Biomedical subjects

N S Kim

Publications and source records attributed to N S Kim.

At least 19 recordsLinked to original sources

PubMed2005

Morphometric studies on the testis of Korean ring-necked pheasant (Phasianus colchicus karpowi) during the breeding and non-breeding seasons.

The purpose of this study was to obtain detailed quantitative information on all cell types in the testis interstitium of Korean ring-necked pheasants and to combine these data with changes in the steroidogenic function of the testis during the breeding and non-breeding seasons. For animals collected during the breeding season, their testis weights, sperm production, serum testosterone levels and leuteinizing hormone (LH)-stimulated testosterone secretion were significantly (p < 0.01) increased compared to the non-breeding season. Testes of the pheasants during the non-breeding season displayed a 98% reduction in testis volume that was associated with a decrease in the absolute volume of seminiferous tubules (98% reduction), tubular lumen (100%), interstitium (90%), blood vessels (84%), lymphatic spaces (97%), Leydig cells (79%), mesenchymal cells (51%) and myoid cells (61%) compared to the breeding season. The numbers of Leydig cells, mesenchymal cells and myoid cells per testis in the breeding season were much higher than in the non-breeding season. Although the mean volume of a Leydig cell was 74% lower in the non-breeding season, the mean volumes of myoid and mesenchymal cells remained unchanged. These results demonstrate that there are striking differences in the testicular structure of the Korean ring-necked pheasant during the breeding and non-breeding seasons. Every structural parameter of the Leydig cell was positively correlated with both testosterone serum levels and LH-stimulated testosterone secretion. The correlation of changes in hormonal status with the morphometric alterations of Leydig cells suggests that the Korean-ring necked pheasant may be used as a model to study structure-function relationships in the avian testis.

Animals↗

PubMed2004

Detection and physical mapping of the 18S-5.8S-26S rDNA and the pKFJ660 probe with microsatellite sequences derived from the rice blast fungus (Magnaporthe grisea) in conifer species.

Sequences homologous to the pKFJ660 probe, a fragment of DNA derived from the rice blast fungus (Magnaporthe grisea) carrying TC/AG repeat microsatellite sequences and 30 bp direct repeats were identified in the genome of Picea (spruce) and Pinus (pine) species by fluorescence in situ hybridization (FISH) and slot blot analyses. Slot blot analysis using the pKFJ660 probe revealed hybridization signals with genomic DNAs from various pine and spruce species. Further analyses indicated that the copy number of the (AG)30 motif was higher than 5 x 10(4) per plant genome for all plant samples tested, but the copy number of the sequences homologous to the whole pKFJ660 probe varies considerably among the 25 plant species tested. In situ hybridization of metaphase chromosomes from Pinus resinosa, P. banksiana and P. strobus showed the presence of sequences homologous to this probe on several chromosomes in a dispersed pattern. Major signals were observed on a few chromosomes indicating that some of these sequences are clustered in specific genomic locations. The locations of these repeats were compared to those of 18S-5.8S-26S rDNA in pine species. Chromosomal distribution of 18S-5.8S-26S rDNA varied among the three pine species (P. resinosa, P. banksiana and P. strobus) studied. Ribosomal DNA (rDNA) sites were identified on 14 to 20 chromosomes in these pine species.

Base Sequence↗

PubMed2003

Accumulation of tributyltin in olive flounder, Paralichthys olivaceus: its effect on hepatic cytochrome P450.

Accumulation of tributyltin (TBT) was determined in liver of olive flounder exposed to TBT (3.65, 36.5, 365, 3,650, and 7,300 ng Sn/L) for 10 or 30 days, followed by 60 days depuration. Effect of TBT on hepatic cytochrome P450 content was also measured in liver of olive flounder. TBT was highly accumulated in liver of fish during the 10- to 30-day exposures, and hepatic cytochrome P450 content decreased with increasing TBT concentration. Hepatic cytochrome P450 contents were affected in olive flounder exposed to even environmentally relevant TBT concentrations, such as 3.65 ng Sn/L. In addition, the liver TBT levels demonstrated strong negative correlation to the hepatic cytochrome P450 content. The effects started to appear from 20 ng Sn/g dry weight of TBT in liver. Tributyltin concentrations and hepatic cytochrome P450 were also determined in feral fine-spotted flounder. The relationship between other organic pollutants known as cytochrome P450 inducers (e.g., polychlorinated biphenyls) as well as TBT and hepatic cytochrome P450 in the feral fish implied that TBT even at ppt level could impose antagonistic effects on hepatic cytochrome P450 induction.

Animals↗

PubMed2002

Horizontal and vertical distribution of butyltin compounds in sediments from shipyards in Korea.

Butyltin compounds were quantitatively determined in surface sediment and sediment core samples near shipyards in the south coast of Korea, which is one of the major ship building industries in the world. Tributyltin (TBT) concentrations reached up to 46100 ng Sn/g on a dry-weight basis at the front of the shipyard. Horizontal distribution of butyltin compounds was closely related to dry-docking activities. Butyltin concentrations were relatively low where remote from the sources. The vertical distribution of TBT in sediment cores showed active use of TBT in Korean peninsula for the past decades. The increase of TBT concentrations in sediment core according to estimated sediment age demonstrated a positive correlation with the increase of gross tonnage of ships built in the shipyard for 20 years. High TBT residue levels in sediment core samples raise concerns over persistence of the compound in the marine environment.

Environmental Monitoring↗

PubMed2002

The relationship between body mass index and the prevalence of obesity-related diseases based on the 1995 National Health Interview Survey in Korea.

This study estimated the body mass index (BMI) distribution of Koreans and examined the relationship between BMI and obesity-related diseases, in particular hypertension and diabetes mellitus. We also attempted to provide primary data to determine suitable BMI cut-off points for obesity in Korea. The 1995 National Health Interview Study (NHIS) data were used to estimate BMI and the prevalence of hypertension and diabetes mellitus. A random sample of 5750 Koreans (15-69 years of age) were investigated. BMI was calculated by self-reported weights and heights. The diagnoses of hypertension and diabetes mellitus were obtained from self-reported conditions specified in response to consultations with physicians. The mean BMI was 22.6+/-2.6 kg m(-2) for males and 21.7+/-4.8 kg m(-2) for females. The prevalence of hypertension and diabetes mellitus increased with BMI. The odds ratios of the third quartile of BMI (21.9-23.8 kg m(-2)) for hypertension and diabetes mellitus compared with the first quartile were 6.04 and 3.22, respectively. The odds ratio of the fourth quartile (>23.8 kg m(-2)) of BMI was not significantly different from that of the third quartile. The risk of hypertension and diabetes mellitus increased at the third quartile of BMI (21.9-23.8 kg m(-2)), this quartile being much lower than both the current World Health Organization (WHO) BMI cut-off point of overweight of 25.0 kg m(-2), and the 90th percentile proposed in the Monica project, BMI 26.4 kg m(-2). This finding was notable considering the fact that both hypertension and diabetes mellitus occur in Koreans with lower BMIs than whites. Further studies are necessary to identify the BMI cut-off point for obesity in Korea.

Adolescent↗

PubMed2002

A microsatellite sequence from the rice blast fungus (Magnaporthe grisea) distinguishes between the centromeres of Hordeum vulgare and H. bulbosum in hybrid plants.

A TC/AG-repeat microsatellite sequence derived from the rice blast fungus (Magnaporthe grisea) hybridized to all of the centromeres of Hordeum vulgare chromosomes, but hybridized faintly or not at all to the chromosomes of Hordeum bulbosum. Using this H. vulgare centromere-specific probe, the chromosomes of four F1 hybrids between H. vulgare and H. bulbosum were analyzed. The chromosome constitution in the root tips of the hybrids was mosaic, i.e., 7 (7v, H. vulgare) and 14 (7v + 7b H. bulbosum), or 14 (7v + 7b) and 27 (14v + 13b), or 7 (7v), 14 (7v + 7b), and 27 (14v + 13b). The 27-chromosome tetraploid hybrid cells were revealed to have the NOR (nucleolus organizer region) bearing chromosome of H. bulbosum in a hemizygous state, which might indicate some role for this chromosome in the chromosome instability of the hybrid condition. The chromosomal distribution showed that the chromosomes of H. vulgare were concentric and chromosomes of H. bulbosum were peripheral in the mitotic squash. This non-random chromosome distribution and the centromere-specific repeated DNA differences in the two species were discussed in relation to H. bulbosum chromosome elimination. Meiotic chromosome analyses revealed a high frequency of homoeologous chromosome pairing in early prophase. However, this chromosome pairing did not persist until later meiotic stages and many univalents and chromosome fragments resulted. These were revealed to be H. bulbosum by fluorescence in situ hybridization (FISH) analysis with the H. vulgare centromere-specific probe. Because the chromosome segregation of H. vulgare and H. bulbosum chromosomes at anaphase I of meiosis was random, the possibility for obtaining chromosome substitution lines in diploid barley from the diploid hybrid was discussed.

Base Sequence↗

PubMed2001

Pain after laparoscopic cholecystectomy: the effect and timing of incisional and intraperitoneal bupivacaine.

PURPOSE: To examine the combined preemptive effects of somatovisceral blockade during laparoscopic cholecystectomy (LC). METHODS: One hundred fifty-seven patients under general anesthesia receiving local infiltration and/or topical peritoneal local anesthesia were studied. Patients were randomized to receive a total of 150 mg (0.25% 60 mL) bupivacaine via periportal (20 mL) and intraperitoneal (40 mL with 1:200,000 epinephrine) administration of each. Group A received preoperative periportal bupivacaine before incision and intraperitoneal bupivacaine immediately after the pneumoperitoneum. Group B received periportal and intraperitoneal bupivacaine at the end of the operation. Group C (preoperative) and Group D (postoperative) received only periportal bupivacaine and Group E (preoperative) and Group F (post-operative) received only intraperitoneal bupivacaine. The control group received no treatment. Pain and nausea were recorded at one, two, three, six, nine, 12, 24, 36, and 48 hr postoperatively. RESULTS: Throughout the postoperative 48 hr, incisional somatic pain dominated over other pain localizations in the control group (P <0.05). The incisional pain of groups A, B, C and D was significantly lower than that of the control group in the first and second hours. The incisional pain of groups A and C was significantly lower than that of the control group in the first three hours. CONCLUSION: Incisional pain dominated during the first two post-operative days after LC. Preoperative somato-visceral or somatic local anesthesia reduced incisional pain during the first three post-operative hours. A combination of somato-visceral local anesthetic treatment did not reduce intraabdominal pain, shoulder pain or nausea more than somatic treatment alone. Preoperative incisional infiltration of local anesthetics is recommended.

Adult↗

PubMed2001

Gamma-interferon (IFN-gamma) augments apoptotic response to mistletoe lectin-II via upregulation of Fas/Fas L expression and caspase activation in human myeloid U937 cells.

Mistletoe lectin-II, a major composition of Korean mistletoe (Viscum album coloratum), is known as a potent apoptosis inducer. The previous research has demonstrated that Korean mistletoe lectin-II induces apoptosis via c-Jun N terminal kinase (JNK) activation in human myeloid U937 cells. The purpose of this research is to prove the synergistic action of mistletoe lectin-II and interferon-gamma (IFN-gamma) in the apoptotic cytotoxicity of U937. When U937 cells were treated with mistletoe lectin-II after being differentiated by IFN-gamma, the proteolytic activity of caspase-3 and 9 was markedly elevated and that of caspase-8 was prolonged for 18 hr. The activation of caspase-3-like protease requires the earlier cleavage of poly(ADP-ribose) polymerase(PARP). Caspase-1 was, however, not activated during the resting phase and nor in IFN-gamma-differentiated U937 cells. Western blot analysis revealed that, in IFN-gamma-differentiated U937 cells, the expression of Fas (CD95/APO-1) & Fas ligand(FasL) increases the apoptotic sensitivity against Mistletoe lectin-II. Fas (CD95/APO-1) & FasL were not significantly induced solely by mistletoe lectin-II. Furthermore the activity of JNK1 in U937 cells was also markedly increased with IFN-gamma-differentiation, compared to that of the control. These results suggest that the IFN-gamma-differentiation of U937 cells increases the susceptibility to mistletoe lectin-II-induced apoptosis.

Apoptosis↗

PubMed2001

Phosphatidylinositol 3-kinase regulates proliferation of RAW 264.7 macrophages.

Phosphatidylinositol 3-kinase (P13-kinase) is an enzyme that acts as a direct biochemical link between a novel phosphatidylinositol pathway and a number of proteins containing intrinsic or associated kinase activities. Here we demonstrate that wortmannin, P13-kinase inhibitor, decreases the proliferation of RAW 264.7 macrophages and that another structurally unrelated inhibitor of P13-kinase, LY294002. also inhibits the proliferation. These results indicate a possible involvement of P13-kinase in RAW 264.7 macrophages growth regulation. Wortmannin stimulation of RAW 264.7 macrophages is followed by sustained expression of the mRNA of c-fos and a transient expression of the mRNA of c-jun. We also show that the wortmannin and LY294002 induce a cell cycle arrest in asynchronously growing cells leading to an inhibition of cell proliferation after 12 h of treatment. In addition, wortmannin or LY294002 inhibited the phorbol 12-myristate 13-acetate-induced macrophages proliferation potently. These results suggest that P13-kinase plays an important role in growth regulation of RAW 264.7 macrophages and that protein kinase C is a down stream effector of P13-kinase.

Androstadienes↗

PubMed2001

Inhibitory effect of immunoglobulin E production by jin-deuk-chal (Siegesbeckia orientalis).

Elevated levels of immunoglobulin (Ig) E are associated with immediate-type allergic reactions. Jin-deuk-chal is the whole plant of Siegesbeckia orientalis (SO) sL Immunization of mice with small amounts of protein antigens on alum results in several fold increases in total plasma IgE, much of it specific for the immunizing antigen. In the present study, we investigated the effect of Siegesbeckia orientalis (SO) on IgE production. SO inhibited the plasma levels of IgE induced by antigens. The effects of SO on the interleukin (IL)-4-dependent IgE response by mouse whole spleen cells were studied. IL-4 dependent IgE production of lipopolysaccharide (LPS)-stimulated whole spleen cells was inhibited by SO. In addition, using U266B I human IgE-bearing B cells, we found that SO inhibited the production of IgE activated by LPS plus IL-4. These results suggest that SO have antiallergic activity by inhibition of IgE production from B cells.

Animals↗

PubMed2001

2,2-Diphenyl-1-picrylhydrazyl hydrate, a stable free radical, is an alpha-glucosidase inhibitor.

Glycosidases play a pivotal role in processing of various glycoproteins and glycolipids. It is well known that glycosidases are also involved in a variety of degenerative metabolic disorders such as cancer and AIDS. In order to develop potent alpha-glucosidase inhibitors, we first screened 2,2-diphenyl-1-picrylhydrazyl hydrate as a candidate. 2,2-Diphenyl-1-picrylhydrazyl hydrate was found to inhibit alpha- and beta-glucosidases as well as alpha- and beta-mannosidases. It was also shown to be a non-competitive inhibitor of yeast alpha-glucosidase with a Ki value of 1.1 x 10(-6) M. Taken together, we anticipate that 2,2-diphenyl-1-picrylhydrazyl hydrate may be a potent inhibitor for some incurable metabolic disorders including AIDS.

Bepridil↗

PubMed2001

Systemic lupus erythematosus complicated with cerebral venous sinus thrombosis : a report of two cases.

A rare manifestation of systemic lupus erythematosus (SLE) is cerebral venous sinus thrombosis (CVST), in which early diagnosis and aggressive therapy are of prime importance for favorable outcome. The pathogenesis of CVST is largely unknown, but it is thought to be caused by cerebral vasculitis, antiphospholipid antibodies or other conditions associated with enhanced coagulability. We describe two cases of SLE with CVST which were not associated with antiphospholipid antibodies. Both cases were treated with immunosuppressants (intravenous methylprednisolone and cyclophosphamide pulse therapy) and anticoagulant drugs (heparin and subsequent maintenance therapy with warfarin). There was a marked improvement of neurologic symptoms with the disappearance of thrombus in a follow-up MRI. The possibility of CVST should be considered in any patients with SLE who show neuropsychiatric manifestations.

Adult↗

PubMed2000

Determination of floral fragrances of Rosa hybrida using solid-phase trapping-solvent extraction and gas chromatography-mass spectrometry.

Floral fragrances emanated from Rosa hybrida were determined by solid-phase trapping extraction and GC-MS. A novel protocol of sampling technique was established. There is a variation in the recoveries depending on the adsorbent and components. A total of 41 compounds were identified in the floral fragrances of Rosa hybrida. These include alcohols, aldehydes, alkanes, monoterpenes, sesquiterpene, esters, ether and ketones. Citral, n-nonane, n-butyl acetate, n-decane, beta-phenylethyl acetate and hexadecanol were major components. Floral fragrances differ between rose species and sample to sample within a single species. Interestingly, endocrine disruptors such as bis(2-ethylhexyl) phthalate were detected simultaneously.

Adsorption↗

PubMed2000

Isolation of TC/AG repeat microsatellite sequences for fingerprinting rice blast fungus and their possible horizontal transfer to plant species.

Genome fingerprinting has been a major role in characterization of population structure and analysis of the variability in phytopathogenic fungi. In order to characterize Korean rice blast fungal isolates, the genomic DNAs were digested with AluI endonuclease and subsequent PCR amplifications using random decamer primers with combinations of microsatellite primers had been carried out. This Alu-Inter SSR technique revealed high polymorphism among the Korean blast fungal isolates. Then, fragments from the Alu-Inter SSR analysis were isolated to be used as probes in Southern hybridization, which also revealed high polymorphism between isolates to distinguish individuals. The sequences of the isolated fragments contained TC/AG tandem repeats interspersed with a 30 bp direct repeat. In gel blot analysis, the isolated TC/AG repeat microsatellite sequences were proved to be useful for characterizing the isolates in blast fungi in addition to the conventional MGR (Magnaporthe grisea repeat) probes. One interesting point was that the rice blast fungus derived TC/AG repeat microsatellite sequences were abundant in non-rice blast fungi and plant species, but not in other fungi and yeasts. A discussion on the possible horizontal gene transfer between phytopathogenic fungi and host plants is presented.

Base Sequence↗

PubMed2000

Chromosomal localization and sequence variation of 5S rRNA gene in five Capsicum species.

Chromosomal localization and sequence analysis of the 5S rRNA gene were carried out in five Capsicum species. Fluorescence in situ hybridization revealed that chromosomal location of the 5S rRNA gene was conserved in a single locus at a chromosome which was assigned to chromosome 1 by the synteny relationship with tomato. In sequence analysis, the repeating units of the 5S rRNA genes in the Capsicum species were variable in size from 278 bp to 300 bp. In sequence comparison of our results to the results with other Solanaceae plants as published by others, the coding region was highly conserved, but the spacer regions varied in size and sequence. T stretch regions, just after the end of the coding sequences, were more prominant in the Capsicum species than in two other plants. High G x C rich regions, which might have similar functions as that of the GC islands in the genes transcribed by RNA PolII, were observed after the T stretch region. Although we could not observe the TATA like sequences, an AT rich segment at -27 to -18 was detected in the 5S rRNA genes of the Capsicum species. Species relationship among the Capsicum species was also studied by the sequence comparison of the 5S rRNA genes. While C. chinense, C. frutescens, and C. annuum formed one lineage, C. baccatum was revealed to be an intermediate species between the former three species and C. pubescens.

Base Sequence↗

PubMed2000

Expression and function of ryanodine receptors in human melanocytes.

We investigated the expression of ryanodine receptors (RyRs) in cultured human melanocytes with immunocytochemistry and reverse transcriptase-polymerase chain reaction. With the use of a monoclonal antibody, RyR immunoreactivity was detected in the cytoplasm of melanocytes, and was further confirmed by RT-PCR assay. The PCR products were cut with restriction enzymes specific for each RyR isoform. Using the RyR1-specific restriction enzyme SacI yielded fragments of 300, 100, and 130 base pairs, consistent with the expression of RyR1 isoforms. The function of RyR in Ca(2+) signaling was investigated using single-cell fura-2 imaging. Ryanodine (1 to approximately 100 microM) induced significant elevation of cytoplasmic Ca(2+) in single human melanocytes in a dose-dependent manner. The ryanodine-induced [Ca(2+)](i) increase was inhibited by neomycin. Furthermore, ryanodine inhibited proliferation and stimulated pigmentation of human melanocytes. This study demonstrates that the RyR1 isoform is expressed in cultured human melanocytes, and suggests that the RyR may be involved in regulating the intracellular Ca(2+) responses involved in proliferation and pigmentation of cultured human melanocytes.

Calcium↗

PubMed2000

Causal status as a determinant of feature centrality.

One of the major problems in categorization research is the lack of systematic ways of constraining feature weights. We propose one method of operationalizing feature centrality, a causal status hypothesis which states that a cause feature is judged to be more central than its effect feature in categorization. In Experiment 1, participants learned a novel category with three characteristic features that were causally related into a single causal chain and judged the likelihood that new objects belong to the category. Likelihood ratings for items missing the most fundamental cause were lower than those for items missing the intermediate cause, which in turn were lower than those for items missing the terminal effect. The causal status effect was also obtained in goodness-of-exemplar judgments (Experiment 2) and in free-sorting tasks (Experiment 3), but it was weaker in similarity judgments than in categorization judgments (Experiment 4). Experiment 5 shows that the size of the causal status effect is moderated by plausibility of causal relations, and Experiment 6 shows that effect features can be useful in retrieving information about unknown causes. We discuss the scope of the causal status effect and its implications for categorization research.

Cognition↗

PubMed2000

Behavioral differences between donor site-matched adult and neonatal melanocytes in culture.

Little is known about the biologic behaviors of cultured melanocytes in relation to donor age. To investigate age-dependent differences, neonatal and adult melanocytes were isolated from the same anatomical site, the foreskin, and cultured in the same growth medium supplemented with cAMP inducers (choleratoxin and 3-isobutyl-methylxanthine). The morphology, melanin content, pattern of melanosome distribution, and growth rate were then compared. Neonatal melanocytes were bipolar in appearance, whereas adult melanocytes were highly dendritic in appearance. Image analysis showed that adult melanocytes were larger and longer, and had a greater number of dendrites than neonatal melanocytes. When the growth medium was replaced by a medium without cAMP inducers, adult melanocytes showed a change in their morphology from dendritic to spindle-shaped, while the morphology of neonatal melanocytes remained unchanged. Melanosomes of adult melanocytes were distributed singly along the dendrites, and extracellular secretion of melanosomes was also found. In contrast, melanosomes of neonatal melanocytes were aggregated near the nuclei. No age-dependent differences in melanin content and growth rate were noted in the donor site-matched cultured melanocytes. These results suggest that donor age is one of the factors involved in determining melanocyte dendricity and melanosome distribution, and that increased dendricity of adult melanocytes is due to increased sensitivity to cAMP inducers. In addition, the adult melanocytes established in our culture system, which resembled dendritic melanocytes in vivo, could be considered a desirable model for studying the mechanisms of adult-onset hyperpigmentary disorders and melanogenesis.

1-Methyl-3-isobutylxanthine↗