Biomedical subjects

Jinghai Zhang

Publications and source records attributed to Jinghai Zhang.

9 recordsLinked to original sources

PubMed2006

Delivery of different length poly(L-lysine)-conjugated ODN to HepG2 cells using N-stearyllactobionamide-modified liposomes and their enhanced cellular biological effects.

Short (14-20-mer range) synthetic oligodeoxynucleotides (ODNs) allow specific modulation of cellular gene expression at various stages, thus providing a versatile tool for fundamental studies and a rational approach to anticancer chemotherapy. However, several problems, such as metabolic stability, efficient cell internalization of ODNs and their efficient entrapment into liposomes continue to markedly limit this approach. To improve the target specificity and biological activity of ODN, three different length of poly(L-lysine) (PLL) were conjugated to ODN and these conjugates were encapsulated in N-stearyllactobionamide (N-SLBA)-modified liposomes, N-SLBA is a ligand for the asialoglycoprotein receptor. Then, we investigated their effects on cell cycle and survivin protein levels of HepG2 cells. The results showed that the encapsulation efficiency was improved because the polycationic charges of PLL neutralized the polyanionic charges of ODN. Among them, PLL (M(W) 2000 and 10,000)-conjugated ODN encapsulated in N-SLBA liposomes induced apoptosis of HepG2 cells and highly inhibited survivin gene expression.

Apoptosis↗

PubMed2006

Construction, detection and microarray analysis on Shigella dysenteriae a1 IroN, ShuA single, double mutants.

In this study, we constructed single mutants MTS-1, MTS-2 of IroN and ShuA gene and double mutant MTS of them in Shigella dysenteriae A1 strain 51197 by insert and absence. The functional detection of every mutant was performed at the level of culture medium and cell experiment. The gene expression profiles of the mutants and the wild-type strains under iron-enriched and iron-limited conditions were analyzed by the SD51197 whole genomic microarray. The results showed that all the mutants grew obviously less well than the wild-type strains in L broth appending iron chelator DIP. The addition of iron to the cultures can stimulate the growth of mutants back to wild-type levels. In either the experiments on the ability of intracellular multiplication or the cell-to-cell spread in HeLa and U937 cell lines, mutants showed no obvious change in virulence compared with the parental strain SD51197. However when DIP was added to the cultured HeLa cells, the ability of intracellular multiplication of MTS-1, MTS-2, MTS has reduced about 23.4%, 25.2%, 43.6% respectively. The analysis of expression profiles under the iron-limited condition showed that the mutants were more sensitive for the changes of iron deficiency than the wild-type strains, many genes have been altered. Up-regulated genes mainly involved genes of transcription, coenzyme metabolism, amino acid transport and metabolism, and unknown functional genes, while down-regulated genes mainly involved genes of energy and carbohydrate metabolism and unknown function genes; the expression levels of known iron-transport associated genes generally showed up-regulated. The results demonstrated that iron-transport associated genes IroN, ShuA were likely to have some effects on the virulence and growth of S. dysenteriae.

Cell Line↗

PubMed2005

Functional grouping of yeast genes via biclustering microarray data.

Biclustering algorithm on Gibbs sampling strategy is a recruit in the field of the analysis of gene expression data of microarray experiments. Its feasibility and validity still need to be researched not only for synthetic datasets but also for real datasets. Here we investigated a biclustering algorithm on a microarray dataset of Yeast genome through building a database for storing microarray datasets and MIPS data, and running the scripts on Matlab platform to discover gene patterns. In contrast with standard clusterings that reveal genes behaving similarly over all the conditions, biclustering groups genes over only a subset of conditions for which those genes have a sharp probability distribution. It has the key advantage of providing a transparent probabilistic interpretation of the biclusters. Its basic strategy of Gibbs sampling does not suffer from the problem of local minima that often characterizes expectation maximization, so that the patterns should be more global and accurate. Also we tested it with the known explanation of genes in MIPS, objectively to demonstrate the effectiveness and deficiencies of biclustering approach, and the functions of a few unknown ORFs in some bicluster can be deduced in the present research. In addition, the result of similarity searching in Blast-Search can be an assistant evidence for its effectivity.

Cluster Analysis↗

PubMed2005

A new strategy of cooperativity of biclustering and hierarchical clustering: a case of analyzing yeast genomic microarray datasets.

Hierarchical clustering is difficult to be deployed effectively in finding meaningful subtrees since genes rarely exhibit similar expression pattern across a wide range of conditions. It is also difficult to find a suitable level in cleaving a big hierarchy tree. Biclustering is a promising methodology in the field of the analysis of gene expression data of genechip. Generally it can be employed in identification of gene groups, which show a coherent expression profile across a subset of conditions. But in some cases of biclustering analysis of gene expressions, the genes in one bicluster are involved in more than one functional group, or all genes in one bicluster are involved in unknown functional groups (e.g. pattern VI and VIII in our studies). Then, how to predict the function of genes in these patterns? In the present research, we developed a new strategy of combining both of the clustering methods, hierarchical clustering and biclustering. The reserved conditions in datasets for hierarchical clustering were elicited according to the conditions in biclusters, and after hierarchical clustering, more detailed results in predicting unknown genes in certain patterns were obtained. This strategy of cooperating both of the methods during clustering procedure should be an effective guideline for functional predictions.

Cluster Analysis↗

PubMed2005

Comparative genomics and phylogenetic analysis of S. dysenteriae subgroup.

Genomic compositions of representatives of thirteen S. dysenteriae serotypes were investigated by performing comparative genomic hybridization (CGH) with microarray containing the whole genomic ORFs (open reading frames, ORFs) of E. coli K12 strain MG1655 and specific ORFs of S. dysenteriae A1 strain Sd51197. The CGH results indicated the genomes of the serotypes contain 2654 conserved ORFs originating from E. coli. However, 219 intrinsic genes of E. coli including those prophage genes, molecular chaperones, synthesis of specific O antigen and so on were absent. Moreover, some specific genes such as type II secretion system associated components, iron transport related genes and some others as well were acquired through horizontal transfer. According to phylogenic trees based on genetic composition, it was demonstrated that A1, A2, A8, A10 were distinct from the other S. dysenteriae serotypes. Our results in this report may provide new insights into the physiological process, pathogenicity and evolution of S. dysenteriae.

Genes, Bacterial↗

PubMed2004

Bioavailability and anticataract effects of a topical ocular drug delivery system containing disulfiram and hydroxypropyl-beta-cyclodextrin on selenite-treated rats.

PURPOSE: To test the effect of aqueous eye drops containing a high concentration of disulfiram (DSF) in a cyclodextrin- based drug delivery system. This system increases both the drug solubility in aqueous eye drops and the permeability of drug into the rabbit eye, by the formation of a drug-cyclodextrin inclusion complex, and so enhances the ocular bioavailability and anti-cataract effect of DSF. METHODS: The DSF and hydroxypropyl-beta-cyclodextrin (HPbetaCD) inclusion (DSF/HPbetaCD) was studied using solubility methods, IR spectra and X-ray diffraction patterns. Suitable formulations for DSF eye drops were first identified by a trans-corneal penetration experiment in vitro. Finding a new p-bromophenacyl bromide (p-BPB) derivative reagent for diethyldithiocarbamic acid (DDC), which was a metabolite of DSF, allowed precise determination of the contents of DSF in aqueous humor. The ocular bioavailability was calculated by a transcorneal experiment of DSF in vivo. The lens opacity of a selenite-induced cataract in rat pups was monitored using a slit lamp with an anterior eye segment analysis system. RESULTS: The formation of DSF/HPbetaCD inclusion and the addition of hydroxypropylmethylcellulose (HPMC), as a penetration enhancer, played very important roles in increasing the ocular bioavailability of DSF. DSF eye drops, with a formulation of 1.26% (w/v) DSF/HPbetaCD inclusion, 0.01% (w/v) HPMC, 0.005% (w/v) benzalkonium chloride and 0.9% (w/v) sodium chloride, inhibited the onset of selenite-induced cataracts effectively. CONCLUSIONS: The cyclodextrin-based drug delivery system enhances both the solubility of DSF in aqueous eye drops and permeability of the drug into the rabbit eye. DSF ocular bioavailability in rabbit aqueous humor exceeded those reported for the DSF ophthalmic preparation. DSF eye drops effectively prevent the development of selenite-induced cataracts.

2-Hydroxypropyl-beta-cyclodextrin↗

PubMed2004

An ocular drug delivery system containing zinc diethyldithiocarbamate and HPbetaCD inclusion complex--corneal permeability, anti-cataract effects and mechanism studies.

Our purpose was to study the formulation and anti-cataract effects of aqueous eye drops containing a high concentration of zinc diethyldithiocarbamate (Zn-DDC). A possible mechanism of the anti-cataract effect of Zn-DDC was also studied. Zn-DDC and hydroxypropyl-beta-cyclodextrin (HPbetaCD) inclusion complex (Zn-DDC/HPbetaCD) was studied using the saturation solution method and characterized by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (IR). Suitable formulations for Zn-DDC eye drops were established by means of in-vitro trans-corneal penetration experiments. The anti-cataract effect of the selected formulation was demonstrated by the delay in lens opacity development in hereditary shumuya cataract rats (SCRs). Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) was performed to study the effect of diethyldithiocarbamate (DDC), a metabolite of Zn-DDC, on the transcription inducible nitric oxide synthase (iNOS) mRNA in human lens epithelial cells (HLEC). In the presence of 22% (w/v) HPbetaCD, the solubility of Zn-DDC in water (0.2 mM) was increased almost 850 fold (to 17 mM), by the formation of Zn-DDC/HPbetaCD. The stoichiometry of Zn-DDC inclusion was 1:1. The Zn-DDC/HPbetaCD stability constant, Ks (1:1) was estimated to be 3453 M(-1). The ophthalmic preparation containing 0.1% HPMC and 0.1% poloxamer 188 (P188) exhibited better permeability than the others in-vitro, and significantly delayed cataract formation in SCRs compared with non-treated SCRs. DDC inhibits the transcription of iNOS mRNA in HLEC. We concluded that this drug delivery system increases both the drug solubility in aqueous eye drops and the permeability of drug through the rabbit cornea, by the formation of a drug-cyclodextrin inclusion complex and the addition of polymers and penetration enhancers. The preparation effectively prevented the development of cataracts in SCRs. DDC, the metabolite of Zn-DDC, may be one of the factors in the prevention of cataract formation because it inhibits the transcription of iNOS mRNA.

2-Hydroxypropyl-beta-cyclodextrin↗

PubMed2003

White spot syndrome virus (WSSV) infectivity for Artemia at different developmental stages.

White spot syndrome virus (WSSV) is a major pathogen of cultivated shrimp, but its host range includes a large number of crustaceans. In this investigation, Artemia franciscana was tested for susceptibility to WSSV by the oral route. Both instars and adults were challenged, and the presence of WSSV was followed through to reproductive cysts and offspring using PCR. WSSV caused a much lower cumulative mortality in Artemia than in cultivated shrimp by 10 d post-challenge. Instars, adults and reproductive cysts were PCR positive. However, the virus was undetectable by PCR in nauplii that had hatched from PCR-positive reproductive cysts. The data indicate that WSSV or WSSV genomic DNA can be vertically transmitted from WSSV-PCR-positive instars to reproductive cysts, but this DNA is removed during hatching.

Animals↗

PubMed2003

Proteomic analysis of proteins that binds specifically to the homologous repeat regions of white spot syndrome virus.

White spot syndrome virus (WSSV) is a major pathogen in the cultivated shrimp. Nine homologous repeat regions (hrrs) have been reported interspersed throughout the WSSV genome. In this investigation, the protein fraction that specifically bound to the hrrs was isolated by using DNA-affinity chromatography. A total of 9 (S1 to S9) and 5 (C1 to C5) proteins separated from the WSSV infected shrimp and the healthy shrimp, respectively, were detected by using two-dimensional polyacrylamide gel electrophoresis, and 6 proteins changed with WSSV infection were analyzed by mass spectrometry (MS). One (S4) of the 6 proteins examined was identified as WSSV ORF59 protein, and another (S3) was a shrimp arginine kinase. No homologous proteins were found with the remaining 4 proteins by searching in the WSSV ORF database and NCBI database. The specific binding site of the 6 proteins was then determined by gel mobility shift assay (GMSA). Temporal analysis revealed that ORF59 gene was transcribed at the early stage of the infection. The results we obtained provide important information to understand WSSV replication. The combination of DNA-affinity chromatography, 2D-PAGE and MS approaches should have general application to the identification of gene regulating proteins of WSSV. The results represent the first isolation of a set of proteins that bind to the hrrs, and, furthermore, lead us a new research direction for the prevention and the therapy of WSSV.

Animals↗