Objective To analyze the clinical and therapeutic characteristics of Epstein-Barr virus (EBV)-negative posttransplant lymphoproliferative disease (PTLD) with diffuse large B-cell lymphoma (DLBCL) in the context of specific cases and literature. Methods A case of EBV-negative DLBCL (GCB type) after kidney transplantation is reported. The patient was a 45-year-old male who underwent living-related kidney transplantation in 2016 and has been receiving triple immunosuppressive therapy with tacrolimus, mycophenolate mofetil and methylprednisolone since then. In 2024, the patient presented with intermittent fever, night sweats and gastrointestinal symptoms. The diagnosis was confirmed by endoscopic pathology, immunohistochemical staining and positron emission tomography/computed tomography. The R-CDOP regimen (rituximab + cyclophosphamide + liposomal doxorubicin + vincristine + dexamethasone) was used for treatment. Results The patient was diagnosed with EBV-negative DLBCL (GCB type, Ann Arbor stage Ⅳ B). After 4 cycles of R-CDOP chemotherapy, the efficacy assessment was partial remission, and the transplant kidney function remained stable. Conclusions For EBV-negative PTLD after kidney transplantation, it is necessary to break through the "virus-dependent" diagnostic thinking. In clinical practice, the focus should be on protecting the transplant kidney, and individualized treatment plans should be developed for patients.

Objective To analyze the expression levels of a-smooth muscle actin (α-SMA) and Vimentin in spindle cells and their relationship with the prognosis of patients with myxofibrosarcoma (MFS). Methods The imaging, clinical, and pathological data of 61 patients with MFS were collected. All patients were confirmed by surgical and postoperative pathological examination. Immunohistochemical methods were used to determine the positive proportion of α-SMA and Vimentin. The correlation between the expression levels of α-SMA and Vimentin in spindle cells and prognosis was analyzed. Results The positive rates of α-SMA and Vimentin expression in MFS tissues were 68.85% and 60.66%, respectively. The expression of Vimentin was not significantly correlated with 3-year OS and DFS (P=0.351, P=0.284). The expression of α-SMA was significantly correlated with OS and DFS (P=0.030, P=0.017), and patients with high expression of α-SMA have shorter OS and DFS. Conclusion Determining α-SMA level can help evaluate the prognosis of patients with MFS and guide clinical treatment.

3D printing technology plays a vital role in orthopedic teaching. This review summarizes the current applications of 3D printing technology in this field. By generating highly realistic personalized anatomical models, 3D printing overcomes the limitations associated with traditional teaching such as resource scarcity and ethical concerns, and offers a more authentic and detailed anatomical learning experience. It not only enables students to repeatedly practice in surgical simulations, thus enhancing their practical skills and confidence, but also promotes personalized teaching tailored to the diverse learning needs of students. This article reviews future development directions, aiming to provide a reference for the reform of orthopedic teaching.

Objective To investigate the impact of the dominant deafness point mutation p.D179N on the oli-gomeric equilibrium state of Connexin 26(Cx26).Methods The wild-type Cx26 fusion protein(Cx26-WT-GFP)and mutant fusion proteins(Cx26-D179N-GFP,Cx26-D179C-GFP)were expressed in HEK293F cells.By using Fluorescence-detection size-exclusion chromatography(FSEC)and size-exclusion chromatography(SEC)to analysis the oligomeric state of the target protein based on malecular weight under the condition of solubilization and purifica-tion respectively.Cryo-electron microscopy(Cryo-EM)single particle analysis(SPA)was conducted to analysis the target protein's oligomeric states based on the 2D classification morphology of the protein particles.Results In vitro,the wild-type Cx26 protein(Cx26-WT)is almost exclusively dodecameric.The deafness mutation p.D179N protein(Cx26-D179N)exists as both dodecamers and hexamers,whereas the artificial mutation p.D179C protein(Cx26-D179C)does not form dodecamers.Conclusion The dominant deafness mutation GJB2 p.D179N could weaken the ability of docking between hexameric proteins,which could affect the balance between hexamers and do-decamers.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Objective:To compare the efficacy of biplanar fixation combined with bone grafting and proximal femoral nail anti-rotation (PFNA) in the treatment of critically complicated osteoporotic intertrochanteric femoral fracture .Methods:A retrospective cohort study was conducted to analyze the clinical data of 28 patients with critically complicated osteoporotic intertrochanteric femoral fracture, admitted to Union Hospital, Tongji Medical College of Huazhong University of Science and Technology from January 2020 and December 2022, including 3 males and 25 females, aged 70-91 years [(79.4±6.3)years]. T score for bone mineral density was -2.5~-4.1 SD［（-3.3±0.6）SD］. All the patients were found with type A2.2-A3.3 fracture based on AO classification, and were complicated with trochanteric lateral wall fracture. Among them, 16 patients underwent biplanar fixation combined with bone grafting (biplanar fixation group), while 12 underwent PFNA internal fixation (PFNA group). All the patients received anti-osteoporosis therapy after surgery. The two groups were compared in terms of the operative time, intraoperative blood loss, hemoglobin levels at 3 days postoperatively, and time to weight-bearing. The visual analogue scale (VAS) scores and Harris hip scores at 1, 3, 6 months postoperatively, and at the last follow-up and the incidence of complications were also detected in the two groups.Results:All the patients were followed up for 12-16 months [(14.1±1.4)months]. In the biplanar fixation group, the operative time was (75.1±15.3)minutes, significantly longer than (45.6±14.2)minutes in the PFNA group ( P<0.01); the intraoperative blood loss was (234.1±11.8)ml, significantly more than (170.0±13.4)ml in the PFNA group ( P<0.01); the hemoglobin level at 3 days postoperatively was (82.6±9.3)g/L in the biplanar fixation group, higher than (64.8±6.8)g/L in the PFNA group ( P<0.01). The time to weight-bearing was (1.1±0.7)weeks in the biplanar fixation group, significantly shorter than (3.2±1.2)weeks in the PFNA group ( P<0.01). There were no statistically significant differences between the two groups in VAS scores and Harris hip scores at 1, 3, 6 months postoperatively, and at the last follow-up ( P>0.05). The VAS scores and Harris hip scores in the two groups were gradually improved with the prolongation of postoperative time ( P<0.05 or 0.01). No complications such as neurovascular injuries were observed in either group. One patient in the biplanar fixation group developed lower extremity deep vein thrombosis (DVT), with a complication rate of 6.3%, while 2 patients in the PFNA group developed lower extremity DVT and 4 hypostatic pneumonia, with a complication rate of 50.0% ( P<0.05). Conclusion:Compared with PFNA internal fixation, biplanar fixation with bone grafting has the advantages of less postoperative blood loss, earlier weight-bearing exercises and lower incidence of complications in the treatment of critically complicated osteoporotic intertrochanteric femoral fracture, despite longer operative time and more intraoperative blood loss.

Objective To analyze the characteristics of HIV-1 pretreatment drug resistance(PDR)and molecular transmission networks in Yubei District,Chongqing,providing evidence for targeted interventions.Methods Using a cross-sectional design,plasma samples were collected from HIV/AIDS patients receiving antiretroviral therapy(ART)in Yubei District from January 2022 to December 2023.Pol gene fragments were extracted and amplified for HIV-1 genotyping and drug resistance analysis.Molecular transmission networks were constructed based on genetic distance calculations.Results Among 478 HIV-1 pol sequences,eight geno-types were identified:with CRF07_BC(60.4%,289/478),CRF08_BC(15.5%,74/478),CRF01_AE(11.7%,56/478),and CRF85_BC(5.9%,28/478).The overall PDR rate was 6.3%(30/478),with resistance to nucleoside reverse transcriptase inhibitors(NRTIs)and non-nucleoside reverse transcriptase inhibitors(NNRTIs)at 1.7%(8/478)and 5.2%(25/478),respectively.No protease inhibitor(PI)resistance was de-tected.The molecular network included 177 cases(37.0%network entry rate),forming 53 clusters with 198 connections.Cluster sizes ranged from 2 to 17 nodes,and 75.3%(149/198)of connections were associated with five subdistricts/towns:Shuanglonghu Street,Huixing Street,Luoqi Town,Gulu Town,and Baoshenghu Street.Conclusion HIV-1 genotypes in Yubei District exhibit diversity and complexity,with moderate PDR prevalence.Regional clustering of transmission networks suggests the need for enhanced molecular surveil-lance and targeted interventions based on analytical findings.

3D printing technology plays a vital role in orthopedic teaching. This review summarizes the current applications of 3D printing technology in this field. By generating highly realistic personalized anatomical models, 3D printing overcomes the limitations associated with traditional teaching such as resource scarcity and ethical concerns, and offers a more authentic and detailed anatomical learning experience. It not only enables students to repeatedly practice in surgical simulations, thus enhancing their practical skills and confidence, but also promotes personalized teaching tailored to the diverse learning needs of students. This article reviews future development directions, aiming to provide a reference for the reform of orthopedic teaching.

Objective:To analyze the incidence and impact on the auditory prognosis of vertigo/dizziness in sudden sensorineural hearing loss patients with moderately severe hearing loss and above. Methods:Clinical data of patients with unilateral sudden sensorineural hearing loss hospitalized from January 2008 to December 2022, aged 18-60 years, PTA≥50 dB HL, and within 14 days of onset were selected. Based on the clinical records of sudden sensorineural hearing loss patients, we determined whether they were accompanied by vertigo/dizziness. The degree of hearing loss is referenced to the 2021 WHO grading criteria and divided into the moderately severe, severe, profound, and total deafness groups. The SPSS 22.0 software was applied to analyze the difference in the auditory prognosis between sudden sensorineural hearing loss patients with moderately severe hearing loss and above who have dizziness/vertigo and those who do not. Results:A total of 697 patients with moderately severe hearing loss and above were collected, including 382 males and 315 females, with an average age of（40.8±11.0） years. The proportions of sudden sensorineural hearing loss patients with dizziness/vertigo among those with moderately severe to total deafness hearing loss were 18.4%, 35.7%, 47.9%, and 76.4% respectively. Compared to the moderately severe, severe, profound, and total deafness groups, the difference was statistically significant（P<0.001）. The complete recovery rates of sudden sensorineural hearing loss patients with moderately severe to total deafness hearing loss were 28.2%, 25.2%, 18.2%, and 1.9% respectively, and the total effective rates were 72.8%, 83.5%, 86.7%, and 78.0% respectively. There were statistically significant differences in complete recovery rate（P<0.001）, significant efficiency rate（P<0.001）, effective rate（P=0.026）, and no recovery rate（P=0.022） among the moderately severe, severe, profound, and total deafness groups. The differences in complete recovery between sudden sensorineural hearing loss patients with and without vertigo/dizziness were statistically significant in the moderately severe, severe, profound, and total deafness groups（P<0.05）, while the total effective rates were only statistically significant in the profound group compared to those without vertigo/dizziness（P<0.05）. After inpatient treatment, sudden sensorineural hearing loss patients with dizziness/vertigo had statistically significant final hearing thresholds at 4 000 and 8 000 Hz for moderately severe hearing loss patients, 2 000-8 000 Hz for severe hearing loss patients, 500-8 000 Hz for profound hearing loss patients, and 2 000-8 000 Hz for total deafness patients compared to those without dizziness/vertigo（P<0.05）. Conclusion:The higher the degree of hearing loss in patients with moderately severe hearing loss and above, the higher the proportion of accompanied vertigo/dizziness. Patients with vertigo/dizziness have poorer recovery of high-frequency hearing, and the complete recovery rate is significantly lower than the patients without vertigo/dizziness.
Humans ; Male ; Female ; Hearing Loss, Sudden/complications* ; Adult ; Dizziness/complications* ; Prognosis ; Middle Aged ; Hearing Loss, Sensorineural/complications* ; Vertigo/complications* ; Young Adult ; Adolescent

Objective To investigate the impact of the dominant deafness point mutation p.D179N on the oli-gomeric equilibrium state of Connexin 26(Cx26).Methods The wild-type Cx26 fusion protein(Cx26-WT-GFP)and mutant fusion proteins(Cx26-D179N-GFP,Cx26-D179C-GFP)were expressed in HEK293F cells.By using Fluorescence-detection size-exclusion chromatography(FSEC)and size-exclusion chromatography(SEC)to analysis the oligomeric state of the target protein based on malecular weight under the condition of solubilization and purifica-tion respectively.Cryo-electron microscopy(Cryo-EM)single particle analysis(SPA)was conducted to analysis the target protein's oligomeric states based on the 2D classification morphology of the protein particles.Results In vitro,the wild-type Cx26 protein(Cx26-WT)is almost exclusively dodecameric.The deafness mutation p.D179N protein(Cx26-D179N)exists as both dodecamers and hexamers,whereas the artificial mutation p.D179C protein(Cx26-D179C)does not form dodecamers.Conclusion The dominant deafness mutation GJB2 p.D179N could weaken the ability of docking between hexameric proteins,which could affect the balance between hexamers and do-decamers.