Delayed hypersensitivity can be conferred passively to normal animals. There exists a period when whole peritoneal exudate cells will passively confer delayed sensitivity, but a sonic extract from them will not; however, after a few more days, both whole cells and sonic extracts could transfer sensitivity. This investigation was undertaken to study the differences in cells collected at two different time intervals after initial sensitization of guinea pigs with 1-fluoro-2,4-dinitrobenzene.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 135-145). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 135-145). Also available on the Internet.

Submitted in partial fulfilment of the requirements for the Degree of Masters in Technology: Clinical Technology, Durban University of Technology, 2013. / Introduction : Effusive constrictive pericarditis (ECP) is a clinical syndrome characterized by concurrent pericardial effusion and pericardial constriction where constrictive haemodynamics are persistent after the pericardial effusion is removed. Although first observed in the 1960s, it was not until the publication of a 13 patient-case series by Hancock in 1971, and the prospective cohort publication by Sagrista-Sauleda in 2004, that more information about the aetiology, incidence, and prognosis of effusive-constrictive pericarditis became known (Sagrista-Sauleda, Angel, Sanchez, Permanyer-Miralda, and Soler-Soler 2004). Hancock (1971) first recognized that some patients presenting with cardiac tamponade did not have resolution of their elevated right atrial pressure after removal of the pericardial fluid. In these patients, pericardiocentesis converted the haemodynamics from those typical of tamponade to those of constriction. Thus, the restriction of cardiac filling was not only due to the pericardial effusion but also resulted from pericardial constriction (predominantly the visceral pericardium). The hallmark of effusive-constrictive pericarditis is the persistence of elevated right atrial pressures after the intrapericardial pressure has been reduced to normal levels by the removal of the pericardial fluid. Aims and Objectives : This study was carried out to determine the prevalence of ECP in a cohort of patients with large effusions of Tuberculosis origin. The primary objective was to measure pre and post- pericardiocentesis intrapericardial and right atrial cardiac pressures in all patients undergoing pericardiocentesis in order to determine the relative proportion of effusive constrictive pericarditis in these patients. The secondary objective was to determine if any echocardiographic features can help predict the presence of ECP by studying the three parameters two-week post-pericardiocentesis. Methodology : Fifty consecutive patients with pericarditis presenting to Groote Schuur Hospital and surrounding hospitals referred for pericardiocentesis, who met the inclusion criteria were recruited to participate in the study. All patients had the right atrial and intrapericardial pressures simultaneously measured and recorded, before and after pericardiocentesis. The pressures were analyzed to determine the presence of ECP, which was defined as failure of the right atrial pressure to fall by 50% or to a new level of ≤12 mmHg after the intrapericardial pressure is lowered to below 2 mmHg. Participants also had an echocardiogram done two weeks post pericardiocentesis. Three echocardiographic features of constriction were studied, to determine if they can predict the presence of ECP. The parameters studied were 1) Thickened pericardium, 2) Dilated inferior vena cava (IVC) and 3) Septal bounce. Results : This study showed a 34% (17 0f 50) prevalence of ECP in patients with TB pericarditis. It also showed a statistically difference in the right atrial and intrapericardial pressures pre and post pericardiocentesis, between patients with ECP and those without. The echocardiographic parameters studied showed no difference between ECP and non ECP, and also did not predict the presence of ECP. Discussion : In the cohort of patients (n=50), the prevalence of ECP was found to be 34%. This is much higher than that observed in the Sagrista-Sauleda et al., (2004) study. They found a prevalence of 1.3% amongst patients with pericardial disease of any type and 6.95% amongst patients with clinical tamponade. The authors did state that they expected the true prevalence to be higher than estimated as not all patients underwent catheterization. Pre-pericardiocentesis pressures, both right atrial and intrapericardial, were found to be higher in patients with ECP than in those without. This is in keeping with published results, such as the study of Hancock (1971) The echocardiographic parameters studied were two weeks post pericardiocentesis, because the diagnostic accuracy of echocardiogram has been shown to be very poor at the time of tamponade. The presence of these parameters (thickened pericardium, dilated IVC and septal bounce), did not predict the presence of ECP. This could be due to the fact that less than 50% of participants had an echocardiogram two weeks post pericardiocentesis. Conclusions : The results of this study show that ECP is actually more common than thought in a population with TB pericarditis. This syndrome may be missed in most patients due to the fact that not all centres measure right atrial and intrapericardial pressures at the time of pericardiocentesis. Echocardiography is not able to predict the presence of ECP. Other non-invasive imaging techniques such is computerized tomography (CT) and cardiac magnetic resonance imaging (CMRI) have shown good results in diagnoses of ECP. The importance of early diagnosis of ECP lies in recognition that removal of pericardial fluid alone may not be enough; patients may need to have surgery. Given the high prevalence shown by the study, ideally all patients with pericardial effusion should have haemodynamic monitoring at the time of pericardiocentesis.

The term 'gum', in its broadest sense, refers to both hydrophobic and hydrophilic substances of high molecular weight which usually exhibit colloidal properties when dispersed in an appropriate solvent. Hydrophobic substances often called gums include high molecular weight hydrocarbons and other petroleum products, rubbers, certain synthetic polymers and resinous saps which often exude from evergreens. More specifically, the term gum applies to plant polysaccharides or their derivatives which are dispersible in either cold or hot water to produce viscous solutions or suspensions. As much as three-quarters of the dry weight of plants may be polysaccharide and, consequently, such substances are of wide occurrence. The most important gums, however, are those which are readily obtainable in large amounts from the plant. Some of these gums are used industrially and, indeed, many have been known since ancient times. One of the chief sources of such polysaccharides is seaweed which furnishes agar, algin and carrageenin while seed gums, such as gum guar and locust bean gum, are also important, particularly from the point of view that the plant which produces the seeds is often grown extensively as a food crop. In contrast to these naturally occurring gums, other gums are obtained from cellulose, one of the main components of the plant cell wall, and starch, a food reserve polysaccharide, by esterification and etherification. Commercially, however, the most important gums are plant exudates and most plant families have been found to include species which exude gums to a greater or lesser degree. In this context, the term 'exudate gum' strictly refers to those commercially important gums which exude in copious amounts from shrubs or low-growing trees, forming, on exposure to the atmosphere, glossy nodules or flakes which are usually brown or yellow in colour. These gum producing trees grow predominantly in Africa or Asia indicating the climatic requirements for their growth.

An investigation of the spectral reflectance of the fundus in normals and patients with common eye diseases was carried out using a multi wavelength scanning laser ophthalmoscope (SLO). With a knowledge of the spectral properties of the principal ocular pigments in the fundus, the appearance of the retina and choroid is predictable in normal subjects. The optic disc has a characteristic dark appearance when viewed with the SLO, and reasons for this may include a filtering effect of the confocal aperture to reduce the return of scattered light to the detector. In patients with macular exudates these features have a high reflectance in green-yellow light. An image processing method has been developed to quantify exudates and this was applied to SLO images and digitised colour slides of the same patients. Results show similar performance of processing in both image types with high accuracy (90% sensitivity for 95% specificity). A similar experiment was carried out on patients with macular drusen. These structures are of lower intensity than exudates and may have less well-defined borders. Again performance of the image processing methods showed broadly similar performance when comparing SLO images and digitised colour slides (60 to 68% sensitivity for 95% specificity). A study was carried out to assess the ability of the SLO to image the fundus in patients with cataract using a range of wavelengths. In conclusion the SLO offers the ability to image the fundus at selected wavelengths to enhance the desired features under investigation. As a fundus camera, used to generate digital images, it is unlikely to offer significant improvements over commercially available digital imaging CCD cameras. However, the SLO has properties which are likely to make it an ideal instrument for reflectometry, angiography and fundus topography. These applications are discussed in the final chapter.

Root exudates include important chelating compounds and can change the rhizosphere pH by several units. These changes are essential for nutrient uptake and can also alter solubility of soil contaminants and increase plant uptake. Mild root-zone stress may increase exudation and more severe stress can damage membranes and increase root turnover, all of which increase root-zone carbon. Increased carbon from this rhizodeposition can increase microbial activity, which might help degrade contaminants. We studied the effect of three types of stress on root exudation of crested wheatgrass (Agropyron cristatum): low K+, drought, and flooding. These stresses were compared to two types of controls: 100% NO3- and high NH4+:NO3- ratio. We developed an improved axenic system to keep plants microbe-free for 70 days while analyzing exudates for total organic carbon (TOC) and organic acids. Axenic conditions were confirmed by plate counts of the leachate and microscopic observations of the leachate and roots. Optimal conditions for plant growth were maintained by monitoring temperature, light, humidity, water, O2, CO2, nutrient availability, and root-zone pH. Plants were grown in Ottawa sand that was layered by size to optimize water availability. Total organic carbon released over the 70-day growth period in mg per gram dry plant was 2.6 in the control, 2.3 in the NH4+ treatment, 3.7 in the flood and K+ stress treatments, and 4.4 in the drought treatment, which was the only treatment significantly higher than controls (p = 0.05). TOC and organic acid levels in the exudates peaked before the end of the study. The peak TOC levels, expressed as mg TOC per gram new dry plant mass, were 1.9 in the control, 3.0 in the NH4+ treatment, 2.9 in the flood, and 5.8 in the drought and K+ stress treatments. Organic acids were measured by gas chromatography-mass spectrometry (GC-MS). Malic acid was the predominant organic acid, and accounted for the majority of the TOC in the drought treatment. Oxalic, succinic, fumaric, and malonic acids accounted for less than 10% of the TOC. These data indicate that stress may enhance phytoremediation by changing root-zone exudate composition.

The rhizosphere is characterized by the presence of high microbial activities which are influenced by plant root exudates. This study examined bacterial diversity and physiological functions plants rhizosphere using both culture-dependent and culture-independent techniques of seven cultivated. Physico-chemical properties of soil samples revealed that the rhizobacteria adapted well to pH ranging from 7.5 to 9.1. Macronutrients (carbon, nitrogen, calcium, magnesium, phosphorous, potassium, sodium and iron) had a wide range of concentration between 0 to 4380.1 mg/kg. Concentrations of metal elements (cadmium, cobalt, chromium, copper and zinc) from all rhizosphere samples were below the amount of 3.1 mg/kg, indicating that the samples were free from metal contaminations. Sole carbon substrates utilization of bacteria in rhizosphere samples were measured as Average Well Colour Development (A WCD) and Group-wise Average Well Colour Development (AWCDg) patterns. At seventy two hours, there was no significant difference in AWCD patterns between bacteria in all samples and there was a significant difference in AWCDg patterns. Biochemical tests showed majority of isolates had similar physiological properties to members of Bacillus genus. All the bacterial isolates exhibited positive antifungal trait, fifteen solubilized phosphate and three had cyanide production traits during in vitro plant growth promotion assays. In vitro plant growth revealed that bacterial isolate RL1 (Bacillus licheniformis) produced the highest concentration of indole acetic acid (IAA) at 25 mg/ml. Bacterial isolate RG3 (Bacillus pumilus) had the highest amino cyclopropane carboxylase (ACC) deaminase activity indicated by the high production of α-ketobutyrate produced at 4.8 mg/ml. There were significant differences in shoot length at P ≤ 5% level of significance and there was no significant difference in the number of leaves across all three inoculated plants at P ≥ 5% level of significance. Sequence and phylogenetic analysis of identified culture-dependent bacteria revealed a homologous similarity of 94 to 100% between isolates sequences and GenBank sequences. From this, 81% of the sequences were closely related to Firmicutes, 13% to Actinobacteria and 6% to Proteobacteria. From cultureindependent method, only 8 PCR-DGGE bands were detected, the 200 bp sequences in the 16S rRNA fragment showed 91 to 100% homologous similarity to GenBank sequences. Their 16S rRNA sequences was closely related to 50% uncultured bacterium clones, 25% Firmicutes, 13% Proteobacteria and 12% Bacteroidetes sequences. Both culture-dependent and cultureindependent techniques were precise in the identification and description of bacterial community in rhizosphere. / Thesis (M.Sc) North-West University, Mafikeng Campus, 2014

Diss. (sammanfattning) Linköping : Linköpings universitet, 2007. / Härtill 4 uppsatser.

Parmi les matériaux qui ont été exploités dans l'Antiquité, les substances organiques sont probablement les plus difficiles à étudier en raison de leur altération partielle ou totale en raison de leur nature organique. Issus de biomatériaux organiques tels que les résines, la cire d'abeille, les graisses animales ou les huiles végétales, ils sont conservés en faible quantité comme résidus organiques amorphes et sont souvent difficiles à détecter sur le terrain archéologique. Ils témoignent de l'utilisation de produits d'origine animale, végétale et fossile qui ont une grande importance pour divers aspects de la vie humaine, notamment l'alimentation, la médecine, les rituels funéraires, ainsi que les activités économiques et techniques. Comme ils n'ont pas d'attributs morphologiques reconnaissables, la seule façon de déterminer leur nature et leur origine repose sur l'élaboration de stratégies analytiques qui permettent d'élucider leur composition chimique. Ces substances ont des caractéristiques communes dans le domaine de l'archéologie et de la chimie : elles sont constituées de mélanges moléculaires complexes qui sont souvent conservés en faible quantité. Dans certains cas, ces matériaux ont été mélangés avec divers adjuvants tels que la cire d'abeille, les huiles végétales, les graisses animales, l'argile et l'ocre, entre autres, qui devront également être pris en considération pour la caractérisation des objets qui appartiennent au patrimoine culturel. Nous concentrons nos recherches sur les exsudats et les goudrons de plantes frais et fossiles qui ont été largement utilisés depuis la préhistoire en Europe. Concernant l'étude des substances organiques fraîches, des recherches ethnoarchéologiques ont été menées en collaboration avec le projet ONGUENT (Goudrons végétaux à usage médicinal en Méditerranée : passés et présents. Burri, Sylvain/Traces, Toulouse) afin d'identifier et de caractériser la composition chimique et d'établir les biomarqueurs des goudrons de conifères ethnoarchéologiques de Cupressaceae et Taxaceae (Juniperus oxycedrus, Juniperus thurifera, Taxus baccata, Tetraclinis articulata) provenant de techniques anciennes du Haut Atlas au Maroc. En comprenant les méthodes de fabrication des échantillons ethnoarchéologiques et en évaluant les différentes techniques employées dans leur production, il est possible d'obtenir des données de référence sur les matériaux contemporains. D'autre part, des échantillons archéologiques ont été analysés sur différents sites entre l'Europe et l'Asie au moyen des méthodes FTIR, SEM, DI-MS, et GC-MS. La caractérisation biomoléculaire de produits naturels tels que le goudron d'écorce de bouleau et la résine de pin a été soulevée. Par ailleurs, des mélanges de résine de pin avec du goudron d'écorce de bouleau et de résine de pin avec une espèce appartenant à la famille des Burseraceae ont été identifiés. / Among the materials that have been exploited in ancient periods, organic substances are probably the most challenging to study due to their partial or total alteration in consequence of their organic nature. Issued from organic biomaterials such as resins, beeswax, animal fats or plant oils, they are preserved in low amount as amorphous organic residues and are often difficult to detect at the archaeological field. They give evidence for the use of animal, plant and fossil products that were of great importance for various aspects of human life, including diet, medicine, funerary rituals, as well as economic and technical activities. Because they lack recognizable morphological attributes, the only way to determine their nature and origin relies on the development of analytical strategies that allow elucidation of their chemical composition. These substances share common features in the field of archaeology and chemistry: they are made of complex molecular mixtures which are often preserved at low amount. In some cases, these materials were mixed with various adjuvants such as beeswax, plant oils, animal fats, clay, and ochre, among others, that will also need to be considered for the characterization of the objects that belong to the Cultural Heritage. We focus our research on fresh and fossil plant exudates and tars that have been largely used since prehistory onwards in Europe. Concerning the study of fresh organic substances, ethnoarchaeological research has been carried out in collaboration with the ONGUENT project (Goudrons végétaux à usage médicinal en Méditerranée: passés et présents. Burri, Sylvain/Traces, Toulouse) in order to identify and characterize the chemical composition and establishing the biomarkers of the ethnoarchaeological conifer tars from Cupressaceae and Taxaceae (Juniperus oxycedrus, Juniperus thurifera, Taxus baccata, Tetraclinis articulata) obtained from antique techniques in the High Atlas, Morocco. By understanding the manufacturing methods of ethnoarcheological samples and to assess the different techniques employed in their production, it is possible to obtain a reference data on contemporary materials.On the other hand, archaeological samples were analyzed from different sites between Europe and Asia by means of FTIR, SEM, DI-MS, and GC-MS methods. Biomolecular characterization of natural products such as birch bark tar and pine resin were raised. Besides, mixtures between pine resin with birch bark tar and pine resin with a species belonging to the family of Burseraceae were identified.