Search Results

You are looking at 1 - 10 of 12 items for

  • Author or Editor: Jiang Wu x
Clear All Modify Search

The increasing threat of drug-resistant strains of Mycobacterium tuberculosis (M. tb) and co-infection with human immunodeficiency virus (HIV) has worsened the international public health crisis and challenged conventional chemotherapy. Therapeutic vaccines, which possess the capacity to stimulate the immune system and affect the disease progression, deserve reconsideration to aid chemotherapy. Vaccines based on Ag85B-ESAT6 fusion protein were tested as potential immunotherapeutic vaccines against ongoing intravenous infection in a mouse model. Therapeutic efficacy was evaluated by enumeration of bacilli in infected tissues and by histological examination of the lungs. Ag85B-ESAT6 with the adjuvant dimethyl dioctadecylammonium bromide (DDA) — monophosphoryl lipid A (MPL) did not reduce bacterial load, however induced a sharp weight loss and worsened pathology. Recombinant virus-based vaccines failed to protect mice against tuberculosis either. More efforts should be taken to search for protective candidates and elucidate the mechanism for immunotherapy.

Full access
Authors: Fahar Ibtisham, Yi Zhao, Jiang Wu, Aamir Nawab, Xiao Mei, GuangHui Li and Lilong An

Introduction

The ability for isolation and in vitro propagation of spermatogonial stem cells (SSCs) offer a base for studies on spermatogenesis, and also contribute to the development of new methods for the preservation of livestock and animal genetic modification. The aim of this study was to find the optimal isolation and culture condition for efficient propagation of SSCs.

Methods

Three different isolation methods (mechanical, one-, and two-step enzymatic digestion) were compared to find the optimal isolation method. To find the best culture conditions for in vitro propagation, isolated SSCs were cultured for 7 days in three different culture conditions supplemented with 10% FBS, 0.25% BSA, and 10% KSR, respectively.

Results

The result showed that two-step enzymatic digestion produced a significant high fraction of live cells compared the other two. Non-adhering cells collected after 48 hr and cultured in BSA- and KSR-supplemented medium had a significantly high number of SSCs clump formation compared to FBS-supplemented group. The expression of CD9 confirmed that cell clumps were SSCs clumps. Spermatogonial stem cells cultured in BSA-supplemented medium were positive for NGN3 and PLZF expressions, whereas negative for Stra8 (a meiotic-specific gene) expression, suggesting that most of the cells were undifferentiated SSCs in BSA culture system. In contrast, in FBS- and KSR-supplemented groups, the SSCs were positive for NGN3, PLZF, and Stra8.

Conclusion

These data revealed that two-step enzymatic digestion is the best method for the isolation, and 0.25% BSA-supplemented culture condition is effective for optimal in vitro propagation of SSCs.

Full access

Atractylodis exerted a variety of pharmacological effects such as anti-tumor, anti-inflammatory, anti-bacterial, and anti-aging effects etc. The major ingredients of Atractylodis are atractylenolide I and II that exhibited activities in anti-inflammatory and anticancer. In this work, a sensitive and selective ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for determination of atractylenolide I and II in rat plasma was developed. The UPLC–MS/MS method was validated for selectivity, linearity, accuracy, precision, recovery, and stability with a total run time of 4.0 min. After addition of atractylenolide III as an internal standard (IS), protein precipitation by acetonitrile was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 231.1 → 185.1 for atractylenolide I, m/z 233.1 → 91.0 for II, and m/z 249.0 → 231.1 for IS. Calibration plots were linear throughout the range 1–1000 ng/mL for atractylenolide I and II in rat plasma. Mean recoveries of atractylenolide I and II in rat plasma ranged from 86.2% to 96.3%. Relative standard deviation (RSD) of intra-day and inter-day precision was both less than 12%. The accuracy of the method was between 91.0% and 109.0%. The method was successfully applied to pharmacokinetic study of atractylenolide I and II after intravenous administration in rats.

Open access
Authors: X. He, L. Wang, W. Pu, J. Ren, W. Wu, C. Jiang and C. Wan

Abstract  

Thermal analysis of sulfurization of polyacrylonitrile (PAN) with elemental sulfur was investigated by thermogravimetry and differential thermal analysis of the mixture of polyacrylonitrile and elemental sulfur up to 600°C. Due to the volatilization of sulfur, the different heating rate (10 and 20 K min−1) and different mixture proportion of polyacrylonitrile and elemental sulfur were adopted to run the analysis. The different heating rates make the DSC curves of sulfur different, but make the DSC curves of PAN similar. In the DSC curve of sulfur for the heating rate of 20 K min−1 around 400°C, a small exothermic peak occurs at 400°C in the wide endothermic peak around 380∼420°C, indicative of that there is an exothermic reaction around 400°C. In the DSC curves of the mixture, the peaks around 320°C are exothermic as the content of sulfur is below 3.5:1 and endothermic as the content of sulfur is over 4:1, indicating that one of the reactions between PAN and sulfur takes place around 320°C. In the TG curves of the mixture, the mass losses begin at 220°C, and sharply drop down from 280°C. The curves for the low sulfur content obviously show two steps of mass loss, and curves for the high sulfur content show only one step of mass loss, indicative of more sulfur is benefit for the complete sulfurization of PAN. This study demonstrates that the TG/DSC analysis can give the parameter for the sulfurization, even if the starting mixture contains the volatile sulfur.

Full access

Summary

The method of high-performance liquid chromatography (HPLC) with diode array detector (DAD) was used and validated for the simultaneous determination of nine flavonoids (rutin, myricetin, quercitrin, quercetin, luteolin, genistein, kaempferol, apigenin, and isorhamnetin) in beagle dog plasma. Plasma sample was pre-treated with acetonitrile (containing 0.05% formic acid). Chromatographic separation was performed on a kromasil C18 column (250 × 4.6 mm, 5 µm) maintained at 35 °C. The mobile phase was a mixture of methanol and 0.2% formic acid with a step linear gradient. At 1.0 mL min−1 flow rate, the eluent of other eight flavonoids was detected simultaneously at 360 nm with good separation except genistein (detected at 254 nm). Under optimum conditions, the correlation coefficient between the peak area and the concentrations for each analyte was all above 0.999. The intra-day and inter-day precisions were less than 10% for all analytes. The limit of detection and the limit of quantification for the selected nine flavonoids were 0.006–0.03 and 0.02–0.12 g mL−1, respectively. The extracted recoveries of selected nine flavonoids were 74.02%–99.37%. The assay has been successfully applied to determine concentrations of nine flavonoids in plasma from beagle dog after being intravenously administrated Ginkgo biloba extract.

Full access

Psoralidin has a variety of pharmacological activities, such as anti-tumor, anti-depressant, and anti-inflammatory activities. This study aims at developing a rapid ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method to determine psoralidin in rat plasma and studying the pharmacokinetic characteristic of psoralidin after intragastric administration of 20 and 40 mg/kg. Alpinetin was used as an internal standard (IS), and the plasma samples were precipitated with acetonitrile. The calibration curves were linear over the range of 0.2–250 ng/mL (R 2 = 0.993). The pharmacokinetic parameters were calculated by DAS 3.0. Half-life (t 1/2) was 7.2 ± 0.97 h and 7.1 ± 0.27 h for different dosages, respectively. T max was 4.2 ± 1.1 h and 4.0 ± 1.1 h for different dosages, respectively. Apparent volume of distribution (V d) for different dosages was 630.1 ± 168.8 and 600.1 ± 138.8 L/kg, respectively. Clearance (CL) was 105.6 ± 29.2 and 100.6 ± 22.2 L/h/kg for different dosages, indicating that psoralidin was mainly distributed in rat tissues. The pharmacokinetic study provided important information for further clinical application in the treatment of cancer and osteoporosis.

Open access
Authors: Jianbo Li, Yujie Hu, Yajin Wu, Tiantian Feng, Congcong Wen and Xiajuan Jiang

Abstract

Palmatine is a compound with good water solubility extracted from Coptis chinensis, Fibraurea recisa Pierre, Cortex Phellodendri Chinensis. Palmatine has good antibacterial activity and mainly used for the treatment of bacterial dysentery, gynecological inflammation, surgical infection, and conjunctivitis. It has anti-diabetic, anti-oxidant, and cognitive-enhancing activities. In this study, we used UPLC-MS/MS to determinate palmatine in rat plasma, and investigated its pharmacokinetics. Coptisine was utilized as an internal standard (IS), and acetonitrile precipitation method was used to process the plasma samples. Chromatographic separation was achieved using a UPLC BEH C18 column using mobile phase of acetonitrile- 0.1% formic acid with gradient elution. Electrospray ionization (ESI) tandem mass spectrometry in multiple reaction monitoring (MRM) mode with positive ionization was applied. The results indicated that within the range of 1–500 ng/mL, linearity of palmatine in rat plasma was acceptable (r > 0.995), and the lower limit of quantification (LLOQ) was 1 ng/mL. Intra-day and inter-day precision RSD of palmatine in rat plasma were less than 14%. Accuracy range was between 93.7 and 107.1%, and matrix effect was between 101.6 and 109.4%. The method was successfully applied in the pharmacokinetics of palmatine in rats after oral and intravenous administration. The absolute bioavailability of the palmatine was 15.5% in rats.

Open access

In the era of knowledge economy, a country’s economic competitiveness depends largely on the development level of high-tech industry. This paper evaluates the efficiency of China’s high-tech industry in 31 provinces in 2012 with data envelopment analysis. The empirical results are summarized as following. Firstly, when the effects of exogenous environmental variables are not controlled, the comprehensive technical efficiency of 31 provinces will be overestimated, the pure technical efficiency will be underestimated, and the scale efficiency value will be overestimated. Secondly, after eliminating the environmental impact, the comprehensive technical efficiency of 31 provinces with the average of 0.395 is rather low, due to the low scale efficiency.

Full access
Authors: Yang Ya-xin, Wu Xin-min, Lin Jun, Liu Qing-chen, Den Ju-zhi, Huang Hong-bo, Jiang Zhong-ying and Hsia Yuan-fu

Abstract  

Soil thermolumicenscence (TL), one of the methods for uranium exploration, is based on the glowing characteristics of the crystal minerals such as quartz in the nature. The paper deals with the experiments at Xiazhuang uranium ore-field, in order to show the availability of the thermoluminescence to explore granite-hosted uranium mineralization. Meanwhile, some constraints for application are discussed.

Full access
Authors: Li-Fang Song, Chun-Hong Jiang, Jian Zhang, Li-Xian Sun, Fen Xu, Yun-Qi Tian, Wan-Sheng You, Zhong Cao, Ling Zhang and Dao-Wu Yang

Abstract  

A novel two-dimensional metal organic framework MgBTC [MgBTC(OCN)2·2H2O, where BTC = 1,3,5-benzenetricarboxylate] has been synthesized solvothermally and characterized by single crystal XRD, powder XRD, FT-IR spectra. The low-temperature molar heat capacities of MgBTC were measured by temperature modulated differential scanning calorimetry (TMDSC) over the temperature range from 190 to 350 K for the first time. No phase transition or thermal anomaly was observed in the experimental temperature range. The thermodynamic parameters of MgBTC such as entropy and enthalpy relative to reference temperature of 298.15 K were derived based on the above molar heat capacities data. Moreover, the thermal stability and decomposition of MgBTC was further investigated through thermogravimetry (TG)-mass spectrometer (MS). Four stages of mass loss were observed in the TG curve. TG-MS curve indicated that the products of oxidative degradation of MgBTC are H2O, N2, CO2 and CO. The powder XRD showed that the mixture after TG contains MgO and graphite.

Full access