St Bartholomew's Hospital

About: St Bartholomew's Hospital is a healthcare organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Cancer. The organization has 11054 authors who have published 13229 publications receiving 501102 citations. The organization is also known as: St. Bartholomew's Hospital & The Royal Hospital of St Bartholomew.

Tissue substitutes in experimental radiation physics

Abstract: In this review of tissue substitute materials, the historical development of the important systems is traced from the early 1900's. Tabulations of the constituents, elemental compositions, specific gravities, and the photon and electron interaction characteristics of 64 materials are given together with recommendations of systems having useful simulation properties. Formulation and manufacturing procedures are described and possible future developments in both materials and phantom research are outlined.

Guiding Principles for Chronic Total Occlusion Percutaneous Coronary Intervention: A Global Expert Consensus Document

Abstract: Outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have improved because of advancements in equipment and techniques. With global collaboration and knowledge sharing, we have identified 7 common principles that are widely accepted as best practices for CTO-PCI. 1. Ischemic symptom improvement is the primary indication for CTO-PCI. 2. Dual coronary angiography and in-depth and structured review of the angiogram (and, if available, coronary computed tomography angiography) are key for planning and safely performing CTO-PCI. 3. Use of a microcatheter is essential for optimal guidewire manipulation and exchanges. 4. Antegrade wiring, antegrade dissection and reentry, and the retrograde approach are all complementary and necessary crossing strategies. Antegrade wiring is the most common initial technique, whereas retrograde and antegrade dissection and reentry are often required for more complex CTOs. 5. If the initially selected crossing strategy fails, efficient change to an alternative crossing technique increases the likelihood of eventual PCI success, shortens procedure time, and lowers radiation and contrast use. 6. Specific CTO-PCI expertise and volume and the availability of specialized equipment will increase the likelihood of crossing success and facilitate prevention and management of complications, such as perforation. 7. Meticulous attention to lesion preparation and stenting technique, often requiring intracoronary imaging, is required to ensure optimum stent expansion and minimize the risk of short- and long-term adverse events. These principles have been widely adopted by experienced CTO-PCI operators and centers currently achieving high success and acceptable complication rates. Outcomes are less optimal at less experienced centers, highlighting the need for broader adoption of the aforementioned 7 guiding principles along with the development of additional simple and safe CTO crossing and revascularization strategies through ongoing research, education, and training.

Effect of sustained exercise on plasma amino acid concentrations and on 5-hydroxytryptamine metabolism in six different brain regions in the rat.

Abstract: Sustained exercise to fatigue elicits no major differences either in plasma amino acid levels or in brain 5-hydroxytryptamine (5-HT) metabolism between sedentary and endurance-trained animals. Furthermore, 11 weeks of endurance training did not influence the maximal activity of the enzyme monoamine oxidase in the brain areas which were studied. In both sedentary and endurance-trained rats, sustained running to fatigue caused an increase in the plasma concentration ratio of free tryptophan/other large neutral amino acids and an increase in the concentration of tryptophan in the six brain areas that were studied. The increase was similar in the different regions of the brain and averaged 36%. Exercise caused an increase in the levels of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) in the brain stem (14 and 44% respectively) and hypothalamus (16 and 17% respectively) and an increase in the level of 5-HIAA in the hippocampus (21%) and striatum (28%). Exercise also caused an increase in the level of dopamine in the brain stem (56%) and hypothalamus (46%) and of nor adrenaline in the striatum (59%). Since the levels of 5-HT and dopamine were both increased in the brain stem and hypothalamus, it is possible that these changes may play important roles in the central effects of exercise, including both physical and mental fatigue and effects on mood.

Interactions Between Respiration and Circulation

Abstract: The sections in this article are: 1 Spontaneous Respiratory Variations in the Cardiovascular System 1.1 Arterial Blood Pressure 1.2 Heart Rate 1.3 Cardiac Output 1.4 Systemic Vascular Resistance 1.5 Pulmonary Hemodynamics 2 Central Nervous Control of Respiration and the Cardiovascular System 2.1 Receptors and Afferent Pathways 2.2 Cell Bodies and Efferent Pathways 2.3 Central Control of Sympathetic Efferent Activity 2.4 Descending Pathways to Spinal Sympathetic Outflow 3 Central and Local Peripheral Circulatory Control by Blood Gases 3.1 Central Effects 3.2 Peripheral Effects 4 Some Reflex Neural Control Mechanisms 4.1 Arterial Baroreceptors 4.2 Peripheral Arterial Chemoreceptors 4.3 Upper Airway Receptors 4.4 Facial Receptors 4.5 Cardiopulmonary Receptors 4.6 Overall Involvement of Cardiopulmonary Receptors 5 Reflex Cardiovascular Effects of Lung Inflation 5.1 Cardiac Responses 5.2 Changes in Systemic Vascular Resistance 5.3 Coronary Circulation 5.4 Nature of Pulmonary Receptors 6 Mechanisms of Respiratory Modulation 6.1 Pulmonary Vagal Reflex 6.2 Central Respiratory Neuronal Activity 6.3 Hypocapnia 7 Phasic Respiratory Modulation of Reflex Responses 7.1 Respiration 7.2 Heart Rate 8 Respiratory Modulation of Specific Inputs to Nervous System 8.1 Modulation by Hyperventilation 8.2 Modulation by Reflex Hypoventilation and Apnea 8.3 Interactions Between Carotid Baroreceptors and Chemoreceptors 9 Respiratory Modulation of Vagal and Sympathetic Efferent Fiber Activity 9.1 Activity in Cardiac Vagal Efferent Fibers 9.2 Activity in Sympathetic Efferent Nerves 9.3 Mechanisms of Central Integration 10 Respiratory Sinus Arrhythmia 10.1 Mechanisms 11 Some Examples of Respiratory-Circulatory Integrative Control 11.1 Effects of Deep Breath 11.2 Valsalva Maneuver 11.3 Acute Hypoxia 11.4 Hypocapnia 11.5 Hypercapnia 11.6 Asphyxia and Breath Holding 11.7 Breath-Hold Diving 12 Effects of Changes in the Cardiovascular System on Respiration 12.1 Respiration, Metabolism, and Cardiac Output 12.2 Hemorrhagic Hypotension 13 Medical Implications of Respiratory-Cardiovascular Interactions 13.1 Diving Response 13.2 Protective Effects of Defense Mechanisms 13.3 Exaggerated Defense Responses 13.4 Restoration of Normal Cardiac Rhythm 13.5 Sudden Infant Death Syndrome