Demodicosis in nine prairie dogs (Cynomys ludovicianus)

This case report describes the clinical signs and treatment of demodicosis in nine pet prairie dogs (Cynomys ludovicianus). Clinical records including history, clinical examination, microscopic evaluation and fungal culture of the skin lesions were available for all nine animals. In seven animals, blood was obtained for haematological and biochemical analyses. Clinical signs comprised bilaterally symmetrical alopecia extending from the middle part of the back down to the skin of the thighs and the dorsal and ventral parts of the tail. Demodex mites were found in skin scrapings from all cases. Treatment with amitraz at 250 p.p.m. resulted in resolution of lesions and hair regrowth. This is the first report of demodicosis in this species.     

Abbau von Huminstoffen durch Bodenmikroorganismen — eine Übersicht

Degradation of humic substances by soil microorganisms — a review Humic substances which represent differently extractable fractions of the soil organic matter exert multifarious effects on soil as a site for plant growth and a part of terrestrial environments. Among them especially humic acids and fulvic acids are subject to degradation and/or transformation by soil microorganisms. Several authors demonstrated the participation of different species of fungi, actinomycetes and also of non-mycelial aerobic or anaerobic bacteria in those processes under laboratory conditions. Indications exist that humic substances irrespective of their structure undergo degradation on cell surfaces due to the activity of exoenzymes. In this respect microbial phenoloxidases play an extraordinarily important role. The degradation rate of humic substances can be followed by optical, gravimetric and chemoanalytical methods as well as using biochemical and microbiological procedures (CO₂ release, microbial growth, biomass formation). An objective evaluation, however, can be hindered by the adsorption of humic substances on microbial biomass and sometimes also by formation of novel humic-like microbial metabolites. Therefore it is necessary to apply a multifactorial approach in the study of the degradation of humic substances which includes both quantitative and qualitative parameters. To better elucidate how these processes may occur under natural conditions, mixed populations of soil microorganisms should be predominantly involved in future studies.     

Microbial Utilization and Transformation of Humic Acids Extracted from Different Soils

Humic acids (HA) extracted from Chernozem (Haplic Phaeozem), Brown Earth (Cambic Umbrisol) and Podzol (Humic Podzol) were added as a supplemental source of nutrients, or as the sole sources of carbon and nitrogen to aerobic cultures of complex microbial communities indigenous to the same individual soils. Depending on nutrient conditions in the individual cultures and origin of HA, between 14 and 86 % of the added HA was utilized. The formation of microbial biomass was enhanced up to six fold in the full-strength nutrient media supplemented with humic acids but was strongly inhibited if HA served as the sole C source. HA preparations re-isolated from the microbial cultures exhibited elemental and structural changes characteristic for early diagenetic transformations of humic substances. These included an increase in carbon content, C:N ratio, infra-red absorption typical for aromatics, and a decrease in infra-red absorption associated with aliphatic acids, nitrogenous and carbohydrate-like substances.     

Insect pest management agents: hormonogen esters (juvenogens)

The chemical part of this investigation focused on designing structures and synthesizing a series of six new esters (juvenogens), derived from biologically active insect juvenile hormone bioanalogues (juvenoids, JHAs) and unsaturated short-chain linear and branched fatty acids for possible application as biochemically targeted insect hormonogen agents. The structures of the new compounds were assigned on the basis of a detailed NMR analysis of their (1)H and (13)C NMR spectra. The biological part of this investigation focused on introductory biological screening tests with these compounds against the red firebug (Pyrrhocoris apterus), termites (Reticulitermes santonensis and Prorhinotermes simplex), and the blowfly (Neobellieria bullata). The biological activity of the juvenogens was studied in relation to the fatty acid functionality in the structures. Notable biological activity in topical tests and medium activity in peroral tests was found for the juvenogens 3 and 7 with P. apterus. The compounds 6 and 8 showed the lowest activity in both topical and oral assays with P. apterus. Considerable effect of all tested juvenogens was observed in P. simplex; however, the juvenogens 5 and 6 (derivatives of the only branched short-chain fatty acid) showed no activity against R. santonensis. The effect of the compounds 3-8 on larval hatching of N. bullata was only moderate (larval hatching 80-90%); however, the proliferation effect caused by 5, 6, and 8 is more pronounced than the effect caused by 3, 4, and 7.     

Detection of Anaplasma dna in Ixodes ricinus ticks: pitfalls

A total of 150 nymphal Ixodes ricinus (L., 1758) (Acari: Ixodidae) from the Czech Republic were examined for Anaplasma phagocytophilum (Foggie, 1949) Dumler et al., 2001 by PCR using EHR521/747 primers: 22 of 50 pools were positive (minimum prevalence, 14.7%). However, sequencing of the PCR products did not show complete homology with A. phagocytophilum (91%) while the closest relationship (95%) was found to "Candidatus Ehrlichia walkefii". The results indicate a need for care in interpretation of Anaplasma PCR results and for PCR optimization for detecting A. phagocytophilum in ticks.     

Modeling the nucleus and jets of comet 81P/Wild 2 based on the Stardust encounter data

We interpret the nucleus properties and jet activity from the Stardust spacecraft imaging and the onboard dust monitoring system data. Triangulation of 20 jets shows that 2 emanate from the nucleus dark side and 16 emanate from sources that are on slopes where the Sun's elevation is greater than predicted from the fitted triaxial ellipsoid. Seven sources, including five in the Mayo depression, coincide with relatively bright surface spots. Fitting the imaged jets, the spikelike temporal distribution of dust impacts indicates that the spacecraft crossed thin, densely populated sheets of particulate ejecta extending from small sources on the rotating nucleus, consistent with an emission cone model.     

Morphometric analysis of Hofbauer cells in normal placenta and chorioamnionitis in humans

Hofbauer cells are macrophages residing in the stroma of placental villi and play a number of roles during normal pregnancy, as well as pathological conditions. A morphometric analysis of Hofbauer cells, in particular to investigate the number of cells, their size and shape in samples of normal human placenta from 1st trimester, term and with chorioamnionitis was performed. Tissue samples were immunostained for CD206 antigen and evaluated using ImageJ software. We detected significant changes in number and morphology of HBCs between normal placenta and placenta with chorioamnionitis samples. In chorioamnionitis, the cells were unevenly distributed within the villi, generally present in higher numbers, larger and more elongated than those in normal 1st trimester and term placenta.     

Results of arbovirological examination of birds of the family Hirundinidae in Czechoslovakia

Migratory birds (swallow, Hirundo rustica; sand martin, Riparia riparia; house martin, Delichon urbica) caught in southern Moravia (Czechoslovakia) in 1984-87 were examined for arbovirus infections. Isolation experiments were carried out using blood samples of 183 birds (52 swallows, 107 sand martins, and 24 house martins). The results were negative. Serological examinations of 136 birds (36 swallows, 86 sand martins, and 14 house martins) were made by haemagglutination-inhibition test (HIT) using 6 arboviral antigens of the genera Alphavirus (Sindbis--SIN) and Flavivirus (tick-borne encephalitis--TBE, West Nile--WN) and of the family Bunyaviridae (Tahyna--TAH, Calovo, CVO, and Bhanja--BHA). Antibodies against all of the tested viruses were detected at different rates: SIN 2.9%, TBE 1.5%, WN 1.5%, TAH 4.4%, CVO 1.5%, and BHA 2.2%. The titres ranged from 1.20 to 1.80.     

The systemic effects of juvenoids on the red firebug Pyrrhocoris apterus and on the pea aphid Acyrthosiphon pisum with data on life table response

BACKGROUND: A series of juvenoid alcohols and their glycosidic derivatives (juvenogens), synthesized at the Institute of Organic Chemistry and Biochemistry in Prague, commercially used juvenoids and the natural derivatives of juvabione were evaluated for their systemic juvenilizing effect on the red firebug, Pyrrhocoris apterus L., and on the pea aphid, Acyrthosiphon pisum Harris. A life table response experiment was designed, and demographic characteristics were computed for a cohort of A. pisum following chronic exposure to a range of concentrations of the selected trans-isomer of carbamate juvenoid 8 applied via the broad bean (Vicia faba L.) root system. RESULTS: Using the ratio of topical and per os activities, promising effects were found in two alkyl beta-D-glucopyranosides (3 and 9) and the trans-isomer of carbamate juvenoid 8 in tests on P. apterus. In A. pisum, the highest systemic activity was found in tests with the trans-isomer of carbamate juvenoid 8. The longevity, the number of offspring per female and the number of offspring per reproducing female significantly decreased with concentrations of 0.05 mg mL(-1) and higher. While the net reproductive rate R(0) and the intrinsic rate of natural increase r(m) displayed similar trends, the generation time G varied slightly between 11.6 and 12.8 days. CONCLUSION: Expected systemic activity of glycosidic juvenogens in P. apterus was not confirmed by exposure of the pea aphid on broad bean treated with aqueous solutions of the compounds. Nevertheless, the carbamate juvenoid alcohol 8 displayed a considerable juvenilizing effect on A. pisum in screening tests. Furthermore, this compound indicated a sublethal effect as the realized fecundity U(x) decreased disproportionately to the age-specific survival L(x) with increased concentration. The population parameters are compared with the data in similar demographic studies and are discussed together with the possibilities of using the compounds of this structural type in practice.