Morphofunctional changes in the chief cells of the intrinsic glands of the stomach in the presence of an excess of glucocorticoid and sex hormones in the body

In 260 male white rats electron microscopically, cytochemically with biochemical estimation of proteolitic activity of gastric juice, it has been demonstrated that principle cells of the gastric glands, after injection of small doses of hydrocorticone, respond with a complex of adequate ultrastructural, cytochemical and functional changes directed to realization of the drugs stimulating effect. With increasing time of the experiment, or the doses, progressively developing distrophic processes, involving predominantly the protein-synthesizing apparatus and, to a less degree, the mitochondrial mechanism, are observed in the principle cells. This results in inhibition of the pepsinogene synthesis phase and in decreasing proteolytic activity of gastric juice. Reaction of the principle cells is independent on testosterone doses; the protein-synthesizing and mitochondrial (to a less degree) apparatuses develop; the pepsinogene extrusion phase is suppressed; it results in its deposition in cytoplasm and in decreasing proteolytic activity of gastric juice. When testosterone and hydrocortisone are injected simultaneously in small doses, the stimulating effect of hydrocortisone to the principle cells is abolished and at large doses it is sharply manifested and is not accompanied with destructive changes in the principle cells.     

Abscission: the role of ethylene, ethylene analogues, carbon dioxide, and oxygen

Ethylene was the most effective abscission accelerant examined, with decreasing activity shown by propene, carbon monoxide, acetylene, vinyl fluoride, 1-butene, and 1,3-butadiene. Carbon dioxide inhibited abscission, but its effect was overcome by ethylene. Oxygen was required for abscission as an electron acceptor for respiration and not as a potentiator or activator of the ethylene attachment site. The molecular requirements for abscission were similar to those shown by other workers for other biological processes under the influence of ethylene.     

From the light to the darkness: thriving at the light extremes in the oceans

Light-acclimation processes are central to allowing photosynthesis in aquatic ecosystems to span from high light conditions, that are 10-fold higher than the light levels required to saturate photosynthesis, to the deep sea with extremely low light levels. In dim light systems, nutrient levels are often high, and cells maximize the absorption of light by increasing the cellular pool of pigments. The upper limits of light absorption are constrained by the package effect, which ultimately restricts the benefit of the light absorption associated with an increase in cellular pigmentation, thus decreasing the cost/benefit ratio relative to the metabolic cost of manufacturing cellular light-harvesting pigments. At extremely low light levels in the deep sea, chloroplasts are sequestered in numerous organisms; however, these species are not obligate autotrophs and supplement a heterotrophic/mixotrophic existence with opportunistic autotrophy. While low light acclimation is based on maximizing light absorption, photosynthetic systems under high light, in addition to decreased light-harvesting cross sections, rely on energy-dissipation processes to avoid light-induced damage to the photosynthetic apparatus and other free radical susceptible cell structures. Dissipation of excess light energy represents the largest sink of the absorbed light in high light environments; however, these processes remain largely unstudied and are rarely quantified. Cells supplement their energy-dissipation processes through increasing the capacity to remove high-light-generated radicals and/or inducing vertical movement. Improved understanding of strategies remains central for the understanding of algal distributions in nature and has broad industrial implications.     

LPS inhibits caspase 3-dependent apoptosis in RAW264.7 macrophages induced by the AMPK activator AICAR

AMP-activated kinase is a cellular energy sensor which is activated in stages of increased ATP consumption. Its activation has been associated with a number of beneficial effects such as decreasing inflammatory processes and the disease progress of diabetes and obesity, respectively. Furthermore, AMPK activation has been linked with induction of cell cycle arrest and apoptosis in cancer and vascular cells, indicating that it might have a therapeutic impact for the treatment of cancer and atherosclerosis. However, the impact of AMPK on the proliferation of macrophages, which also play a key role in the formation of atherosclerotic plaques and in inflammatory processes, has not been focused so far. We have assessed the influence of AICAR- and metformin-induced AMPK activation on cell viability of macrophages with and without inflammatory stimulation, respectively. In cells without inflammatory stimulation, we found a strong induction of caspase 3-dependent apoptosis associated with decreased mTOR levels and increased expression of p21. Interestingly, these effects could be inhibited by co-stimulation with bacterial lipopolysaccharide (LPS) but not by other proinflammatory cytokines suggesting that AICAR induces apoptosis via AMPK in a TLR4-pathway dependent manner.     

Structural and functional characteristics of the lower tracheobronchial lymph nodes in the rat after administration of dimethyl sulfate

By means of microanatomical methods the inferior tracheobronchial lymph nodes in 36 Wistar rats have been investigated, when the animals have been subjected to the effect of dimethylsulfate (DMS) vapors. The effect of the substance in doses 0.1 and 2.0 mg/m3 for 2 and 14 days has been studied. Comparison of relative parameters of the structural components areas and the cytological profile of the lymph nodes has been performed. DMS effects for 2 and 14 days in the maximal tolerance concentration (MTC) results in increasing area of the connective tissue stroma and the cortical substance, in comparison with the control, as well as in decreasing area of the medulla substance. At the contact with DMS for 2 days (at a corresponding MTC) certain changes of the nodular cytological profile are noted. They demonstrate that to the given time of the experiment the adaptive processes in the lymph nodes have no time to develop completely. DMS effect for 14 days in the same concentration produces an increased destruction of cellular elements and inhibits the plasmocellular reaction intensity (in comparison to the control and the experiment for 2 days). DMS maximal concentration (2.0 mg/m3) results in decreasing area of the lymphoid noduli with germinative centers. Intensity of mitotic processes decreases and autoimmune processes develop.     

On the theory of apoptotic decrease of the cell volume

The dynamic model of membrane transport, which describes the changing of ion contents in the cell, cell volume and membrane potential, for the first time, is applied to analysis of the apoptotic processes. It is shown that increasing of permeability of K+, and Cl(-)-channels, decreasing of permeability of Na+ together with degradation of Na+/K+ pump, KCC and NC cotransporters lead to decreasing of cell U937 volume and plasma membrane depolarization at apoptosis induced by staurosporine in concentration 1 microM. The experimental data using at calculations was published in paper (Yurinskaya et al., 2010).     

雪被去除对川西高山森林冬季土壤温度及碳、氮、磷动态的影响

气候变暖导致的雪被动态格局变化可能深刻影响高山森林生态过程.为了解气候变暖背景下雪被的减少对川西高山森林土壤生态过程的影响,2009年10月19日-2010年5月18日,采用遮雪方法,研究了雪被去除对该区冷杉原始林土壤温度和碳、氮、磷的影响.结果表明:雪被去除加大了土温日变化幅度和冻融循环频次,使土壤冻结和融化时间提前.雪被去除使土壤可溶性碳和可溶性氮、有效磷、铵态氮和硝态氮冬季含量高峰提前到雪被覆盖期;雪被覆盖期至融化期的可溶性碳和氮及硝态氮含量增加,但有效磷和铵态氮含量降低,改变了其组分比例.气候变暖引起的川西高山森林雪被减少将改变土壤外部环境条件,进而影响土壤碳、氮和磷过程.     

Ontogeny of additive and maternal genetic effects: lessons from domestic mammals

Evolution of size and growth depends on heritable variation arising from additive and maternal genetic effects. Levels of heritable (and nonheritable) variation might change over ontogeny, increasing through "variance compounding" or decreasing through "compensatory growth." We test for these processes using a meta-analysis of age-specific weight traits in domestic ungulates. Generally, mean standardized variance components decrease with age, consistent with compensatory growth. Phenotypic convergence among adult sheep occurs through decreasing environmental and maternal genetic variation. Maternal variation similarly declines in cattle. Maternal genetic effects are thus reduced with age (both in absolute and relative terms). Significant trends in heritability (decreasing in cattle, increasing in sheep) result from declining maternal and environmental components rather than from changing additive variation. There was no evidence for increasing standardized variance components. Any compounding must therefore be masked by more important compensatory processes. While extrapolation of these patterns to processes in natural population is difficult, our results highlight the inadequacy of assuming constancy in genetic parameters over ontogeny. Negative covariance between direct and maternal genetic effects was common. Negative correlations with additive and maternal genetic variances indicate that antagonistic pleiotropy (between additive and maternal genetic effects) may maintain genetic variance and limit responses to selection.     

Decomposition rate of carrion is dependent on composition not abundance of the assemblages of insect scavengers

Environmental factors and biodiversity affect ecosystem processes. As environmental change modifies also biodiversity it is unclear whether direct effects of environmental factors on ecosystem processes are more important than indirect effects mediated by changes in biodiversity. High-quality resources like carrion occur as heterogeneous pulses of energy and nutrients. Consequently, the distribution of scavenging insects is related to resource availability. Therefore, carrion decomposition represents a suitable process from which to unravel direct effects of environmental change from indirect biodiversity-related effects on ecosystem processes. During three field seasons in 2010 we exposed traps baited with small-mammal carrion at 21 sites along a temperature gradient to explore the insect carrion fauna and decomposition rate in the Bohemian Forest, Germany. The abundance component of beetle and fly assemblages decreased with decreasing temperature. Independently, the composition component of both taxa changed with temperature and season. The change in the composition component of beetles depicted a loss of larger species at higher temperatures. Decomposition rate did not change directly along the temperature gradient but was directly influenced by season. The composition component of beetles, and to a small extent of flies, but not their abundance component, directly affected carrion decomposition. Consequently, lower decomposition rates at lower temperatures can be explained by the absence of larger beetle species. Thus, we predict that future environmental change will modify carrion fauna composition and thereby indirectly decomposition rate. Moreover, reorganizations of the insect carrion composition will directly translate into modified decomposition rates, with potential consequences for nutrient availability and carbon storage.     

Acidic pH amplifies iron-mediated lipid peroxidation in cells

The goal of our study was to investigate the mechanism by which changes in extracellular pH influence lipid peroxidation processes. Ferrous iron can react with hydroperoxides, via a Fenton-type reaction, to initiate free radical chain processes. Iron is more soluble at lower pH values, therefore we hypothesized that decreasing the environmental pH would lead to increased iron-mediated lipid peroxidation. We used Photofrin, a photosensitizer that produces singlet oxygen, to introduce lipid hydroperoxides into leukemia cells (HL-60, K-562, and L1210). Singlet oxygen reacts with the PUFA of cells producing lipid hydroperoxides. Using EPR spin trapping with POBN, free radical formation from HL-60 cells was only detected when Photofrin, light, and ferrous iron were present. Free radical formation increased with increasing iron concentration; in the absence of extracellular iron, radical formation was below the limit of detection and lipid hydroperoxides accumulated in the membrane. In the presence of iron, lipid-derived radical formation in cells is pH dependent; the lower the extracellular pH (7.5-5.5), the higher the free radical flux; the lower the pH, the greater the membrane permeability induced in K-562 cells, as determined by trypan blue dye exclusion. These data demonstrate that lipid peroxidation processes, mediated by iron, are enhanced with decreasing extracellular pH. Thus, acidic pH not only releases iron from "safe" sites, but this iron will also be more damaging.     

Morphocytochemical reaction of the main exocrinocytes of the proper gastric glands to orchiectomy

In the experiment performed on 52 white male rats by means of light and electron microscopy, cytochemistry and biochemistry, it has been stated that bilateral removal of the testes inhibits proliferation of epitheliocytes in the collum of the proper gastric glands and their differentiation into the main exocrinocytes. This results in decreasing amount of the latter and in development of certain destructive processes in them. They concern mainly the protein-synthesizing apparatus and to a less degree the mitochondrial and lysosomal apparatus. RNA content, ATPase activity oxidoreductase of Krebs cycle and pentose-phosphate shunt decreases, and that of glycolysis increase. Pepsinogen synthesis and its extrusion are inhibited; this is accompanied with a decreased proteolytic activity of the gastric juice. Regenerative processes in the main exocrinocytes are also inhibited.     

Vasotocin stimulates appetitive responses to the visual and pheromonal stimuli used by male roughskin newts during courtship

It is now well established that vasotocin (AVT) and its mammalian homologue vasopressin influence various social behaviors in vertebrates, but less is known about the mechanisms through which these peptides modulate behavior. In male roughskin newts, Taricha granulosa, AVT stimulates a courtship behavior, amplectic clasping. Three general explanations for how AVT affects male courtship behavior have been considered: by enhancing a central state of sexual motivation, by affecting sensorimotor integration mechanisms in individual sensory modalities, or by influencing a nonspecific state of attention, arousal, or anxiety. AVT administration enhanced appetitive responses to visual and olfactory sexual stimuli, as would be expected if AVT affects a state of sexual motivation that affects behavioral responses to sexual stimuli regardless of the sensory modality in which they are processed. However, AVT selectively enhanced responses to female olfactory stimuli (sex pheromones), but similarly enhanced responses to female and food-related visual stimuli (worms), thus questioning the utility of such a motivational mechanism, as responses to female stimuli were not selectively enhanced in all sensory modalities. We therefore propose that exogenous AVT independently influences olfactory processes associated with orientation/attraction toward a female sex pheromone and visual processes associated with orientation/attraction toward a visual feature common to females and worms. In further experiments AVT administration failed to stimulate feeding behavior but did decrease locomotor activity. Thus, AVT does not stimulate courtship behavior in this species by enhancing the animals' general state of attention or by decreasing general anxiety, as responses to nonsexual, attractive stimuli were not uniformly enhanced, nor by stimulating general arousal, as activity levels did not increase. Rather, the data support the conclusion that AVT affects courtship by influencing specific sensorimotor processes associated with behavioral responses to individual releasing stimuli, which suggests a mechanistic framework for understanding socially motivated behavior is this species.     

Testosterone as a factor modifying the toxicity of ekatin for the Pharaoh quail (Coturnix coturnix Pharaoh). I. Mature birds

1. Testosterone reduces the haemolytic action of Ekatin on the morphotic blood elements by accelerating maturation of erythroblastic cells. 2. Testosterone, by accelerating the metabolism of the pesticide causes a defective defence processes of the organism by decreasing the number of macrophages. 3. Intoxication of androgenised birds with Ekatin leads to a breakdown of the systemic adaptive mechanisms by rapid and early switching on the adrenal cortex in response to the stress caused by poisoning.     

Participation of peptide hydra morphogen in the regulation of proliferation processes in different tissues of white rats]

The PMH influence on proliferation processes in some tissues of white rats was studied. PMH injections in doses 10.0 mkg/kg and 100.0 mkg/kg stimulated the processes of DNA--synthesis after 24 hours in corneal and tongue epithelium. The direct dose-dependent effect was revealed. PMH in dose 10.0 mkg/kg activated the proliferative processes in the stomach epithelium and thymus cortex. after 24 hours too. The given dose of PMH caused trustworthy decreasing of proliferative activity in thymus after 4 hours. The stimulation of DNA-synthesis and acceleration of mitosis were found after 5-times application on white rat's corneal with 100 nM PMH solution.     

The survival of mice and the metallothionein content of their livers and kidneys as criteria for assessing exposure to pulsed neutron radiation

The effect of pulsed neutron radiation was studied in comparison with continuous neutron radiation and continuous gamma-radiation. Animal survival and induction of metallothionein (MT) synthesis in liver and kidney of mice exposed to equivalent doses were chosen as criteria for evaluation of radiation effects. It was found that the level of MT in liver and kidney of mice exposed to neutron radiation decreased 24 hours after irradiation and then continued decreasing in kidney for 48 hours after irradiation. This is evidence of more intensive free-radical processes initiated by pulsed neutron radiation. At the same time, RBE values of pulsed neutrons did not differ significantly from that of continuous neutron radiation.     

REGULATION OF GROWTH PROCESSES DURING THE CELL CYCLE OF THE CHLOROCOCCAL ALGA SCENEDESMUS QUADRICAUDA UNDER A DNA REPLICATION BLOCK

The kinetics of two growth parameters (total RNA and total protein accumulation) was followed in synchronized cultures of the chlorococcal alga Scenedesmus quadricauda ( Turp.) Bréb. under conditions of inhibited DNA replication in the presence of 5-fluorodeoxyuridine (25 mg.L^-1). In the control culture, growth processes occurred in several steps with a decreasing rate of accumulation of RNA and protein amount approximately at each doubled value of the preceding step. Oscillations in the rate of growth processes in the control culture were temporally related to the initiation of individual reproductive steps. At each doubling, the cell became committed to triggering a sequence of reproductive processes, starting with DNA replication and ending with protoplast fission. Three commitment points were attained in the control culture and, consequently, three replication rounds of DNA followed by three nuclear divisions and three protoplast fissions occurred during one cell cycle. If 5-fluorodeoxyuridine (FdUrd) was added at the beginning of the cell cycle, no reproductive processes occurred, and the cells remained uninuclear with one genome and did not divide. RNA accumulation did not seem to be affected by the presence of FdUrd for at least one cell cycle, and three or four doublings in the amount of RNA occurred during this period. Protein accumulation was even more independent of reproductive processes in the cell and continued for a period of about two or three cell cycles, attaining six doublings at the end of this period. Therefore, oscillations in the rate of protein or RNA accumulation remained even if reproductive processes were inhibited .     

The ultrastructure of the plasma membrane at the division furrow of grasshopper germ cells

Summary Evidence is provided from cinematography and electron microscopy that chemical processes are responsible for both plasma membrane synthesis and cell separation in dividing germ cells of the grasshopper. Polyribosome-like material is deposited as a ring equatorially, which determines the presumptive division plane. The material deposited at the division plane, in synergism with cytoplasmic material and existing plasma membrane, synthesizes the new plasma membrane. The polyribosome-like material polymerizes into helices, and as the coils of the helices tighten less surface becomes available for membrane synthesis. The decreasing rate of plasma membrane synthesis is the mechanism for cell separation. Thus, plasma membrane synthesis and cell separation occur simultaneously, directed by the same dynamic processes.Work supported under the auspices of the U. S. Atomic Energy Commission.     

Effects of thermal factors on the state of microcirculation of the small intestine in acute ischemia

The influence of normo- (38 degrees C), hyper- (42 degrees C) and hypothermia (20 degrees C) on microcirculatory disturbances caused by acute local ischemia of the small intestine was investigated with the help of biomicroscopy as well as morphological methods. Ischemia was modeled by ligation of the intestine look eventrated through the abdominal wall incision of a rat onto the microscope stage for 1 h. It was shown that hyperthermia intensified microcirculatory disorders and stimulated destructive processes in tissues and hypothermia promoting microcirculation and decreasing metabolism and restrained the development of these processes. Important peculiarity of the microvascular response to ischemia, hyper- and hypothermia was revealed: heterogeneity of the reaction of different parts of microvascular bed. Appropriate evaluation of the microcirculation state in such conditions can be obtained taking into account not only the qualitative character of microvascular reaction but also an extent of this reaction manifestation in different parts of microvascular bed.