56 research outputs found
Ophthalmic Anthropometry among Rural Dwellers in Mashonaland Central Province, Zimbabwe
Introduction
The measures of ophthalmic anthropometric parameters may vary among races and ethnic groups but are of immense importance in clinical diagnosis and management of oculo-visual defects. There is paucity of data on these measures among the Zimbabwean population.
Purpose
The aim was to determine ophthalmic anthropometric parameters among rural dwellers in Zimbabwe.
Methods
Six ophthalmic anthropometric parameters including interpupillary distance (IPD), head width (HW), temple width (TW), length to bend (LTB), and apical radius were measured using a pupillometer, PD rule, Head width calipers, Fairbank facial gauge, and ABDO frame rule.
Results
A total of 471 participants aged 18 to 100 years (mean age = 55.13; SD± 17.33 years). Of the 471 participants, 206 (43.7%) were males and 265 (56.3%) were females. A mean interpupillary distance at far was 65.57 ± 4.80 mm, mean temple width of 12.49 ± 1.53 cm, mean head width of 13.61 ± 1.39 cm and a side length to bend of 10.24 ± 1.20 cm and the apical radius was 9.94 ± 1.37. There was a significant (P < 0.05) difference between the ophthalmic anthropometric parameters of males and females except for temple width and apical radius.
Conclusion
A narrower interpupillary distance but a wider temple width was observed among adult Zimbabweans. A significant difference in ophthalmic anthropometric parameters between males and females were observed except for temple width and apical radius. This should inform eyewear manufacturers and importers of frames on the facial and ocular parameters of Zimbabweans to improve the aesthetics and ensure a comfortable vision for wearers of already-made near vision spectacles for presbyopes.
Rwanda J Med Health Sci 2021;4(1):99-11
Diagnostic Potential of Imaging Modalities in the Assessment of Lower Urinary Tract Dysfunctions
Lower urinary tract dysfunction (LUTD) is common in both men and women, and the incidence and prevalence increases as people age. Commonly observed symptoms of LUTD include nocturia, urgency, urinary incontinence and frequency of voiding. Recognizing the key role accurate monitoring and evaluation of LUTD play in the day-to-day assessment of the condition, this chapter will explore the diagnostic capabilities of imaging modalities including MRI, ultrasound and fluoroscopy in assessing bladder wall thickness (BWT), detrusor wall thickness (DWT) and estimation of bladder weight both in real-time and static positions, and finally analyze their suitability as surrogates for bladder outlet obstruction (BOO) or detrusor overactivity (DO)
Electromagnetic Method and Vertical Electrical Sounding for Groundwater Potential Assessment of Kintampo North Municipality of Ghana
Electromagnetic (EM) profiling and Vertical Electrical Sounding (VES) of electrical resistivity method have been employed to explore for groundwater in the Kintampo-North Municipality in the Brong Ahafo Region of Ghana. The EM profiling data were obtained with GEONICS EM 34-3 equipment at 20 m intervals along 20 profiles of length ranging between 70 to 240 m to determine conductive anomalous zones for further investigation within the unconsolidated overburden and/or water-bearing fissures in the bedrock. Subsequently, using the ABEM Terrameter, VES employing the Schlumberger electrode configuration was carried out at previously selected 53 promising anomalous points on the EM profiles. The modelled VES data using RES1DINV software revealed a number of subsurface layers and their corresponding apparent resistivity values and thicknesses. The results indicated that the EM terrain conductivity anomaly in the study area varied in the range 6-87 m mhos/m with the average and maximum apparent conductivity values of 48.5 and 76 m mhos/m respectively. The VES revealed three to four-layered lithological subsurface sequence, indicating decreasing apparent resistivity with depth. This depicted the general trend of ρ1< ρ2>> ρ3≤ ρ4, where ρ1, ρ2, ρ3 and ρ4 are the apparent resistivity of the layers 1, 2, 3 and 4 respectively. The results further showed that both the average apparent resistivity and thickness of layers 1, 2, 3 and 4 are respectively 368 Ωm, 3.9 m; 435 Ωm, 17 m; 50 Ωm, 53.5 m and 332 Ωm, >53.5 m. Thus aquifer zones were estimated to be located between 15-30 m depth. These layers were inferred to be the sandy-clay topsoil, weathered/fractured layer and the fresh bedrock. However, the weathered layer and the fractured basement constituted the aquifer zones across the study area within the Voltaian Sedimentary Basin, which is otherwise regarded as a difficult area in locating groundwater resources. Keywords: Groundwater potential, aquifer, apparent resistivity, terrain conductivit
Epigenetic potentiation of somatostatin-2 by guadecitabine in neuroendocrine neoplasias as a novel method to allow delivery of peptide receptor radiotherapy
Background Somatostatin receptor-2 (SSTR2) is expressed on cell surface of neuroendocrine neoplasias; its presence is exploited for the delivery of peptide receptor radionuclide therapy (PRRT). Patients with no or low expression of SSTR2 are not candidates for PRRT. SSTR2 promotor undergoes epigenetic modification, known to regulate gene expression. We investigated whether the demethylation agent, guadecitabine, could enhance the expression of SSTR2 in NET models, using radioligand uptake/PET imaging as a biomarker of epigenetic modification. Methods The effects of guadecitabine on the transcriptional, translational, and functional regulation of SSTR2 both in vitro and in vivo using low (QGP-1) and high (BON-1) methylated neuroendocrine neoplasia models was characterised. Promotor region methylation profiling of clinical samples (n = 61) was undertaken. Safety of combination guadecitabine and PRRT was assessed in vivo. Results Pyrosequencing of cell lines illustrated differential methylation indices – BON: 1 94%, QGP: 1 21%. Following guadecitabine treatment, a dose-dependent increase in SSTR2 in BON-1 at a transcriptional, translational, and functional levels using the SSTR2-directed radioligand, 18F-FET-βAG-TOCA ([18F]-FETO) (150% increase [18F]-FETO uptake, p < 0.05) was observed. In vivo, guadecitabine treatment resulted in a 70% increase in [18F]-FETO uptake in BON-1 tumour models compared models with low baseline percentage methylation (p < 0.05). No additive toxicity was observed with the combination treatment of PRRT and guadecitabine in vivo. Methylation index in clinical samples was 10.5% compared to 5.2% in controls (p = 0.03) and correlated with SSTR2 expression (Wilcoxon rank sign −3.75,p < 0.01). Conclusion Guadecitabine increases SSTR2 expression both in vitro and in vivo. The combination of demethylation agents with PRRT warrants further investigation
In vivo evaluation of [18F]fluoroetanidazole as a new marker for imaging tumour hypoxia with positron emission tomography
Development of hypoxia-targeted therapies has stimulated the search for clinically applicable noninvasive markers of tumour hypoxia. Here, we describe the validation of [18F]fluoroetanidazole ([18F]FETA) as a tumour hypoxia marker by positron emission tomography (PET). Cellular transport and retention of [18F]FETA were determined in vitro under air vs nitrogen. Biodistribution and metabolism of the radiotracer were determined in mice bearing MCF-7, RIF-1, EMT6, HT1080/26.6, and HT1080/1-3C xenografts. Dynamic PET imaging was performed on a dedicated small animal scanner. [18F]FETA, with an octanol–water partition coefficient of 0.16±0.01, was selectively retained by RIF-1 cells under hypoxia compared to air (3.4- to 4.3-fold at 60–120 min). The radiotracer was stable in the plasma and distributed well to all the tissues studied. The 60-min tumour/muscle ratios positively correlated with the percentage of pO2 values <5 mmHg (r=0.805, P=0.027) and carbogen breathing decreased [18F]FETA-derived radioactivity levels (P=0.028). In contrast, nitroreductase activity did not influence accumulation. Tumours were sufficiently visualised by PET imaging within 30–60 min. Higher fractional retention of [18F]FETA in HT1080/1-3C vs HT1080/26.6 tumours determined by dynamic PET imaging (P=0.05) reflected higher percentage of pO2 values <1 mmHg (P=0.023), lower vessel density (P=0.026), and higher radiobiological hypoxic fraction (P=0.008) of the HT1080/1-3C tumours. In conclusion, [18F]FETA shows hypoxia-dependent tumour retention and is, thus, a promising PET marker that warrants clinical evaluation
Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer
INTRODUCTION
Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice.
METHODS
More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer 'stem' cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account.
RESULTS
The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working.
CONCLUSIONS
With resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years
Tick communities of cattle in smallholder rural livestock production systems in sub-Saharan Africa
AVAILABILITY OF DATA AND MATERIALS : The datasets generated and/or analysed during the current study are not publicly available due to Contract Research Organization agreements (data will be stored in the archives of Clinglobal, Mauritius), but are available from the corresponding author on reasonable request.CHANGE HISTORY : 12 November 2023. This article has been corrected since original publication.
16 November 2023. A Correction to this paper has been published: https://doi.org/10.1186/s13071-023-06034-2
09 August 2023. A Correction to this paper has been published: https://doi.org/10.1186/s13071-023-05895-xADDITIONAL FILE 1: TABLE S1.
Spatio-temporal variation in tick prevalence in cattle of seven sub-Saharan countries. TABLE S2. Spatio-temporal variation in tick loads in cattle of seven sub-Saharan countries. TABLE S3. and TABLE S4. Distribution of (co-) infestations in cattle individuals.ADDITIONAL FILE 2 : Protocol.BACKGROUND : The majority of the African population lives in rural areas and depends on agriculture for their livelihoods. To increase the productivity and sustainability of their farms, they need access to affordable yield-enhancing inputs of which parasite control is of paramount importance. We therefore determined the status of current tick species with the highest economic impact on cattle by sampling representative numbers of animals in each of seven sub-Saharan countries.
METHODS : Data included tick species’ half-body counts from approximately 120 cattle at each of two districts per country, collected four times in approximately 1 year (to include seasonality). Study sites were chosen in each country to include high cattle density and tick burden.
RESULTS : East Africa (Ethiopia, Uganda and Tanzania) showed overall a higher diversity and prevalence in tick infestations compared to West African countries (Benin, Burkina Faso, Ghana and Nigeria). In East Africa, Amblyomma variegatum (vector of Ehrlichia ruminantium), Rhipicephalus microplus (Babesia bovis, B. bigemina, Anaplasma marginale), R. evertsi evertsi (A. marginale) and R. appendiculatus (Theileria parva) were the most prevalent tick species of economic importance. While the latter species was absent in West Africa, here both A. variegatum and R. microplus occurred in high numbers. Rhipicephalus microplus had spread to Uganda, infesting half of the cattle sampled. Rhipicephalus microplus is known for its invasive behaviour and displacement of other blue tick species, as observed in other East and West African countries. Individual cattle with higher body weights, as well as males, were more likely to be infested. For six tick species, we found reduced infestation levels when hosts were treated with anti-parasiticides.
CONCLUSIONS : These baseline data allow the determination of possible changes in presence and prevalence of ticks in each of the countries targeted, which is of importance in the light of human-caused climate and habitat alterations or anthropogenic activities. As many of the ticks in this study are vectors of important pathogens, but also, as cattle may act as end hosts for ticks of importance to human health, our study will help a wide range of stakeholders to provide recommendations for tick infestation surveillance and prevention.The Bill & Melinda Gates Foundation (BMGF).https://parasitesandvectors.biomedcentral.comhj2024Veterinary Tropical DiseasesSDG-02:Zero Hunge
Recommendations for environmental risk assessment of gene drive applications for malaria vector control
This is the final version. Available on open access from BMC via the DOI in this record. Building on an exercise that identified potential harms from simulated investigational releases of a population suppression gene drive for malaria vector control, a series of online workshops identified nine recommendations to advance future environmental risk assessment of gene drive applications.Bill and Melinda Gates FoundationOpen Philanthrop
Acaricide resistance status of livestock ticks from East and West Africa and in vivo efficacy of acaricides to control them
Through a collaborative effort across six Sub-Saharan African countries, using recognized international assessment techniques, 23 stocks of three tick species (Rhipicephalus microplus, Rhipicephalus appendiculatus and Amblyomma variegatum) of economic importance for rural small holder farming communities from East and West Africa were collected from cattle, and evaluated in in vitro larval packet tests (LPT). The results demonstrated medium to high resistance to chlorfenvinphos and amitraz across species. Rhipicephalus microplus demonstrated high level alpha-cypermethrin and cypermethrin resistance. Stocks of A. variegatum (West Africa) and R. appendiculatus (Uganda) demonstrated medium level ivermectin resistance.
The four least susceptible stocks (East and West African R. microplus, A. variegatum and R. appendiculatus) were taken into in vivo controlled cattle studies where fipronil was found effective against West and East African R. microplus isolates although persistent efficacy failed to reach 90%. Cymiazole and cypermethrin, and ivermectin based acaricides were partially effective against R. microplus without persistent efficacy. Flumethrin spray-on killed A. variegatum within 72 h for up to 10 days posttreatment, however product application was directly to tick attachment sites, which may be impractical under field conditions. A flumethrin pour-on formulation on goats provided persistent efficacy against A. variegatum for up to one-month. Therapeutic control was achieved against R. appendiculatus through weekly spraying cattle with flumethrin, amitraz or combined cymiazole and cypermethrin. A fipronil pour-on product offered four-week residual control against R. appendiculatus (with slow onset of action).
Few studies have assessed and directly compared acaricidal activity in vitro and in vivo. There was some discordance between efficacy indicated by LPT and in vivo results. This observation calls for more research into accurate and affordable assessment methods for acaricide resistance.
No single active or product was effective against all three tick species, emphasising the need for the development of alternative integrated tick management solutions.The BMGF and a Bill & Melinda Gates Foundation (BMGF) supported project.https://www.elsevier.com/locate/ijpddrhj2024Veterinary Tropical DiseasesSDG-02:Zero HungerSDG-03:Good heatlh and well-bein
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