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.

The outer membrane composed predominantly of lipopolysaccharide (LPS) is an essential biological barrier for most Gram-negative (G^-) bacteria. Lipopolysaccharide transport protein (Lpt) complex LptDE is responsible for the critical final stage of LPS transport and outer membrane assembly. The structure and function of LptDE are highly conserved in most G^- bacteria but absent in mammalian cells, and thus LptDE complex is regarded as an attractive antibacterial target. In recent 10 years, the deciphering of the three-dimensional structure of LptDE protein facilities the drug discovery based on such "non-enzyme" proteins. Murepavadin, a peptidomimetic compound, was reported to be the first compound able to target LptD, enlightening a new class of antibacterial molecules with novel mechanisms of action. This article is devoted to summarize the molecular characteristics, structure-function of LptDE protein complex and review the development of murepavadin and related peptidomimetic compounds, in order to provide references for relevant researches.

Objective To observe the clinical efficacy of joint needling method combined with ultrasound in the treatment of qi stagnation and blood stasis type of patellofemoral pain syndrome(PFPS).Methods Eighty-six patients with qi stagnation and blood stasis type of PFPS were randomly divided into observation group and control group,with 43 cases in each group.The control group was given western medicine conventional treatment combined with functional exercise,and the observation group was given joint needling method combined with ultrasound treatment on the basis of the control group.Both groups were treated for 2 consecutive weeks.After 2 weeks of treatment,the clinical efficacy of the two groups was evaluated,and the changes in the Visual Analogue Scale(VAS)scores of knee pain and the Kujala scale scores of the two groups were observed before and after treatment.The changes in active range of motion(AROM)of the affected knee joint were compared before and after treatment between the two groups.Results(1)After treatment,the VAS scores of the two groups of patients were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving the level of VAS scores,and the difference was statistically significant(P＜0.05).(2)After treatment,the Kujala scores of patients in the two groups were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving the level of Kujala scores,and the difference was statistically significant(P＜0.05).(3)After treatment,the AROM of patients in the two groups were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving the level of AROM,and the difference was statistically significant(P＜0.05).(4)The total effective rate was 95.35%(41/43)in the observation group and 81.40%(35/43)in the control group.The efficacy of the observation group was superior to that of the control group,and the difference was statistically significant(P＜0.05).Conclusion The joint needling method combined with ultrasound can significantly relieve the pain symptoms of patients with PFPS and promote the recovery of knee joint function,and the clinical efficacy is remarkable.

BACKGROUND:After the internal fixation of cannulated screws in femoral neck fractures,because the affected limb is often unable to bear weight in the short term and the implants with high stiffness have a stress shielding effect on the fracture end,it is easy to cause osteoporosis of the affected limb and changes in the biomechanical distribution of the proximal femur,the incidence of osteonecrosis of the femoral head is high after surgery.At present,few studies have been conducted on the biomechanical effects of osteoporosis at the proximal end of the femur occurring after femoral neck fracture surgery on femoral neck fracture treated with cannulated screws. OBJECTIVE:Using finite element analysis,to investigate the biomechanical effects of osteoporosis occurring after femoral neck fracture surgery on femoral neck fracture treated with cannulated screws and explore the role of biomechanical factors in osteonecrosis of the femoral head. METHODS:Based on the obtained CT scan data of the femur in a patient with a femoral neck fracture,a proximal femoral model for internal fixation for femoral neck fracture was established by Mimics 19.0,3-Matic,UG 11.0,Hypermesh 14.0,and Abaqus software.One finite element model of the proximal femur without osteoporosis and three finite element models of the proximal femur with osteoporosis were analyzed using Abaqus software.The stress,contact pressure,displacement peak and cloud map under different components of the four models were measured and analyzed,and the internal stress changes and distribution of the femoral head were compared and analyzed. RESULTS AND CONCLUSION:The stresses and contact pressures of the femoral head and lower anterior cannulated screws varied more with the degree of osteoporosis.The peak displacement of the four models increased slowly with the degree of osteoporosis.By one-way analysis of variance,there was no significant effect of the degree of osteoporosis on the peak stress,contact pressure,and displacement of the different components.The internal stress distribution of the femoral head changed with the degree of osteoporosis.Changes in the biomechanical environment of the proximal femur have an important impact on osteonecrosis of the femoral head.

Objective:To analyze the external quality control assessment results of salt iodine, urine iodine, and water iodine in iodine deficiency disorders (IDD) laboratories at all levels in Shandong Province, and provide reliable quality assurance for monitoring and prevention of IDD.Methods:The external quality control assessment of salt iodine, urine iodine and water iodine in provincial, municipal and county levels IDD laboratories in Shandong Province from 2017 to 2021 were conducted, and feedback rate and qualification rate were calculated.Results:From 2017 to 2021, the feedback rates and qualification rates of external quality control assessment of salt iodine, urine iodine and water iodine at provincial and municipal levels IDD laboratories in Shandong Province were all 100.0%. The feedback rates of county level laboratories participating in the salt iodine external quality control assessment were all 100.0%. The qualification rate in 2021 was 99.3% (135/136), and the other four years were all 100.0%. The feedback rates of county level laboratories participating in the urine iodine external quality control assessment were all 100.0%. The qualification rates in 2017 and 2021 were 98.4% (122/124) and 97.1% (132/136), respectively, and the other three years were all 100.0%. In 2021, the county level laboratories in Shandong Province participated in the water iodine external quality control assessment for the first year, and the feedback rate and qualification rate of 69 laboratories were both 100.0%.Conclusion:From 2017 to 2021, the detection capacity of IDD laboratories at the provincial and municipal levels in Shandong Province remains at a high level, and the detection capacity of salt iodine and urine iodine in some county level laboratories still needs to be further improved.

Objective:To investigate the current situation of the use of transjugular intrahepatic portosystemic shunt (TIPS) for portal hypertension, which should aid the development of TIPS in China.Methods:The China Portal Hypertension Alliance (CHESS) initiated this study that comprehensively investigated the basic situation of TIPS for portal hypertension in China through network research. The survey included the following: the number of surgical cases, main indications, the development of Early-TIPS, TIPS for portal vein cavernous transformation, collateral circulation embolization, intraoperative portal pressure gradient measurement, commonly used stent types, conventional anticoagulation and time, postoperative follow-up, obstacles, and the application of domestic instruments.Results:According to the survey, a total of 13 527 TIPS operations were carried out in 545 hospitals participating in the survey in 2021, and 94.1% of the hospital had the habit of routine follow-up after TIPS. Most hospitals believed that the main indications of TIPS were the control of acute bleeding (42.6%) and the prevention of rebleeding (40.7%). 48.1% of the teams carried out early or priority TIPS, 53.0% of the teams carried out TIPS for the cavernous transformation of the portal vein, and 81.0% chose routine embolization of collateral circulation during operation. Most of them used coils and biological glue as embolic materials, and 78.5% of the team routinely performed intraoperative portal pressure gradient measurements. In selecting TIPS stents, 57.1% of the hospitals woulel choose Viator-specific stents, 57.2% woulel choose conventional anticoagulation after TIPS, and the duration of anticoagulation was between 3-6 months (55.4%). The limitation of TIPS surgery was mainly due to cost (72.3%) and insufficient understanding of doctors in related departments (77.4%). Most teams accepted the domestic instruments used in TIPS (92.7%).Conclusions:This survey shows that TIPS treatment is an essential part of treating portal hypertension in China. The total number of TIPS cases is far from that of patients with portal hypertension. In the future, it is still necessary to popularize TIPS technology and further standardize surgical indications, routine operations, and instrument application.

OBJECTIVE To confirm the therapeutic effect of Jintiange capsules on osteoarthritis(OA) and the potential mechanism of synovial mesenchymal stem cell exosomes(SMSC-Exos) and articular chondrocytes(ACs) in the treatment of OA based on high-throughput sequencing technology. METHODS Type Ⅱ collagenase-induced OA rats were used for efficacy verification through general behavioral observation, bipedal balance difference experiment, mechanical foot reflex threshold, Micro-CT observation, and Safranin O-Fast Green staining. SMSCs and ACs were cultured in suitable concentration of drug-containing serum, and mRNA sequencing was performed on ACs in the control, model, and Jintiange capsules groups, as well as miRNA sequencing on SMSC-Exos. Differential expressed mRNAs and miRNAs were screened and target genes were predicted. The common differential expressed genes between SMSC and ACs were obtained by intersecting the differential expressed genes, and a miRNA-mRNA regulatory network was constructed using Cytoscape software. The expression trend analysis of common differential expressed genes was conducted, as well as the correlation analysis between differential expressed gene mRNA and miRNA, Micro-CT efficacy indicators, and differential expressed gene mRNA. RESULTS Under the pathological state of OA, the expression of miRNA-23a-3p, miRNA-342-3p, miRNA-146b-5p, miRNA-501-3p, and miRNA-214-3p were down-regulated, while miRNA-222-3p, miRNA-30e-3p, miRNA-676-3p, and miRNA-192-5p were up-regulated (P<0.05). The expressions of these miRNAs were significantly reversed after intervention with drug-containing serum of Jintiange capsules. There was a certain correlation between Micro-CT efficacy indicators, mRNA and miRNA. CONCLUSION Jintiange capsule has obvious efficacy in the treatment of OA, and its mechanism may be related to the promotion of SMSC-Exos targeting ACs to transport miRNA and then regulate Serpinb10, Ntn1, Il1b, Tgm2, Megf10, Il11, Cd40, Slc15a3, Pou2f2 and other genes.

Objective To compare the effects of 20 mg qd and 10 mg bidadministration of iprrazole enteric-coated tablets on the control of gastric acid in healthy subjects.Methods A randomized,single-center,parallel controlled trial was designed to include 8 healthy subjects.Randomly divided into 2 groups,20 mg qd administration group:20 mg enteric-coated tablets of iprrazole in the morning;10 mg bid administration group:10 mg enteric-coated tablets of iprrazole in the morning and 10 mg in the evening.The pH values in the stomach of the subjects before and 24 h after administration were monitored by pH meter.The plasma concentration of iprazole after administration was determined by HPLC-MS/MS.The main pharmacokinetic parameters were calculated by Phoenix WinNonlin(V8.0)software.Results The PK parameters of iprrazole enteric-coated tablets and reference preparations in fasting group were as follows:The Cmax of 20 mg qd group and 10 mg bid group were(595.75±131.15)and(283.50±96.98)ng·mL-1;AUC0-t were(5 531.94±784.35)and(4 686.67±898.23)h·ng·mL-1;AUC0-∞ were(6 003.19±538.59)and(7 361.48±1 816.77)h·ng·mL-1,respectively.The mean time percentage of gastric pH＞3 after 20 mg qd and 10 mg bid were 82.64％and 61.92％,and the median gastric pH within 24 h were 6.25±1.49 and 3.53±2.05,respectively.The mean gastric pH values within 24 h were 5.71±1.36 and 4.23±1.45,respectively.The correlation analysis of pharmacokinetic/pharmacodynamics showed that there was no significant correlation between the peak concentration of drug in plasma and the inhibitory effect of acid.Conclusion Compared with the 20 mg qd group and the 10 mg bid group,the acid inhibition effect is better,the administration times are less,and the safety of the two administration regimes is good.

OBJECTIVE To investigate the effects and mechanism of Yiqi huoxue decoction （YQHX） on lumbar disc herniation in rats. METHODS Rats were randomly divided into sham operation group， model group， NF-κB inhibitor group （QNZ group， 1 mg/kg）， YQHX group （9.1 g/kg） and combination group （YQHX+QNZ group， the same dose as each single drug group）， with 10 rats in each group. Except for sham operation group， lumbar disc herniation model of rats was induced in other groups； administration groups were given QNZ intraperitoneally or/and YQHX intragastrically， once a day， for 8 consecutive weeks. The severity of intervertebral disc herniation was evaluated in each group； the pathological changes of intervertebral discs and the changes of autophagy of nucleus pulposus cells were all observed； the level of tumor necrosis factor-α （TNF-α） in serum， and the ratios of Bcl-2/adenovirus E1B interacting protein 3 （BNIP3） and Beclin-1 positive cells in intervertebral disctissues were detected； the phosphorylation of nuclear factor-κB （NF-κB） p65， the expressions of tumor necrosis factor receptor- associated factor-2 （TRAF-2）， TRAF-3， BNIP3 and LC3B protein， and mRNA expressions of NF-κB p65， LC3B， p62，BNIP3 and Beclin-1 were determined. RESULTS Compared with model group， Pfirrmann grading score decreased significantly，the pathological injury of intervertebral disc tissue was relieved in YQHX group； the number of autophagosomes in nucleus pulposus cells increased； serum level of TNF-α and mRNA expression of p62 in intervertebral disc tissue decreased significantly； the ratios of BNIP3 and Beclin-1 positive cells， the phosphorylation of NF-κB p65， the expressions of TRAF-2， TRAF-3， BNIP3 and LC3B protein as well as the mRNA expressions of NF- κB p65， LC3B， BNIP3 and Beclin-1 decreased significantly in intervertebral disc tissues （P＜0.05）. The changes of above indexes in YQHX group were reversed partly in YQHX+QNZ group. CONCLUSIONS YQHX promotes the elevation of autophagy level of intervertebral discs， slows down the inflammatory response and the progression of lumbar disc herniation by activating the NF-κB signaling pathway.

A new alkaloid (1) and six known compounds (2-7) were isolated from the solid fermentation extract of the endophytic fungus Alternaria tenuissima Pas85 of Phragmites australis by silica gel column chromatography, Sephadex LH-20 column chromatography, high performance liquid chromatography and other chromatographic techniques. The structures of these compounds were determined by HREIMS, NMR, IR spectroscopy, and literature comparison, and the anti MRSA (methicillin-resistant Staphylococcus aureus) activity of 1-5 were tested. Compounds 1, 2, 3 and 4 exhibited certain inhibitory activity with MIC values of 64, 4, 32 and 32 μg·mL^-1, respectively, and compound 5 showed no significant inhibitory activity.