Insulin-like growth factors,hepatocyte growth factor and transforming growth factor-alpha in mouse tongue myogenesis

Many reports have shown that tongue striated muscles have several unique characteristics not found in other skeletal muscles such as limb and trunk. Several peptide growth factors are reported to play important roles in skeletal myogenesis. In this article, the roles of insulin-like growth factors (IGF), hepatocyte growth factor (HGF) and transforming growth factor (TGF)-alpha in mouse tongue myogenesis were studied using an organ culture system of the mandible or tongue obtained from mouse embryos. It was found that IGF-I promotes the differentiation of tongue myoblasts. HGF plays an essential role in the migration and proliferation of tongue myogenic cells, and inhibits the differentiation of tongue myoblasts. TGF-alpha does not play an essential role in the proliferation of tongue myogenic cells, but does promote the early differentiation of tongue myoblasts. The role of IGF-I in the differentiation of tongue myoblasts, and that of HGF in the migration, proliferation and differentiation of tongue myogenic cells appear to be almost identical to their roles in the myogenesis of limb and cultured myogenic cell lines. However, the role of TGF-alpha in the proliferation and differentiation of tongue myogenic cells appears to be different from its role in the myogenesis of limb and cultured myogenic cell lines such as C2 and L6.     

Structure and immunocytochemical localization of photosynthetic enzymes in the lamina joint and sheath pulvinus of the C4 grass Arundinella hirta

The C₄ grass Arundinella hirta exhibits a unique C₄ anatomy, with isolated Kranz cells (distinctive cells) and C₄-type expression of photosynthetic enzymes in the leaf sheath and stem as well as in the leaf blade. The border zones between these organs are pale green. Those between the leaf blade and sheath and between the sheath and stem are called the lamina joint and sheath pulvinus, respectively, and are involved in gravity sensing. We investigated the structure and localization of C₃ and C₄ photosynthetic enzymes in these tissues. In both zones the epidermis lacked stomata. The inner tissue was composed of parenchyma cells and vascular bundles. The parenchyma cells were densely packed with small intercellular spaces and contained granal chloroplasts with large starch grains. No C₄-type cellular differentiation was recognized. Western blot analysis showed that the lamina joint and pulvinus accumulated substantial amounts of phosphoenolpyruvate carboxylase (PEPC), pyruvate,Pi dikinase (PPDK), and ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco). Immunogold electron microscopy revealed PEPC in the cytosol and both PPDK and rubisco in the chloroplasts of parenchyma cells, suggesting the occurrence of C₃ and C₄ enzymes within a single type of chlorenchyma cell. These data indicate that the lamina joint and pulvinus have unique expression patterns of C₃ and C₄ enzymes, unlike those in C₄-type anatomy.     

Niche Separation of Methanotrophic Archaea (ANME-1 and -2) in Methane-Seep Sediments of the Eastern Japan Sea Offshore Joetsu

In this study, we investigated the diversity and spatial distribution of anaerobic methanotrophic archaea (ANMEs) in sediments of a gas hydrate field off Joetsu in the Japan Sea. Distribution of ANMEs in sediments was identified by targeting the gene for methyl coenzyme M reductase alpha subunit (mcrA), a phylogenetically conserved gene that occurs uniquely in methanotrophic and methanogenic archaea, in addition to 16S rRNA genes. Quantitative PCR analyses of mcrA genes in 14 piston core samples suggested that members of ANME-1 group would dominate AOM communities in sulfate-depleted sediments, even below the sulfate-methane interface, while ANME-2 archaea would prefer to populate in shallower sediments containing comparatively higher sulfate concentrations. These results suggest that, although the potential electron acceptors in sulfate-depleted habitats remain elusive, the niche separation of ANME-1 and -2 may be controlled by in situ concentration of sulfate and the availability in sediments.     

A Clostridium perfringens Vector for the Selection of Promoters

A promoter selection vector for Clostridium perfringens genes was constructed from a C. perfringens-Escherichia coli shuttle vector, pJIR418. The plasmid carries a promoterless chloramphenicol acetyltransferase gene (catP), derived from pIP401, downstream of the multiple cloning sites of pUC18. When a promoter region of the phospholipase C gene was inserted into one of the cloning sites, derivatives of C. perfringens strain 13 carrying the resultant plasmid acquired resistance to chloramphenicol. This plasmid should be a useful reporter system for C. perfringens genes.     

The histological analysis,colorimetric evaluation,and chemical quantification of melanin content in ‘suntanned’ fish

Human melanocytes respond to UV irradiation by increasing the synthesis of melanin. While much is now understood of the pathways governing this process and the nature of the melanin synthesized, little is known of melanins produced by lower vertebrates and their capacity to respond to UV. Here we report that a fish, red seabream, can undergo ‘suntanning’. Histological, colorimetric and chemical assays were performed for suntanned red seabream fish bred in net cages to analyse the melanins and compared with shaded or wild red seabream fish. For color evaluation, the L* values of suntanned fish were dramatically lower than those in the other two groups. Pyrrole‐2,3,5‐tricarboxylic acid (PTCA), an indicator of eumelanin, was detected in suntanned fish at five times higher levels than in shaded or wild fish while 4‐amino‐3‐hydroxyphenyl‐alanine (4‐AHP), a marker for pheomelanin, could not be detected in any of the samples. Histological analysis showed that melanocytes in the suntanned skin enlarged and increased in number to form a monolayer at the surface of the skin. Analysis of L* values and PTCA levels showed quite a high correlation coefficient (r = ?0.843). When comparing shaded and wild red seabream fish, the scores were closer but some significant differences were still found in some body areas. These results indicate that eumelanin accumulates in suntanned fish during the increase in skin color, which is induced by sunlight, presumably by ultraviolet radiation.     

Liquid chromatographic determination of acetylcholine based on pre‐column alkaline cleavage reaction and post‐column tris(2,2′‐bipyridyl)ruthenium(III) chemiluminescence detection

A method for the determination of acetylcholine (ACh) has been developed using liquid chromatography with chemiluminescence detection. This method is based on the pre‐column alkaline cleavage of ACh to form trimethylamine (TMA) and the post‐column tris(2,2′‐bipyridyl)ruthenium(III) chemiluminescence detection of TMA. ACh was converted to TMA with high yield at 180°C in the presence of lithium hydroxide, and the produced TMA was separated on a cation‐exchange/reversed‐phase dual‐functional column using a mixture of 0.2 m potassium phosphate buffer (pH 5.9) and acetonitrile (20:1, v/v) as the mobile phase. The eluate was online mixed with acidic tris(2,2′‐bipyridyl)ruthenium(III) solution, and the generated chemiluminescence was detected. The detection limit (signal‐to‐noise ratio = 3) for ACh was 0.80 nmol/mL, which corresponded to 1.1 pmol TMA per injection volume of 5 µL. This is simple and robust method that does not need an expensive device and unstable enzymes, and was applied to the determination of ACh in pharmaceutical formulations. Copyright © 2009 John Wiley & Sons, Ltd.     

Blocking O-linked GlcNAc cycling in Drosophila insulin-producing cells perturbs glucose-insulin homeostasis

A dynamic cycle of O-linked GlcNAc (O-GlcNAc) addition and removal is catalyzed by O-GlcNAc transferase and O-GlcNAcase, respectively, in a process that serves as the final step in a nutrient-driven "hexosamine-signaling pathway." Evidence points to a role for O-GlcNAc cycling in diabetes and insulin resistance. We have used Drosophila melanogaster to determine whether O-GlcNAc metabolism plays a role in modulating Drosophila insulin-like peptide (dilp) production and insulin signaling. We employed transgenesis to either overexpress or knock down Drosophila Ogt(sxc) and Oga in insulin-producing cells (IPCs) or fat bodies using the GAL4-UAS system. Knockdown of Ogt decreased Dilp2, Dilp3, and Dilp5 production, with reduced body size and decreased phosphorylation of Akt in vivo. In contrast, knockdown of Oga increased Dilp2, Dilp3, and Dilp5 production, increased body size, and enhanced phosphorylation of Akt in vivo. However, knockdown of either Ogt(sxc) or Oga in the IPCs increased the hemolymph carbohydrate concentration. Furthermore, phosphorylation of Akt stimulated by extraneous insulin in an ex vivo cultured fat body of third instar larvae was diminished in strains subjected to IPC knockdown of Ogt or Oga. Knockdown of O-GlcNAc cycling enzymes in the fat body dramatically reduced neutral lipid stores. These results demonstrate that altered O-GlcNAc cycling in Drosophila IPCs modulates insulin production and influences the insulin responsiveness of peripheral tissues. The observed phenotypes in O-GlcNAc cycling mimic pancreatic β-cell dysfunction and glucose toxicity related to sustained hyperglycemia in mammals.     

Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis

BackgroundAlthough several computer-aided computed tomography (CT) analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF), it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.ObjectiveThe purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.MethodsA total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR) CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology) staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT), the normally attenuated lung volume as defined from −950 HU to −701 Hounsfield unit (NL), the volume of the whole lung (WL), and the percentage of NL to WL (NL%), were calculated.ResultsCT indices (MCT, WL, and NL) closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC) (r = 0.92, P <0.0001). NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]).ConclusionThe measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.