Biomedical subjects

Zhi-Qi Zhang

Publications and source records attributed to Zhi-Qi Zhang.

3 recordsLinked to original sources

PubMed2006

Cardiac muscle sarcolemma chromatographic stationary phase and its potential application in drug screening.

A new bioactive packing material for liquid chromatography, sarcolemma chromatography stationary phase (SCSP), is presented. Its surface characteristics are investigated, and it is found that the acceptors embedded in sarcolemma remained bioactive for more than a week. The retention behavior of antagonists and activators related to cardiac muscle sarcolemma on the SCSP chromatographic column shows the screening function of the SCSP column, and the retention behavior of the active components in the aether extract from the Chinese herb Ligusticum chuanxiong Hort. on the SCSP column reveals, to a certain extent, the separation function of the SCSP column. These suggest that SCSP is a potentially useful material in drug screening.

Ligusticum↗

PubMed2006

Gene expression changes after hypoxic preconditioning in rat hepatocytes.

BACKGROUND: Hypoxic preconditioning can protect hepatocytes against hypoxic injury, but its mechanism has not been elucidated. The aim of this study was to profile gene expression patterns involved in hypoxic preconditioning and probable mechanism at the level of gene expression. METHODS: Hepatocytes were divided into 2 groups: control group and hypoxic preconditioning group. Biotin-labeled cRNA from the control group and the hypoxic preconditioning group was hybridized by oligonucleotide microarray. Genes that were significantly associated with hypoxic preconditioning were filtered, and validated at the level of transcript expression. RESULTS: Forty-three genes with significantly altered expression patterns were discovered and most of them had not been previously reported. Among these genes, genes encoding superoxide dismutase 2 (SOD2) and interleukin 10 (IL-10) in the hypoxic preconditioning group were confirmed to be up-regulated with real-time quantitative PCR. CONCLUSIONS: Many cytokines are involved in hypoxic preconditioning and protect hepatocytes from hypoxia-reoxygenation injury, and the increase of oxygen free-radical scavengers and anti-inflammatory factors may play a key role in this phenomenon. Diverse signal pathways are probably involved.

Animals↗

PubMed2004

Solid-phase reactor flow-injection on-line oxidizing spectrofluorimetry for determination and dissolution studies of folic acid.

A simple, sensitive and specific flow-injection spectrofluorimetric method has been developed for the determination of folic acid in pharmaceuticals. The method is based on use of a lead dioxide solid-phase reactor for on-line oxidation of folic acid into a strongly fluorescent compound with a maximum excitation wavelength of 281 nm and an emission wavelength of 450 nm. Under optimum conditions the fluorescence intensity of oxidation product is proportional to the concentration of folic acid over the range 0.008-2.5 microg mL(-1). The detection limit is 0.0001 microg mL(-1), the relative standard deviation is 0.85% for 11 replicate determinations of 0.05 microg mL(-1) folic acid, and the sample throughput is 20 h(-1). In combination with an on-line filter and dilution, an automated drug-dissolution system was established. The proposed method has been successfully applied to the determination of folic acid in pharmaceutical preparations and dissolution testing.

Flow Injection Analysis↗