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Xue-mei Ma

Publications and source records attributed to Xue-mei Ma.

4 recordsLinked to original sources
PubMed2005

[Influence of platelet activating factor and its antagonist on portal hypertension associated with liver cirrhosis: an experiment with rats].

OBJECTIVE: To investigate the influence of platelet activating factor (PAF) and its antagonist BN52021 on portal hypertension associated with liver cirrhosis. METHODS: Ten SD rats were injected intraperitoneally with carbon tetrachloride to establish a liver cirrhosis model and 10 rats were injected with olive oil as controls. The concentrations of PAF in the blood and liver was examined by rapid (3)H-PAF scintillation proximity assay and the hepatic PAF binding capacity was examined by receptor saturation binding technique. The pressure of portal vein and pressure of femoral artery were measured by intubation method. BN52021 was infused into the portal vein to observe its influence on the blood pressure. RESULTS: The hepatic PAF levels of the cirrhotic rats was 4.0 ng/g +/- 0.4 ng/g, significantly higher than that of the control rats (2.7 ng/g +/- 0.5 ng/g, P < 0.01). The hepatic efflux PAF level of the cirrhotic rats was 6.3 ng/g +/- 0.6 ng/g, significantly higher than that of the control rats (3.4 ng/g +/- 0.6 ng/g, P < 0.01). The hepatic output PAF levels of the cirrhotic rats was 1.0 ng/g +/- 0.6 ng/g, significantly lower than that of the control rats (0.3 ng/g +/- 0.5 ng/g, P < 0.01). The maximum PAF binding capacity of the cirrhotic rats was 2.8 +/- 0.21 fmol/microg protein, significantly higher than that of the control rats (0.9 +/- 0.06 fmol/microg protein, P < 0.01). However, the receptor affinity was not significantly different between these 2 groups. The portal pressure of the cirrhotic rats was 12.2 mm Hg +/- 0.7 mm Hg, significantly higher than that of the control rats (5.3 mm Hg +/- 0.6 mm Hg, P < 0.01). The femoral arterial pressure of the cirrhotic rats was 82 mm Hg +/- 10 mm Hg, significantly lower than that of the control rats (114 mm Hg +/- 9 mm Hg, P < 0.01). Infusion of PAF via the portal vein increased the portal pressure from 12.1 mm Hg +/- 0.6 mm Hg with an increase of 32% (P < 0.01) in the cirrhotic rats, and from 7.7 mm Hg +/- 0.8 mm Hg with an increase of 23%. The PAF response of the cirrhotic rats was 4.1 mm Hg +/- 1.0 mm Hg (227%), significantly higher than that of the control rats (1.8 mm Hg +/- 0.3 mm Hg, P < 0.01). The femoral artery pressure decreased from 82 mm Hg +/- 10 mm Hg to 48 mm Hg +/- 4 mm Hg (P < 0.01) in the cirrhotic rats, and from 114 mm Hg +/- 9 mm Hg to 52 mm Hg +/- 4 mm Hg (P < 0.01). After portal infusion of BN52021 the portal pressure decreased from 14.6 mm Hg +/- 1.6 mm Hg to 12.3 mm Hg +/- 0.8 mm Hg (P < 0.05) with a decrease of 16%, however, did not significantly influenced the femoral arterial pressure in the cirrhotic rats, and did not significantly influenced the portal pressure and femoral arterial pressure in the control rats. CONCLUSION: The increased hepatic PAF synthesis in cirrhotic is the major source of elevated circulating PAF It upregulates the hepatic hemodynamics that contributes to portal hypertension. The increased portal pressure by endogenous PAF can be decreased to a certain extent by BN52021 which may be used in treatment of portal hypertension.

Animals↗
PubMed2005

[Effects of gamma-interferon on gene expression of collagen I, III and on the tissue inhibitor of metalloprotenase 1 in HSC-T6 cells].

OBJECTIVE: To observe the in vitro effects of gamma-interferon (IFNgamma) on gene expression of collagen I (Col I), III (Col III) and tissue inhibitor of metalloprotenase 1 (TIMP1) of HSC-T6 cells. METHODS: Cultured HSC-T6 cells were exposed to IFNgamma at concentrations of 0.1, 1, 10, 10(2), 10(3), 10(4), 2.5 x 10(5), 5 x10(5) U/ml for 48 hours. 4,5-simethylthiazaoly colormetric assay was used to evaluate the effect of IFNgamma on HSC-T6 cell proliferation. After incubating with IFNgamma (1 U/ml, 10(2) U/ml and 10(4) U/ml) for 48 hours, HSC-T6 cells were harvested to detect Col I, Col III and TIMP1 steady state mRNA levels by quantitative reverse-transcription polymerase chain reaction (RT-PCR). RESULTS: The Col I, Col III and TIMP1 mRNA levels of the control group were 2.86+/-0.21, 2.00+/-0.23 and 3.90+/-0.81, respectively. Col I and Col III mRNA levels in HSC-T6 cells treated by different concentrations of IFNgamma were lower than that of the controls (P < 0.01). There was no significant difference in TIMP1 mRNA levels between IFNgamma groups and controls. CONCLUSION: IFNgamma suppresses expression of Col I and Col III whereas it has no effect on TIMP1 mRNA expression. The antifibrotic mechanism of IFNgamma may be partly due to its down-regulation of Col I and Col III mRNA levels in HSC-T6 cells.

Animals↗
PubMed2003

Blocking oligo--a novel approach for improving chip-based DNA hybridization efficiency.

For most of the commonly used DNA chips, the probes are usually single-stranded oligonucleotides and the targets are double-stranded DNAs (dsDNAs). Only one strand of the DNA serves as the target while the other competes with the probes immobilized on the chip for the target and therefore is regarded as the interfering strand. In this report, a novel technique was developed for improving the hybridization efficiency on DNA chips by using blocking oligos, which is complimentary to the target interfering strand to reduce the influence of the interfering strand. The hybridization efficiency of dsDNA was much lower than that of single-stranded DNA (ssDNA) when synthesized DNA targets were tested on the DNA chip. Blocking oligos can improve the hybridization efficiency of dsDNA to about 2/3 that of ssDNA. Blocking oligos have also been applied to PCR products of different lengths for hybridization. The hybridization efficiency with blocking oligos is about three times higher than that without blocking oligos. We have tested PCR products of 1054 and 435 bp using our blocking procedure, and the results are consistent.

DNA↗