Objective:To develop a modified University of Wisconsin preservation solution (UW solution) containing α 2-adrenergic receptor agonists (dexmedetomidine) and noble gases (argon) and investigate its protective effect on the isolated amputated skeletal muscle of rats. Methods:Sixty male SD rats were selected to establish a hindlimb cold preservation/perfusion model and were divided into blank control group, hypothermic storage group, UW solution perfusion group, and modified UW solution perfusion group using a random number table, with 15 rats in each group. Simultaneously, a cold preservation model of rat skeletal muscle myoblasts (L6 cells) was established and the rats were also divided into four groups in the same way. Animal models were prepared in different ways: In the blank control group, the hindlimbs received no special treatment; In the hypothermic storage group, the amputated hindlimbs were stored in a dry centrifuge tube at 4℃ for 18 hours; In the UW solution perfusion group, the amputated hindlimbs were perfused with UW solution and then stored in a centrifuge tube containing UW solution at 4℃ for 18 hours; In the modified UW solution perfusion group, the amputated hindlimbs were perfused with modified UW solution (containing 0.1 nmol/L dexmedetomidine and 50% volume fraction of argon) and then stored in a centrifuge tube containing the modified UW solution at 4℃ for 18 hours. Cell models were treated as follows: In the blank control group, L6 cells were cultured under standard conditions; In the hypothermic storage group and UW solution group, L6 cells were treated with conventional culture medium or UW solution, stored in argon-filled sealed bags at 4℃ for 8 hours, and then rewarmed and cultured for 6 hours; In the modified UW solution group, L6 cells were treated with the modified solution, stored in argon-filled sealed bags at 4℃ for 8 hours, and then rewarmed and cultured for 6 hours. After sample collection, skeletal muscle morphology, tissue edema and ultrastructure features were assessed by HE staining, wet-to-dry weight ratio, and transmission electron microscopy, respectively. Additionally, L6 cell morphology was examined by light microscopy. L6 cell viability was determined by cell counting kit-8 (CCK-8) assay (expressed as absorbance A value). Expression levels of glutathione peroxidase 4 (GPX4) protein in both skeletal muscle tissue and L6 cells were evaluated by immunofluorescence staining and Western blot, respectively.Results:After 18 hours of in vitro preservation of rat isolated amputated limbs, the following results were obtained: (1) HE staining results showed that the muscle fiber morphology of the modified UW solution perfusion group was close to that of the blank control group. Moreover, the area ratio of skeletal muscle cells in the modified UW solution perfusion group was significantly higher than that in the hypothermic storage group and UW solution perfusion group ( P<0.05). (2) The wet-dry weight ratio results showed that there was no statistically significant difference among the modified UW solution perfusion group, the blank control group and UW solution group ( P>0.05), with significantly lower ratios in all three groups than that in the hypothermic storage group ( P<0.05). (3) Transmission electron microscopy results revealed that the modified UW solution perfusion group showed no statistically significant differences in ultrastructural metrics, including myofiber diameter, sarcomere length, mitochondrial short-axis/long-axis ratio, and mitochondrial cristae count, compared with those in the blank control group ( P>0.05), and performed significantly better than both the hypothermic storage group and UW solution perfusion group ( P<0.05). (4) Morphological observation of L6 cells showed that the cellular morphology was regular in the modified UW solution perfusion group, close to that in the blank control group, while it was severely damaged in the hypothermic storage group. Moreover, the cells were reduced in number and partially damaged in the UW solution group. The sequence of cell viability expressed as absorbance A value was blank control group >modified UW solution perfusion group > UW solution perfusion group > hypothermic storage group, with statistically significant differences among the four groups ( P<0.05). (5) Immunofluorescence staining showed that there was no statistically significant difference in fluorescence intensity of GPX4 protein expression between the modified UW solution perfusion group and blank control group ( P>0.05), while the fluorescence intensity was higher in the modified UW solution perfusion group than that in the hypothermic storage group and UW solution perfusion group ( P<0.05). Western blot analysis showed that the relative expression level of GPX4 in the modified UW solution group was significantly lower than that in the blank control group ( P<0.05), but higher than that in the hypothermic storage group and UW solution perfusion group ( P<0.05). Conclusion:The modified UW solution can stabilize the expression level of GPX4 protein, thereby inhibiting ferroptosis and alleviating cold preservation injury in both rat amputated isolated limb skeletal muscle tissue and L6 cells.

Objective:To develop a modified University of Wisconsin preservation solution (UW solution) containing α 2-adrenergic receptor agonists (dexmedetomidine) and noble gases (argon) and investigate its protective effect on the isolated amputated skeletal muscle of rats. Methods:Sixty male SD rats were selected to establish a hindlimb cold preservation/perfusion model and were divided into blank control group, hypothermic storage group, UW solution perfusion group, and modified UW solution perfusion group using a random number table, with 15 rats in each group. Simultaneously, a cold preservation model of rat skeletal muscle myoblasts (L6 cells) was established and the rats were also divided into four groups in the same way. Animal models were prepared in different ways: In the blank control group, the hindlimbs received no special treatment; In the hypothermic storage group, the amputated hindlimbs were stored in a dry centrifuge tube at 4℃ for 18 hours; In the UW solution perfusion group, the amputated hindlimbs were perfused with UW solution and then stored in a centrifuge tube containing UW solution at 4℃ for 18 hours; In the modified UW solution perfusion group, the amputated hindlimbs were perfused with modified UW solution (containing 0.1 nmol/L dexmedetomidine and 50% volume fraction of argon) and then stored in a centrifuge tube containing the modified UW solution at 4℃ for 18 hours. Cell models were treated as follows: In the blank control group, L6 cells were cultured under standard conditions; In the hypothermic storage group and UW solution group, L6 cells were treated with conventional culture medium or UW solution, stored in argon-filled sealed bags at 4℃ for 8 hours, and then rewarmed and cultured for 6 hours; In the modified UW solution group, L6 cells were treated with the modified solution, stored in argon-filled sealed bags at 4℃ for 8 hours, and then rewarmed and cultured for 6 hours. After sample collection, skeletal muscle morphology, tissue edema and ultrastructure features were assessed by HE staining, wet-to-dry weight ratio, and transmission electron microscopy, respectively. Additionally, L6 cell morphology was examined by light microscopy. L6 cell viability was determined by cell counting kit-8 (CCK-8) assay (expressed as absorbance A value). Expression levels of glutathione peroxidase 4 (GPX4) protein in both skeletal muscle tissue and L6 cells were evaluated by immunofluorescence staining and Western blot, respectively.Results:After 18 hours of in vitro preservation of rat isolated amputated limbs, the following results were obtained: (1) HE staining results showed that the muscle fiber morphology of the modified UW solution perfusion group was close to that of the blank control group. Moreover, the area ratio of skeletal muscle cells in the modified UW solution perfusion group was significantly higher than that in the hypothermic storage group and UW solution perfusion group ( P<0.05). (2) The wet-dry weight ratio results showed that there was no statistically significant difference among the modified UW solution perfusion group, the blank control group and UW solution group ( P>0.05), with significantly lower ratios in all three groups than that in the hypothermic storage group ( P<0.05). (3) Transmission electron microscopy results revealed that the modified UW solution perfusion group showed no statistically significant differences in ultrastructural metrics, including myofiber diameter, sarcomere length, mitochondrial short-axis/long-axis ratio, and mitochondrial cristae count, compared with those in the blank control group ( P>0.05), and performed significantly better than both the hypothermic storage group and UW solution perfusion group ( P<0.05). (4) Morphological observation of L6 cells showed that the cellular morphology was regular in the modified UW solution perfusion group, close to that in the blank control group, while it was severely damaged in the hypothermic storage group. Moreover, the cells were reduced in number and partially damaged in the UW solution group. The sequence of cell viability expressed as absorbance A value was blank control group >modified UW solution perfusion group > UW solution perfusion group > hypothermic storage group, with statistically significant differences among the four groups ( P<0.05). (5) Immunofluorescence staining showed that there was no statistically significant difference in fluorescence intensity of GPX4 protein expression between the modified UW solution perfusion group and blank control group ( P>0.05), while the fluorescence intensity was higher in the modified UW solution perfusion group than that in the hypothermic storage group and UW solution perfusion group ( P<0.05). Western blot analysis showed that the relative expression level of GPX4 in the modified UW solution group was significantly lower than that in the blank control group ( P<0.05), but higher than that in the hypothermic storage group and UW solution perfusion group ( P<0.05). Conclusion:The modified UW solution can stabilize the expression level of GPX4 protein, thereby inhibiting ferroptosis and alleviating cold preservation injury in both rat amputated isolated limb skeletal muscle tissue and L6 cells.

Objective To explore the pharmacokinetic characteristics of sufentanil in individuals with normal body mass index(BMI),overweight BMI,and different CYP3A4/5 enzyme genotypes.Methods The patients receiving laparoscopic surgery under general anesthesia in the First Affiliated Hospital of Army Medical University from November 2020 to September 2021 were prospectively recruited in this study.Before the operation,the oral swabs were collected from all the patients for genotyping using the human CYP3A4/5 gene kit.Based on the potential impact of combination of their polymorphisms on sufentanil metabolism and the proportion of different genotype combinations of CYP3A4/5 enzymes,the patients were divided into groups I(3A4 homozygous mutation or 3A4 heterozygous mutation+3A5 homozygous mutation),II(3A4 heterozygous mutation+3A5 heterozygous mutation),and III(3A4 wild type or 3A4 heterozygous mutation+3A5 wild type).According to their BMI,they were also assigned into a normal body weight group(18.5～24.0 kg/m2)and an overweight group(24～<28 kg/m2),and the differences in drug metabolism parameters were statistically analyze between the 2 groups.After routine general anesthesia induction(sufentanil 0.5 μg/kg),venous blood samples were collected to detect the changes in its concentration using high performance liquid chromatography-mass spectrometry(HPLC-MS).The pharmacokinetic data of sufentanil were calculated between the normal BMI group and overweight group in all participants and between the 2 body weight groups among those with different genotype combinations.Results Among the 90 participants completing the blood drug concentration test,8 patients had their blood samples contaminated(including 1 case with an anesthesia duration of<2 h),and 3 were excluded due to low weight or overweight.Eventually,79 participants were included in the pharmacokinetic analysis on the normal body weight group and the overweight group.Compared with the normal body weight group,the central compartment volume of distribution in the overweight group was significantly reduced(P<0.05),while no obvious differences were observed between the 2 groups in terms of peripheral compartment volume of distribution,total clearance rate,peripheral compartment clearance rate,distribution half-life,clearance half-life,and area under the blood concentration-time curve.In group Ⅰ(n=26),the overweight patients(n=13)had significantly reduced central compartment volume of distribution,peripheral compartment volume of distribution,and peripheral compartment clearance rate when compared with the normal body weight patients(n=13)(P<0.05),while no differences were observed in other pharmacokinetic parameters.In groups Ⅱ(n=25)and Ⅲ(n=28),the overweight patients and normal body weight patients had no statistical differences in all pharmacokinetic parameters.Conclusion Among the patients with the same genotype combination of CYP3A4/5 mutations,there was no difference in the metabolism of sufentanil between the overweight and normal weight patients.Additionally,in the population of 3A4 homozygous mutation or 3A4 heterozygous mutation+3A5 homozygous mutation,the overweight patients have smaller peripheral distribution range of sufentanil,and weakened metabolic process.

ObjectiveTo quantitatively investigate the changes in the total volume and contour density of hepatic oval cells （HOC） in hepatic lobules of rats with carbon tetrachloride （CCl₄）-induced hepatic fibrosis. MethodsA total of 11 healthy male Sprague-Dawley rats were randomly divided into control group with 5 rats and hepatic fibrosis group with 6 rats， and CCl₄ and olive oil suspension were injected subcutaneously twice a week， 3 mL/kg each time. After five weeks of hepatic fibrosis modeling， five liver tissue blocks with a size of about 1 mm³ were randomly selected from the liver of each rat to prepare one Epon812 epoxy resin-embedded ultrathin section， and the stereological method and transmission electron microscopy were used for the quantitative analysis of the total volume and contour density of HOC in the hepatic lobules of rats. In addition， four liver tissue blocks with a thickness of 2 mm were randomly selected from the remaining liver of each rat to prepare two paraffin-embedded Masson staining sections， and the degree of liver fibrosis in each rat was qualitatively evaluated according to the Metavir staging criteria for liver fibrosis. The independent-samples t test was used for comparison of continuous data between groups. ResultsThe quantitative stereological analysis showed that the total volume of HOC in hepatic lobules was 15.40±7.63 mm³ in the control group and 146.80±114.00 mm³ in the liver fibrosis group， and compared with the control group， the total volume of HOC in hepatic lobules of rats in the liver fibrosis group was significantly increased by 8.53 times （t=-2.551， P=0.031）； the contour density of HOC in hepatic lobules was 56.20±40.40 in the control group and 566.50±317.00 in the liver fibrosis group， and compared with the control group， the contour density of HOC in hepatic lobules of rats in the liver fibrosis group was significantly increased by 9.08 times （t=-3.539， P=0.006）. Qualitative observation showed that liver fibrosis stage of rats reached stage Ⅱ-Ⅲ according to the Metavir scoring criteria， and massive proliferation of HOC was observed around the proliferation site of hepatic stellate cells in the perisinusoidal space of rats. ConclusionCCl₄ induces significant proliferation of HOC in hepatic lobules of rats with liver fibrosis.

Objective To investigate the effect of minocycline(Mino)on the polarization of types M1/M2 microglia(pro-and anti-inflammatory type)in the spinal dorsal horn of rats with neuropathic pain(NP)induced by spinal nerve ligation(SNL)and its underlying mechanism.Methods A total of 36 adult male SD rats were randomly stratified into Sham-operation(Sham)group,SNL group and Mino+SNL group by stratified random sampling based on body weight.Mechanical pain threshold and cold nociceptive thresholds of rat hind paw were measured in 1 d before and 14 d after modelling.Spinal cord tissue at the lumbar 5(L5)segment was taken at 14 d after modelling,and the total number of microglia as well as the numbers of M1 and M2 microglia in the spinal dorsal horn were measured with immunohistochemistry and stereology.With aid of bioinformatics techniques,the core target in the spinal cord,Cst7,was selected.Then,the protein levels of microglia marker Iba-1,M1 microglia marker iNOS,M2 microglia marker CD206,Cst7 encoded protein cystatin F(CF)and pathway CatS/CX3CL1/CX3CR1 were detected with Western blotting.The expression levels of TNF-α,IL-6 and IL-10 in the spinal cord tissues were measured with ELISA.Results The mechanical pain and cold nociceptive thresholds were both significantly higher in the M+SNL group than the SNL group at 7～14 d after modelling(P＜0.01).The total number of microglia and the numbers of M1/M2 microglia in the spinal dorsal horn as well as the expression levels of CatS,CX3CL1,CX3CR1,TNF-α,IL-6,and IL-10 in the spinal cord tissues were obviously increased,and the expression level of CF was notably decreased in the SNL model group than the Sham group(P＜0.01).While,Mino treatment remarkably reversed above phenomena,with decreased total number of microglia and number of M1 microglia as well as expression levels of CatS,CX3CL1,CX3CR1,TNF-α and IL-6,and increased number of M2 microglia as well as CF and IL-10 levels when compared with the SNL group(P＜0.05).Conclusion Mino alleviates SNL induced neuropathic pain,probably through up-regulating CF in the microglia,and thus inhibiting the CatS/CX3CL1/CX3CR1 signaling pathway,promoting the conversion of microglia from type M1 to M2 to balance the imbalance in the M1/M2 polarization,and thus reducing neuroinflammation.

Oral microbial community, as an important part of human microbial community, is closely related to oral and general health. Oral microbiological research has become the forefront of international microbiological research. Standardized and unified nomenclature for oral microorganisms in Chinese is of great significance to support the development of oral medicine research. Standardized translation of microbial names is the basis for writing canonical and authoritative professional textbooks and reference books, which helps students to accurately acquire the characteristics and classifications of oral microbes. Unified translation of oral microorganisms is also conducive to academic communication and cooperation, and plays an important role in oral health education and science popularization, which enables oral microbiology knowledge to be accurately disseminated to the public. Therefore, in order to standardize the words in scientific research, funding application, publications, academic exchanges and science popularization within the field of oral medicine, we have fully discussed and revised the Chinese names of oral microorganisms in 2017 edition and ones of newly discovered oral microbes, finally reaching a consensus to form the 2023 edition of Chinese names of oral microorganisms.

The dental operative microscope has been widely employed in the field of dentistry, particularly in endodontics and operative dentistry, resulting in significant advancements in the effectiveness of root canal therapy, endodontic surgery, and dental restoration. However, the improper use of this microscope continues to be common in clinical settings, primarily due to operators' insufficient understanding and proficiency in both the features and established operating procedures of this equipment. In October 2019, Professor Jingping Liang, Vice Chairman of the Society of Cariology and Endodontology, Chinese Stomatological Association, organized a consensus meeting with Chinese experts in endodontics and operative dentistry. The objective of this meeting was to establish a standard operation procedure for the dental operative microscope. Subsequently, a consensus was reached and officially issued. Over the span of about four years, the content of this consensus has been further developed and improved through practical experience.
Humans ; Dentistry, Operative ; Consensus ; Endodontics ; Root Canal Therapy ; Dental Care

Objective:To investigate the MRI features of perirenal space involvement in patients with acute pancreatitis (AP) and its correlation with disease severity.Methods:A total of 128 AP patients admitted to Bishan District People′s Hospital of Chongqing from June 2018 to June 2020 were selected as study subjects. All patients were diagnosed by ultrasound guided percutaneous biopsyand the pathological diagnosis results were taken as the gold standard. The accuracy, sensitivity and specificity of MRI diagnosis were calculated to analyze the correlation between MRI features of perirenal space involvement and MRI severity index (MRSI).Results:Among the 128 patients, 96 patients with perirenal space involvement in AP confirmed by ultrasound guided percutaneous biopsyand the pathological diagnosis results, accounted for 75.00%. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value diagnosed by MRI were 95.83%, 93.75%, 95.31%, 97.87% and 88.24% respectively. The involvement rate of perirenal space in AP was 75.00%(96/128), and that in mild, moderate and severe AP was 52.38%(22/42), 93.62%(44/47) and 7/7, respectively. Forty-two mild patients presented abnormal signals in the pancreas, or focal and diffuse pancreatic enlargement, thickening, and abnormal streak signalabnormalities in perirenal space, perirenal MRI showed grade 1 and 2. Forty-seven patients with moderate disease showed patchy signal abnormalities in the perirenal space, and perirenal MRI showed grade 3. Seven severe patients found perirenal interstitial effusion which was patchy. There was a good correlation between MRI features grade of perirenal space involvement and MRSI ( r = 0.721, P<0.001). The consistent rate of MRI features score of the right perirenal space was 91.14%, the consistent rate of MRI features score of the left perirenal space was 95.38%, and the consistent rate of MRSI observation on both was 90.21%. Conclusions:MRI can effectively and accurately diagnose perirenal space involvement in AP patients, MRI features and involvement rate can accurately reflect the severity of AP, which has a positive effect on clinical diagnosis and treatment of patients with perirenal space involvement in AP.

Objective To investigate the radiation dose to operators in the process of ²⁴¹Am-Be neutron source logging, and discuss neutron source management and protective measures for operators in well logging. Methods Through on-site observation and measurement of ²⁴¹Am-Be neutron source logging in a company, we obtained the surface γ dose rate and neutron dose rate of the neutron source, as well as the operating time and distance of various processes including source taking, transfer, and loading, calculated the radiation dose to operators in various processes, and analyzed the source and proportion of the personal effective dose to operators. Results The effective doses of neutron irradiation and γ irradiation were 94.17 μSv and 2.72 μSv, respectively, for the combined processes of source tank inspection, transfer, and detection; 36.66 μSv and 24.08 μSv, respectively, for source loading and unloading; and 130.83 μSv and 26.80 μSv, respectively, for the whole neutron source logging process. The total annual effective dose of neutron source logging was 15.78 mSv, as estimated by logging 100 times per year. Conclusion In the process of ²⁴¹Am-Be neutron source logging in the company, the effective dose to operators mainly arises from neutron irradiation. Therefore, it is necessary to strengthen neutron source management and take effective protective measures against neutron radiation.

Objective:To investigate the current status of satisfaction with training program and loyalty to the university among professional postgraduate students majoring in clinical medicine, as well as the association between satisfaction with training program and loyalty to the university.Methods:The 2017 National Medical Student Satisfaction Survey Database was used. A total of 1 944 professional postgraduate students in the second or third year, as well as those with delayed graduation, from 59 postgraduate training colleges and universities who participated in clinical internship were selected. SPSS 20.0 software was used for analysis; descriptive analysis was used to describe satisfaction with training program and loyalty to the university; factor analysis was adopted to calculate comprehensive satisfaction score to reduce the number of variables; logistic regression analysis was applied to investigate the association of general information and satisfaction with training program with loyalty to the university.Results:The professional postgraduate students majoring in clinical medicine had a degree of 60.44% of loyalty to the university. Satisfaction with training program reflected low satisfaction at each link of the training program. For every 1-point increase in the comprehensive satisfaction scores of the four links of courses, research training, college support, and practice, the loyalty to the university was increased to 2.11, 1.83, 1.77, and 1.75 times as the original, respectively, of the baseline scores.Conclusion:There is still room for further improvement in the satisfaction with training program and the loyalty to the university among professional postgraduate students majoring in clinical medicine, and the satisfaction with training program is closely associated with the loyalty to the university. Colleges and universities need to take measures for courses, practice, research training, and college support, so as to improve satisfaction and thus enhance loyalty to the university.