Projektet har inriktning på Galdermas produkter Deflux och Solesta, de ämnen som produkterna är uppbyggda av (dextran och hyaluronsyra) har studerats laborativt. Ändringar av parametrar såsom koncentration av dextran men även i siktningsmetod (dubbel- respektive enkelsiktningar samt olika filterstorlekar) har genomförts. Resultatet av dessa ändringar har erhållits med hjälp av mikroskop, laserdiffraktometer samt dragprovare. De slutsatser som har kunnat dras från resultaten är att med ökad partikeldiameter erhålls en lägre extruderingskraft, oavsett om använd siktningsmetod var enkel- eller dubbelsiktning. Vidare så erhålls en större extruderingskraft med ökad koncentration av dextran.

Projektet har inriktning på Galdermas produkter Deflux och Solesta, de ämnen som produkterna är uppbyggda av (dextran och hyaluronsyra) har studerats laborativt. Ändringar av parametrar såsom koncentration av dextran men även i siktningsmetod (dubbel- respektive enkelsiktningar samt olika filterstorlekar) har genomförts. Resultatet av dessa ändringar har erhållits med hjälp av mikroskop, laserdiffraktometer samt dragprovare. De slutsatser som har kunnat dras från resultaten är att med ökad partikeldiameter erhålls en lägre extruderingskraft, oavsett om använd siktningsmetod var enkel- eller dubbelsiktning. Vidare så erhålls en större extruderingskraft med ökad koncentration av dextran.

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Cryopreservation is a process where a sample, e.g. cells or tissue, is preserved by cooling to sub-zero temperatures, usually -196°C. Upon freezing these materials, ice crystals form, which eventually results in cell death. In order to reduce the formation of ice crystals, cryoprotectants are added to the storage solution. Current cryoprotective agents have several weaknesses, making the development of cryoprotective agents with advanced properties of great interest. In this study, two possible non-penetrating cryoprotectants termed Dextran Sulphate Sodium Salt 80 (DSSS 80) and Dextran Sulphate Sodium Salt (DSSS 140), were developed. The cryopreservative effect of DSSS 80 and DSSS 140 was studied on human spermatozoa regarding cryorecovery, using a simple cryopreservation procedure. Moreover, the new compound’s cryoprotective properties were compared to conventional types of dextrans, which in previous studies have proven effective. The percentage of sperm motility was assayed before freezing by the optical microscopic method using a haemocytometer as counter chamber. After thawing, the cells were stained with trypan blue and post-thaw motility was determined. It was found that all sperm cells lost their motility, regardless cryoprotectant, concentration or in the absence of dextrans, which indicated that the applied cryopreservation was unfitting. Thus, since the method used in study was not optimal for cryopreservation of sperm cells, it was not possible to determine whether DSSS 80 or DSSS 140 display cryoprotective properties or not, nor if they are superior to conventional types of cryoprotectants.

Osteopontin (OPN) is a matricellular cytokine found in most tissues and body fluids. It is involved in a variety of cell processes by binding to integrins and CD44 receptors, and it modulates immune responses. To investigate the functions of OPN during colitis the DSS acute colitis model in OPN-/- and WT control mice was utilized. OPN-/- mice were more susceptible to DSS-induced colitis than the DSS-treated WT control mice. The increased susceptibility of the OPN-/- mice was characterized by greater intestinal crypt destruction; high myeloperoxidase activity of infiltrating neutrophils; lack of differentiation of inflammatory cells such as lymphocytes subsets (CD4+, CD8+) and macrophages (F4/80); reduced production of certain cytokines, especially TNF-alpha; and non-programmed cell death of enterocytes. It is postulated that the hyperactivity of neutrophils may explain the increased tissue destruction during experimental colitis in the absence of OPN. Analysis of OPN’s impact on neutrophil function showed that while OPN may be important for the recruitment and migration of neutrophils, the expression of OPN by neutrophils is not required for manifestation of their destructive capabilities. This would suggest that OPN administration may protect the intestines from the adverse effects of colitis. Exogenous bovine milk OPN (20 μg/ml), administered for 8 days dissolved in the drinking water, ameliorated DSS-induced colitis. It diminished signs of disease, with a greater impact in the WT than the OPN-/- mice. It reduced the levels of neutrophils, macrophages, and pro-inflammatory mediators in the colon tissue. Recombinant OPN failed to reproduce the beneficial effects of milk OPN, which suggests that post-translational modifications of OPN are crucial to ameliorate experimental colitis. Collectively, these studies demonstrate that OPN has a protective effect during experimental colitis and that the oral administration of bovine milk OPN (20 μg/ml) ameliorates acute DSS-induced colitis. The results of this study also imply that the protective effect probably depends on a post-translationally modified form of OPN, and may require intracellular-OPN as a cofactor for significant attenuation of colitis. Future research could concentrate on more detailed investigation of these latter findings to determine OPN’s mechanism of action.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Absence of stearoyl-CoA desaturase-1 (SCD1) in mice leads to chronic inflammation of the skin and increased susceptibility to atherosclerosis, while also increasing plasma inflammatory markers. A recent report suggested that SCD1 deficiency also increases disease severity in a mouse model of inflammatory bowel disease, induced by dextran sulfate sodium (DSS). However, SCD1-deficient mice are known to consume increased amounts of water, which would also be expected to increase the intake of DSS-treated water. The aim of this study was to determine the effect of SCD1 deficiency on DSS-induced acute colitis with DSS dosing adjusted to account for genotype differences in fluid consumption. Wild-type controls were treated with 3.5% DSS for 5 days to induce moderately severe colitis, while the concentration of DSS given to SCD1-deficient mice was lowered to 2.5% to control for increased fluid consumption. Colonic inflammation was assessed by clinical and histological scoring. Although SCD1-deficient mice consumed a total intake of DSS that was greater than that of wild-type controls, colonic inflammation, colon length and fecal blood were not altered by SCD1-deficiency in DSS-induced colitis, while diarrhea and total weight loss were modestly improved. Despite SCD1 deficiency leading to chronic inflammation of the skin and increased susceptibility to atherosclerosis, it does not accelerate inflammation in the DSS-induced model of acute colitis when DSS intake is controlled. These observations suggest that SCD1 deficiency does not play a significant role in colonic inflammation in this model. [The original version of this article, along with updated information and services is located on the World Wide Web at: http://dx.doi.org/10.1016/j.bbalip.2009.08.001]

Osteopontin (OPN) is a matricellular cytokine found in most tissues and body fluids. It is involved in a variety of cell processes by binding to integrins and CD44 receptors, and it modulates immune responses. To investigate the functions of OPN during colitis the DSS acute colitis model in OPN-/- and WT control mice was utilized. OPN-/- mice were more susceptible to DSS-induced colitis than the DSS-treated WT control mice. The increased susceptibility of the OPN-/- mice was characterized by greater intestinal crypt destruction; high myeloperoxidase activity of infiltrating neutrophils; lack of differentiation of inflammatory cells such as lymphocytes subsets (CD4+, CD8+) and macrophages (F4/80); reduced production of certain cytokines, especially TNF-alpha; and non-programmed cell death of enterocytes. It is postulated that the hyperactivity of neutrophils may explain the increased tissue destruction during experimental colitis in the absence of OPN. Analysis of OPN’s impact on neutrophil function showed that while OPN may be important for the recruitment and migration of neutrophils, the expression of OPN by neutrophils is not required for manifestation of their destructive capabilities. This would suggest that OPN administration may protect the intestines from the adverse effects of colitis. Exogenous bovine milk OPN (20 μg/ml), administered for 8 days dissolved in the drinking water, ameliorated DSS-induced colitis. It diminished signs of disease, with a greater impact in the WT than the OPN-/- mice. It reduced the levels of neutrophils, macrophages, and pro-inflammatory mediators in the colon tissue. Recombinant OPN failed to reproduce the beneficial effects of milk OPN, which suggests that post-translational modifications of OPN are crucial to ameliorate experimental colitis. Collectively, these studies demonstrate that OPN has a protective effect during experimental colitis and that the oral administration of bovine milk OPN (20 μg/ml) ameliorates acute DSS-induced colitis. The results of this study also imply that the protective effect probably depends on a post-translationally modified form of OPN, and may require intracellular-OPN as a cofactor for significant attenuation of colitis. Future research could concentrate on more detailed investigation of these latter findings to determine OPN’s mechanism of action.

Sulfuric acid hydrolysis of native cellulose fibers produces stable suspensions of cellulose nanocrystals. Within a specific concentration range, the suspensions spontaneously form an anisotropic chiral nematic liquid crystal phase. This thesis examines the phase separation behaviour of these suspensions, alone and in the presence of added macromolecules. Initially, the effect of hydrolysis conditions on the nanocrystal and phase separation properties for hydrolyzed softwood pulp were investigated and compared to suspensions prepared from hardwood pulp. The macromolecules studied, blue dextrans of varying molecular weights and dye ligand densities, were synthesized and characterized with a number of techniques. The polyelectrolytic nature of these macromolecules was found to strongly influence their physico-chemical properties. Added blue dextran causes separation of an isotropic phase from highly concentrated, completely anisotropic suspensions. The observed phase separation was found to be associated with the charged dye molecules attached to the dextran. The partitioning behaviour of blue dextrans in biphasic aqueous suspensions of native cellulose nanocrystals was also studied with regard to the effect of total concentration of blue dextran, degree of dye substitution and dextran molecular weight on the blue dextran partition coefficient. Electrostatic and entropic contributions to the partition coefficient of blue dextran were discussed. Triphase isotropic-isotropic-nematic (I1--I 2--N) equilibria are observed in suspensions containing both neutral dextrans and polyelectrolytic blue dextrans of varying molecular weight. Based on these results, phase diagrams for cellulose nanocrystal suspensions with different combinations of dextran and blue dextran are presented.

The thesis focuses on the determination of dextran presence and its potential amount in sugar made semi-products. Dextran is a polysaccharide which is created on a sugar beet tuber due to inappropriate storing, because of low temperatures or wound of beet tissue, which is subsequently prone to infections caused by Leuconostoc mesenteroides microorganism. The infection results in creation of polysaccharides and other secondary products which have a negative influence on technological processing of beet. Levan and dextran create the highest amount of these polysaccharides in sugar beet. They significantly increase the viscosity of sugar juice. It is subsequently seen on crystallization of calcium carbonate during the second saturation and this causes the deterioration of filterability. In case of dextran or other polysaccharides presence other problems arise in the technological process of sugar production. For its elimination enzymatic hydrolysis is used with the aid of dextranase or alfa amylase. This element splits dextran polysaccharide into smaller oligosaccharids which are not caught in filtration device and therefore do not cause reduction in production capacity. Commercially accessible dextranase; however, is financially demanding so that there are researches trying to find more economical ways. This diploma thesis evaluates the presence of dextran in extracted juice by means of ICUMSA GS8-19 (year 2009). The method evaluates the presence of dextran in diffused, heavy and II. saturated juice. The research was focused on determination of alkalinity, pH, sedimentation and filtration coefficient, polarization, sugar content and purity. The aim of this thesis is to evaluate the correlation between recorded numbers and the application of the two enzymes which are used for removal of these problems. After completion of the experiment and evaluation of measured results in operating laboratory of sugar factory Tereos TTD Dobrovice, connection among laboratory measured data was not proved. Our recorded data did not prove reciprocal relation. The only proved connection was about number of rinsed filters (per day) after II. saturation and amount of used enzymes. The amount of enzymes influences how many times per day filters must be rinsed in order to get rid of deposit. In case of high amount of dextran, filters started to be clogged by impervious layer of molecules and in case that enzymatic way was not used for elimination of this saccharide, the only solution was frequent filters rinsing or reduction in working capacity connected to subsequent prolongation of processing campaign. Further, we proved the efficiency of alfa amylase which was used during beet processing (after New Year). This enzyme had the same impact on elimination of polysaccharides and clearance of filters. It is to say that in following campaigns it is possible to substitute financially demanding enzyme for cheaper alfa amylase.