Antibacterial activity of Sargassum polycystum C. Agardh and Padina australis Hauck (Phaeophyceae)

Seaweeds are used in pharmaceutical and biochemical applications as they possess interesting biological activities that contribute to the discovery of natural therapeutic agents. In this study, the antibacterial activity of n-hexane, dichloromethane and methanolic extracts of brown seaweeds (Phaeophyceae), Sargassum polycystum C. Agardh and Padina australis Hauck, was examined using the disc diffusion and broth microdilution methods. The bioactivity of the seaweed extracts was expressed as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The antibacterial activity against Gram-negative bacteria (beta-lactamase positive and negative Escherichia coli, Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus) was discussed. Gram-positive bacteria especially B. cereus was more susceptible to the seaweed extracts (MIC = 0.130 to 0.065 mg/ml). Generally, S. polycystum extracts exhibited higher bacteriostatic activity (lower MICs) against all the tested bacterial strains when compared with P. australis. However, P. australis extracts showed a narrow spectrum of bactericidal activity against B. cereus. n-Hexane extracts of S. polycystum exhibited promising bacteriostatic agents against B. cereus (MIC = 0.065 mg/ml) with MIC value lower than the standard MIC of potential antimicrobial drug (0.100 mg/ml). Since only crude seaweed extracts were tested in this study, further purification and isolation of bioactive compounds from the extracts are essential in future studies in order to optimize their antibacterial activity.Key words: Phaeophyceae, disc diffusion test, minimum bactericidal concentration (MBC), minimum inhibition concentration (MIC)

A role of ygfZ in the Escherichia coli response to plumbagin challenge

Plumbagin is found in many herbal plants and inhibits the growth of various bacteria. Escherichia coli strains are relatively resistant to this drug. The mechanism of resistance is not clear. Previous findings showed that plumbagin treatment triggered up-regulation of many genes in E. coli including ahpC, mdaB, nfnB, nfo, sodA, yggX and ygfZ. By analyzing minimal inhibition concentration and inhibition zones of plumbagin in various gene-disruption mutants, ygfZ and sodA were found critical for the bacteria to resist plumbagin toxicity. We also found that the roles of YgfZ and SodA in detoxifying plumbagin are independent of each other. This is because of the fact that ectopically expressed SodA reduced the superoxide stress but not restore the resistance of bacteria when encountering plumbagin at the absence of ygfZ. On the other hand, an ectopically expressed YgfZ was unable to complement and failed to rescue the plumbagin resistance when sodA was perturbed. Furthermore, mutagenesis analysis showed that residue Cys228 within YgfZ fingerprint region was critical for the resistance of E. coli to plumbagin. By solvent extraction and HPLC analysis to follow the fate of the chemical, it was found that plumbagin vanished apparently from the culture of YgfZ-expressing E. coli. A less toxic form, methylated plumbagin, which may represent one of the YgfZ-dependent metabolites, was found in the culture supernatant of the wild type E. coli but not in the ΔygfZ mutant. Our results showed that the presence of ygfZ is not only critical for the E coli resistance to plumbagin but also facilitates the plumbagin degradation

An Attention-Guided Deep Regression Model for Landmark Detection in Cephalograms

Cephalometric tracing method is usually used in orthodontic diagnosis and treatment planning. In this paper, we propose a deep learning based framework to automatically detect anatomical landmarks in cephalometric X-ray images. We train the deep encoder-decoder for landmark detection, and combine global landmark configuration with local high-resolution feature responses. The proposed frame-work is based on 2-stage u-net, regressing the multi-channel heatmaps for land-mark detection. In this framework, we embed attention mechanism with global stage heatmaps, guiding the local stage inferring, to regress the local heatmap patches in a high resolution. Besides, the Expansive Exploration strategy improves robustness while inferring, expanding the searching scope without increasing model complexity. We have evaluated our framework in the most widely-used public dataset of landmark detection in cephalometric X-ray images. With less computation and manually tuning, our framework achieves state-of-the-art results

Molecular Characterization of Tick Salivary Gland Glutaminyl Cyclase

Glutaminyl cyclase (QC) catalyzes the cyclization of N-terminal glutamine residues into pyroglutamate. This post-translational modification extends the half-life of peptides and, in some cases, is essential in binding to their cognate receptor. Due to its potential role in the post-translational modification of tick neuropeptides, we report the molecular, biochemical and physiological characterization of salivary gland QC during the prolonged blood feeding of the black-legged tick (Ixodes scapularis) and the gulf-coast tick (Amblyomma maculatum). QC sequences from I. scapularis and A. maculatum showed a high degree of amino acid identity to each other and other arthropods and residues critical for zinc binding/catalysis (D159, E202, and H330) or intermediate stabilization (E201, W207, D248, D305, F325, and W329) are conserved. Analysis of QC transcriptional gene expression kinetics depicts an upregulation during the bloodmeal of adult female ticks prior to fast-feeding phases in both I. scapularis and A. maculatum suggesting a functional link with bloodmeal uptake. QC enzymatic activity was detected in saliva and extracts of tick salivary glands and midguts. Recombinant QC was shown to be catalytically active. Furthermore, knockdown of QC transcript by RNA interference resulted in lower enzymatic activity, and small, unviable egg masses in both studied tick species as well as lower engorged tick weights for I. scapularis. These results suggest that the post-translational modification of neurotransmitters and other bioactive peptides by QC is critical to oviposition and potentially other physiological processes. Moreover, these data suggest that tick-specific QC-modified neurotransmitters/hormones or other relevant parts of this system could potentially be used as novel physiological targets for tick control

Evaluations of Port Performances from a Seaborne Cargo Supply Chain Perspective

Previous research on port efficiency focuses primarily on the provider’s perspective and assumes that maximizing the output is always desirable. This paper recognizes that maximizing the final output does not necessarily guarantee an efficient system and the notion of port efficiency and service effectiveness needs to be considered from the perspectives of both the provider and the consumer of the port service. The paper proposes a network-DEA model to evaluate the performances of 30 seaports worldwide. The concurrent consideration of efficiency scores from the network-DEA model and the traditional DEA-CCR model will offer valuable insights to port operators on how to improve port performances as part of a seaborne cargo supply chain

Pulmonary IL- 33 orchestrates innate immune cells to mediate respiratory syncytial virus- evoked airway hyperreactivity and eosinophilia

BackgroundRespiratory syncytial virus (RSV) infection is epidemiologically linked to asthma. During RSV infection, IL- 33 is elevated and promotes immune cell activation, leading to the development of asthma. However, which immune cells are responsible for triggering airway hyperreactivity (AHR), inflammation and eosinophilia remained to be clarified. We aimed to elucidate the individual roles of IL- 33- activated innate immune cells, including ILC2s and ST2+ myeloid cells, in RSV infection- triggered pathophysiology.MethodsThe role of IL- 33/ILC2 axis in RSV- induced AHR inflammation and eosinophilia were evaluated in the IL- 33- deficient and YetCre- 13 Rosa- DTA mice. Myeloid- specific, IL- 33- deficient or ST2- deficient mice were employed to examine the role of IL- 33 and ST2 signaling in myeloid cells.ResultsWe found that IL- 33- activated ILC2s were crucial for the development of AHR and airway inflammation, during RSV infection. ILC2- derived IL- 13 was sufficient for RSV- driven AHR, since reconstitution of wild- type ILC2 rescued RSV- driven AHR in IL- 13- deficient mice. Meanwhile, myeloid cell- derived IL- 33 was required for airway inflammation, ST2+ myeloid cells contributed to exacerbation of airway inflammation, suggesting the importance of IL- 33 signaling in these cells. Local and peripheral eosinophilia is linked to both ILC2 and myeloid IL- 33 signaling.ConclusionsThis study highlights the importance of IL- 33- activated ILC2s in mediating RSV- triggered AHR and eosinophilia. In addition, IL- 33 signaling in myeloid cells is crucial for airway inflammation.Respiratory syncytial virus induces ILC2 to produce IL- 5 and IL- 13 through IL- 33, which is crucial for the development of airway hyperreactivity and airway inflammation. Myeloid cell- derived IL- 33 and suppression of tumorigenicity 2- positive myeloid cells contribute to cytokine production and cellular inflammation in airway. Both ILC2 and myeloid cell IL- 33 signaling contribute to local and peripheral eosinophilia.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154896/1/all14091.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154896/2/all14091-sup-0001-Supinfo.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154896/3/all14091_am.pd

Underexpression of Deleted in liver cancer 2 (DLC2) is associated with overexpression of RhoA and poor prognosis in hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>DLC2, a unique RhoGAP, has been recently identified as a tumor suppressor gene in hepatocellular carcinoma (HCC). However, the expression of DLC2 protein, and its relationship with RhoA in clinical hepatocellular carcinoma have not been studied. The aim of this study was to investigate the DLC2 protein expression and its correlation with expression of RhoA, as well as to evaluate the prognostic value of DLC2 for HCC patients.</p> <p>Methods</p> <p>Western blot and immunohistochemical staining were employed to detect DLC2 protein expression in 128 HCC specimens. The correlation between DLC2 protein expression and clinicopathologic outcome, and prognostic value of DLC2 for HCC patients were analyzed.</p> <p>Results</p> <p>HCC tissues revealed significantly lower level of DLC2 protein than pericarcinomatous liver tissues (PCLT). There was significant correlation between underexpression of DLC2 protein and cell differentiation. Meanwhile, underexpression of DLC2 protein was correlated with overexression of RhoA. Furthermore, HCC Patients with DLC2-negative expression showed a significantly poorer prognosis than those with DLC2-positve expression.</p> <p>Conclusion</p> <p>Our data strongly suggested that decreased DLC2 expression in HCC correlates with cell differentiation of HCC and overexpression of RhoA, underexpression of DLC2 is associated with poor prognosis in HCC patients.</p

Comparison of the Electronic Structures and Energetics of Ferroelectric LiNbO3 and LiTaO3

This paper explains the origin of the ferroelectric instability in LiNbO3 and LiTaO3 and compares the electronic structures and energetics of the two materials.Comment: 31 pages, 11 Postscript figure