OBJECTIVE To develop a method for the determination of tacrolimus （TAC） concentration in human whole blood and to apply it in clinical therapeutic drug monitoring. METHODS Whole blood samples were processed by protein precipitation with methanol. The determination was performed using liquid chromatography-tandem mass spectrometry （LC-MS/MS）， with ascomycin serving as the internal standard. Chromatographic separation was carried out on a Kinetex F5 100Å column with a mobile phase consisting of 0.1 mmol/L ammonium acetate containing 0.2 mmol/L formic acid and methanol. Gradient elution was performed at a flow rate of 0.4 mL/min. The injection volume was 5 μL. Detection was conducted using multiple reaction monitoring （ m / z 821.6→768.6 for TAC； m / z 809.4→756.1 for ascomycin） with an electrospray ionization source in positive ion mode. The study focused on 86 whole blood samples collected from 83 pedi atric patients who received TAC therapy at Children’s Hospital of Nanjing Medical University from September 1 to 30， 2025. The aforementioned method was employed to measure the TAC concentration in the whole blood samples. The correlation and agreement between the aforementioned method and the traditional enzyme multiplied immunoassay technique （EMIT） were evaluated through Spearman correlation analysis， Bland-Altman analysis， and Passing-Bablok regression analysis. RESULTS The linear range of TAC was 0.5-100 ng/mL； the evaluation results for accuracy， precision， extraction recovery， matrix effect， and stability tests all met the relevant requirements. Clinical application results showed that the median concentration of TAC in pediatric whole blood measured by LC-MS/MS and EMIT methods were 4.4 and 4.0 ng/mL， respectively. Moreover， the two methods exhibited a strong correlation （correlation coefficient of 0.848 1） and good agreement （average relative deviation of 6.5%）. CONCLUSIONS A reliable LC-MS/MS method for the determination of TAC concentration in human whole blood is successfully established. This method demonstrates strong correlation and good agreement with the EMIT method， making it suitable for clinical therapeutic drug monitoring.

Objective: To reveal the molecular biological mechanism of a rare Dc-variant individual using PacBio third-generation sequencing technology. Methods: ABO and Rh blood type identification, DAT, unexpected antibody screening and D antigen enhancement test were conducted by serological testing. The absorption-elution test was used to detect the e antigen. RHCE gene typing was performed by PCR-SSP, and the 1-10 exons of RHCE were sequenced by Sanger sequencing. The full-length sequences of RHCE, RHD and RHAG were detected by PacBio third-generation sequencing technology. Results: Serological findings: Blood type O, Dc-phenotype, DAT negative, unexpected antibody screening negative; enhanced D antigen expression; no detection of e antigen in the absorption-elution test. PCR-SSP genotyping indicated the presence of only the RHCE c allele. Sanger sequencing results: Exons 5-9 of RHCE were deleted, exon 1 had a heterozygous mutation at c. 48G/C, and exon 2 had five heterozygous mutations at c. 150C/T, c. 178C/A, c. 201A/G, c. 203A/G and c. 307C/T. Third-generation sequencing results: RHCE genotype was RHCE 02N. 08/RHCE-D(5-9)-CE; RHD genotype was RHD 01/RHD 01; RHAG genotype was RHAG 01/RHAG 01 (c. 808G>A and c. 861G>A). Conclusion: This Dc-individual carries the allele RHCE 02N. 08 and the novel allele RHCE-D(5-9)-CE. The findings of this study provide data support and a theoretical basis for elucidating the molecular mechanisms underlying RhCE deficiency phenotypes.

OBJECTIVE To explore the association of postoperative biliary tract infection with expressions of soluble cluster of differentiation 14 subtype(sCD14-ST),procalcitonin(PCT),Toll-like receptor(TLR)4 and TLR2 in malignant obstructive jaundice(MOJ)patients undergoing percutaneous transhepatic cholangial drainage(PTCD).METHODS A total of 105 MOJ patients who underwent PTCD in Shengjing Hospital Affiliated to China Medical University form Nov.2021 to Nov.2023 were enrolled in the study and were divided into the infection group with 31 cases and the non-infection group with 74 cases according to the status of postoperative biliary tract infection.The etiological characteristics and drug resistance rates of the infection group were statistically analyzed.The levels of peripheral blood sCD14-ST,PCT,TLR4 and TLR2 were compared between the two groups,and the values of sCD14-ST,PCT,TLR4 and TLR2 in diagnosis of postoperative biliary tract infection in the MOJ patients under-going PTCD wee analyzed.RESULTS Totally 53 strains of pathogens were isolated from 31 patients of the infec-tion group,among which gram-negative bacteria were dominant.Escherichia coli and Enterococcus faecalis were respectively the major species of the gram-negative and gram-positive bacteria.The E.coli was mainly resistant to ampicillin and sensitive to imipenem;the E.faecalis was mainly resistant to ciprofloxacin,tetracycline,erythro-mycin and was sensitive to vancomycin.There were significant differences in the levels of sCD14-ST,PCT,TLR4 and TLR2 between the two groups(P＜0.05);the sCD14-ST level of the infection group was(41.12±13.14)ng/ml,higher than(29.35±9.17)ng/ml of the non-infection group(t=5.248,P＜0.001).The area under the curve(AUC)value of the joint detection of sCD14-ST,PCT,TLR4 and TLR2 was higher than that of the single detec-tion in diagnosis of postoperative biliary tract infection in the MOJ patients undergoing PTCD(P＜0.05).CONCLUSIONS The gram-negative bacteria are the major pathogens isolated from the MOJ patients with postop-erative biliary tract infection.Imipenem and vancomycin are recommended for treatment of the E.coli and E.fae-calis infections.The patients show abnormal expressions of sCD14-ST,PCT,TLR4 and TLR2.The joint detec-tion of the four indexes has high diagnostic value.

The principle and composition of Philips Ingenia Series MRI scanners were introduced.Three common faults of Philips Ingenia Series MRI scanners were analyzed in terms of the phenomenon,cause and elimination measure.References were provided for clinical engineers to treat similar faults.[Chinese Medical Equipment Journal,2025,46(6):116-120]

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Alzheimer's disease(AD)is the most common cause of cognitive impairment in the elderly,and the formation of intracellular neurofibrillary tangles(NFT)due to the hyperphos-phorylation of Tau is one of its important pathological features.Compared to β-amyloid,the hyperphosphorylation of Tau and the resulting NFT are more closely related to the decline in cognitive ability.This review focuses on anti-AD drugs targeting Tau,em-phasizing the latest progress in inhibiting the hyperphosphoryla-tion of Tau protein,alleviating the aggregation of Tau protein,re-ducing the cytoskeletal damage caused by the hyperphosphoryla-tion of Tau protein by stabilizing microtubules,and immunothera-py,in the hope of providing new insights into drug research for AD and related cognitive disorders associated with Tau protein.

Central nervous system(CNS)degenerative disorders refer to a spectrum of pathological alterations triggered by struc-tural damage to cerebral neural tissues,clinically manifested as diverse neurological dysfunction syndromes,including multiple sclerosis(MS),neurodegenerative diseases(NDs),and ische-mic stroke.The hallmark pathological features of these disorders involve irreversible neuronal damage and decompensation of functional neural networks,ultimately leading to progressive neurological deficits.Notably,with the accelerating global popu-lation aging,the incidence of these diseases has surged signifi-cantly.According to WHO statistics,they now rank among the top three global causes of disability and mortality.Current re-search has confirmed that the pathogenesis of CNS degenerative disorders exhibits high heterogeneity,encompassing multifaceted pathophysiological processes such as genetic predisposition,oxi-dative stress,protein misfolding,and metabolic dysregulation.This intricate pathogenic network not only complicates clinical differential diagnosis but also poses substantial challenges to the development of precision therapeutic strategies.Importantly,re-cent studies have revealed that mitochondrial homeostasis disrup-tion-induced inflammatory cascades(termed mitochondrial in-flammation)play a pivotal regulatory role in neurodegenerative progression.Key molecular mechanisms include impaired mito-phagy,aberrant mitochondrial DNA(mtDNA)release and NL-RP3 inflammasome activation.This review systematically deci-phers the molecular regulatory network of mitochondrial inflam-mation,with a focus on its biological effects in critical pathologi-cal events such as blood-brain barrier disruption,microglial hy-peractivation and neuronal apoptosis.The overarching aim is to provide a theoretical foundation for developing innovative thera-peutic strategies targeting mitochondrial homeostasis restoration.

Objective To evaluate the impact of healthcare-associated infection(HAI)control culture construction on the hand hygiene(HH)compliance of health care workers(HCWs),and provide a basis for strengthening HAI management.Methods HCWs in a hospital in Xi'an City were selected as the research objects.On the occasion of World HH Day,a series of publicity activities on HH as well as HAI prevention and control were held.Pre-activi-ties period was April 1-30,2024.During May 1-31,2024,a series of publicity activities on HH as well as HAI prevention and control were carried out.The post-activities investigation period was June 1-30,2024.During De-cember 1-31,2024,HH compliance survey was carried out in batches in the whole hospital(including key depart-ments).HH compliance at different stages was compared.Results After a series of publicity activities on HH as well as HAI prevention and control,HCWs'HH compliance rate was improved.HH compliance rate of nursing staff increased from 70.15％to 85.11％;HH compliance rate of HCWs before contacting with patients increased from 47.83％to 78.38％;both with statistically significant difference(both P＜0.05).During December 1-31,2024,a batch survey on HH compliance of the whole hospital(including key departments)showed that the HH compliance rates of medical and nursing staff in key departments were higher than those of the whole hospital,and the differences were statistically significant(all P＜0.05).HH compliance rates before aseptic operation and after contacting with patients in key departments were both higher than those of the whole hospital,and the differences were statistically significant(all P＜0.05).Conclusion Publicity activities on HH as well as HAI prevention con-trol can improve HH compliance rate of HCWs.HAI managers should pay more attention to the general depart-ments and improve HH compliance rate of HCWs.

Objective To investigate changes in the pro-inflammatory mediator S100A8/9 and NLRP3/Caspase-1/IL-1β pathway in a rat kidney-aging model induced by D-galactose.Methods Twelve SD rats were divided into control and D-galactose groups,and injected subcutaneously in the back of the neck with D-galactose(150 mg/kg)to establish a rat model of kidney aging.Kidney samples were collected under anesthesia after 8 weeks.Kidneys were stained for senescence-associated beta-galactosidase(SA-β-Gal),mRNA expression levels of the aging-related genes p21,p16,and p53 were detected by quantitative reverse transcription-polymerase chain reaction(qRT-PCR),and histopathological changes were observed by hematoxylin-eosin(HE)and Masson staining.Serum urea nitrogen and creatinine,and catalase(CAT),glutathione peroxidase(GSH-PX),superoxide dismutase(SOD),and malondialdehyde(MDA)levels in the kidney tissues were detected.Reactive oxygen species(ROS)were detected by dihydroethdium staining and protein expression levels of collagen Ⅲ,α-smooth muscle actin(α-SMA),Protein expression of S100A8/9 was detected by immunofluorescence,and transforming growth factor(TGF)-β1 levels in kidney tissues and key factors in the NLRP3/Caspase-1/IL-1β inflammatory pathway were detected by Western Blot.A renal senescence model using HK-2 cells was constructed using H2O2 in vitro,and expression levels of the senescence proteins p21 and p16 and mRNA expression levels of the inflammatory factors IL-18 and tumor necrosis factor-α(TNF-α)were detected.Cell senescence was observed by SA-β-Gal staining.The effects of the S100A8/9 inhibitor paquinimod on expression levels of S100A8/9 and NLRP3/Caspase-1/IL-1β pathway-related proteins in the aging model were also detected.Results mRNA levels of the aging genes p21,p16,and p53 in kidney tissues were significantly increased in rats in the D-galactose group compared with the control group(P＜0.01),and SA-β-Gal staining showed a significant increase in senescent cells(P＜0.01).Serum blood urea nitrogen and creatinine levels increased(P＜0.05),CAT,GSH-PX,and SOD activities decreased(P＜0.01),while MDA activity increased in the D-galactose group(P＜0.01).Collagen Ⅲ,α-SMA,and TGFβ1 expression and the ROS content in tissues increased(P＜0.05).Glomeruli were atrophied or absent in the D-galactose group,the lumens of the renal sacs and renal tubules were enlarged,the nuclei were deeply stained and constricted,and numerous collagen fibers were deposited.Levels of S100A8 and S100A9 protein(P＜0.01),as well as NLRP3,Caspase-1,and IL-1β increased(P＜0.05).Paquinimod alleviated HK-2 cell senescence and decreased expression levels of the senescence proteins p21 and p16,and mRNA levels of the inflammatory factors IL-18 and TNF-α(P＜0.05,P＜0.01).The number of senile cells was also decreased,shown by SA-β-Gal staining(P＜0.01).Paquinimod also inhibited the protein expression of S100A8 and S100A9(P＜0.01)and NLRP3,Caspase-1,and IL-1β(P＜0.05 or P＜0.01).Conclusions S100A8/9 participates in the chronic inflammatory response by activating the NLRP3/Caspase-1/IL-1β pathway,thereby promoting D-galactose-induced renal aging.