Microinjection of salusin-beta into the nucleus tractus solitarii inhibits cardiovascular function by suppressing presympathetic neurons in rostral ventrolateral medulla in rats

Salusin-beta is newly identified bioactive peptide of 20 amino acids, which is widely distributed in hematopoietic system, endocrine system, and the central nervous system (CNS). Although salusin-beta extensively expressed in the CNS, the central cardiovascular functions of salusin-beta are unclear. Our main objective was to determine the cardiovascular effect of microinjection of salusin-beta into the nucleus tractus solitarii (NTS) in anesthetized rats. Bilateral or unilateral microinjection of salusin-beta (0.94-94 microg/rat) into the NTS dose-dependently decreased blood pressure and heart rate. Bilateral NTS microinjection of salusin-beta (9.4 microg/rat) did not alter baroreflex sensitivity. Prior application of the glutamate receptor antagonist kynurenic acid (0.19 microg/rat, n=9) into the NTS did not alter the salusin-beta (9.4 microg/rat) induced hypotension and bradycardia. However, pretreatment with the GABA receptor agonist muscimol (0.5 ng/rat) within the rostral ventrolateral medulla (RVLM) completely abolished the hypotension (-14+/-5 vs. -3+/-5 mm Hg, P<0.05) and bradycardia (-22+/-6 vs. -6+/-5 bpm, P<0.05) evoked by intra-NTS salusin-beta (9.4 microg/rat). In addition, we found that vagotomy didn't influence the actions of salusin-beta (9.4 microg/rat) in the NTS. In conclusion, our present study shows that microinjection of salusin-beta into the NTS significantly produces hypotension and bradycardia, presumably by suppressing the activities of presympathetic neurons in the RVLM.

Analytical criterion for amplitude death in nonautonomous systems with piecewise nonlinear coupling

We investigate the amplitude death phenomenon in a nonautonomous chained network with complicated piecewise nonlinear coupling functions. An analytical criterion for the boundary of the amplitude death region is derived by using the average method. The mechanism of the amplitude death in the nonautonomous networks is very different from that of autonomous systems and rapid dynamic transitions could halt the amplitude death. Numerical verifications are carried out to check jump transitions among different solution branches and further confirm the correctness of the theoretical results.

Antihelminthic niclosamide modulates dendritic cells activation and function

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Effect of niclosamide on the activation of LPS-stimulated BMDCs was investigated.

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Niclosamide decreased ability to stimulate antigen specific T cell proliferation.

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Niclosamide attenuated hapten induced contact hypersensitivity (CHS) in vivo.

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Blocking the MAPK and NF-κB contribute to the inhibitory effect of niclosamide.

Dendritic cells (DCs) link the sensing of the environment by the innate immune system to the initiation of adaptive immune responses. Accordingly, DCs are considered to be a major target in the development of immunomodulating compounds. In this study, the effect of niclosamide, a Food and Drug Administration-approved antihelminthic drug, on the activation of lipopolysaccharide (LPS)-stimulated murine bone marrow-derived DCs was examined. Our experimental results show that niclosamide reduced the pro-inflammatory cytokine and chemokine expression of LPS-activated DCs. In addition, niclosamide also affected the expression of MHC and costimulatory molecules and influenced the ability of the cells to take up antigens. Therefore, in mixed cell cultures composed of syngeneic OVA-specific T cells and DCs, niclosamide-treated DCs showed a decreased ability to stimulate T cell proliferation and IFN-γ production. Furthermore, intravenous injection of niclosamide also attenuated contact hypersensitivity (CHS) in mice during sensitization with 2,4-dinitro-1-fluorobenzene. Blocking the LPS-induced activation of MAPK-ERK, JNK and NF-κB may contribute to the inhibitory effect of niclosamide on DC activation. Collectively, our findings suggest that niclosamide can manipulate the function of DCs. These results provide new insight into the immunopharmacological role of niclosamide and suggest that it may be useful for the treatment of chronic inflammatory disorders or DC-mediated autoimmune diseases.

Structure-activity relationship of potent antimicrobial peptide analogs of Ixosin-B amide

There is a great urgency in developing a new generation of antibiotics and antimicrobial agents since the bacterial resistance to antibiotics have increased dramatically. A series of overlapped peptide fragments of Ixosin-B, an antimicrobial peptide with amino acid sequence of QLKVDLWGTRSGIQPEQHSSGKSDVRRWRSRY, was designed, synthesized and examined for their antimicrobial activities against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. A potent 11-mer peptide TSG-8-1, WWSYVRRWRSR-amide, was developed, which exhibited antimicrobial activity against E. coli and S. aureus while very little hemolytic activity in human erythrocytes was observed at high dose level. This peptide could be further modified for the development of a potent antimicrobial agent in the future.

Efficacy of gradual pressure-decline compressing stockings in Asian patients with lower leg varicose veins: analysis by general measurements and magnetic resonance image

AIM

Most applications of gradual pressure-decline compressing stockings (GPDCS) are used in the United States and Western European countries, with over a decade of clinical experiments. Up to know, there is no standard establishment of gradual pressure-decline compressing stockings for Asian patients with venous insufficiency and varicose vein formations.

METHODS

We collected data on volunteer candidates of varicose vein for general measurements and assessments and magnetic resonance imaging (MRI) by non-contrast enhanced MRV techniques, and for post processing data analysis.

RESULTS

Clinical use of GPCDS provide a mild to moderate improvement in the varicose vein conditions of patients with deep venous insufficiency by improving their deep vein circulation, by general measurements; recording major symptoms and complaint; comfort and stretching/flexibility to the candidates after using GPDCS; and area changes/flow velocity changes/available hemoglobin changes in deep veins monitored by MRI.

CONCLUSION

The benefits and data collected in these results may help in developing compression stockings standards in Taiwanese and Asian countries, and to establishing criterias for product sizes, compression levels, and related parameters.

Hepatitis B surface antigen-antibody interactions studied by optical tweezers

The protein-protein interactions between hepatitis B surface antigen (HBsAg) and its antibodies (anti-HBs) were studied by measuring the binding force between microspheres coated with such proteins using optical tweezers. The interaction force between the protein-coated microspheres was found to be strongly influenced by the acidity of the surrounding liquid medium, as well as the experimental temperature, and it reaches a maximum value at around pH 7.5 and temperature around 37°C. By measuring the protein distribution on the surfaces of the microspheres and their contact areas using scanning electron microscopy, the specific binding force between an HBsAg and anti-HBs protein pair is estimated to be around 4.8 pN at the optimum pH value and temperature at an applied loading rate of around 1 pN/s.

Discovery of potent antimicrobial peptide analogs of Ixosin-B

Antimicrobial peptides (AMPs) represent the first defense line against infection when organisms are infected by pathogens. These peptides are generally good targets for the development of antimicrobial agents. Peptide amide analogs of Ixosin-B, an antimicrobial peptide with amino acid sequence of QLKVDLWGTRSGIQPEQHSSGKSDVRRWRSRY, were designed, synthesized and examined for antimicrobial activities against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Within the peptides synthesized, we discovered an 11-mer peptide, KRLRRVWRRWR-amide, which exhibited potent antimicrobial activity while very little hemolytic activity in human erythrocytes was observed even at high dose level (100 μM). With further modifications, this peptide could be developed into a potent antimicrobial agent in the future.

Effect of posture positions on the evaporative resistance and thermal insulation of clothing

Evaporative resistance and thermal insulation of clothing are important parameters in the design and engineering of thermal environments and functional clothing. Past work on the measurement of evaporative resistance of clothing was, however, limited to the standing posture with or without body motion. Information on the evaporative resistance of clothing when the wearer is in a sedentary or supine posture and how it is related to that when the wearer is in a standing posture is lacking. This paper presents original data on the effect of postures on the evaporative resistance of clothing, thermal insulation and permeability index, based on the measurements under three postures, viz. standing, sedentary and supine, using the sweating fabric manikin-Walter. Regression models are also established to relate the evaporative resistance and thermal insulation of clothing under sedentary and supine postures to those under the standing posture. The study further shows that the apparent evaporated resistances of standing and sedentary postures measured in the non-isothermal condition are much lower than those in the isothermal condition. The apparent evaporative resistances measured using the mass loss method are generally lower than those measured using the heat loss method due to moisture absorption or condensation within clothing. STATEMENT OF RELEVANCE: The thermal insulation and evaporative resistance values of clothing ensembles under different postures are essential data for the ergonomics design of thermal environments (e.g. indoors or a vehicle's interior environment) and functional clothing. They are also necessary for the prediction of thermal comfort or duration of exposure in different environmental conditions.

Synthesis and evaluation of 3-aroylindoles as anticancer agents: metabolite approach

BPR0L075 (2) is a potential anticancer drug candidate designed from Combretastatin A-4 (1) based on the bioisosterism principle. Metabolites of 2, proposed from in vitro human microsome studies, were synthesized, leading to the identification of metabolite-derived analogue 10 with 40-350 pM potency against various cancer cell lines. Insights gained from the major inactive metabolite of 2 led to the development of 29, with better pharmacokinetics and improved potency in the tumor xenograft model than 2.

Generation of ligand-based pharmacophore model and virtual screening for identification of novel tubulin inhibitors with potent anticancer activity

A pharmacophore model, Hypo1, was built on the basis of 21 training-set indole compounds with varying levels of antiproliferative activity. Hypo1 possessed important chemical features required for the inhibitors and demonstrated good predictive ability for biological activity, with high correlation coefficients of 0.96 and 0.89 for the training-set and test-set compounds, respectively. Further utilization of the Hypo1 pharmacophore model to screen chemical database in silico led to the identification of four compounds with antiproliferative activity. Among these four compounds, 43 showed potent antiproliferative activity against various cancer cell lines with the strongest inhibition on the proliferation of KB cells (IC(50) = 187 nM). Further biological characterization revealed that 43 effectively inhibited tubulin polymerization and significantly induced cell cycle arrest in G(2)-M phase. In addition, 43 also showed the in vivo-like anticancer effects. To our knowledge, 43 is the most potent antiproliferative compound with antitubulin activity discovered by computer-aided drug design. The chemical novelty of 43 and its anticancer activities make this compound worthy of further lead optimization.

Microarray analysis of multiple candidate genes and associated plasma proteins for nephropathy secondary to type 2 diabetes among Chinese individuals

AIMS/HYPOTHESIS

Evolving research suggests that common and rare alleles jointly constitute the genetic landscape of complex disease. We studied the association between 43 pathway-related candidate genes with 'intermediate phenotype' (i.e. corresponding plasma protein) and diabetic nephropathy in a customised microarray of 1,536 SNPs.

METHODS

In this case-control study of type 2 diabetic Chinese individuals with and without diabetic nephropathy, cases (n = 545) were defined on the basis of a spot urinary albumin/creatinine ratio (ACR) > 113 mg/mmol; the value for controls (n = 503) was ACR < 3.3 mg/mmol. Genotyping was performed using Illumina GoldenGate assay.

RESULTS

No single nucleotide polymorphism (SNP) remained significant in single locus analysis after correction for multiple testing. Therefore, we explored the best approximately 1% SNPs. Of these 13 SNPs, four clustered to a 5' end NADPH oxidase homologue 4 (NOX4) haplotype (GGCC frequency = 0.776) with estimated OR for diabetic nephropathy of 2.05 (95% CI 1.04-4.06) (heterozygous) and 2.48 (1.27-4.83) (homozygous) (p = 0.0055). The haplotype was correlated with plasma Cu/Zn superoxide dismutase (SOD) concentration, suggesting increased oxidative burden. Endothelin-1 SNP (rs1476046G>A, frequency = 0.252) was correlated with plasma C-terminal pro-endothelin-1 concentrations with an estimated OR for diabetic nephropathy of (heterozygous) 1.26 (0.96-1.66) and (homozygous) 1.87 (1.13-3.12) (p = 0.0072). Nitric oxide synthase 1 (NOS1) 5' haplotype (TGTC frequency = 0.38) also revealed a suggestive association with diabetic nephropathy: heterozygous 1.26 (0.95-1.67), homozygous 1.57 (1.04-2.35) (p = 0.0073). A rare NADPH oxidase homologue 1 (NOX1)-coding non-synonymous SNP (Arg315His, frequency = 0.006) was found exclusively among cases.

CONCLUSIONS/INTERPRETATION

Our preliminary observations suggest that common haplotypes from NOX4 and endothelin-1 SNP correlated with plasma Cu/Zn SOD and C-terminal pro-endothelin-1 concentrations, respectively, and might have conferred diabetic nephropathy susceptibility. Common NOS1 and rare NOX1 variants also revealed a suggestive association with diabetic nephropathy. Future studies to validate our observation are needed.

First Report of Rhizoctonia Blight of a Coastal Redwood Tissue-Culture-Derived Saplings Caused by Rhizoctonia solani AG-IV in Taiwan

Coastal redwood (Sequoia sempervirens (D. Don) Endl.) is native to North America. This tall tree species is used for forestation and lumber; its wood is also used for furniture, its burls for art ware, and its bark for fuel, insulation, and mulch. In August 2005, an instance of wilt was observed among 2-year-old tissue-culture-cloned plants (2) in the Sitou Forest of central Taiwan. Essentially, all plants were infected. The leaves or stems near the ground were affected first, but the wilt soon spread over the entire plant with the leaves becoming grayish brown and water soaked, and then wilting, drying, and finally defoliation occurred. Aerial hyphae were present over the affected areas, aerial mycelium was cob-web-like, hyaline, later becoming slightly brown. Hyphae were 6.5 to 10.4 μm wide with right-angle branching and septal constriction at their bases. Sclerotia were hemispherical, subglobose, to irregular in shape, 1 to 2 mm, and brown. The perfect stage of the fungus was not found. The fungus was identified as Rhizoctonia solani Kühn (3). Vegetative cells were stained with alkaline safranin solution and identified as multinucleate (1). Portions of the stem that displayed symptoms, together with adjacent healthy tissue, were disinfested for 1 min in 0.5% NaOCl and plated on to potato-dextrose agar (PDA) (Merck, Darmstadt, Germany) supplemented with 100 mg/L of ampicillin (Sigma, St. Louis, MO). Single hyphal tips were transferred to PDA and two isolates were established as pure cultures. On the basis of hyphal anastomosis with AG-IV tester isolates (exfop234, exfop241, and exfop250) (1), the fungus was identifed as R. solani AG-IV. Pathogenicity of the fungal isolates was confirmed by inoculating 2-month-old tissue-culture-derived S. sempervirens plants that were grown in pots and incubated in a growth chamber maintained at 28°C with a relative humidity above 95%. Inoculum consisted of a single mycelial 5-day-old 0.5-cm disc grown on PDA of the pathogen placed on the soil surface touching the base of each plant. Four plants were inoculated with mycelium and the four control plants were noninoculated. Inoculated plants wilted gradually over 4 days and all plants developed severe stem rot and were dead in 6 days, whereas control plants remained symptomless. The Rhizoctonia solani AG-IV was reisolated from all inoculated plants. This fungus has been observed to cause disease in many species of plants (4), but to our knowledge, this is the first report of Rhizoctonia blight of coastal redwood tissue-culture-derived saplings caused by Rhizoctonia solani AG-IV in Taiwan. References: (1) T. T. Chang. Taiwan J. For. Sci. 12:47, 1997. (2) L. C. Huang et al. Plant Physiol. 98:166, 1992. (3) B. Sneh et al. Identification of Rhizoctonia species. The American Phytopathological Society, St. Paul, MN, 1991. (4) S. T. Su et al. List of Plant Diseases in Taiwan. The Phytopathological Society of the Republic of China, 2002.

Biotransformation of 6-methoxy-3-(3',4',5'-trimethoxy-benzoyl)-1H-indole (BPR0L075), a novel antimicrotubule agent, by mouse, rat, dog, and human liver microsomes

6-Methoxy-3-(3',4',5'-trimethoxy-benzoyl)-1H-indole (BPR0L075) is a novel synthetic indole compound with microtubule binding activity. Incubation of BPR0L075 with mouse, rat, dog, and human liver microsomes in the presence of NADPH resulted in the formation of six metabolites. Liquid chromatography-tandem mass spectrometry and comparison with the synthetic reference standards identified two metabolites (M1 and M5) as the products derived from hydroxylation on the indole moiety of the molecule. M3 was also identified as a product derived from hydroxylation, but the structure of this metabolite was not identified because of the lack of a reference standard. M2, M4, and M6 were identified as the products derived from O-demethylation. M2, 6-desmethyl-BPR0L075, was the major metabolite formed by the liver microsomes of the four species. No qualitative species difference in the metabolism of BPR0L075 was observed. There was quantitative species difference in the metabolism of BPR0L075 among the four species. Whereas mouse and rat liver microsomes metabolized BPR0L075 predominantly via O-demethylation, dog liver microsomes metabolized BPR0L075 by O-demethylation and hydroxylation to about the same extent. The rank order of intrinsic clearance rates for the conversion of BPR0L075 to 6-desmethyl-BPR0L075 was mouse > rat > human > dog. Incubation of BPR0L075 with baculovirus-insect cell-expressed human cytochrome P450 (P450) isozymes showed that CYP1A2, 2C9, 2C19, 2D6, 2E1, and 3A4 all catalyzed the O-demethylation and hydroxylation of BPR0L075 but to a different degree. Among the six P450 isozymes tested, CYP1A2 and 2D6 were most active on catalyzing the metabolism of BPR0L075. CYP1A2 catalyzed mainly the formation of M1, M2, and M3. M2 was the predominant metabolite formed by CYP2D6.

Reuse potential analysis on WWTP effluent of industrial parks in Taiwan

This study examined the reuse potential of the effluents discharged from several unified wastewater treatment plants (WWTPs) of industrial parks in Taiwan, with designed capacity exceeding 10,000 CMD. Parameters were selected based on the relevant reuse purposes. The "potential recycling percentage", R of the WWTP effluent was defined as the maximal percentage of pure water extractable by the "ideal reverse osmosis module" while the RO retentate still met local effluent standards and required no treatment. The analytical results demonstrated that the WWTP effluents had potential for recycling. A pilot plant was installed in one of the WWTPs. The treatment process included a sand filter, an ultrafiltration unit (UF) and a reverse osmosis module (RO). Results of this study demonstrated that the production quantity and quality are stable and appropriate for various purposes, including both industrial and domestic applications.

Relationship between common functional polymorphisms of the p22phox gene (-930A > G and +242C > T) and nephropathy as a result of Type 2 diabetes in a Chinese population

OBJECTIVE

Genetic determinants are important in diabetic nephropathy (DN). Oxidative stress has also emerged as an important pathogenic factor in DN and vascular NADH oxidase is a major source of reactive oxygen species (ROS). Previous small studies reported a strong but contradictory association between functional genetic variation of p22(phox), an important subcomponent of NADH oxidase, and DN. We investigated the association between two common functional single nucleotide polymorphisms (SNPs) (-930 A > G and +242 C > T) and DN in a much larger group of Chinese patients with Type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Case-control study of Chinese subjects with long-standing T2DM (> 10 years). Cases (n = 306) were subjects with a spot urinary albumin : creatinine ratio (ACR) of > 113 mg/mmol or elevated serum creatinine. Control subjects (n = 306) had ACR < 3.3 mg/mmol and normal serum creatinine. Genotyping was carried out by standard PCR and restriction fragment length polymorphism analysis.

RESULTS

Gender distribution, age, duration of diabetes and HbA(1c) were similar in cases and control subjects. Distribution of genotypes in the control subjects for both SNPs was consistent with the Hardy-Weinberg equilibrium. Distribution of genotypes did not differ significantly between cases and control subjects for both polymorphisms-+2424C > T: cases CC 84.6%, CT 15.0%, TT 0.4% and control subjects CC 87.6%, CT 11.8%, TT 0.6% (P = 0.45); -930 A > G: cases AA 40.5%, AG 41.8%, GG 17.7% and control subjects AA 38.2%, AG 49.0%, GG 12.8% (P = 0.12). Distribution of alleles was also similar-+2424 C > T: cases C 92.2%, T 7.8% and control subjects C 93.5%, T 6.5% (P = 0.66); -930 A > G cases A 61.4%, G 38.6% and control subjects A 62.7%, G 37.3% (P = 0.38). We estimated that our study has approximately 80% power to detect a relative risk of 1.65 (for +242 C > T) and 1.35 (for -930 A > G) conferred by the minor allele, respectively.

CONCLUSIONS

In contrast with previous small studies, our data suggest that these SNPs do not confer significantly increased susceptibility to DN secondary to T2DM in Chinese subjects.

Antiviral drug discovery against SARS-CoV

Severe Acute Respiratory Syndrome (SARS) is a life-threatening infectious disease caused by SARS-CoV. In the 2003 outbreak, it infected more than 8,000 people worldwide and claimed the lives of more than 900 victims. The high mortality rate resulted, at least in part, from the absence of definitive treatment protocols or therapeutic agents. Although the virus spreading has been contained, due preparedness and planning, including the successful development of antiviral drugs against SARS-CoV, is necessary for possible reappearance of SARS. In this review, we have discussed currently available strategies for antiviral drug discovery and how these technologies have been utilized to identify potential antiviral agents for the inhibition of SARS-CoV replication. Moreover, progress in the drug development based on different molecular targets is also summarized, including 1) Compounds that block the S protein-ACE2-mediated viral entry; 2) Compounds targeting SARS-CoV M(pro); 3) Compounds targeting papain-like protease 2 (PLP2); 4) Compounds targeting SARS-CoV RdRp; 5) Compounds targeting SARS-CoV helicase; 6) Active compounds with unspecified targets; and 7) Research on siRNA. This review aims to provide a comprehensive account of drug discovery on SARS. The experiences with the SARS outbreak and drug discovery would certainly be an important lesson for the drug development for any new viral outbreaks that may emerge in the future.

A combined phage display ScFv library against Myxobolus rotundus infecting crucian carp, Carassius auratus auratus (L.), in China

Immunological methods have been developed for the diagnosis of Myxobolus rotundus but their use has been limited for the prevention and therapy of this serious parasitic pathogen. Phage display antibody libraries are a powerful technique for the development of antibodies to molecules of interest and have advantages over traditional hybridroma approaches. In the present study, four antigen fractions related to M. rotundus were prepared and a combined phage display single-chain antibody fragments (ScFv) library was constructed against this parasite. Preliminary analysis indicated that a combined antibody library of about 2.08 x 10(5) individual clones and high diversity was generated. After four rounds of screening (bio-panning) against soluble spore protein prepared from lysed, intact, mature M. rotundus spores, a strain monoclonal phage display ScFv, termed pCAN-6H9, with better affinity, was isolated. The pCAN-6H9 gene fragment was sequenced and analysed. The specificity of pCAN-6H9 was further demonstrated by dot-blot. In competition enzyme-linked immunosorbent assay, both the original and enriched phage-displayed ScFv repertoire showed significant inhibition of mouse anti-M. rotundus serum binding to coated antigen, while the inhibition rate of monoclonal pCAN-6H9 phage particles was only 11.83%.

Intercalation into the DNA double helix and in vivo biological activity of water-soluble planar [Pt(diimine)(N,N-dihydroxyethyl-N'-benzoylthioureato)]+Cl- complexes: a study of their thermal stability, their CD spectra and their gel mobility

The interaction of newly synthesised water-soluble planar complexes of general structure [Pt(diimine)(N,N-dihydroxyethyl-N'-benzoylthioureato)]+Cl- with DNA was investigated by means of DNA melting studies, CD spectroscopy, and DNA gel mobility studies. Addition of stoichometric amounts of [Pt(diimine)H2L-S,O]Cl complexes to polynucleotides caused a significant increase in the melting temperature of poly(dA-dT) and calf-thymus DNA, respectively, indicating that these complexes interacted with DNA and stabilised the double helical structure. The CD spectra confirmed the relatively strong binding of three related Pt(II) complexes ([Pt(2,2'-bipyridine)H2L-S,O]Cl, [Pt(4,4'-dimethyl-2,2'-bipyridine)H2L-S,O]Cl, and [Pt(1,10-phenanthroline)H2L-S,O]Cl), to DNA. Comparison with the published CD spectra of ethidium bromide/DNA complex suggests a similar intercalation mode of binding. cis-[(4,4'-di-tert-butyl-2,2'-bipyridyl)N,N-di(2-hydroxyethyl)-N'-benzoylthioureatoplatinum(II)] chloride, with its very bulky tert-butyl groups, did not intercalate into the polynucleotide double helix. In DNA mobility studies in the presence of the four [Pt(diimine)H2L-S,O]Cl complexes, only [Pt(2,2'-bipyridine)H2L-S,O]Cl affected the DNA mobility to any detectable extent. Finally, in vivo studies on the biological activity of the complexes, using an Escherichia coli DNA excision repair deficient uvrA mutant strain, indicated that only the [Pt(2,2'-bipyridine)H2L-S,O]Cl complex showed significant cellular toxicity and that this was, in part, linked to DNA damage.

Synthesis and anti-viral activity of a series of sesquiterpene lactones and analogues in the subgenomic HCV replicon system

Hepatitis C virus (HCV) infection is a severe liver disease that often leads to liver cirrhosis and hepatocellular carcinoma (HCC). Current therapy is inadequate to conquer this viral disease. In this study, we identified parthenolide (1), an active component in feverfew, a popular remedy for fever and migraine, as a lead compound with an EC50 value of 2.21 microM against HCV replication in a subgenomic RNA replicon assay system. Parthenolide is able to potentiate the interferon alpha-exerted anti-HCV effect. Several commercially available sesquiterpene lactones (2-5) structurally analogous to parthenolide and a series of synthesized Michael-type adducts of parthenolide (12-18) also exhibit micromolar concentrations for anti-HCV activities. Structure-activity relationship was elucidated to reveal that the spatial arrangement of the terpenoid skeleton fused with an alpha-methylene-gamma-lactone moiety produces maximal anti-HCV activity. In addition, a strong anti-HCV potency indicates a possibility of secondary amino adducts (12-18) converting back to parthenolide or being replaced by the nucleophilic residues of proteins inside cells. This work shows that screening of natural products is a viable and fast way for identifying novel molecular diversity as potential drug leads.

Modulation of inactivation by mutation N588K in KCNH2: A link to arrhythmogenesis in short QT syndrome

OBJECTIVE

Short QT syndrome (SQTS) is characterized by ventricular arrhythmias and sudden death. One form of SQTS is caused by mutation N588K in human ether-a-go-go-related gene (HERG). In this study we sought to determine the potential role of N588K in arrhythmias.

METHODS

We measured the characteristics of HERG current generated by wild-type (WT) KCNH2 and the N588K mutant channel expressed in mammalian TSA201 cells.

RESULTS

Whole-cell patch-clamp recordings of WT HERG currents showed the usual rapid onset of inactivation (rectification) at potentials more positive than +10 mV. In contrast, N588K currents rectified at potentials over +80 mV. Over the physiological range of potentials, N588K currents do not inactivate. During an action potential clamp, WT currents displayed a "hump" like waveform with slow activation kinetics and a rapid increase during phase 3 repolarization. In contrast, N588K currents were proportional to the amplitude of the action potential and displayed a dome-like configuration and a much larger current during the initial phases in the ventricle. Purkinje cell action potentials display a more negative phase 2 repolarization than the ventricle and elicited much smaller WT and N588K currents of similar amplitudes.

CONCLUSIONS

Physiologically the N588K mutation abolishes rectification of HERG currents and specifically increases I(Kr) in the ventricle with minimal effects on the Purkinje fiber action potential duration. Such preferential prolongation may explain the separation of the T and U waves observed in the ECG of SQTS patients and lead to re-excitation of the ventricle endocardium.

Emergency management and infection control in a radiology department during an outbreak of severe acute respiratory syndrome

The World Health Organization classified Taiwan as a serious epidemic-stricken area when the extent of severe acute respiratory syndrome (SARS) in Taiwan became clear. As of 11 July 2003, 671 probable SARS cases had been identified in Taiwan and 7 healthcare workers had died from the disease. Radiographers were easily infected by SARS because they had close contact with suspected or probable cases while conducting chest X-ray examinations. Three radiographers had been infected by the end of May 2003. Because of the impact of SARS on the Radiology Department, the department established a SARS emergency infection control team and re-designed the department's infection-control and emergency-management procedures based on the concept of risk-grade protection. This effort included installing a radiographic room at the fever-screening station, re-allocating human resources in the Radiology Department, training the department staff in infection control, and drafting new operational procedures for radiographers conducting X-ray examinations on SARS patients. The goal of this program was to reduce the infection rate and distribute materials efficiently in the department. This article introduces the emergency-management procedure of the Radiology Department during the SARS outbreak and the infection-protection experience of the department staff.

Compaction mechanism and tablet strength of unlubricated and lubricated (silicified) microcrystalline cellulose

This paper describes the differences in compaction properties between microcrystalline cellulose (MCC) and microcrystalline cellulose co-processed with colloidal silicon dioxide (SMCC). The different compaction parameters are not only compared for the pure materials, but also for the lubricated powders with magnesium stearate. Neither magnesium stearate, nor colloidal silicon dioxide, facilitates extensively the densification of (silicified) microcrystalline cellulose during compaction. The difference in tablet relaxation of MCC and SMCC indicates a small negative effect of colloidal silicon dioxide on the interparticle bonding strength of unlubricated MCC. However, for lubricated MCC a larger increase in tablet relaxation at a high compression speed was found than for lubricated SMCC tablets. Accordingly, the decrease in tablet strength was larger for the MCC tablets than for the SMCC tablets when lubrication was applied. The examination of the tablet strengths of tablets compressed from physical mixtures of MCC with increasing concentrations of colloidal silicon dioxide proved the slightly negative influence of silicon dioxide on the tablet strength of unlubricated MCC tablets and the positive effect of colloidal silicon dioxide addition on the tensile strength of lubricated MCC tablets. Co-processing of MCC with colloidal silicon dioxide showed no extra contribution on the tablet strength of lubricated tablets above the physical mixtures. The interactions between the different materials were further supported by the interaction parameters based on partial solubility parameters.

Humoral immune responses of the grouper Epinephelus akaara against the microsporidium Glugea epinephelusis

The humoral immune responses of grouper Epinephelus akaara to a natural infection with Glugea epinephelusis was studied by ELISA utilizing intact mature spores as the coated antigen. Results showed that a specific humoral immune response was elicited, but the intensity of infection (in terms of the number of cysts) was not related to the antibody level in naturally infected hosts. The differences in the antigenicity of intact mature spores and soluble spore proteins derived from cracked mature spores were also analyzed. Results suggested that similar antigen epitopes existed between the 2 groups. Additionally, antigen component patterns and the distribution of antigen with immunogenicity were investigated by using the western blot and the immunofluorescent antibody technique (IFAT). The new parasitic microsporidium has specific polypeptide patterns comparable to the reported fish microsporidians. The main antigenic substances are concentrated on the surface of spores, and are mostly located on the anterior and posterior end of the spore bodies. Most surface components of the G. epinephelusis spores are soluble. The potential role of the surface components in initiating infection was also discussed.

Molecular orientation of evaporated pentacene films on gold: alignment effect of self-assembled monolayer

Pentacene films deposited on self-assembled monolayers (SAMs) bearing different terminal functional groups have been studied by reflection-absorption IR, grazing angle XRD, NEXAFS, AFM, and SEM analyses. A film with pentacene molecules nearly perpendicularly oriented was observed on Au surfaces covered with an SAM of alkanethiol derivative of X-(CH2)(n)-SH, with X = -CH(3), -COOH, -OH, -CN, -NH(2), C(60), or an aromatic thiol p-terphenylmethanethiol. On the other hand, a film with the pentacene molecular plane nearly parallel to the substrate surface was found on bare Au surface. A similar molecular orientation was found in thinner ( approximately 5 nm) and thicker (100 nm) deposited films. Films deposited on different surfaces exhibit distinct morphologies: with apparently smaller and rod-shaped grains on clean bare Au surface but larger and islandlike crystals on SAM-modified surfaces. X-ray photoemission electron microscopy (X-PEEM) was used to analyze the orientation of pentacene molecules deposited on a SAM-patterned Au surface. With the micro-NEXAFS spectra and PEEM image analysis, the microarea-selective orientation control on Au was characterized. The ability to control the packing orientation in organic molecular crystals is of great interest in fabricating organic field effect transistors because of the anisotropic nature of charge transport in organic semiconducting materials.

Contribution of neuronal sodium channels to the cardiac fast sodium current is greater in dog heart Purkinje fibers than in ventricles

OBJECTIVE

To determine the presence and the potential contribution of neuronal sodium channels to dog cardiac function.

METHODS

We used a combination of electrophysiological (patch clamp), RT-PCR, biochemical and immunohistochemical techniques to identify and localize neuronal Na(+) channels in dog heart and determine their potential contribution to the fast sodium current.

RESULTS

In all cardiac tissues investigated, Na(v)1.1, Na(v)1.2 and Na(v)1.3 transcripts were detected. In immunoblots, we found Na(v)1.1 and Na(v)1.2 proteins in the ventricle (V) and in Purkinje fibers (PF). Na(v)1.3 immunoblots suggested strong proteolytic activity against this isoform in the heart. Na(v)1.6 was not found in any of the tissues tested. Confocal immunofluorescence on cardiac myocytes showed that Na(v)1.1 was predominantly localized at the intercalated disks in V and PF and around the nucleus (V). Na(v)1.2 was only present at the Z lines (V). Consistent with the immunoblot data, an intense but diffuse intracellular staining was observed for Na(v)1.3. Na(v)1.6 fluorescence staining was faint and diffuse. Surprisingly, immunoblots indicated the presence of two Na(v)beta 2 variants: a 42-kDa protein that co-localized with Na(v)1.2 at the Z lines in V and a 34-kDa protein that co-localized with Na(v)1.1 at the intercalated disks in PF. In agreement with the biochemical data, electrophysiological results suggest that neuronal sodium channels generate 10+/-5% and 22+/-5% of the peak sodium current in dog ventricle and Purkinje fibers, respectively.

CONCLUSIONS

Our results suggest that neuronal NaChs are more abundant in Purkinje fibers than in ventricles, and this suggests a role for them in cardiac conduction.

[Expression and immunocompetence characterization of Plasmodium falciparum lactate dehydrogenase]

OBJECTIVE

To express lactate dehydrogenase (LDH) gene of Plasmodium falciparum FCC1/HN in the E. coli TG1 and analyse its immunocompetence.

METHODS

The LDH gene of the P. falciparum was specifically amplified by polymerase chain reaction, and the recovered gene fragment was cloned into pGEX-4T-1 vector for expression of fusion protein with glutathione S-transferase(GST). The recombinant plasmid was transformed into the E. coli TG1. Four mice (Kunming strain) were immunized with purified expressed protein(antigen) and the polyclonal antibodies were collected. The immunocompetence of recombinant protein was analysed by ELISA and Western-blot.

RESULTS

The LDH gene of P. falciparum was successfully expressed in the E. coli TG1. The expressed protein exhibited a specific reaction with immune sera obtained from rabbits immunized with P. falciparum. The specific humoral responses were induced in mice and the titer of the specific antibody was 1:16 by two-dimensional diffusion assay.

CONCLUSION

The LDH gene of P. falciparum has been successfully expressed in the E. coli TG1 and the expressed protein has high antigencity.

[Preparation and characterization of McAbs against lactate dehydrogenase of Plasmodium falciparum]

OBJECTIVE

To prepare and characterize the monoclonal antibodies(McAbs) against lactate dehydrogenase of the Plasmodium falciparum(LDHp).

METHODS

BALB/c mice were immunized with purified recombinant LDHp and McAbs against LDHp were prepared according to the protocol of hybridoma technique. The McAbs were characterized by ELISA and Western blot analysis.

RESULTS

Two McAbs against LDHp antigen were obtained. Both McAbs were IgG2b. The titer of two McAbs(2A5, 1H10) in the ascites was 1:25,600 and 1:12,800, and in supernatant were 1:512,1:256 respectively. The result of ELISA indicated that two McAbs reacted only with P. falciparum, and did not react with normal human red blood cells, P. vivax, Toxoplasma gondii, Schistosoma japonicum. It is recognized 33 kDa protein which was defined as LDHp by Western blot analysis.

CONCLUSION

Two hybridoma cell lines secreting high titer of McAbs against LDHp with high specificity were established.

Estimation of percolation flux from borehole temperature data at Yucca Mountain, Nevada

Temperature data from the unsaturated zone (UZ) at Yucca Mountain are analyzed to estimate percolation-flux rates and overall heat flux. A multilayer, one-dimensional analytical solution is presented for determining percolation flux from temperature data. Case studies have shown that the analytical solution agrees very well with results from the numerical code, TOUGH2. The results of the analysis yield percolation fluxes in the range from 0 to 20 mm/year for most of the deep boreholes. This range is in good agreement with the results of infiltration studies at Yucca Mountain. Percolation flux for the shallower boreholes, however, cannot be accurately determined from temperature data alone because large gas flow in the shallow system alters the temperature profiles. Percolation-flux estimates for boreholes located near or intersecting major faults are significantly higher than those for other boreholes. These estimates may be affected by gas flow in the faults.

Coordinated down-regulation of KCNQ1 and KCNE1 expression contributes to reduction of I(Ks) in canine hypertrophied hearts

OBJECTIVE

In animal models of hypertrophy, electrical remodeling giving rise to QT prolongation occurs rapidly and is associated with the development of torsade de pointes (TdP) arrhythmias and sudden death. Chronic AV block (CAVB)-induced hypertrophy in dogs has been associated with a reduction in the slow component (I(Ks)) of the delayed rectifier potassium current (I(K)), which contributes to a prolongation of ventricular repolarization, the development of an acquired form of long QT, and the substrate for triggered activity and TdP. The present study was designed to probe the molecular basis for the decrease in I(Ks) by studying the characteristics of KCNE1 and KCNQ1, the putative genes responsible for formation of the channel.

METHODS AND RESULTS

Using a combination of Northern blot, competitive multiplex PCR and immunoblot assays, we found that CAVB reduces KCNE1 and KCNQ1 RNA in the canine ventricles by 70 and 80%, respectively. Protein levels of KCNE1 and KCNQ1 were reduced by 60 and 50%, respectively. We also demonstrate at the molecular level the basis for inter-ventricular difference in I(Ks) density previously reported in hearts of normal dogs and show the basis for reduction of this difference in the CAVB dog.

CONCLUSIONS

Our results indicate that the CAVB-induced reduction in I(Ks) is due to a down-regulation of KCNE1 and KCNQ1 transcription. The data suggest that electrical remodeling of the cardiac ventricle during hypertrophy involves regulation of the gene expression through modulation of transcriptional and translational regulatory pathways. The reduction in KCNE1 and KCNQ1 expression increases the dependence of ventricular repolarization on the rapid component of I(K) and may potentiate the action of Class III antiarrhythmic agents.

Dimensional analysis for establishing the testing criteria of kinetic study with respirometry

The kinetic study of a microbial system requires the determination of kinetic parameters under a set of operating variables. Previous researchers indicated that initial conditions, such as S0/X0 and S0/KS may influence the reliability of the parameter estimation. However, little study has been done to identify the sensitivity of system variables to the parameter estimation. This study proposes a novel dimensional analysis and identifies six dimensionless groups: mu(m)/fw, kd/fw, Yg, S0/KS, KS/S0, and 1/(fw theta(c) - 1). By incorporating the SP-moving algorithm proposed by Wu and coworkers in 2001, an algorithm was proposed in this study to perform a sensitivity analysis on the six dimensionless groups. Results of this analysis reveal that S0/X0 is more sensitive than S0/KS, as also evidenced by the fact that gross growth yield (Yg) is sensitive and affecting S0/X0. The analysis also suggests that the theta(c)-based wasting frequency (fw theta(c)) is more sensitive than the daily wasting frequency (fw). A critical minimum value of 1.3 for S0/X0 and a maximum value of 0.1 for S0/KS were suggested to establish the testing criteria for the kinetic study under the respirometric conditions.

Functional expression of GFP-linked human heart sodium channel (hH1) and subcellular localization of the a subunit in HEK293 cells and dog cardiac myocytes

Recent evidence suggests that biosynthesis of the human heart Na+ channel (hH1) protein is rapidly modulated by sympathetic interventions. However, data regarding the intracellular processing of hH1 in vivo are lacking. In this study we sought to establish a model that would allow us to study the subcellular localization of hH1 protein. Such a model could eventually help us to better understand the trafficking of hH1 in vivo and its potential role in cardiac conduction. We labeled the C-terminus of hH1 with the green fluorescent protein (GFP) and compared the expression of this construct (hH1-GFP) and hH1 in transfected HEK293 cells. Fusion of GFP to hH1 did not alter its electrophysiological properties. Confocal microscopy revealed that hH1-GFP was highly expressed in intracellular membrane structures. Immuno-electronmicrographs showed that transfection of hH1-GFP and hH1 induced proliferation of three types of endoplasmic reticulum (ER) membranes to accommodate the heterologously expressed proteins. Labeling with specific markers for the ER and the Golgi apparatus indicated that the intracellular channels are almost exclusively retained within the ER. Immunocytochemical labeling of the Na+ channel in dog cardiomyocytes showed strong fluorescence in the perinuclear region of the cells, a result consistent with our findings in HEK293 cells. We propose that the ER may serve as a reservoir for the cardiac Na+ channels and that the transport from the ER to the Golgi apparatus is among the rate-limiting steps for sarcolemmal expression of Na+ channels.

The study of Central Taiwan particles concentration variations during earthquake period

Ambient particle concentration was taken on the traffic sampling site over the Chung-Chi Road over the bridge (CCROB) in front of Hungkuang Institute of Technology (HKIT). The sampling time was from August 1999 to December 1999. During the sampling period, Taiwan's biggest earthquake in more than a century registered 7.3 on the Richter scale (Taiwan Chi-Chi Earthquake). Besides, there are more than 20,000 aftershocks following the Taiwan Chi-Chi Earthquake within 3 months. Thus, the mass concentration of particles with aerodynamic diameters smaller than 2.5 microm (PM2.5) and PM2.5-10 was also collected then compared with the total mass concentration of suspended particles (TSP) in this study. The average TSP, PM2.5-10, and PM2.5 concentrations are 106, 24.6, and 58.0 microg/m3, respectively, after the Taiwan Chi-Chi Earthquake. The average TSP concentrations before and after Taiwan Chi-Chi Earthquake were 69.6 and 127 microg/ m3, respectively. In addition, statistical analysis of the PM10 data from this study and EPA in 1999 yielded a Tstatistic of 0.147, which is smaller than t(0.975,18) = 2.101. It is indicated that there was no significant difference. So, the PM10 concentrations measured after Taiwan Chi-Chi Earthquake in this study were also greater than those data previously obtained from Taiwan EPA in the same region of this area. The relationships between TSP, PM10, PM2.5-10, and PM2.5 particle concentrations and wind speed (R2) are .77, .59, .58, .58, respectively. And the ratios of PM2.5/PM25-10, PM2.5/PM10, and PM10/TSP are 221%, 67.2%, 58.0%, respectively. The average ratios of PM2.5/PM2.5-10 and PM2.5/PM10 increase by about 120% and 17%. It indicated that the fine-particles concentration increases compared to the coarse-particles concentration after 921 Taiwan Chi-Chi Earthquake. And the proposed reasons are that local motor vehicle emissions combined the fine particles transported from the Chi-Chi epicenter. More importantly, the wind direction was mainly blown from southeastern part. These two main factors enhance the fine-particles concentration in this area.

On the selection of primary variables in numerical formulation for modeling multiphase flow in porous media

Selecting the proper primary variables is a critical step in efficiently modeling the highly nonlinear problem of multiphase subsurface flow in a heterogeneous porous-fractured media. Current simulation and ground modeling techniques consist of (1) spatial discretization of mass and/or heat conservation equations using finite difference or finite element methods; (2) fully implicit time discretization; (3) solving the nonlinear, discrete algebraic equations using a Newton iterative scheme. Previous modeling efforts indicate that the choice of primary variables for a Newton iteration not only impacts computational performance of a numerical code, but may also determine the feasibility of a numerical modeling study in many field applications. This paper presents an analysis and general recommendations for selecting primary variables in simulating multiphase, subsurface flow for one-active phase (Richards' equation), two-phase (gas and liquid) and three-phase (gas, water and nonaqueous phase liquid or NAPL) conditions. In many cases, a dynamic variable switching or variable substitution scheme may have to be used in order to achieve optimal numerical performance and robustness. The selection of primary variables depends in general on the sensitivity of the system of equations to the variables selected at given phase and flow conditions. We will present a series of numerical tests and large-scale field simulation examples, including modeling one (active)-phase, two-phase and three-phase flow problems in multi-dimensional, porous-fractured subsurface systems.

Determination of pyruvate and lactate in primary liver cell culture medium during hypoxia by on-line microdialysis–liquid chromatography

A microdialysis sampling device was constructed for the measurement of pyruvate and lactate in primary liver cell culture medium during hypoxia. It was composed of a Petri dish, a dialysis membrane and two transmission tubes within a hypoxia chamber. The dialysis membrane was located in the Petri dish such that it was immersed in the culture medium. Dialysates were collected and introduced by an on-line injector to a liquid chromatographic system for analysis of pyruvate and lactate. The detection limit of this assay was 0.2-2.0 microM with acceptable intra- and inter-assay reproducibilities. In order to validate the assay, primary liver cells were incubated in the Petri dish within a hypoxia chamber in an incubator. The baseline concentrations of pyruvate and lactate in primary liver cell culture medium were 10.6+/-5.6 and 607+/-143 microM, respectively. These levels drastically changed during hypoxia and reperfusion. In conclusion, the present assay provides a sensitive, direct measurement of pyruvate and lactate in culture medium while minimizing pretreatment procedures for sample preparation.

High-performance chiral separation of fourteen triazole fungicides by sulfated beta-cyclodextrin-mediated capillary electrophoresis

In this paper, sulfated beta-cyclodextrin-mediated capillary electrophoresis (CE) is evaluated as a new approach for the chiral separation of triazole-type fungicides. The 14 fungicides investigated were bitertanol, cyproconazole, difenoconazole, diniconazole, flutriafol, hexaconazole, myclobutanil, paclobutrazol, penconazole, propiconazole, tebuconazole, tetraconazole, triadimefon and triadimenol. Under the optimal conditions, excellent enantioseparation was achieved for all the 14 fungicides, including those fungicides containing two chiral centers. To our knowledge, this is the only system to date that offers outstanding enantiodiscrimination towards all triazole-type fungicides. The impact of the molecular structures of the triazole compounds on their migration behavior was studied. Similar to other chemical systems involving host-guest complexation, the interaction between sulfated beta-cyclodextrin and the triazole compounds was found to be affected by a variety of factors, including electrostatic force, hydrogen bonding, steric effect and hydrophobicity. These factors, coupled with the countercurrent electroosmotic flow (EOF), were believed to be the major forces behind the exceptional chiral selectivity.

Full-scale evaluation of heat balance for autothermal thermophilic aerobic treatment of food processing wastewater

A full-scale autothermal thermophilic aerobic treatment (ATAT) of food-processing wastewater was evaluated in this study. The wastewater was rich in oil and grease at concentrations of 1,500-2,000 mg/L. The system has been operated for more than one and a half years since the startup. Under steady state conditions, the ATAT process was capable of spontaneous reaction at temperatures of 45-55 degrees C without the addition of external heat. Treatment efficiency was as high as 95% in COD reduction at a volumetric COD loading of 4.1 kg/m3-d. A mathematical heat balance model was developed based on the theoretical considerations of heat sources and losses for the ATAT process. A computer algorithm was established to evaluate specific heat potential (Hs) of the wastewater under steady state conditions. Six months of steady-state data were used for the evaluation. The result shows that on average the wastewater had a specific heat potential (Hs) of 4,720 kcal/kg-COD removed and the biological heat contributed 41.4% of the total heat input. A net heat flux of 4,270 kcal/min and volumetric heat intensity (Hv) of 38.0 kcal/L was necessary to maintain reaction temperature at 48.2 degrees C for the ATAT process. The full-scale ATAT process showed the typical characteristics of high removal rate, low sludge yield, and poor solids settleability for thermophilic aerobic treatment reported in the literature.

The study of TSP, PM(2.5-10) and PM2.5 during Taiwan Chi-Chi Earthquake in the traffic site of central Taiwan, Taichung

Ambient particle concentration was taken on the traffic sampling site over the Chung-Chi Road over bridge (CCROB) in front of Hungkuang Institute of Technology (HKIT). The sampling time was from August 1999 to December 1999. During the sampling period, Taiwan's biggest earthquake in more than a century registered 7.3 on the Richter scale (Taiwan Chi-Chi Earthquake). Besides, there were more than 20,000 aftershocks that followed the Taiwan Chi-Chi Earthquake within three months. Thus, the PM2.5, PM(2.5-10) particle concentrations were also collected then and compared with total suspended particle (TSP) in this study. The average PM(2.5-10), PM2.5 and TSP concentrations are 24.6, 58.0 and 106 microg/m3, respectively, after the Taiwan Chi-Chi Earthquake. The average TSP concentrations before and after Taiwan Chi-Chi Earthquake were 70 and 127 microg/m3, respectively. It is clearly shown that the average concentration of TSP after Taiwan Chi-Chi Earthquake was about 1.8 times as that of TSP concentration before Taiwan Chi-Chi Earthquake in the traffic site of central Taiwan. And the ratios of PM2.5/PM(2.5-10), PM2.5/PM10 and PM2.5/TSP are 2.2%, 67.2%, 38.9%, respectively. The results also indicated about Chi-Chi fine particle concentration (PM25) and the TSP increases in the traffic site of central Taiwan after Taiwan Chi-Chi Earthquake.

Comparison of particulate mass, chemical species for urban, suburban and rural areas in central Taiwan, Taichung

Aerosol samples for PM2.5, PM(2.5-10) and TSP were collected from June to September 1998 and from February to March 1999 in central Taiwan. Ion chromatography was used to analyze the acidic anions: sulfate, nitrate and chloride in the Universal samples. The ratios of fine particle concentrations to coarse particle concentrations displayed that the fine particle concentrations are almost greater than that of coarse particle concentrations in Taichung area. The average concentrations of PM2.5, PM(2.5-10) and TSP in urban sites are higher than in suburban and rural sites at both daytime and night-time. Chloride dominated in the coarse mode in daytime and in fine mode in night-time. Nitrate can be found in both the coarse and fine modes. Sulfate dominated in fine mode in both daytime and night-time.

The study of fine and coarse particles, and metallic elements for the daytime and night-time in a suburban area of central Taiwan, Taichung

Daily average concentrations of fine and coarse particulates, and TSP samples have been measured simultaneously at daytime and night-time periods by using Universal and PS-1 sampler in a suburban area of central Taiwan from June to August 1998. The samples were analyzed by atomic absorption spectrometry to determine the fine and coarse particulate concentrations of metallic elements (Ca, Fe, Mn, Pb, Cu, Zn and Cr). The concentration of PM2.5 and TSP showed a decreased trend for the daytime period. The fine particle concentrations were about two times as that of coarse particulate concentrations. The averaged fine particulate concentrations at daytime are higher than at night-time. Ca and Fe were mostly in the coarse particulate mode. The correlation coefficients were 0.63 and 0.69 for elements Ca and Fe in the coarse particle mode for day and night periods. Pb showed a similar distribution ratio with Mn for the fine to coarse particle ratios at both day and night period. Pb and Mn are highly correlated for the day (R = 0.78) and night period (R = 0.61) at particle size <2.5 microm. Cu and Zn were mainly in fine particles at both day and night period. Fe and Ca consist of the major parts of all the elements. Elemental Mn is the lowest among the rest of the heavy metals.

A compound heterozygote in the NADH-cytochrome b5 reductase gene from a Chinese patient with hereditary methemoglobinemia type I

To elucidate the mutation in the nicotinamide adenine dinucleotide-cytochrome b5 reductase (b5R) gene from a Chinese patient with hereditary methemoglobinemia type I, we analyzed the coding sequences of b5R cDNA from the patient and from normal subjects by direct sequencing the reverse transcriptase-polymerase chain reaction (RT-PCR) products. The PCR-amplified genomic DNA fragments of the b5R gene from the patient, his mother, and normal controls were analyzed by restriction enzymes MspI and RsaI. A compound heterozygote Arg57Gln (CGG-->CAG)/Cys203Tyr (TGC-->TAC) was found in the b5R gene from the patient, and a CGG-->CAG mutant allele occurred in a chromosome inherited from his mother, while TGC-->TAC occurred in a chromosome inherited from his father. In this report, we discuss a compound heterozygote first observed in the b5R gene from a patient with hereditary methemoglobinemia type I.

A novel mutation in the NADH-cytochrome b5 reductase gene of a Chinese patient with recessive congenital methemoglobinemia

Recessive congenital methemoglobinemia due to nicotinamide adenine dinucleotide (NADH)-cytochrome b5 reductase (b5R) deficiency is classified into 2 clinical types: type 1 (erythrocyte type) and type 2 (generalized type). We found a Chinese family with type 1 recessive congenital methemoglobinemia, the patients from which were diagnosed according to clinical symptoms and b5R enzyme activity in the blood cells. To learn the molecular basis of type 1 recessive congenital methemoglobinemia in this Chinese family, we isolated total RNA from the peripheral leukocytes of the propositus and b5R complementary DNA (cDNA) by reverse transcription- polymerase chain reaction (RT-PCR). The coding region of the b5R cDNA was analyzed by sequencing the cloned PCR products. The results showed that the propositus was homozygous for a G-->A transition at codon 203 in exon 7, changing a cysteine to a tyrosine (Cys203Tyr). To characterize the mutant enzyme, both glutathione S-transferase (GST)-fused wild-type b5R and GST-fused mutant Cys203Tyr b5R were expressed in Escherichia coli and affinity purified. The results showed that the catalytic activity of the enzyme was not much affected by this amino acid substitution, but the mutant enzyme exhibited decreased heat stability and increased susceptibility to trypsin. These properties of the mutant enzyme would account for the restricted b5R deficiency and mild clinical manifestations of these type 1 patients. The finding of this novel mutation makes codon 203 the only position within the b5R gene at which more than 1 mutation has been found.

Simultaneous chiral separation of triadimefon and triadimenol by sulfated beta-cyclodextrin-mediated capillary electrophoresis

Enantiomeric separation of two triazole fungicides, triadimefon and triadimenol, was investigated in sulfated beta-cyclodextrin (sulfated beta-CD)-mediated capillary electrophoresis (CE) systems. It was found that, at pH 2-4, sulfated beta-CD exhibited strong chiral recognition towards both triadimefon and triadimenol. The enantiorecognition was believed to result from the multiple interactions between sulfated beta-CD and the analytes, which included inclusion effect, electrostatic interaction, and hydrogen bonding. Under optimal conditions (phosphate buffer with 2% sulfated beta-CD, pH 2.5), simultaneous resolution of all chiral isomers of triadimefon and triadimenol was achieved in less than half an hour. In conjunction with solvent extraction and subsequent enrichment by solid-phase extraction (SPE), this new enantioseparation method was applied successfully in the study of stereoselectivity associated with the biotransformation of triadimefon to triadimenol by soil microorganisms. The present methodology was superior to the commonly adopted chiral gas chromatography (GC) approach in that a very mild procedure was involved from sample extraction to the ultimate chiral separation. Thus, the disturbance of the enantiomeric distribution patterns of the original soil samples by heat stress was an unlikely scenario. Furthermore, it was discovered that, owing to the unique selectivity of the present separation strategy, there was virtually no interference from the soil matrix, which led to improvements in both sensitivity and selectivity in real sample determination.

Holography and noncommutative yang-mills theory

In this Letter a recently proposed gravity dual of noncommutative Yang-Mills theory is derived from the relations between closed string moduli and open string moduli recently suggested by Seiberg and Witten. The only new input one needs is a simple form of the running string tension as a function of energy. This derivation provides convincing evidence that string theory integrates with the holographical principle and demonstrates a direct link between noncommutative Yang-Mills theory and holography.

Characterization of chemical species in PM2.5 and PM10 aerosols in suburban and rural sites of central Taiwan

Aerosol samples for PM2.5 (particulate matter with aerodynamic diameters less than 2.5 microns), PM2.5-10 (particulate matter with aerodynamic diameters between 2.5 and 10 microns) and TSP were collected from June to September 1998 at THU (suburban) and HKIT (rural) sites in central Taiwan. The ratios of PM2.5/PM10 averaged 0.70 for the daytime and 0.63 for the nighttime at THU, respectively. At HKIT, the PM2.5/PM10 ratios averaged 0.56 for the daytime and 0.72 in the nighttime, respectively. These results indicated that the PM2.5 concentrations contribute the majority of the PM10 concentration and PM10 concentrations contribute the majority of the TSP at both sites. The averaged PM2.5 concentrations at THU are higher than those measured at HKIT during the daytime period. However, the average PM2.5-10 concentrations in THU are lower than those measured at HKIT during nighttime. The samples collected were also analyzed by atomic absorption spectrophotometry for the elemental analysis of Ca, Fe, Pb, Zn, Cu, Mn and Cr. Meanwhile ion chromatography was used to analyze for the water-soluble ions: sulphate, nitrate and chloride in the Universal samples. The concentrations of heavy metals in PM10 during daytime were all higher than nighttime at THU. However, the averaged concentrations of metal elements in PM10 during day and night period were distributed irregularly at HKIT. The results indicated that for metal elements collected at HKIT have different emission sources. The concentrations of metal elements during daytime in PM10 at THU were generally higher than HKIT. The phenomena owing to the averaged PM2.5 particle concentrations at THU (suburban) were higher than those measured at HKIT (rural) and PM2.5 occupied the major portions of PM10 for both sites during the day period. For anion species, there are no significant differences between day and night period in PM10 concentrations at both suburban and rural sites.

The characteristic study of TSP, PM2.5-10 and PM2.5 in the rural site of central Taiwan

The total suspended particle (TSP), PM2.5-10 (aerodynamic diameter less than 10 microns) and PM2.5 concentration (aerodynamic diameter less than 2.5 microns) concentrations were sampled by PS-1 and Universal sampler on the roof (25 m) of the Medical and Engineering Building in the campus of Hungkuang Institute of Technology (HKIT) which is located at a height of 500 m on Da Du Mountain. The results indicated that average TSP, PM2.5-10 and PM2.5 concentrations are 0.42, 0.34 and 0.019 mg/m3 in the day time, respectively and are 0.32, 0.26 and 0.017 mg/m3 in the night time, respectively. The ratios of PM2.5-10/TSP were from 76% to 85% and from 50% to 91% for day and night period, respectively. It indicated that the major composition in the total suspended particles was PM2.5-10 in the rural site. The relationship between TSP and PM2.5-10 is TSP = 1.16PM2.5-10 + 0.027 and TSP = 1.01 PM2.5-10 + 0.058 in the day and night time, respectively. The correlation coefficient (R2) is 0.98 and 0.97 for day and night period, respectively. The relationship between PM2.5-10 and PM2.5 is PM2.5 = 0.0005PM2.5-10 + 0.019 and PM2.5 = 0.037PM2.5-10 + 0.0076 in the day and night period, respectively. The correlation coefficient (R2) is 3E-5 and 0.67 for day and night period, respectively. The relationships between TSP, PM2.5-10, PM2.5 particle concentrations and wind speed (R2) in the day time are 0.71, 0.64, 0.43, respectively and are 0.83, 0.79, 0.57, respectively in the night time. The proposed reasons are that there are more activities caused by people (students) and natural living animals which absorbed some of the particles during the day time. Thus, the correlation coefficients for the night time are better than those of day time. The particle size distributions are both bimodel in the day and night time. The major peaks in the day time appear in the particle diameter between 0.031-0.056 micron and 3.16-5.62 microns in the day period and appear between 0.017-0.031 micron and 1.78-3.16 microns in the night period. The results indicate that the particle size distribution in the day time tends to be of larger particle size mode than the night time.

Pharmacokinetic and pharmacodynamic analyses of trazodone in rat striatum by in vivo microdialysis

The aim of this study was to investigate the brain pharmacokinetics and pharmacodynamics of trazodone. Sensitive microbore high-performance liquid chromatographic methods with electrochemical detection (LC-ED) were developed for the determination of trazodone, serotonin (5-HT), and their respective metabolites. The feasibility of microdialysis coupled with LC-ED system for direct analysis of these compounds in the rat striatum was investigated. Striatal dialysates were automatically injected onto a cyano microbore column, through an on-line injector, for the determination of trazodone and its metabolite or onto a reversed phase microbore column for the determination of 5-HT and its metabolite. A monophase phenomenon with a first-order elimination rate constant was observed for trazodone. The brain pharmacokinetics of trazodone appear to conform to a one-compartment model. Surprisingly, no significant changes in striatal 5-HT or its metabolite were observed following the same dosage and time course. The present results suggest that brain microdialysis methods may be applicable to pharmacokinetic and pharmacodynamic studies of psychotrophic agents.