To investigate the effect and mechanism of intravascular brachytherapy with 192 Ir on expression of type I collagen after angioplasty. Restenosis model of domestic miniswine was employed.After angioplasty, the iliac arteries were randomized to brachytherapy group ( n =6) , which were treated with 20 25Gy of 192 Ir, and control group ( n =18). The target vessels were harvested at the 12 th week and the 24 th week after angioplasty. Immunohistochemistry and in situ hybridization were used to detect proteins of type I collagen, metalloproteinase 1 (MMP 1) and its tissue inhibitor (TIMP 1), and mRNA expression of type I collagen. The results showed that the protein and mRNA of type I collagen, and the ratios of TIMP 1/MMP 1 were lower in brachytherapy group than in control group. The peak of mRNA expression of type I collagen was at the 24 th week in control group and at the 12 th week in brachytherapy group, respectively. It suggested that intravascular brachytherapy with 192 Ir affects the metabolism of extracellular matrix by inhibiting the synthesis of type I collagen and regulating the activities of MMP 1 and TIMP 1.

Operation navigation is one of the important compositions of minimally invasive surgery technology. Operation navigation is one of the important compositions of minimally invasive surgery technology. It is a hotspot studied at home and abroad. The navigation products have been studied and applied at abroad, but they are still exploring at home.The article introduces the concept, composition and application of the operation navigation system briefly. Directing against the difficulty of interlocking intramedullary nails location in femoral shaft fracture operation, the fact that the necessity of using operation navigation system is expounded. And the feasibility of using femoral shaft fracture operation navigation and the relevant researches are discussed. It is doable for the navigation system to be used in fixing interlocking intramedulary nail in our laboratory.

【Objective】 To study the relationship of pathologic changes and serologic markers of fibrosis in patients with viral hepatitis. 【Me thods】 Liver s pecimens were obtained by percutaneous needle biopsy under color Doppler ultras ound guidance in 299 patients with viral hepatitis. The specimens were stained b y hematoxylin and eosin (HE), Gordon and Sweet's reticulum methods (RT), in orde r to determine the degree and the stage of pathologic changes with microscopy. H yaluronic acid(HA), collagen type Ⅳ(Ⅳ-C) and human precollagen type Ⅲ（HPCⅢ ）as serum fibrous markers were detected by radioimmunoassay. 【Results】 The se rum levels serologic markers were slightly increased in 97 patients with mild ch ronic hepatitis, moderately increased in 126 patients with moderate chronic hepa titis, and significantly increased in 29 severe cases and 47 subjects with cirrh osis. Both the grade of inflammatory activity and the stage of fibrosis were clo sely related to the levels of serum fibrous markers. 【Conclusion】 Chronic vira l hepatitis pathologic feature and levels of serum markers of fibrosis change al ong with clinical process of patients. The combination of liver biopsy and detec tion of serum markers of fibrosis might be highly valuable for the diagnosis.

Objective To explore the optimum flow shear stress and mass transport for the construction of tissue-engineered bone.Methods The β-tricalcium phosphate (β-TCP) scaffolds seeded with human bone marrow-derived mesenchymal stem cells (HBMMSCs) were cultured in perfusion bioreactor.When the same flow rate was applied,the flow shear stress was separately 1×,2× and 3×.When the same flow shear stress was applied,the flow rates were separately 3 ml/min,6 ml/min and 9 ml/min.Cell proliferation was measured by MTT method.The construction of tissue-engineered bone was evaluated by measuring alkaline phosphatase (AKP) activity,secretion of osteopontin (OP) and osteocalcin (OC),and the mineralization of extracellular matrix (ECM).The flow shear stress and the mass transport were obtained using computational fluid dynamics.Results When the flow rate was same,the most cell proliferation was found in 2× group.The AKP activity and secretion of OC was higher in 2× and 3× groups than in those in 1× group.After 28days,the highest amount of mineralization of ECM was found in 3× group.When the flow shear stress was same,the AKP activity was highest in 6 ml/min group.After 28 days,secretion of OC and formation of mineralized ECM was highest in 3 ml/min group.When the flow rate was same,the flow shear stress was separately 0.004-0.007 Pa,0.009-0.013 Pa and 0.013-0.018 Pa.When the flow shear stress was same,the flow rate was separately 0.267-0.384 mm/s,0.521-0.765 mm/s and 0.765-1.177 mm/s.Conclusion When the tissue-engineered bone was constructed,0.013-0.018 Pa flow shear stress and 0.267-0.384 mm/s mass transport velocity could improve the construction of the tissue-engineered bone in vitro.

Objective To investigate the feasibility and the efficacy of ultrasound in promoting PLGA nanoparticle-mediated gene transfection in vivo.Methods Prostate cancer cell line PC-3 was used to generate xenografts in nude mice for gene transfection experiment in vivo.GFP plasmid was encapsulated in PLGA-based nanoparticles.Nanoparticles were injected into tumors locally.Two hours later,xenografts were exposed to ultrasound.Xenograft tissues were harvested in different time points to assess the efficiency of gene expression with regard to different parameters of ultrasound. Results PLGA nanoparticle-encapsulated GFP plasmids were readily transfected to PC-3 cells in vivo.A large number of GFP expressing cells were observed after exposed to ultrasound with 1.0 MHz 50% duty factor continuous wave.In comparison,ultrasound exposure with 40% duty factor pulse wave in vivo had low efficacy in terms of GFP expression.No animal death was noticed due to ultrasound exposure.Conclusions Ultrasound exposure can enhance the release of plasmid DNA content delivered by PLGA nanoparticles in vivo,local exposure to ultrasound wave would be used in conjunction with PLGA nanoparticle-mediated targeted delivery to the tissue or organ of interest.

A case of a 3-year-old child suffered with severe crush injury to the right forearm and right hand on June, 2017. A comprehensive treatment was conducted with limb salvage, free flap repair and the repair of nerve, vessel and tendon for functional reconstructions followed by rehabilitation therapies. The function and appearance of the injured limb and hand recovered well 3 years after surgery.

Tissue-engineering bone with porous ,betatricalcium phosphate (3-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defects was investigated. 10-15 ml bone marrow aspirates were harvested from the iliac crest of sheep, and enriched for MSC by density gradient centrifugation over a Percoll cushion (1. 073 g/ml). After cultured and proliferated, tissue-engineering bones were constructed with these,cellS seeded onto porous f-TCP, and then the constructs were implanted in 8 sheep left metatarsus defect (25 mm in length) as experimental group. Porous ,-TCP only were implanted to bridge same size and position defects in 8 sheep as control group, and 25 mm segmental bone defects of left metatarsus were left empty in 4 sheep as blank group. Sheep were sacrificed on the 6th, 12th, and 24th week postoperatively and the implants samples were examined by radiograph, histology, and biomechanical test. The 4 sheep in blank group were sacrificed on the 24th week postoperatively. The results showed that new bone tissues were observed either radiographic or histologically at the defects of experimental group as early as 6th week postoperatively, but not in control group, and osteoid tissue, woven bone and lamellar bone occurred earlier than in control group in which the bone defects were repaired in "creep substitution" way, because of the new bone formed in direct manner without progression through a cartilaginous intermediate. At the 24th week, radiographs and biomechanical test revealed an almost complete repair of the defect of experimental group, only partly in control group. The bone defects in blank group were non-healing at the 24th week. It was concluded that engineering bones constructed with porous -TCP and autologous MSC were capable of repairing segmental bone defects in sheep metatarsus beyond "creep substitution" way and making it healed earlier. Porous ,-TCP being constituted with autologous MSC may be a good option in healing critical segmental bone defects in clinical practice and provide insight for future clinical repair of segmental defect.
Bone Marrow Cells/cytology ; Calcium Phosphates/*pharmacology ; Cells, Cultured ; Fractures, Bone/*therapy ; Implants, Experimental ; Mesenchymal Stem Cells/*cytology ; Metatarsus/*injuries ; Porosity ; Sheep ; Tissue Engineering

Animals ; Drosophila Proteins ; Humans ; Lipopolysaccharides ; pharmacology ; Membrane Glycoproteins ; metabolism ; physiology ; Receptors, Cell Surface ; metabolism ; physiology ; Signal Transduction ; Toll-Like Receptor 4 ; Toll-Like Receptors

Tissue-engineering bone with porous β-tricalcium phosphate (β-TCP) ceramic and autologous bone marrow mesenchymal stem cells (MSC) was constructed and the effect of this composite on healing of segmental bone defects was investigated. 10-15 ml bone marrow aspirates were harvested from the iliac crestof sheep, and enriched for MSC by density gradient centrifugation over a Percoll cushion (1. 073 g/ml). After cultured and proliferated, tissue-engineering bones were constructed with these cells seeded onto porous β-TCP, and then the constructs were implanted in 8 sheep left metatarsus defect (25 mm in length) as experimental group. Porous β-TCP only were implanted to bridge same size and position defects in 8 sheep as control group, and 25 mm segmental bone defects of left metatarsus were left empty in 4 sheep as blank group. Sheep were sacrificed on the 6th, 12th, and 24th week postoperatively and the implants samples were examined by radiograph, histology, and biomechanical test. The 4 sheep in blank group were sacrificed on the 24th week postoperatively. The results showed that new bone tissues were observed either radiographic or histologically at the defects of experimental group as early as 6th week postoperatively, but not in control group, and osteoid tissue, woven bone and lamellar bone occurred earlier than in control group in which the bone defects were repaired in "creep substitution" way, because of the new bone formed in direct manner without progression through a cartilaginous intermediate. At the 24th week, radiographs and biomechanical test revealed an almost complete repair of the defect of experimental group, only partly in control group. The bone defects in blank group were non-healing at the 24th week. It was concluded that engineering bones constructed with porous β-TCP and autologous MSC were capable of repairing segmental bone defects in sheep metatarsus beyond "creep substitution" way and making it healed earlier. Porous β-TCP being constituted with autologous MSC may be a good option in healing critical segmental bonedefects in clinical practice and provide insight for future clinical repair of segmental defect.

Objective: To analyze the spatial temporal distribution characteristics of tuberculosis among high school students at county levels in Gansu Province from 2018 to 2022,so as to provide a scientific basis for tuberculosis prevention and control in schools. Methods: Tuberculosis data from high school students in counties (districts) reported in Gansu Province from 2018 to 2022 was collected from the Tuberculosis Information Management System and Infectious Disease Information Reporting System of the Chinese Disease Prevention and Control Information Management System. Demographic data of high school students in counties (districts) came from the General Management System of the Chinese Disease Prevention and Control Information Management System, and the spatial clustering of the reported incidence rate of pulmonary tuberculosis among high school students in Gansu Province in the past five years was analyzed using the methods of global spatial autocorrelation (Moran s I) and local indicators of spatial audocorrelation(LISA). Results: A total of 41 885 pulmonary tuberculosis cases were reported in various counties of Gansu Province From 2018 to 2022, with an average reported incidence rate of 32.81/100 000. During the same period, 1 170 high school students cases were reported, with an average reported incidence rate of 13.72/100 000. With the exception of 2020, the reported incidence rate of pulmonary tuberculosis among high school students was non random distribution in other 4 years, showed a moderate intensity of spatial clustering. From 2018 to 2022, most counties in Gansu Province reported that the incidence rate of pulmonary tuberculosis among high school students was 10.00/100 000 or below, the counties with reported incidence rate >40.00/100 000 were mainly distributed in Luqu County, Maqu County, Diebu County, Hezuo City, Xiahe County of Gannan Prefecture, Gangu County and Wushan County of Tianshui Prefecture, Wenxian County and Kangxian County of Longnan Prefecture, Huachi County of Pingliang Prefecture, Huanxian County of Qingyang Prefecture. The number of counties where the reported incidence rate of tuberculosis among high school students more than 30.00/100 000 gradually decreased from 2018 to 2022. In the past five years, the reported incidence rate of tuberculosis among high school students in all counties of Gannan Prefecture remained above 40.00/ 100 000 . The LISA analysis results showed that the high incidence areas were mainly concentrated in Gannan Prefecture. Conclusions The epidemic situation of pulmonary tuberculosis among high school students in Gansu province from 2018 to 2022 is still a serious condition, showing the characteristics of unbalanced regional distribution. The reported incidence rate shows a strong spatial clustering, and the hot spots are concentrated in the counties (districts) of Gannan prefecture in Gansu Province.