The effect of protozoa on the composition of rumen bacteria in cattle using 16S rRNA gene clone libraries

The effect of the presence of protozoa on the composition of rumen bacteria was investigated in cattle. Seven castrated Holstein cattle were divided into two groups: four faunated and three unfaunated, and 16S ribosomal RNA gene (rDNA) clonal libraries were constructed. A total of 312 clones were sequenced across 1,500 bp. The 151 sequences of the faunated cattle were classified into 98 operational taxonomic units (OTUs) having at least 97% similarity. The sequences derived from the faunated cattle were classified into Firmicutes (59.7%), Bacteroidetes (34.4%), Spirochaetes (2.6%), Actinobacteria (2.0%), and Proteobacteria (1.3%). Bacteroides and Prevotella (34.4%) were the major groups in the faunated cattle. The 161 sequences in the unfaunated cattle were classified into 72 OTUs. The sequences derived from the unfaunated libraries were classified into Firmicutes (65.7%), Bacteroidetes (31.1%), Proteobacteria (1.9%), and Spirochaetes (1.2%). The Clostridium botulinum group and its relatives (36.0%) were the major groups in the unfaunated cattle.An analysis by the computer program LIBSHUFF clarified that the presence of ruminal protozoa markedly affected the composition of rumen bacteria.     

Comparative studies on the functional roles of N- and C-terminal regions of molluskan and vertebrate troponin-I

Vertebrate troponin regulates muscle contraction through alternative binding of the C-terminal region of the inhibitory subunit, troponin-I (TnI), to actin or troponin-C (TnC) in a Ca(2+)-dependent manner. To elucidate the molecular mechanisms of this regulation by molluskan troponin, we compared the functional properties of the recombinant fragments of Akazara scallop TnI and rabbit fast skeletal TnI. The C-terminal fragment of Akazara scallop TnI (ATnI(232-292)), which contains the inhibitory region (residues 104-115 of rabbit TnI) and the regulatory TnC-binding site (residues 116-131), bound actin-tropomyosin and inhibited actomyosin-tropomyosin Mg-ATPase. However, it did not interact with TnC, even in the presence of Ca(2+). These results indicated that the mechanism involved in the alternative binding of this region was not observed in molluskan troponin. On the other hand, ATnI(130-252), which contains the structural TnC-binding site (residues 1-30 of rabbit TnI) and the inhibitory region, bound strongly to both actin and TnC. Moreover, the ternary complex consisting of this fragment, troponin-T, and TnC activated the ATPase in a Ca(2+)-dependent manner almost as effectively as intact Akazara scallop troponin. Therefore, Akazara scallop troponin regulates the contraction through the activating mechanisms that involve the region spanning from the structural TnC-binding site to the inhibitory region of TnI. Together with the observation that corresponding rabbit TnI-fragment (RTnI(1-116)) shows similar activating effects, these findings suggest the importance of the TnI N-terminal region not only for maintaining the structural integrity of troponin complex but also for Ca(2+)-dependent activation.     

Electrical detection of biomolecular adsorption on sprayed graphene sheets

The binding affinities of graphite-binding peptides to a graphite surface were electrically characterized using sprayed graphene field effect transistors (SGFETs) fabricated with solution exfoliated graphene. The binding affinities of these peptides were also characterized using atomic force microscopy (AFM) and mechanically exfoliated graphene field effect transistors (GFETs) to confirm the validity of the SGFET platform. Binding constants obtained via GFET and AFM were comparable with those observed using SGFETs. The sprayed graphene film serves as a scalable platform to study biomolecular adsorption to graphitic surfaces.     

The Abstracts of Worldsleep2011

Sleep and Biological Rhythms -     

Plasma adrenomedullin as an independent predictor of future cardiovascular events in high-risk patients: comparison with C-reactive protein and adiponectin

This study investigated the predictive power of plasma adrenomedullin (AM) for future cardiovascular (CV) events. In 121 patients with multiple CV risk factors and/or disease, plasma concentrations of AM, high sensitive C-reactive protein (hs-CRP), and adiponectin were measured. During follow-up periods (mean, 3.5 years) after the baseline assessment, 28 patients newly experienced CV events such as stroke/transient ischemic attack, acute coronary syndrome, and congestive heart failure. The plasma level of AM, but not hs-CRP or adiponectin, was significantly higher in patients who had CV events than in event-free subjects. When the patients were divided into three groups by tertiles of basal levels of AM (<10.1, 10.1-13.1, and > or =13.1 fmol/mL), cumulative event-free rates by the Kaplan-Meier method were decreased according to the increase in basal AM levels (83.2%, 68.6%, and 52.8% in the lowest, middle, and highest tertiles of AM, respectively; log-rank test, P=0.033). By univariate Cox regression analysis, previous coronary artery disease, creatinine clearance, and plasma AM and hs-CRP levels were significantly associated with CV events during follow-up. Among these possible predictors, high plasma AM (P=0.004) and low creatinine clearance (P=0.043) were independent determinants for morbidity in multivariate analysis. These findings indicate that plasma AM is a powerful independent predictor of future CV events in high-risk patients, suggesting its predictive value is superior to that of hs-CRP or adiponectin.     

Endothelium-dependent vasorelaxation effect of rutin-free tartary buckwheat extract in isolated rat thoracic aorta

The aim of this study was to point out the potential of tartary buckwheat on vascular functions. A nonabsorbed fraction of hot-water extract of tartary buckwheat on a SP70 column (TBSP-T), which was free from rutin, was used for this aim. In a contractile experiment using Sprague-Dawley rat thoracic aorta rings contracted by 1.0 microM phenylephrine (PE) or 50 mM KCl, TBSP-T evoked a significant vasorelaxation [EC50 (mg/ml): PE; 2.2; KCl, 1.9]. By a further fractionation of TBSP-T by liquid-liquid partitioning into basic, neutral and acidic fractions, a marked enhancement of vasorelaxation effect was observed only for acidic fraction (EC50, 0.25 mg/ml). The action of acidic fraction was significantly attenuated in endothelium-denuded aortic rings and in the presence of nitric oxide synthase inhibitor, NG-monomethyl-L-arginine (100 microM). The fraction also enhanced the cyclic guanosine monophosphate (cGMP) production in aortic rings contracted with PE [cGMP (pmol/mg protein): PE, 7.2+/-2.3; PE+Acidic fraction, 35+/-8]. These results indicate that acidic fraction could mediate NO/cGMP pathways, thereby exerting endothelium-dependent vasorelaxation action. In conclusion, tartary buckwheat was proven to regulate vascular tones and have latent acidic candidates except for rutin.     

Studies on Phyto-peroxidase

Peroxidase c was isolated and purified from Japanese-radish roots by means of a chromatographic technique with carboxymethyl cellulose. Two or more components exhibiting the absorption spectrum of peroxidase c were separated chromatographically, and the most basic component was crystallized from ammonium sulphate solution. The Reinheit Zahl and the purpurogallin number of the crystalline preparation were found to be 3.55 and 1100 respectively. The absorption maxima were found at 420 and 540 mμ, for the oxidized form and at 425 and 560 mμ for the reduced form. The crystalline preparation contained 1.57% protohematin as the prosthetic group, and then the minimum molecular weight of peroxidase c was found to be 41500.