CHARACTERISTICS OF OLOKIZUMAB PHARMACOKINETICS IN PATIENTS WITH NOVEL CORONAVIRUS INFECTION COVID-19

The aim of the article is to study pharmacokinetic characteristics of intravenous olokizumab in patients with moderate COVID-19 to relieve a hyperinflammation syndrome.

Materials and methods. The pharmacokinetic study was conducted as a part of a phase III clinical study (RESET, NCT05187793) on the efficacy and safety of a new olokizumab regimen (intravenous, at the doses of 128 mg or 256 mg) in COVID-19 patients. Plasma concentrations of olokizumab were determined by the enzyme immunoassay. The population analysis was performed using a previously developed pharmacokinetic model based on a linear two compartment.

Results. The pharmacokinetic analysis included the data from 8 moderate COVID-19 patients who had been administrated with olokizumab intravenously at the dose of 128 mg. According to the analysis results in this population, there was an increase in the drug clearance, compared with the data obtained in healthy volunteers and the patients with rheumatoid arthritis: 0.435, 0.178 and 0.147 l/day, respectively. The parameters analysis within the framework of a population pharmacokinetic model showed that the main factors for the increased olokizumab clearance are a high body mass index. In addition, the presence of COVID-19 itself is an independent factor in increasing the drug clearance.

Conclusion. After the intravenous olokizumab administration, an increase in the drug clearance is observed in moderate COVID-19 patients against the background of the disease course. The main contribution to the increased clearance is made by the characteristics of the population of COVID-19 patients associated with the risk of a severe disease and inflammation. When administered intravenously at the dose of 128 mg, a therapeutically significant olokizumab level was maintained throughout the acute disease phase for 28 days.

[Endocannabinoid signalling in the central nervous system of vertebrates and invertebrates]

A review. Up-to-date concepts of endocannabinoid signalling in central nervous system of vertebrates are summarized. An overview of receptor-mediated mechanisms of synaptic transmission modulation by endocannabinoids in the brain and possibilities of direct effects of some cannabinoids on voltage-gated ion channels and neuronal activity is given. In the second part of the article, studies of endocannabinoid system in different phyla of invertebrate animals, from hydra to sea urchin, are analyzed in detail.

Functional changes in the snail statocyst system elicited by microgravity

BACKGROUND

The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations.

METHODOLOGY/PRINCIPAL FINDINGS

In terrestrial gastropod snail we studied the impact of 16- (Foton M-2) and 12-day (Foton M-3) exposure to microgravity in unmanned orbital missions on: (i) the whole animal behavior (Helix lucorum L.), (ii) the statoreceptor responses to tilt in an isolated neural preparation (Helix lucorum L.), and (iii) the differential expression of the Helix pedal peptide (HPep) and the tetrapeptide FMRFamide genes in neural structures (Helix aspersa L.). Experiments were performed 13-42 hours after return to Earth. Latency of body re-orientation to sudden 90° head-down pitch was significantly reduced in postflight snails indicating an enhanced negative gravitaxis response. Statoreceptor responses to tilt in postflight snails were independent of motion direction, in contrast to a directional preference observed in control animals. Positive relation between tilt velocity and firing rate was observed in both control and postflight snails, but the response magnitude was significantly larger in postflight snails indicating an enhanced sensitivity to acceleration. A significant increase in mRNA expression of the gene encoding HPep, a peptide linked to ciliary beating, in statoreceptors was observed in postflight snails; no differential expression of the gene encoding FMRFamide, a possible neurotransmission modulator, was observed.

CONCLUSIONS/SIGNIFICANCE

Upregulation of statocyst function in snails following microgravity exposure parallels that observed in vertebrates suggesting fundamental principles underlie gravi-sensing and the organism's ability to adapt to gravity changes. This simple animal model offers the possibility to describe general subcellular mechanisms of nervous system's response to conditions on Earth and in space.

Cannabinoid regulation in identified synapse of terrestrial snail

In the terrestrial snail a direct monosynaptic glutamatergic connection between the primary sensory neuron and a premotor interneuron involved in withdrawal behaviour can be functionally identified using electrophysiological techniques. We investigated the involvement of cannabinoids in regulation of this synaptic contact. The results demonstrate that the specific binding sites for agonists to mammalian type 1 cannabinoid receptors (CB1Rs) exist in the snail's nervous system. Application of a synthetic cannabinoid agonist anandamide selectively changed the efficacy of synaptic contacts between the identified neurons. A decrease in the long-term synaptic facilitation of the synaptic contact elicited by high-frequency nerve tetanization in the presence of cannabinoid agonist anandamide was observed, suggesting a possible role of endocannabinoids in regulation of plasticity at this synaptic site. The selective antagonist of CB1Rs [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide] AM251 bath application was changing the efficacy of the synaptic contact only when the postsynaptic neuron had been intracellularly activated before its application. This observation implies an involvement of endocannabinoids in plasticity phenomena induced by activity in the postsynaptic target. Additional support of endocannabinoid involvement in synaptic function at this site was given by experiments in which AM251 blocked the short-term suppression of synaptic excitation evoked by low-frequency nerve tetanization, a phenomenon qualitatively similar to cannabinoid-dependent synaptically evoked suppression of excitation demonstrated in the mammalian nervous system. The results of the present study suggest an involvement of cannabinoids in the regulation of synaptic efficacy. Further, anandamide could be a candidate for an endogenous neuromessenger involved in plasticity processes.