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Biomedical subjects

W J Kim

Publications and source records attributed to W J Kim.

At least 109 records · Page 6Linked to original sources

Epikeratoplasty for keratoconus.

The 6 eyes of 6 patients operated on using keratoconic epikeratoplasty are evaluated, and the mean 11-month postoperative results are reported. Uncorrected visual acuities improved in 4 patients and were maintained in 1 patient. One patient revealed a decrease of uncorrected visual acuity in the postoperative 6th month. Two patients showed an improvement of over 2 Snellen lines. Two patients showed the same corrected visual acuity, and that of 2 patients decreased within the postoperative 6-months follow-up. There was a significant decrease of myopia in terms of spherical equivalent. As a result, 4 cases showed a postoperative refractive error from +1.0 to -2.5D. Two cases were myopic deviated, -4.0 and -5.0D, and need further observation. In all cases, there was an effective flattening of the protruding cone with a mean decrease of over 11D of keratometry readings. Complete reepithelization occurred within 12 days, (average 7.5 days) and a moderate pressure patch was used as a routine procedure to promote the reepithelization.

Adolescent↗

Synthesis and biological activity of novel 3-(2-propenyl)-cephalosporins. I.

The synthesis, antibacterial activity and oral absorption of novel cephalosporins (3a-3d) having a 2-propenyl group at the C-3 position are described. Diphenylmethyl 7-amino-3-(2-propenyl)-3-cephem-4-carboxylate HCl (4) prepared from 7-aminocephalosporanic acid in 12 steps was acylated with various acid moieties to give cephems 3a-3d. The cephems 3a-3c showed similar antibacterial activities as cefixime. However, these cephems were not well absorbed orally.

Absorption↗

Synthesis and biological activity of novel 3-(2-propenyl)-cephalosporins. II. Preparation of prodrugs.

Three prodrug esters (2a approximately 2c) of 3-(2-propenyl)cephem (1a) have been prepared and their oral absorption was determined in rats and mice. While pivaloyloxymethyl ester (2a) did not improve the oral absorption of the parent cephem 1a, [(1-methyl)ethoxycarbonyloxy]ethyl ester (2b) and (5-methyl-2-oxo-1,3-dioxolen-4-yl)methyl ester (2c) improved oral absorption by a factor of five.

Absorption↗

Inhibition of topoisomerase I by NAD and enhancement of cytotoxicity of MMS by inhibitors of poly(ADP-ribose) polymerase in Saccharomyces cerevisiae.

The activity of DNA topoisomerase I present in the nuclear extract of yeast, Saccharomyces cerevisiae, was inhibited by additions of NAD, the substrate of poly (ADP-ribose) polymerase. This NAD-inhibited topoisomerase activity was restored to the normal level in a dose-dependent manner by adding 3-aminobenzamide (3-AB), an inhibitor of the polymerase. The 3-AB sensitive polymerase enzyme activity, as determined by the rate of incorporation of the radiolabelled NAD in permeabilized cells, increased by treatment of cells with methyl methanesulfonate (MMS) in a dose-dependent manner. While the additions of MMS increased the polymerase activity, it has caused a decrease in cell survival. However, this cell killing activity of MMS was markedly potentiated by adding benzamide, another inhibitor of polymerase. Thus, these results suggest that the mode of modification of nuclear proteins by altering the poly(ADP-ribosylation) in S. cerevisiae resembles with those observed in mammalian cells.

Benzamides↗

Suicide attempts and ideation: adolescents evaluated on a pediatric ward.

This study compared psychological, familial, and demographic data for 42 suicidal, 16 suicide ideation, and 42 control pediatric patients. Chaotic families and behavior problems, as well as depression, constriction, and lack of insight, differentiated the suicide attempt group from the control group. The suicide ideation group was similar to both the control and suicide attempt groups and seen as "intermediate" between these two. In assessing lethality of the attempt, constriction was the only predictor differentiating the serious from less serious suicide attempt.

Adolescent↗

Antagonistic interactions between alleles of the RpII215 locus in Drosophila melanogaster.

The RpII215 locus encodes the large subunit of RNA polymerase II (polII). Three of 22 RpII215 alleles cause a synergistic enhancement of the mutant phenotype elicited by mutations in the Ultrabithorax (Ubx) locus. We have recovered and analyzed three new mutations that suppress this enhancement. All three mutations map to the RpII215 locus. In addition to suppressing the Ubx enhancement of other RpII215 alleles, two of the new mutations, JH1 and WJK2, themselves enhance Ubx. RpII215 alleles can be placed into three classes based on their ability to enhance Ubx. Class I alleles, including Ubl, C4, C11, JH1, and WJK2, enhance Ubx when heterozygous with class II alleles, which include wild-type RpII215. Class III alleles, which include amorphic alleles, do not enhance Ubx. The third new mutation, WJK1, is a conditional amorphic allele, which behaves like a class III allele at 29 degrees but like a class II allele at 19 degrees. Another mutant phenotype is caused by certain RpII215 alleles, including all class I alleles. This phenotype is a synergistic enhancement of a mutant phenotype elicited by mutations at the Delta (Dl) locus. Unlike the enhancement of Ubx, the enhancement of Dl is not dependent upon antagonistic interactions between different classes of RpII215 alleles.

Alleles↗

Heat-shock treatment lethal for mammalian cells deprived of glucose and glutamine: protection by alpha-keto acids.

Nil and Nilpy hamster cells exposed to temperatures of 44 degrees C to induce the heat-shock proteins survive such exposure for 2 h or more when incubated in Eagle's Minimum Essential Medium with 10% undialyzed fetal calf serum. If D-glucose and L-glutamine are withdrawn from the medium during heat treatment, nearly all the cells are killed by as little as 20 min at 44 degrees C. Several alpha-keto acids, pyruvate, alpha-ketobutyrate, oxaloacetate, and alpha-ketoglutarate, protect cells from the lethal action of the heat treatment in the absence of D-glucose and L-glutamine. L-Glucose and D-glutamine are without effect. Efforts to reverse lethal effects have not been successful.

Animals↗

An efficient synthesis of 3 alpha-hydroxy-5 alpha-pregna-9(11),16-diene-20-one.

3 alpha-Hydroxy-5 alpha-pregna-9(11),16-diene-20-one (6) was synthesized for the first time from the commercially available 16,17 alpha-epoxy-3 beta-hydroxy-5-pregnen-20-one(1) in several steps. The key step involves a remote chlorination reaction utilizing m-iodobenzoate group as a free-radical guide.

Chemical Phenomena↗

The effect of antifungal agents on pancreatic and gastric secretion in rats.

This study was designed to investigate the effects of griseofulvin, 5-fluorocytosine (5-FC), and amphotericin B on pancreatic and gastric secretion after the administration of a single large dose, or repeated small doses for 3 weeks, in male albino rats. The exocrine functions of the main digestive glands were only slightly affected by griseofulvin and were not affected by 5-FC. In contrast, a single large dose of amphotericin B caused a marked inhibition of exocrine functions of the main digestive glands. The rats treated with 5-FC lost body weight markedly during 2 weeks of administration.

Amphotericin B↗