Improved bactericidal activity of silver-loaded zirconium phosphate in the presence of Cl− by combining with hydroxyapatite

Silver-loaded zirconium phosphate (AgZ) was combined with hydroxyapatite (HA) to prepare an antibacterial composite (AgZ/HA) with improved activity in the presence of Cl^–. When Escherichia coli cells were deactivated in 154 mM NaCl, the bacterial survival ratio at 90 min for AgZ/HA was 3.9×10^–4 compared to 1.2×10^–1 for AgZ itself. Because the bactericidal activity of AgZ/HA decreased with increasing phosphate ion up to 10 mM, cell adsorption onto the combined HA moiety probably compensated for the Cl^–-induced deterioration in the activity of the silver-based bactericide.     

Arabidopsis TOBAMOVIRUS MULTIPLICATION (TOM) 2 locus encodes a transmembrane protein that interacts with TOM1

The tom2-1 mutation of Arabidopsis thaliana reduces the efficiency of intracellular multiplication of tobamoviruses. The tom2-1 mutant was derived from fast-neutron-irradiated seeds, and the original mutant line also carries ttm1, a dominant modifier that increases tobamovirus multiplication efficiency in a tobamovirus-strain-specific manner in the tom2-1 genetic background. Here, we show that the tom2-1 mutation involved a deletion of approximately 20 kb in the nuclear genome. The deleted region included two genes named TOM2A and TOM2B that were both associated with the tom2-1 phenotype, whereas ttm1 corresponded to the translocation of part of the deleted region that included intact TOM2B but not TOM2A. TOM2A encodes a 280 amino acid putative four-pass transmembrane protein with a C-terminal farnesylation signal, while TOM2B encodes a 122 amino acid basic protein. The split-ubiquitin assay demonstrated an interaction of TOM2A both with itself and with TOM1, an integral membrane protein of A.thaliana presumed to be an essential constituent of tobamovirus replication complex. The data presented here suggest that TOM2A is also an integral part of the tobamovirus replication complex.     

Production of lupin acid phosphatase in transgenic rice for use as a phytate-hydrolyzing enzyme in animal feed

The acid phosphatase gene from lupin was expressed in transgenic rice plants under the control of the maize ubiquitin promoter or rice chlorophyll a/b binding protein (Cab) promoter. Transgenic rice leaves exhibited up to an 18-fold increase in phytate-hydrolyzing activity. Based on the phytate-hydrolyzing activity at pH 5.5, more than 85% this activity was retained after heat-treatment at 80 degrees C for 15 min, and the heterologous enzyme in leaf sections and leaf extracts was relatively stable during storage. A distinct increase in released phosphate was observed when the heterologous enzyme was mixed with the feed extract. These results suggest that the heterologous enzyme in rice plants may maintain its desired characteristics as a phytate-hydrolyzing enzyme when added to animal feed.     

Characterization of C1-metabolizing prokaryotic communities in methane seep habitats at the Kuroshima Knoll, southern Ryukyu Arc, by analyzing pmoA, mmoX, mxaF, mcrA, and 16S rRNA genes

Samples from three submerged sites (MC, a core obtained in the methane seep area; MR, a reference core obtained at a distance from the methane seep; and HC, a gas-bubbling carbonate sample) at the Kuroshima Knoll in the southern Ryuku arc were analyzed to gain insight into the organisms present and the processes involved in this oxic-anoxic methane seep environment. 16S rRNA gene analyses by quantitative real-time PCR and clone library sequencing revealed that the MC core sediments contained abundant archaea (approximately 34% of the total prokaryotes), including both mesophilic methanogens related to the genus Methanolobus and ANME-2 members of the Methanosarcinales, as well as members of the delta-Proteobacteria, suggesting that both anaerobic methane oxidation and methanogenesis occurred at this site. In addition, several functional genes connected with methane metabolism were analyzed by quantitative competitive-PCR, including the genes encoding particulate methane monooxygenase (pmoA), soluble methane monooxygenase (mmoX), methanol dehydrogenese (mxaF), and methyl coenzyme M reductase (mcrA). In the MC core sediments, the most abundant gene was mcrA (2.5 x 10(6) copies/g [wet weight]), while the pmoA gene of the type I methanotrophs (5.9 x 10(6) copies/g [wet weight]) was most abundant at the surface of the MC core. These results indicate that there is a very complex environment in which methane production, anaerobic methane oxidation, and aerobic methane oxidation all occur in close proximity. The HC carbonate site was rich in gamma-Proteobacteria and had a high copy number of mxaF (7.1 x 10(6) copies/g [wet weight]) and a much lower copy number of the pmoA gene (3.2 x 10(2) copies/g [wet weight]). The mmoX gene was never detected. In contrast, the reference core contained familiar sequences of marine sedimentary archaeal and bacterial groups but not groups specific to C1 metabolism. Geochemical characterization of the amounts and isotopic composition of pore water methane and sulfate strongly supported the notion that in this zone both aerobic methane oxidation and anaerobic methane oxidation, as well as methanogenesis, occur.     

Atypical properties of several classes of antipsychotic drugs on the basis of differential induction of Fos-like immunoreactivity in the rat brain

Acute administration of typical and atypical antipsychotics has been reported to induce regionally distinct patterns of c-Fos expression in the rat forebrain. Furthermore, atypical index, the difference in the extent of increased Fos-like immunoreactivity (Fos-LI) in the nucleus accumbens (NAc) shell versus the dorsolateral striatum (DLSt), has been proposed to classify antipsychotics into typical or atypical antipsychotics. The present study was conducted to investigate the atypical properties of 24 antipsychotics that are used in Japan and blonanserin, a novel 5-HT2A and D2 receptor antagonist. We systematically examined the effects of the drugs on Fos-LI in the NAc and DLSt in the rat brain using immunohistochemistry and calculated the atypical index, comparing with those of haloperidol and clozapine. Floropipamide, oxypertine, nemonapride, pimozide and mosapramine, as well as clozapine, olanzapine, quetiapine and risperidone, showed high positive atypical index. Zotepine, perospirone, sulpiride, moperone, sultopride, thioridazine, carpipramine, clocapramine and blonanserin showed moderate ones. In contrast, fluphenazine, bromperidol, timiperone, spiperone, propericiazine, perphenazine, chlorpromazine and levomepromazine had negative atypical index like haloperidol. These results suggest that not only so-called atypical antipsychotics, but also several conventional drugs, possess atypical properties.     

Saccharomyces cerevisiae Mer3 is a DNA helicase involved in meiotic crossing over

Crossing over is regulated to occur at least once per each pair of homologous chromosomes during meiotic prophase to ensure proper segregation of chromosomes at the first meiotic division. In a mer3 deletion mutant of Saccharomyces cerevisiae, crossing over is decreased, and the distribution of the crossovers that occur is random. The predicted Mer3 protein contains seven motifs characteristic of the DExH box type of DNA/RNA helicases. The mer3G166D and the mer3K167A mutation, amino acid substitutions of conserved residues in a putative nucleotide-binding domain of the helicase motifs caused a defect in the transition of meiosis-specific double-strand breaks to later intermediates, decreased crossing over, and reduced crossover interference. The purified Mer3 protein was found to have DNA helicase activity. This helicase activity was reduced by the mer3GD mutation to <1% of the wild-type activity, even though binding of the mutant protein to single- and double-strand DNA was unaffected. The mer3KA mutation eliminated the ATPase activity of the wild-type protein. These results demonstrate that Mer3 is a DNA helicase that functions in meiotic crossing over.     

Transforming growth factor-beta isoforms differently stimulate proalpha2 (I) collagen gene expression during wound healing process in transgenic mice

The role of many growth factors and cytokines in the process of wound healing has been intensively investigated in recent two decades. Among them, transforming growth factor-betas (TGF-betas) are well known to have a potent stimulatory effect on collagen synthesis as shown in various in vivo experimental systems. In the present study, we examined the effects of various growth factors on the promoter activity of the proalpha2 (I) collagen gene (COL1A2) during the wound healing process. For this purpose, we utilized transgenic mice harboring the -17 kb promoter sequence of the mouse COL1A2 linked to either a firefly luciferase or a bacterial beta-galactosidase gene. These mice exhibited normal phenotypic expression and the wound healing process was not impaired. Full thickness wounds were made by punch biopsy. We examined the effects of TGF-beta1, -beta2, -beta3, basic fibroblast growth factor, platelet-derived growth factor, and connective tissue growth factor by applying them locally to the open wound every 2 days. Among the growth factors examined, all of the three isoforms of TGF- exhibited a more potent stimulatory effect on COL1A2 promoter activity than did other factors. In addition, while TGF-beta1 and -beta2 significantly increased the number of fibroblasts which were positive for X-Gal staining, TGF-beta3 treatment did not change the number of beta-galactosidase expressing cells. Accumulation of collagen fibers was observed to the same extent in the mice treated with TGF-beta1 and those with TGF-beta3. These findings suggest that TGF-beta1 and -beta3 have similar but not identical regulatory mechanisms of COL1A2 expression, and that their pathophysiological roles in wound healing might be different from each other.     

An accessory role for ceramide in interleukin-1β induced prostaglandin synthesis

Interleukin-1 (IL-1) is a potent inducer of prostaglandin E₂ (PGE₂) synthesis. We previously showed that ceramide accumulates in fibroblasts treated with IL-1 and that it enhances IL-1-induced PGE₂ production. The present study was undertaken to determine the mechanism(s) by which ceramide and IL-1 interact to enhance PGE₂ production by examining their respective effects on the rate-limiting enzymes in PGE₂ synthesis, cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and cytosolic phospholipase A₂ (cPLA₂). IL-1-induced PGE₂ synthesis required 8 h even though COX-1 was constitutively expressed (both mRNA and protein) and enzymatically active in untreated cells. Conversely, COX-2 mRNA was barely detectable in untreated cells but within 2 h, ceramide or IL-1 alone induced a 5 and 20 fold increase in COX-2 mRNA, respectively. However, IL-1 induced COX-2 protein synthesis was only detectable 6-7 h after maximal COX-2 mRNA induction; COX-2 protein accumulation was not induced by ceramide alone. Ceramide however, reduced the length of time required for IL- 1 to induce COX-2 protein accumulation and increased COX-2 protein accumulation. IL-1 induced a 15 fold increase in COX-1 mRNA including an alternatively spliced form of COX-1. IL-1, but not ceramide induced cPLA₂ mRNA and protein expression which corresponded with the initiation of PGE₂ synthesis. These observations indicate that, (1) while either ceramide or IL-1 rapidly induced COX-2 mRNA, COX-2 protein only accumulated in IL- 1 treated cells after a delay of 6-7 h, (2) IL-1-induced PGE₂ synthesis required both COX-2 and cPLA₂ protein synthesis and, (3) ceramide enhanced (temporally and quantitatively) IL-1-induced COX-2 protein accumulation resulting in enhanced PGE₂ production.     

Japanese juvenile retinoschisis is caused by mutations of the XLRS1 gene

We investigated the XLRS1 gene in Japanese patients with retinoschisis (RS). All exons of the XLRS1 gene were sequenced in 14 males, including a pair of monozygotic twins, from 11 individual families with RS and five of their mothers who are asymptomatic but diagnosed as carriers. Six kinds of missense mutations and a nonsense mutation, including six novel mutations, were detected in all 14 patients and carriers. Mutations in the XLRS1 gene are also responsible for RS in non-Caucasian patients. Most Japanese RS cases are caused by an XLRS1 gene defect. A novel mutation, Glu72Lys, was found in four families, suggesting a common mutation in the Japanese population. Clinical features of RS patients with both the Glu72Lys and Pro193Leu mutations indicate that a genotype–phenotype correlation is not recognized in RS. Received: 12 January 1998 / Accepted: 21 March 1998     

Effect of ozone on photosystem II of tobacco chloroplasts in the presence of piperonyl butoxide

Inhibitors of photosynthetic electron flow and electron donorsfor photosystem II effectively protected tobacco leaves againstozone injury, suggesting that this photosystem is closely linkedwith the development of ozone injury. Hill reaction activityof the chloroplasts isolated from tobacco leaves immediatelyafter ozone fumigation was significantly lower than that ofthe chloroplasts isolated from non-fumigated leaves. This ozone-induceddecrease in Hill reaction activity was partially prevented whenthe leaves were pretreated with piperonyl butoxide (PB), whichis highly effective against ozone injury. Ozone bubbling into the isolated chloroplast suspension markedlydecreased the rate of DPIP photoreduction. PB reduced this decreaseabout 50%. PB also prevented the ozone-induced decrease of chlorophylland carotenoids. ¹Present address: The Central Research Institute, Japan Tobacco& Salt Public Corporation, Umegaoka, Midori-ku, Yokohama227, Japan (Received June 14, 1976; )