Dendritic cell targeting peptide plus Salmonella FliCd flagellin fused outer membrane protein H (OmpH) demonstrated increased efficacy against infections caused by different Pasteurella multocida serogroups in mouse models.

As the major outer membrane protein (OMP) presents in the Pasteurella multocida envelope, OmpH was frequently expressed for laboratory assessments of its immunogenicity against P. multocida infections, but the results are not good. In this study, we modified OmpH with dendritic cell targeting peptide (Depeps) and/or Salmonella FliCd flagellin, and expressed three types of recombinant proteins with the MBP tag (rDepeps-FliC-OmpH-MBP, rDepeps-OmpH-MBP, rFliC-OmpH-MBP). Assessments in mouse models revealed that vaccination with rDepeps-FliC-OmpH-MBP, rDepeps-OmpH-MBP, or rFliC-OmpH-MBP induced significant higher level of antibodies as well as IFN-γ and IL-4 in murine sera than vaccination with rOmpH-MBP (P < 0.5). Vaccination with the three modified proteins also provided increased protection (rDepeps-FliC-OmpH-MBP, 70 %; rDepeps-OmpH-MBP, 50 %; rFliC-OmpH-MBP, 60 %) against P. multocida serotype D compared to vaccination with rOmpH-MBP (30 %). In mice vaccinated with different types of modified OmpHs, a significantly decreased bacterial strains were recovered from bloods, lungs, and spleens compared to rOmpH-MBP-vaccinated mice (P < 0.5). Notably, our assessments also demonstrated that vaccination with rDepeps-FliC-OmpH-MBP provided good protection against infections caused by a heterogeneous group of P. multocida serotypes (A, B, D). Our above findings indicate that modification with DCpep and Salmonella flagellin could be used as a promising strategy to improve vaccine effectiveness.

Computed tomography imaging and clinical characteristics of pulmonary ground-glass nodules ≤2 cm with micropapillary pattern.

BACKGROUND: The aim of this study was to investigate the imaging features, lymph node metastasis, and genetic mutations in micropapillary lung adenocarcinoma (imaging with mixed ground-glass nodules) ≤2 cm, to provide a more precise and refined basis for the selection of lung segment resection. METHODS: A retrospective analysis of 162 patients with surgically resected pathologically confirmed cancers ≤2.0 cm in diameter (50 cases of micropapillary mixed ground-glass nodules [mGGNs], 50 cases of nonmicropapillary mGGNs, and 62 cases of micropapillary SNs [solid nodules]) was performed. mGGNs were classified into five categories according to imaging features. The distribution of these five morphologies in micropapillary with mGGN and nonmicropapillary with mGGN was analyzed. The postoperative pathology and prognosis of lymph node metastasis were also compared between micropapillary mGGNs and micropapillary with SNs. After searching the TCGA database, we demonstrated heterogeneity, high malignancy and high risk of microcapillary lung cancer cancers. RESULTS: Different pathological subtypes of mGGN differed in morphological features (p < 0.05). The rate of lymph node metastasis was significantly higher in micropapillary mGGNs than in nonmicropapillary mGGNs. In the TCGA database samples, lactate transmembrane protein activity, collagen transcription score, and fibroblast EMT score were remarkably higher in micropapillary adenocarcinoma. Other pathological subtypes had a better survival prognosis and longer disease-free survival compared with micropapillary adenocarcinoma. CONCLUSION: mGGNs ≤2 cm with a micropapillary pattern have a higher risk of lymph node metastasis compared with SNs, and computed tomography (CT) imaging features can assist in their diagnosis.

Treatment of a patient with severe lactic acidosis and multiple organ failure due to mitochondrial myopathy: A case report.

BACKGROUND: Mitochondrial myopathy is a rare genetic disease with maternal inheritance that may involve multiple organ systems. Due to the lack of typical characteristics, its clinical diagnosis is difficult, and it is often misdiagnosed or even missed. CASE SUMMARY: The patient was a young college student. When he presented at the hospital, he had severe lactic acidosis, respiratory failure, and shock with multiple organ dysfunction syndrome (MODS). He was treated by mechanical ventilation, veno-arterial extracorporeal membrane oxygenation, and other organ support. However, his condition continued to worsen. After a thorough and detailed medical and family history was taken, a mitochondrial crisis was suspected. A muscle biopsy was taken. Further genetic testing confirmed a mitochondrial gene mutation (TRNL1 3243A>G). The final diagnosis of mitochondrial myopathy was made. Although there is no known specific treatment, intravenous methylprednisone and intravenous immunoglobulin were started. The patient's shock eventually improved. The further course was complicated by severe infection in multiple sites, severe muscle weakness, and recurrent MODS. After 2 mo of multidisciplinary management and intensive rehabilitation, the patient could walk with assistance 4 mo after admission and walk independently 6 mo after admission. CONCLUSION: More attention should be paid to mitochondrial myopathy to avoid missed diagnosis and misdiagnosis.

Elderly onset of MELAS in a male: A case report.

Background: Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is one of the most common maternally inherited mitochondrial diseases which rarely affects elderly people. Case presentation: We reported the case of a 61-year-old male patient with MELAS. He was experiencing acute migraine-like headaches as the first symptoms. Laboratory data showed elevated lactate and creatine kinase levels. Brain magnetic resonance imaging (MRI) found a high signal intensity lesion in the left occipital-temporal-parietal lobe on diffusion-weighted imaging (DWI). Magnetic resonance angiography (MRA) revealed reversible vasoconstriction of the middle cerebral arteries and superficial temporal arteries. A muscle biopsy suggested minor muscle damage. A genetic study revealed a mitochondrial DNA A3243G mutation. Conclusion: Elderly onset of MELAS is rare and easily misdiagnosed as an ischemic stroke. MELAS with the onset of stroke-like episodes should be considered in adult or elderly patients with imaging findings that are atypical for cerebral infarction. The use of multimodal MRI in the clinical diagnosis of MELAS could be extremely beneficial.

Expression and clinical significance of CD31, CD34, and CD105 in pulmonary ground glass nodules with different vascular manifestations on CT.

Blood vessel passage on CT exerts a vital part in early diagnosis as well as treatment of carcinoma of the lungs. Intratumoral microvascular density (iMVD) has gradually become the focus of research on biological behavior, appearance, and evolution of malignant tumors nowadays. The aim of this paper was to verify whether there is a correlation between the iMVD and the vascular morphology of ground glass nodules (GGNs). A total of 109 patients with pulmonary GGN were classified into three groups (I,II, and III) according to the vascular morphology on CT, and their expression of CD31-, CD34-, and CD105-labeled iMVD was detected by the streptoavidin-biotin method, statistically analyzing the iMVD values of each group. The expression of CD31, CD34, and CD105 in different lung tissues was significantly different, with remarkably higher iMVD in lung cancer tissues than in adjacent normal lung tissues. In the imaging sort of types I, II, and III according to the means of vascular passage, the iMVD expression of CD31, CD34, and CD105 was significantly different between groups. These data suggest that the presence and the abnormal morphology of vessels seen within GGNs indicate the occurrence and progression of lung cancer in pathology. It offers a strong theoretical foundation for early diagnosis of carcinoma of the lungs, thus providing a more precise clinical diagnosis and prognosis of early-stage lung cancer.

A patient with hereditary transthyretin amyloidosis involving multiple cranial nerves due to a rare p.(Phe84Ser) variant.

We report a 30-year-old man involving gastrointestinal symptoms, vitreous opacity, and multiple cranial neuropathies. Transthyretin-related hereditary amyloidosis genetic testing revealed a rare c.251T > C variant p.(Phe84Ser). Only four cases with this variant have been reported before.

Causes and predictors of mortality from lupus nephritis in Southern Hunan, China.

OBJECTIVES: The objective of the study was to explore the causes and predictors of mortality in a cohort of LN with LN in southern Hunan, China. METHODS: We analyzed 236 patients with biopsy-proven LN during 2010-2018. Demographic data, laboratory data, SLEDAI scores, treatment strategies, and comorbidity were collected. Cox regression analysis was carried out to determine the independent predictors of mortality. RESULTS: The patients had mean disease duration of 67.9 ± 28.2 months. Class IV LN was the predominant biopsy class within the cohort (38.1%). After 1 year therapy, the majority of patients achieved complete remission (72.9%) and 44 (18.6%) patients achieved partial remission. The 5- and 10-years survival rates for our cohort were 94.4 and 85.2%, respectively. There were 18 deaths (7.6%), of which the main causes were infection (50%) alone and cardiovascular diseases (27.8%). Independent predictors of mortality in our cohort were: platelet-to-neutrophil ratio (PNR) [hazard ratio (HR) 5.910; confidence interval (CI) 1.253-27.875], onset age (HR 1.090; CI 1.035-1.147), and SLEDAI scores (HR 1.258; CI 1.068-1.482). CONCLUSION: We firstly revealed that PNR might be a promising predictor of mortality and reported the causes and prognostic predictors of mortality in LN from southern Hunan, China.

Regulation of PCSK9 Expression and Function: Mechanisms and Therapeutic Implications.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) promotes degradation of low-density lipoprotein receptor (LDLR) and plays a central role in regulating plasma levels of LDL cholesterol levels, lipoprotein(a) and triglyceride-rich lipoproteins, increasing the risk of cardiovascular disease. Additionally, PCSK9 promotes degradation of major histocompatibility protein class I and reduces intratumoral infiltration of cytotoxic T cells. Inhibition of PCSK9 increases expression of LDLR, thereby reducing plasma levels of lipoproteins and the risk of cardiovascular disease. PCSK9 inhibition also increases cell surface levels of major histocompatibility protein class I in cancer cells and suppresses tumor growth. Therefore, PCSK9 plays a vital role in the pathogenesis of cardiovascular disease and cancer, the top two causes of morbidity and mortality worldwide. Monoclonal anti-PCSK9 antibody-based therapy is currently the only available treatment that can effectively reduce plasma LDL-C levels and suppress tumor growth. However, high expenses limit their widespread use. PCSK9 promotes lysosomal degradation of its substrates, but the detailed molecular mechanism by which PCSK9 promotes degradation of its substrates is not completely understood, impeding the development of more cost-effective alternative strategies to inhibit PCSK9. Here, we review our current understanding of PCSK9 and focus on the regulation of its expression and functions.

Transcriptome Differences in Pig Tracheal Epithelial Cells in Response to Pasteurella Multocida Infection.

Pasteurella multocida generally colonizes mammalian/bird respiratory tracts and mainly causes respiratory disorders in both humans and animals. To date, the effects of P. multocida infection on the respiratory epithelial barriers and molecules in host respiratory epithelial cells in their response to P. multocida infection are still not well-known. In this study, we used newborn pig tracheal epithelial (NPTr) cells as an in vitro model to investigate the effect of P. multocida infection on host respiratory epithelial barriers. By detecting the transepithelial electrical resistance (TEER) values of NPTr cells and the expression of several known molecules associated with cell adherens and junctions, we found that P. multocida infection disrupted the barrier functions of NPTr cells. By performing RNA sequencing (RNA-Seq), we determined 30 differentially expressed genes (DEGs), including the vascular endothelial growth factor A (VEGFA) encoding gene VEGFA, which participated in biological processes (GO:0034330, GO:0045216, and GO:0098609) closely related to epithelial adhesion and barrier functions. These 30 DEGs participated in 22 significant signaling pathways with a p-value < 0.05, including the transforming growth factor (TGF)-beta signaling pathway (KEGG ID: ssc04350), hypoxia-inducible factor 1 (HIF-1) signaling pathway (KEGG ID: ssc04066), epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor resistance (KEGG ID: ssc01521), tumor necrosis factor (TNF) signaling pathway (KEGG ID: ssc04668), and mitogen-activated protein kinase (MAPK) signaling pathway (KEGG ID: ssc04010), which are reported to have roles in contributing to the production of inflammatory factors as well as the regulation of epithelial adhesion and barrier function in other tissues and organisms. The results presented in this study may help improve our understanding of the pathogenesis of P. multocida.

Hsa_circ_0016788 regulates hepatocellular carcinoma progression via miR-506-3p/poly-adenosine diphosphate-ribose polymerase.

BACKGROUND AND AIM: Hepatocellular carcinoma (HCC) is a common malignant tumor worldwide. Recent researches have shown that circular RNAs (circRNAs) could affect the progress of HCC, but the mechanism is still indistinct. In this work, we explored the roles of circRNA_0016788 in HCC. METHODS: The levels of hsa_circ_0016788, microRNA-506-3p (miR-506-3p), and mRNA of poly-adenosine diphosphate-ribose polymerase, member 14 (PARP14) were detected by quantitative real-time reverse transcription-polymerase chain reaction in HCC tissues. Meanwhile, the level of PARP14 was quantified by Western blot analysis. Besides, the cell functions were examined by commercial kit, Cell Counting Kit-8 assay, EdU assay, colony formation assay, flow cytometry assay, Western blot, and transwell assay. Furthermore, the interplay between miR-506-3p and hsa_circ_0016788 or PARP14 was detected by dual-luciferase reporter assay. Eventually, the in vivo experiments were applied to measure the role of hsa_circ_0016788. RESULTS: The levels of hsa_circ_0016788 and PARP14 were upregulated, and the miR-506-3p level was decreased in HCC tissues in contrast to that in normal tissues. For functional analysis, hsa_circ_0016788 deficiency inhibited cell glycolysis metabolism, cell vitality, cell proliferation, colony formation, and invasion in HCC cells whereas promoted cell apoptosis. Moreover, miR-506-3p was confirmed to repress the progression of HCC cells by suppressing PARP14. In mechanism, hsa_circ_0016788 acted as a miR-506-3p sponge to regulate the level of PARP14. In addition, hsa_circ_0016788 knockdown also inhibited tumor growth in vivo. CONCLUSION: Hsa_circ_0016788 facilitates the development of HCC through increasing PARP14 expression by regulating miR-506-3p, which also offered an underlying targeted therapy for HCC treatment.

Screening and clinical significance of lymph node metastasis-related genes within esophagogastric junction adenocarcinoma.

BACKGROUND: Despite recent improvements in treatment technologies, such as surgical resection and chemoradiotherapy, the prognosis of patients with esophagogastric junction adenocarcinoma (EJA) remains poor due to early lymph node metastasis. Since few studies have investigated genes associated with lymph node metastasis in EJA, we aimed to screen lymph node metastasis-associated genes and clarify their expression status and prognostic significance in EJA. METHODS: The differential frequency of mutations between carcinoma and para-carcinoma tissues from 199 cases with EJA was detected using targeted next-generation sequencing (tNGS). Following a stratified analysis to determine that gender has no effect on the frequency of gene mutations, lymph node metastasis-related genes, including CDK6, MET, NOTCH1, and LRP1B, were screened, and CDK6 and LRP1B were selected for further study as they displayed significant differences in mutation rates. Differences in their expression status were verified using immunohistochemical (IHC) staining in 18 CDK6- and 17 LRP1B-mutated samples and a randomly matched control group. RESULTS: tNGS revealed that CDK6 and LRP1B mutation frequencies were significantly different between EJA cases with (N ≥ 1) or without (N = 0) lymph node metastasis. In particular, CDK6 mutation frequency was expected less, whereas that of LRP1B was remarkably higher in cases with stage N0 than in those with stage N ≥ 1. IHC staining confirmed significant differences in CDK6 and LRP1B expression status between the study and control cohorts. Chi-square tests revealed that a high CDK6 expression status correlated significantly with smoking history (p = 0.044), T stage (p = 0.035), N stage (p = 0.000), and advanced TNM stage (p = 0.001) in EJA, whereas a high LRP1B expression status only correlated with BMI (p = 0.013) and N stage (p = 0.000). Furthermore, as confirmed by survival status investigation, a high LRP1B expression status predicted good prognosis, and a high CDK6 expression status was an independent predictor of poor prognosis in patients with EJA. CONCLUSIONS: Taken together, the findings of this study demonstrate that a high CDK6 and LRP1B expression status promotes and inhibits lymph node metastasis in patients with EJA, respectively, suggesting that both CDK6 and LRP1B are significantly potential predictors of lymph node metastasis and prognosis in EJA.

Existing knowledge on Euphorbia fischeriana Steud. (Euphorbiaceae): Traditional uses, clinical applications, phytochemistry, pharmacology and toxicology.

ETHNOPHARMACOLOGICAL RELEVANCE: Euphorbia fischeriana Steud. (Euphorbiaceae) is a perennial herb distributed in grassland, hill slopes or gravel hillside, with average altitude of 100-600 m. The whole grass of E. fischeriana is toxic with roots used as folk medicine to treat Zhushui, dyspepsia, abdominal distension, abdominal pain, cough, as well as external applications such as cure of scabies and tuberculosis of lymph nodes. AIM OF THE REVIEW: This systematic review aims to provide a detailed and in-depth summary about the reported advances in traditional uses, clinical applications, phytochemistry, pharmacology and toxicity of E. fischeriana, so as to offer fresh ideas and broader vision and insights for subsequent studies. MATERIALS AND METHODS: Various scientific data bases such as CNKI, Elsevier, Google Scholar, Pubmed, Science Direct, SciFinder Scholar and Web of Science were searched to collect information about E. fischeriana. Other relevant literatures were searched in 'Flora of China Editorial Committee', ancient books, Ph.D and Masters' Dissertation to get more data of E. fischeriana. RESULTS: A total of 241 chemical constituents have been identified from the roots of E. fischeriana, including diterpenoids, triterpenoids, meroterpenoids, acetophenones, flavonoids, coumarins, steroids, phenolic acids, tannins, etc. Various pharmacological activities have been demonstrated, especially anti-tumor, antibacterial, anti-inflammatory, antiviral and anti-leukemia activities. Moreover, different investigations about clinical uses and toxicology of E. fischeriana indicated that attention should be paid to its usage and dosage. CONCLUSION: The researches of E. fischeriana are excellent, but gap still remains. As a poisonous traditional Chinese medicine, there are not enough studies on the toxicity of E. fischeriana. In addition, scholars' research on the pharmacological mechanism of E. fischeriana focuses more on the anti-tumor activity, which can be broadened in the future. Presumably, chemical constituents and biological activities of diterpenoids and trace meroterpenoids in E. fischeriana deserve further research in-depth in the future, in order to provide low toxicity and high efficiency lead compounds. Meanwhile, further studies on other medicinal aspects may lay a foundation for the comprehensive development and utilization of E. fischeriana.

Comparison of the effectiveness of autologous grafts for anterior cruciate ligament reconstruction: A protocol for an overview of systematic review and network meta-analysis.

BACKGROUND: Anterior cruciate ligament rupture is a common motor system injury, and the most effective treatment is anterior cruciate ligament reconstruction (ACLR). Choosing the right graft is an important factor to ensure the success of the surgery. Current research shows that the clinical effect of autologous ligaments is better than that of allogeneic ligaments and artificial ligaments. However, there are differences between the autogenous ligaments, and how to choose them is still controversial. This study evaluated the published systematic reviews on the efficacy of different autologous ligament grafts in ACLR, and based on this, conducted a network meta-analysis of related randomized controlled trials. METHODS: We searched 8 international and Chinese databases including PubMed, Embase, Web of Science, and Cochrane Library. The methodological quality of systematic reviews will be evaluated by Assessing the Methodological Quality of Systematic Reviews-2 (AMSTAR2) measurement tool. Cochrane's risk of bias tool will be used to assess the risk of bias of included randomized controlled trials, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach will be used to evaluate the evidence quality. Network meta-analysis will be applied to evaluate the therapeutic effect of different autologous grafts. The main outcome measures are IKDC score, clinical failure rate, Lachman test, Lysholm score, and the incidence of complications. Odds ratio and its 95% confidence interval will be used to synthesize the dichotomy results, while the mean difference and 95% confidence interval of continuous variables will be used for continuous variables. RESULTS: This study will provide comprehensive evidence for the application of autologous grafts in ACLR. CONCLUSION: The results of this study will help clinicians make appropriate decisions. PROTOCOL REGISTRATION NUMBER: INPLASY202090061.

Gas identification in high-Q microbubble resonators.

A new, to the best of our knowledge, experimental mechanism is reported to realize the identification of gas by a microcavity sensor. Instead of measuring the change in the environment refractive index or absorption, the gas is detected indirectly and indentified by using the thermo-optics effect of a high-quality-factor microbubble resonator. When passing gas through the microbubble, the pressure induces a geometric deformation and thus an observable frequency shift, and the thermal bistability response varies due to the higher heat dissipation by gas molecules. With the two output parameters, we can unambiguously distinguish gas with different molecular weights, e.g., He, N2, and CO2. Our demonstration opens a new avenue of microcavity sensing by using indirect interaction between light and matter, realizing a multiple-parameter sensing approach for gas or solvent identification.

The R2R3-MYB transcription factor CsMYB73 negatively regulates l-Theanine biosynthesis in tea plants (Camellia sinensis L.).

l-Theanine, a non-proteinaceous amino acid abundantly present in tea (Camellia sinensis), contributes to the umami flavor of tea and has beneficial effects on human health. While key l-theanine biosynthetic genes have been well documented, their transcriptional regulation remains poorly understood. In this study, we determined the l-theanine contents in tea leaves of two cultivars at three developmental stages and investigated the expression patterns of the l-theanine biosynthetic genes CsGS1 and CsGS2. Additionally, we identified an R2R3-MYB transcription factor, CsMYB73, belonging to subgroup 22 of the R2R3-MYB family. CsMYB73 expression negatively correlated with l-theanine accumulation during leaf maturation. We found that CsMYB73, as a nuclear protein, binds to the promoter regions of CsGS1 and CsGS2 via MYB recognition sequences and represses the transcription of CsGS1 and CsGS2 in tobacco leaves. Collectively, our results demonstrate that CsMYB73 is a transcriptional repressor involved in l-theanine biosynthesis in tea plants. Our findings might contribute to future tea plant breeding strategies.

The arterial-ligation-alone method for identifying the intersegmental plane during thoracoscopic anatomic segmentectomy.

BACKGROUND: Currently, methods for identifying the intersegmental plane during anatomical segmentectomy can be classified into 2 categories: the bronchial method and the vascular method. One of the vascular methods, the arterial-ligation-alone method, has not yet been validated or objectively evaluated in a large case series. We thus aimed to confirm that the arterial-ligation-alone method could effectively and accurately identify the intersegmental plane. METHODS: We retrospectively reviewed the records of 104 patients who were scheduled for thoracoscopic anatomic segmentectomy. Preoperative three-dimensional (3D) reconstruction was performed on all the affected lungs to distinguish the targeted segmental arteries, veins and bronchi. The procedure was as follows: first, based on the 3D reconstruction of the lung, the targeted segmental arteries were distinguished and ligated. Second, bilateral pulmonary ventilation was performed with pure oxygen. When the affected lung had completely inflated, contralateral pulmonary ventilation was performed. After waiting for some time, the first intersegmental plane could be obtained, and the time was recorded as T1, with an electric coagulation hook being used for marking. Thirdly, when the targeted segmental veins and bronchi had been ligated, the second intersegmental plane could be obtained by the inflation-deflation method as before, with the waiting time being recorded as T2. The differences between the 2 intersegmental planes were evaluated by 2 experienced chief thoracic surgeons. RESULT: In a total of 99 (95.2%) patients, the intersegmental planes were successfully and accurately identified by the arterial-ligation-alone method. Ultimately, 85 (81.7%) patients underwent thoracoscopic anatomic segmentectomy. The results for evaluating the differences between the 2 planes were as follows: completely consistent (94 cases, 94.9%), basically consistent (5 cases, 5.1%), and discrepant (0 cases, 0%). The mean T1 was 13.6±2.7 minutes (range, 8-25 minutes), and the mean T2 was 13.0±2.6 minutes (range, 8-23 minutes), with P=0.100 (95% CI). For 99 patients, the mean nodule size was 1.1±0.34 cm. In the 85 patients who underwent segmentectomy, the mean margin width was 2.84±0.51 cm, the mean operative duration was 165.6±18.3 minutes, the mean operative hemorrhage was 52.1±20.2 mL, and the mean duration of chest tube drainage was 3.9±1.3 days. Postoperative complications related to operative procedures occurred in 2 cases. CONCLUSIONS: The arterial-ligation-only method can effectively, accurately and inexpensively identify the intersegmental plane, and is especially suitable for the patients whose veins or bronchi are difficult to anatomize. Whether the target bronchus is ligated has no effect on the intersegmental plane.

Epidemiological and genetic characteristics of porcine reproduction and respiratory syndrome virus 2 in mainland China, 2017-2018.

Porcine reproductive and respiratory syndrome virus 2 (PRRSV2) is a major threat to the global pig industry, particularly in China, the world's largest pig-rearing and pork-production country. Continuously monitoring the epidemiological and genetic characteristics of PRRSV epidemic strains is beneficial for prevention and control of infection. Previously, we reported the epidemiological and genetic characteristics of PRRSV2 in China from 2012 to 2016. Here, the epidemiological and genetic characteristics of PRRSV2 in China from 2017 to 2018 are reported. During these two years, we collected different types of porcine samples from 2428 pig farms in 27 provinces in China. Of the 7980 samples collected, 2080 (26.07%) were positive for PRRSV2 ORF5 by RT-PCR. The positive rate of PRRSV detection between different regions of China ranged from 8.12% to 29.33%, and from 7.96% to 55.50% between different months. Phylogenetic analysis based on the ORF5 gene revealed that the PRRSV2 strains currently circulating in China belong to five clades, and most of the PRRSVs detected are highly pathogenic PRRSVs (HP-PRRSVs; clade IV) and PRRSV NADC30-like strains (clade I). Sequence analysis revealed multiple amino acid mutation types, including amino acid changes and deletions in both the GP5 and Nsp2 proteins. The presence of these mutations may have an effect on the evolution of the virus by altering the viral titer and/or affecting the antibody response against the virus.

Slowing of the Time Course of Acidification Decreases the Acid-Sensing Ion Channel 1a Current Amplitude and Modulates Action Potential Firing in Neurons.

Acid-sensing ion channels (ASICs) are H+-activated neuronal Na+ channels. They are involved in fear behavior, learning, neurodegeneration after ischemic stroke and in pain sensation. ASIC activation has so far been studied only with fast pH changes, although the pH changes associated with many roles of ASICs are slow. It is currently not known whether slow pH changes can open ASICs at all. Here, we investigated to which extent slow pH changes can activate ASIC1a channels and induce action potential signaling. To this end, ASIC1a current amplitudes and charge transport in transfected Chinese hamster ovary cells, and ASIC-mediated action potential signaling in cultured cortical neurons were measured in response to defined pH ramps of 1-40 s duration from pH 7.4 to pH 6.6 or 6.0. A kinetic model of the ASIC1a current was developed and integrated into the Hodgkin-Huxley action potential model. Interestingly, whereas the ASIC1a current amplitude decreased with slower pH ramps, action potential firing was higher upon intermediate than fast acidification in cortical neurons. Indeed, fast pH changes (<4 s) induced short action potential bursts, while pH changes of intermediate speed (4-10 s) induced longer bursts. Slower pH changes (>10 s) did in many experiments not generate action potentials. Computer simulations corroborated these observations. We provide here the first description of ASIC function in response to defined slow pH changes. Our study shows that ASIC1a currents, and neuronal activity induced by ASIC1a currents, strongly depend on the speed of pH changes. Importantly, with pH changes that take >10 s to complete, ASIC1a activation is inefficient. Therefore, it is likely that currently unknown modulatory mechanisms allow ASIC activity in situations such as ischemia and inflammation.

Characteristics of a Colistin-Resistant Escherichia coli ST695 Harboring the Chromosomally-Encoded mcr-1 Gene.

Enterobacteriaceae having chromosomally-encoded mcr-1 is rarely reported. In this study, we recovered a chromosomal mcr-1 carrying Escherichia coli, designated HeN100, from the feces of a diarrheal pig in China. Antimicrobial susceptibility testing showed that HeN100 was resistant to three aminoglycosides, twelve ß-lactams including three carbapenems, one phenicol, two tetracyclines, two fluoroquinolones, nitrofurantoin, and colistin tested. Oxford Nanopore MinION sequencing revealed that the complete genomes of the multidrug resistant (MDR) HeN100 consisted of a single circular chromosome and five circular plasmids. Bioinformatical analysis determined HeN100 as ST695 and it contained many acquired resistance genes responsible for its MDR phenotypes, including colistin resistance mcr-1 and the carbapenem resistance blaNDM-1, and most of these genes were located on plasmids. However, the mcr-1 was found on the chromosome, and it was located between an IS30-like element ISApl1 and a PAP2-like encoding gene. These three genes consisted of an "ISApl1-mcr-1-orf" segment and inserted in high AT-rich regions. Finally, we found the blaNDM-1 was carried on an IncFII type conjugative plasmid. The conjugation frequency of this plasmid was 7.61 ± 2.11 × 10-5 per recipient, and its conjugation conferred resistance to carbapenems and other ß-lactams, as well as aminoglycosides. The spread of this mcr-1/blaNDM-1-carrying E. coli ST695 represents a great concern of public health.

Enterococcus faecium NCIMB 10415 supplementation improves the meat quality and antioxidant capacity of muscle of broilers.

The present study was conducted to investigate the effects of Enterococcus faecium (E. faecium) on the meat quality and antioxidant capacity of muscle in broilers. A total of 600 Arbor Acre broiler chickens (1-day-old, male) were randomly divided into five treatments with six replicates (20 chickens per replicate) for each treatment. The five treatments were the control treatment (CON, basal diet), antibiotic treatment (ANT, basal diet supplemented with 0.1% chlortetracycline) and E. faecium-supplemented treatments (LEF, MEF and HEF, basal diet supplemented with 50, 100 and 200 mg/kg of E. faecium respectively). The experiment lasted 42 days in two periods of 21 days. Results showed that there were no differences in breast meat quality among different treatments (p > 0.05). Compared with the CON and ANT treatments, the yellowness of thigh meat in E. faecium-supplemented treatments was significantly increased (p < 0.05); the shear force of thigh meat in the LEF and MEF treatments was lower than that of the CON treatment (p < 0.05). In addition, the concentration of the inosine monophosphate (IMP) in the breast and thigh meat of the MEF treatment was significantly higher than that of the other treatments (p < 0.05). At 21 days, the total antioxidant capability (T-AOC) level and glutathione peroxidase (GSH-Px) activity of breast meat and superoxide dismutase (SOD) in the thigh meat of the MEF treatment were greatly increased (p < 0.05). At 42 days of age, the catalase (CAT), GSH-Px and T-AOC activities in the breast meat of the MEF treatment were increased (p < 0.05) and the CAT activity of thigh meat in the LEF and MEF treatments was increased (p < 0.05). In conclusion, E. faecium supplementation increased the meat quality of the thigh muscle, increased the IMP content and the activities of CAT, SOD, T-AOC, and GSH-Px of muscle in broilers. Supplementation with 100 mg/kg E. faecium had the greatest effects.