疟原虫血液浓集法的改进

疟原虫血液浓集法的改进韦林（广东省恩平市圣堂中心卫生院，广东恩平５２９４４１）《临床检验杂志》１９９４年第３期“介绍一种疟原虫的血液浓集法”（以下简称原法）一文觉得还不够完善。原法用抗凝血离心后只取红细胞表层做镜检是不够的，这仅适用于红细胞体积显著增...     

间日疟原虫的血液浓缩检查法

血液涂片检查疟原虫是临床诊断疟疾的依据，通常采用厚血膜法和薄血膜法。笔者从红斑狼疮细胞的检验方法中得到启发，采用血液离心分层方法使感染有疟原虫的红细胞浓集，既保持了疟原虫在红细胞中的形态完整，又提高了疟原虫的检出率。现报告如下。     

疟原虫检查的微量浓集法

传统疟原虫检查法 ,薄血膜虫体形态完整 ,易辩认 ,但虫量太少 ,易漏检 ,且检查费时 ,厚血膜则溶血时间太长 ,虫体形态有所改变 ,很难辩认。而传统浓集法虽显著提高了检出率 ,有利于虫种鉴别 ,但需抽取静脉血 ,操作较繁琐 ,不适于大规模普查 ,且其镜检范围只限于离心后的表层红细胞 ,易漏诊。微量浓集法则克服上述缺点 ,该法根据受间日疟侵袭的红细胞比正常红细胞轻 ,而受恶性疟、三日疟、卵形疟侵袭的红细胞则比正常红细胞略重的原理 ,用毛细管采血 ,通过高速离心分层 ,分别取离心后的最底层血和与白细胞交界的表层红细胞 ,涂片染色镜检。现…     

浓集法检查人血中疟原虫

本文作者采用Percoll连续密度梯度离心法浓集血中疟原虫.其方法为取一份1.5M NaCl加9份Percoll即成100%Percoll混合液,密度近似1.1300g/ml.取8.5份100% Percoll液加1.5份生理盐水混合即成85%(V/V)实验溶液.用一支无菌滴管从含EDTA或肝素抗凝管内吸取1.0ml含疟原虫全血放入含有85%Percoll 9ml 聚乙烯试管内(内径16mm)使成一血液层,30000g10C离心40分钟.离心后血液被分成6层,从上而下分别为S_1(血     

疟原虫厚血膜改良染色法的诊断效果

目的探讨疟原虫厚血膜染色法改良策略,为提高疟原虫诊出率提供新方法。方法取患者外周血置于乙二胺四乙酸抗凝管中,利用离心机离心,离心参数为3 000r/min离心10min后制成血涂片,作为传统方法制作的血涂片。与传统方法不同,改良染色法将血涂片浸入蒸馏水1s左右,滴一滴95%的乙醇固定,后续行常规染色,约20min后将涂片冲洗晾干,观察利用乙醇固定对疟原虫血膜染色效果的影响。结果经对比发现利用蒸馏水浸泡后制成的疟原虫血膜涂片背景干净,干扰色较少;疟原虫虫体清晰,疟原虫诊出率较高。结论疟原虫厚血膜改良染色法中虫体显示清晰,利于疾病诊断,值得临床推广。     

介绍一种简易压积管清洗法

我科使用北京普利生ＬＢＹ－Ｎ６Ａ型血流变分析仪作血流变学检查时，采用压积管离心法作压积测定，然后将数据输入微机进行计算处理，但由于用量大，清洗压积管内的血液时很麻烦，费工又费时，因此，在长期实际工作中我们摸索出一种简易的压积管血液清洗法，现介绍如下： 取一次性 １． １ｃｍ × １０ｃｍ塑料管一支，在管底部放入 １．０ｃｍ高度的硬纸团（打印纸的边角料），然后将测试后的压积管倒插入该管内，进行离心沉淀，４０００ｒ／ｍｉｎ离心５分钟，此时压积管中的血细胞和血浆部全部沉淀于纸团内，奔去一次性塑料管，然后将压…     

浓集法检查人血中疟原虫

本文作者采用Percoll连续密度梯度高心法浓集血中疟原虫。其方法为取一份1．smol／LNaCI加9份Percoll即成100％Percll混合液，密度近似1．13009／ml，取8．5份100％Percoll液加1．5份生理盐水混合即成85％（V／V）实验溶液。用一支无菌滴管从含EryTA或肝素抗凝管内吸取1．0ml含疟原虫全血放人含有85％Percollgml聚乙烯试管内（内经16mm）使成一血液层，3000910oC离心40分钟，离心后血液被分成6层，从上而下分别为SI（血浆和血小板）、S：（白细胞）、S3（网织红细胞）、S‘（间日疟感染红细胞）、S3（恶性疟感染成熟红细胞）、s‘…     

红细胞的压积及介质差异对其沉降率的影响

目的探讨红细胞的压积及介质差异对其沉降率的影响.方法计算红细胞压积与血沉的相关系数;检验压积相差0.06,同性别的血沉的差异;检验男女等压积的血沉差异;观察红细胞在不同介质中的沉降率变化.结果红细胞压积与血沉呈明显负相关,相关系数绝对值为0.928～0.999(P<0.05 or P<0.01);压积相差0.06时,男、女血沉均有非常显著性差异(t值3.096～9.904,P<0.01);男女等压积组沉降率无显著性差异(t=1.338,P>0.05);不同介质对红细胞沉降率有明显影响.结论判断红细胞沉降率是否异常,红细胞压积要有可比性;红细胞在生理盐水中的沉降率很低.     

血性浆膜腔积液细胞学检查的技术处理改进

血性浆膜腔积液(下称血性积液)在排除脏器破裂后,它标志着肿瘤存在的可能。一般认为血性积液大部份由恶性肿瘤所致,因此其细胞学检查有较大的诊断价值。由于血性积液中大量的红细胞存在,影响了肿瘤细胞等有核细胞的浓集、涂片和镜下观察,这是血性积液细胞学检查阳性率不高的主要原因。我们对血性积液细胞学检查的技术处理作了几种改进,有利于提高阳性率,特介绍如下一、富集法:将抗凝的血性积液分装数支试管,2000rpm离心5分钟,吸取各管灰白色有核细胞层,合并移入红细胞压积管中,再以2000rpm离心5分钟,吸取灰白色层部分制成涂片数张,常规固定染色。二、分离法:将抗凝的血性积液置合适的试管或     

介绍一种疟原虫的血液浓集法

介绍一种疟原虫的血液浓集法朱卫中（龙泉市人民医院，浙江龙泉３２３７００）血膜涂片查找疟原虫是疟疾确诊的方法和依据，通常采用薄血膜法和厚血膜法。薄血膜法的血膜经染色后原虫形态结构完整、清晰，可根据各发育阶段的形态特征辨别原虫类型，适用于临床疟疾类型的诊...     

The effect of capillary tube diameter on microhematocrit value

Changes in percentages of donor deferrals associated with changes in the capillary tube size used for microhematocrit determinations led us to study the variables which influence microhematocrit values. Duplicate microhematocrit determinations were performed on a normal donor population with capillary tubes of different diameter, as well as with different anticoagulants, sample sites, centrifugation times, and degrees of operator skill. Microhematocrit values varied directly with capillary tube diameter over the range of diameters tested, and varied independently of sample site, centrifugation time, anticoagulant, and operator. The magnitude of the difference in microhematocrit values between small and large capillary tubes was approximately one volume percent in the microhematocrit range. Although differences of this magnitude are without clinical significance, they can be of substantial importance in attempts to minimize donor deferrals in a blood center. In our center, increasing the diameter of the capillary tube used for the microhematocrit determination allowed the collection of 6500 additional units of blood annually, or an approximate 3.5 percent increase in total collections.     

Predonation hematocrit measurement by whole blood electrical conductivity assay

The whole blood electrical conductivity method for predonation hematocrit determinations was studied. Forty capillary and venous blood samples were tested concurrently with electrical conductivity and centrifugation methods. The electrical conductivity method demonstrated acceptable accuracy but was less precise than the spun microhematocrit technique. Results from capillary samples were uniformly less precise and significantly lower than determinations from venous specimens. This study and previous reports suggest that capillary hematocrit values by any method may not accurately reflect the blood donor's venous hematocrit level. Blood centers should independently validate their anemia screening methods to avoid unnecessary deferrals and protect the anemic donor.     

Rapid kinetic measurement of lactate in plasma with a centrifugal analyzer.

In this method, blood is collected in ammonium heparinized microhematocrit tubes and lactate is directly determined in the plasma, separated within 15 min from the erythrocytes. Lactate is assayed by mixing 10 mul of sample with NAD+ and lactate dehydrogenase in tris(hydroxymethyl)aminomethane hydrazine buffer. The rate of increase in absorbance of the NADH formed, measured at 340 nm, is proportional to lactate concentration. The assay is complete in 4 min and absorbance is linearly related to concentration from 0.625 to 15 mmol/liter. Analytical recoveries of lactate added to plasma averaged 104% (range, 91-116%). Results compared well for plasma samples analyzed by this method with the CentrifiChem and the Du Pont aca.     

Use of blood specimens collected on filter paper in screening for abnormal hemoglobins.

Both cellulose acetate electrophoresis and citrate agar electrophoresis were performed on 834 blood samples collected on filter paper in Jamaica and shipped for testing to the National Hemoglobinopathy Standardization Laboratory at the U.S. National Center for Disease Control. Additionally, 30 blood samples collected locally were stored on filter paper, in microhematocrit capillary tubes, and as whole blood specimens; at selected times the samples were tested for stability to determine the best sample-collection technique for hemoglobin electrophoresis. Results were most nearly accurate when both cellulose acetate electrophoresis and citrate agar testing were used. The methods are easy to perform, but results are unreliable if the blood samples on filter paper are stored at 4 degrees C for longer than two weeks before they are tested.     

Second fingerstick: a simple method to increase the blood supply

Before blood donors are deferred because of a low hemoglobin determination by the copper sulfate procedure, they are routinely retested with a microhematocrit. The copper sulfate test and the microhematocrit usually are performed on blood samples taken from the same finger (or earlobe) puncture. We studied 201 male and female volunteer blood donors who failed the copper sulfate test to determine if more donors would be accepted for donation if blood from a second fingerpuncture, instead of the original fingerstick, was used for the microhematocrit determination. Venous blood samples were obtained to evaluate complete blood count and measures of iron status. The results indicated that the deferral rate was reduced by 46% using a fresh fingerpuncture for the microhematocrit determination. The iron status of the additional donors accepted on the basis of the second puncture was not significantly different from that of the donors accepted by the original fingerstick. We conclude that using a second fresh fingerpuncture for the microhematocrit determination after failing the copper sulfate test decreases the number of hematocrit deferrals and does not compromise the iron status of the additional donors.     

A new plastic evacuated tube with plasma separator

A new plastic-walled, evacuated blood collection tube (Terumo Venoject II) with plasma separator was evaluated for characteristics related to the use of plastic in place of glass. Plastic tubes were highly resistant to breakage through handling mishaps or failure during centrifugation. Higher centrifugation speed (13,600g) was well tolerated, and centrifugation times as short as 3 minutes at 13,600g effectively cleared plasma of cellular components, at high plasma yield. Plastic tubes were nearly completely combustible under incineration conditions commonly used for medical waste, and plastic tubes effectively retained vacuum during the typical shelf life of evacuated blood collection tubes. Collection of carbamezepine specimens in plastic tubes decreased levels an average of 6.8% compared to a heparinized glass tube control under conditions approximating routine use; levels of other drugs (phenytoin, phenobarbital, valproic acid, theophylline, and cyclosporine) were less significantly affected. This modest decrease appeared to result from a combination of an immediate interaction with the plastic surface of the tubes and a time-dependent interaction with the olefin-based separator. Modest but clear benefits including reduction in specimen breakage, reduced centrifugation time and reduced solid waste after incineration derive from the use of plastic in place of glass in evacuated blood collection tubes.©1995 wiley-Liss, inc.     

一例HIV窗口期样本三种试管核酸检测结果分析

目的通过对HIV窗口期样本三种类型真空采血管核酸检测结果的分析,探讨三种类型真空采血管样本对HIV窗口期样本核酸检测结果的影响。方法分析一例2018年7月30日在马边县采集的无偿献血者三种类型真空采血管HIV窗口期样本的核酸检测结果。第一种是带分离胶抗凝真空采血管5℃低温离心20 min;第二种是带分离胶促凝真空采血管25℃常温离心10 min;第三种是抗凝真空采血管(无分离胶)25℃常温离心5 min。对3份样本进行核酸检测。后续完成该样本的病毒载量检测,由市CDC完成献血者追踪和重新采样进行HIV确认。结果核酸检测结果是:第一种模式Ct值为32.4,第二种模式Ct值为32.69,第三种模式Ct值为32.76;病毒载量分析结果为3.28×103IU/mL;三个月后CDC重新采样确认为HIV阳性。结论试管类型对HIV窗口期样本核酸检测结果影响较小,足量无溶血无脂血的三种类型试管的样本都可以用于核酸检测。     

The effects of over-anticoagulated blood on hematocrit values by the microcentrifuge method

OBJECTIVE: To determine equivalency of hematocrit results by three methods. DESIGN: A total of 101 whole blood samples in EDTA tubes were analyzed in this repeated measures study. SETTING: East Carolina University's clinical laboratory science program, Greenville NC. PARTICIPANTS: The blood specimens were from adult patients at Nash General Hospital in Rocky Mount NC who had a CBC performed. MAIN OUTCOME MEASURE: Hematocrit values from a whole blood sample with EDTA anticoagulant performed by a Sysmex XE-2100 and by microcentrifuge with two different types of capillary tubes (i.e., heparinized and non-heparinized) filled from the EDTA tubes. RESULTS: The hematocrit means of the total sample for the three methods were 36.2%, 35.4%, and 35.6% for the Sysmex XE-2100, non-heparinized capillary tubes, and heparinized capillary tubes, respectively. Pearson correlation coefficient (pairwise) analyses produced significant r-values at an alpha of .01 for all three method comparisons. CONCLUSIONS: Based on statistically significant Pearson (pairwise) correlation coefficients, the hematocrit values by all three methods can be considered relatively equivalent. The differences between methods are quite small and would be clinically insignificant, thus likely not altering clinical decisions. Though this study was conducted under somewhat ideal conditions relative to the blood specimens selected, the results indicate that the additional dilution produced in a heparinized capillary tube when being filled from an EDTA-anticoagulated tube is not sufficient to produce clinically different microhematocrit results as compared to using the recommended non-heparinized capillary tube.     

Suitability of collection tubes with separator gels for collecting and storing blood samples for therapeutic drug monitoring (TDM).

In this study, we present significant changes occurring in serum drug concentrations while using blood collection tubes that contain a barrier gel. This report also contains results with antidepressant drugs, which have not been studied before with human samples. The drug concentrations were measured either with high performance liquid chromatography (HPLC) or fluorescence polarization immunoassay (FPIA). The results show that gel tubes are suitable for blood collection for antiepileptic, antibiotic, asthma and cardioactive drug measurements, since only slight adsorption was seen (0-5%). However, the studied tubes are not suitable for blood collection of antidepressants nor benzodiazepines, because the adsorption can be 5-30%. The adsorption was even higher (up to 40%) when samples were stored for 24 h after centrifugation in gel tubes. When the centrifugation step was performed after storage the effect of the barrier gel was lower (only 0-13%). Antidepressant drug measurements performed from patient specimens collected in the studied gel tubes and stored for 3 h showed <10% adsorption of the studied drugs. After 24 h storage time, concentrations of all analysed drugs decreased even more: adsorbed amount of drugs were about 5-20%. The studied gel tubes are proposed to be satisfactory for blood collection for antidepressant drug measurements if separation step is performed within 3 h after blood clotting. With the spiked samples the adsorption to barrier gel was higher, so it seems that adsorption is faster when drugs are not highly bound to serum proteins.     

Effect of collection tube type and preanalytical handling on myeloperoxidase concentrations

BACKGROUND: Myeloperoxidase (MPO) has shown potential as a marker for cardiovascular disease. Limited studies have been published with a variety of sample types, resulting in a wide range of MPO values. Little is known or understood about the impact of collection tube type and preanalytical handling of specimens for MPO determination. METHOD: MPO concentration was determined by use of the ARCHITECT(R) MPO research use assay, which is currently under development. Samples were collected into multiple anticoagulant collection tubes from donors and patients presenting to the emergency department with symptoms of acute coronary syndromes. Whole blood was stored on ice or at room temperature for predetermined time periods. We also evaluated serum and plasma after centrifugation followed by storage at room temperature, 2-8 degrees C, and below -10 degrees C. RESULTS: Baseline sample concentrations were dependent on collection tube type as well as handling conditions. MPO concentrations were consistently higher in samples collected in serum and heparin plasma tubes than in samples in EDTA or citrate tubes. Spike recovery was acceptable in all sera and plasma tested, indicating that the increased MPO concentrations were not due directly to an anticoagulant interference. CONCLUSIONS: The collection tube type and preanalytical handling are critical for accurate and consistent MPO measurement. The preferred anticoagulant and tubes are the EDTA or EDTA plasma preparation tube. MPO concentrations in samples collected in these tubes are stable before centrifugation as whole blood as well as plasma after processing.