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Non‐oxide materials such as oxynitrides are good candidates as photoanodes for visible‐light‐driven water oxidation, but most of them suffer from oxidative degradation by photogenerated holes, resulting in low stability. Herein we developed a photoanode using a visible‐light‐responsive TiO2 powder doped with tantalum and nitrogen (TiO2:Ta/N) for water oxidation. The Ta/N codoping enabled a stable anodic photocurrent response attributable to water oxidation under visible‐light irradiation. Surface modification of the TiO2:Ta/N anode with RuOx species further facilitated water oxidation catalysis, achieving stable O2 evolution over 5 h of operation with no sign of deactivation. Operando XAFS measurements revealed an important function of the RuOx species as a collector of photogenerated holes in TiO2:Ta/N, facilitating the photoelectrochemical water oxidation. Visible‐light‐driven H2 evolution and solar‐driven CO2 reduction into CO were both achieved by using water as an electron donor in photoelectrochemical cells with the TiO2:Ta/N photoanode coupled to a Pt cathode and a Ru(II)–Re(I) binuclear complex photocathode, respectively. Jack of all trades: A photoanode composed of TiO2 doped with tantalum and nitrogen worked for stable photoelectrochemical water oxidation coupled to hydrogen evolution and carbon dioxide reduction under visible and solar light. Operando XAFS measurements revealed a key function of RuOx species as a collector of photogenerated holes in TiO2:Ta/N, facilitating the photoelectrochemical water oxidation. [ABSTRACT FROM AUTHOR]

The Front Cover shows CO2 reduction and H2 production coupled to water oxidation by a photoelectrochemical system based on a Ta/N codoped rutile TiO2 anode under irradiation with sunlight. More information can be found in the Article by A. Nakada et al on page 37 in Issue 1, 2019 (DOI: 10.1002/cptc.201800157). [ABSTRACT FROM AUTHOR]

An automated chromatographic detection system for the simultaneous determination of riboflavin phosphate, caffeine, nicotinamide and pyridoxine hydrochloride in a multivitamin pharmaceutical preparation was constructed. Hydrolytic pretreatment of riboflavin phosphate to riboflavin was carried out using a pre-column enzyme reactor, in which immobilized sweet potato acid phosphatase was packed, and then enzymatically hydrolyzed riboflavin and other ingredients in the pharmaceutical preparation were concentrated in an ODS trap column. The concentrated riboflavin and other ingredients were back-eluted from the trap column using a mobile phase containing 1-decanesulfonate as an ion-pair reagent, and then subsequently chromatographed on an ODS analytical column. It was necessary to wash the ODS trap column with aqueous acetonitrile to remove 1-decanesulfonate in the trap column, which is advantageous to concentrate the riboflavin and other ingredients for the subsequent analysis. The calibration curves for riboflavin phosphate and other ingredients were linear over the concentration ranges tested, and correlation coefficients for standard curves were 0.9999 for all four ingredients. Analytical recoveries of the four ingredients at different levels of concentration added to the ordinary pharmaceutical preparation were also in the range of 99.1–101.2%. The present method was superior to the ordinary manual and batch-wise enzymatic methods in being harmless to the environment, rapid and accurate under continuous autoanalysis. [Copyright &y& Elsevier]

Homozygous Groggy dams, which carry a Cacna1a missense mutation, often show no interest in their offspring, leading to frequent offspring deaths due to lack of nurturing. The present study aimed to clarify whether the Cacna1a mutation contributes to impaired attachment behaviors between dam and offspring. The open field test showed that homozygous female rats exhibited markedly short travel distance, whereas no difference was found between the motor activity of heterozygous females and that of wild types (WT). A series of behavioral tests was performed to compare the mother-offspring relationship between WT and heterozygous rats. Performance in the pup retrieval test was significantly less successful in heterozygous than WT dams. During the experiment, heterozygous dams spent significantly less time licking and crouching than WT dams. The offspring dam-seeking behavior test revealed that heterozygous pups' vocalizations were significantly less frequent and shorter than those of WT pups. Although no significant difference was found between WT and heterozygous offspring in the olfactory sense test, using a piece of chocolate, heterozygous pups took significantly longer to reach a sample of the dam's bedding. Taken together, these findings suggest that the Cacna1a mutation impairs both the dam's maternal behavior and the offspring's attachment behavior toward the dam.

Histamine H1 receptor (H1R) levels vary under various pathological conditions, and these changes may be responsible for some pathogenesis such as in allergic rhinitis. Several stimulants, including histamine, muscarinic agonists and platelet-activating factor, have now been shown to regulate H1R levels and may have roles in regulating the H1R level in physiological and pathological conditions. Results for beta2-adrenoceptor (beta2AR) stimulation are conflicting, however.beta2AR up-regulated H1R in bovine tracheal smooth muscle, but down-regulated human H1R expressed in Chinese hamster ovary (CHO) cells. It is possible that this discrepancy comes from the differences in the preparations used for each study: the former cell expressed bovine H1R and the latter cell expressed human H1R. Moreover, CHO cells have been shown to be inadequate for studying the effects on H1R gene expression, because the cells express non-endogenous stably transfected H1R under the control of the SV40 promoter. Therefore, in this study, we have investigated the role of beta2AR stimulation in H1R gene regulation using human U373 astrocytoma cells that express endogenous H1R and transfected beta2AR. Stimulation of beta2AR significantly reduced H1R promoter activity and H1R mRNA levels. H1R mRNA stability was slightly reduced by beta2AR stimulation, although this was not significant. The decrease of H1R mRNA by beta2AR stimulation was blocked by the protein kinase A (PKA) inhibitor KT5720, suggesting the involvement of PKA. These results indicate that the beta2AR is involved in the down-regulation of human H1R by inhibiting H1R gene transcription through a PKA-dependent process.

Histamine is highly concentrated in the heart of animals and humans. Excessive release in pathophysiological conditions, such as immediate hypersensitivity and septic shock, causes cardiac dysfunction and arrhythmias. Previous pharmacological studies revealed that H(1) and H(2) receptors mediate these effects. Yet, an accurate estimate of the distribution and molecular characteristics of cardiac histamine receptors is missing. Recently, the genes encoding H(1) and H(2) receptors have been cloned, and the amino acid sequence and protein structure have been elucidated. Accordingly, we analyzed gene and protein expression levels of H(1) and H(2) receptors in atria and ventricles of guinea pig, rabbit, rat, and human hearts. With immunocytochemical techniques, we examined the regional expression of H(1) and H(2) receptor proteins in the sinoatrial and atrioventricular nodes and surrounding myocardium of the guinea pig heart. Northern and Western blot studies revealed that cardiac histamine H(1) and H(2) receptors are variably distributed among different mammalian species and different regions of the heart, whereas H(2) receptors are abundantly expressed in human atrial and ventricular myocardium. These findings agree with those of previous pharmacological studies, clearly demonstrating that the responses of the heart to histamine depend on the expression level of H(1) and H(2) receptors. The highly abundant expression of H(2) receptors in the human heart substantiates histamine arrhythmogenicity in various disease states. The new knowledge of a differential distribution of histamine receptor subtypes in the human heart will foster a better understanding of histamine roles in cardiovascular pathophysiology and may contribute to new therapeutic approaches to histamine-induced cardiac dysfunctions.

To clarify heterologous regulation of a receptor is important in considering medication. Histamine constricts the airway smooth muscle through the action to the H(1) receptor (H1R), which contributes to asthma. beta(2)-Adrenergic receptor (beta2R) agonists are widely used in asthmatic therapy for their bronchodilating effects. In this study, we investigated the effect of beta2R activation on the H1R function using Chinese hamster ovary cells stably co-expressing human histamine H1R and beta2R (CHO-H1/beta2 cell). The stimulation of beta2R resulted in the decrease of H1R in the membrane. Heterologous H1R down-regulation was significantly reversed in the presence of the cyclic AMP-dependent protein kinase (PKA) inhibitor KT5720. Since phosphorylation of G protein-coupled receptor (GPCR) by second messenger-dependent kinases, is proposed to be a key step initiating heterologous receptor desensitization, we examined whether heterologous H1R down-regulation was accompanied by H1R phosphorylation. H1R was phosphorylated by beta2R stimulation; however, a PKA inhibitor did not inhibit heterologous H1R phosphorylation. Our results suggest that H1R was heterologously regulated by beta2R. Not only a direct action of beta2R agonist to beta2R causing bronchodilation but also indirect action that reduces the number of H1R responsible for bronchoconstriction might contribute to a decrease in the bronchial resistance, which proposes another possible advantage of beta2R agonists for asthmatic medication.

Sweet potato acid phosphatase was covalently coupled with glutaraldehyde to aminopropyl controlled-pore glass, and used as a pre-column enzyme reactor. The immobilized enzyme reactor (IMER) was continuously operated using an automated chromatographic detection system we developed. Functional evaluation of the IMER was carried out by injecting ten samples on the same day at an injection amount of 1.25 nmol (62.5 nmol per ml) using riboflavin sodium phosphate (FMNs) as a substrate, and by prolonged use for ten months. The IMER exhibited decreased activity after repeated use for a total of 3000 samples, but about 75% of its original activity remained. The conversion rate of FMNs to riboflavin by IMER was increased from 89 to 97% by adding citrate, ethylenediaminetetraacetic acid disodium salt, etc., but especially by adding citrate. The increased conversion of FMNs to riboflavin due to the addition of citrate was probably not due to the chelation of heavy metal ions by citrate. We also investigated complex formation of acid phosphatase with the substrate FMNs using surface plasmon resonance to determine the effect of citrate on the processes of association and/or dissociation between the enzyme and substrate. Enzyme fatigue was also observed during the course of prolonged and repeated use.