High incidence of arbuscular mycorrhizal fungi in rare and endangered wild grapevine

High levels of arbuscular mycorrhizal fungi colonisation of 90–100%, as well as high vesicular and arbuscular colonisation were found in the roots of the rare and endangered wild grapevine (Vitis vinifera subsp. sylvestris) along the Neretva River in southwestern Bosnia and Herzegovina, surpassing colonisation in region vineyads.     

Regiospecific alkaline protease-catalyzed divinyl acyl transesterifications of primary hydroxyl groups of mono- and di-saccharides in pyridine

This paper describes highly selective transesterification reactions, catalyzed by an alkaline protease from Bacillus subtilis in pyridine, of several mono- and di-saccharides with divinyl dicarboxylates ranging from 4 to 10 carbon atoms. A series of polymerizable vinyl fatty acid sugar esters were obtained with good selectivity and high yields. Most products had high proportions of the alpha anomer. The influences of the enzymes, solvents, temperature, and acyl donor chain length on the reaction were studied. Vinyl sugar esters offer a new family of functional water-soluble monomers for preparation of sugar-containing polymers.     

Biophysical studies on the differentiation of human CD14+ monocytes into dendritic cells

Dendritic cells (DCs), which are the most efficient antigen-presenting cells (APCs) currently known, can be derived from CD14⁺ monocytes (DC predecessor cells) in vitro. Immature DCs actively take up antigens and pathogens, generate major histocompatability complex-peptide complexes, and migrate from the sites of antigen acquisition to secondary lymphoid organs to become mature dendritic cells that interact with and stimulate T-lymphocytes. During this process, the cells must undergo deformation to translocate through several barriers, including the basement membrane and interstitial connective tissue in the blood vessel wall. To further understand the mechanisms of the activation of immunological responses and the migration from peripheral tissue to secondary lymphoid organs, we have applied biophysical and microrheological methods to study the development processes of DCs in vitro. The results showed that membrane fluidity, osmotic fragility, membrane viscoelastic properties, infrared spectroscopy, and cytoskeleton organization of DCs exhibit significant differences in different developmental stages. These authors contributed equally to this work.     

The Double-Water-Film Electrode: A Device for Measuring the Resistance and the Capacitance of the Internode/Node Interface of Chara as Functions of Time and Temperature

Abstract A ``double-water-film electrode technique' has been developed for the long-term characterization of the electrical properties across the interface between the nodal (N) and internodal (A or B) cells and the vacuole along the length of an internode of Chara as a function of time and temperature. The electrode unit consisted of a pair of the water-film electrodes described elsewhere (Chilcott 1988; Chilcott and others 1983; Coster and others 1984; Lucas 1985; and Ogata 1983). The distance between two water-film probes was fixed at 1.0 cm. By scanning the electrode unit, the spatial variations in electrical resistance and capacitance along the longitudinal axis of Chara were observed. Analysis was performed by applying an electrical equivalent circuit for the biomembrane (Philippson 1921). Across the internode (−A or −B)/central nodal cells interface, the specific parallel resistance (Rm) and the parallel capacitance (Cm) at 20°C were 30 ± 5 × 10⁻³Ωm² and 1.5 ± 0.5 × 10⁻¹Fm⁻² (at 30 Hz), respectively. And the series resistance, corresponding to the vacuole of the internode was 8 × 10⁻³Ωm². Study of temperature dependencies of Rm and Cm suggested that a dynamic homeostatic regulation was operating at the interface where numerous plasmodesmata were observed with an electron microscope (Pickett-Heaps 1967; Spanswick and Costerton 1967). Assuming that the individual cylinder of plasmodesma was filled only with cytoplasm, the number of plasmodesma per interface was estimated at 2.6 × 10⁵. Received 19 January 2000; accepted 16 March 2000     

Rheological and structural characterisation of film-forming solutions and biodegradable edible film made from kefiran as affected by various plasticizer types

The rheological properties of kefiran film-forming solutions, as well as the structural characterisation of the resulting films, were investigated as a function of various plasticizer types. The behaviours of the storage (G′) and loss (G″) moduli as a function of frequency were typical of gel-like material, with the G′ higher than the G″. Kefiran-based films, which may find application as edible films, were prepared by a casting and solvent-evaporation method. Possible interaction between the adjacent chains in the kefiran polymer and various plasticizers was proven by Fourier-transform infrared spectroscopy (FT-IR). The crystallinity of plasticized kefiran film was also analysed using X-ray diffraction (XRD); this revealed an amorphous-crystalline structure. These results were explained by the film's microstructure, which was analysed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The present study has helped determine possible interactions of kefiran, plasticizer and water molecules in determining film properties.     

Ontogeny of limb mass distribution in infant baboons (Papio cynocephalus)

Primates have more distally distributed limb muscle mass compared to most nonprimate mammals. The heavy distal limbs of primates are likely related to their strong manual and pedal grasping abilities, and interspecific differences in limb mass distributions among primates are correlated with the amount of time spent on arboreal supports. Within primate species, individuals at different developmental stages appear to differ in limb mass distribution patterns. For example infant macaques have more distally distributed limb mass at young ages. A shift from distal to proximal limb mass concentrations coincides with a shift from dependent travel (grasping their mother's hair) to independent locomotion. Because the functional demands placed on limbs may differ between taxa, understanding the ontogeny of limb mass distribution patterns is likely an essential element in interpreting the diversity of limb mass distribution patterns present in adult primates. This study examines changes in limb inertial properties during ontogeny in a longitudinal sample of infant baboons (Papio cynocephalus). The results of this study show that infant baboons undergo a transition from distal to proximal limb mass distribution patterns. This transition in limb mass distribution coincides with the transition from dependent to independent locomotion during infant development. Compared to more arboreal macaques, infant baboons undergo a faster transition to more proximal limb mass distribution patterns. These results suggest that functional demands placed on the limbs during ontogeny have a strong impact on the development of limb mass distribution patterns.     

Decreased protein tyrosine phosphorylation and membrane fluidity in spermatozoa from infertile men with varicocele

Varicocele is a prevalent pathology among infertile men. The mechanisms linking this condition to infertility, however, are poorly understood. Our previous work showed a relationship between sperm functional quality and the ability of spermatozoa to respond to capacitating conditions with increased membrane fluidity and protein tyrosine phosphorylation. Given the reported association between varicocele, oxidative stress, and sperm dysfunction, we hypothesized that spermatozoa from infertile patients with varicocele might have a combined defect at the level of membrane fluidity and protein tyrosine phosphorylation. Semen samples from infertile patients with and without grade II/III left varicocele were evaluated for motion parameters (computer-assisted semen analysis [CASA]), hyperactivation (CASA), incidence and intensity of protein tyrosine phosphorylation (phosphotyrosine immunofluorescence and western blotting), and membrane fluidity (Laurdan fluorometry), before and after a capacitating incubation (6 hr at 37 degrees C in Ham's F10/BSA, 5% CO(2)). Spermatozoa from varicocele samples presented a decreased response to the capacitating challenge, showing significantly lower motility, hyperactivation, incidence and intensity of tyrosine phosphorylation, and membrane fluidity. The findings reported in this article indicate that the sperm dysfunction associated to infertile varicocele coexists with decreased sperm plasma membrane fluidity and tyrosine phosphorylation. These deficiencies represent potential new pathophysiological mechanisms underlying varicocele-related infertility.     

Ultrasound-Assisted Extraction of Water-Soluble Polysaccharides from the Fruit of Acanthopanaxbrachypus: Physicochemical,Structural and Functional Properties

The ultrasound-assisted extraction (UAE) parameters of total water-soluble polysaccharides (TABPs) from Acanthopanaxbrachypus fruit were optimized by Box-Behnken design (BBD) and response surface methodology (RSM). Physicochemical, structural, and functional properties of TABPs were investigated by chemical analysis, inductively coupled plasma optical emission spectrometry (ICP-OES), high performance liquid chromatography (HPLC), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), water-holding capacity (WHC), oil-holding capacity (OHC), emulsion capacity (EC), emulsion stability (ES), as well as DPPH^. and ABTS^.+scavenging assays. The results showed that the maximal UAE-yield of TABPs was 3.81±0.18 % under the optimal conditions (ultrasonic power 325 W, extraction temperature 47 °C, extraction time 22 min). TABPs was rich in some beneficial element (Mg, K, Fe, Zn and Na) but little in harmful elements (Hg, Cd, As and Pb), and displayed rough surface with flake-like features and large dents, contained 93.89±0.08 % of total carbohydrate with more different monosaccharides including glucose, galactose, rhamnose, arabinose, mannose, xylose, and uronic acid in a molar ratio of 8.83 : 7.90 : 4.74 : 4.55 : 2.80 : 2.39 : 1.00, respectively. TABPs exhibited broad weight distribution (11.2–133.5 kDa), excellent thermal stability (>280 °C), WHC (0.61±0.08 g water/g sample) and OHC (4.53±0.12 g oil/g sample), as well as higher EC (43.75±1.23 %) and ES (38.32±1.50 %). Furthermore, TABPs also displayed remarkable scavenging activities on DPPH^. and ABTS^.+ in vitro. These findings provide a scientific basis for the applications of TABPs in functional additives for food, medicine, and cosmetics.     

Influence of support material properties on the potential selection of Archaea during initial adhesion of a methanogenic consortium

In anaerobic wastewater treatment systems, the complex microbial biomass including Archaea and Bacteria can be retained as a biofilm attached to solid supports. The aim of this study was to evaluate the impact of specific properties of support material on early microbial adhesion. Seven different substrata are described in terms of topography and surface energy. Adhesion of a methanogenic consortium to these substrata was tested, the adhesion was quantified as a percentage of the surface area covered and the bacterial and archaeal community structures was assessed by molecular fingerprinting profiles (CE-SSCP). As expected, the overall adhesion on the supports was influenced mainly by total surface energy. Moreover, the adhered communities were different from the parent inocula, including the Archaea/Bacteria ratio. This could have a significant impact on the start-up of anaerobic digesters for which supports favoring Archaea adhesion, responsible for the limiting reaction of the process, should be preferred.