Coupled evolution of digestive, respiratory, circulatory, and excretory systems: a model investigation

A model is developed of evolution of an organism with digestive, respiratory, circulatory, and excretory systems at the single system. The model is realized on the basis of the language STELLA 8.0. A balance is found between perfection of each individual physiological system and necessary energy expenditures for survival of the organism as a whole. The model is based on a coupled development of several visceral systems. There is analyzed effect of a change of consumption of substances with food and of oxygen amount on their oxidation, a branching of blood flow to organs, specifically to kidneys, to excrete final products of metabolism from blood. The energy expenditures for circulation are believed to be proportional to blood flow in a given organ. An increase of efficiency of renal excretion from blood of final metabolic products and toxic substances has a favorable effect on inner medium and activity of each cell of an individual, but increases of the organism energy expenditures. Interrelation of these factors under conditions of adaptation to changing environmental conditions determines peculiarities of evolution of each physiological system in an individual.     

A study into the anti-microbial properties of an amino functionalised polymer using multi-parameter flow cytometry

Fluorescent staining techniques were used to study the anti-microbial properties of aqueous suspensions of a novel, water insoluble amino functionalised polymer on three micro-organisms Pseudomonas fluorescens, Staphylococcus epidermidis and Saccharomyses cerevisiae. The mechanism of action was similar for each organism in that, after various contact times with the polymer, a progressive change in individual cell physiological state was measured using multi-parameter flow cytometry. The microbiocidal activity of this polymer may be similar to that of substances referred to as polycationic, amphipathic compounds (peptides, peptide derivatives and other polyamines).     

A model for the age-dependent dynamics of growth of terrestrial mammals

Two hypothetical biological mechanisms were proposed that largely determine the dynamics of growth of overland mammals. The first mechanism is the maintenance of a spatial similarity of the anatomy of the organism during its growth, and the second is the maintenance of the stability of the internal environment of the organism. On the basis of the advanced hypothesis, a model of age-dependent dynamics of growth was constructed, and a differential equation describing the changes in the body mass with time was derived. According to this model, the dynamics of growth and the mass of an adult individual are determined by two energy constants that characterize the mechanism of food assimilation and the energy expenditures for the movement of the individual in space. The deviation between the solution obtained and the experimental data on age-dependent changes in the mass of the human body was on the average 6%. These insignificant deviations were explained in the framework of the proposed hypothesis, which indicates its validity.     

Leptin, a neuroendocrine mediator of immune responses, inflammation, and sickness behaviors

This article is part of a Special Issue "Neuroendocrine-Immune Axis in Health and Disease." Effective immune responses are coordinated by interactions among the nervous, endocrine, and immune systems. Mounting immune, inflammatory, and sickness responses requires substantial energetic investments, and as such, an organism may need to balance energy allocation to these processes with the energetic demands of other competing physiological systems. The metabolic hormone leptin appears to be mediating trade-offs between the immune system and other physiological systems through its actions on immune cells and the brain. Here we review the evidence in both mammalian and non-mammalian vertebrates that suggests leptin is involved in regulating immune responses, inflammation, and sickness behaviors. Leptin has also been implicated in the regulation of seasonal immune responses, including sickness; however, the precise physiological mechanisms remain unclear. Thus, we discuss recent data in support of leptin as a mediator of seasonal sickness responses and provide a theoretical model that outlines how seasonal cues, leptin, and proinflammatory cytokines may interact to coordinate seasonal immune and sickness responses.     

Clinical oxidation parameters of aging

Aging is a complex progressive physiological alteration of the organism which ultimately leads to death. During the whole life a human being is confronted with oxidative stress. To measure how this oxidative stress is developing during the aging process and how it changes the cellular metabolism several substances have been pronounced as biomarkers including lipid peroxidation (LPO) products, protein oxidation products, antioxidative acting enzymes, minerals, vitamins, glutathione, flavonoids, bilirubin and uric acid (UA).

But none of them could develop to the leading one which is accepted by the whole scientific community to determine the life expectancy of the individual person or biological age or age-related health status. Further there are many conflicting data about the changes of each single biomarker during the aging process.

There are so many different influences acting on the concentration or activity of single substances or single enzymes that it is not possible to measure only one clinical marker and determine how healthy an individual is or to predict the life expectancy of the corresponding person. Therefore, always a set or pattern of clinical biomarkers should be used to determine the oxidation status of the person. This set should include at least one marker for the LPO, the protein oxidation and the total antioxidative status and ideally also one for DNA damages.     

Clinical oxidation parameters of aging

Aging is a complex progressive physiological alteration of the organism which ultimately leads to death. During the whole life a human being is confronted with oxidative stress. To measure how this oxidative stress is developing during the aging process and how it changes the cellular metabolism several substances have been pronounced as biomarkers including lipid peroxidation (LPO) products, protein oxidation products, antioxidative acting enzymes, minerals, vitamins, glutathione, flavonoids, bilirubin and uric acid (UA).

But none of them could develop to the leading one which is accepted by the whole scientific community to determine the life expectancy of the individual person or biological age or age-related health status. Further there are many conflicting data about the changes of each single biomarker during the aging process.

There are so many different influences acting on the concentration or activity of single substances or single enzymes that it is not possible to measure only one clinical marker and determine how healthy an individual is or to predict the life expectancy of the corresponding person. Therefore, always a set or pattern of clinical biomarkers should be used to determine the oxidation status of the person. This set should include at least one marker for the LPO, the protein oxidation and the total antioxidative status and ideally also one for DNA damages.     

An essay on the evolution of cognition: Constructing a theoretical conceptual framework

In this essay we provide an interdisciplinary approach to the problem of the evolution of human cognition and suggest the theoretical framework of genetic system theory (GST) for organizing the relevant content of several disciplines. This bio-social-cultural theory is based on the assumption that organisms are dynamic systems which interact with one another and their environment and are themselves composed of dynamic internal relations at several levels. Special emphasis will be placed upon these internal cellular and molecular mechanisms underlying the physiological mechanisms of learning and memory. The human individual organism is emphasized because in its experiential activity over time it is the site of integration for social, and cultural stimuli and because of its unique properties among living things. The primary disciplines for our discussion are drawn from the biological, social, and humanistic sciences and several concrete examples are given from each science.     

Biology, ecology, and biotechnological applications of anaerobic bacteria adapted to environmental stresses in temperature, pH, salinity, or substrates.

Anaerobic bacteria include diverse species that can grow at environmental extremes of temperature, pH, salinity, substrate toxicity, or available free energy. The first evolved archaebacterial and eubacterial species appear to have been anaerobes adapted to high temperatures. Thermoanaerobes and their stable enzymes have served as model systems for basic and applied studies of microbial cellulose and starch degradation, methanogenesis, ethanologenesis, acetogenesis, autotrophic CO2 fixation, saccharidases, hydrogenases, and alcohol dehydrogenases. Anaerobes, unlike aerobes, appear to have evolved more energy-conserving mechanisms for physiological adaptation to environmental stresses such as novel enzyme activities and stabilities and novel membrane lipid compositions and functions. Anaerobic syntrophs do not have similar aerobic bacterial counterparts. The metabolic end products of syntrophs are potent thermodynamic inhibitors of energy conservation mechanisms, and they require coordinated consumption by a second partner organism for species growth. Anaerobes adapted to environmental stresses and their enzymes have biotechnological applications in organic waste treatment systems and chemical and fuel production systems based on biomass-derived substrates or syngas. These kinds of anaerobes have only recently been examined by biologists, and considerably more study is required before they are fully appreciated by science and technology.     

Quantum processes in evolution of regulation of living system (mathematical modelling)

We have developed an imitation model of the appearance of regulation of physiological functions of protocell at the initial stages of evolution of living system. It is based on suggestion of the appearance of signal function in spontaneously formed products of partial hydrolysis of the protocell polypeptides, based on which there appear the regulatory molecules--quanta of regulation. For construction of the model, the mathematical apparatus of final automats and of genetic algorithm is used. The model has demonstrated the positive role of involvement of regulatory peptides in the system of regulation of protocell functions to provide its viability under the changing envelopment conditions.     

Evolution of endocrine glands and neuroendocrine systems: the "humoral code"

Origin of complex neuroendocrine systems in evolution seems to be based on the signalling functions of molecules produced by separate groups of cells and glands, and each of these molecules "is coding" some distinct conditions of internal milieu and environment for the cell and the whole organism. Use of such "coding" molecules for the integration of the separate glands in the neuroendocrine systems permits to guaranty supply of vital substances to the organism regardless of external and internal disrupting circumstances, and to retain ability to alter the levels of the hormones produced by these systems in accordance with changes in internal milieu and environment.     

Quantum processes in evolution of regulation of living systems (mathematical modeling)

We have developed an imitation model of the appearance of regulation of physiological functions of protocell at initial stages of evolution of living system. It is based on suggestion of the appearance of signal function in spontaneously formed products of partial hydrolysis of the protocell polypeptides, based on which there appear the regulatory molecules—quanta of regulation. For construction of the model, the mathematical apparatus of final automats and of genetic algorithm is used. The model has demonstrated the positive role of involvement of regulatory peptides in the system of regulation of protocell functions to provide its viability under the changing envelopment conditions.     

Regulatory role of heparin compounds with low molecular ligands of blood in plasma and thromocyte hemostasis

Aanalysis of the literature and our own research on the physiological effects of complex compounds of heparin with low molecular ligands (amino acids, regulatory peptides) is presented. It is proved that anticoagulative effects in blood flow were conditioned by the interaction of heparin with glioproline, immunopeptides, and other low molecular substances with formation of complex compounds. The presence of structural regions of binding of heparin and other components is established. It is indicated that in the blood of animals heparin complexes with low molecular ligands possess protective anticoagulative and antithrombotic effects. We made an attempt to reveal the possible mechanism of anticoagulative-fibrinolytic and antithrombotic action of complex compounds of heparin in the organism.     

What is an organism? An immunological answer

The question, "What is an organism?," formerly considered as essential in biology, has now been increasingly replaced by a larger question, "What is a biological individual?" On the grounds that i) individuation is theory-dependent, and ii) physiology does not offer a theory, biologists and philosophers of biology have claimed that it is the theory of evolution by natural selection that tells us what counts as a biological individual. Here I show that one physiological field, immunology, offers a theory that makes possible a biological individuation based on physiological grounds. I give a new answer to the question of the individuation of an organism by linking together the evolutionary and the immunological approaches to biological individuation.     

Genetic-evolutionary basis of symbiosis doctrine

The author presents the current notion of symbiosis as one of the main adaptation of an organism to changeable environment. Symbiosis is considered as a super organism genetic system within which there are different interactions (including mutualism and antagonism). Genetic integration of symbiotic partners can be realized as cross regulation of their genes, exchange of gene products (proteins, RNA), gene amplification and sometimes gene transfer between organisms. On the phenotypic level these processes result in signal interactions, integration of partner metabolic systems and development of symbiotic organs. Co-evolution is considered as an assemblage of micro- and macroevolution processes basing on pre-adaptations and proceeding under influence of different forms of natural selection (individual, frequency-depended and kin selection). Symbiosis can be compared with sexual process since both are the forms of organism integration characterized by different genetic mechanisms and evolutionary consequences. The genome evolution in symbiotic microorganisms can proceed by: 1) simplification of genome in obligate symbiosis (loss of genes that are necessary for independent existence, transfer of some genes to the host organism); 2) complication of genome in facultative symbiosis (increase in genome plasticity, structural and functional differentiation of genome into systems controlling free-living and symbiotic parts of life cycle). Most of symbiotic interactions are correlated to an increase in genetic plasticity of an organism that can lead to evolutionary saltations and origin of new forms of life.     

Specific features in realization of the principle of minimum energy dissipation during individual development

Realization of the principle of minimum energy dissipation (Prigogine??s theorem) during individual development has been analyzed. This analysis has suggested the following reformulation of this principle for living objects: when environmental conditions are constant, the living system evolves to a current steady state in such a way that the difference between entropy production and entropy flow (?? _u function) is positive and constantly decreases near the steady state, approaching zero. In turn, the current steady state tends to a final steady state in such a way that the difference between the specific entropy productions in an organism and its environment tends to be minimal. In general, individual development completely agrees with the law of entropy increase (second law of thermodynamics).     

Hormones and the levels of humoral regulation]

The problems on the place of hormones secreted by "classical" endocrine glands, on their relationship with other compounds that possess physiological activity, criteria that determine the definition "hormone" are considered in this article. The conception about the levels of the humoral regulatory systems that are organized and formed during phylogenesis and ontogenesis and provide a consecutive increase in their complexity and mobility of adaptation to changes of environment and internal conditions are substantiated on the basis of numerous data. The metabolites that are products of nonspecific activity of any cell of the multicellular organism form the first and simplest level of humoral regulatory organization. The next (second) level of humoral organization is also formed by chemically simple substances. However, these substances are specialized products of the secretory activity of cells and exert potent influence on the physiological processes. Neuroamines and regulatory peptides are applied to these agents, in the first place. They arise simultaneously and jointly at the first stage of ontogenesis. The distinctive characters of the third level of the humoral regulation are increased and complication of the regulatory activity conditioned by cooperative influences of humoral agents produced by single secretory elements situated outside the classical endocrine glands. The chemically and originally different substances causing predominantly local effects are attributed to these physiologically active substances. Their participation in general adaptive reactions as well as inclusion of classical hormones into hierarchy of humoral regulation signify the formation of the forth regulatory level that provides realization of general homeostatic reactions peculiar to the whole organism.(ABSTRACT TRUNCATED AT 250 WORDS)     

Gravitation biology using fish as model systems for understanding motion sickness susceptibility

During the entire evolution of life on Earth, the development of all organisms took place under constant gravity conditions, against which they achieved specific countermeasures for compensation and adaptation. On this background, it is still an open question to which extent altered gravity such as hyper- or microgravity (centrifuge/spaceflight) affects the normal individual development, either on the systemic level of the whole organism or on the level of individual organs or even single cells. The present short review provides information on this topic, focusing on the effects of altered gravity on developing fish as model systems even for higher vertebrates including humans, with special emphasis on the effect of altered gravity on behaviour and particularly on the developing brain and vestibular system.     

A novel mouse-driven ex vivo flow chamber for the study of leukocyte and platelet function

Various in vitro and in vivo techniques exist for study of the microcirculation. Whereas in vivo systems impress with their physiological fidelity, in vitro systems excel in the amount of reduction that can be achieved. Here we introduce the autoperfused ex vivo flow chamber designed to study murine leukocytes and platelets under well-defined hemodynamic conditions. In our model, the murine heart continuously drives the blood flow through the chamber, providing a wide range of physiological shear rates. We used a balance of force approach to quantify the prevailing forces at the chamber walls. Numerical simulations show the flow characteristics in the chamber based on a shear-thinning fluid model. We demonstrate specific rolling of wild-type leukocytes on immobilized P-selectin, abolished by a blocking MAb. When uncoated, the surfaces having a constant shear rate supported individual platelet rolling, whereas on areas showing a rapid drop in shear platelets interacted in previously unreported grapelike conglomerates, suggesting an influence of shear rate on the type of platelet interaction. In summary, the ex vivo chamber amounts to an external vessel connecting the arterial and venous systems of a live mouse. This method combines the strengths of existing in vivo and in vitro systems in the study of leukocyte and platelet function. autoperfused flow chamber; intravital microscopy; inflammation; thrombus formation     

General equilibrium of an ecosystem

Ecosystems and economies are inextricably linked: ecosystem models and economic models are not linked. Consequently, using either type of model to design policies for preserving ecosystems or improving economic performance omits important information. Improved policies would follow from a model that links the systems and accounts for the mutual feedbacks by recognizing how key ecosystem variables influence key economic variables, and vice versa. Because general equilibrium economic models already are widely used for policy making, the approach used here is to develop a general equilibrium ecosystem model which captures salient biological functions and which can be integrated with extant economic models. In the ecosystem model, each organism is assumed to be a net energy maximizer that must exert energy to capture biomass from other organisms. The exerted energies are the "prices" that are paid to biomass, and each organism takes the prices as signals over which it has no control. The maximization problem yields the organism's demand for and supply of biomass to other organisms as functions of the prices. The demands and supplies for each biomass are aggregated over all organisms in each species which establishes biomass markets wherein biomass prices are determined. A short-run equilibrium is established when all organisms are maximizing and demand equals supply in every biomass market. If a species exhibits positive (negative) net energy in equilibrium, its population increases (decreases) and a new equilibrium follows. The demand and supply forces in the biomass markets drive each species toward zero stored energy and a long-run equilibrium. Population adjustments are not based on typical Lotka-Volterra differential equations in which one entire population adjusts to another entire population thereby masking organism behavior; instead, individual organism behavior is central to population adjustments. Numerical simulations use a marine food web in Alaska to illustrate the model and to show several simultaneous predator/prey relationships, prey switching by the top predator, and energy flows through the web.