Stress, chemocommunication, and the physiological hypothesis of mutation

The review considers stress as a physiological state of the organism, affecting the cellular, genomic, and population levels. Literature data and cytogenetic studies by the author support basic statements of the physiological hypothesis of mutation, which was advanced as early as in the 1940s. Studies of pheromonal effects in germline and somatic cells of the house mouse demonstrated the role of olfactory stressors in generating genetic variation in microevolutionary changes.     

Interrelationships among whole-body coordination, functional potentiality, and environmental adaptability

The term "adaptability" or "capacity of adaptation" is the central concept in the general advancement and promotion of research in physiological anthropology. Throughout the history of Homo sapiens, mankind has adapted itself to environmental stress. As a result, numerous physiological polymorphisms in humans are present in our planet-wide distribution. Totally regulated physiological function by integration and coordination is referred to as whole-body coordination and is associated with a high degree of adaptability in humans. Functional potentiality also affects environmental adaptability. Thus, whole-body coordination and functional potentiality are necessary for adaptation to environmental changes. There is an interrelationship among functional potentiality, whole-body coordination, physiological polymorphisms, and environmental adaptability.     

Differentiation of Gram-Negative, Nonfermentative Bacteria Isolated from Biofilters on the Basis of Fatty Acid Composition, Quinone System, and Physiological Reaction Profiles

Gram-negative, nonfermentative bacteria isolated from biofilters for off-gas treatment of animal-rendering-plant emissions were differentiated by whole-cell fatty acid analysis, quinone analysis, and numerical taxonomy based on their physiological reaction profiles. The last system consisted of 60 physiological tests and was arranged as a microtest system on microtitration plates. Based on fatty acid analyses, 31 isolates were separated into six clusters and five single-member clusters. The isolates of two clusters were identified as Alcaligenes faecalis and Pseudomonas diminuta. The remaining nine clusters were characterized by their fatty acid profiles, quinone systems, and physiological reaction profiles. Clusters resulting from fatty acid analyses were compared with those resulting from physiological reaction profiles. Six clusters could be confirmed this way. The efficiency of the physiological test system was increased by the prearrangement of the isolates according to their quinone type.     

Field Studies of Photosynthesis as Affected by Water Stress, Temperature, and Light in Birch

This study continues the investigations previously conducted as laboratory experiments. The results from the present study confirm our earlier observations made on alder seedlings concerning the effect of water stress, temperature and light on the net uptake of CO₂. A variable that we could call the physiological water stress is proposed as a measure of the intrinsic factor of photosynthesis during and after drought. A physiological water stress builds up and discharges slowly and interacts strongly with temperature. Our model for the effects of physiological water stress, temperature, and light intensity explains satisfactorily the net uptake of CO₂ in birch in the field. Thus, our earlier results concerning the effects of physiological water stress on photosynthesis are not artifacts generated by the unnatural laboratory environment.     

Plasticity in the timing of physiological development: physiological heterokairy--what is it, how frequent is it, and does it matter?

The study of developmental sequences of physiological traits could be an important way of placing comparative developmental physiology (CDP) within the research agenda being forged by work on developmental plasticity. Here we focus on the concept of heterokairy defined by Spicer & Burggren in 2003 as changes in the timing of physiological development in an individual. The role of this concept in the future of the CDP is discussed. First we provide an historical perspective of the ideas that have led to the investigation of sequences in CDP. This is followed by a re-examination and clarification of the definition of physiological heterokairy before empirical case studies that (explicitly or implicitly) demonstrate physiological heterokairy are reviewed. We suggest that physiological heterokairy can be demonstrated through a wide range of invertebrate and vertebrate examples. However, care must be taken when inferring that heterokairy as a pattern is always the result of heterokairic processes as there is evidence that physiological heterokairy could result from the altered timing of both homologous or analogous physiological mechanisms. We conclude by discussing the potential link between heterokairy and heterochrony and suggest that the investigation of this link should be a major goal for workers in both CDP and developmental plasticity.     

Relationships among negative life events, physiological reactivity, and health symptomatology

College undergraduates classified as high (n = 25) and low (n = 25) on recent life stress participated in an experiment involving a novel laboratory stressor. Heart rate and pulse arrival time (PAT) were measured during baseline, anticipation, testing, and recovery periods of the experiment. The results did not replicate those obtained by Pardine and Napoli in that high and low life stress subjects did not show differential physiological reactions. In addition, regression analyses failed to demonstrate that physiological reactivity moderated the relationship between life stress and subsequent self-reported psychiatric or physical health symptomatology. The present findings demonstrated neither the stress-buffering effects of physiological reactivity nor a relationship between life stress and reactivity when the latter was conceptualized as an outcome.     

Gonadotropin hormone modulation of testosterone, immune function, performance, and behavioral trade-offs among male morphs of the lizard Uta stansburiana

Sexual selection predicts that trade-offs maintain trait variation in alternative reproductive strategies. Experiments often focus on testosterone (T), but the gonadotropins follicle-stimulating hormone and luteinizing hormone may provide a clearer understanding of the pleiotropic relationships among traits. We assess the activational role of gonadotropins on T and corticosterone regulation in traits expressed by polymorphic male side-blotched lizards Uta stansburiana. Gonadotropins are found to enhance and suppress multiple physiological, morphological, and behavioral traits independently, as well as indirectly via T, and we demonstrate selective trade-offs between reproduction and survival. The OBY locus, a genetic marker in our model vertebrate mating system, allows characterization of the interaction between genotype and hormone treatment on male traits. Our results suggest that oo, ob, and bb males are near their physiological and behavioral capacity for reproductive success, whereas yy and by males are maintained below their physiological maximum. Both by and yy morphs show trait plasticity, and we demonstrate that gonadotropins are likely proximate effectors that govern not only trait differences between alternative mating strategies but also morph plasticity. Gonadotropins clearly represent an important mechanism maintaining variation in physiological, morphological, and behavioral traits, as well as potentially maintaining the immunosuppression costs of male sexual signals.     

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.     

Reptilian viviparity: past research, future directions, and appropriate models

Squamate reptiles represent an ideal group for studies of viviparity, because they have evolved this reproductive pattern frequently, relatively recently, and at low taxonomic levels. A phylogenetic approach shows particular promise in helping us interpret anatomical, physiological, and ecological diversity. This review summarizes four major categories of active investigation: (1) reproductive anatomy and physiology; (2) placental structure and function; (3) reproductive endocrinology; and (4) reproductive and physiological ecology. Evolutionary reconstructions suggest that on many occasions viviparity has evolved concomitantly with functional placentation, through reduction of the shell membrane and hormonal modifications that prolong gestation. Studies of placentotrophic clades as well as reproductively bimodal species offer great potential for explaining the evolution of viviparity and placentation. However, live-bearing squamates are reproductively diverse, and appear to have solved physiological problems associated with viviparity by a variety of mechanisms. Consequently, studies on one or a few squamate species appear increasingly unlikely to yield all-inclusive explanations. Future studies and analyses should abandon assumptions of universal physiological mechanisms and a single historical sequence, in favor of the documentation of diversity in phylogenetic and quantitative terms.     

Structural,physiological, and biochemical aspects of salinity tolerance of halophytes

Modern concepts on structural, physiological, and biochemical aspects of salt tolerance of higher plants were considered. Integral physiological processes, such as growth and photosynthesis of glycophytes and halophytes in the context of their ecological plasticity, variety of their adaptive strategies developed in the course of their evolution, and natural selection, were discussed. Analysis of the known anatomical and morphological adaptations of halophytes (succulence, special salt-excreting structures, features associated with special tissues growth, leaf kranz-anatomy and mesostructure) providing their salt tolerance was conducted. The most important physiological and biochemical adaptations of such plants to salinity related to uptake, accumulation and excretion of Na⁺ and Cl^–, peculiarities of membrane composition and the pigment system, and protection against osmotic and oxidative stresses were described. The association of physiological and biochemical peculiarities of halophytes with ecological salt tolerance strategy was discussed.     

Plasticity in the timing of physiological development: Physiological heterokairy — What is it, how frequent is it, and does it matter?

The study of developmental sequences of physiological traits could be an important way of placing comparative developmental physiology (CDP) within the research agenda being forged by work on developmental plasticity. Here we focus on the concept of heterokairy defined by Spicer & Burggren in 2003 as changes in the timing of physiological development in an individual. The role of this concept in the future of the CDP is discussed. First we provide an historical perspective of the ideas that have led to the investigation of sequences in CDP. This is followed by a re-examination and clarification of the definition of physiological heterokairy before empirical case studies that (explicitly or implicitly) demonstrate physiological heterokairy are reviewed. We suggest that physiological heterokairy can be demonstrated through a wide range of invertebrate and vertebrate examples. However, care must be taken when inferring that heterokairy as a pattern is always the result of heterokairic processes as there is evidence that physiological heterokairy could result from the altered timing of both homologous or analogous physiological mechanisms. We conclude by discussing the potential link between heterokairy and heterochrony and suggest that the investigation of this link should be a major goal for workers in both CDP and developmental plasticity.     

Cultural, morphological, and physiological characteristics of Thermomonospora fusca (strain 190Th).

The cultural, morphological, and physiological properties of Thermomonospora fusca (strain 190Th) are described. Its physiological properties show that this species is primarily a carbohydrate-degrading actinomycete which can use a wide range of plant sugars and polymeric carbohydrates as sources of carbon and energy. The culture does not use proteins or amino acids for carbon and energy, or as a nitrogen source. A few organic acids are utilized. Ammonia is the preferred nitrogen source. The culture has trace nutrient requirements which include biotin and an undetermined number of amino acids. These and other physiological characteristics are discussed in relation to the roles that T. fusca carries out as a saprophytic bacterium in nature. Its cultural and morphological properties are discussed in relation to the taxonomic status of this species in the literature.     

Synergistic and Antagonistic Effects of Thermal Shock,Air Exposure,and Fishing Capture on the Physiological Stress of Squilla mantis (Stomatopoda)

This study is aimed at assessing the effects of multiple stressors (thermal shock, fishing capture, and exposure to air) on the benthic stomatopod Squilla mantis, a burrowing crustacean quite widespread in the Mediterranean Sea. Laboratory analyses were carried out to explore the physiological impairment onset over time, based on emersion and thermal shocks, on farmed individuals. Parallel field-based studies were carried out to also investigate the role of fishing (i.e., otter trawling) in inducing physiological imbalance in different seasonal conditions. The dynamics of physiological recovery from physiological disruption were also studied. Physiological stress was assessed by analysing hemolymph metabolites (L-Lactate, D-glucose, ammonia, and H⁺), as well as glycogen concentration in muscle tissues. The experiments were carried out according to a factorial scheme considering the three factors (thermal shock, fishing capture, and exposure to air) at two fixed levels in order to explore possible synergistic, additive, or antagonistic effects among factors. Additive effects on physiological parameters were mainly detected when the three factors interacted together while synergistic effects were found as effect of the combination of two factors. This finding highlights that the physiological adaptive and maladaptive processes induced by the stressors result in a dynamic response that may encounter physiological limits when high stress levels are sustained. Thus, a further increase in the physiological parameters due to synergies cannot be reached. Moreover, when critical limits are encountered, mortality occurs and physiological parameters reflect the response of the last survivors. In the light of our mortality studies, thermal shock and exposure to air have the main effect on the survival of S. mantis only on trawled individuals, while lab-farmed individuals did not show any mortality during exposure to air until after 2 hours.     

Mechanisms,malfunctions and explanation in medicine

Mechanisms are a way of explaining how biological phenomena work rather than why single elements of biological systems are there. However, mechanisms are usually described as physiological entities, and little or no attention is paid to malfunction as an independent theoretical concept. On the other hand, malfunction is the main focus of interest of applied sciences such as medicine. In this paper I argue that malfunctions are parts of pathological mechanisms, which should be considered separate theoretical entities, conceptually having a priority over physiological sequences. While pathological mechanisms can be described in terms of a Cummins-like mechanistic explanation, they show some unnoticed peculiarities when compared to physiological ones. Some features of pathological mechanisms are considered, such as outcome variability, ambivalence and dependence on a range.     

GPI-AP release in cellular,developmental, and reproductive biology

Glycosylphosphatidylinositol-anchored proteins (GPI-APs) contain a covalently linked GPI anchor located on outer cell membranes. GPI-APs are ubiquitously conserved from protozoa to vertebrates and are critical for physiological events such as development, immunity, and neurogenesis in vertebrates. Both membrane-anchored and soluble GPI-APs play a role in regulating their protein conformation and functional properties. Several pathways mediate the release of GPI-APs from the plasma membrane by vesiculation or cleavage. Phospholipases and putative substrate-specific GPI-AP-releasing enzymes, such as NOTUM, glycerophosphodiesterase 2, and angiotensin-converting enzyme, have been characterized in mammals. Here, the protein modifications resulting from the cleavage of the GPI anchor are discussed in the context of its physiological functions.     

Protein phosphorylation: hormones, drugs, and bioregulation

Reversible protein phosphorylation is widely recognized as an important mechanism for the regulation of cell function by a variety of physiological stimuli. Exposure of cells to hormones, neurotransmitters, and growth factors initiates a cascade of events facilitated by intracellular second messengers and mediated in many cases by protein kinases and/or phosphatases. The subsequent covalent modification of target proteins and the associated changes in their function account for the physiological response. Considerable evidence points to cross-talk between multiple membrane-associated signaling processes leading to coordinated regulation of cellular processes. The role of protein phosphorylation at multiple points in the pathways that integrate these signals is becoming increasingly apparent. Pharmacological modulation of cellular protein phosphorylation has yielded useful information on the molecular events involved. This review surveys some of the recent progress in hormonal regulation of cell function, focusing on examples that may provide new insight into the role of protein phosphorylation in the coordinated control of cellular processes by physiological stimuli.     

Redox-based regulation of signal transduction: principles, pitfalls, and promises

Oxidants are produced as a by-product of aerobic metabolism, and organisms ranging from prokaryotes to mammals have evolved with an elaborate and redundant complement of antioxidant defenses to confer protection against oxidative insults. Compelling data now exist demonstrating that oxidants are used in physiological settings as signaling molecules with important regulatory functions controlling cell division, migration, contraction, and mediator production. These physiological functions are carried out in an exquisitely regulated and compartmentalized manner by mild oxidants, through subtle oxidative events that involve targeted amino acids in proteins. The precise understanding of the physiological relevance of redox signal transduction has been hampered by the lack of specificity of reagents and the need for chemical derivatization to visualize reversible oxidations. In addition, it is difficult to measure these subtle oxidation events in vivo. This article reviews some of the recent findings that illuminate the significance of redox signaling and exciting future perspectives. We also attempt to highlight some of the current pitfalls and the approaches needed to advance this important area of biochemical and biomedical research.     

Science, sentience, and animal welfare

I sketch briefly some of the more influential theories concerned with the moral status of nonhuman animals, highlighting their biological/physiological aspects. I then survey the most prominent empirical research on the physiological and cognitive capacities of nonhuman animals, focusing primarily on sentience, but looking also at a few other morally relevant capacities such as self-awareness, memory, and mindreading. Lastly, I discuss two examples of current animal welfare policy, namely, animals used in industrialized food production and in scientific research. I argue that even the most progressive current welfare policies lag behind, are ignorant of, or arbitrarily disregard the science on sentience and cognition.     

饥饿胁迫对小鼠学习记忆、SOD和心肌丙二醛的影响

给小鼠断绝食物,观察小鼠学习记忆能力的变化及生理应激反应。结果表明,饥饿后小鼠的体重明显减轻,学习能力明显增强,记忆能力和大脑5－羟色胺含量无明显改变,心肌丙二醛含量下降,肝组织超氧化物歧化酶（SOD）活性无明显改变,血浆SOD活性提高,血浆SOD同工酶变带无明显改变。提示饥饿胁迫使小鼠产生适应性的生理反应,使小鼠学习能力提高,加强延缓机体衰退的生理功能;这些应激反应有利于小鼠在逆境下的生存。     

Nitrite,a Reactive Nitrogen Species,Protects Human Alpha-2-Macroglobulin from Halogenated Oxidant,HOCl

Reactive nitrogen species have been implicated in the pathogenesis of over 40 human diseases, including inflammation. Evidences suggest that reactive nitrogen species such as nitrite/nitrate and halogenated oxidant-HOCl accumulate at the site of inflammation. At physiologically attainable concentrations, HOCl was found to significantly damage the antiproteolytic potential of human α₂M and induce subtle changes in conformation as judged by fluorescence analysis. Our studies further suggest that at physiological concentrations, nitrite offered significant protection against HOCl induced α₂M inactivation. Our studies suggest that nitrite may act as an antioxidant at physiological concentrations by removing HOCl at sites where both NO₂ and HOCl are formed.