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Biomedical subjects

M K Kim

Publications and source records attributed to M K Kim.

At least 19 recordsLinked to original sources
PubMed2006

Birth of viable female dogs produced by somatic cell nuclear transfer.

Since the only viable cloned offspring born in dogs was a male, the purpose of the present study was to produce female puppies by somatic cell nuclear transfer (SCNT). Adult ear fibroblasts from a 2-month-old female Afghan hound were isolated and used as donor cells. In vivo-matured canine oocytes surgically collected (approximately 72h after ovulation) from the oviducts of 23 donors were used for SCNT. After removal of the cumulus cells, oocytes were enucleated, microinjected, fused with a donor cell, and activated. A total of 167 reconstructed SCNT embryos were surgically transferred (Day 0) into the oviducts of 12 recipient bitches (average 13.9 embryos/recipient, range 6-22) with spontaneous, synchronous estrous cycles. Three pregnancies were detected by ultrasonography on Day 23, maintained to term, and three healthy female puppies (520, 460, and 520g), were delivered by Caesarean section on Day 60. These puppies were phenotypically and genotypically identical to the cell donor. In conclusion, we have provided the first demonstration that female dogs can be produced by nuclear transfer of ear fibroblasts into enucleated canine oocytes.

Animals↗
PubMed2006

Enhanced production of Scenedesmus spp. (green microalgae) using a new medium containing fermented swine wastewater.

Fermented swine urine (3%) (v/v) was added to a control medium (CT), named KEP I, and an aquatic microalgal culture (10% Bold's Basal Medium) for growing mixed Scenedesmus species. During a two-month period, the KEP I medium effected, the delayed onset of the stationary phase of cell division in a batch culture. After 31 days, of culturing, the growth rate (3-fold), dry weight (2.6-fold) and amino acid levels (2.7-fold), and secondary metabolites including chlorophyll a (2.1-fold), astaxanthin (2.8-fold), lutein (2.7-fold) and alpha (greater than 30-fold) and beta-carotene (greater than 5-fold) increased a greater degree in Scenedesmus grown in KEP I medium than in CT medium. Total lipids were much less in cells grown in KEP I than those grown in CT. An increased quantum yield of photosystem II of the aquatic microalgae. The KEP I medium should improve the cost efficiency of industrial mass batch cultures for CO(2) sequestration, bioremediation, phytonutrients, agricultural fertilizers, and microalgal stock for the species preservation of aquaculture strains for use in young fish feed. It may also serve to attenuate negative environmental impact via the recycling of animal wastewater.

Animals↗
PubMed2006

Short-term effect of intracameral triamcinolone acetonide on corneal endothelium using the rabbit model.

PURPOSE: To investigate the effect of intracameral injection of triamcinolone acetonide on the corneal endothelium in rabbit eyes. METHODS: Triamcinolone acetonide (40 mg/ml, 0.2 cm3) after filtering and resuspension in balanced salt solution (BSS) was injected intracamerally for 3 min into 10 rabbit eyes and irrigated with 5 cm(3) of BSS. Triamcinolone without resuspension and BSS were injected, respectively, into five rabbit eyes. Endothelial toxicity was evaluated and compared by measurements of endothelial cell counts and central corneal thickness. The endothelial viability was determined using vital staining with alizarin red and trypan blue at 2 h after injection. The scanning electron microscopy (SEM) was performed in one cornea from each group. RESULTS: Endothelial cell counts and central corneal thickness following intracameral injection of triamcinolone acetonide did not significantly change when compared to controls. The mean percentage of viable endothelial cells was 99.50, 99.52, and 99.49% in the resuspended triamcinolone group, triamcinolone without resuspension group, and BSS group, respectively (P=0.46, Kruskall-Wallis test). But SEM showed reduced microvilli of endothelial surface in an eye of the triamcinolone without resuspension group. CONCLUSIONS: The intracameral injection of triamcinolone acetonide did not induce a significant visible change of endothelium in rabbit eyes. However, ultrastructural villi changes observed suggest a possibility of microstructural damages in endothelium with triamcinolone acetonide injection when used without filtering and resuspension.

Animals↗
PubMed2006

Endothelial progenitor cells in pterygium pathogenesis.

PURPOSE: The pathogenesis of pterygium is not well known, and controversy exists about the cell origins and the nature of initial trigger required for its development. We investigated whether endothelial progenitor cells (EPCs) are involved in pathogenesis of pterygium and the mechanism underlying the selective recruitment of EPCs during this process. METHODS: We studied 13 normal controls and 28 pterygium patients (primary (n=15), recurrent (n=13)). Substance-P, vascular endothelial growth factor (VEGF), and stem cell factor (SCF) were measured in plasma and tears using ELISA, and circulating CD34(+) and c-kit(+) mononuclear cells (MNCs) by flow cytometry. Anterior segment fluorescein angiography (FAG) was performed to evaluate hypoxic conditions in the early stage of pterygium. Surgically removed pterygial tissues were analyzed immunohistochemically using the progenitor cell markers, CD34, c-kit, VEGFR-1, and VEGFR-2. RESULTS: Anterior segment FAG findings showed an increase in non-perfusion areas and attenuated vessels in the nasal limbus during early-stage pterygium. Circulating CD34(+) MNCs and c-kit(+) MNCs were increased in pterygium groups compared with normal controls. Systemic and local cytokines including SP, VEGF, and SCF in pterygium groups were also elevated and showed positive correlations with CD34(+) and c-kit(+) MNC numbers. Immunohistochemical analysis of pterygium showed strong progenitor cell marker immunoreactivities. CONCLUSIONS: EPCs might be involved in pterygium development, and ocular hypoxia triggers this neovascularization by recruiting EPCs derived from the bone marrow via the production of systemic and local cytokines.

Age Distribution↗
PubMed2006

An orally active cathepsin K inhibitor, furan-2-carboxylic acid, 1-{1-[4-fluoro-2-(2-oxo-pyrrolidin-1-yl)-phenyl]-3-oxo-piperidin-4-ylcarbamoyl}-cyclohexyl)-amide (OST-4077), inhibits osteoclast activity in vitro and bone loss in ovariectomized rats.

Human cathepsin K, a cysteine proteinase of the papain family, has been recognized as a potential drug target for the treatment of osteoporosis. The predominant expression of cathepsin K in osteoclasts has rendered the enzyme into a major target for the development of novel antiresorptive drugs. Now, we report the pharmacological properties of OST-4077 [furan-2-carboxylic acid (1-{1-[4-fluoro-2-(2-oxo-pyrrolidin-1-yl)-phenyl]-3-oxo-piperidin-4-ylcarbamoyl}-cyclohexyl)-amide] as a novel selective cathepsin K inhibitor. Human and rat cathepsin K were inhibited in vitro by OST-4077 with the IC50 values of 11 and 427 nM, respectively. OST-4077 suppressed bone resorption induced by rabbit osteoclasts (IC50, 37 nM) but did not affect bone mineralization or cellular alkaline phosphatase activity in MC3T3-E1 cells. Parathyroid hormone-induced bone resorption was inhibited in a dose-dependent manner in thyroparathyroidectomized rats gavaged with a single dose of OST-4077 (ED50, 69 mg/kg). When given orally twice daily for 4 weeks to 3-month-old ovariectomized (OVX) rats, OST-4077 dose-dependently prevented bone loss, as monitored by bone densitometry, ash content, and urinary excretion of deoxypyridinoline. No change in serum osteocalcin in the OVX rats by OST-4077 suggested that bone formation might not be affected by the agent. In summary, OST-4077 selectively inhibited bone resorbing activities of osteoclasts and prevented bone loss induced by estrogen deficiency but did not affect bone formation. OST-4077, an orally active selective human cathepsin K inhibitor, may have the therapeutic potential for the treatment of diseases characterized by excessive bone loss including osteoporosis.

Alkaline Phosphatase↗
PubMed2006

Isolation and characterization of outer root sheath melanocytes of human hair follicles.

BACKGROUND: Outer root sheath melanocytes (ORSM) are not yet routinely cultured and their biology is not known in detail because of their relatively low numbers in the hair follicle and their limited proliferative capacity in in vitro culture in routine media. OBJECTIVES: To develop a method for culturing ORSM more easily and to investigate the length of telomeres and antigenic characteristics of ORSM compared with epidermal melanocytes (EM). METHODS: Hair follicles were obtained from three Korean individuals during hair transplantation surgery. Single-cell suspensions of the outer root sheath were made and cultured in melanocyte growth medium with stem cell factor. After 21 days, second-passage outer root sheath keratinocytes (ORSK) (2 x 10(4) mL(-1) MGM) were added into the culture plates. We studied the proliferation pattern, morphological and antigenic characteristics of ORSM for each passage of cultured cells, and observed ORSM telomere length. RESULTS: We established an ORSM culture method using ORSK. Two morphologically different ORSM types were obtained in the primary cultures. At the end of primary culture, ORSM appeared as whitish-cream pellets. The proliferation pattern of ORSM showed a sigmoidal shape, the accumulated numbers of population doublings showed a plateau after approximately 5 months, and senescence occurred at approximately 33 +/- 5 accumulated population doublings. The length of ORSM telomeres continued to shorten as the cells proliferated. In contrast, EM showed a marked proliferation from the early proliferation period which formed a plateau pattern towards the later period, and the number of accumulated population doublings was estimated to be 18 +/- 5 after 2 months. ORSM in the primary culture reacted variably with l-dihydroxyphenylalanine (DOPA): some cells were DOPA negative, some DOPA positive. There were some different antigenic expressions of microphthalmia-associated transcription factor (MITF) showing cytoplasmic expression in ORSM and nuclear expression in EM. By nuclear extraction and Western blotting, we showed that MITF expression of ORSM was marked in the cytoplasm and minimal in the nucleus. Antigenic expression of MITF and Bcl-2 gradually decreased with increasing passage number, whereas tyrosinase-related protein-1 expression did not change. CONCLUSIONS: Culture of ORSM requires ORSK or ORSK-related factors; ORSM have greater proliferation potential and show different MITF antigenic expression compared with EM; and the length of ORSM telomeres shortens with repeated proliferation.

Adult↗
PubMed2006

Enhanced biodegradation of diesel oil by a newly identified Rhodococcus baikonurensis EN3 in the presence of mycolic acid.

AIMS: The aim of the present study was to isolate and characterize a bacterium, strain EN3, capable of using diesel oil as a major carbon and energy source, and to analyse the enhancement of diesel oil degradation by this organism using synthetic mycolic acid (2-hexyl-3-hydroxyldecanoic acid). METHOD AND RESULTS: An actinomycete with the ability to degrade diesel oil was isolated from oil contaminated soil and characterized. The strain had phenotypic properties consistent with its classification in the genus Rhodococcus showing a 16S rRNA gene similarity of 99.7% with Rhodococcus baikonurensis DSM 44587(T). The ability of the characterized strain to degrade diesel oil at various concentrations (1000, 5000, 10 000 and 20 000 mg l(-1)) was determined. The effect of synthetic mycolic acid on the biodegradation of diesel oil was investigated at the 20 000 mg l(-1) concentration; the surfactant was added to the flask cultures at three different concentrations (10, 50 and 100 mg l(-1)) and degradation followed over 7 days. Enhanced degradation was found at all three concentrations of the surfactant. In addition, the enhancement of diesel oil degradation by other surfactants was observed. CONCLUSIONS: The synthetic mycolic acid has potential for the remediation of petroleum-contaminated sites from both an economic and applied perspective as it can stimulate biodegradation at low concentrations. SIGNIFICANCE AND IMPACT OF THE STUDY: This study showed that the synthesized mycolic acid can be used for potential applications in the bioremediation industries, for example, in oil spill clean-up, diesel fuel remediation and biostimulation.

Biodegradation, Environmental↗
PubMed2006

Influence of phenol on the biodegradation of pyridine by freely suspended and immobilized Pseudomonas putida MK1.

AIMS: To study the effect of co-contaminants (phenol) on the biodegradation of pyridine by freely suspended and calcium alginate immobilized bacteria. METHODS AND RESULTS: Varying concentrations of phenol were added to free and calcium alginate immobilized Pseudomonas putida MK1 (KCTC 12283) to examine the effect of this pollutant on pyridine degradation. When the concentration of phenol reached 0.38 g l(-1), pyridine degradation by freely suspended bacteria was inhibited. The increased inhibition with the higher phenol levels was apparent in increased lag times. Pyridine degradation was essentially completely inhibited at 0.5 g l(-1) phenol. However, immobilized cells showed tolerance against 0.5 g l(-1) phenol and pyridine degradation by immobilized cell could be achieved. CONCLUSIONS: This works shows that calcium alginate immobilization of microbial cells can effectively increase the tolerance of P. putida MK1 to phenol and results in increased degradation of pyridine. SIGNIFICANCE AND IMPACT OF THE STUDY: Treatment of wastewater stream can be negatively affected by the presence of co-pollutants. This work demonstrates the potential of calcium alginate immobilization of microbes to protect cells against compound toxicity resulting in an increase in pollutant degradation.

Anti-Bacterial Agents↗
PubMed2006

Effects of surface charge, micro-bubble size and particle size on removal efficiency of electro-flotation.

Flotation is a water treatment alternative to sedimentation, and uses small bubbles to remove low-density particles from potable water and wastewater. The effect of zeta potential, bubble size and particle size on removal efficiency of the electro-flotation process was investigated because previous model-simulations indicated that these attributes are critical for high collision efficiency between micro-bubbles and particles. Solutions containing Al3+ as the metal ion were subjected to various conditions. The zeta potentials of bubbles and particles were similar under identical conditions, and their charges were influenced by metal ion concentration and pH. Maximum removal efficiency was 98 and 12% in the presence and absence of flocculation, respectively. Removal efficiency was higher when particle size was similar to bubble size. These results agree with modelling simulations and indicate that collision efficiency is greater when the zeta potential of one is negative and that of the other is positive and when their sizes are similar.

Aluminum Chloride↗
PubMed2006

Intracranial xanthoma: long-term follow-up MR findings.

SUMMARY: We report the serial MR findings and histologic features of intracerebral xanthoma in a patient with hyperlipidemia. MR imaging revealed nodule formations with variable degrees of edema and enhancement in the perivascular spaces. In some lesions, high-signal-intensity foci were observed on unenhanced T1-weighted images, which suggest lipid contents of the lesion.

Basal Ganglia↗
PubMed2005

Release of ciprofloxacin from chondroitin 6-sulfate-graft-poloxamer hydrogel in vitro for ophthalmic drug delivery.

The system was designed to use Poloxamer as a vehicle for ophthalmic drug delivery using in situ gel formation property. To enhance the wound healing and cell adhesion as well as transparency of Poloxamer hydrogel, chondroitin 6-sulfate (C6S) was introduced into Poloxamer. For this purpose, mono amine-terminated Poloxamer (MATP), which was end-capped with ethylene amine group only in one side of terminal hydroxyl groups of Poloxamer, was synthesized. Subsequently, C6S-graft-Poloxamer copolymer (C6S-g-Poloxamer) was prepared by reaction between the amine groups of MATP and carboxyl groups of C6S in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carboimide (EDC). The coupling of MATP with C6S was clarified by 1H-NMR and FT-IR spectroscopy. The gelation temperature of graft copolymers was determined by measuring the temperature at which immobility of the meniscus in each solution was first noted. Release behavior of ciprofloxacin from C6S-g-Poloxamer hydrogel in vitro was investigated as a function of C6S content in the graft copolymer by a spectrophotometric assay at 287 nm using an UV spectrophotometer. Differences in the adhesion and morphology of human lens cell between Poloxamer- and C6S-g-Poloxamer-coated surfaces were also investigated. The gelation temperatures of C6S-g-Poloxamer copolymers were lowered with increasing of the concentration of the copolymer and decreasing of C6S content. The release of ciprofloxacin from the graft copolymer was sustained compared with Poloxamer itself and decreased with increasing the content of C6S in the copolymer due to the in situ gel formation of the copolymer and viscous properties of C6S. Human lens cells (B3) adhered to C6S-g-Poloxamer-coated surface were observed as transformed shapes after 2 days. The bioadhesive and thermally gelling of these graft copolymers will be expected to be an excellent drug carrier for the prolonged delivery to surface of the eye.

Cells, Cultured↗
PubMed2004

Impact of IL-1 receptor antagonist gene polymorphism on schizophrenia and bipolar disorder.

OBJECTIVES: Variable levels of cytokines were observed in patients with schizophrenia and bipolar disorder, and an especially high level of interleukin-1 (IL-1) was detected in schizophrenia patients. It is known that IL-1 receptor antagonist (IL-1RA) binds to IL-1 receptors and inhibits the receptor binding of IL-1alpha and IL-1beta. METHODS: In this study, the association between the variable number of tandem repeats polymorphism of the IL-1RA gene and schizophrenia (n=269) and bipolar disorder (n=83) was investigated. RESULTS: The genotype distribution and allele frequency were significantly different between schizophrenic patients and the control group (P<0.05); however, there were no prominent differences between bipolar patients and the control group. The carriage rate for the IL1RN*2 allele was associated with higher risk of schizophrenia (odds ratio=2.24). CONCLUSIONS: This study indicates that IL-1RA could be a candidate gene for susceptibility to schizophrenia.

Adult↗