心肌缺血预适应对急性心肌梗死病人的影响

目的 对首次急性心肌梗死（AMI）发生前24h、24h～48h、〉48h有无发作过心绞痛的病人的临床状况及近期预后进行评价。方法 158例AMI病人分为两组，缺血预适应组（观察组）46例，其中24h内发生心绞痛ll例，24h～48h内发生心绞痛6例，〉48h发生心绞痛29例；非心肌缺血预适应组（对照组）112侧。结果 观察组除〉48h外，均比对照组心肌梗死范围小（P〈0，01），血浆肌酸磷酸激酶（CPK）、乳酸脱氢酶（LDH）、谷草转氨酶（AST）峰值低（P〈0．01），住院期间发生心功能不全、心源性休克、死亡等心脏事件发生率明显降低（P〈0．05）。结论 首次急性心肌梗死前48h以内发作的心绞痛对AMI心肌具有明显的保护作用，其机制可能与心肌缺血预适应有关。     

心肌缺血预适应对急性心肌梗死病人的影响

目的 对首次急性心肌梗死（ＡＭＩ）发生前２４ｈ、２４￣４８ｈ、大于４８ｈ有无发作过心绞痛的病人的临床状况及近期预后进行评价。方法 １５８例ＡＭＩ病人 分为缺血预适应组４６例,其中２４ｈ内发生心绞痛１１例,２４￣４８ｈ内发生心绞痛６例,大于４８ｈ发生心绞痛２９例;非预适应组１１２例;两组基本临床情况相似。结果 心肌皑 血预适应相比非缺血预适应组心肌梗死范围小（Ｐ〈０．０１）,血浆ＣＰＫ、ＬＤＨ、ＡＳ     

Extended criteria donor lung reconditioning with the organ care system lung: a single institution experience

Lung transplantation is a life‐saving procedure limited by donor's availability. Lung reconditioning by ex vivo lung perfusion represents a tool to expand the donor pool. In this study, we describe our experience with the OCS? Lung to assess and recondition extended criteria lungs. From January 2014 to October 2016, of 86 on‐site donors evaluated, eight lungs have been identified as potentially treatable with OCS? Lung. We analyzed data from these donors and the recipient outcomes after transplantation. All donor lungs improved during OCS perfusion in particular regarding the PaO₂/FiO₂ ratio (from 340 mmHg in donor to 537 mmHg in OCS) leading to lung transplantation in all cases. Concerning postoperative results, primary graft dysfunction score 3 at 72 h was observed in one patient, while median mechanical ventilation time, ICU, and hospital stay were 60 h, 14 and 36 days respectively. One in‐hospital death was recorded (12.5%), while other two patients died during follow‐up leading to 1‐year survival of 62.5%. The remaining five patients are alive and in good conditions. This case series demonstrates the feasibility and value of lung reconditioning with the OCS? Lung; a prospective trial is underway to validate its role to safely increase the number of donor lungs.     

Cold flush after dynamic liver preservation protects against ischemic changes upon reperfusion – an experimental study

Ex vivo machine perfusion of the liver after cold storage has found to be most effective if combined with controlled oxygenated rewarming up to (sub)‐normothermia. On disconnection of the warm graft from the machine, most surgeons usually perform a cold flush of the organ as protection against the second warm ischemia incurred upon implantation. Experimental evidence, however, is lacking and protective effect of deep hypothermia has been challenged for limited periods of liver ischemia in other models. A first systematic test was carried out on porcine livers, excised 30 min after cardiac arrest, subjected to 18 h of cold storage in UW and then machine perfused for 90 min with Aqix‐RSI solution. During machine perfusion, livers were gradually rewarmed up to 20 °C. One group (n = 6) was then reflushed with 4 °C cold Belzer UW solution whereas the second group (n = 6) remained without cold flush. All livers were exposed to 45 min warm ischemia at room temperature to simulate the surgical implantation period. Organ function was evaluated in an established reperfusion model using diluted autologous blood. Cold reflush after disconnection from the machine resulted in a significant increase in bile production upon blood reperfusion, along with a significant reduction in transaminases release alanine aminotransferase and of the intramitochondrial enzyme glutamate dehydrogenase. Interestingly, free radical‐mediated lipid peroxidation was also found significantly lower after cold reflush. No differences between the groups could be evidenced concerning histological injury and recovery of hepatic energy metabolism (tissue content of adenosine triphosphate). Post‐machine preservation cold reflush seems to be beneficial in this particular setting, even if the organs are warmed up only to 20 °C, without notion of adverse effects, and should therefore be implemented in the protocol.     

Controlled Oxygenated Rewarming of Cold Stored Liver Grafts by Thermally Graduated Machine Perfusion Prior to Reperfusion

The quality of cold‐stored livers declines with the extension of ischemic time, increasing the risk of primary dys or nonfunction. A new concept to rescue preserved marginal liver grafts by gentle oxygenated warming‐up prior to blood reperfusion was investigated. Porcine livers were preserved by cold storage (CS) in modified HTK‐solution for 18 h. Some grafts were subsequently subjected to 90 min of controlled oxygenated rewarming (COR) by machine perfusion with gradual increase of perfusate temperature up to 20°C or simple oxygenated machine perfusion in hypothermia (HMP) or subnormothermia (SNP). Graft viability was assessed thereafter by 4 h of normothermic blood reperfusion ex vivo. Endischemic tissue energetics were significantly improved by COR or SNP and to a notably lesser extent by HMP. COR significantly reduced cellular enzyme loss, gene expression and perfusate activities of TNF‐alpha, radical mediated lipid peroxidation (LPO) and increase of portal vascular perfusion resistance upon reperfusion, while HMP or SNP were less protective. Only COR resulted in significantly more bile production than after CS. Histological injury score and caspase 3‐activation were significantly lower after COR than after CS. Oxygenated rewarming prior to reperfusion seems to be a promising technique to improve subsequent organ recovery upon reperfusion of long preserved liver grafts.     

OKT-3-based reconditioning regimen for early graft failure in HLA-non-identical stem cell transplants

Primary non-engraftment or early rejection after transplantation of haematopoietic stem cells represent life-threatening complications of allogeneic stem cell transplantation. Management of early graft failure has been problematic, as the risk of fatal infectious complications increases with the time of pancytopenia and as a second transplant preceded by a conventional myeloablative conditioning regimen has been associated with high rates of cumulative organ toxicity. For paediatric patients with early graft failure following the transplantation of highly purified major histocompatibility complex (MHC)-disparate haematopoietic stem cells, we have evaluated an immunosuppressive OKT-3/methylprednisolone-based reconditioning regimen with low toxicity in preparation for a secondary transplant of purified haematopoietic stem cells from the same donor. This report presents the results from a 4-year pilot study including six patients with early graft failure. The results demonstrate that this antibody-based regimen can be used effectively to prepare patients for secondary transplantation. Successful engraftment after a second transplant procedure was achieved in five of these six high-risk patients. The median interval between first and second transplant was 27 d (range 22-51 d), and the median time for engraftment was 10 d (range 9-13 d). Chimaerism analysis of microsatellite regions by polymerase chain reaction (PCR) demonstrated complete donor chimaerism in four of these patients within the first month after secondary transplant and revealed mixed chimaerism in one patient who converted to complete chimaerism after T-cell add-back.     

瓦里安2300C/D型直线加速器低剂量率故障应急检修一例

此故障是瓦里安直线加速器常见故障之一。根据故障现象以及结合随机附带的电原理图,详细地阐述了具体检修过程。     

SOD在缺血预处理保护大鼠肝脏缺血再灌注损伤中的作用

目的 :探讨超氧化物歧化酶 (superoxidedismutase ,SOD)在缺血预处理保护肝脏缺血再灌注损伤过程中的作用。方法 :应用大鼠部分肝脏缺血再灌注损伤模型 ,检测缺血预处理组 (IP组 )、缺血再灌注组 (I/R组 )及对照组 (C组 )大鼠血清丙氨酸转氨酶 (alaninetransaminase,ALT) ,门冬氨酸转氨酶 (aspartatetransaminase ,AST)及乳酸脱氢酶 (lactatedehydrogenase ,LDH)水平与肝脏病理组织学改变 ,测定其肝脏组织SOD水平的变化并与单纯缺血预处理组 (OIP组 )大鼠进行比较。结果 :IP组的肝脏损害虽较C组重 ,但明显较I/R组轻 ,其 3种血清生化酶均显著低于I/R组 ;OIP组肝组织的SOD水平 (2 14 .95± 2 4 .38)NU/mgprotein均显著高于IP组 (172 .4 3± 15 .2 3)、I/R组 (16 4 .0 3± 30 .0 8)与C组 (16 7.0 3± 2 7.6 0 )NU/mgprotein (P <0 .0 1)。结论 :缺血预处理对大鼠肝脏缺血再灌注损伤具有保护作用 ,其机制与激活肝组织中的SOD有关