The entomopathogenic fungus Beauveria bassiana reduces instantaneous blood feeding in wild multi-insecticide-resistant Culex quinquefasciatus mosquitoes in Benin, West Africa.

BACKGROUND: Mosquito-borne diseases are still a major health risk in many developing countries, and the emergence of multi-insecticide-resistant mosquitoes is threatening the future of vector control. Therefore, new tools that can manage resistant mosquitoes are required. Laboratory studies show that entomopathogenic fungi can kill insecticide-resistant malaria vectors but this needs to be verified in the field. METHODS: The present study investigated whether these fungi will be effective at infecting, killing and/or modifying the behaviour of wild multi-insecticide-resistant West African mosquitoes. The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were separately applied to white polyester window netting and used in combination with either a permethrin-treated or untreated bednet in an experimental hut trial. Untreated nets were used because we wanted to test the effect of fungus alone and in combination with an insecticide to examine any potential additive or synergistic effects. RESULTS: In total, 1125 female mosquitoes were collected during the hut trial, mainly Culex quinquefasciatus Say. Unfortunately, not enough wild Anopheles gambiae Giles were collected to allow the effect the fungi may have on this malaria vector to be analysed. None of the treatment combinations caused significantly increased mortality of Cx. quinquefasciatus when compared to the control hut. The only significant behaviour modification found was a reduction in blood feeding by Cx. quinquefasciatus, caused by the permethrin and B. bassiana treatments, although no additive effect was seen in the B. bassiana and permethrin combination treatment. Beauveria bassiana did not repel blood foraging mosquitoes either in the laboratory or field. CONCLUSIONS: This is the first time that an entomopathogenic fungus has been shown to reduce blood feeding of wild mosquitoes. This behaviour modification indicates that B. bassiana could potentially be a new mosquito control tool effective at reducing disease transmission, although further field work in areas with filariasis transmission should be carried out to verify this. In addition, work targeting malaria vector mosquitoes should be carried out to see if these mosquitoes manifest the same behaviour modification after infection with B. bassiana conidia

LRP1 Has a Predominant Role in Production over Clearance of Aβ in a Mouse Model of Alzheimer's Disease.

The low-density lipoprotein receptor-related protein-1 (LRP1) has a dual role in the metabolism of the amyloid precursor protein (APP). In cellular models, LRP1 enhances amyloid-β (Aβ) generation via APP internalization and thus its amyloidogenic processing. However, conditional knock-out studies in mice define LRP1 as an important mediator for the clearance of extracellular Aβ from brain via cellular degradation or transcytosis across the blood-brain barrier (BBB). In order to analyze the net effect of LRP1 on production and clearance of Aβ in vivo, we crossed mice with impaired LRP1 function with a mouse model of Alzheimer's disease (AD). Analysis of Aβ metabolism showed that, despite reduced Aβ clearance due to LRP1 inactivation in vivo, less Aβ was found in cerebrospinal fluid (CSF) and brain interstitial fluid (ISF). Further analysis of APP metabolism revealed that impairment of LRP1 in vivo shifted APP processing from the Aβ-generating amyloidogenic cleavage by beta-secretase to the non-amyloidogenic processing by alpha-secretase as shown by a decrease in extracellular Aβ and an increase of soluble APP-α (sAPP-α). This shift in APP processing resulted in overall lower Aβ levels and a reduction in plaque burden. Here, we present for the first time clear in vivo evidence that global impairment of LRP1's endocytosis function favors non-amyloidogenic processing of APP due to its reduced internalization and subsequently, reduced amyloidogenic processing. By inactivation of LRP1, the inhibitory effect on Aβ generation overrules the simultaneous impaired Aβ clearance, resulting in less extracellular Aβ and reduced plaque deposition in a mouse model of AD

Changes in the availability and affordability of subsidised artemisinin combination therapy in the private drug retail sector in rural Ghana: before and after the introduction of the AMFm subsidy.

BACKGROUND: Most people with febrile illness are treated in the private drug retail sector. Ghana was among nine countries piloting the Global Fund Affordable Medicines Facility - malaria (AMFm). AMFm aimed to: increase artemisinin combination therapy (ACT) affordability; increase ACT availability; increase ACT use; and 'crowd out' artemisinin monotherapies. METHODS: Three censuses were carried out 2 months before (2010), 2 months after and 2.5 years after (2013) the first co-paid ACTs to assess changes in antimalarial (AM) availability and price in private retail shops in a Ghanaian rural district to assess the sustainability of the initial gains. Supply, stock-out and cost were explored. RESULTS: Of 62 shops in the district, 56 participated with 398, 388 and 442 brands of AMs in the shops during the 3 censuses. The proportion of ACTs increased over the period while monotherapies reduced. Herbal-based AM preparations comprised 40-45% of AMs in stock with minimal variation over the period. ACTs were the most sold AM type for all ages but overall buying and selling prices of Quality Assured-ACTs increased by 40-100%. CONCLUSIONS: Initial gains in ACT availability were sustained, but not improved on 2.5 years after AMFm. Widespread availability of unproven herbal medicines is a concern; AMFm had little impact on this

Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

<p>Abstract</p> <p>Background</p> <p>Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (<it>Anopheles </it>species, age and larval density), fungus (species and concentration) and environmental effects (exposure duration and food availability) influence larval mortality caused by fungus, was studied.</p> <p>Methods</p> <p>Laboratory bioassays were performed on the larval stages of <it>Anopheles gambiae </it>and <it>Anopheles stephensi </it>with spores of two fungus species, <it>Metarhizium anisopliae </it>and <it>Beauveria bassiana</it>. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses.</p> <p>Results</p> <p><it>Beauveria bassiana </it>and <it>Metarhizium anisopliae </it>caused high mortality of <it>An. gambiae </it>and <it>An. stephensi </it>larvae. However, <it>Beauveria bassiana </it>was less effective (Hazard ratio (HR) <1) compared to <it>Metarhizium anisopliae. Anopheles stephensi </it>and <it>An. gambiae </it>were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR < 1). The effect of increase in fungus concentration on larval mortality was influenced by spore clumping. One day exposure to fungal spores was found to be equally effective as seven days exposure. In different exposure time treatments 0 - 4.9% of the total larvae, exposed to fungus, showed infection at either the pupal or adult stage. Mortality rate increased with increasing larval density and amount of available food.</p> <p>Conclusions</p> <p>This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.</p

Factors influencing choice of care-seeking for acute fever comparing private chemical shops with health centres and hospitals in Ghana: a study using case-control methodology.

BACKGROUND: Several public health interventions to improve management of patients with fever are largely focused on the public sector yet a high proportion of patients seek care outside the formal healthcare sector. Few studies have provided information on the determinants of utilization of the private sector as against formal public sector. Understanding the differences between those who attend public and private health institutions, and their pathway to care, has significant practical implications. The chemical shop is an important source of care for acute fever in Ghana. METHODS: Case-control methodology was used to identify factors associated with seeking care for fever in the Dangme West District, Ghana. People presenting to health centres, or hospital outpatients, with a history or current fever were compared to counterparts from the same community with fever visiting a chemical shop. RESULTS: Of 600 patients, 150 each, were recruited from the district hospital and two health centres, respectively, and 300 controls from 51 chemical shops. Overall, 103 (17.2 %) patients tested slide positive for malaria. Specifically, 13.7 % (41/300) of chemical shop patients, 30.7 % (46/150) health centre and 10.7 % (16/150) hospital patients were slide positive. While it was the first option for care for 92.7 % (278/300) chemical shop patients, 42.7 % (64/150) of health centre patients first sought care from a chemical shop. More health centre patients (61.3 %; 92/150) presented with fever after more than 3 days than chemical shop patients (27.7 %; 83/300) [AOR = 0.19; p < 0.001 CI 0.11-0.30]. Although the hospital was the first option for 83.3 % (125/150) of hospital patients, most (63.3 %; 95/150) patients arrived there over 3 days after their symptoms begun. Proximity was significantly associated with utilization of each source of care. Education, but not other socioeconomic or demographic factors were significantly associated with chemical shop use. CONCLUSIONS: The private drug retail sector is the first option for the majority of patients, including poorer patients, with fever in this setting. Most patients with fever arrive at chemical shops with less delay and fewer signs of severity than at public health facilities. Improving chemical shop skills is a good opportunity to diagnose, treat or refer people with fever early

Egg hatching, larval movement and larval survival of the malaria vector Anopheles gambiae in desiccating habitats

BACKGROUND: Although the effects of rainfall on the population dynamics of the malaria vector Anopheles gambiae have been studied in great detail, the effects of dry periods on its survival remain less clear. METHODS: The effects of drying conditions were simulated by creating desiccated habitats, which consisted of trays filled with damp soil. Experiments were performed in these trays to (i) test the ability of An. gambiae sensu stricto eggs to hatch on damp soil and for larvae to reach an artificial breeding site at different distances of the site of hatching and (ii) to record survival of the four larval stages of An. gambiae s.s. when placed on damp soil. RESULTS: Eggs of An. gambiae s.s. hatched on damp soil and emerging larvae were capable of covering a distance of up to 10 cm to reach surface water enabling further development. However, proportions of larvae reaching the site decreased rapidly with increasing distance. First, second and third-instar larvae survived on damp soil for an estimated period of 64, 65 and 69 hrs, respectively. Fourth-instar larvae survived significantly longer and we estimated that the maximum survival time was 113 hrs. CONCLUSION: Short-term survival of aquatic stages of An. gambiae on wet soil may be important and adaptive when considering the transient nature of breeding sites of this species in sub-Saharan Africa. In addition, the results suggest that, for larval vector control methods to be effective, habitats should remain drained for at least 5 days to kill all larvae (e.g. in rice fields) and habitats that recently dried up should be treated as well, if larvicidal agents are applied

A nonsense mutation in B3GALNT2 is concordant with hydrocephalus in Friesian horses

Background: Hydrocephalus in Friesian horses is a developmental disorder that often results in stillbirth of affected foals and dystocia in dams. The occurrence is probably related to a founder effect and inbreeding in the population. The aim of our study was to find genomic associations, to investigate the mode of inheritance, to allow a DNA test for hydrocephalus in Friesian horses to be developed. In case of a monogenic inheritance we aimed to identify the causal mutation. Results: A genome-wide association study of hydrocephalus in 13 cases and 69 controls using 29,720 SNPs indicated the involvement of a region on ECA1 (P T corresponding to XP_001491595 p.Gln475* was identical to a B3GALNT2 mutation identified in a human case of muscular dystrophy-dystroglycanopathy with hydrocephalus. All 16 available cases and none of the controls were homozygous for the mutation, and all 17 obligate carriers (= dams of cases) were heterozygous. A random sample of the Friesian horse population (n = 865) was tested for the mutation in a commercial laboratory. One-hundred and forty-seven horses were carrier and 718 horses were homozygous for the normal allele; the estimated allele frequency in the Friesian horse population is 0.085. Conclusions: Hydrocephalus in Friesian horses has an autosomal recessive mode of inheritance. A nonsense mutation XM_001491545 c.1423C>T corresponding to XP_001491595 p.Gln475* in B3GALNT2 (1: 75,859,296-75,909,376) is concordant with hydrocephalus in Friesian horses. Application of a DNA test in the breeding programme will reduce the losses caused by hydrocephalus in the Friesian horse population

Differences in the mannose oligomer specificities of the closely related lectins from Galanthus nivalis and Zea mays strongly determine their eventual anti-HIV activity

<p>Abstract</p> <p>Background</p> <p>In a recent report, the carbohydrate-binding specificities of the plant lectins <it>Galanthus nivalis </it>(GNA) and the closely related lectin from <it>Zea mays </it>(GNA_maize) were determined by glycan array analysis and indicated that GNA_maizerecognizes complex-type N-glycans whereas GNA has specificity towards high-mannose-type glycans. Both lectins are tetrameric proteins sharing 64% sequence similarity.</p> <p>Results</p> <p>GNA_maizeappeared to be ~20- to 100-fold less inhibitory than GNA against HIV infection, syncytia formation between persistently HIV-1-infected HuT-78 cells and uninfected CD4⁺T-lymphocyte SupT1 cells, HIV-1 capture by DC-SIGN and subsequent transmission of DC-SIGN-captured virions to uninfected CD4⁺T-lymphocyte cells. In contrast to GNA, which preferentially selects for virus strains with deleted high-mannose-type glycans on gp120, prolonged exposure of HIV-1 to dose-escalating concentrations of GNA_maizeselected for mutant virus strains in which one complex-type glycan of gp120 was deleted. Surface Plasmon Resonance (SPR) analysis revealed that GNA and GNA_maizeinteract with HIV III_Bgp120 with affinity constants (K_D) of 0.33 nM and 34 nM, respectively. Whereas immobilized GNA specifically binds mannose oligomers, GNA_maizeselectively binds complex-type GlcNAcβ1,2Man oligomers. Also, epitope mapping experiments revealed that GNA and the mannose-specific mAb 2G12 can independently bind from GNA_maizeto gp120, whereas GNA_maizecannot efficiently bind to gp120 that contained prebound PHA-E (GlcNAcβ1,2man specific) or SNA (NeuAcα2,6X specific).</p> <p>Conclusion</p> <p>The markedly reduced anti-HIV activity of GNA_maizecompared to GNA can be explained by the profound shift in glycan recognition and the disappearance of carbohydrate-binding sites in GNA_maizethat have high affinity for mannose oligomers. These findings underscore the need for mannose oligomer recognition of therapeutics to be endowed with anti-HIV activity and that mannose, but not complex-type glycan binding of chemotherapeutics to gp120, may result in a pronounced neutralizing activity against the virus.</p

First report of the infection of insecticide-resistant malaria vector mosquitoes with an entomopathogenic fungus under field conditions

BACKGROUND: Insecticide-resistant mosquitoes are compromising the ability of current mosquito control tools to control malaria vectors. A proposed new approach for mosquito control is to use entomopathogenic fungi. These fungi have been shown to be lethal to both insecticide-susceptible and insecticide-resistant mosquitoes under laboratory conditions. The goal of this study was to see whether entomopathogenic fungi could be used to infect insecticide-resistant malaria vectors under field conditions, and to see whether the virulence and viability of the fungal conidia decreased after exposure to ambient African field conditions. METHODS: This study used the fungus Beauveria bassiana to infect the insecticide-resistant malaria vector Anopheles gambiae s.s (Diptera: Culicidae) VKPER laboratory colony strain. Fungal conidia were applied to polyester netting and kept under West African field conditions for varying periods of time. The virulence of the fungal-treated netting was tested 1, 3 and 5 days after net application by exposing An. gambiae s.s. VKPER mosquitoes in WHO cone bioassays carried out under field conditions. In addition, the viability of B. bassiana conidia was measured after up to 20 days exposure to field conditions. RESULTS: The results show that B. bassiana infection caused significantly increased mortality with the daily risk of dying being increased by 2.5 × for the fungus-exposed mosquitoes compared to the control mosquitoes. However, the virulence of the B. bassiana conidia decreased with increasing time spent exposed to the field conditions, the older the treatment on the net, the lower the fungus-induced mortality rate. This is likely to be due to the climate because laboratory trials found no such decline within the same trial time period. Conidial viability also decreased with increasing exposure to the net and natural abiotic environmental conditions. After 20 days field exposure the conidial viability was 30%, but the viability of control conidia not exposed to the net or field conditions was 79%. CONCLUSIONS: This work shows promise for the use of B. bassiana fungal conidia against insecticide-resistant mosquitoes in the field, but further work is required to examine the role of environmental conditions on fungal virulence and viability with a view to eventually making the fungal conidia delivery system more able to withstand the ambient African climate

Clinimetric evaluation of methods to measure muscle functioning in patients with non-specific neck pain: a systematic review

Contains fulltext : 69123.pdf (publisher's version ) (Open Access)BACKGROUND: Neck pain is a significant health problem in modern society. There is evidence to suggest that neck muscle strength is reduced in patients with neck pain. This article provides a critical analysis of the research literature on the clinimetric properties of tests to measure neck muscle strength or endurance in patients with non-specific neck pain, which can be used in daily practice. METHODS: A computerised literature search was performed in the Medline, CINAHL and Embase databases from 1980 to January 2007. Two reviewers independently assessed the clinimetric properties of identified measurement methods, using a checklist of generally accepted criteria for reproducibility (inter- and intra-observer reliability and agreement), construct validity, responsiveness and feasibility. RESULTS: The search identified a total of 16 studies. The instruments or tests included were: muscle endurance tests for short neck flexors, craniocervical flexion test with an inflatable pressure biofeedback unit, manual muscle testing of neck musculature, dynamometry and functional lifting tests (the cervical progressive iso-inertial lifting evaluation (PILE) test and the timed weighted overhead test). All the articles included report information on the reproducibility of the tests. Acceptable intra- and inter-observer reliability was demonstrated for t enduranctest for short neck flexors and the cervical PILE test. Construct validity and responsiveness have hardly been documented for tests on muscle functioning. CONCLUSION: The endurance test of the short neck flexors and the cervical PILE test can be regarded as appropriate instruments for measuring different aspects of neck muscle function in patients with non-specific neck pain. Common methodological flaws in the studies were their small sample size and an inappropriate description of the study design