Reconstitution of glucose dehydrogenases using synthetic methoxatin

Synthetic methoxatin or its reduced derivative, is fully active in the reconstitution of glucose dehydrogenase from Acinetobacter calcoaceticus var. anitratus from apoenzyme, and is also active in a similar reconstitution of enzyme from A. calcoaceticus ATCC 9956. However, we have still not been able to reconstitute holoenzyme of methanol dehydrogenase from Pseudomonas TPI.     

Phylogenetic relationships and convergent evolution of ocean‐shore ground beetles (Coleoptera: Carabidae: Trechinae: Bembidion and relatives)

Through phylogenetic analysis of seven genes, we show that there have been at least six independent entries into intertidal habitats in the history of bembidiine carabids, in the ancestors of: (i) Orzolina Machado, (ii) Bembidion (Desarmatocillenus Netolitzky), (iii) Bembidion laticeps (LeConte) + palosverdes Kavanaugh & Erwin, (iv) Bembidion laterale (Samouelle), (v) Bembidion umi Sasakawa and Bembidion quadriimpressum (Motschulsky) (which may represent two separate entries), and (vi) B. nigropiceum (Marsham). The following lineages are widely separated within the subtribe Bembidiina: Orzolina is sister to the genus Ocys Stephens; subgenus Desarmatocillenus appears to be sister to all Bembidion Latreille excluding subgenus Phyla Motschulsky; B. laticeps + B. palosverdes is a clade in the Bembidion series; B. laterale is a member of the Princidium Motschulsky complex; B. umi and B. quadriimpressum are related to the Nearctic Clade of the Ocydromus Clairville complex; B. nigropiceum is sister to B. praeustum Dejean among sampled species. There are three separate lineages of ocean‐shore bembidiines that are known to prey on amphipods, and adults of these lineages [Bembidion (Desarmatocillenus), B. laterale, and B. mandibulare Solier] have unusually wide heads with long mandibles. Also common among independent lineages restricted to ocean shores are prominent front angles of the prothorax, larger numbers of setae on the elytral disc, a notable sinuation in the margin of each elytron near its apex, and short, wide mesotarsi. The reasons for the repeated evolution of these features are not evident. Our results also suggest that inland species of the Nearctic Clade may have arisen from an ocean‐shore ancestor. The close genetic similarities between the gravel river shore dwelling B. praeustum and the intertidal specialist B. nigropiceum suggest that the striking morphological adaptations of B. nigropiceum to the intertidal zone arose rapidly. We make one nomenclatural change: we resurrect the subgenus Lymneops Casey to accommodate B. palosverdes and B. laticeps.     

Comparison of the expression of cell surface poly-N-acetyllactosamine-type oligosaccharides in PC12 cells with those in its variant PC12D.

To explore the biological role of carbohydrate chains in the process of nerve cell differentiation, we carried out a characterization of the carbohydrate structure of glycoproteins by comparing conventional PC12 cells with variant cells (PC12D). In vitro metabolic labeling of cells with either [(3)H] glucosamine or [(3)H] threonine, together with tomato lectin staining, revealed that nerve growth factor (NGF) stimulation caused a decrease in the poly-N-acetyllactosamine synthesis of high-molecular-weight glycopeptides from PC12 cells. By comparison, the amount of glycopeptides with poly-N-acetyllactosamine from PC12D cells was already significantly low and it was not changed by NGF stimulation. By assaying the glycosyltransferases that participate in poly-N-acetyllactosamine synthesis, the decrease in the amount of the poly-N-acetyllactosamine in PC12D cells as well as NGF-stimulated PC12 cells could be accounted for by a reduction in the activity of poly-N-acetyllactosamine extension enzyme (GnT-i), because the amount of poly-N-acetyllactosamine in both cells precisely correlated with changes in GnT-i activity, whereas the activities of N-acetylglucosaminyltransferase V (GnT-V) and beta 1-4 galactosyltransferase remained unchanged. These results demonstrate that the decrease in poly-N-acetyllactosamine synthesis in PC12 cells occurred prior to neurite formation, whereas PC12D cells were insensitive to this effect. Next, we showed that GnT-i but not GnT-V catalyzed a rate-limiting reaction in the expression of poly-N-acetyllactosamine chains, especially in pheochromocytoma.     

Influence of surface anesthesia on the pressure pain threshold measured with different-sized probes

Transcutaneous pressure with pressure probes of arbitrary diameters have been commonly used for measuring the threshold and magnitude of muscle pain, yet this procedure lacks scientific validation. To examine the valid probe dimensions, we conducted physiological experiments using 34 human subjects. Pin-prick pain, pressure pain threshold (PPT) to pressure probes of various diameters, heat pain threshold, and electrical pain threshold of deep tissues were measured before and after application of surface lidocaine anesthesia to the skin surface over the brachioradial muscle in a double-blinded manner. The anesthesia neither affected PPT with larger probes (diameters: 1.6 and 15?mm) nor increased electric pain threshold of deep structures, whereas it diminished pain count in pin-prick test and PPT with a 1.0?mm diameter probe, suggesting that mechanical pain thresholds measured with 1.6 and 15?mm probes reflect the pain threshold of deep tissues, possibly muscle. Pain thresholds to heat did not change after application of the anesthesia. These results suggest that larger pressure probes can give a better estimation of muscular pain threshold.     

Agricultural Activities of a Meadow Eliminated Plant Litter from the Periphery of a Farmland in Inner Mongolia,China

The purpose of our investigation was to clarify the effects of agriculture on the process of loss of litter at the periphery of a farmland. This study revealed the generation process of an ecologically unusual phenomenon that is observed around cropland in semi-arid regions. We hypothesized that the vegetation around a farmland cannot supply plant litter to the ground surface because the ecological structure has been changed by agricultural activities. The study was conducted at Xilingol steppe, Xilingol League, Inner Mongolia Autonomous Region, China. Four study lines were established from the edge of an arable field to the surrounding meadow and parallel to the wind direction during the strong wind season. Key measurement for each line was set at the border between the farmland and steppe. Four study sites were set at intervals along each line. Plant litter, soil particle size distribution, plant species composition, plant volume, and species diversity were investigated. Despite using the same mowing method at the meadows of all study sites, the litter at the only periphery of the farmland completely disappeared. Soil particle size distribution in steppe, which was adjacent to the farmland, was similar to that of the farmland. Plant community structure at the periphery of the farmland was different from that of the far side from the farmland. This implies that soil scattered from the farmland affected the species composition of the steppe. Consequently, the change in plant community structure induced litter loss because of mowing. We concluded that plant litter was lost near the farmland because of the combined effects of farming and mowing. The results support our hypothesis that the vegetation around a farmland cannot supply plant litter because the ecological structure has been changed by agricultural activities.