Objectives: In this pilot study, our intention was to ascertain what formulation of a carbohydrate-derived fulvic acid (CHD-FA) topical applicator was optimal for patients to use during a larger study where the efficacy of fulvic acid (CHD-FA) in treating moderate acne vulgaris will be investigated. Methods: 15 individuals with inflammatory acne with an acne grade of III or lower were asked to volunteer for the study. They were split into 3 groups. Each group was asked to use a different formulation (a cream base, gel base and wet applicator formulation) each week. After each week, the individuals returned to fill out a questionnaire evaluating the formulation they used that week. They were also examined by the clinician for any possible side effects, and given the next formulation to use for the following week. The trial was 3 weeks long, and after using all 3 formulations the individuals were asked to fill out a final questionnaire evaluating all 3 formulations. The clinician was also asked to fill out a questionnaire giving his/her opinion on the formulations. Results: The results did not give conclusive evidence of one particular formulation being favored above all the others. All the formulations performed more or less equally as well. According to the final questionnaire, 6 out of the 15 individuals were most satisfied with the wet applicator, 4 out of 15 preferred the cream base and 5 out of 15 preferred the gel base. 5 out of 15 individuals were least satisfied with the wet applicator, 3 out of 15 with the cream base, and 7 out of 15 were least satisfied with the gel. While there was no conclusive indication for one particular formulation, there were some common complaints or observations by individuals about each formulation. Most individuals said the wet applicator had an initial burning sensation to the skin upon application, but it disappeared a few seconds after application. Many individuals said they felt the cream base was oily and made the skin appear oily after application. The gel base was said to smell the worst, along with the wet applicator, while the cream smelt the least. A few individuals complained that the gel left a residue on the skin. Conclusion: While the study did not give a clear indication of one particular formulation that was preferred by individuals, it did produce interesting results that can be used to make some of the formulations more favourable. In the main trial, further investigation will be done to optimize the formulation. / Dissertation (MSc)--University of Pretoria, 2010. / Pharmacology / unrestricted

Endurance athletes have long benefited from ingesting carbohydrates prior to, and during endurance events. Fatigue during endurance exercise has repeatedly been associated with the depletion, or reduction, of bodily carbohydrate reserves. The improved endurance capability observed after aerobic training has, however, been attributed to the increased oxidation of fat relative to carbohydrate, thereby having a 'carbohydrate sparing" effect and thus delaying the point at which reduced carbohydrate reserves will cause fatigue. This study was therefore designed to investigate the effects of medium-chain triglyceride (MCT) and carbohydrate (CHO) supplementation, on the performance and metabolic parameters of nine male marathon athletes. These results were then statistically compared to the effects of adding L-carnitine to the MCT and CHO supplement, on the same parameters. Metabolic parameters included nutritional status evaluations, serum organic acid profiles (non-esterified fatty acid and L-lactate profiles), and plasma carnitine determinations. Performance was measured in terms of peak treadmill running speed, V02 max, respiratory exchange ratios, heart rates, vco2 and vo2 data during progressive treadmill exercise tests. Nutrition and energy intakes were recorded during the study, as well as record kept of the athlete's training programmes. At the end of each supplementation period, a standard marathon was included in the experimental design, in order to practically validate controlled laboratory results. The main findings of this study included the identification of two athletes as 'fat burners'~ Non-esterified fatty acid (NEFA) profiles indicated that they predominantly relied on fatty acid oxidation during exercise, after MCT supplementation. The latter presumably because of adaptive changes in their metabolism, enabling them to benefit from MCT supplementation. In spite of the majority of athletes relying on carbohydrate metabolism during exercise, the addition of L-carnitine to the MCT and CHO supplement, induced a shift towards lipid metabolism; evident from RER and VC02 data, as well as the majority of athletes improving their performance. The observed shift was slight; the latter being ascribed to the relatively small dose of L-carnitine (compared to previous studies) included in the supplement. However, L-carnitine was incorporated into a palatable, liquid MCT and CHO supplement, and not merely administered in the form of a pharmacological dose. A major, and extremely unexpected finding, was the presumed effect that the winter, and continuous cold exposure, had on plasma carnitine levels. Plasma carnitine levels decreased significantly, without any intervention, prior to the start of the second trial period, which stretched over the middle of winter. Despite carnitine supplementation, plasma carnitine levels still decreased. This occurrence most certainly influenced results; the shift towards lipid metabolism would presumably have been more pronounced, had the 'Winter factor' not come into play. / Dissertation (MSc)--University of Pretoria, 2012. / Physiology / unrestricted

When provided with the opportunity to select their diet, most insect herbivores regulate their nutrient intake. However, in a nutritionally heterogeneous environment and with changing demands for growth, development and reproduction, obtaining the required amount and balance of nutrients is a challenge. This is especially true for social insects where the workers bring food into the colony to be shared by nestmates. The ability of insects to self-select their diet is an important trait related to fitness. In this study we investigated whether and how caged worker honeybees meet their nutritional requirements in response to the nutritional composition of the food they find. Using the ‘geometric framework’ we looked at the behavioural and physiological mechanisms used by caged worker honeybees in balancing their diet when provided with different pairs of complementary imbalanced foods. First, we investigated whether caged worker honeybees maintain their intake target by providing them with pairs of complementary imbalanced foods with varying protein to carbohydrate (P:C) ratios. Diets were formulated using different protein sources: casein, royal jelly and Feed-Bee®. Honeybees self-selected or balanced their diet by switching between the complementary foods in accordance with the composition of the food and the type of protein that they encountered. Honeybees selected average P:C ratios of 1:12, 1:14 and 1:11 on casein, royal jelly and Feed-Bee® diets respectively. The level of self-selection was confirmed using two performance measures: survival and ovarian activation. Both survival and ovarian activation differed depending on the type of protein source used. Second, we investigated if honeybees regulated their growth target, which is the amount of nutrients incorporated into growth and storage tissue, by measuring physiological parameters in honeybees confined on imbalanced complementary food combinations having different P:C ratios. Feed-Bee® was used as a protein source. The physiological parameters measured were head fresh mass, hypopharyngeal gland (HPG) development, and protein concentration in the haemolymph. The bees fed on different diet combinations with different P:C ratios maintained each of the performance measures to the same level, which supports the ability of worker honeybees to self-select their diet. The measured physiological parameters were compared with other studies to asses the appropriateness Feed-Bee® diet as a protein source for the bees. In the absence of brood the intake target is directly related to the physiological requirements of the worker bees. The behavior of these individual adult bees gives an insight in to the complex system; similar responses may be seen in nurse bees in the colony condition to obtain protein, carbohydrate and other nutrient requirements from stored pollen and nectar in the hive, either for their own nutritional requirements or for other colony members, especially larvae. / Dissertation (MScAgric)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted

High training loads or prolonged bouts of acute exercise can increase susceptibility to opportunistic infections. Such infections, although generally medically innocuous, can have profound negative implications for athletic performance. This thesis presents a series of studies investigating which factors influence infection risk in athletes, as well as exploring potential strategies to maintain immunocompetence during heavy training. In Chapters 2 and 3, a large cohort of elite winter endurance athletes were followed over a number of years to determine patterns and frequency of illness in this population, and to identify training- and competition-related predictors of infection. Incidence rates and seasonal patterns of illness were found to be broadly similar to elite athletes from summer sports, and to the general population. Competition, air travel, greater day-to-day fluctuations in training load and lower performance level were significant predictors of illness. When high training loads are combined with insufficient recovery, athletes may become overreached or overtrained. Previous studies suggest that increasing carbohydrate intake can be an effective means of preventing overreaching during periods of intense training. In Chapter 4 we therefore investigated the efficacy of carbohydrate supplementation in reducing immune disturbances and symptoms of overreaching. The lower carbohydrate does (20 g/h during exercise) was found to be equally effective in preserving immunity and power output as the higher dose (60 g/h), with modest immune and performance changes observed in both groups following eight days of intensified training. Many athletes fail to ingest sufficient fluid to maintain euhydration during exercise. However, Chapter 5 found that moderate hypohydration, elicited by a 24 h period of fluid restriction, had little effect on immune responses to prolonged exercise. Altitude training is an important component of the training process of most of today s elite endurance athletes. Chapters 6 and 7 explored the effects of acute and prolonged hypoxic training on immunity. Despite a somewhat augmented stress hormone response to exercise in hypoxia, altitude training was found to have little negative effect on host defence, providing relative exercise intensity at altitude and sea-level was matched.

No description available.

Inhibiting the formation of ice is an essential process commercially, industrially, and medically. Compounds that work to stop the formation of ice have historically possessed drawbacks such as toxicity or prohibitively high active concentrations. One class of molecules, ice recrystallization inhibitors, work to reduce the damage caused by the combination of small ice crystals into larger ones. Recent advances made by the Ben lab have identified small molecule carbohydrate analogues that are highly active in the field of ice recrystallization and have potential in the cryopreservation of living tissue. A similar class of molecules, kinetic hydrate inhibitors, work to prevent the formation of another type of ice – gas hydrate. Gas hydrates are formed by the encapsulation of a molecule of a hydrocarbon inside a growing ice crystal. These compounds become problematic in high pressure and low temperature areas where methane is present - such as an oil pipeline. A recent study has highlighted the effects of antifreeze glycoprotein, a biological ice recrystallization inhibitor, in the inhibition of methane clathrates. Connecting these two fields through the synthesis and testing of small molecule ice recrystallization inhibitors in the inhibition of methane hydrates is unprecedented and may lead to a novel class of compounds.

Les lectines spécifiques du rhamnose ont été découvertes comme nouvelle classe de lectines dans les années 1990. La plupart de ces lectines a été isolée à partir d'animaux aquatiques. Des récepteurs spécifiques du rhamnose sur les kératinocytes ont été découverts en 1991 quand les reconnaissances entre des glycoprotéines synthétiques incorporées dans des liposomes et des kératinocytes ont été étudiées. Nous avons synthétisé des nouveaux dérivés de rhamnose à cibler ces lectines. / Rhamnose binding lectines were discovered as new class of lectines in 1990's. Most of these lectines has been isolated from aquatic animals. It was discovered in 1991 that rhamnose specific receptors may be present in human skin while studying the interaction between liposomes incorating synthesitic glycoproteins and keratinocytes. We have synthesized new derivatives of rhamnose to target these lectines.

When inhaled, bioaerosols exacerbate respiratory symptoms and diseases. Mitigating the negative health impacts of bioaerosols requires a robust understanding of the temporal and spatial dynamics of bioaerosols in the atmosphere as a function of their type (e.g., bacteria, fungal spores, plant pollens) and particle size, which determines their penetration into the respiratory tract. While it is known that bioaerosol concentrations vary by location, season and meteorological conditions, major gaps remain in understanding the co-occurrence of bioaerosols with one another, their size in the atmosphere, and their mass contributions to PM. Overall, research presented in this thesis advances the current knowledge about bioaerosols (including fungal spores, pollens, and bacteria) in following ways: 1) defining background and urban levels of bioaerosol concentrations in the Midwestern US across four seasons, 2) characterizing ambient bioaerosol and co-pollutant mixtures, 3) determining the influence of meteorology on their concentrations and size distributions, and 4) estimating bioaerosol contributions to PM mass. The spatial analysis of respirable particulate matter (PM10) across urban and background sites in Iowa demonstrated that urban areas are a source of fungal glucans, bacterial endotoxins and total proteins, which gives rise to significantly enhanced bioaerosols in urban locations compared to background sites. Similar urban enhancements in calcium—a crustal element—and its correlation with endotoxins suggested that wind-blown soil is likely the origin. Seasonally, fungal spores peaked in summer with temperature, while bacterial endotoxins peaked in autumn during the row crop harvesting season. Fungal spores, bacterial endotoxins, plant and animal detritus all peaked during the growing season, such that maximum exposures to multiple bioaerosol types concurrently. Under the influence of rain chemical tracers of pollens peaked and decreased in size from coarse (2.5-10 µm) to fine particles (< 2.5 µm), likely due to the osmotic rupture of pollen grains upon wetting. While fine-sized fungal spores also increased during rain events, maximum spore levels were observed in coarse-sized particles post-rain. The comparison of spring to late summer measurements demonstrated these influences of precipitation on bioaerosols also occur during late summer, when fungal spore levels are high and ragweed is the dominant pollen source. The ability to apportion PM mass to bioaerosols was advanced through the development of chemical profiles of pollens and their integration with chemical mass balance (CMB) source apportionment modeling, for the first time. In late-April to early-May in 2013, pollens were estimated to contribute 0.2 - 38% of PM₁₀ (0.04 – 0.8 µg m⁻³) while fungal spores contributed 0.7 – 17% of PM₁₀ (0.1 – 1.5 µg m⁻³). Collectively, this thesis provides insight into spatial, seasonal and daily variations of bioaerosols, and shows elevated outdoor exposures to bioaerosols among urban populations, with maximum levels occurring during growing seasons, periods of high temperature, and during/immediately following rainfall.

In this thesis, we report on our studies of water dynamics and structure in various biological environments which include: the surfaces of proteins and various oligosaccharides, the intervening space between proteins; and in the vicinity of cryoprotectant disaccharides in the liquid and ice phases. From a theoretical perspective, we propose methodology to compute diffusivity and residence times on the surface of biomolecules. In particular our proposed algorithm to compute residence times appears to be better in dealing with poor statistics associated with the number of water molecules that remain on a surfaces for extended times. The type of linkage between monomers and the anomeric configuration all play a major role in determining the structure and dynamics of water on the surface of carbohydrates.

The transformation from normal to malignant phenotype in human cancers is associated with aberrant cell-surface glycosylation. Mucin 1 (MUC1), the heavily glycosylated cell-surface mucin, is altered in both, expression and glycosylation pattern in many cancers. The presence of truncated glycan structures, often capped by sialic acid, commonly known as tumor-associated carbohydrate antigens (TACAs), play key roles in tumor initiations, progression, and metastasis. Accumulating evidence suggests that expression of TACAs is associated with escape of immune defenses. Human macrophage galactose-type lectin (hMGL, HML, CD301 or CLEC10A), a C-type lectin expressed by antigen presenting cells (APC), is a receptor of mucin-type TACAs, -GalNAc (Thomsen nouvelle antigen; Tn; CD175) and its 2,6-sialylated derivative (sTn; CD175s). To date, the relative contributions of these glycans, as well as underlying peptide backbone, and different degrees of valency, on binding thermodynamics and kinetics with hMGL remains elusive. In order to discern the subtle utility of these distinct features, chemical syntheses of the MUC1, HGVTSAPDTRPAPGSTAPPA tandem repeat sequence, and its site-specific serine (Ser) and threonine (Thr) glycosylated analogs were carried out. Circular dichroism (CD) spectroscopy experiments detected increasing structural order of the Thr glycopeptides compared to its nonglycosylated analogs. Isothermal titration calorimetry (ITC) data analysis of lectin binding to the Thr glycopeptides invariably showed enthalpy-driven processes. Affinity enhancement of the Thr glycopeptides for hMGL occurred relative to free GalNAc, revealing an increasing trend in affinity by one order of magnitude, for mono- (KD = 6-8 μM) to triglycosylated (KD = 600 nM) MUC1 peptides. To delineate the relevance of the solvent structure in the protein carbohydrate recognition process, experiments in D2O were performed, exposing enthalpy-entropy compensation differences. KinITC analysis highlighted prolonged complex lifetimes. Furthermore, atomic force microscopy (AFM) based dynamic single-molecule force spectroscopy (SMFS) provided molecular level insight into the energy landscapes governing recognition of the MUC1(Tn)-hMGL complexes. In summary, our results suggest that contact with hMGL critically depends on the type of TACA, nature of the vicinity surrounding the glycan, and its density. This highlights the importance and current efforts in design of prophylactic and therapeutic cancer vaccines with special emphasis on the synthetic glycopeptide vaccines. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection