Biomedical subjects

C K Kim

Publications and source records attributed to C K Kim.

At least 37 records · Page 2Linked to original sources

PubMed2004

Plutonium isotopes in seas around the Korean Peninsula.

239+240Pu concentrations and 240Pu/239Pu atom ratios in coastal seas adjacent to the Korean Peninsula were determined, during the period 1999 to 2002, to assess the current distribution and to identify sources of Pu isotopes. 239+240Pu concentrations in surface waters ranged from 3.1 to 22.3 mBq m(-3) with higher concentrations in winter than in summer. 239+240Pu concentrations in seawaters around the Korean Peninsula are greater than that in the western North Pacific. 240Pu/239Pu atom ratios ranged from 0.18 to 0.33 with an average value of 0.25+/-0.03, which is significantly higher than the global fallout average. The 240Pu/239Pu atom ratios of the 2000 m deep entire water column in the south western part of the East Sea (Sea of Japan) was comparable to that observed in waters near Bikini Atoll. The higher 240Pu/239Pu atom ratios than that of global fallout may be explained by the hypothesis that the earlier input signal of low 240Pu/239Pu atom ratio (0.18-0.19) of global fallout plutonium in seas adjacent to the Korean Peninsula is being gradually diluted by the high 240Pu/239Pu atom ratio plutonium transported from the tropical Pacific Proving Grounds via prevailing ocean current.

Journal Article↗

PubMed2004

Properties of 137Cs in marine sediments off Yangnam, Korea.

Concentrations of 137Cs in sediment and seawater samples in the East Sea (Japan Sea) adjacent to Yangnam, Korea were measured and data on the physical and chemical properties of the sediments were collected. The concentrations of 137Cs in the sediment samples were in the range of less than the minimum detectable activity (MDA)-7.19 Bq/kg-dry, and the values were linearly correlated with particle size, total organic carbon (TOC), H, N or S content of the sediment. The 137Cs concentrations in the sediment samples were well fitted to a multiple regression equation with TOC contents and particle size distributions. The distribution coefficients, which indicate the degree of adsorption, of 137Cs to the sediments were strongly dependent on particle size and TOC content.

Adsorption↗

PubMed2004

Sputum eosinophil counts and eosinophil cationic protein levels in cough-variant asthma and in classic asthma, and their relationships to airway hypersensitivity or maximal airway response to methacholine.

BACKGROUND: The aims of this study were to compare the degree of airway inflammation in cough-variant asthma (CVA) with that in classic asthma (CA), and to examine the relationship between airway inflammation and airway hypersensitivity or maximal airway response to methacholine in both conditions. METHODS: Sputum was induced in 41 CVA patients, in 41 methacholine PC(20)-matched CA patients, and in 20 healthy children. The sputum samples were analyzed for total and differential cell counts, and for eosinophilic cationic protein (ECP). A high-dose methacholine challenge test was performed in CVA and CA patients to determine PC(20) and maximal airway response. RESULTS: Sputum eosinophil percentages and ECP levels were significantly elevated in CVA and CA vs the control, but no significant differences were found between the two asthma groups. In the two asthma groups, neither sputum parameters correlated significantly with methacholine PC(20). However, the absence of a maximal response plateau or its higher level, when present, was associated with increased eosinophil percentages and ECP levels in the CVA group. CONCLUSIONS: The degree of eosinophilic inflammation may not be causally related to differences in presented asthma manifestations. The identification of a maximal response plateau and the level of this plateau in patients with CVA may provide information pertinent to airway eosinophilic inflammation.

Adolescent↗

PubMed2004

Reverse echelon node and a lymphatic ectasia in the same patient during breast lymphoscintigraphy: the importance of injection and imaging technique.

Lymphoscintigraphy, along with triangulated patient body marking, can serve as a guide for surgeons during sentinel lymph node harvesting. Unique drainage patterns have been noted, especially with areolar or intradermal based injections, which are becoming increasingly popular. The images lymphoscintigraphy provide have been invaluable in delineating these patterns. The authors present a case that simultaneously illustrates two separate points in the same patient, a reverse echelon node and a lymphatic ectasia. To our knowledge, this combination has never been described in the same patient. Perilesional and areolar-cutaneous junction injections were performed sequentially and generated these patterns that could potentially have resulted in added morbidity and a false-negative sentinel node if not realised before surgery. Lymphoscintigraphy added valuable information in the management of this patient, which can occasionally present with complex patterns of activity during sentinel node harvesting.

Adult↗

PubMed2004

Effects of 20-week intermittent cold-water-immersion on phenotype and myonuclei in single fibers of rat hindlimb muscles.

The effects of 20 weeks of intermittent cold-water-immersion on myosin heavy chain (MHC) expression,cross-sectional area (CSA), myonuclear number, and myonuclear domain size in isolated single fiber of soleus and extensor digitorum longus (EDL) muscles were studied in male Wistar rats. Cold exposure was accomplished by submerging the rats in shoulder-deep water, maintained at approximately 18 degrees C, for 1 hour/day, 5 days/week and for 20 weeks. Cold exposure resulted in a significant inhibition of body and soleus muscle weight gain. The percent type IIa MHC fibers of EDL muscle was increased, whereas that of type IIa + b MHC fibers was less in cold-exposed group than controls (p < 0.05). The mean CSA and myonuclear number in type I MHC fibers of soleus muscle in cold-exposed group were significantly less than controls. Myonuclear domain in type IIa fibers of EDL in the cold-exposed group was greater than controls (p < 0.05). It is suggested that prolonged cold exposure causes the fiber-type-specific adaptation in rat hindlimb muscles. It is further indicated that cold-exposure-related modulation of myonuclear number was closely related to reduction of fiber CSA, not the shift of fiber phenotype.

Animals↗

PubMed2003

Recent trends of plutonium fallout observed in Japan: plutonium as a proxy for desertification.

Plutonium in monthly deposition samples collected in Tsukuba (the Meteorological Research Institute), Japan from 1990 to end of 2001 is reported, together with monthly plutonium deposition in Nagasaki and Yonaguni in 2000. The annual deposition of (239,240)Pu during the period from 1990 to 2001 shows no systematic interannual variation. However, monthly (239,240)Pu depositions show a typical seasonal variation with a maximum in spring season (March to April), which corresponds to seasonal cycle of soil dusts originating from the East Asian arid area. Plutonium isotopic ratios in the deposition samples suggest that significant amounts of the recent (239,240)Pu deposition observed in Japan are attributed to the resuspension of plutonium-bearing surface soil particles; resuspended plutonium originates from the East Asian arid areas. The recent increased tendency of (239,240)Pu content in residues in deposition samples may reflect desertification in the East Asian continent.

Asia↗

PubMed2003

Muscle fibre size and capillarity in Korean diving women.

AIM: Effects of prolonged habitual cold-water immersion on fibre size and capillarity in vastus lateralis muscle were studied in human beings. The hypothesis tested in the present study was that cold acclimatized human skeletal muscle would have reduced muscle fibre size and higher capillarity, favouring the idea of efficacy of recruitment under cold environment. METHODS: Ten women breath-hold divers (BHDs) and 10 active women (controls CONs) participated in this study. Muscle biopsy was obtained from vastus lateralis and determined fibre type composition and capillary density. RESULTS: A major finding was that all BHDs revealed a markedly smaller cross-sectional area (CSA) in all fibre types than the CONs, or even than any other morphological data reported in previous investigations. Furthermore, mean CSA of type II fibre (range 1205-2766 microm2) was much smaller than type I fibre (2343-4327 microm2). The number of capillaries per fibre in different fibre types in the BHDs was higher than in the CONs (P < 0.001), and diffusional area was smaller in type II fibres than in type I fibres (P < 0.001). The BHDs and the CONs have similarity in the percentage of type I fibres, but type II fibre was predominant in both groups. Interestingly the proportion of type IIx fibre in the BHDs was higher (31%) than in the CONs (22%). No significant difference was found in the thigh circumference between the groups. CONCLUSION: The present study demonstrates that prolonged habitual cold-water immersion may induce a decrease in fibre size and an increase in capillarity in human skeletal muscle.

Adipose Tissue↗

PubMed2003

Sputum eosinophilia in cough-variant asthma as a predictor of the subsequent development of classic asthma.

BACKGROUND: A significant proportion of patients diagnosed with cough-variant asthma eventually manifest classic asthma signs, such as wheezing and dyspnoea. The aim of this study was to investigate whether the percentage of eosinophils and/or concentration of eosinophilic cationic protein (ECP) in sputum induced from patients with cough-variant asthma can predict the development of classic asthma. METHODS: Sixty-two children with cough-variant asthma were prospectively studied for 4 years. At the initiation of the study, sputum was induced with hypertonic saline, and the sputum samples were analysed for total and differential cell counts, and for ECP. Each subject was checked clinically at least every 3 months, and details of classic asthma signs experienced during the intervening periods were taken. RESULTS: Twenty-four (47.1%) of the 51 subjects available for follow-up developed signs of classic asthma, while 27 did not. The only significant difference in the sputum parameters between these two groups was a higher percentage of sputum eosinophils in subjects who developed classic asthma. A significant association was found between sputum eosinophil percentage and classic asthma development, but not between the concentration of sputum ECP and classic asthma development. CONCLUSION: Sputum eosinophilia in cough-variant asthma may be a correlate of the later development of classic asthma. This suggests that sputum differential cell counts may be useful in the clinical management of patients with cough-variant asthma, as they may enable the prediction of the subsequent classic asthma development.

Adolescent↗

PubMed2003

[Development of gerontological nursing curriculum model].

PURPOSE: This study was conducted to develop gerontological curriculum model which reflects the need of Korean society. METHOD: Three round Delphi survey method was applied to find consensus of gerontological nursing competencies (knowledge, attitudes and skills) for graduates of nursing schools from the panel of gerontological nursing practice experts. Important concepts in gerontological nursing were delineated from literature review and discussions of gerontological nursing educators. Based on these results the gerontological nursing curriculum model was developed and course structure outlined by the researchers as a group. RESULT: As the result of delphi survey, 32 items of knowledge, 29 items of attitude, and 21 items of skill were identified. The curriculum model constructed around a cube with three plane- functional capacity levels, settings, and nursing practice. Specific knowledge, attitudes and skills for gerontological theory and practicum course were suggested. Competency items were assigned to theory and/or practice. CONCLUSION: A curriculum model for gerontological nursing has been developed by a group of gerontological nursing educators. The curriculum model should be further tested and developed with detailed theory and practicum course outline and textbooks.

English Abstract↗

PubMed2002

Nonviral vector for efficient gene transfer to human ovarian adenocarcinoma cells.

OBJECTIVE: Various strategies have been attempted to design efficient protocols for ovarian cancer gene therapy but there has been little progress in their clinical application. In this study, we formulated and evaluated a new cationic liposome prepared with dioleoyltrimethylaminopropane (DOTAP), 1,2-dioleoyl-3-phosphophatidylethanolamine (DOPE), and cholesterol (Chol) (DDC) for plasmid DNA transfer into ovarian cancer cells. METHOD: The DDC liposome was prepared by mixing the DOTAP:DOPE:Cholin a 1:0.7:0.3 molar ratio using the extrusion method. Plasmid DNA (pEGFP-C1) and DDC were complexed at various weight ratios to find the optimum condition and the percentage of transfected cells was determined by selecting a green fluorescence protein (GFP) expressing cells in flow cytometry. The transfection efficiency of the DDC liposome was compared with 3[N-(N,N-dimethylaminoethylene) carbamoyl] cholesterol (DC-Chol)/DOPE liposome and commercially available lifopectin. RESULTS: The optimal transfection of plasmid DNA was achieved at a 1:4 (w/w) ratio of DDC to DNA. The DDC/DNA complex exhibited higher transfection efficiency in human ovarian cancer cells (OVCAR-3 and SK-OV-3 cells) compared to that in other types of cell lines (NCI-NIH:522 and HepG2 cells). Flow cytometric analysis revealed that the DDC/DNA complex exhibited an over fourfold increase in GFP expression levels compared with DC-Chol/DOPE or lipofectin in OVCAR-3 cells. This result was further confirmed by confocal microscopy and RT-PCR analysis. CONCLUSION: These results suggest that our newly formulated cationic liposome (DDC) appears to be a promising nonviral vector for treating ovarian adenocarcinoma because of its selective high gene transfer ability in ovarian cancer cells.

Adenocarcinoma↗

PubMed2002

The importance of maximal airway response to methacholine in the prediction of wheezing development in patients with cough-variant asthma.

BACKGROUND: A significant proportion of patients diagnosed with cough-variant asthma eventually manifest classic asthma signs, such as wheezing and dyspnea. The aim of this study was to investigate whether the degree of airway hypersensitivity and/or the level of maximal airway response can predict the development of wheezing in subjects with cough-variant asthma. METHODS: At study initiation, a high-dose methacholine inhalation test was performed to measure provocative concentration causing a 20% fall (PC20) in forced expiratory volume in 1 s (FEV1) and maximal airway response. Each person was evaluated regularly every 3 months for 4 years and also on the occasion of wheezing being perceived for the first time. RESULTS: Of the 48 patients available in the follow-up period, 21 (Group 1) developed clinical wheezing, while 27 (Group 2) did not. There was no significant difference in PC20 levels between the two groups. The level of maximal airway response, however, was significantly higher in Group 1 than in Group 2. The score test for trend revealed a significant association between the future development of wheezing and the level of maximal airway response (P = 0.007), but not the level of methacholine PC20 (P = 0.423). CONCLUSIONS: The level of maximal airway response, rather than the degree of airway hypersensitivity, may be an important risk factor for the future development of classic asthma in patients with cough-variant asthma.

Adolescent↗

PubMed2002

The importance of maximal airway response to methacholine in the prediction of asthma development in patients with allergic rhinitis.

BACKGROUND: Allergic rhinitis is a known predictor and correlate of asthma incidence. However, it is not clear which patients with allergic rhinitis are at greater risk of the development of asthma. OBJECTIVE: The aim of this study was to investigate whether airway hypersensitivity and/or increased maximal response on the dose-response curve to methacholine would predict the development of asthma in subjects with allergic rhinitis. METHODS: One hundred and forty-one children with allergic rhinitis were prospectively studied for 7 years. At the initiation of the study, bronchial provocation test with methacholine using a stepwise increasing concentration technique was performed to measure PC(20) (provocative concentration causing a 20% fall in FEV(1)) and maximal response. Each subject was evaluated at least every 6 months and details of asthmatic symptoms or signs experienced during the intervening period were taken. RESULTS: Twenty of 122 subjects available for the follow-up developed asthma. Nine (19.6%) of 46 hypersensitive (PC(20) < 18 mg/mL) subjects developed asthma, compared with 11 (14.5%) of 76 normosensitive subjects (P = 0.462). Eight (32%) of 25 subjects without maximal response plateau developed asthma, compared with 12 (12.4%) of 97 subjects with maximal response plateau (P = 0.018). Score test for trend revealed a significant association between the level of maximal response (P = 0.007), but not the degree of methacholine PC(20) (P = 0.123), and the future development of asthma. CONCLUSION: An increased maximal airway response to methacholine is shown to be a better predictor for the future development of asthma in patients with allergic rhinitis, than airway hypersensitivity to methacholine.

Adolescent↗

PubMed2001

Effect of sodium chloride on the gelation temperature, gel strength and bioadhesive force of poloxamer gels containing diclofenac sodium.

Liquid suppository systems composed of poloxamers and bioadhesive polymers were easy to administer to the anus and mucoadhesive to the rectal tissues without leakage after the dose. However, a liquid suppository system containing diclofenac sodium could not be developed using bioadhesive polymers, since the drug was precipitated in this preparation. To develop a liquid suppository system using sodium chloride instead of bioadhesive polymers, the physicochemical properties such as gelation temperature, gel strength and bioadhesive force of various formulations composed of diclofenac sodium, poloxamers and sodium chloride were investigated. The mixtures of P 407 (15%) and P 188 (15-20%) existed as a liquid at room temperature, but gelled at physiological temperature. Diclofenac sodium significantly increased the gelation temperature and weakened the gel strength and bioadhesive force, while sodium chloride did the opposite. Furthermore, the poloxamer gels with less than 1.0% of sodium chloride, in which the drug was not precipitated, were inserted into the rectum of rabbits without difficulty and leakage, and retained in the rectum of rats for at least 6 h. Our results suggested that a thermosensitive liquid suppository system with sodium chloride and poloxamers was a more physically stable and convenient rectal dosage form for diclofenac sodium.

Animals↗

PubMed2001

Nasal absorption and biodistribution of plasmid DNA: an alternative route of DNA vaccine delivery.

Nasal administration is emerging as a new route of DNA vaccine delivery. We aimed to study the extent of absorption and biodistribution of intranasally administered plasmid DNA. After intranasal administration, the level of plasmid DNA in the serum peaked at 1.5 h. The ratio of the area under the concentration (AUC) after intranasal administration of DNA over the AUC after intravenous administration was 0.14. At 15 min post inoculation, the highest organ distribution was observed in the liver and the cervical lymph nodes showed the highest level among the lymph nodes. At 24 h a higher localization of plasmids to the brain than to the lung and spleen was notable. A significant level of mRNA expression was observed in the lymph nodes. These results suggest that plasmid DNA can be substantially absorbed and distributed to the lymph nodes after intranasal administration, partly explaining the systemic immunogenicity of intranasally administered plasmid DNA vaccines.

Administration, Intranasal↗

PubMed2001

Bioavailability of cyclosporin A dispersed in sodium lauryl sulfate-dextrin based solid microspheres.

The purpose of this work was to develop a solid dispersion system containing cyclosporin A (CsA) in order to improve the bioavailability of poorly water-soluble CsA. Solid dispersion systems that are spherical in shape (CsA-microspheres) were prepared with varying ratios of CsA/sodium lauryl sulfate/dextrin using a spray-drying technique. The effects of sodium lauryl sulfate (SLS) and dextrin on the dissolution of CsA dispersed in SLS-dextrin based solid microspheres were investigated. The bioavailability of CsA-microspheres was compared with CsA powder alone and commercial Sandimmun in dogs. SLS significantly enhanced the dissolution of CsA from microspheres, while dextrin did not affect this. The CsA-microspheres at the CsA/SLS/dextrin ratio of 1/3/1, which gave the highest dissolution rate of CsA among the formula treated, was selected as an optimal formula for oral delivery. This formula gave significantly higher blood levels, area under the drug concentration-time curve (AUC) and maximum blood concentration of drug (Cmax) of CsA in dogs compared with the CsA powder alone. The AUC, Cmax and time to reach maximum blood concentration (Tmax) of CsA with CsA-microspheres was not significantly different from those after oral administration of Sandimmun, suggesting the similar bioavailability to Sandimmun in dogs. Our study demonstrates that the CsA-microspheres prepared with SLS and dextrin, with improved bioavailability of CsA, would be useful to deliver a poorly water-soluble CsA and could be applicable to other poorly water-soluble drugs.

Animals↗

PubMed2001

Nucleophilic substitution at the imidoyl carbon atom: intermediate mechanistic and reactivity behavior between carbonyl and vinyl carbon substitution.

Gas-phase nucleophilic substitution reactions at the imidoyl carbon have been investigated using chloride exchanges, Cl- + RY=CHCl right harpoon over left harpoon RY=CHCl + Cl- with Y = N and R = F, H or CH3, at the MP2, B3LYP and G2(+) levels using the MP2/6-311+G geometries. The results are compared with those for the vinyl (Y = CH) and carbonyl (Y = O) carbon substitution. The mechanism and reactivity of substitution at the imidoyl carbon are intermediate between those of carbonyl (SNpi) and vinyl carbon (SNsigma) substitution, which is directly related to the electronegativity of Y, CH < N < O. The prediction of competitive SNsigma with SNpi path for the imidoyl chloride is consistent with the S(N)1-like mechanism proposed for reactions in solution. The important factors in favor of an in-plane concerted SN2 (SNsigma) over an out-of-plane pi-attack (SNpi) path are (i) lower proximate sigma-sigma* charge-transfer energies (DeltaECT), (ii) stronger electrostatic stabilization (DeltaENCT), and (iii) larger lobe size on C(alpha) for the sigma*- than pi*-LUMO despite the higher sigma* than pi* level. The electron correlation energy effects at the MP2 level are overestimated for the relatively delocalized structure (S(N)pi TS) but are underestimated for the localized structure (SNsigma TS) so that the MP2 energies lead to a wrong prediction of preferred reaction path for the vinyl chloride. The DFT at the B3LYP level predicts correct reaction pathways but overestimates the electron correlation effects.

Journal Article↗

PubMed2001

Involvement of acetyl phosphate in the in vivo activation of the response regulator ComA in Bacillus subtilis.

Development of genetic competence in Bacillus subtilis is regulated by ComP--ComA, a two-component signal transduction system. The response regulator ComA is primarily activated by ComP, a histidine kinase that mediates response to nutrient conditions and cell density, and the activated ComA is required for transcription of the srf operon, which is essential for the development of genetic competence and surfactin production. In this study we suggested that the ComA could also be activated by a small molecule phospho-donor, acetyl phosphate. Examination of srfA-lacZ expression indicated that a significant amount of srfA expression still occurs in the comP mutant during growth in a sporulation medium containing excess glucose. Analysis of a comP and pta mutant suggests that srfA activation seen in the comP mutant is dependent on the expression of pta, which encodes phosphotransacetylase (Pta). As Pta is responsible for the catalysis for conversion of acetyl coenzyme A to acetyl phosphate, we conclude that the expression of srfA seen in the comP mutant is mainly due to the activation of ComA by acetyl phosphate.

Bacillus subtilis↗

PubMed2001

Preparation and evaluation of biphenyl dimethyl dicarboxylate microemulsions for oral delivery.

To improve the solubility and bioavailability of poorly water-soluble biphenyl dimethyl dicarboxylate (BDD), a drug used in treating liver diseases, a premicroemulsion concentrate composed of oil, surfactant, and cosurfactant for oral administration of BDD was prepared, and its physicochemical properties and the pharmacokinetic parameters of BDD were evaluated. Among the non-ionic surfactants and oils studied, Tween 80, which led to the highest solubility of BDD (109.7 microg/ml), and Neobee M-5((R)) were chosen for preparing a premicroemulsion concentrate. At the 2:1 ratio of Tween 80 to Neobee M-5((R)), the solubility of BDD increased 7-fold compared with that at the ratio of 1:4. The solubility of BDD was further improved by the addition of triacetin used as a cosurfactant. Droplet size of BDD microemulsion comprising Tween 80 and Neobee M-5((R)) at the ratio of 2:1, and 35% of triacetin, was kept constant both in distilled water and artificial gastric fluid without pepsin (pH 1.2) throughout 120-min incubation period. BDD in premicroemulsion concentrate rapidly dissolved whereas the mixture of BDD and calcium-carboxymethylcellulose (Ca-CMC) (2:1) and BDD powder hardly dissolved during 120-min incubation. About 50% of BDD in premicroemulsion concentrate dissolved within 10 min. AUC(0-->24 h) and the mean maximum plasma level (C(max)) of BDD after oral administration of premicroemulsion concentrate in rats were 5- and 9.8-fold higher, respectively, than those of BDD with Ca-CMC. These results demonstrate that premicroemulsion concentrate of BDD composed of Tween 80 and Neobee M-5((R)) at the ratio of 2:1, and 35% of triacetin, greatly enhances the bioavailability of BDD after the dose, possibly due to the increase in solubility and immediate dispersion of drug in the gastrointestinal tract. Thus, this system may provide a useful dosage form for oral intake of a water-insoluble drug, BDD.

Administration, Oral↗