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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

The potential value of homoeoprophylaxis in the long-term prevention of infectious diseases, and the maintenance of general health in recipients

Golden, Isaac, homstudy@netconnect.com.au January 2002 (has links)
Homoeoprophylaxis (HP) is the use of homoeopathically prepared substances to prevent targeted infectious diseases in recipients. Its first use in an epidemic of Scarlet Fever was documented in 1801. It has been used throughout the world since then for both short-term and long-term preventative purposes. The effectiveness and safety of Golden�s long-term HP program using homoeopathically prepared substances to prevent targeted infectious diseases in recipients was tested through two research projects. The effectiveness of the program could not be established with statistical certainty given the limited sample size and the low probability of acquiring an infectious disease. However, a possible level of effectiveness of 90.3% was identified subject to specified limitations. Further research to confirm the effectiveness of the program is justified. Statistically significant results were obtained that confirmed the safety of the program both in absolute terms as well as compared to all other methods of disease prevention studied. It also appeared possible that a national immunisation system where both vaccination and HP were available to parents would increase the national coverage against targeted infectious diseases, and reduce the incidence of some chronic health conditions, especially asthma.
312

Pharmacokinetic characterization of the main flavonoids in the extract of Scutellariae Radix / 黃芩水提物中主要黃酮類成份的藥代動力學研究

Cai, Yu January 2011 (has links)
University of Macau / Institute of Chinese Medical Sciences
313

A phytochemical study of Cnicus benedictus L. (Carduus benedictus)

Miller, Lawrence P. January 1926 (has links)
Thesis (M.S.)--University of Wisconsin, 1926. / Includes bibliographical references (p. 32-42) and index.
314

THE STRUCTURAL ELUCIDATION OF ANTI-TUMOR AGENTS FROM PLANTS

Tempesta, Michael Steven January 1981 (has links)
The structural elucidations of nine new natural products from Thevetia ahouia, Eremocarpus setigerus, Trichilia hispida, Chrysothamus paniculatus, Uvaria acuminata, Wikstroemia monticola, and Uvaria zelanica are discussed in detail. Also included are some known compounds that were found in these plants. Of the new compounds discussed, two are diterpenes (eremone, chrysothame), two are relatively simple triterpenes (hispidols A, B), two are highly oxidized triterpenes (hispidins A, B), one is a fatty acid derivative (uvaricin), one is a shikimate-derived metabolite (1-epizeylenol), and one has both steroidal and carbohydrate features (3'-OMe-evomonoside). ¹H and ¹³C NMR spectral data are given for all the new compounds. Assignments were made by analogy with model compounds, computer simulation, and ¹H-¹H and ¹H-¹³C decoupling where indicated. High resolution mass spectral fragmentations are given for most of the new compounds, and individual structural assignments made for intense peaks. An X-ray analysis (eremone) was done with all pertinent information included. Most of the compounds have been tested for anti-tumor activity, and several exhibit strong cytotoxicity (hispidins A and B, 3'-OMe-evomonoside, huratoxin, uvaricin).
315

Neuroprotective effects of ginsenoside Rb1 on primary cultured rat cortex neural progenitor cells in tert-butylhydroperoxide-induced oxidative injury

Ni, Na January 2014 (has links)
University of Macau / Institute of Chinese Medical Sciences
316

Pathogenic mechanisms in mitochondrial optic neuropathies

Maresca, Alessandra <1982> 05 May 2011 (has links)
Leber’s hereditary optic neuropathy (LHON) and Autosomal Dominant Optic Atrophy (ADOA) are the two most common inherited optic neuropathies and both are the result of mitochondrial dysfunctions. Despite the primary mutations causing these disorders are different, being an mtDNA mutation in subunits of complex I in LHON and defects in the nuclear gene encoding the mitochondrial protein OPA1 in ADOA, both pathologies share some peculiar features, such a variable penetrance and tissue-specificity of the pathological processes. Probably, one of the most interesting and unclear aspect of LHON is the variable penetrance. This phenomenon is common in LHON families, most of them being homoplasmic mutant. Inter-family variability of penetrance may be caused by nuclear or mitochondrial ‘secondary’ genetic determinants or other predisposing triggering factors. We identified a compensatory mechanism in LHON patients, able to distinguish affected individuals from unaffected mutation carriers. In fact, carrier individuals resulted more efficient than affected subjects in increasing the mitochondrial biogenesis to compensate for the energetic defect. Thus, the activation of the mitochondrial biogenesis may be a crucial factor in modulating penetrance, determining the fate of subjects harbouring LHON mutations. Furthermore, mtDNA content can be used as a molecular biomarker which, for the first time, clearly differentiates LHON affected from LHON carrier individuals, providing a valid mechanism that may be exploited for development of therapeutic strategies. Although the mitochondrial biogenesis gained a relevant role in LHON pathogenesis, we failed to identify a genetic modifying factor for the variable penetrance in a set of candidate genes involved in the regulation of this process. A more systematic high-throughput approach will be necessary to select the genetic variants responsible for the different efficiency in activating mitochondrial biogenesis. A genetic modifying factor was instead identified in the MnSOD gene. The SNP Ala16Val in this gene seems to modulate LHON penetrance, since the Ala allele in this position significantly predisposes to be affected. Thus, we propose that high MnSOD activity in mitochondria of LHON subjects may produce an overload of H2O2 for the antioxidant machinery, leading to release from mitochondria of this radical and promoting a severe cell damage and death ADOA is due to mutation in the OPA1 gene in the large majority of cases. The causative nuclear defects in the remaining families with DOA have not been identified yet, but a small number of families have been mapped to other chromosomal loci (OPA3, OPA4, OPA5, OPA7, OPA8). Recently, a form of DOA and premature cataract (ADOAC) has been associated to pathogenic mutations of the OPA3 gene, encoding a mitochondrial protein. In the last year OPA3 has been investigated by two different groups, but a clear function for this protein and the pathogenic mechanism leading to ADOAC are still unclear. Our study on OPA3 provides new information about the pattern of expression of the two isoforms OPA3V1 and OPA3V2, and, moreover, suggests that OPA3 may have a different function in mitochondria from OPA1, the major site for ADOA mutations. In fact, based on our results, we propose that OPA3 is not involved in the mitochondrial fusion process, but, on the contrary, it may regulate mitochondrial fission. Furthermore, at difference from OPA1, we excluded a role for OPA3 in mtDNA maintenance and we failed to identify a direct interaction between OPA3 and OPA1. Considering the results from overexpression and silencing of OPA3, we can conclude that the overexpression has more drastic consequences on the cells than silencing, suggesting that OPA3 may cause optic atrophy via a gain-of-function mechanism. These data provide a new starting point for future investigations aimed at identifying the exact function of OPA3 and the pathogenic mechanism causing ADOAC.
317

A homoeopathic drug proving of Hemachatus haemachatus, with a subsequent comparison of the proving symptoms with that of other snake remedies used in homeopathy

De la Rouviaere, Lize January 2008 (has links)
Mini-dissertation submitted in partial compliance with the requirements of the Master’s Degree in Technology: Homoeopathy in the Faculty of Health Sciences at the Durban University of Technology, 2008. / The aim of this study was to elicit and document the effects, in the form of signs and symptoms produced in relatively healthy volunteers, of the venom of Hemachatus haemachatus, prepared in accordance with the methods set out in the homoeopathic pharmacopoeia. These signs and symptoms form the indications for the prescription of the remedy, according to the homoeopathic Law of Similars. A further aim of this study was a comparative analysis of symptoms produced by Hemachatus haemachatus 30ch with existing remedies derived from snake venom used in homeopathy, with the aim of highlighting the similarities and differences between them. The homoeopathic drug proving of Hemachatus haemachatus 30ch took the form of a double-blind, placebo controlled trial. The proving population consisted of 30 healthy subjects who met with the necessary inclusion criteria (Appendix B). Eighty percent (24 subjects) served as the experimental group, receiving the active verum in a randomised manner, while twenty percent (6 subjects) formed the placebo group, receiving non-medicated placebo powders in a randomised manner. Provers were unaware of either the nature or potency of the substance. Verum and placebo were indistinguishable from each other, and neither researcher nor volunteers knew who received verum and who received placebo. Intra-individual control was achieved through a pre-proving observation period of a week’s duration, during which provers recorded the signs and symptoms of their normal state. This symptom picture served as a baseline for comparison with symptoms noted after administration of the remedy. Verum and placebo were dispensed in the form of six powders to be taken sublingually three times a day for a period of two days, or until the onset of symptoms. Data was primarily collected in the form of a diary or journal kept by each prover in which they recorded symptoms on a daily basis. Provers were closely monitored by the researchers during this period. Data collected by the researchers during daily telephonic contacts, as well as during the pre-proving consultation, was also considered. Information obtained from the journals was then assessed by the researchers for suitability for inclusion in the materia medica of Hemachatus haemachatus. The data did not require statistical analysis. In a concurrent study of similar methodology, Cahill (2008) conducted a comparison of the symptom complex produced in the proving of Hemachatus haemachatus, with other homeopathic remedies which scored highest on repertorisation. Symptoms from both studies were collated and included in the materia medica and repertory of Hemachatus haemachatus. The investigation supported the hypothesis that Hemachatus haemachatus would produce clear and observable signs and symptoms in healthy proving volunteers. During the course of this study provers experienced a wide range of mental, emotional and physical symptoms. The highest number of symptoms was produced on the mental and emotional level. Provers experienced elation, joy, increased confidence, enthusiasm and energy. On the other hand, there was lack of confidence, vulnerability, anxiety, decreased motivation, decreased concentration, lethargy, depression and indifference. There were sudden changes in mood and provers experienced marked irritability. On the physical level, many provers experienced headaches, irritation of the eyes, symptoms resembling allergic rhinitis, sore throats, nausea, heartburn, abdominal pain and flatulence, menstrual disturbances, lumbar pain, rheumatic joint pains, and skin eruptions. There were disturbances in normal sleep patterns, subjective perceptions of increased body temperature with hot flushes, and generalised tiredness and lethargy. Symptoms obtained from the proving of Hemachatus haemachatus were analysed as part of a comparative study with other remedies derived from snake venom: Lachesis muta, Naja tripudians, Elaps corallinus, Naja mossambica and Bitis arietans arietans. This comparison highlighted both the similarities and differences between these remedies and Hemachatus haemachatus.
318

Co-polymer microgels : contemporary physico-chemical, structural and analytical investigations

Gracia, Louise Henrietta January 2007 (has links)
Poly(N-isopropylacrylamide), [poly(NIPAM)], is a thermosensitive polymer which undergoes a conformational transition at approximately 32°C in aqueous solution. NIPAM is a monomer commonly employed in microgel synthesis and the resultant particles are thermosensitive, a property which can be altered by modification of the system by co-polymerisation. A series of colloidal microgels have been prepared by surfactant-free emulsion polymerisation (SFEP) based on the NIPAM monomer. Butyl acrylate (BuAc) has been used as a co-monomer in order to alter the physico-chemical properties of poly(NIPAM) microgel particles. Thermosensitive poly(NIPAM/BuAc) homopolymeric/co-polymers microgels have been prepared with various monomer ratios, ranging from pure poly(NIPAM) to pure poly(BuAc), both cross-linked using N', N'-methylenebisacrylamide (BA). The microgel series have been characterised by turbidimetric analysis, dynamic light scattering, electrophoretic mobility measurements and TEM to determine particle size and volume phase transition (VPT) behaviour. The incorporation of BuAc has been found to reduce the volume phase transition temperature (VPPT) of poly(NIPAM). Small-angle neutron scattering (SANS) has been employed as a structural probe to interrogate the internal particle structure of co-polymer microgel particles prepared in a one pot reaction. The structure, with respect to monomer distribution, has been investigated by contrast matching SANS, using both deuteriated and non-deuteriated microgel particles. Co-polymer microgels prepared using NIPAM and BuAc, synthesised by SFEP in a one-pot reaction, were found to possess a structure comprising of regions rich in BuAc appearing as defined clusters within the gel like network.
319

Membrane investigations using infra-red spectroscopy and multivariate target factor analysis

Russeau, Wanessa January 2007 (has links)
Mid Infrared spectroscopy coupled with multivariate Target Factor Analysis (TFA) was used to investigate permeation and localisation of drugs through and within synthetic membranes and human skin. Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy was used for the diffusion experiments, and Mid-IR mapping for the drug distribution studies in human skin. A proof of concept was established through these studies, for a rapid screening protocol of membranes in general. Mid-IR reference spectra of the compounds were systematically collected to form a library for subsequent data interpretation. Reproducibility studies using a solution of methyl paraben (MP) in ethanol (EtOH) and water through Carbosil and polydimethylsiloxane (PDMS) or silicone were conducted. Carbosil membrane is more complex membrane than PDMS as it has a heterophase domain structure composed of PDMS and polycarbonate (PC). It was found that an extremely good contact between the membrane and the ATR crystal was essential in order to obtain good reproducibility. Carbosil had an excellent contact and thus good reproducibility was obtained, whereas the opposite was found for the type of silicone membrane used. Also, the power of TFA to deconvolute very similar compounds such as MP and propyl paraben (PP), within a same data set, was successfully demonstrated. Diffusion experiments on a series of model drug compounds, i.e. methyl paraben (MP), ibuprofen (IBU) and caffeine (CF) in water and ethanol were studied through a synthetic membrane and human skin. The spectral data collected were complex, and were therefore, analysed by multivariate TFA. The data were successfully deconvoluted obtaining, in most of the cases, a high correlation between the deconvoluted factors from the data and the reference spectra of the compounds of interest. then evolution profiles for the diffusion of the species with time for the drug, and solvents were obtained for Carbosil as well as for skin, even though in the case of the skin the data were still more complex. A commercial formulation of IBU was also examined using human skin. Again most of the components were successfully deconvoluted and evolution profiles were obtained. Finally, Mid IR and TFA was used to localise a lipophilic drug within the layers of human skin. The distribution and localisation of the drug in the skin layers was successfully studied by adopting a multivariate analysis approach based on TFA. The compound was successfully localised and the greatest relative concentration was observed within hair follicles as expected. The ensemble of these experiments demonstrates that IR spectroscopy coupled with TFA is a valuable tool for the study of membranes, particularly skin. It also opens up a novel approach to high throughput screening in formulation development.
320

Phytochemical and pharmacological studies on some endemic Yucatecan medicinal plants

Sanchez-Medina, Alberto January 2007 (has links)
Four endemic medicinal plants from the Yucatan peninsula belonging to genera with little pharmacological and phytochemical reported information and used for medicinal purposes by local communities were selected. The species selected included Jacquinia flammea Millsp. ex Mez, Sideroxylon foetidissimum Jacq. subsp. gaumeri, Serjania yucatanensis Standl., and Serjania adiantoides Radlk. The root, stem/bank and leaves of each plant species were extracted using ethanol and the resulting crude extracts were tested for their cytotoxic effect using the modified MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) assay followed by a bioassay-guided fractionation of the most active extracts in order to identify the active metabolites. The initial cytotoxic evaluation against HeLa cells at two fixed concentrations (100 and 33.3 µg/mL) identified the root extracts f J. flammea, S. foetidissimum subsp. gaumeri and S. yucatanensis, and the stem/bank extract of S. adiantoides as the most active extracts. The crude extract of roots of J. flammea was subjected to solvent partition using solvents of ascending polarity (pet. ether, CHCI3, EtOAc, BuOH and water). The resulting fractions were tested for their cytotoxic activity. The water fraction of the solvent partition showed the strongest activity against HeLa cells (IC50 = 28.61 ± 2.27 µg/mL). When tested against RAW 264.7 cells, the water fraction also showed significant activity (IC50 = 10.60 ± 1.83 µg/mL). The water fraction was subjected to chromatographic fractionation using open silica gel columns resulting in the isolation of a saponin as the most active metabolite against RAW 264.7 cells (IC50 = 4.76 ± 0.32 µg/mL). The isolated compound was identified using 1D (1H and 13C and DEPT-135) and 2D (COSY, HMBC, HSQC and NOESY and ROESY) NMR and mass spectrometry analysis as sakurasosaponin. The molluscicidal and antifungal activities of sakurasosaponin have been reported but no studies on its cytotoxic activity have been previously reported. The crude extract of roots of S. foetidissimum subsp. gaumeri was subjected to solvent partition using solvents of ascending polarity (pet. ether, CHC13, EtOAc, and BuOH). The resulting fractions were tested for their cytotoxic activity. The BuOH extract of S. foetidissimum subsp. gaumeri showed the strongest activity against RAW 264.7 cells (IC50 = 35.12 ± 4.32 µg/mL) and it was subjected to further chromatographic fractionation using open silica gel columns yielding mixtures of saponin-containing fractions. The crude extract of roots of S. yucatanensis was subjected to solvent partition using solvents of ascending polarity (pet. ether, CHCI3, EtOAc, and BuOH). The resulting fractions were tested for their cytotoxic activity. The crude extract of S. adiantoiodes did not show cytotoxic activity when tested against RAW 264.7 cells.

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