Biomedical subjects

Hui Wang

Publications and source records attributed to Hui Wang.

388 records · Page 22Linked to original sources

PubMed2002

[Relativities between lattice changes and the function of dissolution improvement of poorly soluble drug silymarin based upon PEG 6,000 solid dispersion system].

AIM: To investigate the lattice mechanisms involved in the increased dissolution effect of polyethylene glycol (PEG 6,000) dispersion system on poorly soluble drug silymarin (SILY). METHODS: Fusion method was used to prepare the solid dispersions of SILY with PEG 6,000. Evaluation of the improvement of dissolution was performed with dissolution studies in vitro. X-ray powder diffraction combined with diffraction peak pattern-fitting procedure were applied to quantitatively analyze the changes of lattice parameters. The interaction of SILY and PEG 6,000 was also determined with Fourier transform-infrared (FT-IR) spectroscopy. RESULTS: The dissolution rate of SILY was considerably increased when formulated in solid dispersion of PEG 6,000 as compared to pure SILY. The datum from the X-ray diffraction showed the changes in the lattic spacings and particular diffraction peaks (position and the intensity) of PEG 6,000 and SILY. These could explain the increased rate of SILY released from solid dispersion system. The information of FT-IR spectroscopy showed the absence of well-defined drug-polymer interaction. CONCLUSION: The dissolution improvement of poorly soluble SILY from solid dispersion of PEG 6,000 can be illuminated by the changes of the lattice parameters of PEG 6,000 and the drug.

Chemistry, Pharmaceutical↗

PubMed2002

[The detection of DNA adduct in human peripheral lymphocytes by bioluminescence method].

OBJECTIVE: To develop bioluminescence method to measure DNA adducts in human peripheral lymphocytes and study the factors that affect the level of DNA adduct, in order to use it in studying the relationship between water pollution and human DNA adduct levels. METHOD: The measurement of DNA adduct in peripheral lymphocytes was carried out in 234 normal persons, and the relationship between DNA adducts levels and age, smoking and eating habit etc. was analyzed. RESULTS: (1) The level of DNA adduct in males was higher than that in females, but without significance (P > 0.05); (2) The level of DNA adduct was significantly correlated with age, smoking, tea drinking, eating habit and alcohol drinking. Among them, age plus smoking were the most important factors affected the DNA adduct levels (P < 0.01). The level of DNA adduct increased with age. The more cigarette smoked, the higher was the level of DNA adduct. CONCLUSION: The level of DNA adduct is affected by many factors, so it needs further research to apply it in the biomonitoring and risk assessment of environment chemicals.

Adult↗

PubMed2002

[A new study progress of molecular genetics in autosomal dominant retinitis pigmentosa].

Retinitis pigmentosa (RP) describes a genetically and clinically heterogeneous group of disorders that are characterized by gradual degeneration of photoreceptor cells. Common clinical features include a progressive loss of night vision,leading to night blindness and peripheral-visual-field loss. At least 12 loci have been mapped to chromosomes, and mutations in an ever increasing number of genes have been found to cause autosomal dominant retinitis pigmentosa (ADRP). Six of the 12 genes known to cause ADRP have been cloned. New progress has been made on the studies of structure, mutation and function of these genes.

English Abstract↗

PubMed2001

Differentially Expressed Gene Profiles of hCR2-transfected Mouse Cells before and after EBV Infection and TPA Treatment.

Mouse Atlas(TM) cDNA Expression Arrays were used to analyze cellular gene expression profiles of human complement receptor type II gene (hCR2)-transfected mouse cells before and after EBV infection and TPA treatment, followed by screening differentially expressed genes with Eagle Eye II Image Analysis System. Results indicated that differentially expressed gene prifiles of EBV and TPA treated, hCR2-transfected mouse cells was preliminarily established. This study laid the basis for further research in relerant fields.

Journal Article↗

PubMed1997

The Isolation and Purification of Archaerhodopsin from Halobacterium sp. XZ515.

The claret membrane, instead of the purple membrane, was isolated when the conventional method for isolating purple membrane from Halobacterium halobium was applied to Halobacterium sp. XZ515. The SDS-PAGE results showed that only one protein, archaerhodopsin, existed in claret membrane with M. W. similar to BR. The method for isolating and purifying the archaerhodopsin, an intrinsic membrane protein, by detergent dissolution and hydrophobic chromatography on the column of octylsepharose, was also introduced. The pure archaerhodopsin showed the absorption spectrum similar to BR and was able to produce the M412 photoproduct in the photocycle under illumilation. It was concluded that this archaerhodopsin was a BR-like retinal protein.

Journal Article↗

PubMedDate not supplied

Expression of a novel RAD23B mRNA splice variant in the human testis.

A gene coding a novel human RAD23B protein named RAD23-like protein B, presumably involved in spermatogenesis, was identified and characterized using a complementary DNA (cDNA) microarray. In the human testis, its expression was 2.33 times higher than it was in the embryo testis, with a particularly high expression in ejaculated human spermatozoa. The full length of this gene is 1548 bp, and the putative protein is 338 amino acids long. This protein is homologous to RAD23B, which is one of two human homologs of Saccharomyces cerevisiae RAD23, and is involved in both nucleotide excision repair (NER) and ubiquitin (Ub)-dependent proteolysis. However, RAD23-like protein B lacks the Ub-like (UbL) domain that functions as a proteasome localization signal. Multiple-tissue expression profile of the messenger RNA (mRNA) that encodes the RAD23-like protein B also showed that it is highly expressed in the human testis and in ejaculated spermatozoa. Our present study indicates that this novel alternative splicing form of RAD23B is correlated with human spermatogenesis.

Amino Acid Sequence↗

PubMedDate not supplied

Structure-based rational quest for potential novel inhibitors of human HMG-CoA reductase by combining CoMFA 3D QSAR modeling and virtual screening.

3-Hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) catalyzes the formation of mevalonate. In many classes of organisms, this is the committed step leading to the synthesis of essential compounds, such as cholesterol. However, a high level of cholesterol is an important risk factor for coronary heart disease, for which an effective clinical treatment is to block HMGR using inhibitors like statins. Recently the structures of catalytic portion of human HMGR complexed with six different statins have been determined by a delicate crystallography study (Istvan and Deisenhofer Science 2001, 292, 1160-1164), which established a solid basis of structure and mechanism for the rational design, optimization, and development of even better HMGR inhibitors. In this study, three-dimensional quantitative structure-activity relationship (3D QSAR) with comparative molecular field analysis (CoMFA) was performed on a training set of up to 35 statins and statin-like compounds. Predictive models were established by using two different ways: (1) Models-fit, obtained by SYBYL conventional fit-atom molecular alignment rule, has cross-validated coefficients (q2) up to 0.652 and regression coefficients (r2) up to 0.977. (2) Models-dock, obtained by FlexE by docking compounds into the HMGR active site, has cross-validated coefficients (q2) up to 0.731 and regression coefficients (r2) up to 0.947. These models were further validated by an external testing set of 12 statins and statin-like compounds. Integrated with CoMFA 3D QSAR predictive models, molecular surface property (electrostatic and steric) mapping and structure-based (both ligand and receptor) virtual screening have been employed to explore potential novel hits for the HMGR inhibitors. A representative set of eight new compounds of non-statin-like structures but with high pIC(50) values were sorted out in the present study.

Binding Sites↗

PubMedDate not supplied

Global human genetics of HIV-1 infection and China.

Genetic polymorphisms in human genes can influence the risk for HIV-1 infection and disease progression, although the reported effects of these alleles have been inconsistent. This review highlights the recent discoveries on global and Chinese genetic polymorphisms and their association with HIV-1 transmission and disease progression.

China↗

PubMedDate not supplied

Cloning and characterization of a novel transcript variant of IQGAP2 in human testis.

Using cDNA microarray hybridization from a human testicular cDNA library, one gene exhibiting 6.4-fold difference at expression level between adult and embryo human testes was cloned and named tsIQGAP2 (testis specific IQ motif containing GTPase-activating protein 2). The full cDNA length of tsIQGAP2 is 3388 bp and contains a 3215 bp open reading frame, encoding a 122.85 kDa protein of 1071 amino acids. Sequence analysis showed that tsIQGAP2 harbors all the domains (one WW domain, three IQ motifs, and one RasGAP homology domain) in HsIQGAP2 (IQ motif containing GTPase-activating protein 2) except for the N-terminal calponin homology domain. Blasting human genome database localized tsIQGAP2 to human chromosome 5q13-14 and further investigation showed that it is a novel transcript variant of HsIQGAP2. The tissue distribution of tsIQGAP2 showed that it is a testis specific gene. The above results suggest the potential role of tsIQGAP2 during spermatogenesis and the mechanism by which tsIQGAP2 regulating spermatogenesis also has been proposed.

Alternative Splicing↗

PubMedDate not supplied

Antisense anti-MDM2 oligonucleotides as a novel approach to the treatment of glioblastoma multiforme.

Overexpression of the MDM2 oncogene is one of the molecular characteristics of gliomas. In this study we determined the therapeutic effects of an antisense anti-MDM2 oligonucleotide administered alone or in combination with the clinically used chemotherapeutic agents Paclitaxel and Irinotecan. In cultured cells with various p53 status, U87-MG (p53wt/wt), A172 (p53wt/mt) and T98G (p53mt/mt), the antisense oligonucleotide, produced a dose- and sequence-dependent reduction in MDM2 expression and elevation in p53 (in U87-MG and A172 cells) and p21 levels (in all three cell lines), resulting in an increase in apoptosis and cytotoxicity. Synergistic effects on p53 and p21 levels between the oligonucleotide and chemotherapeutic agents were also observed in vitro. In in vivo studies with U87-MG xenografts, the oligonucleotide inhibited tumor growth and improved the therapeutic efficacy of paclitaxel and irinotecan 39- and 63-fold, respectively. In conclusion, inhibiting MDM2 expression could be a novel pharmacological approach to glioblastoma therapy.

Animals↗