Objective To investigate the incidence rate, molecular epidemiology and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) infection. Methods A total of 119 Staphylococcus aureus strains isolated from January 2016 to December 2020 in general surgery of this hospital were collected retrospectively and divided into MRSA group and methicillin-sensitive Staphylococcus aureus group according to whether or not resistant to oxacillin. The clinical data of all patients infected with Staphylococcus aureus and drug sensitivity of Staphylococcus aureus were collected. Molecular typing was performed by multilocus sequence typing (MLST), resistance gene, virulence gene and biofilm gene were detected by polymerase chain reaction (PCR) method, and a case-control study was used to identify risk factors for MRSA infection. ResultsThe detection rate of MRSA was 57.98% (69/119), mainly was from pus specimens (80.67%, 96/119). The results of MLST showed that the dominant clone types were ST88 (37.68%, 26/69), ST951 (27.54%, 19/69) and ST59 (18.84%, 13/69). The results of PCR showed that the detection rates of mecA, mecC, Aac (6′ )/Aph (2′ ′ ), Aph (3)-Ⅲ, ant (4′ )- Ⅰ a, tetM, qnrA, panton-valentine leukocidin, fibronectin-binding protein A, staphylococcal enterotoxin A, staphylococcal enterotoxin B, α-hemolysins, intracellular adhesion A, staphylococcal accessory regulators A, and fibronectin-binding protein B in 69 strains of MRSA were 100%, 0.00%, 27.54%, 34.78%, 18.84%, 14.49%, 1.45%, 8.70%, 98.55%, 11.59%, 91.30%, 94.20%, 92.75%, 97.10% and 86.96%, respectively. Multivariate analysis showed that hospital transfer, wound infection, catheter related infection, drainage tube and history of cephalosporin using were risk factors for MRSA infection. ConclusionsThe detection rate of MRSA in general surgery of this hospital is high. ST88 is the most common clone type. The carrying rates of resistant-, virulence- and biofilm-related genes are high. Hospital transfer, wound infection, drainage tube, history of cephalosporin using etc. are high risk factors for MRSA infection. It is advised that invasive operation should be reduced, antibiotics should be used rationally, hand hygiene should be paid attention to, environmental sanitation disinfection should be carried out regularly, and the monitoring of MRSA bacteria should be strengthened, so as to reduce and control the infection and spread of MRSA.
ObjectiveTo study the feasibility of preparation of the individualized femoral prosthesis through computer assisted design and electron beammelting rapid prototyping (EBM-RP) metal three-dimensional (3D) printing technology. MethodsOne adult male left femur specimen was used for scanning with 64-slice spiral CT; tomographic image data were imported into Mimics15.0 software to reconstruct femoral 3D model, then the 3D model of individualized femoral prosthesis was designed through UG8.0 software. Finally the 3D model data were imported into EBM-RP metal 3D printer to print the individualized sleeve. ResultsAccording to the 3D model of individualized prosthesis, customized sleeve was successfully prepared through the EBM-RP metal 3D printing technology, assembled with the standard handle component of SR modular femoral prosthesis to make the individualized femoral prosthesis. ConclusionCustomized femoral prosthesis accurately matching with metaphyseal cavity can be designed through the thin slice CT scanning and computer assisted design technology. Titanium alloy personalized prosthesis with complex 3D shape, pore surface, and good matching with metaphyseal cavity can be manufactured by the technology of EBM-RP metal 3D printing, and the technology has convenient, rapid, and accurate advantages.
3D printing technology has a promising prospect of medical use and clinical value, and may play an important role in the field of thoracic and cardiovascular surgery, such as preoperative diagnosis, surgical planning, surgical approach alternatives and organ replacement. This review focuses on the development of 3D printing technology in recent years and its use and prospect in the field of thoracic and cardiovascular surgery including surgical teaching and simulation, personalized prosthesis implantation, and artificial organ transplantation.
Objective To investigate the methods of establishing 3-dimensional skull model using electron beam CT(EBCT) data rapid prototyping technique, andto discuss its application in repairing crainomaxillofacial trauma. Methods The data were obtained by EBCTcontinuous volumetric scanning with 1.0 mm slice at thickness. The data were transferred to workstation for 3-dimensional surface reconstruction by computeraided design software and the images were saved as STL file. The data can be usedto control a laser rapid-prototyping device(AFS-320QZ) to construct geometricmodel. The material for the model construction is a kind of laser-sensitive resinpower, which will become a mass when scanned by laser beam .The design and simulation of operation can be done on the model. The image data were transferred to the device slice by slice. Thus a geometric model is constructed according to the image data by repeating this process. Preoperative analysis, surgery simulation and implant of bone defect could be done on this computer-aided manufacture d3D model. One case of craniomaxillofacial bone defect resulting from trauma wasreconstructed with this method. The EBCT scanning showed that the defect area was 4 cm×6 cm. The nose was flat and deviated to left. Results The -3dimensional -skull was reconstructed with EBCT data and rapid prototyping technique. The model can display the structure of 3-dimenstional anatomyand their relationship.The prefabricated implant by 3-dimensional model was well-matched with defect .The deformities of flat and deviated nose were corrected. The clinical result wassatisfactory after a follow-up of 17 months. Conclusion The 3-dimensional model of skull can replicate the prototype of disease and play an important role in the diagnosis and simulation of operation for repairing craniomaxillofacial trauma.
Mycobacterium tuberculosis is the causative agent of human tuberculosis. Through the genotyping of Mycobacterium tuberculosis, we can find the epidemic situation and characteristics of tuberculosis in time, analyze the transmission chain between patients in different jurisdictions, and formulate effective intervention measures in time, to provide a strong basis for clinical diagnosis and treatment. At present, several genotyping techniques for Mycobacterium tuberculosis have their advantages and disadvantages in application. This article reviews the genotyping technology, population genetics and genotyping naming rules of Mycobacterium tuberculosis.
Objective To design a new custom-made artificial semi-knee joint based on rapid prototyping(RP) technique and to explore a method to solve necroses of allocartilage in hemi-joint allotransplantation. Methods Based on the extracted 3D contour image of the articular cartilage of femoral condyle, the custom-made artificial semi-knee joint was designed with Surfacer 9.0 image processingsoftware. The artificial semi-knee joint design used the femoral condylar 3D contour of the patient as the outer face and the subchondral bone 3D contour of allograft bone as inner face. One dado for medullary nailand two for special designing cages which were used to fix the cartilage into the allograft were added on the inner face. After being converted into RP data format, the computerassisted design was imported into the LPS600 rapid prototyping machine, and the prototype was achieved. Furthermore, the prototype could be modified by hand according to the design. Then the RP model was used as a positive mould to build up a silica gel negativemould, and the negative mould was sent to the factory to manufacture Ti-6Al-4V alloy articular cartilage through ordinary mould-melted founding process. Finally, the whole metal cartilage was completed after melting two special cages on it andpolishing it. Results A new custom-made artificial semi-knee joint was made ad used to treat a 14-year old patient. The custom-made artificial semi-knee joint and the subchondral bone were a perfect match. The operative result was satisfactory. The patient could walk 5 weeks after operation. The bone healing of the auto-bone and allo-bone was achieved 6 months later. A follow-up period lasting 1 yearshowed that the knee joint played a good function. Conclusion The artificial semi-knee joint is a good match for the allograft boneand a good idea to solve necroses of allocartilage in hemijoint allotransplantation.
Objective To introduce the recent advances of the application of computer technology in tissue engineering. Methods The recent original articlesrelated to computer technology, medical image technology, computer-aided design, the advanced manufacture technology were summarized and systematically analyzed.Results Computer-aided tissue engineering is a new fieldon tissue engineering. It is the future direction of tissue engineering study. This article reviews recent development of medical CT/MRI scanning, three-dimensional reconstruction, anatomical modeling, computeraided design, computer-aided manufacturing, rapid prototyping， RP manufacturing of tissue engineering scaffolds and computeraided implantation.Conclusion Computer-aided tissue engineering can be used in scaffolds design and fabrication, computer-aided artificial tissue implantation. It is a new field on tissue engineering.
Objective To build up a new contour and functional reconstruction technique of mandibular defects with rapid prototyping and reverse engineering technique. Methods From April 2002 to August 2004, 4 cases of mandibular defects due to resection of large mandible lesion were treated. Of 4 patients, there were 3 females and 1 male, with an age range of 21-42 years, which underwent secondary operation and presented a deviation as mandibular movement. The openingmouth extent was 1.8-2.5 cm(2.2 cm on average). The data of defects area were renewed withMimics and Geomagic Studio software; and the titanium reconstructive frame was designed and manufactured with rapid prototyping technigue. Defect were reconstructed by using CT digital data of patients. Results The CT data could be used by image software directly. The implant design could be completed by computer-aimed design(CAD)/computer-aided manufacture(CAM). The resin model and titanium frame were manufactured accurately by RP technique. Four patients achieved one stage healing. After a follow-up of 3 months to 2 years, largemandibular defect was reconstructed satisfactorily and the opening-mouth extent was 3.03.4 cm(3.2 cm on average). The occluding relation was normal. The implant denture was put on and the mastication function was good in 1 case. Conclusion Individual design and repair of large mandibular defect with CAD/CAM techniques is worth extending application clinically. It is a simple and accurate method.
Objective To explore the hepatic artery variations encountered in laparoscopic pancreaticoduodenectomy (LPD) surgery and its significance. Methods The clinical datas of 26 patients who underwent LPD from January 2020 to January 2023 were retrospectively collected. Preoperative evaluation of hepatic artery variability and its types based on relevant clinical and imaging data, as well as targeted measures taken during surgery, and patients’ prognosis were analyzed. Results According to preoperative abdominal enhanced CT, arterial computer tomography angiography imaging and intraoperative skeletonization of the hepatoduodenal ligament, hepatic artery variation was found in 9 of 26 patients undergoing LPD. The left hepatic artery was substituted in 1 case, the right hepatic artery was substituted in 2 cases, 2 cases were the left accessory hepatic artery, and the common hepatic artery originated from the superior mesenteric artery in 3 cases. There was 1 case, right hepatic artery coming from the abdominal aorta, whose arterial variation was not included in the traditional typing. The variant hepatic artery from superior mesenteric artery was separated by posterior approach during operation, and the variant hepatic artery from left gastric artery was separated by anterior approach during operation. Nine patients with hepatic artery variation recovered well after operation, and no serious complications occurred. Conclusions Various hepatic artery variations during LPD need to be carefully evaluated before surgery. During surgery, it should be determined whether to retain the mutated blood vessel based on its diameter and changes in liver blood flow after occlusion, so that reasonable operation can be performed during the operation to avoid hepatic artery damage.
Objective To compare the differences of chromosome aberration and Rb 1 gene mutation among 3 cloned cells of SO-Rb50 cell line of retinoblastoma. Methods 1.Three cell cloned strains named MC2, MC3, MC4 were isolated from SO-Rb50. 2. Gbanding and karyotype analysis were performed on the llth passage cells of the 3 cell strains.3.All exons and the promoter region of the Rb gene were detected by PCR-SSCP analysis in tumor cell DNA extracted from the 3 cell strains. Results 1.Both numerical and structural chromosomal aberrations could be observed in these 3 cell strains.Several kinds of structural chromosomal aberrations were observed.The chromosome aberrations in the same passage of different cell strains were different.Aberration of chromosome 13 was rare and the aberration feature was different in the 3 cell strains.Five marker chromosomes were identified.M1,t(1;1)qter-p35∷q24-ter could befound in all cell strains.Two of them M4 and M5,have not been reported in SO-Rb50 cell line previously.2.SSCP analysis of exon 24 showed that MC411 and MC3138 had abnormal band. Conclusions The characteristics of heterogeneity of the original tumor cell line SO-Rb50are still kept during a long-term culture in vitro and the cloned strains had dynamic changes during this period.Aberration of chromosome 13 is not the only cause of RB;aberration of chromosome 1,a commom event in some neoplasias as well as in SO-Rb50, plays a meaningful role in the immortalization of this cell line. (Chin J Ocul Fundus Dis, 1999, 15: 146-148)