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Abstract Background Soil-transmitted helminthiasis (STH) are a parasitic infection that predominantly affects impoverished regions. Model-based geostatistics (MBG) has been established as a set of modern statistical methods that enable mapping of disease risk in a geographical area of interest. We investigate how the use of remotely sensed covariates can help to improve the predictive inferences on STH prevalence using MBG methods. In particular, we focus on how the covariates impact on the classification of areas into distinct class of STH prevalence. Methods This study uses secondary data obtained from a sample of 1551 schools in Kenya, gathered through a combination of longitudinal and cross-sectional surveys. We compare the performance of two geostatistical models: one that does not make use of any spatially referenced covariate; and a second model that uses remotely sensed covariates to assist STH prevalence prediction. We also carry out a simulation study in which we compare the performance of the two models in the classifications of areal units with varying sample sizes and prevalence levels. Results The model with covariates generated lower levels of uncertainty and was able to classify 88 more districts into prevalence classes than the model without covariates, which instead left those as “unclassified”. The simulation study showed that the model with covariates also yielded a higher proportion of correct classification of at least 40% for all sub-counties. Conclusion Covariates can substantially reduce the uncertainty of the predictive inference generated from geostatistical models. Using covariates can thus contribute to the design of more effective STH control strategies by reducing sample sizes without compromising the predictive performance of geostatistical models.

Abstract Resource availability can alter infection outcomes through its impact on host immunity and on parasite reproduction. On one hand, enhanced nutrition could favor immunity, limiting the parasite, and on the other hand, it could favor establishment and reproduction of the parasite. Our study aimed to determine the effect of diet on (1) host susceptibility to infection and (2) parasite production in a snail‐trematode system. We fed Biomphalaria sudanica, a snail vector of Schistosoma mansoni, either a strict lettuce (low nutrient) or pellet (high nutrient) diet for two generations before exposing them to S. mansoni. We used two parasite strains, one that is incompatible with the snails and one that is compatible with the snails. We found that when exposed to incompatible parasites, diet did not affect snail susceptibility significantly as few snails were infected overall. However, when challenged with the compatible parasites, snails fed the high‐nutrient diet were more susceptible to infection than their low‐nutrient‐fed counterparts. The high‐nutrient‐fed snails also produced more cercariae than low‐nutrient‐fed snails, but this advantage was lost after the initial assessment at 8 weeks. Snails that obtained infections were either kept on their initial diet or switched to the other diet. This experiment showed that snails switched from a low‐to‐high‐nutrient diet produced more cercariae than those remaining on the low‐nutrient diet and similar numbers to those remaining on the high‐nutrient diet. Unexpectedly, the reciprocal diet switch (high to low nutrient) initially resulted in more cercariae relative to controls, but the pattern reversed after initial assessment. This study showed that available resources can impact the susceptibility of the vector host and the reproductive capacity of the parasites, with higher nutrients favoring parasite establishment and reproduction, highlighting the plasticity of susceptibility phenotypes, which also have a strong genetic basis. These data can aid predictions of how future environmental changes and resource availability may impact parasite transmission.

Crinoids belong to the Echinodermata, marine invertebrates with a highly derived adult pentaradial body plan. As the sister group to all other extant echinoderms, crinoids occupy a key phylogenetic position to explore the evolutionary history of the whole phylum. However, their development remains understudied compared with that of other echinoderms. Therefore, the aim here was to establish the Mediterranean feather star (Antedon mediterranea) as an experimental system for developmental biology. We first set up a method for culturing embryos in vitro and defined a standardized staging system for this species. We then optimized protocols to characterize the morphological and molecular development of the main structures of the feather star body plan. Focusing on the nervous system, we showed that the larval apical organ includes serotonergic, GABAergic and glutamatergic neurons, which develop within a conserved anterior molecular signature. We described the composition of the early post-metamorphic nervous system and revealed that it has an anterior signature. These results further our knowledge on crinoid development and provide new techniques to investigate feather star embryogenesis. This will pave the way for the inclusion of crinoids in comparative studies addressing the origin of the echinoderm body plan and the evolutionary diversification of deuterostomes.

Abstract Background Control and elimination of schistosomiasis is an arduous task, with current strategies proving inadequate to break transmission. Exploration of genetic approaches to interrupt Schistosoma mansoni transmission, the causative agent for human intestinal schistosomiasis in sub-Saharan Africa and South America, has led to genomic research of the snail vector hosts of the genus Biomphalaria. Few complete genomic resources exist, with African Biomphalaria species being particularly underrepresented despite this being where the majority of S. mansoni infections occur. Here we generate and annotate the first genome assembly of Biomphalaria sudanica sensu lato, a species responsible for S. mansoni transmission in lake and marsh habitats of the African Rift Valley. Supported by whole-genome diversity data among five inbred lines, we describe orthologs of immune-relevant gene regions in the South American vector B. glabrata and present a bioinformatic pipeline to identify candidate novel pathogen recognition receptors (PRRs). Results De novo genome and transcriptome assembly of inbred B. sudanica originating from the shoreline of Lake Victoria (Kisumu, Kenya) resulted in a haploid genome size of ~ 944.2 Mb (6,728 fragments, N50 = 1.067 Mb), comprising 23,598 genes (BUSCO = 93.6% complete). The B. sudanica genome contains orthologues to all described immune genes/regions tied to protection against S. mansoni in B. glabrata, including the polymorphic transmembrane clusters (PTC1 and PTC2), RADres, and other loci. The B. sudanica PTC2 candidate immune genomic region contained many PRR-like genes across a much wider genomic region than has been shown in B. glabrata, as well as a large inversion between species. High levels of intra-species nucleotide diversity were seen in PTC2, as well as in regions linked to PTC1 and RADres orthologues. Immune related and putative PRR gene families were significantly over-represented in the sub-set of B. sudanica genes determined as hyperdiverse, including high extracellular diversity in transmembrane genes, which could be under pathogen-mediated balancing selection. However, no overall expansion in immunity related genes was seen in African compared to South American lineages. Conclusions The B. sudanica genome and analyses presented here will facilitate future research in vector immune defense mechanisms against pathogens. This genomic/transcriptomic resource provides necessary data for the future development of molecular snail vector control/surveillance tools, facilitating schistosome transmission interruption mechanisms in Africa.

BackgroundThe standard diagnosis of Ascaris lumbricoides and other soil-transmitted helminth (STH) infections relies on the detection of worm eggs by copromicroscopy. However, this method is dependent on worm patency and shows only limited accuracy in low-intensity infection settings. We aimed to decipher the diagnostic accuracy of different antibodies using various Ascaris antigens in reference to copromicroscopy and quantitative PCR (qPCR), four months after national STH preventative chemotherapy among school children in western Kenya.MethodologySTH infection status of 390 school children was evaluated via copromicroscopy (Kato-Katz and mini-FLOTAC) and qPCR. In parallel, Ascaris-specific antibody profiles against larval and adult worm lysates, and adult worm excretory-secretory (ES) products were determined by enzyme-linked immunosorbent assay. Antibody cross-reactivity was evaluated using the closely related zoonotic roundworm species Toxocara cati and Toxocara canis. The diagnostic accuracy of each antibody was evaluated using receiver operating curve analysis and the correspondent area under the curve (AUC).Principal findingsAscaris was the predominant helminth infection with an overall prevalence of 14.9% (58/390). The sensitivity of mini-FLOTAC and Kato-Katz for Ascaris diagnosis reached only 53.5% and 63.8%, respectively compared to qPCR. Although being more sensitive, qPCR values correlated with microscopic egg counts (R = -0.71, PConclusionIgG1 antibody responses against adult Ascaris-ES products hold a promising potential for complementing the standard fecal and molecular techniques employed for monitoring Ascaris infections. This is of particular importance in the context of deworming programs as the antibody diagnostic accuracy was independent of egg counts.

Starfish are keystone species as predators in benthic ecosystems, but when population outbreaks occur, this can have devastating consequences ecologically. Furthermore, starfish outbreaks and invasions can have adverse impact economically by impacting shellfish aquaculture. For example, an infestation of starfish in Qingdao led to a 50% reduction in sea cucumber production and an 80% reduction in scallop production, resulting in an economic loss of approximately RMB 100 million to oyster and other shellfish industries. Addressing the imperative need to proactively mitigate starfish invasions requires comprehensive research on their behavior and the underlying mechanisms of outbreaks. This review scrutinizes the historical patterns of outbreaks among diverse starfish species across various regions, delineates the factors contributing to the proliferation of Asterias amurensis in Chinese waters, articulates preventive and remedial strategies, and outlines the potential for the sustainable utilization of starfish.

Abstract The nervous system of the Asteroidea (starfish or seastar) consists of radial nerve cords (RNCs) that interconnect with a ring nerve. Despite its relative simplicity, it facilitates the movement of multiple arms and numerous tube feet, as well as regeneration of damaged limbs. Here, we investigated the RNC ultrastructure and its molecular components within the of Pacific crown-of-thorns starfish (COTS; Acanthaster sp.), a well-known coral predator that in high-density outbreaks has major ecological impacts on coral reefs. We describe the presence of an array of unique small bulbous bulbs (40–100 μm diameter) that project from the ectoneural region of the adult RNC. Each comprise large secretory-like cells and prominent cilia. In contrast, juvenile COTS and its congener Acanthaster brevispinus lack these features, both of which are non-corallivorous. Proteomic analysis of the RNC (and isolated neural bulbs) provides the first comprehensive echinoderm protein database for neural tissue, including numerous secreted proteins associated with signalling, transport and defence. The neural bulbs contained several neuropeptides (e.g., bombyxin-type, starfish myorelaxant peptide, secretogranin 7B2-like, Ap15a-like, and ApNp35) and Deleted in Malignant Brain Tumor 1-like proteins. In summary, this study provides a new insight into the novel traits of COTS, a major pest on coral reefs, and a proteomics resource that can be used to develop (bio)control strategies and understand molecular mechanisms of regeneration.

Abstract Background Kisspeptins are neuropeptides that regulate reproductive maturation in mammals via G-protein-coupled receptor-mediated stimulation of gonadotropin-releasing hormone secretion from the hypothalamus. Phylogenetic analysis of kisspeptin-type receptors indicates that this neuropeptide signaling system originated in a common ancestor of the Bilateria, but little is known about kisspeptin signaling in invertebrates. Results Contrasting with the occurrence of a single kisspeptin receptor in mammalian species, here, we report the discovery of an expanded family of eleven kisspeptin-type receptors in a deuterostome invertebrate — the starfish Asterias rubens (phylum Echinodermata). Furthermore, neuropeptides derived from four precursor proteins were identified as ligands for six of these receptors. One or more kisspeptin-like neuropeptides derived from two precursor proteins (ArKPP1, ArKPP2) act as ligands for four A. rubens kisspeptin-type receptors (ArKPR1,3,8,9). Furthermore, a family of neuropeptides that act as muscle relaxants in echinoderms (SALMFamides) are ligands for two A. rubens kisspeptin-type receptors (ArKPR6,7). The SALMFamide neuropeptide S1 (or ArS1.4) and a ‘cocktail’ of the seven neuropeptides derived from the S1 precursor protein (ArS1.1-ArS1.7) act as ligands for ArKPR7. The SALMFamide neuropeptide S2 (or ArS2.3) and a ‘cocktail’ of the eight neuropeptides derived from the S2 precursor protein (ArS2.1-ArS2.8) act as ligands for ArKPR6. Conclusions Our findings reveal a remarkable diversity of neuropeptides that act as ligands for kisspeptin-type receptors in starfish and provide important new insights into the evolution of kisspeptin signaling. Furthermore, the discovery of the hitherto unknown relationship of kisspeptins with SALMFamides, neuropeptides that were discovered in starfish prior to the identification of kisspeptins in mammals, presents a radical change in perspective for research on kisspeptin signaling.

Teaching science in distance learning has severely challenged the educators in maintaining a quality learning experience during the pandemic. This also opened to new experiences for science teachers to facilitate learning in a new normal setting, especially in rural schools. This qualitative phenomenological study aimed to describe the lived experiences of rural science teachers during the new normal learning. Ethical standards on trustworthiness and rigor were followed. Five (5) participants were purposively chosen through criterion sampling with the following criteria: 1) should be a junior/senior high school rural teacher 30-55 years old. 2) Should be teaching science in the school year 2020-2021. 3) Should be willing to express and share their experiences. Data were collected from unstructured interviews. Narratives were transcribed word for word and reflectively analyzed using Braun and Clarke’s (2006) thematic analysis. Analyzed data revealed four (4) dominant themes: (1): 4A’s of New Normal: Accept, Arrange, Adjust, and Adapt. (2) Dare to Teach: Agents of Learning, Frontliners of Teaching. (3) Facing New Variants of Students. (4) A Dose of Hope: Educators’ Response to Learning Emergency. The findings of the study contributed to a deeper understanding of the experiences of rural science teachers as they facilitate learning amidst the pandemic. Implications were derived based on the findings. It is challenging for science teachers to grasp students’ attention in learning through a modality away from the instructors. Meaningful learning in science has been facilitated using the teachers’ interventions through localized experiments, modified activities, and demystified lessons.

Interactions between Schistosoma mansoni and its snail host are understood primarily through experimental work with one South American vector species, Biomphalaria glabrata. However, 90% of schistosomiasis transmission occurs in Africa, where a diversity of Biomphalaria species may serve as vectors. With the long-term goal of determining the genetic and ecological determinants of infection in African snail hosts, we developed genetic models of Biomphalaria sudanica, a principal vector in the African Great Lakes. We determined laboratory infection dynamics of two S. mansoni lines in four B. sudanica lines. We measured the effects of the following variables on infection success and the number of cercariae produced (infection intensity): (i) the combination of parasite and snail line; (ii) the dose of parasites; and (iii) the size of snail at time of exposure. We found one snail line to be almost completely incompatible with both parasite lines, while other snail lines showed a polymorphism in compatibility: compatible with one parasite line while incompatible with another. Interestingly, these patterns were opposite in some of the snail lines. The parasite-snail combination had no significant effect on the number of cercariae produced in a successful infection. Miracidia dose had a strong effect on infection status, in that higher doses led to a greater proportion of infected snails, but had no effect on infection intensity. In one of the snail-schistosome combinations, snail size at the time of exposure affected both infection status and cercarial production in that the smallest size class of snails (1.5–2.9 mm) had the highest infection rates, and produced the greatest number of cercariae, suggesting that immunity increases with age and development. The strongest predictor of the infection intensity was the size of snail at the time of shedding: 1 ​mm of snail growth equated to a 19% increase in cercarial production. These results strongly suggest that infection status is determined in part by the interaction between snail and schistosome genetic lines, consistent with a gene-for-gene or matching allele model. This foundational work provides rationale for determining the genetic interactions between African snails and schistosomes, which may be applied to control strategies.

BackgroundAccurate mapping of schistosomiasis (SCH) and soil transmitted helminths (STH) is a prerequisite for effective implementation of the control and elimination interventions. A precision mapping protocol was developed and implemented in the coastal region of Kenya by applying the current World Health Organization (WHO) mapping guide at a much lower administrative level (ward).MethodsA two-stage cluster survey design was undertaken, with 5 villages in each ward selected. From within each village 50 households were randomly selected, and a single child between the ages of 8 and 14 sampled following appropriate assent. The prevalence and intensity of infection of Schistosoma mansoni and STH were determined using the Kato-Katz method (single stool, duplicate slides) and urine filtration for S. haematobium.ResultsOf the 27,850 school age children sampled, 6.9% were infected with at least one Schistosoma species, with S. haematobium being the most common 6.1% (95% CI: 3.1-11.9), and Tana River County having highest prevalence 19.6% (95% CI: 11.6-31.3). Prevalence of any STH infection was 5.8% (95% CI: 3.7-8.9), with Lamu County having the highest prevalence at 11.9% (95% CI: 10.0-14.1). The most prevalent STH species in the region was Trichuris trichiura at 3.1% (95% CI: 2.0-4.8). According to the WHO threshold for MDA implementation, 31 wards (in 15 sub-Counties) had a prevalence of ≥10% for SCH and thus qualify for annual MDA of all age groups from 2 years old. On the other hand, using the stricter Kenya BTS MDA threshold of ≥2%, 72 wards (in 17 sub-Counties) qualified for MDA and were targeted for treatment in 2021.ConclusionsThe precision mapping at the ward level demonstrated the variations of schistosomiasis prevalence and endemicity by ward even within the same sub-counties. The data collected will be utilized by the Kenyan Ministry of Health to improve targeting.

Neuropeptides are one of the largest and most diverse families of signaling molecules in animals and, accordingly, they regulate many physiological processes and behaviors. Genome and transcriptome sequencing has enabled the identification of genes encoding neuropeptide precursor proteins in species from a growing variety of taxa, including bilaterian and non-bilaterian animals. Of particular interest are deuterostome invertebrates such as the phylum Echinodermata, which occupies a phylogenetic position that has facilitated reconstruction of the evolution of neuropeptide signaling systems in Bilateria. However, our knowledge of neuropeptide signaling in echinoderms is largely based on bioinformatic and experimental analysis of eleutherozoans—Asterozoa (starfish and brittle stars) and Echinozoa (sea urchins and sea cucumbers). Little is known about neuropeptide signaling in crinoids (feather stars and sea lilies), which are a sister clade to the Eleutherozoa. Therefore, we have analyzed transcriptome/genome sequence data from three feather star species, Anneissia japonica, Antedon mediterranea, and Florometra serratissima, to produce the first comprehensive identification of neuropeptide precursors in crinoids. These include representatives of bilaterian neuropeptide precursor families and several predicted crinoid neuropeptide precursors. Using A. mediterranea as an experimental model, we have investigated the expression of selected neuropeptides in larvae (doliolaria), post-metamorphic pentacrinoids and adults, providing new insights into the cellular architecture of crinoid nervous systems. Thus, using mRNA in situ hybridization F-type SALMFamide precursor transcripts were revealed in a previously undescribed population of peptidergic cells located dorso-laterally in doliolaria. Furthermore, using immunohistochemistry a calcitonin-type neuropeptide was revealed in the aboral nerve center, circumoral nerve ring and oral tube feet in pentacrinoids and in the ectoneural and entoneural compartments of the nervous system in adults. Moreover, functional analysis of a vasopressin/oxytocin-type neuropeptide (crinotocin), which is expressed in the brachial nerve of the arms in A. mediterranea, revealed that this peptide causes a dose-dependent change in the mechanical behavior of arm preparations in vitro—the first reported biological action of a neuropeptide in a crinoid. In conclusion, our findings provide new perspectives on neuropeptide signaling in echinoderms and the foundations for further exploration of neuropeptide expression/function in crinoids as a sister clade to eleutherozoan echinoderms.

BackgroundFemale genital schistosomiasis (FGS) constitutes four different lesions known to be caused by Schistosoma haematobium ova deposited in the genital tract. Schistosoma mansoni ova may also be found in the genital tract. However, it is not known if S. mansoni causes lower genital tract lesions characteristic of FGS.MethodologyThis study was conducted in 8 villages along the shores of Lake Victoria, western Kenya. Stool and urine samples, collected from women of reproductive age on three consecutive days, were analysed for S. mansoni and S. haematobium infection. S. mansoni positive and S. haematobium negative willing participants, aged 18-50 years were invited to answer a questionnaire (demographics, symptoms), undergo a gynaecological examination and cytology specimen collection by an FGS expert.Principal findingsGynaecologic investigations were conducted in 147 S. mansoni-positive women who had a mean infection intensity of 253.3 epg (95% CI: 194.8-311.9 epg). Nearly 90% of them used Lake Victoria as their main water source. None were found to have cervicovaginal grainy sandy patches or rubbery papules. Homogenous yellow patches were found in 12/147 (8.2%) women. Women with homogenous yellow patches were significantly older (47 years) than the rest (34 years, p = 0.001). No association was found between intensity of S. mansoni infection and homogenous yellow patches (p = 0.70) or abnormal blood vessels (p = 0.14). S. mansoni infection intensity was not associated with genital itch, bloody or malodorous vaginal discharge.ConclusionS. mansoni infection was neither associated with lower genital tract lesions nor symptoms typically found in women with FGS.

IntroductionCurrent diagnostic tools for schistosomiasis are limited, and new tests are necessary to enhance disease diagnosis and surveillance. Identification of novel disease-specific biomarkers may facilitate the development of such tests. We evaluated a panel of biomarkers used in sepsis and parasitic diseases for their potential suitability in the diagnosis of schistosomiasis.ObjectiveThe study evaluated the levels of systemic plasma biomarkers in relation to Schistosoma mansoni infection and parasite burden.MethodsSix biomarkers were measured in the plasma of children from schistosomiasis-endemic regions using ELISA. The concentration of soluble CD23 (sCD23) and lipopolysaccharide (LPS) was tested in 199 and 124 plasma samples, respectively, while interleukin-6 (IL-6), soluble triggering receptor expressed on myeloid (sTREM) cells, eotaxin-1, and fatty acid-binding protein (FABP) concentrations were tested in 30 plasma samples.ResultsThe concentration of IL-6, eotaxin-1, FABP, and LPS was similar between schistosome-infected and uninfected children. The schistosome-infected children had higher median levels of sTREM and sCD23 as compared to uninfected children, 119.0 (29.9–208.9) versus 10.7 (0.0–73.4) (p = 0.046) and 2,549.0 (1,899.0–3,356.0) vs. 2,035.0 (1,448.0–2,939.0) (p = 0.05), respectively. In addition, sTREM was positively correlated with egg density (p = 0.017).ConclusionOur data show that active schistosomiasis per se is associated with elevated levels of sTREM and sCD23. sTREM has potential diagnostic and prognostic values. However, these biomarkers did not distinguish between children with low egg burden and uninfected children.

Abstract Infections with intestinal worms, such as Ascaris lumbricoides, affect hundreds of millions of people in all tropical and subtropical regions of the world. Through large-scale deworming programs, World Health Organization aims to reduce moderate-to-heavy intensity infections below 1%. Current diagnosis and monitoring of these control programs are solely based on the detection of worm eggs in stool. Here we describe how metabolome analysis was used to identify the A. lumbricoides-specific urine biomarker 2-methyl pentanoyl carnitine (2-MPC). This biomarker was found to be 85.7% accurate in determining infection and 90.5% accurate in determining a moderate-to-heavy infection. Our results also demonstrate that there is a correlation between 2-MPC levels in urine and A. lumbricoides DNA detected in stool. Furthermore, the levels of 2-MPC in urine were shown to rapidly and strongly decrease upon administration of a standard treatment (single oral dose of 400 mg albendazole). In an Ascaris suum infection model in pigs, it was found that, although 2-MPC levels were much lower compared to humans, there was a significant association between urinary 2-MPC levels and both worm counts (p = 0.023) and the number of eggs per gram (epg) counts (p

The neglected tropical disease onchocerciasis, or river blindness, is caused by infection with the filarial nematode Onchocerca volvulus. Current estimates indicate that 17 million people are infected worldwide, the majority of them living in Africa. Today there are no non-invasive tests available that can detect ongoing infection, and that can be used for effective monitoring of elimination programs. In addition, to enable pharmacodynamic studies with novel macrofilaricide drug candidates, surrogate endpoints and efficacy biomarkers are needed but are non-existent. We describe the use of a multimodal untargeted mass spectrometry-based approach (metabolomics and lipidomics) to identify onchocerciasis-associated metabolites in urine and plasma, and of specific lipid features in plasma of infected individuals (O. volvulus infected cases: 68 individuals with palpable nodules; lymphatic filariasis cases: 8 individuals; non-endemic controls: 20 individuals). This work resulted in the identification of elevated concentrations of the plasma metabolites inosine and hypoxanthine as biomarkers for filarial infection, and of the urine metabolite cis-cinnamoylglycine (CCG) as biomarker for O. volvulus. During the targeted validation study, metabolite-specific cutoffs were determined (inosine: 34.2 ng/ml; hypoxanthine: 1380 ng/ml; CCG: 29.7 ng/ml) and sensitivity and specificity profiles were established. Subsequent evaluation of these biomarkers in a non-endemic population from a different geographical region invalidated the urine metabolite CCG as biomarker for O. volvulus. The plasma metabolites inosine and hypoxanthine were confirmed as biomarkers for filarial infection. With the availability of targeted LC-MS procedures, the full potential of these 2 biomarkers in macrofilaricide clinical trials, MDA efficacy surveys, and epidemiological transmission studies can be investigated.

Sulfakinin (SK)/cholecystokinin (CCK)-type neuropeptides regulate feeding and digestion in protostomes (e.g. insects) and chordates. Here, we characterised SK/CCK-type signalling for the first time in a non-chordate deuterostome – the starfish Asterias rubens (phylum Echinodermata). In this species, two neuropeptides (ArSK/CCK1, ArSK/CCK2) derived from the precursor protein ArSK/CCKP act as ligands for an SK/CCK-type receptor (ArSK/CCKR) and these peptides/proteins are expressed in the nervous system, digestive system, tube feet, and body wall. Furthermore, ArSK/CCK1 and ArSK/CCK2 cause dose-dependent contraction of cardiac stomach, tube foot, and apical muscle preparations in vitro, and injection of these neuropeptides in vivo triggers cardiac stomach retraction and inhibition of the onset of feeding in A. rubens. Thus, an evolutionarily ancient role of SK/CCK-type neuropeptides as inhibitory regulators of feeding-related processes in the Bilateria has been conserved in the unusual and unique context of the extra-oral feeding behaviour and pentaradial body plan of an echinoderm.

Abstract Background Currently, serodiagnosis of infection with the helminth parasite Onchocerca volvulus is limited to the Ov-16 IgG4 test, a test that has limited sensitivity and suboptimal specificity. In previous studies, we identified several linear epitopes that have the potential to supplement the diagnostic toolbox for onchocerciasis. Methods In this study three peptides, bearing in total six linear epitopes were transferred to a multiplex ELISA platform. This multiplex ELISA was used to assess the clinical utility of the peptide serology markers by analyzing sample sets from both O. volvulus endemic and non-endemic regions. Results The multiplex platform was shown to be reproducible and data obtained on the multiplex platform were comparable to the singleplex ELISA data. The clinical utility assessment showed that in a population of school-aged children from western Kenya, a virtually O. volvulus-free area, significant cross-reactivity with an as-yet to be determined immunogen was detected. Conclusions The observations made in this study invalidate the usefulness of the peptide serology markers for onchocerciasis detection. We discuss what could be the origin of this unexpected serological response, but also highlight the need for better characterized biobanks for biomarker discovery activities.

Abstract Background Vasopressin/oxytocin (VP/OT)-type neuropeptides are well known for their roles as regulators of diuresis, reproductive physiology and social behaviour. However, our knowledge of their functions is largely based on findings from studies on vertebrates and selected protostomian invertebrates. Little is known about the roles of VP/OT-type neuropeptides in deuterostomian invertebrates, which are more closely related to vertebrates than protostomes. Results Here, we have identified and functionally characterised a VP/OT-type signalling system comprising the neuropeptide asterotocin and its cognate G-protein coupled receptor in the starfish (sea star) Asterias rubens, a deuterostomian invertebrate belonging to the phylum Echinodermata. Analysis of the distribution of asterotocin and the asterotocin receptor in A. rubens using mRNA in situ hybridisation and immunohistochemistry revealed expression in the central nervous system (radial nerve cords and circumoral nerve ring), the digestive system (including the cardiac stomach) and the body wall and associated appendages. Informed by the anatomy of asterotocin signalling, in vitro pharmacological experiments revealed that asterotocin acts as a muscle relaxant in starfish, contrasting with the myotropic actions of VP/OT-type neuropeptides in vertebrates. Furthermore, in vivo injection of asterotocin had a striking effect on starfish behaviour—triggering fictive feeding where eversion of the cardiac stomach and changes in body posture resemble the unusual extra-oral feeding behaviour of starfish. Conclusions We provide a comprehensive characterisation of VP/OT-type signalling in an echinoderm, including a detailed anatomical analysis of the expression of both the VP/OT-type neuropeptide asterotocin and its cognate receptor. Our discovery that asterotocin triggers fictive feeding in starfish provides important new evidence of an evolutionarily ancient role of VP/OT-type neuropeptides as regulators of feeding in animals.

BackgroundEvidence indicates that whereas repeated rounds of mass drug administration (MDA) programs have reduced schistosomiasis prevalence to appreciable levels in some communities referred to here as responding villages (R). However, prevalence has remained high or less than anticipated in other areas referred to here as persistent hotspot villages (PHS). Using a cross-sectional quantitative approach, this study investigated the factors associated with sustained high Schistosoma mansoni prevalence in some villages despite repeated high annual treatment coverage in western Kenya.MethodWater contact sites selected based on observation of points where people consistently go to collect water, wash clothes, bathe, swim or play (young children), wash cars and harvest sand were mapped using hand-held smart phones on the Commcare platform. Quantitative cross-sectional surveys on behavioral characteristics were conducted using interviewer-based semi-structured questionnaires administered to assess water usage/contact patterns and open defecation. Questionnaires were administered to 15 households per village, 50 pupils per school and 1 head teacher per school. One stool and urine sample was collected from 50 school children aged 9-12 year old and 50 adults from both responding (R) and persistent hotspot (PHS) villages. Stool was analyzed by the Kato-Katz method for eggs of S. mansoni and soil-transmitted helminths. Urine samples were tested using the point-of-care circulating cathodic antigen (POC-CCA) test for detection of S. mansoni antigen.ResultsThere was higher latrine coverage in R (n = 6) relative to PHS villages (n = 6) with only 33% of schools in the PHS villages meeting the WHO threshold for boy: latrine coverage ratio versus 83.3% in R, while no villages met the girl: latrine ratio requirement. A higher proportion of individuals accessed unprotected water sources for both bathing and drinking (68.5% for children and 89% for adults) in PHS relative to R villages. In addition, frequency of accessing water sources was higher in PHS villages, with swimming being the most frequent activity. As expected based upon selection criteria, both prevalence and intensity of S. mansoni were higher in the PHS relative to R villages (prevalence: 43.7% vs 20.2%; P < 0.001; intensity: 73.8 ± 200.6 vs 22.2 ± 96.0, P < 0.0001), respectively.ConclusionUnprotected water sources and low latrine coverage are contributing factors to PHS for schistosomiasis in western Kenya. Efforts to increase provision of potable water and improvement in latrine infrastructure is recommended to augment control efforts in the PHS areas.

BackgroundSocioeconomic inequality including wealth distribution is a barrier to implementation of health policies. Wealth distribution can be measured effectively using household data on durable assets. Compared to other methods of analysing Socio-economic Status (SES) using durable assets, Multiple Correspondence Analysis (MCA) can create more reliable wealth quintiles. We therefore evaluated socioeconomic determinants of Schistosoma mansoni using MCA on household data among adult population in western Kenya. The hypothesis of this study was that MCA would be a useful predictor of S. mansoni prevalence and/or intensity.MethodologyTwelve villages, 6 villages that had showed the greatest decrease in S. mansoni prevalence (Responder villages) and 6 villages that showed relatively lower decrease (Hotspot villages) between the year 2011 and 2015 were randomly selected for this study. This was according to a previous Schistosomiasis Consortium for Operational Research and Elimination (SCORE) report from western Kenya. From each village, convenience sampling was used to identify 50 adults from 50 households for inclusion in this study. An interview with a questionnaire based upon MCA indicators was conducted. One stool sample from each of the 600 adults was examined based on four slides for S. mansoni eggs using Kato Katz technique. Mean Eggs per gram(EPG) was calculated by taking the average of the readings from the four slides. A log binomial regression model was used to identify the influence of the various age-groups(60 years), household size, wealth class, occupation, education status, main water supply, sex and sub-county of residence on S. mansoni infection. EPG was then compared across variables that were significant based on multivariate log binomial model analysis using a mixed model.Principal findingsOverall prevalence of S. mansoni was 41.3%. Significantly higher prevalence of S. mansoni were associated with males, those aged below 30 years, those who use unsafe water sources (unprotected wells, lakes and rivers), residents of Rachuonyo North, Hotspot villages and those earning livelihood from fishing. Only sex and household size were significant predictors in the multivariate model. Males were associated with significantly higher prevalence compared to the females (aPR = 1.37; 95% CI = 1.14-1.66). In addition, households with at least four persons had higher prevalence compared to those with less than four (aPR = 1.29; 95% CI = 1.03-1.61). However, there was no difference in prevalence between the wealth classes(broadly divided into poor and less poor categories). Intensity of infection (Mean EPG)was also significantly higher among males, younger age group, Rachuonyo North residents and Hotspot Villages.ConclusionSocioeconomic status based on an MCA model was not a contributing factor to S. mansoni prevalence and/or intensity possibly because the study populations were not sufficiently dissimilar. The use of convenience sampling to identify participants could also have contributed to the lack of significant findings.

Intestinal worms, or soil-transmitted helminths (STHs), affect hundreds of millions of people in all tropical and subtropical regions of the world. The most prevalent STH is Ascaris lumbricoides. Through large-scale deworming programs, World Health Organization aims to reduce morbidity, caused by moderate-to-heavy intensity infections, below 2%. In order to monitor these control programs, stool samples are examined microscopically for the presence of worm eggs. This procedure requires well-trained personnel and is known to show variability between different operators interpreting the slides. We have investigated whether ABA-1, one of the excretory-secretory products of A. lumbricoides can be used as a coproantigen marker for infection with this parasite. Polyclonal antibodies were generated and a coproantigen ELISA was developed. Using this ELISA, it was found that ABA-1 in stool detected Ascaris infection with a sensitivity of 91.5% and a specificity of 95.3%. Our results also demonstrate that there is a correlation between ABA-1 levels in stool and A. lumbricoides DNA detected in stool. Using a threshold of 18.2 ng/g stool the ABA-1 ELISA correctly assigned 68.4% of infected individuals to the moderate-to-heavy intensity infection group, with a specificity of 97.1%. Furthermore, the levels of ABA-1 in stool were shown to rapidly and strongly decrease upon administration of a standard anthelminthic treatment (single oral dose of 400 mg albendazole). In an Ascaris suum infection model in pigs, it was found that ABA-1 remained undetectable until day 28 and was detected at day 42 or 56, concurrent with the appearance of worm eggs in the stool. This report demonstrates that ABA-1 can be considered an Ascaris -specific coproantigen marker that can be used to monitor infection intensity. It also opens the path for development of point-of-care immunoassay-based tests to determine A. lumbricoides infection in stool at the sample collection site.

Age-related macular degeneration (AMD) is the leading cause of blindness in industrialized countries among people over 60 years. It has multiple triggers and risk factors, but despite intense research efforts, its pathomechanisms are currently not completely understood. AMD pathogenesis is characterized by soft drusen in Bruch’s membrane and involves the retinal pigment epithelium–Bruch’s membrane-choroid complex and adjacent structures, like photoreceptors. This study explores the potential of novel cultivation techniques to preserve photoreceptors in retinal explants to gain better insights in AMD pathology. The porcine retina explants were cultured for 4 and 8 days using three different explantation techniques, namely, control (photoreceptors facing down, touching the filter), filter (photoreceptors facing up, turned sample using a filter), and tweezers (photoreceptors facing up, turned sample using tweezers). Optical coherence tomography revealed that the tweezers method had the best capacity to limit thinning of the retinal explants. Both novel methods displayed advantages in maintaining outer segment thickness. Additionally, immunofluorescence evaluation revealed a better preservation of opsin+ cells and rhodopsin signal intensity in both novel methods, especially the tweezers method. Furthermore, RT-qPCR analysis demonstrated an upregulation of OPSIN and RHODOPSIN mRNA expression in tweezers samples at 8 days. Amacrine and bipolar cell numbers were not altered at day 4 of cultivation, while cultivation until 8 days led to reduced bipolar cell numbers. At 4 days, CALRETININ mRNA was upregulated in filter samples, but protein kinase C alpha expression was downregulated. Retinal ganglion cells were diminished in both novel techniques due to a direct physical contact with the insert. Remarkably, no difference in TUBB3 mRNA expression was detected among the techniques. Nevertheless, both novel methods exhibited an improved retention of photoreceptor cells. In conclusion, the tweezers technique was the most promising one. Due to the high homology of the porcine to the human retina, it provides a reasonable alternative to in vivo rodent models. Consequently, an adapted coculture system based on the current findings may serve as an ex vivo model suitable to analyze AMD pathomechanisms and novel therapeutic approaches.

Somatostatin (SS) and allatostatin-C (ASTC) are structurally and evolutionarily related neuropeptides that act as inhibitory regulators of physiological processes in mammals and insects, respectively. Here, we report the first molecular and functional characterization of SS/ASTC-type signalling in a deuterostome invertebrate—the starfish Asterias rubens (phylum Echinodermata). Two SS/ASTC-type precursors were identified in A. rubens (ArSSP1 and ArSSP2) and the structures of neuropeptides derived from these proteins (ArSS1 and ArSS2) were analysed using mass spectrometry. Pharmacological characterization of three cloned A. rubens SS/ASTC-type receptors (ArSSR1–3) revealed that ArSS2, but not ArSS1, acts as a ligand for all three receptors. Analysis of ArSS2 expression in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed stained cells/fibres in the central nervous system, the digestive system (e.g. cardiac stomach) and the body wall and its appendages (e.g. tube feet). Furthermore, in vitro pharmacological tests revealed that ArSS2 causes dose-dependent relaxation of tube foot and cardiac stomach preparations, while injection of ArSS2 in vivo causes partial eversion of the cardiac stomach. Our findings provide new insights into the molecular evolution of SS/ASTC-type signalling in the animal kingdom and reveal an ancient role of SS-type neuropeptides as inhibitory regulators of muscle contractility.

Neuropeptide signalling systems comprising peptide ligands and cognate receptors are evolutionarily ancient regulators of physiology and behaviour. However, there are challenges associated with determination of orthology between neuropeptides in different taxa. Orthologs of vertebrate neuropeptide-Y (NPY) known as neuropeptide-F (NPF) have been identified in protostome invertebrates, whilst prolactin-releasing peptide (PrRP) and short neuropeptide-F (sNPF) have been identified as paralogs of NPY/NPF in vertebrates and protostomes, respectively. Here we investigated the occurrence of NPY/NPF/PrRP/sNPF-related signalling systems in a deuterostome invertebrate phylum – the Echinodermata. Analysis of transcriptome/genome sequence data revealed loss of NPY/NPF-type signalling, but orthologs of PrRP-type neuropeptides and sNPF/PrRP-type receptors were identified in echinoderms. Furthermore, experimental studies revealed that the PrRP-type neuropeptide pQDRSKAMQAERTGQLRRLNPRF-NH2 is a potent ligand for a sNPF/PrRP-type receptor in the starfish Asterias rubens. Our findings indicate that PrRP-type and sNPF-type signalling systems are orthologous and originated as a paralog of NPY/NPF-type signalling in Urbilateria.

The identification of structurally related hypothalamic hormones that regulate blood pressure and diuresis (vasopressin, VP; CYFQNCPRG-NH2) or lactation and uterine contraction (oxytocin, OT; CYIQNCPLG-NH2) was a major advance in neuroendocrinology, recognized in the award of the Nobel Prize for Chemistry in 1955. Furthermore, the discovery of central actions of VP and OT as regulators of reproductive and social behavior in humans and other mammals has broadened interest in these neuropeptides beyond physiology into psychology. VP/OT-type neuropeptides and their G-protein coupled receptors originated in a common ancestor of the Bilateria (Urbilateria), with invertebrates typically having a single VP/OT-type neuropeptide and cognate receptor. Gene/genome duplications followed by gene loss gave rise to variety in the number of VP/OT-type neuropeptides and receptors in different vertebrate lineages. Recent advances in comparative transcriptomics/genomics have enabled discovery of VP/OT-type neuropeptides in an ever-growing diversity of invertebrate taxa, providing new opportunities to gain insights into the evolution of VP/OT-type neuropeptide function in the Bilateria. Here we review the comparative physiology of VP/OT-type neuropeptides in invertebrates, with roles in regulation of reproduction, feeding, and water/salt homeostasis emerging as common themes. For example, we highlight recent reports of roles in regulation of oocyte maturation in the sea-squirt Ciona intestinalis, extraoral feeding behavior in the starfish Asterias rubens and energy status and dessication resistance in ants. Thus, VP/OT-type neuropeptides are pleiotropic regulators of physiological processes, with evolutionarily conserved roles that can be traced back to Urbilateria. To gain a deeper understanding of the evolution of VP/OT-type neuropeptide function it may be necessary to not only determine the actions of the peptides but also to characterize the transcriptomic/proteomic/metabolomic profiles of cells expressing VP/OT-type precursors and/or VP/OT-type receptors within the framework of anatomically and functionally identified neuronal networks. Furthermore, investigation of VP/OT-type neuropeptide function in a wider range of invertebrate species is now needed if we are to determine how and when this ancient signaling system was recruited to regulate diverse physiological and behavioral processes in different branches of animal phylogeny and in contrasting environmental contexts.

The analysis of plasma microRNAs (miRNAs) has been widely used as a method for finding potential biomarkers for human diseases, especially those with a link to cancer. Methods of analyzing plasma miRNA have been thoroughly discussed from sample extraction to data modeling. However, some issues exist within the process that have rarely been talked about. Rice et al. discussed some issues in plasma miRNA studies, such as the lack of standard methodology including the use of different cycle threshold, time to plasma extraction, among others. These issues can lead to inconsistent data, and thus impact the result and assay reproducibility. Other external issues, such as batch effect and operator effect, may also indirectly impact the statistical analysis. Here, we discuss issues in plasma miRNA studies from a statistical point of view. The interaction effect of different ways of calculating fold-change, the choice of housekeeping genes, and methods of normalization are among the issues we discuss, with data demonstrations. P values are calculated and compared to determine the effect of those issues on statistical conclusions. Statistical methods such as analysis of variance and analysis of covariance are crucial in the analysis of miRNA but investigators are often confused about them; therefore, a brief explanation of these statistical methods is also included. In addition, 3-group classification is discussed, as it is often challenging, compared with 2-group classification.

Luqin is a neuropeptide that was discovered and named on account of its expression in left upper quadrant cells of the abdominal ganglion in the mollusc Aplysia californica. Subsequently, luqin-type peptides were identified as cardio-excitatory neuropeptides in other molluscs and a cognate receptor was discovered in the pond snail Lymnaea stagnalis. Phylogenetic analyses have revealed that orthologs of molluscan luqin-type neuropeptides occur in other phyla; these include neuropeptides in ecdysozoans (arthropods, nematodes) that have a C-terminal RYamide motif (RYamides) and neuropeptides in ambulacrarians (echinoderms, hemichordates) that have a C-terminal RWamide motif (RWamides). Furthermore, precursors of luqin-type neuropeptides typically have a conserved C-terminal motif containing two cysteine residues, although the functional significance of this is unknown. Consistent with the orthology of the neuropeptides and their precursors, phylogenetic and pharmacological studies have revealed that orthologous G-protein coupled receptors (GPCRs) mediate effects of luqin-type neuropeptides in spiralians, ecdysozoans, and ambulacrarians. Luqin-type signaling originated in a common ancestor of the Bilateria as a paralog of tachykinin-type signaling but, unlike tachykinin-type signaling, luqin-type signaling was lost in chordates. This may largely explain why luqin-type signaling has received less attention than many other neuropeptide signaling systems. However, insights into the physiological actions of luqin-type neuropeptides (RYamides) in ecdysozoans have been reported recently, with roles in regulation of feeding and diuresis revealed in insects and roles in regulation of feeding, egg laying, locomotion, and lifespan revealed in the nematode Caenorhabditis elegans. Furthermore, characterization of a luqin-type neuropeptide in the starfish Asterias rubens (phylum Echinodermata) has provided the first insights into the physiological roles of luqin-type signaling in a deuterostome. In conclusion, although luqin was discovered in Aplysia over 30 years ago, there is still much to be learnt about luqin-type neuropeptide signaling. This will be facilitated in the post-genomic era by the emerging opportunities for experimental studies on a variety of invertebrate taxa.

Abstract Neuropeptides are diverse and evolutionarily ancient regulators of physiological/behavioural processes in animals. Here we have investigated the evolution and comparative physiology of luqin-type neuropeptide signalling, which has been characterised previously in protostomian invertebrates. Phylogenetic analysis indicates that luqin-type receptors and tachykinin-type receptors are paralogous and probably originated in a common ancestor of the Bilateria. In the deuterostomian lineage, luqin-type signalling has been lost in chordates but interestingly it has been retained in ambulacrarians. Therefore, here we characterised luqin-type signalling for the first time in an ambulacrarian – the starfish Asterias rubens (phylum Echinodermata). A luqin-like neuropeptide with a C-terminal RWamide motif (ArLQ; EEKTRFPKFMRW-NH2) was identified as the ligand for two luqin-type receptors in A. rubens, ArLQR1 and ArLQR2. Furthermore, analysis of the expression of the ArLQ precursor using mRNA in situ hybridisation revealed expression in the nervous system, digestive system and locomotory organs (tube feet) and in vitro pharmacology revealed that ArLQ causes dose-dependent relaxation of tube feet. Accordingly, previous studies have revealed that luqin-type signalling regulates feeding and locomotor activity in protostomes. In conclusion, our phylogenetic analysis combined with characterisation of luqin-type signalling in a deuterostome has provided new insights into neuropeptide evolution and function in the animal kingdom.

Abstract Background Amongst the echinoderms the class Ophiuroidea is of particular interest for its phylogenetic position, ecological importance and developmental and regenerative biology. However, compared to other echinoderms, notably echinoids (sea urchins), relatively little is known about developmental changes in gene expression in ophiuroids. To address this issue, we have generated and assembled a large RNAseq data set of four key stages of development in the brittle star Amphiura filiformis and a de novo reference transcriptome of comparable quality to that of a model echinoderm—the sea urchin Strongylocentrotus purpuratus. Furthermore, we provide access to the new data via a web interface: http://www.echinonet.eu/shiny/Amphiura_filiformis/. Results We have identified highly conserved genes associated with the development of a biomineralised skeleton. We also identify important class-specific characters, including the independent duplication of the msp130 class of genes in different echinoderm classes and the unique occurrence of spicule matrix (sm) genes in echinoids. Using a new quantification pipeline for our de novo transcriptome, validated with other methodologies, we find major differences between brittle stars and sea urchins in the temporal expression of many transcription factor genes. This divergence in developmental regulatory states is more evident in early stages of development when cell specification begins, rather than when cells initiate differentiation. Conclusions Our findings indicate that there has been a high degree of gene regulatory network rewiring and clade-specific gene duplication, supporting the hypothesis of a convergent evolution of larval skeleton development in echinoderms.

Galanin is a neuropeptide that is widely expressed in the mammalian brain, where it regulates many physiological processes, including feeding and nociception. Galanin has been characterized extensively in jawed vertebrates (gnathostomes), but little is known about the galanin system in the most ancient extant vertebrate class, the jawless vertebrates or agnathans. Here, we identified and cloned a cDNA encoding the sea lamprey (Petromyzon marinus) galanin precursor (PmGalP). Sequence analysis revealed that PmGalP gives rise to two neuropeptides that are similar to gnathostome galanins and galanin message-associated peptides. Using mRNA in situ hybridization, the distribution of PmGalP-expressing neurons was mapped in the brain of larval and adult sea lampreys. This revealed PmGalP-expressing neurons in the septum, preoptic region, striatum, hypothalamus, prethalamus, and displaced cells in lateral areas of the telencephalon and diencephalon. In adults, the laterally migrated PmGalP-expressing neurons are observed in an area that extends from the ventral pallium to the lateral hypothalamus and prethalamus. The striatal and laterally migrated PmGalP-expressing cells of the telencephalon were not observed in larvae. Comparison with studies on jawed vertebrates reveals that the presence of septal and hypothalamic galanin-expressing neuronal populations is highly conserved in vertebrates. However, compared to mammals, there is a more restricted pattern of expression of the galanin transcript in the brain of lampreys. This work provides important new information on the early evolution of the galanin system in vertebrates and provides a genetic and neuroanatomical basis for functional analyses of the galanin system in lampreys.

ABSTRACT Murine studies suggest that the presence of some species of intestinal helminths is associated with changes in host microbiota composition and diversity. However, studies in humans have produced varied conclusions, and the impact appears to vary widely depending on the helminth species present. To demonstrate how molecular approaches to the human gut microbiome can provide insights into the complex interplay among disparate organisms, DNA was extracted from cryopreserved stools collected from residents of 5 rural Kenyan villages prior to and 3 weeks and 3 months following albendazole (ALB) therapy. Samples were analyzed by quantitative PCR (qPCR) for the presence of 8 species of intestinal parasites and by MiSeq 16S rRNA gene sequencing. Based on pretreatment results, the presence of neither Ascaris lumbricoides nor Necator americanus infection significantly altered the overall diversity of the microbiota in comparison with age-matched controls. Following ALB therapy and clearance of soil-transmitted helminths (STH), there were significant increases in the proportion of the microbiota made up by Clostridiales (P = 0.0002; average fold change, 0.57) and reductions in the proportion made up by Enterobacteriales (P = 0.0004; average fold change, −0.58). There was a significant posttreatment decrease in Chao1 richness, even among individuals who were uninfected pretreatment, suggesting that antimicrobial effects must be considered in any posttreatment setting. Nevertheless, the helminth-associated changes in Clostridiales and Enterobacteriales suggest that clearance of STH, and of N. americanus in particular, alters the gut microbiota. IMPORTANCE The gut microbiome is an important factor in human health. It is affected by what we eat, what medicines we take, and what infections we acquire. In turn, it affects the way we absorb nutrients and whether we have excessive intestinal inflammation. Intestinal worms may have an important impact on the composition of the gut microbiome. Without a complete understanding of the impact of mass deworming programs on the microbiome, it is impossible to accurately calculate the cost-effectiveness of such public health interventions and to guard against any possible deleterious side effects. Our research examines this question in a “real-world” setting, using a longitudinal cohort, in which individuals with and without worm infections are treated with deworming medication and followed up at both three weeks and three months posttreatment. We quantify the impact of roundworms and hookworms on gut microbial composition, suggesting that the impact is small, but that treatment of hookworm infection results in significant changes. This work points to the need for follow-up studies to further examine the impact of hookworm on the gut microbiota and determine the health consequences of the observed changes.

Subject-specific torque-driven computer simulation models employing single-joint torque generators have successfully simulated various sports movements with a key assumption that the maximal torque exerted at a joint is a function of the kinematics of that joint alone. This study investigates the effect on model accuracy of single-joint or two-joint torque generator representations within whole-body simulations of squat jumping and countermovement jumping. Two eight-segment forward dynamics subject-specific rigid body models with torque generators at five joints are constructed—the first model includes lower limb torques, calculated solely from single-joint torque generators, and the second model includes two-joint torque generators. Both models are used to produce matched simulations to a squat jump and a countermovement jump by varying activation timings to the torque generators in each model. The two-joint torque generator model of squat and countermovement jumps matched measured jump performances more closely (6% and 10% different, respectively) than the single-joint simulation model (10% and 24% different, respectively). Our results show that the two-joint model performed better for squat jumping and the upward phase of the countermovement jump by more closely matching faster joint velocities and achieving comparable amounts of lower limb joint extension. The submaximal descent phase of the countermovement jump was matched with similar accuracy by the two models (9% difference). In conclusion, a two-joint torque generator representation is likely to be more appropriate for simulating dynamic tasks requiring large joint torques and near-maximal joint velocities.

Abstract Background The Community Directed Intervention (CDI) strategy has been used to conduct various health interventions in Africa, including control of Neglected Tropical Diseases (NTDs). Although the CDI approach has shown good results in the control of onchocerciasis and lymphatic filariasis with respect to treatment coverage using community drug distributors, its utility in the control of schistosomiasis among urban poor is yet to be established. Using a longitudinal qualitative study, we explored the experiences, opportunities, challenges as well as recommendations of Community Health Workers (CHWs) after participation in annual mass drug administration (MDA) activities for schistosomiasis using the CDI approach in an urban setting. Methods Unstructured open-ended group discussions were conducted with CHWs after completion of annual MDA activities. Narratives were obtained from CHWs using a digital audio recorder during the group discussions, transcribed verbatim and translated into English where applicable. Thematic decomposition of data was done using ATLAS.ti. software, and themes explored using the principle of interpretative phenomenological analysis (IPA). Results From the perspective of the CHWs, opportunities for implementing CDI in urban settings, included the presence of CHWs, their supervisory structures and their knowledge of intervention areas, and opportunity to integrate MDA with other health interventions. Several challenges were mentioned with regards to implementing MDA using the CDI strategy among them lack of incentives, fear of side effects, misconceptions regarding treatment and mistrust, difficulties working in unsanitary environmental conditions, insecurity, and insufficient time. A key recommendation in promoting more effective MDA using the CDI approach was allocation of more time to the exercise. Conclusion Findings from this study support the feasibility of using CDI for implementing MDA for schistosomiasis in informal settlements of urban areas. Extensive community sensitization and provision of incentives may help address the aforementioned challenges associated with implementing MDA using the CDI strategy. Opportunities highlighted in this study may be of value to other programmes that may be considering the adoption of the CDI strategy for rolling out interventions in the urban setting.

The nervous system of the free-living planktonic larvae of sea urchins is relatively “simple,” but sufficiently complex to enable sensing of the environment and control of swimming and feeding behaviors. At the pluteus stage of development, the nervous system comprises a central ganglion of serotonergic neurons located in the apical organ and sensory and motor neurons associated with the ciliary band and the gut. Neuropeptides are key mediators of neuronal signaling in nervous systems but currently little is known about neuropeptidergic systems in sea urchin larvae. Analysis of the genome sequence of the sea urchin Strongylocentrotus purpuratus has enabled the identification of 38 genes encoding neuropeptide precursors (NP) in this species. Here we characterize for the first time the expression of nine of these NP genes in S. purpuratus larvae, providing a basis for a functional understanding of the neurochemical organization of the larval nervous system. In order to accomplish this we used single and double in situ hybridization, coupled with immunohistochemistry, to investigate NP gene expression in comparison with known markers (e.g., the neurotransmitter serotonin). Several sub-populations of cells that express one or more NP genes were identified, which are located in the apica organ, at the base of the arms, around the mouth, in the ciliary band and in the mid- and fore-gut. Furthermore, high levels of cell proliferation were observed in neurogenic territories, consistent with an increase in the number of neuropeptidergic cells at late larval stages. This study has revealed that the sea urchin larval nervous system is far more complex at a neurochemical level than was previously known. Our NP gene expression map provides the basis for future work, aimed at understanding the role of diverse neuropeptides in control of various aspects of embryonic and larval behavior.

Neuropeptides in deuterostomian invertebrates that have an Asn-Gly motif (NG peptides) have been identified as orthologs of vertebrate neuropeptide-S (NPS)-type peptides and protostomian crustacean cardioactive peptide (CCAP)-type neuropeptides. To obtain new insights into the physiological roles of NG peptides in deuterostomian invertebrates, here we have characterized the NG peptide signaling system in an echinoderm—the starfish Asterias rubens. The neuropeptide NGFFYamide was identified as the ligand for an A. rubens NPS/CCAP-type receptor, providing further confirmation that NG peptides are orthologs of NPS/CCAP-type neuropeptides. Using mRNA in situ hybridization, cells expressing the NGFFYamide precursor transcript were revealed in the radial nerve cords, circumoral nerve ring, coelomic epithelium, apical muscle, body wall, stomach, and tube feet of A. rubens, indicating that NGFFYamide may have a variety of physiological roles in starfish. One of the most remarkable aspects of starfish biology is their feeding behavior, where the stomach is everted out of the mouth over the soft tissue of prey. Previously, we reported that NGFFYamide triggers retraction of the everted stomach in A. rubens and here we show that in vivo injection of NGFFYamide causes a significant delay in the onset of feeding on prey. To investigate roles in regulating other aspects of starfish physiology, we examined the in vitro effects of NGFFYamide and found that it causes relaxation of acetylcholine-contracted apical muscle preparations and induction of tonic and phasic contraction of tube feet. Furthermore, analysis of the effects of in vivo injection of NGFFYamide on starfish locomotor activity revealed that it causes a significant reduction in mean velocity and distance traveled. Interestingly, experimental studies on mammals have revealed that NPS is an anxiolytic that suppresses appetite and induces hyperactivity in mammals. Our characterization of the actions of NGFFYamide in starfish indicates that NPS/NG peptide/CCAP-type signaling is an evolutionarily ancient regulator of feeding and locomotion.

Calcitonin (CT) is a peptide hormone released by the thyroid gland that regulates blood Ca2+ levels in mammals. The CT gene is alternatively spliced, with one transcript encoding CT and another transcript encoding the CT-like neuropeptide calcitonin-gene related peptide (α-CGRP), which is a powerful vasodilator. Other CT-related peptides in vertebrates include adrenomedullin, amylin, and intermedin, which also act as smooth muscle relaxants. The evolutionary origin of CT-type peptides has been traced to the bilaterian common ancestor of protostomes and deuterostomes and a CT-like peptide (DH31) has been identified as a diuretic hormone in some insect species. However, little is known about the physiological roles of CT-type peptides in other invertebrates. Here we characterized a CT-type neuropeptide in a deuterostomian invertebrate—the starfish Asterias rubens (Phylum Echinodermata). A CT-type precursor cDNA (ArCTP) was sequenced and the predicted structure of the peptide (ArCT) derived from ArCTP was confirmed using mass spectrometry. The distribution of ArCTP mRNA and the ArCT peptide was investigated using in situ hybridization and immunohistochemistry, respectively, revealing stained cells/processes in the nervous system, digestive system, and muscular organs, including the apical muscle and tube feet. Investigation of the effects of synthetic ArCT on in vitro preparations of the apical muscle and tube feet revealed that it acts as a relaxant, causing dose-dependent reversal of acetylcholine-induced contraction. Furthermore, a muscle relaxant present in whole-animal extracts of another starfish species, Patiria pectinifera, was identified as an ortholog of ArCT and named PpCT. Consistent with the expression pattern of ArCTP in A. rubens, RT-qPCR revealed that in P. pectinifera the PpCT precursor transcript is more abundant in the radial nerve cords than in other tissues/organs analyzed. In conclusion, our findings indicate that the physiological action of CT-related peptides as muscle relaxants in vertebrates may reflect an evolutionarily ancient role of CT-type neuropeptides that can be traced back to the common ancestor of deuterostomes.

Since 2011, cohorts of schoolchildren in regions bordering Lake Victoria in Kenya and Tanzania have been investigated for morbidity caused by Schistosoma mansoni infection. Despite being neighbouring countries with similar lifestyles and ecological environments, Tanzanian schoolchildren had lower S. mansoni prevalence and intensity and they were taller and heavier, fewer were wasted and anaemic, and more were physical fit compared to their Kenyan peers. The aim of the present study was to evaluate whether diet and school-related markers of socioeconomic status (SES) could explain differences in morbidity beyond the effect of infection levels.Parasitological and morbidity data from surveys in 2013-2014 were compared with information on diet and school-related markers of SES collected in 2015 using questionnaires. A total of 490 schoolchildren (163 Kenyans and 327 Tanzanians) aged 9-11 years provided data. A higher proportion of Tanzanian pupils (69.4%, 95% CI: 64.3-74.5) knew where to wash hands after toilet visits compared to Kenyan pupils (48.5%, 95% CI: 40.9-56.1; P

Objective To determine if the prevalence of schistosomiasis in children aged 9- 12 years is associated with the prevalence in 5-8-year-olds and adults after preventive chemotherapy in schools or the community. Methods We combined data from four community-randomized, preventive chemotherapy trials in treatment-naive populations in Cote d'Ivoire, Kenya and the United Republic of Tanzania during 2010-2016 according to the number of praziquantel treatments and the delivery method. Schistosoma mansoni infection was sought on two slides prepared from each participant's first stool using the Kato-Katz technique. We assessed associations between S. mansoni prevalence in 9-12-year-olds and 5- 8-year-olds and adults in the community before and after treatment using Bayesian regression models. Findings Stool samples from 47 985 5-8-year-olds, 81 077 9-12-year-olds and 20 492 adults were analysed. We found associations between the prevalence in 9-12-year-olds and that in 5-8-year-olds and adults after preventive treatment, even when only school-age children were treated. When the prevalence in 9-12-year-olds was under 10%, the prevalence in 5-8-year-olds was consistently under 10%. When the prevalence in 9-12-year-olds was under 50%, the prevalence in adults after two or four rounds of preventive chemotherapy was 10%-15% lower than before chemotherapy. Post-chemotherapy age-group associations were consistent with pre-chemotherapy associations in this analysis and previous studies. Conclusion The prevalence of S. mansoni infection in 9-12-year-olds was associated with the prevalence in other age groups and could be used to guide community treatment decisions. Abstracts in [phrase omitted], Francais, [phrase omitted] and Espanol at the end of each article. [phrase omitted] Objectif Determiner si la prevalence de la schistosomiase chez les enfants de 9 a 12 ans est associee a celle observee chez les 5-8 ans et les adultes apres une chimiotherapie preventive au sein des ecoles ou de la communaute. Methodes Nous avons regroupe les donnees provenant de quatre essais randomises de chimiotherapie preventive menes en milieu communautaire aupres de populations n'ayant jamais ete traitees en Cote d'Ivoire, au Kenya et en Republique-Unie de Tanzanie entre 2010 et 2016, en fonction du nombre de traitements au praziquantel et du mode d'administration. Une infection a Schistosoma mansoni a ete recherchee sur deux lames preparees a partir des premieres selles de chaque participant, a l'aide de la technique de Kato-Katz. Nous avons employe des modeles de regression bayesienne qui nous ont permis d'identifier un rapport entre la prevalence de S. mansoni au sein de la communaute chez les 9-12 ans d'une part, et chez les 5-8 ans et les adultes de l'autre, avant et apres traitement. Resultats Les echantillons de selles de 47 985 enfants ages de 5 a 8 ans, 81 077 enfants de 9 a 12 ans et 20 492 adultes ont ete analyses. Nous avons constate qu'apres un traitement preventif, la prevalence chez les 9-12 ans ainsi que chez les 5-8 ans et les adultes etait liee, meme quand seuls les enfants d'age scolaire etaient traites. Lorsque la prevalence chez les 9-12 ans etait inferieure a 10%, celle chez les 5-8 ans etait systematiquement sous les 10%. Lorsque la prevalence chez les 9-12 ans etait inferieure a 50%, celle chez les adultes apres deux ou quatre traitements par chimiotherapie preventive etait 10 a 15% plus faible qu'avant toute chimiotherapie. Les liens par categorie d'age en post-chimiotherapie etaient coherents avec ceux en pre-chimiotherapie, tant dans la presente analyse que dans de precedentes etudes. Conclusion La prevalence de l'infection a S. mansoni chez les 9-12 ans etait associee a la prevalence dans d'autres categories d'age, ce qui pourrait servir a orienter les decisions de prise en charge au sein de la communaute. [phrase omitted] Objetivo Determinar si la prevalencia de la esquistosomiasis en ninos de 9 a 12 anos esta asociada con la prevalencia en ninos de 5 a 8 anos y adultos tras la quimioterapia preventiva en escuelas o en la comunidad. Metodos Se combinaron datos de cuatro ensayos aleatorizados a nivel comunitario de quimioterapia preventiva en poblaciones sin tratamiento en Costa de Marfil, Kenia y la Republica Unida de Tanzania entre 2010 y 2016 segun el numero de tratamientos con praziquantel y el metodo de administracion. La infeccion por Schistosoma mansoni se busco en dos laminillas preparadas a partir de las primeras heces de cada participante mediante la tecnica de Kato-Katz. Se evaluaron las asociaciones entre la prevalencia de S. mansoni en ninos de 9 a 12 anos y de 5 a 8 anos y adultos en la comunidad antes y despues del tratamiento mediante modelos de regresion bayesiana. Resultados Se analizaron muestras de heces de 47 985 ninos de 5 a 8 anos, 81 077 ninos de 9 a 12 anos y 20 492 adultos. Se encontraron asociaciones entre la prevalencia en ninos de 9 a 12 anos y la de ninos de 5 a 8 anos y adultos tras el tratamiento preventivo, incluso cuando solo se trato a ninos en edad escolar. Cuando la prevalencia en ninos de 9 a 12 anos era inferior al 10%, la prevalencia en ninos de 5 a 8 anos era siempre inferior al 10%. Cuando la prevalencia en ninos de 9 a 12 anos era inferior al 50%, la prevalencia en adultos despues de dos o cuatro ciclos de quimioterapia preventiva era entre un 10% y un 15% inferior que antes de la quimioterapia. Las asociaciones entre grupos de edad tras la quimioterapia fueron coherentes con las asociaciones previas a la quimioterapia en este analisis y en estudios anteriores. Conclusion La prevalencia de la infeccion por S. mansoni en ninos de 9 a 12 anos se asocio con la prevalencia en otros grupos de edad. Ademas, podria utilizarse para orientar las decisiones de tratamiento en la comunidad., Introduction Control programmes for schistosomiasis, the human disease caused by worms of the genus Schistosoma, focus on collecting and evaluating data from school-age children. (1) The use of school-age children [...]

Homologs of the vertebrate neuropeptide gonadotropin-releasing hormone (GnRH) have been identified in invertebrates, including the insect neuropeptide corazonin (CRZ). Recently, we reported the discovery of GnRH-type and CRZ-type signaling systems in an echinoderm, the starfish Asterias rubens, demonstrating that the evolutionary origin of paralogous GnRH-type and CRZ-type neuropeptides can be traced back to the common ancestor of protostomes and deuterostomes. Here, we have investigated the physiological roles of the GnRH-type (ArGnRH) and the CRZ-type (ArCRZ) neuropeptides in A. rubens, using mRNA in situ hybridization, immunohistochemistry and in vitro pharmacology. ArGnRH precursor (ArGnRHP)-expressing cells and ArGnRH-immunoreactive cells and/or processes are present in the radial nerve cords, circumoral nerve ring, digestive system (e.g., cardiac stomach and pyloric stomach), body wall-associated muscle (apical muscle), and appendages (tube feet, terminal tentacle). The general distribution of ArCRZ precursor (ArCRZP)-expressing cells is similar to that of ArGnRHP, but with specific local differences. For example, cells expressing ArGnRHP are present in both the ectoneural and hyponeural regions of the radial nerve cords and circumoral nerve ring, whereas cells expressing ArCRZP were only observed in the ectoneural region. In vitro pharmacological experiments revealed that both ArGnRH and ArCRZ cause contraction of cardiac stomach, apical muscle, and tube foot preparations. However, ArGnRH was more potent/effective than ArCRZ as a contractant of the cardiac stomach, whereas ArCRZ was more potent/effective than ArGnRH as a contractant of the apical muscle. These findings demonstrate that both ArGnRH and ArCRZ are myoexcitatory neuropeptides in starfish, but differences in their expression patterns and pharmacological activities are indicative of distinct physiological roles. This is the first study to investigate the physiological roles of both GnRH-type and CRZ-type neuropeptides in a deuterostome, providing new insights into the evolution and comparative physiology of these paralogous neuropeptide signaling systems in the Bilateria.

Neuropeptides are a diverse class of intercellular signalling molecules that mediate neuronal regulation of many physiological and behavioural processes. Recent advances in genome/transcriptome sequencing are enabling identification of neuropeptide precursor proteins in species from a growing variety of animal taxa, providing new insights into the evolution of neuropeptide signalling. Here, detailed analysis of transcriptome sequence data from three brittle star species, Ophionotus victoriae, Amphiura filiformis and Ophiopsila aranea, has enabled the first comprehensive identification of neuropeptide precursors in the class Ophiuroidea of the phylum Echinodermata. Representatives of over 30 bilaterian neuropeptide precursor families were identified, some of which occur as paralogues. Furthermore, homologues of endothelin/CCHamide, eclosion hormone, neuropeptide-F/Y and nucleobinin/nesfatin were discovered here in a deuterostome/echinoderm for the first time. The majority of ophiuroid neuropeptide precursors contain a single copy of a neuropeptide, but several precursors comprise multiple copies of identical or non-identical, but structurally related, neuropeptides. Here, we performed an unprecedented investigation of the evolution of neuropeptide copy number over a period of approximately 270 Myr by analysing sequence data from over 50 ophiuroid species, with reference to a robust phylogeny. Our analysis indicates that the composition of neuropeptide ‘cocktails’ is functionally important, but with plasticity over long evolutionary time scales.

Abstract Background Schistosomiasis studies in western Kenya have mainly focused on the intestinal form, with evidence of urinary schistosomiasis remaining anecdotal. Detailed disease mapping has been carried out predominantly along the shores of Lake Victoria, but there is a paucity of information on intestinal and urinary schistosomiasis in inland sites. Methods This cross-sectional survey of 3,487 children aged 7–18 years from 95 schools in south Nyanza, western Kenya determined the prevalence, infection intensity, and geographical distribution of Schistosoma haematobium, evaluating its co-endemicity with Schistosoma mansoni and soil-transmitted helminths (STHs). Helminth eggs were analyzed from single urine (for S. haematobium) and stool (for S. mansoni and STHs) samples by centrifugation and Kato-Katz, respectively. Hematuria was used as a proxy indicator for S. haematobium. Schools and water bodies (ponds, water-points, streams, dams and rivers) were mapped using Geographical Information System and prevalence maps obtained using ArcView GIS Software. Results S. haematobium infections with an overall prevalence of 9.3% (95% CI = 8.4-10.2%) were mostly prevalent in Rachuonyo, 22.4% (95% CI = 19.2-25.9% and 19.7 eggs/10 ml) and Migori, 10.7% (95% CI = 9.2-12.3% and 29.5 eggs/10 ml) districts, particularly around Kayuka pond and Ongoche river respectively. Overall infections correlated with hematuria (r = 0.9, P

This paper deals with separable and entangled qudits | ψ d 〉 (quantum states in dimension d) constructed from Dicke states made of N = d − 1 qubits. Such qudits present the property to be totally symmetric under the interchange of the N qubits. We discuss the notion of perma-concurrence P d for the qudit | ψ d 〉 , introduced by the authors (Entropy 2018, 20, 292), as a parameter for characterizing the entanglement degree of | ψ d 〉 . For d = 3 , the perma-concurrence P 3 constitutes an alternative to the concurrence C for symmetric two-qubit states. We give several expressions of P d (in terms of matrix permanent and in terms of unit vectors of R 3 pointing on the Bloch sphere) and precise the range of variation of P d (going from separable to maximally entangled states). Numerous examples are presented for P d . Special attention is devoted to states of W type and to maximally entangled states of Bell and Greenberger−Horne−Zeilinger type.

Efficient throwing mechanics is predicated on a pitcher’s ability to perform a sequence of movements of body segments, which progresses from the legs, pelvis, and trunk to the smaller, distal arm segments. Each segment plays a vital role in achieving maximum ball velocity at ball release. The perturbation of one joint angle has an effect on the ball release speed. An eight-segment angle-driven simulation model of the trunk, upper limbs and ball was developed to determine which joint angle changes have the most influence on ball release speed in overarm throwing for an experienced pitcher. Fifteen overarm throwing trials were recorded, and the joint angle time histories of each trial were input into the simulation model. Systematically replacing each joint angle time history with a constant value showed that overarm throwing was sensitive (≥5 m/s effect on ball release speed) to trunk extension/flexion and upper arm external/internal rotation, and very sensitive (≥10 m/s effect) to forearm extension/flexion. Computer simulation allows detailed analysis and complete control to investigate contributions to performance, and the key joint angle changes for overarm throwing were identified in this analysis.