Biomedical subjects

H W Kim

Publications and source records attributed to H W Kim.

At least 55 records · Page 3Linked to original sources

PubMed2000

Dietary lutein stimulates immune response in the canine.

The possible immuno-modulatory action of dietary lutein in dogs is not known. Female Beagle dogs (17-18-month old; 11.4+/-0.4kg body weight) were supplemented daily with 0, 5, 10 or 20mg lutein for 12 weeks. Delayed-type hypersensitivity (DTH) response to saline, phytohemagglutinin (PHA) and a polyvalent vaccine was assessed on Weeks 0, 6 and 12. Blood was sampled on Weeks 0, 2, 4, 8 and 12 to assess (1) lymphocyte proliferative response to PHA, concanavalin A (Con A), and pokeweed mitogen (PWM), (2) changes in peripheral blood mononuclear cell (PBMC) populations, (3) interleukin-2 (IL-2) production and (4) IgG and IgM production. After the completion of 12-week study, we continued to collect the blood weekly up to 17 weeks to evaluate the changes in immunoglobulin production upon first and second antigenic challenges on Weeks 13 and 15. Plasma lutein+zeaxanthin was undetectable in unsupplemented dogs but concentrations increased (P<0.05) rapidly on Week 2 in lutein-supplemented dogs. Thereafter, concentrations generally continued to increase in dose-dependent manner, albeit at a much slower rate. Dogs fed lutein had heightened DTH response to PHA and vaccine by Week 6. Dietary lutein increased (P<0.05) lymphocyte proliferative response to all three mitogens and increased the percentages of cells expressing CD5, CD4, CD8 and major histocompatibility complex class II (MHC II) molecules. The production of IgG increased (P<0.05) in lutein-fed dogs after the second antigenic challenge. Lutein did not influence the expression of CD21 lymphocyte marker, plasma IgM or IL-2 production. Therefore, dietary lutein stimulated both cell-mediated and humoral immune responses in the domestic canine.

Adjuvants, Immunologic↗

PubMed2000

The new genotypic human calicivirus isolated in Seoul.

A new type of human calicivirus (HuCV) showing the classic cup-shaped surface morphology was identified in the stool sample from a child with symptoms of acute gastroenteritis in Seoul, Korea (SK virus). Genomic RNA was extracted directly from the stool sample, and the nucleotide sequence of 3.2 kb of the 3' end of SK virus was determined from cDNA. This region spanned sequences from the RNA-dependent RNA polymerase (RDRP) region in the open reading frame 1 (ORF1) to the 3' poly A tail. The non-structural and capsid protein coding sequences were fused in a single ORF as observed in Manchester type (Genogroup III). However, ORF2 of Manchester virus was missing in SK virus. In RDRP region, SK virus showed amino acid and nucleotide identities of 74-75% and 68-69% respectively, with those of Manchester virus, while showed 34-46% and 55-60% identities respectively with those of other human caliciviruses. However, capsid protein of SK virus showed a partial (29-46%) amino acid identity with those of other caliciviruses including Manchester type. The closest resemblance in amino acid (97-99%) and nucleotide sequence (85-86%) identities were found in RDRP region with Vanderbijlpark and Pretoria isolates recently found in South Africa. These results suggest that SK virus together with Vanderbijlpark and Pretoria isolates belong to a new type different from Manchester virus.

Amino Acid Sequence↗

PubMed2000

Modulation of humoral and cell-mediated immune responses by dietary lutein in cats.

The immuno-modulatory role of dietary lutein in domestic cats is unknown. Female Tabby cats (10-month old; n=56) were supplemented daily for 12 weeks with 0, 1, 5 or 10mg lutein. Blood was collected on Weeks 0, 2, 4, 8 and 12 to assess the following: (1) mitogen-induced peripheral blood mononuclear cells (PBMCs) proliferation, (2) changes in PBMC subpopulations, (3) interleukin-2 (IL-2) production and (4) plasma immunoglobulin (Ig)G production. In addition, delayed-type hypersensitivity (DTH) response to concanavalin A (Con A) or a polyvalent vaccine was performed on Weeks 0, 6 and 12. Dietary lutein increased plasma lutein concentrations in a dose-dependent manner (p<0.001) and concentrations had not reached steady state after 12 weeks of feeding in cats given 5 or 10mg lutein. Concentrations of plasma retinol and alpha-tocopherol were not influenced by diet. The DTH response to vaccine but not to Con A increased (p<0.05) in a dose-dependent manner on Week 6. Compared to control, cats fed lutein also showed enhanced Con A- and pokeweed mitogen-stimulated PBMCs proliferation. Dietary lutein also increased the percentages of CD4+ and CD21+ lymphocytes on Week 12 but had no significant effect on pan T, CD8 and MHC class II markers. Plasma IgG was higher (p<0.05) in cats fed 10mg lutein on Weeks 8 and 12. These results support the immuno-modulatory action of lutein in domestic cats.

Animals↗

PubMed2000

Mycelial protoplast isolation and regeneration of Lentinus lepideus.

Generation of fungal protoplast is essential for fusion and transformation systems. Protoplast fusion offers great potential for the improvement of industrially important microorganisms. To establish conditions for the protoplast isolation and regeneration of the mycelia of Lentinus lepideus, various enzymes and osmotic stabilizers were examined. To investigate suitable medium for the culture of L. lepideus, the mycelia were grown in ten different media at 28 degrees C for 10 days. Among them potato dextrose agar (PDA) medium was found to be the best for colony growth. When Novozym 234, cellulase and beta-glucuronidase were added to the mycelia in combination or alone, Novozym 234 alone at the concentration of 10 mg/ml was the most effective for the protoplast yield. Purified spherical protoplasts of the mycelia were osmotically hypersensitive and further incubation of the mycelia with the lytic enzyme resulted in the older parts of the hyphae swollen. When we applied various osmotic stabilizers at the fixed concentration of 0.6 M on the protoplasts, the yields of protoplasts were increased until 4-hr incubation. However application of sucrose or MgSO4 led to further protection of protoplasts after that time and reached a plateau on 5- and 7-hr incubations, respectively. The suitable incubation time and optimal pH with the lytic enzyme for the maximum release of protoplasts were 6 hrs of incubation and pH 5, respectively. When we examined various osmotic stabilizers for the regeneration of the protoplast, the complete medium containing 0.6 M sucrose induced highest hyphal growth with regeneration frequency of 3.28%.

Cell Fusion↗

PubMed2000

A standardized gating technique for the generation of flow cytometry data for normal canine and normal feline blood lymphocytes.

Flow cytometry is becoming a commonly used technique to characterize a variety of cells. It provides a powerful application to rapidly determine the relative percentages of T-lymphocyte subsets and B-lymphocytes. The effectiveness of its application, however, is dependent on standardization, especially in a clinical setting. Application of flow cytometry to veterinary diagnostics has been limited by the unavailability of reagents and by the unstandardized characterization of normal values using antibodies not commercially available, but typically provided through the generosity of other researchers. This paper presents a standardized gating protocol, and average values and ranges observed for normal canine and feline blood lymphocytes using commercially available antibodies to cell surface markers for CD5, CD3, CD4, CD8, MHC II, and B lymphocytes. The averages for these markers on gated lymphocytes were as follows: Canine CD5 83.3%, Canine CD4 45.0%, Canine CD8 28.8%, Canine MHC II 98.0%, Canine B Cell 12.9%, Canine CD4/CD8 ratio 1.87, Feline T lymphocytes 77.3%, Feline CD4 44.5%, Feline CD8 25.7%, Feline B Cell 24.1%, Feline CD4/CD8 Ratio 1.75. Normal values were also established for a mixed breed group of dogs, and old versus young dogs. This information will provide researchers and clinicians with a standardized protocol for gating, which establishes a basis for comparison between techniques, and a measure of phenotypic percentages for flow cytometry in normal dogs and cats based on this standardization and commercially available antibodies.

Age Factors↗

PubMed2000

Ionomycin restores taurine transporter activity in cyclosporin-A treated macrophages.

Taurine is accumulated at high concentrations in various tissues. The taurine transporter (TAUT) is responsible for the transportation of taurine in the cell. The transporter is affected by various stimuli to maintain cell volume. Macrophage cell volume varies in its activated states. In our experiment, it was found that the murine macrophage cell line, RAW264.7, expressed TAUT protein in its membrane. Its transporting activities could be blocked by beta-amino acid such as beta-alanine, but not by alpha-amino acids in this cell line, when assessed in RAW264.7 cells under the influence of immunosuppressive reagents, the activity of the TAUT was decreased by treatment with rapamycin (RM) or cyclosporin A (CSA). However, when ionomycin (IM) was added to this system, TAUT activity was recovered only in CSA-treated cells, in a concentration-dependent manner, in order to inhibit voltage gated Ca2+ channels, calmidazolium was added to the RAW264.7 cell line. Treatment of the cells with calmidazolium completely blocked TAUT. Furthermore, addition of IM to this system resulted in recovery the activity of TAUT again. When we added phorbol myristyl acetate (PMA) to the cell line, secretion of nitric oxide (NO) was increased 4-fold and the TAUT activity was decreased 5-fold. However, the addition of N-nitro L-arginine methyl ester (L-NAME), an inducible NO synthase (iNOS) inhibitor, to the PMA-treated cells induced recovery of TAUT activity. These results showed that the activity of TAUT was sensitive to both the intracellular concentrations of Ca2+ and NO.

Animals↗

PubMed2000

Measurement of fidelity in psychiatric rehabilitation.

Until recently, most psychiatric rehabilitation models have been poorly defined and few have had systematic methods for measuring their implementation. We review the historical roots for the development of fidelity measures and describe recent applications in both research and practice.

Humans↗

PubMed2000

The effects of isolated lipoproteins and triglyceride, combined oxidized low density lipoprotein (LDL) plus triglyceride, and combined oxidized LDL plus high density lipoprotein on the contractile and relaxation response of rabbit cavernous smooth muscle.

The aim of this study was to investigate the effects of isolated lipoproteins and triglyceride (TG), and the effects of combined oxidized low density lipoprotein (LDL) plus TG and the combined oxidized LDL plus high density lipoprotein (HDL) on the contractility and relaxation response of rabbit cavernous smooth muscle. Cavernous muscle strips from New Zealand White rabbits were studied in organ chambers for isometric tension measurement. The strips were exposed to HDL, LDL, oxidized LDL, TG, combined oxidized LDL plus TG and combined oxidized LDL plus HDL for 30 min. Both HDL and LDL did not affect contraction and relaxation responses of the cavernous muscles. The oxidized LDL did not affect norepinephrine (NE)-induced contractility of the strips, but significantly (p < 0.05) decreased the relaxation response to endothelium-dependent agonist, acetylcholine (Ach). Non-specific NO synthase inhibitor (L-NAME) completely inhibited the relaxation response to Ach, and L-arginine partially improved the diminished relaxation. TG did not significantly change the relaxation responses to Ach, but decreased the contractility of cavernous muscle to NE. Neither the combined oxidized LDL plus TG nor oxidized LDL plus HDL had significant synergistic or detoxication effects on the contractility and relaxation responses. In conclusion, oxidized LDL may have acute toxic effects on the endothelium-dependent, NO-mediated relaxation, but not on the contractility, of rabbit cavernous smooth muscle. TG may decrease contractility of the cavernous muscle. There may be neither synergistic nor detoxication effects on the contractility and relaxation response when TG or HDL is added to the oxidized LDL.

Animals↗

PubMed2000

General pharmacology studies on beta-domain deleted recombinant factor VIII.

beta-Domain deleted recombinant factor VIII (GC-rAHF), newly developed by Korea Green Cross Co., is a novel therapeutic for hemophiliacs and is currently under clinical evaluation. The general pharmacological properties of this drug were evaluated using mice, rats, guinea pigs and rabbits. Intravenous doses of 5 to 500 IU/kg were assayed in several tests to analyze their effects in vivo on various systems. The effect of the substance under study was also tested in vitro on isolated guinea pig ileum preparations at final concentrations of 5 to 50 IU/kg. The result of this study showed that GC-rAHF did not affect general behavior in the Irwin test. Similarly the drug was not found to affect neither normal body temperature nor the spontaneous activity in mice. In addition, it was not found to induce pharmacologically significant alterations of the cardiovascular and respiratory parameters in rats. No effects were observed either in the pentobarbital sodium-induced sleep-induction time and duration, in writhing test or in the test of pentetrazole-induced convulsion. Finally, the tested drug did not modify the gastrointestinal motility, acetylcholine or histamine-induced contraction of the isolated guinea pig ileum, nor gastric secretion. The results demonstrated that GC-rAHF has no effects on the central nervous, cardiovascular, respiratory and digestive systems in the doses of 5, 50 and 500 IU/kg in vivo and 5, 10, 50 and 100 IU/kg in vitro.

Animals↗

PubMed2000

Pharmacodynamic characterization of hemoglobin-induced vasoactivity in isolated rat thoracic aorta.

The origin and mechanism of vasocontraction observed after vascular exposure to acellular Hbs remain controversial. To help resolve the underlying mechanism, we characterized Hb-induced vasoactivities in terms of Hb purity, heme iron oxidation state, and ligand and pharmacodynamic properties. Isolated rat thoracic aortic rings with intact endothelium were suspended in oxygenated Krebs buffer, and isometric tension responses to various test Hb preparations were measured. In norepinephrine tone-enhanced aortic rings, both crude and purified Hbs exhibited similar dose-response characteristics; stroma-free Hb and HbA0, two Hb preparations with disparate purity, were equally potent in inducing vessel ring contraction. Purified Hb preparations significantly attenuated vasodilatory potency of both acetylcholine, an endothelium-dependent NO generator, and glyceryl trinitrate, an endothelium-independent NO generator. With the exception of nitrosylated Hb, ferrous Hbs, oxy Hb, and carbon monoxy Hb elicited contraction, whereas ferric derivatives, met Hb, and cyanomet Hb did not. In addition, NEM-Hb, an Hb with blocked cysteine residues, did not notably attenuate Hb vasoactivity. These results indicate that Hb itself is directly responsible for inducing contraction in the rat thoracic aortic rings. A primary mechanism for the Hb-induced vasoactivity appears to be heme iron inactivation of endothelium-derived NO. Nonheme interaction with endothelial NO does not appear to play a prominent role in this vascular model. In conclusion, Hb elicits dose-dependent contraction in isolated rat thoracic aorta with intact endothelium. Vasoactivity of Hbs, however, could greatly vary with heme iron oxidation state, nature of heme ligand, and model vessels used in the evaluation.

Animals↗

PubMed2000

Dietary beta-carotene stimulates cell-mediated and humoral immune response in dogs.

The role of beta-carotene on immune response in domestic dogs is not known. Female Beagle dogs were fed 0, 2, 20 or 50 mg beta-carotene/d; blood was sampled at wk 0, 1, 2, 4 and 8 for analysis of the following: lymphoproliferation, leukocyte subpopulations and concentrations of interleukin-2 (IL-2), immunoglobulin (Ig)G and IgM. Delayed-type hypersensitivity (DTH) response was assessed at wk 0, 3 and 7. beta-Carotene supplementation increased plasma beta-carotene concentrations in a dose-dependent manner. Compared with unsupplemented dogs, those fed 20 or 50 mg of beta-carotene had higher CD4+ cell numbers and CD4:CD8 ratio. However, there was no treatment difference in CD8+, CD21+ and major histocompatability complex (MHC) class II+ cells. Plasma IgG, but not IgM concentration was higher in dogs fed beta-carotene throughout the study period. The DTH response to phytohemagglutinin (PHA) and vaccine was heightened in beta-carotene-supplemented dogs. beta-Carotene feeding did not influence mitogen-induced lymphocyte proliferation or IL-2 production. Immune response was impaired in dogs classified as low beta-carotene absorbers compared with similar dogs fed the same amount of beta-carotene. Therefore, dietary beta-carotene heightened cell-mediated and humoral immune responses in dogs.

Animals↗

PubMed2000

19F NMR investigation of F(1)-ATPase of Escherichia coli using fluorotryptophan labeling.

Growth of Escherichia coli in the presence of glyphosate, an inhibitor of aromatic amino acid biosynthesis, has permitted the production of proton-dislocating ATPase that is specifically labeled with 5-fluorotryptophan. Five sets of (19)F resonances could be assigned to each tryptophan residue by lauryldimethylamine oxide and carboxypeptidase treatment. On labeling with 4-chloro-7-nitro-benzofurazan, the label attached to b155Lys, which is known to be in the catalytic site, which caused one of the residues, b108Trp, to become nonequivalent. (19)F NMR spectroscopic investigation of internally fluorotryptophan-labeled F(1)-ATPase will provide valuable information about the asymmetric nature of F(1)-ATPase and the conformational changes induced by ligand binding.

4-Chloro-7-nitrobenzofurazan↗

PubMed2000

Inhibition by (+)-persenone [corrected] A-related compounds of nitric oxide and superoxide generation from inflammatory leukocytes.

We have previously reported that persenone A, isolated from avocado fruit, is an effective inhibitor of both nitric oxide (NO) and superoxide (O2-) generation in cell culture systems. In this study, we have prepared four persenone A-related compounds and examined their inhibition of NO and O2- generation from inflammatory leukocytes. Some structural importance in persenone A to attenuate free radical generation is discussed.

Esters↗

PubMed2000

An avocado constituent, persenone A, suppresses expression of inducible forms of nitric oxide synthase and cyclooxygenase in macrophages, and hydrogen peroxide generation in mouse skin.

We investigated the suppressive effects of an avocado constituent, persenone A, on lipopolysaccharide- and interferon-y-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) in a mouse macrophage cell line RAW 264.7. Persenone A at concentration of 20 microM almost completely suppressed both iNOS and COX-2 protein expression. In mouse skin, double treatments with persenone A (810 nmol) significantly suppressed double 12-O-tetradecanoylphorbol-13-acetate (TPA, 8.1 nmol) application-induced hydrogen peroxide (H2O2) generation. Treatment with persenone A before the second TPA treatment was sufficient to inhibit H2O2 generation, while the first treatment was not. This study thus suggests that persenone A is a possible agent to prevent inflammation-associated diseases including cancer.

Animals↗

PubMed2000

Acetabular development in developmental dysplasia of the hip complicated by lateral growth disturbance of the capital femoral epiphysis.

BACKGROUND: Lateral growth disturbance of the capital femoral epiphysis is the most common type of physeal arrest complicating the treatment of developmental hip dysplasia. Although this type of physeal damage has been assumed to result in poor acetabular development, the natural history of dysplastic hips affected by this pattern of growth disturbance is still unclear. To investigate this issue, we evaluated acetabular development in a retrospective study of fifty-eight hips in forty-eight patients who had lateral physeal arrest after management of developmental hip dysplasia. METHODS: Of the fifty-eight hips, thirty-six were reduced closed and twenty-two were reduced open. The average age of the patients was twenty-two months (range, three to ninety-seven months) at the time of the reduction and twenty-one years (range, ten to fifty-five years) at the time of the latest follow-up evaluation. Hips rated as Severin class I (an excellent result) or II (a good result) were defined as having a satisfactory result, and those rated as Severin class III (a fair result) or IV (a poor result) were considered to have an unsatisfactory result. Specific femoral head changes were sought in the complete radiographic files on all hips. Various radiographic parameters of hip integrity, including the degree of lateral tilt of the capital femoral epiphysis, were measured over time, and comparisons were made between hips classified as satisfactory and those classified as unsatisfactory at four time-points: before the reduction, at two years after the reduction, at six to eight years of age, and at the time of the final follow-up. RESULTS: Lateral growth disturbance of the capital femoral epiphysis was first evident by an average of ten years of age (range, four to fourteen years of age). There was no consistent early pattern of changes in the epiphysis, physis, or metaphysis related to later development of valgus tilt of the epiphysis. Thirty-four hips (59 percent) were rated as satisfactory and twenty-four were rated as unsatisfactory at the latest follow-up evaluation. Hips classified as unsatisfactory exhibited poor acetabular development by an average age of seven years. The inclination of the epiphyseal plate became progressively more horizontal or even reversed over time; however, serial measurements of inclination were not significant predictors of Severin classification. CONCLUSIONS: Lateral growth disturbance of the capital femoral epiphysis is not necessarily associated with poor acetabular development, as when dysplasia does occur it is generally evident prior to the identification of the physeal arrest. It is important to monitor acetabular development after reduction rather than search for radiographic changes of physeal arrest, which are difficult to detect in young children.

Acetabulum↗

PubMed2000

Beta-carotene uptake and changes in ovarian steroids and uterine proteins during the estrous cycle in the canine.

The uptake of beta-carotene by reproductive tissues and the effects of beta-carotene on reproductive function in the dog are unknown. We studied the uptake of beta-carotene by blood, corpus luteum, and uterine endometrium and the role of dietary beta-carotene in influencing ovarian steroid and uterine protein production during the estrous cycle in the dog. Mature female Beagle dogs (n = 56) were fed diets containing 0, 2, 20, or 50 mg of beta-carotene daily for approximately 6 wk before estrus detection. Blood was sampled at regular intervals from estrus through d 45 after ovulation (d 0 = ovulation), when laparotomy was performed. The ovaries were obtained for the isolation of corpus luteum. The uterus was flushed with phosphate-buffered saline and the endometrium obtained by scraping. Beta-carotene was not detectable in plasma, corpus luteum, or endometrium of unsupplemented dogs. However, beta-carotene and alpha-carotene in plasma, corpus luteum, and uterine endometrium increased in a dose-dependent manner. Alpha-carotene made up a high percentage of total carotenoids even though the alpha-carotene content in the dietary source was very low. Dogs fed 50 mg of beta-carotene had significantly higher concentrations of plasma progesterone between d 12 and 26 compared with unsupplemented dogs. Dietary beta-carotene did not influence plasma estradiol-17beta and total uterine proteins. Therefore, beta-carotene is absorbed into plasma, corpus luteum, and uterine endometrium of dogs. Furthermore, dietary beta-carotene increased plasma progesterone concentrations during the estrous cycle. It is possible that dietary beta-carotene may improve reproductive function in the canine.

Animals↗

PubMed2000

An overview of cartilage tissue engineering.

Articular cartilage regeneration refers to the formation of new tissue that is indistinguishable from the native articular cartilage with respect to zonal organization, biochemical composition, and mechanical properties. Due to a limited capacity to repair cartilage, scar tissue frequently has a poorly organized structure and lacks the functional characteristics of normal cartilage. The degree of success to date achieved using a purely cell- or biological-based approach has been modest. Potentially the development of a hybrid strategy, whereby, chondrocytes or chondrogenic stem cells are combined with a matrix, making cartilage in vitro, which is then subsequently transplanted, offers a route towards a new successful treatment modality. The success of this approach depends upon the material being biocompatible, processable into a suitable three-dimensional structure and eventually biodegradable without harmful effects. In addition, the material should have a sufficient porosity to facilitate high cell loading and tissue ingrowth, and it should be able to support cell proliferation, differentiation, and function. The cell-polymer-bioreactor system provides a basis for studying the structural and functional properties of the cartilaginous matrix during its development, because tissue concentrations of glycosaminoglycan and collagen can be modulated by altering the conditions of tissue cultivation.

Animals↗

PubMed2000

Effect of intermittent administration of parathyroid hormone on fracture healing in ovariectomized rats.

The effects of intermittent administration of parathyroid hormone on fracture healing in ovariectomized rats were examined to evaluate its potential use as a therapeutic agent for osteoporotic fractures. Three months postovariectomy, bilateral tibial shaft fractures were induced and stabilized by intramedullary nailing with Kirschner wires. Saline, 17beta-estradiol (Sigma Chemical Corp, St Louis, Mo), or recombinant human parathyroid hormone (1-84) (Korean Green-Cross Pharm Corp, Seoul, Korea) was given once a day for 30 consecutive days during fracture healing. Fracture healing was assessed by morphometric and mechanical analysis of fracture callus. Intermittent parathyroid hormone administration increased the morphometric and mechanical parameters in a dose-dependent manner. A bone-resorption inhibiting agent, 17beta-estradiol did not offer advantage in terms of fracture healing in ovariectomized rats. Findings suggest intermittent parathyroid hormone administration may benefit osteoporosis and fracture.

Animals↗