bluuebunny/crossref_metadata_2025 huggingface dataset:
Neural Transplantation in Animal Models of Neurodegenerative Disesase
Authors: Collier TJ , Sladek John R,
Published: December 2017

Interest in neural transplantation research has increased greatly in the past five years. Although this procedure initially was viewed as a research tool for studying neuronal development, it is gaining attention as a potential therapeutic intervention. Indeed, replacement of chemically defined neurons in animal models of the neurodegeneration that occurs in Parkinson's disease and Alzheimer's disease indicates that grafted fetal neurons survive transplantation, integrate with the host brain, and produce a sustained improvement of motor function and memory performance.
Voltage Sensors and Calcium Channels of Excitation-Contraction Coupling
Authors: Rios E , Pizarro G
Published: December 2017

Three mechanisms are proposed for the transduction from action potential to Ca2+ release from the sarcoplasmic reticulum in skeletal muscle: Chemical mediation, a mechanical connection between transverse tubular membrane and sacroplasmic reticulum, and Ca2+-induced release of Ca2+. New biochemical, biophysical, and structural data favor a mechanical connection and add the possibility that Ca2+-induced Ca2+-release is working in parallel.
Physiological Uses of Nuclear Magnetic Resonance
Authors: Avison MJ , Siegel NJ
Published: December 2017

Nuclear magnetic resonance provides physiologists with a flexible means of measuring a wide range of cell and tissue parameters. These measurements can be nondestructive and noninvasive. Recent technical developments have enabled several of these approaches to be applied to human studies.
Salt and Water Metabolism in Acute High-Altitude Hypoxia: Role of Peripheral Arterial Chemoreceptors
Authors: Honig Arnold
Published: December 2017

Mammals acutely exposed to hypobaric hypoxia establish a lower plasma volume by increasing urine excretion or by reducing salt and water intake. These responses are of adaptive value, for by concentrating available hemoglobin they increase OS-binding capacity of the blood. The reactions of sodium metabolism in arterial hypoxia are controlled by peripheral arterial chemoreceptors.
Energetics at the Single Cell Level
Authors: van der Laarse WJ , Elzinga G , Woledge RC
Published: December 2017

Recently developed techniques allow the study of energy flow at the cellular level and show in new detail how cells are individually adapted for their particular energetic roles.
Calcium Signalling System Triggered by INsulin-Like Growth Factor II
Authors: Nishimoto I , Kojima I
Published: December 2017

In BALB/c 3T3 fibroblast, the insulin-like growth factor (IGF-II) stimulates DNA replication when added to cells pretreated sequentially with platelet-derived and epidermal growth factors. In these cells, IGF-II increases calcium influx by opening a voltage-independent calcium-permeable channel, and calcium influx is an intracellular message of the IGF-II action.
New Insights Regarding Organization of Spinal Cord Pain Pathways
Authors: Hammond DL
Published: December 2017

The recently identified existence of a dorsolateral spinothalamic tract of unknown function calls for revision of a classic tenet of pain transmission. Moreover, the newly described direct projection of nociceptive dorsal horn neurons to areas involved in autonomic, visceral, and limbic function, as well as to the thalamus, challenges the belief that ascending pain pathways merely mediate the sensory-discriminative component of pain.
Endothelial Control of Vascular Function
Authors: Daniel TO , Ives HE
Published: December 2017

Endothelial cells are exposed to stimuli within the lumen of blood vessels. Interpreting these signals, endothelial cells regulate production and release of mediators that signal underlying smooth muscle to contract, relax, or proliferate. Specialization of endothelial cells in different vascular beds may determine regional responses.
Tumoral Parathyroid Hormone-Related Protein: A New Hormone Affecting Calcium and Phosphate Transport
Authors: Rizzoli R , Pizurki L , Bonjour J-P
Published: December 2017

Synthetic NH2-terminal fragments of a tumoral product with an NH2- terminal homology with parathyroid hormone reproduce many of the known effects of parathyroid hormone on the fluxes of calcium and phosphate at the level of bone and kidney.
Membrane Phosphoinositide Metabolism in Hypertension
Authors: Marche P
Published: December 2017

In primary hypertension an enhanced phospholipase C responsiveness appears to be one of the primary events involved in the impaired cell calcium homeostasis that finally results in increased periphreal resistance and tension.
Phosphate Handling by the Kidney During Development: Immaturity or Unique Adaptations for Growth?
Authors: Haramati A
Published: December 2017

Renal retention of phosphate during development is not simply an expression of limited excretory capacity due to functional immaturity but rather is the direct result of unique adaptations that enhance the tubular reabsorption of phosphate in the neonate to meet its demand for phosphate during growth.
Volume-Regulatory Ion Channels in Epithelial Cells
Authors: Okada Y , Hazama A
Published: December 2017

Patch-clamp studies showed that the regulatory volume decrease process is closely associated with functions of K+, Cl-, and Ca2+-permeable channels in epithelial cells. Na+-permeable channels in the regulatory volume increase process may also be involved, as deduced from whole cell recordings using intestinal epithelial cells.
Airway Mucus Secretion
Authors: Widdicombe JG , Webber SE
Published: December 2017

Mucus secretion into the airways is mainly under vagal cholinergic control, and its volume and composition are modulated by sympathetic (adrenergic) and peptidergic mechanisms. Inflammatory mediators also change the secretion. The various compositions of mucus have been little explored, and the importance of its changes in disease is little understood.
Angiogenesis InVitro: Morphogenetic and Invasive Properties of Endothelial Cells
Authors: Montesano R , Pepper M , Orci L
Published: December 2017

Angiogenesis, the formation of new capillary blood vessels, plays a crucial role in a variety of physiological and pathological processes but until recently could only be studied in animal models. Newly developed in vitro models of angiogenesis provide an opportunity for experimental dissection of molecular mechanisms of neovascularization.
Lymph Transport Mechanisms in Peripheral Lymphatics
Authors: Roddie IC
Published: December 2017

Recent work suggests many lymphatics propel lymph by intrinsic beating, the rate and force of which are automatically adjusted by the prevailing level of filling pressure (preload) and outflow resistance (afterload). Extrinsic forces on the other hand have little effect on lymph transport at normal intralymphatic pressures and volumes.
Patch-Clamp Recording of Ion Channels: Interfering Effects of Patch Pipette Glass
Authors: Zuazaga C , Steinacker A
Published: December 2017

Glass for pipettes used to record ion channel activity with the patch-clamp technique is selected on the basis of its electrical, thermal, and sealing properties. Recent findings stress a new characteristic to consider: the effect of pipette glass itself on ion channel properties.
Stop-Flow Technique: A Brief Episode in the History of Renal Physiology
Authors: Malvin Richard L. , Sullivan Lawrence P.
Published: December 2017

Stop-flow technique was developed in the late 1950s to enable localization of renal tubular transport systems. It provided useful data for some time. However, the explosion of technology that ushered in the renaissance of the micropuncture technique permitted it only a relatively brief moment on the stage of science.
Control of Insulin Secretion in Pancreatic Beta-Cells
Authors: Petersen OH
Published: December 2017

Recent studies on single cells employing both fluorometric and electrophysiological techniques reveal new aspects of metabolic regulation of cellular Ca2+ handling. Glucose-evoked increase in metabolism precedes Ca2+ influx through voltage-gated Ca2+ channels, and metabolism controls Ca2+ channel opening, not only via membrane potential changes but also more directly.
Control of Prostaglandin Production in Human Amnion
Authors: Olson DM , Zakar T , Potestio FA , Smieja Z
Published: December 2017

Prostaglandin (PG) synthesis is a vital part of parturition initiation and maintenance in humans. A principal source of PGE2 is the fetal membrane, amnion. Evidence is presented that amnion PGE2 synthesis is independently regulated at two levels: arachidonic acid mobilization and metabolism.
Properties of Sphincteric Striated Muscle
Authors: Krier J , Adams T
Published: December 2017

External anal and urethral sphincters have several common features. Each has striated muscle fibers encircling those of smooth muscle that reflexly contract to guard an orifice or relax to allow evacuation. These functions require special contractile and morphological properties and reflex control not demanded of striated skeletal muscles.
The Venous Vessels Within Skeletal Muscle
Authors: Marshall JM
Published: December 2017

Venules and veins within skeletal muscle are a site of postcapillary resistance that can be actively changed by circulating catecholamines and local vasodilator metabolites and may vary inversely with blood flow, via an effect on blood viscosity. Together these factors modulate capillary hydrostatic pressure and thereby capillary filtration.
Calcium Signals in Nerve Cells
Authors: Kostyuk PG , Tepikin AV
Published: December 2017

Increases in intracellular Ca ions follow each cycle of nerve cell activity. Sources of Ca are voltage- and receptor-operated membrane ion channels and endoplasmic reticulum (ER). Ca release from ER can be triggered by different second messengers, and uptake into the ER can terminate the Ca signal.
Interactions Between Neural and Endothelial Mechanisms in Control of Vascular Tone
Authors: Miller VM
Published: December 2017

Tone of the vascular smooth muscle is modulated by factors released from adrenergic nerve endings and the endothelium. These factors have the potential to modulate their release from each of the controlling systems.
Communication Between Minibrain in Gut and Enteric Immune System
Authors: Wood JD
Published: December 2017

An independent minibrain with as many neurons as the spinal cord and an immune system with a number of immune cells equal to those in the remainder of the body are found in the gut. This presents an ideal model for direct investigation of neuroimmune communication.
"Seeing" With Nonvisual Senses: Mechano- and Electrosensory Systems of Fish
Authors: Montgomery JC
Published: December 2017

In low-light environments the lateral line and electrosensory systems of fishes can replace vision as the major sensory modality. These systems provide insight into sensory processing for orientation, object detection, and noise suppression.
Do Splanchnic Potassium Receptors Initiate a Kaliuretic Reflex?
Authors: Rabinowitz L
Published: December 2017

In sheep, acute oral intake of K causes a rapid and precisely regulated increase in urinary K excretion that is mediated by unidentified factors other than aldosterone, systemic plasma K, diuresis, or natriuresis. K receptors in gut, hepatic portal vein, or liver may initiate a reflex increase in K secretion.
The Unanswered Question
Authors: Gorman Mark W. , Sparks Harvey V.
Published: December 2017

Is a neurotransmitter responsible for exercise hyperemia? The authors, having reviewed 100 years of research that assumes that the mediator of exercise hyperemia is released in proportion to muscle metabolism or to the oxygen supply-to-demand ratio, believe that instead an undiscovered mediator may be the basic mechanism in exercise hyperemia.
Paracrine Modulation of Baroreceptor Activity by Vascular Endothelium
Authors: Chapleau MW , Hajduczok G , Abboud FM
Published: December 2017

Arterial baroreceptors are stimulated by vascular stretch and serve to buffer fluctuations in arterial blood pressure. Factors released from endothelial cells act in a paracrine manner to modulate sensitivity of baroreceptors. Impaired endothelial cell function contributes to resetting and decreased sensitivity of baroreceptors in pathological states such as hypertension.
Neural Control of the Inspiratory Pump
Authors: Sieck GC
Published: December 2017

Motor units, essential elements in neural control of the diaphragm, vary considerably in their contractile and fatigue properties. A model is presented that assumes an orderly motor unit recruitment according to fatigue resistance. It is concluded that diaphragm motor unit composition relates to functional requirements.
The Coronary Circulation: Limitations of Current Concepts of Metabolic Control
Authors: Gewirtz H
Published: December 2017

Experimental data indicate the metabolic theory of flow regulation has difficulties explaining long-term adjustments of coronary circulation to chronic hypofusion. Evidence is reviewed supporting the hypothesis that chronic adjustments could involve changes in structural or regulatory proteins participating in vascular smooth muscle contraction.
Molecular Insights into Regulation of L-Type Ca Channel Function
Authors: Lory P , Varadi G , Schwartz A
Published: December 2017

The diversity of voltage-dependent Ca channels is well documented. How excitable cells produce their specific Ca channel activity is being approached by structure-function studies. The implications of multiple gene products, splice variants, and subunit assembly in Ca channel function are updated in this review.
Surface Forces Displace Particles Deposited in Airways Toward The Epithelium
Authors: Gehr P , Schurch S
Published: December 2017

The mucous layer of the bronchi is covered by a surfactant film. Inhaled particles, when deposited on the mucus, are displaced by surface forces into the mucus and subsequently are moved toward the epithelium where they are retained. These surface forces are the dominating factor in particle displacement.
The Insect Goblet Cell: A Problem in Functional Cytoarchitecture
Authors: Moffett DF , Koch A
Published: December 2017

The midgut of some insects actively transports K+ from blood to lumen. The transporting cells extrude K+ into an apical goblet cavity, from which it diffuses into the gut lumen via a small valve. The reasons why such a complicated cytoarchitecture envelops an ion transport process are explored.
Impaired Transmission of Pressure to the Renal Interstitium in Spontaneous Hypertension
Authors: Khraibi AA
Published: December 2017

In Okamoto spontaneously hypertensive rats, compared with control Wistar-Kyoto rats, natriuretic and diuretic responses to increases in renal perfusion pressure are attenuated but with acute saline volume expansion they are exaggerated. The extent of elevations in renal interstitial hydrostatic pressure appears to determine the natriuretic and diuretic responses.
Multiple Signaling Pathways for Platelet-Activating Factor Receptor
Authors: Shukla SD
Published: December 2017

Platelet-activating factor (PAF) receptor is coupled to multiple signaling pathways, including phospholipid turnover via phospholipases C, D, A2;Ca2+ mobilization;and activation of protein kinase C and tyrosine kinase. The cloned receptor shows homology to G protein-coupled receptors. These developments highlight receptor functions of this novel phospholipid agonist.
A Dietary Key to Uncovering Aging Processes
Authors: Masoro EJ
Published: December 2017

Reducing energy intake of laboratory rodents extends life span by retarding aging processes. This manipulation provides gerontologists with a powerful tool for studying the nature of aging processes. It also yields a data base of potential use for the development of interventions in human aging.
Protein Kinases, Phosphatases, and the Control of Cell Volume
Authors: Grinstein S , Furuya W , Bianchini L
Published: December 2017

Animal cells regulate their size in isotonic and anisotonic conditions by activating volume-sensitive solute transport systems. Recent evidence suggests that protein phosporylation/dephosphorylation is involved in volume control. These observations are integrated into a model consisting of a single volume-sensing device, a transducing element which may be a protein kinase, and two types of volume change effectors.
Dual Regulation of Phospolipase C Activity by G Proteins
Authors: Deckmyn H , Van Geet C , Vermylen J
Published: December 2017

Some subtypes of phosphatidylinositide-specific phospholipase C (PLC) are activated via pertussis toxin-sensitive or -insensitive G proteins. However, a G protein-dependent PLC inhibitory pathway also may exist. The resultant picture is of dual regulation of PLC, showing a close parallelism with the dual regulation of adenylate cyclase.
Baroreflex Abnormalities in Congestive Heart Failure
Authors: Zucker IH , Wang W , Brandle M
Published: December 2017

Abnormalities in reflex control of the circulation in heart failure are mediated by afferent and target organ alterations. Depression of afferent function is especially prominent in arterial baroreceptors. This depression is mediated by an augmentation of responses that are dependent on the action of Na+-K+-ATPase.
The Molecular Diversity of Mammalian Muscle Fibers
Authors: Pette D , Staron RS
Published: December 2017

Although muscle fibers can be separated into major groups, a spectrum of fiber types exists due to the expression of multiple protein isoforms. Also, muscle fibers are dynamic structures with the ability to change isoform expression in response to altered functional demands, changes in neural input, or hormonal signals.
Atrial Natriuretic Factor in Experimental and Human Hypertension
Authors: Garcia R
Published: December 2017

Because of its powerful natriuretic and vasorelaxant activities, as well as its effect on several systems involved in blood pressure homeostasis, the role of atrial natriuretic factor as a causal or regulatory peptide in hypertension has been investigated extensively, but still remains to be elucidated.
Fluid Pump Mechanisms in Initial Lymphatics
Authors: Schmid-Schonbein GW , Zweifach BW
Published: December 2017

Initial lymphatics are noncontractile and drain into collecting lymphatics with a smooth muscle intima, valves, and peristalsis, How does interstitial fluid enter the initial lymphatics?
Rapid Adaptation of Intestinal Sugar Transport
Authors: Debnam ES
Published: December 2017

Upregulation, within minutes, of intestinal sugar transport following changes in luminal and blood levels of glucose suggests that this phenomenon has an important homeostatic role. Rapid adaptation can involve both brush-border and basolateral membranes. Recent work suggests a complex interaction between local systemic factors in the acute enterocyte response.
Role of Nitric Oxide in Glomerular Arterioles and Macula Densa
Authors: Ito S
Published: December 2017

Nitric oxide, an endothelium-derived relaxing factor, plays an important role in glomerular hemodynamics. Recent studies provide evidence that, within the kidney, nitric oxide may be produced by not only the vascular endothelium but also macula densa and interacts with various vasoactive substances at the glomerular arterioles.
A Signaling Pathway Involving Cyclic ADP-Ribose, cGMP, and Nitric Oxide
Authors: Lee HC
Published: December 2017

Cyclic nucleotides are second messengers effecting changes mainly through protein phosphorylation. Cyclic ADP-ribose (cADPR), a newly discovered member, instead exerts its function through calcium mobilization. Increasing evidence suggests that cADPR may mediate the effects of nitric oxide on calcium, with guanosine 3', 5'-cyclic monophosphate serving as an intermediate.
Genetics of Hypertension: A Current Appraisal
Authors: Dominiczak AF , Lindpaintner K
Published: December 2017

Recent advances in molecular genetics have made it possible to approach the study of complex polygenic multifactorial diseases such as hypertension. Two major approaches, the candidate gene and genetic mapping, have been used to investigate models of genetic hypertension in the rat.
The Mammalian Facilitative Glucose Transporter Family
Authors: James DE
Published: December 2017

Over the past few years, cloning studies have revealed a large gene family of facilitative glucose transporters in mammals. The definition of the unique characteristics of each member of this family has increased dramatically our understanding of the role of individual organs in regulation of whole body glucose homeostasis.
Role of the Lymph Pump and Its Control
Authors: McHale NG
Published: December 2017

Lymphatic vessels constitute a network of series and parallel pumps, the flow of which is modulated by autoregulation and by hormones and nerves. The latter extrinsic regulators can alter the sensitivity of autoregulation such that interstitial volume may be controlled at levels higher or lower than normal.
Molecular Mechanisms of Mural Thrombosis Under Dynamic Flow Conditions
Authors: Ross JM , McIntire LV
Published: December 2017

Mural adhesion and aggregation of blood platelets are crucial for hemostasis but in pathological situations can lead to myocardial infarction and stroke. The specific platelet surface receptors employed are determined by the local fluid dynamic conditions and extracellular matrix components exposed at the site of a vascular wound.
Bugs and Barriers: Enteric Pathogens Exploit Yet Another Epithelial Function
Authors: Hecht G
Published: December 2017

Recently, there has been an explosion of information concerning bacterial-epithelial cell interactions. These studies have revealed various mechanisms by which bacterial pathogens exploit host cell machinery to their own advantage and have demonstrated that pathogenic organisms can interfere with the pathways that regulate barrier function, one of the basic properties of epithelia.
Steps to the Na+-K+ Pump and Na+-K+-ATPase (1939–1962)
Authors: Robinson Joseph D.
Published: December 2017

Beginning in 1939, new studies on muscle and red blood cells refuted current explanations of how cations distribute between cell and surroundings, explanations based on absolute impermeabilities. Subsequent revisions invoking cation pumps evolved into proposals for a coupled Na+ -K+ pump driving ouabain-sensitive fluxes; these were realized in the discovery and characterization of the Na+ -K+ -ATPase.
Sensations From J Receptors
Authors: Paintal AS
Published: December 2017

receptors produce tachypnea and the J reflex. It has now been established that they also produce certain sensations in the throat and upper chest, the intensification of which produces dry cough. These receptors also produce the sensation of breathlessness after exercise.
The Invertebrate Electrogenic 2Na+/1H+ Exchanger: Polyfunctional Epithelial Workstation
Authors: Ahearn GA
Published: December 2017

Invertebrate epithelial cells from gut, kidney, and gills possess an electrogenic brush-border 2Na+/1H+ antiporter protein that is analogous to the vertebrate electroneutral 1Na+/1H+ exchanger but that performs an extensive array of transport functions because of its electrogenic nature and wide substrate range involving both monovalent and divalent cations.
Molecular Basis for Functional Differences of AMPA-Subtype Glutamate Receptors
Authors: Ozawa S , Rossier J
Published: December 2017

To trace the molecular basis of functional properties of native a-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors, we have coupled patch-clamp recordings and reverse transcription followed by polymerase chain reaction amplification. AMPA receptors lacking the GluR2 subunit in a population of hippocampal neurons exhibited a strong inward rectification and were highly permeable to Ca2+.
Myocardial Hibernation: Adaptation to Ischemia
Authors: Heusch G , Schulz R
Published: December 2017

As long as myocardial blood flow, following a sudden reduction, remains above 30% of baseline, the myocardium can adapt to ischemia, i.e., recover metabolically, remain viable, and increase its contractile function during inotropic stimulation. This adaptive response to ischemia is termed "hibernation". The detailed mediators of such adaptation are unknown at present.
New Developments in Microneurography of Human C Fibers
Authors: Forster C , Schmelz M
Published: December 2017

Slowing of conduction velocity during the relative refractory period of an axon can be used to detect activation in human cutaneous nerve fibers. The method is highly sensitive and provides the means to identify individual unmyelinated afferent and efferent (sympathetic) units excited by different types of stimuli.
Integration Fields Beyond the Classical Receptive Field: Organization and Functional Properties
Authors: Li C-Y
Published: December 2017

The integration field outside the classical receptive field of retinal, geniculate, and cortical neurons shows various modulatory effects on cell activity. Interactions between the two fields underlie the transmission of luminance gradients and enable cortical neurons to analyze texture features and texture contrasts over an extensive area.
Chemotropic Factors Direct Regenerating Axons
Authors: Kuffler DP
Published: December 2017

Establishment and repair of a functional nervous system require an environment that permits, supports, and directs axon growth. Gradients of immobilized and diffusible molecules direct axon growth by attracting, deflecting, or inhibiting it. Some of these molecules act only at critical periods.
Role of Cardiac KATP Channels During Anoxia and Ischemia
Authors: Benndorf K , Thierfelder S , Doepner B , Gebhardt C , Hirche H
Published: December 2017

In isolated heart cells, maintained anoxia causes a transient opening of KATP channels. In the ischemic myocardium, this extra K+ conductance results in a decreased contractility and may be arrhythmogenic. Recent studies provide further evidence that the transient activity of KATP channels during anoxia is correlated with the time course of extracellular K+ accumulation during ischemia.
How We Smell: The Molecular and Cellular Bases of Olfaction
Authors: Nef Patrick
Published: December 2017

Three models for the perception of odor molecules are suggested for the first time by experimental data. These studies illustrate how the nose may smell. Moreover, they suggest additional role(s) for odor receptors within and outside the olfactory system.
Visual Pigments and Molecular Genetics of Color Blindness
Authors: Bowmaker J. K.
Published: December 2017

Red/green color blindness, found in ~1 in 15 men, is caused by the expression of hybrid genes coding for visual pigments. Spectral information from site-directed mutagenesis and recombinant expression has led to the possibility of correlating individual genotypes with psychophysical measurements of the severity of the deficiency.
Calcium Mobilization Systems During Neurogenesis
Authors: Yamashita Masayuki , Sugioka Miho
Published: December 2017

Neuroepithelial cells have Ca2+ mobilization systems that are activated by acetylcholine via muscarinic receptors and by extracellular ATP via P2U purinoceptors. The Ca2+ mobilization occurs during neurogenesis and diminishes in parallel with the declining of mitotic activities of the neuroepithelial cells. Capacitative Ca2+ influx also occurs with the Ca2+ mobilization.
Maxi-KCa, a Unique Member of the Voltage-Gated K Channel Superfamily
Authors: Toro L. , Wallner M. , Meera P. , Tanaka Y.
Published: December 2017

Large-conductance, voltage-, and Ca2+-sensitive K+ (maxi-KCa) channels regulate neuronal and smooth muscle excitability. Their pore-forming α-subunit shows similarities with voltage-gated channels and indeed can open in the practical absence of Ca2+. The NH2 terminus is unique, with a seventh transmembrane segment involved in β-subunit modulation. The long COOH terminus is implied in Ca2+ modulation.
Proteinase-Activated Receptors: New Functions for Old Enzymes
Authors: Böhm Stephan K. , McConalogue Karen , Kong Wuyi , Bunnett Nigel W.
Published: December 2017

Although proteases are traditionally viewed as degradative enzymes, characterization of a family of G protein-coupled receptors that are activated by proteolysis reveals a new role. Certain proteases function as signaling molecules that specifically regulate cells by cleaving and activating a family of proteinase-activated receptors.
Spatiotemporal Dynamics of Human Cognition
Authors: Michel Christoph M. , Seeck Margitta , Landis Theodor
Published: December 2017

It is still largely unknown how the complex cortical neural network of the human brain can process information so rapidly. Multichannel evoked potential recordings with millisecond time resolution and spatiotemporal analysis methods now allow us to address this question and to unravel the temporal dynamics of the large-scale neurocognitive networks.
P-450 Eicosanoids: A Novel Signaling Pathway Regulating Renal Function
Authors: Roman Richard J. , Alonso-Galicia Magdalena
Published: December 2017

Cytochrome P-450 enzymes primarily metabolize arachidonic acid to epoxyeicosatrienoic acids (EETs) and 20-hydroxyeicosatetraenoic acid (20-HETE) in the kidney. These compounds serve as second messengers that play a central role in the regulation of renal vascular tone and sodium reabsorption in the proximal tubule and thick ascending loop of Henle.
Bile Formation: a Concerted Action of Membrane Transporters in Hepatocytes and Cholangiocytes
Authors: Zsembery Akos , Thalhammer Theresia , Graf Jürg
Published: December 2017

A large number of membrane transport mechanisms in hepatocytes and cholangiocytes serves for the secretion of bile acids, various other organic anions, organic cations, lipids, and electrolytes. After their functional characterization, some of these mechanisms' individual transport molecules are now identified, allowing better understanding of inherited and acquired disorders of bile formation.
Interface Properties of Circumventricular Organs in Salt and Fluid Balance
Authors: Simon Eckhart
Published: December 2017

The “sensory” circumventricular organs, with their leaky blood-brain barriers, permit contact between brain neurons and blood-borne molecules. Body fluid balance and cardiovascular control involve established interface functions of subfornical organs. Their recently identified target functions for hormones released during digestion suggest that they may coordinate fluid and food intake.
Apoptosis in the Retina: The Silent Death of Vision
Authors: Remé Charlotte E. , Grimm Christian , Hafezi Farhad , Wenzel Andreas , Williams Theodore P.
Published: December 2017

Pathogenetic mechanisms of retinal degeneration include cell loss by apoptosis. This gene-regulated mode of single-cell death occurs in a number of widespread human diseases such as neurodegeneration. The knowledge of genes and signaling in retinal apoptosis is expanding and opens up therapeutic strategies to ameliorate blinding retinal diseases.
Ca2+-Activated Cl–Channels: A Newly Emerging Anion Transport Family
Authors: Fuller Catherine M. , Benos Dale J.
Published: December 2017

A new family of Cl–channels widely expressed in epithelia has been identified. These proteins are associated with Ca2+-sensitive conductive Cl–transport when heterologously expressed. This family may underlie the Ca2+-mediated Cl–conductance responsible for rescue of the cystic fibrosis knockout mouse from significant airway disease.
How a Turtle's Shell Helps It Survive Prolonged Anoxic Acidosis
Authors: Jackson Donald C.
Published: December 2017

Anoxic turtles accumulate high levels of lactate in blood. To avoid fatal acidosis, turtles exploit buffer reserves in their large mineralized shell. The shell acts by releasing calcium and magnesium carbonates and by storing and buffering lactic acid. Together with profound metabolic depression, shell buffering permits survival without oxygen for several months at 3°C.
Uncoupling Proteins: Do They Have a Role in Body Weight Regulation?
Authors: Dulloo Abdul.G. , Samec Sonia
Published: December 2017

Several members of the mitochondrial carrier protein family are classified as uncoupling proteins. In contrast to the uncoupling protein specific to brown adipose tissue (UCP1), the physiological role of skeletal muscle uncoupling proteins (UCP2 and UCP3) in weight regulation seems more closely associated with the regulation of lipids as fuel substrate than as mediators of adaptive thermogenesis.
Measurements of Vesicle Recycling in Central Neurons
Authors: Ryan Timothy A. , Reuter Harald
Published: December 2017

Neurotransmitter-containing vesicles in presynaptic nerve terminals are essential for synaptic transmission. The vesicles undergo a cycle that leads to transmitter release by exocytosis followed by endocytosis and refilling of the vesicles. Here we discuss new optical methods that have helped researchers study this cycle at functional and molecular levels, which is essential for our understanding of the regulation of synaptic transmission.
Implications of Mouse Genotype for Phenotype
Authors: Hickman-Davis Judy M.
Published: December 2017

Genetic engineering of inbred mice offers the capability to separate interactions of multiple genes that control host resistance to pathogens. An understanding of the negative impact that genetic variability of mouse substrains can have on data is necessary for the design of experiments to dissect out complicated gene interactions.
Energy and Water Balance at High Altitude
Authors: Westerterp Klaas R.
Published: December 2017

Many studies have shown that subjects lose significant amounts of body mass, fat mass as well as fat-free mass, during a climb to and/or a stay at high altitude. Altitude-induced weight loss is mainly caused by malnutrition due to hypoxia-related satiety, independent of acute mountain sickness.
Energizing Epithelial Transport with the Vacuolar H+-ATPase
Authors: Beyenbach Klaus W.
Published: December 2017

The Ussing model has long provided the conceptual foundation for understanding epithelial transport mechanisms energized by the Na+-K+-ATPase. Plasma membranes may also use the vacuolar (V-type) H+-ATPase as the primary energy source of membrane and epithelial transport. A pure electrogenic pump, the V-type H+-ATPase energizes not only membranes it inhabits but also other transport pathways via electrical coupling.
Surviving Anoxia With the Brain Turned On
Authors: Nilsson Göran E.
Published: December 2017

Crucian carp is one of few vertebrates that tolerate anoxia. It maintains brain ATP during anoxia partially by reducing ATP consumption. However, unlike turtles, which become comatose during anoxia, this fish remains physically active. This striking difference in anoxic survival strategy is reflected all the way down to the cellular level.
The Estrogen Trinity: Membrane, Cytosolic, and Nuclear Effects
Authors: Nadal Angel , Díaz Mario , Valverde Miguel A.
Published: December 2017

Estrogens have a wide array of biological effects, targeting both genomic and nongenomic mechanisms. Classically, the estrogen receptors activating the transcription machinery in the nucleus were thought to be distinct from the extranuclear estrogen receptors. Recently, this conceptual wall has started to be dismantled as the result of the identification of novel routes of estrogen action.
What Does the Brain Know About Blood Pressure?
Authors: Mifflin Steven W.
Published: December 2017

The integration of baroreceptor inputs within the central nervous system is modulated by a variety of inhibitory processes. It is proposed that, in hypertension, brain stem neurons adapt to increased excitatory baroreceptor inputs by increasing the efficacy of these inhibitory processes. Enhanced inhibition maintains some degree of reflex function in hypertension.
THE ETIOLOGY OF RICKETS
Authors: Park Edwards A.
Published: December 2017

Volume III, No. 1 (January, 1923): Page 127, line 12, instead of “tungsten arc” read “tungsten filament.”
Physical Properties of Small Arterial Vessels
Authors: Lamport Harold , Baez Silvio
Published: December 2017

Lamport, Harold, and Silvio Baez, “Physical Properties of Small Arterial Vessels” Page 341, volume 42, suppl. 5, Fig. 14, the ordinate should read where TT is dynes/ cm2, TT in I O2 dynes/cm2.
Hypotheses on physiological roles of prostaglandins.
Authors: Horton E W
Published: December 2017

Prostaglandin, a smooth muscle-stimulating depressor acidic lipid discovered int he human seminal plasma in 1935, is now used as a generic term for a family of closely related derivatives of prostanoic acid which are widely distributed in animal tissues. Prostaglandins are biosynthesized from arachidonic acid and dihomo-gamma-linolenic acid, both of which are derived from dietary linoleic acid. This finding provided a link to the observation that linoleic acid is an essential constituent of the diet. It is possible that prostaglandin compounds play a biochemical role fundamental to many, or all, animal cells. They have been implicated in sperm transport, menstruation, parturition, and control of placental blood flow. They may also play a role in the central nervous system, although this role may well be other than that of synaptic transmitter. Release of prostaglandin from various tissues is brought about by nerve stimulation. In adipose tissues, the amounts released may be sufficient to inhibit formation of cyclic AMP by the released noradrenaline, thus providing a local negative feedback mechanism. Prostaglandins also possibly play a role in muscular contractility, essential fatty acid deficiency, inhibition of lipid mobilization, atherosclerosis, and thrombosis.
Carotid Body: Structure and Function
Authors: Biscoe T. J.
Published: December 2017

Through an unfortunate error in make-up of the article “Carotid Body: Structure and Function,” by T. J. Biscoe, in the July issue of this journal, two sections of the review are out of order. To correct the error, the journal has reprinted pages 449–456. The corrected pages are bound in the front of the October issue.

Readers and librarians who casebind the journal should instruct their binders to remove pages 449–456 inclusive from the July issue and replace them with revised pages R449–R456 before completing the binding.

[See PDF for corrected pages]
Airway Obstruction and Collateral Ventilation
Authors: Macklem Peter T.
Published: December 2017

Peter T. Macklem, “Airway Obstruction and Collateral Ventilation,” p. 380, paragraph 5, line 1, should read:

Above a critical length-diameter ratio of 2−1/2 catenoid formation is impossible;

T. J. Biscoe, “Carotid Body: Structure and Function,” p. 449–456. See corrected pages (R449–R456) bound in the front of this issue (October).
Aspects of smooth muscle function in molluscan catch muscle
Authors: Twarog B. M.
Published: December 2017

1) Catch in Mytilus ABRM may be a specialization of a mechanism common to all muscles that gives rise to stretch resistance in the resting state. Catch appears to be due to actin myosin interaction. Since this interaction is regulated by nerves, it provides a convenient model for studying resting stretch resistance. 2) Studies of the structure of Mytilus ABRM revela two types of intercellular connections: a) direct connections between muscle fibers [these nexal (gap) junctions interconnect the muscle cells electrically]; b) muscle fiber-collagen-muscle fiber connections [these provide mechanical connections between muscle cells via collagen fibers]. The structure of Mytilus ABRM supports speculation that smooth muscle filaments are organized into contractile units. 3) A rise in cAMP levels occurs in response to the relaxing transmitter, serotonin. It is not certain whether the cAMP system directly controls the ability of the contractile proteins to interact or whether it regulates intracellular levels of Ca2+. 4) Calcium ions in activation are derived from two sources: an internal source, probably the sarcoplasmic reticulum, and an external source, across the muscle membrane. 5) The nature of catch remains in question, although most evidence favors the linkage hypothesis.
Transport of cholesterol
Authors: Norum K. R. , Berg T. , Helgerud P. , Drevon C. A.
Published: December 2017

.ur current model for cholesterol transport is summarized in Figure 10. In this figure we have put together the various steps in cholesterol transport that were described previously in this review. Under normal conditions, cholesterol metabolism and transport are well regulated. If the transport system is overloaded for a long time, however, hypercholesterolemia caused mainly by increased plasma LDL may develop in several species, including humans. Under such circumstances reverse transport of cholesterol may also fail, giving rise to deposits of cholesterol. Tissue macrophages may be responsible for this lipid accumulation, because receptor-mediated (adsorptive) endocytosis of lipoprotein-associated cholesterol in these cells is not under negative-feedback control. The deposits are mainly found in tissues poorly supplied with blood and lymph: the skin, tendons, the cornea, and arteries. Overload of cholesterol transport may be the result of too much fat and cholesterol in the diet, giving rise to cholesterol-rich lipoproteins from the gut and to increased production of liver (formula; see text) VLDL, which in humans ends up as LDL. In many individuals, however, no hypercholesterolemia is seen, even after eating large amounts of a "western" diet for decades; others may develop increased LDL on a relatively "prudent" diet. Obviously many of the factors and mechanisms in cholesterol transport are influenced by genetic factors. Although studies of several inborn errors of lipid metabolism have given information about some mechanisms, the quantitatively more important differences in genetic patterns, which determine whether or not a western diet will result in hyperlipidemia, are not well known. Perhaps studies of different forms of apoB and apoE and of HDL subgroups and hyper-alpha-lipoproteinemia will explain why certain individuals develop hypercholesterolemia and premature atherosclerosis. All the recent information related to cholesterol metabolism and transport gives rise to new questions. There are many problems of interest for future research: What are the metabolic differences between the apoB produced in the liver and that produced in the gut? To what extent is the protein moiety of LDL modified in the plasma of blood and lymph and in interstitial tissue? Are such modifications important to whether LDL uptake goes through the classic LDL pathway or through the macrophage (i.e., scavenger?) pathway? Are some changes in apoB important for liver recognition of LDL?(ABSTRACT TRUNCATED AT 400 WORDS)
Mechanisms of Ca2+ release from sarcoplasmic reticulum of skeletal muscle
Authors: Martonosi A. N.
Published: December 2017

Since the discovery of the ATP-dependent Ca2+ transport by SR a little over two decades ago, remarkable progress has been made in understanding the kinetic mechanism of Ca2+ transport and ATP hydrolysis and the role of phosphorylated enzyme intermediates in the energetics of active ion transport. Significant information has accumulated on the structure and composition of the SR membrane, on the primary amino acid sequence of the Ca2+-pump protein, and on the adaptive changes in the Ca2+-transport function during embryonic development and muscle activity. The discovery of the charge movement as a step in EC coupling and the use of novel optical probes for analyzing potential and calcium transients in living muscle changed the enigma of EC coupling into a well-defined problem that is clearly open to rational solutions. Studies on the structure, composition, and function of the isolated components of the T-SR system have just begun. The effectiveness of this approach will depend on successful maintenance of the functionally intact structure of the T-SR junction during the disruption of the muscle, which is required for the isolation of pure membrane elements. Reconstitution of a functionally competent junctional complex from isolated components is the ultimate aim of these studies, but the path toward that goal is so difficult that much of the mechanism of EC coupling may be solved by electrophysiologists, before reconstitution is achieved. The avalanche of information on Ca2+ releases induced by various agents under diverse and sometimes ill-defined conditions led to formulation of a series of hypothetical mechanisms. Of these, Ca2+-induced Ca2+ release promises to be an important element of the physiological Ca2+-release process, but few of the other proposed mechanisms can be eliminated from consideration at this stage. The impressive progress of the last few years has left several fundamental problems largely unsolved. Among these are the physical mode of translocation of Ca2+ across the membrane and the molecular mechanism of the coupling of Ca2+ transport to ATP hydrolysis; the regulation of the concentration of the Ca2+-pump protein and calcium in the SR of fast and slow skeletal, cardiac, and smooth muscles; the gating mechanisms that regulate the graded release of calcium from the SR and the composition and biochemical characterization of the triad; the role of SR membrane potential in the regulation of Ca2+ fluxes in vivo; the permeability of SR membranes in living muscle; the functional significance of protein-protein interactions in the SR with respect to Ca2+ transport and permeability control.(ABSTRACT TRUNCATED AT 400 WORDS)
Maternal and fetal responses to exercise during pregnancy
Authors: Lotgering F. K. , Gilbert R. D. , Longo L. D.
Published: December 2017

Exercise has numerous effects on the pregnant woman, the developing fetus, and the placenta. In turn, pregnancy affects the ability to perform physical activity. During pregnancy, increased metabolism at rest results almost exclusively from the gestational increase in mass. Because of this increase, a higher cardiorespiratory effort is required to perform a given amount of external work. One would expect the result to be some training effect, unless a more sedentary lifestyle is adopted. The possibility that maximal O2 consumption may increase during pregnancy has not been studied extensively, yet it is a most important variable that puts other changes in perspective. The sedentary lifestyle commonly adopted in late pregnancy in most western societies may reflect a cultural rather than a physiological phenomenon. In contrast to the physiological alterations in the mother and despite the reductions in uterine blood flow during maternal exercise, physiological changes in the fetus are small. Relatively minor changes occur in the blood concentrations of O2 and substrates during prolonged exhaustive exercise. In addition, despite a temperature increase of 1 to 2 degrees C, there is little evidence for significant alteration in fetal metabolism, cardiovascular hemodynamics, or blood catecholamine concentrations. These observations suggest that acute exercise normally does not represent a major stress for the fetus. Of course, most of the information concerning the fetus is derived from studies in experimental animals, particularly in sheep. In humans the upright position and increased uterine contractibility may affect the fetal responses differently. Virtually nothing is known about the physiological effects of exercise training on the fetus. The most likely effect may be a relatively small reduction in birth weight in some species, but this needs further investigation. Further studies are also needed for a more complete understanding of the mechanisms involved in the remarkably effective mechanisms that account for the relative homeostasis of the fetus during maternal exercise.