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21.
Horng CJ Horng PH Lin SC Tsai JL Lin SR Tzeng CC 《Biological trace element research》2002,88(3):235-246
Some of the most pernicious dangers of pollution arise from the presence of traces of toxic elements in the environment. In
this work, we report on the determination of beryllium, arsenic, and selenium in the urine of steel production and steel quality
control (QC) workers, in comparison to healthy control subjects. The urine samples were digested by a microwave system. Graphite
furnace and hydride atomic absorption was used for the quantitative measurements of Be and As and Se, respectively. A quality
control method for these procedures was established with concurrent analysis of Standard Trace Metals 7879 Level II and NIST
SRM 2670 (Toxic Elements in Freeze Dried Urine).
The results show that the urinary levels of these elements in steel production (As, 38.1±28.7 μg/L; Be, 1.58±0.46 μg/L, and
Se, 69.2±28.8μg/L) and in quality control workers (As, 23.9±18.1 μg/L; Be, 1.58±0.46 μg/L, and Se, 54.8±25.1 μg/L) are significantly
higher than in the controls (As, 10.3±8.7 μg/L; Be, 0.83±0.46 μg/L; and Se, 32.3±13.5 μg/L).
The possible connection of these elements with the etiology of disease and the possible role of selenium as a protective agent
against the oncogenic and teratogenic action of other substances is discussed. We suggest the need for improvement of environmental
conditions in the workplace through better ventilation and industrial hygiene practices. 相似文献
22.
Prediction of soil depth using a soil-landscape regression model: a case study on forest soils in southern Taiwan 总被引:1,自引:0,他引:1
Tsai CC Chen ZS Duh CT Horng FW 《Proceedings of the National Science Council, Republic of China. Part B, Life sciences》2001,25(1):34-39
Techniques for conventional forest soil surveys in Taiwan need to be further developed in order to save time and money. Although some soil-landscape regression models have been developed to describe and predict soil properties and depths, they have seldom been studied in Taiwan. This study establishes linear soil-landscape regression models related to soil depths and landscape factors found in the forest soils of southern Taiwan. These models were evaluated by validating the models according to their mean errors and root mean square errors. The study was carried out at the 60,000 ha Chishan Forest Working Circle. About 310 soil pedons were collected. The landscape factors included elevation, slope, aspect, and surface stone contents. Sixty percent of the total field samples were used to establish the soil-landscape regression models, and forty % were used for validation. The sampling strategy indicated that each representative pedon covers an area of about 147 ha. The number of samples was appropriate considering the available time and budget. The single variate and/or multivariate linear regression soil-landscape models were successfully established. Those models revealed significant inter-relations among the soil depths of the B and B+BC horizons, solum thickness, and landscape factors, including slope and surface stone contents (p < 0.003). The mean errors in the validation of the soil-landscape model were low and acceptable for this case study. In addition, the slope data derived from the DEM (digital elevation model) database in this case study were used to predict the soil depths of the B, B+BC horizons and the solum thickness without carrying out a field survey. Surface stone should be collected in a field soil survey to increase the precision of soil depth prediction of the B and B+BC horizons, and the solum thickness. 相似文献
23.
Horng YM Huang MC 《Proceedings of the National Science Council, Republic of China. Part B, Life sciences》2000,24(1):41-46
A total of 65 blood samples collected from Holstein cattle were employed for DNA extraction. Genomic DNA were amplified by means of random amplified polymorphic DNA (RAPD). One hundred and one random primers (Operon kits OPAA, OPAO, OPAV, OPC, OPE and OPA-06) were used for polymerase chain reactions (PCR). The PCR products were size fractionated by means of electrophoresis in agarose gel, transferred to a nylon membrane, and then hybridized with a alpha-32P-labeled microsatellite probe for random amplified microsatellite polymorphism (RAMPO) analysis. All the primers produced many amplification patterns in RAMPO fingerprints, but only OPE-01 (5'-CCCAAGGTCC-3') yielded a male-specific strong signal. Among the 65 cases, the specific band could be observed in the RAMPO fingerprints of the 24 male samples but not in the 41 female samples. Therefore, this specific band is peculiar to male cattle. 相似文献
24.
Shan‐Yu Lin Horng‐Huey Ko Shiow‐Ju Lee Hsun‐Shuo Chang Chu‐Hung Lin Ih‐Sheng Chen 《化学与生物多样性》2015,12(7):1057-1067
Bioassay‐guided fractionation of the root of Machilus obovatifolia led to the isolation of four new lignans, epihenricine B ( 1 ), threo‐(7′R,8′R) and threo‐(7′S,8′S)‐methylmachilusol D ( 2 and 3 ), and isofragransol A ( 4 ), along with 23 known compounds. The compounds were obtained as isomeric mixtures (i.e., 2 / 3 and 4 / 20 , resp.). The structures were elucidated by spectral analyses. Among the isolates, 1 , licarin A ( 12 ), guaiacin ( 14 ), (±)‐syringaresinol ( 21 ), and (?)‐epicatechin ( 23 ) showed ABTS (=2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) cation radical‐scavenging activity, with SC50 values of 11.7±0.5, 12.3±1.1, 11.0±0.1, 10.6±0.3, and 9.5±0.2 μM in 20 min, respectively. In addition, kachirachirol B ( 17 ) showed cytotoxicity against the NCI‐H460 cell line with an IC50 value of 3.1 μg/ml. 相似文献
25.
Yi-Chen Hsin Lai-Zhen Zhuang Kuo-Wei Yeh Cheng-Wei Chang Jorng-Tzong Horng Jing-Long Huang 《PloS one》2015,10(6)
Objective
We aimed to determine the risk of tuberculosis in children with juvenile idiopathic arthritis (JIA) in Taiwan.Methods
We used the Taiwan National Health Insurance Research Database (NHIRD) to conduct a nested case-control study. We identified a JIA cohort and matched each JIA child with non-JIA children for comparison. Methotrexate (MTX), tumor necrosis factor (TNF) inhibitor administration, and new tuberculosis cases were determined during our study period. To compare tuberculosis (TB) risk among our study groups, Cox proportional regression models were used to determine adjusted hazard ratios (aHRs).Results
We identified 1495 children with JIA and 11592 non-JIA children. Majority (68.7%) children with JIA had not received MTX or TNF inhibitors; 23.9% used MTX without TNF inhibitors, and 7.4% received TNF inhibitors, irrespective of MTX administration. In total, 43 children developed tuberculosis. The overall tuberculosis infection rate for children with JIA was two times higher than that for non-JIA children. Compared with non-JIA children, children with JIA who used MTX without TNF inhibitors revealed a significantly increased of tuberculosis infection rate (aHR = 4.67; 95% CI: 1.65–13.17; P = 0.004). Children with JIA who either received TNF inhibitors or never used MTX and TNF inhibitors revealed a tuberculosis infection rate comparable to that of non-JIA children.Conclusions
Analysis of nationwide data of Taiwan suggested that children with JIA were at higher risk of tuberculosis compared with those without JIA. 相似文献26.
Shin-Ru Shih Tzu-Yun Chu Gadarla Randheer Reddy Sung-Nain Tseng Hsiun-Ling Chen Wen-Fang Tang Ming-sian Wu Jiann-Yih Yeh Yu-Sheng Chao John TA Hsu Hsing-Pang Hsieh Jim-Tong Horng 《Journal of biomedical science》2010,17(1):13
Background
Influenza viruses are a major cause of morbidity and mortality around the world. More recently, a swine-origin influenza A (H1N1) virus that is spreading via human-to-human transmission has become a serious public concern. Although vaccination is the primary strategy for preventing infections, influenza antiviral drugs play an important role in a comprehensive approach to controlling illness and transmission. In addition, a search for influenza-inhibiting drugs is particularly important in the face of high rate of emergence of influenza strains resistant to several existing influenza antivirals.Methods
We searched for novel anti-influenza inhibitors using a cell-based neutralization (inhibition of virus-induced cytopathic effect) assay. After screening 20,800 randomly selected compounds from a library from ChemDiv, Inc., we found that BPR1P0034 has sub-micromolar antiviral activity. The compound was resynthesized in five steps by conventional chemical techniques. Lead optimization and a structure-activity analysis were used to improve potency. Time-of-addition assay was performed to target an event in the virus life cycle.Results
The 50% effective inhibitory concentration (IC50) of BPR1P0034 was 0.42 ± 0.11 μM, when measured with a plaque reduction assay. Viral protein and RNA synthesis of A/WSN/33 (H1N1) was inhibited by BPR1P0034 and the virus-induced cytopathic effects were thus significantly reduced. BPR1P0034 exhibited broad inhibition spectrum for influenza viruses but showed no antiviral effect for enteroviruses and echovirus 9. In a time-of-addition assay, in which the compound was added at different stages along the viral replication cycle (such as at adsorption or after adsorption), its antiviral activity was more efficient in cells treated with the test compound between 0 and 2 h, right after viral infection, implying that an early step of viral replication might be the target of the compound. These results suggest that BPR1P0034 targets the virus during viral uncoating or viral RNA importation into the nucleus.Conclusions
To the best of our knowledge, BPR1P0034 is the first pyrazole-based anti-influenza compound ever identified and characterized from high throughput screening to show potent (sub-μM) antiviral activity. We conclude that BPR1P0034 has potential antiviral activity, which offers an opportunity for the development of a new anti-influenza virus agent. 相似文献27.
Structural evolution of C-terminal domains in the p53 family 总被引:1,自引:0,他引:1
The tetrameric state of p53, p63, and p73 has been considered one of the hallmarks of this protein family. While the DNA binding domain (DBD) is highly conserved among vertebrates and invertebrates, sequences C-terminal to the DBD are highly divergent. In particular, the oligomerization domain (OD) of the p53 forms of the model organisms Caenorhabditis elegans and Drosophila cannot be identified by sequence analysis. Here, we present the solution structures of their ODs and show that they both differ significantly from each other as well as from human p53. CEP-1 contains a composite domain of an OD and a sterile alpha motif (SAM) domain, and forms dimers instead of tetramers. The Dmp53 structure is characterized by an additional N-terminal beta-strand and a C-terminal helix. Truncation analysis in both domains reveals that the additional structural elements are necessary to stabilize the structure of the OD, suggesting a new function for the SAM domain. Furthermore, these structures show a potential path of evolution from an ancestral dimeric form over a tetrameric form, with additional stabilization elements, to the tetramerization domain of mammalian p53. 相似文献
28.
Horng JC Kotch FW Raines RT 《Protein science : a publication of the Protein Society》2007,16(2):208-215
Collagen is the most abundant protein in animals. Every third residue in a collagen strand is a glycine with phi, psi = -70 degrees, 175 degrees. A recent computational study suggested that replacing these glycine residues with D-alanine or D-serine would stabilize the collagen triple helix. This hypothesis is of substantial importance, as the glycine residues in collagen constitute nearly 10% of the amino acid residues in humans. To test this hypothesis, we synthesized a series of collagen mimic peptides that contain one or more D-alanine or D-serine residues replacing the canonical glycine residues. Circular dichroism spectroscopy and thermal denaturation experiments indicated clearly that the substitution of glycine with D-alanine or D-serine greatly disfavors the formation of a triple helix. Host-guest studies also revealed that replacing a single glycine residue with D-alanine is more destabilizing than is its replacement with L-alanine, a substitution that results from a common mutation in patients with collagen-related diseases. These data indicate that the glycine residues in collagen are not a surrogate for a D-amino acid and support the notion that the main-chain torsion angles of a glycine residue in the native structure (especially, phi > 0 degrees ) are critical determinants for its beneficial substitution with a D-amino acid in a protein. 相似文献
29.
Background
Understanding the adaptive changes that alter the function of proteins during evolution is an important question for biology and medicine. The increasing number of completely sequenced genomes from closely related organisms, as well as individuals within species, facilitates systematic detection of recent selection events by means of comparative genomics. 相似文献30.
Paul DW Kirk Aviva Witkover Alan Courtney Alexandra M Lewin Robin Wait Michael PH Stumpf Sylvia Richardson Graham P Taylor Charles RM Bangham 《Retrovirology》2011,8(1):1-9