Comparative effect of ciprofloxacin and moxifloxacin on the modulation of bile acid profiles and gut microbiota in rats

Abstract Fluoroquinolones are an important class of antimicrobial agents to manage infectious diseases. However, knowledge about how host bile acids are modified by fluoroquinolones is limited. We investigated and compared the impact of fluoroquinolones on circulating bile acid profiles and gut microbiota from in vivo studies. We administered ciprofloxacin (100 mg/kg/day) or moxifloxacin (40 mg/kg/day) orally to male Wistar rats for seven days. Fifteen bile acids (BAs) from the serum and large intestine were quantified by HPLC-MS/MS. The diversity of gut microbiota after ciprofloxacin and moxifloxacin treatment was analyzed using high-throughput, next-generation sequencing technology. The two fluoroquinolone-treated groups had different BA profiles. Ciprofloxacin significantly reduced the hydrophobicity index of the BA pool, reduced secondary BAs, and increased taurine-conjugated primary BAs in both the serum and large intestine as compared with moxifloxacin. Besides, ciprofloxacin treatment altered intestinal microbiota with a remarkable increase in Firmicutes to Bacteroidetes ratio, while moxifloxacin exerted no effect. What we found suggests that different fluoroquinolones have a distinct effect on the host BAs metabolism and intestinal bacteria, and therefore provide guidance on the selection of fluoroquinolones to treat infectious diseases.

Mechanism of inhibiting proliferation of tumor cells by a new tetrahydroisoquinoline compound SYT-1 / 药学学报

In this study, we investigated the inhibitory effect of SYT-1, a new compound of tetrahydroisoquino-line, on tumor cell proliferation and underlying mechanisms. Cell counting kit-8 (CCK-8) method was used to detect cell proliferation; clone formation experiment was used to detect cell clone formation ability; JC-1 probe was used to detect cell mitochondrial membrane potential; 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) probe was used to detect intracellular reactive oxygen species; Annexin V-FITC/PI (fluorescein isothiocyanate/propidium) counterstaining method was used to detect apoptosis; Western blot assay was used to detect the expression level of related proteins. The experimental results show that SYT-1 has a significant inhibitory effect on the proliferation of six human-derived cancer cells. Among them, the inhibitory effect on breast cancer MCF-7 cells is the strongest, the half maximal inhibitory concentration (IC50) of SYT-1 of 48 h administration on MCF-7 cells is 5.87 μmol·L-1, which is better than that of cisplatin (8.92 μmol·L-1). Further studies have shown that SYT-1 can dose-dependently inhibit the monoclonal formation ability of MCF-7 cells, and can cause the mitochondrial membrane potential of the cells to decrease and the level of reactive oxygen species to increase. In addition, SYT-1 can significantly inhibit the activation of PI3K-Akt (phosphatidylinositol 3-kinase/protein kinase B) signaling pathway and induce apoptosis of MCF-7 cells. The above research results show that, as a new type of tetrahydroisoquinoline compound, SYT-1 has the potential to inhibit tumor cell proliferation.

Influence of BMP4 on Regulation of Cell Cycle and Apoptosis of Hematopoietic Stem Cells/Progenitor Cells and Its Mechanism in Chemotherapy-Induced Myelosuppression / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of bone morphogenetic protein 4(BMP4) on the cell cycle and apoptosis of hemaropoictic stem and progenitor cells (HSPC) in conditions of 5-fluorouracil (5-FU)-inducing bone marrow suppression and stress hemogenesis, and its possible mechanism.@*METHODS@#The C57BL transgenic mice with BMP4 overexpression were established and were enrolled in transgenic group (BMP4 group), at the same time the wild type mice matching in age, sex and body weight were selected and were enrolled in control group (WT group). The bone marrow suppression was induced by injection with 5-FU in dose of 150 mg/kg, then the nucleated cells were isolated from bone marrow. After the HSPCs were markered with C-kit/sca-1 fluorescent antibodies, the changes of cell cycle and apoptosis of HSPC were detected by Aunexin V/PI and Ki67/DAPI double staining; the cell cycle-essociated hemotopoietic regulatory factors were detected by RT-qPCR.@*RESULTS@#Under physiologic status, there were no significant differences in cell cycle and apoptotic rate of HSPC between WT group and BMP-4 group. After the bone marrow was suppressed, the ratio of HSPC at G0 phase in BMP4 group significantly decreased(P＜0.05); the apoptosis rate of HSPC significantly increased(P＜0.05); the mRNA expression levels of hypoxia-inducing factor Hif-1α and chemotactic factor CXCL12 in stroma of BMP4 group were down-regulated significanfly(P＜0.05).@*CONCLUSION@#Under non-physiologic conditions such as stress hemogenesis or bone marrow suppression, the up-regulation of BMP4 can promote HSPC into cell cycle and apoptosis of HSPC, moreover, the BMP4 may play a regulatory role for cell cycle of HSPC through direct or indirect down-regulation of Hif-1α and CXCL-12 expressions.

Detecting human adenoviruses in respiratory samples collected from children with acute respiratory infections by loop-mediated isothermal amplification / 中华儿科杂志

<p><b>OBJECTIVE</b>To establish a rapid and reliable loop-mediated isothermal amplification (LAMP) method for detecting adenoviruses (ADV)in respiratory samples collected from children with acute respiratory infections.</p><p><b>METHOD</b>According to the sequences of hexon genes of common adenovirus serotypes (Ad3, Ad7, and Ad14) downloaded from GenBank, primers were designed and LAMP method for detecting adenovirus DNA was developed. Sensitivity of the LAMP method was evaluated by using constructed recombinant plasmid DNA with gene fragment from hexon of ADV3, and specificity was tested through cross-reaction with other viruses. Then 11 ADV strains isolated from clinical specimens using tissue cultures were tested by LAMP method. A total of 108 nasopharyngeal aspirates from hospitalized patients with acute respiratory infections which had been tested by direct immunofluorescence assay (DFA), including 36 for ADV positive and 72 for ADV negative, were tested by both LAMP method and multiplex nested PCR.</p><p><b>RESULT</b>Analysis for sensitivity indicated that this LAMP method can detect 1.9×10(2)copies/ml of DNA, and no amplification was shown in DNA or cDNA of other viruses, which revealed that the specificity of the LAMP method is high. For 108 specimens which had been tested by DFA, 34 out of the 36 ADV positive specimens showed positive signal within 90 minutes using LAMP. Five out of 72 negative specimens by DFA were positive using LAMP; 39 out of the 41 ADV positive specimens by multiplex nested PCR showed positive signal using LAMP, including 19 for Ad3 and 20 for Ad7; 67 negative specimens confirmed by multiplex nested PCR showed negative signal using LAMP. The total consistency rate of DFA and LAMP method for detecting ADV was 93.5%, and the total coincidence rate of multiplex nested PCR and LAMP method for detecting ADV was 98.1%.</p><p><b>CONCLUSION</b>A new, sensitive, accurate and rapid method for detecting human adenovirus from nasopharyngeal aspirates by LAMP was developed, which should be a potential method for rapid detection of ADV from respiratory tract of children in clinical diagnosis of ADV infection.</p>

Sequence and antigenicity analysis for VP4s of EV71 strains isolated from Children in Beijing / 病毒学报

In order to learn about the correlation between the sequences of VP4 of EV71 and clinical symptoms of patients and analyze the antigenicity of VP4 of EV71, as well as the cross-reactivity with VP4 of CA16, the sequences of VP4 gene from 10 EV71 strains isolated from infants and children with hand, foot and mouth diseases (HFMD) during 2007 to 2009 were determined through standard molecular cloning protocols, and the results were analyzed by EditSeq and MegAlign of DNAStar. Full-length genes of VP4s of EV71 and CA16 were amplified from virus isolates and expressed in E. coli. Then the expressed VP4s were used as antigens to detect IgG antibody in 189 sera samples from people taking health check up and patients of non-HFMD by Western-Blot. They were also used to detect IgM antibody in 14 of sera samples from infants and children with EV71 infection and 12 of sera samples from those with CA16 infection. The nucleotides identities among these 10 sequences of VP4s isolated in our lab were 94.20% - 100.00% and the deduced amino acids were identical. There was no consistent divergence between the sequences of serious cases and those from general HFMD cases. Phylogenetic analysis based on VP4s indicated that these 10 VP4s of EV71 belonged to C4. The nucleotide identities between EV71 VP4 (s67) and CA16 VP4 (s401) was 69.60% and the deduced amino acids identities was 78.60%. In the detection of IgG, the sera-positive rate for EV71 VP4 was 38.10% and the sera-positive rate of CA16 VP4 was 58.20%. The difference in the sera-positive rate between them was significant (chi2 = 15.30, P < 0.01), suggesting that the expressed VP4s of EV71 and CA16 were of good antigenicity and not cross-reactive. There was no positive reaction detected for IgM against VP4s for EV71 or CA16. The data from this study reveal important information for the further study of EV71.