The cultivation of clinical medical postgraduates is a way to provide qualified doctors for clinical practice, which is more focused on clinical practice. The cultivation of clinical medical postgraduates depends on their understanding of knowledge. In response to the problems existing in traditional education, the Department of Vascular Surgery, Xuanwu Hospital, Capital Medical University has introduced new media into the cultivation of clinical medical postgraduates. New media can concretize abstract content, which is more conducive to improve learning efficiency. This article combines practical experience to explain the advantages, teaching effectiveness, challenges faced of new media, and how to better apply new media teaching.
Objective To induce embryonic stem cell (ESC) to differentiate into endothel ioid cells using a simple adhesive culture method, and to provide a new cells seed source for vascular tissue engineering or cell therapy. Methods SV129-derived ESC were seeded at 2 × 104/cm2 and maintained undifferentiated on ESC culture medium in the presence of 1 000 U/mL leukaemia inhibitory factor (LIF). Embryoid body (EB) formatted when ESC cultured in suspension in the lack of LIF. At 4 days, EB was transferred to 0.1% gelatin coated dish and cultured with medium supplementary of VEGFto be induced differentiation. The characteristics of differentiated cells were determined by immunohistochemistry staining, flow cytometry (FCM), 1, 1-dioctadecyl-3, 3, 3, 3-tetramethyl indocarbocyanine-labeled acetylated low density l ipoprotein (DiIAc- LDL) takeup test, and TEM detection. Results Differentiated cells were morphologically characterized as endothel ial cells. They could takeup DiI-Ac-LDL, be stained positive by Flk-1 and CD31. The CD31 positive cells reached above 90% when measured by FCM. Furthermore, Weibel-Palade bodies were detected and tight junctions were found when differentiated cells were examined by TEM. Conclusion Using a simple adhesive culture method and by suppl ied with VEGF alone, ESCs can be induced to differentiate into endothel ioid cells. The differentiation method is simple and economic, and can provide seed cells for vascular tissue engineering or cell-therapy.
Objective To observe the changes in the number and function of bone marrow-derived endothel ial progenitor cells (EPCs) after bone-marrow stimulation, and to investigate the possible mechanism of improving ischemicl imb disease after bone-marrow stimulation through autologue bone-marrow stem cell implantation. Methods Twelvemale Lewis rats, weighing 200-250 g, were classified into the bone marrow stimulation group (n=6) and the control group(n=6). In the stimulation group, the bone marrow of each rat was stimulated by injection of recombinant human granulocytemacrophage colony-stimulatory factor. Mononuclear cells were harvested from bone marrow and cultured in EBM-2 medium. After 7-day culture, EPCs were stained by 1, 1-dioctadecyl-3, 3, 3, 3-tetramethyl indocarbocyanine-labbled acetylated low density l ipoprotein/fluorescein isothiocyanate-ulex europaeus agglutinin 1, and the double positive cells were counted by the fluorescent microscope. The adhesive abil ity of EPCs was determined by counting the number of re-cultured EPCs. The unilateral ischemia hindl imb model was made with 12 Lewis rats. Three days later, EPCs were transplanted into the ischemic tissues. According to different sources of EPCs, the 12 rats were divided into 2 groups: the stimulation group (n=6) and the control group (n=6). At 3 weeks after EPCs transplantation, the quantity of the collateral vascular was observed by digital subtraction angiography (DSA). Results After 7-day culture, the number of EPCs in the stimulation and control groups was (145.2 ± 37.0)/HP and (95.2 ± 39.4)/HP, respectively, and there was significant difference between the two groups (P lt; 0.05). Meanwhile, the number of adhesive EPCs in the stimulation and control groups was (21.8 ± 4.3)/HP and (15.0 ± 5.2)/HP, respectively, and the difference between the two groups was significant (P lt; 0.05). At 3 weeks after the EPCs implantation, the number of the collateral vascular was significantly larger in the stimulation group (4.2 ± 1.2) compared with the control group (2.7 ± 0.8), (P lt; 0.05). Conclusion Bone marrow stimulation increases the number of EPCs and improves the function concurrently, which may be the reason why autologue bone-marrow stem cell implantation improves the curative effect of ischemic l imb diseases after bone-marrow stimulation.
ObjectiveTo summarize the feasibility and effectiveness of endovascular treatment for vertebral artery stenosis ectopic originating from the aortic arch. MethodThe clinical data of 5 patients with vertebral artery stenosis ectopic originating from aortic arch admitted to Xuanwu Hospital of Capital Medical University from January 2020 to May 2023 were retrospectively analyzed. ResultsAll 5 patients underwent magnetic resonance angiography and CT angiography before operation. The vertebral arteries of all patients originated from the aortic arch and were severe stenosis, with a median diameter of 1.3 mm (range, 1.1–1.5 mm). All 5 patients were successfully treated with endovascular intervention. The operation time was 37–45 min, with a median of 39 min. There were no complications of vertebral artery rupture, embolism or occlusion, cerebral infarction, plaque abscission, hematoma at puncture site, pseudoaneurysm, postoperative hemorrhage, or perioperative pulmonary infection. The patients were followed-up for 13–30 months, with a median follow-up time of 20 months. The blood vessels of 5 patients remained unobstructed and no clinically significant vascular restenosis occurred. ConclusionsBased on the experiences of 5 cases of vertebral artery stenosis ectopic originating from the aortic arch, it is safe and effective to choose endovascular treatment for severe symptomatic vertebral artery stenosis. Especially, it is necessary use CT angiography to evaluate the stenosis degree of vertebral artery before operation.
Objective To establish chronic hindlimb ischemia model with suture-occluded method in rats， and then compare the effects of chronic hindlimb ischemia model with acute ischemia model. Methods Models of chronic hindlimb ischemia were established by using suture-occluded femoral artery method. The laser Doppler blood flow analysis and angiography were performed on day 7， 14， 28， 42， and 49 after operation， and then the rats were sacrificed after angiography， respectively， the quadriceps and gastrocnemius of contralateral and ipsilateral （surgical side） were gotten， which were tested by HE staining and α-actin immunohistochemistry staining， and then calculate arteriolar density. Results There were no lameness and limb necrosis after operation in chronic hindlimb ischemia models. Laser Doppler analysis found that chronic hindlimb ischemia models were still maintained in ischemia state on day 49 after operation compared with acute ischemic models. The resluts of HE staining showed no acute necrosis and muscle fibrosis in chronic hindlimb ischemia model group. Chronic hindlimb ischemia models after operation did not appear obvious lameness and limb necrosis. The arteriolar density of quadriceps femoris on day 7 after operation in chronic hindlimb ischemia models were less than that in acute hindlimb ischemia models （0.015 2 vs. 0.036 4）. Conclusions Compared with the commonly used acute ischemic models， the duration of arterial limb ischemia in chronic hindlimb ischemia rats， which were established by suture-occluded method， is longer and less likely to be affected by the compensatory mechanisms. So suture-occluded method can provide a new animal hindlimb ischemia model for further study of ischemia angiogenesis mechanism and treatment of severe lower extremity ischemia.
Objective To explore the mechanism of mesenchymal stem cells （MSCs） transplantation for chronic hindlimb ischemia in Lewis rats by using cell tracer technique. Methods MSCs were isolated and cultured by using density gradient centrifugation and adherence method respectively， then labeled by 5-bromo-2-deoxyuridine （BrdU）. Eight chronic hindlimb ischemia models of Lewis rats were prepared by using suture-occluded method and then divided randomly to MSCs transplantation group and control group， each group enrolled 4 rats， accepting MSCs transplantation and saline respectively. Then on 7 days and 14 days after transplantation， clinical observation， determination of blood flow， and angiography were performed on rats of the 2 groups. At the same time points after previous tests， rats of the 2 groups were sacrificed to get quadriceps tissues and gastrocnemius tissues to perform HE staining and BrdU immunohis-tochemistry. Results The 8 rats were all survived on 14 days after transplantation， with no tumor happened and necroses in the transplanted area. On 14 days after transplantation， the blood flow ratio of operated side to un-operated side in the hindlimb （1.773 vs. 1.279） of rats in MSCs transplantation group and control group increased， and the angiography results showed that there were no much increase in ratio of collateral vessels number （0.908 vs. 0.835）. There were no significant change in the quadriceps tissues and gastrocnemius tissues by HE staining. The BrdU positive kernels located in the inter-stitial substance cells and vascular endothelia cells， and divided differently in different parts of hindlimb at different time points， that the ratio of positive cells in gastrocnemius tissue was higher than those of quadriceps tissue on 7 days after transplantation， but lower on 14 days. Conclusions MSCs transplantation can increases the blood perfusion of hindlimb in the early stage of chronic hindlimb ischemia model， and the possible mechanism may be the paracrine effect of MSCs but not the number increase of collateral vessels.
ObjectiveTo evaluate the dynamic changes of blood flow and blood pressure of acute hindlimb ischemia of rats by laser Doppler flowmetry (LDF) and laser Doppler perfusion imaging (LDPI). MethodsThe acute hindlimb ischemia model of rats was established by resection of rats femoral arteries of left hindlimb. The blood flow and blood pressure between operated and nonoperated hindlimbs were examined by LDF on 2, 7, 14, 28, and 49 d after operation. And the blood flow was evaluated by LDPI on 7 d after operation. ResultsAll rats survived after operation and no hindlimb necrosis occurred. The mean score was 2 on 14 d after operation and 1 on 49 d after operation. The ratio of blood flow between operated and nonoperated hindlimbs on 2 d after operation significantly increased from 1 to 1.31±0.439 (P=0.021). The ratio of blood flow on 7 d (0.82±0.538) and 14 d (0.93±0.294) after operation was significantly lower than that on 2 d after operation (P=0.032 and P=0.019), although the difference between the two former was not significant (P=0.502). Furthermore, the ratio of blood flow on 28 d after operation reached the bottom (0.41±1.970), which was obviously lower than that on 2, 7, and 14 d after operation (P=0.004, P=0.007, and P=0.006). The blood flow of operated hindlimbs recovered approximately the value before operation (0.98±0.093), which was significantly lower than that on 2 d (P=0.010), higher than that on 28 d (P=0.005), but not different from that on 7 d and 14 d after operation (P=0.126 and P=0.382). The ratio of blood pressure between operated and nonoperated hindlimbs on 2 d after operation significantly increased from 1 to 0.47±0.375 (P=0.031). The ratio of blood pressure decreased on 7 d after operation (0.44±0.118), which was not different from that on 2 d after operation (P=0.203). Furthermore, the ratio of blood pressure on 14 d after operation reached the bottom (0.35±0.115), which was obviously lower than that on 2 d and 7 d after operation (P=0.001 and P=0.036). On 28 d after operation, the ratio of blood pressure increased (0.54±0.146), which was significantly higher than that on 14 d after operation (P=0.008), while not different from that on 2 d (P=0.493) and 7 d after operation (P=0.551). The ratio of blood pressure recovered approximately the value before operation (0.97±0.094), which was significantly higher than that on 2, 7, 14, and 28 d (P=0.013, P=0.021, P=0.002, and P=0.031). ConclusionAcute hindlimb ischemia model of rats can be established by resection of rats femoral arteries of left hindlimb and the most serious stage of hindlimb ischemia is on 14-28 d after operation. LDF and LDPI are of importance for monitoring the dynamic changes of rats hindlimb ischemia after operation.
Objective To investigate the influencing factors for restenosis after femoral endarterectomy in treatment of arteriosclerosis obliterans at femoral artery . Methods A total of 103 patients with arteriosclerosis obliterans at femoral artery who underwent femoral endarterectomy from Jan. 2012 to Jan. 2017 in our hospital were retrospectively selected as subjects of this study, to compare the clinical feathers between restenosis group and patent group, and then exploring the influencing factors for restenosis after femoral endarterectomy. Results Thirty-six patients (35.0%) suffered from restenosis after femoral endarterectomy. Patients in the restenosis group had a high proportion of high smoking and diabetes mellitus, and high level of low density lipoprotein than those corresponding indexes of the patent group (P<0.05). Results of Cox proportional hazard model showed that, diabetes mellitus 〔RR=3.338, 95% CI was (1.003, 11.113), P=0.049〕 and high level of low density lipoprotein 〔RR=3.311, 95% CI was (1.166, 9.397), P=0.024〕 were independent risk factors for restenosis after femoral endarterectomy. Conclusions Monitoring of high-risk factors like controlling blood glucose strictly and strengthening statin treatment should be done to reduce the risk of restenosis after femoral endarterectomy for patients with arteriosclerosis obliterans at femoral artery.
ObjectiveTo evaluate efficacy and safety of treatment of Kommerell diverticulum with endovascular technique.MethodThe retrospective analysis was made on the preoperative clinical data, surgical treatment, and postoperative status of patient with Kommerell diverticulum who underwent the endovascular treatment in the Department of Vascular Surgery, Xuanwu Hospital of Capital Medical University.ResultsAccording to the different types and clinical symptoms, the effective endovascular treatment was adopted. The thoracic endovascular aortic repair and coil embolization of Kommerell diverticulum were successfully performed. The postoperative aortic blood flow was unobstructed and the aneurysmal lesion was completely isolated. No endoleakage and intracranial and upper limb ischemia were occurred. The operation time was 55 min and the blood loss was 20 mL. The patient was discharged on day 6 after the operation. No endoleakage, dizziness, and upper limb numbness were found following-up for 12 months.ConclusionFor patient with different types of Kommerell diverticulum and different symptoms, who could be treated by appropriate endovascular treatment and it is effective and safety.
Objective To explore the middle-term outcome of autologous bone marrow mononuclear cells transplantation in the treatment of lower l imb ischemia. Methods From March 2003 to June 2005, 65 patients with lower l imb ischemia were treated by autologous bone marrow mononuclear cells transplantation. Of the patients, there were 50 males and 15 females, with a mean age of 66.5 years (range 36-89 years), including 4 cases of simple arteriosclerotic occlusion,5 cases of thromboangiitis obl iterans and 56 cases diabetic lower l imb ischemia. A total of 400 mL bone-marrow blood were extracted from the posterior superior il iac crest. And then the mononuclear cells were isolated from the bone-marrow blood in the laboratory. The amount of transplantation bone marrow mononuclear cells was (0.60-1.80) × 109 (mean 1.05 × 109). Twelve patients received cell transplantation from two to four times and the other patients one time. According to the improvement of cl inical finding, the outcome was evaluated. Results All the patients were followed up for 8-56 months (mean 21.5 months). There were 8 deaths, and the mortal ity was 12.3%; 5 were due to myocardial infarction and heart failure and 3 were due to cerebral infarction. The general effective rate was 70.8% (46/65) and the recurrent rate was 10.7% (7/65). Of them, the response to treatment lasted over 12 months in 42 cases, accounting for 91.3% (42/46); over 24 months in 24 cases, accounting for 52.2% (24/46); and over 37 months in 12 cases, accounting for 26.1% (12/46). The effective rates were 100% in 12 patients who received 2-4 times transplantation and 64.2% in 53 patients who received 1 time transplantation, showing statistically significant difference between them (P lt; 0.001). Conclusion The middle-term outcome of autologous bone marrow mononuclear cells transplantation show that it is a feasible and simple method for treatment of lower l imb ischemia.