major physiological functions: Topics by Science.gov

Sample records for major physiological functions

Physiology Applied to Everyday: The Practice of Professional Contextualization of Physiology Concepts as a Way of Facilitating Learning

ERIC Educational Resources Information Center

Borges, Sidnei; Mello-Carpes, Pâmela Billig

2014-01-01

The teaching of Physiology is indispensable in many biological and health disciplines. Physiology is one of the major components of the curriculum in a number of life science courses, including the study of life, cells, tissues, and organisms as well as their functions. A bigger challenge for physiology teachers is to make physiological concepts…
Clinical Physiology: A Successful Academic and Clinical Discipline is Threatened in Sweden

ERIC Educational Resources Information Center

Arheden, Hakan

2009-01-01

Clinical physiologists in Sweden are physicians (the majority with a PhD degree) with thorough training in system physiology and pathophysiology. They investigate patients in a functional approach and are engaged in basic and applied physiology teaching and research. In 1954, clinical physiology was founded as an independent academic and clinical…
Update in TSH Receptor Agonists and Antagonists

PubMed Central

Neumann, Susanne

2012-01-01

The physiological role of the TSH receptor (TSHR) as a major regulator of thyroid function is well understood, but TSHRs are also expressed in multiple normal extrathyroidal tissues, and the physiological roles of TSHRs in these tissues are unclear. Moreover, TSHRs play a major role in several pathological conditions including hyperthyroidism, hypothyroidism, and thyroid tumors. Small molecule, “drug-like” TSHR agonists, neutral antagonists, and inverse agonists may be useful as probes of TSHR function in extrathyroidal tissues and as leads to develop drugs for several diseases of the thyroid. In this Update, we review the most recent findings regarding the development and use of these small molecule TSHR ligands. PMID:23019348
A review of thermoregulation and physiological performance in reptiles: what is the role of phenotypic flexibility?

PubMed

Seebacher, Frank

2005-10-01

Biological functions are dependent on the temperature of the organism. Animals may respond to fluctuation in the thermal environment by regulating their body temperature and by modifying physiological and biochemical rates. Phenotypic flexibility (reversible phenotypic plasticity, acclimation, or acclimatisation in rate functions occurs in all major taxonomic groups and may be considered as an ancestral condition. Within the Reptilia, representatives from all major groups show phenotypic flexibility in response to long-term or chronic changes in the thermal environment. Acclimation or acclimatisation in reptiles are most commonly assessed by measuring whole animal responses such as oxygen consumption, but whole animal responses are comprised of variation in individual traits such as enzyme activities, hormone expression, and cardiovascular functions. The challenge now lies in connecting the changes in the components to the functioning of the whole animal and its fitness. Experimental designs in research on reptilian thermal physiology should incorporate the capacity for reversible phenotypic plasticity as a null-hypothesis, because the significance of differential body temperature-performance relationships (thermal reaction norms) between individuals, populations, or species cannot be assessed without testing that null-hypothesis.
Major component analysis of dynamic networks of physiologic organ interactions

NASA Astrophysics Data System (ADS)

Liu, Kang K. L.; Bartsch, Ronny P.; Ma, Qianli D. Y.; Ivanov, Plamen Ch

2015-09-01

The human organism is a complex network of interconnected organ systems, where the behavior of one system affects the dynamics of other systems. Identifying and quantifying dynamical networks of diverse physiologic systems under varied conditions is a challenge due to the complexity in the output dynamics of the individual systems and the transient and nonlinear characteristics of their coupling. We introduce a novel computational method based on the concept of time delay stability and major component analysis to investigate how organ systems interact as a network to coordinate their functions. We analyze a large database of continuously recorded multi-channel physiologic signals from healthy young subjects during night-time sleep. We identify a network of dynamic interactions between key physiologic systems in the human organism. Further, we find that each physiologic state is characterized by a distinct network structure with different relative contribution from individual organ systems to the global network dynamics. Specifically, we observe a gradual decrease in the strength of coupling of heart and respiration to the rest of the network with transition from wake to deep sleep, and in contrast, an increased relative contribution to network dynamics from chin and leg muscle tone and eye movement, demonstrating a robust association between network topology and physiologic function.
Sex-specific influences of mtDNA mitotype and diet on mitochondrial functions and physiological traits in Drosophila melanogaster

PubMed Central

Aw, Wen C.; Garvin, Michael R.; Melvin, Richard G.

2017-01-01

Here we determine the sex-specific influence of mtDNA type (mitotype) and diet on mitochondrial functions and physiology in two Drosophila melanogaster lines. In many species, males and females differ in aspects of their energy production. These sex-specific influences may be caused by differences in evolutionary history and physiological functions. We predicted the influence of mtDNA mutations should be stronger in males than females as a result of the organelle’s maternal mode of inheritance in the majority of metazoans. In contrast, we predicted the influence of diet would be greater in females due to higher metabolic flexibility. We included four diets that differed in their protein: carbohydrate (P:C) ratios as they are the two-major energy-yielding macronutrients in the fly diet. We assayed four mitochondrial function traits (Complex I oxidative phosphorylation, reactive oxygen species production, superoxide dismutase activity, and mtDNA copy number) and four physiological traits (fecundity, longevity, lipid content, and starvation resistance). Traits were assayed at 11 d and 25 d of age. Consistent with predictions we observe that the mitotype influenced males more than females supporting the hypothesis of a sex-specific selective sieve in the mitochondrial genome caused by the maternal inheritance of mitochondria. Also, consistent with predictions, we found that the diet influenced females more than males. PMID:29166659
Dietary fiber type reflects physiological functionality: comparison of grain fiber, inulin, and polydextrose.

PubMed

Raninen, Kaisa; Lappi, Jenni; Mykkänen, Hannu; Poutanen, Kaisa

2011-01-01

Dietary fiber is a nutritional concept based not on physiological functions but on defined chemical and physical properties. Recent definitions of dietary fiber differentiate inherent plant cell wall-associated fiber from isolated or synthetic fiber. For the latter to be defined as fiber, beneficial physiological effects should be demonstrated, such as laxative effects, fermentability, attenuation of blood cholesterol levels, or postprandial glucose response. Grain fibers are a major natural source of dietary fiber worldwide, while inulin, a soluble indigestible fructose polymer isolated from chicory, and polydextrose, a synthetic indigestible glucose polymer, have more simple structures. Inulin and polydextrose show many of the same functionalities of grain fiber in the large intestine, in that they are fermentable, bifidogenic, and laxative. The reported effects on postprandial blood glucose and fasting cholesterol levels have been modest, but grain fibers also show variable effects. New biomarkers are needed to link the physiological functions of specific fibers with long-term health benefits. © 2011 International Life Sciences Institute.
Uriniferous tubule: structural and functional organization.

PubMed

Christensen, Erik Ilsø; Wagner, Carsten A; Kaissling, Brigitte

2012-04-01

The uriniferous tubule is divided into the proximal tubule, the intermediate (thin) tubule, the distal tubule and the collecting duct. The present chapter is based on the chapters by Maunsbach and Christensen on the proximal tubule, and by Kaissling and Kriz on the distal tubule and collecting duct in the 1992 edition of the Handbook of Physiology, Renal Physiology. It describes the fine structure (light and electron microscopy) of the entire mammalian uriniferous tubule, mainly in rats, mice, and rabbits. The structural data are complemented by recent data on the location of the major transport- and transport-regulating proteins, revealed by morphological means(immunohistochemistry, immunofluorescence, and/or mRNA in situ hybridization). The structural differences along the uriniferous tubule strictly coincide with the distribution of the major luminal and basolateral transport proteins and receptors and both together provide the basis for the subdivision of the uriniferous tubule into functional subunits. Data on structural adaptation to defined functional changes in vivo and to genetical alterations of specified proteins involved in transepithelial transport importantly deepen our comprehension of the correlation of structure and function in the kidney, of the role of each segment or cell type in the overall renal function,and our understanding of renal pathophysiology. © 2012 American Physiological Society. Compr Physiol 2:933-996, 2012.
Of channels and pumps: different ways to boost the aldosterone?

PubMed

Bandulik, S

2017-07-01

The mineralocorticoid aldosterone is a major factor controlling the salt and water balance and thereby also the arterial blood pressure. Accordingly, primary aldosteronism (PA) characterized by an inappropriately high aldosterone secretion is the most common form of secondary hypertension. The physiological stimulation of aldosterone synthesis in adrenocortical glomerulosa cells by angiotensin II and an increased plasma K + concentration depends on a membrane depolarization and an increase in the cytosolic Ca 2+ activity. Recurrent gain-of-function mutations of ion channels and transporters have been identified in a majority of cases of aldosterone-producing adenomas and in familial forms of PA. In this review, the physiological role of these genes in the regulation of aldosterone synthesis and the altered function of the mutant proteins as well are described. The specific changes of the membrane potential and the cellular ion homoeostasis in adrenal cells expressing the different mutants are compared, and their impact on autonomous aldosterone production and proliferation is discussed. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.
Gastrointestinal Physiology and Function.

PubMed

Greenwood-Van Meerveld, Beverley; Johnson, Anthony C; Grundy, David

2017-01-01

The gastrointestinal (GI) system is responsible for the digestion and absorption of ingested food and liquids. Due to the complexity of the GI tract and the substantial volume of material that could be covered under the scope of GI physiology, this chapter briefly reviews the overall function of the GI tract, and discusses the major factors affecting GI physiology and function, including the intestinal microbiota, chronic stress, inflammation, and aging with a focus on the neural regulation of the GI tract and an emphasis on basic brain-gut interactions that serve to modulate the GI tract. GI diseases refer to diseases of the esophagus, stomach, small intestine, colon, and rectum. The major symptoms of common GI disorders include recurrent abdominal pain and bloating, heartburn, indigestion/dyspepsia, nausea and vomiting, diarrhea, and constipation. GI disorders rank among the most prevalent disorders, with the most common including esophageal and swallowing disorders, gastric and peptic ulcer disease, gastroparesis or delayed gastric emptying, irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD). Many GI disorders are difficult to diagnose and their symptoms are not effectively managed. Thus, basic research is required to drive the development of novel therapeutics which are urgently needed. One approach is to enhance our understanding of gut physiology and pathophysiology especially as it relates to gut-brain communications since they have clinical relevance to a number of GI complaints and represent a therapeutic target for the treatment of conditions including inflammatory diseases of the GI tract such as IBD and functional gut disorders such as IBS.
Personal reflections on a galvanizing trail.

PubMed

O'Dell, B L

1998-01-01

This article encompasses my perception of, and experience in, an exciting segment of the trace element era in nutrition research: the role of zinc in the nutrition of animals and humans. Zinc has been a major player on the stage of trace element research, and it has left a trail that galvanized the attention of many researchers, including myself. It is ubiquitous in biological systems, and it plays a multitude of physiologic and biochemical functions. A brief historical overview is followed by a discussion of the contributions the work done in my laboratory has made toward understanding the physiological and biochemical functions of zinc. The effort of 40 years has led to the belief that one of zinc's major roles, and perhaps its first limiting role, is to preserve plasma-membrane function as regards ion channels and signal transduction. Although substantial knowledge has been gained relating to the importance of zinc in nutrition, much remains to be discovered.
Transformation of a Dwarf "Arabidopsis" Mutant Illustrates Gibberellin Hormone Physiology and the Function of a Green Revolution Gene

ERIC Educational Resources Information Center

Molina, Isabel; Weber, Katrin; Alves Cursino dos Santos, Deborah Y.; Ohlrogge, John

2009-01-01

The introduction of dwarfing traits into crops was a major factor in increased grain yields during the "Green Revolution." In most cases those traits were the consequence of altered synthesis or response to the gibberellin (GA) plant hormones. Our current understanding of GA synthesis and physiology has been facilitated by the characterization of…
3Mo: A Model for Music-Based Biofeedback

PubMed Central

Maes, Pieter-Jan; Buhmann, Jeska; Leman, Marc

2016-01-01

In the domain of sports and motor rehabilitation, it is of major importance to regulate and control physiological processes and physical motion in most optimal ways. For that purpose, real-time auditory feedback of physiological and physical information based on sound signals, often termed “sonification,” has been proven particularly useful. However, the use of music in biofeedback systems has been much less explored. In the current article, we assert that the use of music, and musical principles, can have a major added value, on top of mere sound signals, to the benefit of psychological and physical optimization of sports and motor rehabilitation tasks. In this article, we present the 3Mo model to describe three main functions of music that contribute to these benefits. These functions relate the power of music to Motivate, and to Monitor and Modify physiological and physical processes. The model brings together concepts and theories related to human sensorimotor interaction with music, and specifies the underlying psychological and physiological principles. This 3Mo model is intended to provide a conceptual framework that guides future research on musical biofeedback systems in the domain of sports and motor rehabilitation. PMID:27994535
Animal Structures and Functions, Science (Experimental): 5314.13.

ERIC Educational Resources Information Center

Silver, Barbara A.

This unit of instruction was designed to introduce the student to the relationship between structure and function in the animal kingdom, with emphasis given to: (1) the evolution of physiological systems in the major animal phyla, (2) the complementarity of structure and function, and (3) the concept of homeostasis. The booklet lists the relevant…
Glutathione, Glutaredoxins, and Iron.

PubMed

Berndt, Carsten; Lillig, Christopher Horst

2017-11-20

Glutathione (GSH) is the most abundant cellular low-molecular-weight thiol in the majority of organisms in all kingdoms of life. Therefore, functions of GSH and disturbed regulation of its concentration are associated with numerous physiological and pathological situations. Recent Advances: The function of GSH as redox buffer or antioxidant is increasingly being questioned. New functions, especially functions connected to the cellular iron homeostasis, were elucidated. Via the formation of iron complexes, GSH is an important player in all aspects of iron metabolism: sensing and regulation of iron levels, iron trafficking, and biosynthesis of iron cofactors. The variety of GSH coordinated iron complexes and their functions with a special focus on FeS-glutaredoxins are summarized in this review. Interestingly, GSH analogues that function as major low-molecular-weight thiols in organisms lacking GSH resemble the functions in iron homeostasis. Since these iron-related functions are most likely also connected to thiol redox chemistry, it is difficult to distinguish between mechanisms related to either redox or iron metabolisms. The ability of GSH to coordinate iron in different complexes with or without proteins needs further investigation. The discovery of new Fe-GSH complexes and their physiological functions will significantly advance our understanding of cellular iron homeostasis. Antioxid. Redox Signal. 27, 1235-1251.
Modeling liver physiology: combining fractals, imaging and animation.

PubMed

Lin, Debbie W; Johnson, Scott; Hunt, C Anthony

2004-01-01

Physiological modeling of vascular and microvascular networks in several key human organ systems is critical for a deeper understanding of pharmacology and the effect of pharmacotherapies on disease. Like the lung and the kidney, the morphology of its vascular and microvascular system plays a major role in its functional capability. To understand liver function in absorption and metabolism of food and drugs, one must examine the morphology and physiology at both higher and lower level liver function. We have developed validated virtualized dynamic three dimensional (3D) models of liver secondary units and primary units by combining a number of different methods: three-dimensional rendering, fractals, and animation. We have simulated particle dynamics in the liver secondary unit. The resulting models are suitable for use in helping researchers easily visualize and gain intuition on results of in silico liver experiments.
Homer W. Smith's contribution to renal physiology.

PubMed

Giebisch, Gerhard

2004-01-01

Homer Smith was, for three decades, from the 1930s until his death in 1962, one of the leaders in the field of renal physiology. His contributions were many: he played a major role in introducing and popularizing renal clearance methods, introduced non-invasive methods for the measurement of glomerular filtration rate, of renal blood flow and tubular transport capacity, and provided novel insights into the mechanisms of excretion of water and electrolytes. Homer Smith's contributions went far beyond his personal investigations. He was a superb writer of several inspiring textbooks of renal physiology that exerted great and lasting influence on the development of renal physiology. Smith's intellectual insights and ability for critical analysis of data allowed him to create broad concepts that defined the functional properties of glomeruli, tubules and the renal circulation. A distinguishing feature of Homer Smith's career was his close contact and collaboration, over many years, with several clinicians of his alma mater, New York University. For initiating these pathophysiological investigations, he is justly credited to have advanced, in a major way, our understanding of altered renal function in disease. Smith's lasting scientific impact is also reflected by a whole school of investigators that trained with him and who applied his methods, analyses and concepts to the study of renal function all over the world. So great was his influence and preeminence that Robert Pitts, in his excellent tribute to Homer Smith in the Memoirs of the National Academy of Science states that his death brought an end to what might be aptly called the Smithian Era of renal physiology.
A Factor Analytic and Regression Approach to Functional Age: Potential Effects of Race.

ERIC Educational Resources Information Center

Colquitt, Alan L.; And Others

Factor analysis and multiple regression are two major approaches used to look at functional age, which takes account of the extensive variation in the rate of physiological and psychological maturation throughout life. To examine the role of racial or cultural influences on the measurement of functional age, a battery of 12 tests concentrating on…
Relationships among stressful life events and physiological markers, treatment adherence, and psychosocial functioning among youth with type 2 diabetes.

PubMed

Walders-Abramson, Natalie; Venditti, Elizabeth M; Ievers-Landis, Carolyn E; Anderson, Barbara; El Ghormli, Laure; Geffner, Mitchell; Kaplan, Joan; Koontz, Michaela B; Saletsky, Ron; Payan, Marisa; Yasuda, Patrice

2014-09-01

To examine the relationships between stressful life events and physiological measures, adherence to prescribed oral medication regimens, depressive symptoms, and impaired quality of life (QoL) in adolescents with recent-onset type 2 diabetes (T2D). Data were collected from 497 ethnically diverse participants (66% female) in the final year of the Treatment Options for Type 2 Diabetes in Adolescents and Youth multicenter clinical trial. Exposure to 32 possible events over the previous year and rating of subsequent distress were collected by self-report and summarized as a major stressors score. This score was analyzed for relationship to glycemic control (hemoglobin A1c and treatment failure), body mass index, diagnosis of hypertension or triglyceride dyslipidemia, adherence to a prescribed oral medication regimen, presence of depressive symptoms, and impaired QoL. The total number of major stressful life events in the adolescents with T2D was calculated, with 33% reporting none, 67% reporting ≥ 1, 47% reporting ≥ 2, 33% reporting ≥ 3, and 20% reporting ≥ 4. There were no associations between the major stressors score and physiological measures or diagnosis of comorbidities. The odds of medication nonadherence increased significantly from those reporting ≥ 1 major stressor (OR, 1.58; P = .0265) to those reporting ≥ 4 major stressors (OR, 2.70; P = .0009). Significant odds of elevated depressive symptoms and impaired QoL were also found with increased reporting of major stressors. Exposure to major stressful life events is associated with lower adherence to prescribed oral medication regimens and impaired psychosocial functioning in adolescents with T2D. Copyright © 2014 Elsevier Inc. All rights reserved.
Southern Ocean phytoplankton physiology in a changing climate.

PubMed

Petrou, Katherina; Kranz, Sven A; Trimborn, Scarlett; Hassler, Christel S; Ameijeiras, Sonia Blanco; Sackett, Olivia; Ralph, Peter J; Davidson, Andrew T

2016-09-20

The Southern Ocean (SO) is a major sink for anthropogenic atmospheric carbon dioxide (CO 2 ), potentially harbouring even greater potential for additional sequestration of CO 2 through enhanced phytoplankton productivity. In the SO, primary productivity is primarily driven by bottom up processes (physical and chemical conditions) which are spatially and temporally heterogeneous. Due to a paucity of trace metals (such as iron) and high variability in light, much of the SO is characterised by an ecological paradox of high macronutrient concentrations yet uncharacteristically low chlorophyll concentrations. It is expected that with increased anthropogenic CO 2 emissions and the coincident warming, the major physical and chemical process that govern the SO will alter, influencing the biological capacity and functioning of the ecosystem. This review focuses on the SO primary producers and the bottom up processes that underpin their health and productivity. It looks at the major physico-chemical drivers of change in the SO, and based on current physiological knowledge, explores how these changes will likely manifest in phytoplankton, specifically, what are the physiological changes and floristic shifts that are likely to ensue and how this may translate into changes in the carbon sink capacity, net primary productivity and functionality of the SO. Copyright © 2016 Elsevier GmbH. All rights reserved.

Physiology-driven adaptive virtual reality stimulation for prevention and treatment of stress related disorders.

PubMed

Cosić, Kresimir; Popović, Sinisa; Kukolja, Davor; Horvat, Marko; Dropuljić, Branimir

2010-02-01

The significant proportion of severe psychological problems related to intensive stress in recent large peacekeeping operations underscores the importance of effective methods for strengthening the prevention and treatment of stress-related disorders. Adaptive control of virtual reality (VR) stimulation presented in this work, based on estimation of the person's emotional state from physiological signals, may enhance existing stress inoculation training (SIT). Physiology-driven adaptive VR stimulation can tailor the progress of stressful stimuli delivery to the physiological characteristics of each individual, which is indicated for improvement in stress resistance. Following an overview of physiology-driven adaptive VR stimulation, its major functional subsystems are described in more detail. A specific algorithm of stimuli delivery applicable to SIT is outlined.
Hormonal profile impact on female sexual function in young women

NASA Astrophysics Data System (ADS)

Stoian, Dana; Craciunescu, Mihalea; Craina, Marius; Pater, Liana; Pater, Flavius

2014-12-01

Female sexual function is dependent, in physiological milieu upon hormonal impulses: estradiol, testosterone, cortisol, progesterone, prolactin and TSH. Out study tries to appreciate the impact of testosterone, estradiol and prolactin, the major hormones involved in the sexual response, on the normal sexual function. This parameter is approximated by the value of the total FSFI score, a validated international structured interview.
Orbitofrontal cortex function and structure in depression.

PubMed

Drevets, Wayne C

2007-12-01

The orbitofrontal cortex (OFC) has been implicated in the pathophysiology of major depression by evidence obtained using neuroimaging, neuropathologic, and lesion analysis techniques. The abnormalities revealed by these techniques show a regional specificity, and suggest that some OFC regions which appear cytoarchitectonically distinct also are functionally distinct with respect to mood regulation. For example, the severity of depression correlates inversely with physiological activity in parts of the posterior lateral and medial OFC, consistent with evidence that dysfunction of the OFC associated with cerebrovascular lesions increases the vulnerability for developing the major depressive syndrome. The posterior lateral and medial OFC function may also be impaired in individuals who develop primary mood disorders, as these patients show grey-matter volumetric reductions, histopathologic abnormalities, and altered hemodynamic responses to emotionally valenced stimuli, probabilistic reversal learning, and reward processing. In contrast, physiological activity in the anteromedial OFC situated in the ventromedial frontal polar cortex increases during the depressed versus the remitted phases of major depressive disorder to an extent that is positively correlated with the severity of depression. Effective antidepressant treatment is associated with a reduction in activity in this region. Taken together these data are compatible with evidence from studies in experimental animals indicating that some orbitofrontal and medial prefrontal cortex regions function to inhibit, while others function to enhance, emotional expression. Alterations in the functional balance between these regions and the circuits they form with anatomically related areas of the temporal lobe, striatum, thalamus, and brain stem thus may underlie the pathophysiology of mood disorders, such as major depression.
Regulation of the cellular and physiological effects of glutamine.

PubMed

Chwals, Walter J

2004-10-01

Glutamine is the most abundant amino acid in humans and possesses many functions in the body. It is the major transporter of amino-nitrogen between cells and an important fuel source for rapidly dividing cells such as cells of the immune and gastrointestinal systems. It is important in the synthesis of nucleic acids, glutathione, citrulline, arginine, gamma aminobutyric acid, and glucose. It is important for growth, gastrointestinal integrity, acid-base homeostasis, and optimal immune function. The regulation of glutamine levels in cells via glutaminase and glutamine synthetase is discussed. The cellular and physiologic effects of glutamine upon the central nervous system, gastrointestinal function, during metabolic support, and following tissue injury and critical illness is also discussed.
Successful Implementation of Inquiry-Based Physiology Laboratories in Undergraduate Major and Nonmajor Courses

ERIC Educational Resources Information Center

Casotti, G.; Rieser-Danner, L.; Knabb, M. T.

2008-01-01

Recent evidence has demonstrated that inquiry-based physiology laboratories improve students' critical- and analytical-thinking skills. We implemented inquiry-based learning into three physiology courses: Comparative Vertebrate Physiology (majors), Human Physiology (majors), and Human Anatomy and Physiology (nonmajors). The aims of our curricular…
Physiologic and psychobehavioral research in oncology.

PubMed

Redd, W H; Silberfarb, P M; Andersen, B L; Andrykowski, M A; Bovbjerg, D H; Burish, T G; Carpenter, P J; Cleeland, C; Dolgin, M; Levy, S M

1991-02-01

A major thrust in research in psychosocial oncology is the study of the interaction of psychologic and physiologic variables. This discussion reviews the current status and future directions of such research. Areas addressed include pain, nausea and vomiting with chemotherapy, sexuality, effects of cancer on psychologic and neuropsychologic function, impact of psychologic factors on cancer and its treatment, and psychoneuroimmunology. In addition, specific recommendations for strategies to facilitate research in these areas of psychosocial oncology are proposed.
Cone photoreceptor sensitivities and unique hue chromatic responses: correlation and causation imply the physiological basis of unique hues.

PubMed

Pridmore, Ralph W

2013-01-01

This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors) but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral) functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure) hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique) over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95-1.0) in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones.) Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision.
Cone Photoreceptor Sensitivities and Unique Hue Chromatic Responses: Correlation and Causation Imply the Physiological Basis of Unique Hues

PubMed Central

Pridmore, Ralph W.

2013-01-01

This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors) but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral) functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure) hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique) over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95–1.0) in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones.) Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision. PMID:24204755
An investigation into the relationship between age and physiological function in highly active older adults.

PubMed

Pollock, Ross D; Carter, Scott; Velloso, Cristiana P; Duggal, Niharika A; Lord, Janet M; Lazarus, Norman R; Harridge, Stephen D R

2015-02-01

The relationship between age and physiological function remains poorly defined and there are no physiological markers that can be used to reliably predict the age of an individual. This could be due to a variety of confounding genetic and lifestyle factors, and in particular to ill-defined and low levels of physical activity. This study assessed the relationship between age and a diverse range of physiological functions in a cohort of highly active older individuals (cyclists) aged 55-79 years in whom the effects of lifestyle factors would be ameliorated. Significant associations between age and function were observed for many functions. V̇O2max was most closely associated with age, but even here the variance in age for any given level was high, precluding the clear identification of the age of any individual. The data suggest that the relationship between human ageing and physiological function is highly individualistic and modified by inactivity. Despite extensive research, the relationship between age and physiological function remains poorly characterised and there are currently no reliable markers of human ageing. This is probably due to a number of confounding factors, particularly in studies of a cross-sectional nature. These include inter-subject genetic variation, as well as inter-generational differences in nutrition, healthcare and insufficient levels of physical activity as well as other environmental factors. We have studied a cohort of highly and homogeneously active older male (n = 84) and female (n = 41) cyclists aged 55-79 years who it is proposed represent a model for the study of human ageing free from the majority of confounding factors, especially inactivity. The aim of the study was to identify physiological markers of ageing by assessing the relationship between function and age across a wide range of indices. Each participant underwent a detailed physiological profiling which included measures of cardiovascular, respiratory, neuromuscular, metabolic, endocrine and cognitive functions, bone strength, and health and well-being. Significant associations between age and function were observed for many functions. The maximal rate of oxygen consumption (V̇O2max) showed the closest association with age (r = -0.443 to -0.664; P < 0.001), but even here the variance in age for any given level was high, precluding the clear identification of the age of any individual. The results of this cross-sectional study suggest that even when many confounding variables are removed the relationship between function and healthy ageing is complex and likely to be highly individualistic and that physical activity levels must be taken into account in ageing studies. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.
K+ channels of Müller glial cells in retinal disorders.

PubMed

Gao, Feng; Xu, Linjie; Zhao, Yuan; Sun, Xinghuai; Wang, Zhongfeng

2018-02-01

Müller cell is the major type glial cell in the vertebrate retina. Müller cells express various types of K+ channels, such as inwardly rectifying K+ (Kir) channels, big conductance Ca2+-activated K+ (BKCa) channels, delayed rectifier K+ channels (KDR), and transient A-type K+ channels. These K+ channels play important roles in maintaining physiological functions of Müller cells. Under some retinal pathological conditions, the changed expression and functions of K+ channels may contribute to retinal pathogenesis. In this article, we reviewed the physiological properties of K+ channels in retinal Müller cells and the functional changes of these channels in retinal disorders. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
Functional Neuroanatomy of the Noradrenergic Locus Coeruleus: Its Roles in the Regulation of Arousal and Autonomic Function Part II: Physiological and Pharmacological Manipulations and Pathological Alterations of Locus Coeruleus Activity in Humans

PubMed Central

Samuels, E. R; Szabadi, E

2008-01-01

The locus coeruleus (LC), the major noradrenergic nucleus of the brain, gives rise to fibres innervating most structures of the neuraxis. Recent advances in neuroscience have helped to unravel the neuronal circuitry controlling a number of physiological functions in which the LC plays a central role. Two such functions are the regulation of arousal and autonomic activity, which are inseparably linked largely via the involvement of the LC. Alterations in LC activity due to physiological or pharmacological manipulations or pathological processes can lead to distinct patterns of change in arousal and autonomic function. Physiological manipulations considered here include the presentation of noxious or anxiety-provoking stimuli and extremes in ambient temperature. The modification of LC-controlled functions by drug administration is discussed in detail, including drugs which directly modify the activity of LC neurones (e.g., via autoreceptors, storage, reuptake) or have an indirect effect through modulating excitatory or inhibitory inputs. The early vulnerability of the LC to the ageing process and to neurodegenerative disease (Parkinson’s and Alzheimer’s diseases) is of considerable clinical significance. In general, physiological manipulations and the administration of stimulant drugs, α2-adrenoceptor antagonists and noradrenaline uptake inhibitors increase LC activity and thus cause heightened arousal and activation of the sympathetic nervous system. In contrast, the administration of sedative drugs, including α2-adrenoceptor agonists, and pathological changes in LC function in neurodegenerative disorders and ageing reduce LC activity and result in sedation and activation of the parasympathetic nervous system. PMID:19506724
The role of lateral habenula-dorsal raphe nucleus circuits in higher brain functions and psychiatric illness.

PubMed

Zhao, Hua; Zhang, Bei-Lin; Yang, Shao-Jun; Rusak, Benjamin

2015-01-15

Serotonergic neurons in the dorsal raphe nucleus (DRN) play an important role in regulation of many physiological functions. The lateral nucleus of the habenular complex (LHb) is closely connected to the DRN both morphologically and functionally. The LHb is a key regulator of the activity of DRN serotonergic neurons, and it also receives reciprocal input from the DRN. The LHb is also a major way-station that receives limbic system input via the stria medullaris and provides output to the DRN and thereby indirectly connects a number of other brain regions to the DRN. The complex interactions of the LHb and DRN contribute to the regulation of numerous important behavioral and physiological mechanisms, including those regulating cognition, reward, pain sensitivity and patterns of sleep and waking. Disruption of these functions is characteristic of major psychiatric illnesses, so there has been a great deal of interest in how disturbed LHb-DRN interactions may contribute to the symptoms of these illnesses. This review summarizes recent research related to the roles of the LHb-DRN system in regulation of higher brain functions and the possible role of disturbed LHb-DRN function in the pathogenesis of psychiatric disorders, especially depression. Copyright © 2014 Elsevier B.V. All rights reserved.
Micronutrients for Sustainable Agriculture

USDA-ARS?s Scientific Manuscript database

The micronutrients are essential for plant growth and reproduction, however deficiencies of these elements is major cause of yield decline in many parts of the world. Micronutrients are essential for proper physiological and biological functions in plant. Climatic factors (hot humid climate), soil d...
Hericium erinaceus (Yamabushitake): a unique resource for developing functional foods and medicines.

PubMed

Wang, Mingxing; Gao, Yang; Xu, Duoduo; Konishi, Tetsuya; Gao, Qipin

2014-12-01

Hericium erinaceus (HE) is a fungus inhabiting the mountainous areas of the northeast territories in Asia. HE has been used in traditional folk medicine and medicinal cuisine in China, Korea and Japan. Evidence has been adduced for a variety of physiological effects, including anti-aging, anti-cancer, anti-gastritis, and anti-metabolic disease properties. Hence, HE is an attractive target resource for developing not only medicines, but also functional foods. Basic studies on the physiological functions of HE and on the chemical identification of its active ingredients have progressed in recent decades. In this article, we provide an overview of the biochemical and pharmacological studies on HE, especially of its antitumor and neuroprotective functions, together with a survey of recent developments in the chemical analysis of its polysaccharides, which comprise its major active components.
Alternative electron flows (water-water cycle and cyclic electron flow around PSI) in photosynthesis: molecular mechanisms and physiological functions.

PubMed

Miyake, Chikahiro

2010-12-01

An electron flow in addition to the major electron sinks in C(3) plants [both photosynthetic carbon reduction (PCR) and photorespiratory carbon oxidation (PCO) cycles] is termed an alternative electron flow (AEF) and functions in the chloroplasts of leaves. The water-water cycle (WWC; Mehler-ascorbate peroxidase pathway) and cyclic electron flow around PSI (CEF-PSI) have been studied as the main AEFs in chloroplasts and are proposed to play a physiologically important role in both the regulation of photosynthesis and the alleviation of photoinhibition. In the present review, I discuss the molecular mechanisms of both AEFs and their functions in vivo. To determine their physiological function, accurate measurement of the electron flux of AEFs in vivo are required. Methods to assay electron flux in CEF-PSI have been developed recently and their problematic points are discussed. The common physiological function of both the WWC and CEF-PSI is the supply of ATP to drive net CO(2) assimilation. The requirement for ATP depends on the activities of both PCR and PCO cycles, and changes in both WWC and CEF-PSI were compared with the data obtained in intact leaves. Furthermore, the fact that CEF-PSI cannot function independently has been demonstrated. I propose a model for the regulation of CEF-PSI by WWC, in which WWC is indispensable as an electron sink for the expression of CEF-PSI activity.
What Has Natural Variation Taught Us about Plant Development, Physiology, and Adaptation?

PubMed Central

Alonso-Blanco, Carlos; Aarts, Mark G.M.; Bentsink, Leonie; Keurentjes, Joost J.B.; Reymond, Matthieu; Vreugdenhil, Dick; Koornneef, Maarten

2009-01-01

Nearly 100 genes and functional polymorphisms underlying natural variation in plant development and physiology have been identified. In crop plants, these include genes involved in domestication traits, such as those related to plant architecture, fruit and seed structure and morphology, as well as yield and quality traits improved by subsequent crop breeding. In wild plants, comparable traits have been dissected mainly in Arabidopsis thaliana. In this review, we discuss the major contributions of the analysis of natural variation to our understanding of plant development and physiology, focusing in particular on the timing of germination and flowering, plant growth and morphology, primary metabolism, and mineral accumulation. Overall, functional polymorphisms appear in all types of genes and gene regions, and they may have multiple mutational causes. However, understanding this diversity in relation to adaptation and environmental variation is a challenge for which tools are now available. PMID:19574434
Motion compensation for in vivo subcellular optical microscopy.

PubMed

Lucotte, B; Balaban, R S

2014-04-01

In this review, we focus on the impact of tissue motion on attempting to conduct subcellular resolution optical microscopy, in vivo. Our position is that tissue motion is one of the major barriers in conducting these studies along with light induced damage, optical probe loading as well as absorbing and scattering effects on the excitation point spread function and collection of emitted light. Recent developments in the speed of image acquisition have reached the limit, in most cases, where the signal from a subcellular voxel limits the speed and not the scanning rate of the microscope. Different schemes for compensating for tissue displacements due to rigid body and deformation are presented from tissue restriction, gating, adaptive gating and active tissue tracking. We argue that methods that minimally impact the natural physiological motion of the tissue are desirable because the major reason to perform in vivo studies is to evaluate normal physiological functions. Towards this goal, active tracking using the optical imaging data itself to monitor tissue displacement and either prospectively or retrospectively correct for the motion without affecting physiological processes is desirable. Critical for this development was the implementation of near real time image processing in conjunction with the control of the microscope imaging parameters. Clearly, the continuing development of methods of motion compensation as well as significant technological solutions to the other barriers to tissue subcellular optical imaging in vivo, including optical aberrations and overall signal-to-noise ratio, will make major contributions to the understanding of cell biology within the body.
Nematode sperm maturation triggered by protease involves sperm-secreted serine protease inhibitor (Serpin)

PubMed Central

Zhao, Yanmei; Sun, Wei; Zhang, Pan; Chi, Hao; Zhang, Mei-Jun; Song, Chun-Qing; Ma, Xuan; Shang, Yunlong; Wang, Bin; Hu, Youqiao; Hao, Zhiqi; Hühmer, Andreas F.; Meng, Fanxia; L'Hernault, Steven W.; He, Si-Min; Dong, Meng-Qiu; Miao, Long

2012-01-01

Spermiogenesis is a series of poorly understood morphological, physiological and biochemical processes that occur during the transition of immotile spermatids into motile, fertilization-competent spermatozoa. Here, we identified a Serpin (serine protease inhibitor) family protein (As_SRP-1) that is secreted from spermatids during nematode Ascaris suum spermiogenesis (also called sperm activation) and we showed that As_SRP-1 has two major functions. First, As_SRP-1 functions in cis to support major sperm protein (MSP)-based cytoskeletal assembly in the spermatid that releases it, thereby facilitating sperm motility acquisition. Second, As_SRP-1 released from an activated sperm inhibits, in trans, the activation of surrounding spermatids by inhibiting vas deferens-derived As_TRY-5, a trypsin-like serine protease necessary for sperm activation. Because vesicular exocytosis is necessary to create fertilization-competent sperm in many animal species, components released during this process might be more important modulators of the physiology and behavior of surrounding sperm than was previously appreciated. PMID:22307610
The endothelial glycocalyx

PubMed Central

Yang, Yimu; Schmidt, Eric P.

2013-01-01

Once thought to be a structure of small size and uncertain significance, the endothelial glycocalyx is now known to be an important regulator of endothelial function. Studies of the systemic vasculature have demonstrated that the glycocalyx forms a substantial in vivo endothelial surface layer (ESL) critical to inflammation, barrier function and mechanotransduction. The pulmonary ESL is significantly thicker than the systemic ESL, suggesting unique physiologic function. We have recently demonstrated that the pulmonary ESL regulates exposure of endothelial surface adhesion molecules, thereby serving as a barrier to neutrophil adhesion and extravasation. While the pulmonary ESL is not a critical structural component of the endothelial barrier to fluid and protein, it serves a major role in the mechanotransduction of vascular pressure, with impact on the active regulation of endothelial permeability. It is likely that the ESL serves numerous additional functions in vascular physiology, representing a fertile area for future investigation. PMID:24073386
Analysis of undergraduate students' conceptual models of a complex biological system across a diverse body of learners

NASA Astrophysics Data System (ADS)

Dirnbeck, Matthew R.

Biological systems pose a challenge both for learners and teachers because they are complex systems mediated by feedback loops; networks of cause-effect relationships; and non-linear, hierarchical, and emergent properties. Teachers and scientists routinely use models to communicate ideas about complex systems. Model-based pedagogies engage students in model construction as a means of practicing higher-order reasoning skills. One such modeling paradigm describes systems in terms of their structures, behaviors, and functions (SBF). The SBF framework is a simple modeling language that has been used to teach about complex biological systems. Here, we used student-generated SBF models to assess students' causal reasoning in the context of a novel biological problem on an exam. We compared students' performance on the modeling problem, their performance on a set of knowledge/comprehension questions, and their performance on a set of scientific reasoning questions. We found that students who performed well on knowledge and understanding questions also constructed more networked, higher quality models. Previous studies have shown that learners' mental maps increase in complexity with increased expertise. We wanted to investigate if biology students with varying levels of training in biology showed a similar pattern when constructing system models. In a pilot study, we administered the same modeling problem to two additional groups of students: 1) an animal physiology course for students pursuing a major in biology (n=37) and 2) an exercise physiology course for non-majors (n=27). We found that there was no significant difference in model organization across the three student populations, but there was a significant difference in the ability to represent function between the three populations. Between the three groups the non-majors had the lowest function scores, the introductory majors had the middle function scores, and the upper division majors had the highest function scores.

Safety Needs Mediate Stressful Events Induced Mental Disorders.

PubMed

Zheng, Zheng; Gu, Simeng; Lei, Yu; Lu, Shanshan; Wang, Wei; Li, Yang; Wang, Fushun

2016-01-01

"Safety first," we say these words almost every day, but we all take this for granted for what Maslow proposed in his famous theory of Hierarchy of Needs : safety needs come second to physiological needs. Here we propose that safety needs come before physiological needs. Safety needs are personal security, financial security, and health and well-being, which are more fundamental than physiological needs. Safety worrying is the major reason for mental disorders, such as anxiety, phobia, depression, and PTSD. The neural basis for safety is amygdala, LC/NE system, and corticotrophin-releasing hormone system, which can be regarded as a "safety circuitry," whose major behavior function is "fight or flight" and "fear and anger" emotions. This is similar to the Appraisal theory for emotions: fear is due to the primary appraisal, which is related to safety of individual, while anger is due to secondary appraisal, which is related to coping with the unsafe situations. If coping is good, the individual will be happy; if coping failed, the individual will be sad or depressed.
An investigation into the relationship between age and physiological function in highly active older adults

PubMed Central

Pollock, Ross D; Carter, Scott; Velloso, Cristiana P; Duggal, Niharika A; Lord, Janet M; Lazarus, Norman R; Harridge, Stephen D R

2015-01-01

Despite extensive research, the relationship between age and physiological function remains poorly characterised and there are currently no reliable markers of human ageing. This is probably due to a number of confounding factors, particularly in studies of a cross-sectional nature. These include inter-subject genetic variation, as well as inter-generational differences in nutrition, healthcare and insufficient levels of physical activity as well as other environmental factors. We have studied a cohort of highly and homogeneously active older male (n = 84) and female (n = 41) cyclists aged 55–79 years who it is proposed represent a model for the study of human ageing free from the majority of confounding factors, especially inactivity. The aim of the study was to identify physiological markers of ageing by assessing the relationship between function and age across a wide range of indices. Each participant underwent a detailed physiological profiling which included measures of cardiovascular, respiratory, neuromuscular, metabolic, endocrine and cognitive functions, bone strength, and health and well-being. Significant associations between age and function were observed for many functions. The maximal rate of oxygen consumption ( showed the closest association with age (r = −0.443 to −0.664; P < 0.001), but even here the variance in age for any given level was high, precluding the clear identification of the age of any individual. The results of this cross-sectional study suggest that even when many confounding variables are removed the relationship between function and healthy ageing is complex and likely to be highly individualistic and that physical activity levels must be taken into account in ageing studies. Key Points The relationship between age and physiological function remains poorly defined and there are no physiological markers that can be used to reliably predict the age of an individual. This could be due to a variety of confounding genetic and lifestyle factors, and in particular to ill-defined and low levels of physical activity. This study assessed the relationship between age and a diverse range of physiological functions in a cohort of highly active older individuals (cyclists) aged 55–79 years in whom the effects of lifestyle factors would be ameliorated. Significant associations between age and function were observed for many functions. was most closely associated with age, but even here the variance in age for any given level was high, precluding the clear identification of the age of any individual. The data suggest that the relationship between human ageing and physiological function is highly individualistic and modified by inactivity. PMID:25565071
A novel TaqI polymorphism in the coding region of the ovine TNXB gene in the MHC class III region: morphostructural and physiological influences.

PubMed

Ajayi, Oyeyemi O; Adefenwa, Mufliat A; Agaviezor, Brilliant O; Ikeobi, Christian O N; Wheto, Matthew; Okpeku, Moses; Amusan, Samuel A; Yakubu, Abdulmojeed; De Donato, Marcos; Peters, Sunday O; Imumorin, Ikhide G

2014-02-01

The tenascin-XB (TNXB) gene has antiadhesive effects, functions in matrix maturation in connective tissues, and localizes to the major histocompatibility complex class III region. We hypothesized that it may influence adaptive physiological response through an effect on blood vessel function. We identified a novel g.1324 A→G polymorphism at a TaqI recognition site in a 454 bp fragment of ovine TNXB and genotyped it in 150 Nigerian sheep using PCR-RFLP. The missense mutation changes glutamic acid (GAA) to glycine (GGA). Among SNP genotypes, significant differences (P < 0.05) were observed in body weight and fore cannon bone length. Interaction effects of breed, SNP genotype, and geographic location had a significant effect (P < 0.05) on chest girth. The SNP genotype was significantly (P < 0.05) associated with physiological traits of pulse rate and skin temperature. The observed effect of this novel polymorphism may be mediated through its role in connective tissue biology, requiring further association and functional studies.
Misalignment with the external light environment drives metabolic and cardiac dysfunction.

PubMed

West, Alexander C; Smith, Laura; Ray, David W; Loudon, Andrew S I; Brown, Timothy M; Bechtold, David A

2017-09-12

Most organisms use internal biological clocks to match behavioural and physiological processes to specific phases of the day-night cycle. Central to this is the synchronisation of internal processes across multiple organ systems. Environmental desynchrony (e.g. shift work) profoundly impacts human health, increasing cardiovascular disease and diabetes risk, yet the underlying mechanisms remain unclear. Here, we characterise the impact of desynchrony between the internal clock and the external light-dark (LD) cycle on mammalian physiology. We reveal that even under stable LD environments, phase misalignment has a profound effect, with decreased metabolic efficiency and disrupted cardiac function including prolonged QT interval duration. Importantly, physiological dysfunction is not driven by disrupted core clock function, nor by an internal desynchrony between organs, but rather the altered phase relationship between the internal clockwork and the external environment. We suggest phase misalignment as a major driver of pathologies associated with shift work, chronotype and social jetlag.The misalignment between internal circadian rhythm and the day-night cycle can be caused by genetic, behavioural and environmental factors, and may have a profound impact on human physiology. Here West et al. show that desynchrony between the internal clock and the external environment alter metabolic parameters and cardiac function in mice.
Nuclear cardiac

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slutsky, R.; Ashburn, W.L.

1982-01-01

The relationship between nuclear medicine and cardiology has continued to produce a surfeit of interesting, illuminating, and important reports involving the analysis of cardiac function, perfusion, and metabolism. To simplify the presentation, this review is broken down into three major subheadings: analysis of myocardial perfusion; imaging of the recent myocardial infarction; and the evaluation of myocardial function. There appears to be an increasingly important relationship between cardiology, particularly cardiac physiology, and nuclear imaging techniques. (KRM)
Physiological and pharmacological characterization of the larval Anopheles albimanus rectum supports a change in protein distribution and/or function in varying salinities

PubMed Central

Smith, Kristin E.; Raymond, Steven L.; Valenti, Micheala L.; Smith, Peter J.S.; Linser, Paul J.

2010-01-01

Ion regulation is a biological process crucial to the survival of mosquito larvae and a major organ responsible for this regulation is the rectum. The recta of anopheline larvae are distinct from other subfamilies of mosquitoes in several ways, yet have not yet been characterized extensively. Here we characterize the two major cell types of the anopheline rectum, DAR and non-DAR cells, using histological, physiological, and pharmacological analyses. Proton flux was measured at the basal membrane of 2%- and 50%-artificial sea water-reared An. albimanus larvae using self-referencing ion-selective microelectrodes, and the two cell types were found to differ in basal membrane proton flux. Additionally, differences in the response of that flux to pharmacological inhibitors in larvae reared in 2% versus 50% ASW indicate changes in protein function between the two rearing conditions. Finally, histological analyses suggest that the non-DAR cells are structurally suited for mediating ion transport. These data support a model of rectal ion regulation in which the non-DAR cells have a resorptive function in freshwater-reared larvae and a secretive function in saline water-reared larvae. In this way, anopheline larvae may adapt to varying salinities. PMID:20460167
Therapeutic potential of metabotropic glutamate receptor modulators.

PubMed

Hovelsø, N; Sotty, F; Montezinho, L P; Pinheiro, P S; Herrik, K F; Mørk, A

2012-03-01

Glutamate is the main excitatory neurotransmitter in the central nervous system (CNS) and is a major player in complex brain functions. Glutamatergic transmission is primarily mediated by ionotropic glutamate receptors, which include NMDA, AMPA and kainate receptors. However, glutamate exerts modulatory actions through a family of metabotropic G-protein-coupled glutamate receptors (mGluRs). Dysfunctions of glutamatergic neurotransmission have been implicated in the etiology of several diseases. Therefore, pharmacological modulation of ionotropic glutamate receptors has been widely investigated as a potential therapeutic strategy for the treatment of several disorders associated with glutamatergic dysfunction. However, blockade of ionotropic glutamate receptors might be accompanied by severe side effects due to their vital role in many important physiological functions. A different strategy aimed at pharmacologically interfering with mGluR function has recently gained interest. Many subtype selective agonists and antagonists have been identified and widely used in preclinical studies as an attempt to elucidate the role of specific mGluRs subtypes in glutamatergic transmission. These studies have allowed linkage between specific subtypes and various physiological functions and more importantly to pathological states. This article reviews the currently available knowledge regarding the therapeutic potential of targeting mGluRs in the treatment of several CNS disorders, including schizophrenia, addiction, major depressive disorder and anxiety, Fragile X Syndrome, Parkinson's disease, Alzheimer's disease and pain.
Reproduction Alters Hydration State but Does Not Impact the Positive Effects of Dehydration on Innate Immune Function in Children's Pythons (Antaresia childreni).

PubMed

Brusch, George A; Billy, Gopal; Blattman, Joseph N; DeNardo, Dale F

Resource availability can impact immune function, with the majority of studies of such influences focusing on the allocation of energy investment into immune versus other physiological functions. When energy is a limited resource, performance trade-offs can result, compromising immunity. Dehydration is also considered a physiological challenge resulting from the limitation of a vital resource, yet previous research has found a positive relationship between dehydration and innate immune performance. However, these studies did not examine the effects of dehydration on immunity when there was another concurrent, substantial physiological challenge. Thus, we examined the impact of reproduction and water deprivation, individually and in combination, on immune performance in Children's pythons (Antaresia childreni). We collected blood samples from free-ranging A. childreni to evaluate osmolality and innate immune function (lysis, agglutination, bacterial growth inhibition) during the austral dry season, when water availability is limited and this species is typically reproducing. To examine how reproduction and water imbalance, both separately and combined, impact immune function, we used a laboratory-based 2 × 2 experiment. Our results demonstrate that A. childreni experience significant dehydration during the dry season and that, overall, osmolality, regardless of the underlying cause (seasonal rainfall, water deprivation, or reproduction), is positively correlated with increased innate immune performance.
Revised Guidelines for Comprehensive Health Education, Grades 10-12.

ERIC Educational Resources Information Center

Nebraska State Dept. of Education, Lincoln. Div. of Instructional Services.

These health curriculum guidelines were designed for teachers of secondary students. Four major topic areas are covered: 1) anatomy, physiology, tissues, systems, heredity, physical activity, and nutriition; 2) family structures, functions, and responsibilities; 3) values, stress, and drug abuse; and 4) the environment, disease control, cancer,…
Physiological geroscience: targeting function to increase healthspan and achieve optimal longevity.

PubMed

Seals, Douglas R; Justice, Jamie N; LaRocca, Thomas J

2016-04-15

Most nations of the world are undergoing rapid and dramatic population ageing, which presents great socio-economic challenges, as well as opportunities, for individuals, families, governments and societies. The prevailing biomedical strategy for reducing the healthcare impact of population ageing has been 'compression of morbidity' and, more recently, to increase healthspan, both of which seek to extend the healthy period of life and delay the development of chronic diseases and disability until a brief period at the end of life. Indeed, a recently established field within biological ageing research, 'geroscience', is focused on healthspan extension. Superimposed on this background are new attitudes and demand for 'optimal longevity' - living long, but with good health and quality of life. A key obstacle to achieving optimal longevity is the progressive decline in physiological function that occurs with ageing, which causes functional limitations (e.g. reduced mobility) and increases the risk of chronic diseases, disability and mortality. Current efforts to increase healthspan centre on slowing the fundamental biological processes of ageing such as inflammation/oxidative stress, increased senescence, mitochondrial dysfunction, impaired proteostasis and reduced stress resistance. We propose that optimization of physiological function throughout the lifespan should be a major emphasis of any contemporary biomedical policy addressing global ageing. Effective strategies should delay, reduce in magnitude or abolish reductions in function with ageing (primary prevention) and/or improve function or slow further declines in older adults with already impaired function (secondary prevention). Healthy lifestyle practices featuring regular physical activity and ideal energy intake/diet composition represent first-line function-preserving strategies, with pharmacological agents, including existing and new pharmaceuticals and novel 'nutraceutical' compounds, serving as potential complementary approaches. Future research efforts should focus on defining the temporal patterns of functional declines with ageing, identifying the underlying mechanisms and modulatory factors involved, and establishing the most effective lifestyle practices and pharmacological options for maintaining function. Continuing development of effective behavioural approaches for enhancing adherence to healthy ageing practices in diverse populations, and ongoing analysis of the socio-economic costs and benefits of healthspan extension will be important supporting goals. To meet the demands created by rapid population ageing, a new emphasis in physiological geroscience is needed, which will require the collaborative, interdisciplinary efforts of investigators working throughout the translational research continuum from basic science to public health. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.
Conservation physiology of marine fishes: state of the art and prospects for policy.

PubMed

McKenzie, David J; Axelsson, Michael; Chabot, Denis; Claireaux, Guy; Cooke, Steven J; Corner, Richard A; De Boeck, Gudrun; Domenici, Paolo; Guerreiro, Pedro M; Hamer, Bojan; Jørgensen, Christian; Killen, Shaun S; Lefevre, Sjannie; Marras, Stefano; Michaelidis, Basile; Nilsson, Göran E; Peck, Myron A; Perez-Ruzafa, Angel; Rijnsdorp, Adriaan D; Shiels, Holly A; Steffensen, John F; Svendsen, Jon C; Svendsen, Morten B S; Teal, Lorna R; van der Meer, Jaap; Wang, Tobias; Wilson, Jonathan M; Wilson, Rod W; Metcalfe, Julian D

2016-01-01

The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiological knowledge for conservation of marine fishes is the limited knowledge base; international collaboration is needed to study the environmental physiology of a wider range of species. Multifactorial field and laboratory studies on biomarkers hold promise to relate ecophysiology directly to habitat quality and population status. The 'Fry paradigm' could have broad applications for conservation physiology research if it provides a universal mechanism to link physiological function with ecological performance and population dynamics of fishes, through effects of abiotic conditions on aerobic metabolic scope. The available data indicate, however, that the paradigm is not universal, so further research is required on a wide diversity of species. Fish physiologists should interact closely with researchers developing ecological models, in order to investigate how integrating physiological information improves confidence in projecting effects of global change; for example, with mechanistic models that define habitat suitability based upon potential for aerobic scope or outputs of a dynamic energy budget. One major challenge to upscaling from physiology of individuals to the level of species and communities is incorporating intraspecific variation, which could be a crucial component of species' resilience to global change. Understanding what fishes do in the wild is also a challenge, but techniques of biotelemetry and biologging are providing novel information towards effective conservation. Overall, fish physiologists must strive to render research outputs more applicable to management and decision-making. There are various potential avenues for information flow, in the shorter term directly through biomarker studies and in the longer term by collaborating with modellers and fishery biologists.
Dissipative structures and biological rhythms

NASA Astrophysics Data System (ADS)

Goldbeter, Albert

2017-10-01

Sustained oscillations abound in biological systems. They occur at all levels of biological organization over a wide range of periods, from a fraction of a second to years, and with a variety of underlying mechanisms. They control major physiological functions, and their dysfunction is associated with a variety of physiological disorders. The goal of this review is (i) to give an overview of the main rhythms observed at the cellular and supracellular levels, (ii) to briefly describe how the study of biological rhythms unfolded in the course of time, in parallel with studies on chemical oscillations, (iii) to present the major roles of biological rhythms in the control of physiological functions, and (iv) the pathologies associated with the alteration, disappearance, or spurious occurrence of biological rhythms. Two tables present the main examples of cellular and supracellular rhythms ordered according to their period, and their role in physiology and pathophysiology. Among the rhythms discussed are neural and cardiac rhythms, metabolic oscillations such as those occurring in glycolysis in yeast, intracellular Ca++ oscillations, cyclic AMP oscillations in Dictyostelium amoebae, the segmentation clock that controls somitogenesis, pulsatile hormone secretion, circadian rhythms which occur in all eukaryotes and some bacteria with a period close to 24 h, the oscillatory dynamics of the enzymatic network driving the cell cycle, and oscillations in transcription factors such as NF-ΚB and tumor suppressors such as p53. Ilya Prigogine's concept of dissipative structures applies to temporal oscillations and allows us to unify within a common framework the various rhythms observed at different levels of biological organization, regardless of their period and underlying mechanism.
Albumin modification and fragmentation in renal disease.

PubMed

Donadio, Carlo; Tognotti, Danika; Donadio, Elena

2012-02-18

Albumin is the most important antioxidant substance in plasma and performs many physiological functions. Furthermore, albumin is the major carrier of endogenous molecules and exogenous ligands. This paper reviews the importance of post-translational modifications of albumin and fragments thereof in patients with renal disease. First, current views and controversies on renal handling of proteins, mainly albumin, will be discussed. Post-translational modifications, namely the fragmentation of albumin found with proteomic techniques in nephrotic patients, diabetics, and ESRD patients will be presented and discussed. It is reasonable to hypothesize that proteolytic fragmentation of serum albumin is due to a higher susceptibility to proteases, induced by oxidative stress. The clinical relevance of the fragmentation of albumin has not yet been established. These modifications could affect some physiological functions of albumin and have a patho-physiological role in uremic syndrome. Proteomic analysis of serum allows the identification of over-expressed proteins and can detect post-translational modifications of serum proteins, hitherto hidden, using standard laboratory techniques. Copyright © 2011 Elsevier B.V. All rights reserved.
Hybrid Enhanced Epidermal SpaceSuit Design Approaches

NASA Astrophysics Data System (ADS)

Jessup, Joseph M.

A Space suit that does not rely on gas pressurization is a multi-faceted problem that requires major stability controls to be incorporated during design and construction. The concept of Hybrid Epidermal Enhancement space suit integrates evolved human anthropomorphic and physiological adaptations into its functionality, using commercially available bio-medical technologies to address shortcomings of conventional gas pressure suits, and the impracticalities of MCP suits. The prototype HEE Space Suit explored integumentary homeostasis, thermal control and mobility using advanced bio-medical materials technology and construction concepts. The goal was a space suit that functions as an enhanced, multi-functional bio-mimic of the human epidermal layer that works in attunement with the wearer rather than as a separate system. In addressing human physiological requirements for design and construction of the HEE suit, testing regimes were devised and integrated into the prototype which was then subject to a series of detailed tests using both anatomical reproduction methods and human subject.
Circadian physiology of metabolism.

PubMed

Panda, Satchidananda

2016-11-25

A majority of mammalian genes exhibit daily fluctuations in expression levels, making circadian expression rhythms the largest known regulatory network in normal physiology. Cell-autonomous circadian clocks interact with daily light-dark and feeding-fasting cycles to generate approximately 24-hour oscillations in the function of thousands of genes. Circadian expression of secreted molecules and signaling components transmits timing information between cells and tissues. Such intra- and intercellular daily rhythms optimize physiology both by managing energy use and by temporally segregating incompatible processes. Experimental animal models and epidemiological data indicate that chronic circadian rhythm disruption increases the risk of metabolic diseases. Conversely, time-restricted feeding, which imposes daily cycles of feeding and fasting without caloric reduction, sustains robust diurnal rhythms and can alleviate metabolic diseases. These findings highlight an integrative role of circadian rhythms in physiology and offer a new perspective for treating chronic diseases in which metabolic disruption is a hallmark. Copyright © 2016, American Association for the Advancement of Science.
Childhood adversity predicts reduced physiological flexibility during the processing of negative affect among adolescents with major depression histories.

PubMed

Daches, Shimrit; Kovacs, Maria; George, Charles J; Yaroslavsky, Ilya; Kiss, Eniko; Vetró, Ágnes; Dochnal, Roberta; Benák, István; Baji, Ildikó; Halas, Kitti; Makai, Attila; Kapornai, Krisztina; Rottenberg, Jonathan

2017-11-01

Adversity during early development has been shown to have enduring negative physiological consequences. In turn, atypical physiological functioning has been associated with maladaptive processing of negative affect, including its regulation. The present study therefore explored whether exposure to adverse life events in childhood predicted maladaptive (less flexible) parasympathetic nervous system functioning during the processing of negative affect among adolescents with depression histories. An initially clinic-referred, pediatric sample (N=189) was assessed at two time points. At Time 1, when subjects were 10.17years old (SD=1.42), on average, and were depressed, parents reported on adverse life events the offspring experienced up to that point. At Time 2, when subjects were 17.18years old (SD=1.28), and were remitted from depression, parents again reported on adverse life events in their offspring's lives for the interim period. At time 2, subjects' parasympathetic nervous system functioning (quantified as respiratory sinus arrhythmia) also was assessed at rest, during sad mood induction, and during instructed mood repair. Extent of adverse life events experienced by T1 (but not events occurring between T1 and T2) predicted less flexible RSA functioning 7years later during the processing of negative affect. Adolescents with more extensive early life adversities exhibited less vagal withdrawal following negative mood induction and tended to show less physiological recovery following mood repair. Early adversities appear to be associated with less flexible physiological regulatory control during negative affect experience, when measured later in development. Stress-related autonomic dysfunction in vulnerable youths may contribute to the unfavorable clinical prognosis associated with juvenile-onset depression. Copyright © 2017 Elsevier B.V. All rights reserved.
SEASONAL HEPATIC CYTOCHROME P-450 INDUCTION IN COTTON RATS (SIGMODON HISPIDUS) INHABITING PETROCHEMICAL WASTE SITES. (R826242)

EPA Science Inventory

Abstract
Wildlife species inhabiting contaminated sites are often exposed to complex mixtures of chemicals that have known effects on physiological and biochemical function. We evaluated the induction of major hepatic cytochrome P-450 isoenzymes through O-dealky...
Alpha-Tocopherol modulates transcriptional activities that affect essential biological processes in Bovine Cells

USDA-ARS?s Scientific Manuscript database

Alpha-tocopherol is the major isoform of vitamin E. after nearly 100 years of research and countless publications, the physiological functions of vitamin E remain mysterious to a certain degree. Nevertheless, vitamin E is one of the most commonly used single nutrient supplements. Recent data has su...
Sterol Metabolism Disorders and Neurodevelopment--An Update

ERIC Educational Resources Information Center

Kanungo, Shibani; Soares, Neelkamal; He, Miao; Steiner, Robert D.

2013-01-01

Cholesterol has numerous quintessential functions in normal cell physiology, as well as in embryonic and postnatal development. It is a major component of cell membranes and myelin, and is a precursor of steroid hormones and bile acids. The development of the blood brain barrier likely around 12-18 weeks of human gestation makes the developing…
Expression of regulatory proteins in choroid plexus changes in early stages of Alzheimer disease.

PubMed

Krzyzanowska, Agnieszka; García-Consuegra, Inés; Pascual, Consuelo; Antequera, Desiree; Ferrer, Isidro; Carro, Eva

2015-04-01

Recent studies indicate that the choroid plexus has important physiologic and pathologic roles in Alzheimer disease (AD). To obtain additional insight on choroid plexus function, we performed a proteomic analysis of choroid plexus samples from patients with AD stages I to II (n = 16), III to IV (n = 16), and V to VI (n = 11) and 7 age-matched control subjects. We used 2-dimensional differential gel electrophoresis coupled with mass spectrometry to generate a complete picture of changes in choroid plexus protein expression occurring in AD patients. We identified 6 proteins: 14-3-3 β/α, 14-3-3 ε, moesin, proteasome activator complex subunit 1, annexin V, and aldehyde dehydrogenase, which were significantly regulated in AD patient samples (p < 0.05, >1.5-fold variation in expression vs control samples). These proteins are implicated in major physiologic functions including mitochondrial dysfunction and apoptosis regulation. These findings contribute additional significance to the emerging importance of molecular and functional changes of choroid plexus function in the pathophysiology of AD.

Plant Ion Channels: Gene Families, Physiology, and Functional Genomics Analyses

PubMed Central

Ward, John M.; Mäser, Pascal; Schroeder, Julian I.

2016-01-01

Distinct potassium, anion, and calcium channels in the plasma membrane and vacuolar membrane of plant cells have been identified and characterized by patch clamping. Primarily owing to advances in Arabidopsis genetics and genomics, and yeast functional complementation, many of the corresponding genes have been identified. Recent advances in our understanding of ion channel genes that mediate signal transduction and ion transport are discussed here. Some plant ion channels, for example, ALMT and SLAC anion channel subunits, are unique. The majority of plant ion channel families exhibit homology to animal genes; such families include both hyperpolarization-and depolarization-activated Shaker-type potassium channels, CLC chloride transporters/channels, cyclic nucleotide–gated channels, and ionotropic glutamate receptor homologs. These plant ion channels offer unique opportunities to analyze the structural mechanisms and functions of ion channels. Here we review gene families of selected plant ion channel classes and discuss unique structure-function aspects and their physiological roles in plant cell signaling and transport. PMID:18842100
Plant ion channels: gene families, physiology, and functional genomics analyses.

PubMed

Ward, John M; Mäser, Pascal; Schroeder, Julian I

2009-01-01

Distinct potassium, anion, and calcium channels in the plasma membrane and vacuolar membrane of plant cells have been identified and characterized by patch clamping. Primarily owing to advances in Arabidopsis genetics and genomics, and yeast functional complementation, many of the corresponding genes have been identified. Recent advances in our understanding of ion channel genes that mediate signal transduction and ion transport are discussed here. Some plant ion channels, for example, ALMT and SLAC anion channel subunits, are unique. The majority of plant ion channel families exhibit homology to animal genes; such families include both hyperpolarization- and depolarization-activated Shaker-type potassium channels, CLC chloride transporters/channels, cyclic nucleotide-gated channels, and ionotropic glutamate receptor homologs. These plant ion channels offer unique opportunities to analyze the structural mechanisms and functions of ion channels. Here we review gene families of selected plant ion channel classes and discuss unique structure-function aspects and their physiological roles in plant cell signaling and transport.
[Physical rehabilitation in multiple sclerosis: general principles and high-tech approaches].

PubMed

Peresedova, A V; Chernikova, L A; Zavalishin, I A

2013-01-01

In a chronic and disabling disease like multiple sclerosis, rehabilitation programs are of major importance for the preservation of physical, physiological, social and professional functioning and improvement of quality of life. Currently, it is generally assumed that physical activity is an important component of non-pharmacological rehabilitation in multiple sclerosis. Properly organized exercise is a safe and efficient way to induce improvements in a number of physiological functions. A multidisciplinary rehabilitative approach should be recommended. The main recommendations for the use of exercise for patients with multiple sclerosis have been listed. An important aspect of the modern physical rehabilitation in multiple sclerosis is the usage of high-tech methods. The published results of robot-assisted training to improve the hand function and walking impairment have been represented. An important trend in the rehabilitation of patients with multiple sclerosis is the reduction of postural disorders through training balance coordination. The role of transcranial magnetic stimulation in spasticity reducing is being investigated. The use of telemedicine capabilities is quite promising. Due to the fact that the decline in physical activity can lead to the deterioration of many aspects of physiological functions and, ultimately, to mobility decrease, further research of the role of physical rehabilitation as an important therapeutic approach in preventing the progression of disability in multiple sclerosis is required.
Hop (Humulus lupulus L.) response mechanisms in drought stress: Proteomic analysis with physiology.

PubMed

Kolenc, Zala; Vodnik, Dominik; Mandelc, Stanislav; Javornik, Branka; Kastelec, Damijana; Čerenak, Andreja

2016-08-01

Drought is one of the major environmental devastating stressors that impair the growth and productivity of crop plants. Despite the relevance of drought stress, changes in physiology and resistance mechanisms are not completely understood for certain crops, including hop (Humulus lupulus L.). In this research the drought response of hop was studied using a conventional physiological approach (gas exchange techniques, fluorescence, relative water content measurements) and proteomic analysis (2D-DIGE). Plants of two cultivars (Aurora and Savinjski golding) were exposed to progressive drought in a pot experiment and analysed at different stress stages (mild, moderate and severe). Measurements of relative water content revealed a hydrostable water balance of hop. Photosynthesis was decreased due to stomatal and non-stomatal limitation to the same extent in both cultivars. Of 28 identified differentially abundant proteins, the majority were down regulated and included in photosynthetic (41%) and sugar metabolism (33%). Fifteen % of identified proteins were classified into the nitrogen metabolism, 4% were related to a ROS related pathway and 7% to other functions. Copyright © 2016. Published by Elsevier Masson SAS.
Safety Needs Mediate Stressful Events Induced Mental Disorders

PubMed Central

Gu, Simeng; Lei, Yu; Lu, Shanshan

2016-01-01

“Safety first,” we say these words almost every day, but we all take this for granted for what Maslow proposed in his famous theory of Hierarchy of Needs: safety needs come second to physiological needs. Here we propose that safety needs come before physiological needs. Safety needs are personal security, financial security, and health and well-being, which are more fundamental than physiological needs. Safety worrying is the major reason for mental disorders, such as anxiety, phobia, depression, and PTSD. The neural basis for safety is amygdala, LC/NE system, and corticotrophin-releasing hormone system, which can be regarded as a “safety circuitry,” whose major behavior function is “fight or flight” and “fear and anger” emotions. This is similar to the Appraisal theory for emotions: fear is due to the primary appraisal, which is related to safety of individual, while anger is due to secondary appraisal, which is related to coping with the unsafe situations. If coping is good, the individual will be happy; if coping failed, the individual will be sad or depressed. PMID:27738527
Putative roles of neuropeptides in vagal afferent signaling

PubMed Central

de Lartigue, Guillaume

2014-01-01

The vagus nerve is a major pathway by which information is communicated between the brain and peripheral organs. Sensory neurons of the vagus are located in the nodose ganglia. These vagal afferent neurons innervate the heart, the lung and the gastrointestinal tract, and convey information about peripheral signals to the brain important in the control of cardiovascular tone, respiratory tone, and satiation, respectively. Glutamate is thought to be the primary neurotransmitter involved in conveying all of this information to the brain. It remains unclear how a single neurotransmitter can regulate such an extensive list of physiological functions from a wide range of visceral sites. Many neurotransmitters have been identified in vagal afferent neurons and have been suggested to modulate the physiological functions of glutamate. Specifically, the anorectic peptide transmitters, cocaine and amphetamine regulated transcript (CART) and the orexigenic peptide transmitters, melanin concentrating hormone (MCH) are differentially regulated in vagal afferent neurons and have opposing effects on food intake. Using these two peptides as a model, this review will discuss the potential role of peptide transmitters in providing a more precise and refined modulatory control of the broad physiological functions of glutamate, especially in relation to the control of feeding. PMID:24650553
The Physiology of Protein S-acylation

PubMed Central

Chamberlain, Luke H.; Shipston, Michael J.

2015-01-01

Protein S-acylation, the only fully reversible posttranslational lipid modification of proteins, is emerging as a ubiquitous mechanism to control the properties and function of a diverse array of proteins and consequently physiological processes. S-acylation results from the enzymatic addition of long-chain lipids, most typically palmitate, onto intracellular cysteine residues of soluble and transmembrane proteins via a labile thioester linkage. Addition of lipid results in increases in protein hydrophobicity that can impact on protein structure, assembly, maturation, trafficking, and function. The recent explosion in global S-acylation (palmitoyl) proteomic profiling as a result of improved biochemical tools to assay S-acylation, in conjunction with the recent identification of enzymes that control protein S-acylation and de-acylation, has opened a new vista into the physiological function of S-acylation. This review introduces key features of S-acylation and tools to interrogate this process, and highlights the eclectic array of proteins regulated including membrane receptors, ion channels and transporters, enzymes and kinases, signaling adapters and chaperones, cell adhesion, and structural proteins. We highlight recent findings correlating disruption of S-acylation to pathophysiology and disease and discuss some of the major challenges and opportunities in this rapidly expanding field. PMID:25834228
Novel metabolic and physiological functions of branched chain amino acids: a review.

PubMed

Zhang, Shihai; Zeng, Xiangfang; Ren, Man; Mao, Xiangbing; Qiao, Shiyan

2017-01-01

It is widely known that branched chain amino acids (BCAA) are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA (isoleucine, leucine and valine) regulate many key signaling pathways, the most classic of which is the activation of the mTOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including: (1) Insufficient or excessive levels of BCAA in the diet enhances lipolysis. (2) BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters. (3) Supplementation of leucine in the diet enhances meat quality in finishing pigs. (4) BCAA are beneficial for mammary health, milk quality and embryo growth. (5) BCAA enhance intestinal development, intestinal amino acid transportation and mucin production. (6) BCAA participate in up-regulating innate and adaptive immune responses. In addition, abnormally elevated BCAA levels in the blood (decreased BCAA catabolism) are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA.
Therapeutic Potential of Metabotropic Glutamate Receptor Modulators

PubMed Central

Hovelsø, N; Sotty, F; Montezinho, L.P; Pinheiro, P.S; Herrik, K.F; Mørk, A

2012-01-01

Glutamate is the main excitatory neurotransmitter in the central nervous system (CNS) and is a major player in complex brain functions. Glutamatergic transmission is primarily mediated by ionotropic glutamate receptors, which include NMDA, AMPA and kainate receptors. However, glutamate exerts modulatory actions through a family of metabotropic G-protein-coupled glutamate receptors (mGluRs). Dysfunctions of glutamatergic neurotransmission have been implicated in the etiology of several diseases. Therefore, pharmacological modulation of ionotropic glutamate receptors has been widely investigated as a potential therapeutic strategy for the treatment of several disorders associated with glutamatergic dysfunction. However, blockade of ionotropic glutamate receptors might be accompanied by severe side effects due to their vital role in many important physiological functions. A different strategy aimed at pharmacologically interfering with mGluR function has recently gained interest. Many subtype selective agonists and antagonists have been identified and widely used in preclinical studies as an attempt to elucidate the role of specific mGluRs subtypes in glutamatergic transmission. These studies have allowed linkage between specific subtypes and various physiological functions and more importantly to pathological states. This article reviews the currently available knowledge regarding the therapeutic potential of targeting mGluRs in the treatment of several CNS disorders, including schizophrenia, addiction, major depressive disorder and anxiety, Fragile X Syndrome, Parkinson’s disease, Alzheimer’s disease and pain. PMID:22942876
Zinc and Wound Healing: A Review of Zinc Physiology and Clinical Applications.

PubMed

Kogan, Samuel; Sood, Aditya; Garnick, Mark S

2017-04-01

Our understanding of the role of zinc in normal human physiology is constantly expanding, yet there are major gaps in our knowledge with regard to the function of zinc in wound healing. This review aims to provide the clinician with sufficient understanding of zinc biology and an up-to-date perspective on the role of zinc in wound healing. Zinc is an essential ion that is crucial for maintenance of normal physiology, and zinc deficiency has many manifestations ranging from delayed wound healing to immune dysfunction and impairment of multiple sensory systems. While consensus has been reached regarding the detrimental effects of zinc deficiency on wound healing, there is considerable discord in the literature on the optimal methods and true benefits of zinc supplementation.
Placenta-on-a-chip: a novel platform to study the biology of the human placenta.

PubMed

Lee, Ji Soo; Romero, Roberto; Han, Yu Mi; Kim, Hee Chan; Kim, Chong Jai; Hong, Joon-Seok; Huh, Dongeun

2016-01-01

Studying the biology of the human placenta represents a major experimental challenge. Although conventional cell culture techniques have been used to study different types of placenta-derived cells, current in vitro models have limitations in recapitulating organ-specific structure and key physiological functions of the placenta. Here we demonstrate that it is possible to leverage microfluidic and microfabrication technologies to develop a microengineered biomimetic model that replicates the architecture and function of the placenta. A "Placenta-on-a-Chip" microdevice was created by using a set of soft elastomer-based microfabrication techniques known as soft lithography. This microsystem consisted of two polydimethylsiloxane (PDMS) microfluidic channels separated by a thin extracellular matrix (ECM) membrane. To reproduce the placental barrier in this model, human trophoblasts (JEG-3) and human umbilical vein endothelial cells (HUVECs) were seeded onto the opposite sides of the ECM membrane and cultured under dynamic flow conditions to form confluent epithelial and endothelial layers in close apposition. We tested the physiological function of the microengineered placental barrier by measuring glucose transport across the trophoblast-endothelial interface over time. The permeability of the barrier study was analyzed and compared to that obtained from acellular devices and additional control groups that contained epithelial or endothelial layers alone. Our microfluidic cell culture system provided a tightly controlled fluidic environment conducive to the proliferation and maintenance of JEG-3 trophoblasts and HUVECs on the ECM scaffold. Prolonged culture in this model produced confluent cellular monolayers on the intervening membrane that together formed the placental barrier. This in vivo-like microarchitecture was also critical for creating a physiologically relevant effective barrier to glucose transport. Quantitative investigation of barrier function was conducted by calculating permeability coefficients and metabolic rates in varying conditions of barrier structure. The rates of glucose transport and metabolism were consistent with previously reported in vivo observations. The "Placenta-on-a-Chip" microdevice described herein provides new opportunities to simulate and analyze critical physiological responses of the placental barrier. This system may be used to address the major limitations of existing placenta model systems and serve to enable research platforms for reproductive biology and medicine.
Store-Operated Calcium Channels

PubMed Central

Lewis, Richard S.

2015-01-01

Store-operated calcium channels (SOCs) are a major pathway for calcium signaling in virtually all metozoan cells and serve a wide variety of functions ranging from gene expression, motility, and secretion to tissue and organ development and the immune response. SOCs are activated by the depletion of Ca2+ from the endoplasmic reticulum (ER), triggered physiologically through stimulation of a diverse set of surface receptors. Over 15 years after the first characterization of SOCs through electrophysiology, the identification of the STIM proteins as ER Ca2+ sensors and the Orai proteins as store-operated channels has enabled rapid progress in understanding the unique mechanism of store-operate calcium entry (SOCE). Depletion of Ca2+ from the ER causes STIM to accumulate at ER-plasma membrane (PM) junctions where it traps and activates Orai channels diffusing in the closely apposed PM. Mutagenesis studies combined with recent structural insights about STIM and Orai proteins are now beginning to reveal the molecular underpinnings of these choreographic events. This review describes the major experimental advances underlying our current understanding of how ER Ca2+ depletion is coupled to the activation of SOCs. Particular emphasis is placed on the molecular mechanisms of STIM and Orai activation, Orai channel properties, modulation of STIM and Orai function, pharmacological inhibitors of SOCE, and the functions of STIM and Orai in physiology and disease. PMID:26400989
Digestive Organ in the Female Reproductive Tract Borrows Genes from Multiple Organ Systems to Adopt Critical Functions

PubMed Central

Meslin, Camille; Plakke, Melissa S.; Deutsch, Aaron B.; Small, Brandon S.; Morehouse, Nathan I.; Clark, Nathan L.

2015-01-01

Persistent adaptive challenges are often met with the evolution of novel physiological traits. Although there are specific examples of single genes providing new physiological functions, studies on the origin of complex organ functions are lacking. One such derived set of complex functions is found in the Lepidopteran bursa copulatrix, an organ within the female reproductive tract that digests nutrients from the male ejaculate or spermatophore. Here, we characterized bursa physiology and the evolutionary mechanisms by which it was equipped with digestive and absorptive functionality. By studying the transcriptome of the bursa and eight other tissues, we revealed a suite of highly expressed and secreted gene products providing the bursa with a combination of stomach-like traits for mechanical and enzymatic digestion of the male spermatophore. By subsequently placing these bursa genes in an evolutionary framework, we found that the vast majority of their novel digestive functions were co-opted by borrowing genes that continue to be expressed in nonreproductive tissues. However, a number of bursa-specific genes have also arisen, some of which represent unique gene families restricted to Lepidoptera and may provide novel bursa-specific functions. This pattern of promiscuous gene borrowing and relatively infrequent evolution of tissue-specific duplicates stands in contrast to studies of the evolution of novelty via single gene co-option. Our results suggest that the evolution of complex organ-level phenotypes may often be enabled (and subsequently constrained) by changes in tissue specificity that allow expression of existing genes in novel contexts, such as reproduction. The extent to which the selective pressures encountered in these novel roles require resolution via duplication and sub/neofunctionalization is likely to be determined by the need for specialized reproductive functionality. Thus, complex physiological phenotypes such as that found in the bursa offer important opportunities for understanding the relative role of pleiotropy and specialization in adaptive evolution. PMID:25725432
Organ fusion and defective cuticle function in a lacs1 lacs2 double mutant of Arabidopsis

USDA-ARS?s Scientific Manuscript database

As the outermost layer on aerial tissues of the primary plant body, the cuticle plays important roles in plant development and physiology. The major components of the cuticle are cutin and cuticular wax, both of which are composed primarily of fatty acid derivatives synthesized in the epidermal cell...
Physiological changes associated with routine nursing procedures in critically ill are common: an observational pilot study.

PubMed

Engström, J; Bruno, E; Reinius, H; Fröjd, C; Jonsson, H; Sannervik, J; Larsson, A

2017-01-01

Nursing procedures that are routinely performed in the intensive care unit (ICU) are assumed to have minimal side effects. However, these procedures may sometimes cause physiological changes that negatively affect the patient. We hypothesized that physiological changes associated with routine nursing procedures in the ICU are common. A clinical observational study of 16 critically ill patients in a nine-bed mixed university hospital ICU. All nursing procedures were observed, and physiological data were collected and subsequently analyzed. Minor physiological changes were defined as minimal changes in respiratory or circulatory variables, and major physiological changes were marked as hyper/hypotension, bradycardia/tachycardia, bradypnea/tachypnea, ventilatory distress, and peripheral blood oxygen desaturation. In the 16 patients, 668 procedures generated 158 major and 692 minor physiological changes during 187 observational hours. The most common procedure was patient position change, which also generated the majority of the physiological changes. The most common major physiological changes were blood oxygen desaturation, ventilatory distress, and hypotension, and the most common minor changes were arterial pressure alteration, coughing, and increase in respiratory rate. In this pilot study, we examined physiological changes in connection with all regular routine nursing procedures in the ICU. We found that physiological changes were common and sometimes severe. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.
The Burmese python genome reveals the molecular basis for extreme adaptation in snakes

PubMed Central

Castoe, Todd A.; de Koning, A. P. Jason; Hall, Kathryn T.; Card, Daren C.; Schield, Drew R.; Fujita, Matthew K.; Ruggiero, Robert P.; Degner, Jack F.; Daza, Juan M.; Gu, Wanjun; Reyes-Velasco, Jacobo; Shaney, Kyle J.; Castoe, Jill M.; Fox, Samuel E.; Poole, Alex W.; Polanco, Daniel; Dobry, Jason; Vandewege, Michael W.; Li, Qing; Schott, Ryan K.; Kapusta, Aurélie; Minx, Patrick; Feschotte, Cédric; Uetz, Peter; Ray, David A.; Hoffmann, Federico G.; Bogden, Robert; Smith, Eric N.; Chang, Belinda S. W.; Vonk, Freek J.; Casewell, Nicholas R.; Henkel, Christiaan V.; Richardson, Michael K.; Mackessy, Stephen P.; Bronikowski, Anne M.; Yandell, Mark; Warren, Wesley C.; Secor, Stephen M.; Pollock, David D.

2013-01-01

Snakes possess many extreme morphological and physiological adaptations. Identification of the molecular basis of these traits can provide novel understanding for vertebrate biology and medicine. Here, we study snake biology using the genome sequence of the Burmese python (Python molurus bivittatus), a model of extreme physiological and metabolic adaptation. We compare the python and king cobra genomes along with genomic samples from other snakes and perform transcriptome analysis to gain insights into the extreme phenotypes of the python. We discovered rapid and massive transcriptional responses in multiple organ systems that occur on feeding and coordinate major changes in organ size and function. Intriguingly, the homologs of these genes in humans are associated with metabolism, development, and pathology. We also found that many snake metabolic genes have undergone positive selection, which together with the rapid evolution of mitochondrial proteins, provides evidence for extensive adaptive redesign of snake metabolic pathways. Additional evidence for molecular adaptation and gene family expansions and contractions is associated with major physiological and phenotypic adaptations in snakes; genes involved are related to cell cycle, development, lungs, eyes, heart, intestine, and skeletal structure, including GRB2-associated binding protein 1, SSH, WNT16, and bone morphogenetic protein 7. Finally, changes in repetitive DNA content, guanine-cytosine isochore structure, and nucleotide substitution rates indicate major shifts in the structure and evolution of snake genomes compared with other amniotes. Phenotypic and physiological novelty in snakes seems to be driven by system-wide coordination of protein adaptation, gene expression, and changes in the structure of the genome. PMID:24297902
The Burmese python genome reveals the molecular basis for extreme adaptation in snakes.

PubMed

Castoe, Todd A; de Koning, A P Jason; Hall, Kathryn T; Card, Daren C; Schield, Drew R; Fujita, Matthew K; Ruggiero, Robert P; Degner, Jack F; Daza, Juan M; Gu, Wanjun; Reyes-Velasco, Jacobo; Shaney, Kyle J; Castoe, Jill M; Fox, Samuel E; Poole, Alex W; Polanco, Daniel; Dobry, Jason; Vandewege, Michael W; Li, Qing; Schott, Ryan K; Kapusta, Aurélie; Minx, Patrick; Feschotte, Cédric; Uetz, Peter; Ray, David A; Hoffmann, Federico G; Bogden, Robert; Smith, Eric N; Chang, Belinda S W; Vonk, Freek J; Casewell, Nicholas R; Henkel, Christiaan V; Richardson, Michael K; Mackessy, Stephen P; Bronikowski, Anne M; Bronikowsi, Anne M; Yandell, Mark; Warren, Wesley C; Secor, Stephen M; Pollock, David D

2013-12-17

Snakes possess many extreme morphological and physiological adaptations. Identification of the molecular basis of these traits can provide novel understanding for vertebrate biology and medicine. Here, we study snake biology using the genome sequence of the Burmese python (Python molurus bivittatus), a model of extreme physiological and metabolic adaptation. We compare the python and king cobra genomes along with genomic samples from other snakes and perform transcriptome analysis to gain insights into the extreme phenotypes of the python. We discovered rapid and massive transcriptional responses in multiple organ systems that occur on feeding and coordinate major changes in organ size and function. Intriguingly, the homologs of these genes in humans are associated with metabolism, development, and pathology. We also found that many snake metabolic genes have undergone positive selection, which together with the rapid evolution of mitochondrial proteins, provides evidence for extensive adaptive redesign of snake metabolic pathways. Additional evidence for molecular adaptation and gene family expansions and contractions is associated with major physiological and phenotypic adaptations in snakes; genes involved are related to cell cycle, development, lungs, eyes, heart, intestine, and skeletal structure, including GRB2-associated binding protein 1, SSH, WNT16, and bone morphogenetic protein 7. Finally, changes in repetitive DNA content, guanine-cytosine isochore structure, and nucleotide substitution rates indicate major shifts in the structure and evolution of snake genomes compared with other amniotes. Phenotypic and physiological novelty in snakes seems to be driven by system-wide coordination of protein adaptation, gene expression, and changes in the structure of the genome.
French research program on the physiological problems caused by weightlessness. Use of the primate model

NASA Astrophysics Data System (ADS)

Pesquies, P. C.; Milhaud, C.; Nogues, C.; Klein, M.; Cailler, B.; Bost, R.

The need to acquire a better knowledge of the main biological problems induced by microgravity implies—in addition to human experimentation—the use of animal models, and primates seem to be particularly well adapted to this type of research. The major areas of investigation to be considered are the phospho-calcium metabolism and the metabolism of supporting tissues, the hydroelectrolytic metabolism, the cardiovascular function, awakeness, sleep-awakeness cycles, the physiology of equilibrium and the pathophysiology of space sickness. Considering this program, the Centre d'Etudes et de Recherches de Medecine Aerospatiale, under the sponsorship of the Centre National d'Etudes Spatiales, developed both a program of research on restrained primates for the French-U.S. space cooperation (Spacelab program) and for the French-Soviet space cooperation (Bio-cosmos program), and simulation of the effects of microgravity by head-down bedrest. Its major characteristics are discussed in the study.
Translational neurocardiology: preclinical models and cardioneural integrative aspects.

PubMed

Ardell, J L; Andresen, M C; Armour, J A; Billman, G E; Chen, P-S; Foreman, R D; Herring, N; O'Leary, D S; Sabbah, H N; Schultz, H D; Sunagawa, K; Zucker, I H

2016-07-15

Neuronal elements distributed throughout the cardiac nervous system, from the level of the insular cortex to the intrinsic cardiac nervous system, are in constant communication with one another to ensure that cardiac output matches the dynamic process of regional blood flow demand. Neural elements in their various 'levels' become differentially recruited in the transduction of sensory inputs arising from the heart, major vessels, other visceral organs and somatic structures to optimize neuronal coordination of regional cardiac function. This White Paper will review the relevant aspects of the structural and functional organization for autonomic control of the heart in normal conditions, how these systems remodel/adapt during cardiac disease, and finally how such knowledge can be leveraged in the evolving realm of autonomic regulation therapy for cardiac therapeutics. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.
Systemic localization of seven major types of carbohydrates on cell membranes by dSTORM imaging.

PubMed

Chen, Junling; Gao, Jing; Zhang, Min; Cai, Mingjun; Xu, Haijiao; Jiang, Junguang; Tian, Zhiyuan; Wang, Hongda

2016-07-25

Carbohydrates on the cell surface control intercellular interactions and play a vital role in various physiological processes. However, their systemic distribution patterns are poorly understood. Through the direct stochastic optical reconstruction microscopy (dSTORM) strategy, we systematically revealed that several types of representative carbohydrates are found in clustered states. Interestingly, the results from dual-color dSTORM imaging indicate that these carbohydrate clusters are prone to connect with one another and eventually form conjoined platforms where different functional glycoproteins aggregate (e.g., epidermal growth factor receptor, (EGFR) and band 3 protein). A thorough understanding of the ensemble distribution of carbohydrates on the cell surface paves the way for elucidating the structure-function relationship of cell membranes and the critical roles of carbohydrates in various physiological and pathological cell processes.

Systemic localization of seven major types of carbohydrates on cell membranes by dSTORM imaging

PubMed Central

Chen, Junling; Gao, Jing; Zhang, Min; Cai, Mingjun; Xu, Haijiao; Jiang, Junguang; Tian, Zhiyuan; Wang, Hongda

2016-01-01

Carbohydrates on the cell surface control intercellular interactions and play a vital role in various physiological processes. However, their systemic distribution patterns are poorly understood. Through the direct stochastic optical reconstruction microscopy (dSTORM) strategy, we systematically revealed that several types of representative carbohydrates are found in clustered states. Interestingly, the results from dual-color dSTORM imaging indicate that these carbohydrate clusters are prone to connect with one another and eventually form conjoined platforms where different functional glycoproteins aggregate (e.g., epidermal growth factor receptor, (EGFR) and band 3 protein). A thorough understanding of the ensemble distribution of carbohydrates on the cell surface paves the way for elucidating the structure-function relationship of cell membranes and the critical roles of carbohydrates in various physiological and pathological cell processes. PMID:27453176
Biomarkers of Aging: From Function to Molecular Biology

PubMed Central

Wagner, Karl-Heinz; Cameron-Smith, David; Wessner, Barbara; Franzke, Bernhard

2016-01-01

Aging is a major risk factor for most chronic diseases and functional impairments. Within a homogeneous age sample there is a considerable variation in the extent of disease and functional impairment risk, revealing a need for valid biomarkers to aid in characterizing the complex aging processes. The identification of biomarkers is further complicated by the diversity of biological living situations, lifestyle activities and medical treatments. Thus, there has been no identification of a single biomarker or gold standard tool that can monitor successful or healthy aging. Within this short review the current knowledge of putative biomarkers is presented, focusing on their application to the major physiological mechanisms affected by the aging process including physical capability, nutritional status, body composition, endocrine and immune function. This review emphasizes molecular and DNA-based biomarkers, as well as recent advances in other biomarkers such as microRNAs, bilirubin or advanced glycation end products. PMID:27271660
Differential roles of NADPH oxidases in vascular physiology and pathophysiology

PubMed Central

Amanso, Angelica M.; Griendling, Kathy K.

2012-01-01

Reactive oxygen species (ROS) are produced by all vascular cells and regulate the major physiological functions of the vasculature. Production and removal of ROS are tightly controlled and occur in discrete subcellular locations, allowing for specific, compartmentalized signaling. Among the many sources of ROS in the vessel wall, NADPH oxidases are implicated in physiological functions such as control of vasomotor tone, regulation of extracellular matrix and phenotypic modulation of vascular smooth muscle cells. They are involved in the response to injury, whether as an oxygen sensor during hypoxia, as a regulator of protein processing, as an angiogenic stimulus, or as a mechanism of wound healing. These enzymes have also been linked to processes leading to disease development, including migration, proliferation, hypertrophy, apoptosis and autophagy. As a result, NADPH oxidases participate in atherogenesis, systemic and pulmonary hypertension and diabetic vascular disease. The role of ROS in each of these processes and diseases is complex, and a more full understanding of the sources, targets, cell-specific responses and counterbalancing mechanisms is critical for the rational development of future therapeutics. PMID:22202108
Physiology of bile secretion.

PubMed

Esteller, Alejandro

2008-10-07

The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment, in different situations, results in the syndrome of cholestasis. The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed. Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane. This review summarizes recent data on the molecular determinants of this primary bile formation. The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bile-duct epithelial cells (cholangiocytes) as bile passes through bile ducts. The mechanisms of fluid and solute transport in cholangiocytes will also be discussed. In contrast to hepatocytes where secretion is constant and poorly controlled, cholangiocyte secretion is regulated by hormones and nerves. A short section dedicated to these regulatory mechanisms of bile secretion has been included. The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.
Modulation of Intestinal Paracellular Transport by Bacterial Pathogens.

PubMed

Roxas, Jennifer Lising; Viswanathan, V K

2018-03-25

The passive and regulated movement of ions, solutes, and water via spaces between cells of the epithelial monolayer plays a critical role in the normal intestinal functioning. This paracellular pathway displays a high level of structural and functional specialization, with the membrane-spanning complexes of the tight junctions, adherens junctions, and desmosomes ensuring its integrity. Tight junction proteins, like occludin, tricellulin, and the claudin family isoforms, play prominent roles as barriers to unrestricted paracellular transport. The past decade has witnessed major advances in our understanding of the architecture and function of epithelial tight junctions. While it has been long appreciated that microbes, notably bacterial and viral pathogens, target and disrupt junctional complexes and alter paracellular permeability, the precise mechanisms remain to be defined. Notably, renewed efforts will be required to interpret the available data on pathogen-mediated barrier disruption in the context of the most recent findings on tight junction structure and function. While much of the focus has been on pathogen-induced dysregulation of junctional complexes, commensal microbiota and their products may influence paracellular permeability and contribute to the normal physiology of the gut. Finally, microbes and their products have become important tools in exploring host systems, including the junctional properties of epithelial cells. © 2018 American Physiological Society. Compr Physiol 8:823-842, 2018. Copyright © 2018 American Physiological Society. All rights reserved.
Systems analysis in Cellvibrio japonicus resolves predicted redundancy of β-glucosidases and determines essential physiological functions: Functional analysis of C. japonicus β-glucosidases

DOE PAGES

Nelson, Cassandra E.; Rogowski, Artur; Morland, Carl; ...

2017-02-28

Degradation of polysaccharides forms an essential arc in the carbon cycle, provides a percentage of our daily caloric intake, and is a major driver in the renewable chemical industry. Microorganisms proficient at degrading insoluble polysaccharides possess large numbers of carbohydrate active enzymes, many of which have been categorized as functionally redundant. Here we present data that suggests that carbohydrate active enzymes that have overlapping enzymatic activities can have unique, non-overlapping biological functions in the cell. Our comprehensive study to understand cellodextrin utilization in the soil saprophyte Cellvibrio japonicus found that only one of four predicted β-glucosidases is required in amore » physiological context. Gene deletion analysis indicated that only the cel3B gene product is essential for efficient cellodextrin utilization in C. japonicus and is constitutively expressed at high levels. Interestingly, expression of individual β-glucosidases in Escherichia coli K-12 enabled this non-cellulolytic bacterium to be fully capable of using cellobiose as a sole carbon source. Furthermore, enzyme kinetic studies indicated that the Cel3A enzyme is significantly more active than the Cel3B enzyme on the oligosaccharides but not disaccharides. Finally, our approach for parsing related carbohydrate active enzymes to determine actual physiological roles in the cell can be applied to other polysaccharide-degradation systems.« less
THE REGULATION ROLE OF CAROTID BODY PERIPHERAL CHEMORECEPTORS IN PHYSIOLOGICAL AND PATHOPHYSIOLOGICAL CONDITIONS.

PubMed

Lazovic, Biljana; Zlatkovic Svenda, Mirjana; Durmic, Tijana; Stajic, Zoran; Duric, Vesna; Zugic, Vladimir

2016-11-01

The major oxygen sensors in the human body are peripheral chemoreceptors. also known as interoreceptors- as connected with internal organs, located in the aortic arch and in the body of the common carotid artery. Chemoreceptor function under physiological conditions. Stimulation of peripheral chemoreceptors during enviromental hypoxia causes a reflex-mediated increased ventilation, followed by the increase of the muscle sympatic activity, aiming to maintain tissue oxygen homeostatis, as well as glucosae, homeostatis. Besides that, peripheral chemoreceptors interact with central chemoreceptors. responsible for carbon dioxide changes . and they are able to modulate each other. Chemoreceptor function in pathophysiological conditions. Investigations of respiratory function in many pathological processes, such as hypertension, obstructive sleep apnea, congestive heart failure and many other diseases that are presented with enhanced peripheral chemosensitivity and impaired functional sy mpatholysis ultimately determine the peripheral chemorcceptor role and significance of peripheral chemoreceptors in the process of those pathological conditions development. Considering this, the presumed influence of peripheral chemoreceptors is important in patients having the above mentioned pathology. The importance and the role of peripheral chemoreceptors in the course of the breathing control is still controversial, despite many scientific attempts to solve this problem. The main objective of this review is to give the latest data on the peripheral chemoreceptor role and to highlight the importance of peripheral chemoreceptors for maintaining of oxygen homeostasis in pateints with hypoxia caused by either physiological or pathological conditions.
Morphological and physiological divergences within Quercus ilex support the existence of different ecotypes depending on climatic dryness

PubMed Central

Peguero-Pina, José Javier; Sancho-Knapik, Domingo; Barrón, Eduardo; Camarero, Julio Jesús; Vilagrosa, Alberto; Gil-Pelegrín, Eustaquio

2014-01-01

Background and Aims Several studies show apparently contradictory findings about the functional convergence within the Mediterranean woody flora. In this context, this study evaluates the variability of functional traits within holm oak (Quercus ilex) to elucidate whether provenances corresponding to different morphotypes represent different ecotypes locally adapted to the prevaling stress levels. Methods Several morphological and physiological traits were measured at leaf and shoot levels in 9-year-old seedlings of seven Q. ilex provenances including all recognized morphotypes. Plants were grown in a common garden for 9 years under the same environmental conditions to avoid possible biases due to site-specific characteristics. Key Results Leaf morphometry clearly separates holm oak provenances into ‘ilex’ (more elongated leaves with low vein density) and ‘rotundifolia’ (short and rounded leaves with high vein density) morphotypes. Moreover, these morphotypes represent two consistent and very contrasting functional types in response to dry climates, mainly in terms of leaf area, major vein density, leaf specific conductivity, resistance to drought-induced cavitation and turgor loss point. Conclusions The ‘ilex’ and ‘rotundifolia’ morphotypes correspond to different ecotypes as inferred from their contrasting functional traits. To the best of our knowledge, this is the first time that the combined use of morphological and physiological traits has provided support for the concept of these two holm oak morphotypes being regarded as two different species. PMID:24941998
Regulation of circadian blood pressure: from mice to astronauts.

PubMed

Agarwal, Rajiv

2010-01-01

Circadian variation is commonly seen in healthy people; aberration in these biological rhythms is an early sign of disease. Impaired circadian variation of blood pressure (BP) has been shown to be associated with greater target organ damage and with an elevated risk of cardiovascular events independent of the BP load. The purpose of this review is to examine the physiology of circadian BP variation and propose a tripartite model that explains the regulation of circadian BP. The time-keeper in mammals resides centrally in the suprachiasmatic nucleus. Apart from this central clock, molecular clocks exist in most peripheral tissues including vascular tissue and the kidney. These molecular clocks regulate sodium balance, sympathetic function and vascular tone. A physiological model is proposed that integrates our understanding of molecular clocks in mice with the circadian BP variation among humans. The master regulator in this proposed model is the sleep-activity cycle. The equivalents of peripheral clocks are endothelial and adrenergic functions. Thus, in the proposed model, the variation in circadian BP is dependent upon three major factors: physical activity, autonomic function, and sodium sensitivity. The integrated consideration of physical activity, autonomic function, and sodium sensitivity appears to explain the physiology of circadian BP variation and the pathophysiology of disrupted BP rhythms in various conditions and disease states. Our understanding of molecular clocks in mice may help to explain the provenance of blunted circadian BP variation even among astronauts.
In situ AFM imaging of apolipoprotein A-I directly derived from plasma HDL.

PubMed

Gan, Chaoye; Wang, Zhexuan; Chen, Yong

2017-04-01

The major apolipoproteins of plasma lipoproteins play vital roles in the structural integrity and physiological functions of lipoproteins. More than ten structural models of apolipoprotein A-I (apoA-I), the major apolipoprotein of high-density lipoprotein (HDL), have been developed successively. In these models, apoA-I was supposed to organize in a ring-shaped form. To date, however, there is no direct evidence under physiological condition. Here, atomic force microscopy (AFM) was used to in situ visualize the organization of apoA-I, which was exposed via depletion of the lipid component of plasma HDL pre-immobilized on functionalized mica sheets. For the first time, the ring-shaped coarse structure and three detailed structures (crescent-shaped, gapped "O"-shaped, and parentheses-shaped structures, respectively) of apoA-I in plasma HDL, which have the ability of binding scavenger receptors, were directly observed and quantitatively measured by AFM. The three detailed structures probably represent the different extents to which the lipid component of HDL was depleted. Data on lipid depletion of HDL may provide clues to understand lipid insertion of HDL. These data provide important information for the understanding of the structure/maturation of plasma HDL. Moreover, they suggest a powerful method for directly visualizing the major apolipoproteins of plasma lipoproteins or the protein component of lipoprotein-like lipid-protein complexes. Copyright © 2017 Elsevier B.V. All rights reserved.
The different role of sex hormones on female cardiovascular physiology and function: not only oestrogens.

PubMed

Salerni, Sara; Di Francescomarino, Samanta; Cadeddu, Christian; Acquistapace, Flavio; Maffei, Silvia; Gallina, Sabina

2015-06-01

Human response to different physiologic stimuli and cardiovascular (CV) adaptation to various pathologies seem to be gender specific. Sex-steroid hormones have been postulated as the major contributors towards these sex-related differences. This review will discuss current evidence on gender differences in CV function and remodelling, and will present the different role of the principal sex-steroid hormones on female heart. Starting from a review of sex hormones synthesis, receptors and CV signalling, we will summarize the current knowledge concerning the role of sex hormones on the regulation of our daily activities throughout the life, via the modulation of autonomic nervous system, excitation-contraction coupling pathway and ion channels activity. Many unresolved questions remain even if oestrogen effects on myocardial remodelling and function have been extensively studied. So this work will focus attention also on the controversial and complex relationship existing between androgens, progesterone and female heart. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.
Biological characters of bats in relation to natural reservoir of emerging viruses.

PubMed

Omatsu, Tsutomu; Watanabe, Shumpei; Akashi, Hiroomi; Yoshikawa, Yasuhiro

2007-09-01

Many investigators focused on bats (Chiroptera) for their specific character, i.e. echolocation system, phylogenic tree, food practice and unique reproduction. However, most of basic information about the vital functions related to anti-viral activity has been unclear. For evaluating some animals as a natural reservoir or host of infectious pathogens, it is necessary that not only their immune system but also their biology, the environment of their living, food habits and physiological features should be clarified and they should be analyzed from these multi-view points. The majority of current studies on infectious diseases have been conducted for the elucidation of viral virulence using experimental animals or viral gene function in vitro, but in a few case, researchers focused on wild animal itself. In this paper, we described basic information about bats as follows; genetic background, character of the immunological factors, histological character of immune organs, the physiological function and sensitivity of bat cells to viral infection.
The Musculoskeletal System. Instructional Materials in Anatomy and Physiology for Pennsylvania Health Occupations Programs.

ERIC Educational Resources Information Center

National Evaluation Systems, Inc., Amherst, MA.

This instructional modular unit with instructor's guide provides materials on aspects of one of the major systems of the human body--the musculoskeletal system. Its purpose is to introduce the student to the structures and functions of the human musculoskeletal system--and the interrelationships of the two--and to familiarize the student with some…
Protein accounting in the cellular economy.

PubMed

Vázquez-Laslop, Nora; Mankin, Alexander S

2014-04-24

Knowing the copy number of cellular proteins is critical for understanding cell physiology. By being able to measure the absolute synthesis rates of the majority of cellular proteins, Li et al. gain insights into key aspects of translation regulation and fundamental principles of cellular strategies to adjust protein synthesis according to the functional needs. Copyright © 2014 Elsevier Inc. All rights reserved.
The Circulatory System. Instructional Materials in Anatomy and Physiology for Pennsylvania Health Occupations Programs.

ERIC Educational Resources Information Center

National Evaluation Systems, Inc., Amherst, MA.

This instructional modular unit with instructor's guide provides materials on aspects of one of the major systems of the human body--the circulatory system. Its purpose is to introduce the student to the structures and functions of the human circulatory system--and the interrelationships of the two--and to familiarize the student with some of the…
The Respiratory System. Instructional Materials in Anatomy and Physiology for Pennsylvania Health Occupations Programs.

ERIC Educational Resources Information Center

National Evaluation Systems, Inc., Amherst, MA.

This instructional modular unit with instructor's guide provides materials on aspects of one of the major systems of the human body--the respiratory system. Its purpose is to introduce the student to the structures and functions of the human respiratory system--and the interrelationships of the two--and to famlliarize the student with some of the…
Major amyloid-β-degrading enzymes, endothelin-converting enzyme-2 and neprilysin, are expressed by distinct populations of GABAergic interneurons in hippocampus and neocortex.

PubMed

Pacheco-Quinto, Javier; Eckman, Christopher B; Eckman, Elizabeth A

2016-12-01

Impaired clearance of amyloid-β peptide (Aβ) has been postulated to significantly contribute to the amyloid accumulation typical of Alzheimer's disease. Among the enzymes known to degrade Aβ in vivo are endothelin-converting enzyme (ECE)-1, ECE-2, and neprilysin (NEP), and evidence suggests that they regulate independent pools of Aβ that may be functionally significant. To better understand the differential regulation of Aβ concentration by its physiological degrading enzymes, we characterized the cell and region-specific expression pattern of ECE-1, ECE-2, and NEP by in situ hybridization and immunohistochemistry in brain areas relevant to Alzheimer's disease. In contrast to the broader distribution of ECE-1, ECE-2 and NEP were found enriched in GABAergic neurons. ECE-2 was majorly expressed by somatostatin-expressing interneurons and was active in isolated synaptosomes. NEP messenger RNA was found mainly in parvalbumin-expressing interneurons, with NEP protein localized to perisomatic parvalbuminergic synapses. The identification of somatostatinergic and parvalbuminergic synapses as hubs for Aβ degradation is consistent with the possibility that Aβ may have a physiological function related to the regulation of inhibitory signaling. Copyright © 2016 Elsevier Inc. All rights reserved.
Physiologic measures of sexual function in women: a review.

PubMed

Woodard, Terri L; Diamond, Michael P

2009-07-01

To review and describe physiologic measures of assessing sexual function in women. Literature review. Studies that use instruments designed to measure female sexual function. Women participating in studies of female sexual function. Various instruments that measure physiologic features of female sexual function. Appraisal of the various instruments, including their advantages and disadvantages. Many unique physiologic methods of evaluating female sexual function have been developed during the past four decades. Each method has its benefits and limitations. Many physiologic methods exist, but most are not well-validated. In addition there has been an inability to correlate most physiologic measures with subjective measures of sexual arousal. Furthermore, given the complex nature of the sexual response in women, physiologic measures should be considered in context of other data, including the history, physical examination, and validated questionnaires. Nonetheless, the existence of appropriate physiologic measures is vital to our understanding of female sexual function and dysfunction.
The Plasma Membrane Calcium ATPases and Their Role as Major New Players in Human Disease.

PubMed

Stafford, Nicholas; Wilson, Claire; Oceandy, Delvac; Neyses, Ludwig; Cartwright, Elizabeth J

2017-07-01

The Ca 2+ extrusion function of the four mammalian isoforms of the plasma membrane calcium ATPases (PMCAs) is well established. There is also ever-increasing detail known of their roles in global and local Ca 2+ homeostasis and intracellular Ca 2+ signaling in a wide variety of cell types and tissues. It is becoming clear that the spatiotemporal patterns of expression of the PMCAs and the fact that their abundances and relative expression levels vary from cell type to cell type both reflect and impact on their specific functions in these cells. Over recent years it has become increasingly apparent that these genes have potentially significant roles in human health and disease, with PMCAs1-4 being associated with cardiovascular diseases, deafness, autism, ataxia, adenoma, and malarial resistance. This review will bring together evidence of the variety of tissue-specific functions of PMCAs and will highlight the roles these genes play in regulating normal physiological functions and the considerable impact the genes have on human disease. Copyright © 2017 the American Physiological Society.
Short-term exposure to mobile phone base station signals does not affect cognitive functioning or physiological measures in individuals who report sensitivity to electromagnetic fields and controls.

PubMed

Eltiti, Stacy; Wallace, Denise; Ridgewell, Anna; Zougkou, Konstantina; Russo, Riccardo; Sepulveda, Francisco; Fox, Elaine

2009-10-01

Individuals who report sensitivity to electromagnetic fields often report cognitive impairments that they believe are due to exposure to mobile phone technology. Previous research in this area has revealed mixed results, however, with the majority of research only testing control individuals. Two studies using control and self-reported sensitive participants found inconsistent effects of mobile phone base stations on cognitive functioning. The aim of the present study was to clarify whether short-term (50 min) exposure at 10 mW/m(2) to typical Global System for Mobile Communication (GSM) and Universal Mobile Telecommunications System (UMTS) base station signals affects attention, memory, and physiological endpoints in sensitive and control participants. Data from 44 sensitive and 44 matched-control participants who performed the digit symbol substitution task (DSST), digit span task (DS), and a mental arithmetic task (MA), while being exposed to GSM, UMTS, and sham signals under double-blind conditions were analyzed. Overall, cognitive functioning was not affected by short-term exposure to either GSM or UMTS signals in the current study. Nor did exposure affect the physiological measurements of blood volume pulse (BVP), heart rate (HR), and skin conductance (SC) that were taken while participants performed the cognitive tasks.

Intermediate filament proteins of digestive organs: physiology and pathophysiology.

PubMed

Omary, M Bishr

2017-06-01

Intermediate filament proteins (IFs), such as cytoplasmic keratins in epithelial cells and vimentin in mesenchymal cells and the nuclear lamins, make up one of the three major cytoskeletal protein families. Whether in digestive organs or other tissues, IFs share several unique features including stress-inducible overexpression, abundance, cell-selective and differentiation state expression, and association with >80 human diseases when mutated. Whereas most IF mutations cause disease, mutations in simple epithelial keratins 8, 18, or 19 or in lamin A/C predispose to liver disease with or without other tissue manifestations. Keratins serve major functions including protection from apoptosis, providing cellular and subcellular mechanical integrity, protein targeting to subcellular compartments, and scaffolding and regulation of cell-signaling processes. Keratins are essential for Mallory-Denk body aggregate formation that occurs in association with several liver diseases, whereas an alternate type of keratin and lamin aggregation occurs upon liver involvement in porphyria. IF-associated diseases have no known directed therapy, but high-throughput drug screening to identify potential therapies is an appealing ongoing approach. Despite the extensive current knowledge base, much remains to be discovered regarding IF physiology and pathophysiology in digestive and nondigestive organs. Copyright © 2017 the American Physiological Society.
Transcriptome Profile at Different Physiological Stages Reveals Potential Mode for Curly Fleece in Chinese Tan Sheep

PubMed Central

Liu, Yufang; Xu, Qinqin; Zhang, Ming; Fang, Meiying

2013-01-01

Tan sheep (Ovis aries), a Chinese indigenous breed, has special curly fleece after birth, especially at one month old. However, this unique phenotype disappears gradually with age and the underlying reasons of trait evolvement are still unknown. In this study, skin transcriptome data was used to study this issue. In total 51,215 transcripts including described transcripts and transfrags were identified. Pathway analysis of the top 100 most highly expressed transcripts, which included TCHH and keratin gene family members, such as KRT25, KRT5, KRT71, KRT14 and others, showed pathways known to be relevant to hair/fleece development and function. Six hundred differentially expressed (DE) transcripts were detected at two different physiological ages (one-month-old with curly fleece and 48-month-old without curly fleece) and were categorized into three major functional groups: cellular component, molecular function, and biological process. The top six functional categories included cell, cell part, cellular process, binding, intracellular, metabolic process. The detected differentially expressed genes were particularly involved in signal, signal peptide, disulfide bond, glycoprotein and secreted terms, respectively. Further splicing isoform analysis showed that the metallothionein 3 isoform was up-regulated in Tan lamb skin, indicating that it may be related to the conformation of curly fleece in Chinese Tan lamb. The hair-related important differentially expressed genes (SPINK4, FGF21, ESRα, EphA3, NTNG1 and GPR110) were confirmed by qPCR analysis. We deduced that the differences existed in expressed transcripts, splice isoforms and GO categories between the two different physiological stages, which might constitute the major reasons for explaining the trait evolvement of curly fleece in Chinese Tan sheep. This study provides some clues for elucidating the molecular mechanism of fleece change with age in Chinese Tan sheep, as well as supplying some potential values for understanding human hair disorder and texture changes. PMID:23990983
Recent findings in cardiovascular physiology with space travel.

PubMed

Hughson, Richard L

2009-10-01

The cardiovascular system undergoes major changes in stress with space flight primarily related to the elimination of the head-to-foot gravitational force. A major observation has been that the central venous pressure is not elevated early in space flight yet stroke volume is increased at least early in flight. Recent observations demonstrate that heart rate remains lower during the normal daily activities of space flight compared to Earth-based conditions. Structural and functional adaptations occur in the vascular system that could result in impaired response with demands of physical exertion and return to Earth. Cardiac muscle mass is reduced after flight and contractile function may be altered. Regular and specific countermeasures are essential to maintain cardiovascular health during long-duration space flight.
Evolution of the rodent eosinophil-associated RNase gene family by rapid gene sorting and positive selection

PubMed Central

Zhang, Jianzhi; Dyer, Kimberly D.; Rosenberg, Helene F.

2000-01-01

The mammalian RNase A superfamily comprises a diverse array of ribonucleolytic proteins that have a variety of biochemical activities and physiological functions. Two rapidly evolving RNases of higher primates are of particular interest as they are major secretory proteins of eosinophilic leukocytes and have been found to possess anti-pathogen activities in vitro. To understand how these RNases acquired this function during evolution and to develop animal models for the study of their functions in vivo, it is necessary to investigate these genes in many species. Here, we report the sequences of 38 functional genes and 23 pseudogenes of the eosinophil-associated RNase (EAR) family from 5 rodent species. Our phylogenetic analysis of these genes showed a clear pattern of evolution by a rapid birth-and-death process and gene sorting, a process characterized by rapid gene duplication and deactivation occurring differentially among lineages. This process ultimately generates distinct or only partially overlapping inventories of the genes, even in closely related species. Positive Darwinian selection also contributed to the diversification of these EAR genes. The striking similarity between the evolutionary patterns of the EAR genes and those of the major histocompatibility complex, immunoglobulin, and T cell receptor genes stands in strong support of the hypothesis that host-defense and generation of diversity are among the primary physiological function of the rodent EARs. The discovery of a large number of divergent EARs suggests the intriguing possibility that these proteins have been specifically tailored to fight against distinct rodent pathogens. PMID:10758160
Lipids: From Chemical Structures, Biosynthesis, and Analyses to Industrial Applications.

PubMed

Li-Beisson, Yonghua; Nakamura, Yuki; Harwood, John

2016-01-01

Lipids are one of the major subcellular components, and play numerous essential functions. As well as their physiological roles, oils stored in biomass are useful commodities for a variety of biotechnological applications including food, chemical feedstocks, and fuel. Due to their agronomic as well as economic and societal importance, lipids have historically been subjected to intensive studies. Major current efforts are to increase the energy density of cell biomass, and/or create designer oils suitable for specific applications. This chapter covers some basic aspects of what one needs to know about lipids: definition, structure, function, metabolism and focus is also given on the development of modern lipid analytical tools and major current engineering approaches for biotechnological applications. This introductory chapter is intended to serve as a primer for all subsequent chapters in this book outlining current development in specific areas of lipids and their metabolism.
Kallikreins - The melting pot of activity and function.

PubMed

Kalinska, Magdalena; Meyer-Hoffert, Ulf; Kantyka, Tomasz; Potempa, Jan

2016-03-01

The human tissue kallikrein and kallikrein-related peptidases (KLKs), encoded by the largest contiguous cluster of protease genes in the human genome, are secreted serine proteases with diverse expression patterns and physiological roles. Because of the broad spectrum of processes that are modulated by kallikreins, these proteases are the subject of extensive investigations. This review brings together basic information about the biochemical properties affecting enzymatic activity, with highlights on post-translational modifications, especially glycosylation. Additionally, we present the current state of knowledge regarding the physiological functions of KLKs in major human organs and outline recent discoveries pertinent to the involvement of kallikreins in cell signaling and in viral infections. Despite the current depth of knowledge of these enzymes, many questions regarding the roles of kallikreins in health and disease remain unanswered. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.
Listening to Another Sense: Somatosensory Integration in the Auditory System

PubMed Central

Wu, Calvin; Stefanescu, Roxana A.; Martel, David T.

2014-01-01

Conventionally, sensory systems are viewed as separate entities, each with its own physiological process serving a different purpose. However, many functions require integrative inputs from multiple sensory systems, and sensory intersection and convergence occur throughout the central nervous system. The neural processes for hearing perception undergo significant modulation by the two other major sensory systems, vision and somatosensation. This synthesis occurs at every level of the ascending auditory pathway: the cochlear nucleus, inferior colliculus, medial geniculate body, and the auditory cortex. In this review, we explore the process of multisensory integration from 1) anatomical (inputs and connections), 2) physiological (cellular responses), 3) functional, and 4) pathological aspects. We focus on the convergence between auditory and somatosensory inputs in each ascending auditory station. This review highlights the intricacy of sensory processing, and offers a multisensory perspective regarding the understanding of sensory disorders. PMID:25526698
Mammalian lipoxygenases and their biological relevance

PubMed Central

Kuhn, Hartmut; Banthiya, Swathi; van Leyen, Klaus

2015-01-01

Lipoxygenases (LOXs) form a heterogeneous class of lipid peroxidizing enzymes, which have been implicated in cell proliferation and differentiation but also in the pathogenesis of various diseases with major public health relevance. As other fatty acid dioxygenases LOX oxidize polyunsaturated fatty acids to their corresponding hydroperoxy derivatives, which are further transformed to bioactive lipid mediators (eicosanoids and related substances). On the other hand, lipoxygenases are key players in regulation of the cellular redox homeostasis, which is an important element in gene expression regulation. Although the first mammalian lipoxygenases were discovered 40 years ago and although the enzymes have been well characterized with respect to their structural and functional properties the biological roles of the different lipoxygenase isoforms are not completely understood. This review is aimed at summarizing the current knowledge on the physiological roles of different mammalian LOX-isoforms and their patho-physiological function in inflammatory, metabolic, hyperproliferative, neurodegenerative and infectious disorders. PMID:25316652
Avian genomics lends insights into endocrine function in birds.

PubMed

Mello, C V; Lovell, P V

2018-01-15

The genomics era has brought along the completed sequencing of a large number of bird genomes that cover a broad range of the avian phylogenetic tree (>30 orders), leading to major novel insights into avian biology and evolution. Among recent findings, the discovery that birds lack a large number of protein coding genes that are organized in highly conserved syntenic clusters in other vertebrates is very intriguing, given the physiological importance of many of these genes. A considerable number of them play prominent endocrine roles, suggesting that birds evolved compensatory genetic or physiological mechanisms that allowed them to survive and thrive in spite of these losses. While further studies are needed to establish the exact extent of avian gene losses, these findings point to birds as potentially highly relevant model organisms for exploring the genetic basis and possible therapeutic approaches for a wide range of endocrine functions and disorders. Copyright © 2017 Elsevier Inc. All rights reserved.
Ghrelin

PubMed Central

Wu, James T.; Kral, John G.

2004-01-01

Objective: Ghrelin is a novel gastric hormone recognized in 1999 as a mediator of growth hormone release. Since growth hormone is anabolic, an important function of ghrelin may be to coordinate energy needs with the growth process. Newly discovered biologic roles of ghrelin imply that it may have other important physiological functions as well. This is a review of recent clinically relevant, yet less well-known, physiologic actions of ghrelin. Summary Background Data: Ghrelin has profound orexigenic, adipogenic, and somatotrophic properties, increasing food intake and body weight. Secreted predominantly from the stomach, ghrelin is the natural ligand for the growth hormone secretagogue receptor in the pituitary gland, thus fulfilling criteria of a brain-gut peptide. The brain-gut axis is the effector of anabolism by regulating growth, feeding, and metabolism via vagal afferents mediating ghrelin signaling. However, the wide tissue distribution of ghrelin suggests that it may have other functions as well. Methods: Systematic literature review of all PubMed citations between 1999 and August 2003 focusing on clinically relevant biochemical and physiological characteristics of ghrelin. Results: Ghrelin is an important component of an integrated regulatory system of growth and metabolism acting via the vagus nerve, and is implicated in a variety of altered energy states such as obesity, eating disorders, neoplasia, and cachexia. It also enhances immune responses and potentially down-regulates anti-inflammatory molecules. Ghrelin's role as a brain-gut peptide emphasizes the significance of afferent vagal fibers as a major pathway to the brain, serving the purpose of maintaining physiologic homeostasis. Conclusions: The discovery of ghrelin has increased our understanding of feeding regulation, nutritional homeostasis, and metabolic processes. Further characterization of ghrelin's functions will likely generate new pharmacological approaches to diagnose and treat different disease entities including those related to the over-nutrition of obesity and the catabolic response to surgical trauma. PMID:15024307
Functional microorganisms for functional food quality.

PubMed

Gobbetti, M; Cagno, R Di; De Angelis, M

2010-09-01

Functional microorganisms and health benefits represent a binomial with great potential for fermented functional foods. The health benefits of fermented functional foods are expressed either directly through the interactions of ingested live microorganisms with the host (probiotic effect) or indirectly as the result of the ingestion of microbial metabolites synthesized during fermentation (biogenic effect). Since the importance of high viability for probiotic effect, two major options are currently pursued for improving it--to enhance bacterial stress response and to use alternative products for incorporating probiotics (e.g., ice cream, cheeses, cereals, fruit juices, vegetables, and soy beans). Further, it seems that quorum sensing signal molecules released by probiotics may interact with human epithelial cells from intestine thus modulating several physiological functions. Under optimal processing conditions, functional microorganisms contribute to food functionality through their enzyme portfolio and the release of metabolites. Overproduction of free amino acids and vitamins are two classical examples. Besides, bioactive compounds (e.g., peptides, γ-amino butyric acid, and conjugated linoleic acid) may be released during food processing above the physiological threshold and they may exert various in vivo health benefits. Functional microorganisms are even more used in novel strategies for decreasing phenomenon of food intolerance (e.g., gluten intolerance) and allergy. By a critical approach, this review will aim at showing the potential of functional microorganisms for the quality of functional foods.
Defining the Physiological Factors that Contribute to Postflight Changes in Functional Performance

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Arzeno, N.; Buxton, R.; Feiveson, A. H.; Kofman, I.; Lawrence, E.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts, S. H.;

2009-01-01

Astronauts experience alterations in multiple physiological systems due to exposure to the microgravity conditions of space flight. These physiological changes include sensorimotor disturbances, cardiovascular deconditioning and loss of muscle mass and strength. These changes might affect the ability of crewmembers to perform critical mission tasks immediately after landing on lunar and Martian surfaces. To date, changes in functional performance have not been systematically studied or correlated with physiological changes. To understand how changes in physiological function impact functional performance an interdisciplinary pre/postflight testing regimen (Functional Task Test, FTT) has been developed that systematically evaluates both astronaut postflight functional performance and related physiological changes. The overall objective of the FTT is to identify the key underlying physiological factors that contribute to performance of functional tests that are representative of critical mission tasks. This study will identify which physiological systems contribute the most to impaired performance on each functional test. This will allow us to identify the physiological systems that play the largest role in decrement in functional performance. Using this information we can then design and implement countermeasures that specifically target the physiological systems most responsible for the altered functional performance associated with space flight. The functional test battery was designed to address high priority tasks identified by the Constellation program as critical for mission success. The set of functional tests making up the FTT include the: 1) Seat Egress and Walk Test, 2) Ladder Climb Test, 3) Recovery from Fall/Stand Test, 4) Rock Translation Test, 5) Jump Down Test, 6) Torque Generation Test, and 7) Construction Activity Board Test. Corresponding physiological measures include assessments of postural and gait control, dynamic visual acuity, fine motor control, plasma volume, orthostatic intolerance, upper and lower body muscle strength, power, fatigue, control and neuromuscular drive. Crewmembers perform both functional and physiological tests before and after short (Shuttle) and long-duration (ISS) space flight. Data are collected on R+0 (Shuttle only), R+1, R+6 and R+30.

The Digestive System [and] Instructor's Guide. Instructional Materials in Anatomy and Physiology for Pennsylvania Health Occupations Programs.

ERIC Educational Resources Information Center

National Evaluation Systems, Inc., Amherst, MA.

This instructional modular unit wlth instructor's guide provides materials on important aspects of one of the major systems of the human body--the digestive system. Its purpose is to introduce the student to the structures and functions of the human digestive system--and the interrelationships of the two--and to familiarize the student with some…
Recent neuroimaging techniques in mild traumatic brain injury.

PubMed

Belanger, Heather G; Vanderploeg, Rodney D; Curtiss, Glenn; Warden, Deborah L

2007-01-01

Mild traumatic brain injury (TBI) is characterized by acute physiological changes that result in at least some acute cognitive difficulties and typically resolve by 3 months postinjury. Because the majority of mild TBI patients have normal structural magnetic resonance imaging (MRI)/computed tomography (CT) scans, there is increasing attention directed at finding objective physiological correlates of persistent cognitive and neuropsychiatric symptoms through experimental neuroimaging techniques. The authors review studies utilizing these techniques in patients with mild TBI; these techniques may provide more sensitive assessment of structural and functional abnormalities following mild TBI. Particular promise is evident with fMRI, PET, and SPECT scanning, as demonstrated by associations between brain activation and clinical outcomes.
Pathways of Polyunsaturated Fatty Acid Utilization: Implications for Brain Function in Neuropsychiatric Health and Disease

PubMed Central

Liu, Joanne J.; Green, Pnina; Mann, J. John; Rapoport, Stanley I.; Sublette, M. Elizabeth

2014-01-01

Essential polyunsaturated fatty acids (PUFAs) have profound effects on brain development and function. Abnormalities of PUFA status have been implicated in neuropsychiatric diseases such as major depression, bipolar disorder, schizophrenia, Alzheimer’s disease, and attention deficit hyperactivity disorder. Pathophysiologic mechanisms could involve not only suboptimal PUFA intake, but also metabolic and genetic abnormalities, defective hepatic metabolism, and problems with diffusion and transport. This article provides an overview of physiologic factors regulating PUFA utilization, highlighting their relevance to neuropsychiatric disease. PMID:25498862
The Formation and Function of Plant Cuticles1

PubMed Central

Yeats, Trevor H.; Rose, Jocelyn K.C.

2013-01-01

The plant cuticle is an extracellular hydrophobic layer that covers the aerial epidermis of all land plants, providing protection against desiccation and external environmental stresses. The past decade has seen considerable progress in assembling models for the biosynthesis of its two major components, the polymer cutin and cuticular waxes. Most recently, two breakthroughs in the long-sought molecular bases of alkane formation and polyester synthesis have allowed construction of nearly complete biosynthetic pathways for both waxes and cutin. Concurrently, a complex regulatory network controlling the synthesis of the cuticle is emerging. It has also become clear that the physiological role of the cuticle extends well beyond its primary function as a transpiration barrier, playing important roles in processes ranging from development to interaction with microbes. Here, we review recent progress in the biochemistry and molecular biology of cuticle synthesis and function and highlight some of the major questions that will drive future research in this field. PMID:23893170
Classification of genetic variation for cadmium tolerance in Bermudagrass [Cynodon dactylon (L.) Pers.] using physiological traits and molecular markers.

PubMed

Xie, Yan; Luo, Hongji; Hu, Longxing; Sun, Xiaoyan; Lou, Yanhong; Fu, Jinmin

2014-08-01

Cadmium (Cd) is one of the most toxic pollutants that caused severe threats to animal and human health. Bermudagrass is a dominant species in Cd contaminated soils, which can prevent Cd flow and spread. The objectives of this study were to determine the genetic variations in major physiological traits related to Cd tolerance in six populations of Bermudagrass collected from China, and to examine the genetic diversity and relationships among these accessions that vary in Cd tolerance using molecular markers. Plants of 120 accessions (116 natural accessions and 4 commercial cultivars) were exposed to 0 (i.e. control) or 1.5 mM CdSO4·8/3H2O for 3 weeks in hydroponic culture. Turf quality, transpiration rate, chlorophyll content, leaf water content and growth rate showed wide phenotypic variation. The membership function method was used to comprehensively evaluate Cd-tolerance. According to the average subordinate function value, four accessions were classified as the most tolerant genotypes and four accessions as Cd-sensitive genotypes. The trend of Cd tolerance among the six studied populations was as follows: Hunan > South China > North China > Central China > West South China and Xinjiang population. Phylogenetic analysis revealed that the majority of accessions from the same or adjacent regions were clustered into the same groups or subgroups, and the accessions with similar cadmium tolerance displayed a close phylogenetic relationship. Screening genetically diverse germplasm by combining the physiological traits and molecular markers could prove useful in developing Cd-tolerant Bermudagrass for the remediation of mill tailings and heavy metal polluted soils.
Cortical Activation in Response to Pure Taste Stimuli During the Physiological States of Hunger and Satiety

PubMed Central

Haase, Lori; Cerf-Ducastel, Barbara; Murphy, Claire

2009-01-01

This event-related functional magnetic resonance imaging (er-fMRI) study investigated BOLD signal change in response to a series of pure gustatory stimuli that varied in stimulus quality when subjects were hungry and sated with a nutritional preload. Group analyses showed significant differences in activation in the hunger minus satiety condition in response to sucrose, caffeine, saccharin, and citric acid within the thalamus, hippocampus, and parahippocampus. When examining the hunger and satiety conditions, activation varied as a function of stimulus, with the majority of the stimuli exhibiting significantly greater activation in the hunger state within the insula, thalamus, and substantia nigra, in contrast to decreased activation in the satiated state within the parahippocampus, hippocampus, amygdala, and anterior cingulate. Region of interest (ROI) analysis revealed two significant interactions, ROI by physiology and ROI by physiology by stimulus. In the satiety condition, the primary (inferior and superior insulae) and secondary (OFC 11 and OFC 47) taste regions exhibited significantly greater brain activation in response to all stimuli than regions involved in processing eating behavior (hypothalamus), affect (amygdala), and memory (hippocampus, parahippocampus and entorhinal cortex). These same regions demonstrated significantly greater activation within the hunger condition than the satiety condition, with the exception of the superior insula. Furthermore, the patterns of activation differed as a function taste stimulus, with greater activation in response to sucrose than to the other stimuli. These differential patterns of activation suggest that the physiological states of hunger and satiety produce divergent activation in multiple brain areas in response to different pure gustatory stimuli. PMID:19007893
New insights into globoids of protein storage vacuoles in wheat aleurone using synchrotron soft X-ray microscopy

PubMed Central

Regvar, Marjana; Eichert, Diane; Kaulich, Burkhard; Gianoncelli, Alessandra; Pongrac, Paula; Vogel-Mikuš, Katarina; Kreft, Ivan

2011-01-01

Mature developed seeds are physiologically and biochemically committed to store nutrients, principally as starch, protein, oils, and minerals. The composition and distribution of elements inside the aleurone cell layer reflect their biogenesis, structural characteristics, and physiological functions. It is therefore of primary importance to understand the mechanisms underlying metal ion accumulation, distribution, storage, and bioavailability in aleurone subcellular organelles for seed fortification purposes. Synchrotron radiation soft X-ray full-field imaging mode (FFIM) and low-energy X-ray fluorescence (LEXRF) spectromicroscopy were applied to characterize major structural features and the subcellular distribution of physiologically important elements (Zn, Fe, Na, Mg, Al, Si, and P). These direct imaging methods reveal the accumulation patterns between the apoplast and symplast, and highlight the importance of globoids with phytic acid mineral salts and walls as preferential storage structures. C, N, and O chemical topographies are directly linked to the structural backbone of plant substructures. Zn, Fe, Na, Mg, Al, and P were linked to globoid structures within protein storage vacuoles with variable levels of co-localization. Si distribution was atypical, being contained in the aleurone apoplast and symplast, supporting a physiological role for Si in addition to its structural function. These results reveal that the immobilization of metals within the observed endomembrane structures presents a structural and functional barrier and affects bioavailability. The combination of high spatial and chemical X-ray microscopy techniques highlights how in situ analysis can yield new insights into the complexity of the wheat aleurone layer, whose precise biochemical composition, morphology, and structural characteristics are still not unequivocally resolved. PMID:21447756
Cortical activation in response to pure taste stimuli during the physiological states of hunger and satiety.

PubMed

Haase, Lori; Cerf-Ducastel, Barbara; Murphy, Claire

2009-02-01

This event-related functional magnetic resonance imaging (er-fMRI) study investigated BOLD signal change in response to a series of pure gustatory stimuli that varied in stimulus quality when subjects were hungry and sated with a nutritional pre-load. Group analyses showed significant differences in activation in the hunger minus satiety condition in response to sucrose, caffeine, saccharin, and citric acid within the thalamus, hippocampus, and parahippocampus. When examining the hunger and satiety conditions, activation varied as a function of stimulus, with the majority of the stimuli exhibiting significantly greater activation in the hunger state within the insula, thalamus, and substantia nigra, in contrast to decreased activation in the satiated state within the parahippocampus, hippocampus, amygdala, and anterior cingulate. Region of interest (ROI) analysis revealed two significant interactions, ROI by physiology and ROI by physiology by stimulus. In the satiety condition, the primary (inferior and superior insulae) and secondary (OFC 11 and OFC 47) taste regions exhibited significantly greater brain activation in response to all stimuli than regions involved in processing eating behavior (hypothalamus), affect (amygdala), and memory (hippocampus, parahippocampus and entorhinal cortex). These same regions demonstrated significantly greater activation within the hunger condition than the satiety condition, with the exception of the superior insula. Furthermore, the patterns of activation differed as a function taste stimulus, with greater activation in response to sucrose than to the other stimuli. These differential patterns of activation suggest that the physiological states of hunger and satiety produce divergent activation in multiple brain areas in response to different pure gustatory stimuli.

Effects of inert dust on olive (Olea europaea L.) leaf physiological para.

PubMed

Nanos, George D; Ilias, Ilias F

2007-05-01

Cement factories are major pollutants for the surrounding areas. Inert dust deposition has been found to affect photosynthesis, stomatal functioning and productivity. Very few studies have been conducted on the effects of cement kiln dust on the physiology of perennial fruit crops. Our goal was to study some cement dust effects on olive leaf physiology.effects on olive leaf physiology. On Cement kiln dust has been applied periodically since April 2003 onto olive leaves. Cement dust accumulation and various leaf physiological parameters were evaluated early in July 2003. Measurements were also taken on olive trees close to the cement factory. Leaf dry matter content and specific leaf weight increased with leaf age and dust content. Cement dust decreased leaf total chlorophyll content and chlorophyll a/chlorophyll b ratio. As a result, photosynthetic rate and quantum yield decreased. In addition, transpiration rate slightly decreased, stomatal conductance to H2O and CO2 movement decreased, internal CO2 concentration remained constant and leaf temperature increased. The changes in chlorophyll are possibly due to shading and/or photosystem damage. The changes in stomatal functioning were possibly due to dust accumulation between the peltates or othe effects on stomata. Dust (in this case from a cement kiln) seems to cause substantial changes to leaf physiology, possibly leading to reduced olive productivity. Avoidance of air contamination from cement factories by using available technology should be examined together with any possible methodologies to reduce plant tissue contamination from cement dust. Longterm effects of dust (from cement kiln or other sources) on olive leaf, plant productivity and nutritional quality of edible parts could be studied for conclusive results on dust contamination effects to perennial crops.
Concerted Changes in Gene Expression and Cell Physiology of the Cyanobacterium Synechocystis sp. Strain PCC 6803 during Transitions between Nitrogen and Light-Limited Growth1[W][OA

PubMed Central

Aguirre von Wobeser, Eneas; Ibelings, Bas W.; Bok, Jasper; Krasikov, Vladimir; Huisman, Jef; Matthijs, Hans C.P.

2011-01-01

Physiological adaptation and genome-wide expression profiles of the cyanobacterium Synechocystis sp. strain PCC 6803 in response to gradual transitions between nitrogen-limited and light-limited growth conditions were measured in continuous cultures. Transitions induced changes in pigment composition, light absorption coefficient, photosynthetic electron transport, and specific growth rate. Physiological changes were accompanied by reproducible changes in the expression of several hundred open reading frames, genes with functions in photosynthesis and respiration, carbon and nitrogen assimilation, protein synthesis, phosphorus metabolism, and overall regulation of cell function and proliferation. Cluster analysis of the nearly 1,600 regulated open reading frames identified eight clusters, each showing a different temporal response during the transitions. Two large clusters mirrored each other. One cluster included genes involved in photosynthesis, which were up-regulated during light-limited growth but down-regulated during nitrogen-limited growth. Conversely, genes in the other cluster were down-regulated during light-limited growth but up-regulated during nitrogen-limited growth; this cluster included several genes involved in nitrogen uptake and assimilation. These results demonstrate complementary regulation of gene expression for two major metabolic activities of cyanobacteria. Comparison with batch-culture experiments revealed interesting differences in gene expression between batch and continuous culture and illustrates that continuous-culture experiments can pick up subtle changes in cell physiology and gene expression. PMID:21205618
Cryptococcus neoformans Mediator Protein Ssn8 Negatively Regulates Diverse Physiological Processes and Is Required for Virulence

PubMed Central

Wang, Lin-Ing; Lin, Yu-Sheng; Liu, Kung-Hung; Jong, Ambrose Y.; Shen, Wei-Chiang

2011-01-01

Cryptococcus neoformans is a ubiquitously distributed human pathogen. It is also a model system for studying fungal virulence, physiology and differentiation. Light is known to inhibit sexual development via the evolutionarily conserved white collar proteins in C. neoformans. To dissect molecular mechanisms regulating this process, we have identified the SSN8 gene whose mutation suppresses the light-dependent CWC1 overexpression phenotype. Characterization of sex-related phenotypes revealed that Ssn8 functions as a negative regulator in both heterothallic a-α mating and same-sex mating processes. In addition, Ssn8 is involved in the suppression of other physiological processes including invasive growth, and production of capsule and melanin. Interestingly, Ssn8 is also required for the maintenance of cell wall integrity and virulence. Our gene expression studies confirmed that deletion of SSN8 results in de-repression of genes involved in sexual development and melanization. Epistatic and yeast two hybrid studies suggest that C. neoformans Ssn8 plays critical roles downstream of the Cpk1 MAPK cascade and Ste12 and possibly resides at one of the major branches downstream of the Cwc complex in the light-mediated sexual development pathway. Taken together, our studies demonstrate that the conserved Mediator protein Ssn8 functions as a global regulator which negatively regulates diverse physiological and developmental processes and is required for virulence in C. neoformans. PMID:21559476
Physiological Factors Contributing to Postflight Changes in Functional Performance

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Feedback, D. L.; Feiverson, A. H.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts, S. H.; Reschke, M. F.; Ryder, J.; Spiering, B. A.;

2009-01-01

Astronauts experience alterations in multiple physiological systems due to exposure to the microgravity conditions of space flight. These physiological changes include sensorimotor disturbances, cardiovascular deconditioning and loss of muscle mass and strength. These changes might affect the ability of crewmembers to perform critical mission tasks immediately after landing on lunar and Martian surfaces. To date, changes in functional performance have not been systematically studied or correlated with physiological changes. To understand how changes in physiological function impact functional performance an interdisciplinary pre/postflight testing regimen (Functional Task Test, FTT) has been developed that systematically evaluates both astronaut postflight functional performance and related physiological changes. The overall objectives of the FTT are to: Develop a set of functional tasks that represent critical mission tasks for Constellation. Determine the ability to perform these tasks after flight. Identify the key physiological factors that contribute to functional decrements. Use this information to develop targeted countermeasures. The functional test battery was designed to address high priority tasks identified by the Constellation program as critical for mission success. The set of functional tests making up the FTT include the: 1) Seat Egress and Walk Test, 2) Ladder Climb Test, 3) Recovery from Fall/Stand Test, 4) Rock Translation Test, 5) Jump Down Test, 6) Torque Generation Test, and 7) Construction Activity Board Test. Corresponding physiological measures include assessments of postural and gait control, dynamic visual acuity, fine motor control, plasma volume, orthostatic intolerance, upper and lower body muscle strength, power, fatigue, control and neuromuscular drive. Crewmembers will perform both functional and physiological tests before and after short (Shuttle) and long-duration (ISS) space flight. Data will be collected on R+0 (Shuttle only), R+1, R+6 and R+30. Using a multivariate regression model we will identify which physiological systems contribute the most to impaired performance on each functional test. This will allow us to identify the physiological systems that play the largest role in decrement in functional performance. Using this information we can then design and implement countermeasures that specifically target the physiological systems most responsible for the altered functional performance associated with space flight.

Differential physiological changes following internet exposure in higher and lower problematic internet users

PubMed Central

Romano, Michela; Re, Federica; Roaro, Alessandra; Osborne, Lisa A.; Viganò, Caterina; Truzoli, Roberto

2017-01-01

Problematic internet use (PIU) has been suggested as in need of further research with a view to being included as a disorder in future Diagnostic and Statistical Manual (DSM) of the American Psychiatric Association, but lack of knowledge about the impact of internet cessation on physiological function remains a major gap in knowledge and a barrier to PIU classification. One hundred and forty-four participants were assessed for physiological (blood pressure and heart rate) and psychological (mood and state anxiety) function before and after an internet session. Individuals also completed a psychometric examination relating to their usage of the internet, as well as their levels of depression and trait anxiety. Individuals who identified themselves as having PIU displayed increases in heart rate and systolic blood pressure, as well as reduced mood and increased state of anxiety, following cessation of internet session. There were no such changes in individuals with no self-reported PIU. These changes were independent of levels of depression and trait anxiety. These changes after cessation of internet use are similar to those seen in individuals who have ceased using sedative or opiate drugs, and suggest PIU deserves further investigation and serious consideration as a disorder. PMID:28542470
Plant anesthesia supports similarities between animals and plants: Claude Bernard's forgotten studies.

PubMed

Grémiaux, Alexandre; Yokawa, Ken; Mancuso, Stefano; Baluška, František

2014-01-01

The French scientist Claude Bernard (1813-1878) is famous for his discoveries in physiology and for introducing rigorous experimental methods to medicine and biology. One of his major technical innovations was the use of chemicals in order to disrupt normal physiological function to test hypotheses. But less known is his conviction that the physiological functions of all living organisms rely on the same underlying principles. He hypothesized that similarly to animals, plants are also able to sense changes in their environment. He called this ability "sensitivity." In order to test his ideas, he performed anesthesia on plants and the results of these experiments were presented in 1878 in "Leçonssur les phénomènes de la vie communs aux animaux et aux végétaux." The phenomena described by Claude Bernard more than a century ago are not fully understood yet. Here, we present a short overview of anesthetic effects in animals and we discuss how anesthesia affects plant movements, seed germination, and photosynthesis. Surprisingly, these phenomena may have ecological relevance, since stressed plants generate anesthetics such as ethylene and ether. Finally, we discuss Claude Bernard's interpretations and conclusions in the perspective of modern plant sciences.
Dietary inorganic nitrate: From villain to hero in metabolic disease?

PubMed Central

McNally, Ben; Griffin, Julian L.

2015-01-01

Historically, inorganic nitrate was believed to be an inert by‐product of nitric oxide (NO) metabolism that was readily excreted by the body. Studies utilising doses of nitrate far in excess of dietary and physiological sources reported potentially toxic and carcinogenic effects of the anion. However, nitrate is a significant component of our diets, with the majority of the anion coming from green leafy vegetables, which have been consistently shown to offer protection against obesity, type 2 diabetes and metabolic diseases. The discovery of a metabolic pathway in mammals, in which nitrate is reduced to NO, via nitrite, has warranted a re‐examination of the physiological role of this small molecule. Obesity, type 2 diabetes and the metabolic syndrome are associated with a decrease in NO bioavailability. Recent research suggests that the nitrate‐nitrite‐NO pathway may be harnessed as a therapeutic to supplement circulating NO concentrations, with both anti‐obesity and anti‐diabetic effects, as well as improving vascular function. In this review, we examine the key studies that have led to the re‐evaluation of the physiological function of inorganic nitrate, from toxic and carcinogenic metabolite, to a potentially important and beneficial agent in the treatment of metabolic disease. PMID:26227946
Physiological effects on fishes in a high-CO2 world

NASA Astrophysics Data System (ADS)

Ishimatsu, Atsushi; Hayashi, Masahiro; Lee, Kyoung-Seon; Kikkawa, Takashi; Kita, Jun

2005-09-01

Fish are important members of both freshwater and marine ecosystems and constitute a major protein source in many countries. Thus potential reduction of fish resources by high-CO2 conditions due to the diffusion of atmospheric CO2 into the surface waters or direct CO2 injection into the deep sea can be considered as another potential threat to the future world population. Fish, and other water-breathing animals, are more susceptible to a rise in environmental CO2 than terrestrial animals because the difference in CO2 partial pressure (PCO2) of the body fluid of water-breathing animals and ambient medium is much smaller (only a few torr (1 torr = 0.1333 kPa = 1316 μatm)) than in terrestrial animals (typically 30-40 torr). A survey of the literature revealed that hypercapnia acutely affects vital physiological functions such as respiration, circulation, and metabolism, and changes in these functions are likely to reduce growth rate and population size through reproduction failure and change the distribution pattern due to avoidance of high-CO2 waters or reduced swimming activities. This paper reviews the acute and chronic effects of CO2 on fish physiology and tries to clarify necessary areas of future research.
The soil microbiome — from metagenomics to metaphenomics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansson, Janet K.; Hofmockel, Kirsten S.

Soil microorganisms carry out important processes, including support of plant growth and cycling of carbon and other nutrients. However, the majority of soil microbes have not yet been isolated and their functions are largely unknown. Although metagenomic sequencing reveals microbial identities and functional gene information, it includes DNA from microbes with vastly varying physiological states. Therefore, metagenomics is only predictive of community functional potential. We posit that the next frontier lies in understanding the metaphenome, the product of the combined genetic potential of the microbiome and available resources. Here in this paper we describe examples of opportunities towards gaining understandingmore » of the soil metaphenome.« less
The soil microbiome — from metagenomics to metaphenomics

DOE PAGES

Jansson, Janet K.; Hofmockel, Kirsten S.

2018-02-15

Soil microorganisms carry out important processes, including support of plant growth and cycling of carbon and other nutrients. However, the majority of soil microbes have not yet been isolated and their functions are largely unknown. Although metagenomic sequencing reveals microbial identities and functional gene information, it includes DNA from microbes with vastly varying physiological states. Therefore, metagenomics is only predictive of community functional potential. We posit that the next frontier lies in understanding the metaphenome, the product of the combined genetic potential of the microbiome and available resources. Here in this paper we describe examples of opportunities towards gaining understandingmore » of the soil metaphenome.« less
Alteration of Endothelins: A Common Pathogenetic Mechanism in Chronic Diabetic Complications

PubMed Central

Khan, Zia Ali; Cukiernik, Mark; Fukuda, Gen; Chen, Shali; Mukherjee, Suranjana

2002-01-01

Endothelin (ET) peptides perform several physiological, vascular, and nonvascular functions and are widely distributed in a number of tissues. They are altered in several disease processes including diabetes. Alteration of ETs have been demonstrated in organs of chronic diabetic complications in both experimental and clinical studies. The majority of the effects of ET alteration in diabetes are due to altered vascular function. Furthermore, ET antagonists have been shown to prevent structural and functional changes induced by diabetes in animal models. This review discusses the contribution of ETs in the pathogenesis and the potential role of ET antagonism in the treatment of chronic diabetic complications. PMID:12546275
Does point-of-care functional echocardiography enhance cardiovascular care in the NICU?

PubMed

Sehgal, A; McNamara, P J

2008-11-01

Although the last two decades have seen major advances in the care of sick, extremely premature newborns, the approach to cardiovascular assessment and monitoring remains suboptimal owing to an overreliance on poorly predictive clinical markers such as heart rate or capillary refill time. Point-of-care functional echocardiography (PCFecho) enables real-time evaluation of cardiac performance and systemic hemodynamics to characterize acute physiology, identify the exact nature of cardiovascular compromise and guide therapeutic decisions. In this article, we will review four clinical scenarios where bedside functional cardiac imaging enabled delineation of the real clinical problem and refinement of the therapeutic care plan with direct patient benefits.
SHP2 sails from physiology to pathology.

PubMed

Tajan, Mylène; de Rocca Serra, Audrey; Valet, Philippe; Edouard, Thomas; Yart, Armelle

2015-10-01

Over the two past decades, mutations of the PTPN11 gene, encoding the ubiquitous protein tyrosine phosphatase SHP2 (SH2 domain-containing tyrosine phosphatase 2), have been identified as the causal factor of several developmental diseases (Noonan syndrome (NS), Noonan syndrome with multiple lentigines (NS-ML), and metachondromatosis), and malignancies (juvenile myelomonocytic leukemia). SHP2 plays essential physiological functions in organism development and homeostasis maintenance by regulating fundamental intracellular signaling pathways in response to a wide range of growth factors and hormones, notably the pleiotropic Ras/Mitogen-Activated Protein Kinase (MAPK) and the Phosphoinositide-3 Kinase (PI3K)/AKT cascades. Analysis of the biochemical impacts of PTPN11 mutations first identified both loss-of-function and gain-of-function mutations, as well as more subtle defects, highlighting the major pathophysiological consequences of SHP2 dysregulation. Then, functional genetic studies provided insights into the molecular dysregulations that link SHP2 mutants to the development of specific traits of the diseases, paving the way for the design of specific therapies for affected patients. In this review, we first provide an overview of SHP2's structure and regulation, then describe its molecular roles, notably its functions in modulating the Ras/MAPK and PI3K/AKT signaling pathways, and its physiological roles in organism development and homeostasis. In the second part, we describe the different PTPN11 mutation-associated pathologies and their clinical manifestations, with particular focus on the biochemical and signaling outcomes of NS and NS-ML-associated mutations, and on the recent advances regarding the pathophysiology of these diseases. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Consequences of inhibiting amyloid precursor protein processing enzymes on synaptic function and plasticity.

PubMed

Wang, Hui; Megill, Andrea; He, Kaiwen; Kirkwood, Alfredo; Lee, Hey-Kyoung

2012-01-01

Alzheimer's disease (AD) is a neurodegenerative disease, one of whose major pathological hallmarks is the accumulation of amyloid plaques comprised of aggregated β-amyloid (Aβ) peptides. It is now recognized that soluble Aβ oligomers may lead to synaptic dysfunctions early in AD pathology preceding plaque deposition. Aβ is produced by a sequential cleavage of amyloid precursor protein (APP) by the activity of β- and γ-secretases, which have been identified as major candidate therapeutic targets of AD. This paper focuses on how Aβ alters synaptic function and the functional consequences of inhibiting the activity of the two secretases responsible for Aβ generation. Abnormalities in synaptic function resulting from the absence or inhibition of the Aβ-producing enzymes suggest that Aβ itself may have normal physiological functions which are disrupted by abnormal accumulation of Aβ during AD pathology. This interpretation suggests that AD therapeutics targeting the β- and γ-secretases should be developed to restore normal levels of Aβ or combined with measures to circumvent the associated synaptic dysfunction(s) in order to have minimal impact on normal synaptic function.
Mammalian HspB1 (Hsp27) is a molecular sensor linked to the physiology and environment of the cell.

PubMed

Arrigo, André-Patrick

2017-07-01

Constitutively expressed small heat shock protein HspB1 regulates many fundamental cellular processes and plays major roles in many human pathological diseases. In that regard, this chaperone has a huge number of apparently unrelated functions that appear linked to its ability to recognize many client polypeptides that are subsequently modified in their activity and/or half-life. A major parameter to understand how HspB1 is dedicated to interact with particular clients in defined cellular conditions relates to its complex oligomerization and phosphorylation properties. Indeed, HspB1 structural organization displays dynamic and complex rearrangements in response to changes in the cellular environment or when the cell physiology is modified. These structural modifications probably reflect the formation of structural platforms aimed at recognizing specific client polypeptides. Here, I have reviewed data from the literature and re-analyzed my own studies to describe and discuss these fascinating changes in HspB1 structural organization.
Aerobic exercise and other healthy lifestyle factors that influence vascular aging.

PubMed

Santos-Parker, Jessica R; LaRocca, Thomas J; Seals, Douglas R

2014-12-01

Cardiovascular diseases (CVDs) remain the leading cause of death in the United States and other modern societies. Advancing age is the major risk factor for CVD, primarily due to stiffening of the large elastic arteries and the development of vascular endothelial dysfunction. In contrast, regular aerobic exercise protects against the development of large elastic artery stiffness and vascular endothelial dysfunction with advancing age. Moreover, aerobic exercise interventions reduce arterial stiffness and restore vascular endothelial function in previously sedentary middle-aged/older adults. Aerobic exercise exerts its beneficial effects on arterial function by modulating structural proteins, reducing oxidative stress and inflammation, and restoring nitric oxide bioavailability. Aerobic exercise may also promote "resistance" against factors that reduce vascular function and increase CVD risk with age. Preventing excessive increases in abdominal adiposity, following healthy dietary practices, maintaining a low CVD risk factor profile, and, possibly, selective use of pharmaceuticals and nutraceuticals also play a major role in preserving vascular function with aging. Copyright © 2014 The American Physiological Society.
Helminths and intestinal barrier function

PubMed Central

McKay, Derek M.; Shute, Adam; Lopes, Fernando

2017-01-01

ABSTRACT Approximately one-sixth of the worlds' population is infected with helminths and this class of parasite takes a major toll on domestic livestock. The majority of species of parasitic helminth that infect mammals live in the gut (the only niche for tapeworms) where they contact the hosts' epithelial cells. Here, the helminth-intestinal epithelial interface is reviewed in terms of the impact on, and regulation of epithelial barrier function, both intrinsic (epithelial permeability) and extrinsic (mucin, bacterial peptides, commensal bacteria) elements of the barrier. The data available on direct effects of helminths on epithelial permeability are scant, fragmentary and pales in comparison with knowledge of mobilization of immune reactions and effector cells in response to helminth parasites and how these impact intestinal barrier function. The interaction of helminth-host and helminth-host-bacteria is an important determinant of gut form and function and precisely defining these interactions will radically alter our understanding of normal gut physiology and pathophysiological reactions, revealing new approaches to infection with parasitic helminths, bacterial pathogens and idiopathic auto-inflammatory disease. PMID:28452686
Evolution and physiology of neural oxygen sensing

PubMed Central

Costa, Kauê M.; Accorsi-Mendonça, Daniela; Moraes, Davi J. A.; Machado, Benedito H.

2014-01-01

Major evolutionary trends in animal physiology have been heavily influenced by atmospheric O2 levels. Amongst other important factors, the increase in atmospheric O2 which occurred in the Pre-Cambrian and the development of aerobic respiration beckoned the evolution of animal organ systems that were dedicated to the absorption and transportation of O2, e.g., the respiratory and cardiovascular systems of vertebrates. Global variations of O2 levels in post-Cambrian periods have also been correlated with evolutionary changes in animal physiology, especially cardiorespiratory function. Oxygen transportation systems are, in our view, ultimately controlled by the brain related mechanisms, which senses changes in O2 availability and regulates autonomic and respiratory responses that ensure the survival of the organism in the face of hypoxic challenges. In vertebrates, the major sensorial system for oxygen sensing and responding to hypoxia is the peripheral chemoreflex neuronal pathways, which includes the oxygen chemosensitive glomus cells and several brainstem regions involved in the autonomic regulation of the cardiovascular system and respiratory control. In this review we discuss the concept that regulating O2 homeostasis was one of the primordial roles of the nervous system. We also review the physiology of the peripheral chemoreflex, focusing on the integrative repercussions of chemoreflex activation and the evolutionary importance of this system, which is essential for the survival of complex organisms such as vertebrates. The contribution of hypoxia and peripheral chemoreflex for the development of diseases associated to the cardiovascular and respiratory systems is also discussed in an evolutionary context. PMID:25161625
Effects of Diets High in Unsaturated Fatty Acids on Socially Induced Stress Responses in Guinea Pigs

PubMed Central

Nemeth, Matthias; Millesi, Eva; Wagner, Karl-Heinz; Wallner, Bernard

2014-01-01

Unsaturated fatty acids (UFAs), such as omega-3 and omega-6 poly- and omega-9 monounsaturated fatty acids are important nutrients and major components of neuronal cell membranes. They play a major role in modulating brain functions and physiology and may therefore diminish behavioral and physiological stress reactions in corroboration with decreased cortisol concentrations. Functionally, cortisol itself can modulate several behaviors and also the fatty acid metabolism in the long term. But only little is known about the behavioral and physiological influences of dietary UFAs in a social group, where individuals are regularly exposed to stressful situations. Therefore, the aim of this study was to determine the effects of dietary UFAs on saliva cortisol concentrations and behavioral responses in socially confronted guinea pigs. Three groups of animals were additionally supplemented with 500 mg chia seeds (high in omega-3), walnuts (high in omega-6), or peanuts (high in omega-9) per kg bodyweight each day and compared to a control group. During social confrontation saliva cortisol concentrations significantly increased in all groups, which was accompanied by a loss in bodyweight. However, cortisol levels remained lower in the chia and walnut groups compared to controls. Additionally, the walnut group displayed significantly increased locomotion, while no differences between groups were detected in socio-positive, sexual, or aggressive behaviors. Total plasma omega-3, omega-6, and omega-9 fatty acids were significantly increased in the corresponding groups, due to the dietary supplementations. However, a significant decrease in plasma omega-3 and an increase in plasma n-6 fatty acids were detected in the chia group when comparing the measurements before and after social confrontation. We conclude that both omega-3 and omega-6 polyunsaturated fatty acids can diminish behavioral and physiological stress responses to the social environment, enabling individuals to cope with social stressors, but at the expense of plasma derived omega-3 fatty acids. PMID:25551380
Salubrious effects of oxytocin on social stress-induced deficits

PubMed Central

Smith, Adam S.; Wang, Zuoxin

2012-01-01

Social relationships are a fundamental aspect of life, affecting social, psychological, physiological, and behavioral functions. While social interactions can attenuate stress and promote health, disruption, confrontations, isolation, or neglect in the social environment can each be major stressors. Social stress can impair the basal function and stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis, impairing function of multiple biological systems and posing a risk to mental and physical health. In contrast, social support can ameliorate stress-induced physiological and immunological deficits, reducing the risk of subsequent psychological distress and improving an individual's overall well-being. For better clinical treatment of these physiological and mental pathologies, it is necessary to understand the regulatory mechanisms of stress-induced pathologies as well as determine the underlying biological mechanisms that regulate social buffering of the stress system. A number of ethologically relevant animal models of social stress and species that form strong adult social bonds have been utilized to study the etiology, treatment, and prevention of stress-related disorders. While undoubtedly a number of biological pathways contribute to the social buffering of the stress response, the convergence of evidence denotes the regulatory effects of oxytocin in facilitating social bond-promoting behaviors and their effect on the stress response. Thus, oxytocin may be perceived as a common regulatory element of the social environment, stress response, and stress-induced risks on mental and physical health. PMID:22178036

An "enigmatic" L-carnosine (β-alanyl-L-histidine)? Cell proliferative activity as a fundamental property of a natural dipeptide inherent to traditional antioxidant, anti-aging biological activities: balancing and a hormonally correct agent, novel patented oral therapy dosage formulation for mobility, skeletal muscle power and functional performance, hypothalamic-pituitary- brain relationship in health, aging and stress studies.

PubMed

Babizhayev, Mark A; Yegorov, Yegor E

2015-01-01

Hypothalamic releasing and inhibiting hormones are major neuroendocrine regulators of human body metabolism being driven directly to the anterior pituitary gland via hypothalamic-hypophyseal portal veins. The alternative physiological or therapeutic interventions utilizing the pharmaco-nutritional boost of imidazole-containing dipeptides (non-hydrolized oral form of carnosine, carcinine, N-acetylcarnosine lubricant eye drops) can maintain health, enhance physical exercise performance and prevent ageing. Carnosine (β-alanyl-L-histidine) is synthesized in mammalian skeletal muscle. There is an evidence that the release of carnosine from the skeletal muscle sarcomeres moieties during physical exercise affects autonomic neurotransmission and physiological functions. Carnosine released from skeletal muscle during exercise acts as a powerful afferent physiological signaling stimulus for hypothalamus, may be transported into the hypothalamic tuberomammillary nucleus (TMN), specifically to TMN-histamine neurons and hydrolyzed herewith via activities of carnosine-degrading enzyme (carnosinase 2) localized in situ. Through the colocalized enzymatic activity of Histidine decarboxylase in the histaminergic neurons, the resulting L-histidine may subsequently be converted into histamine, which could be responsible for the effects of carnosine on neurotransmission and physiological function. Carnosine and its imidazole-containing dipeptide derivatives are renowned for their anti-aging, antioxidant, membrane protective, metal ion chelating, buffering, anti-glycation/ transglycating activities used to prevent and treat a spectrum of age-related and metabolic diseases, such as neurodegenerative disease, sight threatening eye diseases, Diabetes mellitus and its complications, cancers and other disorders due to their wide spectrum biological activities. The precursor of carnosine (and related imidazole containing compounds) synthesis in skeletal muscles beta-alanine is used as the oral supplement by athletes to achieve the fine sporting art results due to the buffering activities of carnosine and its related imidazole- containing compounds which contribute to the maintenance of the acid-base balance in the acting muscles. This work originally emphasizes that overall data indicate the signaling activities of carnosine in skeletal and cardiac muscles switching on the mechanisms of exercise-induced telomere protection and point to the stress response and growth/cellular proliferation pathways as high-priority candidates for the ongoing studies and therapeutic concepts. The therapeutic interventions utilizing the specific oral formulation (Can-C Plus), timing dosing and pharmaco-nutritional boost of imidazolecontaining dipeptides can maintain health, enhance physical exercise performance and prevent aging. The patented therapeutic concept protects the existence of the interesting physiological major activities, better controls and therapeutic treatments for aging/age-related disorders (including age-related loss of muscle mass and muscle function) using carnosine dipeptide for cellular rejuvenation and manipulating telomeres and enzyme telomerase activity that may reduce some of the physiological declines that accompany aging.
Comparative analysis of the mechanical signals in lung development and compensatory growth.

PubMed

Hsia, Connie C W

2017-03-01

This review compares the manner in which physical stress imposed on the parenchyma, vasculature and thorax and the thoraco-pulmonary interactions, drive both developmental and compensatory lung growth. Re-initiation of anatomical lung growth in the mature lung is possible when the loss of functioning lung units renders the existing physiologic-structural reserves insufficient for maintaining adequate function and physical stress on the remaining units exceeds a critical threshold. The appropriate spatial and temporal mechanical interrelationships and the availability of intra-thoracic space, are crucial to growth initiation, follow-on remodeling and physiological outcome. While the endogenous potential for compensatory lung growth is retained and may be pharmacologically augmented, supra-optimal mechanical stimulation, unbalanced structural growth, or inadequate remodeling may limit functional gain. Finding ways to optimize the signal-response relationships and resolve structure-function discrepancies are major challenges that must be overcome before the innate compensatory ability could be fully realized. Partial pneumonectomy reproducibly removes a known fraction of functioning lung units and remains the most robust model for examining the adaptive mechanisms, structure-function consequences and plasticity of the remaining functioning lung units capable of regeneration. Fundamental mechanical stimulus-response relationships established in the pneumonectomy model directly inform the exploration of effective approaches to maximize compensatory growth and function in chronic destructive lung diseases, transplantation and bioengineered lungs.
Comparative Analysis of the Mechanical Signals in Lung Development and Compensatory Growth

PubMed Central

Hsia, Connie C.W.

2017-01-01

This review compares the manner in which physical stress imposed on the parenchyma, vasculature and thorax, and the thoraco-pulmonary interactions, drive both developmental and compensatory lung growth. Re-initiation of anatomical lung growth in the mature lung is possible when the loss of functioning lung units renders the existing physiologic-structural reserves insufficient for maintaining adequate function and physical stress on the remaining units exceeds a critical threshold. The appropriate spatial and temporal mechanical interrelationships, and the availability of intra-thoracic space, are crucial to growth initiation, follow-on remodeling and physiological outcome. While the endogenous potential for compensatory lung growth is retained and may be pharmacologically augmented, supra-optimal mechanical stimulation, unbalanced structural growth, or inadequate remodeling, may limit functional gain. Finding ways to optimize the signal-response relationships and resolve structure-function discrepancies are major challenges that must be overcome before the innate compensatory ability could be fully realized. Partial pneumonectomy reproducibly removes a known fraction of functioning lung units and remains the most robust model for examining the adaptive mechanisms, structure-function consequences, and plasticity of the remaining functioning lung units capable of regeneration. Fundamental mechanical stimulus-response relationships established in the pneumonectomy model directly inform the exploration of effective approaches to maximize compensatory growth and function in chronic destructive lung diseases, transplantation and bioengineered lungs. PMID:28084523
Microglia in CNS development: Shaping the brain for the future.

PubMed

Mosser, Coralie-Anne; Baptista, Sofia; Arnoux, Isabelle; Audinat, Etienne

Microglial cells are the resident macrophages of the central nervous system (CNS) and are mainly known for their roles in neuropathologies. However, major recent developments have revealed that these immune cells actively interact with neurons in physiological conditions and can modulate the fate and functions of synapses. Originating from myeloid precursors born in the yolk sac, microglial cells invade the CNS during early embryonic development. As a consequence they can potentially influence neuronal proliferation, migration and differentiation as well as the formation and maturation of neuronal networks, thereby contributing to the entire shaping of the CNS. We review here recent evidence indicating that microglial cells are indeed involved in crucial steps of the CNS development, including neuronal survival and apoptosis, axonal growth, migration of neurons, pruning of supernumerary synapses and functional maturation of developing synapses. We also discuss current hypotheses proposing that diverting microglial cells of their physiological functions, by promoting the expression of an immune phenotype during development, may be central to neurodevelopmental disorders such as autism, schizophrenia and epilepsy. Copyright © 2017 Elsevier Ltd. All rights reserved.
Reduced cardiac vagal activity in obese children and adolescents.

PubMed

Dangardt, Frida; Volkmann, Reinhard; Chen, Yun; Osika, Walter; Mårild, Staffan; Friberg, Peter

2011-03-01

Obese children present with various cardiovascular risk factors affecting their future health. In adults, cardiac autonomic function is a major risk factor, predicting cardiovascular morbidity and mortality. We hypothesized that obese children and adolescents had a lower cardiac vagal activity than lean subjects. We measured cardiac spontaneous baroreflex sensitivity (BRS), reflecting the dynamic regulation of cardiac vagal function, in large groups of obese and lean young individuals. Cardiac BRS, using the sequence approach, was assessed in 120 obese (59 girls), 43 overweight (23 girls) and 148 lean subjects (78 girls). Obese subjects showed a decreased BRS compared to both overweight and lean subjects [16±7 versus 21±9 (P<0·01) and 22±10 ms per mmHg (P<0·0001), respectively]. The differences remained after correcting for age, gender and pubertal status. Children with obesity had low vagal activity at rest, and there was no gender difference. © 2010 The Authors. Clinical Physiology and Functional Imaging © 2010 Scandinavian Society of Clinical Physiology and Nuclear Medicine.
Cardiovascular and Hemostatic Disorders: Role of STIM and Orai Proteins in Vascular Disorders.

PubMed

Tanwar, Jyoti; Trebak, Mohamed; Motiani, Rajender K

2017-01-01

Store-operated Ca 2+ entry (SOCE) mediated by STIM and Orai proteins is a highly regulated and ubiquitous signaling pathway that plays an important role in various cellular and physiological functions. Endoplasmic reticulum (ER) serves as the major site for intracellular Ca 2+ storage. Stromal Interaction Molecule 1/2 (STIM1/2) sense decrease in ER Ca 2+ levels and transmits the message to plasma membrane Ca 2+ channels constituted by Orai family members (Orai1/2/3) resulting in Ca 2+ influx into the cells. This increase in cytosolic Ca 2+ in turn activates a variety of signaling cascades to regulate a plethora of cellular functions. Evidence from the literature suggests that SOCE dysregulation is associated with several pathophysiologies, including vascular disorders. Interestingly, recent studies have suggested that STIM proteins may also regulate vascular functions independent of their contribution to SOCE. In this updated book chapter, we will focus on the physiological role of STIM and Orai proteins in the vasculature (endothelial cells and vascular smooth muscle cells). We will further retrospect the literature implicating a critical role for these proteins in vascular disease.
L-type Ca2+ channels in mood, cognition and addiction: integrating human and rodent studies with a focus on behavioural endophenotypes.

PubMed

Kabir, Z D; Lee, A S; Rajadhyaksha, A M

2016-10-15

Brain Ca v 1.2 and Ca v 1.3 L-type Ca 2+ channels play key physiological roles in various neuronal processes that contribute to brain function. Genetic studies have recently identified CACNA1C as a candidate risk gene for bipolar disorder (BD), schizophrenia (SCZ), major depressive disorder (MDD) and autism spectrum disorder (ASD), and CACNA1D for BD and ASD, suggesting a contribution of Ca v 1.2 and Ca v 1.3 Ca 2+ signalling to the pathophysiology of neuropsychiatric disorders. Once considered sole clinical entities, it is now clear that BD, SCZ, MDD and ASD share common phenotypic features, most likely due to overlapping neurocircuitry and common molecular mechanisms. A major future challenge lies in translating the human genetic findings to pathological mechanisms that are translatable back to the patient. One approach for tackling such a daunting scientific endeavour for complex behaviour-based neuropsychiatric disorders is to examine intermediate biological phenotypes in the context of endophenotypes within distinct behavioural domains. This will better allow us to integrate findings from genes to behaviour across species, and improve the chances of translating preclinical findings to clinical practice. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.
Back-Propagation of Physiological Action Potential Output in Dendrites of Slender-Tufted L5A Pyramidal Neurons

PubMed Central

Grewe, Benjamin F.; Bonnan, Audrey; Frick, Andreas

2009-01-01

Pyramidal neurons of layer 5A are a major neocortical output type and clearly distinguished from layer 5B pyramidal neurons with respect to morphology, in vivo firing patterns, and connectivity; yet knowledge of their dendritic properties is scant. We used a combination of whole-cell recordings and Ca2+ imaging techniques in vitro to explore the specific dendritic signaling role of physiological action potential patterns recorded in vivo in layer 5A pyramidal neurons of the whisker-related ‘barrel cortex’. Our data provide evidence that the temporal structure of physiological action potential patterns is crucial for an effective invasion of the main apical dendrites up to the major branch point. Both the critical frequency enabling action potential trains to invade efficiently and the dendritic calcium profile changed during postnatal development. In contrast to the main apical dendrite, the more passive properties of the short basal and apical tuft dendrites prevented an efficient back-propagation. Various Ca2+ channel types contributed to the enhanced calcium signals during high-frequency firing activity, whereas A-type K+ and BKCa channels strongly suppressed it. Our data support models in which the interaction of synaptic input with action potential output is a function of the timing, rate and pattern of action potentials, and dendritic location. PMID:20508744
The quest to make fully functional human pancreatic beta cells from embryonic stem cells: climbing a mountain in the clouds.

PubMed

Johnson, James D

2016-10-01

The production of fully functional insulin-secreting cells to treat diabetes is a major goal of regenerative medicine. In this article, I review progress towards this goal over the last 15 years from the perspective of a beta cell biologist. I describe the current state-of-the-art, and speculate on the general approaches that will be required to identify and achieve our ultimate goal of producing functional beta cells. The need for deeper phenotyping of heterogeneous cultures of stem cell derived islet-like cells in parallel with a better understanding of the heterogeneity of the target cell type(s) is emphasised. This deep phenotyping should include high-throughput single-cell analysis, as well as comprehensive 'omics technologies to provide unbiased characterisation of cell products and human beta cells. There are justified calls for more detailed and well-powered studies of primary human pancreatic beta cell physiology, and I propose online databases of standardised human beta cell responses to physiological stimuli, including both functional and metabolomic/proteomic/transcriptomic profiles. With a concerted, community-wide effort, including both basic and applied scientists, beta cell replacement will become a clinical reality for patients with diabetes.
Fetal programming as a predictor of adult health or disease: the need to reevaluate fetal heart function.

PubMed

Miranda, Joana O; Ramalho, Carla; Henriques-Coelho, Tiago; Areias, José Carlos

2017-11-01

Epidemiologic and experimental evidence suggests that adverse stimuli during critical periods in utero permanently alters organ structure and function and may have persistent consequences for the long-term health of the offspring. Fetal hypoxia, maternal malnutrition, or ventricular overloading are among the major adverse conditions that can compromise cardiovascular development in early life. With the heart as a central organ in fetal adaptive mechanisms, a deeper understanding of the fetal cardiovascular physiology and of the echocardiographic tools to assess both normal and stressed pregnancies would give precious information on fetal well-being and hopefully may help in early identification of special risk groups for cardiovascular diseases later in life. Assessment of cardiac function in the fetus represents an additional challenge when comparing to children and adults, requiring advanced training and a critical approach to properly acquire and interpret functional parameters. This review summarizes the basic fetal cardiovascular physiology and the main differences from the mature postnatal circulation, provides an overview of the particularities of echocardiographic evaluation in the fetus, and finally proposes an integrated view of in utero programming of cardiovascular diseases later in life, highlighting priorities for future clinical research.
Preparation of Single-cohort Colonies and Hormone Treatment of Worker Honeybees to Analyze Physiology Associated with Role and/or Endocrine System.

PubMed

Ueno, Takayuki; Kawasaki, Kiyoshi; Kubo, Takeo

2016-09-06

Honeybee workers are engaged in various tasks related to maintaining colony activity. The tasks of the workers change according to their age (age-related division of labor). Young workers are engaged in nursing the brood (nurse bees), while older workers are engaged in foraging for nectar and pollen (foragers). The physiology of the workers changes in association with this role shift. For example, the main function of the hypopharyngeal glands (HPGs) changes from the secretion of major royal jelly proteins (MRJPs) to the secretion of carbohydrate-metabolizing enzymes. Because worker tasks change as the workers age in typical colonies, it is difficult to discriminate the physiological changes that occur with aging from those that occur with the role shift. To study the physiological changes in worker tissues, including the HPGs, in association with the role shift, it would be useful to manipulate the honeybee colony population by preparing single-cohort colonies in which workers of almost the same age perform different tasks. Here we describe a detailed protocol for preparing single-cohort colonies for this analysis. Six to eight days after single-cohort colony preparation, precocious foragers that perform foraging tasks earlier than usual appear in the colony. Representative results indicated role-associated changes in HPG gene expression, suggesting role-associated HPG function. In addition to manipulating the colony population, analysis of the endocrine system is important for investigating role-associated physiology. Here, we also describe a detailed protocol for treating workers with 20-hydroxyecdysone (20E), an active form of ecdysone, and methoprene, a juvenile hormone analogue. The survival rate of treated bees was sufficient to examine gene expression in the HPGs. Gene expression changes were observed in response to 20E- and/or methoprene-treatment, suggesting that hormone treatments induce physiological changes of the HPGs. The protocol for hormone treatment described here is appropriate for examining hormonal effects on worker physiology.
Intra-colonial diversity in the scleractinian coral, Acropora millepora: identifying the nutritional gradients underlying physiological integration and compartmentalised functioning

PubMed Central

Humphrey, Craig A.; Severati, Andrea; Francis, David S.

2018-01-01

Scleractinian corals are colonial organisms comprising multiple physiologically integrated polyps and branches. Colonialism in corals is highly beneficial, and allows a single colony to undergo several life processes at once through physiological integration and compartmentalised functioning. Elucidating differences in the biochemical composition of intra-colonial branch positions will provide valuable insight into the nutritional reserves underlying different regions in individual coral colonies. This will also ascertain prudent harvesting strategies of wild donor-colonies to generate coral stock with high survival and vigour prospects for reef-rehabilitation efforts and captive husbandry. This study examined the effects of colony branch position on the nutritional profile of two different colony sizes of the common scleractinian, Acropora millepora. For smaller colonies, branches were sampled at three locations: the colony centre (S-centre), 50% of the longitudinal radius length (LRL) (S-50), and the colony edge (S-edge). For larger colonies, four locations were sampled: the colony centre (L-centre), 33.3% of the LRL (L-33), 66.6% of the LRL (L-66), and the edge (L-edge). Results demonstrate significant branch position effects, with the edge regions containing higher protein, likely due to increased tissue synthesis and calcification. Meanwhile, storage lipid and total fatty acid concentrations were lower at the edges, possibly reflecting catabolism of high-energy nutrients to support proliferating cells. Results also showed a significant effect of colony size in the two classes examined. While the major protein and structural lipid sink was exhibited at the edge for both sizes, the major sink for high-energy lipids and fatty acids appeared to be the L-66 position of the larger colonies and the S-centre and S-50 positions for the smaller colonies. These results confirm that the scleractinian coral colony is not nutritionally homogeneous, and while different regions of the coral colony are functionally specialised, so too are their nutritional profiles geared toward meeting specific energetic demands. PMID:29404204
Employee subjective well-being and physiological functioning: An integrative model.

PubMed

Kuykendall, Lauren; Tay, Louis

2015-01-01

Research shows that worker subjective well-being influences physiological functioning-an early signal of poor health outcomes. While several theoretical perspectives provide insights on this relationship, the literature lacks an integrative framework explaining the relationship. We develop a conceptual model explaining the link between subjective well-being and physiological functioning in the context of work. Integrating positive psychology and occupational stress perspectives, our model explains the relationship between subjective well-being and physiological functioning as a result of the direct influence of subjective well-being on physiological functioning and of their common relationships with work stress and personal resources, both of which are influenced by job conditions.
Basolateral membrane K+ channels in renal epithelial cells

PubMed Central

Devor, Daniel C.

2012-01-01

The major function of epithelial tissues is to maintain proper ion, solute, and water homeostasis. The tubule of the renal nephron has an amazingly simple structure, lined by epithelial cells, yet the segments (i.e., proximal tubule vs. collecting duct) of the nephron have unique transport functions. The functional differences are because epithelial cells are polarized and thus possess different patterns (distributions) of membrane transport proteins in the apical and basolateral membranes of the cell. K+ channels play critical roles in normal physiology. Over 90 different genes for K+ channels have been identified in the human genome. Epithelial K+ channels can be located within either or both the apical and basolateral membranes of the cell. One of the primary functions of basolateral K+ channels is to recycle K+ across the basolateral membrane for proper function of the Na+-K+-ATPase, among other functions. Mutations of these channels can cause significant disease. The focus of this review is to provide an overview of the basolateral K+ channels of the nephron, providing potential physiological functions and pathophysiology of these channels, where appropriate. We have taken a “K+ channel gene family” approach in presenting the representative basolateral K+ channels of the nephron. The basolateral K+ channels of the renal epithelia are represented by members of the KCNK, KCNJ, KCNQ, KCNE, and SLO gene families. PMID:22338089
Exercise physiology in chronic mechanical circulatory support patients: vascular function and beyond.

PubMed

Hayward, Christopher S; Fresiello, Libera; Meyns, Bart

2016-05-01

The majority of patients currently implanted with left ventricular assist devices have the expectation of support for more than 2 years. As a result, survival alone is no longer a sufficient distinctive for this technology, and there have been many studies within the last few years examining functional capacity and exercise outcomes. Despite strong evidence for functional class improvements and increases in simple measures of walking distance, there remains incomplete normalization of exercise capacity, even in the presence of markedly improved resting hemodynamics. Reasons for this remain unclear. Despite current pumps being run at a fixed speed, it is widely recognized that pump outputs significantly increase with exercise. The mechanism of this increase involves the interaction between preload, afterload, and the intrinsic pump function curves. The role of the residual heart function is also important in determining total cardiac output, as well as whether the aortic valve opens with exercise. Interactions with the vasculature, with skeletal muscle blood flow and the state of the autonomic nervous system are also likely to be important contributors to exercise performance. Further studies examining optimization of pump function with active pump speed modulation and options for optimization of the overall patient condition are likely to be needed to allow left ventricular assist devices to be used with the hope of full functional physiological recovery.
Derivation of Functional Human Astrocytes from Cerebral Organoids

PubMed Central

Dezonne, Rômulo Sperduto; Sartore, Rafaela Costa; Nascimento, Juliana Minardi; Saia-Cereda, Verônica M.; Romão, Luciana Ferreira; Alves-Leon, Soniza Vieira; de Souza, Jorge Marcondes; Martins-de-Souza, Daniel; Rehen, Stevens Kastrup; Gomes, Flávia Carvalho Alcantara

2017-01-01

Astrocytes play a critical role in the development and homeostasis of the central nervous system (CNS). Astrocyte dysfunction results in several neurological and degenerative diseases. However, a major challenge to our understanding of astrocyte physiology and pathology is the restriction of studies to animal models, human post-mortem brain tissues, or samples obtained from invasive surgical procedures. Here, we report a protocol to generate human functional astrocytes from cerebral organoids derived from human pluripotent stem cells. The cellular isolation of cerebral organoids yielded cells that were morphologically and functionally like astrocytes. Immunolabelling and proteomic assays revealed that human organoid-derived astrocytes express the main astrocytic molecular markers, including glutamate transporters, specific enzymes and cytoskeletal proteins. We found that organoid-derived astrocytes strongly supported neuronal survival and neurite outgrowth and responded to ATP through transient calcium wave elevations, which are hallmarks of astrocyte physiology. Additionally, these astrocytes presented similar functional pathways to those isolated from adult human cortex by surgical procedures. This is the first study to provide proteomic and functional analyses of astrocytes isolated from human cerebral organoids. The isolation of these astrocytes holds great potential for the investigation of developmental and evolutionary features of the human brain and provides a useful approach to drug screening and neurodegenerative disease modelling. PMID:28345587
Representation of the Physiological Factors Contributing to Postflight Changes in Functional Performance Using Motion Analysis Software

NASA Technical Reports Server (NTRS)

Parks, Kelsey

2010-01-01

Astronauts experience changes in multiple physiological systems due to exposure to the microgravity conditions of space flight. To understand how changes in physiological function influence functional performance, a testing procedure has been developed that evaluates both astronaut postflight functional performance and related physiological changes. Astronauts complete seven functional and physiological tests. The objective of this project is to use motion tracking and digitizing software to visually display the postflight decrement in the functional performance of the astronauts. The motion analysis software will be used to digitize astronaut data videos into stick figure videos to represent the astronauts as they perform the Functional Tasks Tests. This project will benefit NASA by allowing NASA scientists to present data of their neurological studies without revealing the identities of the astronauts.
Transcriptional Profiling of Hypoxic Neural Stem Cells Identifies Calcineurin-NFATc4 Signaling as a Major Regulator of Neural Stem Cell Biology

PubMed Central

Moreno, Marta; Fernández, Virginia; Monllau, Josep M.; Borrell, Víctor; Lerin, Carles; de la Iglesia, Núria

2015-01-01

Summary Neural stem cells (NSCs) reside in a hypoxic microenvironment within the brain. However, the crucial transcription factors (TFs) that regulate NSC biology under physiologic hypoxia are poorly understood. Here we have performed gene set enrichment analysis (GSEA) of microarray datasets from hypoxic versus normoxic NSCs with the aim of identifying pathways and TFs that are activated under oxygen concentrations mimicking normal brain tissue microenvironment. Integration of TF target (TFT) and pathway enrichment analysis identified the calcium-regulated TF NFATc4 as a major candidate to regulate hypoxic NSC functions. Nfatc4 expression was coordinately upregulated by top hypoxia-activated TFs, while NFATc4 target genes were enriched in hypoxic NSCs. Loss-of-function analyses further revealed that the calcineurin-NFATc4 signaling axis acts as a major regulator of NSC self-renewal and proliferation in vitro and in vivo by promoting the expression of TFs, including Id2, that contribute to the maintenance of the NSC state. PMID:26235896
Physiological geroscience: targeting function to increase healthspan and achieve optimal longevity

PubMed Central

Justice, Jamie N.; LaRocca, Thomas J.

2015-01-01

Abstract Most nations of the world are undergoing rapid and dramatic population ageing, which presents great socio‐economic challenges, as well as opportunities, for individuals, families, governments and societies. The prevailing biomedical strategy for reducing the healthcare impact of population ageing has been ‘compression of morbidity’ and, more recently, to increase healthspan, both of which seek to extend the healthy period of life and delay the development of chronic diseases and disability until a brief period at the end of life. Indeed, a recently established field within biological ageing research, ‘geroscience’, is focused on healthspan extension. Superimposed on this background are new attitudes and demand for ‘optimal longevity’ – living long, but with good health and quality of life. A key obstacle to achieving optimal longevity is the progressive decline in physiological function that occurs with ageing, which causes functional limitations (e.g. reduced mobility) and increases the risk of chronic diseases, disability and mortality. Current efforts to increase healthspan centre on slowing the fundamental biological processes of ageing such as inflammation/oxidative stress, increased senescence, mitochondrial dysfunction, impaired proteostasis and reduced stress resistance. We propose that optimization of physiological function throughout the lifespan should be a major emphasis of any contemporary biomedical policy addressing global ageing. Effective strategies should delay, reduce in magnitude or abolish reductions in function with ageing (primary prevention) and/or improve function or slow further declines in older adults with already impaired function (secondary prevention). Healthy lifestyle practices featuring regular physical activity and ideal energy intake/diet composition represent first‐line function‐preserving strategies, with pharmacological agents, including existing and new pharmaceuticals and novel ‘nutraceutical’ compounds, serving as potential complementary approaches. Future research efforts should focus on defining the temporal patterns of functional declines with ageing, identifying the underlying mechanisms and modulatory factors involved, and establishing the most effective lifestyle practices and pharmacological options for maintaining function. Continuing development of effective behavioural approaches for enhancing adherence to healthy ageing practices in diverse populations, and ongoing analysis of the socio‐economic costs and benefits of healthspan extension will be important supporting goals. To meet the demands created by rapid population ageing, a new emphasis in physiological geroscience is needed, which will require the collaborative, interdisciplinary efforts of investigators working throughout the translational research continuum from basic science to public health. PMID:25639909
Thick Filament Protein Network, Functions, and Disease Association.

PubMed

Wang, Li; Geist, Janelle; Grogan, Alyssa; Hu, Li-Yen R; Kontrogianni-Konstantopoulos, Aikaterini

2018-03-13

Sarcomeres consist of highly ordered arrays of thick myosin and thin actin filaments along with accessory proteins. Thick filaments occupy the center of sarcomeres where they partially overlap with thin filaments. The sliding of thick filaments past thin filaments is a highly regulated process that occurs in an ATP-dependent manner driving muscle contraction. In addition to myosin that makes up the backbone of the thick filament, four other proteins which are intimately bound to the thick filament, myosin binding protein-C, titin, myomesin, and obscurin play important structural and regulatory roles. Consistent with this, mutations in the respective genes have been associated with idiopathic and congenital forms of skeletal and cardiac myopathies. In this review, we aim to summarize our current knowledge on the molecular structure, subcellular localization, interacting partners, function, modulation via posttranslational modifications, and disease involvement of these five major proteins that comprise the thick filament of striated muscle cells. © 2018 American Physiological Society. Compr Physiol 8:631-709, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

The vaginal microbiota, host defence and reproductive physiology.

PubMed

Smith, Steven B; Ravel, Jacques

2017-01-15

The interaction between the human host and the vaginal microbiota is highly dynamic. Major changes in the vaginal physiology and microbiota over a woman's lifetime are largely shaped by transitional periods such as puberty, menopause and pregnancy, while daily fluctuations in microbial composition observed through culture-independent studies are more likely to be the results of daily life activities and behaviours. The vaginal microbiota of reproductive-aged women is largely made up of at least five different community state types. Four of these community state types are dominated by lactic-acid producing Lactobacillus spp. while the fifth is commonly composed of anaerobes and strict anaerobes and is sometimes associated with vaginal symptoms. The production of lactic acid has been associated with contributing to the overall health of the vagina due to its direct and indirect effects on pathogens and host defence. Some species associated with non-Lactobacillus vaginal microbiota may trigger immune responses as well as degrade the host mucosa, processes that ultimately increase susceptibility to infections and contribute to negative reproductive outcomes such as infertility and preterm birth. Further studies are needed to better understand the functional underpinnings of how the vaginal microbiota affect host physiology but also how host physiology affects the vaginal microbiota. Understanding this fine-tuned interaction is key to maintaining women's reproductive health. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.
Laminar shear stress regulates endothelial kinin B1 receptor expression and function: potential implication in atherogenesis

PubMed Central

Duchene, Johan; Cayla, Cécile; Vessillier, Sandrine; Scotland, Ramona; Yamashiro, Kazuo; Lecomte, Florence; Syed, Irfan; Vo, Phuong; Marrelli, Alessandra; Pitzalis, Costantino; Cipollone, Francesco; Schanstra, Joost; Bascands, Jean-Loup; Hobbs, Adrian J; Perretti, Mauro; Ahluwalia, Amrita

2009-01-01

OBJECTIVE The pro-inflammatory phenotype induced by low laminar shear stress (LSS) is implicated in atherogenesis. The kinin B1 receptor (B1R), known to be induced by inflammatory stimuli, exerts many pro-inflammatory effects including vasodilatation and leukocyte recruitment. We investigated whether low LSS is a stimulus for endothelial B1R expression and function. METHODS AND RESULTS Human and mouse atherosclerotic plaques expressed high level of B1R mRNA and protein. In addition, B1R expression was upregulated in the aortic arch (low LSS region) of ApoE-/- mice fed a high fat diet compared to vascular regions of high LSS and animals fed normal chow. Of interest, a greater expression of B1R was noticed in endothelial cells from regions of low LSS in aortic arch of ApoE-/- mice. B1R was also upregulated in human umbilical vein endothelial cells (HUVEC) exposed to low LSS (0-2dyn/cm2) compared to physiological LSS (6-10dyn/cm2): an effect similarly evident in murine vascular tissue perfused ex vivo. Functionally, B1R activation increased prostaglandin and CXCL5 expression in cells exposed to low, but not physiological, LSS. IL-1β and ox-LDL induced B1R expression and function in HUVECs, a response substantially enhanced under low LSS conditions and inhibited by blockade of NFκB activation. CONCLUSION Herein, we show that LSS is a major determinant of functional B1R expression in endothelium. Furthermore, whilst physiological high LSS is a powerful repressor of this inflammatory receptor, low LSS at sites of atheroma are associated with substantial upregulation, identifying this receptor as a potential therapeutic target. CONDENSED ABSTRACT Low laminar shear stress (LSS) underlies the pro-inflammatory processes in atherogenesis. Herein, we demonstrate that whilst physiological LSS represses inflammatory kinin B1 receptor (B1R) expression/function, low atherogenic LSS is associated with profound upregulation of both in atherosclerosis in both humans and animal models, highlighting B1R as an exciting potential therapeutic target. PMID:19661485
Proteoglycomics: Recent Progress and Future Challenges

PubMed Central

Ly, Mellisa; Laremore, Tatiana N.

2010-01-01

Abstract Proteoglycomics is a systematic study of structure, expression, and function of proteoglycans, a posttranslationally modified subset of a proteome. Although relying on the established technologies of proteomics and glycomics, proteoglycomics research requires unique approaches for elucidating structure–function relationships of both proteoglycan components, glycosaminoglycan chain, and core protein. This review discusses our current understanding of structure and function of proteoglycans, major players in the development, normal physiology, and disease. A brief outline of the proteoglycomic sample preparation and analysis is provided along with examples of several recent proteoglycomic studies. Unique challenges in the characterization of glycosaminoglycan component of proteoglycans are discussed, with emphasis on the many analytical tools used and the types of information they provide. PMID:20450439
How hormones influence composition and physiological function of the brain-blood barrier.

PubMed

Hampl, R; Bičíková, M; Sosvorová, L

2015-01-01

Hormones exert many actions in the brain. Their access and effects in the brain are regulated by the blood-brain barrier (BBB). Hormones as other substances may enter the brain and vice versa either by paracellular way requiring breaching tight junctions stitching the endothelial cells composing the BBB, or by passage through the cells (transcellular way). Hormones influence both ways through their receptors, both membrane and intracellular, present on/in the BBB. In the review the main examples are outlined how hormones influence the expression and function of proteins forming the tight junctions, as well as how they regulate expression and function of major protein transporters mediating transport of various substances including hormone themselves.
Functional subcellular distribution of β1- and β2-adrenergic receptors in rat ventricular cardiac myocytes

PubMed Central

Cros, Caroline; Brette, Fabien

2013-01-01

β-adrenergic stimulation is a key regulator of cardiac function. The localization of major cardiac adrenergic receptors (β1 and β2) has been investigated using biochemical and biophysical approaches and has led to contradictory results. This study investigates the functional subcellular localization of β1- and β2-adrenergic receptors in rat ventricular myocytes using a physiological approach. Ventricular myocytes were isolated from the hearts of rat and detubulated using formamide. Physiological cardiac function was measured as Ca2+ transient using Fura-2-AM and cell shortening. Selective activation of β1- and β2-adrenergic receptors was induced with isoproterenol (0.1 μmol/L) and ICI-118,551 (0.1 μmol/L); and with salbutamol (10 μmol/L) and atenolol (1 μmol/L), respectively. β1- and β2-adrenergic stimulations induced a significant increase in Ca2+ transient amplitude and cell shortening in intact rat ventricular myocytes (i.e., surface sarcolemma and t-tubules) and in detubulated cells (depleted from t-tubules, surface sarcolemma only). Both β1- and β2-adrenergic receptors stimulation caused a greater effect on Ca2+ transient and cell shortening in detubulated myocytes than in control myocytes. Quantitative analysis indicates that β1-adrenergic stimulation is ∼3 times more effective at surface sarcolemma compared to t-tubules, whereas β2- adrenergic stimulation occurs almost exclusively at surface sarcolemma (∼100 times more effective). These physiological data demonstrate that in rat ventricular myocytes, β1-adrenergic receptors are functionally present at surface sarcolemma and t-tubules, while β2-adrenergic receptors stimulation occurs only at surface sarcolemma of cardiac cells. PMID:24303124
Effects of an herbicide on physiology, morphology, and fitness of the dung beetle Euoniticellus intermedius (Coleoptera: Scarabaeidae).

PubMed

González-Tokman, Daniel; Martínez-Morales, Imelda; Farrera, Arodi; Del Rosario Ortiz-Zayas, María; Lumaret, Jean-Pierre

2017-01-01

Some agrochemical compounds threaten nontarget organisms and their functions in the ecosystem. The authors experimentally evaluated the effects of one of the most common herbicide mixtures used worldwide, containing 2,4-dichlorophenoxyacetic acid and picloram, on dung beetles, which play fundamental roles in the function of natural and managed ecosystems. The present study employed techniques of physiology and geometric morphometrics, besides including fitness measurements, to assess the effects of the herbicide in the introduced beetle Euoniticellus intermedius. Because herbicide components promote oxidative stress and affect survival in certain insects, the authors predicted negative effects on the beetles. Unexpectedly, no effect of herbicide concentration was found on clutch size, sex ratio, and fluctuating asymmetry, and it even increased physiological condition and body size in exposed beetles. Because the studied species presents 2 male morphs, the authors, for the first time, evaluated the effect of a pollutant on the ratio of these morphs. Contrary to the prediction, the herbicide mixture increased the proportion of major males. Thus, the herbicide does not threaten populations of the studied beetles. The present study discusses how both negative and positive effects of pollutants on wild animals modify natural and sexual selection processes occurring in nature, which ultimately impact population dynamics. The authors recommend the use of physiological and geometric morphometrics techniques to assess the impact of pollutants on nontarget animals. Environ Toxicol Chem 2017;36:96-102. © 2016 SETAC. © 2016 SETAC.
Biochemical factors modulating female genital sexual arousal physiology.

PubMed

Traish, Abdulmaged M; Botchevar, Ella; Kim, Noel N

2010-09-01

Female genital sexual arousal responses are complex neurophysiological processes consisting of central and peripheral components that occur following sexual stimulation. The peripheral responses in sexual arousal include genital vasocongestion, engorgement and lubrication resulting from a surge of vaginal and clitoral blood flow. These hemodynamic events are mediated by a host of neurotransmitters and vasoactive agents. To discuss the role of various biochemical factors modulating female genital sexual arousal responses. A comprehensive literature review was conducted using the PubMed database and citations were selected, based on topical relevance, and examined for study methodology and major findings. Data from peer-reviewed publications. Adrenergic as well as non-adrenergic non-cholinergic neurotransmitters play an important role in regulating genital physiological responses by mediating vascular and non-vascular smooth muscle contractility. Vasoactive peptides and neuropeptides also modulate genital sexual responses by regulating vascular and non-vascular smooth muscle cells and epithelial function. The endocrine milieu, particularly sex steroid hormones, is critical in the maintenance of tissue structure and function. Reduced levels of estrogens and androgen are associated with dramatic alterations in genital tissue structure, including the nerve network, as well as the response to physiological modulators. Furthermore, estrogen and androgen deficiency is associated with reduced expression of sex steroid receptors and most importantly with attenuated genital blood flow and lubrication in response to pelvic nerve stimulation. This article provides an integrated framework describing the physiological and molecular basis of various pathophysiological conditions associated with female genital sexual arousal dysfunction. © 2010 International Society for Sexual Medicine.
Task-Related Deactivation and Functional Connectivity of the Subgenual Cingulate Cortex in Major Depressive Disorder

PubMed Central

Davey, Christopher G.; Yücel, Murat; Allen, Nicholas B.; Harrison, Ben J.

2012-01-01

Background: Major depressive disorder is associated with functional alterations in activity and resting-state connectivity of the extended medial frontal network. In this study we aimed to examine how task-related medial network activity and connectivity were affected in depression. Methods: 18 patients with major depressive disorder, aged 15- to 24-years-old, were matched with 19 healthy control participants. We characterized task-related activations and deactivations while participants engaged with an executive-control task (the multi-source interference task, MSIT). We used a psycho-physiological interactions approach to examine functional connectivity changes with subgenual anterior cingulate cortex. Voxel-wise statistical maps for each analysis were compared between the patient and control groups. Results: There were no differences between groups in their behavioral performances on the MSIT task, and nor in patterns of activation and deactivation. Assessment of functional connectivity with the subgenual cingulate showed that depressed patients did not demonstrate the same reduction in functional connectivity with the ventral striatum during task performance, but that they showed greater reduction in functional connectivity with adjacent ventromedial frontal cortex. The magnitude of this latter connectivity change predicted the relative activation of task-relevant executive-control regions in depressed patients. Conclusion: The study reinforces the importance of the subgenual cingulate cortex for depression, and demonstrates how dysfunctional connectivity with ventral brain regions might influence executive–attentional processes. PMID:22403553
Plant Abiotic Stress Proteomics: The Major Factors Determining Alterations in Cellular Proteome

PubMed Central

Kosová, Klára; Vítámvás, Pavel; Urban, Milan O.; Prášil, Ilja T.; Renaut, Jenny

2018-01-01

HIGHLIGHTS: Major environmental and genetic factors determining stress-related protein abundance are discussed.Major aspects of protein biological function including protein isoforms and PTMs, cellular localization and protein interactions are discussed.Functional diversity of protein isoforms and PTMs is discussed. Abiotic stresses reveal profound impacts on plant proteomes including alterations in protein relative abundance, cellular localization, post-transcriptional and post-translational modifications (PTMs), protein interactions with other protein partners, and, finally, protein biological functions. The main aim of the present review is to discuss the major factors determining stress-related protein accumulation and their final biological functions. A dynamics of stress response including stress acclimation to altered ambient conditions and recovery after the stress treatment is discussed. The results of proteomic studies aimed at a comparison of stress response in plant genotypes differing in stress adaptability reveal constitutively enhanced levels of several stress-related proteins (protective proteins, chaperones, ROS scavenging- and detoxification-related enzymes) in the tolerant genotypes with respect to the susceptible ones. Tolerant genotypes can efficiently adjust energy metabolism to enhanced needs during stress acclimation. Stress tolerance vs. stress susceptibility are relative terms which can reflect different stress-coping strategies depending on the given stress treatment. The role of differential protein isoforms and PTMs with respect to their biological functions in different physiological constraints (cellular compartments and interacting partners) is discussed. The importance of protein functional studies following high-throughput proteome analyses is presented in a broader context of plant biology. In summary, the manuscript tries to provide an overview of the major factors which have to be considered when interpreting data from proteomic studies on stress-treated plants. PMID:29472941
Combinations of Physiologic Estrogens with Xenoestrogens Alter ERK Phosphorylation Profiles in Rat Pituitary Cells

PubMed Central

Jeng, Yow-Jiun; Watson, Cheryl S.

2011-01-01

Background Estrogens are potent nongenomic phospho-activators of extracellular-signal–regulated kinases (ERKs). A major concern about the toxicity of xenoestrogens (XEs) is potential alteration of responses to physiologic estrogens when XEs are present simultaneously. Objectives We examined estrogen-induced ERK activation, comparing the abilities of structurally related XEs (alkylphenols and bisphenol A) to alter ERK responses induced by physiologic concentrations (1 nM) of estradiol (E2), estrone (E1), and estriol (E3). Methods We quantified hormone/mimetic-induced ERK phosphorylations in the GH3/B6/F10 rat pituitary cell line using a plate immunoassay, comparing effects with those on cell proliferation and by estrogen receptor subtype-selective ligands. Results Alone, these structurally related XEs activate ERKs in an oscillating temporal pattern similar (but not identical) to that with physiologic estrogens. The potency of all estrogens was similar (active between femtomolar and nanomolar concentrations). XEs potently disrupted physiologic estrogen signaling at low, environmentally relevant concentrations. Generally, XEs potentiated (at the lowest, subpicomolar concentrations) and attenuated (at the highest, picomolar to 100 nM concentrations) the actions of the physiologic estrogens. Some XEs showed pronounced nonmonotonic responses/inhibitions. The phosphorylated ERK and proliferative responses to receptor-selective ligands were only partially correlated. Conclusions XEs are both imperfect potent estrogens and endocrine disruptors; the more efficacious an XE, the more it disrupts actions of physiologic estrogens. This ability to disrupt physiologic estrogen signaling suggests that XEs may disturb normal functioning at life stages where actions of particular estrogens are important (e.g., development, reproductive cycling, pregnancy, menopause). PMID:20870566
Overview of the Anatomy, Physiology, and Pharmacology of the Autonomic Nervous System.

PubMed

Wehrwein, Erica A; Orer, Hakan S; Barman, Susan M

2016-06-13

Comprised of the sympathetic nervous system, parasympathetic nervous system, and enteric nervous system, the autonomic nervous system (ANS) provides the neural control of all parts of the body except for skeletal muscles. The ANS has the major responsibility to ensure that the physiological integrity of cells, tissues, and organs throughout the entire body is maintained (homeostasis) in the face of perturbations exerted by both the external and internal environments. Many commonly prescribed drugs, over-the-counter drugs, toxins, and toxicants function by altering transmission within the ANS. Autonomic dysfunction is a signature of many neurological diseases or disorders. Despite the physiological relevance of the ANS, most neuroscience textbooks offer very limited coverage of this portion of the nervous system. This review article provides both historical and current information about the anatomy, physiology, and pharmacology of the sympathetic and parasympathetic divisions of the ANS. The ultimate aim is for this article to be a valuable resource for those interested in learning the basics of these two components of the ANS and to appreciate its importance in both health and disease. Other resources should be consulted for a thorough understanding of the third division of the ANS, the enteric nervous system. © 2016 American Physiological Society. Compr Physiol 6:1239-1278, 2016. Copyright © 2016 John Wiley & Sons, Inc.
Teaching a changing paradigm in physiology: a historical perspective on gut interstitial cells.

PubMed

Drumm, Bernard T; Baker, Salah A

2017-03-01

The study and teaching of gastrointestinal (GI) physiology necessitates an understanding of the cellular basis of contractile and electrical coupling behaviors in the muscle layers that comprise the gut wall. Our knowledge of the cellular origin of GI motility has drastically changed over the last 100 yr. While the pacing and coordination of GI contraction was once thought to be solely attributable to smooth muscle cells, it is now widely accepted that the motility patterns observed in the GI tract exist as a result of a multicellular system, consisting of not only smooth muscle cells but also enteric neurons and distinct populations of specialized interstitial cells that all work in concert to ensure proper GI functions. In this historical perspective, we focus on the emerging role of interstitial cells in GI motility and examine the key discoveries and experiments that led to a major shift in a paradigm of GI physiology regarding the role of interstitial cells in modulating GI contractile patterns. A review of these now classic experiments and papers will enable students and educators to fully appreciate the complex, multicellular nature of GI muscles as well as impart lessons on how shifting paradigms in physiology are fueled by new technologies that lead to new emerging discoveries. Copyright © 2017 the American Physiological Society.
Effects of anthropogenic noise on endocrine and reproductive function in White's treefrog, Litoria caerulea

PubMed Central

Kaiser, Kristine; Devito, Julia; Jones, Caitlin G.; Marentes, Adam; Perez, Rachel; Umeh, Lisa; Weickum, Regina M.; McGovern, Kathryn E.; Wilson, Emma H.; Saltzman, Wendy

2015-01-01

Urbanization is a major driver of ecological change and comes with a suite of habitat modifications, including alterations to the local temperature, precipitation, light and noise regimes. Although many recent studies have investigated the behavioural and ecological ramifications of urbanization, physiological work in this area has lagged. We tested the hypothesis that anthropogenic noise is a stressor for amphibians and that chronic exposure to such noise leads to reproductive suppression. In the laboratory, we exposed male White's treefrogs, Litoria caerulea, to conspecific chorus noise either alone or coupled with pre-recorded traffic noise nightly for 1 week. Frogs presented with anthropogenic noise had significantly higher circulating concentrations of corticosterone and significantly decreased sperm count and sperm viability than did control frogs. These results suggest that in addition to having behavioural and ecological effects, anthropogenic change might alter physiology and Darwinian fitness. Future work should integrate disparate fields such as behaviour, ecology and physiology to elucidate fully organisms’ responses to habitat change. PMID:27293682
Aquaporins in the kidney: emerging new aspects.

PubMed

Yamamoto, T; Sasaki, S

1998-10-01

Since 1992 and the discovery of an MIP (major intrinsic protein of lens fiber cell) homologue protein that selectively permeates water, aquaporin (AQP), there has been an explosion of research in this field. Early research speculated that aquaporins played indispensible physiological roles in bacteria and plants, as well as in mammalian organs such as red blood cells, kidney, eye, brain and lung, where water transport rapidly takes place. Yet human subjects were identified who lacked AQP1 and yet had no apparent phenotypical changes clinically. To date 10 aquaporins have been discovered and a plethora of MIP members, and their prevalance in almost all organisms is a testament to their indispensible roles in the body, possibly as water and small neutral solute transporting channels. The recent localization of many different aquaporins in the same organ indicates that they may work cooperatively, which may partially explain the mystery of their physiological mechanism. Because the physiological roles of most aquaporins are currently only speculation, more extensive research is necessary to understand the exact function of each aquaporin.
Nitric Oxide-Dependent Posttranslational Modification in Plants: An Update

PubMed Central

Astier, Jeremy; Lindermayr, Christian

2012-01-01

Nitric oxide (NO) has been demonstrated as an essential regulator of several physiological processes in plants. The understanding of the molecular mechanism underlying its critical role constitutes a major field of research. NO can exert its biological function through different ways, such as the modulation of gene expression, the mobilization of second messengers, or interplays with protein kinases. Besides this signaling events, NO can be responsible of the posttranslational modifications (PTM) of target proteins. Several modifications have been identified so far, whereas metal nitrosylation, the tyrosine nitration and the S-nitrosylation can be considered as the main ones. Recent data demonstrate that these PTM are involved in the control of a wide range of physiological processes in plants, such as the plant immune system. However, a great deal of effort is still necessary to pinpoint the role of each PTM in plant physiology. Taken together, these new advances in proteomic research provide a better comprehension of the role of NO in plant signaling. PMID:23203119
Marsupials don't adjust their thermal energetics for life in an alpine environment

PubMed Central

Cooper, Christine E.; Withers, Philip C.; Hardie, Andrew; Geiser, Fritz

2016-01-01

ABSTRACT Marsupials have relatively low body temperatures and metabolic rates, and are therefore considered to be maladapted for life in cold habitats such as alpine environments. We compared body temperature, energetics and water loss as a function of ambient temperature for 4 Antechinus species, 2 from alpine habitats and 2 from low altitude habitats. Our results show that body temperature, metabolic rate, evaporative water loss, thermal conductance and relative water economy are markedly influenced by ambient temperature for each species, as expected for endothermic mammals. However, despite some species and individual differences, habitat (alpine vs non-alpine) does not affect any of these physiological variables, which are consistent with those for other marsupials. Our study suggests that at least under the environmental conditions experienced on the Australian continent, life in an alpine habitat does not require major physiological adjustments by small marsupials and that they are physiologically equipped to deal with sub-zero temperatures and winter snow cover. PMID:28349088
Marsupials don't adjust their thermal energetics for life in an alpine environment.

PubMed

Cooper, Christine E; Withers, Philip C; Hardie, Andrew; Geiser, Fritz

2016-01-01

Marsupials have relatively low body temperatures and metabolic rates, and are therefore considered to be maladapted for life in cold habitats such as alpine environments. We compared body temperature, energetics and water loss as a function of ambient temperature for 4 Antechinus species, 2 from alpine habitats and 2 from low altitude habitats. Our results show that body temperature, metabolic rate, evaporative water loss, thermal conductance and relative water economy are markedly influenced by ambient temperature for each species, as expected for endothermic mammals. However, despite some species and individual differences, habitat (alpine vs non-alpine) does not affect any of these physiological variables, which are consistent with those for other marsupials. Our study suggests that at least under the environmental conditions experienced on the Australian continent, life in an alpine habitat does not require major physiological adjustments by small marsupials and that they are physiologically equipped to deal with sub-zero temperatures and winter snow cover.
Cell structure and function in the visual cortex of the cat

PubMed Central

Kelly, J. P.; Van Essen, D. C.

1974-01-01

1. The organization of the visual cortex was studied with a technique that allows one to determine the physiology and morphology of individual cells. Micro-electrodes filled with the fluorescent dye Procion yellow were used to record intracellularly from cells in area 17 of the cat. The visual receptive field of each neurone was classified as simple, complex, or hypercomplex, and the cell was then stained by the iontophoretic injection of dye. 2. Fifty neurones were successfully examined in this way, and their structural features were compared to the varieties of cell types seen in Golgi preparations of area 17. The majority of simple units were stellate cells, whereas the majority of complex and hypercomplex units were pyramidal cells. Several neurones belonged to less common morphological types, such as double bouquet cells. Simple cells were concentrated in layer IV, hypercomplex cells in layer II + III, and complex cells in layers II + III, V and VI. 3. Electrically inexcitable cells that had high resting potentials but no impulse activity were stained and identified as glial cells. Glial cells responded to visual stimuli with slow graded depolarizations, and many of them showed a preference for a stimulus orientation similar to the optimal orientation for adjacent neurones. 4. The results show that there is a clear, but not absolute correlation between the major structural and functional classes of cells in the visual cortex. This approach, linking the physiological properties of a single cell to a given morphological type, will help in furthering our understanding of the cerebral cortex. ImagesPlate 4Plate 1Plate 2Plate 3 PMID:4136579
Functional Task Test: Data Review

NASA Technical Reports Server (NTRS)

Cromwell, Ronita

2014-01-01

After space flight there are changes in multiple physiological systems including: Cardiovascular function; Sensorimotor function; and Muscle function. How do changes in these physiological system impact astronaut functional performance?
Orgasm in women with spinal cord injuries: a laboratory-based assessment.

PubMed

Sipski, M L; Alexander, C J; Rosen, R C

1995-12-01

To understand the characteristics and physiological sexual responses of women with spinal cord injuries (SCI) during orgasm. Controlled laboratory-based analysis of women's physiological and subjective responses during a single session in which they attempted to perform stimulation to orgasm. The sexual physiology laboratory at our free-standing rehabilitation hospital. A volunteer sample of 25 women with SCI and 10 able-bodied control subjects, matched for age. A 75-minute protocol designed to obtain information on the physiological events accompanying orgasm. Included vaginal pulse amplitude, heart rate, respiration rate, blood pressure, subjective arousal and subscores on the Derogatis Sexual Functioning Inventory (DSFI). Data were analyzed both within and across neurological groups: complete SCI, incomplete SCI, and able-bodied controls. All able-bodied subjects achieved orgasm whereas 52% of SCI subjects achieved orgasm. Degree and type of SCI did not significantly relate to subjects' ability to achieve orgasm. Subjects with no lower extremity function took significantly longer than able-bodied subjects to achieve orgasm. Differences between baseline and orgasm readings are described for each of the major physiological measures. Results of DSFI revealed that able-bodied subjects acknowledged greater sexual satisfaction than SCI subjects. Subjects who achieved orgasm scored higher on sexual information and sex drive. Results support previous self-report studies, in that a large percentage of SCI women achieved orgasm regardless of pattern or degree of neurological injury. No consistent characteristics were identified that would allow prediction of which women with SCI would be able to experience orgasm. However, subjects who achieved orgasms had a higher sex drive and greater sexual knowledge. Implications for sex therapy treatment programs with spinal cord injured women are discussed.

Plant anesthesia supports similarities between animals and plants

PubMed Central

Grémiaux, Alexandre; Yokawa, Ken; Mancuso, Stefano; Baluška, František

2014-01-01

The French scientist Claude Bernard (1813–1878) is famous for his discoveries in physiology and for introducing rigorous experimental methods to medicine and biology. One of his major technical innovations was the use of chemicals in order to disrupt normal physiological function to test hypotheses. But less known is his conviction that the physiological functions of all living organisms rely on the same underlying principles. He hypothesized that similarly to animals, plants are also able to sense changes in their environment. He called this ability “sensitivity.” In order to test his ideas, he performed anesthesia on plants and the results of these experiments were presented in 1878 in “Leçonssur les phénomènes de la vie communs aux animaux et aux végétaux.”1 The phenomena described by Claude Bernard more than a century ago are not fully understood yet. Here, we present a short overview of anesthetic effects in animals and we discuss how anesthesia affects plant movements, seed germination, and photosynthesis. Surprisingly, these phenomena may have ecological relevance, since stressed plants generate anesthetics such as ethylene and ether. Finally, we discuss Claude Bernard's interpretations and conclusions in the perspective of modern plant sciences. PMID:24476640
Physiological relevance of plant 2-Cys peroxiredoxin overoxidation level and oligomerization status.

PubMed

Cerveau, Delphine; Ouahrani, Djelloul; Marok, Mohamed Amine; Blanchard, Laurence; Rey, Pascal

2016-01-01

Peroxiredoxins are ubiquitous thioredoxin-dependent peroxidases presumed to display, upon environmental constraints, a chaperone function resulting from a redox-dependent conformational switch. In this work, using biochemical and genetic approaches, we aimed to unravel the factors regulating the redox status and the conformation of the plastidial 2-Cys peroxiredoxin (2-Cys PRX) in plants. In Arabidopsis, we show that in optimal growth conditions, the overoxidation level mainly depends on the availability of thioredoxin-related electron donors, but not on sulfiredoxin, the enzyme reducing the 2-Cys PRX overoxidized form. We also observed that upon various physiological temperature, osmotic and light stress conditions, the overoxidation level and oligomerization status of 2-Cys PRX can moderately vary depending on the constraint type. Further, no major change was noticed regarding protein conformation in water-stressed Arabidopsis, barley and potato plants, whereas species-dependent up- and down-variations in overoxidation were observed. In contrast, both 2-Cys PRX overoxidation and oligomerization were strongly induced during a severe oxidative stress generated by methyl viologen. From these data, revealing that the oligomerization status of plant 2-Cys PRX does not exhibit important variation and is not tightly linked to the protein redox status upon physiologically relevant environmental constraints, the possible in planta functions of 2-Cys PRX are discussed. © 2015 John Wiley & Sons Ltd.
Employee subjective well-being and physiological functioning: An integrative model

PubMed Central

Tay, Louis

2015-01-01

Research shows that worker subjective well-being influences physiological functioning—an early signal of poor health outcomes. While several theoretical perspectives provide insights on this relationship, the literature lacks an integrative framework explaining the relationship. We develop a conceptual model explaining the link between subjective well-being and physiological functioning in the context of work. Integrating positive psychology and occupational stress perspectives, our model explains the relationship between subjective well-being and physiological functioning as a result of the direct influence of subjective well-being on physiological functioning and of their common relationships with work stress and personal resources, both of which are influenced by job conditions. PMID:28070359
Distinct Physiological Maturation of Parvalbumin-Positive Neuron Subtypes in Mouse Prefrontal Cortex.

PubMed

Miyamae, Takeaki; Chen, Kehui; Lewis, David A; Gonzalez-Burgos, Guillermo

2017-05-10

Parvalbumin-positive (PV + ) neurons control the timing of pyramidal cell output in cortical neuron networks. In the prefrontal cortex (PFC), PV + neuron activity is involved in cognitive function, suggesting that PV + neuron maturation is critical for cognitive development. The two major PV + neuron subtypes found in the PFC, chandelier cells (ChCs) and basket cells (BCs), are thought to play different roles in cortical circuits, but the trajectories of their physiological maturation have not been compared. Using two separate mouse lines, we found that in the mature PFC, both ChCs and BCs are abundant in superficial layer 2, but only BCs are present in deeper laminar locations. This distinctive laminar distribution was observed by postnatal day 12 (P12), when we first identified ChCs by the presence of axon cartridges. Electrophysiology analysis of excitatory synapse development, starting at P12, showed that excitatory drive remains low throughout development in ChCs, but increases rapidly before puberty in BCs, with an earlier time course in deeper-layer BCs. Consistent with a role of excitatory synaptic drive in the maturation of PV + neuron firing properties, the fast-spiking phenotype showed different maturation trajectories between ChCs and BCs, and between superficial versus deep-layer BCs. ChC and BC maturation was nearly completed, via different trajectories, before the onset of puberty. These findings suggest that ChC and BC maturation may contribute differentially to the emergence of cognitive function, primarily during prepubertal development. SIGNIFICANCE STATEMENT Parvalbumin-positive (PV + ) neurons tightly control pyramidal cell output. Thus PV + neuron maturation in the prefrontal cortex (PFC) is crucial for cognitive development. However, the relative physiological maturation of the two major subtypes of PV + neurons, chandelier cells (ChCs) and basket cells (BCs), has not been determined. We assessed the maturation of ChCs and BCs in different layers of the mouse PFC, and found that, from early postnatal age, ChCs and BCs differ in laminar location. Excitatory synapses and fast-spiking properties matured before the onset of puberty in both cell types, but following cell type-specific developmental trajectories. Hence, the physiological maturation of ChCs and BCs may contribute to the emergence of cognitive function differentially, and predominantly during prepubertal development. Copyright © 2017 the authors 0270-6474/17/374883-20$15.00/0.
The Leafhoppers: Anatomy, Physiology and Behavior of Feeding and Its Sensory Mediation

USDA-ARS?s Scientific Manuscript database

The present book contains chapters summarizing all major aspects of the biology of leafhoppers (family Cicadellidae), among the most numerous and important insect pests in the world. Major chapter topics discussed include internal and external morphology, physiology, behavior, reproduction, taxonom...
Physiological changes in neurodegeneration - mechanistic insights and clinical utility.

PubMed

Ahmed, Rebekah M; Ke, Yazi D; Vucic, Steve; Ittner, Lars M; Seeley, William; Hodges, John R; Piguet, Olivier; Halliday, Glenda; Kiernan, Matthew C

2018-05-01

The effects of neurodegenerative syndromes extend beyond cognitive function to involve key physiological processes, including eating and metabolism, autonomic nervous system function, sleep, and motor function. Changes in these physiological processes are present in several conditions, including frontotemporal dementia, amyotrophic lateral sclerosis, Alzheimer disease and the parkinsonian plus conditions. Key neural structures that mediate physiological changes across these conditions include neuroendocrine and hypothalamic pathways, reward pathways, motor systems and the autonomic nervous system. In this Review, we highlight the key changes in physiological processing in neurodegenerative syndromes and the similarities in these changes between different progressive neurodegenerative brain conditions. The changes and similarities between disorders might provide novel insights into the human neural correlates of physiological functioning. Given the evidence that physiological changes can arise early in the neurodegenerative process, these changes could provide biomarkers to aid in the early diagnosis of neurodegenerative diseases and in treatment trials.
Ecosystems Biology Approaches To Determine Key Fitness Traits of Soil Microorganisms

NASA Astrophysics Data System (ADS)

Brodie, E.; Zhalnina, K.; Karaoz, U.; Cho, H.; Nuccio, E. E.; Shi, S.; Lipton, M. S.; Zhou, J.; Pett-Ridge, J.; Northen, T.; Firestone, M.

2014-12-01

The application of theoretical approaches such as trait-based modeling represent powerful tools to explain and perhaps predict complex patterns in microbial distribution and function across environmental gradients in space and time. These models are mostly deterministic and where available are built upon a detailed understanding of microbial physiology and response to environmental factors. However as most soil microorganisms have not been cultivated, for the majority our understanding is limited to insights from environmental 'omic information. Information gleaned from 'omic studies of complex systems should be regarded as providing hypotheses, and these hypotheses should be tested under controlled laboratory conditions if they are to be propagated into deterministic models. In a semi-arid Mediterranean grassland system we are attempting to dissect microbial communities into functional guilds with defined physiological traits and are using a range of 'omics approaches to characterize their metabolic potential and niche preference. Initially, two physiologically relevant time points (peak plant activity and prior to wet-up) were sampled and metagenomes sequenced deeply (600-900 Gbp). Following assembly, differential coverage and nucleotide frequency binning were carried out to yield draft genomes. In addition, using a range of cultivation media we have isolated a broad range of bacteria representing abundant bacterial genotypes and with genome sequences of almost 40 isolates are testing genomic predictions regarding growth rate, temperature and substrate utilization in vitro. This presentation will discuss the opportunities and challenges in parameterizing microbial functional guilds from environmental 'omic information for use in trait-based models.
Surveying N2O-producing pathways in bacteria.

PubMed

Stein, Lisa Y

2011-01-01

Nitrous oxide (N(2)O) is produced by bacteria as an intermediate of both dissimilatory and detoxification pathways under a range of oxygen levels, although the majority of N(2)O is released in suboxic to anoxic environments. N(2)O production under physiologically relevant conditions appears to require the reduction of nitric oxide (NO) produced from the oxidation of hydroxylamine (nitrification), reduction of nitrite (denitrification), or by host cells of pathogenic bacteria. In a single bacterial isolate, N(2)O-producing pathways can be complex, overlapping, involve multiple enzymes with the same function, and require multiple layers of regulatory machinery. This overview discusses how to identify known N(2)O-producing inventory and regulatory sequences within bacterial genome sequences and basic physiological approaches for investigating the function of that inventory. A multitude of review articles have been published on individual enzymes, pathways, regulation, and environmental significance of N(2)O-production encompassing a large diversity of bacterial isolates. The combination of next-generation deep sequencing platforms, emerging proteomics technologies, and basic microbial physiology can be used to expand what is known about N(2)O-producing pathways in individual bacterial species to discover novel inventory and unifying features of pathways. A combination of approaches is required to understand and generalize the function and control of N(2)O production across a range of temporal and spatial scales within natural and host environments. Copyright © 2011 Elsevier Inc. All rights reserved.
The concept of function in modern physiology.

PubMed

Roux, Etienne

2014-06-01

An overview of the scientific literature shows that the concept of function is central in physiology. However, the concept itself is not defined by physiologists. On the other hand, the teleological, namely, the 'goal-directed' dimension of function, and its subsequent explanatory relevance, is a philosophical problem. Intuitively, the function of a trait in a system explains why this trait is present, but, in the early 1960s, Ernest Nagel and Carl Hempel have shown that this inference cannot be logically founded. However, they showed that self-regulated systems are teleological. According to the selectionist theories, the function of an item is its effect that has been selected by natural selection, a process that explains its presence. As they restrict the functional attribution of a trait to its past selective value and not its current properties, these theories are inconsistent with the concept of function in physiology. A more adequate one is the causal role theory, for which a function of a trait in a system is its causal contribution to the functional capacity of the system. However, this leaves unsolved the question of the 'surplus meaning' of the teleological dimension of function. The significance of considering organisms as 'purpose-like' (teleological) systems may reside not in its explanatory power but in its methodological fruitfulness in physiology. In this view, the teleological dimension of physiological functions is convergent to but not imported from, the teleological dimension of evolutionary biology. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.
Structure-Function Relations in Physiology Education: Where's the Mechanism?

ERIC Educational Resources Information Center

Lira, Matthew E.; Gardner, Stephanie M.

2017-01-01

Physiology demands systems thinking: reasoning within and between levels of biological organization and across different organ systems. Many physiological mechanisms explain how structures and their properties interact at one level of organization to produce emergent functions at a higher level of organization. Current physiology principles, such…
When the beachhopper looks at the moon: The moon compass hypothesis

NASA Technical Reports Server (NTRS)

Enright, J. T.

1972-01-01

The function of moon position for shoreline orientation by talitrids is investigated. Three major results were found: (1) Observed cases of compensation for changes in the direction of the moon are based on physiological rhythm with a period of about 25 hours which can persist for at least several days under constant conditions. (2) The zeitgeber for physiological rhythm may be either moonlight or some other factor associated with the tides. (3) If talitrids are long removed from environmental entrainment, either artifically or naturally, the internal rhythm no longer exerts an appreciable influence on the angle of lunar orientation; in such cases the system deteriorates into constant angle orientation, with an angle which is determined by the beach orgin, but may be modified by lighting conditions.
Effect of ionizing radiation on the physiological activities of ethanol extract from hizikia fusiformis cooking drips.

PubMed

Kim, Hyun-Joo; Choi, Jong-il; Kim, Duk-Jin; Kim, Jae-Hun; Soo Chun, Byeong; Hyun Ahn, Dong; Sun Yook, Hong; Byun, Myung-Woo; Kim, Mi-Jung; Shin, Myung-Gon; Lee, Ju-Woon

2009-01-01

Although the byproduct from Hizikia fusiformis industry had many nutrients, it is being wasted. In this study, the physiological activities of cooking drip extracts from H. fusiformis (CDHF) were determined to investigate the effect of a gamma and an electron beam irradiations. DPPH radical scavenging activity and tyrosinase and ACE inhibition effects of the gamma and electron beam irradiated CDHF extracts were increased with increasing irradiation dose. These were reasoned by the increase in the content of the total polyphenolic compound of CDHF by the gamma and electron beam irradiation. There were no differences for the radiation types. These results show that ionizing radiation could be used for enhancing the functional activity of CDHF which is a major by-product in Hizikia fusiformis processing, in various applications.
Effects of microgravity on vestibular ontogeny: direct physiological and anatomical measurements following space flight (STS-29)

NASA Technical Reports Server (NTRS)

Jones, T. A.; Fermin, C.; Hester, P. Y.; Vellinger, J.

1993-01-01

Does space flight change gravity receptor development? The present study measured vestibular form and function in birds flown as embryos for 5 days in earth orbit (STS-29). No major changes in vestibular gross morphology were found. Vestibular response mean amplitudes and latencies were unaffected by space flight. However, the results of measuring vestibular thresholds were mixed and abnormal responses in 3 of the 8 flight animals raise important questions.
Histolocalization and physico-chemical characterization of dihydrochalcones: Insight into the role of apple major flavonoids.

PubMed

Gaucher, Matthieu; Dugé de Bernonville, Thomas; Lohou, David; Guyot, Sylvain; Guillemette, Thomas; Brisset, Marie-Noëlle; Dat, James F

2013-06-01

Flavonoids, like other metabolites synthesized via the phenylpropanoid pathway, possess a wide range of biological activities including functions in plant development and its interaction with the environment. Dihydrochalcones (mainly phloridzin, sieboldin, trilobatin, phloretin) represent the major flavonoid subgroup in apple green tissues. Although this class of phenolic compounds is found in very large amounts in some tissues (≈200mg/g of leaf DW), their physiological significance remains unclear. In the present study, we highlight their tissue-specific localization in young growing shoots suggesting a specific role in important physiological processes, most notably in response to biotic stress. Indeed, dihydrochalcones could constitute a basal defense, in particular phloretin which exhibits a strong broad-range bactericidal and fungicidal activity. Our results also indicate that sieboldin forms complexes with iron with strong affinity, reinforcing its antioxidant properties and conferring to this dihydrochalcone a potential for iron seclusion and/or storage. The importance of localization and biochemical properties of dihydrochalcones are discussed in view of the apple tree defense strategy against both biotic and abiotic stresses. Copyright © 2013 Elsevier Ltd. All rights reserved.
Neuroendocrine control by kisspeptins: role in metabolic regulation of fertility.

PubMed

Navarro, Victor M; Tena-Sempere, Manuel

2011-09-13

The neurohormonal control of reproduction involves a hierarchical network of central and peripheral signals in the hypothalamic-pituitary-gonadal (HPG) axis. Development and function of this neuroendocrine system is the result of a lifelong delicate balance between endogenous regulators and environmental cues, including nutritional and metabolic factors. Kisspeptins are the peptide products of KISS1, which operate via the G-protein-coupled receptor GPR54 (also known as Kiss1R). These peptides have emerged as essential upstream regulators of neurons secreting gonadotropin-releasing hormone (GnRH), the major hypothalamic node for the stimulatory control of the HPG axis. They are potent elicitors of gonadotropin secretion in various species and physiological settings. Moreover, Kiss1 neurons in the hypothalamus participate in crucial features of reproductive maturation and function, such as brain-level sex differentiation, puberty onset and the neuroendocrine regulation of gonadotropin secretion and ovulation. Cotransmitters of Kiss1 neurons, such as neurokinin B, with roles in controlling the HPG axis have been identified by genetic, neuroanatomical and physiological studies. In addition, a putative role has been proposed for Kiss1 neurons in transmitting metabolic information to GnRH neurons, although the precise mechanisms are as yet unclear. In this Review, we present the major reproductive features of kisspeptins, especially their interplay with neurokinin B and potential roles in the metabolic control of puberty and fertility, and suggest new avenues for research.
Physiological and biochemical basis of clinical liver function tests: a review.

PubMed

Hoekstra, Lisette T; de Graaf, Wilmar; Nibourg, Geert A A; Heger, Michal; Bennink, Roelof J; Stieger, Bruno; van Gulik, Thomas M

2013-01-01

To review the literature on the most clinically relevant and novel liver function tests used for the assessment of hepatic function before liver surgery. Postoperative liver failure is the major cause of mortality and morbidity after partial liver resection and develops as a result of insufficient remnant liver function. Therefore, accurate preoperative assessment of the future remnant liver function is mandatory in the selection of candidates for safe partial liver resection. A MEDLINE search was performed using the key words "liver function tests," "functional studies in the liver," "compromised liver," "physiological basis," and "mechanistic background," with and without Boolean operators. Passive liver function tests, including biochemical parameters and clinical grading systems, are not accurate enough in predicting outcome after liver surgery. Dynamic quantitative liver function tests, such as the indocyanine green test and galactose elimination capacity, are more accurate as they measure the elimination process of a substance that is cleared and/or metabolized almost exclusively by the liver. However, these tests only measure global liver function. Nuclear imaging techniques ((99m)Tc-galactosyl serum albumin scintigraphy and (99m)Tc-mebrofenin hepatobiliary scintigraphy) can measure both total and future remnant liver function and potentially identify patients at risk for postresectional liver failure. Because of the complexity of liver function, one single test does not represent overall liver function. In addition to computed tomography volumetry, quantitative liver function tests should be used to determine whether a safe resection can be performed. Presently, (99m)Tc-mebrofenin hepatobiliary scintigraphy seems to be the most valuable quantitative liver function test, as it can measure multiple aspects of liver function in, specifically, the future remnant liver.
The physiological origin of task-evoked systemic artefacts in functional near infrared spectroscopy.

PubMed

Kirilina, Evgeniya; Jelzow, Alexander; Heine, Angela; Niessing, Michael; Wabnitz, Heidrun; Brühl, Rüdiger; Ittermann, Bernd; Jacobs, Arthur M; Tachtsidis, Ilias

2012-05-15

A major methodological challenge of functional near-infrared spectroscopy (fNIRS) is its high sensitivity to haemodynamic fluctuations in the scalp. Superficial fluctuations contribute on the one hand to the physiological noise of fNIRS, impairing the signal-to-noise ratio, and may on the other hand be erroneously attributed to cerebral changes, leading to false positives in fNIRS experiments. Here we explore the localisation, time course and physiological origin of task-evoked superficial signals in fNIRS and present a method to separate them from cortical signals. We used complementary fNIRS, fMRI, MR-angiography and peripheral physiological measurements (blood pressure, heart rate, skin conductance and skin blood flow) to study activation in the frontal lobe during a continuous performance task. The General Linear Model (GLM) was applied to analyse the fNIRS data, which included an additional predictor to account for systemic changes in the skin. We found that skin blood volume strongly depends on the cognitive state and that sources of task-evoked systemic signals in fNIRS are co-localized with veins draining the scalp. Task-evoked superficial artefacts were mainly observed in concentration changes of oxygenated haemoglobin and could be effectively separated from cerebral signals by GLM analysis. Based on temporal correlation of fNIRS and fMRI signals with peripheral physiological measurements we conclude that the physiological origin of the systemic artefact is a task-evoked sympathetic arterial vasoconstriction followed by a decrease in venous volume. Since changes in sympathetic outflow accompany almost any cognitive and emotional process, we expect scalp vessel artefacts to be present in a wide range of fNIRS settings used in neurocognitive research. Therefore a careful separation of fNIRS signals originating from activated brain and from scalp is a necessary precondition for unbiased fNIRS brain activation maps. Copyright © 2012 Elsevier Inc. All rights reserved.
Non-invasive reproductive and stress endocrinology in amphibian conservation physiology

PubMed Central

Narayan, E. J.

2013-01-01

Non-invasive endocrinology utilizes non-invasive biological samples (such as faeces, urine, hair, aquatic media, and saliva) for the quantification of hormones in wildlife. Urinary-based enzyme immunoassay (EIA) and radio-immunoassay have enabled the rapid quantification of reproductive and stress hormones in amphibians (Anura: Amphibia). With minimal disturbance, these methods can be used to assess the ovarian and testicular endocrine functions as well as physiological stress in captive and free-living populations. Non-invasive endocrine monitoring has therefore greatly advanced our knowledge of the functioning of the stress endocrine system (the hypothalamo–pituitary–interrenal axis) and the reproductive endocrine system (the hypothalamo–pituitary–gonadal axis) in the amphibian physiological stress response, reproductive ecology, health and welfare, and survival. Biological (physiological) validation is necessary for obtaining the excretory lag time of hormone metabolites. Urinary-based EIA for the major reproductive hormones, estradiol and progesterone in females and testosterone in males, can be used to track the reproductive hormone profiles in relationship to reproductive behaviour and environmental data in free-living anurans. Urinary-based corticosterone metabolite EIA can be used to assess the sublethal impacts of biological stressors (such as invasive species and pathogenic diseases) as well as anthropogenic induced environmental stressors (e.g. extreme temperatures) on free-living populations. Non-invasive endocrine methods can also assist in the diagnosis of success or failure of captive breeding programmes by measuring the longitudinal patterns of changes in reproductive hormones and corticosterone within captive anurans and comparing the endocrine profiles with health records and reproductive behaviour. This review paper focuses on the reproductive and the stress endocrinology of anurans and demonstrates the uses of non-invasive endocrinology for advancing amphibian conservation physiology. It also provides key technical considerations for future research that will increase the accuracy and reliability of the data and the value of non-invasive endocrinology within the conceptual framework of conservation physiology. PMID:27293595
Measuring Dynamic Kidney Function in an Undergraduate Physiology Laboratory

ERIC Educational Resources Information Center

Medler, Scott; Harrington, Frederick

2013-01-01

Most undergraduate physiology laboratories are very limited in how they treat renal physiology. It is common to find teaching laboratories equipped with the capability for high-resolution digital recordings of physiological functions (muscle twitches, ECG, action potentials, respiratory responses, etc.), but most urinary laboratories still rely on…
In-depth physiological characterization of primary human hepatocytes in a 3D hollow-fiber bioreactor.

PubMed

Mueller, Daniel; Tascher, Georg; Müller-Vieira, Ursula; Knobeloch, Daniel; Nuessler, Andreas K; Zeilinger, Katrin; Heinzle, Elmar; Noor, Fozia

2011-08-01

As the major research focus is shifting to three-dimensional (3D) cultivation techniques, hollow-fiber bioreactors, allowing the formation of tissue-like structures, show immense potential as they permit controlled in vitro cultivation while supporting the in vivo environment. In this study we carried out a systematic and detailed physiological characterization of human liver cells in a 3D hollow-fiber bioreactor system continuously run for > 2 weeks. Primary human hepatocytes were maintained viable and functional over the whole period of cultivation. Both general cellular functions, e.g. oxygen uptake, amino acid metabolism and substrate consumption, and liver-specific functions, such as drug-metabolizing capacities and the production of liver-specific metabolites were found to be stable for > 2 weeks. As expected, donor-to-donor variability was observed in liver-specific functions, namely urea and albumin production. Moreover, we show the maintenance of primary human hepatocytes in serum-free conditions in this set-up. The stable basal cytochrome P450 activity 3 weeks after isolation of the cells demonstrates the potential of such a system for pharmacological applications. Liver cells in the presented 3D bioreactor system could eventually be used not only for long-term metabolic and toxicity studies but also for chronic repeated dose toxicity assessment. Copyright © 2011 John Wiley & Sons, Ltd.

Elucidating the functional role of endoreduplication in tomato fruit development

PubMed Central

Chevalier, Christian; Nafati, Mehdi; Mathieu-Rivet, Elodie; Bourdon, Matthieu; Frangne, Nathalie; Cheniclet, Catherine; Renaudin, Jean-Pierre; Gévaudant, Frédéric; Hernould, Michel

2011-01-01

Background Endoreduplication is the major source of endopolyploidy in higher plants. The process of endoreduplication results from the ability of cells to modify their classical cell cycle into a partial cell cycle where DNA synthesis occurs independently from mitosis. Despite the ubiquitous occurrence of the phenomenon in eukaryotic cells, the physiological meaning of endoreduplication remains vague,although several roles during plant development have been proposed, mostly related to cell differentiation and cell size determination. Scope Here recent advances in the knowledge of endoreduplication and fruit organogenesis are reviewed, focusing on tomato (Solanum lycopersicum) as a model, and the functional analyses of endoreduplication-associated regulatory genes in tomato fruit are described. Conclusions The cyclin-dependent kinase inhibitory kinase WEE1 and the anaphase promoting complex activator CCS52A both participate in the control of cell size and the endoreduplication process driving cell expansion during early fruit development in tomato. Moreover the fruit-specific functional analysis of the tomato CDK inhibitor KRP1 reveals that cell size and fruit size determination can be uncoupled from DNA ploidy levels, indicating that endoreduplication acts rather as a limiting factor for cell growth. The overall functional data contribute to unravelling the physiological role of endoreduplication in growth induction of fleshy fruits. PMID:21199834
A worldwide analysis of within-canopy variations in leaf structural, chemical and physiological traits across plant functional types

PubMed Central

Niinemets, Ülo; Keenan, Trevor F.; Hallik, Lea

2018-01-01

Summary Extensive within-canopy light gradients importantly affect photosynthetic productivity of leaves in different canopy positions and lead to light-dependent increases in foliage photosynthetic capacity per area (AA). However, the controls on AA variations by changes in underlying traits are poorly known. We constructed an unprecedented worldwide database including 831 within-canopy gradients with standardized light estimates for 304 species belonging to major vascular plant functional types, and analyzed within-canopy variations in 12 key foliage structural, chemical and physiological traits by quantitatively separating the contributions of different traits to photosynthetic acclimation. Although the light-dependent increase in AA is surprisingly similar in different plant functional types, they fundamentally differ in the share of the controls on AA by constituent traits. Species with high rates of canopy development and leaf turnover exhibiting highly dynamic light environments, actively change AA by nitrogen reallocation among and partitioning within leaves. In contrast, species with slow leaf turnover exhibit a passive AA acclimation response primarily determined by acclimation of leaf structure to growth light. This review emphasizes that different combinations of traits are responsible for within-canopy photosynthetic acclimation in different plant functional types and solves an old enigma of the role of mass- vs. area-based traits in vegetation acclimation. PMID:25318596
Worldwide variation in within-canopy photosynthetic acclimation: differences in temporal and environmental controls among plant functional types

NASA Astrophysics Data System (ADS)

Niinemets, Ülo; Keenan, Trevor

2017-04-01

Major light gradients, characteristically 10- to 50-fold, constitute the most prominent feature of plant canopies. These gradients drive within-canopy variation in foliage structural, chemical and physiological traits. As a key acclimation response to variation in light availability, foliage photosynthetic capacity per area (Aarea) increases with increasing light availability within the canopy, maximizing whole canopy photosynthesis. Recently, a worldwide database including 831 within-canopy gradients with standardized light estimates for 304 species belonging to major vascular plant functional types was constructed and within-canopy variation in photosynthetic acclimation was characterized (Niinemets Ü, Keenan TF, Hallik L (2015) Tansley review. A worldwide analysis of within-canopy variations in leaf structural, chemical and physiological traits across plant functional types. The New Phytologist 205: 973-993). However, the understanding of how within-canopy photosynthetic gradients vary during the growing season and in response to site and stand characteristics is still limited. Here we analyzed temporal, environmental and site (nutrient availability, stand density, ambient CO2 concentration, water availability) sources of variation in within-canopy photosynthetic acclimation in different plant functional types. Variation in key structural (leaf dry mass per unit area, MA), chemical (nitrogen content per dry mass, NM, and area, NA) and physiological (photosynthetic nitrogen use efficiency, EN) photosynthetic capacity per dry mass, Amass and area, Aarea) was examined. The analysis demonstrates major, typically 1.5-2-fold, time-, environment and site-dependent modifications in within-canopy variation in foliage photosynthetic capacity. However, the magnitude and direction of temporal and environmental variations in plasticity significantly varied among functional types. Species with longer leaf life span and low rates of canopy expansion or flush-type canopy formation had lower within canopy plasticity during the growing season and in response to environmental and site modifications than species with high rates of canopy expansion and leaf turnover. The fast canopy-expanding species that grow in highly dynamic light environments, actively modified Aarea by nitrogen reallocation among and partitioning within leaves. In contrast, species with low rate of leaf turnover generally exhibited a passive acclimation response with variation in Aarea primarily determined by light-dependent modifications in leaf structure during leaf growth. Due to limited reacclimation capacity in species with low leaf turnover, within-canopy variation in Aarea decreased with increasing leaf age in these species. Furthermore, the plasticity responded less to modifications in environmental and site characteristics than in species with faster leaf turnover. This analysis concludes that the rate of leaf turnover is the key trait determining the temporal variation and environmental responses of canopy photosynthetic acclimation.
POMC Neurons: From Birth to Death

PubMed Central

Toda, Chitoku; Santoro, Anna; Kim, Jung Dae

2017-01-01

The hypothalamus is an evolutionarily conserved brain structure that regulates an organism’s basic functions, such as homeostasis and reproduction. Several hypothalamic nuclei and neuronal circuits have been the focus of many studies to understand their role in regulating these basic functions. Within the hypothalamic neuronal populations, the arcuate melanocortin system plays a major role in controlling homeostatic functions. The arcuate pro-opiomelanocortin (POMC) neurons in particular have been shown to be critical regulators of metabolism and reproduction because of their projections to several brain areas both in and outside of the hypothalamus, such as autonomic regions of the brain stem and spinal cord. Here, we review and discuss the current understanding of POMC neurons from their development and intracellular regulators to their physiological functions and pathological dysregulation. PMID:28192062
Physiological and functional consequences of caregiving for relatives with dementia

PubMed Central

Fonareva, Irina; Oken, Barry S.

2014-01-01

Background Chronic stress negatively affects health and well-being. A growing population of informal dementia caregivers experience chronic stress associated with extraordinary demands of caring for a relative with dementia. This review summarizes physiological and functional changes due to chronic dementia caregiver stress. Methods A literature search for papers assessing effects of dementia caregiving was conducted focusing on publications evaluating differences between caregivers and non-caregivers in objective measures of health and cognition. Results The review identified 37 studies describing data from 4145 participants including 749 dementia caregivers and 3396 non-caregiver peers. Objective outcome measures affected in dementia caregivers included markers of dyscoagulation, inflammation, and cell aging as well as measures of immune function, sleep, and cognition. Though diverse in designs, samples, and study quality, the majority of the studies indicated increased vulnerability of dementia caregivers to detrimental changes in health and cognition. Demographic and personality characteristics moderating or mediating effects of chronic stress in caregivers were also reviewed. Conclusions There is accumulating evidence that chronic dementia caregiver stress increases their vulnerability to disease and diminishes their ability to provide optimal care. Clinicians and society need to appreciate the extent of deleterious effects of chronic stress on dementia caregiver health. PMID:24507463
Dynamic physiological modeling for functional diffuse optical tomography

PubMed Central

Diamond, Solomon Gilbert; Huppert, Theodore J.; Kolehmainen, Ville; Franceschini, Maria Angela; Kaipio, Jari P.; Arridge, Simon R.; Boas, David A.

2009-01-01

Diffuse optical tomography (DOT) is a noninvasive imaging technology that is sensitive to local concentration changes in oxy- and deoxyhemoglobin. When applied to functional neuroimaging, DOT measures hemodynamics in the scalp and brain that reflect competing metabolic demands and cardiovascular dynamics. The diffuse nature of near-infrared photon migration in tissue and the multitude of physiological systems that affect hemodynamics motivate the use of anatomical and physiological models to improve estimates of the functional hemodynamic response. In this paper, we present a linear state-space model for DOT analysis that models the physiological fluctuations present in the data with either static or dynamic estimation. We demonstrate the approach by using auxiliary measurements of blood pressure variability and heart rate variability as inputs to model the background physiology in DOT data. We evaluate the improvements accorded by modeling this physiology on ten human subjects with simulated functional hemodynamic responses added to the baseline physiology. Adding physiological modeling with a static estimator significantly improved estimates of the simulated functional response, and further significant improvements were achieved with a dynamic Kalman filter estimator (paired t tests, n = 10, P < 0.05). These results suggest that physiological modeling can improve DOT analysis. The further improvement with the Kalman filter encourages continued research into dynamic linear modeling of the physiology present in DOT. Cardiovascular dynamics also affect the blood-oxygen-dependent (BOLD) signal in functional magnetic resonance imaging (fMRI). This state-space approach to DOT analysis could be extended to BOLD fMRI analysis, multimodal studies and real-time analysis. PMID:16242967
Complete identification of E-selectin ligands on neutrophils reveals distinct functions of PSGL-1, ESL-1, and CD44.

PubMed

Hidalgo, Andrés; Peired, Anna J; Wild, Martin; Vestweber, Dietmar; Frenette, Paul S

2007-04-01

The selectins and their ligands are required for leukocyte extravasation during inflammation. Several glycoproteins have been suggested to bind to E-selectin in vitro, but the complete identification of its physiological ligands has remained elusive. Here, we showed that E-selectin ligand-1 (ESL-1), P-selectin glycoprotein ligand-1 (PSGL-1), and CD44 encompassed all endothelial-selectin ligand activity on neutrophils by using gene- and RNA-targeted loss of function. PSGL-1 played a major role in the initial leukocyte capture, whereas ESL-1 was critical for converting initial tethers into steady slow rolling. CD44 controlled rolling velocity and mediated E-selectin-dependent redistribution of PSGL-1 and L-selectin to a major pole on slowly rolling leukocytes through p38 signaling. These results suggest distinct and dynamic contributions of these three glycoproteins in selectin-mediated neutrophil adhesion and signaling.
Complete identification of E-selectin ligand activity on neutrophils reveals a dynamic interplay and distinct functions of PSGL-1, ESL-1 and CD44

PubMed Central

Wild, Martin; Vestweber, Dietmar; Frenette, Paul S.

2014-01-01

SUMMARY The selectins and their ligands are required for leukocyte extravasation during inflammation. Several glycoproteins have been suggested to bind to E-selectin in vitro but the complete identification of its physiological ligands has remained elusive. Here, we show using gene- and RNA-targeted loss-of-function that E-selectin ligand-1 (ESL-1), PSGL-1 and CD44 encompass all endothelial selectin ligand activity on neutrophils. PSGL-1 plays a major role in the initial leukocyte capture, while ESL-1 is critical to convert initial tethers into steady slow rolling. CD44 controls rolling velocity and mediates E-selectin-dependent redistribution of PSGL-1 and L-selectin to a major pole on slowly rolling leukocytes through p38 signaling. These results suggest distinct and dynamic contributions of these three glycoproteins in selectin-mediated neutrophil adhesion and signaling. PMID:17442598
Arenaviruses. Genes, proteins, and expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oldstone, M.B.A.

1987-01-01

This book provides a discussion of current knowledge on Arenaviruses. These viruses are the cause of major health problems, such as Lassa fever and Junin virus disease, and have been the Rosetta stone on which many of the major concepts in viral pathogenesis and immunobiology have been built. For example, study of lymphocytic choriomeningitis naturally and experimentally induced infection in the normal mouse host presented the scientific community with the first and definitive work on the following topics: virus induced immune response disease, immunologic tolerance, virus induced immune complex disease, presence and generation of cytotoxic T cells in vitro andmore » in vivo, H-2 restriction and dual recognition phenomena, and viral disease induced by altering physiologic or differential functions of a cell without causing alterations of house keeping or vital functions, i.e. pathology in the absence of cell or tissue lysis.« less
Pericyte function in the physiological central nervous system.

PubMed

Muramatsu, Rieko; Yamashita, Toshihide

2014-01-01

Damage to the central nervous system (CNS) leads to disruption of the vascular network, causing vascular dysfunction. Vascular dysfunction is the major event in the pathogenesis of CNS diseases and is closely associated with the severity of neuronal dysfunction. The suppression of vascular dysfunction has been considered a promising avenue to limit damage to the CNS, leading to efforts to clarify the cellular and molecular basis of vascular homeostasis maintenance. A reduction of trophic support and oxygen delivery due to circulatory insufficiency has long been regarded as a major cause of vascular damage. Moreover, recent studies provide a new perspective on the importance of the structural stability of blood vessels in CNS diseases. This updated article discusses emerging information on the key role of vascular integrity in CNS diseases, specially focusing on pericyte function. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.
A structure-function analysis of ion transport in crustacean gills and excretory organs.

PubMed

Freire, Carolina A; Onken, Horst; McNamara, John C

2008-11-01

Osmotic and ionic regulation in the Crustacea is mostly accomplished by the multifunctional gills, together with the excretory organs. In addition to their role in gas exchange, the gills constitute organs of active, transepithelial, ion transport, an activity of major importance that underlies many essential physiological functions like osmoregulation, calcium homeostasis, ammonium excretion and extracellular pH regulation. This review focuses on structure-function relationships in crustacean gills and excretory effectors, from the organ to molecular levels of organization. We address the diversity of structural architectures encountered in different crustacean gill types, and in constituent cell types, before examining the physiological mechanisms of Na(+), Cl(-), Ca(2+) and NH(4)(+) transport, and of acid-base equivalents, based on findings obtained over the last two decades employing advanced techniques. The antennal and maxillary glands constitute the principal crustacean excretory organs, which have received less attention in functional studies. We examine the diversity present in antennal and maxillary gland architecture, highlighting the structural similarities between both organ types, and we analyze the functions ascribed to each glandular segment. Emphasis is given to volume and osmoregulatory functions, capacity to produce dilute urine in freshwater crustaceans, and the effect of acclimation salinity on urine volume and composition. The microanatomy and diversity of function ascribed to gills and excretory organs are appraised from an evolutionary perspective, and suggestions made as to future avenues of investigation that may elucidate evolutionary and adaptive trends underpinning the invasion and exploitation of novel habitats.
Autophagy in health and disease: focus on the cardiovascular system.

PubMed

Mialet-Perez, Jeanne; Vindis, Cécile

2017-12-12

Autophagy is a highly conserved mechanism of lysosome-mediated protein and organelle degradation that plays a crucial role in maintaining cellular homeostasis. In the last few years, specific functions for autophagy have been identified in many tissues and organs. In the cardiovascular system, autophagy appears to be essential to heart and vessel homeostasis and function; however defective or excessive autophagy activity seems to contribute to major cardiovascular disorders including heart failure (HF) or atherosclerosis. Here, we review the current knowledge on the role of cardiovascular autophagy in physiological and pathophysiological conditions. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.
Physiology of chimpanzees in orbit. Part 1: Scientific Report

NASA Technical Reports Server (NTRS)

Firstenberg, A.; Mcnew, J.

1972-01-01

Major achievements and accomplishments are reported for the Physiology of Chimpanzees in Orbit Program. Scientific studies relate to behavior and physiology, and engineering studies cover telemetry, behavioral training, systems tests, life support subsystems, and program plan.
Morphological dynamics of mitochondria--a special emphasis on cardiac muscle cells.

PubMed

Hom, Jennifer; Sheu, Shey-Shing

2009-06-01

Mitochondria play a critical role in cellular energy metabolism, Ca(2+) homeostasis, reactive oxygen species generation, apoptosis, aging, and development. Many recent publications have shown that a continuous balance of fusion and fission of these organelles is important in maintaining their proper function. Therefore, there is a steep correlation between the form and function of mitochondria. Many major proteins involved in mitochondrial fusion and fission have been identified in different cell types, including heart. However, the functional role of mitochondrial dynamics in the heart remains, for the most part, unexplored. In this review we will cover the recent field of mitochondrial dynamics and its physiological and pathological implications, with a particular emphasis on the experimental and theoretical basis of mitochondrial dynamics in the heart.
Rehabilitation after stroke.

PubMed

Knecht, Stefan; Hesse, Stefan; Oster, Peter

2011-09-01

Stroke is becoming more common in Germany as the population ages. Its long-term sequelae can be alleviated by early reperfusion in stroke units and by complication management and functional restoration in early-rehabilitation and rehabilitation centers. Selective review of the literature. Successful rehabilitation depends on systematic treatment by an interdisciplinary team of experienced specialists. In the area of functional restoration, there has been major progress in our understanding of the physiology of learning, relearning, training, and neuroenhancement. There have also been advances in supportive pharmacotherapy and robot technology. Well-organized acute and intermediate rehabilitation after stroke can provide patients with the best functional results attainable on the basis of our current scientific understanding. Further experimental and clinical studies will be needed to expand our knowledge and improve the efficacy of rehabilitation.
Spacelab mission 4 - The first dedicated life sciences mission

NASA Technical Reports Server (NTRS)

Perry, T. W.; Reid, D. H.

1983-01-01

Plans for the first Spacelab-4 mission dedicated entirely to the life sciences, are reviewed. The thrust of the scientific mission scheduled for late 1985 will be to study the acute effects of weightlessness on living systems, particularly humans. The payload of the Spacelab compartment will contain 24 experiments of which approximately half will involve humans. Among the major areas of interest are cardiovascular and pulmonary function, vestibular function, renal and endocrine physiology, hematology, nitrogen balance, immunological function, the gravitational biology of plants, inflight fertilization of frogs' eggs and the effects of zero gravity on monkeys and rats. In selecting the array of experiments an effort was made to combine investigations with complementary scientific objectives to develop animal models of human biological problems.
Sexual Functioning in Men Living with a Spinal Cord Injury-A Narrative Literature Review.

PubMed

Sunilkumar, M M; Boston, Patricia; Rajagopal, M R

2015-01-01

Sexual dysfunction is a major concern for Indian men living with a spinal cord injury. To examine the literature related to sexuality traumatic cord injury and its impact on sexual functioning. Databases using Cumulative Index to Nursing and Allied Health Literature (CINAHL) 2000-2012, Medline 1989-2012, Applied Social Sciences Index and Abstracts (ASSIA) 1989-2012 and Google Scholar were the search engines used used for literature review. The search yielded a total of 457 articles and only 75 of them were found relevant. The minimum number of articles required to meet the inclusion criteria for this review was 25-30 articles. Out of the 75 articles, 33 were considered relevant or related to the topic of sexual functioning, spinal cord injury, and paraplegia. Six areas were identified: Sexual stigmatization, physiological barriers to sexual satisfaction, clinical aspects of sexual functioning, biomedical approaches to sexual dysfunction, partner satisfaction, and lack of accessibility to sexual education. Spinal cord injury and sexual functioning affects a large segment of the male Indian population, yet most current research focuses on quantitative measurement with the emphasis on ejaculatory dysfunction, orgasm impairment, incontinence, and other physiological dysfunction. Further research is needed to address the subjective accounts of patients themselves with respect to the emotional and social impact of sexual disability. This would help to identify the best possible outcomes for both treatment and rehabilitation.
Integrative Identification of Arabidopsis Mitochondrial Proteome and Its Function Exploitation through Protein Interaction Network

PubMed Central

Cui, Jian; Liu, Jinghua; Li, Yuhua; Shi, Tieliu

2011-01-01

Mitochondria are major players on the production of energy, and host several key reactions involved in basic metabolism and biosynthesis of essential molecules. Currently, the majority of nucleus-encoded mitochondrial proteins are unknown even for model plant Arabidopsis. We reported a computational framework for predicting Arabidopsis mitochondrial proteins based on a probabilistic model, called Naive Bayesian Network, which integrates disparate genomic data generated from eight bioinformatics tools, multiple orthologous mappings, protein domain properties and co-expression patterns using 1,027 microarray profiles. Through this approach, we predicted 2,311 candidate mitochondrial proteins with 84.67% accuracy and 2.53% FPR performances. Together with those experimental confirmed proteins, 2,585 mitochondria proteins (named CoreMitoP) were identified, we explored those proteins with unknown functions based on protein-protein interaction network (PIN) and annotated novel functions for 26.65% CoreMitoP proteins. Moreover, we found newly predicted mitochondrial proteins embedded in particular subnetworks of the PIN, mainly functioning in response to diverse environmental stresses, like salt, draught, cold, and wound etc. Candidate mitochondrial proteins involved in those physiological acitivites provide useful targets for further investigation. Assigned functions also provide comprehensive information for Arabidopsis mitochondrial proteome. PMID:21297957
Thermal Stress

DTIC Science & Technology

2011-01-01

can have a significant impact on normal physiological functioning if precipitous increases in core temperature are not adequately controlled with...anterior hypothalamusIntroduction Thermal stress can have a significant impact on normal physiological functioning if precipitous increases in core...fat and skin). The regulation of a relatively constant internal temperature is critical for normal physiological functioning of tissues and cells, as
THE ANATOMIC SITE OF THE TRANSEPITHELIAL PERMEABILITY BARRIERS OF TOAD BLADDER

PubMed Central

DiBona, Donald R.; Civan, Mortimer M.; Leaf, Alexander

1969-01-01

An examination of the mucosal epithelium of the urinary bladder of the toad reveals that the two major cell types which abut on the urinary surface, the granular and mitochondria-rich cells, also contact the basement membrane. Thus, the epithelium functions as a single cell layer. Although basal cells are interpolated between the granular cells and the basement membrane over a large portion of the epithelium, they do not constitute an additional continuous cell layer. This finding is consistent with extensive physiological data which had assumed that the major permeability barriers of this epithelium were the apical and basal-lateral plasma membranes of a single layer of cells. PMID:5782445

Career Opportunities in Physiology: Careers for Physiologists in Departments of Biological and Animal Sciences.

ERIC Educational Resources Information Center

Gregg, Christine M.

1985-01-01

Analyzes data from an American Physiological Society survey on 88 physiology programs not associated with medical schools. Included are enrollment data and data on faculty characteristics, areas of specialization, and doctorates awarded. Indicates that the majority of physiology PhD programs are located within departments of biological sciences.…
Mitochondrial transport in neurons: impact on synaptic homeostasis and neurodegeneration

PubMed Central

Sheng, Zu-Hang; Cai, Qian

2016-01-01

Mitochondria have a number of essential roles in neuronal function. Their complex mobility patterns within neurons are characterized by frequent changes in direction. Mobile mitochondria can become stationary or pause in regions that have a high metabolic demand and can move again rapidly in response to physiological changes. Defects in mitochondrial transport are implicated in the pathogenesis of several major neurological disorders. Research into the mechanisms that regulate mitochondrial transport is thus an important emerging frontier. PMID:22218207
Platelets and their interactions with other immune cells

PubMed Central

Lam, Fong W.; Vijayan, K. Vinod; Rumbaut, Rolando E.

2015-01-01

Platelets are anucleate blood cells, long known to be critically involved in hemostasis and thrombosis. In addition to their role in blood clots, increasing evidence reveals significant roles for platelets in inflammation and immunity. However, the notion that platelets represent immune cells is not broadly recognized in the field of Physiology. This manuscript reviews the role of platelets in inflammation and immune responses, and highlights their interactions with other immune cells, including examples of major functional consequences of these interactions. PMID:26140718
Relevance of deprivation studies in understanding rapid eye movement sleep

PubMed Central

Mehta, Rachna; Khan, Shafa; Mallick, Birendra N

2018-01-01

Rapid eye movement sleep (REMS) is a unique phenomenon essential for maintaining normal physiological processes and is expressed at least in species higher in the evolution. The basic scaffold of the neuronal network responsible for REMS regulation is present in the brainstem, which may be directly or indirectly influenced by most other physiological processes. It is regulated by the neurons in the brainstem. Various manipulations including chemical, elec-trophysiological, lesion, stimulation, behavioral, ontogenic and deprivation studies have been designed to understand REMS genesis, maintenance, physiology and functional significance. Although each of these methods has its significance and limitations, deprivation studies have contributed significantly to the overall understanding of REMS. In this review, we discuss the advantages and limitations of various methods used for REMS deprivation (REMSD) to understand neural regulation and physiological significance of REMS. Among the deprivation strategies, the flowerpot method is by far the method of choice because it is simple and convenient, exploits physiological parameter (muscle atonia) for REMSD and allows conducting adequate controls to overcome experimental limitations as well as to rule out nonspecific effects. Notwithstanding, a major criticism that the flowerpot method faces is that of perceived stress experienced by the experimental animals. Nevertheless, we conclude that like most methods, particularly for in vivo behavioral studies, in spite of a few limitations, given the advantages described above, the flowerpot method is the best method of choice for REMSD studies. PMID:29881316
Nitric oxide: a physiologic messenger.

PubMed

Lowenstein, C J; Dinerman, J L; Snyder, S H

1994-02-01

To review the physiologic role of nitric oxide, an unusual messenger molecule that mediates blood vessel relaxation, neurotransmission, and pathogen suppression. A MEDLINE search of articles published from 1987 to 1993 that addressed nitric oxide and the enzyme that synthesizes it, nitric oxide synthase. Animal and human studies were selected from 3044 articles to analyze the clinical importance of nitric oxide. Descriptions of the structure and function of nitric oxide synthase were selected to show how nitric oxide acts as a biological messenger molecule. Biochemical and physiologic studies were analyzed if the same results were found by three or more independent observers. Two major classes of nitric oxide synthase enzymes produce nitric oxide. The constitutive isoforms found in endothelial cells and neurons release small amounts of nitric oxide for brief periods to signal adjacent cells, whereas the inducible isoform found in macrophages releases large amounts of nitric oxide continuously to eliminate bacteria and parasites. By diffusing into adjacent cells and binding to enzymes that contain iron, nitric oxide plays many important physiologic roles. It regulates blood pressure, transmits signals between neurons, and suppresses pathogens. Excess amounts, however, can damage host cells, causing neurotoxicity during strokes and causing the hypotension associated with sepsis. Nitric oxide is a simple molecule with many physiologic roles in the cardiovascular, neurologic, and immune systems. Although the general principles of nitric oxide synthesis are known, further research is necessary to determine what role it plays in causing disease.
Relevance of deprivation studies in understanding rapid eye movement sleep.

PubMed

Mehta, Rachna; Khan, Shafa; Mallick, Birendra N

2018-01-01

Rapid eye movement sleep (REMS) is a unique phenomenon essential for maintaining normal physiological processes and is expressed at least in species higher in the evolution. The basic scaffold of the neuronal network responsible for REMS regulation is present in the brainstem, which may be directly or indirectly influenced by most other physiological processes. It is regulated by the neurons in the brainstem. Various manipulations including chemical, elec-trophysiological, lesion, stimulation, behavioral, ontogenic and deprivation studies have been designed to understand REMS genesis, maintenance, physiology and functional significance. Although each of these methods has its significance and limitations, deprivation studies have contributed significantly to the overall understanding of REMS. In this review, we discuss the advantages and limitations of various methods used for REMS deprivation (REMSD) to understand neural regulation and physiological significance of REMS. Among the deprivation strategies, the flowerpot method is by far the method of choice because it is simple and convenient, exploits physiological parameter (muscle atonia) for REMSD and allows conducting adequate controls to overcome experimental limitations as well as to rule out nonspecific effects. Notwithstanding, a major criticism that the flowerpot method faces is that of perceived stress experienced by the experimental animals. Nevertheless, we conclude that like most methods, particularly for in vivo behavioral studies, in spite of a few limitations, given the advantages described above, the flowerpot method is the best method of choice for REMSD studies.
Oxygen matters: tissue culture oxygen levels affect mitochondrial function and structure as well as responses to HIV viroproteins.

PubMed

Tiede, L M; Cook, E A; Morsey, B; Fox, H S

2011-12-22

Mitochondrial dysfunction is implicated in a majority of neurodegenerative disorders and much study of neurodegenerative disease is done on cultured neurons. In traditional tissue culture, the oxygen level that cells experience is dramatically higher (21%) than in vivo conditions (1-11%). These differences can alter experimental results, especially, pertaining to mitochondria and oxidative metabolism. Our results show that primary neurons cultured at physiological oxygen levels found in the brain showed higher polarization, lower rates of ROS production, larger mitochondrial networks, greater cytoplasmic fractions of mitochondria and larger mitochondrial perimeters than those cultured at higher oxygen levels. Although neurons cultured in either physiological oxygen or atmospheric oxygen exhibit significant increases in mitochondrial reactive oxygen species (ROS) production when treated with the human immunodeficiency virus (HIV) virotoxin trans-activator of transcription, mitochondria of neurons cultured at physiological oxygen underwent depolarization with dramatically increased cell death, whereas those cultured at atmospheric oxygen became hyperpolarized with no increase in cell death. Studies with a second HIV virotoxin, negative regulation factor (Nef), revealed that Nef treatment also increased mitochondrial ROS production for both the oxygen conditions, but resulted in mitochondrial depolarization and increased death only in neurons cultured in physiological oxygen. These results indicate a role for oxidative metabolism in a mechanism of neurotoxicity during HIV infection and demonstrate the importance of choosing the correct, physiological, culture oxygen in mitochondrial studies performed in neurons.
Proteomics Indicators of the Rapidly Shifting Physiology from Whole Mountain Pine Beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae), Adults during Early Host Colonization

PubMed Central

Pitt, Caitlin; Robert, Jeanne A.; Bonnett, Tiffany R.; Keeling, Christopher I.; Bohlmann, Jörg; Huber, Dezene P. W.

2014-01-01

We developed proteome profiles for host colonizing mountain pine beetle adults, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae). Adult insects were fed in pairs on fresh host lodgepole pine, Pinus contorta Dougl. ex Loud, phloem tissue. The proteomes of fed individuals were monitored using iTRAQ and compared to those of starved beetles, revealing 757 and 739 expressed proteins in females and males, respectively, for which quantitative information was obtained. Overall functional category distributions were similar for males and females, with the majority of proteins falling under carbohydrate metabolism (glycolysis, gluconeogenesis, citric acid cycle), structure (cuticle, muscle, cytoskeleton), and protein and amino acid metabolism. Females had 23 proteins with levels that changed significantly with feeding (p<0.05, FDR<0.20), including chaperones and enzymes required for vitellogenesis. In males, levels of 29 proteins changed significantly with feeding (p<0.05, FDR<0.20), including chaperones as well as motor proteins. Only two proteins, both chaperones, exhibited a significant change in both females and males with feeding. Proteins with differential accumulation patterns in females exhibited higher fold changes with feeding than did those in males. This difference may be due to major and rapid physiological changes occurring in females upon finding a host tree during the physiological shift from dispersal to reproduction. The significant accumulation of chaperone proteins, a cytochrome P450, and a glutathione S-transferase, indicate secondary metabolite-induced stress physiology related to chemical detoxification during early host colonization. The females' activation of vitellogenin only after encountering a host indicates deliberate partitioning of resources and a balancing of the needs of dispersal and reproduction. PMID:25360753
Proteomics indicators of the rapidly shifting physiology from whole mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Curculionidae), adults during early host colonization.

PubMed

Pitt, Caitlin; Robert, Jeanne A; Bonnett, Tiffany R; Keeling, Christopher I; Bohlmann, Jörg; Huber, Dezene P W

2014-01-01

We developed proteome profiles for host colonizing mountain pine beetle adults, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae). Adult insects were fed in pairs on fresh host lodgepole pine, Pinus contorta Dougl. ex Loud, phloem tissue. The proteomes of fed individuals were monitored using iTRAQ and compared to those of starved beetles, revealing 757 and 739 expressed proteins in females and males, respectively, for which quantitative information was obtained. Overall functional category distributions were similar for males and females, with the majority of proteins falling under carbohydrate metabolism (glycolysis, gluconeogenesis, citric acid cycle), structure (cuticle, muscle, cytoskeleton), and protein and amino acid metabolism. Females had 23 proteins with levels that changed significantly with feeding (p<0.05, FDR<0.20), including chaperones and enzymes required for vitellogenesis. In males, levels of 29 proteins changed significantly with feeding (p<0.05, FDR<0.20), including chaperones as well as motor proteins. Only two proteins, both chaperones, exhibited a significant change in both females and males with feeding. Proteins with differential accumulation patterns in females exhibited higher fold changes with feeding than did those in males. This difference may be due to major and rapid physiological changes occurring in females upon finding a host tree during the physiological shift from dispersal to reproduction. The significant accumulation of chaperone proteins, a cytochrome P450, and a glutathione S-transferase, indicate secondary metabolite-induced stress physiology related to chemical detoxification during early host colonization. The females' activation of vitellogenin only after encountering a host indicates deliberate partitioning of resources and a balancing of the needs of dispersal and reproduction.
Structure-function relations in physiology education: Where's the mechanism?

PubMed

Lira, Matthew E; Gardner, Stephanie M

2017-06-01

Physiology demands systems thinking: reasoning within and between levels of biological organization and across different organ systems. Many physiological mechanisms explain how structures and their properties interact at one level of organization to produce emergent functions at a higher level of organization. Current physiology principles, such as structure-function relations, selectively neglect mechanisms by not mentioning this term explicitly. We explored how students characterized mechanisms and functions to shed light on how students make sense of these terms. Students characterized mechanisms as 1 ) processes that occur at levels of organization lower than that of functions; and 2 ) as detailed events with many steps involved. We also found that students produced more variability in how they characterized functions compared with mechanisms: students characterized functions in relation to multiple levels of organization and multiple definitions. We interpret these results as evidence that students see mechanisms as holding a more narrow definition than used in the biological sciences, and that students struggle to coordinate and distinguish mechanisms from functions due to cognitive processes germane to learning in many domains. We offer the instructional suggestion that we scaffold student learning by affording students opportunities to relate and also distinguish between these terms so central to understanding physiology. Copyright © 2017 the American Physiological Society.
An Active Learning Exercise to Facilitate Understanding of Nephron Function: Anatomy and Physiology of Renal Transporters

ERIC Educational Resources Information Center

Dirks-Naylor, Amie J.

2016-01-01

Renal transport is a central mechanism underlying electrolyte homeostasis, acid base balance and other essential functions of the kidneys in human physiology. Thus, knowledge of the anatomy and physiology of the nephron is essential for the understanding of kidney function in health and disease. However, students find this content difficult to…
Identification of a Novel C-Terminal Truncated WT1 Isoform with Antagonistic Effects against Major WT1 Isoforms

PubMed Central

Tatsumi, Naoya; Hojo, Nozomi; Sakamoto, Hiroyuki; Inaba, Rena; Moriguchi, Nahoko; Matsuno, Keiko; Fukuda, Mari; Matsumura, Akihide; Hayashi, Seiji; Morimoto, Soyoko; Nakata, Jun; Fujiki, Fumihiro; Nishida, Sumiyuki; Nakajima, Hiroko; Tsuboi, Akihiro; Oka, Yoshihiro; Hosen, Naoki; Sugiyama, Haruo; Oji, Yusuke

2015-01-01

The Wilms’ tumor gene WT1 consists of 10 exons and encodes a zinc finger transcription factor. There are four major WT1 isoforms resulting from alternative splicing at two sites, exon 5 (17AA) and exon 9 (KTS). All major WT1 isoforms are overexpressed in leukemia and solid tumors and play oncogenic roles such as inhibition of apoptosis, and promotion of cell proliferation, migration and invasion. In the present study, a novel alternatively spliced WT1 isoform that had an extended exon 4 (designated as exon 4a) with an additional 153 bp (designated as 4a sequence) at the 3’ end was identified and designated as an Ex4a(+)WT1 isoform. The insertion of exon 4a resulted in the introduction of premature translational stop codons in the reading frame in exon 4a and production of C-terminal truncated WT1 proteins lacking zinc finger DNA-binding domain. Overexpression of the truncated Ex4a(+)WT1 isoform inhibited the major WT1-mediated transcriptional activation of anti-apoptotic Bcl-xL gene promoter and induced mitochondrial damage and apoptosis. Conversely, suppression of the Ex4a(+)WT1 isoform by Ex4a-specific siRNA attenuated apoptosis. These results indicated that the Ex4a(+)WT1 isoform exerted dominant negative effects on anti-apoptotic function of major WT1 isoforms. Ex4a(+)WT1 isoform was endogenously expressed as a minor isoform in myeloid leukemia and solid tumor cells and increased regardless of decrease in major WT1 isoforms during apoptosis, suggesting the dominant negative effects on anti-apoptotic function of major WT1 isoforms. These results indicated that Ex4a(+)WT1 isoform had an important physiological function that regulated oncogenic function of major WT1 isoforms. PMID:26090994
Psychrophiles

NASA Astrophysics Data System (ADS)

Siddiqui, Khawar S.; Williams, Timothy J.; Wilkins, David; Yau, Sheree; Allen, Michelle A.; Brown, Mark V.; Lauro, Federico M.; Cavicchioli, Ricardo

2013-05-01

Psychrophilic (cold-adapted) microorganisms make a major contribution to Earth's biomass and perform critical roles in global biogeochemical cycles. The vast extent and environmental diversity of Earth's cold biosphere has selected for equally diverse microbial assemblages that can include archaea, bacteria, eucarya, and viruses. Underpinning the important ecological roles of psychrophiles are exquisite mechanisms of physiological adaptation. Evolution has also selected for cold-active traits at the level of molecular adaptation, and enzymes from psychrophiles are characterized by specific structural, functional, and stability properties. These characteristics of enzymes from psychrophiles not only manifest in efficient low-temperature activity, but also result in a flexible protein structure that enables biocatalysis in nonaqueous solvents. In this review, we examine the ecology of Antarctic psychrophiles, physiological adaptation of psychrophiles, and properties of cold-adapted proteins, and we provide a view of how these characteristics inform studies of astrobiology.
Characterizing the Interaction between tartrazine and two serum albumins by a hybrid spectroscopic approach.

PubMed

Pan, Xingren; Qin, Pengfei; Liu, Rutao; Wang, Jing

2011-06-22

Tartrazine is an artificial azo dye commonly used in food products. The present study evaluated the interaction of tartrazine with two serum albumins (SAs), human serum albumin (HSA) and bovine serum albumin (BSA), under physiological conditions by means of fluorescence, three-dimensional fluorescence, UV-vis absorption, and circular dichroism (CD) techniques. The fluorescence data showed that tartrazine could bind to the two SAs to form a complex. The binding process was a spontaneous molecular interaction procedure, in which van der Waals and hydrogen bond interactions played a major role. Additionally, as shown by the UV-vis absorption, three-dimensional fluorescence, and CD results, tartrazine could lead to conformational and some microenvironmental changes of both SAs, which may affect the physiological functions of SAs. The work provides important insight into the mechanism of toxicity of tartrazine in vivo.
Mammalian lipoxygenases and their biological relevance.

PubMed

Kuhn, Hartmut; Banthiya, Swathi; van Leyen, Klaus

2015-04-01

Lipoxygenases (LOXs) form a heterogeneous class of lipid peroxidizing enzymes, which have been implicated not only in cell proliferation and differentiation but also in the pathogenesis of various diseases with major public health relevance. As other fatty acid dioxygenases LOXs oxidize polyunsaturated fatty acids to their corresponding hydroperoxy derivatives, which are further transformed to bioactive lipid mediators (eicosanoids and related substances). On the other hand, lipoxygenases are key players in the regulation of the cellular redox homeostasis, which is an important element in gene expression regulation. Although the first mammalian lipoxygenases were discovered 40 years ago and although the enzymes have been well characterized with respect to their structural and functional properties the biological roles of the different lipoxygenase isoforms are not completely understood. This review is aimed at summarizing the current knowledge on the physiological roles of different mammalian LOX-isoforms and their patho-physiological function in inflammatory, metabolic, hyperproliferative, neurodegenerative and infectious disorders. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance". Copyright © 2014 Elsevier B.V. All rights reserved.
FTLD/ALS-linked TDP-43 mutations do not alter TDP-43's ability to self-regulate its expression in Drosophila.

PubMed

Miguel, Laetitia; Avequin, Tracey; Pons, Marine; Frébourg, Thierry; Campion, Dominique; Lecourtois, Magalie

2018-05-17

TDP-43 is a major disease-causing protein in amyotrophic lateral sclerosis (ALS) and Frontotemporal Lobar Degeneration (FTLD). Today, more than 50 missense mutations in the TARDBP/TDP-43 gene have been described in patients with FTLD/ALS. However, the functional consequences of FTLD/ALS-linked TDP-43 mutations are not fully elucidated. In the physiological state, TDP-43 expression is tightly regulated through an autoregulatory negative feedback loop. Maintaining normal TDP-43 protein levels is critical for proper physiological functions of the cells. In the present study, we investigated whether the FTLD/ALS-associated mutations could interfere with TDP-43 protein's capacity to modulate its own protein levels using Drosophila as an experimental model. Our data show that FTLD/ALS-associated mutant proteins regulate TDP-43 production with the same efficiency as the wild-type form of the protein. Thus, FTLD/ALS-linked TDP-43 mutations do not alter TDP-43's ability to self-regulate its expression and consequently of the homeostasis of TDP-43 protein levels. Copyright © 2018. Published by Elsevier B.V.
Evidence for biochemical and physiological differences between enzyme genotypes in Drosophila melanogaster.

PubMed Central

Cavener, D R; Clegg, M T

1981-01-01

The in vivo flux of carbon through the pentose shunt is investigated as a function of different 6-phosphogluconate dehydrogenase (6Pgd) and glucose-6-phosphate dehydrogenase (G6pd) genotypes by using differential radioactive labeling of the C-1 and C-6 positions of glucose. Alternative 6Pgd-G6pd genotypes are shown to differ in relative in vivo carbon flux through the pentose shunt. The relative in vitro specific activity differences between the 6PgdSS and 6PgdFF genotypes appear to be primarily responsible for these differences. In addition, the pentose-shunt activity is correlated with the rate of lipid synthesis. This correlation is consistent with the major metabolic function of the pathway, which is to produce NADPH for lipid synthesis. Taken together, the results of these experiments show that different genotypes of 6Pgd are associated with measurable biochemical and physiological differences. Higher order phenotypic differences of this kind must be demonstrated to support the hypothesis that natural selection can discriminate among allozymes of a given genetic locus. PMID:6794031
Stretch-activated TRPV2 channels: Role in mediating cardiopathies.

PubMed

Aguettaz, Elizabeth; Bois, Patrick; Cognard, Christian; Sebille, Stéphane

2017-11-01

Transient receptor potential vanilloid type 2, TRPV2, is a calcium-permeable cation channel belonging to the TRPV channel family. Although this channel has been first characterized as a noxious heat sensor, its mechanosensor property recently gained importance in various physiological functions. TRPV2 has been described as a stretch-mediated channel and a regulator of calcium homeostasis in several cell types and has been shown to be involved in the stretch-dependent responses in cardiomyocytes. Hence, several studies in the last years support the idea that TRPV2 play a key role in the function and structure of the heart, being involved in the cardiac compensatory mechanisms in response to pathologic or exercise-induced stress. We present here an overview of the current literature and concepts of TRPV2 channels involvement (i) in the mechanical coupling mechanisms in heart and (ii) in the mechanisms that lead to cardiomyopathies. All these studies lead us to think that TRPV2 may also be an important cardiac drug target based on its major physiological roles in heart. Copyright © 2017 Elsevier Ltd. All rights reserved.
ON THE BIOMECHANICS OF HEART VALVE FUNCTION

PubMed Central

Sacks, Michael S.; Merryman, W. David; Schmidt, David E.

2009-01-01

Heart valves (HVs) are fluidic control components of the heart that ensure unidirectional blood flow during the cardiac cycle. However, this description does not adequately describe the biomechanical ramifications of their function in that their mechanics are multi-modal. Moreover, they must replicate their cyclic function over an entire lifetime, with an estimated total functional demand of least 3×109 cycles. The focus of the present review is on the functional biomechanics of heart valves. Thus, the focus of the present review is on functional biomechanics, referring primarily to biosolid as well as several key biofluid mechanical aspects underlying heart valve physiological function. Specifically, we refer to the mechanical behaviors of the extra-cellular matrix structural proteins, underlying cellular function, and their integrated relation to the major aspects of valvular hemodynamic function. While we focus on the work from the author’s laboratories, relevant works of other investigators have been included whenever appropriate. We conclude with a summary of important future trends. PMID:19540499
Role of pigment epithelium-derived factor in the reproductive system.

PubMed

Chuderland, Dana; Ben-Ami, Ido; Bar-Joseph, Hadas; Shalgi, Ruth

2014-10-01

The physiological function of the female reproductive organs is hormonally controlled. In each cycle, the reproductive organs undergo tissue modifications that are accompanied by formation and destruction of blood vessels. Proper angiogenesis requires an accurate balance between stimulatory and inhibitory signals, provided by pro- and anti-angiogenic factors. As with many other tissues, vascular endothelial growth factor (VEGF) appears to be one of the major pro-angiogenic factors in the female reproductive organs. Pigment epithelium-derived factor (PEDF) is a non-inhibitory member of the serine protease inhibitors (serpin) superfamily, possessing potent physiologic anti-angiogenic activity that negates VEGF activity. The role of PEDF in decreasing abnormal neovascularization by exerting its anti-angiogenic effect that inhibits pro-angiogenic factors, including VEGF, has been investigated mainly in the eye and in cancer. This review summarizes the function of PEDF in the reproductive system, showing its hormonal regulation and its anti-angiogenic activity. Furthermore, some pathologies of the female reproductive organs, including endometriosis, ovarian hyperstimulation syndrome, polycystic ovary syndrome, and others, are associated with a faulty angiogenic process. This review illuminates the role of PEDF in their pathogenesis and treatment. Collectively, we can conclude that although PEDF seems to play an essential role in the physiology and pathophysiology of the reproductive system, its full role and mechanism of action still need to be elucidated. © 2014 Society for Reproduction and Fertility.

Melatonin: Pharmacology, Functions and Therapeutic Benefits

PubMed Central

Tordjman, Sylvie; Chokron, Sylvie; Delorme, Richard; Charrier, Annaëlle; Bellissant, Eric; Jaafari, Nemat; Fougerou, Claire

2017-01-01

Abstract: Background: Melatonin synchronizes central but also peripheral oscillators (fetal adrenal gland, pancreas, liver, kidney, heart, lung, fat, gut, etc.), allowing temporal organization of biological functions through circadian rhythms (24-hour cycles) in relation to periodic environmental changes and therefore adaptation of the individual to his/her internal and external environment. Measures of melatonin are considered the best peripheral indices of human circadian timing based on an internal 24-hour clock. Methods: First, the pharmacology of melatonin (biosynthesis and circadian rhythms, pharmacokinetics and mechanisms of action) is described, allowing a better understanding of the short and long term effects of melatonin following its immediate or prolonged release. Then, research related to the physiological effects of melatonin is reviewed. Results: The physiological effects of melatonin are various and include detoxification of free radicals and antioxidant actions, bone formation and protection, reproduction, and cardiovascular, immune or body mass regulation. Also, protective and therapeutic effects of melatonin are reported, especially with regard to brain or gastrointestinal protection, psychiatric disorders, cardiovascular diseases and oncostatic effects. Conclusion: This review highlights the high number and diversity of major melatonin effects and opens important perspectives for measuring melatonin as a biomarker (biomarker of early identification of certain disorders and also biomarker of their follow-up) and using melatonin with clinical preventive and therapeutic applications in newborns, children and adults based on its physiological regulatory effects. PMID:28503116
Physiologic Dysfunction Scores and Cognitive Function Test Performance in United States Adults

PubMed Central

Kobrosly, Roni W; Seplaki, Christopher L; Jones, Courtney M; van Wijngaarden, Edwin

2013-01-01

Objective To investigate the relationship between a measure of cumulative physiologic dysfunction and specific domains of cognitive function. Methods We examined a summary score measuring physiological dysfunction, a multisystem measure of the body’s ability to effectively adapt to physical and psychological demands, in relation to cognitive function deficits in a population of 4511 adults aged 20 to 59 who participated in the third National Health and Nutrition Examination Survey (1988–1994). Measures of cognitive function comprised three domains: working memory, visuomotor speed, and perceptual-motor speed. ‘Physiologic dysfunction’ scores summarizing measures of cardiovascular, immunologic, kidney, and liver function were explored. We used multiple linear regression models to estimate associations between cognitive function measures and physiological dysfunction scores, adjusting for socioeconomic factors, test conditions, and self-reported health factors. Results We noted a dose-response relationship between physiologic dysfunction and working memory (coefficient = 0.207, 95% CI = (0.066, 0.348), p < 0.0001) that persisted after adjustment for all covariates (p = 0.03). We did not observe any significant relationships between dysfunction scores and visuomotor (p = 0.37) or perceptual-motor ability (p = 0.33). Conclusions Our findings suggest that multisystem physiologic dysfunction is associated with working memory. Future longitudinal studies are needed to clarify the underlying mechanisms and explore the persistency of this association into later life. We suggest that such studies should incorporate physiologic data, neuroendocrine parameters, and a wide range of specific cognitive domains. PMID:22155941
Reduced mitochondrial mass and function add to age-related susceptibility toward diet-induced fatty liver in C57BL/6J mice.

PubMed

Lohr, Kerstin; Pachl, Fiona; Moghaddas Gholami, Amin; Geillinger, Kerstin E; Daniel, Hannelore; Kuster, Bernhard; Klingenspor, Martin

2016-10-01

Nonalcoholic fatty liver disease (NAFLD) is a major health burden in the aging society with an urging medical need for a better understanding of the underlying mechanisms. Mitochondrial fatty acid oxidation and mitochondrial-derived reactive oxygen species (ROS) are considered critical in the development of hepatic steatosis, the hallmark of NAFLD. Our study addressed in C57BL/6J mice the effect of high fat diet feeding and age on liver mitochondria at an early stage of NAFLD development. We therefore analyzed functional characteristics of hepatic mitochondria and associated alterations in the mitochondrial proteome in response to high fat feeding in adolescent, young adult, and middle-aged mice. Susceptibility to diet-induced obesity increased with age. Young adult and middle-aged mice developed fatty liver, but not adolescent mice. Fat accumulation was negatively correlated with an age-related reduction in mitochondrial mass and aggravated by a reduced capacity of fatty acid oxidation in high fat-fed mice. Irrespective of age, high fat diet increased ROS production in hepatic mitochondria associated with a balanced nuclear factor erythroid-derived 2 like 2 (NFE2L2) dependent antioxidative response, most likely triggered by reduced tethering of NFE2L2 to mitochondrial phosphoglycerate mutase 5. Age indirectly influenced mitochondrial function by reducing mitochondrial mass, thus exacerbating diet-induced fat accumulation. Therefore, consideration of age in metabolic studies must be emphasized. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.
Regulation, Signaling, and Physiological Functions of G-Proteins.

PubMed

Syrovatkina, Viktoriya; Alegre, Kamela O; Dey, Raja; Huang, Xin-Yun

2016-09-25

Heterotrimeric guanine-nucleotide-binding regulatory proteins (G-proteins) mainly relay the information from G-protein-coupled receptors (GPCRs) on the plasma membrane to the inside of cells to regulate various biochemical functions. Depending on the targeted cell types, tissues, and organs, these signals modulate diverse physiological functions. The basic schemes of heterotrimeric G-proteins have been outlined. In this review, we briefly summarize what is known about the regulation, signaling, and physiological functions of G-proteins. We then focus on a few less explored areas such as the regulation of G-proteins by non-GPCRs and the physiological functions of G-proteins that cannot be easily explained by the known G-protein signaling pathways. There are new signaling pathways and physiological functions for G-proteins to be discovered and further interrogated. With the advancements in structural and computational biological techniques, we are closer to having a better understanding of how G-proteins are regulated and of the specificity of G-protein interactions with their regulators. Copyright © 2016 Elsevier Ltd. All rights reserved.
Functional Groups Based on Leaf Physiology: Are they Spatially and Temporally Robust?

NASA Technical Reports Server (NTRS)

Foster, Tammy E.; Brooks, J. Renee

2004-01-01

The functional grouping hypothesis, which suggests that complexity in ecosystem function can be simplified by grouping species with similar responses, was tested in the Florida scrub habitat. Functional groups were identified based on how species in fire maintained Florida scrub regulate exchange of carbon and water with the atmosphere as indicated by both instantaneous gas exchange measurements and integrated measures of function (%N, delta C-13, delta N-15, C-N ratio). Using cluster analysis, five distinct physiologically-based functional groups were identified in the fire maintained scrub. These functional groups were tested to determine if they were robust spatially, temporally, and with management regime. Analysis of Similarities (ANOSIM), a non-parametric multivariate analysis, indicated that these five physiologically-based groupings were not altered by plot differences (R = -0.115, p = 0.893) or by the three different management regimes; prescribed burn, mechanically treated and burn, and fire-suppressed (R = 0.018, p = 0.349). The physiological groupings also remained robust between the two climatically different years 1999 and 2000 (R = -0.027, p = 0.725). Easy-to-measure morphological characteristics indicating functional groups would be more practical for scaling and modeling ecosystem processes than detailed gas-exchange measurements, therefore we tested a variety of morphological characteristics as functional indicators. A combination of non-parametric multivariate techniques (Hierarchical cluster analysis, non-metric Multi-Dimensional Scaling, and ANOSIM) were used to compare the ability of life form, leaf thickness, and specific leaf area classifications to identify the physiologically-based functional groups. Life form classifications (ANOSIM; R = 0.629, p 0.001) were able to depict the physiological groupings more adequately than either specific leaf area (ANOSIM; R = 0.426, p = 0.001) or leaf thickness (ANOSIM; R 0.344, p 0.001). The ability of life forms to depict the physiological groupings was improved by separating the parasitic Ximenia americana from the shrub category (ANOSIM; R = 0.794, p = 0.001). Therefore, a life form classification including parasites was determined to be a good indicator of the physiological processes of scrub species, and would be a useful method of grouping for scaling physiological processes to the ecosystem level.
TEMPORAL NEUROTRANSMITTER CONDITIONING RESTORES THE FUNCTIONAL ACTIVITY OF ADULT SPINAL-CORD NEURONS IN LONG-TERM CULTURE

PubMed Central

Das, Mainak; Bhargava, Neelima; Bhalkikar, Abhijeet; Kang, Jung Fong; Hickman, James J

2008-01-01

The ability to culture functional adult mammalian spinal-cord neurons represents an important step in the understanding and treatment of a spectrum of neurological disorders including spinal cord injury. Previously, the limited functional recovery of these cells, as characterized by a diminished ability to initiate action potentials and to exhibit repetitive firing patterns, has arisen as a major impediment to their physiological relevance. In this report we demonstrate that single temporal doses of the neurotransmitters serotonin, glutamate (N-acetyl-DL-glutamic acid) and acetylcholine-chloride leads to the full electrophysiological functional recovery of adult mammalian spinal-cord neurons, when they are cultured under defined serum-free conditions. Approximately 60% of the neurons treated regained their electrophysiological signature, often firing single, double and, most importantly, multiple action potentials. PMID:18005959
Listening to music and physiological and psychological functioning: the mediating role of emotion regulation and stress reactivity.

PubMed

Thoma, M V; Scholz, U; Ehlert, U; Nater, U M

2012-01-01

Music listening has been suggested to have short-term beneficial effects. The aim of this study was to investigate the association and potential mediating mechanisms between various aspects of habitual music-listening behaviour and physiological and psychological functioning. An internet-based survey was conducted in university students, measuring habitual music-listening behaviour, emotion regulation, stress reactivity, as well as physiological and psychological functioning. A total of 1230 individuals (mean = 24.89 ± 5.34 years, 55.3% women) completed the questionnaire. Quantitative aspects of habitual music-listening behaviour, i.e. average duration of music listening and subjective relevance of music, were not associated with physiological and psychological functioning. In contrast, qualitative aspects, i.e. reasons for listening (especially 'reducing loneliness and aggression', and 'arousing or intensifying specific emotions') were significantly related to physiological and psychological functioning (all p = 0.001). These direct effects were mediated by distress-augmenting emotion regulation and individual stress reactivity. The habitual music-listening behaviour appears to be a multifaceted behaviour that is further influenced by dispositions that are usually not related to music listening. Consequently, habitual music-listening behaviour is not obviously linked to physiological and psychological functioning.
Functional Groups Based on Leaf Physiology: Are they Spatially and Temporally Robust?

NASA Technical Reports Server (NTRS)

Foster, Tammy E.; Brooks, J. Renee; Quincy, Charles (Technical Monitor)

2002-01-01

The functional grouping hypothesis, which suggests that complexity in function can be simplified by grouping species with similar responses, was tested in the Florida scrub habitat. Functional groups were identified based on how species in fire maintained FL scrub function in terms of carbon, water and nitrogen dynamics. The suite of physiologic parameters measured to determine function included both instantaneous gas exchange measurements obtained from photosynthetic light response curves and integrated measures of function. Using cluster analysis, five distinct physiologically-based functional groups were identified. Using non-parametric multivariate analyses, it was determined that these five groupings were not altered by plot differences or by the three different management regimes; prescribed burn, mechanically treated and burn, and fire-suppressed. The physiological groupings also remained robust between the two years 1999 and 2000. In order for these groupings to be of use for scaling ecosystem processes, there needs to be an easy-to-measure morphological indicator of function. Life form classifications were able to depict the physiological groupings more adequately than either specific leaf area or leaf thickness. THe ability of life forms to depict the groupings was improved by separating the parasitic Ximenia americana from the shrub category.
Functionality of empirical model-based predictive analytics for the early detection of hemodynamic instabilty.

PubMed

Summers, Richard L; Pipke, Matt; Wegerich, Stephan; Conkright, Gary; Isom, Kristen C

2014-01-01

Background. Monitoring cardiovascular hemodynamics in the modern clinical setting is a major challenge. Increasing amounts of physiologic data must be analyzed and interpreted in the context of the individual patients pathology and inherent biologic variability. Certain data-driven analytical methods are currently being explored for smart monitoring of data streams from patients as a first tier automated detection system for clinical deterioration. As a prelude to human clinical trials, an empirical multivariate machine learning method called Similarity-Based Modeling (SBM), was tested in an In Silico experiment using data generated with the aid of a detailed computer simulator of human physiology (Quantitative Circulatory Physiology or QCP) which contains complex control systems with realistic integrated feedback loops. Methods. SBM is a kernel-based, multivariate machine learning method that that uses monitored clinical information to generate an empirical model of a patients physiologic state. This platform allows for the use of predictive analytic techniques to identify early changes in a patients condition that are indicative of a state of deterioration or instability. The integrity of the technique was tested through an In Silico experiment using QCP in which the output of computer simulations of a slowly evolving cardiac tamponade resulted in progressive state of cardiovascular decompensation. Simulator outputs for the variables under consideration were generated at a 2-min data rate (0.083Hz) with the tamponade introduced at a point 420 minutes into the simulation sequence. The functionality of the SBM predictive analytics methodology to identify clinical deterioration was compared to the thresholds used by conventional monitoring methods. Results. The SBM modeling method was found to closely track the normal physiologic variation as simulated by QCP. With the slow development of the tamponade, the SBM model are seen to disagree while the simulated biosignals in the early stages of physiologic deterioration and while the variables are still within normal ranges. Thus, the SBM system was found to identify pathophysiologic conditions in a timeframe that would not have been detected in a usual clinical monitoring scenario. Conclusion. In this study the functionality of a multivariate machine learning predictive methodology that that incorporates commonly monitored clinical information was tested using a computer model of human physiology. SBM and predictive analytics were able to differentiate a state of decompensation while the monitored variables were still within normal clinical ranges. This finding suggests that the SBM could provide for early identification of a clinical deterioration using predictive analytic techniques. predictive analytics, hemodynamic, monitoring.
[Diastolic dysfunction in the elderly subjects. Disease or a physiological manifestation of ageing?].

PubMed

Meluzín, J; Podroužková, H; Gregorová, Z; Panovský, R

2013-05-01

The purpose of this summary paper is to discuss the current knowledge of the impact of age on diastolic function of the left ventricle. Data from the literature: Reports published till this time have convincingly demonstrated a significant relationship of age to diastolic function of the left ventricle. Ageing is a physiological process accompanied by structural changes in both myocardium and arterial bed resulting in worsening of parameters characterizing the left ventricular diastolic function. This "physiological" diastolic dysfunction in the elderly subjects can be explained by the deterioration of passive left ventricular filling properties and by worsening of left ventricular relaxation. The detailed analysis of published reports shows problems in distiguishing this "physiological" diastolic dysfunction resulting from physiological tissue ageing from "pathological" diastolic dysfunction reflecting a disease of cardiovascular system. To interprete correctly values of parameters quantifying diastolic function of the left ventricle, one should take into account the age of subjects under the examination. Further studies are necessary to distinguish exactly "physiological" deterioration of diastolic function associated with ageing from really "pathological" diastolic dysfunction in the elderly subjects.
Wash or wipe? A comparative study of skin physiological changes between water washing and wiping after skin cleaning.

PubMed

Ogai, K; Matsumoto, M; Aoki, M; Ota, R; Hashimoto, K; Wada, R; Kobayashi, M; Sugama, J

2017-11-01

Presently, skin-cleaning agents that claim to be removed by water or wiping alone are commercially available and have been used for the purpose of bed baths. However, there is a lack of knowledge on how water washing and wiping differently affect skin physiological functions or ceramide content. The aim of this study was to compare the effects of water washing and wiping on skin physiological functions and ceramide content. Three kinds of the cleaning agents with different removal techniques (ie, water washing and wiping) were used in this study. Skin physiological functions (ie, transepidermal water loss, skin hydration, and skin pH) and skin ceramide content were measured before and after seven consecutive days of the application of each cleaning agent. No significant differences in skin physiological functions or ceramide content were observed between water washing and wiping. Cleaning agents that claim to be removed by water washing or wiping do not affect skin physiological functions or ceramide content by either removal method. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Genetic ablation of P65 subunit of NF-κB in mdx mice to improve muscle physiological function.

PubMed

Yin, Xi; Tang, Ying; Li, Jian; Dzuricky, Anna T; Pu, Chuanqiang; Fu, Freddie; Wang, Bing

2017-10-01

Duchenne muscular dystrophy (DMD) is a genetic muscle disease characterized by dystrophin deficiency. Beyond gene replacement, the question of whether ablation of the p65 gene of nuclear factor-kappa B (NF-κB) in DMD can improve muscle physiology function is unknown. In this study, we investigated muscle physiological improvement in mdx mice (DMD model) with a genetic reduction of NF-κB. Muscle physiological function and histology were studied in 2-month-old mdx/p65 +/- , wild-type, mdx, and human minidystrophin gene transgenic mdx (TghΔDys/mdx) mice. Improved muscle physiological function was found in mdx/p65 +/- mice when compared with mdx mice; however, it was similar to TghΔDys/mdx mice. The results indicate that genetic reduction of p65 levels diminished chronic inflammation in dystrophic muscle, thus leading to amelioration of muscle pathology and improved muscle physiological function. The results show that inhibition of NF-κB may be a promising therapy when combined with gene therapy for DMD. Muscle Nerve 56: 759-767, 2017. © 2016 Wiley Periodicals, Inc.
The Unexpected and Exceptionally Facile Chemical Modification of the Phenolic Hydroxyl Group of Tyrosine by Polyhalogenated Quinones under Physiological Conditions.

PubMed

Qu, Na; Li, Feng; Shao, Bo; Shao, Jie; Zhai, Guijin; Wang, Fuyi; Zhu, Ben-Zhan

2016-10-17

The phenolic hydroxyl group of tyrosine residue plays a crucial role in the structure and function of many proteins. However, little study has been reported about its modification by chemical agents under physiological conditions. In this study, we found, unexpectedly, that the phenolic hydroxyl group of tyrosine can be rapidly and efficiently modified by tetrafluoro-1,4-benzoquinone and other polyhalogenated quinones, which are the major genotoxic and carcinogenic quinoid metabolites of polyhalogenated aromatic compounds. The modification was found to be mainly due to the formation of a variety of fluoroquinone-O-tyrosine conjugates and their hydroxylated derivatives via nucleophilic substitution pathway. Analogous modifications were observed for tyrosine-containing peptides. Further studies showed that the blockade of the reactive phenolic hydroxyl group of tyrosine in the substrate peptide, even by very low concentration of tetrafluoro-1,4-benzoquinone, can prevent the kinase catalyzed tyrosine phosphorylation. This is the first report showing the exceptionally facile chemical modification of the phenolic hydroxyl group of tyrosine by polyhalogenated quinones under normal physiological conditions, which may have potential biological and toxicological implications.
Expression of Ambra1 in mouse brain during physiological and Alzheimer type aging.

PubMed

Sepe, Sara; Nardacci, Roberta; Fanelli, Francesca; Rosso, Pamela; Bernardi, Cinzia; Cecconi, Francesco; Mastroberardino, Pier G; Piacentini, Mauro; Moreno, Sandra

2014-01-01

Autophagy is a major protein degradation pathway, essential for stress-induced and constitutive protein turnover. In nervous tissue, autophagy is constitutively active and crucial to neuronal survival. The efficiency of the autophagic pathway reportedly undergoes age-related decline, and autophagy defects are observed in neurodegenerative diseases. Since Ambra1 plays a fundamental role in regulating the autophagic process in developing nervous tissue, we investigated the expression of this protein in mature mouse brain and during physiological and Alzheimer type aging. The present study accomplished the first complete map of Ambra1 protein distribution in the various brain areas, and highlights differential expression in neuronal/glial cell populations. Differences in Ambra1 content are possibly related to specific neuronal features and properties, particularly concerning susceptibility to neurodegeneration. Furthermore, the analysis of Ambra1 expression in physiological and pathological brain aging supports important, though conflicting, functions of autophagy in neurodegenerative processes. Thus, novel therapeutic approaches, based on autophagy modulation, should also take into account the age-dependent roles of this mechanism in establishing, promoting, or counteracting neurodegeneration. Copyright © 2014 Elsevier Inc. All rights reserved.
Unperturbed vs. post-transplantation hematopoiesis: both in vivo but different.

PubMed

Busch, Katrin; Rodewald, Hans-Reimer

2016-07-01

Hematopoietic stem cell (HSC) transplantation has yielded tremendous information on experimental properties of HSCs. Yet, it remains unclear whether transplantation reflects the physiology of hematopoiesis. A limitation is the difficulty in accessing HSC functions without isolation, in-vitro manipulation and readout for potential. New genetic fate mapping and clonal marking techniques now shed light on hematopoiesis under physiological conditions. Transposon-based genetic marks were introduced across the entire hematopoietic system to follow the clonal dynamics of these tags over time. A polyclonal source downstream from stem cells was found responsible for the production of at least granulocytes. In independent experiments, HSCs were genetically marked in adult mice, and the kinetics of label emergence throughout the system was followed over time. These experiments uncovered that during physiological steady-state hematopoiesis large numbers of HSCs yield differentiated progeny. Individual HSCs were active only rarely, indicating their very slow periodicity of differentiation rather than quiescence. Noninvasive genetic experiments in mice have identified a major role of stem and progenitor cells downstream from HSCs as drivers of adult hematopoiesis, and revealed that post-transplantation hematopoiesis differs quantitatively from normal steady-state hematopoiesis.
Outlier-resilient complexity analysis of heartbeat dynamics

NASA Astrophysics Data System (ADS)

Lo, Men-Tzung; Chang, Yi-Chung; Lin, Chen; Young, Hsu-Wen Vincent; Lin, Yen-Hung; Ho, Yi-Lwun; Peng, Chung-Kang; Hu, Kun

2015-03-01

Complexity in physiological outputs is believed to be a hallmark of healthy physiological control. How to accurately quantify the degree of complexity in physiological signals with outliers remains a major barrier for translating this novel concept of nonlinear dynamic theory to clinical practice. Here we propose a new approach to estimate the complexity in a signal by analyzing the irregularity of the sign time series of its coarse-grained time series at different time scales. Using surrogate data, we show that the method can reliably assess the complexity in noisy data while being highly resilient to outliers. We further apply this method to the analysis of human heartbeat recordings. Without removing any outliers due to ectopic beats, the method is able to detect a degradation of cardiac control in patients with congestive heart failure and a more degradation in critically ill patients whose life continuation relies on extracorporeal membrane oxygenator (ECMO). Moreover, the derived complexity measures can predict the mortality of ECMO patients. These results indicate that the proposed method may serve as a promising tool for monitoring cardiac function of patients in clinical settings.
Visual artistic creativity and the brain.

PubMed

Heilman, Kenneth M; Acosta, Lealani Mae

2013-01-01

Creativity is the development of a new or novel understanding--insight that leads to the expression of orderly relationships (e.g., finding and revealing the thread that unites). Visual artistic creativity plays an important role in the quality of human lives, and the goal of this chapter is to describe some of the brain mechanisms that may be important in visual artistic creativity. The initial major means of learning how the brain mediates any activity is to understand the anatomy and physiology that may support these processes. A further understanding of specific cognitive activities and behaviors may be gained by studying patients who have diseases of the brain and how these diseases influence these functions. Physiological recording such as electroencephalography and brain imaging techniques such as PET and fMRI have also allowed us to gain a better understanding of the brain mechanisms important in visual creativity. In this chapter, we discuss anatomic and physiological studies, as well as neuropsychological studies of healthy artists and patients with neurological disease that have helped us gain some insight into the brain mechanisms that mediate artistic creativity. © 2013 Elsevier B.V. All rights reserved.
Physiological functions and pathobiology of TDP-43 and FUS/TLS proteins.

PubMed

Ratti, Antonia; Buratti, Emanuele

2016-08-01

The multiple roles played by RNA binding proteins in neurodegeneration have become apparent following the discovery of TAR DNA binding protein 43 kDa (TDP-43) and fused in sarcoma/translocated in liposarcoma (FUS/TLS) involvement in amyotrophic lateral sclerosis and frontotemporal lobar dementia. In these two diseases, the majority of patients display the presence of aggregated forms of one of these proteins in their brains. The study of their functional properties currently represents a very promising target for developing the effective therapeutic options that are still lacking. This aim, however, must be preceded by an accurate evaluation of TDP-43 and FUS/TLS biological functions, both in physiological and disease conditions. Recent findings have uncovered several aspects of RNA metabolism that can be affected by misregulation of these two proteins. Progress has also been made in starting to understand how the aggregation of these proteins occurs and spreads from cell to cell. The aim of this review will be to provide a general overview of TDP-43 and FUS/TLS proteins and to highlight their physiological functions. At present, the emerging picture is that TDP-43 and FUS/TLS control several aspects of an mRNA's life, but they can also participate in DNA repair processes and in non-coding RNA metabolism. Although their regulatory activities are similar, they regulate mainly distinct RNA targets and show different pathogenetic mechanisms in amyotrophic lateral sclerosis/frontotemporal lobar dementia diseases. The identification of key events in these processes represents today the best chance of finding targetable options for therapeutic approaches that might actually make a difference at the clinical level. The two major RNA Binding Proteins involved in Amyotrophic Lateral Sclerosisi and Frontotemporal Dementia are TDP-43 and FUST/TLS. Both proteins are involved in regulating all aspects of RNA and RNA life cycle within neurons, from transcription, processing, and transport/stability to the formation of cytoplasmic and nuclear stress granules. For this reason, the aberrant aggregation of these factors during disease can impair multiple RNA metabolic pathways and eventually lead to neuronal death/inactivation. The purpose of this review is to provide an up-to-date perspective on what we know about this issue at the molecular level. This article is part of the Frontotemporal Dementia special issue. © 2016 International Society for Neurochemistry.
New Perspectives on Acetate and One-Carbon Metabolism in the Methanoarchaea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferry, James

Carbonic anhydrases catalyze the reversible hydration of carbon dioxide to bicarbonate. Although widespread in prokaryotes of the domains Bacteria and Archaea, few have been investigated and the physiological functions are largely unknown. Carbonic anhydrases are of biotechnological interest for carbon dioxide capture and sequestration at point sources. Prokaryotes encode three independently evolved classes. The alpha-class is restricted to a few pathogens and the other two are uniformly distributed in phylogenetically and physiologically diverse species. Although wide-spread in prokaryotes, only three gamma-class enzymes have been biochemically characterized and the physiological functions have not been investigated. The gamma-class is prominent in anaerobicmore » acetate-utilizing methane-producing species of the genus Methanosarcina that encode three subclasses. Enzymes from two of the subclasses, Cam and CamH from Methanosarcina thermophila, have been characterized and found to utilize iron in the active site which is the first example of an iron-containing carbonic anhydrase. No representative of the third subclass has been isolated, although this subclass constitutes the great majority of the β-class. This grant application proposed to characterize gamma-class carbonic anhydrases from diverse anaerobic prokaryotes from the domains Bacteria and Archaea to broaden the understanding of this enzyme. In particular, the three subclasses present the genetically tractable acetate-utilizing methanogen Methanosarcina acetivorans will be investigated to extend studies of acetate and one-carbon metabolism in this species. A genetic approach will be taken to ascertain the physiological functions. It is also proposed to delve deeper into the mechanism of Cam from M. thermophila, the archetype of the gamma-class, via a high resolution neutron structure and kinetic analysis of site-specific amino acid replacement variants. In the course of the investigation, goals were added to take advantage of discoveries on enzymes responding to oxidative stress.« less
From functional architecture to functional connectomics.

PubMed

Reid, R Clay

2012-07-26

"Receptive Fields, Binocular Interaction and Functional Architecture in the Cat's Visual Cortex" by Hubel and Wiesel (1962) reported several important discoveries: orientation columns, the distinct structures of simple and complex receptive fields, and binocular integration. But perhaps the paper's greatest influence came from the concept of functional architecture (the complex relationship between in vivo physiology and the spatial arrangement of neurons) and several models of functionally specific connectivity. They thus identified two distinct concepts, topographic specificity and functional specificity, which together with cell-type specificity constitute the major determinants of nonrandom cortical connectivity. Orientation columns are iconic examples of topographic specificity, whereby axons within a column connect with cells of a single orientation preference. Hubel and Wiesel also saw the need for functional specificity at a finer scale in their model of thalamic inputs to simple cells, verified in the 1990s. The difficult but potentially more important question of functional specificity between cortical neurons is only now becoming tractable with new experimental techniques. Copyright © 2012 Elsevier Inc. All rights reserved.

Cardiac Physiology of Aging: Extracellular Considerations.

PubMed

Horn, Margaux A

2015-07-01

Aging is a major risk factor for the development of cardiovascular disease, with the majority of affected patients being elderly. Progressive changes to myocardial structure and function occur with aging, often in concert with underlying pathologies. However, whether chronological aging results in a remodeled "aged substrate" has yet to be established. In addition to myocyte contractility, myocardial performance relies heavily on the cardiac extracellular matrix (ECM), the roles of which are as dynamic as they are significant; including providing structural integrity, assisting in force transmission throughout the cardiac cycle and acting as a signaling medium for communication between cells and the extracellular environment. In the healthy heart, ECM homeostasis must be maintained, and matrix deposition is in balance with degradation. Consequently, alterations to, or misregulation of the cardiac ECM has been shown to occur in both aging and in pathological remodeling with disease. Mounting evidence suggests that age-induced matrix remodeling may occur at the level of ECM control; including collagen synthesis, deposition, maturation, and degradation. Furthermore, experimental studies using aged animal models not only suggest that the aged heart may respond differently to insult than the young, but the identification of key players specific to remodeling with age may hold future therapeutic potential for the treatment of cardiac dysfunction in the elderly. This review will focus on the role of the cardiac interstitium in the physiology of the aging myocardium, with particular emphasis on the implications to age-related remodeling in disease. © 2015 American Physiological Society.
S-acylation dependent post-translational cross-talk regulates large conductance calcium- and voltage- activated potassium (BK) channels

PubMed Central

Shipston, Michael J.

2014-01-01

Mechanisms that control surface expression and/or activity of large conductance calcium-activated potassium (BK) channels are important determinants of their (patho)physiological function. Indeed, BK channel dysfunction is associated with major human disorders ranging from epilepsy to hypertension and obesity. S-acylation (S-palmitoylation) represents a major reversible, post-translational modification controlling the properties and function of many proteins including ion channels. Recent evidence reveals that both pore-forming and regulatory subunits of BK channels are S-acylated and control channel trafficking and regulation by AGC-family protein kinases. The pore-forming α-subunit is S-acylated at two distinct sites within the N- and C-terminus, each site being regulated by different palmitoyl acyl transferases (zDHHCs) and acyl thioesterases (APTs). S-acylation of the N-terminus controls channel trafficking and surface expression whereas S-acylation of the C-terminal domain determines regulation of channel activity by AGC-family protein kinases. S-acylation of the regulatory β4-subunit controls ER exit and surface expression of BK channels but does not affect ion channel kinetics at the plasma membrane. Furthermore, a significant number of previously identified BK-channel interacting proteins have been shown, or are predicted to be, S-acylated. Thus, the BK channel multi-molecular signaling complex may be dynamically regulated by this fundamental post-translational modification and thus S-acylation likely represents an important determinant of BK channel physiology in health and disease. PMID:25140154
Activity-Based Profiling of a Physiologic Aglycone Library Reveals Sugar Acceptor Promiscuity of Family 1 UDP-Glucosyltransferases from Grape1[W

PubMed Central

Bönisch, Friedericke; Frotscher, Johanna; Stanitzek, Sarah; Rühl, Ernst; Wüst, Matthias; Bitz, Oliver; Schwab, Wilfried

2014-01-01

Monoterpenols serve various biological functions and accumulate in grape (Vitis vinifera), where a major fraction occurs as nonvolatile glycosides. We have screened the grape genome for sequences with similarity to terpene URIDINE DIPHOSPHATE GLYCOSYLTRANSFERASES (UGTs) from Arabidopsis (Arabidopsis thaliana). A ripening-related expression pattern was shown for three candidates by spatial and temporal expression analyses in five grape cultivars. Transcript accumulation correlated with the production of monoterpenyl β-d-glucosides in grape exocarp during ripening and was low in vegetative tissue. Targeted functional screening of the recombinant UGTs for their biological substrates was performed by activity-based metabolite profiling (ABMP) employing a physiologic library of aglycones built from glycosides isolated from grape. This approach led to the identification of two UDP-glucose:monoterpenol β-d-glucosyltransferases. Whereas VvGT14a glucosylated geraniol, R,S-citronellol, and nerol with similar efficiency, the three allelic forms VvGT15a, VvGT15b, and VvGT15c preferred geraniol over nerol. Kinetic resolution of R,S-citronellol and R,S-linalool was shown for VvGT15a and VvGT14a, respectively. ABMP revealed geraniol as the major biological substrate but also disclosed that these UGTs may add to the production of further glycoconjugates in planta. ABMP of aglycone libraries provides a versatile tool to uncover novel biologically relevant substrates of small-molecule glycosyltransferases that often show broad sugar acceptor promiscuity. PMID:25073706
High-throughput screening identifies Ceefourin 1 and Ceefourin 2 as highly selective inhibitors of multidrug resistance protein 4 (MRP4).

PubMed

Cheung, Leanna; Flemming, Claudia L; Watt, Fujiko; Masada, Nanako; Yu, Denise M T; Huynh, Tony; Conseil, Gwenaëlle; Tivnan, Amanda; Polinsky, Alexander; Gudkov, Andrei V; Munoz, Marcia A; Vishvanath, Anasuya; Cooper, Dermot M F; Henderson, Michelle J; Cole, Susan P C; Fletcher, Jamie I; Haber, Michelle; Norris, Murray D

2014-09-01

Multidrug resistance protein 4 (MRP4/ABCC4), a member of the ATP-binding cassette (ABC) transporter superfamily, is an organic anion transporter capable of effluxing a wide range of physiologically important signalling molecules and drugs. MRP4 has been proposed to contribute to numerous functions in both health and disease; however, in most cases these links remain to be unequivocally established. A major limitation to understanding the physiological and pharmacological roles of MRP4 has been the absence of specific small molecule inhibitors, with the majority of established inhibitors also targeting other ABC transporter family members, or inhibiting the production, function or degradation of important MRP4 substrates. We therefore set out to identify more selective and well tolerated inhibitors of MRP4 that might be used to study the many proposed functions of this transporter. Using high-throughput screening, we identified two chemically distinct small molecules, Ceefourin 1 and Ceefourin 2, that inhibit transport of a broad range of MRP4 substrates, yet are highly selective for MRP4 over other ABC transporters, including P-glycoprotein (P-gp), ABCG2 (Breast Cancer Resistance Protein; BCRP) and MRP1 (multidrug resistance protein 1; ABCC1). Both compounds are more potent MRP4 inhibitors in cellular assays than the most widely used inhibitor, MK-571, requiring lower concentrations to effect a comparable level of inhibition. Furthermore, Ceefourin 1 and Ceefourin 2 have low cellular toxicity, and high microsomal and acid stability. These newly identified inhibitors should be of great value for efforts to better understand the biological roles of MRP4, and may represent classes of compounds with therapeutic application. Copyright © 2014 Elsevier Inc. All rights reserved.
New advances in cell physiology and pathophysiology of the exocrine pancreas.

PubMed

Mössner, Joachim

2010-01-01

This review provides some aspects on the physiology of stimulation and inhibition of pancreatic digestive enzyme secretion and the pathophysiology of pancreatic acinar cell function leading to pancreatitis. Cholecystokinin (CCK) stimulates both directly via CCK-A receptors on acinar cells and indirectly via CCK-B receptors on nerves, followed by acetylcholine release, pancreatic enzyme secretion. It is still not known whether CCK-A receptors exist in human acinar cells, in contrast to acinar cells of rodents where CCK-A receptors have been well described. CCK has numerous actions both in the periphery and in the central nervous systems. CCK inhibits gastric motility and regulates satiety. Another major function of CCK is stimulation of gallbladder contraction. This function enables that bile acids act simultaneously with pancreatic lipolytic enzymes. Secretin is a major stimulator of bicarbonate secretion. Trypsinogen is activated by the gut mucosal enzyme enterokinase. The other pancreatic proenzymes are activated by trypsin. Termination of enzyme secretion may be regulated by negative feedback mechanisms via destruction of CCK-releasing peptides by trypsin. Furthermore, the ileum may act as a brake by release of inhibitory hormones such as PYY and somatostatin. In the pathophysiology of acute pancreatitis, fusion of zymogen granules with lysosomes leading to intracellular activation of trypsinogen is regarded as an initiation step. This activation of trypsinogen may be caused by the lysosomal enzyme cathepsin B. However, autoactivation of trypsinogen itself may be a possibility in pathogenesis. Autoactivation is enhanced in certain mutations of trypsinogen. Furthermore, an imbalance of protease inhibitors and active proteases may be involved. The role of pancreatic lipolytic enzymes, the role of bicarbonate secretion, and toxic Ca(2+) signals by excessive liberation from the endoplasmic reticulum have to be discussed in the pathogenesis of acute pancreatitis. Copyright © 2011 S. Karger AG, Basel.
A unified theory of bone healing and nonunion: BHN theory.

PubMed

Elliott, D S; Newman, K J H; Forward, D P; Hahn, D M; Ollivere, B; Kojima, K; Handley, R; Rossiter, N D; Wixted, J J; Smith, R M; Moran, C G

2016-07-01

This article presents a unified clinical theory that links established facts about the physiology of bone and homeostasis, with those involved in the healing of fractures and the development of nonunion. The key to this theory is the concept that the tissue that forms in and around a fracture should be considered a specific functional entity. This 'bone-healing unit' produces a physiological response to its biological and mechanical environment, which leads to the normal healing of bone. This tissue responds to mechanical forces and functions according to Wolff's law, Perren's strain theory and Frost's concept of the "mechanostat". In response to the local mechanical environment, the bone-healing unit normally changes with time, producing different tissues that can tolerate various levels of strain. The normal result is the formation of bone that bridges the fracture - healing by callus. Nonunion occurs when the bone-healing unit fails either due to mechanical or biological problems or a combination of both. In clinical practice, the majority of nonunions are due to mechanical problems with instability, resulting in too much strain at the fracture site. In most nonunions, there is an intact bone-healing unit. We suggest that this maintains its biological potential to heal, but fails to function due to the mechanical conditions. The theory predicts the healing pattern of multifragmentary fractures and the observed morphological characteristics of different nonunions. It suggests that the majority of nonunions will heal if the correct mechanical environment is produced by surgery, without the need for biological adjuncts such as autologous bone graft. Cite this article: Bone Joint J 2016;98-B:884-91. ©2016 The British Editorial Society of Bone & Joint Surgery.
Proteomics of vitamin B12 processing.

PubMed

Hannibal, Luciana; DiBello, Patricia M; Jacobsen, Donald W

2013-03-01

The causes of cobalamin (B12, Cbl) deficiency are multifactorial. Whether nutritional due to poor dietary intake, or functional due to impairments in absorption or intracellular processing and trafficking events, the major symptoms of Cbl deficiency include megaloblastic anemia, neurological deterioration and in extreme cases, failure to thrive and death. The common biomarkers of Cbl deficiency (hyperhomocysteinemia and methylmalonic acidemia) are extremely valuable diagnostic indicators of the condition, but little is known about the changes that occur at the protein level. A mechanistic explanation bridging the physiological changes associated with functional B12 deficiency with its intracellular processers and carriers is lacking. In this article, we will cover the effects of B12 deficiency in a cblC-disrupted background (also referred to as MMACHC) as a model of functional Cbl deficiency. As will be shown, major protein changes involve the cytoskeleton, the neurological system as well as signaling and detoxification pathways. Supplementation of cultured MMACHC-mutant cells with hydroxocobalamin (HOCbl) failed to restore these variants to the normal phenotype, suggesting that a defective Cbl processing pathway produces irreversible changes at the protein level.
Plasma and cellular fibronectin: distinct and independent functions during tissue repair

PubMed Central

2011-01-01

Fibronectin (FN) is a ubiquitous extracellular matrix (ECM) glycoprotein that plays vital roles during tissue repair. The plasma form of FN circulates in the blood, and upon tissue injury, is incorporated into fibrin clots to exert effects on platelet function and to mediate hemostasis. Cellular FN is then synthesized and assembled by cells as they migrate into the clot to reconstitute damaged tissue. The assembly of FN into a complex three-dimensional matrix during physiological repair plays a key role not only as a structural scaffold, but also as a regulator of cell function during this stage of tissue repair. FN fibrillogenesis is a complex, stepwise process that is strictly regulated by a multitude of factors. During fibrosis, there is excessive deposition of ECM, of which FN is one of the major components. Aberrant FN-matrix assembly is a major contributing factor to the switch from normal tissue repair to misregulated fibrosis. Understanding the mechanisms involved in FN assembly and how these interplay with cellular, fibrotic and immune responses may reveal targets for the future development of therapies to regulate aberrant tissue-repair processes. PMID:21923916
Protein S-nitrosylation: specificity and identification strategies in plants

NASA Astrophysics Data System (ADS)

Lamotte, Olivier; Bertoldo, Jean; Besson-Bard, Angélique; Rosnoblet, Claire; Aimé, Sébastien; Hichami, Siham; Terenzi, Hernan; Wendehenne, David

2014-12-01

The role of nitric oxide (NO) as a major regulator of plant physiological functions has become increasingly evident. To further improve our understanding of its role, within the last few years plant biologists have begun to embrace the exciting opportunity of investigating protein S-nitrosylation, a major reversible NO-dependent post-translational modification (PTM) targeting specific Cys residues and widely studied in animals. Thanks to the development of dedicated proteomic approaches, in particular the use of the Biotin Switch Technique (BST) combined with mass spectrometry, hundreds of plant protein candidates for S-nitrosylation have been identified. Functional studies focused on specific proteins provided preliminary comprehensive views of how this PTM impacts the structure and function of proteins and, more generally, of how NO might regulate biological plant processes. The aim of this review is to detail the basic principle of protein S-nitrosylation, to provide information on the biochemical and structural features of the S-nitrosylation sites and to describe the proteomic strategies adopted to investigate this PTM in plants. Limits of the current approaches and tomorrow's challenges are also discussed.
Dietary docosahexaenoic acid supplementation alters select physiological endocannabinoid-system metabolites in brain and plasma

PubMed Central

Wood, JodiAnne T.; Williams, John S.; Pandarinathan, Lakshmipathi; Janero, David R.; Lammi-Keefe, Carol J.; Makriyannis, Alexandros

2010-01-01

The endocannabinoid metabolome consists of a growing, (patho)physiologically important family of fatty-acid derived signaling lipids. Diet is a major source of fatty acid substrate for mammalian endocannabinoid biosynthesis. The principal long-chain PUFA found in mammalian brain, docosahexaenoic acid (DHA), supports neurological function, retinal development, and overall health. The extent to which dietary DHA supplementation influences endocannabinoid-related metabolites in brain, within the context of the circulating endocannabinoid profile, is currently unknown. We report the first lipidomic analysis of acute 2-week DHA dietary supplementation effects on the physiological state of 15 fatty-acid, N-acylethanolamine, and glycerol-ester endocannabinoid metabolome constituents in murine plasma and brain. The DHA-rich diet markedly elevated DHA, eicosapentaenoic acid, 2-eicosapentanoylglycerol (EPG), and docosahexanoylethanolamine in both compartments. Dietary DHA enhancement generally affected the synthesis of the N-acyl-ethanolamine and glycerol-ester metabolites to favor the docosahexaenoic and eicosapentaenoic vs. arachidonoyl and oleoyl homologs in both brain and plasma. The greater overall responsiveness of the endocannabinoid metabolome in plasma versus brain may reflect a more circumscribed homeostatic response range of brain lipids to dietary DHA supplementation. The ability of short-term DHA enhancement to modulate select constituents of the physiological brain and plasma endocannabinoid metabolomes carries metabolic and therapeutic implications. PMID:20071693
Dietary docosahexaenoic acid supplementation alters select physiological endocannabinoid-system metabolites in brain and plasma.

PubMed

Wood, Jodianne T; Williams, John S; Pandarinathan, Lakshmipathi; Janero, David R; Lammi-Keefe, Carol J; Makriyannis, Alexandros

2010-06-01

The endocannabinoid metabolome consists of a growing, (patho)physiologically important family of fatty-acid derived signaling lipids. Diet is a major source of fatty acid substrate for mammalian endocannabinoid biosynthesis. The principal long-chain PUFA found in mammalian brain, docosahexaenoic acid (DHA), supports neurological function, retinal development, and overall health. The extent to which dietary DHA supplementation influences endocannabinoid-related metabolites in brain, within the context of the circulating endocannabinoid profile, is currently unknown. We report the first lipidomic analysis of acute 2-week DHA dietary supplementation effects on the physiological state of 15 fatty-acid, N-acylethanolamine, and glycerol-ester endocannabinoid metabolome constituents in murine plasma and brain. The DHA-rich diet markedly elevated DHA, eicosapentaenoic acid, 2-eicosapentanoylglycerol (EPG), and docosahexanoylethanolamine in both compartments. Dietary DHA enhancement generally affected the synthesis of the N-acyl-ethanolamine and glycerol-ester metabolites to favor the docosahexaenoic and eicosapentaenoic vs. arachidonoyl and oleoyl homologs in both brain and plasma. The greater overall responsiveness of the endocannabinoid metabolome in plasma versus brain may reflect a more circumscribed homeostatic response range of brain lipids to dietary DHA supplementation. The ability of short-term DHA enhancement to modulate select constituents of the physiological brain and plasma endocannabinoid metabolomes carries metabolic and therapeutic implications.
The vaginal microbiota, host defence and reproductive physiology

PubMed Central

Smith, Steven B

2016-01-01

Abstract The interaction between the human host and the vaginal microbiota is highly dynamic. Major changes in the vaginal physiology and microbiota over a woman's lifetime are largely shaped by transitional periods such as puberty, menopause and pregnancy, while daily fluctuations in microbial composition observed through culture‐independent studies are more likely to be the results of daily life activities and behaviours. The vaginal microbiota of reproductive‐aged women is largely made up of at least five different community state types. Four of these community state types are dominated by lactic‐acid producing Lactobacillus spp. while the fifth is commonly composed of anaerobes and strict anaerobes and is sometimes associated with vaginal symptoms. The production of lactic acid has been associated with contributing to the overall health of the vagina due to its direct and indirect effects on pathogens and host defence. Some species associated with non‐Lactobacillus vaginal microbiota may trigger immune responses as well as degrade the host mucosa, processes that ultimately increase susceptibility to infections and contribute to negative reproductive outcomes such as infertility and preterm birth. Further studies are needed to better understand the functional underpinnings of how the vaginal microbiota affect host physiology but also how host physiology affects the vaginal microbiota. Understanding this fine‐tuned interaction is key to maintaining women's reproductive health. PMID:27373840
Morphological Dynamics of Mitochondria – A Special Emphasis on Cardiac Muscle Cells

PubMed Central

Hom, Jennifer; Sheu, Shey-Shing

2010-01-01

Mitochondria play a critical role in cellular energy metabolism, Ca2+ homeostasis, reactive oxygen species generation, apoptosis, aging, and development. Many recent publications have shown that a continuous balance of fusion and fission of these organelles is important in maintaining their proper function. Therefore, there is a steep correlation between the form and function of mitochondria. Many major proteins involved in mitochondrial fusion and fission have been identified in different cell types, including heart. However, the functional role of mitochondrial dynamics in the heart remains, for the most part, unexplored. In this review we will cover the recent field of mitochondrial dynamics and its physiological and pathological implications, with a particular emphasis on the experimental and theoretical basis of mitochondrial dynamics in the heart. PMID:19281816
Cytochrome P450 and Lipoxygenase Metabolites on Renal Function

PubMed Central

Imig, John D.; Hye Khan, Md. Abdul

2018-01-01

Arachidonic acid metabolites have a myriad of biological actions including effects on the kidney to alter renal hemodynamics and tubular transport processes. Cyclooxygenase metabolites are products of an arachidonic acid enzymatic pathway that has been extensively studied in regards to renal function. Two lesser-known enzymatic pathways of arachidonic acid metabolism are the lipoxygenase (LO) and cytochrome P450 (CYP) pathways. The importance of LO and CYP metabolites to renal hemodynamics and tubular transport processes is now being recognized. LO and CYP metabolites have actions to alter renal blood flow and glomerular filtration rate. Proximal and distal tubular sodium transport and fluid and electrolyte homeostasis are also significantly influenced by renal CYP and LO levels. Metabolites of the LO and CYP pathways also have renal actions that influence renal inflammation, proliferation, and apoptotic processes at vascular and epithelial cells. These renal LO and CYP pathway actions occur through generation of specific metabolites and cell-signaling mechanisms. Even though the renal physiological importance and actions for LO and CYP metabolites are readily apparent, major gaps remain in our understanding of these lipid mediators to renal function. Future studies will be needed to fill these major gaps regarding LO and CYP metabolites on renal function. PMID:26756638
Toward reliable retrieval of functional information of papillary dermis using spatially resolved diffuse reflectance spectroscopy

PubMed Central

Chen, Yu-Wen; Guo, Jun-Yen; Tzeng, Shih-Yu; Chou, Ting-Chun; Lin, Ming-Jen; Huang, Lynn Ling-Huei; Yang, Chao-Chun; Hsu, Chao-Kai; Tseng, Sheng-Hao

2016-01-01

Spatially resolved diffuse reflectance spectroscopy (SRDRS) has been employed to quantify tissue optical properties and its interrogation volume is majorly controlled by the source-to-detector separations (SDSs). To noninvasively quantify properties of dermis, a SRDRS setup that includes SDS shorter than 1 mm is required. It will be demonstrated in this study that Monte Carlo simulations employing the Henyey-Greenstein phase function cannot always precisely predict experimentally measured diffuse reflectance at such short SDSs, and we speculated this could be caused by the non-negligible backward light scattering at short SDSs that cannot be properly modeled by the Henyey-Greenstein phase function. To accurately recover the optical properties and functional information of dermis using SRDRS, we proposed the use of the modified two-layer (MTL) geometry. Monte Carlo simulations and phantom experiment results revealed that the MTL probing geometry was capable of faithfully recovering the optical properties of upper dermis. The capability of the MTL geometry in probing the upper dermis properties was further verified through a swine study, and it was found that the measurement results were reasonably linked to histological findings. Finally, the MTL probe was utilized to study psoriatic lesions. Our results showed that the MTL probe was sensitive to the physiological condition of tissue volumes within the papillary dermis and could be used in studying the physiology of psoriasis. PMID:26977361
Diversity and functions of protein glycosylation in insects.

PubMed

Walski, Tomasz; De Schutter, Kristof; Van Damme, Els J M; Smagghe, Guy

2017-04-01

The majority of proteins is modified with carbohydrate structures. This modification, called glycosylation, was shown to be crucial for protein folding, stability and subcellular location, as well as protein-protein interactions, recognition and signaling. Protein glycosylation is involved in multiple physiological processes, including embryonic development, growth, circadian rhythms, cell attachment as well as maintenance of organ structure, immunity and fertility. Although the general principles of glycosylation are similar among eukaryotic organisms, insects synthesize a distinct repertoire of glycan structures compared to plants and vertebrates. Consequently, a number of unique insect glycans mediate functions specific to this class of invertebrates. For instance, the core α1,3-fucosylation of N-glycans is absent in vertebrates, while in insects this modification is crucial for the development of wings and the nervous system. At present, most of the data on insect glycobiology comes from research in Drosophila. Yet, progressively more information on the glycan structures and the importance of glycosylation in other insects like beetles, caterpillars, aphids and bees is becoming available. This review gives a summary of the current knowledge and recent progress related to glycan diversity and function(s) of protein glycosylation in insects. We focus on N- and O-glycosylation, their synthesis, physiological role(s), as well as the molecular and biochemical basis of these processes. Copyright © 2017 Elsevier Ltd. All rights reserved.
PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana

PubMed Central

Balfanz, Sabine

2017-01-01

The catecholamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. In insects; these neuroactive substances are functionally replaced by the phenolamines octopamine and tyramine. Phenolamines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Type 1 tyramine receptors are better activated by tyramine than by octopamine. In contrast; type 2 tyramine receptors are almost exclusively activated by tyramine. Functionally; activation of type 1 tyramine receptors leads to a decrease in the intracellular concentration of cAMP ([cAMP]i) whereas type 2 tyramine receptors can mediate Ca2+ signals or both Ca2+ signals and effects on [cAMP]i. Here; we report that the American cockroach (Periplaneta americana) expresses a second type 1 tyramine receptor (PeaTAR1B) in addition to PeaTAR1A (previously called PeaTYR1). When heterologously expressed in flpTM cells; activation of PeaTAR1B by tyramine leads to a concentration-dependent decrease in [cAMP]i. Its activity can be blocked by a series of established antagonists. The functional characterization of two type 1 tyramine receptors from P. americana; PeaTAR1A and PeaTAR1B; which respond to tyramine by changing cAMP levels; is a major step towards understanding the actions of tyramine in cockroach physiology and behavior; particularly in comparison to the effects of octopamine. PMID:29084141
PeaTAR1B: Characterization of a Second Type 1 Tyramine Receptor of the American Cockroach, Periplaneta americana.

PubMed

Blenau, Wolfgang; Balfanz, Sabine; Baumann, Arnd

2017-10-30

The catecholamines norepinephrine and epinephrine regulate important physiological functions in vertebrates. In insects; these neuroactive substances are functionally replaced by the phenolamines octopamine and tyramine. Phenolamines activate specific guanine nucleotide-binding (G) protein-coupled receptors (GPCRs). Type 1 tyramine receptors are better activated by tyramine than by octopamine. In contrast; type 2 tyramine receptors are almost exclusively activated by tyramine. Functionally; activation of type 1 tyramine receptors leads to a decrease in the intracellular concentration of cAMP ([cAMP] i ) whereas type 2 tyramine receptors can mediate Ca 2+ signals or both Ca 2+ signals and effects on [cAMP] i . Here; we report that the American cockroach ( Periplaneta americana ) expresses a second type 1 tyramine receptor (PeaTAR1B) in addition to PeaTAR1A (previously called PeaTYR1). When heterologously expressed in flpTM cells; activation of PeaTAR1B by tyramine leads to a concentration-dependent decrease in [cAMP] i . Its activity can be blocked by a series of established antagonists. The functional characterization of two type 1 tyramine receptors from P. americana ; PeaTAR1A and PeaTAR1B; which respond to tyramine by changing cAMP levels; is a major step towards understanding the actions of tyramine in cockroach physiology and behavior; particularly in comparison to the effects of octopamine.
Toward reliable retrieval of functional information of papillary dermis using spatially resolved diffuse reflectance spectroscopy.

PubMed

Chen, Yu-Wen; Guo, Jun-Yen; Tzeng, Shih-Yu; Chou, Ting-Chun; Lin, Ming-Jen; Huang, Lynn Ling-Huei; Yang, Chao-Chun; Hsu, Chao-Kai; Tseng, Sheng-Hao

2016-02-01

Spatially resolved diffuse reflectance spectroscopy (SRDRS) has been employed to quantify tissue optical properties and its interrogation volume is majorly controlled by the source-to-detector separations (SDSs). To noninvasively quantify properties of dermis, a SRDRS setup that includes SDS shorter than 1 mm is required. It will be demonstrated in this study that Monte Carlo simulations employing the Henyey-Greenstein phase function cannot always precisely predict experimentally measured diffuse reflectance at such short SDSs, and we speculated this could be caused by the non-negligible backward light scattering at short SDSs that cannot be properly modeled by the Henyey-Greenstein phase function. To accurately recover the optical properties and functional information of dermis using SRDRS, we proposed the use of the modified two-layer (MTL) geometry. Monte Carlo simulations and phantom experiment results revealed that the MTL probing geometry was capable of faithfully recovering the optical properties of upper dermis. The capability of the MTL geometry in probing the upper dermis properties was further verified through a swine study, and it was found that the measurement results were reasonably linked to histological findings. Finally, the MTL probe was utilized to study psoriatic lesions. Our results showed that the MTL probe was sensitive to the physiological condition of tissue volumes within the papillary dermis and could be used in studying the physiology of psoriasis.
A worldwide analysis of within-canopy variations in leaf structural, chemical and physiological traits across plant functional types.

PubMed

Niinemets, Ülo; Keenan, Trevor F; Hallik, Lea

2015-02-01

Extensive within-canopy light gradients importantly affect the photosynthetic productivity of leaves in different canopy positions and lead to light-dependent increases in foliage photosynthetic capacity per area (AA). However, the controls on AA variations by changes in underlying traits are poorly known. We constructed an unprecedented worldwide database including 831 within-canopy gradients with standardized light estimates for 304 species belonging to major vascular plant functional types, and analyzed within-canopy variations in 12 key foliage structural, chemical and physiological traits by quantitative separation of the contributions of different traits to photosynthetic acclimation. Although the light-dependent increase in AA is surprisingly similar in different plant functional types, they differ fundamentally in the share of the controls on AA by constituent traits. Species with high rates of canopy development and leaf turnover, exhibiting highly dynamic light environments, actively change AA by nitrogen reallocation among and partitioning within leaves. By contrast, species with slow leaf turnover exhibit a passive AA acclimation response, primarily determined by the acclimation of leaf structure to growth light. This review emphasizes that different combinations of traits are responsible for within-canopy photosynthetic acclimation in different plant functional types, and solves an old enigma of the role of mass- vs area-based traits in vegetation acclimation. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

The Graphical Representation of the Digital Astronaut Physiology Backbone

NASA Technical Reports Server (NTRS)

Briers, Demarcus

2010-01-01

This report summarizes my internship project with the NASA Digital Astronaut Project to analyze the Digital Astronaut (DA) physiology backbone model. The Digital Astronaut Project (DAP) applies integrated physiology models to support space biomedical operations, and to assist NASA researchers in closing knowledge gaps related to human physiologic responses to space flight. The DA physiology backbone is a set of integrated physiological equations and functions that model the interacting systems of the human body. The current release of the model is HumMod (Human Model) version 1.5 and was developed over forty years at the University of Mississippi Medical Center (UMMC). The physiology equations and functions are scripted in an XML schema specifically designed for physiology modeling by Dr. Thomas G. Coleman at UMMC. Currently it is difficult to examine the physiology backbone without being knowledgeable of the XML schema. While investigating and documenting the tags and algorithms used in the XML schema, I proposed a standard methodology for a graphical representation. This standard methodology may be used to transcribe graphical representations from the DA physiology backbone. In turn, the graphical representations can allow examination of the physiological functions and equations without the need to be familiar with the computer programming languages or markup languages used by DA modeling software.
Physiology and Assessment as Low-Hanging Fruit for Education Overhaul

ERIC Educational Resources Information Center

Ribeiro, Sidarta; Mota, Natália Bezerra; da Rocha Fernandes, Valter; Deslandes, Andrea Camaz; Brockington, Guilherme; Copelli, Mauro

2016-01-01

Physiology and assessment constitute major bottlenecks of school learning among students with low socioeconomic status. The limited resources and household overcrowding typical of poverty produce deficits in nutrition, sleep, and exercise that strongly hinder physiology and hence learning. Likewise, overcrowded classrooms hamper the assessment of…
Diet around conception and during pregnancy--effects on fetal and neonatal outcomes.

PubMed

Kind, Karen L; Moore, Vivienne M; Davies, Michael J

2006-05-01

Substrate supply to the fetus is a major regulator of prenatal growth. Maternal nutrition influences the availability of nutrients for transfer to the fetus. Animal experiments demonstrate that restriction of maternal protein or energy intake can retard fetal growth. Effects of maternal nutrition vary with the type and timing of the restriction and the species studied. Maternal undernutrition before conception and/or in early pregnancy can alter fetal physiology in late gestation, and influence postnatal function, often without measurable effects on birth size. In contrast, to date, observational and intervention studies in humans provide limited support for a major role of maternal nutrition in determining birth size, except where women are quite malnourished. However, recent studies report associations between newborn size and the balance of macronutrients in women's diets in Western settings. Associations between maternal dietary composition and adult blood pressure of the offspring are also reported in human populations. Most studies in women have focused on dietary content or supplementation during mid-late pregnancy. Further investigation of how maternal dietary composition, before conception and throughout pregnancy, affects fetal physiology and health of the baby will increase the understanding of how maternal diet and nutritional status influence fetal, neonatal and longer-term outcomes.
Quantifying the vitamin D economy.

PubMed

Heaney, Robert P; Armas, Laura A G

2015-01-01

Vitamin D enters the body through multiple routes and in a variety of chemical forms. Utilization varies with input, demand, and genetics. Vitamin D and its metabolites are carried in the blood on a Gc protein that has three principal alleles with differing binding affinities and ethnic prevalences. Three major metabolites are produced, which act via two routes, endocrine and autocrine/paracrine, and in two compartments, extracellular and intracellular. Metabolic consumption is influenced by physiological controls, noxious stimuli, and tissue demand. When administered as a supplement, varying dosing schedules produce major differences in serum metabolite profiles. To understand vitamin D's role in human physiology, it is necessary both to identify the foregoing entities, mechanisms, and pathways and, specifically, to quantify them. This review was performed to delineate the principal entities and transitions involved in the vitamin D economy, summarize the status of present knowledge of the applicable rates and masses, draw inferences about functions that are implicit in these quantifications, and point out implications for the determination of adequacy. © The Author(s) 2014. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Detection and quantification of S-nitrosoglutathione (GSNO) in pepper (Capsicum annuum L.) plant organs by LC-ES/MS.

PubMed

Airaki, Morad; Sánchez-Moreno, Lourdes; Leterrier, Marina; Barroso, Juan B; Palma, José M; Corpas, Francisco J

2011-11-01

Glutathione (GSH) is one of the major, soluble, low molecular weight antioxidants, as well as the major non-protein thiol in plant cells. However, the relevance of this molecule could be even greater considering that it can react with nitric oxide (NO) to generate S-nitrosoglutathione (GSNO) which is considered to function as a mobile reservoir of NO bioactivity in plants. Although this NO-derived molecule has an increased physiological and phytopathological relevance in plants cells, its identification and quantification in plant tissues have not be reported so far. Using liquid chromatography-electrospray/mass spectrometry (LC-ES/MS), a method was set up to detect and quantify simultaneously GSNO as well reduced and oxidized glutathione (GSH and GSSG, respectively) in different pepper plant organs including roots, stems and leaves, and in Arabidopsis leaves. The analysis of NO and GSNO reductase (GSNOR) activity in these pepper organs showed that the content of GSNO was directly related to the content of NO in each organ and oppositely related to the GSNOR activity. This approach opens up new analytical possibilities to understand the relevance of GSNO in plant cells under physiological and stress conditions.
Role of ACTH in the Interactive/Paracrine Regulation of Adrenal Steroid Secretion in Physiological and Pathophysiological Conditions

PubMed Central

Lefebvre, Hervé; Thomas, Michaël; Duparc, Céline; Bertherat, Jérôme; Louiset, Estelle

2016-01-01

In the normal human adrenal gland, steroid secretion is regulated by a complex network of autocrine/paracrine interactions involving bioactive signals released by endothelial cells, nerve terminals, chromaffin cells, immunocompetent cells, and adrenocortical cells themselves. ACTH can be locally produced by medullary chromaffin cells and is, therefore, a major mediator of the corticomedullary functional interplay. Plasma ACTH also triggers the release of angiogenic and vasoactive agents from adrenocortical cells and adrenal mast cells and, thus, indirectly regulates steroid production through modulation of the adrenal blood flow. Adrenocortical neoplasms associated with steroid hypersecretion exhibit molecular and cellular defects that tend to reinforce the influence of paracrine regulatory loops on corticosteroidogenesis. Especially, ACTH has been found to be abnormally synthesized in bilateral macronodular adrenal hyperplasia responsible for hypercortisolism. In these tissues, ACTH is detected in a subpopulation of adrenocortical cells that express gonadal markers. This observation suggests that ectopic production of ACTH may result from impaired embryogenesis leading to abnormal maturation of the adrenogonadal primordium. Globally, the current literature indicates that ACTH is a major player in the autocrine/paracrine processes occurring in the adrenal gland in both physiological and pathological conditions. PMID:27489549
Intestinal Microbiota: Facts and Fiction.

PubMed

Kverka, Miloslav; Tlaskalová-Hogenová, Helena

2017-01-01

In humans, the gut microbiota forms a complex ecosystem consisting of a vast number of bacteria, Archaea, fungi and viruses. It represents a major stimulus to the development of the immune system and many other physiological functions, so that it may shape the individual's susceptibility to infectious and immune-mediated diseases. The emergence of new '-omics' methods recently revolutionized the way we study the host-microbe interactions, but they also raised new questions and issues. In this review, we discuss the impact of these new data on the current and future therapies for chronic inflammatory diseases. We also outline the major conceptual, technical and interpretational issues that recently led to some misleading conclusions and discuss in brief the current research directions in the field. © 2017 S. Karger AG, Basel.
Effects of Exercise on Physiological and Psychological Variables in Cancer Survivors.

ERIC Educational Resources Information Center

Burnham, Timothy; Wilcox, Anthony

2002-01-01

Investigated the effect of aerobic exercise on physiological and psychological function in people rehabilitating from cancer treatment. Data on people participating in control, moderate-intensity exercise, and low-intensity exercise groups indicated that both exercise programs were equally effective in improving physiological function,…
The Physiological Profile of Trained Female Dance Majors.

ERIC Educational Resources Information Center

Rimmer, James H.; And Others

This investigation studied the physiological profiles of eight highly trained female dance majors. To be considered highly trained, each subject had to be dancing a minimum of three hours a day, four to five days a week, for the last year. They also had to meet the criterion of dancing at least ten hours a week for the last five years prior to…
Estrogen Biology: New Insights into GPER Function and Clinical Opportunities

PubMed Central

Prossnitz, Eric R.; Barton, Matthias

2014-01-01

Estrogens play an important role in the regulation of normal physiology, aging and many disease states. Although the nuclear estrogen receptors have classically been described to function as ligand-activated transcription factors mediating genomic effects in hormonally regulated tissues, more recent studies reveal that estrogens also mediate rapid signaling events traditionally associated with G protein-coupled receptors. The G protein-coupled estrogen receptor GPER (formerly GPR30) has now become recognized as a major mediator of estrogen’s rapid cellular effects throughout the body. With the discovery of selective synthetic ligands for GPER, both agonists and antagonists, as well as the use of GPER knockout mice, significant advances have been made in our understanding of GPER function at the cellular, tissue and organismal levels. In many instances, the protective/beneficial effects of estrogen are mimicked by selective GPER agonism and are absent or reduced in GPER knockout mice, suggesting an essential or at least parallel role for GPER in the actions of estrogen. In this review, we will discuss recent advances and our current understanding of the role of GPER and certain drugs such as SERMs and SERDs in physiology and disease. We will also highlight novel opportunities for clinical development towards GPER-targeted therapeutics, for molecular imaging, as well as for theranostic approaches and personalized medicine. PMID:24530924
Biological clocks: their relevance to immune-allergic diseases.

PubMed

Paganelli, Roberto; Petrarca, Claudia; Di Gioacchino, Mario

2018-01-01

The 2017 Nobel Prize for Physiology or Medicine, awarded for the discoveries made in the past 15 years on the genetic and molecular mechanisms regulating many physiological functions, has renewed the attention to the importance of circadian rhythms. These originate from a central pacemaker in the suprachiasmatic nucleus in the brain, photoentrained via direct connection with melanopsin containing, intrinsically light-sensitive retinal ganglion cells, and it projects to periphery, thus creating an inner circadian rhythm. This regulates several activities, including sleep, feeding times, energy metabolism, endocrine and immune functions. Disturbances of these rhythms, mainly of wake/sleep, hormonal secretion and feeding, cause decrease in quality of life, as well as being involved in development of obesity, metabolic syndrome and neuropsychiatric disorders. Most immunological functions, from leukocyte numbers, activity and cytokine secretion undergo circadian variations, which might affect susceptibility to infections. The intensity of symptoms and disease severity show a 24 h pattern in many immunological and allergic diseases, including rheumatoid arthritis, bronchial asthma, atopic eczema and chronic urticaria. This is accompanied by altered sleep duration and quality, a major determinant of quality of life. Shift work and travel through time zones as well as artificial light pose new health threats by disrupting the circadian rhythms. Finally, the field of chronopharmacology uses these concepts for delivering drugs in synchrony with biological rhythms.
Active migration is associated with specific and consistent changes to gut microbiota in Calidris shorebirds.

PubMed

Risely, Alice; Waite, David W; Ujvari, Beata; Hoye, Bethany J; Klaassen, Marcel

2018-03-01

Gut microbes are increasingly recognised for their role in regulating an animal's metabolism and immunity. However, identifying repeatable associations between host physiological processes and their gut microbiota has proved challenging, in part because microbial communities often respond stochastically to host physiological stress (e.g. fasting, forced exercise or infection). Migratory birds provide a valuable system in which to test host-microbe interactions under physiological extremes because these hosts are adapted to predictable metabolic and immunological challenges as they undergo seasonal migrations, including temporary gut atrophy during long-distance flights. These physiological challenges may either temporarily disrupt gut microbial ecosystems, or, alternatively, promote predictable host-microbe associations during migration. To determine the relationship between migration and gut microbiota, we compared gut microbiota composition between migrating and non-migrating ("resident") conspecific shorebirds sharing a flock. We performed this across two sandpiper species, Calidris ferruginea and Calidris ruficollis, in north-western Australia, and an additional C. ruficollis population 3,000 km away in southern Australia. We found that migrants consistently had higher abundances of the bacterial genus Corynebacterium (average 28% abundance) compared to conspecific residents (average <1% abundance), with this effect holding across both species and sites. However, other than this specific association, community structure and diversity was almost identical between migrants and residents, with migration status accounting for only 1% of gut community variation when excluding Corynebacterium. Our findings suggest a consistent relationship between Corynebacterium and Calidris shorebirds during migration, with further research required to identify causal mechanisms behind the association, and to elucidate functionality to the host. However, outside this specific association, migrating shorebirds broadly maintained gut community structure, which may allow them to quickly recover gut function after a migratory flight. This study provides a rare example of a repeatable and specific response of the gut microbiota to a major physiological challenge across two species and two distant populations. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.
Effects of selective serotonin reuptake inhibitor treatment on plasma oxytocin and cortisol in major depressive disorder.

PubMed

Keating, Charlotte; Dawood, Tye; Barton, David A; Lambert, Gavin W; Tilbrook, Alan J

2013-04-29

Oxytocin is known for its capacity to facilitate social bonding, reduce anxiety and for its actions on the stress hypothalamopituitary adrenal (HPA) axis. Since oxytocin can physiologically suppress activity of the HPA axis, clinical applications of this neuropeptide have been proposed in conditions where the function of the HPA axis is dysregulated. One such condition is major depressive disorder (MDD). Dysregulation of the HPA system is the most prominent endocrine change seen with MDD, and normalizing the HPA axis is one of the major targets of recent treatments. The potential clinical application of oxytocin in MDD requires improved understanding of its relationship to the symptoms and underlying pathophysiology of MDD. Previous research has investigated potential correlations between oxytocin and symptoms of MDD, including a link between oxytocin and treatment related symptom reduction. The outcomes of studies investigating whether antidepressive treatment (pharmacological and non-pharmacological) influences oxytocin concentrations in MDD, have produced conflicting outcomes. These outcomes suggest the need for an investigation of the influence of a single treatment class on oxytocin concentrations, to determine whether there is a relationship between oxytocin, the HPA axis (e.g., oxytocin and cortisol) and MDD. Our objective was to measure oxytocin and cortisol in patients with MDD before and following treatment with selective serotonin reuptake inhibitors, SSRI. We sampled blood from arterial plasma. Patients with MDD were studied at the same time twice; pre- and post- 12 weeks treatment, in an unblinded sequential design (clinicaltrials.govNCT00168493). Results did not reveal differences in oxytocin or cortisol concentrations before relative to following SSRI treatment, and there were no significant relationships between oxytocin and cortisol, or these two physiological variables and psychological symptom scores, before or after treatment. These outcomes demonstrate that symptoms of MDD were reduced following effective treatment with an SSRI, and further, stress physiology was unlikely to be a key factor in this outcome. Further research is required to discriminate potential differences in underlying stress physiology for individuals with MDD who respond to antidepressant treatment, relative to those who experience treatment resistance.
Sexual Functioning in Men Living with a Spinal Cord Injury–A Narrative Literature Review

PubMed Central

Sunilkumar, MM; Boston, Patricia; Rajagopal, MR

2015-01-01

Background: Sexual dysfunction is a major concern for Indian men living with a spinal cord injury Objectives: To examine the literature related to sexuality traumatic cord injury and its impact on sexual functioning. Materials and Methods: Databases using Cumulative Index to Nursing and Allied Health Literature (CINAHL) 2000–2012, Medline 1989–2012, Applied Social Sciences Index and Abstracts (ASSIA) 1989–2012 and Google Scholar were the search engines used used for literature review. Results: The search yielded a total of 457 articles and only 75 of them were found relevant. The minimum number of articles required to meet the inclusion criteria for this review was 25–30 articles. Out of the 75 articles, 33 were considered relevant or related to the topic of sexual functioning, spinal cord injury, and paraplegia. Six areas were identified: Sexual stigmatization, physiological barriers to sexual satisfaction, clinical aspects of sexual functioning, biomedical approaches to sexual dysfunction, partner satisfaction, and lack of accessibility to sexual education. Conclusion: Spinal cord injury and sexual functioning affects a large segment of the male Indian population, yet most current research focuses on quantitative measurement with the emphasis on ejaculatory dysfunction, orgasm impairment, incontinence, and other physiological dysfunction. Further research is needed to address the subjective accounts of patients themselves with respect to the emotional and social impact of sexual disability. This would help to identify the best possible outcomes for both treatment and rehabilitation. PMID:26600694
The psyche and gastric functions.

PubMed

Nardone, Gerardo; Compare, Debora

2014-01-01

Although the idea that gastric problems are in some way related to mental activity dates back to the beginning of the last century, until now it has received scant attention by physiologists, general practitioners and gastroenterologists. The major breakthrough in understanding the interactions between the central nervous system and the gut was the discovery of the enteric nervous system (ENS) in the 19th century. ENS (also called 'little brain') plays a crucial role in the regulation of the physiological gut functions. Furthermore, the identification of corticotropin-releasing factor (CRF) and the development of specific CRF receptor antagonists have permitted to characterize the neurochemical basis of the stress response. The neurobiological response to stress in mammals involves three key mechanisms: (1) stress is perceived and processed by higher brain centers; (2) the brain mounts a neuroendocrine response by way of the hypothalamic-pituitary-adrenal axis (HPA) and the autonomic nervous system (ANS), and (3) the brain triggers feedback mechanisms by HPA and ANS stimulation to restore homeostasis. Various stressors such as anger, fear, painful stimuli, as well as life or social learning experiences affect both the individual's physiologic and gastric function, revealing a two-way interaction between brain and stomach. There is overwhelming experimental and clinical evidence that stress influences gastric function, thereby outlining the pathogenesis of gastric diseases such as functional dyspepsia, gastroesophageal reflux disease and peptic ulcer disease. A better understanding of the role of pathological stressors in the modulation of disease activity may have important pathogenetic and therapeutic implications. © 2014 S. Karger AG, Basel.
Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product

PubMed Central

Crum, Alia J.; Phillips, Damon J.; Goyer, J. Parker; Akinola, Modupe; Higgins, E. Tory

2016-01-01

This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, “AquaCharge Energy Water,” falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water. PMID:27875567
Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product.

PubMed

Crum, Alia J; Phillips, Damon J; Goyer, J Parker; Akinola, Modupe; Higgins, E Tory

2016-01-01

This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, "AquaCharge Energy Water," falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water.
Shared Physiological and Molecular Responses in Marine Fish and Invertebrates to Environmental Hypoxia: Potential Biomarkers of Adverse Impacts on Marine Communities

NASA Astrophysics Data System (ADS)

Thomas, P.; Rahman, S.

2016-02-01

Knowledge of the effects of environmental exposure to hypoxia (dissolved oxygen: <2 mg/L) on critical physiological functions such as reproduction, growth and metabolism in both fish and invertebrates is essential for accurate predictions of its chronic impacts on marine communities. Marked disruption of reproduction and its endocrine control was observed in Atlantic croaker collected from the hypoxic region in the northern Gulf of Mexico. Recent research has shown that growth and its physiological upregulation is also impaired in hypoxia-exposed marine fish. Expression of insulin-like growth factor (IGF) binding protein (IGFBP), which inhibits growth, was increased in croaker livers, whereas plasma levels of IGF, the primary regulator of growth, were decreased in snapper after hypoxia exposure. In addition, hypoxia inducible factor-1 (HIF-1), which regulates changes in metabolism during adaptation to hypoxia, was upregulated in croaker collected from hypoxic environments. Interestingly, similar changes in the expression of IGFBP and HIF-1 have been found in marine crustaceans after hypoxia exposure, suggesting these responses to hypoxia are common to marine fish and invertebrates. Preliminary field studies indicate that hypoxia exposure also causes epigenetic modifications, including increases in global DNA methylation, and that these epigenetic changes can influence reproduction and growth in croaker. Epigenetic modifications can be passed to offspring and persist in future generations no longer exposed to an environmental stressor further aggravating its long-term adverse impacts on population abundance and delaying recovery. The growing availability of complete invertebrate genomes and high-throughput DNA sequencing indicates similar epigenetic studies can now be conducted with marine invertebrates. Collectively, the results indicate that environmental hypoxia exposure disrupts major physiological functions in fish and invertebrates critical for maintenance of their populations.
Bone and muscle endocrine functions: Unexpected paradigms of inter-organ communication

PubMed Central

Karsenty, Gerard; Olson, Eric N.

2016-01-01

Most physiological functions originate with the communication between organs. Mouse genetics has revived this holistic view of physiology through the identification of inter-organ communications that are unanticipated, functionally important and would have been difficult to uncover otherwise. This review highlights this point by showing how two tissues usually not seen as endocrine ones, bone and striated muscles, influence in a significant manner several physiological processes. PMID:26967290
Evolving pharmacology of orphan GPCRs: IUPHAR Commentary.

PubMed

Davenport, Anthony P; Harmar, Anthony J

2013-10-01

The award of the 2012 Nobel Prize in Chemistry to Robert Lefkowitz and Brian Kobilka for their work on the structure and function of GPCRs, spanning a period of more than 20 years from the cloning of the human β2 -adrenoceptor to determining the crystal structure of the same protein, has earned both researchers a much deserved place in the pantheon of major scientific discoveries. GPCRs comprise one of the largest families of proteins, controlling many major physiological processes and have been a major focus of the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature and Drug Classification (NC-IUPHAR) since its inception in 1987. We report here recent efforts by the British Pharmacological Society and NC-IUPHAR to define the endogenous ligands of 'orphan' GPCRs and to place authoritative and accessible information about these crucial therapeutic targets online. © 2013 The British Pharmacological Society.

Mesenchymal Stem Cells for Osteochondral Tissue Engineering

PubMed Central

Ng, Johnathan; Bernhard, Jonathan; Vunjak-Novakovic, Gordana

2017-01-01

Summary Mesenchymal stem cells (MSC) are of major interest to regenerative medicine, because of the ease of harvesting from a variety of sources (including bone marrow and fat aspirates) and ability to form a range of mesenchymal tissues, in vitro and in vivo. We focus here on the use of MSCs for engineering of cartilage, bone, and complex osteochondral tissue constructs, using protocols that replicate some aspects of the natural mesodermal development. For engineering of human bone, we discuss some of the current advances, and highlight the use of perfusion bioreactors for supporting anatomically exact human bone grafts. For engineering of human cartilage, we discuss limitations of current approaches, and highlight engineering of stratified, mechanically functional human cartilage interfaced with bone by mesenchymal condensation of MSCs. Taken together, the current advances enable engineering physiologically relevant bone, cartilage and osteochondral composites, and physiologically relevant studies of osteochondral development and disease. PMID:27236665
Smolt physiology and endocrinology: Chapter 5

USGS Publications Warehouse

McCormick, Stephen D.; McCormick, Stephen D.; Farrell, Anthony Peter; Brauner, Colin J.

2012-01-01

The parr-smolt transformation of anadromous salmonids is a suite of behavioral, morphological, and physiological changes that are preparatory for downstream migration and seawater entry. The timing of smolt development varies among species, occurring soon after hatching in pink and chum salmon and after one to several years in Atlantic salmon. In many species the transformation is size dependent and occurs in spring, mediated through photoperiod and temperature cues. Smolt development is stimulated by several hormones including growth hormone, insulin-like growth factor-1, cortisol, and thyroid hormones, whereas prolactin is generally inhibitory. Increased salinity tolerance is one of the most important and tractable changes, and is caused by alteration in the function of the major osmoregulatory organs, the gill, gut, and kidney. Increased abundance of specific ion transporters (Na+/K+-ATPase, Na+/K+/Cl− cotransporter and apical Cl− channel) in gill ionocytes results in increased salt secretory capacity, increased growth and swimming performance in seawater, and higher marine survival.
Vasculature on the clock: Circadian rhythm and vascular dysfunction.

PubMed

Crnko, Sandra; Cour, Martin; Van Laake, Linda W; Lecour, Sandrine

2018-05-17

The master mammalian circadian clock (i.e. central clock), located in the suprachiasmatic nucleus of the hypothalamus, orchestrates the synchronization of the daily behavioural and physiological rhythms to better adapt the organism to the external environment in an anticipatory manner. This central clock is entrained by a variety of signals, the best established being light and food. However, circadian cycles are not simply the consequences of these two cues but are generated by endogenous circadian clocks. Indeed, clock machinery is found in mainly all tissues and cell types, including cells of the vascular system such as endothelial cells, fibroblasts, smooth muscle cells and stem cells. This machinery physiologically contributes to modulate the daily vascular function, and its disturbance therefore plays a major role in the pathophysiology of vascular dysfunction. Therapies targeting the circadian rhythm may therefore be of benefit against vascular disease. Copyright © 2018 Elsevier Inc. All rights reserved.
Insights into the selective binding and toxic mechanism of microcystin to catalase

NASA Astrophysics Data System (ADS)

Hu, Yuandong; Da, Liangjun

2014-03-01

Microcystin is a sort of cyclic nonribosomal peptides produced by cyanobacteria. It is cyanotoxin, which can be very toxic for plants and animals including humans. The present study evaluated the interaction of microcystin and catalase, under physiological conditions by means of fluorescence, three-dimensional (3D) fluorescence, circular dichroism (CD), Fourier Transform infrared (FT-IR) spectroscopy, and enzymatic reactionkinetic techniques. The fluorescence data showed that microcystin could bind to catalase to form a complex. The binding process was a spontaneous molecular interaction procedure, in which electrostatic interactions played a major role. Energy transfer and fluorescence studies proved the existence of a static binding process. Additionally, as shown by the three-dimensional fluorescence, CD and FT-IR results, microcystin could lead to conformational and microenvironmental changes of the protein, which may affect the physiological functions of catalase. The work provides important insights into the toxicity mechanism of microcystin in vivo.
The Effects of Environment and Physiological Cyclicity on the Immune System of Viperinae

PubMed Central

Kobolkuti, Lorand; Cadar, Daniel; Czirjak, Gabor; Niculae, Mihaela; Kiss, Timea; Sandru, Carmen; Spinu, Marina

2012-01-01

One of the important aspects of species' survival is connected with global climate changes, which also conditions the epidemiology of infectious diseases. Poikilotherms are exposed, as other species, to climatic influence, especially due to their physiological peculiarities such as important stages of their life cycle: hibernation, shedding, and active phase. The immune system serves as an accurate indicator of the health status and stress levels in these species. This study aimed to monitor the changes of innate (leukocyte subpopulations and total immune globulins) and adaptive immunity (in vitro leukocyte blast transformation) of two viper species, V. berus berus and V. ammodytes ammodytes, endemic in Europe and spread in different regions of Romania during their three major life cycles, hibernation, shedding, and active phase. The results indicated that seasonal variance and cycle rather than species and regional distribution influence the functionality of the immune system. PMID:22547989
Taxonomic composition and physiological and biochemical properties of bacteria in the digestive tracts of earthworms

NASA Astrophysics Data System (ADS)

Byzov, B. A.; Tikhonov, V. V.; Nechitailo, T. Yu.; Demin, V. V.; Zvyagintsev, D. G.

2015-03-01

Several hundred bacterial strains belonging to different taxa were isolated and identified from the digestive tracts of soil and compost earthworms. Some physiological and biochemical properties of the bacteria were characterized. The majority of intestinal bacteria in the earthworms were found to be facultative anaerobes. The intestinal isolates as compared to the soil ones had elevated activity of proteases and dehydrogenases. In addition, bacteria associated with earthworms' intestines are capable of growth on humic acids as a sole carbon source. Humic acid stimulated the growth of the intestinal bacteria to a greater extent than those of the soil ones. In the digestive tracts, polyphenol oxidase activity was found. Along with the data on the taxonomic separation of the intestinal bacteria, the features described testified to the presence of a group of bacteria in the earthworms intestines that is functionally characteristic and is different from the soil bacteria.
High Altitude Pulmonary Hypertension: Role of K+ and Ca2+ Channels

PubMed Central

Remillard, Carmelle V.; Yuan, Jason X.-J.

2006-01-01

Global alveolar hypoxia, as experienced at high-altitude living, has a serious impact on vascular physiology, particular on the pulmonary vasculature. The effects of sustained hypoxia on pulmonary arteries include sustained vasoconstriction and enhanced medial hypertrophy. As the major component of the vascular media, pulmonary artery smooth muscle cells (PASMC) are the main effectors of the physiological response(s) induced during or following hypoxic exposure. Endothelial cells, on the other hand, can sense humoral and haemodynamic changes incurred by hypoxia, triggering their production of vasoactive and mitogenic factors that then alter PASMC function and growth. Transmembrane ion flux through channels in the plasma membrane not only modulates excitation-contraction coupling in PASMC, but also regulates cell volume, apoptosis, and proliferation. In this review, we examine the roles of K+ and Ca2+ channels in the pulmonary vasoconstriction and vascular remodeling observed during chronic hypoxia-induced pulmonary hypertension. PMID:16060848
Exercise intolerance in pulmonary hypertension: mechanism, evaluation and clinical implications.

PubMed

Babu, Abraham Samuel; Arena, Ross; Myers, Jonathan; Padmakumar, Ramachandran; Maiya, Arun G; Cahalin, Lawrence P; Waxman, Aaron B; Lavie, Carl J

2016-09-01

Exercise intolerance in pulmonary hypertension (PH) is a major factor affecting activities of daily living and quality of life. Evaluation strategies (i.e., non-invasive and invasive tests) are integral to providing a comprehensive assessment of clinical and functional status. Despite a growing body of literature on the clinical consequences of PH, there are limited studies discussing the contribution of various physiological systems to exercise intolerance in this patient population. This review, through a search of various databases, describes the physiological basis for exercise intolerance across the various PH etiologies, highlights the various exercise evaluation methods and discusses the rationale for exercise training amongst those diagnosed with PH. Expert commentary: With the growing importance of evaluating exercise capacity in PH (class 1, Level C recommendation), understanding why exercise performance is altered in PH is crucial. Thus, the further study is required for better quality evidence in this area.
Improving the clinical assessment of consciousness with advances in electrophysiological and neuroimaging techniques

PubMed Central

2010-01-01

In clinical neurology, a comprehensive understanding of consciousness has been regarded as an abstract concept - best left to philosophers. However, times are changing and the need to clinically assess consciousness is increasingly becoming a real-world, practical challenge. Current methods for evaluating altered levels of consciousness are highly reliant on either behavioural measures or anatomical imaging. While these methods have some utility, estimates of misdiagnosis are worrisome (as high as 43%) - clearly this is a major clinical problem. The solution must involve objective, physiologically based measures that do not rely on behaviour. This paper reviews recent advances in physiologically based measures that enable better evaluation of consciousness states (coma, vegetative state, minimally conscious state, and locked in syndrome). Based on the evidence to-date, electroencephalographic and neuroimaging based assessments of consciousness provide valuable information for evaluation of residual function, formation of differential diagnoses, and estimation of prognosis. PMID:20113490
Oxygen matters: tissue culture oxygen levels affect mitochondrial function and structure as well as responses to HIV viroproteins

PubMed Central

Tiede, L M; Cook, E A; Morsey, B; Fox, H S

2011-01-01

Mitochondrial dysfunction is implicated in a majority of neurodegenerative disorders and much study of neurodegenerative disease is done on cultured neurons. In traditional tissue culture, the oxygen level that cells experience is dramatically higher (21%) than in vivo conditions (1–11%). These differences can alter experimental results, especially, pertaining to mitochondria and oxidative metabolism. Our results show that primary neurons cultured at physiological oxygen levels found in the brain showed higher polarization, lower rates of ROS production, larger mitochondrial networks, greater cytoplasmic fractions of mitochondria and larger mitochondrial perimeters than those cultured at higher oxygen levels. Although neurons cultured in either physiological oxygen or atmospheric oxygen exhibit significant increases in mitochondrial reactive oxygen species (ROS) production when treated with the human immunodeficiency virus (HIV) virotoxin trans-activator of transcription, mitochondria of neurons cultured at physiological oxygen underwent depolarization with dramatically increased cell death, whereas those cultured at atmospheric oxygen became hyperpolarized with no increase in cell death. Studies with a second HIV virotoxin, negative regulation factor (Nef), revealed that Nef treatment also increased mitochondrial ROS production for both the oxygen conditions, but resulted in mitochondrial depolarization and increased death only in neurons cultured in physiological oxygen. These results indicate a role for oxidative metabolism in a mechanism of neurotoxicity during HIV infection and demonstrate the importance of choosing the correct, physiological, culture oxygen in mitochondrial studies performed in neurons. PMID:22190005
Know your neighbor: Microbiota and host epithelial cells interact locally to control intestinal function and physiology.

PubMed

Sommer, Felix; Bäckhed, Fredrik

2016-05-01

Interactions between the host and its associated microbiota differ spatially and the local cross talk determines organ function and physiology. Animals and their organs are not uniform but contain several functional and cellular compartments and gradients. In the intestinal tract, different parts of the gut carry out different functions, tissue structure varies accordingly, epithelial cells are differentially distributed and gradients exist for several physicochemical parameters such as nutrients, pH, or oxygen. Consequently, the microbiota composition also differs along the length of the gut, but also between lumen and mucosa of the same intestinal segment, and even along the crypt-villus axis in the epithelium. Thus, host-microbiota interactions are highly site-specific and the local cross talk determines intestinal function and physiology. Here we review recent advances in our understanding of site-specific host-microbiota interactions and discuss their functional relevance for host physiology. © 2016 WILEY Periodicals, Inc.
Children's patterns of emotional reactivity to conflict as explanatory mechanisms in links between interpartner aggression and child physiological functioning.

PubMed

Davies, Patrick T; Sturge-Apple, Melissa L; Cicchetti, Dante; Manning, Liviah G; Zale, Emily

2009-11-01

This paper examined children's fearful, sad, and angry reactivity to interparental conflict as mediators of associations between their exposure to interparental aggression and physiological functioning. Participants included 200 toddlers and their mothers. Assessments of interparental aggression and children's emotional reactivity were derived from maternal surveys and a semi-structured interview. Cortisol levels and cardiac indices of sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) activity were used to assess toddler physiological functioning. Results indicated that toddler exposure to interparental aggression was associated with greater cortisol levels and PNS activity and diminished SNS activity. Toddler angry emotional reactivity mediated associations between interparental aggression and cortisol and PNS functioning. Fearful emotional reactivity was a mediator of the link between interparental aggression and SNS functioning. The results are interpreted within conceptualizations of how exposure and reactivity to family risk organize individual differences in physiological functioning.
Neuromuscular assessment in elderly workers with and without work related shoulder/neck trouble: the NEW-study design and physiological findings.

PubMed

Sjøgaard, G; Søgaard, K; Hermens, H J; Sandsjö, L; Läubli, T; Thorn, S; Vollenbroek-Hutten, M M R; Sell, L; Christensen, H; Klipstein, A; Kadefors, R; Merletti, R

2006-01-01

Musculoskeletal disorders in the neck and shoulder area are a major occupational concern in the European countries especially among elderly females. The aim was to assess these disorders based on quantitative EMG indicators and functional tests. 252 female computer users (45-68 years) were recruited from four European countries in two contrast groups: (1) 88 neck/shoulder (NS) cases reporting trouble in the neck and/or shoulder region for more than 30 days during the last year, and (2) 164 NS-controls reporting such trouble for no more than 7 days. Questionnaires, functional/clinical tests, and physiological recordings were performed in workplace related field studies. The results showed no differences in anthropometrics but NS-cases reported more strained head positions and more eye problems than controls. The psychosocial working factors were similar, although, NS-controls had slightly better scores on working conditions, general health, and vitality compared to cases. The NS-cases had lower maximal voluntary contraction (MVC) during shoulder elevation (mean (SD) 310 (122) N) compared to the controls (364 (122) N). During 30% MVC electromyography (EMGrms) in the trapezius muscle was lower in NS-cases (194 (105) muV) than in controls (256 (169) muV), while no differences were found regarding endurance time. Estimated conduction velocity was not different between NS-cases and -controls. Four functional computer tests were performed equally well by NS-cases and -controls, and the corresponding EMG variables also did not differ. A major finding in this large-scale epidemiological study is the significantly lower MVC in NS-cases compared with NS-controls together with lower EMGrms value at 30% MVC, while computer tasks were performed at similar relative muscle activation. The study was unable to reveal quantitative EMG indicators and functional tests that could objectively assess disorders in NS-cases.
Maturation status of sarcomere structure and function in human iPSC-derived cardiac myocytes.

PubMed

Bedada, Fikru B; Wheelwright, Matthew; Metzger, Joseph M

2016-07-01

Human heart failure due to myocardial infarction is a major health concern. The paucity of organs for transplantation limits curative approaches for the diseased and failing adult heart. Human induced pluripotent stem cell-derived cardiac myocytes (hiPSC-CMs) have the potential to provide a long-term, viable, regenerative-medicine alternative. Significant progress has been made with regard to efficient cardiac myocyte generation from hiPSCs. However, directing hiPSC-CMs to acquire the physiological structure, gene expression profile and function akin to mature cardiac tissue remains a major obstacle. Thus, hiPSC-CMs have several hurdles to overcome before they find their way into translational medicine. In this review, we address the progress that has been made, the void in knowledge and the challenges that remain. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.
A Systematic Analysis of Candidate Genes Associated with Nicotine Addiction

PubMed Central

Liu, Meng; Li, Xia; Fan, Rui; Liu, Xinhua; Wang, Ju

2015-01-01

Nicotine, as the major psychoactive component of tobacco, has broad physiological effects within the central nervous system, but our understanding of the molecular mechanism underlying its neuronal effects remains incomplete. In this study, we performed a systematic analysis on a set of nicotine addiction-related genes to explore their characteristics at network levels. We found that NAGenes tended to have a more moderate degree and weaker clustering coefficient and to be less central in the network compared to alcohol addiction-related genes or cancer genes. Further, clustering of these genes resulted in six clusters with themes in synaptic transmission, signal transduction, metabolic process, and apoptosis, which provided an intuitional view on the major molecular functions of the genes. Moreover, functional enrichment analysis revealed that neurodevelopment, neurotransmission activity, and metabolism related biological processes were involved in nicotine addiction. In summary, by analyzing the overall characteristics of the nicotine addiction related genes, this study provided valuable information for understanding the molecular mechanisms underlying nicotine addiction. PMID:26097843
Prostaglandins in the kidney: developments since Y2K.

PubMed

Nasrallah, Rania; Clark, Jordan; Hébert, Richard L

2007-10-01

There are five major PGs (prostaglandins/prostanoids) produced from arachidonic acid via the COX (cyclo-oxygenase) pathway: PGE(2), PGI(2) (prostacyclin), PGD(2), PGF(2alpha) and TXA(2) (thromboxane A(2)). They exert many biological effects through specific G-protein-coupled membrane receptors, namely EP (PGE(2) receptor), IP (PGI(2) receptor), DP (PGD(2) receptor), FP (PGF(2alpha) receptor) and TP (TXA(2) receptor) respectively. PGs are implicated in physiological and pathological processes in all major organ systems, including cardiovascular function, gastrointestinal responses, reproductive processes, renal effects etc. This review highlights recent insights into the role of each prostanoid in regulating various aspects of renal function, including haemodynamics, renin secretion, growth responses, tubular transport processes and cell fate. A thorough review of the literature since Y2K (year 2000) is provided, with a general overview of PGs and their synthesis enzymes, and then specific considerations of each PG/prostanoid receptor system in the kidney.
Bordetella pertussis pathogenesis: current and future challenges.

PubMed

Melvin, Jeffrey A; Scheller, Erich V; Miller, Jeff F; Cotter, Peggy A

2014-04-01

Pertussis, also known as whooping cough, has recently re-emerged as a major public health threat despite high levels of vaccination against the aetiological agent Bordetella pertussis. In this Review, we describe the pathogenesis of this disease, with a focus on recent mechanistic insights into B. pertussis virulence-factor function. We also discuss the changing epidemiology of pertussis and the challenges facing vaccine development. Despite decades of research, many aspects of B. pertussis physiology and pathogenesis remain poorly understood. We highlight knowledge gaps that must be addressed to develop improved vaccines and therapeutic strategies.
Bordetella pertussis pathogenesis: current and future challenges

PubMed Central

Melvin, Jeffrey A.; Scheller, Erich V.; Miller, Jeff F.; Cotter, Peggy A.

2014-01-01

Pertussis, or whooping cough, has recently reemerged as a major public health threat despite high levels of vaccination against the etiological agent, Bordetella pertussis. In this Review, we describe the pathogenesis of this disease, with a focus on recent mechanistic insights into virulence factor function. We also discuss the changing epidemiology of pertussis and the challenges of vaccine development. Despite decades of research, many aspects of B. pertussis physiology and pathogenesis remain poorly understood. We highlight knowledge gaps that must be addressed to develop improved vaccines and therapeutic strategies. PMID:24608338
Alteration of human serum albumin binding properties induced by modifications: A review

NASA Astrophysics Data System (ADS)

Maciążek-Jurczyk, Małgorzata; Szkudlarek, Agnieszka; Chudzik, Mariola; Pożycka, Jadwiga; Sułkowska, Anna

2018-01-01

Albumin, a major transporting protein in the blood, is the main target of modification that affects the binding of drugs to Sudlow's site I and II. These modification of serum protein moderates its physiological function, and works as a biomarker of some diseases. The main goal of the paper was to explain the possible alteration of human serum albumin binding properties induced by modifications such as glycation, oxidation and ageing, their origin, methods of evaluation and positive and negative meaning described by significant researchers.
Glycan antagonists and inhibitors: a fount for drug discovery.

PubMed

Brown, Jillian R; Crawford, Brett E; Esko, Jeffrey D

2007-01-01

Glycans, the carbohydrate chains of glycoproteins, proteoglycans, and glycolipids, represent a relatively unexploited area for drug development compared with other macromolecules. This review describes the major classes of glycans synthesized by animal cells, their mode of assembly, and available inhibitors for blocking their biosynthesis and function. Many of these agents have proven useful for studying the biological activities of glycans in isolated cells, during embryological development, and in physiology. Some are being used to develop drugs for treating metabolic disorders, cancer, and infection, suggesting that glycans are excellent targets for future drug development.

Specific Appetite for Carotenoids in a Colorful Bird

PubMed Central

Senar, Juan Carlos; Møller, Anders Pape; Ruiz, Iker; Negro, Juan José; Broggi, Juli; Hohtola, Esa

2010-01-01

Background Since carotenoids have physiological functions necessary for maintaining health, individuals should be selected to actively seek and develop a specific appetite for these compounds. Methodology/Principal Findings Great tits Parus major in a diet choice experiment, both in captivity and the field, preferred carotenoid-enriched diets to control diets. The food items did not differ in any other aspects measured besides carotenoid content. Conclusions/Significance Specific appetite for carotenoids is here demonstrated for the first time, placing these compounds on a par with essential nutrients as sodium or calcium. PMID:20502717
Applications of bioactive material from snakehead fish (Channa striata) for repairing of learning-memory capability and motoric activity: a case study of physiological aging and aging-caused oxidative stress in rats

NASA Astrophysics Data System (ADS)

Sunarno, Sunarno; Muflichatun Mardiati, Siti; Rahadian, Rully

2018-05-01

Physiological aging and aging due to oxidative stress are a major factor cause accelerated brain aging. Aging is characterized by a decrease of brain function of the hippocampus which is linked to the decline in the capability of learning-memory and motoric activity. The objective of this research is to obtain the important information about the mechanisms of brain antiaging associated with the improvement of hippocampus function, which includes aspects of learning-memory capability and motoric activity as well as mitochondrial ultrastructure profile of hippocampus cornu ammonis cells after treated by fish snakehead fish extract. Snakehead fish in Rawa Pening Semarang District allegedly holds the potential of endemic, which contains bioactive antiaging material that can prevent aging or improve the function of the hippocampus. This research has been conducted using a completely randomized design consisting of four treatments with five replications. The treatments were including rats with physiological aging or aging due to oxidative stress which was treated and without treated with meat extract of snakehead fish. The research was divided into two stages, i.e., determining of learning-memory capability, and determining motoric activity. The measured-parameters are time response to find feed, distance travel, time stereotypes, ambulatory time, and resting time. The result showed that the snakehead fish meat extract might improve function hippocampus, both in physiological aging or aging due to oxidative stress. The capability of learning and memory showed that the rats in both conditions of aging after getting treatment of meat extract of snakehead fish could get a feed in the fourth arm maze faster than rats untreated snakehead fish meat extract. Similarly, the measurement of the distance traveled, time stereotypes, ambulatory time, and resting time showed that rats which received treatment of meat extract of snakehead fish were better than the untreated rats. To conclude, the meat extract of snakehead fish can be used as antiaging material to improve the function of the hippocampus, to improve the capability of learning and memory, to improve motoric activity, and to prevent aging. These findings are expected to provide comprehensive information for the development of antiaging research as an effort to improve public health and to improve learning-memory capability and motoric activity.
Language systems in normal and aphasic human subjects: functional imaging studies and inferences from animal studies.

PubMed

Wise, Richard J S

2003-01-01

The old neurological model of language, based on the writings of Broca, Wernicke and Lichtheim in the 19th century, is now undergoing major modifications. Observations on the anatomy and physiology of auditory processing in non-human primates are giving strong indicators as to how speech perception is organised in the human brain. In the light of this knowledge, functional activation studies with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) are achieving a new level of precision in the investigation of language organisation in the human brain, in a manner not possible with observations on patients with aphasic stroke. Although the use of functional imaging to inform methods of improving aphasia rehabilitation remains underdeveloped, there are strong indicators that this methodology will provide the means to research a very imperfectly developed area of therapy.
Palmitoylation as a Functional Regulator of Neurotransmitter Receptors

PubMed Central

Naumenko, Vladimir S.

2018-01-01

The majority of neuronal proteins involved in cellular signaling undergo different posttranslational modifications significantly affecting their functions. One of these modifications is a covalent attachment of a 16-C palmitic acid to one or more cysteine residues (S-palmitoylation) within the target protein. Palmitoylation is a reversible modification, and repeated cycles of palmitoylation/depalmitoylation might be critically involved in the regulation of multiple signaling processes. Palmitoylation also represents a common posttranslational modification of the neurotransmitter receptors, including G protein-coupled receptors (GPCRs) and ligand-gated ion channels (LICs). From the functional point of view, palmitoylation affects a wide span of neurotransmitter receptors activities including their trafficking, sorting, stability, residence lifetime at the cell surface, endocytosis, recycling, and synaptic clustering. This review summarizes the current knowledge on the palmitoylation of neurotransmitter receptors and its role in the regulation of receptors functions as well as in the control of different kinds of physiological and pathological behavior. PMID:29849559
Functional assembly of engineered myocardium by electrical stimulation of cardiac myocytes cultured on scaffolds.

PubMed

Radisic, Milica; Park, Hyoungshin; Shing, Helen; Consi, Thomas; Schoen, Frederick J; Langer, Robert; Freed, Lisa E; Vunjak-Novakovic, Gordana

2004-12-28

The major challenge of tissue engineering is directing the cells to establish the physiological structure and function of the tissue being replaced across different hierarchical scales. To engineer myocardium, biophysical regulation of the cells needs to recapitulate multiple signals present in the native heart. We hypothesized that excitation-contraction coupling, critical for the development and function of a normal heart, determines the development and function of engineered myocardium. To induce synchronous contractions of cultured cardiac constructs, we applied electrical signals designed to mimic those in the native heart. Over only 8 days in vitro, electrical field stimulation induced cell alignment and coupling, increased the amplitude of synchronous construct contractions by a factor of 7, and resulted in a remarkable level of ultrastructural organization. Development of conductive and contractile properties of cardiac constructs was concurrent, with strong dependence on the initiation and duration of electrical stimulation.
Positron Emission Tomography of the Heart

DOE R&D Accomplishments Database

Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

1979-01-01

Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease.
The pathologic physiology of chronic Bright's disease. An exposition of the "intact nephron hypothesis".

PubMed

Bricker, N S; Morrin, P A; Kime, S W

1997-09-01

Clinical and experimental data relating to the functional capacity of the surviving nephrons of the chronically diseased kidney for the most part support the thesis that these nephrons retain their essential functional integrity regardless of the nature of the underlying form of chronic Bright's disease. There are instances in which specific alterations of function correlate with pathologic involvement of a particular site of the nephron but these appear to represent the exceptions, and in general the more advanced the disease becomes, the less evident are the differentiating features. Studies on dogs with unilateral renal disease indicate that the functional capacity of the nephrons of the diseased kidney parallels that of the nephrons of the contralateral normal kidney. These data tend to exclude widespread intrinsic damage to the functioning nephrons by the underlying pathologic processes. From these observations, as well as from certain supporting clinical and experimental observations, it is suggested that the majority of surviving nephrons in the patient with bilateral renal disease similarly are functionally intact. Concepts of the pathologic physiology of the kidney, based on the "intact nephron hypothesis", are presented. Within the framework of this hypothesis it is concluded that (1) the diseased kidney consists of a diminished number of nephrons, most of which retain essentially normal functional abilities; (2) certain of the apparent abnormalities in function in bilateral renal disease may relate to adaptive changes imposed by the decreased nephron population and the attendant derangements in body fluids rather than to structural distortion of nephrons; (3) the over-all flexibility of the diseased kidney decreases as the number of constituent nephrons decreases; but (4) there is an orderly and predictable pattern of excretion for all substances.
Functions and Mechanisms of Sleep

PubMed Central

Zielinski, Mark R.; McKenna, James T.; McCarley, Robert W.

2017-01-01

Sleep is a complex physiological process that is regulated globally, regionally, and locally by both cellular and molecular mechanisms. It occurs to some extent in all animals, although sleep expression in lower animals may be co-extensive with rest. Sleep regulation plays an intrinsic part in many behavioral and physiological functions. Currently, all researchers agree there is no single physiological role sleep serves. Nevertheless, it is quite evident that sleep is essential for many vital functions including development, energy conservation, brain waste clearance, modulation of immune responses, cognition, performance, vigilance, disease, and psychological state. This review details the physiological processes involved in sleep regulation and the possible functions that sleep may serve. This description of the brain circuitry, cell types, and molecules involved in sleep regulation is intended to further the reader’s understanding of the functions of sleep. PMID:28413828
Functional modules, mutational load and human genetic disease.

PubMed

Zaghloul, Norann A; Katsanis, Nicholas

2010-04-01

The ability to generate a massive amount of sequencing and genotyping data is transforming the study of human genetic disorders. Driven by such innovation, it is likely that whole exome and whole-genome resequencing will replace regionally focused approaches for gene discovery and clinical testing in the next few years. However, this opportunity brings a significant interpretative challenge to assigning function and phenotypic variance to common and rare alleles. Understanding the effect of individual mutations in the context of the remaining genomic variation represents a major challenge to our interpretation of disease. Here, we discuss the challenges of assigning mutation functionality and, drawing from the examples of ciliopathies as well as cohesinopathies and channelopathies, discuss possibilities for the functional modularization of the human genome. Functional modularization in addition to the development of physiologically relevant assays to test allele functionality will accelerate our understanding of disease architecture and enable the use of genome-wide sequence data for disease diagnosis and phenotypic prediction in individuals. Copyright 2010 Elsevier Ltd. All rights reserved.
Functional modules, mutational load and human genetic disease

PubMed Central

Zaghloul, Norann A.; Katsanis, Nicholas

2013-01-01

The ability to generate a massive amount of sequencing and genotyping data is transforming the study of human genetic disorders. Driven by such innovation, it is likely that whole exome and whole-genome resequencing will replace regionally focused approaches for gene discovery and clinical testing in the next few years. However, this opportunity brings a significant interpretative challenge to assigning function and phenotypic variance to common and rare alleles. Understanding the effect of individual mutations in the context of the remaining genomic variation represents a major challenge to our interpretation of disease. Here, we discuss the challenges of assigning mutation functionality and, drawing from the examples of ciliopathies as well as cohesinopathies and channelopathies, discuss possibilities for the functional modularization of the human genome. Functional modularization in addition to the development of physiologically-relevant assays to test allele functionality will accelerate our understanding of disease architecture and enable the use of genome-wide sequence data for disease diagnosis and phenotypic prediction in individuals. PMID:20226561
Metabolic, Reproductive, and Neurologic Abnormalities in Agpat1-Null Mice.

PubMed

Agarwal, Anil K; Tunison, Katie; Dalal, Jasbir S; Nagamma, Sneha S; Hamra, F Kent; Sankella, Shireesha; Shao, Xinli; Auchus, Richard J; Garg, Abhimanyu

2017-11-01

Defects in the biosynthesis of phospholipids and neutral lipids are associated with cell membrane dysfunction, disrupted energy metabolism, and diseases including lipodystrophy. In these pathways, the 1-acylglycerol-3-phosphate O-acyltransferase (AGPAT) enzymes transfer a fatty acid to the sn-2 carbon of sn-1-acylglycerol-3-phosphate (lysophosphatidic acid) to form sn-1, 2-acylglycerol-3-phosphate [phosphatidic acid (PA)]. PA is a precursor for key phospholipids and diacylglycerol. AGPAT1 and AGPAT2 are highly homologous isoenzymes that are both expressed in adipocytes. Genetic defects in AGPAT2 cause congenital generalized lipodystrophy, indicating that AGPAT1 cannot compensate for loss of AGPAT2 in adipocytes. To further explore the physiology of AGPAT1, we characterized a loss-of-function mouse model (Agpat1-/-). The majority of Agpat1-/- mice died before weaning and had low body weight and low plasma glucose levels, independent of plasma insulin and glucagon levels, with reduced percentage of body fat but not generalized lipodystrophy. These mice also had decreased hepatic messenger RNA expression of Igf-1 and Foxo1, suggesting a decrease in gluconeogenesis. In male mice, sperm development was impaired, with a late meiotic arrest near the onset of round spermatid production, and gonadotropins were elevated. Female mice showed oligoanovulation yet retained responsiveness to gonadotropins. Agpat1-/- mice also demonstrated abnormal hippocampal neuron development and developed audiogenic seizures. In summary, Agpat1-/- mice developed widespread disturbances of metabolism, sperm development, and neurologic function resulting from disrupted phospholipid homeostasis. AGPAT1 appears to serve important functions in the physiology of multiple organ systems. The Agpat1-deficient mouse provides an important model in which to study the contribution of phospholipid and triacylglycerol synthesis to physiology and diseases. Copyright © 2017 Endocrine Society.
Unraveling Synaptic GCaMP Signals: Differential Excitability and Clearance Mechanisms Underlying Distinct Ca2+ Dynamics in Tonic and Phasic Excitatory, and Aminergic Modulatory Motor Terminals in Drosophila

PubMed Central

Xing, Xiaomin

2018-01-01

Abstract GCaMP is an optogenetic Ca2+ sensor widely used for monitoring neuronal activities but the precise physiological implications of GCaMP signals remain to be further delineated among functionally distinct synapses. The Drosophila neuromuscular junction (NMJ), a powerful genetic system for studying synaptic function and plasticity, consists of tonic and phasic glutamatergic and modulatory aminergic motor terminals of distinct properties. We report a first simultaneous imaging and electric recording study to directly contrast the frequency characteristics of GCaMP signals of the three synapses for physiological implications. Different GCaMP variants were applied in genetic and pharmacological perturbation experiments to examine the Ca2+ influx and clearance processes underlying the GCaMP signal. Distinct mutational and drug effects on GCaMP signals indicate differential roles of Na+ and K+ channels, encoded by genes including paralytic (para), Shaker (Sh), Shab, and ether-a-go-go (eag), in excitability control of different motor terminals. Moreover, the Ca2+ handling properties reflected by the characteristic frequency dependence of the synaptic GCaMP signals were determined to a large extent by differential capacity of mitochondria-powered Ca2+ clearance mechanisms. Simultaneous focal recordings of synaptic activities further revealed that GCaMPs were ineffective in tracking the rapid dynamics of Ca2+ influx that triggers transmitter release, especially during low-frequency activities, but more adequately reflected cytosolic residual Ca2+ accumulation, a major factor governing activity-dependent synaptic plasticity. These results highlight the vast range of GCaMP response patterns in functionally distinct synaptic types and provide relevant information for establishing basic guidelines for the physiological interpretations of presynaptic GCaMP signals from in situ imaging studies. PMID:29464198
Neuroimmunologic aspects of sleep and sleep loss

NASA Technical Reports Server (NTRS)

Rogers, N. L.; Szuba, M. P.; Staab, J. P.; Evans, D. L.; Dinges, D. F.

2001-01-01

The complex and intimate interactions between the sleep and immune systems have been the focus of study for several years. Immune factors, particularly the interleukins, regulate sleep and in turn are altered by sleep and sleep deprivation. The sleep-wake cycle likewise regulates normal functioning of the immune system. Although a large number of studies have focused on the relationship between the immune system and sleep, relatively few studies have examined the effects of sleep deprivation on immune parameters. Studies of sleep deprivation's effects are important for several reasons. First, in the 21st century, various societal pressures require humans to work longer and sleep less. Sleep deprivation is becoming an occupational hazard in many industries. Second, to garner a greater understanding of the regulatory effects of sleep on the immune system, one must understand the consequences of sleep deprivation on the immune system. Significant detrimental effects on immune functioning can be seen after a few days of total sleep deprivation or even several days of partial sleep deprivation. Interestingly, not all of the changes in immune physiology that occur as a result of sleep deprivation appear to be negative. Numerous medical disorders involving the immune system are associated with changes in the sleep-wake physiology--either being caused by sleep dysfunction or being exacerbated by sleep disruption. These disorders include infectious diseases, fibromyalgia, cancers, and major depressive disorder. In this article, we will describe the relationships between sleep physiology and the immune system, in states of health and disease. Interspersed will be proposals for future research that may illuminate the clinical relevance of the relationships between sleeping, sleep loss and immune function in humans. Copyright 2001 by W.B. Saunders Company.
The Application of Programmed Instruction in Fulfilling the Physiology Course Requirements

ERIC Educational Resources Information Center

Stanisavljevic, Jelena; Djuric, Dragan

2013-01-01

The aim of this study is to compare the effectiveness of models of programmed instruction and conventional (informative-illustrative) expository teaching in terms of fulfilling the aims of the course "Human anatomy and physiology" which is included in the physiology programme and designed for undergraduate students majoring in biology…
Dietary Practices, Attitudes, and Physiological Status of Collegiate Freshman Football Players.

ERIC Educational Resources Information Center

Jonnalagadda, Satya S.; Rosenbloom, Christine A.; Skinner, Robert

2001-01-01

Determined the eating habits, attitudes, and physiological status of freshman collegiate football players who completed a nutrition screening survey and provided fasting blood samples and data on height and weight. Results indicated that as a group, there were no major problems in dietary practices and physiological status, though there was room…
Oxygen demand of perfused heart preparations: how electromechanical function and inadequate oxygenation affect physiology and optical measurements.

PubMed

Kuzmiak-Glancy, Sarah; Jaimes, Rafael; Wengrowski, Anastasia M; Kay, Matthew W

2015-06-01

What is the topic of this review? This review discusses how the function and electrophysiology of isolated perfused hearts are affected by oxygenation and energy utilization. The impact of oxygenation on fluorescence measurements in perfused hearts is also discussed. What advances does it highlight? Recent studies have illuminated the inherent differences in electromechanical function, energy utilization rate and oxygen requirements between the primary types of excised heart preparations. A summary and analysis of how these variables affect experimental results are necessary to elevate the physiological relevance of these approaches in order to advance the field of whole-heart research. The ex vivo perfused heart recreates important aspects of in vivo conditions to provide insight into whole-organ function. In this review we discuss multiple types of ex vivo heart preparations, explain how closely each mimic in vivo function, and discuss how changes in electromechanical function and inadequate oxygenation of ex vivo perfused hearts may affect measurements of physiology. Hearts that perform physiological work have high oxygen demand and are likely to experience hypoxia when perfused with a crystalloid perfusate. Adequate myocardial oxygenation is critically important for obtaining physiologically relevant measurements, so when designing experiments the type of ex vivo preparation and the capacity of perfusate to deliver oxygen must be carefully considered. When workload is low, such as during interventions that inhibit contraction, oxygen demand is also low, which could dramatically alter a physiological response to experimental variables. Changes in oxygenation also alter the optical properties of cardiac tissue, an effect that may influence optical signals measured from both endogenous and exogenous fluorophores. Careful consideration of oxygen supply, working condition, and wavelengths used to acquire optical signals is critical for obtaining physiologically relevant measurements during ex vivo perfused heart studies. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.
Topical negative pressure for the treatment of neonatal post-sternotomy wound dehiscence.

PubMed

Hardwicke, J; Richards, H; Jagadeesan, J; Jones, T; Lester, R

2012-01-01

The use of topical negative pressure (TNP) dressings for sternal wound dehiscence or mediastinitis in the neonatal population is rare. The majority of case reports have focused on wound healing as an endpoint and have not discussed the physiological advantage that TNP dressings may impart with regard to sternal stabilisation, improved respiratory function and early weaning from mechanical ventilation. We present a case of the use of TNP in neonatal post-sternotomy wound dehiscence and mediastinitis, from a UK perspective, with an emphasis on wound healing and physiological optimisation. As well as an improvement in sternal wound healing due to the local effects of the TNP system, serial arterial blood gas analysis revealed a significant improvement in systemic physiological parameters, including a reduction in pCO(2) in the period (days 20-31) after application of TNP (p<0.0001) compared to the period before where simple occlusive dressings were applied. Hydrogen ion concentration also significantly reduced in this period (p=0.0058). The use of the TNP system in association with systemic antibiotics successfully treated the mediastinitis. A sealed, controlled wound environment also allowed ease of nursing and an expedited return to care by the parents. We would recommend the consideration of TNP dressings in similar cases of neonatal and paediatric sternal wound dehiscence. Not only do we observe the local effects of improved wound healing, the systemic effects of improved lung function are also valuable in the early management of such complex cases.
Progress in Integrative Biomaterial Systems to Approach Three-Dimensional Cell Mechanotransduction

PubMed Central

Zhang, Ying; Liao, Kin; Li, Chuan; Lai, Alvin C.K.; Foo, Ji-Jinn

2017-01-01

Mechanotransduction between cells and the extracellular matrix regulates major cellular functions in physiological and pathological situations. The effect of mechanical cues on biochemical signaling triggered by cell–matrix and cell–cell interactions on model biomimetic surfaces has been extensively investigated by a combination of fabrication, biophysical, and biological methods. To simulate the in vivo physiological microenvironment in vitro, three dimensional (3D) microstructures with tailored bio-functionality have been fabricated on substrates of various materials. However, less attention has been paid to the design of 3D biomaterial systems with geometric variances, such as the possession of precise micro-features and/or bio-sensing elements for probing the mechanical responses of cells to the external microenvironment. Such precisely engineered 3D model experimental platforms pave the way for studying the mechanotransduction of multicellular aggregates under controlled geometric and mechanical parameters. Concurrently with the progress in 3D biomaterial fabrication, cell traction force microscopy (CTFM) developed in the field of cell biophysics has emerged as a highly sensitive technique for probing the mechanical stresses exerted by cells onto the opposing deformable surface. In the current work, we first review the recent advances in the fabrication of 3D micropatterned biomaterials which enable the seamless integration with experimental cell mechanics in a controlled 3D microenvironment. Then, we discuss the role of collective cell–cell interactions in the mechanotransduction of engineered tissue equivalents determined by such integrative biomaterial systems under simulated physiological conditions. PMID:28952551
Murine Electrophysiological Models of Cardiac Arrhythmogenesis

PubMed Central

2016-01-01

Cardiac arrhythmias can follow disruption of the normal cellular electrophysiological processes underlying excitable activity and their tissue propagation as coherent wavefronts from the primary sinoatrial node pacemaker, through the atria, conducting structures and ventricular myocardium. These physiological events are driven by interacting, voltage-dependent, processes of activation, inactivation, and recovery in the ion channels present in cardiomyocyte membranes. Generation and conduction of these events are further modulated by intracellular Ca2+ homeostasis, and metabolic and structural change. This review describes experimental studies on murine models for known clinical arrhythmic conditions in which these mechanisms were modified by genetic, physiological, or pharmacological manipulation. These exemplars yielded molecular, physiological, and structural phenotypes often directly translatable to their corresponding clinical conditions, which could be investigated at the molecular, cellular, tissue, organ, and whole animal levels. Arrhythmogenesis could be explored during normal pacing activity, regular stimulation, following imposed extra-stimuli, or during progressively incremented steady pacing frequencies. Arrhythmic substrate was identified with temporal and spatial functional heterogeneities predisposing to reentrant excitation phenomena. These could arise from abnormalities in cardiac pacing function, tissue electrical connectivity, and cellular excitation and recovery. Triggering events during or following recovery from action potential excitation could thereby lead to sustained arrhythmia. These surface membrane processes were modified by alterations in cellular Ca2+ homeostasis and energetics, as well as cellular and tissue structural change. Study of murine systems thus offers major insights into both our understanding of normal cardiac activity and its propagation, and their relationship to mechanisms generating clinical arrhythmias. PMID:27974512
Environmental physiology of the mangrove rivulus, Kryptolebias marmoratus, a cutaneously breathing fish that survives for weeks out of water.

PubMed

Wright, Patricia A

2012-12-01

The mangrove rivulus (Kryptolebias marmoratus) is an excellent model species for understanding the physiological mechanisms that fish use in coping with extreme environmental conditions, particularly cutaneous exchange during prolonged exposure to air. Their ability to self-fertilize and produce highly homozygous lineages provides the potential for examining environmental influences on structures and related functions without the complications of genetic variation. Over the past 10 years or so, we have gained a broader understanding of the mechanisms K. marmoratus use to maintain homeostasis when out of water for days to weeks. Gaseous exchange occurs across the skin, as dramatic remodeling of the gill reduces its effective surface area for exchange. Ionoregulation and osmoregulation are maintained in air by exchanging Na(+), Cl(-), and H(2)O across skin that contains a rich population of ionocytes. Ammonia excretion occurs in part by cutaneous NH(3) volatilization facilitated by ammonia transporters on the surface of the epidermis. Finally, new evidence indicates that cutaneous angiogenesis occurs when K. marmoratus are emersed for a week, suggesting a higher rate of blood flow to surface vessels. Taken together, these and other findings demonstrate that the skin of K. marmoratus takes on all the major functions attributed to fish gills, allowing them to move between aquatic and terrestrial environments with ease. Future studies should focus on variation in response to environmental changes between homozygous lineages to identify the genetic underpinnings of physiological responses.

Environmental Physiology of the Mangrove Rivulus, Kryptolebias marmoratus, A Cutaneously Breathing Fish That Survives for Weeks Out of Water

PubMed Central

Wright, Patricia A.

2012-01-01

The mangrove rivulus (Kryptolebias marmoratus) is an excellent model species for understanding the physiological mechanisms that fish use in coping with extreme environmental conditions, particularly cutaneous exchange during prolonged exposure to air. Their ability to self-fertilize and produce highly homozygous lineages provides the potential for examining environmental influences on structures and related functions without the complications of genetic variation. Over the past 10 years or so, we have gained a broader understanding of the mechanisms K. marmoratus use to maintain homeostasis when out of water for days to weeks. Gaseous exchange occurs across the skin, as dramatic remodeling of the gill reduces its effective surface area for exchange. Ionoregulation and osmoregulation are maintained in air by exchanging Na+, Cl−, and H2O across skin that contains a rich population of ionocytes. Ammonia excretion occurs in part by cutaneous NH3 volatilization facilitated by ammonia transporters on the surface of the epidermis. Finally, new evidence indicates that cutaneous angiogenesis occurs when K. marmoratus are emersed for a week, suggesting a higher rate of blood flow to surface vessels. Taken together, these and other findings demonstrate that the skin of K. marmoratus takes on all the major functions attributed to fish gills, allowing them to move between aquatic and terrestrial environments with ease. Future studies should focus on variation in response to environmental changes between homozygous lineages to identify the genetic underpinnings of physiological responses. PMID:22693260
Coil-to-coil physiological noise correlations and their impact on functional MRI time-series signal-to-noise ratio.

PubMed

Triantafyllou, Christina; Polimeni, Jonathan R; Keil, Boris; Wald, Lawrence L

2016-12-01

Physiological nuisance fluctuations ("physiological noise") are a major contribution to the time-series signal-to-noise ratio (tSNR) of functional imaging. While thermal noise correlations between array coil elements have a well-characterized effect on the image Signal to Noise Ratio (SNR 0 ), the element-to-element covariance matrix of the time-series fluctuations has not yet been analyzed. We examine this effect with a goal of ultimately improving the combination of multichannel array data. We extend the theoretical relationship between tSNR and SNR 0 to include a time-series noise covariance matrix Ψ t , distinct from the thermal noise covariance matrix Ψ 0 , and compare its structure to Ψ 0 and the signal coupling matrix SS H formed from the signal intensity vectors S. Inclusion of the measured time-series noise covariance matrix into the model relating tSNR and SNR 0 improves the fit of experimental multichannel data and is shown to be distinct from Ψ 0 or SS H . Time-series noise covariances in array coils are found to differ from Ψ 0 and more surprisingly, from the signal coupling matrix SS H . Correct characterization of the time-series noise has implications for the analysis of time-series data and for improving the coil element combination process. Magn Reson Med 76:1708-1719, 2016. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.
Dysphagia in Infants with Single Ventricle Anatomy Following Stage 1 Palliation: Physiologic Correlates and Response to Treatment

PubMed Central

McGrattan, Katlyn Elizabeth; McGhee, Heather; DeToma, Allan; Hill, Elizabeth G.; Zyblewski, Sinai C.; Lefton-Greif, Maureen; Halstead, Lucinda; Bradley, Scott M.; Martin-Harris, Bonnie

2017-01-01

Background Deficits in swallowing physiology are a leading morbidity for infants with functional single ventricles and systemic outflow tract obstruction following stage 1 palliation. Despite the high prevalence of this condition, the underlying deficits that cause this post-operative impairment remain poorly understood. Objective Identify the physiologic correlates of dysphagia in infants with functional single ventricles and systemic outflow tract obstruction following stage 1 palliative surgery. Methods Postoperative fiberoptic laryngoscopies and videofluoroscopic swallow studies (VFSS) were conducted sequentially on infants with functional single ventricles following stage 1 palliative surgery. Infants were dichotomized as having normal or impaired laryngeal function based on laryngoscopy findings. VFSS were evaluated frame-by-frame using a scale that quantifies performance within 11 components of swallowing physiology. Physiologic attributes within each component were categorized as high functioning or low functioning based on their ability to support milk ingestion without bolus airway entry. Results Thirty-six infants (25 male) were included in the investigation. Twenty-four underwent the Norwood procedure and twelve underwent the Hybrid procedure. Low function physiologic patterns were observed within multiple swallowing components during the ingestion of thin barium as characterized by ≥ 4 sucks per swallow (36%), initiation of pharyngeal swallow below the level of the valleculae (83%), and incomplete late laryngeal vestibular closure (56%) at the height of the swallow. Swallowing deficits contributed to aspiration in 50% of infants. Although nectar thick liquids reduced the rate of aspiration (p=0.006), aspiration rates remained high (27%). No differences in rates of penetration or aspiration were observed between infants with normal and impaired laryngeal function. Conclusions Deficits in swallowing physiology contribute to penetration and aspiration following stage 1 palliation among infants with normal and impaired laryngeal function. Although thickened liquids may improve airway protection for select infants, they may inhibit their ability to extract the bolus and meet nutritional needs. PMID:28244680
Dysphagia in infants with single ventricle anatomy following stage 1 palliation: Physiologic correlates and response to treatment.

PubMed

McGrattan, Katlyn Elizabeth; McGhee, Heather; DeToma, Allan; Hill, Elizabeth G; Zyblewski, Sinai C; Lefton-Greif, Maureen; Halstead, Lucinda; Bradley, Scott M; Martin-Harris, Bonnie

2017-05-01

Deficits in swallowing physiology are a leading morbidity for infants with functional single ventricles and systemic outflow tract obstruction following stage 1 palliation. Despite the high prevalence of this condition, the underlying deficits that cause this post-operative impairment remain poorly understood. Identify the physiologic correlates of dysphagia in infants with functional single ventricles and systemic outflow tract obstruction following stage 1 palliative surgery. Postoperative fiberoptic laryngoscopies and videofluoroscopic swallow studies (VFSS) were conducted sequentially on infants with functional single ventricles following stage 1 palliative surgery. Infants were dichotomized as having normal or impaired laryngeal function based on laryngoscopy findings. VFSS were evaluated frame-by-frame using a scale that quantifies performance within 11 components of swallowing physiology. Physiologic attributes within each component were categorized as high functioning or low functioning based on their ability to support milk ingestion without bolus airway entry. Thirty-six infants (25 male) were included in the investigation. Twenty-four underwent the Norwood procedure and twelve underwent the Hybrid procedure. Low function physiologic patterns were observed within multiple swallowing components during the ingestion of thin barium as characterized by ≥4 sucks per swallow (36%), initiation of pharyngeal swallow below the level of the valleculae (83%), and incomplete late laryngeal vestibular closure (56%) at the height of the swallow. Swallowing deficits contributed to aspiration in 50% of infants. Although nectar thick liquids reduced the rate of aspiration (P = .006), aspiration rates remained high (27%). No differences in rates of penetration or aspiration were observed between infants with normal and impaired laryngeal function. Deficits in swallowing physiology contribute to penetration and aspiration following stage 1 palliation among infants with normal and impaired laryngeal function. Although thickened liquids may improve airway protection for select infants, they may inhibit their ability to extract the bolus and meet nutritional needs. © 2017 Wiley Periodicals, Inc.
Failure to Find Executive Function Deficits Following One Night’s Total Sleep-Deprivation in University Students under Naturalistic Conditions

PubMed Central

Pace-Schott, Edward F.; Hutcherson, Cendri A.; Bemporad, Brenda; Morgan, Alexandra; Kumar, Arjun; Hobson, J. Allan; Stickgold, Robert

2018-01-01

Young adult male students participated in a naturalistic, group-design experiment to ascertain the effects of one night’s total sleep deprivation (TSD) on performance of diverse executive function tasks presented as an extended, multi-task battery. On the majority of component tasks in this battery, performance has been reported to be impaired following one night’s TSD when tasks are administered in isolation. However, subjects sleep deprived 35–39 hours showed few performance deficits among tests in this battery when compared with non sleep-deprived controls. Sleep-deprived subjects showed only poorer recognition memory and overconfidence in incorrect temporal judgments. Behavioral and physiological adaptation to chronically sleep-restricting lifestyles may confer resistance to the cognitive effects of sleep deprivation in high-functioning young adults. PMID:19568965
RING-type E3 ligases: Master manipulators of E2 ubiquitin-conjugating enzymes and ubiquitination

PubMed Central

Metzger, Meredith B.; Pruneda, Jonathan N.; Klevit, Rachel E.; Weissman, Allan M.

2013-01-01

RING finger domain and RING finger-like ubiquitin ligases (E3s), such as U-box proteins, constitute the vast majority of known E3s. RING-type E3s function together with ubiquitin-conjugating enzymes (E2s) to mediate ubiquitination and are implicated in numerous cellular processes. In part because of their importance in human physiology and disease, these proteins and their cellular functions represent an intense area of study. Here we review recent advances in RING-type E3 recognition of substrates, their cellular regulation, and their varied architecture. Additionally, recent structural insights into RING-type E3 function, with a focus on important interactions with E2s and ubiquitin, are reviewed. This article is part of a Special Issue entitled: Ubiquitin-Proteasome System. PMID:23747565
Cellular Metabolic and Autophagic Pathways: Traffic Control by Redox Signaling

PubMed Central

Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

2013-01-01

It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality, and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function. PMID:23702245
Research advances in major cereal crops for adaptation to abiotic stresses

PubMed Central

Maiti, RK; Satya, Pratik

2014-01-01

With devastating increase in population there is a great necessity to increase crop productivity of staple crops but the productivity is greatly affected by various abiotic stress factors such as drought, salinity. An attempt has been made a brief account on abiotic stress resistance of major cereal crops viz. In spite of good successes obtained on physiological and use molecular biology, the benefits of this high cost technology are beyond the reach of developing countries. This review discusses several morphological, anatomical, physiological, biochemical and molecular mechanisms of major cereal crops related to the adaptation of these crop to abiotic stress factors. It discusses the effect of abiotic stresses on physiological processes such as flowering, grain filling and maturation and plant metabolisms viz. photosynthesis, enzyme activity, mineral nutrition, and respiration. Though significant progress has been attained on the physiological, biochemical basis of resistance to abiotic stress factors, very little progress has been achieved to increase productivity under sustainable agriculture. Therefore, there is a great necessity of inter-disciplinary research to address this issue and to evolve efficient technology and its transfer to the farmers’ fields. PMID:25523172
Research advances in major cereal crops for adaptation to abiotic stresses.

PubMed

Maiti, R K; Satya, Pratik

2014-01-01

With devastating increase in population there is a great necessity to increase crop productivity of staple crops but the productivity is greatly affected by various abiotic stress factors such as drought, salinity. An attempt has been made a brief account on abiotic stress resistance of major cereal crops viz. In spite of good successes obtained on physiological and use molecular biology, the benefits of this high cost technology are beyond the reach of developing countries. This review discusses several morphological, anatomical, physiological, biochemical and molecular mechanisms of major cereal crops related to the adaptation of these crop to abiotic stress factors. It discusses the effect of abiotic stresses on physiological processes such as flowering, grain filling and maturation and plant metabolisms viz. photosynthesis, enzyme activity, mineral nutrition, and respiration. Though significant progress has been attained on the physiological, biochemical basis of resistance to abiotic stress factors, very little progress has been achieved to increase productivity under sustainable agriculture. Therefore, there is a great necessity of inter-disciplinary research to address this issue and to evolve efficient technology and its transfer to the farmers' fields.
Improvement in the physiological function and standing stability based on kinect multimedia for older people

PubMed Central

Chen, Chih-Chen

2016-01-01

[Purpose] The increase in the Taiwanese older population is associated with age-related inconveniences. Finding adequate and simple physical activities to help the older people maintaining their physiological function and preventing them from falls has become an urgent social issue. [Subjects and Methods] This study aimed to design a virtual exercise training game suitable for Taiwanese older people. This system will allow for the maintenance of the physiological function and standing stability through physical exercise, while using a virtual reality game. The participants can easily exercise in a carefree, interactive environment. This study will use Kinect for Windows for physical movement detection and Unity software for virtual world development. [Results] Group A and B subjects were involved in the exercise training method of Kinect interactive multimedia for 12 weeks. The results showed that the functional reach test and the unipedal stance test improved significantly. [Conclusion] The physiological function and standing stability of the group A subjects were examined at six weeks post training. The results showed that these parameters remained constant. This proved that the proposed system provide substantial support toward the preservation of the Taiwanese older people’ physiological function and standing stability. PMID:27190480
Improvement in the physiological function and standing stability based on kinect multimedia for older people.

PubMed

Chen, Chih-Chen

2016-04-01

[Purpose] The increase in the Taiwanese older population is associated with age-related inconveniences. Finding adequate and simple physical activities to help the older people maintaining their physiological function and preventing them from falls has become an urgent social issue. [Subjects and Methods] This study aimed to design a virtual exercise training game suitable for Taiwanese older people. This system will allow for the maintenance of the physiological function and standing stability through physical exercise, while using a virtual reality game. The participants can easily exercise in a carefree, interactive environment. This study will use Kinect for Windows for physical movement detection and Unity software for virtual world development. [Results] Group A and B subjects were involved in the exercise training method of Kinect interactive multimedia for 12 weeks. The results showed that the functional reach test and the unipedal stance test improved significantly. [Conclusion] The physiological function and standing stability of the group A subjects were examined at six weeks post training. The results showed that these parameters remained constant. This proved that the proposed system provide substantial support toward the preservation of the Taiwanese older people' physiological function and standing stability.
Permeabilization of brain tissue in situ enables multiregion analysis of mitochondrial function in a single mouse brain.

PubMed

Herbst, Eric A F; Holloway, Graham P

2015-02-15

Mitochondrial function in the brain is traditionally assessed through analysing respiration in isolated mitochondria, a technique that possesses significant tissue and time requirements while also disrupting the cooperative mitochondrial reticulum. We permeabilized brain tissue in situ to permit analysis of mitochondrial respiration with the native mitochondrial morphology intact, removing the need for isolation time and minimizing tissue requirements to ∼2 mg wet weight. The permeabilized brain technique was validated against the traditional method of isolated mitochondria and was then further applied to assess regional variation in the mouse brain with ischaemia-reperfusion injuries. A transgenic mouse model overexpressing catalase within mitochondria was applied to show the contribution of mitochondrial reactive oxygen species to ischaemia-reperfusion injuries in different brain regions. This technique enhances the accessibility of addressing physiological questions in small brain regions and in applying transgenic mouse models to assess mechanisms regulating mitochondrial function in health and disease. Mitochondria function as the core energy providers in the brain and symptoms of neurodegenerative diseases are often attributed to their dysregulation. Assessing mitochondrial function is classically performed in isolated mitochondria; however, this process requires significant isolation time, demand for abundant tissue and disruption of the cooperative mitochondrial reticulum, all of which reduce reliability when attempting to assess in vivo mitochondrial bioenergetics. Here we introduce a method that advances the assessment of mitochondrial respiration in the brain by permeabilizing existing brain tissue to grant direct access to the mitochondrial reticulum in situ. The permeabilized brain preparation allows for instant analysis of mitochondrial function with unaltered mitochondrial morphology using significantly small sample sizes (∼2 mg), which permits the analysis of mitochondrial function in multiple subregions within a single mouse brain. Here this technique was applied to assess regional variation in brain mitochondrial function with acute ischaemia-reperfusion injuries and to determine the role of reactive oxygen species in exacerbating dysfunction through the application of a transgenic mouse model overexpressing catalase within mitochondria. Through creating accessibility to small regions for the investigation of mitochondrial function, the permeabilized brain preparation enhances the capacity for examining regional differences in mitochondrial regulation within the brain, as the majority of genetic models used for unique approaches exist in the mouse model. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.
Vestibular Function Research (VFR) experiment. Phase B: Design definition study

NASA Technical Reports Server (NTRS)

1978-01-01

The Vestibular Functions Research (VFR) Experiment was established to investigate the neurosensory and related physiological processes believed to be associated with the space flight nausea syndrome and to develop logical means for its prediction, prevention and treatment. The VFR Project consists of ground and spaceflight experimentation using frogs as specimens. The phase B Preliminary Design Study provided for the preliminary design of the experiment hardware, preparation of performance and hardware specification and a Phase C/D development plan, establishment of STS (Space Transportation System) interfaces and mission operations, and the study of a variety of hardware, experiment and mission options. The study consist of three major tasks: (1) mission mode trade-off; (2) conceptual design; and (3) preliminary design.
Finite element models of the human shoulder complex: a review of their clinical implications and modelling techniques.

PubMed

Zheng, Manxu; Zou, Zhenmin; Bartolo, Paulo Jorge Da Silva; Peach, Chris; Ren, Lei

2017-02-01

The human shoulder is a complicated musculoskeletal structure and is a perfect compromise between mobility and stability. The objective of this paper is to provide a thorough review of previous finite element (FE) studies in biomechanics of the human shoulder complex. Those FE studies to investigate shoulder biomechanics have been reviewed according to the physiological and clinical problems addressed: glenohumeral joint stability, rotator cuff tears, joint capsular and labral defects and shoulder arthroplasty. The major findings, limitations, potential clinical applications and modelling techniques of those FE studies are critically discussed. The main challenges faced in order to accurately represent the realistic physiological functions of the shoulder mechanism in FE simulations involve (1) subject-specific representation of the anisotropic nonhomogeneous material properties of the shoulder tissues in both healthy and pathological conditions; (2) definition of boundary and loading conditions based on individualised physiological data; (3) more comprehensive modelling describing the whole shoulder complex including appropriate three-dimensional (3D) representation of all major shoulder hard tissues and soft tissues and their delicate interactions; (4) rigorous in vivo experimental validation of FE simulation results. Fully validated shoulder FE models would greatly enhance our understanding of the aetiology of shoulder disorders, and hence facilitate the development of more efficient clinical diagnoses, non-surgical and surgical treatments, as well as shoulder orthotics and prosthetics. © 2016 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd. © 2016 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons Ltd.
Computational tools for comparative phenomics; the role and promise of ontologies

PubMed Central

Gkoutos, Georgios V.; Schofield, Paul N.; Hoehndorf, Robert

2012-01-01

A major aim of the biological sciences is to gain an understanding of human physiology and disease. One important step towards such a goal is the discovery of the function of genes that will lead to better understanding of the physiology and pathophysiology of organisms ultimately providing better understanding, diagnosis, and therapy. Our increasing ability to phenotypically characterise genetic variants of model organisms coupled with systematic and hypothesis-driven mutagenesis is resulting in a wealth of information that could potentially provide insight to the functions of all genes in an organism. The challenge we are now facing is to develop computational methods that can integrate and analyse such data. The introduction of formal ontologies that make their semantics explicit and accessible to automated reasoning promises the tantalizing possibility of standardizing biomedical knowledge allowing for novel, powerful queries that bridge multiple domains, disciplines, species and levels of granularity. We review recent computational approaches that facilitate the integration of experimental data from model organisms with clinical observations in humans. These methods foster novel cross species analysis approaches, thereby enabling comparative phenomics and leading to the potential of translating basic discoveries from the model systems into diagnostic and therapeutic advances at the clinical level. PMID:22814867
The Endocannabinoid System in the Retina: From Physiology to Practical and Therapeutic Applications.

PubMed

Schwitzer, Thomas; Schwan, Raymund; Angioi-Duprez, Karine; Giersch, Anne; Laprevote, Vincent

2016-01-01

Cannabis is one of the most prevalent drugs used in industrialized countries. The main effects of Cannabis are mediated by two major exogenous cannabinoids: ∆9-tetrahydroxycannabinol and cannabidiol. They act on specific endocannabinoid receptors, especially types 1 and 2. Mammals are endowed with a functional cannabinoid system including cannabinoid receptors, ligands, and enzymes. This endocannabinoid signaling pathway is involved in both physiological and pathophysiological conditions with a main role in the biology of the central nervous system. As the retina is a part of the central nervous system due to its embryonic origin, we aim at providing the relevance of studying the endocannabinoid system in the retina. Here, we review the distribution of the cannabinoid receptors, ligands, and enzymes in the retina and focus on the role of the cannabinoid system in retinal neurobiology. This review describes the presence of the cannabinoid system in critical stages of retinal processing and its broad involvement in retinal neurotransmission, neuroplasticity, and neuroprotection. Accordingly, we support the use of synthetic cannabinoids as new neuroprotective drugs to prevent and treat retinal diseases. Finally, we argue for the relevance of functional retinal measures in cannabis users to evaluate the impact of cannabis use on human retinal processing.
Segregation of Form, Color, Movement, and Depth: Anatomy, Physiology, and Perception

NASA Astrophysics Data System (ADS)

Livingstone, Margaret; Hubel, David

1988-05-01

Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their selectivity for color, stereopsis, movement, and orientation. The pathways selective for form and color seem to be derived mainly from the parvocellular geniculate subdivisions, the depth- and movement-selective components from the magnocellular. At lower levels, in the retina and in the geniculate, cells in these two subdivisions differ in their color selectivity, contrast sensitivity, temporal properties, and spatial resolution. These major differences in the properties of cells at lower levels in each of the subdivisions led to the prediction that different visual functions, such as color, depth, movement, and form perception, should exhibit corresponding differences. Human perceptual experiments are remarkably consistent with these predictions. Moreover, perceptual experiments can be designed to ask which subdivisions of the system are responsible for particular visual abilities, such as figure/ground discrimination or perception of depth from perspective or relative movement--functions that might be difficult to deduce from single-cell response properties.
The Alzheimer's Amyloid-Degrading Peptidase, Neprilysin: Can We Control It?

PubMed Central

Nalivaeva, N. N.; Belyaev, N. D.; Zhuravin, I. A.; Turner, A. J.

2012-01-01

The amyloid cascade hypothesis of Alzheimer's disease (AD) postulates that accumulation in the brain of amyloid β-peptide (Aβ) is the primary trigger for neuronal loss specific to this pathology. In healthy brain, Aβ levels are regulated by a dynamic equilibrium between Aβ release from the amyloid precursor protein (APP) and its removal by perivascular drainage or by amyloid-degrading enzymes (ADEs). During the last decade, the ADE family was fast growing, and currently it embraces more than 20 members. There are solid data supporting involvement of each of them in Aβ clearance but a zinc metallopeptidase neprilysin (NEP) is considered as a major ADE. NEP plays an important role in brain function due to its role in terminating neuropeptide signalling and its decrease during ageing or after such pathologies as hypoxia or ischemia contribute significantly to the development of AD pathology. The recently discovered mechanism of epigenetic regulation of NEP by the APP intracellular domain (AICD) opens new avenues for its therapeutic manipulation and raises hope for developing preventive strategies in AD. However, consideration needs to be given to the diverse physiological roles of NEP. This paper critically evaluates general biochemical and physiological functions of NEP and their therapeutic relevance. PMID:22900228
High-throughput sequencing reveals circular substrates for an archaeal RNA ligase

PubMed Central

Becker, Hubert F.; Héliou, Alice; Djaout, Kamel; Lestini, Roxane; Regnier, Mireille; Myllykallio, Hannu

2017-01-01

ABSTRACT It is only recently that the abundant presence of circular RNAs (circRNAs) in all kingdoms of Life, including the hyperthermophilic archaeon Pyrococcus abyssi, has emerged. This led us to investigate the physiologic significance of a previously observed weak intramolecular ligation activity of Pab1020 RNA ligase. Here we demonstrate that this enzyme, despite sharing significant sequence similarity with DNA ligases, is indeed an RNA-specific polynucleotide ligase efficiently acting on physiologically significant substrates. Using a combination of RNA immunoprecipitation assays and RNA-seq, our genome-wide studies revealed 133 individual circRNA loci in P. abyssi. The large majority of these loci interacted with Pab1020 in cells and circularization of selected C/D Box and 5S rRNA transcripts was confirmed biochemically. Altogether these studies revealed that Pab1020 is required for RNA circularization. Our results further suggest the functional speciation of an ancestral NTase domain and/or DNA ligase toward RNA ligase activity and prompt for further characterization of the widespread functions of circular RNAs in prokaryotes. Detailed insight into the cellular substrates of Pab1020 may facilitate the development of new biotechnological applications e.g. in ligation of preadenylated adaptors to RNA molecules. PMID:28277897
Physiological principles of vestibular function on earth and in space

NASA Technical Reports Server (NTRS)

Minor, L. B.

1998-01-01

Physiological mechanisms underlying vestibular function have important implications for our ability to understand, predict, and modify balance processes during and after spaceflight. The microgravity environment of space provides many unique opportunities for studying the effects of changes in gravitoinertial force on structure and function of the vestibular system. Investigations of basic vestibular physiology and of changes in reflexes occurring as a consequence of exposure to microgravity have important implications for diagnosis and treatment of vestibular disorders in human beings. This report reviews physiological principles underlying control of vestibular processes on earth and in space. Information is presented from a functional perspective with emphasis on signals arising from labyrinthine receptors. Changes induced by microgravity in linear acceleration detected by the vestibulo-ocular reflexes. Alterations of the functional requirements for postural control in space are described. Areas of direct correlation between studies of vestibular reflexes in microgravity and vestibular disorders in human beings are discussed.

Metabolomic profiles indicate distinct physiological pathways affected by two loci with major divergent effect on Bos taurus growth and lipid deposition.

PubMed

Weikard, Rosemarie; Altmaier, Elisabeth; Suhre, Karsten; Weinberger, Klaus M; Hammon, Harald M; Albrecht, Elke; Setoguchi, Kouji; Takasuga, Akiko; Kühn, Christa

2010-10-01

Identifying trait-associated genetic variation offers new prospects to reveal novel physiological pathways modulating complex traits. Taking advantage of a unique animal model, we identified the I442M mutation in the non-SMC condensin I complex, subunit G (NCAPG) gene and the Q204X mutation in the growth differentiation factor 8 (GDF8) gene as substantial modulators of pre- and/or postnatal growth in cattle. In a combined metabolomic and genotype association approach, which is the first respective study in livestock, we surveyed the specific physiological background of the effects of both loci on body-mass gain and lipid deposition. Our data provided confirming evidence from two historically and geographically distant cattle populations that the onset of puberty is the key interval of divergent growth. The locus-specific metabolic patterns obtained from monitoring 201 plasma metabolites at puberty mirror the particular NCAPG I442M and GDF8 Q204X effects and represent biosignatures of divergent physiological pathways potentially modulating effects on proportional and disproportional growth, respectively. While the NCAPG I442M mutation affected the arginine metabolism, the 204X allele in the GDF8 gene predominantly raised the carnitine level and had concordant effects on glycerophosphatidylcholines and sphingomyelins. Our study provides a conclusive link between the well-described growth-regulating functions of arginine metabolism and the previously unknown specific physiological role of the NCAPG protein in mammalian metabolism. Owing to the confirmed effect of the NCAPG/LCORL locus on human height in genome-wide association studies, the results obtained for bovine NCAPG might add valuable, comparative information on the physiological background of genetically determined divergent mammalian growth.
The Functional Task Test (FTT): An Interdisciplinary Testing Protocol to Investigate the Factors Underlying Changes in Astronaut Functional Performance

NASA Technical Reports Server (NTRS)

Bloomberg, J. J.; Lawrence, E. L.; Arzeno, N. M.; Buxton, R. E.; Feiveson, A. H.; Kofman, I. S.; Lee, S. M. C.; Mulavara, A. P.; Peters, B. T.; Platts. S. H.;

2011-01-01

Exposure to space flight causes adaptations in multiple physiological systems including changes in sensorimotor, cardiovascular, and neuromuscular systems. These changes may affect a crewmember s ability to perform critical mission tasks immediately after landing on a planetary surface. The overall goal of this project is to determine the effects of space flight on functional tests that are representative of high priority exploration mission tasks and to identify the key underlying physiological factors that contribute to decrements in performance. To achieve this goal we developed an interdisciplinary testing protocol (Functional Task Test, FTT) that evaluates both astronaut functional performance and related physiological changes. Functional tests include ladder climbing, hatch opening, jump down, manual manipulation of objects and tool use, seat egress and obstacle avoidance, recovery from a fall and object translation tasks. Physiological measures include assessments of postural and gait control, dynamic visual acuity, fine motor control, plasma volume, orthostatic intolerance, upper- and lower-body muscle strength, power, endurance, control, and neuromuscular drive. Crewmembers perform this integrated test protocol before and after short (Shuttle) and long-duration (ISS) space flight. Data are collected on two sessions before flight, on landing day (Shuttle only) and 1, 6 and 30 days after landing. Preliminary results from both Shuttle and ISS crewmembers indicate decrement in performance of the functional tasks after both short and long-duration space flight. On-going data collection continues to improve the statistical power required to map changes in functional task performance to alterations in physiological systems. The information obtained from this study will be used to design and implement countermeasures that specifically target the physiological systems most responsible for the altered functional performance associated with space flight.

Hypnosis in the Treatment of Major Depression: An Analysis of Heart Rate Variability.

PubMed

Chen, Xiuwen; Yang, Rongqian; Ge, Lulu; Luo, Jie; Lv, Ruixue

2017-01-01

Hypnosis is an adjuvant treatment of major depression (MD). Heart rate variability (HRV) can assess the autonomic nervous system, which is associated with MD, and HRV is decreased in MD patients. There is a lack of research on HRV changes before, during, and after the use of hypnosis in MD patients. A total of 21 MD patients participated in this study, and 5-minute electrocardiograms were recorded before, during, and after hypnosis. Compared with the prehypnotic condition, HRV parameters significantly (p < .01) increased in the hypnotic and posthypnotic conditions. The results suggest that hypnosis treatment should bring some functional improvement to the autonomic nervous system. HRV is potentially a useful tool that quantifies the physiological impact of hypnosis treatment in MD patients.
A Program for Iron Economy during Deficiency Targets Specific Fe Proteins.

PubMed

Hantzis, Laura J; Kroh, Gretchen E; Jahn, Courtney E; Cantrell, Michael; Peers, Graham; Pilon, Marinus; Ravet, Karl

2018-01-01

Iron (Fe) is an essential element for plants, utilized in nearly every cellular process. Because the adjustment of uptake under Fe limitation cannot satisfy all demands, plants need to acclimate their physiology and biochemistry, especially in their chloroplasts, which have a high demand for Fe. To investigate if a program exists for the utilization of Fe under deficiency, we analyzed how hydroponically grown Arabidopsis ( Arabidopsis thaliana ) adjusts its physiology and Fe protein composition in vegetative photosynthetic tissue during Fe deficiency. Fe deficiency first affected photosynthetic electron transport with concomitant reductions in carbon assimilation and biomass production when effects on respiration were not yet significant. Photosynthetic electron transport function and protein levels of Fe-dependent enzymes were fully recovered upon Fe resupply, indicating that the Fe depletion stress did not cause irreversible secondary damage. At the protein level, ferredoxin, the cytochrome- b 6 f complex, and Fe-containing enzymes of the plastid sulfur assimilation pathway were major targets of Fe deficiency, whereas other Fe-dependent functions were relatively less affected. In coordination, SufA and SufB, two proteins of the plastid Fe-sulfur cofactor assembly pathway, were also diminished early by Fe depletion. Iron depletion reduced mRNA levels for the majority of the affected proteins, indicating that loss of enzyme was not just due to lack of Fe cofactors. SufB and ferredoxin were early targets of transcript down-regulation. The data reveal a hierarchy for Fe utilization in photosynthetic tissue and indicate that a program is in place to acclimate to impending Fe deficiency. © 2018 American Society of Plant Biologists. All Rights Reserved.
Role of leptin in energy homeostasis in humans

PubMed Central

Rosenbaum, Michael; Leibel, Rudolph L

2015-01-01

The hyperphagia, low sympathetic nervous system tone, and decreased circulating concentrations of bioactive thyroid hormones that are common to states of congenital leptin deficiency and hypoleptinemia following and during weight loss suggest that the major physiological function of leptin is to signal states of negative energy balance and decreased energy stores. In weight-reduced humans, these phenotypes together with pronounced hypometabolism and increased parasympathetic nervous system tone create the optimal circumstance for weight regain. Based on the weight loss induced by leptin administration in states of leptin deficiency (obese) and observed similarity of phenotypes in states of congenital and dietary-induced states of hypoleptinemia (reduced obese), it has been suggested that exogenous leptin could potentially be useful in initiating, promoting, and sustaining weight reduction. However, the responses of human beings to exogenous leptin administration are dependent not only on extant energy stores but also on energy balance. Leptin administration to humans at usual weight has little, if any, effect on body weight while leptin administration during weight loss mitigates hunger, especially if given in supraphysiological doses during severe caloric restriction. Leptin repletion is most effective following weight loss by dietary restriction. In this state of weight stability but reduced energy stores, leptin at least partially reverses many of the metabolic, autonomic, neuroendocrine, and behavioral adaptations that favor weight regain. The major physiological function of leptin is to signal states of negative energy balance and decreased energy stores. Leptin, and pharmacotherapies affecting leptin signaling pathways, is likely to be most useful in sustaining weight loss. PMID:25063755
Differential and Conditional Activation of PKC-Isoforms Dictates Cardiac Adaptation during Physiological to Pathological Hypertrophy

PubMed Central

Naskar, Shaon; Datta, Kaberi; Mitra, Arkadeep; Pathak, Kanchan; Datta, Ritwik; Bansal, Trisha; Sarkar, Sagartirtha

2014-01-01

A cardiac hypertrophy is defined as an increase in heart mass which may either be beneficial (physiological hypertrophy) or detrimental (pathological hypertrophy). This study was undertaken to establish the role of different protein kinase-C (PKC) isoforms in the regulation of cardiac adaptation during two types of cardiac hypertrophy. Phosphorylation of specific PKC-isoforms and expression of their downstream proteins were studied during physiological and pathological hypertrophy in 24 week male Balb/c mice (Mus musculus) models, by reverse transcriptase-PCR, western blot analysis and M-mode echocardiography for cardiac function analysis. PKC-δ was significantly induced during pathological hypertrophy while PKC-α was exclusively activated during physiological hypertrophy in our study. PKC-δ activation during pathological hypertrophy resulted in cardiomyocyte apoptosis leading to compromised cardiac function and on the other hand, activation of PKC-α during physiological hypertrophy promoted cardiomyocyte growth but down regulated cellular apoptotic load resulting in improved cardiac function. Reversal in PKC-isoform with induced activation of PKC-δ and simultaneous inhibition of phospho-PKC-α resulted in an efficient myocardium to deteriorate considerably resulting in compromised cardiac function during physiological hypertrophy via augmentation of apoptotic and fibrotic load. This is the first report where PKC-α and -δ have been shown to play crucial role in cardiac adaptation during physiological and pathological hypertrophy respectively thereby rendering compromised cardiac function to an otherwise efficient heart by conditional reversal of their activation. PMID:25116170
Physiology in Medicine: neuromuscular consequences of diabetic neuropathy.

PubMed

Allen, Matti D; Doherty, Timothy J; Rice, Charles L; Kimpinski, Kurt

2016-07-01

Diabetic polyneuropathy (DPN) refers to peripheral nerve dysfunction as a complication of diabetes mellitus. This condition is relatively common and is likely a result of vascular and/or metabolic disturbances related to diabetes. In the early or less severe stages of DPN it typically results in sensory impairments but can eventually lead to major dysfunction of the neuromuscular system. Some of these impairments may include muscle atrophy and weakness, slowing of muscle contraction, and loss of power and endurance. Combined with sensory deficits these changes in the motor system can contribute to decreased functional capacity, impaired mobility, altered gait, and increased fall risk. There is no pharmacological disease-modifying therapy available for DPN and the mainstay of treatment is linked to treating the diabetes itself and revolves around strict glycemic control. Exercise therapy (including aerobic, strength, or balance training-based exercise) appears to be a promising preventative and treatment strategy for patients with DPN and those at risk. The goal of this Physiology in Medicine article is to highlight important and overlooked dysfunction of the neuromuscular system as a result of DPN with an emphasis on the physiologic basis for that dysfunction. Additionally, we sought to provide information that clinicians can use when following patients with diabetes or DPN including support for the inclusion of exercise-based therapy as an effective, accessible, and inexpensive form of treatment. Copyright © 2016 the American Physiological Society.
Dissection of K+ currents in Caenorhabditis elegans muscle cells by genetics and RNA interference

PubMed Central

Santi, C. M.; Yuan, A.; Fawcett, G.; Wang, Z.-W.; Butler, A.; Nonet, M. L.; Wei, A.; Rojas, P.; Salkoff, L.

2003-01-01

GFP-promoter experiments have previously shown that at least nine genes encoding potassium channel subunits are expressed in Caenorhabditis elegans muscle. By using genetic, RNA interference, and physiological techniques we revealed the molecular identity of the major components of the outward K+ currents in body wall muscle cells in culture. We found that under physiological conditions, outward current is dominated by the products of only two genes, Shaker (Kv1) and Shal (Kv4), both expressing voltage-dependent potassium channels. Other channels may be held in reserve to respond to particular circumstances. Because GFP-promoter experiments indicated that slo-2 expression is prominent, we created a deletion mutant to identify the SLO-2 current in vivo. In both whole-cell and single-channel modes, in vivo SLO-2 channels were active only when intracellular Ca2+ and Cl- were raised above normal physiological conditions, as occurs during hypoxia. Under such conditions, SLO-2 is the largest outward current, contributing up to 87% of the total current. Other channels are present in muscle, but our results suggest that they are unlikely to contribute a large outward component under physiological conditions. However, they, too, may contribute currents conditional on other factors. Hence, the picture that emerges is of a complex membrane with a small number of household conductances functioning under normal circumstances, but with additional conductances that are activated during unusual circumstances. PMID:14612577
The Physiology Undergraduate Major in the University of Arizona College of Medicine: Past, Present, and Future

ERIC Educational Resources Information Center

Henriksen, Erik J.; Atwater, Anne E.; Delamere, Nicholas A.; Dantzler, William H.

2011-01-01

The American Physiological Society (APS) and APS Council encourage the teaching of physiology at the undergraduate, graduate, and medical school levels to support the continued prominence of this area of science. One area identified by the APS Council that is of particular importance for the development of future physiologists (the…
Unperturbed vs. post-transplantation hematopoiesis: both in vivo but different

PubMed Central

Busch, Katrin; Rodewald, Hans-Reimer

2016-01-01

Purpose of review Hematopoietic stem cell (HSC) transplantation has yielded tremendous information on experimental properties of HSCs. Yet, it remains unclear whether transplantation reflects the physiology of hematopoiesis. A limitation is the difficulty in accessing HSC functions without isolation, in-vitro manipulation and readout for potential. New genetic fate mapping and clonal marking techniques now shed light on hematopoiesis under physiological conditions. Recent findings Transposon-based genetic marks were introduced across the entire hematopoietic system to follow the clonal dynamics of these tags over time. A polyclonal source downstream from stem cells was found responsible for the production of at least granulocytes. In independent experiments, HSCs were genetically marked in adult mice, and the kinetics of label emergence throughout the system was followed over time. These experiments uncovered that during physiological steady-state hematopoiesis large numbers of HSCs yield differentiated progeny. Individual HSCs were active only rarely, indicating their very slow periodicity of differentiation rather than quiescence. Summary Noninvasive genetic experiments in mice have identified a major role of stem and progenitor cells downstream from HSCs as drivers of adult hematopoiesis, and revealed that post-transplantation hematopoiesis differs quantitatively from normal steady-state hematopoiesis. PMID:27213498
New modes of assisted mechanical ventilation.

PubMed

Suarez-Sipmann, F

2014-05-01

Recent major advances in mechanical ventilation have resulted in new exciting modes of assisted ventilation. Compared to traditional ventilation modes such as assisted-controlled ventilation or pressure support ventilation, these new modes offer a number of physiological advantages derived from the improved patient control over the ventilator. By implementing advanced closed-loop control systems and using information on lung mechanics, respiratory muscle function and respiratory drive, these modes are specifically designed to improve patient-ventilator synchrony and reduce the work of breathing. Depending on their specific operational characteristics, these modes can assist spontaneous breathing efforts synchronically in time and magnitude, adapt to changing patient demands, implement automated weaning protocols, and introduce a more physiological variability in the breathing pattern. Clinicians have now the possibility to individualize and optimize ventilatory assistance during the complex transition from fully controlled to spontaneous assisted ventilation. The growing evidence of the physiological and clinical benefits of these new modes is favoring their progressive introduction into clinical practice. Future clinical trials should improve our understanding of these modes and help determine whether the claimed benefits result in better outcomes. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.
Hemodynamic Instability during Dialysis: The Potential Role of Intradialytic Exercise

PubMed Central

Horton, Elizabeth Jane; Renshaw, Derek; Jimenez, Alofonso; Krishnan, Nithya

2018-01-01

Acute haemodynamic instability is a natural consequence of disordered cardiovascular physiology during haemodialysis (HD). Prevalence of intradialytic hypotension (IDH) can be as high as 20–30%, contributing to subclinical, transient myocardial ischemia. In the long term, this results in progressive, maladaptive cardiac remodeling and impairment of left ventricular function. This is thought to be a major contributor to increased cardiovascular mortality in end stage renal disease (ESRD). Medical strategies to acutely attenuate haemodynamic instability during HD are suboptimal. Whilst a programme of intradialytic exercise training appears to facilitate numerous chronic adaptations, little is known of the acute physiological response to this type of exercise. In particular, the potential for intradialytic exercise to acutely stabilise cardiovascular hemodynamics, thus preventing IDH and myocardial ischemia, has not been explored. This narrative review aims to summarise the characteristics and causes of acute haemodynamic instability during HD, with an overview of current medical therapies to treat IDH. Moreover, we discuss the acute physiological response to intradialytic exercise with a view to determining the potential for this nonmedical intervention to stabilise cardiovascular haemodynamics during HD, improve coronary perfusion, and reduce cardiovascular morbidity and mortality in ESRD. PMID:29682559
Physiological adaptation to the humid tropics with special reference to the West African Dwarf (WAD) goat.

PubMed

Daramola, J O; Adeloye, A A

2009-10-01

West African Dwarf (WAD) goats are widely distributed in the subhumid and humid zones of Africa but are particularly associated with less favourable environments. Adaptive features such as feeding behaviour, efficiency of feed use and disease tolerance enable WAD goats to thrive on natural resources left untouched by other domestic ruminants. In marginal environments this goat remains the only domestic species that is able to survive. Among its physiological features small body size and low metabolic requirements are important traits that enable the animal to minimize its requirements in area or season where food sources are limited in quality and quantity. Specialized feeding behaviour and an efficient digestive system enable the animal to maximize food intake. Coat colour plays an important role in the evolved adaptation of this goat type. Reproductive fitness as manifested by prolific breeding is a major factor of adaptation. Defence mechanisms against infectious agents enable this type to thrive well in the hot humid tropics. The mechanisms involved in the regulation of these physiological functions of WAD goat are discussed. An understanding of these mechanisms could result in the development of improved techniques for enhancing goat productivity in humid environments.
Evaluating Heavy Metal Stress Levels in Rice Based on Remote Sensing Phenology.

PubMed

Liu, Tianjiao; Liu, Xiangnan; Liu, Meiling; Wu, Ling

2018-03-14

Heavy metal pollution of croplands is a major environmental problem worldwide. Methods for accurately and quickly monitoring heavy metal stress have important practical significance. Many studies have explored heavy metal stress in rice in relation to physiological function or physiological factors, but few studies have considered phenology, which can be sensitive to heavy metal stress. In this study, we used an integrated Normalized Difference Vegetation Index (NDVI) time-series image set to extract remote sensing phenology. A phenological indicator relatively sensitive to heavy metal stress was chosen from the obtained phenological periods and phenological parameters. The Dry Weight of Roots (WRT), which directly affected by heavy metal stress, was simulated by the World Food Study (WOFOST) model; then, a feature space based on the phenological indicator and WRT was established for monitoring heavy metal stress. The results indicated that the feature space can distinguish the heavy metal stress levels in rice, with accuracy greater than 95% for distinguishing the severe stress level. This finding provides scientific evidence for combining rice phenology and physiological characteristics in time and space, and the method is useful to monitor heavy metal stress in rice.
Children’s Patterns of Emotional Reactivity to Conflict as Explanatory Mechanisms in Links Between Interpartner Aggression and Child Physiological Functioning

PubMed Central

Davies, Patrick T.; Sturge-Apple, Melissa L.; Cicchetti, Dante; Manning, Liviah G.; Zale, Emily

2009-01-01

Background This paper examined children’s fearful, sad, and angry reactivity to interparental conflict as mediators of associations between their exposure to interparental aggression and physiological functioning. Methods Participants included 200 toddlers and their mothers. Assessments of interparental aggression and children’s emotional reactivity were derived from maternal surveys and a semi-structured interview. Cortisol levels and cardiac indices of sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) activity were used to assess toddler physiological functioning. Results Results indicated that toddler exposure to interparental aggression was associated with greater cortisol levels and PNS activity and diminished SNS activity. Toddler angry emotional reactivity mediated associations between interparental aggression and cortisol and PNS functioning. Fearful emotional reactivity was a mediator of the link between interparental aggression and SNS functioning. Conclusions The results are interpreted within conceptualizations of how exposure and reactivity to family risk organizing individual differences in physiological functioning. PMID:19744183
A new class of methods for functional connectivity estimation

NASA Astrophysics Data System (ADS)

Lin, Wutu

Measuring functional connectivity from neural recordings is important in understanding processing in cortical networks. The covariance-based methods are the current golden standard for functional connectivity estimation. However, the link between the pair-wise correlations and the physiological connections inside the neural network is unclear. Therefore, the power of inferring physiological basis from functional connectivity estimation is limited. To build a stronger tie and better understand the relationship between functional connectivity and physiological neural network, we need (1) a realistic model to simulate different types of neural recordings with known ground truth for benchmarking; (2) a new functional connectivity method that produce estimations closely reflecting the physiological basis. In this thesis, (1) I tune a spiking neural network model to match with human sleep EEG data, (2) introduce a new class of methods for estimating connectivity from different kinds of neural signals and provide theory proof for its superiority, (3) apply it to simulated fMRI data as an application.
The Effects of Stress on Cognitive Aging, Physiology and Emotion (ESCAPE) Project.

PubMed

Scott, Stacey B; Graham-Engeland, Jennifer E; Engeland, Christopher G; Smyth, Joshua M; Almeida, David M; Katz, Mindy J; Lipton, Richard B; Mogle, Jacqueline A; Munoz, Elizabeth; Ram, Nilam; Sliwinski, Martin J

2015-07-03

Despite evidence that psychological stress is an important risk factor for age-related cognitive loss, little research has directly evaluated psychological and physiological mediators of the relationship between stressful experiences and cognitive function. A key objective of the ESCAPE (Effects of Stress on Cognitive Aging, Physiology, and Emotion) project is to evaluate whether engaging in stress-related unconstructive repetitive thought (URT) is a pathway through which stressful experiences negatively affect cognitive health over the short- and long-term. Over the short-term, we hypothesize that engaging in URT will deplete attentional resources and result in worse cognitive performance in daily life. Over the long-term, we expect that the effects of chronic stress, from repeated exposure to stressors and regular engagement in URT, will be apparent in dysregulated hypothalamic-pituitary-adrenal (HPA) axis function and inflammation. Over time, stress-related physiological dysregulation will result in accelerated cognitive decline. This study utilizes a prospective longitudinal measurement-burst design. A systematic probability sample of participants aged 25 to 65 is recruited from residents of the Bronx, NY. Consenting participants complete a baseline assessment and follow-up waves at 9, 18, and 27 months post-baseline. At each wave, participants complete a 14 day measurement burst of brief surveys and cognitive assessments delivered via study smartphones during daily life. Participants provide saliva samples four times each day for five days during the measurement burst and fasting blood samples at the end of each burst from which cortisol and dehydroepiandrosterone sulfate (DHEAS), circulating inflammatory markers, and stimulated inflammatory responses to lipopolysaccharide in whole blood are determined. This study takes a multi-pronged approach to assessing stress (i.e., early adversity, chronic strains, major events, daily hassles), psychological mediators (e.g., URT), biological mechanisms (i.e., HPA function, inflammation) and outcomes across different time-scales (i.e., momentary cognitive performance, cognitive decline across years). The systematic probability sample is locally representative and can be compared with national norms on key markers of health and well-being. The findings will improve our understanding of how environmental, psychological, and physiological stress-related influences accumulate to affect cognitive health and identify potential targets (e.g., URT, inflammation) for prevention and intervention promoting cognitive health.
Microglia across the lifespan: from origin to function in brain development, plasticity and cognition

PubMed Central

Savage, Julie C.; Hui, Chin Wai; Bisht, Kanchan

2016-01-01

Abstract Microglia are the only immune cells that permanently reside in the central nervous system (CNS) alongside neurons and other types of glial cells. The past decade has witnessed a revolution in our understanding of their roles during normal physiological conditions. Cutting‐edge techniques revealed that these resident immune cells are critical for proper brain development, actively maintain health in the mature brain, and rapidly adapt their function to physiological or pathophysiological needs. In this review, we highlight recent studies on microglial origin (from the embryonic yolk sac) and the factors regulating their differentiation and homeostasis upon brain invasion. Elegant experiments tracking microglia in the CNS allowed studies of their unique roles compared with other types of resident macrophages. Here we review the emerging roles of microglia in brain development, plasticity and cognition, and discuss the implications of the depletion or dysfunction of microglia for our understanding of disease pathogenesis. Immune activation, inflammation and various other conditions resulting in undesirable microglial activity at different stages of life could severely impair learning, memory and other essential cognitive functions. The diversity of microglial phenotypes across the lifespan, between compartments of the CNS, and sexes, as well as their crosstalk with the body and external environment, is also emphasised. Understanding what defines particular microglial phenotypes is of major importance for future development of innovative therapies controlling their effector functions, with consequences for cognition across chronic stress, ageing, neuropsychiatric and neurological diseases. PMID:27104646
Purine ionotropic (P2X) receptors.

PubMed

Köles, L; Fürst, S; Illes, P

2007-01-01

Purinergic signaling is involved in the proper functioning of virtually all organs of the body. Although in some cases purines have a major influence on physiological functions (e.g. thrombocyte aggregation), more often they are just background modulators contributing to fine tuning of biological events. However, under pathological conditions, when a huge amount of adenosine 5'-triphosphate (ATP) can reach the extracellular space, their significance is increasing. ATP and its various degradation products activate membrane receptors divided into two main classes: the metabotropic P2Y and the ionotropic P2X family. This latter group, the purine ionotropic receptor, is the object of this review. After providing a description about the distribution and functional properties of P2X receptors in the body, their pharmacology will be summarized. In the second part of this review, the role of purines in those organ systems and body functions will be highlighted, where the (patho)physiological role of P2X receptors has been suggested or is even well established. Besides the regulation of organ systems, for instance in the cardiovascular, respiratory, genitourinary or gastrointestinal system, some special issues will also be discussed, such as the role of P2X receptors in pain, tumors, central nervous system (CNS) injury and embryonic development. Several examples will indicate that purine ionotropic receptors might serve as attractive targets for pharmacological interventions in various diseases, and that selective ligands for these receptors will probably constitute important future therapeutic tools in humans.
Aquaporins in the eye: Expression, function, and roles in ocular disease☆

PubMed Central

Schey, Kevin L.; Wang, Zhen; Wenke, Jamie L.; Qi, Ying

2015-01-01

Background All thirteen known mammalian aquaporins have been detected in the eye. Moreover, aquaporins have been identified as playing essential roles in ocular functions ranging from maintenance of lens and corneal transparency to production of aqueous humor to maintenance of cellular homeostasis and regulation of signal transduction in the retina. Scope of review This review summarizes the expression and known functions of ocular aquaporins and discusses their known and potential roles in ocular diseases. Major conclusions Aquaporins play essential roles in all ocular tissues. Remarkably, not all aquaporin function as a water permeable channel and the functions of many aquaporins in ocular tissues remain unknown. Given their vital roles in maintaining ocular function and their roles in disease, aquaporins represent potential targets for future therapeutic development. General significance Since aquaporins play key roles in ocular physiology, an understanding of these functions is important to improving ocular health and treating diseases of the eye. It is likely that future therapies for ocular diseases will rely on modulation of aquaporin expression and/or function. This article is part of a Special Issue entitled Aquaporins. PMID:24184915

Inactivation of thyA in Staphylococcus aureus Attenuates Virulence and Has a Strong Impact on Metabolism and Virulence Gene Expression

PubMed Central

Kriegeskorte, Andre; Block, Desiree; Drescher, Mike; Windmüller, Nadine; Mellmann, Alexander; Baum, Cathrin; Neumann, Claudia; Lorè, Nicola Ivan; Bragonzi, Alessandra; Liebau, Eva; Hertel, Patrick; Seggewiss, Jochen; Becker, Karsten; Proctor, Richard A.; Peters, Georg

2014-01-01

ABSTRACT Staphylococcus aureus thymidine-dependent small-colony variants (TD-SCVs) are frequently isolated from patients with chronic S. aureus infections after long-term treatment with trimethoprim-sulfamethoxazole (TMP-SMX). While it has been shown that TD-SCVs were associated with mutations in thymidylate synthase (TS; thyA), the impact of such mutations on protein function is lacking. In this study, we showed that mutations in thyA were leading to inactivity of TS proteins, and TS inactivity led to tremendous impact on S. aureus physiology and virulence. Whole DNA microarray analysis of the constructed ΔthyA mutant identified severe alterations compared to the wild type. Important virulence regulators (agr, arlRS, sarA) and major virulence determinants (hla, hlb, sspAB, and geh) were downregulated, while genes important for colonization (fnbA, fnbB, spa, clfB, sdrC, and sdrD) were upregulated. The expression of genes involved in pyrimidine and purine metabolism and nucleotide interconversion changed significantly. NupC was identified as a major nucleoside transporter, which supported growth of the mutant during TMP-SMX exposure by uptake of extracellular thymidine. The ΔthyA mutant was strongly attenuated in virulence models, including a Caenorhabditis elegans killing model and an acute pneumonia mouse model. This study identified inactivation of TS as the molecular basis of clinical TD-SCV and showed that thyA activity has a major role for S. aureus virulence and physiology. PMID:25073642
Long-term neural and physiological phenotyping of a single human

PubMed Central

Poldrack, Russell A.; Laumann, Timothy O.; Koyejo, Oluwasanmi; Gregory, Brenda; Hover, Ashleigh; Chen, Mei-Yen; Gorgolewski, Krzysztof J.; Luci, Jeffrey; Joo, Sung Jun; Boyd, Ryan L.; Hunicke-Smith, Scott; Simpson, Zack Booth; Caven, Thomas; Sochat, Vanessa; Shine, James M.; Gordon, Evan; Snyder, Abraham Z.; Adeyemo, Babatunde; Petersen, Steven E.; Glahn, David C.; Reese Mckay, D.; Curran, Joanne E.; Göring, Harald H. H.; Carless, Melanie A.; Blangero, John; Dougherty, Robert; Leemans, Alexander; Handwerker, Daniel A.; Frick, Laurie; Marcotte, Edward M.; Mumford, Jeanette A.

2015-01-01

Psychiatric disorders are characterized by major fluctuations in psychological function over the course of weeks and months, but the dynamic characteristics of brain function over this timescale in healthy individuals are unknown. Here, as a proof of concept to address this question, we present the MyConnectome project. An intensive phenome-wide assessment of a single human was performed over a period of 18 months, including functional and structural brain connectivity using magnetic resonance imaging, psychological function and physical health, gene expression and metabolomics. A reproducible analysis workflow is provided, along with open access to the data and an online browser for results. We demonstrate dynamic changes in brain connectivity over the timescales of days to months, and relations between brain connectivity, gene expression and metabolites. This resource can serve as a testbed to study the joint dynamics of human brain and metabolic function over time, an approach that is critical for the development of precision medicine strategies for brain disorders. PMID:26648521
Widespread immunological functions of mast cells: fact or fiction?

PubMed

Rodewald, Hans-Reimer; Feyerabend, Thorsten B

2012-07-27

Immunological functions of mast cells are currently considered to be much broader than the original role of mast cells in IgE-driven allergic disease. The spectrum of proposed mast cell functions includes areas as diverse as the regulation of innate and adaptive immune responses, protective immunity against viral, microbial, and parasitic pathogens, autoimmunity, tolerance to graft rejection, promotion of or protection from cancer, wound healing, angiogenesis, cardiovascular diseases, diabetes, obesity, and others. The vast majority of in vivo mast cell data have been based on mast cell-deficient Kit mutant mice. However, work in new mouse mutants with unperturbed Kit function, which have a surprisingly normal immune system, has failed to corroborate some key immunological aspects, formerly attributed to mast cells. Here, we consider the implications of these recent developments for the state of the field as well as for future work, aiming at deciphering the physiological functions of mast cells. Copyright © 2012 Elsevier Inc. All rights reserved.
Pituitary adenylate cyclase-activating polypeptide: a novel peptide with protean implications.

PubMed

Pisegna, Joseph R; Oh, David S

2007-02-01

The purpose of this review is to highlight the importance of pituitary adenylate cyclase-activating polypeptide in physiological processes and to describe how this peptide is becoming increasingly recognized as having a major role in the body. Since its discovery in 1989, investigators have sought to determine the site of biological activity and the function of pituitary adenylate cyclase-activating polypeptide in maintaining homeostasis. Since its discovery, pituitary adenylate cyclase-activating polypeptide appears to play an important role in the regulation of processes within the central nervous system and gastrointestinal tract, as well in reproductive biology. Pituitary adenylate cyclase-activating polypeptide has been shown to regulate tumor cell growth and to regulate immune function through its effects on T lympocytes. These discoveries suggest the importance of pituitary adenylate cyclase-activating polypeptide in neuronal development, neuronal function, gastrointestinal tract function and reproduction. Future studies will examine more closely the role of pituitary adenylate cyclase-activating polypeptide in regulation of malignantly transformed cells, as well as in regulation of immune function.
Relaxin-like peptides in male reproduction - a human perspective.

PubMed

Ivell, Richard; Agoulnik, Alexander I; Anand-Ivell, Ravinder

2017-05-01

The relaxin family of peptide hormones and their cognate GPCRs are becoming physiologically well-characterized in the cardiovascular system and particularly in female reproductive processes. Much less is known about the physiology and pharmacology of these peptides in male reproduction, particularly as regards humans. H2-relaxin is involved in prostate function and growth, while insulin-like peptide 3 (INSL3) is a major product of the testicular Leydig cells and, in the adult, appears to modulate steroidogenesis and germ cell survival. In the fetus, INSL3 is a key hormone expressed shortly after sex determination and is responsible for the first transabdominal phase of testicular descent. Importantly, INSL3 is becoming a very useful constitutive biomarker reflecting both fetal and post-natal development. Nothing is known about roles for INSL4 in male reproduction and only very little about relaxin-3, which is mostly considered as a brain peptide, or INSL5. The former is expressed at very low levels in the testes, but has no known physiology there, whereas the INSL5 knockout mouse does exhibit a testicular phenotype with mild effects on spermatogenesis, probably due to a disruption of glucose homeostasis. INSL6 is a major product of male germ cells, although it is relatively unexplored with regard to its physiology or pharmacology, except that in mice disruption of the INSL6 gene leads to a disruption of spermatogenesis. Clinically, relaxin analogues may be useful in the control of prostate cancer, and both relaxin and INSL3 have been considered as sperm adjuvants for in vitro fertilization. This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc. © 2016 The British Pharmacological Society.
Functional dissection of NEAT1 using genome editing reveals substantial localization of the NEAT1_1 isoform outside paraspeckles

PubMed Central

Li, Ruohan; Harvey, Alan R.; Hodgetts, Stuart I.

2017-01-01

Large numbers of long noncoding RNAs have been discovered in recent years, but only a few have been characterized. NEAT1 (nuclear paraspeckle assembly transcript 1) is a mammalian long noncoding RNA that is important for the reproductive physiology of mice, cancer development, and the formation of subnuclear bodies termed paraspeckles. The two major isoforms of NEAT1 (3.7 kb NEAT1_1 and 23 kb NEAT1_2 in human) are generated from a common promoter and are produced through the use of alternative transcription termination sites. This gene structure has made the functional relationship between the two isoforms difficult to dissect. Here we used CRISPR-Cas9 genome editing to create several different cell lines: total NEAT1 knockout cells, cells that only express the short form NEAT1_1, and cells with twofold more NEAT1_2. Using these reagents, we obtained evidence that NEAT1_1 is not a major component of paraspeckles. In addition, our data suggest NEAT1_1 localizes in numerous nonparaspeckle foci we termed “microspeckles,” which may carry paraspeckle-independent functions. This study highlights the complexity of lncRNA and showcases how genome editing tools are useful in dissecting the structural and functional roles of overlapping transcripts. PMID:28325845
How can the study of physiological reactivity contribute to our understanding of adversity and resilience processes in development?

PubMed

Obradović, Jelena

2012-05-01

The focus of this article is to present current progress in understanding the interplay among adversity, physiological sensitivity to context, and adaptive functioning, with an emphasis on implications and future directions for resilience researchers. It includes a review of current literature that demonstrates (a) links between various levels of adversity exposure and variability in physiological reactivity, (b) how the interplay between children's physiological reactivity and different sources of risk and adversity relates to variability in adaptive functioning, and (c) various approaches for capturing a more dynamic nature of physiological reactivity and related processes. Throughout, important conceptual and empirical issues are highlighted.
Melatonin: Nature's most versatile biological signal?

PubMed

Pandi-Perumal, S R; Srinivasan, V; Maestroni, G J M; Cardinali, D P; Poeggeler, B; Hardeland, R

2006-07-01

Melatonin is a ubiquitous molecule and widely distributed in nature, with functional activity occurring in unicellular organisms, plants, fungi and animals. In most vertebrates, including humans, melatonin is synthesized primarily in the pineal gland and is regulated by the environmental light/dark cycle via the suprachiasmatic nucleus. Pinealocytes function as 'neuroendocrine transducers' to secrete melatonin during the dark phase of the light/dark cycle and, consequently, melatonin is often called the 'hormone of darkness'. Melatonin is principally secreted at night and is centrally involved in sleep regulation, as well as in a number of other cyclical bodily activities. Melatonin is exclusively involved in signaling the 'time of day' and 'time of year' (hence considered to help both clock and calendar functions) to all tissues and is thus considered to be the body's chronological pacemaker or 'Zeitgeber'. Synthesis of melatonin also occurs in other areas of the body, including the retina, the gastrointestinal tract, skin, bone marrow and in lymphocytes, from which it may influence other physiological functions through paracrine signaling. Melatonin has also been extracted from the seeds and leaves of a number of plants and its concentration in some of this material is several orders of magnitude higher than its night-time plasma value in humans. Melatonin participates in diverse physiological functions. In addition to its timekeeping functions, melatonin is an effective antioxidant which scavenges free radicals and up-regulates several antioxidant enzymes. It also has a strong antiapoptotic signaling function, an effect which it exerts even during ischemia. Melatonin's cytoprotective properties have practical implications in the treatment of neurodegenerative diseases. Melatonin also has immune-enhancing and oncostatic properties. Its 'chronobiotic' properties have been shown to have value in treating various circadian rhythm sleep disorders, such as jet lag or shift-work sleep disorder. Melatonin acting as an 'internal sleep facilitator' promotes sleep, and melatonin's sleep-facilitating properties have been found to be useful for treating insomnia symptoms in elderly and depressive patients. A recently introduced melatonin analog, agomelatine, is also efficient for the treatment of major depressive disorder and bipolar affective disorder. Melatonin's role as a 'photoperiodic molecule' in seasonal reproduction has been established in photoperiodic species, although its regulatory influence in humans remains under investigation. Taken together, this evidence implicates melatonin in a broad range of effects with a significant regulatory influence over many of the body's physiological functions.
Physiological functioning of the ear and masking

NASA Technical Reports Server (NTRS)

1984-01-01

The physiological functions of the ear and the role masking plays in speech communication are examined. Topics under investigation include sound analysis of the ear, the aural reflex, and various types of noise masking.
Water transport and functional dynamics of aquaporins in osmoregulatory organs of fishes.

PubMed

Madsen, Steffen S; Engelund, Morten B; Cutler, Christopher P

2015-08-01

Aquaporins play distinct roles for water transport in fishes as they do in mammals-both at the cellular, organ, and organismal levels. However, with over 32,000 known species of fishes inhabiting almost every aquatic environment, from tidal pools, small mountain streams, to the oceans and extreme salty desert lakes, the challenge to obtain consensus as well as specific knowledge about aquaporin physiology in these vertebrate clades is overwhelming. Because the integumental surfaces of these animals are in intimate contact with the surrounding milieu, passive water loss and uptake represent two of the major osmoregulatory challenges that need compensation. However, neither obligatory nor regulatory water transport nor their mechanisms have been elucidated to the same degree as, for example, ion transport in fishes. Currently fewer than 60 papers address fish aquaporins. Most of these papers identify "what is present" and describe tissue expression patterns in various teleosts. The agnathans, chondrichthyans, and functionality of fish aquaporins generally have received little attention. This review emphasizes the functional physiology of aquaporins in fishes, focusing on transepithelial water transport in osmoregulatory organs in euryhaline species - primarily teleosts, but covering other taxonomic groups as well. Most current knowledge comes from teleosts, and there is a strong need for related information on older fish clades. Our survey aims to stimulate new, original research in this area and to bring together new collaborations across disciplines. © 2015 Marine Biological Laboratory.
Estrogen biology: new insights into GPER function and clinical opportunities.

PubMed

Prossnitz, Eric R; Barton, Matthias

2014-05-25

Estrogens play an important role in the regulation of normal physiology, aging and many disease states. Although the nuclear estrogen receptors have classically been described to function as ligand-activated transcription factors mediating genomic effects in hormonally regulated tissues, more recent studies reveal that estrogens also mediate rapid signaling events traditionally associated with G protein-coupled receptors. The G protein-coupled estrogen receptor GPER (formerly GPR30) has now become recognized as a major mediator of estrogen's rapid cellular effects throughout the body. With the discovery of selective synthetic ligands for GPER, both agonists and antagonists, as well as the use of GPER knockout mice, significant advances have been made in our understanding of GPER function at the cellular, tissue and organismal levels. In many instances, the protective/beneficial effects of estrogen are mimicked by selective GPER agonism and are absent or reduced in GPER knockout mice, suggesting an essential or at least parallel role for GPER in the actions of estrogen. In this review, we will discuss recent advances and our current understanding of the role of GPER and the activity of clinically used drugs, such as SERMs and SERDs, in physiology and disease. We will also highlight novel opportunities for clinical development towards GPER-targeted therapeutics, for molecular imaging, as well as for theranostic approaches and personalized medicine. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Effect of gamma irradiation on hyaluronic acid and dipalmitoylphosphatidylcholine (DPPC) interaction

NASA Astrophysics Data System (ADS)

Ahmad, Ainee Fatimah; Mohd, Hur Munawar Kabir; bin Ayob, Muhammad Taqiyuddin Mawardi; Rosli, Nur Ratasha Alia Md; Mohamed, Faizal; Radiman, Shahidan; Rahman, Irman Abdul

2014-09-01

DPPC lipids are the major component constituting the biological membrane, and their importances in various physiological functions are well documented. Hyaluronic acid (HA) in the synovial joint fluid functions as a lubricant, shock absorber and a nutrient carrier. Gamma irradiation has also been found to be effective in depolymerizing and cleaving molecular chains related to free radicals, thus extends with changes in chemical composition as well as its physiological functions. This research are conducted to investigate the hyaluronic acid (HA) and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) interaction in form of vesicles and its effect to gamma radiation. The size of DPPC vesicles formed via gentle hydration method is between 100 to 200 nm in diameter. HA (0.1, 0.5 and 1.0 mg/ml) was added into the vesicles and characterized by using TEM to determine vesicle size distributions, fusion and rupture of DPPC structure. The results demonstrated that the size of the vesicles approximately between 200 to 300 nm which caused by vesicles fusion with HA and formed even larger vesicles. After being irradiated by 0 to 200 Gy, the size of vesicles decreased as HA was degraded. To elucidate the mechanism of these effects, FTIR spectra were carried out and have shown that at absorption bands at 1700-1750 cm-1 due to formation of carboxylic acid and leads to alteration of HA structure.
Physiological aspects of human milk lipids.

PubMed

Koletzko, B; Rodriguez-Palmero, M; Demmelmair, H; Fidler, N; Jensen, R; Sauerwald, T

2001-11-01

Human milk from healthy and well-nourished mothers is the preferred form of feeding for all healthy newborn infants. The nutrient supply with human milk supports normal growth and development of the infant. Here the general characteristics of human milk lipids and recent knowledge on lactational physiology, composition and functional aspects of human milk lipids are discussed. Lipids in human milk represent the main source of energy for the breastfed baby and supply essential nutrients such as fat-soluble vitamins and polyunsaturated fatty acids (PUFA). The essential fatty acids linoleic and alpha-linolenic acids (LA and ALA) are precursors of long-chain polyunsaturated fatty acids (LC-PUFA), including arachidonic (20:4n-6) and docosahexaenoic (22:6n-3) acids (AA and DHA). LC-PUFA serve as indispensable structural components of cellular membranes and are deposited to a considerable extent in the growing brain and the retina during perinatal development. The supply of preformed LC-PUFA with human milk lipids has been related to functional outcomes of the recipient infants such as visual acuity and development of cognitive functions during the first year of life. Recent stable isotope studies indicate that the major portion of milk PUFA is not derived directly from the maternal diet, but stems from endogenous body stores. Thus, not only the woman's current but also her long-term dietary intake is of marked relevance for milk fat composition.
White matter abnormalities of microstructure and physiological noise in schizophrenia.

PubMed

Cheng, Hu; Newman, Sharlene D; Kent, Jerillyn S; Bolbecker, Amanda; Klaunig, Mallory J; O'Donnell, Brian F; Puce, Aina; Hetrick, William P

2015-12-01

White matter abnormalities in schizophrenia have been revealed by many imaging techniques and analysis methods. One of the findings by diffusion tensor imaging is a decrease in fractional anisotropy (FA), which is an indicator of white matter integrity. On the other hand, elevation of metabolic rate in white matter was observed from positron emission tomography (PET) studies. In this report, we aim to compare the two structural and functional effects on the same subjects. Our comparison is based on the hypothesis that signal fluctuation in white matter is associated with white matter functional activity. We examined the variance of the signal in resting state fMRI and found significant differences between individuals with schizophrenia and non-psychiatric controls specifically in white matter tissue. Controls showed higher temporal signal-to-noise ratios clustered in regions including temporal, frontal, and parietal lobes, cerebellum, corpus callosum, superior longitudinal fasciculus, and other major white matter tracts. These regions with higher temporal signal-to-noise ratio agree well with those showing higher metabolic activity reported by studies using PET. The results suggest that individuals with schizophrenia tend to have higher functional activity in white matter in certain brain regions relative to healthy controls. Despite some overlaps, the distinct regions for physiological noise are different from those for FA derived from diffusion tensor imaging, and therefore provide a unique angle to explore potential mechanisms to white matter abnormality.
Identification and Characterization of Cell Wall Proteins of a Toxic Dinoflagellate Alexandrium catenella Using 2-D DIGE and MALDI TOF-TOF Mass Spectrometry

PubMed Central

Wang, Da-Zhi; Dong, Hong-Po; Li, Cheng; Xie, Zhang-Xian; Lin, Lin; Hong, Hua-Sheng

2011-01-01

The cell wall is an important subcellular component of dinoflagellate cells with regard to various aspects of cell surface-associated ecophysiology, but the full range of cell wall proteins (CWPs) and their functions remain to be elucidated. This study identified and characterized CWPs of a toxic dinoflagellate, Alexandrium catenella, using a combination of 2D fluorescence difference gel electrophoresis (DIGE) and MALDI TOF-TOF mass spectrometry approaches. Using sequential extraction and temperature shock methods, sequentially extracted CWPs and protoplast proteins, respectively, were separated from A. catenella. From the comparison between sequentially extracted CWPs labeled with Cy3 and protoplast proteins labeled with Cy5, 120 CWPs were confidently identified in the 2D DIGE gel. These proteins gave positive identification of protein orthologues in the protein database using de novo sequence analysis and homology-based search. The majority of the prominent CWPs identified were hypothetical or putative proteins with unknown function or no annotation, while cell wall modification enzymes, cell wall structural proteins, transporter/binding proteins, and signaling and defense proteins were tentatively identified in agreement with the expected role of the extracellular matrix in cell physiology. This work represents the first attempt to investigate dinoflagellate CWPs and provides a potential tool for future comprehensive characterization of dinoflagellate CWPs and elucidation of their physiological functions. PMID:21904561
Role of TRP channels in the cardiovascular system.

PubMed

Yue, Zhichao; Xie, Jia; Yu, Albert S; Stock, Jonathan; Du, Jianyang; Yue, Lixia

2015-02-01

The transient receptor potential (TRP) superfamily consists of a large number of nonselective cation channels with variable degree of Ca(2+)-permeability. The 28 mammalian TRP channel proteins can be grouped into six subfamilies: canonical, vanilloid, melastatin, ankyrin, polycystic, and mucolipin TRPs. The majority of these TRP channels are expressed in different cell types including both excitable and nonexcitable cells of the cardiovascular system. Unlike voltage-gated ion channels, TRP channels do not have a typical voltage sensor, but instead can sense a variety of other stimuli including pressure, shear stress, mechanical stretch, oxidative stress, lipid environment alterations, hypertrophic signals, and inflammation products. By integrating multiple stimuli and transducing their activity to downstream cellular signal pathways via Ca(2+) entry and/or membrane depolarization, TRP channels play an essential role in regulating fundamental cell functions such as contraction, relaxation, proliferation, differentiation, and cell death. With the use of targeted deletion and transgenic mouse models, recent studies have revealed that TRP channels are involved in numerous cellular functions and play an important role in the pathophysiology of many diseases in the cardiovascular system. Moreover, several TRP channels are involved in inherited diseases of the cardiovascular system. This review presents an overview of current knowledge concerning the physiological functions of TRP channels in the cardiovascular system and their contributions to cardiovascular diseases. Ultimately, TRP channels may become potential therapeutic targets for cardiovascular diseases. Copyright © 2015 the American Physiological Society.
Function, therapeutic potential and cell biology of BACE proteases: current status and future prospects.

PubMed

Vassar, Robert; Kuhn, Peer-Hendrik; Haass, Christian; Kennedy, Matthew E; Rajendran, Lawrence; Wong, Philip C; Lichtenthaler, Stefan F

2014-07-01

The β-site APP cleaving enzymes 1 and 2 (BACE1 and BACE2) were initially identified as transmembrane aspartyl proteases cleaving the amyloid precursor protein (APP). BACE1 is a major drug target for Alzheimer's disease because BACE1-mediated cleavage of APP is the first step in the generation of the pathogenic amyloid-β peptides. BACE1, which is highly expressed in the nervous system, is also required for myelination by cleaving neuregulin 1. Several recent proteomic and in vivo studies using BACE1- and BACE2-deficient mice demonstrate a much wider range of physiological substrates and functions for both proteases within and outside of the nervous system. For BACE1 this includes axon guidance, neurogenesis, muscle spindle formation, and neuronal network functions, whereas BACE2 was shown to be involved in pigmentation and pancreatic β-cell function. This review highlights the recent progress in understanding cell biology, substrates, and functions of BACE proteases and discusses the therapeutic options and potential mechanism-based liabilities, in particular for BACE inhibitors in Alzheimer's disease. The protease BACE1 is a major drug target in Alzheimer disease. Together with its homolog BACE2, both proteases have an increasing number of functions within and outside of the nervous system. This review highlights recent progress in understanding cell biology, substrates, and functions of BACE proteases and discusses the therapeutic options and potential mechanism-based liabilities, in particular for BACE inhibitors in Alzheimer disease. © 2014 International Society for Neurochemistry.
Transcriptomic response of sea urchin larvae Strongylocentrotus purpuratus to CO2-driven seawater acidification.

PubMed

Todgham, Anne E; Hofmann, Gretchen E

2009-08-01

Ocean acidification from the uptake of anthropogenic CO(2) is expected to have deleterious consequences for many calcifying marine animals. Forecasting the vulnerability of these marine organisms to climate change is linked to an understanding of whether species possess the physiological capacity to compensate for the potentially adverse effects of ocean acidification. We carried out a microarray-based transcriptomic analysis of the physiological response of larvae of a calcifying marine invertebrate, the purple sea urchin, Strongylocentrotus purpuratus, to CO(2)-driven seawater acidification. In lab-based cultures, larvae were raised under conditions approximating current ocean pH conditions (pH 8.01) and at projected, more acidic pH conditions (pH 7.96 and 7.88) in seawater aerated with CO(2) gas. Targeting expression of approximately 1000 genes involved in several biological processes, this study captured changes in gene expression patterns that characterize the transcriptomic response to CO(2)-driven seawater acidification of developing sea urchin larvae. In response to both elevated CO(2) scenarios, larvae underwent broad scale decreases in gene expression in four major cellular processes: biomineralization, cellular stress response, metabolism and apoptosis. This study underscores that physiological processes beyond calcification are impacted greatly, suggesting that overall physiological capacity and not just a singular focus on biomineralization processes is essential for forecasting the impact of future CO(2) conditions on marine organisms. Conducted on targeted and vulnerable species, genomics-based studies, such as the one highlighted here, have the potential to identify potential ;weak links' in physiological function that may ultimately determine an organism's capacity to tolerate future ocean conditions.
Reproductive investment is connected to innate immunity in a long-lived animal.

PubMed

Neggazi, Sara A; Noreikiene, Kristina; Öst, Markus; Jaatinen, Kim

2016-10-01

Life-history theory predicts that organisms optimize their resource allocation strategy to maximize lifetime reproductive success. Individuals can flexibly reallocate resources depending on their life-history stage, and environmental and physiological factors, which lead to variable life-history strategies even within species. Physiological trade-offs between immunity and reproduction are particularly relevant for long-lived species that need to balance current reproduction against future survival and reproduction, but their underlying mechanisms are poorly understood. A major unresolved issue is whether the first-line innate immune function is suppressed by reproductive investment. In this paper, we tested if reproductive investment is associated with the suppression of innate immunity, and how this potential trade-off is resolved depending on physiological state and residual reproductive value. We used long-lived capital-breeding female eiders (Somateria mollissima) as a model. We showed that the innate immune response, measured by plasma bacteria-killing capacity (BKC), was negatively associated with increasing reproductive investment, i.e., with increasing clutch size and advancing incubation stage. Females in a better physiological state, as indexed by low heterophil-to-lymphocyte (H/L) ratios, showed higher BKC during early incubation, but this capacity decreased as incubation progressed, whereas females in poorer state showed low BKC capacity throughout incubation. Although plasma BKC generally declined with increasing H/L ratios, this decrease was most pronounced in young females. Our results demonstrate that reproductive investment can suppress constitutive first-line immune defence in a long-lived bird, but the degree of immunosuppression depends on physiological state and age.
Religious versus Conventional Psychotherapy for Major Depression in Patients with Chronic Medical Illness: Rationale, Methods, and Preliminary Results

PubMed Central

Koenig, Harold G.

2012-01-01

This paper (1) reviews the physical and religious barriers to CBT that disabled medically ill-depressed patients face, (2) discusses research on the relationship between religion and depression-induced physiological changes, (3) describes an ongoing randomized clinical trial of religious versus secular CBT in chronically ill patients with mild-to-moderate major depression designed to (a) overcome physical and religious barriers to CBT and (b) compare the efficacy of religious versus secular CBT in relieving depression and improving immune and endocrine functions, and (4) presents preliminary results that illustrate the technical difficulties that have been encountered in implementing this trial. CBT is being delivered remotely via instant messaging, telephone, or Skype, and Christian, Jewish, Muslim, Buddhist, and Hindu versions of religious CBT are being developed. The preliminary results described here are particular to the technologies employed in this study and are not results from the CBT clinical trial whose findings will be published in the future after the study ends and data are analyzed. The ultimate goal is to determine if a psychotherapy delivered remotely that integrates patients' religious resources improves depression more quickly than a therapy that ignores them, and whether religious CBT is more effective than conventional CBT in reversing depression-induced physiological changes. PMID:22778932

A Neurologist's Guide to TNF Biology and to the Principles behind the Therapeutic Removal of Excess TNF in Disease.

PubMed

Clark, Ian A; Vissel, Bryce

2015-01-01

Tumor necrosis factor (TNF) is an ancient and widespread cytokine required in small amounts for much physiological function. Higher concentrations are central to innate immunity, but if unchecked this cytokine orchestrates much chronic and acute disease, both infectious and noninfectious. While being a major proinflammatory cytokine, it also controls homeostasis and plasticity in physiological circumstances. For the last decade or so these principles have been shown to apply to the central nervous system as well as the rest of the body. Nevertheless, whereas this approach has been a major success in treating noncerebral disease, its investigation and potential widespread adoption in chronic neurological conditions has inexplicably stalled since the first open trial almost a decade ago. While neuroscience is closely involved with this approach, clinical neurology appears to be reticent in engaging with what it offers patients. Unfortunately, the basic biology of TNF and its relevance to disease is largely outside the traditions of neurology. The purpose of this review is to facilitate lowering communication barriers between the traditional anatomically based medical specialties through recognition of shared disease mechanisms and thus advance the prospects of a large group of patients with neurodegenerative conditions for whom at present little can be done.
Stress physiology as a predictor of survival in Galapagos marine iguanas

PubMed Central

Romero, L. Michael; Wikelski, Martin

2010-01-01

Although glucocorticoid hormones are considered important physiological regulators for surviving adverse environmental stimuli (stressors), evidence for such a role is sparse and usually extrapolated from glucocorticoid effects under laboratory, short-term and/or non-emergency conditions. Galápagos marine iguanas (Amblyrhynchus cristatus) provide an excellent model for determining the ultimate function of a glucocorticoid response because susceptibility to starvation induced by El Niño conditions is essentially their only major natural stressor. In a prospective study, we captured 98 adult male marine iguanas and assessed four major components of their glucocorticoid response: baseline corticosterone titres; corticosterone responses to acute stressors (capture and handling); the maximal capacity to secrete corticosterone (via adrenocorticotropin injection); and the ability to terminate corticosterone responses (negative feedback). Several months after collecting initial measurements, weak El Niño conditions affected the Galápagos and 23 iguanas died. The dead iguanas were typified by a reduced efficacy of negative feedback (i.e. poorer post-stress suppression of corticosterone release) compared with surviving iguanas. We found no prior differences between dead and alive iguanas in baseline corticosterone concentrations, responses to acute stressors, nor in capacity to respond. These data suggest that a greater ability to terminate a stress response conferred a survival advantage during starvation. PMID:20504812
Coral Carbonic Anhydrases: Regulation by Ocean Acidification.

PubMed

Zoccola, Didier; Innocenti, Alessio; Bertucci, Anthony; Tambutté, Eric; Supuran, Claudiu T; Tambutté, Sylvie

2016-06-03

Global change is a major threat to the oceans, as it implies temperature increase and acidification. Ocean acidification (OA) involving decreasing pH and changes in seawater carbonate chemistry challenges the capacity of corals to form their skeletons. Despite the large number of studies that have investigated how rates of calcification respond to ocean acidification scenarios, comparatively few studies tackle how ocean acidification impacts the physiological mechanisms that drive calcification itself. The aim of our paper was to determine how the carbonic anhydrases, which play a major role in calcification, are potentially regulated by ocean acidification. For this we measured the effect of pH on enzyme activity of two carbonic anhydrase isoforms that have been previously characterized in the scleractinian coral Stylophora pistillata. In addition we looked at gene expression of these enzymes in vivo. For both isoforms, our results show (1) a change in gene expression under OA (2) an effect of OA and temperature on carbonic anhydrase activity. We suggest that temperature increase could counterbalance the effect of OA on enzyme activity. Finally we point out that caution must, thus, be taken when interpreting transcriptomic data on carbonic anhydrases in ocean acidification and temperature stress experiments, as the effect of these stressors on the physiological function of CA will depend both on gene expression and enzyme activity.
Mild chronic obstructive pulmonary disease: why spirometry is not sufficient!

PubMed

Elbehairy, Amany F; Parraga, Grace; Webb, Katherine A; Neder, J Alberto; O'Donnell, Denis E

2017-07-01

Chronic obstructive pulmonary disease (COPD) - an inflammatory disease of the airways, alveoli and lung microvasculature - is a leading cause of death worldwide. Smokers with milder airway obstruction constitute the majority of patients with this disease. Many studies have shown increased morbidity, activity-related dyspnea, exercise intolerance and mortality in such patients, compared with age-matched healthy populations. Clinical evaluation of symptomatic smokers with ostensibly mild airway obstruction poses a challenge in clinical practice as spirometry can obscure extensive heterogeneous pathophysiological impairment. Areas covered: A detailed review of the evidence for complex biological, physiological and radiological abnormalities in smokers who barely fit arbitrary spirometric criteria for COPD diagnosis. A brief discussion of the debate about current diagnostic spirometric criteria for COPD that can lead to diagnostic confusion and, in-some-instances, to inappropriate management. Finally, we provide a review of the clinical implications of these structural and functional abnormalities and try to build a solid rationale for earlier detection and effective, timely management. Expert commentary: The prevalence of mild COPD among smokers is high, yet under-diagnosis remains a major problem and there is lack of evidence-based management recommendations for this sub-population. Further tests beyond spirometry are useful in uncovering patho-physiological derangements that are clinically relevant.
Laboratory evolution of the migratory polymorphism in the sand cricket: combining physiology with quantitative genetics.

PubMed

Roff, Derek A; Fairbairn, Daphne J

2007-01-01

Predicting evolutionary change is the central goal of evolutionary biology because it is the primary means by which we can test evolutionary hypotheses. In this article, we analyze the pattern of evolutionary change in a laboratory population of the wing-dimorphic sand cricket Gryllus firmus resulting from relaxation of selection favoring the migratory (long-winged) morph. Based on a well-characterized trade-off between fecundity and flight capability, we predict that evolution in the laboratory environment should result in a reduction in the proportion of long-winged morphs. We also predict increased fecundity and reduced functionality and weight of the major flight muscles in long-winged females but little change in short-winged (flightless) females. Based on quantitative genetic theory, we predict that the regression equation describing the trade-off between ovary weight and weight of the major flight muscles will show a change in its intercept but not in its slope. Comparisons across generations verify all of these predictions. Further, using values of genetic parameters estimated from previous studies, we show that a quantitative genetic simulation model can account for not only the qualitative changes but also the evolutionary trajectory. These results demonstrate the power of combining quantitative genetic and physiological approaches for understanding the evolution of complex traits.
Anatomy and Physiology. Module Set II: Major Body Systems. Teacher Edition [and] Student Edition. Surgical Technology.

ERIC Educational Resources Information Center

Hilley, Robert

This document, which is the second part of a two-part set of modules on anatomy and physiology for future surgical technicians, contains the teacher and student editions of an introduction to anatomy and physiology that consists of modules on the following body systems: integumentary system; skeletal system; muscular system; nervous system;…
Exercise Physiology: A Brief History and Recommendations Regarding Content Requirements for the Kinesiology Major

ERIC Educational Resources Information Center

Ivy, John L.

2007-01-01

The knowledge base that defines exercise physiology is central to the discipline of kinesiology. By the late 19th century, interest in physical training, physical education, and sports began to emerge in the United States. By the beginning of the 20th century, exercise physiology was being included in college physical education degree programs,…
Physiological and psychosocial factors that predict HIV-related fatigue.

PubMed

Barroso, Julie; Hammill, Bradley G; Leserman, Jane; Salahuddin, Naima; Harmon, James L; Pence, Brian Wells

2010-12-01

Fatigue is one of the most common and debilitating symptoms experienced by HIV-infected people. We report the results of our longitudinal analysis of physiological and psychosocial factors that were thought to predict changes in HIV-related fatigue in 128 participants over a 1-year period, in an effort to sort out the complex interplay among a comprehensive set of physiological and psychosocial variables. Physiological measures included hepatic function (aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transpeptidase, alkaline phosphatase, total bilirubin, hepatitis C status), thyroid function (thyroid stimulating hormone, thyroxine), HIV viral load, immunologic function (CD4, CD8, CD4/CD8 ratio, CD16, CD8CD38), gonadal function (testosterone, dehydroepiandrosterone), hematologic function (hemoglobin, hematocrit, serum erythropoietin), and cellular injury (lactic acid). Psychosocial measures included childhood and adult trauma, anxiety, depression, social support, stressful life events, and post-traumatic stress disorder (PTSD). Unemployment, not being on antiretroviral therapy, having fewer years since HIV diagnosis, more childhood trauma, more stressful life events, less social support, and more psychological distress (e.g., PTSD, anxiety and depression) put HIV-infected persons at risk for greater fatigue intensity and fatigue-related impairment in functioning during 1-year follow-up. Physiological variables did not predict greater fatigue. Stressful life events had both direct and indirect effects on fatigue.
Physiological and Psychosocial Factors that Predict HIV-Related Fatigue

PubMed Central

Hammill, Bradley G.; Leserman, Jane; Salahuddin, Naima; Harmon, James L.; Pence, Brian Wells

2010-01-01

Fatigue is one of the most common and debilitating symptoms experienced by HIV-infected people. We report the results of our longitudinal analysis of physiological and psychosocial factors that were thought to predict changes in HIV-related fatigue in 128 participants over a 1-year period, in an effort to sort out the complex interplay among a comprehensive set of physiological and psychosocial variables. Physiological measures included hepatic function (aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transpeptidase, alkaline phosphatase, total bilirubin, hepatitis C status), thyroid function (thyroid stimulating hormone, thyroxine), HIV viral load, immunologic function (CD4, CD8, CD4/CD8 ratio, CD16, CD8CD38), gonadal function (testosterone, dehydroepiandrosterone), hematologic function (hemoglobin, hematocrit, serum erythropoietin), and cellular injury (lactic acid). Psychosocial measures included childhood and adult trauma, anxiety, depression, social support, stressful life events, and post-traumatic stress disorder (PTSD). Unemployment, not being on antiretroviral therapy, having fewer years since HIV diagnosis, more childhood trauma, more stressful life events, less social support, and more psychological distress (e.g., PTSD, anxiety and depression) put HIV-infected persons at risk for greater fatigue intensity and fatigue-related impairment in functioning during 1-year follow-up. Physiological variables did not predict greater fatigue. Stressful life events had both direct and indirect effects on fatigue. PMID:20352317
Allocation, stress tolerance and carbon transport in plants: how does phloem physiology affect plant ecology?

PubMed

Savage, Jessica A; Clearwater, Michael J; Haines, Dustin F; Klein, Tamir; Mencuccini, Maurizio; Sevanto, Sanna; Turgeon, Robert; Zhang, Cankui

2016-04-01

Despite the crucial role of carbon transport in whole plant physiology and its impact on plant-environment interactions and ecosystem function, relatively little research has tried to examine how phloem physiology impacts plant ecology. In this review, we highlight several areas of active research where inquiry into phloem physiology has increased our understanding of whole plant function and ecological processes. We consider how xylem-phloem interactions impact plant drought tolerance and reproduction, how phloem transport influences carbon allocation in trees and carbon cycling in ecosystems and how phloem function mediates plant relations with insects, pests, microbes and symbiotes. We argue that in spite of challenges that exist in studying phloem physiology, it is critical that we consider the role of this dynamic vascular system when examining the relationship between plants and their biotic and abiotic environment. © 2015 John Wiley & Sons Ltd.
Molecular bases of circadian rhythmicity in renal physiology and pathology

PubMed Central

Bonny, Olivier; Vinciguerra, Manlio; Gumz, Michelle L.; Mazzoccoli, Gianluigi

2013-01-01

The physiological processes that maintain body homeostasis oscillate during the day. Diurnal changes characterize kidney functions, comprising regulation of hydro-electrolytic and acid-base balance, reabsorption of small solutes and hormone production. Renal physiology is characterized by 24-h periodicity and contributes to circadian variability of blood pressure levels, related as well to nychthemeral changes of sodium sensitivity, physical activity, vascular tone, autonomic function and neurotransmitter release from sympathetic innervations. The circadian rhythmicity of body physiology is driven by central and peripheral biological clockworks and entrained by the geophysical light/dark cycle. Chronodisruption, defined as the mismatch between environmental–social cues and physiological–behavioral patterns, causes internal desynchronization of periodic functions, leading to pathophysiological mechanisms underlying degenerative, immune related, metabolic and neoplastic diseases. In this review we will address the genetic, molecular and anatomical elements that hardwire circadian rhythmicity in renal physiology and subtend disarray of time–dependent changes in renal pathology. PMID:23901050
Physiology of man and animals in the Tenth Five-Year Plan: Proceedings of the Thirteenth Congress of the I. P. Pavlov All-Union Physiological Society

NASA Technical Reports Server (NTRS)

Lange, K. A.

1980-01-01

Research in the field of animal and human physiology is reviewed. The following topics on problems of physiological science and related fields of knowledge are discussed: neurophysiology and higher nervous activity, physiology of sensory systems, physiology of visceral systems, evolutionary and ecological physiology, physiological cybernetics, computer application in physiology, information support of physiological research, history and theory of development of physiology. Also discussed were: artificial intelligence, physiological problems of reflex therapy, correlation of structure and function of the brain, adaptation and activity, microcirculation, and physiological studies in nerve and mental diseases.
Physiological functions of MTA family of proteins.

PubMed

Sen, Nirmalya; Gui, Bin; Kumar, Rakesh

2014-12-01

Although the functional significance of the metastasic tumor antigen (MTA) family of chromatin remodeling proteins in the pathobiology of cancer is fairly well recognized, the physiological role of MTA proteins continues to be an understudied research area and is just beginning to be recognized. Similar to cancer cells, MTA1 also modulates the expression of target genes in normal cells either by acting as a corepressor or coactivator. In addition, physiological functions of MTA proteins are likely to be influenced by its differential expression, subcellular localization, and regulation by upstream modulators and extracellular signals. This review summarizes our current understanding of the physiological functions of the MTA proteins in model systems. In particular, we highlight recent advances of the role MTA proteins play in the brain, eye, circadian rhythm, mammary gland biology, spermatogenesis, liver, immunomodulation and inflammation, cellular radio-sensitivity, and hematopoiesis and differentiation. Based on the growth of knowledge regarding the exciting new facets of the MTA family of proteins in biology and medicine, we speculate that the next burst of findings in this field may reveal further molecular regulatory insights of non-redundant functions of MTA coregulators in the normal physiology as well as in pathological conditions outside cancer.
Biological properties of extracellular vesicles and their physiological functions

PubMed Central

Yáñez-Mó, María; Siljander, Pia R.-M.; Andreu, Zoraida; Zavec, Apolonija Bedina; Borràs, Francesc E.; Buzas, Edit I.; Buzas, Krisztina; Casal, Enriqueta; Cappello, Francesco; Carvalho, Joana; Colás, Eva; Silva, Anabela Cordeiro-da; Fais, Stefano; Falcon-Perez, Juan M.; Ghobrial, Irene M.; Giebel, Bernd; Gimona, Mario; Graner, Michael; Gursel, Ihsan; Gursel, Mayda; Heegaard, Niels H. H.; Hendrix, An; Kierulf, Peter; Kokubun, Katsutoshi; Kosanovic, Maja; Kralj-Iglic, Veronika; Krämer-Albers, Eva-Maria; Laitinen, Saara; Lässer, Cecilia; Lener, Thomas; Ligeti, Erzsébet; Linē, Aija; Lipps, Georg; Llorente, Alicia; Lötvall, Jan; Manček-Keber, Mateja; Marcilla, Antonio; Mittelbrunn, Maria; Nazarenko, Irina; Hoen, Esther N.M. Nolte-‘t; Nyman, Tuula A.; O'Driscoll, Lorraine; Olivan, Mireia; Oliveira, Carla; Pállinger, Éva; del Portillo, Hernando A.; Reventós, Jaume; Rigau, Marina; Rohde, Eva; Sammar, Marei; Sánchez-Madrid, Francisco; Santarém, N.; Schallmoser, Katharina; Ostenfeld, Marie Stampe; Stoorvogel, Willem; Stukelj, Roman; Van der Grein, Susanne G.; Vasconcelos, M. Helena; Wauben, Marca H. M.; De Wever, Olivier

2015-01-01

In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system. PMID:25979354
Biological properties of extracellular vesicles and their physiological functions.

PubMed

Yáñez-Mó, María; Siljander, Pia R-M; Andreu, Zoraida; Zavec, Apolonija Bedina; Borràs, Francesc E; Buzas, Edit I; Buzas, Krisztina; Casal, Enriqueta; Cappello, Francesco; Carvalho, Joana; Colás, Eva; Cordeiro-da Silva, Anabela; Fais, Stefano; Falcon-Perez, Juan M; Ghobrial, Irene M; Giebel, Bernd; Gimona, Mario; Graner, Michael; Gursel, Ihsan; Gursel, Mayda; Heegaard, Niels H H; Hendrix, An; Kierulf, Peter; Kokubun, Katsutoshi; Kosanovic, Maja; Kralj-Iglic, Veronika; Krämer-Albers, Eva-Maria; Laitinen, Saara; Lässer, Cecilia; Lener, Thomas; Ligeti, Erzsébet; Linē, Aija; Lipps, Georg; Llorente, Alicia; Lötvall, Jan; Manček-Keber, Mateja; Marcilla, Antonio; Mittelbrunn, Maria; Nazarenko, Irina; Nolte-'t Hoen, Esther N M; Nyman, Tuula A; O'Driscoll, Lorraine; Olivan, Mireia; Oliveira, Carla; Pállinger, Éva; Del Portillo, Hernando A; Reventós, Jaume; Rigau, Marina; Rohde, Eva; Sammar, Marei; Sánchez-Madrid, Francisco; Santarém, N; Schallmoser, Katharina; Ostenfeld, Marie Stampe; Stoorvogel, Willem; Stukelj, Roman; Van der Grein, Susanne G; Vasconcelos, M Helena; Wauben, Marca H M; De Wever, Olivier

2015-01-01

In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system.
Short communication: Characteristics of student success in an undergraduate physiology and anatomy course.

PubMed

Gwazdauskas, F C; McGilliard, M L; Corl, B A

2014-10-01

Several factors affect the success of students in college classes. The objective of this research was to determine what factors affect success of undergraduate students in an anatomy and physiology class. Data were collected from 602 students enrolled in the Agriculture and Life Sciences (ALS) 2304 Animal Physiology and Anatomy course from 2005 through 2012. The data set included 476 females (79.1%) and 126 males (20.9%). Time to complete exams was recorded for each student. For statistical analyses, students' majors were animal and poultry sciences (APSC), agricultural sciences, biochemistry, biological sciences, dairy science, and "other," which combined all other majors. All analyses were completed using the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC). Gender, major, matriculation year, major by year interaction, gender by year interaction, and time to complete the exam affected final course grade. The significant gender effect was manifested in the final grade percentage of 75.9 ± 0.4 for female students compared with 72.3 ± 0.6 for male students. Junior males had final course grades comparable with those of females, but sophomore and senior males had lower final course grades than other combinations. Biology majors had a final grade of 82.4 ± 0.6 and this grade was greater than all other majors. Students classified as "other" had a final score of 74.4 ± 0.8, which was greater than agricultural science majors (69.5 ± 0.9). The APSC grade (72.6 ± 0.5) was higher than the agricultural science majors. Junior students had significantly greater final grades (76.1 ± 0.5) than sophomores (73.3 ± 0.6) and seniors (72.9 ± 0.9). All biology students had greater final grades than all other majors, but biochemistry juniors had greater final course grades than APSC, agricultural science, and dairy science juniors. "Other" seniors had greater final course grades than agricultural science seniors. The regression for time to complete the exam was curvilinear and suggests that highest exam scores were at about 90-min completion time. It may be that some male students need better preparation for anatomy and physiology and their educational preparation should mimic that of female students more in terms of advance-placement biology in high school. These results suggest that biology majors might be better prepared for animal anatomy and physiology than other students. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Assessment of adnexal masses using ultrasound: a practical review

PubMed Central

Smorgick, Noam; Maymon, Ron

2014-01-01

Pelvic ultrasound is commonly used as part of the routine gynecologic exams, resulting in diagnosis of adnexal masses, the majority of which are functional or benign. However, due to the possible complications involving benign adnexal cysts (ie, adnexal torsion, pelvic pain) and the utmost importance of early diagnosis and treatment of ovarian cancer, the correct ultrasound diagnosis of adnexal masses is essential in clinical practice. This review will describe the typical ultrasound appearance of the common physiologic, benign, and malignant adnexal masses with the aim of aiding the clinician to reach the correct diagnosis. PMID:25285023
Research on habituation to novel visual-vestibular environments with particular reference to space flight

NASA Technical Reports Server (NTRS)

Young, L. R.

1976-01-01

Progress in the development of a cohesive theory of the underlying physiological mechanisms associated with spatial orientation in unusual environments is described. Results can be applied to providing means of preventing and/or minimizing the space motion sickness which has been observed during prolonged space missions. Three major areas were investigated: (1) the interaction of visual and vestibular cues in conflict in the human, (2) the plasticity of the vestibulo-ocular reflex in monkeys, and (3) end organ function in the ray with particular emphasis on the effect of ionic concentration.
Physiology in perspective: The Wisdom of the Body. Neural control of the kidney.

PubMed

DiBona, Gerald F

2005-09-01

Cannon equated the fluid matrix of the body with Bernard's concept of the internal environment and emphasized the importance of "the safe-guarding of an effective fluid matrix." He further emphasized the important role of the autonomic nervous system in the establishment and maintenance of homeostasis in the internal environment. This year's Cannon Lecture discusses the important role of the renal sympathetic nerves to regulate various aspects of overall renal function and to serve as one of the major "self-regulatory agencies which operate to preserve the constancy of the fluid matrix."
Clinical importance of re-interpretation of PET/CT scanning in patients referred to a tertiary care medical centre.

PubMed

Löfgren, Johan; Loft, Annika; Barbosa de Lima, Vinicius Araújo; Østerlind, Kell; von Benzon, Eric; Højgaard, Liselotte

2017-03-01

To evaluate, in a controlled prospective manner with double-blind read, whether there are differences in interpretations of PET/CT scans at our tertiary medical centre, Rigshospitalet, compared to the external hospitals. Ninety consecutive patients referred to our department who had an external F-18-FDG PET/CT scan were included. Only information that had been available at the time of the initial reading at the external hospital was available at re-interpretation. Teams with one radiologist and one nuclear medicine physician working side by side performed the re-interpretation in consensus. Two oncologists subsequently and independently compared the original reports with the re-interpretation reports. In case of 'major discordance', the oncologists assessed the respective reports validities. The interpretations were graded as 'accordant' in 43 patients (48%), 'minor discordance' in 30 patients (33%) and 'major discordance' in 17 patients (19%). In 11 (65%) of the 17 cases graded as 'major discordance', it was possible to determine which report that was most correct. In 9 of these 11 cases (82%), the re-interpretation was most correct; in one case, the original report and in another case, both interpretations were incorrect. Major discordant interpretations were frequent [19% (17 of 90 cases)]. In those cases where follow-up could assess the validity, the re-interpretation at Rigshospitalet was most correct in 9 of 11 cases (82%), indicating that there is a difference in expertise in interpreting PET/CT at a tertiary referral hospital compared to primary local hospitals. © 2015 The Authors. Clinical Physiology and Functional Imaging published by John Wiley & Sons Ltd on behalf of Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Fundamental principles in bacterial physiology—history, recent progress, and the future with focus on cell size control: a review

NASA Astrophysics Data System (ADS)

Jun, Suckjoon; Si, Fangwei; Pugatch, Rami; Scott, Matthew

2018-05-01

Bacterial physiology is a branch of biology that aims to understand overarching principles of cellular reproduction. Many important issues in bacterial physiology are inherently quantitative, and major contributors to the field have often brought together tools and ways of thinking from multiple disciplines. This article presents a comprehensive overview of major ideas and approaches developed since the early 20th century for anyone who is interested in the fundamental problems in bacterial physiology. This article is divided into two parts. In the first part (sections 1–3), we review the first ‘golden era’ of bacterial physiology from the 1940s to early 1970s and provide a complete list of major references from that period. In the second part (sections 4–7), we explain how the pioneering work from the first golden era has influenced various rediscoveries of general quantitative principles and significant further development in modern bacterial physiology. Specifically, section 4 presents the history and current progress of the ‘adder’ principle of cell size homeostasis. Section 5 discusses the implications of coarse-graining the cellular protein composition, and how the coarse-grained proteome ‘sectors’ re-balance under different growth conditions. Section 6 focuses on physiological invariants, and explains how they are the key to understanding the coordination between growth and the cell cycle underlying cell size control in steady-state growth. Section 7 overviews how the temporal organization of all the internal processes enables balanced growth. In the final section 8, we conclude by discussing the remaining challenges for the future in the field.
Looking at physiological anthropology from a historical standpoint.

PubMed

Katsuura, Tetsuo

2005-05-01

As one way of thinking about physiological anthropology, let us survey it from a historical viewpoint. At the beginning of the 19th century, Blumenbach, considered the father of Physical Anthropology, wrote his "Handbook of Comparative Anatomy and Physiology." The subsequent research conducted and papers written by researchers such as Broca and Martin pointed in the direction of physiological anthropology; furthermore, the research carried out by the American researchers Demon and Baker had a physiological anthropology "feel." The courses in Physiological Anthropology taught by Tokizane exerted a major influence on physiological anthropology in Japan. The precursor of the Japan Society of Physiological Anthropology, organized by Sato in 1978, was extremely significant in the effect that it had on the subsequent development of physiological anthropology. The holding of the biennial International Congress of Physiological Anthropology, along with the allocation of the Research sub-field of Physiological Anthropology in the Grant-in-Aid for Scientific Research, would seem to suggest that the field of physiological anthropology is set to increasingly grow and evolve.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, T.; Teo, L.H.; Sin, Y.M.

Glutathione (GSH) is the major non-protein thiol in animals, and involved in a number of important physiological and detoxification processes. It has been suggested that this tripeptide protects thiol groups in proteins from oxidation, functions as an intracellular redox buffer and serves as a reservoir of cysteine. Tissue GSH is also known to be involved in the metabolism and detoxification of endogenous and exogenous substances, including the binding of inorganic mercury ions. Therefore, a change in the amount of GSH in tissues may be considered to reflect the effects of deposited mercury on tissue function. The functions of the tripeptidemore » have been studied less thoroughly in invertebrates than in vertebrates. The purpose of this study was to determine whether there were changes in the amounts of tissue GSH in the green mussel, Perna viridis, at various time intervals after metal exposure. 22 refs., 1 fig., 1 tab.« less
Tracing the evolutionary origins of insect renal function.

PubMed

Halberg, Kenneth A; Terhzaz, Selim; Cabrero, Pablo; Davies, Shireen A; Dow, Julian A T

2015-04-21

Knowledge on neuropeptide receptor systems is integral to understanding animal physiology. Yet, obtaining general insight into neuropeptide signalling in a clade as biodiverse as the insects is problematic. Here we apply fluorescent analogues of three key insect neuropeptides to map renal tissue architecture across systematically chosen representatives of the major insect Orders, to provide an unprecedented overview of insect renal function and control. In endopterygote insects, such as Drosophila, two distinct transporting cell types receive separate neuropeptide signals, whereas in the ancestral exopterygotes, a single, general cell type mediates all signals. Intriguingly, the largest insect Order Coleoptera (beetles) has evolved a unique approach, in which only a small fraction of cells are targets for neuropeptide action. In addition to demonstrating a universal utility of this technology, our results reveal not only a generality of signalling by the evolutionarily ancient neuropeptide families but also a clear functional separation of the types of cells that mediate the signal.
Collagens--structure, function, and biosynthesis.

PubMed

Gelse, K; Pöschl, E; Aigner, T

2003-11-28

The extracellular matrix represents a complex alloy of variable members of diverse protein families defining structural integrity and various physiological functions. The most abundant family is the collagens with more than 20 different collagen types identified so far. Collagens are centrally involved in the formation of fibrillar and microfibrillar networks of the extracellular matrix, basement membranes as well as other structures of the extracellular matrix. This review focuses on the distribution and function of various collagen types in different tissues. It introduces their basic structural subunits and points out major steps in the biosynthesis and supramolecular processing of fibrillar collagens as prototypical members of this protein family. A final outlook indicates the importance of different collagen types not only for the understanding of collagen-related diseases, but also as a basis for the therapeutical use of members of this protein family discussed in other chapters of this issue.
[Physiotherapy for juvenile idiopathic arthritis].

PubMed

Spamer, M; Georgi, M; Häfner, R; Händel, H; König, M; Haas, J-P

2012-07-01

Control of disease activity and recovery of function are major issues in the treatment of children and adolescents suffering from juvenile idiopathic arthritis (JIA). Functional therapies including physiotherapy are important components in the multidisciplinary teamwork and each phase of the disease requires different strategies. While in the active phase of the disease pain alleviation is the main focus, the inactive phase requires strategies for improving motility and function. During remission the aim is to regain general fitness by sports activities. These phase adapted strategies must be individually designed and usually require a combination of different measures including physiotherapy, occupational therapy, massage as well as other physical procedures and sport therapy. There are only few controlled studies investigating the effectiveness of physical therapies in JIA and many strategies are derived from long-standing experience. New results from physiology and sport sciences have contributed to the development in recent years. This report summarizes the basics and main strategies of physical therapy in JIA.
Probiotics and human health: a clinical perspective

PubMed Central

Gill, H; Guarner, F

2004-01-01

There is unequivocal evidence that administration of probiotics could be effective in the treatment of acute infectious diarrhoea in children and the prevention of antibiotic associated diarrhoea and nosocomial/community acquired diarrhoea. Encouraging evidence is also emerging for the effectiveness of probiotics in the prevention and management of pouchitis and paediatric atopic diseases, and the prevention of postoperative infections. There is also strong evidence that certain probiotic strains are able to enhance immune function, especially in subjects with less than adequate immune function such as the elderly. Efficacy of probiotics in the prevention of traveller's diarrhoea, sepsis associated with severe acute pancreatitis, and cancers, the management of ulcerative colitis, and lowering of blood cholesterol remains unproven. In addition to firm evidence of efficacy (for a range of conditions), major gaps exist in our knowledge regarding the mechanisms by which probiotics modulate various physiological functions and the optimum dose, frequency, and duration of treatment for different probiotic strains. PMID:15356352
[GPCRs heterodimerization: a new way towards the discovery of function for the orphan receptors?].

PubMed

Levoye, Angélique; Jockers, Ralf

2007-01-01

G protein-coupled receptors (GPCRs), also called seven transmembrane domain (7TM) proteins, represent the largest family of cell surface receptors. GPCRs control a variety of physiological processes, are involved in multiple diseases and are major drug targets. Despite a vast effort of academic and industrial research, more than one hundred receptors remain orphans. These orphan GPCRs offer a great potential for drug discovery, as almost 60% of currently prescribed drugs target GPCRs. Deorphenization strategies have concentrated mainly on the identification of the natural ligands of these proteins. Recent advances have shown that orphan GPCRs, similar to orphan nuclear receptors, can regulate the function of non-orphan receptors by heterodimerization. These findings not only help to better understand the extraordinary diversity of GPCRs, but also open new perspectives for the identification of the function of these orphan receptors that hold great therapeutic potential.
Mitochondrial Function in Sepsis

PubMed Central

Arulkumaran, Nishkantha; Deutschman, Clifford S.; Pinsky, Michael R.; Zuckerbraun, Brian; Schumacker, Paul T.; Gomez, Hernando; Gomez, Alonso; Murray, Patrick; Kellum, John A.

2015-01-01

Mitochondria are an essential part of the cellular infrastructure, being the primary site for high energy adenosine triphosphate (ATP) production through oxidative phosphorylation. Clearly, in severe systemic inflammatory states, like sepsis, cellular metabolism is usually altered and end organ dysfunction not only common but predictive of long term morbidity and mortality. Clearly, interest is mitochondrial function both as a target for intracellular injury and response to extrinsic stress have been a major focus of basic science and clinical research into the pathophysiology of acute illness. However, mitochondria have multiple metabolic and signaling functions that may be central in both the expression of sepsis and its ultimate outcome. In this review, the authors address five primary questions centered on the role of mitochondria in sepsis. This review should be used as both a summary source in placing mitochondrial physiology within the context of acute illness and as a focal point for addressing new research into diagnostic and treatment opportunities these insights provide. PMID:26871665
MITOCHONDRIAL FUNCTION IN SEPSIS.

PubMed

Arulkumaran, Nishkantha; Deutschman, Clifford S; Pinsky, Michael R; Zuckerbraun, Brian; Schumacker, Paul T; Gomez, Hernando; Gomez, Alonso; Murray, Patrick; Kellum, John A

2016-03-01

Mitochondria are an essential part of the cellular infrastructure, being the primary site for high-energy adenosine triphosphate production through oxidative phosphorylation. Clearly, in severe systemic inflammatory states, like sepsis, cellular metabolism is usually altered, and end organ dysfunction is not only common, but also predictive of long-term morbidity and mortality. Clearly, interest is mitochondrial function both as a target for intracellular injury and response to extrinsic stress have been a major focus of basic science and clinical research into the pathophysiology of acute illness. However, mitochondria have multiple metabolic and signaling functions that may be central in both the expression of sepsis and its ultimate outcome. In this review, the authors address five primary questions centered on the role of mitochondria in sepsis. This review should be used both as a summary source in placing mitochondrial physiology within the context of acute illness and as a focal point for addressing new research into diagnostic and treatment opportunities these insights provide.
Regulation and physiological functions of mammalian phospholipase C.

PubMed

Nakamura, Yoshikazu; Fukami, Kiyoko

2017-04-01

Phospholipase C (PLC) is a key enzyme in phosphoinositide metabolism. PLC hydrolyses phosphatidylinositol 4,5-bis-phosphate to generate two second messengers, inositol 1,4,5-trisphosphate and diacylglycerol, that generate diverse cellular responses. PLC is activated by various signalling molecules, including Ca2+, heterometric G proteins, small G proteins, and receptor/non-receptor tyrosine kinases. In addition to their enzymatic activity, some PLC subtypes also function as a guanine nucleotide exchange factor, GTPase-activating protein, and adaptor protein, independent of their lipase activity. There are 13 PLC isozymes in mammals, and they are categorized into six classes based on structure. Generation and analysis of genetically modified mice has revealed the unexpectedly diverse physiological functions of PLC isozymes. Although all PLC isozymes catalyze the same reaction, each PLC isozyme has unique physiological functions. This review focuses on the regulation and physiological functions of PLCs. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.
Plasticity of brain wave network interactions and evolution across physiologic states

PubMed Central

Liu, Kang K. L.; Bartsch, Ronny P.; Lin, Aijing; Mantegna, Rosario N.; Ivanov, Plamen Ch.

2015-01-01

Neural plasticity transcends a range of spatio-temporal scales and serves as the basis of various brain activities and physiologic functions. At the microscopic level, it enables the emergence of brain waves with complex temporal dynamics. At the macroscopic level, presence and dominance of specific brain waves is associated with important brain functions. The role of neural plasticity at different levels in generating distinct brain rhythms and how brain rhythms communicate with each other across brain areas to generate physiologic states and functions remains not understood. Here we perform an empirical exploration of neural plasticity at the level of brain wave network interactions representing dynamical communications within and between different brain areas in the frequency domain. We introduce the concept of time delay stability (TDS) to quantify coordinated bursts in the activity of brain waves, and we employ a system-wide Network Physiology integrative approach to probe the network of coordinated brain wave activations and its evolution across physiologic states. We find an association between network structure and physiologic states. We uncover a hierarchical reorganization in the brain wave networks in response to changes in physiologic state, indicating new aspects of neural plasticity at the integrated level. Globally, we find that the entire brain network undergoes a pronounced transition from low connectivity in Deep Sleep and REM to high connectivity in Light Sleep and Wake. In contrast, we find that locally, different brain areas exhibit different network dynamics of brain wave interactions to achieve differentiation in function during different sleep stages. Moreover, our analyses indicate that plasticity also emerges in frequency-specific networks, which represent interactions across brain locations mediated through a specific frequency band. Comparing frequency-specific networks within the same physiologic state we find very different degree of network connectivity and link strength, while at the same time each frequency-specific network is characterized by a different signature pattern of sleep-stage stratification, reflecting a remarkable flexibility in response to change in physiologic state. These new aspects of neural plasticity demonstrate that in addition to dominant brain waves, the network of brain wave interactions is a previously unrecognized hallmark of physiologic state and function. PMID:26578891
[PSYCHO PHYSIOLOGICAL MARKERS OF ACCELERATED AGING AMONG THOSE WORKING WITH OCCUPATIONAL HAZARDS].

PubMed

Bashkireva, A S; Kachan, Ye Yu; Kulapina, M E

2015-01-01

We assessed the significance of psycho physiological markers of accelerated aging of the function of attention using comparative analysis of two occupational groups in order to reveal how the working process affects mental work capacity. We revealed peculiarities of systemic structure of functions which determine mental work capacity depending on the age and length of service in lorry drivers. It was proved that decrease in the mnestic functions of lorry-drivers takes place 10-15 years earlier compared to the control group. Psycho physiological indices, reflecting the functioning of attention, decreased not only with aging but also with longer driving experience. Our results show that it is necessary to conduct further studies of psycho physiological markers of age-related decrease in short-term memory depending on the activities at work in order to prevent accelerated aging and achieve professional longevity.
H2B ubiquitination: Conserved molecular mechanism, diverse physiologic functions of the E3 ligase during meiosis.

PubMed

Wang, Liying; Cao, Chunwei; Wang, Fang; Zhao, Jianguo; Li, Wei

2017-09-03

RNF20/Bre1 mediated H2B ubiquitination (H2Bub) has various physiologic functions. Recently, we found that H2Bub participates in meiotic recombination by promoting chromatin relaxation during meiosis. We then analyzed the phylogenetic relationships among the E3 ligase for H2Bub, its E2 Rad6 and their partner WW domain-containing adaptor with a coiled-coil (WAC) or Lge1, and found that the molecular mechanism underlying H2Bub is evolutionarily conserved from yeast to mammals. However, RNF20 has diverse physiologic functions in different organisms, which might be caused by the evolutionary divergency of their domain/motif architectures. In the current extra view, we not only elucidate the evolutionarily conserved molecular mechanism underlying H2Bub, but also discuss the diverse physiologic functions of RNF20 during meiosis.
New Ways of Thinking about (and Teaching about) Intestinal Epithelial Function

ERIC Educational Resources Information Center

Barrett, Kim E.

2008-01-01

This article summarizes a presentation made at the Teaching Refresher Course of the American Physiological Society, which was held at the Experimental Biology meeting in 2007. The intestinal epithelium has important ion transport and barrier functions that contribute pivotally to normal physiological functioning of the intestine and other body…
Functional metabolite assemblies—a review

NASA Astrophysics Data System (ADS)

Aizen, Ruth; Tao, Kai; Rencus-Lazar, Sigal; Gazit, Ehud

2018-05-01

Metabolites are essential for the normal operation of cells and fulfill various physiological functions. It was recently found that in several metabolic disorders, the associated metabolites could self-assemble to generate amyloid-like structures, similar to canonical protein amyloids that have a role in neurodegenerative disorders. Yet, assemblies with typical amyloid characteristics are also known to have physiological function. In addition, many non-natural proteins and peptides presenting amyloidal properties have been used for the fabrication of functional nanomaterials. Similarly, functional metabolite assemblies are also found in nature, demonstrating various physiological roles. A notable example is the structural color formed by guanine crystals or fluorescent crystals in feline eyes responsible for enhanced night vision. Moreover, some metabolites have been used for the in vitro fabrication of functional materials, such as glycine crystals presenting remarkable piezoelectric properties or indigo films used to assemble organic semi-conductive electronic devices. Therefore, we believe that the study of metabolite assemblies is not only important in order to understand their role in normal physiology and in pathology, but also paves a new route in exploring the fabrication of organic, bio-compatible materials.
In Touch With the Mechanosensitive Piezo Channels: Structure, Ion Permeation, and Mechanotransduction.

PubMed

Geng, J; Zhao, Q; Zhang, T; Xiao, B

2017-01-01

Mechanotransduction, the conversion of mechanical forces into biological signals, plays critical roles in various physiological and pathophysiological processes in mammals, such as conscious sensing of touch, pain, and sound, as well as unconscious sensing of blood flow-associated shear stress, urine flow, and bladder distention. Among the various molecules involved in mechanotransduction, mechanosensitive (MS) cation channels have long been postulated to represent one critical class of mechanotransducers that directly and rapidly converts mechanical force into electrochemical signals. Despite the awareness of their functional significance, the molecular identities of MS cation channels in mammals had remained elusive for decades till the groundbreaking finding that the Piezo family of genes, including Piezo1 and Piezo2, constitutes their essential components. Since their identification about 6years ago, tremendous progress has been made in understanding their physiological and pathophysiological importance in mechanotransduction and their structure-function relationships of being the prototypic class of mammalian MS cation channels. On the one hand, Piezo proteins have been demonstrated to serve as physiologically and pathophysiologically important mechanotransducers for most, if not all, mechanotransduction processes. On the other hand, they have been shown to form a remarkable three-bladed, propeller-shaped homotrimeric channel complex comprising a separable ion-conducting pore module and mechanotransduction modules. In this chapter, we review the major advancements, with a particular focus on the structural and biophysical features that enable Piezo proteins to serve as sophisticated MS cation channels for force sensing, transduction, and ion conduction. Copyright © 2017 Elsevier Inc. All rights reserved.
Overwintering Is Associated with Reduced Expression of Immune Genes and Higher Susceptibility to Virus Infection in Honey Bees

PubMed Central

Steinmann, Nadja; Corona, Miguel; Neumann, Peter; Dainat, Benjamin

2015-01-01

The eusocial honey bee, Apis mellifera, has evolved remarkable abilities to survive extreme seasonal differences in temperature and availability of resources by dividing the worker caste into two groups that differ in physiology and lifespan: summer and winter bees. Most of the recent major losses of managed honey bee colonies occur during the winter, suggesting that winter bees may have compromised immune function and higher susceptibility to diseases. We tested this hypothesis by comparing the expression of eight immune genes and naturally occurring infection levels of deformed wing virus (DWV), one of the most widespread viruses in A. mellifera populations, between summer and winter bees. Possible interactions between immune response and physiological activity were tested by measuring the expression of vitellogenin and methyl farnesoate epoxidase, a gene coding for the last enzyme involved in juvenile hormone biosynthesis. Our data show that high DWV loads in winter bees correlate with reduced expression of genes involved in the cellular immune response and physiological activity and high expression of humoral immune genes involved in antibacterial defense compared with summer bees. This expression pattern could reflect evolutionary adaptations to resist bacterial pathogens and economize energy during the winter under a pathogen landscape with reduced risk of pathogenic viral infections. The outbreak of Varroa destructor infestation could have overcome these adaptations by promoting the transmission of viruses. Our results suggest that reduced cellular immune function during the winter may have increased honey bee’s susceptibility to DWV. These results contribute to our understanding of honey bee colony losses in temperate regions. PMID:26121358
Resolving the role of plant glutamate dehydrogenase: II. Physiological characterization of plants overexpressing the two enzyme subunits individually or simultaneously.

PubMed

Tercé-Laforgue, Thérèse; Bedu, Magali; Dargel-Grafin, Céline; Dubois, Frédéric; Gibon, Yves; Restivo, Francesco M; Hirel, Bertrand

2013-10-01

Glutamate dehydrogenase (GDH; EC 1.4.1.2) is able to carry out the deamination of glutamate in higher plants. In order to obtain a better understanding of the physiological function of GDH in leaves, transgenic tobacco (Nicotiana tabacum L.) plants were constructed that overexpress two genes from Nicotiana plumbaginifolia (GDHA and GDHB under the control of the Cauliflower mosiac virus 35S promoter), which encode the α- and β-subunits of GDH individually or simultaneously. In the transgenic plants, the GDH protein accumulated in the mitochondria of mesophyll cells and in the mitochondria of the phloem companion cells (CCs), where the native enzyme is normally expressed. Such a shift in the cellular location of the GDH enzyme induced major changes in carbon and nitrogen metabolite accumulation and a reduction in growth. These changes were mainly characterized by a decrease in the amount of sucrose, starch and glutamine in the leaves, which was accompanied by an increase in the amount of nitrate and Chl. In addition, there was an increase in the content of asparagine and a decrease in proline. Such changes may explain the lower plant biomass determined in the GDH-overexpressing lines. Overexpressing the two genes GDHA and GDHB individually or simultaneously induced a differential accumulation of glutamate and glutamine and a modification of the glutamate to glutamine ratio. The impact of the metabolic changes occurring in the different types of GDH-overexpressing plants is discussed in relation to the possible physiological function of each subunit when present in the form of homohexamers or heterohexamers.
Real-time magnetic resonance imaging of cardiac function and flow—recent progress

PubMed Central

Zhang, Shuo; Joseph, Arun A.; Voit, Dirk; Schaetz, Sebastian; Merboldt, Klaus-Dietmar; Unterberg-Buchwald, Christina; Hennemuth, Anja; Lotz, Joachim

2014-01-01

Cardiac structure, function and flow are most commonly studied by ultrasound, X-ray and magnetic resonance imaging (MRI) techniques. However, cardiovascular MRI is hitherto limited to electrocardiogram (ECG)-synchronized acquisitions and therefore often results in compromised quality for patients with arrhythmias or inabilities to comply with requested protocols—especially with breath-holding. Recent advances in the development of novel real-time MRI techniques now offer dynamic imaging of the heart and major vessels with high spatial and temporal resolution, so that examinations may be performed without the need for ECG synchronization and during free breathing. This article provides an overview of technical achievements, physiological validations, preliminary patient studies and translational aspects for a future clinical scenario of cardiovascular MRI in real time. PMID:25392819

Dynamics of biological systems: role of systems biology in medical research.

PubMed

Assmus, Heike E; Herwig, Ralf; Cho, Kwang-Hyun; Wolkenhauer, Olaf

2006-11-01

Cellular systems are networks of interacting components that change with time in response to external and internal events. Studying the dynamic behavior of these networks is the basis for an understanding of cellular functions and disease mechanisms. Quantitative time-series data leading to meaningful models can improve our knowledge of human physiology in health and disease, and aid the search for earlier diagnoses, better therapies and a healthier life. The advent of systems biology is about to take the leap into clinical research and medical applications. This review emphasizes the importance of a dynamic view and understanding of cell function. We discuss the potential for computer-aided mathematical modeling of biological systems in medical research with examples from some of the major therapeutic areas: cancer, cardiovascular, diabetic and neurodegenerative medicine.
Anismus: the cause of constipation? Results of investigation and treatment.

PubMed

Duthie, G S; Bartolo, D C

1992-01-01

Anismus, or failure of the somatic sphincter apparatus to relax at defecation, has been implicated as a major contributor to the problem of obstructed defecation. Current diagnostic methods depend on laboratory measurements of attempted defecation and the most complex, dynamic proctography has been the mainstay of diagnosis. Using a new computerized ambulatory method of recording sphincter function in these patients at home, we report an 80% reduction in our diagnostic rate suggesting that conventional tests fail to accurately diagnose this condition, probably because they poorly represent the natural physiology of defecation. Treatment of this distressing condition is more complex and a variety of surgical and pharmacological measures have failed. Biofeedback retraining of anorectal function of these patients has been very successful and represents the management of choice.
In Sickness and in Health: a Literature Review about Function of Social Support within Anxiety and Heart Disease Association

PubMed Central

Zarbo, Cristina; Compare, Angelo; Baldassari, Elena; Bonardi, Alberto; Romagnoni, Claudia

2013-01-01

A narrative review of the major evidence concerning the relationship between anxiety, social support and cardiac disease was conducted. Literature demonstrates that a strict relationship between anxiety, social support and cardiac disease outcomes subsists. However, the function of social support within anxiety and heart disease association remains unclear and needs to further researches to be established. Moreover evidence suggests that it’s the quality of close relationships to play an important role in affecting psychological and physiological health status. The main components that the literature suggests for a better quality of social support and close relationship, and the main assessment measure are presented. Evidence about cardiac rehabilitation programs and the need to assess and intervene on psychological and psychosocial factors is discussed. PMID:24403952
Bacterial Unculturability and the Formation of Intercellular Metabolic Networks.

PubMed

Pande, Samay; Kost, Christian

2017-05-01

The majority of known bacterial species cannot be cultivated under laboratory conditions. Here we argue that the adaptive emergence of obligate metabolic interactions in natural bacterial communities can explain this pattern. Bacteria commonly release metabolites into the external environment. Accumulating pools of extracellular metabolites create an ecological niche that benefits auxotrophic mutants, which have lost the ability to autonomously produce the corresponding metabolites. In addition to a diffusion-based metabolite transfer, auxotrophic cells can use contact-dependent means to obtain nutrients from other co-occurring cells. Spatial colocalisation and a continuous coevolution further increase the nutritional dependency and optimise fluxes through combined metabolic networks. Thus, bacteria likely function as networks of interacting cells that reciprocally exchange nutrients and biochemical functions rather than as physiologically autonomous units. Copyright © 2017 Elsevier Ltd. All rights reserved.
Distinct quantitative computed tomography emphysema patterns are associated with physiology and function in smokers.

PubMed

Castaldi, Peter J; San José Estépar, Raúl; Mendoza, Carlos S; Hersh, Craig P; Laird, Nan; Crapo, James D; Lynch, David A; Silverman, Edwin K; Washko, George R

2013-11-01

Emphysema occurs in distinct pathologic patterns, but little is known about the epidemiologic associations of these patterns. Standard quantitative measures of emphysema from computed tomography (CT) do not distinguish between distinct patterns of parenchymal destruction. To study the epidemiologic associations of distinct emphysema patterns with measures of lung-related physiology, function, and health care use in smokers. Using a local histogram-based assessment of lung density, we quantified distinct patterns of low attenuation in 9,313 smokers in the COPDGene Study. To determine if such patterns provide novel insights into chronic obstructive pulmonary disease epidemiology, we tested for their association with measures of physiology, function, and health care use. Compared with percentage of low-attenuation area less than -950 Hounsfield units (%LAA-950), local histogram-based measures of distinct CT low-attenuation patterns are more predictive of measures of lung function, dyspnea, quality of life, and health care use. These patterns are strongly associated with a wide array of measures of respiratory physiology and function, and most of these associations remain highly significant (P < 0.005) after adjusting for %LAA-950. In smokers without evidence of chronic obstructive pulmonary disease, the mild centrilobular disease pattern is associated with lower FEV1 and worse functional status (P < 0.005). Measures of distinct CT emphysema patterns provide novel information about the relationship between emphysema and key measures of physiology, physical function, and health care use. Measures of mild emphysema in smokers with preserved lung function can be extracted from CT scans and are significantly associated with functional measures.
Network Physiology: How Organ Systems Dynamically Interact

PubMed Central

Bartsch, Ronny P.; Liu, Kang K. L.; Bashan, Amir; Ivanov, Plamen Ch.

2015-01-01

We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS), we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems. PMID:26555073
Ginseng and obesity: observations and understanding in cultured cells, animals and humans.

PubMed

Zhang, Longyun; Virgous, Carlos; Si, Hongwei

2017-06-01

Ginseng, a traditional medical herb, has been reported having beneficial effects in fatigue, heart diseases, diabetes, immune function and erectile dysfunction. In recent years, increasing investigations have been conducted on ginseng in preventing and treating of obesity, one of the major worldwide escalating public health concerns. However, the effect and the relevant mechanisms behind how ginseng works as an antiobesity treatment are still controversial. In this review, we briefly discussed the chemical structures, metabolism and pharmacokinetics of ginseng and its major bioactive components ginsenosides. The major focus is on the antiobesity effects and the physiological, cellular and molecular mechanisms of ginseng and its ginsenosides in cultured cells, animal models and humans. We particularly compared the ginsenosides profiles, the antiobesity effects and the mechanisms between Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius), the two major ginseng species having opposite medical effects in traditional Chinese medicine. Our unpublished data on the ginseng antiobesity in cultured cells and mice were also included. We further addressed the current problems and future directions of the ginseng antiobesity research. Copyright © 2016 Elsevier Inc. All rights reserved.
Rational therapeutic choice for older patients with lymphoma.

PubMed

Bron, Dominique; Soubeyran, Pierre

2017-09-01

The choice for an optimal treatment in older lymphoma patients is a real challenge for hemato-oncologists. They have to treat a potentially curative lymphoma, and concomitantly protect their patients from unacceptable toxicities. Some recommendations are provided for the major subtypes of lymphomas including the antitumoral treatment and primarily the optimal supportive care. All the recent literature data converge to say that the approach of an older patient with a malignant hemopathy is a multistep procedure. This process comprises the appraisal of life expectancy of the patient with or without the disease, the prognostic factors of the tumor, the functional, physiological and cognitive functions evaluation, the socio-economical environment and the patient's expectancy in terms of quality of life. Major progresses have been achieved in the management of diffuse large B cell lymphoma and mantle cell lymphoma in patients up to 80 and above 80 years old. With all these information in hands, the hematologist will decide if the treatment's objective is the standard treatment with optimal supportive care (fit patients), tailor-made adapted chemotherapy (unfit patients) or preservation of quality of life (frail patients).
Glucocorticoid hormones are both a major circadian signal and major stress signal: How this shared signal contributes to a dynamic relationship between the circadian and stress systems.

PubMed

Spencer, Robert L; Chun, Lauren E; Hartsock, Matthew J; Woodruff, Elizabeth R

2018-04-01

Glucocorticoid hormones are a powerful mammalian systemic hormonal signal that exerts regulatory effects on almost every cell and system of the body. Glucocorticoids act in a circadian and stress-directed manner to aid in adaptation to an ever-changing environment. Circadian glucocorticoid secretion provides for a daily waxing and waning influence on target cell function. In addition, the daily circadian peak of glucocorticoid secretion serves as a timing signal that helps entrain intrinsic molecular clock phase in tissue cells distributed throughout the body. Stress-induced glucocorticoid secretion also modulates the state of these same cells in response to both physiological and psychological stressors. We review the strong functional interrelationships between glucocorticoids and the circadian system, and discuss how these interactions optimize the appropriate cellular and systems response to stress throughout the day. We also discuss clinical implications of this dual aspect of glucocorticoid signaling, especially for conditions of circadian and HPA axis dysregulation. Copyright © 2018 Elsevier Inc. All rights reserved.
[Learning and memory in Drosophila: physiologic and genetic bases].

PubMed

Zhuravlev, A V; Nikitina, E A; Savvateeva-Popova, E V

2015-01-01

Elucidation of molecular mechanisms of cognitive functions is one of the major achievements in neurobiology. At most, this is due to the studies on the simple nervous systems, such as the CNS in Drosophila melanogaster. Many of its functional characteristics are pretty similar to higher vertebrates. Among these are: 1) evolutionary conservation of genes and molecular systems involved in the regulation of learning acquisition and memory formation; 2) presence of highly specialized and differentiated sensory, associative and motor centers; 3) utilization of similar modes of informational coding and analysis; 4) availability of major learning forms including non-associative, as well as associative learning; 5) diversity of different memories, including short-term- and protein synthesis- dependent long-term memory; 6) presence of aminergic reinforcement systems in the brain; 7) feed-back loops of circadian clocks, current organism experience and individual organism characters affecting cognitive process per se. In this review the main attention is paid to the two mostly studied Drosophila learning forms, namely to olfactory Iearning and courtship suppression conditioning (CCS). A separate consideration is given to the impacts of kynurenins and metabolite of actin remodeling signal cascade.
ABCdb: an online resource for ABC transporter repertories from sequenced archaeal and bacterial genomes.

PubMed

Fichant, Gwennaele; Basse, Marie-Jeanne; Quentin, Yves

2006-03-01

The ATP-binding cassette (ABC) transporters are one of the major classes of active transporters. They are widespread in archaea, bacteria, and eukaryota, indicating that they have arisen early in evolution. They are involved in many essential physiological processes, but the majority import or export a wide variety of compounds across cellular membranes. These systems share a common architecture composed of four (exporters) or five (importers) domains. To identify and reconstruct functional ABC transporters encoded by archaeal and bacterial genomes, we have developed a bioinformatic strategy. Cross-reference to the transport classification system is used to predict the type of compound transported. A high quality of annotation is achieved by manual verification of the predictions. However, in order to face the rapid increase in the number of published genomes, we also include analyses of genomes issuing directly from the automated strategy. Querying the database (http://www-abcdb.biotoul.fr) allows to easily retrieve ABC transporter repertories and related data. Additional query tools have been developed for the analysis of the ABC family from both functional and evolutionary perspectives.
Insect photoreceptor adaptations to night vision

PubMed Central

Honkanen, Anna; Salmela, Iikka; Weckström, Matti

2017-01-01

Night vision is ultimately about extracting information from a noisy visual input. Several species of nocturnal insects exhibit complex visually guided behaviour in conditions where most animals are practically blind. The compound eyes of nocturnal insects produce strong responses to single photons and process them into meaningful neural signals, which are amplified by specialized neuroanatomical structures. While a lot is known about the light responses and the anatomical structures that promote pooling of responses to increase sensitivity, there is still a dearth of knowledge on the physiology of night vision. Retinal photoreceptors form the first bottleneck for the transfer of visual information. In this review, we cover the basics of what is known about physiological adaptations of insect photoreceptors for low-light vision. We will also discuss major enigmas of some of the functional properties of nocturnal photoreceptors, and describe recent advances in methodologies that may help to solve them and broaden the field of insect vision research to new model animals. This article is part of the themed issue ‘Vision in dim light’. PMID:28193821
Bayesian parameter estimation for stochastic models of biological cell migration

NASA Astrophysics Data System (ADS)

Dieterich, Peter; Preuss, Roland

2013-08-01

Cell migration plays an essential role under many physiological and patho-physiological conditions. It is of major importance during embryonic development and wound healing. In contrast, it also generates negative effects during inflammation processes, the transmigration of tumors or the formation of metastases. Thus, a reliable quantification and characterization of cell paths could give insight into the dynamics of these processes. Typically stochastic models are applied where parameters are extracted by fitting models to the so-called mean square displacement of the observed cell group. We show that this approach has several disadvantages and problems. Therefore, we propose a simple procedure directly relying on the positions of the cell's trajectory and the covariance matrix of the positions. It is shown that the covariance is identical with the spatial aging correlation function for the supposed linear Gaussian models of Brownian motion with drift and fractional Brownian motion. The technique is applied and illustrated with simulated data showing a reliable parameter estimation from single cell paths.
Effects of Caffeine on Olfactory Learning in Crickets.

PubMed

Sugimachi, Seigo; Matsumoto, Yukihisa; Mizunami, Makoto; Okada, Jiro

2016-10-01

Caffeine is a plant-derived alkaloid that is generally known as a central nervous system (CNS) stimulant. In order to examine the effects of caffeine on higher CNS functions in insects, we used an appetitive olfactory learning paradigm for the cricket Gryllus bimaculatus. Crickets can form significant long-term memories (LTMs) after repetitive training sessions, during which they associate a conditioned stimulus (CS: odor) with an unconditioned stimulus (US: reward). Administration of hemolymphal injections of caffeine established LTM after only single-trial conditioning over a wide range of caffeine dosages (1.6 µµg/kg to 39 mg/kg). We investigated the physiological mechanisms underlying this enhancement of olfactory learning performance pharmacologically, focusing on three major physiological roles of caffeine: 1) inhibition of phosphodiesterase (PDE), 2) agonism of ryanodine receptors, and 3) antagonism of adenosine receptors. Application of drugs relevant to these actions resulted in significant effects on LTM formation. These results suggest that externally applied caffeine enhances LTM formation in insect olfactory learning via multiple cellular mechanisms.
Mapping oxygen concentration in the awake mouse brain

PubMed Central

Lyons, Declan G; Parpaleix, Alexandre; Roche, Morgane; Charpak, Serge

2016-01-01

Although critical for brain function, the physiological values of cerebral oxygen concentration have remained elusive because high-resolution measurements have only been performed during anesthesia, which affects two major parameters modulating tissue oxygenation: neuronal activity and blood flow. Using measurements of capillary erythrocyte-associated transients, fluctuations of oxygen partial pressure (Po2) associated with individual erythrocytes, to infer Po2 in the nearby neuropil, we report the first non-invasive micron-scale mapping of cerebral Po2 in awake, resting mice. Interstitial Po2 has similar values in the olfactory bulb glomerular layer and the somatosensory cortex, whereas there are large capillary hematocrit and erythrocyte flux differences. Awake tissue Po2 is about half that under isoflurane anesthesia, and within the cortex, vascular and interstitial Po2 values display layer-specific differences which dramatically contrast with those recorded under anesthesia. Our findings emphasize the importance of measuring energy parameters non-invasively in physiological conditions to precisely quantify and model brain metabolism. DOI: http://dx.doi.org/10.7554/eLife.12024.001 PMID:26836304
Antioxidant Systems are Regulated by Nitric Oxide-Mediated Post-translational Modifications (NO-PTMs)

PubMed Central

Begara-Morales, Juan C.; Sánchez-Calvo, Beatriz; Chaki, Mounira; Valderrama, Raquel; Mata-Pérez, Capilla; Padilla, María N.; Corpas, Francisco J.; Barroso, Juan B.

2016-01-01

Nitric oxide (NO) is a biological messenger that orchestrates a plethora of plant functions, mainly through post-translational modifications (PTMs) such as S-nitrosylation or tyrosine nitration. In plants, hundreds of proteins have been identified as potential targets of these NO-PTMs under physiological and stress conditions indicating the relevance of NO in plant-signaling mechanisms. Among these NO protein targets, there are different antioxidant enzymes involved in the control of reactive oxygen species (ROS), such as H2O2, which is also a signal molecule. This highlights the close relationship between ROS/NO signaling pathways. The major plant antioxidant enzymes, including catalase, superoxide dismutases (SODs) peroxiredoxins (Prx) and all the enzymatic components of the ascorbate-glutathione (Asa-GSH) cycle, have been shown to be modulated to different degrees by NO-PTMs. This mini-review will update the recent knowledge concerning the interaction of NO with these antioxidant enzymes, with a special focus on the components of the Asa-GSH cycle and their physiological relevance. PMID:26909095
Mapping oxygen concentration in the awake mouse brain.

PubMed

Lyons, Declan G; Parpaleix, Alexandre; Roche, Morgane; Charpak, Serge

2016-02-02

Although critical for brain function, the physiological values of cerebral oxygen concentration have remained elusive because high-resolution measurements have only been performed during anesthesia, which affects two major parameters modulating tissue oxygenation: neuronal activity and blood flow. Using measurements of capillary erythrocyte-associated transients, fluctuations of oxygen partial pressure (Po2) associated with individual erythrocytes, to infer Po2 in the nearby neuropil, we report the first non-invasive micron-scale mapping of cerebral Po2 in awake, resting mice. Interstitial Po2 has similar values in the olfactory bulb glomerular layer and the somatosensory cortex, whereas there are large capillary hematocrit and erythrocyte flux differences. Awake tissue Po2 is about half that under isoflurane anesthesia, and within the cortex, vascular and interstitial Po2 values display layer-specific differences which dramatically contrast with those recorded under anesthesia. Our findings emphasize the importance of measuring energy parameters non-invasively in physiological conditions to precisely quantify and model brain metabolism.
Beyond cellular detoxification: a plethora of physiological roles for MDR transporter homologs in plants

PubMed Central

Remy, Estelle; Duque, Paula

2014-01-01

Higher plants possess a multitude of Multiple Drug Resistance (MDR) transporter homologs that group into three distinct and ubiquitous families—the ATP-Binding Cassette (ABC) superfamily, the Major Facilitator Superfamily (MFS), and the Multidrug And Toxic compound Extrusion (MATE) family. As in other organisms, such as fungi, mammals, and bacteria, MDR transporters make a primary contribution to cellular detoxification processes in plants, mainly through the extrusion of toxic compounds from the cell or their sequestration in the central vacuole. This review aims at summarizing the currently available information on the in vivo roles of MDR transporters in plant systems. Taken together, these data clearly indicate that the biological functions of ABC, MFS, and MATE carriers are not restricted to xenobiotic and metal detoxification. Importantly, the activity of plant MDR transporters also mediates biotic stress resistance and is instrumental in numerous physiological processes essential for optimal plant growth and development, including the regulation of ion homeostasis and polar transport of the phytohormone auxin. PMID:24910617
A critical review of 5-HT brain microdialysis and behavior.

PubMed

Rueter, L E; Fornal, C A; Jacobs, B L

1997-01-01

Serotonin (5-HT) has been implicated in many central nervous system-mediated functions including sleep, arousal, feeding, motor activity and the stress response. In order to help establish the precise role of 5-HT in physiology and behavior, in vivo microdialysis studies have sought to identify the conditions under which the release of 5-HT is altered. Extracellular 5-HT levels have been monitored in more than fifteen regions of the brain during a variety of spontaneous behaviors, and in response to several physiological, environmental, and behavioral manipulations. The vast majority of these studies found increases (30-100%) in 5-HT release in almost all brain regions studied. Since electrophysiological studies have shown that behavioral arousal is the primary determinant of brain serotonergic neuronal activity, we suggest that the increase in 5-HT release seen during a wide variety of experimental conditions is largely due to one factor, namely an increase in behavioral arousal/motor activity associated with the manipulation.
Polyunsaturated Fatty Acids in Children

PubMed Central

2013-01-01

Polyunsaturated fatty acids (PUFAs) are the major components of brain and retina, and are the essential fatty acids with important physiologically active functions. Thus, PUFAs should be provided to children, and are very important in the brain growth and development for fetuses, newborn infants, and children. Omega-3 fatty acids decrease coronary artery disease and improve blood flow. PUFAs have been known to have anti-inflammatory action and improved the chronic inflammation such as auto-immune diseases or degenerative neurologic diseases. PUFAs are used for metabolic syndrome related with obesity or diabetes. However, there are several considerations related with intake of PUFAs. Obsession with the intake of unsaturated fatty acids could bring about the shortage of essential fatty acids that are crucial for our body, weaken the immune system, and increase the risk of heart disease, arrhythmia, and stroke. In this review, we discuss types, physiologic mechanism of action of PUFAs, intake of PUFAs for children, recommended intake of PUFAs, and considerations for the intake of PUFAs. PMID:24224148

MECHANICS OF THE LUNG IN THE 20TH CENTURY

PubMed Central

Mitzner, Wayne

2015-01-01

Major advances in respiratory mechanics occurred primarily in the latter half of the 20th century, and this is when much of our current understanding was secured. The earliest and ancient investigations involving respiratory physiology and mechanics were often done in conjunction with other scientific activities and often lacked the ability to make quantitative measurements. This situation changed rapidly in the 20th century, and this relatively recent history of lung mechanics has been greatly influenced by critical technological advances and applications, which have made quantitative experimental testing of ideas possible. From the spirometer of Hutchinson, to the pneumotachograph of Fleisch, to the measurement of esophageal pressure, to the use of the Wilhelmy balance by Clements, to the unassuming strain gauges for measuring pressure and rapid paper and electronic chart recorders, these enabling devices have generated numerous quantitative experimental studies with greatly increased physiologic understanding and validation of mechanistic theories of lung function in health and disease. PMID:23733695
Physiological and biochemical perspectives of non-salt tolerant plants during bacterial interaction against soil salinity.

PubMed

Radhakrishnan, Ramalingam; Baek, Kwang Hyun

2017-07-01

Climatic changes on earth affect the soil quality of agricultural lands, especially by increasing salt deposition in soil, which results in soil salinity. Soil salinity is a major challenge to growth and reproduction among glycophytes (including all crop plants). Soil bacteria present in the rhizosphere and/or roots naturally protect plants from the adverse effects of soil salinity by reprogramming the stress-induced physiological changes in plants. Bacteria can enrich the soil with major nutrients (nitrogen, phosphorus, and potassium) in a form easily available to plants and prevent the transport of excess sodium to roots (exopolysaccharides secreted by bacteria bind with sodium ions) for maintaining ionic balance and water potential in cells. Salinity also affects plant growth regulators and suppresses seed germination and root and shoot growth. Bacterial secretion of indole-3-acetic acid and gibberellins compensates for the salt-induced hormonal decrease in plants, and bacterial 1-aminocyclopropane-1-carboxylate (ACC) deaminase synthesis decreases ethylene production to stimulate plant growth. Furthermore, bacteria modulate the redox state of salinity-affected plants by enhancing antioxidants and polyamines, which leads to increased photosynthetic efficiency. Bacteria-induced accumulation of compatible solutes in stressed plants regulates plant cellular activities and prevents salt stress damage. Plant-bacterial interaction reprograms the expression of salt stress-responsive genes and proteins in salinity-affected plants, resulting in a precise stress mitigation metabolism as a defense mechanism. Soil bacteria increase the fertility of soil and regulate the plant functions to prevent the salinity effects in glycophytes. This review explains the current understanding about the physiological changes induced in glycophytes during bacterial interaction to alleviate the adverse effects of soil salinity stress. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Studies on functional foods in Japan--state of the art.

PubMed

Arai, S

1996-01-01

This paper pinpoints the "tertiary" function of foods which, different from the conventional "primary" and "secondary" functions that are related to nutrition and preference, respectively, is understood to be directly involved in the modulation of our physiological systems such as the immune, endocrine, nerve, circulatory, and digestive systems. Insights into this newly defined function are particularly important in that the intake of some physiologically functional constituents of foods could be effective in preventing diseases that may be caused by disorders in these physiological systems. Technologically, it has become feasible to design and produce physiologically functional foods (simply, functional foods) that are expected to satisfy in whole or in part a today's demand for disease prevention by eating. Such public expectations are reflected in the activation and development of systematic, large-scale studies on foods as seen in "Grant-in-Aid" research sponsored by the Ministry of Education, Science, and Culture. Meanwhile, the Ministry of Health and Welfare has initiated a policy of officially approving functional foods in terms of "foods for specified health uses" as defined by new legislation. Up to now (October 1995), 58 items have thus been approved. The first was a hypoallergenic rice product approved as of June 1, 1993. Here I discuss details of studies on rice-based functional foods. Other basic and applied studies directed toward the tertiary function, with future perspectives for functional foods, are also discussed.
Plant-based Paste Fermented by Lactic Acid Bacteria and Yeast: Functional Analysis and Possibility of Application to Functional Foods

PubMed Central

Kuwaki, Shinsuke; Nakajima, Nobuyoshi; Tanaka, Hidehiko; Ishihara, Kohji

2012-01-01

A plant-based paste fermented by lactic acid bacteria and yeast (fermented paste) was made from various plant materials. The paste was made of fermented food by applying traditional food-preservation techniques, that is, fermentation and sugaring. The fermented paste contained major nutrients (carbohydrates, proteins, and lipids), 18 kinds of amino acids, and vitamins (vitamin A, B1, B2, B6, B12, E, K, niacin, biotin, pantothenic acid, and folic acid). It contained five kinds of organic acids, and a large amount of dietary fiber and plant phytochemicals. Sucrose from brown sugar, used as a material, was completely resolved into glucose and fructose. Some physiological functions of the fermented paste were examined in vitro. It was demonstrated that the paste possessed antioxidant, antihypertensive, antibacterial, anti-inflammatory, anti-allergy and anti-tyrosinase activities in vitro. It was thought that the fermented paste would be a helpful functional food with various nutrients to help prevent lifestyle diseases. PMID:25114554
Cholesterol in brain disease: sometimes determinant and frequently implicated

PubMed Central

Martín, Mauricio G; Pfrieger, Frank; Dotti, Carlos G

2014-01-01

Cholesterol is essential for neuronal physiology, both during development and in the adult life: as a major component of cell membranes and precursor of steroid hormones, it contributes to the regulation of ion permeability, cell shape, cell–cell interaction, and transmembrane signaling. Consistently, hereditary diseases with mutations in cholesterol-related genes result in impaired brain function during early life. In addition, defects in brain cholesterol metabolism may contribute to neurological syndromes, such as Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD), and even to the cognitive deficits typical of the old age. In these cases, brain cholesterol defects may be secondary to disease-causing elements and contribute to the functional deficits by altering synaptic functions. In the first part of this review, we will describe hereditary and non-hereditary causes of cholesterol dyshomeostasis and the relationship to brain diseases. In the second part, we will focus on the mechanisms by which perturbation of cholesterol metabolism can affect synaptic function. PMID:25223281
Polyploidy and the relationship between leaf structure and function: implications for correlated evolution of anatomy, morphology, and physiology in Brassica.

PubMed

Baker, Robert L; Yarkhunova, Yulia; Vidal, Katherine; Ewers, Brent E; Weinig, Cynthia

2017-01-05

Polyploidy is well studied from a genetic and genomic perspective, but the morphological, anatomical, and physiological consequences of polyploidy remain relatively uncharacterized. Whether these potential changes bear on functional integration or are idiosyncratic remains an open question. Repeated allotetraploid events and multiple genomic combinations as well as overlapping targets of artificial selection make the Brassica triangle an excellent system for exploring variation in the connection between plant structure (anatomy and morphology) and function (physiology). We examine phenotypic integration among structural aspects of leaves including external morphology and internal anatomy with leaf-level physiology among several species of Brassica. We compare diploid and allotetraploid species to ascertain patterns of phenotypic correlations among structural and functional traits and test the hypothesis that allotetraploidy results in trait disintegration allowing for transgressive phenotypes and additional evolutionary and crop improvement potential. Among six Brassica species, we found significant effects of species and ploidy level for morphological, anatomical and physiological traits. We identified three suites of intercorrelated traits in both diploid parents and allotetraploids: Morphological traits (such as leaf area and perimeter) anatomic traits (including ab- and ad- axial epidermis) and aspects of physiology. In general, there were more correlations between structural and functional traits for allotetraploid hybrids than diploid parents. Parents and hybrids did not have any significant structure-function correlations in common. Of particular note, there were no significant correlations between morphological structure and physiological function in the diploid parents. Increased phenotypic integration in the allotetraploid hybrids may be due, in part, to increased trait ranges or simply different structure-function relationships. Genomic and chromosomal instability in early generation allotetraploids may allow Brassica species to explore new trait space and potentially reach higher adaptive peaks than their progenitor species could, despite temporary fitness costs associated with unstable genomes. The trait correlations that disappear after hybridization as well as the novel trait correlations observed in allotetraploid hybrids may represent relatively evolutionarily labile associations and therefore could be ideal targets for artificial selection and crop improvement.
The hypocretins/orexins: integrators of multiple physiological functions

PubMed Central

Li, Jingcheng; Hu, Zhian; Lecea, Luis

2014-01-01

The hypocretins (Hcrts), also known as orexins, are two peptides derived from a single precursor produced in the posterior lateral hypothalamus. Over the past decade, the orexin system has been associated with numerous physiological functions, including sleep/arousal, energy homeostasis, endocrine, visceral functions and pathological states, such as narcolepsy and drug abuse. Here, we review the discovery of Hcrt/orexins and their receptors and propose a hypothesis as to how the orexin system orchestrates these multifaceted physiological functions. Linked ArticlesThis article is part of a themed section on Orexin Receptors. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-2 PMID:24102345
Differential and brain region-specific regulation of Rap-1 and Epac in depressed suicide victims.

PubMed

Dwivedi, Yogesh; Mondal, Amal C; Rizavi, Hooriyah S; Faludi, Gabor; Palkovits, Miklos; Sarosi, Andrea; Conley, Robert R; Pandey, Ghanshyam N

2006-06-01

Depression is a major public health problem. Despite many years of research, the molecular mechanisms associated with depression remain unclear. Rap-1, activated in response to many extracellular stimuli, is one of the major substrates of protein kinase A, which participates in myriad physiologic functions in the brain, including cell survival and synaptic plasticity. Rap-1 is also activated directly by cyclic adenosine monophosphate through Epac, and thus participates in mediating physiologic functions independent of protein kinase A. To examine whether the pathogenesis of depression is associated with altered activation and expression of Rap-1, as well as expression of Epac, in depressed suicide victims. Postmortem study. Tissues were obtained from the Lenhossek Human Brain Program, Semmelweis University, Budapest, Hungary, and the Brain Collection Program of the Maryland Psychiatric Research Center, Baltimore. Postmortem brains of 28 depressed suicide victims and 28 nonpsychiatric control subjects. Examination of brain tissues. Rap-1 activation as well as messenger RNA and protein levels of Rap-1 and Epac in prefrontal cortex, hippocampus, and cerebellum. Rap-1 activation was significantly reduced (P<.001) in prefrontal cortex and hippocampus in the suicide group. This was associated with significant reductions in Rap-1 messenger RNA and protein levels (P<.001). In contrast, protein level of only Epac-2 (P<.001) but not Epac-1 (P = .89) was significantly increased in prefrontal cortex and hippocampus of these subjects. These changes were present whether the 2 cohorts were analyzed together or separately. None of the measures showed any significant change in cerebellum in the suicide group. Given the importance of Rap-1 in neuroprotection and synaptic plasticity, our findings of differential regulation of Rap-1 and Epac between brain regions suggest the relevance of these molecules in the pathophysiology of depression.
RNAi inhibition of feruloyl CoA 6'-hydroxylase reduces scopoletin biosynthesis and post-harvest physiological deterioration in cassava (Manihot esculenta Crantz) storage roots.

PubMed

Liu, Shi; Zainuddin, Ima M; Vanderschuren, Herve; Doughty, James; Beeching, John R

2017-05-01

Cassava (Manihot esculenta Crantz) is a major world crop, whose storage roots provide food for over 800 million throughout the humid tropics. Despite many advantages as a crop, the development of cassava is seriously constrained by the rapid post-harvest physiological deterioration (PPD) of its roots that occurs within 24-72 h of harvest, rendering the roots unpalatable and unmarketable. PPD limits cassava's marketing possibilities in countries that are undergoing increased development and urbanisation due to growing distances between farms and consumers. The inevitable wounding of the roots caused by harvesting triggers an oxidative burst that spreads throughout the cassava root, together with the accumulation of secondary metabolites including phenolic compounds, of which the coumarin scopoletin (7-hydroxy-6-methoxy-2H-1-benzopyran-2-one) is the most abundant. Scopoletin oxidation yields a blue-black colour, which suggests its involvement in the discoloration observed during PPD. Feruloyl CoA 6'-hydroxylase is a controlling enzyme in the biosynthesis of scopoletin. The cassava genome contains a seven membered family of feruloyl CoA 6'-hydroxylase genes, four of which are expressed in the storage root and, of these, three were capable of functionally complementing Arabidopsis T-DNA insertion mutants in this gene. A RNA interference construct, designed to a highly conserved region of these genes, was used to transform cassava, where it significantly reduced feruloyl CoA 6'-hydroxylase gene expression, scopoletin accumulation and PPD symptom development. Collectively, our results provide evidence that scopoletin plays a major functional role in the development of PPD symptoms, rather than merely paralleling symptom development in the cassava storage root.
Non-protein thiol imaging and quantification in live cells with a novel benzofurazan sulfide triphenylphosphonium fluorogenic compound.

PubMed

Yang, Yang; Guan, Xiangming

2017-05-01

Thiols (-SH) play various roles in biological systems. They are divided into protein thiols (PSH) and non-protein thiols (NPSH). Due to the significant roles thiols play in various physiological/pathological functions, numerous analytical methods have been developed for thiol assays. Most of these methods are developed for glutathione, the major form of NPSH. Majority of these methods require tissue/cell homogenization before analysis. Due to a lack of effective thiol-specific fluorescent/fluorogenic reagents, methods for imaging and quantifying thiols in live cells are limited. Determination of an analyte in live cells can reveal information that cannot be revealed by analysis of cell homogenates. Previously, we reported a thiol-specific thiol-sulfide exchange reaction. Based on this reaction, a benzofurazan sulfide thiol-specific fluorogenic reagent was developed. The reagent was able to effectively image and quantify total thiols (PSH+NPSH) in live cells through fluorescence microscopy. The reagent was later named as GUALY's reagent. Here we would like to report an extension of the work by synthesizing a novel benzofurazan sulfide triphenylphosphonium derivative [(((7,7'-thiobis(benzo[c][1,2,5]oxadiazole-4,4'-sulfonyl))bis(methylazanediyl))bis(butane-4,1-diyl))bis(triphenylphosphonium) (TBOP)]. Like GUALY's reagent, TBOP is a thiol-specific fluorogenic agent that is non-fluorescent but forms fluorescent thiol adducts in a thiol-specific fashion. Different than GUALY's reagent, TBOP reacts only with NPSH but not with PSH. TBOP was effectively used to image and quantify NPSH in live cells using fluorescence microscopy. TBOP is a complementary reagent to GUALY's reagent in determining the roles of PSH, NPSH, and total thiols in thiol-related physiological/pathological functions in live cells through fluorescence microscopy. Graphical Abstract Live cell imaging and quantification of non-protein thiols by TBOP.
Mother-child adrenocortical synchrony; Moderation by dyadic relational behavior.

PubMed

Pratt, Maayan; Apter-Levi, Yael; Vakart, Adam; Kanat-Maymon, Yaniv; Zagoory-Sharon, Orna; Feldman, Ruth

2017-03-01

Mother-child adrenocortical synchrony, the coupling of cortisol (CT) secretion in mother and child, has been associated with shared parent-child experiences and maladaptive familial contexts. Yet, few studies tested adrenocortical synchrony in diurnal CT patterns. Guided by the bio-behavioral synchrony model, we examined whether mother-child relational behavior and maternal psychopathology may moderate the degree of concordance between mother and child's diurnal CT. Ninety-seven mothers and their six-year old children participated in two groups; mothers diagnosed with major depression disorder (N=28) and non-depressed controls (N=69). Mother-child interactions were observed and coded for dyadic reciprocity and dyadic tension and diurnal cortisol was collected from mother and child over two consecutive weekend days. Concordance between maternal and child's diurnal CT was found, significant above and beyond time of measurement. Maternal depression, while associated with attenuated child diurnal CT variability, was unrelated to adrenocortical synchrony. Higher child diurnal CT production predicted a stronger linkage between maternal and child's diurnal CT, suggesting that greater child physiological stress is associated with increased susceptibility to the influences of maternal stress physiology. Mother-child reciprocity was related to lower adrenocortical synchrony. Findings suggest that higher adrenocortical synchrony is associated with greater physiological stress and less adaptive dyadic relational patterns. Results raise the possibility that diurnal adrenocortical synchrony taps a unique aspect of HPA-axis functioning whose role in the cross-generational transfer of stress physiology requires further research. Copyright © 2017 Elsevier Inc. All rights reserved.
Cortisol and DHEA in development and psychopathology.

PubMed

Kamin, Hayley S; Kertes, Darlene A

2017-03-01

Dehydroepiandrosterone (DHEA) and cortisol are the most abundant hormones of the human fetal and adult adrenals released as end products of a tightly coordinated endocrine response to stress. Together, they mediate short- and long-term stress responses and enable physiological and behavioral adjustments necessary for maintaining homeostasis. Detrimental effects of chronic or repeated elevations in cortisol on behavioral and emotional health are well documented. Evidence for actions of DHEA that offset or oppose those of cortisol has stimulated interest in examining their levels as a ratio, as an alternate index of adrenocortical activity and the net effects of cortisol. Such research necessitates a thorough understanding of the co-actions of these hormones on physiological functioning and in association with developmental outcomes. This review addresses the state of the science in understanding the role of DHEA, cortisol, and their ratio in typical development and developmental psychopathology. A rationale for studying DHEA and cortisol in concert is supported by physiological data on the coordinated synthesis and release of these hormones in the adrenal and by their opposing physiological actions. We then present evidence that researching cortisol and DHEA necessitates a developmental perspective. Age-related changes in DHEA and cortisol are described from the perinatal period through adolescence, along with observed associations of these hormones with developmental psychopathology. Along the way, we identify several major knowledge gaps in the role of DHEA in modulating cortisol in typical development and developmental psychopathology with implications for future research. Copyright © 2016 Elsevier Inc. All rights reserved.
Binding of trivalent chromium to serum transferrin is sufficiently rapid to be physiologically relevant.

PubMed

Deng, Ge; Wu, Kristi; Cruce, Alex A; Bowman, Michael K; Vincent, John B

2015-02-01

Transferrin, the major iron transport protein in the blood, also transports trivalent chromium in vivo. Recent in vitro studies have, however, suggested that the binding of chromic ions to apotransferrin is too slow to be biologically relevant. Nevertheless, the in vitro studies have generally failed to adequately take physiological bicarbonate concentrations into account. In aqueous buffer (with ambient (bi)carbonate concentrations), the binding of chromium to transferrin is too slow to be physiologically relevant, taking days to reach equilibrium with the protein's associated conformational changes. However, in the presence of 25mM (bi)carbonate, the concentration in human blood, chromic ions bind rapidly and tightly to transferrin. Details of the kinetics of chromium binding to human serum transferrin and conalbumin (egg white transferrin) in the presence of bicarbonate and other major potential chromium ligands are described and are consistent with transferrin being the major chromic ion transporter from the blood to tissues. Copyright © 2014 Elsevier Inc. All rights reserved.
Adaptive style and physiological reactivity during a laboratory stress paradigm in children with cancer and healthy controls.

PubMed

Williams, Natalie A; Allen, Michael T; Phipps, Sean

2011-10-01

Repressive adaptation has been conceptualized as one pathway to psychological resilience in children with cancer, but the physiological costs of maintaining a repressive adaptive style are currently unknown. The goal of this study was to examine physiological functioning as a function of adaptive style in children with cancer (N = 120) and healthy controls (N = 120). Children completed self-report measures of state anxiety and defensiveness prior to participating in three verbal stress tasks while monitoring blood pressure, electrocardiogram, and electrodermal response, and rated their anxiety following each task. Findings indicated no consistent differences in baseline indices and physiological reactivity as a function of adaptive style or health status (cancer vs. control). In addition, children identified as having a repressive adaptive style did not exhibit greater verbal-autonomic discrepancy than low-anxious children. In contrast to findings with adults, children with a repressive adaptive style do not appear to experience adverse effects of this coping style in terms of physiological reactivity.
Functional Task Test (FTT)

NASA Technical Reports Server (NTRS)

Bloomberg, Jacob J.; Mulavara, Ajitkumar; Peters, Brian T.; Rescheke, Millard F.; Wood, Scott; Lawrence, Emily; Koffman, Igor; Ploutz-Snyder, Lori; Spiering, Barry A.; Feeback, Daniel L.;

2009-01-01

This slide presentation reviews the Functional Task Test (FTT), an interdisciplinary testing regimen that has been developed to evaluate astronaut postflight functional performance and related physiological changes. The objectives of the project are: (1) to develop a set of functional tasks that represent critical mission tasks for the Constellation Program, (2) determine the ability to perform these tasks after space flight, (3) Identify the key physiological factors that contribute to functional decrements and (4) Use this information to develop targeted countermeasures.

Measuring dynamic kidney function in an undergraduate physiology laboratory.

PubMed

Medler, Scott; Harrington, Frederick

2013-12-01

Most undergraduate physiology laboratories are very limited in how they treat renal physiology. It is common to find teaching laboratories equipped with the capability for high-resolution digital recordings of physiological functions (muscle twitches, ECG, action potentials, respiratory responses, etc.), but most urinary laboratories still rely on a "dipstick" approach of urinalysis. Although this technique can provide some basic insights into the functioning of the kidneys, it overlooks the dynamic processes of filtration, reabsorption, and secretion. In the present article, we provide a straightforward approach of using renal clearance measurements to estimate glomerular filtration rate, fractional water reabsorption, glucose clearance, and other physiologically relevant parameters. The estimated values from our measurements in laboratory are in close agreement with those anticipated based on textbook parameters. For example, we found glomerular filtration rate to average 124 ± 45 ml/min, serum creatinine to be 1.23 ± 0.4 mg/dl, and fractional water reabsorption to be ∼96.8%. Furthermore, analyses for the class data revealed significant correlations between parameters like fractional water reabsorption and urine concentration, providing opportunities to discuss urine concentrating mechanisms and other physiological processes. The procedures outlined here are general enough that most undergraduate physiology laboratory courses should be able to implement them without difficulty.
Molecular and biological hallmarks of ageing.

PubMed

Aunan, J R; Watson, M M; Hagland, H R; Søreide, K

2016-01-01

Ageing is the inevitable time-dependent decline in physiological organ function that eventually leads to death. Age is a major risk factor for many of the most common medical conditions, such as cardiovascular disease, cancer, diabetes and Alzheimer's disease. This study reviews currently known hallmarks of ageing and their clinical implications. A literature search of PubMed/MEDLINE was conducted covering the last decade. Average life expectancy has increased dramatically over the past century and is estimated to increase even further. Maximum longevity, however, appears unchanged, suggesting a universal limitation to the human organism. Understanding the underlying molecular processes of ageing and health decline may suggest interventions that, if used at an early age, can prevent, delay, alleviate or even reverse age-related diseases. Hallmarks of ageing can be grouped into three main categories. The primary hallmarks cause damage to cellular functions: genomic instability, telomere attrition, epigenetic alterations and loss of proteostasis. These are followed by antagonistic responses to such damage: deregulated nutrient sensing, altered mitochondrial function and cellular senescence. Finally, integrative hallmarks are possible culprits of the clinical phenotype (stem cell exhaustion and altered intercellular communication), which ultimately contribute to the clinical effects of ageing as seen in physiological loss of reserve, organ decline and reduced function. The sum of these molecular hallmarks produces the clinical picture of the elderly surgical patient: frailty, sarcopenia, anaemia, poor nutrition and a blunted immune response system. Improved understanding of the ageing processes may give rise to new biomarkers of risk or prognosis, novel treatment targets and translational approaches across disciplines that may improve outcomes. © 2016 BJS Society Ltd Published by John Wiley & Sons Ltd.
NAD(P)H oxidase p22(phox) polymorphism and cardiovascular function in amateur runners.

PubMed

Gallina, S; Di Francescomarino, S; Di Mauro, M; Izzicupo, P; D'Angelo, E; D'Amico, M A; Pennelli, A; Amicarelli, F; Di Baldassarre, A

2012-09-01

NAD(P)H system represents the major source of superoxide production at cardiovascular (CV) level. It has several genetic variants: in particular, the C242T polymorphism of its p22(phox) subunit is associated with a different oxidase activity, being the T allele related to a lower superoxide production. Although several authors investigated the protective effect of T allele in CV diseases, only few data are available on its functional role in physiological conditions. The aim of our study was to investigate the relationship between the p22(phox) C242T polymorphism and CV function in amateur runners. Seventy-three male amateur runners were screened for CYBA polymorphism. CV analysis was performed by echocardiographic-Doppler examination and by PulsePen tonometer assessment. The genetic subgroups (CC and CT/TT) did not differ for VM O(2max) and cardiac dimension. Nevertheless, T carriers (n = 40) were characterized by a more efficient myocardial contraction and left ventricular (LV) filling, as evidenced by significant higher values of the midwall fractional shortening, systolic excursion of the tricuspid annular plane and of early/late diastolic wave velocities ratio and by a lower E wave deceleration time. Pulse wave velocity and augmentation index, parameters related to the arterial stiffness, were higher in CC subjects compared with CT/TT also when the analysis was adjusted for weight and diastolic pressure. In amateur runners, CYBA variants may influence both systolic and diastolic function and arterial stiffness. We suppose that the lower oxidative activity that characterizes 242T subjects may positively influence the excitation-contraction and arterial-ventricular coupling mechanisms, thus leading to a more efficient CV function. © 2012 The Authors Acta Physiologica © 2012 Scandinavian Physiological Society.
Flipping the Metabolic Switch: Understanding and Applying Health Benefits of Fasting

PubMed Central

Anton, Stephen D.; Moehl, Keelin; Donahoo, William T.; Marosi, Krisztina; Lee, Stephanie; Mainous, Arch G.; Leeuwenburgh, Christiaan; Mattson, Mark P.

2017-01-01

Intermittent fasting (IF) is a term used to describe a variety of eating patterns in which no or few calories are consumed for time periods that can range from 12 hours to several days, on a recurring basis. Here we focus on the physiological responses of major organ systems, including the musculoskeletal system, to the onset of the metabolic switch – the point of negative energy balance at which liver glycogen stores are depleted and fatty acids are mobilized (typically beyond 12 hours after cessation of food intake). Emerging findings suggest the metabolic switch from glucose to fatty acid-derived ketones represents an evolutionarily conserved trigger point that shifts metabolism from lipid/cholesterol synthesis and fat storage to mobilization of fat through fatty acid oxidation and fatty-acid derived ketones, which serve to preserve muscle mass and function. Thus, IF regimens that induce the metabolic switch have the potential to improve body composition in overweight individuals. Moreover, IF regimens also induce the coordinated activation of signaling pathways that optimize physiological function, enhance performance, and slow aging and disease processes. Future randomized controlled IF trials should use biomarkers of the metabolic switch (e.g., plasma ketone levels) as a measure of compliance and the magnitude of negative energy balance during the fasting period. PMID:29086496
Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting.

PubMed

Anton, Stephen D; Moehl, Keelin; Donahoo, William T; Marosi, Krisztina; Lee, Stephanie A; Mainous, Arch G; Leeuwenburgh, Christiaan; Mattson, Mark P

2018-02-01

Intermittent fasting (IF) is a term used to describe a variety of eating patterns in which no or few calories are consumed for time periods that can range from 12 hours to several days, on a recurring basis. This review is focused on the physiological responses of major organ systems, including the musculoskeletal system, to the onset of the metabolic switch: the point of negative energy balance at which liver glycogen stores are depleted and fatty acids are mobilized (typically beyond 12 hours after cessation of food intake). Emerging findings suggest that the metabolic switch from glucose to fatty acid-derived ketones represents an evolutionarily conserved trigger point that shifts metabolism from lipid/cholesterol synthesis and fat storage to mobilization of fat through fatty acid oxidation and fatty acid-derived ketones, which serve to preserve muscle mass and function. Thus, IF regimens that induce the metabolic switch have the potential to improve body composition in overweight individuals. Moreover, IF regimens also induce the coordinated activation of signaling pathways that optimize physiological function, enhance performance, and slow aging and disease processes. Future randomized controlled IF trials should use biomarkers of the metabolic switch (e.g., plasma ketone levels) as a measure of compliance and of the magnitude of negative energy balance during the fasting period. © 2017 The Obesity Society.

Investigation of cerebral venous outflow in microgravity.

PubMed

Taibi, A; Gadda, G; Gambaccini, M; Menegatti, E; Sisini, F; Zamboni, P

2017-10-31

The gravitational gradient is the major component to face when considering the physiology of venous return, and there is a growing interest in understanding the mechanisms ensuring the heart filling, in the absence of gravity, for astronauts who perform long-term space missions. The purpose of the Drain Brain project was to monitor the cerebral venous outflow of a crew member during an experiment on the International Space Station (ISS), so as to study the compensatory mechanisms that facilitate this essential physiological action in subjects living in a microgravity environment. Such venous function has been characterized by means of a novel application of strain-gauge plethysmography which uses a capacitive sensor. In this contribution, preliminary results of our investigation have been presented. In particular, comparison of plethysmography data confirmed that long duration spaceflights lead to a redistribution of venous blood volume, and showed interesting differences in the amplitude of cardiac oscillations measured at the level of the neck veins. The success of the experiment has also demonstrated that thanks to its easy portability, non-invasiveness, and non-operator dependence, the proposed device can be considered as a novel tool for use aboard the ISS. Further trials are now under way to complete the investigation on the drainage function of the neck veins in microgravity.
Stocking impacts the expression of candidate genes and physiological condition in introgressed brook charr (Salvelinus fontinalis) populations

PubMed Central

Lamaze, Fabien C; Garant, Dany; Bernatchez, Louis

2013-01-01

Translocation of plants and animal populations between environments is one of the major forms of anthropogenic perturbation experienced by pristine populations, and consequently, human-mediated hybridization by stocking practices between wild and exogenous conspecifics is of increasing concern. In this study, we compared the expression of seven candidate genes involved in multifactorial traits and regulatory pathways for growth as a function of level of introgressive hybridization between wild and domestic brook charr to test the null hypothesis of no effect of introgression on wild fish. Our analyses revealed that the expression of two of the genes tested, cytochrome c oxidase VIIa and the growth hormone receptor isoform I, was positively correlated with the level of introgression. We also observed a positive relationship between the extent of introgression and physiological status quantified by the Fulton's condition index. The expression of other genes was influenced by other variables, including year of sampling (reflecting different thermal conditions), sampling method and lake of origin. This is the first demonstration in nature that introgression from stocked populations has an impact on the expression of genes playing a role in important biological functions that may be related with fitness in wild introgressed populations. PMID:23467764
Combined effects of physiologically relevant disturbed wall shear stress and glycated albumin on endothelial cell functions associated with inflammation, thrombosis and cytoskeletal dynamics.

PubMed

Maria, Zahra; Yin, Wei; Rubenstein, David Alan

2014-07-01

Diabetes mellitus is a major risk factor in the development of cardiovascular diseases (CVDs). The presence of advanced glycation end-products (AGEs) promotes CVDs by upregulating endothelial cell (EC) inflammatory and thrombotic responses, in a similar manner as disturbed shear stress. However, the combined effect of disturbed shear stress and AGEs on EC function has yet to be determined. Our goal was to evaluate these effects on EC responses. ECs were incubated with AGEs for 5 days. ECs were then subjected to physiological or pathological shear stress. Cell metabolic activity, surface expression of intercellular adhesion molecule-1, thrombomodulin, connexin-43 and caveolin-1, and cytoskeleton organization were quantified. The results show that irreversibly glycated albumin and pathological shear stress increased EC metabolic activity, and upregulated and downregulated the EC surface expression of intercellular adhesion molecule-1 and thrombomodulin, respectively. Expression of connexin-43, caveolin-1 and cytoskeletal organization was independent of shear stress; however, the presence of irreversibly glycated AGEs markedly increased connexin-43, and decreased caveolin-1 expression and actin cytoskeletal connectivity. Our data suggest that irreversibly glycated albumin and disturbed shear stress could promote CVD pathogenesis by enhancing EC inflammatory and thrombotic responses, and through the deterioration of the cytoskeletal organization.
Regulation of tolerance of Chlamydomonas reinhardtii to heavy metal toxicity by heme oxygenase-1 and carbon monoxide.

PubMed

Wei, Yuan Yuan; Zheng, Qi; Liu, Zhao Pu; Yang, Zhi Min

2011-09-01

Investigation of heavy metal tolerance genes in green algae is of great importance because heavy metals have become one of the major contaminants in the aquatic ecosystem. In plants, accumulation of heavy metals modifies many aspects of cellular functions. However, the mechanism by which heavy metals exert detrimental effects is poorly understood. In this study, we identified a role for HO-1 (encoding heme oxygenase-1) in regulating the response of Chlamydomonas reinhardtii, a unicellular green alga, to mercury (Hg). Transgenic algae overexpressing HO-1 showed high tolerance to Hg exposure, with a 48.2% increase in cell number over the wild type, but accumulated less Hg. Physiological analysis revealed that expression of HO-1 suppressed the Hg-induced generation of reactive oxygen species. We further identified the effect of carbon monoxide (CO), a product of HO-1-mediated heme degradation, on growth and physiological parameters. Interestingly, administration of exogenous CO at non-toxic levels also conferred the tolerance of algae to Hg exposure. The CO-mediated alleviation of Hg toxicity was closely related to the lower accumulation of Hg and free radical species. These results indicate that functional identification of HO-1 is useful for molecular breeding designed to improve plant tolerance to heavy metals and reduce heavy metal accumulation in plant cells.
Coping with Stresses: Roles of Calcium- and Calcium/Calmodulin-Regulated Gene Expression[W][OA

PubMed Central

Reddy, Anireddy S.N.; Ali, Gul S.; Celesnik, Helena; Day, Irene S.

2011-01-01

Abiotic and biotic stresses are major limiting factors of crop yields and cause billions of dollars of losses annually around the world. It is hoped that understanding at the molecular level how plants respond to adverse conditions and adapt to a changing environment will help in developing plants that can better cope with stresses. Acquisition of stress tolerance requires orchestration of a multitude of biochemical and physiological changes, and most of these depend on changes in gene expression. Research during the last two decades has established that different stresses cause signal-specific changes in cellular Ca2+ level, which functions as a messenger in modulating diverse physiological processes that are important for stress adaptation. In recent years, many Ca2+ and Ca2+/calmodulin (CaM) binding transcription factors (TFs) have been identified in plants. Functional analyses of some of these TFs indicate that they play key roles in stress signaling pathways. Here, we review recent progress in this area with emphasis on the roles of Ca2+- and Ca2+/CaM-regulated transcription in stress responses. We will discuss emerging paradigms in the field, highlight the areas that need further investigation, and present some promising novel high-throughput tools to address Ca2+-regulated transcriptional networks. PMID:21642548
The Endocannabinoid System in the Retina: From Physiology to Practical and Therapeutic Applications

PubMed Central

Schwitzer, Thomas; Schwan, Raymund; Angioi-Duprez, Karine; Giersch, Anne; Laprevote, Vincent

2016-01-01

Cannabis is one of the most prevalent drugs used in industrialized countries. The main effects of Cannabis are mediated by two major exogenous cannabinoids: ∆9-tetrahydroxycannabinol and cannabidiol. They act on specific endocannabinoid receptors, especially types 1 and 2. Mammals are endowed with a functional cannabinoid system including cannabinoid receptors, ligands, and enzymes. This endocannabinoid signaling pathway is involved in both physiological and pathophysiological conditions with a main role in the biology of the central nervous system. As the retina is a part of the central nervous system due to its embryonic origin, we aim at providing the relevance of studying the endocannabinoid system in the retina. Here, we review the distribution of the cannabinoid receptors, ligands, and enzymes in the retina and focus on the role of the cannabinoid system in retinal neurobiology. This review describes the presence of the cannabinoid system in critical stages of retinal processing and its broad involvement in retinal neurotransmission, neuroplasticity, and neuroprotection. Accordingly, we support the use of synthetic cannabinoids as new neuroprotective drugs to prevent and treat retinal diseases. Finally, we argue for the relevance of functional retinal measures in cannabis users to evaluate the impact of cannabis use on human retinal processing. PMID:26881099
Transfer of the second to the first metatarsal ray in a case of lawn mower injury: a case report.

PubMed

Sassu, Paolo; Tsai, Tsu Min

2009-01-01

The medial longitudinal arch of the foot plays a major role for a physiologic transfer of the load from the heel to the forefoot during walking and running. Traumatic amputation that involve either the great toe or the whole first metatarsal bone can lead to collapse of the medial longitudinal arch, overload of the metatarsal heads, and painful callus formation. If replant of the amputated part is not possible or has failed, it is advisable to reconstruct the medial longitudinal arch in order to re-establish a functional transfer of the load in the foot. We present a case of a young lady who suffered from traumatic amputation at the distal third of the first metatarsal. Replantation failed due to the severity of the initial injury. Despite a good coverage of the defect with a lateral arm flap, the patient developed a painful plantar callus underneath the amputated stump. The adjacent second metatarsal ray was then raised as a pedicled flap including bone and soft tissues and transferred to the first ray in order to reconstruct a physiologic medial longitudinal arch. The patient had excellent functional results with no recurrence of the callus. (c) 2008 Wiley-Liss, Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, Cassandra E.; Rogowski, Artur; Morland, Carl

Degradation of polysaccharides forms an essential arc in the carbon cycle, provides a percentage of our daily caloric intake, and is a major driver in the renewable chemical industry. Microorganisms proficient at degrading insoluble polysaccharides possess large numbers of carbohydrate active enzymes, many of which have been categorized as functionally redundant. Here we present data that suggests that carbohydrate active enzymes that have overlapping enzymatic activities can have unique, non-overlapping biological functions in the cell. Our comprehensive study to understand cellodextrin utilization in the soil saprophyte Cellvibrio japonicus found that only one of four predicted β-glucosidases is required in amore » physiological context. Gene deletion analysis indicated that only the cel3B gene product is essential for efficient cellodextrin utilization in C. japonicus and is constitutively expressed at high levels. Interestingly, expression of individual β-glucosidases in Escherichia coli K-12 enabled this non-cellulolytic bacterium to be fully capable of using cellobiose as a sole carbon source. Furthermore, enzyme kinetic studies indicated that the Cel3A enzyme is significantly more active than the Cel3B enzyme on the oligosaccharides but not disaccharides. Finally, our approach for parsing related carbohydrate active enzymes to determine actual physiological roles in the cell can be applied to other polysaccharide-degradation systems.« less
Bioinformatic analysis of the neprilysin (M13) family of peptidases reveals complex evolutionary and functional relationships.

PubMed

Bland, Nicholas D; Pinney, John W; Thomas, Josie E; Turner, Anthony J; Isaac, R Elwyn

2008-01-23

The neprilysin (M13) family of endopeptidases are zinc-metalloenzymes, the majority of which are type II integral membrane proteins. The best characterised of this family is neprilysin, which has important roles in inactivating signalling peptides involved in modulating neuronal activity, blood pressure and the immune system. Other family members include the endothelin converting enzymes (ECE-1 and ECE-2), which are responsible for the final step in the synthesis of potent vasoconstrictor endothelins. The ECEs, as well as neprilysin, are considered valuable therapeutic targets for treating cardiovascular disease. Other members of the M13 family have not been functionally characterised, but are also likely to have biological roles regulating peptide signalling. The recent sequencing of animal genomes has greatly increased the number of M13 family members in protein databases, information which can be used to reveal evolutionary relationships and to gain insight into conserved biological roles. The phylogenetic analysis successfully resolved vertebrate M13 peptidases into seven classes, one of which appears to be specific to mammals, and insect genes into five functional classes and a series of expansions, which may include inactive peptidases. Nematode genes primarily resolved into groups containing no other taxa, bar the two nematode genes associated with Drosophila DmeNEP1 and DmeNEP4. This analysis reconstructed only one relationship between chordate and invertebrate clusters, that of the ECE sub-group and the DmeNEP3 related genes. Analysis of amino acid utilisation in the active site of M13 peptidases reveals a basis for their biochemical properties. A relatively invariant S1' subsite gives the majority of M13 peptidases their strong preference for hydrophobic residues in P1' position. The greater variation in the S2' subsite may be instrumental in determining the specificity of M13 peptidases for their substrates and thus allows M13 peptidases to fulfil a broad range of physiological roles. The M13 family of peptidases have diversified extensively in all species examined, indicating wide ranging roles in numerous physiological processes. It is predicted that differences in the S2' subsite are fundamental to determining the substrate specificities that facilitate this functional diversity.
Pluripotent Stem Cells for Retinal Tissue Engineering: Current Status and Future Prospects.

PubMed

Singh, Ratnesh; Cuzzani, Oscar; Binette, François; Sternberg, Hal; West, Michael D; Nasonkin, Igor O

2018-04-19

The retina is a very fine and layered neural tissue, which vitally depends on the preservation of cells, structure, connectivity and vasculature to maintain vision. There is an urgent need to find technical and biological solutions to major challenges associated with functional replacement of retinal cells. The major unmet challenges include generating sufficient numbers of specific cell types, achieving functional integration of transplanted cells, especially photoreceptors, and surgical delivery of retinal cells or tissue without triggering immune responses, inflammation and/or remodeling. The advances of regenerative medicine enabled generation of three-dimensional tissues (organoids), partially recreating the anatomical structure, biological complexity and physiology of several tissues, which are important targets for stem cell replacement therapies. Derivation of retinal tissue in a dish creates new opportunities for cell replacement therapies of blindness and addresses the need to preserve retinal architecture to restore vision. Retinal cell therapies aimed at preserving and improving vision have achieved many improvements in the past ten years. Retinal organoid technologies provide a number of solutions to technical and biological challenges associated with functional replacement of retinal cells to achieve long-term vision restoration. Our review summarizes the progress in cell therapies of retina, with focus on human pluripotent stem cell-derived retinal tissue, and critically evaluates the potential of retinal organoid approaches to solve a major unmet clinical need-retinal repair and vision restoration in conditions caused by retinal degeneration and traumatic ocular injuries. We also analyze obstacles in commercialization of retinal organoid technology for clinical application.
Biomineralization changes with food supply confer juvenile scallops (Argopecten purpuratus) resistance to ocean acidification.

PubMed

Ramajo, Laura; Marbà, Núria; Prado, Luis; Peron, Sophie; Lardies, Marco A; Rodriguez-Navarro, Alejandro B; Vargas, Cristian A; Lagos, Nelson A; Duarte, Carlos M

2016-06-01

Future ocean acidification (OA) will affect physiological traits of marine species, with calcifying species being particularly vulnerable. As OA entails high energy demands, particularly during the rapid juvenile growth phase, food supply may play a key role in the response of marine organisms to OA. We experimentally evaluated the role of food supply in modulating physiological responses and biomineralization processes in juveniles of the Chilean scallop, Argopecten purpuratus, that were exposed to control (pH ~ 8.0) and low pH (pH ~ 7.6) conditions using three food supply treatments (high, intermediate, and low). We found that pH and food levels had additive effects on the physiological response of the juvenile scallops. Metabolic rates, shell growth, net calcification, and ingestion rates increased significantly at low pH conditions, independent of food. These physiological responses increased significantly in organisms exposed to intermediate and high levels of food supply. Hence, food supply seems to play a major role modulating organismal response by providing the energetic means to bolster the physiological response of OA stress. On the contrary, the relative expression of chitin synthase, a functional molecule for biomineralization, increased significantly in scallops exposed to low food supply and low pH, which resulted in a thicker periostracum enriched with chitin polysaccharides. Under reduced food and low pH conditions, the adaptive organismal response was to trade-off growth for the expression of biomineralization molecules and altering of the organic composition of shell periostracum, suggesting that the future performance of these calcifiers will depend on the trajectories of both OA and food supply. Thus, incorporating a suite of traits and multiple stressors in future studies of the adaptive organismal response may provide key insights on OA impacts on marine calcifiers. © 2015 John Wiley & Sons Ltd.
Development of a rate model to investigate contributions of anatomic and physiologic determinants of in vivo skin permeation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleischer, N.M.

The skin is a heterogeneous, bi-directional impediment to chemical flux, in which the stratum corneum is a major, though not the sole, rate-limiting barrier layer to permeation. Systemic toxicity following dermal exposure to environmental chemicals and use of skin as a portal for systemic administration of drugs have led to extensive investigations of the inward flux of xenobiotics applied to the outer surface of skin. Those investigations mainly utilized in vitro experimental systems that were limited by the absence of normal physiologic functions. The objective of the present research was to investigate an in vivo skin permeation model system thatmore » was sensitive to perturbations of skin capillary physiology and stratum corneum. A [open quotes]fuzzy[close quotes] rat model system was devised that employed outward cutaneous migration of a systemically administered permeation probe, isoflurane. Specially devised, transdermal vapor collection devices were used to capture the outward flux of isoflurane through the skin. Isoflurane flux measurements, coupled with blood isoflurane concentrations, were used to calculate cutaneous permeability coefficients (K[sub p]) of isolflurane, as an index of permeation, under various conditions of normal or perturbed cutaneous physiologic states. Physiologic perturbations were performed to test the sensitivity of the model system to detect effects of minoxidil-mediated vasodilation, phenylephrine-mediated vasoconstriction, and leukotriene D[sub 4]-mediated increased capillary permeability on the outward flux of isoflurane. Tape stripping and topical ether-ethanol application produced either physical removal or chemical disruption of the stratum corneum, respectively. Minoxidil, leukotriene D[sub 4], tape stripping of stratum corneum, and topical ether-ethanol experiments produced statistically significant increases (52 to 193%) in the K[sub p's], while phenylephrine had no significant effect on isoflurane permeation.« less
ARG1 Functions in the Physiological Adaptation of Undifferentiated Plant Cells to Spaceflight

NASA Astrophysics Data System (ADS)

Zupanska, Agata K.; Schultz, Eric R.; Yao, JiQiang; Sng, Natasha J.; Zhou, Mingqi; Callaham, Jordan B.; Ferl, Robert J.; Paul, Anna-Lisa

2017-11-01

Scientific access to spaceflight and especially the International Space Station has revealed that physiological adaptation to spaceflight is accompanied or enabled by changes in gene expression that significantly alter the transcriptome of cells in spaceflight. A wide range of experiments have shown that plant physiological adaptation to spaceflight involves gene expression changes that alter cell wall and other metabolisms. However, while transcriptome profiling aptly illuminates changes in gene expression that accompany spaceflight adaptation, mutation analysis is required to illuminate key elements required for that adaptation. Here we report how transcriptome profiling was used to gain insight into the spaceflight adaptation role of Altered response to gravity 1 (Arg1), a gene known to affect gravity responses in plants on Earth. The study compared expression profiles of cultured lines of Arabidopsis thaliana derived from wild-type (WT) cultivar Col-0 to profiles from a knock-out line deficient in the gene encoding ARG1 (ARG1 KO), both on the ground and in space. The cell lines were launched on SpaceX CRS-2 as part of the Cellular Expression Logic (CEL) experiment of the BRIC-17 spaceflight mission. The cultured cell lines were grown within 60 mm Petri plates in Petri Dish Fixation Units (PDFUs) that were housed within the Biological Research In Canisters (BRIC) hardware. Spaceflight samples were fixed on orbit. Differentially expressed genes were identified between the two environments (spaceflight and comparable ground controls) and the two genotypes (WT and ARG1 KO). Each genotype engaged unique genes during physiological adaptation to the spaceflight environment, with little overlap. Most of the genes altered in expression in spaceflight in WT cells were found to be Arg1-dependent, suggesting a major role for that gene in the physiological adaptation of undifferentiated cells to spaceflight.
Mitochondrial activity and dynamics changes regarding metabolism in ageing and obesity.

PubMed

López-Lluch, Guillermo

2017-03-01

Mitochondria play an essential role in ageing and longevity. During ageing, a general deregulation of metabolism occurs, affecting molecular, cellular and physiological activities in the organism. Dysfunction of mitochondria has been associated with ageing and age-related diseases indicating their importance in the maintenance of cell homeostasis. Three major nutritional sensors, mTOR, AMPK and Sirtuins are involved in the control of mitochondrial physiology. These nutritional sensors control mitochondrial biogenesis, dynamics by regulating fusion and fission processes, and turnover through mito- and autophagy. Apart of the known factors involved in fusion, OPA1 and mitofusins, and fission, DRP1 and FIS1, emerging factors such as prohibitins and sestrins can play important functions in mitochondrial dynamics regulation. Mitochondria is also affected by sexual hormones that suffer drastic changes during ageing. The recent literature demonstrates the complex interaction between nutritional sensors and mitochondrial homeostasis in the physiology of adipose tissue and in the accumulation of fat in other organs such as muscle and liver. In this article, the role of mitochondrial homeostasis in ageing and age-dependent fat accumulation is revised. This review highlights the importance of mitochondria in the accumulation of fat during ageing and related diseases such as obesity, metabolic syndrome or type 2 diabetes mellitus. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Feeding behavior, obesity, and neuroeconomics⋆

PubMed Central

Rowland, Neil E.; Vaughan, Cheryl H.; Mathes, Clare M.; Mitra, Anaya

2008-01-01

For the past 50 years, the most prevalent theoretical models for regulation of food intake have been based in the physiological concept of energy homeostasis. However, several authors have noted that the simplest form of homeostasis, stability, does not accurately reflect the actual state of affairs and most notably the recent upward trend in body mass index observed in the majority of affluent nations. The present review argues that processes of natural selection have more likely made us first and foremost behavioral opportunists that are adapted to uncertain environments, and that physiological homeostasis is subservient to that reality. Examples are presented from a variety of laboratory studies indicating that food intake is a function of the effort and/or time required to procure that food, and that economic decision making is central to understanding how much and when organisms eat. The discipline of behavioral economics has developed concepts that are useful for this enterprise, and some of these are presented. Lastly, we present demonstrations in which genetic or physiologic investigations using environmental complexity will lead to more realistic ideas about how to understand and treat idiopathic human obesity. The fact is that humans are eating more and gaining weight in favorable food environments in exactly the way predicted from some of these models, and this has implications for the appropriate way to treat obesity. PMID:17825853
Parent Cortisol and Family Relatedness Predict Anxious Behavior in Emerging Adults

PubMed Central

Johnson, Vanessa Kahen; Gans, Susan E.

2016-01-01

Emerging adult cortisol response during family interaction predicts change in EA anxious behavior during the transition to college (Gans & Johnson, in press). In the present study, we take an additional step toward integrating family systems research and physiology by including assessment of parent physiology. We collect salivary cortisol from parents and emerging-adults during triadic family interaction. Emerging adults (N = 101) between the ages of 17 and 19 were assessed at three time points across their first college year: the summer before college, fall and spring semesters. Two parents accompanied the emerging adult child to the summer assessment; all family members provided four saliva samples each at 20-minute intervals. Later assessments of emerging adults included measures of internalizing behaviors. Parents’ cortisol secretion patterns during family interaction predict their emerging adult child’s cortisol secretion pattern, parent perceptions of the family environment, and emerging adult children’s internalizing behavior during the college transition. Different patterns of results emerged for mothers’ and fathers’ cortisol response to family interaction, and for families with sons or with daughters. The approach taken by this study provides a first step toward understanding how interrelationships among elements of physiology and family functioning contribute to adjustment during major life transitions. PMID:27536860
The emerging physiological roles of the SLC14A family of urea transporters

PubMed Central

Stewart, Gavin

2011-01-01

In mammals, urea is the main nitrogenous breakdown product of protein catabolism and is produced in the liver. In certain tissues, the movement of urea across cell membranes is specifically mediated by a group of proteins known as the SLC14A family of facilitative urea transporters. These proteins are derived from two distinct genes, UT-A (SLC14A2) and UT-B (SLC14A1). Facilitative urea transporters play an important role in two major physiological processes – urinary concentration and urea nitrogen salvaging. Although UT-A and UT-B transporters both have a similar basic structure and mediate the transport of urea in a facilitative manner, there are a number of significant differences between them. UT-A transporters are mainly found in the kidney, are highly specific for urea, have relatively lower transport rates and are highly regulated at both gene expression and cellular localization levels. In contrast, UT-B transporters are more widespread in their tissue location, transport both urea and water, have a relatively high transport rate, are inhibited by mercurial compounds and currently appear to be less acutely regulated. This review details the fundamental research that has so far been performed to investigate the function and physiological significance of these two types of urea transporters. PMID:21449978
Parent cortisol and family relatedness predict anxious behavior in emerging adults.

PubMed

Johnson, Vanessa Kahen; Gans, Susan E

2016-10-01

Emerging-adult cortisol response during family interaction predicts change in emerging-adult anxious behavior during the transition to college (Gans & Johnson, in press). In the present study, we take an additional step toward integrating family systems research and physiology by including assessment of parent physiology. We collect salivary cortisol from parents and emerging adults during triadic family interaction. Emerging adults (N = 101) between the ages of 17 and 19 years were assessed at 3 time points across their first college year: the summer before college and the Fall and Spring semesters. Two parents accompanied the emerging-adult child to the summer assessment; all family members provided 4 saliva samples each at 20-min intervals. Later assessments of emerging adults included measures of internalizing behaviors. Parents' cortisol secretion patterns during family interaction predict their emerging-adult children's cortisol secretion pattern, parent perceptions of the family environment, and emerging-adult children's internalizing behavior during the college transition. Different patterns of results emerged for mothers' and fathers' cortisol response to family interaction and for families with sons or with daughters. The approach taken by this study provides a first step toward understanding how interrelationships among elements of physiology and family functioning contribute to adjustment during major life transitions. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
A new look at cerebrospinal fluid circulation

PubMed Central

2014-01-01

According to the traditional understanding of cerebrospinal fluid (CSF) physiology, the majority of CSF is produced by the choroid plexus, circulates through the ventricles, the cisterns, and the subarachnoid space to be absorbed into the blood by the arachnoid villi. This review surveys key developments leading to the traditional concept. Challenging this concept are novel insights utilizing molecular and cellular biology as well as neuroimaging, which indicate that CSF physiology may be much more complex than previously believed. The CSF circulation comprises not only a directed flow of CSF, but in addition a pulsatile to and fro movement throughout the entire brain with local fluid exchange between blood, interstitial fluid, and CSF. Astrocytes, aquaporins, and other membrane transporters are key elements in brain water and CSF homeostasis. A continuous bidirectional fluid exchange at the blood brain barrier produces flow rates, which exceed the choroidal CSF production rate by far. The CSF circulation around blood vessels penetrating from the subarachnoid space into the Virchow Robin spaces provides both a drainage pathway for the clearance of waste molecules from the brain and a site for the interaction of the systemic immune system with that of the brain. Important physiological functions, for example the regeneration of the brain during sleep, may depend on CSF circulation. PMID:24817998
Exercise, physiological function, and the selection of participants for aging research.

PubMed

Lazarus, Norman R; Harridge, Stephen D R

2010-08-01

Regular and vigorous exercisers appear to be the logical choice for studying the inherent aging process as they are essentially free from the complications of disuse. Cross-sectional studies of aging tend to depict an essentially smooth and progressive decrement of physiological function with increasing chronological age. On closer examination of such data, it is seen that although the young have high functional values and the very old low, between these limits, values are widely scattered. We have reevaluated published data from a meta-analysis of 242 studies on men and from a similar study on women. From both data sets, where VO2max was plotted against chronological age, we stratified the VO2max values into bandwidth intervals of 5 ml/kg/minute and then allocated data points to their respective bandwidth irrespective of chronological age. When replotted into bandwidths of functional equivalence, these data show that at the extremes of function, the young are separated from the old. Between these values, each functional bandwidth accommodates a wide age range. The decrement in function with chronological age is not smooth or well defined. We suggest that participants for research into healthy aging should be initially segregated into bands of functionally equivalent VO2max values irrespective of their chronological age. Subsequently, other physiological measurements should be made on every participant in the band in order to begin to define the physiological profile of the participants. By conducting longitudinal studies on every individual, it will be possible to chart the physiological history of each participant through various ages. Segregating participants into cohorts of functional equivalence with data handling blinded to chronological age may be of great utility in increasing our understanding of the inherent aging process.

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Sample records for major physiological functions

Abstract