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S H Cho

Publications and source records attributed to S H Cho.

At least 73 records · Page 4Linked to original sources
PubMed2001

Bax gene disruption alters the epidermal response to ultraviolet irradiation and in vivo induced skin carcinogenesis.

Bcl-2 family member proteins are differentially expressed in skin and in non-melanoma skin cancer (NMSC). To elucidate the contribution of bcl-2 and bax proteins to epidermal differentiation and skin carcinogenesis, we investigated keratinocyte proliferation, differentiation and tumourigenesis in bcl-2(-/-) and bax(-/-) mice. The rate and pattern of proliferation and spontaneous cell death in the bcl-2(-/-) and bax(-/-) mice were not different from control mice. The epidermis of bcl-2(-/-) and bax(-/-) expressed sightly higher levels of cytokeratin 1 and loricrin compared to control littermates. The apoptotic response to ultraviolet-induced genotoxic stress was assessed by quantitating TUNEL positive cells. Bax(-/-) keratinocytes showed a significant resistance to UV-induced cell death compared to control mice. The life-span of bcl-2(-/-) mice precluded an assessment of bcl-2 gene disruption on in vivo tumourigenesis. A significant increase in tumour incidence was observed in bax(-/-) mice compared to control mice in two-step chemical carcinogenesis studies. These findings suggest that bcl-2 and bax gene products may be important determinants of normal keratinocyte differentiation and response to genotoxic stress in vivo, and indicate that bax may provide a tumour suppressor effect during skin carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

A case of hereditary angioedema associated with idiopathic hypoparathyroidism.

Hereditary angioedema is a rare autosomal dominant disease characterized by the edema of subcutaneous tissues, respiratory tract and bowel. It is caused by the deficiency of C1 esterase inhibitor. Hereditary angioedema may be associated with autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, autoimmune thyroiditis and glomerulonephritis. We report a 34-year-old male patient with hereditary angioedema who developed idiopathic hypoparathyroidism. Autoimmunity seems to be an important basis of this association and it might be caused by the immune dysfunction due to decreased level of complements; nevertheless, a casual association could not be excluded. To our knowledge, this is the first report of hereditary angioedema in association with idiopathic hypoparathyroidism in the medical literature.

Adult↗
PubMed2001

Linkage between bronchial responsiveness to methacholine and gene markers of IL-4 cytokine gene cluster and T-cell receptor alpha/delta gene complex in Korean nuclear families.

BACKGROUND: Several candidate genes have been reported to be linked to intermediate phenotypes of asthma in Caucasian populations. OBJECTIVE: To evaluate linkage between phenotypes of asthma and gene markers of high affinity IgE receptor-beta gene (D11S97), IL-4 cytokine gene cluster (IL-4R1), and T-cell receptor alpha/delta gene complex (D14S50) in Korean nuclear families. METHODS: Nuclear families (127 probands and their 130 siblings) for the linkage analysis were ascertained through asthmatic children. Linkages between total serum IgE response, skin responses to common aeroallergens, and bronchial responsiveness to methacholine were performed using a sib-pair approach. RESULTS: The square difference of the slope of the dose-response curve (DRS) between sib-pairs with two IL-4R1 identical alleles was smaller than with one or with neither IL-4R1 identical allele (P = 0.004). As for D14S50, the differences of DRS between sib-pairs with two identical alleles and with one identical allele were smaller than with neither identical alleles (P = 0.01). As for D11S97, no significant differences were observed among the groups with identical alleles of two, one or zero. With regard to total serum IgE levels, no significant linkage was found between this phenotype and the above three gene markers. As for skin responses to common aeroallergens, significant evidence was obtained to establish a linkage between this phenotype and the marker IL-4R1 (P = 0.01). However, no significant linkage was found between this phenotype and the markers D11S97 and D14S50. CONCLUSION: The expression of bronchial responsiveness to methacholine may be influenced by genetic factors in the IL-4 cytokine gene cluster and/or T-cell receptor alpha/delta gene complex, but the genetic influence of the FcepsilonRI-beta gene may be minimal in the expression of bronchial responsiveness in Korean nuclear families.

Adolescent↗
PubMed2001

HLA-DRB1*07 may have a susceptibility and DRB1*04 a protective effect upon the development of a sensitization to house dust mite Dermatophagoides pteronyssinus.

BACKGROUND: IgE responses to house dust mite-derived allergens seem to be the most important in the development of atopic asthma and rhinitis, but it has been difficult to demonstrate genetic control of the IgE response to the allergens. OBJECTIVE: This study was undertaken to investigate the association between sensitization to house dust mite, D. pteronyssinus (DP), and genotypes of HLA-DRB1 alleles. METHODS: DNAs were extracted from two groups of unrelated Koreans: (1) 178 with sensitization to DP; and (2) 99 age-matched non-atopic controls. Genotypes of the HLA-DRB1 alleles were determined using polymerase chain reaction (PCR)-based methods. RESULTS: The frequency of HLA-DRB1*07 was significantly increased in the DP-sensitive subjects compared with the controls (15.7% vs 4.0%, P = 0.009). Conversely, the frequencies of HLA-DRB1*04 and *14 were decreased in the DP-sensitive subjects compared with the controls (27.5% vs 45.5%, P = 0.002; 13.5% vs 24.2%, P = 0.02). Of the DRB1*04 alleles, DRB1*0403 was significantly decreased in the DP-sensitive subjects compared with the controls (3.9% vs 13.1%, P = 0.005). No significant differences were found in the distributions of the other HLA-DRB1 alleles between the two groups. CONCLUSION: HLA-DRB1*07 may have a susceptibility, and DRB1*04 and DRB1*14 may have a protective effect, upon the development of a sensitization to DP.

Adolescent↗
PubMed2001

Catalytic wet air oxidation of p-nitrophenol (PNP) aqueous solution using multi-component heterogeneous catalysts.

This study investigated the decomposition of high strength p-nitrophenol (PNP) of 2,000 mg/l (3,400 mg of COD/1,250 mg of TOC) by catalytic wet air oxidation. Multi-component heterogeneous catalysts were used as catalysts for this purpose. The study results using a batch reactor showed that catalyst "D" (Mn-Ce-Zr 22.4 g plus CuSO4 1.0 g; Mn-Ce-Zr-Cu [CuSO4]) was more effective (56-74%) than catalyst "A" (Mn-Ce-Zr 22.4 g) under the given conditions (O2 partial pressure of 1.0 MPa; temperature of 170-190 degrees C; 30 min of reaction time). The best result was obtained when 2 g of Mn-Ce-Zr-Cu [CuSO4] was used per 1L of PNP aqueous solution. COD and TOC removal efficiencies were 18% and 23% without catalysts during 20 min of reaction at 190 degrees C. They were improved to 79% and 71% with 2 g/L of Mn-Ce-Zr-Cu [CuSO4] under the same conditions. The ratio of BOD5/COD was measured to evaluate biodegradability. It was 0.05 without catalyst and increased to 0.33 with 2 g/L of Mn-Ce-Zr-Cu [CuSO4] for 20 min of reaction.

Catalysis↗
PubMed2000

Production of plasminogen activator inhibitor-1 by human mast cells and its possible role in asthma.

The plasminogen activator inhibitor type 1 (PAI-1) has an essential role in tissue remodeling. The PAI-1 gene was induced by a combination of phorbol ester and calcium ionophore at the highest level among the inducible human mast cell genes that we have analyzed on a DNA microarray. PAI-1 was secreted by both a human mast cell line (HMC)-1 and primary cultured human mast cells upon stimulation, whereas PAI-1 was undetectable in either group of unstimulated cells. The secretion of PAI-1 was due to de novo synthesis of PAI-1 rather than secretion of preformed PAI-1. The functional significance of PAI-1 secretion was demonstrated by complete inhibition of tissue-type plasminogen activator activity with supernatants of stimulated HMC-1 cells. Furthermore, we were able to regulate PAI-1 gene expression in HMC-1 cells by known therapeutic agents. High-dose (1 microM) dexamethasone induced PAI-1 mRNA expression. Cyclosporin down-regulated the expression of the PAI-1 gene. Cycloheximide abrogated PAI-1 mRNA expression, suggesting that transcription of the PAI-1 gene requires de novo synthesis of early gene products, including transcription factors. Finally, we demonstrated PAI-1 in lung mast cells from a patient with asthmatic attack by double-immunofluorescence study. This is the first report demonstrating that activated human mast cells release a striking amount of functionally active PAI-1. These results suggest that PAI-1 could play an important role in airway remodeling of asthma, and inhibition of PAI-1 activity could represent a novel therapeutic approach in the management of airway remodeling.

Asthma↗
PubMed2000

Evaluation of cardiac adrenergic neuronal damage in rats with doxorubicin-induced cardiomyopathy using iodine-131 MIBG autoradiography and PGP 9.5 immunohistochemistry.

Doxorubicin is one of the most useful anticancer agents, but its repeated administration can induce irreversible cardiomyopathy as a major complication. The purpose of this study was to investigate doxorubicin toxicity on cardiac sympathetic neurons using iodine-131-metaiodobenzylguanidine (MIBG) and protein gene product (PGP) 9.5 immunohistochemistry, which is a marker of cardiac innervation. Wistar rats were treated with doxorubicin (2 mg/kg, i.v.) once a week for 4 (n=5), 6 (n=6) or 8 (n=7) weeks consecutively. Left ventricular ejection fraction (LVEF), calculated by M-mode echocardiography, was used as an indicator of cardiac function. Plasma noradrenaline (NA) concentration was measured by high-performance liquid chromatography (HPLC). 131I-MIBG uptake of the left ventricular wall (24 ROIs) was measured by autoradiography. 131I-MIBG uptake pattern was compared with histopathological results, the neuronal population on PGP 9.5 immunohistochemistry and the degree of myocyte damage assessed using a visual scoring system on haematoxylin and eosin and Masson's trichrome staining. LVEF was significantly decreased in the 8-week group (P<0.05). The serum NA level also showed no statistical difference until 4 weeks and was significantly increased in the 8-week group (P<0.05). MIBG uptake was decreased in the 6- and 8-week groups (P<0.05), and was closely correlated with the reduction in the number of nerve fibres on PGP 9.5 stain. Myocyte damage was seen only in the 8-week group. Neuronal population and the 131I-MIBG uptake ratio of subepicardium to subendocardium were significantly increased (P<0.05) in the 8-week group as compared with the control group. It may be concluded that radioiodinated MIBG is a reliable marker for the detection of cardiac adrenergic neuronal damage in doxorubicin-induced cardiomyopathy; it detects such damage earlier than do other clinical parameters and in this study showed a good correlation with the reduction in the neuronal population on PGP 9.5 stain. The subendocardial layer appeared to be more vulnerable to doxorubicin than the subepicardium.

3-Iodobenzylguanidine↗
PubMed2000

Androgen receptor gene mutation identified by PCR-SSCP and sequencing in 4 patients with complete androgen insensitivity syndrome.

To study the genetic defect of the human androgen receptor (hAR) gene in the complete androgen insensitivity syndrome (CAIS), we amplified each of the eight exons by PCR in genomic DNA extracted from the paraffin blocks of the resected gonads. We analyzed using SSCP, and directly sequenced the abnormally shifted bands. Mutations were found in 4 cases of CAIS. Patient 1 carried a point mutation; a G to A transition in exon 7 resulted in a change from arginine to glutamine at codon 831. Patient 2 carried a point mutation; a C to T transition in exon 7 resulted in a change from arginine to stop at codon 831. Patient 3 carried a point mutation and deletion in exon 7. A point mutation was an A to G transition that caused a glutamine to be substituted for the asparagine present at codon 819. A deletion of a G at codon 820 resulted in a frameshift and consequently in the introduction of a premature stop at codon 821. Patient 4 carried a mutation in 5' splice donor site of intron 7; a G to T transition might have caused an abnormal splicing of the exon 7. All of the mutations were found in exon 7. These mutations of hAR gene might be related to the pathogenesis of CAIS.

Adolescent↗
PubMed2000

Expression and characterization of human tyrosinase from a bacterial expression system.

To carry out biochemical characterizations of human tyrosinase and to provide an unlimited source of the enzyme for further study, an expression plasmid, pHis-Tyrosinase, which contains the entire coding sequence except the signal sequence of a human tyrosinase was constructed and expressed in Escherichia coli. The expressed enzyme was simply purified by an immobilized metal affinity chromatography. The recombinant enzyme had the same electrophoretic mobility as the native enzyme from human melanoma cell and cross-reacted with the polyclonal antibody raised against the native enzyme. The recombinant enzyme retained its catalytic function with both hydroxylating and oxidative activities. Km values for L-tyrosine and L-3,4-dihydroxy-phenylalanine of the recombinant enzyme were 0.17 and 0.36 mM, respectively. The activity of the recombinant enzyme was optimal at pH 7.5. Glutathione notably inhibited the enzymatic activity. This work is a further enzymatic characterization of human tyrosinase.

Dihydroxyphenylalanine↗
PubMed2000

Citrus red mite (Panonychus citri) is a common sensitizing allergen among children living around citrus orchards.

BACKGROUND: A recent investigation has suggested that Panonychus citri (citrus red mite) is the most common causative allergen in citrus-cultivating farmers with asthma or allergic rhinitis. OBJECTIVE: A cross-sectional survey was performed to evaluate the prevalence of asthma and sensitization to P. citri among children living around citrus orchards. METHODS: A total of 1,055 children living around citrus orchards were enrolled. There were 544 boys and 511 girls with a mean age of 12.3 (range 7 to 16) years. They were evaluated by the ISAAC questionnaire, and a skin prick test with 13 common aeroallergens including P. citri and Japanese cedar pollen. Children who recorded ever having experienced wheezing on the questionnaire were evaluated by methacholine bronchial provocation test and determined to have asthma if they showed bronchial hyperresponsiveness to methacholine simultaneously. RESULTS: The positive skin test response to one or more inhalant allergens except P. citri was 35.5%, but when including P. citri, the positive response increased to 37.7%. The most common sensitizing allergens in the order of decreasing frequency were Dermatophagoides pteronyssinus (26.6%), D. farinae (22.7%), P. citri (14.2%), cockroach (11.3%), and Japanese cedar pollen (9.7%). Among the children without sensitization to house dust mites, the sensitization rate to P. citri was significantly higher in those 13 and over than in those under 12 (5.8% versus 2.5%, P < .05). The prevalence of asthma was not different between the children with sensitization to P. citri and those without it (5.4% versus 4.0%, P > .05), although the prevalence was higher in those with sensitization to D. pteronyssinus or D. farinae than in those without sensitization to these allergens (7.9% versus 2.9%, P < .05; 9.7% versus 2.6%, P < .05). CONCLUSION: Citrus red mite is a common sensitizing allergen among children living around citrus orchards. The features of sensitization and development of asthma are different between citrus red mite and house dust mites.

Administration, Inhalation↗
PubMed2000

Two-spotted spider mite (Tetranychus urticae): an important allergen in asthmatic non-farmers symtomatic in summer and fall months.

BACKGROUND: The Tetranychus urticae (two-spotted spider mite, TSM) is a spider mite commonly found on fruit trees, herbaceous plants, and greenhouse flowers. OBJECTIVE: To evaluate the clinical significance of TSM-derived allergens in non-farmers with asthma living around pear orchards, and to assess the allergenic relationship with house dust mite. METHODS: Skin prick tests with TSM were performed in 50 asthmatic non-farmers living around pear orchards. The serum TSM-specific IgE was measured in the 16 asthmatics with a positive skin response to TSM. To diagnose TSM-induced asthma, specific bronchial challenges with TSM were performed in the 16 asthmatics. ELISA inhibition tests were performed to assess the allergenic cross-reactivity with house dust mites. RESULTS: Ten of the 16 asthmatics with positive skin responses to TSM showed a significant bronchoconstriction following inhalation of TSM. Eight of the ten TSM-induced asthmatics had high serum TSM-specific IgE and one showed a positive skin response only to TSM. Their asthmatic symptoms were aggravated seasonally, especially in summer and early fall. On ELISA inhibition tests, partial inhibitions with D. pteronyssinus antigens were noted in sera from five asthmatics with positive skin responses to both TSM and D. pteronyssinus, although no inhibition was noted in serum from an asthmatic with a positive skin response only to TSM. CONCLUSION: Tetranychus urticae may be an important allergen in asthmatic non-farmers living around pear orchards and TSM extracts contain species-specific allergens as well as commonly shared allergens with house dust mite.

Adolescent↗
PubMed2000

Sensitivity to citrus red mite and the development of asthma.

BACKGROUND AND OBJECTIVE: The citrus red mite (Panonychus citri, CRM) is an important allergen in the development of asthma and/or rhinitis in citrus farmers and a common sensitizing allergen among exposed children. The aim of this study was to evaluate CRM-induced skin responses and serum-specific IgE, IgG4, and IgG1 responses, and their role in the development of asthmatic symptoms among exposed adolescents. METHODS: A total of 100 adolescents between the ages of 15 and 16 years (59 males and 41 females) were randomly recruited. All of the subjects responded to the ISAAC questionnaire themselves. Skin prick tests to CRM were carried out and serum-specific IgE, IgG4, and IgG1 levels were measured using ELISA. RESULTS: Fourteen subjects (14%) had experienced wheezing during last 12 months. The wheal size formed by CRM was larger than 3 mm in 23 subjects (23%). Serum-specific IgE levels were elevated in 21 subjects (21%), IgG4 levels were elevated in 32 subjects (32%), and IgG1 levels were elevated in five subjects (5%). The prevalence of wheezing during last 12 months was significantly higher in subjects with positive skin responses and serum-specific IgE responses induced by CRM than in those with negative skin responses and low serum IgE responses (30.4% versus 9.0%, P < .05; 33.3% versus 8.7%, P < .05). The prevalence of wheezing, however, did not differ according to serum-specific IgG4 levels (9.4% versus 16.2%, P > .05). Skin responses to CRM showed a significant correlation with serum-specific IgE levels, but not with IgG1 and IgG4 levels. Serum CRM-specific IgE levels correlated with specific IgG1 and IgG4 levels, but no significant correlation was found between serum IgG1 and IgG4 levels. CONCLUSION: The specific IgE responses induced by CRM were prevalent among adolescents living near citrus farms, and may be important in the development of asthma. The specific IgG4 and IgG responses induced by CRM play a minimal role in the development of asthma symptoms.

Adolescent↗
PubMed2000

Purification and characterization of a highly stable tyrosinase from Thermomicrobium roseum.

Tyrosinase, with an isoelectric point at pH 4.9, was purified to electrophoretic homogeneity from an extremely thermophilic bacterium, Thermomicrobium roseum. Gel filtration, N-terminal amino acid sequencing and SDS/PAGE analysis indicate that T. roseum tyrosinase is composed of two identical subunits, each with a molecular mass of 43000 Da. The enzyme exhibited high substrate specificity towards catechol, chlorogenic acid, L-3-(3,4-dihydroxyphenyl)-L-alanine (L-DOPA) and pyrogallol. The K(m) value of the enzyme for L-DOPA was 0.18 mM. beta-Mercaptoethanol and sodium diethyldithiocarbamate notably inhibited the enzymic activity. The activity of the enzyme was optimal at pH 9.5 and 70 degrees C, and was increased by addition of 1 mM Mg(2+), K(+) or Cu(2+). The enzyme was highly stable against high temperature and guanidine hydrochloride. The N-terminal amino acid sequence of the enzyme was determined to be Asp-Ile-Asn-Gly-Gly-Gly-Ala-Thr-Leu-Pro-Gln-Lys-Leu-Tyr. These facts indicate that T. roseum tyrosinase appears to be distinct from the tyrosinases so far purified from other sources.

Amino Acid Sequence↗
PubMed2000

Bronchial responsiveness to methacholine is increased in citrus red mite (Panonychus citri)-sensitive children without asthmatic symptoms.

BACKGROUND: A recent investigation has suggested that citrus red mite (Panonychus citri, CRM) is a common sensitizing allergen among children living around citrus farms. OBJECTIVE: A cross-sectional survey was performed to evaluate the bronchial responsiveness to methacholine in CRM-sensitive children without asthmatic symptoms. SUBJECTS AND METHODS: A total of 375 children living around citrus farms were enrolled in this study. There were 201 boys and 174 girls with a mean age of 12.5 (range 7-16) years. Each subject was evaluated by a questionnaire, a skin prick test with 13 common inhalant allergens including CRM, and a methacholine bronchial provocation test (MBPT). RESULTS: Positive rate of MBPT (PC20-methacholine < 25 mg/mL) was higher in atopic rhinitic and atopic control children than in nonatopic rhinitic and nonatopic control subjects (41.3% and 33.3% vs 17.2% and 15.4%, respectively, both P < 0.05). Slope of dose-response curve (DRS, %/mg/mL) was higher in atopic rhinitic children than in nonatopic rhinitic, atopic control and nonatopic control subjects (14.3 +/- 0.87 vs 9.4 +/- 0.72, 10.0 +/- 1.37 and 9.2 +/- 1.51, P < 0.05, respectively). Both the positive rate of MBPT and the DRS were increased in children with positive skin response to CRM than in those without sensitization (48.2% vs 22.9%, P = 0.0001; 15.6 +/- 1.26 vs 10.2 +/- 0.65, P = 0.0001). CONCLUSION: Bronchial responsiveness is increased in citrus red mite-sensitive children even if they have no asthmatic symptoms.

Adolescent↗
PubMed2000

Association of HLA-DRB1(*)07 and DRB1(*)04 to citrus red mite (Panonychus citri) and house dust mite sensitive asthma.

BACKGROUND: Specific IgE responses to allergens provide useful models for evaluating the genetic factors that control human immune responses. A recent survey demonstrated that the citrus red mite (Panonychus citri, CRM) is the most important allergen in the development of asthma in citrus farmers. OBJECTIVE: The aim of this study was to evaluate whether susceptibility or resistance to CRM-induced asthma was associated with HLA-DRB1 gene. METHODS: DNAs were extracted from two groups of unrelated Korean adults living around citrus farms: (1) Ninety-one adults with CRM-sensitive asthma; and (2) 98 exposed, healthy nonatopic controls. Genotypes of HLA-DRB1 alleles were carried out using PCR-based methods. RESULTS: Allelic frequency of HLA-DRB1(*)07 was higher in the CRM-sensitive asthmatics compared to the controls (17.6% vs 4.1%, Pc = 0.01). Conversely, the frequency of DRB1*04 was lower in the CRM-sensitive asthmatics compared to the controls (19.8% vs 40.8%, Pc = 0.01). No significant difference was found in the distributions of the other HLA-DRB1 gene-encoded antigens between the two groups. CONCLUSION: HLA-DRB1 genes may be involved in the development of CRM-induced asthma. In addition, HLA-DR7 may increase, and DR4 decrease, the risk of developing the asthma in CRM-exposed adults.

Adult↗