Objective To explore the effect of an electromagnetic field (EMF) on the viability,proliferation and osteogenic differentiation of rats' bone mesenchymal stem cells (rBMSC).Methods Sinusoidal 1mT EMFs of 10 Hz,30 Hz,50 Hz and 70 Hz were administered to rBMSC for 2 hours per day during 2 weeks of cultivation.The cell viability was analyzed using live/dead assays.The cells' DNA was quantified to evaluate cell proliferation.Von Kossa staining was performed to study the mineralization of the extracellular matrix.The enzyme linked immunosorbent assay (ELISA) and immunohistological staining were employed to observe the synthesis of osteocalcin (OC) and bone morphogenetic protein-2 (BMP-2).Results Cell viability decreased under exposure to the 50 Hz and 70 Hz fields.The proliferation of rBMSC was elevated significantly in the 10 Hz EMF-treated group.The expression OC and BMP-2 was elevated after two weeks of 50 Hz EMF stimulation.Moreover,the mineralization of the extracellular matrix was found to be enhanced after 50 Hz EMF exposure.Conclusion Exposure to a 1 mT EMF has different effects on the viability,proliferation and osteogenic differentiation of rBMSC depending on the frequency.The data provide practical guidance for applying electromagnetic fields in bone regenerative medicine.

Colorectal cancer is one of the most common malignant tumors of digestive system.There are significant differences between young patients and other ages in aspects of the disease features, biological characteristics, risk factors, clinical treatment and prognosis, etc.And the analysis of young colorectal cancer patients′ characteristics can provide new ideas for clinical treatment.

Objective:To investigate the stiffness characteristic of triple-negative human breast cancer at different size in a implantation nude female mice model using shear wave elastography(SWE) and to compare the clinical pathologic features of tumors with elasticity variables.Methods:Human breast cancer MDA-MB-231 cells were injected into 30 nude female mice and 27 transplanted tumors were successfully found in nude female mice. Ultrasound and SWE were longitudinally performed on maximum diameter plane of 21 tumours in 21 nude mice. The elastic parameters of maximal elasticity(Emax), mean elasticity (Emean) and standard deviation of elasticity(Esd) were recorded. The mice were divided into 3 groups according to the tumor size. They were group A with tumor size less than or equal to 5 mm, group B with tumor size greater than 5 mm and less than or equal to 10 mm, group C with tumor size larger than 10 mm and smaller than or equal to 15 mm. Compared with pathology, the relationships between Ki67 of transplanted tumor and elastic parameters were analyzed.Results:As the transplanted tumors increased, the values of Emax, Esd, Ki67 all increased. The lesions maximal size, Emax, Esd, Ki67 were significant higher in group B ( P<0.001, P=0.006, P=0.002, P=0.026) and group C ( P<0.001, P<0.001, P<0.001, P=0.028) than group A. The other parameters were not significantly different among the groups(all P>0.05). The size of transplanted tumors was significantly and positively correlated with Emax ( rs=0.673, P=0.001), Esd ( rs=0.661, P=0.001), and Ki67 ( rs=0.509, P=0.018). Conclusions:SWE Emax and Esd can reflect the tumor tissue stiffness change and biological activity during the tumor growth.

Objective To study the effects of electromagnetic field (EMF) exposure on osteoporosis in ovariectomized mice. Methods Sixty 8-week-old female Kunming mice were divided into four groups at random: a sham operation group (group A), an ovariectomized group (group B), an EMF and ovariectomized group (group C) and a nilestriol and ovariectomized group (group D). Bilateral ovariectomies were performed on all mice except those in group A. The mice of group C were exposured to a 15 Hz, 1.0 mT electromagnetic field. The mice of group D were given at nilestriol 1.5 mg/kg/week. The bone mineral density (BMD) of the lumbar vertebrae was measured before the mice were sacrificed at the 12th week. Blood specimens were collected every two weeks to measure the ac-tivity of alkaline phosphatase (ALP) and the concentration of bone gamma-carboxyglutamic-acid-containing proteins (BGP), calcium and estradiol in the serum. Histological sections were taken to examine and analyze the changes in bone trabeculae in the lumbar vertebrae after 6 and 12 weeks. Results EMF at 15 Hz and 1.0 mT intensity signifi-cantly increased the activity of ALP and the concentrations of BGP and calcium in the serum. In addition, the absorp-tion of bone trabeculae in the lumbar vertebrae was significantly restrained. Conclusions EMF at 15 Hz and 1.0 mT can restrain the development of osteoporosis in ovariectomized mice.

Objective To study the effects of an electromagnetic field (EMF) on the expression of fibro-blast growth factor (FGF-2) and it' s receptor (FGFR-2) mRNA in rat bone marrow mesenchymal stem cells (BMSCs) in vitro. Methods Rat BMSCs were isolated and cultured in vitro. The subcultured cells were divided into different groups to be EMF stimulated at 1.0 mT. The expression of FGF-2 and FGFR-2 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). Results Different frequencies and durations of 1.0 mT EMF exposure induced FGF-2 and FGFR-2 mRNA expression in comparison to blank controls. The expression of FGF-2 mRNA reached a peak after stimulation at 15 Hz for 10 min, 50 Hz for 60 min and 75 Hz for 30 min. And the expression of FGFR-2 mRNA reached a peak after 30 minutes at all frequencies. At 1.0 mT with 30 min exposure, the expression of FGF-2 mRNA peaked after 50 Hz stimulation, and the expression of FGFR-2 mRNA peaked after stimulation at 75 Hz. Conclusions Moderate EMF stimulation can significantly increase the expression of FGF-2 and FGFR-2 mRNA in rat BMSCs in vitro.

Objective To study the effects of pulsed electromagnetic field (PEMF) in promoting tibia and fibula fracture healing in rats. Methods Thirty rats were divided randomly into two groups after establishing the animal model of artificial tibia and fibula fracture: a PEMF treated group and a control group. Radiographs were taken immediately postoperatively and once a week thereafter until being sacrificed after week 5. The blood was sampled to measure the activity of alkaline phosphatase (ALP) and the concentration of bone gamma-carboxyglutamic-acid-con-taining proteins (BGP), calcium and phosphate in serum once a week, respectively. Histological sections were taken at weeks 3 and 5 to observe the pathological change of bony callus. Results PEMF of 15 Hz and 1.0 mT could sig-nificantly increase the amount of bony callus, significantly increase the amount of bony callus, promote the disappea-ring of fracture lines and the appearance of endochondral ossification and mature bone trabecula. The amount of colla-gen in bony callus raised and the process of callus moulding accelerated in PEMF treated group. In addition, the ac-tivity of ALP(P<0.04) and the concentration of BGP(P<0.05) in serum increased. Conclusions The PEMF of 15 Hz and 1.0 mT can obviously promote fracture healing of tibia and fibula in rats.

Objective:To compare the efficacies of 3D-printed navigation template assisted and freehand posterior cervical screw fixation of atlantoaxial fractures.Methods:A retrospective cohort study was used to analyze the clinical data of 22 patients with atlantoaxial fractures admitted to Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from September 2018 to December 2020. There were 13 males and 9 females, with age range of 26-68 years [(50.7±11.9)years]. All the patients underwent posterior atlantoaxial pedicle screw internal fixation and fusion, among whom 11 patients admitted from November 2019 to December 2020 were assisted with 3D printed navigation templates for the placement of pedicle screws (assisted group) and 11 patients admitted from September 2018 to October 2019 used the traditional way of placing pedicle screws (freehand group). A total of 88 pedicle screws were implanted, with 44 pedicle screws in each group. The operation time, intraoperative blood loss, and intraoperative fluoroscopy frequency were compared between the two groups. The visual analogue score (VAS) and Japanese Orthopedic Society (JOA) score were also compared before operation, at 3 days, 3 months, 6 months postoperatively and at the last follow-up. The accuracy of pedicle screw placement was evaluated according to the Kawaguchi classification, and complications were observed.Results:All the patients were followed up for 24-30 months [(26.4±1.8)months]. The assisted group showed the operation time of (87.3±19.5)minutes and the intraoperative fluoroscopy frequency of (6.4±1.4)times, decreased compared with the freehand group [(115.5±23.0)minutes, (10.3±1.7)times] [(all P<0.01). However, no significant difference was observed in the intraoperative blood loss between the two groups ( P>0.05). Both groups demonstrated comparable VAS and JOA score before operation, at 3 days, 3 months, 6 months postoperatively and at the last follow-up (all P>0.05). Furthermore, the assisted group exhibited a significantly higher accuracy of pedicle screw placement [95.5% (42/44)] compared with the freehand group [79.5% (35/44)] ( P<0.05). Notably, there were no intraoperative vertebral artery injury, spinal cord injury, or cerebrospinal fluid leakage in either group, or internal fixation loosening, fracture, nonunion in either group after operation. Conclusion:Compared with freehand posterior cervical screw placement, 3D-printed navigation template-assisted posterior cervical pedicle screw fixation of atlantoaxial fracture can shorten the operation time, reduce the intraoperative fluoroscopy frequency, and improve the accuracy of screw placement.

The IMbrave 150 study opened the door of immunotherapy combined with targeted therapy, and then the data of ORIENTAL-32, a Phase Ⅲ clinical trial for Chinese patients, was released, which confirmed the efficacy of immunotherapy combined with targeted therapy, especially significant survival benefits in Chinese patients. At present, there are many ongoing studies on PD-1/PD-L1 inhibitors combined with small-molecule tyrosine kinase inhibitors, and their corresponding early data provide a considerable objective response rate, which provides an opportunity for conversion therapy/sequential therapy for hepatocellular carcinoma in different stages and courses, as well as a basis for further exploration of neoadjuvant/adjuvant therapy. Combined immunotherapy has entered the era of version 3.0, in which reasonable local therapy can be implemented at different stages in combination with targeted drugs. However, there are still no accurate predictive indicators for efficacy, and it requires comprehensive consideration of the features such as the natural course of the disease, clinicopathological parameters, genomics, and radiomics. Compared with single-drug immunotherapy or single-drug targeted therapy, immunotherapy combined with targeted therapy had a relatively complex spectrum of adverse reactions and difficult identification of correlation, and whole-process management, comprehensive judgment, and timely treatment should be performed within the framework of multidisciplinary team.