BACKGROUND:Some scholars have prepared zein/chitosan composite membrane based on blending methods, and preliminary evaluation ofitsphysical and chemical properties showsthat chitosan partly improvesthe mechanical properties and hydrophilic properties of zein. Therefore, zein/chitosan composite membrane presumably has good cytocompati bility, which is beneficial to osteogenic differentiation of bone marrow mesenchymal stem cels.
OBJECTIVE:To explore the effect of zein/chitosan composite membrane on the differentiation of bone marrow mesenchymal stem cels into osteoblasts and its feasibility asabone tissue-engineered material.
METHODS:With 60% acetic acid as solvent, zein/chitosan composite membrane was prepared by blending and casting method. The structure and physicochemical properties of the composite membrane were investigated by Fourier transform infrared spectroscopy, tensile testing, water absorption testing and scanning electron microscopy. And the cytocompatibility of the membrane was evaluated byin vitrocel cufture. Besides,bone marrow mesenchymal stem celsfrom Sprague-Dawley ratwere isolatedvia adherence screening method, andthe effects of thecompositemembrane on theosteogenic differentiation ofthese celswere observedby scanning electron microscopy, fluorescent labeling and alkaline phosphatase assay.
RESULTS AND CONCLUSION:The tensile strength, water absorption and hydrophilicity of the films were improved with the chitosan increased; chitosan could promote cel proliferation indicating the good cytocompatibility of the composite films. Moreover, osteogenic induction occurredin bone marrow mesenchymal stem cels cultured on the compositem embrane, and with an increase of chitosan, the induction was promoted. In conclusion, zein/chitosan composite membrane can be applied widely in the field of bone tissue engineering.

Objective To evaluate the diagnostic value of 99Tcm-MDP SPECT/CT in the diagnosis of lumbar spondylolysis.Methods A total of 58 patients (28 males,30 females,average age 61.3 years) who underwent bone scan and SPECT/CT because of low back pain from January 2012 to May 2014 were retrospectively evaluated.The final diagnosis was based on comprehensive results of SPECT/CT and followup.The diagnostic sensitivity and accuracy of SPECT,CT and SPECT/CT images were calculated and x2 test was performed to analyze the data.Results Twenty-eight patients were diagnosed as lumbar spondylolysis.The diagnostic sensitivities of SPECT,CT and SPECT/CT were 53.6％ (15/28),78.6％ (22/28) and 100％(28/28).The diagnostic accuracies of SPECT,CT and SPECT/CT were 48.3％ (28/58),89.7％ (52/58) and 93.1％(54/58).SPECT/CT was proved to be more accurate than SPECT(x2=28.13,P＜ 0.05).Conclusion SPECT/CT bone scan may detect lumbar spondylolysis in early stage.

Objective:To investigate the correlation of hepatocellular carcinoma (HCC) classified by contrast-enhanced ultrasound (CEUS) Liver Imaging Data and Report System (LI-RADS) with differentiation degree and Ki-67 index.Methods:A multicenter, retrospective study was conducted.The clinical and CEUS imaging data of 208 patients with 208 HCC lesions from December 2017 to December 2020 in China CEUS database were included and analyzed. According to the CEUS LI-RADS version 2017 proposed by the American College of Radiology, the HCC was classified. The diagnosis and pathological information of all lesions were confirmed by pathology. The differentiation degree of HCC and the distribution of Ki-67 index in different LI-RADS categories were evaluated, and their correlation was analyzed.Results:The degree of differentiation and Ki-67 index among HCC of different CEUS LI-RADS were statistically significant ( P<0.001, P=0.009). LI-RADS M HCC was more likely to be poorly differentiated and showed a higher Ki-67 index. The category of LI-RADS was positively correlated with the degree of tumor differentiation (tau-b=-0.250, P<0.001) and the Ki-67 index (tau-b=0.178, P=0.002), that is, the higher the category of LI-RADS, the lower differentiation degree and the higher the Ki-67. Conclusions:The CEUS LI-RADS classification of HCC is correlating with the degree of differentiation and Ki-67 index.