Membrane proteins are integral components of cellular membranes, accounting for approximately 30% of the mammalian proteome and serving as targets for 60% of FDA-approved drugs. They are critical to both physiological functions and disease mechanisms. Their functional protein-protein interactions form the basis for many physiological processes, such as signal transduction, material transport, and cell communication. Membrane protein interactions are characterized by membrane environment dependence, spatial asymmetry, weak interaction strength, high dynamics, and a variety of interaction sites. Therefore, in situ analysis is essential for revealing the structural basis and kinetics of these proteins. This paper introduces currently available in situ analytical techniques for studying membrane protein interactions and evaluates the characteristics of each. These techniques are divided into two categories: label-based techniques (e.g., co-immunoprecipitation, proximity ligation assay, bimolecular fluorescence complementation, resonance energy transfer, and proximity labeling) and label-free techniques (e.g., cryo-electron tomography, in situ cross-linking mass spectrometry, Raman spectroscopy, electron paramagnetic resonance, nuclear magnetic resonance, and structure prediction tools). Each technique is critically assessed in terms of its historical development, strengths, and limitations. Based on the authors’ relevant research, the paper further discusses the key issues and trends in the application of these techniques, providing valuable references for the field of membrane protein research. Label-based techniques rely on molecular tags or antibodies to detect proximity or interactions, offering high specificity and adaptability for dynamic studies. For instance, proximity ligation assay combines the specificity of antibodies with the sensitivity of PCR amplification, while proximity labeling enables spatial mapping of interactomes. Conversely, label-free techniques, such as cryo-electron tomography, provide near-native structural insights, and Raman spectroscopy directly probes molecular interactions without perturbing the membrane environment. Despite advancements, these methods face several universal challenges: (1) indirect detection, relying on proximity or tagged proxies rather than direct interaction measurement; (2) limited capacity for continuous dynamic monitoring in live cells; and (3) potential artificial influences introduced by labeling or sample preparation, which may alter native conformations. Emerging trends emphasize the multimodal integration of complementary techniques to overcome individual limitations. For example, combining in situ cross-linking mass spectrometry with proximity labeling enhances both spatial resolution and interaction coverage, enabling high-throughput subcellular interactome mapping. Similarly, coupling fluorescence resonance energy transfer with nuclear magnetic resonance and artificial intelligence (AI) simulations integrates dynamic structural data, atomic-level details, and predictive modeling for holistic insights. Advances in AI, exemplified by AlphaFold’s ability to predict interaction interfaces, further augment experimental data, accelerating structure-function analyses. Future developments in cryo-electron microscopy, super-resolution imaging, and machine learning are poised to refine spatiotemporal resolution and scalability. In conclusion, in situ analysis of membrane protein interactions remains indispensable for deciphering their roles in health and disease. While current technologies have significantly advanced our understanding, persistent gaps highlight the need for innovative, integrative approaches. By synergizing experimental and computational tools, researchers can achieve multiscale, real-time, and perturbation-free analyses, ultimately unraveling the dynamic complexity of membrane protein networks and driving therapeutic discovery.

Objective To describe the changing trend and related factors of prevalence rates of healthcare-associa-ted infection(HAI)in a tertiary hospital in the past 10 years,and analyze the influencing factors for HAI.Methods A cross-sectional survey on HAI was conducted for 10 consecutive years from 2013 to 2022(one day was selected as the survey day each year),data were collected.The distribution and related factors of prevalence rates of HAI were analyzed by trend-x2 test and Pearson correlation coefficient.Multivariate logistic regression and multilayer percep-tron(MLP)models were constructed to analyze the independent effect and significance of factors.Results From 2013 to 2022,the prevalence rates of HAI ranged from 4.66％to 8.07％in this hospital,showing a linear upward trend.The proportions of ICU patients and utilization rate of central venous catheters within 2 days before the sur-vey showed linear upward trends,while the proportion of patients with urinary catheters within 2 days before the survey and proportion of patients undergoing surgery within 30 days before the survey decreased.The MLP model revealed that the top 3 important factors for HAI were length of hospital stay＞10 days,admission in ICU,and in-dwelling central venous catheters within 2 days before the survey.Multivariate logistic regression model indicated that length of hospital stay＞10 days,indwelling central venous catheters or urinary catheters within 2 days before the survey,surgery within 30 days before the survey,and admission in ICU were independent influencing factors for HAI.Conclusion The incidence of HAI in this hospital presents a linear increase in recent 10 years,the causes should be further analyzed and the direction of intervention should be determined through targeted surveillance.Adopting trend test statistical analysis method,logistic regression,MLP multi-factor model can further explore the data value of HAI prevalence survey.

AIM: To investigate the expression changes of MMP-12 during the long-term axon regeneration induced by the lens injury after the optic nerve clamp trauma in sprague-dawley(SD)rats.METHODS: The optic nerve injury model and lens injury model of SD rats were established, and the 24 experimental animals were divided into control group; lens injury group; optic nerve injury group; lens injury combined with optic nerve injury group, with 6 rats in each group. Reference transcriptome sequencing was used to analyze the expression changes of differentially expressed genes in the injured optic nerve region, and relevant differentially expressed genes with high expression were screened. Quantitative real-time polymerase chain reaction(qRT-PCR)and enzyme-linked immunosorbent assay(ELISA)were used to quantify the expression changes of matrix metalloproteinase-12(MMP-12)in the injured optic nerve region.RESULTS: The Principal Component Analysis of transcriptome sequencing indicated that lens injury combined with optic nerve injury was the principal component of gene expression change. Analysis of gene expression differences showed that the expression of MMP-12 gene was up-regulated in the lens injury combined with optic nerve injury group. The mRNA expression level of MMP-12 in the lens injury combined optic nerve injury group was up-regulated compared with the control group, the optic nerve injury group and the lens injury group at 14d and 21d after successful modeling(P<0.05). At 7, 28d, there was no difference in expression among all groups. The protein expression level of MMP-12 in the lens injury combined with optic nerve injury group was up-regulated compared with the control group and optic nerve injury group at 7, 14 and 21d after successful modeling(P<0.05), and it was up-regulated in the lens injury group combined with optic nerve injury group compared with optic nerve injury group at 21d(P<0.05). At 28d, there was no difference in expression among all groups.CONCLUSION: The up-regulated expression of MMP-12 may be involved in the long-term regeneration of the optic nerve after lens injury.

The purpose was to discuss the infection status of human parainfluenza virus type 3 (HPIV-3) in children with acute respiratory tract infection(ARTI) in Qingdao, Shandong province, and to analyze the gene characteristics of HPIV-3 hemagglutinin-neuraminidase protein (HN). This study was a cross-sectional study. A total of 1 674 throat swab samples were collected randomly from children with ARTI, in the three hospitals (Qingdao Women and Children's Hospital, West Coast Branch of Affiliated Hospital of Qingdao University, Laoshan Branch of Affiliated Hospital of Qingdao University) from January 2018 to December 2019. Multiplex real-time fluorescence RT-PCR was performed to screen HPIV-3 positive specimens. For HPIV-3 positive specimens, nested PCR was used to amplify the full-length HN gene of HPIV-3. The HN gene was sequenced and compared with the representative strains of HPIV-3 in GenBank, and the phylogenetic tree was established. As results, this study collected 1 674 samples, in which there were 90 HPIV-3 positive samples showed and the detection rate was 5.37%. Among positive specimens, the number of samples from children under 6 years old was 88, accounting for 97.78%. HPIV-3 positive cases were mainly distributed in spring and summer. The full-length sequences of 44 HPIV-3 HN genes were obtained by nested PCR method. Sequence alignment and evolutionary analysis showed that the HPIV-3HN gene belonged to the C3a and C3b branches of C3 genotype, with 30 strains of subtype C3a and 14 strains of subtype C3b. The nucleotide and amino acid homology of the amplified 44 strains of the HPIV-3 HN gene in Qingdao were 97.0%-100.0% and 98.5%-100.0%, respectively. In conclusion, from 2018 to 2019, the C3a and C3b branches of HPIV-3 C3 genotype were circulating prevalent in Qingdao, Shandong province. HN gene variation rate was low, but showed certain regional characteristics in evolution.
Child ; Child, Preschool ; Cross-Sectional Studies ; Female ; Hemagglutinins ; Humans ; Neuraminidase ; Parainfluenza Virus 3, Human/genetics* ; Phylogeny ; Respiratory Tract Infections/epidemiology* ; Viral Proteins

Objective: To estimate the incidence of HIV-1 infection in men who have sex with men (MSM) in key areas of China through HIV-1 limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA), analyze the deviation from the actual results and identify influencing factors, and provided reference for improving the accuracy of estimation results. Methods: Based on the principle of the cohort randomized study design, 20 cities were selected in China based on population size and the number of HIV-positive MSM. The sample size was estimated to be 700 according to the HIV-1 infection rate in MSM. MSM mobile phone app. was used to establish a detection appointment and questionnaire system, and the baseline cross-sectional survey was conducted from April to November 2019. LAg-Avidity EIA was used to identify the recent infected samples. The incidence of HIV-1 infection was calculated and then adjusted based on the estimation formula designed by WHO. The influencing factors were identified by analyzing the sample collection and detection processes. Results: Among the 10 650 blood samples from the participants, 799 were HIV-positive in initial screening, in which 198 samples (24.78%) missed during confirmation test. Only 621 samples were received by the laboratory. After excluding misreported samples, 520 samples were qualified for testing. A total of 155 samples were eventually determined as recent infection through LAg-Avidity EIA; Based on the estimation formula , the incidence of HIV-1 infection in MSM in 20 cities was 4.06% (95%CI:3.27%-4.85%), it increased to 5.53% (95%CI: 4.45%-6.60%)after the adjusting for sample missing rate. When the sample missing rate and misreporting rate were both adjusted, the incidence of HIV-1 infection in the MSM increased to 5.66% (95%CI:4.67%-6.65%). The actual incidence of HIV-1 infection in MSM in the 20 cities might be between 4.06% and 5.66%. Conclusions: Sample missing and misreporting might cause the deviation of the estimation of HIV-1 infection incidence. It is important to ensure the sample source and the quality of sample collection and detection to reduce the deviation in the estimation of HIV-1 infection incidence.
Cross-Sectional Studies ; HIV Infections/epidemiology* ; HIV-1 ; Homosexuality, Male ; Humans ; Immunoenzyme Techniques ; Incidence ; Male ; Sexual and Gender Minorities

Purpose: This study investigated the value of synchronous tele-ultrasonography (TUS) for naive operators in thyroid ultrasonography (US) examinations. Methods: Ninety-seven patients were included in this prospective, parallel-controlled trial. Thyroid scanning and diagnosis were completed by resident A independently, resident B with guidance from a US expert through synchronous TUS, and an on-site US expert. The on-site expert’s findings constituted the reference standard. Two other off-site US experts analyzed all data in a blind manner. Inter-operator consistency between the two residents and the on-site US expert for thyroid size measurements, nodule measurements, nodule features, American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) categories, and image quality was compared. Two questionnaires were completed to evaluate the clinical benefit. Results: Resident B detected more nodules consistent with the on-site expert than resident A did (89.4% vs. 56.5%, P<0.001). Resident B achieved excellent consistency with the on-site expert in terms of ACR TI-RADS categories, nodule composition, shape, echogenic foci, and vascularity (all intra-class correlation coefficients [ICCs] >0.75), while resident A achieved lower consistency in ACR TI-RADS categories, composition, echogenicity, margin, echogenic foci, and vascularity (all ICCs 0.40-0.75). Residents A and B had excellent consistency in target nodule measurements (all ICCs >0.75). Resident B achieved better performance than resident A for gray values, time gain compensation, depth, color Doppler adjustment, and the visibility of key information (all P<0.05). Furthermore, 61.9% (60/97) of patients accepted synchronous TUS, and 59.8% (58/97) patients were willing to pay for it. Conclusion Synchronous TUS can help inexperienced residents achieve comparable thyroid diagnostic capability to a US expert.

Accurate methods for identifying pelvic lymph node metastasis (LNM) of prostate cancer (PCa) prior to surgery are still lacking. We aimed to investigate the predictive value of peripheral monocyte count (PMC) for LNM of PCa in this study. Two hundred and ninety-eight patients from three centers were divided into a training set (n = 125) and a validation set (n = 173). In the training set, the independent predictors of LNM were analyzed using univariate and multivariate logistic regression analyses, and the optimal cutoff value was calculated by the receiver operating characteristic (ROC) curve. The sensitivity and specificity of the optimal cutoff were authenticated in the validation cohort. Finally, a nomogram based on the PMC was constructed for predicting LNM. Multivariate analyses of the training cohort demonstrated that clinical T stage, preoperative Gleason score, and PMC were independent risk factors for LNM. The subsequent ROC analysis showed that the optimal cutoff value of PMC for diagnosing LNM was 0.405 × 109 l

OBJECTIVE: The clinical symptoms of diarrhea-predominant irritable bowel syndrome (IBS-D) can be effectively improved by traditional Chinese medicine (TCM) treatment, based on the usage of specific therapies for different TCM syndromes. However, in the stage of diagnosis, the standard criteria for the classification of TCM syndrome were still deficient. Through serum metabolic profiling, this study aimed to explore potential biomarkers in IBS-D patients with different TCM syndromes, which can assist in diagnosis of the disease. METHODS: Serum samples were collected from healthy controls (30 cases), IBS-D patients with Liver-Stagnation and Spleen-Deficiency syndrome (LSSD, 30 cases), Yang Deficiency of Spleen and Kidney syndrome (YDSK, 11 cases) and Damp Abundance due to Spleen-Deficiency syndrome (DASD, 22 cases). Serum metabolic profiling was conducted by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The potential biomarkers were screened by orthogonal partial least square-discriminate analysis, while metabolic pathways undergoing alterations were identified by pathway enrichment analysis in MetaboAnalyst 4.0. RESULTS: Overall, 34 potential biomarkers were identified in LSSD group, 36 in YDSK group and 31 in DASD group. And the 13 metabolites shared by three groups were determined as the potential biomarkers of IBS-D. Glycerophospholipid metabolism was disturbed significantly in IBS-D patients, which may play a role in IBS-D through inflammation. What's more, three TCM syndromes have the specific potential biomarkers in glycerophospholipid metabolism. CONCLUSION The serum metabolomics revealed that different TCM syndrome types in IBS-D may have different metabolic patterns during disease progression and glycerophospholipid metabolism was one of the pathways, whose metabolism was disturbed differently among three TCM syndromes in IBS-D. Therefore, the specific potential biomarkers in glycerophospholipid metabolism of three TCM syndromes in IBS-D can serve as the objective indicators, which can facilitate the TCM-syndrome objective classification of IBS-D.

Humans ; Magnetic Resonance Imaging ; Severity of Illness Index ; Spondylarthritis/diagnostic imaging* ; Whole Body Imaging

BACKGROUND: Carbapenemase-producing Klebsiella pneumoniae (CP-Kp) poses distinct clinical challenges due to extensively drug resistant (XDR) phenotype, and sequence type (ST) 11 is the most dominant blaKPC-2-bearing CP-Kp clone in China. The purpose of this current retrospective study was to explore the genetic factors associated with the success of XDR CP-Kp ST11 strains circulated in the intensive care unit (ICU) of a Chinese tertiary hospital. METHODS: Six ST11 XDR CP-Kp strains were identified between May and December 2014 and validated by minimum inhibitory concentration examination, polymerase chain reaction, and pyrosequencing. The six ST11 XDR CP-Kp, as well as three multi-drug resistant (MDR) and four susceptible strains, were sequenced using single-molecule real-time method. Comprehensively structural and functional analysis based on comparative genomics was performed to identify genomic characteristics of the XDR ST11 CP-Kp strains. RESULTS: We found that ST11 XDR blaKPC-2-bearing CP-Kp strains isolated from inpatients spread in the ICU of the hospital. Functionally, genes associated with information storage and processing of the ST11 XDR CP-Kp strains were more abundant than those of MDR and susceptible strains, especially genes correlative with mobile genetic elements (MGEs) such as transposons and prophages. Structurally, eleven large-scale genetic regions taken for the unique genome in these ST11 XDR CP-Kp strains were identified as MGEs including transposons, integrons, prophages, genomic islands, and integrative and conjugative elements. Three of them were located on plasmids and eight on chromosomes; five of them were with antimicrobial resistance genes and eight with adaptation associated genes. Notably, a new blaKPC-2-bearing ΔΔTn1721-blaKPC-2 transposon, probably transposed and truncated from ΔTn1721-blaKPC-2 by IS903D and ISKpn8, was identified in all six ST11 XDR CP-Kp strains. CONCLUSION Our findings suggested that together with clonal spread, MGEs identified uniquely in the ST11 XDR CP-Kp strains might contribute to their formidable adaptability, which facilitated their widespread dissemination in hospital.
Anti-Bacterial Agents ; Bacterial Proteins ; China ; Electrophoresis, Gel, Pulsed-Field ; Hospitals ; Humans ; Klebsiella Infections/drug therapy* ; Klebsiella pneumoniae/genetics* ; Microbial Sensitivity Tests ; Multilocus Sequence Typing ; Pharmaceutical Preparations ; Retrospective Studies ; beta-Lactamases/genetics*