1,720,960 research outputs found
1 THE EFFECT OF ACUTE GOUT ON INFLAMMATORY MARKERS IN HYPERURICEMIC PATIENTS
Get PDFtowards this research is hereby acknowledged. Opinions expressed and conclusions arrived at, are those of the author and are not necessarily to be attributed to the NRF. © University of Pretoria 2 Table of content
A comparison of the efficacy and cost of intravenous and oral formulations of ondansetron against chemotherapy-induced nausea
Get PDFDissertation (MSc)--University of PretoriaIntroduction: Nausea and vomiting are the most common and distressing side effects of chemotherapy because they negatively impact on quality of life and treatment compliance. Adequate control of nausea and vomiting in children receiving chemotherapy is imperative. Currently, the first-line drug for the prophylaxis and treatment of chemotherapy-induced nausea and vomiting (CINV) in paediatric patients is the serotonin (5HT3) receptor antagonist, ondansetron, administered intravenously. However, the parenteral route of administration of this drug is now being questioned as it is inconvenient for children and there is pressure to switch to an available oral formulation. The aim of this study was to evaluate the ease of administration, efficacy and cost-effectiveness of intravenous (IV) and oral tablet (OT) formulations of ondansetron in paediatric cancer patients receiving moderately emetogenic chemotherapy at the Steve Biko Academic Hospital in Pretoria, Gauteng (South Africa).Methods: It was an open-label, parallel, randomized trial. Thirty (30) patients scheduled to receive moderately emetogenic chemotherapy were recruited from the paediatric oncology department of the hospital. These patients were randomized to receive the same dose of either IV or OT ondansetron for the prophylaxis of CINV for one chemotherapy cycle. The efficacy of the agents was determined using a visual analogue scale (VAS) completed by the paediatric patients, which was compared to a one page questionnaire completed by the parents of the patients. Both questionnaires were completed at the end of chemotherapy (treatment period) as well as after a week without chemotherapy treatment (follow-up period). The patients’ plasma concentrations of ondansetron at four different time points were quantified by liquid chromatography tandem mass spectrometry (LC-MS/MS). The ondansetron plasma concentrations obtained in the IV group were compared to those obtained in the OT group. The cost-effectiveness calculations included the direct costs of antiemetic prophylaxis and treatment, the use of any rescue medication and the length of hospital stay. Results: The VAS revealed that patients who were given antiemetic prophylaxis with OT ondansetron experienced less acute and delayed nausea than the patients in the IV ondansetron group; however, these differences were not statistically significant (p=0.538). Vomiting was similar in the two groups (p=1). There was a statistically significant difference between the patients and their parents in the perception of acute nausea (p=0.018), with parents overstating the level of acute nausea felt by their children. The plasma concentrations of ondansetron in patients on the IV formulation were higher than the ones in patients on the OT formulation at all the time points investigated. At 30 minutes post-dosing the mean plasma concentration of ondansetron in the IV group was significantly higher than in the OT group (p=0.0015), but the differences in plasma concentrations between the two groups from 2 hours were fairly comparable. The cost of antiemetic prophylaxis for IV ondansetron was significantly higher than the cost of antiemetic prophylaxis using the equivalent OT dose (p=0.0351). Conclusion: For the prevention of CINV, OT ondansetron, a 5HT3 receptor antagonist, proved to be an easy to use and cost-effective alternative to IV ondansetron in paediatric cancer patients receiving moderately emetogenic chemotherapy treatment.Pharmacologyunrestricte
Effects of alpha-methyldopa on the sympathetic nervous system activity in health participants
Get PDFDissertation (MSc)--University of Pretoria, 2013.Methyldopa (L-alpha-Methyl-3,4-dihydroxyphenylalanine) is a catecholamine used
as an antihypertensive agent.1 Alpha-Methyldopa is not used as frequently
anymore due to side effects, but it is still used especially in developing countries
due to its low cost. Indications are mostly for the management of pregnancyinduced
hypertension (PIH), as it is relatively safe in pregnancy compared to other
antihypertensive drugs. This project is intended to increase the already-existing
knowledge base of the mechanism of pharmacological action and to stimulate
further investigation through research.
The sympathetic nervous system is a division of the autonomic nervous system
and it is responsible for the “flight-or-fight” response. It is involuntary and constantly
active to maintain homeostasis in the human body. Sympathetic responses include
an increase in heart rate, blood pressure and cardiac output, dilation of pupils and
bronchioles, constriction of blood vessels, contraction of sphincters and inhibition
of gut motility and secretions.
The purpose of this study is to evaluate the activity of the sympathetic nervous
system of volunteers by three different techniques (QT interval and Heart rate
variability and Skin conductance) after a week of a bi-daily dosage of alphamethyldopa.
All volunteers received either 250mg alpha-methyldopa orally or a placebo tablet in
a randomized, double blind, placebo controlled study design. The correlation
between the following techniques was also evaluated: Skin conductance as
measured by the ProComp Infiniti Biofeedback apparatus, QT interval on ECG and
HRV measured with Viport apparatus. A salivary sample was collected to evaluate
the effect of alpha-methyldopa on salivary cortisol using an ELISA kit for analysis.gm2014Pharmacologyunrestricte
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The effect of Pectinex Ultra SP-L on bacterial biofilms and human cell cultures in vitro
Get PDFThesis (PhD)--University of Pretoria, 2014.Biofilms are surface-bound bacterial colonies that are held together by a self-produced extracellular polymeric matrix. They are highly resistant to antibiotics and host defence mechanisms, and are known to be the cause of persistent infections. Biofilm-degrading enzymes have been shown to prevent biofilm formation, remove mature biofilm, and enhance the efficacy of antibiotics. This study investigated the antibacterial and antibiofilm actions of the commercial enzyme Pectinex Ultra SP-L (Pectinex), alone and in combination with antibiotics, on standard and clinical cultures of Staphylococcus aureus and Pseudomonas aeruginosa. The cytotoxicity of Pectinex was determined on human cell cultures in vitro.
Pectinex (7.42 – 950 PGU/ml) was not bactericidal, and had no effect on the antibacterial efficacy of amoxicillin-clavulanate and ciprofloxacin in cultures of S. aureus (ATCC 12600) and P. aeruginosa (ATCC 9027), respectively. However, in clinical cultures of P. aeruginosa, Pectinex caused an 89.0% (from 1.0 to 1.89 μg/ml) and 92.8% (from 1.67 to 3.22 μg/ml) increase in the MIC and MBC of ciprofloxacin, respectively. In clinical cultures of S. aureus, both bactericidal indices of amoxicillin-clavulanate were increased by 28.0% (from 2.0 to 2.56 μg/ml). In all bacterial cultures, low concentrations of Pectinex (≤ 118.75 PGU/ml) and prolonged incubation periods (≥ 6 h) were both associated with increased viability and biofilm biomass. Over a short incubation period (≤ 6 h), higher concentrations of Pectinex (237.5 – 950 PGU/ml) effectively inhibited biofilm formation in P. aeruginosa ATCC (237.5 – 950 PGU/ml) and clinical (950 PGU/ml) strains but not in S. aureus cultures.
Pectinex (237.5 – 950 PGU/ml) was cytotoxic to HeLa cells, lymphocytes and neutrophils, and induced morphological features that included shrunken rounded cells, blebs, apoptotic bodies, cytoplasmic vacuoles and cell debris. The effects at 475 and 950 PGU/ml were comparable to mitomycin C 10 μg/ml and staurosporine 1 μg/ml.
Pectinex was shown to either enhance or reduce biofilm biomass and cell viability in cultures of S. aureus and P. aeruginosa. The manifested effects depended on the concentration of the enzyme, the specific bacterial species and strain, and the maturity of the biofilms. Further studies are still needed in order to determine the actions of Pectinex on other clinical pathogens.lk2014PharmacologyPhDUnrestricte
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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