Local variation in endoparasite intensities of bank voles (Clethrionomys glareolus )from ecologically similar sites: morphometric and endocrine correlates

Much interest has centred recently on the role of adaptive trade-offs between the immune system and other components of life history in determining resistance and parasite intensities among hosts. Steroid hormones, particularly glucocorticoids and sex steroids, provide a plausible mechanism for mediating such trade-offs. A basic assumption behind the hypothesis, however, is that steroid activity will generally correlate with reduced resistance and thus greater parasite intensities. Here, we present some findings from a field study of bank voles (Clethrionomys glareolus ) in which we have looked at associations between parasite intensities, anatomical and morphometric measures relating to endocrine function and life history variation in three local populations inhabiting similar but mutually isolated woodland habitats. In general, sites with greater parasite intensities were those in which male C. glareolus had significantly larger adrenal glands, testes and seminal vesicles for their age and body size. Females also showed a site difference in adrenal gland weight. Some aspects of site-related parasite intensity were associated with asymmetry in adrenal gland weight and hind foot length, which may have reflected developmental effects on glucocorticoid activity

Variation in the helminth community structure in bank voles (Clethrionomys glareolus) from three comparable localities in the Mazury Lake District region of Poland

We tested the null hypothesis that populations of hosts trapped in isolated neighbouring locations showing comparable habitat quality, should support similar helminth parasite communities. The study was undertaken in a 2-week period in late summer in NE Poland in a single year, thereby eliminating seasonal and between-year variation in parasite burdens. A total of 139 Clethrionomys glareolus (bank vole) were sampled from 3 forest sites of similar habitat quality. Total species richness was 11 (6 nematodes and 5 cestodes) with 85±6% of the voles carrying at least 1 species and an overall mean species richness of 1±4. At the component community level, the fewest species of helminths were recorded from site 2 (n=6, compared with 9 at each of the other sites), but site 3 had the lowest Berger-Parker Dominance Index and the highest Simpson's Index of Diversity. At the infracommunity level, site 3 had the highest mean no. of helminthspecies}vole, the highest mean Brillouin's Index of Diversity but the lowest mean no. of helminths/vole. Voles from sites 1 and 3 differed in the nematodes that were most common (site 1, Heligmosomum mixtum ± 95%; site 3, Heligmosomoides glareoli ± 79±3%). At site 2 no species exceeded 50% but prevalence of Syphacia petrusewiczi was higher than at the other sites. The prevalence of cestodes was too low to test reliably (12±9%), but the highest prevalence of adult cestodes was recorded at site 1 (22±5%compared with 4±9 and 1±7%for sites 2 and 3 respectively). Host sex did not ifluence infection, but mean species richness increased with age. The different sites were responsible for most of the variation in our data, and the intrinsic factors (sex and age) were less important in shaping the component community structure of helminths. We conclude that even locations in relative close proximity to one another (13±25 km), selected on the basis of similar habitat quality, have rodent populations that differ in their helminth parasite communities, although for reasons other than the factors quantified in the present study

Human Nail Plate Modifications Induced by Onychomycosis : Implications for Topical Therapy

Open Access - This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedConclusions: Onchomycotic nails presented a thicker but more porous barrier, and its eroded intracellular matrix rendered the tissue more permeable to topically applied chemicals when an aqueous vehicle was used.Purpose: Through the characterisation of the human onchomycotic nail plate this study aimed to inform the design of new topical ungual formulations.Methods: The mechanical properties of the human nail were characterised using a Lloyd tensile strength tester. The nail’s density was determined via pycnometry and the nail’s ultrastructure by electron microscopy. Raman spectroscopy analysed the keratin disulphide bonds within the nail and its permeability properties were assessed by quantifying water and rhodamine uptake.Results: Chronic in vivo nail plate infection increased human nailplate thickness (healthy 0.49 ± 0.15 mm; diseased 1.20 ± 0.67 mm), but reduced its tensile strength (healthy 63.7 ± 13.4 MPa; diseased 41.7 ± 5.0 MPa) and density (healthy 1.34 ± 0.01 g/cm3; diseased 1.29 ± 0.00 g/cm3). Onchomycosis caused cell-cell separation, without disrupting the nail disulfide bonds or desmosomes. The diseased and healthy nails showed equivalent water uptake profiles, but the rhodamine penetration was 4-fold higher in the diseased nails using a PBS vehicle and 3 -fold higher in an ethanol/PBS vehicle.Peer reviewe

Revelations About Carotid Body Function Through its Pathological Role in Resistant Hypertension

Much recent attention has been given to the carotid body because of its potential role in cardiovascular disease states. One disease, neurogenic hypertension, characterised by excessive sympathetic activity, appears dependent on carotid body activity that may or may not be accompanied by sleep-disordered breathing. Herein, we review recent literature suggesting that the carotid body acquires tonicity in hypertension. We predict that carotid glomectomy will be a powerful way to temper excessive sympathetic discharge in diseases such as hypertension. We propose a model to explain that signalling from the ‘hypertensive’ carotid body is tonic, and hypothesise that there will be a sub-population of glomus cells that channel separately into reflex pathways controlling sympathetic motor outflows

Enzootyczne zrodla nowych infekcji przenoszonych przez kleszcze Ixodes ricinus

In the last decade new tick-transmitted zoonoses have emerged as threats to the public health in Europe. They are mostly due to infection by Borrelia burgdorferi s.I., Babesia divergens, B. microti and Ehrlichia sp. All these pathogens are transmitted by the rodent-feeding ticks of Ixodes persulcatus „complex". Also there is first serological information of coexistence of antibodies to B. burgdorferi, B. microti and Ehrlichia sp. in human exposured to these multiple tick-transmitted pathogens. Actually in Poland, the identification of the host species that act as zoonotical reservoir for these pathogens on which the competent vector becomes infected, is crucial to understand the dynamics of enzootie cycle of these pathogens. It is also important to assess the risk factor of infection in different habitats, especially in environmental condition where changing in farming system has left great land area under grassland or pasture, e.g. in Mazury Lakes District Under such circumstances, susceptible rodent species, at least for two of these pathogens: B. micrnti and B. burgdorferi s.l., increasingly became competent reservoirs. This aspect is currently receiving considerable attention in Europe