Identification of Surrogate Anatomic Identifiers of Disease Progression in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss in patients over 50 in the developed world. The visual impairment is due to either choroidal neovascularisation (wet AMD) or geographic atrophy (GA). Drusen is the hallmark of AMD but the presence of drusen does not inform progression to wet AMD. Although the disease is mostly bilateral, the rate of progression of disease in both eyes may not be simultaneous. If one eye is affected by wet AMD, the risk of progression of the fellow eye to wet AMD increases by 10% every year. However, there are no markers that inform the time of conversion to wet AMD. For this reason, there is an unmet need to identify biomarkers that can fully predict the progression to wet AMD in order to allow early intervention before permanent damage. My thesis aimed to assess whether changes in imaging characteristics can more precisely explain conversion. I studied various cohorts including (a) normal aging eyes (b) eyes with early/ intermediate AMD and (c) fellow eyes of unilateral wet AMD to study the conversion to wet AMD. Firstly, I evaluated longitudinally volume changes in inner and outer retinal layers of 71 eyes with early/intermediate AMD using optical coherence tomography (OCT). Our results showed that inner and outer retina layer volumes may differentiate AMD eyes from healthy eyes. When comparing those who progressed to wet AMD at year 2 to those who did not, we found that baseline volume of GCIPL may differentiate between the 2 groups. As it is an inner retinal change, I hypothesized that heritability of the retinal layers may influence the rate of retinal layer changes and that may in turn help understand the changes seen in aging and AMD. I worked with the TWIN Study database, in which OCT was done in eyes of twins of different age groups and OCT data were available on 364 eyes of 184 (92 pair) twins. I evaluated whether heritability was responsible for ageing changes of the retinal layers. I found that total retinal volume and inner retinal layer volumes may be affected by genetic factors

ЭКСПЕРИМЕНТАЛЬНАЯ ОЦЕНКА ИЗНОСА МОДЕРНИЗИРОВАННОЙ ПРИВОДНОЙ РОЛИКОВОЙ ЦЕПИ

Analysis of mechanical drives groups in agricultural machines identifies relatively narrow range of types of transmission and units. Chain transmission are mainly used as mechanical drive of assemblies and units in grain and corn harvesters designs. Transmission roller chains are used in Vector 425, Acros 585, Torum 780 harvesters produced by combine plant «Rostselmash». The links wear during operation leads to relative elongation of middle chain pitch and reduction of reliability of the mechanical drive. To improve the drive reliability the authors proposed upgraded roller drive chain. Inserts are placed inside the hinges and form cavity for accommodating and retaining the lubricant, which guarantees lubrication of contacting surfaces of chain transmission during operation. Сomparative laboratory tests were carried out to study the relative elongation of the middle pitch of commercial and modernized chains. The authors presented experimental data and dependences of relative elongation of chains average pitch on the duration of the operation, which are approximated by second order polynomial. The speed of relative elongation of middle pitch of commercial chains is by 2.17 times more than of modernized one. The proposed modernization of the drive roller chain to perform the required set of functions without the redistribution between the elements and increase their functional load should be considered as functional redundancy to increase the reliability of the drive in the mechanical systems of agricultural purposes.Анализ узлов механических приводов сельскохозяйственной техники выявил относительно узкий спектр передач и узлов. В конструкциях зерноуборочных и кукурузоуборочных комбайнов в качестве механических приводов узлов и агрегатов в основном предусмотрены цепные передачи. В комбайнах Vector 425, Acros 585, Torum 780, выпускаемых на заводе компании «Ростсельмаш», используют приводные роликовые цепи. Износ их звеньев в процессе эксплуатации приводит к относительному удлинению среднего шага цепи и снижению надежности механического привода. Для повышения надежности привода предложили модернизированную приводную роликовую цепь. Внутри ее шарниров установлены вкладыши, образующие полость для размещения и удержания смазочного материала, что гарантирует непрерывную смазку контактирующих поверхностей цепной передачи в процессе эксплуатации. Провели сравнительные лабораторные исследования относительного удлинения среднего шага серийной и модернизированной цепей. Представили экспериментальные данные и зависимости относительного удлинения среднего шага цепей от продолжительности работы, которые аппроксимируются полиномом второй степени. Установили, что скорость относительного удлинения среднего шага серийной цепи превышает этот показатель модернизированной цепи в 2,17 раза. Предложенную модернизацию приводной роликовой цепи для выполнения требуемого набора функций без перераспределения между элементами и увеличения их функциональной нагрузки следует рассматривать как функциональное резервирование с целью повышения надежности привода механических систем сельскохозяйственного назначения

Attitudes toward home-based malaria testing in rural and urban Sierra Leone

Background The purpose of this study was to examine malaria testing practices and preferences in Bo, Sierra Leone, and to ascertain interest in and willingness to take a home-based rapid diagnostic test administered by a community health volunteer (CHV) or a trained family member rather than travelling to a clinical facility for laboratory-based testing. Methods A population-based, cross-sectional survey of 667 randomly-sampled rural households and 157 urban households was conducted in December 2013 and January 2014. Results Among rural residents, 69% preferred a self/family- or CHV-conducted home-based malaria test and 20% preferred a laboratory-based test (with others indicating no preference). Among urban residents, these numbers were 38% and 44%, respectively. If offered a home-based test, 28% of rural residents would prefer a self/family-conducted test and 68% would prefer a CHV-assisted test. For urban residents, these numbers were 21% and 77%. In total, 36% of rural and 63% of urban residents reported usually taking a diagnostic test to confirm suspected malaria. The most common reasons for not seeking malaria testing were the cost of testing, waiting to see if the fever resolved on its own, and not wanting to travel to a clinical facility for a test. In total, 32% of rural and 27% of urban participants were very confident they could perform a malaria test on themselves or a family member without assistance, 50% of rural and 62% of urban participants were very confident they could perform a test after training, and 56% of rural and 33% of urban participants said they would pay more for a home-based test than a laboratory-based test. Conclusion Expanding community case management of malaria to include home testing by CHVs and family members may increase the proportion of individuals with febrile illnesses who confirm a positive diagnosis prior to initiating treatment

Identification of Subsets of Enteroaggregative Escherichia coli Associated with Diarrheal Disease among Under 5 Years of Age Children from Rural Gambia.

Enteroaggregative Escherichia coli (EAEC) cause acute and persistent diarrhea, mostly in children worldwide. Outbreaks of diarrhea caused by EAEC have been described, including a large outbreak caused by a Shiga toxin expressing strain. This study investigated the association of EAEC virulence factors with diarrhea in children less than 5 years. We characterized 428 EAEC strains isolated from stool samples obtained from moderate-to-severe diarrhea cases (157) and healthy controls (217) children aged 0-59 months recruited over 3 years as part of the Global Enteric Multicenter Study (GEMS) in The Gambia. Four sets of multiplex polymerase chain reaction were applied to detect 21 EAEC-virulence genes from confirmed EAEC strains that target pCVD432 (aatA) and AAIC (aaiC). In addition, Kirby-Bauer disc diffusion antimicrobial susceptibility testing was performed on 88 EAEC strains following Clinical Laboratory Standard Institute guidelines. We observed that the plasmid-encoded enterotoxin [odds ratio (OR): 6.9, 95% confidence interval (CI): 2.06-29.20, P 12 months). Our data suggest that some EAEC-virulent factors have age-specific associations with moderate-to-severe diarrhea in infants. Furthermore, our study showed that 85% and 72% of EAEC strains tested were resistant to sulphamethoxazole-trimethoprim and ampicillin, respectively. Sulphamethoxazole-trimethoprim and ampicillin are among the first-line antibiotics used for the treatment of diarrhea in The Gambia

Impact of the COVID-19 pandemic on the coverage and timeliness of routine childhood vaccinations in the Gambia, 2015-2021

INTRODUCTION: The COVID-19 pandemic caused widespread morbidity and mortality and resulted in the biggest setback in routine vaccinations in three decades. Data on the impact of the pandemic on immunisation in Africa are limited, in part, due to low-quality routine or administrative data. This study examined coverage and timeliness of routine childhood immunisation during the pandemic in The Gambia, a country with an immunisation system considered robust. METHODS: We obtained prospective birth cohort data of 57 286 children in over 300 communities in two health and demographic surveillance system sites, including data from the pre-pandemic period (January 2015-February 2020) and the three waves of the pandemic period (March 2020-December 2021). We determined monthly coverage and timeliness (early and delayed) of the birth dose of hepatitis B vaccine (HepB0) and the first dose of pentavalent vaccine (Penta1) during the different waves of the pandemic relative to the pre-pandemic period. We implemented a binomial interrupted time-series regression model. RESULT: We observed no significant change in the coverage of HepB0 and Penta1 vaccinations from the pre-pandemic period up until the periods before the peaks of the first and second waves of the pandemic in 2020. However, there was an increase in HepB0 coverage before as well as after the peak of the third wave in 2021 compared with the pre-pandemic period (pre-third wave peak OR = 1.83, 95% CI 1.06 to 3.14; post-third wave period OR=2.20, 95% CI 1.23 to 3.92). There was some evidence that vaccination timeliness changed during specific periods of the pandemic. Early Penta1 vaccination decreased by 70% (OR=0.30, 95% CI 0.12 to 0.78) in the period before the second wave, and delayed HepB0 vaccination decreased by 47% (OR=0.53, 95% CI 0.29 to 0.97) after the peak of the third wave in 2021. CONCLUSION: Despite the challenges of the COVID-19 pandemic, The Gambia's routine vaccination programme has defied the setbacks witnessed in other settings and remained resilient, with coverage increasing and timeliness improving during the second and third waves. These findings highlight the importance of having adequate surveillance systems to monitor the impact of large shocks to vaccination coverage and timeliness

The factors affecting household transmission dynamics and community compliance with Ebola control measures: a mixed-methods study in a rural village in Sierra Leone.

BACKGROUND: Little is understood of Ebola virus disease (EVD) transmission dynamics and community compliance with control measures over time. Understanding these interactions is essential if interventions are to be effective in future outbreaks. We conducted a mixed-methods study to explore these factors in a rural village that experienced sustained EVD transmission in Kailahun District, Sierra Leone. METHODS: We reconstructed transmission dynamics using a cross-sectional survey conducted in April 2015, and cross-referenced our results with surveillance, burial, and Ebola Management Centre (EMC) data. Factors associated with EVD transmission were assessed with Cox proportional hazards regression. Following the survey, qualitative semi-structured interviews explored views of community informants and households. RESULTS: All households (n = 240; 1161 individuals) participated in the survey. 29 of 31 EVD probable/confirmed cases died (93·5% case fatality rate); six deaths (20·6%) had been missed by other surveillance systems. Transmission over five generations lasted 16 weeks. Although most households had ≤5 members there was a significant increase in risk of Ebola in households with > 5 members. Risk of EVD was also associated with older age. Cases were spatially clustered; all occurred in 15 households. EVD transmission was better understood when the community experience started to concord with public health messages being given. Perceptions of contact tracing changed from invading privacy and selling people to ensuring community safety. Burials in plastic bags, without female attendants or prayer, were perceived as dishonourable. Further reasons for low compliance were low EMC survival rates, family perceptions of a moral duty to provide care to relatives, poor communication with the EMC, and loss of livelihoods due to quarantine. Compliance with response measures increased only after the second generation, coinciding with the implementation of restrictive by-laws, return of the first survivor, reduced contact with dead bodies, and admission of patients to the EMC. CONCLUSIONS: Transmission occurred primarily in a few large households, with prolonged transmission and a high death toll. Return of a survivor to the village and more effective implementation of control strategies coincided with increased compliance to control measures, with few subsequent cases. We propose key recommendations for management of EVD outbreaks based on this experience

mRNA Levels of Placental Iron and Zinc Transporter Genes Are Upregulated in Gambian Women with Low Iron and Zinc Status.

Background: The role of the placenta in regulating micronutrient transport in response to maternal status is poorly understood.Objective: We investigated the effect of prenatal nutritional supplementation on the regulation of placental iron and zinc transport.Methods: In a randomized trial in rural Gambia [ENID (Early Nutrition and Immune Development)], pregnant women were allocated to 1 of 4 nutritional intervention arms: 1) iron and folic acid (FeFol) tablets (FeFol group); 2) multiple micronutrient (MMN) tablets (MMN group); 3) protein energy (PE) as a lipid-based nutrient supplement (LNS; PE group); and 4) PE and MMN (PE+MMN group) as LNS. All arms included iron (60 mg/d) and folic acid (400 μg/d). The MMN and PE+MMN arms included 30 mg supplemental Zn/d. In a subgroup of ∼300 mother-infant pairs, we measured maternal iron status, mRNA levels of genes encoding for placental iron and zinc transport proteins, and cord blood iron levels.Results: Maternal plasma iron concentration in late pregnancy was 45% and 78% lower in the PE and PE+MMN groups compared to the FeFol and MMN groups, respectively (P < 0.001). The mRNA levels of the placental iron uptake protein transferrin receptor 1 were 30-49% higher in the PE and PE+MMN arms than in the FeFol arm (P < 0.031), and also higher in the PE+MMN arm (29%; P = 0.042) than in the MMN arm. Ferritin in infant cord blood was 18-22% lower in the LNS groups (P < 0.024). Zinc supplementation in the MMN arm was associated with higher maternal plasma zinc concentrations (10% increase; P < 0.001) than in other intervention arms. mRNA levels for intracellular zinc-uptake proteins, in this case zrt, irt-like protein (ZIP) 4 and ZIP8, were 96-205% lower in the PE+MMN arm than in the intervention arms without added zinc (P < 0.025). Furthermore, mRNA expression of ZIP1 was 85% lower in the PE+MMN group than in the PE group (P = 0.003).Conclusion: In conditions of low maternal iron and in the absence of supplemental zinc, the placenta upregulates the gene expression of iron and zinc uptake proteins, presumably in order to meet fetal demands in the face of low maternal supply. The ENID trial was registered at www.controlled-trials.com as ISRCTN49285450

Starstruck: Wash and Dry Sneakers Cleaner / Marsha Elsie Biddulph Mohd Shahzan Biddulph ...[et al.]

Starstruck Clean Sdn. Bhd. offers our products and services for customers, providing the variety of machine that gives high satisfaction of consumer. Our client is customers identifying as students and teenagers who want consume product with affordable price of product. We also targeting busiest workers because we have fast services of our product to customer at home. Starstruck Clean offers a variety of shoes cleaning machine that give customers option to buy the product based on their requirement

Barriers and enablers to kangaroo mother care prior to stability from perspectives of Gambian health workers: A qualitative study.

Aims: Kangaroo mother care (KMC) is an evidence-based intervention recommended for stable newborns <2,000 g. Recent trials have investigated survival benefits of earlier initiation of KMC, including prior to stability, with WHO's iKMC trial showing 25% relative risk reduction for mortality of neonates 1-1.8 kg at tertiary Indian and African neonatal units (NNU). However, evidence is lacking about how to safely deliver this intervention to the most vulnerable neonates in resource limited settings (RLS). Our study aimed to understand barriers and enablers for early KMC prior to stability from perspectives of neonatal health care workers (HCW) in a high neonatal mortality RLS. Methods: This qualitative study was conducted at Edward Francis Small Teaching Hospital (EFSTH), the main neonatal referral unit in The Gambia. It was ancillary study to the eKMC clinical trial. Ten semi-structured interviews were conducted with all neonatal HCW cadres (4 nurses; 1 nurse attendant; 5 doctors; all Gambian). Study participants were purposively selected, and saturation was reached. Thematic analysis was conducted using Atun's conceptual framework for evaluation of new health interventions with methods to ensure data reliability and trustworthiness. Results: HCW's perceptions of early KMC prior to stability included recognition of potential benefits as well as uncertainty about effectiveness and safety. Barriers included: Unavailability of mothers during early neonatal unit admission; safety concerns with concomitant intravenous fluids and impact on infection prevention control; insufficient beds, space, WASH facilities and staffing; and lack of privacy and respectful care. Enablers included: Education of HCW with knowledge transfer to KMC providers; paternal and community sensitization and peer-to-peer support. Conclusions: Addressing health systems limitations for delivery of KMC prior to stability is foundational with linkage to comprehensive HCW and KMC provider education about effectiveness, safe delivery and monitoring. Further context specific research into safe and respectful implementation is required from varied settings and should include perceptions of all stakeholders, especially if there is a shift in global policy toward KMC for all small vulnerable newborns

Manipulating transcription factors in human induced pluripotent cell-derived cells to enhance the production and the maturation of red blood cells

The most widely transfused blood component is red blood cells (RBCs), and voluntary donation is the main resource for RBC transfusion. In the UK, 7,000 units of RBCs are transfused daily but this life-saving cell therapy is completely dependent on donors and there are persistent problems associated with transfusion transmitted infections and in blood group compatibility. Furthermore, the quality, safety and efficiency of donated RBCs gradually decrease with storage time. A number of novel sources of RBCs are being explored including the production of RBCs from adult haematopoietic progenitor cells, erythroid progenitor cell lines and induced pluripotent stem cells (iPSCs). The iPSC source could essentially provide a limitless supply and a route to producing cells that are matched to the recipient. A number of protocols have been described to produce mature RBCs from human pluripotent stem cells but they are relatively inefficient and would be difficult to scale up to the levels required for clinical translation. We tested and evaluated a defined feeder- and serum-free differentiation protocol for deriving erythroid cells from hiPSCs. RBC production was not efficient, the cells that were produced did not enucleate efficiently and they expressed embryonic rather than adult globin. We hypothesised that the production of RBCs from iPSCs could be enhanced by enforced expression of erythroid-specific transcription factors (TFs). Previous studies had demonstrated that Krüppel-like factor 1 (KLF1) plays an important role in RBC development and maturation so we generated iPSC lines expressing a tamoxifen-inducible KLF1-ERT2 fusion protein. Using zinc finger nuclease technology, we targeted the expression cassette to the AAVS1 locus to ensure consistent expression levels and to avoid integration site specific effects and/or silencing. These iKLF1 iPSCs were applied to our defined RBC differentiation protocol and the activity of KLF1 was induced by adding tamoxifen. Activation of KLF1 from day 10 accelerated erythroid differentiation and maturation with an increase in the proportion of erythroblasts, a higher level of expression of erythroid genes associated with maturation and an apparently more robust morphology. However, KLF1 activation had an anti-proliferation effect resulting in significantly less cell generated overall and HPLC analysis demonstrated that KLF1-activated cells expressed higher levels of embryonic globin compared to control iPSCs-derived cells. Many of the effects that were observed when KLF1 was activated from day 10 were not observed when activated from day 18. We therefore concluded that activation of exogenous KLF1 is able to promote erythroid cell production and maturation in progenitors (day 10) but not at the later stage of erythropoiesis (day 18). We hypothesised that KLF1 might require a co-factor to regulate RBC maturation and adult globin expression at the later stage of erythropoiesis. The TF, B-cell lymphoma/leukaemia 11a (BCL11A), plays a key role in the suppression of foetal globin expression, thereby completing globin switching to adult globin. Preliminary data showed that iPSC-derived erythroid cells were able to express adult globin when transduced with a BCL11A-expressing lentiviral-vector. Based on that finding we then generated an iPSC line expressing tamoxifen-inducible BCL11AERT2 and KLF1-ERT2 fusion proteins, applied this iBK iPSC line to our differentiation protocol. Activation of both TFs from day 18 slightly increased the expression of genes associated with RBC maturation and the inclusion of BCL11A appeared to eliminate the anti-proliferation effect of KLF1. Most importantly, activation of both BCL11A and KLF1 from day 18 of the differentiation protocol increased the production of α- globin (foetal / adult globin) indicating that some definitive-like erythroid cells might be generated by activation of both TFs at the later stage of erythroid differentiation. Collectively, these findings demonstrate that enforced expression of erythroid TFs could be a useful strategy to enhance RBC maturation from iPSCs