Development of a one-run real-time PCR detection system for pathogens associated with poultry infectious diseases.

Infectious diseases are an important issue in the poultry industry, requiring early diagnosis and countermeasures. To address this, we present a system based on TaqMan real-time PCR to detect pathogen genome in specimens collected from chickens. We designed 12 primer-probe sets for pathogens causing respiratory or systemic symptoms.

Understanding and Reducing Photothermal Forces for the Fabrication of Au Nanoparticle Dimers by Optical Printing.

Optical printing holds great potential to enable the use of the vast variety of colloidal nanoparticles (NPs) in nano- and microdevices and circuits. By means of optical forces, it enables the direct assembly of NPs, one by one, onto specific positions of solid surfaces with great flexibility of pattern design and no need of previous surface patterning. However, for unclear causes it was not possible to print identical NPs closer to each other than 300 nm.

Efficient Third Harmonic Generation from Metal-Dielectric Hybrid Nanoantennas.

High refractive index dielectric nanoantennas are expected to become key elements for nonlinear nano-optics applications due to their large nonlinearities, low energy losses, and ability to produce high electric field enhancements in relatively large nanoscale volumes. In this work, we show that the nonlinear response from a high-index dielectric nanoantenna can be significantly improved by adding a metallic component to build a metal-dielectric hybrid nanostructure. We demonstrate that the plasmonic resonance of a Au nanoring can boost the anapole mode supported by a Si nanodisk, strongly enhancing the electric field inside the large third-order susceptibility dielectric.

Unidirectional light scattering with high efficiency at optical frequencies based on low-loss dielectric nanoantennas.

Dielectric nanoparticles offer low optical losses and access to both electric and magnetic Mie resonances. This enables unidirectional scattering along the incident axis of light, owing to the interference between these two resonances. Here we theoretically and experimentally demonstrate that an asymmetric dimer of dielectric nanoparticles can provide unidirectional forward scattering with high efficiency.

Switchable directional scattering of electromagnetic radiation with subwavelength asymmetric silicon dimers.

High refractive index dielectric nanoparticles show high promise as a complementary nanophotonics platform due to compared with plasmonic nanostructures low absorption losses and the co-existence of magnetic and electric resonances. Here we explore their use as resonantly enhanced directional scatterers. We theoretically demonstrate that an asymmetric dimer of silicon nanoparticles shows tuneable directional scattering depending on the frequency of excitation.

Adsorption of endotoxins on glass in the presence of cationic proteins.

Endotoxin activity was detected in empty glass tubes where endotoxins were incubated with lysozyme, histone or RNaseA, indicating adsorption of endotoxins on glass in the presence of cationic proteins. In the case of lysozyme, the recovery of spiked endotoxins (90.0%) using polystyrene tubes for incubation was much greater than the recovery (28.

Reversed phase HPLC of Met58 oxidized rhIL-11: oxidation enhanced by plastic tubes.

The hydrophobicity of human recombinant interleukin 11 (rhIL-11) with an oxidized Met58 residue is nearly identical to the hydrophobicity of native rhIL-11. Consequently, separation of these species using standard gradient elution or isocratic elution is very difficult. Using an optimized, shallow gradient RP-HPLC method.

Novel potassium channel activators. III. Synthesis and pharmacological evaluation of 3,4-dihydro-2H-1,4-benzoxazine derivatives: modification at the 2 position.

A new series of 3,4-dihydro-2H-1,4-benzoxazine derivatives, where various substituents were introduced into one of the geminal dimethyl groups at the 2 position, were synthesized and their potassium channel-activating activity was evaluated. Introduction of a hydroxyl group, as in compound 5, resulted in good solubility in water and a long duration of action compared with the parent compound 1. Introduction of a nitrato group, as in compound 8, produced typical nitrate activity such as exhibited by nitroglycerine in addition to potassium channel-activating activity.

Novel potassium channel openers. Part 4: transformation of the 1,4-benzoxazine skeleton into 1,4-benzothiazine, 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroquinoxaline, indoline, and 1,5-benzoxazepine.

As part of a search for a new potassium channel opener, the 1,4-benzoxazine skeleton derived from the benzopyran skeleton of cromakalim, was transformed into other fused rings such as 1,4-benzothiazine, 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydroquinoxaline, indoline, and 1,5-benzoxazepine. The 1,4-benzothiazine derivative displayed approximately 20 times more potent vasorelaxant activity than cromakalim.

A novel target recognition revealed by calmodulin in complex with Ca2+-calmodulin-dependent kinase kinase.

The structure of calcium-bound calmodulin (Ca2+/CaM) complexed with a 26-residue peptide, corresponding to the CaM-binding domain of rat Ca2+/CaM-dependent protein kinase kinase (CaMKK), has been determined by NMR spectroscopy. In this complex, the CaMKK peptide forms a fold comprising an alpha-helix and a hairpin-like loop whose C-terminus folds back on itself. The binding orientation of this CaMKK peptide by the two CaM domains is opposite to that observed in all other CaM-target complexes determined so far.

Novel potassium channel activators. II. Synthesis and pharmacological evaluation of 3,4-dihydro-2H-1,4-benzoxazine derivatives: modification of the aromatic part.

Three new series of analogues related to 3,4-dihydro-2H-1,4-benzoxazine derivative 1a were synthesized and evaluated for their potassium channel activating activity. In the first series I, where the 6,7-positions were disubstituted, it was found that an electron-withdrawing substituent was preferable at the 6 position, but either an electron-withdrawing or releasing substituent without bulkiness was tolerated at the 7 position. In the second series II, where several heterocycles were introduced into the 6,7-positions, the oxadiazole derivative 6 showed more potent activity than cromakalim.

Synthesis and biological evaluation of 1,2,3,4-tetrahydroisoquinoline derivatives as potent and selective M2 muscarinic receptor antagonists.

A series of 1,2,3,4-tetrahydroisoquinoline derivatives containing the 5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one skeleton were prepared and evaluated for their in vitro binding affinities to muscarinic receptors and for antagonism of bradycardia in vivo. Among them, compound 3f had the highest affinity for M2 muscarinic receptors in the heart (pKi = 9.1) with low affinity for M3 muscarinic receptors in the submandibular gland.

Peptide based interleukin-1 beta converting enzyme (ICE) inhibitors: synthesis, structure activity relationships and crystallographic study of the ICE-inhibitor complex.

Based on the X-ray structure of the complex of Ac-Tyr-Val-Ala-Asp-H (L-709049) and interleukin-1 beta converting enzyme (ICE), we synthesized compounds which were derived from 2-NapCO-Val-Pro-Asp-CH2OPh (1) to obtain a potent inhibitor in the cell assay. Among these compounds, (3S)-N-methanesulfonyl-3-[[1-[N-(2-naphthoyl)-L-valyl]-L-prolyl]amino]- 4-oxobutanamide (27c) showed high potency not only in the enzyme assay but also cell assay with IC50 values of 38 nM and 0.23 microM, respectively.

Evidence for calmodulin inter-domain compaction in solution induced by W-7 binding.

Small-angle X-ray scattering and nuclear magnetic resonance were used to investigate the structural change of calcium-bound calmodulin (Ca2+/CaM) in solution upon binding to its antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7). The radius of gyration was 17.4+/-0.

Synthesis and NK1 receptor antagonistic activity of (+/-)-1-acyl-3-(3,4- dichlorophenyl)-3-[2-(spiro-substituted piperidin-1'-yl)ethyl]piperidines.

(+/-)-1-Acyl-3-(3,4-dichlorophenyl)-3-[2-(spiro-substituted piperidin-1'-yl)ethyl]piperidines and their quaternary ammonium salts were prepared and evaluated for their NK1 receptor antagonistic activity. Some of these inhibited SP-induced contraction in guinea pig ileum with IC50 values at a level of 10(-9) M and showed potent inhibitory activity against selective NK1 receptor agonist-induced bronchoconstriction in guinea pigs.

Spiro-substituted piperidines as neurokinin receptor antagonists. III. Synthesis of (+/-)-N-[2-(3,4-dichlorophenyl)-4-(spiro-substituted piperidin-1'-yl)butyl]-N-methylbenzamides and evaluation of NK1-NK2 dual antagonistic activities.

To discover a novel NK1-NK2 dual antagonist, we have synthesized a series of spiro-substituted piperidines utilizing YM-35375 as a lead compound, and evaluated affinities for NK1 and NK2 receptors. In the N-methylbenzamide moiety, introduction of methoxy groups increased affinity for the NK1 receptor without a significant loss of affinity for the NK2 receptor. We also found that a conformation in which the phenyl groups of the N-methylbenzamide and 3,4-dichlorophenyl moieties are close to each other through a cis-amide bond, may be favorable for showing high affinity for the NK1 receptor and that a hydrogen bond-accepting group in the spiro-substituted piperidine moiety may be crucial for exhibiting high affinity for the NK2 receptor.

Selective muscarinic antagonists. II. Synthesis and antimuscarinic properties of biphenylylcarbamate derivatives.

A novel series of biphenylylcarbamate derivatives were synthesized and evaluated for binding to M1, M2 and M3 receptors and for antimuscarinic activities. Receptor binding assays indicated that biphenyl-2-ylcarbamate derivatives had high affinities for M1 and M3 receptors and good selectivities for M3 receptor over M2 receptor, indicating that the biphenyl-2-yl group is a novel hydrophobic replacement for the benzhydryl group in the muscarinic antagonist field. In this series, quinuclidin-4-yl biphenyl-2-ylcarbamate monohydrochloride (8l, YM-46303) exhibited the highest affinities for M1 and M3 receptors, and selectivity for M3 over M2 receptor.

Selective muscarinic antagonists. I. Synthesis and antimuscarinic properties of 4-piperidyl benzhydrylcarbamate derivatives.

A series of 1-substituted-4-piperidyl benzhydrylcarbamate derivatives were synthesized and evaluated for binding affinity to M1, M2 and M3 receptors, and for antimuscarinic activities. Receptor binding assays indicated that 1-benzyl-4-piperidyl benzhydrylcarbamate derivatives showed higher affinities for M1 and M3 receptors, and good selectivities for M3 over M2 receptor, than the corresponding ester analog. These results indicate that the urethane bond is a novel linker for muscarinic antagonists, and serves to lock the molecular conformation and allows the hydrophobic portion and cationic site of the molecule to bind to M1 and M3 muscarinic receptors.

Spiro-substituted piperidines as neurokinin receptor antagonists. I. Design and synthesis of (+/-)-N-[2-(3,4-dichlorophenyl)-4-(spiro [isobenzofuran-1(3H),4'piperidin]-1'-yl)butyl]-N-methylbenzamide, YM-35375, as a new lead compound for novel neurokinin receptor antagonists.

Analysis of the structural requirements of compound 1 (SR48968), a potent NK2 receptor antagonist, revealed that the 4-phenyl group of the piperidine is essential for binding with the NK2 receptor and occupies an equatorial position. Energy calculation of a variety of substituted 4-phenyl piperidines revealed that spiro[isobenzofuran-1(3H),4'-piperidine] possesses a conformationally restricted equatorial phenyl group. Our compound 12 (YM-35375) possessing this spiro-substituted piperidine bound to the NK2 receptor with an IC50 value of 84 nM and to the NK1 receptor with an IC50 value of 710 nM.

Spiro-substituted piperidines as neurokinin receptor antagonists. II. Syntheses and NK2 receptor-antagonistic activities of N-[2-aryl-4-(spiro-substituted piperidin-1'-yl)butyl]carboxamides.

In the course of our research on spiro-compounds as neurokinin receptor antagonists, N-[2-aryl-4-(spiro-substituted piperidin-1'-yl)butyl]carboxamides were designed, based on YM-35375 (3) as a lead compound, and evaluated for NK2 receptor-antagonistic activities. Some derivatives inhibited the binding of radio-labeled neurokinin A to the NK2 receptor with IC50 values at the level of 10(-9) M. Among these compounds, (+/-)-1'-[4-(N-benzoyl-N-methylamino)-3- (3,4-dichlorophenyl)butyl]spiro[benzo[c]thiophene-1(3H), 4'-piperidine] 2-oxide (58, YM-38336) showed 10 times more potent NK2 receptor binding affinity than compound 3 (IC50 values of 8.

Studies on beta-lactam antibiotics. II. Synthesis and antibacterial activity of cephalosporins with substituted 1,3-dithietane directly attached to the C-3 position.

Preparation of cephalosporins bearing a 1,3-dithietane ring attached to the C-3 position using intramolecular rearrangement are described. The diastereoisomers (6a-I and 6a-II) were separated by silica gel column chromatography. These 3-[4-(carbamoyl carboxymethylene)-1,3-dithietane-2-yl]cephems showed comparable activity against Gram-negative bacteria to that of ceftazidime.

Studies on beta-lactam antibiotics. I. Synthesis and in vitro anti-pseudomonal activity of 3-isothiazole-cephalosporin derivatives.

The synthesis and in vitro activity of 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-(2-carboxy-2- alkoxyimino)acetamido]cephalosporins with a (4-carboxy-3-hydroxy-5-isothiazolyl)thiomethyl group at the 3-position are described. These cephalosporins (9a approximately 9i) showed excellent activity against Gram-negative bacteria including beta-lactamase producing strains. The most interesting compound of the series was 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2- (2-carboxy-2-propoxyimino)acetamido]-3-cephem-4-carboxylic acid (9g, YM-13115) because of its outstanding inhibitory potency against Pseudomonas aeruginosa and highly prolonged plasma half-life in rats.