Stavudine dosage reduction: Effect on symptomatic hyperlactataemia and lactic acidosis in patients at Dr George Mukhari Hospital, Pretoria

A range of studies have demonstrated that symptomatic hyperlactataemia and lactic acidosis are associated with antiretroviral combinations containing stavudine. Following a meta-analysis showing that lower doses of stavudine are safer and as effective, the World Health Organization (WHO) issued a statement that only a low dose of stavudine (30 mg) should be used. We performed a retrospective review of the records of 86 patients (aged 27 - 59 years) initiated on 30 mg or 40 mg stavudine-containing antiretroviral therapy regimens between 2004 and 2006 at the adult HIV clinic at Dr George Mukhari Hospital, Pretoria, South Africa. Our analysis demonstrated that stavudine dose reduction increased the odds of patients being more stable on treatment with fewer reported side-effects. Stavudine-containing regimens should be avoided in obese female patients. Low-dose stavudine (20 mg) may offer alternative solutions in poor or resource-limited settings, with a lower associated risk of toxicity and side-effects; however, virological non-inferiority to the first-line treatment option should be established

Scientific Letter: Stavudine dosage reduction: Effect on symptomatic hyperlactataemia and lactic acidosis in patients at Dr George Mukhari Hospital, Pretoria

Scientific Letter: No Abstrac

System Architecture for a CubeSat DTE Laser Communication System

Small satellites and CubeSats are playing an increasingly larger role in technology demonstrations, research, and obtaining data for commercial use from space. As these use cases and applications for CubeSats increase and expand the need to get fast, secure and reliable access to the data gathered by the payloads on these spacecraft also increases. To support these developments AAC Hyperion together with TNO has developed a down-to-earth laser communication module for small satellites and CubeSats with a downlink capability of 1 Gbit/s, namely CubeCAT. One of the challenges that needed to be solved to ensure success was how to deal with the pointing of the unit both for up-link and down-link purposes. Once this could be achieved the next challenge was the stability of the pointing mechanism since the pointing accuracy and stability of the laser link directly affect the link budget and achievable data rate. In other words rejection of mechanical vibrations and other disturbances. The goal of the development project was to develop such a system with a form factor and mass suitable for implementation on CubeSats. This meant that a maximum volume of 1U was set as a requirement and a maximum mass of \u3c2 kg

Infestation of Mangifera indica by the mango gall fly, Procontarinia matteiana, (Kieffer & Cecconi) (Diptera: Cecidomyiidae)

Mango gall fly (Procontarinia matteiana Kieffer&Cecconi, 1906) is an orchard pest that infests flush leaves of mango, forming wart-like structures on the leaves. Serious outbreaks may result in reduced fruit yield. A natural parasite (Chrysonotomyia pulcherimma Kerrich, 1970) of the gall fly lays its eggs inside the gall and the larvae feed on the gall fly. Mango cultivars present varying susceptibilities to gall fly infestation, with cultivars ranging from completely resistant, highly susceptible to intermediate stages where pseudo-galls are formed. The latter cultivars are ovipositioned by the gall fly, but secondary metabolites within the leaves possibly halt the development, thereby preventing the development of true galls. Microscopy was used to identify characteristic features of the gall fly and its parasite inside the gall, to study the development of the insects and to distinguish them. Evidence was obtained that the use of insecticides curbs the development of the larvae. Tissue development within true and pseudo-galls was studied to provide insights into the role of secondary plant metabolites in arresting true gall formation. This study will contribute to a more holistic approach to pest management of mango.http://www.journals.co.za/ej/ejour_ento.htmlam2013ab201

Medicinal plant cultivation for sustainable use and commercialisation of high-value crops

Many traditional healing systems are based on natural biological resources, and there is a general shift in most parts of the world towards natural medicine, with direct implications on the demand and supply of medicinal plants. This review highlights the economic importance of medicinal plants, their contribution to healthcare systems, and potential opportunities for rural economic development through cultivation.  A systematic literature review with specific search terms related to medicinal plants was used to collect scientific and non-scientific information from peer-reviewed literature and grey literature databases. The findings indicate that trade in medicinal plants is increasing, and although they are considered minor crops compared to major food crops, their value is among the highest in the list of traded plants globally. The trade also serves as a revenue source for many rural livelihoods, with women playing a significant role. Medicinal plants contribute to primary health care in many developing countries, and they are also an essential source of modern drug discovery. Cultivation of medicinal plants offers emerging rural farmers an opportunity to grow these plants as new and alternative crops, thus reducing unsustainable wild harvesting and competition with established commercial farmers who mostly focus on food crops. Furthermore, medicinal plant cultivation should be promoted as one of the options for local economic development and sustainability through job creation, the revival of the rural economy, and income generation for small businesses, such as the transport businesses, involved in the value chain. Land accessibility, financial resources, and direct market access for rural communities can elevate their contribution to the industry. Formalisation of the lower levels of the medicinal plant trade is also recommended. Significance:• Cultivation is a viable option for biodiversity conservation of medicinal plants and ensuring a goodquality supply of plant materials.• Cultivation of medicinal plants – a source of natural products used in product development – can contribute to job creation, income generation, and rural economies in developing countries.• This review underlines the importance of medicinal plants in product development, the contribution of the industry to economies of different countries, and the potential for cultivation

Chemical composition and antigenotoxic properties of Lippia alba essential oils

The present work evaluated the chemical composition and the DNA protective effect of the essential oils (EOs) from Lippia alba against bleomycin-induced genotoxicity. EO constituents were determined by Gas Chromatography/Mass Spectrometric (GC-MS) analysis. The major compounds encountered being citral (33% geranial and 25% neral), geraniol (7%) and trans-β-caryophyllene (7%) for L. alba specimen COL512077, and carvone (38%), limonene (33%) and bicyclosesquiphellandrene (8%) for the other, COL512078. The genotoxicity and antigenotoxicity of EO and the compounds citral, carvone and limonene, were assayed using the SOS Chromotest in Escherichia coli. The EOs were not genotoxic in the SOS chromotest, but one of the major compound (limonene) showed genotoxicity at doses between 97 and 1549 mM. Both EOs protected bacterial cells against bleomycin-induced genotoxicity. Antigenotoxicity in the two L. alba chemotypes was related to the major compounds, citral and carvone, respectively. The results were discussed in relation to the chemopreventive potential of L. alba EOs and its major compounds

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Recent advances in understanding hypertension development in sub-Saharan Africa

Consistent reports indicate that hypertension is a particularly common finding in black populations. Hypertension occurs at younger ages and is often more severe in terms of blood pressure levels and organ damage than in whites, resulting in a higher incidence of cardiovascular disease and mortality. This review provides an outline of recent advances in the pathophysiological understanding of blood pressure elevation and the consequences thereof in black populations in Africa. This is set against the backdrop of populations undergoing demanding and rapid demographic transition, where infection with the Human Immunodeficiency Virus predominates, and where under and over-nutrition coexist. Collectively, recent findings from Africa illustrate an increased lifetime risk to hypertension from foetal life onwards. From young ages black populations display early endothelial dysfunction, increased vascular tone and reactivity, microvascular structural adaptions, as well as increased aortic stiffness resulting in elevated central and brachial blood pressures during the day and night, when compared to whites. Together with knowledge on the contributions of sympathetic activation and abnormal renal sodium handling, these pathophysiological adaptations result in subclinical and clinical organ damage at younger ages. This overall enhanced understanding on the determinants of blood pressure elevation in blacks encourages (a) novel approaches to assess and manage hypertension in Africa better, (b) further scientific discovery to develop more effective prevention and treatment strategies, and (c) policymakers and health advocates to collectively contribute in creating health-promoting environments in Africa