Soil-transmitted helminthiasis in Laos: A community-wide cross-sectional study of humans and dogs in a mass drug administration environment

We conducted a community cross-sectional survey of soil-transmitted helminthiasis in humans and dogs in four provinces in northern Laos. We collected and tested human and dog fecal samples and analyzed results against sociodemographic data. The prevalence of Ascaris lumbricoides, Trichuris trichiura, hookworm, and Strongyloides stercoralis was 26.1% (95% confidence interval [CI,1 = 23.7-28.4%), 41.5% (95% CI = 38.8-44.1%), 46.3% (95% CI = 43.3-49.0%), and 8.9% (95% CI = 7.4-10.4%), respectively. We observed strong heterogeneity for helminthiasis by ethnicity, province, and wealth status, which coincided with a risk profile demonstrating that Mon-Khmer persons and the poorest households are highly vulnerable. Necator americanus was the dominant hookworm species infecting humans and Ancylostoma ceylanicum was the only Ancylastoma species detected. Hookworm prevalence in village dogs was 94%, and the dominant species was A. ceylanicum. Necator americanus was also detected in dogs. It appears that dogs have a role in human hookworm transmission and warrant further investigation

Recruitment, growth and mortality of an Antarctic hexactinellid sponge, Anoxycalyx joubini.

Polar ecosystems are sensitive to climate forcing, and we often lack baselines to evaluate changes. Here we report a nearly 50-year study in which a sudden shift in the population dynamics of an ecologically important, structure-forming hexactinellid sponge, Anoxycalyx joubini was observed. This is the largest Antarctic sponge, with individuals growing over two meters tall. In order to investigate life history characteristics of Antarctic marine invertebrates, artificial substrata were deployed at a number of sites in the southern portion of the Ross Sea between 1967 and 1975. Over a 22-year period, no growth or settlement was recorded for A. joubini on these substrata; however, in 2004 and 2010, A. joubini was observed to have settled and grown to large sizes on some but not all artificial substrata. This single settlement and growth event correlates with a region-wide shift in phytoplankton productivity driven by the calving of a massive iceberg. We also report almost complete mortality of large sponges followed over 40 years. Given our warming global climate, similar system-wide changes are expected in the future

Endemicity of Zoonotic Diseases in Pigs and Humans in Lowland and Upland Lao PDR: Identification of Socio-cultural Risk Factors

In Lao People's Democratic Republic pigs are kept in close contact with families. Human risk of infection with pig zoonoses arises from direct contact and consumption of unsafe pig products. This cross-sectional study was conducted in Luang Prabang (north) and Savannakhet (central-south) Provinces. A total of 59 villages, 895 humans and 647 pigs were sampled and serologically tested for zoonotic pathogens including: hepatitis E virus (HEV), Japanese encephalitis virus (JEV) and Trichinella spiralis; In addition, human sera were tested for Taenia spp. and cysticercosis. Seroprevalence of zoonotic pathogens in humans was high for HEV (Luang Prabang: 48.6%, Savannakhet: 77.7%) and T. spiralis (Luang Prabang: 59.0%, Savannakhet: 40.5%), and lower for JEV (around 5%), Taenia spp. (around 3%) and cysticercosis (Luang Prabang: 6.1, Savannakhet 1.5%). Multiple correspondence analysis and hierarchical clustering of principal components was performed on descriptive data of human hygiene practices, contact with pigs and consumption of pork products. Three clusters were identified: Cluster 1 had low pig contact and good hygiene practices, but had higher risk of T. spiralis. Most people in cluster 2 were involved in pig slaughter (83.7%), handled raw meat or offal (99.4%) and consumed raw pigs' blood (76.4%). Compared to cluster 1, cluster 2 had increased odds of testing seropositive for HEV and JEV. Cluster 3 had the lowest sanitation access and had the highest risk of HEV, cysticercosis and Taenia spp. Farmers which kept their pigs tethered (as opposed to penned) and disposed of manure in water sources had 0.85 (95% CI: 0.18 to 0.91) and 2.39 (95% CI: 1.07 to 5.34) times the odds of having pigs test seropositive for HEV, respectively. The results have been used to identify entry-points for intervention and management strategies to reduce disease exposure in humans and pigs, informing control activities in a cysticercosis hyper-endemic village

Determination of intracellular glutathione and glutathione disulfide using high performance liquid chromatography with acidic potassium permanganate chemiluminescence detection

Measurement of glutathione (GSH) and glutathione disulfide (GSSG) is a crucial tool to assess cellular redox state. Herein we report a direct approach to determine intracellular GSH based on a rapid chromatographic separation coupled with acidic potassium permanganate chemiluminescence detection, which was extended to GSSG by incorporating thiol blocking and disulfide bond reduction. Importantly, this simple procedure avoids derivatisation of GSH (thus minimising auto-oxidation) and overcomes problems encountered when deriving the concentration of GSSG from &lsquo;total GSH&rsquo;. The linear range and limit of detection for both analytes were 7.5 &times; 10&minus;7 to 1 &times; 10&minus;5 M, and 5 &times; 10&minus;7 M, respectively. GSH and GSSG were determined in cultured muscle cells treated for 24 h with glucose oxidase (0, 15, 30, 100, 250 and 500 mU mL&minus;1), which exposed them to a continuous source of reactive oxygen species (ROS). Both analyte concentrations were greater in myotubes treated with 100 or 250 mU mL&minus;1 glucose oxidase (compared to untreated controls), but were significantly lower in myotubes treated with 500 mU mL&minus;1 (p &lt; 0.05), which was rationalised by considering measurements of H2O2 and cell viability. However, the GSH/GSSG ratio in myotubes treated with 100, 250 and 500 mU mL&minus;1 glucose oxidase exhibited a dose-dependent decrease that reflected the increase in intracellular ROS.<br /

A three-dimensional model of primary bovine endometrium using an electrospun scaffold

Endometrial stromal and epithelial cell function is typically studied in vitro using standard two-dimensional monocultures, but these cultures fail to reflect the complex three-dimensional (3D) architecture of tissue. A 3D model of bovine endometrium that reflects the architectural arrangement of in vivo tissue would beneficially assist the study of tissue function. An electrospun polyglycolide (PGA) scaffold was selected to grow a 3D model of primary bovine endometrial epithelial and stromal cells, that reflects the architecture of the endometrium for the study of pathophysiology. Electrospun scaffolds were seeded with stromal and epithelial cells, and growth was assessed using histological techniques. Prostaglandin E2 and prostaglandin F2α responsiveness of endometrial scaffold constructs was tested using oxytocin plus arachidonic acid (OT + AA) or lipopolysaccharide (LPS). Stromal and epithelial cells growing on the electrospun scaffold had an architectural arrangement that mimicked whole tissue, deposited fibronectin, had appropriate expression of vimentin and cytokeratin and were responsive to OT + AA and LPS, as measured by prostaglandin accumulation. In conclusion, a functional 3D model of stromal and epithelial cells was developed using a PGA electrospun scaffold which may be used to study endometrial pathophysiology

Energy depletion and opportunistic microbial colonisation in white syndrome lesions from corals across the Indo-Pacific

Corals are dependent upon lipids as energy reserves to mount a metabolic response to biotic and abiotic challenges. This study profiled lipids, fatty acids, and microbial communities of healthy and white syndrome (WS) diseased colonies of Acropora hyacinthus sampled from reefs in Western Australia, the Great Barrier Reef, and Palmyra Atoll. Total lipid levels varied significantly among locations, though a consistent stepwise decrease from healthy tissues from healthy colonies (HH) to healthy tissue on WS-diseased colonies (HD; i.e. preceding the lesion boundary) to diseased tissue on diseased colonies (DD; i.e. lesion front) was observed, demonstrating a reduction in energy reserves. Lipids in HH tissues were comprised of high energy lipid classes, while HD and DD tissues contained greater proportions of structural lipids. Bacterial profiling through 16S rRNA gene sequencing and histology showed no bacterial taxa linked to WS causation. However, the relative abundance of Rhodobacteraceae-affiliated sequences increased in DD tissues, suggesting opportunistic proliferation of these taxa. While the cause of WS remains inconclusive, this study demonstrates that the lipid profiles of HD tissues was more similar to DD tissues than to HH tissues, reflecting a colony-wide systemic effect and provides insight into the metabolic immune response of WS-infected Indo-Pacific corals

Dynamics and risk of transmission of bovine tuberculosis in the emerging dairy regions of Ethiopia

The Ethiopian government has several initiatives to expand and intensify the dairy industry; however, the risk of bovine tuberculosis (bTB) spread is a challenge. To assess the rate of expansion and risk factors for transmission of bTB within-herds, we carried out a repeated cross-sectional survey at two time points, 2016/17 and 2018, in three regional cities, namely, Gondar, Hawassa and Mekelle, representing the emerging dairy belts of Ethiopia. The total number of herds involved was 128, comprising an average of 2303 cattle in each round. The Single Intradermal Comparative Cervical Tuberculin (SICCT) test was used to identify reactor status and data on herd-level risk factors were collected using a structured questionnaire. In the first survey, the apparent prevalence of bTB, as measured by the SICCT test, was 4.5% (95% CI 3.7-5.4%) at the individual animal-level and 24% (95% CI 17.5-32%) at the herd-level. There was no statistically significant change in the overall apparent prevalence or regional distribution at the second survey, consistent with the infection being endemic. The incidence rate was estimated at 3.6 (95% CI 2.8-4.5) and 6.6 (95% CI 3.0-12.6) cases/100 cattle (or herd)-years at the animal- and herd-levels, respectively. Risk factors significantly associated with the within-herd transmission of bTB were age group and within-herd apparent prevalence at the start of the observation period. We noted that farmers voluntarily took steps to remove reactor cattle from their herds as a consequence of the information shared after the first survey. Removal of reactors between surveys was associated with a reduced risk of transmission within these herds. However, with no regulatory barriers to the sale of reactor animals, such actions could potentially lead to further spread between herds. We therefore advocate the importance of setting up regulations and then establishing a systematic bTB surveillance programme to monitor the impact prior to implementing any control measures in Ethiopia

Characterization of lethal inhalational infection with Francisella tularensis in the common marmoset (Callithrix jacchus)

The intracellular Gram-negative pathogen Francisella tularensis is the causative agent of tularaemia and is prevalent in many countries in the northern hemisphere. To determine whether the common marmoset (Callithrix jacchus) would be a suitable non-human primate model of inhalational tularaemia, a pathophysiology study was undertaken. Ten animals were challenged with ∼102 c.f.u. F. tularensis strain SCHU S4 (F. tularensis subsp. tularensis). To look for trends in the infection, pairs of animals were sacrificed at 24 h intervals between 0 and 96 h post-challenge and blood and organs were assessed for bacteriology, pathology and haematological and immunological parameters. The first indication of infection was a raised core temperature at 3 days post-challenge. This coincided with a number of other factors: a rapid increase in the number of bacteria isolated from all organs, more pronounced gross pathology and histopathology, and an increase in the immunological response. As the disease progressed, higher bacterial and cytokine levels were detected. More extensive pathology was observed, with multifocal lesions seen in the lungs, liver and spleen. Disease progression in the common marmoset appears to be consistent with human clinical and pathological features of tularaemia, indicating that this may be a suitable animal model for the investigation of novel medical interventions such as vaccines or therapeutics

Measuring the impact on impedance spectroscopy of pseudo-reference electrode accumulations

Silver is widely used on screen-printed electrodes (SPEs) to provide a reference potential for electrochemical measurements such as impedance spectroscopy (EIS). The redox activity between silver and electrolyte in SPE-based experiments is rarely reported in detail, despite the critical reliance of potentiometric measurement accuracy on the predictability of reactions at reference electrodes. In this work, potassium ferrous cyanides typically used as electrolyte components were shown to adsorb to the silver surface when applied to SPEs. EIS was performed in a two-electrode configuration to demonstrate redox instability at the silver electrode, highlighting the need for evaluation of similar systems to prevent reference potential drift caused by side reaction depositions

Engineering the Redox Potential over a Wide Range within a New Class of FeS Proteins

Abstract: MitoNEET is a newly discovered mitochondrial protein and a target of the TZD class of antidiabetes drugs. MitoNEET is homodimeric with each protomer binding a [2Fe-2S] center through a rare 3-Cys and 1-His coordination geometry. Both the fold and the coordination of the [2Fe-2S] centers suggest that it could have novel properties compared to other known [2Fe-2S] proteins. We tested the robustness of mitoNEET to mutation and the range over which the redox potential (EM) could be tuned. We found that the protein could tolerate an array of mutations that modified the EM of the [2Fe-2S] center over a range of ∼700 mV, which is the largest EM range engineered in an FeS protein and, importantly, spans the cellular redox range (+200 to-300 mV). These properties make mitoNEET potentially useful for both physiological studies and industrial applications as a stable, water-soluble, redox agent