阻断CD18介导的白细胞粘附对岛状皮瓣成活的影响

研究白细胞白细胞粘附在缺血再灌注损伤中的作用。方法，应用大鼠腹部岛状皮瓣模型，检测了皮瓣过氧化酶和丙二醛含量，观察了皮瓣的成活情况。结论ＣＤ１８介导 白细胞粘附参与了皮瓣再灌注损伤过程，抗ＣＤ１８单抗阻断白细胞附能减轻白细胞介导的组织损伤，并对岛状皮瓣具有保护作用。     

阻断CD_(18)介导的白细胞粘附对岛状皮瓣成活的影响

目的研究白细胞及白细胞粘附在缺血再灌注损伤中的作用。方法应用大鼠腹部岛状皮瓣模型,检测了皮瓣髓过氰化酶(MPO)和丙二醛(MDA)含量,观察了皮瓣的成活情况。结果与正常时相比,缺血8小时及再灌注1小时皮瓣 MPO 和 MDA 水平明显增高,而以抗 CD_(18)单抗阴断白细胞粘附可明显减轻这种变化,并有效地提高皮瓣的存活面积。结论 CD_(18)介导的白细胞粘附参与了皮瓣再灌注损伤过程,抗 CD_(18)单抗阻断白细胞粘附能减轻白细胞介导的组织损伤,并对岛状皮瓣具有保护作用。     

热应激预处理对皮瓣缺血再灌注损伤的影响及机制

目的　探索减轻皮瓣缺血再灌注损伤的有效措施。方法　采用大鼠腹部岛状皮瓣,制作活体原位热缺血模型,观察热缺血再灌注后皮瓣的成活率、皮瓣组织形态学改变,检测皮瓣超氧化物歧化酶（ Ｓ Ｏ Ｄ） 活性、丙二醛（ Ｍ Ｄ Ａ） 含量、 Ｈ Ｓ Ｐ７ ０ 表达。结果　缺血８ｈ 后再灌注,实验组皮瓣存活率明显高于对照组;与对照组相比,实验组皮瓣组织中 Ｓ Ｏ Ｄ 活性较高而 Ｍ Ｄ Ａ 水平较低;电镜显示,实验组皮瓣毛细血管内膜较完整,细胞肿胀轻,线粒体结构较稳定。结论　热应激预处理,能减轻缺血再灌注对皮瓣的损伤,对缺血再灌注皮瓣具有保护作用,其机制可能与热应激预处理抗自由基损害作用及维护细胞膜结构稳定有关。     

腹主动脉阻断导致内脏缺血再灌注损伤的研究

目的观察腹主动脉阻断所引起的肝、肾、小肠等内脏缺血再灌注损伤的改变。方法建立小猪腹主动脉阻断１小时的模型,检测在不同再灌注时点组织及血液中丙二醛（ＭＤＡ）和超氧化物歧化酶（ＳＯＤ）的变化,同时检测肝肾功能和动脉血气分析,观察动物术后的生存情况。结果与缺血前比较,大多数再灌注时点血、组织中ＭＤＡ明显升高,而ＳＯＤ明显降低（Ｐ＜０．０５）。在再灌注２小时,血中谷丙转氨酶（ＡＬＴ）、尿素氮（ＢＵＮ）、肌酐（ＣＲＥ）较缺血前明显升高（Ｐ＜０．０１）,代谢性酸中毒也极为明显。多数动物术后能够存活,但均出现下肢截瘫。结论腹主动脉阻断１小时能引起明显的内脏缺血再灌注损伤改变,多数内脏经处理后其损伤能够得到代偿恢复,而脊髓损伤恢复困难。     

阿魏酸钠对兔心肌缺血再灌注损伤MDA、SOD、ET和NO的影响

目的：观察阿魏酸钠对家兔心肌缺血再灌注损伤的保护效果。方法：１６只兔随机分为非缺血对照组（Ａ组），缺血再灌注常规治疗组（Ｂ组）及缺血于灌注阿魏酸钠治疗组（Ｃ组）。结果：与Ｂ组比较，Ｃ组心肌组织ＭＤＡ含量，血浆ＥＴ水平明显下降（Ｐ〈０．０１），心肌组织Ｔ－ＳＯＤ活性及血清ＮＯ水平显著增高（Ｐ〈０．０１），心肌组织超微结构损伤程度明显减轻，结论：阿魏酸钠可明显减轻家兔心肌缺血再灌注损伤。     

细胞粘附分子与脑缺血／再灌注损伤

细胞粘附分子（ＣＡＭｓ）是一大类可促进细胞粘附的分子的总称。ＣＡＭｓ所介导的白细胞与内此之间的粘附与缺血／再灌注脑损伤关系密切，ＣＡＭｓ的表达细胞因子的诱导。本文综述了缺血／再灌注脑２中多种粘附分子的重要意义及ＣＡＭｓ介导的内皮细胞、白细胞粘附增强在脑损伤中的 是生理过程，并探讨防止和减轻粘附分子作用的对策。     

尼群地平对缺血再灌注肺脂质过氧化反应的影响

目的探讨肺缺血再灌注损伤的发病机理，观察尼群地平的防治效果。方法７２只大鼠随机分成假手术组、缺血再灌注组和治疗组，采用肺在体温缺血再灌注损伤模型，于缺血４５分钟、再灌注后１小时、２小时、４小时取损伤肺组织测丙二醛（ＭＤＡ）、超氧化物歧化酶（ＳＯＤ）和总钙含量。结果缺血再灌注组各时相肺组织ＭＤＡ含量上升（Ｐ＜０．０５），ＳＯＤ含量显著下降（Ｐ＜０．０５），总钙含量显著升高（Ｐ＜０．０５），尼群地平可减轻肺组织ＭＤＡ和组织总钙含量的升高（Ｐ＜０．０５）。结论钙超载和自由基反应共同参与了肺缺血再灌注损伤，二者可能相互影响，相互促进；尼群地平通过阻滞钙通道，影响自由基系统而对缺血再灌注肺起保护作用     

去白细胞血液预防家兔缺血心肌再灌注损伤的实验研究

用涤纶纤维滤器去除再灌注血液中的白细胞，旨在检验其对缺血心肌再灌注损伤的保护效应。３２只家兔随机分成对照组和实验组，分别用全血和去白细胞血再灌注－离体心脏在２８℃下缺血６０ｍｉｎ后再灌注２０ｍｉｎ。结果表明：对照组白细胞计数、ＣＶＲ、ＣＰＫ及ＣＰＫ－ＭＢ显著高于实验组（Ｐ〈０．００１～Ｐ〈０．０５）；ＳＯＤ活性下降，ＭＤＡ含量明显增高与实验组相比有显著差异，分别为Ｐ〈０．０２及Ｐ〈０．０５。线粒体     

丹参对肢体缺血再灌注脂质过氧化反应影响的临床观察

目的：临床观察丹参对肢体缺血再灌注脂质过氧化反应的效果。方法：选择１６例肢体手术需充气带加压肢体止血的患者，随机分为对照组（ｎ＝８）和治疗组（ｎ＝８）。治疗组病人术前１０分钟静脉滴入复方丹参注射液（４００ｍｇ／ｋｇ），对照组病人给等量平衡液。肢体缺血前、再灌注后３０分钟、９０分钟、１８０分钟分别检测血ＭＤＡ、ＣＰＫ和ＳＯＤ。结果：肢体缺血再灌注３０分钟、９０分钟、１８０分钟与缺血前比较，血ＭＤＡ和ＣＰＫ含量升高，ＳＯＤ含量下降。治疗组缺血再灌注同时间，血ＭＤＡ含量明显低于对照组（Ｐ值＜０．０１）；ＣＰＫ值低于对照组（Ｐ值＜０．０５）；ＳＯＤ活性逐渐上升，１８０分钟高于对照组（Ｐ值＜０．０５）。结论：丹参有抗脂质过氧化作用，降低ＣＰＫ值，提高ＳＯＤ活性，能有效防治肢体缺血再灌注损伤。     

肢体缺血再灌注导致脂质过氧化增强和血栓素A2合成增加的研究

骨骼肌缺血再灌注可导致肌肉微血管的实质损伤，观察了肌肉缺血再灌注时脂质过氧化物（ＬＰＯ）和ＴｘＡ２与ＰＧＩ２的代谢状况。缺血组家兔（ｎ＝６）。双后肢缺血２小时。再灌注２小时后，左股薄肌丙二醛（ＭＤＡ）含量，下腔静脉血ＭＤＡ和乳酸浓度均显著高于对照组（ｎ＝６）。再灌注后１０和３０分钟，缺血组血中ＴｘＢ２水平和ＴｘＢ２／６－ｋｅｔｏ－ＰＧＦ１ａ比率明显增高，再灌注后血中ＳＯＤ活性和６－ｋｅｔｏ－ＰＧＦ     

Effect of superoxide dismutase for improvement of survival of ischemic reperfused island skin flap]

Using a rat model, we evaluated the effect of SOD on the survival of ischemic reperfused island skin flaps. In experiment 1, the oxygen free radical concentration in the flaps was measured by the technique of ESR. The results showed that the oxygen free radical concentration in ischemic reperfused flaps was significantly higher than in the corresponding control flaps (P less than 0.001). In experiment 2, the flaps were perfused with SOD (2000 U in 1 ml saline) before reperfusion after 8 hours of ischemia. Seven days after operation, the area of flap survived in the test group was significantly larger than in the control group (P less than 0.0005). The obtained data demonstrated that the generation of oxygen free radical increases with time during ischemia reperfusion in island skin flap and the role of oxygen free radical in tissue injury following ischemia and reperfusion. The use of SOD can enhance the survival of ischemic island skin flap.     

阿魏酸钠对移植皮瓣缺血再灌注损伤保护的实验研究

目的：通过建立大鼠皮瓣移植损伤的动物模型,观察阿魏酸钠对皮瓣存活率的影响。方法：利用H＆E染色分析皮瓣的损伤程度,利用免疫组化检测皮瓣组织中COX-2及HO-1的表达水平,利用ELISA法检测皮瓣组织中MPO、MDA、NO的含量以及外周血中TNF-α的表达水平。结果：在移植皮瓣缺血再灌注损伤模型中,相比于生理盐水处理组,阿魏酸钠处理可显著提高皮瓣的存活率,同时上调皮瓣组织中HO-1的表达水平,抑制COX-2通路的活化。在阿魏酸钠的作用下,皮瓣组织的MPO、MDA的含量明显下降,同时NO的合成增加,阿魏酸钠可显著抑制外周血中TNF-α的表达水平。结论：阿魏酸钠对移植皮瓣缺血再灌注损伤具有明显的保护作用,其作用机制与减少炎症反应,抑制氧化应激损伤密切相关。     

缺血-再灌注损伤对扩张皮瓣转移术后的影响

目的：探讨缺血-再灌注损伤对扩张皮瓣转移术后的影响。方法：以实验兔每侧腹壁浅动脉为中线,于两侧腹部植入50ml软组织扩张器各一只,术后定期注水扩张至80ml为止。分别于扩张皮瓣转移前、转移后1h、24h、72h检测腹壁浅动脉血流速度,切取皮瓣远端组织在200倍光镜下进行白细胞计数,检测皮瓣组织中丙二醛（MDA）、髓过氧化物酶（MPO）含量。结果：扩张皮瓣转移前腹壁浅动脉的血流速度为（13.2±0.78）cm/s,光镜下白细胞计数为（8.33±2.61）个,皮瓣组织内MDA含量为（1.72±0.57）nmol/mgprot,MPO含量为（126.50±20.70）U/g。皮瓣转移术后1h血流速度为（6.22±0.93）cm/s,白细胞计数为（19.08±4.94）个,MDA含量为（4.05±0.67）nmol/mgprot,MPO含量为（349.42±27.27）U/g。皮瓣转移术后24h血流速度为（8.37±0.56）cm/s,白细胞计数为（60.17±6.24）个,MDA含量为（6.68±0.73）nmol/mgprot,MPO含量为（558.08±26.99）U/g。皮瓣转移术后72h血流速度为（17.36±1.06）cm/s,白细胞计数为（34.00±3.79）个,MDA含量为（2.51±0.41）nmol/mgprot,MPO含量为（215.92±25.97）U/g。结论：在扩张皮瓣转移术后发生缺血-再灌注的过程中,皮瓣组织发生再灌注损伤。     

Prevention of reperfusion injury of an ischemic flap: an experimental study]

Oxygen-derived free radicals are important mediators of tissue injury in experimental island skin flaps that have been subjected to prolonged ischemia (vascular occlusion) followed by reperfusion. In this study, the role of oxygen free radical scavenger, SOD, and a herb, salvia miltiorrhiza, in the protection of cellular damages during total ischemia and reperfusion was study in the epigastric island skin flaps in experimental rats with electron microscopy and the assessment of survival of the flaps. Control flaps subjected to 10 hours of total vascular occlusion showed a high incidence of necrosis when followed for 7 days following release of the vascular occlusion. Treatment with superoxide dismutase and salvia miltiorrhiza prior to the onset of reperfusion significantly enhanced island flap survival to 72.5% (P < 0.001) and to 64.2% (P < 0.05), respectively. The conclusions are: 1. Reperfusion for 10 hours following ischemia for 8 hours in the epigastric island flaps of the rats greatly exaggerated the original injury. 2. SOD and salvia miltiorrhiza may protect the flaps from such injury considerably and enhanced flap survival.     

热应激预处理对皮瓣缺血再灌注损伤的影响及机制

OBJECTIVE: This study was to develop a new method that can lessen ischemia reperfusion injury and improve the survival of the island flap. METHOD: A right lower abdominal island flap was created in the SD rat according to the protocol of Harashina. Animals were divided into 2 groups (heat-shock pretreatment and control groups). The island flap viability and electronic microscopical appearance of flap tissue were evaluated following ischemia reperfusion injury. In order to explore the mechanism of this phenomenon, we examined the contents of HSP70 and measured the levels of SOD and MDA of the flap at various times. RESULTS: Compared with the control group, SOD activities of the flap were higher, and MDA content was lower. Survival rate of the island flap with heat-shock pretreatment was significantly increased (P < 0.01). CONCLUSION: The heat-shock pretreatment can lessen ischemia reperfusion injury and improve the survival of the island flap. It is suggested that the mechanism be related to following aspects: 1. The heat-shock pretreatment maintains stability of cell's function and structure. 2. It may increase the ability to catabolize free radicals by antioxidative enzymes.     

The effect of a free-radical scavenger, N-2-mercaptopropionylglycine, on the survival of skin flaps

Oxygen free radicals may have an important role in tissue injury, which occurs on reperfusion of previously ischemic skin flaps. Therefore, therapy directed against the toxic effects of reactive oxygen species may protect skin flaps from ischemia/reperfusion injury. Various scavengers of oxygen free radicals have previously been reported to be effective in ameliorating ischemia/reperfusion injury. In the present study, N-2-mercaptopropionylglycine (MPG), a free-radical scavenger, was evaluated for its effectiveness in limiting the extent of necrosis resulting from ischemia/reperfusion injury in rat skin. Island skin flaps were elevated in the abdomen and groin based on an inferior epigastric neurovascular pedicle. The venous drainage from the flap was occluded for 7 hours, and reperfusion was established. The majority of flaps in the control group exhibited complete necrosis on Day 7 postoperatively. Treatment with systemic MPG (20 mg/kg of body weight) significantly improved flap survival from 22 to 71% (p less than 0.01) when administered at the time of reperfusion. However, MPG administered 1 hour after reperfusion did not influence the survival of the flaps. The results suggest that MPG may exert its beneficial effects on flap survival by scavenging oxygen free radicals formed at the time of reperfusion following prolonged ischemia.     

Protective effect of fucoidin (a neutrophil rolling inhibitor) on ischemia reperfusion injury: experimental study in rat epigastric island flaps.

The objective of this study was to examine whether a decrease in neutrophil-mediated tissue injury using Fucoidin, a nontoxic neutrophil rolling inhibitor, would improve flap survival in an island flap model after ischemia-reperfusion. Myeloperoxidase activity (an indirect index of tissue neutrophil count) and malondialdehyde (an indicator of lipid peroxidation), the degree of neutrophil infiltration by direct counting, and macroscopic flap survival were assessed in the flap after arterial ischemia-reperfusion. Epigastric island skin flaps were elevated in 56 rats. The first group of 21 rats was subjected to 6 hours of arterial ischemia. The second group of 21 rats was subjected to 10 hours of arterial ischemia, and the rest of the rats were used as nonischemic controls (sham flaps). For inhibiting neutrophil rolling, a nontoxic polysaccharide agent-Fucoidin-was used. Each ischemic group was divided further into three subgroups: Subgroup I (control rats) received saline, subgroup II received 10 mg per kilogram Fucoidin, and subgroup III received 25 mg per kilogram Fucoidin before reperfusion. The results were evaluated as tissue neutrophil counts, tissue malondialdehyde content, tissue myeloperoxidase activity, and flap survival. Neutrophil counts and tissue myeloperoxidase activity were decreased significantly (p <0.001) in subgroup III, but lipid peroxidation by means of tissue malondialdehyde content was not affected by Fucoidin administration. The authors conclude that administration of Fucoidin before reperfusion can limit tissue injury apparently by inhibiting neutrophil rolling in a dose-dependent manner.     

Improved survival in free skin flap transfers in rats

We have demonstrated previously that oxygen-derived free radicals are important mediators of tissue injury in experimental island skin flaps that have been subjected to prolonged ischemia (vascular occlusion) followed by reperfusion. In this study the role of oxygen free radicals in ischemia/reperfusion injury has been investigated in free flap transfers. Groin skin flaps were harvested, stored at room temperature for 21 to 24 hours, and transplanted to the contralateral groin. These free flap transfers normally exhibit a high incidence of complete necrosis. Treatment before the onset of reperfusion with a single dose of superoxide dismutase (SOD), a scavenger of superoxide radicals, increased the survival rate of these skin flaps from 38% in the control group to 76% (p less than 0.025). Tissue levels of SOD were measured before ischemia, after ischemia but before reperfusion, and 30 minutes after reperfusion: untreated flap tissues, which were destined to undergo necrosis, exhibited a significant decrease in SOD activity after reperfusion, whereas SOD-treated flap tissues, destined to survive, demonstrated increased enzyme activity. High levels of tissue SOD activity thus appeared to be associated with improved flap survival. The results have significant clinical implications with regard to organ preservation and transplantation.