Haemoglobin transfusion threshold in very preterm newborns: a theoretical framework derived from prevailing oxygen physiology

The overwhelming majority of very preterm newborns receive at least one transfusion during their in hospital stay. However, despite two recent randomised trials, the appropriate haemoglobin transfusion threshold in these high risk infants remains unclear. Typically, clinicians consider gestation, chronologic age and illness severity in order to determine the need for transfusion. There is, however, no simple way to balance these heterogeneous variables in order to arrive at a transfusion threshold without considering the prevailing oxygen physiology. This is particularly important during the transition to extra-uterine life, a time when the risk of brain injury is highest. We hypothesise that dysregulated cerebral oxygen handling, characterised by restricted oxygen consumption from suboptimal oxygen delivery increases the risk of hypoxic ischaemic brain injury in very preterm newborns and is the single common patho-physiologic process underlying early acquired brain injury in the preterm newborn. Our proposed framework, based on the physiology of oxygen handling, considers the prevailing oxygen kinetics in the very preterm newborn as a means of deriving the appropriate Hb transfusion threshold thereby balancing oxygen delivery and consumption and avoiding hypoxic ischaemic early brain injury. Manipulation of the oxygen delivery equation, with consideration of the likely chronologic changes to cardiac output in particular, permit derivation of a transfusion threshold in the first week of life and represents a novel therapeutic intervention aimed solely at prevention of early acquired brain injury and its associated long term neuro-developmental burden.     

肌酸激酶和血红蛋白在湿热环境训练监控中的意义

目的通过人体湿热环境下的体能训练与测试,检测人员血清中肌酸激酶和血红蛋白的水平,研究其与运动能力强弱、运动潜力大小和对外界环境的适应习服程度的相关性.方法选取某军校45名青年男性学员为受试对象,随机分为训练组和常规对照组,对训练组进行8周湿热环境负重跑训练,训练结束后行负重跑测试,测定其运动后血肌酸激酶和血红蛋白,同时记录运动成绩和运动后的肛门温度,分析计算两组的生理、生化指标的变化趋势和相关关系.结果训练后训练组的12 min负重跑成绩明显好于对照组,而运动后肛温则明显低于对照组;训练结束时两组的血红蛋白水平无明显差别,但训练组的运动后血肌酸激酶升高程度明显低于对照组.结论在相同海拔下,血红蛋白对环境习服和运动水平不具有指示意义,而运动后的血肌酸激酶水平可作为指示运动能力、习服程度和运动损伤的有益监控指标.     

Hb H Disease Results from Compound Heterozygosity of – –SEA and –αMAL3.5 in a Chinese Family

The α⁺-thal deletion of 3.557?kb (NG_000006.1: g.32745_36301del, –α^MAL3.5), involving the entire α2-globin gene, was identified in a Chinese family by multiplex ligation-dependent probe amplification (MLPA) followed by gap-polymerase chain reaction (gap-PCR) and sequencing. The proband, a compound heterozygote for this mutant gene and the Southeast Asian (–?–^SEA; NG_000006.1: g.26264_45564del19301) deletion, had a phenotype of Hb H disease [hemoglobin (Hb) 7.6?g/dL, mean corpuscular volume (MCV) 60.0 fL, Hb H (β4) 0.7%, Hb Bart’s (γ4) 2.4% and Hb A₂ 1.1%]; one of her sisters with same genotype showed a similar phenotype. Another two family members, who were carriers of this mutant gene, had a hematological phenotype of a silent α-thal. The 5' and 3' breakpoints of this deletion are located at the Y2 and Y1 boxes, respectively, therefore, it probably originated from an unequal crossover between these two homologous boxes. This mutation constitutes an additional heterogeneous defect causing α-thal in the Chinese population and would be valuable for elucidating the arrangement in the human α-globin gene cluster.     

4种方法校准血细胞分析仪红细胞压积的结果比较及偏倚分析

目的:评价血红蛋白/平均红细胞血红蛋白浓度(Hemoglobin,Hb/Hean corpuscular hemoglobin concentration,MCHC)比值法(Hb/MCHC法)校准血细胞分析仪红细胞压积(Hematocrit,Hct)的可靠性.方法:分别用Hb/MCHC法、配套校准品、非配套校准品和质控品对3台血细胞分析仪Hct进行校准,分析比较各仪器对Hct为低值、中值和高值的新鲜血标本测定结果的可比性和偏倚.结果:用Hb/MCHC法对新鲜血Hct定值后校准各仪器,3台仪器测定新鲜血Hct结果间的差异均无统计学意义(P＞0.05),偏倚均＜1.5%.与Hb/MCHC法校准仪器相比较,2台用配套校准品校准的仪器测定Hct结果间的差异均无统计学意义(P＞0.05),偏倚均＜1.0%;无配套校准品的1台仪器测定结果明显增高,其差异有统计学意义(P＜0.05),偏倚达7.14%.用非配套校准品校准的2台仪器测定结果与配套校准品校准仪器的结果差异均有统计学意义(P＜0.05),偏倚分别达6.78%和7.76%.3台用质控品校准的仪器与Hb/MCHC法校准仪器的测定结果差异均有统计学意义(P＜0.05),偏倚达7.56%.结论:血细胞分析仪Hct的校准应使用配套校准品或可靠的定值新鲜血,在配套校准品难于及时获得或缺乏时,Hb/MCHC法可作为新鲜血Hct定值的参考方法.     

营养风险筛查2002在老年恶性肿瘤患者化疗中的应用研究

目的:了解NRS2002在预估老年肿瘤患者化疗不良反应的潜在作用及相关影响因素,探讨潜在的化疗不良事件的干预措施。方法:2016年7月至2017年2月选择在我院肿瘤内科就诊的149例老年肿瘤化疗患者作为研究对象,入院24 h内完善NRS2002评分及相关病史采集,评估化疗不良反应分级。结果:149例患者中,有营养不良风险（NRS2002评分≥3分）的老年肿瘤患者占43.6%,无营养风险占56.4%,其中年龄、肿瘤类别分布、化疗不良反应分级、WBC、Hb、Scr、UA及血清K+组间差异有统计学意义（P<0.05）。相关性分析结果显示:不良反应分级与NRS2002评分呈正相关性,与WBC、Hb、SCr、UA及K+、Ca2+呈负相关性。线性回归分析提示NRS2002评分的高低与老年肿瘤患者化疗不良反应分级显著正相关,而SCr则是一个负性预测因子。结论:NRS2002可准确预估老年肿瘤化疗患者面临的潜在化疗风险,早期纠正贫血或可缩小老年肿瘤患者的化疗不良反应风险;肾功不全不再是化疗的绝对禁忌证。     

Chemotactic factor concentration gradients in chemotaxis assay systems

In most assays of chemotaxis the gradient of the chemotactic factor is established and later destroyed by its diffusion through some matrix. The characteristics of the gradient depend upon the geometry of the assay system, the diffusion coefficient of the chemotactic factor and the concentration of the chemotactic factor added. We have solved the diffusion equations to characterize the gradients present in 3 assays of ceemotaxis in current use: the millipore, under-agarose and visual assay systems. In each case the solutions are presented for various assay times and for chemotactic factors with various diffusion coefficients.     

Do retinal and spinal projections overlap within the turtle thalamus?

The spinal and retinal projections to the turtle thalamus were studied using the autoradiographic tracing technique. Particular attention is given to the regions receiving both spinal and retinal projections: the ovalis complex and a perirotundal stripe. Spinal and retinal projections do not overlap significantly in either of these regions. In the perirotundal stripe there appears to be little likelihood of convergence of these projections on single neurons. In the ovalis complex, the most densely and the most consistently innervated thalamic region, however, the respective spinal and retinal target areas are located immediately adjacent to each other and low order somatosensory and visual projections may converge on single neurons with dendrites extending into both the spinal and retinal terminal arborizations. The ovalis complex in the turtle may be compared with the ventral part of the mammalian lateral geniculate nucleus. Both these nuclei receive spinal and retinal projections and both, reportedly, do not project to the telencephalon. The findings are discussed in relation to the possible evolution of the specific thalamic sensory nuclei in higher mammals as well as to the prosencephalic processing of somatosensory and visual information in turtles and mammals.     

A study of an educational intervention to decrease inappropriate preoperative autologous blood donation: its effectiveness and the effect on subsequent transfusion rates in elective hysterectomy

BACKGROUND: Decreasing the overcollection of preoperative autologous blood is difficult to achieve. The purpose of this study was to determine whether an educational intervention designed to outline the risks of preoperative autologous collection can decrease such donations and, if so, to determine how this decrease will affect subsequent transfusion rates. STUDY DESIGN AND METHODS: An educational intervention consisting of a didactic presentation to the Department of Gynecology staff about the risks and benefits of autologous blood was implemented. Written material with similar information was given to patients. Subsequently, the percentage of patients donating autologous blood, the number of autologous units donated, and the rates of transfusion in patients eligible for autologous donation who were admitted for elective abdominal or vaginal hysterectomy were measured. These rates were compared to those in similar patients admitted in the 2 years before the educational intervention. RESULTS: After an educational intervention, the proportion of patients donating autologous blood decreased from 53 percent to 26 percent (p<0.01), and the number of units collected per patient decreased from 0.86 to 0.31 (p<0.01); this resulted in a savings of 80 autologous donations per year. Despite no difference in estimated blood loss (p = 0.46), the overall transfusion rate decreased from 10 percent to 3.7 percent (p = 0.03), while the allogeneic transfusion rate demonstrated no significant change (1.1% vs. 2.2%; p = 0.40). CONCLUSIONS: Unnecessary preoperative autologous donations by elective hysterectomy patients can be decreased by educating physicians and patients about the risks of preoperative autologous blood donation. Decreasing such unnecessary donations can decrease the subsequent autologous transfusion rate, with its attendant risks, without increasing the risk of allogeneic transfusion.     

A new apheresis procedure for the preparation of high-quality red cells and plasma

BACKGROUND: Multicomponent apheresis is an alternative way of preparing blood components that avoids the delay between collection and separation seen with standard whole-blood techniques. STUDY DESIGN AND METHODS: An apheresis device has been modified to facilitate the combined collection of a unit (250 mL) of red cells (RBCs) and a high-volume unit (475 mL) of plasma. The procedure, using 8-percent ACD-A, has been tested in two European blood centers. Each center performed 20 procedures for in vitro evaluation of collected RBCs and plasma and 10 procedures for evaluation of in vivo RBC recovery. All RBCs were white cell reduced by filtration. One-half of the RBC units were stored in the additive solution Adsol and one-half in another such solution (Erythro-Sol). RESULTS: The target volumes of RBCs and plasma were obtained in 27 minutes (range, 20-44 min) by using three to six cycles in a single-needle procedure. Saline (275 mL) was used to replace fluid volume withdrawn in excess of standard whole-blood donation. No side effects occurred, with the exception of minor signs of hypocalcemia. RBC ATP was well maintained (>65% at Day 42) during storage; 2,3-DPG was less well maintained, with virtually none remaining at Day 21 in either Adsol or Erythro-Sol. The RBC in vivo recoveries, after 42 days of storage at 4+/-2 degrees C determined by the single-label method, were 86.7+/-7.2 percent (Erythro-Sol) and 84.4+/-8.1 percent (Adsol). Mean plasma factor VIII levels were >100 percent in all test groups. CONCLUSION: A novel automated technique for the simultaneous collection and preparation of RBCs and plasma has been evaluated. The apheresis procedure was acceptable and well tolerated by donors, and it resulted in high-quality blood components. Further optimization of the system should yield a practicable component suitable for routine use in blood banks.