There is a dearth of information pertaining to the occurrence and prevalence of filarial helminth infections of dogs and cats in several provinces in South Africa. In this context the dissertation is a pilot survey that was conducted to determine the occurrence and prevalence of filarial helminth infections of dogs in the greater Mahikeng Local Municipality of North West province. The incentive for the choice of this location in the North West province was a reported high overall prevalence of 18 % of canine filariosis in the town of Gaborone in neighbouring Botswana. EDTA blood samples were collected from 100 live dogs between the ages of 1-11 years (53 males and 47 females). Only dogs that had not received treatment with macrocyclic lactone actives during the previous 12 months were included in the survey. A total of 13 different dog breeds were involved in the survey and the crossbreed animals were the most abundant (59 %) followed by the Boerboel (9 %). Blood samples were screened for the presence of microfilariae by means of the membrane filtration technique. There was no evidence of filarial infections in the 100 dogs sampled. / Dissertation (MSc)--University of Pretoria, 2018. / Veterinary Tropical Diseases / MSc / Unrestricted

Bakgrund: Astma är en inflammationssjukdom i luftvägarna, och en av de vanligaste kroniska sjukdomarna hos barn globalt sett. Vanligast är astma hos barn mellan 3 och 15 år, men hälften av alla barn som diagnostiserats med astma som barn har även betydande besvär upp i vuxen ålder. För en del av populationen har inte traditionell läkemedelsbehandling någon effekt, varför alternativa behandlingsmetoder så som omega-3 tillskott bör undersökas. Syfte: Syftet med innevarande litteraturstudie var att kartlägga om det finns evidens för om omega-3 tillskott kan användas i förebyggande eller symtomlindrande syfte hos barn (0–18 år) som löper hög risk för att utveckla astma eller som är diagnostiserade med astma. Metod: Studien utformades som en systematisk litteraturstudie. Litteratursökningar har genomförts i databaserna Pubmed, CINAHL och Medline. Sökningarna bestod av sökblocken astma, barn eller ungdomar och omega-3 tillskott/omega-3 fettsyror. Resultat: Denna studie inkluderar fem RCT-studier med syftet att undersöka om omega-3 tillskott kunde förebygga astma eller minska symtomen av astma hos barn, totalt 939 barn med astma har studerats i de fem studierna. Fyra studier påvisade att omega-3 tillskott till barn med astma inte har någon klinisk relevans medan en studie påvisade att klinisk relevans fanns. Slutsats: Denna systematiska litteraturstudie resulterade i att det inte finns någon evidens för att omega-3 tillskott skulle verka förebyggande eller symtomlindrande för barn med astma. RCT-studierna som inkluderats i denna systematiska litteraturöversikt är mycket heterogena och därför behövs vidare forskning på omega-3 tillskotts kliniska relevans. / Background: Asthma is an inflammatory disease in the airways, and is one of the most common chronic diseases in children globally. Asthma is most common in children between 3 to 15 years of age, but 50 % of children diagnosed with asthma as a child also have significant problems as adults. For some part of the population traditional drug treatment has no effect, indicating that alternative treatment methods, such as omega-3 supplements, should be investigated further. Aim: The aim of the current literature study was to investigate if there is any evidence of whether omega-3 supplements can be used for preventive or symptom-relieving purposes in children (0-18 years of age), who are at high risk of developing asthma or who have been diagnosed with asthma. Methods: The study was designed as a systematic review. Literature searches have been conducted using the Pubmed, CINAHL and Medline databases. The searches consisted of the search blocks asthma, children or adolescents and omega-3 supplements/omega-3 fatty acids. Results: This study includes five RCT studies that was aimed to investigate whether omega-3 supplements could prevent asthma or reduce the symptoms of asthma in children, a total of 939 children with asthma have been studied in the five studies. Four studies showed that omega-3 supplements for children with asthma have no clinical relevance, while one study showed that clinical relevance existed. Conclusion: This systematic review proved that no evidence for omega-3 supplements treatment, for preventive or symptom relieving purposes, in children with asthma exists. The RCT studies included in this systematic review are very heterogeneous and therefore further research on the clinical relevance of omega-3 supplement is needed.

The Térapa fossil vertebrate site, northcentral Sonora, Mexico, provides a rare opportunity to study the paleoenvironmental conditions present in northwestern Mexico during mid-Oxygen Isotope Stage (OIS) 3. Ostracode faunal assemblages and stable oxygen (δ18O) and stable carbon (δ13C) isotope values from ostracode calcite were used to reconstruct the seasonality of precipitation and vegetation cover at Térapa at 40-43 ka. The ostracode fauna was a non-analogue mix of temperate and tropical ostracode species composed of 13 species from 12 genera. The nearctic ostracodes Fabaeformiscandona caudata, Physocypria pustulosa, Cypridopsis vidua and the cosmopolitan ostracode Darwinula stevensoni dominate the assemblage. Two tropical ostracode genera, Chlamydotheca arcuata and Stenocypris sp., were present throughout the deposit and indicate that mean monthly summer temperatures were probably no more than 4°C to 6°C cooler than at present, based on available ecological information. Winter precipitation dominated the hydrologic cycle as evidenced by low ostracode δ18O values (-6‰ to -8‰ VPDB). Low ostracode δ13C values (-7‰ to -8‰ VPDB) suggest that local vegetation was dominated by C3 plants. A previous tooth enamel-based paleoenvironmental reconstruction at the same site favored a summer-dominated or evaporative hydrology and abundant C4 vegetation. The Térapa megafauna site exemplifies the need for multi-indicator paleoclimate reconstructions in desert environments where marked differences in the seasonality of precipitation and vegetation cover may occur.

Patients with pes planovalgus deformity often have coexisting spring ligament pathology. A primary repair of the ligament may fail during weightbearing due to chronic degeneration of the ligamentous tissue. Augmentation with a suture tape has been suggested to strengthen the repair. Limited data exist regarding flatfoot reconstruction with augmented spring ligament repair using a suture tape. This is a review of 57 consecutive patients who had flatfoot reconstruction with concomitant spring ligament augmented repair between July 2014 and August 2017. Weightbearing radiographic parameters were obtained preoperatively and compared to radiographs at an average time of 62 ± 46.5 (range 20-220) weeks postoperative. Significant improvements were seen in the radiographic parameters evaluated. Five patients had subsequent operations including one deep infection, 2 hardware removals remote to the spring ligament augmentation, 1 ankle arthrodesis, and 1 triple arthrodesis. Concomitant spring ligament repair augmented with a suture tape was a safe procedure that contributed to radiographic correction in a consecutive series of 57 patients undergoing flatfoot deformity correction.

Insulin-like growth factor binding proteins (IGFBPs) are known to be important modulators of the insulin-like growth factor (IGF-I). However, their precise role is as yet unclear. Further, recent studies have indicated that IGFBP-3 has a receptor mediated growth inhibitory response of its own. In the present study, we quantified the binding characteristics of IGFBP-3 to bovine aortic endothelial (BAE) cells. Binding studies at 4 ^oC were conducted and a specific binding curve for IGFBP-3 was obtained. IGFBP-3 was found to bind with an equilibrium dissociation constant (K_D) value of 3.1 x 10^-10 M. The role of heparan sulfate proteoglycans (HSPG) in the IGFBP-3 binding mechanism was also examined. It was seen that inactivation of the cell surface HSPGs with 75 mM sodium chlorate did not affect IGFBP-3 binding. Further, there have been reports of inhibition of IGFBP-3 binding by heparin in the media. Hence, the most probable interaction of HSPG with IGFBP-3 occurs in the extracellular region, with soluble HSPGs acting as receptors for IGFBP-3 and decreasing the net cell associated ligand receptor interaction. This is likely, since IGFBP-3 is known to possess a heparin binding domain. Simultaneous introduction of IGF-I and IGFBP-3 into the extracellular media decreased IGFBP-3 binding to the cell surface, which might imply that IGF-I and IGFBP-3 regulate each other's action. / Master of Science

Glycogen synthase kinase-3 (GSK3) is a ubiquitously expressed protein kinase with key roles in controlling proliferation, differentiation and survival of a wide variety of mammalian cells. In most cells, GSK3 is active in the absence of growth factor signaling and acts to inhibit cell proliferation and induce apoptosis. In cardiomyocytes, GSK3 plays a novel role as a negative regulator of cardiac hypertrophy, and it appears that GSK3 plays a central role as an inhibitor of cardiac hypertrophy induced by a variety of stimuli. In the present study, we sought to further elucidate the role of GSK3 in cardiomyocyte hypertrophy by studying the effects of inhibition of GSK3 in the absence of other hypertrophic stimuli. By combining global expression profiling with computational predictions and experimental analysis of transcription factor binding sites, we have identified hypertrophy-related genes that are controlled directly by GSK3 and have found that CREB is a major transcriptional target of GSK3 in cardiomyocytes. In addition, we find that inhibition of GSK3 is sufficient to induce the re-expression of fetal development genes characteristic of hypertrophy, but not sufficient to induce the full hypertrophic phenotype of cardiomyocyte growth.

Les aérosols troposphériques influencent la composition chimique de l’atmosphère, le bilan radiatif terrestre et le climat. Après formation, les aérosols subissent des processus de vieillissement altérant leurs propriétés microphysiques et chimiques. L’étude de l’impact environnemental des aérosols à différentes échelles spatio-temporelles doit donc tenir compte des transformations physico-chimiques. Les objectifs poursuivis sont : (i) d’étudier par microscopie analytique électronique à balayage et en transmission la composition élémentaire et l'état de mélange des particules atmosphériques prélevées lors d'épisodes de charge élevée en aérosol ; (ii) d’analyser les effets des propriétés microphysiques sur les caractéristiques optiques mesurées et restituées par télédétection ; (iii) de proposer un paramétrage ainsi qu’une représentation de la composition et de la structure des particules dans les algorithmes de télédétection. Ces travaux portent sur des observations dans le Nord de la France et en Afrique de l’Ouest (Sénégal) dans le cadre du Labex CaPPA et des campagnes de terrain SHADOW. Sont inclues des analyses complémentaires de la composition chimique et de la structure de particules individuelles, de mesures in situ et par télédétection de particules urbano-industrielles, désertiques et de biomasse prélevées en surface et à différentes altitudes. Une série de simulations numériques ont été utilisées dans le but d'analyser la sensibilité des observations par télédétection à l’état de mélange des aérosols. Enfin, l'intégration d'un paramétrage de la structure en "core-shell" des particules dans les algorithmes de restitution est présentée en perspective. / Tropospheric aerosols play an important role in atmospheric chemistry, Earth’s radiative budget and climate. After their generation, aerosol can suffer ageing processes and altering their physicochemical properties. An accurate accounting for these processes requires observations of the aerosol properties on different temporal and spatial scales. The current thesis work is dedicated to: (i) study of physicochemical properties and mixing state of individual particles by means of analytical scanning and transmission electron microscopy for aerosols collected during episodes of elevated aerosol loading; (ii) analysis of the effect of microphysical properties on optical characteristics as measured and retrieved by remote sensing; and (iii) investigation of possible parameterization of aerosol composition and structure in remote sensing algorithms. The work presents observations conducted in northern France and western Africa (Senegal) as part of Labex CaPPA project and SHADOW field campaigns. It includes simultaneous analyses of collected individual particles composition and structure, remote sensing and in situ observations of urban/industrial, Saharan dust and biomass burning particles near the surface and on different altitudes. A series of numerical simulation devoted to an analysis of sensitivity of remote sensing observations to aerosol mixing state is conducted. Insights on possible parameterization of aerosol core-shell structure in retrieval algorithms are finally presented.

The compound 3-phenylindole (3PI) is a particularly active antimicrobial which interacts with phospholipids in fungal mycelia membranes, and which strongly inhibits the uptake of phosphate into fungal mycelia. The physical effects of 3PI on ion transport across bilayer lipid membranes composed of phosphatidylcholine/cholesterol have been investigated using three lipophilic ions and one ion/carrier complex. It was found that 3PI increased the electrical conductivity induced by the lipophilic cation (tetraphenylarsonium) and by the positively charged complex (nonactin-K('+)) by several orders of magnitude whereas 3PI decreased the conductivity induced by the two lipophilic anions (tetraphenylborate, dipicrylamine) by a factor of less than ten. These conductivity changes are explained as a combination of changes in the electrostatic and in the non-electrostatic properties of the bilayer. The electrostatic potential of the bilayer interior was shown to decrease in the presence of 3PI, a phenomenon which was also confirmed by measurements of the surface potential of phosphatidylcholine/cholesterol monolayers. The changes in non-electrostatic properties of the bilayer are qualitatively discussed in terms of increased bilayer fluidity or decreased bilayer thickness brought about by the presence of 3PI. The partition coefficient of the lipophilic anions, as determined by the voltage-step transient current technique, decreased slightly when 3PI was present in the aqueous phase. From the voltage dependence of the normalized steady state conductivity it was shown that 3PI did not kinetically limit tetraphenylarsonium transport but that it did kinetically limit nonactin-K('+) transport at concentrations greater than 25 (mu)M 3PI. The theory of carrier-mediated transport predicts the occurrence of transient currents in the kinetically limited regime but no transients were detected for nonactin-K('+) in the presence of 80 (mu)M 3PI. A method for analyzing the adsorption of neutral lipophilic molecules onto lipid monolayers has been presented, and by this method it was found that the partition coefficient of 3PI onto phosphatidylcholine/cholesterol monolayers was 1.3 x 10('-4) m and that the maximum adsorbed surface number density of 3PI was 1.1 x 10('-6) moles/m('2). From the experimental changes in monolayer surface potential as a function of adsorbed surface number density, a value for the normal component of the dipole moment of 3PI was obtained.

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