This paper systematically elaborates on the key points of diagnosis and differential diagnosis of salivary gland tumors characterized by a substantial amount of extracellular mucus as a main or prominent feature, and clarifies the core differential features. The term "mucus-rich" specifically denotes that mucus is a major component of the tumor, rather than a focal or minor one. This phenomenon is associated with distinct histogenetic mechanisms: it may result from specific genetic mutations (e.g., AKT1 E17K in mucinous adenocarcinoma) that drive ductal epithelial differentiation into mucus-secreting cells, or from myoepithelial cells secreting glycosaminoglycans that form a myxoid stroma. Salivary gland tumors with abundant extracellular mucus include mucinous cystadenoma, sialadenoma papilliferum-like intraductal papillary tumors, mucinous myoepithelioma, pleomorphic adenoma with mucin-rich stroma, mucinous adenocarcinoma, low-grade mucoepidermoid carcinoma, mucin-rich salivary duct carcinoma and intestinal-type adenocarcinoma. The diagnosis of these tumors is complicated by the dual nature of extracellular mucus: while it is a defining feature of some entities, it can also obscure key diagnostic architectural features in others, leading to histological overlap and inconspicuous diagnostic areas. Given the frequent histological morphological overlap among these tumors, immunohistochemical findings and molecular characteristics have emerged as crucial differential diagnostic criteria. Core differential diagnostic points include the following: histologically, there must be meticulous identification of typical structures obscured by mucin (such as squamoid cells in mucoepidermoid carcinoma and apocrine features in salivary duct carcinoma); in immunohistochemical staining, CK20 is useful for distinguishing intestinal-type adenocarcinoma (positive) from mucinous adenocarcinoma (negative), while androgen receptor aids in differentiating salivary duct carcinoma (positive) from mucoepidermoid carcinoma (negative); and molecular testing plays a critical role in definitive diagnosis (e.g., the AKT1 E17K mutation for mucinous adenocarcinoma, MAML2 rearrangement for mucoepidermoid carcinoma, and MEF2C::SS18 fusion for microsecretory adenocarcinoma). This paper systematically summarizes the core pathological features and differential diagnostic points of mucin-rich salivary gland tumors, aiming to provide a practical reference for clinical pathological diagnosis.

Objective:To explore the clinical effect of applying above-knee medial free-style perforator propeller flap in repairing deep wounds in and around the knee joint.Methods:This study was a retrospective observational study. From December 2020 to October 2023, the Department of Burns and Cutaneous Surgery of the First Affiliated Hospital of Air Force Medical University admitted 13 patients who met the inclusion criteria and had deep burn wounds in and around the knee joints, including 9 males and 4 females, aged 16-70 years. After debridement, the sizes of skin and soft tissue defects ranged from 5.0 cm×4.0 cm to 9.0 cm×7.0 cm. A free-style perforator propeller flap was designed and harvested from the medial supragenicular region, using a perforator vessel as the pedicle. The size of the flap ranged from 6.0 cm×4.0 cm to 15.0 cm×7.0 cm. The larger paddle of the flap was used to repair the wound in and around the knee joint, while the smaller paddle assisted in closing the donor site wound. After surgery, the survival status of the flap, wound healing at the donor and recipient sites, and complications such as infection, effusion, and necrosis were observed. During the follow-up, the appearance, color, and texture of the flap as well as the wound healing, scar contracture, and knee joint mobility at the recipient site were observed, and the scar condition, sensory recovery, and complications at the donor site were recorded.Results:Postoperatively, all 13 patients achieved successful flap survival. In one case, infection occurred at the edge of the flap but healed after appropriate treatment including drainage and dressing changes, and the donor site wound healed well; the remaining 12 patients showed uneventful healing at both donor and recipient sites without complications. During follow-up of 5 to 24 months, all 13 patients exhibited natural appearance, normal skin color, soft texture, and good elasticity. The recipient site wounds healed well without scar contracture or deformity, with full range of motion in the knee joint. A mild linear scar remained at the donor site on the inner thigh, with normal sensory function and no numbness.Conclusions:The above-knee medial free-style perforator propeller flap demonstrates simple harvest with minimal trauma for repairing deep wounds in and around the knee joint, providing satisfactory aesthetic and functional outcomes at both donor and recipient sites.

Objective:In order to effectively educate students on tooth defect diseases and restoration techniques, the teaching and research team at the School of Stomatology of Qingdao University developed an integrated course operative dentistry. This course is specifically designed to align with the undergraduate curriculum reform requirements of "Three Early, Two Multiple and One Integration".Methods:The teaching practice of operative dentistry was conducted with the stomatology undergraduates of grade 2020 and 2021. The course group redesigned the curriculum by reorganizing teaching content, rebuilding teaching resources, reconstructing teaching mode, and reshaping the evaluation system. Evaluation of the curriculum design included test scores, satisfaction questionnaires, and teacher self-evaluation. Statistical analysis was performed using SPSS 27.0 software, including independent sample t-tests for numerical variables and Fisher's exact test or Wilcoxon rank sum test for categorical variables. Results:Through the integrated course learning, 92.68% (38/41) of the students of grade 2020 and 97.44% (38/39) of the students of grade 2021 can basically or completely master various dental defect repair schemes and understand the importance of preserving natural tooth. 82.93% (34/41) of the students of grade 2020 and 100.00% (39/39) of the students of grade 2021 could basically or completely master the key points of various dental defect restorations.Conclusions:Through the practice of teaching, it has been confirmed that the integrated course of operative dentistry is beneficial to students' mastering the knowledge and skills of dental defect diseases and their restoration in a more comprehensive way, and is conducive to the cultivation of clinical thinking, hands-on ability and the patient-centered, comprehensive problem-solving thinking, which is in line with the guidance on the innovation and development of medical education.

Objective:In order to effectively educate students on tooth defect diseases and restoration techniques, the teaching and research team at the School of Stomatology of Qingdao University developed an integrated course operative dentistry. This course is specifically designed to align with the undergraduate curriculum reform requirements of "Three Early, Two Multiple and One Integration".Methods:The teaching practice of operative dentistry was conducted with the stomatology undergraduates of grade 2020 and 2021. The course group redesigned the curriculum by reorganizing teaching content, rebuilding teaching resources, reconstructing teaching mode, and reshaping the evaluation system. Evaluation of the curriculum design included test scores, satisfaction questionnaires, and teacher self-evaluation. Statistical analysis was performed using SPSS 27.0 software, including independent sample t-tests for numerical variables and Fisher's exact test or Wilcoxon rank sum test for categorical variables. Results:Through the integrated course learning, 92.68% (38/41) of the students of grade 2020 and 97.44% (38/39) of the students of grade 2021 can basically or completely master various dental defect repair schemes and understand the importance of preserving natural tooth. 82.93% (34/41) of the students of grade 2020 and 100.00% (39/39) of the students of grade 2021 could basically or completely master the key points of various dental defect restorations.Conclusions:Through the practice of teaching, it has been confirmed that the integrated course of operative dentistry is beneficial to students' mastering the knowledge and skills of dental defect diseases and their restoration in a more comprehensive way, and is conducive to the cultivation of clinical thinking, hands-on ability and the patient-centered, comprehensive problem-solving thinking, which is in line with the guidance on the innovation and development of medical education.

Objective:To explore the clinical effect of applying above-knee medial free-style perforator propeller flap in repairing deep wounds in and around the knee joint.Methods:This study was a retrospective observational study. From December 2020 to October 2023, the Department of Burns and Cutaneous Surgery of the First Affiliated Hospital of Air Force Medical University admitted 13 patients who met the inclusion criteria and had deep burn wounds in and around the knee joints, including 9 males and 4 females, aged 16-70 years. After debridement, the sizes of skin and soft tissue defects ranged from 5.0 cm×4.0 cm to 9.0 cm×7.0 cm. A free-style perforator propeller flap was designed and harvested from the medial supragenicular region, using a perforator vessel as the pedicle. The size of the flap ranged from 6.0 cm×4.0 cm to 15.0 cm×7.0 cm. The larger paddle of the flap was used to repair the wound in and around the knee joint, while the smaller paddle assisted in closing the donor site wound. After surgery, the survival status of the flap, wound healing at the donor and recipient sites, and complications such as infection, effusion, and necrosis were observed. During the follow-up, the appearance, color, and texture of the flap as well as the wound healing, scar contracture, and knee joint mobility at the recipient site were observed, and the scar condition, sensory recovery, and complications at the donor site were recorded.Results:Postoperatively, all 13 patients achieved successful flap survival. In one case, infection occurred at the edge of the flap but healed after appropriate treatment including drainage and dressing changes, and the donor site wound healed well; the remaining 12 patients showed uneventful healing at both donor and recipient sites without complications. During follow-up of 5 to 24 months, all 13 patients exhibited natural appearance, normal skin color, soft texture, and good elasticity. The recipient site wounds healed well without scar contracture or deformity, with full range of motion in the knee joint. A mild linear scar remained at the donor site on the inner thigh, with normal sensory function and no numbness.Conclusions:The above-knee medial free-style perforator propeller flap demonstrates simple harvest with minimal trauma for repairing deep wounds in and around the knee joint, providing satisfactory aesthetic and functional outcomes at both donor and recipient sites.

Objective:To explore the feasibility and clinical effects of unilateral superior gluteal artery perforator propeller flap combined with contralateral centripetal advancement flap in repairing huge pressure ulcers in the sacrococcygeal region.Methods:The study was a retrospective observational study. From June 2020 to April 2023, 15 patients with stage Ⅳ pressure ulcers with sacrococcygeal defect area greater than 10.0 cm×10.0 cm who met the inclusion criteria were admitted to the First Affiliated Hospital of Air Force Medical University, including 8 males and 7 females, aged from 30 to 86 years. The pressure ulcers before debridement were all accompanied by different degree of infection and necrosis. Debridement and negative pressure sealing and irrigation treatment were performed in stage Ⅰ. After debridement, the skin and soft tissue defect area was 12.0 cm×10.5 cm to 20.0 cm×17.0 cm. After the wound bed infection was controlled, unilateral superior gluteal artery perforator propeller flap combined with contralateral centripetal advancement flap was used to repair the pressure ulcer wounds in stage Ⅱ. The perforator flap area was 12.0 cm×7.0 cm to 16.0 cm×10.5 cm. The donor area wound was sutured directly. After operation, the survival, complications, and wound healing of flap donor area were observed. During regular follow-up, the recurrence of pressure ulcers, the appearance and texture of the flap, and the scars in the donor site were observed.Results:After operation, 1 patient had fluid accumulation under the flap and survived after drainage and dressing change. The flaps of the other patients survived well without infection, local necrosis, and sinus formation under the flap. The wounds in the donor area healed well. All patients were followed up for more than 6 months, and there was no recurrence of pressure ulcers. The appearance of the flap was not bloated, the texture was soft, and the compression resistance and elasticity were good. The donor site wound healed well without obvious scar.Conclusions:The surgical method of repairing giant sacrococcygeal pressure ulcers with unilateral superior gluteal artery perforator propeller flap combined with contralateral centripetal advancement flap is simple and easy to operate. It can repair large defect area with the donor area being sutured directly, which is worthy of clinical promotion.

Objective To explore the effects of deletion of protein 4.1R on hepatocyte proliferation,apoptosis,and glycolysis and the molecular mechanisms.Methods A 4.1R-/-HL-7702 cell line was constructed using CRISPR/Cas9 technique,and with 4.1R+/+HL-7702 cells as the control,its proliferative capacity and cell apoptosis were assessed using CCK-8 assay,EdU-488 staining,flow cytometry and Annexin V-FITC/PI staining at 24,48,72 h of cell culture.The changes in glucose uptake,lactate secretion,ATP production and pH value of the culture supernatant of 4.1R-/-HL-7702 cells were determined.The mRNA expressions of the key regulatory enzymes HK2,PFKL,PKM2 and LDHA in glycolysis were detected with qRT-PCR,and the protein expressions of AMPK,p-AMPK,Raptor and p-Raptor were determined using Western blotting.Results Western blotting and sequencing analysis both confirmed the successful construction of 4.1R-/-HL-7702 cell line.Compared with the wild-type cells,4.1R-/-HL-7702 cells exhibited a lowered proliferative activity with increased cell apoptosis.The deletion of protein 4.1R also resulted in significantly decreased glucose uptake,lactate secretion and ATP production of the cells and increased pH value of the cell culture supernatant.qRT-PCR showed significantly decreased mRNA expressions of the key regulatory enzymes in glycolysis in 4.1R-/-HL-7702 cells.Compared with those in HL-7702 cells,the expression levels of AMPK and Raptor proteins were decreased while the expression levels of p-AMPK and p-Raptor proteins increased significantly in 4.1R-/-HL-7702 cells.Conclusion Deletion of protein 4.1R in HL-7702 cells results in reduced proliferative capacity,increased apoptosis and suppression of glycolysis,and this regulatory mechanism is closely related with the activation of the downstream AMPK-mTORC1 signaling pathway.

Objective To explore the effects of deletion of protein 4.1R on hepatocyte proliferation,apoptosis,and glycolysis and the molecular mechanisms.Methods A 4.1R-/-HL-7702 cell line was constructed using CRISPR/Cas9 technique,and with 4.1R+/+HL-7702 cells as the control,its proliferative capacity and cell apoptosis were assessed using CCK-8 assay,EdU-488 staining,flow cytometry and Annexin V-FITC/PI staining at 24,48,72 h of cell culture.The changes in glucose uptake,lactate secretion,ATP production and pH value of the culture supernatant of 4.1R-/-HL-7702 cells were determined.The mRNA expressions of the key regulatory enzymes HK2,PFKL,PKM2 and LDHA in glycolysis were detected with qRT-PCR,and the protein expressions of AMPK,p-AMPK,Raptor and p-Raptor were determined using Western blotting.Results Western blotting and sequencing analysis both confirmed the successful construction of 4.1R-/-HL-7702 cell line.Compared with the wild-type cells,4.1R-/-HL-7702 cells exhibited a lowered proliferative activity with increased cell apoptosis.The deletion of protein 4.1R also resulted in significantly decreased glucose uptake,lactate secretion and ATP production of the cells and increased pH value of the cell culture supernatant.qRT-PCR showed significantly decreased mRNA expressions of the key regulatory enzymes in glycolysis in 4.1R-/-HL-7702 cells.Compared with those in HL-7702 cells,the expression levels of AMPK and Raptor proteins were decreased while the expression levels of p-AMPK and p-Raptor proteins increased significantly in 4.1R-/-HL-7702 cells.Conclusion Deletion of protein 4.1R in HL-7702 cells results in reduced proliferative capacity,increased apoptosis and suppression of glycolysis,and this regulatory mechanism is closely related with the activation of the downstream AMPK-mTORC1 signaling pathway.

The deep tissue defects of extremities are prone to cause the exposure of tendons, blood vessels, nerves, and bones, which are commonly repaired with free flaps in clinical practice. However, for special parts such as fingers, toes, posterior ankles, anterior tibias, and dorsum of feet, the appearances are usually bulky after being repaired with free flaps and need lipectomy operations, which bring great physiological, psychological, and economic burden to patients. As the fascia flap is soft and thin with reliable blood supply and strong anti-infection ability, the free fascia flap combined with skin grafting offers some advantages in repairing the above-mentioned wounds. However, its clinical application is severely limited due to the complexity of surgical operation and the difficulty in observing blood supply after operation. In recent years, our team has carried out a lot of work and accumulated rich experience in repairing deep tissue defects of special parts of extremities with free superficial temporal fascia flap/anterolateral femoral fascial flap combined with skin grafting. From the clinical perspective, this paper mainly introduces the anatomy and harvesting method of free superficial temporal fascia flap/anterolateral femoral fascial flap, as well as the advantages, difficulties, and precautions of clinical application, for reference of peers.

Objective:To evaluate the effect of goal-oriented online and offline mixed teaching method on the trainees of burn operating room.Methods:From June 2019 to June 2020, 42 trainees of burn operating room in our hospital were selected for the randomized parallel trial, and they were randomly divided into two groups, routine group and research group. The routine group adopted the conventional online and offline mixed teaching method, while the research group adopted the goal-oriented online and offline mixed teaching method. The internship time of both group lasted for 1 month. Results and excellent rates, self-confidence and burn surgery skills evaluation before and after the internship, and satisfaction with the internship mode were compared between the two groups. SPSS 19.0 was used for t test and chi-square test. Results:The results and excellent and good rates of theoretical examination and practical examination in the research group were higher than those of the routine group. The scores of self-confidence, choice of operation mode, innovation and optimization of operation, control of operation complications and treatment of intraoperative emergencies in the two groups after internship were higher than those before internship, and the above scores of research group were higher than those of the routine group after internship. The satisfaction scores of the students on enhancing self-confidence, and improving operational ability, learning initiative and learning efficiency in the research group were significantly higher than those in the routine group ( P < 0.05). Conclusion:Goal-oriented online and offline mixed teaching method on trainees in burn operating room can not only improve the examination results, enhance their confidence and burn surgery skills, but also achieve their satisfaction.