BACKGROUND:We have successfully established an animal model of small ear pig in southern Yunnan province with internal tension relieving technique combined with autologous Achilles tendon for anterior cruciate ligament reconstruction,and verified the stability and reliability of the model.However,whether internal tension relieving technique can promote the ligamentalization process of autologous Achilles tendon graft has not been studied. OBJECTIVE:To investigate the differences in the process of ligamentalization between conventional reconstruction and internal reduction reconstruction of the anterior cruciate ligament by gross view,histology and electron microscopy. METHODS:Thirty adult female small ear pigs in southern Yunnan province were selected.Anterior cruciate ligament reconstruction was performed on the left knee joint with the ipsilateral knee Achilles tendon(n=30 in the normal group),and anterior cruciate ligament reconstruction was performed on the right knee joint with the ipsilateral knee Achilles tendon combined with the internal relaxation and enhancement system(n=30 in the relaxation group).The autogenous right forelimb was used as the control group;the anterior cruciate ligament was exposed but not severed or surgically treated.At 12,24,and 48 weeks after surgery,10 animals were sacrificed,respectively.The left and right knee joint specimens were taken for gross morphological observation to evaluate the graft morphology.MAS score was used to evaluate the excellent and good rate of the ligament at each time point.Hematoxylin-eosin staining was used to evaluate the degree of ligament graft vascularization.Collagen fibers and nuclear morphology were observed,and nuclear morphology was scored.Ultrastructural remodeling was evaluated by scanning electron microscopy and transmission electron microscopy. RESULTS AND CONCLUSION:(1)The ligament healing shape of the relaxation group was better at various time points after surgery,and the excellent and good rate of MAS score was higher(P<0.05).Moreover,the relaxation group could obtain higher ligament vascularization score(P<0.05).(2)The arrangement of collagen bundles and fiber bundles in the two groups gradually tended to be orderly,and the transverse fiber connections between collagen gradually increased and thickened,suggesting that the strength and shape degree of the grafts were gradually improved,but the ligament remodeling in the relaxation group was always faster than that in the normal group at various time points after surgery.(3)The diameter,distribution density,and arrangement degree of collagen fibers in the relaxation group were better than those in the normal group at all time points,especially in the comparison of collagen fiber diameter between and within the relaxation group(P<0.05).

BACKGROUND:Internal tension-reduction technique is to reconstruct the anterior cruciate ligament through high-strength suture system combined with tendon.It can effectively reduce graft relaxation and frets by sharing the internal load of the knee joint,and has achieved good biomechanical results and clinical efficacy.However,whether it can reduce cartilage degeneration after anterior cruciate ligament reconstruction through stress sharing reduction has not been studied. OBJECTIVE:To investigate the effect of internal tension-reduction technique on articular cartilage degeneration in southern Yunnan small-ear pigs undergoing anterior cruciate ligament reconstruction. METHODS:Ten adult female Yunnan small-ear pigs were selected,and the ipsilateral knee Achilles tendon was taken from the left knee joint for anterior cruciate ligament reconstruction(normal group,n=10),and the ipsilateral knee Achilles tendon from the right knee joint combined with internal tension-reduction and augmentation system for anterior cruciate ligament reconstruction(tension-reduction group,n=10).One year after surgery,the experimental pigs were sacrificed,and the left and right knee cartilage was taken for hematoxylin-eosin staining,Safranin O-fast green staining,Osteoarthritis Research Society International scoring,and immunohistochemistry staining of type Ⅱ collagen,interleukin-1β,and tumor necrosis factor-alpha in the cartilage. RESULTS AND CONCLUSION:Hematoxylin-eosin staining showed that in the tension-reduction group,there were mild pathologic changes of osteoarthritis,with a low number of empty bone lacunae and no obvious pathological changes such as fibrosis or cell layer breakage;in the normal group,more severe cartilage damage,with an increased number of empty bone lacunae,loss of chondrocytes near the bone and even the formation of fissures.Safranin O-fast green staining indicated that the tension-reduction group had normal cartilage tissue thickness,flat cartilage surface,a neat cell arrangement in a polar pattern,and no swelling or apoptosis,while in the normal group,the thickness of cartilage tissue was obviously thinner,the cell arrangement was disordered with no polarity,the number of cells was reduced,obvious cartilage fractures and cartilage vacuoles formed,and the absence of cells near the central bone was obvious.The Osteoarthritis Research Society International score was significantly lower in the tension-reduction group than in the normal group(P＜0.05).Immunohistochemical findings showed that the protein expression of type Ⅱ collagen in cartilage tissue of the tension-reducing group was higher than that of the normal group(P＜0.05),and the protein expression of interleukin 1β and tumor necrosis factor ɑ in cartilage tissue was lower than that of normal group(P＜0.05).To conclude,internal tension-reduction technique can delay the degeneration of articular cartilage in Yunnan small-eared pigs following anterior cruciate ligament reconstruction.

BACKGROUND:As a dominant breed pig in southwest China,the southern Yunnan small-ear pig has been widely used as an experimental animal in the basic research of other disciplines,but there are still no reports on its application in anterior cruciate ligament reconstruction. OBJECTIVE:To establish a large animal model of the southern Yunnan small-ear pig with anterior cruciate ligament with autologous Achilles tendon was established. METHODS:Twenty adult female Yunnan small-ear pigs were equally randomized into two groups.In the autologous Achilles tendon group,the right knee anterior cruciate ligament was reconstructed with autologous Achilles tendon as a graft,while in the sham-operated group,a similar operation was performed on the right knee without any treatment of the anterior cruciate ligament.General conditions of each pig were observed and recorded before and 12 months after surgery.Ligaments and grafts were taken for gross observation and MAS scoring.Hematoxylin-eosin staining was performed to observe morphological characteristics of ligaments.The staining and arrangement of type I and type Ⅲ collagen were evaluated by immunohistochemistry.Transmission electron microscopy was used to observe the type,size,diameter,ratio,and distribution of collagen fibers in ligaments. RESULTS AND CONCLUSION:All animals had normal diet and activity,good wound healing,no obvious inflammatory reaction,no local purulent infection,and no significant changes in mental and urinary conditions compared with those before surgery.The reconstructed cruciate ligament of the knee was intact,with no stiffness and normal range of motion.Both the anterior drawer and Lachman tests were negative.Gross observation of the graft:12 months after surgery,the grafts was in good position,with good integrity,obvious tension,ligament color close to the original anterior cruciate ligament,and complete surface synovial coverage.Most of the intraarticular ligaments in the autologous Achilles tendon group were defined as MAS I type and a few were defined as MAS Ⅱ type.In the sham-operated group,the intraarticular ligament was defined as MAS I type.Hematoxylin-eosin staining indicated that,12 months after surgery,collagen fibers in the autologous Achilles tendon group began to appear bundled,isotropic,and uniformly arranged,with more obvious isotropic corrugations,and the nuclei were mainly linear or spindle-shaped,which were similar to those in normal anterior cruciate ligament tissue of the sham-operated group.Immunohistochemistry results indicated that,12 months after surgery,there was a higher expression of type I collagen and significantly less expression of type Ⅲ collagen in the reconstructed anterior cruciate ligament in the autologous Achilles tendon group.The degree of type I and type Ⅲ staining was similar in the two groups.Under the transmission electron microscope,the diameter,arrangement and density of collagen fibers in the reconstructed anterior cruciate ligament of the autologous Achilles tendon group were similar to those of the original anterior cruciate ligament at 12 months after surgery,indicating that the ligament remodeling process had been basically completed in the autologous Achilles tendon group at 12 months after surgery.Through a comprehensive evaluation of animal general conditions,ligament general view,MAS score,hematoxylin-eosin staining,immunohistochemistry,and transmission electron microscopy observation,we successfully established a large animal model of anterior cruciate ligament reconstruction using autogenous Achilles tendon in southern Yunnan small-ear pigs,with good morphological,histological and ultrastructural results.

The present case report described a patient with paroxysmal atrial fibrillation who received pulsed-filed ablation guided by intracardiac echocardiography and 3-dimentional mapping system.All four pulmonary veins were isolated in the procedure,good clinical results and acute safety profile were achieved.The present case reveals the safety and feasibility of the technique for the treatment of paroxysmal atrial fibrillation.

Acute respiratory distress syndrome (ARDS) refers to acute diffuse lung injury caused by a variety of intrapulmonary and/or extrapulmonary factors such as infection and trauma. Uncontrolled inflammatory response is the main pathological feature. Different functional states of alveolar macrophages have different effects on inflammatory response. Transcription activating factor 3 (ATF3) is a fast response gene in the early stage of stress. In recent years, it has been found that ATF3 plays an important role in regulating the inflammatory response of ARDS by regulating the function of macrophages. This paper reviews the regulatory effects of ATF3 on alveolar macrophage polarization, autophagy and endoplasmic reticulum stress and its effects on the inflammatory process of ARDS, aiming to provide a new research direction for the prevention and treatment of ARDS.

Objective:To compare the clinical efficacies between arthroscopic anatomic single bundle reconstruction of posterior cruciate ligament (PCL) assisted by internal tension relieving technique combined with rapid rehabilitation and anatomic single bundle reconstruction combined with conventional rehabilitation in the treatment of PCL rupture.Methods:A retrospective cohort study was used to analyze the clinical data of 88 patients with PCL rupture admitted to First Affiliated Hospital of Kunming Medical University from September 2016 to September 2020. The patients included 65 males and 23 females, aged 18-55 years [(39.3±10.8)years]. Forty-four patients underwent arthroscopic anatomic single bundle reconstruction of PCL assisted by internal tension relieving technique combined with rapid rehabilitation therapy (tension-relieving group), and 44 patients underwent arthroscopic routine anatomic single bundle reconstruction of PCL combined with conventional rehabilitation (traditional group). The two groups were compared before and at 3, 12, and 24 months after surgery regarding the following items: International Knee Literature Committee (IKDC) score, Hospital for Special Surgery (HSS) score, Lysholm score, knee motion cycle (maximum stride length, minimum stride length, and stride frequency) and 6 kinematic indicators (angle of forward and back extension, angle of internal and external rotation, angle of internal and external rotation, up and down displacement, internal and external displacement, and forward and back displacement). The Marburger arthroscopy score (MAS) and Professor Ao Yingfang′s improved score by secondary arthroscopy were compared between the two groups at 12 months after surgery. The perioperative complications were observed.Results:All patients were followed for 24-36 months [(25.5±6.3)months]. In tension-relieving group and the traditional group, the values of IKDC score were (71.8±9.8)points and (68.5±6.5)points at 3 months after surgery, (87.6±6.0)points and (87.6±5.5)points at 12 months after surgery, and (95.5±3.1)points and (92.8±11.6)points at 24 months after surgery, respectively. The values were gradually increased, significantly higher than those before surgery [(48.1±16.9)points and (47.1±15.0)points] (all P<0.05). There were no significant differences between the two groups at each time point (all P>0.05). In tension-relieving group and the traditional group, the values of HSS score were (74.2±6.2)points and (68.4±9.5)points at 3 months after surgery, (91.9±5.4)points and (88.4±4.7)points at 12 months after surgery, and (97.1±2.0)points and (96.2±2.8)points at 24 months after surgery, respectively. The values of HSS score gradually increased, significantly higher than those before surgery [(57.5±17.7)points and (56.8±14.3)points] (all P<0.05). At 3 and 12 months after surgery, the values of HSS score in the tension-relieving group were significantly higher than those in the traditional group (all P<0.05), but others were not significantly different between the two groups (all P>0.05). In tension-relieving group and the traditional group, the values of Lysholm score were (74.2±14.9)points and (70.3±7.5)points at 3 months after surgery, (90.9±6.1)points and (88.7±4.7)points at 12 months after surgery, and (96.9±3.0)points and (96.3±2.8)points at 24 months after surgery, respectively. The values of Lysholm score were gradually increased, significantly higher than those before operation [(48.7±20.7)points and (48.2±19.9)points] (all P<0.05). There were no significant differences between the two groups at any time points (all P>0.05). At 3, 12, and 24 months after surgery, the motion cycle (maximum stride length, minimum stride length and stride frequency) and 6 kinematic indicators (angle of forward bending and backward extension, angle of internal and external rotation, angle of internal and external rotation, internal and external displacement, up and down displacement, and forward and backward displacement) of knee joint were significantly improved in both groups compared with those before surgery (all P<0.05). At 3, 12, and 24 months after surgery, the forward and backward displacement in the tension-relieving group was significantly decreased than that in the traditional group (all P<0.05), but others were not significantly different between the two groups (all P>0.05). The MAS was rated as excellent to good in 14 patients and fair to poor in 2, with the excellent and good rate of 87.5% (14/16) in the tension-relieving group, while the score was rated as excellent to good in 11 patients and fair to poor in 3, with the excellent and good rate of 78.6% (11/14) in the traditional group ( P>0.05). The Professor Ao Yingfang′s improved score was (10.6±1.5)points in the tension-relieving group, markedly higher than that in the traditional group [(9.6±2.3)points] ( P<0.05). No perioperative complications were observed. Conclusion:Compared with anatomic single bundle reconstruction combined with conventional rehabilitation, arthroscopic anatomic single bundle reconstruction of PCL assisted by internal tension relieving technique combined with rapid rehabilitation have higher subjective function score, better anteroposteric stability during knee movement, and better results of secondary microscopy.

【Objective】 To explore the diagnosis and treatment of mixed germ cell tumor (MGCT). 【Methods】 Clinical data of 11 confirmed MGCT cases treated in our hospital during Mar.2017 and Aug.2022 were retrospectively analyzed. The clinical characteristics, treatment methods and therapeutic effects were analyzed. The relevant literature and guidelines were discussed. 【Results】 MGCT cases accounted for 18.3% (11/60) of testicular cancer(TC) cases and 21.2% (11/52) of germ cell tumor (GCT) cases treated in our department during the same period. All 11 MGCT cases had unilateral lesions, which were on the left side in 7 cases, and on the right side in 4 cases, with a ratio of left to right side of 1.75∶1. The age of onset ranged from 21 to 52 years, average (29.8±8.7) years. All cases received unilateral radical orchiectomy(RO), 7 received retroperitoneal lymph node dissection(RPLND) (1 robotic RPLND), 6 received postoperative chemotherapy, and 1 received postoperative radiotherapy. During the follow-up of 2 to 66 [average (31.9±20.9)months] , no recurrence or metastasis were observed. 【Conclusion】 MGCT is a relatively rare malignant tumor in clinical practice, with worse prognosis than seminoma germ cell tumor (SGCT). Standardized diagnosis and treatment based on the special characteristics of each pathological type can improve the survival.

OBJECTIVE: To investigate the feasibility of establishing an anterior cruciate ligament (ACL) reconstruction model using hamstring tendon autograft in cynomolgus monkeys. METHODS: Twelve healthy adult male cynomolgus monkeys, weighing 8-13 kg, were randomly divided into two groups ( n=6). In the experimental group, the ACL reconstruction model of the right lower limb was prepared by using a single bundle of hamstring tendon, and the ACL of the right lower limb was only cut off in the control group. The survival of animals in the two groups was observed after operation. Before operation and at 3, 6, and 12 months after operation, the knee range of motion, thigh circumference, and calf circumference of the two groups were measured; the anterior tibial translation D-value (ATTD) was measured by Ligs joint ligament digital body examination instrument under the loads of 13-20 N, respectively. At the same time, the experimental group underwent MRI examination to observe the graft morphology and the signal/ noise quotient (SNQ) was caculated. RESULTS: All animals survived to the end of the experiment. In the experimental group, the knee range of motion, thigh circumference, and calf circumference decreased first and then gradually increased after operation; the above indexes were significantly lower at 3 and 6 months after operation than before operation ( P<0.05), and no significant difference was found between pre-operation and 12 months after operation ( P>0.05). In the control group, there was no significant change in knee range of motion after operation, showing no significant difference between pre- and post-operation ( P>0.05), but the thigh circumference and calf circumference gradually significantly decreased with time ( P<0.05), and the difference was significant when compared with those before operation ( P<0.05). At 6 and 12 months after operation, the thigh circumference and calf circumference were significantly larger in the experimental group than in the control group ( P<0.05). At 3 and 6 months after operation, the knee range of motion was significantly smaller in the experimental group than in the control group ( P<0.05). Under the loading condition of 13-20 N, the ATTD in the experimental group increased first and then decreased after operation; and the ATTD significantly increased at 3, 6 months after operation when compared with the value before operation ( P<0.05). But there was no significant difference between the pre-operation and 12 months after operation ( P>0.05). There was no significant change in ATTD in the control group at 3, 6, and 12 months after operation ( P>0.05), and which were significantly higher than those before operation ( P<0.05). At each time point after operation, the ATTD was significantly smaller in the experimental group than in the control group under the same load ( P<0.05). The MRI examination of the experimental group showed that the ACL boundary gradually became clear after reconstruction and was covered by the synovial membrane. The SNQ at each time point after operation was significantly higher than that before operation, but gradually decreased with time, and the differences between time points were significant ( P<0.05). CONCLUSION The ACL reconstruction model in cynomolgus monkey with autogenous hamstring tendon transplantation was successfully established.
Animals ; Male ; Anterior Cruciate Ligament/surgery* ; Anterior Cruciate Ligament Injuries/surgery* ; Anterior Cruciate Ligament Reconstruction ; Hamstring Tendons/surgery* ; Knee Joint/surgery* ; Macaca fascicularis ; Transplantation, Autologous

Objective:To explore the application method and effect of online teaching of pediatrics in undergraduate clinical medicine.Methods:From March to August, 2020, two classes of pediatrics were selected as research objects: 67 students from Batch 2016 "5+3" clinical medicine class were taught by providing recorded teaching resources and online communication and answering questions (hereinafter referred to as "recorded courses"); 39 students from Batch 2015 "5+3" clinical medicine class were taught by live courses and online communication and answering questions (hereinafter referred to as "live courses"). Through the questionnaire survey on the two groups of students, the effect of the two online teaching methods were compared and the medical students' views and suggestions on them were collected. SPSS 26.0 was used for statistical analysis.Results:Most of the students in the two groups (98.1%) agreed with the effect of the online teaching of pediatrics and thought it could meet their learning needs. There was no significant difference in the online teaching effect between recorded courses group and live courses group ( P > 0.05). However, they had a poor recognition with the implementation of complete online teaching in the future, while they preferred the combination of online teaching with practical exercises in offline hospitals. Conclusion:Online teaching of pediatrics has been recognized by medical students. The two online teaching methods have their own advantages: recorded courses are more planned and the content is more rigorous; live courses are more interactive and flexible. However, considering that medicine is a highly practical subject, it still needs to be supplemented by offline practice while giving full play to the advantages of online teaching.

High mobility group protein B1 (HMGB1), a highly conversed non-histone nucleoproteins with strong pro-inflammatory property, is one of the inflammatory mediator of the acute respiratory distress syndrome (ARDS). Numerous studies have confirmed that HMGB1 regulates ARDS by binding to receptor for advanced glycation end product (RAGE), Toll-like receptor (TLR) and etc. And it can significantly increase the mortality of ARDS. But the mechanism of HMGB1 release is still unclear. This study focuses on the HMGB1 release progress, which connected with Janus kinases/signal transducer and activator of transcription (JAK/STAT), nuclear factor-κB (NF-κB), Notch, inflammasome, tumor necrosis factor (TNF), mitogen-activated protein kinase (MAPK), reactive oxygen species (ROS), peroxisome proliferator-activated receptor (PPAR) and other signaling or dependent pathways in ARDS.