Biomedical subjects

C S Hong

Publications and source records attributed to C S Hong.

At least 19 recordsLinked to original sources

PubMed1997

Isolation and characterization of Drosophila presenilin homolog.

Presenilin-1 (PS1) and presenilin-2 (PS2) are associated with a majority of early onset familial Alzheimer's disease (FAD). Sequence analysis of PS1/2 has revealed integral transmembrane proteins which are highly homologous to the protein coded by sel-12, a Caenorhabditis elegans gene involved in the lin-12/Notch signaling pathway. The normal function of PS1/2, as well as the pathogenesis caused by mutations of these genes in FAD, are unknown however. We have identified a Drosophila presenilin homolog (DPS) and mapped the chromosomal location of this gene. DPS shows 53% amino acid identity to PS1/2 and 45% to the sel-12 product. Strong amino acid conservations appear at the position associated with FAD. In embryonic stages, DPS is expressed primarily in the CNS.

Alzheimer Disease↗

PubMed1997

Seasonal variation of skin reactivity and specific IgE antibody to house dust mite.

BACKGROUND: House dust mite is an important cause of bronchial asthma worldwide. While the allergen is present all year-round, a seasonal variation of house dust mite allergen levels has been found. There have been few reports, however, on seasonal variation of specific immune response to house dust mite. OBJECTIVE: We studied the changes in skin reactivity and specific IgE antibody to house dust mite associated with seasonal variation of house dust mite allergen levels in houses of mite-sensitive asthmatic patients. METHODS: In 14 mite-sensitive asthmatic patients, house dust mite allergen (Der f 1) contents in bedding were measured monthly. Skin reactivity on prick test and specific IgE antibody to house dust mite, Dermatophagoides farinae (D. farinae), were determined every 3 months from july to December. RESULTS: The concentration of Der f 1 in dust from bedding reached maximum levels in August and September, and significantly decreased in November and December compared with August and September (P < .05). Skin reactivity (a ratio of mean wheal diameter of allergen to histamine) to D. farinae decreased significantly in December compared with September (P < .05). Serum levels of total IgE and specific IgE antibody to D. farinae decreased significantly in December compared with September (P < .05). CONCLUSION: These findings suggest that seasonal changes in natural exposure to house dust mite allergen might lead to concurrent changes in skin reactivity and specific IgE antibody to house dust mite in mite-sensitive asthmatic patients.

Adolescent↗

PubMed1997

Fauna and geographical distribution of house dust mites in Korea.

During the period of 1933-1994, house dusts were collected from 65 homes at 10 different localities by operating electric vacuum cleaners. House dust mites were isolated from 10 g dust by applying the modified wet sieving method. Total 7,257 mites were collected and 23 species were identified. Among them. Dermatophagoides farinae (DF) was predominant (65.3% of the total), followed by D. pteronyssinus (DP) (20.6%) and Tyrophagus putrescentiae (TP) (6.5%). Rhizoglyphus robini. Sancassania phyllophagianus, Cheyletus traussarti and Scheloribates latipes were the first findings from Korea. DF was predominant in Seoul (66.8%). Kwangju (63.6%), inland of Pusan (79.6%), Inchon (96.5%). Taejon (83.9%), Chonju (87.15) and Chongju (95.2%), whereas DP was predominant in Yongkwang-ub (72.5%) and Yongdo (island) of Pusan (64.9%), and TP in Chunchon (38.2%). The localities where DP and TP were predominant showed higher relative humidity in air (> 73% RH). Among 62 study homes, DF, DP and TP were found in 24.6% of the homes, co-habitat of two species in 48.1% and one species in 27.3%. DF was predominant in 63.5% of the homes studied. DP in 29.6% and TP in 6.9%. In 10 g of the house dust, less than 99 mites were found in 49 homes (70.0%), 100-499 mites in 11 homes (15.7%). 500-999 mites in 3 homes (4.3%) and more than 1,000 mites in 2 homes (2.9%). No mite was found in 5 homes (7.1%). In order to evaluate environmental factors affecting the population density of house dust mites, house type, age of house construction, size of the house, number of the family and frequency of the cleaning were compared with the number of mites, and none of the above factors were statistically correlated with the mite density.

Animals↗

PubMed1996

Photocatalytic degradation of PCBs in TiO2 aqueous suspensions.

A generator-column technique was used to prepare aqueous solutions of PCBs. The degradation of 2-chlorobiphenyl, Aroclor 1248, Aroclor mixture (1221, 1016, 1254, and 1260) and St. Lawrence River water by simulated sunlight or sunlight has been investigated in the presence of aqueous suspensions of TiO2. The effect of TiO2 concentration and pH on the degradation rate of PCBs have been studied. The reaction rate followed apparent first-order kinetics and increased with increasing TiO2 concentration. The half-life of the degradation process for 2-chlorobiphenyl is 20 minutes at pH 10 and 9 minutes at pH 3 in the presence of 25 mg/L of TiO2. Less chlorinated PCBs decomposed faster than higher chlorinated ones. The rate constants and half-lives of individual PCBs in the commercial PCB mixture and St. Lawrence River water were also measured.

Catalysis↗

PubMed1996

Occupational asthma due to deer dander.

BACKGROUND: The literature on allergy to deer is limited. The allergenic component remains to be identified. METHODS: We report a case of occupational asthma and rhinitis caused by deer dander. A 44-year-old male farmer had raised three red deer on his farm for 2 years, prior to occurrence of asthmatic symptoms. Dander extract was prepared from the patient's deer. RESULTS: Skin-prick test elicited positive reactions to dander extracts from goat, sheep, camel, and cow as well as to deer dander extract. Bronchoprovocation test with deer dander extract elicited an early asthmatic response. Serum-specific IgE antibody to the deer dander extract was detected by enzyme-linked immunosorbent assay (ELISA). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analysis showed five IgE binding components (110, 72, 59, 45, and 21 kilodalton) within the deer dander extract. CONCLUSIONS: These results suggest that deer dander can induce occupational asthma through an IgE-mediated mechanism in a farmer raising deer.

Adult↗

PubMed1996

Molecular characterization of neurally expressing genes in the para sodium channel gene cluster of drosophila.

To elucidate the mechanisms regulating expression of para, which encodes the major class of sodium channels in the Drosophila nervous system, we have tried to locate upstream cis-acting regulatory elements by mapping the transcriptional start site and analyzing the region immediately upstream of para in region 14D of the polytene chromosomes. From these studies, we have discovered that the region contains a cluster of neurally expressing genes. Here we report the molecular characterization of the genomic organization of the 14D region and the genes within this region, which are: calnexin (Cnx), actin related protein 14D (Arp 14D), calcineurin A 14D (CnnA14D), and chromosome associated protein (Cap). The tight clustering of these genes, their neuronal expression patterns, and their potential functions related to expression, modulation, or regulation of sodium channels raise the possibility that these genes represent a functionally related group sharing some coordinate regulatory mechanism.

Actins↗

PubMed1995

Generator column determination of aqueous solubilities for non-ortho and mono-ortho substituted polychlorinated biphenyls.

Aqueous solubilities of four non-ortho and eight mono-ortho substituted PCBs were determined using a generator-column technique followed by subsequent off-line GC/ECD analysis of the aqueous solutions. The method is based on pumping water through a column containing glass beads coated with the congener being studied and has been used to measure solubilities at room temperature. The method circumvents many of the experimental difficulties encountered with the traditional shake-flask system. Aqueous solubility of 3,3',4,4'-tetrachlorobiphenyl determined by this procedure is compared with data obtained from the shake-flask method and the computational method. The precision of replicate measurements is better than +/- 6.5%. Aqueous solubilities determined for 12 congeners ranged from 6.07 x 10(-11) to 4.47 x 10(-9) mol/L and generally decreased with molecular weight and increased with degree of ortho-chlorine substitution within a molecular-weight class.

Chromatography, Gas↗

PubMed1995

Structural modeling of differential diagnosis, treatment, and results for allergic rhinitis.

This paper analyzed the relationship among the differential diagnosis, treatment, and results for allergic rhinitis using the covariance structural model. The data were collected from 274 patients with suspected allergic rhinitis who visited the Otorlaryngology Department of the Paik Hospital during 1991-1993. After each patient's characteristics was categorized and combined into several common factors, covariance structure analysis was performed to analyze the structural relationships among the differential diagnosis, treatment, and results of treatment using the significant factors obtained from discriminant analysis. The significant characteristics influenced the diagnosis were the results of skin test from mite/animal, and from mugworts, the results from laboratory tests, rhinorrhea and sneezing, and nasal polyps. The significant characteristics that influenced the method of treatment were: nasal polyps, headache/general symptom, family history/medication, and septal deviation. Headache/general symptom was the only significantly influencing factor for the treatment results.

Diagnosis, Differential↗

PubMed1995

Effects of autologous sera on immediate and late skin reaction to the house dust mite in atopic individuals.

To evaluate the in vivo effect of autologous serum including antibodies to house dust mite in atopic individuals, we observed the immediate (15 mins) and late (6 hours) skin reactions (ISR, LSR) on intradermal (ID) test of serially diluted Dermatophagoides farinae antigens (DFa, Allergopharma, Germany) mixed with autologous sera (DFa-S) and diluent alone (DFa-D). We tested 34 DFa-skin reactive atopic individuals including 12 asthmatics (BA), 8 asthmatics on immunotherapy with DFa (IT), and 14 healthy atopic controls (AC). We observed complete inhibition of ISR in the lowest allergen dose of DFa-S in 7 (58.3%) of 12 BA, 3 (37.5%) of 8 IT, and 2 (14.3%) of 14 AC. In BA, the inhibition of ISR was more frequent than AC (p < 0.05). We observed larger late reactions in half of LSR positive cases on ID test by DFa-S than by DFa-D (> or = 1.5 X size; accentuation of LSR). Accentuation of LSR were shown more frequently by DFa mixed with larger amount of serum (25% in 1:1 mix; 80% in 1:3 mix, p < 0.05). But there were no differences of DFa-specific IgE and IgG subclass antibodies regardless of the inhibition of ISR or the accentuation of LSR. In conclusion, some autologous sera from DFa-sensitive individuals showed the inhibition of ISR and the accentuation of LSR on DFa-ID test.

Animals↗

PubMed1994

Mono-ortho- and non-ortho-substituted polychlorinated biphenyls in human milk from Mohawk and control women: effects of maternal factors and previous lactation.

Fifty-four individual human milk samples from 50 mothers (20 Mohawks and 30 controls) were analyzed for four non-ortho- and eight mono-ortho-substituted polychlorinated biphenyls (PCBs). Mean total coplanar PCBs concentrations were 49 ng/g and 55 ng/g lipid for Mohawk and control women, respectively. A statistical evaluation of all analytical data reveals no significant difference of total coplanar PCB level between Mohawk and control women. The level of these contaminants is influenced by the age of the mother, number of breastfed children, and length of nursing period. Older women, primiparae, and cigarette smokers had higher levels of coplanar PCBs. In general, women had higher levels of coplanar PCBs in the first lactation and in the earlier samples of a given lactation, while levels declined both with duration of breast-feeding and with number of children nursed. The contribution of individual non-ortho- and mono-ortho-substituted PCB congeners to the total calculated toxic equivalent values (sigma TEQ) was assessed for the breast milk samples. The levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in human milk of pooled specimens from Los Angeles, California and Binghamton, New York, widely separate cities in the United States (Schecter et al. 1989), were presented for reference purpose. The main contributions to the sigma TEQ were PCB congeners #118 (25.8 pg/g lipid), #126 (25 pg/g lipid), #105 (10.8 pg/g lipid), and #156 (7.4 pg/g lipid). Collectively, these compounds accounted for 70% of the sigma TEQ values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1994

Measurement of IgE and IgG subclass antibodies to whole body antigen and two major allergens (Der fI & Der fII) of Dermatophagoides farinae in normal subjects and asthmatics.

House dust mites have been known as the most important allergen in respiratory allergic diseases. Among several mite allergens, group I and group II antigens were recognized as major allergens. We measured specific IgE and IgG subclass antibodies against whole body antigen (WBA) and two major allergens of Dermatophagoides farinae (Der fI and Der fII) in sera from 66 adults with asthma (asthma group) and 34 normal subjects (healthy group) by ELISA. The mean O.D. values of WBA-specific IgE and IgG subclass antibodies in 100 studied sera were significantly higher than those of the two major allergens (p < 0.001) and the level of Der fII- IgG1, IgG4 and IgE were higher than those of Der fI but IgG2 of Der fI was higher than that of Der fII (p < 0.001). The level of IgG4 of WBA were significantly higher in the atopic group than in the nonatopic group (1.280 +/- 0.634 v.s. 0.8290 +/- 0.388, p < 0.001), but the WBA- IgG1, IgG2, IgG3 were not different between the two groups. Among IgG subclass antibodies of Der fI, IgG2 was significantly higher in the nonatopic group than in the atopic group (1.7770 +/- 0.255 v.s. 1.636 +/- 0.390, p < 0.05) but there were no differences in IgG1, IgG3, and IgG4. Among IgG subclass antibodies of Der fII, IgG2 (1.534 +/- 0.380 v.s. 1.3010 +/- .431, p < 0.05) and IgG4 (1.09650 +/- .567 v.s. 0.708 +/- 0.146, p < 0.001) were significantly higher in the atopic group than in the nonatopic group. IgE antibodies to WBA, Der fI and Der fII were significantly higher in the atopic group (p < 0.001). There were significant correlationships between the levels of IgE and IgG4 of WBA (r = 0.60), Der fI (r = 0.33) and Der fII (r = 0.72). Even though there were no differences in the levels of allergen specific IgE and IgG subclass antibodies between nonatopic healthy and nonatopic asthmatic groups, the number of sera with prominent level of IgG2 of WBA were more common in the nonatopic asthmatic group (69% in nonatopic asthma group v.s. 28% in nonatopic healthy group, X2-test, p < 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Allergens↗

PubMed1994

Spatial and temporal expression patterns of two sodium channel genes in Drosophila.

Genetic and molecular studies have identified two different sodium channel genes in Drosophila, para and DSC1. The functional contributions of the para-encoded channel have been inferred from analysis of mutant phenotypes. However, no mutations of DSC1 have been identified, so the in vivo functions of the channel it encodes are not yet known. To learn more about the possible functions of DSC1 in the Drosophila nervous system compared with those of para, we have characterized the expression patterns of these two sodium channel genes at embryonic, larval, pupal, and adult stages by tissue in situ hybridization, para encodes the predominant type of sodium channel and is ubiquitously transcribed throughout the CNS and PNS at all developmental stages. The expression pattern of DSC1 is very different from para during embryonic and larval stages during which there are very few DSC1-expressing cells in either the CNS or PNS. Double-labeling studies suggest that some of these cells are non-neuronal. However, in pupal and adult stages, para and DSC1 have completely overlapping patterns of expression in the CNS and retina. In the pupal and adult, PNS expression of these genes is still distinct because only para transcripts are detected in wing sensory neurons. The strong and widespread expression of DSC1 in the CNS of pupae and adults suggests that the DSC1 channels are likely to provide an important function in neurons during these stages. Since most, if not all, neurons in the pupal and adult CNS express both para and DSC1, these two sodium channel genes probably subserve distinct functions within these cells. Our results provide the background for elucidating the respective in vivo contributions of para and DSC1 to neuronal excitability and for dissecting the regulatory mechanisms that underlie their different patterns of expression.

Animals↗

PubMed1993

Randomized comparative study of fleroxacin and chloramphenicol in typhoid fever.

This study compared fleroxacin, 400 mg daily for 7 or 14 days, with chloramphenicol, 50 mg/kg per day for 14 days, for the treatment of patients with typhoid fever in a multicenter study. A total of 184 patients were randomly assigned to the three treatment groups. Efficacy was determined by culture of blood and stool, overall clinical response, and time to defervescence. Safety was assessed by occurrence of adverse events and laboratory abnormalities. A total of 97 patients were evaluable for efficacy, 28 in the fleroxacin 7-day group, 35 in the fleroxacin 14-day group, and 34 in the chloramphenicol group. All showed rapid defervescence with high cure rates. Bacteriologic cure rates were 96% in the fleroxacin 7-day group, 97% in the fleroxacin 14-day group, and 85% in the chloramphenicol group. Clinical cure rates were 83-100% with fleroxacin and 82% with chloramphenicol. The time to defervescence was shorter for patients treated with fleroxacin than for those treated with chloramphenicol. All three treatment regimens were well tolerated. Fleroxacin, 400 mg daily for 7 days, appears to be satisfactory for the treatment of typhoid fever and compares favorably with the standard 14-day therapy with chloramphenicol.

Adolescent↗

PubMed1993

Toxic potential of non-ortho and mono-ortho coplanar polychlorinated biphenyls in Aroclors, seals, and humans.

Mono-ortho and non-ortho coplanar polychlorinated biphenyls (PCBs) were analyzed in Aroclors, seals, and humans by graphitized carbon, a recently developed HPLC method (Hong et al. 1992b) and high-resolution gas chromatography with electron capture detection (HRGC/ECD). The concentration data were multiplied by potency factors derived from aryl hydrocarbon hydroxylase (AHH) induction to give 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents. The ability to separate coplanar PCBs from the majority of PCBs has allowed the use of TCDD toxicity equivalence to compare the relative dioxin-like potency of PCB residues in the complex mixtures. The most active mixtures, Aroclors 1254, 1248, and 1242, contained 42-54% by weight of chlorine. The results demonstrate that the apparent dioxin-like potency of PCB residues in Aroclors, seals, and humans is dominated by three congeners, 3,3',4,4'-tetra-, 2,3,3'-4,4'-, and 3,3',4,4',5-pentachlorobiphenyl (IUPAC nos. 77, 105, 126).

Adipose Tissue↗

PubMed1993

Immunoelectron-microscopic localization of IgE binding site of mugwort pollen.

To elucidate the IgE binding site of mugwort (Artemisia vulgaris r.) pollen, pollen grains were frozen and fixed using a cryocut. They were incubated with antibodies according to the following sequence: Sera pool of individuals who showed mugwort-RAST class 3 or 4, biotin-labeled goat anti-human IgE antibody, streptavidin-peroxidase and diaminobenzidine. Then, they were observed under electron microscopy. The control section was incubated with the sera pool from individuals who showed a negative result on a skin prick test to mugwort pollen. Antigenic activity (electrondense line) was noted on the surface of the exine. There was no activity in cytoplasm or the intine layer. The control section was completely free of activity. It was suggested that the IgE binding site of mugwort pollen was present on the surface of the exine.

Binding Sites↗

PubMed1993

The relationship of stress with serum IgE level in patients with bronchial asthma.

The relationship of stress perception and frequency of stressors with serum total Ig E level was investigated in 54 outpatients with bronchial asthma. The GARS (global assessment of recent stress) scale and SRRS (social readjustment rating scale) were used to measure the degree of stress perception and frequency of stressors during a one-year period Total serum Ig E was measured by the PRIST method. 56% of the patients were found to have psychosomatic disorders, but there was no significant difference in stress perception and frequency of stressors between psychosomatic and non-psychosomatic groups. A considerable number of patients (63%) rated their symptoms as severe, but no significant correlation was found between severity of symptoms and stress perception. Severity of stress perception and frequency of stressors did not correlate with serum total Ig E level. Multiple regression analysis revealed that female patients were significantly higher in stress perception than male ones, and that chronicity of illness was more likely to increase stress perception. Extrinsic asthmatics had significantly more negative stressors than intrinsic ones. In conclusion, serum Ig E is considered a stable indicator of allergy not influenced by stress. It was also indicated that patients with bronchial asthma were more likely to perceive physical symptoms than psychological stress.

Adolescent↗

PubMed1992

Coplanar PCBs in fish and mussels from marine and estuarine waters of New York State.

Thirty samples of striped bass from marine and estuarine waters of New York State, six samples of mussels from Long Island Sound, and one composite sample of freshwater mussels from Troy were analyzed by a recently developed method which combines sulfuric acid cleanup, carbon chromatography, and high-resolution gas chromatography for the determination of non-ortho- and mono-ortho-substituted polychlorinated biphenyls (PCBs), which are biologically active congeners of PCBs and approximate isostereomers of 2,3,7,8-tetrachlorodibenzo-P-dioxin of (2,3,7,8-TCDD). Non-ortho coplanar PCBs ranged from 0.2 to 37.1 ppb in fish. The highest concentrations of 37.1 ng/g of 3,3',4,4'-tetrachlorobiphenyl (77) and 7.5 ng/g of 3,3',4,4',5-pentachlorobiphenyl (126) were detected in a fish caught near Troy/Albany, New York. Mono-ortho-substituted PCBs ranged from 0.4 to 790 ppb in fish, with the major components identified as 2,3',4,4',5-penta-(118) and 2,3,3',4,4'-pentachlorobiphenyls (105). When concentrations were converted to 2,3,7,8-TCDD picogram equivalents, 99% of the equivalents were derived from three congeners (77, 105, and 126), 3,3',4,4',5-pentachlorobiphenyl (126) accounting for approximately 80% of the activity. At Troy pg/g TCDD equivalents derived from PCB were approximately 3000, whereas the actual 2,3,7,8-TCDD concentration was only 20 pg/g; hence, accurate coplanar PCB measurement is important.

Animals↗

PubMed1992

Heterogeneity of IgE antibody response to reactive dye in sera from four different sensitized workers.

We studied RAST and RAST inhibition tests to black GR, the most frequent sensitizer among several reactive dyes in our previous study, in order to evaluate the specificity of IgE antibodies to hapten or new antigenic determinants and the crossreactivity between two reactive dyes, black GR and orange 3R, in sera from four different sensitized workers. RAST inhibition studies with black GR-human serum albumin (HSA) conjugate discs demonstrated that black GR-HSA conjugates were the most effective inhibitors. Orange 3R-HSA conjugates, unconjugated forms of black GR and orange 3R were weak inhibitors in two patients and non-inhibitory in one patient, whereas they caused strong dose-dependent inhibitions in one patient. These results suggested that the IgE response to black GR-HSA conjugates might be heterogenous and the crossreactivity between two reactive dyes differed from one patient to another.

Antibody Specificity↗