Objective: To investigate the clinicopathological characteristics and diagnostic-therapeutic strategies of oncocytic mucoepidermoid carcinoma (OMEC) of the parotid gland, and to enhance awareness of this rare variant among clinicians and pathologists. Methods: The clinical data, imaging findings, histopathological features, immunophenotype, and molecular characteristics of two patients with parotid OMEC were retrospectively analyzed, and the relevant literature was reviewed. Results: Case 1 was a 50-year-old man who presented with a painless mass behind the right earlobe for more than 2 years. The patient underwent extended parotidectomy with preservation of the facial nerve. Histopathological examination revealed that the tumor was predominantly composed of oncocytic cells with a small proportion of mucous cells. Immunohistochemically, the tumor cells were partially positive for cytokeratin 5/6, cytokeratin 7, and P63. Special staining with alcian blue, periodic acid-Schiff, and phosphotungstic acid hematoxylin yielded positive results. The diagnosis of right parotid OMEC was established. No recurrence or metastasis was observed during a 1 year follow-up. Case 2 was a 61-year-old man with a 3-month history of a mass beneath the left ear. After partial parotidectomy at an outside institution, pathological consultation at the Stomatological Hospital of Jilin University demonstrated that the tumor consisted almost entirely of oncocytic cells, exhibited infiltrative growth, and lacked typical mucous, epidermoid, and intermediate cells. Fluorescence in situ hybridization confirmed positive mastermind-like transcriptional activator 2 (MAML2) gene rearrangement, establishing the diagnosis of left parotid OMEC. The patient subsequently underwent total parotidectomy with preservation of the facial nerve, and no recurrence was detected during a short-term 3 months follow-up. A review of the literature indicated that OMEC most commonly arises in the parotid gland and is generally a low-grade malignancy with favorable prognosis. When tumors are composed exclusively of oncocytic cells, exhibit minimal cytological atypia, and lack the classical cellular components of mucoepidermoid carcinoma, they are highly prone to misdiagnosis as oncocytoma, nodular oncocytic hyperplasia, or other benign oncocytic lesions. Accurate differential diagnosis relies on recognition of infiltrative growth patterns, supportive immunophenotypic markers (e.g., P63 positivity), and detection of characteristic MAML2 gene rearrangement. Complete surgical excision remains the treatment of choice. Conclusion OMEC dominated by oncocytic cells carries a high risk of clinical misdiagnosis. Integrating the assessment Conclusion OMEC dominated by oncocytic cells carries a high risk of clinical misdiagnosis. Integrating the assessment of infiltrative histopathological features with immunohistochemistry and molecular detection of MAML2 rearrangement is crucial for accurate diagnosis, appropriate assessment of tumor behavior, and optimal surgical decision making.

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.

Antibodies against LSP in the sera of 168 patients with various types of viral hepatitis were determined with SPA-RIA. The sera of another group of 178 patients (109 of them were from the first group) with viral hepatitis were studied with ELISA for the same antibodies, which were further divided into three categories, that is, IgG, IgM and IgA classes. The results of 109 patients examined with both of the two methods, indicated that anti-LSP antibodies measured by SPA-RIA might mainly represent anti-LSP IgG class. It was found that circu-lating anti-LSP antibodies could easily be detected in most patients with either acute or chronic hepatitis. After analyzing the-results, the authors suggest that the humoral immune response against LSP might not be the sole initiating factor in the pathogenesis of viral hepatitis, they are more likely the result of the antigen variation of the injured liver cells.

A specific and sensitive radioimmunoprecipitation method was used to detect antibody against liver-specific membrane lipoprotein (LSP) in the sera of 182 patients with viral hepatitis, HBsAg chronic carriers and liver cirrhosis and 40 patients with other diseases as control. The results showed that the highest frequency of anti-LSP was noticed in the patients with severe hepatitis (15 out of 16 cases, 93.8%), and in the patients with chronic active hepatitis, acute viral hepatitis, chronic persistent hepatitis, cirrhosis and other diseases and in the HBsAg chronic carriers the incidences were 83.6%(41/49 cases), 66.2% (43/65), 63.6%(14/22), 55.0%(11/20), 5%(2/40) and 10%(1/10) respectively. The frequencies of anti-LSP in the patients with various types of viral hepatitis were significantly higher than those in the HBsAg chronic carriers and in the patients with other diseases (P