Aim To investigate the regulatory effect of Cortaetin on pathological myocardial hypertrophy induced by isoprenaline (ISO) and the underlying mechanism. Methods ISO was used to stimulate neonatal rat cardiomyocytes for 24 h, and myocardial hypertrophy model was established at the cellular level. C57BL/6 mice were injected subcutaneously with ISO for one week to establish myocardial hypertrophy model at animal level. RT-qPCR was used to detect the changes of mRNA and Western blot was used to detect the changes of relative protein content. Immunofluorescence was used to measure the subcellular location of Cortaetin and the change of its expression. The overex-pression of Cortaetin by adenovirus infection and the knockdown of Cortaetin by transfection of small interfering RNA were studied. Results On the cellular and animal levels, ISO-induced myocardial hypertrophy models were successfully established, and it was observed that ISO caused the decrease of Cortaetin and N-cadherin protein levels. Overexpression of Cortaetin could reverse the decrease of N-cadherin protein level and myocardial hypertrophy caused by ISO. Knockdown of Cortaetin showed the opposite effect. Conclusion Cortaetin, in combination with N-cadherin, may play a role in combating myocardial hypertrophy by enhancing the connections between cardiomyocytes.

Objective To study the mechanism of the amelioration of renal injury in immunoglobulin A nephropathy(IgAN)rats by multi-glycosides of Tripterygium wilfordii(GTW)based on the sphingosine kinase 1(Sphk1)/sphingosine 1-phosphate receptor 2(S1PR2)signalling pathway.Methods An IgAN rat model was established by means of bovine serum albumin gavage+castor oil and carbon tetrachloride subcutaneous injection+lipopolysaccharide tail vein injection.The rats were randomly divided into the model,control and experimental groups,with 9 rats in each group,and 10 normal rats were taken as the blank group.In the control group,6.25 mg·kg-1·d-1 prednisone was given by gavage;in the experimental group,9.375 mg·kg-1·d-1GTW was given by gavage;and in the blank and model groups,0.5 mL·100 g-1·d-1 0.9％NaCl was given by gavage,and the drugs were administered to the rats once a day in each group.At the end of the 15th week,urine samples were collected and blood albumin(ALB),blood urea nitrogen(BUN),24 hour-urine protein quantification(24 h-UTP),and urine erythrocyte counts were determined in each group,and the expression levels of Sphk1/S1PR2 proteins in each group were detected by Western blotting.Results The renal pathological changes in the control and experimental groups were significantly reduced compared with those in the model group by hematoxylin-eosin staining and immunofluorescence.The levels of ALB in the blank,model,control and experimental groups were(32.49±2.23),(22.98±0.51),(26.01±1.33)and(26.53±1.92)g·L-1;the levels of BUN were(6.11±1.71),(13.75±2.96),(6.71±1.35)and(4.77±0.99)mmol·L-1;the levels of 24 h-UTP were(5.72±1.96),(9.12±2.15),(5.78±2.05)and(4.75±1.50)mg·24 h-1;the urine erythrocyte counts were(9.73±2.40),(14.62±2.60),(9.90±1.59)and(9.46±2.94)cell·μL-1;the relative expression levels of Sphk1 protein were 0.85±0.02,1.47±0.02,1.06±0.02 and 1.09±0.02;the relative expression levels of S1PR2 protein were 0.27±0.02,0.88±0.01,0.43±0.02,and 0.42±0.02,respectively.The above indexes in the model group were statistically significant when compared with those of the control group and the experimental group(all P＜0.01).Conclusion GTW may reduce the proliferation of mesangial cells by inhibiting the Sphk1/S1PR2 signalling pathway,thus attenuating kidney injury in IgAN rats.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

AIM To study the amino acids and proteins in 16 batches of commercial fish swim-bladders with different origins.METHODS A high performance liquid chromatography method based on pre-column derivatization using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate(AQC)was developed for the determination of contents and components of 17 amino acids in fish swim-bladders.Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)was performed to analyze the molecular weight distribution of proteins from different fish swim-bladders,and proteins in fish swim-bladders were identified by proteomics method.RESULTS The result showed that the determination of 17 amino acids had a good linear relationship(R2≥0.998 0).The average recovery rate was 85.62%-109.60%and the relative standard deviations of precision,stability and repeatability were less than 3.5%.The total content of the 17 amino acids in 16 batches of fish swim-bladders ranged from 468.31 mg/g to 620.05 mg/g.A total of 688 proteins including 11 collagens were identified from 16 batches of fish swim-bladder samples and a plenty of low-abundance proteins at 52-95 kDa were also detected in fish swim-bladders by SDS-PAGE.CONCLUSION This study provides a good reference for the quality evaluation and further utilization of fish swim-bladders.

Objective:To investigate the prevalence of adult skeletal fluorosis caused by drinking tea-type endemic fluorosis in Yushu Tibetan Autonomous Prefecture (hereinafter referred to as Yushu Prefecture), Qinghai Province, and provide scientific basis for prevention and control of the disease.Methods:In August 2021, one village was selected as a survey site in six counties (cities) in Yushu Prefecture, including Nangqian, Chindu, Yushu, Zadoi, Qumarlêb, and Zhiduo. Drinking water samples and 10 brick tea samples were collected from each village to determine the fluoride content in water and brick tea; at least 100 permanent residents aged ≥ 25, who had a habit of drinking brick tea and had lived in the local area for more than 5 years, were selected for X-ray imaging to examine the prevalence of adult skeletal fluorosis.Results:A total of 75 samples of residential drinking water were collected, with a fluoride content of (0.21 ± 0.05) mg/L, ranging from 0.11 to 0.34 mg/L; 60 samples of brick tea, with a fluoride content of (626.70 ± 157.27) mg/kg, ranging from 324.00 to 2 102.00 mg/kg. A total of 1 136 adults were examined, and 318 cases of skeletal fluorosis were diagnosed, with a detection rate of 27.99%. Among them, the detection rates of mild, moderate, and severe skeletal fluorosis were 20.95% (238/1 136), 6.07% (69/1 136), and 0.97% (11/1 136), respectively, with mild symptoms being the main. The detection rates of skeletal fluorosis in males and females were 29.09% (121/416) and 27.36% (197/720), respectively, with no statistically significant difference between the gender (χ 2 = 0.39, P = 0.533). Comparison of the skeletal fluorosis in different gender, the differences were statistically significant (χ 2 = 22.31, P < 0.001). The detection rates of skeletal fluorosis in the age groups of 25 - 35, 36 - 45, 46 - 55, 56 - 65, 66 - 75, and ≥76 years old were 6.86% (7/102), 22.37% (51/228), 24.02% (92/383), 37.44% (73/195), 43.48% (70/161), and 37.31% (25/67), respectively. The differences between the groups were statistically significant (χ 2 = 59.84, P < 0.001). Moreover, there was a statistically significant difference in the composition of skeletal fluorosis among different age groups ( H = 37.66, P < 0.001). The Spearman correlation analysis results showed that the severity of adult skeletal fluorosis was positively correlated with age ( r = 0.34, P < 0.001). Conclusions:There is a certain degree of prevalence of adult skeletal fluorosis in Yushu Prefecture. And as age increases, the condition of skeletal fluorosis becomes more severe.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective:To compare the therapeutic effects of 0.05% cyclosporine and 0.1% fluorometholone eye drops in patients with moderate and severe dry eye.Methods:A randomized controlled study was conducted.Fifty-two patients (52 eyes) with moderate to severe dry eye in Tianjin Medical University Eye Hospital from August 2021 to December 2022 were enrolled and randomly divided into 0.05% cyclosporine group and 0.1% fluorometholone group by random number table method, with 26 cases (26 eyes) in each group.Patients received 0.05% cyclosporine eye drops (2 times/day) and 0.1% fluorometholone eye drops (2 times/day) combined with calf blood deproteinized extract eye drops (4 times/day) according to the grouping.Before and 1, 3 and 6 months after treatment, clinical symptoms and signs were observed and Ocular Surface Disease Index (OSDI) score, corneal fluorescein staining (CFS) score, Schirmer Ⅰ test (SⅠT), non-invasive first tear film break-up time (NIBUTf), and conjunctival goblet cell (CGC) density were recorded.Before treatment and after 6 months of treatment, changes in corneal nerves and dendritic cells (DC) were observed by in vivo confocal microscopy (IVCM).This study adhered to the Declaration of Helsinki and was approved by the Medical Ethics Committee of Eye Hospital of Tianjin Medical University (No.2021KY-17).Written informed consent was obtained from each subject. Results:Compared with the 0.1% fluorometholone group, CFS score decreased after 1 month of treatment, but SⅠT, NIBUTf and CFS score increased after 3 months of treatment, and OSDI score, SⅠT and CFS score decreased after 6 months of treatment in the 0.05% cyclosporine group, showing statistically significant differences (all at P<0.05).Compared with baseline, in the 0.05% cyclosporine group, NIBUTf increased and CFS score decreased after 1 month of treatment, OSDI score and CFS score decreased, SⅠT and NIBUTf increased after 3 and 6 months of treatment, showing statistically significant differences (all at P<0.05).In the 0.1% fluorometholone group, CFS score decreased after 3 months of treatment, OSDI score and CFS score decreased, SⅠT increased after 6 months of treatment compared to baseline, showing statistically significant differences (all at P<0.05).OSDI score and CFS score decreased, SⅠT increased after 6 months of treatment compared to 3 months of treatment in the 0.05% cyclosporine group, and the differences were statistically significant (all at P<0.05).Baseline and CGC densities after 1, 3 and 6 months of treatment were (147.66±17.29), (195.44±15.46), (210.36±19.15) and (282.09±22.63)cells/mm 2 in the 0.05% cyclosporine group and (138.09±17.29), (95.67±15.46), (117.77±19.15) and (109.13±22.63)cells/mm 2 in the 0.1% fluorometholone group, respectively, with a statistically significant overall difference ( Fgroup=11.724, P<0.001; Ftime=4.837, P=0.005).Compared with the 0.1% fluorometholone group, CGC density in the 0.05% cyclosporine group increased after 1, 3 and 6 months of treatment, with statistically significant differences (all at P<0.05).Compared with baseline, the CGC density increased in the 0.05% cyclosporine group after 1, 3 and 6 months of treatment, and the differences were statistically significant (all at P<0.05).Compared with the 0.1% fluorometholone group, the corneal nerve fiber density in the 0.05% cyclosporine group increased after 6 months of treatment, and corneal DC density, area and dendrite number decreased, showing statistically significant differences (all at P<0.05). Conclusions:Cyclosporine 0.05% eye drops combined with calf blood deproteinized extract eye drops can improve symptoms and signs in patients with moderate to severe dry eye, and the long-term effect is better than that of 0.1% fluorometholone plus calf blood deproteinized extract eye drops.

The basic structure and principle of the reverse osmosis water treatment system were described briefly.Three common faults of the system were explored in terms of cause and solution.References were provided for medical engineers to treat similar faults.[Chinese Medical Equipment Journal,2024,45(5):118-120]

Objective To design a punching and positioning device for training Da Vinci surgical robots to improve the efficiency and accuracy of operation training.Methods The punching and positioning device mainly consisted of an abdominal girth,a connecting plate,a punching plate,a positioning disk and a punching cartridge.The abdominal girth had a long-strip shape and was made of stretch nylon elastic band;the connecting plate had a rectangular shape with its length direction perpendicular to the abdominal girth;the punching plate also had a rectangular shape and was made of hard silicone;the positioning plate was made of hard silicone and privided with a plated through hole;the punching cartridge were equipped with anti-fog components composed of heating wires and support strips,which had scale bars inside.Ten physicians were randomly divided into a control group and an experimental group,with 5 ones in each group.The two groups carried out positioning and punching respectively,with the traditional method for the control group and the device designed for the experimental group,which were compared in terms of the time consumption,ratio for lens fogging and number of collisions with the robotic arm.Results The experimental group had the time consumption and ratio for lens fogging lower significantly when compared with the control group(P＜0.05),while had no obvious difference in number of collisions with the robotic arm(P＞0.05),and the requirements of the training specifications were met.Conclusion The punching and positioning device has high efficiency and accuracy,and thus is worthy promoting for the operation training of surgical robots.[Chinese Medical Equipment Journal,2024,45(7):35-39]

Objective To explore the postmortem diffusion rule of Aconitum alkaloids and their metabo-lites in poisoned rabbits,and to provide a reference for identifying the antemortem poisoning or post-mortem poisoning of Aconitum alkaloids.Methods Twenty-four rabbits were sacrificed by tracheal clamps.After 1 hour,the rabbits were administered with aconitine LD50 in decocting aconite root powder by intragastric administration.Then,they were placed supine and stored at 25℃.The biological samples from 3 randomly selected rabbits were collected including heart blood,peripheral blood,urine,heart,liver,spleen,lung and kidney tissues at 0 h,4 h,8 h,12 h,24 h,48 h,72 h and 96 h after intragastric administration,respectively.Aconitum alkaloids and their metabolites in the biological samples were ana-lyzed by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).Results At 4 h after intragastric administration,Aconitum alkaloids and their metabolites could be detected in heart blood,peripheral blood and major organs,and the contents of them changed dynamically with the preservation time.The contents of Aconitum alkaloids and their metabolites were higher in the spleen,liver and lung,especially in the spleen which was closer to the stomach.The average mass fraction of benzoylmesaconine metabolized in rabbit spleen was the highest at 48 h after intragastric administration.In contrast,the contents of Aconitum alkaloids and their metabolites in kidney were all lower.Aconi-tum alkaloids and their metabolites were not detected in urine.Conclusion Aconitum alkaloids and their metabolites have postmortem diffusion in poisoned rabbits,diffusing from high-content organs(stomach)to other major organs and tissues as well as the heart blood.The main mechanism is the dispersion along the concentration gradient,while urine is not affected by postmortem diffusion,which can be used as the basis for the identification of antemortem and postmortem Aconitum alkaloids poisoning.