Effect of the compound L-mimosine in an in vivo model of chronic granuloma formation induced by potassium permanganate (KMNO4).

The plant amino acid L-mimosine has recently been suggested to inhibit cells at a regulatory step in late G phase before establishment of active DNA replication forks. In addition, L-mimosine is an extremely effective inhibitor of DNA replication in chromosomes of mammalian nuclei. In this work, the effect of L-mimosine on chronic inflammation induced by dorsal injections of 0.2 ml of a 1:40 saturated crystal solution of potassium permanganate in mice, was studied. Seven days afterwards, all mice developed a subcutaneous granulomatous tissue indicative of chronic inflammatory response at the site of infection. The intraperitoneal administration of L-mimosine (200 μg/dose) to the potassium permanganate treated mice for 5 consecutive days (the first at the same time of inoculation of the KMnO4), produced a significant decrease in size and weight of the granuloma when compared to mice not treated with L-mimosine (controls). In addition, in all mice treated with L-mimosine, there was a strong inhibition of tumor necrosis factor alpha that was revealed in the serum (P<0.05) and in the minced granulomas. Interleukin-6 was not detected in the serum of treated and untreated mice. These findings show for the first time, that L-mimosine may have an anti-inflammatory effect on chronic inflammation and an inhibitory effect on tumor necrosis factor alpha and interleukin-6 generation in supernatant fluids of minced granulomas

Autoimmunity and parasites.

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Seasonal differences of corticosterone metabolite concentrations and parasite burden in northern bald ibis (Geronticus eremita): The role of affiliative interactions

The reproductive season is energetically costly as revealed by elevated glucocorticoid concentrations, constrained immune functions and an increased risk of infections. Social allies and affiliative interactions may buffer physiological stress responses and thereby alleviate associated effects. In the present study, we investigated the seasonal differences of immune reactive corticosterone metabolite concentrations, endoparasite burden (nematode eggs and coccidian oocysts) and affiliative interactions in northern bald ibis (Geronticus eremita), a critically endangered bird. In total, 43 individually marked focal animals from a freeranging colony were investigated. The analyses included a description of initiated and received affiliative interactions, pair bond status as well as seasonal patterns of hormone and endoparasite levels. During the reproductive season, droppings contained parasite eggs more often and corticosterone metabolite levels were higher as compared to the period after reproduction. The excretion rate of endoparasite products was lower in paired individuals than in unpaired ones, but paired animals exhibited higher corticosterone metabolite concentrations than unpaired individuals. Furthermore, paired individuals initiated affiliative behaviour more frequently than unpaired ones. This suggests that the reproductive season influences the excretion patterns of endoparasite products and corticosterone metabolites and that affiliative interactions between pair partners may positively affect endoparasite burden during periods of elevated glucocorticoid levels. Being embedded in a pair bond may have a positive impact on individual immune system and parasite resistance

Tick infestation of dogs in Thessaloniki, northern Greece

Ticks were collected from 249 dogs, admitted over a one-year period (1996-1997) to a Veterinary Teaching Hospital and four private veterinary practices located in the county of Thessaloniki, Greece. A total of 2812 ticks (Acari: Ixodidae) were collected, of which 2511 (89.3%) were Rhipicephalus sanguineus (Latreille) adults (1070 males, 1441 females), 156 (5.5%) R. turanicus Pomerantsev adults (35 males, 121 females), 100 (3.6%) Rhipicephalus spp. nymphs and 45 (1.6%) Rhipicephalus spp. larvae. Dogs living outdoors, in rural areas and in close proximity to farm animals, were infested with higher numbers of ticks than dogs living indoors. Tick attachment sites were recorded on 237 dogs, harbouring a total of 1711 ticks. The most heavily infested sites were, in decreasing frequency, the ear pinnae, neck, interdigital skin folds, trunk, head, ventrum, extremities and the tail. Cutaneous lesions at the attachment sites were noticed in 129 dogs and then mainly in the more severely infested animals