TcpC inhibits toll-like receptor signaling pathway by serving as an E3 ubiquitin ligase that promotes degradation of myeloid differentiation factor 88.

TcpC is a virulence factor of uropathogenic E. coli (UPEC). It was found that TIR domain of TcpC impedes TLR signaling by direct association with MyD88. It has been a long-standing question whether bacterial pathogens have evolved a mechanism to manipulate MyD88 degradation by ubiquitin-proteasome pathway. Here, we show that TcpC is a MyD88-targeted E3 ubiquitin ligase. Kidney macrophages from mice with pyelonephritis induced by TcpC-secreting UPEC showed significantly decreased MyD88 protein levels. Recombinant TcpC (rTcpC) dose-dependently inhibited protein but not mRNA levels of MyD88 in macrophages. Moreover, rTcpC significantly promoted MyD88 ubiquitination and accumulation in proteasomes in macrophages. Cys12 and Trp106 in TcpC are crucial amino acids in maintaining its E3 activity. Therefore, TcpC blocks TLR signaling pathway by degradation of MyD88 through ubiquitin-proteasome system. Our findings provide not only a novel biochemical mechanism underlying TcpC-medicated immune evasion, but also the first example that bacterial pathogens inhibit MyD88-mediated signaling pathway by virulence factors that function as E3 ubiquitin ligase.

All-normal dispersion widely tunable dual-wavelength mode-locked fiber laser based on NALM.

We experimentally and numerically demonstrate the all-normal dispersion (ANDi) ytterbium (Yb)-doped fiber laser based on nonlinear amplifying loop mirror (NALM) mode-locked, which allows tunable single-wavelength and dual-wavelength outputs. The pulses tuning ranges of the dual-wavelength are from 1032.24 nm to 1053.13 nm and from 1047.94 nm to 1069.05 nm, and the repetition frequency difference varies from 1766Hz to 1834Hz. To our knowledge, this is the widest dual-wavelength tuning range of Yb-doped fiber lasers based on NALM mode-locked. We test for 90 minutes and have high stability in both single-wavelength and dual-wavelength. In addition, the pulsed collision dynamics between two solitons at different wavelengths are numerically studied. Numerical results show that during the pulse collision, the two solitons pass through each other and maintain their properties, which also confirms the particle nature of the isolated wave. Our research contributes to the dynamics of dual-wavelength solitons collision in NALM mode-locked fiber laser and provides what we believe to be is a new idea for tunable Yb-doped dual-comb sources.

First report of Fusarium cugenangense causing root rot of tea plants (Camellia sinensis) in China.

Root rot is an important disease of tea plants owing to its unobvious early symptoms and permanent damage (Huu et al. 2016). In 2019, 5% of tea plants displayed symptoms consistent with root rot in a tea plantation (28°09'N, 113°13'E) located in Changsha city, Hunan province of China. The symptoms of the diseased tea plants ranged from wilting leaves to entirely dead. The roots had black lesions and rot typical of this disease. Symptomatic roots were collected, washed with water and disinfected with 75% ethanol, then cut into pieces and sterilized with 0.1% mercuric chloride for 30 s, 75% ethanol for 1 min, and rinsed with sterile water five times. After drying on sterilized filter paper, root tissues were cultured on potato dextrose agar (PDA) medium at 25 oC for 7 days in the dark. Four isolates, CAGF1, CAGF2, CAGF3, and CAGF4 were purified by selecting single spores. All isolates were subjected to a pathogenicity test. A conidial suspension of each strain was collected at a concentration of 2×106 conidia/mL. For the pathogenicity test, two-year-old field grown tea plants were transplanted in plastic pots containing 240 g of the rice grain-bran mixture (inoculated with 4 mL of conidial suspension and cultured for 14 days) and 960 g of sterilized soil (Huu et al. 2016). The pots without inoculated mixture served as control group. All the pots were kept in illumination incubators at 25 oC and a 12L:12D photoperiod. The pathogenicity test for each strain was repeated three times with three repetitions. Only strain CAGF1 exhibited pathogenicity to tea plants. Symptoms appeared on the third day post inoculation (dpi) and gradually worsened by the 7 dpi. On the 14 dpi, most leaves had died and the roots were black and partially rotten, similar to field symptoms. The reisolated fungus from potted roots was identified as CAGF1 based on ITS region and colony morphology, while isolation was attempted, CAGF1 was not isolated from the control plants, which fulfilled Koch's postulates. On PDA, the colony center of CAGF1 was purple with white margin, while on carnation leaf agar (CLA) medium was white. On CLA medium, macroconidia have 0 to 3 septa, measured 19.1 µm to 41.2 µm × 4.2 µm to 5.4 µm (mean= 31.2 µm × 4.8 µm, n=30). The microconidia were measured as 6.7 µm to 12.8 µm × 2.4 µm to 4.9 µm (mean= 10.1 µm × 3.3 µm, n=30), with 0 to 1 septa. And the chlamydospores were measured as 6.0 to 9.7µm (mean= 7.7µm, n=30). Morphologically, strain CAGF1 was identified as Fusarium oxysporum (Leslie and Summerell 2006). Additionally, the genomic DNA of strain CAGF1 was extracted by cetyltrimethylammonium bromide (CTAB) method, the internal transcribed spacer (ITS), elongation factor 1 alpha (EF-1α) and second largest subunit of RNA polymerase II (RPB2) were amplified using the primers ITS1/ITS4 (White et al. 1990), EF-1/EF-2 (Geiser et al. 2004) and fRPB2-5F/fRPB2-7cR (Liu et al. 1999), respectively. Sequences were deposited in GenBank (ITS, OK178562.1; EF-1α, OK598121.1; RPB2, OP381476.1). BLASTn searches revealed that strain CAGF1 was 100% (ON075522.1 for ITS and JX885464.1 for RPB2) and 99.6% (JQ965440.1 for EF-1α) identical to Fusarium oxysporum species complex (FOSC). Based on phylogenetic analysis, the strain CAGF1 was identified as Fusarium cugenangense, belonging to FOSC. To our knowledge, this is the first report of F. cugenangense causing root rot of tea plants in China. The findings are important for the management of this root rot and the improvement of economic benefits of tea cultivation.

[Validity of the Inpatient Satisfaction Questionnaire].

OBJECTIVE: To assess the validity of the self-designed inpatient satisfaction questionnaire using Structural Equation Model (SEM). METHODS: The questionnaire survey was conducted in a tertiary hospital in Sichuan in April 2016,with participants selected through a systematical sampling approach. The structural validity of the inpatient satisfaction questionnaire was assessed using SEM. The statistical analyses were performed using Lisrel8.70. RESULTS: About 98.5% of returned questionnaires were valid for data analyses,which resulted in a total sample of 2562. A good model fit was achieved: df=8.36,root mean square error of appoximation (RMSEA)=0.054,root mean square residual (RMR)=0.021,goodness-of-fit index (GFI)=0.93,adjusted GFI (AGFI)=0.91,com-parative fit index (CFI)=0.98,non-normed fit index (NNFI)=0.98,parsimony GFI(PGFI) =0.74. Factor loadings on exogenous latent variables ranged from 0.59 to 0.94,with 0.52-0.87 AVE. CONCLUSION: The questionnaire has a good construct validity,which can be used for evaluating inpatient satisfaction in tertiary hospitals.

Sequencing of cerebrospinal fluid cell-free DNA facilitated early differential diagnosis of intramedullary spinal cord tumors.

Pre-surgery differential diagnosis is valuable for personalized treatment planning in intramedullary spinal cord tumors. This study assessed the performance of sequencing cell-free DNA (cfDNA) in cerebrospinal fluid (CSF) for differential diagnosis of these tumors. Prospectively enrolling 45 patients with intramedullary spinal cord lesions, including diffuse midline glioma (DMG), H3K27-altered (14/45), glioblastoma (1/45), H3-wildtype-astrocytoma (10/45), ependymoma (11/45), and other lesions (9/45), CSF samples were collected via lumbar puncture (41/45), intraoperative extraction (3/45), and Ommaya reservoir (1/45). Then, these samples underwent targeted sequencing along with paired tissue DNA. DMG, H3K27-altered patients exhibited a higher ctDNA positivity (85.7%, 12/14) compared to patients with H3-wildtype-astrocytoma (0/8, P = 0.0003), ependymoma (2/10, P = 0.003), and glioneuronal tumor (0/3, P = 0.009). The histological-grade-IV (P = 0.0027), Ki-67 index ≥10% (P = 0.014), and tumor reaching spinal cord surface (P = 0.012) are also associated with higher ctDNA positivity. Interestingly, for patients with TERT promoter mutant tumors, TERT mutation was detectable in the CSF cfDNA of one DMG case, but not other five cases with histological-grade-II tumors. Shared copy number variants were exclusively observed in DMG, H3K27-altered, and showed a strong correlation (Correlation = 0.95) between CSF and tissue. Finally, H3K27M mutations in CSF exhibited high diagnostic efficiency for DMG, H3K27-altered (Sensitivity = 85.7%, Specificity = 100.0%, AUC = 0.929). Notably, H3K27M was detectable in CSF from patients with recurrent tumors, making it easily applicable for postoperative monitoring. In conclusion, the molecular profile from ctDNA released into CSF of malignant tumors was more frequently detected compared to relatively benign ones. Sequencing of ctDNA in CSF exhibited high efficiency for the differential diagnosis of DMG, H3K27-altered.

Determination of 4-tert-octylphenol in surface water samples of Jinan in China by solid phase extraction coupled with GC-MS.

Octylphenols, considered as xenoestrogens, mainly exist as 4-tert-octylphenol (OP) in aquatic environments. The high stability and accumulation of OP in aquatic systems have caused endocrine disruption. The OP in surface water in Jinan, China was analyzed by gas chromatography-mass spectrometry (GC-MS) coupled with solid phase extraction (SPE). Water samples were extracted by SPE on a cartridge system containing C-18 as sorbent. To increase sensitivity and selectivity, OP was derivatized to 4-tert-octyl-phenoxy silane. With the use of phenanthrene-d10 as internal standard, the detection limit based on signal-to-noise ratio (S/N = 3) was 0.06 ng/mL. The average recovery was from 84.67% to 109.7%. The precision of the method given as the relative standard deviations (RSD) was within the range 6.24%-12.96%. In the target water samples, the concentrations of OP were as follows: 15.88-71.24 ng/L for Jinxiuchuan Reservoir, 3.850-26.68 ng/L for the city moat, 6.930-41.56 ng/L for Daming Lake, 66.03-474.2 ng/L for Xiaoqing River, 14.66-17.72 ng/L for the Yellow River, and 10.60-26.43 ng/L for Queshan Reservoir. The Xiaoqing River was seriously polluted due to the discharge of wastewater from Jinan. Jinxiuchuan Reservoir had a higher concentration of OP compared with the Yellow River and Queshan Reservoir, which is ascribed to the surrounding human activities. These data are reported for the first time, providing strong support for the control of OP pollution in Jinan.

A multiregional survey of nickel in outdoor air particulate matter in China: Implication for human exposure.

Nickel is a widespread environmental contaminant, and it is toxic to humans in certain forms at high doses. Despite this, nationwide data on nickel in outdoor air particulate matter and human exposure to nickel through inhalation in China are limited. In the present study, 662 outdoor air samples from seven representative provinces such as Shanghai, Hubei, Hunan, Hebei, Guangdong, Yunnan, and Shanxi were collected between March 2013 and February 2014 and analyzed by inductively coupled plasma mass spectrometry. The concentrations of nickel in the air were in the range of 2.1-80.9 ng/m3 (geometric mean: 14.4 ng/m3). In most areas, the concentrations of nickel were higher in winter and spring than those measured in summer and autumn. The daily intake (median) of nickel through inhalation of air particulate matter was estimated. Although the nickel concentrations in some air samples were high, inhalation of the air particulate matter accounted for a minor part of the total nickel intake; however, the adverse effects of human exposure to nickel through inhalation and its potential sources require more attention, particularly in Shanghai. This is a multiregional survey of nickel in outdoor air particulate matter in China.

Relationship between maternal exposure to bisphenol S and pregnancy duration.

Bisphenol S (BPS) has been progressively used due to the potential safety problems of bisphenol A (BPA). Thus Human studies are needed to investigate the developmental effects of BPS. In this study, the impact of maternal BPS exposure on birth outcomes was evaluated with linear and logistic regression models. BPS was analyzed in spot urine samples collected from 985 pregnant women at admission to labor. It was found in 93.7% of the urine samples with the specific gravity adjusted geometric mean concentration of 0.17 µg/L. One ln-unit increase in urinary BPS was associated with a 0.72-day increase in pregnancy duration (95% CI: 0.34, 1.09). When stratified by fetal sex, each ln-unit increase in maternal urinary BPS was significantly correlated with increased gestational age [adjusted ß = 1.02, 95% confidence intervals (CI): 0.47, 1.57] and increased odds of late term birth [adjusted odds ratio = 1.29, 95% CI: 1.00, 1.67] for girls, but not significantly for boys. Including maternal urinary BPA and BPS in one model did not change the results. Associations of BPS with birth weight or length were not observed. This is the first report about BPS exposure for pregnant women from China. Higher maternal urinary BPS concentrations were associated with increased gestational age, suggesting maternal BPS exposure may interfere with pregnancy duration. The findings require replication but reveal the probable risks posed by the developmental BPS exposure.

Effect of ginkgolide B on the platelet-activating factor induced changes of chemotaxis and cytoskeleton of macrophages.

AIM: To study the inhibitory effect of ginkgolide B (BN52021) on the PAF induced changes of chemotaxis of murine peritoneal macrophages and the related polymerization of F-actin. METHODS: Chemotaxis assays were performed using a modified 48-well Boyden chamber. Actin polymerization of murine peritoneal macrophages was analyzed by flow cytometry using a specific fluorescent stain. RESULTS: Peritoneal macrophages significantly migrated toward platelet-activating factor (PAF) through a micropore filter; however, in the presence of PAF receptor antagonist BN52021 (0.01 nmol x L(-1) -0.1 micromol x L(-1)), the migration was significantly inhibited. Moreover, BN52021 inhibited the actin polymerization of murine peritoneal macrophages induced by PAF in the presence of Ca2+, but not in Ca2+ -free medium. CONCLUSION: The results suggested that preventing polymerization of F-actin may be a pathway by BN52021 to inhibit the chemotaxis of macrophages, and this effect seems to be Ca2+ dependent. The data further indicated that inhibition of PAF induced macrophage chemotaxis is an important mechanism underlying the anti-inflammatory action of BN52021.

Binding mechanism of CDK5 with roscovitine derivatives based on molecular dynamics simulations and MM/PBSA methods.

Roscovitine derivatives are potent inhibitors of cyclin-dependent kinase 5 (CDK5), but they exhibit different activities, which has not been understood clearly up to now. On the other hand, the task of drug design is difficult because of the fuzzy binding mechanism. In this context, the methods of molecular docking, molecular dynamics (MD) simulation, and binding free energy analysis are applied to investigate and reveal the detailed binding mechanism of four roscovitine derivatives with CDK5. The electrostatic and van der Waals interactions of the four inhibitors with CDK5 are analyzed and discussed. The calculated binding free energies in terms of MM-PBSA method are consistent with experimental ranking of inhibitor effectiveness for the four inhibitors. The hydrogen bonds of the inhibitors with Cys83 and Lys33 can stabilize the inhibitors in binding sites. The van der Waals interactions, especially the pivotal contacts with Ile10 and Leu133 have larger contributions to the binding free energy and play critical roles in distinguishing the variant bioactivity of four inhibitors. In terms of binding mechanism of the four inhibitors with CDK5 and energy contribution of fragments of each inhibitor, two new CDK5 inhibitors are designed and have stronger inhibitory potency.

[Inhibitory effect of ginkgolide B on angiogenesis in chronic inflammation].

AIM: To investigate the inhibitory effect of ginkgolide B on angiogenesis in chronic inflammation and the possible mechanisms. METHODS: The murine chronic granulomatous air pouch model was used to observe the anti-angiogenesis effect of ginkgolide B. The vascular index was determined by colorimetry of carminic acid, and angiogenesis was observed by histology method. The interleukin-1beta (IL-1beta) levels in mice serum and in supernatants of U937 cell culture stimulated by phorbol 12-myristate 13-acetate (PMA) were detected by radioimmunoassay (RIA). The tumor necrosis factor-alpha (TNF-alpha) levels in mice serum and in supernatant of U937 cell culture were measured by cytotoxicity bioassay. The mRNA expression of IL-1beta and TNF-alpha of U937 cell culture was investigated by RT-PCR. RESULTS: Oral administration of ginkgolide B 25 and 100 mg x kg(-1) was shown to significantly inhibit the vascular index of murine chronic granulomatous air pouch model with the inhibitory rate of 22.52% and 25.29%, respectively. This result was supported by histological observation. Concomitantly, the IL-1beta levels in mice serums were also significantly decreased with the inhibitory rate of 50.61% and 58.66%; so were the TNF-alpha levels with the inhibitory rate of 28.91% and 52.41%. Ginkgolide B at concentration of 1 x 10(-5) to 1 x 10(-8) mol x L(-1) could also reduce both the IL-1beta and TNF-alpha contents in the supernatants of U937 cell culture stimulated by PMA, but the scopes of changes were much different. For IL-1beta the IC50 was 1.93 x 10(-8) mol x L(-1), while ginkgolide B at concentration of 1 x 10(-5) mol x L(-1) only decreased the release of TNF-alpha by 25.99%. Furthermore, ginkgolide B at concentrations of 1 x 10(-5) to 1 x 10(-7) mol x L(-1) was shown to significantly inhibit TNF-alpha mRNA expression of U937 cells; and at concentrations of 1 x 10(-5) and 1 x 10(-6) mol x L(-1) could inhibit IL-1beta mRNA expression. CONCLUSION: Ginkgolide B was shown to significantly inhibit angiogenesis of the murine chronic granulomatous air pouch model, reduce the IL-1beta and TNF-alpha levels in mice serums, and significantly inhibit IL-1beta and TNF-alpha mRNA expression and protein secretion in supernatants of U937 cell culture. It was suggested that reduction of proangiogenic cytokines IL-1beta and TNF-alpha secretion may contribute to the anti-angiogenesis effect of ginkgolide B in the murine chronic granulomatous air pouch model.