Optimization and validation of a high-performance liquid chromatographic method with UV detection for the determination of pyrrole-imidazole polyamides in rat plasma

A simple and sensitive high-performance liquid chromatography (HPLC) method utilizing UV detection was developed for the determination of plasma pyrrole (Py)-imidazole (Im) polyamides in rats and applied to the pharmacokinetic study of compounds. After deproteinization of plasma with methanol, Py-Im polyamides were analyzed with a reversed-phase TSK-GEL ODS-80TM (4.6 mmx15.0 cm TOSOH Co., Japan) column maintained at 40 degrees C. The mobile phase solvent A was 0.1% acetic acid and the solvent B was HPLC-grade acetonitrile (0-10 min, A: 100-20%, B: 0-80% linear gradient; 10-15 min, A: 40%, B: 60%). The flow rate was 1.0 ml/min. The detection wavelength was set at 310 nm. The method was used to determine the plasma concentration time profiles of Py-Im polyamides after intravenous injection.     

Synthesis of closo-Dodecaboryl Lipids and their Liposomal Formation for Boron Neutron Capture Therapy

High accumulation and selective delivery of boron into tumor tissues are the most important requirements to achieve efficient neutron capture therapy of cancers. We focused on liposomal boron delivery system to achieve a large amount of boron delivery to tumor. We succeeded in the synthesis of the double-tailed boron cluster lipids 4a–c and 5a–c, which has a B₁₂H₁₁S-moiety as a hydrophilic function, by S-alkylation of B₁₂H₁₁SH with bromoacetyl and chloroacetocarbamate derivatives of diacylglycerols. Size distribution of liposomes prepared from the boron cluster lipid 4b, dimyristoylphosphatidylcholine, polyethyleneglycol-conjugated distearoylphosphatidylethanolamine, and cholesterol was determined as 100 nm in diameter by an electrophoretic light scattering spectrophotometer. Calcein-encapsulation experiments revealed that these boronated liposomes are stable at 37 °C in fetal bovine serum solution for 24 h.     

Biochemical characterization of photosystem I complexes having different subunit compositions of fucoxanthin chlorophyll a/c-binding proteins in the diatom Chaetoceros gracilis

Photosynthesis Research - Diatoms are dominant phytoplankton in aquatic environments and have unique light-harvesting apparatus, fucoxanthin chlorophyll a/c-binding protein (FCP). Diatom...     

Transcriptome analysis of soybean (Glycine max) root genes differentially expressed in rhizobial,arbuscular mycorrhizal,and dual symbiosis

Journal of Plant Research - Soybean (Glycine max) roots establish associations with nodule-inducing rhizobia and arbuscular mycorrhizal (AM) fungi. Both rhizobia and AM fungi have been shown to...     

Sex Allocation by a Parasitoid Wasp (Hymenoptera: Ichneumonidae) to Different Host Species: A Question for the Mechanism of Host Size Estimation

Sex allocation by the polyphagous solitary pupal parasitoid wasp Pimpla luctuosa Smith to a small host species, Galleria mellonella (L.), and a large host species, Mamestra brassicae L., was investigated to test whether female wasps responded to hosts of different sizes across different host species. In the experiments, both host species were presented to each test female wasp. Primary and secondary sex ratio experiments revealed that female wasps laid more female eggs in larger pupae of each host species, indicating that female wasps recognized size differences within host species. The wasp sex ratio (male ratio) from M. brassicae, however, was much higher than that expected on the basis of the sex ratio curve from different-sized G. mellonella. Larger hosts of each host species yielded larger wasps, indicating that the host size estimation by female wasps across different host species was incomplete or was not simple. These results suggested that P. luctuosa evaluated host size not only by physical measures such as dimension but also by other unknown measures. A possible explanation for the adaptiveness of different sex ratio responses by Pimpla luctuosa to different host species was discussed.     

Synthesis of antisense oligonucleotides carrying modified 2-5A molecules at their 5'-termini and their properties

The synthesis of 8-methyladenosine-substituted 2-5A tetramers with hydroxyalkyl groups at the 5'-phosphates and the corresponding 2-5A-antisense chimeras is described. These oligonucleotides were synthesized by the phosphoramidite method with a DNA/RNA synthesizer. These 2-5A tetramers with hydroxyethyl and hydroxybutyl groups at their 5'-phosphates were more resistant to hydrolysis by alkaline phosphatase than those without the hydroxyalkyl groups. Incorporation of the hydroxyethyl group into the 2-5A tetramer and 2-5A-antisense chimera slightly reduced the abilities of their analogues to activate recombinant human RNase L, but the abilities of the 2-5A tetramer and the 2-5A-antisense chimera both with the hydroxyethyl group and 8-methyladenosine returned to 80 and 50% relative to those of the oligonucleotides without the hydroxyethyl group and 8-methyladenosine, respectively. Furthermore, the enzyme activated by 8-methyladenosine-substituted 2-5A-antisense chimera with the hydroxyethyl group cleaved the complementary RNA as efficiently as that activated by 2-5A-antisense chimera without the hydroxyethyl group and 8-methyladenosine. Thus, the 2-5A-antisense chimera carrying the hydroxyethyl group and 8-methyladenosine will be a candidate for a novel antisense molecule.     

Induction of cytochrome P450 1A is required for circulation failure and edema by 2,3,7,8-tetrachlorodibenzo-p-dioxin in zebrafish

The mechanism of toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is thought to result from changes in gene expression via the aryl hydrocarbon receptor (AHR). The induction of cytochrome P450 1A (CYP1A) in various organs is a cardinal effect of TCDD. However, whether CYP1A is involved in endpoints of TCDD toxicity is controversial. We investigated the role of CYP1A in TCDD-induced developmental toxicities using gene knock-down with morpholino antisense oligos. Exposure of zebrafish embryos to TCDD, at concentrations eliciting the hallmark endpoints of developmental toxicity, induced CYP1A in the heart and vascular endothelium throughout the body. This induction by TCDD was markedly inhibited by morpholinos to zebrafish arylhydrocarbon receptor 2 (zfAHR2-MO) and to zebrafish CYP1A (zfCYP1A-MO). The zfAHR2-MO but not the zfCYP1A-MO inhibited zfCYP1A mRNA expression, indicating the specificities of these morpholinos. Injection of either zfAHR2-MO or zfCYP1A-MO blocked the representative signs of TCDD developmental toxicity in zebrafish, pericardial edema and trunk circulation failure. The morpholinos appeared do not affect normal development in TCDD-untreated embryos. These results suggest a mediatory role of zfCYP1A induction through zfAHR2 activation in causing circulation failure by TCDD in zebrafish. This is the first molecular evidence demonstrating an essential requirement for CYP1A induction in TCDD-evoked developmental toxicities in any vertebrate species.     

A role of H+ flux in active Ca2+ transport into sarcoplasmic reticulum vesicles. II. H+ ejection during Ca2+ uptake

Proton efflux during Ca2+ transport into sarcoplasmic reticulum vesicles was examined. Although a rapid H+ ejection was observed during the initial phase of Ca2+ uptake and the amount of the liberated H+ was more than that due to hydrolysis of ATP, generation of a pH difference as a result of the H+ efflux could not be detected by direct pH measurement with a pH meter. Alkalinization of the inside of the vesicles during Ca2+ uptake was more precisely examined by flow dialysis assay and a significant uptake of acetate or salicylate into the vesicles was found, suggesting the generation of a small pH difference across the SR membrane. From these results, it was concluded that counter-transport of H+ was operative in Ca2+ uptake but that only a relatively small pH difference was generated as a result of the H+ efflux. The intrinsic buffering capacity of sarcoplasmic reticulum vesicles was measured and a relatively large value (130 nmol H+/pH unit/mg at pH 6.2) was obtained.