Open construction of experimental abdominal aortic aneurysm swine models with Dacron patch for evaluating endovascular aneurysm repair techniques / 中国医学科学院学报

<p><b>OBJECTIVE</b>To construct an experimental abdominal aortic aneurysm (AAA) swine model with Dacron patch for evaluating endovascular aneurysm repair (EVAR) technique.</p><p><b>METHODS</b>The experimental pigs were generally anesthetized for the open procedure of an aneurysm model creation with Dacron and subsequent arteriography and EVAR with stent graft. Repeat arteriography was performed after 3-month follow-up.</p><p><b>RESULTS</b>AAA models were successfully constructed in all 10 experimental pigs. The average aneurysm diameter was (26.3±3.1)mm, increasing by (15.7±3.1)mm comparing to the primary aorta diameter (10.5±0.4)mm. The aorta diameter before and after the experiment showed significant difference (P<0.001). All the animals were survived after the procedure. One swine died 24 hours after the subsequent EVAR because the covering of both renal arteries by the stent graft. The rest 9 animals survived well after the whole operation and 3-month follow-up. The surviving rates at 1 month and 3 months after the operation were both 90%. One type 2 endoleak (10%) was observed after the EVAR, which disappeared at 3-month follow-up.</p><p><b>CONCLUSIONS</b>Open construction of experimental AAA swine models with Dacron patch is safe and feasible. The model can be used in the developing new EVAR techniques and implant training.</p>

Endovascular repair of aortoiliac aneurysm with a hybrid technique to preserve pelvic perfusion / 中华医学杂志(英文版)

Endovascular aneurysm repair (EVAR) has been proven to be an effective and safe technique for abdominal or iliac artery aneurysm. However, for aneurysms extending to both iliac bifurcations, routine EVAR will occlude both internal iliac arteries (IIAs), which may increase the risk for pelvic ischemia. New endovascular techniques have been developed to preserve the pelvic perfusion in EVAR for such situation. This article reports an endovascular repair of an aortoiliac aneurysm with an external iliac artery (EIA) to the IIA endograft to preserve the pelvic perfusion. First, an endograft was advanced into the left IIA under the help of an inflated aortic balloon. Coils were deployed to embolize the distal type-1 endoleak from the tunnel around the endograft. and an aortouniiliac endograft and an iliac extension were deployed below the renal arteries extending to the right EIA. Finally, a right-to-left femoro-femoral artery bypass was constructed. Angiography at completion and computed tomography after 6 months demonstrated patency of all grafts and complete exclusion of the aneurysm without any endoleak. Endovascular repair with an EIA-to-IIA endograft to preserve the pelvic inflow is a feasible and effective technique for aortoiliac aneurysms. Coil embolization might be an option to repair the distal type of endoleak. The balloon assisted U-turn technique may help advance the endovascular device over a sharp-angled vessel bifurcation.

Lower extremity arterial occlusive disease as a rare complication of Crohn's disease / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the clinical characteristics and treatment strategy of lower extremity arterial occlusive disease in patients with Crohn's disease (CD).</p><p><b>METHODS</b>Clinical information of 9 cases suffering from lower extremity arterial occlusion and CD was investigated retrospectively.</p><p><b>RESULTS</b>All the cases were less than 50 years old and the most were females (8/9). Arterial occlusions occurred in either active (5/9) or inactive (4/9) stage of CD. Besides the arteries of lower extremities, other arteries could also be involved such as aorta, iliac artery, renal artery or mesentery artery. Seven cases had atherosclerotic imaging findings (4 had aortic plaques and 6 had iliac artery stenoses). Embolectomy or thromboendarterectomy were mostly performed. Four (44.4%) cases had recurrent lower limb ischemia.</p><p><b>CONCLUSIONS</b>Arterial occlusive disease is a rare extraintestinal manifestation of CD. A thorough inspection of aorta is necessary. Embolectomy is mostly preferred. Anticoagulation treatment is highly recommended after the operation.</p>

The effects of the Smad3-knockout on the hematopoiesis of mouse / 生物工程学报

The effects of the Smad3- knockout on the hematopoiesis of mouse were investigated in this work. Five pairs of wild type and Smad3- null mice were studied. White blood cell(WBC), red blood cell(RBC) and platelet (PLT) counting of peripheral blood cells were performed with blood obtained from tails. And white blood cells were classified by their morphology. Bone marrow nucleated cells (BMNCs) were counted and classified. The CFU-GM, BFU-E, CFU-GEMM yields were measured in each pair of mice. CFU-S yield of each mouse was measured by injecting bone marrow cells into lethally irradiated 8-10 weeks old wild type female mice. And the pathomorphism of their bone marrows, spleens and livers were observed. As a result, WBC and PLT of Smad3- null mice were significantly higher than those in wild type mice. Smad3- null mice had much more proportion of granulocytes in classification. There wasn't any difference in RBC counting and BFU-E measurement. The yield of CFU-GM increased, while the yields of CFU-GEMM and CFU-S markedly reduced. Bone marrows are actively proliferative, with granulocytosis. The granulocyte/erythrocyte ratio increased. There were no obviously alterative in spleen and liver. Thus Smad3- knockout results in a decreased number of stem and progenitor cells. Moreover hematopoietic differentiation is abnormal with a tendency to forming more granulocytes and platelets. The effect of Smad3 on hematopoiesis is correlative to that of TGF-beta.

Study of biological characteristics of murine dermal mesenchymal stem cells and their enhancement of hematopoiesis recovery / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the characteristics of dermal mesenchymal stem cells (DMSC), and explore whether they could enhance hematopoiesis recovery in vivo as well as facilitate proliferation and differentiation of hematopoietic cells in vitro.</p><p><b>METHODS</b>Multipotential stem cells from the murine dermal mesenchyme were dissociated and cultured as donor cells. After 2 approximately 3 passages, the growth status, cell cycle, immunophenotype and morphology of DMSC were analyzed. Hematopoietic cells were plated onto a feeder layer formed by DMSC, cell count and CFU-GM yields were observed dynamically. Female mice received 5 Gy (137)Cs radiation were injected with DMSC cultured for 2 - 3 passages via tail vein. Cell count and CFU-GM yields of the bone marrow were observed regularly. Pathological study of the liver, spleen and bone marrow was done to evaluate hematopoiesis recovery.</p><p><b>RESULTS</b>Murine DMSC are adherent cells with a morphology of fibroblastoid and spindle and multiangle in shape. Immunophenotypes showed that CD(45), CD(34), HL-DR positive DMSC were 1 - 3%, CD(44) and CD(13) positive DMSC 75 approximately 95%. Cell cycle assay demonstrated 83% of DMSC being G(0)/G(1) phase. In vitro, the total cell count and CFU-GM yields in the experimental group were higher than those of the long-term culture bone marrow cells by the third week. The DMSC can sufficiently support the proliferation and differentiation of hematopoietic cells for seven weeks. In vivo, peripheral granulocytic count, cells in the bone marrow of one femoral bone and CFU-GM by the third week in the experimental group were much higher than those of controls. Genetic assay of the murine blood demonstrated Y chromosome.</p><p><b>CONCLUSION</b>The DMSC have characteristics of stem cells. DMSC sped up hematopoiesis recovery of irradiated mice. DMSC as a feeder layer can support proliferation and differentiation of hematopoietic cells.</p>

Transplantation of mesenchymal derived stem cells followed by G-CSF injection can reconstitute hematopoiesis of lethally irradiated BALB/c mice / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the hematopoietic reconstitution potential of mesenchymal derived stem like cells.</p><p><b>METHODS</b>We transplanted bone marrow mesenchymal derived stem like cells into lethally irradiated BALB/c mice. Hematopoietic cells were derived from the non-adherent bone marrow cells 24 hours after initial culture while murine mesenchymal derived stem like cells from bone marrow of donor mice were cultured for 10 days before the transplantation.</p><p><b>RESULTS</b>All mice of group 1 and 3 died in 7-8 days post irradiation following transplantation, while all the mice from group 2 and 4 survived. The time course of hematopoietic reconstitution was then observed. The peripheral blood and bone marrow cell count recovered in the MSC + G-CSF transplanted group and the BM transplanted group after 3 weeks. Interestingly, CFU-GM number in the MSC + G-CSF transplanted group increased significantly after 2 weeks and even more than that in the BM transplanted group after 3 weeks while as CFU-GM colony dropped 2 weeks after in the BM transplanted group. Spleen colony (CFU-S) number and size of the MSC + G-CSF transplanted group was significantly greater than the BM transplanted group. Furthermore, PCR analysis was performed using peripheral blood cells to determine if any male-derived cells were present. No male-derived cells were found in any of the mice from group 1 and 3. Y-chromosome-specific src gene was found to be dominant in the MSC + G-CSF transplanted group and the BM transplanted group by week 4 post transplantation. In addition, we demonstrated that induction with G-CSF lead to CFU-GM colony formation from MSC compartment in vitro.</p><p><b>CONCLUSION</b>These results indicate that under stimulation of G-CSF, mesenchymal derived stem like cells might differentiate into hematopoietic primitive stem cells in vivo and have the capacity to re-establish hematopoiesis in lethally irradiated mice. This study should provide an alternative transplantation treatment for malignancy.</p>

Identification and isolation of mesenchymal stem cells from human fetal pancreas / 中国医学科学院学报

<p><b>OBJECTIVE</b>To isolate and identify the phenotype and biological characteristics of pancreas derived mesenchymal stem cell.</p><p><b>METHODS</b>Fresh pancreas of 4-5 months old aborted fetus was dissected free from connective tissue, and was cut into small pieces. The adherent cells were harvested and subcultured, after the third subculture, the cells were used for examination. Cell cycle was analyzed by measuring DNA content by FACScan flow cytometer. Phenotype of MSCs was analyzed by immunohistochemical SA technique and differentiated cells were identified by relevant specific staining.</p><p><b>RESULTS</b>Fetal pancreas derived cells gave rise to a population of adherent cells characterized by the presence of a predominant cell type with a typical fibroblast like morphology. By transmission electron microcopy, MSC had few endoplasmic reticulums and mitochondrias. During the log phase of growth, MSC proliferated with a two fold population at 30 h. MSC can be ex vivo expanded by successive cycles of trypsinization, seeding, and culture. Under these conditions, MSC had capability of passaging up to 30 times without displaying significant changes in morphology, with 2-fold increase in cell number after each passage. This indicates the high ex vivo expansion potential of MSC. The results showed that the yield of CFU-Fs was above 200 clones even after the 6th passage. Cell cycle analysis by flow cytometry revealed that more than 83% of cells were in the G0/G1 phases, while a small population of cells were actively engaged in proliferation (S + G2 + M = 17%). We also showed that more than 86% of cells were positive stained by FITC labeled CD44, CD29, CD13, and only about 1% of cells were positive for CD34, HLA-DR. Expression of collagen I, III was positive while vWF was negative. In the differentiation study, we found culture-expanded pancreas MSCs could be directed into the osteogenic lineage as detected by osteoblastic morphology, expression of alkaline phosphatase, modulation of osteocalcin mRNA production and the formation of a mineralized extracellular matrix. We also found that MSCs could give rise to the adipogenic and chondrogenic lineage as evidenced by accumulation of lipid-rich vacuoles within cells and the expression of lipoprotein lipase mRNA or the expression of collagen II and the deposition of proteoglycans.</p><p><b>CONCLUSION</b>Mesenchymal stem cells existing in human pancreas can be isolated by their adherent ability and should be essential to sustain a steady supply of primitive cells in tissue remodeling.</p>

Phenotypical and Biological Characteristics of Human Fetal Marrow and Liver Mesenchymal Stem Cells / 中国实验血液学杂志

There has been an increasing interest in recent years in the stromal cell system. The stroma is a complex tissue, composed of a number vascular and connective tissue cell types including endothelial cells, adipocytes, smooth muscle cells, osteogenic cells, and stromal cells. The marrow mesenchymal stem cells are capable of self-renewal and differentiate into various connective tissue lineages including bone, cartilage, tendon, muscle, fat, and marrow stroma. Recently, techniques for the isolation of adult bone marrow-derived human and animal mesenchymal stem cells have been described, as well as the methods to directing their differentiation into osteogenic, chondrogenic, tendogenic, myogenic, adipogenic, and marrow stromal lineages. But there is no report about the fetal bone marrow- and liver-derived mesenchymal stem cells. Are they the same or not? In our assay, human fetal mesenchymal stem cells from 4 - 5 months old human fetal bone marrow and liver low-density mononuclear cells were cultured, and the cell cycle, immunophenotype and ex vivo expansion properties were studied. Results showed that the mesenchymal stem cells from fetal liver and fetal bone marrow were similar in morphology, growth character and immuno-phenotypes, but the liver mesenchymal cells manifested higher ability to support hematopoiesis than the marrow-derived mesenchymal cells. This study demonstrates that adherent fetal marrow- and liver-derived cells cultured in the absence of differentiation stimulus gave rise to a population of cells with phenotypical features of mesenchymal stem cells, and should be enough to sustain a steady supply of low differentiated cells upon proliferation.