Dielectric properties or kuamn red blood cell (RBC) suspension (ltematocrit 50%) from 243 healthy persons (120 males, 123 remales) were measured at 25Cin the frequency range rrom 1 to 500MHz, and analysed statisticall...Dielectric properties or kuamn red blood cell (RBC) suspension (ltematocrit 50%) from 243 healthy persons (120 males, 123 remales) were measured at 25Cin the frequency range rrom 1 to 500MHz, and analysed statistically. The measuringsystem controlled by an IBM-PC computer was composed or a network analyzer(HP4195A), coaxial line sensor and a temperature controlling set. The results showedthat the dielectric properties did not depend on either sex or blood group. However, agehad definite erfect. There was a critical age around 49 years when the dielectric data ofhuman RBC suspensions varied signiricantly.展开更多
Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in res...Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in resource-limited settings due to practical challenges, including lengthy and tedious procedures, and the need for specific equipment to centrifuge samples in glass capillary tubes. We report here on a study that was conducted in a rural region of eastern Uganda to evaluate new methods that take advantage of a field-deployable LED fluorescence microscope. Examination of acridine orange-stained blood smears by LED fluorescence microscopy resulted in a diagnostic accuracy that was similar to that of routine methods, while the time needed to identify parasites was shortened significantly. These findings make these new microscopy methods attractive alternatives to procedures that are currently used for diagnosis of T. b. rhodesiense human African trypanosomiasis.展开更多
Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is ve...Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is very low, and many cases are missed and left untreated. A clinical study was conducted in the Democratic Republic of the Congo to evaluate the accuracy of improved microscopy methods in diagnosis of HAT. These included examination by fluorescence microscopy (FM) of acridine orange (AO) stained smears of whole blood and smears made following a new procedure for concentrating trypanosomes by selective lysis of red blood cells (RBC). Methodology/Principal Findings: Venous blood was collected from 213 HAT cases, 101 HAT suspects and 95 controls and used to determine the accuracy of four microscopy methods: bright field microscopy of Giemsa-stained thick blood smears, FM of AO-stained thick blood smears, FM of AO-stained thick blood smears prepared after RBC lysis and concentration, and FM of AO-stained thin blood smears prepared after RBC lysis and concentration. The sensitivity of FM using thick blood smears stained with AO was 3 times higher than bright field microscopy using Giemsa-stained thick blood smears [19.7% (95% CI: 14.9% - 25.6%) versus 6.1% (95% CI: 3.6% - 10.2%)]. When the RBC lysis and concentration procedure was included, sensitivity of the test was further enhanced to 23.0% (95% CI: 17.9% - 29.1%) with thick blood smears and 34.3% (95% CI: 28.2% - 40.9%) with thin blood smears. Specificity of all four microscopy methods was 100% (95% CI: 96.1% - 100.0%). However, the miniature anion exchange chromatography technique (mAECT) and capillary tube centrifugation (CTC) method remained more sensitive. Conclusions: These new methods have practical advantages, including shorter staining time, ease of demonstration of parasites, and the possibility of archiving slides. They could, therefore, be alternative methods to improve case detection where concentration procedures such as mAECT or CTC are not performed.展开更多
Cryopreservation of red blood cells(RBCs)provides great potential benefits for providing transfusion timely in emergencies.High concentrations of glycerol(20%or 40%)are used for RBC cryopreservation in current clinica...Cryopreservation of red blood cells(RBCs)provides great potential benefits for providing transfusion timely in emergencies.High concentrations of glycerol(20%or 40%)are used for RBC cryopreservation in current clinical practice,which results in cytotoxicity and osmotic injuries that must be carefully controlled.However,existing studies on the low-glycerol cryopreservation of RBCs still suffer from the bottleneck of low hematocrit levels,which require relatively large storage space and an extra concentration process before transfusion,making it inconvenient(time-consuming,and also may cause injury and sample lose)for clinical applications.To this end,we develop a novel method for the glycerol-free cryopreservation of human RBCs with a high final hematocrit by using trehalose as the sole cryoprotectant to dehydrate RBCs and using core–shell alginate hydrogel microfibers to enhance heat transfer during cryopreservation.Different from previous studies,we achieve the cryopreservation of human RBCs at high hematocrit(>40%)with high recovery(up to 95%).Additionally,the washed RBCs post-cryopreserved are proved to maintain their morphology,mechanics,and functional properties.This may provide a nontoxic,high-efficiency,and glycerol-free approach for RBC cryopreservation,along with potential clinical transfusion benefits.展开更多
目的比较添加不同比例的MAP保存液对西藏拉萨地区悬浮红细胞的保存质量的影响。方法将西藏自治区血液中心采集的400 m L全血(共6袋),每袋平均分成2份,每份再分别离心分离去除血浆,按全血与保存液的不同比例包括4∶1和4∶1.5,每份红细胞...目的比较添加不同比例的MAP保存液对西藏拉萨地区悬浮红细胞的保存质量的影响。方法将西藏自治区血液中心采集的400 m L全血(共6袋),每袋平均分成2份,每份再分别离心分离去除血浆,按全血与保存液的不同比例包括4∶1和4∶1.5,每份红细胞分别加入50 m L(对照组)和75m L MAP保存液(实验组)制备得到悬浮红细胞,每份分别分装到4个50 m L小袋,于1、7、14、35 d分别检测血常规、p H值、全血粘度、电解质、葡萄糖、乳酸、游离Hb、红细胞渗透脆性、红细胞变形性等指标。结果在保存d1,实验组的红细胞数、Hb浓度、Hct、血液粘度都明显低于对照组,分别为(5.66±0.49)vs(6.72±0.68)×1012/L,(178.2±13.03)vs(212.6±14.2)g/L,(63.7±5.9)%vs(53.7±4.7)%,(6.99±1.82)vs(11.60±2.86)10s-1,至保存末期,两组仍保持这一规律。尽管对照组与实验组的红细胞变形指数和渗透脆性在保存期间差异不大,但在保存的d1和d7,对照组的溶血率仍明显高于实验组,分别为(0.070±0.039)vs(0.045±0.039)%和(0.116±0.066)vs(0.070±0.055)%。另外,在排除红细胞浓度的影响后,保存过程中对照组的葡萄糖的代谢速率仍明显快于实验组,为(2.43±0.66)vs(1.93±0.41)mmo L/L/1012个红细胞。结论 2组悬浮红细胞相比,添加正常比例1.5倍的MAP制备的西藏拉萨高海拔的悬浮红细胞的红细胞数、Hb浓度、Hct和血液粘度都明显降低,有利于临床输注。除此之外,红细胞保存液的增加有利于减缓葡萄糖的消耗和减少溶血,对高海拔地区悬浮红细胞的保存质量有一定的改善作用。展开更多
文摘Dielectric properties or kuamn red blood cell (RBC) suspension (ltematocrit 50%) from 243 healthy persons (120 males, 123 remales) were measured at 25Cin the frequency range rrom 1 to 500MHz, and analysed statistically. The measuringsystem controlled by an IBM-PC computer was composed or a network analyzer(HP4195A), coaxial line sensor and a temperature controlling set. The results showedthat the dielectric properties did not depend on either sex or blood group. However, agehad definite erfect. There was a critical age around 49 years when the dielectric data ofhuman RBC suspensions varied signiricantly.
文摘Diagnosis of Trypanosoma brucei rhodesiense human African trypanosomiasis requires demonstration of parasites in body fluids by microscopy. The microscopy methods that are routinely used are difficult to deploy in resource-limited settings due to practical challenges, including lengthy and tedious procedures, and the need for specific equipment to centrifuge samples in glass capillary tubes. We report here on a study that was conducted in a rural region of eastern Uganda to evaluate new methods that take advantage of a field-deployable LED fluorescence microscope. Examination of acridine orange-stained blood smears by LED fluorescence microscopy resulted in a diagnostic accuracy that was similar to that of routine methods, while the time needed to identify parasites was shortened significantly. These findings make these new microscopy methods attractive alternatives to procedures that are currently used for diagnosis of T. b. rhodesiense human African trypanosomiasis.
文摘Background: Confirmatory diagnosis of Trypanosoma brucei gambiense human African trypanosomiasis (HAT) is based on demonstration of parasites by microscopy. However, the sensitivity of routine microscopy methods is very low, and many cases are missed and left untreated. A clinical study was conducted in the Democratic Republic of the Congo to evaluate the accuracy of improved microscopy methods in diagnosis of HAT. These included examination by fluorescence microscopy (FM) of acridine orange (AO) stained smears of whole blood and smears made following a new procedure for concentrating trypanosomes by selective lysis of red blood cells (RBC). Methodology/Principal Findings: Venous blood was collected from 213 HAT cases, 101 HAT suspects and 95 controls and used to determine the accuracy of four microscopy methods: bright field microscopy of Giemsa-stained thick blood smears, FM of AO-stained thick blood smears, FM of AO-stained thick blood smears prepared after RBC lysis and concentration, and FM of AO-stained thin blood smears prepared after RBC lysis and concentration. The sensitivity of FM using thick blood smears stained with AO was 3 times higher than bright field microscopy using Giemsa-stained thick blood smears [19.7% (95% CI: 14.9% - 25.6%) versus 6.1% (95% CI: 3.6% - 10.2%)]. When the RBC lysis and concentration procedure was included, sensitivity of the test was further enhanced to 23.0% (95% CI: 17.9% - 29.1%) with thick blood smears and 34.3% (95% CI: 28.2% - 40.9%) with thin blood smears. Specificity of all four microscopy methods was 100% (95% CI: 96.1% - 100.0%). However, the miniature anion exchange chromatography technique (mAECT) and capillary tube centrifugation (CTC) method remained more sensitive. Conclusions: These new methods have practical advantages, including shorter staining time, ease of demonstration of parasites, and the possibility of archiving slides. They could, therefore, be alternative methods to improve case detection where concentration procedures such as mAECT or CTC are not performed.
基金the National Natural Science Foundation of China(No.82172114)the Anhui Provincial Natural Science Foundation for Distinguished Young Scholars(No.2108085J37).
文摘Cryopreservation of red blood cells(RBCs)provides great potential benefits for providing transfusion timely in emergencies.High concentrations of glycerol(20%or 40%)are used for RBC cryopreservation in current clinical practice,which results in cytotoxicity and osmotic injuries that must be carefully controlled.However,existing studies on the low-glycerol cryopreservation of RBCs still suffer from the bottleneck of low hematocrit levels,which require relatively large storage space and an extra concentration process before transfusion,making it inconvenient(time-consuming,and also may cause injury and sample lose)for clinical applications.To this end,we develop a novel method for the glycerol-free cryopreservation of human RBCs with a high final hematocrit by using trehalose as the sole cryoprotectant to dehydrate RBCs and using core–shell alginate hydrogel microfibers to enhance heat transfer during cryopreservation.Different from previous studies,we achieve the cryopreservation of human RBCs at high hematocrit(>40%)with high recovery(up to 95%).Additionally,the washed RBCs post-cryopreserved are proved to maintain their morphology,mechanics,and functional properties.This may provide a nontoxic,high-efficiency,and glycerol-free approach for RBC cryopreservation,along with potential clinical transfusion benefits.
文摘目的比较添加不同比例的MAP保存液对西藏拉萨地区悬浮红细胞的保存质量的影响。方法将西藏自治区血液中心采集的400 m L全血(共6袋),每袋平均分成2份,每份再分别离心分离去除血浆,按全血与保存液的不同比例包括4∶1和4∶1.5,每份红细胞分别加入50 m L(对照组)和75m L MAP保存液(实验组)制备得到悬浮红细胞,每份分别分装到4个50 m L小袋,于1、7、14、35 d分别检测血常规、p H值、全血粘度、电解质、葡萄糖、乳酸、游离Hb、红细胞渗透脆性、红细胞变形性等指标。结果在保存d1,实验组的红细胞数、Hb浓度、Hct、血液粘度都明显低于对照组,分别为(5.66±0.49)vs(6.72±0.68)×1012/L,(178.2±13.03)vs(212.6±14.2)g/L,(63.7±5.9)%vs(53.7±4.7)%,(6.99±1.82)vs(11.60±2.86)10s-1,至保存末期,两组仍保持这一规律。尽管对照组与实验组的红细胞变形指数和渗透脆性在保存期间差异不大,但在保存的d1和d7,对照组的溶血率仍明显高于实验组,分别为(0.070±0.039)vs(0.045±0.039)%和(0.116±0.066)vs(0.070±0.055)%。另外,在排除红细胞浓度的影响后,保存过程中对照组的葡萄糖的代谢速率仍明显快于实验组,为(2.43±0.66)vs(1.93±0.41)mmo L/L/1012个红细胞。结论 2组悬浮红细胞相比,添加正常比例1.5倍的MAP制备的西藏拉萨高海拔的悬浮红细胞的红细胞数、Hb浓度、Hct和血液粘度都明显降低,有利于临床输注。除此之外,红细胞保存液的增加有利于减缓葡萄糖的消耗和减少溶血,对高海拔地区悬浮红细胞的保存质量有一定的改善作用。
