Retrospective analysis of molecular characteristics, risk factors, and outcomes in carbapenem-resistant Klebsiella pneumoniae bloodstream infections.

Background: Klebsiella pneumoniae (KP) is the second most prevalent Gram-negative bacterium causing bloodstream infections (BSIs). In recent years, the management of BSIs caused by KP has become increasingly complex due to the emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP). Although numerous studies have explored the risk factors for the development of CRKP-BSIs, the mortality of patients with KP-BSIs, and the molecular epidemiological characteristics of CRKP, the variability in data across different populations, countries, and hospitals has led to inconsistent conclusions.

Infection in Nephrotic Syndrome Patients: Three Case Studies and A Systematic Literature Review.

Objective: The multicenter literature review and case studies of 3 patients were undertaken to provide an updated understanding of nocardiosis, an opportunistic bacterial infection affecting immunosuppressed nephrotic syndrome (NS) patients receiving long-term glucocorticoid and immunosuppressant treatment. The results provided clinical and microbiological data to assist physicians in managing nocardiosis patients.

Methods: Three cases between 2017 and 2018 from a single center were reported.

Theoretical Insights into Imidazolidine Oxidation of Imidacloprid by Cytochrome P450 3A4.

The metabolic mechanisms for imidazolidine oxidation of imidacloprid (IMI) by cytochrome P450 3A4 (CYP3A4) have been investigated using quantum mechanical/molecular mechanical (QM/MM) calculations. The binding mode of CYP3A4 with IMI is examined by molecular docking in collaboration with molecular dynamics (MD) simulations. The results show that there are six amino acid residues, involving Arg192, Phe195, Ile349, Ala285, Phe284 and Phe88, closely distributed around the IMI.

[Chemical Constituents from Fruit Dregs of Rhus chinensis( Ⅱ)].

Objective: To investigate the constituents from the fruit dregs of Rhus chinensis.

Methods: The constituents were isolated and purified by chromatography on silica gel,Sephadex LH-20,RP-C18 and Pre-TLC and recrystalization. The structures were identified on the basis of the chemical evidence,spectroscopic data.

[Chemical Constituents From Rhus chinensis Fruit Dregs].

Objective: To isolate and elucidate the constituents from the fruit dregs of Rhus chinensis.

Methods: The constituents were isolated and purified by chromatography on silica gel,Sephadex LH-20, RP-C18 gel and recrystallization. The structures were elucidated on the basis of the chemical evidence and spectroscopic data.

[Chemical constituents of Acori Calami Rhizoma from Hunan Province].

Objective: To study the chemical components from the ethanol extract of Acori Calami Rhizoma from Hunan Province.

Methods: Components were isolated and purified through various chromatographic methods and recrystallization, and identified by spectroscopic data.

Results: Ten compounds were isolated and identified as follows: heptadecanoic acid(1), monopentadecanoin(2), syringic acid(3), aurantiamide acetate(4), monononadecanoin(5),tatarine A(6),tatanan C(7),cerevisterol(8),2 ,6-dioxopiperidin-3-yl acetate(9) and palmatine(10).

[Chemical constituents from Pholidota cantonensis].

Objective: To isolate and elucidate the constituents from whole plant of Pholidota cantonensis.

Methods: The constituents were isolated and purified by silica gel, Sephadex LH-20 and MCI gel chromatography and recrystallization. The structures were elucida- ted on the basis of the chemical evidence and spectroscopic data.

Mechanism for the reaction of 2-naphthol with N-methyl-N-phenyl-hydrazine suggested by the density functional theory investigations.

For the first time the computed mechanisms for the novel reaction of 2-naphthol with N-methyl-N-phenylhydrazine, leading to 1-amino-2-naphthol (Tang et al., J Am Chem Soc 2008, 130, 5840), have been investigated using the density functional theory. Four distinct possible pathways were evaluated: two amination mechanisms with the attack of NH(2) group respectively at the α-position C1 and β-position C3 atoms of 2-naphthol (pathways 1 and 2) as well as two rearrangement processes with displacement of the phenolic hydroxyl group followed by the benzidine-like rearrangement at the α-position C1 and β-position C3 atoms of 2-naphthol, respectively (pathways 3 and 4).

Molecular dynamics and density functional theory studies of substrate binding and catalysis of human brain aspartoacylase.

The active-site dynamics of human brain aspartoacylase (hASPA) complexed with its substrate (N-acetyl-L-aspartate) has been studied using a hybrid quantum mechanical/molecular mechanical (QM/MM) approach based on the self-consistent charge-density functional tight-binding (SCC-DFTB) model. The Michaelis complex, which is constructed from a recent X-ray structure of the human brain aspartoacylase with a stable tetrahedral intermediate analogue, is reproduced in 1ns molecular dynamics simulations at 300K. The simulation shows that the substrate is tightly held in the active site by a hydrogen bond network and the putative nucleophilic water molecule is reasonably close to the nucleophilic center.

Altered expression of inflammatory cytokine receptors in response to LPS challenge through interaction between intestinal epithelial cells and lymphocytes of Peyer's patch.

The intense innate immunological activities occurring at the enteric mucosal surface involve interactions between intestinal epithelial cells and immune cells. Our previous studies have indicated that Peyer's patch lymphocytes may modulate intestinal epithelial barrier and ion transport function in homeostasis and host defense via cell-cell contact as well as cytokine signaling. The present study was undertaken using the established co-culture system of Caco-2 epithelial cells with lymphocytes of Peyer's patch to investigate the expression of IL-8 and IL-6 cytokines and cytokine receptors in the co-culture system after challenge with Shigella F2a-12 lipopolysaccharide (LPS).

Theoretical studies on the water-assisted hydrolysis of N,N-dimethyl-N'-(2',3'-dideoxy-3'-thiacytidine) formamidine with three water molecules.

The water-assisted hydrolysis mechanism of N,N-dimethyl-N'-(2',3'-dideoxy-3'-thiacytidine) formamidine (MFA-3TC) with three water molecules was studied by use of computational techniques. Optimized structures for all of the stationary points in the gas phase were investigated using the B3LYP/6-31+G(d,p) method. Single-point energies were determined employing the ab initio MP2 method in conjunction with the 6-311++G(d,p) basis set.

[Expression of mouse CD1.1 in CHO cells and its stimulatory function on NKT cells].

Aim: To get cell lines which express mouse CD1.1 (mCD1.1) stably and to study the stimulatory effects of mCD1.

Interaction between enteric epithelial cells and Peyer's patch lymphocytes in response to Shigella lipopolysaccharide: effect on nitric oxide and IL-6 release.

Aim: To investigate the effect of interaction between enteric epithelial cells and lymphocytes of Peyer's patch on the release of nitric oxide (NO) and IL-6 in response to Shigella lipopolysaccharide (LPS).

Methods: Human colonic epithelial cells (Caco-2) were mixed cocultured with lymphocytes of Peyer's patch from wild-type (C57 mice) and inducible NO synthase knockout mice, and challenged with Shigella F2a-12 LPS. Release of NO and mIL-6 was measured by Griess colorimetric assay and enzyme-linked immunosorbent assay (ELISA), respectively.

[The observation of the lymphocyte phenotype change in different lymphoid tissues of mice after intranasal immunization with bivalent Shigella vaccines].

Aim: To observe the changes of lymphocyte phenotype in different lymphoid tissues of mice at various time after intranasal immunization with bivalent Shigella vaccines.

Methods: BALB/c mice were randomly divided into three groups, 30 mice per group. Mice were intranasally immunized respectively with PBS, FSM-2117 or FS-5416 four times (bacterial number was sequentially 5x10(6), 1x10(7),4x10(7)and 4x10(7)CFU/mouse) with two week intervals.

Modulation of human enteric epithelial barrier and ion transport function by Peyer's patch lymphocytes.

Aim: To investigate the role of Peyer's patch lymphocytes in the regulation of enteric epithelial barrier and ion transport function in homeostasis and host defense.

Methods: Mouse Peyer's patch lymphocytes were co-cultured with human intestinal epithelial cell line Caco-2 either in the mixed or separated (isolated but permeable compartments) culture configuration. Barrier and transport functions of the Caco-2 epithelial monolayers were measured with short-circuit current (Isc) technique.

Molecular Cloning of Human Interleukin-5 cDNA and Its Expression in E. coli.

hIL-5 cDNA was amplified through reverse transcription-polymerase chain reaction from peripheral blood lymphocytes induced with PMA and calcium ionophore A23187. The hIL-5 fragment was cloned into pUC18 and its sequence was identified to be hIL-5 cDNA sequence. The fragment which encodes hIL-5 mature polypeptide was amplified and cloned into pBV220 to express hIL-5 recombinant protein in E.