Functional role of TrIL-1ß in Takifugu rubripes defense against Cryptocaryon irritans infection.

The Japanese puffer, Takifugu rubripes, is a commercially important fish species in China that is under serious threat from white spot disease (cyptocaryoniasis), which leads to heavy economic losses. We previously found that interleukin-1ß (IL-1ß), an important cytokine with a potential role in resistance against pathogens, was one of the most significantly differentially up-regulated proteins in the gills and spleen of T. rubripes infected by the protozoan parasite Cryptocaryon irritans. In this study, we assessed the potential function of T. rubripes IL-1ß (TrIL-1ß) in fish infected with C. irritans. Phylogenetic analysis indicated that the TrIL-1ß protein sequence was most closely related to that of Atlantic salmon (Salmo salar) (67.2 %). The incubation experiments revealed that TrIL-1ß may reduce trophont activity by destroying membranes. Immunofluorescence experiments showed that recombinant TrIL-1ß promoted the expression of endogenous IL-1ß, which penetrated and disrupted the cell membranes of trophonts. Transmission electron microscopy showed that the IL-1ß group had less tissue damage compared with control groups of fish. IL-1ß-small interfering RNA and IL-1ß overexpression experiments were performed in head kidney primary cells, and challenge experiments were performed in vitro. Quantitative RT-PCR results showed that TrIL-1ß regulated and activated MyD88/NF-κB and MyD88/MAPK/p38 signaling pathways during C. irritans infection. TrIL-1ß also promoted the differential expression of IgM, showing that it was involved in humoral immunity of T. rubripes. The cumulative mortality experiment show that TrIL-1ß could protect fish against C. irritans infection. These results enrich current knowledge about the molecular structure of TrIL-1ß. They also suggested that recombinant TrIL-1ß could be used as an adjuvant in a subunit vaccine against C. irritans infection, which is of profound importance for the prevention and control of parasitic diseases in T. rubripes.

DNA Methylation Analysis Reveals Potential Mechanism in Takifugu rubripes Against Cryptocaryon irritans Infection.

Takifugu rubripes (T. rubripes) is a valuable commercial fish, and Cryptocaryon irritans (C. irritans) has a significant impact on its aquaculture productivity. DNA methylation is one of the earliest discovered ways of gene epigenetic modification and also an important form of modification, as well as an essential type of alteration that regulates gene expression, including immune response. To further explore the anti-infection mechanism of T. rubripes in inhibiting this disease, we determined genome-wide DNA methylation profiles in the gill of T. rubripes using whole-genome bisulfite sequencing (WGBS) and combined with RNA sequence (RNA-seq). A total of 4659 differentially methylated genes (DMGs) in the gene body and 1546 DMGs in the promoter between the infection and control group were identified. And we identified 2501 differentially expressed genes (DEGs), including 1100 upregulated and 1401 downregulated genes. After enrichment analysis, we identified DMGs and DEGs of immune-related pathways including MAPK, Wnt, ErbB, and VEGF signaling pathways, as well as node genes prkcb, myca, tp53, and map2k2a. Based on the RNA-Seq results, we plotted a network graph to demonstrate the relationship between immune pathways and functional related genes, in addition to gene methylation and expression levels. At the same time, we predicted the CpG island and transcription factor of four immune-related key genes prkcb and mapped the gene structure. These unique discoveries could be helpful in the understanding of C. irritans pathogenesis, and the candidate genes screened may serve as optimum methylation-based biomarkers that can be utilized for the correct diagnosis and therapy T. rubripes in the development of the ability to resist C. irritans infection.

Medical errors, affected sites, and adverse consequences among patients in the orthopaedic department: Does age matter?

Background: Orthopaedics have become the focus of research on patient safety due to the high incidence of medical errors. Previous studies were based on all orthopaedic patients and rarely conducted empirical analyses from the perspective of age. This study aimed to fill the academic gap in the age variable by comparing medical errors, affected sites, and adverse consequences in orthopaedic patients. Methods: This retrospective study included 329 litigation claims against orthopaedists using data from China Judgments Online. First, we performed computer crawling and screened 5,237 litigation documents using keywords, including medical errors. Second, 2,536 samples were retained through systematic random sampling, and 549 irrelevant cases were deleted after manual reading. Finally, three clinicians from different medical departments selected 329 incidents related to orthopaedics for further analysis, according to the description of the lawsuits. Three other professional orthopaedists evaluated the patients' ages, affected sites of medical errors, and adverse consequences. Results: The greatest number of medical errors was observed in the joints (30.43%) for all orthopaedic patients. However, adult patients (aged 18-60 years) were most susceptible to errors in the extremities (30.42%). A higher rate of complications was associated with a higher rate of morbidity/mortality for the corresponding patients. Medical errors correlated with complications occurred in the following sites: joints (15.38%), extremities (12.50%), spine (16.95%), multiple sites (15.38%), and hands and feet (14.81%). In addition to surgical errors, over 10% of all orthopaedic patients experienced missed diagnoses. The incidence of insufficient adherence to informed consent obligations was 13.5% among adult patients and was much higher in paediatric and older adults patients. When orthopaedic patients suffered from medical technical errors, iatrogenic mortality/morbidity would decrease by 0.3% for one unit increase in age. Conclusion: Dividing patients into different ages demonstrated diverse results in terms of medical errors and affected sites. Negligence in diagnosis and examination can be fatal factors that endanger safety, and complications may cause morbidity/mortality. When patients suffered from technical errors, age is inversely proportional to mortality/morbidity. Special attention needs to be paid to technical errors in the younger older adults population (60-64 years old), which has inspired implications in promoting aging and public health.

Effect of Zusanli Acupoint Injection with Anisodamine on Postoperative Recovery Quality of Patients Undergoing Bariatric Surgery.

PURPOSE: To evaluate the influence of anisodamine injection at the Zusanli (ST36) on early postoperative recovery quality in patients who have undergone laparoscopic sleeve gastrectomy. MATERIALS AND METHODS: 141 patients undergoing laparoscopic sleeve gastrectomy were randomly divided into the control group (group C), the normal saline group (group S) and the anisodamine group (group A). Acupuncture point injections were administered after induction of general anesthesia. The quality of recovery-40 questionnaire (QoR-40) scores were documented preoperatively (D0) and on the 1st (D1), 3rd (D3) and 7th (D7) days postoperatively. Additional metrics included: the numerical rating scale (NRS) for pain, postoperative nausea and vomiting (PONV), assessment and analgesic consumption 24-h post-extubation and the initial postoperative times for ambulation and anal exhaust. Substance P (SP), ß-endorphin (ß-EP), motilin (MTL) and gastrin (GAS) were quantified at 24-h post-surgery. RESULTS: Compared with group C, group A demonstrated an elevation in QoR-40 scores and physical comfort dimensions during D1-3, and an increased pain scores during D1-7; group S exhibited an augmentation in QoR-40 scores and pain scores on D1 (p < 0.05). Compared with group S, group A improved QoR-40 scores on D1 and pain scores during D1-3 (p < 0.05). SP, ß-EP, MTL and GAS presented significant variances among the groups 24-h post-surgery (p < 0.05). There were significant differences between the groups in NRS pain scores and PONV scores at 24-h postoperatively, dosage of dizocin on the first postoperative day, and time to first anal defecation (p < 0.05). CONCLUSION: The administration of anisodamine via ST36 acupoint injections has been demonstrated to facilitate the recuperation of gastrointestinal functionality, to alleviate postoperative pain and nausea, and substantially to enhance the quality of early postoperative recovery.

Copper exposure causes alteration in the intestinal microbiota and metabolites in Takifugu rubripes.

Copper is an environmental pollutant, and copper in aquatic environments mainly comes from soil and water. It enters the environment through atmospheric deposition, sewage discharge, and industrial production, and enters aquatic organisms, causing toxicity. Takifugu rubripes (T. rubripes) is a marine fish with high economic value. Due to the toxic effects of heavy metals on aquatic organisms such as fish, it can affect the gut community and metabolites of fish. The gut is an important channel for fish to communicate with the outside world and a necessary pathway for the metabolism of nutrients and toxic substances in the fish body. Studies have shown that due to changes in global water emissions and the high sensitivity of aquatic organisms to the environment, copper may pose greater potential hazards to aquatic organisms. Copper poses a greater risk to aquatic species than other heavy metals and metal/metal like pollutants (such as cadmium, lead, mercury, arsenic, etc.) . In order to elucidate the effects of copper exposure on the gut of T. rubripes. In this study, we exposed T. rubripes to 0, 50, 100, or 500 µg/L of copper for three days, the effects of copper exposure on the gut microbiota structure and metabolites of the T. rubripes were investigated using 16 S rRNA gene and metabolomics techniques. The research results indicate that with the increase copper concentration, the intestinal tissue of T. rubripes undergoes significant damage. 16 S rRNA sequencing results show that copper exposure alters the structure and metabolites of intestinal microbiota. Copper exposure of 100 and 500 µg/L inhibited the colonization of the bacterial gut, disrupted the intestinal barrier, and made the fish susceptible to the pathogens. Liquid chromatography-mass spectrometry analysis showed that copper regulated the production of metabolites such as L-histidine, arachidonic acid, and L-glutamic acid, which are related to energy and immunity. Microbiome-metabolome correlation analysis showed that Subdoligranulum, Family_XIII_AD3011_group, and Clostridium_sensu_stricto_1 were the key bacteria for copper ion intervention, and they might up-regulate the levels of metabolites such as indole-3-acetic acid, 3-indoleacrylic acid, and 5-hydroxyindole in the tryptophan metabolism pathway. In summary, our research has demonstrated that copper exposure can cause pathological changes in the intestinal tissue of the T. rubripes. High concentrations of copper ions can affect the colonization of the T. rubripes microbiota in the intestine, damage the fish's immune system, and alter the structure and metabolites of the intestinal microbiota, this can lead to intestinal metabolic dysfunction. providing a reference for the evaluation of the biological toxicity effects of heavy metal elements in the marine environment. This study provides a reference for evaluating the biological toxicity effects of heavy metal elements in marine environments.

Effect of preoperative oral carbohydrates on insulin resistance in patients undergoing laparoscopic cholecystectomy: a randomized controlled trial.

PURPOSE: The present research seeks to clarify the consequences of two specific preoperative oral carbohydrate (POC) amounts on insulin resistance (IR) and stomach evacuation in laparoscopic cholecystectomy (LC) patients. METHODS: A total of 129 patients set for elective LC procedures were randomly assigned to a control group (C, n = 45), a 200 mL POC group (P1, n = 42), and a 400 mL POC group (P2, n = 42). The C group was fasted from midnight until surgery, whereas the P1 and P2 groups received their respective carbohydrate volumes 2-4 h before anesthesia. Fasting blood glucose, insulin, and glucagon concentrations were measured at three junctures. IR metrics were derived by employing the homeostasis model assessment. Gastric volume was measured before anesthesia using gastric ultrasound. Inter-group comparisons included IR indicators, subjective comfort scores, and hemodynamic data. RESULTS: At T2, the C group exhibited reduced glucose concentrations compared to the P2 group (4.73 ± 0.64 vs. 5.26 ± 1.02 mmol/L, p < 0.05). The Perlas grading indicated that grade 1 was more prevalent in the P2 group than in the P1 and C groups (18 [42.9%] vs. 6 [14.3%] and 1 [2.2%], p < 0.05). Additionally, thirst and hunger metrics for the P2 group were notably reduced compared to the C group at both T2 and T3. CONCLUSION: Administering either 200 mL or 400 mL of carbohydrates 2-4 h pre-surgery had no detectable impact on IR or gastric volume in LC patients. TRIAL REGISTRATION: ChiCTR, ChiCTR2200065648. Registered January 13, 2023, http://www.chictr.org.cn .

Rev-erbα attenuates diabetic myocardial injury through regulation of ferroptosis.

Diabetes is a widespread disease that threatens the life and health of human beings, and diabetic cardiomyopathy (DCM) is one of the major complications of diabetic patients. The pathological mechanisms of DCM are complex, including inflammation, endoplasmic reticulum stress, and oxidative stress that have been reported previously. Although recent studies suggested that ferroptosis is also involved in the progression of DCM, the exact mechanism remains unclear. Rev-erbα cardiac conditional knockout mice were generated and type 2 diabetes were induced by high fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ) in in vivo experiments. In parallel, our in vitro experiments entailed the introduction of elevated levels of glucose (HG) and palmitic acid (PA) to induce glycolipid toxicity in H9c2 cardiomyocytes. Further deterioration of cardiac function was detected by echocardiography after the clock gene rev-erbα was knocked out. This was accompanied by significant elevations in markers of inflammation, myocardial fibrosis, and oxidative stress. In addition, iron content, transmission electron microscopy (TEM), and RT-PCR assays confirmed significantly increased levels of ferroptosis in rev-erbα-deficient DCM. Intriguingly, Co-Immunoprecipitation (Co-IP) data uncovered an interaction between rev-erbα and nuclear factor E2-related factor 2 (NRF2) in diabetic myocardial tissues. It is worth highlighting that ferroptosis within cardiomyocytes witnessed significant mitigation upon the administration of sulforaphane (SFN), an NRF2 agonist, to HG + PA-incubated H9c2 cells. Our study demonstrates for the first time that knockdown of the clock gene rev-erbα exacerbates myocardial injury and ferroptosis in type 2 diabetic mice, which can be reversed by activating NRF2.

Tandem mass tag (TMT) quantitative proteomics and phosphoproteomic of Takifugu rubripes infected with Cryptocaryon irritans.

In this study, we identified the differentially expressed proteins in gills stimulated by infected ciliates and analyzed the immune mechanisms of T. rubripes infected with the ciliate Cryptocaryon irritans. Through liquid chromatography analysis, a total of 144 proteins were identified with significant differences, of which 58 were upregulated and 86 were downregulated. Among phosphorylated proteins, we identified a total of 167 significantly different phosphorylated proteins, of which 44 were upregulated, 123 were downregulated, 60 were upregulated, and 208 were downregulated. We analyzed the data of proteomics and Phosphorylated proteome quantification protein omics to finally identify three phosphorylated proteins (RPS27, eNOS and CaM) and two phosphorylated protein kinases(CaMKII and MAPK1) as potential biomarkers for T. rubripes immune responses. We finally identified three phosphorylated proteins (RPS27, eNOS and CaM) and two phosphorylated protein kinases (CaMKII and MAPK1) as potential biomarkers of immune response of T. rubripes. Our research findings provide new insights into the immune mechanism of T. rubripes, which may serve as an effective indicator of C. irritans infection in T. rubripes.

Expression and clinical significance of HER2/neu, aromatase P450 and adhesion molecule CD24 in endometrial cancer.

This study aimed at exploring the expression and clinical significance of aromatase P450, adhesion molecule CD24 and HER2/neu in endometrial cancer. The expression of aromatase P450, adhesion molecule CD24 and HER2/neu was detected by immunohistochemistry in 15 cases of endometrial hyperplasia group, 50 cases of endometrial adenocarcinoma and 3 cases of uterine papillary adenocarcinoma, with 15 cases of normal endometrium as control group. We detected no expression of aromatase P450, adhesion molecule CD24 or HER2/neu in control group. Aromatase P450 positive expression rate was 66.7% in endometrial hyperplasia group and 70.3% in endometrial carcinoma group, without significant difference (p>0.05). There was no significant difference (p>0.05) in the positive expression rate of aromatase P450 between different myometrial invasion groups of endometrial adenocarcinomas. CD24 positive expression rate was 40.0% in endometrial hyperplasia group and 79.6% in endometrial carcinoma group, with significant difference (p<0.05). HER2/neu positive expression rate was 26.7% in the endometrial hyperplasia group and 57% in endometrial carcinoma group, with significant difference (p<0.05). In conclusion, aromatase P450 may be one factor associated with endometrial cancer cell proliferation, while CD24 and HER2/neu may be important factors associated with the invasion and metastasis of endometrial cancer.

Proteomics and Phosphoproteomic Analysis to Identify Spleen of Takifugu rubripes Infected Cryptocaryon irritans.

Takifugu rubripes is important commercially fish species in China and it is under serious threat from white spot disease (cyptocaryoniasis), which leads to heavy economic losses. In this study, we used proteomics and phosphoproteomic analysis to identify differentially abundant proteins in the spleen of T. rubripes infected with the Cryptocaryon irritans. We identified 5,307 proteins and 6,644 phosphorylated sites on 2,815 phosphoproteins using high-throughput proteomics analysis of the spleen of T. rubripes based on 26,421 unique peptides and 5,013 modified peptides, respectively. The 5,307 quantified host proteins, 40 were upregulated and 43 were downregulated in the infection group compared to the control group. Among the 2815 phosphoproteins, 44/120 were upregulated/downregulated, and 62/151 were upregulated/downregulated in the 6644 quantified phosphosites. Using the combination of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, screening for significantly different phosphoproteins, motif analysis and protein-protein interaction analysis, we ultimately identified three phosphorylated proteins (G-protein-signaling modulator 1-like, zinc finger protein 850-like, and histone H1-like) and three phosphorylated protein kinases (serine/threonine-protein kinase homolog isoform X2, mitogen-activated protein kinase 5-like, and protein kinase C theta type) as potential biomarkers for T. rubripes immune responses. We then screened the phosphorylation sites of these biomarker proteins for further verification. Based on our results, we speculate that phosphorylation modification of the phosphorylation sites is involved in the immunity of T. rubripes against C. irritans.

Inhibition mechanism of MRTX1133 on KRASG12D: a molecular dynamics simulation and Markov state model study.

The mutant KRAS was considered as an "undruggable" target for decades, especially KRASG12D. It is a great challenge to develop the inhibitors for KRASG12D which lacks the thiol group for covalently binding ligands. The discovery of MRTX1133 solved the dilemma. Interestingly, MRTX1133 can bind to both the inactive and active states of KRASG12D. The binding mechanism of MRTX1133 with KRASG12D, especially how MRTX1133 could bind the active state KRASG12D without triggering the active function of KRASG12D, has not been fully understood. Here, we used a combination of all-atom molecular dynamics simulations and Markov state model (MSM) to understand the inhibition mechanism of MRTX1133 and its analogs. The stationary probabilities derived from MSM show that MRTX1133 and its analogs can stabilize the inactive or active states of KRASG12D into different conformations. More remarkably, by scrutinizing the conformational differences, MRTX1133 and its analogs were hydrogen bonded to Gly60 to stabilize the switch II region and left switch I region in a dynamically inactive conformation, thus achieving an inhibitory effect. Our simulation and analysis provide detailed inhibition mechanism of KRASG12D induced by MRTX1133 and its analogs. This study will provide guidance for future design of novel small molecule inhibitors of KRASG12D.

Different impact on health outcomes of long-term care insurance between urban and rural older residents in China.

Long-term care insurance (LTCI) is garnering attention internationally and is being considered a public policy in a growing number of countries. Previous research has focused on the effects of LTCI in developed countries, ignoring the health outcomes of developing countries, especially in rural regions. Therefore, this study investigates whether different impact on health outcomes is present in the effects of LTCI between urban and rural residents in China. We employed a quasi-experimental design with data from the China Health and Retirement Longitudinal Survey. The specific implementation time of each pilot city was sorted according to the LTCI policy texts, dividing these pilot cities into the treatment group and control group. Finally, difference-in-differences analyses were utilized to evaluate the health effects of LTCI between urban and rural residents, and the health effect in urban areas was further tested. The implementation of LTCI has effectively enhanced the self-rating health (SRH) of the entire group of residents; however, this effect may only be significant for the urban group. In particular, LTCI can increase the SRH of urban residents by 0.377 units compared to the urban residents without LTCI (P < 0.01). The result of the placebo effect test further verifies that LTCI could improve the health of residents to some extent. In China, LTCI may have triggered different impacts on health outcomes between urban and rural residents, and may not improve the SRH of rural residents and only prove efficacious for urban residents. Government and policy-makers should give more attention to the rural group as it needs long-term care the most.

Impacts on children's health of adverse childhood experiences of their mothers: A gender-specific mediation analysis using data from the China Health and Retirement Longitudinal Study.

BACKGROUND: Numerous people have suffered adverse childhood experiences (ACEs) that can have lasting negative consequences. However, few studies have focused on maternal ACEs' effect on their children's health. This study aimed to evaluate the impact on children's health of ACEs that their mothers experienced. METHODS: Data from the China Health and Retirement Longitudinal Study (CHARLS) 2018 combined with the CHARLS 2014 Life History Survey were analyzed. The logistic regression was used to investigate maternal ACEs' impact on their children's health. Based on the stepwise regression model and bias-corrected bootstrap, we estimated the mediating effects. RESULTS: Maternal ACEs could result in harm to the health of children (P < 0.05). If the types of maternal ACEs increased by one unit, the odds ratio of their children's poor health would rise by 9.6 %. Moreover, if the types of maternal ACEs increased by one unit, the odds ratio of daughters' and sons' poor health would increase by 8.3 % and 10.2 %, respectively. Three mediating mechanisms of mothers' education, physical health, and mental health were confirmed by empirical tests. LIMITATIONS: We could not employ objective indicators to measure children's health. Meanwhile, maternal ACEs were all self-reported from the mothers' recollection, which might descend the accuracy due to memory bias. CONCLUSION: Maternal ACEs harmed the health of both their sons and daughters. The children's health would deteriorate as the maternal ACEs increased. Mother's education, physical health, and mental health mediated the relationships between maternal ACEs and children's health.

Computational investigation of functional water molecules in GPCRs bound to G protein or arrestin.

G protein-coupled receptors (GPCRs) are membrane proteins constituting the largest family of drug targets. The activated GPCR binds either the heterotrimeric G proteins or arrestin through its activation cycle. Water molecules have been reported to play a role in GPCR activation. Nevertheless, reported studies are focused on the hydrophobic helical bundle region. How water molecules function in GPCR bound either G protein or arrestin is rarely studied. To address this issue, we carried out computational studies on water molecules in both GPCR/G protein complexes and GPCR/arrestin complexes. Using inhomogeneous fluid theory (IFT), we locate all possible hydration sites in GPCRs binding either to G protein or arrestin. We observe that the number of water molecules on the interaction surface between GPCRs and signal proteins are correlated with the insertion depths of the α5-helix from G-protein or "finger loop" from arrestin in GPCRs. In three out of the four simulation pairs, the interfaces of Rhodopsin, M2R and NTSR1 in the G protein-associated systems show more water-mediated hydrogen-bond networks when compared to these in arrestin-associated systems. This reflects that more functionally relevant water molecules may probably be attracted in G protein-associated structures than that in arrestin-associated structures. Moreover, we find the water-mediated interaction networks throughout the NPxxY region and the orthosteric pocket, which may be a key for GPCR activation. Reported studies show that non-biased agonist, which can trigger both GPCR-G protein and GPCR-arrestin activation signal, can result in pharmacologically toxicities. Our comprehensive studies of the hydration sites in GPCR/G protein complexes and GPCR/arrestin complexes may provide important insights in the design of G-protein biased agonists.

Gender differences in medical errors among older patients and inequalities in medical compensation compared with younger adults.

Background: Despite growing evidence focusing on health inequalities in older adults, inequalities in medical compensation compared with younger adults and gender disparities of medical errors among older patients have received little attention. This study aimed to disclose the aforementioned inequalities and examine the disparities in medical errors among older patients. Methods: First, available litigation documents were searched on "China Judgment Online" using keywords including medical errors. Second, we compiled a database with 5,072 disputes. After using systematic random sampling to retain half of the data, we removed 549 unrelated cases. According to the age, we identified 424 and 1,563 cases related to older and younger patients, respectively. Then, we hired two frontline physicians to review the documents and independently judge the medical errors and specialties involved. A third physician further considered the divergent results. Finally, we compared the medical compensation between older and younger groups and medical errors and specialties among older patients. Results: Older patients experienced different medical errors in divergent specialties. The medical error rate of male older patients was over 4% higher than that of females in the departments of general surgery and emergency. Female older patients were prone to adverse events in respiratory medicine departments and primary care institutes. The incidence of insufficient implementation of consent obligation among male older patients was 5.18% higher than that of females. However, females were more likely to suffer adverse events at the stages of diagnosis, therapy, and surgical operation. The total amount of medical compensation obtained by younger patients was 41.47% higher than that of older patients. Conclusions: Except for the common medical errors and departments involved, additional attention should be paid to older patients of different genders according to the incidence of medical errors. Setting up the department of geriatrics or specialist hospitals is also an important alternative to improve patient safety for older people. Furthermore, there may be inequality in medical compensation in older patients due to the tort liability law of China.

The synthesis and antibacterial activity study of ruthenium-based metallodrugs with a membrane-disruptive mechanism against Staphylococcus aureus.

The wide spread of drug-resistant bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), poses a tremendous threat to global health. Of particular concern, resistance to vancomycin, linezolid, and daptomycin has already been reported in clinical MRSA strains. New antibacterial agents are urgently needed to overcome this crisis. Here, we designed and synthesized a series of ruthenium-based antibacterial agents via targeting bacterial membrane integrity. Structure-activity relationship studies demonstrated that both the lipophilicity/hydrophilicity ratio and biphenyl group play an important role in elevating the antibacterial activity. To characterize the antibacterial mechanism, we combined scanning electron microscopy, propidium iodide dyeing, and DNA leakage assays. The results demonstrated that Ru2 could destroy the integrity of bacterial cell membranes. In addition, Ru2 can efficiently inhibit biofilm formation and α-hemolysin secretion from Staphylococcus aureus. Finally, in both a mouse skin infection model and a G. mellonella wax worm infection model, Ru2 showed significant antibacterial activity in vivo. Moreover, the Ru2 complex was almost non-toxic. Thus, this work demonstrated that ruthenium-based complexes bearing a biphenyl group are promising agents to combat bacterial infection.

Synthesis of ruthenium polypyridine complexes with benzyloxyl groups and their antibacterial activities against Staphylococcus aureus.

Four new ruthenium polypyridyl complexes, [Ru(bpy)2(BPIP)](PF6)2 (Ru(II)-1), [Ru(dtb)2(BPIP)](PF6)2 (Ru(II)-2), [Ru(dmb)2(BPIP)](PF6)2 (Ru(II)-3) and [Ru(dmob)2(BPIP)](PF6)2 (Ru(II)-4) (bpy = 2,2'-bipyridine, dtb = 4,4'-di-tert-butyl-2,2'-bipyridine, dmb = 4,4'-dimethyl-2,2'-bipyridine, dmob = 4,4'-dimethoxy-2,2'-bipyridine and BPIP = 2-(3,5-bis(benzyloxyl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) had been synthesized and characterized. Their antimicrobial activities were investigated against Staphylococcus aureus (S. aureus) and four complexes showed obvious antibacterial effect, especially the minimum inhibition concentration (MIC) value of Ru(II)-3 was only 4 µg/mL. In addition, Ru(II)-3 was able to kill bacteria quickly and inhibit the formation of biofilm. Meanwhile, the cooperative effect between Ru(II)-3 and general antibiotics were tested and the results showed that Ru(II)-3 could enhance the susceptibility of S. aureus to different types of antibiotics. Most importantly, Ru(II)-3 hardly showed cytotoxicity to mammalian erythrocytes both in homelysis experiment and G. mellonella model. After being injected with high doses of the Ru(II)-3in vivo, the G. mellonella worms still exhibited high survival rates. Finally, a mouse skin infection model and G. mellonella infection model was built to determine the antibacterial activity of Ru(II)-3in vivo. The antibacterial mechanism of Ru(II)-3 was probably related to the membrane-disruption. Taken together, ruthenium polypyridine complexes with benzyloxyl groups had the potential to develop an attractive and untraditional antibacterial agent with new mode of action.

Ruthenium(II) complexes targeting membrane as biofilm disruptors and resistance breakers in Staphylococcus aureus bacteria.

The development of ruthenium-based complexes or antimicrobial peptides are identified as a promising strategy for combating drug-resistant bacteria. In this work, four biphenyl-based antibacterial ruthenium complexes by targeting membrane integrity, which act as antimicrobial peptides mimics, were designed and synthesized. In vitro antimicrobial screening demonstrated that four complexes could absolutely inhibit the growth of Staphylococcus aureus (S. aureus) with MIC values ranging from 15.6 to 100 µg/mL. The most active complex Ru(Ⅱ)-1 (MIC = 15.6 µg/mL) could kill S. aureus through targeting the membrane integrity without detectably resistance frequencies. Further investigation including bacteria biofilm formation, hemolysin activity and checkerboard assay were performed as well. The results revealed that Ru(Ⅱ)-1 could inhibit the biofilm formation and α-hemolysis secretion in S. aureus at subinhibitory concentration. More interestingly, the combination use of Ru(Ⅱ)-1 and five traditional antibiotics showing synergistic effect. Finally, based on the mouse model of S. aureus skin infection, Ru(Ⅱ)-1 showed important antibacterial efficacy against S. aureus in vivo, and almost non-toxic against mouse tissue. Our study indicates that introducing membrane targeting ligands onto ruthenium complexes may be an underappreciated strategy for developing antibacterial agents.

Silver-mediated radical oxytrifluoromethylation of unsaturated carboxylic acids for the synthesis of γ-trifluoromethylthio lactones.

An efficient silver-mediated oxidative trifluoromethylthiolation of unsaturated carboxylic acids to construct trifluoromethylthiol-containing lactones has been disclosed. In this protocol no metal-catalysts was added, and preliminary mechanism investigations suggested that a free-radical pathway should be involved in the process. High functional group tolerance and excellent yields were demonstrated by the efficient preparation of a wide range of γ-trifluoromethylthiolated phthalides.

Relative humidity sensor based on a silver nano-grating made from DVD discs.

A relative humidity sensor based on a silver nano-grating was proposed. By stripping and cleaning commercially available CD and DVD discs, polycarbonate plates with different grating periods are obtained. These plates as templates are coated with a layer of sputtered silver film to form silver nano-gratings, which exhibit refractive index sensing sensitivities of 517 nm/RIU and 742.9 nm/RIU, respectively. The finite-difference time-domain simulation results conform the excited surface plasmon polariton modes and localized surface plasmon modes on the nano-grating. By spin coating a layer of humidity-sensitive porous silica with optimized thickness, the silver nano-grating shows a relative humidity detection sensitivity of 0.23 nm/%RH.