PARTICIPATION OF Hi- AND H 3-RECEPTORS IN THE REGULATION OF GUINEA-PIG TRACHEAL TONE - INFLUENCE OF INDOMETHACIN

The tracheal tone is influenced by histaminergic receptors and by the epithelium derived relaxing factor (EpDRF) which contains metabolites of arachidonic acid. The aims of the present study were the following: 1) to investigate the role of Hi- and Нз-receptors in the tracheal tone regulation using as test substances histamine (H), the Hi-receptor antagonist mepyramine and the Нз-receptor agonist (R)a-methylhistamine [(R)a -MHA]; 2) to study the influence of the cyclooxygenase (COX) inhibitor indomethacin on the tracheal responsiveness to the examined substances. The experiments were carried out on isolated guinea-pig tracheal rings. Histamine at cumulative concentrations contracts the trachea. In the presence of mepyramine the concentration- response curves to H are shifted to the right that proves the concept of the Hi-receptor mediated tracheal contraction. In the presence of indomethacin the concentration-response curves to H are shifted to the left and the maximal contraction is significantly increased due to the inhibition of the COX pathway. (R)oc-MHA at concentrations up to lxlfH M leads to a slight tracheal contraction, which is probably Hi-receptor mediated as it is reduced in the presence of mepyramine. The ЗхКИ M concentration of (R)a-MHA relaxes the trachea probably due to its Нз-receptor agonistic activity. In the presence of indomethacin this relaxation is turned to a further contraction. After tracheal precontraction by H, (R)a-MHA concentration dependently relaxes the trachea. This spasmolytic effect is insignificantly influenced by mepyramine and is almost completely abolished in the presence of indomethacin, which shows that it is probably due to an increased production of metabolites of arachidonic acid

Microscopic mechanisms of thermal and driven diffusion of non rigid molecules on surfaces

The motion of molecules on solid surfaces is of interest for technological applications such as catalysis and lubrication, but it is also a theoretical challenge at a more fundamental level. The concept of activation barriers is very convenient for the interpretation of experiments and as input for Monte Carlo simulations but may become inadequate when mismatch with the substrate and molecular vibrations are considered. We study the simplest objects diffusing on a substrate at finite temperature $T$, namely an adatom and a diatomic molecule (dimer), using the Langevin approach. In the driven case, we analyse the characteristic curves, comparing the motion for different values of the intramolecular spacing, both for T=0 and $T\ne 0$. The mobility of the dimer is higher than that of the monomer when the drift velocity is less than the natural stretching frequency. The role of intramolecular excitations is crucial in this respect. In the undriven case, the diffusive dynamics is considered as a function of temperature. Contrary to atomic diffusion, for the dimer it is not possible to define a single, temperature independent, activation barrier. Our results suggest that vibrations can account for drastic variations of the activation barrier. This reveals a complex behaviour determined by the interplay between vibrations and a temperature dependent intramolecular equilibrium length.Comment: 6 pages, 5 figures, Proceeding of the EMRS 2002 Conference, to be published in Thin Solid Film

Deroceras panormitanum and congeners from Malta and Sicily, with a redescription of the widespread pest slug as Deroceras invadens n. sp.

The name Deroceras panormitanum is generally applied to a terrestrial slug that has spread worldwide and can be a pest; earlier this tramp species had been called Deroceras caruanae. Neither name is appropriate. The taxonomic descriptions apply to a species from Sicily and Malta. This true D. panormitanum and the tramp species are distinct in morphology and mating behaviour. For instance, the penial caecum of D. panormitanum is more pointed, everting faster at copulation. The size of the penial lobe varies considerably in preserved specimens but is always prominent at copulation. D. panormitanum is distinct from the Maltese endemic Deroceras golcheri, but a phylogeny based on mtDNA COI sequences implies that they are more closely related than is the tramp species. D. golcheri has a still closer counterpart on Sicily, but we leave the taxonomy of this species X unresolved. In interspecific crosses, D. panormitanum may transfer sperm to the partner's sarcobelum whereas the partner fails to evert its penis (D. golcheri) or to transfer sperm (the tramp species). Names previously applied to the tramp species originally referred to D. panormitanum or are otherwise invalid, so it is here formally redescribed as D. invadens. Deroceras giustianum Wiktor, 1998 is synonymised with D. panormitanum

L-cysteine adsorption structures on Au(111) investigated by scanning tunneling microscopy under ultrahigh vacuum conditions

Kühnle A, Linderoth TR, Schunack M, Besenbacher F. L-cysteine adsorption structures on Au(111) investigated by scanning tunneling microscopy under ultrahigh vacuum conditions. Langmuir. 2006;22(5):2156-2160.Adsorption structures formed upon vapor deposition of the natural amino acid L-cysteine onto the (111) surface of gold have been investigated by scanning tunneling microscopy under ultrahigh vacuum conditions. Following deposition at room temperature and at cysteine coverages well below saturation of the first monolayer, we found coexistence of unordered molecular islands and extended domains of a highly ordered molecular overlayer of quadratic symmetry. As the coverage was increased, a number of other structures with local hexagonal order emerged and became dominant. Neither of the room temperature, as-deposited, ordered structures showed any fixed rotational relationship to the underlying gold substrate, suggesting a comparatively weak and nonspecific molecule-substrate interaction. Annealing of the cysteine-covered substrate to 380 K lead to marked changes in the observed adsorption structures. At low coverages, the unordered islands developed internal order and their presence started to perturb the appearance of the surrounding Au(111) herringbone reconstruction. At coverages beyond saturation of the first monolayer, annealing led to development of a (root 3 x root 3)R30 degrees superstructure accompanied by the formation of characteristic monatomically deep etch pits, i.e., the behavior typically observed for alkanethiol self-assembled monolayers on Au(111). The data thus show that as-deposited and thermally annealed cysteine adsorption structures are quite different and suggest that thermal activation is required before vacuum deposited cysteine becomes covalently bound to single crystalline Au(111)

Vector-borne and other pathogens of potential relevance disseminated by relocated cats

Large populations of unowned cats constitute an animal welfare, ecological, societal and public health issue worldwide. Their relocation and homing are currently carried out in many parts of the world with the intention of relieving suffering and social problems, while contributing to ethical and humane population control in these cat populations. An understanding of an individual cat’s lifestyle and disease status by veterinary team professionals and those working with cat charities can help to prevent severe cat stress and the spread of feline pathogens, especially vector-borne pathogens, which can be overlooked in cats. In this article, we discuss the issue of relocation and homing of unowned cats from a global perspective. We also review zoonotic and non-zoonotic infectious agents of cats and give a list of practical recommendations for veterinary team professionals dealing with homing cats. Finally, we present a consensus statement consolidated at the 15th Symposium of the Companion Vector-Borne Diseases (CVBD) World Forum in 2020, ultimately to help veterinary team professionals understand the problem and the role they have in helping to prevent and manage vector-borne and other pathogens in relocated cats