Biomedical subjects

Rong Zhao

Publications and source records attributed to Rong Zhao.

27 records · Page 2Linked to original sources

PubMed2004

[To repair perforation of nasal septum with free mucosa of inferior turbinate].

OBJECTIVE: To study a new treatment to repair perforation of nasal septum with free mucosa of inferior turbinate between two sides of mucosa of nasal septum. METHOD: The mucosa around perforation of nasal septum was separated by means of submucous correction of nasal septum, and some mucosa of inferior turbinate was cut down, then the mucosa bag of nasal septum and the free mucosa of inferior turbinate were sutured and the perforation could be covered completely. RESULT: The perforations of nasal septums in 21 patients were closed satisfactorily. Perforation of nasal septum did not recur and the follow-up time ranged from 3 months to half a year. CONCLUSION: The free mucosa of inferior turbinate is easy to be got and survive. What's more, it can be used to repair a big perforation of nasal septum. Our method is easy to be performed and the free mucosa can be fixed tightly.

Adolescent↗

PubMed2003

Molecular profiling of the immune response in colon cancer using protein microarrays: occurrence of autoantibodies to ubiquitin C-terminal hydrolase L3.

We implemented a protein microarray approach to identify proteins that induce a humoral response in colon cancer. Solubilized proteins from the LoVo colon adenocarcinoma cell line were separated into 1760 fractions, arrayed onto nitrocellulose-coated slides, and hybridized with individual sera from 15 newly diagnosed patients with colon cancer, 15 with lung cancer, and 15 healthy subjects. 39/1760 fractions showed enhanced reactivity with sera from patients with colon cancer (p < 0.01) relative to healthy controls. A distinct pattern of reactivity was observed with sera from colon cancer relative to lung cancer. One fraction that exhibited reactivity with 9/15 colon cancer sera was subjected to mass spectrometry leading to the identification of ubiquitin C-terminal hydrolase isozyme 3 (UCH-L3) as a constituent. To validate the occurrence of autoantibodies to UCH-L3, independent analysis was done by means of Western blots. UCH-L3 antibodies were detected in 19/43 sera from patients with colon cancer, and in 0/54 sera from subjects with lung cancer (24), colon adenoma (15) or otherwise healthy (15). Our findings indicate the occurrence of an immune response to a broad set of antigens in colon cancer and the feasibility of identifying the antigenic targets using a combination of protein microarrays and mass spectrometry.

Autoantibodies↗

PubMed2003

[Improvement of the silver-stain and it's test and verification in comet assay].

In order to find out a better silver-stain method so that to replace EB-stain in comet assay, the selected silver-stain methods were tested via determining fixing, coloring, displaying, fading, and testing the pigmentation temperature. When it was optimized, it was used in testing the DNA damage by two types of compounds, namely potassium dichromate (K2Cr2O7) and 1,2-dichloroethane (DCE) to two kind of cells, namely spleen cells of mouse and human outer lymphocyte, and, the sensitivity was compared with that of EB-stain. The results showed that the modified silver-stain was the first successful non-fluorescent dye method in comet assay that can dye clearly, permanently, with a light background and good contrast, and it was easy to manipulate and it was cheap. The stain can detect the DNA damage by compounds to cells and has the same positive threshold like that in EB-stain. It can even dye the small fragments that EB-stain cannot. It is suggested that in comet assay, the silver-stain can substitute the EB-stain completely.

Comet Assay↗

PubMed2003

[Copper sorption and desorption by loess in water-sediment systems].

A series of experiments were designed to investigate copper sorption and desorption by loess in hyper-concentrated sediment systems. The results demonstrate that loess had large copper sorption capacity because of its specific adsorption and precipitation of carbonate and hydroxide. Copper sorption decreased with increasing ionic strength of solution, but the effects of varying cationic charge of supporting electrolyte were still detected. Less than 4% of copper was desorbed in the neutral saline solution, and increased with increasing ionic strength of solution. The pH was the most dominant factor on copper desorption. More than 70% of copper can be desorbed in the acid solution, and copper desorption increased with the decrease of solution pH. When pH of solid-liquid system was fixed, copper desorption from equivalent loess increased with the increase of solution volume, and copper desorption in the same sediment concentration increased with the adsorptive capacity.

Adsorption↗

PubMed2003

[Association of single nucleotide polymorphism in human SCN7A gene with essential hypertension in Chinese].

OBJECTIVE: To identify the single nucleotide polymorphisms (SNPs) in the regulatory and coding regions of human SCN7A (sodium channel, voltage-gated, type VII, alpha polypeptide) gene and to investigate the association of some of these SNPs with essential hypertension (EH) in Chinese. METHODS: The promoter region, exons, as well as part of the introns of SCN7A gene were sequenced by a fluorescent labeling automatic sequencing method to identify and characterize the SNPs in Chinese population. SNP genotyping was performed by PCR-RFLP or direct DNA sequencing in unrelated EH patients and normotensive controls from a Chinese Han population residing in Shanghai area. Case-control studies on seven SNPs were first carried out in 96 patients and 96 normotensive controls. The positive finding was further verified in an extended study containing 288 patients and 288 controls. RESULTS: Thirty-two SNPs were identified through a 13,132 bp sequencing of SCN7A gene. Among them, seven were in regulatory region, ten in coding regions, one in 3'UTR and fourteen in introns. Thirty SNPs were novel SNPs, and a cSNP in exon 18 (SNP021) was associated with hypertension. CONCLUSION: The SNP021 in the gene SCN7A is associated with essential hypertension of Chinese Han population in Shanghai and the role of SCN7A gene in hypertension deserves to be further analyzed.

Adult↗

PubMed2002

Global profiling of the cell surface proteome of cancer cells uncovers an abundance of proteins with chaperone function.

There is currently limited data available pertaining to the global characterization of the cell surface proteome. We have implemented a strategy for the comprehensive profiling and identification of surface membrane proteins. This strategy has been applied to cancer cells, including the SH-SY5Y neuroblastoma, the A549 lung adenocarcinoma, the LoVo colon adenocarcinoma, and the Sup-B15 acute lymphoblastic leukemia (B cell) cell lines and ovarian tumor cells. Surface membrane proteins of viable, intact cells were subjected to biotinylation then affinity-captured and purified on monomeric avidin columns. The biotinylated proteins were eluted from the monomeric avidin columns as intact proteins and were subsequently separated by two-dimensional PAGE, transferred to polyvinylidene difluoride membranes, and visualized by hybridization with streptavidin-horseradish peroxidase. Highly reproducible, but distinct, two-dimensional patterns consisting of several hundred biotinylated proteins were obtained for the different cell populations analyzed. Identification of a subset of biotinylated proteins among the different cell populations analyzed using matrix-assisted laser desorption ionization and tandem mass spectrometry uncovered proteins with a restricted expression pattern in some cell line(s), such as CD87 and the activin receptor type IIB. We also identified more widely expressed proteins, such as CD98, and a sushi repeat-containing protein, a member of the selectin family. Remarkably, a set of proteins identified as chaperone proteins were found to be highly abundant on the cell surface, including GRP78, GRP75, HSP70, HSP60, HSP54, HSP27, and protein disulfide isomerase. Comprehensive profiling of the cell surface proteome provides an effective approach for the identification of commonly occurring proteins as well as proteins with restricted expression patterns in this compartment.

Activin Receptors, Type II↗

PubMed2002

A novel antioxidant mechanism of ebselen involving ebselen diselenide, a substrate of mammalian thioredoxin and thioredoxin reductase.

The antioxidant mechanism of ebselen involves recently discovered reductions by mammalian thioredoxin reductase (TrxR) and thioredoxin (Trx) forming ebselen selenol. Here we describe a previously unknown reaction; ebselen reacts with its selenol forming an ebselen diselenide with a rate constant of 372 m(-1)s(-1). The diselenide also was a substrate of TrxR forming the selenol with K(m) of 40 microm and k(cat) of 79 min(-1) (k(cat)/K(m) of 3.3 x 10(4) m(-1)s(-1)). Trx increased the reduction because of its fast reaction with diselenide (rate constant 1.7 x 10(3) m(-1)s(-1)). Diselenide stimulated the H2O2 reductase activity of TrxR, even more efficiently with Trx present. Because the mechanism of ebselen as an antioxidant has been assumed to involve glutathione peroxidase-like activity, we compared the H2O2 reductase activity of ebselen with the GSH and Trx systems. TrxR at 50 nm, far below the estimated physiological level, gave 8-fold higher activity compared with 1 mm GSH; addition of 5 microm Trx increased this difference to 13-fold. The rate constant of ebselen selenol reacting with H2O2 was estimated to be faster than 350 m(-1)s(-1). We propose novel mechanisms for ebselen antioxidant action involving ebselen selenol and diselenide formation, with the thioredoxin system rather than glutathione as the predominant effector and target.

Animals↗

PubMed2002

Ebselen: a substrate for human thioredoxin reductase strongly stimulating its hydroperoxide reductase activity and a superfast thioredoxin oxidant.

Ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one], a seleno-organic compound with glutathione peroxidase-like activity is used in clinical trials against stroke. Human and bovine TrxR catalyzed the reduction of ebselen to ebselen selenol by NADPH with an apparent K(M)-value of 2.5 microM and a kcat of 588 min(-1). The addition of thioredoxin (Trx) stimulated the TrxR-catalyzed reduction of ebselen several-fold. This result was caused by a very fast oxidation of reduced Trx by ebselen with a rate constant in excess of 2 x 10(7) M(-1) s(-1). This rate is orders of magnitude faster than the reaction of dithiol Trx with insulin disulfides. Ebselen competed with disulfide substrates for reduction by Trx and, therefore, acted as an inhibitor of protein disulfide reduction by the Trx system. The inherent H2O2 reductase activity of mammalian TrxR dependent on its active-site selenocysteine residue was stimulated 10-fold by 2 microM ebselen and 25-fold in the additional presence of 5 microM Trx. Furthermore, the apparent K(M)-value of TrxR for H2O2 was lowered 25-fold to about 100 microM. Our results demonstrate that ebselen is a TrxR peroxidase which, in the presence of Trx, acted as a mimic of a peroxiredoxin. The activity with TrxR and oxidation of reduced Trx offer mechanistic explanations for the in vivo effects of ebselen as an antioxidant and anti-inflammatory agent. Our results demonstrate that the mechanism of action of ebselen may be predominantly via the Trx system rather than via glutathione.

Azoles↗

PubMed2002

[Rapid determination of metallothioneins in foods by capillary zone electrophoresis].

A rapid method for the analysis of metallothioneins (MT) in foods by capillary zone electrophoresis(CZE) was developed. Two isomers of MT (MT1, MT2) in foods were separated and determined. After a series of optimization, the separation and determination of MT1 and MT2 were obtained within 10 min by using the phosphate buffer system consisting of 0.02 mol/L Na2HPO4 and 0.02 mol/L NaH2PO4 (pH 7.0), and UV detection at 200 nm. Under the optimal experimental conditions, the minimum detectable limit was 1 mg/L, and the added standard recoveries of MT1, MT2 in foods were found to be in the range of 82.0%-93.4%. The relative standard deviations (RSD) were found to be lower than 10%. Therefore, with this simple and rapid method, the contents of two isomers in foods can be determined by external standard method after sample pretreatment.

Animals↗