1.Protective effect of brain-derived neurotrophic factor on high dose glutamate-injured rat cortical neurons and its mechanism
Pingyun QIAO ; Jiangbao ZHOU ; Xiaoxiao XU ; Peng WU ; Huichun ZHANG
Journal of Third Military Medical University 2003;0(14):-
Objective To explore the protective effect of brain-derived neurotrophic factor (BDNF) on cultured rat cortical neurons against glutamate (Glu)-induced injury and its mechanism. Methods Cortical neurons were primarily cultured from 1-day-old newborn Sprague-Dawley rats and then cultured for 7 d. The cortical neurons were divided randomly into 3 groups: control group,Glu group and BDNF group after identified with neuron-specific enolase (NSE) immunostaining. The cells of BDNF were treated with 50 ng/ml BDNF on day 6 for 24 h followed by cultured with 50 ?mol/L Glu for 0.5 h. While,the cells of Glu group were cultured with 50 ?mol/L Glu for 0.5 h on day 7. The control cells received no such treatments. On day 8,cell viability were determined by the colorimetric MTT assay. The morphological features of the neuron cells were observed under AO/EB fluorescence microscopy. Expressions of p75NTR,JNK and ERK were observed using Western blot analysis. Results On day 8,the primary cortical neurons grew well. BDNF protected cortical neural cells from Glu injury. Cell viability of BDNF group was (1.14?0.06),significantly higher than that of Glu group (0.72?0.10,P
2.Inhibitory effects of simeprevir on Staphylococcusepidermidis and itsbiofilm in vitro.
Yingjia LI ; Chaoni CAI ; Zixin LIU ; Xichang TANG ; Lin QU ; Yuan WU ; Pingyun WU ; Yao DUAN ; Pengfei SHE
Journal of Central South University(Medical Sciences) 2023;48(6):868-876
OBJECTIVES:
Staphylococcus epidermidis (S. epidermidis) is a Gram-positive opportunistic pathogen that often causes hospital infections. With the abuse of antibiotics, the resistance of S. epidermidis gradually increases, and drug repurposing has become a research hotspot in the treating of refractory drug-resistant bacterial infections. This study aims to study the antimicrobial and antibiofilm effects of simeprevir, an antiviral hepatitis drug, on S. epidermidis in vitro.
METHODS:
The micro-dilution assay was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of simeprevir against S. epidermidis. Crystal violet staining assay was used to detect the biofilm inhibitory effect of simeprevir. The antimicrobial activity of simeprevir against S. epidermidis and its biofilm were explored by SYTO9/PI fluorescent staining. The combined effect between simeprevir and gentamycin was assessed by checkerboard assay and was confirmed by time-inhibition assay.
RESULTS:
Simeprevir showed significant antimicrobial effects against S. epidermidis type strains and clinical isolates with the MIC and MBC at 2-16 μg/mL and 4-32 μg/mL, respectively. The antimicrobial effects of simeprevir were confirmed by SYTO9/PI staining. Simeprevir at MIC could significantly inhibit and break the biofilm on cover slides. Similarly, simeprevir also significantly inhibit the biofilm formation on the surface of urine catheters either in TSB [from (0.700±0.020) to (0.050±0.004)] (t=54.03, P<0.001), or horse serum [from (1.00±0.02) to (0.13±0.01)] (t=82.78, P<0.001). Synergistic antimicrobial effect was found between simeprevir and gentamycin against S. epidermidis with the fractional inhibitory concentration index of 0.5.
CONCLUSIONS
Simeprevir shows antimicrobial effect and anti-biofilm activities against S. epidermidis.
Humans
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Simeprevir
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Antiviral Agents
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Anti-Bacterial Agents/pharmacology*
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Cross Infection
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Gentamicins