OBJECTIVE To investigate the effects and potential mechanism of Qiangxin decoction on mitochondrion of rats with chronic heart failure （CHF）. METHODS The CHF model was established by ligating the left anterior descending branch of the coronary artery. Modeled rats were divided into model group， Qiangxin decoction low-dose and high-dose groups （12.25， 24.50 g/kg， calculated by crude drug）， and chemical medicine group （Sacubitril valsartan sodium tablets， 10.42 mg/kg）， with 10 rats in each group； control group was set up without treatment. Each group of rats was orally administered with the corresponding medication or normal saline twice a day for 28 consecutive days. After the last medication， the contents of N-terminal pro-brain natriuretic peptide （NT-proBNP） and adenosine triphosphate （ATP） in serum and phosphatidic acid （PA） and cardiolipin （CL） in myocardial tissue were all detected； the pathological damage and collagen fibrosis of rat myocardial tissue were observed； the apoptosis of myocardial cells was determined； the ultrastructure of myocardial tissue was observed； the protein expressions of mitofusin 1 （Mfn1）， Mfn2， optic atrophy protein 1 （OPA1） and dynamin-related protein 1 （Drp1） were all detected in myocardial tissue. RESULTS Compared with control group，the serum content of NT-proBNP， apoptotic rate of myocardial cells， and relative expressions of S-OPA1 and Drp1 proteins were all increased significantly； serum content of ATP，contents of PA and CL， and relative expressions of Mfn1， Mfn2 and L-OPA1 proteins were all significantly reduced （P＜0.05）. There were abnormal membrane tissue structure in various layers of myocardial tissue， degeneration and necrosis of myocardial cells， and severe fibrosis； the mitochondria were swollen， with reduced or absent cristae， and uneven matrix density. After intervention with Qiangxin decoction， the levels of the aforementioned quantitative indicators in serum and myocardial tissue of rats （excluding CL content in the Qiangxin decoction low- dose group） were significantly reversed （P＜0.05）； the pathological damage of myocardial tissue had significantly improved， fibrosis had significantly reduced， mitochondrial morphology tended to be normal， cristae had increased， and matrix density was uniform. CONCLUSIONS Qiangxin decoction can regulate myocardial mitochondrial function and structural integrity of CHF rats， thereby improving myocardial energy metabolism and antagonizing myocardial fibrosis， the mechanism of which may be associated with activating PA/Mfn/CL signaling pathway.

OBJECTIVE To investigate the effects and potential mechanism of Qiangxin decoction on mitochondrion of rats with chronic heart failure （CHF）. METHODS The CHF model was established by ligating the left anterior descending branch of the coronary artery. Modeled rats were divided into model group， Qiangxin decoction low-dose and high-dose groups （12.25， 24.50 g/kg， calculated by crude drug）， and chemical medicine group （Sacubitril valsartan sodium tablets， 10.42 mg/kg）， with 10 rats in each group； control group was set up without treatment. Each group of rats was orally administered with the corresponding medication or normal saline twice a day for 28 consecutive days. After the last medication， the contents of N-terminal pro-brain natriuretic peptide （NT-proBNP） and adenosine triphosphate （ATP） in serum and phosphatidic acid （PA） and cardiolipin （CL） in myocardial tissue were all detected； the pathological damage and collagen fibrosis of rat myocardial tissue were observed； the apoptosis of myocardial cells was determined； the ultrastructure of myocardial tissue was observed； the protein expressions of mitofusin 1 （Mfn1）， Mfn2， optic atrophy protein 1 （OPA1） and dynamin-related protein 1 （Drp1） were all detected in myocardial tissue. RESULTS Compared with control group，the serum content of NT-proBNP， apoptotic rate of myocardial cells， and relative expressions of S-OPA1 and Drp1 proteins were all increased significantly； serum content of ATP，contents of PA and CL， and relative expressions of Mfn1， Mfn2 and L-OPA1 proteins were all significantly reduced （P＜0.05）. There were abnormal membrane tissue structure in various layers of myocardial tissue， degeneration and necrosis of myocardial cells， and severe fibrosis； the mitochondria were swollen， with reduced or absent cristae， and uneven matrix density. After intervention with Qiangxin decoction， the levels of the aforementioned quantitative indicators in serum and myocardial tissue of rats （excluding CL content in the Qiangxin decoction low- dose group） were significantly reversed （P＜0.05）； the pathological damage of myocardial tissue had significantly improved， fibrosis had significantly reduced， mitochondrial morphology tended to be normal， cristae had increased， and matrix density was uniform. CONCLUSIONS Qiangxin decoction can regulate myocardial mitochondrial function and structural integrity of CHF rats， thereby improving myocardial energy metabolism and antagonizing myocardial fibrosis， the mechanism of which may be associated with activating PA/Mfn/CL signaling pathway.

Objective To investigate the feasibility of establishing an animal model of rectovaginal fistula in rabbits by magnetic compression technique.Methods A magnetic device suitable for preparing rabbit rectovaginal fistula model was self-designed.Eight New Zealand female rabbits were used as experimental subjects.They were placed in a supine position after auricular intravenous anesthesia,and the magnets were placed on both sides of the rectovaginal septum through the vagina and anus,respectively,and the magnets were made to attract together.The operation time was recorded,the general state of the experimental rabbits was observed after operation,and the time of magnet discharge was recorded.The experimental rabbits were killed 1 week after operation to obtain rectovaginal fistula specimens,and the formation of rectovaginal fistula was observed by naked eye.Results The animal model of rectovaginal fistula was successfully established in 8 experimental rabbits.The operation process was smooth,with an average time of(1.63±0.70)minutes.The rabbits were generally in good condition after operation.The magnet was discharged from the body at(4.63±0.99)day after operation,and the rectovaginal fistula specimens were obtained 1 week after operation,and the rectovaginal fistula was well formed by naked eye observation.Conclusion The establishment of rabbit rectovaginal fistula model by magnetic compression technique has the advantages of simple operation and high success rate of model preparation.

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 explore the prevalence and independent associated factors of vascular calcification (VC) in non-dialysis chronic kidney disease (CKD) patients of stage 3-5.Methods:It was a single-center cross-sectional observational study. Non-dialysis stage 3-5 CKD patients ≥18 years old who were admitted to the Department of Nephrology, the First Affiliated Hospital of Sun Yat-sen University from May 1, 2022 to December 31, 2022 with VC evaluation were enrolled. The patients' general information, laboratory examination and imaging data were collected. Coronary artery calcification (CAC), thoracic aorta calcification (TAC), abdominal aorta calcification (AAC), carotid artery calcification and aortic valve calcification (AVC) were evaluated by cardiac-gated electron-beam CT (EBCT) scans, lateral lumbar x-ray, cervical macrovascular ultrasound and echocardiography, respectively. The differences in clinical data and the prevalence of VC at different sites of patients with different CKD stages were compared, and the prevalence of VC at different sites of patients in different age groups [youth group (18-44 years old), middle-aged group (45-64 years old) and elderly group (≥65 years old)] and patients with or without diabetes were compared. Multivariate logistic regression analysis was used to analyse the independent associated factors of VC for different areas.Results:A total of 206 patients aged (51±14) years were included, including 129 (62.6%) males. There were 44 patients with CKD stage 3 (21.4%), 51 patients with CKD stage 4 (24.8%), and 111 patients with CKD stage 5 (53.9%). CKD was caused by chronic glomerulonephritis [104 cases (50.5%)], diabetic kidney damage [35 cases (17.0%)], hypertensive kidney damage [29 cases (14.1%)] and others [38 cases (18.4%)]. Among 206 patients, 131 (63.6%) exhibited cardiovascular calcification, and the prevalence of CAC, TAC, AAC, carotid artery calcification, and AVC was 37.9%, 43.7%, 37.9%, 35.9% and 9.7%, respectively. The overall prevalence of VC in young, middle-aged and elderly patients was 24.6%, 73.6% and 97.4%, respectively. With the increase of age, the prevalence of VC in each site gradually increased, and the increasing trend was statistically significant (all P<0.001). The overall prevalence of VC in CKD patients with diabetes was 92.5% (62/67), and the prevalence of VC at each site in the patients with diabetes was significantly higher than that in the patients without diabetes (all P<0.001). Multivariate logistic regression analysis revealed that age (every 10 years increase, OR=2.51, 95% CI 1.77-3.56, P<0.001), hypertension ( OR=5.88, 95% CI 1.57-22.10, P=0.009), and diabetes ( OR=4.66, 95% CI 2.10-10.35, P<0.001) were independently correlated with CAC; Age (every 10 years increase, OR=6.43, 95% CI 3.64-11.36, P<0.001) and hypertension ( OR=6.09, 95% CI 1.33-27.84, P=0.020) were independently correlated with TAC; Female ( OR=0.23, 95% CI 0.07-0.72, P=0.011), age (every 10 years increase, OR=3.90, 95% CI 2.42-6.29, P<0.001), diabetes ( OR=5.37, 95% CI 2.19-13.19, P<0.001) and serum magnesium ( OR=0.01,95% CI 0-0.35, P=0.014) were independently correlated with AAC. Moreover, age and diabetes were independently correlated with carotid artery calcification, AVC and overall VC Conclusions:The prevalence of VC in non-dialysis CKD patients of stage 3-5 is 63.59%, of which CAC reaches 37.9%, TAC is the most common one (43.7%), while AVC is the least one (9.7%). Age and diabetes are the independent associated factors for VC of all sites except TAC, while hypertension is an independent associated factor for both CAC and TAC.

Objective To explore the application value of T2*mapping sequence combined with texture feature indicatoror in the diagnosis of postmenopausal osteoporosis(PMOP)in women.Methods The clinical data of 50 PMOP patients admitted to some hospital from March 2019 to April 2021(enrolled into an osteoporosis group)were analyzed retrospectively,and another two groups were established including a normal bone mineral density(BMD)group composed of 50 postmenopausal physical examiners with normal BMD(BMD＞120 mg/cm3)and a reduced BMD group consisting of 50 postmenopausal women with decreased BMD(80 mg/cm3＜BMD＜120 mg/cm3).All the 3 groups underwent magnetic resonance lumbar spine conventional sequence and T2(mapping scanning and image texture feature extraction,which were compared in terms of lumbar T2*value and texture feature indicators including energy,contrast,correlation,deficit distance and entropy.Spearman correlation analysis was used to analyze the correlation between lumbar spine T2*values,texture feature indicators and the occurrence of POMP in women,independent predictors of the occurrence of PMOP in women were determined by multifactorial logistic regression analysis,the diagnostic efficacy of T2*mapping sequence combined with texture feature indicatoror for PMOP was analyzed using ROC curves,and a column-line diagram prediction model for POMP occurrence was constructed and validated.Results There were significant differences in T2*value,energy,contrast,correlation,deficit distance and entropy among the groups(P＜0.05).Spearman correlation analysis showed that with the occurrence of POMP lumbar spine T2*value,contrast and entropy were significantly positively correlated,while energy,correlation and deficit distance were significantly negatively correlated(P＜0.05).T2*value,energy,contrast,correlation,deficit distance and entropy were all independent predictors of the occurrence of POMP(P＜0.05).T2*mapping sequence combined with texture feature indicatoror behaved better than any single indicator in AUC,sensitivity and specificity.The column-line diagram prediction model predicted a 75.00％probability of POMP in women,which was validated with advantages ind1iscrimination,calibration and net benefit rate.Conclusion Magnetic resonance T2*mapping sequence combined with texture feature indicator behaves well in diagnosing POMP of women,and T2*value,energy,contrast,correlation,deficit distance and entropy can be used as sensitive indicators for clinical screening of people at high risk for POMP.[Chinese Medical Equipment Journal,2024,45(8):68-72]

Further evidence is needed to explore the impact of high-altitude environments on the neurologic function of neonates.Non-invasive techniques such as cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography can provide data on cerebral oxygenation and brain electrical activity.This study will conduct multiple cerebral near-infrared spectroscopy and amplitude-integrated electroencephalography monitoring sessions at various time points within the first 3 days postpartum for healthy full-term neonates at different altitudes.The obtained data on cerebral oxygenation and brain electrical activity will be compared between different altitudes,and corresponding reference ranges will be established.The study involves 6 participating centers in the Chinese High Altitude Neonatal Medicine Alliance,with altitude gradients divided into 4 categories:800 m,1 900 m,2 400 m,and 3 500 m,with an anticipated sample size of 170 neonates per altitude gradient.This multicenter prospective cohort study aims to provide evidence supporting the impact of high-altitude environments on early brain function and metabolism in neonates.[Chinese Journal of Contemporary Pediatrics,2024,26(4):403-409]

Objective To investigate the incidence rate,clinical characteristics,and prognosis of neonatal stroke in Shenzhen,China.Methods Led by Shenzhen Children's Hospital,the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022.The incidence,clinical characteristics,treatment,and prognosis of neonatal stroke in Shenzhen were analyzed.Results The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137,1/6 060,and 1/7 704,respectively.Ischemic stroke accounted for 75％(27/36);boys accounted for 64％(23/36).Among the 36 neonates,31(86％)had disease onset within 3 days after birth,and 19(53％)had convulsion as the initial presentation.Cerebral MRI showed that 22 neonates(61％)had left cerebral infarction and 13(36％)had basal ganglia infarction.Magnetic resonance angiography was performed for 12 neonates,among whom 9(75％)had involvement of the middle cerebral artery.Electroencephalography was performed for 29 neonates,with sharp waves in 21 neonates(72％)and seizures in 10 neonates(34％).Symptomatic/supportive treatment varied across different hospitals.Neonatal Behavioral Neurological Assessment was performed for 12 neonates(33％,12/36),with a mean score of(32±4)points.The prognosis of 27 neonates was followed up to around 12 months of age,with 44％(12/27)of the neonates having a good prognosis.Conclusions Ischemic stroke is the main type of neonatal stroke,often with convulsions as the initial presentation,involvement of the middle cerebral artery,sharp waves on electroencephalography,and a relatively low neurodevelopment score.Symptomatic/supportive treatment is the main treatment method,and some neonates tend to have a poor prognosis.

Objective:To investigate the effects of overexpression of Nkx2.5 gene on the anti apoptotic ability of bone marrow mesenchymal stem cells (BMSCs) and cardiac function after myocardial infarction.Methods:A cell ischemia model was established by culturing cells under oxygen glucose deprivation/reoxygenat (OGD/R) conditions. The experiment was divided into four groups: bone marrow mesenchymal stem cells cultured under normal conditions (BMSC group), BMSC group cultured under glucose and oxygen deprivation (BMSC+OGD/R group), overexpressed empty vector BMSC group cultured under glucose and oxygen deprivation(BMSC NC+OGD/R group), and overexpressed Nkx2.5 BMSC group cultured under glucose and oxygen deprivation (BMSC Nkx2.5+OGD/R group). The apoptosis rate of BMSCs in each group was detected via flow cytometry, and BMSC protein was extracted. The expression of caspase-3 and pro-caspase-3, caspase-8 and pro-caspase-8, caspase-9, and cytochrome C protein and expression of Nkx2.5 in the BMSCs of each group were detected by Western blot to determine the anti-apoptotic pathway in vitro. The model of myocardial infarction in mice was established by ligating the left anterior descending branch of coronary artery. The experiment was divided into five groups: sham surgery group, myocardial infarction untreated group, myocardial infarction tail vein injection of BMSC group, myocardial infarction tail vein injection of BMSC empty body group, myocardial infarction tail vein injection of BMSC overexpression Nkx2.5 group. The changes of cardiac function in mice were evaluated by echocardiography. Normal distribution econometric data were compared between groups using convenient analysis, and pairwise comparisons were conducted using LSD-t test. Results:The apoptosis rate of the BMSC+OGD/R group (12.98±1.24)% was higher than that of the BMSC group (7.82±0.42)%, and the difference was statistically significant ( P<0.001). The apoptosis rate of the BMSC NKx2.5+OGD/R group (11.26±0.22)% was lower than that of the BMSC+OGD/R group (12.98±1.24)% and the BMSC NC+OGD/R group (13.14±0.70)%, with statistically significant differences ( P<0.05). Compared to BMSC group ((0.36±0.08), (1.13±0.04), (0.36±0.06), (1.12±0.13), (1.23±0.08), (0.60±0.05), (0.67±0.14)), BMSC+OGD/R group ((1.05±0.10), (0.62±0.04), (1.07±0.09), (0.57±0.07), (0.55±0.08), (1.25±0.09), (0.71±0.04)) and BMSC NC+OGD/R group ((1.16±0.16), (0.64±0.06), (1.19±0.16), (0.56±0.06), (0.50±0.06), (1.28±0.06), (0.73±0.04)), the expression of Caspase-3 (0.72±0.08) and pro-caspase-3(0.89±0.09), Caspase-8 (0.63±0.08) and pro-caspase-8(0.85±0.12), Caspase-9 (0.87±0.09), cytochrome C (0.91±0.10), and Nkx2.5 (1.54±0.16) in BMSC Nkx2.5+OGD/R group was statistically significant (all P<0.05). In vivo experiments showed that the heart ejection fraction (29.05±7.07)% of mice treated with BMSC Nkx2.5 after myocardial infarction was significantly improved compared to the BMSC group (16.57±2.09)% and BMSC NC group (18.08±3.27)% (all P<0.05). Conclusion:BMSC Nkx2.5 may enhance the anti-apoptosis ability of BMSCs and improve cardiac function after myocardial infarction by inhibiting the death receptor pathway and the mitochondrial signal pathway .

Fluorescence anisotropy(FA)analysis has many advantages such as no requirement of separation,high throughput and real-time detection,and thus has been widely used in many fields,including biochemical analysis,food safety detection,environmental monitoring,etc.However,due to the small volume or mass of the target,its combination with the fluorescence probe cannot produce significant signal change.To solve this issue,researchers often use nanomaterials to enhance the mass or volume of fluorophore to improve the sensitivity.Nevertheless,this FA amplification strategy also has some disadvantages.Firstly,nanomaterials are easy to quench fluorescence.As a result,the FA value is easily influenced by light scattering,which reduces the detection accuracy.Secondly,fluorescent probes in most methods require complex modification steps.Therefore,it is necessary to develop new FA probes that do not require the amplification of volume and mass or modification.As a new kind of nanomaterials,luminescent metal-organic framework(MOF)has a large volume(or mass)and strong fluorescence emission.It does not require additional signal amplification materials.As a consequence,it can be used as a potential FA probe.This study successfully synthesized a lanthanide metal organic framework(Ce-TCPP MOF)using cerium ion(Ce3+)as the central ion and 5,10,15,20-tetra(4-carboxylphenyl)porphyrin(H2TCPP)as the ligand through microwave assisted method,and used it as a novel unmodified FA probe to detect phosphate ions(Pi).In the absence of Pi,Ce-TCPP MOF had a significant FA value(r).After addition of Pi,Pi reacted with Ce3+in MOF and destroyed the structure of MOF into the small pieces,resulting in a decrease in r.The experimental results indicated that with the increase of Pi concentration,the change of the r of Ce-TCPP MOF(Δr)gradually increased.The Δr and Pi concentration showed a good linear relationship within the range of 0.5-3.5 μmol/L(0.016-0.108 mg/L).The limit of detection(LOD,3σ/k)was 0.41 μmol/L.The concentration of Pi in the Jialing River water detected by this method was about 0.078 mg/L,and the Pi value detected by ammonium molybdate spectrophotometry was about 0.080 mg/L.The two detection results were consistent with each other,and the detection results also meet the ClassⅡwater quality standard,proving that this method could be used for the detection of Pi in complex water bodies.