Biomedical subjects

J W Kim

Publications and source records attributed to J W Kim.

At least 91 records · Page 5Linked to original sources

PubMed2001

Biochemical confirmation and characterization of the family-57-like alpha-amylase of Methanococcus jannaschii.

The gene encoding a family-57-like alpha-amylase in the hyperthermophilic archaeon Methanococcus jannaschii, has been cloned into Escherichia coli. Extremely thermoactive alpha-amylase was confirmed in partially purified enzyme solution of the recombinant culture. This enzyme activity had a temperature optimum of 120 degrees C and a pH optimum 5.0-8.0. The amylase activity is extremely stable against denaturants. Hydrolysis of large sugar polymers with alpha-1-6 and alpha-1-4 linkages yields products including glucose polymers of 1-7 units. Highest activity is exhibited on amylose. The catalyst exhibited a half-life of 50 h at 100 degrees C, among the highest reported thermostabilities of natural amylases.

Amino Acid Sequence↗

PubMed2001

Novel, thermostable family-13-like glycoside hydrolase from Methanococcus jannaschii.

A novel glycoside hydrolase from the hyperthermophilic archaeon Methanococcus jannaschii has been cloned into Escherichia coli. Extremely thermoactive and thermostable amylolytic activity was confirmed in partially purified enzyme solution. This enzyme exhibited a temperature optimum of 100 degrees C and a pH optimum pH 5.0-8.0. Hydrolysis of large 1,6-alpha- and 1,4-alpha-linked polysaccharides yielded glucose polymers of 1-7 units. Incubation with amylose displayed the highest activity. The catalyst was activated and stabilized by Ca2+ and exhibited extreme thermostability at 100 degrees C with a half-life of 78 h.

Amino Acid Sequence↗

PubMed2001

Comparison of the efficacy and safety of different formulations of omeprazole-based triple therapies in the treatment of Helicobacter pylori-positive peptic ulcer.

Little is known about the efficacy and safety of different formulations of omeprazole-based triple therapy regimens for the treatment of Helicobacter pylori-positive peptic ulcer. We compared the efficacy and safety of two formulations of omeprazole used in triple therapies in patients with H. pylori-positive active peptic ulcer. Seventy-four patients with endoscopically proven H. pylori-positive active peptic ulcer were randomized to two groups, each with 37 patients, to receive either OAC-I (6 weeks of "A" formulation of omeprazole [20 mg twice daily] plus 2 weeks of amoxicillin [1.0 g twice daily] and clarithromycin [500 mg twice daily] or OAC-II (6 weeks of "B" formulation of omeprazole [20 mg twice daily] plus 2 weeks of the same antibiotics. The H. pylori and ulcer healing status were assessed at the baseline and at the 6-week endpoint of therapy. Gastrointestinal symptoms, documentation of adverse events, and standard laboratory examinations were assessed at each visit. Eradication of H. pylori (intention to treat [n = 74]/per protocol [n = 66]) and healing of the ulcer were successful in 83.8%/96.9% and 93.8%, respectively, of the OAC-I group patients, and in 91.9%/100% and 97.1%, respectively, of the OAC-II group patients (P = 0.477; P = 0.608). The OAC-I group experienced rapid resolution of symptoms, but no significant differences were found between the two groups for number of days taken for resolution of gastrointestinal symptoms, adverse events, and laboratory findings. The two different formulations of omeprazole used in triple therapy regimens produced similar efficacy and safety results after 6 weeks of treatment in patients with H. pylori-positive active peptic ulcer.

Adult↗

PubMed2001

Serum melanotransferrin, p97 as a biochemical marker of Alzheimer's disease.

The protein melanotransferrin (p97) is associated with the brain lesions of Alzheimer's disease (AD) and is a potential marker of the disorder. We measured serum p97 concentrations in 211 subjects: 71 patients with AD, 56 patients with non-AD-type dementia, and 84 normal control subjects. Serum p97 concentrations were elevated 3- to 4-fold in AD (median 15.00 pg/microl, interquartile range 10.20-17.00 pg/microl) as compared to non AD dementia (2.85 pg/microl, 1.93-7.15 pg/microl) and normal controls (3.20 pg/microl, 2.55-3.95 pg/microl). The mean elevation was significant at 13.54 +/- 3.72 pg/microl, even in the 38 subjects with mild AD (CDR stage 0.5-1). Receiver operating characteristic analyses confirmed an optimal diagnostic threshold of 10.0 pg/microl, which yielded over-all accuracy of 0.882 to 0.915. Serum p97 is a candidate marker of AD, even in the early stage when clinical diagnosis is most uncertain.

Adult↗

PubMed2001

Molecular cloning and high-level expression of G2 protein of hantaan (HTN) virus 76-118 strain in the yeast Pichia pastoris KM71.

Hantaan viral G2 envelope gene, which is known to be one of major antigens and induce neutralizing antibodies, was cloned into expression vector pHIL-S1 which consists of AOX1 promoter, PHO1 signal sequence, HIS4 gene and other components. The recombined plasmid was transformed into methylotropic yeast, Pichia pastoris of KM71 and recombinant strains harboring multi-copy of G2 gene were selected. Expression of the cloned G2 gene was confirmed with Western blot analysis using anti-sera of guinea pig immunized with the carboxyl terminal region of G2 protein expressed in Escherichia coli. The expression of G2 gene from the recombinant strain was tightly repressed by dextrose and effectively induced by methanol, an inducer of AOX1 promoter. The highest expression level was observed from 1 day after induction and maintained at the same level for up to 4 days.

Animals↗

PubMed2001

Fluoxetine enhances cell proliferation and prevents apoptosis in dentate gyrus of maternally separated rats.

The mother-infant relationship is an instinctive phenomenon, and loss of maternal care in early life influences neonatal development, behavior and physiologic responses.(1,2) Furthermore, the early loss may affect the vulnerability of the infant to neuropsychiatric disorders, such as childhood anxiety disorders, personality disorders and depression, over its lifespan.(3,4) Fluoxetine is prescribed worldwide for depression and is often used in the treatment of childhood mental problems related to maternal separation or loss of maternal care.(5,6) In the present study, fluoxetine was administrated to rats with maternal separation to determine its effects on neuronal development, in particular with respect to cell proliferation and apoptosis in the dentate gyrus of the hippocampus. Rat pups were separated from their mothers and socially isolated on postnatal day 14 and were treated with fluoxetine (5 mg kg(-1)) and 5-bromo-2'-deoxyuridine (BrdU) (50 mg kg(-1)) for 7 days, after which immunohistochemistry and a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining were carried out. In the pups with maternal separation treated with fluoxetine, the number of BrdU-positive cells was significantly increased and that of TUNEL-positive cells was significantly decreased in the dentate gyrus compared to pups with maternal separation that did not receive fluoxetine treatment. These findings indicate that fluoxetine affects new cell proliferation and apoptosis, and we propose that fluoxetine may be useful in the treatment of maternal separation-related diseases.

Animals↗

PubMed2001

Ultrasound diagnosis of postpartum ovarian vein thrombosis: case report.

Postpartum ultrasound investigation of a woman with unremitting fever and right flank pain after Cesarean section revealed an extensive thrombosis of the right ovarian vein which extended into the inferior vena cava. Computed tomography was required to substantiate the diagnosis. Medical treatment with intravenous urokinase and heparin and antibiotics was successfully performed. During the postpartum period, the possibility of ovarian vein thrombosis should be considered in febrile patients with abdominal pain who are not responding to antibiotics, and imaging studies such as ultrasound and computed tomography should be performed early for prompt diagnosis and therapy.

Adult↗

PubMed2001

Distribution of HLA-A, B alleles and polymorphisms of TAP and LMP genes in Korean patients with atopic dermatitis.

BACKGROUND: Atopic dermatitis has been seen to result from multifactorial inheritance, with interaction between genetic and environmental factors. The genetic association may differ according to the ethnic backgrounds. OBJECTIVE: The purpose of this study was to investigate the genetic factors in Korean atopic dermatitis patients by studying the human leucocyte antigen (HLA) class I association and polymorphisms of transporters associated with antigen presentation (TAP) and low-molecular-weight polypeptide (LMP) genes. METHODS: HLA-A and B genotyping was performed in 53 atopic dermatitis patients and 184 healthy controls using the standard microlymphocytotoxicity technique. TAP1, TAP2, LMP2, and LMP7 gene polymorphisms were anaylzed using the polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP), PCR-amplification refractory mutation system (ARMS), and PCR-restriction fragment length polymorphism (RFLP). RESULTS: Allele frequency of HLA-A24 was significantly increased in patients with atopic dermatitis compared to controls (P < 0.05). HLA-B alleles showed no differences in distribution between patients and controls. Genotype, phenotype, and allele frequencies of TAP1 gene also revealed no differences in distribution between patients and controls. Analysis of TAP2 gene polymorphisms showed increased frequencies of the TAP2*C allele and TAP2*A/TAP2*C genotype in atopic dermatitis patients compared to controls (P < 0.05). Distribution of LMP2 and LMP7 gene polymorphisms was similar for patients and controls. CONCLUSION: This study demonstrates an association of atopic dermatitis with HLA-A24 and TAP2*C alleles in Korean patients. Discrepancy with the previous reports might be related to different patient characteristics and ethnic variations.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

The effects of thiol compounds and ebselen on nitric oxide activity in rat aortic vascular responses.

1. Thiols have been implicated to play a role in a variety of aspects of nitric oxide (NO) generation and activity. Thiol dependence of nitric oxide synthase (NOS) has remained controversial and its mechanism is not clear. This study investigates possible mechanisms between thiol (SH group) and NOS activation, through thiol compounds (glutathione, dithiothreitol, N-acetyl-L-cysteine) and Ebselen [2-phenyl-1,2-benzisoselenazole-3(2H)-one] on rat aortic vascular responses. 2. In rat thoracic aorta, acetylcholine (10(-6)-10(-9) M) induced a relaxation of phenylephrine (PE) (10(-7) M)-induced tone, which was inhibited dose dependently by increasing concentration of ebselen (1-10 microM). 3. In rings of rat thoracic aorta, ebselen and NOS inhibitors (NG-monomethyl-L-arginine, NG-nitro-L-arginine methyl ester) produced an augmentation of phenylephrine (10(-7) M)- induced tone and acetylcholine induced a relaxation of PE (10(-7) M)-induced tone in rat thoracic aorta, which was inhibited by ebselen (10 microM) like NOS inhibitor. 4. The thiol compounds (glutathione, dithiothreitol, and N-acetyl-L-cysteine) alone did not change vascular tone in rat thoracic aorta. Pretreatment with thiol compounds before ebselen treatment, however, reversed the inhibitory effect of ebselen which acts like the NOS inhibitor in rat thoracic aorta. Posttreatment with thiol compounds after ebselen treatment did not reverse the inhibitory effect of ebselen by as much as pretreatment. 5. Calcium ionophore A23187 (10(-7) M)-induced vasodilation was inhibited in ebselen pretreated rat thoracic aorta, but sodium nitroprusside (SNP, 10(-7) M)-induced relaxation was not inhibited by ebselen. This suggests that NOS is involved in the inhibitory effect of ebselen on rat thoracic aorta relaxation. 6. These results suggest that ebselen exerts an inhibitory action on the nitric oxide synthesis in rat thoracic aorta by interacting with thiol groups.

Acetylcholine↗

PubMed2001

CYP2D6*4 polymorphism is not associated with Parkinson's disease and has no protective role against Alzheimer's disease in the Korean population.

CYP2D6*4 polymorphism is reported to be associated with Parkinson's disease (PD) and to have protective role against Alzheimer's disease (AD). Such findings are not extensively studied in the Oriental population, especially Koreans. The effects of CYP2D6*4 polymorphism on AD and PD were investigated by polymerase chain reaction-restriction fragment length polymorphism in Korean subjects. Heterozygous mutant allele was found in four of 93 patients with PD, 0 of 32 patients with AD and one of 121 control subjects (59 stroke, 59 normal controls and four other psychiatric disorders), but no homozygous mutant allele was found. There were no statistically significant differences between the AD group and controls, and between the PD group and controls. In conclusion, we suggest that CYP2D6*4 polymorphism does not confer susceptibility to PD in the Korean population. Also, due to such a rare occurrence of the CYP2D6*4 polymorphism, we can not confirm the protective role of the polymorphism against AD in the Korean population.

Aged↗

PubMed2001

Polymorphism of TP53 codon 72 and the risk of cervical cancer among Korean women.

OBJECTIVE: It has recently been suggested that white women who are homozygous for the allele of the gene for wild-type p53 protein (TP53) that encodes arginine at position 72 are more susceptible to human papillomavirus-associated cervical carcinoma than are women who are heterozygous for this polymorphism and women who are homozygous for the allele that encodes proline at that position. This study was undertaken to analyze whether the TP53 codon 72 single-nucleotide polymorphism might be correlated with the risk of cervical cancer among Korean women. STUDY DESIGN: Peripheral blood samples from patients with invasive cervical carcinoma yielding a positive result for human papillomavirus 16 (n = 100), patients with cervical intraepithelial neoplasia grade III (n = 134), and healthy control subjects (n = 100) were examined. The presence and genotype of human papillomavirus in cancerous cervical tissues were determined by E6, E7-based nested polymerase chain reaction. Germline genomic deoxyribonucleic acid was extracted from peripheral blood leukocytes and examined by polymerase chain reaction amplification of the specific allele assay as described by Storey et al. Deoxyribonucleic acid samples from patients whose TP53 sequences had been determined by direct sequencing were used as positive control preparations. RESULTS: The respective proportions of individuals who are homozygous for the arginine allele, homozygous for the proline allele, and heterozygous for the 2 alleles were 40%, 12%, and 48% among women with invasive cervical carcinoma, 52%, 9%, and 39% among women with cervical intraepithelial neoplasia grade III, and 52%, 11%, and 37% among the control group. No significant differences in the frequency of codon 72 alleles were found among the 3 groups (chi(2) = 4.414; P =.353; degrees of freedom = 4). CONCLUSION: This finding suggests that the risk of cervical cancer may not be increased for Korean women with the allele of TP53 encoding arginine at codon 72.

Antibodies, Viral↗

PubMed2001

Extraction of metal values from manganese nodules in the ocean environment using zinc matte as a reductant.

The leaching process of manganese nodules in the marine environment is significant in the recovery of several metal values. In this experiment, reduction leaching of manganese nodules was carried out using zinc matte as a reductant in dilute HCl solution. The leaching characteristics of Mn, Co, Ni, and Cu from manganese nodules depended on the leaching temperature and initial HCl concentration. A temperature of approximately 70 degrees C was suitable for the present reduction leaching, and the extraction rate increased with increase in the initial HCl concentration. More than 97% of Mn, 92% of Co, and 88% of Ni were easily extracted. The dissolution of Mn, Co, Ni, and Cu depended upon the amount of zinc matte added. The ratio of liquid and solid was also an important factor in the extraction of manganese nodules. As the liquid/solid (L/S, lixiviant/manganese nodule) ratio was increased, the extraction rate increased. The extraction rate was independent of stirring speed.

Conservation of Natural Resources↗

PubMed2001

Inhibitory effects of mast cell-mediated allergic reactions by cell cultured Siberian Ginseng.

The crude drug "Siberian Ginseng (SG)" has long been used in empirical Oriental medicine for the nonspecific enhancement of resistance in humans and animals. In this study, we investigated the effect of cell cultured SG by oral administration in mast cell-mediated allergic reactions. SG dose-dependently inhibited compound 48/80-induced systemic allergy with doses of 10(-2) to 1 g/kg 1 h before oral administration. Of special note, SG inhibited systemic allergy with the dose of 1 g/kg by 25%. SG (1 g/kg) also inhibited passive cutaneous allergic reaction by 51%. SG dose-dependently inhibited histamine release from rat peritoneal mast cells. When SG (0.01 mg/ml) was added, the secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 in antidinitrophenyl (DNP) IgE antibody-stimulated mast cells was inhibited 39.5% and 23.3%, respectively. In addition, SG inhibited anti-DNP IgE antibody-stimulated TNF-alpha protein expression in mast cells. Our studies provide evidence that SG may be beneficial in the treatment of various types of allergic diseases.

Anaphylaxis↗

PubMed2001

Age-related increase of brain cyclooxygenase activity and dietary modulation of oxidative status.

Several studies have demonstrated that inhibitors of cyclooxygenase (COX) attenuate various neuronal injuries and age-dependent demented conditions. From these findings, we proposed to test the effect of age on COX activity and its possible suppression by the antiaging action of dietary restriction in the rat brain. The status of reactive oxygen species (ROS) was also assessed to correlate with COX activity to delineate the underlying mechanism of the altered COX activity during aging. These results showed that COX activity significantly increased in 24-month-old rats compared with 6-month-old rats in an ad libitum group. Interestingly, mRNA and protein levels of COX-2 showed little corresponding age-related change. The formation of ROS was found to increase gradually with age in ad libitum fed rats. However, dietary restriction suppressed the increase at the age of 24 months. To substantiate the relationship between ROS and COX activity when the rats were 24 months of age, we conducted in vitro experiments with a C6 glioma cell line. Together, it is concluded that increased COX activity with age is due to the activation of COX catalytic reaction by ROS without increased gene expression of COX-2 and that it is related to the increased pro-oxidant status in aged rats.

Age Factors↗

PubMed2001

Gene expression of cyclooxygenase in the aging heart.

Cyclooxygenase (COX) is the key rate-limiting enzyme in the prostaglandin synthetic pathway. Two isoforms of COX have been identified: a constitutive COX-1 and an inducible COX-2, which is activated in response to various stimuli. We investigated the changes of COX-1 and COX-2 in rat heart during aging. We measured the age-related changes in the mRNA and protein levels of COX by using reverse-transcription polymerase chain reaction and Western blotting, respectively. COX-2 mRNA and protein levels increased with age, whereas those of COX-1 showed no change. The COX activity determined by prostaglandin E(2) production increased with age. Because the COX-catalyzed arachidonate cascade is an important source of reactive oxygen species (ROS) generation, changes in ROS generation and lipid peroxidation were also assessed. The amount of ROS generated by the COX pathway increased with age, as did the total ROS generation and lipid peroxidation. These results show that COX-2 activity increases with age, partially because of elevated transcriptional expression and protein content, and they suggest that increased COX-2 can play a role in oxidative alterations in the aged heart.

Aging↗

PubMed2001

Development of a breast self-examination program for the Internet: health information for Korean women.

Internet-based health information will enable us to interact with many people despite distance and time constraints. Informational media by computer is expected to become an important factor that affects health behavior. This study was done to develop an accessible multimedia program about breast self-examination on the Internet. This study was designed by using the two steps of need assessment and program development. For the need assessment step, a survey was carried out. The sample consisted of the 82 women of Yonsei University selected by convenient random sampling. At the program development step, screen design took into account perspectives of computer engineering. A storyboard for every screen was made via screen design and then ported to computer using the Netscape Navigator program. A breast self-examination program was developed using Netscape 4.0 on the Windows 98 platform. The multimedia program, including text, graphics, animation, and sound, was constructed with HTML language using Memo Sheet in Netscape Navigator. The contents of health information posted on the Internet included general information about breast cancer, the importance of breast self-examination, self-risk appraisal of breast cancer, the diverse methods about breast self-examination, the monthly check list graph, and social network for consultation. It is possible to interact with clients through the Question and Answer function on screen. This Internet-based health information program provides enough information, which can be accessed using search systems on the Internet.

Adult↗

PubMed2001

Plasma isocitrate dehydrogenase as a marker of centrilobular hepatic necrosis in patients with hyperthyroidism.

Isocitrate dehydrogenase (ICDH) may be useful for differentiating centrilobular from periportal necrosis in rats with liver injury. In this study, we assessed the usefulness of ICDH as a marker of centrilobular necrosis in patients with hyperthyroidism. Isocitrate dehydrogenase and alanine aminotransferase (ALT) activities were measured in the plasma of 56 patients with hyperthyroidism, 16 patients with chronic viral hepatitis (CVH), and 17 controls. Isocitrate dehydrogenase levels were higher in patients with hyperthyroidism than in those with CVH or in the controls (p < 0.01 and p < 0.001, respectively), even though ALT levels were higher in patients with CVH than in patients with hyperthyroidism (p < 0.01). Isocitrate dehydrogenase/ALT ratios were also higher in patients with hyperthyroidism than in those with CVH (p < 0.0001). Isocitrate dehydrogenase correlated to ALT levels in patients with hyperthyroidism or CVH (p < 0.05). In a patient with hyperthyroidism, ICDH levels decreased progressively to normal, and the ALT level and thyroid function were normalized. Thus, the plasma ICDH or ICDH/ALT ratio might be useful for differentiating centrilobular from periportal necrosis and for monitoring the degree of hepatic necrosis in patients with hyperthyroidism.

Adult↗

PubMed2001

Regulation of mucociliary motility by nitric oxide and expression of nitric oxide synthase in the human sinus epithelial cells.

OBJECTIVES: This study was performed to investigate the changes in ciliary beat frequency (CBF) after treatment with Larginine in the human sinus mucosa and to determine the distribution of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) in the healthy sinus mucosa. STUDY DESIGN/METHODS: CBF was measured in the sphenoid sinus mucosa of 12 patients who underwent trans-septal trans-sphenoidal hypophysectomy for the treatment of pituitary gland tumor. CBF was measured over 24 hours in Dulbecco's modified Eagle's medium (DMEM) after treatment with L-arginine, its inactive spatial isomer D-arginine, or an NOS inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME). DMEM without treatment with these materials was used as a control. Other pieces of the mucosa were exposed to L-NAME and its inactive spatial isomer D-NAME after preincubation with L-arginine. The specimens were immunohistochemically stained for iNOS and eNOS. RESULTS: CBF increased 24 hours after treatment with L-arginine as compared with control groups. CBF increased in proportion to the increasing concentrations of L-arginine. There was no significant change after treatment with D-arginine or L-NAME. CBF increased after treatment with L-arginine at 30 minutes and maintained for 24 hours. L-NAME inhibited the increase in CBF by L-arginine, but D-NAME showed no such effect. Immunoreactivity to both iNOS and eNOS was frequently observed in the ciliated epithelial cells and was stronger to eNOS than to iNOS. CONCLUSIONS: From the results of this study it is suggested that nitric oxide (NO) produced by iNOS and eNOS using L-arginine may increase CBF in the healthy sinus mucosa and that NO may have a regulatory function in ciliary motility in the human sinus mucosa.

Enzyme Induction↗