The Participation of the Organism Adaptation Mechanisms to the Lack of Oxygen According to the Assessment of the Fethemoglobin Content in the Peripheral Blood of Patients with Community-acquired Pneumonia

Introduction. Сommunity-acquired pneumonia (COP) is a global socio-medical problem. At emergence of pneumonia by any genesis, hypoxia develops. Oxygen homeostasis of the body is provided by the coordinated interaction of external respiration, circulatory system and oxygen-transport system of the blood. Hypoxia, due to the malfunction of the external respiratory system, causes the formation of compensatory changes, in the implementation of which involved components of the oxygen transport system. Molecular genetic mechanisms play an important role in the body's adaptation to oxygen deficiency. Fetal hemoglobin (FetHb), having an increased affinity for oxygen, makes a significant contribution to the body's adaptation to new conditions with altered gaseous environment in the presence of pathological processes occurring with hypoxia. In this regard, it is interest to determine FetHb in adults with COP to study its effect on the diagnosis, prognosis and outcome of the disease. The aim of the study. To determinate the participation of the organism adaptation mechanisms to the lack of oxygen according to the assessment of the content of fetal hemoglobin in the peripheral blood of patients with community-acquired pneumonia. Materials and methods. We examined 34 adult patients (18 women and 16 men) with COP, aged 18 to 80 years, who were in the therapeutic department of the City Clinical Hospital № 25 in Kharkiv. The control group was formed of 20 healthy individuals. Spirography was performed on the diagnostic complex "Valenta"; hematological examinations – on the analyzer "ADVIA 60"; measurement of pO2 and pCO2, oxygen saturation, content of fetal hemoglobin – on the device "RAPIDLAB865". Results. In patients with community-acquired pneumonia, there was a decrease of the ventilatory function of external respiration, which is confirmed by a marked decrease in partial oxygen pressure. Oxygen saturation of blood was reduced in the group of patients with COP, but the difference was not statistically significant 94.8 ± 1.0 %. This indicates the presence of compensatory mechanisms aimed at maintaining adequate blood oxygen saturation. Significant increase in pH (from 7.40 to 7.53) and decrease in standard bicarbonate (from 1.27 to 0.68 mmol/l) resulting from violation of the gas composition of the blood can be regarded as a manifestation of partially compensated respiratory alkalosis. In patients with COP, there was a reduction in the total time of hemolysis, a shift of the maximum erythrogram to the left and an increase in the maximum itself, indicating a sharp decline in erythrocyte resistance. The proportion of erythrocytes with reduced resistance was twice as large as similar forms in the control group and the number of highly resistant cells in patients with COP sharply decreased. Obviously, oxygen starvation-mediated stress erythropoiesis is accompanied by the entry into the circulation of functionally defective erythrocytes. They are subject to accelerated elimination from the vascular bed, which causes a decrease in the quantitative indicators of red blood (erythrocyte content, hemoglobin) while maintaining corpuscular parameters (Mean Corpuscular Volume, Mean Cell Hemoglobin Concentration). At the same time, the analysis of individual hemoglobin fractions revealed an increase in the proportion of fetal hemoglobin (from 2.90 ± 0.31 % in the group of healthy individuals to 5.43 ± 1.05 % in patients with COP) (p less than 0.05). Conclusions. Changes in the parameters of acid hemolysis, fetal hemoglobin in the peripheral blood of patients with community-acquired pneumonia with impaired pulmonary ventilation function indicate their participation in the mechanisms of adaptation to oxygen deficiency and they have informative potential. Elevated fetal hemoglobin in peripheral blood in these patients can be used as an indicator of hypoxia, accompanied by impaired oxygen delivery to tissues, which should be used as an additional criterion for diagnosing tissue hypoxia and justify the timely appointment of antihypoxia drugs. Keywords: hypoxia, community-acquired pneumonia, red blood cells, fetal hemoglobin.

Oxygen Dependence of Flight Performance in Ageing Drosophila melanogaster

Similar to humans, insects lose their physical and physiological capacities with age, which makes them a convenient study system for human ageing. Although insects have an efficient oxygen-transport system, we know little about how their flight capacity changes with age and environmental oxygen conditions. We measured two types of locomotor performance in ageing Drosophila melanogaster flies: the frequency of wing beats and the capacity to climb vertical surfaces. Flight performance was measured under normoxia and hypoxia. As anticipated, ageing flies showed systematic deterioration of climbing performance, and low oxygen impeded flight performance. Against predictions, flight performance did not deteriorate with age, and younger and older flies showed similar levels of tolerance to low oxygen during flight. We suggest that among different insect locomotory activities, flight performance deteriorates slowly with age, which is surprising, given that insect flight is one of the most energy-demanding activities in animals. Apparently, the superior capacity of insects to rapidly deliver oxygen to flight muscles remains little altered by ageing, but we showed that insects can become oxygen limited in habitats with a poor oxygen supply (e.g., those at high elevations) during highly oxygen-demanding activities such as flight.

Primary and secondary aerenchyma oxygen transportation pathways of Syzygium kunstleri (King) Bahadur & R. C. Gaur adventitious roots in hypoxic conditions

Some plant species develop aerenchyma to avoid anaerobic environments. In Syzygium kunstleri (King) Bahadur & R. C. Gaur, both primary and secondary aerenchyma were observed in adventitious roots under hypoxic conditions. We clarified the function of and relationship between primary and secondary aerenchyma. To understand the function of primary and secondary aerenchyma in adventitious roots, we measured changes in primary and secondary aerenchyma partial pressure of oxygen (pO2) after injecting nitrogen (N2) into the stem 0–3 cm above the water surface using Clark-type oxygen microelectrodes. Following N2 injection, a decrease in pO2 was observed in the primary aerenchyma, secondary aerenchyma, and rhizosphere. Oxygen concentration in the primary aerenchyma, secondary aerenchyma, and rhizosphere also decreased after the secondary aerenchyma was removed from near the root base. The primary and secondary aerenchyma are involved in oxygen transport, and in adventitious roots, they participate in the longitudinal movement of oxygen from the root base to root tip. As cortex collapse occurs from secondary growth, the secondary aerenchyma may support or replace the primary aerenchyma as the main oxygen transport system under hypoxic conditions.

A DIFFERENTIATED APPROACH TO INFUSION-TRANSFUSION THERAPY FOR LARGE BLOOD LOSS IN PATIENTS WITH POLYTRAUMA

With polytrauma, more than 30% of victims are diagnosed with severe blood loss, grade III MARINO of the leading components is transfusion therapy, which aims to restore the erythron system and improve the functional state of the oxygen transport system. The addition to intensive care of substances that affect lipid peroxidation and energy status of cells can reduce the number of heterogeneous transfusions and thus reduce the number of complications in the postoperative period. Such substances may be a solution of ceruloplasmin with a leading antioxidant effect and a solution of D-fructose-1,6-diphosphate sodium salt of the hydrate with an energetic effect. Criteria for exposure to these substances should be indicators such as blood levels of hemoglobin, phosphorus, malonic dialdehyde and lactate / pyruvate ratio.

SEASONAL DYNAMICS OF ENDOCRINE REGULATION OF METABOLIC RATE, BLOOD OXYGEN TRANSPORT SYSTEM AND PHYSICAL PERFORMANCE OF MIDDLE OB REGION ATHLETES FROM CYCLIC WINTER SPORTS

Aim. The paper aims to study the seasonal dynamics of endocrine regulation of metabolic rate, blood oxygen transport system and physical performance of Middle Ob region athletes from cyclic winter sports. Materials and methods. A comprehensive two-stage study of the endocrine system, blood oxygen transport system and physical performance was carried out among elite cross country skiers and biathletes aged from 15 to 18 years during the periods of the year with pronounced daylight variability. The research methods included enzyme-linked immunoassay (ELISA) with the measurements of total triiodothyronine, total thyroxine, thyroid-stimulating hormone, total testosterone and growth hormone; analysis of peripheral blood with the measurements of red blood cells, hemoglobin, hematocrit and red blood cell indices; cardiopulmonary exercise testing with ergospirometry and assessment of maximum oxygen consumption, physical work capacity, oxygen pulse and anaerobic threshold. Results. Statistical analysis revealed significant (p < 0.05) seasonal changes in the endocrine system, blood oxygen transport system and physical performance of Middle Ob region athletes. Namely, during the short daylight period there was a significant increase in total triiodothyronine and cortisol, a decrease in total testosterone, red blood cells, hemoglobin, hematocrit and the average volume of red blood cells, an increase in absolute and relative values of maximum oxygen consumption, oxygen pulse, physical work capacity and a decrease in anaerobic threshold. Conclusion. The results of the research characterize the features of athletes’ adaptation to specific climatic factors of the Northern region against the background of intense physical exertion.

Developmental constraint shaped genome evolution and erythrocyte loss in Antarctic fishes following paleoclimate change

In the frigid, oxygen-rich Southern Ocean (SO), Antarctic icefishes (Channichthyidae; Notothenioidei) evolved the ability to survive without producing erythrocytes and hemoglobin, the oxygen-transport system of virtually all vertebrates. Here, we integrate paleoclimate records with an extensive phylogenomic dataset of notothenioid fishes to understand the evolution of trait loss associated with climate change. In contrast to buoyancy adaptations in this clade, we find relaxed selection on the genetic regions controlling erythropoiesis evolved only after sustained cooling in the SO. This pattern is seen not only within icefishes but also occurred independently in other high-latitude notothenioids. We show that one species of the red-blooded dragonfish clade evolved a spherocytic anemia that phenocopies human patients with this disease via orthologous mutations. The genomic imprint of SO climate change is biased toward erythrocyte-associated conserved noncoding elements (CNEs) rather than to coding regions, which are largely preserved through pleiotropy. The drift in CNEs is specifically enriched near genes that are preferentially expressed late in erythropoiesis. Furthermore, we find that the hematopoietic marrow of icefish species retained proerythroblasts, which indicates that early erythroid development remains intact. Our results provide a framework for understanding the interactions between development and the genome in shaping the response of species to climate change.