Integrated-baiting concept against Echinococcus multilocularis in foxes is successful in southern Bavaria, Germany

This paper describes the design and the preliminary evaluation of an integrated approach to the control of Echinococcus multilocularis in foxes using praziquantel bait. Air distribution of bait in agricultural and recreational areas was combined with distribution of bait by hand in towns and villages to cover the entire fox population in the 213-km² baiting area. Bait distribution density was 50/km², and bait was distributed once every 4 weeks. Pre-baiting prevalence was 35% (22–50% CI 95%). During a 1-year period following the first 4 months of bait distribution, only one positive fox was found (prevalence 1%; 0–4% CI 95%). No significant change had occurred in the unbaited control area. This prevalence decline is far more pronounced than in previous fox-baiting studies, which is likely to be due to the increased bait distribution density and baiting frequency, and the inclusion of the ‘urban’ fox population.     

The PagN protein of <Emphasis Type="Italic">Salmonella enterica</Emphasis> serovar Typhimurium is an adhesin and invasin

Background  

The pagN gene of Salmonella enterica serovar Typhimurium is a PhoP-regulated gene that is up-regulated during growth within macrophages and in vivo in murine models of infection. The PagN protein displays similarity to the Hek and Tia invasins/adhesins of Escherichia coli. Thus far no function has been ascribed to the PagN protein.     

Dimerization of Receptor Protein-Tyrosine Phosphatase alpha in living cells

Background  

Dimerization is an important regulatory mechanism of single membrane-spanning receptors. For instance, activation of receptor protein-tyrosine kinases (RPTKs) involves dimerization. Structural, functional and biochemical studies suggested that the enzymatic counterparts of RPTKs, the receptor protein-tyrosine phosphatases (RPTPs), are inhibited by dimerization, but whether RPTPs actually dimerize in living cells remained to be determined.     

The Spread of Multi Drug Resistant Infections Is Leading to an Increase in the Empirical Antibiotic Treatment Failure in Cirrhosis: A Prospective Survey

BackgroundThe spread of multi-resistant infections represents a continuously growing problem in cirrhosis, particularly in patients in contact with the healthcare environment.AimOur prospective study aimed to analyze epidemiology, prevalence and risk factors of multi-resistant infections, as well as the rate of failure of empirical antibiotic therapy in cirrhotic patients.MethodsAll consecutive cirrhotic patients hospitalized between 2008 and 2013 with a microbiologically-documented infection (MDI) were enrolled. Infections were classified as Community-Acquired (CA), Hospital-Acquired (HA) and Healthcare-Associated (HCA). Bacteria were classified as Multidrug-Resistant (MDR) if resistant to at least three antimicrobial classes, Extensively-Drug-Resistant (XDR) if only sensitive to one/two classes and Pandrug-Resistant (PDR) if resistant to all classes.ResultsOne-hundred-twenty-four infections (15% CA, 52% HA, 33% HCA) were observed in 111 patients. Urinary tract infections, pneumonia and spontaneous bacterial peritonitis were the more frequent. Forty-seven percent of infections were caused by Gram-negative bacteria. Fifty-one percent of the isolates were multi-resistant to antibiotic therapy (76% MDR, 21% XDR, 3% PDR): the use of antibiotic prophylaxis (OR = 8.4; 95%CI = 1.03-76; P = 0,05) and current/recent contact with the healthcare-system (OR = 3.7; 95%CI = 1.05-13; P = 0.04) were selected as independent predictors. The failure of the empirical antibiotic therapy was progressively more frequent according to the degree of resistance. The therapy was inappropriate in the majority of HA and HCA infections.ConclusionsMulti-resistant infections are increasing in hospitalized cirrhotic patients. A better knowledge of the epidemiological characteristics is important to improve the efficacy of empirical antibiotic therapy. The use of preventive measures aimed at reducing the spread of multi-resistant bacteria is also essential.     

The laminin β1-competing peptide YIGSR induces a hypercontractile,hypoproliferative airway smooth muscle phenotype in an animal model of allergic asthma

Background

Fibroproliferative airway remodelling, including increased airway smooth muscle (ASM) mass and contractility, contributes to airway hyperresponsiveness in asthma. In vitro studies have shown that maturation of ASM cells to a (hyper)contractile phenotype is dependent on laminin, which can be inhibited by the laminin-competing peptide Tyr-Ile-Gly-Ser-Arg (YIGSR). The role of laminins in ASM remodelling in chronic asthma in vivo, however, has not yet been established.

Methods

Using an established guinea pig model of allergic asthma, we investigated the effects of topical treatment of the airways with YIGSR on features of airway remodelling induced by repeated allergen challenge, including ASM hyperplasia and hypercontractility, inflammation and fibrosis. Human ASM cells were used to investigate the direct effects of YIGSR on ASM proliferation in vitro.

Results

Topical administration of YIGSR attenuated allergen-induced ASM hyperplasia and pulmonary expression of the proliferative marker proliferating cell nuclear antigen (PCNA). Treatment with YIGSR also increased both the expression of sm-MHC and ASM contractility in saline- and allergen-challenged animals; this suggests that treatment with the laminin-competing peptide YIGSR mimics rather than inhibits laminin function in vivo. In addition, treatment with YIGSR increased allergen-induced fibrosis and submucosal eosinophilia. Immobilized YIGSR concentration-dependently reduced PDGF-induced proliferation of cultured ASM to a similar extent as laminin-coated culture plates. Notably, the effects of both immobilized YIGSR and laminin were antagonized by soluble YIGSR.

Conclusion

These results indicate that the laminin-competing peptide YIGSR promotes a contractile, hypoproliferative ASM phenotype in vivo, an effect that appears to be linked to the microenvironment in which the cells are exposed to the peptide.     

Simultaneous determination of fluvoxamine isomers and quetiapine in human plasma by means of high-performance liquid chromatography

An original HPLC-UV method has been developed for the simultaneous determination of the atypical antipsychotic quetiapine and the geometric isomers of the second-generation antidepressant fluvoxamine. The analytes were separated on a reversed-phase C8 column (150 mm x 4.6mm i.d., 5 microm) using a mobile phase composed of acetonitrile (30%) and a 10.5mM, pH 3.5 phosphate buffer containing 0.12% triethylamine (70%). The flow rate was 1.2 mL min(-1) and the detection wavelength was 245 nm. Sample pretreatment was carried out by an original solid-phase extraction procedure using mixed-mode cation exchange (DSC-MCAX) cartridges; only 300 microL of plasma were needed for one analysis. Citalopram was used as the internal standard. The method was validated in terms of linearity, extraction yield, precision and accuracy. Good linearity was obtained in plasma over the 5.0-160.0 ng mL(-1) concentration range for each fluvoxamine isomer and over the 2.5-400.0 ng mL(-1) concentration range for quetiapine. Extraction yield values were always higher than 93%, with precision (expressed as relative standard deviation values) better than 4.0%. The method was successfully applied to human plasma samples drawn from patients undergoing polypharmacy with the two drugs. Satisfactory accuracy values were obtained, with mean recovery higher than 94%.     

Establishing Functional Relationships between Abiotic Environment,Macrophyte Coverage,Resource Gradients and the Distribution of Mytilus trossulus in a Brackish Non-Tidal Environment

Benthic suspension feeding mussels are an important functional guild in coastal and estuarine ecosystems. To date we lack information on how various environmental gradients and biotic interactions separately and interactively shape the distribution patterns of mussels in non-tidal environments. Opposing to tidal environments, mussels inhabit solely subtidal zone in non-tidal waterbodies and, thereby, driving factors for mussel populations are expected to differ from the tidal areas. In the present study, we used the boosted regression tree modelling (BRT), an ensemble method for statistical techniques and machine learning, in order to explain the distribution and biomass of the suspension feeding mussel Mytilus trossulus in the non-tidal Baltic Sea. BRT models suggested that (1) distribution patterns of M. trossulus are largely driven by separate effects of direct environmental gradients and partly by interactive effects of resource gradients with direct environmental gradients. (2) Within its suitable habitat range, however, resource gradients had an important role in shaping the biomass distribution of M. trossulus. (3) Contrary to tidal areas, mussels were not competitively superior over macrophytes with patterns indicating either facilitative interactions between mussels and macrophytes or co-variance due to common stressor. To conclude, direct environmental gradients seem to define the distribution pattern of M. trossulus, and within the favourable distribution range, resource gradients in interaction with direct environmental gradients are expected to set the biomass level of mussels.     

Advantages of larval control for African malaria vectors: Low mobility and behavioural responsiveness of immature mosquito stages allow high effective coverage

Background  

Based on sensitivity analysis of the MacDonald-Ross model, it has long been argued that the best way to reduce malaria transmission is to target adult female mosquitoes with insecticides that can reduce the longevity and human-feeding frequency of vectors. However, these analyses have ignored a fundamental biological difference between mosquito adults and the immature stages that precede them: adults are highly mobile flying insects that can readily detect and avoid many intervention measures whereas mosquito eggs, larvae and pupae are confined within relatively small aquatic habitats and cannot readily escape control measures.