Purpose:To determine the efficacy of a low-molecular-weight heparin (fraxipparine) administered in the infusion fluid to prevent postoperative fibrin formation in a rabbit lensectomy and vitrectomy model. Methods:Fourteen adult pigmented rabbits were randomly as signed into two groups.Standard fragmatome lensectomies and core vitrectomies were performed prospectively in a masked fashion on control eyes with balanced salt infusion and on experimental eyes treated with fraxiparine/ml 6U in the infusate.Intraoperative bleeding was graded in a masked fashion by the surgeon. The amounts of firbrin and hemorrhage were graded in a masked fashion on postoperative days 1 through 7. Results:The mean grde of fibrin in the eyes treated with fraxiparine was lower than that in the control eyes (Plt;0.01) on postoperative days 1 through 3 respectively.Also,the average days to clear the fibrin in the eyes treated with fraxiparine was shorter than that in the control eyes (P＝0.001).No statistically significant differences in the degree of intraoperative or postoperative hemorrhage were noted between the two groups. Conclusion:Low-molecular weight heparin(fraxiparine) is an effetive inhibit or of postoperative fibrin formation in a rabbit model and is not associated with is not associated with an increased risk of intraoperative or postopertive bleeding at the tested dose. (Chin J Ocul Fundus Dis,1998,14:35-37)
As a risk factor for vascular diseases and inflammatory diseases, fibrinogen has received more and more attention. Hyperfibrinogenemia is associated with the occurrence, development, and poor outcome of artery-venous ischemic stroke (acute ischemic stroke, transient ischemic attack and cerebral venous thrombosis). Therefore, fibrinogen may be a potential therapeutic target for the prevention and management of artery-venous ischemic stroke. However, there has been controversy regarding the defibrinogen therapy in artery-venous ischemic stroke. Therefore, this paper introduces the efficacy and safety of defibrinogen therapy alone, combined with antiplatelet or combined with anticoagulant in prevention and management of artery-venous ischemic stroke in detail, in order to re-understand the role of defibrinogen therapy in the prevention and management of artery-venous ischemic stroke.
Objective To analyze MC3T3E1 cell morphology, prol iferation, and osteogenic differentiation in fibrin gel (FG) so as to lay a fundament for use of FG in tissue engneering. Methods MC3T3E1 cells were incubated in three concentrations (20, 10 and 5 mg/mL)of FG as the experimental groups (groups A, B and C) and in the common medium culture as the control group (group D). The cell morphology and distribution in FG were observed by inverted phase contrast microscope and confocal laser scanning microscope at different time. The cell prol iferation was assessed by fluorospectrophotometer. The alkal ine phosphatase (ALP) activity was detected by automatic biochemistry analyses and von Kossa staining was used to analyze calcium salts mineralization. RT-PCR was used to analyze the ALP and bone sialoprotein (BSP)mRNA expression at 14 and 21 days. Results In groups A, B and C, the MC3T3E1 cells had long processes which connected each other and formed network; but fusiform or cube cells were observed in group D at 21 days. The fluorescence intensity was increased gradually with time, was the highest at 14 days and the lowest at 28 days in group D; it was highest in groups A, B and C at 28 days, there were statistically significant differences when compared with group D (P lt; 0.05). The ALP activity was increased gradually with time, and it was the highest at 28 days in group D and at 21 days in groups A and B, there were significant differences (P lt; 0.05), no statistically significant differences compared with group D at other time points (P gt; 0.05). The mineral ization nodus were seen at 21 and 28 days in group A, but no mineral ization nodus was seen in group D at 28 days. The RT-PCR results showed the mRNA expressions of ALP and BSP were enhanced in group A when compared with group D (P lt; 0.05). Conclusion The osteogenic differentiation was most obvious and cell prol iferation was most active after 21 days of incubation in FG.
The fundus lesions caused by high myopia (HM) often lead to irreversible visual impairment or even blindness. However, the pathogenesis of HM and its fundus lesions is still unclear, the intraocular fluid detection technology of micro samples has brought new prospects for the early diagnosis, monitoring and intervention of the fundus lesions. The molecules associated with HM are various and functionally diverse, intermolecular interactions are staggered and the specific mechanism is complex. With the development of intraocular fluid detection technology, while gradually revealing the role of each molecule in the pathogenesis of HM, it is expected to successfully assist clinical work in the future, providing outpost markers for the progress of myopia and targets for early intervention, or providing a new therapy choice for HM fundus lesions at the molecular level targeting pathogenesis, which is expected to provide more accurate and effective treatment for HM patients in the future.
【Abstract】Objective To explore the differential diagnostic value of major fibrinolytic parameters in pleural fluid. Methods Tissue-type plasminogen activator( t-PA) and plasminogen activator inhibitor-1( PAI-1) in pleural fluid at the first thoracentesis were measured with ELISA and D-dimer was measured with immunoturbidimetry. Results Eighty-four patients with pleural effusion were enrolled, among which 40 with malignant effusion, 33 with infectious effusion and 11 with transudative effusion. t-PA level was higher in malignant and transudative pleural fluid than that in infectious pleural fluid[ ( 52. 49 ±31. 46) ng /mL and ( 58. 12 ±23. 14) ng /mL vs ( 37. 39 ±22. 44) ng /mL, P lt; 0. 05] , but was not statistically different between malignant pleural fluid and transudative ( P gt; 0. 05) . PAI-1 level was higher in malignant and infectious pleural fluid than that in transudative [ ( 164. 86 ±150. 22) ng/mL and ( 232. 42 ±175. 77) ng/mL vs ( 46. 38 ±16. 13) ng/mL, P lt; 0. 01] , but was not statistically different between malignant and infectious pleural fluid( P gt;0. 05) . D-dimer levels in the three types of pleural fluid were significantly different, which was ( 23. 66 ±25. 18) mg/L, ( 6. 36 ±10. 87) mg/L and ( 66. 90 ±42. 17) mg/L in malignant, transudative and infectious pleural fluid, respectively. As single-item detection for malignant pleural fluid, the cutoff of t-PA was gt; 38. 7 ng/mL( area under ROC curve was 64. 0 ) , with sensitivity of 60. 0% , specificity of 63. 6%, positive predictive value of 66. 7%, negative predictive value of 56. 8% and accuracy of 61. 6% .The cutoff of D-dimer was lt; 27. 0 mg/L( area under ROC curve was 85. 5) , with sensitivity of 84. 8% ,specificity of 72. 5% , positive predictive value of 85. 3% , negative predictive value of 71. 8% and accuracy of78.1%. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of combined examination( t-PA + D-dimer) were 92. 5% , 60. 6% , 74. 0% , 87. 0% , 78. 1% , respectively.Conclusions The t-PA, PAI-1 and D-dimer levels are significantly different in the three types of pleural fluid. The detection of fibrinolytic parameters in pleural fluid, especially the value of D-dimer,may be helpful in the differential diagnosis of pleural effusion.
In order to observe the effects of different facing directions of the germinal layer of periosteum on the cartilage regeneration, the human fibrin adhesive agent was used to adhere autogenous periosteum to repair the articular cartilage defect of rabbits. Twentyfour rabbits with 48 knee joints were divided randomly into two groups. A 0.6cm×1.2cm articular cartilage defect was created on the femoral trochlea until there was bleeding from the subchondral bone. A piece of periosteum, sized 0.75cm×1.5cm, was removed from the medial aspect of upper tibia. The periosteum was adhered to the defect by human fibrin adhesive agent. In Group 1 the germinal layer faced the subchondral bone and in Group 2 the germinal layer faced the joint cavity. The cartilage regeneration in both groups was observed by naked eyes and light microscope in 2nd and 6th weeks and by electron microscope after Safronin Ostained in 12th and 20th weeks. The results showed that before the 6th week, the cartilage regeneration was faster in Group 2 than that in Group 1. After that there was no significant difference in regeneration between the two groups. This suggested that the facing direction of the germinal layer was not a critical factor on cartilage regeneration. It was also found that the strength of the adhesive agent was not enough. The regenerated cartilage was proved to be hyaline cartilage.
ObjectiveTo evaluate the safety and efficacy of second central venous catheterization in tunnel cuffed dialysis catheter (TCC) dysfunction with fibrin sheath.MethodA total of 14 maintenance hemodialysis patients who required second central venous catheterization were enrolled in West China Hospital of Sichuan University from June 2016 to June 2017 and the clinical information and procedure-related complications were recorded.ResultsAll of the 14 patients were successfully performed with second central venous catheterization, of whom 4 cases had superior vena cava cannulation, 7 cases had right brachiocephalic vein cannulation, 2 cases had internal jugular vein cannulation, and 1 case had external jugular vein cannulation. No procedure-related major complication occurred. During the follow-up, catheter malfunction occurred in 2 cases, which improved by urokinase seal and catheter change, respectively. The rest patients’ catheter function remained normal.ConclusionsWith increasing difficult to construction and maintenance of vascular access, preservation of central vein resource is of high importance. For patients with TCC dysfunction with fibrin sheath, second central venous catheterization based on percutaneous brachiocephalic vein or superior vena cava cannulation is a safe and effective method to establish the lifeline for hemodialysis patients.
As a potent collagenase activator, ocriplasmin is a recombinant truncated form of serine protease that retains the protease activity of plasmin. Pre-clinical animal experiments, clinical trials and recent clinical studies all indicated a promising outcome of intravitreal injection of ocriplasmin to treat vitreomacular interface diseases, including vitreomacular adhesion (VMA), vitreomacular traction (VMT) and full-thickness macular hole. Ocriplasmin was approved by the Food and Drug Administration of USA in the management of symptomatic VMA, and by the European Medicines Agency in treating VMT-associated macular hole with less than or equal 400 μm. Further randomized controlled clinical trials are needed for further comprehensive observation and evaluation on its efficiency, safety and other noteworthy issues.
Objective To investigate the effect of local delayed releasing vascular endothelial growth factor (VEGF) on accelerating healing of intestinal anastomotic stoma. Methods An intra-abdominal infection modal of rabbit was established by artificial appendix perforation, and excision and anastomosis of terminal ileum were subsequently performed after 12 h. The animals were divided into four groups (32 for each group) with different reagents on anastomotic surface: control group, fibrin glue group (FG group), VEGF group, and VEGF＋FG group. The incidence of stomal leak, anastomosic bursting pressure, hydroxyproline content, and expression of VEGF in cured stoma tissue were measured respectively on day 3, 5, 7 and 14 after operation. Results The total incidence rate of leakage was lower in FG group and VEGF group than that in control group, but there was no statistical significance （Pgt;0.05）. The incidence rate was significantly lower in FG＋VEGF group than that in control group （Plt;0.05）. On day 14 postoperatively, the bursting pressure of anastomotic stoma, hydroxyproline content, and positive cell expression rate of VEGF protein (except VEGF group) were significantly increased in FG＋VEGF group than those in other three groups （Plt;0.05, Plt;0.01）. Conclusion Local delayed release of VEGF by fibrin glue can improve the healing of intestinal anastomotic stoma and reduce the incidence of stomal leak.
【Abstract】 Objective To broaden the cl inical uses of fibrin-based biomaterials and to develop further study incell biology and to comprehensively understand and master related knowledge with regard to the present development status of fibrin. Methods Many relevant domestic and international papers were reviewed to make a summary. Results Recognization was obtained from four aspects, which were structure and function of fibrinogen, cl inical use of fibrin, fibrin scaffold for tissue engineering, and compounding biomaterials of fibrin. It showed that every aspect had great research extension and practical appl ication. Conclusion Besides a surgical hemostat and sealant, fibrin has great potentials in playing roles of tissue engineering scaffold, drug del ivery vehicle, and compounding material.