Search PubMed⌕ Search

Biomedical subjects

F J Yang

Publications and source records attributed to F J Yang.

7 recordsLinked to original sources
PubMed2000

Effect of total flavonoids of hippophae rhamnoides on contractile mechanics and calcium transfer in stretched myocyte.

OBJECTIVE: To study the role of total flavonoids of hippophae rhamnoides in improving contractile [correction of contactile] function of stretched cardiac myocyte. METHOD: Flavonoids were given to stretched myocytes which were proved their contractile function decline and then myocyte contractile mechanics characteristics and calcium transfer were measured. RESULT: Flavonoids increased myocyte contractility, as indicated by myocyte shortening, velocity of shortening, peak +dL/dt and peak -dL/dt during shortening, in a concentration-dependent manner (r>0.9, P<0.001), and with no relation to the intracellular calcium transfer in the myocytes. CONCLUSION: Flavonoids of the traditional Chinese drug hippophae rhamnoides is effective in improving the contractile function of stretched cardiac myocyte in low dosage.

Animals↗
PubMed1994

Scavenging effects of tetramethylpyrazine on active oxygen free radicals.

The scavenging effects of tetramethylpyrazine (ligustrazine, Lig) isolated from Ligusticum wallichii Franch on active oxygen free radicals were studied using spin trapping technic and chemiluminescence methods. The scavenging rate of superoxide anion (O2-.) by Lig (25 mg.ml-1) was 100% in xanthine/xanthine oxidase (Xan/XO) system, and that of hydroxyl radical (OH-.) was 44% in Fenton's reaction. The scavenging rate of lipid peroxyl radical (LOO-.) by Lig (25 mg.ml-1) was 80% in peroxidizing microsome system. It is possible that Lig scavenged O2-. by catalyzing its spontaneous dismutation. The results showed that Lig had strong effects of scavenging cyotoxic oxygen free radicals (O2-., LOO-., OH-.).

Animals↗
PubMed1990

Changes in female sexual behavior of old female rats: comparison between exit method and non-exit method.

The female sexual behavior including proceptivity, receptivity and sociosexual behavior of preferential approach to males was tested in 12 young adult female rats aged from 6 to 7 months and in 59 old female rats aged from 18 to 21 months with the exit method and the traditional non-exit method. The percentage of rats displaying a high lordosis quotient (LQ) and that of rats showing solicitation were lower in old females than in young females tested either with the non-exit method or the exit method. Only with the non-exit method were the mount frequency per minute of male rats toward old females of the high-LQ group and the solicitation score of old female rats lower as compared to young females. The incidence of preferential approach of the female rats, whether young or old, toward intact young males and their time spent in the compartment of intact young males were not different, however, the frequency of old female rats to visit the arena of intact young males was lower than that of young females. In summary, the major age-related changes in female sexual behavior, the low percentage of rats displaying high LQ and of rats showing solicitation, are quite robust and environmentally independent.

Age Factors↗
PubMed1977

Flow field-flow fractionation: new method for separating, purifying, and characterizing the diffusivity of viruses.

The nature and theory of flow field-flow fractionation is described, and its potential applicability to virus-like particles is discussed. Different virus types are shown to be retained at different levels. Retention can be controlled by variation of the experimental parameters, in good agreement with theory. However, a mild adsorption effect is indicated and requires the development of alternate strategies for measuring diffusion coefficients. For Qbeta, our value agrees well within 10% of literature values; the values obtained for other viruses, using Abeta as an internal standard, are untested. Finally, it is demonstrated that flow field-flow fractionation can cleanly fractionate two viruses from one another and from an albumin impurity, that samples as large as several milligrams in size can be analyzed, and that the method has potential utility in the quantitative and qualitative analysis of virus systems.

Albumins↗
PubMed1976

Flow-field-flow fractionation: a versatile new separation method.

Flow-field-fractionation is a new separation technique that seems likely to have broad applicability. Its theoretical scope includes any solute for which one can find a solvent and a semipermeable membrane. The principles on which the technique is based are presented. Some experiments with polystyrene beads, viruses, and proteins verify that retention depends solely on diffusion coefficients.

Chemical Fractionation↗