Identification and quantitative analysis of degradation products of chlorhexidine with chlorhexidine-resistant bacteria with three-dimensional high performance liquid chromatography

The products of the degradation of chlorhexidine by two chlorhexidine-resistant strains of Achromobacter xylosoxidans , isolated from an ultrasonic hand washer, were identified by three-dimensional HPLC. In the degradation process a pathway forming p -chlorophenol, probably through p -chloroaniline, was also observed, as was a pathway forming phenol and pyrogallol. The quantitative measurement of these products at their maximum absorption spectra by two-dimensional HPLC suggested the presence of chlorhexidine-degrading enzymes.     

Participation of superoxide, hydrogen peroxide and hydroxyl radicals in NADPH-cytochrome P-450 reductase-catalyzed peroxidation of methyl linolenate.

1. NADPH-cytochrome P-450 reductase-catalyzed peroxidation of methyl linolenate is inhibited by superoxide dismutase, catalase, ethanol, and mannitol, and is potentiated by H2O2. 2. H2O2 is shown to be generated in the incubation mixture in the presence of NADPH and NADPH-cytochrome P-450 reductase. If the system contains Fe-EDTA complex, H2O2 is not formed. In the presence of the enzyme and Fe-EDTA complex, added H2O2 is consumed. 3. In the presence of Fe-EDTA complex, NADPH-cytochrome P-450 reductase is shown to generate O-2 at a slow rate. These results suggest that H2O2 produced from O-2 is decomposed to form OH . by the action of Fe-EDTA complex in the lipid peroxidation system, and that OH . is a trigger of lipid peroxidation.     

The Chelating Ability of Adenosine-5′-Triphosphate-3′-Diphosphate (pppApp)

We have developed a new series of R4L1 Gateway binary vectors (R4L1pGWB), which carry the bialaphos resistance gene (bar) or the UDP-N-acetylglucosamine:dolichol phosphate N-acetylglucosamine-1-P transferase (GPT) gene as selection markers that confer BASTA^® and tunicamycin resistance on plants respectively. R4L1pGWBs have an attR4-attL1-reporter and can accept an attL4-promoter-attR1 entry clone for easy construction of an attB4-promoter-attB1-reporter clone. The new R4L1pGWBs facilitate promoter:reporter analysis in pre-existing transgenic plants that are resistant to kanamycin or hygromycin.     

Formation of the Recombinant between Ampicillin Re istance Determinant and Transfer Factor

In vitro-developed resistant mutants were obtained by inoculating a clinical isolate of Aerobacter cloacae on plates containing various concentrations of ampicillin (APC). This resistance was paralleled by an increase in the formation of β-lactamase. When A. cloacae carrying the nontransmissible APC resistance-determinant (amp) was infected with a T-tet factor, a recombinant T-tet.amp factor was formed; the recombinant being conjugally transmissible and capable of conferring APC resistance on their host. This fact implies the origin of the R factor; the R factor being formed by the recombination of sex factors with nontransmissible drug resistance-determinants.     

Vimentin Expression Pattern is Different between the Flank Region and Limb Regions of Somatopleural Mesoderm in the Chicken Embryo

It is known that the chicken flank somatopleure also has a limb-forming potential at early stages of development, but loses this potential later. Molecular changes during this process is, however, not well known. We obtained a monoclonal antibody which reacts to the flank somatopleure, but not to the wing bud, the leg bud and the neck somatopleure in the stage 22 chicken embryo. Further study revealed that this antibody is specific to vimentin. Time course of vimentin expression in the somatopleural mesoderm during the development was studied. It was revealed to be biphasic. Somatopleural mesoderm expressed vimentin at stage 10, but not at stage 16. Flank somatopleural mesoderm began to express vimentin again at stage 18, whereas limb bud mesenchymal cells did not until stage 27. The earlier re-expression of vimentin at the flank somatopleure suggests that certain physiological changes take place in cells at this region.     

Thec-kit receptor transduces the stem cell factor-triggered growth signal in murine interleukin-3-dependent cell line

The stem cell factor is a glycoprotein hormone which regulates the proliferation and differentiation of primitive hematopoietic cells through its interaction with a tyrosine kinase transmembrane receptor which is encoded by thec-kit proto-oncogene. To examine whether a murinec-kit receptor can be functional in murine interleukin-3 (mlL-3)-dependent hematopoietic cell line, we introduced the murinec-kit cDNA into mlL-3-dependent pro-B cell line Ba/F3. One of the resulting clones, Ba/F3 clone BF-K96, expressed the 140 kDa protein recognized by anti-c-kit monoclonal antibody and the expressedc-kit receptor protein on the cell surface bound to a radiolabeled soluble form of murine stem cell factor (mSCF) with high affinity. BF-K96 clone expressing thec-kit receptor could proliferate in response to mSCF in the absence of mlL-3. The cell clone could also grow in co-culture with mouse 3T3 cells which are endogeneously expressing a membrane-associated type of mSCF on their cell surfaces. These findings demonstrate that thec-kit receptor expressed on mlL-3-dependent hematopoietic cell line Ba/F3 transduce the mSCF-dependent growth signal, indicating that established cell clone will provide a unique cellular system for the study of SCF/c-kit signal transduction mechanism.Abbreviations SCF stem cell factor - IL interleukin - CSF colony stimulating factor - IMDM Iscove's Modified Dulbecco's Medium - DME Dulbecco's Modified Eagle's Medium - FCS fetal calf serum - PCR polymerase chain reaction - EDTA ethylenediaminetetra-acetic acid; sodium dodecyl sulfate     

Update on the possible mode of action of the jasmonates: Focus on the metabolism of cell wall polysaccharides in relation to growth and development

Jasmonic acid (JA) and its related compounds (jasmonates) applied to plant tissues exert either inhibitory or promotive effects in growth and developmental processes, which in some ways are similar to abscisic acid. However, little is known about the mode of action of the jamonates at the tissue or organ levels. Here, we review partial evidence for the physiological action of the jasmonates on cell elongation and abscission.
Jasmonates inhibit the IAA-induced cell elongation of oat coleoptile segments not by affecting energy production, osmoregulation and cell wall loosening, but by inhibiting the synthesis of cell wall polysaccharides. The inhibition is partially reversed by simultaneous application of sucrose. Inhibition of IAA-induced elongation by JA is only observed in monocotyledons, not in dicotyledons. These effects suggest that jasmonates exert their inhibitory effect on cell elongation by affecting the metabolism of the cell wall polysaccharides in monocotyledons.
Jasmonates promote the abscission of bean petiole explants without enhancing ethylene production. Cells in the petiole adjacent to the abscission zone expand during abscission. In the abscission zone, jasmonates decrease the amount of cellulosic but not that of noncellulosic polysaccharides. Jasmonates increase the activities of cellulase and decrease the levels of UDP-sugars, which are important intermediates for the synthesis of cell wall polysaccharides in the abscission zone, probably resulting in the decreased level of cellulose and the mechanical weakness of cell walls.
Thus, it is suggested that jasmonates exert their multiple physiological effects by affecting the metabolic processes of cell wall polysaccharides.     

Two atypical ANGUSTIFOLIA without a plant-specific C-terminus regulate gametophore and sporophyte shapes in the moss Physcomitrium (Physcomitrella) patens

ANGUSTIFOLIA (AN) is a plant-specific subfamily of the CtBP/BARS/AN family, characterized by a plant-specific C-terminal domain of approximately 200 amino acids. Previously, we revealed that double knockout (DKO) lines of Physcomitrium (Physcomitrella) patens ANGUSTIFOLIA genes (PpAN1-1 and PpAN1-2) show defects in gametophore height and the lengths of the seta and foot region of sporophytes, by reduced cell elongation. In addition to two canonical ANs, the genome of P. patens has two atypical ANs without a coding region for a plant-specific C-terminus (PpAN2-1 and PpAN2-2); these were investigated in this study. Similar to PpAN1s, both promoters of the PpAN2 genes were highly active in the stems of haploid gametophores and in the middle-to-basal region of young diploid sporophytes that develop into the seta and foot. Analyses of PpAN2-1/2-2 DKO and PpAN quadruple knockout (QKO) lines implied that these four AN genes have partially redundant functions to regulate cell elongation in their expression regions. Transgenic strains harboring P. patens α-tubulin fused to green fluorescent protein, which were generated from a QKO line, showed that the orientation of the microtubules in the gametophore tips in the PpAN QKO lines was unchanged from the wild-type and PpAN1-1/1-2 DKO plants. In addition to both PpAN2-1 and PpAN2-2, short Arabidopsis AN without the C-terminus of 200 amino acids could rescue the Arabidopsis thaliana an-1 phenotypes, implying AN activity is dependent on the N-terminal regions.