Elastin haploinsufficiency accelerates age-related structural and functional changes in the renal microvasculature and impairment of renal hemodynamics in female mice

Age-related decline in functional elastin is associated with increased arterial stiffness, a known risk factor for developing cardiovascular disease. While the contribution of elastin insufficiency to the stiffening of conduit arteries is well described, little is known about the impact on the structure and function of the resistance vasculature, which contributes to total peripheral resistance and the regulation of organ perfusion. In this study, we determined how elastin insufficiency impinges on age-related changes in the structure and biomechanical properties of the renal microvasculature, altering renal hemodynamics and the response of the renal vascular bed to changes in renal perfusion pressure (RPP) in female mice. Using Doppler ultrasonography, we found that resistive index and pulsatility index were elevated in young Eln+/− and aged mice. Histological examination showed thinner internal and external elastic laminae, accompanied by increased elastin fragmentation in the medial layer without any calcium deposits in the small intrarenal arteries of kidneys from young Eln+/− and aged mice. Pressure myography of interlobar arteries showed that vessels from young Eln+/− and aged mice had a slight decrease in distensibility during pressure loading but a substantial decline in vascular recoil efficiency upon pressure unloading. To examine whether structural changes in the renal microvasculature influenced renal hemodynamics, we clamped neurohumoral input and increased renal perfusion pressure by simultaneously occluding the superior mesenteric and celiac arteries. Increased renal perfusion pressure caused robust changes in blood pressure in all groups; however, changes in renal vascular resistance and renal blood flow (RBF) were blunted in young Eln+/− and aged mice, accompanied by decreased autoregulatory index, indicating greater impairment of renal autoregulation. Finally, increased pulse pressure in aged Eln+/− mice positively correlated with high renal blood flow. Together, our data show that the loss of elastin negatively affects the structural and functional integrity of the renal microvasculature, ultimately worsening age-related decline in kidney function

Changing patterns of the prevalence of Helicobacter pylori among patients at a corporate hospital in Ghana

Introduction: Helicobacter pylori (H. pylori) discovered in 1982, has strongly been associated with multiple clinical disorders of the gastrointestinal tract. This study described the prevalence of H. pylori among large numbers of patients over two different time periods in Accra, Ghana.Methods: It was a retrospective records review on patients attending a quasi-government hospital in Accra, Ghana, during two time periods, 1999 and 2012. A total of 2401 records were reviewed, 1128 in first period and 1273 in second period. Biopsy was taken from the gastric antrum for Rapid Urease Test (RUT) in identifying H. Pylori. Data on patient characteristics, clinical diagnosis and findings upon endoscopy were analyzed by simple descriptive statistics. Associations between categorical outcome variables were determined by Chi square test at 95% significance level.Results: H. pylori infection was high in patients with upper gastrointestinal symptoms 69.7% (1999) and 45.2% (2012), and was even higher in patients with gastritis and duodenal ulcer. H. pylori infection however, decreased among patients over the period, 69.7% in 1999 to 45.2% in 2012. Sex differences in H. pylori infection was identified (higher among males) and young adults (21-40 years). Commonest symptom in all patients was non-ulcer dyspepsia, 86.9% in 1999 and 84.2% in 2012, while gastritis and duodenal ulcer were the commonest endoscopic finding in the two periods.Conclusion: Appropriate management guidelines in West Africa considering the high background H. pylori infection and other co-infections requiring particular antibiotic combination therapy is required.Key words: Helicobacter pylori; endoscopy; prevalence; sex differences; Ghan

Examining intersectoral integration for malaria control programmes in an urban and a rural district in Ghana: a multinomial multilevel analysis

Background: Intersectoral integration is acknowledged to be essential for improving provision of health care and outcomes, yet it remains one of the main primary health care strategic challenges. Although this is well articulated in the literature, the factors that explain differentials in levels of intersectoral integration have not been systematically studied, particularly in low and middle-income countries. In this study, we examine the levels and determinants of intersectoral integration amongst institutions engaged in malaria control programmes in an urban (Kumasi Metropolitan) district and a rural (Ahafo Ano South) district in Ghana. Methods: Interviews were conducted with representatives of 32 institutions engaged in promoting malaria prevention and control. The averaging technique proposed by Brown et al. and a two-level multinomial multilevel ordinal logistic regression were used to examine the levels of integration and the factors that explain the differentials. Results: The results show high disparity in levels of integration amongst institutions in the two districts. Integration was higher in the rural district compared to the urban district. The multivariate analysis revealed that the district effect explained 25% of the variations in integration. The type of institution, level of focus on malaria and source of funding are important predictors of intersectoral integration. Conclusion: Although not causal, integrated malaria control programmes could be important for improving malaria-related health outcomes in less developed regions as evident from the rapid decline in malaria fatality rates observed in the Ahafo Ano South district. Harmonisation of programmes should be encouraged amongst institutions and the public and private sectors should be motivated to work in partnership

Identification of semiochemicals from cowpea, Vigna unguiculata, for low-input management of the Legume Pod Borer, Maruca vitrata

Cowpea, Vigna unguiculata L. Walp. (Fabaceae), is one of the most important food legumes grown on the African continent, as it provides an affordable source of dietary protein. Yields of cowpea are significantly reduced through damage by legume pod-borer, Maruca vitrata (Lepidoptera: Crambidae), caterpillars to flowers, tender leaves and pods. Semiochemical-based strategies are considered as environmentally benign and affordable for pest management, particularly on smallholder farms. In this study, we investigated the importance of cowpea flower volatiles as host location cues for egg-laying M. vitrata, and herbivore-induced plant volatiles (HIPVs) as M. vitrata repellents and natural enemy (Apanteles taragamae and Phanerotoma syleptae parasitoid) attractants. In oviposition choice assays, M. vitrata laid more eggs on flowering cowpea plants than non-flowering plants. Coupled gas chromatography-electrophysiology (GC-EAG) analysis using the antennae of female M. vitrata and an extract of flower volatiles collected by dynamic headspace collection revealed the presence of five EAG-active components that were identified by coupled GC-mass spectrometry (GC-MS) analysis as benzaldehyde, benzyl alcohol, acetophenone, a vinylbenzaldehyde isomer and (E)-cinnamaldehyde. A synthetic blend of the identified compounds, prepared using 3-vinylbenzaldehyde, induced M. vitrata to lay as many eggs on non-flowering cowpea as on flowering plants. The moths also preferred laying eggs on intact plants compared to M. vitrata-infested plants. As the emission of EAG-active floral compounds was determined to be lower in the headspace of infested cowpea flowers, the role of HIPVs emitted by M. vitrata-damaged leaves was also investigated. Of the compounds induced by larval damage, (E)-DMNT, indole, n-hexyl acetate, 1-octen-3-ol and linalool were shown by GC-EAG to possess electrophysiological activity. A synthetic blend of the EAG-active compounds, using racemic 1-octen-3-ol and linalool, significantly reduced egg numbers on flowering cowpea. Larval and egg parasitoids, i.e. A. taragamae and Ph. syleptae, respectively, of M. vitrata both preferred the Y-tube olfactometer arm treated with synthetic (E)-DMNT, whereas preference for racemic linalool and (E)-nerolidol was dose-dependent in A. taragamae. Our results provide the platform for the development of future semiochemical-based pest management strategies against M. vitrata on smallholder farms in West Africa

Renal DCE-MRI model selection using Bayesian probability theory

The goal of this work was to demonstrate the utility of Bayesian probability theory-based model selection for choosing the optimal mathematical model from among 4 competing models of renal dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data. DCE-MRI data were collected on 21 mice with high (n = 7), low (n = 7), or normal (n = 7) renal blood flow (RBF). Model parameters and posterior probabilities of 4 renal DCE-MRI models were estimated using Bayesian-based methods. Models investigated included (1) an empirical model that contained a monoexponential decay (washout) term and a constant offset, (2) an empirical model with a biexponential decay term (empirical/biexponential model), (3) the Patlak–Rutland model, and (4) the 2-compartment kidney model. Joint Bayesian model selection/parameter estimation demonstrated that the empirical/biexponential model was strongly favored for all 3 cohorts, the modeled DCE signals that characterized each of the 3 cohorts were distinctly different, and individual empirical/biexponential model parameter values clearly distinguished cohorts of low and high RBF from one another. The Bayesian methods can be readily extended to a variety of model analyses, making it a versatile and valuable tool for model selection and parameter estimation.</jats:p

Deciphering Plant-Insect-Microorganism Signals for Sustainable Crop Production

Agricultural crop productivity relies on the application of chemical pesticides to reduce pest and pathogen damage. However, chemical pesticides also pose a range of ecological, environmental and economic penalties. This includes the development of pesticide resistance by insect pests and pathogens, rendering pesticides less effective. Alternative sustainable crop protection tools should therefore be considered. Semiochemicals are signalling molecules produced by organisms, including plants, microbes, and animals, which cause behavioural or developmental changes in receiving organisms. Manipulating semiochemicals could provide a more sustainable approach to the management of insect pests and pathogens across crops. Here, we review the role of semiochemicals in the interaction between plants, insects and microbes, including examples of how they have been applied to agricultural systems. We highlight future research priorities to be considered for semiochemicals to be credible alternatives to the application of chemical pesticides

Repellency Potential, Chemical Constituents of Ocimum Plant Essential Oils, and Their Headspace Volatiles against Anopheles gambiae s. s., Malaria Vector

African malaria mosquitoes (Anopheles gambiae sensu stricto) transmit a malaria parasite (Plasmodium falciparum) to humans. The current control strategies for the vector have mainly focussed on synthetic products, which negatively impact the environment and human health. Given the potential use of environmentally friendly plant-derived volatiles as a control, this work aims to examine and compare the repellency potential of essential oils and headspace volatiles from Ocimum gratissimum, Ocimum tenuiflorum, and Ocimum basilicum and their chemical compositions. The repellency potential and chemical composition of the plants were achieved by using the protected arm-in-cage method and gas chromatography-mass spectrometry (GC-MS) analysis. Among the three Ocimum species, both the essential oils and the headspace volatiles from O. tenuiflorum achieved the longest repellency time lengths of 90–120 minutes. One hundred and one (101) chemical constituents were identified in the headspace volatiles of the three Ocimum spp. Nonetheless, (−)-camphor, (E)-γ-bisabolene, terpinolene, β-chamigrene, cubedol, (E)-farnesol, germacrene D-4-ol, viridiflorol, γ-eudesmol, tetracyclo [6.3.2.0 (2,5).0(1,8)] tridecan-9-ol, 4,4-dimethyl, α-eudesmol, isolongifolol, and endo-borneol were unique only to O. tenuiflorum headspace volatiles. Either essential oils or headspace volatiles from O. tenuiflorum could offer longer protection time length to humans against An. gambiae. Though field studies are needed to assess the complementarity between the chemical constituents in the headspace volatiles of O. tenuiflorum, our observations provide a foundation for developing effective repellents against An. gambiae