大鼠骨髓基质干细胞在成骨诱导剂条件下的成骨能力

目的:观察在有成骨诱导剂存在的条件下,大鼠骨髓基质干细胞向成骨细胞转化的能力。方法:实验于2005-07/12在锦州医学院中心实验室完成。选取清洁级2月龄SD大鼠6只,无菌条件下取双侧股骨,制备单细胞悬液。采用贴壁培养与传代结合方法分离纯化大鼠骨髓基质干细胞,将2代细胞置于含有1×10-7mol/L地塞米松、10mol/Lβ-甘油磷酸钠、50mg/L抗坏血酸成骨诱导剂的培养基中,培养21～30d。应用倒置显微镜观察骨髓基质干细胞与诱导后细胞形态,描绘生长曲线,流式细胞仪检测细胞周期,并用碱性磷酸酶染色和VON-KOSSA法检测成骨能力。结果:6只大鼠均进入结果分析。①骨髓基质干细胞形态学观察结果:在成骨诱导剂里细胞增殖变缓慢,呈长梭形、成纤维细胞样或不规则形。②细胞生长曲线:1～2d为潜伏期,细胞增殖不明显;3d后细胞增殖明显加快,进入对数生长期;6d后增殖变慢为平台期。经计算细胞群体倍增时间为38h。③细胞增殖周期检测结果:G0/G1期为(82.12±4.60)%,S期为(14.35±2.32)%,G2/M期为(0.87±0.30)%。④成骨能力检测结果:细胞碱性磷酸酶染色阳性率为86%,VON-KOSSA染色提示有钙结节形成。结论:大鼠骨髓基质干细胞在有成骨诱导剂存在的情况下成骨能力较高。     

Adenovirus-mediated GM-CSF gene and cytosine deaminase gene transfer followed by 5-fluorocytosine administration elicit more potent antitumor response in tumor-bearing mice.

Antitumor effects of combined transfer of suicide and cytokine genes were investigated in this study. Adenovirus harboring E. coli cytosine deaminase gene (AdCD) and adenovirus harboring murine granulocyte-macrophage colony-stimulating factor gene (AdGMCSF) were used simultaneously for in vivo gene transfer in melanoma-bearing mice. Growth inhibition of established tumors and prolongation of survival period were observed more significantly in tumor-bearing mice after transfection with AdGMCSF and AdCD followed by continuous injection of prodrug 5-fluorocytosine (5FC) when compared with mice treated with control adenovirus AdlacZ/5FC, AdCD/5FC or AdGMCSF alone (P < 0.01). After combined therapy the expression of MHC-I (H-2Db) and B7-1 molecules on freshly isolated tumor cells increased greatly and more dendritic cells and CD8+ T cells infiltrated into the tumor mass. The activity of specific cytotoxic T lymphocytes was also found to be induced more significantly after the combined therapy. Further experiments showed that apoptosis of tumor cells and induction of antitumor immune response might be involved in the mechanisms of the tumor cell killing by the combined therapy. Our results demonstrated that combined transfer of the GM-CSF and CD suicide genes, being able to inhibit the growth of melanoma synergistically and induce specific antitumor immune response efficiently, thus addressing the drawbacks of suicide gene therapy or cytokine gene therapy which were proved to be not satisfactory when used alone, might be of therapeutic potential for gene therapy of cancer.     

Experimental study of bone marrow-derived mesenchymal stem cells combined with hepatocyte growth factor transplantation via noninfarct-relative artery in acute myocardial infarction

We investigated the impact of bone marrow-derived mesenchymal stem cells (BM-MSCs) alone or in combination with hepatocyte growth factor (HGF) transplantation via noninfarct-relative artery in a swine myocardial infarction (MI) model. Donor BM-MSCs were derived in vitro from swine auto-bone marrow cultures labeled by bromodeoxyuridine (BrdU) incorporation. Host MI swine model was created by ligating the distal left anterior descending artery. After 4 weeks, age-matched male MI swines were used for the transplantation. Male MI swines were transfused via noninfarct-relative artery with vehicle (control, n=6) or BrdU-labeled BM-MSCs (5 x 10(6)) alone (MSCs, n=6) or BrdU-labeled BM-MSCs (5 x 10(6)) combined with HGF (4 x 10(9) PFU) (MSCs+HGF, n=6). To evaluate the collateral artery growth (Rentrop) and cardiac perfusion in these animals, gate cardiac perfusion imaging and coronary angiography were performed before and 4 weeks after transplantation, respectively. To assess the contribution of donor-originated cells in stimulation of cardiomyocyte regeneration and angiogenesis, immunohistochemistry for BrdU and alpha-smooth muscle actin (alpha-SMA) and quantitative image analysis were performed at 4 weeks after transplantation. The results are as follows: (1) BrdU-positive cells were detected in host myocardium in both MSCs and MSCs+HGF groups, but not in the vehicle group. Most BrdU-positive cells expressed myosin heavy chain beta. (2) alpha-SMA(-)positive arteriole densities in the infarcted border area and infarcted area were increased significantly in both transplantation groups compared with the vehicle group. (3) Gate cardiac perfusion imaging demonstrated that the cardiac perfusion was significantly improved in transplantation groups compared with the vehicle group. (4) Ejection fraction and alpha-SMA-positive arteriole densities were increased significantly in both transplantation groups compared with the vehicle group. However, there was no difference in ejection fraction and alpha-SMA-positive arteriole densities between the MSCs group and the MSCs+HGF group. Growth of collateral arteries was not detected by coronary angiography in all three groups. In conclusion, the current study indicates that BM-MSCs transplantation via noninfarct-relative artery stimulates cardiomyocyte regeneration and angiogenesis and improves cardiac function, but does not stimulate collateral artery growth. BM-MSCs transplantation combined with HGF therapy is not superior to BM-MSCs alone transplantation. BM-MSCs transplantation via noninfarct-relative artery may be an alternative for those patients who cannot be transplanted via infarct-relative artery in clinical practice.     

THE CHANGING INDICATIONS FOR CAROTID ENDARTERECTOMY IN THE UK

In early series the majority of carotid endarterectomies were performed in patients with amaurosis fugax (AFx) or transient ischaemic attacks (TIAs) who were thought to have atheromatous ulcers of the carotid bifurcation or the internal carotid artery (ICA). The degree of stenosis was considered to be of secondary importance. We compared our own data with two British series undertaken in the early and late 80s/early 90s. This reflects the broadening of indications and the change of practice for carotid endarterectomy over the years, on the one hand towards including patients who are at greater risk of perioperative stroke (previous CVAs vs TIAs, crescendo TIAs and stroke in evolution), and on the other towards patients who have had no symptoms attributable to the carotid lesion (asymptomatic cases, combined carotid and cardiac procedures).     

生理盐水灌肠治疗骨科下肢手术术后尿潴留的临床观察

[目的]探讨生理盐水灌肠用于解除骨科下肢手术后尿潴留的效果.[方法]随机选择72例骨科下肢手术术后尿潴留病人,利用随机数字表分为两组,各36例.观察组用生理盐水灌肠,对照组用传统诱导法.排除下尿路梗阻、语言障碍、泌尿系统疾病病人.[结果]观察组有效率94.4%,对照组有效率72.2%,两组比较差异有统计学意义(P＜0.01);两组首次排尿时间比较,差异有统计学意义(P＜0.01).[结论]生理盐水灌肠用于解除骨科下肢手术术后尿潴留效果满意.     

Contrast-enhanced ultrasonic parametric perfusion imaging in the evaluation of antiangiogenic tumor treatment

Purpose

To assess the validity of contrast-enhanced ultrasonic parametric perfusion imaging in the evaluation of antiangiogenic tumor treatment by using histology as the reference standard.

Materials and methods

H22 hepatoma-bearing mice were treated with thalidomide or placebo by intraperitoneal injection. Contrast-enhanced ultrasound was performed on day 8 after bolus injection of SonoVue. Three different parametric perfusion images were calculated based on the following parameters: area under the curve (AUC), maximum intensity (IMAX) and perfusion index (PI). A score from 1 to 5 (1 = low, 5 = excellent) was used for analysis of parametric perfusion images by two independent readers. Immunohistochemical analysis was performed for evaluation of microvascular density (MVD).

Results

Treatment with thalidomide resulted in a significant decrease in perfusion scores assigned to AUC, IMAX and PI parametric images as compared with control tumors (P < 0.001). Immunohistochemistry showed significant decreases of MVD in treated tumors as compared with control tumors (P = 0.002). MVD was positively correlated with the perfusion scores assigned to AUC parametric images (r = 0.568, P = 0.009), IMAX parametric images (r = 0.614, P = 0.004) and PI parametric images (r = 0.636, P = 0.003).

Conclusion

Contrast-enhanced ultrasonic parametric perfusion imaging provides a noninvasive tool to directly visualize tumor perfusion changes after antiangiogenic tumor treatment.     

不同体位干预对第三脑室肿瘤手术病人的影响

第三脑室的肿瘤手术一般需要采用枕部小脑幕入路，由于手术时间长．操作空间狭小，对手术体位的摆放要求甚高。既要充分暴露视野便于医生的手术操作．又要保护病人的神经、呼吸、循环等系统的重要生理功能，还要有利于麻醉师观察病人，避免病人神经、血管及各部位肌肉的损伤。     

Tumor-specific gene expression using the survivin promoter is further increased by hypoxia

Increasing evidence indicates that survivin, an inhibitor of apoptosis protein (IAP), is expressed in human cancer cells but is absent from most normal adult tissues. Here, we examined the feasibility of using a survivin promoter (Sur-P) to direct therapeutic expression of a proapoptotic gene specifically in human tumor cells. First, we demonstrated that this promoter was highly active in human tumor cells but not in normal cells. Second, we found that Sur-P activity was upregulated by hypoxia in tumor cells. Third, to further enhance this promoter's activity under hypoxia, we added a hypoxia-responsive element (HRE) from the vascular endothelial growth factor gene promoter in its 5' region, and showed that this combination resulted in a further increase in the level of gene expression in hypoxic tumor cells. Finally, we demonstrated that expression of an autocatalytic reverse caspase-3 gene by this promoter specifically induced apoptotic cell death in human tumor cells but not in normal cells. These findings support the use of promoters Sur-P or chimeric HRE-Sur-P for generating novel vectors for cancer gene therapy.     

Short-term Rosuvastatin Treatment for the Prevention of Contrast-induced Acute Kidney Injury in Patients Receiving Moderate or High Volumes of Contrast Media: A Sub-analysis of the TRACK-D Study

Background:

Current randomized trials have demonstrated the effects of short-term rosuvastatin therapy in preventing contrast-induced acute kidney injury (CIAKI). However, the consistency of these effects on patients administered different volumes of contrast media is unknown.

Methods:

In the TRACK-D trial, 2998 patients with type 2 diabetes and concomitant chronic kidney disease (CKD) who underwent coronary/peripheral arterial angiography with or without percutaneous intervention were randomized to short-term (2 days before and 3 days after procedure) rosuvastatin therapy or standard-of-care. This prespecified analysis compared the effects of rosuvastatin versus standard therapy in patients exposed to (moderate contrast volume [MCV], 200–300 ml, n = 712) or (high contrast volume [HCV], ≥300 ml, n = 220). The primary outcome was the incidence of CIAKI. The secondary outcome was a composite of death, dialysis/hemofiltration or worsened heart failure at 30 days.

Results:

Rosuvastatin treatment was associated with a significant reduction in CIAKI compared with the controls (2.1% vs. 4.4%, P = 0.050) in the overall cohort and in patients with MCV (1.7% vs. 4.5%, P = 0.029), whereas no benefit was observed in patients with HCV (3.4% vs. 3.9%, P = 0.834). The incidence of secondary outcomes was significantly lower in the rosuvastatin group compared with control group (2.7% vs. 5.3%, P = 0.049) in the overall cohort, but it was similar between the patients with MCV (2.0% vs. 4.2%, P = 0.081) or HCV (5.1% vs. 8.8%, P = 0.273).

Conclusions:

Periprocedural short-term rosuvastatin treatment is effective in reducing CIAKI and adverse clinical events for patients with diabetes and CKD after their exposure to a moderate volume of contrast medium.