Biomedical subjects

Liu Fang

Publications and source records attributed to Liu Fang.

3 recordsLinked to original sources

PubMed2005

A gravimetric simplified method for nucleated marrow cell counting using an injection needle.

A simplified gravimetric marrow cell counting method for rats is proposed for a regular screening method. After fresh bone marrow was aspirated by an injection needle, the marrow cells were suspended in carbonate buffered saline. The nucleated marrow cell count (NMC) was measured by an automated multi-blood cell analyzer. When this gravimetric method was applied to rats, the NMC of the left and right femurs had essentially identical values due to careful handling. The NMC at 4 to 10 weeks of age in male and female Crj:CD(SD)IGS rats was 2.72 to 1.96 and 2.75 to 1.98 (x10(6) counts/mg), respectively. More useful information for evaluation could be obtained by using this gravimetric method in addition to myelogram examination. However, some difficulties with this method include low NMC due to blood contamination and variation of NMC due to handling. Therefore, the utility of this gravimetric method for screening will be clarified by the accumulation of the data on myelotoxicity studies with this method.

Age Factors↗

PubMed2004

Effect of dopamine on inflammatory status in kidneys of brain-dead rats.

BACKGROUND: Brain death has been identified as an independent risk factor for chronic allograft dysfunction. In two independent retrospective clinical studies, we showed that dopamine treatment of brain-dead donors improves long-term kidney graft survival. The mechanisms underlying the protective effects of dopamine treatment in vivo have not been identified. To elucidate the mechanisms underlying the protective effect of dopamine on kidneys of brain-dead donors, we studied a model for brain death in rats. METHODS: In F344 rats, brain death was induced by epidural inflation of a 3F Fogarty catheter. Apneic animals were mechanically ventilated, and clinically relevant dosages of dopamine (2, 6, 10, or 14 microg/kg/min) were given for 6 hr from the onset of brain death. Ventilated, non-brain-dead animals served as controls. RESULTS: Dopamine significantly reduced renal monocyte infiltration and major histocompatibility class II and P-selectin expression in brain-dead animals. It also prevented further up-regulation of the inflammatory markers tumor necrosis factor-alpha and monocyte chemoattractant peptide-1. Concomitantly, the presence of inducible anti-oxidant heme oxygenase-1, known for its cytoprotective effects, was strongly increased by dopamine. CONCLUSION: We identified several mechanisms underlying the protective effects of dopamine treatment on kidney grafts. The identification of these mechanisms may help to design more effective future strategies for treatment of cadaveric kidney donors.

Animals↗

PubMed2002

Quantum dispersion and its exponential growth of a wave packet in chaotic systems.

The quantum correspondence of one particular signature of classical chaos--the exponential instability of motion--can be characterized by the initial exponential growth rate of the spreading of the propagating quantum wave packet. The growth rate is approximately twice the classical maximum Lyapunov exponent of the system. In the regular case, the dispersion of the wave packet is only due to the usual quantum effect that should vanish in the classical limit. In contrast, in the chaotic case, the evolution behavior of the wave packet is due to the dynamical effect associated with the nonlinearity and persists as long as the spatial extension of the initial wave packet is kept finite.

Journal Article↗