Biomedical subjects

Z Y Yu

Publications and source records attributed to Z Y Yu.

4 recordsLinked to original sources

PubMed1992

Increase in plasma thrombomodulin and decrease in plasma von Willebrand factor after regular radiotherapy of patients with cancer.

In this study, we investigated plasma levels of thrombomodulin (TM) and von Willebrand factor (vWF) in 51 patients suffering from cancer or tumor undergoing 60 cobalt radiotherapy. Plasma TM and vWF antigen were measured by immunoradiometric assay and ELISA, respectively. During radiotherapy, an increase in plasma TM in patients was observed, which was radiation-dose dependent and there was a positive correlation between plasma TM level and radiation doses. However, the level of plasma vWF in the patients was decreased during radiotherapy and there was an inverse correlation between the amount of plasma vWF and radiation doses. Our data indicate that plasma TM is an useful molecular marker for early detection of radiation injury to endothelial cells in patients undergoing radiotherapy.

Adolescent↗

PubMed1992

Mutations on free and integrated hepatitis B virus DNA in a hepatocellular carcinoma: footprints of homologous recombination.

Hepatitis B virus nucleotide sequences derived from a hepatocellular carcinoma with free and multiply integrated viral DNAs were determined. Based on a comparison within the X-gene region, cloned free viral DNA previously had been attributed to two distinct groups of preC minus genomes. The comparison of the complete sequence identified one of the genome equivalents as a recombinant between members of these groups. Four different integrated viral DNA elements were cloned and analysed. Similarity to either one of two DNAs representing the two groups of free viral DNA on one hand and the presence of certain mutations only on integrated DNA on the other hand, allowed to recognize distinct segments within the integrants. The data suggest a contribution of different but related genotypes to contiguous stretches of integrated viral DNA via homologous recombination. On this basis an evolutionary relationship between free and integrated DNAs of the preC and the preC minus genotype could be recognized when short sequence segments were compared. The observed coexistence on a given integrated DNA of segments homologous to free viral DNA and of segments homologous to another integrated DNA is consistent with (1) a long lasting association of individual genotypes with dividing cells and (2) multiple integration events being the result of a series of steps not separated by a long time span.

Base Sequence↗

PubMed1990

[Effect of endothelin on the release of angiotensin II from rat cardiovascular system].

The existence of angiotensin II immunoreactive substance in rat cardiovascular system was demonstrated by RIA and immunohistochemistry techniques. In atrium, aorta and cultured rat aorta smooth muscle cells, angiotensin II content is 7.2 + 2.7 pg/mg protein, 152.4 + 59.2 pg/mg protein and 3.5 + 0.8 pg/2 x 10(5) cells respectively. Endothelin, a potent vasoconstricting polypeptide, can enhance the release of angiotensin II from cultured rat aorta and aortic smooth muscle cells significantly. The results suggest that endothelin may be involved in the regulation of local blood flow and vascular tone, and it may also implicate the pathogenesis of some cardiovascular diseases such as cardiohypertrophy and vascular hypertrophy.

Angiotensin II↗

PubMed1990

[IR spectra resolution of pure components for unknown mixtures].

The spectral resolution into individual components from a set of unknown mixture IR spectra was investigated. The method based on iterative target transformation of factor analysis is developed and used to treat several three-component and two-component mixture systems of amino-acids. The results show that the method proposed in this paper is applicable.

Amino Acids↗