Objective To study the development of hereditary dystrophic retina of rd mice and photoreceptors apoptosis. Methods Retinal sections of rd mice and their controls at different ages ranging from postnatal days 5 to 40 were examined by morphological(light and electronic microscope), morphometric and TUNEL analysis. Results Compared with age-matched control mice, the retinal dystrophy of rd mice began at postnatal days 10, resulting in rapid loss of photoreceptors and reaching a peak at postnatal days 18. TUNEL postitive nucleus of photoreceptor cells emerged from postnatal days 10 and reached a peak at postnatal days 14 and 16. Ultrastructure of photoreceptor cell layer showed marked nuclear pyknotosis and chromatin margination. Apoptotic bodies of photoreceptor cells were observed.Conclusion Rd mice retina degenerated during the process of maturity. Photoreceptor cell death occurred through apoptosis.

BACKGROUND:Pelvic fractures encompass a range of types,and the utilization of a pelvic reduction frame for restoration often lacks a systematic repositioning method.Instead,it relies on the operator's experience in conjunction with fluoroscopic findings,which can lead to uncertainty and non-reproducibility. OBJECTIVE:To investigate the clinical efficacy of combining computer-simulated repositioning techniques with a pelvic reduction frame for the treatment of anteroposterior compression-III pelvic fractures. METHODS:A retrospective analysis was conducted on 19 patients with anteroposterior compression-III pelvic fractures who underwent preoperative repositioning via computer simulation and intraoperative repositioning with the assistance of a pelvic reduction frame between January 2018 and December 2021.Among them,7 cases were fixed with double plate in anterior ring and 12 cases were fixed with single plate combined with anterior subcutaneous internal fixation(INFIX).All patients received posterior ring fixation with two sacroiliac screws.Operative duration,intraoperative reduction time,the frequency of intraoperative fluoroscopy use,blood loss,and follow-up duration were documented.These data were utilized to monitor fracture healing time and postoperative complications.Fracture reduction quality was evaluated according to the Matta scale,and the Majeed Pelvic Function Score was employed to assess patient function during the final follow-up. RESULTS AND CONCLUSION:(1)Surgery was successfully completed in all 19 patients.The anterior ring was secured with double plates in 7 cases,while a single plate combined with INFIX was utilized in 12 cases.The posterior ring was stabilized with two sacroiliac screws,specifically targeting the S1 and S2 cones.(2)The operation duration ranged from 74 to 147 minutes,with a mean of(101.63±19.55)minutes.Intraoperative repositioning took place over a period of 26 to 41 minutes,with a mean of(38.11±3.31)minutes.The number of intraoperative fluoroscopies conducted ranged from 35 to 81,with a mean of(62.68±13.11)times.Intraoperative bleeding volumes varied from 60 to 130 mL,with a mean of(85.37±20.57)mL.(3)All the patients were diligently monitored for a duration of 12 to 26 months.Fracture healing was observed within a time frame of 12 to 20 weeks,with a mean of(16.37±2.50)weeks.(4)The evaluation according to Matta's criteria one day post-surgery revealed excellent outcomes in 14 cases and good outcomes in 5 cases.At the final follow-up,the Majeed function score indicated excellent results in 16 cases and good results in 3 cases.(5)Two patients experienced localized fat liquefaction phenomena,characterized by redness,swelling,and oozing at the incision site,which gradually resolved with proactive dressing changes.None of the patients encountered complications such as internal fixation loosening,loss of fracture reduction,or nerve injuries post-surgery.It is concluded that the combined approach of using computer-simulated repositioning techniques in conjunction with pelvic reduction frames for the treatment of anteroposterior compression-III pelvic fractures has advantages in enhancing repositioning efficiency and improving pelvic function.

OBJECTIVE: To evaluate the effectiveness of limited internal fixation combined with a hinged external fixator in the treatment of peri-elbow bone infection. METHODS: The clinical data of 19 patients with peri-elbow bone infection treated with limited internal fixation combined with a hinged external fixator between May 2018 and May 2021 were retrospectively analyzed. There were 15 males and 4 females with an average age of 44.6 years (range, 28-61 years). There were 13 cases of distal humerus fractures and 6 cases of proximal ulna fractures. All the 19 cases were infected after internal fixation of fracture, and 2 cases were complicated with radial nerve injury. According to Cierny-Mader anatomical classification, 11 cases were type Ⅱ, 6 cases were type Ⅲ, and 2 cases were type Ⅳ. The duration of bone infection was 1-3 years. After primary debridement, the bone defect was (3.04±0.28) cm, and the antibiotic bone cement was implanted into the defect area, and the external fixator was installed; 3 cases were repaired with latissimus dorsi myocutaneous flap, and 2 cases were repaired with lateral brachial fascial flap. Bone defects repair and reconstruction were performed after 6-8 weeks of infection control. The wound healing was observed, and white blood cell (WBC), erythrocyte sedimentation rate (ESR), and C-reaction protein (CRP) were reexamined regularly after operation to evaluate the infection control. X-ray films of the affected limb were taken regularly after operation to observe the bone healing in the defect area. At last follow-up, the flexion and extension range of motion and the total range of motion of the elbow joint were observed and recorded, and compared with those before operation, and the function of the elbow joint was evaluated by Mayo score. RESULTS: All patients were followed up 12-34 months (mean, 26.2 months). The wounds healed in 5 cases after skin flap repair. Two cases of recurrent infection were effectively controlled by debridement again and replacement of antibiotic bone cement. The infection control rate was 89.47% (17/19) in the first stage. Two patients with radial nerve injury had poor muscle strength of the affected limb, and the muscle strength of the affected limb recovered from grade Ⅲ to about grade Ⅳ after rehabilitation exercise. During the follow-up period, there was no complication such as incision ulceration, exudation, bone nonunion, infection recurrence, or infection in the bone harvesting area. Bone healing time ranged from 16 to 37 weeks, with an average of 24.2 weeks. WBC, ESR, CRP, PCT, and elbow flexion, extension, and total range of motions significantly improved at last follow-up ( P<0.05). According to Mayo elbow scoring system, the results were excellent in 14 cases, good in 3 cases, and fair in 2 cases, and the excellent and good rate was 89.47%. CONCLUSION Limited internal fixation combined with a hinged external fixator in the treatment of the peri-elbow bone infection can effectively control infection and restore the function of the elbow joint.
Male ; Female ; Humans ; Adult ; Elbow ; Elbow Joint/surgery* ; Retrospective Studies ; Bone Cements ; Treatment Outcome ; External Fixators ; Fracture Fixation, Internal/methods* ; Fractures, Bone ; Range of Motion, Articular