Infant health: a community-based assessment and educational intervention in two rural communities in the Eastern Cape.
- Authors: Kuzeeko, Faith
- Date: 2021
- Subjects: Angus Gillis Foundation (South Africa) , Infants -- Mortality -- South Africa , Infants -- Health and hygiene -- South Africa , Breastfeeding -- South Africa -- Eastern Cape , Infants -- Care -- Equipment and supplies , Infants -- Care -- South Africa -- Eastern Cape -- Case studies , Children -- Mortality -- South Africa , High throughput screening (Drug development)
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/170837 , vital:41964
- Description: South Africa is on track to attaining the 2030 Agenda on reducing under-five deaths to 25 deaths per 1000 live births at its current momentum, however an unacceptable amount of infants are still at risk from preventable illnesses. Malnutrition is the major underlined cause of infant mortality rates in South Africa. Exclusive breastfeeding rates are low nationwide due to low exposure to breastfeeding information, some mothers having other commitments and others having breastfeeding difficulties. Implementation and expansion of simple, cost-effective interventions, such as exclusive breastfeeding for six months to reduce and/or prevent infant mortality rates, remains low in South Africa. The aim of the study was to determine one infant health issue of major concern to participants in two rural villages in the Eastern Cape, namely Glenmore and Ndwayana. The identified infant health issue was used to design an educational intervention in the villages. This was the second phase of this study. A community-based participatory approach was utilized in which the Angus Gillis Foundation, a non-profit organization that works in these communities, was one of the stakeholders. Stock status of WHO priority medicines for infants, semi-structured interviews and focus group discussions were carried out during the baseline study. The intervention phase contained pre-2 intervention semi-structured interviews with ten pregnant women followed by an educational intervention with nine out of the ten; and finally, a post-intervention with seven out of the ten women. A questionnaire was completed by members of the Angus Gillis Foundation to provide feedback on the sustainability of the intervention. Semi-structured interviews revealed that medicines stocked at the clinic parallel those indicated in the WHO priority medicines list for infants. The results from the focus group discussions indicated that mothers do not exclusively breastfeed their infants during the first six months. Pre- and post-intervention results on exclusive breastfeeding illustrated a positive change in participants’ knowledge and intent to breastfeed exclusively for six months. They showed a better understanding of the importance of exclusive breastfeeding and indicated a more focussed intention and confidence to carry out optimal breastfeeding practices. In the questionnaire the members of the Angus Gillis Foundation stated that the intervention is sustainable as it was linked with the existing networks. These include educational programs carried out in the villages by the foundation together with positive health champions, community health workers and women self-help groups; which will be able to build on the present knowledge base. Finally, the study also included the design of a booklet on the identified infant health issue. In conclusion, participants highlighted lack of understanding regarding breastfeeding as an issue of concern during the baseline phase of the study. This community-based educational intervention improved the understanding of breastfeeding among the participants, resulting in a positive change in perception with regards to exclusive breastfeeding practices.
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- Date Issued: 2021
Application of quality by design to the manufacture of a multiparticulate prednisone dosage form
- Authors: Manda, Arthur
- Date: 2020-04
- Subjects: Drugs -- Quality control , Drugs -- Design -- Quality control , Drugs -- Dosage forms , Drug development -- Quality control , Pharmaceutical industry -- Quality control , Prednisone , High throughput screening (Drug development)
- Language: English
- Type: text , Thesis , Masters , MSc (Pharmacy)
- Identifier: http://hdl.handle.net/10962/117986 , vital:34583
- Description: For many years, quality by testing was the only approach to guarantee quality of drug products before the Food and Drug Administration launched the concept of current Good Manufacturing Practice. In order to gain more knowledge of the manufacturing process, a new system known as Quality by Design was introduced into the pharmaceutical industry. Quality by Design is based on thorough understanding of how materials, process parameters and interaction thereof impact final product quality. Quality by Design is a systematic approach to product development which ensures that quality is built into a product during product development and not just tested into it. The aim of Quality by Design is to achieve optimum product quality with consistent dosage form performance and minimal risk of failure in patients. The objective of these studies was to implement a Quality by Design approach to establish a design space for the development and manufacture of a safe, effective and stable multi-partite solid oral dosage form for prednisone as an alternative to currently marketed prednisone formulations. Multi-particulate dosage forms offer significant advantages over conventional technologies. In addition to lowering the incidence of gastrointestinal irritation they exhibit a reduced risk of dose dumping and a large surface area which favours dissolution. Furthermore, their free flowing nature facilitates reproducible capsule filling and consequently uniformity of dosing. Different multi-particulate dosage forms exist however a multiple-unit pellet system was investigated during these studies. Quality by Design principles were used to develop and establish a reversed-phase high performance liquid chromatographic method for quantifying prednisone from solid oral dosage forms. A Central Composite Design was used to generate multivariate experiments and to investigate the impact of input variables on the quality and performance of the analytical method. The optimized method was validated according to International Council for Harmonization guidelines and was found to be linear, precise, accurate and specific for the quantitation of prednisone. Pre-formulation studies were conducted and included the assessment of particle size, particle shape, powder flow properties and compatibility studies. Carr’s index, Hausner ratio and the Angle of Repose were used to evaluate powder flow properties and results generated from all studies suggest the need for adding a glidant and lubricant to improve pellet flow. The images generated from Scanning Electron Microscopy were used to analyze particle shape and size. Differential Scanning Calorimetry and Fourier Transform Infrared Spectroscopy were used to evaluate API-excipient compatibility. All excipients investigated were found to be compatible with prednisone and suitable for formulation development studies. Extrusion-spheronization was used to manufacture prednisone pellets. Extrusion-spheronization is a multi-step process involving many factors. Quality risk management tools particularly an Ishikawa Fishbone (cause and effect) diagram and failure mode and effects analysis were used to narrow down potentially significant factors to a reasonable number that could be investigated experimentally. Risk priority numbers were used to quantify risk and factors above a set threshold value were considered to be of high risk. A total of eleven risk factors were identified as high. A Plackett-Burman study was conducted to narrow down the eleven high risk factors to identify the most impactful factors viz., microcrystalline cellulose content, sodium starch glycolate content, extrusion speed and spheronization time. Evaluation of four factors was carried over to optimization studies using a Box-Behnken Design and following identifaction of the optimum process settings and excipient content a design space for the manufacture of a multi-partite dosage form containing prednisone was established.
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- Date Issued: 2020-04
Cyclooxygenase-1 as an anti-stroke target: potential inhibitor identification and non-synonymous single nucleotide polymorphism analysis
- Authors: Muronzi, Tendai
- Date: 2020
- Subjects: Cerebrovascular disease , Cerebrovascular disease -- Treatment , Cerebrovascular disease -- Chemotherapy , Cyclooxygenases , High throughput screening (Drug development) , Drug development , Molecular dynamics , South African Natural Compounds Database , ZINC database
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/143404 , vital:38243
- Description: Stroke is the third leading cause of death worldwide, with 87% of cases being ischemic stroke. The two primary therapeutic strategies to reduce post-ischemic brain damage are cellular and vascular approaches. The vascular strategy aims to rapidly re-open obstructed blood vessels, while the cellular approach aims to interfere with the signalling pathways that facilitate neuron damage and death. Unfortunately, popular vascular treatments have adverse side effects, necessitating the need for alternative chemotherapeutics. In this study, cyclooxygenase-1 (COX-1), which plays a significant role in the post- ischemic neuroinflammation and neuronal death, was targeted for identification of novel drug compounds and to assess the effect of nsSNPs on its structure and function. In a drug discovery part, ligands from the South African Natural Compounds Database (SANCDB-https://sancdb.rubi.ru.ac.za/) and ZINC database (http://zinc15.docking.org/) were used for high-throughput virtual screening (HVTS) against COX-1. Additionally, five nsSNPs were being investigated to assess their impact on protein structure and function. Three of these SNPs were in the COX-1 dimer interface. Molecular docking and molecular dynamics simulations revealed asymmetric nature of the protein. Several ligands, peculiar to each monomer, exhibited favourable binding energies in the respective active sites. SNP analysis indicated effects on inter-monomer interactions and protein stability.
- Full Text:
- Date Issued: 2020
Investigating assay formats for screening malaria Hsp90-Hop interaction inhibitors
- Authors: Derry, Leigh-Anne Tracy Kim
- Date: 2019
- Subjects: Antimalarials , Heat shock proteins , Drug interactions , Drug resistance , Plasmodium falciparum , High throughput screening (Drug development) , Bioluminescence resonance energy transfer (BRET) , Fluorescence resonance energy transfer (FRET)
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/63345 , vital:28395
- Description: Although significant gains have been made in the combat against malaria in the last decade, the persistent threat of drug and insecticide resistance continues to motivate the search for new classes of antimalarial drug compounds and targets. Due to their predominance in cellular reactions, protein-protein interactions (P-PIs) are emerging as a promising general target class for therapeutic development. The P-PI which is the focus of this project is the interaction between the chaperone heat shock protein 90 (Hsp90) and its co-chaperone Hsp70/Hsp90 organising protein (Hop). Hop binds to Hsp70 and Hsp90 and facilitates the transfer of client proteins (proteins undergoing folding) from the former to the latter and also regulates nucleotide exchange on Hsp90. Due to its role in correcting protein misfolding during cell stress, Hsp90 is being pursued as a cancer drug target and compounds that inhibit its ATPase activity have entered clinical trials. However, it has been proposed that inhibiting the interaction between Hsp90 and Hop may be alternative approach for inhibiting Hsp90 function for cancer therapy. The malaria parasite Plasmodium falciparum experiences temperature fluctuations during vector-host transitions and febrile episodes and cell stress due to rapid growth and immune responses. Hence, it also depends on chaperones, including PfHsp90, to maintain protein functionality and pathogenesis, demonstrated inter alia by the sensitivity of parasites to Hsp90 inhibitors. In addition, PfHsp90 exists as a complex with the malarial Hop homologue, PfHop, in parasite lysates. Consequently, the purpose of this study was to explore P-PI assay formats that can confirm the interaction of PfHsp90 and PfHop and can be used to identify inhibitors of the interaction, preferably in a medium- to high-throughput screening mode. As a first approach, cell-based bioluminescence and fluorescence resonance energy transfer (BRET and FRET) assays were performed in HeLa cells. To facilitate this, expression plasmid constructs containing coding sequences of P. falciparum and mammalian Hsp90 and Hop and their interacting domains (Hsp90 C-domain and Hop TPR2A domain) fused to the BRET and FRET reporter proteins – yellow fluorescent protein (YFP), cyan fluorescent protein (CFP) and Renilla luciferase (Rluc) - were prepared and used for HeLa cell transient transfections. The FRET assay produced positive interaction signals for the full-length P. falciparum and mammalian Hsp90-Hop interactions. However, C-domain-TPR2A domain interactions were not detected, no interactions could be demonstrated with the BRET assay and western blotting experiments failed to detect expression of all the interaction partners in transiently transfected HeLa cells. Consequently, an alternative in vitro FRET assay format using recombinant proteins was investigated. Expression constructs for the P. falciparum and mammalian C-domains and TPR2A domains fused respectively to YFP and CFP were prepared and the corresponding fusion proteins expressed and purified from E. coli. No interaction was found with the mammalian interaction partners, but interaction of the P. falciparum C-domain and TPR2A domain was consistently detected with a robust Z’ factor value of 0.54. A peptide corresponding to the PfTPR2A domain sequence primarily responsible for Hsp90 binding (based on a human TPR2A peptide described by Horibe et al., 2011) was designed and showed dose-dependent inhibition of the interaction, with 53.7% inhibition at 100 μM. The components of the assay are limited to the purified recombinant proteins, requires minimal liquid steps and may thus be a useful primary screening format for identifying inhibitors of P. falciparum Hsp90-Hop interaction.
- Full Text:
- Date Issued: 2019