In June 2016,a disease among the cultured rock carp (Procypris rabaudi) in Yongchuan of Chongqing Municipality occurred.The aim of this study was to investigate biological characteristics and provide reference for Aeromonas veronii identification diagnosis and treatment.Pathogenic bacteria strain YY01 from the dying fishes were examined and isolated.Strain YY01's taxonomic status was identified by observing the morphology,studying the physiological and biochemical characters and sequencing the 16S rRNA and housekeeping gene gyrB.Its pathogenicity was checked by artificial infection experiment and virulence genes.Furthermore,effective medicine was detected by drug sensitivity.The 16S rRNA and gyrB gene sequence of the strain YY01 was more than 99％ homology with that of Aeromonas veronii,suggesting that the pathogen was Aeromonas veronii,which was also identified by the results of biochemical analysis.The LD50 of strain YY01 to rcok carp was 5.06 × 104 CFU/g.Four virulence genes were detected from YY01,including aerolysin (aer),hemolysin (Hly),Outer Membrane Protein Gene A (OmpA) and adhesion (Aha) genes.Antibiotic sensitivity assays showed that among 40 antibiotics tested,22 were sensitive and 11 were resistant.In conclusion,the strain YY01 is identified as Aeromonas veronii and it is proved to have strong pathogenicity.

OBJECTIVEThe super-high-molecular-weight poly-DL-lactic acid (PDLLA), with the molecular weight of 900 kD, is a newly emerging biomaterial and potentially used in the therapy of bone fracture because of its excellent mechanical property. However the biocompatibility of this material has not been reported so far, therefore this experiment was designed to examine whether the super-high-molecular-weight PDLLA was harmful to creatures, when it was implanted in the body of animals for a long period.

METHODSThe material was prepared in small cuboids, with the size of 1.0 mm x 1.5 mm x 2.0 mm, and these blocks were implanted into the masseteric space of SD rats and, the activity of the SD-rats was monitored continuously. The animals were sacrificed in the 3rd, 6th, 9th, 12th months after the operation and, the specimens were taken out from the animals. The examination included anatomical, pathological and haematological methods. The data were analyzed with SPSS 8.0.

RESULTSThe wound healed well after the operation. Super-high-molecular-weight PDLLA degraded 6 months after the implantation. In the 3rd month after the operation, a thin fiber membrane around the materials was formed. In the 6th month, the membrane was much thinner than that in the 3rd month and completely disappeared in the 9th month. The pathological examination showed that slightly inflammatory reaction appeared in the tissue around these blocks in the 3rd month, but the inflammatory reactions were gradually remitted in the following 6th, 9th and 12th months. Further, the haematological examination did not show any abnormity during the 12-month observation period.

CONCLUSIONThe super-high-molecular-weight PDLLA can be degrade when it is implanted into the body of creatures, which proves its good biocompatibility.

Animals ; Biocompatible Materials ; chemistry ; metabolism ; Biodegradation, Environmental ; Bone Substitutes ; Implants, Experimental ; Lactic Acid ; chemistry ; metabolism ; Male ; Mandible ; metabolism ; surgery ; Molecular Weight ; Polyesters ; Polymers ; chemistry ; metabolism ; Rats ; Rats, Sprague-Dawley

Objective:To investigate the application value of mixed reality (MR) technology in reconstruction of soft tissue defect of extremities with free anterolateral thigh flap(ALTF).Methods:From December 2019 to November 2021, a retrospective analysis was performed on 10 patients who had undergone ALTF reconstruction of soft tissue defects in extremities in Department of Orthopaedics, the First People's Hospital of Yunnan Province. Four patients had the defects in hand and 6 patients in foot and ankle. For the 6 patients in emergency surgery, the time from injury to admission was 4.0-15.0 hours, with an average of 7.3 hours. Four patients with soft tissue defects caused by chronic infection and ulcers were given debridement, and the soft tissue defects were reconstructed by flap transfer at the second stage. The defect area were from 8.0 cm×5.0 cm to 22.0 cm×8.0 cm. Preoperatively, 3D bone-vessel-flap model was established based on the lower extremity CTA scans. Intraoperatively, MR technology was used to project the 3D model on the flap donor site to observe the virtual profile of vessel shape in real time, to locate the perforator and the course of the perforator, and observe the consistency between the virtual image and the actual anatomy of the perforator. The appearance, texture and colour of the flap were recorded at the last follow-up. Hand function was evaluated by the total activity movement (TAM), and foot and ankle function was evaluated by the American Orthopaedic Foot and Ankle Society (AOFAS).Results:The position location and course of perforator vessels were reconstructed successfully in all patients before surgery. The MR technology was used to locate the perforator, and the course of the virtual perforator was consistent with the actual anatomy, and the matching reached 100%. The length of vascular pedicle measured before surgery was at 11.02 cm±1.37 cm. And that measured during surgery was at 11.21 cm±1.23 cm ( P=0.748, t=-0.326). The difference was not statistically significant ( P>0.05). The flap area was at 9.0 cm×6.0 cm to 23.0 cm×9.0 cm. The donor site was sutured directly in one stage. All patients were entered postoperative followed-up for 1 to 24 months, with an average of 13.5 months. All the flaps survived after surgery. The flap with good appearance, colour and texture, and only one linear scar was left in the donor site. According to the TAM of the hand function, 3 cases were excellent and 1 was fair. Foot and ankle function were evaluated according to the AOFAS, 5 cases were in excellent and 1 was good. Conclusion:MR technology applied to the surgery of ALTF can locate the course of the flap vessels in real time, guide the operation, improve the operation efficiency and reduce the risk in surgery.