Changes in the lungs in the early period of closed trauma of the thorax in rats

In experiments on rats it has been demonstrated that in the acute period of uninjured parts of the lungs periodic changes of protein, lipid and glucose concentrations developed. In uninjured parts of the lungs one can observe more concentration of lipids and in injured parts-more glucose. The changes of substrates, concentrations in the lungs are due to not only the changes of venous blood excess in the lungs, but are connected with metabolic changes in the cells of the injured and uninjured parts of the lungs. The metabolic changes in the lungs in the acute period of chest trauma influence the creation of such indices of gas exchange as PaCO2 and PACO2.     

Effects of anaerobic and aerobic exercises in athletes on the variation of the parameters of oxygen transport systems in different seasons of the year

Observations of the changes in the functional states of athletes of two specializations (wrestlers and skiers) carried out for four years are summarized. The effects of seasonal changes superimposed on adaptive changes caused by training are analyzed. Changes in the erythron reflecting the modulating effect of seasonal environmental changes on the state of the blood system have been found.     

Role of the substantia nigra in the behavioural-cardiovascular integration in the cat

Electrical stimulation of the substantia nigra elicited complex patterns of response composed of somatomotor and circulatory changes. Increase in blood pressure associated with acceleration in heart rate was consistently produced by substantia nigra stimulation both in conscious and in anaesthetized cats. The respiration was either accelerated or arrested by the stimulation. Also self-stimulation of the substantia nigra elicited pressor responses. Electrical stimulation of the nucleus of the tractus solitarius paired with self-stimulation of the substantia nigra, produced regular changes in the lever-pressing rate for self-stimulation. It is suggested that the substantia nigra is probably involved in the neural mechanisms coupling the circulatory changes with the somatomotor responses.     

Seasonal changes in the amount of carbohydrate and crude protein in the rhizome ofMiscanthus sacchariflorus

In the herbaceous perennials, seasonal changes in the amount of reserve substances play an important role in the production processes of whole plants. Mutohet al. (1968) indirectly estimated the amount of reserve substances stored in the rhizome ofMiscanthus sacchariflorus by measuring the bulk density of the rhizome, and found aarked seasonal changes. In the present study seasonal changes in the carbohydrate and crude protein content of the rhizome were determined and the results obtained were compared with the changes in the total amount of reserve substances estimated by means of changes in the bulk density. A good parallel seasonal relationship was confirmed between the amount of consumable carbohydrate determined chemically and the quantity of reserve substances estimated from the changes in bulk density. The total yields of carbohydrate and crude protein were ca. 75% of the available reserve substances estimated from the changes of bulk density for the old rhizomes and ca. 65% for the new rhizomes in the middle of December.     

Changes in the histostructure of functional activity of the immunocompetent organs in damaged portal blood supply of the liver

In CBA mice calibrated stenosis of the portal vein was produced. Liver and immunocompetent organs were morphologically analyzed. The total number of hemopoietic stem cells in the bone marrow was estimated by the colony-forming cells and in the spleen after immunization with sheep red cells by the plaque forming method. It is established that stenosis of the portal vein (on the average by 45% and 58%) produced the histostructural changes in the liver and in the immunocompetent organs. Expression of morphological changes depended on the time elapsed after operation and the degree of the portal vein stenosis. These changes were the most pronounced on the 16-17th day when stenosis of the portal vein was 58%. The character of the changes in the number of the hemopoietic stem cells in the bone marrow and in that of antibody-forming cells in the spleen depended on the degree of the liver damage. These changes increased with the degree of the liver histostructure damage. The maximal liver damage was accompanied by a decrease of these indices.     

The role of food quality and competition in shaping the seasonal cycle in the reproductive activity of the sycamore aphid

The hypothesis that seasonal changes in sycamore aphid,Drepanosiphum platanoidis (Schr.), recruitment are determined by changes in food quality and aphid population density was tested. There was no clear association between the reproductive activity of the sycamore aphid and the seasonal changes in specific amino acids or groups of amino acids in extracts of sycamore,Acer pseudoplatanus L., leaves. Seasonal changes in reproductive activity tracked the changes in total amino acids of the leaf tissue of the host, but with a short time delay. High numbers of adult aphids appeared to depress reproductive activity. A regression analysis of the results revealed that total amino acids the previous week and current numbers of adult aphids significantly affected sycamore aphid reproductive activity. The results of this analysis support the above hypothesis, that the marked seasonal changes in the total quantity of amino acids in sycamore leaves and intraspecific competition for this resource, through its effect on adult weight, shape the seasonal cycle in the reproductive activity of the sycamore aphid.     

Annual cycle of activity in the nucleus tuberis hypothalami and the pars tuberalis of the hypophysis in the frog Rana esculenta

Abstract

A very distinct annual cycle of activity, as judged from nuclear volume changes, has been found in glandular cells of the pars tuberalis of the hypophysis and neurons in the nucleus tuberis hypothalami of adult green frogs (Rana esculenta). The changes are very similar at both sites, a single maximum in April and a single minimum in September being observed. Ependymal tanycy tes of the region which was investigated showed only very moderate activity changes. No sex differences were found with regard to the character of the cycle and the amplitude of changes. Only quantitative differences in absolute nuclear volume were found between the two sexes.     

Experience in using correlation analysis for evaluating the synchronism of the fluctuations in the level of infectious morbidity in individual areas

The possibility of using correlation analysis for evaluating the synchronism of changes in infectious morbidity rate on different territories was studied. The study demonstrated that the intensity of correlative relationships was mainly influenced by the degree of manifestation and the direction of prolonged tendencies in the changes of infectious morbidity on the territories under study. The presence of prolonged pronounced tendencies towards growth or decrease in the compared curves characterizing prolonged morbidity dynamics was found to limit the use of correlation analysis for the evaluation of synchronism of changes in morbidity rate.     

Seasonal variation in the terpenes of the foliage of black spruce

The changes in the relative amounts of the mono- and sesquiterpenes of the volatile oil of the leaves, buds and twigs of black spruce were determined at various intervals throughout the year. Major changes take place in the young leaves just after bud burst until mid-summer. Upon maturing the same quantitative composition as that of the mature leaves is reached. The composition of the latter, as well as that of the twigs, shows only minor changes from bud burst to mid-summer and none during the rest of the year. In contrast, large relative quantitative changes take place in the bud oil throughout the year. The relative changes of santene, tricyclene, camphene, bornyl acetate and limonene in the new growth follow similar curves, but those of α-pinene, β-pinene, myrcene, car-3-ene and the sesquiterpenes differ considerably. The sesquiterpenes, and possibly myrcene, appear to be metabolized at least in part as the young leaves mature.     

Testosterone-dependent changes in vivo and in vitro in the structure of the renal glomeruli of the teleost Gasterosteus aculeatus L.

Summary During the reproductive period of the male stickleback, structural and functional changes of the kidney take place, both in the glomeruli and in the renal tubule cells. The structural changes in the glomeruli involve almost all glomerular components and point to a reduction of the glomerular filtration rate. The purpose of this study was to investigate whether these changes are controlled by testosterone, indirectly or directly. In vivo experiments demonstrated that exposure of immature castrates for 8 days to methyltestosterone leads to activation of mesangial cells and podocytes, to slight expansion of mesangial matrix and slight thickening of basal lamina. Observations on cultured renal tissue showed that two androgens, 11-ketotestosterone and methyl testosterone, are also able to stimulate the secretory activity of podocytes and mesangial cells in vitro. The results therefore indicate, that most glomerular changes in male sticklebacks during the reproductive season are directly effected by testosterone.     

Changes in the ultrastructure of synapses and neurons of the ventral horns of the spinal cord in cats with tetany as a result of the removal of the parathyroid glands

An electron microscopic investigation on ultrastructure of synapses and ventral horns of the lumbar thickening in the spinal cord of cats with parathyroprival tetany has been performed. When motor disorders are clearly seen on the 2d - 4th days after removal of the parathyroid glands, together with the changes demonstrating functional activity of the synapses, certain irreversible degenerative changes of the "dark" type are seen in the axodendritic and axosomatic synapses. A complex of structural-metabolic changes has been revealed in the motor neurons, they have both functional-compensatory and degenerative character. It is possible to suggest that the changes revealed at parathyroprival tetany result from a disturbed metabolism and increased afferent influences.     

Progress in the histomorphometry of the microcirculatory system

Following a short review of the limits set to the procedures applied so far to measure quantitative changes in wall tissue of microvessels, a new measuring method is presented. It detect morphological reactions of the microcirculatory system on the grounds of changes in the numerical density of selectively visualized microvessels and their classification according to the external diameter by means of the automatic microscopic image analysing system QUANTIMET. Influences of structurally based and/or postmortal changes of the lumen wideness on the measurement are excluded by the automatic subtraction of the lumen area.     

Evaluating the role of natural selection in the evolution of gene regulation

Surveys of gene expression reveal extensive variability both within and between a wide range of species. Compelling cases have been made for adaptive changes in gene regulation, but the proportion of expression divergence attributable to natural selection remains unclear. Distinguishing adaptive changes driven by positive selection from neutral divergence resulting from mutation and genetic drift is critical for understanding the evolution of gene expression. Here, we review the various methods that have been used to test for signs of selection in genomic expression data. We also discuss properties of regulatory systems relevant to neutral models of gene expression. Despite some potential caveats, published studies provide considerable evidence for adaptive changes in gene expression. Future challenges for studies of regulatory evolution will be to quantify the frequency of adaptive changes, identify the genetic basis of expression divergence and associate changes in gene expression with specific organismal phenotypes.     

Expression of the lipopolysaccharide receptors in the rat liver cells in inflammation and in norm

The liver can be a primary target organ for bacterial endotoxins--lipopolysaccharides, which serve as the major triggers of anaphylotoxin's generation. Both lipopolysaccharides and anaphylotoxins induce the acute-phase reaction in the liver. The acute-phase reaction comprises a variety of systemic changes. Synthesis of several plasma proteins in the liver and glucose output from hepatocytes undergo dramatic changes during inflammation. These changes are mediated by soluble factors. Mechanism of signal transduction is reviewed in detail. Attention is payed to the differences between expression of the lipopolysaccharide receptors under normal and inflammatory conditions.     

Climate-induced changes in the vegetation pattern of China in the 21st century

Quantifying climate-induced changes in vegetation patterns is essential to understanding land–climate interactions and ecosystem changes. In the present study, we estimated various distributional changes of vegetation under different climate-change scenarios in the 21st century. Both hypothetical scenarios and Hedley RCM scenarios show that the transitional vegetation types, such as shrubland and grassland, have higher sensitivity to climatic change compared to vegetation under extreme climatic conditions, such as the evergreen broadleaf forest or desert, barren lands. Mainly, the sensitive areas in China lie in the Tibetan Plateau, Yunnan-Guizhou Plateau, northeastern plain of China and eco-zones between different vegetations. As the temperature increases, mixed forests and deciduous broadleaf forests will shift towards northern China. Grassland, shrubland and wooded grassland will extend to southeastern China. The RCM-project climate changes generally have caused positive vegetation changes; vegetation cover will probably improve 19% relative to baseline, and the forest will expand to 8% relative to baseline, while the desert and bare ground will reduce by about 13%.     

Changes in the albumin content of mouse hepatocytes in vitro

Using the immunoenzyme method followed by the cytophotometrical analysis the dynamics of albumin content changes in isolated mouse hepatocytes in culture was studied. The data obtained point to cyclic changes of the albumin content in the liver cells with the 1 hour periodicity similar to the changes in the rate of protein synthesis revealed for the same cells.     

Light-induced Changes in the Conformation and Configuration of the Thylakoid Membrane of Ulva and Porphyra Chloroplasts in Vivo

The ultrastructural basis of light-induced transmission and light scattering changes of thalli of Ulva and Porphyra were investigated by high resolution electron microscopy and microdensitometry. The results show that upon illumination of dark thalli (a) a reduction in thickness of thylakoid membranes (conformational change), (b) a more regular ordering, and (c) flattening of the thylakoids (configurational changes) have occurred. An explanation for the observed conformational and configurational changes was proposed in terms of correlated changes in ionic environment and osmotic properties of chloroplasts in vivo which are initiated by photosynthetic reactions.     

Light-dependent changes in the enzyme activity of the ascorbate-glutathione cycle and ascorbate oxidase in the leaves of pea

Light-determined activation of ferments of ascorbate-glutation cycle, ascorbate-oxidase in chloroplasts and cytosol is demonstrated as well as ascorbate-peroxidase, monodehydroascorbate-reductase, glutation-reductase and ascorbate-oxydase in mitochondria. On the other hands activity of mitochondrial dehydroascorbate-reductase increased on reduction of light most likely due to function of electron transport from glutation to dehydroascorbate in mitochondria. Glutation metabolism is proved to be endogenic catalytic process where the amount reconstructed glutation changes slowly with a delay and gradually follow light changes. Light dependable changes of glutation content in chloroplasts ensure resistance of ferment system again hydrogen peroxide and superoxide radicals that generate intensively at light.     

Physical characteristics in the new model of the cerebrospinal fluid system

It is unknown which factors determine the changes in cerebrospinal fluid (CSF) pressure inside the craniospinal system during the changes of the body position. To test this, we have developed a new model of the CSF system, which by its biophysical characteristics and dimensions imitates the CSF system in cats. The results obtained on a model were compared to those in animals observed during changes of body position. A new model was constructed from two parts with different physical characteristics. The "cranial" part is developed from a plastic tube with unchangeable volume, while the "spinal" part is made of a rubber baloon, with modulus of elasticity similar to that of animal spinal dura. In upright position, in the "cranial" part of the model the negative pressure appears without any measurable changes in the fluid volume, while in "spinal" part the fluid pressure is positive. All of the observed changes are in accordance to the law of the fluid mechanics. Alterations of the CSF pressure in cats during the changes of the body position are not significantly different compared to those observed on our new model. This suggests that the CSF pressure changes are related to the fluid mechanics, and do not depend on CSF secretion and circulation. It seems that in all body positions the cranial volume of blood and CSF remains constant, which enables a good blood brain perfusion.     

Changes in histones and transcription in the nuclei of sympathetic neurons in rats of various ages under the action of testosterone

A study of chromatin in KSTG neurocytes revealed the most remarkable changes of template activity after testosterone administration in 9 days old rats and less significant changes in adult rats. No changes were detected in 19 days old rats. The pattern of silver staining of the nuclei did not differ from the control in all age groups. The possible role of testosterone in differentiation of KSTG neurocytes in early postnatal period as well as the stage-related differences in mechanisms of the hormone action during ontogenesis are discussed.