Socioeconomic deprivation, medical services accessibility, and income-related health inequality among older Chinese adults: evidence from a national longitudinal survey from 2011 to 2018.

BACKGROUND: Health inequality poses a challenge to improving the quality of life of older adults as well as the service system. The literature rarely explores the moderating role of medical services accessibility in the association between socioeconomic deprivation and health inequality. OBJECTIVE: This study examines the socioeconomic deprivation and medical services accessibility associated with health inequality among older Chinese adults, which will contribute to the medical policy reform. METHODS: Using data from the 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), we analyse 14,232 older adults. This paper uses a concentration index (CI) to measure the income-related health inequality among the target population and employs a recentered influence function-concentration index-ordinary least squares (RIF-CI-OLS) model to empirically analyse the correlation between socioeconomic deprivation and health inequality among older Chinese adults. Based on the correlation analysis, we discuss the moderating effect of medical services accessibility. RESULTS: We find that health inequality exists among older Chinese adults and that the relative deprivation in socioeconomic status (SES) is significantly associated with health inequality (ß∈  [0.1109,  0.1909], P < 0.01). The correlation between socioeconomic deprivation and health inequality is moderated by medical services accessibility, which means that an increase in medical services accessibility can weaken the correlation between socioeconomic deprivation and health inequality. CONCLUSION: China needs an in-depth reform of its medical services accessibility system to promote the equitable distribution of medical services resources, strengthen medical costs and quality management, and ultimately mitigate the SES reason for health inequality among older Chinese adults.

Higher cefazolin concentrations in synovial fluid with intraosseous regional prophylaxis in knee arthroplasty: a randomized controlled trial.

BACKGROUND: Prophylactic antibiotics reduce the risk of periprosthetic joint infection. However, conventional systemic administration may not provide adequate tissue concentrations against more resistant organisms such as coagulase-negative staphylococci. Intraosseous regional administration is known to achieve significantly higher antibiotic tissue concentrations than systemic administration, but it is unclear how synovial fluid concentrations are affected. We aimed to compare synovial fluid cefazolin concentrations achieved by regional intraosseous versus systemic intravenous administration, and also to compare synovial fluid cefazolin concentrations with those in subcutaneous fat. METHODS: A total of 60 patients undergoing primary knee arthroplasty were randomized into 2 groups: group IO received 2 g interosseous cefazolin in 100 mL saline through a tibial cannula after tourniquet inflation and before skin incision; group IV received 2 g cefazolin in 100 mL saline via the median basilic or median cephalic vein 30 min before tourniquet inflation. Subcutaneous fat and synovial fluid samples were collected immediately after skin incision, and cefazolin concentrations were measured by high-performance liquid chromatography. RESULTS: The cefazolin concentration in synovial fluid was 391.3 ± 70.1 µg/ml in group IO and 17.6 ± 3.5 µg/ml in group IV. The cefazolin concentration in subcutaneous fat was 247.9 ± 64.9 µg/g in group IO and 11.4 ± 1.9 µg/g in group IV. CONCLUSION: Intraosseous regional administration results in several times higher tissue concentrations than systemic administration, especially in the synovial fluid.

MS-based metabolite analysis of two licorice chalcones in mice plasma, bile, feces, and urine after oral administration.

Isoliquiritigenin (ILG) and isoliquiritin (ILQ), two kinds of major flavonoids in licorice, are biological active substances with antioxidant, anti-inflammatory, and tumor-suppressive effects. However, their in vivo metabolites, possible material basis of this two licorice chalcones for the treatment of diseases, have not been studied completely. To determine the metabolism of ILG and ILQ, after oral administration of 100 mg/kg/day of these compounds for consecutive 8 days, the metabolites of these two licorice chalcones in mice plasma, urine, feces, and bile were determined using liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry in this study. The structures of those metabolites were tentatively identified according to their fragment pathways, accurate masses, characteristic product ions, metabolism law, and reference standards-matching. As a result, a total of 25 and 29 metabolites of ILG and ILQ were identified, respectively. Seven main metabolic pathways, oxidation and reduction, deglycosylation and glycosylation, dehydroxylation and hydroxylation, demethoxylation and methoxylation, acetylation, glucuronidation, and sulfation, were summarized to tentatively explain how the metabolites were biologically transformed. These results provide the important information on the metabolism of ILG and ILQ, which may be helpful for the further research of their pharmacological mechanism.

Multiple pathophysiological roles of midkine in human disease.

Midkine (MK) is a low molecular-weight protein that was first identified as the product of a retinoic acid-responsive gene involved in embryonic development. Recent studies have indicated that MK levels are related to various diseases, including cardiovascular disease (CVD), renal disease and autoimmune disease. MK is a growth factor involved in multiple pathophysiological processes, such as inflammation, the repair of damaged tissues and cancer. The pathophysiological roles of MK are diverse. MK enhances the recruitment and migration of inflammatory cells upon inflammation directly and also through induction of chemokines, and contributes to tissue damage. In lung endothelial cells, oxidative stress increased the expression of MK, which induced angiotensin-converting enzyme (ACE) expression and the consequent conversion from Ang I to Ang II, leading to further oxidative stress. MK inhibited cholesterol efflux from macrophages by reducing ATP-binding cassette transporter A1 (ABCA1) expression, which is involved in lipid metabolism, suggesting that MK is an important positive factor involved in inflammation, oxidative stress and lipid metabolism. Furthermore, MK can regulate the expansion, differentiation and activation of T cells as well as B-cell survival; mediate angiogenic and antibacterial activity; and possess anti-apoptotic activity. In this paper, we summarize the pathophysiological roles of MK in human disease.

IgG Immunocomplexes Sensitize Human Monocytes for Inflammatory Hyperactivity via Transcriptomic and Epigenetic Reprogramming in Rheumatoid Arthritis.

Prevalence of circulating immunocomplexes (ICs) strongly correlates with rheumatoid arthritis (RA) in humans. Deposits of IgG-ICs are abundant in affected joints of patients, yet molecular mechanisms for the pathogenic roles of such ICs are not fully understood. In this study, we present evidence that IgG-ICs precipitated from RA sera sensitized human monocytes for a long-lasting inflammatory functional state, characterized by a strong TNF-α response to cellular proteins representing damage-associated molecular patterns and microbe-derived pathogen-associated molecular patterns. Importantly, plate-coated human IgG (a mimic of deposited IC without Ag restriction) exhibited a similarly robust ability of monocyte sensitization in vitro. The plate-coated human IgG-induced functional programming is accompanied by transcriptomic and epigenetic modification of various inflammatory cytokines and negative regulator genes. Moreover, macrophages freshly isolated from synovia of patients with RA, but not sera-negative arthropathy, displayed a signature gene expression profile highly similar to that of IC-sensitized human monocytes, indicative of historical priming events by IgG-ICs in vivo. Thus, the ability of IgG-ICs to drive sustainable functional sensitization/reprogramming of monocytes and macrophages toward inflammation may render them key players in the development of RA.

Disease-Specific Autoantibodies Induce Trained Immunity in RA Synovial Tissues and Its Gene Signature Correlates with the Response to Clinical Therapy.

Much evidence suggests that trained immunity is inappropriately activated in the synovial tissue in rheumatoid arthritis (RA), but the underlying mechanism remains unclear. Here, we describe how RA-specific autoantibody deposits can train human monocytes to exert the hyperactive inflammatory response, particularly via the exacerbated release of tumor necrosis factor α (TNFα). Comparative transcriptomic analysis by plate-bound human IgG (cIgG) or ß-glucan indicated that metabolic shift towards glycolysis is a crucial mechanism for trained immunity. Moreover, the cIgG-trained gene signatures were enriched in synovial tissues from patients with ACPA- (anticitrullinated protein antibody-) positive arthralgia and undifferentiated arthritis, and early RA and established RA bore a great resemblance to the myeloid pathotype, suggesting a historical priming event in vivo. Additionally, the expression of the cIgG-trained signatures is higher in the female, older, and ACPA-positive populations, with a predictive role in the clinical response to infliximab. We conclude that RA-specific autoantibodies can train monocytes in the inflamed lesion as early as the asymptomatic stage, which may not merely improve understanding of disease progression but may also suggest therapeutic and/or preventive strategies for autoimmune diseases.

Metabolic network and recovery mechanism of Escherichia coli associated with triclocarban stress.

Although the toxicity of triclocarban at molecular level has been investigated, the metabolic networks involved in regulating the stress processes are not clear. Whether the cells would maintain specific phenotypic characteristics after triclocarban stress is also needed to be clarified. In this study, Escherichia coli was selected as a model to elucidate the cellular metabolism response associated with triclocarban stress and the recovery metabolic network of the triclocarban-treated cells using the proteomics and metabolomics approaches. Results showed that triclocarban caused systematic metabolic remodeling. The adaptive pathways, glyoxylate shunt and acetate-switch were activated. These arrangements allowed cells to use more acetyl-CoA and to reduce carbon atom loss. The upregulation of NH3-dependent NAD+ synthetase complemented the NAD+ consumption by catabolism, maintaining the redox balance. The synthesis of 1-deoxy-D-xylulose-5-phosphate was suppressed, which would affect the accumulation of end products of its downstream pathway of isoprenoid synthesis. After recovery culture for 12 h, the state of cells returned to stability and the main impacts on metabolic network triggered by triclocarban have disappeared. However, drug resistance caused by long-term exposure to environmentally relevant concentration of triclocarban is still worthy of attention. The present study revealed the molecular events under triclocarban stress and clarified how triclocarban influence the metabolic networks.

Design, synthesis, and fungicidal evaluation of novel oxysterol binding protein inhibitors for combatting resistance associated with oxathiapiprolin.

Oxathiapiprolin, the first successful oxysterol binding protein (OSBP) inhibitor for oomycete control, is regarded as an important milestone in the history of fungicide discovery. However, its interaction with OSBP remain unclear. Moreover, some plant pathogenic oomycetes have developed medium to high resistance to oxathiapiprolin. In this paper, the three-dimensional (3D) structure of OSBP from Phytophthora capsici (pcOSBP) was built, and its interaction with oxathiapiprolin was systematically investigated by integrating molecular docking, molecular dynamics simulations, and molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) calculations. The computational results showed that oxathiapiprolin bound to pcOSBP forms H-bonds with Leu73, Lys74, Ser69, and water molecules. Then, based on its interaction with pcOSBP, oxathiapiprolin was structurally modified to discover new analogs with high fungicidal activity and a low risk of resistance. Fortunately, compound 1e was successfully designed and synthesized as the most potent candidate, and it showed a much lower resistance risk (RF < 1) against LP3-M and LP3-H in P. capsici. The present work indicated that the piperidinyl-thiazole-isoxazoline moiety is useful for further optimization. Furthermore, compound 1e could be used as a lead compound for the discovery of new OSBP inhibitors.

[Identification of four Armillaria strains and their effects on quality and yield of Gastrodia elata f. glauca].

In order to improve the quality and yield of Gastrodia elata f. glauca,determine the suitable Armillaria strains for the accompanying experiment in Xiaocaoba,Yiliang,four Armillaria strains were selected. They were used for G. elata cultivation,and the gene sequence,r DNA-ITS,ß-tubulin and EF1-α of four Armillaria strains,were compared and analyzed. The yield was mesured in November which was based on previous laboratory research. The tubers were washed and steamed,then dried and powdered. The content of gastrodin and p-hydroxybenzyl alcohol was determined by UPLC,the polysaccharide was determined by phenol-concentrated sulfuric acid method. The results showed that the strains M1,M2,M3 and M4 were Armillaria gallica group but there were differences in the yield and active ingredient content when they were cultivated with the same G. elata. The yield of G. elata( Jian Ma) was the lowest when cultivated with Armillaria strain M3,but it was not the same when used M1,0. 981 kg·m-2,the highest yield in the four stains.The content of gastrodin was 0. 581%,the total content of gastrodin and p-hydroxybenzyl alcohol was 0. 595%,when accompanied with M1 strains. It was higher than other strains. The content of G. elata polysaccharide was 2. 132%,which was similar to the content of M3 strain,higher than that of M2 and M4 strain. Selecting phylogenesis of Armillaria strians,the content of active ingredient,and the yield as indicators,it was concluded concerned that the M1 strain was the best of four strains. The results will provide a theoretical basis and guidance for higher yield and quality in cultivation of G. elata in Yiliang.

MicroRNA-21 suppresses ox-LDL-induced human aortic endothelial cells injuries in atherosclerosis through enhancement of autophagic flux: Involvement in promotion of lysosomal function.

Atherosclerosis is a common pathological basis of cardiovascular disease and remains the leading cause of mortality. Endothelial cell (EC) injury and autophagy dysfunction have been proved to contribute to the development of atherosclerosis. Recently, accumulating evidence confirms that microRNAs (miRNAs) have emerged as vital regulators and fine-tuners of various pathophysiological cellular impacts and molecular signaling pathways involved in atherosclerosis. Herein, the objective of the present study was to explore the biological function of miR-21 in oxidized low-density lipoprotein (ox-LDL)-induced human aortic endothelial cells (HAECs) injury and the underlying molecular mechanism. The results showed that ox-LDL treatment significantly decreased HAECs viability, increased caspase-3 activity, apoptosis ratio and Bax protein expression, and reduced Bcl-2 protein expression resulting in EC injuries. Simultaneously, ox-LDL treatment obviously reduced miR-21 level in a time-and dose-dependent manner. Notably, ox-LDL-induced EC injuries were abolished by miR-21 mimics transfection. In addition, miR-21 mimics alleviated ox-LDL-induced impaired autophagic flux as illustrated by the increases in LC3-II/LC3-I ratio and Beclin-1 protein expression, and the decrease in p62 protein expression in HAECs. Moreover, ox-LDL suppressed the expressions of lysosomal membrane protein (LAMP1) and cathepsin D proteins, and attenuated cathepsin D activity in HAECs, leading to lysosomal dysfunction, while these effects were also blocked by miR-21 mimics. These findings indicated that miR-21 restored impaired autophagic flux and lysosomal dysfunction, thereby attenuating ox-LDL-induced HAECs injuries.

Micro RNA-19a suppresses IL-10 in peripheral B cells from patients with atherosclerosis.

BACKGROUND AND AIMS: The interleukin (IL)-10-production B cells play an important role in the pathogenesis of atherosclerosis (Asro) with unknown mechanism. Micro RNA (miR)-17-92 cluster has strong immune regulatory activities. This study tests a hypothesis that miR-17-92 cluster suppresses IL-10 expression in B cells of Asro patients. METHODS: Patients with Asro were recruited into this study. Peripheral blood samples were collected from the patients. B cells were isolated from the blood samples and analyzed to elucidate the role of miR-17-92 in the regulation of IL-10 expression. RESULTS: Peripheral B cells from patients with Asro show lower levels of IL-10 than that from healthy subjects. The IL-10 expression in the B cells is negatively correlated with the expression of miR-19a in the B cells. The serum levels of tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-4 in Asro patients were higher than healthy subjects. Exposure to TNF-α or IFN-γ or IL-4 suppressed IL-10 expression in B cells via increasing the expression of miR-19a in B cells, which could be abolished by Inhibition of miR-19a. CONCLUSIONS: TNF-α or IFN-γ or IL-4 suppresses IL-10 in B cells via up regulating miR-19a expression.

Aneuploid progenies of triploid hybrids between diploid and tetraploid loach Misgurnus anguillicaudatus in China.

Triploid Chinese loach, Misgurnus anguillicaudatus, hybrids between tetraploids from Hubei Province and diploids from Liaoning Province were mated with either diploid wild-type or triploid hybrids to analyze viability and ploidy of the resultant progenies. Both triploid males and females generated fertile gametes, but progenies from the crosses using gametes of triploid hybrids did not survive beyond the larval stages. In crosses between wild-type diploid females and triploid hybrid males, embryos ranging from 2.2n to 2.6n were predominant with a mode of either 2.4n (chromosome numbers 59, 60, 61) or 2.5n (chromosome numbers 62, 63). Those from the crosses between triploid hybrid females and diploid males gave a modal ploidy level at approximately 2.5n in one case, but a shift to a higher ploidy level was observed in other embryos. In the progenies between triploid hybrid females and males, the ploidy level at approximately 3.0n (chromosome numbers 74, 75, 76) was most frequent. The cytogenetic results of the progenies suggest the production of aneuploid gametes with a modal ploidy level at approximately 1.5n in triploid hybrids. However, a shift to higher chromosome numbers in gametes was observed in certain cases, suggesting the involvement of mortality selection of gametes and/or zygotes with lower chromosome numbers.

Expression, purification, and breast cancer cell inhibiting effect of recombinant human lactoferrin C-lobe.

Lactoferrin (LTF), a multifunctional glycoprotein of the transferrin family mainly found in exotic secretions in mammals, is an important defense molecule against not only microbial invasion but also tumors. It folds into two globular domains (N- and C-lobes) each containing an iron-binding site. The cationic antimicrobial peptide in N-lobe is known to exert anti-tumor effect via a non-receptor-mediated pathway. However, whether LTF C-lobe also contributes to its anti-tumor activity remains to be investigated. In this study, a human LTF fragment (amino acid residues 343-682) covering the C-lobe was expressed with a histidine tag in E. coli and the purified polypeptide refolded through a series of buffer changing procedure. The resultant recombinant protein caused significant growth arrest of breast carcinoma cells MDA-MB-231 in a dose- and time-dependent manner, evidently via induction of apoptosis of the cell. Our data suggest a positive role for the C-lobe of human LTF in controlling tumors in vitro.

[Distribution of Inflammatory Cells and Expression of PSGL-1 in Infant Brainstem Tissue Related Fatal Brainstem Encephalitis].

OBJECTIVE: To explore the distribution of inflammatory cells and positive expression of P-se- lectin glycoprotein ligand-1 (PSGL-1) in infant brainstem tissue from hand-foot-mouth disease related fatal brainstem encephalitis. METHODS: Twenty brainstem samples from infants suffered from brainstem en- cephalitis were collected as the experimental group. Ten brainstem samples from infants died of non- brain diseases and injuries were collected as the control group. The distribution of inflammatory cells and the expression of PSGL-1 in the two groups were examined by immunohistochemical method. The characteristics of the positive cells were observed. RESULTS: In brainstem tissue of the experimental group, there were sleeve infiltrations of inflammatory cells around the vessels and in the glial nodule. Microglia was the most and following was neutrophils around the vessels and in the glial nodule. There was a significant statistical difference among microglias, neutrophils and lymphocytes (P < 0.05). There was no sleeve infiltration in the control group. PSGL-1 protein was expressed widely in inflammatory cells in the experimental group, especially in the inflammatory cells around the vessels and in the glial nodule. But PSGL-1 positive staining could be observed significantly less in the control group comparing with the experimental group (P < 0.05). CONCLUSION: Microglia is the main type of inflammatory cells involved in the progress of the fatal disease. Moreover, PSGL-1 could participate in the pathogenesis of hand-foot-mouth disease related fatal brainstem encephalitis.

Simultaneous determination of 20 phthalate esters in oil-free food by UPLC/MS/MS.

A quantitative method was established for the determination of 20 phthalate esters (PAEs) in oil-free food by ultra-performance LC/MS/MS and was used to evaluate the PAEs of 111 oil-free samples from supermarkets in Hangzhou City. By quantification with the internal standard D4-bis(2-ethylexyl) phthalate, linearity ranges of the 20 PAEs were observed with correlation coefficients of 0.9990-0.9999. For liquid and solid sample, the spiking recoveries were 65.5-129.9% with RSD of 2.7-9.7% and 70.9-126.9% with RSD of 1.6-9.8% (n = 6), and the method LODs were 0.05-7.4 microg/L and 0.6-14.4 microg/kg, respectively. Most of the 111 oil-free samples had detectable PAEs; the detection rate was 23.0-42.0%, and the concentration of PAEs was in the range of 1.0-38 610.9 microg/kg. The detection rate in the drink packaged in a glass bottle was the highest, next was laver, and the detection rate in the drink packaged in a plastic bottle was the lowest.

Myopia control efficacy of peripheral defocus soft contact lenses in children and adolescents: A meta-analysis.

OBJECTIVES: To evaluate the effect of peripheral defocus soft contact lenses (PDSCLs) on controlling myopia progression in children and adolescents, and to compare it with orthokeratology (Ortho-K) and single vision lenses (SVLs). METHODS: We conducted a systematic search of PubMed, the Cochrane Library, Medline, CNKI, CBM, VIP, and WanFang Data databases for randomized controlled trials (RCTs) and cohort studies that investigated the effects of PDSCLs on myopia control in children and adolescents. The published languages were limited to English and Chinese. The risk bias tool provided by the Cochrane risk-of-bias tool and Newcastle-Ottawa Scale were used to assess the risk bias of included studies of RCTs and CTs. The published biases of included studies were assessed by Egger`s test. RESULTS: We included 21 studies, comprising 13 RCTs and 8 cohort studies, with a total of 1337 participants in the PDSCLs group, 428 in the Ortho-K group, and 707 in the SVLs group. The meta-analysis indicated no significant difference between PDSCLs and Ortho-K in controlling the increase of diopter (MD = 0.01, 95% CI: -0.06, 0.09; P = 0.69) and axial length (MD = -0.01, 95% CI: -0.02, 0.00; P = 0.28). Compared with SVLs, PDSCLs had a better effect in controlling the increase of diopter (MD = 0.23, 95% CI: 0.17, 0.28; P < 0.00001) and axial length (MD = -0.11, 95% CI: -0.12, -0.09; P < 0.00001) in children and adolescents. CONCLUSIONS: Children and adolescents wearing PDSCLs can achieve better myopia control than those wearing SVLs, and their effect is comparable to that of Ortho-K.

Immune checkpoint inhibitor-associated gastritis: Patterns and management.

Immune checkpoint inhibitors (ICIs) are widely used due to their effectiveness in treating various tumors. Immune-related adverse events (irAEs) are defined as adverse effects resulting from ICI treatment. Gastrointestinal irAEs are a common type of irAEs characterized by intestinal side effects, such as diarrhea and colitis, which may lead to the cessation of ICIs. Although irAE gastritis is rarely reported, it may lead to serious complications such as gastrorrhagia. Furthermore, irAE gastritis is often difficult to identify early due to its diverse symptoms. Although steroid hormones and immunosuppressants are commonly used to reverse irAEs, the best regimen and dosage for irAE gastritis remains uncertain. In addition, the risk of recurrence of irAE gastritis after the reuse of ICIs should be considered. In this editorial, strategies such as early identification, pathological diagnosis, management interventions, and immunotherapy rechallenge are discussed to enable clinicians to better manage irAE gastritis and improve the prognosis of these patients.

Prevalence, biofilm formation, and mass spectrometric characterization of linezolid-resistant Staphylococcus capitis isolated from a tertiary hospital in China.

OBJECTIVES: Linezolid-resistant Staphylococcus capitis (LRSC) has become a new challenge for clinical anti-infective therapy. The present study aimed to investigate the trends of LRSC prevalence in a tertiary hospital of China 2017-2020. The resistance mechanisms, virulence genes, biofilm formation, and mass spectrometric characteristics of LRSC isolates were also analysed. METHODS: This study retrospectively analysed the antibiotic resistance trends of coagulase negative staphylococci (CoNS) isolated from clinical samples collected between 2017-2020. Antimicrobial resistance profiles were tested by micro-broth dilution and the E-test method. Antimicrobial resistance genes and virulence genes were detected by polymerase chain reaction, and dru-typing sequences were obtained by Sanger sequencing. Crystal violet staining in 96-well plates was used to detect biofilm formation ability. Mass spectrometric characterization of LRSC was analysed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) coupled with ClinProTools. RESULTS: The linezolid resistance rate in 3575 CoNS clinical strains was 1.6%, wherein the great majority of was LRSC (91.1%, n = 51/56), with a resistant rate of 15.5% (n = 51/328) in all S. capitis isolates. In this study, 48 out of the 51 LRSC strains and 54 of 277 linezolid-susceptible S. capitis (LSSC) strains were enrolled. G2576T, C2104T, T2130A, C2163T, and T2319C mutations in the 23S rRNA V region and acquisition of cfr were the main linezolid resistant mechanisms in LRSC. The biofilm-forming ability of LRSC was more potent than LSSC, with a higher detection rate of bap (P < 0.05). Eleven mass spectrometric peaks of interest were identified by using MALDI-TOF MS and ClinProTools, which were differently distributed between LRSC and LSSC strains, with the area under the receiver operating characteristic curve of more than 0.8, especially for 5465.37 m/z. CONCLUSIONS: Linezolid resistance was mediated by mutations in the 23S rRNA V region and presence of the cfr gene in LRSC strains. LRSC strains have stronger biofilm-forming ability than LSSC strains, which maybe associated with the adhesion-related gene of bap. Further, linezolid-resistant and linezolid-susceptible S. capitis could be rapidly identified with mass spectrometric characterization. To the best of our knowledge, this study is the first to document the biofilm formation ability of LRSC and the potential usefulness of MALDI-TOF MS for the discrimination of LRSC and LSSC.

[One-step generation of droplet-filled hydrogel microfibers for 3D cell culture using an all-aqueous microfluidic system].

Hydrogel microfibers, which are characterized by flexible mechanical properties, a uniform spatial distribution, large surface areas, and excellent biocompatibility, hold great potential for various biomedical applications. However, the fabrication of heterogeneous hydrogel microfibers with high cell-loading capacity and the ability to carry multiple components via an environmentally friendly method remains challenging. In this study, we developed a novel pneumatic pump-assisted all-aqueous microfluidic system that enables the one-step fabrication of all-aqueous droplet-filled hydrogel microfibers with unique morphologies and adjustable configurations. By designing a pump-valve cycling system and selecting two immiscible fluids with stable water interfaces (dextran and polyethylene glycol), we successfully fabricated alginate microfibers with equidistantly arranged droplets through the ionotropic gelation reaction between sodium alginate and calcium chloride. The droplet size, interdroplet spacing, and microfiber dimensions could be flexibly controlled by adjusting the flow rates of the inner-phase, middle-phase, and outer-phase inlets. The results showed that the system enabled the high-throughput in situ formation of functional three-dimensional cell spheroids. The generated cell spheroids exhibited excellent cell viability and drug-testing functionality, indicating their potential applications in cell cultures. The developed technique offers strong support for future biomedical research and applications, and provides a new approach for the preparation of multifunctional hydrogel microfibers for materials science, tissue engineering, and drug testing.