In order to establish a stable in vitro culture platform for chicken small intestine three-dimensional (3D) organoids, in this study, crypt cells were collected from the small intestine of 18-day-old embryos of AA broilers. On the basis of the L-WRN conditioned medium, we optimized the culture conditions of chicken small intestinal organoids by adjusting the proportions of nicotinamide, N-acetylcysteine, LY2157299, CHIR99021, Jagged-1, FGF, and other cytokines to select the medium suitable for the long-term stable growth of the organoids. The optimization results showed that the addition of 1.5 µmol/L CHIR99021 significantly improved the organoid formation efficiency and organoid diameter. When 0.5 µmol/L Jagged-1 was added, a small amount of bud-like tissue appeared in organoids. After the addition of 50 ng/mL FGF-2, the rate of organoid germination was significantly increased. The 1.5 µmol/L CHIR99021, 0.5 µmol/L Jagged-1, and 50 ng/mL FGF-2 added in the medium can cooperate with each other to improve the formation and speed up the proliferation and differentiation of organoids, while improving the stemness maintenance of cells. The morphology, cell types, and culture characteristics of chicken small intestinal organoids were studied by HE staining, transmission electron microscopy, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), indirect immunofluorescence, and immunohistochemistry. The results showed that the 3D organoids of the chicken small intestine cultured in vitro were morphologically consistent with the chicken intestinal tissue and contained differentiated epithelial cells. In summary, we successfully established an in vitro culture system for chicken small intestinal organoids, providing a new method for the subsequent research on chicken intestinal physiology, pathology, and host-pathogen interaction mechanism and the development of relevant drugs.
Animals ; Organoids/metabolism* ; Intestine, Small/drug effects* ; Chickens ; Cell Culture Techniques/methods* ; Culture Media ; Chick Embryo ; Tissue Culture Techniques/methods*

Objective:To investigate the efficacy of intramedullary plus extramedullary fixation in the treatment of fractures of distal radial diametaphyseal transition zone in children.Methods:The data were retrospectively analyzed of the 49 children who had been admitted to Pediatric Orthopedic Hospital, Honghui Hospital Affiliated to Xi'an Jiaotong University from July 2018 to April 2020 for fractures of distal radial diametaphyseal transition zone. There were 30 males and 19 females; 21 left sides, 27 right sides, and one case of bilateral sides. In the operation, an elastic intramedullary nail or Kirschner wire was used for intramedullary fixation while another Kirschner wire was used to fix the cortex at the distal and proximal ends of the fracture. The ranges of wrist motion and Disabilities of the Arm, Shoulder and Hand (DASH) scores at 1 and 9 months after operation were recorded and compared; the incidence of postoperative complications was also recorded.Results:The operation time for the 49 children averaged 45.0 min (from 39 to 51 min). The patients were followed up for 6 to 36 months (mean, 18.6 months). The fracture union time averaged 8.6 weeks (from 6.8 to 10.4 weeks). Needle tract infection developed in one case but the wound was healed after removal of the K-wire after callus formation and oral use of antibiotics for 3 days. Another case reported skin irritation the symptoms of which disappeared after the child reduced activities. The ranges of pronation, supination, flexion and extension of the wrist and DASH score were 47.9°±2.5°, 45.5°±3.0°, 51.2°±1.6°, 53.4°±1.7° and (36.7±4.5) points at one month after operation while they were 85.6°±3.1°, 87.6°±2.1°, 88.8°±2.0°, 88.0°±1.2° and (23.2±8.6) points at 9 months after operation. There were statistically significant differences in the above indexes between one and 9 months after operation ( P<0.05). Conclusion:In the treatment of fractures of distal radial diametaphyseal transition zone in children, intramedullary plus extramedullary fixation is simple in surgical techniques, easily repeatable, slightly invasive, and reliable in fixation.

Objective:To explore the clinical characteristics and treatment of a head-neck separation type of Monteggia equivalent fractures in children.Methods:From March 2016 to February 2019, 12 children sought medical attention at Pediatric Orthopedic Hospital, Honghui Hospital Affiliated to Xi'an Jiaotong University for a head-neck separation type of Monteggia equivalent fractures. They were 8 boys and 4 girls, aged from 3 to 14 years (average, 8.3 years). All cases were treated with closed reduction, deformity correction and plaster fixation at emergency department after X-ray examination. In line with the treatment principles for Monteggia fractures, after the ulnar length was first restored and stabilized, a proper fixation method was chosen according to the location and type of the ulnar fracture, followed by treatment of the radial neck fracture. The fracture union and complications were evaluated according to the X-ray films after operation, and the therapeutic efficacy was evaluated according to the Mayo elbow performance score (MEPS) at the final follow-up.Results:The head-neck separation type of Monteggia equivalent fractures in children was characterized by a fracture of ulnar diaphysis or metaphysis and a fracture of the radial neck with complete separation of the head and neck, a longitudinal axis of the radius off the capitellum center at the distal fracture end but normal proximal humeroradial relationship. The fractures were classified into 2 types depending on the angulation direction of the ulnar fracture and the direction of distal displacement of the radial neck fracture: 7 cases belonged to the extension-valgus type and 5 cases to the flexion-varus type. The 12 patients were followed up for 8 to 38 months (average, 16.0 months). Of the ulnar fractures, one was treated with closed reduction and Kirschner wire fixation, 4 with elastic intramedullary nail fixation, 5 with plate fixation, one untreated, and one with manual reduction only. Of the radial neck fractures, 11 were treated with closed reduction and elastic intramedullary nail fixation, and one with open reduction and K-wires fixation. All fractures got united after 8 to 12 weeks (mean, 9.6 weeks). The time for removal of internal fixation ranged from 12 to 50 weeks (mean, 31.2 weeks). Avascular necrosis occurred in one case and bulk formation of proximal metaphysis in another. By the MEPS at the final follow-up, the therapeutic efficacy was excellent in 10 cases, good in one and fair in one.Conclusions:The head-neck separation type of Monteggia equivalent fractures in children is different from common Monteggia fractures or radial neck fractures, because its clinical manifestations are characterized by a fracture of ulnar diaphysis or metaphysis and a fracture of the radial neck with complete separation of the head and neck, a longitudinal axis of the radius off the capitellum center at the distal fracture end but normal proximal humeroradial relationship. The treatment options for ulnar fractures include closed reduction with Kirschner wire fixation, elastic intramedullary nailing, open reduction and bone plate fixation or no fixation, while radial neck fractures are mostly treated by closed reduction and elastic intramedullary nailing. Early functional exercise can lead to satisfactory clinical outcomes.

Objective:To evaluate the treatment of nonunion of lateral humeral condyle complicated with cubitus valgus with primary fixation in situ and secondary supracondylar varus osteotomy.Methods:A retrospective analysis was made of the 8 children who had been treated for nonunion of lateral humeral condyle complicated with cubitus valgus at Department of Pediatric Orthopedics, Honghui Hospital from January 2016 to March 2018. They were 5 boys and 3 girls with 5 left and 3 right sides involved. Their age at injury ranged from 6 to 14 years (average, 10 years) and the duration from injury to operation from 2 to 6 years (average, 4 years). At the primary stage, the fragments were fixated in situ with compressive cannulated screws after cleaning the nonunion ends, followed by iliac autograft. At the secondary stage, the humeral supracondylar varus osteotomy was performed after the nonunion was healed and the elbow range of motion recovered. The therapeutic effects were assessed by comparing the elbow range of motion, carrying angle and Mayo elbow performance score (MEPS) between preoperation and the final follow-up.Results:All the patients were followed up for an average of 44.5 months (range, from 27 to 64 months). The average healing time for obsolete nonunion of lateral humeral condyle was 81.3 days (range, from 55 to 120 days) after the primary operation and that for supracondylar varus osteotomy 51.1 days (range, from 45 to 60 days) after the secondary operation. The elbow range of motion was 129.0°±4.6° before operation and 138.0°±5.4° at the final follow-up, showing a significant difference ( P<0.001). The average carrying angle at the healthy side in 8 children was 5.4° (range, from 3° to 8°). The carrying angle at the affected side was 31.9°±4.7° (range, from 25° to 42°) before operation and 4.0°±2.2°(range, from 1° to 8°) at the final follow-up, showing a significant difference ( P<0.05). Their preoperative MEPS was 57.5 ± 6.5 (4 good cases and 4 poor ones) but 95.9±3.4 (6 excellent cases and 2 good ones) at the final follow-up, showing a significant difference ( P<0.05). Conclusions:Treatment of nonunion of lateral humeral condyle complicated with cubitus valgus can be effectively carried out by cleaning fibrous tissue in the nonunion gap, iliac autograft and fragments fixation in situ with compressive cannulated screws at the primary stage and supracondylar varus osteotomy at the secondary stage. Intraoperative preservation of the blood supply to the nonunited fragments is the key to successful management.