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Biomedical subjects

H J Su

Publications and source records attributed to H J Su.

17 recordsLinked to original sources
PubMed2001

Exposure assessment of indoor allergens, endotoxin, and airborne fungi for homes in southern Taiwan.

This study was undertaken to examine the seasonal variations of domestic Der p 1, Der p 2, and endotoxin on mattress and airborne fungal concentrations in homes of asthmatic and nonasthmatic children in southern Taiwan, where temperature and relative humidity are usually high throughout the year. A group of asthmatic children (10-12 years old) were selected randomly based on a citywide questionnaire survey. The nonasthmatic children were chosen to be in the comparison group by matching in age, gender, and proximity of residence. Environmental sampling of domestic microbes was conducted once a month for a year. Twelve calendar months were grouped into spring, summer, fall, and winter according to weather data (mainly average temperature and humidity) from the Central Weather Bureau. Dust samples from a child's mattress and airborne samples from a child's bedroom were collected and analyzed for allergens of Der p 1 and Der p 2, endotoxin, and fungi respectively. Results show that about 65% of children's mattresses in our region have Der p 1 levels greater than 2 microg/g. It is also apparent that most airborne fungal concentrations found in homes of either asthmatic or nonasthmatic children are higher than the recommended levels of concern. The predominant genera are Cladosporium, Aspergillus, Penicillium, Alternaria, and yeast. In addition, seasonal effects seem to be a critical factor for the concentrations and distributions of domestic endotoxin in these study homes. The implication of long-term exposure to these high levels of environmental microbes and how their effects vary with seasons remain to be further characterized.

Air Pollution, Indoor↗
PubMed2001

Exposure of workers to airborne microorganisms in open-air swine houses.

This study quantified the levels of airborne microorganisms in six swine farms with more than 10,000 pigs in subtropical Taiwan. We evaluated breeding, growing, and finishing stalls, which were primarily open-air buildings, as well as partially enclosed farrowing and nursery piggeries. Airborne culturable bacteria, gram-negative bacteria, and fungi were placed on appropriate media by using an all-glass impinger or single-stage Andersen microbial sampler. Results showed that mean concentrations of culturable bacteria and gram-negative bacteria were 3.3 x 10(5) and 143.7 CFU/m(3), respectively. The concentration of airborne culturable fungi was about 10(3) CFU/m(3), with Cladosporium the predominant genus. The highest airborne levels of culturable bacteria and gram-negative bacteria were identified in the finishing units. The air of the nursery stalls was the least contaminated with culturable and gram-negative bacteria. Irregular and infrequent cleaning, high pig density, no separation of wastes from pen floors, and accumulation of water as a result of the processes for cleaning and reducing pig temperature possibly compromise the benefits of the open characteristic of the finishing units with respect to airborne bacterial concentration.

Air Microbiology↗
PubMed2001

Exposure assessment to airborne endotoxin, dust, ammonia, hydrogen sulfide and carbon dioxide in open style swine houses.

Information is limited for the exposure levels of airborne hazardous substances in swine feed buildings that are not completely enclosed. Open-style breeding, growing and finishing swine houses in six farms in subtropical Taiwan were studied for the airborne concentrations of endotoxin, dust, ammonia, hydrogen sulfide and carbon dioxide. The air in the farrowing and nursery stalls as partially enclosed was also simultaneously evaluated. Three selected gases and airborne dusts were quantified respectively by using Drager diffusion tubes and a filter-weighing method. Endotoxin was analyzed by the Limulus amoebocyte lysate assay. Average concentration of airborne total endotoxin among piggeries was between 36.8 and 298 EU/m(3), while that for respirable endotoxin was 14.1-129 EU/m(3). Mean concentration of total dust was between 0.15 and 0.34 mg/m(3), with average level of respirable dust of 0.14 mg/m(3). The respective concentrations of NH3, CO2 and H2S were less than 5 ppm, 600-895 ppm and less than 0.2 ppm. Airborne concentrations of total dust and endotoxin in the nursery house were higher than in the other types of swine houses. The finishing house presented the highest exposure risk to NH3, CO2 and H2S. Employees working in the finishing stalls were also exposed to the highest airborne levels of respirable endotoxin and dust. On the other hand, the air of the breeding units was the least contaminated in terms of airborne endotoxin, dust, NH3, CO2 and H2S. The airborne concentrations of substances measured in the present study were all lower than most of published studies conducted in mainly enclosed swine buildings. Distinct characteristics, including maintaining swine houses in an open status and frequent spraying water inside the stalls, significantly reduce accumulation of gases and airborne particulates.

Air Pollution, Indoor↗
PubMed2000

Different cell death mechanisms and gene expression in human cells induced by pentachlorophenol and its major metabolite, tetrachlorohydroquinone.

Pentachlorophenol (PCP) and its salt are used extensively as biocide and wood preservative. Due to improper disposal, PCP has become an environmental pollutant and is now considered to be ubiquitos. Metabolic studies carried out in rodents or human liver homogenate have indicated that PCP undergoes oxidative dechlorination to form tetrachlorohydroquinone (TCHQ). The cytotoxicity, cell death mechanisms and gene expression of PCP and TCHQ are investigated in human liver and bladder cells and show that TCHQ induces apoptosis and DNA genomic fragmentation in bladder cells but not liver cells. No apoptotic features could be induced by treatment of PCP in both cell lines. The concentrations of PCP required to cause 50% cell death in T-24 and Chang liver cells were 5-10-fold greater than the concentrations of TCHQ. Several gene products are important in controlling the apoptotic and necrotic processes. Of these, hsp 70, CAS, bcl-2 and bax were studied. The expression of the hsp70 gene increased significantly (2-3-fold) in cells treated with TCHQ. However, no significant change was found in the cells treated with PCP. The expression of CAS gene decreased significantly in T-24 cells treated with both TCHQ and PCP. Whereas, no significant change was found in Chang liver cells with the same treatment. In addition, the expression of the bcl-2/bax protein decreased significantly in these two cell lines treated with TCHQ but not PCP.

Apoptosis↗
PubMed2000

A comparison of sampling media for environmental viable fungi collected in a hospital environment.

Quantitative evaluation of fungal exposure is often conducted by analysis of the composition of microbes in air samples and calculation of the concentrations afterward. The collecting medium that favors the growth for most saprophytic fungi is considered to be the ideal choice in most circumstances. Currently, the culture medium most frequently adopted in environmental sampling for airborne fungi is MEA (malt extract agar) recommended by the ACGIH for its suitability for most fungal growth. DG18 (dichloran glycerol-18), developed in 1980, is suggested for growth at lower water activity (a(w)=0.95) specifically and is not as commonly used in general studies. This investigation collected airborne viable fungi using a single stage/N6 Andersen impactor with MEA and DG18 agar plates attached simultaneously to the same set of samplers. The sampling locations were at 17 sites within a central air-conditioned hospital. After incubation and morphological identification, concentrations of airborne fungi and bacteria were expressed as CFU/m(3) (colony forming units/m(3)). There are 405 DG18 plates and 378 plates available for statistical analysis. Results show that the airborne fungal concentrations, shown by geometric mean (GM), are higher from the DG18 plates than from the MEA plates. The total fungal concentrations is 68.6 vs 12.94 CFU/m(3), and for Aspergillus spp., the concentration is 1.58 vs 0.72 CFU/m(3); for Penicillium spp., 3.37 vs 0.71; and for yeast, 5.09 vs 0.49 CFU/m(3). In addition, the number of different genera present is greater on the DG18 plates than on the MEA plates, on average, 2.85 types vs 1.72. This study suggests that in a hospital environment with 24-h, central air conditioning, DG18 plates appear to be more effective in collecting more fungal colonies in terms of both quantity and types of genera. Such a finding is presumed to be attributed to the characteristic of DG18 in slowing colony growth so that the dominating genus will not over occupy the culture plate surface before the less competitive genus can fully develop. Future studies on related biological mechanisms are essential to conclude whether the above results sustain when sampling is conducted in other environments.

Air Pollutants↗
PubMed2000

New lanostanoids of Ganoderma tsugae.

Three new compounds, (24R, S)-3alpha-acetoxy-24-hydroxy-5alpha-lanosta-8,25-di en-21-oic acid, named tsugaric acid C (1); 3alpha-acetoxy-5alpha-lanosta-8, 24-diene-21-O-beta-D-xyloside, named tsugarioside B (2); and 3alpha-acetoxy-(Z)-24-methyl-5alpha-lanosta-8,23,25-tr ien-21-oic acid ester beta-D-xyloside, named tsugarioside C (3), and a mixture of two known steroids were isolated from the fruit bodies of Ganoderma tsugae. The structures of 1-3 were determined by spectral and chemical methods. The cytotoxic activity of the lanostanoid constituents of this fungus was evaluated against several different cancer cell lines.

Drug Screening Assays, Antitumor↗
PubMed2000

Simple two-color array-based approach for mutation detection.

The ability to analyze multiple polymorphic/mutation sites rapidly and accurately is pivotal in all areas of genetic analysis. We have applied single nucleotide primer extension (SNE) for detection of multiple point mutations in a micro-array format using two-color, fluorescent dye-tagged dideoxynucleoside triphosphate terminators (ddNTPs). The oligonucleotide primer ending one nucleotide short of the mutation site being probed is bound to the slide and single-base extended in place with two different Cy5/Cy3 dye-tagged terminators using solution-phase, locus-specific, single-stranded complementary templates generated by PCR from genomic DNA. The composite fluorescence produced contains peaks of distinct wave lengths corresponding to each Cy dye-tagged terminator incorporated, resulting in a fluorescent 'fingerprint' for each DNA target. DNA polymerase-catalyzed incorporation of Cy dye-tagged dideoxynucleoside triphosphates was dependent on the particular dyes, the specific ddNTP, the DNA target concentration, sequence of the template, on-slide temperature cycling and washing conditions. Results from analysis of mutations in the human hemochromatosis and connexin 26 genes show that this approach has several advantages over existing methods and is simple, rapid, robust, cost effective and accurate with potential applications in many areas of genetic analysis.

Amino Acid Substitution↗
PubMed1999

Reductions in binding and functions of D2 dopamine receptors in the rat ventral striatum during amphetamine sensitization.

Rats receiving amphetamine (5 mg/kg, i.p. once daily) for 14 continuous days develop behavioral sensitization to a subsequent amphetamine challenge (1 mg/kg) at withdrawal days 8 to 10. The present study was aimed at investigating whether there are changes in binding or functions of striatal D2 dopamine receptors in amphetamine-sensitized rats. The results indicated that the Bmax value of D2 receptors in the ventral striatum decreased 40% and 52% 7 and 10 days after amphetamine withdrawal, respectively, without changes in their binding affinities (Kd). During this withdrawal period, the D(2/3) receptor agonist-induced (a) locomotor activation (bromocriptine, 5 mg/kg, i.p. or quinpirole, 1 mg/kg, i.p.) and (b) inhibition of forskolin-enhanced adenylyl cyclase activity (bromocriptine, 50 or 150 microM) in the ventral striatum were both suppressed as compared with saline controls. The decreases in D2 receptor function were unrelated to the coupled G-proteins, since none of the G alpha i-3, G alpha o or G alpha q in the ventral striatum exhibited quantitative differences between control and amphetamine sensitized rats. Collectively, these results demonstrate that intermittent amphetamine administration for a period of 14 days leads to diminished D2 receptor expression and functions in the ventral striatum at late withdrawal periods. The decrease of D2 receptors might reflect cellular mechanisms underlying the expression of amphetamine sensitization.

Adenylyl Cyclases↗
PubMed1999

Climate, traffic-related air pollutants, and asthma prevalence in middle-school children in taiwan.

This study compared the prevalence of asthma with climate and air pollutant data to determine the relationship between asthma prevalence and these factors. We conducted a nationwide survey of respiratory illness and symptoms in middle-school students in Taiwan. Lifetime prevalences of physician-diagnosed asthma and of typical symptoms of asthma were compared to air monitoring station data for temperature, relative humidity, sulfur dioxide, nitrogen oxides, ozone, carbon monoxide, and particulate matter with aerodynamic diameter [less than/equal to] 10 microm (PM(10)). A total of 331,686 nonsmoking children attended schools located within 2 km of 55 stations. Asthma prevalence rates adjusted for age, history of atopic eczema, and parental education were associated with nonsummer (June-August) temperature, winter (January-March) humidity, and traffic-related air pollution, especially carbon monoxide and nitrogen oxides, for both girls and boys. Nonsummer temperature, winter humidity, and traffic-related air pollution, especially carbon monoxide and nitrogen oxides, were positively associated with the prevalence of asthma in middle-school students in Taiwan.

Adolescent↗
PubMed1998

System for preparing microhybridization arrays on glass slides.

We describe the construction and operation of an arrayer system to produce patterns of DNA sequences for analytical uses such as microarrays of oligonucleotide on microchips. Detailed documentation on construction is provided, as well as added electronic circuitry and the software for the instrument, including programs to machine its own working surface as well as those to operate it as an arrayer. Its cost is modest, and with a single droplet tip it can deposit 96 spots per slide on 32 slides in about 200 min (readily upgraded to higher speeds). As currently operated, it can place 400 spots in 1 cm2, and this density, too, can be increased easily. We discuss design features and performance to demonstrate utility and flexibility.

Microchemistry↗
PubMed1997

Susceptibility of endothelial cells to bovine herpesvirus type 4 (BHV-4).

The sensitivity of two different types of cells to bovine herpesvirus type 4 (BHV-4) was compared by median tissue culture infectious dose (TCID50) assays. The bovine arterial endothelial (BAE) cell culture derived from bovine carotid arteries was 100-1000 times more sensitive to two strains of BHV-4, Movar 33/63 and DN 599, than Madin Darby bovine kidney (MDBK) cell line commonly used for the propagation of these viruses. BAE cell cultures infected with BHV-4 displayed cytopathic effects (CPE) earlier and more prominently than the MDBK cells infected with the same viruses. BAE cells were also more sensitive than MDBK cells in conventional plaque assays in that the former developed well characterized and easily recognized plaques after infection with the viruses. BAE cells, which are proved to be exceptionally susceptible to BHV-4, can be used in the detection and quantitation of BHV-4.

Animals↗
PubMed1994

Genome characterization and identification of viral-associated dsDNA component of banana bunchy top virus.

The single-stranded (ss) and double-stranded (ds) viral-associated DNAs (VADs) of banana bunchy top virus (BBTV) were characterized. The ssVADs were shown to be the viral genomic DNA and the dsVADs are the likely replication forms. Both dsVADs and ssVADs contain DNA species that cross-hybridize to each other. Under the electron microscope, both circular and linear DNAs were observed from these VAD species. Libraries were constructed from VADs to further characterize them. Two overlapping VAD clones were isolated and their combined sequence indicated that their corresponding VAD, named as BBTV component 2, is circular with a size of 1095 nt. The largest ORF spans from nucleotides 82 to 390, which is sandwiched by a putative TATA box, 54 nt upstream from the first ATG codon, and a AATAAA motif, 7 nt downstream from the UAA codon. Although the sequence of this VAD is different from the previously reported BBTV component 1 (Harding et al., J. Gen. Virol. 74, 323-328, 1993) and the genome of coconut foliar decay virus (Rohde et al., Virology 176, 648-651, 1990), stretches of highly homologous sequences were found between BBTV component 2 and the other two viral genomes by computer analysis. The sequence of BBTV component 1 is highly homologous to one of the clones, pBTs26, in the VAD library. Nevertheless, our libraries still contain many clones which hybridized with ss viral genomic DNAs but not with pBTs26 and BBTV component 2, indicating that the viral genome consists of more than two components.

Base Sequence↗
PubMed1992

Examination of fungi in domestic interiors by using factor analysis: correlations and associations with home factors.

Factor analysis was utilized to investigate correlations among airborne microorganisms collected with Andersen samplers from homes in Topeka, Kans., during the winter of 1987 to 1988. The factors derived were used to relate microbial concentrations with categorical, questionnaire-derived descriptions of housing conditions. This approach successfully identified groups of common aboveground decay fungi including Cladosporium, Alternaria, Epicoccum, and Aureobasidium spp. The common soil fungi Aspergillus and Penicillium spp. were also separated as a group. These previously known ecological groupings were confirmed with air sampling data by a quantitative evaluation technique. The aboveground decay fungi sampled indoors in winter were present at relatively high concentrations in homes with gas stoves for cooking, suggesting a possible association between these fungi and increased humidity from the combustion process. Elevated concentrations of the soil fungi were significantly (P = 0.05) associated with the dirt floor, crawl-space type of basement. Elevated concentrations of water-requiring fungi, such as Fusarium spp., were shown to be associated with water collection in domestic interiors. Also, elevated mean concentrations for the group of fungi including Cladosporium, Epicoccum, Aureobasidium, and yeast spp. were found to be associated (P = 0.03) with symptoms reported on a health questionnaire. This finding was consistent with our previous study of associations between respiratory health and airborne microorganisms by univariate logistic regression analysis.

Air Microbiology↗
PubMedDate not supplied

Fungal exposure of children at homes and schools: a health perspective.

The authors investigated airborne fungal exposure of Taiwanese children at homes and schools-locations where they spent the majority of their time. Pairs of asthmatic and healthy children, matched by age, gender, classes (schools), and residence, participated in the study. Airborne fungal concentrations at homes and schools, and time-activity data of the study subjects were collected. In winter, the indoor geometric mean concentration was 9,672.1 colony-forming units per cubic meter and 4,380.9 colony-forming units per cubic meter in summer. The indoor/outdoor concentration ratio was similar in all homes for both seasons. Fungal concentrations in southern Taiwan were high during both winter and summer. Personal fungal exposure was not statistically different between asthmatic and nonasthmatic children, after adjustment of time-activity patterns. Higher symptom scores were shown for children in homes with higher fungal exposures.

Air Pollution, Indoor↗