Synthesis, computational and experimental pharmacological studies for (thio)ether-triazine 5-HT6R ligands with noticeable action on AChE/BChE and chalcogen-dependent intrinsic activity in search for new class of drugs against Alzheimer's disease

Alzheimer's disease is becoming a growing problem increasing at a tremendous rate. Serotonin 5-HT6 receptors appear to be a particularly attractive target from a therapeutic perspective, due to their involvement not only in cognitive processes, but also in depression and psychosis. In this work, we present the synthesis and broad biological characterization of a new series of 18 compounds with a unique 1,3,5-triazine backbone, as potent 5-HT6 receptor ligands. The main aim of this research is to compare the biological activity of the newly synthesized sulfur derivatives with their oxygen analogues and their N-demethylated O- and S-metabolites obtained for the first time. Most of the new triazines displayed high affinity (Ki < 200 nM) and selectivity towards 5-HT6R, with respect to 5-HT2AR, 5-HT7R, and D2R, in the radioligand binding assays. For selected, active compounds crystallographic studies, functional bioassays, and ADME-Tox profile in vitro were performed. The exciting novelty is that the sulfur derivatives exhibit an agonistic mode of action contrary to all other compounds obtained to date in this chemical class herein and previously reported. Advanced computational studies indicated that this intriguing functional shift might be caused by presence of chalcogen bonds formed only by the sulfur atom. In addition, the N-demethylated derivatives have emerged highly potent antioxidants and, moreover, show a significant improvement in metabolic stability compared to the parent structures. The cholinesterase study present micromolar inhibitory AChE and BChE activity for both 5-HT6 agonist 19 and potent antagonist 5. Finally, the behavioral experiments of compound 19 demonstrated its antidepressant-like properties and slight ability to improve cognitive deficits, without inducing memory impairments by itself. Described pharmacological properties of both compounds (5 and 19) allow to give a design clue for the development of multitarget compounds with 5-HT6 (both agonist and antagonist)/AChE and/or BChE mechanism in the group of 1,3,5-triazine derivatives

Antimicrobial prophylaxis in adults and children undergoing hematopoietic cell transplantation: 2021 Polish recommendations

Infections are still a major reason of morbidity and one of the most common causes of death after hematopoietic cell transplantation (HCT). Antimicrobial prophylaxis plays a crucial role in decreasing non-relapse mortality after HCT. The objective of this guideline paper is presentation of current recommendations of antimicrobial prophylaxis for children and adults after hematopoietic cell transplantation, prepared in cooperation of Polish scientific hematological societies. Recommendations were prepared by the working group and finally approved by all 23 Polish transplant centers for children and adults. Existing ECIL (European Conference on Infections in Leukemia) and EBMT (European Society of Blood and Marrow Transplantation) guidelines, as well as results of survey performed among all Polish transplant centers, were the background material for working group. Recommendations are presented in sections dedicated to antibacterial prophylaxis, antifungal prophylaxis, antiviral prophylaxis, as well as prophylaxis of toxoplasmosis and infections with Pneumocystis jiroveci. Recommendations on principles of vaccination against COVID-19 are provided based on the state of knowledge in September 2021. A section on guidelines of environmental prophylaxis is also presented