[Analysis of clinical effect of arthroscopic release at different time in treating knee adhesion after arthroscopic surgery].

Objective: To explore the efficacy of arthroscopic release in treating postoperative knee adhesion and investigate the influence of release timing on the treatment outcomes. Methods: A total of 50 patients who accepted arthroscopic release in Peking University Third Hospital from February 2017 to December 2021 were included in the retrospective cohort. The study cohort comprised 28 men and 22 women, with a mean age of (30.8±11.9) years. All the primary surgeries were manipulated under arthroscopes. A comparison was made between pre-and postoperative range of motion (ROM), visual analog scale (VAS), International Knee Documentation Committee (IKDC) scores, and Tegner activity scale scores for the patients. According to the interval between the appearance of adhesion and arthroscopic release, the patients were divided into four groups:<3 months group (n=12), 3-6 months group (n=16),>6-12 months group (n=14), and>12 months group (n=8). Inter-group comparisons on postoperative ROM, IKDC scores, and Tegner activity scale scores and improvement values of each outcome were conducted. Results: All the patients were followed up for (36.4±19.7) months. Patients gained significant improvement in flexion, extension, IKDC scores, and Tegner scores (125.0°±20.0° vs 75.7°±27.5°, 2.3°±4.8° vs 7.4°±7.3°, 69.8±17.7 vs 51.4±12.8, 4.1±2.1 vs 2.2±1.1) (all P<0.05), while the VAS scores did not show significant improvement. There were no significant differences among different groups in postoperative extension, IKDC scores or Tegner scores, nor in their improvements. However, patients in the ≤6 months group could gain better postoperative flexion and improvement in flexion than those in the >6 months group (129.9°±20.0° vs 118.8°±17.4°, 58.6°±32.8° vs 37.3°±23.1°) (P<0.05). Conclusions: Arthroscopic release presents a great effect in treating knee adhesion after arthroscopic operation. Once the symptoms of adhesion appear and physical rehabilitation fails to improve the ROM, one should accept early surgical intervention (less than 6 months) for a better outcome.

[Discussion on diagnosis and treatment of hepatobiliary malignancies during the outbreak of COVID-19].

Objective: From December 2019, the new coronavirus pneumonia (COVID-19) broke out in Wuhan, Hubei, and spread rapidly to the nationwide. On January 20, 2020, the National Health Committee classified COVID-19 pneumonia as one of B class infectious diseases and treated it as class A infectious disease. During the epidemic period, the routine diagnosis and treatment of tumor patients was affected with varying degrees. In this special period, we performed the superiority of the multi-disciplinary team of diagnosis and treatment, achieved accurate diagnosis and treatment of patients with hepatobiliary malignant tumors, provided support for these patients with limited medical resources, and helped them to survive during the epidemic period.On the basis of fully understanding the new coronavirus pneumonia, the treatment strategy should be changed timely during the epidemic, and more appropriate treatment methods should be adopted to minimize the adverse effect of the epidemic on tumor treatment.

[Desmoplastic fibroblastoma: a clinicopathologic analysis of 7 cases].

Objective: To investigate the clinical features, immunohistochemical and differential diagnosis of desmoplastic fibroblastoma. Methods: The clinical data and pathology features of 7 cases of desmoplastic fibroblastoma were collected and immunohistochemical study were carried out in all cases with a review of the literatures. Results: There were 2 males and 5 females, with age ranging from 31 to 71 years (average and mean age were 59 and 61 years, respectively). The tumors were located in extremities and abdomen (left toe and right toe, right foot back, left leg and right thigh, right forearm and left hepatic lobe). Clinically, the tumors presented as slow growing painless masses of long standing duration. Grossly, the tumors were well-circumscribed with firm, white to gray cut-off surface. Tumor size ranged from 1.2 to 4.0 cm in maximum diameter (average 3.0 cm). Microscopically, 2 cases were located in dermis, 4 cases were located in subcutaneous and 1 case was located in liver parenchyma. It was composed of spindle-shaped or stellate cells with a fibroblastic or myofibroblastic appearance, and sparsely scattered in densely fibrous or fibromyxoid background. There was small vascular component in tumor background. At high magnification, the tumor cells were medium size with abundant cytoplasm, and the nucleus were small and always with small nucleoli. In some cases, the tumor cells were slightly larger with enlarged nuclei, but without cellular atypical and mitosis. Immunohistochemical study showed that the tumor cells were strongly positive for vimentin, desmin, S-100 protein and CD34, but CKpan was negative. α-SMA showed focal positive in one case. Ki-67 index ranged from 1% to 2%. Four cases were followed-up (ranged from 11 to 21 months, average 16.5 months) and the patients had no recurrence after surgery. Conclusions: Desmoplastic firoblastoma is a rare soft benign tumor. The differential diagnosis includes other benign or low-grade fibroblastic/myofibroblastic lesions.

The effects of sensitization and hypersensitivity reaction on transepithelial antigen transport of rat nasal mucosa.

METHODS: The prevalence of airway allergy is very high. The ways that antigen passes across the airway tract epithelial barrier are not well understood. This study uses a model antigen, horseradish peroxidase (HRP), to sensitize and challenge the respiratory tract in the rat model. RESULTS: The results showed increases in HRP endosomes in nasal epithelial cells 5 minutes after HRP challenge in the sensitized rats compared with controls, which were further increased 30 minutes after HRP challenge, as well as with the paracellular region filled with HRP products. Meanwhile, mast cells were activated as shown by degranulation. Analysis of cell type showed that there were many more HRP endosomes in the nonciliated cells and there were many more nonciliated cells in the nasal mucosa of the sensitized rats. CONCLUSION: The results demonstrate that sensitization promotes airway mucosal epithelial cells' uptake and transport of specific antigen and that mast cells may play certain roles in this process.

Iron, DtxR, and the regulation of diphtheria toxin expression.

In recent years considerable advances have been made in the understanding of the molecular basis of iron-mediated regulation of diphtheria toxin expression. The tox gene has been shown to be regulated by the heavy metal ion-activated regulatory element DtxR. In the presence of divalent heavy metal ions, DtxR becomes activated and binds to a 9 bp interrupted palindromic sequence. The consensus-binding site has been determined by both the sequence analysis of DtxR-responsive operators cloned from genomic libraries of Corynebacterium diphtheriae as well as by in vitro genetic methods using cyclic amplification of selected targets (CASTing). It is now clear that DtxR functions as a global iron-sensitive regulatory element in the control of gene expression in C. diphtheriae. In addition, the metal ion-activation domain of DtxR is being characterized by both mutational analysis and determination of the X-ray structure at 3.0 A resolution.