骨骼肌缺血再灌注损伤的防治进展

缺血再灌注损伤是组织缺血一段时间后,血流重新恢复造成的组织损伤。近年来关于防治骨骼肌缺血再灌注损伤的研究日益增多,本文就骨骼肌缺血再灌注损伤的防治方案进行综述。     

Growth hormone reduces tissue damage in rat ovaries subjected to torsion and detorsion: biochemical and histopathologic evaluation

Objective

To evaluate the effects of growth hormone (GH) as an antioxidant and tissue-protective agent and analyse the biochemical and histopathological changes in rat ovaries due to experimental ischemia and ischemia/reperfusion injury.

Study design

Forty-eight adult female rats were randomly divided into eight groups. In Group 1, a period of bilateral ovarian ischemia was applied. In Groups 2 and 3, 1 and 2 mg/kg of GH was administered, and 30 min later, bilateral ovarian ischemia was applied (after a 3-h period of ischemia, both ovaries were surgically removed). Group 4 received a 3-h period of ischemia followed by 3 h of reperfusion. Groups 5 and 6 received 1 and 2 mg/kg of GH, respectively, 2.5 h after the induction of ischemia. At the end of a 3-h period of ischemia, bilateral vascular clips were removed, and 3 h of reperfusion continued. Group 7 received a sham operation plus 2 mg/kg of GH. Group 8 received a sham operation only. After the experiments, superoxide dismutase and myeloperoxidase activity and levels of glutathione and lipid peroxidation were determined, and histopathological changes were examined in all rat ovarian tissue.

Results

Ischemia and ischemia/reperfusion decreased superoxide dismutase activity and glutathione levels in ovarian tissue, but increased lipid peroxidation levels and myeloperoxidase activity significantly in comparison to the sham group. The 1 and 2 mg/kg doses of GH before ischemia and ischemia/reperfusion decreased lipid peroxidation levels and myeloperoxidase activity in the experimental groups. The administration of GH before ischemia and ischemia/reperfusion treatments also increased superoxide dismutase and glutathione levels. The histopathological findings also suggested a protective role of GH in ischemia/reperfusion injury. That is, ovarian tissues in the ischemia groups showed histopathological changes, such as haemorrhage, cell degeneration, and necrotic and apoptotic cells, but these changes in the GH groups were lesser. Moreover, in the ischemia/reperfusion groups, acute inflammatory processes - such as neutrophil adhesion and migration, apoptotic and degenerative cells, stromal oedema and haemorrhage - were present. However, the ovarian tissues of the IR + GH (1 mg) group had minimal apoptotic cells, and the IR + GH (2 mg) group had no apoptotic cells. In addition, the general ovarian histological structures of these groups were similar to those of the healthy control group.

Conclusions

The administration of GH is protective against ischemia and/or ischemia/reperfusion-induced ovarian damage. This protective effect can be attributed to the antioxidant properties of GH.     

热缺血期通气对大鼠无心跳供肺的作用

目的:探讨大鼠肺移植手术中,心脏停跳后热缺血期通气对大鼠无心跳供肺的影响。方法:雄性Sprague-Dawley(SD)大鼠64只,按供体鼠体质量稍轻于受体鼠的原则,将其随机配成32对。将32对大鼠随机分为热缺血3h不通气组(warm is-chemia with non-ventilation,WNV组)和热缺血3h并机械通气3h组(warm ischemia with ventilation,WV组)2组,每组16对;每组大鼠根据再灌注时间,分为再灌注2h亚组和再灌注24h亚组,每亚组8对。建立大鼠无心跳供肺移植模型,再灌注2h或24h后对移植肺进行血气分析并处死大鼠,取其肺组织,检测肺湿干质量比、肺损伤病理评分、细胞凋亡等指标并在电镜下观察细胞超微结构。结果:左肺静脉的氧分压(PaO2)在WNV组和WV组的2个再灌注2h亚组之间以及2个再灌注24h亚组之间均有显著差异(P<0.05),右颈动脉PaO2仅在2个再灌注24h亚组之间有显著差异(P<0.05);左肺湿干质量比和光镜形态学病理损伤评分在2个再灌注24h亚组之间均有显著差异(P<0.05);细胞凋亡指数在2个再灌注2h亚组之间有显著差异(P<0.05);电镜观察显示WV组细胞超微结构的损伤较WNV组轻。结论:热缺血期通气能够改善大鼠无心跳供肺移植缺血再灌注肺损伤,提示无心跳供肺热缺血时间在低温且肝素化通气状况下可达3h。     

Effect of remifentanil on toll-like receptor 4, NF-κB and IL-6 in rabbit myocardial ischemia/reperfusion model

Objective:To investigate whether remifentanil induced cardioprotecting effect is associated with expression of toll-like receptor 4 (TLR4).nuclear factor κB (NF-κB) and serum interleukin -6 (IL-6).Meth...     

外周血干细胞移植对动物肢体局部化脓性感染的影响

目的:探讨自体外周血干细胞移植对动物下肢动脉缺血组织手术切口的局部抗化脓性感染效果。方法:对正常动物和糖尿病模型动物分别进行外周血干细胞动员,然后经手术形成下肢动脉缺血模型后分别进行干细胞移植的分组观察。2周内观察动物手术后切口出现的化脓性感染情况。结果:只进行外周血干细胞动员的动物,手术后右下肢局部发生化脓性感染率比较高;而外周血干细胞动员后再进行外周血干细胞移植的动物,感染率明显下降(P<0.05)。糖尿病模型实验动物的这种感染率更高,在不使用抗菌素的情况下,手术后右下肢大多出现了感染(P<0.05)。结论:外周血干细胞移植可明显提高动物缺血肢体的局部抗化脓性感染能力,而对于糖尿病动物,这种抗感染能力则会明显下降。     

参芎葡萄糖注射液对脑缺血再灌注损伤保护作用的研究进展

脑缺血再灌注损伤主要与炎症反应、自由基过度形成、兴奋性氨基酸毒性作用及细胞内钙超载等多种机制相关.单体复方中药制剂参芎葡萄糖注射液可抑制脑缺血再灌注损伤,现将其作用机制综述如下.     

缺血和缺氧诱导离体SD乳鼠心肌细胞凋亡发生的实验研究

目的：通过建立一种新的离体SD乳鼠心肌细胞的缺氧模型,探讨心肌细胞缺氧、缺血损伤后的心肌细胞凋亡及其时序分布特点。方法：SD乳鼠的培养心肌细胞随机分为5组：对照组,缺氧12h组（I12h）、缺氧24h组（I24h）,缺氧48h组（I48h）以及缺氧72h组（172h）。应用TUNEL法染色和透射电镜检测心肌细胞凋亡的改变。结果：I12h组心肌细胞中见少量的TUNEL阳性细胞,随缺氧时间的延长,TUNEL阳性细胞数量逐渐增多。I12h组的心肌细胞凋亡指数（AI）与对照组相比差异有统计学意义（P〈0．01）,I48h组、I22h组心肌细胞的AI值分别可达（24．4±2．41）％和（45．4±4．22）％。透射电镜观察各分析时相点心肌细胞,凋亡心肌细胞在I24h组出现,L48h组、I72h组最多见。结论：乳鼠心肌细胞缺氧模型可导致心肌细胞凋亡,凋亡程度和心肌细胞缺氧时间有关。细胞凋亡在心肌缺血、缺氧心肌细胞死亡中起重要作用。     

Erythropoietin facilitates the return of spontaneous circulation and survival in victims of out-of-hospital cardiac arrest

Background

Erythropoietin activates potent protective mechanisms in non-hematopoietic tissues including the myocardium. In a rat model of ventricular fibrillation, erythropoietin preserved myocardial compliance enabling hemodynamically more effective CPR.

Objective

To investigate whether intravenous erythropoietin given within 2 min of physician-led CPR improves outcome from out-of-hospital cardiac arrest.

Methods

Erythropoietin (90,000 IU of beta-epoetin, n = 24) was compared prospectively with 0.9% NaCl (concurrent controls = 30) and retrospectively with a preceding group treated with similar protocol (matched controls = 48).

Results

Compared with concurrent controls, the erythropoietin group had higher rates of ICU admission (92% vs 50%, p = 0.004), return of spontaneous circulation (ROSC) (92% vs 53%, p = 0.006), 24-h survival (83% vs 47%, p = 0.008), and hospital survival (54% vs 20%, p = 0.011). However, after adjusting for pretreatment covariates only ICU admission and ROSC remained statistically significant. Compared with matched controls, the erythropoietin group had higher rates of ICU admission (92% vs 65%, p = 0.024) and 24-h survival (83% vs 52%, p = 0.014) with statistically insignificant higher ROSC (92% vs 71%, p = 0.060) and hospital survival (54% vs 31%, p = 0.063). However, after adjusting for pretreatment covariates all four outcomes were statistically significant. End-tidal PCO₂ (an estimate of blood flow during chest compression) was higher in the erythropoietin group.

Conclusions

Erythropoietin given during CPR facilitates ROSC, ICU admission, 24-h survival, and hospital survival. This effect was consistent with myocardial protection leading to hemodynamically more effective CPR (Trial registration: http://isrctn.org. Identifier: ISRCTN67856342).     

Radiologic findings in taxane induced colitis

Ischemic colitis in breast cancer patients being treated with taxane-based chemotherapy, which may lead to serious morbidities and even death, has recently been defined as a clinical entity. The purpose of this retrospective study was to evaluate the computed tomography (CT) findings in taxane-related colitis and determine their clinical relevance. CT scans of 41 patients at risk for taxane colitis were reviewed retrospectively for bowel and peritoneal abnormalities. Morphological findings were analyzed and correlated with clinical, pathological, and endoscopic findings. CT scans in 10 of the 41 patients showed a definitely abnormal colon with a thickened wall or distended with fluid, signs that are suggestive of colitis, in the context of the clinical picture. Radiographic changes in patients with taxane colitis are not specific but, in the appropriate context, can suggest the correct diagnosis and guide the patient's management.     

Mechanical stimulation improves survival in random-pattern skin flaps in rats

This was a study on the effects of 3-MHz ultrasound at 16- and 100-Hz pulse repetition frequencies on angiogenesis and viability of random-pattern skin flaps in rats. A cranially-based dorsal skin flap was raised in 60 EPM-Wistar rats, which were randomly divided into four groups: control, sham, 16-Hz and 100-Hz groups. The mean percentage of necrosis was as follows: control, 42% ± 13%; sham, 18% ± 13%; 16-Hz group, 13% ± 10%; and 100-Hz group, 15% ± 7%, with significant differences between the control and the other groups (p < 0.001). The mean vascular density was as follows: control, 5% ± 2%; sham, 7% ± 2%; 16-Hz group, 21% ± 4%; and 100-Hz group, 24% ± 10%, with significant differences between control and ultrasound groups, and between the sham and ultrasound groups (p < 0.001). Both ultrasound treatments (16- and 100-Hz PRFs) induced angiogenesis, and sham and ultrasound treatments improved viability of random-pattern skin flaps in rats.