骨髓。经冻存复苏后脐血CD34^＋细胞膜表面CXCR4水平略有下调。脐血CD34^＋细胞在照射NOD／SCID小鼠的骨髓归巢效率低于mPB和骨髓。     

血标本室温放置时间对血小板聚集的影响

目的探讨血标本室温放置时间对血小板聚集的检验结果影响。方法随机采集126例门诊体检健康志愿者静脉血标本,枸橼酸钠抗凝,离心分离富含血小板血浆（PRP）和贫血小板血浆（PPP）,采用血浆比浊法,分别在不同的时间点测血小板聚集率。结果标本室温放置1.5～24h,10μmol／L二磷酸腺苷（ADP）诱导血小板聚集率为（75．0±11．O）%～（28．7±11．5）％（F=244．84,P〈0．01）,0．5mmol／L和1．0mmol／L花生四烯酸（AA）诱导血小板聚集率分另q为（83．2±8．7）％～（6．7±1O．4）％（F=71．09,P〈0．01）,（84．6±8．5）％～（11．2±16．7）％（F=101．90,P〈0．01）,都随时间延长而降低;pH值为（7．78±0．07）～（8．43±0．09）,随时间延长而增大。结论标本室温放置时间对ADP和AA诱导血小板聚集有明显的影响。10μmol／LADP和0．5mmol／LAA诱导血小板聚集,标本检测需在4h内完成,血小板聚集率随时间延长而降低可能与标本老化、pH过高有关。     

抗小鼠CD122抗体促进脐血CD34^＋细胞在NOD/SCID小鼠体内的重建

本研究旨在探讨抗小鼠CD122抗体促进人脐血CD34^＋造血干细胞在非肥胖糖尿病/重症联合免疫缺陷（NOD/SCID）小鼠体内的重建能力。对NOD/SCID小鼠进行半致死剂量γ射线照射,照射后腹腔注射200μg同型对照抗体或者抗小鼠CD122抗体,6-8 h后经尾静脉注射人脐血CD34^＋细胞或者注入PBS作为对照。处理后第2、3、4周取仅注射抗小鼠CD122抗体或同型对照抗体的小鼠外周血,动态监测小鼠NK细胞比例变化。在经过脐血CD34^＋细胞移植的小鼠中,利用流式细胞术对移植后小鼠骨髓中人CD45^＋比例以及CD45^＋细胞亚群中人CD34,CD19和CD33比例进行分析,观察抗小鼠CD122抗体对人造血干细胞在小鼠体内重建能力的影响。结果表明,用抗CD122抗体处理后2周和3周时,小鼠外周血中NK细胞比例分别为（4.6±0.6）%和（5.7±1.7）%,与注射同型对照抗体的NOD/SCID小鼠（12.2±1.4）%和（13.3±1.2）%相比下降约60%。在移植了人脐血CD34^＋细胞的小鼠中,同时用CD122抗体处理组在移植后6周和8周时小鼠骨髓中h CD45^＋比例分别为（63.0±12.2）%和（53.2±16.3）%,明显高于同型对照抗体组中h CD45^＋比例（7.7±3.6）%和（6.1±2.4）%。此外,经过抗CD122抗体处理组的小鼠移植8周后骨髓中仍能够明显的检测到人CD34^＋细胞的存在。结论：抗小鼠CD122抗体通过降低NOD/SCID小鼠的NK细胞的比例,大大促进了人脐血CD34^＋造血干细胞在免疫缺陷小鼠体内的重建能力。     

COMPARATIVE BACTERICIDAL ACTIVITIES OF BLOOD SERUM AND PLASMA SERUM

Rabbit and human plasma can be prepared without resort to anticoagulants by employing low temperatures and non-wetting surfaces. Serum formed after clotting of rabbit plasma devoid of cells and platelets manifests essentially no bactericidal activity on Bacillus subtilis, Bacillus megaterium, and a strain of Staphylococcus aureus. In contrast, rabbit blood serum exhibits this activity to a high degree. Rabbit plasma rich in platelets gives rise to a serum with capacity to kill these Gram-positive microbes equal to that of serum prepared from whole blood. This heat-stable antibacterial agent is efficiently formed or released when platelets are present during the coagulation of plasma, but not on incubation of platelets in heparinized or citrated plasma or in saline. Leucocytes and red cells appear to play no significant role in its production. Rabbit blood serum and plasma serum have similar heat-labile lethal effects on enteric bacilli. Human serum, whether from blood or plasma, manifests much less bactericidal activity on Bacillus subtilis than does rabbit blood serum. These findings serve to emphasize the fact that substances formed or released during coagulation of whole blood may impart to the serum activities not present in circulating plasma.     

人脐血细胞输注对心肌梗死大鼠的治疗作用

目的探讨脐血细胞输注对急性心肌梗死(AMI)大鼠的治疗作用,为脐血应用于心血管疾病的临床治疗提供实验依据。方法将30只Wistar大鼠随机分为正常组、模型组和治疗组(10只/组),模型组和治疗组腹腔注射异丙肾上腺素4mg/kg.d,连续2 d,复制大鼠AMI模型。将脐血细胞体外用DAPI标记后,经尾静脉输入治疗组大鼠体内,模型组给予等量无血清培养基,3周后超声心动图检测大鼠心功能情况,心脏标本连续冰冻切片观察标记的脐血细胞,石蜡切片HE染色观察心脏病理改变。结果AMI大鼠输注脐血细胞3周后,治疗组心肌组织冰冻切片可观察到DAPI荧光标记阳性细胞存在;与模型组比较,治疗组心功能明显改善(P<0.05),HE染色可见心肌充血及炎症减轻,心肌细胞萎缩和心肌瘢痕组织明显减少。结论在未使用免疫抑制剂的情况下,脐血细胞经尾静脉输注治疗后可归巢至AMI大鼠心脏,并能改善心功能,脐血治疗有望成为治疗AMI的有效手段。     

Polyamine distribution in cellular compartments of blood and in aging erythrocytes.

Human blood was separated into pure preparations of erythrocytes, mononuclear leukocytes, polymorphonuclear leukocytes, platelets, and platelet free plasma. The mean concentrations of putrescine, spermidine, and spermine per 10(9) cells were found to be several orders of magnitude higher for leukocytes than erythrocytes. There was no significant difference between leukocyte types. Platelets and plasma had relatively low levels in proportion to the amounts contributed by erythrocytes and leukocytes to whole blood. Human erythrocytes were age-separated by density and the changes in polyamine concentrations in maturing erythrocytes were documented. There were highly significant statistical differences between young and old red blood cells for putrescine, spermidine and spermine. The clinical use of red blood cell polyamines as an indicator of the activity of the bone marrow in anemic states is suggested.     

Kinetics and mobilization from the spleen of indium-111-labeled platelets during platelet apheresis

The rate and extent of platelet mobilization from the spleen were measured, and their relationship to the removal of platelets from the peripheral blood during discontinuous flow platelet apheresis was determined in four normal volunteers. Autologous platelets were labeled with Indium-111-oxine and in vivo whole body and organ In-111 radioactivity quantitated with a scintillation camera and a computer-assisted imaging system. Dynamic changes in splenic radioactivity were monitored during 12 cycles of platelet apheresis. The number of platelets harvested and changes in whole body and blood In-111 activity were determined during the procedure. The platelet life-span was estimated, and the sites of sequestration of labeled platelets was measured. Platelet apheresis removed a mean of 64 percent of platelets in the circulation; i.e., 48 percent of all platelets in the body. During the procedures, 28.0 +/- 9.4 percent In-111-labeled platelets in the body were removed, splenic radioactivity decreased by 36.5 +/- 13.2 percent, and whole body activity decreased by 34.5 +/- 9.7 percent. In-111 activity in the spleen and whole body decreased in parallel, indicating a dynamic equilibrium between these pools. The life-span of the labeled platelets was 226 +/- 25 hours, similar to that of normal subjects. The major sites of sequestration of senescent platelets were the spleen (37.9 +/- 20%) and liver (30.3 +/- 5.6%); this is similar to that found in normal subjects. We conclude that as platelets are removed from the peripheral blood, the blood pool is rapidly and effectively replenished from the splenic platelet pool. These two pools are in dynamic equilibrium and permit removal of large numbers of platelets without resultant thrombocytopenia. Platelet apheresis does not adversely effect platelet life-span, and the sequestration pattern in the reticuloendothelial system is normal.     

Technique for increased granulocyte recovery from human whole blood by counterflow centrifugation elutriation I. In vitro analyses

Human granulocytes were isolated from 120 ml of whole blood by a modified counterflow centrifugation-elutriation (CCE) technique. Overall recovery of isolated granulocytes averaged 2.82 +/− 0.25 × 10(8) cells or 77 per cent yield from whole blood with 96 per cent granulocyte purity and 4 per cent mononuclear leukocytes. The granulocyte fraction was assayed in vitro to determine chemotactic response, stimulated oxygen consumption in the presence of latex beads, bactericidal capacity, and enzyme activities. Cellular integrity was determined by scanning and transmission electron microscopy as well as by cell volume analysis. The data suggest that granulocytes isolated by CCE suffered no discernible loss of function or morphologic damage. The granulocytes are free of platelets and most mononuclear leukocytes and erythrocytes, and have not been exposed to sedimenting agents or surface adhesive agents such as dextran, nylon or glass wool.     

Implementation of a strategy to prevent TRALI in a regional blood centre

Transfusion-related acute lung injury (TRALI) can be a life-threatening complication of transfusion and it is probably underdiagnosed. Human leucocyte antigen (HLA) and granulocyte antibodies are thought to play a major role, but preventive measures are difficult to implement. In our regional blood centre, we implemented a preventive strategy avoiding donor deferral. Previously, pregnant apheresis donors were screened for HLA antibodies, and those with positive results were assigned to a plasma-only protocol. Plasma from these donors and from all previously pregnant whole blood donors was diverted for protein fractionation. Plasma-poor red blood cells (in additive solution, buffy coat removed) and platelets (pools with additive solution) were prepared. Prestorage leucodepletion was also applied. We found HLA antibodies in 18.1% of previously pregnant apheresis donors, and our strategy caused a 6.0% loss of apheresis platelets, a 4.8% increase of apheresis fresh frozen plasma (FFP) and a 7.8% loss of transfusable apheresis FFP. The effect on FFP from whole blood donors could be compensated. The platelet preparation method reduced the mean volume of plasma from each donor to 24.4 mL. Fifteen months after the start of our strategy, no cases of TRALI have been reported. Our experience shows that a practical strategy to prevent TRALI is feasible.     

Bernard-Soulier syndrome: whole blood diagnostic assays of platelets

Diagnosing Bernard-Soulier syndrome (BSS), a congenital hemorrhagic disorder of blood platelets, is complicated by the difficulty of separating the giant platelets from other blood cells to allow studies of platelet function and structure. We report on the use of three whole blood assays for diagnosing BSS. Whole blood platelet aggregation responses studied with an electrical impedance aggregometer were equivalent to those more laboriously obtained by using platelet-rich plasma prepared by unit gravity sedimentation and studied with an optical light transmittance aggregometer. Platelet aggregation responses were normal with adenosine diphosphate or collagen stimulation but absent with ristocetin or bovine plasma stimulation. Whole blood radioimmunoassay of platelet glycoprotein (GP) expression was performed by using iodinated murine monoclonal antibodies HP1-1D (anti-GP IIb/IIIa) and 6D1 (anti-GP Ib). After incubation with citrated whole blood, centrifugation was used to separate cell-bound antibody that was quantitated with a gamma counter. The patient's whole blood had a normal level of cell-bound GP IIb/IIIa but a substantially reduced level of cell-bound GP Ib (5% of normal mean). Whole blood smear immunocytochemical staining with monoclonal antibodies and qualitative analysis by light microscopy revealed a considerable reduction of GP Ib expression by the patient's giant platelets, whereas GP IIb/IIIa expression was normal. These data helped establish the diagnosis of BSS. We conclude that these three relatively simple assays of platelets in whole blood should be of particular value in the clinical laboratory differential diagnosis of patients with congenital thrombocytopenias and giant platelet syndromes.     

Survival of fresh human platelets in a rabbit model as traced by flow cytometry

BACKGROUND: In the event of hemorrhage and blood loss, platelets play a vital role in the coagulation process. However, there are currently no acceptable protocols for long-term storage of platelets. As a first step toward testing the efficacy of stored platelets or platelet substitutes in vivo, a flow cytometric technique was developed to detect human platelets in rabbit blood. STUDY DESIGN AND METHODS: Human platelets were transfused to rabbits whose reticuloendothelial system was inhibited by the administration of ethyl palmitate. Because human and rabbit platelets display surface molecules with different epitopes, human platelets were selectively labeled with antibodies specific for glycoprotein IX (CD42a). As this antibody does not label rabbit platelets, it allows discrimination of human from rabbit platelets in samples of rabbit blood containing both types of platelets. RESULTS: Survival of human platelets in rabbits was monitored by flow cytometry and fluorescence microscopy in blood drawn at various times after the platelet transfusion. Fresh human platelets transfused to untreated control rabbits (n = 3) were removed from circulation within 10 minutes of the completion of the transfusion. Fresh platelets (1 day old) transfused to rabbits treated with ethyl palmitate (n = 5) survived for 24 hours with an average half-life of 8.6 hours. In contrast, 8-day-old platelets were cleared from the circulation sooner with an average half- life of 2.9 hours (n = 4). CONCLUSION: This report describes a rapid and efficient method of assessing the survival of human platelets in a rabbit model using flow cytometry. This technique will enable the monitoring in rabbits of human platelets prepared by various preservation protocols.