Biomedical subjects

Qun Zhou

Publications and source records attributed to Qun Zhou.

At least 37 records · Page 2Linked to original sources

PubMed2005

[Quality analysis of powdered milk via FTIR spectroscopy].

Eleven kinds of powdered milk were identified by Fourier transform infrared spectroscopy (FTIR). The main nutritious components had distinct fingerprint characteristics in the IR spectra of milk powder. For samples from the same factory but of different brands, there was some dissimilarities in the relative intensities of infrared absorption peaks due to the difference in fat, protein and carbohydrate as well. For the samples of the same sort, but from different factories, there were certain similarities in the IR spectra. The spectra of milk powders with high level of fat, protein, and carbohydrates have their own characteristic absorption prak in the FTIR. Three kinds of commonly used excipients: maltodextrin, sucrose and lactose, all have specific fingerprint features, which change as their amounts alter. The present research provides a fast and direct method for evaluating the quality of powdered milk.

Animals↗

PubMed2004

N-linked oligosaccharide analysis of glycoprotein bands from isoelectric focusing gels.

Glycoproteins often display a complex isoelectric focusing profile because of the presence of negatively charged carbohydrates, such as sialic acid, phosphorylated mannose, and sulfated GalNAc. Until now, understanding the role of these charged carbohydrates in determining the isoelectric focusing profile has been limited to observing pattern shifts following complete removal of the sugars in question. We have developed a simple and sensitive method for analyzing N-linked oligosaccharides from the individual isoelectric focusing bands of a glycoprotein using recombinant human thyroid-stimulating hormone as a model system. N-linked oligosaccharides were released and profiled from individual bands following electroblotting of isoelectric focusing gels. As might be predicted, high-pH anion-exchange chromatography-pulsed amperometric detection and matrix-assisted laser desorption/ionization-time of flight analyses indicated that the bands that migrated closer to the positive electrode contained more sialylated N-linked oligosaccharides. The sialic acid content of these bands correlated with that predicted from the corresponding oligosaccharide analyses.

Chromatography, Ion Exchange↗

PubMed2004

Conjugation of mannose 6-phosphate-containing oligosaccharides to acid alpha-glucosidase improves the clearance of glycogen in pompe mice.

Clinical studies of enzyme replacement therapy for Pompe disease have indicated that relatively high doses of recombinant human acid alpha-glucosidase (rhGAA) may be required to reduce the abnormal glycogen storage in cardiac and skeletal muscles. This may be because of inefficient cation-independent mannose 6-phosphate receptor (CI-MPR)-mediated endocytosis of the enzyme by the affected target cells. To address this possibility, we examined whether the addition of a high affinity ligand to rhGAA would improve its delivery to these cells. Chemical conjugation of high mannose oligosaccharides harboring mono- and bisphosphorylated mannose 6-phosphates onto rhGAA (neo-rhGAA) significantly improved its uptake characteristics by muscle cells in vitro. Infusion of neo-rhGAA into Pompe mice also resulted in greater delivery of the enzyme to muscle tissues when compared with the unmodified enzyme. Importantly, this increase in enzyme levels was associated with significantly improved clearance of glycogen ( approximately 5-fold) from the affected tissues. These results suggest that CI-MPR-mediated endocytosis of rhGAA is an important pathway by which the enzyme is delivered to the affected lysosomes of Pompe muscle cells. Hence, the generation of rhGAA containing high affinity ligands for the CI-MPR represents a strategy by which the potency of rhGAA and therefore the clinical efficacy of enzyme replacement therapy for Pompe disease may be improved.

Animals↗

PubMed2004

The protein tyrosine phosphatase CD45 is required for interleukin 6 signaling in U266 myeloma cells.

The objective of this study was to examine whether CD45 mediates interleukin 6 (IL-6) signaling in human multiple myeloma (MM) cells. We chose U266 MM cells as a study model and isolated cells into CD45+ and CD45- subpopulations. CD45+ and CD45- U266 cells were cocultured with bone marrow stromal cells (BMSCs). IL-6-induced proliferation in CD45+ U266 cells was inhibited by vanadate, a potent protein tyrosine phosphatase inhibitor. However, IL-6-independent CD45- U266 cell growth was not affected by vanadate. CD45+ U266 cells, but not CD45- U266 cells, have the capability of cell adhesion concomitant with actin filament polymerization at the adherent cells. Adhesion of CD45+ U266 cells to BMSCs was impaired by vanadate. We clarified the signaling differences between CD45+ and CD45- U266 cells in response to IL-6. In CD45+ U266 cells, IL-6 increased tyrosine phosphorylation of gp130 and STAT3 and stimulated the level of Mcl-1 protein expression. An association between CD45 and the Src-family protein tyrosine kinase, Lyn, was maintained in the presence of IL-6; the formation of the CD45/Lyn complex was impaired by vanadate. Additionally, IL-6-induced Lyn kinase activity in CD45+ U266 cells was increased by the cross-linking of CD45, and this increase was due to the dephosphorylation of Tyr507 at Lyn. In conclusion, IL-6-dependent MM cells require CD45 to initiate IL-6 signaling and to maintain Lyn kinase activity, both of which are essential for cell proliferation and cell adhesion.

Actins↗

PubMed2004

[Analysis and assessment of Coptis chinensis for different parts, ages, and heights using Fourier transform infrared spectroscopy].

OBJECTIVE: To study the infrared (IR) fingerprint spectra of Coptis chinensis for different parts, ages, and heights, and to analyze the integrate rules about the content of berberine component in Coptis chinensis for different parts, ages, and heights. METHOD: The Fourier transform infrared (FTIR) spectroscopy was applied to detect the infrared spectra of Coptis chinensis samples rapidly and non-separately. RESULTS: The IR spectra of the root, leafstalk, and fibre of Coptis chinesis have their unique features. The content of berberine component in Coptis chinensis was different for different parts and the sequence: root > leafstalk > fibre. When Coptis chinensis grows, the content of berberine component in leafstalk also increases. The content of berberine component in leafstalk which planting in 1 200 m was less than that in 1 300, 1 400, and 1 500 m. The ages and heights provide no obvious influences on the content of berberine in the root of Coptis chinensis. CONCLUSION: Using FTIR spectroscopy, the quality of Coptis chinensis can be controlled, which provides a useful method for the standardized planting of Coptis chinensis.

Altitude↗

PubMed2004

[A rapid and nondestructive analysis of red wines of different manufacturers].

Alcohol and sugar are two main components in wine. We applied ATR Fourier Transform Infrared (FTIR) spectra and second derivative spectra to analyze the alcoholicity and content of sugar of red wines produced by different manufacturers for the first time. For wines with less sugar, the intensity of absorption peaks assigned to C-O bond at 1120-1000 cm(-1) becomes stronger when the alcoholicity is higher. For wines with more sugar, we can confirm the content of sugar by the intensity of absorption peaks and the number of peaks during the range from 1200 to 830 cm(-1), which includes many the characteristic absorptions of sugar. FTIR spectra not only can show clearly the relationship between the intensity of peaks and content of alcohol and sugar, but also are so rapid and convenient that it can be used to analyse samples directly.

Alcoholic Beverages↗

PubMed2004

[Study on the identification of standard and false BanXia by two-dimensional infrared correlation spectroscopy].

Standard BanXia (Pinellia temata (Thumb.) Breit) and false Shui BanXia (Typhonium flagelliforme (Lodd.) Blume) were identified fast and nondestructively by Fourier Transform Infrared Spectroscopy (FTIR) combined with two-dimensional correlation spectroscopy (2D) in this paper. The two kinds of BanXia wree similar to each other in one-dimensional IR spectra but quite different in 2D FTIR spectra. In the range between 1 220 cm(-1) and 1700 cm(-1), one strong autopeak was aroused by BanXia around 1410 cm(-1) in synchronous spectrum, whereas three autopeaks not only at 1460 cm(-1) but also at 1540 cm(-1) and 1680 cm(-1) aroused by Shui BanXia. Also in the range between 940 cm(-1) and 1220 cm(-1), three autopeaks were shown at 980, 1080 and 1150 cm(-1) in synchronous spectrum of BanXia, but only two autopeaks at 1080 and 1150 cm(-1) in synchronous spectrum of Shui BanXia. It is proved that the 2D FTIR could serve in distinguishing standard and false medicinal herbs due to its unique advantages such as enhanced resolution and increased identification ability. Therefore, the rapidity and accuracy of 2D FTIR spectroscopy make it a powerful and new approach to evaluating the medicinal herbs.

Binding Sites↗

PubMed2004

[Wavelet denoising and optimization of two-dimensional correlation IR spectroscopy].

Wavelet analysis and wavelet denoising was applied to analyse the data of two dimensional correlation IR spectroscopy of traditional Chinese medicine for the first time in this article. The results showed that, after denoising, the authors can decrease the interference to the synchronous spectra of two dimensional correlation IR spectroscopy effectively, and tone up the signal peaks and separate the peaks which overlap together before denoising. In this way, the authors can not only improve the spectral revolution, but also get more spectral informations.

English Abstract↗

PubMed2003

Discrimination of Fritillary according to geographical origin with Fourier transform infrared spectroscopy and two-dimensional correlation IR spectroscopy.

Fritillaria is a traditional Chinese herbal medicine for eliminating phlegm and relieving a cough with a long history in China and some other Asian countries. The objective of this study is to develop a nondestructive and accurate method to discriminate Fritillaria of different geographical origins, which is a troublesome work by existing analytical methods. We conducted a systematic study on five kinds of Fritillaria by Fourier transform infrared spectroscopy, second derivative infrared spectroscopy, and two-dimensional (2D) correlation infrared spectroscopy under thermal perturbation. Because Fritillaria consist of a large amount of starch, the conventional IR spectra of different Fritillaria only have very limited spectral feature differences. Based on these differences, we can separate different Fritillaria to a limited extent, but this method was deemed not very practical. The second derivative IR spectra of Fritillaria could enhance spectrum resolution, amplify the differences between the IR spectra of different Fritillaria, and provide some dissimilarity in their starch content, when compared with the spectrum of pure starch. Finally, we applied thermal perturbation to Fritillaria and analyzed the resulting spectra by the 2D correlation method to distinguish different Fritillaria easily and clearly. The distinction of very similar Fritillaria was possible because the spectral resolution was greatly enhanced by the 2D correlation spectroscopy. In addition, with the dynamic information of molecular structure provided by 2D correlation IR spectra, we studied the differences in the stability of active components of Fritillaria. The differences embodied mainly on the intensity ratio of the auto-peak at 985 cm(-1) and other auto-peaks. The 2D correlation IR spectroscopy (2D IR) of Fritillaria can be a new and powerful method to discriminate Fritillaria.

China↗

PubMed2003

Syntheses and opioid receptor binding affinities of 8-amino-2,6-methano-3-benzazocines.

8-Amino-2,6-methano-3-benzazocine derivatives have been made using Pd-catalyzed amination procedures, and their affinities for opioid receptors were assessed. The 8-amino group was hypothesized to be a replacement for the prototypic 8-OH substituent for 2,6-methano-3-benzazocines and related opiates. This OH group is generally required for binding yet is implicated in unfavorable pharmacokinetic characteristics such as low oral bioavailability and rapid clearance via O-glucuronidation. The core structures in which the 8-OH group was replaced were cyclazocine and its enantiomers, ethylketocyclazocine and its enantiomers, ketocyclazocine, and Mr2034. Many new analogues had high affinity for opioid receptors with several in the subnanomolar range. Highest affinity was seen in analogues with secondary 8-(hetero)arylamino appendages. Binding to opioid receptors was enantioselective with the (2R,6R,11R)-configuration preferred and high selectivity for mu and kappa over delta opioid receptors was observed within the series. Several derivatives were shown to have intrinsic opioid-receptor-mediated activity in [(35)S]GTPgammaS assays.

Animals↗

PubMed2003

2D-IR correlation analysis of deteriorative process of traditional Chinese medicine 'Qing Kai Ling' injection.

The traditional Chinese medicine 'Qing Kai Ling' injection after deterioration is distinguished from the original formulation using Fourier-transform infrared spectroscopy (FTIR) and two-dimensional correlation infrared spectroscopy (2D-IR). The IR spectra of the injections before and after deterioration are so similar, that it is very difficult to distinguish them by using the conventional approach. However, the higher spectral resolution and more structural information provided by 2D-IR analysis makes the identification possible. According to the results of 2D correlation analysis, the band at 1611 cm(-1) in IR spectra, in fact, consists of the overlap of three bands at 1572, 1667 and 1729 cm(-1), which are assigned to the alkaloids (heterocyclic compounds), flavone derivatives, and carbonyl compounds in the injection, respectively. Interestingly, the autopeak at 1667 cm(-1) disappears in synchronous spectrum of the deteriorated 'Qing Kai Ling' injection. It is suggested that the deterioration of the injection in air at room temperature be due to the oxidation of the flavone compounds mainly. As all intensities of the correlation peaks involved with the band in 1059 cm(-1) decrease greatly, it is assigned to the thermal decomposition of the glucoside components. Hence, it can conclude that the oxidation of the flavone compounds and the decomposition of the glucoside components are some of the main causes concerning to the deterioration of 'Qing Kai Ling' injection at ambient temperature. Thus, the 2D-correlation analysis provides a powerful method for the quality control of the traditional Chinese medicine injection.

Drug Stability↗

PubMed2003

[FTIR and classification study on gouqi from different cultural areas].

Gouqi, a commonly used traditional Chinese medicine, was studied by Fourier transform infrared (FTIR) spectroscopy in this paper. The combination of FTIR with mathematic method was used for the first time to classify the Gouqi from different cultural areas. It can be seen that the Gouqi samples from Ningxia Yuxi, Ningxia Zhongning and Neimenggu Tuoketuoqi could be successfully classified by soft independent modeling of class analogy (SIMCA). As having the fast and accurate characters, FTIR provides a new way to evaluate the origin of the Chinese medicines impersonally based on the traditional methods.

Geography↗

PubMed2003

[FTIR study on the hypertrophicscar and normal skin tissues].

40 cases of hypertrophicscar (HS) tissues and corresponding normal skin tissues were studied by FTIR technique, and the results showed that all of the HS and normal tissues can be classified into three kinds. Furthermore, the absorption bands of biomacromolecule in collagen, protein, nucleic acid and lipid of hypertrophicscar are stronger than those of normal tissues. But there is no significant difference in A1,063/A1,548 between HS and normal tissues. It is suggested that the cells of HS could still be normally growing and should not be scathed in the treatment process.

Cicatrix, Hypertrophic↗

PubMed2003

Synthesis and pharmacology of 8-amino-3-[(tetrahydro-2-furanyl)methyl] benzomorphan.

AIM: To design and synthesize new chiral 8-(substituted) amino-analogues of 3-[(tetrahydro-2-furanyl)methyl] benzomorphans, to expand knowledge of the structure-activity relationship (SAR) for 8-aminobenzomorphan. METHODS: Target compounds were synthesized from the 8-triflate of the optically active 3-[(tetrahydro-2-furanyl)methyl]-2,6-methano-benzomorphans using Pd-catalyzed aminations. Opioid receptor binding experiments were performed to evaluate their biological activities. RESULTS: Both 8-amino and 8-phenylamino analogues showed lower binding affinity for mu, delta and kappa receptors than corresponding 8-hydroxy-3-[(tetrahydro-2-furanyl)methyl]-2,6-methano-benzomorphan in vitro. CONCLUSION: The relative poor binding affinity of the target compounds did not warrant conducting the in vivo studies to determine if they have the profile(kappa agonist/mu antagonist) that will be potentially useful in the treatment of drug addiction. Further study is in progress.

Animals↗

PubMed2002

Mannose 6-phosphate quantitation in glycoproteins using high-pH anion-exchange chromatography with pulsed amperometric detection.

An assay has been developed to quantitate the amount of mannose 6-phosphate in glycoproteins using high-pH anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The method was tested on a recombinant lysosomal enzyme, human alpha-galactosidase A, that contains mannose 6-phosphate. The assay includes two steps: hydrolysis of the glycoprotein in 6.75 M trifluoroacetic acid to release mannose 6-phosphate and quantitation of the released mannose 6-phosphate using HPAEC with PAD. There is a linear relationship between the amount of mannose 6-phosphate measured and the amount of alpha-galactosidase hydrolyzed. The assay is also sensitive for as little as 2.5 microg alpha-galactosidase, which contains 117 pmol mannose 6-phosphate. Further, the assay has been shown to have good day-to-day and operator-to-operator consistency. In order to evaluate the assay for glycoprotein in crude extract, the glycoprotein was separated by SDS-PAGE and transferred to polyvinylidene difluoride membrane. The amount of mannose 6-phosphate in the electroblots following hydrolysis was determined using HPAEC-PAD. The assay was also linear when measuring mannose 6-phosphate on electroblots. Therefore, this assay has been shown to be specific, sensitive, and reproducible.

Blotting, Western↗

PubMed2002

Control of mammary tumor cell growth in vitro by novel cell differentiation and apoptosis agents.

The use of breast tumor differentiating agents to complement existing therapies has the potential to improve breast cancer treatment. Previously we showed quinidine caused MCF-7 cells to synchronously arrest in G1 phase of the cell cycle, transition into G0 and undergo progressive differentiation. After 72-96 h cells became visibly apoptotic. Using several analogs of quinidine we determined that MCF-7 cell cycle exit and differentiation are typical of quinoline antimalarial drugs bearing a tertiary amine side chain (chloroquine, quinine, quinidine). Differentiated cells accumulated lipid droplets and mammary fat globule membrane protein. Apoptosis was assayed by a nucleosome release ELISA. Quinidine and chloroquine triggered apoptosis, but not quinine, a quinidine stereoisomer that displayed weak DNA binding. The apoptotic response to quinidine and chloroquine was p53-dependent. A 4-15-fold induction of p21(WAF1) protein was observed in cells treated with quinidine or chloroquine prior to apoptosis, but p21(WAF1) was not increased in cells that differentiated in response to quinine. Chloroquine was most active in stimulating MCF-7 apoptosis, and quinine was most active in promoting MCF-7 cell differentiation. We conclude, distinct mechanisms are responsible for breast tumor cell differentiation and activation of apoptosis by quinoline antimalarials. Alkylamino-substituted quinoline ring compounds represented by quinidine, quinine, and chloroquine will be useful model compounds in the search for more active breast tumor differentiating agents.

Antineoplastic Agents↗

PubMed2002

[Recognition of three classes of skullcaps by FTIR spectroscopy combined with artificial neural networks].

In order to recognition of three classes of skullcaps (cultivated, wild Scutellaria baicalensis Georgi and Scutellaria viscidula Bge) three kinds of models of artificial neural networks (ANN), nonlinear-linear, linear-linear and nonlinear-nonlinear model, were used combined with their infrared spectra. Skullcaps samples were collected by Fourier Transform Infrared (FTIR) spectra. 42 samples were gathered as a train set, and 34 samples as a test set, then their supervision trains were performed using three models each. When the summation of error square of train target was selected as 0.01, the correct rate for recognition of three classes of skullcaps using each ANN was 100% for the train set, but was different for the test set, which depended on the number of node in hidden layer, S1. It was found that with the increase of S1, the correct rate would decrease oppositely. This may be caused by the high degree of the non-linearity of the networks, so that the models of networks were not fit for the train of this kind of sample set. When using linear-linear model of ANN varied with S1 in some extent, the correct rate was generally about 85%. Recognizability obtained using nonlinear-linear model of ANN was the best. Its correct rate of recognition was > 97% when S1 = 3, and so this method can be used to recognize three of skullcaps simply, rapidly, and accurately.

Apigenin↗

PubMed2002

[A rapid method for the identification of untreated Chinese herbs by FT-Raman spectrometry].

In this paper, two groups of Chinese herbs are investigated, one includes four species of rhubarb in which only one is used to treat against diseases and illnesses as Traditional Chinese Medicine, the other group is a common anemarrhena rhizome, it is found to mix with different materials in it. Both of them are directly identified by means of Fourier transform Raman spectroscopy for the first time. The tiny, delicate varied chemical components of different raw Chinese herbs lead to different characters in vibration frequency of Raman functional groups. It is found that the vibration frequency variance follows a certain specific regularity. The method is more precise and quick than traditional approaches. What is more, it will not damage samples.

Anemarrhena↗