Ultrasonographic examination of the adrenal gland and evaluation of the hypophyseal-adrenal axis in 20 cats

The adrenal glands of 20 healthy, non-sedated cats were examined ultrasonographically; visualisation and assessment was possible in all cases. In comparison with the surrounding tissue, the adrenal glands were hypoechoic and two distinct zones could be differentiated in six of the cats. The length and width of the adrenal glands varied from 0.45 to 1.37 cm and 0.29 to 0.53 cm, respectively, and both dimensions could be reliably reproduced. The adrenal glands did not differ between male and female cats, and, in comparison to dogs, those of cats are more easily visualised ultrasonographically. The basal cortisol value ranged from 2.0 to 79 micrograms/litre. Values 30 and 60 minutes after administration of ACTH (0.125 mg/cat intramuscularly) varied from 36 to 126 micrograms/litre. The basal value of aldosterone ranged from 4 to 618 pg/ml. Values 30 and 60 minutes after administration of ACTH varied from 100 to 832 pg/ml. In all cats, suppression of the cortisol value below the level of detection (< 2.0 micrograms/litre) occurred four and eight hours after the administration of dexamethasone (0.1 mg/kg intravenously).     

Stability and inactivation of vesicular stomatitis virus,a prototype rhabdovirus

Viruses may remain infectious outside the host cell for considerable time and represent a source of accidental infection if not properly inactivated. In this study, the survival of vesicular stomatitis virus (VSV) in suspension and dried on surfaces was analyzed. In addition, the sensitivity of VSV to disinfectants and physicochemical changes was investigated. VSV showed a notable stability in suspension at 4 °C with virus titers remaining high over several weeks. The presence of serum proteins had a stabilizing effect on virus infectivity, whereas elevated temperatures reduced survival times. VSV dried on polystyrene, glass or stainless steel surfaces remained infectious for at least 6 days at ambient temperature. VSV showed a remarkable resistance to extreme pH in particular in the alkaline range, but could be rapidly inactivated by heating at 55 °C or higher. The virus was highly sensitive to inactivation by commonly used disinfectants such as aldehydes, alcohols, and detergents. The high stability of VSV on surfaces and in suspension may facilitate dissemination of the virus in livestock by contaminated feeding and water troughs, hands, and milking equipment. This knowledge on the sensitivity of VSV to disinfectants will help to set up appropriate hygiene measures.     

Bryozoan monticules: excurrent water outlets?

Monticules, regularly arranged modified areas on Paleozoic Bryozoa, may represent regions from which water currents produced by lophophores of adjacent feeding zoids escaped. Such circulation Patterns have been observed Recent forms.     

Anatomical differences in the structural elements of fluid passage of Scots pine sapwood with contrasting treatability

Treatability of wood is a function of anatomical properties developed under certain growing conditions. While Scots pine sapwood material normally is considered as easy to impregnate, great variations in treatability can be observed. In order to study anatomical differences in the structural elements of transverse fluid passage, wood material with contrasting treatability has been compared. Ray composition and resin canal network, membrane areas of fenestriform pits in the cross-field as well as dimension and properties of bordered pits were investigated. The results showed large anatomical differences between the two contrasting treatability groups. Refractory Scots pine sapwood samples developed more rays per mm² tangential section, while they were on average lower in cell numbers than rays found in easily treatable material. Easily treatable material had more parenchyma cells in rays than refractory material. At the same time, a larger membrane area in fenestriform pits in the cross-field was observed in the easily treatable sample fraction. Differences in the composition of resin canal network were not observed. Refractory samples developed on average smaller bordered pit features, with relatively small formed pit apertures compared to the easily treatable samples. In refractory Scots pine sapwood material, the structural elements of fluid passage such as bordered pit dimensions, fenestriform pits in the cross-field and parenchyma cells were altogether developed in smaller dimensions or number. Wood samples from better growing conditions and sufficient water supply showed a better treatability in this study.     

Selective consumption and digestion of litter microbes by Porcellio scaber (Isopoda: Oniscidea)

In feeding preference tests with artificial diets consisting of food sources inoculated with different types of litter microbes, Porcellio scaber was capable of discriminating between different microbe species. Generally, microbial colonisation increased the attractiveness of a given food source, in particular, when the food source was of low quality (cellulose) and when food sources were inoculated with single species of actinomycetes (Streptomyces celluloflavus or Pseudonocardia autotrophica). In most cases, actinomycetes (Gram-positive bacteria) were preferred over both Gram-negative bacteria and fungi, whether or not these microbes exhibited cellulolytic activity. Enzymatic in vitro digestion of both the Gram-positive S. celluloflavus and P. autotrophica was significantly greater than that of Gram-negative bacteria (Pseudomonas fluorescens and Myxococcus xanthus) or fungi (Chaetomium globosum and Fusarium ventricosum). S. celluloflavus biomass was more effectively incorporated into isopod biomass than that of fungi and Gram-negative bacteria; P. autotrophica was more effectively incorporated into isopod biomass than that of Gram-negative bacteria. Based on these results, we hypothesise that P. scaber preferentially feeds on those microbes that it can readily digest. Whether this holds true for other Gram-positive bacteria or for other detritivores awaits investigation.     

Cytochrome P450 mediated pyrethroid resistance in European populations of Meligethes aeneus (Coleoptera: Nitidulidae)

Pollen beetle, Meligethes aeneus (Coleoptera: Nitidulidae) is a major pest on several million hectares in European winter oilseed rape cultivation. Synthetic pyrethroids have been successfully used for many years to keep them under economic damage thresholds. Recently wide-spread resistance development to pyrethroids in pollen beetle populations was described in many European countries, including Germany, France, Poland, Denmark and others. Resistance monitoring is conducted by incubating beetles for 24 h in glass vials coated with different concentrations of lambda-cyhalothrin. Using such an assay format we were able to show cross-resistance to other pyrethroids, such as deltamethrin, cypermethrin, and to a somewhat lower extent bifenthrin, etofenprox and tau-fluvalinate. Here we also investigated in more detail in 27 different populations the biochemical mechanism of pyrethroid resistance. Synergism experiments revealed a high synergistic potential for piperonyl butoxide in vivo, whereas other compounds such as S,S,S-tributylphosphorotrithioate and diethylmaleimide failed to suppress pyrethroid resistance. Incubating microsomal fractions of pollen beetle with deltamethrin and subsequent LC–MS/MS analysis revealed 4-OH-deltamethrin as the major metabolite. Metabolite formation in vitro and pyrethroid resistance in vivo is correlated and inhibition trials with piperonyl butoxide, tebuconazole and aminobenzotriazole suggest the involvement of cytochrome P450′s. Furthermore we were able to show cross-resistance to tau-fluvalinate which is supported by the competitive inhibition of 4-OH-deltamethrin formation by increasing concentrations of tau-fluvalinate in microsomal hydroxylation assays. Although we provided clear experimental evidence for an oxidative mechanism of resistance in numerous populations, other mechanisms might be involved based on the data discussed.