Micro-CT visualization of a promastigote secretory gel (PSG) and parasite plug in the digestive tract of the sand fly Lutzomyia longipalpis infected with Leishmania mexicana

Leishmaniasis is a debilitating disease of the tropics, subtropics and southern Europe caused by Leishmania parasites that are transmitted during blood feeding by phlebotomine sand flies (Diptera: Psychodidae). Using non-invasive micro-computed tomography, we were able to visualize the impact of the laboratory model infection of Lutzomyia longipalpis with Leishmania mexicana and its response to a second blood meal. For the first time we were able to show in 3D the plug of promastigote secretory gel (PSG) and parasites in the distended midgut of whole infected sand flies and measure its volume in relation to that of the midgut. We were also able to measure the degree of opening of the stomodeal valve and demonstrate the extension of the PSG and parasites into the pharynx. Although our pilot study could only examine a few flies, it supports the hypothesis that a second, noninfected, blood meal enhances parasite transmission as we showed that the thoracic PSGparasite plug in infected flies after a second blood meal was, on average, more than twice the volume of the plug in infected flies that did not have a second blood meal

Emerging Infectious Disease leads to Rapid Population Decline of Common British Birds

Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period

Improved Survival in a Long-Term Rat Model of Sepsis Is Associated With Reduced Mitochondrial Calcium Uptake Despite Increased Energetic Demand

To investigate the relationship between prognosis, changes in mitochondrial calcium uptake, and bioenergetic status in the heart during sepsis

Predicting Response to Radioimmunotherapy from the Tumor Microenvironment of Colorectal Carcinomas

Solid tumors have a heterogeneous pathophysiology, which directly affects antibody-targeted therapies. Here, we consider the influence of selected tumor parameters on radioimmunotherapy, by comparing the gross biodistribution, microdistribution, and therapeutic efficacy of either radiolabeled or fluorescently labeled antibodies (A5B7 anti-carcinoembryonic antigen antibody and a nonspecific control) after i.v. injection in two contrasting human colorectal xenografts in MF1 nude mice. The LS174T is moderately/poorly differentiated, whereas SW1222 has a well-differentiated glandular structure. Biodistribution studies (1.8 MBq (131) I-labeled A5B7, four mice per group) showed similar gross tumor uptake at 48 It in the two models (25.1% and 24.0% injected dose per gram, respectively). However, in therapy studies (six mice per group), LS174T required a 3-fold increase in dose (18 versus 6 MBq) to equal SW1222 growth inhibition (similar to 55 versus similar to 60 days, respectively). To investigate the basis of this discrepancy, high-resolution multifluorescence microscopy was used to study antibody localization in relation to tumor parameters (5 min, I and 24 h, four mice per time point). Three-dimensional microvascular corrosion casting and transmission electron microscopy showed further structural differences between xenografts. Vascular supply, overall antigen distribution, and tumor structure varied greatly between models, and were principally responsible for major differences in antibody localization and subsequent therapeutic efficacy. The study shows that multiparameter, high-resolution imaging of both therapeutic and tumor microenvironment is required to comprehend complex antibody-tumor interactions, and to determine which tumor regions are being successfully treated. This will inform the design of optimized clinical trials of single and combined agents, and aid individual patient selection for antibody-targeted therapies

Field entomology data from Ethiopian trachoma population survey and laboratory transmission experiments for Musca sorbens and Chlamydia trachomatis

A population-based survey of 247 households was conducted in Shashemane district, Oromia Region, Ethiopia, between April and June 2018. Households were positively selected to include at least one child aged 1–9 years, resident on the day of enumeration. These datasets contain entomology from this survey; including fly-eye contact data, fly positivity for Chlamydia trachomatis and other entomological data (fly species, sex). Experiments were also conducted in the London School of Hygiene & Tropical Medicine to investigate transmission of Chlamydia trachomatis by Musca sorbens, those data are reported here

Seasonal incidence of opportunistic reports in all garden bird mortality 2001–2006.

<p>Hatched bars – winter (Dec-Feb), open bars – spring (March–May), stippled bars – summer (June–Aug) and black bars - autumn (Sept-Nov). Note break in axis indicating an unprecedented level of reporting in autumn 2006.</p

Distribution of finch trichomonosis incidents in 2006.

<p>Gardens reporting at least one incident of finch trichomonosis (large red dots) and all other sites (small yellow dots) contributing to the systematic survey. The shading indicates relative incidence of trichomonosis recorded by the opportunistic survey (incidents per thousand households for each county interpolated from county centroids). The heavy lines delineate areas of High, Intermediate and Low incidence, based on the opportunistic survey data.</p

Regional change in greenfinch occurrence in gardens in response to trichomonosis.

<p>Mean reporting rate from GBW of greenfinch, chaffinch and dunnock in spring 2005/06 (filled bars) and 2007 (open bars) in areas of Low, Intermediate and High incidence of trichomonosis incidence (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0012215#pone-0012215-g003" target="_blank">Fig. 3</a>). Bars represent 95% confidence limits.</p

Seasonal variation in greenfinch occurrence in gardens.

<p>(a) Reporting rate for greenfinch in all GBW gardens for the years 1996–2005 (grey lines), 2006 (red) and 2007 (blue). (b) Fitted seasonal pattern of mean peak greenfinch count in 828 GBW gardens with complete counts in 2005. (c) Difference in mean peak count throughout the year between 2005 and 2006 for greenfinch, dashed lines represent 95% confidence limits.</p