Saliva-activated transmission of Borrelia afzelii Canica, Nato, du Merle, Mazie, Baranton et Postic, 1993 was demonstrated using salivary gland extract (SGE) from Ixodes ricinus (L., 1758) ticks and C3H mice. Injection of Borrelia spirochaetes together with SGE increased the level of bacteraemia and accelerated the appearance of bacteria in the urinary bladder, compared with the injection of spirochaetes alone. More I. ricinus nymphs became infected when feeding on mice inoculated with B. afzelii plus SGE. Analysis of cytokines produced by cells of draining lymph nodes from SGE-treated mice showed a suppression of proinflammatory cytokines IFN-γ, IL-6 and GM-CSF following a transient upregulation in comparison with the control mice infected without SGE.
The establishment of a dose-response relationship and its quantification is the usual procedure for analysing drug action on an isolated organ. However, the time course of the effect seems to be an inherent characteristic of the agonist which produces it. In our study, we have analyzed the time-response curves of four cholinergic agonists (acetylcholine, methacholine, carbachol and bethanechol) which produce tonic contractions of the isolated rat gastric fundus. The order of affinity of agonists to muscarinic receptors on the rat fundus were carbachol > bethanechol > methacholine > acetylcholine (Ka values: 46 ±12, 84±21, 380±110 and 730±120 nM, respectively). The effective concentrations which produced 60 % of the maximal response (EC5Q) were used for establishing the time-response curves. The time-response curves were also recorded after partial alkylation of muscarinic receptors with phenoxybenzamine, after exposure of the isolated rat fundus to physostigmine and after addition of supramaximal concentrations of the agonists. The experimental time-response curve for acetylcholine was on the extreme left, followed by curves for methacholine, bethanechol and carbachol, respectively. Phenoxybenzamine and supramaximal doses of the agonists did not change the order of response development in time, but supramaximal doses shifted all curves to the left and phenoxybenzamine shifted all time-response curves to the right. Only physostigmine shifted the time-response curve for methacholine to the right. The results of our study suggest that the response rate of the isolated rat gastric fundus to cholinergic agonists depends on the intrinsic activity of these agents, but not on their affinity for muscarinic receptors.
The sequence of changes in circulating immune cells and in free radical production was studied during the small intestine reperfusion. Rat small intestine ischemia/reperfusion was induced by a 45 min superior mesenteric artery occlusion followed by a 4-hour reperfusion. Samples of peripheral blood were collected every 20 min during reperfusion. While the number of polymorphonuclear leukocytes increased significantly both in the sham-operated controls and the experimental group (about 400 % at the end of reperfusion), a decrease in lymphocyte counts to 60 % was observed in the experimental group only. Although there were no changes in the counts of total T lymphocytes, a significant reduction in B cell counts was observed. Flow-cytometrical measurements showed no changes in the Tc subpopulation, while the Th subpopulation increased in the experimental group only. Free radical generation in blood (luminometric measurements) increased gradually and reached an eight-fold level by the end of reperfusion in both groups. Thus, it has been shown that the increase in free radical production is mainly due to the increased number of polymorphonuclear leukocytes mobilized already at the initial stages of reperfusion. The reduction in B lymphocyte population is probably due to homing mechanisms., J. Hamar, I. Rácz, M. Číž, A. Lojek, É. Pállinger, J. Fűrész., and Obsahuje bibliografii
Time of concentration (TC) of surface flow in watersheds depends on the coupled response of hillslopes and stream networks. The important point in this background is to study the effects of the geometry and the shape of complex hillslopes on the time of concentration considering the degree of flow convergence (convergent, parallel or divergent) as well as the profile curvature (concave, straight or convex). In this research, the shape factor of complex hillslopes as introduced by Agnese et al. (2007) is generalized and linked to the TC. A new model for calculating TC of complex hillslopes is presented, which depends on the plan shape, the type and degree of profile curvature, the Manning roughness coefficient, the flow regime, the length, the average slope, and the excess rainfall intensity. The presented model was compared to that proposed by Singh and Agiralioglu (1981a,b) and Agiralioglu (1985). Moreover, the results of laboratory experiments on the travel time of surface flow of complex hillslopes were used to calibrate the model. The results showed that TC for convergent hillslopes is nearly double those of parallel and divergent ones. TC in convex hillslopes was very close to that in straight and concave hillslopes. While the effect of convergence on TC is considerable, the curvature effect confirmed insignificant. Finally, in convergent hillslopes, TC increases with the degree of convergence, but in divergent hillslopes, it decreases as degree of divergence increases.
Time sensitivity seems to affect our intuitive evaluation of the reasonable risk of fallibility in testimonies. All things being equal, we tend to be less demanding in accepting time sensitive testimonies as opposed to time insensitive testimonies. This paper considers this intuitive response to testimonies as a strategy of acceptance. It argues that the intuitive strategy, which takes time sensitivity into account, is epistemically superior to two adjacent strategies that do not: the undemanding strategy adopted by non-reductionists and the cautious strategy adopted by reductionists. The paper demonstrates that in adopting the intuitive strategy of acceptance, one is likely to form more true beliefs and fewer false beliefs. Also, in following the intuitive strategy, the listener will be fulfilling his epistemic duties more efficiently.