Long-term changes in abundance of bats as revealed by their frequency in tawny owls’ diet

Percentage of bats in tawny owls’ diet was compared in three periods: I — before 1976, II — 1976–1992, III — 1993–2009, by using the published and unpublished material from Poland (only samples over 100 vertebrate prey items). This species of owl showed an opportunistic predation on bats and took them more frequently in periods of higher abundance. Before the mass use of toxic pesticides in Poland, in the period I bats constituted more than 2% of vertebrates in four out of five diet samples (median 2.4%). The lowest bat abundance occurred in Poland in the 1980s and resulted in the lowest percentage of bats taken by owls in the period II (n = 11, median 0.2%). Due to the recovery of bat populations in the period III, the percentage of bats in tawny owls’ diet increased (n = 23, median 0.7%). In large samples (over 200 vertebrate items, n = 21) collected in central and north-eastern Poland the percentage of bats increased from 1980 to 2009 (the estimated average value at the end of that period slightly exceeded 1%). Samples collected at the same five sites in 1975–1992 and again in 2000–2009, confirmed the increasing trend in percentage of bats captured by tawny owls noted in last years.     

Real time PCR hybridization for the rapid and specific identification of Francisella tularensis

Tularemia is highly infectious and fatal zoonotic disease caused by Gram negative bacteria Francisella tularensis. The necessity to undergo medical treatment in early phase of illness in humans and possibility of making use of bacterial aerosol by terrorists in an attack create an urgent need to implement a rapid and effective method which enables to identify the agent. In our study two primers FopA F/R and hybridization probes FopA S1/S2 designed from fopA gene sequence, were tested for their potential applicability to identify F. tularensis. In this research 50 strains of F. tularensis were used and the test gave positive results. Reaction specificity was confirmed by using of non-Francisella tularensis bacterial species. The results obtained in the real-time PCR reaction with primers Tul4 F/R and hybridization probes Tul4 S1/S2, designed from tul4 gene, were comparable to the results from previous experiment with fopA - primers set. Investigation of fopA and tul4 primers and hybridization probes properties revealed characteristic Tm (melting temperature) value of the products--61 degrees C and 60 degrees C, respectively. Detection sensitivity was remarkably higher when fopA primers set was used 1 fg/microl, and for tul4 primers set, minimal detectable concentration is 10 fg/microl.     

Peristalsis in the junction region of the <Emphasis Type="Italic">Drosophila</Emphasis> larval midgut is modulated by DH31 expressing enteroendocrine cells

Background  

The underlying cellular and molecular mechanisms that coordinate the physiological processes in digestion are complex, cryptic, and involve the integration of multiple cellular and organ systems. In all intestines, peristaltic action of the gut moves food through the various stages of digestion from the anterior end towards the posterior, with the rate of flow dependent on signals, both intrinsic and extrinsic to the gut itself.     

Effects of MMP-9 inhibition by doxycycline on proteome of lungs in high tidal volume mechanical ventilation-induced acute lung injury

Background  

Although mechanical ventilation (MV) is a major supportive therapy for patients with acute respiratory distress syndrome, it may result in side effects including lung injury. In this study we hypothesize that MMP-9 inhibition by doxycycline might reduce MV-related lung damage. Using a proteomic approach we identified the pulmonary proteins altered in high volume ventilation-induced lung injury (VILI). Forty Wistar rats were randomized to an orally pretreated with doxycycline group (n = 20) or to a placebo group (n = 20) each of which was followed by instrumentation prior to either low or high tidal volume mechanical ventilation. Afterwards, animals were euthanized and lungs were harvested for subsequent analyses.     

Delayed pharmacological effects of proctolin and CCAP on heartbeat in pupae of the tobacco hornworm, Manduca sexta

Abstract. The effects in vivo of cardioactive peptides proctolin, CCAP and leucomyosuppressin (LMS) are investigated by means of noninvasive optocardiographic or thermographic techniques in postdiapause pupae of Manduca sexta. A constant pattern of heartbeat reversal in these pupae is manifested by regular alternations of the forward orientated (anterograde) and the backward orientated (retrograde) cardiac pulsations, with a periodicity of some 5–10 min. The heartbeat pattern is monitored continuously for several hours before and 24 h after injection of the investigated peptides. Injections of Ringer solution alone cause a slight, almost immediate increase of the rate of the pupal heartbeat (0–10%), which lasts only for 20–30 min. Injection of proctolin, CCAP or LMS does not show any immediate cardiostimulating effects (beyond those of Ringer) at concentrations up to 2 × 10⁻⁶ M (calculated from µg of the injected peptide and 70% pupal water content; 5–7 g pupal body mass). By contrast, injections of proctolin and CCAP in the range of 10^-9 − 10^-6 M concentrations cause delayed effects on the heartbeat, which are manifested only several hours after the injections. The delayed effects involve prolonged, or even continuous periods of unidirectional, more efficient and faster anterograde pulsations. Consequently, the flow of haemolymph through the head and thoracic parts of the pupal body increases. In the case of proctolin, the prolonged anterograde cardiac activity usually starts 5 h after the injections and the effect persists for 7–12 h. Using CCAP, the stimulation of anterograde activity starts 2.5–3 h after injections and lasts usually 7–8 h. Very small doses of peptides (10^-8 − 10^-9 M) do not change the latency period significantly, but they decrease the duration of the response. The frequency of the systolic contractions of the heart does not increase during the prolonged anterograde phase. Injections of LMS to produce a final concentration of 10⁻⁶ M in the pupa induce pathophysiological disturbances of heartbeat reversal and peristalsis. The effects start with a delay of some 1.5–2.5 h after the injections. By contrast to the effects of proctolin and CCAP, LMS does not produce delayed anterograde cardiac pulsations. These results show that the most intensively investigated cardiostimulating peptides in vitro, proctolin and CCAP, have no direct cardiostimulating activity under physiological conditions in vivo. It is concluded therefore that the delayed pharmacological effects of these peptides observed in the pupae of M. sexta, represent a secondary effect, resulting from stimulation of nonspecific, extracardiac myotropic or other physiological functions.     

Flavonoid profiling among wild type and related GM wheat varieties

Pleiotropic effects are one of the main concerns regarding genetically modified organisms (GMOs). This includes unintended side effects of the transgene or its genome insertion site on the regulation of other endogenous genes, which could potentially cause the accumulation of different secondary metabolites that may have not only an impact on diet as repeatedly worried by the public but also on the environment. Regarding amount and possible environmental effects, flavonoids represent the most prominent group of secondary metabolites in wheat. Many flavonoids function as signalling or defence molecules. We used a robust and reproducible analytical method to compare the flavonoid content of genetically modified (GM) wheat (Triticum aestivum L., Gramineae) expressing genes that confer increased fungal resistance with their non-GM siblings. The transgenes provide either a broad-spectrum fungal defence (chitinase/glucanase from barley) or bunt-specific resistance by a viral gene (KP4). Significant differences in flavonoid composition were found between different wheat varieties whereas different lines of GM wheat with increased antifungal resistance showed only minor differences in their flavonoid composition relative to their non-GM siblings. In a field test, no significant differences were detectable between infected and non-infected wheat of the same variety regardless of the presence of the transgene. Our results are in agreement with the hypothesis that the transgenes we used to increase wheat defence to fungal pathogens do not interfere with the flavonoid biosynthesis pathway. More significantly, the genetic background resulting from conventional breeding has a direct impact on the biological composition of flavonoids, and thus possibly on the environment.     

Development of a new real-time TaqMan PCR assay for quantitative analyses of Candida albicans resistance genes expression

Candida albicans is an important opportunistic pathogen that can cause serious fungal diseases in immunocompromised patients including cancer patients, transplant patients, and patients receiving immunosuppressive therapy in general, those with human immunodeficiency virus infections and undergoing major surgery. Its emergence spectrum varies from mucosal to systemic infections and the first line treatment is still based on fluconazole, a triazole derivate with a potent antifungal activity against most of C. albicans strains. Nevertheless the emergence of fluconazole-resistant C. albicans strains can lead to treatment failures and thus become a clinical problem in the management of such infections. For that reason we consider it important to study mechanisms inducing azole resistance and the possibilities to influence this process. In this work we give a short report on a real-time PCR (TaqMan) assay, which can be used for quantitative analyses of gene expression levels of MDR1, CDR1 and ERG11, genes supposed to contribute to development of the resistance mechanisms. We show some results achieved with that assay in fluconazole susceptible and resistant strains that confirm results seen earlier in experiments using Northern blot hybridisation and prove that the comparative DeltaCt method is valid for our system.     

Immunomarking reveals food flow and feeding relationships in the eastern subterranean termite, Reticulitermes flavipes (Kollar)

Trophallaxis and feeding relationships in the eastern subterranean termite, Reticulitermes flavipes (Kollar), were examined using a novel marking technique, rabbit IgG protein coupled with an enzyme linked immunosorbent assay (ELISA) to detect the marker. Transfer experiments in small dishes evaluated the trophallactic transfer of the marker from donor workers fed IgG-treated paper to recipient workers or larvae. Worker donors rapidly acquired the marker, and 100% of donors tested positive within 24 h. Trophallactic transfer from donors to recipients was relatively inefficient, and 51 +/- 2% of recipient workers and 31 +/- 2% of recipient larvae tested positive at 72 h. Based on the mean optical density counts, approximately 27% of marker ingested by the donors was passed on to the recipient workers in the first 24 h, 14% to recipient larvae, and 26% to recipient soldiers. The ability of soldiers to feed independently of workers was examined in dish assays. Soldiers showed no significant uptake of the marker when isolated from the workers, and uptake increased significantly when workers were present. The distribution of the marker was further studied in larger colony fragments composed of workers, soldiers, nymphs, and larvae. Marker acquisition by the different castes/developmental stages was highly variable, with workers and nymphs acquiring the marker at a faster rate than soldiers and larvae. The results of this study contribute to our understanding of the foraging ecology and social behavior in R. flavipes. In addition, they may help design improved control programs for subterranean termites based on baits.