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Biomedical subjects

S Chen

Publications and source records attributed to S Chen.

At least 1,531 records · Page 85Linked to original sources
PubMed1978

Nonrandom inclusion of H-2K and H-2D antigens in Friend virus particles from mice of various strains.

Friend murine leukemia virus (FV), isolated from infectious serum of several mouse strains, has been examined for the presence of H-2 antigens. Following banding of the virus on a discontinuous sucrose gradient, pelleting, and disruption with Nonidet P-40 detergent, virus preparations were tested for their capacity to inhibit the lysis of target cells mediated by various anti-H-2K or anti-H-2D antisera. Virus from mice homozygous for the H-2b, H-2d, H-2g H-2k, and H-2ol haplotypes or heterozygous for the H-2g/H-2k, H-2b/H-2d, and H-2b/H-2k haplotypes was used. Of the six H-2D or H-2K alleles examined, the products of only two, H-2Db and H-2Kk were detected. Virus preparations contained no, one, or both antigens, depending on the genotype of the host animal. Control preparations from normal mouse serum and preparations in which the virus had not been disrupted demonstrated no H-2 activity. Furthermore, attempts to neutralize FV spleen focus forming activity with anti-H-2Db or anti-H-2Kk antisera yielded negative results.

Animals↗
PubMed1977

Inhibition of leukocyte migration by tumor-associated antigen in soluble extracts of human hepatoma.

The leukocyte migration inhibition assay was used to detect cell-mediated immune reaction of hepatoma patients. Extraction of 3 pairs of human hepatoma tissue and normal liver tissue was made by 3 M KCI solution, and soluble hepatoma antigens were used to test against leukocytes of 18 hepatoma patients by the leukocyte migration inhibition assay. In all, 25 tests were performed; most of them were allogenic, and only 3 tests were autologous. Migration inhibition was observed in 13 of 25 tests, and there were only a few cases of migration inhibition in the control groups. It was concluded that tumor-associated antigen of human hepatoma was contained in the 3 M KCI extract of hepatoma tissue and that tumor-associated antigen of human hepatoma was shared by some hepatoma patients.

Antigens, Neoplasm↗
PubMed1977

Valve replacement in children.

Since 1964, 27 valve replacements have been performed in patients who ranged from 5 months to 20 years of age. Fourteen underwent aortic valve replacement, 10 underwent mitral valve replacement, two had systemic atrio-ventricular valve replacement, and one had tricuspid valve replacement. Nineteen patients had congenital heart disease, five had rheumatic disease, and three had Marfan's syndrome. Starr-Edwards prostheses were used in 17 patients, Björk-Shiley prostheses in six, and procine xenografts in for. There were five early deaths and five late deaths. Patients were followed for 2 months to 6 years postoperatively (mean 2.1 years). All survivors showed clinical improvement. There were no episodes of thromboembolism. Minor bleeding, arrhythmias, and bacterial endocarditis occurred infrequently.

Adolescent↗
PubMed1976

Genetic homology between man and the chimpanzee: syntenic relationships of genes for galactokinase and thymidine kinase and adenovirus-12-induced gaps using chimpanzee-mouse somatic cell hybrids.

The induction by adenovirus-12 of a site-specific gap and assignment of the chimpanzee genes for thymidine kinase and galactokinase were studied by utilizing chimpanzee-mouse hybrid cells. It has been shown that adenovirus-12 induces a specific gap in the long arm of human chromosome 17 (HS 17); with chimpanzee-mouse hybrid cells the specific gap appears on the short arm of the chimpanzee homolog [PTR 19 (HS 17)] of HS 17. This result supports the proposed relationship of HS 17 to PTR 19 (HS 17) by means of a pericentric inversion. The chimpanzee thymidine kinase and galactokinase genes were assigned to PTR 19 (HS 17), further confirming the homology to HS 17. Other syntenic relationships and gene assignments were consistent with proposed homologies between chimpanzee and human chromosomes.

Adenoviridae↗
PubMed1976

Differential staining of interspecific chromosomes in somatic cell hybrids by alkaline Giemsa stain.

Staining of chromosome preparations of Chinese hamster-human hybrid cells and mouse-chimpanzee hybrids with alkaline Giemsa has yielded color differentiation of the interspecific chromosomes. Bicolor chromosomes, indicating apparent translocations also are observed for each of these hybrids. The specific color differences observed provide a rapid means of recognizing and aiding in the identification of the interspecific chromosomes and apparent translocations in these somatic cell hybrids.

Azure Stains↗
PubMed1976

Aortic aneurysm in childhood: report of six instances.

Six instances of aortic aneurysm in children have been observed in the past 15 years. Four children with aortic stenosis and coarctation of the aorta had aneurysmal dilatation of the ascending aorta, and two children with coarctation of the aorta had ruptured post-stenotic dilatation of the descending aorta. Our observations suggest that aortic aneurysm can be the result of hemodynamic stress, although developmental anomaly of the aorta associated with aortic stenosis or coarctation could be responsible for the development of the aneurysm.

Adolescent↗
PubMed1976

Japanese encephalitis virus in Northern Taiwan, 1969-1973.

Sentinel pigs were bled and mosiquitoes were collected for isolation of Japanese encephalitis virus (JEV) between 1969 and 1973 in a rural area of northern Taiwan which reported a high annual incidence of human cases. The study site included a farmyard, schools, a bat cave, rice paddies and a heronry. Although Culex annulus was collected in every month of the year, isolations were made only in midsummer and only from Culex annulus and (once) from Culex tritaeniorhynchus. These isolates were usually collected from pig-related sources. Human cases in the vicinity of the study site were reported 3 to 6 weeks following the initial isolations from sentinel pigs. Isolations were made only for 4 to 8 weeks each summer. The isolation of JEV was not related to the availability of susceptible pigs or the spring or summer peaks in prevalence of Culex annulus. Despite periodic draining of rice paddies and the application of insecticides, sufficient numbers of Culex annulus were available to support transmission of JEV in each year of the study.

Animals↗