Sergey Lytaev

Background: The main “peptic” cells of the gastric glands provide the body’s only source of pepsinogen synthesis and incretion. Small amounts of endogenously supplied pepsinogen in biological fluids play an important role in anabolic processes in the mother and newborn. The aim: This work aimed to analyze the dynamics of pepsinogen activity in the blood serum, saliva, urine, and coprofiltrate in pregnant women in each trimester of pregnancy and in the postpartum period, taking into account the body weight of the newborn—normal weight, underweight, and overweight. Methods: Data from studies involving non-pregnant (n = 45) and pregnant (n = 152) women with newborns with different weights were analyzed. There were 86 women with a normal-weight newborn, 34 women with an underweight newborn, and 32 women with an overweight newborn. Total proteolytic activity in biological fluids was determined using the spectrophotometric tyrosine (tyr) Kunitz–Northrop method modified by Korot’ko. A 2% solution of dry plasma was used as a substrate. Outcomes: In non-pregnant women, the blood proteolytic activity was 58.1 ± 1.4 tyr U/mL, and saliva at 1520.9 ± 112.2 tyr U/mL, urine at 4520.3 ± 154.3 tyr U/mL, and coprofiltrate at 442.2 ± 20.5 tyr U/mL. We established that the pepsinogen activity during pregnancy is distributed unevenly, taking into account the body weight of the newborn, and changes significantly in women with an underweight or overweight newborn. Conclusions: Pepsinogen homeostasis in pregnant women is maintained by renal and extrarenal pathways, and an important role is played by the salivary glands, with the most significant changes occurring in women with overweight and underweight newborns.

In the study of sensory processes, the visual system has received the most research compared to other sensory systems. The primary difference between visual and auditory perception lies in the nature of the stimuli and the reception processes: vision perceives electromagnetic radiation, while auditory perception perceives acoustic signals of mechanical origin. This review aims to analyze modern approaches and controversies to the mechanisms of auditory perception related to psychophysics, psychophysiology, psychopathology, modern research on hearing in human–computer interaction (HCI) systems, and machine learning methods. Modern studies of acoustic patterns include a comprehensive assessment of the physical characteristics of perception, complex nonverbal auditory cues, verbalization, perception and memory, as well as individual differences in auditory perception. An analysis of the scientific literature allowed us to conclude that acoustic signals transformed in the brain into auditory images retain (encode) a number of amplitude-temporal parameters of acoustic signals that facilitate auditory discrimination (filtering), but interfere with auditory detection (recognition). Signal processing often, but not necessarily, involves brain regions involved in other forms of perception. It depends on subvocalization, includes semantically interpreted information and expectations, pictorial (visual) and descriptive components, functions as a mnemonic, and is linked to individual musical ability and experience (although the mechanisms of this connection are unclear).

Consciousness is an integrative process that combines several executive functions, as well as the analytical and synthetic activity of the brain. In some psychopathological conditions, in particular, in schizophrenia, low-information "borderline" disorders of the executive functions and consciousness are often formed at the onset. The present study was aimed at assessing the integration of the bran alpha regulatory system and the modulation of consciousness based on the data of recording the alpha rhythm of resting state EEG associated with a decrease in the level of consciousness. The study involved 40 outpatients with actual symptomatic schizophrenia associated with neurocognitive and depressive symptoms, and 38 healthy subjects. Using the WinEEG, EEG Studio and Loreta-Key Viewer programs, we analyzed both non-specific physical parameters of alpha rhythm generation - index, frequency, amplitude, and physiological characteristics associated with executive functions - regularity, autorhythmicity (modulation) and stability of the EEG alpha rhythm. A line of indicators for the alpha rhythm in schizophrenia has been calculated based on coherence in different areas of the brain, the latent period of desynchronization, the average number of bursts, and the tone of the cerebral cortex.

Consciousness is the highest mental function that integrates attention, memory, individual experience, emotions, and all modalities of perception, information processing and other manifestations of higher nervous activity of a person. This research was aimed to theoretically substantiate the functional connection of the brain alpha regulatory system with the modulation of conscious activity and to identify pathological electroencephalography (EEG) patterns of the alpha rhythm characterizing a decrease in the level of consciousness. 40 patients (main group) with current symptomatic schizophrenia associated with neurocognitive and depressive symptoms, and 38 healthy subjects (control group) were examined. Both nonspecific physical parameters of the alpha wave process–index, frequency and amplitude, and physiological features of alpha oscillations–regularity, auto rhythmicity (modulation) and stability of the EEG alpha rhythm were analyzed with using WinEEG, EEG Studio, and Loreta-Key viewer programs. A line of indicators for the alpha rhythm in schizophrenia have been calculated–based on coherence in different brain areas, the latent period (LP) of desynchronization, the average number of bursts and the tone of the cerebral cortex.

Background: Enzymes secreted by the digestive glands are excreted from the body with urine, sweat and feces, and they are also removed from the blood due to their participation in the enzymatic provision of the secretion entering the gastrointestinal tract. Objective: The aim of this work was to analyze the activity of pepsinogen, amylase and lipase in the coprofiltrate of pregnant women in each trimester of pregnancy and in the postpartum period, taking into account the timing and type of delivery (term, premature, late delivery or cesarean section). Methods: Data from studies of non-pregnant (n = 45) and pregnant (n = 193) women were analyzed. The materials for preparation coprofiltrate were collected during delivery. Pepsinogen activity was determined by proteolytic activity at pH = 1.5–2.0 using the tyrosine spectrophotometric method, while amylase activity was determined by the amyloclastic method of Karavey, and lipolytic activity was determined by a unified kinetic method using olive oil as a substrate. Outcomes: A small amount of pepsinogen was excreted in the coprofiltrate, and while the level of its excretion increased after childbirth, it remained below the control values. At the same time, an increase in the amylolytic activity of the coprofiltrate was observed in all groups of pregnant women examined from the first to the third trimester of pregnancy. In pregnant women, multidirectional changes in lipase activity were observed depending on the timing and type of delivery. Conclusions: At the end of pregnancy, amylolytic activity increased in all women, and pepsinase activity decreased compared to the indicators of non-pregnant women. No reliable differences were found in the lipolytic activity of the coprofiltrate in pregnant women at the end of pregnancy and the indicators of non-pregnant women.

BACKGROUND: The prevalence of gestational diabetes mellitus in the world is increasing every year. However, there is a small number of studies on changes in enzymes of various classes in blood serum in gestational diabetes mellitus, and there are conflicting results regarding the concentration of individual enzymes. AIM: To study the activity of amylase, alkaline phosphatase and lipase in placenta and umbilical cord blood in women in labor with gestational diabetes mellitus in comparison with women without this pathology. METHODS: Cord blood and placenta sections were obtained from women with (n = 20) and without (n = 62) gestational diabetes mellitus during labor in the presence of informed consent. Alkaline phosphatase and lipase activity was estimated by kinetic colorimetric method, amylase activity by amyloclastic method according to Caraway. RESULTS: It has been shown that in pregnant women with gestational diabetes mellitus who are on diet therapy, significant differences in the activity of amylase and alkaline phosphatase are present in the homogenate of the placenta and umbilical cord blood compared with pregnant women without gestational diabetes mellitus. In pregnant women without gestational diabetes mellitus and women on insulin therapy, no significant differences were found in the studied fluids according to these enzymes. There were no significant differences in the lipolytic activity of umbilical cord blood and placental homogenate between the groups of women studied. CONCLUSION: The study showed that gestational diabetes mellitus in women leads to significant changes in the activity of enzymes in the homogenate of the placenta and umbilical cord blood.