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The production of levan by Bacillus licheniformis NS032 in a medium based on sugar beet molasses was studied. High polysaccharide yields were produced by using diluted molasses (100-140 g/L of total sugars) with the addition of commercial sucrose up to 200 g/L of total sugars, as well as K2HPO4. A levan yield of 53.2 g/L was obtained on a medium optimized by response surface methodology, containing 62.6% of sugar originating from molasses, and 4.66 g/L of phosphate, with initial pH value of 7.2. In comparison to the media with 200 and 400 g/L sucrose, in the molasses optimized medium, the observed bacterial growth was faster, while the maximum production of polysaccharide was achieved over a shorter time interval (48 h). The polysaccharide produced in molasses medium had a weight average molecular weight of 5.82 × 106 Da, degree of branching 12.68%, viscosity of 0.24 dL/g, and based on methylation analysis and NMR data, it did not significantly differ from levan obtained in the medium with 200 g/L sucrose.

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A clinoptilolite-based mixed matrix membrane (MMM) was developed and studied for the selective recovery of ammonium and potassium. Adsorption of sodium (Na(+)), potassium (K(+)) and ammonium (NH4(+)) was investigated with single salt and equimolar salt solution under static and dynamic conditions. Furthermore, the adsorption capacity of clinoptilolite was investigated when embedded in the MMM and in clay form. Two conditioning methods were compared: HCl and NaCl. Conditioned clinoptilolite with NaCl gave higher static adsorption capacities than with HCl which alters the chemical structure of clinoptilolite. The adsorption of Na(+) was not detected in the static adsorption experiments and results showed that Na(+) adsorbed during the conditioning process it was exchanged by K(+) and NH4(+).The clinoptilolite embedded in MMM reduced the porosity of the MMM so the highest adsorption capacity was reached when the amount of polymer was the lowest: 30 wt% polymer and 70 wt% clinoptilolite. The application of MMM in a dead-end filtration cell (dynamic adsorption) resulted in higher adsorption capacities compared to static conditions and comparable results between synthetic solutions and diluted urine samples. This indicates that MMM is a suitable method for the recovery of K(+) and NH4(+) directly from a diluted urine matrix. The desorption (recovery) of K(+) and NH4(+) from MMM was higher using water at 60 °C than using an acidic treatment.

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Amylose is able to form helical inclusion complexes with lysophosphatidylcholine (LPC). This complexation influences the functional and rheological properties of wheat starch; however it is well known that the formation of these complexes lead the starchy systems to a slower enzymatic hydrolysis. Based on this, to benefit from both the structuring properties of starch and also lower digestibility of the inclusion complexes, the objective of this study is the formation of amylose-LPC inclusion complexes while developing a firm network providing the desired functional properties in a starchy system. To investigate the influence of amylose-LPC complex formation at different stages of starch gelation on the viscosity behavior of wheat starch, 3% (w/w) LPC was added at three different points of the viscosity profile, obtained by rapid visco analyzer (RVA). LPC addition at all points affected the gelation behavior of wheat starch as compared with the reference. LPC addition at half-peak and peak of the viscosity profile resulted in a viscosity increase during cooling. Measuring the dynamic rheological properties of the freshly prepared gelatinized samples showed a decrease of storage modulus (G') and loss modulus (G") in the presence of LPC. During storage, in the presence of LPC, a lower elasticity was observed which indicates a lower rate of amylose retrogradation due to complexation with LPC.

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The enzymatic ring-opening copolymerization of ε-caprolactone (ε-CL) and ß-lactam by using Candida antarctica lipase B (CAL-B) as catalyst was studied. Variation of the feed ratios of 25:75, 50:50, and 75:25 of ε-CL/ß-lactam was performed. The products contain poly(ε-CL-co-ß-lactam) and the homopolymers of poly(ε-CL) and poly(ß-lactam). The structure of the copolymers was determined by MALDI-ToF MS. Poly(ε-CL-co-ß-lactam) has an alternating and random structure consisting of alternating repeating units with oligo(ε-CL) or oligo(ß-lactam). The highest fraction of the alternating copolymers resulted from the reaction with a feed ratio 50:50. The copolymer is a semicrystalline polymer with a Tm at 124 °C and Tgs at -15 and 50 °C. Interestingly, the copolymer also demonstrated cold crystallization at 29 and 74 °C, after quenching the sample from the melt in liquid nitrogen.

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Amylose forms inclusion complexes with lysophosphatidylcholine (LPC), that decrease the susceptibility of amylose to amylase degradation. This study on the influence of complexation on starch susceptibility to amylase explains the nature of this protective effect. Wheat starch suspensions (9% w/w) containing 0.5-5% LPC were subjected to hydrolysis by porcine pancreatic α-amylase at 37 °C for several digestion times. The digesta were analysed by size-exclusion chromatography (SEC). The molar mass distribution was closely dependent on the digestion time and amount of LPC. This study precisely demonstrates the alteration of the digestion profile of starch on a molecular level, influenced by amylose-LPC complexation; however the effect depends on the digestion time. During 15 and 30 min digestion, inclusion complexes not only protect amylopectin in the initial hydrolysis stage, but also demonstrate lower susceptibility of the molecular amylose complexes to amylase hydrolysis. Digestion for 240 min resulted in a lower oligosaccharide peak concentration, in the presence of a high LPC concentration, which is related to less degradation of complexed amylose fraction.

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This study was aimed to assess the role of lysophosphatidylcholine (LPC) in the development of slowly digestible starch (SDS). The influence of LPC, on the enzymatic degradation of diluted 9% wheat starch suspensions (w/w) was investigated, using an in vitro digestion method. Wheat starch suspensions containing 0.5-5% LPC (based on starch) were heated in a Rapid Visco Analyser (RVA) till 95 °C and subjected to enzyme hydrolysis by porcine pancreatic α-amylase at 37 °C for several digestion periods. In vitro digestion measurements demonstrated that complexing starch with 5% LPC leads to a 22% decrease in rate of reducing sugar compared to the reference while the samples containing 0.5% LPC showed an equal digestibility comparable to the control. A clear decrease in the formation of reducing sugars was observed in presence of 2-5% LPC, since the results after 15 min digestion imply the formation of SDS due to the formation of amylose-LPC inclusion complexes. The DSC measurements proved the presence of amylose-LPC inclusion complexes even after 240 min digestion demonstrating the low susceptibility of amylose-V complexes to amylase.

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Enzymatically catalyzed polycondensation of p-xylylenediamine and diethyl sebacate resulted in oligo(p-xylylene sebacamide) with high melting temperatures (223-230 °C) and the enzymatic polycondensation of dimethyl terephthalate and 1,8-diaminooctane leads to oligo(octamethylene terephthalamide) with two melting temperatures at 186 and 218 °C. No oligoamides, but products 1 and 2, were formed from the enzymatic reaction of dimethyl terephthalate and p-xylylenediamine. All reactions were catalyzed by CAL-B, icutinase, or CLEA cutinase. All reactions catalyzed by CAL-B show higher conversion than reactions catalyzed by icutinase or CLEA cutinase. The highest DPmax of 15 was achieved in a one-step and two-step synthesis of oligo(p-xylylene sebacamide) catalyzed by CLEA cutinase.

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Starch is an omnipresent constituent which is used for its nutritional and structuring properties. Recently concerns have been raised since starch is a source of readily available glucose which is tightly correlated with diabetes type II and obesity. For this reason, the possibilities for modulating the digestibility of starch while preserving its functional properties were investigated; therefore the focus of this paper is on starch gelatinization and the effect of lysophosphatidylcholine (LPC) on the structuring properties of wheat starch. The effect of LPC on thermal properties and viscosity behavior of starch suspensions was studied using DSC and RVA, respectively. The influence on granular structure was observed by light microscopy. The RVA profile demonstrated no viscosity increase at high LPC concentrations which proves intact granular structure after gelatinization. LPC in intermediate concentrations resulted in a notable delay of pasting; however the peak and end viscosities were influenced as well. Lower LPC concentrations demonstrated a higher peak viscosity as compared with pure starch suspensions. DSC results imply that inclusion complexes of amylose-LPC might be formed during pasting time. Since the viscosity profiles are changed by LPC addition, swelling power and solubility of starch granules are influenced as well. LPC hinders swelling power and solubility of starch granules which are stimulated by heating.

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The purpose of the present study was to determine the effect of progesterone or progesterone + estradiol-17beta on oxytocin-induced prostaglandin F2alpha (PGF2alpha) secretion in postpartum beef cows. Thirty-four anestrous postpartum beef cows were ovariectomized (d 32 [Groups 1 to 3] or d 23 [Groups 4 to 6] postpartum [d 0 = parturition]) and allotted to six treatments (Group 1; negative control) to simulate short (Groups 2 through 5) or normal (Group 6) length estrous cycles. Steroid treatments for the respective groups were as follows: Group 1) no estradiol-17beta or progesterone treatment (n = 8; negative control); Group 2) progesterone (d 34 to 40; n = 6); Group 3) estradiol-17beta (d 32 to 33) and progesterone (d 34 to 40; n = 6); Group 4) progesterone (d 23 to 29), no estradiol-17beta (d 32 to 33), and progesterone (d 34 to 40; n = 5); Group 5) progesterone (d 23 to 29), estradiol-17beta (d 32 to 33), and progesterone (d 34 to 40; n = 5); and Group 6) progesterone (d 23 to 29), estradiol-17beta (d 32 to 33), and progesterone (d 34 to 50; n = 4; positive control). Oxytocin (100 IU) was injected (i.v.) at the end of each treatment to test the ability of the postpartum uterus to secrete PGF2alpha as measured by a stable metabolite of PGF2alpha, 15keto-13,14 dihydro-PGF2alpha (PGFM). Peak concentrations ofPGFM (P < 0.08) and total PGFM secreted (area under the curve; P < 0.05) were increased on d 6 following first (Group 2) or second (Group 4) exposure to progesterone and were similar to peak concentrations and total PGFM secreted 16 d following a simulated normal estrous cycle (Group 6). Administration of estradiol-17beta before first progesterone exposure (Group 3) did not reduce peak concentrations of PGFM or total PGFM secreted relative to the preceding groups. Peak concentrations of PGFM (P < 0.08) and total PGFM secreted (P < 0.05) were reduced following a second progesterone exposure, provided that cows were pretreated with estradiol-17beta (Group 5). In summary, oxytocin-induced release of PGFM was inhibited on d 6 following second exposure to progesterone only when cows were pretreated with estradiol-17beta. Therefore, estradiol-17beta and progesterone were both associated with the timing of PGF2, secretion in postpartum cows.

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Mutant forms of recombinant ovine interferon-tau (oIFN-tau) have been previously prepared by site-directed mutagenesis of an ovine gene with the purpose of establishing relationships between structure and function of the molecule. These mutant forms have altered antiviral and antiproliferative activities, and receptor-binding affinities, and their ability to extend estrous cycle length after being injected i.m. into nonpregnant ewes has been established. In experiment 1, i.m. injection of either PBS (vehicle) alone or with 0.1 mg (n = 4), 0.5 mg (n = 4), or 2.0 mg (n = 3) of recombinant olFN-tau (S4, identified below) was performed twice daily on Days 11-18 postestrus (Day 0 = estrus). Luteal life span was extended (p < 0.05) by 4.8 days after injection of 0.5 mg or 2.0 mg oIFN-tau; injection of 0.1 mg had no effect (p > 0.05) on luteal life span relative to the group that received vehicle alone. In subsequent experiments, the dosage of oIFN-tau was 1.0 mg per injection twice daily. The objective of experiment 2 was to determine the effect of mutated forms of oIFN-tau on luteal life span in sheep. Fifty-seven ewes received twice-daily injections (i.m.) from Day 10 to Day 20 postestrus of PBS (vehicle) either alone (n = 9), with 0.3 mg/injection of bacterial contaminating proteins (BP; n = 10), or with 1 mg/injection of one of the following forms of recombinant oIFN-tau: 1) a fully active, 172-amino acid (aa) oIFN-tau (S4, n = 10); 2) a form lacking 11 aa at the carboxyl terminus and with an I143-->T mutation (S1), which had very low antiviral and antiproliferative activities and receptor-binding affinities (n = 9); 3) a truncated form identical to S1 but with I143 restored (TRN11), which had low antiviral and antiproliferative activities but only slightly reduced receptor-binding affinities (n = 10); and 4) a form similar to wild type S4 (S4-K) with low antiviral and antiproliferative activities but only slightly reduced receptor-binding affinities (n = 9). Luteal life span was slightly longer (p < 0.05) in the TRN11 and S4-K groups (19.6 and 20.6 days, respectively) than in the PBS, BP, and S1 groups (16.2, 16.8, and 17.5 days, respectively). In the S4 group, mean luteal life span was 33.6 +/- 5.9 days (range 15.5-64 days). A third experiment entailing twice-daily injections of either 0.3 mg BP (n = 6), 1 mg TRN11 (n = 5), 1 mg S4-K (n = 5), or 1 mg S4 (n = 5) was conducted in which the pyrogenic effect of the oIFN-tau was also examined. Luteal life span was longer (p < 0.05) in the S4-K and S4 groups (18.9 and 28 days, respectively) than in the BP and TRN11 groups (16.6 and 17.6 days, respectively). Intramuscular injection of all forms of IFN-tau caused hyperthermia in ewes initially, but ewes appeared to become refractory to treatment after several days. In summary, extension of luteal life span was more closely associated with biological activity as assessed in vitro than with receptor binding affinities.

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Designing and implementing an infection control program for home care poses many challenges. Some of these challenges stem from a long-standing lack of research and on-site expertise in the home care setting. Recent changes in health care and the proliferation of external regulations regarding home care practice further complicate the development of an effective and efficient infection control program.

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It is generally accepted that ovarian follicular cysts (cysts) are nonovulatory follicular structures that contribute to extended calving intervals. Follicle/cyst dynamics and the etiology of cysts are unclear. The present study was conducted to characterize follicle/cyst dynamics and to define endocrine changes (etiology) associated with cyst development. Thirty-two dairy cows were studied: controls (n = 6), cows with spontaneously occurring cysts (n = 14), and cows in which cysts were induced by exogenous steroid treatment (n = 12). Ovaries of cows were scanned daily by ultrasonography to record follicle/cyst dynamics. Blood was collected to determine endocrine changes associated with follicle/cyst life span. Three ovarian responses in cows with cysts were observed: persistence of cysts, turnover of cysts, or spontaneous recovery (self-recovered; turnover of cysts and replacement with a follicle that ovulated). Mean maximum size of cysts was larger (p < 0.05) than that of ovulatory follicles (2.80 +/- 0.19 vs. 1.60 +/- 0.05 cm). Mean interval from initial detection of follicle/cyst wave to detection of a new follicle/cyst wave in cows with cysts was longer (13.0 +/- 1.1 days; p < 0.05) and more variable (6 to 26 days; p < 0.05) than in controls (8.5 +/- 0.5 days and 6-14 days, respectively). Cysts grew at the same rate as follicles but continued to grow for an additional period of time. A transient increase in FSH preceded detection of all follicle/cyst waves.(ABSTRACT TRUNCATED AT 250 WORDS)

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Extract prepared from activated Xenopus eggs is capable of reconstituting nuclei from added DNA or chromatin. We have incubated such extract in the absence of DNA and found that numerous flattened membrane cisternae containing densely spaced pore complexes (annulate lamellae) formed de novo. By electron and immunofluorescence microscopy employing a pore complex-specific antibody we followed their appearance in the extract. Annulate lamellae were first detectable at a 30-min incubation in the form of short cisternae which already contained a high pore density. At 90-120 min they were abundantly present and formed large multilamellar stacks. The kinetics of annulate lamellae assembly were identical to that of nuclear envelope formation after addition of DNA to the extract. However, in the presence of DNA or chromatin, i.e., under conditions promoting the assembly of nuclear envelopes, annulate lamellae formation was considerably reduced and, at sufficiently high chromatin concentrations, completely inhibited. Incubation of the extract with antibodies to lamin LIII did not interfere with annulate lamellae assembly, whereas in the presence of DNA formation of nuclear envelopes around chromatin was inhibited. Our data show that nuclear membrane vesicles are able to fuse spontaneously into membrane cisternae and to assemble pore complexes independently of interactions with chromatin and a lamina. We propose that nuclear envelope precursor material will assemble into a nuclear envelope when chromatin is available for binding the membrane vesicles, and into annulate lamellae when chromatin is absent or its binding sites are saturated.

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We analysed the soluble form in which the nuclear pore complex protein p68 is stored in Xenopus laevis eggs and its involvement in pore complex assembly processes. We have shown previously that p68, which is the major wheat germ agglutinin (WGA)-binding glycoprotein of nuclear pore complexes from Xenopus oocytes, is located in the pore channel and participates in mediated transport of karyophilic proteins. Using a monoclonal antibody directed against p68 (PI1) we removed this protein from Xenopus egg extract by immunoadsorption. On addition of lambda DNA the immuno-depleted extract supported reconstitution of nuclei which were surrounded by a continuous double-membrane envelope but lacked pore complexes and were unable to import karyophilic proteins such as nucleoplasmin or lamin LIII. Essentially identical results were obtained with extract depleted of WGA-binding proteins. Our finding that both the anti-p68 antibody and WGA efficiently removed components from the extract necessary for pore complex assembly but did not interfere with nuclear membrane formation demonstrates that these processes are independent of each other. Analysis of the immunoprecipitate on silver-stained SDS-polyacrylamide gels indicated that the antibody adsorbed other proteins besides p68, notably two high molecular weight components. By sucrose gradient centrifugation and gel filtration we showed that p68 together with associated protein(s) forms a stable, approximately globular complex with an Mr of 254,000, a Stokes radius of 5.2 nm and a sedimentation coefficient of 11.3 S. Our finding that p68 occurs in the form of larger macromolecular assemblies offers an explanation for the distinctly punctate immunofluorescence pattern observed in the cytoplasm of mitotic cells after staining with antibodies to p68.

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