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.

ObjectiveRepetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, offers a non-pharmacological therapeutic option for the management of Alzheimer’s disease (AD). Studies have demonstrated that ferroptosis plays a pivotal role in the pathological onset and progression of AD, and the inhibition of neuronal ferroptosis can significantly ameliorate cognitive impairments associated with AD. The imbalance of calcium ion (Ca²⁺) homeostasis is intimately associated with the pathology of AD and serves as a catalyst for the induction of ferroptosis through various pathways. This study is designed to investigate whether rTMS can ameliorate AD by inhibiting neuronal ferroptosis or maintaining calcium homeostasis, ultimately establishing a theoretical and experimental framework for the utilization of rTMS in AD treatment. MethodsAPP/PS1 AD mice were subjected to both 0.5 Hz low-frequency and 20 Hz high-frequency rTMS treatments, and the efficacy of these treatments was evaluated using novel object recognition and Morris water maze tests. ELISA was employed to quantify the levels of glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), Fe²⁺ within the hippocampi of mice from each group. HT-22 cells were induced to undergo ferroptosis via Erastin treatment, and subsequent to high- and low-frequency magnetic stimulation, cell viability was assessed using CCK-8 assay, while intracellular calcium ion concentration fluctuations were monitored using Fluo-4 AM. ResultsThe findings revealed that, when compared to normal mice, AD mice displayed a notable decline in cognitive function, accompanied by a substantial increase in ferroptosis levels and intracellular calcium ion concentrations. Both high-frequency and low-frequency applications of rTMS were found to significantly ameliorate cognitive impairments in AD mice, while also effectively mitigating the abnormal augmentation of neuronal ferroptosis and intracellular calcium ion levels. ConclusionThe present study underscores that both high-frequency and low-frequency rTMS exhibit efficacy in alleviating cognitive dysfunction in AD mice, potentially through the modulation of ferroptosis and intracellular calcium ion homeostasis.

This study aims to investigate the effect of salvianolic acid B (Sal B), the active ingredient of Salvia miltiorrhiza, on H9C2 cardiomyocytes injured by oxygen and glucose deprivation/reperfusion (OGD/R) through regulating mitochondrial fission and fusion. The process of myocardial ischemia-reperfusion injury was simulated by establishing OGD/R model. The cell proliferation and cytotoxicity detection kit (cell counting kit-8, CCK-8) was used to detect cell viability; the kit method was used to detect intracellular reactive oxygen species (ROS), total glutathione (t-GSH), nitric oxide (NO) content, protein expression levels of mitochondrial fission and fusion, apoptosis-related detection by Western blot. Mitochondrial permeability transition pore (MPTP) detection kit and Hoechst 33342 fluorescence was used to observe the opening level of MPTP, and molecular docking technology was used to determine the molecular target of Sal B. The results showed that relative to control group, OGD/R injury reduced cell viability, increased the content of ROS, decreased the content of t-GSH and NO. Furthermore, OGD/R injury increased the protein expression levels of dynamin-related protein 1 (Drp1), mitofusions 2 (Mfn2), Bcl-2 associated X protein (Bax) and cysteinyl aspartate specific proteinase 3 (caspase 3), and decreased the protein expression levels of Mfn1, increased MPTP opening level. Compared with the OGD/R group, it was observed that Sal B had a protective effect at concentrations ranging from 6.25 to 100 μmol·L^-1. Sal B decreased the content of ROS, increased the content of t-GSH and NO, and Western blot showed that Sal B decreased the protein expression levels of Drp1, Mfn2, Bax and caspase 3, increased the protein expression level of Mfn1, and decreased the opening level of MPTP. In summary, Sal B may inhibit the opening of MPTP, reduce cell apoptosis and reduce OGD/R damage in H9C2 cells by regulating the balance of oxidation and anti-oxidation, mitochondrial fission and fusion, thereby providing a scientific basis for the use of Sal B in the treatment of myocardial ischemia reperfusion injury.

Objective To analyze the cognition level of health care workers(HCWs)and the management status of various levels of medical institutions towards allergy reactions to commonly used antimicrobial agents.Methods HCWs and clinical pharmacists who were related to the diagnosis and treatment of antimicrobial agents in 14 medical institutions of city-level and autonomous prefectures in Gansu Province were randomly selected for a questionnaire survey.The survey contents included respondents'basic information,criteria for judging antimicrobial allergy,awareness on procedures related to antimicrobial allergy,and antimicrobial management level of different levels of medical institutions.Results A total of 8 670 valid questionnaires from HCWs were collected,including 3 300 phy-sicians,5 024 nurses and 328 pharmacists.160,775,2 123 and 5 612 HCWs were with senior,associate,interme-diate and junior professional titles,respectively.87.66％of the HCWs received relevant training on antimicrobial management in the past two years,the proportion of HCWs from different levels of medical institutions who have received training on antimicrobial management in the past two years was statistically significant different(x2=42.668,P＜0.001).HCWs with senior professional titles had the highest proportion of receiving relevant training(93.75％),there was a statistically significant difference in the proportion of receiving antimicrobial management training among HCWs with different professional titles in the past two years(x2=69.782,P＜0.001).50.98％of HCWs were not clear about penicillin allergy,and most of whom were with junior professional titles,accounting for 68.52％.25.19％of HCWs expressed uncertainty about whether patients with penicillin allergy could use cephalosporins,225 of whom were with associate professional titles,accounting for 29.03％of the total number of HCWs with associate profe-ssional titles.6.11％of HCWs had no experience in skin test procedure;46.94％of HCWs expressed that their medical institutions had no or unclear about whether their medical institutions had an antimicrobial allergy assess-ment team.Conclusion HCWs'judgment on allergy reactions to commonly used antimicrobial agents and aware-ness on antimicrobial application is not high enough,and the overall management level of antimicrobial allergy in all levels of medical institutions is poor.The popularity of antimicrobial allergy assessment teams is not high,and there is an urgent need to strengthen supervision,management,training,et al.

ObjectiveThe absorption of substances into blood is mainly dependent on the mesenteric lymphatic pathway and the portal venous pathway. The substances transported via the portal venous pathway can be metabolized by the biotransformation in the liver. On the contrary, the substances in the mesenteric lymph fluid enter the blood circulation without biotransformation and can affect the body directly. Alcohol consumption is strongly linked to global health risk. Previous reports have analyzed the changes of metabolites in plasma, serum, urine, liver and feces after alcohol consumption. Whether alcohol consumption affects the metabolites in lymph fluid is still unknown. Therefore, it is particularly important to explore the changes of substances transported via the mesenteric lymphatic pathway and analyze their harmfulness after alcohol drinking. MethodsIn this study, male Wistar rats were divided into high, medium, and low-dosage alcohol groups (receiving Chinese Baijiu at 56%, 28% and 5.6% ABV, respectively) and water groups. The experiment was conducted by alcohol gavage lasting 10 d, 10 ml·kg^-1·d^-1. Then mesenteric lymph fluid was collected for non-targeted metabolomic analysis by using liquid chromatography-mass spectrometry (LC-MS) and bioinformatic analysis. Principal component analysis and hierarchical clustering were performed by using Biodeep. Meanwhile, KEGG enrichment analysis of the differential metabolites was also performed by Biodeep. MetaboAnalyst was used to analyze the relationship between the differential metabolites and diseases. ResultsThe metabolites in the mesenteric lymph fluid of the high-dosage alcohol group change the most. Based on the KEGG enrichment analysis, the pathways of differential metabolites between the high-dosage alcohol group and the control group are mainly enriched in the central carbon metabolism in cancer, bile secretion, linoleic acid metabolism, biosynthesis of unsaturated fatty acids, etc. Interestingly, in the biosynthesis of unsaturated fatty acids category, the content of arachidonic acid is increased by 7.25 times, whereas the contents of palmitic acid, oleic acid, stearic acid, arachidic acid and erucic acid all decrease, indicating lipid substances in lymph fluid are absorbed selectively after alcohol intake. It’s worth noting that arachidonic acid is closely related to inflammatory response. Furthermore, the differential metabolites are mainly related with schizophrenia, Alzheimer’s disease and lung cancer. The differential metabolites between the medium-dosage alcohol and the control group were mainly enriched in phenylalanine metabolism, valine, leucine and isoleucine biosynthesis, linoleic acid metabolism and cholesterol metabolism. The differential metabolites are mainly related to schizophrenia, Alzheimer’s disease, lung cancer and Parkinson’s disease. As the dose of alcohol increases, the contents of some metabolites in lymph fluid increase, including cholesterol, L-leucine, fumaric acid and mannitol, and the number of metabolites related to schizophrenia also tends to increase, indicatingthat some metabolites absorbed by the intestine-lymphatic pathway are dose-dependent on alcohol intake. ConclusionAfter alcohol intake, the metabolites transported via the intestinal-lymphatic pathway are significantly changed, especially in the high-dosage group. Some metabolites absorbed via the intestinal-lymphatic pathway are dose-dependent on alcohol intake. Most importantly, alcohol intake may cause inflammatory response and the occurrence of neurological diseases, psychiatric diseases and cancer diseases. High-dosage drinking may aggravate or accelerate the occurrence of related diseases. These results provide new insights into the pathogenesis of alcohol-related diseases based on the intestinal-lymphatic pathway.

Objective To investigate the impact of emodin(EM)on vascular endothelial cell injury in rats with diabetes macroangiopathy by regulating hypoxia inducible factor-1α(HIF-1α)/vascular endothelial growth factor(VEGF)signaling pathway.Methods SD rats were divided into blank group and modeling group,the rats in the modeling group were fed with high fat and high sugar combined with N-nitro-L-arginine methyl ester to build the diabetes macroangiopathy model,and the blank group was fed with ordinary diet.The vascular endothelial cells successfully isolated from the thoracic aorta of rats in blank group and modeling group were named control group and model group,respectively.The vascular endothelial cells in the modeling group were divided into model group,dimethyloxallyl glycine(DMOG)group(10 μmol·L-1DMOG),combined group(80 mg·L-1EM+10 μmol·L-1 DMOG)and experimental-L,-M,-H groups(20,40,80 mg·L-1 EM).The apoptosis of rat vascular endothelial cells was detected by flow cytometry;Western blot was applied to detect the expression of HIF-1αand VEGF proteins in rat vascular endothelial cells.Results The apoptosis rates of vascular endothelial cells in experimental-M,-H groups,DMOG group,combined group,model group and control group were(10.18±0.36)％,(6.28±0.20)％,(24.96±1.18)％,(12.36±0.49)％,(18.76±0.68)％and(4.59±0.26)％;HIF-1α protein levels were 0.96±0.07,0.78±0.06,2.03±0.12,1.05±0.13,1.58±0.12 and 0.69±0.05;VEGF protein levels were 0.59±0.05,0.23±0.02,0.98±0.06,0.63±0.04,0.86±0.07 and 0.11±0.01.The above indexes in the model group were compared with the control,DMOG,experimental-M and experimental-H groups,and the above indexes in the combined group were compared with the experimental-H group,and the differences were statistically significant(all P＜0.05).Conclusion EM may inhibit HIF-1α/VEGF pathway to improve vascular endothelial cell injury in rats with diabetes macroangiopathy.

Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannan-binding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP. Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays. Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05). Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.

Objective To explore characteristics of clinical parameters and cytokines in patients with drug-induced liver injury(DILI)caused by different drugs and their correlation with clinical indicators. Method The study was conducted on patients who were up to Review of Uncertainties in Confidence Assessment for Medical Tests(RUCAM)scoring criteria and clinically diagnosed with DILI.Based on Chinese herbal medicine,cardiovascular drugs,non-steroidal anti-inflammatory drugs(NSAIDs),anti-infective drugs,and other drugs,patients were divided into five groups.Cytokines were measured by Luminex technology.Baseline characteristics of clinical biochemical indicators and cytokines in DILI patients and their correlation were analyzed. Results 73 patients were enrolled.Age among five groups was statistically different(P=0.032).Alanine aminotransferase(ALT)(P=0.033)and aspartate aminotransferase(AST)(P=0.007)in NSAIDs group were higher than those in chinese herbal medicine group.Interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-α)in patients with Chinese herbal medicine(IL-6:P<0.001;TNF-α:P<0.001)and cardiovascular medicine(IL-6:P=0.020;TNF-α:P=0.001)were lower than those in NSAIDs group.There was a positive correlation between ALT(r=0.697,P=0.025),AST(r=0.721,P=0.019),and IL-6 in NSAIDs group. Conclusion Older age may be more prone to DILI.Patients with NSAIDs have more severe liver damage in early stages of DILI,TNF-α and IL-6 may partake the inflammatory process of DILI.

Objective To design a novel oxygenator to solve the existing problems of extracorporeal membrane oxygenation(ECMO)machine in high transmembrane pressure difference,low efficiency of blood oxygen exchange and susceptibility to thrombosis.Methods The main body of the oxygenator vascular access flow field was gifted with a flat cylindrical shape.The topology of the vascular access was modeled in three dimensions,and the whole flow field was cut into a blood inlet section,an inlet buffer,a heat exchange zone,a blood oxygen exchange zone,an outlet buffer and a blood outlet section.The oxygenator was compared with Quadrox oxygenator by means of ANSYS FLUENT-based simulation and prototype experiments.Results Simulation calculations showed the oxygenator designed was comparable to the clinically used ones in general,and gained advantages in transmembrane pressure difference,blood oxygen exchange and flow uniformity.Experimental results indicated that the oxygenator behaved better than Quadrox oxygenator in transmembrane pressure difference and blood oxygen exchange.Conclusion The oxygenator has advantages in transmem-brane pressure difference,temperature change,blood oxygen ex-change and low probability of thrombosis.[Chinese Medical Equipment Journal,2024,45(3):23-28]

Objective To investigate disease characteristics and hospitalization costs of children with Mycoplasma Pneumoniae pneumonia(MPP)admitted to Shanghai municipal medical hospitals from 2019 to 2023.Methods Depending on the Shanghai Municipal Hospital Pediatric Alliance,we retrospectively investigated community acquired MPP pediatric patients hospitalized in 22 municipal hospitals with pediatric qualifications(including 4 children's hospitals)in Shanghai from Jan 2019 to Dec 2023.We collected the patients'diagnosis codes,gender,age,length of hospital stay,hospitalization costs,and whether they progressed to severe Mycoplasma pneumoniae pneumonia(SMPP).Results From 2019 to 2023,a total of 29 045 hospitalized children with MPP were treated,with 6 035 cases(20.8%)identified as SMPP in the 22 hospitals.Trend analysis revealed a rising trend with years in the proportion of SMPP patients(χ2trend=365.498,P<0.001).Among the 4 children's hospitals,there were 18 710 cases with MPP,including 4 078 cases(21.8%)of SMPP.The proportion of SMPP patients also showed an increasing trend with years(χ2trend=14.548,P<0.001),and the proportion in 2023(23.0%)was higher than that in previous years with statistical significance.There were statistical differences in the seasonal distribution of MPP cases between different years,with higher proportions in summer and autumn overall.The age distribution of hospitalized MPP children varied among different years,with school-age children accounting for the majority(56.8%)in 2023.There was no difference in the distribution of severe cases between different genders,but there were differences in the proportion of severe cases among different age groups in different years,with a gradual increase in severe cases among children aged 1 to 3 years(χ2trend=191.567,P<0.001).The average length of hospital stay for MPP during the epidemic was higher than that during non-epidemic periods,and there were statistically significant differences in the average length of hospital stay between different years(P<0.001).The individual hospitalization costs during the epidemic were higher than in other years,and there were statistically significant differences in individual hospitalization costs between different years(P<0.001).The total hospitalization costs were still higher in 2019 and 2023.The individual hospitalization costs for SMPP were higher than for non-SMPP cases.Conclusion MPP outbreaks occurred in Shanghai in 2019 and 2023,with the higher proportions in summer and autumn overall.Compared to previous years,the number of hospitalized MPP children in Shanghai was higher in 2023,with a higher proportion of SMPP cases,especially among children under 3 years old.The individual per capita hospitalization expenses for SMPP cases were higher than for non-SMPP cases.