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Biomedical subjects

J T Kim

Publications and source records attributed to J T Kim.

At least 37 records · Page 2Linked to original sources
PubMed1999

A DEF/GLO-like MADS-box gene from a gymnosperm: Pinus radiata contains an ortholog of angiosperm B class floral homeotic genes.

The specification of floral organ identity during development depends on the function of a limited number of homeotic genes grouped into three classes: A, B, and C. Pairs of paralogous B class genes, such as DEF and GLO in Antirrhinum, and AP3 and PI in Arabidopsis, are required for establishing petal and stamen identity. To gain a better understanding of the evolutionary origin of petals and stamens, we have looked for orthologs of B class genes in conifers. Here we report cDNA cloning of PrDGL (Pinus radiata DEF/GLO-like gene) from radiata pine. We provide phylogenetic evidence that PrDGL is closely related to both DEF- and GLO-like genes of angiosperms, and is thus among the first putative orthologs of floral homeotic B function genes ever reported from a gymnosperm. Expression of PrDGL is restricted to the pollen strobili (male cones) and was not detected in female cones. PrDGL expression was first detected in emergent male cone primordia and persisted through the early stages of pollen cone bud differentiation. Based on the results of our phylogeny reconstructions and expression studies, we suggest that PrDGL could play a role in distinguishing between male (where expression is on) and female reproductive structures (where expression is off) in radiata pine. We speculate that this could be the general function of DEF/GLO-like genes in gymnosperms that may have been recruited for the distinction between stamens and carpels, the male and female reproductive organs of flowering plants, during the evolution of angiosperms out of gymnosperm-like ancestors.

Amino Acid Sequence↗
PubMed1999

Intracardiac tuberculoma.

We examined a case of endocardial tuberculoma at the proximal superior vena cava and the right atrium in a 17-year-old male patient. He had frequent palpitations and general weakness for about 7 months and was referred for evaluation of incessant atrial tachyarrhythmia. Results of echocardiography and magnetic resonance imaging showed an intracardiac mass, which was excised using cardiopulmonary bypass. Histology of the mass was consistent with the diagnosis of tuberculoma. The patient's postoperative course was uneventful and he was discharged with antituberculous medication. Five months after the operation, the patient was well without tachycardia, and follow-up echocardiography showed complete disappearance of the mass.

Adolescent↗
PubMed1999

Degeneration and transdifferentiation of human lens epithelial cells in nuclear and anterior polar cataracts.

PURPOSE: To study the possible mechanisms of cataractogenesis by evaluating the characteristics of cataractous lens epithelial cells (LECs) in different types of human cataract. SETTING: Kangnam St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea. METHODS: Lens epithelial cells attached to the anterior capsules in eyes with nuclear or anterior subcapsular were analyzed for morphological characteristics by electron microscopy and for cellular characteristics by immunohistochemistry. RESULTS: Human LECs beneath the anterior capsule were degenerated in nuclear cataracts and were transdifferentiated in anterior polar cataracts. In senile nuclear cataractous lenses, LECs beneath the anterior capsule showed degenerative changes in morphology. In nuclear cataracts, LECs were immunohistochemically positive for cytokeratin and vimentin, while those in anterior polar cataracts were positive for vimentin only. The LECs of anterior subcapsular cataracts were transdifferentiated into spindle-shaped fibroblast-like cells without cellular junctions and embedded within a fibrillar meshwork mass. The extracellular matrixes in the anterior capsule of anterior subcapsular cataracts were immunohistochemically positive for fibronectin, laminin, collagen type I, and collagen type IV. CONCLUSIONS: Lens epithelial cells in different types of cataracts have distinct cellular characteristics and may possess a bipotential nature with the ability to transdifferentiate into mesenchymal cells. This may be an underlying mechanism for the development of cataract and capsule opacification.

Adult↗
PubMed1999

Descending necrotizing mediastinitis: mediastinal drainage with or without thoracotomy.

Descending necrotizing mediastinitis (DNM) is a lethal process originating from odontogenic, pharyngeal, or cervical infections that descends along the fascial planes into the mediastinum. The surgical management ranges from cervical drainage to routine thoracotomy but remains controversial. We here describe two patients treated successfully who underwent cervical drainage alone or cervical drainage combined with thoracotomy. Wide cervical exploration with postural drainage was effective in one patient with limited DNM above the carina. Mediastinal exploration through thoracotomy was required to salvage the other with DNM extending below the carina and associated with pericardial invasion.

Adult↗
PubMed1999

Detection of Helicobacter DNA in bile from bile duct diseases.

Several species of Helicobacter colonize the hepatobiliary tract of animals and cause hepatobiliary diseases. The aim of this study is to investigate Helicobacter found in the biliary tract diseases of humans. Thirty-two bile samples (15 from bile duct cancer, 6 from pancreatic head cancer, and 11 from intrahepatic duct stone) were obtained by percutaneous transhepatic biliary drainage. Polymerase chain reaction analysis using Helicobacter specific urease A gene and 16S rRNA primers, bile pH measurement, and Helicobacter culture were performed. Helicobacter DNA was detected in 37.5%, and 31.3% by PCR with ureA gene, and 16S rRNA, respectively. The bile pH was not related to the presence of Helicobacter. The cultures were not successful. In conclusion, Helicobacter can be detected in the bile of patients with bile duct diseases. The possibility of pathogenesis of biliary tract diseases in humans by these organisms will be further investigated.

Adenocarcinoma↗
PubMed1998

A dose-response relationship between exposure to cockroach allergens and induction of sensitization in an experimental asthma in Hartley guinea pigs.

OBJECTIVE: An indoor allergen, cockroach allergen (CRa) has been partly implicated in the rising prevalence of inner-city asthma. This study investigates a dose-response relationship of exposure to CRa with the degree of sensitization and with airway inflammation through the use of our established guinea pig asthma model. METHODS: Four groups of Hartley guinea pigs were exposed to aerosolized saline (control) and three dose levels of CRa: low-dose, 0.5 mg (LD); medium-dose, 5 mg (MD); or high-dose, 25 mg (HD), nebulized twice a day, 5 days per week, for 4 weeks. The development of anaphylactic antibodies was measured by both allergy skin test and passive cutaneous anaphylaxis assay. Animals were challenged with CRa 5 days after the last sensitization, and specific airway resistance was measured continuously by a double-chamber plethysmograph while animals were in the conscious state. The inflammatory cells in bronchoalveolar lavage fluid (BALF) and the contractile responses of tracheal rings were analyzed in vitro at 24 hours after CRa challenge. RESULTS: The anaphylactic antibodies to CRa were detected in the CRa-sensitized animals by allergy skin test. Passive cutaneous anaphylaxis titers of IgG1a-like antibody were zero in control, 1:2 in LD, 1:40 in MD, and 1:160 in HD. Total leukocytes in BALF were increased by CRa challenge in all three CRa-sensitized groups compared with control (p < 0.0001). The tracheal rings from CRa-sensitized guinea pigs constricted upon addition of incremental doses of CRa challenge in vitro in a dose-responsive manner (p < 0.0001). The leukocytosis in BALF and the anaphylactic contractile responses of the tracheal rings in CRa-sensitized groups were correlated to the levels of CRa to which the groups had been exposed during sensitization (p < 0.001). CRa-provoked increase in SRaw was noted in all three groups of the CRa-sensitized guinea pigs compared with control (p < 0.01). Yet, among CRa-sensitized groups, a greater increase in specific airway resistance was noted in the LD group but not in the HD CRa group. CONCLUSIONS: The development of anaphylactic cockroach sensitivity in guinea pigs was dependent on the levels of CRa exposure during sensitization, and the CRa-sensitized animals showed antigen-specific airway inflammation along with airway smooth muscle contractions. However, the severity of bronchospasm in conscious animals was not in agreement with the degree of CRa sensitivity.

Allergens↗
PubMed1998

Contractile responses to allergen and cholinergic stimulation in bronchus and trachea of cockroach allergen-sensitized guinea pigs.

Airway hyperreactivity is a hallmark of asthma. Yet, the role of allergic sensitization in the hyperreactivity remains controversial. This study examined the effects of airborne cockroach allergen (CRa) sensitization on the contractility of bronchial (BSM) and tracheal (TSM) smooth muscle rings to cholinergic stimulations, and to specific antigen, in vitro. Guinea pigs were actively immunized with CRa, 5 mg (high dose, HD), 0.5 mg (low dose, LD), or saline aerosols (2x/day, 5 days/week, for 4 weeks) and challenged by CRa inhalation 5 days after last exposure. Twenty-four hours postchallenge, the contractions of the TSM and BSM to electrical field stimulation (EFS), acetylcholine (ACh), and to CRa were measured in vitro. In addition, the contraction to these stimuli were also examined in the passively sensitized TSM with the sera of CRa-immunized guinea pigs. The contractile responses of actively immunized and passively sensitized tissues to EFS and ACh were very similar to those of control tissues. CRa induced dose-dependent contractions in both actively immunized and passively sensitized, but not in control, tissues. The CRa-induced contraction was stronger in the HD group than in the LD group (p<0.0001). Leukotriene C4/D4 receptor antagonist LY-171883 inhibited the CRa-induced contraction by 86% in actively immunized TSM, and by 9% in the passively sensitized TSM. Pyrilamine inhibited the contraction by 57% in actively immunized TSM and 70% in passively sensitized TSM. The results indicate that CRa sensitization does not cause increased airway smooth muscle contractility to cholinergic stimulations, but induces antigen-specific contractions in vitro. Leukotrienes appear to play a significant role in the CRa-specific contractions, more in the actively immunized than those in the passively sensitized tissues, while histamine exerts a moderate effect on the CRa-induced contractions.

Acetophenones↗
PubMed1998

Serum levels of soluble interleukin-2 receptor at acute asthma exacerbation: relationship with severity of exacerbation and bronchodilator response.

BACKGROUND: T lymphocytes play a central role in the regulation of airway inflammation in asthma, and T cell activation appears to be a characteristic feature of acute asthma. It is not clear, however, whether this is proportional to the severity of acute asthma and is directly related to airway inflammation relevant to airflow obstruction during acute asthma. It is presumed that the extent to which bronchoconstriction or inflammation contributes to airflow obstruction in acute asthma may determine responsiveness to bronchodilator therapy. METHODS: Fifty asthmatic children who visited the emergency room due to acute exacerbation were studied. Serum levels of soluble interleukin-2 receptor (sIL-2R), a marker of T cell activation, were measured at the time of acute exacerbation and of clinical remission. At acute exacerbation, FEV1 was assessed before and after the administration of aerosolized salbutamol. RESULTS: The mean (+/-SD) serum level of sIL-2R at acute exacerbation (854+/-248 U/ml) was significantly higher (p<0.01) than at clinical remission (676+/-211 U/ml). It correlated positively with the severity of exacerbation (r = 0.47, p<0.01), but showed no significant relationship with bronchodilator response (r = -0.17, p = 0.20). CONCLUSION: A higher serum level of sIL-2R at acute exacerbation was associated with more severe exacerbation but not with lower bronchodilator response. These findings suggest that in the context of acute asthma, T cell activation is proportional to disease activity, but its relationship to airway inflammation relevant to the genesis of airflow obstruction remains obscure.

Acute Disease↗
PubMed1998

Peripapillary atrophy in normal and primary open-angle glaucoma.

This study was undertaken in order to determine the value of measuring peripapillary atrophy for the diagnosis and follow-up of patients with glaucoma, and to evaluate how closely peripapillary atrophy is related to structural and functional optic nerve damage in glaucoma. Magnification-corrected morphometry of photographs using a computer graphic program and automated static threshold perimetry were performed in 234 eyes of 141 patients with primary open-angle glaucoma and 139 eyes of 86 normal subjects. The groups were not significantly different in age, refractive error or disc area. Zones alpha and beta were significantly larger, total peripapillary atrophy was significantly more extensive, and zone beta occurred more often in the glaucoma group than in the normal group. The frequency of zone beta increased with advancing glaucoma stage. The areas of zones alpha and beta and total peripapillary atrophy increased significantly with decreasing rim/disc area ratio, rim area, and mean deviation, and with increasing vertical and horizontal cup-to-disc ratios and cup area. Correlation coefficients were generally higher for zone beta than for zone alpha. Peripapillary atrophy was greater in a sector in which the neuroretinal rim loss was more marked. These findings suggest that increases in the extent of peripapillary atrophy are related to the severity of glaucomatous optic nerve damage and visual field defects, and that peripapillary atrophy is useful for the diagnosis and progression of glaucomatous nerve damage.

Chi-Square Distribution↗
PubMed1998

Detection of Cryptosporidium oocysts in canine fecal samples by immunofluorescence assay.

Fecal samples were collected from 257 dogs in four areas in Korea during the period of January 1996 to November 1997 and examined by immunofluorescence assay for Cryptosporidium oocysts using a commercial diagnostic kit (Meridian Diagnostics, Cincinnati, Ohio). Of the 257 samples, 25 (9.7%) were positive for Cryptosporidium. Differences were noted in the prevalence of canine cryptosporidiosis in both areas and dog types. The results provide a further evidence of environmental contamination and widespread distribution of the parasite in Korea.

Animals↗
PubMed1998

Mechanisms of relaxation of coronary artery by hypoxia.

This study was designed to clarify the dependency of hypoxic coronary vasodilation (HCD) on the endothelium and the role of the K+ channels on HCD in the rabbit coronary artery. HCD was investigated in an isolated left circumflex coronary artery precontracted with prostaglandin F2 alpha. Vascular rings were suspended for isometric tension recording in an organ chamber filled with Krebs-Henseleit (KH) solution. Hypoxia was induced by gassing the chamber with 95% N2 + 5% CO2 and was maintained for 15 approximately 25 min. Hypoxia elicited a vasodilation in the precontracted coronary artery with and without endothelium. There was no difference between the amplitude of the HCD induced by two consecutive hypoxic challenges and the effects of 20% O2 + 5% CO2 + 75% N2 and 95% O2 + 5% CO2 control K-H solution of subsequent responses to hypoxia. Inhibition of the cyclooxygenase pathway by treatment with indomethacin had no effect on HCD. Blockades of the tetraethylammonium chloride-sensitive K+ channel abolished HCD. Apamin, a blocker of the small conductance Ca(2+)-activated K+ (KCa) channel, and iberiotoxin, a blocker of the large conductance KCa channel had no effect on HCD, respectively. Glibenclamide, a blocker of the ATP-sensitive K+ (K+ATP) channel, reduced HCD. Cromakalim, an opener of the K+ATP channel, relaxed the coronary artery precontracted with prostaglandin F2 alpha. The degree of relaxation by cromakalim was similar to that by hypoxia while glibenclamide reduced both hypoxia- and cromakalim-induced vasodilatations. In conclusion, these results suggest that HCD is independent on endothelium and HCD is considered to be induced by activation of K+ATP channel.

Animals↗
PubMed1997

Roles of CD9 molecules in survival and activation of human eosinophils.

CD9 is a cell surface glycoprotein belonging to the transmembrane 4 superfamily. In this report, we demonstrate that cross-linking CD9 with different forms of mAb activates distinct functions of human eosinophils. Anti-CD9 mAb (clone ALB6) immobilized onto tissue culture plates induced eosinophil degranulation. This effect of anti-CD9 mAb (clone ALB6) was unique because other immobilized clones of anti-CD9 mAb (clones FMC56 and ML13) or anti-HLA Class I mAb failed to induce degranulation. In addition, neutrophil degranulation was not provoked by the immobilized clone ALB6, consistent with a lack of expression of CD9 on neutrophils. Eosinophil degranulation induced by anti-CD9 mAb (clone ALB6) was abolished by pretreatment of eosinophils with anti-CD18 mAb, suggesting that beta2 integrins are involved in the reaction. In contrast to the results with immobilized clones, all clones of anti-CD9 mAb in soluble form enhanced eosinophil survival. This enhanced survival was inhibited by anti-granulocyte-macrophage-CSF (GM-CSF) mAb, suggesting that autocrine production of GM-CSF by eosinophils mediated the enhanced survival. In fact, by ELISA and RT-PCR, GM-CSF protein and mRNA were detected in supernatants and cell lysates of eosinophils stimulated by soluble anti-CD9 mAb, but not by immobilized mAb. These results indicate that CD9 serves as a molecule that delivers stimulation signals on eosinophils. The eosinophil's cellular responses may differ and be dependent on the manner of receptor ligation.

Antigens, CD↗
PubMed1997

Floral homeotic genes were recruited from homologous MADS-box genes preexisting in the common ancestor of ferns and seed plants.

Flowers sensu lato are short, specialized axes bearing closely aggregated sporophylls. They are typical for seed plants (spermatophytes) and are prominent in flowering plants sensu stricto (angiosperms), where they often comprise an attractive perianth. There is evidence that spermatophytes evolved from gymnosperm-like plants with a fern-like mode of reproduction called progymnosperms. It seems plausible, therefore, that the stamens/carpels and pollen sacs/nucelli of spermatophytes are homologous to fern sporophylls and sporangia, respectively. However, the exact mode and molecular basis of early seed and flower evolution is not yet known. Comparing flower developmental control genes to their homologs from lower plants that do not flower may help to clarify the issue. We have isolated and characterized MADS-box genes expressed in gametophytes and sporophytes of the fern Ceratopteris. The data indicate that at least two different MADS-box genes homologous to floral homeotic genes existed in the last common ancestor of contemporary vascular plants, some descendants of which underwent multiple duplications and diversifications and were recruited into novel developmental networks during the evolution of floral organs.

Amino Acid Sequence↗
PubMed1996

Efficacy of closantel against Fasciola hepatica in Korean native goats.

Closantel (Flukiver), a salicylanilide antiparasitic compound, was tested in Korean native goats infected with Fasciola hepatica. The goats were administered closantel once orally at a dose of 10 mg/kg body weight. Efficacy was monitored weekly by fecal examination of all infected animals starting the second week post-treatment and continuing for 3 weeks. Closantel elicited 80.3, 97.8 and 92.7% efficacy in goats with naturally-acquired fasciolosis at the second, third and fourth week post-treatment, respectively. It elicited a 100% efficacy in goats experimentally infected with F. hepatica metacercariae and treated at 18 weeks post-infection.

Animals↗
PubMed1996

Classification and phylogeny of the MADS-box multigene family suggest defined roles of MADS-box gene subfamilies in the morphological evolution of eukaryotes.

The MADS-box encodes a novel type of DNA-binding domain found so far in a diverse group of transcription factors from yeast, animals, and seed plants. Here, our first aim was to evaluate the primary structure of the MADS-box. Compilation of the 107 currently available MADS-domain sequences resulted in a signature which can strictly discriminate between genes possessing or lacking a MADS-domain and allowed a classification of MADS-domain proteins into several distinct subfamilies. A comprehensive phylogenetic analysis of known eukaryotic MADS-box genes, which is the first comprising animal as well as fungal and plant homologs, showed that the vast majority of subfamily members appear on distinct subtrees of phylogenetic trees, suggesting that subfamilies represent monophyletic gene clades and providing the proposed classification scheme with a sound evolutionary basis. A reconstruction of the history of the MADS-box gene subfamilies based on the taxonomic distribution of contemporary subfamily members revealed that each subfamily comprises highly conserved putative orthologs and recent paralogs. Some subfamilies must be very old (1,000 MY or more), while others are more recent. In general, subfamily members tend to share highly similar sequences, expression patterns, and related functions. The defined species distribution, specific function, and strong evolutionary conservation of the members of most subfamilies suggest that the establishment of different subfamilies was followed by rapid fixation and was thus highly advantageous during eukaryotic evolution. These gene subfamilies may have been essential prerequisites for the establishment of several complex eukaryotic body structures, such as muscles in animals and certain reproductive structures in higher plants, and of some signal transduction pathways. Phylogenetic trees indicate that after establishment of different subfamilies, additional gene duplications led to a further increase in the number of MADS-box genes. However, several molecular mechanisms of MADS-box gene diversification were used to a quite different extent during animal and plant evolution. Known plant MADS-domain sequences diverged much faster than those of animals, and gene duplication and sequence diversification were extensively used for the creation of new genes during plant evolution, resulting in a relatively large number of interacting genes. In contrast, the available data on animal genes suggest that increase in gene number was only moderate in the lineage leading to mammals, but in the case of MEF2-like gene products, heterodimerization between different splice variants may have increased the combinatorial possibilities of interactions considerably. These observations demonstrate that in metazoan and plant evolution, increased combinatorial possibilities of MADS-box gene product interactions correlated with the evolution of increasingly complex body plans.

Amino Acid Sequence↗
PubMed1996

Transaxillary minithoracotomy versus video-assisted thoracic surgery for spontaneous pneumothorax.

BACKGROUND: Although management of spontaneous pneumothorax by video-assisted thoracic surgery (VATS) has generally shown superior clinical results to thoracotomy, management of spontaneous pneumothorax by transaxillary minithoracotomy (TAMT) has also shown good clinical results. The objective of this study was to compare the clinical results of VATS and TAMT in treating spontaneous pneumothorax. METHODS: Sixty-six patients, aged 13 to 81 years, with recurrent, persistent or contralateral spontaneous pneumothorax were involved in this study. Thirty-six patients were treated by VATS and 30 by TAMT. The operating time, the amount of analgesics used on the first postoperative day, the duration of the indwelling chest tube, and the number of recurrences after operation were compared. The follow-up periods of both procedures were from 6 to 24 months. RESULTS: Of the 66 patients, 64 were male and 2 were female. The duration of operation, from start of skin incision to insertion of chest tube, was 91.2 +/- 36.8 minutes in VATS and 86.3 +/- 40.9 minutes in TAMT (p = 0.6061). The amount of analgesics (keptoprofen) used was 1.9 +/- 2.3 ampules in VATS and 2.1 +/- 2.9 ampules in TAMT (p = 0.0883). The duration of indwelling chest tube was 5.0 +/- 4.0 days in VATS and 4.3 +/- 2.1 days in TAMT (p = 0.3707). The number of recurrences after operation was 4 in VATS and none in TAMT. CONCLUSIONS: There were no advantages of VATS over TAMT for management of recurrent, persistent, or contralateral spontaneous pneumothorax in regard to the operating time, the amount of analgesics used on the first postoperative day, the duration of the indwelling chest tube, and the number of postoperative recurrences in patients with apical bullae.

Adolescent↗
PubMed1996

Effect of cholera toxin on glucose absorption and net movements of water and electrolytes in the intestinal loop of sheep.

This study was designed to evaluate the effect of cholera toxin on glucose absorption and net movement of water and electrolytes in the jejunal loop of sheep. Intraluminal perfusion was performed at the rate of 1 ml/min with isotonic 10 mM glucose solution. Osmolality was adjusted by adding NaCl, and the outflow solution was collected every 10 min. After a 30 min control period, cholera toxin was applied intraluminally for 30 min at doses of 30, 60, and 120 micrograms/loop. In the control period, water, sodium and chloride were absorbed, while potassium and bicarbonate were secreted. Cholera toxin reversed the net absorption of water, sodium and chloride to net secretions, and this secretory response to cholera toxin was dose-dependent. Bicarbonate secretion was stimulated dose-dependently by cholera toxin. Potassium secretion was also increased at all doses, though this response was not dose-dependent. The net glucose absorption was decreased dose-dependently by cholera toxin. In conclusion, these results indicate that cholera toxin stimulates water and electrolyte secretion, and inhibits glucose absorption in the jejunal loop of sheep.

Animals↗