[ADULTS NEUROGENESIS AS A RESERVE FOR HEALTH PRESERVATION].

The article presents scientific evidence that new neurons from progenitor cells throughout life in almost all animals with a nervous system are an integral component of neuronal ontogenesis and plasticity.It has been shown that there are neural stem cells in the brain that give rise to adult neurogenesis, occurring primarily in the dentate gyrus, a subregion of the hippocampus important for learning, memory, and emotion. With age, there is a decrease in adult neurogenesis, which is associated with a decrease in cognitive functions. Newly formed neurons and «immature¼ neurons together constitute a potential reservoir of young cells («brain reserve¼) that can be used to prevent aging and/or delay the onset/reduce the impact of neurological disorders.The possibility of using neurogenic processes for therapeutic purposes to reduce pain and improve the quality of life of patients is implied.

[THE ISSUE OF THE IMPACT OF RADIOACTIVE SUBSTANCES ON PUBLIC HEALTH AND COUNTERMEASURES FOR RADIATION EXPOSURE AS A GLOBAL PROBLEM].

The widespread use in today's world of radioactive sources d in energy, medicine, engineering and construction, for contaminant tracking and food sterilization increases the likelihood of accidental exposure. The use of ionizing radiation and radioactive elements can directly or indirectly cause life-threatening complications, such as oncopathology, radiation burns, and impaired immunity. Pollution of the environment with radioactive elements and depletion of the ozone layer also contribute to an increase in the level of radiation exposure. To protect the health of the population living in contaminated areas and consuming locally produced products, it is necessary to organize a system for monitoring radioactive damage, as well as special anti-radiation protective measures in the field of agriculture and forestry, hunting and fishing, and providing the population with food. The purpose of the study is to analyze modern scientific data on the effect of ionizing radiation on reproductive function and modern approaches aimed at correcting its violations. Bibliographic, information-analytical methods and methods of comparative analysis were used.

[Multifocal brain lesions]. / Mnogoochagovye porazheniya golovnogo mozga.

Despite the current laboratory and instrumental approaches to the diagnosis, a patient with multiple brain lesions remains a difficult one. The reason is that these lesions can be caused by a variety of disorders, including rare ones and atypical forms. Distinguishing neoplastic lesions from non-neoplastic CNS disorders is crucial due to different treatment options. The authors report the case of a patient with multiple brain lesions, present a literature review of diseases to be differentially diagnosed with multifocal brain lesions and suggest a simple algorithm for the differential diagnosis. Timely clinical evaluation and a multidisciplinary approach are required for making a definitive diagnosis that is extremely important to start the appropriate therapy.

Structural principles of the wide substrate specificity of Thermoactinomyces vulgaris carboxypeptidase T. Reconstruction of the carboxypeptidase B primary specificity pocket.

Site-directed mutagenesis in the active site of Thermoactinomyces vulgaris carboxypeptidase T (CpT), which is capable of hydrolyzing both hydrophobic and positively charged substrates, resulted in five mutants: CpT1 (A243G), CpT2 (D253G/T255D), CpT3 (A243G/D253G/T255D), CpT4 (G207S/A243G/D253G/T255D), and CpT5 (G207S/A243G/T250A/D253G/T255D). These mutants step-by-step reconstruct the primary specificity pocket of carboxypeptidase B (CpB), which is capable of cleaving only positively charged C-terminal residues. All of the mutants retained the substrate specificity of the wild-type CpT. Based on comparison of three-dimensional structures of CpB and the CpT5 model, it was suggested that the lower affinity of CpT5 for positively charged substrates than the affinity of CpB could be caused by differences in nature and spatial location of Leu247 and Ile247 and of His68 and Asp65 residues in CpT and CpB, respectively, and also in location of the water molecule bound with Ala250. An additional hydrophobic region was detected in the CpT active site formed by Tyr248, Leu247, Leu203, Ala243, CH3-group of Thr250, and CO-groups of Tyr248 and Ala243, which could be responsible for binding hydrophobic substrates. Thus, notwithstanding the considerable structural similarity of CpT and pancreatic carboxypeptidases, the mechanisms underlying their substrate specificities are different.

Thiol-dependent serine proteinase from Paecilomyces lilacinus: purification and catalytic properties.

An extracellular thiol-dependent serine proteinase was isolated from culture medium filtrate of the microscopic fungus Paecilomyces lilacinus with a yield of 33%. The enzyme is inactivated by specific inhibitors of serine proteinases, phenylmethylsulfonyl fluoride, as well as by chloromercuribenzoate and mercury acetate, but is resistant to chelating agents. The proteinase has broad specificity, hydrolyzes proteins and p-nitroanilides of N-acylated tripeptides, exhibiting maximal activity in hydrolysis of substrates containing long hydrophobic and aromatic residues (norleucine, leucine, phenylalanine) as well as arginine at the P1 position. The enzyme has a molecular weight of 33 kD. The enzyme is most active at pH 10.0-11.5; it is thermostable and is characterized by broad optimum temperature range (30-60 degrees C), displaying about 25% of maximal activity at 0 degrees C. The N-terminal sequence of the enzyme (Gly-Ala-Thr-Thr-Gln-Gly-Ala-Thr-Gly/Ile-Xxx-Gly) has no distinct homology with known primary structures of serine proteinases from fungi and bacilli. Based on its physicochemical and enzymatic properties, the serine proteinase from P. lilacinus can be classified as a thiol-dependent subtilisin-like enzyme.

Syncope masquerading as a panic disorder: role of the subcutaneous loop recorder in eliciting the appropriate diagnosis.

The present case describes a 49-year-old woman with apparent panic disorder in whom the Reveal Plus, a newly developed subcutaneous loop recorder, was used to show that the panic attacks were secondary to prolonged episodes of ventricular asystole.

Proteinases of Legionella: phenylalanineaminopeptidase of L. pneumophila.

Phenylalanineaminopeptidase was isolated and purified from the culture filtrate of Legionella pneumophila by affinity chromatography on O-tert-butyl-L-threonyl-L-phenylalanyl-L-prolylglycyl-aminosilo chrom and by gel-filtration; a 401-fold purification with a yield of 18% was achieved. The enzyme was a metalloenzyme with a molecular weight of 35000 and a pI of 5.8. It was stable at pH 7-9 and had an activity optimum in the range of pH 8-9.5 with L-phenylalanine p-nitroanilide as substrate. Enzyme activity was highest towards the latter compound, substantially lower towards L-leucine p-nitroanilide and only marginal towards other p-nitroanilides. Besides phenylalanineaminopeptidase, a metalloproteinase and a serine proteinase were also detected in L. pneumophila culture filtrate.