Continuous production of fructooligosaccharides using fructosyltransferase immobilized on ion exchange resin

A continuous production of fructooligosaccharides from sucrose was investigated by fructosyltransferase immobilized on a high porous resin, Diaion HPA 25. The optimum pH (5.5) and temperature (55°C) of the enzyme for activity was unaltered by immobilization, and the immobilized enzyme became less sensitive to the pH change. The optimal operation conditions of the immobilized enzyme column for maximizing the productivity were as follows: 600 g/L of sucrose feed concentration, flow rate of superficial space velocity 2.7 h^?1. When the enzyme column was run at 50°C, about 8% loss of the initial activity of immobilized enzyme was observed after 30 days of continuous operation, during which high productivity of 1174 g/L·h was achieved. The kinds of products obtained using the immobilized enzyme were almost the same as those using soluble enzymes or free cells.     

TBCD Links Centriologenesis,Spindle Microtubule Dynamics,and Midbody Abscission in Human Cells

Microtubule-organizing centers recruit α- and β-tubulin polypeptides for microtubule nucleation. Tubulin synthesis is complex, requiring five specific cofactors, designated tubulin cofactors (TBCs) A–E, which contribute to various aspects of microtubule dynamics in vivo. Here, we show that tubulin cofactor D (TBCD) is concentrated at the centrosome and midbody, where it participates in centriologenesis, spindle organization, and cell abscission. TBCD exhibits a cell-cycle-specific pattern, localizing on the daughter centriole at G1 and on procentrioles by S, and disappearing from older centrioles at telophase as the protein is recruited to the midbody. Our data show that TBCD overexpression results in microtubule release from the centrosome and G1 arrest, whereas its depletion produces mitotic aberrations and incomplete microtubule retraction at the midbody during cytokinesis. TBCD is recruited to the centriole replication site at the onset of the centrosome duplication cycle. A role in centriologenesis is further supported in differentiating ciliated cells, where TBCD is organized into “centriolar rosettes”. These data suggest that TBCD participates in both canonical and de novo centriolar assembly pathways.     

Flux boundary measurements for the study of tree stability

The shear strength of soil is an important parameter that affects tree stability and can vary depending on the magnitude of the soil’s negative pore-water pressure (matric suction). The surface flux boundary condition affects the matric suction of soil, and therefore is important for tree stability. Field measurements were performed around a roadside tree for 2 years. The instrumentation results show that the matric suction in the soil fluctuated between 0 and 35 kPa. Matric suction changes in the soil could lead to a decrease in the tree resistive moment of up to 80 %.     

An optical multi-sensing system for detection of cardiovascular toxicity

A mini-microscope-based system for multisite detection of cardiovascular toxicity was developed. The mini-microscope consisted of an image sensor and lens module extracted from an inexpensive webcam. The flipped lens module enabled cells to be magnified and monitored during testing. The portability and compactness of this system enables short-term and potential long-term experimentation inside a conventional incubator. The toxicity test results demonstrated that the normalized beating rates of cardiac muscle cells selected from multiple regions increased over time when treated with 100 nM isoprenaline. The presented system could be a promising cost-effective cell-based testing tool for discovering and screening drugs.     

Synthesis and antioxidant properties of dendritic polyphenols

Three dendritic polyphenols (generation 1) were synthesized: a syringaldehyde-based dendrimer (1), a vanillin-based dendrimer (2), and an iodinated vanillin-based dendrimer (3). They all showed strong antioxidant activity according to the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay. The syringaldehyde dendrimer was twice and 10 times stronger than quercetin and Trolox, respectively. The vanillin-based dendrimer and its more hydrophobic iodinated derivative were also more potent antioxidants than quercetin and Trolox. The DPPH order of potency was 1 > 2, 3 > quercetin > Trolox. All three dendrimers also protected human LDL from free radical attack in a dose-dependent manner. Their order of free radical scavenging was 1 > 3 > 2 > quercetin > Trolox. The increased hydrophobic nature of the iodinated derivative may have contributed to its better LDL protection than 2. Protection of linoleic acid oxidation was studied by the β-carotene–linoleate assay. Dendrimer 1 was clearly superior to the other antioxidants in protecting the fatty acid. In case of DNA protection against free radical damage, the order of activity was 1 > quercetin > 2 > 3, Trolox. Pro-oxidant effect on copper-induced DNA oxidation showed the following order: quercetin, Trolox > 1 > 2 > 3. Results of the study show that dendritic antioxidants, even at the generation 1 level, provide promising antioxidant properties for their potential use as drug candidates for diseases associated with oxidative stress.     

Histocompatibility antigens (HLA) in children with lipoid nephrosis]

Actual knowledge on the HLA relationship with the primary glomerulopathies, with particular reference to steroid - sensitive nephrosis of childhood, is surveyed. Occurrence of HLA B-8 and B-35 in this nephropathy has been investigated. The studies involved 47 patients aged between 3 and 15 years and 117 healthy children from Lower Silesian region. It has been showed, that HLA B-8 is present more frequently in sick children, than in healthy controls. The situation is reverse in case of HLA B-35 antigen. However, the difference is statistically insignificant. A probability of the lipid nephrosis sensitivity to corticosteroids can not be predicted on the base of the presence of these HLA antigens.     

Dexamethasone-induced selenoprotein S degradation is required for adipogenesis

Although adipogenesis is associated with induction of endoplasmic reticulum (ER) stress, the role of selenoprotein S (SEPS1), an ER resident selenoprotein known to regulate ER stress and ER-associated protein degradation, is unknown. We found an inverse relationship between SEPS1 level in adipose tissue and adiposity in mice. While SEPS1 expression was increased during adipogenesis, a markedly reduced SEPS1 protein level was found in the early phase of adipogenesis due to dexamethasone (DEX)-induced proteosomal degradation of SEPS1. Overexpression of SEPS1 in the early phase of cell differentiation resulted in impairment of adipogenesis with reduced levels of CCAAT/enhancer binding protein α and other adipocyte marker genes during the course of adipogenesis. Conversely, knockdown of SEPS1 resulted in the promotion of adipogenesis. Additionally, altered SEPS1 expression was associated with changes in expression of ER stress marker genes in the early phase of adipogenesis, and ubiquitin-proteasome system (UPS)-related ubiquitination and proteasome function. Our study reveals that SEPS1 is a novel anti-adipogenic selenoprotein that modulates ER stress- and UPS-dependent adipogenesis. Our results also identifies a novel function of DEX in the regulation of adipogenesis through induction of SEPS1 degradation. Taken together, DEX-dependent degradation of SEPS1 in the early phase of adipogenesis is necessary for initiating ER stress- and UPS-dependent maturation of adipocytes.     

Inverted patterns of genetic diversity in continental and island populations of the heather Erica scoparia s.l.

Aim Using the heather Erica scoparia s.l. as a model, this paper aims to test theoretical predictions that island populations are genetically less diverse than continental ones and to determine the extent to which island and continental populations are connected by pollen‐ and seed‐mediated gene flow. Location Macaronesia, Mediterranean, Atlantic fringe of Europe. Methods Patterns of genetic diversity are described based on variation at two chloroplast DNA (cpDNA) loci and one nuclear DNA (nDNA) locus for 109 accessions across the entire distribution range of the species. Global patterns of genetic differentiation were investigated using principal coordinates analysis. Genetic differentiation between island and continental areas, estimations of pollen‐ and seed‐mediated gene flow, and the presence of phylogeographical signal were assessed by means of F_st /N_ST (continental scale) and F_ij/N_ij (local scale). Extant and past distribution ranges of the species were inferred from niche modelling using layers describing present and Last Glacial Maximum (LGM) macroclimatic conditions. Results The Azores exhibited a significantly higher genetic diversity than the continent. The lowest levels of genetic differentiation were observed between the Azores and the western Mediterranean, and the diversity observed in the Azores resulted from at least two colonization waves. Within the Azores, kinship coefficients showed a significant and much steeper decrease with geographical distance in the cpDNA than in the nDNA. The distribution predicted by LGM models was markedly different from the current potential distribution, particularly in western Europe, where no suitable areas were predicted by LGM models, and along the Atlantic coast of the African continent, where LGM models predicted highly suitable climatic conditions. Main conclusions The higher diversity observed in Azorean than in continental populations is inconsistent with MacArthur and Wilson’s equilibrium model and derived theoretical population genetic expectations. This inverted pattern may be the result of extinction on the continent coupled with multiple island colonization events and subsequent allopatric diversification and lineage hybridization in the Azores. The results highlight the role of allopatric diversification in explaining diversification on islands and suggest that this process has played a much more significant role in shaping Azorean biodiversity than previously thought.