等离子熔射成形模拟系统设计与研究

设计并开发了一种等离子熔射成形过程的数值模拟系统.系统描述了从射流至基体的整个熔射成形过程以及各对象的状态和行为,并生成熔射成形过程的三维动画.在分析中同时考虑射流、熔射粒子、皮膜的影响因子对熔射结果的影响,找出部分主要工艺参数对熔射的影响规律.由等离子熔射铁片模拟所得到的计算结果与实验观测现象基本符合,表明了此系统用于系统地模拟和分析等离子熔射成形过程是可行的.

Enhanced expression of epidermal growth factor receptor gene in gastric mucosal cells by the serum derived from rats treated with electroacupuncture at stomach meridian acupoints

AIM: To investigate the effect of serum derived from rats treated with electroacupuncture at stomach meridian acupoints on the expression of epidermal growth factor receptor (EGFR) gene in gastric mucosal cells. METHODS: The stress-induced gastric mucosal injury in rat model was established by water-immersion and restrained stress methods. 52 rats were randomly divided into: normal group (n = 8), model group (n = 8), model serum group (n = 12), stomach serum group (n = 12), and gallbladder serum group (n = 12). The gastric mucosal cells were separated by pronase-EDTA digestion method and incubated with serum. The EGFR gene expression in gastric mucosal cells was detected by reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS: Compared with normal group (0.6860 ± 0.0594), the serum derived from rats of the stomach group (1.2272 ± 0.0813, P = 0.00 < 0.01) and gallbladder group (0.9640 ± 0.0387, P = 0.00 < 0.01) had a tendency to enhance the EGFR gene expression in gastric mucosal cells. Such tendency existed in the model group (0.7104 ± 0.0457) but with no signifi cant difference (P = 0.495 > 0.05) and in model serum group (0.8516 ± 0.0409) with an extremely obvious difference (P = 0.001 < 0.01). Furthermore, the EGFR gene expression in stomach serum group was significantly higher than that in gallbladder serum group (P = 0.00 < 0.01). CONCLUSION: The present study shows that serumderived from rats treated with electroacupuncture at stomach meridian acupoints can distinctly increase the EGFR gene expression of gastric mucosal cells. Therefore, there is certain meridian specificity in the serum, which could provide a proof for the TCM theory “particular relation between meridian and internal organ”.

Inhibition of invasiveness and expression of epidermal growth factor receptor in human colorectal carcinoma cells induced by retinoic acid

Human amniotic basement membrane (HABM) model and agarose drop explant method were used to in-vestigate the effects of retinoic acid(RA) on the invasive-ness alld adhesiveness to the basement membrane, and the migration of a highly invassive human colorectal cancer cell line CCL229. Results showed that 5 ×106 MRA markedly reduced the in vitro invasiveness and adhesiveness to the HABM, and the migration of the CCL229 cells. In addi-tion, to elucidate the relation between expression of epider-mal growth factor receptor (EGFR) and the invasiveness of the colorectal carcinoma cells, two well-differentiated, but with different invasiveness colorectal cancer cell lines were compared at mRNA level for expressioll of EGFR by using EGFR cDNA probe labeled with digoxigenin (DIG). Expression of EGFR was showll to be markedly higher in the highly invassive CCL229 cells than that in the low in- vasive CX-1 cells. Furthermore, expression of EGFR in RA treated CCL229 cells gradually decreased with time,the level being the lowest on day 6 of the RA treatment.

Cytocompatibility of Three Corneal Cell Types with Amniotic Membrane

Rabbit limbal corneal epithelial cells,corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopic examinations were carried out to observe the growth,arrangement and adhesion of cultivated cells. Results showed that three corneal cell types seeded on amniotic membrane grew well and had normal cell morphology. Cultured cells attached firmly on the surface of amniotic membrane. Corneal epithelial cells showed singular layer or stratification. Cell boundaries were formed and tightly opposed. Corneal endothelial cells showed cobblestone or polygonal morphologic characteristics that appeared uniform in size. The cellular arrangement was compact. Keratocytes elongated and showed triangle or dendritic morphology with many intercellular joints which could form networks. In conclusion,amniotic membrane has good scaffold property,diffusion effect and compatibility with corneal cells. The basement membrane side of amniotic membrane facilitated the growth of corneal epithelial cells and endothelial cells and cell junctions were tightly developed. The spongy layer of amniotic membrane facilitated the growth of keratocytes and intercellular joints were rich. Amniotic membrane is an ideal biomaterial for layering tissue engineered cornea.

CIN85 associates with endosomal membrane and binds phosphatidic acid

CIN85 （Cbl-interacting protein of 85 kDa） is an important molecule involved in receptor tyrosine kinase endocytosis. Here we report that through its positively charged C-terminus, CIN85 associates with a fusogenic lipid - phosphatidic acid. Its coiled-coil domain plays an important role in mediating this protein-lipid interaction. Deletion of the coiled-coil domain results in loss of membrane association, and reduced interaction with c-cbl, finally causing the blockage of epidermal growth factor receptor downregulation. In addition, a significant portion of CIN85 is located on the endosomal compartment and is related to endocytic cargo sorting, characterized by CIN85＇s localization on the ＂E class＂ compartment and EGF degradation blockage in CIN85 knockdown cells. Taken together, our results suggest that CIN85 may function as a scaffold molecule in both the internalization and endocytic cargo sorting processes through its association with the endosomal membrane.

Vascular endothelial growth factor gene transfer improves host endothelialization of xenogeneic biologic heart valve in vivo

OBJECTIVE: To investigate the feasibility of endothelialization of bioprosthesis by transfer of vascular endothelial growth factor (VEGF) gene. METHODS: Bovine pericardium treated with glutaraldehyde and L-glutamic acid was positioned into the pig right atrium. pcD(2)/hVEGF(121) gene (1 mg) was transferred into the right ventricular myocardium using surgical sutures Reverse transcri ption polymerase chain reaction (RT PCR) was employed to evaluate the expression of myocardial VEGF mRNA. The determination of concentrations of VEGF protein in blood from both the right atrium and peripheral vein, and histological and ultrastructural analysis of implanted bovine pericardium were completed simultaneously. RESULTS: The concentration of VEGF derived from the right atrium in pcD(2)/hVEGF(121) group was significantly higher than that in the pcD(2) group 10 days after VEGF gene transfer (P

An efficacy analysis of anti-vascular endothelial growth factor therapy for choroidal neovascularization secondary to multifocal choroiditis and comparison with wet age-related macular degeneration

Objective： To evaluate the effect of anti-vascular endothelial growth factor （VEGF） on juxtafoveal choroidal neovascularization （CNV） secondary to multifocal choroiditis （MFC） and wet age-related macular degeneration （AMD）. Methods： In this retrospective, comparative study, 20 unique eyes with CNV were divided into two groups： 10 patients affected by MFC and 10 patients diagnosed with wet AMD. They all received local intravitreal （Ivr） injections of ranibizumab, with 6 months of follow-up. Retreatment injections were performed based on findings suggestive of active neovascularization. Results： Significant improvements were observed in the juxtafoveal CNV lesions, and average central macular thickness decreased in both groups following the anti-VEGF therapy （P〈0.05）. The average number of injections used in MFC patients was 1.6, while three injections on average were used in wet AMD patients （Z=-2.844, P=0.009）. Best-corrected visual acuity was significantly improved in MFC patients after anti-VEGF therapy （P〈0.05）, and there was no significant difference in wet AMD patients between before anti-VEGF therapy and 6 months later （P〉0.05）. Conclusions： IVT ranibizumab resulted in good clinical outcomes for juxtafoveal CNV secondary to MFC and wet AMD, but the average number of injections used in MFC was fewer than that used in wet AMD over a 6-month observation period. Compared with the wet AMD group, visual acuity was obviously improved in the MFC group at 6 months.

Effects of moxibustion pretreatment on extracellular signal-regulated kinase signaling transduction pathway in the gastric tissues of rats with gastric mucosal damage

Objective： To observe the effects of moxibustion pretreatment on the protein expressions of epidermal growth factor receptor （EGFR）, phosphorylation extracellular signal-regulated kinase I/2 （p-ERKI/2） and activated protein-1 （AP-2）, the key factors of extracellular signal-regulated kinase signaling transduction pathway in gastric tissue of rats with stress-induced gastric mucosal damage, and to discuss the mechanisms of moxibustion therapy in promoting the restoration of damaged gastric mucosa. Methods： Thirty Sprague-Dawley （SD） rats were randomly divided into a normal group, a model group, and a moxibustion group using the random digits table, 10 in each group. Except the rats in the normal group, rats in the other two groups were used to make stress-induced gastric mucosal damage model using restraint and cold stress. Before modeling, rats in the moxibustion group were alternately treated with moxibustion a/t Zusanli （ST 36） and Zhongwan （CV 12）, or Pishu （BL 20） and Weishu （BL 22）, once a day, for a total of 8 d. Histolo^cal changes of gastric mucosa were observed under the light microscopy, the expression of gastric tissue p-ERKI/2 was detected by immunohistochemistry assay, and the protein levels of EGFR and AP-I were measured by Western blots. Results： Compared with rats in the normal group, gastric mucosal damage was more serious, and protein expressions of gastric tissue EGFR, p-ERK1/2 and AP-1 increased in the model group （P〈0.01, P〈O.05, P〈0.05）. Compared with rats in the model group, gastric mucosal damage was milder, and protein expressions of gastric tissue EGFR, p-ERK1/2 and AP-1 increased in the moxibustion group （all P〈0.01）. Conclusion： Moxibustion at Zusanli （ST 36）, Zhongwan （CV 12）, Pishu （BL 20） and Weishu （BL 21） could increase EGFR, p-ERK1/2 and AP-1 expression levels in gastric tissue of stress-induced gastric mucosal damage rats, maintain the information transfer function of ERK signaling transduction pathway, and promote restoration of gastric mucosal damage.

Inhibition effect of small interfering RNA of connective tissue growth factor on the expression of vascular endothelial growth factor and connective tissue growth factor in cultured human peritoneal mesothelial cells

Background The peritoneum response to peritoneal dialysis can lead to fibrosis. The transforming growth factor β1 （TGF-β1 ） plays a key role in regulating tissue repair and remodelling after injury. Connective tissue growth factor （CTGF）, a downstream mediator of TGF-β1 inducing fibrosis, has been implicated in peritoneal fibrosis. Vascular endothelial growth factor （VEGF） plays a key role in angiogenesis that can hasten peritoneal fibrosis. In this study, we investigated the effect of small interfering RNA （siRNA） of CTGF by pRETRO-SUPER （PRS） retrovirus vector on the expression of CTGF and VEGF in human peritoneal mesothelial cells. Methods Retrovirus producing CTGF siRNA were constructed from the inverted oligonucleotides and transferred into packaging cell line PT67 with lipofectamine, and the virus supernatant was used to infect human peritoneal mesothelial cell （HPMC）. The cells were divided into seven groups： low glucose DMEM, low glucose DMEM ＋ TGF-β1 5 ng/ml, low glucose DMEM ＋ TGF-β1 5 ng/ml ＋ PRS-CTGF-siRNA1-4 and low glucose DMEM ＋ TGF-β1 5 ng/ml ＋ PRS. The expression of CTGF and VEGF were measured by semiquantitative RT-PCR and Western blot. Results Low levels of CTGF and VEGF were detected in confluent HPMCs. Following stimulation with TGF-β1 , the levels of CTGF and VEGF were significantly upregulated （P〈0.01）. Introduction of PRS-CTGF-siRNA1-4 resulted in the significant reduction of CTGF mRNA and protein, and VEGF mRNA （P〈0.01）, especially in groups PRS-CTGF-siRNA, and PRS-CTGF-siRNA4. The introduction of PRS void vector did not have these effects （P〉0.05）. Conclusions The expression of CTGF siRNA mediated by PRS retrovirus vector can effectively reduce the level of CTGF and VEGF induced by TGF-β1 in cultured HPMCs. This study may provide potential therapeutic strategies to prevent the peritoneal fibrosis.

Relation between eardrum flap area and healing outcome of traumatic eardrum perforation

Objective： To retrospectively study the clinical effects of eardrum flap area on the healing outcome following traumatic perforation.Methods： Totally 291 traumatic eardrum perforations with in-/everted edges were included in this study. They were randomly divided into three groups and received conservative treatment, epidermal growth factor （EGF） via Gelfoam patching, or edge-approximation plus Gelfoam patching respectively. Patients in each group were further divided into two subgroups according to the eardrum flap area ≤ 1/2 or 〉1/2 of the perforation size. The healing rate and mean closure time after tympanic membrane perforation were evaluated at three months.Results： Of the total 291 participants, 281 were included in the final statistical analysis. The area of curled edge did not affect the healing outcome significantly in any groups （P〉0.05）. The healing rate varied slightly： 90.7% vs 92.3% in spontaneous healing group, 98.2% vs 97.4% in EGF via Gelfoam patching group, and 96.5% vs 100% in edge-approximation plus Gelfoam patching group. In addition, in all groups the area of curled edge did not affect the mean closure time significantly （P〉0.05）. The closure time was （32.3±2.4） d vs （30.6±3.1） d in sponaneous healing group, （13.4±2.5） d vs （13.1± 1.9） d in EGF via Gelfoam patching group, and （11.9±3.1） d vs （12.2±2.1） d in edge-approximation plus Gelfoam patching group.Conclusion： The eardrum flap area of traumatic eardrum perforation does not significantly affect the clinical outcomes.