Expression of inducible nitric oxide synthase in muscle flaps treated with ischemic postconditioning

Background/Objective

Preconditioning has been considered promising for the treatment of ischemic flaps. In this study, the therapeutic effect of postconditioning was compared with that of preconditioning during ischemia/reperfusion (I/R) injury, and a role of inducible nitric oxide synthase (iNOS) in postconditioning treatment was also explored.

Methods

Sixty rats were randomly divided into four groups with 15 rats in each group. Ischemic injury was induced in a rat’s gracilis muscle flap model. Preconditioning and postconditioning were performed respectively on the flaps in the pre-con group and the post-con group. No treatment was given to the flaps in the control group, and flaps without I/R injury were used as a sham control. Muscle viability ratio, histology, and gene expression of iNOS were examined at different time intervals (3, 12, and 18 h).

Results

A significantly higher survival ratio was observed in both the pre-con group (78.98 ± 3.39, 62.74 ± 3.7, and 54.42 ± 4.45 %) and the post-con group (77.42 ± 4.14, 59.74 ± 6.67, and 49.52 ± 4.13 %) than the control group (45.22 ± 3.69, 42.44 ± 3.76, and 33.2 ± 3.29 %) at 3, 12, and 18 h postoperatively (P < 0.05). There was no statistical difference between the pre-con group and the post-con group (P > 0.05). Histological examination showed delayed and attenuated tissue damage in both the pre-con group and the post-con group when compared to that of the control group. A higher expression of iNOS was observed in both the pre-con group and the post-con group than the control group and the sham group (P < 0.05).

Conclusions

Significant improvement of flap survival could be achieved by both preconditioning and postconditioning treatments; however, better protection could be provided by preconditioning. The higher expression of iNOS may play an important role in the therapeutic effect of postconditioning during I/R injury.     

The effect of vascular endothelial growth factor on the healing of ischaemic skin wounds.

The effect of exogenous vascular endothelium growth factor (VEGF) on wound healing in an ischaemic skin flap model was evaluated in this study. Seventy-two Sprague-Dawley rats were used. Normal incisional wound and H-shaped double flaps were used as the wound models. The study was divided into two parts. In Part I, VEGF protein levels were determined from the incisional and H-shaped ischaemic wounds at 12 and 24 h, postoperatively. In Part II, tensile strength and immunohistochemical stains were examined to determine the level of microvessel density (MVD) at 1 and 2 weeks, postoperatively in simple incisional wounds, ischaemic wounds, and ischaemic wounds following 1 ml (1 microg/ml) exogenous VEGF injections into the subcutaneous tissue. The results showed a significantly higher level of VEGF protein in the ischaemic wounds than the incisional wounds. Tensile strength was statistically higher in the incisional wound group and in the ischaemic flap wounds with VEGF treatment compared to the ischaemic flaps with no treatment at 1 week, postoperatively (p>0.05). MVD data indicated that ischaemic wound repair with VEGF treatment had significantly higher MVD than the normal incisional wounds and ischaemic wounds without treatment. We conclude that exogenous application of VEGF can increase early angiogenesis and tensile strength in the ischaemic wound.     

腹腔镜治疗急性胆囊炎145例分析

目的 评价腹腔镜胆囊切除术(LC)治疗急性胆囊炎的安全性及可行性。方法回顾分析1994年～2000年LC治疗急性胆囊炎145例。结果本组急诊行LC，手术时间：30min～130min，平均68min。术后并发症5例，2例为胆囊动脉出血，均再次腹腔镜下止血成功；1例胆漏，1例大网膜损伤出血，再次开腹手术完成；1例肝下脓肿，经抗炎治疗痊愈。一次手术成功率96．6％(140／145)。结论急性胆囊炎发作1天～3天内，B超提示胆囊壁厚≤5mm，急诊胆囊切除术能在腹腔镜下完成。     

椎间融合器治疗Ⅰ～Ⅱ度腰椎滑脱症

目的 观察Cage椎间融合器治疗Ⅰ～Ⅱ度腰椎滑脱症的近期疗效。方法 应用Cage椎间融合器治疗Ⅰ～Ⅱ度腰椎滑脱症41例，按Meyerding分度，Ⅰ度滑脱25例，Ⅱ度滑脱16例。经前路31例，经后路10例。仅置入1个Cage6例，其中前路4例，后路2例；其余均置入2个Cage。结果 手术前后X线片测量，见病椎有69％～100％(平均83％)的复位，其中15例完全复位。其中32例术后获得10～36个月、平均17个月随访，全部骨性融合，26例症状完全消失，优良率为81．3％。结论 Ⅰ～Ⅱ度的腰椎滑脱症均可应用Cage椎间融合器治疗。     

Emergency coronary artery bypass surgery in the era of glycoprotein IIb/IIIa receptor antagonist use

The use of intravenous glycoprotein (GP) IIb/IIIa platelet receptor antagonists in the management of patients with acute coronary syndrome or those undergoing percutaneous coronary intervention (PCI) has become increasingly common in recent years. There are three GP IIb/IIIa receptor antagonists currently available for clinical use. Patients on GP IIb/IIIa receptor antagonists who require emergency surgical revascularization may be at increased risk for excessive peri- and postoperative bleeding. The duration of action of eptifibatide and tirofiban are short because they bind reversibly to the GP IIb/IIIa receptor and have a short half-life. Therefore, within a relatively short time after discontinuation of these agents, surgery can be performed with little or no increased risk of bleeding and without the need for additional hemostatic measures. Abciximab has a short plasma half-life but a long duration of action due to its high-affinity binding of GP IIb/IIIa receptors. Early retrospective studies demonstrated a higher incidence of major bleeding and requirement for blood transfusion, especially in those undergoing surgery within 12 hours of the discontinuation of abciximab. However, platelet transfusion has been shown to successfully reduce the incidence of these complications. The current evidence therefore indicates that, with appropriate measures, urgent surgical revascularization can be safely performed in patients who have received a GP IIb/IIIa receptor antagonist with little added risk. The benefits of these agents in the treatment of patients with an acute coronary syndrome or undergoing PCI are not obviated by the need for emergency bypass surgery.     

Is Patient-Specific Instrumentation Accurate and Necessary for Open-Wedge High Tibial Osteotomy? A Meta-Analysis

The purpose of this meta-analysis was to identify if patient-specific instrumentation (PSI) could increase the accuracy of the correction in high tibial osteotomy (HTO) and to explore the assessment indices and the necessity of using a PSI in HTO. A systematic search was carried out using online databases. A total of 466 patients were included in 11 papers that matched the inclusion criteria. To evaluate the accuracy of PSI-assisted HTO, the weight bearing line ratio (WBL%), hip-knee-ankle angle (HKA), mechanical medial proximal tibial angle (mMPTA), and posterior tibial slope angle (PTSA) were measured preoperatively and postoperatively and compared to the designed target values. Statistical analysis was performed after strict data extraction with Review Manager (version 5.4). Significant differences were detected in WBL% (MD = −36.41; 95% CI: −42.30 to −30.53; p < 0.00001), HKA (MD = −9.95; 95% CI: –11.65 to –8.25; p < 0.00001), and mMPTA (MD = –8.40; 95% CI:−10.27 to −6.53; p < 0.00001) but not in PTSA (MD = 0.34; 95% CI: −0.59 to 1.27; p = 0.47) between preoperative and postoperative measurements. There was no significant difference between the designed target values and the postoperative correction values of HKA (MD = 0.14; 95% CI: −0.19 to 0.47; p = 0.41) or mMPTA (MD = 0.11; 95% CI −0.34 to 0.55; p = 0.64). The data show that 3D-based planning of PSI for HTO is both accurate and safe. WBL%, HKA, and mMPTA were the optimal evaluation indicators of coronal plane correction. Sagittal correction is best evaluated by the PTSA. The present study reports that PSI is accurate but not necessary in typical HTO.     

A new experimental inbred Wistar rat varicocele model: anatomy of the left spermatic vein and the effect on histology

Because of venous anatomical differences between rats and humans and the personal interpretation of these differences, there is neither consistent animal prototype nor consistent results in the study of varicocele. We established a new substrain of Wistar inbred rats, of which the left testis vein has no significant branches to the common iliac vein up pampiniform plexus, but instead enters the left renal vein directly (similar to humans) and used them to create experimental varicocele model by partial ligation of the left renal vein. One month later, the predominant lesion of the left testis in induced group was spermatogenic arrest at the spermatid and preliminary spermatocyte phases, and considerable interstitial and Sertoli cell vacuolation. The right testis also showed spermatogenic arrest. Most important, the characteristics of the lesions differed in both testes, with the left testis having more severe lesions. Allowing for the unique anatomy of the left spermatic vein, the standard of the surgical procedure, the high rate of varicocele induction, and identical histological alteration as occurs in humans, we believe that this inbred Wistar rat substrain is suitable for the creation of an experimental varicocele model, which has promise for practical application in humans.