Efficient sialylation on azidododecyl lactosides by using B16 melanoma cells

Lactoside primers (dodecyl lactoside derivatives) resemble intermediates in the biosynthetic pathway of glycolipids and, therefore, act as substrates for cellular enzyme-catalyzed glycosylation. To establish the optimal condition for the bioproduction of a large amount of valuable materials containing GM3-type oligosaccharides, two kinds of lactoside primers having the azido group in different positions were synthesized and introduced into B16 melanoma cells. The saccharide chains of both primers were elongated by cells to give GM3-type oligosaccharide derivatives, which were released to the culture medium. The amount of glycosylated product from newly synthesized 2-azidododecyl beta-lactoside (primer II) was almost twice that from 12-azidododecyl beta-lactoside (primer I). The effects of seeded cell number, primer concentration, and length of incubation time on the glycosylation efficiency were also investigated. The results showed that the higher the seeded cell number, the larger the amount of sialylated products obtained. The optimum concentrations of primers I and II were found to be 200 and 100 microM, respectively. Above these concentrations, productivity and cell viability decreased. As regards the length of incubation time, the sialylated products increased linearly until 48 h, but productivity did not advance thereafter. These results represent the optimal conditions that are necessary for the mass production of GM3-type oligosaccharide using azidododecyl lactoside primers and B16 cells.     

Hominid mandibular remains from Sangiran: 1952-1986 collection

Eight hominid mandibular and associated dental remains discovered between 1952-1986 from the Early Pleistocene deposits of Sangiran, Central Java, are described. Although the specimens are surface finds, their original stratigraphic positions can be reasonably inferred on the basis of coincidental sources of information. These specimens significantly increase the dento-gnathic sample available for intensive morphological investigation of the earliest Javanese hominids [Kaifu et al., 2005].     

Oxidation and epimerization of epigallocatechin in banana fruits

To examine the metabolism of proanthocyanidins in banana fruit, (-)-epigallocatechin was treated with the homogenate of the fruit flesh to yield (-)-gallocatechin and an oxidation product, 1-(3,4,5-trihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)-2-hydroxy-1-propan one. The latter product is a stable form of a key intermediate in the oxidative metabolism of flavan-3-ols, and is also related to the biogenesis of A-type proanthocyanidins. In addition, treatment of the reaction mixture with o-phenylenediamine afforded monomeric and dimeric phenazine derivatives generated by condensation with the o-quinone form of the oxidation product.     

A comprehensive classification system for lipids

Lipids are produced, transported, and recognized by the concerted actions of numerous enzymes, binding proteins, and receptors. A comprehensive analysis of lipid molecules, "lipidomics," in the context of genomics and proteomics is crucial to understanding cellular physiology and pathology; consequently, lipid biology has become a major research target of the postgenomic revolution and systems biology. To facilitate international communication about lipids, a comprehensive classification of lipids with a common platform that is compatible with informatics requirements has been developed to deal with the massive amounts of data that will be generated by our lipid community. As an initial step in this development, we divide lipids into eight categories (fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterol lipids, prenol lipids, saccharolipids, and polyketides) containing distinct classes and subclasses of molecules, devise a common manner of representing the chemical structures of individual lipids and their derivatives, and provide a 12 digit identifier for each unique lipid molecule. The lipid classification scheme is chemically based and driven by the distinct hydrophobic and hydrophilic elements that compose the lipid. This structured vocabulary will facilitate the systematization of lipid biology and enable the cataloging of lipids and their properties in a way that is compatible with other macromolecular databases.     

Identification of genes expressed in response to acid stress in Synechocystis sp. PCC 6803 using DNA microarrays

Plant cells are always exposed to various environmental stresses such as high light, low temperature and acid rain, and thus have to respond in order to survive these stresses. Although some mechanisms of responses to high light and low temperature etc., have been clarified, there is little information about the acclimation process to acid stress. In this study, the gene expression changes of Synechocystis sp. PCC 6803 in response to acid stress were examined using DNA microarrays (CyanoCHIP). We compared gene expression profiles of the cells treated at pH 8 (control) and pH 3 for 0.5, 1, 2 or 4 h. As a result, we found that 32 genes were upregulated by more than 3-fold, and 29 genes were downregulated by at least 3-fold after the acid treatment. Among these upregulated genes, expressions of slr0967 and sll0939 kept-increasing until 4 h under the acid stress and increased by 7 to 16-fold after the 4 h treatment. This suggests that the products of these two genes play important roles in the acid acclimation process.     

Alpha-smooth muscle actin expression identifies subpopulations of mouse lymph node non-hematopoietic cells

Significant attention has been given to the role played by non-hematopoietic cells in the immune organs, including the lymph nodes, in hopes of understanding the development, maintenance, and regulation of the immune system. However, the molecular and cellular characterization of non-hematopoietic cells is still in its infancy. Here we show that non-hematopoietic cells in mouse lymph nodes can be fractionated into previously unidentified subpopulations according to the transgenic reporter expression of alpha-smooth muscle actin (αSMA). αSMA⁺ non-hematopoietic cells were predominantly detected in gp38⁺CD31⁻ and gp38⁻CD31⁻ cells. Molecular expression profiles suggest similarities between αSMA⁺gp38⁺CD31⁻ and αSMA⁻gp38⁺CD31⁻ subpopulations and dissimilarities between αSMA⁺gp38⁻CD31⁻ and αSMA⁻gp38⁻CD31⁻ subpopulations. The results indicate that αSMA is a useful marker for further understanding the molecular and cellular characteristics of non-hematopoietic cells in the lymph nodes.     

The anamorphic genus Calcarisporiella is a new member of the Mucoromycotina

The phylogenetic position of the anamorphic genus Calcarisporiella was investigated. Three isolates of Calcarisporiella, including an authentic strain and a newly obtained isolate, were analyzed phylogenetically using rDNA sequences. The result indicated that Calcarisporiella, which was classified as an ascomycetous anamorph, is a member of Mucoromycotina. It formed an independent clade separated from the other known orders of this subphylum.     

IRS1-independent defects define major nodes of insulin resistance

Insulin resistance is a common disorder caused by a wide variety of physiological insults, some of which include poor diet, inflammation, anti-inflammatory steroids, hyperinsulinemia, and dyslipidemia. The common link between these diverse insults and insulin resistance is widely considered to involve impaired insulin signaling, particularly at the level of the insulin receptor substrate (IRS). To test this model, we utilized a heterologous system involving the platelet-derived growth factor (PDGF) pathway that recapitulates many aspects of insulin action independently of IRS. We comprehensively analyzed six models of insulin resistance in three experimental systems and consistently observed defects in both insulin and PDGF action despite a range of insult-specific defects within the IRS-Akt nexus. These findings indicate that while insulin resistance is associated with multiple deficiencies, the most deleterious defects and the origin of insulin resistance occur independently of IRS.     

An analysis of long-distance water transport in the soybean stem using H215O

The lateral water movement in the intact stem of a transpiring soybean plant was analyzed quantitatively by a real-time measurement system utilizing labeled water, H(2)(15)O and gamma ray detectors. A large volume of water escaping from xylem vessels during its transport was detected. The escape of water was not influenced by evaporation from the stem surface or mass flow in the sieve tubes. It was assumed that the total amount of water transported through xylem vessels was kept almost completely constant along the internode. As a result, most of the escaped water was found to re-enter the xylem vessels, i.e. water exchange occurred. The analysis of radiographs of tritiated water suggested that the self-diffusion effect of water was strong for lateral water movement, although another driving force besides thermal motion was included in the process, and that the process was also affected by the water permeability of the plasma membrane. An analysis based on a mathematical model showed that the net volume of water which escaped from xylem vessels was not dependent on the transpiration rate of the plant.     

Fluorescent method for detection of cleaved collagens using O-phthaldialdehyde (OPA)

Analysis of collagen degradation remains an important but cumbersome task. Traditional methods with dansyl chloride derivatization of collagen have been used to quantify collagen damage. Fluorescent labeling reagents have been developed that offer advantages such as greater solubility in water and low background emission. One such reagent is o-phthalaldehyde (OPA). In this study, we used OPA as a means of detecting small amounts of degraded collagen. Collagen samples isolated from skin or heart were used for OPA conjugation to exposed amino termini (“opalation”). Experiments utilizing small samples aliquoted in microtiter plates were performed to evaluate effects of increasing concentrations of OPA, varying concentrations of collagen, and effects of matrix metalloproteinase (MMP) digestion. Results indicate that within 10 min of reaction, OPA can be used to detect relative differences in cleaved vs. uncleaved collagen from skin or heart. Heart samples obtained from regions of high MMP activity correlated with increased OPA fluorescence relative to tissue with lower MMP activity. On the basis of these results, we conclude that OPA has valuable practical advantages for analytical use in detecting cleaved collagen in small tissue samples.