Rift Valley fever virus detection in susceptible hosts with special emphasis in insects.

Rift Valley fever phlebovirus (RVFV, Phenuiviridae) is an emerging arbovirus that can cause potentially fatal disease in many host species including ruminants and humans. Thus, tools to detect this pathogen within tissue samples from routine diagnostic investigations or for research purposes are of major interest. This study compares the immunohistological usefulness of several mono- and polyclonal antibodies against RVFV epitopes in tissue samples derived from natural hosts of epidemiologic importance (sheep), potentially virus transmitting insect species (Culex quinquefasciatus, Aedes aegypti) as well as scientific infection models (mouse, Drosophila melanogaster, C6/36 cell pellet). While the nucleoprotein was the epitope most prominently detected in mammal and mosquito tissue samples, fruit fly tissues showed expression of glycoproteins only. Antibodies against non-structural proteins exhibited single cell reactions in salivary glands of mosquitoes and the C6/36 cell pellet. However, as single antibodies exhibited a cross reactivity of varying degree in non-infected specimens, a careful interpretation of positive reactions and consideration of adequate controls remains of critical importance. The results suggest that primary antibodies directed against viral nucleoproteins and glycoproteins can facilitate RVFV detection in mammals and insects, respectively, and therefore will allow RVFV detection for diagnostic and research purposes.

Selecting efficient methodologies for estimation of As and Hg availability in a brownfield.

The determination of soil metal(loid) availability presents controversy and there is no consensus or uniformity on used analytical methods. In this study nine single extraction methods (H2O, CaCl2, NaNO3, NH4NO3, DTPA, EDTA, HCl, LMWOA, TCLP) and four sequential extraction procedures (Tessier, BCR, Wenzel and Fernández-Martínez) have been compared to estimate the availability of As and Hg in two soils from a highly polluted brownfield, especially with As. The metal(loid) concentrations were also determined in three native plant species (Lotus corniculatus, Betula celtiberica and Dactylis glomerata) collected in the habitat under study. Each single extractant showed a particular capacity of As/Hg extraction because they do not extract the same forms of each element. The availability of As and Hg depended on the element characteristics, soil properties, type of extractant and degree of pollution, thus the use of a single extraction procedure provides limited information of metal(loid) availability and to reach general conclusions is difficult. Regarding the sequential extractions, each procedure showed a specific pattern for As and Hg regardless of the soil. Thus, the choice of one or other method depends on the environmental conditions, metal(loid) and soil properties. In risk assessment studies it would be recommendable to select one of the more aggressive extractants, so as not to underestimate the environmental risk. In this regard, the sequential extraction procedures render more detailed information about metal(loid) potential availability in relation to soil properties. The analysis of native plant species showed higher metal(loid) concentrations in roots than in aerial parts and differences were observed depending on the metal(loid) and the species. In general, plants showed a higher BCFs for Hg than As even though the total and available As concentrations were higher than those found for Hg, which highlights the influence of plant species on the metal(loid) uptake.

Geometric morphometric wing analysis represents a robust tool to identify female mosquitoes (Diptera: Culicidae) in Germany.

Accurate species identification is the prerequisite to assess the relevance of mosquito specimens, but is often hindered by missing or damaged morphological features. The present study analyses the applicability of wing geometric morphometrics as a low-cost and practical alternative to identify native mosquitoes in Germany. Wing pictures were collected for 502 female mosquitoes of five genera and 19 species from 80 sampling sites. The reliable species identification based on interspecific wing geometry of 18 landmarks per specimen was tested. Leave-one-out cross validation revealed an overall accuracy of 99% for the genus and 90% for the species identification. Misidentifications were mainly due to three pairings of Aedes species: Aedes annulipes vs. Aedes cantans, Aedes cinereus vs. Aedes rossicus and Aedes communis vs. Aedes punctor. Cytochrome oxidase subunit I (COI) gene region was sequenced to validate the morphological and morphometric identification. Similar to the results of the morphometric analysis, the same problematic three Aedes-pairs clustered, but most other species could be well separated. Overall, our study underpins that morphometric wing analysis is a robust tool for reliable mosquito identification, which reach the accuracy of COI barcoding.

Culex torrentium mosquitoes from Germany are negative for Wolbachia.

Wolbachia (Rickettsiales: Anaplasmataceae) infects a wide range of arthropods, including several mosquito species. The bacterium is known to induce a plethora of phenotypes in its host, examples being the reproductive phenotype cytoplasmic incompatibility or resistance against infection with arboviruses. The latter is especially relevant when assessing the vector competence of mosquito species for emerging arboviruses. Thus, knowledge of Wolbachia infection status is important for the assessment of vector competence. To facilitate Wolbachia screening in mosquito populations, a quantitative polymerase chain reaction (qPCR) assay was developed to enable high-throughput analysis of mosquito samples. Using this assay, the Wolbachia infection status of the two most common Culex mosquito species in Germany, Culex pipiens biotype pipiens Linnaeus (Diptera: Culicidae) and Culex torrentium Martini (Diptera: Culicidae), was assessed. About 93% of all tested C. pipiens biotype pipiens individuals were positive for Wolbachia, whereas none of the C. torrentium samples was found to be infected. Furthermore, other applications of the qPCR assay were explored by assessing a potential link between the levels of Wolbachia and West Nile virus (WNV) infections in German C. pipiens biotype pipiens mosquitoes. No relationship was found between the two variables, indicating that a Wolbachia-induced antiviral phenotype in this mosquito population is not exclusively attributable to the general level of bacterial infection.

Influence of age and gender on complexity measures for short term heart rate variability analysis in healthy subjects.

Short-term heart rate variability (HRV) analyses (less than 30 min) are suitable for ambulatory care and patient monitoring and can provide an almost immediate test result. Short-term 5 min HRV indices from nonlinear dynamics were determined from 782 females and 1124 males from the KORA S4 database. We applied various fractal and complexity measures with focus on entropies and investigated the influence of age in terms of five age decades (25-34, 35-44, 45-54, 55-64 and 65-74 years) and gender on these HRV indices. The analyses revealed significant modifications of the indices especially by age but partly also by gender especially in the younger groups. These results should be considered in future studies applying nonlinear dynamics, especially if major age and gender differences between the investigated groups are expected.

Short-term heart rate variability--age dependence in healthy subjects.

Heart rate variability (HRV) analysis is an established method to characterize the autonomic regulation and is based mostly on 24h Holter recordings. The importance of short-term HRV (less than 30 min) for various applications is growing consistently. Major reasons for this are the suitability for ambulatory care and patient monitoring and the ability to provide an almost immediate test result. So far, there have been only a few studies that provided statistically relevant reference values for short-term HRV. In our study, 5 min short-term HRV indices were determined from 1906 healthy subjects. From these records, linear and nonlinear indices were extracted. To determine general age-related influences, HRV indices were compared from subjects aged 25-49 years with subjects aged 50-74 years. In a second approach, we examined the development of HRV indices by age in terms of age decades (25-34, 35-44, 45-54, 55-64 and 65-74 years). Our results showed significant variations of HRV indices by age in almost all domains. While marked dynamics in terms of parameter change (variability reduction) were observed in the first age decades, in particular the last two age decades showed certain constancy with respect to the HRV indices examined.

[Characteristics of sleep in abstinent alcoholics. A comparison of alcohol- and age-induced reduction of deep sleep]. / Besonderheiten des Schlafes bei abstinenten Alkoholikern Vergleich alkohol- und alterungsbedingter Tiefschlafreduktion.

Polygraphic sleep recordings were performed in 12 sober alcoholic patients, 8 young normals and 12 healthy elderly subjects. An automatic sleep analysis including two different methods (standard and adaptive) of SWS scoring was used. The standard method is based on amplitude dependent rules according to Rechtschaffen and Kales. The basis for classification of SWS in the adaptive method is the relative increase of the integrated delta-activity during NREM sleep. Whereas in young and elderly normal subjects the method used has no influence on the duration of SWS during the night, the amount of SWS in alcoholic patients is significantly higher when applying the adaptive sleep analysis compared with the results of the standard method. Alcoholics show the lowest level of integrated delta activity during NREM and also the shortest duration of SWS resulting from the standard sleep analysis. On the contrary the relative dynamic of EEG synchronization and the duration of SWS measured by the adaptive sleep analysis are comparable with the values of normal subjects. The general decrease of the delta activity during sleep in sober alcoholics is assumed to be not a reflection of the reduction of SWS.

[Automatic sleep analysis--II. Determination of sleep stages]. / Automatische Schlafanalyse--II. Schlafstadienbestimmung.

The presented automatic sleep analysis is based on the time courses of the mean amplitudes of EEG (delta, beta and alpha bands), EMG and motility and specific patterns (spindles, REMs, delta waves greater than 40 microV) detected automatically. The interindividual variability of the parameters is taken into consideration by interactively determining the threshold levels. Sleep stages are classified for every epoch using context free decision rules according to the manual of Rechtschaffen and Kales. The resulting cyclograms are smoothed and corrected using context sensitive rules which considers the successive epochs and the probability of stage transitions.