Constriction: The act of constricting.Vasoconstriction: The physiological narrowing of BLOOD VESSELS by contraction of the VASCULAR SMOOTH MUSCLE.Constriction, Pathologic: The condition of an anatomical structure's being constricted beyond normal dimensions.Arterioles: The smallest divisions of the arteries located between the muscular arteries and the capillaries.Ductus Arteriosus: A fetal blood vessel connecting the pulmonary artery with the descending aorta.Vasoconstrictor Agents: Drugs used to cause constriction of the blood vessels.Reflex, Pupillary: Constriction of the pupil in response to light stimulation of the retina. It refers also to any reflex involving the iris, with resultant alteration of the diameter of the pupil. (Cline et al., Dictionary of Visual Science, 4th ed)Bronchoconstriction: Narrowing of the caliber of the BRONCHI, physiologically or as a result of pharmacological intervention.Amniotic Band Syndrome: A disorder present in the newborn infant in which constriction rings or bands, causing soft tissue depressions, encircle digits, extremities, or limbs and sometimes the neck, thorax, or abdomen. They may be associated with intrauterine amputations.Pupil: The aperture in the iris through which light passes.Vasodilation: The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.Muscle Tonus: The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. (Stedman, 25th ed)Muscle, Smooth, Vascular: The nonstriated involuntary muscle tissue of blood vessels.Pericarditis, Constrictive: Inflammation of the PERICARDIUM that is characterized by the fibrous scarring and adhesion of both serous layers, the VISCERAL PERICARDIUM and the PARIETAL PERICARDIUM leading to the loss of pericardial cavity. The thickened pericardium severely restricts cardiac filling. Clinical signs include FATIGUE, muscle wasting, and WEIGHT LOSS.Cardiomegaly: Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.Pia Mater: The innermost layer of the three meninges covering the brain and spinal cord. It is the fine vascular membrane that lies under the ARACHNOID and the DURA MATER.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Cerebral Arteries: The arterial blood vessels supplying the CEREBRUM.Mesenteric Arteries: Arteries which arise from the abdominal aorta and distribute to most of the intestines.Vascular Resistance: The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.Hyperesthesia: Increased sensitivity to cutaneous stimulation due to a diminished threshold or an increased response to stimuli.Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Vasomotor System: The neural systems which act on VASCULAR SMOOTH MUSCLE to control blood vessel diameter. The major neural control is through the sympathetic nervous system.15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid: A stable prostaglandin endoperoxide analog which serves as a thromboxane mimetic. Its actions include mimicking the hydro-osmotic effect of VASOPRESSIN and activation of TYPE C PHOSPHOLIPASES. (From J Pharmacol Exp Ther 1983;224(1): 108-117; Biochem J 1984;222(1):103-110)Phenylephrine: An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.Sciatic Neuropathy: Disease or damage involving the SCIATIC NERVE, which divides into the PERONEAL NERVE and TIBIAL NERVE (see also PERONEAL NEUROPATHIES and TIBIAL NEUROPATHY). Clinical manifestations may include SCIATICA or pain localized to the hip, PARESIS or PARALYSIS of posterior thigh muscles and muscles innervated by the peroneal and tibial nerves, and sensory loss involving the lateral and posterior thigh, posterior and lateral leg, and sole of the foot. The sciatic nerve may be affected by trauma; ISCHEMIA; COLLAGEN DISEASES; and other conditions. (From Adams et al., Principles of Neurology, 6th ed, p1363)Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Actomyosin: A protein complex of actin and MYOSINS occurring in muscle. It is the essential contractile substance of muscle.Arteries: The vessels carrying blood away from the heart.Microcirculation: The circulation of the BLOOD through the MICROVASCULAR NETWORK.Coronary Vessels: The veins and arteries of the HEART.Norepinephrine: Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.Neuralgia: Intense or aching pain that occurs along the course or distribution of a peripheral or cranial nerve.Cytokinesis: The process by which the CYTOPLASM of a cell is divided.Endothelin-1: A 21-amino acid peptide produced in a variety of tissues including endothelial and vascular smooth-muscle cells, neurons and astrocytes in the central nervous system, and endometrial cells. It acts as a modulator of vasomotor tone, cell proliferation, and hormone production. (N Eng J Med 1995;333(6):356-63)Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Potassium Chloride: A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Endothelium, Vascular: Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.Indomethacin: A non-steroidal anti-inflammatory agent (NSAID) that inhibits the enzyme cyclooxygenase necessary for the formation of prostaglandins and other autacoids. It also inhibits the motility of polymorphonuclear leukocytes.Acetylcholine: A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Myography: The recording of muscular movements. The apparatus is called a myograph, the record or tracing, a myogram. (From Stedman, 25th ed)Bronchial Spasm: Spasmodic contraction of the smooth muscle of the bronchi.Nitric Oxide: A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.Vasodilator Agents: Drugs used to cause dilation of the blood vessels.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Airway Resistance: Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Receptors, Adrenergic, alpha-2: A subclass of alpha-adrenergic receptors found on both presynaptic and postsynaptic membranes where they signal through Gi-Go G-PROTEINS. While postsynaptic alpha-2 receptors play a traditional role in mediating the effects of ADRENERGIC AGONISTS, the subset of alpha-2 receptors found on presynaptic membranes signal the feedback inhibition of NEUROTRANSMITTER release.Pulmonary Artery: The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.Muscle Contraction: A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.Adrenergic alpha-Agonists: Drugs that selectively bind to and activate alpha adrenergic receptors.Sciatic Nerve: A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Endothelins: 21-Amino-acid peptides produced by vascular endothelial cells and functioning as potent vasoconstrictors. The endothelin family consists of three members, ENDOTHELIN-1; ENDOTHELIN-2; and ENDOTHELIN-3. All three peptides contain 21 amino acids, but vary in amino acid composition. The three peptides produce vasoconstrictor and pressor responses in various parts of the body. However, the quantitative profiles of the pharmacological activities are considerably different among the three isopeptides.Hyperalgesia: An increased sensation of pain or discomfort produced by mimimally noxious stimuli due to damage to soft tissue containing NOCICEPTORS or injury to a peripheral nerve.Myosin Type II: The subfamily of myosin proteins that are commonly found in muscle fibers. Myosin II is also involved a diverse array of cellular functions including cell division, transport within the GOLGI APPARATUS, and maintaining MICROVILLI structure.Pericardiectomy: Surgical excision (total or partial) of a portion of the pericardium. Pericardiotomy refers to incision of the pericardium.Aorta: The main trunk of the systemic arteries.HydrazinesAngiotensin II: An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.Serotonin: A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.Thromboxane A2: An unstable intermediate between the prostaglandin endoperoxides and thromboxane B2. The compound has a bicyclic oxaneoxetane structure. It is a potent inducer of platelet aggregation and causes vasoconstriction. It is the principal component of rabbit aorta contracting substance (RCS).Mesenteric Veins: Veins which return blood from the intestines; the inferior mesenteric vein empties into the splenic vein, the superior mesenteric vein joins the splenic vein to form the portal vein.Methacholine Chloride: A quaternary ammonium parasympathomimetic agent with the muscarinic actions of ACETYLCHOLINE. It is hydrolyzed by ACETYLCHOLINESTERASE at a considerably slower rate than ACETYLCHOLINE and is more resistant to hydrolysis by nonspecific CHOLINESTERASES so that its actions are more prolonged. It is used as a parasympathomimetic bronchoconstrictor agent and as a diagnostic aid for bronchial asthma. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1116)Gastrulation: A process of complicated morphogenetic cell movements that reorganizes a bilayer embryo into one with three GERM LAYERS and specific orientation (dorsal/ventral; anterior/posterior). Gastrulation describes the germ layer development of a non-mammalian BLASTULA or that of a mammalian BLASTOCYST.Venules: The minute vessels that collect blood from the capillary plexuses and join together to form veins.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Analgesics: Compounds capable of relieving pain without the loss of CONSCIOUSNESS.Basilar Artery: The artery formed by the union of the right and left vertebral arteries; it runs from the lower to the upper border of the pons, where it bifurcates into the two posterior cerebral arteries.Retinal Artery: Central retinal artery and its branches. It arises from the ophthalmic artery, pierces the optic nerve and runs through its center, enters the eye through the porus opticus and branches to supply the retina.Receptors, Endothelin: Cell surface proteins that bind ENDOTHELINS with high affinity and trigger intracellular changes which influence the behavior of cells.Receptor, Endothelin A: A subtype of endothelin receptor found predominantly in the VASCULAR SMOOTH MUSCLE. It has a high affinity for ENDOTHELIN-1 and ENDOTHELIN-2.Cell Shape: The quality of surface form or outline of CELLS.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Pericardium: A conical fibro-serous sac surrounding the HEART and the roots of the great vessels (AORTA; VENAE CAVAE; PULMONARY ARTERY). Pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. The latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers.Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.Renal Artery: A branch of the abdominal aorta which supplies the kidneys, adrenal glands and ureters.rho-Associated Kinases: A group of intracellular-signaling serine threonine kinases that bind to RHO GTP-BINDING PROTEINS. They were originally found to mediate the effects of rhoA GTP-BINDING PROTEIN on the formation of STRESS FIBERS and FOCAL ADHESIONS. Rho-associated kinases have specificity for a variety of substrates including MYOSIN-LIGHT-CHAIN PHOSPHATASE and LIM KINASES.Nitroarginine: An inhibitor of nitric oxide synthetase which has been shown to prevent glutamate toxicity. Nitroarginine has been experimentally tested for its ability to prevent ammonia toxicity and ammonia-induced alterations in brain energy and ammonia metabolites. (Neurochem Res 1995:200(4):451-6)NG-Nitroarginine Methyl Ester: A non-selective inhibitor of nitric oxide synthase. It has been used experimentally to induce hypertension.Vena Cava, Inferior: The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs.Hypertrophy, Left Ventricular: Enlargement of the LEFT VENTRICLE of the heart. This increase in ventricular mass is attributed to sustained abnormal pressure or volume loads and is a contributor to cardiovascular morbidity and mortality.Dihydroergotamine: A 9,10alpha-dihydro derivative of ERGOTAMINE. It is used as a vasoconstrictor, specifically for the therapy of MIGRAINE DISORDERS.Muscle, Smooth: Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)Posterior Cerebral Artery: Artery formed by the bifurcation of the BASILAR ARTERY. Branches of the posterior cerebral artery supply portions of the OCCIPITAL LOBE; PARIETAL LOBE; inferior temporal gyrus, brainstem, and CHOROID PLEXUS.Miosis: Pupillary constriction. This may result from congenital absence of the dilatator pupillary muscle, defective sympathetic innervation, or irritation of the CONJUNCTIVA or CORNEA.Receptors, Adrenergic, alpha: One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Morphogenesis: The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.Bronchoconstrictor Agents: Agents causing the narrowing of the lumen of a bronchus or bronchiole.Peptides, Cyclic: Peptides whose amino and carboxy ends are linked together with a peptide bond forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS. Some of them are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).Pericarditis, Tuberculous: INFLAMMATION of the sac surrounding the heart (PERICARDIUM) due to MYCOBACTERIUM TUBERCULOSIS infection. Pericarditis can lead to swelling (PERICARDIAL EFFUSION), compression of the heart (CARDIAC TAMPONADE), and preventing normal beating of the heart.Nifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.Mice, Inbred C57BLReceptors, Adrenergic, alpha-1: A subclass of alpha-adrenergic receptors that mediate contraction of SMOOTH MUSCLE in a variety of tissues such as ARTERIOLES; VEINS; and the UTERUS. They are usually found on postsynaptic membranes and signal through GQ-G11 G-PROTEINS.Thromboxane-A Synthase: An enzyme found predominantly in platelet microsomes. It catalyzes the conversion of PGG(2) and PGH(2) (prostaglandin endoperoxides) to thromboxane A2. EC 5.3.99.5.Histamine: An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.Cyclooxygenase Inhibitors: Compounds or agents that combine with cyclooxygenase (PROSTAGLANDIN-ENDOPEROXIDE SYNTHASES) and thereby prevent its substrate-enzyme combination with arachidonic acid and the formation of eicosanoids, prostaglandins, and thromboxanes.Papio ursinus: A species of baboon in the family CERCOPITHECIDAE found in southern Africa. They are dark colored and have a variable social structure.Middle Cerebral Artery: The largest of the cerebral arteries. It trifurcates into temporal, frontal, and parietal branches supplying blood to most of the parenchyma of these lobes in the CEREBRAL CORTEX. These are the areas involved in motor, sensory, and speech activities.Myocytes, Cardiac: Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Ligation: Application of a ligature to tie a vessel or strangulate a part.Adrenergic alpha-Antagonists: Drugs that bind to but do not activate alpha-adrenergic receptors thereby blocking the actions of endogenous or exogenous adrenergic agonists. Adrenergic alpha-antagonists are used in the treatment of hypertension, vasospasm, peripheral vascular disease, shock, and pheochromocytoma.Renal Veins: Short thick veins which return blood from the kidneys to the vena cava.Hydroxyeicosatetraenoic Acids: Eicosatetraenoic acids substituted in any position by one or more hydroxy groups. They are important intermediates in a series of biosynthetic processes leading from arachidonic acid to a number of biologically active compounds such as prostaglandins, thromboxanes, and leukotrienes.Receptors, Thromboxane: Cell surface proteins that bind THROMBOXANES with high affinity and trigger intracellular changes influencing the behavior of cells. Some thromboxane receptors act via the inositol phosphate and diacylglycerol second messenger systems.Prazosin: A selective adrenergic alpha-1 antagonist used in the treatment of HEART FAILURE; HYPERTENSION; PHEOCHROMOCYTOMA; RAYNAUD DISEASE; PROSTATIC HYPERTROPHY; and URINARY RETENTION.Nitric Oxide Synthase: An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.Pupil Disorders: Conditions which affect the structure or function of the pupil of the eye, including disorders of innervation to the pupillary constrictor or dilator muscles, and disorders of pupillary reflexes.Ear, External: The outer part of the hearing system of the body. It includes the shell-like EAR AURICLE which collects sound, and the EXTERNAL EAR CANAL, the TYMPANIC MEMBRANE, and the EXTERNAL EAR CARTILAGES.Heart: The hollow, muscular organ that maintains the circulation of the blood.Pericardial Effusion: Fluid accumulation within the PERICARDIUM. Serous effusions are associated with pericardial diseases. Hemopericardium is associated with trauma. Lipid-containing effusion (chylopericardium) results from leakage of THORACIC DUCT. Severe cases can lead to CARDIAC TAMPONADE.Receptors, Thromboxane A2, Prostaglandin H2: A subclass of eicosanoid receptors that have specificity for THROMBOXANE A2 and PROSTAGLANDIN H2.Aorta, Thoracic: The portion of the descending aorta proceeding from the arch of the aorta and extending to the DIAPHRAGM, eventually connecting to the ABDOMINAL AORTA.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt: A colorimetric reagent for iron, manganese, titanium, molybdenum, and complexes of zirconium. (From Merck Index, 11th ed)Receptor, Endothelin B: A subtype of endothelin receptor found predominantly in the KIDNEY. It may play a role in reducing systemic ENDOTHELIN levels.Sympathetic Nervous System: The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.Nitroprusside: A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.Mesentery: A layer of the peritoneum which attaches the abdominal viscera to the ABDOMINAL WALL and conveys their blood vessels and nerves.Tocolytic Agents: Drugs that prevent preterm labor and immature birth by suppressing uterine contractions (TOCOLYSIS). Agents used to delay premature uterine activity include magnesium sulfate, beta-mimetics, oxytocin antagonists, calcium channel inhibitors, and adrenergic beta-receptor agonists. The use of intravenous alcohol as a tocolytic is now obsolete.Neural Tube: A tube of ectodermal tissue in an embryo that will give rise to the CENTRAL NERVOUS SYSTEM, including the SPINAL CORD and the BRAIN. Lumen within the neural tube is called neural canal which gives rise to the central canal of the spinal cord and the ventricles of the brain. For malformation of the neural tube, see NEURAL TUBE DEFECTS.Ventricular Remodeling: The geometric and structural changes that the HEART VENTRICLES undergo, usually following MYOCARDIAL INFARCTION. It comprises expansion of the infarct and dilatation of the healthy ventricle segments. While most prevalent in the left ventricle, it can also occur in the right ventricle.Microscopy, Video: Microscopy in which television cameras are used to brighten magnified images that are otherwise too dark to be seen with the naked eye. It is used frequently in TELEPATHOLOGY.Ketanserin: A selective serotonin receptor antagonist with weak adrenergic receptor blocking properties. The drug is effective in lowering blood pressure in essential hypertension. It also inhibits platelet aggregation. It is well tolerated and is particularly effective in older patients.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Calcium Channel Blockers: A class of drugs that act by selective inhibition of calcium influx through cellular membranes.Bronchi: The larger air passages of the lungs arising from the terminal bifurcation of the TRACHEA. They include the largest two primary bronchi which branch out into secondary bronchi, and tertiary bronchi which extend into BRONCHIOLES and PULMONARY ALVEOLI.Heart Failure: A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (VENTRICULAR DYSFUNCTION), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as MYOCARDIAL INFARCTION.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Lung Compliance: The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)Hypertension: Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.Ventricular Pressure: The pressure within a CARDIAC VENTRICLE. Ventricular pressure waveforms can be measured in the beating heart by catheterization or estimated using imaging techniques (e.g., DOPPLER ECHOCARDIOGRAPHY). The information is useful in evaluating the function of the MYOCARDIUM; CARDIAC VALVES; and PERICARDIUM, particularly with simultaneous measurement of other (e.g., aortic or atrial) pressures.Arteriovenous Anastomosis: A vessel that directly interconnects an artery and a vein, and that acts as a shunt to bypass the capillary bed. Not to be confused with surgical anastomosis, nor with arteriovenous fistula.Anoxia: Relatively complete absence of oxygen in one or more tissues.Thromboxanes: Physiologically active compounds found in many organs of the body. They are formed in vivo from the prostaglandin endoperoxides and cause platelet aggregation, contraction of arteries, and other biological effects. Thromboxanes are important mediators of the actions of polyunsaturated fatty acids transformed by cyclooxygenase.Prostaglandin Endoperoxides, Synthetic: Synthetic compounds that are analogs of the naturally occurring prostaglandin endoperoxides and that mimic their pharmacologic and physiologic activities. They are usually more stable than the naturally occurring compounds.Calcium Signaling: Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.Myocardial Contraction: Contractile activity of the MYOCARDIUM.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Prostaglandin H2: A cyclic endoperoxide intermediate produced by the action of CYCLOOXYGENASE on ARACHIDONIC ACID. It is further converted by a series of specific enzymes to the series 2 prostaglandins.Papaverine: An alkaloid found in opium but not closely related to the other opium alkaloids in its structure or pharmacological actions. It is a direct-acting smooth muscle relaxant used in the treatment of impotence and as a vasodilator, especially for cerebral vasodilation. The mechanism of its pharmacological actions is not clear, but it apparently can inhibit phosphodiesterases and it may have direct actions on calcium channels.Methoxamine: An alpha-1 adrenergic agonist that causes prolonged peripheral VASOCONSTRICTION.Thiopental: A barbiturate that is administered intravenously for the induction of general anesthesia or for the production of complete anesthesia of short duration.Fibrosis: Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury.Vigabatrin: An analogue of GAMMA-AMINOBUTYRIC ACID. It is an irreversible inhibitor of 4-AMINOBUTYRATE TRANSAMINASE, the enzyme responsible for the catabolism of GAMMA-AMINOBUTYRIC ACID. (From Martindale The Extra Pharmacopoeia, 31st ed)Adrenergic alpha-2 Receptor Agonists: Compounds that bind to and activate ADRENERGIC ALPHA-2 RECEPTORS.Porins: Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.Phentolamine: A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of RAYNAUD DISEASE and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease.Organ Size: The measurement of an organ in volume, mass, or heaviness.Viper Venoms: Venoms from SNAKES of the viperid family. They tend to be less toxic than elapid or hydrophid venoms and act mainly on the vascular system, interfering with coagulation and capillary membrane integrity and are highly cytotoxic. They contain large amounts of several enzymes, other factors, and some toxins.Cheek: The part of the face that is below the eye and to the side of the nose and mouth.Lymphatic System: A system of organs and tissues that process and transport immune cells and LYMPH.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Myocytes, Smooth Muscle: Non-striated, elongated, spindle-shaped cells found lining the digestive tract, uterus, and blood vessels. They are derived from specialized myoblasts (MYOBLASTS, SMOOTH MUSCLE).Diltiazem: A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on membrane functions.Hydronephrosis: Abnormal enlargement or swelling of a KIDNEY due to dilation of the KIDNEY CALICES and the KIDNEY PELVIS. It is often associated with obstruction of the URETER or chronic kidney diseases that prevents normal drainage of urine into the URINARY BLADDER.Aorta, Abdominal: The aorta from the DIAPHRAGM to the bifurcation into the right and left common iliac arteries.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Tocolysis: Any drug treatment modality designed to inhibit UTERINE CONTRACTION. It is used in pregnant women to arrest PREMATURE LABOR.Yohimbine: A plant alkaloid with alpha-2-adrenergic blocking activity. Yohimbine has been used as a mydriatic and in the treatment of ERECTILE DYSFUNCTION.Renal Circulation: The circulation of the BLOOD through the vessels of the KIDNEY.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Actins: Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.Sympathectomy, Chemical: Sympathectomy using chemicals (e.g., 6-hydroxydopamine or guanethidine) which selectively and reversibly destroy adrenergic nerve endings while leaving cholinergic nerve endings intact.Blood Circulation: The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.Venous Pressure: The blood pressure in the VEINS. It is usually measured to assess the filling PRESSURE to the HEART VENTRICLE.Peripheral Nerve Injuries: Injuries to the PERIPHERAL NERVES.Biological Factors: Endogenously-synthesized compounds that influence biological processes not otherwise classified under ENZYMES; HORMONES or HORMONE ANTAGONISTS.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.Adrenergic alpha-1 Receptor Agonists: Compounds that bind to and activate ADRENERGIC ALPHA-1 RECEPTORS.Pulmonary Circulation: The circulation of the BLOOD through the LUNGS.Arginine: An essential amino acid that is physiologically active in the L-form.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Respiratory Mechanics: The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.BelizeDelftia acidovorans: A species of gram-negative rod-shaped bacteria found ubiquitously and formerly called Comamonas acidovorans and Pseudomonas acidovorans. It is the type species of the genus DELFTIA.Aminohippuric Acids: A group of glycine amides of aminobenzoic acids.Nerve Compression Syndromes: Mechanical compression of nerves or nerve roots from internal or external causes. These may result in a conduction block to nerve impulses (due to MYELIN SHEATH dysfunction) or axonal loss. The nerve and nerve sheath injuries may be caused by ISCHEMIA; INFLAMMATION; or a direct mechanical effect.Pericarditis: Inflammation of the PERICARDIUM from various origins, such as infection, neoplasm, autoimmune process, injuries, or drug-induced. Pericarditis usually leads to PERICARDIAL EFFUSION, or CONSTRICTIVE PERICARDITIS.Rats, Inbred WKY: A strain of Rattus norvegicus used as a normotensive control for the spontaneous hypertensive rats (SHR).Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Amides: Organic compounds containing the -CO-NH2 radical. Amides are derived from acids by replacement of -OH by -NH2 or from ammonia by the replacement of H by an acyl group. (From Grant & Hackh's Chemical Dictionary, 5th ed)Propranolol: A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.Ear: The hearing and equilibrium system of the body. It consists of three parts: the EXTERNAL EAR, the MIDDLE EAR, and the INNER EAR. Sound waves are transmitted through this organ where vibration is transduced to nerve signals that pass through the ACOUSTIC NERVE to the CENTRAL NERVOUS SYSTEM. The inner ear also contains the vestibular organ that maintains equilibrium by transducing signals to the VESTIBULAR NERVE.Potassium Channel Blockers: A class of drugs that act by inhibition of potassium efflux through cell membranes. Blockade of potassium channels prolongs the duration of ACTION POTENTIALS. They are used as ANTI-ARRHYTHMIA AGENTS and VASODILATOR AGENTS.Splanchnic Circulation: The circulation of blood through the BLOOD VESSELS supplying the abdominal VISCERA.Blood Vessels: Any of the tubular vessels conveying the blood (arteries, arterioles, capillaries, venules, and veins).Methysergide: An ergot derivative that is a congener of LYSERGIC ACID DIETHYLAMIDE. It antagonizes the effects of serotonin in blood vessels and gastrointestinal smooth muscle, but has few of the properties of other ergot alkaloids. Methysergide is used prophylactically in migraine and other vascular headaches and to antagonize serotonin in the carcinoid syndrome.

Venous duplex scanning of the leg: range, variability and reproducibility. (1/854)

Despite the many studies on venous haemodynamics using duplex, only a few evaluated the normal values, variability and reproducibility. Therefore, the range and variability of venous diameter, compressibility, flow and reflux were measured. To obtain normal values, 42 healthy individuals (42 limbs, 714 vein segments) with no history of venous disease were scanned by duplex. To determine the reproducibility the intra-observer variability was measured in 11 healthy individuals (187 vein segments) and the inter-observer variability in 15 healthy individuals (255 vein segments) and 13 patients (169 vein segments) previously diagnosed with deep venous thrombosis. Of the 714 normal vein segments, 708 (99%) were traceable, including the crural veins. Of the traceable vein segments, 675 (95%) were compressible and in 696 (98%) flow was present. Of the 42 common femoral vein segments, in 25 (60%) the reflux duration exceeded 1.0 s, but in the other proximal vein segments the reflux duration was less than 1.0 s (95% confidence interval 3.0-10.0). With the exception of the distal long saphenous vein, in the distal vein segments the reflux duration was less than 0.5 s (95% confidence interval 3.5-8.2). The coefficient of variation of the diameter measurements ranged from 14 to 50% and that of the reflux measurements from 28 to 60%. The kappa-coefficient of the inter-observer variability in the classification of compressibility measurements in the patients was 0. 77 and that of the reflux measurements was 0.86. This study shows that almost all veins were compressible in healthy individuals, except the distal femoral veins. In healthy individuals the duration of reflux of the proximal veins was less than 1.0 s and in the distal veins it was less than 0.5 s. The inter-observer variability of the reflux and compressibility measurements in the patients was good.  (+info)

Peripheral muscle ergoreceptors and ventilatory response during exercise recovery in heart failure. (2/854)

Recent studies have suggested that the increased ventilatory response during exercise in patients with chronic heart failure was related to the activation of muscle metaboreceptors. To address this issue, 23 patients with heart failure and 7 normal subjects performed arm and leg bicycle exercises with and without cuff inflation around the arms or the thighs during recovery. Obstruction slightly reduced ventilation and gas exchange variables at recovery but did not change the kinetics of recovery of these parameters compared with nonobstructed recovery: half-time of ventilation recovery was 175 +/- 54 to 176 +/- 40 s in patients and 155 +/- 66 to 127 +/- 13 s in controls (P < 0.05, patients vs. controls, not significant within each group from baseline to obstructed recovery). We conclude that muscle metaboreceptor activation does not seem to play a role in the exertion hyperventilation of patients with heart failure.  (+info)

Inducible NO synthase inhibition attenuates shear stress-induced pulmonary vasodilation in the ovine fetus. (3/854)

Recent studies have suggested that type II (inducible) nitric oxide (NO) synthase (NOS II) is present in the fetal lung, but its physiological roles are uncertain. Whether NOS II activity contributes to the NO-mediated fall in pulmonary vascular resistance (PVR) during shear stress-induced pulmonary vasodilation is unknown. We studied the hemodynamic effects of two selective NOS II antagonists [aminoguanidine (AG) and S-ethylisothiourea (EIT)], a nonselective NOS antagonist [nitro-L-arginine (L-NNA)], and a nonselective vasoconstrictor (U-46619) on PVR during partial compression of the ductus arteriosus (DA) in 20 chronically prepared fetal lambs (mean age 132 +/- 2 days, term 147 days). At surgery, catheters were placed in the left pulmonary artery (LPA) for selective drug infusion, an ultrasonic flow transducer was placed on the LPA to measure blood flow, and an inflatable vascular occluder was placed loosely around the DA for compression. On alternate days, a brief intrapulmonary infusion of normal saline (control), AG, EIT, L-NNA, or U-46619 was infused in random order into the LPA. The DA was compressed to increase mean pulmonary arterial pressure (MPAP) 12-15 mmHg above baseline values and held constant for 30 min. In control studies, DA compression reduced PVR by 42% from baseline values (P < 0.01). L-NNA treatment completely blocked the fall in PVR during DA compression. AG and EIT attenuated the decrease in PVR by 30 and 19%, respectively (P < 0.05). Nonspecific elevation in PVR by U-46619 did not affect the fall in PVR during DA compression. Immunostaining for NOS II identified this isoform in airway epithelium and vascular smooth muscle in the late-gestation ovine fetal lung. We conclude that selective NOS II antagonists attenuate but do not block shear stress-induced vasodilation in the fetal lung. We speculate that stimulation of NOS II activity, perhaps from smooth muscle cells, contributes in part to the NO-mediated fall in PVR during shear stress-induced pulmonary vasodilation.  (+info)

Continuous versus intermittent portal triad clamping for liver resection: a controlled study. (4/854)

OBJECTIVE: The authors compared the intra- and postoperative course of patients undergoing liver resections under continuous pedicular clamping (CPC) or intermittent pedicular clamping (IPC). SUMMARY BACKGROUND DATA: Reduced blood loss during liver resection is achieved by pedicular clamping. There is controversy about the benefits of IPC over CPC in humans in terms of hepatocellular injury and blood loss control in normal and abnormal liver parenchyma. METHODS: Eighty-six patients undergoing liver resections were included in a prospective randomized study comparing the intra- and postoperative course under CPC (n = 42) or IPC (n = 44) with periods of 15 minutes of clamping and 5 minutes of unclamping. The data were further analyzed according to the presence (steatosis >20% and chronic liver disease) or absence of abnormal liver parenchyma. RESULTS: The two groups of patients were similar in terms of age, sex, nature of the liver tumors, results of preoperative assessment, proportion of patients undergoing major or minor hepatectomy, and nature of nontumorous liver parenchyma. Intraoperative blood loss during liver transsection was significantly higher in the IPC group. In the CPC group, postoperative liver enzymes and serum bilirubin levels were significantly higher in the subgroup of patients with abnormal liver parenchyma. Major postoperative deterioration of liver function occurred in four patients with abnormal liver parenchyma, with two postoperative deaths. All of them were in the CPC group. CONCLUSIONS: This clinical controlled study clearly demonstrated the better parenchymal tolerance to IPC over CPC, especially in patients with abnormal liver parenchyma.  (+info)

Changes in ionized calcium concentrations and acid-base status during abdominal aortic vascular surgery. (5/854)

Abdominal aortic surgery may produce significant haemodynamic instability (from a combination of factors: hypovolaemia, acid-base disturbances, vasoactive metabolite release from ischaemic tissues and hypocalcaemia). Calcium is often given after aortic unclamping to attenuate this instability. We studied 20 patients undergoing elective abdominal aortic surgery and observed a triphasic change in ionized calcium concentrations and acid-base status. Initially, during the cross-clamp period (when patients were cardiovascularly stable), ionized calcium concentrations decreased significantly (mean 1.06 (SD 0.08) to 0.91 (0.13) mmol litre-1; P < 0.01), while a significant metabolic acidosis developed (pH 7.38 (0.05) to 7.30 (0.05); P < 0.05). Second, release of the aortic cross-clamp resulted in further acidosis (pH 7.27 (0.05) (P < 0.05) mixed respiratory and metabolic) with a decrease in mean arterial pressure, with no change in ionized calcium concentrations. The third phase was associated with spontaneous restoration of acid-base status and ionized calcium concentrations to normal over 2 h. There was no correlation between units of blood given, volume of blood lost, fluid volume given or duration of aortic cross-clamping and degree of ionized hypocalcaemia. We conclude that ionized hypocalcaemia occurred during the cross-clamp period of aortic surgery, was unrelated to the volume of blood given and did not appear to be responsible for the changes in arterial pressure during surgery.  (+info)

Pararenal aortic aneurysms: the future of open aortic aneurysm repair. (6/854)

PURPOSE: As endovascular stent graft repair of infrarenal abdominal aortic aneurysms (AAAs) becomes more common, an increasing proportion of patients who undergo open operation will have juxtarenal aneurysms (JR-AAAs), which necessitate suprarenal crossclamping, suprarenal aneurysms (SR-AAAs), which necessitate renal artery reconstruction, or aneurysms with associated renal artery occlusive disease (RAOD), which necessitate repair. To determine the current results of the standard operative treatment of these patterns of pararenal aortic aneurysms, we reviewed the outcome of 257 consecutive patients who underwent operation for JR-AAAs (n = 122), SR-AAAs (n = 58), or RAOD (n = 77). METHODS: The patients with SR-AAAs and RAOD were younger (67.5 +/- 8.8 years) than were the patients with JR-AAAs (70.5 +/- 8.3 years), and more patients with RAOD were women (43% vs 21% for JR-AAAs and SR-AAAs). The patient groups were similar in the frequency of coronary artery and pulmonary disease and in most risk factors for atherosclerosis, except hypertension, which was more common in the RAOD group. Significantly more patients with RAOD had reduced renal function before surgery (51% vs 23%). Supravisceral aortic crossclamping (above the superior mesenteric artery or the celiac artery) was needed more often in patients with SR-AAAs (52% vs 39% for RAOD and 17% for JR-AAAs). Seventeen patients (7%) had undergone a prior aortic reconstruction. The most common renal reconstruction for SR-AAA was reimplantation (n = 37; 64%) or bypass grafting (n = 12; 21%) and for RAOD was transaortic renal endarterectomy (n = 71; 92%). Mean AAA diameter was 6.7 +/- 2.1 cm and was larger in the JR-AAA (7.1 +/- 2.1 cm) and SR-AAA (6.9 +/- 2.1 cm) groups as compared with the RAOD group (5.9 +/- 1.7 cm). RESULTS: The overall mortality rate was 5.8% (n = 15) and was the same for all the groups. The mortality rate correlated (P <.05) with hematologic complications (bleeding) and postoperative visceral ischemia or infarction but not with aneurysm group or cardiac, pulmonary, or renal complications. Renal ischemia duration averaged 31.6 +/- 21.6 minutes and was longer in the SR-AAA group (43.6 +/- 38.9 minutes). Some postoperative renal function loss occurred in 104 patients (40.5%), of whom 18 (7.0%) required dialysis. At discharge or death, 24 patients (9.3%) still had no improvement in renal function and 11 of those patients (4.3%) remained on dialysis. Postoperative loss of renal function correlated (P <.05) with preoperative abnormal renal function and duration of renal ischemia but not with aneurysm type, crossclamp level, or type of renal reconstruction. CONCLUSION: These results showed that pararenal AAA repair can be performed safely and effectively. The outcomes for all three aneurysm types were similar, but there was an increased risk of loss of renal function when preoperative renal function was abnormal. These data provide a benchmark for expected treatment outcomes in patients with these patterns of pararenal aortic aneurysmal disease that currently can only be managed with open repair.  (+info)

Should initial clamping for abdominal aortic aneurysm repair be proximal or distal to minimise embolisation? (7/854)

OBJECTIVES: to determine whether clamping proximally or distally on the infrarenal aorta during abdominal aortic aneurysm (AAA) repair increases the overall embolic potential. MATERIALS AND METHODS: a sheath was placed in the mid-infrarenal aorta of 16 dogs. In eight animals a cross-clamp was placed at the aortic trifurcation, and in another eight animals it was placed in the immediate subrenal position. Under fluoroscopy blood flow within the infrarenal aorta was evaluated by contrast and particle injections. Grey-scale analysis was used to calculate contrast density. Particle distribution was followed fluoroscopically and confirmed pathologically. RESULTS: fifty-seven+/-24% of injected contrast remained within the aorta with distal clamping while 97+/-7% did so with proximal clamping (p<0.01). With distal aortic clamping 6.2+/-1. 3 out of 10 injected particles remained within the aorta after 15 seconds and only 0.8+/-0.8 remained after 5 min. With proximal aortic clamping, all 10 of the particles remained within the aortic lumen for the full 5 minutes (p<0.001). CONCLUSIONS: initial distal clamping minimises distal embolisation, but may result in renal and/or visceral embolisation. Initial proximal clamping prevents proximal embolisation and does not promote distal embolisation. We recommend initial proximal clamping in aortic aneurysm surgery to minimise the overall risk of embolisation.  (+info)

Comparative analysis of NMR and NIRS measurements of intracellular PO2 in human skeletal muscle. (8/854)

1H NMR has detected both the deoxygenated proximal histidyl NdeltaH signals of myoglobin (deoxyMb) and deoxygenated Hb (deoxyHb) from human gastrocnemius muscle. Exercising the muscle or pressure cuffing the leg to reduce blood flow elicits the appearance of the deoxyMb signal, which increases in intensity as cellular PO2 decreases. The deoxyMb signal is detected with a 45-s time resolution and reaches a steady-state level within 5 min of pressure cuffing. Its desaturation kinetics match those observed in the near-infrared spectroscopy (NIRS) experiments, implying that the NIRS signals are actually monitoring Mb desaturation. That interpretation is consistent with the signal intensity and desaturation of the deoxyHb proximal histidyl NdeltaH signal from the beta-subunit at 73 parts per million. The experimental results establish the feasibility and methodology to observe the deoxyMb and Hb signals in skeletal muscle, help clarify the origin of the NIRS signal, and set a stage for continuing study of O2 regulation in skeletal muscle.  (+info)

TY - JOUR. T1 - Supraceliac, but not infrarenal, aortic cross-clamping upregulates neutrophil integrin CD11b. AU - Hill, Gary E.. AU - Mihalakakos, Paul J.. AU - Spurzem, John R.. AU - Baxter, Timothy B.. PY - 1995. Y1 - 1995. N2 - Objective: To evaluate the effects of supraceliac and infrarenal aortic cross-clamping on the expression of neutrophil integrin CD11b (a marker of systemic cytokine release). Design: Two groups, determined by anatomic placement of aortic cross-clamp. Laboratory personnel were blinded as to group assignment. Setting: University teaching and community hospitals. Laboratory facilities used were university and Veterans Affairs medical centers. Participants: Patients scheduled for aortic surgery. Interventions: Blood sampling was performed at baseline, after 30 minutes of aortic cross-clamp duration, 30 and 90 minutes after reperfusion (for tumor necrosis factor-α plasma levels in infrarenal cross-clamp group), and at baseline and 90 minutes reperfusion (for neutrophil ...
BACKGROUND: To assess the variations in end-tidal CO2 in response to aortic cross-clamping and the relationship with systolic arterial pressure (SAP) changes induced by unclamping. METHODS: Thirty-three patients undergoing infrarenal aortic abdominal aneurysm repair by aorto-aortic prothetic bypass were prospectively studied. All patients were anesthetized with i.v. midazolam (0.05 mg ...
Constriction I, a Paper Collage on Canvas, by Gustavo Ortiz from United Kingdom, Not for sale, Price is $, Size is 13.8 x 9.8 x 0.7 in.
(KudoZ) German to English translation of Einschnürung, Überprüfung auf ....: necking/constriction, check for - [Welding - Engineering (general) (Tech/Engineering)].
Complex surgical procedures requiring long cross clamp times for complete repair are often patients only chance for survival and better quality of life. Decisions about operability are often difficult, as research has shown that XCL time is an independent predictor of mortality and morbidity in patients undergoing cardiac surgeries [1, 2, 4]. Our results demonstrate that while high in relation to less complex surgeries, a 12.4 % mortality in these complex, high risk patients is lower than that reported by studies in the literature addressing longer XCL times. Nissinen et al. observed a 31.5 % 30-day mortality rate in their patients with XCL times greater than 240 min [2]. Furthermore, Al-Sarraf et al. found that high risk patients (EuroScore ≥ 6) with XCL times ,90 min and those with XCL times , 60 min and ≤ 90 min were respectively 4.7 and 3.1 times more likely to die than those with XCL times ≤ 60 min [1]. Doenst et al. found that XCL times greater than 30 min were associated with a ...
throat constriction - MedHelps throat constriction Center for Information, Symptoms, Resources, Treatments and Tools for throat constriction. Find throat constriction information, treatments for throat constriction and throat constriction symptoms.
Synonyms for constriction hyperemia in Free Thesaurus. Antonyms for constriction hyperemia. 1 synonym for hyperemia: hyperaemia. What are synonyms for constriction hyperemia?
Synonyms for constriction in Free Thesaurus. Antonyms for constriction. 21 synonyms for constriction: tightness, pressure, narrowing, reduction, squeezing, restriction, constraint, cramp, compression, blockage, stenosis, limitation. What are synonyms for constriction?
Nelly Frossard is the author of this article in the Journal of Visualized Experiments: Technique of Minimally Invasive Transverse Aortic Constriction in Mice for Induction of Left Ventricular Hypertrophy
TY - JOUR. T1 - The retroperitoneal, left flank approach to the supraceliac aorta for difficult and repeat aortic reconstructions. AU - Mills, Joseph L. AU - Fujitani, Roy M.. AU - Taylor, Spence M.. PY - 1991. Y1 - 1991. N2 - Between 1986 and 1990, 11 patients with relative or absolute contraindications to standard infrarenal reconstructions underwent supraceliac aortofemoral bypass. The operation was performed through a left-flank incision extended into the eleventh intercostal space with retroperitoneal and extrapleural dissection. Indications included multiple failed infrarenal reconstructions in four patients, previous removal of infected aortofemoral bypass graft with failure of extra-anatomic bypass in five patients, prior para-aortic lymph node dissection and radiotherapy in one patient, and aortic aneurysmal disease proximal to the renal arteries in one patient. Bypass conduits included either a bifurcated Dacron graft or a tube graft to the left femoral artery with a femorofemoral ...
Aim. To study the effects of N-acetyleysteine and ischemic preconditioning on the portal triad clamping compared to arterial and portal clamping alone.Methods. Eighty EPM 1-Wistar rats were randomized into two groups, depending on inclusion (Group 1) or not (Group 2) of the bile duct in the hepatic vascular pedicle occlusion. Each group was divided into four subgroups as follows. IR 1: 20 minutes after celiotomy, the pedicle containing vascular elements and bile duct to the left lateral and median liver lobes was occluded for 40 minutes, followed by 30 minutes of reperfusion. IPC 1: after 10 minutes of ischemia and 10 minutes of reperfusion, the ischemic preconditioning period, the rats were submitted to the same procedure described for IR 1 Group. NAC 1: the rats received N-acetylcysteine (150 mg/kg) 15 minutes before 40 minutes of ischemia and 5 minutes before 30 minutes of reperfusion. SHAM 1: the hepatic pedicle for the lateral and median liver lobes was dissected after 20 minutes, the bile ...
20-HETE is pro-proliferative, -inflammatory, and -migratory (49, 66), all of which contribute to the pathogenesis of systemic and pulmonary hypertension. Although the increase in 20-HETE by hypoxia inhibited acute hypoxia-induced pulmonary artery constriction (2, 69), it time and dose dependently increased superoxide production from NADPH oxidases in the cultured pulmonary artery endothelial cells (37). Also, studies have reported that 20-HETE-induced superoxide mediated flow-induced constriction of cerebral arteries (58). Our current results further demonstrated that inhibition of 20-HETE biosynthesis by DDMS decreased mitochondrial superoxide generation and conversely application of 20-HETE to endothelium denuded pulmonary arteries for 12 h elicited superoxide generation from mitochondria but not from extra-mitochondrial sources. This led us to the question of how does 20-HETE increase mitochondrial superoxide generation? One potential explanation was 20-HETE passed through the gap junctions ...
A data storage system that includes a positioning system for positioning the write/read mechanism and the storage medium of the data storage device with respect to each other in first and second predefined directions. The positioning system comprises a positioning apparatus comprising microfabricated first and second positioning assemblies. The positioning system further comprises a controller to position a positionable support structure of the first positioning assembly in a first predefined direction within a range of positioning that is larger than the range of movement of a moveable support structure of the first positioning assembly by controlling (A) a stationary support structure clamp in clamping and unclamping the positionable structure to and from the support structure, (B) a moveable structure clamp in clamping and unclamping the positionable support structure to and from the moveable support structure, and (C) the movement of the moveable support structure. In one embodiment, one of the
for a single guy !. great work , ozan .. easy to see why you get all the big jobs ,. you deliver !. well done .. -- david - only thru kindness can this world be whole . If we dont succeed we run the risk of failure. Dan Quayle ...
Aortic cross clamping is associated with spinal cord ischemia. This study used a rat spinal cord ischemia model to investigate the effect of distal aortic pressure on spinal cord perfusion. Male Sprague-Dawley rats (n=12) were divided into thre
Bleeding is a major problem during liver resection. Vascular inflow occlusion, also known as Pringle maneuver, has been commonly employed to reduce blood loss during liver surgery. However, Pringle maneuver might cause ischaemic insult to the remnant liver and lead to post-operative liver dysfunction.. The investigators hypothesize that liver resection without the use of vascular inflow occlusion (Pringle maneuver) is associated with lower postoperative complications rate.. The aim of this study is to evaluate whether elective open liver resection without vascular inflow occlusion (Pringle Maneuvre) would lead to a reduction of post-operative surgical complications in patient with hepatocellular carcinoma.. Eligible patients undergoing liver resection in the Prince of Wales Hospital will be recruited and randomized into 2 study arms comparing the effect of Pringle maneuver. ...
Looking for online definition of Segmental arteries in the Medical Dictionary? Segmental arteries explanation free. What is Segmental arteries? Meaning of Segmental arteries medical term. What does Segmental arteries mean?
Dipeptidyl peptidase-4 (DPP-4) inhibitors are hypoglycemic agents. DPP-4 inhibitor has cardioprotective effects after transverse aortic constriction (TAC), but role of DPP-4 on cardiac fibrosis after TAC is not well known. Our aim was to determine the effects of DPP-4 on cardiac fibrosis in murine TAC model. Wild-type mice and DPP-4 knockout mice were subjected to TAC. Wild-type mice were then treated with vehicle or DPP-4 inhibitor. DPP-4 activities in serum and heart tissue were significantly increased at 2 weeks after TAC, but they were significantly decreased by DPP-4 inhibitor treatment ...
Retinal vascular occlusion occurs when one of the vessels carrying blood to or from your retina becomes blocked or contains a blood clot.
Primos Maximum, Remington Versa Max, 12 Ga, .660 Constriction Designed to increase the range and pattern density of your favorite turkey gun! The Jelly Head Max
I need some advice creating a constriction ability for a snake character using entangle, or is there some other power I should use to do this. 6E
Pringle, Gary Johnson, who is currently in a tube at Chutney on the Fritzs branch of Tesco, (other shopping emporia are available, guys and girls), has revealed that he is not looking forward to his visit to a strangers stomach. I know that it...
Background: Aortic valve stenosis (AS) and hypertension (HT) both lead to left ventricular (LV) hypertrophy as a consequence of chronic pressure overload, but differences in LV geometric adaptation have been suggested.. Methods: To study the influence of type of pressure overload on LV structure, we pooled baseline echocardiograms and clinical information from HT patients with electrocardiographic LV hypertrophy in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study and asymptomatic AS patients in the Simvastatin Ezetimibe in Aortic Stenosis (SEAS) study. Patients , 45 years, or with diabetes, known cardiovascular disease or , grade 1 aortic valve regurgitation were excluded. HT was defined as history of HT or clinic blood pressure ,140/90 mmHg. The study population was divided according to type of pressure overload: From LIFE HT (n=265); from SEAS AS (n=761) or combined HT and AS (n=649). LV geometry was assessed from LV mass/height2.7 (LV hypertrophy if , 49.2 g/m2.7 ...
Four weeks of aortic banding resulted in significant hypertrophy in rats. This was evident from a significant increase in LVm/BW ratios. Furthermore, the hypertrophy was concentric in nature as evident from significant increases in the IVS and LVPW, an indication of increased septal and posterior wall thickness, respectively, at both systole and diastole. There was no change observed in LVID, an indication of increased chamber size, at systole and diastole. Results of the current study are consistent with results from our previous study (4). Treatment of aortic-banded rats with 2.5 mg·kg−1·day−1 resveratrol completely prevented development of hypertrophy because there was a normalization of the increase in left ventricle-to-body weight ratio. Resveratrol treatment also prevented concentric remodeling by normalizing IVS and LVPW at both systole and diastole. The beneficial effects of resveratrol in preventing PO-induced cardiac hypertrophy are consistent with another recent study, which ...
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Handprinted in the UK, 100%Heavy Cotton Fruit of the Loom Constriction tshirt in BlackThe printing wont fade or crack even when tumble dried so your shirt will stay as soft and silky for years to come. an Ideal gift for anyone interested in constriction Sizes are Small 35 - 37, Medium 38 - 40, Large 40 - 41, XL 44 - 46, XXL 47 - 49, XXXL 50 -52
MedicalExpress will run as a continuous flow journal, a characteristic shared by no other Brazilian periodical. Accepted articles will be submitted to language polishing, composition, and submitted to authors for final approval. As soon as this is completed, articles will be made public. It is expected that accepted articles would be published approximately 30 days after acceptance.
Sentence Examples with the word constriction: Often the head is retractile, and a constriction of flexible cuticle distal to it is termed a neck: in Philodinaceae there are a series of thin flexible rings…
ZTR Control Systems new BOA™-WS (Bolt-on Adhesion™-Excitation/Wheel Slip Control System) is designed to boost tractive effort on EMD Dash-2 locomotiv...
Introduction: We report our experience with laparoscopic major liver resection in Korea based on a multicenter retrospective study. Materials and methods: Data from 1,009 laparoscopic liver resections conducted from 2001 to 2011 were retrospectively collected. Twelve tertiary medical centers with specialized hepatic surgeons participated in this study. Results: Among 1,009 laparoscopic liver resections, major liver resections were performed in 265 patients as treatment for hepatocellular carcinoma, metastatic tumor, intrahepatic duct stone, and other conditions. The most frequently performed procedure was left hemihepatectomy (165 patients), followed by right hemihepatectomy (53 patients). Pure laparoscopic procedure was performed in 190 patients including 19 robotic liver resections. Hand-assisted laparoscopic liver resection was performed in three patients and laparoscopy-assisted liver resection in 55 patients. Open conversion was performed in 17 patients (6.4 %). Mean operative time and ...
Emergency endovascular aneurysm repair (eEVAR) for ruptured abdominal aortic aneurysm (rAAA) must be carried out instantly. This requires firm logistics that include the ability to cross-clamp the aorta without delay. The present article focuses on the technique of balloon control of the aorta in eEVAR with aspects on indications as well as the organization of this type of vascular service. Transfemoral insertion of the occlusion balloon under local anesthesia is advocated and described. The use of dual balloons shortens the time of visceral ischemia without necessitating repeat declamping until the aneurysm has been completely excluded. Staged declamping upon completion is necessary just as in open repair. A "balloon test" is suggested to better identify those high risk patients with a rAAA who may benefit from endovascular rAAA repair.. ...
One-kidney, one clip (1K1C) and two-kidney, one clip (2K1C) Goldblatt hypertension was produced in rats by placing 0.30, 0.25, or 0.20 mm silver clips on the left renal artery. Mean arterial pressure (MAP) and plasma renin activity (PRA) were measured in conscious rats 24 to 28 days after clipping. The MAP in control rats (n = 38) was 116 +/- 1 mm Hg (mean +/- SEM). The 0.30, 0.25, and 0.20 mm clips produced MAPs of 133 +/- 2, 161 +/- 5, and 189 +/- 5 mm Hg, respectively, in 1K1C rats, and 123 +/- 2, 129 +/- 3, and 172 +/- 5 mm Hg in 2K1C rats (n = 17-20). When 1K1C and 2K1C groups were compared, MAP was significantly greater in 1K1C rats at all clip sizes. No treatment groups PRA was different than control (4.8 +/- 0.4 ng AI/ml/hr), except for the 0.20 mm 2K1C rats (16.2 +/- 3.1 ng AI/ml/hr). Renal artery pressure (RAP) was measured in another series of experiments and was not different from control in all but the 0.20 mm 1K1C rats. With identical clip sizes, 2K1C rats showed smaller pressure ...
Gastroenterology Research and Practice is a peer-reviewed, Open Access journal that provides a forum for researchers and clinicians working in the areas of gastroenterology, hepatology, pancreas and biliary, and related cancers. The journal welcomes submissions on the physiology, pathophysiology, etiology, diagnosis, and therapy of gastrointestinal diseases.
Serotonin, in addition to its fundamental role as a neurotransmitter, plays a critical role in the cardiovascular system, where it is thought to be involved in the development of cardiac hypertrophy and failure. Indeed, we recently found that mice with deletion of monoamine oxidase A had enhanced levels of blood and cardiac 5-HT, which contributed to exacerbation of hypertrophy in a model of experimental pressure overload. 5-HT2A receptors are expressed in the heart and mediate a hypertrophic response to 5-HT in cardiac cells. However, their role in cardiac remodeling in vivo and the signaling pathways associated are not well understood. In the present study, we evaluated the effect of a selective 5-HT2A receptor antagonist, M100907, on the development of cardiac hypertrophy induced by transverse aortic constriction (TAC). Cardiac 5-HT2A receptor expression was transiently increased after TAC, and was recapitulated in cardiomyocytes, as observed with 5-HT2A in situ labeling by immunohistochemistry.
Neurosurgery. 2010 Sep;67(3 Suppl Operative):ons102-7; discussion ons107. doi: 10.1227/01.NEU.0000383152.50183.81. Clinical Trial
JOURNAL «ANGIOLOGY AND VASCULAR SURGERY» №3 2017, VOLUME 23: Oxidative carbonylation of proteins in experimental hind-limb ischaemia-reperfusion injury
Definition of posterior basal segmental artery of left/right lung. Provided by Stedmans medical dictionary and Drugs.com. Includes medical terms and definitions.
Acute aortic occlusion is an emergent vascular condition not encountered routinely. Given its varied presentations, including neurovascular deficits and mimicking an acute abdomen, the diagnosis is often delayed causing increased morbidity and mortality. We present a case of acute abdominal aortic occlusion masquerading as sudden onset lower extremity pain and weakness in an 86-year-old female requiring emergent thrombectomy. This is only the second case report to discuss the use of point-of-care ultrasound to expedite diagnosis and management. ...
UCL Discovery is UCLs open access repository, showcasing and providing access to UCL research outputs from all UCL disciplines.
The Glissonean pedicle transection method has been reported to shorten operation time, reduce intraoperative blood loss, and minimize surgical risks in HCC patients undergoing hepatectomy 22. The Glissonean approach may therefore be more beneficial for HCC patients undergoing curative resection than other hilar vascular control methods such as the Pringle maneuver. However, in a large series, only 17.1% of patients underwent major hepatectomy involving two or more segments, with most patients (80.3%) undergoing segmentectomy or subsegmentectomy18. Our patient cohort differs in the extent of liver resection as well as including only patients with large (, 5 cm) nodular HCCs. 56% Of the 25 patients in our Glissonean group, 14 (56%) underwent removal of more than 2.5 segments (right trisegmetectomy).. To our best knowledge, our study is the first to compare the surgical effectiveness and safety of Glissonean transection with the Pringle maneuver in patients with large HCC undergoing radical ...
A method and device for occluding a patients ascending aorta, maintaining circulation of oxygenated blood in the patient and delivering cardioplegic fluid to arrest the patients heart. An aortic occlusion catheter has an occluding member for occluding the ascending aorta. The aortic occlusion catheter passes through a cannula. Delivery of oxygenated blood is accomplished through either the cannula or the aortic occlusion catheter.
Since the 1950s, several investigators have published reports of patients with dysphagia who had associated lower esophageal ringlike constrictions, but each investigator had a different opinion as to the cause and nature of these rings. In 1953, Ingelfinger and Kramer believed that these rings occurred as a result of a contraction by an over...
... with one or two annular constrictions to prevent it from falling off. Before each molt, a new button will have developed inside ...
Frication is difficult to produce or to distinguish because the voicing in the glottis and the constriction in the pharynx are ... and incomplete constriction at the epiglottis, as would be required to produce epiglottal fricatives, generally results in ...
The constriction of blood vessels is called vasoconstriction, it prevents the body from losing warmth. ...
Similar to the subspecies indica and inaurita, but is distinguished by its larger size and narrower postorbital constriction[14 ...
At this centromeric constriction the two halves of the chromosome, the sister chromatids, are held together until late ... During mitosis the centromeres can be seen during the metaphase stage as a constriction at the chromosome. ...
The segmental constrictions shallow. Spiracles black. Extensile organs on the twelfth segment small. The larva is broader than ...
Situations that can cause asphyxia include but are not limited to: the constriction or obstruction of airways, such as from ...
This is likely due to constriction of the afferent arteriole of the glomerulus, resulting in decreased glomerular filtration ...
... with a high-power individual they will also commonly exhibit social inhibition by inhibiting their postural constriction and ...
A number of theories exist for why it occurs including constrictions in blood vessels, viral infections, and autoimmune ... A number of theories exist including constrictions in blood vessels, viral infections, autoimmune reactions.[3] ...
constriction - Proto-Tai tones take on various tone values and contours in modern Tai languages. These tonal splits are ...
"Chromosome number and secondary constriction variation in 51 accessions of a citrus germplasm bank". Brazilian Journal of ...
Raynaud's disease - a rare peripheral vascular disorder of constriction of the peripheral blood vessels, in the fingers and ...
Watanabe S, De Zan T, Ishizaki T, Narumiya S (Apr 2013). "Citron kinase mediates transition from constriction to abscission ... bridge microtubules between the two daughter cells and is thus required for successful transition from constriction to ...
In asthma, the constriction of the bronchi can result in a difficulty in breathing giving shortness of breath; this can lead to ...
Salmeterol, a LABA, treats constriction of the airways. The combination of both is meant to be used as maintenance therapy and ...
... and measuring the pressure differential across the constriction gives the flow rate. It is basically a crude form of Venturi ... either by measuring the differential pressure within a constriction, or by measuring static and stagnation pressures to derive ... and pressure sensors measure the differential pressure before and within the constriction. This method is widely used to ... other than positive-displacement flowmeters rely on forces produced by the flowing stream as it overcomes a known constriction ...
There are segments of dilatations with trapped uncoagulated blood between the constrictions before complete occlusion.[8] Both ... Closure of the umbilical artery by vasoconstriction consists of multiple constrictions which increase in number and degree with ... the partial constrictions and the ultimate closure are mainly produced by muscle cells of the outer circular layer.[3] In ...
When the pulmonary capillary pressure remains elevated chronically (for at least 2 weeks), the lungs become even more resistant to pulmonary edema because the lymph vessels expand greatly, increasing their capability of carrying fluid away from the interstitial spaces perhaps as much as 10-fold. Therefore, in patients with chronic mitral stenosis, pulmonary capillary pressures of 40 to 45 mm Hg have been measured without the development of lethal pulmonary edema.[Guytun and Hall physiology] Hypoxia exists when there is a reduced amount of oxygen in the tissues of the body. Hypoxemia refers to a reduction in PO2 below the normal range, regardless of whether gas exchange is impaired in the lung, CaO2 is adequate, or tissue hypoxia exists. There are several potential physiologic mechanisms for hypoxemia, but in patients with COPD the predominant one is V/Q mismatching, with or without alveolar hypoventilation, as indicated by PaCO2. Hypoxemia caused by V/Q mismatching as seen in COPD is relatively ...
Other snakes kill their prey by constriction.[72] Still others swallow their prey whole and alive.[17]:81[72] ...
Tidal velocities passing through constrictions caused by reefs, sand bars and low islands commonly exceed 1-2 m/s (3-6.5 ft/s ...
When blood pressure is increased in the blood vessels and the blood vessels distend, they react with a constriction; this is ... as it positions a vessel in a preconstricted state that allows other factors to induce additional constriction or dilation to ... endothelial cell in the tunica intima of an artery is stretched it is likely that the endothelial cell may signal constriction ...
"17 beta-Estradiol attenuates acetylcholine-induced coronary arterial constriction in women but not men with coronary heart ...
... begins with the contraction of the muscles attached to the rib cage; this causes an expansion in the chest cavity. Then takes place the onset of contraction of the diaphragm, which results in expansion of the intrapleural space and an increase in negative pressure according to Boyle's law. This negative pressure generates airflow because of the pressure difference between the atmosphere and alveolus. Air enters, inflating the lung through either the nose or the mouth into the pharynx (throat) and trachea before entering the alveoli.[citation needed] Other muscles that can be involved in inhalation include:[2] ...
It occurs predominantly by delayed (or absent) constriction of the lower body blood vessels, which is normally required to ...
The simplest derivation is to first ignore gravity and consider constrictions and expansions in pipes that are otherwise ...
Surgical intervention is still the treatment of choice when the patient has the symptoms or signs of pericardial constriction ... Surgical intervention is still the treatment of choice when the patient has the symptoms or signs of pericardial constriction ... Surgical intervention is still the treatment of choice when the patient has the symptoms or signs of pericardial constriction ... Persistent tuberculous pericarditis will lead to pericardial constriction due to chronic granulomatous inflammation of the ...
having the most readily useful vacuum constriction devices videos. *why almost everything you have learned all about bathmate ...
Oral motor/facial exercises may be used to improve function in weakened muscles or to reduce constriction associated with ...
... breathing rates and the dilation and constriction of blood vessels. ...
It is typically described as a choking pain or a feeling of constriction, pressure and tightness in the chest on the left side ...
In the area where the hole for supplying gasoline is formed, the tube has a constriction. a diffuser. Here the flow rate ...
... as well as constrictions, or occasionally fine fissures; the dried transverse surfaces exhibit several equilaterally concentric ...
Pathologic Constriction (Stenosis) 03/2007. 1. Hyperglycemia 02/2006. 1. Reperfusion Injury 02/2006. ...
Characterized by squeezing sensation, tightness, pressure, constriction, burning or fullness. in the chest.. Infant patients ...
Pathologic Constriction Medicine & Life Sciences * Lipids Medicine & Life Sciences * Carotid Arteries Medicine & Life Sciences ...
Such tight constriction does not allow for proper circulation of blood and oxygen. The Gimp now has three strikes against him ...
... which are normally brought on by blood vessel constriction. These are complications that come for every week or a yr, after ...
Visual field testing shows constriction and central or paracentral scotomas [7]. There are no pathognomonic ...
... constriction, and internalization [25]. Treatment with CTB induced a dose-dependent decrease in QD entry into microglia (Figure ...
... with sensing protein and represents to find gastroesophageal engorgement intense to failure without disease Constriction. In a ...
... pain in the chest and also a constriction of the arteries in the body. ...
Helps in constriction of blood vessels during excessive bleeding. 2. Mineralocorticoids. Regulates metabolism of Na & K and ...
Caffeine is thought to produce constriction of cerebral blood vessels and serves to counteract the sedative effect of ... Caffeine is thought to produce constriction of cerebral blood vessels and serves to counteract the sedative effect of ... Caffeine is thought to produce constriction of cerebral blood vessels and serves to counteract the sedative effect of ...
Upper limit prevents dangerous vaso constriction/tourniquet effect. = SAFE AND EFFECTIVE. FAST CYCLE TIME. RecoverPump offers ...
This constriction is what traps the fluid inside your penis and causes the edema to appear. ...
causing constriction of the blood vessels: also vasoconstrictive n. a nerve or drug causing such constriction vasoconstriction ... Vasoconstrictor - Vas o*con*strict or, a. (Physiol.) Causing constriction of the blood vessels; as, the vasoconstrictor nerves ... stimulation of which causes vascular constriction. * * * va·so·con·stric·tor .vā zō kən strik tər n an agent (as a sympathetic ... stimulation of which causes constriction of the blood vessels to which they go. These nerves are also called {vasohypertonic ...
Constriction of resistance arteries was found to be correlated with the level of hypertension, and the responses were ... Constriction of resistance arteries was found to be correlated with the level of hypertension, and the responses were ... Constriction of resistance arteries was found to be correlated with the level of hypertension, and the responses were ... Constriction of resistance arteries was found to be correlated with the level of hypertension, and the responses were ...
Vascular constriction of capillaries and blood flow.. Microdermabrasion. Is a fairly simple, painless, non-invasive, skin ...
The first phase is constriction of the blood vessels, low blood to the brain. Secondary, you get dilation and thats where you ... The first phase is constriction of the blood vessels, low blood to the brain. Secondary, you get dilation and thats where you ...
  • The effects of QC-15 were also assessed in a model of neuropathic pain, induced by constriction of the common sciatic nerve using 4 chromic sutures. (queensu.ca)
  • Bleeding disordersand recommendations of good clinical practice on the management of the pa - promptly and appropriately is essential during hospitalization;therefore, be neglected.axis with a testosterone assayquestionnaire (i.e. total score 20 or less, a subjectiveEditorial Katherine Esposito, Maria Ida Maiorino, The Newspaper of AMD 2012;15:69-74 generic cialis Vacuum constriction devices (VCD) are widely availablea stoneâobtaining and maintaining âerection. (diepongauerin.at)
  • You explain to them that the corset was killing you, that you suffered constant back-ache, that the adults constriction about your waist had so jammed the contents of the abdomen down upon the organs at the bottom, as to produce a sense of bearing down, heat, and pain. (99beers.com)
  • Exercise-induced bronchial asthma, for example, causes airway constriction during physical activity, whereas occupational asthma is triggered from inhaling fumes or dangerous gases on the job. (starprogram.net)
  • Meget tyder på, at den kendte model for en globaliseret vækstøkonomi er kommet til kort. (2dgf.dk)
  • Oplægget vil præsentere en model for praktisk implementering af Verdensmålene via en virksomheds eller institutions strategi og forretningsplan med eksempel fra VandCenter Syd. (2dgf.dk)