Receptors of the PAR Family as a Link between Blood Coagulation and Inflammation

Blood coagulation plays a key role among numerous mediating systems that are activated in inflammation. Receptors of the PAR family serve as sensors of serine proteinases of the blood clotting system in the target cells involved in inflammation.Activation of PAR-1 by thrombin and of PAR-2 by factor Xa leads to a rapid expression and exposure on the membrane of endothelial cells of both adhesive proteins that mediate an acute inflammatory reaction and of the tissue factor that initiates the blood coagulation cascade. Certain other receptors (EPR-1, thrombomodulin, etc.), which can modulate responses of the cells activated by proteinases through PAR receptors, are also involved in the association of coagulation and inflammation together with the receptors of the PAR family. The presence of PAR receptors on mast cells is responsible for their reactivity to thrombin and factor Xa and defines their contribution to the association of inflammation and blood clotting processes.     

Population Dynamics of the Bream Abramis brama in Lake Peipus

Journal of Ichthyology - Population dynamics of the bream Abramis brama in lakes Peipsi and Pihkva for the period from 1980 to 2009 has been studied by means of cohort models. Bream stock increased...     

Modulation of mast cell activity by a peptide agonist of the thrombin receptor: role of nitric oxide.

The effect of a thrombin receptor agonist peptide (TRAP-6) on the release of nitric oxide (NO) and platelet activating factor (PAF) from resting and calcium-ionophore (A23187)-activated rat peritoneal mast cells (RPMC) was studied using a platelet aggregation bioassay. RPMC spontaneously released NO, which inhibited TRAP-6-, ADP-, and PAF-stimulated platelet aggregation. This effect of NO was abolished by the addition of an NO binding agent, oxyhemoglobin (oxyHb), to the platelet suspension. The RPMC-induced suppression of platelet aggregation was completely inhibited by the NO-synthase inhibitor L-NAME. TRAP-6 and its high affinity analog haTRAP stimulated the rapid release of NO from RPMC. The effect of TRAP-6 was inhibited by pretreatment of the RPMC with L-NAME or with the inhibitor of the constitutive NO-synthase isoform (cNOS) calmidazolium. TRAP-6 inhibited PAF release from A23187-activated RPMC via an NO-dependent mechanism. Platelet aggregation induced by PAF release from activated RPMC was also confirmed in experiments using the PAF receptor antagonist ginkgolide B. Thus, TRAP-6 is a rapidly acting modulator of mast cell reactivity; it stimulates NO release and inhibits PAF secretion.     

Convergence rotatory nystagmus under unusual conditions of semicircular canal and otolith stimulation

The characteristics of interaction between two vestibular subsystems (otiliths and semicircular canals) were studied by means of binocular (bilateral) videooculographic recording of eye movements in 43 men aged from 19 to 41 years that had been found healthy upon aviation physical examination. The time course of horizontal vestibular nystagmus was analyzed separately for each eye in subjects who bent forward and straightened up in the sagittal plane while being rotated about the vertical body axis in an electrically driven rotating chair. This combined rotation caused interocular asymmetric nystagmus in 91% of the subjects and convergence rotatory nystagmus in 42% of the subjects. A hypothesis on the mechanism of interocular asymmetric nystagmus caused by the combined rotation and convergence rotatory nystagmus as its special case has been advanced. The hypothesis allows for independent nystagmic mechanisms (subsystems) for the right and left eyes.     

Occurrence of natural tularemia foci in Kamchatka

The focus of tularemia in the Ust-Kamchatsky region belongs probably to the flood-plain and swamp type with muskrats and tundra voles being the main carriers. In autumn 1980 for the first time three cultures were isolated in this region: 1 from a tundra vole and 2 from muskrats. The presence of antibodies to tularemia antigen in Norway rats was revealed in the passive hemagglutination test.     

Serum protein polymorphisms in the population of south Yemen

The Gc, Hp, and Tf polymorphisms were studied in the population of South Yemen. The gene frequencies were in agreement with those of other populations in the Middle East. There was an indication of local variations due to ethnic heterogeneity, e.g. a relatively high frequency of TfD in 1 of the 5 subpopulations studied.     

5-(Perylen-3-ylethynyl)uracil Derivatives Inhibit Reproduction of Respiratory Viruses

Russian Journal of Bioorganic Chemistry - In this work, we describe the synthesis of 5-(perylen-3-ylethynyl)uridine and its ability to effectively inhibit the replication of respiratory disease...