Biosensor analysis technology is a kind of technology with high specificity that can convert biological reactions into optical and electrical signals. In the development of drugs for Alzheimer's disease (AD), according to different disease hypotheses and targets, this technology plays an important role in confirming targets and screening active compounds. This paper briefly describes the pathogenesis of AD and the current situation of therapeutic drugs, introduces three biosensor analysis techniques commonly used in the discovery of AD drugs, such as surface plasmon resonance (SPR), biolayer interferometry (BLI) and fluorescence analysis technology, explains its basic principle and application progress, and summarizes their advantages and limitations respectively.

Objective To evaluate the value of miniprobe endoscopic ultrasound(EUS)in guiding endoscopic treatment of small-diameter(maximum diameter less than 1 cm)and low-grade(G1 grade)rectum neuroendocrine neoplasm(R-NEN),and to provide evidence and clues for its clinical application and further research.Methods The clinical data of 85 cases of low-grade(G1 grade)R-NEN with a maximum diameter of less than 1 cm who underwent endoscopic treatment in our center from January 2014 to December 2020 were retrospectively analyzed.The patients were divided into the EUS group(37 cases)and control group(48 cases)according to whether EUS was performed before endoscopic treatment.The positive rate of incision margin,the incidence of complications,the recurrence rate,the hospital stay,the cost of hospitalization and endoscopic therapy were compared between the two groups.Results The positive rate of incision margin in the EUS group was significantly lower than that in control group(P<0.05).There was no significant difference in the incidence of complications,tumor recurrence rate,hospital stay or hospital costs between the two groups(P>0.05).There was statistically significant difference in the endoscopic therapy between the two groups(P<0.05).Conclusion Evaluating the lesion depth of small-diameter and low-grade(G1 grade)R-NEN before surgery by miniprobe EUS and selecting endoscopic surgery according to its results of can significantly reduce the residual risk of resection margin tumors.

Objective To screen the key characteristic genes of metastatic nasopharyngeal carcinoma(mNPC)and analyze the immune cell infiltration in tumor microenvironment using machine learning algorithm.Methods Firstly,the training set GSE103611 was downloaded from the GEO database,and the data were subjected to differential expression gene(DEGs)screening,Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genome(KEGG)and immune cell infiltration analysis.Second,the predicted genes in DEGs were screened by least absolute shrinkage and selector operation(LASSO)regression,and the characteristic genes were screened by using the expression level of the predicted genes and receiver operating characteristic(ROC).Third,the correlation between characteristic genes and immune cells was further analyzed to determine the key characteristic genes.Finally,the expression levels of key characteristic genes and ROC were verified using the reverse validation set GSE1245 data.Results A total of 136 DEGs were obtained,and their KEGG were mainly enriched in cytochrome P450,tumor necrosis factor(TNF)signaling pathway,prion disease,EB virus infection,and other pathways.GO was mainly enriched in the negative regulatory processes of peptide-based tyrosine phosphorylation modification,viral gene expression,and B cell and leukocyte activation.The difference in the degree of infiltration of the 22 immune cells in nasopharyngeal carcinoma(NPC)and mNPC was not significant.Two key characteristic genes(DAZ1 and SCCPDH)of mNPC were finally obtained by LASSO regression,and they were significantly correlated with immune cells in the mNPC microenvironment(P＜0.05).In the reverse validation data set,the differential expressions of DAZ1 and SCCPDH between non-NPC(nNPC)and NPC groups were not significant(P＞0.05),and the AUC values of ROC of both were less than 0.6.Conclusion DAZ1 and SCCPDH are the key characteristic genes of mNPC and can be used as important markers for mNPC and immunotherapy.

Human brain banks use a standardized protocol to collect,process and store post-mortem human brains and related tissues,along with relevant clinical information,and to provide the tissue samples and data as a resource to foster neuroscience research according to a standardized operating protocols(SOP).Human brain bank serves as the foundation for neuroscience research and the diagnosis of neurological disorders,highlighting the crucial rule of ensuring the consistency of standardized quality for brain tissue samples.The first version of SOP in 2017 was published by the China Human Brain Bank Consortium.As members increases from different regions in China,a revised SOP was drafted by experts from the China Human Brain Bank Consortium to meet the growing demands for neuroscience research.The revised SOP places a strong emphasis on ethical standards,incorporates neuropathological evaluation of brain regions,and provides clarity on spinal cord sampling and pathological assessment.Notable enhancements in this updated version of the SOP include reinforced ethical guidelines,inclusion of matching controls in recruitment,and expansion of brain regions to be sampled for neuropathological evaluation.

Objective:To construct a multi-sequence MRI radiomics combined with KRAS mutation nomogram model to predict the efficacy of pathological complete response (pCR) in patients with rectal cancer after neoadjuvant chemoradiotherapy.Methods:This study was a case-control study. A total of 126 patients with rectal cancer who were treated with neoadjuvant chemoradiotherapy in the Second Affiliated Hospital of Harbin Medical University from June 2020 to December 2023 were retrospectively collected. The pathological response of the postoperative specimens was graded, with 64 cases of pCR and 62 cases of non-pCR. KRAS gene detection was performed on the pathological tissues before neoadjuvant chemoradiotherapy. Among the patients, 34 cases had KRAS mutants and 92 cases had KRAS wild-types. The 126 patients were randomly divided into a training set and a validation set at a ratio of 8∶2 by the random number method, with 101 and 25 cases, respectively. The difference in KRAS mutation status between the pCR group and the non-pCR group was compared by the χ2 test. The radiomic features were extracted from the baseline T 2WI, diffusion-weighted imaging, and apparent diffusion coefficient images of the patients. The optimal radiomic features were screened out to establish the radiomics model. The radiomics-KRAS joint model was constructed by logistic regression, and a nomogram was drawn. The application efficiency of the model was evaluated by the receiver operating characteristic curve and calibration curve. Results:There was a statistically significant difference in KRAS mutation between the pCR group and the non-pCR group in the training set ( χ2=4.69, P=0.032). Ten radiomics features were screened out in MRI images to establish the radiomics model. In the training set and validation set, the areas under the curve (AUC) of KRAS mutation, radiomics model and radiomics-KRAS nomogram model for evaluating pCR after neoadjuvant chemoradiotherapy were 0.665 (95% CI 0.592-0.757), 0.746 (95% CI 0.651-0.895) and 0.818 (95% CI 0.742-0.934), respectively, and the AUCs of the validation set were 0.613 (95% CI 0.582-0.755), 0.738 (95% CI 0.627-0.839) and 0.833 (95% CI 0.768-0.961), respectively. The results of DeLong test showed that the AUC of radiomics-KRAS nomogram model was higher than that of KRAS mutation and radiomics model, and the difference was statistically significant ( Z=0.58, 0.63, P=0.024, 0.022 in the training set; Z=0.54, 0.61, P=0.018, 0.035 in the validation set). The calibration curve showed that the predicted probability of the radiomics-KRAS nomogram model was consistent with the actual probability. Conclusions:The multi-sequence MRI radiomics combined with the KRAS mutation nomogram model has the best efficacy in predicting pCR in patients with rectal cancer after neoadjuvant chemoradiotherapy, and has good practical application value.

This study was aimed at studying the phenotypic and molecular characteristics of a Salmonella Grumpensis isolate from a patient with diarrhea in Shanghai,to provide evi-dence for the prevention of salmonellosis.Biochemical identifi-cation,serum agglutination testing,antimicrobial susceptibility testing,and whole genome sequencing(WGS)were performed on isolate 2023JD76.Global Salmonella Grumpensis genome sequences were searched and downloaded for serotyping predic-tion,multilocus sequence typing(MLST),prediction of anti-microbia resistance genes and virulence genes,and phylogenetic analysis of 2023JD76.The 2023JD76 strain was identified as Salmonella Grumpensis(13,23:d:1,7)with ST2060,and was susceptible to 20 antimicrobial agents.Strain 2023JD76 carried the aminoglycoside resistance gene aac(6')-Iaa and five types of virulence genes:the adhesion genes csg and rat;the secretion and transport genes sip and inv;the typhoid toxin genes cdt and plt;the invasive gene nutrient metabolism factor mgt;and the antimicrobial peptide resistance factor mig.Global S.Grumpensis strains harbored ten types of antimicrobial resistance genes whose prevalence ranged from 58.33％to 100％.The global genome sequences of S.Grumpensis were divided into two lineages.Lineage I was dominated by ST751(88.89％,16/18),and lineage Ⅱ was dominated by ST2060(89.47％,17/19).The genome sequence of strain 2023JD76 belonged to lineage Ⅱ,and was closely related to the genome sequences from human fecal and human cerebrospinal fluid.This study provides the first report of a S.Grumpensis isolate from the stool of a patient with diarrhea in China.Considerable variability in antimicrobial resistance genes was observed among genome sequences from different sources,and the strains harbored a substantial number of virulence genes.Enhanced surveillance should be emphasized to prevent a potential risk of global dissemination.

The usage of pesticides can enhance the production of crops,but their overuses may be hazardous to both people health and the environment.Thus,it is of great significance to develop effective methods to detect pesticides.Metal nanoclusters(MNCs)have become increasingly popular in analytical sensing areas because of their miniscule size,high stability,ease of manufacturing and good biocompatibility.They have exhibited great potential in the field of pesticides detection.In this paper,the detection methods of pesticides by using MNCs and their development in detection of organophosphorus pesticides,organic nitrogen pesticides,organochlorine pesticides and other types of pesticides were reviewed.Finally,the development prospects were discussed.

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]

Objective To explore early diagnostic biological markers for Leigh syndrome caused by the m.8993T>G mutation.Methods A retrospective analysis was performed on the clinical data of four children diagnosed with m.8993T>G mutation-related mitochondrial disease at the Children's Hospital of Chongqing Medical University from January 2014 to January 2024.Additionally,a literature review was conducted.Results All four children had plasma amino acid and acylcarnitine analyses that revealed decreased citrulline levels,and one child was initially identified through neonatal genetic metabolic disease screening.According to the literature review,there were 26 children with mitochondrial disease and hypocitrullinemia caused by the m.8993T>G mutation(including the four children in this study).Among these,12 children exhibited clinical phenotypes of Leigh syndrome or Leigh-like syndrome,while 18 children were identified with hypocitrullinemia and/or elevated levels of 3-hydroxyisovalerylcarnitine(C5-OH)during neonatal genetic metabolic disease screening.Conclusions Hypocitrullinemia may serve as a potential biomarker for the early diagnosis of m.8993T>G mutation-associated Leigh syndrome,detectable as early as during neonatal genetic metabolic disease screening.

Objective To study the role of sphingosine-1-phosphate(S1P)signal on the proliferation of breast cancer BT549 cells.Methods Cells were divided into control group and experimental group,experimental group were treated with 0.1,1.0,10.0 μmol·L-1 S1P receptor agonist SEW2871 for 72 h.Control group was cultured with 0.1％fetal bovine serum.Cell proliferation was detected by methyl thiazolyl tetrazolium(MTT)assay.Cell models of overexpressing S1P receptors in BT549 were divided into three groups:blank plasmid group(LUC),wild type S1P receptor overexpression group(WT),S1P receptor phosphorylation site mutation overexpression group(MUT);the proliferation ratio was detected by MTT,the number of cell clones was counted by colony formation experiment.S1P antagonist W146(10 μmol·L-1)and protein kinase(AKT)signaling inhibitor MK2206(90 nmol·L-1)were used to detect the role of S1P signaling in the proliferation of breast cancer cells.The expression of phosphorylate signal transducer and activator of transcription 3(p-STAT3),c-Myc proteins were detected by Western blot.Results The growth ratio of BT549 cells in control group and 0.1,1.0,10.0 μmol·L-1experimental groups were 1.00±0.03,1.13±0.06,1.06±0.10 and 1.07±0.03,0.1 μmol·L-1 SEW2871 promot the cell proliferation(P＜0.05).Compared between WT group,MUT group and LUC group,the growth rate and the number of clonal colonies were increased after overexpression of S1P receptor(all P＜0.05).The growth ratio of BT549 cells after treatment with W146 and MK2206 in the LUC group,WT group and MUT group were 1.25±0.12,1.31±0.03,1.43±0.14 and 0.87±0.15,0.77±0.03,0.88±0.02.Compared between MUT group,WT group and corresponding DMSO group,the differences were statistically significant(all P＜0.01).The number of cell clony formation number after treatment with W146 were 65.65±5.12,141.48±5.63 and 93.64±5.14;compared between MUT,WT group and corresponding DMSO group,the differences were statistically significant(all P＜0.05).The relative protein expression levels of p-STAT3 in LUC group,WT group and MUT group were 0.67±0.04,0.69±0.08 and 0.81±0.06,the relative protein expression levels of proto-oncogene c-Myc were 1.69±0.03,0.70±0.10 and 0.67±0.07,compared between WT group,MUT group and corresponding DMSO group,the difference was statistically significant(P＜0.05).Conclusion S1P signaling can promote proliferation in breast cancer BT549 cells,and the mechanism could be related to AKT and STAT3 signaling pathway.