27 research outputs found

    South African healthcare provider perspectives on transitioning adolescents into adult HIV care

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    Background. The first generation of South African (SA) children perinatally infected with HIV is entering adulthood, and there is now a pressing need for systematised transfer of these patients from paediatric to adult care.Objectives. Previous research has investigated the HIV healthcare transition in North America and Europe, yet none has been conducted in SA. Our study is the first to describe the perspectives of healthcare providers overseeing the transition in resource-limited settings.Methods. We approached healthcare providers working in government paediatric HIV clinics and hospitals in the Western Cape Province, SA. Seven physicians and counsellors in adolescent/paediatric care, representing five clinics, were  interviewed, and 43 completed a written survey. Interviews addressed the current state of the transition, barriers and facilitators, and model components. Interviews were assessed for major themes using framework analysis, while logistic regression was applied to survey responses to identify associations with measured covariates.Results. Analysis of interview transcripts revealed several overarching perspectives that were corroborated by survey responses. One barrier identified was the  healthcare providers’ difficulty in letting go of their relationships with the adolescent patients. Since healthcare providers regarded their patients as particularly  vulnerable, they felt a strong and protective attachment towards them. A second barrier identified was a lack of structure and effective communication between adult and paediatric providers; accordingly, healthcare providers feared that they were transferring their adolescents unprepared, to a judgemental, depersonalised and overburdened environment. All interviewees and a majority of survey respondents (>80%) agreed that the formation of adolescent support groups in adult care clinics as well as a later transition age would improve the transition process.Conclusion. This study highlights the need for a systematic healthcare transition for HIV-positive adolescents cared for in the Western Cape, while acknowledging the limitations of the current healthcare infrastructure. Several feasible   recommendations have been identified, including forming support groups and greater involvement of adolescent healthcare providers to facilitate the transition

    Review of gasless pyrotechnic time delays

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    Gasless pyrotechnic delay compositions for time‐sequencing energetic events are reviewed. They are mixtures of powdered fuels and oxidants capable of a highly exothermic oxidation‐reduction reaction. Trends favor ‘green’ compositions targeted to replace compositions containing perchlorates, chromates, lead and barium. Thermite‐based reactions dominate but intermetallics (especially multi‐layered versions) and hybrids appear promising considering progress in self‐propagating high temperature synthesis technology. Improving computer modelling will require better description of condensed phase reactions. Progress was made with the development of “hot spot” models and expressing reactivity in terms of the number of contact points (or contact surface area) between particles. Promising processing advances include mechanochemical synthesis of reactive particle composites by arrested milling or comminution of cold‐rolled multilayer intermetallics. Dry mixing of reactive powders has made way for slurry mixing followed by spray drying.AEL Mining Services (AEL/UP‐4400021845) and by the National Research Foundation (NRF) of South Africa (Grant 83874).http://www.pep.wiley-vch.de2020-01-01hj2019Chemical Engineerin

    Poly (D,L-lactide-co-glycolide) nanoparticles: Uptake by epithelial cells and cytotoxicity

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    This research article published by eXPRESS Polymer Letters Vol.8, No.3 (2014)Nanoparticles as drug delivery systems offer benefits such as protection of the encapsulated drug against degradation, site-specific targeting and prolonged blood circulation times. The aim of this study was to investigate nanoparticle uptake into Caco-2 cell monolayers, their co-localization within the lysosomal compartment and their cytotoxicity in different cell lines. Rhodamine-6G labelled poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles were prepared by a double emulsion solvent evaporation freeze-drying method. Uptake and co-localisation of PLGA nanoparticles in lysosomes were visualized by confocal laser scanning microscopy. The cytotoxicity of the nanoparticles was evaluated on different mammalian cells lines by means of Trypan blue exclusion and the MTS assay. The PLGA nanoparticles accumulated in the intercellular spaces of Caco-2 cell monolayers, but were also taken up transcellularly into the Caco-2 cells and partially co-localized within the lysosomal compartment indicating involvement of endocytosis during uptake. PLGA nanoparticles did not show cytotoxic effects in all three cell lines. Intact PLGA nanoparticles are therefore capable of moving across epithelial cell membranes partly by means of endocytosis without causing cytotoxic effects

    South African healthcare provider perspectives on transitioning adolescents into adult HIV care

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    Background. The first generation of South African (SA) children perinatally infected with HIV is entering adulthood, and there is now a pressing need for systematised transfer of these patients from paediatric to adult care.Objectives. Previous research has investigated the HIV healthcare transition in North America and Europe, yet none has been conducted in SA. Our study is the first to describe the perspectives of healthcare providers overseeing the transition in resource-limited settings.Methods. We approached healthcare providers working in government paediatric HIV clinics and hospitals in the Western Cape Province, SA. Seven physicians and counsellors in adolescent/paediatric care, representing five clinics, were interviewed, and 43 completed a written survey. Interviews addressed the current state of the transition, barriers and facilitators, and model components. Interviews were assessed for major themes using framework analysis, while logistic regression was applied to survey responses to identify associations with measured covariates.Results. Analysis of interview transcripts revealed several overarching perspectives that were corroborated by survey responses. One barrier identified was the healthcare providers’ difficulty in letting go of their relationships with the adolescent patients. Since healthcare providers regarded their patients as particularly vulnerable, they felt a strong and protective attachment towards them. A second barrier identified was a lack of structure and effective communication between adult and paediatric providers; accordingly, healthcare providers feared that they were transferring their adolescents unprepared, to a judgemental, depersonalised and overburdened environment. All interviewees and a majority of survey respondents (>80%) agreed that the formation of adolescent support groups in adult care clinics as well as a later transition age would improve the transition process.Conclusion. This study highlights the need for a systematic healthcare transition for HIV-positive adolescents cared for in the Western Cape, while acknowledging the limitations of the current healthcare infrastructure. Several feasible recommendations have been identified, including forming support groups and greater involvement of adolescent healthcare providers to facilitate the transition

    Effects of spray-drying on w/o/w multiple emulsions prepared from a stearic acid matrix

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    Nichrous Mlalila,1 Hulda Swai,2 Lonji Kalombo,2 Askwar Hilonga3 1School of Life Sciences and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania; 2Materials Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa; 3Department of Materials Science and Engineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania Abstract: The goal of this study was to explore the effects of spray-drying on w/o/w double emulsions of methyltestosterone (MT) loaded in a stearic acid matrix. MT-loaded nanoparticles were formulated by a water-in-oil-in-water emulsion technique using 50, 75, and 100 mg of stearic acid, 2% and 3% w/v polyvinyl alcohol, 5% w/v lactose, and 0.2% w/v chitosan. The emulsions were immediately spray-dried based on an optimized model of inlet temperature and pump rate, and characterized for optimized responses with regard to particle size, polydispersity index, and zeta potential, for both emulsion and powder samples. Dynamic light scattering analysis shown that the nanoparticles increased in size with increasing concentrations of polyvinyl alcohol and stearic acid. Scanning electron microscopy indicated that the MT-loaded nanoparticles were spherical in shape, had a smooth surface, and were in an amorphous state, which was confirmed by differential scanning calorimetry. These MT-loaded nanoparticles are a promising candidate carrier for the delivery of MT; however, further studies are needed in order to establish the stability of the system and the cargo release profile under normal conditions of use. Keywords: double emulsions, nanoparticles, pump rate, spray-drying, testosteron

    In vivo uptake and acute immune response to orally administered chitosan and PEG coated PLGA nanoparticles

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    Nanoparticulate drug delivery systems offer great promise in addressing challenges of drug toxicity, poor bioavailability and non-specificity for a number of drugs. Much progress has been reported for nano drug delivery systems for intravenous administration, however very little is known about the effects of orally administered nanoparticles. Furthermore, the development of nanoparticulate systems necessitates a thorough understanding of the biological response post exposure. This study aimed to elucidate the in vivo uptake of chitosan and polyethylene glycol (PEG) coated Poly, DL, lactic-co-glycolic Acid (PLGA) nanoparticles and the immunological response within 24 h of oral and peritoneal administration. These PLGA nanoparticles were administered orally and peritoneally to female Balb/C mice, they were taken up by macrophages of the peritoneum. When these particles were fluorescently labelled, intracellular localisation was observed. The expression of pro-inflammatory cytokines IL-2, IL-6, IL-12p70 and TNF-α in plasma and peritoneal lavage was found to remain at low concentration in PLGA nanoparticles treated mice as well as ZnO nanoparticles during the 24 hour period. However, these were significantly increased in lipopolysaccharide (LPS) treated mice. Of these pro-inflammatory cytokines, IL-6 and IL-12p70 were produced at the highest concentration in the positive control group. The anti-inflammatory cytokines IL-10 and chemokines INF-γ, IL-4, IL-5 remained at normal levels in PLGA treated mice. IL-10 and INF-γ were significantly increased in LPS treated mice. MCP-1 was found to be significantly produced in all groups in the first hours, except the saline treated mice. These results provide the first report to detail the induction of cytokine production by PLGA nanoparticles engineered for oral applications.South African Department of Science and Technolog

    Good treatment outcomes among foreigners receiving antiretroviral therapy in Johannesburg, South Africa.

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    Foreigners, including displaced persons, often have limited health-care access, especially to HIV services. Outcomes of antiretroviral therapy (ART) in South Africans and foreigners were compared at a Johannesburg non-governmental clinic. Records were reviewed of 1297 adults enrolled between April 2004 and March 2007 (568 self-identified foreigners, 431 South Africans citizens and 298 with unknown origin). Compared with citizens, foreigners had fewer hospital admissions (39%, 90/303 versus 51%, 126/244; P < 0.001), less missed appointments for ART initiation (20%, 39/200 versus 25%, 51/206; P < 0.001), faster median time to ART initiation (14 versus 21 days, P = 0.008), better retention in care (88%, 325/369 versus 69%, 155/226; P < 0.001) and lower mortality (2.5%, 14/568 versus 10%, 44/431; P < 0.001) after 426 person-years. In logistic regression, after controlling for baseline CD4 count and tuberculosis status, foreigners were 55% less likely to fail ART than citizens (95% CI = 0.23-0.87). These findings support United Nations High Commissioner for Refugees recommendations that ART should not be withheld from displaced persons

    Review of Gasless Pyrotechnic Time Delays

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    Gasless pyrotechnic delay compositions for time‐sequencing energetic events are reviewed. They are mixtures of powdered fuels and oxidants capable of a highly exothermic oxidation‐reduction reaction. Trends favor ‘green’ compositions targeted to replace compositions containing perchlorates, chromates, lead and barium. Thermite‐based reactions dominate but intermetallics (especially multi‐layered versions) and hybrids appear promising considering progress in self‐propagating high temperature synthesis technology. Improving computer modelling will require better description of condensed phase reactions. Progress was made with the development of “hot spot” models and expressing reactivity in terms of the number of contact points (or contact surface area) between particles. Promising processing advances include mechanochemical synthesis of reactive particle composites by arrested milling or comminution of cold‐rolled multilayer intermetallics. Dry mixing of reactive powders has made way for slurry mixing followed by spray drying.AEL Mining Services (AEL/UP‐4400021845) and by the National Research Foundation (NRF) of South Africa (Grant 83874).http://www.pep.wiley-vch.de2020-01-01hj2019Chemical Engineerin
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