Epigenetic mechanisms play a crucial role in the development and progression of nonalcoholic fatty liver disease （NAFLD）， especially among lean individuals. The research on related epigenetic mechanisms has provided new clues and directions for revealing the underlying causes and treatment strategies of NAFLD. This article introduces the role of epigenetics in the development and progression of NAFLD among lean individuals in recent years， analyzes the latest research advances in the epigenetics of NAFLD in this population， and briefly describes the basic concepts of epigenetics， including DNA methylation， histone modifications， and non-coding RNA regulation. This article also discusses how epigenetic alterations impact the pathogenesis， disease progression， and treatment strategies of NAFLD in lean individuals.

OBJECTIVES: With the increasing detection rate of lung nodules, the qualitative problem of lung nodules has become one of the key clinical issues. This study aims to evaluate the value of combining dynamic contrast-enhanced (DCE) MRI based on time-resolved imaging with interleaved stochastic trajectories-volume interpolated breath hold examination (TWIST-VIBE) with T₁ weighted free-breathing star-volumetric interpolated breath hold examination (T₁WI star-VIBE) in identifying benign and malignant lung nodules. METHODS: We retrospectively analyzed 79 adults with undetermined lung nodules before the operation. All nodules of patients included were classified into malignant nodules (n=58) and benign nodules (n=26) based on final diagnosis. The unenhanced T₁WI-VIBE, the contrast-enhanced T₁WI star-VIBE, and the DCE curve based on TWIST-VIBE were performed. The corresponding qualitative [wash-in time, wash-out time, time to peak (TTP), arrival time (AT), positive enhancement integral (PEI)] and quantitative parameters [volume transfer constant (Ktrans), interstitium-to-plasma rate constant (Kep), and fractional extracellular space volume (Ve)] were evaluated. Besides, the diagnostic efficacy (sensitivity and specificity) of enhanced CT and MRI were compared. RESULTS: There were significant differences in unenhanced T₁WI-VIBE hypo-intensity, and type of A, B, C DCE curve type between benign and malignant lung nodules (all P<0.001). Pulmonary malignant nodules had a shorter wash-out time than benign nodules (P=0.001), and the differences of the remaining parameters were not statistically significant (all P>0.05). After T₁WI star-VIBE contrast-enhanced MRI, the image quality was further improved. Compared with enhanced CT scan, the sensitivity (82.76% vs 80.50%) and the specificity (69.23% vs 57.10%) based on MRI were higher than that of CT (both P<0.001). CONCLUSIONS T₁WI star-VIBE and dynamic contrast-enhanced MRI based on TWIST-VIBE were helpful to improve the image resolution and provide more information for clinical differentiation between benign and malignant lung nodules.
Adult ; Humans ; Retrospective Studies ; Magnetic Resonance Imaging ; Plasma ; Tomography, X-Ray Computed ; Lung

Objective To set up a living mice colonoscopy platform to establish an orthotopic model of colorectal cancer in mice under direct vision,and to observe its biological behavior such as metastasis.Methods Eighteen-week-old male C57/BL mice were anesthetized,and the intestinal lumen of the mice was examined by a self-developed living mice colonoscopy and Olympus URF-P5 ureteroscopy,respectively.The imaging effects of the two methods were compared.Human colon cancer HT-29 cells were injected into the colonic mucosa of BALB/c-nu mice under direct vision.The colonoscopy was performed on the 3rd,7th and 15th day after the injection to observe the tumor formation in the intestinal lumen.The mice were sacrificed when the body weight decreased significantly or cachexia appeared,and then the abdominal cavity was examined including the tumor formation and metastasis.Results The self-developed living mice colonoscopy platform can provide clear vision of enteric cavity,and no mice died in the colonoscopy examination.In vivo subcutaneous injection of HT-29 cells in mice was performed with a perforation rate of 15％,a mortality rate of 33.3％,a tumor formation rate of 62.5％,an abdominal metastasis rate of 60％,a liver metastasis rate of 25％,and an abdominal wall transfer rate of 25％.Conclusion The self-developed mice colonoscopy platform can be used for the study of colorectum in living mice.The imaging effect is no less than that of Olympus URF-P5 ureteroscopy.In addition,an orthotopic colorectal cancer model can be established by this platform combing with submucosal injection technology.

Objective To investigate the expression of the Kv3 .4 protein and Kv3 .4 mRNA in various stages of oral carcino‐genesis .Methods The expression of Kv3 .4 protein and Kv3 .4 mRNA were detected by immunohistochemistry (SP method) and RT‐PCR technique respectively in the oral carcinogenesis of SD rat which were induced by 4NQO .Results With the aggravation of the epithelial dysplasia ,Kv3 .4 protein and Kv3 .4 mRNA expression increased gradually .They were strongly positive in oral squa‐mous cell carcinoma .Conclusion The expression of Kv3 .4 protein and Kv3 .4 mRNA levels increased consistently with the aggra‐vation of the epithelial dysplasia .