Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhi...Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.展开更多
Aim: To evaluate the effect of a protein synthesis inhibitor cycloheximide on arresting activity in spermato-genesis and sperm count in male rats. Methods: The study used seminiferous tubule (ST) segments from adult r...Aim: To evaluate the effect of a protein synthesis inhibitor cycloheximide on arresting activity in spermato-genesis and sperm count in male rats. Methods: The study used seminiferous tubule (ST) segments from adult rats cultured in vitro with or without cycloheximide to condition culture media, which have been concentrated, size fractioned (30-50 kDa) and administered 7 days to adult rats by intraperitoneal injections. The effects on testicular and epididymal weights, spermatogenesis and epididymal sperm count were determined. Results: The fraction (30-50 kDa), named arresting, obtained from the culture without cycloheximide decreased testicular and epididymal weights (P<0.01) and reduced the epididymal sperm count significantly. Study of the spermatogenic cycle by transillumination showed spermatogenic arrest at stage VII in rats treated with arresting compared to that observed in controls. The length of stage VII in the group receiving the seminiferous tubules culture media with cycloheximide (30-50 KDa CHX-STCM fraction) was similar to control. Conclusion: The difference in the effect may be the result of the presence or absence of arresting, a protein secreted by the tubules.展开更多
OBJECTIVE To investigate the protective effect of Codonopsis Pilosula Polysaccharide(CPPS)on improving of the memory consolidation disorder induced by Cycloheximide and its possible mechanisms in mice.METHODS The mice...OBJECTIVE To investigate the protective effect of Codonopsis Pilosula Polysaccharide(CPPS)on improving of the memory consolidation disorder induced by Cycloheximide and its possible mechanisms in mice.METHODS The mice was divided into five groups,as normal control group,cycloheximid model group,piracetam positive control group,CPPS 300 mg·kg^(-1) group,and CPPS150 mg·kg^(-1) group.The mice respectively were given saline,piracetam,and CPPS for 15 d.The memory consolidation disorder model in mice was established by ip.Cyclohexylamine,and orally administered CPPS(300 mg·kg^(-1) or 150 mg·kg^(-1))every day.Then experimental groups were subjected Morris Water Maze test.Western blotting analysis were used to analysis the expression of Ca MKⅡ/CREB signaling pathways.RESULTS Morris water maze experiment showed that cyclohexylamine can cause memory consolidation disorder(P<0.01),and giving piracetam and CPPS(300 mg·kg-1)can improve spatial memory impairment in mice(P<0.05,P<0.01).Western blotting experiment results show that compared with normal control group,Ca MKⅡand CREB contents of brain in model group mice had significant decreased(P<0.001);Compared with model group,Ca MKⅡand CREB contents of brain tissue in piracetam and CPPS groups increased significantly(P<0.05,P<0.01,P<0.001).CONCLUSION Cycloheximide can induce the memory consolidation disorder,and its effect in mice related to Ca MK/CREB signaling pathways.CPPS can improved this memory disorder by influence Ca MKⅡ/CREB signaling pathways.展开更多
Objective:To isolate and screen Actinomycetes from Lagos Lagoon soil sediments for antibiotic production.Methods:Soil samples were collected from four different locations of Lagos Lagoon and were dried for 2 weeks.Act...Objective:To isolate and screen Actinomycetes from Lagos Lagoon soil sediments for antibiotic production.Methods:Soil samples were collected from four different locations of Lagos Lagoon and were dried for 2 weeks.Actinomycetes were isolated by serial dilution using spread plate method on starch casein and Kuster’s agar supplemented with 80μg/mL cycloheximide to prevent fungal growth.The plates were incubated at 28°C for 1-2 weeks.Isolates were selected based on their cultural characteristics as well as their Gram’s reaction and subcultured on same media for isolation and incubated at 28°C for 3 days.Pure cultures were maintained on nutrient agar slants at 4°C.Thereafter,they were inoculated into starch casein and Kuster’s broth media and incubated at 28°C for 8 days.The resulting crude extracts were screened for antimicrobial activity against the following microorganisms:methicillin resistant Staphylococcus aureus,Staphylococcus aureus ATCC 29213,Escherichia coli ATCC 29522,Pseudomonas aeruginosa ATCC 27853,Candida albicans and Enterococcus faecalis ATCC 29212.Coagulase-negative staphylococci isolated from HIV patients were also used(Staphylococcus warneri,Staphylococcus xylosus and Staphylococcus epidermidis).Extraction of secondary metabolites was carried out and analysed using gas chromatography-mass spectrometer.Results:All the isolates displayed varying antimicrobial activity against at least one of the test organisms.Himalomycin A was identified in the extract from isolate ULS7.The gas chromatography-mass spectrometer data analysis showed the antibiotic profile of these isolates.Conclusions:The isolate ULS7 was found to display the highest antimicrobial activity against the test organisms.展开更多
The strain LWYZ003, which can restrain multiple pathogens, was screened from the sediment of the ocean and identified as Bacillus amyloliquefaciens. Large-scale fermentation and modern chromatographic separation techn...The strain LWYZ003, which can restrain multiple pathogens, was screened from the sediment of the ocean and identified as Bacillus amyloliquefaciens. Large-scale fermentation and modern chromatographic separation technologies(macroporous resin column chromatography, silica gel column chromatography, thin-layer chromatography and high-performance liquid chromatography) were used to separate antimicrobial products from the fermentation broth of marine-derived Bacillus amyloliquefaciens LWYZ003. Bioactive-guided separation was used in the term of seeking antimicrobial products from the secondary metabolites of Bacillus amyloliquefaciens LWYZ003. As a result, two natural products cycloheximide( 1) and trehalose( 2) were obtained. Their structures were elucidated by Fourier transform infrared spectroscopy, high-resolution mass spectrometry, ~1 H and ^(13) C nuclear magnetic resonance analysis. In the cylinder plate method, compound 1 exhibited stronger antimicrobial activities than compound 2 against Micrococcus luteus, and also exhibited wider antimicrobial spectrum than compound 2. In conclusion, isolation of bioactive secondary metabolites from marine Bacillus sp. has enormous potentials in finding suitable antibiotics to inhibit multiple pathogens.展开更多
Summary： To systematically evaluate the importance of protein synthesis in ischemic preconditioning （PC）-induced ischemic tolerance （IT）, temporary middle cerebral artery occlusion （MCAO） by Longa （20 min） wa...Summary： To systematically evaluate the importance of protein synthesis in ischemic preconditioning （PC）-induced ischemic tolerance （IT）, temporary middle cerebral artery occlusion （MCAO） by Longa （20 min） was used for PC （ischemic precondioning）. Twenty-four hours of reperfusion was allowed after PC and before permanent MCAO to establish ischemic tolerance （IT） to compare with non-PC （sham-operated） rats （n=5 for each group）. Infarct size and neurological deficits were measured 24 h after PMCAO. Samples of brain were taken for the determination of HSP70 expression by Western blot analysis. The effects of the protein synthesis inhibitor cycloheximide administered just before PC or administered long after PC but just before PMCAO on IT were also determined （n=5 for each group）. Our results showed that hemispheric infarct was significantly reduced （P〈0.01） only if PC was performed after 24 h, and PC significantly （P〈0.05） reduced neurological deficits （similar to reductions in infarct size）. Cycloheximide eliminated ischemic PC-induced IT effects on both brain injury and neurological deficits if administered before PC but not if administered long after PC but before PMCAO. PC produced no brain injury but did increase HSP70 protein 24 h after PC. Cycloheximide eliminated that effect. The results suggest that PC is a powerful inducer of ischemic brain tolerance as reflected by the preservation of brain tissue and motor function. PC induces IT that is dependent on de novo protein synthesis.展开更多
It has been known for years that steroids （e. g. hydrocortisone and dexamethasone） have significant inhibitory effects on macrophage （M φ） activation for tumor cytotoxicity and secretion of interleukin 1, tumor n...It has been known for years that steroids （e. g. hydrocortisone and dexamethasone） have significant inhibitory effects on macrophage （M φ） activation for tumor cytotoxicity and secretion of interleukin 1, tumor necrosis factor-α（TNF-α） and prostaglandin E<sub>2</sub>. The mechanism of inhibition is, however, not well understood. We report here that the dexamethasone-induced inhibition of M φ activation for tumor cytotoxicity could be partially antagonized by high concentrations of activators and blocked by inhibitors of protein synthesis and energy metabolism.展开更多
文摘Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.
文摘Aim: To evaluate the effect of a protein synthesis inhibitor cycloheximide on arresting activity in spermato-genesis and sperm count in male rats. Methods: The study used seminiferous tubule (ST) segments from adult rats cultured in vitro with or without cycloheximide to condition culture media, which have been concentrated, size fractioned (30-50 kDa) and administered 7 days to adult rats by intraperitoneal injections. The effects on testicular and epididymal weights, spermatogenesis and epididymal sperm count were determined. Results: The fraction (30-50 kDa), named arresting, obtained from the culture without cycloheximide decreased testicular and epididymal weights (P<0.01) and reduced the epididymal sperm count significantly. Study of the spermatogenic cycle by transillumination showed spermatogenic arrest at stage VII in rats treated with arresting compared to that observed in controls. The length of stage VII in the group receiving the seminiferous tubules culture media with cycloheximide (30-50 KDa CHX-STCM fraction) was similar to control. Conclusion: The difference in the effect may be the result of the presence or absence of arresting, a protein secreted by the tubules.
基金supported by National Natural Science Foundation(81202192)Fund of Hebei Provincial Health Bureau(20130037)
文摘OBJECTIVE To investigate the protective effect of Codonopsis Pilosula Polysaccharide(CPPS)on improving of the memory consolidation disorder induced by Cycloheximide and its possible mechanisms in mice.METHODS The mice was divided into five groups,as normal control group,cycloheximid model group,piracetam positive control group,CPPS 300 mg·kg^(-1) group,and CPPS150 mg·kg^(-1) group.The mice respectively were given saline,piracetam,and CPPS for 15 d.The memory consolidation disorder model in mice was established by ip.Cyclohexylamine,and orally administered CPPS(300 mg·kg^(-1) or 150 mg·kg^(-1))every day.Then experimental groups were subjected Morris Water Maze test.Western blotting analysis were used to analysis the expression of Ca MKⅡ/CREB signaling pathways.RESULTS Morris water maze experiment showed that cyclohexylamine can cause memory consolidation disorder(P<0.01),and giving piracetam and CPPS(300 mg·kg-1)can improve spatial memory impairment in mice(P<0.05,P<0.01).Western blotting experiment results show that compared with normal control group,Ca MKⅡand CREB contents of brain in model group mice had significant decreased(P<0.001);Compared with model group,Ca MKⅡand CREB contents of brain tissue in piracetam and CPPS groups increased significantly(P<0.05,P<0.01,P<0.001).CONCLUSION Cycloheximide can induce the memory consolidation disorder,and its effect in mice related to Ca MK/CREB signaling pathways.CPPS can improved this memory disorder by influence Ca MKⅡ/CREB signaling pathways.
文摘Objective:To isolate and screen Actinomycetes from Lagos Lagoon soil sediments for antibiotic production.Methods:Soil samples were collected from four different locations of Lagos Lagoon and were dried for 2 weeks.Actinomycetes were isolated by serial dilution using spread plate method on starch casein and Kuster’s agar supplemented with 80μg/mL cycloheximide to prevent fungal growth.The plates were incubated at 28°C for 1-2 weeks.Isolates were selected based on their cultural characteristics as well as their Gram’s reaction and subcultured on same media for isolation and incubated at 28°C for 3 days.Pure cultures were maintained on nutrient agar slants at 4°C.Thereafter,they were inoculated into starch casein and Kuster’s broth media and incubated at 28°C for 8 days.The resulting crude extracts were screened for antimicrobial activity against the following microorganisms:methicillin resistant Staphylococcus aureus,Staphylococcus aureus ATCC 29213,Escherichia coli ATCC 29522,Pseudomonas aeruginosa ATCC 27853,Candida albicans and Enterococcus faecalis ATCC 29212.Coagulase-negative staphylococci isolated from HIV patients were also used(Staphylococcus warneri,Staphylococcus xylosus and Staphylococcus epidermidis).Extraction of secondary metabolites was carried out and analysed using gas chromatography-mass spectrometer.Results:All the isolates displayed varying antimicrobial activity against at least one of the test organisms.Himalomycin A was identified in the extract from isolate ULS7.The gas chromatography-mass spectrometer data analysis showed the antibiotic profile of these isolates.Conclusions:The isolate ULS7 was found to display the highest antimicrobial activity against the test organisms.
基金supported by the National Basic Research Program of China ("973" Program) (no. 2012CB721105)the Major Research Plan of Tianjin, China (no. 16YFXTSF00460)
文摘The strain LWYZ003, which can restrain multiple pathogens, was screened from the sediment of the ocean and identified as Bacillus amyloliquefaciens. Large-scale fermentation and modern chromatographic separation technologies(macroporous resin column chromatography, silica gel column chromatography, thin-layer chromatography and high-performance liquid chromatography) were used to separate antimicrobial products from the fermentation broth of marine-derived Bacillus amyloliquefaciens LWYZ003. Bioactive-guided separation was used in the term of seeking antimicrobial products from the secondary metabolites of Bacillus amyloliquefaciens LWYZ003. As a result, two natural products cycloheximide( 1) and trehalose( 2) were obtained. Their structures were elucidated by Fourier transform infrared spectroscopy, high-resolution mass spectrometry, ~1 H and ^(13) C nuclear magnetic resonance analysis. In the cylinder plate method, compound 1 exhibited stronger antimicrobial activities than compound 2 against Micrococcus luteus, and also exhibited wider antimicrobial spectrum than compound 2. In conclusion, isolation of bioactive secondary metabolites from marine Bacillus sp. has enormous potentials in finding suitable antibiotics to inhibit multiple pathogens.
文摘Summary： To systematically evaluate the importance of protein synthesis in ischemic preconditioning （PC）-induced ischemic tolerance （IT）, temporary middle cerebral artery occlusion （MCAO） by Longa （20 min） was used for PC （ischemic precondioning）. Twenty-four hours of reperfusion was allowed after PC and before permanent MCAO to establish ischemic tolerance （IT） to compare with non-PC （sham-operated） rats （n=5 for each group）. Infarct size and neurological deficits were measured 24 h after PMCAO. Samples of brain were taken for the determination of HSP70 expression by Western blot analysis. The effects of the protein synthesis inhibitor cycloheximide administered just before PC or administered long after PC but just before PMCAO on IT were also determined （n=5 for each group）. Our results showed that hemispheric infarct was significantly reduced （P〈0.01） only if PC was performed after 24 h, and PC significantly （P〈0.05） reduced neurological deficits （similar to reductions in infarct size）. Cycloheximide eliminated ischemic PC-induced IT effects on both brain injury and neurological deficits if administered before PC but not if administered long after PC but before PMCAO. PC produced no brain injury but did increase HSP70 protein 24 h after PC. Cycloheximide eliminated that effect. The results suggest that PC is a powerful inducer of ischemic brain tolerance as reflected by the preservation of brain tissue and motor function. PC induces IT that is dependent on de novo protein synthesis.
文摘It has been known for years that steroids （e. g. hydrocortisone and dexamethasone） have significant inhibitory effects on macrophage （M φ） activation for tumor cytotoxicity and secretion of interleukin 1, tumor necrosis factor-α（TNF-α） and prostaglandin E<sub>2</sub>. The mechanism of inhibition is, however, not well understood. We report here that the dexamethasone-induced inhibition of M φ activation for tumor cytotoxicity could be partially antagonized by high concentrations of activators and blocked by inhibitors of protein synthesis and energy metabolism.
