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Late spring coldness (LSC) is the main limiting factor threatening wheat yield and quality stability. Optimal nutrient management is beneficial in mitigating the harms of LSC by improving wheat root physiology. This study proposed a nutrient management strategy that postponed the application of phosphorus (P) and potassium (K), effectively strengthening wheat's defense against LSC. This experiment used the winter cultivar "Yannong19" (YN 19) as plant material for two consecutive years (2021–2022 and 2022–2023). Two fertilizer treatments were used: traditional P and K fertilizers application (R1: base fertilizer: jointing fertilizer = 10:0) and postponed P and K fertilizers application (R2: base fertilizer: jointing fertilizer = 5:5); wheat plants at the anther connective formation stage shifted to temperature-controlled phytotrons for normal (T0, 11 °C/4 h) and low temperatures (T1, 4 °C/4 h; T2, −4 °C/4 h) as treatments of LSC. The results showed that under low temperature (LT) treatment, compared with R1, the R2 treatment increased the concentrations of osmotic adjustment substances (soluble sugars and soluble protein contents by 6.2–8.7% and 3.0–8.9%), enhanced activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase activities by 2.2–9.1%, 6.2–9.7% and 4.2–8.4%), balanced the hormone concentrations (increased IAA and GA3 contents by 2.8–17.5% and 10.4–14.1% and decreased ABA contents by 7.2–14.3%), and reduced the toxicity (malondialdehyde, hydrogen peroxide content and O2·− production rate by 5.7–12.4%, 17.7–22.8% and 19.1–19.1%) of the cellular membranes. Furthermore, the wheat root physiology in R2 significantly improved as the root surface area and dry weight increased by 5.0–6.6% and 4.7–6.6%, and P and K accumulation increased by 7.4–11.3% and 12.2–15.4% compared to R1, respectively. Overall, the postponed application of P and K fertilizers enhanced the physiological function of the root system, maintained root morphology, and promoted the accumulation of wheat nutrients under the stress of LSC. [ABSTRACT FROM AUTHOR]

The position of the nozzle in the jet mechanism of the impulse turbine may cause an eccentric jet due to size processing and installation deviations. To study the effect of jet needle eccentricity on the jet, this article first analyzes the jet characteristics of the jet mechanism with different openings (20, 40, 60, 80, 100%) under 4.8% eccentricity, verify the reliability of the research method in this paper. Then the focus is on the jet characteristics of the jet mechanism at different eccentricities (0, 1, 2.1, 4.8, 8, and 14%) at 40% opening. The results show that as the eccentricity of the nozzle increases, the jet appears to be asymmetrical, and the shape of the jet at the inlet section of the runner gradually changes and becomes an irregular shape. The eccentricity of the water jet increases with the increase of the eccentricity of the needle; the efficiency of the injection mechanism gradually decreases, and the energy loss gradually increases. Before the eccentricity of 4.8%, the efficiency decreases more slowly, and after the eccentricity of 4.8%, the rate of efficiency decrease is accelerated.

This paper introduces a new type of flexible rudder surface based on the cosine-type zero Poisson's ratio honeycomb to enhance the adaptive capabilities of aircraft and enable multi-condition, rudderless flight. The zero Poisson's ratio honeycomb structure exhibits exceptional in-plane and out-of-plane deformation capacities, as well as a high load-bearing capability. To investigate the deformation characteristics of flexible rudder surfaces utilizing cosine honeycomb structures, this study undertakes a comprehensive investigation through finite element simulation and 3D printing experiments. Moreover, this study analyzed the impact of honeycomb parameters and layout on the deflection performance and weight. The flexible rudder surface, fabricated from nylon, achieves smooth and consistent chordwise bending deformation, as well as uniform spanwise deformation within a tolerance of ±25°, and the maximum equivalent stress observed was 31.99 MPa, which is within the material's allowable stress limits (50 MPa). Finite element simulation results indicate that once the deflection angle of the rocker exceeds 15°, a discernible deviation arises between the actual deflection angle of the flexible control surface and that of the rocker. Furthermore, this deviation escalates with increasing rocker rotation angles, and this discrepancy can be mitigated by augmenting the number of cosine honeycomb cells within the flexible rudder surface. Finally, a prototype of the flexible rudder surface was successfully produced using 3D printing technology, and the experimental results confirmed the deformation behavior, aligning with simulation outcomes with a deviation of less than 20%. These findings confirm the effective deflection performance of the designed flexible rudder surface, highlighting its potential application in small unmanned aerial vehicles. [ABSTRACT FROM AUTHOR]

The long-term maintenance of low concentration of dissolved oxygen (DO) is an important condition for the enrichment of anammox bacteria (AnAOB) in the electrochemical anammox system (EAS). In this study, a new method to control DO by the combination of sodium sulfite with nitrogen stripping was attempted, and the influence of sodium sulfite concentration on the nitrogen removal performance was studied. The results show that under the optimal conditions (i.e., sodium sulfite concentration = 200 mg/L, nitrogen stripping time = 40–60 min, nitrogen flow = 350 mL/min), the DO in the water was controlled below 0.3 mg/L, which saves more than half of the time required for removing DO compared with the nitrogen stripping method (120–140 min). However, the total nitrogen removal rate (NRR) at the optimal current density of 0.10 mA/cm2 decreased gradually, and the NRR was 0.0091, 0.0061, 0.0026, and 0.0006 g N/[L∙d] at the sodium sulfite concentration of 0, 200, 400, and 600 mg/L, respectively. Simultaneously the specific anammox activity decreased from 0.0077 g N/[g VSS∙d] to 0.0032 g N/[g VSS∙d]. It is concluded that when the current density was 0.10 mA/cm2 and the concentration of sodium sulfite was 200 mg/L, the optimal operating conditions were both anammox activity and deoxidation. Therefore, the combination of sodium sulfite with nitrogen stripping has great application potential to control DO in the EAS. [ABSTRACT FROM AUTHOR]

The development and maturation of sperm entails intricate metabolic processes involving water molecules, amino acids, hormones, and various substances. Among these processes, the role of aquaporins (aqps) in the testis is crucial. Turbot (Scophthalmus maximus) is a significant marine flatfish species in China; however, natural egg laying in females is not feasible under cultured conditions. Consequently, artificial insemination becomes necessary, requiring the retrieval of sperm and eggs through artificial methods. In this study, we combined genomic, transcriptomics, RT-qPCR, computer-assisted sperm analysis (CASA), and immunohistochemistry to investigate the involvement of the aqp family in spermatogenesis in turbot. Through genomic data analysis, we identified 16 aqps genes dispersed across 13 chromosomes, each exhibiting the characteristic major intrinsic protein (MIP) domain associated with AQPs. The results from RNA-seq and RT-qPCR analysis revealed prominent expression of aqp4, 10, and 12 during the proliferative stage, whereas aqp1 showed primary expression during the mature stage. aqp11 displayed high expression levels during both MSII and MSV stages, potentially contributing significantly to the proliferation and maturation of male germ cells. Conversely, aqp8 showed elevated expression levels during the MSIII, MSIII-IV, and MSIV stages, suggesting its direct involvement in spermiogenesis. Immunohistochemical analysis unveiled the predominant localization of AQP1 protein in male germ cells rather than Sertoli cells, specifically concentrated in the head of sperm within cysts. Furthermore, a noteworthy decline in sperm motility was observed when sperm were subjected to treatment with either the AQP1-specific inhibitor (HgCl2) or the AQP1 antibody. However, no direct correlation was found between the expression of Smaqp1 and sperm quality. Overall, these findings provide new insights into the involvement of aqps in teleost spermatogenesis. Moreover, they hold potential for improving techniques related to sperm activation and cryopreservation, offering valuable knowledge for future advancements in this field. [ABSTRACT FROM AUTHOR]

Having a limited number of VH segments, cattle rely on uniquely long DH gene segments to generate CDRH3 length variation (3–70 aa) far greater than that in humans or mice. Bovine antibodies with ultralong CDRH3s (>50 aa) possess unusual structures and abilities to bind to special antigens. In this study, we replaced most murine endogenous DH segments with bovine DH genes, generating a mouse line termed B‐DH. The use of bovine DH genes significantly increased the length variation of CDRH3 and consequently the Ig heavy chain repertoire in B‐DH mice. However, no ultralong CDRH3 was observed in B‐DH mice, suggesting that other factors, in addition to long DH genes, are also involved in the formation of ultralong CDRH3. The B‐DH mice mounted a normal humoral immune response to various antigens, although the B‐cell developmental paradigm was obviously altered compared with wild‐type mice. Additionally, B‐DH mice are not predisposed to the generation of autoantibodies despite the interspecies DH gene replacement. The B‐DH mice reported in this study provide a unique model to answer basic questions regarding the synergistic evolution of DH and VH genes, VDJ recombination and BCR selection in B‐cell development. [ABSTRACT FROM AUTHOR]

To the Editor: Carbapenem resistance in Enterobacteriaceae can occur through the production of carbapenem-hydrolyzing enzymes such as New Delhi metallo-[beta-lactamase-1 (NDM-1) (1). In recent years, plasmid-mediated NDM-1 has spread rapidly [...]

Hypervirulent Klebsiella pneumoniae (hvKp), one of the major community-acquired pathogens, can cause invasive infections such as liver abscess. In recent years, bacteriophages have been used in the treatment of K. pneumoniae , but the characteristics of the phage-resistant bacteria produced in the process of phage therapy need to be evaluated. In this study, two Podoviridae phages, hvKpP1 and hvKpP2, were isolated and characterized. In vitro and in vivo experiments demonstrated that the virulence of the resistant bacteria was significantly reduced compared with that of the wild type. Comparative genomic analysis of monoclonal sequencing showed that nucleotide deletion mutations of wzc and wcaJ genes led to phage resistance, and the electron microscopy and mucoviscosity results showed that mutations led to the loss of the capsule. Meanwhile, animal assay indicated that loss of capsule reduced the virulence of hvKp. These findings contribute to a better understanding of bacteriophage therapy, which not only can kill bacteria directly but also can reduce the virulence of bacteria by phage screening. [ABSTRACT FROM AUTHOR]

In contrast to humans or rabbits, in which maternal IgG is transmitted to offspring prenatally via the placenta or the yolk sac, large domestic animals such as pigs, cows and sheep transmit IgG exclusively through colostrum feeding after delivery. The extremely high IgG content in colostrum is absorbed by newborns via the small intestine. Although it is widely accepted that the neonatal Fc receptor, FcRn, is the receptor mediating IgG transfer across both the placenta and small intestine, it remains unclear whether FcRn also mediates serum IgG transfer across the mammary barrier to colostrum/milk, especially in large domestic animals. In this study, using a FcRn knockout pig model generated with a CRISPR‐Cas9‐based approach, we clearly demonstrate that FcRn is not responsible for the IgG transfer from serum to colostrum in pigs, although like in other mammals, it is involved in IgG homeostasis and mediates IgG absorption in the small intestine of newborns. [ABSTRACT FROM AUTHOR]

Purpose: Acinetobacter baumannii is associated with both hospital-acquired infections and community-acquired pneumonia (CAP). Here, we describe a novel strain of A. baumannii in a case of CAP in a previously healthy rural villager from Central Eastern China. Materials and Methods: A. baumannii isolated from the patient (LS01) was compared to well-characterized pathogenic strain (AB5075), nosocomial circulating strain in China (ZJ06), and wild-type strain (ATCC17978). Growth rate studies were conducted under different environmental stressors, and virulence studies were performed using Galleria mellonella larvae. Whole genome sequencing (WGS) was performed using MinIon and MiSeq. Center for Genomic Epidemiology, CLCbio, Geneious, and Virulence Factors of Pathogenic Bacteria database were used for genomic analysis. Results: LS01 grew significantly faster at 37°C and 42°C and in the presence of zinc compared to other strains. LS01 was more virulent in G. mellonella, killing all larvae within 8 h. Although WGS revealed 44 virulence genes, these genes were also present in the other strains. While two chromosomally encoded β-lactamases were identified, there were no plasmids identified and LS01 was pan-susceptible to all antibiotics tested. Phylogenetic analysis revealed that the closest related strains were only 72.552% identical, supporting a novel strain. Conclusion: LS01 is a novel strain of hypervirulent yet pan-drug susceptible A. baumannii isolated from a patient with no prior hospitalizations, sick contacts, or any of the typical risk factors. This raises concerns for an emerging pathogen, and more epidemiological studies should be conducted to assess the prevalence of this A. baumannii strain. [ABSTRACT FROM AUTHOR]

Background: To investigate the diagnostic efficacy of long noncoding RNA metastasis‐associated in lung adenocarcinoma transcript l (MALAT1) as a candidate serological biomarker for non‐small cell lung cancer (NSCLC). Methods: Diagnostic studies relevant to circulation long noncoding RNA MALAT1 as a candidate serological biomarker for NSCLC were electronically systematically searched in PubMed, EMBASE, EBSCO and CNKI databases. Suitable studies were included in the meta‐analysis by pooling the diagnostic sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (−LR), diagnostic odds ratio (DOR) and area under the symmetric ROC curve (AUC) through a random or fixed effects model. Deeks' funnel plot was applied for publication bias evaluation. Results: Six studies with eight datasets were finally included in the meta‐analysis after a systematic search of the databases was performed. The pooled diagnostic sensitivity, specificity, +LR, −LR and DOR were 0.81 (95% CI:0.78–0.84), 0.67 (95% CI:0.63–0.71), 2.61 (95% CI:1.81–3.71), 0.28 (95% CI:0.19–0.43) and 13.73 (95% CI:6.19–30.44), respectively. The pooled area under the ROC curve (AUC) were 0.8663 and 0.8658, respectively by symmetric and asymmetric methods. Conclusion: Based on the results of our study, serum long noncoding RNA MALAT1 is a promising biomarker for NSCLC screening. However, due to its low specificity, MALAT1 positive cases need further validation for NSCLC by other diagnostic methods such as radiology, cytology, etc. [ABSTRACT FROM AUTHOR]

In order to study the influence of third mediums on the formation and evolution behaviours of rail corrugation, two series of rolling-sliding tests were performed. Firstly, tests under the dry and different third mediums (oil, grease, water, friction modifier and windblown sand) conditions were conducted to study the influence of third mediums on the formation of rail corrugation. Secondly, rail rollers were first rolled under the dry condition until a stable rail corrugation was formed. Then, water and friction modifier were added into the wheel-rail interface to investigate the role of third mediums on the evolution behaviours of rail corrugation. The results indicated that third mediums had a significant influence on the wheel-rail damage and the formation and evolution of rail corrugation. Compared with the dry condition, both the mass losses and the damage of rail rollers were alleviated under third mediums conditions. The continuous application of third mediums at the wheel-rail interface could alleviate the formation of rail corrugation significantly. When non-solid third mediums existed at the wheel-rail interface (oil, grease, water and friction modifier), no corrugation was observed. In the dynamic windblown sand environment, the corrugation was obviously slighter than that under the dry contact condition. After corrugation was formed on the rail roller, the application of water and friction modifier could alleviate the amplitude of rail corrugation. Furthermore, with the increase in the number of cycles, the amplitude of rail corrugation first increased and then remained nearly stable. Under the dry contact condition, the crack length in the trough was larger than that in the crest. When liquid third mediums were applied, the cracks at the crest were ground away. However, some liquid would enter into the pre-existed crack in the trough, resulting in the severe rolling contact fatigue damage of rail. • The influence of different third mediums on the generation and evolution of rail corrugation was studied. • The third medium (water, oil, grease, FM) could alleviate the generation of rail corrugation. • The application of third mediums, especially water, would result in the reduction of the amplitude of rail corrugation, the transition from oxidative wear to fatigue wear in the crest and severe fatigue damage in the trough. • The influence mechanism of third mediums on the development of rail corrugation was proposed. [ABSTRACT FROM AUTHOR]

Background: The occurrence of non-contiguous, multiple, and remote involvement tuberculous spondylitis is rare. The clinical presentation in patients with multifocal musculoskeletal tuberculosis may closely mimic that in patients with multiple bone metastases, which makes the accurate clinical diagnosis challenging. Herein, we report a multifocal musculoskeletal tuberculosis case that was misdiagnosed for 8 months as multiple bone metastases.Case Presentation: A 63-year-old male farmer of Chinese Han ethnicity presented to us with pain in left side of the neck, right side of the chest and the back for 10 months without typical tuberculosis symptoms. His past medical history, the CT and fluoroscopy-guided biopsy were negative for tuberculosis. Interferon gamma by T-SPOT was also negative. Radiological findings including CT, MRI and PET-CT suggested that the patient had multiple metastases. Accordingly, the patient was misdiagnosed as having musculoskeletal tumors until a swelling under the right nipple ulcerated. The smear test for acid-fast bacilli and the PCR test for TB-DNA of the pus from the swollen area were both positive, leading to the final correct diagnosis of musculoskeletal tuberculosis.Conclusion: The proper diagnosis of musculoskeletal tuberculosis is clinically challenging due to Mycobacterium tuberculosis variants involved and atypical presentations, especially when the lesions are multiple. Our findings indicate that multiple tuberculous spondylitis must be considered in the differential diagnosis of multiple musculoskeletal lesions. [ABSTRACT FROM AUTHOR]

Matrix metalloproteinases (MMPs) are a cluster of enzymes that degrade the extracellular matrix (ECM) and some intracellular proteins; as such, they play an important role in tissue regeneration, infant growth, animal reproduction, and immunity. Most research into MMPs focuses mainly on their effects on the mammalian immune system. However, it is not clear how MMPs affect immune processes in crustaceans. Here, we cloned the open reading frame (ORF) of Eriocheir sinensis (Chinese mitten crab) MMP-14 (EsMMP-14) to explore the role of MMPs in crustacean innate immune responses. RT-PCR results showed that stimulation of crab with LPS and poly I:C upregulated expression of EsMMP-14 markedly. Besides, following the stimulation of 20-Hydroxyecdysone, the expression level of EsMMP-14 increased robustly, suggesting that EsMMP-14 involved in the molt process of E. sinensis. Hematoxylin and eosin staining of hepatopancreas and intestine revealed that knocking down EsMMP-14 maintained morphology following infection by Bacillus thuringiensis. Moreover, downregulated expression of EsMMP-14 increased the survival rate of infected E. sinensis. These results show that EsMMP-14 plays a role in innate immune responses of E. sinensis and fills a gap in our knowledge about the function of MMPs in crustaceans. • LPS and poly I:C stimulation induced overexpression of EsMMP-14. • EsMMP-14 expressed robustly following the stimulation of 20-Hydroxyecdysone. • RNAi of EsMMP-14 maintained normal tissue morphology following infection. • RNAi of EsMMP-14 increased the survival rate of infected E. sinensis. [ABSTRACT FROM AUTHOR]

Background: The use of sex-specific molecular markers has become a prominent method in enhancing fish production and economic value, as well as providing a foundation for understanding the complex molecular mechanisms involved in fish sex determination. Over the past decades, research on male and female sex identification has predominantly employed molecular biology methodologies such as restriction fragment length polymorphism, random amplification of polymorphic DNA, simple sequence repeat, and amplified fragment length polymorphism. The emergence of high-throughput sequencing technologies, particularly Illumina, has led to the utilization of single nucleotide polymorphism and insertion/deletion variants as significant molecular markers for investigating sex identification in fish. The advancement of sex-controlled breeding encounters numerous challenges, including the inefficiency of current methods, intricate experimental protocols, high costs of development, elevated rates of false positives, marker instability, and cumbersome field-testing procedures. Nevertheless, the emergence and swift progress of PacBio high-throughput sequencing technology, characterized by its long-read output capabilities, offers novel opportunities to overcome these obstacles., Findings: Utilizing male/female assembled genome information in conjunction with short-read sequencing data survey and long-read PacBio sequencing data, a catalog of large-segment (>100 bp) insertion/deletion genetic variants was generated through a genome-wide variant site-scanning approach with bidirectional comparisons. The sequence tagging sites were ranked based on the long-read depth of the insertion/deletion site, with markers exhibiting lower long-read depth being considered more effective for large-segment deletion variants. Subsequently, a catalog of bulk primers and simulated PCR for the male/female variant loci was developed, incorporating primer design for the target region and electronic PCR (e-PCR) technology. The Japanese parrotfish (Oplegnathus fasciatus), belonging to the Oplegnathidae family within the Centrarchiformes order, holds significant economic value as a rocky reef fish indigenous to East Asia. The criteria for rapid identification of male and female differences in Japanese parrotfish were established through agarose gel electrophoresis, which revealed 2 amplified bands for males and 1 amplified band for females. A high-throughput identification catalog of sex-specific markers was then constructed using this method, resulting in the identification of 3,639 (2,786 INS/853 DEL, ♀ as reference) and 3,672 (2,876 INS/833 DEL, ♂ as reference) markers in conjunction with 1,021 and 894 high-quality genetic sex identification markers, respectively. Sixteen differential loci were randomly chosen from the catalog for validation, with 11 of them meeting the criteria for male/female distinctions. The implementation of cost-effective and efficient technological processes would facilitate the rapid advancement of genetic breeding through expediting the high-throughput development of sex genetic markers for various species., Conclusions: Our study utilized assembled genome information from male and female individuals obtained from PacBio, in addition to data from short-read sequencing data survey and long-read PacBio sequencing data. We extensively employed genome-wide variant site scanning and identification, high-throughput primer design of target regions, and e-PCR batch amplification, along with statistical analysis and ranking of the long-read depth of the variant sites. Through this integrated approach, we successfully compiled a catalog of large insertion/deletion sites (>100 bp) in both male and female Japanese parrotfish., (© The Author(s) 2024. Published by Oxford University Press GigaScience.)

Background: This is a retrospective cross-sectional study aiming to explore the clinical and imaging manifestations of Chlamydia psittaci pneumonia (CPP), thus improving its diagnosis, guiding its early clinical treatment, and reducing its mortality rate., Methods: Fifty cases of CPP diagnosed by hospitals across the country with metagenomics next-generation sequencing (mNGS) from January 2019 to March 2021 were collected. Its clinical symptoms, laboratory test results, and computed tomography (CT) features were discussed., Results: Forty patients had a history of poultry exposure; 37 experienced respiratory symptoms, 48 had a fever, 14 experienced gastrointestinal symptoms, and 12 experienced neurological symptoms; 34 patients had normal blood cell counts, 49 patients had elevated C-reactive protein, and 24 showed decreased serum sodium. Imaging manifestations: (I) Distribution: lesions were limited to a single lung in 31 patients, lesions were distributed in bilateral lungs in 19 patients; (II) Signs: 37 patients developed the "fine mesh sign". Necrosis, cavity and "tree-in-bud" were not observed. Pleural effusion occurred in 33 patients, mediastinal lymphadenopathy in 18, and splenomegaly in 15 patients., Conclusions: Patients with CPP often have a history of poultry exposure and present with fever and increased C-reactive protein. White blood cells may be slightly increased or completely normal. Hyponatremia may occur in some patients, and multiple systems may be clinically involved. The imaging can show lesions with unilateral or bilateral lung distribution and a rapid progression. Both the lung parenchyma and the interstitium are involved. Fine mesh sign is the most common sign. Necrosis, cavitation, and tree-in-bud signs are not observed. In conclusion, imaging examinations are helpful for the early diagnosis of this disease and the evaluation of the treatment effect., Competing Interests: Conflicts of Interest:All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-22-809/coif). The authors have no conflicts of interest to declare., (2023 Quantitative Imaging in Medicine and Surgery. All rights reserved.)

CRISPR/Cas9 technology has been applied to many arthropods. However, application of this technology to crustaceans remains limited because of the unique characteristics of embryos. Our group has developed a microinjection system to introduce the CRISPR/Cas9 system into Neocaridina heteropoda embryos (one-cell stage). Using the developed method, we mutated the target gene Nh-scarlet (N. heteropoda scarlet), which functions in eye development and pigmentation. The results showed that both eye color and shape were altered in individuals in which Nh-scarlet was knocked out. Furthermore, this system was also successfully applied to another decapod crustacean, Eriocheir sinensis. DNA sequencing revealed that the zoeae with red eyes had an edited version of Es-scarlet. This study provides a stable microinjection method for freshwater crustaceans, and will contribute to functional genomics studies in various decapods., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2022. Published by The Company of Biologists Ltd.)

Atypical TCRδ found in sharks, amphibians, birds, and monotremes and TCRμ found in monotremes and marsupials are TCR chains that use Ig or BCR-like variable domains (VHδ/Vμ) rather than conventional TCR V domains. These unconventional TCR are consistent with a scenario in which TCR and BCR, although having diverged from each other more than 400 million years ago, continue to exchange variable gene segments in generating diversity for Ag recognition. However, the process underlying this exchange and leading to the evolution of these atypical TCR receptor genes remains elusive. In this study, we identified two TCRα/δ gene loci in the Chinese alligator ( Alligator sinensis ). In total, there were 144 V, 154 Jα, nine Jδ, eight Dδ, two Cα, and five Cδ gene segments in the TCRα/δ loci of the Chinese alligator, representing the most complicated TCRα/δ gene system in both genomic structure and gene content in any tetrapod examined so far. A pool of 32 VHδ genes divided into 18 subfamilies was found to be scattered over the two loci. Phylogenetic analyses revealed that these VHδ genes could be related to bird VHδ genes, VHδ/Vμ genes in platypus or opossum, or alligator VH genes. Based on these findings, a model explaining the evolutionary pattern of atypical TCRδ/TCRμ genes in tetrapods is proposed. This study sheds new light on the evolution of TCR and BCR genes, two of the most essential components of adaptive immunity., (Copyright © 2020 by The American Association of Immunologists, Inc.)

In this study, we identified a pair of nonrearranging VJ-joined Ig superfamily genes, termed putative remnants of an Ag receptor precursor ( PRARP ) genes, in chicken. Both genes encode a single V-set Ig domain consisting of a canonical J-like segment and a potential immunoreceptor tyrosine-based inhibitory or switch motif in the cytoplasmic region. In vitro experiments showed that both genes were expressed at the cell surface as membrane proteins, and their recombinant products formed a monomer and a disulfide-linked homodimer or a heterodimer. These two genes were mainly expressed in B and T cells and were upregulated in response to stimulation with poly(I:C) in vitro and vaccination in vivo. Orthologs of PRARP have been identified in bony fish, amphibians, reptiles, and other birds, and a V-C1 structure similar to that of Ig or TCR chains was found in all these genes, with the exception of those in avian species, which appear to contain degenerated C1 domains or divergent Ig domains. Phylogenetic analyses suggested that the newly discovered genes do not belong to any known immune receptor family and appear to be a novel gene family. Further elucidation of the functions of PRARP and their origin might provide significant insights into the evolution of the immune system of jawed vertebrates., (Copyright © 2019 by The American Association of Immunologists, Inc.)

The plasmid-mediated transmission of antibiotic resistance genes has been reported to be involved in the development of antibiotic resistance in bacteria, and poses a serious threat for the success of bacterial infection treatment and human health worldwide. The present study used a 454 GS‑FLX pyrosequencing system to determine the ~140 kb nucleotide sequence of plasmid pHS36‑NDM, which was identified in a Salmonella Stanley isolate from the stool sample of an 11‑month‑old girl at Lishui Central Hospital, China, and which contains a New Delhi metallo‑β‑lactamase‑1 (NDM‑1) carbapenem resistance gene (blaNDM‑1). The 181 open reading frames encode proteins with functions including replication, stable inheritance, antibiotic resistance and mobile genetic elements. Both horizontal transfer and passage stability‑related genes were identified in pHS36‑NDM, including a conserved type 4 secretion system and stbA (stable plasmid inheritance protein A). Two multidrug resistance gene islands were identified: The ISEcp1‑blaCMY transposition unit which contains a CMY‑6 β‑lactamase gene (blaCMY‑6) and a quaternary ammonium compound resistance gene (sugE); and the intI1‑ISCR27 accessory region, which contained a trimethoprim resistance gene (dfrA12), two aminoglycoside resistance genes (aadA2 and rmtC), a truncated quaternary ammonium compound resistance gene (qacE∆1), a sulfonamide resistance gene (sul1), the blaNDM‑1 carbapenemase and a bleomycin resistance gene (bleMBL). pHS36‑NDM shared high homology with other blaNDM‑1‑containing plasmids reported in Sweden, Italy and Japan. However, no previous international travel history was documented for the patient and her family, even to neighboring cities. Furthermore, pHS36‑NDM is of a different incompatibility group to other published blaNDM‑1‑carrying plasmids reported in China, with low homology in the surrounding structure of blaNDM‑1. The present study will facilitate the understanding of the underlying resistance and dispersal mechanism of pHS36‑NDM, and will deepen our recognition of the ongoing spread of the blaNDM‑1‑containing plasmids.

As an increasingly common cause of skin infections worldwide, the prevalence of antibiotic-resistant Staphylococcus aureus ( S. aureus ) across China has not been well documented. This literature aims to study the resistance profile to commonly used antibiotics, including macrolides, fusidic acid (FA) and mupirocin, and its relationship to the genetic typing in 34 S. aureus strains, including 6 methicillin-resistant S. aureus (MRSA), isolated from a Chinese hospital. The MIC results showed 27 (79.4%), 1 (2.9%) and 6 (17.6%) isolates were resistant to macrolides, FA and mupirocin, respectively. Among 27 macrolide-resistant S. aureus isolates, 5 (18.5%) were also resistant to mupirocin and 1 (3.7%) to FA. A total of 13 available resistant genes were analyzed in 28 antibiotic-resistant strains using polymerase chain reaction (PCR). The positive rates of macrolide-resistant ermA , ermB , ermC , erm33 and low level mupirocin-resistant ileS mutations were 11.1%, 25.9%, 51.9%, 7.4% and 100%, respectively. Other determinants for FA- and high level mupirocin-resistance were not found. The results of multilocus sequence typing (MLST) and pulsed field gel electrophoresis (PFGE) revealed 13 sequence types (STs) and 18 clusters in 23 resistant gene positive S. aureus isolates. Among these STs, ST5 was most prevalent, accounting for 18.2%. Notably, various clusters were found with similar resistance phenotype and genotype, exhibiting a weak genetic relatedness and high genetic heterogeneities. In conclusion, macrolides, especially erythromycin, are not appropriate to treat skin infections caused by S. aureus , and more effective measures are required to reduce the dissemination of macrolides, FA and mupirocin resistance of the pathogen., Competing Interests: CONFLICTS OF INTEREST The authors declare that there are no competing interests regarding the publication of this paper.

The present study determined the role and mechanism of miR-138 in non-small cell lung cancer (NSCLC). In total, 45 freshly resected clinical NSCLC tissues were collected. The expression of miR-138 in tissues and cell lines were determined by real-time quantitative PCR. miR-138 mimics were transfected into A549 and Calu-3 cells in vitro, and then the effects of miR-138 on lung cancer cell proliferation, cell cycle, invasion and metastasis were investigated by CCK-8 assay, Transwell and flow cytometry, respectively. The protein expression of the potential target gene Sirt1 in lung cancer cells were determined by western blot analysis. Dual-luciferase reporter assay was performed to further confirm whether Sirt1 was the target gene of miR-138. The expression of miR-138 was significantly lower in lung cancer tissues and was negatively correlated to the differentiation degree and lymph node metastasis of lung cancer. In vitro experiment results showed that miR-138 inhibited lung cancer cell proliferation, invasion and migration. It was verified that miR-138 could downregulate Sirt1 protein expression, inhibit epithelial-mesenchymal transition (EMT), decrease the activity of AMPK signaling pathway and elevate mTOR phosphorylation level. Dual-luciferase reporter assay demonstrated that miR-138 could directly regulate Sirt1. Downregulation of Sirt1 alone can also cause the same molecular and biological function changes. Western blot analysis and confocal microscopy results indicated that overexpression of miR-138 or interference of Sirt1 expression could inhibit lung cancer cell autophagy activity possibly through AMPK-mTOR signaling pathway. miR-138 plays a tumor suppressor function in lung cancer. It may inhibit the proliferation, invasion and migration of lung cancer through downregulation of Sirt1 expression and activation of cell autophagy. The downregulation of miR-138 is closely related to the development of lung cancer.

Hypervirulent variants of Klebsiella pneumoniae (hvKp) that cause invasive community-acquired pyogenic liver abscess (PLA) have emerged globally. Little is known about the virulence determinants associated with hvKp, except for the virulence genes rmpA/A2 and siderophores ( iroBCD/iucABCD ) carried by the pK2044-like large virulence plasmid. Here, we collected most recent clinical isolates of hvKp from PLA samples in China, and performed clinical, molecular, and genomic sequencing analyses. We found that 90.9% (40/44) of the pathogens causing PLA were K. pneumoniae . Among the 40 LA-Kp, K1 (62.5%), and K2 (17.5%) were the dominant serotypes, and ST23 (47.5%) was the major sequence type. S1-PFGE analyses demonstrated that although 77.5% (31/40) of the LA-Kp isolates harbored a single large virulence plasmid varied in size, 5 (12.5%) isolates had no plasmid and 4 (10%) had two or three plasmids. Whole genome sequencing and comparative analysis of 3 LA-Kp and 3 non-LA-Kp identified 133 genes present only in LA-Kp. Further, large scale screening of the 133 genes in 45 LA-Kp and 103 non-LA-Kp genome sequences from public databases identified 30 genes that were highly associated with LA-Kp, including iroBCD, iucABCD and rmpA/A2 and 21 new genes. Then, these 21 new genes were analyzed in 40 LA-Kp and 86 non-LA-Kp clinical isolates collected in this study by PCR, showing that new genes were present 80-100% among LA-Kp isolates while 2-11% in K. pneumoniae isolates from sputum and urine. Several of the 21 genes have been proposed as virulence factors in other bacteria, such as the gene encoding SAM-dependent methyltransferase and pagO which protects bacteria from phagocytosis. Taken together, these genes are likely new virulence factors contributing to the hypervirulence phenotype of hvKp, and may deepen our understanding of virulence mechanism of hvKp.

Background: The occurrence of non-contiguous, multiple, and remote involvement tuberculous spondylitis is rare. The clinical presentation in patients with multifocal musculoskeletal tuberculosis may closely mimic that in patients with multiple bone metastases, which makes the accurate clinical diagnosis challenging. Herein, we report a multifocal musculoskeletal tuberculosis case that was misdiagnosed for 8 months as multiple bone metastases., Case Presentation: A 63-year-old male farmer of Chinese Han ethnicity presented to us with pain in left side of the neck, right side of the chest and the back for 10 months without typical tuberculosis symptoms. His past medical history, the CT and fluoroscopy-guided biopsy were negative for tuberculosis. Interferon gamma by T-SPOT was also negative. Radiological findings including CT, MRI and PET-CT suggested that the patient had multiple metastases. Accordingly, the patient was misdiagnosed as having musculoskeletal tumors until a swelling under the right nipple ulcerated. The smear test for acid-fast bacilli and the PCR test for TB-DNA of the pus from the swollen area were both positive, leading to the final correct diagnosis of musculoskeletal tuberculosis., Conclusion: The proper diagnosis of musculoskeletal tuberculosis is clinically challenging due to Mycobacterium tuberculosis variants involved and atypical presentations, especially when the lesions are multiple. Our findings indicate that multiple tuberculous spondylitis must be considered in the differential diagnosis of multiple musculoskeletal lesions.

Carbapenem-resistant Acinetobacter baumannii (CRAB) presents a serious therapeutic and infection control challenge. In this study, we investigated the epidemiological and molecular differences of CRAB and the threatening factors for contributing to increased CRAB infections at a hospital in western China. A total of 110 clinical isolates of A. baumannii, collected in a recent 2-year period, were tested for carbapenem antibiotic susceptibility, followed by a molecular analysis of carbapenemase genes. Genetic relatedness of the isolates was characterized by multilocus sequence typing. Sixty-seven of the 110 isolates (60.9%) were resistant to carbapenems, 80.60% (54/67) of which carried the bla OXA-23 gene. Most of these CRAB isolates (77.62%) were classified as clone complex 92 (CC92), and sequence type (ST) 92 was the most prevalent STs, followed by ST195, ST136, ST843, and ST75. One CRAB isolate of ST195 harbored plasmid pAB52 from a Chinese patient without travel history. This plasmid contains toxin-antitoxin elements related to adaptation for growth, which might have emerged as a common vehicle indirectly mediating the spread of OXA-23 in CRAB. Thus, CC92 A. baumannii carrying OXA-23 is a major drug-resistant strain spreading in China. Our findings indicate that rational application of antibiotics is indispensable for minimizing widespread of drug resistance.

Carbapenem-resistant Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, and Acinetobacter baumannii were isolated from a single patient, each producing different carbapenemases (NDM-1, KPC-2, IMP, and OXA-23, respectively). The NDM-1-producing E. coli strain was preceded by a clonally related carbapenem-susceptible strain a month earlier, suggesting in vivo acquisition of blaNDM-1., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)