BACKGROUND:Changes in skeletal muscle mass have been indicated in studies addressing the effects of low-frequency pulsed magnetic fields on the structure and morphology of the skeletal muscle,but no relevant studies have been conducted on the morphologic changes that occur after chronic exposure to the low-frequency pulsed magnetic field. OBJECTIVE:To observe the effects of chronic exposure to low-frequency pulsed magnetic fields on the maximal voluntary contraction and morphologic indicators of the quadriceps muscle of the leg,thereby providing a reference of muscle morphologic changes for the use of this technique as a strategy for muscle function improvement. METHODS:Seventy healthy subjects were recruited and randomly divided into a test group that received magnetic field stimulation and a control group that underwent sham treatment,with 35 subjects in each group,and the total duration of the trial was 4 weeks.The test group underwent low-frequency pulsed magnetic stimulation for 15 minutes every 48 hours,while the control group underwent sham treatment,with the same intervention interval and duration as the test group.After 4 weeks of intervention,changes in the maximum voluntary contraction value of the quadriceps muscle in different groups were observed,and B-mode ultrasonography was utilized as a means of assessment to observe changes in muscle thickness,muscle cross-sectional area,and pinnation angle indexes. RESULTS AND CONCLUSION:After 4 weeks of chronic exposure to low-frequency pulsed magnetic fields,68 subjects completed the test.The maximum voluntary contraction value of the quadriceps muscle in the test group increased significantly(P=0.000),and the increment was significantly higher than that of the control group(P=0.008).Three indexes related to muscle morphology in the test group were significantly higher than the pre-test values(P=0.000),while in the control group,muscle thickness showed a significant reduction(P=0.020),there was no significant change in the pinnation angle,but a significant increase in the cross-sectional area(P=0.000).Intergroup comparisons revealed that the three indicators related to muscle morphology,including muscle thickness(P=0.012),pinnation angle(P=0.003),and cross-sectional area(P=0.049),were significantly higher in the test group than in the control group.The above data confirmed that the maximum voluntary contraction of the quadriceps muscle was significantly increased in healthy adults after 4 weeks of chronic exposure to the low-frequency pulsed magnetic field,and significant increases in the three muscle morphometric indices of muscle thickness,cross-sectional area,and pinnation angle were observed in the test group,providing a basis of muscle tissue morphology for the use of this technique as an exercise alternative and medical treatment strategy for muscle improvement.

Objective To investigate the function of the glutamic-oxaloacetic transaminase 2(GOT2)gene in acute myeloid leukemia cells.Methods ShRNAs targeting at GOT2 were constructed to suppress GOT2 expression in the THP-1 human monocytic leukemia cell line.GOT2 mRNA level was measured by RT-qPCR,and GOT2 protein ex-pression was measured by Western blot.Intracellular free amino acid level was quantified using colorimetric assays.The impact of GOT2 knockdown in THP-1 cell function was evaluated through cell viability(CCK-8 assay)and ap-optosis(flow cytometry).Results After GOT2 knockdown,both GOT2 mRNA and protein were significantly de-creased in THP-1 cells(P＜0.05).Compared to the control group,GOT2 knockdown did not affect intracellular glutamate levels(P＞0.05),but led to a marked decrease in aspartate level(P＜0.05).GOT2 knockdown signifi-cantly impaired THP-1 cell viability,inhibited cell proliferation(P＜0.05)and promoted apoptosis(P＜0.05).Conclusions Down regulation of GOT2 significantly decreases intracellular aspartate level in acute myeloid leukemia cells,impairs cellular viability and induces apoptosis,which suggests that GOT2 may play a key role in the regula-tion of amino acid metabolism in acute myeloid leukemia.

This study aims to determine the nephrotoxic effects of 3-monochloropropanel-1,2-diol(3-MCPD)on female and male SD rats.A nephrotoxicity model was established by gavage of dif-ferent doses of 3-MCPD,and 80 SD rats were randomly divided into four groups:the control group(0 mg/kg 3-MCPD),low-dose group(15 mg/kg 3-MCPD),medium-dose group(30 mg/kg 3-MCPD),high-dose group(60 mg/kg 3-MCPD),with half female and half male.The body mass and food intake of the rats were recorded weekly,and the urine and blood and kidney tissues were col-lected after 28 consecutive days of gavage,and the blood erythrocyte count(WBC),white blood cell count(RBC),hemoglobin(HGB),erythrocyte-compaction-transfer-value(HCT),creatinine(CREA),serum urea nitrogen(BUN),and the indexes of blood phosphorus(P)and calcium(Ca)were detected;the level of kidney injury molecule(KIM-1)was measured by ELISA kit;the renal pathological changes was observed by histopathology method;and transcriptome sequencing was used to analyze differential genes in female and male rats.The results showed that 3-MCPD did not significantly affect the growth of male rats,but high doses significantly reduced the weight and food intake of female rats.The high-dose group of 3-MCPD caused a significant decrease in RBC,HGB,and HCT levels in both male and female rats,resulting in a significant increase in KIM-1 and P,and a significant decrease in Ca,but only a significant increase in CREA and BUN in female rats.Histopathology showed that in the high-dose group of male rats,only mild renal tubular dilation,epithelial cell edema,and clear tubular type were observed in the kidneys,while in female rats,a large number of renal sacs,clear tubular type,and interstitial inflammatory cells with fibrosis were observed in the kidneys.Transcriptome sequencing showed 1 712 differentially expressed genes in the high-dose group of female rats and 1 153 differentially expressed genes in the high-dose group of male rats.KEGG enrichment analysis showed that both male and female rats in the high-dose group experienced oxidative stress and cell apoptosis,but 3-MCPD may also participate in the process of kidney damage in females by inhibiting autophagy and inducing iron death pathways.The above results indicate that high-dose 3-MCPD has a more significant nephrotoxic effect on fe-male rats.

Objective:To observe therapeutic effect of catalpol on Sj?gren's syndrome(SS)model mice and explore further mechanism through vitro experiments.Methods:Eight-week-old NOD mice were given catalpol 100 mg/kg by gavage for 8 weeks.Serum levels of IFN-γ and IL-17 were measured.Pathological of salivary glands were observed.lnc-NONHSAT071210 shRNA trans-fected salivary gland epithelial cell lines were treated with 50 μmol/L catalpol,and expression of lnc-NONHSAT071210 was detected.Cells were intervented by 10 ng/ml IFN-γ,lnc-NONHSAT071210 shRNA and catalpol treatment for 72 h,cell proliferation and expressions of IL-17 and IFN-γ were detected.Results:Compared with control group,expressions of IFN-γ and IL-17 were decreased(P<0.05),pathology of salivary gland showed that infiltration of lymphocytes was reduced and destruction of gland structure was significantly reduced in catalpol group.Compared with IFN-γ intervention group,catalpol treatment significantly increased prolifera-tion of salivary gland epithelial cells,and decreased expressions of IFN-γ and IL-17(P<0.05).After catalpol treatment,expression of lnc-NONHSAT071210 was decreased(P<0.05).Moreover,IFN-γ and IL-17 expressions were decreased by catalpol and lnc-NONH-SAT071210 shRNA co-treatment(P<0.01).Conclusion:Catalpol can inhibit expressions of inflammatory cytokines in serum and infiltration of lymphocyte in salivary gland of SS model mice,and inhibit salivary gland ductal fine epithelial inflammatory response and progression of SS by regulating lnc-NONHSAT071210.

This study aims to determine the nephrotoxic effects of 3-monochloropropanel-1,2-diol(3-MCPD)on female and male SD rats.A nephrotoxicity model was established by gavage of dif-ferent doses of 3-MCPD,and 80 SD rats were randomly divided into four groups:the control group(0 mg/kg 3-MCPD),low-dose group(15 mg/kg 3-MCPD),medium-dose group(30 mg/kg 3-MCPD),high-dose group(60 mg/kg 3-MCPD),with half female and half male.The body mass and food intake of the rats were recorded weekly,and the urine and blood and kidney tissues were col-lected after 28 consecutive days of gavage,and the blood erythrocyte count(WBC),white blood cell count(RBC),hemoglobin(HGB),erythrocyte-compaction-transfer-value(HCT),creatinine(CREA),serum urea nitrogen(BUN),and the indexes of blood phosphorus(P)and calcium(Ca)were detected;the level of kidney injury molecule(KIM-1)was measured by ELISA kit;the renal pathological changes was observed by histopathology method;and transcriptome sequencing was used to analyze differential genes in female and male rats.The results showed that 3-MCPD did not significantly affect the growth of male rats,but high doses significantly reduced the weight and food intake of female rats.The high-dose group of 3-MCPD caused a significant decrease in RBC,HGB,and HCT levels in both male and female rats,resulting in a significant increase in KIM-1 and P,and a significant decrease in Ca,but only a significant increase in CREA and BUN in female rats.Histopathology showed that in the high-dose group of male rats,only mild renal tubular dilation,epithelial cell edema,and clear tubular type were observed in the kidneys,while in female rats,a large number of renal sacs,clear tubular type,and interstitial inflammatory cells with fibrosis were observed in the kidneys.Transcriptome sequencing showed 1 712 differentially expressed genes in the high-dose group of female rats and 1 153 differentially expressed genes in the high-dose group of male rats.KEGG enrichment analysis showed that both male and female rats in the high-dose group experienced oxidative stress and cell apoptosis,but 3-MCPD may also participate in the process of kidney damage in females by inhibiting autophagy and inducing iron death pathways.The above results indicate that high-dose 3-MCPD has a more significant nephrotoxic effect on fe-male rats.

Objective:To observe therapeutic effect of catalpol on Sj?gren's syndrome(SS)model mice and explore further mechanism through vitro experiments.Methods:Eight-week-old NOD mice were given catalpol 100 mg/kg by gavage for 8 weeks.Serum levels of IFN-γ and IL-17 were measured.Pathological of salivary glands were observed.lnc-NONHSAT071210 shRNA trans-fected salivary gland epithelial cell lines were treated with 50 μmol/L catalpol,and expression of lnc-NONHSAT071210 was detected.Cells were intervented by 10 ng/ml IFN-γ,lnc-NONHSAT071210 shRNA and catalpol treatment for 72 h,cell proliferation and expressions of IL-17 and IFN-γ were detected.Results:Compared with control group,expressions of IFN-γ and IL-17 were decreased(P<0.05),pathology of salivary gland showed that infiltration of lymphocytes was reduced and destruction of gland structure was significantly reduced in catalpol group.Compared with IFN-γ intervention group,catalpol treatment significantly increased prolifera-tion of salivary gland epithelial cells,and decreased expressions of IFN-γ and IL-17(P<0.05).After catalpol treatment,expression of lnc-NONHSAT071210 was decreased(P<0.05).Moreover,IFN-γ and IL-17 expressions were decreased by catalpol and lnc-NONH-SAT071210 shRNA co-treatment(P<0.01).Conclusion:Catalpol can inhibit expressions of inflammatory cytokines in serum and infiltration of lymphocyte in salivary gland of SS model mice,and inhibit salivary gland ductal fine epithelial inflammatory response and progression of SS by regulating lnc-NONHSAT071210.

Objective:To evaluate the effect of electroacupuncture on liver regeneration after partial hepatectomy in mice and the role of the Notch signaling pathway.Methods:Thirty-six SPF healthy male C57BL/6 mice, aged 6 weeks, weighing 20-22 g, were divided into 6 groups ( n=6 each) using a random number table method: sham operation group (group S), partial hepatectomy group (group PH), non-acupoint electroacupuncture+ partial hepatectomy group (group NPH), partial hepatectomy+ Fli-06 group (group PH+ F), acupoint electroacupuncture+ partial hepatectomy group (group EPH), and acupoint electroacupuncture+ partial hepatectomy+ Fli-06 group (group EPH+ F). All the mice except for group S underwent partial hepatectomy. Fli-06 4.8 mg/kg was intraperitoneally injected starting from 2 days before surgery, once a day, until the mice were sacrificed in group PH+ F and group EPH+ F, while the equal volume of 0.9% sodium chloride solution was injected in the other groups. In EPH group, electroacupuncture of bilateral " Zusanli" acupoints lasting for 15 min was performed using continuous waves with a frequency of 2 Hz and an intensity of 1 mA once a day starting from the time point immediately after surgery for 3 consecutive days. Mice were anesthetized at day 2 after partial hepatectomy, and blood samples were taken from the eyeball for determination of the serum alanine transaminase (ALT) and aspartate aminotransferase (AST) concentrations (using a fully automated biochemical analyzer) and concentrations of serum epidermal growth factor (EGF) and hepatocyte growth factor (HGF) (by enzyme-linked immunosorbent assay). The mice were subsequently sacrificed and liver tissues were taken for calculation of the liver mass to body mass ratio and for determination of the expression of liver proliferation marker Ki-67 (by immunohistochemical staining), proliferating cell nuclear antigen (PCNA), cyclin D1 (CCND1), Notch Intracellular Domain (NICD), and hypoxia-inducible factor-1alpha (HIF-1α) (using Western blot) and Notch1, jagged canonical Notch ligand 1 (Jagged1) and hairy and enhancer of split 1 (Hes1) mRNA (by real-time polymerase chain reaction). Results:Compared with group S, the serum ALT, AST, EGF and HGF concentrations were significantly increased, and the expression of hepatic Notch1, Jagged1 and Hes1 mRNA and Ki-67, PCNA, CCND1 and NICD was up-regulated in group PH ( P<0.05 or 0.01). Compared with group PH, the liver mass to body mass ratio and serum EGF and HGF concentrations were significantly increased, the serum ALT and AST concentrations were decreased, and the expression of hepatic Notch1, Jagged1, Hes1 mRNA and Ki-67, PCNA, CCND1, NICD and HIF-1α was up-regulated in group EPH, and the liver mass to body mass ratio and the serum HGF concentrations were significantly decreased, the serum ALT and AST concentrations were increased, and the expression of hepatic Jagged1 and Hes1 mRNA and Ki-67, PCNA, CCND1, NICD, and HIF-1α was down-regulated in group PH+ F ( P<0.05 or 0.01). Compared with group EPH, the liver mass to body mass ratio and serum EGF and HGF concentrations were significantly decreased, the serum ALT and AST concentrations were increased, and the expression of hepatic Notch1, Jagged1, Hes1 mRNA and Ki-67, PCNA, CCND1, NICD and HIF-1α was down-regulated in group EPH+ F ( P<0.01). Conclusions:Electroacupuncture at Zusanli acupoint promotes liver regeneration after partial hepatectomy in mice, and the mechanism may be related to the activation of the Notch signaling pathway.

BACKGROUND:Muscle weakness is a common symptom after coronavirus disease 2019(COVID-19)infection and affects the ability to perform daily activities in humans during recovery.Low-frequency pulsed magnetic field stimulation at a strength of 1.5 mT and a frequency of 3 300 Hz can enhance the maximal voluntary contraction and strength endurance of human skeletal muscle by inducing and activating classical transient receptor potential channel 1(TRPC1),which produces a series of pathological support effects on muscle tissue.It has not been studied whether this means will improve muscle weakness in patients recovering from COVID-19. OBJECTIVE:To select the low-frequency pulsed magnetic field for magnetic stimulation of lower limb muscle groups in patients with COVID-19,in order to observe the effect of this stimulation on the improvement of muscle weakness of lower limb muscle groups in patients with COVID-19 during the recovery period. METHODS:Fourteen patients infected with COVID-19(Omicron strain)positive for Innovita COVID-19 Ab Test(Colloidal Gold)and accompanied by muscle weakness were recruited and randomly divided into two groups:a test group receiving magnetic field stimulation and a control group receiving sham treatment,respectively.The total duration of the trial was 3 weeks.The test group was given low-frequency pulsed magnetic stimulation of the lower limbs every 48 hours and the control group was given the same intervention procedure as the test group but with sham stimulation.Patients in both groups were not informed whether the magnetic stimulation apparatus was running or not.Nine sessions were performed in both groups and the changes in the maximum voluntary contraction,explosive leg force and strength endurance of the local muscle groups of the lower limbs were subsequently observed in both groups. RESULTS AND CONCLUSION:Among the eight local muscle groups collected,seven local muscle groups in the test group showed an increase in the maximum voluntary contraction value after 3 weeks of low-frequency pulsed magnetic field stimulation.In the control group,there were only three muscle groups with improvement in the maximum voluntary contraction.The rate of improvement in the anterior and posterior muscle groups of the left leg in the test group was significantly higher than that in the control group.The longitudinal jump height and peak angular velocity of the knee joint in both groups were improved compared with the pre-test measurement,and the elevation rate of jumping height in the test group was higher than that in the control group.Under the fatigue condition,the decline rates of peak angular velocity of the knee joint and jumping height in the test group decreased significantly,while those in the control group did not change significantly.The above data confirmed that the low-frequency pulsed magnetic field stimulation with the intensity of 1.5 mT and frequency of 3 300 Hz could improve the muscle strength of more local muscle groups in the lower limbs of patients with COVID-19 during the recovery period compared with the human self-healing process,and the whole-body coordination ability and functional status based on explosive leg force of the legs could be significantly improved.Therefore,low-frequency pulsed magnetic field stimulation can be used as an effective,non-exercise rehabilitation tool to improve muscle weakness in the lower limbs of patients with COVID-19.

Objective:To investigate the safety and feasibility of the occipital condyle screw and evaluate the safepath parameters for the occipital condyle screw.Methods:Data of 64 patients with upper cervical computed tomographic angiograms from September 2016 to September 2018 were retrospectively collected. Excluded occipito-cervical injury, tumor, and vertebral artery course variation. Mimics software was used to reconstruct the occiput, atlas and vertebral artery. Three candidate entry points were placed for each occipital condyle, the midpoint of posterior of occipital condyle as middle entry point, and the medial and lateral entry points were located 3 mm medial and lateral to the middle entry point. The vertebral artery-occipital bone distance (VOD) of each entry point were measured on sagittal plane, and the minimum feasible value was determined to be 4mm. After that 3.5 mm diameter virtual screw was inserted into each candidate entry point with VOD>4 mm, each screw with maximum and minimum cranial angulation was combined with appropriate medial angulation to get the maximum screw length. Then, the screw placement parameters were measured by 3-Matic, and the safe range of cranial angulation and the success rate of screw placement were calculated.Results:The VOD of medial and middle entry point were 8.07±2.13 mm and 7.70±2.19 mm respectively, and the feasibility rate of screw placement of those entry point were 97.7% and 96.1%, respectively. There were significant differences inVOD and feasibility rate of screw placement between medial and middle entry point. The VOD of lateral entry point was 5.63±1.66 mm, and the feasibility rate was only 78.9%, which was significantly lower than that of medial and middle entry point. The lateral entry point could obtain a larger medial angulation, which was supplemented by a longer screw length. The medial angulation and length of screw gradually decreased with the inward movement of the entry point. There were significant differences in medial angulation and screw length among groups. The safe range of cranial angulation of medial, middle and lateral entry points were 8.17°±2.55°, 12.58°±4.23° and 12.09°±3.83°, respectively, and the difference were statistically significant. Among the screw entry point that could accommodate screw fixation, the maximum screw placement success rate can be obtained by adding 5° cranial angulation to the lateral and middle entry point, which were 98.02% and 98.37%, respectively,while 100% success rate of screw placement could be obtained at the medial entry point at 3° cranial angulation.Conclusion:In the selection of the entry point in the horizontal direction, middle and medial entry points have higher success rate of screw placement and wider safe range of cranial angulation because of less affection of horizontal segment of the vertebral artery. However, the screw length of medial entry point is much shorter than middle and lateral entry point. As a result, the middle entry point may be an optimal entry point for the occipital condyle screw.

Pyrrolizidine alkaloids(PAs)are among the most hepatotoxic natural compounds that are widely distributed throughout the world.Most PAs are metabolically activated to trigger toxicity.Exposure to herbal medicine containing PAs and food supplements contaminated by PAs is considered to be one of the two main causes of hepatic sinusoidal obstruction syndrome(HSOS),which is a rare hepatic vascular disease with a high mortality rate.PAs-induced HSOS cases have been reported worldwide.However,there is no clinically effective therapy for PAs-induced HSOS,which is partially because the toxic mechanism is not fully understood.This review focuses on updating the information on the metabolism and the molecular mechanisms of PAs hepatotoxicity,including oxidative stress,apoptosis,and dysfunction of bile acid metabolism,and their interactions.