Induction of apoptosis in MCF-7 cells by β-1,3-xylooligosaccharides prepared from Caulerpa lentillifera

β-1,3-Xylan was prepared from the green alga, Caulerpa lentillifera, and hydrolyzed to oligosaccharides by a mild acid treatment. The average degree of polymerization was about 5. The oligosaccharides reduced the number of viable human breast cancer MCF-7 cells in a dose-dependent manner, and induced chromatin condensation and degradation of poly ADP-ribose polymerase, indicating that they induced apoptosis in MCF-7 cells.     

Synergistic activation of NF-kappaB by nontypeable H. influenzae and S. pneumoniae is mediated by CK2, IKKbeta-IkappaBalpha, and p38 MAPK

In review of the past studies on NF-kappaB regulation, most of them have focused on investigating how NF-kappaB is activated by a single inducer at a time. Given the fact that, in mixed bacterial infections in vivo, multiple inflammation inducers, including both nontypeable Haemophilus influenzae (NTHi) and Streptococcus pneumoniae, are present simultaneously, a key issue that has yet to be addressed is whether NTHi and S. pneumoniae simultaneously activate NF-kappaB and the subsequent inflammatory response in a synergistic manner. Here, we show that NTHi and S. pneumoniae synergistically induce NF-kappaB-dependent inflammatory response via activation of multiple signaling pathways in vitro and in vivo. The classical IKKbeta-IkappaBalpha and p38 MAPK pathways are involved in synergistic activation of NF-kappaB via two distinct mechanisms, p65 nuclear translocation-dependent and -independent mechanisms. Moreover, casein kinase 2 (CK2) is involved in synergistic induction of NF-kappaB via a mechanism dependent on phosphorylation of p65 at both Ser536 and Ser276 sites. These studies bring new insights into the molecular mechanisms underlying the NF-kappaB-dependent inflammatory response in polymicrobial infections and may lead to development of novel therapeutic strategies for modulating inflammation in mixed infections for patients with otitis media and chronic obstructive pulmonary diseases.     

Role of 1-hydroxybenzotriazole in oxidation by laccase from Trametes versicolor. Kinetic analysis of the laccase-1-hydroxybenzotriazole couple

In the current studies, we used Lineweaver-Burke analysis to examine the role of 1-hydroxybenzotriazole (HBT) in the oxidation of various compounds by laccase from Trametes versicolor. At low concentrations, HBT was a competitive inhibitor of the oxidation, but at high concentrations, it was a noncompetitive inhibitor. Analysis of the oxidation of ferrocytochrome c by the laccase-HBT couple showed that increasing the concentration of ferrocytochrome c did not affect the V(max) but reduced the apparent K(m). In addition, in the manganese peroxidase-Mn(II) reaction, which is a typical oxidation system by mediator, the apparent K(m) and V(max) increased as the concentration of the substrate 2,6-dimethoxyphenol was increased. These results indicate that HBT is involved in the binding of laccase and substrates that laccase cannot oxidize alone.     

Reproductive success and distance to conspecific adults in the sparsely distributed tree Kalopanax pictus

To understand how a sparsely distributed species can maintain viable populations, and with a particular interest in distance-dependent reproductive success, we investigated the ovule survival and the factors that determine the survival for sparsely distributed Kalopanax pictus (Araliaceae) in a temperate forest landscape around the Ogawa Forest Reserve, central Japan. We found 154 potentially mature trees (>20 cm diameter at breast height) in a 600-ha site. The year 2000 was a mass flowering year for K. pictus; 96.8% of the trees examined flowered in that year; however, this was less than half of the trees that flowered in other years. The flowers of K. pictus include protandrous inflorescences, which bloom on individual tress in midsummer when few other tree species bloom. We conducted pollination experiments with out-crossed, self-pollinated, bagged, and control inflorescences. Results suggest that self-pollination is limited, partially by low self-compatibility and partially by protandry. Ovule survival from the flower to the seed stages was not dependent on the temporal flowering density of conspecific adults. The flowering habit and presence of effective pollinators may allow K. pictus to avoid the negative effects of sparse distribution on pollination efficiency. However, ovule survival during the ovary development stage depended on infection by a species-specific fungus, Mycosphaerella acanthopanacis. The fungus damages leaves, and the infection intensity depends on the distance between conspecific K. pictus adults. Thus, an advantage of sparse distribution in K. pictus is disease avoidance, whereas its disadvantages are overcome by pollination efficiency.     

Rapid enumeration of respiratory active mycobacteria with fluorescent double staining

A new method for rapid enumeration of physiologically active mycobacteria was developed by acid-fast bacilli staining (Auramine O) following formazan reduction. Results can be obtained within 90 min by the optimized procedure, while more than one week is required for the widely used culture-dependent approach.     

Cholesterol esterase accelerates intestinal cholesterol absorption

Lipid bilayers of dimyristoyl phosphatidylcholine (DMPC) containing opioid peptide dynorphin A(1-17) are found to be spontaneously aligned to the applied magnetic field near at the phase transition temperature between the gel and liquid crystalline states (T(m)=24 degrees C), as examined by 31P NMR spectroscopy. The specific interaction between the peptide and lipid bilayer leading to this property was also examined by optical microscopy, light scattering, and potassium ion-selective electrode, together with a comparative study on dynorphin A(1-13). A substantial change in the light scattering intensity was noted for DMPC containing dynorphin A(1-17) near at T(m) but not for the system containing A(1-13). Besides, reversible change in morphology of bilayer, from small lipid particles to large vesicles, was observed by optical microscope at T(m). These results indicate that lysis and fusion of the lipid bilayers are induced by the presence of dynorphin A(1-17). It turned out that the bilayers are spontaneously aligned to the magnetic field above T(m) in parallel with the bilayer surface, because a single 31P NMR signal appeared at the perpendicular position of the 31P chemical shift tensor. In contrast, no such magnetic ordering was noted for DMPC bilayers containing dynorphin A(1-13). It was proved that DMPC bilayer in the presence of dynorphin A(1-17) forms vesicles above T(m), because leakage of potassium ion from the lipid bilayers was observed by potassium ion-selective electrode after adding Triton X-100. It is concluded that DMPC bilayer consists of elongated vesicles with the long axis parallel to the magnetic field, together with the data of microscopic observation of cylindrical shape of the vesicles. Further, the long axis is found to be at least five times longer than the short axis of the elongated vesicles in view of simulated 31P NMR lineshape.     

Electrophoretic and cytological evidence for genetic heterogeneity and the hybrid origin ofAthyrium oblitescens

Athyrium oblitescens, a putative hybrid species, was examined electrophoretically and cytologically to clarify its origin. Allozyme data showed thatA. oblitescens consisted of at least three allozyme types, designated Type C, Type O and Type W. Genotypic compositions of Type C and Type W suggested that they were derived from independent hybridizations betweenA. otophorum andA. clivicola and betweenA. otophorum andA. wardii, respectively. Contrary to previous reports of tetraploidy inA. oblitescens and its hypothesized parent species, cytological observation revealed that Type C and Type W were both hexaploids. Possible pathways for the origin of these hexaploids are proposed. Type O was not genetically distinct fromA. otophorum by either electrophoretic or cytological analyses, and thus there was no evidence of hybrid origin.