Effect of a Stabilized Microbubble Contrast Agent on CW Ultrasound Induced Red Blood Cell Lysis In Vitro

Human red blood cells (RBCs) in vitro at various fractional hematocrits (HCTs) were exposed for 60–120 seconds in a dialysis tubing vessel to 1 MHz continuous wave ultrasound (0–5 W/cm² SPTA intensity); exposure vessels were either rotated at 200 rpm or stationary. Some RBC suspensions also contained Albunex® (ALX; a commercially-produced microbubble clinical ultrasound contrast agent) at final concentrations ranging from 0–41 μL/mL RBC suspension. Isonation was either by one transducer or by two opposing, continuously-gated, balanced transducers. For the vessel rotation / no rotation experiments, ultrasound-induced cell lysis was always increased with the ALX regimen relative to that of the no-ALX regimen at HCTs up to about 10%; at higher HCTs (including whole blood), ultrasound-induced hemol-ysis essectially ceased to occur. The data are consistent with reports of the ineffectiveness of continuous wave ultrasound at 3–5 W/cm² to lyse cells in vitro at physiological cell densities with or without echocontrast medium supplemantation.     

Effect of a Red Blood Cell Transfusion on Biological Markers Used to Determine the Cause of Anemia: A Prospective Study

Background

Blood test results required for the evaluation of anemia are considered difficult to interpret after red blood cell transfusion. However, this hypothesis is neither supported by a strong physiological rationale nor is it evidence based.

细胞粘附因子-1与恶性疟原虫感染红细胞结合位点的鉴定

目的　探索恶性疟原虫感染红细胞(PRBCs)与细胞粘附因子1(ICAM1)之间的结合位点,研制治疗脑型疟的抗粘附药物。　方法　以抗ICAM1(I区)的单抗15.2为靶,采用亲和筛选法对噬菌体随机十二肽库进行3轮筛选,通过ELISA、竞争抑制试验、dotELISA及Westernblotting鉴定获得的噬菌体短肽与单抗15.2之间的结合特性。对阳性克隆进行DNA序列测定,推导其十二肽的氨基酸序列并与ICAM1氨基酸全序列进行同源性比较。　结果　经3轮亲和筛选后,结合噬菌体得到良好富集。从第3轮洗脱液铺制的琼脂板中随机挑取30个噬菌体单克隆,ELISA检测有26个为阳性,阳性率达86.7%。竞争性ELISA显示多数阳性噬菌体能竞争抑制ICAM1与15.2单抗结合。DNA及氨基酸序列分析表明半数以上的噬菌体克隆表达十二肽KLYLIAEGSVAA,该短肽中K(XX)L(XXX)GSV与ICAM1的64～73位aa有50%的同源性。　结论　阳性噬菌体表达的短肽是15.2单抗所识别的模拟表位,K··L···GSV几个氨基酸可能对ICAM1与PRBCs的结合起重要作用     

The Role of Red Blood Cell Exchange Transfusion in the Treatment and Prevention of Complications of Sickle Cell Disease

Abstract: Patients with sickle cell disease have abnormal red blood cells (RBCs). This can cause chronic hemolytic anemia and vaso‐occlusion leading to tissue hypoxemia and organ dysfunction. RBC exchange transfusion can, without increasing the whole‐blood viscosity, quickly replace abnormal erythrocytes with normal and raise the hematocrit resulting in improved delivery of oxygen to hypoxic tissues. Unfortunately, transfusion can also be associated with complications. This paper reviews the role of transfusion, both simple and exchange, in the treatment and prevention of sickle‐related complications. The benefits of exchange versus simple transfusion and transfusion versus alternative therapies are discussed.     

Shortened Red Blood Cell Lifespan Is Related to the Dose of Erythropoiesis‐Stimulating Agents Requirement in Patients on Hemodialysis

Renal anemia is an important complication of chronic kidney disease (CKD). One of the most important complications of renal anemia is reduced red blood cell (RBC) lifespan, but there has been little research conducted into the causes of and treatments for this anemia. We measured alveolar carbon monoxide (CO) and then estimated RBC lifespan in patients on hemodialysis (HD). We also examined their requirement for erythropoiesis‐stimulating agents (ESA), HD dose, nutrition factors, iron metabolism factor, reticulocyte counts and % reticulocytes. We enrolled 140 patients undergoing intermittent HD; among this group, 31 were not administered ESA and the others were on ESA therapy. Twelve healthy volunteers served as controls. The RBC lifespans in the healthy volunteers and in the HD patients were 128 ± 28 and 89 ± 28 days (mean ± SD), respectively. The RBC lifespan significantly and negatively correlated with ESA requirement (r = ?0.489, P < 0.0001) in the HD patients. Other factors suspected to influence the RBC lifespan did not significantly correlate with the RBC lifespan in HD patients, in contrast to the correlation observed for S‐Cr, BUN, S‐ALB and total cholesterol vs. RBC lifespan. A shortened RBC lifespan seems to rather significantly affect the ESA requirement. Better nutritional status or active HD patients also seem to have longer RBC lifespans and lower ESA requirement.     

Characterization of Clonogenic Progenitors in Autologous Peripheral Blood Stem Cell Grafts: Evaluation of a Simple In Vitro Assay Suitable for Routine Clinical Use

Autologous peripheral blood stem cell (PBSC) transplantation has a low treatment-related morbidity and mortality when using appropriate criteria for patient selection and graft quality evaluation. It will be important to use simple and standardised procedures for evaluation of progenitor cell numbers when considering autografting in patients with malignant or non-malignant disorders and increased risk of prolonged posttransplant cytopenia. We determined the number of clonogenic cells in PBSC autografts after 7 days of In Vitro culture, and these results were compared with both the total number of colonies and the numbers of colony subsets in conventional 14 days colony assays (colony-forming unit granulocyte-erythrocyte-macrophage-megakaryocyte, CFU-GEMM; CFU-E, CFU-GM; CFU-megakaryocyte). The total colony number after 7 days of culture correlated significantly with (i) the CD34₊ cell number; (ii) the total colony number as well as the numbers of erythroid, nonerythroid and mixed colonies in a conventional assay using 14 days of culture; (iii) the number of megakaryocyte colonies. The total colony number after 7 days of In Vitro culture is a simple In Vitro parameter that seems to reflect the proliferative capacity of various progenitor subsets in PBSC autografts. This simple analysis may be used in combination with other In Vitro techniques (e.g. estimation of stem cell viability and CD34₊ cell subset analysis) for pretransplant evaluation of autografts. However, the possible clinical use of this parameter has to be examined in prospective clinical studies.     

Raman Spectroscopic Study of TiO2 Nanoparticles’ Effects on the Hemoglobin State in Individual Red Blood Cells

Titanium dioxide (TiO₂) is considered to be a nontoxic material and is widely used in a number of everyday products, such as sunscreen. TiO₂ nanoparticles (NP) are also considered as prospective agents for photodynamic therapy and drug delivery. These applications require an understanding of the potential effects of TiO₂ on the blood system and its components upon administration. In the presented work, we analyze the interaction of TiO₂ nanoparticles of different crystal phases (anatase and rutile) with individual rat Red Blood Cells (RBC) and the TiO₂ influence on the oxygenation state and functionality of RBC, estimated via analysis of Raman spectra of Hemoglobin (Hb) and their distribution along individual RBC. Raman spectral signals also allow localization of the TiO₂ NP on the RBC. No penetration of the NP inside RBC was observed; however, both kinds of TiO₂ NP adsorbed on the RBC membrane can affect the Hb state. Mechanisms involving the NP–membrane–Hb interaction, resulting in partial deoxygenation of Hb and TiO₂ photothermal effect on Hb under Raman laser excitation, are suggested. The possible influence on the safety of TiO₂ use in advanced medical application, especially on the safety and efficiency of photothermal therapy, is discussed.     

Evaluation of the Relationship Between Hb F Levels and Nucleated Red Blood Cells with Morbidity in Non Transfusion-Dependent Thalassemia Patients

Recognition of risk factors of morbidities in patients with β-thalassemia intermedia (β-TI) is an important issue that must be evaluated. Non transfusion-dependent thalassemia patients referred to the outpatient clinic of Shiraz University of Medical Science, Shiraz, South Iran were enrolled in this study between 2013 and 2014. Two peripheral blood smears were prepared for evaluating developmental stage of normoblasts. One hundred and thirty-one patients with ages ranging from 3 to 42 years (mean: 23.35?±?7.9) were selected. Sixty-seven patients had at least one morbidity (51.1%). Osteoporosis and gallstones were the most common morbidities (33.6 and 24.4%, respectively). In the univariate model, hemoglobin (Hb), ferritin, Hb F, developmental stage of normoblasts and hydroxyurea (HU) therapy did not differ between patients with and without morbidity (p?>?0.05) but mean age of patients and mean number of normoblasts were higher in patients with morbidity (p?=?0.026 and p?=?0.012, respectively). In the regression model, sex and splenectomy status were different between patients with and without morbidity. It seems that females and splenectomy are risk factors for morbidity in non transfusion-dependent thalassemia patients. [Sex: odds ratio (OR)?=?2.21, 95% confidence interval (95% CI): 1.04-4.72, p?=?0.39. Splenectomy: OR = 3.10, 95% CI: 1.12-8.59, p?=?0.029.] This study shows that Hb F level and developmental stage of normoblasts does not effect the incidence of morbidities in non transfusion-dependent thalassemia patients but sex and splenectomy were effective factors in development of morbidities. Thus, splenectomy should be avoided as much as possible in patients with non transfusion-dependent thalassemia.     

Prevalence and trend of HIV infection among voluntary blood donors in China since implementation of the Blood Donation Law: a systematic review and meta‐analysis

Objective  In 1998, the Blood Donation Law was enacted in China in response to the outbreak of HIV endemic in central rural China as a result of unhygienic and commercial blood collection. This study aims to provide a first comprehensive review of available data on the prevalence, trend and other epidemiological characteristics of HIV infection among voluntary blood donors since 1998. Methods  Major English and Chinese databases were searched and a systematic review was constructed. Pooled infection rates by province and year were calculated using random‐effect or fixed‐effect models. Results  A total of 87 studies met our inclusion criteria. A total of 2573 HIV‐positive cases were identified among voluntary blood donors in the past 10 years; the pooled prevalence was 13.22/100 000, with a range of 0.74–125.97 per 100 000. Among the 24 provinces that reported yearly data, the prevalence of HIV increased from 5.62/100 000 to 28.90/100 000. The male‐to‐female ratio was 2.8; about 60% were below the age of 30 years. Conclusions  The prevalence of HIV in voluntary blood donors has risen steadily and fast. Efficient measures need to be taken urgently to prevent HIV test‐seeking through blood donor programmes, to promote voluntary blood donation in low‐risk groups and to enforce the Blood Donation Law strictly.