2.Controlled release by novel lysostaphin-loaded hydroxyapatite/chitosan composites.
Jincheng WANG ; Bai XUE ; Kuikui GE ; Yihan WANG ; Guodong LI ; Qingshan HUANG
Acta Pharmaceutica Sinica 2014;49(9):1331-9
Lysostaphin is highly effective on eliminating methicillin resistant Staphylococcus aureus (MRSA). In order to achieve controlled release of lysostaphin, a biocompatible drug carrier is needed. Hydroxyapatite/chitosan (HA/CS) composites were chosen to carry lysostaphin and sample composites with different weight ratios of HA to CS, including 80/20, 70/30, 60/40, and 40/60, were prepared. Multiple analyses were performed to determine the structural and physicochemical properties of the composites, including scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. We immersed HA/CS composites loaded with 1 wt% lysostaphin to test in vitro release activity and cultured MC3T3-E1 cells to carry out biocompatibility test. The result of the release behavior of the composites revealed that the controlled release of lysostaphin from 60/40 HA/CS composites was the highest release rate of (87.4 ± 2.8)%, which lasted for 120 hours. In biocompatibility testing, MC3T3-E1 cells were able to proliferate on the surface of these composites, and the extract liquid from the composites could increase the growth of the cells. These results demonstrate the controlled release of lysostaphin from HA/CS composites and their biocompatibility, suggesting the potential application of these composites to bone injury and infection applications.
3.Breeding of Yeast Fusant for Efficient Ethanol Fermentation from Xylose
Jie LI ; Fan LI ; Chen-Guang LIU ; Jian-Gang REN ; Xin-Qing ZHAO ; Xue-Meng GE ; Feng-Wu BAI ;
China Biotechnology 2006;0(06):-
Yeast strains with improved ethanol yield are important for efficient bioconversion of lignocellulosic biomass for fuel ethanol.Candida shehatae CICC1766 was adapted to 4%(v/v)ethanol,and then subjected to UV mutagenesis.One respiration deficient mutant Rd-5 with improved xylose fermentation capability was selected.Protoplasts of Rd-5 were inactivated by UV treatment,followed by the PEG-mediated protoplast fusion with a Saccharomyces cerevisiae strain with good ethanol-fermenting capability.The xylose fermenting capability of the fusants was investigated,and the fusant F6 demonstrated good ethanol fermentation performance,producing 18.75g/L ethanol from 50g/L xylose with an ethanol yield of 0.375 or 73.4% of its theoretical value of 0.511.Comparing with its parent Candida shehatae strain,the ethanol yield of F6 was increased by 28%.
4.Controlled release by novel lysostaphin-loaded hydroxyapatite/chitosan composites.
Jin-Cheng WANG ; Bai XUE ; Kui-Kui GE ; Yi-Han WANG ; Guo-Dong LI ; Qing-Shan HUANG
Acta Pharmaceutica Sinica 2014;49(9):1331-1339
Lysostaphin is highly effective on eliminating methicillin resistant Staphylococcus aureus (MRSA). In order to achieve controlled release of lysostaphin, a biocompatible drug carrier is needed. Hydroxyapatite/chitosan (HA/CS) composites were chosen to carry lysostaphin and sample composites with different weight ratios of HA to CS, including 80/20, 70/30, 60/40, and 40/60, were prepared. Multiple analyses were performed to determine the structural and physicochemical properties of the composites, including scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. We immersed HA/CS composites loaded with 1 wt% lysostaphin to test in vitro release activity and cultured MC3T3-E1 cells to carry out biocompatibility test. The result of the release behavior of the composites revealed that the controlled release of lysostaphin from 60/40 HA/CS composites was the highest release rate of (87.4 ± 2.8)%, which lasted for 120 hours. In biocompatibility testing, MC3T3-E1 cells were able to proliferate on the surface of these composites, and the extract liquid from the composites could increase the growth of the cells. These results demonstrate the controlled release of lysostaphin from HA/CS composites and their biocompatibility, suggesting the potential application of these composites to bone injury and infection applications.
3T3 Cells
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Animals
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Biocompatible Materials
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Chitosan
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chemistry
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Delayed-Action Preparations
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Drug Carriers
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chemistry
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Durapatite
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chemistry
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Lysostaphin
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pharmacology
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Materials Testing
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Methicillin-Resistant Staphylococcus aureus
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Mice
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Microscopy, Electron, Scanning
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X-Ray Diffraction
5.Influence of floc size distribution on the ethanol tolerance of a self-flocculating yeast strain SPSC01.
Juanjuan LEI ; Xinqing ZHAO ; Chuang XUE ; Xumeng GE ; Fengwu BAI
Chinese Journal of Biotechnology 2008;24(2):309-314
Ethanol tolerance of self-flocculating yeast SPSC01 was studied in a 3-L bioreactor under fed-batch culture. Yeast floc populations with the average sizes around 100, 200, 300, and 400 microm were obtained by adjusting the mechanical stirring rates of the fermentation system. When subjected to 20% (V/V) ethanol shock for 6 h at 30 degrees C, the remained cell viability was 3.5%, 26.7%, 48.8% and 37.6% for the aforementioned four floc populations, respectively. The highest ethanol yield 85.5% was achieved for the 300 microm flocs, 7.2% higher than that of the 100 microm flocs. The amounts of trehalose and ergosterol (including free ergosterol and total ergosterol) were positively correlated with the average size distributions from 100 to 300 microm. However, in the 400 microm flocs, the content of trehalose and ergosterol decreased, which coincided with its reduced ethanol tolerance compared to that of the 300 microm flocs. Furthermore, when subjected to 15% (V/V) ethanol shock at 30 degrees C, the equilibrium nucleotide concentration and plasma membrane permeability coefficient(P') of the 300 microm flocs accounted for only 43% and 52% respectively of those of the 100 microm and 200 microm populations. The effect of floc size distribution on the ethanol tolerance of the self-flocculating yeast strain SPSC01 was closely related to plasma membrane permeability. An optimal floc size distribution with the highest ethanol tolerance and ethanol production level could be obtained by controlling mechanical stirring speed of the bioreactor, which provides basis for the process optimization of fuel ethanol production using this self-flocculating strain.
Bioreactors
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microbiology
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Drug Tolerance
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Ergosterol
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biosynthesis
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Ethanol
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metabolism
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pharmacology
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Fermentation
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Flocculation
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Industrial Microbiology
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methods
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Particle Size
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Trehalose
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biosynthesis
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Yeasts
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drug effects
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growth & development
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metabolism
6.Efficacy of lower dose rituximab therapy for idiopathic thrombocytopenic purpura..
Tao SUI ; Feng XUE ; Hai-Feng ZHAO ; Jing GE ; Hu ZHOU ; Lei ZHANG ; Jie BAI ; Ren-Chi YANG
Chinese Journal of Hematology 2010;31(3):161-163
OBJECTIVETo evaluate the effectiveness, safety as well as the immunological change (peripheral T cell subpopulation) in patients with idiopathic thrombocytopenic purpura (ITP) treated with lower dose rituximab.
METHODSTwenty-six patients with refractory ITP which were unresponsive to or relapse after steriod and IVIG treatment were treated with rituximab (100 mg per week for four weeks) and intravenous immunoglobulin (IVIG) treatment. Whole blood cell count, serum concentrations of IgG, IgM and IgA, platelet associated (PA)-IgG, PAIgA and PAIgM, peripheral T cell subpopulations, and B cells of CD19(+)/CD20(+) were detected before and after rituximab therapy.
RESULTSComplete response (CR) was achieved in 6 patients (23.1%), response (R) in 10 (38.5%), and non-response (NR) in 10 (38.5%). One patient relapsed after R. The median follow-up time was 5.5 (0.8 - 8) months. The median response and CR time were 27 (1 - 104) and 41 (4 - 109) days, respectively. After the therapy, the serum concentrations of IgG, IgA, IgM, T cells of CD3(+), CD3(+)CD4(+), CD3(+)CD8(+), CD3(-)CD56(+), CD4(+)CD25(+) and CD4(+)CD25(+)FOXP3(+) were not changed, the number of CD4(+)CD25(+)FOXP3(-) T cells decreased (P < 0.05) and CD19(+)CD20(+) B cells significantly decreased (P < 0.01). PAIgG was lower after treatment compared with that before treatment (P < 0.05). There were no severe adverse effects during rituximab therapy.
CONCLUSIONLower dose rituximab may be an effective and safe modality for patients with ITP.
Antibodies, Monoclonal, Murine-Derived ; therapeutic use ; B-Lymphocytes ; Humans ; Immunoglobulin G ; Purpura, Thrombocytopenic, Idiopathic ; immunology ; Rituximab
7.Preliminary study of patients with chronic mountain sickness by GC-TOF-MS based serum metabolomics analysis
feng Xue CAO ; zhong Zhen BAI ; Lan MA ; Shang MA ; li Ri GE
Chinese Journal of Pathophysiology 2017;33(9):1676-1682
AIM:To evaluate specific metabolomics profiles in the serum of patients with chronic mountain sickness (CMS) and to explore the potential metabolic biomarkers in the native Tibetans living on the Qinghai-Tibet Plateau.METHODS:A gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) approach as a metabolomics technique was used to evaluate metabolic differences.The native Tibetan CMS patients (n =10) and healthy Tibetan controls (n =10) were enrolled from YuShu in Qinghai province in this study.The serum samples were collected and analyzed by GC-TOF-MS coupled with a series of multivariate statistical analyses such as principal component analysis (PCA),partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA).RESULTS:The intergroup differences between CMS patients and control subjects have been observed.A list of differential metabolites and several top altered rnetabolic pathways have been identified.The levels of fumaric acid,an intermediate in the tricarboxylic acid (TCA) cycle,and inosine were highly upregulated in the CMS patients,suggesting a greater effort to hypoxic adaptation in high elevation area.Other differential metabolites,such as methyl phosphate,2-ketoadipate,lyxose and phytanic acid were also identified.Importantly,the differential metabolites possessed higher area under the ROC curve (AUC) values,indicating an excellent clinical ability for the prediction of CMS.Increased levels of amino acids (isoleucine,glycine,serine,L-cysteine,citrulline and trimethyllysine) were detected in CMS group,yet significantly decreased levels of sulfuric acid,oxamic acid,lyxose and glutamine were also detected in CMS group than those in control group.At the same time,the levels of ribose and glucose-1-phosphate were markedly elevated in CMS group (P < 0.05).CONCLUSION:The metabolic activities are significantly altered in the serum of CMS patients.High altitude hypoxia may act on the disturbed glucose metabolism and amino acid metabolism in part of the Tibetan triggered by CMS.
8.Prognostic value of tumor-infiltrating lymphocyte subtypes in residual tumors of patients with triple-negative breast cancer after neoadjuvant chemotherapy
Yu-Ge BAI ; Guo-Xuan GAO ; Hong ZHANG ; Shuang ZHANG ; Yin-Hua LIU ; Xue-Ning DUAN ; Ling XU
Chinese Medical Journal 2020;133(5):552-560
Background::After neoadjuvant chemotherapy (NAC), non-pathological complete response of breast cancer patients can benefit from tailored adjuvant chemotherapy. However, it is difficult to select patients with poorer prognosis for additional adjuvant chemotherapy to maximize the benefits. Our study aimed to explore whether the subtypes of tumor-infiltrating lymphocytes (TILs) in residual tumors (RT) is related to the prognosis of triple-negative breast cancer (TNBC) after NAC.Methods::Data from patients with primary TNBC consecutively diagnosed at the Breast Disease Center of Peking University First Hospital from 2008 to 2014 were retrieved, and the cases with RT in the breast after NAC were enrolled. TILs subtypes in RT were observed by double-staining immunohistochemistry, and counted with the median TILs value per square millimeter as the cut-off to define high versus low TILs density in each subtype. The relationships between the TIL density of each subgroup and the clinicopathological characteristics of the RT after NAC patients were analyzed by Fisher exact test. Disease-free survival (DFS) and overall survival (OS) were analyzed by the Kaplan-Meier method and log-rank statistics.Results::A total of 37 eligible patients were included in this study, and the median follow-up period was 50 months (range 17–106 months). There was no significant correlation between the infiltrate density of CD4 +, CD8 +, CD20 +, and CD68 + lymphocytes and clinic-pathological characteristics. Significantly better prognosis was observed in patients with high CD4 +-TILs (DFS: P = 0.005, OS: P = 0.021) and high CD8 +-TILs (DFS: P = 0.018) and low CD20 +-TILs (OS: P = 0.042). Further analysis showed that patients with CD4 +/CD20 + ratio greater than 1 (DFS: P = 0.001, OS: P = 0.002) or CD8 +/CD20 + ratio greater than 1 (DFS: P = 0.009, OS: P = 0.022) had a better prognosis. Conclusions::Subtypes of TILs in RT is a potential predictive biomarker of survival in TNBC patients after NAC.
9.Assessment of released acrosin activity as a measurement of the sperm acrosome reaction.
Rui-Zhi LIU ; Wan-Li NA ; Hong-Guo ZHANG ; Zhi-Yong LIN ; Bai-Gong XUE ; Zong-Ge XU
Asian Journal of Andrology 2008;10(2):236-242
AIMTo develop a method for assessing sperm function by measuring released acrosin activity during the acrosome reaction (AR).
METHODSHuman semen samples were obtained from 24 healthy donors with proven fertility after 3-7 days of sexual abstinence. After collection, samples were liquefied for 30 min at room temperature. Standard semen parameters were evaluated according to World Health Organization (WHO) criteria. Calcium ionophore A23187 and progesterone (P4) were used to stimulate the sperm to undergo AR. After treatment, sperm were incubated with the supravital dye Hoechst33258, fixed in a glutaraldehyde-phosphate-buffered saline solution, and the acrosomal status was determined by fluorescence microscopy with fluorescein isothiocyanate-labeled Pisum sativum agglutinin (FITC-PSA). The percentage of sperm undergoing AR (AR%) was compared to sperm acrosin activities as assessed by spectrocolorimetry. The correlation between AR% and acrosin activity was determined by statistical analysis.
RESULTSThe AR% and released acrosin activity were both markedly increased with A23187 and P4 stimulation. Sperm motility and viability were significantly higher after stimulation with P4 versus stimulation with A23187 (P < 0.001). There was a significant positive correlation between released acrosin activity and AR% determined by FITC-PSA staining (r=0.916, P < 0.001).
CONCLUSIONSpectrocolorimetric measurement of released acrosin activity might serve as a reasonable alternative method to evaluate AR.
Acrosin ; physiology ; Acrosome Reaction ; Adult ; China ; Humans ; Male ; Progesterone ; pharmacology ; Semen ; drug effects ; physiology ; Sperm Motility ; drug effects ; physiology
10.Anti-tumor activity of Erythrina variegata L. extract and its mechanism of action.
Hong ZHANG ; Jun-Feng XIANG ; Li TAN ; Wei DAI ; Ge BAI ; Yan LIU ; Xue-Li CAO ; Ya-Lin TANG
Acta Pharmaceutica Sinica 2009;44(12):1359-1363
The anti-tumor activities and mechanism of Erythrina variegata L. extract were investigated. Firstly, the MTT method was used to evaluate the inhibitory activity of the Erythrina variegata L. extract on proliferation of cancer cell lines. Moreover, in order to determine its anti-tumor effect in vivo, the Lewis lung cancer mice model was established. By comparing the relative tumor proliferation rates, growth curves, inhibition rates of different groups, the anti-tumor effect was evaluated. Furthermore, the anti-tumor mechanism of Erythrina variegata L. extract was studied by using G-quadruplex stability experiment. In the in vitro anti-liver cancer experiment, the Erythrina variegata L. extract has shown obvious anti-tumor effect on various tumor cells. And in the in vivo experiment, it exhibited significant anti-tumor effect. Besides, from the result of G-quadruplex stability experiment, we can see that the quadruplex structure show increasing T(m) values with increasing amounts of Erythrina variegata L. extract.
Animals
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Antineoplastic Agents, Phytogenic
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isolation & purification
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pharmacology
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Carcinoma, Lewis Lung
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pathology
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Cell Line, Tumor
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Cell Proliferation
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drug effects
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Drugs, Chinese Herbal
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isolation & purification
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pharmacology
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Erythrina
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chemistry
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G-Quadruplexes
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drug effects
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Humans
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Male
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Mice
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Mice, Inbred C57BL
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Plants, Medicinal
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chemistry
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Tumor Burden
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drug effects