In view of the characteristics of the learning curve for medical students,the ' three phases and seven steps' case-based learning model was designed and implemented by Changzheng Hospital,the Second Military Medical University.This model was carried out in the theoretical study stage,the first round of internship and the second round of internship.Cases of single diseases,multiple diseases involving variant systems and a variety of diseases involving different department were enrolled for analysis and discussion.Implementation of each case study was divided in seven procedures:determining learning objective and choosing typical case,studying case and raising questions,panel discussions and establishment of common problems,looking up for information to answer questions and preparing report slide,large group discussions,summary and evaluation.'Three phases and seven steps' case based learning model ensure the width and depth of basic medical knowledge learned by the students.With the practice of this model,the basic medical knowledge was constructed systemically and comprehensively by medical students.Students' abilities of problem-analyzing and problem-solving as well as clinical research were developed.This model was effective according to our practice and was worth spreading out.

Objective To investigate the changes at the motor end-plate (i. e. neuromuscular junction) following the free neurovascular muscle transfer. Methods Light and electron microscopy were used to study serially during 30 weeks the changes at the neuromuscular junction after free muscle transfer of the gracilis muscle in the adult Wistar rat. Results Under light microscopy, after staining with acetylthocholine the neuromuscular junction showed changes of degeneration with withdrawal of the innervating axon terminal followed by regeneration and reconstitution of the neuromuscular junction. With the electron microscope, mitochondrial sweelling and clumping of the synaptic vesicles were followed by withdrawal of the axon terminal from the muscle membrane on denervation. The infolding of the muscle membrane at the neuromuscular junction became less prominent. With reinnervation the ulatrastructure of the junction was only partially reestablishied with poorly reconstituted primary and secondary folds of the muscle membrane. The newly formed neuromuscular junction still lacked the structural detail seen in the control neuromuscular junction, even after 30 weeks. Conclusion The persistent weakness following free neurovascular muscle transfer may be attributed to the failure of full recovery of the intricate ultrastructure of the neuromuscular junction.

The students are consciously taught how to think the surgery and how to analyze and solve problems in the animal surgery curriculum.

Objective To study the response of NG2 positive and other glial cells in the facial nucleus after facial nerve axotomy,and explore the changes of the microenvironment in the facial nucleus.Methods Rat facial nerve axotomy models were established.Immunofluorescence double staining,and immunohistochemical staining combined with cresyl violet staining were used to observe the response of NG2 cells and other glial cells,and Western blotting was performed to test NG2 protein expression in facial nucleus at postoperative 1,2,7,14,and 28 days.Results Microglia formed dense circles closely around the injured neurons.Astrocytes formed wreath-like structure near the injured neurons.NG2 protein in the injured nucleus has a regular timephase change and NG2 positive cells showed an extensive detachment of synaptic terminals on the damaged neurons after facial nerve axotomy.NG2 cell response was almost the same as microglia.Conclusions All kinds of glial cells may be involved in the formation of glial scar.NG2 positive cells could insulate the damaged neurons against the potential damage from the excitatory input.

Objective To investigate the feasibility of urethral prefabrication with vaginal mucosa in female-to-male transsexuals and to compare the urologic complications after penile reconstruction in female-to-male transsexuals between prefabrication group and forearm group.Methods Prefabrication of the neourethra with tubed vaginal mucosal graft was performed for 22 female-to-male transsexual patients from 2007 to 2016,while radial forearm flap,known as the traditional tube-within-tube method,was used to construct the neourethra for other 31 cases.Results All of the reconstructed penises survived completely and allowed the patients to urinate while standing in the prefabrication group.Phalloplasty by using the vaginal mucosal graft for urethroplasty significantly decreased the donor scar,the duration of the second operation and the incidence rates of urologic strictures,comparing with the forearm group (P＜0.05).Conclusions It is reliable to use the prefabrication of the neourethra with tubed vaginal mucosal graft in phalloplasty female-to-male transsexual patients.

Objective To present our experience and techniques with the use of autologous costal cartilage grafts in Asian rhinoplasty,and to report the surgical results and complications in 86 consecutive rhinoplasty cases.Methods All operations were performed by the first author (Liu AT) with open approach,costal cartilages and perichondrium were used to reconstruct the nasal tip projection according to the tripod theory in rhinoplasty,after removing the previous injection material,L-shaped implant or hypertrophic scar tissue in the tip.Medical charts and operative records were reviewed retrospectively to summary the complications.Nasal dorsum augmentation was done by costal cartilage or I-shaped allograft,sometimes with anterior sheath of rectus abdominis.Patients' subjective satisfaction of the postoperative nasal appearance was self-evaluated with grading (1 worse,2 no change,3 improved,and 4 much improved).Results From September 2015 to March 2017,86 patients underwent rhinoplasty at our hospital.The postoperative follow-up duration was 6 to 20 months.Overall,functional and aesthetic outcome was satisfactory in most patients,and the mean score by the patients' self-evaluation was 3.3 ± 0.6.Graft exposure,mobility,or significant resorption,pneumothorax or significant donor-site pain were not observed.Conclusions Even with minimal complications and morbidities,autologous costal cartilage grafts in Asian rhinoplasty is a versatile and reliable graft material for nasal tip surgery in severe short or saddle nose,contracted nose due to previous L-shaped augmentation and revision rhinoplasty in which the septal cartilage has already been harvested.

Objective To clarify the applied anatomy of Chinese female breasts,to improve the breast reduction mammoplasty,and to compare the quality of life in women with symptomatic macromastia before and after reduction mammoplasty with the modified round block technique.Methods The blood supply and innervation of the nipple-areolar complex were dissected in 6 Chinese adult females (12 breast specimens).Special attention was paid to the Würinger horizontal septum and the medial and lateral ligaments.The specific beneficial effects of reduction mammoplasty were evaluated with the modified round block technique,and a general questionnaire the Short Form-36 Health Survey Questionnaire (SF-36) was used in this study,which has good reliability and validity.The scores of the patients before and after the surgery were collected respectively.Results In 12 breast specimens,there existed Würinger horizontal septum and the medial and lateral ligaments.The blood supply and nerve innervation of nipple-areolar complex went along Würinger horizontal septum.In all the patients enrolled,SF-36 showed significant higher quality of life after the operation with regard to 7 of 8 investigated domains.Role of emotion increased most significantly.Increased self-esteem and increased personal and public self-consciousness after surgery were observed.Conclusions The incidence of postoperative complications is reduced after using the modified round block technique.Patients have a higher degree of satisfaction overall.These data are further evidence that breast hypertrophy is not solely an esthetic problem.The reduction mammoplasty with the modified round block technique is an ideal technique.

Objective:To explore the effect of two different treatment methods of dorsum implants using autologous costal cartilage, accordion technique (AT) and multilayer oppositional suture technique (MOST), in preventing complications such as distortion and warping of the grafts.Methods:From January 2016 to December 2019, 119 patients underwent rhinoplasty with autologous costal cartilage as the dorsum implant. The dorsum implants were processed by two different techniuqes. Medical charts and operative records were reviewed to summary the complications, especially warping. Patients′ subjective satisfaction and doctors′ objective measurement of the postoperative nasal appearance were evaluated with a grading system.Results:The postoperative follow-up duration was 6 to 28 months. Graft exposure, mobility, or significant resorption, pneumothorax or significant donor-site pain were not observed. The warping rate was higher in the AT (7.8%, 6/77) than in the MOST (2.4%, 1/42) group, although not significantly. Overall, there were no differences in overall patient functional and aesthetic satisfaction between the two groups.Conclusions:Multilayered oppositional suture technique for the autologous costal cartilage grafting may minimize the complication of graft warping and might be an effective alternative for nasal dorsal augmentation, particularly in Asian patients.

Objective:To investigate the postoperative effect of paranasal concavity augment by block united with diced autologous costal cartilage.Methods:The data of 76 patients who were underwent costal cartilage rhinoplasty together with paranasal augmentation from January 2016 to December 2019 were analyzed retrospectively. The surgical technique was described in detail. Medical charts and operative records were reviewed to summary the complications. Patients′subjective satisfaction of the postoperative nasal appearance was self-evaluated with grading (1 worse, 2 no change, 3 improved, and 4 much improved). Cosmetic effects were evaluated by the measurements of the nasolabial angle and the distance between ACJ and intertragic notch preoperatively and postoperatively.Results:The postoperative follow-up duration was 6 to 34 months. Overall, functional and aesthetic outcome was satisfactory in most patients, and the mean score by the patients′self-evaluation was 3.4±0.5. Graft exposure, mobility, or significant resorption, pneumothorax or significant donor-site pain were not observed. The average nasolabial angle was changed from (78.2±13.2)° preoperatively to (89.8±10.2)° 6 months postoperative at the last follow-up ( t=152.00, P<0.01). And the distance from the alar-cheek junction to the left tragus was increased by 3.8±2.1 (2.2-6.1) mm. Conclusions:Costal cartilage rhinoplasty combined with augmentation of parasal area can improve parasal depression, with stable postoperative effect and fewer postoperative complications, and has a good effect for patients with normal occlusal relationship or mild abnormality.