The influence of gut microbiota on membranous nephropathy: A two-sample Mendelian randomization study.

BACKGROUND: Therapeutic approaches that target the gut microbiota may be helpful in the potential prevention and treatment of membranous nephropathy (MN). Several studies demonstrated a correlation between gut microbiota and MN. However, the confounding evidence cannot prove a causal relationship between gut microbiota and MN. MATERIALS AND METHODS: The aim of our study is to assess genome-wide association study data for a causal relationship between gut microbiota and MN using a two-sample Mendelian randomization (MR) approach. Inverse variance weighted (IVW) was used as the primary technique to determine the association of genetic variants from gut microbiota and MN patients. Besides, sensitivity analyses confirmed the accuracy of the results. Finally, we applied false discovery rate (FDR) correction to results with IVW < 0.05 during multiple hypothesis testing. RESULTS: The results from IVW estimates indicated that Bacillales exhibited a significant association with MN, acting as a risk factor (OR = 1.52, 95% CI: 1.14 - 2.02, p = 0.005). In addition, our univariable MR results showed that 7 bacterial taxa (Melainabacteria, Butyricicoccus, Catenibacterium, Ruminiclostridium5, RuminococcaceaeUCG003, RuminococcaceaeUCG013, and Gastranaerophilales) had suggestive associations with MN. The sensitivity analysis did not reveal any significant heterogeneity in the instrumental variables or horizontal pleiotropy. CONCLUSION: Our findings provided causal evidence for the effect of gut microbiota on MN patients and broadened the spectrum of bacterial taxa that might be involved in the pathogenesis of MN. These selected bacterial taxa hold promise as new biomarkers, which may aid in designing targeted therapeutic modalities for MN, improving our comprehension of the gut-kidney axis.

Immunomodulation in Endometriosis: Investigating the interrelationship between VISTA expression and Escherichia.Shigella-Associated metabolites.

AIMS: Endometriosis is characterized by an abnormal immune microenvironment. Despite the extensive use of immune therapies, the application of immune checkpoint inhibitors in endometriosis lacks confidence due to the instability of preclinical research data. This study aims to elucidate the regulation of the immune inhibitory checkpoint VISTA and its effects on T cells from the perspective of microbiota and metabolism. MAIN METHODS: We divided endometriosis patients into high and low groups based on the expression levels of VISTA in lesion tissues. We collected peritoneal fluid samples from these two groups and performed 16 s RNA sequencing and metabolomics analysis to investigate microbial diversity and differential metabolites. Through combined analysis, we identified microbial-associated metabolites and validated their correlation with VISTA and CD8 + T cells using ELISA and immunofluorescence. In vitro experiments were conducted to confirm the regulatory relationship among these factors. KEY FINDINGS: Our findings revealed a distinct correlation between VISTA expression and the microbial colony Escherichia.Shigella. Moreover, we identified the metabolites LTD4-d5 and 2-n-Propylthiazolidine-4-carboxylic acid as being associated with both Escherichia.Shigella and VISTA expression. In vitro experiments confirmed the inhibitory effects of these metabolites on VISTA expression, while they demonstrated a positive regulation of CD8 + T cell infiltration into endometriotic lesions. SIGNIFICANCE: This study reveals the connection between microbial diversity, metabolites, and VISTA expression in the immune microenvironment of endometriosis, providing potential targets for therapeutic interventions.

Mining key circadian biomarkers for major depressive disorder by integrating bioinformatics and machine learning.

OBJECTIVE: This study aimed to identify key clock genes closely associated with major depressive disorder (MDD) using bioinformatics and machine learning approaches. METHODS: Gene expression data of 128 MDD patients and 64 healthy controls from blood samples were obtained. Differentially expressed were identified and weighted gene co-expression network analysis (WGCNA) was first performed to screen MDD-related key genes. These genes were then intersected with 1475 known circadian rhythm genes to identify circadian rhythm genes associated with MDD. Finally, multiple machine learning algorithms were applied for further selection, to determine the most critical 4 circadian rhythm biomarkers. RESULTS: Four key circadian rhythm genes (ABCC2, APP, HK2 and RORA) were identified that could effectively distinguish MDD samples from controls. These genes were significantly enriched in circadian pathways and showed strong correlations with immune cell infiltration. Drug target prediction suggested that small molecules like melatonin and escitalopram may target these circadian rhythm proteins. CONCLUSION: This study revealed discovered 4 key circadian rhythm genes closely associated with MDD, which may serve as diagnostic biomarkers and therapeutic targets. The findings highlight the important roles of circadian disruptions in the pathogenesis of MDD, providing new insights for precision diagnosis and targeted treatment of MDD.

Comparison of microbial abundance and diversity in uterine and peritoneal fluid in infertile patients with or without endometriosis.

INTRODUCTION: Endometriosis (EM) is a multifactorial disease that affects 10 - 15% of women of reproductive age. Additionally, 30-50% of women with EM suffer from infertility. The mechanism of infertility caused by EM has not yet been consistently explained. In recent years, studies have shown a link between infertility associated with EM and changes in the reproductive tract microbiota. METHODS: In this study, we involved 26 EM patients (8 cases of stage I-II and 18 cases of stage III-IV) and 31 control subjects who were tubal obstruction-related infertility (TORI). The samples from peritoneal fluid (PF) and uterine fluid (UF) were collected and sequenced by 16 S rRNA amplicon. RESULTS: In the comparison of microbial diversity, we found no significant differences in the microbial diversity of PF and UF between patients with stage I-II EM and those with TORI. However, there was a significant difference in microbial diversity among patients with stage III-IV EM compared to the previous two groups. Lactobacillus decreased in PF of EM compared to the control group, while it increased in UF. In PF, the abundance of Pseudomonas, Enterococcus, Dubosiella and Klebsiella was significantly higher in patients with stage III-IV compared to TORI patients. And in UF, the main differences existed between stage I-II EM compared to the other two groups. The abundance of pontibacter, aquabacterium, Rikenellaceae and so on at the genus level was significantly enriched in the EM patients with stage I-II. In the analysis based on KEGG database, EM may affect the receptivity related pathways of the endometrium by influencing changes in the uterine microbiota. CONCLUSION: Our results indicated that as EM progresses, the microorganisms in UF and PF keep changing. These changes in the microbiota, as well as the resulting alternations in gene functional classification, may play an important role in the infertility associated with EM.

Disrupted Tuzzerella abundance and impaired L-glutamine levels induce Treg accumulation in ovarian endometriosis: a comprehensive multi-omics analysis.

INTRODUCTION: The microbial community plays a crucial role in the pathological microenvironment. However, the structure of the microbial community within endometriotic lesions and its impact on the microenvironment is still limited. METHODS: All 55 tissue samples, including ovarian ectopic (OEMs) and normal (NE) endometrium, were subjected to 16S rRNA sequencing, metabolomic and proteomic analysis. RESULTS: We found the abundance of Tuzzerella is significantly lower in OEMs compared to NE tissue (p < 0.01). We selected samples from these two groups that exhibited the most pronounced difference in Tuzzerella abundance for further metabolomic and proteomic analysis. Our findings indicated that endometriotic lesions were associated with a decrease in L-Glutamine levels. However, proteomic analysis revealed a significant upregulation of proteins related to the complement pathway, including C3, C7, C1S, CLU, and A2M. Subsequent metabolic and protein correlation predictions demonstrated a negative regulation between L-Glutamine and C7. In vitro experiments further confirmed that high concentrations of Glutamine significantly inhibit C7 protein expression. Additionally, immune cell infiltration analysis, multiplex immunofluorescence, and multifactorial testing demonstrated a positive correlation between C7 expression and the infiltration of regulatory T cells (Tregs) in ectopic lesions, while L-Glutamine was found to negatively regulate the expression of chemotactic factors for Tregs. CONCLUSION: In this study, we found a clear multi-omics pathway alteration, "Tuzzerella (microbe)-L-Glutamine (metabolite)-C7 (protein)," which affects the infiltration of Tregs in endometriotic lesions. Our findings provide insights into endometriosis classification and personalized treatment strategies based on microbial structures.

Based on Serum Pharmacochemistry and Virtual Screening Technique Analysis Used to Explore the Potential Active Ingredients and Possible Anti- Coronary Heart Disease Mechanisms of Salvia miltiorrhiza Bunge.

AIMS AND OBJECTIVE: This study aimed to identify the bioactive compounds and explore the multi-target mechanisms of Salvia miltiorrhiza Bunge (SMB) against coronary heart disease (CHD) using an integrated serum pharmacochemistry and network pharmacology approach. MATERIALS AND METHODS: The chemical constituents of SMB were characterized by UPLC-MS. The absorbed ingredients and metabolites after oral SMB administration were identified in rat serum. Therapeutic targets of SMB against CHD were predicted by intersecting the targets of absorbed compounds from databases and CHD-associated genes. Protein-protein interaction network, pathway analysis, molecular docking, and molecular dynamic simulation were performed. RESULTS: A total of 61 SMB-derived compounds were identified in rat serum. Network analysis revealed 111 candidate targets highly related to CHD pathways. Further topological analysis identified 10 hub targets and 20 key active compounds, constructing an informative compoundtarget- pathway network. PTGS2 and TNF were predicted as primary targets of SMB against CHD based on molecular dynamic simulation. CONCLUSION: This integrated approach identified bioactive compounds and multi-target mechanisms of SMB against CHD. The results provide scientific evidence supporting SMB's clinical efficacy and reveal potential anti-CHD targets.

TMT-based quantitative proteomics analysis of the effects of Jiawei Danshen decoction myocardial ischemia-reperfusion injury.

BACKGROUND: Every year, approximately 17 million people worldwide die due to coronary heart disease, with China ranking second in terms of the death toll. Myocardial ischemia-reperfusion injury (MIRI) significantly influences cardiac function and prognosis in cardiac surgery patients. Jiawei Danshen Decoction (JWDSD) is a traditional Chinese herbal prescription that has been used clinically for many years in China to treat MIRI. The underlying molecular mechanisms, however, remain unknown. To investigate the proteomic changes in myocardial tissue of rats given JWDSD for MIRI therapy-based proteomics. METHODS: MIRI rat model was created by ligating/releasing the left anterior descending coronary artery. For seven days, the drugs were administered twice daily. The model was created following the last drug administration. JWDSD's efficacy in improving MIRI was evaluated using biochemical markers and cardiac histology. Tandem mass tag-based quantitative proteomics (TMT) technology was also used to detect proteins in the extracted heart tissue. To analyze differentially expressed proteins (DEPs), bioinformatics analysis, including gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathways, were employed. Furthermore, western blotting confirmed the potential targets regulated by JWDSD. RESULTS: The histopathologic characteristics and biochemical data showed JWDSD's protective effects on MIRI rats. A total of 4549 proteins were identified with FDR (false discovery rate) ≤1%. Twenty overlapping were identified (162 DEPs and 45 DEPs in Model/Control or JWDSD/Model group, respectively). Of these DEPs, 16 were regulated by JWDSD. GO analysis provided a summary of the deregulated protein expression in the categories of biological process (BP), cell component (CC), and molecular function (MF). KEGG enrichment analysis revealed that the signaling pathways of neutrophil extracellular trap formation, RNA polymerase, serotonergic synapse, and linoleic acid metabolism are all closely related to JWDSD effects in MIRI rats. Furthermore, T-cell lymphoma invasion and metastasis 1 (TIAM1) was validated using western blotting, and the results were consistent with proteomics data. CONCLUSIONS: Our study suggests that JWDSD may exert therapeutic effects through multi-pathways regulation in MIRI treatment. This work may provide proteomics clues for continuing research on JWDSD in treating MIRI.

SFRP4+IGFBP5hi NKT cells induced neural-like cell differentiation to contribute to adenomyosis pain.

Background: Adenomyosis is an estrogen-dependent gynecological disease. The pathogenesis of chronic pain, the main clinical symptom of adenomyosis, remains undefined. As a combination lymphocyte with both T-cell and natural killer (NK)-cell properties, NK T (NKT) cells play a role in immune defense against numerous diseases and modulate cell differentiation. Method: This study analyzed the tissue-cell samples from adenomyosis with or without pain by single-cell sequencing. Result: We found a specific population of secreted frizzled-related protein 4 (SFRP4)+NKT cells and a large amount of undifferentiated multipotent stem cells in the adenomyosis pain group. We discovered that a high expression of IGFBP5 in SFRP4+NKT cells could promote the differentiation of multipotent stem cells into neural-like cells via the single-cell trajectory. Through verification by the sample, we found that the degree of the expression of the neuronal marker NEFM was correlated with the duration of pain in adenomyosis patients. The expression of IGFBP5 was positively correlated with the pain scores of adenomyosis patients. Conclusion: Collectively, these findings suggest that SFRP4+IGFBP5hi NKT cells were capable of converting part of the stem cells into neurogenic cells and inducing adenomyosis pain.

Application of a Knowledge, Attitude, Belief, and Practice Model in Pain Management of Patients with Acute Traumatic Fractures and Alcohol Dependence.

Objective: To evaluate the outcome of a knowledge, attitude, belief, and practice mode (KABP) in the pain management in patients with acute traumatic fractures complicated with alcohol dependence. Methods: Twenty-nine alcohol-dependent male patients with acute traumatic fractures and who received surgical treatment between January 2019 and December 2020 were included in this retrospective case-control study. The age range was 30-65 years (average 50.03 ± 7.94). Fracture Type. Six cases of spinal burst fractures and 23 cases of limb trauma fractures. Ten patients were treated with routine nursing (control group), and 19 patients were treated with pain management in KABP mode (experimental group). The control group received traditional pain care, including the conventional numerical rating scale (NRS) pain score system, with focus on symptomatic treatment. On this basis, the experimental group managed pain using KABP, including cognitive behavioral intervention, optimization programs, modification of personal beliefs, and behavior patterns. NRS, self-rated anxiety/depression scale (SAS), and quality of life (SF-36) scale were applied at admission, 1 day before surgery, and 3 months after surgery. Results: The perioperative NRS score of the KABP group was lower than that of the control group, and the postoperative anxiety levels improved. Discharge satisfaction was significantly higher than that in the control group (p < 0.05). There were behaviors promoting health in the experimental group, and five patients expressed abstinence behavior after discharge (p < 0.05). Conclusion: Patients with alcohol dependence represents a unique set of cases for perioperative pain management. To ensure patient safety, individualized pain management through the application of KABP can significantly reduce postoperative pain and promote the generation of healthy behaviors in patients.

Simulation Study on Coil of Biomass Carbonization Kettle.

The damage and failure of coiling tube in biomass carbonization kettle due to the long-term operation was discussed. According to the actual structure of the carbonization kettle, a three-dimensional model was established, and the temperature field was simulated based on the given design parameters. The results show that the temperature distribution is stable during 440~450 °C, and the relative error with the actual temperature 449.2 °C, which is about 0.78%. The tensile specimens made of 20G steel, the common material of the coil, was placed in a tubular furnace, and the real heat treatment conditions were simulated with mixed gas and water vapor. After that, the uniaxial tensile test was carried out on MTS testing machine. The obtained physical parameters such as yield strength and elastic modulus were substituted into the numerical temperature field model to obtain the stress field model. The simulation results indicate that during the initial ventilation of the equipment, the coil compressed with the maximum stress of 8.3 MPa at the bending point of the second and fourth laps and partial failure was prone to occur, which is consistent with the actual coil failure result.

A Simulation Analysis of Maternal Pelvic Floor Muscle.

Pelvic floor disorder (PFD) is a common disease affecting the quality of life of middle-aged and elderly women. Pelvic floor muscle (PFM) damage is related to delivery mode, fetal size, and parity. Spontaneous vaginal delivery causes especially great damage to PFM. The purpose of this study was to summarize the characteristics of PFM action during the second stage of labor by collecting female pelvic MRI (magnetic resonance imaging) data and, further, to try to investigate the potential pathogenetic mechanism of PFD. A three-dimensional model was established to study the influence factors and characteristics of PFM strength. In the second stage of labor, the mechanical responses, possible damage, and the key parts of postpartum lesions of PFM due to the different fetal biparietal diameter (BPD) sizes were analyzed by finite element simulations. The research results showed that the peak stress and strain of PFM appeared at one-half of the delivery period and at the attachment point of the pubococcygeus to the skeleton. In addition, during the simulation process, the pubococcygeus was stretched by about 1.2 times and the levator ani muscle was stretched by more than two-fold. There was also greater stress and strain in the middle area of the levator ani muscle and pubococcygeus. According to the statistics, either being too young or in old maternal age will increase the probability of postpartum PFM injury. During delivery, the entire PFM underwent the huge deformation, in which the levator ani muscle and the pubococcygeus were seriously stretched and the attachment point between the pubococcygeus and the skeleton were the places with the highest probability of postpartum lesions.

Long-term trends in the incidence of endometriosis in China from 1990 to 2019: a joinpoint and age-period-cohort analysis.

BACKGROUND: Trends in the incidence of endometriosis in China remain unknown. The purpose of this study was to examine the trends in the incidence of endometriosis and the effects of age, period, and cohort on them. METHODS: Trends in endometriosis incidence were estimated using joinpoint regression. Age-period-cohort analysis was used to analyze the effects of age, period, and cohort on these trends. Endometriosis incidences in China (1990-2019) were retrieved from the Global Burden of Disease Study 2019. Annual percentage change and average annual percent change (AAPC) were analyzed by joinpoint regression, and relative risks were analyzed using an age-period-cohort model. RESULTS: Age-standardized incidence rates (ASIRs) declined between 1990 and 2019 in China, with an overall AAPC of -1.2% (95% CI: -1.20, -1.10). Compared to 1990, the ASIR in 2019 decreased by almost 30%. Moreover, the joinpoint regression analysis revealed that endometriosis ASIRs showed a downward trend across all age groups. A significant age-related effect was seen for endometriosis incidence among young women aged 15-24 years, which then decreased with advancing age. Consistently, the effect of the period on endometriosis incidence showed a declining trend, and the effect of birth cohort decreased by 0.53 (42.7%) from 1938-1942 to 1998-2002. CONCLUSIONS: Endometriosis ASIRs declined from 1990 to 2019. The effects of period and birth cohort on endometriosis incidence exhibited a declining trend across all age groups. The effect of age on endometriosis incidence showed an increasing trend before the age of 24, followed by a decreasing trend with subsequent advancing age.

Efficacy of PD-1/PD-L1 inhibitors in ovarian cancer: a single-arm meta-analysis.

Several studies have evaluated the efficacy of PD-1/PD-L1 inhibitors in ovarian cancer; however, the response rate varies. This study aims to explore the efficacy of anti-PD-1/PD-L1 therapy in ovarian cancer. A quantitative meta-analysis was performed through a systematic search in PubMed, Web of Science, and the Cochrane Library. The pooled ORR was calculated and compared. Fifteen trials were included in this meta-analysis. Our analyses showed that the pooled ORR of all included studies was 19% (95% CI: 13%, 27%). Single PD-1/PD-L1 inhibitors had the lowest ORR of 9% (95% CI: 7%, 12%), while the combination of PD-1/PD-L1 inhibitors and chemotherapy had the highest ORR of 36% (95% CI: 24%, 51%). This study showed that PD-1/PD-L1 inhibitors alone have limited efficacy for ovarian cancer. The combination of PD-1/PD-L1 inhibitors and chemotherapy could be chosen as the recommended modality for further study.

[Recent advances in microchip liquid chromatography].

Miniaturization is an important trend in modern analytical instrument development, including miniaturized gas chromatography and liquid chromatography, as well as micro bore columns and capillary-to-microfluidics-based platforms. Apart from the miniaturization of the separation column, which is the core part of a chromatographic system, other parts of the system, including the sampler, pumping system, gradient generation, and detection systems, have been miniaturized. Miniaturized liquid chromatography significantly reduces solvent and sample consumption while providing comparable or even better separation efficiency. When liquid chromatography is coupled with mass spectroscopy, a low flow rate can increase the ionization efficiency, leading to enhanced sensitivity of the mass spectrometer. In contrast, normal-scale liquid chromatography suffers from its relatively high volumetric flow rate, which challenges the scanning frequency of the mass spectrometer. On the other hand because of the small sample size, other detection strategies such as spectrometric methods cannot provide sufficient sensitivity and limits of detection. In this sense, mass spectrometry has become the detection method of choice for micro-scale liquid-phase chromatography. Miniaturized liquid chromatography can diminish sample dilution efficiently when extremely small amounts of samples are used. The main driving force for this miniaturization trend, especially in liquid-phase separations, is the desperate need for microscale analyses of biological and clinical samples, given these samples are precious and the sample size is usually very small. At present, microscale liquid-phase chromatography is the only method of choice for such small, precious, and highly informative samples. The miniaturization of liquid chromatography systems, especially chromatographic columns, would be advantageous to the modularization and integration of liquid chromatography instrumental systems. Chip liquid chromatography is an integration of chromatography columns, liquid control systems, and detection methods on a single microfluidic chip. Chip liquid chromatography is an excellent format for the miniaturization of liquid chromatography systems, and it has already attracted significant attention from academia and industry. However, this attempt is challenging, and great effort is required on fundamental techniques, such as the substrate material of the microfluidic chip, structure of the micro-chromatography column, fluid control method, and detection methods, in order to make the chips suitable for liquid chromatography. Currently, the major problem in chip liquid chromatography is that the properties of the chip substrate materials cannot meet the requirements for further miniaturization and integration of chip liquid chromatography. The strength of the existing chip substrate materials is generally below 60 MPa, and the material properties limit further advances in the miniaturization and integration of chromatographic chips. Therefore, new chip substrate materials and the standard of chip channel design such as channel size and channel structure should be the key for further development of chip liquid chromatography. Mainstream instrumentation companies as well as new start-up innovation companies are now undertaking efforts toward the development of microchip liquid chromatographic products. Agilent, the first instrumentation company that introduced commercial microchip liquid chromatographic columns to the market, has led this field. Apart from microchip-based columns, Agilent introduced trap columns for different kinds of biological molecules as well as gradient generation systems for microchip-based liquid phase chromatography. Recently, another start-up company introduced microchip columns based on the in situ microfabrication of the column bed rather than packing the column with a particulate material. Such developments in microfabrication may further propel the advancement of micro-scale liquid-phase chromatography to an unprecedented level, which is beyond the conventional components and materials employed in normal-scale liquid chromatography. This review introduces the recent research progress in microchip liquid chromatography technologies, and briefly discusses the current state of commercialization of microchips for liquid chromatography by major instrumentation companies.

Alamandine protects against renal ischaemia-reperfusion injury in rats via inhibiting oxidative stress.

OBJECTIVE: This study was to determine whether alamandine (Ala) could reduce ischaemia and reperfusion (I/R) injury of kidney in rats. METHODS: Renal I/R was induced by an occlusion of bilateral renal arteries for 70 min and a 24-h reperfusion in vivo, and rat kidney proximal tubular epithelial cells NRK52E were exposed to 24 h of hypoxia and followed by 3-h reoxygenation (H/R) in vitro. RESULTS: The elevated serum creatinine (Cr), blood cystatin C (CysC) and blood urea nitrogen (BUN) levels in I/R rats were inhibited by Ala treatment. Tumour necrosis factor alpha (TNF)-α, IL-1ß, IL-6, cleaved caspase-3, cleaved caspase-8 and Bax were increased, and Bcl2 was reduced in the kidney of I/R rats, which were reversed by Ala administration. Ala reversed the increase of TNF-α, IL-1ß, IL-6, cleaved caspase-3, cleaved caspase-8 and Bax and the decrease of Bcl2 in the H/R NRK52E cells. Ala could also inhibit the increase of oxidative stress levels in the kidney of I/R rats. NADPH oxidase 1 (Nox1) overexpression reversed the improving effects of Ala on renal function, inflammation and apoptosis of I/R rats. CONCLUSION: These results indicated that Ala could improve renal function, attenuate inflammation and apoptosis in the kidney of I/R rats via inhibiting oxidative stress.

Segmented Microfluidics-Based Packing Technology for Chromatographic Columns.

Nanoflow liquid chromatography-mass spectrometry (NanoLC-MS) has become the method of choice for the analysis of complex biological systems, especially when the available sample amount is limited. The preparation of high-performance capillary columns for nanoLC use is still a technical challenge. Here, we report a segmented microfluidic method for the preparation of packed capillary columns, where liquid segments were used as soft, dynamic, and well-dispersed slurry reservoirs for carrying and delivering micrometer packing particles. Based on this microfluidic packing technology, the column bed was assembled layer-by-layer at a 50 µm resolution, and ultralong capillary columns of 3, 5, and 10 m were fabricated in such a manner. The microfluidically packed columns demonstrated excellent separation efficiencies of 116 000 plates/m. The higher efficiencies obtained at higher slurry concentrations also indicate that a high-quality packed bed can be obtained without sacrificing the packing speed. Kinetic performance limit analysis shows that the microfluidic packed columns have higher peak capacity production efficiency in the high-resolution region, presenting an improved separation impedance of 2800, which is significantly better than columns packed with the conventional slurry packing method. In comparison with a commercial nanoLC column, a 5 m long microfluidic packed column was evaluated for proteomic analysis using a standard HeLa protein digest and presented 261% improvement in peptide identification capability, resulting in significantly enhanced protein identification confidence.

Dose-related histopathology and bone remodeling characteristics of the knee articular cartilage and subchondral bone induced by glucocorticoids in rats.

The aim of the current study was to investigate histopathological changes and bone remodeling in the knee articular cartilage and subchondral bone in rats following treatment with glucocorticoids. A total of 30 3-month-old female Sprague-Dawley rats were randomly divided into either a vehicle control group or one of three experimental groups wherein dexamethasone (Dex) was administered at a dose of 1.0, 2.5 or 5.0 mg/kg (Dex1.0, Dex2.5 and Dex5.0, respectively), for 8 weeks. Articular cartilage and the epiphyseal subchondral bone of the proximal tibias were evaluated by histopathology or for bone remodeling using histomorphometry. No histological changes were identified in the knee articular cartilage but the bone formation rate of the subchondral bone was lower in the Dex1.0 group compared with that of the control group. Compared with the control and the Dex1.0 group, the width of the articular cartilage and the subchondral plate were larger, with abnormal morphology and increased apoptosis of chondrocytes, decreased cell/matrix volume ratio in the cartilage and fewer blood vessels in the subchondral plate in the Dex2.5 and Dex5.0 groups. A higher Dex dose resulted in more severe inhibition of bone formation, a greater number of apoptotic osteocytes and constrained bone resorption. All microstructure parameters indicated no significant changes in the Dex2.5 group but exhibited deterioration in the Dex5.0 group compared with the normal and Dex1.0 group. There were no significant differences in morphological changes, or in static and dynamic bone indices between the Dex2.5 and Dex5.0 groups. In conclusion, long-term glucocorticoid use induced dose-related histopathological changes in the knee articular cartilage, along with unbalanced bone remodeling and osteopenia in the subchondral bone. The degree of damage to the articular cartilage was milder and transformed from compensation to degeneration at higher doses.

Towards a high peak capacity of 130 using nanoflow hydrophilic interaction liquid chromatography.

Hydrophilic interaction liquid chromatography, HILIC, is a relatively new HPLC mode. Compared with other HPLC modes, HILIC is a high resolution chromatographic mode with high peak capacity for separations of complex mixtures. Although the separation mechanism is still not completely clear, HILIC has been widely used for analysis of hydrophilic compounds which are difficult for reversed phase chromatography to retain and separate. In this study, we fabricated and investigated nanoHILIC columns in terms of separation efficiency, van Deemter curves and more importantly, we focused on long packed capillary columns, and studied their extreme resolution for protein digests. Using meter long nanoHILIC columns packed with 5 µm particles, we realized a high peak capacity of 130. Based on nanoLC-MS, we compared the resolution and protein identification capabilities of nanoHILIC and nanoRPLC. The results indicate both nanoHILIC and nanoRPLC can provide high resolution for protein sequencing but neither mode is significantly better than the other. Among the 99 digest peptides identified, 17 were uniquely identified by nanoHILIC-MS and 20 were uniquely identified by nanoRPLC-MS and 62 were identified by both methods. Although at this moment in time, nanoRPLC is the most popular microseparation tool in proteomics, the excellent complementarity of nanoHILIC and nanoRPLC suggests their combined use in achieving deep-coverage in MS-based proteomics.

[Recent advances in hyphenation of nanoflow liquid phase separation with inductively coupled plasma mass spectrometry].

High-performance nanoflow liquid-phase separation techniques such as nanoflow liquid chromatography (nanoLC), capillary electrophoresis (CE), and microchip chromatography and electrophoresis (chip-ICP-MS) have been hyphenated with inductively coupled plasma mass spectrometry (ICP-MS) extensively. This hyphenation combines the excellent characteristics of the front-end separation technology, such as high selectivity, sensitivity, and speed, and low sample consumption, and the advantages of back-end ICP-MS, such as high resolution, wide dynamic range, and absolute quantification capability. Thus, such hyphenation is becoming an increasingly important analytical tool. Herein we systematically introduce the recent development of hyphenated nanoLC, CE, and chip-ICP-MS, review its application in chemical and biochemical analysis, and discuss potential future developments of hyphenating these technologies.