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find Author "YU Bo" 8 results
  • Progress in the application of transcatheter mitral valve edge-to-edge repair in mitral regurgitation

    Over the past 20 years, transcatheter mitral valve edge-to-edge repair (TEER) has become an important treatment option for patients with severe mitral regurgitation (MR) who are at high surgical risk. Initially, several landmark clinical studies established the basis of TEER for primary and secondary MR, but they only involved clinically stable patients with appropriate mitral valve anatomy. With the increasing experience of interventional therapy, the iteration of equipment and the improvement of intraoperative imaging technology, the scope of use of TEER has been continuously expanded, and its indications have been continuously expanded to more complex mitral valve lesions and clinical situations. Therefore, in clinical practice, selecting the appropriate device according to the individual anatomical characteristics of the patient can minimize MR and complications, thereby optimizing immediate and long-term prognosis. This article mainly introduces the pathogenesis and related mechanisms of MR, the main TEER devices and their clinical evidence, the limitations of TEER, and the future development direction.

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  • APPLICATION OF DIFFERENT FLAPS IN IMMEDIATE RECONSTRUCTION OF MAXILLARY DEFECT

    OBJECTIVE: To investigate the method and clinical effect of temporal fascia flap, free forearm flap, free iliac bone transfer and immediate implant on reconstruction of maxillary defect. METHODS: From February 1999 to July 2002, 8 cases of maxillary defects due to excision of cancer were repaired immediately with temporal fascia flap, free forearm flap, free iliac bone transfer and implant. Out of 8 patients, there were 6 males and 2 females, aged 32-49 years, with a disease course of 3 months to 2 years. RESULTS: Free iliac bone and forearm flap survived in all 8 cases. Osseo-integration could be seen and the implants could be used for denture repair and chew function. After 6-12 months, X-ray examination showed iliac bone healing; facial shape and functional restoration were satisfactory. CONCLUSION: Temporal fascia flap, free forearm flap, free iliac bone transfer and immediate implant is an ideal method to repair maxillary defect immediately and reconstruct its function.

    Release date:2016-09-01 09:35 Export PDF Favorites Scan
  • Experimental study on ectopic osteogenesis induced by bone morphogenetic protein 2-derived peptide P24 loaded chitosan-4-thio-butylamidine hydrogel

    ObjectiveTo study the ectopic osteogenesis and biocompatibility of bone morphogenetic protein 2 (BMP-2)-derived peptide P24 loaded chitosan-4-thio-butylamidine (CS-TBA) hydrogel.MethodsFirst, the CS-TBA/hydroxyapatite (HA) solution was prepared by using chitosan, 2-iminothiolane hydrochloride, and HA. Then, the different amount of P24 peptides were added to the CS-TBA/HA to prepare the CS-TBA/5%P24/HA and CS-TBA/10%P24/HA solutions. Finally, β-glycerophosphate disodium (β-GP) was added to the CS-TBA/HA, CS-TBA/5%P24/HA, and CS-TBA/10%P24/HA to prepare the CS-TBA/HA/β-GP, CS-TBA/5%P24/HA/β-GP, and CS-TBA/10%P24/HA/β-GP hydrogels, respectively. Eighteen Sprague Dawley female rats were randomly divided into 3 groups (n=6), which were injected into the back muscle pouches with equal volume CS-TBA/HA/β-GP hydrogel (group A), CS-TBA/5%P24/HA/β-GP hydrogel (group B), and CS-TBA/10%P24/HA/β-GP hydrogel (group C). The animals were sacrificed at 4 and 8 weeks and conducted micro-CT. The ability of biodegradation and osteogenesis of hydrogl was detected by trabecular thickness (Tb.Th), trabecular number (Tb.N), bone mineral density (BMD), and histological staining (HE and Masson).ResultsAll the rats survived to the time point of the harvest. Micro-CT results showed that the new bones gradually increased in each group after operation. At the same time, the new bone formation was more obvious in groups B and C than in group A, and with the increase of P24 concentration, new bone formation in group C was much more than that in group B. The Tb.Th, Tb.N, and BMD increased gradually in 3 groups, and the differences between 4 and 8 weeks were significant (P<0.05) except the Tb.Th in group A. At different time points, the Tb.Th, Tb.N, and BMD were significantly higher in groups B and C than in group A (P<0.05), and in group C was higher than in group B (P<0.05), showing significant differences between groups. Histological staining showed that the materials of groups B and C were biodegradable, and the osteogenic effect was increased with the increase of P24 concentration.ConclusionP24 peptide can improve the ectopic osteogenesis of CS-TBA hydrogel, and the 10% concentration is more effective.

    Release date:2018-09-03 10:13 Export PDF Favorites Scan
  • Research progress on active surveillance of low-risk papillary thyroid microcarcinoma

    ObjectiveTo summarize the latest research progress in active surveillance of low-risk papillary thyroid microcarcinoma at home and abroad, and provide some reference for future clinical work. MethodRetrieved and reviewed relevant literatures about prospective studies on active surveillance of papillary thyroid microcarcinoma.ResultsIn recent years, the incidence of papillary thyroid microcarcinoma had increased sharply, but most of the biological activities were inert, tumor-specific mortality was very low, and only a few had progressed. For patients with papillary thyroid microcarcinoma, surgery was a safe and effective treatment method, but due to changes in the epidemiological characteristics of the disease, people were reconsidering whether there was overtreatment in patients without high-risk characteristics. Expert consensus and guidelines no matter at home or abroad mentioned that active monitoring can be considered as an alternative to surgery. For suitable patients, active monitoring might be a better choice.ConclusionsActive surveillance for low-risk papillary thyroid microcarcinoma is basically considered to be a safe and feasible treatment option, but large numbers of clinical trials are still needed to provide evidence for the conversion of conventional clinical treatment models. In the future, by more accurately assessing the tumor progression of patients with low-risk papillary thyroid microcarcinoma, active surveillance is promising to alternate surgical treatments.

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  • EXPERIMENTAL STUDY ON SMALL INTERFERING RNA SILENCING EXPRESSION OF TUMOR NECROSIS FACTOR α AND INHIBITING OSTEOLYSIS

    Objective To investigate the possibility of gene therapy of osteolysis around artificial joint prosthesis by constructing the recombinant adenovirus which can silence tumor necrosis factor α (TNF-α). Methods The primer of small interfering RNA (siRNA) coding sequence of silent TNF-α was designed and amplified, and then RAPAD adenovirus packaging system was used to load the sequence to adenovirus, and the recombinant adenovirus Ad5-TNF-α-siRNA-CMVeGFP which lacked both E1 and E3 regions was constructed. Then 64 female BABL/C mice (weighing, 20-25 g) were randomly divided into 4 groups (n=16): blank control (group A), positive control (group B), simple adenovirus (group C), and treatment group (group D). The prosthetic-model was established in group A, and the prosthetic-loosening-model in groups B, C, and D. At 2 weeks after modeling, PBS solution was injected first, and then the same solution was injected 24 hours later in group A; titanium particle solution was injected, and then PBS solution, Ad5 E1-CMVeGFP (1 × 109 PFU/mL), and Ad5-TNF-α-siRNA-CMVeGFP (1 × 109 PFU/mL) were injected, respectively in groups B, C, and D 24 hours later, every 2 weeks over a 10-week period. The general condition of mice was observed after operation. The tissues were harvested for histological observation, and the expression of TNF-α was detected by Western blot at 12 weeks after operation. Results The positive clones were achieved by enzyme digestion and confirmed by DNA sequencing after loading the target genes into adenovirus vector, and then HEK293 cells were successfully transfected by recombinant adenovirus Ad5-TNF-α-siRNA-CMVeGFP. All mice survived to the completion of the experiment. Histological observation showed that there were few inflammatory cells and osteoclasts in group A, with a good bone formation; there were a large number of inflammatory cells and osteoclasts in groups B and C, with obvious bone destruction; inflammatory cells and osteoclasts in group D was less than those in groups B and C, with no obvious bone destruction. Significant difference was found in the limiting membrane thickness and the number of osteoclasts (group A lt; group D lt; group B lt; group C, P lt; 0.05). Western blot showed that the TNF-α expression levels were 0.235 ± 0.022, 0.561 ± 0.031, 0.731 ± 0.037, and 0.329 ± 0.025 in groups A, B, C, and D respectively, showing significant difference among 4 groups (P lt; 0.05). Conclusion The recombinant adenovirus for silencing TNF-α is successfully constructed, which can effectively inhibit osteolysis by silencing TNF-α expression in the tissues around prosthesis in mice.

    Release date:2016-08-31 04:08 Export PDF Favorites Scan
  • A PROSPECTIVE STUDY ON WOUND-HEALING HYDROGEL IN TREATING CHRONIC VENOUS ULCER OF LOWER EXTREMITIES

    【Abstract】 Objective To study the outcome of wound-heal ing hydrogel in treating chronic venous ulcer of lowerextremities so as to find a new therapy. Methods From April 2007 to September 2007, 60 patients with chronic venous ulcer of lower extremities were randomly assigned to wound-heal ing hydrogel group (group A, 30 cases) and control group (normal sal ine, group B, 30 cases). In group A, there were 24 males and 6 females, aging (57.3 ± 6.8) years; the disease course was (2.9 ± 0.7) years; and the ulcer area was (3.4 ± 0.6) cm2. In group B, there were 20 males and 10 females, aging (60.1 ± 7.4) years; the disease course was (3.3 ± 0.9) years; and the ulcer area was (3.1 ± 0.4) cm2. There were no differences in age, area of ulcer and course of disease between two groups (P gt; 0.05). The area of ulcer was measured every week after the treatment, and the effect of treatmentwas evaluated after 15 days. Results The ulcer area of 7 days and 14 days after treatment was (2.6 ± 0.7) and (1.1 ± 0.2) cm2 in group A, and (2.8 ± 0.6) and (2.3 ± 0.7) cm2 in group B, respectively; showing no statistically significant differences 7 days after treatment (P gt; 0.05), and showing statistically significant difference 14 days after treatment between two groups (P lt; 0.05).The average heal ing time was (12.0 ± 1.7) days in group A, and (31.0 ± 2.9) days in group B, respectively, showing statisticallysignificant difference (P lt; 0.01). The results were excellent, good, fair and poor in 16, 9, 4 and 1 of group A , and were in 3, 9, 14 and 4 of group B, respectively; showing statistically significant difference (P lt; 0.01). Conclusion Wound-heal ing hydrogel is effective in treating chronic venous ulcer of lower extremities.

    Release date:2016-09-01 09:10 Export PDF Favorites Scan
  • DEVELOPMENT OF CHITOSAN/POLYETHYLENE GLYCOLS-SUCCINATE MITOMYCIN C FILM DRUG DELIVERYSYSTEM AND RELEASING CHARACTER IN VITRO

    To develop the chitosan /polyethylene glycols succinate (CH/PEG-SA) mitomycin C (MMC) film drug del ivery system and its release effect in vitro. Methods MMC loading in composite films was determined using a UV-visible spectrophotometer. Freeze-dried films (90 mg) were immersed in 1 mL PBS buffer (pH 7.4). The concentrations ofMMC releasing in vitro were calculated refer to the standard curve of relationship between the concentrations of MMC and the value of UV-visible spectrophotometer. The curve of the concentrations of MMC releasing from the films in vitro was drawn at different time. The relationship between the films, structure and the drug releasing was revealed. Results The films showed swell ing without brittleness. The equation of Linear Regression was y=0.593x3– 2.563x2 +25.944x – 0.236 (R2=1.000). The film had a good drug del ivery capabil ity. The samples weighing 20 mg were soaked into the l iquid of PBS, the releasing concentrations of MMC were 14.961 6 μg/mL at 12 days, 14.482 4 μg/mL at 18 days and 11.409 2 μg/mL at 32 days, which was higher than ID50 of MMC (10.471 3 μg/L) to fibroblast. Then MMC was released at a low concentration. The releasing concentrations of MMC was 0.179 3 μg/ mL at 60 days until being del ivered completely. Conclusion The flexibil ity is enhanced , and the mechanical function is improved, so that there is better nature of membrane. The initial burst is avoided more effectively, and the drug releasing would be maintained for a certain time.

    Release date:2016-09-01 09:12 Export PDF Favorites Scan
  • Research progress on neuroinflammatory mechanisms of blood-brain barrier damage and repair in ischemic stroke

    Ischemic stroke (IS) is one of the important diseases threatening human health. The occurrence and development of IS can trigger a series of complex pathophysiological changes, including damage to the blood-brain barrier, ion imbalance, oxidative stress, mitochondrial damage, which ultimately lead to the apoptosis and necrosis of nerve cells in the ischemic area. Impaired blood-brain barrier is a key factor for cerebral edema, hemorrhagic transformation and poor prognosis in patients with IS, and neuroinflammatory response plays an important role in the damage and repair of the blood-brain barrier. This article mainly focuses on the neuroinflammatory response mediated by glial cells, pro-inflammatory cytokines and matrix metalloproteinases and the related mechanisms of IS blood-brain barrier damage and repair, in order to provide new directions for the treatment of IS.

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