Morphofunctional changes in the rat's liver of different ages after L-methionine administration

Background: Literature data on the effect of methionine on functional activity and, especially, on morphological changes in the liver parenchyma in animals of different ages are sporadic, and research results are often ambiguous. Aim: The purpose of this work was to study and compare the morphofunctional changes in the liver of rats of different ages on prolonged administration of L-methionine. Material and Methods: The experiment was performed on 48 male Wistar rats of 3 and 15 months of age. Animals of the experimental group received L-methionine at a dose of 250 mg/kg body weight in addition to the standard diet, daily for 21 days. Histological preparations were prepared from liver tissue by a standard technique. Morphometry was performed on digital images using the computer program «Image J». Succinate dehydrogenase activity and protein concentration were determined in the suspension of hepatocyte mitochondria. Results: It was revealed that 21-day administration of L-methionine to rats led to hypertrophy of the hepatocyte nucleus, an increase in the nuclear-cytoplasmic ratio, the number of binuclear hepatocytes, and the nucleolus in the cell nucleus. The relative area of ​​the sinusoids network increased by 50% in 3-month-old animals. This indicated a better blood filling of the liver parenchyma. The increase in succinate dehydrogenase activity and protein concentration was revealed in the suspension of hepatocyte mitochondria of the experimental rats. This indicated an increase in the mitochondria energy potential and protein-synthetic activity. Conclusions: The administration of prophylactic doses of methionine to healthy rats leads to the appearance of pronounced morphological and functional signs of increased activity of hepatocytes. The severity of this effect has a distinct age-dependent character. In young rats, it is more pronounced than in mature rats. The results of the study are important for practical medicine when using methionine for therapeutic and prophylactic purposes

Effect of intermittent normobaric hypoxia on the morphological changes in the respiratory part of lungs in different seasons of the year

The purpose of this work was to study and compare the effect of intermittent normobaric hypoxia on the morphological and biochemical indices of the functional state and structure of the respiratory part of the lungs in the spring and autumn. The experimental rats were daily exposed to hypoxic gas mixture (12% oxygen in nitrogen) in intermittent mode: 15 minutes deoxygenation / 15 minutes reoxygenation for 2 hours. The duration of the experiment was 28 days. The histological preparations were made by the standard methods. The slides were photographed using a digital camera on the microscope «Nikon» (Japan). The morphometric analysis was performed on digital images with using the computer program "Image J". In the lung tissue was determined the concentration of total hydroxyproline and lipids. The results of our studies showed the seasonal differences in the effect of intermittent normobaric hypoxia on the morpho-functional state of respiratory part of the lungs. It can be related to the features of its activity in the spring and autumn. In spring, during a period of lesser activity of respiratory part of the lung, prolonged exposure to intermittent normobaric hypoxia slightly increases its functional activity. But in autumn, during a period of greater activity, it decreases. Thus, the use of intermittent normobaric hypoxia makes it possible to smooth seasonal differences in respiratory part of the lung activity

Estimates of the global burden of ambient PM2.5, ozone, and NO2 on asthma incidence and emergency room visits

Abstract Background: Asthma is the most prevalent chronic respiratory disease worldwide, affecting 358 million people in 2015. Ambient air pollution exacerbates asthma among populations around the world and may also contribute to new-onset asthma. Objectives: We aimed to estimate the number of asthma emergency room visits and new onset asthma cases globally attributable to fine particulate matter (PM2.5), ozone, and nitrogen dioxide (NO2) concentrations. Methods: We used epidemiological health impact functions combined with data describing population, baseline asthma incidence and prevalence, and pollutant concentrations. We constructed a new dataset of national and regional emergency room visit rates among people with asthma using published survey data. Results: We estimated that 9–23 million and 5–10 million annual asthma emergency room visits globally in 2015 could be attributable to ozone and PM2.5, respectively, representing 8–20% and 4–9% of the annual number of global visits, respectively. The range reflects the application of central risk estimates from different epidemiological meta-analyses. Anthropogenic emissions were responsible for ∼37% and 73% of ozone and PM2.5 impacts, respectively. Remaining impacts were attributable to naturally occurring ozone precursor emissions (e.g., from vegetation, lightning) and PM2.5 (e.g., dust, sea salt), though several of these sources are also influenced by humans. The largest impacts were estimated in China and India. Conclusions: These findings estimate the magnitude of the global asthma burden that could be avoided by reducing ambient air pollution. We also identified key uncertainties and data limitations to be addressed to enable refined estimation. https://doi.org/10.1289/EHP376

Morphofunctional state of the lungs respiratory part in normotensive and hypertensive rats after combined exposure to intermittent hypoxia and melatonin

Aim. The purpose of this work was to study and compare the combined effect of intermittent normobaric hypoxia (INH) and melatonin on the morphological and biochemical indices of the lungs respiratory part in Wistar and spontaneous hypertensive rats (SHR). Material and methods. The studies were conducted on 48 young male rats Wistar and SHR lines. The experimental rats were daily exposed to hypoxic gas mixture (12 % oxygen in nitrogen) in intermittent mode: 15 min deoxygenation / 15 min reoxygenation for 2 hours. Animals also received oral melatonin at a dose of 5 mg /1 kg of body weight once daily.Results. The sizes of alveolus were reduced, but their number and placement density were increased in SHR rats after a combined effect of INH and melatonin. The results showed a significant decrease of the interalveolar septum thickness and a tendency to decrease of the hydroxyproline concentration in the lung tissue of the experimental rats, regardless of their line.Conclusions. The 28-day combined effect of INH and melatonin increase the total alveolar surface area and reduce the amount of connective tissue in the lungs of experimental rats. These changes can improve the efficiency of the intrapulmonary gas exchange processes. </p

Seasonal features of the combined effects of intermittent normobabic hypoxia and melatonin on the thyroid gland morphofunctional state

The aim of this work is to compare the effect of the combination influence of dosed intermittent normobaric hypoxia and melatonin in different seasons of the year on the morphofunctional state of the rats’ thyroid gland.Material and methods. The study was carried out on 48 male rats of the Wistar line. The hypoxic gas mixture (12% O2 and 88% N2) was daily given to experimental animals in intermittent mode: 15 minutes deoxygenation / 15 minutes reoxygenation for 2 hours. Melatonin was administered orally in a dose of 5 mg / kg at10.00 a.m. The total duration of the experiment was 28 days. Histological preparations were prepared according to a standard methodic. Histomorphometry of the digital images of preparations was carried out using the computer program «Image J».Results. It was shown that the thyroid gland of rats reacted differently to the combined effects of intermittent hypoxia and melatonin at different seasons. So the signs of the gland activity were increased after influence of hypoxia and melatonin in spring. It was evidenced by a smaller area of follicles and colloid, a smaller internal diameter of the follicles and colloid-accumulation index, a greater height of the thyrocytes and follicular-colloid index, a smaller width of the interlobar, interlobular and interfollicular connective tissue interlayers compared to the control. The prolonged exposure to intermittent hypoxia and melatonin in autumn decreased the area and height of the follicular epithelium, increased the internal diameter of the follicles, decreased the follicular-colloidal index and increased the colloid-accumulation index. This indicated a decrease in the activity of the thyroid gland.Conclusions. Thus, in the spring, the morphofunctional activity of the thyroid gland is moderately increased, and in the autumn period, on the contrary, decreases.</p

Polarimetric Reverberation Mapping in Medium-Band Filters

Earlier, we suggested the “reload” concept of the polarimetric reverberation mapping of active galactic nuclei (AGN), proposed for the first time more than 10 years ago. We have successfully tested this approach of reverberation mapping of the broad emission line on the galaxy Mrk 6. It was shown that such an idea allows one to look at the AGN central parsec structure literally in a new light. However, the method originally assumed the use of spectropolarimetric observations, expensive in terms of telescope time, and implemented on rare large telescopes. Currently, we propose an adaptation of the polarimetric reverberation mapping of broad lines in medium-band filters following the idea of the photometric reverberation mapping, when filters are selected so that their bandwidth is oriented to the broad line and the surrounding continuum near. In this paper, we present the progress status of such monitoring conducted jointly at the Special astrophysical observatory and Asiago Cima Ekar observatory (OAPd/INAF) with support from Rozhen National Astronomical Observatory (NAO), some first results for the most frequently observed AGNs Mrk 335, Mrk 509, and Mrk 817, and the discussion of the future perspectives of the campaign