Isolation and Characterization of the Serotype g Carbohydrate Moiety from an Enzyme Lysate of Streptococcus mutans 6715 Cell Walls

The serotype-specific carbohydrate moiety of Streptococcus mutans was isolated by mild degradation of purified cell walls with a cell-wall lytic enzyme. Cell walls of serotype g S. mutans strain 6715 were digested with M1 enzyme, an endo-N-acetylmuramidase purified from culture supernatants of Streptomyces globisporus strain 1829. The enzyme lysate of the cell walls was applied to a CM Sephadex C-25 column to remove the M1 enzyme from the cell wall lysate and then subjected to Sephadex G-100 column chromatography. Carbohydrate antigens with serotype g specificity, designated M1g, and a peptidoglycan—polysaccharide complex lacking serotype specificity (M1PG) were separated. Purified serotype g antigen was also obtained by autoclaving the S. mutans 6715 whole cells in saline at 120 C for 30 min. The extract was applied to a DEAE Sephadex A-25 column to remove nucleic acids and teichoic acids. The unbound peak fraction was concentrated and re-chromatographed on a Bio-Gel P-100 column. The void volume fraction contained serotype g carbohydrate and was designated RRg antigen. M1g and RRg antigens formed a band of identity with anti-serotype g serum by immunodiffusion. These antigens were composed mainly of galactose, glucose, and rhamnose at an approximate weight ratio of 8 : 4 : 1, while constituent sugars of M1PG consisted of rhamnose and glucose, with no detectable galactose. M1g also contained peptidoglycan residues other than threonine, an interpeptide bridge component of the native cell wall peptidoglycan. Marked inhibition of the quantitative precipitin reaction between M1g and anti-serotype g serum was obtained with melibiose and galactose, which suggests that the immunodeterminant of the serotype g carbohydrate is an α-linked galactose-glucose terminal linkage.     

Genetic control of alkaline phosphatase isozymes in chicken duodenum

A genetic control of alkaline phosphatase (AP) in chicken duodenum was studied in a White Plymouth Rock strain. Unpurified chicken duodenum AP heated in an extraction procedure comprised either F or S band by isozyme types. On the other hand, chromatographically purified intestinal AP (NBCo, USA) had three bands, i.e., F', S' and B' bands. Characterization by urea, heat and neuraminidase treatments suggested that the genetic control of plasma AP isozymes may be applicable to the duodenum AP isozymes.     

Rainwater storage/infiltration function of rain gardens for management of urban storm runoff in Japan

Landscape and Ecological Engineering - Rain gardens have recently gained popularity in Japan for the management of urban storm runoff. However, due to limited expertise regarding the technical...     

Secondary somatosensory area is involved in vibrotactile temporal-structure processing: MEG analysis of slow cortical potential shifts in humans

Abstract

Purpose: Temporal-structure discrimination is an essential dimension of tactile processing. Exploring object surface by touch generates vibrotactile input with various temporal dynamics, which gives diversity to tactile percepts. Here, we examined whether slow cortical potential shifts (SCPs) (<1?Hz) evoked by long vibrotactile stimuli can reflect active temporal-structure processing.

Materials and methods: Vibrotactile-evoked magnetic brain responses were recorded in 10 right-handed healthy volunteers using a piezoelectric-based stimulator and whole-head magnetoencephalography. A series of vibrotactile train stimuli with various temporal structures were delivered to the right index finger. While all trains consisted of identical number (15) of stimuli delivered within a fixed duration (1500?ms), temporal structures were varied by modulating inter-stimulus intervals (ISIs). Participants judged regularity/irregularity of ISI for each train in the active condition, whereas they ignored the stimuli while performing a visual distraction task in the passive condition. We analysed the spatiotemporal features of SCPs and their behaviour using the minimum norm estimates with the dynamic statistical parametric mapping.

Results: SCPs were localized to contralateral primary somatosensory area (S1), contralateral superior temporal gyrus, and contralateral as well as ipsilateral secondary somatosensory areas (S2). A significant enhancement of SCPs was observed in the ipsilateral S2 (S2i) in the active condition, whereas such effects were absent in the other regions. We also found a significant larger amplitude difference between the regular- and irregular-stimulus evoked S2i responses during the active condition than during the passive condition.

Conclusions: This study suggests that S2 subserves the temporal dimension of vibrotactile processing.     

Change of Cu,Zn-superoxide Dismutase Activity of Guinea Pig Lung in Experimental Asthma

Correlation between the level of reactive oxygen species (ROS) generated by airway inflammatory cells and superoxide dismutase (SOD) activity of pulmonary tissue during an asthma attach was investigated in a guinea pig model of allergic asthma. In addition, the influence of SOD inhibition by diethyldithiocarbamate (DDC, Cu-chelating agent) on the airway was investigated in terms of pulmonary function during an asthma attach. Relative to controls, the capacity of bronchoalveolar lavage fluid (BAL) cells to release ROS was significantly increased in guinea pigs sensitized with ovalbumin (OA) as the antigen, and significantly increased in guinea pigs with an asthma attack provoked by the inhalation of OA. SOD activity was increased significantly in the antigen-sensitized group. The asthma provocation group showed a tendency for increase in total SOD activity, compared with the sensitization group, whose increase was dependent on the increase in copper, zinc-SOD (Cu, Zn-SOD) activity. Pretreatment with DDC increased the severity and duration of the asthma attack. These results were indicated that Cu, Zn-SOD was closely involved in the asthma process, particularly in the scavenging of oxygen radicals secreted from BAL cells.     

IAA-induced hyperpolarization of the membrane potential in isolated cells fromMimosa pulvinus

Upon treatment with 10⁻⁴ M IAA the membrane potential of an isolated cell from the main pulvinus, ofMimosa pudica L. depolarized by about 6 mV in 2–5 min, but later it gradually hyperpolarized by about 30 mV. The membrane potential of a motor cell in the main pulvinar tissue hyperpolarized by about 80 mV 1 hr after application of 10⁻⁴ M IAA.     

Mitochondrial DNA divergence in yoshinobori gobies (Rhinogobius species complex) between the Bonin Islands and the Japan–Ryukyu Archipelago

To investigate the genetic differentiation between the Bonin (Ogasawara) Islands' freshwater goby Rhinogobius sp. Bonin Island (BI) form (Ogasawara-yoshinobori) and the Japan–Ryukyu Archipelago relatives, the mitochondrial DNA (mtDNA) phylogeny of Japanese Rhinogobius species was inferred from partial nucleotide sequences of the mitochondrial NADH dehydrogenase 5 subunit (ND5) gene (945 bp). The resultant tree showed that the Bonin Islands group separated first from the other Japanese lineage, and a test calculation indicated the divergence date to be approximately 3 million years BP. Although it is necessary to use a more reliable estimate to confirm the divergence date, Rhinogobius sp. BI has retained its mtDNA lineage in the islands for millions of years.     

Adiponectin and AMP kinase activator stimulate proliferation,differentiation, and mineralization of osteoblastic MC3T3-E1 cells

Background  

Adiponectin is a key mediator of the metabolic syndrome that is caused by visceral fat accumulation. Adiponectin and its receptors are known to be expressed in osteoblasts, but their actions with regard to bone metabolism are still unclear. In this study, we investigated the effects of adiponectin on the proliferation, differentiation, and mineralization of osteoblastic MC3T3-E1 cells.