20 research outputs found
In vitro embryo rescue and plant regeneration following self-pollination with irradiated pollen in cassava (Manihot esculenta Crantz)
Cassava is a highly heterozygous species; hence, current methods used in classical cassava breedingcannot match the urgent need to high yielding varieties. Recently, progress was made through androgenesis and gynogenesis as pathways for raising doubled cassava haploid lines to overcome problems associated with cassavaâs inherent reproductive biology, but these efforts were limited (nocandidate cassava plantlets were regenerated). For the first time, this study shows that pollen irradiation coupled with self-pollination and embryo rescue regenerated 62 candidate cassava plantlets. Plants of an elite cassava variety, Nase14, served as a mother plant and as the pollen donor for the irradiation. Irradiation dosages of 50 to 250 Gray studied across five pollination events and 300 or 500 Gray in one pollination event caused a reduction in pollen germination up to 67.0%. By 15 days after pollination (DAP) with irradiated pollen, up to 89.7% of the pollinated flowers had aborted. By embryo rescue time (42 DAP), significant differences were observed in number of fruits, seeds and embryos generated, with the non-irradiated pollen treatments having significantly higher numbers. Sixteen (16) heterozygous SSR markers in the parent and ploidy analysis showed that none of the regenerated plants was haploid or homozygous. However, the plantlets resulting from pollination with non-irradiated pollen had 56.2% homozygous loci, while progeny derived from irradiated treatments had frequencies of homozygous loci between 28.1 and 55.0%. This is the first time to use irradiated pollen in cassava as a pathway to generate candidate plantlets as an initial step in double haploid production.Key words: Cassava, doubled haploids, embryo rescue, plant regeneration, pollen germination, pollenirradiation
The costâeffectiveness of prophylaxis strategies for individuals with advanced HIV starting treatment in Africa
Introduction Many HIVâpositive individuals in Africa have advanced disease when initiating antiretroviral therapy (ART) so have high risks of opportunistic infections and death. The REALITY trial found that an enhancedâprophylaxis package including fluconazole reduced mortality by 27% in individuals starting ART with CD4 <100 cells/mm3. We investigated the costâeffectiveness of this enhancedâprophylaxis package versus other strategies, including using cryptococcal antigen (CrAg) testing, in individuals with CD4 <200 cells/mm3 or <100 cells/mm3 at ART initiation and all individuals regardless of CD4 count. Methods The REALITY trial enrolled from June 2013 to April 2015. A decisionâanalytic model was developed to estimate the costâeffectiveness of six management strategies in individuals initiating ART in the REALITY trial countries. Strategies included standardâprophylaxis, enhancedâprophylaxis, standardâprophylaxis with fluconazole; and three CrAg testing strategies, the first stratifying individuals to enhancedâprophylaxis (CrAgâpositive) or standardâprophylaxis (CrAgânegative), the second to enhancedâprophylaxis (CrAgâpositive) or enhancedâprophylaxis without fluconazole (CrAgânegative) and the third to standardâprophylaxis with fluconazole (CrAgâpositive) or without fluconazole (CrAgânegative). The model estimated costs, lifeâyears and qualityâadjusted lifeâyears (QALY) over 48 weeks using three competing mortality risks: cryptococcal meningitis; tuberculosis, serious bacterial infection or other known cause; and unknown cause. Results Enhancedâprophylaxis was costâeffective at costâeffectiveness thresholds of US500 per QALY with an incremental costâeffectiveness ratio (ICER) of US113 per QALY in the CD4 <100 cells/mm3 population) and increased in all individuals regardless of CD4 count (US2.30. Conclusions The REALITY enhancedâprophylaxis package in individuals with advanced HIV starting ART reduces morbidity and mortality, is practical to administer and is costâeffective. Efforts should continue to ensure that components are accessed at lowest available prices
Late Presentation With HIV in Africa: Phenotypes, Risk, and Risk Stratification in the REALITY Trial.
This article has been accepted for publication in Clinical Infectious Diseases Published by Oxford University PressBackground: Severely immunocompromised human immunodeficiency virus (HIV)-infected individuals have high mortality shortly after starting antiretroviral therapy (ART). We investigated predictors of early mortality and "late presenter" phenotypes. Methods: The Reduction of EArly MortaLITY (REALITY) trial enrolled ART-naive adults and children â„5 years of age with CD4 counts .1). Results: Among 1711 included participants, 203 (12%) died. Mortality was independently higher with older age; lower CD4 count, albumin, hemoglobin, and grip strength; presence of World Health Organization stage 3/4 weight loss, fever, or vomiting; and problems with mobility or self-care at baseline (all P < .04). Receiving enhanced antimicrobial prophylaxis independently reduced mortality (P = .02). Of five late-presenter phenotypes, Group 1 (n = 355) had highest mortality (25%; median CD4 count, 28 cells/”L), with high symptom burden, weight loss, poor mobility, and low albumin and hemoglobin. Group 2 (n = 394; 11% mortality; 43 cells/”L) also had weight loss, with high white cell, platelet, and neutrophil counts suggesting underlying inflammation/infection. Group 3 (n = 218; 10% mortality) had low CD4 counts (27 cells/”L), but low symptom burden and maintained fat mass. The remaining groups had 4%-6% mortality. Conclusions: Clinical and laboratory features identified groups with highest mortality following ART initiation. A screening tool could identify patients with low CD4 counts for prioritizing same-day ART initiation, enhanced prophylaxis, and intensive follow-up. Clinical Trials Registration: ISRCTN43622374.REALITY was funded by the Joint Global Health Trials Scheme (JGHTS) of the UK Department for International Development, the Wellcome Trust, and Medical Research Council (MRC) (grant number G1100693). Additional funding support was provided by the PENTA Foundation and core support to the MRC Clinical Trials Unit at University College London (grant numbers MC_UU_12023/23 and MC_UU_12023/26). Cipla Ltd, Gilead Sciences, ViiV Healthcare/GlaxoSmithKline, and Merck Sharp & Dohme donated drugs for REALITY, and ready-to-use supplementary food was purchased from Valid International. A. J. P. is funded by the Wellcome Trust (grant number 108065/Z/15/Z). J. A. B. is funded by the JGHTS (grant number MR/M007367/1). The Malawi-LiverpoolâWellcome Trust Clinical Research Programme, University of Malawi College of Medicine (grant number 101113/Z/13/Z) and the Kenya Medical Research Institute (KEMRI)/Wellcome Trust Research Programme, Kilifi (grant number 203077/Z/16/Z) are supported by strategic awards from the Wellcome Trust, United Kingdom. Permission to publish was granted by the Director of KEMRI. This supplement was supported by funds from the Bill & Melinda Gates Foundation
Eye diseases among kitchen staff in Senior High Schools in the Kumasi Metropolis
Fuel wood smoke is known to be associated with a number of ocular diseases such as cataract, pterygium and dry eye syndrome amongst others. A descriptive cross-sectional study was carried out on 290 kitchen staff in senior secondary schools in the Kumasi metropolis to identify the type of fuel and cooking stoves used and the ocular pathologies affecting them. Ocular examinations were performed on the kitchen staff. The study included administration of questionnaire, clinical and ocular history taking, visual acuity measurements, external eye examination, ophthalmoscopy,and Schirmerâs tear function test. The study revealed that 22.1% of the respondents had worked in the kitchens for a period of over twenty years. The major ocular complaints found amongst the 290 respondents were itching eyes (50.3%) and excessive tearing (40.3%). Majority (75.2%) of the kitchen staff were suffering from one or more eye diseases. The commonest ocular diseases were dry eyes (46.6%) pterygium (31.1%) and corneal ulcer (8.3%). All (100%) of the schools used firewood as their primary source of fuel. Most (76.9%) of the schools however used Liquefied Petroleum Gas (LPG) to cook certain kinds of meals. Ventilation was poor in 53.9% of the schools visited. Very smoky kitchens were seen in 84.6% of the schools. In conclusion, it was observed that the Kitchen staff of Senior High Schools in the Kumasi Metropolis areat high risk of developing eye diseases that may be attributed to the working environment
Estimating medium- and long-term trends in malaria transmission by using serological markers of malaria exposure
The implementation and evaluation of malaria control programs would be greatly facilitated by new tools for the rapid assessment of malaria transmission intensity. Because acquisition and maintenance of antimalarial antibodies depend on exposure to malaria infection, such antibodies might be used as proxy measures of transmission intensity. We have compared the prevalence of IgG antibodies with three Plasmodium falciparum asexual stage antigens in individuals of all ages living at varying altitudes encompassing a range of transmission intensities from hyper- to hypoendemic in northeastern Tanzania, with alternative measures of transmission intensity. The prevalence of antibodies to merozoite surface protein-1(19) was significantly more closely correlated with altitude than either point-prevalence malaria parasitemia or single measures of hemoglobin concentration. Analysis of age-specific seroprevalence rates enabled differentiation of recent (seasonal) changes in transmission intensity from longer-term transmission trends and, using a mathematical model of the annual rate of seroconversion, estimation of the longevity of the antibody response. Thus, serological tools allow us to detect variations in malaria transmission over time. Such tools will be invaluable for monitoring trends in malaria endemicity and the effectiveness of malaria control programs
Mucoceles gigantes: visĂŁo neurocirĂșrgica. Relato de dois casos Giant mucoceles: neurosurgical view. Report of two cases
SĂŁo apresentados dois casos de mucocele gigante do seio frontal submetidos a tratamento cirĂșrgico. A manifestação clĂnica foi cefalĂ©ia de evolução prolongada, associada com protrusĂŁo unilateral do globo ocular de curta duração. Em ambos os casos foi realizada craniotomia frontal com remoção completa da lesĂŁo, reparação do soalho frontal com retalho pediculado de gĂĄlea e cranialização do seio frontal. No segundo caso, uma abordagem endoscĂłpica intranasal foi combinada Ă abordagem externa no mesmo ato cirĂșrgico. Alguns aspectos abordando a etiologia, associação com outras afecçÔes e tratamento cirĂșrgico sĂŁo discutidos.<br>Two patients harboring giant frontal mucoceles are reported. In both cases complaints of chronic headaches and progressive unilateral proptosis were preponderant. Surgical treatment included a frontal craniotomy with excision of the lesion, skull base reinforcement with pedicled galea and wide opening of the frontal sinuses. In the second case an intranasal endoscopic approach was combined with craniotomy at the same surgical operative time. Some aspects regarding etiology, association with other diseases and some surgical aspects are discussed