Overcoming neutrophil-induced immunosuppression in postoperative cancer therapy: Combined sialic acid-modified liposomes with scaffold-based vaccines.

Immunotherapy is a promising approach for preventing postoperative tumor recurrence and metastasis. However, inflammatory neutrophils, recruited to the postoperative tumor site, have been shown to exacerbate tumor regeneration and limit the efficacy of cancer vaccines. Consequently, addressing postoperative immunosuppression caused by neutrophils is crucial for improving treatment outcomes. This study presents a combined chemoimmunotherapeutic strategy that employs a biocompatible macroporous scaffold-based cancer vaccine (S-CV) and a sialic acid (SA)-modified, doxorubicin (DOX)-loaded liposomal platform (DOX@SAL). The S-CV contains whole tumor lysates as antigens and imiquimod (R837, Toll-like receptor 7 activator)-loaded PLGA nanoparticles as immune adjuvants for cancer, which enhance dendritic cell activation and cytotoxic T cell proliferation upon localized implantation. When administered intravenously, DOX@SAL specifically targets and delivers drugs to activated neutrophils in vivo, mitigating neutrophil infiltration and suppressing postoperative inflammatory responses. In vivo and vitro experiments have demonstrated that S-CV plus DOX@SAL, a combined chemo-immunotherapeutic strategy, has a remarkable potential to inhibit postoperative local tumor recurrence and distant tumor progression, with minimal systemic toxicity, providing a new concept for postoperative treatment of tumors.

Impact of LuxS on virulence and pathogenicity in Klebsiella pneumoniae exhibiting varied mucoid phenotypes.

How the LuxS/AI-2 quorum sensing (QS) system influences the pathogenicity of K. pneumoniae is complicated by the heterogeneity of the bacterial mucoid phenotypes. This study aims to explore the LuxS-mediated regulation of the pathogenicity of K. pneumoniae with diverse mucoid phenotypes, including hypermucoid, regular-mucoid, and nonmucoid. The wild-type, luxS knockout, and complemented strains of three K. pneumoniae clinical isolates with distinct mucoid phenotypes were constructed. The results revealed the downregulation of virulence genes of regular-mucoid, and nonmucoid but not hypermucoid strains. The deletion of luxS reduced the pathogenicity of the regular-mucoid, and nonmucoid strains in mice; while in hypermucoid strain, luxS knockout reduced virulence in late growth but enhanced virulence in the early growth phase. Furthermore, the absence of luxS led the regular-mucoid and nonmucoid strains to be more sensitive to the host cell defense, and less biofilm-productive than the wild-type at both the low and high-density growth state. Nevertheless, luxS knockout enhanced the resistances to adhesion and phagocytosis by macrophage as well as serum-killing, of hypermucoid K. pneumoniae at its early low-density growth state, while it was opposite to those in its late high-density growth phase. Collectively, our results suggested that LuxS plays a crucial role in the pathogenicity of K. pneumoniae, and it is highly relevant to the mucoid phenotypes and growth phases of the strains. LuxS probably depresses the capsule in the early low-density phase and promotes the capsule, biofilm, and pathogenicity during the late high-density phase, but inhibits lipopolysaccharide throughout the growth phase, in K. pneumoniae.IMPORTANCECharacterizing the regulation of physiological functions by the LuxS/AI-2 quorum sensing (QS) system in Klebsiella pneumoniae strains will improve our understanding of this important pathogen. The genetic heterogeneity of K. pneumoniae isolates complicates our understanding of its pathogenicity, and the association of LuxS with bacterial pathogenicity has remained poorly addressed in K. pneumoniae. Our results demonstrated strain and growth phase-dependent variation in the contributions of LuxS to the virulence and pathogenicity of K. pneumoniae. Our findings provide new insights into the important contribution of the LuxS/AI-2 QS system to the networks that regulate the pathogenicity of K. pneumoniae. Our study will facilitate our understanding of the regulatory mechanisms of LuxS/AI-2 QS on the pathogenicity of K. pneumoniae under the background of their genetic heterogeneity and help develop new strategies for diminished bacterial virulence within the clinical K. pneumoniae population.

Long-term efficacy of venous sinus stenting in the treatment of idiopathic intracranial hypertension.

BACKGROUNDS: Previous studies have suggested that cerebral dural sinus stenosis could be a possible underlying cause of idiopathic intracranial hypertension (IIH). Venous sinus stenting (VSS) has emerged as a potential alternative for treating IIH related to dural sinus stenosis. However, most of the documented studies have been conducted in Western countries. In this study, we present the results of 16 Chinese IIH patients who underwent VSS treatment in our single center. METHODS: We prospectively collected angiographic and manometric data from IIH patients who underwent angioplasty/stenting. All patients had confirmed dural sinus stenosis and had failed maximal medical therapy (MMT). Demographic, clinical, and radiological presentation, as well as long-term follow-up outcomes were collected retrospectively. RESULTS: A total of 16 patients who underwent VSS were enrolled in the present study. Demographic data revealed a mean age of 40 (range 20-55), with 69% (11/16) being female, and a mean body mass index (BMI) of 27.05 (range 19.18-38.04) kg/m2 . All patients presented with papilledema and visual disturbances. During a median follow-up period of 47.5 months, 93.75% (15/16) of patients reported improvement in symptoms, although only 37.5% (6/16) experienced complete resolution. Headaches, blurred vision, and amaurosis related to increased pressure improved in 100% (8/8), 81.25% (13/16), and 75% (3/4) of patients, respectively. However, one patient suffered cerebral infarction and secondary epilepsy soon after VSS, and another patient had recurrence of symptoms due to stent wall thrombosis 2 years later. CONCLUSIONS: The significance of venous sinus stenosis in the development of IIH may be undervalued. Our study, based on a Chinese case series, affirms the long-term safety and effectiveness of VSS in treating IIH patients with relatively lower BMI than those from Western countries.

Combining with domiphen bromide restores colistin efficacy against colistin-resistant Gram-negative bacteria in vitro and in vivo.

Today, colistin is considered a last-resort antibiotic for treating multidrug-resistant (MDR) Gram-negative bacteria (GNB). However, the increased and improper use of colistin has led to the emergence of colistin-resistant (Col-R) GNB. Thus, it is urgent to develop new drugs and therapies in response to the ongoing emergence of colistin resistance. In this study, we investigated the antibacterial and antibiofilm activities of the quaternary ammonium compound domiphen bromide (DB) in combination with colistin against clinical Col-R GNB both in vitro and in vivo. Checkerboard assay and time-kill analysis demonstrated significant synergistic antibacterial effects of the colistin/DB combination. The synergistic antibiofilm activity was confirmed through crystal violet staining and scanning electron microscopy (SEM). Furthermore, the colistin/DB combination exhibited increased survival rates in infected larvae and reduced bacterial loads in a mouse thigh infection model. The cytotoxicity measurement and hemolysis test showed that the combination did not adversely affect cell viability at synergistic concentrations. The alkaline phosphatase (ALP) leak test and propidium iodide (PI) staining analysis further revealed that the colistin/DB combination enhanced the therapeutic effect of colistin by altering bacterial membrane permeability. The ROS assays revealed that the combination induced the accumulation of bacterial ROS, leading to bacterial death. In conclusion, our study is the first to identify DB as a colistin potentiator, effectively restoring the sensitivity of bacteria to colistin. It provides a promising alternative approach for combating Col-R GNB infections.

Autumn and spring observations of PM2.5-bound polycyclic aromatic hydrocarbons and nitro-polycyclic aromatic hydrocarbons in China and Japan.

The transboundary transport of polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) aggravated by the East Asian winter monsoon is a major atmospheric environmental issue in East Asia. To thoroughly elucidate the role of the East Asian monsoon on regional PAH and NPAH pollution in East Asia, PM2.5-bound PAHs and NPAHs were investigated concurrently at five sites in Beijing and Shenyang in China and Tsukuba, Kanazawa, and Wajima in Japan in autumn (November 2018) and spring (March 2019). During both autumn and spring sampling periods, the concentrations of PM2.5, PAHs, and NPAHs at sites in China were 1-2 orders of magnitude higher than those at sites in Japan, and showed an opposite temporal variation, with higher concentrations during the autumn sampling period due to intensive emissions and unfavourable weather conditions. During the sampling periods, PAHs at the Beijing and Shenyang sites had mixed sources of traffic emissions and coal and biomass combustion, while those at the Tsukuba, Kanazawa, and Wajima sites were mainly characterized by domestic traffic emissions. In addition, NPAHs at the five sites were jointly affected by primary combustion sources and atmospheric generation, with a greater contribution of atmospheric generation to the Beijing and Shenyang sites. Based on backwards trajectory clustering and concentration-weighted trajectory analysis, external contributions to PM2.5, PAHs, and NPAHs at each site were relatively stable during the two sampling periods, and potential source areas were mainly distributed in domestic cities and nearby sea areas. Therefore, the apparent temporal differences in the characteristics and sources of pollutants between sites in the two countries indicate that transboundary pollution dominated by the East Asian winter monsoon was unobvious in autumn and spring. The results of the study provide a time-specific solution for the effective management of regional air pollution during the East Asian winter monsoon.

Repolarizing Tumor-Associated Macrophages and inducing immunogenic cell Death: A targeted liposomal strategy to boost cancer immunotherapy.

Cancer immunotherapy has shown promise in treating various malignancies. However, the presence of an immunosuppressive tumor microenvironment (TME) triggered by M2 tumor-associated macrophages (TAMs) and the limited tumor cell antigenicity have hindered its broader application. To address these challenges, we developed DOX/R837@ManL, a liposome loaded with imiquimod (R837) and doxorubicin (DOX), modified with mannose-polyethylene glycol (Man-PEG). DOX/R837@ManL employed a mannose receptor (MRC1)-mediated targeting strategy, allowing it to accumulate selectively at M2 Tumor associated macrophages (TAMs) and tumor sites. R837, an immune adjuvant, promoted the conversion of immunosuppressive M2 TAMs into immunostimulatory M1 TAMs, and reshaped the immunosuppressive TME. Simultaneously, DOX release induced immunogenic cell death (ICD) in tumor cells and enhanced tumor cell antigenicity by promoting dendritic cells (DCs) maturation. Through targeted delivery, the synergistic action of R837 and DOX activated innate immunity and coordinated adaptive immunity, enhancing immunotherapy efficacy. In vivo experiments have demonstrated that DOX/R837@ManL effectively eliminated primary tumors and lung metastases, while also preventing tumor recurrence post-surgery. These findings highlighted the potential of DOX/R837@ManL as a promising strategy for cancer immunotherapy.

Rare urachal mucinous cystic tumor of low malignant potential with peritoneal pseudomyxoma: A case report.

Mucinous cystic tumors of low malignant potential (MCTLMP) are rare urachal neoplasms. The morphological characteristics and clinical prognosis of MCTLMP is similar to that of mucinous cystic tumors occurring in the ovary and appendix. After complete resection, almost no cases of recurrence or metastasis have been reported. Because MCTLMP is rare, it may be missed in the clinic. MCTLMP can lead to the formation of pseudomyxoma peritonei (PMP), which manifests as the widespread production of mucus in the abdominal cavity and makes the disease complex or difficult to diagnose. At present, only 3 cases of MCTLMP with PMP have been reported in the literature. In the present study a fourth case of urachal MCTLMP in a 74-year-old male that resulted in widespread PMP is presented. Initially, a multilocular cystic lesion was revealed in the urachal duct area at the anterior upper margin of the bladder after a patient, experiencing lower abdominal pain, was imaged. As revealed using light microscopy, the cyst was lined with a mucous columnar epithelium, and part of the epithelium indicated pseudolamellar hyperplasia and papillary structures. The cells indicated mild atypia and low mitotic activity. There was no stromal infiltration of tumor cells, and a large amount of mucous exudate was observed. As preoperative computed tomography examination suggested the presence of a large amount of ascites and there were increased levels of blood tumor markers, carcinoembryonic antigen and carbohydrate antigen 125, clinicians considered that the diagnosis maybe a malignant tumor of the urachal gland with peripheral dissemination. However, the diagnosis of MCTLMP with PMP was confirmed by histopathological examination. The mass was completely removed, along with part of the peritoneum and bladder wall as these were within the tumor margin. The appendix appeared normal during surgery. A one off dose of intraperitoneal infusion chemotherapy with 1,000 mg 5-fluorouracil was performed after surgery. No recurrence was observed during the 8-month follow-up period.

SMARCA4­deficient non­small cell lung cancer with an EGFR mutation: A case report.

SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4 (SMARCA4)-deficient non-small cell lung cancer (dNSCLC) is a rare malignant tumor that originates in the lungs. It occurs more frequently in male smokers, and the epidermal growth factor receptor (EGFR) gene is often mutation-free. In the present study, the case of a 60-year-old, non-smoking female patient diagnosed with SMARCA4-dNSCLC is reported. Biopsy of the tumor showed solid flaky, nest-like infiltrating growth. Immunohistochemistry revealed the following: SMARCA4/BRG1(-), SMARCB1/INI-1(+), cytokeratin7 (+), cytokeratin 5.2 (+), CK5/6(+) and calretinin(+). The Ki-67 positivity index was 75%, and the thyroid transcription factor-1, NapsinA, p40, nuclear protein in testis, CD34, Sal-like protein 4, SRY-box transcription factor 2 and synaptophysin were negative. Molecular analysis showed mutations in both EGFR and TP53. The pathological diagnosis was SMARCA4-dNSCLC with an EGFR gene mutation. The present case report could be used for broadening the pathological diagnosis of SMARCA4-dNSCLC and for selecting appropriate treatment approaches.

An effective antimicrobial strategy of colistin combined with the Chinese herbal medicine shikonin against colistin-resistant Escherichia coli.

IMPORTANCE: Infections caused by multidrug-resistant Escherichia coli (MDR E. coli) have become a major global healthcare problem due to the lack of effective antibiotics today. The emergence of colistin-resistant E. coli strains makes the situation even worse. Therefore, new antimicrobial strategies are urgently needed to combat colistin-resistant E. coli. Combining traditional antibiotics with non-antibacterial drugs has proved to be an effective approach of combating MDR bacteria. This study investigated the combination of colistin and shikonin, a Chinese herbal medicine, against colistin-resistant E. coli. This combination showed good synergistic antibacterial both in vivo and in vitro experiments. Under the background of daily increasing colistin resistance in E. coli, this research points to an effective antimicrobial strategy of using colistin and shikonin in combination against colistin-resistant E. coli.

Study of Combined Effect of Bacteriophage vB3530 and Chlorhexidine on the Inactivation of Pseudomonas aeruginosa.

BACKGROUND: Chlorhexidine (CHG) is a disinfectant commonly used in hospitals. However, it has been reported that the excessive use of CHG can cause resistance in bacteria to this agent and even to other clinical antibiotics. Therefore, new methods are needed to alleviate the development of CHG tolerance and reduce its dosage. This study aimed to explore the synergistic effects of CHG in combination with bacteriophage against CHG-tolerant Pseudomonas aeruginosa (P. aeruginosa) and provide ideas for optimizing disinfection strategies in clinical environments as well as for the efficient use of disinfectants. METHODS: The CHG-tolerant P. aeruginosa strains were isolated from the First Affiliated Hospital of Wenzhou Medical University in China. The bacteriophage vB3530 was isolated from the sewage inlet of the hospital, and its genome was sequenced. Time-killing curve was used to determine the antibacterial effects of vB3530 and chlorohexidine gluconate (CHG). The phage sensitivity to 16 CHG-tolerant P. aeruginosa strains and PAO1 strain was detected using plaque assay. The emergence rate of resistant bacterial strains was detected to determine the development of phage-resistant and CHG-tolerant strains. Finally, the disinfection effects of the disinfectant and phage combination on the surface of the medical devices were preliminarily evaluated. RESULTS: The results showed that (1) CHG combined with bacteriophage vB3530 significantly inhibited the growth of CHG-resistant P. aeruginosa and reduced the bacterial colony forming units (CFUs) after 24 h. (2) The combination of CHG and bacteriophage inhibited the emergence of phage-resistant and CHG-tolerant strains. (3) The combination of CHG and bacteriophage significantly reduced the bacterial load on the surface of medical devices. CONCLUSIONS: In this study, the combination of bacteriophage vB3530 and CHG presented a combined inactivation effect to CHG-tolerant P. aeruginosa and reduced the emergence of strains resistant to CHG and phage. This study demonstrated the potential of bacteriophage as adjuvants to traditional disinfectants. The use of bacteriophage in combination with commercial disinfectants might be a promising method for controlling the spread of bacteria in hospitals.

Phage resistance formation and fitness costs of hypervirulent Klebsiella pneumoniae mediated by K2 capsule-specific phage and the corresponding mechanisms.

Introduction: Phage is promising for the treatment of hypervirulent Klebsiella pneumoniae (hvKP) infections. Although phage resistance seems inevitable, we found that there still was optimization space in phage therapy for hvKP infection. Methods: The clinical isolate K. pneumoniae FK1979 was used to recover the lysis phage ΦFK1979 from hospital sewage. Phage-resistant bacteria were obtained on LB agar and used to isolate phages from sewage. The plaque assay, transmission electron microscopy (TEM), multiplicity of infection test, one-step growth curve assay, and genome analysis were performed to characterize the phages. Colony morphology, precipitation test and scanning electron microscope were used to characterize the bacteria. The absorption test, spot test and efficiency of plating (EOP) assay were used to identify the sensitivity of bacteria to phages. Whole genome sequencing (WGS) was used to identify gene mutations of phage-resistant bacteria. The gene expression levels were detected by RT-qPCR. Genes knockout and complementation of the mutant genes were performed. The change of capsules was detected by capsule quantification and TEM. The growth kinetics, serum resistance, biofilm formation, adhesion and invasion to A549 and RAW 264.7 cells, as well as G. mellonella and mice infection models, were used to evaluate the fitness and virulence of bacteria. Results and discussion: Here, we demonstrated that K2 capsule type sequence type 86 hvKP FK1979, one of the main pandemic lineages of hvKP with thick capsule, rapidly developed resistance to a K2-specific lysis phage ΦFK1979 which was well-studied in this work to possess polysaccharide depolymerase. The phage-resistant mutants showed a marked decrease in capsule expression. WGS revealed single nucleotide polymorphism (SNP) in genes encoding RfaH, galU, sugar glycosyltransferase, and polysaccharide deacetylase family protein in the mutants. RfaH and galU were further identified as being required for capsule production and phage sensitivity. Expressions of genes involved in the biosynthesis or regulation of capsule and/or lipopolysaccharide significantly decreased in the mutants. Despite the rapid and frequent development of phage resistance being a disadvantage, the attenuation of virulence and fitness in vitro and in vivo indicated that phage-resistant mutants of hvKP were more susceptible to the immunity system. Interestingly, the newly isolated phages targeting mutants changed significantly in their plaque and virus particle morphology. Their genomes were much larger than and significantly different from that of ΦFK1979. They possessed much more functional proteins and strikingly broader host spectrums than ΦFK1979. Our study suggests that K2-specific phage has the potential to function as an antivirulence agent, or a part of phage cocktails combined with phages targeting phage-resistant bacteria, against hvKP-relevant infections.

Deep convolutional neural networks for multiple histologic types of ovarian tumors classification in ultrasound images.

Objective: This study aimed to evaluate and validate the performance of deep convolutional neural networks when discriminating different histologic types of ovarian tumor in ultrasound (US) images. Material and methods: Our retrospective study took 1142 US images from 328 patients from January 2019 to June 2021. Two tasks were proposed based on US images. Task 1 was to classify benign and high-grade serous carcinoma in original ovarian tumor US images, in which benign ovarian tumor was divided into six classes: mature cystic teratoma, endometriotic cyst, serous cystadenoma, granulosa-theca cell tumor, mucinous cystadenoma and simple cyst. The US images in task 2 were segmented. Deep convolutional neural networks (DCNN) were applied to classify different types of ovarian tumors in detail. We used transfer learning on six pre-trained DCNNs: VGG16, GoogleNet, ResNet34, ResNext50, DensNet121 and DensNet201. Several metrics were adopted to assess the model performance: accuracy, sensitivity, specificity, FI-score and the area under the receiver operating characteristic curve (AUC). Results: The DCNN performed better in labeled US images than in original US images. The best predictive performance came from the ResNext50 model. The model had an overall accuracy of 0.952 for in directly classifying the seven histologic types of ovarian tumors. It achieved a sensitivity of 90% and a specificity of 99.2% for high-grade serous carcinoma, and a sensitivity of over 90% and a specificity of over 95% in most benign pathological categories. Conclusion: DCNN is a promising technique for classifying different histologic types of ovarian tumors in US images, and provide valuable computer-aided information.

Pleomorphic undifferentiated sarcoma of the mediastinal thymus: A case report and literature review.

Pleomorphic undifferentiated sarcoma (PUS) of the mediastinal thymus is a rare type of cancer. In the present case report, a 67-year-old female patient presenting a mediastinal mass for >1 year was assessed for clinical characteristics, histopathological, immunohistochemical expression and gene mutation using fluorescence in situ hybridization (FISH), and relevant literature was reviewed. Histological analysis revealed nodular changes of different sizes in the thymus, which consisted of a mixture of pleomorphic and spindle cells. The pleomorphic cells with distinct atypia were giant cells and multinucleated cells with large cell sizes and frequent nuclear divisions. The spindle cells were mild to moderate atypical and arranged in a woven pattern, and nuclear division was rare. Immunohistochemical analysis indicated that vimentin was diffusively expressed in tumor cells. No amplification was found in CDX2 and MDM4 genes using the FISH analysis. In conclusion, mediastinal thymus neoplasm should be considered in the presence of PUS and it is an exclusionary diagnosis based on clinical and pathological examination of the patient.

Ceftazidime-Decorated Gold Nanoparticles: a Promising Strategy against Clinical Ceftazidime-Avibactam-Resistant Enterobacteriaceae with Different Resistance Mechanisms.

Nanoparticle-based antibiotic delivery systems are essential in combating antibiotic-resistant bacterial infections arising from acquired resistance and/or biofilm formation. Here, we report that the ceftazidime-decorated gold nanoparticles (CAZ_Au NPs) can effectively kill clinical ceftazidime-avibactam-resistant Enterobacteriaceae with various resistance mechanisms. Further study of underlying antibacterial mechanisms suggests that CAZ_Au NPs can damage the bacterial cell membrane and increase the level of intracellular reactive oxygen species. Moreover, CAZ_Au NPs show great potential in inhibiting biofilm formation and eradicating mature biofilms via crystal violet and scanning electron microscope assays. In addition, CAZ_Au NPs demonstrate excellent performance in improving the survival rate in the mouse model of abdominal infection. In addition, CAZ_Au NPs show no significant toxicity at bactericidal concentrations in the cell viability assay. Thus, this strategy provides a simple way to drastically improve the potency of ceftazidime as an antibiotic and its use in further biomedical applications.

Impacts of unifying urban and rural residents' medical insurance on the hospitalisation expenses of rural patients in eastern China: an interrupted time series analysis.

OBJECTIVES: This study evaluated the impact of the Urban and Rural Residents' Basic Medical Insurance scheme on hospitalisation expenses of rural patients in eastern China, which unified separate healthcare systems for urban and rural residents. DESIGN: Monthly hospitalisation data from municipal and county hospitals were collected from the local Medicare Fund Database, covering the period from January 2018 to December 2021. The unification of insurance between urban and rural patients was implemented at different times for county and municipal hospitals. An interrupted time series analysis was used to assess the immediate and gradual effects of the integrated policy on the total medical expenses, out-of-pocket (OOP) expenses and effective reimbursement rate (ERR) among rural patients. SETTING AND PARTICIPANTS: This study included 636 155 rural inpatients over 4 years in Xuzhou City, Jiangsu Province, China. RESULTS: In January 2020, the policy of urban and rural medical insurance was initially integrated in county hospitals, after which the ERR decreased at a monthly rate of 0.23% (p=0.002, 95% CI -0.37% to -0.09%) compared with the preintervention period. After the insurance systems were unified in municipal hospitals in January 2021, OOP expenses decreased by ¥63.54 (p=0.002, 95% CI -102.48 to -24.61) and the ERR increased at a monthly rate of 0.24% (p=0.029, 95% CI 0.03% to 0.045%). CONCLUSIONS: Our results suggest that the unification of urban and rural medical insurance systems was an effective intervention to reduce the financial burden of illness for rural inpatients, especially OOP expenses for hospitalisation in municipal hospitals.

Thymol-Decorated Gold Nanoparticles for Curing Clinical Infections Caused by Bacteria Resistant to Last-Resort Antibiotics.

Multidrug-resistant bacteria pose a tremendous challenge to public health worldwide. Many bacteria resistant to last-resort antibiotics due to antibiotic misuse have been recently reported, which may give rise to serious infections without effective treatment. Therefore, it is imperative to develop novel antimicrobial strategies. Natural phenols are known to increase bacterial membrane permeability and are potential candidates for the development of new antimicrobial agents. In this study, gold nanoparticles (Au NPs) carrying natural phenols were synthesized to combat bacteria resistant to last-resort antibiotics. Transmission electron microscopy, dynamic light scattering, zeta potential, and UV-visible spectra were used to characterize the synthesized Au NPs, which showed good monodispersity and uniform particle size. Evaluation of antibacterial activity using the broth microdilution method revealed that thymol-decorated gold nanoparticles (Thymol_Au NPs) had a broad antibacterial spectrum and higher bactericidal effects than last-resort antibiotics against last-resort-antibiotic-resistant bacteria. Considering the underlying antibacterial mechanism, the results showed that Thymol_Au NPs destroyed bacterial cell membranes. Further, Thymol_Au NPs were effective in treating mouse abdominal infections and exhibited acceptable biocompatibility without any significant toxicity in cell viability and histopathological assays, respectively, at most bactericidal concentrations. However, attention should be paid to changes in white blood cells, reticulocyte percentages, and superoxide dismutase activity during Thymol_Au NP treatment. In conclusion, Thymol_Au NPs have the potential for treating clinical infections caused by bacteria resistant to last-resort antibiotics. IMPORTANCE Excessive use of antibiotics can lead to bacterial resistance and the development of multidrug-resistant bacteria. Antibiotic misuse can also promote resistance against last-resort antibiotics. It is thus crucial to develop alternatives to antibiotics to retard the development of multidrug resistance. In recent years, the use of several nanodosage forms of antibacterial drugs has been investigated. These agents kill bacteria through a variety of mechanisms and avoid the problem of resistance. Among them, Au NPs, which are safer to use for medical applications than other metal nanoparticles, have attracted interest as potential antibacterial agents. To combat bacterial resistance to last-resort antibiotics and mitigate the problem of antimicrobial resistance, it is important and meaningful to develop antimicrobial agents based on Au NPs.

Bacterial outer membrane vesicles-cloaked modified zein nanoparticles for oral delivery of paclitaxel.

To improve the aqueous solubility and oral bioavailability of paclitaxel (PTX), a biomimetic system for oral administration of PTX was efficiently developed as an outer membrane vesicle (OMVs) of sodium caseinate (CAS) modified zein nanoparticles (OMVs-Zein-CAS-PTX-NPs) by Escherichia coli. To verify their structure and properties, the designed nanostructures were thoroughly characterized using various characterization techniques. The results indicated that hydrogen bonds and van der Waals forces mainly drove the interaction between PTX and Zein, but the complex is unstable. The physicochemical stability of PTX-loaded zein nanoparticles was improved by the addition of CAS. The biological characteristics of biofilms are reproduced by nanoparticles cloaked with outer membrane vesicles. OMVs-Zein-CAS-PTX-NPs delayed the release of PTX under simulated gastric and intestinal fluids due to OMVs protection. OMVs-Zein-CAS-PTX-NPs exhibited remarkable antitumor ability in vitro and improved the bioavailability of oral administration of PTX in vivo. Therefore, OMVs cloaked in nanoparticles may be a suitable delivery vehicle to provide an efficient application prospect for the oral administration of PTX.

Flufenamic Acid, a Promising Agent for the Sensitization of Colistin-Resistant Gram-Negative Bacteria to Colistin.

The continuous development of multidrug-resistant (MDR) Gram-negative bacteria poses a serious risk to public health on a worldwide scale. Colistin is used as the last-line antibiotic for the treatment of MDR pathogens, and colistin-resistant (COL-R) bacterial emergence thus has the potential to have a severe adverse impact on patient outcomes. In this study, synergistic activity was observed when colistin and flufenamic acid (FFA) were combined and used for the in vitro treatment of clinical COL-R Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii strains, as shown by checkerboard and time-kill assays. Crystal violet staining and scanning electron microscopy revealed the synergistic action of colistin-FFA against biofilms. When used to treat murine RAW264.7 macrophages, this combination did not induce any adverse toxicity. Strikingly, the survival rates of bacterially infected Galleria mellonella larvae were improved by such combination treatment, which was also sufficient to reduce the measured bacterial loads in a murine thigh infection model. Mechanistic propidium iodide (PI) staining analysis further demonstrated the ability of these agents to alter bacterial permeability in a manner that enhanced the efficacy of colistin treatment. Together, these data thus demonstrate that colistin and FFA can be synergistically combined to combat the spread of COL-R Gram-negative bacteria, providing a promising therapeutic tool with the potential to protect against COL-R bacterial infections and improve patient outcomes. IMPORTANCE Colistin is a last-line antibiotic used for the treatment of MDR Gram-negative bacterial infections. However, increasing resistance to it has been observed during clinical treatment. In this work, we assessed the efficacy of the combination of colistin and FFA for the treatment of COL-R bacterial isolates, demonstrating that the combined treatment has effective antibacterial and antibiofilm activities. Due to its low cytotoxicity and good therapeutic effects in vitro, the colistin-FFA combination may be a potential candidate for research into a resistance-modifying agent to combat infections caused by COL-R Gram-negative bacteria.

A Novel CCK Receptor GPR173 Mediates Potentiation of GABAergic Inhibition.

Cholecystokinin (CCK) enables excitatory circuit long-term potentiation (LTP). Here, we investigated its involvement in the enhancement of inhibitory synapses. Activation of GABA neurons suppressed neuronal responses in the neocortex to a forthcoming auditory stimulus in mice of both sexes. High-frequency laser stimulation (HFLS) of GABAergic neurons potentiated this suppression. HFLS of CCK interneurons could induce the LTP of their inhibition toward pyramidal neurons. This potentiation was abolished in CCK knock-out mice but intact in mice with both CCK1R and 2R knockout of both sexes. Next, we combined bioinformatics analysis, multiple unbiased cell-based assays, and histology examinations to identify a novel CCK receptor, GPR173. We propose GPR173 as CCK3R, which mediates the relationship between cortical CCK interneuron signaling and inhibitory LTP in the mice of either sex. Thus, GPR173 might represent a promising therapeutic target for brain disorders related to excitation and inhibition imbalance in the cortex.SIGNIFICANCE STATEMENT CCK, the most abundant and widely distributed neuropeptide in the CNS, colocalizes with many neurotransmitters and modulators. GABA is one of the important inhibitory neurotransmitters, and much evidence shows that CCK may be involved in modulating GABA signaling in many brain areas. However, the role of CCK-GABA neurons in the cortical microcircuits is still unclear. We identified a novel CCK receptor, GPR173, localized in the CCK-GABA synapses and mediated the enhancement of the GABA inhibition effect, which might represent a promising therapeutic target for brain disorders related to excitation and inhibition imbalance in the cortex.

Improving the Segmentation Accuracy of Ovarian-Tumor Ultrasound Images Using Image Inpainting.

Diagnostic results can be radically influenced by the quality of 2D ovarian-tumor ultrasound images. However, clinically processed 2D ovarian-tumor ultrasound images contain many artificially recognized symbols, such as fingers, crosses, dashed lines, and letters which assist artificial intelligence (AI) in image recognition. These symbols are widely distributed within the lesion's boundary, which can also affect the useful feature-extraction-utilizing networks and thus decrease the accuracy of lesion classification and segmentation. Image inpainting techniques are used for noise and object elimination from images. To solve this problem, we observed the MMOTU dataset and built a 2D ovarian-tumor ultrasound image inpainting dataset by finely annotating the various symbols in the images. A novel framework called mask-guided generative adversarial network (MGGAN) is presented in this paper for 2D ovarian-tumor ultrasound images to remove various symbols from the images. The MGGAN performs to a high standard in corrupted regions by using an attention mechanism in the generator to pay more attention to valid information and ignore symbol information, making lesion boundaries more realistic. Moreover, fast Fourier convolutions (FFCs) and residual networks are used to increase the global field of perception; thus, our model can be applied to high-resolution ultrasound images. The greatest benefit of this algorithm is that it achieves pixel-level inpainting of distorted regions without clean images. Compared with other models, our model achieveed better results with only one stage in terms of objective and subjective evaluations. Our model obtained the best results for 256 × 256 and 512 × 512 resolutions. At a resolution of 256 × 256, our model achieved 0.9246 for SSIM, 22.66 for FID, and 0.07806 for LPIPS. At a resolution of 512 × 512, our model achieved 0.9208 for SSIM, 25.52 for FID, and 0.08300 for LPIPS. Our method can considerably improve the accuracy of computerized ovarian tumor diagnosis. The segmentation accuracy was improved from 71.51% to 76.06% for the Unet model and from 61.13% to 66.65% for the PSPnet model in clean images.