A partial carcass of an adult woolly mammoth (Mammuthus primigenius) found in 2012 on Maly Lyakhovsky Island presents a new opportunity to retrieve associated anatomical, morphological, and life history data on this important component of Pleistocene biotas. In addition, we address hematological, histological, and microbiological issues that relate directly to quality of preservation. Recovered by staff from North-Eastern Federal University in Yakutsk, this individual is a relatively old female preserving soft tissue of the anteroventral portion of the head, most of both fore-quarters, and the ventral aspect of much of the rest of the body. Both tusks were recovered and subjected to computed tomographic analysis in which annual dentin increments were revealed as cycles of variation in X-ray attenuation. Measurements of annual increment areas (in longitudinal section) display a pulsed pattern of tusk growth showing cycles of growth rate variation over periods of 3e5 years. These intervals are interpreted as calving cycles reflecting regular shifts in calcium and phosphate demand for tusk growth vs. fetal ossification and lactation. Brown liquid associated with the frozen carcass turned out to include remains of hemolyzed blood, and blood samples examined microscopically included white blood cells with preserved nuclei. Muscle tissue from the trunk was unusually well preserved, even at the histological level. Intestinal contents and tissue samples were investigated microbiologically, and several strains of lacticacid bacteria (e.g., Enterococcus faecium, Enterococcus hirae) that are widely distributed as commensal organisms in the intestines of herbivores were isolated.
The thymus is the central organ of the immunogenesis, the functioning of which determines the protective reactions of the organism. Various stressors can influence the immune organs. One of these factors is exposure to low temperatures. The aim of this research was studying the effect of experimental cold stress on the morphological and functional state of rat thymus using morphometric analysis. The cold exposure was done by placing the rats in individual cages in a refrigeration chamber at a temperature of -10 ± 20 °C for 1 hour at the same time of day for 7, 14, 21, and 30 days. Histological examination of thymus preparations stained with hematoxylin and eosin; on the 7th day after exposure to cold, the area of the cortical substance is significantly reduced compared with the control group, while the area of the medulla tends to increase. Analysis of the cell composition showed an increase in the number of epithelia-reticular cells in the subcapsular zone and a slight decrease in the number of lymphocytes. On the 14th day of exposure, the areas of cortical and medulla and the cortical-cerebral index do not differ from the indicators of intact control. Morphometric counting of cellular elements showed an increase in the number of lymphocytes, epithelia-reticulocytes, and macrophages. After 21 days of the experiment, data on the relative areas of cortical and medulla shows a significant decrease in the rate compared with all the first groups. The counting of cellular elements during this period showed marked changes observed in all morphological and functional zones of the thymus. In the subcapsular zone, there is a sharp decrease in the number of dividing lymphocytes. The number of epithelia-reticular cells is increased relative to the norm. There is frequent detection of apoptotic bodies and fat cells. In the medulla, there is an increase in the number of epithelia-reticulocytes compared with the 7th and 14th day. On the 30th day after exposure, the areas of cortical, medulla, and cortical-cerebral index remained at the same level as on the 21st day. There is a significant decrease in epithelia-reticular cells in the subcapsular zone, a significant decrease in the cortical substance and the cortico-medullary zone compared with all groups, and a significant increase in their number in the medulla. Hassall’s bodies are characterized by pronounced degenerative changes in epithelia-reticulocytes with cellular debris. In the subcapsular zone, a reduced number of cells with mitosis figures is maintained. It was established that as a result of cold stress on days 7, 21 and 30, there is a redistribution of volume and cellular composition, various structural and functional zones, indicating a decrease in the functional activity of the thymus, an increase in the death of lymphocytes by apoptosis, a decrease in mitotic activity, and accumulation of macrophages. Morphological and functional data of the 14th day of the experiment indicate the development of compensatory-adaptive changes in the thymus on the cold effect, manifested in the form of activation of cell division in the cortical substance and the cortical-medullary zone.
The aim of this study was to assess the anthropometric and physiometric indicators with an analysis of the body composition of young Yakuts of early and late puberty, living in the Republic of Sakha (Yakutia) (RS(Y)). Materials and Methods: A total of 184 indigenous youths aged from 14 to 17 years, permanently residing in RS(Y), were examined. The study used generally accepted methods: anthropometry, dynamometry, spirometry, caliperometry, and body composition assessment by bioelectrical impedance analysis. Results: Among Yakut youth living in RS(Y), an increase in musculoskeletal mass and a decrease in fat mass was observed in groups aged 14 to 17. In the period from 14 to 17 years, Yakut youth show significantly increased indicators of dynamometry, deadlift and vital lung capacity. The data above are accompanied by a decrease in the indicators of the content of fat mass and an increase in lean body mass, musculoskeletal mass and body cell mass. There is growth not only in skeletal muscles and skeleton, but also in the mass of internal organs. The data obtained will be used to develop an interval classification of body composition parameters for males of different ages in order to develop standards of physical development specifically for people living in RS(Y).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.