Effect of Xiaoxuming Decoction on synaptic plasticity following acute cerebral ischemia-reperfusion in rats / 中国中药杂志

This study aims to explore the effect of Xiaoxuming Decoction on synaptic plasticity in rats with acute cerebral ischemia-reperfusion. A rat model of cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion(MCAO). Rats were randomly assigned into a sham group, a MCAO group, and a Xiaoxuming Decoction(60 g·kg~(-1)·d~(-1)) group. The Longa score was rated to assess the neurological function of rats with cerebral ischemia for 1.5 h and reperfusion for 24 h. The 2,3,5-triphenyltetrazolium chloride(TTC) staining and hematoxylin-eosin(HE) staining were employed to observe the cerebral infarction and the pathological changes of brain tissue after cerebral ischemia, respectively. Transmission electron microscopy was employed to detect the structural changes of neurons and synapses in the ischemic penumbra, and immunofluorescence, Western blot to determine the expression of synaptophysin(SYN), neuronal nuclei(NEUN), and postsynaptic density 95(PSD95) in the ischemic penumbra. The experimental results showed that the modeling increased the Longa score and led to cerebral infarction after 24 h of ischemia-reperfusion. Compared with the model group, Xiaoxuming Decoction intervention significantly decreased the Longa score and reduced the formation of cerebral infarction area. The modeling led to the shrinking and vacuolar changes of nuclei in the brain tissue, disordered cell arrangement, and severe cortical ischemia-reperfusion injury, while the pathological damage in the Xiaoxuming Decoction group was mild. The modeling blurred the synaptic boundaries and broadened the synaptic gap, while such changes were recovered in the Xiaoxuming Decoction group. The modeling decreased the fluorescence intensity of NEUN and SYN, while the intensity in Xiaoxuming Decoction group was significantly higher than that in the model group. The expression of SYN and PSD95 in the ischemic penumbra was down-regulated in the model group, while such down-regulation can be alleviated by Xiaoxuming Decoction. In summary, Xiaoxuming Decoction may improve the synaptic plasticity of ischemic penumbra during acute cerebral ischemia-reperfusion by up-regulating the expression of SYN and PSD95.

The Application of Heating Effect in Breeding of Microorganism / 微生物学通报

Advances in mechanism and application of the heating effect in breeding of microorganism are reviewed in this paper. Heat produces mutagenesis effect and screening effect. Heating mutagenesis effect is occurred through the substitution of G-C base pair induced by heat, and heating screening effect produces higher forward mutation rate induced by other mutagens.

Isolation and Purification of Antibiotic from the Fermentation Broth of Micromonospora carbonacea JXNU-1 and Its Physical-chemical Properties / 微生物学通报

Based on the strain of Micromonospora carbonacea JXNU-1 with board-spectrum antimicrobial activity, the technology for the isolation and purification of antibiotic from the fermentation broth of the Micromonospora carbonacea, and its physical-chemical properties were studied. The results showed that, the antibiotic was stable under the condition of high temperature and alkali, but not in acid solution. After the pretreatment of centrifugation and filtration to remove the cells and lipids, the antibiotic was absorbed to negative exchange resin, and the impurity was excluded when 2 mol/L NaCl was used as primary eluent. The antibiotic could be eluted with 20% alcohol as eluent, and the eluting speed of the antibiotic was greatly accelerated as 2 mol/L NaCl was added into 20% alcohol as final eluent. Aqueous solution of the antibiotic was yielded from the alcohol-salt eluant by decompression concentration to wipe off alcohol and by dialysis to exclude salt. One active component was detected in antibiotic solution by paper chromatography, and theHPLC purity was over 99%. As the antibiotic shows positive color-forming reaction to Molish reagents, Benedict’s reagents and Diohenvlamine reagents, combined with the characteristics of absorption spectra, it is deduced that the antibiotic belongs to nucleoside antibiotics.

Isolation and Identification of a Strain of Micromonosporawith Broad-spectrum Antimicrobial Activity / 微生物学通报

A rare strain of actinomycetes, with broad-spectrum antimicrobial activity, was isolated from the soil samples from the farmland in the area of Yaohu lake in Nanchang. The information about the taxonomic identification, such as the morphology, physiological properties, cell components and 16S rRNA gene se-quences, suggested that the rare strain of actinomycetes was identified as Micromonospora carbonacea.