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1.
Front Immunol ; 13: 879775, 2022.
Article in English | MEDLINE | ID: mdl-36090984

ABSTRACT

Arabinogalactan (AG) participates in forming the cell wall core of mycobacteria, a structure known as the mAGP complex. Few studies have reported the virulence of inartificial AG or its interaction with the host immune system. Using clustered regularly interspaced short palindromic repeats interference gene editing technology, conditional Mycobacterium marinum mutants were constructed with a low expression of embA or glfT2 (EmbA_KD or GlfT2_KD), which are separately involved in the biosynthesis of AG arabinose and galactose domains. High-performance gel permeation chromatography and high-performance liquid chromatography assays confirmed that the EmbA_KD strain showed a remarkable decrease in AG content with fragmentary arabinose chains, and the GlfT2_KD strain displayed less reduction in content with cut-down galactose chains. Based on transmission and scanning electron microscopy observations, the cell walls of the two mutants were found to be dramatically thickened, and the boundaries of different layers were more distinct. Phenotypes including the over-secretion of extracellular substances and enhanced spreading motility with a concomitant decreased resistance to ethambutol appeared in the EmbA_KD strain. The EmbA_KD and GlfT2_KD strains displayed limited intracellular proliferation after infecting murine J774A.1 macrophages. The disease progression infected with the EmbA_KD or GlfT2_KD strain significantly slowed down in zebrafish/murine tail infection models as well. Through transcriptome profiling, macrophages infected by EmbA_KD/GlfT2_KD strains showed enhanced oxidative metabolism. The cell survival measured using the CCK8 assay of macrophages exposed to the EmbA_KD strain was upregulated and consistent with the pathway enrichment analysis of differentially expressed genes in terms of cell cycle/apoptosis. The overexpression of C/EBPß and the increasing secretion of proinflammatory cytokines were validated in the macrophages infected by the EmbA_KD mutant. In conclusion, the AG of Mycobacterium appears to restrain the host innate immune responses to enhance intracellular proliferation by interfering with oxidative metabolism and causing macrophage death. The arabinose chains of AG influence the Mycobacterium virulence and pathogenicity to a greater extent.


Subject(s)
Mycobacterium marinum , Animals , Arabinose , Galactans , Galactose , Immunity, Innate , Mice , Virulence , Zebrafish
2.
Fish Shellfish Immunol ; 127: 148-154, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35714896

ABSTRACT

Infectious spleen and kidney necrosis virus (ISKNV) is the type species of the Megalocytivirus genus that infects a number of marine and freshwater fishes, causing huge economic losses in aquaculture. The ISKNV infection leads to increase of reducing power in cells. As the antibiotic neomycin can promote the production of reactive oxygen species (ROS) in animal cells, in the current study, the potential therapeutic effect of neomycin on ISKNV infection was explored. We showed that neomycin could decrease the reducing power in cultured MFF-1 cells and inhibit ISKNV infection by antagonizing the shift of the cellular redox balance toward reduction. In vivo experiments further demonstrated that neomycin treatment significantly suppresses ISKNV infection in mandarin fish. Expression of the major capsid protein (MCP) and the proportion of infected cells in tissues were down-regulated after neomycin treatment. Furthermore, neomycin showed complex effects on expression of a set of antiviral related genes of the host. Taking together, the current study suggested that the viral-induced redox imbalance in the infected cells could be used as a target for suppressing ISKNV infection. Neomycin can be potentially utilized for therapeutic treatment of Megalocytivirus diseases by antagonizing intracellular redox changes.


Subject(s)
DNA Virus Infections , Fish Diseases , Iridoviridae , Animals , DNA Virus Infections/veterinary , Fishes , Glutathione , Iridoviridae/genetics , Neomycin/pharmacology
3.
Microbiol Spectr ; 10(2): e0044321, 2022 04 27.
Article in English | MEDLINE | ID: mdl-35266819

ABSTRACT

Granulomas are the pathological hallmark of tuberculosis (TB). In individuals with latent TB infection, Mycobacterium tuberculosis cells reside within granulomas in a nonreplicating dormant state, and a portion of them will develop active TB. Little is known on the bacterial mechanisms/factors involved in this process. In this study, we found that WhiB4, an oxygen sensor and a transcription factor, plays a critical role in disease progression and reactivation of Mycobacterium marinum (M. marinum) infection in zebrafish. We show that the whiB4::Tn mutant of M. marinum caused persistent infection in adult zebrafish, which is characterized by the lower but stable bacterial loads, constant number of nonnecrotized granulomas in fewer organs, and reduced inflammation compared to those of zebrafish infected with the wild-type bacteria or the complemented strain. The mutant bacteria in zebrafish were also less responsive to antibiotic treatments. Moreover, the whiB4::Tn mutant was defective in resuscitation from hypoxia-induced dormancy and the DosR regulon was dysregulated in the mutant. Taken together, our results suggest that WhiB4 is a major driver of reactivation from persistent infection. IMPORTANCE About one-quarter of the world's population has latent TB infection, and 5 to 10% of those individuals will fall ill with TB. Our finding suggests that WhiB4 is an attractive target for the development of novel therapeutics, which may help to prevent the reactivation of latent infection, thereby reducing the incidences of active TB.


Subject(s)
Latent Tuberculosis , Mycobacterium marinum , Mycobacterium tuberculosis , Tuberculosis , Animals , Granuloma/microbiology , Mycobacterium Infections, Nontuberculous , Mycobacterium marinum/genetics , Persistent Infection , Tuberculosis/microbiology , Zebrafish/microbiology
4.
Front Pharmacol ; 12: 774884, 2021.
Article in English | MEDLINE | ID: mdl-34916949

ABSTRACT

Background: Intrahepatic cholestasis of pregnancy (ICP) seriously threatens the health of pregnant women and newborns. A various number of Chinese prescriptions and patent medicines combined with ursodeoxycholic acid (UDCA) are used for treating ICP in China. However, there are still many doubts in choosing the suitable therapeutic drugs for the treatment of ICP in clinical practice. Methods: Several electronic databases, including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biology Medicine disc (CBM), Wanfang, and VIP, were comprehensively searched from the database inception to February 22, 2021. Randomized controlled trials (RCTs) reporting the use of UDCA only, Chinese prescriptions plus UDCA, and patent medicine plus UDCA for the treatment of ICP were collected according to their inclusion and exclusion criteria. Cochrane Reviewers' Handbook version 5.2 was applied for the risk assessment of the included trials. STATA 16.0 software was used for network meta-analysis (NMA). The pruritus score and the serum levels of total bile acid (TBA), alanine aminotransferase (ALT), and aspartate transaminase (AST) in ICP patients served as the primary outcomes. Moreover, this study had been registered in PROSPERO (https://www.crd.york.ac.uk/PROSPERO/#joinuppage), and the registration number is CRD42020188831. Results: Thirty-eight RCTs comprising 3,841 patients meeting the inclusion criteria were included in the network meta-analysis. The NMA results showed that compared with UDCA used alone, Yinchenhao decoction (seven different Chinese prescriptions or patent medicines) plus UDCA dramatically alleviated the primary outcomes of ICP, including the pruritus score, as well as the serum levels of TBA, ALT, and AST. The NMA results showed that the optimal drug ratio for the treatment of ICP was different from the dosage ratio of traditional Yinchenhao decoction. Significantly, the intervention plan f (IP-f) group [the similar prescription of Yinchenhao decoction 2 (Artemisia capillaris Thunb >15 g, Gardenia >9 g, and Rhubarb <5 g) + UDCA] was the best therapeutics among the eight therapies. Conclusion: Overall, the combined use of Chinese prescriptions or patent medicine with UDCA was generally better than UDCA used alone. The dose of IP-f might be a beneficial therapeutic method for the clinical medication of ICP. Clinical Trail Registration: https://www.crd.york.ac.uk/, identifier CRD42020188831.

5.
Zhongguo Yi Liao Qi Xie Za Zhi ; 39(2): 146-8, 2015 Mar.
Article in Chinese | MEDLINE | ID: mdl-26204750

ABSTRACT

In this paper, we analyse the general information of medical equipment clinical trials by clinical trial process management experience to elaborate the characteristics of the medical equipment clinical trials and the existent problems in our hospital in 10 years. We propose corresponding countermeasures to ensure the quality of medical tests, and improve the management of medical equipment clinical trials in hospital.


Subject(s)
Clinical Trials as Topic , Equipment and Supplies, Hospital , Humans
6.
Dalton Trans ; 40(28): 7357-64, 2011 Jul 28.
Article in English | MEDLINE | ID: mdl-21681291

ABSTRACT

The structural, optical, and electronic properties of four rare-earth bismuth tungstate compounds, LnBiW(2)O(9) (Ln = Ce, Sm, Eu, Er), have been investigated by means of single-crystal X-ray diffraction, elemental analyses, and spectral measurements. For some of the compounds, the calculations of energy band structures and density of states have also been made by the density functional theory. The structure of CeBiW(2)O(9) features a three-dimensional (BiW(2)O(9))(3-) anionic framework with interesting channels where Ce atoms are located. The framework is constructed by one-dimensional BiO(9) polyhedra chains and one-dimensional zigzag W(2)O(9) chains via edge- and face-sharing. LnBiW(2)O(9) (Ln = Sm, Eu, Er) are isostructural and their structures feature a three-dimensional network based on alternating (BiO(2))(-) layers and (Ln(2)W(2)O(12))(6-) layers connected by corner-linked chains of WO(6) octahedra. Results of spectral measurements indicate that EuBiW(2)O(9) exhibit the characteristic yellow-red light emission under excitation at 395 nm, and it will be a red phosphor in designing white light-emitting diode device. The calculated results of band structures by using the density functional theory (DFT) show that the solid-state compound CeBiW(2)O(9) and SmBiW(2)O(9) are indirect band gap materials.

7.
Dalton Trans ; 40(17): 4474-9, 2011 May 07.
Article in English | MEDLINE | ID: mdl-21437298

ABSTRACT

Two new quaternary thioborates, PbSbBS(4) and PbBiBS(4), have been synthesized from solid-state reaction methods at temperatures from 1073 to 1123 K in evacuated sealed quartz tubes. The crystal structures have been determined by means of single crystal X-ray diffraction and they both crystallize in the P2(1)/m space group of the monoclinic system with a = 5.9532(18) Å, b = 6.2031(13) Å, c = 9.250(3) Å, ß = 108.200(16)°, Z = 2 for PbSbBS(4) and a = 5.971(10) Å, b = 6.273(9) Å, c = 9.132(15) Å, ß = 107.75(2)°, Z = 2 for PbBiBS(4), respectively. The two compounds are isostructural and both constructed with the infinite one-dimensional [MBS(4)](2-) (M = Sb or Bi) chains as building blocks, which are composed of [BS(3)](3-) trigonal plane units with [MS(3)](3-) (M = Sb or Bi) trigonal pyramids connected alternatively through corner-sharing along the crystallographic b axis. Two adjacent [MBS(4)](2-) chains are further bridged by the intermediate Pb(2+) cations, forming a novel S-shaped Pb-[MBS(4)] dimeric chain structure. In addition, first-principles electronic structure calculations based on the density functional theory (DFT) were performed on compound PbSbBS(4), indicating that the compound belongs to direct semiconductor with a band gap of 1.803 eV, which is in good agreement with the experimental value estimated from the UV-Vis diffuse reflectance spectroscopy.

8.
Inorg Chem ; 50(6): 2378-84, 2011 Mar 21.
Article in English | MEDLINE | ID: mdl-21332210

ABSTRACT

Two new quaternary sulfides, Ba(2)SbFeS(5) and Ba(2)BiFeS(5), were synthesized by using a conventional high-temperature solid-state reaction method in closed silica tubes at 1123 K. The two compounds both crystallize in the orthorhombic space group Pnma with a = 12.128(6) Å, b = 8.852(4) Å, c = 8.917(4) Å, and Z = 4 for Ba(2)SbFeS(5) and a = 12.121(5) Å, b = 8.913(4) Å, c = 8.837(4) Å, and Z = 4 for Ba(2)BiFeS(5). The crystal structure unit can be viewed as an infinite one-dimensional edge-shared MS(5) (M = Sb, Bi) tetragonal-pyramid chain with FeS(4) tetrahedra alternately arranged on two sides of the MS(5) polyhedral chain via edge-sharing (so the chain can also be written as (1)(∞)[MFeS(5)](4-)). Interestingly, the compounds have the structural type of a Ba(3)FeS(5) high-pressure phase considering one Ba(2+) is replaced by one Sb(3+)/Bi(3+), with Fe(4+) reduced to Fe(3+) for in order to maintain the electroneutrality of the system. As a result, the isolated iron ions in Ba(3)FeS(5) are bridged by intermediate MS polyhedra in Ba(2)MFeS(5) (M = Sb, Bi) compounds and form the (1)(∞)[MFeS(5)](4-) chain structure. This atom substitution of Ba(2+) by one Sb(3+)/Bi(3+) leads to a magnetic transition from paramagnetic Ba(3)FeS(5) to antiferromagnetic Ba(2)MFeS(5), resulting from an electron-exchange interaction of the iron ions between inter- or intrachains. Magnetic property measurements indicate that the two compounds are both antiferromagnetic materials with Néel temperatures of 13 and 35 K for Ba(2)SbFeS(5) and Ba(2)BiFeS(5), respectively. First-principles electronic structure calculations based on density functional theory show that the two compounds are both indirect-band semiconductors with band gaps of 0.93 and 1.22 eV for Ba(2)SbFeS(5) and Ba(2)BiFeS(5), respectively.

9.
Inorg Chem ; 49(14): 6609-15, 2010 Jul 19.
Article in English | MEDLINE | ID: mdl-20557102

ABSTRACT

Two new quaternary thioborate compounds with strongly one-dimensional growth, BaSb(BS(3))S and BaBi(BS(3))S, have been synthesized using the conventional solid state reaction method in closed tubes at 1100 K. The single crystal X-ray diffraction analysis has shown that compound BaSb(BS(3))S crystallizes in space group Pnma of the orthorhombic system with unit cell parameters of a = 9.6898(15) A, b = 6.2293(13) A, c = 11.670(2) A, V = 704.4(2) A(3), and Z = 4, while compound BaBi(BS(3))S crystallizes in space group C2/m with unit cell parameters of a = 14.9890(17) A, b = 6.2457(6) A, c = 7.5591(9) A, beta = 101.604(5) degrees , V = 693.19(13) A(3), and Z = 4. The two compounds both crystallize in the structure of infinite one-dimensional chains with [BS(3)](3-) trigonal plane coordination alternately bridged by [MS(3)](3-) (M = Sb, Bi) trigonal pyramids through sharing two sulfur atoms along the crystallographic b axis. First-principles electronic structure calculations performed with the density functional theory (DFT) method show that the calculated band gaps of BaSb(BS(3))S and BaBi(BS(3))S are 2.29 and 2.16 eV, respectively, which are in good agreement with the experimental values estimated from UV-vis absorption spectra using the Kubelka-Munk equation, and the observed absorption peak is assigned as charge transfers from S-3p states to Sb-5p (Bi6p) states.

10.
Inorg Chem ; 49(5): 2550-6, 2010 Mar 01.
Article in English | MEDLINE | ID: mdl-20112999

ABSTRACT

Explorations of the A(I)-M(III)-B(III)-P(V)-O quinary system under solid-state reactions led to an anhydrous cesium-chromium borophosphate-phosphate and an anhydrous cesium-iron borophosphate, namely, Cs(2)Cr(3)(BP(4)O(14))(P(4)O(13)) (1) and CsFe(BP(3)O(11)) (2). They both feature complicated three-dimensional (3D) frameworks and represent the first examples of borophosphate frameworks with a P-O-P connection. Compound 1 contains a novel anionic borophosphate partial structure [B(P(2)O(7))(2)](5-) with B:P = 1:4 besides an isolated [P(4)O(13)](6-) anion. Its 3D structure is composed of a layer of [CrB(P(2)O(7))(2)](n)(2n-) and a neutral layer of [Cr(2)(P(4)O(13))](n) interconnected with the linking of P-O-Cr, and the Cs ions are located at the space. Compound 2 contains another novel borophosphate anionic unit of [B(PO(4))(P(2)O(7))](4-) with B:P = 1:3, which further bridges the Fe cations to constitute the whole structure. Both compounds are of high thermal stable and transparent in the range of 0.75-7.1 microm. Magnetic measurements indicate that there exist antiferromagnetic interactions in both compounds.

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