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Biomedical subjects

I K Kim

Publications and source records attributed to I K Kim.

84 records · Page 5Linked to original sources

[Primary multiple cancer of both lungs].

The study summarizes the experience gained in the treatment of 46 cases of bilateral primary multiple cancer of the lung (synchronous cancer--17 and metachronous--29). Criteria for establishing primary multiple cancer and choice of treatment procedure are suggested. Surgery for bilateral cancer was carried out in 15 cases (metachronous tumor--11; synchronous--4). Radiation treatment was given to 8 patients (synchronous tumor--4, metachronous--4) and chemotherapy--to 7 patients (synchronous tumor--2, metachronous--5). The advantages offered by active surgical intervention in management of primary multiple bilateral cancer of the lung are discussed.

Adenocarcinoma↗

S-Adenosylhomocysteine hydrolase from hamster liver: purification and kinetic properties.

3-Deazaadenosine is both an inhibitor of and a substrate for S-adenosylhomocysteine hydrolase. Its administration to rats results in the accumulation of both S-adenosylhomocysteine and 3-deazaadenosylhomocysteine in the liver and other tissues. In hamsters, however, the administration of 3-deazaadenosine results only in the accumulation of 3-deazaadenosylhomocysteine (P. K. Chiang and G. L. Cantoni (1979) Biochem. Pharmacol. 28, 1897). In order to investigate the possible reasons for this difference, S-adenosylhomocysteine hydrolase from hamster liver has been purified to homogeneity and some of its kinetic and physical parameters have been determined. The molecular weight of the native enzyme is 200,000 with a subunit molecular weight of 48,000. The Km's for adenosine and 3-deazaadenosine are about 1.0 microM, and the Vmax's are also similar. The Km for S-adenosylhomocysteine is 1.0 microM, or more than 10 times smaller than the Km of the rat liver enzyme. This difference in Km value may explain the differences in the response of rat and hamster liver to the administration of 3-deazaadenosine. S-Adenosylhomocysteine hydrolase from hamster liver exhibits an interesting kinetic property in that its activity can be affected bimodally by either adenosine or adenosine analogs. At very low concentrations of these analogs, the activity of S-adenosylhomocysteine hydrolase can be stimulated by 10-30%, and at higher concentrations these same analogs become competitive inhibitors.

Adenosine↗

Mechanism of the cytostatic activity of 3-deazaaristeromycin, an inhibitor of adenosylhomocysteine hydrolase.

3-Deazaaristeromycin (100 microM) is cytostatic for the RAW264 mouse macrophage cell line. In cells incubated with 3-deazaaristeromycin, Cell replication is effectively stimulated by 0.5 microM homocysteine thiolactone and no further stimulation occurs at concentrations of homocysteine thiolactone greater than 50 microM. Cell replication occurs when homocysteine thiolactone is administered either simultaneously with, or 4 days after, the administration of 3-deazaaristeromycin. In the presence of 3-deazaaristeromycin, cell replication also occurs when either folate (10 to 100 microM) or hypoxanthine and thymidine are included in the medium. Incorporation of [14C]formate into trichloroacetic acid-precipitable material is inhibited when cells are incubated with 3-deazaaristeromycin, and this inhibition is partially reversed by inclusion of either homocysteine thiolactone or folate in the medium. Experiments showed that adenosylhomocysteine hydrolase is inhibited to the same extent after the cells have been incubated for 4 days with either 3-deazaaristeromycin or 3-deazaaristeromycin and homocysteine thiolactone. The findings suggest that in cells incubated with 3-deazaaristeromycin, the formation of homocysteine from S-adenosylhomocysteine is insufficient for the regeneration of tetrahydrofolate for the synthesis of purines and pyrimidines.

Adenosine↗

Local Shwartzman-like phenomenon prepared with haptoglobin-hemoglobin complex and provoked with prostaglandin.

Intradermal injection of haptoglobin-hemoglobin (Hp-Hb) complex followed by intravenous injection of prostaglandin (PG) F2a or E2 produced a local Shwartzman-like phenomenon (LSLP) in rabbits, whereas PGE1 has no provoking action. Intradermal injection of hemoglobin or erythrocytes also produced LSLP when provoked with endotoxin or PGF2alpha. The provoking action of endotoxin in the local shwartzman reaction may not be entirely mediated through PGs.

Animals↗

Rapid prenatal diagnosis of trisomy 21 by polymerase chain reaction- associated analysis of small tandem repeats and S100B in chromosome 21.

OBJECTIVES: The incidence of Down syndrome increases with maternal age and a rapid and accurate method for prenatal diagnosis is a necessity. This study was devised to evaluate and compare the methods for detecting trisomy 21 by polymerase chain reaction (PCR)-associated analysis of small tandem repeats (STR) of D21S11 and semiquantitative analysis of S100B of chromosome 21. METHODS: PCR was performed with DNA template obtained from 20 normal samples (10 blood, 10 amniotic fluid) and 12 Down syndrome samples (10 blood, 2 amniotic fluid). 32P-labelled primers for D21S11 and S100B were used. PCR products for D21S11 were subjected to polyacrylamide urea gel (6%) electrophoresis, followed by exposure to X-ray film, and then the densities of signals were recorded by densitometer. PCR products for S100B and insulin-like growth factor-I (IGF-I) as an internal control were subjected to agarose gel (2%) electrophoresis and the relative amounts of radioactivity in their products were measured to assess the quantitation of template DNA. RESULTS: Analysis of D21S11 STR showed equivalent triplets in 4 cases and unequivalent doublets (1:2) in 8 Down syndrome samples. The normal control group showed singlets in 5 cases and equivalent doublets in 15 cases. In the analysis of S100B, the ratios of S100B to IGF-I was 1.4-1.6 in 7 of 12 Down syndrome samples, while the ratios of S100B in all normal samples were close to 1.0. All the results were obtained within 24 h. The D21S11 STR analysis managed to distinguish more clearly between normal and trisomy 21, while semiquantitative PCR analysis of S100B was less able to assess trisomy 21. CONCLUSION: Prenatal diagnosis of trisomy 21 by PCR-associated STR analysis of D21S11 and semiquantitative analysis of S100B are useful, innovative, accurate and rapid diagnostic methods, while D21S11 STR analysis is more discriminating in detecting trisomy 21 and also may be employed in preimplantation diagnosis of Down syndrome.

Calcium-Binding Proteins↗