[Objective]To prepare a cartilage acellular matrix scaffold and to explore its feasibility in cartilage tissue engineering. [Methods]Microparticles about 100 ?m~154 ?m were prepared after calf cartilage physically shattered and experienced gradient centrifugation,and then treated by a modified Courtman's four-step method which was improved to produce acellular cartilage matrix.After this treatment the microparticles were made into 3% suspension which was placed into moulds.With the freeze-drying method,3-D cartilage acellular matrix (CACM) was prepared.The scaffolds were cross-linked by a neotype crosslinking agent genepin for 48h,and then placed into glycine solution server times for removing redundant genepin.The freeze-drying method was used to prepare CACM.The scaffolds were investigated by gross observation,histological staining (haematoxylin-eosin,toluidine blue) ,scanning electron microscope (SEM) observation and porosity measurement,water absorption rate and degradation rate analysis.After being cultivated for ten days,bone marrow stranal cells (BMSCs) of rabbit were seeded into the scaffold.MTT test and SEM were done to assess the growth and proliferation of BMSCs.[Results]Gross observation showed the scaffolds had a loosely porous and dark blue appearance after being cross-linked by genepin.The histological staining (haematoxylin-eosin,toluidine blue staining) showed that there were no chondrocyte fragments in the scaffold.The CACM scaffold had 90% porosity,(1314?337) % water absorption rate,and (13.69?7.3)% or (25.99?8.9) % degradation rate at 2 or 4 weeks.MTT test showed that BMSCs grew well in the 3-D CACM scaffolds of logarithmic trend,supporting that the scaffolds had no cytotoxic effect on BMSCs.SEM micrographs indicated that the scaffolds were porous and the cells covered the scaffolds firmly with cell processes.[Conclusion]The improved Courtman's four-step method makes a more thoroughly acellular scaffold.The 3-D CACM scaffold retains most of extracelluar matrix.After being cross-linked by genepin,the 3-D CACM scaffold has good biocompatibility and degradation rate of the scaffolds is decreased,which makes it a suitable carrier for cartilage tissue engineering.

Female ; Foreign Bodies ; Humans ; Middle Aged ; Nasal Cavity ; pathology ; Paranasal Sinuses ; pathology

Animal Feed ; Animals ; Gynostemma ; Male ; Plant Extracts ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Swimming

The amount of the research-oriented graduates is increasing in affiliated hospitals of medical universities.To create an effective training model can not only help students to succeed but also contribute great to the research level of hospitals.In this study,we summarized our experience,such as individualized teaching,the unity of thinking and performing,words and deeds as well as unity of clinic and research on the formation of research ideas,attitudes and styles.Based on our experiences we hope to provide meaningful methods for the training of medical graduates.

Objective To observe the clinical efficacy of naloxone plus aminophylline in the treatment of children with acute respiratory failure.Methods 72 patients with acute respiratory failure were randomly divided into the study group and the control group.36 cases in the study group were given naloxone plus aminophylline therapy, 36 cases of the control group received conventional therapy.And the clinical efficacy was compared.Results The total effective rate of the study group was 91.67%,which was significantly higher than 66.67% of the control group (χ2 =6.82,P <0.05).In the comparison of the effect of improving blood indicators,arterial blood pressure of the study group was (67.51 ±4.11)mmHg,which was significantly higher than (61.03 ±4.08)mmHg in the control group (t =2.64,P <0.05).The oxygen saturation of the study group was (93.55 ±8.05)%,which was significantly higher than (79.62 ±10.22)% of the control group (t =2.29,P <0.05).The arterial carbon dioxide partial pres-sure of the study group was (69.03 ±5.71)mmHg,which was also higher than (61.52 ±4.09)mmHg of the control group (t =2.22,P <0.05).The incidence rate of adverse reactions of study group was 2.78%,which was lower than 22.22% in the control group (χ2 =6.22,P <0.05).Conclusion Naloxone plus aminophy -lline used in children with acute respiratory failure obtain the desired therapeutic effect,not only can effectively improve blood indicators of children,and without significant adverse reactions,drug safety is high,it is worthy of promoting.

[Objective]To compare the purity and extraction rate of four purecollagen type I products prepared from various biomaterials by a limited enzyme digestion method for the use in tissue engineering.[Method]Bovine cortical bone, bovine achilles tendon, porcine achilles tendon and porcine skin were splitted into pieces of 0.2-0.5 mm. After being immersed in glacial acetic acid, they were extracted with pepsin. Then the crude products were dissolved, centrifuged, dialyzed and freeze drying to prepare pure collagen type I. The final products were confirmed by absorbance, amino acid analysis and'SDS-PAGE electrophoresis comparing them with the products of Sigma Company.[Result]The wave length of maximum absorbance of the final products was 230 nm, and the amino acid analysis and SDS-PAGE electrophoresis confirmed that the final products were collagen type I. The purity of product extracted from bovine cortical bone was the highest (96.12%) and higher than that from Sigma Company. The extraction rate of bovine achilles tendon collagen was the highest (75.34%).[Conclusion]Collagen type I of higher purity and higher extraction rate can be prepared using a limited enzyme digestion method.And the product from bovine cortical bone is better than the others,which has a promising prospect.

[Objective]To investigate the technical advantages of micro-CT in the research of three dimensional structure of bone tissues over histological section technology. [Method]Different kinds of bone tissue related specimen were observed by micro-CT and histological section,respectively.The diversity of the sample treatments,result expressions and test data were compared.[Result]Micro-CT showed great advantages in displaying three dimensional structure characteristics of bone tissues.Both quantity and quality changes of bone tissues could be precisely determined by micro-CT which was much better than histological section technology.However,histology showed great advantages in displaying the cell figures,growth and differentiation.[Conclusion]Micro-CT provides a novel test method for both sample treatments and result expressions.Compound with histological technology,micro-CT can display the appearance and structure of bone tissues more sufficiently.

[Objective]To observe the biological properties of a novel collagen/hydroxyapatite composite scaffold in vitro and to evaluate the possibility of application being used in tissue engineering for osteochondral repair.[Method]The scaffolds were constructed of collagen I and hydroxyapatite.The pore size and interpores of the scaffold were observed by scanning electronmicroscopy(SEM).The porosity was measured by liquid displacement method.Rabbit bone marrow stromal cells(BMSCs) were isolated and amplified,then inoculated onto the scaffold.By SEM scanning,the condition of the cells adhering onto the scaffold was observed.The proliferation of the cells on the scaffolds was examined using MTT method,and the growth curve was drawn.[Result]The scaffold possessed high porosity and proper pore size.The pore diameter of the collagen layer was about 90?m,the pore diameter of the HA layer was about 120?m,and the overall porosity of the composite scaffold was 75%.The proliferation of the cells on the scaffold was good.[Conclusion]The novel collagen/hydroxyapatite composite scaffold possesses desirable pore structure and good biocompatibility,and it can be used in tissue engineering for osteochondral repair.

0.05).[Conclusion]The osteochondral scaffold of the collagenⅠ-sodium hyaluronate-fbrin glue tri-copolymer scaffold bonding with antigen-extracted bovine cancellous bone has an appropriate structure and a good biocompatibility,which makes it a useful scaffold in the osteochondral tissue engineering.

Objective To investigate the prevalence of the occupational hazard of organic solvent and noise in printing and Methods record medium production enterprises in Longgang District of Shenzhen City. A total of 56 printing and record medium production enterprises were selected as the study subjects by judgmental sampling method to analyze the worksite Results survey of occupational health and the key occupational hazard factors. There were 256 organic solvent samples ， detected in 56 enterprises which included a total of 148 terms and 1 358 categories of volatile constituents. The top three （ ）， - （ ） （ ） volatile constituents were toluene 35.5% n hexane 25.7% and methanol 23.8% . The top three detected samples of the （ ， ， ， ， - ， ，- ， eight key chemical occupational hazard factors benzene toluene xylene ethylbenzene n hexane 1 2 dichloroethane ） ， - ， trichloroethylene and chloroform were toluene n hexane and ethylbenzene. In the workplace air toluene was the most risk ， factor of occupational hazard factors in enterprise and in sample detection while no trichloromethane was detected. The toluene in workplace air was found to exceed the national standard with the rate of 2.6%. It showed that 27.9% of the work sites were found occupational noise hazard which was over national standard in the 10 key work sites. Only 64.3% and 57.1% enterprises - performed occupational hazard factors detection and occupational health examination. Both none or invalid toxicant proof - facilities accounted for 33.9% of the enterprises. Both none or invalid noise proof facilities accounted for 78.6% of the Conclusion ， - enterprises. The occupational hazards factor of toluene n hexane and noise were serious in printing and record ， medium production enterprises in Longgang District of Shenzhen City and the occupational health management was imperfect. The occupational regulation should be enhanced in this industry.