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.
Objective To explore the effective autologous bone marrow stem cell dosage for treatment of severe lower limb ischemia. Methods From December 2003 to December 2004, 22 cases of bilateral lower limb ischemia were treated with autologous bone morrow cell transplantation. All the patients were randomly divided into two groups according to ischemia degree. In group A(severe ischemia side), the amount of transplanted autologous bone marrow cells was more than 1×108, and ingroup B(mild ischemia side), the amount was less than 1×105. A series of subjective indexes, such as improvement of pain, cold sensation and numbness, and objective indexes, such as increase of ankle/brachial index (ABI) and transcutaneous oxygen pressure (TcPO2), angiography, amputation rate, and improvement of foot wound healing were used to evaluate the effect of autologous bone marrow stem cells implantation. Results The rates of pain relief were 90.0% in group A and 16.7% in group B (Plt;0.01); the rates of cold sensation relief were 90.5% in group A and 5.3% in group B（Plt;0.01）;the improvement of numbness was 62.5% in group A and 9.1% in group B（Plt;0.01）. Increase of ABI was 31.8% and 0 in groups A and B respectively（Plt;0.01） at 4 weeks after implantation. Increase of TcPO2was 94.4% and 11.1% in groups A and B respectively（Plt;0.01） at 4 weeks after implantation. Twelve cases of angiography showed rich new collateral vessels in 100% of the limbs in group A while no remarkable new collateral vessel in group B. The amputation rates were 4.5% in group A and 27.3% in group B（Plt;0.05） at 4 weeks after implantation. The rate of improvement of foot wound healing was 75% in group A and there was no changein wound healing in group B after 4 weeks of implantation. Conclusion The effectiveness of autologous bone marrow stem cell implantation depends on the number of implanted stem cells. Effectiveness is expected in most patients if the implanted stem cell is more than 1×108, whereas there would be little effect if the cell number is less than 1×105.
Objective To summarize the research progress of gene-based therapeutic angiogenesis in lower limb ischemia, so as to provide a new method for non-invasive treatment of lower limb ischemia. Method The literatures on studies of gene-based therapeutic angiogenesis in lower limb ischemia in recent years were read and reviewed. Results The incidence of peripheral arterial disease had been increasing annually. How to effectively reduce the amputation rate and mortality rate of patients with critical limb ischemia was still a clinical problem that needs to be solved urgently. A large number of basic and clinical studies had shown that gene-based therapeutic angiogenesis could effectively induce angiogenesis and collateral circulation in ischemic tissue of lower limb, leading to the significant improvements of blood perfusion in ischemic areas. Additionally, the construction of many kinds of new non-viral gene delivery vectors could also improve the safety and effectiveness of gene therapy to a certain extent. Conclusion Although promising therapeutic effect of gene-based therapeutic angiogenesis brings new ideas and strategies for the treatment of lower limb ischemia, issues still exist that have not been solved.
Sepsis-associated organ dysfunction arises from uncontrolled inflammation and immune dysregulation, causing microcirculatory impairment and multi-organ failure. Stellate ganglion block (SGB) may confer organ protection by regulating the sympathetic nervous system and hypothalamic-pituitary-adrenal axis to suppress excessive inflammation and oxidative stress. Available evidence, mainly from experimental and small clinical studies, suggests potential benefits of SGB in sepsis-induced acute lung injury, ventricular arrhythmias, and limb ischemia, which require confirmation in multicenter randomized controlled trials. This review outlines the mechanisms and clinical advances of SGB in sepsis-related organ dysfunction, providing a theoretical basis for its application in critical care.
ObjectiveTo study the effect of exogenous insulin on inducing angiogenesis and the expression of vascular endothelial growth factor (VEGF) of hindlimb ischemia of rats with diabetic. MethodsThe hindlimb ischemic model of diabetic rat was established by the ligation of femoral blood vessels of hindlimb in twenty healthy male SD rats and which were divided into model group (n=10) and treatment group (n=10). Another 10 normal rats were selected as control group. Then the expression of VEGF protein and capillary density of muscle tissues of rat hindlimb were detected by Western blot analysis and alkaline phosphatase (APK) stain method, respectively. ResultsThe differences of body weight and blood glucose level of rats before operation and on day 7 after operation were not significant in the control group (Pgt;0.05). The body weight of rat was significantly lower on day 7 after operation than that before operation in the model group (Plt;0.05), while the difference of blood glucose level of rats was not significant in the model group (Pgt;0.05). The body weight and blood glucose level of rat significantly decreased in the treatment group on day 7 after subcutaneous injection of insulin as compared with the level before operation (Plt;0.05). Compared with the control group, the body weight decreased and blood glucose level increased in the model group and treatment group, and the difference was significant (Plt;0.05, Plt;0.01). The body weight of rat in the treatment group was not different from that in the model group (Pgt;0.05), but the blood glucose level of rat on day 7 after operation in the treatment group was significantly lower than that in the model group (Plt;0.05). The relative expression of VEGF protein of muscle tissues of ischemic hindlimbs in the treatment group (155.06±10.26) was significantly higher than that in the model group (94.30±11.23), Plt;0.05, while no expression was found in the control group. The capillary density of muscle tissues of right hindlimb in the control group was significantly higher than that in the model group or treatment group (Plt;0.05), and furthermore, which was higher in the treatment group than that in the model group (Plt;0.05). The difference of capillary density of muscle tissues of left hindlimb was not different among three groups (Pgt;0.05). The capillary density of muscle tissues of right hindlimb was not different from that of left hindlimb in the control group (Pgt;0.05) and which was significantly lower than that of left hindlimb in the model group or treatment group (Plt;0.05). ConclusionInsulin may increase the expression of VEGF protein in ischemic muscle tissue of diabetic rats and protect the ischemic muscle.
Objective To evaluate the effectiveness and safety of autologous hemopoietic stem cell implantation for peripheral arterial disease (PAD). Methods Randomized controlled trials (RCTs) were identified from CBM (1978 to September 2010), CNKI (1979 to September 2010), MEDLINE (1950 to September 2010), Pubmed (1950 to September 2010), Embase (1970 to September 2010), and Cochrane l ibrary (issue 4, 2010). The papers of the RCTs of cl inical therapeutic studieson PAD treated by autologous hemopoietic stem cell implantation were included and analyzed according to the criteria of the Cochrane handbook. Results Eight RCTs involving 280 patients and 322 extremities were included, with majority of trials of low methodological qual ity. Meta-analysis indicated that autologous hemopoietic stem cell transplantation had an increased ulcer cure rate [RD=0.38, 95% CI= (0.25, 0.50)], a significant improvement in the ankle brachial index [MD=0.11, 95%CI= (0.04, 0.18)], transcutaneous oxygen tension [MD=7.33, 95%CI= (3.14, 11.51)], and pain-free walking distance [SMD=1.35, 95%CI= (0.90, 1.79)], a significant reduction in rest pain scores [MD= —1.70, 95%CI= (—2.15, —1.25)], and a significant benefit in terms of l imb salvage [RD= —0.19, 95%CI= (—0.31, —0.07)]. Only 2 trials reported the side effects of autologous hemopoietic stem cell transplantation, such as l imbs swell ing and concentrations of serum creatine phosphokinase increasing, and the long-term safety was not reported. Conclusion Based on the review, autologous hemopoietic stem cell transplantation may have positive effect on “no-option” patients with PAD. However, the evidence is not b enough due to the general low methodological qual ity, so we can not draw a rel iable conclusion about the effects of autologous stem cell transplantation for PAD at the moment. Further larger, randomized, double bl ind, placebo-controlled, and multicenter trials are needed.
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 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 evaluate effect of hypoxia condition (1% or 5% oxygen concentration) on proliferation, adhesion, migration, or viability ability of bone morrow-derived endothelial progenitor cells (EPCs). Methods The bone marrow mononuclear cells of SD rat were acquired with density gradient centrifugation method. They were cultured, induced, and differentiated to the EPCs. Then they were cultured respectively in three different oxygen concentrations (1%, 5%, or 21%). On the 3rd day and the 7th day, the effects of the different oxygen concentrations (1%, 5%, or 21%) on the EPCs’ neovascularization characteristics (including proliferation, adhesion, migration, and viability abilities) were evaluated. Results Whether cultured for the 3rd day or 7th day, the proliferation, adhesion, migration, and viability abilities of the cultured cells in the 1% and 5% oxygen concentrations were significantly better than those of the cultured cells in the 21% oxygen concentration (all P<0.05). Except for the proliferation ability of the cultured cells in the 5% oxygen concentration was significantly better than that of the cultured cells in the 1% oxygen concentration (P<0.05) on the 3rd day, and the adhesion ability on the 3rd day and the proliferation ability on the 7th day had no significantly differences, the other abilities (adhesion, migration, and viability abilities) of the cultured cells in the 1% oxygen concentration were significantly better than those of the cultured cells in the 5% oxygen concentration (allP<0.05). Conclusion Different oxygen concentration has an effect on proliferation, adhesion, migration, or viability ability of bone morrow-derived EPCs, appropriate hypoxia condition (1% or 5% oxygen concentration ) can enhance these abilities.
Objective To observe the clinical efficiency of the implantation of the autologous bone marrow mononuclear cells for treatment of lower limb ischemia after the bone marrow stimulation. Methods From May to December 2005, 43 ischemic limbs in 35 patients (23 males,12 females; aged 3490 years,averaged 71.3 year) were treated. Of the 35 patients, 30 had diabetic lowerlimb ischemia with 38 lower ischemic limbs, 2 had atherosclerosis obliterans with 2 ischemic lower limbs, and 3 had thromboangiitis obliterans with 3 ischemic lower limbs. Five patients with 5 ischemic limbs were in stage Ⅰ lower limb ischemia (intermittentclaudication), 15 patients with ischemic 19 limbs were in stage Ⅱ (rest pain),9 patients with 12 ischemic limbs were in stage Ⅲa(ulceration), and 6 patients with 7 ischemic lower limbs in stage Ⅲb (gangrene); 88.4% of all the ischemic lower limbs （38/43）had a pain, 79.1%（34/43） had coldness, and 69.8%（30/43）had limb numbness. The bone marrow of each patient was stimulated by an injection of the recombinant human granulocyte-macrophage colony-stimulatory factor 300 μg/d for 2-3 days. The bone marrow 130-200 ml was drawn from the iliac spine and the mononuclear cells were obtained. Each patient received implantation of the autologous bone marrow mononuclear cells by an intramuscular injection, an arterial intraluminal injection or a combined injection of the two routes.Results The pain relief was found in 94.7% of theischemic lower limbs, and pain improvement in 97.1% . Relived numbness was found in 93.3%. The distance of the claudication was increased by all the ischemic limbs. An increase in the ankle/ brachial index (ABI)was found in 47.9%. The transcutaneous oxygen pressure (TcPO2) increased in 92.3%. The ulcer heal rate was 9.1% (1/11). Markedlyreduced ulcer wound was found in 27.3% (3/11). The amputation rate was 6.3% (3/48). Arterial angiography revealed that there was a new collateral vessel formationin 91.2%. Complications were as follows: fever and mild fatigue-developed respectively in 1 patient after the bone marrow stimulation, but relieved by themselves. Acute but mild myocardial infarction was found in 1 patient with a slight precordial pain and elevation of myocardial enzymes 1 week after transplantation of the bone marrow mononuclear cells, but recovered after medical treatment. The follow-up averaged 5 months. According to the subjective criteria, the overall efficacy was90%. ABI increased in 62.5% of the patients after operation and the value of TcPO2 was higher in 90% of the patients after this kind of therapy. Arterial angiography revealed a new collateral vessel formation in 90.5% of the 21 ischemic limbs. The foot ulcer healed in 7 and obviously improved in 3. Three of the foot ulcer patients were discharged 2-3 months after the amputation was performed on the diseased toes. Conclusion Implantation of the autologous bone marrow mononuclear cells after the bone marrow stimulation of treatment of the lower limb ischemia has advantages of less marrow aspiration, more mononuclear cell content, satisfactory shortterm effect, and relatively high safety. Itis a new method of treating the lower limb ischemia besides the autologous bone marrow and peripheral blood mononuclear cell implantation. The longterm effect of this method needs a further study.