Revisiting the Immune Trypanolysis Test to Optimise Epidemiological Surveillance and Control of Sleeping Sickness in West Africa

Human African trypanosomiasis (HAT) due to Trypanosoma brucei (T.b.) gambiense is usually diagnosed using two sequential steps: first the card agglutination test for trypanosomiasis (CATT) used for serological screening, followed by parasitological methods to confirm the disease. Currently, CATT will continue to be used as a test for mass screening because of its simplicity and high sensitivity; however, its performance as a tool of surveillance in areas where prevalence is low is poor because of its limited specificity. Hence in the context of HAT elimination, there is a crucial need for a better marker of contact with T.b. gambiense in humans. We evaluated here an existing highly specific serological tool, the trypanolysis test (TL). We evaluated TL in active, latent and historical HAT foci in Guinea, Côte d'Ivoire and Burkina Faso. We found that TL was a marker for exposure to T.b. gambiense. We propose that TL should be used as a surveillance tool to monitor HAT elimination

Predation Danger Can Explain Changes in Timing of Migration: The Case of the Barnacle Goose

Understanding stopover decisions of long-distance migratory birds is crucial for conservation and management of these species along their migratory flyway. Recently, an increasing number of Barnacle geese breeding in the Russian Arctic have delayed their departure from their wintering site in the Netherlands by approximately one month and have reduced their staging duration at stopover sites in the Baltic accordingly. Consequently, this extended stay increases agricultural damage in the Netherlands. Using a dynamic state variable approach we explored three hypotheses about the underlying causes of these changes in migratory behavior, possibly related to changes in (i) onset of spring, (ii) potential intake rates and (iii) predation danger at wintering and stopover sites. Our simulations showed that the observed advance in onset of spring contradicts the observed delay of departure, whereas both increased predation danger and decreased intake rates in the Baltic can explain the delay. Decreased intake rates are expected as a result of increased competition for food in the growing Barnacle goose population. However, the effect of predation danger in the model was particularly strong, and we hypothesize that Barnacle geese avoid Baltic stopover sites as a response to the rapidly increasing number of avian predators in the area. Therefore, danger should be considered as an important factor influencing Barnacle goose migratory behavior, and receive more attention in empirical studies

The association of serum lipids with the histological pattern of rectosigmoid adenoma in Taiwanese adults

<p>Abstract</p> <p>Background</p> <p>The mortality rate of colorectal cancer ranks third behind lung and hepatic cancer in Taiwan. Colorectal cancer mostly arises from adenomatous polyps of left colon. The aim of our study was to examine the association of serum lipids with the histological pattern of rectosigmoid adenoma.</p> <p>Methods</p> <p>There were 2,506 eligible examinees aged 20 and above who underwent sigmoidoscopy as a screening examination in National Cheng Kung University Hospital between January 2003 and October 2006. They were classified into three groups: tubular adenoma (333 subjects), villous-rich (tubulovillous/villous) adenoma (53 subjects) and normal (2,120 subjects). We defined high total cholesterol (TC) as a level ≧200 mg/dl, low high-density lipoprotein cholesterol (HDL-C) as a level <40 mg/dL, and high triglyceride (TG) as a level ≧200 mg/dl according to the third report of the National Cholesterol Education Program expert panel on detection, evaluation, and treatment of high blood cholesterol in adults. Adenoma histology was classified as tubular, tubulovillous and villous according to the proportion of villous part.</p> <p>Results</p> <p>Among the study population, 333 subjects (13.3%) had tubular adenomas and 53 subjects (2.1%) had villous-rich adenomas. The odds ratio (OR) for villous-rich adenoma in subjects with TG≧200 mg/dL compared to those with TG < 200 mg/dL was 3.20 (95% confidence interval [CI]:1.71-6.01), after adjusting for age, gender, general obesity, central obesity, diabetes, hypertension, smoking, and alcohol consumption. If further taking high TC and low HDL-C into consideration, the OR was 4.42 (95% CI:2.03-9.63).</p> <p>Conclusions</p> <p>Our study showed that subjects with high serum TG tended to have a higher risk of tubulovillous/villous adenoma in rectosigmoid colon. Therefore, reducing the serum TG level might be one method to prevent the incidence of colorectal cancer.</p

Detection of small RNAs in Bordetella pertussis and identification of a novel repeated genetic element

Background: Small bacterial RNAs (sRNAs) have been shown to participate in the regulation of gene expression and have been identified in numerous prokaryotic species. Some of them are involved in the regulation of virulence in pathogenic bacteria. So far, little is known about sRNAs in Bordetella, and only very few sRNAs have been identified in the genome of Bordetella pertussis, the causative agent of whooping cough. Results: An in silico approach was used to predict sRNAs genes in intergenic regions of the B. pertussis genome. The genome sequences of B. pertussis, Bordetella parapertussis, Bordetella bronchiseptica and Bordetella avium were compared using a Blast, and significant hits were analyzed using RNAz. Twenty-three candidate regions were obtained, including regions encoding the already documented 6S RNA, and the GCVT and FMN riboswitches. The existence of sRNAs was verified by Northern blot analyses, and transcripts were detected for 13 out of the 20 additional candidates. These new sRNAs were named Bordetella pertussis RNAs, bpr. The expression of 4 of them differed between the early, exponential and late growth phases, and one of them, bprJ2, was found to be under the control of BvgA/BvgS two-component regulatory system of Bordetella virulence. A phylogenetic study of the bprJ sequence revealed a novel, so far undocumented repeat of ~90 bp, found in numerous copies in the Bordetella genomes and in that of other Betaproteobacteria. This repeat exhibits certain features of mobil

Mainstreams of Horizontal Gene Exchange in Enterobacteria: Consideration of the Outbreak of Enterohemorrhagic E. coli O104:H4 in Germany in 2011

Escherichia coli O104:H4 caused a severe outbreak in Europe in 2011. The strain TY-2482 sequenced from this outbreak allowed the discovery of its closest relatives but failed to resolve ways in which it originated and evolved. On account of the previous statement, may we expect similar upcoming outbreaks to occur recurrently or spontaneously in the future? The inability to answer these questions shows limitations of the current comparative and evolutionary genomics methods.status: publishe

Micro-connectomics: probing the organization of neuronal networks at the cellular scale.

Defining the organizational principles of neuronal networks at the cellular scale, or micro-connectomics, is a key challenge of modern neuroscience. In this Review, we focus on graph theoretical parameters of micro-connectome topology, often informed by economical principles that conceptually originated with Ramón y Cajal's conservation laws. First, we summarize results from studies in intact small organisms and in samples from larger nervous systems. We then evaluate the evidence for an economical trade-off between biological cost and functional value in the organization of neuronal networks. Various results suggest that many aspects of neuronal network organization are indeed the outcome of competition between these two fundamental selection pressures.This work was supported by the National Institute of Health Research (NIHR) Cambridge Biomedical Research Centre.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by the Nature Publishing Group