Comparative Analysis of Transcriptome and Proteome Revealed the Common Metabolic Pathways Induced by Prevalent ESBL Plasmids in Escherichia coli.

Antibiotic resistance has emerged as one of the most significant threats to global public health. Plasmids, which are highly efficient self-replicating genetic vehicles, play a critical role in the dissemination of drug-resistant genes. Previous studies have mainly focused on drug-resistant genes only, often neglecting the complete functional role of multidrug-resistant (MDR) plasmids in bacteria. In this study, we conducted a comprehensive investigation of the transcriptomes and proteomes of Escherichia coli J53 transconjugants harboring six major MDR plasmids of different incompatibility (Inc) groups, which were clinically isolated from patients. The RNA-seq analysis revealed that MDR plasmids influenced the gene expression in the bacterial host, in particular, the genes related to metabolic pathways. A proteomic analysis demonstrated the plasmid-induced regulation of several metabolic pathways including anaerobic respiration and the utilization of various carbon sources such as serine, threonine, sialic acid, and galactarate. These findings suggested that MDR plasmids confer a growth advantage to bacterial hosts in the gut, leading to the expansion of plasmid-carrying bacteria over competitors without plasmids. Moreover, this study provided insights into the versatility of prevalent MDR plasmids in moderating the cellular gene network of bacteria, which could potentially be utilized in therapeutics development for bacteria carrying MDR plasmids.

Tail engagement of arrestin at the glucagon receptor.

Arrestins have pivotal roles in regulating G protein-coupled receptor (GPCR) signalling by desensitizing G protein activation and mediating receptor internalization1,2. It has been proposed that the arrestin binds to the receptor in two different conformations, 'tail' and 'core', which were suggested to govern distinct processes of receptor signalling and trafficking3,4. However, little structural information is available for the tail engagement of the arrestins. Here we report two structures of the glucagon receptor (GCGR) bound to ß-arrestin 1 (ßarr1) in glucagon-bound and ligand-free states. These structures reveal a receptor tail-engaged binding mode of ßarr1 with many unique features, to our knowledge, not previously observed. Helix VIII, instead of the receptor core, has a major role in accommodating ßarr1 by forming extensive interactions with the central crest of ßarr1. The tail-binding pose is further defined by a close proximity between the ßarr1 C-edge and the receptor helical bundle, and stabilized by a phosphoinositide derivative that bridges ßarr1 with helices I and VIII of GCGR. Lacking any contact with the arrestin, the receptor core is in an inactive state and loosely binds to glucagon. Further functional studies suggest that the tail conformation of GCGR-ßarr governs ßarr recruitment at the plasma membrane and endocytosis of GCGR, and provides a molecular basis for the receptor forming a super-complex simultaneously with G protein and ßarr to promote sustained signalling within endosomes. These findings extend our knowledge about the arrestin-mediated modulation of GPCR functionalities.

Structural insights into dimerization and activation of the mGlu2-mGlu3 and mGlu2-mGlu4 heterodimers.

Heterodimerization of the metabotropic glutamate receptors (mGlus) has shown importance in the functional modulation of the receptors and offers potential drug targets for treating central nervous system diseases. However, due to a lack of molecular details of the mGlu heterodimers, understanding of the mechanisms underlying mGlu heterodimerization and activation is limited. Here we report twelve cryo-electron microscopy (cryo-EM) structures of the mGlu2-mGlu3 and mGlu2-mGlu4 heterodimers in different conformational states, including inactive, intermediate inactive, intermediate active and fully active conformations. These structures provide a full picture of conformational rearrangement of mGlu2-mGlu3 upon activation. The Venus flytrap domains undergo a sequential conformational change, while the transmembrane domains exhibit a substantial rearrangement from an inactive, symmetric dimer with diverse dimerization patterns to an active, asymmetric dimer in a conserved dimerization mode. Combined with functional data, these structures reveal that stability of the inactive conformations of the subunits and the subunit-G protein interaction pattern are determinants of asymmetric signal transduction of the heterodimers. Furthermore, a novel binding site for two mGlu4 positive allosteric modulators was observed in the asymmetric dimer interfaces of the mGlu2-mGlu4 heterodimer and mGlu4 homodimer, and may serve as a drug recognition site. These findings greatly extend our knowledge about signal transduction of the mGlus.

The impact of the COVID-19 pandemic on nosocomial infections: a retrospective analysis in a tertiary maternal and child healthcare hospital.

Objective: The constant changes in the control strategies of the Corona Virus Disease 2019 (COVID-19) pandemic have greatly affected the prevention and control of nosocomial infections (NIs). This study assessed the impact of these control strategies on the surveillance of NIs in a regional maternity hospital during the COVID-19 pandemic. Methods: This retrospective study compared the observation indicators of nosocomial infections and their changing trends in the hospital before and during the COVID-19 pandemic. Results: In total, 2,56,092 patients were admitted to the hospital during the study. During the COVID-19 pandemic, the main drug-resistant bacteria in hospitals were Escherichia coli, Streptococcus agalactiae, Staphylococcus aureus, Klebsiella pneumoniae, and Enterococcus faecalis. The detection rate of S. agalactiae increased annually, while that of E. faecalis remained the same. The detection rate of multidrug-resistant bacteria decreased during the pandemic (16.86 vs. 11.42%), especially that of CRKP (carbapenem-resistant Klebsiella pneumoniae 13.14 vs. 4.39, P < 0.001). The incidence of nosocomial infections in the pediatric surgery department decreased significantly (OR: 2.031, 95% CI: 1.405-2.934, P < 0.001). Regarding the source of infection, a significant reduction was observed in respiratory infections, followed by gastrointestinal infections. In the routine monitoring of the ICU, the incidence of central line-associated bloodstream infection (CLABSI) decreased significantly (9.4/1,000 catheter days vs. 2.2/1,000 catheter days, P < 0.001). Conclusion: The incidence of nosocomial infections was lower than that before the COVID-19 pandemic. The prevention and control measures for the COVID-19 pandemic have reduced the number of nosocomial infections, especially respiratory, gastrointestinal, and catheter-related infections.

Socially Assistive Robots for People Living with Dementia in Long-Term Facilities: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND AND OBJECTIVE: The purpose of our study was to explore the immediate and long-term effects of socially assistive robots (SARs) on neuropsychiatric symptoms (NPSs), behavioral and psychological symptoms of dementia (BPSD), positive emotional experiences, and social interaction in older people living with dementia. METHODS: We set keywords and used Boolean operators to search the CINAHL, Cochrane Library, EMBASE, IEEE Digital Library, MEDLINE, PsycINFO, PubMed, Web of Science, Scopus, and Chinese Electronic Periodical Service from inception to February 2022 for randomized controlled trials. The Cochrane Collaboration bias assessment tool was used to assess article quality, and RevMan 5.4.1 software was used to conduct the meta-analysis. RESULTS: A total of 14 studies were included in the meta-analysis. SARs can help people living with dementia reduce their NPS of depression and anxiety, provide happiness from positive emotional experiences, and improve their social interaction through conversation. However, there was no significant improvement in agitation behavior, overall BPSD, or quality of life in people living with dementia. In follow-up, it was found that the effect of SRT was limited. CONCLUSION: SARs can reduce depression and increase positive emotions in people living with dementia. They may also reduce the burden on healthcare workers during the COVID-19 pandemic. This research was registered on PROSPERO CRD42020169340.

SARS-CoV-2 Spike Pseudoviruses: A Useful Tool to Study Virus Entry and Address Emerging Neutralization Escape Phenotypes.

SARS-CoV-2 genetic variants are emerging around the globe. Unfortunately, several SARS-CoV-2 variants, especially variants of concern (VOCs), are less susceptible to neutralization by the convalescent and post-vaccination sera, raising concerns of increased disease transmissibility and severity. Recent data suggests that SARS-CoV-2 neutralizing antibody levels are a reliable correlate of vaccine-mediated protection. However, currently used BSL3-based virus micro-neutralization (MN) assays are more laborious, time-consuming, and expensive, underscoring the need for BSL2-based, cost-effective neutralization assays against SARS-CoV-2 variants. In light of this unmet need, we have developed a BSL-2 pseudovirus-based neutralization assay (PBNA) in cells expressing the human angiotensin-converting enzyme-2 (hACE2) receptor for SARS-CoV-2. The assay is reproducible (R2 = 0.96), demonstrates a good dynamic range and high sensitivity. Our data suggest that the biological Anti-SARS-CoV-2 research reagents such as NIBSC 20/130 show lower neutralization against B.1.351 SA (South Africa) and B.1.1.7 UK (United Kingdom) VOC, whereas a commercially available monoclonal antibody MM43 retains activity against both these variants. SARS-CoV-2 spike PBNAs for VOCs would be useful tools to measure the neutralization ability of candidate vaccines in both preclinical models and clinical trials and would further help develop effective prophylactic countermeasures against emerging neutralization escape phenotypes.

Structures of human mGlu2 and mGlu7 homo- and heterodimers.

The metabotropic glutamate receptors (mGlus) are involved in the modulation of synaptic transmission and neuronal excitability in the central nervous system1. These receptors probably exist as both homo- and heterodimers that have unique pharmacological and functional properties2-4. Here we report four cryo-electron microscopy structures of the human mGlu subtypes mGlu2 and mGlu7, including inactive mGlu2 and mGlu7 homodimers; mGlu2 homodimer bound to an agonist and a positive allosteric modulator; and inactive mGlu2-mGlu7 heterodimer. We observed a subtype-dependent dimerization mode for these mGlus, as a unique dimer interface that is mediated by helix IV (and that is important for limiting receptor activity) exists only in the inactive mGlu2 structure. The structures provide molecular details of the inter- and intra-subunit conformational changes that are required for receptor activation, which distinguish class C G-protein-coupled receptors from those in classes A and B. Furthermore, our structure and functional studies of the mGlu2-mGlu7 heterodimer suggest that the mGlu7 subunit has a dominant role in controlling dimeric association and G-protein activation in the heterodimer. These insights into mGlu homo- and heterodimers highlight the complex landscape of mGlu dimerization and activation.

Structures of Gi-bound metabotropic glutamate receptors mGlu2 and mGlu4.

The metabotropic glutamate receptors (mGlus) have key roles in modulating cell excitability and synaptic transmission in response to glutamate (the main excitatory neurotransmitter in the central nervous system)1. It has previously been suggested that only one receptor subunit within an mGlu homodimer is responsible for coupling to G protein during receptor activation2. However, the molecular mechanism that underlies the asymmetric signalling of mGlus remains unknown. Here we report two cryo-electron microscopy structures of human mGlu2 and mGlu4 bound to heterotrimeric Gi protein. The structures reveal a G-protein-binding site formed by three intracellular loops and helices III and IV that is distinct from the corresponding binding site in all of the other G-protein-coupled receptor (GPCR) structures. Furthermore, we observed an asymmetric dimer interface of the transmembrane domain of the receptor in the two mGlu-Gi structures. We confirmed that the asymmetric dimerization is crucial for receptor activation, which was supported by functional data; this dimerization may provide a molecular basis for the asymmetric signal transduction of mGlus. These findings offer insights into receptor signalling of class C GPCRs.

Facile Fabrication of Self-Assembly Functionalized Polythiophene Hole Transporting Layer for High Performance Perovskite Solar Cells.

Crystallinity and crystal orientation have a predominant impact on a materials' semiconducting properties, thus it is essential to manipulate the microstructure arrangements for desired semiconducting device performance. Here, ultra-uniform hole-transporting material (HTM) by self-assembling COOH-functionalized P3HT (P3HT-COOH) is fabricated, on which near single crystal quality perovskite thin film can be grown. In particular, the self-assembly approach facilitates the P3HT-COOH molecules to form an ordered and homogeneous monolayer on top of the indium tin oxide (ITO) electrode facilitate the perovskite crystalline film growth with high quality and preferred orientations. After detailed spectroscopy and device characterizations, it is found that the carboxylic acid anchoring groups can down-shift the work function and passivate the ITO surface, retarding the interface carrier recombination. As a result, the device made with the self-assembled HTM show high open-circuit voltage over 1.10 V and extend the lifetime over 4,300 h when storing at 30% relative humidity. Moreover, the cell works efficiently under much reduced light power, making it useful as power source under dim-light conditions. The demonstration suggests a new facile way of fabricating monolayer HTM for high efficiency perovskite devices, as well as the interconnecting layer needed for tandem cell.

Laparoscopic metroplasty: reconstructive surgery for unicornuate uterus with noncommunicating, functional uterine horn.

OBJECTIVE: To demonstrate laparoscopic surgery for a patient with unicornuate uterus and a large hematometra in the noncommunicating uterine horn. DESIGN: Narrated video featuring the diagnostic tests and surgical management. SETTING: Academic tertiary hospital. PATIENT(S): A 13-year-old woman, gravida 0 with menarche at 9 years old, had severe dysmenorrhea during her recent menstrual cycles. The results of transrectal three-dimensional sonography, hysteroscopy, and magnetic resonance imaging (MRI) were consistent for a uterine didelphys composed of a right unicornuate uterus and a left hemiuterus with hematometra and no connection to the cervix. Left adnexal endometrioma and ipsilateral renal agenesis were also noted. INTERVENTION(S): Laparoscopic adhesiolysis and enucleation of the left ovarian endometrioma were first performed. Then, implementing the concepts of Strassman unification method, a horizontal incision was made on the medial side of each hemicorpus, starting from the left rudimentary horn and ending at the fundal area of the right hemiuterus. The incision was carried deep enough to reach the endometrium. The opposing, reverted myometrium was then reapproximated from the lower end of the uterus to the upper fundal part in two layers, using absorbable bidirectional monofilament barbed suture. The outer serosal layer was closed with 1-0 Monocryl via a running continuous suture. On postoperative day 2, the patient was discharged uneventfully. MAIN OUTCOME MEASURE(S): Symptomatic relief and restoration of normal and functional anatomy. RESULT(S): The patient has regular menstrual cycles with no recurrence of dysmenorrhea or ovarian endometrioma. At a 2-year postoperative follow-up evaluation, hysteroscopic examination revealed a single uterine cavity with a small fundal septum. The MRI scans showed an anteverted, symmetrical uterus. CONCLUSION(S): In comparison with the widely applied hemihysterectomy, reconstructive laparoscopic metroplasty not only effectively achieves symptomatic relief but also offers better uterine symmetry and a larger intrauterine cavity via unification of the uterus.

Characterization of Purple Acid Phosphatase Family and Functional Analysis of GmPAP7a/7b Involved in Extracellular ATP Utilization in Soybean.

Low phosphate (Pi) availability limits crop growth and yield in acid soils. Although root-associated acid phosphatases (APases) play an important role in extracellular organic phosphorus (P) utilization, they remain poorly studied in soybean (Glycine max), an important legume crop. In this study, dynamic changes in intracellular (leaf and root) and root-associated APase activities were investigated under both Pi-sufficient and Pi-deficient conditions. Moreover, genome-wide identification of members of the purple acid phosphatase (PAP) family and their expression patterns in response to Pi starvation were analyzed in soybean. The functions of both GmPAP7a and GmPAP7b, whose expression is up regulated by Pi starvation, were subsequently characterized. Phosphate starvation resulted in significant increases in intracellular APase activities in the leaves after 4 days, and in root intracellular and associated APase activities after 1 day, but constant increases were observed only for root intracellular and associated APase activities during day 5-16 of P deficiency in soybean. Moreover, a total of 38 GmPAP members were identified in the soybean genome. The transcripts of 19 GmPAP members in the leaves and 17 in the roots were upregulated at 16 days of P deficiency despite the lack of a response for any GmPAP members to Pi starvation at 2 days. Pi starvation upregulated GmPAP7a and GmPAP7b, and they were subsequently selected for further analysis. Both GmPAP7a and GmPAP7b exhibited relatively high activities against adenosine triphosphate (ATP) in vitro. Furthermore, overexpressing GmPAP7a and GmPAP7b in soybean hairy roots significantly increased root-associated APase activities and thus facilitated extracellular ATP utilization. Taken together, these results suggest that GmPAP7a and GmPAP7b might contribute to root-associated APase activities, thus having a function in extracellular ATP utilization in soybean.

Simultaneous determination of nitrate and nitrite in vegetables by poly(vinylimidazole-co-ethylene dimethacrylate) monolithic capillary liquid chromatography with UV detection.

Simultaneous determination of nitrate (NO3‾) and nitrite (NO2‾) in vegetables was performed on a poly(1-vinylimidazole-co-ethylene dimethacrylate) (VIM-EDMA) monolithic column by capillary liquid chromatography (LC) with UV detection. Good linearity (0.5-100 µg mL-1 i.e. 12.5 -2500 µg g-1 in vegetables) was obtained with coefficient of determination > 0.996. Limits of detection (signal-to-noise ratio: S/N= 3) were estimated at 0.06 and 0.05 µg mL-1, which corresponded to 1.50 and 1.25 µg g-1 for NO2‾ and NO3‾, respectively, in vegetables. The limits of quantification (S/N= 10) were estimated at 0.17 and 0.16 µg mL-1 (4.25 and 4.00 µg g-1 in vegetables) for NO2‾ and NO3‾, respectively. Although the detection limits were relatively higher than other LC-UV techniques, this proposed method offered satisfactory sensitivity for complying the Acceptable Daily Intake (ADI) levels set by EU to monitor the occurrence of NO2‾ and NO3‾in vegetables. The intra-day/inter-day precision (0.14-3.35%/0.06-6.93%) and accuracy (90.33-103.32%/96.00-101.26%) were also examined for method validation. No obvious carry-over and decline of separation efficiency were observed for more than 200 analyses of real samples. The occurrence of NO2‾ and NO3‾in various vegetable samples was investigated to demonstrate the potential of utilizing the developed polymeric monolith-based capillary LC-UV method for food safety application.

Separation of inorganic anions by capillary ion chromatography with UV detection using poly(vinylimidazole-co-ethylene dimethacrylate) monolithic column.

Poly(1-vinylimidazole-co-ethylene dimethacrylate) (VIM-EDMA) monolithic stationary phase was applied for separation of inorganic anions by capillary ion chromatography (IC). The retention of inorganic anions on the VIM-EDMA column was investigated using various salt solutions as the eluent. Good separation of inorganic anions was obtained on VIM-EDMA monolithic column using NH4Cl as the eluent. Good mechanical stability and low swelling propensity values (0.12 and -0.02 for ACN and MeOH, respectively) were obtained. The column repeatability was also examined by determining the relative standard deviations (RSDs) of retention time and peak area of target anions. Relatively low RSDs (n = 7) of retention time (<2.3%) and peak area (<8.8%) were obtained on the VIM-EDMA column. The utilization of VIM-EDMA column for potential environmental application was also demonstrated by determining the occurrence of inorganic anions in various environmental water samples without sample preparation process.

History of Urinary Retention Is a Risk Factor for Infection after Prostate Biopsy: A Nationwide, Population-Based Cohort Study.

BACKGROUND AND AIM: Infection or bleeding after transrectal prostate biopsy remains a concern of both patients and urologists. We explored the risk of association of certain co-morbidities with both complications. PATIENTS AND METHODS: Using the Taiwan National Health Insurance Research Database, we identified patients undergoing prostate biopsy from 2000 to 2013. We used logistic multivariable regression to search for associations between post-biopsy hospitalization and the two co-morbidities within a year after biopsy. RESULTS: Among 3,601 prostate biopsies, 100 infections (3.77%) and 52 (1.44%) bleeding-related emergency room visits and hospitalizations were recorded within 30 days after biopsy. The group having the biopsy as an inpatient exhibited older age (p < 0.0001) and a higher percentage of having diabetes mellitus (p = 0.015) than patients without either complication. The logistic multivariable regression analysis showed that urinary retention, freedom from diabetes, and performance as an outpatient procedure were independent risk factors for infection-related hospitalization (odds ratios 1.81, 1.96, and 1.72; p values 0.031, 0.037, and 0.010, respectively). CONCLUSION: Patients with a recent history of urinary retention have a higher probability of infection-related hospitalization after prostate biopsy.

Preparation and characterization of vinylimidazole-based polymer monolithic stationary phases for reversed-phase and hydrophilic interaction capillary liquid chromatography.

In this study, we applied 1-vinylimidazole (VIM) as the functional monomer to prepare a series of VIM-based monolithic stationary phases for both reversed-phase and hydrophilic interaction capillary liquid chromatography (LC) using various dimethacrylates (EDMA: ethylene dimethacrylate; HDDMA: 1,6-hexanediol dimethacrylate; DDDMA: 1,10-decanediol dimethacrylate) as cross-linkers. With a simple thermally initiated free-radical cross-linking polymerization process, VIM-based monolithic stationary phases have been successfully prepared. The porosity, permeability, and column efficiency of synthesized VIM-based monolithic stationary phases were characterized. With similar total porosity (85-90%), the VIM-HDDMA monoliths showed the lowest permeability among the three sets of VIM-based stationary phases. Various sets of non-polar (alkyl benzenes and polycyclic aromatic hydrocarbons) and polar analytes (phenol derivatives and amphenicol antibiotics) were applied as model compounds to further investigate the retention behavior of the VIM-based monolithic stationary phases for reversed-phase capillary LC analysis using selected VIM-based monolithic columns. While a mixture of organic acids was employed to perform HILIC analysis using the selected VIM-based monolithic columns. The separation selectivity and retention behavior of the VIM-based monolithic stationary phases were compared to those obtained using three previously prepared alkyl methacrylate-based monolithic columns. Strong retention and good resolution of polar analytes (such as phenol derivatives, amphenicol antibiotics, and organic acids) were observed using the selected VIM-based monolithic columns. The strong retention and good resolution might be attributed to the additional hydrogen-bonding between the hydrogen-donating analytes and the hydrogen-accepting imidazolium functionality on the VIM-based stationary phase. The applicability for both reversed-phase and HILIC capillary LC analysis has also been demonstrated using the selected VIM-based monolithic columns.