Rapid Detection of Bacterial Resistance to ß-Lactam Antibiotics with a Relay-Response Chemiluminescence Assay.

Bacterial resistance caused by ß-lactamases has been a major threat to public health around the world, seriously weakening the efficacy of ß-lactam antibiotics, the most widely used therapeutic agents against infectious diseases. To detect the bacterial resistance to ß-lactam antibiotics, particularly specific type of ß-lactam antibiotics, in a rapid manner, we report herein a relay-response chemiluminescence assay. This assay mainly consists of two reagents: a ß-lactam-caged thiophenol and a thiophenol-sensitive chemiluminescence reporter, both of which are synthetically feasible. The selective hydrolysis of ß-lactam by ß-lactamase leads to the releasing of free thiophenol, which then triggers the emission of a chemiluminescence signal in a relay manner. Three thiophenol-caged ß-lactams, structural analogues of cephalothin, cefotaxime, and meropenem, respectively, have been synthesized. And the application of this assay with these analogues of ß-lactam antibiotics allows fast detection of ß-lactamase-expressing resistant bacteria and, more impressively, provides detailed information on the resistant scope of bacteria.

Gut microbiota facilitate chronic spontaneous urticaria.

Chronic spontaneous urticaria (CSU) comes with gut dysbiosis, but its relevance remains elusive. Here we use metagenomics sequencing and short-chain fatty acids metabolomics and assess the effects of human CSU fecal microbial transplantation, Klebsiella pneumoniae, Roseburia hominis, and metabolites in vivo. CSU gut microbiota displays low diversity and short-chain fatty acids production, but high gut Klebsiella pneumoniae levels, negatively correlates with blood short-chain fatty acids levels and links to high disease activity. Blood lipopolysaccharide levels are elevated, link to rapid disease relapse, and high gut levels of conditional pathogenic bacteria. CSU microbiome transfer and Klebsiella pneumoniae transplantation facilitate IgE-mediated mast cell(MC)-driven skin inflammatory responses and increase intestinal permeability and blood lipopolysaccharide accumulation in recipient mice. Transplantation of Roseburia hominis and caproate administration protect recipient mice from MC-driven skin inflammation. Here, we show gut microbiome alterations, in CSU, may reduce short-chain fatty acids and increase lipopolysaccharide levels, respectively, and facilitate MC-driven skin inflammation.

The hub genes and their potential regulatory mechanisms in chronic spontaneous urticaria revealed by integrated transcriptional expression analysis.

Chronic spontaneous urticaria (CSU) is a recurrent disease characterized by wheals and or angioedema, and its pathogenesis is still unclear. The microarray datasets of skin tissue from CSU patients and healthy controls were integrated and analysed in Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were identified using the NetworkAnalyst tool. Then, the Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. Subsequently, a protein-protein interaction (PPI) network of DEGs was constructed by STRING and the related hub genes were identified through the MOCDE tool. The potential miRNAs targeting hub genes were predicted based on the intersection of three online databases, namely TargetScanHuman, TargetBase and miRNet. Differentially expressed lncRNAs (DElncRNAs) was performed using the GEO2R tool. The potential miRNAs targeting DElncRNAs were predicted through miRNet. Finally, the shared miRNAs targeting both hub genes and DElncRNAs were used to construct an mRNA/miRNA/lncRNA regulatory network. A total of 296 DEGs were obtained, which were mainly enriched in inflammatory and immune responses. Further, 14 hub genes were identified by the PPI network of DEGs. Clinical correlation analysis showed that the mRNA expressions of S100A7, S100A8, S100A9, S100A12, IL6 and SOCS3 in CSU were positively correlated with the 7-day urticaria activity score (UAS7), and their potential diagnostic value was supported by the receiver operating characteristic curve (ROC) analysis. Five up-regulated lncRNAs in the cytoplasm were obtained by DElncRNAs analysis. The ROC analysis showed that PVT1, SNHG3 and ZBTB20 - AS1 was of potential diagnostic value for CSU. Eight shared miRNAs targeting both hub genes and DElncRNAs were identified and used to construct a competing endogenous RNA (ceRNA) network. It was found that the IL-6/miR - 149 - 5p/ZBTB20 - AS1 axis might play an important role in the activation of mast cells in CSU. IL-6 and its related regulatory molecules may be used as potential diagnostic markers and therapeutic targets for CSU.

Integrative lipidomic features identify plasma lipid signatures in chronic urticaria.

Chronic urticaria (CU) is a chronic inflammatory skin disease mainly mediated by mast cells. Lipids exert essential functions in biological processes; however, the role of lipids in CU remains unclear. Nontargeted lipidomics was performed to investigate the differential lipid profiles between CU patients and healthy control (HC) subjects. Functional validation studies were performed in vitro and in vivo including ß-hexosaminidase release examination from mast cells and passive cutaneous anaphylaxis (PCA) mouse model. We detected dramatically altered glycerophospholipids in CU patients compared with HCs. Phosphatidylserine (PS), phosphatidylethanolamine (PE), and phosphatidylglycerol (PG) were increased, while phosphatidylcholine (PC) was reduced in CU patients. The reduction in PC was related to a high weekly urticaria activity score (UAS7), while PS was positively associated with the dermatology life quality index (DLQI). We also identified the differential lipid profiles between chronic spontaneous urticaria (CSU), symptomatic dermographism (SD), and CSU coexist with SD. CU patients were classified into two subtypes (subtype 1 and subtype 2) based on consensus clustering of lipid profiling. Compared with patients in subtype 2, patients in subtype 1 had elevated levels of PC (18:0e/18:2) and PE (38:2), and lower urticaria control test (UCT) scores indicated worse clinical efficiency of secondary generation H1 antihistamines treatment. Importantly, we found that supplementation with PC could attenuate IgE-induced immune responses in mast cells. In general, We described the landscape of plasma lipid alterations in CU patients and provided novel insights into the role of PC in mast cells.

The Role of Crosstalk of Immune Cells in Pathogenesis of Chronic Spontaneous Urticaria.

Chronic spontaneous urticaria (CSU) is defined as recurrent episodes of spontaneous wheal development and/or angioedema for more than six weeks and at least twice a week. The core link in the pathogenesis of CSU is the activation of mast cells, T cells, eosinophils, and other immune cells infiltrating around the small venules of the lesion. Increased vascular permeability, vasodilatation, and recruitment of inflammatory cells directly depend on mast cell mediators' release. Complex regulatory systems tightly influence the critical roles of mast cells in the local microenvironment. The bias toward Th2 inflammation and autoantibodies derived from B cells, histamine expressed by basophils, and initiation of the extrinsic coagulation pathway by eosinophils or monocytes exerts powerful modulatory influences on mast cells. Cell-to-cell interactions between mast cells and eosinophils/T cells also are regulators of their function and may involve CSU's pathomechanism. This review summarizes up-to-date knowledge regarding the crosstalk between mast cells and other immune cells, providing the impetus to develop new research concepts and treatment strategies for CSU.

Pharmacogenomics for the efficacy and side effects of antihistamines.

Antihistamines, especially H1 antihistamines, are widely used in the treatment of allergic diseases such as urticaria and allergic rhinitis, mainly for reversing elevated histamine and anti-allergic effects. Antihistamines are generally safe, but some patients experience adverse reactions, such as cardiotoxicity, central inhibition and anticholinergic effects. There are also individual differences in antihistamine efficacy in clinical practice. The concept of individualized medicine has been deeply rooted in people's minds since it was put forward. Pharmacogenomics is the study of the role of inheritance in individual variations in drug response. In recent decades, pharmacogenomics has been developing rapidly, which provides new ideas for individualized medicine. Polymorphisms in the genes encoding metabolic enzymes, transporters and target receptors have been shown to affect the efficacy of antihistamines. In addition, recent evidence suggests that gene polymorphisms influence urticaria susceptibility and antihistamine therapy. Here, we summarize current reports in this area, aiming to contribute to future research in antihistamines and clinical guidance for antihistamines use in individualized medicine.

Efficacy and Safety of Dupilumab in Chinese Patients With Atopic Dermatitis: A Real-World Study.

Background: Atopic dermatitis (AD) is a common skin disease, but treatment of this disease has been challenging. Dupilumab is a new biological agent for AD that has been proven to be safe and effective in clinical trials. Although dupilumab was approved for listing in China in June 2020, real-world data about the application of dupilumab in China are lacking. This study aimed to collect and analyze real-world data on dupilumab among Chinese AD patients. Methods: Demographic and clinical data for 116 AD patients receiving dupilumab treatment were reviewed. The Eczema Area and Severity Index (EASI), SCORing Atopic Dermatitis (SCORAD), Numerical Rating Scale (NRS), Patient Oriented Eczema Measure (POEM), and Dermatology Quality of Life Index (DLQI) of patients were evaluated every 2 weeks from baseline to 16 weeks of treatment. Any adverse events during treatment were recorded. Results: Among the 116 patients in this study, baseline levels of IgE, eosinophils, and LDH were elevated in 62.79% (n = 86), 45.30% (n = 86), and 54.20% of patients (n = 48), respectively. The SCORAD index and POEM, DLQI, and NRS scores were significantly improved in all patients at 2 weeks (p < 0.0001), 4 weeks (p < 0.01), and 16 weeks (p < 0.001). EASI scores also improved significantly in all patients at 2 weeks (p < 0.01), 4 weeks (> 0.05), and 16 weeks (p < 0.01). However, 11 patients (9.48%) had no response. IgE and LDH levels (p > 0.05), Eosinophil counts (p < 0.01) in blood increased temporarily in the first 4 weeks and then decreased and stabilized during dupilumab treatment. Conjunctivitis was the most common adverse event (2.59%) among the patients. We found that the curative efficacy of dupilumab at 4th weeks was related to the patient's age and course of disease. Nevertheless, there is no relationship between levels of eosinophils, IgE, LDH and the therapeutic efficacy of dupilumab. Conclusion: The real-world data in China showed that dupilumab can effectively treat AD and is well tolerated with a low incidence of adverse events.

Stereochemically altered cephalosporins as potent inhibitors of New Delhi metallo-ß-lactamases.

Antibiotic resistance caused by ß-lactamases, particularly metallo-ß-lactamases, has been a major threat to public health globally. New Delhi metallo-ß-lactamase-1 (NDM-1) represents one of the most important metallo-ß-lactamases; the production of NDM-1 in bacterial pathogen significantly reduces the efficacy of ß-lactam antibiotics, including life-saving carbapenems. Herein, we have demonstrated stereochemically altered cephalosporins as potent inhibitors against NDM-1, as well as mutants of NDM. The structure and activity relationship (SAR) study on over twenty cephalosporin analogues discloses the stereochemistry and the substituents on 7-position and 3'-position of cephalosporin are critical to suppress the activity of NDM-1 and the optimal compound 1u exhibited an IC50 of 0.13 µM. Furthermore, a crystal complex of NDM-1 and 1u has been obtained, suggesting this cephalosporin derivative inhibits enzyme activity by the formation of a relatively stable hydrolytic product-NDM-1 intermediate. The discovery in this study may pave the way to turn cephalosporin, a natural substrate of ß-lactamase, into an effective NDM-1 inhibitor to combat antibiotic resistance.

Lachnospira is a signature of antihistamine efficacy in chronic spontaneous urticaria.

Chronic spontaneous urticaria (CSU) is a mast cell-driven disease with many advances in its aetiology and pathogenesis over the past years. The main treatment of CSU is oral second-generation antihistamines. However, only an average of 50% of CSU patients responded adequately to conventional or quadruple doses of non-sedative antihistamines. Meanwhile, gut microbiota can affect the efficacy of drugs. The purpose of this study was to investigate the relationship between gut microbiota and the efficacy of antihistamines in patients with CSU. The patients with CSU were divided into responders and non-responders according to the efficacy of antihistamine monotherapy. The gut microbiota of faecal samples from 15 responders and 15 non-responders was detected by 16S rDNA sequencing, and the differential bacterial species between the two groups were verified by quantitative polymerase chain reaction (qPCR). Additional faecal samples from 30 responders and 30 non-responders were used as an extended cohort to further verify the above differential bacterial species by qPCR. Lachnospiraceae and its subordinate taxa were found to be the main differences in gut microbiota between responders and non-responders. The abundance of Lachnospira in responders was higher than that in non-responders. Lachnospira exhibits moderate diagnostic value in evaluating the efficacy of antihistamine. Lachnospira is a signature for predicting the efficacy of antihistamine in patients with CSU.

Biomarkers of Gut Microbiota in Chronic Spontaneous Urticaria and Symptomatic Dermographism.

Background: Chronic urticaria (CU) is a chronic inflammatory skin disease associated with Th2 immune response. The two most common subtypes of CU, i.e., chronic spontaneous urticaria and symptomatic dermographism (CSD), often coexist. However, the pathogenesis of CSD is still unclear. Gut microbiota plays an important role in immune-related inflammatory diseases. The purpose of this study was to explore the correlation between gut microbiota and CSD. Methods: A case-control study was conducted on CSD patients as well as gender- and age-matched normal controls (NCs). The 16S ribosomal DNA sequencing of fecal samples was used to detect the gut microbiota of all subjects. QPCR was used to further verify the species with differences between the two groups. Results: The alpha diversity of gut microbiota decreased in CSD patients, accompanied by significant changes of the structure of gut microbiota. Subdoligranulum and Ruminococcus bromii decreased significantly in CSD patients and had a potential diagnostic value for CSD according to receiver operating characteristic curve (ROC) analysis. Enterobacteriaceae and Klebsiella were found to be positively correlated with the duration of CSD, while Clostridium disporicum was positively correlated with the dermatology life quality index (DLQI). Conclusions: The gut microbiota of CSD patients is imbalanced. Subdoligranulum and Ruminococcus bromii are the gut microbiota biomarkers in CSD.

Specific detection of IMP-1 ß-lactamase activity using a trans cephalosporin-based fluorogenic probe.

A fluorogenic probe for the specific detection of IMP-1 ß-lactamase activity has been developed. This imaging reagent features a unique trans-acetylamino cephalosporin as an enzymatic recognition moiety, exhibiting excellent selectivity to IMP-1 ß-lactamase over other ß-lactamases, including serine- and metallo-ß-lactamases. The selective activation of the probe by IMP-1 ß-lactamase leads to over 30-fold enhancement in the fluorescence intensity, which allows enzyme activity to be reported with high sensitivity.

Identification of gut microbiota signatures in symptomatic dermographism.

Symptomatic dermographism (SD) is a recurrent inflammatory skin disease related to immunity; however, the details remain elusive. In view of the important role of gut microbiota in immune regulation, the purpose of this study is to investigate the alterations of gut microbiota in SD and explore the potential bacterial biomarkers for diagnosis. A case-control study including SD patients and normal controls (NCs) was carried out. Gut microbiota of the participants was analysed by the 16S rDNA sequencing of faecal samples. The linear discriminant analysis effect size and the receiver operating characteristic curve (ROC) analysis were used to identify the bacterial biomarkers. Forty-four participants were included in this study. The alpha-diversity and beta-diversity of gut microbiota differed significantly between SD patients and NCs. The abundance of Verrucomicrobia, Ruminococcaceae and their subordinate taxa were reduced in SD patients, while Enterobacteriales and its subordinate taxon exhibited higher relative abundance compared with NCs. Subdoligranulum and Ruminococcus bromii showed a potential diagnostic value for SD, and Prevotella stercorea was negatively relevant to duration of SD. Furthermore, the pyruvate, butyric acid and histamine metabolism pathway were likely to be involved in the pathogenesis of SD. Our results revealed that the gut microbiota of SD patients experienced obvious changes, and Verrucomicrobia, Ruminococcaceae and Enterobacteriales were microbiota signatures for SD.

Therapeutic effect of Bacillus Calmette-Guerin polysaccharide nucleic acid on mast cell at the transcriptional level.

BACKGROUND: Chronic spontaneous urticaria (CSU) is a common and recurrent autoimmune-related disease with unclear pathogenesis. Dysfunction of immune cells, such as T cells, mast cells, and basophils, is involved. Bacillus Calmette-Guerin polysaccharide nucleic acid (BCG-PSN), an immunomodulator partially extracted from BCG, can be used in the combined treatment of CSU with an unknown mechanism. METHODS: To study the therapeutic effect and mechanism of BCG-PSN on CSU, we initially assessed the clinical efficacy in 110 enrolled CSU patients of 4-week antihistamine monotherapy vs. antihistamine plus BCG-PSN combined therapy. Subsequently, to explore the further mechanism of BCG-PSN, the mast cell line RBL-2H3 pretreated with BCG-PSN was used to evaluate the transcriptional expression profiles via lncRNA sequencing. Real time PCR was conducted to validate the candidate gene expression. RESULTS: We found no significant difference in treatment efficacy between the BCG-PSN group (71.7%) and the monotherapy group (71.9%). However, the average time of complete relief in the BCG-PSN group was significantly shorter than that in the monotherapy group (36.77 ± 17.33 vs. 51.27 ± 16.80, p = 0.026). In vitro experiments showed that BCG-PSN inhibited ß-hexosaminidase release rates in IgE-sensitized RBL-2H3 cells (p < 0.001). Sequencing data revealed the expression profiles of functional genes, including a significant decrease in Erb-B2 receptor tyrosine kinase 4, which can be regulated by the nuclear factor kappa B (NF-κB) pathway. DISCUSSION: CSU is a chronic, recurrent disease with complex pathogenesis. Mast cells and basophils are the primary target cells of the disease. BCG-PSN decrease the ß-HEX release rates and regulated IgE-mediated mast cell activation in RBL-2H3 cells by mediating immune-related gene expression including ERBB4. These findings suggest that BCG-PSN may mediate ERBB4 expression via the NF-κB pathway and may have value in the treatment of CSU.

Impacts of Haze on Housing Prices: An Empirical Analysis Based on Data from Chengdu (China).

Based on cross-section data of 20 districts in Chengdu, this article reviews the relationships between haze and housing prices with the combined application of Spatial Error Model (SEM) and Spatial Lag Model (SLM). The results illustrate that haze significantly have negative impacts on both the selling and rental prices of houses. Controlling other variables, if the air quality index rises by 0.1, the housing selling prices and rental prices will drop by 3.97% and 4.01%, respectively. Interestingly, housing rental prices have a more significant response to the air quality than housing sale prices. Residents are willing to pay a premium for better air quality and the influence of air quality is partially reflected in housing prices, which indicates that better air quality has been becoming a scarce resource with the improvement of people's living standard. Furthermore, the impacts of haze on housing prices are also expected to lead to a "crowding out effect" in different regions. This would be detrimental for human capital accumulation and will accelerate the regional divergence in the internal economy and population structure, thus forming a region "fence" within cities.

Saccular neck venous aneurysm on color duplex sonography: an analysis of 12 cases.

OBJECTIVE: To discuss the characteristics of saccular neck venous aneurysm on color duplex sonography. METHODS: We retrospectively reviewed 12 cases of saccular neck venous aneurysm confirmed by either venogram or surgical pathology. Clinical information, physical exam of the neck, and characteristics of saccular neck venous aneurysm on color Doppler sonography (CDUS) were analyzed. Diagnosis and differential diagnosis of saccular venous aneurysm on color duplex sonography were discussed. RESULTS: The communication between saccular venous aneurysm and related vein was visualized on grayscale imaging in 11 cases (11/12), which was observed in all 12 cases (12/12) on color Doppler image. Spectral Doppler was useful in the demonstration of venous flow in both the communicating vein and venous aneurysm. The documentation of venous flow in both venous aneurismal sac and communicating vein was obviously improved with contrast enhanced ultrasound in one case. CONCLUSION: It is important to have knowledge of venous aneurysm, an uncommon condition in sonographic practice. Saccular venous aneurysm should be taken into consideration in differential diagnosis when a cystic lesion in the neck appears on color Doppler sonography.