Investigations of the interactions between aphids and ants in multispecies ant communities and an experimental investigation of some ethological aspects of ant-aphid interactions were carried out in mixed forests at Novosibirsk Academic Centre, from 1998-2002. The eight species of ants investigated were characterized by different levels of territorial organization and interaction with aphids, which were associated with different degrees of specialization of the worker ants. The most myrmecophilous species of aphids (24 out of 33 species identified) were associated with the red wood ants. By placing Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae) in aphid colonies it was shown that only ants with large protected territories attacked the adults and larvae of the predator. Other species of ants either protected aphids only from adult ladybirds or did not guard them at all. Moreover, only individuals of Formica s. str., which has specialized workers, did not switch to collecting protein food. However, aphids make up a considerable part of the prey of ants, in which non-myrmecophilous aphids predominate (about 60-100% of the aphid prey). Moreover, ants only killed unattended or damaged myrmecophilous aphids. Formica s. str., which has the highest level of social and territorial organization, provides aphids with the most services and is the dominant species forming symbiotic relationships with aphids in the communities studied.
Blokátory angiotenzinových receptorů typu 1 (AT1-blokátory, sartany) patří mezi základní antihypertenzní látky vhodné pro monoterapii i kombinační léčbu hypertenze. AT1-blokátory mají srovnatelné účinky s dalšími hlavními třídami antihypertenziv včetně ACE-inhibitorů. Dle současných doporučení České společnosti pro hypertenzi jsou sartany spolu s ACE-inhibitory a blokátory kalciových kanálů považovány za tzv. univerzální antihypertenziva. Mají ze všech antihypertenziv nejméně nežádoucích účinků a nemocní léčení sartany vykazují nejlepší dlouhodobou perzistenci k léčbě. V článku jsou diskutovány mechanizmy antihypertenzního účinku jakož i srovnání antihypertenzních účinků sartanů s dalšími antihypertenzními látkami. Jsou uvedeny výsledky větších klinických studií se sartany a indikace u arteriální hypertenze., Angiotensin receptor antagonists (AT1-blockers) are considered as one of the major classes of antihypertensive drugs suitable for monotherapy as well as for combination treatment. AT1-blockers have comparable antihypertensive efficacy with other major classes of antihypertensive drugs. AT1-blockers are considered by current guidelines of Czech society of hypertension altogether with ACE-inhibitors and calcium channel blockers as universal antihypertensive drug class. AT1-blockers has the lowest profile of side-effects among all antihypertensive drug classes and thus very high persistence to therapy. Mechanisms of antihypertensive effects of AT1-blockers are discussed altogether with the results of large clinical trials and indications in the treatment of hypertension., and Jiří Widimský Jr.
Male rats received estradiol benzoate in a long acting microcrystalline suspension (1 mg/rat i.m., twice a week), methylene blue (MB) 0.5 % in the food and the combination of estradiol and MB. After three weeks, MB partially inhibited the growth response of the anterior pituitary to estradiol and it partially inhibited the increase of cAMP content in anterior pituitary. The increase of anterior pituitary cGMP content was not modified by MB, neither the ratio cAMP/cGMP in the anterior pituitary which, however, decreased after estradiol. This decrease was not modified by MB. On the other hand, the prolactin (PRL) increase in the blood after estradiol was inhibited by MB, although the prolactin content in the anterior pituitary was not. Methylene blue alone did not change blood prolactin concentration, but it unexpectedly elevated blood thyroxine levels and this effect was partially inhibited by simultaneous estradiol treatment.
Seven Gymnura altavela (Linnaeus, 1758) (Elasmobranchii, Myliobatiformes) caught off the Tunisian coast were examined for endoparasites during a three-year period (1995-1998). A phyllobothriid cestode new to science was found in the spiral intestine of all host specimens. The presence of a tetrabothridiate scolex, bothridia lacking an apical sucker, laciniate strobila, and possession of postvaginal testes are sufficient to place this species in the genus Anthobothrium Van Beneden, 1850. In this genus, we consider that only two species, both previously reported from carcharhiniform sharks, are valid: Anthobothrium cornucopia Van Beneden, 1850 and A. laciniatum Linton, 1890. Anthobothrium altavelae sp. n. can be distinguished from its congeners by its length, strobila morphology, and the number of testes. The taxonomic position of the species attributed to Anthobothrium parasitic in gymnurids is discussed.