A new indole alkaloid and other constituents from Monodora minor and Uvaria tanzaniae: their antitrypanosomal and antiplasmodial evaluation
- Christopher, Robert, Mgani, Quintino A, Nyandoro, Stephen S, Rousseau, Amanda L, Isaacs, Michelle, Hoppe, Heinrich C
- Authors: Christopher, Robert , Mgani, Quintino A , Nyandoro, Stephen S , Rousseau, Amanda L , Isaacs, Michelle , Hoppe, Heinrich C
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429347 , vital:72603 , xlink:href="https://doi.org/10.1080/14786419.2019.1710705"
- Description: Phytochemical investigation of the methanolic extract of Monodora minor Engl. and Diels (Annonaceae) stem bark yielded a new indole (E)-4-(1H-indol-5-yl)-but-3-en-2-one (1), a known indole 5-formyl-1H-indole (2) and an ubiquitous steroid sitosterol (3). The investigations of the methanolic extract of Uvaria tanzaniae Verdc. (Annonaceae) root bark yielded two previously reported C-benzylated dihydrochalcones namely uvaretin (4) and diuvaretin (5). Structures of the isolated compounds were elucidated based on NMR spectroscopy and high resolution electron ionization mass spectrometry (HR-EI-MS) data. All compounds were tested against Trypanosoma brucei brucei and Plasmodium falciparum. At a single concentration (20 μM) in the antitrypanosomal and antiplasmodial assays, compound 4 exhibited remarkable activities against T. brucei brucei and P. falciparum with percentage inhibition of 97.3% and 83.0% respectively, whereas compounds 1, 2, 3 and 5 were inactive. In a dose response antiplasmodial assay compound 4 exhibited moderate activity against P. falciparum with an IC50 value of 7.20 μM.
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- Authors: Christopher, Robert , Mgani, Quintino A , Nyandoro, Stephen S , Rousseau, Amanda L , Isaacs, Michelle , Hoppe, Heinrich C
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429347 , vital:72603 , xlink:href="https://doi.org/10.1080/14786419.2019.1710705"
- Description: Phytochemical investigation of the methanolic extract of Monodora minor Engl. and Diels (Annonaceae) stem bark yielded a new indole (E)-4-(1H-indol-5-yl)-but-3-en-2-one (1), a known indole 5-formyl-1H-indole (2) and an ubiquitous steroid sitosterol (3). The investigations of the methanolic extract of Uvaria tanzaniae Verdc. (Annonaceae) root bark yielded two previously reported C-benzylated dihydrochalcones namely uvaretin (4) and diuvaretin (5). Structures of the isolated compounds were elucidated based on NMR spectroscopy and high resolution electron ionization mass spectrometry (HR-EI-MS) data. All compounds were tested against Trypanosoma brucei brucei and Plasmodium falciparum. At a single concentration (20 μM) in the antitrypanosomal and antiplasmodial assays, compound 4 exhibited remarkable activities against T. brucei brucei and P. falciparum with percentage inhibition of 97.3% and 83.0% respectively, whereas compounds 1, 2, 3 and 5 were inactive. In a dose response antiplasmodial assay compound 4 exhibited moderate activity against P. falciparum with an IC50 value of 7.20 μM.
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AMBER force field parameters for the Zn (II) ions of the tunneling-fold enzymes GTP cyclohydrolase I and 6-pyruvoyl tetrahydropterin synthase
- Khairallah, Afrah, Tastan Bishop, Özlem, Moses, Vuyani
- Authors: Khairallah, Afrah , Tastan Bishop, Özlem , Moses, Vuyani
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429360 , vital:72604 , xlink:href="https://doi.org/10.1080/07391102.2020.1796800"
- Description: The folate biosynthesis pathway is an essential pathway for cell growth and survival. Folate derivatives serve as a source of the one-carbon units in several intracellular metabolic reactions. Rapidly dividing cells rely heavily on the availability of folate derivatives for their proliferation. As a result, drugs targeting this pathway have shown to be effective against tumor cells and pathogens, but drug resistance against the available antifolate drugs emerged quickly. Therefore, there is a need to develop new treatment strategies and identify alternative metabolic targets. The two de novo folate biosynthesis pathway enzymes, GTP cyclohydrolase I (GCH1) and 6-pyruvoyl tetrahydropterin synthase (PTPS), can provide an alternative strategy to overcome the drug resistance that emerged in the two primary targeted enzymes dihydrofolate reductase and dihydropteroate synthase. Both GCH1 and PTPS enzymes contain Zn2+ ions in their active sites, and to accurately study their dynamic behaviors using all-atom molecular dynamics (MD) simulations, appropriate parameters that can describe their metal sites should be developed and validated. In this study, force field parameters of the GCH1 and PTPS metal centers were generated using quantum mechanics (QM) calculations and then validated through MD simulations to ensure their accuracy in describing and maintaining the Zn2+ ion coordination environment. The derived force field parameters will provide accurate and reliable MD simulations involving these two enzymes for future in-silico identification of drug candidates against the GCH1 and PTPS enzymes.
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- Authors: Khairallah, Afrah , Tastan Bishop, Özlem , Moses, Vuyani
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429360 , vital:72604 , xlink:href="https://doi.org/10.1080/07391102.2020.1796800"
- Description: The folate biosynthesis pathway is an essential pathway for cell growth and survival. Folate derivatives serve as a source of the one-carbon units in several intracellular metabolic reactions. Rapidly dividing cells rely heavily on the availability of folate derivatives for their proliferation. As a result, drugs targeting this pathway have shown to be effective against tumor cells and pathogens, but drug resistance against the available antifolate drugs emerged quickly. Therefore, there is a need to develop new treatment strategies and identify alternative metabolic targets. The two de novo folate biosynthesis pathway enzymes, GTP cyclohydrolase I (GCH1) and 6-pyruvoyl tetrahydropterin synthase (PTPS), can provide an alternative strategy to overcome the drug resistance that emerged in the two primary targeted enzymes dihydrofolate reductase and dihydropteroate synthase. Both GCH1 and PTPS enzymes contain Zn2+ ions in their active sites, and to accurately study their dynamic behaviors using all-atom molecular dynamics (MD) simulations, appropriate parameters that can describe their metal sites should be developed and validated. In this study, force field parameters of the GCH1 and PTPS metal centers were generated using quantum mechanics (QM) calculations and then validated through MD simulations to ensure their accuracy in describing and maintaining the Zn2+ ion coordination environment. The derived force field parameters will provide accurate and reliable MD simulations involving these two enzymes for future in-silico identification of drug candidates against the GCH1 and PTPS enzymes.
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Biological control potential of ectomycorrhizal fungi against Fusarium circinatum on Pinus patula seedlings
- Chartier FitzGerald, Veronique C, Dames, Joanna F, Hawley, Grant L
- Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Grant L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425960 , vital:72302 , xlink:href="https://doi.org/10.1080/09583157.2020.1771542"
- Description: The South Africa forestry industry, covering ∼1.3 million hectares, is dependent on exotic pine and Eucalyptus species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi or other beneficial microbes. Fusarium circinatum is an economically important pathogen affecting seedling survival. The purpose of this investigation was to assess the effects of ectomycorrhizal fungal inoculation on Pinus patula seedling growth and resistance to the fungal pathogen F. circinatum. Explants from ECM basidiocarps, collected from Pinus stands, were plated onto MMN medium to obtain isolates that were then verified via DNA extraction and PCR amplification and sequencing of the ITS rDNA region. These isolates were identified as Boletus edulis f. reticulatus, Lactarius quieticolor, Suillus granulatus and an unknown Suillus species. P. patula growth in the presence of the pathogen F. circinatum was significantly increased and promoted by the L. quieticolor and Suillus isolates. Preventative inoculation of seedlings in the nursery using these isolates would ensure the production of stronger, healthier plants that would be more resistant to F. circinatum infection, increasing survival in the plantation.
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- Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Grant L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/425960 , vital:72302 , xlink:href="https://doi.org/10.1080/09583157.2020.1771542"
- Description: The South Africa forestry industry, covering ∼1.3 million hectares, is dependent on exotic pine and Eucalyptus species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi or other beneficial microbes. Fusarium circinatum is an economically important pathogen affecting seedling survival. The purpose of this investigation was to assess the effects of ectomycorrhizal fungal inoculation on Pinus patula seedling growth and resistance to the fungal pathogen F. circinatum. Explants from ECM basidiocarps, collected from Pinus stands, were plated onto MMN medium to obtain isolates that were then verified via DNA extraction and PCR amplification and sequencing of the ITS rDNA region. These isolates were identified as Boletus edulis f. reticulatus, Lactarius quieticolor, Suillus granulatus and an unknown Suillus species. P. patula growth in the presence of the pathogen F. circinatum was significantly increased and promoted by the L. quieticolor and Suillus isolates. Preventative inoculation of seedlings in the nursery using these isolates would ensure the production of stronger, healthier plants that would be more resistant to F. circinatum infection, increasing survival in the plantation.
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Environmental health promotion at a National Science Festival: An experiential-education based approach
- Duxbury, Theodore O, Bradshaw, Karen L, Khamanga, Sandile, Tandlich, Roman, Srinivas, Sunitha C
- Authors: Duxbury, Theodore O , Bradshaw, Karen L , Khamanga, Sandile , Tandlich, Roman , Srinivas, Sunitha C
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440274 , vital:73762 , xlink:href="https://doi.org/10.1080/1533015X.2019.1567406"
- Description: To increase individual and communal environmental health awareness through an experiential-education project. A computer-based pre- and postintervention quiz; an educational poster; an interactive board game; and a take-home information leaflet were utilized for a school learners-centered health promotion exhibit at a National Science Festival in Grahamstown, South Africa. Out of all the participants, 55.7% were female, and 76.5% attended or had attended a government school. Participants showed significant improvement in their pre- and post educational intervention. The exhibit was effective in educating participants on environmental health, natural resources, and the impact environmental pollution has on their quality of life.
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- Authors: Duxbury, Theodore O , Bradshaw, Karen L , Khamanga, Sandile , Tandlich, Roman , Srinivas, Sunitha C
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440274 , vital:73762 , xlink:href="https://doi.org/10.1080/1533015X.2019.1567406"
- Description: To increase individual and communal environmental health awareness through an experiential-education project. A computer-based pre- and postintervention quiz; an educational poster; an interactive board game; and a take-home information leaflet were utilized for a school learners-centered health promotion exhibit at a National Science Festival in Grahamstown, South Africa. Out of all the participants, 55.7% were female, and 76.5% attended or had attended a government school. Participants showed significant improvement in their pre- and post educational intervention. The exhibit was effective in educating participants on environmental health, natural resources, and the impact environmental pollution has on their quality of life.
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Life after training: Professional experiences of early career clinical and counselling psychologists in South Africa
- Haine, Phillipa, Booysen, Duane D
- Authors: Haine, Phillipa , Booysen, Duane D
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450703 , vital:74975 , xlink:href="https://doi.org/10.1080/14330237.2020.1821317"
- Description: We aimed to gain an in-depth understanding of the lived professional experiences of early career clinical and counselling psychologists in South Africa. Our informants were four early career psychologists (females = 2, males = 2; clinical = 2, counselling = 2; period in service = 1 to 7 years). They completed semi-structured interviews on their critical early career professional experiences, as well as the meanings they attributed to these experiences. Interpretative phenomenological analysis of the data yielded four super-ordinate themes: (i) training as a ‘rite of passage’; (ii) expectations for a professional future; (iii) entering the professional psychology workspace; and (iv) future career directions. Findings suggest employment opportunities in the healthcare system to influence the professional socialisation of early career psychologists in addition to their personal choices. Systemic factors appear to explain why South African psychologists would opt to practice privately, and why debates on the profession’s relevance, accessibility, and credibility may continue unabated.
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- Authors: Haine, Phillipa , Booysen, Duane D
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450703 , vital:74975 , xlink:href="https://doi.org/10.1080/14330237.2020.1821317"
- Description: We aimed to gain an in-depth understanding of the lived professional experiences of early career clinical and counselling psychologists in South Africa. Our informants were four early career psychologists (females = 2, males = 2; clinical = 2, counselling = 2; period in service = 1 to 7 years). They completed semi-structured interviews on their critical early career professional experiences, as well as the meanings they attributed to these experiences. Interpretative phenomenological analysis of the data yielded four super-ordinate themes: (i) training as a ‘rite of passage’; (ii) expectations for a professional future; (iii) entering the professional psychology workspace; and (iv) future career directions. Findings suggest employment opportunities in the healthcare system to influence the professional socialisation of early career psychologists in addition to their personal choices. Systemic factors appear to explain why South African psychologists would opt to practice privately, and why debates on the profession’s relevance, accessibility, and credibility may continue unabated.
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Resisting abortion stigma in situ: South African womxn's and healthcare providers' accounts of the pre-abortion counselling healthcare encounter
- Mavuso, Jabulile M-J J, Macleod, Catriona I
- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443749 , vital:74149 , xlink:href="https://doi.org/10.1080/13691058.2019.1674922"
- Description: Abortion providers and pregnant people who undergo abortion potentially face significant stigma. Researchers have started to explore how womxn respond to abortion stigma, usually focusing on individual strategies in managing or reducing stigma effects. Drawing on narrative data from research conducted on womxn’s and healthcare providers’ experiences of the pre-abortion healthcare encounter in the South African public health sector, we highlight how stigma may be resisted in social ways within this context. Everyday chatter and informal social support amongst womxn in the waiting room provided a counterpoint for health service providers’ ascription of shame to the womxn, and a sense of solidarity amongst the womxn. Health service providers narrated their decision to do abortion work through the socially affirming hero canonical narrative, and womxn described their counselling as helpful. These social and discursive practices resist the awfulisation of abortion and provide relief for the womxn and the healthcare providers in particular contexts.
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- Authors: Mavuso, Jabulile M-J J , Macleod, Catriona I
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443749 , vital:74149 , xlink:href="https://doi.org/10.1080/13691058.2019.1674922"
- Description: Abortion providers and pregnant people who undergo abortion potentially face significant stigma. Researchers have started to explore how womxn respond to abortion stigma, usually focusing on individual strategies in managing or reducing stigma effects. Drawing on narrative data from research conducted on womxn’s and healthcare providers’ experiences of the pre-abortion healthcare encounter in the South African public health sector, we highlight how stigma may be resisted in social ways within this context. Everyday chatter and informal social support amongst womxn in the waiting room provided a counterpoint for health service providers’ ascription of shame to the womxn, and a sense of solidarity amongst the womxn. Health service providers narrated their decision to do abortion work through the socially affirming hero canonical narrative, and womxn described their counselling as helpful. These social and discursive practices resist the awfulisation of abortion and provide relief for the womxn and the healthcare providers in particular contexts.
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Transforming environmental health practitioners’ knowledge-sharing practices through inter-agency formative intervention workshops
- Masilela, Priscilla, Olvitt, Lausanne L
- Authors: Masilela, Priscilla , Olvitt, Lausanne L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372809 , vital:66624 , xlink:href="https://doi.org/10.1080/0158037X.2020.1717458"
- Description: Home-based care facilities provide basic healthcare services to people too sick or frail to access formal clinics and hospitals. These facilities produce ‘healthcare risk waste’ which must be managed responsibly, and it is the work of Environmental Health Practitioners working within municipalities to ensure that the waste produced by home-based care facilities is managed in line with legislation. This paper presents a case study of a twenty-seven-month expansive learning intervention in a South African municipality that sought to transform its healthcare risk waste management practices. Limited knowledge and inadequate knowledge-sharing practices were identified as the main hindrances to effective waste management. The practitioner-researcher facilitated a series of inter-agency, formative intervention workshops with municipal employees and Community Health Workers using the Developmental Work Research methodology. These workshops strengthened both groups of practitioners’ knowledge of the ‘who, how, what, why and when’ that underpins effective healthcare risk waste management, and enabled ‘boundary crossing’ for practitioners to work across their specialist areas towards co-defining and analysing problems and constructing new solutions.
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- Authors: Masilela, Priscilla , Olvitt, Lausanne L
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/372809 , vital:66624 , xlink:href="https://doi.org/10.1080/0158037X.2020.1717458"
- Description: Home-based care facilities provide basic healthcare services to people too sick or frail to access formal clinics and hospitals. These facilities produce ‘healthcare risk waste’ which must be managed responsibly, and it is the work of Environmental Health Practitioners working within municipalities to ensure that the waste produced by home-based care facilities is managed in line with legislation. This paper presents a case study of a twenty-seven-month expansive learning intervention in a South African municipality that sought to transform its healthcare risk waste management practices. Limited knowledge and inadequate knowledge-sharing practices were identified as the main hindrances to effective waste management. The practitioner-researcher facilitated a series of inter-agency, formative intervention workshops with municipal employees and Community Health Workers using the Developmental Work Research methodology. These workshops strengthened both groups of practitioners’ knowledge of the ‘who, how, what, why and when’ that underpins effective healthcare risk waste management, and enabled ‘boundary crossing’ for practitioners to work across their specialist areas towards co-defining and analysing problems and constructing new solutions.
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