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Biomedical subjects

K Kim

Publications and source records attributed to K Kim.

At least 541 records · Page 30Linked to original sources
PubMed1988

The isolation and purification of a specific "protector" protein which inhibits enzyme inactivation by a thiol/Fe(III)/O2 mixed-function oxidation system.

Mixed-function oxidation systems comprised of Fe3+, O2, and electron donors such as thiol compounds, ascorbate, NAD(P)H/NAD(P)H oxidase, and xanthine oxidase/hypoxanthine, catalyze the inactivation of many enzymes. This report describes the isolation and purification of a soluble protein from Saccharomyces cerevisiae, which specifically inhibits the inactivation of various enzymes by a nonenzymatic Fe3+/O2/thiol mixed-function oxidase system. When thiol is replaced with another electron donor (e.g. ascorbate), this specific protein no longer protects against iron (or copper)/O2-dependent radical-induced enzyme inactivation. Purification steps included a polyethylene glycol precipitation followed sequentially by a chromatography on DE52 and high pressure liquid chromatography on phenyl, DEAE, and gel-filtrated columns. The final gel filtration step yielded two protein peaks exhibiting protector activity and possessing a Mr of 500,000 and 90,000. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of these two fractions gave a single band at 27 kDa suggesting that these protein species simply represent different oligomeric structures. The protector protein did not possess catalase, glutathione peroxidase, superoxide dismutase, or iron chelation activities. Since the protection activity reported herein is specific for mixed-function oxidation systems containing thiols, we propose that the protector protein functions as a sulfur radical scavenger.

Antioxidants↗
PubMed1988

Familial hemophagocytic lymphohistiocytosis.

The cytologic features of familial hemophagocytic lymphohistiocytosis in two infant siblings were reviewed and compared to the histopathologic features in the same cases. The cytologic features of familial hemophagocytic lymphohistiocytosis in imprint smears from the spleen, lymph nodes, and liver were distinct, with proliferation of benign histiocytes engulfing erythrocytes and platelets. Hemophagocytic activity was more readily identifiable in imprint smears than in paraffin-embedded histologic sections. The differential diagnosis of histiocytic proliferative syndromes is also discussed.

Diagnosis, Differential↗
PubMed1988

Effect of chronic administration of progesterone on the naloxone-induced LHRH release from hypothalami of ovariectomized, estradiol-primed prepubertal rats.

To test the hypothesis that progesterone (P) administered in a high dose and for a long duration would influence in vitro LHRH release by naloxone, silastic capsules containing P (50 mg/ml) or vehicle were implanted sc in ovariectomized, estradiol-primed (OVX+E) prepubertal rats. Following a 48 hr exposure to P, rats were sacrificed and mediobasal hypothalamic (MBH) fragments were obtained. In addition, in other OVX+E primed rats, a single injection of P (1 mg) was given sc 6 hr prior to decapitation. Naloxone or control medium were infused into superfusion chambers containing MBH fragments derived from these animals for 2 hr following a 1 hr control period. Infusion of naloxone (1 x 10(-4) M) markedly stimulated in vitro LHRH release from MBH from rats pre-exposed to P for 48 hr, whereas it was unable to do so in other groups examined. These data clearly indicate that the ability of naloxone (1 x 10(-4) M) to stimulate LHRH release is dependent on the duration of P administration.

Animals↗
PubMed1988

Renal cytomembranous inclusions in idiopathic renal disease as predictive markers for the acquired immunodeficiency syndrome.

Tubuloreticular inclusions (TRI) and cylindrical confronting cisternae (CCC) are present in cells of patients with the acquired immunodeficiency syndrome (AIDS) and have also been detected in the kidneys of individuals with AIDS and heavy proteinuria. We examined renal biopsy tissue from 13 patients with proteinuria and/or renal insufficiency. At the time of biopsy, two of the patients had AIDS (group A), four had AIDS-related complex (ARC) (group B), and seven presented without any clinical signs or symptoms characteristic of AIDS or ARC. These seven had risk factors for AIDS, and systemic lupus erythematosus (SLE) was excluded in all. Abundant TRI were present in the renal endothelial and fibroblastic interstitial cells in all patients from group A and B and in four patients who had no evidence for AIDS or ARC at the time of biopsy (group C). These individuals were followed, and all developed AIDS within a period of 3 to 14 months. CCC were detected in two of two patients in group A, one of four in group B, and one of four in group C. TRI and CCC were not present in the renal tissue of the remaining three patients; they did not develop ARC or AIDS over a prolonged observation period. Our findings suggest that TRI and TRF are ultrastructural markers for human immunodeficiency virus (HIV) associated nephropathy and can be seen before AIDS has manifested itself. These structures may be of predictive value for the future development of AIDS in patients presenting with apparent idiopathic renal disease.

AIDS-Related Complex↗
PubMed1988

High-efficiency, one-step starch utilization by transformed Saccharomyces cells which secrete both yeast glucoamylase and mouse alpha-amylase.

Transformed, hybrid Saccharomyces strains capable of simultaneous secretion of glucoamylase and alpha-amylase have been produced. These strains could carry out direct, one-step assimilation of starch, with conversion efficiency greater than 93% during a 5-day growth period. One of the transformants converted 92.8% of available starch into reducing sugars in only 2 days. Glucoamylase secretion by these strains resulted from expression of one or more chromosomal STA genes derived from Saccharomyces diastaticus. The strains were transformed by a plasmid (pMS12) containing mouse salivary alpha-amylase cDNA in an expression vector containing yeast alcohol dehydrogenase promoter and a segment of yeast 2 micron plasmid. The major starch hydrolysis product produced by crude amylases found in culture broths was glucose, indicating that alpha-amylase and glucoamylase acted cooperatively.

Animals↗
PubMed1988

[Evaluation of transcatheter arterial embolization in terms of serum alpha-fetoprotein doubling time in hepatocellular carcinoma].

We measured alpha-fetoprotein doubling time (T2AFP) in 51 patients with hepatocellular carcinoma treated by transcatheter arterial embolization (TAE). We also studied vascular invasion and the survival rate, and looked for correlations. For six patients with T2AFP less than or equal to 30 days after TAE, the time until the finding of vascular invasion by ultrasonography and angiography was 8.5 +/- 3.9 months; for seven patients with T2AFP greater than or equal to 31 days after TAE, it was 17.6 +/- 5.2 months (p less than 0.01). Of 45 patients for whom T2AFP was measured after TAE, 9 were in group A with T2AFP greater than or equal to 61 days, 18 were in group B with an intermediate value, and 18 were in group C with T2AFP less than or equal to 30 days. The two-year survival rate after the first TAE was 55.6% in group A, 42.5% in group B, and 6.0% in group C. The longest survival period was 51 months in group A, 30 months in group B, and 28 months (patient still alive) in group C. In the 18 patients for whom T2AFP was measured before and after TAE, the T2AFP was markedly decreased after TAE in 7 (39%). The pattern of change in T2AFP after TAE was not clearly correlated with the decrease in AFP or the T2AFP value before TAE.

Carcinoma, Hepatocellular↗
PubMed1988

[Clinical application of microfibrillar collagen hemostat (Avitene) in neurosurgical field].

Microfibrillar collagen hemostat (Avitene) is a new absorbable hemostatic agent, of which mechanisms are adhesion to the bleeding site and platelet aggregation. Histopathological examinations revealed that Avitene was biocompatible with cerebral cortex in an animal experiments. Our previous studies indicated that Avitene is very effective and safe to use as a topical hemostatic agent during craniotomy in an experimental animal. Avitene was used as a topical hemostatic agent during craniotomy in 36 patients with intracranial organic lesions. Its effectiveness of hemostasis was revealed in 95%. This agent was especially useful to prevent oozing during craniotomy. Side effect of this agent was not reported in this study. Therefore, Avitene is very effective and safe to use as a topical hemostatic agent in the neurosurgical field.

Brain↗
PubMed1987

Identification of three stage-specific proteinases of Plasmodium falciparum.

We have identified and characterized three stage-specific proteinases of Plasmodium falciparum that are active at neutral pH. We analyzed ring-, trophozoite-, schizont-, and merozoite-stage parasites by gelatin substrate PAGE and characterized the identified proteinases with class-specific proteinase inhibitors. No proteinase activity was detected with rings. Trophozoites had a 28 kD proteinase that was inhibited by inhibitors of cysteine proteinases. Mature schizonts had a 35-40 kD proteinase that also was inhibited by cysteine proteinase inhibitors. Merozoite fractions had a 75 kD proteinase that was inhibited by serine proteinase inhibitors. The stage-specific activity of these proteinases and the correlation between the effects of proteinase inhibitors on the isolated enzymes with the effects of the inhibitors on whole parasites suggest potential critical functions for these proteinases in the life cycle of malaria parasites.

Animals↗
PubMed1987

Effects of dietary tryptophan levels on growth, feed/gain, carcass composition and liver glutamate dehydrogenase activity in rainbow trout (Salmo gairdneri).

1. The tryptophan requirement of rainbow trout (initial body wt, 13 g) was estimated by feeding diets containing varied levels of tryptophan from 0.06 to 0.5% of diet for 6 weeks. 2. The estimated tryptophan requirement was 0.20-0.25 (0.57-0.71)% of diet (dietary proteins). 3. Nitrogen retention increased and feed/gain decreased with dietary tryptophan levels up to 0.14%, but no further effect was observed at levels above 0.14%. 4. Carcass protein content gradually increased and lipid and ash contents decreased with increasing dietary tryptophan levels. 5. Dietary tryptophan levels did not affect hepatosomatic index or liver glutamate dehydrogenase activity.

Animals↗
PubMed1987

Infection potential of nondisposable pressure transducers prepared prior to use.

This study was designed to examine whether pressure transducer systems prepared hours or days before actual use represent an infection potential. Twenty-one nondisposable transducers assembled with sterile plastic disposable domes and extension tubing were utilized. The systems were prefilled with heparinized flush solution (2 U sodium heparin per ml normal saline). Flush solution samples were cultured from the distal end of the equipment immediately after set-up (time 0) and 24, 48, and 72 h after set-up in all 21 transducers. In 11 of 21 transducers, cultures were also taken at 168 h (1 wk) and 336 h (2 wk) after set-up. Out of the total 106 cultures, only two showed growth, both of which proved to be external skin or mouth contaminants. Binomial distribution testing indicated that if a .05 probability level was used, the chance was 1.3% that one or more transducers in 100 could become contaminated by 72 h. Using the same statistical analyses for the 66 cultures involving the 11 transducers cultured for 2 wk, the chance of contamination in 100 cultures is 2.7% at 2 wk. We conclude from these data that nondisposable transducer systems, when preassembled using standard aseptic precautions and sterile disposable plastics, show no evidence of significant contamination when allowed to stand in readiness after assembly but not connected to a patient. We feel it is safe to preassemble transducers for at least a 72-h period before use. Longer intervals from set-up to use may also be justified.

Equipment Contamination↗