脑储备能力评价参数概述及对比

脑储备能力的减退是预示缺血性卒中发生的危险因素已得到证实，具有重要的临床意义。其评价参数多样，如脑血流量、脑血容量、平均通过时间、脑循环时间、临界关闭压、血管舒缩反应性、反应时间、氧摄取指数、脑氧代谢率等，但迄今尚没有统一的评价标准。本文就脑储备能力不同阶段的各评价参数及其临床意义作一综述。     

The use of the mechanical fragility test in evaluating sublethal RBC injury during storage

Background The mechanical fragility index (MFI) is an in vitro measurement of the extent of RBC sublethal injury. Sublethal injury might constitute a component of the RBC storage lesion, thus the MFI was determined serially during routine RBC storage. Methods Leucoreduced AS‐5‐ and SAGM‐preserved RBCs were stored under routine blood bank conditions. The mechanical fragility (MF) of each unit was serially measured during storage. Results For both AS‐5 and SAGM units, male and female RBCs demonstrated statistically significant increases in the MFI during storage. The MFI was significantly lower in AS‐5 units compared to SAGM units throughout storage. Female RBCs had significantly lower MFI vs. male RBCs in both AS‐5 and SAGM units at all times. No significant differences in MFI were observed between ABO groups for both genders for AS‐5 RBCs. Conclusions The MF of RBCs increases during storage. Both gender and preservation solution influenced the MFI; however, the male:female MFI ratios were similar at all time‐points and remained stable, suggesting that gender‐based biological differences exist independent of storage solution. The MF could be a useful test for evaluating the effect of novel interventions intended to mitigate the susceptibility of RBCs to sublethal injury during storage.     

The influence of platelet additive solutions on cytokine levels and complement activation in platelet concentrates during storage

BACKGROUND AND OBJECTIVES: The accumulation of platelet-derived cytokines in platelet concentrates (PC) during storage may contribute towards non-haemolytic transfusion reactions (NHTR). We investigated the effect of platelet storage medium on platelet activation, complement activation and cytokine levels in leucocyte-reduced PC. MATERIALS AND METHODS: Hyperconcentrated platelets (3000-6000 x 109/l) were collected by apheresis and diluted in 100% plasma, 70% PASIII, or 70% or 80% PASIII supplemented with magnesium and potassium (PAS IIIM). RESULTS: Levels of transforming growth factor-beta (TGF-beta) and regulated on activation, normal, T-cell expressed, and secreted (RANTES) increased during storage, as did the expression of P-selectin (CD62P), and were highest in PC stored in PASIII. In PC stored in PASIIIM, however, levels of TGF-beta and RANTES were not significantly different from PC stored in plasma. Levels of CD62P expression, however, remained higher in PASIIIM PC than in those stored in plasma by day 5, but were lower than PC stored in PASIII. C3a des arg levels increased during storage in all media with the exception of PASIII and, on day 7, were higher in PC stored in plasma compared to PC stored in the other media. CONCLUSIONS: Our results indicate that replacing plasma in PC with unmodified PASIII for storage results in higher levels of platelet-derived cytokines in PC. Furthermore, it appears that the nature of the medium used for storage of PC has a significant impact on platelet activation and cytokine levels of the PC. These implications should be taken into account when considering replacement of plasma with PAS.