Background The benchmark dose (BMD) method calculates the dose associated with a specific change in response based on a specific dose-response relationship. Compared with the traditional no observed adverse effect level (NOAEL) method, the BMD method has many advantages, and the 95% lower confidence limit of benchmark dose lower limit (BMDL) is recommended to replace NOAEL in deriving biological exposure limits. No authority has yet published any health-based guideline for rare earth elements. Objective To evaluate genotoxicity threshold induced by acute exposure to neodymium nitrate in mice using BMD modeling through micronucleus test and comet assay. Methods SPF grade mice (n=90) were randomly divided into nine groups, including seven neodymium nitrate exposure groups, one control group (distilled water), and one positive control group (200 mg·kg⁻¹ ethyl methanesulfonate), 10 mice in each group, half male and half female. The seven dose groups were fed by gavage with different concentrations of neodymium nitrate solution (male: 14, 27, 39, 55, 77, 109, and 219 mg·kg⁻¹; female: 24, 49, 69, 97, 138, 195, and 389 mg·kg⁻¹) twice at an interval of 21 h. Three hours after the last exposure, the animals were neutralized by cervical dislocation. The bone marrow of mice femur was taken to calculate the micronucleus rate of bone marrow cells, and the liver and stomach were taken for comet test. Results The best fitting models for the increase of polychromatophil micronucleus rate in bone marrow of female and male mice induced by neodymium nitrate were the exponential 4 model and the hill model, respectively. The BMD and the BMDL of female mice were calculated to be 31.37 mg·kg⁻¹ and 21.90 mg·kg⁻¹, and those of male mice were calculated to be 58.62 mg·kg⁻¹ and 54.31 mg·kg⁻¹, respectively. The best fitting models for DNA damage induced by neodymium nitrate in female and male mouse hepatocytes were the exponential 5 model and the exponential 4 model, respectively, and the calculated BMD and BMDL were 27.15 mg·kg⁻¹ and 11.99 mg·kg⁻¹ for female mice, and 16.28 mg·kg⁻¹ and 10.47 mg·kg⁻¹ for male mice, respectively. The hill model was the best fitting model for DNA damage of gastric adenocytes in both female and male mice, and the calculated BMD and BMDL were 36.73 mg·kg⁻¹ and 19.92 mg·kg⁻¹ for female mice, and 24.74 mg·kg⁻¹ and 14.08 mg·kg⁻¹ for male mice, respectively. Conclusion Taken the micronucleus rate of bone marrow cells, DNA damage of liver cells and gastric gland cells as the end points of genotoxicity, the BMDL of neodymium nitrate is 10.47 mg·kg⁻¹, which can be used as the threshold of genotoxic effects induced by acute exposure to neodymium nitrate in mice.

Important forensic diagnostic indicators of sudden death in coronary atherosclerotic heart dis-ease,such as acute or chronic myocardial ischemic changes,sometimes make it difficult to locate the ischemic site due to the short death process,the lack of tissue reaction time.In some cases,the de-ceased died of sudden death on the first-episode,resulting in difficulty for medical examiners to make an accurate diagnosis.However,clinical studies on coronary instability plaque revealed the key role of coronary spasm and thrombosis caused by their lesions in sudden coronary death process.This paper mainly summarizes the pathological characteristics of unstable coronary plaque based on clinical medi-cal research,including plaque rupture,plaque erosion and calcified nodules,as well as the influencing factors leading to plaque instability,and briefly describes the research progress and technique of the atherosclerotic plaques,in order to improve the study on the mechanism of sudden coronary death and improve the accuracy of the forensic diagnosis of sudden coronary death by diagnosing different patho-logic states of coronary atherosclerotic plaques.

Objective To observe the therapeutic effects and mechanisms of Guanyuan Mingmen Sequential Acupuncture on rats with premature ovarian insufficiency(POI)model.Methods Female SD rats were divided into the blank group,the model group,the protein kinase A(PKA)inhibitor(H89)+acupuncture group,and the acupuncture group,with 12 rats in each group.Except for the blank group,the POI model was prepared by gavage with Tripterygium Glycosides Tablets in the other three groups of rats.After the model was successfully established,the blank group and the model group were bundled once a day;in the acupuncture group,Guanyuan(RN4)point was taken during the intermotility period,and in the pre-motility period,Mingmen(DU4)point was taken;in the H89+acupuncture group,the intervention was performed in accordance with the acupuncture protocol of the acupuncture group,and H89 was injected intraperitoneally for 30 minutes prior to each acupuncture session.Continuous intervention was performed for 20 days.Samples were taken from each group of rats in the first estrus period and in proestrus period after intervention.Enzyme-linked immunosorbent assay(ELISA)was used to measure the levels of follicle stimulating hormone(FSH)and estradiol(E2)during the estrous phase,Western Blot was used to measure the protein expressions of follicle stimulating hormone receptor(FSHR)and aromatase P450(P450arom)during the estrous phase,and the activity of granulocytes during the estrous phase and the proestrus phase were measured using the cell-counting kit 8(CCK-8)method.The immunohistochemistry method was used to detect the protein expression of pre-motility proliferating cell nuclear antigen(PCNA).Results(1)Compared with the blank group,the serum FSH level of the model group and H89+acupuncture group was significantly increased(P＜0.01),and the E2 level was significantly decreased(P＜0.001);there was no difference between the FSH level of the H89+acupuncture group and that of the model group(P＞0.05),and the E2 level of the H89+acupuncture group was lower than that of the model group(P＜0.05);the FSH level of the acupuncture group was lower than that of the model group and that of the H89+acupuncture group(P＜0.05),had no difference with the blank group(P＞0.05),E2 level was significantly higher than the model group and H89+ acupuncture group(P＜0.01),still being lower than the blank group(P＜0.05).(2)The protein expressions of FSHR and P450arom in the model group and H89 + acupuncture group was lower than those in the blank group;the protein expression of FSHR in the H89 + acupuncture group was not different from that in the model group(P＞0.05),while the protein expression level of P450arom was lower than that in the model group(P＜0.05);the protein expression levels of FSHR and P450arom in the acupuncture group were higher than those in the model group and H89 + acupuncture group,but still lower than those in the blank group(P＜0.05).(3)Both GCs activity and average optical density value of PCNA in the model group and H89+acupuncture group were lower than the blank group(P＜0.05);both GCs activity and average optical density value of PCNA in the H89+acupuncture group were lower than the model group(P＜0.05);the activity of GCs and average optical density value of PCNA of the acupuncture group were significantly higher than that of the model group and H89+acupuncture group(P＜0.05 or P＜0.01).Conclusion Guanyuan Mingmen Sequential Acupuncture can regulate sex hormone levels,increase GCs activity and promote GCs cell proliferation by up-regulating protein expressions of follicle stimulating hormone receptor(FSHR)/cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)pathway FSHR,P450arom,thus improving POI.

Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

Objective To observe the clinical efficacy and safety of the combination of rasagiline tablets and pramipexole tablets in the treatment of patients with Parkinson's disease.Methods The Parkinson's disease patients were randomly divided into treatment and control groups.The control group received pramipexole tablets,starting at a dose of 0.375 mg per day,with subsequent increases of 0.75 mg per time every 5-7 days,reaching a final dose of 1.5 mg per day.For patients with persistent poor disease control,the frequency of administration could be adjusted to twice a day,with a maximum daily dose of ≤ 4.5 mg.The treatment group received oral rasagiline in addition to the treatment in the control group,at a dose of 1.0 mg per day,once daily(qd).Both groups of patients were treated for 6 months.The clinical efficacy,inflammatory factors,serological indicators and related scales,as well as the occurrence of adverse drug reactions were compared between the two groups.Results The control group consisted of 67 participants,and the treatment group consisted of 68 participants,with no dropouts in either group.After treatment,the total effective rates of the treatment and control groups were 88.24％(60 cases/68 cases)and 74.63％(50 cases/67 cases)with significant difference(P＜0.05).After treatment,the levels of interferon-γ in treatment and control groups were(4.38±0.74)and(5.20±1.06)mg·L-1;the levels of interleukin-1 β were(0.33±0.05)and(0.59±0.12)ng·L-1;the levels of glutathione peroxidase were(108.24±11.30)and(92.88±9.79)U·μg-1;the modified Webster symptom scores were(7.26±1.05)and(13.15±3.25)points;the levels of γ-aminobutyric acid(GABA)were(278.14±41.32)and(241.86±35.04)mmol·L-1;the levels of insulin growth factor-1(IGF-1)were(170.25±20.34)and(145.18±16.51)ng·L-1,and the differences were statistically significant(all P＜0.05).The main adverse drug reactions of 2 groups were nausea and vomiting,drowsiness and dizziness.The total incidences of adverse drug reactions in treatment and control groups were 11.76％and 8.96％without significant difference(P＞0.05).Conclusion The combination of rasagiline tablets and pramipexole tablets in the treatment of patients with Parkinson's disease has shown definite clinical efficacy.It can alleviate oxidative stress and inflammatory reactions,relieve motor symptoms,regulate the expression levels of serum GABA and IGF-1,and does not significantly increase the incidence of adverse drug reactions.

The analysis of nano-micro nuclear particles has attracted significant attention due to the crucial role of their elemental and isotopic characteristics in tracing the origins of particulate matter and assessing its potential risks to human health and the environment.However,challenges persist in obtaining accurate and consistent element profiles and ratios for small-sized nanoparticles due to their low level and the transient nature.In this study,a high-speed digital oscilloscope was integrated with multiple collector inductively coupled plasma mass spectrometry(MC-ICP-MS)to develop a high time-resolution"Event-triggered signal capture"(ETSC)system for single particle analysis.This innovative approach enabled the analysis of element/isotope within rare earth nanoparticles at ag-fg level.The ETSC accurately recorded the complete profile of single particle,event captured by the electron multiplier with nanosecond time resolution,allowing for high-sensitivity element analysis and high-precision isotope analysis of single particles.The results demonstrated that the ETSC system could achieve quantitative analysis of ag levels of ytterbium(Yb)in 50-nm rare earth-doped particles,with a detection limit as low as 38 ag for Yb.Moreover,the isotopic precision of single particle analysis for 173/171Yb could reach 0.047(standard deviation),and the standard error for isotopic analysis of multiple particles could achieve a level of 2‰-3‰(permil)for 173/171Yb.Finally,the capability of ETSC system to analyze environmental samples was demonstrated through the analysis of doped ytterbium oxide nanoparticles.All these findings demonstrated that the ETSC provided a unique method for elemental and isotopic analysis of single nuclear particles.

Objective:To explore the surgical technique and results of three-dimensional aortic valve anatomic repair for bicuspid aortic valve (BAV) with aortic regurgitation (AR).Methods:This is a retrospective case series study. From August 2021 to December 2023, 130 consecutive patients with BAV-AR underwent aortic valve anatomic repair at the Department of Cardiothoracic Surgery, Zhongshan Hospital, Fudan University,and the data were retrospectively analyzed. There were 115 males and 15 females, aged (38.6±11.7) years (range: 15 to 67 years). All patients received modified aortic root reconstruction, to do three-dimensional root remodeling, including the basal ring, sinus of Valsalva and sino-tubular junction simultaneously. Perioperative and follow-up data were collected and analyzed. Comparisons between groups were performed using independent samples t-test, Wilcoxon paired signed-rank test, or χ2 test. Results:No patient transferred to valve replacement during the operation. The cardiopulmonary bypass time ( M(IQR)) was 109(34) minutes (range:67 to 247 minutes), and the aortic cross-clamp time was 76(26) minutes (range: 32 to 158 minutes). Preoperative transesophageal echocardiography showed 123 patients (94.6%) presented with moderate or severe regurgitation. Immediately postoperative transesophageal echocardiography showed no regurgitation in 22 patients (16.9%), trace regurgitation in 81 patients (62.3%) and mild regurgitation in 27 patients (20.8%). Follow up was completed in all patients, with a follow-up of 5.5(9.4) months (range: 0.1 to 27.6 months). No mortality was observed during follow-up. Echocardiography was obtained in 112 patients at the latest follow-up, including no regurgitation in 4 patients (3.6%), trace regurgitation in 58 patients (51.8%), mild regurgitation in 45 patients (40.2%), moderate regurgitation in 4 patients (3.6%), and severe regurgitation in 1 patient (0.9%). Conclusion:For patients with BAV-AR who have good valve quality and no severe aortic sinus dilation, the recent outcomes of three-dimensional anatomical repair technique, focusing on overall remodeling of the aortic root, are satisfactory.

Objective:To explore the surgical technique and results of three-dimensional aortic valve anatomic repair for bicuspid aortic valve (BAV) with aortic regurgitation (AR).Methods:This is a retrospective case series study. From August 2021 to December 2023, 130 consecutive patients with BAV-AR underwent aortic valve anatomic repair at the Department of Cardiothoracic Surgery, Zhongshan Hospital, Fudan University,and the data were retrospectively analyzed. There were 115 males and 15 females, aged (38.6±11.7) years (range: 15 to 67 years). All patients received modified aortic root reconstruction, to do three-dimensional root remodeling, including the basal ring, sinus of Valsalva and sino-tubular junction simultaneously. Perioperative and follow-up data were collected and analyzed. Comparisons between groups were performed using independent samples t-test, Wilcoxon paired signed-rank test, or χ2 test. Results:No patient transferred to valve replacement during the operation. The cardiopulmonary bypass time ( M(IQR)) was 109(34) minutes (range:67 to 247 minutes), and the aortic cross-clamp time was 76(26) minutes (range: 32 to 158 minutes). Preoperative transesophageal echocardiography showed 123 patients (94.6%) presented with moderate or severe regurgitation. Immediately postoperative transesophageal echocardiography showed no regurgitation in 22 patients (16.9%), trace regurgitation in 81 patients (62.3%) and mild regurgitation in 27 patients (20.8%). Follow up was completed in all patients, with a follow-up of 5.5(9.4) months (range: 0.1 to 27.6 months). No mortality was observed during follow-up. Echocardiography was obtained in 112 patients at the latest follow-up, including no regurgitation in 4 patients (3.6%), trace regurgitation in 58 patients (51.8%), mild regurgitation in 45 patients (40.2%), moderate regurgitation in 4 patients (3.6%), and severe regurgitation in 1 patient (0.9%). Conclusion:For patients with BAV-AR who have good valve quality and no severe aortic sinus dilation, the recent outcomes of three-dimensional anatomical repair technique, focusing on overall remodeling of the aortic root, are satisfactory.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]