Selective cerebral perfusion prevents abnormalities in glutamate cycling and neuronal apoptosis in a model of infant deep hypothermic circulatory arrest and reperfusion.

PubMed

Kajimoto, Masaki; Ledee, Dolena R; Olson, Aaron K; Isern, Nancy G; Robillard-Frayne, Isabelle; Des Rosiers, Christine; Portman, Michael A

2016-11-01

Deep hypothermic circulatory arrest is often required for the repair of complex congenital cardiac defects in infants. However, deep hypothermic circulatory arrest induces neuroapoptosis associated with later development of neurocognitive abnormalities. Selective cerebral perfusion theoretically provides superior neural protection possibly through modifications in cerebral substrate oxidation and closely integrated glutamate cycling. We tested the hypothesis that selective cerebral perfusion modulates glucose utilization, and ameliorates abnormalities in glutamate flux, which occur in association with neuroapoptosis during deep hypothermic circulatory arrest. Eighteen infant male Yorkshire piglets were assigned randomly to two groups of seven (deep hypothermic circulatory arrest or deep hypothermic circulatory arrest with selective cerebral perfusion for 60 minutes at 18℃) and four control pigs without cardiopulmonary bypass support. Carbon-13-labeled glucose as a metabolic tracer was infused, and gas chromatography-mass spectrometry and nuclear magnetic resonance were used for metabolic analysis in the frontal cortex. Following 2.5 h of cerebral reperfusion, we observed similar cerebral adenosine triphosphate levels, absolute levels of lactate and citric acid cycle intermediates, and carbon-13 enrichment among three groups. However, deep hypothermic circulatory arrest induced significant abnormalities in glutamate cycling resulting in reduced glutamate/glutamine and elevated γ-aminobutyric acid/glutamate along with neuroapoptosis, which were all prevented by selective cerebral perfusion. The data suggest that selective cerebral perfusion prevents these modifications in glutamate/glutamine/γ-aminobutyric acid cycling and protects the cerebral cortex from apoptosis. © The Author(s) 2016.

US FDA perspective on regulatory issues affecting circulatory assist devices.

PubMed

Sapirstein, Wolf; Chen, Eric; Swain, Julie; Zuckerman, Bram

2006-11-01

There has been a rapid development in mechanical circulatory support systems in the decade since the US FDA first approved a mechanical device to provide the circulatory support lacking from a failing heart. Devices are presently approved for marketing by the FDA to replace a failing ventricle, the Ventricular Assist Device or the entire heart, Total Artificial Heart. Contemporaneous with, and permitted by, improvement in technology and design, devices have evolved from units located extracorporeally to paracorporeal systems and totally implanted devices. Clinical studies have demonstrated a parallel improvement in the homeostatic adequacy of the circulatory support provided. Thus, while the circulatory support was initially tolerated for short periods to permit recovery of cardiac function, this technology eventually provided effective circulatory support for increasing periods that permitted the FDA to approve devices for bridging patients in end-stage cardiac failure awaiting transplant and eventually a device for destination therapy where patients in end-stage heart failure are not cardiac transplant candidates. The approved devices have relied on displacement pumps that mimic the pulsatility of the physiological system. Accelerated development of more compact devices that rely on alternative pump mechanisms have challenged both the FDA and device manufacturers to assure that the regulatory requirements for safety and effectiveness are met for use of mechanical circulatory support systems in expanded target populations. An FDA regulatory perspective is reviewed of what can be a potentially critical healthcare issue.

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

ERIC Educational Resources Information Center

National Evaluation Systems, Inc., Amherst, MA.

This module on the circulatory system is one of 17 modules designed for individualized instruction in health occupations education programs at both the secondary and postsecondary levels. It is part of an eight-unit subset on anatomy and physiology within the set of 17 modules. Following a preface which explains to the student how to use the…

38 CFR 4.62 - Circulatory disturbances.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Circulatory disturbances. 4.62 Section 4.62 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances...

38 CFR 4.62 - Circulatory disturbances.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Circulatory disturbances. 4.62 Section 4.62 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances...

38 CFR 4.62 - Circulatory disturbances.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Circulatory disturbances. 4.62 Section 4.62 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances...

38 CFR 4.62 - Circulatory disturbances.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Circulatory disturbances. 4.62 Section 4.62 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances...

38 CFR 4.62 - Circulatory disturbances.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Circulatory disturbances. 4.62 Section 4.62 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.62 Circulatory disturbances...

Surgical implications of portal venous system malformation

PubMed Central

Marks, Charles

1974-01-01

The significance of congenital abnormalities in predisposing to portal hypertension and variceal haemorrhage needs to be remembered when these effects manifest in childhood, as portal venography will permit elucidation of the complicated congenital developmental abnormalities underlying the pathological condition and permit rational surgical amelioration. In the presence of portal hypertension the development of a collateral venous circulation may be represented by a hepatopetal or hepatofugal circulatory pattern and will closely parallel the developmental areas where portal and systemic venous circulations meet, being representative of the embryological anastomosis between the vitelloumbilical system and the posterior cardinal system of veins. ImagesFig. 3Fig. 5Fig. 6 PMID:4614690

Medical care expenditures for selected circulatory diseases: opportunities for reducing national health expenditures.

PubMed

Hodgson, T A; Cohen, A J

1999-10-01

Circulatory system diseases are a significant burden in terms of morbidity, mortality, and use of health care services. This article presents total, per capita, and per condition US medical care expenditures in 1995 for circulatory diseases according to sex, age, and type of health service. Total personal health care expenditures estimated by the Health Care Financing Administration for each type of health care service are separated into components to estimate patient expenditures by age, sex, primary medical diagnosis, and health care service for all diseases of the circulatory system, heart disease, coronary heart disease, congestive heart failure, hypertensive disease, and cerebrovascular disease. Expenditures for circulatory diseases totaled $127.8 billion in 1995 (17% of all personal health care expenditures), $486 per capita, and $1,636 per condition. Approximately one half of expenditures was for hospital care and 20% was for nursing home care. Heart disease accounted for 60% of circulatory expenditures. Expenditures increased with age and reached 35% of expenditures among persons aged 85 years and older, which was almost $7,000 per capita. These relationships vary somewhat according to the specific circulatory disease, type of health care, and age. Expenditures increase with age and circulatory diseases can be expected to command an increasing share of national health expenditures as the number and proportion of the population that is elderly grows. The alteration of lifestyles and medical interventions provide many opportunities to prevent circulatory diseases and to reduce national health expenditures.

Health care utilization and costs for diseases of the circulatory system in a corporate setting.

PubMed

Tsai, S P; Bernacki, E J; Reedy, S M; Miller, K E

1988-01-01

This article presents the health care utilization and costs for diseases of the circulatory system among 14,162 employees and their spouses based on medical insurance claims data analysis. Diseases of the circulatory system ranked first among insurance claims and costs accounting for 23% ($4.6 million) of the plan's total health care costs ($19.7 million) for the 1984 policy year. Overall, 57% of these expenditures were for hospital care, the proportion for hospital costs being as high as 64% for heart diseases and as low as 20% for hypertension. Male employees had higher utilization for both in-hospital and out-patient services than females. Utilization rates and costs dramatically increased for individuals 50 years or older. Costs for surgical and diagnostic procedures amounted to 8% of the total costs of circulatory system disorders. This article provides an example of the utility of claims analysis for morbidity surveillance. The analyses and parameters measured herein can be viewed as prerequisites to the development of health care management and health promotion strategies aimed at reducing health care cost for diseases of the circulatory system in a corporate setting.

Analyses of Sox-B and Sox-E Family Genes in the Cephalopod Sepia officinalis: Revealing the Conserved and the Unusual

PubMed Central

Focareta, Laura; Cole, Alison G.

2016-01-01

Cephalopods provide an unprecedented opportunity for comparative studies of the developmental genetics of organ systems that are convergent with analogous vertebrate structures. The Sox-family of transcription factors is an important class of DNA-binding proteins that are known to be involved in many aspects of differentiation, but have been largely unstudied in lophotrochozoan systems. Using a degenerate primer strategy we have isolated coding sequence for three members of the Sox family of transcription factors from a cephalopod mollusk, the European cuttlefish Sepia officinalis: Sof-SoxE, Sof-SoxB1, and Sof-SoxB2. Analyses of their expression patterns during organogenesis reveals distinct spatial and temporal expression domains. Sof-SoxB1 shows early ectodermal expression throughout the developing epithelium, which is gradually restricted to presumptive sensory epithelia. Expression within the nervous system appears by mid-embryogenesis. Sof-SoxB2 expression is similar to Sof-SoxB1 within the developing epithelia in early embryogenesis, however appears in largely non-overlapping expression domains within the central nervous system and is not expressed in the maturing sensory epithelium. In contrast, Sof-SoxE is expressed throughout the presumptive mesodermal territories at the onset of organogenesis. As development proceeds, Sof-SoxE expression is elevated throughout the developing peripheral circulatory system. This expression disappears as the circulatory system matures, but expression is maintained within undifferentiated connective tissues throughout the animal, and appears within the nervous system near the end of embryogenesis. SoxB proteins are widely known for their role in neural specification in numerous phylogenetic lineages. Our data suggests that Sof-SoxB genes play similar roles in cephalopods. In contrast, Sof-SoxE appears to be involved in the early stages of vasculogenesis of the cephalopod closed circulatory system, a novel role for a member of this gene family. PMID:27331398

A Multiscale Closed-Loop Cardiovascular Model, with Applications to Heart Pacing and Hemorrhage

NASA Astrophysics Data System (ADS)

Canuto, Daniel; Eldredge, Jeff; Chong, Kwitae; Benharash, Peyman; Dutson, Erik

2017-11-01

A computational tool is developed for simulating the dynamic response of the human cardiovascular system to various stressors and injuries. The tool couples zero-dimensional models of the heart, pulmonary vasculature, and peripheral vasculature to one-dimensional models of the major systemic arteries. To simulate autonomic response, this multiscale circulatory model is integrated with a feedback model of the baroreflex, allowing control of heart rate, cardiac contractility, and peripheral impedance. The performance of the tool is demonstrated in two scenarios: increasing heart rate by stimulating the sympathetic nervous system, and an acute 10 percent hemorrhage from the left femoral artery.

Evaluation of exercise-respiratory system modifications and preliminary respiratory-circulatory system integration scheme

NASA Technical Reports Server (NTRS)

Gallagher, R. R.

1974-01-01

The respiratory control system, functioning as an independent system, is presented with modifications of the exercise subroutine. These modifications illustrate an improved control of ventilation rates and arterial and compartmental gas tensions. A very elementary approach to describing the interactions of the respiratory and circulatory system is presented.

A microfluidic circulatory system integrated with capillary-assisted pressure sensors.

PubMed

Chen, Yangfan; Chan, Ho Nam; Michael, Sean A; Shen, Yusheng; Chen, Yin; Tian, Qian; Huang, Lu; Wu, Hongkai

2017-02-14

The human circulatory system comprises a complex network of blood vessels interconnecting biologically relevant organs and a heart driving blood recirculation throughout this system. Recreating this system in vitro would act as a bridge between organ-on-a-chip and "body-on-a-chip" and advance the development of in vitro models. Here, we present a microfluidic circulatory system integrated with an on-chip pressure sensor to closely mimic human systemic circulation in vitro. A cardiac-like on-chip pumping system is incorporated in the device. It consists of four pumping units and passive check valves, which mimic the four heart chambers and heart valves, respectively. Each pumping unit is independently controlled with adjustable pressure and pump rate, enabling users to control the mimicked blood pressure and heartbeat rate within the device. A check valve is located downstream of each pumping unit to prevent backward leakage. Pulsatile and unidirectional flow can be generated to recirculate within the device by programming the four pumping units. We also report an on-chip capillary-assisted pressure sensor to monitor the pressure inside the device. One end of the capillary was placed in the measurement region, while the other end was sealed. Time-dependent pressure changes were measured by recording the movement of the liquid-gas interface in the capillary and calculating the pressure using the ideal gas law. The sensor covered the physiologically relevant blood pressure range found in humans (0-142.5 mmHg) and could respond to 0.2 s actuation time. With the aid of the sensor, the pressure inside the device could be adjusted to the desired range. As a proof of concept, human normal left ventricular and arterial pressure profiles were mimicked inside this device. Human umbilical vein endothelial cells (HUVECs) were cultured on chip and cells can respond to mechanical forces generated by arterial-like flow patterns.

Measurement of mean circulatory filling pressure and vascular compliance in domestic pigs.

PubMed

Ogilvie, R I; Zborowska-Sluis, D; Tenaschuk, B

1990-06-01

To measure mean circulatory filling pressure (Pmcf), a balloon was placed in the right atrium of seven pentobarbital sodium-anesthetized open-chest pigs for transient occlusion of flow combined with mechanical transfer of blood from the arterial to the venous circulation. Equilibration occurred within 6-8 s at a pressure at 12.3 +/- 0.3 (SE) mmHg after a 2.9 +/- 0.2 ml/kg transfer of blood. In another group of pentobarbital sodium-anesthetized closed-chest pigs, acetylcholine (ACh) was used to induce cardiac arrest. The Pmcf was 11.6 +/- 1.0 mmHg in the 7:17 pigs that arrested for 6-8 s. In four isoflurane-anesthetized closed-chest pigs, the Pmcf was 12.0 +/- 1.0 mmHg after terminal cardiac arrest induced by KCl. The pressure gradient for venous return [Pmcf--right atrial pressure (Pra)] averaged 5.9 +/- 0.2 mmHg. Total vascular compliance estimated from plots of Pmcf at base line, 5, and 10 ml/kg increases in circulating volume was 2.1 +/- 0.3 and 3.5 +/- 0.9 ml.kg-1.mmHg-1 in the balloon and ACh groups, respectively compared with 2.8 +/- 0.4 ml.kg-1.mmHg-1 using a volume infusion-withdrawal method without circulatory arrest. The use of ACh for the estimate of Pmcf in the pig is not recommended because of failure to consistently induce circulatory arrest and probable failure to achieve sufficient equilibrium of vascular pressures 6-8 s postarrest when it occurs.

Mathematical multi-scale model of the cardiovascular system including mitral valve dynamics. Application to ischemic mitral insufficiency

PubMed Central

2011-01-01

Background Valve dysfunction is a common cardiovascular pathology. Despite significant clinical research, there is little formal study of how valve dysfunction affects overall circulatory dynamics. Validated models would offer the ability to better understand these dynamics and thus optimize diagnosis, as well as surgical and other interventions. Methods A cardiovascular and circulatory system (CVS) model has already been validated in silico, and in several animal model studies. It accounts for valve dynamics using Heaviside functions to simulate a physiologically accurate "open on pressure, close on flow" law. However, it does not consider real-time valve opening dynamics and therefore does not fully capture valve dysfunction, particularly where the dysfunction involves partial closure. This research describes an updated version of this previous closed-loop CVS model that includes the progressive opening of the mitral valve, and is defined over the full cardiac cycle. Results Simulations of the cardiovascular system with healthy mitral valve are performed, and, the global hemodynamic behaviour is studied compared with previously validated results. The error between resulting pressure-volume (PV) loops of already validated CVS model and the new CVS model that includes the progressive opening of the mitral valve is assessed and remains within typical measurement error and variability. Simulations of ischemic mitral insufficiency are also performed. Pressure-Volume loops, transmitral flow evolution and mitral valve aperture area evolution follow reported measurements in shape, amplitude and trends. Conclusions The resulting cardiovascular system model including mitral valve dynamics provides a foundation for clinical validation and the study of valvular dysfunction in vivo. The overall models and results could readily be generalised to other cardiac valves. PMID:21942971

Viscoelasticity of blood and viscoelastic blood analogues for use in polydymethylsiloxane in vitro models of the circulatory system.

PubMed

Campo-Deaño, Laura; Dullens, Roel P A; Aarts, Dirk G A L; Pinho, Fernando T; Oliveira, Mónica S N

2013-01-01

The non-Newtonian properties of blood are of great importance since they are closely related with incident cardiovascular diseases. A good understanding of the hemodynamics through the main vessels of the human circulatory system is thus fundamental in the detection and especially in the treatment of these diseases. Very often such studies take place in vitro for convenience and better flow control and these generally require blood analogue solutions that not only adequately mimic the viscoelastic properties of blood but also minimize undesirable optical distortions arising from vessel curvature that could interfere in flow visualizations or particle image velocimetry measurements. In this work, we present the viscoelastic moduli of whole human blood obtained by means of passive microrheology experiments. These results and existing shear and extensional rheological data for whole human blood in the literature enabled us to develop solutions with rheological behavior analogous to real whole blood and with a refractive index suited for PDMS (polydymethylsiloxane) micro- and milli-channels. In addition, these blood analogues can be modified in order to obtain a larger range of refractive indices from 1.38 to 1.43 to match the refractive index of several materials other than PDMS.

Representations of the Human Circulatory System

ERIC Educational Resources Information Center

Lopez-Manjon, Asuncion; Angon, Yolanda Postigo

2009-01-01

There is no agreement about the robustness of intuitive representations of the circulatory system and their susceptibility to change by instruction. In this paper, we analyse to what extent students with varying degrees of biology instruction and different ages (High School Health Science and Social Science students and first and final year…

Modeling and control of a brushless DC axial flow ventricular assist device.

PubMed

Giridharan, Guruprasad A; Skliar, Mikhail; Olsen, Donald B; Pantalos, George M

2002-01-01

This article presents an integrated model of the human circulatory system that incorporates circulatory support by a brushless DC axial flow ventricular assist device (VAD), and a feedback VAD controller designed to maintain physiologically sufficient perfusion. The developed integrated model combines a network type model of the circulatory system with a nonlinear dynamic model of the brushless DC pump We show that maintaining a reference differential pressure between the left ventricle and aorta leads to adequate perfusion for different pathologic cases, ranging from normal heart to left heart asystole, and widely varying physical activity scenarios from rest to exercise.

Blood circulation in the ascidian tunicate Corella inflata (Corellidae)

PubMed Central

2016-01-01

The body of the ascidian tunicate Corella inflata is relatively transparent. Thus, the circulatory system can be visualized by injecting high molecular weight fluorescein labeled dextran into the heart or the large vessels at the ends of the heart without surgery to remove the body wall. In addition, after staining with neutral red, the movement of blood cells can be easily followed to further characterize the circulatory system. The heart is two gently curved concentric tubes extending across the width of the animal. The inner myocardial tube has a partial constriction approximately in the middle. As in other tunicates, the heart is peristaltic and periodically reverses direction. During the branchial phase blood leaves the anterior end of the heart by two asymmetric vessels that connect to the two sides of the branchial basket. Blood then flows in both transverse directions through a complex system of ducts in the basket into large ventral and dorsal vessels which carry blood back to the visceral organs in the posterior of the animal. During the visceral phase blood leaves the posterior end of the heart in two vessels that repeatedly bifurcate and fan into the stomach and gonads. Blood velocity, determined by following individual cells in video frames, is high and pulsatory near the heart. A double peak in velocity at the maximum may be due to the constriction in the middle of the heart tube. Blood velocity progressively decreases with distance from the heart. In peripheral regions with vessels of small diameter blood cells frequently collide with vessel walls and cell motion is erratic. The estimated volume of blood flow during each directional phase is greater than the total volume of the animal. Circulating blood cells are confined to vessels or ducts in the visible parts of the animal and retention of high molecular weight dextran in the vessels is comparable to that seen in vertebrates. These are characteristics of a closed circulatory system. PMID:27994977

Countercurrent heat exchange and thermoregulation during blood-feeding in kissing bugs

PubMed Central

Lahondère, Chloé; Insausti, Teresita C; Belev, George; Pereira, Marcos H

2017-01-01

Blood-sucking insects experience thermal stress at each feeding event on endothermic vertebrates. We used thermography to examine how kissing-bugs Rhodnius prolixus actively protect themselves from overheating. During feeding, these bugs sequester and dissipate the excess heat in their heads while maintaining an abdominal temperature close to ambient. We employed a functional-morphological approach, combining histology, µCT and X-ray-synchrotron imaging to shed light on the way these insects manage the flow of heat across their bodies. The close alignment of the circulatory and ingestion systems, as well as other morphological characteristics, support the existence of a countercurrent heat exchanger in the head of R. prolixus, which decreases the temperature of the ingested blood before it reaches the abdomen. This kind of system has never been described before in the head of an insect. For the first time, we show that countercurrent heat exchange is associated to thermoregulation during blood-feeding. PMID:29157359

From Head to Toe: Respiratory, Circulatory, and Skeletal Systems. Book 3.

ERIC Educational Resources Information Center

Wiebe, Arthur, Ed.; And Others

Designed to supplement curricular programs dealing with the human body, this booklet offers an activity-based, student-oriented approach for middle school teachers and students. Twelve activities focus on principles and skills related to the respiratory, circulatory, and skeletal systems. Each activity consists of student sheets and a teacher's…

Description, validation, and modification of the Guyton model for space-flight applications. Part A. Guyton model of circulatory, fluid and electrolyte control. Part B. Modification of the Guyton model for circulatory, fluid and electrolyte control

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1985-01-01

The mathematical model that has been a cornerstone for the systems analysis of space-flight physiological studies is the Guyton model describing circulatory, fluid and electrolyte regulation. The model and the modifications that are made to permit simulation and analysis of the stress of weightlessness are described.

Circulatory Insufficiency and Hypotension Related to the Ductus Arteriosus in Neonates

PubMed Central

Rios, Danielle R.; Bhattacharya, Soume; Levy, Philip T.; McNamara, Patrick J.

2018-01-01

The biological role of the ductus arteriosus (DA) in neonates varies from an innocent bystander role during normal postnatal transition, to a supportive role when there is compromise to either systemic or pulmonary blood flow, to a pathological state in the presence of hemodynamically significant systemic to pulmonary shunts, as occurs in low birth weight infants. Among a wide array of clinical manifestations arising due to the ductal entity, systemic circulatory insufficiency and hypotension are of significant concern as they are particularly challenging to manage. An understanding of the physiologic interplay between the DA and the circulatory system is the key to developing appropriate targeted therapeutic strategies. In this review, we discuss the relationship of systemic hypotension to the DA, emphasizing the importance of critical thinking and a precise individual approach to intensive care support. We particularly focus on the variable states of hypotension arising directly due to a hemodynamically significant DA or seen in the period following successful surgical ligation. In addition, we explore the mechanistic contributions of the ductus to circulatory insufficiency that may manifest during the transitional period, states of maladapted transition (such as acute pulmonary hypertension of the newborn), and congenital heart disease (both ductal dependent and non-ductal dependent lesions). Understanding the dynamic modulator role of the ductus according to the ambient physiology enables a more precise approach to management. We review the pathophysiology, clinical manifestations, diagnosis, monitoring, and therapeutic intervention for the spectrum of DA-related circulatory compromise. PMID:29600242

Is our heart a well-designed pump? The heart along animal evolution.

PubMed

Bettex, Dominique A; Prêtre, René; Chassot, Pierre-Guy

2014-09-07

A carrier system for gases and nutrients became mandatory when primitive animals grew larger and developed different organs. The first circulatory systems are peristaltic tubes pushing slowly the haemolymph into an open vascular tree without capillaries (worms). Arthropods developed contractile bulges on the abdominal aorta assisted by accessory hearts for wings or legs and by abdominal respiratory motions. Two-chamber heart (atrium and ventricle) appeared among mollusks. Vertebrates have a multi-chamber heart and a closed circulation with capillaries. Their heart has two chambers in fishes, three chambers (two atria and one ventricle) in amphibians and reptiles, and four chambers in birds and mammals. The ventricle of reptiles is partially divided in two cavities by an interventricular septum, leaving only a communication of variable size leading to a variable shunt. Blood pressure increases progressively from 15 mmHg (worms) to 170/70 mmHg (birds) according to the increase in metabolic rate. When systemic pressure exceeds 50 mmHg, a lower pressure system appears for the circulation through gills or lungs in order to improve gas exchange. A four-chamber heart allows a complete separation of systemic and pulmonary circuits. This review describes the circulatory pumping systems used in the different classes of animals, their advantages and failures, and the way they have been modified with evolution. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Students' Visualization of Diagrams Representing the Human Circulatory System: The use of spatial isomorphism and representational conventions

NASA Astrophysics Data System (ADS)

Cheng, Maurice M. W.; Gilbert, John K.

2015-01-01

This study investigated students' interpretation of diagrams representing the human circulatory system. We conducted an interview study with three students aged 14-15 (Year 10) who were studying biology in a Hong Kong school. During the interviews, students were asked to interpret diagrams and relationships between diagrams that represented aspects of the circulatory system. All diagrams used in the interviews had been used by their teacher when teaching the topic. Students' interpretations were expressed by their verbal response and their drawing. Dual coding theory was used to interpret students' responses. There was evidence that one student relied on verbal recall as a strategy in interpreting diagrams. It was found that students might have relied unduly on similarities in spatial features, rather than on deeper meanings represented by conventions, of diagrams when they associated diagrams that represented different aspects of the circulatory system. A pattern of students' understanding of structure-behaviour-function relationship of the biological system was observed. This study suggests the importance of a consistent diagrammatic and verbal representation in communicating scientific ideas. Implications for teaching practice that facilitates learning with diagrams and address students' undue focus on spatial features of diagrams are discussed.

Students' Visualization of Diagrams Representing the Human Circulatory System: The Use of Spatial Isomorphism and Representational Conventions

ERIC Educational Resources Information Center

Cheng, Maurice M. W.; Gilbert, John K.

2015-01-01

This study investigated students' interpretation of diagrams representing the human circulatory system. We conducted an interview study with three students aged 14-15 (Year 10) who were studying biology in a Hong Kong school. During the interviews, students were asked to interpret diagrams and relationships between diagrams that represented…

Relations of Cognitive and Motivational Variables with Students' Human Circulatory System Achievement in Traditional and Learning Cycle Classrooms

ERIC Educational Resources Information Center

Sadi, Özlem; Çakiroglu, Jale

2014-01-01

This study is aimed at investigating the relationships among students' relevant prior knowledge, meaningful learning orientation, reasoning ability, self-efficacy, locus of control, attitudes toward biology and achievement with the human circulatory system (HCS) using the learning cycle (LC) and the traditional classroom setting. The study was…

Bilingual Skills Training Program. Barbering/Cosmetology. Module 10.0: Circulatory System.

ERIC Educational Resources Information Center

Northern New Mexico Community Coll., El Rito.

This module on the circulatory or vascular system is the tenth of ten (CE 028 308-318) in the barbering/cosmetology course of a bilingual skills training program. (A Vocabulary Development Workbook for modules 6-10 is available as CE 028 313.) The course is designed to furnish theoretical and laboratory experience. Module objectives are for…

[Caffeine and adaptive changes in the circulatory system during pregnancy].

PubMed

Cendrowska-Pinkosz, Monika; Dworzański, Wojciech; Krauze, Magdalena; Burdan, Franciszek

2017-01-23

Adaptive physiological changes that occur in pregnant women can fluctuate with the intake of substances with proven, adverse biological effect on the body. Due to the fact that caffeine is one of the most chronically used xenobiotics, the impact of consuming caffeine on adaptive processes in the circulatory system of a pregnant women required a research. Many researchers emphasise its negative effect on the circulatory system of the mother and her offspring. However, in spite of years of observation, there is no clear answer to what extent dose or in what period of time the caffeine modulates the adaptive processes during pregnancy. Because of the potential risk the supply of caffeine during pregnancy should be subjected to considerable restrictions.

Mass Transport: Circulatory System with Emphasis on Nonendothermic Species.

PubMed

Crossley, Dane A; Burggren, Warren W; Reiber, Carl L; Altimiras, Jordi; Rodnick, Kenneth J

2016-12-06

Mass transport can be generally defined as movement of material matter. The circulatory system then is a biological example given its role in the movement in transporting gases, nutrients, wastes, and chemical signals. Comparative physiology has a long history of providing new insights and advancing our understanding of circulatory mass transport across a wide array of circulatory systems. Here we focus on circulatory function of nonmodel species. Invertebrates possess diverse convection systems; that at the most complex generate pressures and perform at a level comparable to vertebrates. Many invertebrates actively modulate cardiovascular function using neuronal, neurohormonal, and skeletal muscle activity. In vertebrates, our understanding of cardiac morphology, cardiomyocyte function, and contractile protein regulation by Ca2+ highlights a high degree of conservation, but differences between species exist and are coupled to variable environments and body temperatures. Key regulators of vertebrate cardiac function and systemic blood pressure include the autonomic nervous system, hormones, and ventricular filling. Further chemical factors regulating cardiovascular function include adenosine, natriuretic peptides, arginine vasotocin, endothelin 1, bradykinin, histamine, nitric oxide, and hydrogen sulfide, to name but a few. Diverse vascular morphologies and the regulation of blood flow in the coronary and cerebral circulations are also apparent in nonmammalian species. Dynamic adjustments of cardiovascular function are associated with exercise on land, flying at high altitude, prolonged dives by marine mammals, and unique morphology, such as the giraffe. Future studies should address limits of gas exchange and convective transport, the evolution of high arterial pressure across diverse taxa, and the importance of the cardiovascular system adaptations to extreme environments. © 2017 American Physiological Society. Compr Physiol 7:17-66, 2017. Copyright © 2017 John Wiley & Sons, Inc.

Integrated Immune and Cardiovascular Function in Pancrustacea: Lessons from the Insects.

PubMed

Hillyer, Julián F

2015-11-01

When pathogens invade the insect hemocoel (body cavity) they immediately confront two major forces: immune-responses and circulatory currents. The immune response is mediated by circulating and sessile hemocytes, the fat body, the midgut, and the salivary glands. These tissues drive cellular and humoral immune processes that kill pathogens via phagocytosis, melanization, lysis, encapsulation, and nodulation. Moreover, immune-responses take place within a three-dimensional and dynamic space that is governed by the forces of the circulatory system. The circulation of hemolymph (insect blood) is primarily controlled by the wave-like contraction of a dorsal vessel, which is a muscular tube that extends the length of the insect and is divided into a thoracic aorta and an abdominal heart. Distributed along the heart are valves, called ostia, that allow hemolymph to enter the vessel. Once inside the heart, hemolymph is sequentially propelled to the anterior and to the posterior of the body. During an infection, circulatory currents sweep small pathogens to all regions of the body. As they circulate, pathogens encounter immune factors of the insect that range from soluble cytotoxic peptides to phagocytic hemocytes. A prominent location for these encounters is the surface of the heart. Specifically, periostial hemocytes aggregate in the extracardiac regions that flank the heart's ostia (the periostial regions) and phagocytoze pathogens in areas of high flow of hemolymph. This review summarizes the biology of the immune and circulatory systems of insects, including how these two systems have co-adapted to fight infection. This review also compares the immune and circulatory systems of insects to that of crustaceans, and details how attachment of hemocytes to cardiac tissues and the biology of the lymphoid organ demonstrate that dynamic interactions between the immune and circulatory systems also occur in lineages of crustaceans. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Viscoelasticity of blood and viscoelastic blood analogues for use in polydymethylsiloxane in vitro models of the circulatory system

PubMed Central

Campo-Deaño, Laura; Dullens, Roel P. A.; Aarts, Dirk G. A. L.; Pinho, Fernando T.; Oliveira, Mónica S. N.

2013-01-01

The non-Newtonian properties of blood are of great importance since they are closely related with incident cardiovascular diseases. A good understanding of the hemodynamics through the main vessels of the human circulatory system is thus fundamental in the detection and especially in the treatment of these diseases. Very often such studies take place in vitro for convenience and better flow control and these generally require blood analogue solutions that not only adequately mimic the viscoelastic properties of blood but also minimize undesirable optical distortions arising from vessel curvature that could interfere in flow visualizations or particle image velocimetry measurements. In this work, we present the viscoelastic moduli of whole human blood obtained by means of passive microrheology experiments. These results and existing shear and extensional rheological data for whole human blood in the literature enabled us to develop solutions with rheological behavior analogous to real whole blood and with a refractive index suited for PDMS (polydymethylsiloxane) micro- and milli-channels. In addition, these blood analogues can be modified in order to obtain a larger range of refractive indices from 1.38 to 1.43 to match the refractive index of several materials other than PDMS. PMID:24404022

Development of a hybrid (numerical-hydraulic) circulatory model: prototype testing and its response to IABP assistance.

PubMed

Ferrari, G; Kozarski, M; De Lazzari, C; Górczyńska, K; Tosti, G; Darowski, M

2005-07-01

Merging numerical and physical models of the circulation makes it possible to develop a new class of circulatory models defined as hybrid. This solution reduces the costs, enhances the flexibility and opens the way to many applications ranging from research to education and heart assist devices testing. In the prototype described in this paper, a hydraulic model of systemic arterial tree is connected to a lumped parameters numerical model including pulmonary circulation and the remaining parts of systemic circulation. The hydraulic model consists of a characteristic resistance, of a silicon rubber tube to allow the insertion of an Intra-Aortic Balloon Pump (IABP) and of a lumped parameters compliance. Two electro-hydraulic interfaces, realized by means of gear pumps driven by DC motors, connect the numerical section with both terminals of the hydraulic section. The lumped parameters numerical model and the control system (including analog to digital and digital to analog converters)are developed in LabVIEW environment. The behavior of the model is analyzed by means of the ventricular pressure-volume loops and the time courses of arterial and ventricular pressures and flows in different circulatory conditions. A simulated pathological condition was set to test the IABP and verify the response of the system to this type of mechanical circulatory assistance. The results show that the model can represent hemodynamic relationships in different ventricular and circulatory conditions and is able to react to the IABP assistance.

A pacemaker powered by an implantable biofuel cell operating under conditions mimicking the human blood circulatory system--battery not included.

PubMed

Southcott, Mark; MacVittie, Kevin; Halámek, Jan; Halámková, Lenka; Jemison, William D; Lobel, Robert; Katz, Evgeny

2013-05-07

Biocatalytic electrodes made of buckypaper were modified with PQQ-dependent glucose dehydrogenase on the anode and with laccase on the cathode and were assembled in a flow biofuel cell filled with serum solution mimicking the human blood circulatory system. The biofuel cell generated an open circuitry voltage, Voc, of ca. 470 mV and a short circuitry current, Isc, of ca. 5 mA (a current density of 0.83 mA cm(-2)). The power generated by the implantable biofuel cell was used to activate a pacemaker connected to the cell via a charge pump and a DC-DC converter interface circuit to adjust the voltage produced by the biofuel cell to the value required by the pacemaker. The voltage-current dependencies were analyzed for the biofuel cell connected to an Ohmic load and to the electronic loads composed of the interface circuit, or the power converter, and the pacemaker to study their operation. The correct pacemaker operation was confirmed using a medical device - an implantable loop recorder. Sustainable operation of the pacemaker was achieved with the system closely mimicking human physiological conditions using a single biofuel cell. This first demonstration of the pacemaker activated by the physiologically produced electrical energy shows promise for future electronic implantable medical devices powered by electricity harvested from the human body.

Favorable Circulatory System Outcomes as Adjuvant Traditional Chinese Medicine (TCM) Treatment for Cerebrovascular Diseases in Taiwan

PubMed Central

Chiu, Hsienhsueh Elley; Hong, Yu-Chiang; Chang, Ku-Chou; Shih, Chun-Chuan; Hung, Jen-Wen; Liu, Chia-Wei; Tan, Teng-Yeow; Huang, Chih-Cheng

2014-01-01

Abstract Background This study searches the National Health Insurance Research Database (NHIRD) used in a previous project, aiming for reconstructing possible cerebrovascular disease-related groups (DRG),and estimating the costs between cerebrovascular disease and related diseases. Methods and Materials We conducted a nationwide retrospective cohort study in stroke inpatients, we examined the overall costs in 3 municipalities in Taiwan, by evaluating the possible costs of the expecting diagnosis related group (DRG) by using the international classification of diseases version-9 (ICD-9) system, and the overall analysis of the re-admission population that received traditional Chinese medicine (TCM) treatment and those who did not. Results The trend demonstrated that the non-participant costs were consistent with the ICD-9 categories (430 to 437) because similarities existed between years 2006 to 2007. Among the TCM patients, a wide variation and additional costs were found compared to non-TCM patients during these 2 years. The average re-admission duration was significantly shorter for TCM patients, especially those initially diagnosed with ICD 434 during the first admission. In addition, TCM patients demonstrated more severe general symptoms, which incurred high conventional treatment costs, and could result in re-admission for numerous reasons. However, in Disease 7 of ICD-9 category, representing the circulatory system was most prevalent in non-TCM inpatients, which was the leading cause of re-admission. Conclusion We concluded that favorable circulatory system outcomes were in adjuvant TCM treatment inpatients, there were less re-admission for circulatory system events and a two-third reduction of re-admission within ICD-9 code 430 to 437, compared to non-TCM ones. However, there were shorter re-admission duration other than circulatory system events by means of unfavorable baseline condition. PMID:24475108

Evolutionary morphology of the hemolymph vascular system of basal araneomorph spiders (Araneae: Araneomorphae).

PubMed

Huckstorf, Katarina; Michalik, Peter; Ramírez, Martín; Wirkner, Christian S

2015-11-01

The superfamily Austrochiloidea (Austrochilidae and Gradungulidae) take a pivotal position in araneomorph spider phylogeny. In this discussion crevice weaver spiders (Filistatidae) are of equal interest. Especially data from these phylogenetically uncertain yet basal off branching groups can enlighten our understanding on the evolution of organ systems. In the course of a survey on the evolutionary morphology of the circulatory system in spiders we therefore investigated the hemolymph vascular system in two austrochiloid and one filistatid species. Additionally some data on a hypochilid and a gradungulid species are included. Using up-to-date morphological methods, the vascular systems in these spiders are visualized three dimensionally. Ground pattern features of the circulatory systems in austrochiloid spiders are presented and the data discussed along recent lines of phylogenetic hypotheses. Special topics highlighted are the intraspecific variability of the origins of some prosomal arteries and the evolutionary correlation of respiratory and circulatory systems in spiders. Copyright © 2015 Elsevier Ltd. All rights reserved.

European cardiovascular mortality over the last three decades: evaluation of time trends, forecasts for 2016.

PubMed

Gaeta, M; Campanella, F; Gentile, L; Schifino, G M; Capasso, L; Bandera, F; Banfi, G; Arpesella, M; Ricci, C

2017-01-01

The circulatory diseases, in particular ischemic heart diseases and stroke, represent the main causes of death worldwide both in high income and in middle and low income countries. Our aim is to provide a comprehensive report to depict the circulatory disease mortality in Europe over the last 30 years and to address the sources of heterogeneity among different countries. Our study was performed using the WHO statistical information system - mortality database - and was restricted to the 28 countries belonging to the European Union (EU-28). We evaluated gender and age time series of all circulatory disease mortality, ischemic heart diseases, cerebrovascular diseases, pulmonary and other circulatory diseases and than we performed forecast for 2016. Mortality heterogeneity was evaluated by countries using the Cochrane Q statistic and the I-squared index. Between 1985 and 2011 SDR for deaths attributable to all circulatory system diseases decreased from 440.9 to 212.0 x 100,000 in EU-28 and a clear uniform reduction was observed. Heterogeneity among countries was found to be consistent, therefore different analysis were carried out considering geographical area. We forecast a reduction in European cardiovascular mortality. Heterogeneity among countries could only in part be explained by both geographical and health expenditure factors.

Multi-channel medical imaging system

DOEpatents

Frangioni, John V

2013-12-31

A medical imaging system provides simultaneous rendering of visible light and fluorescent images. The system may employ dyes in a small-molecule form that remain in the subject's blood stream for several minutes, allowing real-time imaging of the subject's circulatory system superimposed upon a conventional, visible light image of the subject. The system may provide an excitation light source to excite the fluorescent substance and a visible light source for general illumination within the same optical guide used to capture images. The system may be configured for use in open surgical procedures by providing an operating area that is closed to ambient light. The systems described herein provide two or more diagnostic imaging channels for capture of multiple, concurrent diagnostic images and may be used where a visible light image may be usefully supplemented by two or more images that are independently marked for functional interest.

Multi-channel medical imaging system

DOEpatents

Frangioni, John V.

2016-05-03

A medical imaging system provides simultaneous rendering of visible light and fluorescent images. The system may employ dyes in a small-molecule form that remain in a subject's blood stream for several minutes, allowing real-time imaging of the subject's circulatory system superimposed upon a conventional, visible light image of the subject. The system may provide an excitation light source to excite the fluorescent substance and a visible light source for general illumination within the same optical guide used to capture images. The system may be configured for use in open surgical procedures by providing an operating area that is closed to ambient light. The systems described herein provide two or more diagnostic imaging channels for capture of multiple, concurrent diagnostic images and may be used where a visible light image may be usefully supplemented by two or more images that are independently marked for functional interest.

Effect of 5E Instructional Model in Student Success in Primary School 6th Year Circulatory System Topic

ERIC Educational Resources Information Center

Cardak, Osman; Dikmenli, Musa; Saritas, Ozge

2008-01-01

The aim of this study is to research the effect of the 5E instructional model on primary (sixth grade) student success during the circulatory system unit. This study was conducted with 38 students in two different classes by the same researcher in 2006-2007. One of the classes was assigned as the control group and the other as the experimental…

System identification of closed-loop cardiovascular control: effects of posture and autonomic blockade

NASA Technical Reports Server (NTRS)

Mullen, T. J.; Appel, M. L.; Mukkamala, R.; Mathias, J. M.; Cohen, R. J.

1997-01-01

We applied system identification to the analysis of fluctuations in heart rate (HR), arterial blood pressure (ABP), and instantaneous lung volume (ILV) to characterize quantitatively the physiological mechanisms responsible for the couplings between these variables. We characterized two autonomically mediated coupling mechanisms [the heart rate baroreflex (HR baroreflex) and respiratory sinus arrhythmia (ILV-HR)] and two mechanically mediated coupling mechanisms [the blood pressure wavelet generated with each cardiac contraction (circulatory mechanics) and the direct mechanical effects of respiration on blood pressure (ILV-->ABP)]. We evaluated the method in humans studied in the supine and standing postures under control conditions and under conditions of beta-sympathetic and parasympathetic pharmacological blockades. Combined beta-sympathetic and parasympathetic blockade abolished the autonomically mediated couplings while preserving the mechanically mediated coupling. Selective autonomic blockade and postural changes also altered the couplings in a manner consistent with known physiological mechanisms. System identification is an "inverse-modeling" technique that provides a means for creating a closed-loop model of cardiovascular regulation for an individual subject without altering the underlying physiological control mechanisms.

Superior cerebral protection with profound hypothermia during circulatory arrest.

PubMed

Gillinov, A M; Redmond, J M; Zehr, K J; Troncoso, J C; Arroyo, S; Lesser, R P; Lee, A W; Stuart, R S; Reitz, B A; Baumgartner, W A

1993-06-01

The optimal temperature for cerebral protection during hypothermic circulatory arrest is not known. This study was undertaken to test the hypothesis that deeper levels of cerebral hypothermia (< 10 degrees C) confer better protection against neurologic injury during prolonged hypothermic circulatory arrest ("colder is better"). Twelve male dogs (20 to 25 kg) were placed on closed-chest cardiopulmonary bypass via femoral artery and femoral/external jugular vein. Using surface and core cooling, tympanic membrane temperature was lowered to 18 degrees to 20 degrees C (deep hypothermia, n = 6) or 5 degrees to 7 degrees C (profound hypothermia, n = 6). After 2 hours of hypothermic circulatory arrest, animals were rewarmed to 35 degrees to 37 degrees C on cardiopulmonary bypass. All were mechanically ventilated and monitored in an intensive care unit setting for 20 hours. Neurologic assessment was performed every 12 hours using a species-specific behavior scale that yielded a neurodeficit score ranging from 0% to 100%, where 0 = normal and 100% = brain dead. After 72 hours, animals were sacrificed and examined histologically for neurologic injury. Histologic injury scores were assigned to each animal (range, 0 [normal] to 100 [severe injury]). At the end of the observation period, profoundly hypothermic animals had better neurologic function (neurodeficit score, 5.7% +/- 4.0%) compared with deeply hypothermic animals (neurodeficit score, 41% +/- 9.3%; p < 0.006). Every animal had histologic evidence of neurologic injury, but profoundly hypothermic animals had significantly less injury (histologic injury score, 19.2 +/- 1.2 versus 48.3 +/- 1.5; p < 0.0001).

In vitro comparison of support capabilities of intra-aortic balloon pump and Impella 2.5 left percutaneous.

PubMed

Schampaert, Stéphanie; van't Veer, Marcel; van de Vosse, Frans N; Pijls, Nico H J; de Mol, Bas A; Rutten, Marcel C M

2011-09-01

The Impella 2.5 left percutaneous (LP), a relatively new transvalvular assist device, challenges the position of the intra-aortic balloon pump (IABP), which has a long record in supporting patients after myocardial infarction and cardiac surgery. However, while more costly and more demanding in management, the advantages of the Impella 2.5 LP are yet to be established. The aim of this study was to evaluate the benefits of the 40 cc IABP and the Impella 2.5 LP operating at 47,000 rpm in vitro, and compare their circulatory support capabilities in terms of cardiac output, coronary flow, cardiac stroke work, and arterial blood pressure. Clinical scenarios of cardiogenic preshock and cardiogenic shock (CS), with blood pressure depression, lowered cardiac output, and constant heart rate of 80 bpm, were modeled in a model-controlled mock circulation, featuring a systemic, pulmonary, and coronary vascular bed. The ventricles, represented by servomotor-operated piston pumps, included the Frank-Starling mechanism. The systemic circulation was modeled with a flexible tube having close-to-human aortic dimensions and compliance properties. Proximally, it featured a branch mimicking the brachiocephalic arteries and a physiological correct coronary flow model. The rest of the systemic and pulmonary impedance was modeled by four-element Windkessel models. In this system, the enhancement of coronary flow and blood pressure was tested with both support systems under healthy and pathological conditions. Hemodynamic differences between the IABP and the Impella 2.5 LP were small. In our laboratory model, both systems approximately yielded a 10% cardiac output increase and a 10% coronary flow increase. However, since the Impella 2.5 LP provided significantly better left ventricular unloading, the circulatory support capabilities were slightly in favor of the Impella 2.5 LP. On the other hand, pulsatility was enhanced with the IABP and lowered with the Impella 2.5 LP. The support capabilities of both the IABP and the Impella 2.5 LP strongly depended on the simulated hemodynamic conditions. Maximum hemodynamic benefits were achieved when mechanical circulatory support was applied on a simulated scenario of deep CS. © 2011, Copyright Eindhoven University of Technology (TU/e). Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Design of a hydraulic analog of the circulatory system for evaluating artificial hearts.

PubMed

Donovan, F M

1975-01-01

A major problem in improving artificial heart designs is the absence of methods for accurate in vitro testing of artificial heart systems. A mock circulatory system has been constructed which hydraulically simulates the systemic and pulmonary circulations of the normal human. The device is constructed of 1/2 in. acrylic sheet and has overall dimensions of 24 in. wide, 16 in. tall, and 8 in. deep. The artificial heart to be tested is attached to the front of the device, and pumps fluid from the systemic venous chamber into the pulmonary arterial chamber and from the pulmonary venous chamber into the systemic arterial chamber. Each of the four chambers is hermetically sealed. The compliance of each chamber is determined by the volume of air trapped above the fluid in that chamber. The pulmonary and systemic resistances are set automatically by bellows-operated valves to simulate the barroreceptor response in the systemic arteries and the passive pulmonary resistance response in the pulmonary arteries. Cardiac output is measured by a turbine flowmeter in the systemic circulation. Results using the Kwan-Gett artificial heart show a good comparison between the mock circulatory system response and the calf response.

A computer model of the pediatric circulatory system for testing pediatric assist devices.

PubMed

Giridharan, Guruprasad A; Koenig, Steven C; Mitchell, Michael; Gartner, Mark; Pantalos, George M

2007-01-01

Lumped parameter computer models of the pediatric circulatory systems for 1- and 4-year-olds were developed to predict hemodynamic responses to mechanical circulatory support devices. Model parameters, including resistance, compliance and volume, were adjusted to match hemodynamic pressure and flow waveforms, pressure-volume loops, percent systole, and heart rate of pediatric patients (n = 6) with normal ventricles. Left ventricular failure was modeled by adjusting the time-varying compliance curve of the left heart to produce aortic pressures and cardiac outputs consistent with those observed clinically. Models of pediatric continuous flow (CF) and pulsatile flow (PF) ventricular assist devices (VAD) and intraaortic balloon pump (IABP) were developed and integrated into the heart failure pediatric circulatory system models. Computer simulations were conducted to predict acute hemodynamic responses to PF and CF VAD operating at 50%, 75% and 100% support and 2.5 and 5 ml IABP operating at 1:1 and 1:2 support modes. The computer model of the pediatric circulation matched the human pediatric hemodynamic waveform morphology to within 90% and cardiac function parameters with 95% accuracy. The computer model predicted PF VAD and IABP restore aortic pressure pulsatility and variation in end-systolic and end-diastolic volume, but diminish with increasing CF VAD support.

Adult extracorporeal life support: a failed or forgotten concept?

PubMed

Colafranceschi, Alexandre Siciliano; Monteiro, Andrey José de Oliveira; Canale, Leonardo Secchin; Campos, Luiz Antonio de Almeida; Montera, Marcelo Westerlund; Silva, Paulo Roberto Dutra da; Fernandes, Marcelo Ramalho; Pinto, Alexandre de Araújo; Molas, Stelmar Moura; Mesquita, Evandro Tinoco

2008-07-01

The extracorporeal membrane oxygenation (ECMO) has been used in the neonatal and childhood periods with excellent results. The adult experience has been modest with inferior immediate results. The intermediate survival, however, has been promising. We have been using the extracorporeal membrane oxygenation for temporary mechanical circulatory support of adults that present with acute refractory cardiogenic shock in our institution. There is no other published experience of the use of this system in this scenario in Brazil. To describe our experience with the use of the extracorporeal membrane oxygenation for circulatory support in adults. Retrospective analysis of the medical files of patients submitted to the implant of extracorporeal membrane oxygenation system for circulatory assistance in acute and refractory cardiogenic shock. Eleven patients (63,5 yo; 45,5% male) were considered for analysis from 2005 to 2007. Median support time was 77 hours (10-240 h) and 5 patients have survived 30 days (45,5%). Two patients were subsequently submitted to prolonged paracorporeal circulatory assistance. Mortality on ECMO (6 patients) was due to multiple organ failure (66,6%) and refractory bleeding (33,4%). ECMO system is an option to be used in acute refractory cardiogenic shock as a bridge to recovery or selecting patients that might benefit from prolonged paracorporeal assist devices (bridge to bridge).

Devices as destination therapy.

PubMed

Kukuy, Eugene L; Oz, Mehmet C; Rose, Eric A; Naka, Yoshifumi

2003-02-01

The use of circulatory support as destination therapy has been a goal for the treatment of endstage heart failure for several decades. Current investigations are evaluating several circulatory pumps with that particular objective. With continued modification of design, the current and future pumps will become more reliable and provide improved quality of life to patients in need of mechanical circulatory assistance. The new pumps on the horizon specifically address reliability, size, and cost, and are based on the centrifugal system. These devices use the Maglev (Magnetic Levitation) concept that allows for frictionless pumping, low thrombogenicity, minimal noise, and increased durability. Further research with this goal in mind and support from the federal government will be the key to the future use of circulatory assistance as destination therapy for heart failure patients. In addition, the cost-effectiveness of these devices will need to be maintained as the technology improves, as in any new technology that confronts a more intuitive option like the native heart.

Evaluation of exercise-respiratory system modifications and integration schemes for physiological systems

NASA Technical Reports Server (NTRS)

Gallagher, R. R.

1974-01-01

Exercise subroutine modifications are implemented in an exercise-respiratory system model yielding improvement of system response to exercise forcings. A more physiologically desirable respiratory ventilation rate in addition to an improved regulation of arterial gas tensions and cerebral blood flow is observed. A respiratory frequency expression is proposed which would be appropriate as an interfacing element of the respiratory-pulsatile cardiovascular system. Presentation of a circulatory-respiratory system integration scheme along with its computer program listing is given. The integrated system responds to exercise stimulation for both nonstressed and stressed physiological states. Other integration possibilities are discussed with respect to the respiratory, pulsatile cardiovascular, thermoregulatory, and the long-term circulatory systems.

Low-frequency dynamics of autonomic regulation of circulatory system in healthy subjects

NASA Astrophysics Data System (ADS)

Skazkina, V. V.; Borovkova, E. I.; Galushko, T. A.; Khorev, V. S.; Kiselev, A. R.

2018-04-01

The paper is devoted to the analysis of dynamic of interactions between signals of autonomic circulatory regulation. We investigated two-hour experimental records of 30 healthy people. Phase synchronization was studied using the signals of the electrocardiogram and the photoplethysmogram of vessels. We found the presence of long synchronous intervals in some subjects. For analysis of the dynamic we calculated autocorrelation functions. The analysis made it possible to reveal indirect signs of the influence of the humoral regulation system.

Blood circulatory system for noninvasive diagnostics

NASA Astrophysics Data System (ADS)

Fricke, D.; Kraitl, J.; Ewald, H.

2013-02-01

Based on the human circulatory system, an artificial blood circulatory system was developed to allow the controlled variation of the following blood parameters: total hemoglobin concentration (ctHb), oxyhemoglobin (O2Hb) methemoglobin (MetHb) and carboxyhemoglobin (COHb). The optical properties of the blood were observed by online spectrometer measurements. The purpose of this was to observe and quantify the absorption, transmission and scattering properties of human whole blood in the wavelength range of 400 to 1700 nm. All the non-invasive measurements of the whole blood transmission-spectra were compared with sample results obtained by a Blood Gas Analyzer (BGA) to validate the results. For all measurements, donor erythrocyte concentrates were used. The concentration of hemoglobin was changed by adding fixed amounts of blood plasma to the erythrocyte concentrate. Oxygen saturation and COHb were adjusted by a continuous flow of N2, N2-CO and compressed air through a hollow fibre membrane oxygenator. Different methemoglobin concentrations were adjusted by using natrium nitrite. The blood temperature was kept constant at 37 °C via a tube heating mechanism, with a separate circulation of water passing through the membrane Oxygenator. The Temperature and pressure of the system were automatically controlled and monitored. The model was also used to test new non-invasive measurement systems, and for this reason special cuvettes were designed to imitate human tissue and generate plethysmographical signals. In the future, the blood circulatory system has the potential to be used for testing, validating and also to calibrate newly developed optical prototype devices. It can also be used to further investigate blood components of interest.

Head capsule, chephalic central nervous system and head circulatory system of an aberrant orthopteran, Prosarthria teretrirostris (Caelifera, Hexapoda).

PubMed

Baum, Eileen; Hertel, Wieland; Beutel, Rolf Georg

2007-01-01

The head capsule, the circulatory system and the central nervous system of the head of Prosarthria teretrirostris (Proscopiidae) is described in detail, with special consideration of modifications resulting from the aberrant head shape. The transformations of the head are completely different from those found in phasmatodeans, which are also characterised by twig mimesis. The circulatory system is distinctly modified. A hitherto undescribed additional structure in the posterior head region very likely functions as a pulsatile organ. The cephalic central nervous system is strongly elongated, with changes in the position of the suboesophageal ganglion, the corpora cardiaca and the course of the nervus mandibularis. Three-dimensional reconstructions of these two organ systems in combination with the pharynx were made using Alias Maya 6.0 software. Comparisons with other representatives of Caelifera suggest a clade comprising Proscopiidae and Morabinae. The presence of a transverse muscle connecting the antennal ampullae in Prosarthria shows that this structure likely belongs to the groundplan of Orthoptera, even though it is missing in different representatives of this group. The transverse ampullary muscle is a potential synapomorphy of Orthoptera, Phasmatodea and Dictyoptera.

Medical imaging systems

DOEpatents

Frangioni, John V [Wayland, MA

2012-07-24

A medical imaging system provides simultaneous rendering of visible light and fluorescent images. The system may employ dyes in a small-molecule form that remains in a subject's blood stream for several minutes, allowing real-time imaging of the subject's circulatory system superimposed upon a conventional, visible light image of the subject. The system may also employ dyes or other fluorescent substances associated with antibodies, antibody fragments, or ligands that accumulate within a region of diagnostic significance. In one embodiment, the system provides an excitation light source to excite the fluorescent substance and a visible light source for general illumination within the same optical guide that is used to capture images. In another embodiment, the system is configured for use in open surgical procedures by providing an operating area that is closed to ambient light. More broadly, the systems described herein may be used in imaging applications where a visible light image may be usefully supplemented by an image formed from fluorescent emissions from a fluorescent substance that marks areas of functional interest.

Central circulatory hemodynamics as a function of gravitational stress

NASA Technical Reports Server (NTRS)

Latham, Rick D.; White, C. D.; Fanton, J. W.; Owens, R. W.; Barber, J. F.; Lewkowski, B. E.; Goff, O. T.

1991-01-01

This study focuses on an evaluation of the central hemodynamics in a nonhuman primate model to variations in gravitational states. The baboon, phylogenectically close to man, was chosen as the human surrogate. The study environments selected are head-down and head-up tilt in the physiology laboratory, centrifugation to test hypergravic stress, and parabolic flights to test transient acute responses to microgravity.

Teaching Integrative Physiology Using the Quantitative Circulatory Physiology Model and Case Discussion Method: Evaluation of the Learning Experience

ERIC Educational Resources Information Center

Rodriguez-Barbero, A.; Lopez-Novoa, J. M.

2008-01-01

One of the problems that we have found when teaching human physiology in a Spanish medical school is that the degree of understanding by the students of the integration between organs and systems is rather poor. We attempted to remedy this problem by using a case discussion method together with the Quantitative Circulatory Physiology (QCP)…

Neighbouring green space and mortality in community-dwelling elderly Hong Kong Chinese: a cohort study.

PubMed

Wang, Dan; Lau, Kevin Ka-Lun; Yu, Ruby; Wong, Samuel Y S; Kwok, Timothy T Y; Woo, Jean

2017-08-01

Green space has been shown to be beneficial for human wellness through multiple pathways. This study aimed to explore the contributions of neighbouring green space to cause-specific mortality. Data from 3544 Chinese men and women (aged ≥65 years at baseline) in a community-based cohort study were analysed. Outcome measures, identified from the death registry, were death from all-cause, respiratory system disease, circulatory system disease. The quantity of green space (%) within a 300 m radius buffer was calculated for each subject from a map created based on the Normalised Difference Vegetation Index. Cox proportional hazard models adjusted for demographics, socioeconomics, lifestyle, health conditions and housing type were used to estimate the HRs and 95% CIs. During a mean of 10.3 years of follow-up, 795 deaths were identified. Our findings showed that a 10% increase in coverage of green space was significantly associated with a reduction in all-cause mortality (HR 0.963, 95% CI 0.930 to 0.998), circulatory system-caused mortality (HR 0.887, 95% CI 0.817 to 0.963) and stroke-caused mortality (HR 0.661, 95% CI 0.524 to 0.835), independent of age, sex, marital status, years lived in Hong Kong, education level, socioeconomic ladder, smoking, alcohol intake, diet quality, self-rated health and housing type. The inverse associations between coverage of green space with all-cause mortality (HR 0.964, 95% CI 0.931 to 0.999) and circulatory system disease-caused mortality (HR 0.888, 95% CI 0.817 to 0.964) were attenuated when the models were further adjusted for physical activity and cognitive function. The effects of green space on all-cause and circulatory system-caused mortality tended to be stronger in females than in males. Higher coverage of green space was associated with reduced risks of all-cause mortality, circulatory system-caused mortality and stroke-caused mortality in Chinese older people living in a highly urbanised city. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Neighbouring green space and mortality in community-dwelling elderly Hong Kong Chinese: a cohort study

PubMed Central

Wang, Dan; Lau, Kevin Ka-Lun; Yu, Ruby; Wong, Samuel Y S; Kwok, Timothy T Y; Woo, Jean

2017-01-01

Objective Green space has been shown to be beneficial for human wellness through multiple pathways. This study aimed to explore the contributions of neighbouring green space to cause-specific mortality. Methods Data from 3544 Chinese men and women (aged ≥65 years at baseline) in a community-based cohort study were analysed. Outcome measures, identified from the death registry, were death from all-cause, respiratory system disease, circulatory system disease. The quantity of green space (%) within a 300 m radius buffer was calculated for each subject from a map created based on the Normalised Difference Vegetation Index. Cox proportional hazard models adjusted for demographics, socioeconomics, lifestyle, health conditions and housing type were used to estimate the HRs and 95% CIs. Results During a mean of 10.3 years of follow-up, 795 deaths were identified. Our findings showed that a 10% increase in coverage of green space was significantly associated with a reduction in all-cause mortality (HR 0.963, 95% CI 0.930 to 0.998), circulatory system-caused mortality (HR 0.887, 95% CI 0.817 to 0.963) and stroke-caused mortality (HR 0.661, 95% CI 0.524 to 0.835), independent of age, sex, marital status, years lived in Hong Kong, education level, socioeconomic ladder, smoking, alcohol intake, diet quality, self-rated health and housing type. The inverse associations between coverage of green space with all-cause mortality (HR 0.964, 95% CI 0.931 to 0.999) and circulatory system disease-caused mortality (HR 0.888, 95% CI 0.817 to 0.964) were attenuated when the models were further adjusted for physical activity and cognitive function. The effects of green space on all-cause and circulatory system-caused mortality tended to be stronger in females than in males. Conclusion Higher coverage of green space was associated with reduced risks of all-cause mortality, circulatory system-caused mortality and stroke-caused mortality in Chinese older people living in a highly urbanised city. PMID:28765127

Developing seventh grade students' systems thinking skills in the context of the human circulatory system.

PubMed

Raved, Lena; Yarden, Anat

2014-01-01

Developing systems thinking skills in school can provide useful tools to deal with a vast amount of medical and health information that may help learners in decision making in their future lives as citizen. Thus, there is a need to develop effective tools that will allow learners to analyze biological systems and organize their knowledge. Here, we examine junior high school students' systems thinking skills in the context of the human circulatory system. A model was formulated for developing teaching and learning materials and for characterizing students' systems thinking skills. Specifically, we asked whether seventh grade students, who studied about the human circulatory system, acquired systems thinking skills, and what are the characteristics of those skills? Concept maps were used to characterize students' systems thinking components and examine possible changes in the students' knowledge structure. These maps were composed by the students before and following the learning process. The study findings indicate a significant improvement in the students' ability to recognize the system components and the processes that occur within the system, as well as the relationships between different levels of organization of the system, following the learning process. Thus, following learning students were able to organize the systems' components and its processes within a framework of relationships, namely the students' systems thinking skills were improved in the course of learning using the teaching and learning materials.

Application of a PExSim for modeling a POLVAD artificial heart and the human circulatory system with left ventricle assistance

NASA Astrophysics Data System (ADS)

Siewnicka, Alicja; Fajdek, Bartlomiej; Janiszowski, Krzysztof

2010-01-01

This paper presents a model of the human circulatory system with the possible addition of a parallel assist device, which was developed for the purpose of artificial heart monitoring. Information about an identification experiment of an extracorporeal ventricle assist device POLVAD is included. The modelling methods applied and the corresponding functional blocks in a PExSim package are presented. The results of the simulation for physiological conditions, left ventricle failure and pathological conditions with parallel assistance are included.

[Prevention of circulatory system diseases in underground mining workers].

PubMed

Vlasova, E M; Alexeyev, M B; Shliapnikov, D M; Nosov, A E; Barannikov, V G

2015-01-01

The article covers results of preventive measures in workers engaged into underground mining. Those measures are aimed to prevent occupationally mediated health disorders resulting in circulatory diseases. The prophylaxis was proven effective on premorbid condition--that was demonstrated in reliable decrease of cause-effect relationship intensity for health disorders in workers subjected to prophylactic measures. Transitory disablement morbidity due to cicrulatory system diseases decreased. Situational modelling of risk changes for the studied group demonstrated changes of diseases risk under medical prophylactic measures. After the prophylaxis, the risk demonstrated 3.1 times decrease.

Pediatric Donation After Circulatory Determination of Death: A Scoping Review.

PubMed

Weiss, Matthew J; Hornby, Laura; Witteman, William; Shemie, Sam D

2016-03-01

Although pediatric donation after circulatory determination of death is increasing in frequency, there are no national or international donation after circulatory determination of death guidelines specific to pediatrics. This scoping review was performed to map the pediatric donation after circulatory determination of death literature, identify pediatric donation after circulatory determination of death knowledge gaps, and inform the development of national or regional pediatric donation after circulatory determination of death guidelines. Terms related to pediatric donation after circulatory determination of death were searched in Embase and MEDLINE, as well as the non-MEDLINE sources in PubMed from 1980 to May 2014. Seven thousand five hundred ninety-seven references were discovered and 85 retained for analysis. All references addressing pediatric donation after circulatory determination of death were considered. Exclusion criteria were articles that did not address pediatric patients, animal or laboratory studies, surgical techniques, and local pediatric donation after circulatory determination of death protocols. Narrative reviews and opinion articles were the most frequently discovered reference (25/85) and the few discovered studies were observational or qualitative and almost exclusively retrospective. Retained references were divided into themes and analyzed using qualitative methodology. The main discovered themes were 1) studies estimating the number of potential pediatric donation after circulatory determination of death donors and their impact on donation; 2) ethical issues in pediatric donation after circulatory determination of death; 3) physiology of the dying process after withdrawal of life-sustaining therapy; 4) cardiac pediatric donation after circulatory determination of death; and 5) neonatal pediatric donation after circulatory determination of death. Donor estimates suggest that pediatric donation after circulatory determination of death will remain an event less common than brain death, albeit with the potential to substantially expand the existing organ donation pool. Limited data suggest outcomes comparable with organs donated after neurologic determination of death. Although there is continued debate around ethical aspects of pediatric donation after circulatory determination of death, all pediatric donation after circulatory determination of death publications from professional societies contend that pediatric donation after circulatory determination of death can be practiced ethically. This review provides a comprehensive overview of the published literature related to pediatric donation after circulatory determination of death. In addition to informing the development of pediatric-specific guidelines, this review serves to highlight several important knowledge gaps in this topic.

[THE CHARACTERISTIC OF SOMATOTYPE AND FUNCTIONAL STATE OF CIRCULATORY SYSTEM OF STUDENT YOUTH OF THE NORTHEAST OF RUSSIA].

PubMed

Timofeieva, A V; Klimova, T M; Mikhailova, A E; Zakharova, R N; Vinokurova, S P; Timofeiev, L F

2015-01-01

The article considers results of single-step study in random sampling of female students of the M.K. Ammosov north-east federal university (n=456). The study was carried out to investigate somatotype and functional state of circulatory system. The standard technique was applied to measure height, body mass, chest circumference, level of arterial pressure and rate of heart beats. The type of somatotype was established using Pignet index. The tone of vegetative system was determined using Kérdö index. The adaptation potential of circulatory system was determined using functional changes index. The results of study established that in 61% of examined female students the type of constitution corresponds to normosthenic one. The percentage of persons with asthenic and hypersthenic type of constitution amounted to 27% and 12% correspondingly. The signs of increasing oftone ofsympathetic nervous system are observed in 89% of girls. The functional condition of circulatory system is evaluated as "tension of adaptation mechanisms" that is apparently related to period of adaptation to new conditions. The prolonged preservation of such states results in exhaustion offunctional resources of organism and can promote development of diseases. In conditions of impacting of unfavorable ecological factors the deconditionning disorders can significantly contribute to health disturbances and decreasing of life quality. To preserve youth's health during period of education the comprehensive strategy is to be implemented such components as dynamic monitoring of health, organization of adequate diet, explanation of necessity of observance of sleep and rest pattern, development of conditions for active aerobic physical exertion and activities on correction of risk factors of development of diseases are to be included.

Developing Seventh Grade Students’ Systems Thinking Skills in the Context of the Human Circulatory System

PubMed Central

Raved, Lena; Yarden, Anat

2014-01-01

Developing systems thinking skills in school can provide useful tools to deal with a vast amount of medical and health information that may help learners in decision making in their future lives as citizen. Thus, there is a need to develop effective tools that will allow learners to analyze biological systems and organize their knowledge. Here, we examine junior high school students’ systems thinking skills in the context of the human circulatory system. A model was formulated for developing teaching and learning materials and for characterizing students’ systems thinking skills. Specifically, we asked whether seventh grade students, who studied about the human circulatory system, acquired systems thinking skills, and what are the characteristics of those skills? Concept maps were used to characterize students’ systems thinking components and examine possible changes in the students’ knowledge structure. These maps were composed by the students before and following the learning process. The study findings indicate a significant improvement in the students’ ability to recognize the system components and the processes that occur within the system, as well as the relationships between different levels of organization of the system, following the learning process. Thus, following learning students were able to organize the systems’ components and its processes within a framework of relationships, namely the students’ systems thinking skills were improved in the course of learning using the teaching and learning materials. PMID:25520948

Deep hypothermic circulatory arrest

PubMed Central

Ziganshin, Bulat A.

2013-01-01

Effective cerebral protection remains the principle concern during aortic arch surgery. Hypothermic circulatory arrest (HCA) is entrenched as the primary neuroprotection mechanism since the 70s, as it slows injury-inducing pathways by limiting cerebral metabolism. However, increases in HCA duration has been associated with poorer neurological outcomes, necessitating the adjunctive use of antegrade (ACP) and retrograde cerebral perfusion (RCP). ACP has superseded RCP as the preferred perfusion strategy as it most closely mimic physiological perfusion, although there exists uncertainty regarding several technical details, such as unilateral versus bilateral perfusion, flow rate and temperature, perfusion site, undue trauma to head vessels, and risks of embolization. Nevertheless, we believe that the convenience, simplicity and effectiveness of straight DHCA justifies its use in the majority of elective and emergency cases. The following perspective offers a historical and clinical comparison of the DHCA with other techniques of cerebral protection. PMID:23977599

Microbiota, immunity and the liver.

PubMed

Vaikunthanathan, T; Safinia, N; Lombardi, G; Lechler, R I

2016-03-01

The gut harbors a complex community of over 100 trillion microbial cells known to exist in symbiotic harmony with the host influencing human physiology, metabolism, nutrition and immune function. It is now widely accepted that perturbations of this close partnership results in the pathogenesis of several major diseases with increasing evidence highlighting their role outside of the intestinal tract. The intimate proximity and circulatory loop of the liver and the gut has attracted significant attention regarding the role of the microbiota in the development and progression of liver disease. Here we give an overview of the interaction between the microbiota and the immune system and focus on their convincing role in both the propagation and treatment of liver disease. Copyright © 2016. Published by Elsevier B.V.

In vitro microfluidic circulatory system for circulating cancer cells

PubMed Central

wan, jiandi; Fan, Rong; Emery, Travis; Zhang, Yongguo; Xia, Yuxuan; Sun, Jun; Wan, Jiandi

2016-01-01

Circulating tumor cells (CTCs) experience hemodynamic shear stress in circulation and play critical roles in cancer metastasis. The effect of shear on CTCs, however, remains less studied. Here, we described a protocol to circulate HCT116 human colon cancer cells in a microfluidic circulatory system mimicking physiologically relevant circulating conditions. This protocol represents a useful scaffold to mimic the transportation of CTCs in circulation and thus provides an effective means to study the effect of shear on CTCs. We anticipate that future studies using the developed system will help us to further investigate the regulatory roles of shear in molecular responses of CTCs. PMID:28690779

Life expectancy and death by diseases of the circulatory system in patients with bipolar disorder or schizophrenia in the Nordic countries.

PubMed

Laursen, Thomas Munk; Wahlbeck, Kristian; Hällgren, Jonas; Westman, Jeanette; Ösby, Urban; Alinaghizadeh, Hassan; Gissler, Mika; Nordentoft, Merete

2013-01-01

Excess mortality from diseases and medical conditions (natural death) in persons with psychiatric disorders has been extensively reported. Even in the Nordic countries with well-developed welfare systems, register based studies find evidence of an excess mortality. In recent years, cardiac mortality and death by diseases of the circulatory system has seen a decline in all the Nordic countries, but a recent paper indicates that women and men in Denmark, Finland, and Sweden, who had been hospitalised for a psychotic disorder, had a two to three-fold increased risk of dying from a cardiovascular disease. The aim of this study was to compare the mortality by diseases of the circulatory system among patients with bipolar disorder or schizophrenia in the three Nordic countries Denmark, Sweden, and Finland. Furthermore, the aim was to examine and compare life expectancy among these patients. Cause specific Standardized Mortality Rates (SMRs) were calculated for each specific subgroup of mortality. Life expectancy was calculated using Wiesler's method. The SMR for bipolar disorder for diseases of the circulatory system was approximately 2 in all countries and both sexes. SMR was slightly higher for people with schizophrenia for both genders and in all countries, except for men in Denmark. Overall life expectancy was much lower among persons with bipolar disorder or schizophrenia, with life expectancy being from 11 to 20 years shorter. Our data show that persons in the Nordic countries with schizophrenia or bipolar disorder have a substantially reduced life expectancy. An evaluation of the reasons for these increased mortality rates should be prioritized when planning healthcare in the coming years.

Life Expectancy and Death by Diseases of the Circulatory System in Patients with Bipolar Disorder or Schizophrenia in the Nordic Countries

PubMed Central

Laursen, Thomas Munk; Wahlbeck, Kristian; Hällgren, Jonas; Westman, Jeanette; Ösby, Urban; Alinaghizadeh, Hassan; Gissler, Mika; Nordentoft, Merete

2013-01-01

Objective Excess mortality from diseases and medical conditions (natural death) in persons with psychiatric disorders has been extensively reported. Even in the Nordic countries with well-developed welfare systems, register based studies find evidence of an excess mortality. In recent years, cardiac mortality and death by diseases of the circulatory system has seen a decline in all the Nordic countries, but a recent paper indicates that women and men in Denmark, Finland, and Sweden, who had been hospitalised for a psychotic disorder, had a two to three-fold increased risk of dying from a cardiovascular disease. The aim of this study was to compare the mortality by diseases of the circulatory system among patients with bipolar disorder or schizophrenia in the three Nordic countries Denmark, Sweden, and Finland. Furthermore, the aim was to examine and compare life expectancy among these patients. Cause specific Standardized Mortality Rates (SMRs) were calculated for each specific subgroup of mortality. Life expectancy was calculated using Wiesler’s method. Results The SMR for bipolar disorder for diseases of the circulatory system was approximately 2 in all countries and both sexes. SMR was slightly higher for people with schizophrenia for both genders and in all countries, except for men in Denmark. Overall life expectancy was much lower among persons with bipolar disorder or schizophrenia, with life expectancy being from 11 to 20 years shorter. Conclusion Our data show that persons in the Nordic countries with schizophrenia or bipolar disorder have a substantially reduced life expectancy. An evaluation of the reasons for these increased mortality rates should be prioritized when planning healthcare in the coming years. PMID:23826212

Computational Hemodynamic Simulation of Human Circulatory System under Altered Gravity

NASA Technical Reports Server (NTRS)

Kim. Chang Sung; Kiris, Cetin; Kwak, Dochan

2003-01-01

A computational hemodynamics approach is presented to simulate the blood flow through the human circulatory system under altered gravity conditions. Numerical techniques relevant to hemodynamics issues are introduced to non-Newtonian modeling for flow characteristics governed by red blood cells, distensible wall motion due to the heart pulse, and capillary bed modeling for outflow boundary conditions. Gravitational body force terms are added to the Navier-Stokes equations to study the effects of gravity on internal flows. Six-type gravity benchmark problems are originally presented to provide the fundamental understanding of gravitational effects on the human circulatory system. For code validation, computed results are compared with steady and unsteady experimental data for non-Newtonian flows in a carotid bifurcation model and a curved circular tube, respectively. This computational approach is then applied to the blood circulation in the human brain as a target problem. A three-dimensional, idealized Circle of Willis configuration is developed with minor arteries truncated based on anatomical data. Demonstrated is not only the mechanism of the collateral circulation but also the effects of gravity on the distensible wall motion and resultant flow patterns.

Does the use of thiopental provide added cerebral protection during deep hypothermic circulatory arrest?

PubMed Central

Al-Hashimi, Sara; Zaman, Mahvash; Waterworth, Paul; Bilal, Haris

2013-01-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Does the use of thiopental provide added cerebral protection during deep hypothermic circulatory arrest (DHCA)? Altogether, more than 62 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Four of the seven papers used thiopental alongside other neuroprotective methods and agents. The methods included the use of ice packs to the head and core systemic hypothermia. Agents used alongside thiopental included nicardipine and mannitol. Thiopental was found to have the ability to lower oxygen consumption, where oxygen consumption was measured using the phosphocreatinine and adenosine triphosphate ratio. The neuroprotective effect of thiopental was evaluated by assessing the electrical activity of the brain during circulatory arrest, by which it was shown to be advantageous. However, other trials suggested that adding thiopental during circulatory arrest did not provide any extra protection to the brain. The timing of thiopental administration is of importance in order to gain positive outcomes, as it's ability to lower the cerebral energy state may result in unfavourable results if added before hypothermic circulatory arrest, where this may lead to an ischaemic event. We conclude that the use of thiopental during deep hypothermic circulatory arrest is beneficial, but if administered too early, it may replete the cerebral energy state before arrest and prove to be detrimental. PMID:23644730

Does the use of thiopental provide added cerebral protection during deep hypothermic circulatory arrest?

PubMed

Al-Hashimi, Sara; Zaman, Mahvash; Waterworth, Paul; Bilal, Haris

2013-08-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Does the use of thiopental provide added cerebral protection during deep hypothermic circulatory arrest (DHCA)? Altogether, more than 62 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Four of the seven papers used thiopental alongside other neuroprotective methods and agents. The methods included the use of ice packs to the head and core systemic hypothermia. Agents used alongside thiopental included nicardipine and mannitol. Thiopental was found to have the ability to lower oxygen consumption, where oxygen consumption was measured using the phosphocreatinine and adenosine triphosphate ratio. The neuroprotective effect of thiopental was evaluated by assessing the electrical activity of the brain during circulatory arrest, by which it was shown to be advantageous. However, other trials suggested that adding thiopental during circulatory arrest did not provide any extra protection to the brain. The timing of thiopental administration is of importance in order to gain positive outcomes, as it's ability to lower the cerebral energy state may result in unfavourable results if added before hypothermic circulatory arrest, where this may lead to an ischaemic event. We conclude that the use of thiopental during deep hypothermic circulatory arrest is beneficial, but if administered too early, it may replete the cerebral energy state before arrest and prove to be detrimental.

Childhood Cancer

MedlinePlus

... the circulatory system and the lymphatic system , two systems that are located throughout the body. This makes it hard to treat these cancers by operating on just one area. However, in children with ...

Donation after brain circulation determination of death.

PubMed

Dalle Ave, Anne L; Bernat, James L

2017-02-23

The fundamental determinant of death in donation after circulatory determination of death is the cessation of brain circulation and function. We therefore propose the term donation after brain circulation determination of death [DBCDD]. In DBCDD, death is determined when the cessation of circulatory function is permanent but before it is irreversible, consistent with medical standards of death determination outside the context of organ donation. Safeguards to prevent error include that: 1] the possibility of auto-resuscitation has elapsed; 2] no brain circulation may resume after the determination of death; 3] complete circulatory cessation is verified; and 4] the cessation of brain function is permanent and complete. Death should be determined by the confirmation of the cessation of systemic circulation; the use of brain death tests is invalid and unnecessary. Because this concept differs from current standards, consensus should be sought among stakeholders. The patient or surrogate should provide informed consent for organ donation by understanding the basis of the declaration of death. In cases of circulatory cessation, such as occurs in DBCDD, death can be defined as the permanent cessation of brain functions, determined by the permanent cessation of brain circulation.

[Clinical exercise testing and the Fick equation: strategic thinking for optimizing diagnosis].

PubMed

Perrault, H; Richard, R

2012-04-01

This article examines the expected exercise-induced changes in the components of the oxygen transport system as described by the Fick equation with a view to enable a critical analysis of a standard incremental exercise test to identify normal and abnormal patterns of responses and generate hypotheses as to potential physiological and/or pathophysiological causes. The text reviews basic physiological principals and provides useful reminders of standard equations that serve to integrate circulatory, respiratory and skeletal muscle functions. More specifically, the article provides a conceptual and quantitative framework linking the exercise-induced increase in whole body oxygen uptake to central circulatory and peripheral circulatory factors with the view to establish the normalcy of response. Thus, the article reviews the exercise response to cardiac output determinants and provides qualitative and quantitative perspective bases for making assumptions on the peripheral circulatory factors and oxygen use. Finally, the article demonstrates the usefulness of exercise testing as an effective integrative physiological approach to develop clinical reasoning or verify pathophysiological outcomes. Copyright © 2012 SPLF. Published by Elsevier Masson SAS. All rights reserved.

[The application of the multidimensional statistical methods in the evaluation of the influence of atmospheric pollution on the population's health].

PubMed

Surzhikov, V D; Surzhikov, D V

2014-01-01

The search and measurement of causal relationships between exposure to air pollution and health state of the population is based on the system analysis and risk assessment to improve the quality of research. With this purpose there is applied the modern statistical analysis with the use of criteria of independence, principal component analysis and discriminate function analysis. As a result of analysis out of all atmospheric pollutants there were separated four main components: for diseases of the circulatory system main principal component is implied with concentrations of suspended solids, nitrogen dioxide, carbon monoxide, hydrogen fluoride, for the respiratory diseases the main c principal component is closely associated with suspended solids, sulfur dioxide and nitrogen dioxide, charcoal black. The discriminant function was shown to be used as a measure of the level of air pollution.

Pericyte function in the physiological central nervous system.

PubMed

Muramatsu, Rieko; Yamashita, Toshihide

2014-01-01

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

An exceptionally preserved myodocopid ostracod from the Silurian of Herefordshire, UK

PubMed Central

Siveter, David J.; Briggs, Derek E. G.; Siveter, Derek J.; Sutton, Mark D.

2010-01-01

An exceptionally preserved new ostracod crustacean from the Silurian of Herefordshire, UK, represents only the third fully documented Palaeozoic ostracod with soft-part preservation. Appendages, gills, gut system, lateral compound eyes and even a medial eye with a Bellonci organ are preserved, allowing assignment of the fossil to a new genus and species of cylindroleberidid myodocope (Myodocopida, Cylindroleberididae). The Bellonci organ is recorded for the first time in fossil ostracods. The find also represents a rare occurrence of gills in fossil ostracods and confirms the earliest direct evidence of a respiratory-cum-circulatory system in the group. The species demonstrates remarkably conserved morphology within myodocopes over a period of 425 Myr. Its shell morphology more closely resembles several families of myodocopes other than the Cylindroleberididae, especially the Cypridinidae and Sarsiellidae, thus questioning the utility of the carapace alone in establishing the affinity of fossil ostracods. PMID:20106847

Overview of the 2016 U.S. Food and Drug Administration Circulatory System Devices Advisory Panel Meeting on the Absorb Bioresorbable Vascular Scaffold System.

PubMed

Steinvil, Arie; Rogers, Toby; Torguson, Rebecca; Waksman, Ron

2016-09-12

This study aims to describe the discussions and recommendations made during the U.S. Food and Drug Administration (FDA) Circulatory System Device Panel pre-market approval application for the Absorb Bioresorbable Vascular Scaffold (BVS) System. The Absorb BVS System is a first-of-its-kind fully bioresorbable percutaneous coronary intervention technology. The absorb BVS was studied in the ABSORB III (A Clinical Evaluation of Absorb BVS, the Everolimus Eluting Bioresorbable Vascular Scaffold in the Treatment of Subjects with de Novo Native Coronary Artery Lesions) trial, the pivotal U.S. investigational device exemption trial. Observational report of the FDA Circulatory System Device Panel pre-market approval application meeting held on March 15, 2016. The U.S. FDA Circulatory System Device Panel members reviewed the ABSROB III trial outcomes and additional post hoc analyses presented by the sponsor and the FDA. The ABSORB III trial met the primary endpoint of noninferiority of Absorb BVS compared with the control, XIENCE drug-eluting stent, for target lesion failure at 1 year. Although a higher numerical trend for adverse outcomes was reported for the Absorb BVS, there were no statistical differences between Absorb BVS and XIENCE for any safety or effectiveness components for target lesion failure or for the secondary pre-specified outcomes. Panel members raised concerns with regard to the ABSORB III results and post hoc analyses focusing mainly on the noninferiority design of the trial, the apparent safety issues of the Absorb BVS in small vessels, the mismatch of visually versus intravascular imaging assessed vessel size found in ABSORB III and its implications on the adequate device labeling, the safety of Absorb BVS in specific patient and lesion subsets, and the post-approval commitments of the sponsor. Following panel discussions and the evidence presented, the panel voted for approval of the device. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Physics of the Circulatory System.

ERIC Educational Resources Information Center

Van Heuvelen, Alan

1989-01-01

Discusses some calculations and demonstrations illustrating the role of physics in cardiovascular system. Describes a model for the system, work done by the heart, pressure in blood vessel, and gravitational effects. (YP)

Getting home with artifical heart – what is the everyday life experience of people with mechanical circulatory Support. A qualitative study

PubMed

Braunsdorf, Sandy

2017-07-01

Background: The growing number of mechanical circulatory support systems implanted with successful results in terms of quality of life and physical resilience means that more and more people are being discharged from hospital to live at home with an artificial heart. This puts high requirements on affected persons’ disease and therapy management – a subject which has attracted very little qualitative research to date. Aim: This study therefore sought to shed light on how people with mechanical circulatory support experience their everyday lives. The aim was to document the subjective associations of those affected from an insider perspective. Methods: Following the interpretative phenomenological paradigm, narrative interviews were conducted with two female and eight male participants. For qualitative analysis, a multi-step process guided by the methodology of hermeneutic philosophy was used. Results: The qualitative data analysis revealed five main topic areas. These describe patients’ state of health after implantation and the various adjustments, constraints and pressures necessitated by their illness and therapeutic requirements. On this basis, coping and management strategies are identified. Other significant aspects of patients’ everyday lives are social interaction and environment and health care with an artificial heart. Conclusions: The findings add to our knowledge of the day-to-day lives of people with mechanical circulatory support systems, giving us a better understanding of their specific situation.

Circular pump support of blood circulation in the human body

NASA Astrophysics Data System (ADS)

Medvedev, A. E.; Fomin, V. M.; Prikhodko, Yu. M.; Cherniavskiy, A. M.; Fomichev, V. P.; Fomichev, A. V.; Chekhov, V. P.; Ruzmatov, T. M.

2016-10-01

The need of circulatory support systems in the treatment of chronic heart failure is increasing constantly, as 20% of patients in the waiting list die every year. Despite the great need for mechanical heart support systems, using of available systems is limited by the expensiveness. In addition, there is no one system that is 100% responsible to all medical and technical requirements, and would be completely safe for patient. Therefore, further research in the field of circu-latory support systems, considering health and technical requirements is relevant. One of the new directions in the study are disc pumps of viscous friction for liquid transporting, based on the Tesla pump principle. The operation principle of pumps based on the phenomenon of the boundary layer which is formed on the disk rotating in a fluid. There are experimental studies results of models with different variants of the rotor suspension, the various forms and the number of disks, forms the pump housing. However, none of the above samples was not brought to clinical trials. Furthermore, despite the promise of this model is still used today in some circulatory support systems are no similar type pump. Published data provide a basis for further development and testing of the pump model and allow to hope for leveling a number of significant shortcomings of modern left ventricular bypass systems.

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS): first annual report.

PubMed

de By, Theo M M H; Mohacsi, Paul; Gummert, Jan; Bushnaq, Hasan; Krabatsch, Thomas; Gustafsson, Finn; Leprince, Pascal; Martinelli, Luigi; Meyns, Bart; Morshuis, Michiel; Netuka, Ivan; Potapov, Evgenij; Zittermann, Armin; Delmo Walter, Eva Maria; Hetzer, Roland

2015-05-01

The European Registry for Patients with Mechanical Circulatory Support (EUROMACS) was founded on 10 December 2009 with the initiative of Roland Hetzer (Deutsches Herzzentrum Berlin, Berlin, Germany) and Jan Gummert (Herz- und Diabeteszentrum Nordrhein-Westfalen, Bad Oeynhausen, Germany) with 15 other founding international members. It aims to promote scientific research to improve care of end-stage heart failure patients with ventricular assist device or a total artificial heart as long-term mechanical circulatory support. Likewise, the organization aims to provide and maintain a registry of device implantation data and long-term follow-up of patients with mechanical circulatory support. Hence, EUROMACS affiliated itself with Dendrite Clinical Systems Ltd to offer its members a software tool that allows input and analysis of patient clinical data on a daily basis. EUROMACS facilitates further scientific studies by offering research groups access to any available data wherein patients and centres are anonymized. Furthermore, EUROMACS aims to stimulate cooperation with clinical and research institutions and with peer associations involved to further its aims. EUROMACS is the only European-based Registry for Patients with Mechanical Circulatory Support with rapid increase in institutional and individual membership. Because of the expeditious data input, the European Association for Cardiothoracic Surgeons saw the need to optimize the data availability and the significance of the registry to improve care of patients with mechanical circulatory support and its potential contribution to scientific intents; hence, the beginning of their alliance in 2012. This first annual report is designed to provide an overview of EUROMACS' structure, its activities, a first data collection and an insight to its scientific contributions. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Contemporary Risk Factors and Outcomes of Transfusion-Associated Circulatory Overload.

PubMed

Roubinian, Nareg H; Hendrickson, Jeanne E; Triulzi, Darrell J; Gottschall, Jerome L; Michalkiewicz, Michael; Chowdhury, Dhuly; Kor, Daryl J; Looney, Mark R; Matthay, Michael A; Kleinman, Steven H; Brambilla, Donald; Murphy, Edward L

2018-04-01

Transfusion-associated circulatory overload is characterized by hydrostatic pulmonary edema following blood transfusion. Restrictive transfusion practice may affect the occurrence and severity of transfusion-associated circulatory overload in critically ill patients. We sought to examine contemporary risk factors and outcomes for transfusion-associated circulatory overload. Case-control study. Four tertiary care hospitals. We prospectively enrolled 200 patients with transfusion-associated circulatory overload identified by active surveillance and 405 controls matched by transfusion intensity. None. Among 20,845 transfused patients who received 128,263 blood components from May 2015 until July 2016, transfusion-associated circulatory overload incidence was one case per 100 transfused patients. In addition to cardiovascular comorbidities, multivariable analysis identified the following independent predictors of transfusion-associated circulatory overload: acute kidney injury, emergency surgery, pretransfusion diuretic use, and plasma transfusion-the latter especially in females. Compared with matched controls, transfusion-associated circulatory overload cases were more likely to require mechanical ventilation (71% vs 49%; p < 0.001), experienced longer intensive care and hospital lengths of stay following transfusion, and had higher mortality (21% vs 11%; p = 0.02) even after adjustment for other potentially confounding variables. Despite restrictive transfusion practice, transfusion-associated circulatory overload remains a frequent complication of transfusion and is an independent risk factor for in-hospital morbidity and mortality. In addition to cardiovascular and renal risk factors, plasma transfusion was associated with transfusion-associated circulatory overload after controlling for other covariates. Additional research is needed to examine the benefit of reduced erythrocyte or plasma exposure in patients at high risk for transfusion-associated circulatory overload.

Atmospheric pressure fluctuations in the far infrasound range and emergency transport events coded as circulatory system diseases.

PubMed

Didyk, L A; Gorgo, Yu P; Dirckx, J J J; Bogdanov, V B; Buytaert, J A N; Lysenko, V A; Didyk, N P; Vershygora, A V; Erygina, V T

2008-09-01

This study examines whether a relation exists between rapid atmospheric pressure fluctuations, attributed to the far infrasound frequency range (APF), and a number of emergency transport events coded as circulatory system diseases (EEC). Over an entire year, the average integral amplitudes of APF in the range of periods from 3 s to 120 s over each hour (HA) were measured. Daily dynamics of HA averaged over the year revealed a wave shape with smooth increase from night to day followed by decrease from day to night. The total daily number of EEC within the city of Kiev, Ukraine, was related to the daily mean of HA (DHA) and to the ratio of HA averaged over the day time to HA averaged over the night time (Rdn), and was checked for confounding effects of classical meteorological variables through non-parametric regression algorithms. The number of EEC were significantly higher on days with high DHA (3.72-11.07 Pa, n = 87) compared to the low DHA (0.7-3.62 Pa, n = 260, p = 0.01), as well at days with low Rdn (0.21-1.64, n = 229) compared to the high Rdn (1.65-7.2, n = 118, p = 0.03). A difference between DHA and Rdn effects on the emergency events related to different categories of circulatory diseases points to a higher sensitivity of rheumatic and cerebro-vascular diseases to DHA, and ischaemic and hypertensive diseases to Rdn. Results suggest that APF could be considered as a meteorotropic factor capable of influencing circulatory system diseases.

Atmospheric pressure fluctuations in the far infrasound range and emergency transport events coded as circulatory system diseases

NASA Astrophysics Data System (ADS)

Didyk, L. A.; Gorgo, Yu. P.; Dirckx, J. J. J.; Bogdanov, V. B.; Buytaert, J. A. N.; Lysenko, V. A.; Didyk, N. P.; Vershygora, A. V.; Erygina, V. T.

2008-09-01

This study examines whether a relation exists between rapid atmospheric pressure fluctuations, attributed to the far infrasound frequency range (APF), and a number of emergency transport events coded as circulatory system diseases (EEC). Over an entire year, the average integral amplitudes of APF in the range of periods from 3 s to 120 s over each hour (HA) were measured. Daily dynamics of HA averaged over the year revealed a wave shape with smooth increase from night to day followed by decrease from day to night. The total daily number of EEC within the city of Kiev, Ukraine, was related to the daily mean of HA (DHA) and to the ratio of HA averaged over the day time to HA averaged over the night time (Rdn), and was checked for confounding effects of classical meteorological variables through non-parametric regression algorithms. The number of EEC were significantly higher on days with high DHA (3.72 11.07 Pa, n = 87) compared to the low DHA (0.7 3.62 Pa, n = 260, p = 0.01), as well at days with low Rdn (0.21 1.64, n = 229) compared to the high Rdn (1.65 7.2, n = 118, p = 0.03). A difference between DHA and Rdn effects on the emergency events related to different categories of circulatory diseases points to a higher sensitivity of rheumatic and cerebro-vascular diseases to DHA, and ischaemic and hypertensive diseases to Rdn. Results suggest that APF could be considered as a meteorotropic factor capable of influencing circulatory system diseases.

Influence of the ambient acceleration field upon acute acceleration tolerance in chickens

NASA Technical Reports Server (NTRS)

Smith, A. H.; Spangler, W. L.; Rhode, E. A.; Burton, R. R.

1979-01-01

The paper measured the acceleration tolerance of domestic fowl (Rhode Island Red cocks), acutely exposed to a 6 Gz field, as the time over which a normal heart rate can be maintained. This period of circulatory adjustment ends abruptly with pronounced bradycardia. For chickens which previously have been physiologically adapted to 2.5 -G field, the acute acceleration tolerance is greatly increased. The influence of the ambient acceleration field on the adjustment of the circulatory system appears to be a general phenomenon.

Towards a Fast Dynamic Model of the Human Circulatory System

DTIC Science & Technology

2011-10-06

heart chambers, and the local time-varying pressure is not prescribed anywhere. The effects of muscle contraction and relaxation on the circulatory...0.5 < S < 2) area during skeletal muscle contraction . Contraction only applied on the venous end of the vascular tree (1.25 < S < 2). For the... contraction , occurring during time (tam < t < tbm), and ∆Am is the maximum contraction amplitude. A visualization of the muscle contraction model is shown in

A case-control study relating railroad worker mortality to diesel exhaust exposure using a threshold regression model.

PubMed

Lee, Mei-Ling Ting; Whitmore, G A; Laden, Francine; Hart, Jaime E; Garshick, Eric

2009-01-01

A case-control study of lung cancer mortality in U.S. railroad workers in jobs with and without diesel exhaust exposure is reanalyzed using a new threshold regression methodology. The study included 1256 workers who died of lung cancer and 2385 controls who died primarily of circulatory system diseases. Diesel exhaust exposure was assessed using railroad job history from the US Railroad Retirement Board and an industrial hygiene survey. Smoking habits were available from next-of-kin and potential asbestos exposure was assessed by job history review. The new analysis reassesses lung cancer mortality and examines circulatory system disease mortality. Jobs with regular exposure to diesel exhaust had a survival pattern characterized by an initial delay in mortality, followed by a rapid deterioration of health prior to death. The pattern is seen in subjects dying of lung cancer, circulatory system diseases, and other causes. The unique pattern is illustrated using a new type of Kaplan-Meier survival plot in which the time scale represents a measure of disease progression rather than calendar time. The disease progression scale accounts for a healthy-worker effect when describing the effects of cumulative exposures on mortality.

Blacks' Death Rate Due to Circulatory Diseases Is Positively Related to Whites' Explicit Racial Bias.

PubMed

Leitner, Jordan B; Hehman, Eric; Ayduk, Ozlem; Mendoza-Denton, Rodolfo

2016-10-01

Perceptions of racial bias have been linked to poorer circulatory health among Blacks compared with Whites. However, little is known about whether Whites' actual racial bias contributes to this racial disparity in health. We compiled racial-bias data from 1,391,632 Whites and examined whether racial bias in a given county predicted Black-White disparities in circulatory-disease risk (access to health care, diagnosis of a circulatory disease; Study 1) and circulatory-disease-related death rate (Study 2) in the same county. Results revealed that in counties where Whites reported greater racial bias, Blacks (but not Whites) reported decreased access to health care (Study 1). Furthermore, in counties where Whites reported greater racial bias, both Blacks and Whites showed increased death rates due to circulatory diseases, but this relationship was stronger for Blacks than for Whites (Study 2). These results indicate that racial disparities in risk of circulatory disease and in circulatory-disease-related death rate are more pronounced in communities where Whites harbor more explicit racial bias.

Development of unconstrained heartbeat and respiration measurement system with pneumatic flow.

PubMed

Kurihara, Yosuke; Watanabe, Kajiro

2012-12-01

The management of health through daily monitoring of heartbeat and respiration signals is of major importance for early diagnosis to prevent diseases of the respiratory and circulatory system. However, such daily health monitoring is possible only if the monitoring system is physically and psychologically noninvasive. In this paper, an unconstrained method of measuring heartbeat and respiration signals, by using a thermistor to measure the air flows from the air mattress to an air tube accompanying the subject's heartbeat and respiration, is proposed. The SN ratio with interference by opening and closing of a door as environmental noise was compared with that obtained by the conventional condenser microphone method. As a result, the SN ratios with the condenser microphone method were 26.6 ± 4.2 dB for heartbeat and 27.8 ± 3.0 dB for respiration, whereas with the proposed method they were 34.9 ± 3.1 dB and 42.1 ± 2.5 dB, respectively.

Mean circulatory filling pressure: its meaning and measurement.

PubMed

Rothe, C F

1993-02-01

The volume-pressure relationship of the vasculature of the body as a whole, its vascular capacitance, requires a measurement of the mean circulatory filling pressure (Pmcf). A change in vascular capacitance induced by reflexes, hormones, or drugs has physiological consequences similar to a rapid change in blood volume and thus strongly influences cardiac output. The Pmcf is defined as the mean vascular pressure that exists after a stop in cardiac output and redistribution of blood, so that all pressures are the same throughout the system. The Pmcf is thus related to the fullness of the circulatory system. A change in Pmcf provides a uniquely useful index of a change in overall venous smooth muscle tone if the blood volume is not concomitantly changed. The Pmcf also provides an estimate of the distending pressure in the small veins and venules, which contain most of the blood in the body and comprise most of the vascular compliance. Thus the Pmcf, which is normally independent of the magnitude of the cardiac output, provides an estimate of the upstream pressure that determines the rate of flow returning to the heart.

[Importance of mechanical assist devices in acute circulatory arrest].

PubMed

Ferrari, Markus Wolfgang

2016-03-01

Mechanical assist devices are indicated for hemodynamic stabilization in acute circulatory arrest if conventional means of cardiopulmonary resuscitation are unable to re-establish adequate organ perfusion. Their temporary use facilitates further diagnostic and therapeutic options in selected patients, e.g. coronary angiography followed by revascularization.External thorax compression devices allow sufficient cardiac massage in case of preclinical or in-hospital circulatory arrest, especially under complex transfer conditions. These devices perform standardized thorax compressions at a rate of 80-100 per minute. Invasive mechanical support devices are used in the catheter laboratory or in the intensive care unit. Axial turbine pumps, e.g. the Impella, continuously pump blood from the left ventricle into the aortic root. The Impella can also provide right ventricle support by pumping blood from the vena cava into the pulmonary artery. So-called emergency systems or ECMO devices consist of a centrifugal pump and a membrane oxygenator allowing complete takeover of cardiac and pulmonary functions. Withdrawing blood from the right atrium and vena cava, oxygenated blood is returned to the abdominal aorta. Isolated centrifugal pumps provide left heart support without an oxygenator after transseptal insertion of a venous cannula into the left atrium.Mechanical assist devices are indicated for acute organ protection and hemodynamic stabilization for diagnostic and therapeutic measures as well as bridge to myocardial recovery. Future technical developments and better insights into the pathophysiology of mechanical circulatory support will broaden the spectrum of indications of such devices in acute circulatory arrest.

Directed Retrograde Cerebral Protection during Moderate Hypothermic Circulatory Arrest

PubMed Central

Yacoubian, Vahe; Jyrala, Aarne; Kay, Gregory L.

2006-01-01

There are many choices for neurologic protection for aortic arch surgery. Although numerous investigators have challenged the efficacy of retrograde cerebral perfusion, we have had good results with our application of this technique. We performed a retrospective review of 8 consecutive patients who underwent surgery from 1 June 2001 through 31 March 2003; the age range was 33 to 97 years. All patients required circulatory arrest and underwent retrograde cerebral perfusion with use of a tourniquet on the patients' left and right arms above the elbow to direct retrograde flow to the brain. Moderate hypothermia (around 24 °C nasopharyngeal) was used; circulatory arrest time ranged from 27 to 63 minutes. There was 1 late hospital death due to multiple-organ system failure. There were no neurologic complications (stroke or temporary neurologic dysfunction). There was no substantive neurologic or renal dysfunction in this cohort, in which moderate hypothermia was used. These results are comparable to those reported in the literature for similar patients. We conclude that, for patients who require circulatory arrest, directed retrograde cerebral perfusion at moderate nasopharyngeal hypothermia gives results comparable to those reported with other techniques. PMID:17215968

Circulatory nucleosome levels are significantly increased in early and late-onset preeclampsia.

PubMed

Zhong, Xiao Yan; Gebhardt, Stefan; Hillermann, Renate; Tofa, Kashefa Carelse; Holzgreve, Wolfgang; Hahn, Sinuhe

2005-08-01

Elevations in circulatory DNA, as measured by real-time PCR, have been observed in pregnancies with manifest preeclampsia. Recent reports have indicated that circulatory nucleosome levels are elevated in the periphery of cancer patients. We have now examined whether circulatory nucleosome levels are similarly elevated in cases with preeclampsia. Maternal plasma samples were prepared from 17 cases with early onset preeclampsia (<34 weeks gestation) with 14 matched normotensive controls, as well as 15 cases late-onset preeclampsia (>34 weeks gestation) with 10 matched normotensive controls. Levels of circulatory nucleosomes were quantified by commercial ELISA (enzyme-linked immunosorbant assay). The level of circulatory nucleosomes was significantly elevated in both study preeclampsia groups, compared to the matched normotensive control group (p = 0.000 and p = 0.001, respectively). Our data suggests that preeclampsia is associated with the elevated presence of circulatory nucleosomes, and that this phenomenon occurs in both early- and late-onset forms of the disorder. Copyright 2005 John Wiley & Sons, Ltd.

[Mortality rates of circulatory system diseases and malignant neoplasms in Zagreb population younger than sixty-five--call for alarm].

PubMed

Vizintin, Marina Polić; Mrcela, Nada Tomasović; Kovacić, Luka

2012-12-01

The aim of this work was to analyze the public health indicators for circulatory heart diseases and malignant neoplasms in the population younger than 65 in the City of Zagreb, Croatia, and compare them with the European Union (EU) countries. The purpose was to evaluate the situation and propose the public health preventive measures. The study population were Zagreb citizens aged 0-64 according to the 2001 census. Total Zagreb population was 779145, making 17.6% of total Croatian population. Data from the Croatian Bureau of Statistics and Dr Andrija Stampar Institute of Public Health were used. The standardized 0-64 mortality rates of the selected diseases 2006-2010 were used in the analysis. In 2010, the standardized mortality rates of all analyzed diseases were significantly higher in Zagreb population aged 0-64 than the EU averages except for cervical cancer. In 2010, the mortality rates in Zagreb population aged 0-64 were as follows: circulatory system diseases 61.22, ischemic heart disease 28.99, cerebrovascular diseases 12.51, malignant neoplasms 94.69, tracheal and lung cancer 24.92, breast cancer 21.08 and cervical cancer 2.05. Standardized mortality rates in Zagreb population aged 0-64 for circulatory system were lower than for Croatia (61.22 vs. 63.25), but higher for malignant neoplasms (94.69 vs. 91.2), except for cervical cancer (2.05 vs. 3.14). High standardized mortality rates for the selected diseases in the City of Zagreb, Croatia, were observed. The rates were higher in Zagreb population compared to EU averages except for cervical cancer. This situation urges revision of the public health strategy and implementation of more intensive preventive and screening measures to reduce the risk factors.

75 FR 9416 - Advisory Committee Information Hotline

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-02

... Drugs Advisory Committee 3014512542 Peripheral and Central Nervous System Drugs Advisory Committee... Devices Panel 3014512624 Circulatory System Devices Panel 3014512625 Clinical Chemistry and Clinical... about any particular advisory committee meeting, this system will provide interested parties with timely...

Development of the Baylor-Nikkiso centrifugal pump with a purging system for circulatory support.

PubMed

Naito, K; Miyazoe, Y; Aizawa, T; Mizuguchi, K; Tasai, K; Ohara, Y; Orime, Y; Glueck, J; Takatani, S; Noon, G P

1993-07-01

The Baylor-Nikkiso centrifugal pump is a magnetically coupled system with a V-ring seal separating the pump and the actuator chamber. To prevent thrombus formation behind the impeller and to extend the life of the pump to 2 weeks of continuous operation, we incorporated a purging chamber behind the V-ring seal. An external pump connected to this purging chamber infused fluid at a constant rate to wash the shaft-seal area. To evaluate the effectiveness of the purging system, we have carried out biventricular bypass experiments using calves. The purging system was successful in reducing the level of thrombus formation after 2 weeks of operation. The results of these studies confirmed that the Baylor-Nikkiso centrifugal pump with this purging system is suitable for at least 2 weeks of continuous operation as a circulatory support system.

Stimulation of cardiovascular adaptability during prolonged space exposure

NASA Technical Reports Server (NTRS)

Gorman, H. A.

1971-01-01

The deconditioning effects of weightlessness on the cardiovascular system of astronauts are discussed. It is believed that man cannot tolerate indefinite exposure to weightlessness without considerable circulatory deterioration. Analyses of data collected from space flights to date substantiate these beliefs, and confirm the fact that some form of compensation must be provided to keep the cardiovascular system of space travelers properly conditioned. Sequential pulsatile devices were investigated to produce periodic hydrostatic pressure gradients in the venous system of eight subhuman primates. Intermittent venous pooling of blood in the extremities triggers and stimulates the vascular reflex mechanisms of the cardiovascular system that may have significant benefits in maintaining the circulatory system in proper tone under weightless conditions. Electrocardiograms, blood pressure measurements, cardiac output and stroke volume determinations were used to evaluate the efficiency of the described technique. Results were amazingly consistent to indicate an efficient system for intermittently exercising the heart within safe and medically acceptable limits.

Control of respiration-driven retrograde flow in the subdiaphragmatic venous return of the Fontan circulation

PubMed Central

Vukicevic, M; Conover, T; Jaeggli, M; Zhou, J; Pennati, G; Hsia, TY; Figliola, RS

2014-01-01

Respiration influences the subdiaphragmatic venous return in the total cavopulmonary connection (TCPC) of the Fontan circulation whereby both the inferior vena cava (IVC) and hepatic vein flows can experience retrograde motion. Controlling retrograde flows could improve patient outcomes. Using a patient-specific model within a Fontan mock circulatory system with respiration, we inserted a valve into the IVC to examine its effects on local hemodynamics while varying retrograde volumes by changing vascular impedances. A bovine valved conduit reduced IVC retrograde flow to within 3% of antegrade flow in all cases. The valve closed only under conditions supporting retrograde flow and its effects on local hemodynamics increased with larger retrograde volume. Liver and TCPC pressures improved only while the valve leaflets were closed while cycle-averaged pressures improved only slightly (italic>1 mm Hg). Increased pulmonary vascular resistance raised mean circulation pressures but the valve functioned and cardiac output improved and stabilized. Power loss across the TCPC improved by 12–15% (pbold>0.05) with a valve. The effectiveness of valve therapy is dependent on patient vascular impedance. PMID:24814833

78 FR 104 - Advisory Committees; Tentative Schedule of Meetings for 2013

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-02

... Date(s), if needed, to be Committee. determined. Peripheral and Central Nervous System May 22. Drugs... be Devices Panel. determined. Circulatory System Devices Panel....... May 17, May 24, June 27...

[Oxygen-transporting function of the blood circulation system in sevoflurane anesthesia during myocardial revascularization under extracorporeal circulation].

PubMed

Skopets, A A; Lomivorotov, V V; Karakhalis, N B; Makarov, A A; Duman'ian, E S; Lomivorotova, L V

2009-01-01

The purpose of the study was to evaluate the efficiency of oxygen-transporting function of the circulatory system under sevoflurane anesthesia during myocardial revascularization operations under extracorporeal circulation. Twenty-five patients with coronary heart disease were examined. Mean blood pressure, heart rate, cardiac index, total peripheral vascular resistance index, pulmonary pressure, pulmonary wedge pressure, and central venous pressure were measured. Arterial and mixed venous blood oxygen levels, oxygen delivery and consumption index, arteriovenous oxygen difference, and glucose and lactate concentrations were calculated. The study has demonstrated that sevoflurane is an effective and safe anesthetic for myocardial revascularization operations in patients with coronary heart disease. The use of sevoflurane contributes to steady-state oxygen-transporting function of the circulatory system at all surgical stages.

Mock Circulatory System of the Fontan Circulation to Study Respiration Effects on Venous Flow Behavior

PubMed Central

Vukicevic, M.; Chiulli, J.A.; Conover, T.; Pennati, G.; Hsia, T.Y.; Figliola, R.S.

2013-01-01

We describe an in vitro model of the Fontan circulation with respiration to study subdiaphragmatic venous flow behavior. The venous and arterial connections of a total cavopulmonary connection (TCPC) test section were coupled with a physical lumped parameter (LP) model of the circulation. Intrathoracic and subdiaphragmatic pressure changes associated with normal breathing were applied. This system was tuned for two patients (5 years, 0.67 m2; 10 years, 1.2 m2) to physiological values. System function was verified by comparison to the analytical model on which it was based and by consistency with published clinical measurements. Overall, subdiaphragmatic venous flow was influenced by respiration. Flow within the arteries and veins increased during inspiration but decreased during expiration with retrograde flow in the inferior venous territories. System pressures and flows showed close agreement with the analytical LP model (p < 0.05). The ratio of the flow rates occurring during inspiration to expiration were within the clinical range of values reported elsewhere. The approach used to setup and control the model was effective and provided reasonable comparisons with clinical data. PMID:23644612

Anatomy and Physiology. Health Occupations Education. Teacher's Guide.

ERIC Educational Resources Information Center

East Texas State Univ., Commerce. Occupational Curriculum Lab.

Nine units on anatomy and physiology are presented in this teacher's guide. The units are the following: organization and general plan of the body; skeletal and muscular systems; digestive system; circulatory system; respiratory system; nervous system and special senses; urinary system; reproductive system; and endocrine glands. Each instructional…

76 FR 58019 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-19

... Ablation System to be used for the treatment of atrial fibrillation in patients who are undergoing open... catheter-based device developed for the treatment of atrial fibrillation. The system consists of the...

Noninvasive optoacoustic system for rapid diagnosis and management of circulatory shock

NASA Astrophysics Data System (ADS)

Petrov, Irene Y.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. N.; Seeton, Roger; Esenaliev, Rinat O.; Prough, Donald S.

2013-03-01

Circulatory shock can lead to death or severe complications, if not promptly diagnosed and effectively treated. Typically, diagnosis and management of circulatory shock are guided by blood pressure and heart rate. However, these variables have poor specificity, sensitivity, and predictive value. Early goal-directed therapy in septic shock patients, using central venous catheterization (CVC), reduced mortality from 46.5% to 30%. However, CVC is invasive and complication-prone. We proposed to use an optoacoustic technique for noninvasive, rapid assessment of peripheral and central venous oxygenation. In this work we used a medical grade optoacoustic system for noninvasive, ultrasound image-guided measurement of central and peripheral venous oxygenation. Venous oxygenation during shock declines more rapidly in the periphery than centrally. Ultrasound imaging of the axillary [peripheral] and internal jugular vein [central] was performed using the Vivid e (GE Healthcare). We built an optoacoustic interface incorporating an optoacoustic transducer and a standard ultrasound imaging probe. Central and peripheral venous oxygenations were measured continuously in healthy volunteers. To simulate shock-induced changes in central and peripheral oxygenation, we induced peripheral vasoconstriction in the upper extremity by using a cooling blanket. Central and peripheral venous oxygenations were measured before (baseline) and after cooling and after rewarming. During the entire experiment, central venous oxygenation was relatively stable, while peripheral venous oxygenation decreased by 5-10% due to cooling and recovered after rewarming. The obtained data indicate that noninvasive, optoacoustic measurements of central and peripheral venous oxygenation may be used for diagnosis and management of circulatory shock with high sensitivity and specificity.

The Anatomy Puzzle Book.

ERIC Educational Resources Information Center

Jacob, Willis H.; Carter, Robert, III

This document features review questions, crossword puzzles, and word search puzzles on human anatomy. Topics include: (1) Anatomical Terminology; (2) The Skeletal System and Joints; (3) The Muscular System; (4) The Nervous System; (5) The Eye and Ear; (6) The Circulatory System and Blood; (7) The Respiratory System; (8) The Urinary System; (9) The…

78 FR 49272 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-13

... committee regarding classification of triple chamber pacing system analyzers (PSAs) with external pacing... chamber PSA is intended to be used during the implant procedure of pacemakers and defibrillators...

[Morbidity profile and hospital expenses with elderly patients in Paraná State, Brazil, 2008-2012].

PubMed

Kernkamp, Clarice da Luz; Costa, Cassia Kely Favoretto; Massuda, Ely Mitie; Silva, Eraldo Schunk; Yamaguchi, Mirian Ueda; Bernuci, Marcelo Picinin

2016-07-21

Growth in the elderly population has increased both the demand for health services and healthcare expenses, with relevant consequences for economic stability. The current study aimed to analyze the morbidity profile and hospital expenses with elderly patients in relation to socioeconomic and demographic conditions in Paraná State, Brazil, from 2008 to 2012, applying principal components analysis and groupings. Regions with higher and lower economic and human development showed high prevalence of hospitalizations and costs pertaining to the circulatory and respiratory systems and cardiac diseases for males and females. In regions with intermediary development, diseases of the nervous system in men and of the circulatory system in women had the highest morbidity and hospital expenses. Thus, measures for prevention and health promotion in this elderly population should be targeted to regional investigations.

Scuba Science.

ERIC Educational Resources Information Center

Glickstein, Neil

2000-01-01

Introduces an integrated unit on scuba science. Studies oxygen in kinetic theory, Boyle's law, Charles's law, Dalton's law, human circulatory and respiratory systems, and diving dangers such as decompression sickness. (YDS)

Effects of Age and Exposure on the Health Status of U.S. Navy Divers.

DTIC Science & Technology

1984-01-01

Neuritis/Neuralgia/ Sciatica - 1.3 6.9 7.0 0 Facial Paralysis/Cerebral Paralysis 0 - - 0 - Diseases of the Circulatory System 15.6 18.3 24.9 38.3* 120.8...10.3 Otitts Externa/Other Ear Disorders 8.9 6.8 5.8 Deafness 3.5 3.4 2.6 Neuritis/Neuralgia/ Sciatica 2.6 2.6 - racial Paralysis/Cerebral Paralysis...20 18 10 9 Deafness 10 11 9 9 5 4 Neuritis/Neuralqia/ Sciatica 5 8 7 7 5 2 Facial Paralysis/Cerebral Paralysis 2 2 2 2 1 1 Diseases of the Circulatory

Miniature circulatory systems: A new exposure system for ecotoxicological effect assessments in riverine organisms.

PubMed

Feiner, Mona; Beggel, Sebastian; Geist, Juergen

2016-11-01

Long-term effect assessments in ecotoxicological investigations are important, yet there is a lack of suitable exposure systems for these experiments that can be used for riverine species. A cost-efficient miniature circulatory system was developed that was evaluated for its applicability in long-term exposures in 2 stream-dwelling species: brown trout (Salmo trutta) and an amphipod (Gammarus roeseli). In an egg-to-fry exposure of S. trutta, the toxicity of 2 reverse osmosis concentrates was investigated as examples. Control hatching rate of yolk sac fry was 75 ± 7% and thus complies with the Organisation for Economic Co-operation and Development validity criterion (≥66%). The reverse osmosis concentrates did not impair the hatching rate in any tested concentration. In G. roeseli, mortality rates remained below 20% during a 21-d cultivation, fulfilling the common validity criterion in ecotoxicological testing. Mortality was significantly lower when the species was fed with conditioned alder leaves instead of an artificial shrimp food. Finally, a toxicity test on G. roeseli using copper as the test substance revealed median lethal concentration (LC50) values of 156 μg/L after 96 h and 99 μg/L after 264 h, which is in line with literature findings using other accepted exposure units. In conclusion, the miniature circulatory system provides a novel and cost-efficient exposure system for long-term investigations on riverine species that may also be applicable for other species of fishes and macroinvertebrates. Environ Toxicol Chem 2016;35:2827-2833. © 2016 SETAC. © 2016 SETAC.

Recent advances in computational methodology for simulation of mechanical circulatory assist devices

PubMed Central

Marsden, Alison L.; Bazilevs, Yuri; Long, Christopher C.; Behr, Marek

2014-01-01

Ventricular assist devices (VADs) provide mechanical circulatory support to offload the work of one or both ventricles during heart failure. They are used in the clinical setting as destination therapy, as bridge to transplant, or more recently as bridge to recovery to allow for myocardial remodeling. Recent developments in computational simulation allow for detailed assessment of VAD hemodynamics for device design and optimization for both children and adults. Here, we provide a focused review of the recent literature on finite element methods and optimization for VAD simulations. As VAD designs typically fall into two categories, pulsatile and continuous flow devices, we separately address computational challenges of both types of designs, and the interaction with the circulatory system with three representative case studies. In particular, we focus on recent advancements in finite element methodology that has increased the fidelity of VAD simulations. We outline key challenges, which extend to the incorporation of biological response such as thrombosis and hemolysis, as well as shape optimization methods and challenges in computational methodology. PMID:24449607

77 FR 16038 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-19

... vote on information related to the PMA for the Subcutaneous Implantable Cardioverter Defibrillator (S-ICD) System sponsored by Cameron Health, Inc. The S-ICD is the first implantable defibrillator that...

[Testing system design and analysis for the execution units of anti-thrombotic device].

PubMed

Li, Zhelong; Cui, Haipo; Shang, Kun; Liao, Yuehua; Zhou, Xun

2015-02-01

In an anti-thrombotic pressure circulatory device, relays and solenoid valves serve as core execution units. Thus the therapeutic efficacy and patient safety of the device will directly depend on their performance. A new type of testing system for relays and solenoid valves used in the anti-thrombotic device has been developed, which can test action response time and fatigue performance of relay and solenoid valve. PC, data acquisition card and test platform are used in this testing system based on human-computer interaction testing modules. The testing objectives are realized by using the virtual instrument technology, the high-speed data acquisition technology and reasonable software design. The two sets of the system made by relay and solenoid valve are tested. The results proved the universality and reliability of the testing system so that these relays and solenoid valves could be accurately used in the antithrombotic pressure circulatory equipment. The newly-developed testing system has a bright future in the aspects of promotion and application prospect.

Relation of Total and Cardiovascular Death Rates to Climate System, Temperature, Barometric Pressure, and Respiratory Infection.

PubMed

Schwartz, Bryan G; Qualls, Clifford; Kloner, Robert A; Laskey, Warren K

2015-10-15

A distinct seasonal pattern in total and cardiovascular death rates has been reported. The factors contributing to this pattern have not been fully explored. Seven locations (average total population 71,354,000) were selected where data were available including relatively warm, cold, and moderate temperatures. Over the period 2004 to 2009, there were 2,526,123 all-cause deaths, 838,264 circulatory deaths, 255,273 coronary heart disease deaths, and 135,801 ST-elevation myocardial infarction (STEMI) deaths. We used time series and multivariate regression modeling to explore the association between death rates and climatic factors (temperature, dew point, precipitation, barometric pressure), influenza levels, air pollution levels, hours of daylight, and day of week. Average seasonal patterns for all-cause and cardiovascular deaths were very similar across the 7 locations despite differences in climate. After adjusting for multiple covariates and potential confounders, there was a 0.49% increase in all-cause death rate for every 1°C decrease. In general, all-cause, circulatory, coronary heart disease and STEMI death rates increased linearly with decreasing temperatures. The temperature effect varied by location, including temperature's linear slope, cubic fit, positional shift on the temperature axis, and the presence of circulatory death increases in locally hot temperatures. The variable effect of temperature by location suggests that people acclimatize to local temperature cycles. All-cause and circulatory death rates also demonstrated sizable associations with influenza levels, dew point temperature, and barometric pressure. A greater understanding of how climate, temperature, and barometric pressure influence cardiovascular responses would enhance our understanding of circulatory and STEMI deaths. Copyright © 2015 Elsevier Inc. All rights reserved.

Practice pattern and professional issues of nurse practitioners in mechanical circulatory support programs in the United States: a survey report.

PubMed

Casida, Jesus M; Pastor, Jessica

2012-09-01

Few data-based reports about the role and work environment of advanced practice nurses, specifically nurse practitioners in mechanical circulatory support programs, have been published. To describe the practice pattern and professional issues confronted by nurse practitioners in the rapidly evolving and expanding mechanical circulatory support programs in the United States. A descriptive research design was employed using the data from the 2010 mechanical circulatory support nurses survey. Quantitative and qualitative data that pertained to the demographic and practice profiles as well as barriers and overall issues faced by the nurse practitioners in their clinical practice were analyzed. Nonrandom sample of 48 nurse practitioners from 95 mechanical circulatory support programs nationwide. The practice pattern of nurse practitioners in mechanical circulatory support programs is similar to the practice pattern reported for nurse practitioners in acute and critical care settings. However, only 44% and 10% of nurse practitioners in mechanical circulatory support programs are authorized to admit and transfer patients into and out of the hospital, respectively. High workload, lack of institutional support, knowledge deficit, role ambiguity, lack of professional recognition, and burnout were the common issues faced by the participants in their clinical practice. The results provide preliminary evidence on the practice pattern, restrictions, and work environment issues that may threaten the viability of an mechanical circulatory support program in which nurse practitioners play a crucial role. Implications for clinical practice, research, and policy development are discussed.

A Numerical Modeling of A Vascular Implantable Cardiac Endovascular Assistant (AVICENA)

NASA Astrophysics Data System (ADS)

Rahmani, Shahrokh; Tehrani, Pedram; Karimi, Alireza; Alizadeh, Mansour; Navidbakhsh, Mahdi

2015-10-01

Cardiovascular diseases have been recently shown to have a pivotal role in human death and endangers lives of many people around the world. One of the most common cardiovascular diseases is poor performance of left ventricle. In this case, the ventricle cannot pump the blood into the aorta and circulatory system with a suitable power which is required for normal circulatory system. AVICENA is a new cardiac assist device which is implanted into the aorta to help the ventricle to pump the blood into circulatory system with more power and to make a better perfusion of the coronary arteries as well. To reach a desire value of rotational speed of the pump, a control circuit is designed for counterpulsation of AVICENA based on the outcomes from previous studies. This control circuit uses a PID controller. The present study aims to simulate the blood flow through the balloon part of AVICENA in a heart cycle with focusing on the calculation of its pump rotational speed by controlling the electrical current of the pump. Results revealed that the desired rotational speed of the pump can be achieved according to the previous aorta pressure cycle by electrical current control which is higher during balloon inflation in comparison with balloon deflation. These findings may have implications not only for understanding the performance of AVICENA but also to help cardiac mechanics experts to improve the shortcoming of this newborn device.

[The comparison of the two Ottoman books of anatomy (17-19th centuries) with regard to the circulatory system].

PubMed

Uluçam, E; Gökçe, N

2000-01-01

17th and 19th centuries were particularly important for the development of the Ottoman medicine. Westernization which had already started in the 17th century continued along the 19th and the early 20th centuries. Turkish physicians began to contact with their European colleagues and in this period Latin medical terminology began to appear in the Ottoman medical literature. Sirvanli Semseddin Itaki's work of the 17th century, the Teşrihü'l Ebdan ve Tercüman-i Kibale-i Feylesufan, is the first illustrated Turkish manuscript of anatomy. The illustrations are qualified as developed examples, compared with the medical literature and knowledge of the period. In the 19th century, Sanizade Mehmet Ataullah Efendi (1771-1826) wrote a modern book of anatomy for the Ottoman medical doctors. Miyarü'l Etibba was one of the earliest printed medical books in Turkish. The second volume of Sanizade's Hamse, Miratü'l Ebdan fi Teşrih-i Azai'l Insan is the first printed Ottoman book on anatomy. In Usulü't-Tabia, the third volume of Hamse, the circulatory system is discussed. In this article, we studied the circulatory system described in Semseddin Itaki's Teşrih-ül Ebdan ve Tercüman-i Kibale-i Feylesufan and in Sanizade's Usulü't-Tabia and compared them.

[The comparison of the two Ottoman books of anatomy (17-19th centuries) with regard to the circulatory system].

PubMed

Ulucam, E; Gokce, N

2000-01-01

17th and 19th centuries were particularly important for the development of te Ottoman medicine. Westernization which had already started in the 17th century continued along the 19th and the early 20th centuries. Turkish physicians began to contact with their European colleagues and in this period Latin medical terminology began to appear in the Ottoman medical literature. Sirvanli Semseddin Itaki's work of the 17th century, the Teşrihü'l Ebdan ve Tercüman-i Kibale-i Feylesufan, is the first illustrated Turkish manuscript of anatomy. The illustrations are qualified as developed examples, compared with the medical literature and knowledge of the period. In the 19th century, Sanizade Mehmet Ataullah Efendi (1771-1826) wrote a modern book of anatomy for the Ottoman medical doctors. Miyarü'l Etibba was one of the earliest printed medical books in Turkish. The second volume of Sanizade's Hamse, Miratü'l Ebdan fi Tesrih-i-Azai'l Insan is the first printed Ottoman book on anatomy. In Usulü't-Tabia, the third volume of Hamse, the circulatory system is discussed. In this article, we studied the circulatory system described in Semseddin Itaki's Teşrih-ül Ebdan ve Tercüman-i-Kibale-i Feylesufan and in Sanizade's Usulü't-Tabia and compared them.

Dependence of pentobarbital kinetics upon the dose of the drug and its pharmacodynamic effects.

PubMed

Kozlowski, K H; Szaykowski, A; Danysz, A

1977-01-01

Pentobarbital (PB), at dose range of 20--50 mg/kg, displays in rabbits non-linear, dose-dependent kinetics. Pharmacokinetics parameters of drug elimination depend largely upon the dose, while the distribution phase is dose-independent. The rate of disappearance of PB from the central compartment (plasma) decreases with the increase of the dose. The analysis of pharmacodynamic parameters has shown that this dose-dependent retardation of PB elimination is probably caused by an impairment of metabolic processes, resulting from disturbance of the circulatory system. A close correlation has been found between the hypotensive effect of PB and the elimination constant, k13, and also between the hypotensive effect and beta.Vd(extrap), a coefficient proportional to the rate of metabolism of PB [23, 29]. The results indicate the necessity of considering the changes in the functional state of the organism, related to the action of a drug, in pharmacokinetic studies.

Gut microbial metabolite TMAO enhances platelet hyperreactivity and thrombosis risk

PubMed Central

Zhu, Weifei; Gregory, Jill C.; Org, Elin; Buffa, Jennifer A.; Gupta, Nilaksh; Wang, Zeneng; Li, Lin; Fu, Xiaoming; Wu, Yuping; Mehrabian, Margarete; Sartor, R. Balfour; McIntyre, Thomas M.; Silverstein, Roy L.; Tang, W.H. Wilson; DiDonato, Joseph A.; Brown, J. Mark; Lusis, Aldons J.; Hazen, Stanley L.

2016-01-01

SUMMARY Normal platelet function is critical to blood hemostasis and maintenance of a closed circulatory system. Heightened platelet reactivity, however, is associated with cardiometabolic diseases and enhanced potential for thrombotic events. We now show gut microbes, through generation of trimethylamine N-oxide (TMAO), directly contribute to platelet hyperreactivity and enhanced thrombosis potential. Plasma TMAO levels in subjects (N>4000) independently predicted incident (3 yr) thrombosis (heart attack, stroke) risk. Direct exposure of platelets to TMAO enhanced submaximal stimulus-dependent platelet activation from multiple agonists through augmented Ca2+ release from intracellular stores. Animal model studies employing dietary choline or TMAO, germ-free mice, and microbial transplantation, collectively confirm a role for gut microbiota and TMAO in modulating platelet hyperresponsiveness and thrombosis potential, and identify microbial taxa associated with plasma TMAO and thrombosis potential. Collectively, the present results reveal a previously unrecognized mechanistic link between specific dietary nutrients, gut microbes, platelet function, and thrombosis risk. PMID:26972052

40 CFR 116.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... respiration by means of a lung structure permitting gaseous exchange between air and the circulatory system; Aquatic animals means appropriately sensitive wholly aquatic animals which carry out respiration by means...

40 CFR 116.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... respiration by means of a lung structure permitting gaseous exchange between air and the circulatory system; Aquatic animals means appropriately sensitive wholly aquatic animals which carry out respiration by means...

On the elimination of pulse wave velocity in stroke volume determination from the ultralow-frequency displacement ballistocardiogram.

DOT National Transportation Integrated Search

1964-03-01

A hydrodynamic model of the systemic circulatory system was mounted on an ultralow-frequency ballistocardiograph (ULF-BCG). The relationship between stroke volume and ballistocardiographic amplitude was investigated for different pulse wave velocitie...

Passive safety injection system using borated water

DOEpatents

Conway, Lawrence E.; Schulz, Terry L.

1993-01-01

A passive safety injection system relies on differences in water density to induce natural circulatory flow patterns which help maintain prescribed concentrations of boric acid in borated water, and prevents boron from accumulating in the reactor vessel and possibly preventing heat transfer.

The heart of a dragon: 3D anatomical reconstruction of the 'scaly-foot gastropod' (Mollusca: Gastropoda: Neomphalina) reveals its extraordinary circulatory system.

PubMed

Chen, Chong; Copley, Jonathan T; Linse, Katrin; Rogers, Alex D; Sigwart, Julia D

2015-01-01

The 'scaly-foot gastropod' (Chrysomallon squamiferum Chen et al., 2015) from deep-sea hydrothermal vent ecosystems of the Indian Ocean is an active mobile gastropod occurring in locally high densities, and it is distinctive for the dermal scales covering the exterior surface of its foot. These iron-sulfide coated sclerites, and its nutritional dependence on endosymbiotic bacteria, are both noted as adaptations to the extreme environment in the flow of hydrogen sulfide. We present evidence for other adaptations of the 'scaly-foot gastropod' to life in an extreme environment, investigated through dissection and 3D tomographic reconstruction of the internal anatomy. Our anatomical investigations of juvenile and adult specimens reveal a large unganglionated nervous system, a simple and reduced digestive system, and that the animal is a simultaneous hermaphrodite. We show that Chrysomallon squamiferum relies on endosymbiotic bacteria throughout post-larval life. Of particular interest is the circulatory system: Chrysomallon has a very large ctenidium supported by extensive blood sinuses filled with haemocoel. The ctenidium provides oxygen for the host but the circulatory system is enlarged beyond the scope of other similar vent gastropods. At the posterior of the ctenidium is a remarkably large and well-developed heart. Based on the volume of the auricle and ventricle, the heart complex represents approximately 4 % of the body volume. This proportionally giant heart primarily sucks blood through the ctenidium and supplies the highly vascularised oesophageal gland. Thus we infer the elaborate cardiovascular system most likely evolved to oxygenate the endosymbionts in an oxygen poor environment and/or to supply hydrogen sulfide to the endosymbionts. This study exemplifies how understanding the autecology of an organism can be enhanced by detailed investigation of internal anatomy. This gastropod is a large and active species that is abundant in its hydrothermal vent field ecosystem. Yet all of its remarkable features-protective dermal sclerites, circulatory system, high fecundity-can be viewed as adaptations beneficial to its endosymbiont microbes. We interpret these results to show that, as a result of specialisation to resolve energetic needs in an extreme chemosynthetic environment, this dramatic dragon-like species has become a carrying vessel for its bacteria.

Mechanical Circulatory Support of the Critically Ill Child Awaiting Heart Transplantation

PubMed Central

Gazit, Avihu Z; Gandhi, Sanjiv K; C Canter, Charles

2010-01-01

The majority of children awaiting heart transplantation require inotropic support, mechanical ventilation, and/or extracorporeal membrane oxygenation (ECMO) support. Unfortunately, due to the limited pool of organs, many of these children do not survive to transplant. Mechanical circulatory support of the failing heart in pediatrics is a new and rapidly developing field world-wide. It is utilized in children with acute congestive heart failure associated with congenital heart disease, cardiomyopathy, and myocarditis, both as a bridge to transplantation and as a bridge to myocardial recovery. The current arsenal of mechanical assist devices available for children is limited to ECMO, intra-aortic balloon counterpulsation, centrifugal pump ventricular assist devices, the DeBakey ventricular assist device Child; the Thoratec ventricular assist device; and the Berlin Heart. In the spring of 2004, five contracts were awarded by the National Heart, Lung and Blood Institute to support preclinical development for a range of pediatric ventricular assist devices and similar circulatory support systems. The support of early development efforts provided by this program is expected to yield several devices that will be ready for clinical trials within the next few years. Our work reviews the current international experience with mechanical circulatory support in children and summarizes our own experience since 2005 with the Berlin Heart, comparing the indications for use, length of support, and outcome between these modalities. PMID:21286278

Periodontal Diseases

MedlinePlus

... already are in the process of dissecting the dynamics of these bacterial communities. This research may give ... shed from chronic periodontal infections enter the circulatory system and may contribute to diseases of the heart ...

Universal structures of normal and pathological heart rate variability.

PubMed

Gañán-Calvo, Alfonso M; Fajardo-López, Juan

2016-02-25

The circulatory system of living organisms is an autonomous mechanical system softly tuned with the respiratory system, and both developed by evolution as a response to the complex oxygen demand patterns associated with motion. Circulatory health is rooted in adaptability, which entails an inherent variability. Here, we show that a generalized N-dimensional normalized graph representing heart rate variability reveals two universal arrhythmic patterns as specific signatures of health one reflects cardiac adaptability, and the other the cardiac-respiratory rate tuning. In addition, we identify at least three universal arrhythmic profiles whose presences raise in proportional detriment of the two healthy ones in pathological conditions (myocardial infarction; heart failure; and recovery from sudden death). The presence of the identified universal arrhythmic structures together with the position of the centre of mass of the heart rate variability graph provide a unique quantitative assessment of the health-pathology gradient.

Radiation-associated circulatory disease mortality in a pooled analysis of 77,275 patients from the Massachusetts and Canadian tuberculosis fluoroscopy cohorts.

PubMed

Tran, Van; Zablotska, Lydia B; Brenner, Alina V; Little, Mark P

2017-03-13

High-dose ionising radiation is associated with circulatory disease. Risks associated with lower-dose (<0.5 Gy) exposures remain unclear, with little information on risk modification by age at exposure, years since exposure or dose-rate. Tuberculosis patients in Canada and Massachusetts received multiple diagnostic x-ray fluoroscopic exposures, over a wide range of ages, many at doses <0.5 Gy. We evaluated risks of circulatory-disease mortality associated with <0.5 Gy radiation exposure in a pooled cohort of 63,707 patients in Canada and 13,568 patients in Massachusetts. Under 0.5 Gy there are increasing trends for all circulatory disease (n = 10,209; excess relative risk/Gy = 0.246; 95% CI 0.036, 0.469; p = 0.021) and for ischaemic heart disease (n = 6410; excess relative risk/Gy = 0.267; 95% CI 0.003, 0.552; p = 0.048). All circulatory-disease and ischaemic-heart-disease risk reduces with increasing time since exposure (p < 0.005). Over the entire dose range, there are negative mortality dose trends for all circulatory disease (p = 0.014) and ischaemic heart disease (p = 0.003), possibly due to competing causes of death over this dose interval.These results confirm and extend earlier findings and strengthen the evidence for circulatory-disease mortality radiation risk at doses <0.5 Gy. The limited information on well-known lifestyle/medical risk factors for circulatory disease implies that confounding of the dose trend cannot be entirely excluded.

What's Blood?

MedlinePlus

... Body Make Blood? It's not made in a kitchen, but blood has ingredients, just like a recipe. ... these ingredients together and you have blood — an essential part of the circulatory system. Thanks to your ...

[Vascular dental anaesthesias and their mechanism].

PubMed

Petrikas, A Zh; Iakupova, L A; Medvedev, A V; Borodina, O E; Egorova, V A; Diuba

2010-01-01

By their mechanism of action local anaesthesia methods were divided into diffused and vascular. Intraosseous, intraseptal and intraligamental anesthaesias are vascular ones at capillary-venous system level. Circulatory mechanism besides effectiveness increased more than 2-fold and also promotes enhancement of cardiovascular system responses.

Integrating Computer/Multimedia Technology in a High School Biology Curriculum.

ERIC Educational Resources Information Center

Matray, Paul; Proulx, Steve

1995-01-01

Discusses hardware and software used to teach scientific method, ecology, evolution, mitosis and meiosis, photosynthesis, cellular respiration, circulatory and respiratory systems, reproduction and drugs, behavior, and genetics. (MKR)

Aortic arch reconstruction: deep and moderate hypothermic circulatory arrest with selective antegrade cerebral perfusion.

PubMed

Wu, YanWen; Xiao, LiQiong; Yang, Ting; Wang, Lei; Chen, Xin

2017-07-01

To compare the effects of moderate and deep hypothermic circulatory arrest (DHCA) with selective antegrade cerebral perfusion (SACP) during aortic arch surgery in adult patients and to offer the evidence for the detection of the temperature which provides best brain protection in the subjects who accept aortic arch reconstruction surgery. A total of 109 patients undergoing surgery of the aortic arch were divided into the moderate hypothermic circulatory arrest group (Group I) and the deep hypothermic circulatory arrest group (Group II). We recorded the data of the patients and their cardiopulmonary bypass (CPB) time, aortic clamping time, SACP time and postoperative anesthetized recovery time, tracheal intubation time, time in the intensive care unit (ICU) and postoperative neurologic dysfunction. Patient characteristics were similar in the two groups. There were four patients who died in Group II and 1 patient in Group I. There were no significant differences in aortic clamping time of each group (111.4±58.4 vs. 115.9±16.2) min; SACP time (27.4±5.9 vs. 23.5±6.1) min of the moderate hypothermic circulatory arrest group and the deep hypothermic circulatory arrest group; there were significant differences in cardiopulmonary bypass time (207.4±20.9 vs. 263.8±22.6) min, postoperative anesthetized recovery time (19.0±11.1 vs. 36.8±25.3) hours, extubation time (46.4±15.1 vs. 64.4±6.0) hours; length of stay in the intensive care unit (ICU) (4.7±1.7 vs. 8±2.3) days and postoperative neurologic dysfunction in the two groups. Compared to deep hypothermic circulatory arrest, moderate hypothermic circulatory arrest can provide better brain protection and achieve good clinical results.

Simple retrograde cerebral perfusion is as good as complex antegrade cerebral perfusion for hemiarch replacement.

PubMed

Tanaka, Akiko; Estrera, Anthony L

2018-01-01

Cerebral complication is a major concern after aortic arch surgery, which may lead to death. Thus, cerebral protection strategy plays the key role to obtain respectable results in aortic arch repair. Deep hypothermic circulatory arrest was introduced in 1970s to decrease the ischemic insults to the brain. However, safe duration of circulatory arrest time was limited to 30 minutes. The 1990s was the decade of evolution for cerebral protection, in which two adjuncts for deep hypothermic circulatory arrest were introduced: retrograde and antegrade cerebral perfusion (ACP) techniques. These two cerebral perfusion techniques significantly decreased incidence of postoperative neurological dysfunction and mortality after aortic arch surgery. Although there are no large prospective studies that demonstrate which perfusion technique provide better outcomes, multiple retrospective studies implicate that ACP may decrease cerebral complications compared to retrograde cerebral perfusion (RCP) when a long circulatory arrest time is required during aortic arch reconstructions. To date, many surgeons favor ACP over RCP during a complex aortic arch repair, such as total arch replacement and hybrid arch replacement. However, the question is whether the use of ACP is necessary during a short, limited circulatory arrest time, such as hemiarch replacement? There is a paucity of data that proves the advantages of a complex ACP over a simple RCP for a short circulatory arrest time. RCP with deep hypothermic circulatory arrest is the simple, efficient cerebral protection technique with minimal interference to the surgical field-and it potentially allows to flush atheromatous debris out from the arch vessels. Thus, it is the preferred adjunct to deep hypothermic circulatory arrest during hemiarch replacement in our institution.

Simple retrograde cerebral perfusion is as good as complex antegrade cerebral perfusion for hemiarch replacement

PubMed Central

Tanaka, Akiko

2018-01-01

Cerebral complication is a major concern after aortic arch surgery, which may lead to death. Thus, cerebral protection strategy plays the key role to obtain respectable results in aortic arch repair. Deep hypothermic circulatory arrest was introduced in 1970s to decrease the ischemic insults to the brain. However, safe duration of circulatory arrest time was limited to 30 minutes. The 1990s was the decade of evolution for cerebral protection, in which two adjuncts for deep hypothermic circulatory arrest were introduced: retrograde and antegrade cerebral perfusion (ACP) techniques. These two cerebral perfusion techniques significantly decreased incidence of postoperative neurological dysfunction and mortality after aortic arch surgery. Although there are no large prospective studies that demonstrate which perfusion technique provide better outcomes, multiple retrospective studies implicate that ACP may decrease cerebral complications compared to retrograde cerebral perfusion (RCP) when a long circulatory arrest time is required during aortic arch reconstructions. To date, many surgeons favor ACP over RCP during a complex aortic arch repair, such as total arch replacement and hybrid arch replacement. However, the question is whether the use of ACP is necessary during a short, limited circulatory arrest time, such as hemiarch replacement? There is a paucity of data that proves the advantages of a complex ACP over a simple RCP for a short circulatory arrest time. RCP with deep hypothermic circulatory arrest is the simple, efficient cerebral protection technique with minimal interference to the surgical field—and it potentially allows to flush atheromatous debris out from the arch vessels. Thus, it is the preferred adjunct to deep hypothermic circulatory arrest during hemiarch replacement in our institution. PMID:29682460

Transition of intestinal fatty acid-binding protein on hypothermic circulatory arrest with cardiopulmonary bypass.

PubMed

Kano, Hiroya; Takahashi, Hiroaki; Inoue, Takeshi; Tanaka, Hiroshi; Okita, Yutaka

2017-04-01

Intestinal fatty acid-binding protein (I-FABP) is increasingly employed as a highly specific marker of intestinal necrosis. However, the value of this marker associated with cardiovascular surgery with hypothermic circulatory arrest is unclear. The aim of this study was to measure serum I-FABP levels and provide the transition of I-FABP levels with hypothermic circulatory arrest to help in the management of intestinal perfusion. From August 2011 to September 2013, 33 consecutive patients who had aortic arch surgery with hypothermic circulatory arrest or heart valve surgery performed were enrolled in the study. Twenty patients had aortic surgery with hypothermic (23-29°C) circulatory arrest and 13 patients had heart valve surgery with cardiopulmonary bypass (33°C). I-FABP levels increased, both in patients undergoing aortic surgery with hypothermic circulatory arrest and heart valve surgery with cardiopulmonary bypass, reaching peak levels shortly after the administration of protamine. I-FABP levels in patients with aortic surgery were significantly higher with circulatory arrest. They reached peak levels immediately after recirculation and there was a significant drop at the end of surgery (p<0.001). I-FABP levels in heart valve surgery were gradually increased, with the highest at the administration of protamine; they gradually decreased. Peak I-FABP levels were significantly higher in patients undergoing aortic surgery with hypothermic circulatory arrest than in patients with heart valve surgery. However, no postoperative reperfusion injury occurred in the intestinal tract due to the use of hypothermic organ protection. Plasma I-FABP monitoring could be a valuable method for finding an intestinal ischemia in patients with cardiovascular surgery.

Attrition reactor system

DOEpatents

Scott, Charles D.; Davison, Brian H.

1993-01-01

A reactor vessel for reacting a solid particulate with a liquid reactant has a centrifugal pump in circulatory flow communication with the reactor vessel for providing particulate attrition, resulting in additional fresh surface where the reaction can occur.

Freedom poverty: a new tool to identify the multiple disadvantages affecting those with CVD.

PubMed

Callander, Emily J; Schofield, Deborah J; Shrestha, Rupendra N

2013-06-20

It is recognised that CVD affects an individual's financial situation, placing them in income poverty. However, recent developments in poverty measurement practice recognises other forms of disadvantage other than low income, such as poor health and insufficient education also affect living standards. Using the Freedom Poverty Measure, the multiple forms of disadvantage experienced by those with no health condition, heart disease, other diseases of the circulatory system, and all other health conditions was assessed using data on the adult Australian population contained in the 2003 Survey of Disability, Ageing and Carers. 24% of those with heart disease and 23% of those with other diseases of the circulatory system were in freedom poverty, suffering from multiple forms of disadvantage. Those with heart disease and those with other diseases of the circulatory system were around three times more likely to be in freedom poverty (OR 3.02, 95% CI: 2.29-3.99, p<.0001; OR 2.78, 95% CI: 1.94-3.98, p<.0001) than those with no health condition. Recognising the multiple forms of disadvantage suffered by those with CVD provides a clearer picture of their living standards than just looking at their income alone and the high proportion of individuals with CVD that are suffering from multiple forms of disadvantage should make them a target for policy makers wishing to improve living standards. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

The effects of three concept mapping strategies on seventh-grade students' science achievement at an urban middle school

NASA Astrophysics Data System (ADS)

Dosanjh, Navdeep Kaur

2011-12-01

There is great concern over students' poor science achievement in the United States. Due to the lack of science achievement, students are not pursing science related careers resulting in an increase in outsourcing to other countries. Learning strategies such as concept mapping may ameliorate this situation by providing students with tools that encourage meaningful learning. The purpose of this quasi-experimental study was to measure the effects of three concept mapping learning strategies (concept identifying, proposition identifying, student generated) on urban middle school students' understanding of the circulatory system. Three intact classes of seventh-grade students were assigned to one of the three concept mapping strategies. The students were given a pretest on the circulatory system then learned and used their respective concept mapping strategies while learning about the circulatory system. At the conclusion of the study, students' science achievement was measured by performance on an achievement test and rubric scores of their respective concept identifying, proposition identifying, and student generated concept maps. The results of the study suggest that all three of the concept mapping strategies are effective in increasing students' science achievement. Additionally, the moderate significant correlations between the posttest and concept map scores of the current study established that concept maps are a useful measure of student knowledge. Lastly, the results of the current study also suggest that the concept identifying mapping strategy may be a useful scaffold in instructing students how to develop student generated concept maps.

Relationships between Digestive, Circulatory, and Urinary Systems in Portuguese Primary Textbooks

ERIC Educational Resources Information Center

Carvalho, Graça S.; Clèment, Pierre

2007-01-01

In this study, 63 Portuguese primary schoolbooks (1920-2005) were analyzed. The analysis focused on text information (reference to blood absorption and association of the digestive system to other human systems) and on information from images (presence or absence of image "confusion" (when the sequence of the digestive tract is not…

Predicting Total Sick Days Experienced by an Active Duty Military Population

DTIC Science & Technology

1990-05-07

system. 0 a - MDC 05, Disease and disorders of the circulatory system. o ma - MDC 17, Myeloproliferative diseases and disorders, and 0poorly...differentiated neoplasms . < z- MDC 18, Infectious and parasitic diseases (systemic or C fi z -4unspecified sites). M x MDCG3: Ob/Gyn. - MDC 13, Diseases and

MicroRNAs as Peripheral Biomarkers in Aging and Age-Related Diseases.

PubMed

Kumar, S; Vijayan, M; Bhatti, J S; Reddy, P H

2017-01-01

MicroRNAs (miRNAs) are found in the circulatory biofluids considering the important molecules for biomarker study in aging and age-related diseases. Blood or blood components (serum/plasma) are primary sources of circulatory miRNAs and can release these in cell-free form either bound with some protein components or encapsulated with microvesicle particles, called exosomes. miRNAs are quite stable in the peripheral circulation and can be detected by high-throughput techniques like qRT-PCR, microarray, and sequencing. Intracellular miRNAs could modulate mRNA activity through target-specific binding and play a crucial role in intercellular communications. At a pathological level, changes in cellular homeostasis lead to the modulation of molecular function of cells; as a result, miRNA expression is deregulated. Deregulated miRNAs came out from cells and frequently circulate in extracellular body fluids as part of various human diseases. Most common aging-associated diseases are cardiovascular disease, cancer, arthritis, dementia, cataract, osteoporosis, diabetes, hypertension, and neurodegenerative diseases such as Alzheimer's disease, Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Variation in the miRNA signature in a diseased peripheral circulatory system opens up a new avenue in the field of biomarker discovery. Here, we measure the biomarker potential of circulatory miRNAs in aging and various aging-related pathologies. However, further more confirmatory researches are needed to elaborate these findings at the translation level. © 2017 Elsevier Inc. All rights reserved.

Neonatal circulatory failure due to acute hypertensive crisis: clinical and echocardiographic clues.

PubMed

Louw, Jacoba; Brown, Stephen; Thewissen, Liesbeth; Smits, Anne; Eyskens, Benedicte; Heying, Ruth; Cools, Bjorn; Levtchenko, Elena; Allegaert, Karel; Gewillig, Marc

2013-04-01

Circulatory failure due to acute arterial hypertension in the neonatal period is rare. This study was undertaken to assess the clinical and echocardiographic manifestations of circulatory failure resulting from acute neonatal hypertensive crisis. Neonatal and cardiology databases from 2007 to 2010 were reviewed. An established diagnosis of circulatory failure due to neonatal hypertension before the age of 14 days was required for inclusion. Six patients were identified. Five patients presented with circulatory failure due to an acute hypertensive crisis. The median age at presentation was 8.5 days (range: 6.0-11.0) with a median body weight of 3.58 kg (range: 0.86-4.70). Echocardiography demonstrated mild left ventricular dysfunction [median shortening fraction (SF) 25%, range 10-30] and mild aortic regurgitation in 83% (5/6) of patients. One patient with left ventricular dysfunction (SF = 17%) had a large apical thrombus. Two patients were hypotensive, and hypertension only became evident after restoration of cardiac output. Administration of intravenous milrinone was successful, with rapid improvement of the clinical condition. Left ventricular function normalised in all survivors. Early neonatal circulatory collapse due to arterial hypertension is a rare but potentially life-threatening condition. At presentation, hypotension, especially in the presence of a dysfunctional left ventricle, does not exclude a hypertensive crisis being the cause of circulatory failure. The echocardiographic presence of mild aortic regurgitation combined with left ventricular hypocontractility in a structurally normal heart should alert the physician to the presence of underlying hypertension.

Attrition reactor system

DOEpatents

Scott, C.D.; Davison, B.H.

1993-09-28

A reactor vessel for reacting a solid particulate with a liquid reactant has a centrifugal pump in circulatory flow communication with the reactor vessel for providing particulate attrition, resulting in additional fresh surface where the reaction can occur. 2 figures.

Intensive care of the neonatal foal.

PubMed

Koterba, A M; Drummond, W H; Kosch, P

1985-04-01

The basic concepts of diagnosis and treatment in the abnormal neonatal foal are presented. Methods of restraint, sedation, and general nursing care are discussed, as well as more specific techniques of respiratory and circulatory system support.

Genetics Home Reference: arterial tortuosity syndrome

MedlinePlus

... tortuosity syndrome is a disorder that affects connective tissue. Connective tissue provides strength and flexibility to structures throughout the ... outside the circulatory system are caused by abnormal connective tissue in other parts of the body. These features ...

[Non-medical therapy in heart failure: instrumental treatment and cardiac transplantation].

PubMed

Leprince, Pascal

2010-09-20

Circulatory support devices and cardiac transplantation are closely interlinked and are the treatment of severe heart failure refractory to medical therapy. In acute situation, ECMO allows stabilization of unstable hemodynamic situation related to cardiogenic shock. In patients who require longer term support, the use of continuous flow pumps is associated with better survival and better quality of life. Those pumps can be used either as a bridge to transplantation or as a bridge to recovery but also as destination therapy. Early implantation before occurrence of severe right heart failure allows preferential use of LVAD. Approximately 350 cardiac transplantations are performed every year in France. Indication in based on several criteria appreciating the severity of functional impairment. Contra-indications have to be discussed case by case, and chronologic age should not be a too rigid limit. High urgency list allows transplanting the sickest patients in priority. Conditional half-life in patients surviving the first year post transplantation is 12 years. Mechanical circulatory support and cardiac transplantation should be used as complementary treatment of severe heart failure in order to avoid progressive but sometime irreversible deterioration of patients with chronic heart failure.

CHF: circulatory homeostasis gone awry.

PubMed

Weber, Karl T; Burlew, Brad S; Davis, Richard C; Newman, Kevin P; D'Cruz, Ivan A; Hawkins, Ralph G; Wall, Barry M; Parker, Robert B

2002-01-01

The role of the renin-angiotensin-aldosterone system (RAAS) is integral to salt and water retention, particularly by the kidneys. Over time, positive sodium balance leads first to intra- and then to extravascular volume expansion, with subsequent symptomatic heart failure. This report examines the role of the RAAS in regulating a less well recognized component essential to circulatory homeostasis--central blood volume. The regulation of central blood volume draws on integrative cardiorenal physiology and a key role played by the RAAS in its regulation. In presenting insights into the role of the RAAS in regulating central blood volume, this review also addresses other sodium-retaining states with a predisposition to edema formation, such as cirrhosis and nephrosis. (c)2002 CHF, Inc

Occluder closing behavior: a key factor in mechanical heart valve cavitation.

PubMed

Wu, Z J; Wang, Y; Hwang, N H

1994-04-01

A laser sweeping technique developed in this laboratory was found to be capable of monitoring the leaflet closing motion with microsecond precision. The leaflet closing velocity was measured inside the last three degrees before impact. Mechanical heart valve (MHV) leaflets were observed to close with a three-phase motion; the approaching phase, the decelerating phase, and the rebound phase, all of which take place within one to two milliseconds. The leaflet closing behavior depends mainly on the leaflet design and the hinge mechanism. Bileaflet and monoleaflet types of mechanical heart valves were tested in the mitral position in a physiologic mock circulatory flow loop, which incorporated a computer-controlled magnetic drive and an adjustable afterload system. The test loop was tuned to produce physiologic ventricular and aortic pressure wave forms at 70-120 beats/min, with the maximum ventricular dp/dt varying between 1500-5600 mmHg/sec. The experiments were conducted by controlling the cardiac output at a constant level between 2.0-9.0 liters/min. The measured time-displacement curve of each tested MHV leaflet and its geometry were taken as the input for computation of the squeeze flow field in the narrow gap space between the approaching leaflet and the valve housing. The results indicated rapid build-up of both the pressure and velocity in the gap field within microsecs before the impact. The pressure build-up in the gap space is apparently responsible for the leaflet deceleration before the impact. When the concurrent water hammer pressure reduction at closure was combined with the high energy squeeze jet ejected from the gap space, there were strong indications of the environment which favors micro cavitation inceptions in certain types of MHV.

Development of an in-vitro circulatory system with known resistance and capacitance

NASA Technical Reports Server (NTRS)

Offerdahl, C. D.; Schaub, J. D.; Koenig, S. C.; Swope, R. D.; Ewert, D. L.; Convertino, V. A. (Principal Investigator)

1996-01-01

An in-vitro (hydrodynamic) model of the circulatory system was developed. The model consisted of a pump, compliant tubing, and valves for resistance. The model is used to simulate aortic pressure and flow. These parameters were measured using a Konigsburg Pressure transducer and a Triton ART2 flow probe. In addition, venous pressure and flow were measured on the downstream side of the resistance. The system has a known compliance and resistance. Steady and pulsatile flow tests were conducted to determine the resistance of the model. A static compliance test was used to determine the compliance of the system. The aortic pressure and flow obtained from the hydrodynamic model will be used to test the accuracy of parameter estimation models such as the 2-element and 4-element Windkessel models and the 3-element Westkessel model. Verifying analytical models used in determining total peripheral resistance (TPR) and systemic arterial compliance (SAC) is important because it provides insight into hemodynamic parameters that indicate baroreceptor responsiveness to situations such as changes in gravitational acceleration.

Donations After Circulatory Death in Liver Transplant

PubMed Central

Eren, Emre A.; Latchana, Nicholas; Beal, Eliza; Hayes, Don; Whitson, Bryan; Black, Sylvester M.

2017-01-01

The supply of liver grafts for treatment of end-stage liver disease continues to fall short of ongoing demands. Currently, most liver transplants originate from donations after brain death. Enhanced utilization of the present resources is prudent to address the needs of the population. Donation after circulatory or cardiac death is a mechanism whereby the availability of organs can be expanded. Donations after circulatory death pose unique challenges given their exposure to warm ischemia. Technical principles of donations after circulatory death procurement and pertinent studies investigating patient outcomes, graft outcomes, and complications are highlighted in this review. We also review associated risk factors to suggest potential avenues to achieve improved outcomes and reduced complications. Future considerations and alternative techniques of organ preservation are discussed, which may suggest novel strategies to enhance preservation and donor expansion through the use of marginal donors. Ultimately, without effective measures to bolster organ supply, donations after circulatory death should remain a consideration; however, an understanding of inherent risks and limitations is necessary. PMID:27733105

Donations After Circulatory Death in Liver Transplant.

PubMed

Eren, Emre A; Latchana, Nicholas; Beal, Eliza; Hayes, Don; Whitson, Bryan; Black, Sylvester M

2016-10-01

The supply of liver grafts for treatment of end-stage liver disease continues to fall short of ongoing demands. Currently, most liver transplants originate from donations after brain death. Enhanced utilization of the present resources is prudent to address the needs of the population. Donation after circulatory or cardiac death is a mechanism whereby the availability of organs can be expanded. Donations after circulatory death pose unique challenges given their exposure to warm ischemia. Technical principles of donations after circulatory death procurement and pertinent studies investigating patient outcomes, graft outcomes, and complications are highlighted in this review. We also review associated risk factors to suggest potential avenues to achieve improved outcomes and reduced complications. Future considerations and alternative techniques of organ preservation are discussed, which may suggest novel strategies to enhance preservation and donor expansion through the use of marginal donors. Ultimately, without effective measures to bolster organ supply, donations after circulatory death should remain a consideration; however, an understanding of inherent risks and limitations is necessary.

Generation of OH Radical by Ultrasonic Irradiation in Batch and Circulatory Reactor

NASA Astrophysics Data System (ADS)

Fang, Yu; Shimizu, Sayaka; Yamamoto, Takuya; Komarov, Sergey

2018-03-01

Ultrasonic technology has been widely investigated in the past as one of the advance oxidation processes to treat wastewater, in this process acoustic cavitation causes generation of OH radical, which play a vital role in improving the treatment efficiency. In this study, OH radical formation rate was measured in batch and circulatory reactor by using Weissler reaction at various ultrasound output power. It is found that the generation rate in batch reactor is higher than that in circulatory reactor at the same output power. The generation rate tended to be slower when output power exceeds 137W. The optimum condition for circulatory reactor was found to be 137W output and 4L/min flow rate. Results of aluminum foil erosion test revealed a strong dependence of cavitation zone length on the ultrasound output power. This is assumed to be one of the reasons why the generation rate of HO radicals becomes slower at higher output power in circulatory reactor.

Is moderate hypothermic circulatory arrest with selective antegrade cerebral perfusion superior to deep hypothermic circulatory arrest in elective aortic arch surgery?

PubMed

Poon, Shi Sum; Estrera, Anthony; Oo, Aung; Field, Mark

2016-09-01

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether moderate hypothermia circulatory arrest with selective antegrade cerebral perfusion (SACP) is more beneficial than deep hypothermic circulatory arrest in elective aortic arch surgery. Altogether, 1028 papers were found using the reported search, of which 6 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. There were four retrospective observational studies, one prospective randomized controlled trial and one meta-analysis study. There were no local or neuromuscular complications related to axillary arterial cannulation reported. In the elective setting, four studies showed that the in-hospital mortality for moderate hypothermia is consistently low, ranging from 1.0 to 4.3%. In a large series of hemiarch replacement comparing 682 cases of deep hypothermia with 94 cases of moderate hypothermia with SACP, 20 cases (2.8%) of permanent neurological deficit were reported, compared to 3 cases (3.2%) in moderate hypothermia. Three observational studies and a meta-analysis study did not identify an increased risk of postoperative renal failure and dialysis following either deep or moderate hypothermia although a higher incidence of stroke was reported in the meta-analysis study with deep hypothermia (12.7 vs 7.3%). Longer cardiopulmonary bypass time and circulatory arrest time were reported in four studies for deep hypothermia, suggesting an increased time required for systemic cooling and rewarming in that group. Overall, these findings suggested that in elective aortic arch surgery, moderate hypothermia with selective antegrade cerebral perfusion adapted to the duration of circulatory arrest can be performed safely with acceptable mortality and morbidity outcomes. The risk of spinal cord and visceral organ complications is low with the use of this cerebral adjunct. Current studies did not identify an advantage in terms of postoperative bleeding when compared with deep hypothermia. The moderate hypothermia strategy reduced operative time without increasing the mortality and morbidity of surgery. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Long-term exposure to ambient PM2.5 associated with fall-related injury in six low- and middle-income countries.

PubMed

Guo, Yanfei; Lin, Hualiang; Shi, Yan; Zheng, Yang; Li, Xing; Xiao, Jianpeng; Liu, Tao; Zeng, Weilin; Vaughn, Michael G; Cummings-Vaughn, Lenise A; Nelson, Erik J; Qian, Zhengmin Min; Ma, Wenjun; Wu, Fan

2018-06-01

Exposure to ambient air pollution has been linked with adverse health outcomes of the circulatory and nervous systems. Given that falls are closely related to circulatory and nervous health, we hypothesize that air pollution may adversely affect fall-related injury. We employed Wave 1 data from 36,662 participants aged ≥50 years in WHO's Study on Global AGEing and Adult Health in six low- and middle-income countries. Ambient annual concentration of PM 2.5 was estimated using satellite data. A three-level logistic regression model was applied to examine the long-term association between ambient PM 2.5 and the prevalence of fall-related injury, and associated disease burden, as well as the potential effect modification of consumption of fruit and vegetables. Ambient PM 2.5 was found to be significantly associated with the risk of fall-related injury. Each 10 μg/m 3 increase corresponded to 18% (OR = 1.18, 95% CI: 1.09, 1.28) increase in fall-related injury after adjusting for various covariates. The association was relatively stronger among participants with lower consumption of fruit (OR = 1.22, 95% CI: 1.12, 1.33) than higher consumption (OR = 1.06, 95% CI: 0.92, 1.23), and among those with lower vegetable consumption (OR = 1.18, 95% CI: 1.08, 1.28) than higher consumption (OR = 1.08, 95% CI: 0.91, 1.27). Our study suggests that ambient PM 2.5 may be one risk factor for fall-related injury and that higher consumption of fruit and vegetables could alleviate this effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clustering and Profiling Students According to Their Interactions with an Intelligent Tutoring System Fostering Self-Regulated Learning

ERIC Educational Resources Information Center

Bouchet, Francois; Harley, Jason M.; Trevors, Gregory J.; Azevedo, Roger

2013-01-01

In this paper, we present the results obtained using a clustering algorithm (Expectation-Maximization) on data collected from 106 college students learning about the circulatory system with MetaTutor, an agent-based Intelligent Tutoring System (ITS) designed to foster self-regulated learning (SRL). The three extracted clusters were validated and…

[The brain and cytokines - the mutual origin of depression, obesity and cardiovascular diseases?].

PubMed

Ufnal, Marcin; Wolynczyk-Gmaj, Dorota

2011-04-19

Accumulating evidence points to a pivotal role of the brain in the regulation of the circulatory system and energy balance. It has also been found that common civilization diseases such as depression, obesity, hypertension, myocardial infarction or heart failure are accompanied by an increase in concentration of inflammatory mediators in the blood, cerebrospinal fluid and various tissues. Recent studies have revealed that inflammatory mediators that are synthesized peripherally or in the brain may affect the nervous regulation of animal body systems. For example, it has been found that non-specific pro-inflammatory stimuli as well as treatment with several cytokines may cause depressive behavior, disturbances in energy balance and alterations in the circulatory system. On the other hand, knockout of genes for pro-inflammatory cytokines or administration of anti-inflammatory mediators may normalize the pathological changes. In the present manuscript we will review studies that imply the common neuroinflammatory pathogenesis of cardiovascular diseases, depression and energy balance disorders.

Long-term Mechanical Circulatory Support System reliability recommendation by the National Clinical Trial Initiative subcommittee.

PubMed

Lee, James

2009-01-01

The Long-Term Mechanical Circulatory Support (MCS) System Reliability Recommendation was published in the American Society for Artificial Internal Organs (ASAIO) Journal and the Annals of Thoracic Surgery in 1998. At that time, it was stated that the document would be periodically reviewed to assess its timeliness and appropriateness within 5 years. Given the wealth of clinical experience in MCS systems, a new recommendation has been drafted by consensus of a group of representatives from the medical community, academia, industry, and government. The new recommendation describes a reliability test methodology and provides detailed reliability recommendations. In addition, the new recommendation provides additional information and clinical data in appendices that are intended to assist the reliability test engineer in the development of a reliability test that is expected to give improved predictions of clinical reliability compared with past test methods. The appendices are available for download at the ASAIO journal web site at www.asaiojournal.com.

Cerebral activation of mitogen-activated protein kinases after circulatory arrest and low flow cardiopulmonary bypass.

PubMed

Aharon, Alon S; Mulloy, Matthew R; Drinkwater, Davis C; Lao, Oliver B; Johnson, Mahlon D; Thunder, Megan; Yu, Chang; Chang, Paul

2004-11-01

Mitogen-activated protein kinases (MAPK) are important intermediates in the signal transduction pathways involved in neuronal dysfunction following cerebral ischemia-reperfusion injury. One subfamily, extracellular regulated kinase 1/2, has been heavily implicated in the pathogenesis of post-ischemic neuronal damage. However, the contribution of extracellular regulated kinase 1/2 to neuronal damage following deep hypothermic circulatory arrest and low flow cardiopulmonary bypass is unknown. We attempted to correlate the extent of neuronal damage present following deep hypothermic circulatory arrest and low flow cardiopulmonary bypass with phosphorylated extracellular regulated kinase 1/2 expression in the cerebral vascular endothelium. Piglets underwent normal flow cardiopulmonary bypass (n=4) deep hypothermic circulatory arrest (n=6) and low flow cardiopulmonary bypass (n=5). Brains were harvested following 24 h of post-cardiopulmonary bypass recovery. Cerebral cortical watershed zones, hippocampus, basal ganglia, thalamus, cerebellum, mesencephalon, pons and medulla were evaluated using hematoxylin and eosin staining. A section of ischemic cortex was evaluated by immunohistochemistry with rabbit polyclonal antibodies against phosphorylated extracellular regulated kinase 1/2. Compared to cardiopulmonary bypass controls, the deep hypothermic circulatory arrest and low flow cardiopulmonary bypass piglets exhibited diffuse ischemic changes with overlapping severity and distribution. Significant neuronal damage occurred in the frontal watershed zones and basal ganglia of the deep hypothermic circulatory arrest group (P<0.05). No detectable phosphorylated extracellular regulated kinase 1/2 immunoreactivity was found in the cardiopulmonary bypass controls; however, ERK 1/2 immunoreactivity was present in the cerebral vascular endothelium of the deep hypothermic circulatory arrest and low flow cardiopulmonary bypass groups. Our results indicate that phosphorylated extracellular regulated kinase 1/2 may play a prominent role in early cerebral ischemia-reperfusion injury and endothelial dysfunction. The pharmacologic inhibition of extracellular regulated kinase 1/2 represents a new and exciting opportunity for the modulation of cerebral tolerance to low flow cardiopulmonary bypass and deep hypothermic circulatory arrest.

Manipulation of sarcoplasmic reticulum Ca2+ release in heart failure through mechanical intervention

PubMed Central

Ibrahim, Michael; Nader, Anas; Yacoub, Magdi H; Terracciano, Cesare

2015-01-01

Left ventricular assist devices (LVADs) were developed as a means of temporary circulatory support, but the mechanical unloading they offer also results in significant reverse remodelling. In selected patients, these improvements are sufficient to allow ultimate device explantation without requiring transplantation; this represents a fundamental shift in our understanding of heart failure. Like heart failure itself, LVADs influence multiple biological systems. The transverse tubules are a system of membrane invaginations in ventricular cardiomyocytes which allow rapid propagation of the action potential throughout the cell. Through their dense concentration of L-type Ca2+ channels in close proximity to intracellular ryanodine receptors, the t-tubules enable synchronous Ca2+ release throughout the cell. The t-tubules’ structure appears to be specifically regulated by mechanical load, such that either the overload of heart failure (or the spontaneously hypertensive rat model) or the profound unloading in a chronically unloaded heart result in impaired t-tubule structure, with ineffective Ca2+ release. While there are multiple molecular pathways which underpin t-tubule regulation, Telethonin (Tcap) appears to be important in regulating the effect of altered loading on the t-tubule system. PMID:25922157

Design analysis and performance assessment of hybrid magnetic bearings for a rotary centrifugal blood pump.

PubMed

Ren, Zhaohui; Jahanmir, Said; Heshmat, Hooshang; Hunsberger, Andrew Z; Walton, James F

2009-01-01

A hybrid magnetic bearing system was designed for a rotary centrifugal blood pump being developed to provide long-term circulatory support for heart failure patients. This design consists of two compact bearings to suspend the rotor in five degrees-of-freedom with single axis active control. Permanent magnets are used to provide passive radial support and electromagnets to maintain axial stability of the rotor. Characteristics of the passive radial and active thrust magnetic bearing system were evaluated by the electromagnetic finite element analysis. A proportional-integral-derivative controller with force balance algorithm was implemented for closed loop control of the magnetic thrust bearing. The control position is continuously adjusted based on the electrical energy in the bearing coils, and thus passive magnetic forces carry static thrust loads to minimize the bearing current. Performance of the magnetic bearing system with associated control algorithm was evaluated at different operating conditions. The bearing current was significantly reduced with the force balance control method and the power consumption was below 0.5 W under various thrust loads. The bearing parameters predicted by the analysis were validated by the experimental data.

User's instructions for the whole-body algorithms

NASA Technical Reports Server (NTRS)

Grounds, D. J.; Fitzjerrell, D. G.; Leonard, J. I.; Marks, V. J.

1975-01-01

The design of an algorithm that provides for the simulation of long and short term biological stresses is reported. The physiological responses of models representing circulatory, respiratory, cardiovascular, and thermoregulatory systems during space flight simulation are described.

Comparative systemic toxicity of ropivacaine and bupivacaine in nonpregnant and pregnant ewes.

PubMed

Santos, A C; Arthur, G R; Wlody, D; De Armas, P; Morishima, H O; Finster, M

1995-03-01

Ropivacaine is a new amide local anesthetic, having therapeutic properties similar to those of bupivacaine but with a wider margin of safety. Bupivacaine is probably the most commonly used drug in obstetric epidural analgesia, even though laboratory studies have suggested that pregnancy increases the cardiotoxicity of bupivacaine but not of other local anesthetics. The current study was designed to reevaluate, in a random and blinded fashion, the systemic toxicity of bupivacaine and ropivacaine in nonpregnant and pregnant sheep. Chronically prepared nonpregnant and pregnant ewes were randomized to receive an intravenous infusion of ropivacaine or bupivacaine at a constant rate of 0.5 mg.kg-1.min-1 until circulatory collapse. The investigators were blinded to the identity of local anesthetic. Heart rate, arterial blood pressure, and cardiac rhythm were monitored throughout the study. Arterial blood samples were obtained before infusion and at the onset of toxic manifestations, which appeared in the following sequence: convulsions, hypotension, apnea, and circulatory collapse. Serum drug concentrations and protein binding were determined. Blood pH and gas tensions were measured. There were no significant differences between non-pregnant and pregnant animals in the doses or serum concentrations of either drug required to elicit toxic manifestations. In nonpregnant animals, similar doses and serum concentrations of ropivacaine and bupivacaine were associated with the onset of convulsions and circulatory collapse. In pregnant ewes, greater doses of ropivacaine as compared to bupivacaine were required to produce convulsions (7.5 +/- 0.5 vs. 5.0 +/- 0.6 mg.kg-1) and circulatory collapse (12.9 +/- 0.8 vs. 8.5 +/- 1.2 mg.kg-1). The corresponding serum concentrations of ropivacaine were similar to those of bupivacaine. Pregnancy did not affect the serum protein binding of either drug. The proportion of animals manifesting a malignant ventricular arrhythmia as the terminal event was similar among all groups. The systemic toxicity of ropivacaine or bupivacaine is not enhanced by gestation in sheep. This is in contrast to an earlier study in which the cardiotoxicity of bupivacaine was enhanced during ovine pregnancy. Greater doses of ropivacaine, as compared to bupivacaine, are needed to produce toxic manifestations in pregnant animals.

Automation of a portable extracorporeal circulatory support system with adaptive fuzzy controllers.

PubMed

Mendoza García, A; Krane, M; Baumgartner, B; Sprunk, N; Schreiber, U; Eichhorn, S; Lange, R; Knoll, A

2014-08-01

The presented work relates to the procedure followed for the automation of a portable extracorporeal circulatory support system. Such a device may help increase the chances of survival after suffering from cardiogenic shock outside the hospital, additionally a controller can provide of optimal organ perfusion, while reducing the workload of the operator. Animal experiments were carried out for the acquisition of haemodynamic behaviour of the body under extracorporeal circulation. A mathematical model was constructed based on the experimental data, including a cardiovascular model, gas exchange and the administration of medication. As the base of the controller fuzzy logic was used allowing the easy integration of knowledge from trained perfusionists, an adaptive mechanism was included to adapt to the patient's individual response. Initial simulations show the effectiveness of the controller and the improvements of perfusion after adaptation. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Work history and mortality risks in 90,268 US radiological technologists.

PubMed

Liu, Jason J; Freedman, D Michal; Little, Mark P; Doody, Michele M; Alexander, Bruce H; Kitahara, Cari M; Lee, Terrence; Rajaraman, Preetha; Miller, Jeremy S; Kampa, Diane M; Simon, Steven L; Preston, Dale L; Linet, Martha S

2014-12-01

There have been few studies of work history and mortality risks in medical radiation workers. We expanded by 11 years and more outcomes our previous study of mortality risks and work history, a proxy for radiation exposure. Using Cox proportional hazards models, we estimated mortality risks according to questionnaire work history responses from 1983 to 1989 through 2008 by 90,268 US radiological technologists. We controlled for potential confounding by age, birth year, smoking history, body mass index, race and gender. There were 9566 deaths (3329 cancer and 3020 circulatory system diseases). Mortality risks increased significantly with earlier year began working for female breast (p trend=0.01) and stomach cancers (p trend=0.01), ischaemic heart (p trend=0.03) and cerebrovascular diseases (p trend=0.02). The significant trend with earlier year first worked was strongly apparent for breast cancer during baseline through 1997, but not 1998-2008. Risks were similar in the two periods for circulatory diseases. Radiological technologists working ≥5 years before 1950 had elevated mortality from breast cancer (HR=2.05, 95% CI 1.27 to 3.32), leukaemia (HR=2.57, 95% CI 0.96 to 6.68), ischaemic heart disease (HR=1.13, 95% CI 0.96 to 1.33) and cerebrovascular disease (HR=1.28, 95% CI 0.97 to 1.69). No other work history factors were consistently associated with mortality risks from specific cancers or circulatory diseases, or other conditions. Radiological technologists who began working in early periods and for more years before 1950 had increased mortality from a few cancers and some circulatory system diseases, likely reflecting higher occupational radiation exposures in the earlier years. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The closing behavior of mechanical aortic heart valve prostheses.

PubMed

Lu, Po-Chien; Liu, Jia-Shing; Huang, Ren-Hong; Lo, Chi-Wen; Lai, Ho-Cheng; Hwang, Ned H C

2004-01-01

Mechanical artificial heart valves rely on reverse flow to close their leaflets. This mechanism creates regurgitation and water hammer effects that may form cavitations, damage blood cells, and cause thromboembolism. This study analyzes closing mechanisms of monoleaflet (Medtronic Hall 27), bileaflet (Carbo-Medics 27; St. Jude Medical 27; Duromedics 29), and trileaflet valves in a circulatory mock loop, including an aortic root with three sinuses. Downstream flow field velocity was measured via digital particle image velocimetry (DPIV). A high speed camera (PIVCAM 10-30 CCD video camera) tracked leaflet movement at 1000 frames/s. All valves open in 40-50 msec, but monoleaflet and bileaflet valves close in much less time (< 35 msec) than the trileaflet valve (>75 msec). During acceleration phase of systole, the monoleaflet forms a major and minor flow, the bileaflet has three jet flows, and the trileaflet produces a single central flow like physiologic valves. In deceleration phase, the aortic sinus vortices hinder monoleaflet and bileaflet valve closure until reverse flows and high negative transvalvular pressure push the leaflets rapidly for a hard closure. Conversely, the vortices help close the trileaflet valve more softly, probably causing less damage, lessening back flow, and providing a washing effect that may prevent thrombosis formation.

Dendrimer brain uptake and targeted therapy for brain injury in a large animal model of hypothermic circulatory arrest.

PubMed

Mishra, Manoj K; Beaty, Claude A; Lesniak, Wojciech G; Kambhampati, Siva P; Zhang, Fan; Wilson, Mary A; Blue, Mary E; Troncoso, Juan C; Kannan, Sujatha; Johnston, Michael V; Baumgartner, William A; Kannan, Rangaramanujam M

2014-03-25

Treatment of brain injury following circulatory arrest is a challenging health issue with no viable therapeutic options. Based on studies in a clinically relevant large animal (canine) model of hypothermic circulatory arrest (HCA)-induced brain injury, neuroinflammation and excitotoxicity have been identified as key players in mediating the brain injury after HCA. Therapy with large doses of valproic acid (VPA) showed some neuroprotection but was associated with adverse side effects. For the first time in a large animal model, we explored whether systemically administered polyamidoamine (PAMAM) dendrimers could be effective in reaching target cells in the brain and deliver therapeutics. We showed that, upon systemic administration, hydroxyl-terminated PAMAM dendrimers are taken up in the brain of injured animals and selectively localize in the injured neurons and microglia in the brain. The biodistribution in other major organs was similar to that seen in small animal models. We studied systemic dendrimer-drug combination therapy with two clinically approved drugs, N-acetyl cysteine (NAC) (attenuating neuroinflammation) and valproic acid (attenuating excitotoxicity), building on positive outcomes in a rabbit model of perinatal brain injury. We prepared and characterized dendrimer-NAC (D-NAC) and dendrimer-VPA (D-VPA) conjugates in multigram quantities. A glutathione-sensitive linker to enable for fast intracellular release. In preliminary efficacy studies, combination therapy with D-NAC and D-VPA showed promise in this large animal model, producing 24 h neurological deficit score improvements comparable to high dose combination therapy with VPA and NAC, or free VPA, but at one-tenth the dose, while significantly reducing the adverse side effects. Since adverse side effects of drugs are exaggerated in HCA, the reduced side effects with dendrimer conjugates and suggestions of neuroprotection offer promise for these nanoscale drug delivery systems.

Dendrimer Brain Uptake and Targeted Therapy for Brain Injury in a Large Animal Model of Hypothermic Circulatory Arrest

PubMed Central

2015-01-01

Treatment of brain injury following circulatory arrest is a challenging health issue with no viable therapeutic options. Based on studies in a clinically relevant large animal (canine) model of hypothermic circulatory arrest (HCA)-induced brain injury, neuroinflammation and excitotoxicity have been identified as key players in mediating the brain injury after HCA. Therapy with large doses of valproic acid (VPA) showed some neuroprotection but was associated with adverse side effects. For the first time in a large animal model, we explored whether systemically administered polyamidoamine (PAMAM) dendrimers could be effective in reaching target cells in the brain and deliver therapeutics. We showed that, upon systemic administration, hydroxyl-terminated PAMAM dendrimers are taken up in the brain of injured animals and selectively localize in the injured neurons and microglia in the brain. The biodistribution in other major organs was similar to that seen in small animal models. We studied systemic dendrimer–drug combination therapy with two clinically approved drugs, N-acetyl cysteine (NAC) (attenuating neuroinflammation) and valproic acid (attenuating excitotoxicity), building on positive outcomes in a rabbit model of perinatal brain injury. We prepared and characterized dendrimer-NAC (D-NAC) and dendrimer-VPA (D-VPA) conjugates in multigram quantities. A glutathione-sensitive linker to enable for fast intracellular release. In preliminary efficacy studies, combination therapy with D-NAC and D-VPA showed promise in this large animal model, producing 24 h neurological deficit score improvements comparable to high dose combination therapy with VPA and NAC, or free VPA, but at one-tenth the dose, while significantly reducing the adverse side effects. Since adverse side effects of drugs are exaggerated in HCA, the reduced side effects with dendrimer conjugates and suggestions of neuroprotection offer promise for these nanoscale drug delivery systems. PMID:24499315

Changes of circulatory and nervous diseases mortality patterns during periods of exceptional solar events

NASA Astrophysics Data System (ADS)

Podolska, Katerina

2017-04-01

The paper contains a statistical analysis of exceptional solar events and daily numbers of deaths from diseases from ICD-10 group VI. Diseases of the nervous system, group IX. Diseases of the circulatory system, and overall daily numbers of deaths in the Czech Republic. It is demonstrated that neurological diseases exhibit greater instability during the period of rising and falling solar activity. Specifically, we study the daily number of deaths separately for both sexes at the age groups under 39 and 40+ during the Solar Cycles No. 23 and No. 24. We focus mainly on exceptional solar events such as a "Bastille Day event" on July 14, 2000 (class X5), "Halloween solar storm" on October 28, 2003 (class X17), and events on January 7, 1997, April 2, 2000 (class X20), or September 7, 2005 (class X15). Special attention is given to "St. Patrick's Day storm" on March 17, 2015, the strongest geomagnetic storm of the Solar Cycle No. 24 that occurred following a coronal mass ejection (CME). We investigate changes in daily numbers of deaths during 1 month before and 1 month after these exceptional solar events. We take specific storm dynamics of geophysical parameters into consideration, and we also apply the results of risky characteristics of expositions by ionospheric and geomagnetic parameters. It is verified that, for diseases of the nervous system, women are generally more sensitive than men. On the contrary, this differences between men and women are not found for diseases of the circulatory system. Our findings suggest that the impact of hazardous space weather conditions on human health depends on the specific course and strength of individual solar storm.

Infection-Induced Interaction between the Mosquito Circulatory and Immune Systems

PubMed Central

King, Jonas G.; Hillyer, Julián F.

2012-01-01

Insects counter infection with innate immune responses that rely on cells called hemocytes. Hemocytes exist in association with the insect's open circulatory system and this mode of existence has likely influenced the organization and control of anti-pathogen immune responses. Previous studies reported that pathogens in the mosquito body cavity (hemocoel) accumulate on the surface of the heart. Using novel cell staining, microdissection and intravital imaging techniques, we investigated the mechanism of pathogen accumulation in the pericardium of the malaria mosquito, Anopheles gambiae, and discovered a novel insect immune tissue, herein named periostial hemocytes, that sequesters pathogens as they flow with the hemolymph. Specifically, we show that there are two types of endocytic cells that flank the heart: periostial hemocytes and pericardial cells. Resident periostial hemocytes engage in the rapid phagocytosis of pathogens, and during the course of a bacterial or Plasmodium infection, circulating hemocytes migrate to the periostial regions where they bind the cardiac musculature and each other, and continue the phagocytosis of invaders. Periostial hemocyte aggregation occurs in a time- and infection dose-dependent manner, and once this immune process is triggered, the number of periostial hemocytes remains elevated for the lifetime of the mosquito. Finally, the soluble immune elicitors peptidoglycan and β-1,3-glucan also induce periostial hemocyte aggregation, indicating that this is a generalized and basal immune response that is induced by diverse immune stimuli. These data describe a novel insect cellular immune response that fundamentally relies on the physiological interaction between the insect circulatory and immune systems. PMID:23209421

Public funding for medical research in relation to the burden of disease caused by cardiovascular diseases and neoplasms in Germany.

PubMed

Krone, Manuel; Dufner, Vera; Wagner, Martin; Gelbrich, Götz; Ertl, Georg; Heuschmann, Peter U

2018-04-13

Public funding for medical research in Germany is primarily provided by the German Research Foundation (DFG) and the Federal Ministry of Education and Research (BMBF). The aim of this study was to analyze the amount of national public funding for medical research on predominant causes of death in Germany, cardiovascular diseases and neoplasms, in relation to the burden of these diseases in Germany. Three evaluators categorized medical research projects funded by the DFG or BMBF between 2010 and 2012 into the categories "Diseases of the circulatory system" (with subgroups "Ischemic heart diseases", "Heart failure" and "Cerebrovascular diseases") and "Neoplasms". The total amount of public funding by the national agencies was analyzed in relation to the burden of disease for the respective disease condition. Information on national public funding for medical research of 2091 million euros was available; of those, 246.8 million euros (11.8%) were categorized being spent for research on "Neoplasms", 118.4 million euros (5.7%) for research on "Diseases of the circulatory system". This results in 362.08 euros per case of death, 16.58 euros per year of life lost (YLL) and 16.04 euros per disability-adjusted life year (DALY) for "Neoplasms" and in 113.44 euros per case of death, 8.05 euros per YLL and 7.17 euros per DALY for "Diseases of the circulatory system". In Germany, research on cardiovascular diseases receives a lower share of national public funding for medical research compared to oncological research. These results are comparable to other European countries.

Influence of a high-fat diet on gut microbiota, intestinal permeability and metabolic endotoxaemia.

PubMed

Moreira, Ana Paula Boroni; Texeira, Tatiana Fiche Salles; Ferreira, Alessandra Barbosa; Peluzio, Maria do Carmo Gouveia; Alfenas, Rita de Cássia Gonçalves

2012-09-01

Lipopolysaccharide (LPS) may play an important role in chronic diseases through the activation of inflammatory responses. The type of diet consumed is of major concern for the prevention and treatment of these diseases. Evidence from animal and human studies has shown that LPS can diffuse from the gut to the circulatory system in response to the intake of high amounts of fat. The method by which LPS move into the circulatory system is either through direct diffusion due to intestinal paracellular permeability or through absorption by enterocytes during chylomicron secretion. Considering the impact of metabolic diseases on public health and the association between these diseases and the levels of LPS in the circulatory system, this review will mainly discuss the current knowledge about high-fat diets and subclinical inflammation. It will also describe the new evidence that correlates gut microbiota, intestinal permeability and alkaline phosphatase activity with increased blood LPS levels and the biological effects of this increase, such as insulin resistance. Although the majority of the studies published so far have assessed the effects of dietary fat, additional studies are necessary to deepen the understanding of how the amount, the quality and the structure of the fat may affect endotoxaemia. The potential of food combinations to reduce the negative effects of fat intake should also be considered in future studies. In these studies, the effects of flavonoids, prebiotics and probiotics on endotoxaemia should be investigated. Thus, it is essential to identify dietetic strategies capable of minimising endotoxaemia and its postprandial inflammatory effects.

Contrasting patterns of hospital admissions and mortality during heat waves: are deaths from circulatory disease a real excess or an artifact?

PubMed

Mastrangelo, Giuseppe; Hajat, Shakoor; Fadda, Emanuela; Buja, Alessandra; Fedeli, Ugo; Spolaore, Paolo

2006-01-01

In old subjects exposed to extreme high temperature during a heat wave, studies have consistently reported an excess of death from cardio- or cerebro-vascular disease. By contrast, dehydration, heat stroke, acute renal insufficiency, and respiratory disease were the main causes of hospital admission in the two studies carried out in elderly during short spells of hot weather. The excess of circulatory disease reported by mortality studies, but not by morbidity studies, could be explained by the hypothesis that deaths from circulatory disease occur rapidly in isolated people before they reach a hospital. Since the contrasting patterns of hospital admission and mortality during heat waves could also be due to chance (random variation over time and space in the spectrum of diseases induced by extreme heat), and bias (poor quality of diagnosis on death certificate and other artifacts), it should be confirmed by a concurrent study of mortality and morbidity. Many heat-related diseases may be preventable with adequate warning and an appropriate response to heat emergencies, but preventive efforts are complicated by the short time interval that may elapse between high temperatures and death. Therefore, prevention programs must be based around rapid identification of high-risk conditions and persons. The effectiveness of the intervention measures must be formally evaluated. If cardio- and cerebro-vascular diseases are rapidly fatal health outcomes with a short time interval between exposure to high temperature and death, deaths from circulatory disease might be an useful indicator in evaluating the effectiveness of a heat watch/warning system.

76 FR 63928 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-14

... medical professionals. The database is a Web- based server that contains software, which receives data transmitted from the electronics unit, and presents the data for review by medical professionals. FDA intends...

Structures with Reconfigurable Circulatory Systems

DTIC Science & Technology

2008-05-16

chemical groups ( cinnamates , etc.) may be explored as they may result in faster kinetics which will facilitate transition between solid and liquid...Cysteine, an amino acid , is a critical substrate in biosynthesis of proteins, glutathione, taurine sulfate and the exceptionally metabolically active

How Do Students Regulate their Learning of Complex Systems with Hypermedia?.

ERIC Educational Resources Information Center

Azevedo, Roger; Seibert, Diane; Guthrie, John T.; Cromley, Jennifer G.; Wang, Huei-yu; Tron, Myriam

This study examined the role of different goal-setting instructional interventions in facilitating students' shift to more sophisticated mental models of the circulatory system as indicated by both performance and process data. Researchers adopted the information processing model of self-regulated learning of P. Winne and colleagues (1998, 2001)…

The Effects of Restructuring Biology Teaching by a Constructivist Teaching Approach: An Action Research.

ERIC Educational Resources Information Center

Lin, Wan-Ju

This study reports on the improvement of a teacher researcher's teaching practice by adopting a constructivist teaching approach. Four biology units on the nervous system, human circulatory system, evolution, and vertebrate classification were selected to illustrate a model of biology teaching. Data were drawn from student responses to…

Ovarian Stem Cell Nests in Reproduction and Ovarian Aging.

PubMed

Ye, Haifeng; Zheng, Tuochen; Li, Wei; Li, Xiaoyan; Fu, Xinxin; Huang, Yaoqi; Hu, Chuan; Li, Jia; Huang, Jian; Liu, Zhengyv; Zheng, Liping; Zheng, Yuehui

2017-01-01

The fixed primordial follicles pool theory, which monopolized reproductive medicine for more than one hundred years, has been broken by the discovery, successful isolation and establishment of ovarian stem cells. It has brought more hope than ever of increasing the size of primordial follicle pool, improving ovarian function and delaying ovarian consenescence. Traditional view holds that stem cell aging contributes to the senility of body and organs. However, in the process of ovarian aging, the main factor leading to the decline of the reproductive function is the aging and degradation of ovarian stem cell nests, rather than the senescence of ovarian germ cells themselves. Recent studies have found that the immune system and circulatory system are involved in the formation of ovarian germline stem cell niches, as well as regulating the proliferation and differentiation of ovarian germline stem cells through cellular and hormonal signals. Therefore, we can improve ovarian function and delay ovarian aging by improving the immune system and circulatory system, which will provide an updated program for the treatment of premature ovarian failure (POF) and infertility. © 2017 The Author(s). Published by S. Karger AG, Basel.

Accelerated Biofluid Filling in Complex Microfluidic Networks by Vacuum-Pressure Accelerated Movement (V-PAM).

PubMed

Yu, Zeta Tak For; Cheung, Mei Ki; Liu, Shirley Xiaosu; Fu, Jianping

2016-09-01

Rapid fluid transport and exchange are critical operations involved in many microfluidic applications. However, conventional mechanisms used for driving fluid transport in microfluidics, such as micropumping and high pressure, can be inaccurate and difficult for implementation for integrated microfluidics containing control components and closed compartments. Here, a technology has been developed termed Vacuum-Pressure Accelerated Movement (V-PAM) capable of significantly enhancing biofluid transport in complex microfluidic environments containing dead-end channels and closed chambers. Operation of the V-PAM entails a pressurized fluid loading into microfluidic channels where gas confined inside can rapidly be dissipated through permeation through a thin, gas-permeable membrane sandwiched between microfluidic channels and a network of vacuum channels. Effects of different structural and operational parameters of the V-PAM for promoting fluid filling in microfluidic environments have been studied systematically. This work further demonstrates the applicability of V-PAM for rapid filling of temperature-sensitive hydrogels and unprocessed whole blood into complex irregular microfluidic networks such as microfluidic leaf venation patterns and blood circulatory systems. Together, the V-PAM technology provides a promising generic microfluidic tool for advanced fluid control and transport in integrated microfluidics for different microfluidic diagnosis, organs-on-chips, and biomimetic studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wave reflection and transmission in multiply stented blood vessels

NASA Astrophysics Data System (ADS)

Papathanasiou, T. K.; Movchan, A. B.; Bigoni, D.

2017-06-01

Closed circulatory systems display an exquisite balance between vascular elasticity and viscous fluid effects, to induce pulse-smoothing and avoid resonance during the cardiac cycle. Stents in the arterial tree alter this balance through stiffening and because a periodic structure is introduced, capable of interacting with the fluid in a complex way. While the former feature has been investigated, the latter received no attention so far. But periodic structures are the building blocks of metamaterials, known for their `non-natural' behaviour. Thus, the investigation of a stent's periodic microstructure dynamical interactions is crucial to assess possible pathological responses. A one-dimensional fluid-structure interaction model, simple enough to allow an analytical solution for situations of interest involving one or two interacting stents, is introduced. It is determined: (i) whether or not frequency bands exist in which reflected blood pulses are highly increased and (ii) if these bands are close to the characteristic frequencies of arteries and finally, (iii) if the internal structure of the stent can sensibly affect arterial blood dynamics. It is shown that, while the periodic structure of an isolated stent can induce anomalous reflection only in pathological conditions, the presence of two interacting stents is more critical, and high reflection can occur at frequencies not far from the physiological values.

Wave reflection and transmission in multiply stented blood vessels

PubMed Central

Movchan, A. B.

2017-01-01

Closed circulatory systems display an exquisite balance between vascular elasticity and viscous fluid effects, to induce pulse-smoothing and avoid resonance during the cardiac cycle. Stents in the arterial tree alter this balance through stiffening and because a periodic structure is introduced, capable of interacting with the fluid in a complex way. While the former feature has been investigated, the latter received no attention so far. But periodic structures are the building blocks of metamaterials, known for their ‘non-natural’ behaviour. Thus, the investigation of a stent's periodic microstructure dynamical interactions is crucial to assess possible pathological responses. A one-dimensional fluid–structure interaction model, simple enough to allow an analytical solution for situations of interest involving one or two interacting stents, is introduced. It is determined: (i) whether or not frequency bands exist in which reflected blood pulses are highly increased and (ii) if these bands are close to the characteristic frequencies of arteries and finally, (iii) if the internal structure of the stent can sensibly affect arterial blood dynamics. It is shown that, while the periodic structure of an isolated stent can induce anomalous reflection only in pathological conditions, the presence of two interacting stents is more critical, and high reflection can occur at frequencies not far from the physiological values. PMID:28690408

Energy transmission and power sources for mechanical circulatory support devices to achieve total implantability.

PubMed

Wang, Jake X; Smith, Joshua R; Bonde, Pramod

2014-04-01

Left ventricular assist device therapy has radically improved congestive heart failure survival with smaller rotary pumps. The driveline used to power today's left ventricular assist devices, however, continues to be a source of infection, traumatic damage, and rehospitalization. Previous attempts to wirelessly power left ventricular assist devices using transcutaneous energy transfer systems have been limited by restrictions on separation distance and alignment between the transmit and receive coils. Resonant electrical energy transfer allows power delivery at larger distances without compromising safety and efficiency. This review covers the efforts to wirelessly power mechanical circulatory assist devices and the progress made in enhancing their energy sources. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

UPDATE ON PPHN: MECHANISMS AND TREATMENT

PubMed Central

Nair, Jayasree; Lakshminrusimha, Satyan

2013-01-01

Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome of failed circulatory adaptation at birth, seen in about 2/1000 live born infants. While it is mostly seen in term and near term infants, it can be recognized in some premature infants with respiratory distress or bronchopulmonary dysplasia. Most commonly, PPHN is secondary to delayed or impaired relaxation of the pulmonary vasculature associated with diverse neonatal pulmonary pathologies such as meconium aspiration syndrome, congenital diaphragmatic hernia and respiratory distress syndrome. Gentle ventilation strategies, lung recruitment, inhaled nitric oxide and surfactant therapy have improved outcome and reduced the need for extracorporeal membrane oxygenation (ECMO) in PPHN. Newer modalities of treatment discussed in this review include systemic and inhaled vasodilators like sildenafil, prostaglandin E1, prostacyclin and endothelin antagonists. With prompt recognition/treatment and early referral to ECMO centers, the mortality rate for PPHN has significantly decreased. However, the risk of potential neurodevelopmental impairment warrants close follow up after discharge for infants with PPHN. PMID:24580763

Role of Inclined Magnetic Field and Copper Nanoparticles on Peristaltic Flow of Nanofluid through Inclined Annulus: Application of the Clot Model

NASA Astrophysics Data System (ADS)

Shahzadi, Iqra; Nadeem, S.

2017-06-01

A genuine neurotic condition is experienced when some blood constituents accumulate on the wall of the artery get withdrew from the wall, again join the circulatory system and coagulation occur. Role of copper nanoparticles and inclined magnetic field on the peristaltic flow of a nanofluid in an annular region of inclined annulus is investigated. We represent the clot model by considering the small artery as an annulus whose outer tube has a wave of sinusoidal nature and inner tube has a clot on its walls. Lubrication approach is used to simplify the problem. Close form solutions are determined for temperature and velocity profile. Impact of related parameters on pressure rise, pressure gradient, velocity and streamlines are interpreted graphically. Comparison among the pure blood and copper blood is presented and analyzed. One main finding of the considered analysis is that the inclusion of copper nanoparticles enlarges the amplitude of the velocity. Therefore, the considered study plays a dominant role in biomedical applications.

Risk Factors and Outcomes in Transfusion-associated Circulatory Overload

PubMed Central

Murphy, Edward L.; Kwaan, Nicholas; Looney, Mark R.; Gajic, Ognjen; Hubmayr, Rolf D.; Gropper, Michael A.; Koenigsberg, Monique; Wilson, Greg; Matthay, Michael; Bacchetti, Peter; Toy, Pearl

2013-01-01

BACKGROUND Transfusion-associated circulatory overload is characterized by new respiratory distress and hydrostatic pulmonary edema within 6 hours after blood transfusion, but its risk factors and outcomes are poorly characterized. METHODS Using a case control design, we enrolled 83 patients with severe transfusion-associated circulatory overload identified by active surveillance for hypoxemia and 163 transfused controls at the University of California, San Francisco (UCSF) and Mayo Clinic (Rochester, Minn) hospitals. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariable logistic regression, and survival and length of stay were analyzed using proportional hazard models. RESULTS Transfusion-associated circulatory overload was associated with chronic renal failure (OR 27.0; 95% CI, 5.2–143), a past history of heart failure (OR 6.6; 95% CI, 2.1–21), hemorrhagic shock (OR 113; 95% CI, 14.1–903), number of blood products transfused (OR 1.11 per unit; 95% CI, 1.01–1.22), and fluid balance per hour (OR 9.4 per liter; 95% CI, 3.1–28). Patients with transfusion-associated circulatory overload had significantly increased in-hospital mortality (hazard ratio 3.20; 95% CI, 1.23–8.10) after controlling for Acute Physiology and Chronic Health Evaluation-II (APACHE-II) score, and longer hospital and intensive care unit lengths of stay. CONCLUSIONS The risk of transfusion-associated circulatory overload increases with the number of blood products administered and a positive fluid balance, and in patients with pre-existing heart failure and chronic renal failure. These data, if replicated, could be used to construct predictive algorithms for transfusion-associated circulatory overload, and subsequent modifications of transfusion practice might prevent morbidity and mortality associated with this complication. PMID:23357450

Fetal circulatory responses to oxygen lack.

PubMed

Jensen, A; Berger, R

1991-10-01

The knowledge on fetal and neonatal circulatory physiology accumulated by basic scientists and clinicians over the years has contributed considerably to the recent decline of perinatal morbidity and mortality. This review will summarize the peculiarities of the fetal circulation, the distribution of organ blood flow during normoxemia, and that during oxygen lack caused by various experimental perturbations. Furthermore, the relation between oxygen delivery and tissue metabolism during oxygen lack as well as evidence to support a new concept will be presented along with the principal cardiovascular mechanisms involved. Finally, blood flow and oxygen delivery to the principal fetal organs will be examined and discussed in relation to organ function. The fetal circulatory response to hypoxemia and asphyxia is a centralization of blood flow in favour of the brain, heart, and adrenals and at the expense of almost all peripheral organs, particularly of the lungs, carcass, skin and scalp. This response is qualitatively similar but quantitatively different under various experimental conditions. However, at the nadir of severe acute asphyxia the circulatory centralization cannot be maintained. Then there is circulatory decentralization, and the fetus will experience severe brain damage if not expire unless immediate resuscitation occurs. Future work in this field will have to concentrate on the important questions, what factors determine this collapse of circulatory compensating mechanisms in the fetus, how does it relate to neuronal damage, and how can the fetal brain be pharmacologically protected against the adverse effects of asphyxia.

75 FR 7282 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-18

... March 19, 2010, the committee will discuss, make recommendations and vote on a PMA for the REVO MRI Pacemaker System sponsored by Medtronic. The REVO MRI Pacing System is a pacemaker (with a standard pacing indication) that has been specifically designed to be safe for the MRI environment under certain MR scanning...

Computer model of cardiovascular control system responses to exercise

NASA Technical Reports Server (NTRS)

Croston, R. C.; Rummel, J. A.; Kay, F. J.

1973-01-01

Approaches of systems analysis and mathematical modeling together with computer simulation techniques are applied to the cardiovascular system in order to simulate dynamic responses of the system to a range of exercise work loads. A block diagram of the circulatory model is presented, taking into account arterial segments, venous segments, arterio-venous circulation branches, and the heart. A cardiovascular control system model is also discussed together with model test results.

78 FR 55081 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-09

... measurements to a database for review by medical professionals. The database is a Web-based server that... review by medical professionals. FDA intends to make background material available to the public no later...

Biology Notes

ERIC Educational Resources Information Center

School Science Review, 1972

1972-01-01

Short articles on a demonstration of enzyme action, models of mammalian circulatory systems, measuring the height of trees, the ecology of the African amphibian Xenopus under natural conditions in England, experiments with liverwort gemmae, investigations using stick insects, and a culture medium for Paramecium bursaria. (AL)

Hemodynamics: Biophysics for AP Biology

ERIC Educational Resources Information Center

Neulieb, Marilyn Huetten; Neulieb, Robert

1975-01-01

Discusses the physics of fluids flowing through vessels in the context of blood moving in the circulatory system. The method of presentation used is judged suitable for students in an advanced high school science course emphasizing individualized instruction in an interdisciplinary field. (Author/PEB)

Canadian Guidelines for Controlled Pediatric Donation After Circulatory Determination of Death-Summary Report.

PubMed

Weiss, Matthew J; Hornby, Laura; Rochwerg, Bram; van Manen, Michael; Dhanani, Sonny; Sivarajan, V Ben; Appleby, Amber; Bennett, Mary; Buchman, Daniel; Farrell, Catherine; Goldberg, Aviva; Greenberg, Rebecca; Singh, Ram; Nakagawa, Thomas A; Witteman, William; Barter, Jill; Beck, Allon; Coughlin, Kevin; Conradi, Alf; Cupido, Cynthia; Dawson, Rosanne; Dipchand, Anne; Freed, Darren; Hornby, Karen; Langlois, Valerie; Mack, Cheryl; Mahoney, Meagan; Manhas, Deepak; Tomlinson, Christopher; Zavalkoff, Samara; Shemie, Sam D

2017-11-01

Create trustworthy, rigorous, national clinical practice guidelines for the practice of pediatric donation after circulatory determination of death in Canada. We followed a process of clinical practice guideline development based on World Health Organization and Canadian Medical Association methods. This included application of Grading of Recommendations Assessment, Development, and Evaluation methodology. Questions requiring recommendations were generated based on 1) 2006 Canadian donation after circulatory determination of death guidelines (not pediatric specific), 2) a multidisciplinary symposium of national and international pediatric donation after circulatory determination of death leaders, and 3) a scoping review of the pediatric donation after circulatory determination of death literature. Input from these sources drove drafting of actionable questions and Good Practice Statements, as defined by the Grading of Recommendations Assessment, Development, and Evaluation group. We performed additional literature reviews for all actionable questions. Evidence was assessed for quality using Grading of Recommendations Assessment, Development, and Evaluation and then formulated into evidence profiles that informed recommendations through the evidence-to-decision framework. Recommendations were revised through consensus among members of seven topic-specific working groups and finalized during meetings of working group leads and the planning committee. External review was provided by pediatric, critical care, and critical care nursing professional societies and patient partners. We generated 63 Good Practice Statements and seven Grading of Recommendations Assessment, Development, and Evaluation recommendations covering 1) ethics, consent, and withdrawal of life-sustaining therapy, 2) eligibility, 3) withdrawal of life-sustaining therapy practices, 4) ante and postmortem interventions, 5) death determination, 6) neonatal pediatric donation after circulatory determination of death, 7) cardiac and innovative pediatric donation after circulatory determination of death, and 8) implementation. For brevity, 48 Good Practice Statement and truncated justification are included in this summary report. The remaining recommendations, detailed methodology, full Grading of Recommendations Assessment, Development, and Evaluation tables, and expanded justifications are available in the full text report. This process showed that rigorous, transparent clinical practice guideline development is possible in the domain of pediatric deceased donation. Application of these recommendations will increase access to pediatric donation after circulatory determination of death across Canada and may serve as a model for future clinical practice guideline development in deceased donation.

Underuse of medication for circulatory disorders among unmarried women and men in Norway?

PubMed

Kravdal, Øystein; Grundy, Emily

2014-11-24

It is well established that unmarried people have higher mortality from circulatory diseases and higher all-cause mortality than the married, and these marital status differences seem to be increasing. However, much remains to be known about the underlying mechanisms. Our objective was to examine marital status differences in the purchase of medication for circulatory diseases, and risk factors for them, which may indicate underuse of such medication by some marital status groups. Using data from registers covering the entire Norwegian population, we analysed marital status differences in the purchase of medicine for eight circulatory disorders by people aged 50-79 in 2004-2008. These differences were compared with those in circulatory disease mortality during 2004-2007, considered as indicating probable differences in disease burden. The unmarried had 1.4-2.8 times higher mortality from the four types of circulatory diseases considered. However, the never-married in particular purchased less medicine for these diseases, or precursor risk factors of these diseases, primarily because of a low chance of making a first purchase. The picture was more mixed for the divorced and widowed. Both groups purchased less of some of these medicines than the married, but, especially in the case of the widowed, relatively more of other types of medicine. In contrast to the never-married, divorced and widowed people were as least as likely as the married to make a first purchase, but adherence rates thereafter, indicated by continuing purchases, were lower. The most plausible interpretation of the findings is that compared with married people, especially the never-married more often have circulatory disorders that are undiagnosed or for which they for other reasons underuse medication. Inadequate use of these potentially very efficient medicines in such a large population group is a serious public health challenge which needs further investigation. It is possible that marital status differences in use of medicines for circulatory disorders combined with an increasing importance of these medicines have contributed to the widening marital status gap in mortality observed in several countries. This also requires further investigation.

77 FR 66847 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

... cardiac cycle. During diastole, the balloon will inflate, creating a rise in pressure in the aorta, thus..., deflation of the balloon causes a fall in pressure in the aorta, which assists the left ventricle by...

Elementary Hemodynamic Principles Based on Modified Bernoulli's Equation.

ERIC Educational Resources Information Center

Badeer, Henry S.

1985-01-01

Develops and expands basic concepts of Bernoulli's equation as it applies to vascular hemodynamics. Simple models are used to illustrate gravitational potential energy, steady nonturbulent flow, pump-driven streamline flow, and other areas. Relationships to the circulatory system are also discussed. (DH)

Numerical Models of Human Circulatory System under Altered Gravity: Brain Circulation

NASA Technical Reports Server (NTRS)

Kim, Chang Sung; Kiris, Cetin; Kwak, Dochan; David, Tim

2003-01-01

A computational fluid dynamics (CFD) approach is presented to model the blood flow through the human circulatory system under altered gravity conditions. Models required for CFD simulation relevant to major hemodynamic issues are introduced such as non-Newtonian flow models governed by red blood cells, a model for arterial wall motion due to fluid-wall interactions, a vascular bed model for outflow boundary conditions, and a model for auto-regulation mechanism. The three-dimensional unsteady incompressible Navier-Stokes equations coupled with these models are solved iteratively using the pseudocompressibility method and dual time stepping. Moving wall boundary conditions from the first-order fluid-wall interaction model are used to study the influence of arterial wall distensibility on flow patterns and wall shear stresses during the heart pulse. A vascular bed modeling utilizing the analogy with electric circuits is coupled with an auto-regulation algorithm for multiple outflow boundaries. For the treatment of complex geometry, a chimera overset grid technique is adopted to obtain connectivity between arterial branches. For code validation, computed results are compared with experimental data for steady and unsteady non-Newtonian flows. Good agreement is obtained for both cases. In sin-type Gravity Benchmark Problems, gravity source terms are added to the Navier-Stokes equations to study the effect of gravitational variation on the human circulatory system. This computational approach is then applied to localized blood flows through a realistic carotid bifurcation and two Circle of Willis models, one using an idealized geometry and the other model using an anatomical data set. A three- dimensional anatomical Circle of Willis configuration is reconstructed from human-specific magnetic resonance images using an image segmentation method. The blood flow through these Circle of Willis models is simulated to provide means for studying gravitational effects on the brain circulation under auto-regulation.

Dietary (Poly)phenolics in Human Health: Structures, Bioavailability, and Evidence of Protective Effects Against Chronic Diseases

PubMed Central

Del Rio, Daniele; Rodriguez-Mateos, Ana; Spencer, Jeremy P.E.; Tognolini, Massimiliano; Borges, Gina

2013-01-01

Abstract Human intervention trials have provided evidence for protective effects of various (poly)phenol-rich foods against chronic disease, including cardiovascular disease, neurodegeneration, and cancer. While there are considerable data suggesting benefits of (poly)phenol intake, conclusions regarding their preventive potential remain unresolved due to several limitations in existing studies. Bioactivity investigations using cell lines have made an extensive use of both (poly)phenolic aglycones and sugar conjugates, these being the typical forms that exist in planta, at concentrations in the low-μM-to-mM range. However, after ingestion, dietary (poly)phenolics appear in the circulatory system not as the parent compounds, but as phase II metabolites, and their presence in plasma after dietary intake rarely exceeds nM concentrations. Substantial quantities of both the parent compounds and their metabolites pass to the colon where they are degraded by the action of the local microbiota, giving rise principally to small phenolic acid and aromatic catabolites that are absorbed into the circulatory system. This comprehensive review describes the different groups of compounds that have been reported to be involved in human nutrition, their fate in the body as they pass through the gastrointestinal tract and are absorbed into the circulatory system, the evidence of their impact on human chronic diseases, and the possible mechanisms of action through which (poly)phenol metabolites and catabolites may exert these protective actions. It is concluded that better performed in vivo intervention and in vitro mechanistic studies are needed to fully understand how these molecules interact with human physiological and pathological processes. Antioxid. Redox Signal. 18, 1818–1892. PMID:22794138

Effect of decreased gravity on circulation in the rat

NASA Technical Reports Server (NTRS)

Popovic, Vojin P.

1987-01-01

It has been reported that hypokinesia and bed rest induce cardiovascular changes similar to those observed in space flights. Using an animal model that was developed in our laboratory and that was extensively studied and characterized in our laboratory and other laboratories in this country and abroad, we have studied circulatory mechanisms that occur during exposure to hypokinesia (with or without negative tilt) as well as during readaptation to control conditions (free activity). We believe that this study contributes to better understanding of mammalian circulatory mechanisms that operate under 1-g force and will serve to provide control data to be compared with cardiovascular data obtained in conditions of a Space lab. Because survey and anesthesia drastically decrease cardiac output and other circulatory parameters in rats, only unanesthetized rats were used in experiments. Aorta and right atrium of the animals were permanently cannulated fifteen to twenty days before experiments. Arterial and right ventricular blood pressures, cardiac output, cerebral and other regional blood flow, ECG, other cardiovascular parameters, and oxygen consumption were measured with techniques routinely used in our laboratory. Specifically, we undertook the following investigations during the period of three years: (1) A study of circulatory changes (right ventricular pressure, arterial blood pressure, heart rate, cardiac output) during exposure of rats to hypokinetic conditions. Used the head down tilted Holton-Musacchia system in order to compare the results with the results already obtained on unrestrained rats, (2) Humoral changes were investigated in animals exposed to hypokinesia; also, lymphocyte and neutrophil levels in hypokinetic animals (with or without tilt) were determined to ascertain the level of induced stress and possible changes observed in weightless animals, and (3) circulating blood volume was determined during and after hypokinesia.

High-risk medical devices, children and the FDA: regulatory challenges facing pediatric mechanical circulatory support devices.

PubMed

Almond, Christopher S D; Chen, Eric A; Berman, Michael R; Less, Joanne R; Baldwin, J Timothy; Linde-Feucht, Sarah R; Hoke, Tracey R; Pearson, Gail D; Jenkins, Kathy; Duncan, Brian W; Zuckerman, Bram D

2007-01-01

Pediatric mechanical circulatory support is a critical unmet need in the United States. Infant- and child-sized ventricular assist devices are currently being developed largely through federal contracts and grants through the National Heart, Lung, and Blood Institute (NHLBI). Human testing and marketing of high-risk devices for children raises epidemiologic and regulatory issues that will need to be addressed. Leaders from the US Food and Drug Administration (FDA), NHLBI, academic pediatric community, and industry convened in January 2006 for the first FDA Workshop on the Regulatory Process for Pediatric Mechanical Circulatory Support Devices. The purpose was to provide the pediatric community with an overview of the federal regulatory process for high-risk medical devices and to review the challenges specific to the development and regulation of pediatric mechanical circulatory support devices. Pediatric mechanical circulatory support present significant epidemiologic, logistic, and financial challenges to industry, federal regulators, and the pediatric community. Early interactions with the FDA, shared appreciation of challenges, and careful planning will be critical to avoid unnecessary delays in making potentially life-saving devices available for children. Collaborative efforts to address these challenges are warranted.

A Comparative Study of Different Hypothermic Circulatory Arrest Strategies on Aortic Surgery.

ClinicalTrials.gov

2018-03-22

Morality; Hypothermic Circulatory Arrest Time; Aortic-cross Clamping Time; Cardiopulmonary Bypass Time; Operation Time; Re-Thoracotomy; ICU Stay; Mechanical Ventilation Time; Blood Transfusion; Neurological Disorder; Dialysis; Aneurysm; Endoleak; Hospital Stay

Label-free optical lymphangiography: development of an automatic segmentation method applied to optical coherence tomography to visualize lymphatic vessels using Hessian filters

PubMed Central

Yousefi, Siavash; Qin, Jia; Zhi, Zhongwei

2013-01-01

Abstract. Lymphatic vessels are a part of the circulatory system that collect plasma and other substances that have leaked from the capillaries into interstitial fluid (lymph) and transport lymph back to the circulatory system. Since lymph is transparent, lymphatic vessels appear as dark hallow vessel-like regions in optical coherence tomography (OCT) cross sectional images. We propose an automatic method to segment lymphatic vessel lumen from OCT structural cross sections using eigenvalues of Hessian filters. Compared to the existing method based on intensity threshold, Hessian filters are more selective on vessel shape and less sensitive to intensity variations and noise. Using this segmentation technique along with optical micro-angiography allows label-free noninvasive simultaneous visualization of blood and lymphatic vessels in vivo. Lymphatic vessels play an important role in cancer, immune system response, inflammatory disease, wound healing and tissue regeneration. Development of imaging techniques and visualization tools for lymphatic vessels is valuable in understanding the mechanisms and studying therapeutic methods in related disease and tissue response. PMID:23922124

Circulatory failure during severe hyperthermia in dog.

PubMed

Miki, K; Morimoto, T; Nose, H; Itoh, T; Yamada, S

1983-01-01

The effect of acute hyperthermia on circulatory function was studied in 6 mongrel dogs. At a core temperature of about 40 degrees C, central venous pressure and stroke volume were maintained at almost normal level. Cardiac output significantly increased (26 ml/(kg . min)) while systemic vascular resistance significantly decreased (1.2 mmHg . sec/ml). In addition, significant decrease in vascular compliance by 40% was observed. When body temperature was raised further (severe hyperthermia), an abrupt fall of arterial pressure was observed at the rectal temperature of about 41-42 degrees C. Concomitant decreases in central venous pressure (3 mmHg), stroke volume (2.1 ml/beat) and cardiac output (29 ml/(kg . min)) were observed while heart rate increased (48 beats/min). These results suggest that the decrease in cardiac output during severe hyperthermia is due to the fall of central venous pressure, and the fall was attributed to the increase in unstressed vascular volume of systemic circulation due to the heat-induced cutaneous vasodilation. The observed decrease in systemic vascular compliance is considered to have a significant role in the maintenance of central venous pressure under hyperthermia.

Hemodynamic Responses to Head and Neck Cooling

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Carbo, Jorge E.; Montgomery, Leslie D.; Webbon, Bruce W.

1994-01-01

Personal thermoregulatory systems which provide head and neck cooling are used in the industrial and aerospace environments to alleviate thermal stress. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objective of this study was to measure the scalp temperature and circulatory responses during use of one commercially available thermal control system. The Life Support Systems, Inc. Mark VII portable cooling system and a liquid cooling helmet were used in this study. Two EEG electrodes and one skin temperature transducer were placed on the anterior midline of the scalp to measure the scalp blood and temperature. Blood flow was measured using a bipolar impedance rheograph. Ten subjects, seated in an upright position at normal room temperature, were tested at high, medium, moderate, moderate-low and low coolant temperatures. Scalp blood flow was recorded continuously using a computer data acquisition system with a sampling frequency of 200 Hz. Scalp temperature and cooling helmet Inlet temperature was logged periodically during the test period. This study quantifies the effect of head cooling upon scalp temperature and blood flow. These data may also be used to select operational specifications of the head cooling system for biomedical applications such as the treatment of migraine headaches, scalp cooling during chemotherapy, and cooling of multiple sclerosis patients.

[Clinical value of ammonia determination in venous blood in chronic cor pulmonale].

PubMed

Szulc, E J; Sworzyńska, I

1978-01-01

The authors have examined 43 workers of the Warszawa works: 20 healthy persons and 23 with chronic pulmocardiac syndrome. An increased ammonia level in venous blood, above 48 gamma %, was found in those with chronic pulmocardiac syndrome with simultaneous circulatory insufficiency. Ammonia level in the blood of those with chronic pulmocardiac syndrome but without circulatory insufficiency was normal. These studies indicate that the increase of ammonia concentration in venous blood in chronic pulmocardiac syndrome results from disturbance in hepatic cell function, intensified during circulatory insufficiency.

This Is Your Life.

ERIC Educational Resources Information Center

Knill, Fawcett

1982-01-01

Eleven questions, primarily dealing with the structure of the human body, are presented. In addition to a question on calculation of age in days, hours, minutes, and seconds, there are problems on the muscles, and the respiratory, circulatory, and skeletal systems. Answers to general questions are provided. (MP)

Liquid-circulating garment controls thermal balance

NASA Technical Reports Server (NTRS)

Kuznetz, L. H.

1977-01-01

Experimental data and mathematical model of human thermoregulatory system have been used to investigate use of liquid-circulatory garment (LCG) to control thermal balance. Model proved useful as accurate simulator of such variables as sweat rate, skin temperature, core temperature, and radiative, evaporative, and LCG heat loss.

Working Model Hearts

ERIC Educational Resources Information Center

Brock, David

2009-01-01

Despite student interest, the heart is often a poorly understood topic in biology. To help students understand this vital organ's physiology, the author created this investigation activity involving the mammalian heart and its role in the circulatory system. Students design, build, and demonstrate working artificial "hearts" to exhibit what they…

BEST: Bilingual environmental science training: Grades 5--6

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

NONE

This booklet is one of a series of bilingual guides to environmental-science learning activities for students to do at home. Lesson objectives, materials required, procedure, vocabulary, and subjects integrated into the lesson are described in English. A bilingual glossary, alphabetized by English entries, with Spanish equivalents and definitions in both English and Spanish, follows the lesson descriptions, and is itself followed by a bibliography of English-language references. This booklet includes descriptions of ten lessons that cover the following topics: safe and unsafe conditions for chemical combinations; growth rates and environmental needs of plants; photosynthesis and effects of ozone-layer depletion; themore » circulatory system, the importance of exercise to the heart, and selected circulatory diseases; the nervous system; specific nutritional values of the different food groups; significance of including, reducing, or eliminating certain foods for a healthy diet; effects of some common chemicals on plant growth and animal life; plants` and animals` natural habitats; and dangers of non-biodegradable garbage.« less

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

Wexler, J.P.; Davis, L.; Mancini, D.

Cardioactive drugs may effect both the central and peripheral circulatory systems. The effects on the central and peripheral circulatory systems of chronic Captorpril therapy in 7 pts with severe congestive heart failure (CHF) were evaluated simultaneously. Skeletal muscle blood flow (SMBF) determined using 133-Xe washout and a Cd/Te detector, oxygen consumption (VO/sub 2/), and radial artery and femoral vein O/sub 2/ concentration difference (A-V) were determined at rest and peak upright bicycle exercise before (BT) and after (AT) 6-12 weeks of Captopril therapy. In CI pts there was a significant increase in VO/sub 2/ and SMBF AT vs BT. Inmore » contrast, in CNC pts there was no change in VO/sub 2/ and a significant decrease in SMBF AT vs BT. In pts with severe CHF who are CI, there is an apparent fall in peripheral vascular resistance (PVR). In contrast, in CNC pts there is an increase in PVR. This study demonstrates that SMBF determines using 133-Xe is an important method for determining the effects of cardioactive drugs.« less

Beyond the VAD: Human Factors Engineering for Mechanically Assisted Circulation in the 21st Century.

PubMed

Throckmorton, Amy L; Patel-Raman, Sonna M; Fox, Carson S; Bass, Ellen J

2016-06-01

Thousands of ventricular assist devices (VADs) currently provide circulatory support to patients worldwide, and dozens of heart pump designs for adults and pediatric patients are under various stages of development in preparation for translation to clinical use. The successful bench-to-bedside development of a VAD involves a structured evaluation of possible system states, including human interaction with the device and auxiliary component usage in the hospital or home environment. In this study, we review the literature and present the current landscape of preclinical design and assessment, decision support tools and procedures, and patient-centered therapy. Gaps of knowledge are identified. The study findings support the need for more attention to user-centered design approaches for medical devices, such as mechanical circulatory assist systems, that specifically involve detailed qualitative and quantitative assessments of human-device interaction to mitigate risk and failure. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

WORLD AND NATIONAL EXPERIENCE IN ORGANIZATION OF PREVENTION OF CARDIOVASCULAR DISEASES.

PubMed

Biduchak, А; Chornenka, Zh

2017-11-01

The aim of the study was to examine the global, European and national experience in the implementation of preventive programs and to reveal their value in health, economy and social health development. The conducted research has found that the implementation of the national program, the correct methodological approach of the physician to evaluate risk factors, and implementing preventive measures of diseases of the circulatory system bring positive results (reduction of prevalence and incidence of cerebral stroke by 13,7% and 1,4%, respectively). The results of the analysis of the health care industry pointed out the possible directions of optimization of prevention of behavioral risk factors in the practice of family medicine as the first point of contact with the patient, where preventive measures are essential and effective. Summing up, it should be noted that at the level of primary health care, particularly family medicine, with effectively coordinated work and correctly set motivation, the preventive measures against risk factors of diseases of circulatory system can be quite effective.

The evaluation of the optimization design and application effect of same-well-injection-production technique’s injection-production circulatory system

NASA Astrophysics Data System (ADS)

Guoxing, Zheng; Minghu, Jiang; Hongliang, Gong; Nannan, Zhang; Jianguang, Wei

2018-02-01

According to basic principles of combining series of strata and demands of same-well injection-production technique, the optimization designing method of same-well injection-production technique’s injection-production circulatory system is given. Based on oil-water two-phase model with condition of arbitrarily well network, a dynamic forecast method for the application of same-well injection-production reservoir is established with considering the demands and capacity of same-well injection-production technique, sample wells are selected to launch the forecast evaluation and analysis of same-well injection-production reservoir application’s effect. Results show: single-test-well composite water cut decreases by 4.7% and test-well-group composite water cut decreases by 1.56% under the condition of basically invariant ground water injection rate. The method provides theoretical support for the proof of same-well injection-production technique’s reservoir development improving effect and further tests.

[Health situation of prisoners at a prison compliance centre, Chile].

PubMed

Osses-Paredes, C; Riquelme-Pereira, N

2013-02-01

There are population groups nowadays that are regarded as vulnerable, one of which is the prison population, considered to have major health needs. Nonetheless, people deprived of liberty maintain inherent human rights such as that of health care, which in some situations may take second place. Cross-sectional descriptive study, carried out at El Manzano Prison compliance centre, Concepción, from October 2011 to February 2012 with the implementation of a preventive health exam and a socio-demographic and health questionnaire, for 18+, female and male prisoners in a closed system, on reception of written informed consent. in the study, the population was 85% men, the average age was 34 years, 91.2% receive visits, average term of imprisonment 38 months. At least 45% have a diagnosed disease, prioritizing mental disorders, and respiratory and circulatory system diseases. 56% of prisoners have requested health care infrequently, 33% of which were very satisfied and 32% satisfied with prison health services. The health of the prison population is more impaired than that of the general population, with a larger number of needs that are also different, but there is a positive perception of health by prisoners and a high degree of satisfaction with health services.

Respite service use among caregivers of older people: comparative analysis of family dementia caregivers with musculoskeletal and circulatory system disorder caregivers.

PubMed

Vecchio, Nerina; Fitzgerald, Janna A; Radford, Katrina; Kurrle, Susan

2018-01-01

To identify the main drivers of the use of respite services and the need for respite services among caregivers of people experiencing dementia relative to family caregivers of people with other health conditions. Based on nationally representative secondary data regression analysis was used to test the association between selected health conditions and the utilisation of and need for respite services. For a person living with dementia the odds of using respite care are higher than for a person with either a musculoskeletal or circulatory condition. Family caregivers of people living with dementia report the odds of the need for more respite as 5.3 times higher than for family caregivers of people with musculoskeletal conditions and 7.7 times higher than for family caregivers of people with circulatory conditions. The main reason for never using respite services is largely driven by the type of health condition, age of care recipient, existence of a spouse, and level of disability. Respite services that cater to the specific needs of families experiencing dementia at home should become a higher priority within the aged care sector. Alternative models of respite care that focus on prevention and early intervention would be cost effective.

The Role of Self-Regulated Learning in Fostering Students' Conceptual Understanding of Complex Systems with Hypermedia

ERIC Educational Resources Information Center

Azevedo, Roger; Guthrie, John T.; Seibert, Diane

2004-01-01

This study examines the role of self-regulated learning (SRL) in facilitating students' shifts to more sophisticated mental models of the circulatory system as indicated by both performance and process data. We began with Winne and colleagues' information processing model of SRL (Winne, 2001; Winne & Hadwin, 1998) and used it to examine how…

Use of a Left Ventricular Assist Device as a Bridge to Transplantation in a Pediatric Patient

PubMed Central

Frazier, O.H.; Bricker, J. Timothy; Macris, Michael P.; Cooley, Denton A.

1989-01-01

Despite many advances in heart transplantation and in mechanical circulatory support, the benefits of staged cardiac transplantation have not been extended to the pediatric transplant recipient, chiefly because implantable circulatory assist devices are still too large. Extracorporeal devices, however, can overcome this impediment. Here we report the 1st case, to our knowledge, in which an extracorporeal left ventricular assist device has been used in a child to support circulation prior to cardiac transplantation. The patient was a 9-year-old boy in New York Heart Association functional class IV, with congestive heart failure as a result of idiopathic biventricular cardiomegaly. In mid-May of 1987, while awaiting a suitable donor, he suffered severe oliguria after an episode of circulatory arrest. Therefore we decided to maintain his circulation—and consequently his peripheral organ function—with an extracorporeal left ventricular assist device. After establishing cardiopulmonary bypass under normothermia and without cardiac arrest, we established flow from the left ventricle through a 36-Fr wire-reinforced straight cannula to a Biomedicus BP-80 centrifugal force pump, with return to the proximal ascending aorta through a 28-Fr wire-reinforced straight cannula. The patient's hemodynamic course under subsequent mechanical circulatory support was remarkably stable, with controllable systemic hypertension and no evidence of hemolysis. Although cardiac activity was minimal and systemic blood flow nonpulsatile, the patient's renal, pulmonary, and hepatic functions improved, and his peripheral circulation was well preserved. After 12 hours of support, a donor heart became available, and a routine orthotopic cardiac transplant was performed. Upon removal, the left ventricular assist device showed a small amount of thrombus formation. The patient's postoperative recovery has been easily manageable, and 20 months after transplant he enjoys unrestricted physical activity. We conclude that an extracorporeal left ventricular assist device can be used as a bridge to cardiac transplantation in children. Moreover, this application of a continuous force centrifugal pump without adverse effect encourages the conclusion that long-term maintenance of terminal heart disease patients might be possible through development of small, implantable pumps with the potential of lower power requirements and reduced thrombogenesis. (Texas Heart Institute Journal 1989;16:46-50) PMID:15227237

An architecture for rapid prototyping of control schemes for artificial ventricles.

PubMed

Ficola, Antonio; Pagnottelli, Stefano; Valigi, Paolo; Zoppitelli, Maurizio

2004-01-01

This paper presents an experimental system aimed at rapid prototyping of feedback control schemes for ventricular assist devices, and artificial ventricles in general. The system comprises a classical mock circulatory system, an actuated bellow-based ventricle chamber, and a software architecture for control schemes implementation and experimental data acquisition, visualization and storing. Several experiments have been carried out, showing good performance of ventricular pressure tracking control schemes.

The importance of the renin-angiotensin system in normal cardiovascular homeostasis

NASA Technical Reports Server (NTRS)

Haber, E.

1975-01-01

Studies were carried out on adult mongrel dogs (20 to 30 kilograms) to investigate the importance of the renin-angiotensin system. Results indicate that the renin-angiotensin system plays a major role in the maintenance of circulatory homeostasis when extracellular fluid volume is depleted. It was also found that angiotensin II concentration, in addition to renal perfusion pressure, is a factor in the regulation of renin release.

Circulatory response and autonomic nervous activity during gum chewing.

PubMed

Hasegawa, Yoko; Sakagami, Joe; Ono, Takahiro; Hori, Kazuhiro; Zhang, Min; Maeda, Yoshinobu

2009-08-01

Mastication has been proven to enhance the systemic circulation, with circulatory responses seeming to be largely regulated by autonomic nervous activity via a more complex regulatory system than those of other activities. However, few studies have examined the relationships between changes in autonomic nervous activity and the systemic circulation that are induced by masticatory movement. We investigated changes in the systemic circulation and autonomic nervous activity during gum chewing to clarify the influence of mastication. Electrocardiograms, arterial blood pressure, and masseter electromyograms were taken while chewing gum continuously as indicators of systemic circulation in 10 healthy subjects with normal dentition. Cardiac sympathetic activity and vagus nervous activity, as well as vasomotor sympathetic nervous activity, were evaluated by fluctuation analysis of heart rate and blood pressure. Repeated analysis of variance and multiple comparisons were performed to determine chronological changes in each indicator during gum chewing. Gum chewing increased the heart rate and the mean arterial pressure. Although cardiac sympathetic activity and vagus nervous activity showed significant changes, vasomotor sympathetic nervous activity did not. These results suggest that changes in the autonomic nervous activity of the heart are mainly involved in the enhancement of systemic circulation with gum chewing. This explains some characteristics of autonomic nervous regulation in masticatory movement.

[(Pro) renin receptor in the pathogenesis of proliferative diabetic retinopathy].

PubMed

Kanda, Atsuhiro

2014-11-01

The renin-angiotensin system (RAS), originally regarded as an important controller of systemic blood pressure (circulatory RAS), plays a pivotal role in pathological vascular conditions including inflammation and angiogenesis (tissue RAS). (Pro) renin receptor [(P) RR] is known to bind with prorenin causing the dual activation of tissue renin-angiotensin system (RAS) together with RAS-independent intracellular signaling pathways and contributes to the molecular pathogenesis of end-organ damage. In this review, we investigated localization and expression of (P)RR in fibrovascular tissues and vitreous fluids from patients with proliferative diabetic retinopathy and evaluated the molecular mechanisms in vitro in order to confirm the conclusions regarding (P) RR from animal studies. (P)RR immunoreactivity was detected in vascular endothelial cells, co-localized with prorenin, phosphorylated extracellular signal-regulated kinase and vascular endothelial growth factor (VEGF). Protein levels of soluble (P) RR in the vitreous fluids were higher in proliferative diabetic retinopathy (PDR) eyes than in non-diabetic control eyes, and were significantly correlated with vitreous VEGF levels and the vascular density of fibrovascular tissues. We herein report the first evidence that shows the close association of (P) RR with angiogenic activity in human PDR. The present data suggest the validity of (P) RR as a molecular target for the treatment of PDR.

Canadian Guidelines for Controlled Pediatric Donation After Circulatory Determination of Death—Summary Report*

PubMed Central

Hornby, Laura; Rochwerg, Bram; van Manen, Michael; Dhanani, ; Sonny; Sivarajan, V. Ben; Appleby, Amber; Bennett, Mary; Buchman, Daniel; Farrell, Catherine; Goldberg, Aviva; Greenberg, Rebecca; Singh, Ram; Nakagawa, Thomas A.; Witteman, William; Barter, Jill; Beck, Allon; Coughlin, Kevin; Conradi, Alf; Cupido, Cynthia; Dawson, Rosanne; Dipchand, Anne; Freed, Darren; Hornby, Karen; Langlois, Valerie; Mack, Cheryl; Mahoney, Meagan; Manhas, Deepak; Tomlinson, Christopher; Zavalkoff, Samara; Shemie, Sam D.

2017-01-01

Objectives: Create trustworthy, rigorous, national clinical practice guidelines for the practice of pediatric donation after circulatory determination of death in Canada. Methods: We followed a process of clinical practice guideline development based on World Health Organization and Canadian Medical Association methods. This included application of Grading of Recommendations Assessment, Development, and Evaluation methodology. Questions requiring recommendations were generated based on 1) 2006 Canadian donation after circulatory determination of death guidelines (not pediatric specific), 2) a multidisciplinary symposium of national and international pediatric donation after circulatory determination of death leaders, and 3) a scoping review of the pediatric donation after circulatory determination of death literature. Input from these sources drove drafting of actionable questions and Good Practice Statements, as defined by the Grading of Recommendations Assessment, Development, and Evaluation group. We performed additional literature reviews for all actionable questions. Evidence was assessed for quality using Grading of Recommendations Assessment, Development, and Evaluation and then formulated into evidence profiles that informed recommendations through the evidence-to-decision framework. Recommendations were revised through consensus among members of seven topic-specific working groups and finalized during meetings of working group leads and the planning committee. External review was provided by pediatric, critical care, and critical care nursing professional societies and patient partners. Results: We generated 63 Good Practice Statements and seven Grading of Recommendations Assessment, Development, and Evaluation recommendations covering 1) ethics, consent, and withdrawal of life-sustaining therapy, 2) eligibility, 3) withdrawal of life-sustaining therapy practices, 4) ante and postmortem interventions, 5) death determination, 6) neonatal pediatric donation after circulatory determination of death, 7) cardiac and innovative pediatric donation after circulatory determination of death, and 8) implementation. For brevity, 48 Good Practice Statement and truncated justification are included in this summary report. The remaining recommendations, detailed methodology, full Grading of Recommendations Assessment, Development, and Evaluation tables, and expanded justifications are available in the full text report. Conclusions: This process showed that rigorous, transparent clinical practice guideline development is possible in the domain of pediatric deceased donation. Application of these recommendations will increase access to pediatric donation after circulatory determination of death across Canada and may serve as a model for future clinical practice guideline development in deceased donation. PMID:28925929

Simple Model of the Circulation.

ERIC Educational Resources Information Center

Greenway, Clive A.

1980-01-01

Describes a program in BASIC-11 that explores the relationships between various variables in the circulatory system and permits manipulation of several semiindependent variables to model the effects of hemorrhage, drug infusions, etc. A flow chart and accompanying sample printout are provided; the program is listed in the appendix. (CS)

Be Still My Heart.

ERIC Educational Resources Information Center

Barber, Betsy; Ball, Rhonda

This project description is designed to show how graphing calculators and calculator-based laboratories (CBLs) can be used to explore topics in physics and health sciences. The activities address such topics as respiration, heart rate, and the circulatory system. Teaching notes and calculator instructions are included as are blackline masters. (MM)

A Mock Circulatory System Incorporating a Compliant 3D-Printed Anatomical Model to Investigate Pulmonary Hemodynamics.

PubMed

Knoops, Paul G M; Biglino, Giovanni; Hughes, Alun D; Parker, Kim H; Xu, Linzhang; Schievano, Silvia; Torii, Ryo

2017-07-01

A realistic mock circulatory system (MCS) could be a valuable in vitro testbed to study human circulatory hemodynamics. The objective of this study was to design a MCS replicating the pulmonary arterial circulation, incorporating an anatomically representative arterial model suitable for testing clinically relevant scenarios. A second objective of the study was to ensure the system's compatibility with magnetic resonance imaging (MRI) for additional measurements. A latex pulmonary arterial model with two generations of bifurcations was manufactured starting from a 3D-printed mold reconstructed from patient data. The model was incorporated into a MCS for in vitro hydrodynamic measurements. The setup was tested under physiological pulsatile flow conditions and results were evaluated using wave intensity analysis (WIA) to investigate waves traveling in the arterial system. Increased pulmonary vascular resistance (IPVR) was simulated as an example of one pathological scenario. Flow split between right and left pulmonary artery was found to be realistic (54 and 46%, respectively). No substantial difference in pressure waveform was observed throughout the various generations of bifurcations. Based on WIA, three main waves were identified in the main pulmonary artery (MPA), that is, forward compression wave, backward compression wave, and forward expansion wave. For IPVR, a rise in mean pressure was recorded in the MPA, within the clinical range of pulmonary arterial hypertension. The feasibility of using the MCS in the MRI scanner was demonstrated with the MCS running 2 h consecutively while acquiring preliminary MRI data. This study shows the development and verification of a pulmonary MCS, including an anatomically correct, compliant latex phantom. The setup can be useful to explore a wide range of hemodynamic questions, including the development of patient- and pathology-specific models, considering the ease and low cost of producing rapid prototyping molds, and the versatility of the setup for invasive and noninvasive (i.e., MRI) measurements. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

A Mock Circulatory System Incorporating a Compliant 3D-Printed Anatomical Model to Investigate Pulmonary Hemodynamics

PubMed Central

Knoops, Paul G.M.; Biglino, Giovanni; Hughes, Alun D.; Parker, Kim H.; Xu, Linzhang; Schievano, Silvia; Torii, Ryo

2017-01-01

A realistic mock circulatory system (MCS) could be a valuable in vitro testbed to study human circulatory hemodynamics. The objective of this study was to design a MCS replicating the pulmonary arterial circulation, incorporating an anatomically representative arterial model suitable for testing clinically relevant scenarios. A second objective of the study was to ensure the system's compatibility with magnetic resonance imaging (MRI) for additional measurements. A latex pulmonary arterial model with two generations of bifurcations was manufactured starting from a 3D-printed mold reconstructed from patient data. The model was incorporated into a MCS for in vitro hydrodynamic measurements. The setup was tested under physiological pulsatile flow conditions and results were evaluated using wave intensity analysis (WIA) to investigate waves traveling in the arterial system. Increased pulmonary vascular resistance (IPVR) was simulated as an example of one pathological scenario. Flow split between right and left pulmonary artery was found to be realistic (54 and 46%, respectively). No substantial difference in pressure waveform was observed throughout the various generations of bifurcations. Based on WIA, three main waves were identified in the main pulmonary artery (MPA), that is, forward compression wave, backward compression wave, and forward expansion wave. For IPVR, a rise in mean pressure was recorded in the MPA, within the clinical range of pulmonary arterial hypertension. The feasibility of using the MCS in the MRI scanner was demonstrated with the MCS running 2 h consecutively while acquiring preliminary MRI data. This study shows the development and verification of a pulmonary MCS, including an anatomically correct, compliant latex phantom. The setup can be useful to explore a wide range of hemodynamic questions, including the development of patient- and pathology-specific models, considering the ease and low cost of producing rapid prototyping molds, and the versatility of the setup for invasive and noninvasive (i.e., MRI) measurements. PMID:27925228

Temporary Mechanical Circulatory Support: A Review of the Options, Indications, and Outcomes

PubMed Central

Gilotra, Nisha A; Stevens, Gerin R

2014-01-01

Cardiogenic shock remains a challenging disease entity and is associated with significant morbidity and mortality. Temporary mechanical circulatory support (MCS) can be implemented in an acute setting to stabilize acutely ill patients with cardiomyopathy in a variety of clinical situations. Currently, several options exist for temporary MCS. We review the indications, contraindications, clinical applications, and evidences for a variety of temporary circulatory support options, including the intra-aortic balloon pump (IABP), extracorporeal membrane oxygenation (ECMO), CentriMag blood pump, and percutaneous ventricular assist devices (pVADs), specifically the TandemHeart and Impella. PMID:25674024

A new crustacean from the Herefordshire (Silurian) Lagerstätte, UK, and its significance in malacostracan evolution

PubMed Central

Briggs, Derek E. G.; Siveter, Derek J.; Sutton, Mark D.; Legg, David

2017-01-01

Cascolus ravitis gen. et sp. nov. is a three-dimensionally preserved fossil crustacean with soft parts from the Herefordshire (Silurian) Lagerstätte, UK. It is characterized by a head with a head shield and five limb pairs, and a thorax (pereon) with nine appendage-bearing segments followed by an apodous abdomen (pleon). All the appendages except the first are biramous and have a gnathobase. The post-mandibular appendages are similar one to another, and bear petal-shaped epipods that probably functioned as a part of the respiratory–circulatory system. Cladistic analysis resolves the new taxon as a stem-group leptostracan (Malacostraca). This well-preserved arthropod provides novel insights into the evolution of appendage morphology, tagmosis and the possible respiratory–circulatory physiology of a basal malacostracan. PMID:28330926

Complexity of Human Circulation Design: Tips for Students

ERIC Educational Resources Information Center

Kurbel, Sven; Gros, Mario; Maric, Svjetlana

2009-01-01

Medical students are faced with a challenge to comprehend the enormous complexity of the circulatory systems. There is a gap between courses of anatomy, with detailed description of all normally present macroscopic vessels, and histology, which is focused on microscopic tissue architecture. Both courses leave arterioles, capillaries, and venules…

Infrared Thermographic Measurement of Long Term Circulatory Compromise in Trenchfoot Injured Argentine Soldiers

DTIC Science & Technology

1989-02-17

surface pain, cold sensitivity or hyperhidrosis . Equipment The subject’s temperatures were monitored by utilizing an AGEMA TIC-8000 Infrared System...injury; the patient’s reports of cold intolerance, weight bearing surface pain and hyperhidrosis six years post injury support this conclusion. It

Microgravity

NASA Image and Video Library

1992-03-12

Contributes to many transport and regulatory processes and has multifunctional binding properties which range form various metals, to fatty acids, hormones, and a wide spectrum of therapeutic drugs. The most abundant protein of the circulatory system. It binds and transports an incredible variety of biological and pharmaceutical ligands throughout the blood stream. Principal Investigator was Larry DeLucas.

Ballistocardiography in the Physics Classroom

ERIC Educational Resources Information Center

Paul, Prabasaj; Symes, Laurel B.

2008-01-01

Ballistocardiograms (BCGs) are graphical representations of the recoil from the pumping action of the heart. Introductory mechanics and a basic knowledge of the circulatory system are sufficient to understand the key features of a BCG. BCGs with adequate detail for instructional purposes may be produced easily and rapidly using hardware (a force…

Web-Based Lessons from Frontliners.

ERIC Educational Resources Information Center

Joseph, Linda C.

1998-01-01

Describes Web-site lessons and resources on the role of women in history, games, circulatory system, the study of color for emergent readers, ePals classroom exchange for French students, nutrition and the food pyramid for elementary and secondary students, and classroom management for teachers. Provides URLs for related Web sites. (PEN)

A Student Diffusion Activity

ERIC Educational Resources Information Center

Kutzner, Mickey; Pearson, Bryan

2017-01-01

Diffusion is a truly interdisciplinary topic bridging all areas of STEM education. When biomolecules are not being moved through the body by fluid flow through the circulatory system or by molecular motors, diffusion is the primary mode of transport over short distances. The direction of the diffusive flow of particles is from high concentration…

Hearts and Onions: A Second Look at the Commonplace.

ERIC Educational Resources Information Center

Flannery, Maura C., Ed.

1991-01-01

Presents instructional methods biology teachers can use to make their presentations more interesting. Author describes variety of methods for introducing lesson on the heart and discusses use of metaphors, form, models, and fractals in instruction pertaining to circulatory system. Presents idea of using Capon's "The Supper of the Lamb"…

Cardiovascular Disease and Cancer: Student Awareness Activities.

ERIC Educational Resources Information Center

Meyer, James H., Comp.

Awareness activities pertaining to cancer and cardiovascular disease are presented as a supplement for high school science classes. The exercises can be used to enrich units of study dealing with the circulatory system, the cell, or human diseases. Eight activities deal with the following topics: (1) cardiovascular disease risk factors; (2)…

A Simple Model of the Pulmonary Circulation for Hemodynamic Study and Examination.

ERIC Educational Resources Information Center

Gaar, Kermit A., Jr.

1983-01-01

Describes a computer program allowing students to study such circulatory variables as venus return, cardiac output, mean circulatory filling pressure, resistance to venous return, and equilibrium point. Documentation for this Applesoft program (or diskette) is available from author. (JM)

Early Identification of Circulatory Shock in Critical Care Transport

DTIC Science & Technology

2008-09-30

disclosure and community consultation. Early Identification of Circulatory Shock in Critical Care Transport 2 Community consultation for this...in two aircraft types (Eurocopter EC 135 and EC 145), in IFR weather conditions, and during both day and night operations. We calculated the

Analysis of Dose Response for Circulatory Disease After Radiotherapy for Benign Disease

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

Little, Mark P., E-mail: mark.little@nih.gov; Kleinerman, Ruth A.; Stovall, Marilyn

Purpose: To assess the shape of the dose-response for various circulatory disease endpoints, and modifiers by age and time since exposure. Methods and Materials: This was an analysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by circulatory disease endpoint (ischemic heart, cerebrovascular, other circulatory disease). Results: There were significant excess risks for all circulatory disease, with an excess relative risk Gy{sup -1} of 0.082 (95% CI 0.031-0.140), and ischemic heart disease, with an excess relative risk Gy{sup -1} of 0.102 (95% CI 0.039-0.174) (both p = 0.01), and indications of excess risk for stroke. Theremore » were no statistically significant (p > 0.2) differences between risks by endpoint, and few indications of curvature in the dose-response. There were significant (p < 0.001) modifications of relative risk by time since exposure, the magnitude of which did not vary between endpoints (p > 0.2). Risk modifications were similar if analysis was restricted to patients receiving radiation, although the relative risks were slightly larger and the risk of stroke failed to be significant. The slopes of the dose-response were generally consistent with those observed in the Japanese atomic bomb survivors and in occupationally and medically exposed groups. Conclusions: There were excess risks for a variety of circulatory diseases in this dataset, with significant modification of risk by time since exposure. The consistency of the dose-response slopes with those observed in radiotherapeutically treated groups at much higher dose, as well as in lower dose-exposed cohorts such as the Japanese atomic bomb survivors and nuclear workers, implies that there may be little sparing effect of fractionation of dose or low-dose-rate exposure.« less

Changing mortality patterns in East and West Germany and Poland. II: Short-term trends during transition and in the 1990s

PubMed Central

Nolte, E.; Shkolnikov, V.; McKee, M.

2000-01-01

OBJECTIVES—To examine trends in life expectancy at birth and age and cause specific patterns of mortality in the former German Democratic Republic (GDR) and Poland during political transition and throughout the 1990s in both parts of Germany and in Poland.
METHODS—Decomposition of life expectancy by age and cause of death. Changes in life expectancy during transition by cause of death were examined using data for 1988/89 and 1990/91 for the former GDR and Poland; examination of life expectancy changes after transition were based on 1992-97 data for Germany and 1991-96 data for Poland.
RESULTS—In both the former GDR and Poland male life expectancy at birth declined by almost one year during transition, mainly attributable to rising death rates from external causes and circulatory diseases. Female life expectancy in Poland deteriorated by 0.3 years, largely attributable to increasing circulatory mortality among the old, while in East German female rising death rates in children and young adults were nearly outbalanced by declining circulatory mortality among those over 70. Between 1991/92 and 1996/97, male life expectancy at birth increased by 2.4 years in the former GDR, 1.2 years in old Federal Republic, and 2.0 years in Poland (women: 2.3, 0.9, and 1.2 years). In East Germany and Poland, the overall improvement was largely attributable to falling mortality among men aged 40-64, while those over 65 contributed the largest proportion to life expectancy gains in women. The change in deaths among men aged 15-39 accounted for 0.4 of a year to life expectancy at birth in East Germany and Poland, attributable largely to greater decreases from external causes. Among those over 40, absolute contributions to changing life expectancy were greater in the former GDR than in the other two entities in both sexes, largely attributable to circulatory diseases. A persisting East-west life expectancy gap in Germany of 2.1 years in men in 1997 was largely attributable to external causes, diseases of the digestive system and circulatory diseases. Higher death rates from circulatory diseases among the elderly largely explain the female life expectancy gap of approximately one year.
CONCLUSIONS—This study provides further insights into the health effects of political transition. Post-transition improvements in life expectancy and mortality have been much steeper in East Germany compared with Poland. Changes in dietary pattern and, in Germany, medical care may have been important factors in shaping post-transition mortality trends. 


Keywords: mortality trends; Germany; Poland; transition PMID:11076985

Depiction of Trends in Administrative Healthcare Data from Hospital Information System.

PubMed

Kalankesh, Leila R; Pourasghar, Faramarz; Jafarabadi, Mohammad Asghari; Khanehdan, Negar

2015-06-01

administrative healthcare data are among main components of hospital information system. Such data can be analyzed and deployed for a variety of purposes. The principal aim of this research was to depict trends of administrative healthcare data from HIS in a general hospital from March 2011 to March 2014. data set used for this research was extracted from the SQL database of the hospital information system in Razi general hospital located in Marand. The data were saved as CSV (Comma Separated Values) in order to facilitate data cleaning and analysis. The variables of data set included patient's age, gender, final diagnosis, final diagnosis code based on ICD-10 classification system, date of hospitalization, date of discharge, LOS(Length of Stay), ward, and survival status of the patient. Data were analyzed and visualized after applying appropriate cleansing and preparing techniques. morbidity showed a constant trend over three years. Pregnancy, childbirth and the puerperium were the leading category of final diagnosis (about 32.8 %). The diseases of the circulatory system were the second class accounting for 13 percent of the hospitalization cases. The diseases of the digestive system had the third rank (10%). Patients aged between 14 and 44 constituted a higher proportion of total cases. Diseases of the circulatory system was the most common class of diseases among elderly patients (age≥65). The highest rate of mortality was observed among patients with final diagnosis of the circulatory system diseases followed by those with diseases of the respiratory system, and neoplasms. Mortality rate for the ICU and the CCU patients were 62% and 33% respectively. The longest average of LOS (7.3 days) was observed among patients hospitalized in the ICU while patients in the Obstetrics and Gynecology ward had the shortest average of LOS (2.4 days). Multiple regression analysis revealed that LOS was correlated with variables of surgery, gender, and type of payment, ward, the class of final diagnosis and age. this study presents trends in administrative health care data residing in hospital information system of a general public hospital. Patterns in morbidity, mortality and length of stay can inform decision making in health care management. Mining trends in administrative healthcare data can add value to the health care management.

Mechanical Circulatory Support Devices for Acute Right Ventricular Failure.

PubMed

Kapur, Navin K; Esposito, Michele L; Bader, Yousef; Morine, Kevin J; Kiernan, Michael S; Pham, Duc Thinh; Burkhoff, Daniel

2017-07-18

Right ventricular (RV) failure remains a major cause of global morbidity and mortality for patients with advanced heart failure, pulmonary hypertension, or acute myocardial infarction and after major cardiac surgery. Over the past 2 decades, percutaneously delivered acute mechanical circulatory support pumps specifically designed to support RV failure have been introduced into clinical practice. RV acute mechanical circulatory support now represents an important step in the management of RV failure and provides an opportunity to rapidly stabilize patients with cardiogenic shock involving the RV. As experience with RV devices grows, their role as mechanical therapies for RV failure will depend less on the technical ability to place the device and more on improved algorithms for identifying RV failure, patient monitoring, and weaning protocols for both isolated RV failure and biventricular failure. In this review, we discuss the pathophysiology of acute RV failure and both the mechanism of action and clinical data exploring the utility of existing RV acute mechanical circulatory support devices. © 2017 American Heart Association, Inc.

Leg ischaemia before circulatory arrest alters brain leucocyte count and respiratory chain redox state.

PubMed

Yannopoulos, Fredrik S; Arvola, Oiva; Haapanen, Henri; Herajärvi, Johanna; Miinalainen, Ilkka; Jensen, Hanna; Kiviluoma, Kai; Juvonen, Tatu

2014-03-01

Remote ischaemic preconditioning and its neuroprotective abilities are currently under investigation and the method has shown significant effects in several small and large animal studies. In our previous studies, leucocyte filtration during cardiopulmonary bypass reduced cerebrocortical adherent leucocyte count and mitigated cerebral damage after hypothermic circulatory arrest (HCA) in piglets. This study aimed to obtain and assess direct visual data of leucocyte behaviour in cerebral vessels after hypothermic circulatory arrest following remote ischaemic preconditioning. Twelve native stock piglets were randomized into a remote ischaemic preconditioning group (n = 6) and a control group (n = 6). The intervention group underwent hind-leg ischaemia, whereas the control group received a sham-treatment before a 60-min period of hypothermic circulatory arrest. An intravital microscope was used to obtain measurements from the cerebrocortical vessel in vivo. It included three sets of filters: a violet filter to visualize microvascular perfusion and vessel diameter, a green filter for visualization of rhodamine-labelled leucocytes and an ultraviolet filter for reduced nicotinamide adenine dinucleotide (NADH) analysis. The final magnification on the microscope was 400. After the experiment, cerebral and cerebellar biopsies were collected and analysed with transmission electron microscope by a blinded analyst. In the transmission electron microscope analysis, the entire intervention group had normal, unaffected rough endoplasmic reticulum's in their cerebellar tissue, whereas the control group had a mean score of 1.06 (standard deviation 0.41) (P = 0.026). The measured amount of adherent leucocytes was lower in the remote ischaemic preconditioning group. The difference was statistically significant at 5, 15 and 45 min after circulatory arrest. Statistically significant differences were seen also in the recovery phase at 90 and 120 min after reperfusion. Nicotinamide adenine dinucleotide autofluorescence had statistically significant differences at 10 min after cooling and at 120 and 180 min after hypothermic circulatory arrest. Remote ischaemic preconditioning seems to provide better mitochondrial respiratory chain function as indicated by the higher NADH content. It simultaneously provides a reduction of adherent leucocytes in cerebral vessels after hypothermic circulatory arrest. Additionally, it might provide some degree of cellular organ preservation as implied by the electron microscopy results.

The role of extracorporeal membrane oxygenation circulatory support in the 'crash and burn' patient: from implantation to weaning.

PubMed

Ghodsizad, Ali; Koerner, Michael M; Brehm, Christoph E; El-Banayosy, Aly

2014-05-01

In advanced cardiogenic shock, early mechanical circulatory support may prevent multiorgan failure and death. In this article, we are describing our experience with extracorporeal membrane oxygenation (ECMO) application. Venoarterial ECMO has been used successfully as a therapeutic option for patients with advanced cardiogenic shock and cardiac arrest. In this review, based on the daily routine of the Hershey group using ECMO for therapy of advanced cardiogenic shock, the application of ECMO is described. The aim is to share our hands-on experience during emergent implantation and to contribute to the knowledge within the field of mechanical circulatory support.

Electroencephalographic Recordings During Withdrawal of Life-Sustaining Therapy Until 30 Minutes After Declaration of Death.

PubMed

Norton, Loretta; Gibson, Raechelle M; Gofton, Teneille; Benson, Carolyn; Dhanani, Sonny; Shemie, Sam D; Hornby, Laura; Ward, Roxanne; Young, G Bryan

2017-03-01

The timing of the circulatory determination of death for organ donation presents a medical and ethical challenge. Concerns have been raised about the timing of electrocerebral inactivity in relation to the cessation of circulatory function in organ donation after cardio-circulatory death. Nonprocessed electroencephalographic (EEG) measures have not been characterized and may provide insight into neurological function during this process. We assessed electrocortical data in relation to cardiac function after withdrawal of life-sustaining therapy and in the postmortem period after cardiac arrest for four patients in a Canadian intensive care unit. Subhairline EEG and cardio-circulatory monitoring including electrocardiogram, arterial blood pressure (ABP), and oxygen saturation were captured. Electrocerebral inactivity preceded the cessation of the cardiac rhythm and ABP in three patients. In one patient, single delta wave bursts persisted following the cessation of both the cardiac rhythm and ABP. There was a significant difference in EEG amplitude between the 30-minute period before and the 5-minute period following ABP cessation for the group, but we did not observe any well-defined EEG states following the early cardiac arrest period. In a case series of four patients, EEG inactivity preceded electrocardiogram and ABP inactivity during the dying process in three patients. Further study of the electroencephalogram during the withdrawal of life sustaining therapies will add clarity to medical, ethical, and legal concerns for donation after circulatory determined death.

Functional stability of cerebral circulatory system

NASA Technical Reports Server (NTRS)

Moskalenko, Y. Y.

1980-01-01

The functional stability of the cerebral circulation system seems to be based on the active mechanisms and on those stemming from specific of the biophysical structure of the system under study. This latter parameter has some relevant criteria for its quantitative estimation. The data obtained suggest that the essential part of the mechanism for active responses of cerebral vessels which maintains the functional stability of this portion of the vascular system, consists of a neurogenic component involving central nervous structures localized, for instance, in the medulla oblongata.

The eye and visual nervous system: anatomy, physiology and toxicology.

PubMed Central

McCaa, C S

1982-01-01

The eyes are at risk to environmental injury by direct exposure to airborne pollutants, to splash injury from chemicals and to exposure via the circulatory system to numerous drugs and bloodborne toxins. In addition, drugs or toxins can destroy vision by damaging the visual nervous system. This review describes the anatomy and physiology of the eye and visual nervous system and includes a discussion of some of the more common toxins affecting vision in man. Images FIGURE 1. FIGURE 2. PMID:7084144

21 CFR 101.77 - Health claims: fruits, vegetables, and grain products that contain fiber, particularly soluble...

Code of Federal Regulations, 2010 CFR

2010-04-01

... coronary heart disease. (1) Cardiovascular disease means diseases of the heart and circulatory system. Coronary heart disease is the most common and serious form of cardiovascular disease and refers to diseases... products that contain fiber, particularly soluble fiber, and risk of coronary heart disease. 101.77 Section...

Adolescents' Use of Self-Regulatory Processes and Their Relation to Qualitative Mental Model Shifts while Using Hypermedia

ERIC Educational Resources Information Center

Greene, Jeffrey Alan; Azevedo, Roger

2007-01-01

This study examined 148 adolescents' use of self-regulated learning (SRL) processes when learning about the circulatory system using hypermedia. We examined participants' verbal protocols to determine the relationship between SRL processes and qualitative shifts in students' mental models from pretest to posttest. Results indicated that…

Stress and Children: A Theoretical Overview.

ERIC Educational Resources Information Center

Duncan, David F.

Children experience stress just as adults do. Various responses to stress can damage the body's health in at least two different ways. First, they may do direct damage to the tissues--especially those of the circulatory system. Second, and more often important to the health of children, they may suppress the body's natural defenses against…

78 FR 67365 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-12

... reduce the risk of life-threatening bleeding events in patients with non-valvular atrial fibrillation who... premarket approval application regarding the Boston Scientific WATCHMAN Left Atrial Appendage (LAA) Closure... placed in the left atrial appendage. This device is intended to prevent thrombus embolization from the...

The Effect of Knowledge Linking Levels in Biology Lessons upon Students' Knowledge Structure

ERIC Educational Resources Information Center

Wadouh, Julia; Liu, Ning; Sandmann, Angela; Neuhaus, Birgit J.

2014-01-01

Knowledge structure is an important aspect for defining students' competency in biology learning, but how knowledge structure is influenced by the teaching process in naturalistic biology classroom settings has scarcely been empirically investigated. In this study, 49 biology lessons in the teaching unit "blood and circulatory system" in…

"And the Beat Goes Ona... Building Artificial Hearts in the Classroom.

ERIC Educational Resources Information Center

Brock, David L.

2000-01-01

Among the many ideas and theories in anatomy and physiology, one particular topic provides all the potential benefits of learning about the human body: the circulatory system, specifically the heart. Describes a distinctive way to study circulation and the heart that allows students to explore the basic principles of vertebrate anatomy and…

Computer Model of Aspirin bound to Human Serum Albumin

NASA Technical Reports Server (NTRS)

1989-01-01

Contributes to many transport and regulatory processes and has multifunctional binding properties which range form various metals, to fatty acids, hormones, and a wide spectrum of therapeutic drugs. The most abundant protein of the circulatory system. It binds and transports an incredible variety of biological and pharmaceutical ligands throughout the blood stream.

The Future of Adult Cardiac Assist Devices: Novel Systems and Mechanical Circulatory Support Strategies

PubMed Central

Bartoli, Carlo R.; Dowling, Robert D.

2011-01-01

Synopsis The recent, widespread success of mechanical circulatory support has ushered in a new era of cardiovascular medicine in which numerous implantable devices exist to treat advanced heart failure. As cardiac assist devices gain prevalence in the clinical management of cardiovascular disease, it is increasingly important to raise awareness of novel device systems, the unique mechanisms by which they function, and implications for patient management. In this article, we present state-of-the-art devices that are currently under development or in clinical trials. Devices are categorized as Standard Full-Support (HeartMate III, CorAide, Evaheart LVAS), Less-Invasive Full-Support (MVAD), Partial-Support (CircuLite Synergy Pocket Micro-Pump, Reitan Catheter Pump, Procyrion CAD, C-Pulse, Symphony Counterpulsation Device) Right Ventricular Assist Device (RVAD; DexAide, Impella RD Recover, Impella RP), and Total Artificial Heart (TAH; CardioWest, AbioCor II, Continuous-Flow TAH, Continuous-Flow BiVAD). Implantation strategy, mechanism of action, durability, efficacy, hemocompatibility, and human factors such as quality of life during device support are considered. The feasibility of novel strategies for unloading the failing heart is examined. PMID:22062206

[Cost of drugs used to treat cardiovascular disease in Brazil].

PubMed

Bueno, Cristiane Schmalz; Moreira, Angélica Cristiane; Oliveira, Karla Renata de

2012-01-01

Diseases of the circulatory system are a principal cause of mortality in Brazil. Using as a basis drugs dispensed through Brazil's Popular Pharmacy Program (FPB, for its name in Portuguese), prices for drugs used to treat circulatory diseases were analyzed to identify the advantages of using generic drugs and the FPB. Drug prices were obtained using Brazil's Pharmacy Price Guide and FPB price tables. The costs of 15 drugs available through the FPB were compared with those of three generic pharmaceutical products, three similar products, and the reference drug. The generic drugs were lower in price for 10 of the drugs and for four of the similar products. The FPB drugs were of the lowest price. Generic and FPB drugs are easily accessed by the population and thus facilitate the continuity of pharmacotherapy when these drugs are not available through the Unified Health System and/or are not affordable through other means. Access to drugs should be taken into consideration at the time prescriptions are filled, especially as regards those used to treat chronic diseases.

Oxygen uptake/oxygen supply dependency: fact or fiction?

PubMed

Vincent, J L; De Backer, D

1995-01-01

More than a decade ago, observations of co-variance between VO2 and DO2 led to the identification of a condition known as pathological O2 supply dependency. This condition was subsequently observed in critically ill patients with sepsis and acute circulatory failure. More recently, other authors have challenged the existence of this condition, often citing methodologic problems or mathematical coupling to account for spurious observations in the earlier studies. Here, we review the evidence for and against pathological O2 supply dependency. We find that many of the arguments have some validity but only in specific circumstances. We conclude, therefore, that pathological O2 supply dependency is a hallmark of acute circulatory failure and that an effective therapeutic approach should be based on an evaluation of organ system function in each individual case. Parameters such as blood lactate, pHi and veno-arterial PCO2 may be useful in this respect.

Intrauterine growth restriction: impact on cardiovascular development and function throughout infancy.

PubMed

Cohen, Emily; Wong, Flora Y; Horne, Rosemary S C; Yiallourou, Stephanie R

2016-06-01

Intrauterine growth restriction (IUGR) refers to the situation where a fetus does not grow according to its genetic growth potential. One of the main causes of IUGR is uteroplacental vascular insufficiency. Under these circumstances of chronic oxygen and nutrient deprivation, the growth-restricted fetus often displays typical circulatory changes, which in part represent adaptations to the suboptimal intrauterine environment. These fetal adaptations aim to preserve oxygen and nutrient supply to vital organs such as the brain, the heart, and the adrenals. These prenatal circulatory adaptations are thought to lead to an altered development of the cardiovascular system and "program" the fetus for life long cardiovascular morbidities. In this review, we discuss the alterations to cardiovascular structure, function, and control that have been observed in growth-restricted fetuses, neonates, and infants following uteroplacental vascular insufficiency. We also discuss the current knowledge on early life surveillance and interventions to prevent progression into chronic disease.

Donation after circulatory death: burying the dead donor rule.

PubMed

Rodríguez-Arias, David; Smith, Maxwell J; Lazar, Neil M

2011-08-01

Despite continuing controversies regarding the vital status of both brain-dead donors and individuals who undergo donation after circulatory death (DCD), respecting the dead donor rule (DDR) remains the standard moral framework for organ procurement. The DDR increases organ supply without jeopardizing trust in transplantation systems, reassuring society that donors will not experience harm during organ procurement. While the assumption that individuals cannot be harmed once they are dead is reasonable in the case of brain-dead protocols, we argue that the DDR is not an acceptable strategy to protect donors from harm in DCD protocols. We propose a threefold alternative to justify organ procurement practices: (1) ensuring that donors are sufficiently protected from harm; (2) ensuring that they are respected through informed consent; and (3) ensuring that society is fully informed of the inherently debatable nature of any criterion to declare death.

Transfusion-Associated Circulatory Overload: Evidence-Based Strategies to Prevent, Identify, and Manage a Serious Adverse Event.

PubMed

Henneman, Elizabeth A; Andrzejewski, Chester; Gawlinski, Anna; McAfee, Kelley; Panaccione, Thomas; Dziel, Kimberly

2017-10-01

Transfusion-associated circulatory overload (TACO) is a potentially life-threatening complication of blood transfusion and is associated with increased morbidity, length of stay (hospital and intensive care unit), and hospital costs. Bedside nurses play a key role in the prevention, identification, and reporting of this complication. A common misperception is that the most frequently encountered serious adverse event during transfusion is a hemolytic reaction in a patient who receives ABO-incompatible blood. In fact, the incidence of TACO-related fatalities is higher than fatalities caused by ABO-related hemolytic reactions. Surveillance and evidence-based strategies such as clinical decision support systems have the potential to reduce the incidence of TACO and mitigate its effects. Practical suggestions for conducting bedside transfusion surveillance and future directions for improving transfusion care are presented. ©2017 American Association of Critical-Care Nurses.

Transfusion-Related Acute Lung Injury (TRALI) and Transfusion-Associated Circulatory Overload (TACO) in Liver Transplantation: A Case Report and Focused Review.

PubMed

Smith, Natalie K; Kim, Sang; Hill, Bryan; Goldberg, Andrew; DeMaria, Samuel; Zerillo, Jeron

2018-06-01

Liver transplantation (LT) is a complex procedure in a patient with multi-organ system dysfunction and coagulation defects. The surgical procedure involves dissection, major vessel manipulation, and pathophysiologic effects of graft storage and reperfusion. As a result, LT frequently involves significant hemorrhage. Subsequent massive transfusion carries high risk of transfusion-associated complications. Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are the leading causes of transfusion associated mortality. In this case report and focused review, we present data that suggest that patients undergoing liver transplantation may be at higher risk for TRALI and TACO than the general population. Anesthesiologists can play a role in decreasing these risks by increasing recognition and reporting of TRALI and TACO, using point of care testing with thromboelastography to guide and decrease transfusion, and considering alternatives to traditional blood products like solvent/detergent plasma.

Demodex canis regulates cholinergic system mediated immunosuppressive pathways in canine demodicosis.

PubMed

Kumari, P; Nigam, R; Singh, A; Nakade, U P; Sharma, A; Garg, S K; Singh, S K

2017-09-01

Demodex canis infestation in dogs remains one of the main challenges in veterinary dermatology. The exact pathogenesis of canine demodicosis is unknown but an aberration in immune status is considered very significant. No studies have underpinned the nexus between induction of demodicosis and neural immunosuppressive pathways so far. We have evaluated the involvement of cholinergic pathways in association with cytokines regulation as an insight into the immuno-pathogenesis of canine demodicosis in the present study. Remarkable elevations in circulatory immunosuppressive cytokine interleukin-10 and cholinesterase activity were observed in dogs with demodicosis. Simultaneously, remarkable reduction in circulatory pro-inflammatory cytokine tumour necrosis factor-alpha level was observed in dogs with demodicosis. Findings of the present study evidently suggest that Demodex mites might be affecting the cholinergic pathways to induce immunosuppression in their host and then proliferate incessantly in skin microenvironment to cause demodicosis.

Environmental Impact Analysis Process. Environmental Impact Statement, Flight Operations in the Sells Airspace Overlying the Tohono O’Odham Indian Reservation & Organ Pipe Cactus National Monument, Southern Arizona. Revised Draft

DTIC Science & Technology

1986-06-06

farm animals (horses, beef cattle, turkeys, broilers , sheep, dairy cattle and pheasants) at Edwards AFB during 1966 show, except for avian species...15 15 loss of hearing, effects on mental health, effects on the circulatory system such as hypertension, digestive system problems, etc. Invlew of the

Intraoperative care for aortic surgery using circulatory arrest

PubMed Central

Fernández Del Valle, David; González Alvarez, Adrián; Pérez-Lozano, Blanca

2017-01-01

The total circulatory arrest (CA) is necessary to achieve optimal surgical conditions in certain aortic pathologies, especially in those affecting the ascending aorta and aortic arch. During this procedure it is necessary to protect all the organs of ischemia, especially those of the central nervous system and for this purpose several strategies have been developed. The first and most important protective method is systemic hypothermia. The degree of hypothermia and the route of application have been evolving and currently tend to use moderate hypothermia (MH) (20.1–28 °C) associated with unilateral or bilateral selective cerebral perfusion methods. In this way the neurological results are better, the interval of security is greater and the times of extracorporeal circulation are smaller. Even so, it is necessary to take into account that there is the possibility of ischemia in the lower part of the body, especially of the abdominal viscera and the spinal cord, therefore the time of circulatory stop should be limited and not to exceed 80 minutes. Evidence of possible neurological drug protection is very weak and only mannitol, magnesium, and statins can produce some benefit. Inhalational anesthetics and some intravenous seem to have advantages, but more studies would be needed to test their long-term benefit. Other important parameters to be monitored during these procedures are blood glucose, anemia and coagulation disorders and acid-base balance. The recommended monitoring is common in complex cardiovascular procedures and it is of special importance the neurological monitoring that can be performed with several techniques, although currently the most used are Bispectral Index (BIS) and Near-Infrared Spectroscopy (NIRS). It is also essential to monitor the temperature routinely at the nasopharyngeal and bladder level and it is important to control coagulation with rotational thromboelastometry (ROTEM). PMID:28616347

Circulatory Estrogen Level Protects Against Breast Cancer in Obese Women

PubMed Central

Suba, Zsuzsanna

2013-01-01

Literary data suggest apparently ambiguous interaction between menopausal status and obesity-associated breast cancer risk based on the principle of the carcinogenic capacity of estrogen. Before menopause, breast cancer incidence is relatively low and adiposity is erroneously regarded as a protective factor against this tumor conferred by the obesity associated defective estrogen-synthesis. By contrast, in postmenopausal cases, obesity presents a strong risk factor for breast cancer being mistakenly attributed to the presumed excessive estrogen-production of their adipose-tissue mass. Obesity is associated with dysmetabolism and endangers the healthy equilibrium of sexual hormone-production and regular menstrual cycles in women, which are the prerequisites not only for reproductive capacity but also for somatic health. At the same time, literary data support that anovulatory infertility is a very strong risk for breast cancer in young women either with or without obesity. In the majority of premenopausal women, obesity associated insulin resistance is moderate and may be counteracted by their preserved circulatory estrogen level. Consequently, it is not obesity but rather the still sufficient estrogen-level, which may be protective against breast cancer in young adult females. In obese older women, never using hormone replacement therapy (HRT) the breast cancer risk is high, which is associated with their continuous estrogen loss and increasing insulin-resistance. By contrast, obese postmenopausal women using HRT, have a decreased risk for breast cancer as the protective effect of estrogen-substitution may counteract to their obesity associated systemic alterations. The revealed inverse correlation between circulatory estrogen-level and breast cancer risk in obese women should advance our understanding of breast cancer etiology and promotes primary prevention measures. New patents recommend various methods for the prevention and treatment of obesity-related systemic disorders and the associated breast cancer. PMID:23061769

Current risks of HeartMate II pump thrombosis: Non-parametric analysis of Interagency Registry for Mechanically Assisted Circulatory Support data.

PubMed

Smedira, Nicholas G; Blackstone, Eugene H; Ehrlinger, John; Thuita, Lucy; Pierce, Christopher D; Moazami, Nader; Starling, Randall C

2015-12-01

Data from 3 institutions revealed an abrupt increase in HeartMate II (Thoratec) pump thrombosis starting in 2011, associated with 48% mortality at 6 months without transplantation or pump exchange. We sought to discover if the increase occurred nationwide in Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data, and if so (1) determine if accelerated risk continued, (2) identify predictors, (3) investigate institutional variability, and (4) assess mortality after pump thrombosis. From April 2008 to June 2014, 11,123 HeartMate II devices were implanted at 146 institutions. Machine learning, non-parametric Random Forests for Survival was used to explore risk-adjusted thrombosis based on 87 pre-implant and implant variables, including implant date. A total of 995 pumps thrombosed, with risk peaking within weeks of implant. The risk-adjusted increase in pump thrombosis began in 2010, reached a maximum in 2012, and then plateaued at a level that was 3.3-times higher than pre-2010. Pump exchange, younger age, and larger body mass index were important predictors, and institutional variability was largely explained by implant date, patient profile, and duration of support. The probability of death within 3 months after pump thrombosis was 24%. Accelerated risk of HeartMate II thrombosis was confirmed by Interagency Registry for Mechanically Assisted Circulatory Support data, with risk subsequently leveling at a risk-adjusted rate higher than observed pre-2010. This elevated thrombosis risk emphasizes the need for improved mechanical circulatory support systems and post-market surveillance of adverse events. Clinicians cognizant of these new data should incorporate them into their and their patients' expectations and understanding of risks relative to those of transplantation and continued medical therapy. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Hybrid model analysis of intra-aortic balloon pump performance as a function of ventricular and circulatory parameters.

PubMed

Ferrari, Gianfranco; Khir, Ashraf W; Fresiello, Libera; Di Molfetta, Arianna; Kozarski, Maciej

2011-09-01

We investigated the effects of the intra-aortic balloon pump (IABP) on endocardial viability ratio (EVR), cardiac output (CO), end-systolic (V(es)) and end-diastolic (V(ed)) ventricular volumes, total coronary blood flow (TCBF), and ventricular energetics (external work [EW], pressure-volume area [PVA]) under different ventricular (E(max) and diastolic stiffness) and circulatory (arterial compliance) parameters. We derived a hybrid model from a computational model, which is based on merging computational and hydraulic submodels. The lumped parameter computational submodel consists of left and right hearts and systemic, pulmonary, and coronary circulations. The hydraulic submodel includes part of the systemic arterial circulation, essentially a silicone rubber tube representing the aorta, which contains a 40-mL IAB. EVR, CO, V(es), and V(ed), TCBF and ventricular energetics (EW, PVA) were analyzed against the ranges of left ventricular E(max) (0.3-0.5-1 mm Hg/cm(3)) and diastolic stiffness V(stiffness) (≈0.08 and ≈0.3 mm Hg/cm(3), obtained by changing diastolic stiffness constant) and systemic arterial compliance (1.8-2.5 cm(3)/mm Hg). All experiments were performed comparing the selected variables before and during IABP assistance. Increasing E(maxl) from 0.5 to 2 mm Hg/cm(3) resulted in IABP assistance producing lower percentage changes in the selected variables. The changes in ventricular diastolic stiffness strongly influence both absolute value of EVR and its variations during IABP (71 and 65% for lower and higher arterial compliance, respectively). V(ed) and V(es) changes are rather small but higher for lower E(max) and higher V(stiffness). Lower E(max) and higher V(stiffness) resulted in higher TCBF and CO during IABP assistance (∼35 and 10%, respectively). The use of this hybrid model allows for testing real devices in realistic, stable, and repeatable circulatory conditions. Specifically, the presented results show that IABP performance is dependent, at least in part, on left ventricular filling, ejection characteristics, and arterial compliance. It is possible in this way to simulate patient-specific conditions and predict the IABP performance at different values of the circulatory or ventricular parameters. Further work is required to study the conditions for heart recovery modeling, baroreceptor controls, and physiological feedbacks. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

The physiology of dinosaurs: circulatory and respiratory function in the largest animals ever to walk the earth.

PubMed

Pierson, David J

2009-07-01

The cardiopulmonary physiology of dinosaurs-and especially of the long-necked sauropods, which grew much larger than any land animals before or since-should be inherently fascinating to anyone involved in respiratory care. What would the blood pressure be in an animal 12 m (40 ft) tall? How could airway resistance and dead space be overcome while breathing through a trachea 9 m (30 ft) long? The last decade has seen a dramatic increase in evidence bearing on these questions. Insight has come not only from new fossil discoveries but also from comparative studies of living species, clarification of evolutionary relationships, new evaluation techniques, computer modeling, and discoveries about the earth's ancient atmosphere. Pumping a vertical column of blood 8 m (26 ft) above the heart would probably require an arterial blood pressure > 600 mm Hg, and the implications of this for cardiac size and function have led to the proposal of several alternative cardiopulmonary designs. Diverse lines of evidence suggest that the giant sauropods were probably warm-blooded and metabolically active when young, but slowed their metabolism as they approached adult size, which diminished the load on the circulatory system. Circulatory considerations leave little doubt that the dinosaurs had 4-chambered hearts. Birds evolved from dinosaurs, and the avian-type air-sac respiratory system, which is more efficient than its mammalian counterpart, may hold the answer to the breathing problems posed by the sauropods' very long necks. Geochemical and other data indicate that, at the time the dinosaurs first appeared, the atmospheric oxygen concentration was only about half of what it is today, and development of the avian-type respiratory system may have been key in the dinosaurs' evolutionary success, enabling them to out-compete the mammals and dominate the land for 150 million years.

Theological reflections on donation after circulatory death: the wisdom of Paul Ramsey and Moshe Feinstein.

PubMed

Jotkowitz, A

2008-10-01

Due to the worldwide shortage of organs for transplantation, there has been an increased use of organs obtained after circulatory death alone. A protocol for this procedure has recently been approved by a major transplant consortium. This development raises serious moral and ethical concerns. Two renowned theologians of the previous generation, Paul Ramsey and Moshe Feinstein, wrote extensively on the ethical issues relating to transplantation, and their work has much relevance to current moral dilemmas. Their writings relating to definition of death, organ transplantation and the care of the terminally ill are briefly presented, and their potential application to the moral problem of organ donation after circulatory death is discussed.

Physiological system integrations with emphasis on the respiratory-cardiovascular system

NASA Technical Reports Server (NTRS)

Gallagher, R. R.

1975-01-01

The integration of two types of physiological system simulations is presented. The long term model is a circulatory system model which simulates long term blood flow variations and compartmental fluid shifts. The short term models simulate transient phenomena of the respiratory, thermoregulatory, and pulsatile cardiovascular systems as they respond to stimuli such as LBNP, exercise, and environmental gaseous variations. An overview of the interfacing approach is described. Descriptions of the variable interface for long term to short term and between the three short term models are given.

Effect of Panpal pretreatment and antidotal treatment (HI-6 plus benactyzine) on respiratory and circulatory function in soman-poisoned rats.

PubMed

Kassa, J; Fusek, J

1997-10-01

1 The effect of pharmacological pretreatment (pyridostigmine, benactyzine and trihexyphenidyle), designated Panpal, and antidotal treatment (the oxime HI-6 plus benactyzine) in soman poisoning was investigated in a rat model with on-line monitoring of respiratory and circulatory parameters. 2 Soman poisoning caused a high decrease in respiratory rate as well as minute respiratory volume and an increase in mean arterial pressure from 30-120 min following soman challenge. Soman at sublethal dose also significantly inhibited acetylcholinesterase activity in diaphragm and various brain parts. 3 Panpal pretreatment as well as antidotal treatment were effective in improving the respiratory and circulatory function disturbed by soman without the ability to increase significantly soman-inhibited acetylcholinesterase activity in all brain parts studied. 4 The efficacy of combined Panpal pretreatment and antidotal treatment against sublethal soman poisoning was not different from the efficacy of Panpal pretreatment or antidotal treatment alone. 5 The results of this investigation suggest that Panpal pretreatment as well as antidotal treatment are able to restore respiratory and circulatory function in soman-poisoned rats without significant reactivation of brain acetylcholinesterase.

Hyperhomocysteinemia impairs regional blood flow: involvements of endothelial and neuronal nitric oxide.

PubMed

Toda, Noboru; Okamura, Tomio

2016-09-01

Increasing evidence support the idea that hyperhomocysteinemia (HHcy) is responsible for pathogenesis underlying cerebral, coronary, renal, and other vascular circulatory disorders and for hypertension. Impaired synthesis of nitric oxide (NO) in the endothelium or increased production of asymmetric dimethylarginine and activated oxygen species are involved in the impairment of vasodilator effects of NO. Impaired circulation in the brain derived from reduced synthesis and actions of NO would be an important triggering factor to dementia and Alzheimer's disease. Reduced actions of NO and brain hypoperfusion trigger increased production of amyloid-β that inhibits endothelial function, thus establishing a vicious cycle for impairing brain circulation. HHcy is involved in the genesis of anginal attack and coronary myocardial infarction. HHcy is also involved in renal circulatory diseases. The homocysteine (Hcy)-induced circulatory failure is promoted by methionine and is prevented by increased folic acid and vitamin B6/B12. Eliminating poor life styles, such as smoking and being sedentary; keeping favorable dietary habits; and early treatment maintaining constitutive NOS functions healthy, reducing oxidative stresses would be beneficial in protecting HHcy-induced circulatory failures.

Belgian modified classification of Maastricht for donors after circulatory death.

PubMed

Evrard, P

2014-11-01

"Non-heart-beating donors," or, in a more recent and international definition, "donors after circulatory death," are a potential and additional group of deceased persons who are able to add organs to the pool. A new classification is proposed on the basis of the result of a consensus of experts issued from all Belgian transplant centers. The first level of definition is simple and based on whether the situation is uncontrolled (categories I and II) or controlled (categories III, IV, and V). In category I, the patient is declared "dead on arrival" and, in category II, there is an "unsuccessful resuscitation" whether it occurred out or in the hospital for both situations. Category III is the most usual situation in which the treating physician and family are "awaiting cardiac arrest" to declare the death of the patient. Category IV is always characterized by "cardiac arrest during brain death." The special situation of the Belgian law allowing the euthanasia is elaborated in category V, "euthanasia," and includes patients who grant access to medically assisted circulatory death. Organ donation after euthanasia is allowed under the scope of donation after circulatory death. This classification conserves the skeleton of the Maastricht one, as it is simple and clear, but classifies easily the different donors after circulatory death types by processes for ethical issues and for the non-medical or non-specialized reader interested in the field. This is also an argument for public consideration and trust in the difficult field of organ donation.

[Morbidity among forestry workers].

PubMed

Rafalski, H; Bernacki, K

1981-01-01

The past and presently diagnosed diseases (excluding vibration disease and occupational hearing impairment) were analysed in 1105 sawers operating combustion drive mechanic saws and in 295 controls. The greatest rate, both in the sawers and controls, was that of the diseases of respiratory tract, circulatory system and osseo -- articulo -- muscular system, nervous system and sense organs. These constituted 86% of all diseases that afflicted sawers and controls. No specific general morbidity accompanying vibration disease or occupational hearing impairment was found in the sawers exposed to noise and vibration.

An Evaluation of the Elbit Canary and DynaSense PocketNIRS In-Flight Physiological Monitoring Systems

DTIC Science & Technology

2017-01-04

you have normal pulmonary function? YES NO 6. Have you ever been diagnosed with heart /circulatory disease ? YES NO 7. Do you...total dropout, the Canary system occasionally exhibited long stretches of data with sporadic heart rate signal dropout accompanied by high variance...values as low as 86%. This occurs over a timespan with sporadic heart rate signal dropout and greater mismatch between Canary and Ohmeda HR

Ultrasonic Doppler measurement of renal artery blood flow

NASA Technical Reports Server (NTRS)

Freund, W. R.; Meindl, J. D.

1975-01-01

An extensive evaluation of the practical and theoretical limitations encountered in the use of totally implantable CW Doppler flowmeters is provided. Theoretical analyses, computer models, in-vitro and in-vivo calibration studies describe the sources and magnitudes of potential errors in the measurement of blood flow through the renal artery, as well as larger vessels in the circulatory system. The evaluation of new flowmeter/transducer systems and their use in physiological investigations is reported.

77 FR 18829 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-28

... rare life-threatening events to more common events that are perceived to have less severe clinical sequelae. Many of these events were evident in the premarket studies; however, rare events such as erosion... events in the overall context of the disease and existing treatment options; (2) to discuss whether...

21 CFR 101.75 - Health claims: dietary saturated fat and cholesterol and risk of coronary heart disease.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of coronary heart disease. (1) Cardiovascular disease means diseases of the heart and circulatory system. Coronary heart disease is the most common and serious form of cardiovascular disease and refers... cholesterol and risk of coronary heart disease. 101.75 Section 101.75 Food and Drugs FOOD AND DRUG...

21 CFR 101.83 - Health claims: plant sterol/stanol esters and risk of coronary heart disease (CHD).

Code of Federal Regulations, 2010 CFR

2010-04-01

.... (1) Cardiovascular disease means diseases of the heart and circulatory system. Coronary heart disease (CHD) is one of the most common and serious forms of cardiovascular disease and refers to diseases of... of coronary heart disease (CHD). 101.83 Section 101.83 Food and Drugs FOOD AND DRUG ADMINISTRATION...

21 CFR 101.82 - Health claims: Soy protein and risk of coronary heart disease (CHD).

Code of Federal Regulations, 2010 CFR

2010-04-01

... risk of CHD. (1) Cardiovascular disease means diseases of the heart and circulatory system. CHD is one of the most common and serious forms of cardiovascular disease and refers to diseases of the heart... heart disease (CHD). 101.82 Section 101.82 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...

The Temporal and Dynamic Nature of Self-Regulatory Processes during Independent and Externally Assisted Hypermedia Learning

ERIC Educational Resources Information Center

Johnson, Amy M.; Azevedo, Roger; D'Mello, Sidney K.

2011-01-01

This study examined the temporal and dynamic nature of students' self-regulatory processes while learning about the circulatory system with hypermedia. A total of 74 undergraduate students were randomly assigned to 1 of 2 conditions: independent learning or externally assisted learning. Participants in the independent learning condition used a…

Why Is Externally-Facilitated Regulated Learning More Effective than Self-Regulated Learning with Hypermedia?

ERIC Educational Resources Information Center

Azevedo, Roger; Moos, Daniel C.; Greene, Jeffrey A.; Winters, Fielding I.; Cromley, Jennifer G.

2008-01-01

We examined how self-regulated learning (SRL) and externally-facilitated self-regulated learning (ERL) differentially affected adolescents' learning about the circulatory system while using hypermedia. A total of 128 middle-school and high school students with little prior knowledge of the topic were randomly assigned to either the SRL or ERL…

Adaptive, Active and Multifunctional Composite and Hybrid Materials Program: Composite and Hybrid Materials ERA

DTIC Science & Technology

2014-04-01

Microvascular Self - Healing Composites Mechanical Evaluation ................................................................................11...Thermoplastic SMP Foam Microstructure- Mechanical Stress-Strain Relationships 2.2.2 Microvascular Self - Healing Composites Mechanical Evaluation 2.3.1 Z...materials, and embedded sensory and circulatory systems. Damage repair of torn or injured tissue was demonstrated by the use of self - healing polymer

Clinical Assessment of the RHUMART System Based on the Use of Pulsed Electromagnetic Fields with Low Frequency.

ERIC Educational Resources Information Center

Begue-Simon, A-M.; Drolet, R. A.

1993-01-01

Difficulties in using the double-blind method of evaluation with use of Pulsed Electromagnetic Fields led to an open evaluation with 96 patients with musculoskeletal diseases, neurological disorders, circulatory diseases, or gastroenterological diseases. This paper reports the impact of use on dependency, pain, and patient satisfaction. (DB)

Switching wormlike micelles of selenium-containing surfactant using redox reaction.

PubMed

Zhang, Yongmin; Kong, Weiwei; Wang, Cheng; An, Pengyun; Fang, Yun; Feng, Yujun; Qin, Zhirong; Liu, Xuefeng

2015-10-14

A novel redox-switchable wormlike micellar system was developed based on a mixture of selenium-containing zwitterionic surfactant and commercially available anionic surfactant sodium dodecyl sulfate, which reversibly and quickly responds to H2O2 and vitamin C, and shows circulatory gel/sol transition, reflecting changes in aggregate morphology from entangled worms to vesicles.

75 FR 81282 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-27

... symptoms and >50 percent stenosis of the common or internal carotid artery or patients without neurological symptoms and >80 percent (high risk) or >70 percent (standard risk) stenosis of the common or internal.... If the number of registrants requesting to speak is greater than can be reasonably accommodated...

Experimental evidence for killing the resistant cells and raising the efficacy and decreasing the toxicity of cytostatics and irradiation by mixtures of the agents of the passive antitumor defense system in the case of various tumor and normal cell lines in vitro.

PubMed

Kulcsár, Gyula

2009-02-01

Despite the substantial decline of the immune system in AIDS, only a few kinds of tumors increase in incidence. This shows that the immune system has no absolute role in the prevention of tumors. Therefore, the fact that tumors do not develop in the majority of the population during their lifetime indicates the existence of other defense system(s). According to our hypothesis, the defense is made by certain substances of the circulatory system. Earlier, on the basis of this hypothesis, we experimentally selected 16 substances of the circulatory system and demonstrated that the mixture of them (called active mixture) had a cytotoxic effect (inducing apoptosis) in vitro and in vivo on different tumor cell lines, but not on normal cells and animals. In this paper, we provide evidence that different cytostatic drugs or irradiation in combination with the active mixture killed significantly more cancer cells, compared with either treatments alone. The active mixture decreased, to a certain extent, the toxicity of cytostatics and irradiation on normal cells, but the most important result was that the active mixture destroyed the multidrug-resistant cells. Our results provide the possibility to improve the efficacy and reduce the side-effects of chemotherapy and radiation therapy and to prevent the relapse by killing the resistant cells.

[Pulmonary thromboendarterectomy].

PubMed

Lausberg, H F; Tscholl, D; Schäfers, H-J

2004-08-01

Chronic thromboembolic pulmonary hypertension with concomitant right heart failure may develop as a sequela of acute pulmonary embolism with organization instead of thrombolysis of intravascular clots. Medical therapy aims at prevention of recurrent embolism by anticoagulation and vascular remodelling using vasodilator therapy. Lung transplantation or combined heart-lung transplantation is associated with unsatisfactory long-term results and comorbidity and therefore remains justified only in selected patients. Pulmonary thromboendarterectomy allows specific treatment of intravascular obstruction. This closed endarterectomy of the pulmonary arteries requires deep hypothermic circulatory arrest and can be performed with a perioperative mortality of less than 10%. The procedure significantly decreases pulmonary vascular resistance and often normalizes pulmonary hemodynamics and gas exchange. Postoperatively the patients' clinical condition improves and the majority have normal exercise capacity and activity.

9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

Code of Federal Regulations, 2010 CFR

2010-01-01

... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected, the...

9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

Code of Federal Regulations, 2011 CFR

2011-01-01

... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected, the...

9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

Code of Federal Regulations, 2014 CFR

2014-01-01

... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected, the...

9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

Code of Federal Regulations, 2013 CFR

2013-01-01

... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected, the...

9 CFR 309.4 - Livestock showing symptoms of certain metabolic, toxic, nervous, or circulatory disturbances...

Code of Federal Regulations, 2012 CFR

2012-01-01

... diseases. 309.4 Section 309.4 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., toxic, nervous, or circulatory disturbances, nutritional imbalances, or infectious or parasitic diseases... the animal is, in fact, infected with such disease. If it is found on such tests to be infected, the...

Mechanical circulatory support in pediatrics.

PubMed

Steffen, Robert J; Miletic, Kyle G; Schraufnagel, Dean P; Vargo, Patrick R; Fukamachi, Kiyotaka; Stewart, Robert D; Moazami, Nader

2016-05-01

End-stage heart failure affects thousands of children yearly and mechanical circulatory support is used at many points in their care. Extracorporeal membrane oxygenation supports both the failing heart and lungs, which has led to its use as an adjunct to cardiopulmonary resuscitation as well as in post-operative cardiogenic shock. Continuous-flow ventricular assist devices (VAD) have replaced pulsatile-flow devices in adults and early studies have shown promising results in children. The Berlin paracorporeal pulsatile VAD recently gained U.S. Food and Drug Administration approval and remains the only VAD approved in pediatrics. Failing univentricular hearts and other congenitally corrected lesions are new areas for mechanical support. Finding novel uses, improving durability, and minimizing complications are areas of growth in pediatric mechanical circulatory support.

Latin American Consensus on the use of transcranial Doppler in the diagnosis of brain death

PubMed Central

2014-01-01

Transcranial Doppler evaluates cerebral hemodynamics in patients with brain injury and is a useful technical tool in diagnosing cerebral circulatory arrest, usually present in the brain-dead patient. This Latin American Consensus was formed by a group of 26 physicians experienced in the use of transcranial Doppler in the context of brain death. The purpose of this agreement was to make recommendations regarding the indications, technique, and interpretation of the study of transcranial ultrasonography in patients with a clinical diagnosis of brain death or in the patient whose clinical diagnosis presents difficulties; a working group was formed to enable further knowledge and to strengthen ties between Latin American physicians working on the same topic. A review of the literature, concepts, and experiences were exchanged in two meetings and via the Internet. Questions about pathophysiology, equipment, techniques, findings, common problems, and the interpretation of transcranial Doppler in the context of brain death were answered. The basic consensus statements are the following: cerebral circulatory arrest is the final stage in the evolution of progressive intracranial hypertension, which is visualized with transcranial Doppler as a "pattern of cerebral circulatory arrest". The following are accepted as the standard of cerebral circulatory arrest: reverberant pattern, systolic spikes, and absence of previously demonstrated flow. Ultrasonography should be used - in acceptable hemodynamic conditions - in the anterior circulation bilaterally (middle cerebral artery) and in the posterior (basilar artery) territory. If no ultrasonographic images are found in any or all of these vessels, their proximal arteries are acceptable to be studied to look for a a pattern of cerebral circulatory arrest. PMID:25295818

Cardiorespiratory interactions previously identified as mammalian are present in the primitive lungfish

PubMed Central

Monteiro, Diana A.; Taylor, Edwin W.; Sartori, Marina R.; Cruz, André L.; Rantin, Francisco T.; Leite, Cleo A. C.

2018-01-01

The present study has revealed that the lungfish has both structural and functional features of its system for physiological control of heart rate, previously considered solely mammalian, that together generate variability (HRV). Ultrastructural and electrophysiological investigation revealed that the nerves connecting the brain to the heart are myelinated, conferring rapid conduction velocities, comparable to mammalian fibers that generate instantaneous changes in heart rate at the onset of each air breath. These respiration-related changes in beat-to-beat cardiac intervals were detected by complex analysis of HRV and shown to maximize oxygen uptake per breath, a causal relationship never conclusively demonstrated in mammals. Cardiac vagal preganglionic neurons, responsible for controlling heart rate via the parasympathetic vagus nerve, were shown to have multiple locations, chiefly within the dorsal vagal motor nucleus that may enable interactive control of the circulatory and respiratory systems, similar to that described for tetrapods. The present illustration of an apparently highly evolved control system for HRV in a fish with a proven ancient lineage, based on paleontological, morphological, and recent genetic evidence, questions much of the anthropocentric thinking implied by some mammalian physiologists and encouraged by many psychobiologists. It is possible that some characteristics of mammalian respiratory sinus arrhythmia, for which functional roles have been sought, are evolutionary relics that had their physiological role defined in ancient representatives of the vertebrates with undivided circulatory systems. PMID:29507882

Cardiorespiratory interactions previously identified as mammalian are present in the primitive lungfish.

PubMed

Monteiro, Diana A; Taylor, Edwin W; Sartori, Marina R; Cruz, André L; Rantin, Francisco T; Leite, Cleo A C

2018-02-01

The present study has revealed that the lungfish has both structural and functional features of its system for physiological control of heart rate, previously considered solely mammalian, that together generate variability (HRV). Ultrastructural and electrophysiological investigation revealed that the nerves connecting the brain to the heart are myelinated, conferring rapid conduction velocities, comparable to mammalian fibers that generate instantaneous changes in heart rate at the onset of each air breath. These respiration-related changes in beat-to-beat cardiac intervals were detected by complex analysis of HRV and shown to maximize oxygen uptake per breath, a causal relationship never conclusively demonstrated in mammals. Cardiac vagal preganglionic neurons, responsible for controlling heart rate via the parasympathetic vagus nerve, were shown to have multiple locations, chiefly within the dorsal vagal motor nucleus that may enable interactive control of the circulatory and respiratory systems, similar to that described for tetrapods. The present illustration of an apparently highly evolved control system for HRV in a fish with a proven ancient lineage, based on paleontological, morphological, and recent genetic evidence, questions much of the anthropocentric thinking implied by some mammalian physiologists and encouraged by many psychobiologists. It is possible that some characteristics of mammalian respiratory sinus arrhythmia, for which functional roles have been sought, are evolutionary relics that had their physiological role defined in ancient representatives of the vertebrates with undivided circulatory systems.

The risk characteristics of solar and geomagnetic activity

NASA Astrophysics Data System (ADS)

Podolska, Katerina

2016-04-01

The main aim of this contribution is a deeper analysis of the influence of solar activity which is expected to have an impact on human health, and therefore on mortality, in particular civilization and degenerative diseases. We have constructed the characteristics that represent the risk of solar and geomagnetic activity on human health on the basis of our previous analysis of association between the daily numbers of death on diseases of the nervous system and diseases of the circulatory system and solar and geomagnetic activity in the Czech Republic during the years 1994 - 2013. We used long period daily time series of numbers of deaths by cause, long period time series of solar activity indices (namely R and F10.7), geomagnetic indicies (Kp planetary index, Dst) and ionospheric parameters (foF2 and TEC). The ionospheric parameters were related to the geographic location of the Czech Republic and adjusted for middle geographic latitudes. The risk characteristics were composed by cluster analysis in time series according to the phases of the solar cycle resp. the seasonal insolation at mid-latitudes or the daily period according to the impact of solar and geomagnetic activity on mortality by cause of death from medical cause groups of death VI. Diseases of the nervous system and IX. Diseases of the circulatory system mortality by 10th Revision of International Classification of Diseases WHO (ICD-10).

Minimal alteration in the ratio of circulatory fetal DNA to fetal corticotropin-releasing hormone mRNA level in preeclampsia.

PubMed

Zhong, Xiao Yan; Holzgreve, Wolfgang; Gebhardt, Stefan; Hillermann, Renate; Tofa, Kashefa Carelse; Gupta, Anurag Kumar; Huppertz, Berthold; Hahn, Sinuhe

2006-01-01

We have recently observed that fetal DNA and fetal corticotropin-releasing hormone (CRH) mRNA are associated with in vitro generated syncytiotrophoblast-derived microparticles, and that the ratio of fetal DNA to mRNA (CRH) varied according to whether the particles were derived by predominantly apoptotic, apo-necrotic or necrotic pathways. Hence, we examined whether these ratios varied in maternal plasma samples taken from normotensive and preeclamptic pregnancies in vivo. Maternal plasma samples were collected from 18 cases with preeclampsia and 29 normotensive term controls. Circulatory fetal CRH mRNA and DNA levels were quantified by real-time PCR and RT-PCR. Circulatory fetal mRNA and fetal DNA levels were significantly elevated in the preeclampsia study group when compared to normotensive controls. Alterations in the fetal mRNA to DNA ratio between the study and control groups were minimal, even when stratified into early (<34 weeks of gestation) and late (>34 weeks of gestation) onset preeclampsia. Our data suggest that although circulatory fetal DNA and mRNA levels are significantly elevated in preeclampsia, the ratios in maternal plasma are not dramatically altered. Copyright 2006 S. Karger AG, Basel.

Using the brain criterion in organ donation after the circulatory determination of death.

PubMed

Dalle Ave, Anne L; Bernat, James L

2016-06-01

The UK, France, and Switzerland determine death using the brain criterion even in organ donation after the circulatory determination of death (DCDD), in which the United States and Canada use the circulatory-respiratory criterion. In our analysis of the scientific validity of the brain criterion in DCDD, we concluded that although it may be attractive in theory because it conceptualizes death as a unitary phenomenon, its use in practice is invalid. The preconditions (ie, the absence of reversible causes, such as toxic or metabolic disorders) for determining brain death cannot be met in DCDD. Thus, although brain death tests prove the cessation of tested brain functions, they do not prove that their cessation is irreversible. A stand-off period of 5 to 10 minutes is insufficient to achieve the irreversibility requirement of brain death. Because circulatory cessation inevitably leads to cessation of brain functions, first permanently and then irreversibly, the use of brain criterion is unnecessary to determine death in DCDD. Expanding brain death to permit it to be satisfied by permanent cessation of brain functions is controversial but has been considered as a possible means to declare death in uncontrolled DCDD. Copyright © 2016 Elsevier Inc. All rights reserved.

Emerging role of neurotensin in regulation of the cardiovascular system.

PubMed

Osadchii, Oleg E

2015-09-05

There is increasing evidence in support of an important role played by neurotensin (NT), a tridecapeptide originally found in bovine hypothalamus, in regulation of cardiovascular system. Elevated systemic levels of NT may contribute to pathogenesis of acute circulatory disoders, and predict the risk for cardiovascular morbidity and mortality in population-based studies. Within cardiovascular system, NT-containing neural fibers are found in close contact with atrial and ventricular cardiac myocytes, cardiac conduction system, intracardiac ganglia, as well as coronary vessels in humans and various animal species. The density of NT-immunoreactive innervation is reduced in cardiac disease. NT produces a variety of cardiovascular actions including effects on heart rate, myocardial contractility, systemic blood pressure, coronary vascular tone, venous smooth muscle tone, and regional blood flow in gastrointestinal tract, cutaneous and adipose tissue. NT could trigger cardiovascular reflexes by stimulating primary visceral afferents synaptically connected with preganglionic sympathetic neurons at the spinal cord. Structural determinants of biological activity of NT reside primarily in the C-terminal portion of its molecule which is responsible for receptor activation. NT effects are mediated via activation of NT receptors, or produced indirectly via stimulation of release of various endogenous neuromodulators/neurotransmitters such as histamine, catecholamines and prostaglandins. Three subtypes of NT receptor (NTS1, NTS2 and NTS3) have been shown to be expressed in the myocardium. NTS1, a high-affinity NT binding site coupled to phospholipase C-inositoltrisphosphate transduction pathway, is thought to mediate NT-induced cardiovascular responses. Copyright © 2015 Elsevier B.V. All rights reserved.

76 FR 56200 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-12

... Stent. The ZILVER-PTX Stent is a self-expanding nitinol stent coated on its outer surface with the... millimeter. The ZILVER-PTX Stent is available in diameters ranging from 5 to 10 millimeters (mm) and lengths... deployment, the ZILVER-PTX Stent expands to establish and maintain patency in the stented region. The...

78 FR 11208 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-15

... who have been determined by a cardiac surgeon to be too high risk for open mitral valve surgery and in... submissions may be made to the contact person on or before March 13, 2013. Oral presentations from the public... interested in making formal oral presentations should notify the contact person and submit a brief statement...

Microgravity

NASA Image and Video Library

1989-02-03

(PCG) Protein Crystal Growth Human Serum Albumin. Contributes to many transport and regulatory processes and has multifunctional binding properties which range from various metals, to fatty acids, hormones, and a wide spectrum of therapeutic drugs. The most abundant protein of the circulatory system. It binds and transports an incredible variety of biological and pharmaceutical ligands throughout the blood stream. Principal Investigator on STS-26 was Larry DeLucas.

Biomedical technology transfer: Bioinstrumentation for cardiology, neurology, and the circulatory system

NASA Technical Reports Server (NTRS)

1976-01-01

Developments in applying aerospace medical technology to the design and production of medical equipment and instrumentation are reported. Projects described include intercranial pressure transducers, leg negative pressure devices, a synthetic speech prosthesis for victims of cerebral palsy, and a Doppler blood flow instrument. Commercialization activities for disseminating and utilizing NASA technology, and new biomedical problem areas are discussed.

Recognition and Emergency Care of Wounds: Bleeding Control and Bandaging. First Responder Training, Lesson Plan No. 1.

ERIC Educational Resources Information Center

Upton, Robert

Designed for a 40-hour course in first-responder medical training, this lesson plan teaches students how to control bleeding and bandage wounds. This lesson includes discussions on skin, the circulatory system, and blood; describes seven types of wounds; and explains four bleeding control methods. The lesson plan begins with information on the…

The Most Important Concept of Transport and Circulatory Systems: Turkish Biology Student Teachers' Cognitive Structure

ERIC Educational Resources Information Center

Kurt, Hakan; Ekici, Gulay; Aksu, Ozlem; Aktas, Murat

2013-01-01

The purpose of this study is to determine biology student teachers' cognitive structure with regard to "Blood". Qualitative research method has been used. The free word association test and the draw-write technique have been used in collection of data. The data obtained have been evaluated and divided into categories based on content…

Influence of mianserin on the activity of some hypotensive drugs in spontaneously hypertensive rats.

PubMed

Górska, Dorota; Andrzejczak, Dariusz

2003-01-01

Mianserin might be an alternative drug in patients with depression accompanied by hypertension because of its effectiveness and lack of side effects in the circulatory system. However, a few studies reported in literature show influence of the drug on blood pressure. We investigate interactions between mianserin and commonly used hypotensive drugs (propranolol, enalapril and prazosin) in spontaneously hypertensive rats (SHR). The experiments were performed in two experimental designs: a single administration of both mianserin and a hypotensive drug, and repeated administration of mianserin with a single administration of a hypotensive drug. Arterial blood pressure was measured by bloodless method with manometer made by LETICA. A single administration of mianserin caused a statistically significant decrease in systolic, diastolic and mean blood pressure in the 60th minute of observation and intensified hypotensive effect of prazosin. However, long-term administration of mianserin in SHR rats had no significant influence on arterial blood pressure. Chronic and single administration of mianserin with propranolol or enalapril did not influence the circulatory system. A long-term administration of mianserin intensified the hypotensive effect of prazosin. This interaction might suggest possibility of dangerous complications in the treatment of humans with this drug combination.

[The Contribution of Vascular Capacity and Blood Volume to Maintain Stable Blood Circulation during General Anesthesia].

PubMed

Shigemi, Kenji

2016-05-01

To maintain proper cardiac preload is one of the most effective procedures for the systemic circulation remaining stable. In particular, the balance between vascular capacity and total blood volume must be maintained within appropriate range by the administration of fluids, blood and/or vasoactive drugs with mean circulatory filling pressure (Pmcf), central venous pressure (CVP) or stroke volume variation (SVV). End-diastolic left ventricular volume (Ved) is theoretically the best index of cardiac preload; however, without transesophageal echocardbalanceiogram we cannot directly monitor Ved during anesthesia. The infused fluid volume remaining in intravascular space, the vascular capacity controlled by autonomic nervous system and/or vasoactive agents, and the unstressed blood volume properly mobilized to excess blood volume are the crucial factors to maintain cardiac output The knowledge of vascular physiology contribute the decision making to manipulate such factors to control blood circulation during general anesthesia. For example, CVP is usually maintained in the narrow range and seems to be stable; however, it must be changed just after the circulatory disturbances, such as acute bleeding, blood transfusion, and fluid infusion, and followed by gradual returning to initial value, because of the solid mechanism to preserve cardiac output

Effect of valsalva in the pulmonary prosthetic conduit valve on hemodynamic function in a mock circulatory system.

PubMed

Tsuboko, Yusuke; Shiraishi, Yasuyuki; Yamada, Akihiro; Yambe, Tomoyuki; Matsuo, Satoshi; Saiki, Yoshikatsu; Yamagishi, Masaaki

2015-01-01

Pulmonary conduit valves are used as one of the surgical treatment methods of congenital heart diseases. We have been designing a sophisticated pulmonary conduit valve for the right ventricular outflow tract reconstruction in pediatric patients. In this study, two types of polyester grafts with or without bulging structures for the conduit valves were used and evaluated from the hemodynamic point of view focusing on the application of these conduit valves in the grown-up congenital heart failure patients. We examined valvular function in the originally developed pulmonary mock circulatory system, which consisted of a pneumatic driven right ventricular model, a pulmonary valve chamber, and an elastic pulmonary compliance model with peripheral vascular resistance units. Prior to the measurement, a bileaflet valve was sutured in each conduit. Each conduit valve was installed in the mock right ventricular outflow portion, and its leaflet motion was obtained by using a high-speed camera synchronously with pressure and flow waveforms. As a result, we could obtain hemodynamic changes in two different types of conduits for pulmonary valves, and it was indicated that the presence of the Valsalva shape might be effective for promoting valvular response in the low cardiac output condition.

[Acute novel drugs poisoning among patients of Nofer Institute of Occupational Medicine in Lodz, Toxicology Unit, hospitalized in the years 2008-2012--epidemiology, clinical state].

PubMed

Sawicka, Joanna; Czyzewska, Sylwia; Winnicka, Renata; Politański, Piotr; Swiderska-Kiełbik, Sylwia; Kołaciński, Zbigniew; Czerniak, Paweł; Krakowiak, Anna

2013-01-01

Intoxication with novel recreational drugs poses significant challenge for medical staff due to diagnostic difficulties, complex clinical pattern, resulting from polyethiology of poisoning and potential risk of life threatening complications. Description of clinical pattern novel drug intoxication. retrospective review of medical records patients hospitalized in the Toxicology Unit (TU) with diagnosis of intoxication with novel recreational drugs. During the period from 2008-2010--431 patients were admitted to TU with mentioned above diagnosis. 159 (36.9%) patients were positive for ethanol with its average concentration in blood 150 mg%. Presence of other substances like amphetamine, cannabinoids, atropine, ephedrine, carbamazepine, benzodiazepines and dextrometorphan was confirmed. The most frequent clinical symptoms observed on admission were: anxiety, agitation, complaints associated with circulatory system and vertigo Average pulse rate and both: diastolic and systolic pressure were within normal limits, however authors noted slight tendency toward tachycardia. One patients died due to multiorgan failure. Average period of hospitalization amounted 2.24 days. Co-poisoning with ethanol was associated with higher frequency of circulatory system disturbances. Clinical pattern of poisoning with novel drugs could partially correspond with mild sympathomime. tic syndrome.

Ingested microscopic plastic translocates to the circulatory system of the mussel, Mytilus edulis (L).

PubMed

Browne, Mark A; Dissanayake, Awantha; Galloway, Tamara S; Lowe, David M; Thompson, Richard C

2008-07-01

Plastics debris is accumulating in the environment and is fragmenting into smaller pieces; as it does, the potential for ingestion by animals increases. The consequences of macroplastic debris for wildlife are well documented, however the impacts of microplastic (< 1 mm) are poorly understood. The mussel, Mytilus edulis, was used to investigate ingestion, translocation, and accumulation of this debris. Initial experiments showed that upon ingestion, microplastic accumulated in the gut. Mussels were subsequently exposed to treatments containing seawater and microplastic (3.0 or 9.6 microm). After transfer to clean conditions, microplastic was tracked in the hemolymph. Particles translocated from the gut to the circulatory system within 3 days and persisted for over 48 days. Abundance of microplastic was greatest after 12 days and declined thereafter. Smaller particles were more abundant than larger particles and our data indicate as plastic fragments into smaller particles, the potential for accumulation in the tissues of an organism increases. The short-term pulse exposure used here did not result in significant biological effects. However, plastics are exceedingly durable and so further work using a wider range of organisms, polymers, and periods of exposure will be required to establish the biological consequences of this debris.

Contribution of Circulatory Disturbances in Subchondral Bone to the Pathophysiology of Osteoarthritis.

PubMed

Aaron, Roy K; Racine, Jennifer; Dyke, Jonathan P

2017-08-01

This review describes the contributions of abnormal bone circulation to the pathophysiology of osteoarthritis. Combining dynamic imaging with MRI and PET with previous observations reveals that venous stasis and a venous outlet syndrome is most likely the key circulatory pathology associated with the initiation or progression of osteoarthritis. MRI and PET have revealed that venous outflow obstruction results in physicochemical changes in subchondral bone to which osteoblasts are responsive. The osteoblasts express an altered pattern of cytokines, many of which can serve as structural or signaling molecules contributing to both bone remodeling and cartilage degeneration. The patterns of circulatory changes are associated with alterations in the physicochemical environment of subchondral bone, including hypoxia. Osteoblast cytokines can transit the subchondral bone plate and calcified cartilage and communicate with chondrocytes.

[The disease burden of cardiovascular and circulatory diseases in China, 1990 and 2010].

PubMed

Liu, Jiangmei; Liu, Yunning; Wang, Lijun; Yin, Peng; Liu, Shiwei; You, Jinling; Zeng, Xinying; Zhou, Maigeng

2015-04-01

To analyze the death status of disease burden of cardiovascular and circulatory diseases in 1990 and 2010 in China, and to provide the basic information for cardiovascular and circulatory disease prevention and control. Using the results of the Global Burden of Diseases Study 2010 (GBD 2010) to describe the cardiovascular and circulatory diseases deaths status and disease burden in China. The measurement index included the mortality, years of life lost due to premature mortality (YLL), years lived with disability (YLD), and disability-adjusted life years (DALY). At the same time, we used the population from 2010 national census as standard population to calculate the age-standardized mortality rate and DALY rate, YLL rate and YLD rates which will describe the mortality status and disease burden of total and different types of cardiovascular disease. We also calculated the change in 1990 and 2010 for all indexes, to describe the change of the burden of disease in the 20 years. In 2010, the total deaths of cardiovascular and circulatory diseases reached 3.136 2 million, the mortality rate reached 233.70 per 100 000 people and the age-standardized mortality rate was 256.90 per 100 000 people. The total DALYs, YLLs, and YLDs of cardiovascular and circulatory diseases reached 58.2055, 54.0488, and 4.1568 million person-years, respectively, and the age-standardized DALY rate, YLL rate and YLD rate were 4 639.04, 4 313.13, 325.91 per 100 000. In 1990, the deaths only 2.1675 million and the DALYs, YLLs and YLDs were 45.2679, 42.2922, and 2.9757 million person-years. The age-standardized mortality rate was 300.30 per 100 000 people. And the age-standardized DALY rate, YLL rate and YLD rate were 5 872.58, 5 523.42 and 349.16 per 100 000. Compared with the result in 1990, the total deaths, DALYs, YLLs, and YLDs were increased 44.72%, 28.58%, 27.80%, and 39.68%, respectively, while the age-standardized mortality rate, age-standardized DALY rate, age-standardized YLL rate, and age-standardized YLD rate were decreased 14.45%, 21.01%, 21.91%, and 6.66%, respectively. In 1990 and 2010, cerebrovascular disease caused the most DALYs (24.8768 and 30.1389 million person-years, respectively) compared with other types of cardiovascular and circulatory diseases, and followed by ischemic heart disease (10.1270 and 17.8858 million person-years). And the YLLs of cerebrovascular disease (24.3436 and 29.1726 million person-years) also the highest in different type of cardiovascular and circulatory diseases, ischemic heart disease (8.9919 and 16.0839 million person-years) was the second highest. The deaths of cerebrovascular disease and cerebrovascular disease increased from 1 340.6 and 450.3 thousands in 1990 to 1 726.7 and 948.7 thousands in 2010, respectively. The age-standardized mortality rate and DALY rate of cerebrovascular disease were decreased from 187.19 and 3 335.37 per 100 000 people in 1990 to 141.43 and 2 409.09 per 100 000 people. While in the ischemic heart disease, the age-standardized mortality rate, and DALY rate were increased form 62.53 and 1 318.38 per 100 000 people in 1990 to 77.89 and 1 428.31 per 100 000 people. Burden of cardiovascular and circulatory disease became more and more serious in China, of which the cerebrovascular disease and ischemic heart disease were most serious.

Baylor Gyro Pump: a completely seal-less centrifugal pump aiming for long-term circulatory support.

PubMed

Ohara, Y; Sakuma, I; Makinouchi, K; Damm, G; Glueck, J; Mizuguchi, K; Naito, K; Tasai, K; Orime, Y; Takatani, S

1993-07-01

A seal-less centrifugal pump aiming for long-term circulatory support has been developed. In this model, shaft seals that cause thrombus formation and blood leakage were eliminated. A brushless direct current motor was incorporated as a driving unit, and pivot bearings were used to support the impeller. With reference to its motor-driven system, this pump was named the M-Gyro Pump. The first model (M1) yielded an index of hemolysis of 0.005 g/100 L using bovine blood and demonstrated satisfactory performance as a right heart assist for 2 days (4 L/min, 60 mm Hg, 1,800 rpm). The second model (M2) has been developed for left heart assist by employing a stronger motor. The pump capacity was improved to 6 L/min against 240 mm Hg at 1,800 rpm, but significant heat generation was observed. By optimization of motor efficiency, the M2 model can be improved to meet the requirements of a pump for left heart assist.

Serious hazards of transfusion - conference report: celebration of 20 years of UK haemovigilance.

PubMed

Bolton-Maggs, P H B

2017-12-01

The Annual SHOT Report for incidents in 2016 was published on July 12 and celebrated of 20 years of UK haemovigilance. Components are very safe, related in part to risk-reduction measures triggered by SHOT reporting. Transfusion-related acute lung injury is now very rare (all plasma components are provided from male donors), and infection transmission is also uncommon - a single transmission of hepatitis E in 2016 and no bacterial transmissions. Human factors (errors) account for 87% of all reports. Deaths and major morbidity most often result from transfusion-associated circulatory overload. Wrong transfusions and deaths from ABO-incompatible transfusion can be reduced by correct bedside checks. It is notable that information technology systems may not be safe. Standardisation is required for flags and alerts. SHOT key recommendations include: assess patients for transfusion-associated circulatory overload prior to transfusion. Be like a pilot - use a bedside checklist when setting up the transfusion. © 2017 British Blood Transfusion Society.

CO2-O2 interactions in extension of tolerance to acute hypoxia

NASA Technical Reports Server (NTRS)

Lambertsen, C. J.

1995-01-01

Objectives and results of experimental projects a re summarized. The scope of information desired included (1) physiological and performance consequences of exposures to simulated microgravity, in rest and graded physical activity, (2) separate influences of graded degrees of atmospheric hypercapnia and hypoxia, and (3) composite effects of hypoxia and hypercapnia. The research objectives were selected for close relevance to existing quantitative information concerning interactions of hypercapnia and hypoxia on respiratory and brain circulatory control. They include: (1) to determine influences of normoxic immersion on interrelations of pulmonary ventilation, arterial PCO2 and PO2, and brain blood flow, in rest and physical work; (2) to determine influence of normoxic immersion on respiratory reactivity to atmospheric hypercapnia at rest; (3) to determine influence of atmospheric hypoxia on respiratory reactivity to hypercapnia at rest and in work; and (4) to provide physiological baselines of data concerning adaptations in acute exposures to aid in investigation of rates of adaptation or deteriorations in physiological or performance capability during subsequent multi-day exposures. A list of publications related to the present grant period is included along with an appendix describing the Performance Measurement System (human perceptual, cognitive and psychomotor functions).

A laboratory exercise using a physical model for demonstrating countercurrent heat exchange.

PubMed

Loudon, Catherine; Davis-Berg, Elizabeth C; Botz, Jason T

2012-03-01

A physical model was used in a laboratory exercise to teach students about countercurrent exchange mechanisms. Countercurrent exchange is the transport of heat or chemicals between fluids moving in opposite directions separated by a permeable barrier (such as blood within adjacent blood vessels flowing in opposite directions). Greater exchange of heat or chemicals between the fluids occurs when the flows are in opposite directions (countercurrent) than in the same direction (concurrent). When a vessel loops back on itself, countercurrent exchange can occur between the two arms of the loop, minimizing loss or uptake at the bend of the loop. Comprehension of the physical principles underlying countercurrent exchange helps students to understand how kidneys work and how modifications of a circulatory system can influence the movement of heat or chemicals to promote or minimize exchange and reinforces the concept that heat and chemicals move down their temperature or concentration gradients, respectively. One example of a well-documented countercurrent exchanger is the close arrangement of veins and arteries inside bird legs; therefore, the setup was arranged to mimic blood vessels inside a bird leg, using water flowing inside tubing as a physical proxy for blood flow within blood vessels.

Mechanical design in arteries.

PubMed

Shadwick, R E

1999-12-01

The most important mechanical property of the artery wall is its non-linear elasticity. Over the last century, this has been well-documented in vessels in many animals, from humans to lobsters. Arteries must be distensible to provide capacitance and pulse-smoothing in the circulation, but they must also be stable to inflation over a range of pressure. These mechanical requirements are met by strain-dependent increases in the elastic modulus of the vascular wall, manifest by a J-shaped stress-strain curve, as typically exhibited by other soft biological tissues. All vertebrates and invertebrates with closed circulatory systems have arteries with this non-linear behaviour, but specific tissue properties vary to give correct function for the physiological pressure range of each species. In all cases, the non-linear elasticity is a product of the parallel arrangement of rubbery and stiff connective tissue elements in the artery wall, and differences in composition and tissue architecture can account for the observed variations in mechanical properties. This phenomenon is most pronounced in large whales, in which very high compliance in the aortic arch and exceptionally low compliance in the descending aorta occur, and is correlated with specific modifications in the arterial structure.

Semaphorin 3G Provides a Repulsive Guidance Cue to Lymphatic Endothelial Cells via Neuropilin-2/PlexinD1.

PubMed

Liu, Xinyi; Uemura, Akiyoshi; Fukushima, Yoko; Yoshida, Yutaka; Hirashima, Masanori

2016-11-22

The vertebrate circulatory system is composed of closely related blood and lymphatic vessels. It has been shown that lymphatic vascular patterning is regulated by blood vessels during development, but its molecular mechanisms have not been fully elucidated. Here, we show that the artery-derived ligand semaphorin 3G (Sema3G) and the endothelial cell receptor PlexinD1 play a role in lymphatic vascular patterning. In mouse embryonic back skin, genetic inactivation of Sema3G or PlexinD1 results in abnormal artery-lymph alignment and reduced lymphatic vascular branching. Conditional ablation in mice demonstrates that PlexinD1 is primarily required in lymphatic endothelial cells (LECs). In vitro analyses show that Sema3G binds to neuropilin-2 (Nrp2), which forms a receptor complex with PlexinD1. Sema3G induces cell collapse in an Nrp2/PlexinD1-dependent manner. Our findings shed light on a molecular mechanism by which LECs are distributed away from arteries and form a branching network during lymphatic vascular development. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

[Death causes in 428 alcoholic patients: a descriptive study].

PubMed

Martínez Lanz, P; Días Coto, C

1992-12-01

Several studies have demonstrated either a direct or an indirect relationship between alcoholism and death causes. The present paper is a descriptive study about death causes in 428 alcoholic patients from San José, Costa Rica, metropolitan area, whose death occurred between 1978 and 1988. Sample subjects were males, under 90-year-old at death time. It was found out that basic death causes were: Traumatism and poisoning, 25%; circulatory system illnesses, 20%; digestive system illnesses, 18.5%, and tumors, 15%.

A 12 year prospective study of circulatory disease among Danish shift workers.

PubMed

Tüchsen, F; Hannerz, H; Burr, H

2006-07-01

Previous studies of the risk of heart disease after shift work reached different estimates and review authors disagree about the validity of some of the studies. A cross sectional study showed that shift workers had a higher prevalence of nearly every unfavourable work environment factor investigated. Conflicts at work and low decision latitude were more frequent among shift workers, and all-day walking or standing work and part-time jobs were more often found among female shift workers. To estimate the risk of circulatory disease in a prospective follow up of a representative sample of gainfully employed Danes, considering known or suspected confounding factors. A cohort of 5517 people who were gainfully employed in 1990 were followed up for all hospital treatments due to circulatory diseases (390-458, ICD-8; I00-I99, ICD-10) from 1991 to 2002 inclusive. A log linear Poisson regression model was applied to control confounding factors and calculate the relative risk for 927 men and women working nights, evenings, or other non-day shifts compared to 4579 day workers. Non-day workers compared to day workers had a relative risk (RR) for all circulatory diseases of 1.31 (95% CI 1.06-1.63). Without control for BMI and smoking, the RR estimate was 1.33 (95% CI 1.07-1.65). For a subgroup of workers with at least three years' seniority, the RR was 1.40 (95% CI 1.09-1.81). The population based aetiological fraction of shift work was estimated to 5%. This study adds to a growing body of evidence suggesting that shift work carries an excess risk of circulatory diseases.

Practical Considerations in Donation After Circulatory Determination of Death in Switzerland.

PubMed

Dalle Ave, Anne L; Shaw, David M; Elger, Bernice

2017-09-01

Faced with similar issues of organ scarcity to its neighbors, Switzerland has developed donation after circulatory determination of death (DCDD) as a way to expand the organ pool since 1985. Here, we analyze the history, practical considerations, and ethical issues relating to the Swiss donation after circulatory death programs. In Switzerland, determination of death for DCDD requires a stand-off period of 10 minutes. This time between cardiac arrest and the declaration of death is mandated in the guidelines of the Swiss Academy of Medical Sciences. As in other DCDD programs, safeguards are put to avoid physicians denying lifesaving treatment to savable patients because of being influenced by receivers' interest. An additional recommendation could be made: Recipients should be transparently informed of the worse graft outcomes with DCDD programs and given the possibility to refuse such organs.

EXTRACORPOREAL MEMBRANE OXYGENATION vs. COUNTERPULSATILE, PULSATILE, AND CONTINUOUS LEFT VENTRICULAR UNLOADING FOR PEDIATRIC MECHANICAL CIRCULATORY SUPPORT

PubMed Central

Bartoli, Carlo R.; Koenig, Steven C.; Ionan, Constantine; Gillars, Kevin J.; Mitchell, Mike E.; Austin, Erle H.; Gray, Laman A.; Pantalos, George M.

2014-01-01

OBJECTIVE Despite progress with adult ventricular assist devices (VADs), limited options exist to support pediatric patients with life-threatening heart disease. Extracorporeal membrane oxygenation (ECMO) remains the clinical standard. To characterize (patho)physiologic responses to different modes of mechanical unloading of the failing pediatric heart, ECMO was compared to either intraaortic balloon pump (IABP), pulsatile-flow (PF)VAD, or continuous-flow (CF)VAD support in a pediatric heart failure model. DESIGN Experimental. SETTING Large animal laboratory operating room. SUBJECTS Yorkshire piglets (n=47, 11.7±2.6 kg). INTERVENTIONS In piglets with coronary ligation-induced cardiac dysfunction, mechanical circulatory support devices were implanted and studied during maximum support. MEASUREMENTS and MAIN RESULTS Left ventricular, right ventricular, coronary, carotid, systemic arterial, and pulmonary arterial hemodynamics were measured with pressure and flow transducers. Myocardial oxygen consumption and total-body oxygen consumption (VO2) were calculated from arterial, venous, and coronary sinus blood sampling. Blood flow was measured in 17 organs with microspheres. Paired student t-tests compared baseline and heart failure conditions. One-way repeated-measures ANOVA compared heart failure, device support mode(s), and ECMO. Statistically significant (p<0.05) findings included: 1) improved left ventricular blood supply/demand ratio during PFVAD, CFVAD, and ECMO but not IABP support, 2) improved global myocardial blood supply/demand ratio during PFVAD, and CFVAD but not IABP or ECMO support, and 3) diminished pulsatility during ECMO and CFVAD but not IABP and PFVAD support. A profile of systems-based responses was established for each type of support. CONCLUSIONS Each type of pediatric VAD provided hemodynamic support by unloading the heart with a different mechanism that created a unique profile of physiological changes. These data contribute novel, clinically relevant insight into pediatric mechanical circulatory support and establish an important resource for pediatric device development and patient selection. PMID:24108116

Identification of Ginkgo biloba supplements adulteration using high performance thin layer chromatography and ultra high performance liquid chromatography-diode array detector-quadrupole time of flight-mass spectometry

USDA-ARS?s Scientific Manuscript database

Ginkgo biloba is one of the most widely sold herbal supplements and medicines in the world. Its popularity stems to have a positive effect on memory and the circulatory system in clinical studies. As ginkgo popularity increased, non-proprietary extracts were introduced claiming to have similar phyto...

The Effectiveness of Using Student and Teacher Centered Analogies on the Development of the Students' Cognitive and Affective Skills

ERIC Educational Resources Information Center

Kilic, Oznur; Topsakal, Unsal Umdu

2011-01-01

The aim of this study was to investigate the effects of teacher-centered and student-centered analogies on student academic achievement, conceptual understanding and attitude, concerning the topic of the circulatory system in a science and technology lesson. A quasi-experimental design was used. The sample consists of 49 sixth grade students in…

Medical Surveillance Monthly Report (MSMR). Volume 8, Number 2, March/April 2002

DTIC Science & Technology

2002-04-01

anomalies, including malocclusion 526 11 Intestinal infections due to other organisms 106 11 Diseases of esophagus 504 10 Infectious mononucleosis 79 8...gastroenteritis, colitis 79 7 Infectious mononucleosis 13 5 Diseases of esophagus 67 6 Neoplasms (140 - 239) 752 Genitourinary system (580 - 629) 1,529... infectious , and respiratory conditions; however, they generally increased with age for digestive, musculoskeletal, genitourinary, circulatory

Delivering Educational Multimedia Contents through an Augmented Reality Application: A Case Study on Its Impact on Knowledge Acquisition and Retention

ERIC Educational Resources Information Center

Perez-Lopez, David; Contero, Manuel

2013-01-01

This paper presents a study to analyze the use of augmented reality (AR) for delivering multimedia content to support the teaching and learning process of the digestive and circulatory systems at the primary school level, and its impact on knowledge retention. Our AR application combines oral explanations and 3D models and animations of anatomical…

Medical Terminology of the Circulatory System. Medical Records. Instructional Unit for the Medical Transcriber.

ERIC Educational Resources Information Center

Gosman, Minna L.

Developed as a result of an analysis of the task of transcribing as practiced in a health facility, this study guide was designed to teach the knowledge and skills required of a medical transcriber. The medical record department was identified as a major occupational area, and a task inventory for medical records was developed and used as a basis…

Snake constriction rapidly induces circulatory arrest in rats.

PubMed

Boback, Scott M; McCann, Katelyn J; Wood, Kevin A; McNeal, Patrick M; Blankenship, Emmett L; Zwemer, Charles F

2015-07-01

As legless predators, snakes are unique in their ability to immobilize and kill their prey through the process of constriction, and yet how this pressure incapacitates and ultimately kills the prey remains unknown. In this study, we examined the cardiovascular function of anesthetized rats before, during and after being constricted by boas (Boa constrictor) to examine the effect of constriction on the prey's circulatory function. The results demonstrate that within 6 s of being constricted, peripheral arterial blood pressure (PBP) at the femoral artery dropped to 1/2 of baseline values while central venous pressure (CVP) increased 6-fold from baseline during the same time. Electrocardiographic recordings from the anesthetized rat's heart revealed profound bradycardia as heart rate (fH) dropped to nearly half of baseline within 60 s of being constricted, and QRS duration nearly doubled over the same time period. By the end of constriction (mean 6.5±1 min), rat PBP dropped 2.9-fold, fH dropped 3.9-fold, systemic perfusion pressure (SPP=PBP-CVP) dropped 5.7-fold, and 91% of rats (10 of 11) had evidence of cardiac electrical dysfunction. Blood drawn immediately after constriction revealed that, relative to baseline, rats were hyperkalemic (serum potassium levels nearly doubled) and acidotic (blood pH dropped from 7.4 to 7.0). These results are the first to document the physiological response of prey to constriction and support the hypothesis that snake constriction induces rapid prey death due to circulatory arrest. © 2015. Published by The Company of Biologists Ltd.

Effect of tilting on blood pressure and interstitial fluid pressures of bluefish and smooth dogfish.

PubMed

Ogilvy, C S; DuBois, A B

1982-01-01

Tolerance of the circulatory system of fish for gravitational stress has not been measured previously. We examined this in bluefish (Pomatomus saltatrix) and smooth dogfish (Mustelus canis) by placing them horizontally on a V-board in air while their gills were perfused with aerated seawater, then tilting them head up for 0.5 h, and finally returning them to horizontal. Meanwhile, we recorded the blood pressure, pulse pressure, and heart rate in the ventral aorta, and interstitial fluid pressure in the head and tail. All four bluefish tolerated a 30 degrees tilt or even a 60 degrees tilt with little change in blood pressure or interstitial pressure in the anterior and posterior regions. All recovered afterward. However, in the seven dogfish examined, the posterior interstitial fluid pressure increased from 2.8 +/- 1.0 cmH2O before tilting to 11.8 +/- 3.3 cmH2O toward the end of a 30 degrees tilt lasting 30 min. The blood pressure decreased as the pulse pressure approached zero, showing that circulatory insufficiency had developed due to insufficient venous return to the heart. Most of the dogfish died within a few hours after the experiment. These findings are in keeping with the conclusion that the vasculature of bluefish has more rigidity, less permeability, and perhaps more compensatory tone than that of smooth dogfish. We speculate that bluefish may have evolved their circulatory tolerance for gravity as a cross-adaptation to the stresses imposed on the circulation by forward acceleration and by regional differences of transcutaneous pressure occurring during fast carangiform swimming.

Effects of Particulate Matter and Its Chemical Constituents on Elderly Hospital Admissions Due to Circulatory and Respiratory Diseases

PubMed Central

Ferreira, Tatiane Morais; Forti, Maria Cristina; de Freitas, Clarice Umbelino; Nascimento, Felipe Parra; Junger, Washington Leite; Gouveia, Nelson

2016-01-01

Various fractions of particulate matter have been associated with increased mortality and morbidity. The purpose of our study is to analyze the associations between concentrations of PM2.5, PM2.5–10, PM10 and their chemical constituents (soluble ions) with hospital admissions due to circulatory and respiratory diseases among the elderly in a medium-sized city in Brazil. A time series study was conducted using Poisson regression with generalized additive models adjusted for confounders. Statistically significant associations were identified between PM10 and PM2.5–10 and respiratory diseases. Risks of hospitalization increased by 23.5% (95% CI: 13.5; 34.3) and 12.8% (95% CI: 6.0; 20.0) per 10 μg/m3 of PM2.5-10 and PM10, respectively. PM2.5 exhibited a significant association with circulatory system diseases, with the risk of hospitalization increasing by 19.6% (95% CI: 6.4; 34.6) per 10 μg/m3. Regarding the chemical species; SO42−, NO3−, NH4+ and K+ exhibited specific patterns of risk, relative to the investigated outcomes. Overall, SO42− in PM2.5–10 and K+ in PM2.5 were associated with increased risk of hospital admissions due to both types of diseases. The results agree with evidence indicating that the risks for different health outcomes vary in relation to the fractions and chemical composition of PM10. Thus, PM10 speciation studies may contribute to the establishment of more selective pollution control policies. PMID:27669280

Experts' recommendations for the management of cardiogenic shock in children.

PubMed

Brissaud, Olivier; Botte, Astrid; Cambonie, Gilles; Dauger, Stéphane; de Saint Blanquat, Laure; Durand, Philippe; Gournay, Véronique; Guillet, Elodie; Laux, Daniela; Leclerc, Francis; Mauriat, Philippe; Boulain, Thierry; Kuteifan, Khaldoun

2016-12-01

Cardiogenic shock which corresponds to an acute state of circulatory failure due to impairment of myocardial contractility is a very rare disease in children, even more than in adults. To date, no international recommendations regarding its management in critically ill children are available. An experts' recommendations in adult population have recently been made (Levy et al. Ann Intensive Care 5(1):52, 2015; Levy et al. Ann Intensive Care 5(1):26, 2015). We present herein recommendations for the management of cardiogenic shock in children, developed with the grading of recommendations' assessment, development, and evaluation system by an expert group of the Groupe Francophone de Réanimation et Urgences Pédiatriques (French Group for Pediatric Intensive Care and Emergencies). The recommendations cover four major fields of application such as: recognition of early signs of shock and the patient pathway, management principles and therapeutic goals, monitoring hemodynamic and biological variables, and circulatory support (indications, techniques, organization, and transfer criteria). Major principle care for children with cardiogenic shock is primarily based on clinical and echocardiographic assessment. There are few drugs reported as effective in childhood in the medical literature. The use of circulatory support should be facilitated in terms of organization and reflected in the centers that support these children. Children with cardiogenic shock are vulnerable and should be followed regularly by intensivist cardiologists and pediatricians. The experts emphasize the multidisciplinary nature of management of children with cardiogenic shock and the importance of effective communication between emergency medical assistance teams (SAMU), mobile pediatric emergency units (SMUR), pediatric emergency departments, pediatric cardiology and cardiac surgery departments, and pediatric intensive care units.

Study report on modification of the long term circulatory model for the simulation of bed rest

NASA Technical Reports Server (NTRS)

Leonard, J. I.; Grounds, D. J.

1977-01-01

Modifications were made of the circulatory, fluid, and electrolyte control model which was based on the model of Guyton. The modifications included separate leg compartments and the addition of gravity dependency. It was found that these modifications allowed for more accurate bed rest simulation by simulating changes in the orthostatic gradient and simulating the response to the fluid shifts associated with bed rest.

Determination of death after circulatory arrest by intensive care physicians: A survey of current practice in the Netherlands.

PubMed

Wind, Jentina; van Mook, Walther N K A; Dhanani, Sonny; van Heurn, Ernest W L

2016-02-01

Determination of death is an essential part of donation after circulatory death (DCD). We studied the current practices of determination of death after circulatory arrest by intensive care physicians in the Netherlands, the availability of guidelines, and the occurrence of the phenomenon of autoresuscitation. The Determination of Cardiac Death Practices in Intensive Care Survey was sent to all intensive care physicians. Fifty-five percent of 568 Dutch intensive care physicians responded. Most respondents learned death determination from clinical practice. The most commonly used tests for death determination were flat arterial line tracing, flat electrocardiogram (standard 3-lead electrocardiogram), and fixed and dilated pupils. Rarely used tests were absence pulse by echo Doppler, absent blood pressure by noninvasive monitoring, and unresponsiveness to painful stimulus. No diagnostic test or procedure was uniformly performed, but 80% of respondents perceived a need for standardization of death determination. Autoresuscitation was witnessed by 37%, after withdrawal of treatment or after unsuccessful resuscitation. Extensive variability in the practice of determining death after circulatory arrest exists, and a need for guidelines and standardization, especially if organ donation follows death, is reported. Autoresuscitation is reported; this observation requires attention in further prospective observational studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Quantification of fetal and total circulatory DNA in maternal plasma samples before and after size fractionation by agarose gel electrophoresis.

PubMed

Hromadnikova, I; Zejskova, L; Doucha, J; Codl, D

2006-11-01

Fetal extracellular DNA is mainly derived from apoptotic bodies of trophoblast. Recent studies have shown size differences between fetal and maternal extracellular DNA. We have examined the quantification of fetal (SRY gene) and total (GLO gene) extracellular DNA in maternal plasma in different fractions (100-300, 300-500, 500-700, 700-900, and >900 bp) after size fractionation by agarose gel electrophoresis. DNA was extracted from maternal plasma samples from 11 pregnant women carrying male foetuses at the 16th week of gestation. Fetal circulatory DNA was mainly detected in the 100-300 bp fraction with the median concentration being 14.4 GE/ml. A lower median amount of 4.9 GE/ml was also found in the 300-500 bp fraction. Circulatory DNA extracted from the 100-300 bp fraction contained 4.2 times enriched fetal DNA when compared with unseparated DNA sample. Fetal DNA within the 300-500 bp fraction was 2.5 times enriched. Circulatory fetal DNA is predominantly present in a fraction with molecular size <500 bp, which can be used for the detection of paternally inherited alleles. However, the usage of size-separated DNA is not suitable for routine clinical applications because of risk of contamination.

Does Bohm's Quantum Force Have a Classical Origin?

NASA Astrophysics Data System (ADS)

Lush, David C.

2016-08-01

In the de Broglie-Bohm formulation of quantum mechanics, the electron is stationary in the ground state of hydrogenic atoms, because the quantum force exactly cancels the Coulomb attraction of the electron to the nucleus. In this paper it is shown that classical electrodynamics similarly predicts the Coulomb force can be effectively canceled by part of the magnetic force that occurs between two similar particles each consisting of a point charge moving with circulatory motion at the speed of light. Supposition of such motion is the basis of the Zitterbewegung interpretation of quantum mechanics. The magnetic force between two luminally-circulating charges for separation large compared to their circulatory motions contains a radial inverse square law part with magnitude equal to the Coulomb force, sinusoidally modulated by the phase difference between the circulatory motions. When the particles have equal mass and their circulatory motions are aligned but out of phase, part of the magnetic force is equal but opposite the Coulomb force. This raises a possibility that the quantum force of Bohmian mechanics may be attributable to the magnetic force of classical electrodynamics. It is further shown that relative motion between the particles leads to modulation of the magnetic force with spatial period equal to the de Broglie wavelength.

Angiotensin peptides in the non-gravid uterus: Paracrine actions beyond circulation.

PubMed

Casalechi, Maíra; Dela Cruz, Cynthia; Lima, Luiza C; Maciel, Luciana P; Pereira, Virgínia M; Reis, Fernando M

2018-03-01

The renin-angiotensin system (RAS) involves a complex network of precursors, peptides, enzymes and receptors comprising a systemic (endocrine) and a local (paracrine/autocrine) system. The local RAS plays important roles in tissue modulation and may operate independently of or in close interaction with the circulatory RAS, acting in a complementary fashion. Angiotensin (Ang) II, its receptor AT 1 and Ang-(1-7) expression in the endometrium vary with menstrual cycle, and stromal cell decidualization in vitro is accompanied by local synthesis of angiotensinogen and prorenin. Mas receptor is unlikely to undergo marked changes accompanying the cyclic ovarian steroid hormone fluctuations. Studies investigating the functional relevance of the RAS in the non-gravid uterus show a number of paracrine effects beyond circulation and suggest that RAS peptides may be involved in the pathophysiology of proliferative and fibrotic diseases. Endometrial cancer is associated with increased expression of Ang II, Ang-converting enzyme 1 and AT 1 in the tumoral tissue compared to neighboring non-neoplastic endometrium, and also with a gene polymorphism that enhances AT 1 signal. Ang II induces human endometrial cells to transdifferentiate into cells with myofibroblast phenotype and to synthetize extracellular matrix components that might contribute to endometrial fibrosis. Altogether, these findings point to a fully operating RAS within the uterus, but since many concepts rely on preliminary evidence further studies are needed to clarify the role of the local RAS in uterine physiology and pathophysiology. Copyright © 2018 Elsevier Inc. All rights reserved.

Cell and molecular biology of marine elasmobranchs: Squalus acanthias and Raja erinacea.

PubMed

Mattingly, Carolyn; Parton, Angela; Dowell, Lori; Rafferty, Jason; Barnes, David

2004-01-01

Elasmobranchs are among the most primitive existing species exhibiting fundamental vertebrate characteristics, such as neural crest, jaws, teeth, and an adaptive immune system. They are also among the earliest-evolved vertebrates with a closed, pressurized circulatory system and related signaling molecules. Although many species are used experimentally, the spiny dogfish shark (Squalus acanthias) and little skate (Raja erinacea) have particular advantages and are the most commonly used elasmobranch biomedical models. These animals display powerful molecular systems for dealing with salt and water homeostasis, cell volume regulation, and environmental and internal osmotic sensing. They have become important unique models in studies of transport-related diseases such as cystic fibrosis and anion or xenobiotic transport. Much of this work has relied on physiological experiments combined with molecular approaches and the advantages of comparative genomic analyses to identify conserved regions representing functional protein domains. Recent work has seen the development of cell cultures and the beginning of expressed sequence tags (EST) and genomic libraries. Other areas in which elasmobranches have played critical roles include immunology and neurobiology. It also appears that sharks have tissue regenerative capability beyond what is commonly seen in mammals. For example, sharks and skates possess a region of renal regeneration, with new tubules being formed continually through adulthood. As comparative functional genomics comes of age, these comparative vertebrate models may play an increasing role in the larger picture of human biomedical research. There is plenty of ocean to share.

Gastrointestinal disorders associated with migraine: A comprehensive review

PubMed Central

Cámara-Lemarroy, Carlos R; Rodriguez-Gutierrez, Rene; Monreal-Robles, Roberto; Marfil-Rivera, Alejandro

2016-01-01

Migraine is a recurrent and commonly disabling primary headache disorder that affects over 17% of women and 5%-8% of men. Migraine susceptibility is multifactorial with genetic, hormonal and environmental factors all playing an important role. The physiopathology of migraine is complex and still not fully understood. Many different neuropeptides, neurotransmitters and brain pathways have been implicated. In connection with the myriad mechanisms and pathways implicated in migraine, a variety of multisystemic comorbidities (e.g., cardiovascular, psychiatric and other neurological conditions) have been found to be closely associated with migraine. Recent reports demonstrate an increased frequency of gastrointestinal (GI) disorders in patients with migraine compared with the general population. Helicobacter pylori infection, irritable bowel syndrome, gastroparesis, hepatobiliary disorders, celiac disease and alterations in the microbiota have been linked to the occurrence of migraine. Several mechanisms involving the gut-brain axis, such as a chronic inflammatory response with inflammatory and vasoactive mediators passing to the circulatory system, intestinal microbiota modulation of the enteric immunological milieu and dysfunction of the autonomic and enteric nervous system, have been postulated to explain these associations. However, the precise mechanisms and pathways related to the gut-brain axis in migraine need to be fully elucidated. In this review, we survey the available literature linking migraine with GI disorders. We discuss the possible physiopathological mechanisms, and clinical implications as well as several future areas of interest for research. PMID:27688656

Gastrointestinal disorders associated with migraine: A comprehensive review.

PubMed

Cámara-Lemarroy, Carlos R; Rodriguez-Gutierrez, Rene; Monreal-Robles, Roberto; Marfil-Rivera, Alejandro

2016-09-28

Migraine is a recurrent and commonly disabling primary headache disorder that affects over 17% of women and 5%-8% of men. Migraine susceptibility is multifactorial with genetic, hormonal and environmental factors all playing an important role. The physiopathology of migraine is complex and still not fully understood. Many different neuropeptides, neurotransmitters and brain pathways have been implicated. In connection with the myriad mechanisms and pathways implicated in migraine, a variety of multisystemic comorbidities (e.g., cardiovascular, psychiatric and other neurological conditions) have been found to be closely associated with migraine. Recent reports demonstrate an increased frequency of gastrointestinal (GI) disorders in patients with migraine compared with the general population. Helicobacter pylori infection, irritable bowel syndrome, gastroparesis, hepatobiliary disorders, celiac disease and alterations in the microbiota have been linked to the occurrence of migraine. Several mechanisms involving the gut-brain axis, such as a chronic inflammatory response with inflammatory and vasoactive mediators passing to the circulatory system, intestinal microbiota modulation of the enteric immunological milieu and dysfunction of the autonomic and enteric nervous system, have been postulated to explain these associations. However, the precise mechanisms and pathways related to the gut-brain axis in migraine need to be fully elucidated. In this review, we survey the available literature linking migraine with GI disorders. We discuss the possible physiopathological mechanisms, and clinical implications as well as several future areas of interest for research.

Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System.

PubMed

Bozkurt, Selim; van de Vosse, Frans N; Rutten, Marcel C M

Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.

Servo-controlled hind-limb electrical stimulation for short-term arterial pressure control.

PubMed

Kawada, Toru; Shimizu, Shuji; Yamamoto, Hiromi; Shishido, Toshiaki; Kamiya, Atsunori; Miyamoto, Tadayoshi; Sunagawa, Kenji; Sugimachi, Masaru

2009-05-01

Autonomic neural intervention is a promising tool for modulating the circulatory system thereby treating some cardiovascular diseases. In 8 pentobarbital-anesthetized cats, it was examined whether the arterial pressure (AP) could be controlled by acupuncture-like hind-limb electrical stimulation (HES). With a 0.5-ms pulse width, HES monotonically reduced AP as the stimulus current increased from 1 to 5 mA, suggesting that the stimulus current could be a primary control variable. In contrast, the depressor effect of HES showed a nadir approximately 10 Hz in the frequency range between 1 and 100 Hz. Dynamic characteristics of the AP response to HES approximated a second-order low-pass filter with dead time (gain: -10.2 +/- 1.6 mmHg/mA, natural frequency: 0.040 +/- 0.004 Hz, damping ratio 1.80 +/- 0.24, dead time: 1.38 +/- 0.13 s, mean +/- SE). Based on these dynamic characteristics, a servo-controlled HES system was developed. When a target AP value was set at 20 mmHg below the baseline AP, the time required for the AP response to reach 90% of the target level was 38 +/- 10 s. The steady-state error between the measured and target AP values was 1.3 +/- 0.1 mmHg. Autonomic neural intervention by acupuncture-like HES might provide an additional modality to quantitatively control the circulatory system.

Disability trends in the United States population 1966-76: analysis of reported causes.

PubMed Central

Colvez, A; Blanchet, M

1981-01-01

According to data published by the United States National Center for Health Statistics, disability reported among the US population has increased substantially during the years 1966 to 1976. Among younger age groups, the increase in activity limitation involves visual and hearing impairments as well as asthma. In the middle age group (45-64), four causes increased in both sexes (diabetes, musculoskeletal disorders, hypertension, and diseases of the circulatory system other than hypertension and heart conditions); one cause affected men only (heart conditions) and one women only (malignant neoplasms). In the 65 and over age group, diabetes and circulatory diseases (excluding heart conditions and hypertension) increased significantly. Although the US population increased by 10 per cent, the number of persons permanently limited in their activities because of health conditions increased by 37 per cent with a much larger proportion of those disabled claiming to be unable to carry on their main activity. Changes in health survey procedures and changes in standards used by respondents to rate their health status are not believed to account for these findings. Factors which could have contributed to this trend include environmental deterioration and improved social benefits easing retirement and providing better access to the health care system. Planning agencies need to recognize the relationships of the health care system to disability as well as to mortality. PMID:6452067

Multiple pregnancies achieved with IVF/ICSI and risk of specific congenital malformations: a meta-analysis of cohort studies.

PubMed

Zheng, Zan; Chen, Letao; Yang, Tubao; Yu, Hong; Wang, Hua; Qin, Jiabi

2018-04-01

Studies comparing risk of specific congenital malformations (CM) between multiple pregnancies resulting from IVF/intracytoplasmic sperm injection (ICSI) and those conceived naturally report conflicting results; furthermore, there is a lack of a complete overview. This meta-analysis aimed to address which types of CM are increased in IVF/ICSI multiple pregnancies compared with those conceived naturally. All studies testing the association between IVF/ICSI multiple pregnancies and specific CM identified in various databases were considered. The literature search yielded 856 records, of which 21 cohort studies were included for analysis. Overall, multiple pregnancies achieved with IVF/ICSI experienced a significantly higher risk of chromosomal defects (relative risk [RR] = 1.36; 95% confidence interval [CI]: 1.04-1.77), urogenital (RR = 1.18; 95% CI: 1.03-1.36) and circulatory (RR = 1.22; 95% CI: 1.01-1.47) system malformations. However, the remaining specific CM, such as cleft lip and/or palate, eye, ear, face and neck, respiratory, musculoskeletal, nervous and digestive system malformations, were similar in the two groups. No substantial heterogeneity was observed for most outcomes except for digestive (P = 0.094; I 2 = 38.3%) and circulatory (P = 0.070; I 2 = 35.2%) system malformations. These findings provide additional information on risks of IVF/ICSI for use when counselling patients. Copyright © 2018 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

[Progress in the protective medicine against [correction of aganist] rocket propellents].

PubMed

Hu, W X; Tan, C Y; Tan, S J; Jiang, J

1999-12-01

To review the progress in the major assignment, the organization and implementation of protection against liquid rocket propellent. The safety detection methods of the rocket [correction of rocked] propellent in the launching field were also discussed. Three steps of the sanitation and protection of the liquid propellent, the toxicity and the toxicology of hydrazine on central nervous system, blood circulatory system, assimilation system, respiratory system, immune system, liver, kidney, eye, skin and its hereditary toxicology were described. In addition, the clinical types of poisoning, the current principle and the common ways of the prevention and treatment of hydrazine and nitrogen oxides poisoning were summarized.

Mortality from systemic erythematosus lupus in Brazil: evaluation of causes according to the government health database.

PubMed

Costi, Luisa Ribeiro; Iwamoto, Hatsumi Miyashiro; Neves, Dilma Costa de Oliveira; Caldas, Cezar Augusto Muniz

To characterize the causes of mortality in patients with systemic lupus erythematosus (SLE) in Brazil between 2002 and 2011. An exploratory ecological study of a time series using data from the Mortality Information System of DATASUS, the Department of the Unified Health System (Brazil's National Health System). Brazil's SLE mortality rate was 4.76 deaths/10 5 inhabitants. The mortality rate was higher in the Midwest, North and Southeast regions than in the country as a whole. There were 6.3% fewer and 4.2% more deaths than expected in the Northeast and Southeast regions, respectively. The mean age at death was 40.7±18 years, and 45.61% of deaths occurred between the ages of 20 and 39. Incidence was highest in women (90.7%) and whites (49.2%). Disorders of the musculoskeletal system and connective tissue were mentioned as an underlying cause of death in 77.5% of cases, and diseases of the circulatory system and infectious and parasitic diseases were also noted in fewer cases. SLE was mentioned as an underlying cause of death in 77% of cases, with no difference between the Brazilian regions (p=0.2058). The main SLE-related causes of death were, sequentially, diseases of the respiratory and circulatory systems and infectious and parasitic diseases. This study identified a need for greater control of risk factors for cardiovascular diseases and a better understanding of the pathogenesis of atherosclerosis in SLE. Infectious causes are still frequent, and management should be improved, especially in the early stages of the disease. Copyright © 2017 Elsevier Editora Ltda. All rights reserved.

Voluntary organ donation system adapted to Chinese cultural values and social reality.

PubMed

Huang, Jiefu; Millis, J Michael; Mao, Yilei; Millis, M Andrew; Sang, Xinting; Zhong, Shouxian

2015-04-01

Organ donation and transplant systems have unique characteristics based on the local culture and socioeconomic context. China's transplant and organ donation systems developed without regulatory oversight until 2006 when regulation and policy were developed and then implemented over the next several years. Most recently, the pilot project of establishing a voluntary citizen-based deceased donor program was established. The pilot program addressed the legal, financial, and cultural barriers to organ donation in China. The pilot program has evolved into a national program. Significantly, it established a uniquely Chinese donor classification system. The Chinese donor classification system recognizes donation after brain death (category I), donation after circulatory death (category II), and donation after brain death followed by circulatory death (category III). Through August 2014, the system has identified 2326 donors and provided 6416 organs that have been allocated though a transparent organ allocation system. The estimated number of donors in 2014 is 1147. As China's attitudes toward organ donation have matured and evolved and as China, as a nation, is taking its place on the world stage, it is recognizing that its past practice of using organs from executed prisoners is not sustainable. It is time to recognize that the efforts to regulate transplantation and provide voluntary citizen-based deceased organ donation have been successful and that China should use this system to provide organs for all transplants in every province and hospital in China. At the national organ transplant congress on October 30, 2014, the Chairman of the China's national organ donation and transplantation committee, Jeifu Huang required all hospitals to stop using organs from executed prisoners immediately and the civilian organ donation will be sole source for organ transplant in China starting January 2015. © 2015 American Association for the Study of Liver Diseases.

Lymphatic System in Cardiovascular Medicine.

PubMed

Aspelund, Aleksanteri; Robciuc, Marius R; Karaman, Sinem; Makinen, Taija; Alitalo, Kari

2016-02-05

The mammalian circulatory system comprises both the cardiovascular system and the lymphatic system. In contrast to the blood vascular circulation, the lymphatic system forms a unidirectional transit pathway from the extracellular space to the venous system. It actively regulates tissue fluid homeostasis, absorption of gastrointestinal lipids, and trafficking of antigen-presenting cells and lymphocytes to lymphoid organs and on to the systemic circulation. The cardinal manifestation of lymphatic malfunction is lymphedema. Recent research has implicated the lymphatic system in the pathogenesis of cardiovascular diseases including obesity and metabolic disease, dyslipidemia, inflammation, atherosclerosis, hypertension, and myocardial infarction. Here, we review the most recent advances in the field of lymphatic vascular biology, with a focus on cardiovascular disease. © 2016 American Heart Association, Inc.

Generation of Recombinant Human AChE OP-Scavengers with Extended Circulatory Longevity

DTIC Science & Technology

2006-11-01

PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Avigdor Shafferman Ph.D. 5d. PROJECT NUMBER 5e. TASK NUMBER E-Mail: avigdor...glycans of rHuAChE, and in particular the distal termini of these glycan 8 projections , constitute a major factor in determining the circulatory...experiments funded by sources other than the USAMRMC contract, since they may have a major impact on the present project . Section III focuses on the

Is there an association of circulatory hospitalizations independent of mining employment in coal-mining and non-coal-mining counties in west virginia?

PubMed

Talbott, Evelyn O; Sharma, Ravi K; Buchanich, Jeanine; Stacy, Shaina L

2015-04-01

Exposures associated with coal mining activities, including diesel fuel exhaust, products used in coal processing, and heavy metals and other forms of particulate matter, may impact the health of nearby residents. We investigated the relationships between county-level circulatory hospitalization rates (CHRs) in coal and non-coal-mining communities of West Virginia, coal production, coal employment, and sociodemographic factors. Direct age-adjusted CHRs were calculated using West Virginia hospitalizations from 2005 to 2009. Spatial regressions were conducted to explore associations between CHR and total, underground, and surface coal production. After adjustment, neither total, nor surface, nor underground coal production was significantly related to rate of hospitalization for circulatory disease. Our findings underscore the significant role sociodemographic and behavioral factors play in the health and well-being of coal mining communities.

Is heart transplantation after circulatory death compatible with the dead donor rule?

PubMed

Nair-Collins, Michael; Miller, Franklin G

2016-05-01

Dalle Ave et al (2016) provide a valuable overview of several protocols for heart transplantation after circulatory death. However, their analysis of the compatibility of heart donation after circulatory death (DCD) with the dead donor rule (DDR) is flawed. Their permanence-based criteria for death, which depart substantially from established law and bioethics, are ad hoc and unfounded. Furthermore, their analysis is self-defeating, because it undercuts the central motivation for DDR as both a legal and a moral constraint, rendering the DDR vacuous and trivial. Rather than devise new and ad hoc criteria for death for the purpose of rendering DCD nominally consistent with DDR, we contend that the best approach is to explicitly abandon DDR. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Addressing Consent Issues in Donation After Circulatory Determination of Death.

PubMed

Overby, Kim J; Weinstein, Michael S; Fiester, Autumn

2015-01-01

Given the widening gap between the number of individuals on transplant waiting lists and the availability of donated organs, as well as the recent plateau in donations based on neurological criteria (i.e., brain death), there has been a growing interest in expanding donation after circulatory determination of death. While the prevalence of this form of organ donation continues to increase, many thorny ethical issues remain, often creating moral distress in both clinicians and families. In this article, we address one of these issues, namely, the challenges surrounding patient and surrogate informed consent for donation after circulatory determination of death. First we discuss several general concerns regarding consent related to this form of organ donation, and then we address additional issues that are unique to three different patient categories: adult patients with medical decision-making capacity or potential capacity, adult patients who lack capacity, and pediatric patients.

The First Organ-Based Ontology for Arthropods (Ontology of Arthropod Circulatory Systems - OArCS) and its Integration into a Novel Formalization Scheme for Morphological Descriptions.

PubMed

Wirkner, Christian S; Göpel, Torben; Runge, Jens; Keiler, Jonas; Klussmann-Fricke, Bastian-Jesper; Huckstorf, Katarina; Scholz, Stephan; Mikó, István; J Yoder, Matthew; Richter, Stefan

2017-09-01

Morphology, the oldest discipline in the biosciences, is currently experiencing a renaissance in the field of comparative phenomics. However, morphological/phenotypic research still suffers on various levels from a lack of standards. This shortcoming, first highlighted as the "linguistic problem of morphology", concerns the usage of terminology and also the need for formalization of morphological descriptions themselves, something of paramount importance not only to the field of morphology but also when it comes to the use of phenotypic data in systematics and evolutionary biology. We therefore argue, that for morphological descriptions, the basis of all systematic and evolutionary interpretations, ontologies need to be utilized which are based exclusively on structural qualities/properties and which in no case include statements about homology and/or function. Statements about homology and function constitute interpretations on a different or higher level. Based on these "anatomy ontologies", further ontological dimensions (e.g., referring to functional properties or homology) may be exerted for a broad use in evolutionary phenomics. To this end we present the first organ-based ontology for the most species-rich animal group, the Arthropoda. Our Ontology of Arthropod Circulatory Systems (OArCS) contains a comprehensive collection of 383 terms (i.e., labels) tied to 296 concepts (i.e., definitions) collected from the literature on phenotypic aspects of circulatory organ features in arthropods. All of the concepts used in OArCS are based exclusively on structural features, and in the context of the ontology are independent of homology and functional assumptions. We cannot rule out that in some cases, terms are used which in traditional usage and previous accounts might have implied homology and/or function (e.g. heart, sternal artery). Concepts are composed of descriptive elements that are used to classify observed instances into the organizational framework of the ontology. That is, descriptions in ontologies are only descriptions of individuals if they are necessary/and or sufficient representations of attributes (independently) observed and recorded for an individual. In addition, we here present for the first time an entirely new approach to formalizing phenotypic research, a semantic model for the description of a complex organ system in a highly disparate taxon, the arthropods. We demonstrate this with a formalized morphological description of the hemolymph vascular system in one specimen of the European garden spider Araneus diadematus. Our description targets five categories of descriptive statement: "position", "spatial relationships", "shape", "constituents", and "connections", as the corresponding formalizations constitute exemplary patterns useful not only when talking about the circulatory system, but also in descriptions in general. The downstream applications of computer-parsable morphological descriptions are widespread, with their core utility being the fact that they make it possible to compare collective description sets in computational time, that is, very quickly. Among other things, this facilitates the identification of phenotypic plasticity and variation when single individuals are compared, the identification of those traits which correlate between and within taxa, and the identification of links between morphological traits and genetic (using GO, Gene Ontology) or environmental (using ENVO, Environmental Ontology) factors. [Arthropoda; concept; function; hemolymph vascular system; homology; terminology.]. © The Author(s) 2017. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Biomedical Science, Unit III: The Circulatory System in Health and Science. The Heart and Blood Vessels; Blood and Its Properties; The Urinary Tract. Student Text. Revised Version, 1976.

ERIC Educational Resources Information Center

Biomedical Interdisciplinary Curriculum Project, Berkeley, CA.

This student text presents instructional materials for a unit of science within the Biomedical Interdisciplinary Curriculum Project (BICP), a two-year interdisciplinary precollege curriculum aimed at preparing high school students for entry into college and vocational programs leading to a career in the health field. Lessons concentrate on the…

Biomedical Science, Unit III: The Circulatory System in Health and Science. The Heart and Blood Vessels; Blood and Its Properties; The Urinary Tract. Instructor's Manual. Revised Version, 1976.

ERIC Educational Resources Information Center

Biomedical Interdisciplinary Curriculum Project, Berkeley, CA.

This instructor's manual presents lesson plans for a unit of science within the Biomedical Interdisciplinary Curriculum Project (BICP), a two-year interdisciplinary precollege curriculum aimed at preparing high school students for entry into college and vocational programs leading to a career in the health field. Lessons concentrate on the…

Biomedical Science, Unit III: The Circulatory System in Health and Science. The Heart and Blood Vessels; Blood and Its Properties; The Urinary Tract. Laboratory Manual. Revised Version, 1976.

ERIC Educational Resources Information Center

Biomedical Interdisciplinary Curriculum Project, Berkeley, CA.

This laboratory manual presents activities for a unit of science within the Biomedical Interdisciplinary Curriculum Project (BICP), a two-year interdisciplinary precollege curriculum aimed at preparing high school students for entry into college and vocational programs leading to a career in the health field. These twenty-five laboratory…

[Effects of ethanol on circulatory system].

PubMed

Jelski, Wojciech; Alizade Sani, Tufik; Szmitkowski, Maciej

2006-09-01

Moderate alcohol consumption decreases the risk of coronary heart disease (CHD). Epidemiological studies indicate that consumption of alcohol at the level 20-30 g per day can reduce risk of CHD by at least 20-25%. The mechanism of this protection has been associated with an increase in the level of HDL-cholesterol. Second of the proposed mechanisms of the protective effect of moderate alcohol intake is its beneficial effect on homeostasis.

Design of a right ventricular mock circulation loop as a test bench for right ventricular assist devices.

PubMed

Mueller, Indra; Jansen-Park, So-Hyun; Neidlin, Michael; Steinseifer, Ulrich; Abel, Dirk; Autschbach, Rüdiger; Rossaint, Rolf; Schmitz-Rode, Thomas; Sonntag, Simon Johannes

2017-04-01

Right heart failure (RHF), e.g. due to pulmonary hypertension (PH), is a serious health issue with growing occurrence and high mortality rate. Limited efficacy of medication in advanced stages of the disease constitutes the need for mechanical circulatory support of the right ventricle (RV). An essential contribution to the process of developing right ventricular assist devices (RVADs) is the in vitro test bench, which simulates the hemodynamic behavior of the native circulatory system. To model healthy and diseased arterial-pulmonary hemodynamics in adults (mild and severe PH and RHF), a right heart mock circulation loop (MCL) was developed. Incorporating an anatomically shaped silicone RV and a silicone atrium, it not only enables investigations of hemodynamic values but also suction events or the handling of minimal invasive RVADs in an anatomical test environment. Ventricular pressure-volume loops of all simulated conditions as well as pressure and volume waveforms were recorded and compared to literature data. In an exemplary test, an RVAD was connected to the apex to further test the feasibility of studying such devices with the developed MCL. In conclusion, the hemodynamic behavior of the native system was well reproduced by the developed MCL, which is a useful basis for future RVAD tests.

Leaving Sweden behind: Gains in life expectancy in Canada.

PubMed

Auger, Nathalie; Le Serbon, Emilie; Rostila, Mikael

2015-06-01

Sweden and Canada are known for quality of living and exceedingly high life expectancy, but recent data on how these countries compare are lacking. We measured life expectancy in Canada and Sweden during the past decade, and identified factors responsible for changes over time. We calculated life expectancy at birth for Canada and Sweden annually from 2000 to 2010, and determined the ages and causes of death responsible for the gap between the two countries using Arriaga's method. We determined how population growth, ageing, and mortality influenced the number of deaths over time. During 2000-2010, life expectancy in Canada caught up with Sweden for men, and surpassed Sweden by 0.4 years for women. Sweden lost ground owing to a slower reduction in circulatory and tumour mortality after age 65 years compared with Canada. Nonetheless, population ageing increased the number of deaths in Canada, especially for mental and nervous system disorders. In Sweden, the number of deaths decreased. In only one decade, life expectancy in Canada caught up and surpassed Sweden due to rapid improvements in circulatory and tumour mortality. Population ageing increased the number of deaths in Canada, potentially stressing the health care system more than in Sweden. © 2015 the Nordic Societies of Public Health.

Systemic toxicity of ropivacaine during ovine pregnancy.

PubMed

Santos, A C; Arthur, G R; Pedersen, H; Morishima, H O; Finster, M; Covino, B G

1991-07-01

Ropivacaine is a new amide local anesthetic structurally related to bupivacaine and mepivacaine. Its potency and duration of action are similar to those of bupivacaine but its therapeutic index may be greater. Since pregnancy enhances the cardiotoxicity of bupivacaine, the current study was devised to compare the toxicity of ropivacaine in chronically instrumented nonpregnant and pregnant ewes during continuous intravenous infusion of the drug at the rate of 0.5 mg.kg-1.min-1. In all animals, symptoms of local anesthetic toxicity occurred in the usual order--convulsions, hypotension, apnea, and circulatory collapse. There were no significant differences between the two groups of animals in the doses and plasma concentrations of ropivacaine associated with each toxic manifestations. For example, circulatory collapse occurred at a mean dose of 11.3 +/- 1.1 mg.kg-1 in nonpregnant and 12.4 +/- 0.9 mg.kg-1 in pregnant animals, with corresponding plasma concentrations of 7.3 +/- 0.3 and 9.6 +/- 2.1 micrograms.ml-1 (P = not significant). Protein binding of ropivacaine in the concentration range associated with toxic manifestations was similar in sera obtained from nonpregnant and pregnant ewes. In conclusion, ovine pregnancy does not enhance the systemic toxicity of ropivacaine, possibly because of an absence of gestation-related increase in the availability of free drug.

Cause-specific mortality according to urine albumin creatinine ratio in the general population.

PubMed

Skaaby, Tea; Husemoen, Lise Lotte Nystrup; Ahluwalia, Tarunveer Singh; Rossing, Peter; Jørgensen, Torben; Thuesen, Betina Heinsbæk; Pisinger, Charlotta; Rasmussen, Knud; Linneberg, Allan

2014-01-01

Urine albumin creatinine ratio, UACR, is positively associated with all-cause mortality, cardiovascular disease and diabetes in observational studies. Whether a high UACR is also associated with other causes of death is unclear. We investigated the association between UACR and cause-specific mortality. We included a total of 9,125 individuals from two population-based studies, Monica10 and Inter99, conducted in 1993-94 and 1999-2001, respectively. Urine albumin creatinine ratio was measured from spot urine samples by standard methods. Information on causes of death was obtained from The Danish Register of Causes of Death until 31 December 2010. There were a total of 920 deaths, and the median follow-up was 11.3 years. Multivariable Cox regression analyses with age as underlying time axis showed statistically significant positive associations between UACR status and risk of all-cause mortality, endocrine nutritional and metabolic diseases, mental and behavioural disorders, diseases of the circulatory system, and diseases of the respiratory system with hazard ratios 1.56, 6.98, 2.34, 2.03, and 1.91, for the fourth UACR compared with the first, respectively. Using UACR as a continuous variable, we also found a statistically significant positive association with risk of death caused by diseases of the digestive system with a hazard ratio of 1.02 per 10 mg/g higher UACR. We found statistically significant positive associations between baseline UACR and death from all-cause mortality, endocrine nutritional and metabolic diseases, and diseases of the circulatory system and possibly mental and behavioural disorders, and diseases of the respiratory and digestive system.

Alkaline Phosphatase for the Prevention of Intestinal and Renal Injury in a Rat Model of Cardiopulmonary Bypass with Deep Hypothermic Circulatory Arrest

DTIC Science & Technology

2017-09-01

primary outcome), physiologic, and biomarker evidence of intestinal and kidney injury in this model with administration of escalating doses of bovine...these techniques is necessary for surgical repair, the associated ischemia-reperfusion injury to the intestines and kidneys can lead to substantial...prevention of intestinal and kidney injury after pediatric cardiopulmonary bypass with deep hypothermic circulatory arrest. In this model, we place 5-10kg

Pathophysiological roles of peroxynitrite in circulatory shock

PubMed Central

Szabó, Csaba; Módis, Katalin

2014-01-01

Summary Peroxynitrite is a reactive oxidant produced from nitric oxide (NO) and superoxide, which reacts with proteins, lipids and DNA and promotes cytotoxic and pro-inflammatory responses. Here we overview the role of peroxynitrite in various forms of circulatory shock. Immunohistochemical and biochemical evidence demonstrate the production of peroxynitrite in various experimental models of endotoxic and hemorrhagic shock, both in rodents and in large animals. In addition, biological markers of peroxynitrite have been identified in human tissues after circulatory shock. Peroxynitrite can initiate toxic oxidative reactions in vitro and in vivo. Initiation of lipid peroxidation, direct inhibition of mitochondrial respiratory chain enzymes, inactivation of glyceraldehyde-3-phosphate dehydrogenase, inhibition of membrane Na+/K+ ATP-ase activity, inactivation of membrane sodium channels, and other oxidative protein modifications contribute to the cytotoxic effect of peroxynitrite. In addition, peroxynitrite is a potent trigger of DNA strand breakage, with subsequent activation of the nuclear enzyme poly (ADP-ribose) polymerase (PARP), which promotes cellular energetic collapse and cellular necrosis. Additional actions of peroxynitrite that contribute to the pathogenesis of shock include inactivation of catecholamines and catecholamine receptors (leading to vascular failure), endothelial and epithelial injury (leading to endothelial and epithelial hyper-permeability and barrier dysfunction) as well as myocyte injury (contributing to loss of cardiac contractile function). Neutralization of peroxynitrite with potent peroxynitrite decomposition catalysts provides cytoprotective and beneficial effects in rodent and large animal models of circulatory shock. PMID:20523270

How do plants achieve immunity? Defence without specialized immune cells.

PubMed

Spoel, Steven H; Dong, Xinnian

2012-01-25

Vertebrates have evolved a sophisticated adaptive immune system that relies on an almost infinite diversity of antigen receptors that are clonally expressed by specialized immune cells that roam the circulatory system. These immune cells provide vertebrates with extraordinary antigen-specific immune capacity and memory, while minimizing self-reactivity. Plants, however, lack specialized mobile immune cells. Instead, every plant cell is thought to be capable of launching an effective immune response. So how do plants achieve specific, self-tolerant immunity and establish immune memory? Recent developments point towards a multilayered plant innate immune system comprised of self-surveillance, systemic signalling and chromosomal changes that together establish effective immunity.

Non-invasive control of influence of polyethylene glycol on transport function of fluorescent colored liposomal nanoparticles

NASA Astrophysics Data System (ADS)

Stelmashchuk, O.; Zherebtsov, E.; Zherebtsova, A.; Kuznetsova, E.; Vinokurov, A.; Dunaev, A.; Mamoshin, A.; Snimshchikova, I.; Borsukov, A.; Bykov, A.; Meglinski, I.

2017-03-01

The studies were carried out on groups of clinically healthy mice line of outbred CD-1 stock. The model animals were divided into 2 groups and received experimental liposomal formulations. Using the method of fluorescence spectroscopy, we investigated the effectiveness of penetration into the circulatory system of fluorescently stained liposomes with polyethylene glycol (PEG) and without PEG when administered orally. Fluorescence channel with a fiber probe series of multifunctional laser non-invasive diagnostic system "LAKK-M" (SPE "LAZMA" Ltd, Russia) was used as the measuring equipment.

[Analysis of Kudiezi injection's security literature].

PubMed

Chang, Yan-Peng; Xie, Yan-Ming

2012-09-01

By retrieving the relevant database, aim was to achieve the security reported of Kudiezi injection (Yueanxin). To analysis the gender, age, underlying disease, medication dosage, solvent, adverse event/adverse reaction time of occurrence, clinical presentation of patients, It was found the adverse event/adverse reaction usually occur in older people, involving the organs and systems include skin and its appendages, digestive system, nervous system, circulatory system, respiratory system, systemic reaction, part of the adverse event/adverse reaction's cause were not according to the instructions. It was found on the adverse event/adverse reaction of the judgment on the lack of objective evidence, to produce certain effect for objective evaluation of security of Kudiezi injection (Yueanxin).

Imaging of cardiovascular dynamics in early mouse embryos with swept source optical coherence tomography

NASA Astrophysics Data System (ADS)

Larina, Irina V.; Liebling, Michael; Dickinson, Mary E.; Larin, Kirill V.

2009-02-01

Congenital cardiovascular defects are very common, occurring in 1% of live births, and cardiovascular failures are the leading cause of birth defect-related deaths in infants. To improve diagnostics, prevention and treatment of cardiovascular abnormalities, we need to understand not only how cells form the heart and vessels but also how physical factors such as heart contraction and blood flow influence heart development and changes in the circulatory network. Mouse models are an excellent resource for studying cardiovascular development and disease because of the resemblance to humans, rapid generation time, and availability of mutants with cardiovascular defects linked to human diseases. In this work, we present results on development and application of Doppler Swept Source Optical Coherence Tomography (DSS-OCT) for imaging of cardiovascular dynamics and blood flow in the mouse embryonic heart and vessels. Our studies demonstrated that the spatial and temporal resolution of the DSS-OCT makes it possible to perform sensitive measurements of heart and vessel wall movements and to investigate how contractile waves facilitate the movement of blood through the circulatory system.

Ethical Issues in the Use of Extracorporeal Membrane Oxygenation in Controlled Donation After Circulatory Determination of Death.

PubMed

Dalle Ave, A L; Shaw, D M; Bernat, J L

2016-08-01

The use of donor extracorporeal membrane oxygenation (ECMO) to improve graft outcomes by some controlled donation after circulatory determination of death (cDCDD) programs raises ethical issues. We reviewed cDCDD protocols using ECMO and the relevant ethics literature to analyze these issues. It is not obvious that ECMO in cDCDD improves graft outcomes. In our opinion, ECMO implemented before death can interfere with end-of-life care and damage bodily integrity. By restoring systemic circulation, ECMO risks invalidating the preceding declaration of death if brain and cardiac perfusion is not adequately excluded because of malfunction or misplacement of the supradiaphragmatic aortic occlusion balloon. The use of ECMO is not compatible with the acronym DCDD because circulation is restored after the determination of death. Because of these deficiencies, we concluded that other techniques are preferable, such as rapid recovery or in situ cold infusion. If ECMO is performed, it requires a specific informed consent and transparency. © Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

[Etiological analysis and individualized treatment of pharyngeal paraesthesia].

PubMed

Lou, Zhengcai; Gong, Xuhong; Lou, Fangyi; He, Lanjuan; Zhu, Qiaoying

2009-07-01

To analyze the nosazontology of pharyngeal paraesthesia and investigate the treatment. Two hundred and twelve misdiagnosed pharyngeal paraesthesia patients were investigated by history inquiry, routine examination, 24-hour esophageal pH monitoring, barium X-ray of the oesophagus, anxieties-athymic private measuring scale, coefficient of variation of the R-R (CVR-R), bioavailable testosterone detection (Bio-T), erection experiment and questionnaire about man climacteric syndrome. The concomitant symptoms and positions of pharyngeal paresthesia were also studied. We adopted individuallized sequential multi-therapy for every patient according to the cause of disease. The cause of disease within 212 cases of pharyngeal paraesthesia included 62 psychic trauma, 32 endocrine system disease, 106 upper gastrointestinal disease, circulatory disease, 9 circulatory disease, 3 idiopathic. With individualized treatment, 110 cases had fully recovered, 63 cases excellence and 31 cases utility, and the efficiency rate was 96.23%. Pharyngeal paraesthesia can be caused by several factors. Thorough examination and comprehensive analysis should be applied to those incurable patient who has been treated for a long time. Short course of treatment and irrational drug use are the main causes of short-term recurrence and unsatisfactory curative effect.

A first-in-man study of the Reitan catheter pump for circulatory support in patients undergoing high-risk percutaneous coronary intervention.

PubMed

Smith, Elliot J; Reitan, Oyvind; Keeble, Thomas; Dixon, Kerry; Rothman, Martin T

2009-06-01

To investigate the safety of a novel percutaneous circulatory support device during high-risk percutaneous coronary intervention (PCI). The Reitan catheter pump (RCP) consists of a catheter-mounted pump-head with a foldable propeller and surrounding cage. Positioned in the descending aorta the pump creates a pressure gradient, reducing afterload and enhancing organ perfusion. Ten consecutive patients requiring circulatory support underwent PCI; mean age 71 +/- 9; LVEF 34% +/- 11%; jeopardy score 8 +/- 2.3. The RCP was inserted via the femoral artery. Hemostasis was achieved using Perclose sutures. PCI was performed via the radial artery. Outcomes included in-hospital death, MI, stroke, and vascular injury. Hemoglobin (Hb), free plasma Hb (fHb), platelets, and creatinine (cre) were measured pre PCI and post RCP removal. The pump was inserted and operated successfully in 9/10 cases (median 79 min). Propeller rotation at 10,444 +/- 1,424 rpm maintained an aortic gradient of 9.8 +/- 2 mm Hg. Although fHb increased, there was no significant hemolysis (4.7 +/- 2.4 mg/dl pre vs. 11.9 +/- 10.5 post, P = 0.04, reference 20 mg/dl). Platelets were unchanged (pre 257 +/- 74 x 10(9) vs. 245 +/- 63, P = NS). Renal function improved (cre pre 110 +/- 27 micromol/l vs. 99 +/- 28, P = 0.004). The RCP was not used in one patient following femoral introducer sheath related aortic dissection. All PCI procedures were successful with no deaths or strokes, one MI, and no vascular complications following pump removal. The RCP can be used safely in high-risk PCI patients. This device may be an alternative to other percutaneous systems when substantial cardiac support is needed. (c) 2009 Wiley-Liss, Inc.

Similar cerebral protective effectiveness of antegrade and retrograde cerebral perfusion combined with deep hypothermia circulatory arrest in aortic arch surgery: a meta-analysis and systematic review of 5060 patients.

PubMed

Hu, Zhipeng; Wang, Zhiwei; Ren, Zongli; Wu, Hongbing; Zhang, Min; Zhang, Hao; Hu, Xiaoping

2014-08-01

Our objective was to determine if antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP) combined with deep hypothermia circulatory arrest in aortic arch surgery results in different mortality and neurologic outcomes. The Cochrane Library, Medline, EMBASE, CINAHL, Web of Science, and the Chinese Biomedical Database were searched for studies reporting on postoperative strokes, permanent neurologic dysfunction, temporary neurologic dysfunction, and all causes mortality within 30 days postoperation in aortic arch surgery. Meta-analysis for effect size, t test, and I(2) for detecting heterogeneity and sensitivity analysis for assessing the relative influence of each study was performed. Fifteen included studies encompassed a total of 5060 patients of whom 2855 were treated with deep hypothermic circulatory arrest plus ACP and 1897 were treated with deep hypothermic circulatory arrest plus RCP. Pooled analysis showed no significant statistical difference (P > .01) of 30-day mortality, permanent neurologic dysfunction, and transient neurologic dysfunction in the 2 groups. Before sensitivity analysis, postoperative stroke incidence in the ACP group was higher than in the RCP group (7.2% vs 4.7%; P < .01). After a study that included a different percentage of patients with a history of central neurologic events in the 2 groups was ruled out, postoperative stroke incidence in the 2 groups also showed no significant statistical difference (P > .01). ACP and RCP provide similar cerebral protective effectiveness combined with deep hypothermia circulatory arrest and could be selected according to the actual condition in aortic arch surgery. A high-quality randomized controlled trial is urgently needed to confirm this conclusion, especially for stroke morbidity following ACP or RCP. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Imbalance of arginine and asymmetric dimethylarginine is associated with markers of circulatory failure, organ failure and mortality in shock patients.

PubMed

Visser, Marlieke; Vermeulen, Mechteld A R; Richir, Milan C; Teerlink, Tom; Houdijk, Alexander P J; Kostense, Piet J; Wisselink, Willem; de Mol, Bas A J M; van Leeuwen, Paul A M; Oudemans-van Straaten, Heleen M

2012-05-01

In shock, organ perfusion is of vital importance because organ oxygenation is at risk. NO, the main endothelial-derived vasodilator, is crucial for organ perfusion and coronary patency. The availability of NO might depend on the balance between a substrate (arginine) and an inhibitor (asymmetric dimethylarginine; ADMA) of NO synthase. Therefore, we investigated the relationship of arginine, ADMA and their ratio with circulatory markers, disease severity, organ failure and mortality in shock patients. In forty-four patients with shock (cardiogenic n 17, septic n 27), we prospectively measured plasma arginine and ADMA at intensive care unit admission, Acute Physiology and Chronic Health Evaluation (APACHE) II-(predicted mortality) and Sequential Organ Failure Assessment (SOFA) score, and circulatory markers to investigate their relationship. Arginine concentration was decreased (34·6 (SD 17·9) μmol/l) while ADMA concentration was within the normal range (0·46 (SD 0·18) μmol/l), resulting in a decrease in the arginine:ADMA ratio. The ratio correlated with several circulatory markers (cardiac index, disseminated intravascular coagulation, bicarbonate, lactate and pH), APACHE II and SOFA score, creatine kinase and glucose. The arginine:ADMA ratio showed an association (OR 0·976, 95 % CI 0·963, 0·997, P = 0·025) and a diagnostic accuracy (area under the curve 0·721, 95 % CI 0·560, 0·882, P = 0·016) for hospital mortality, whereas the arginine or ADMA concentration alone or APACHE II-predicted mortality failed to do so. In conclusion, in shock patients, the imbalance of arginine and ADMA is related to circulatory failure, organ failure and disease severity, and predicts mortality. We propose a pathophysiological mechanism in shock: the imbalance of arginine and ADMA contributes to endothelial and cardiac dysfunction resulting in poor organ perfusion and organ failure, thereby increasing the risk of death.

[Cerebral oximetry in pulmonary thromboendarterectomy with circulatory arrest].

PubMed

Catalán Escudero, P; González Román, A; Serra Ruiz, C N; Barbero Mielgo, M; García Fernández, J

2014-02-01

Pulmonary thromboendarterectomy is an uncommon procedure and should be performed with circulatory arrest. One of the major concerns is the postoperative central neurological injuries. Perioperative brain oxygen monitoring is advisable in this surgical procedure for the early detection of brain hypoperfusion episodes and their intensity as well as any other postoperative episodes that can deteriorate the neurological outcome. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Utilization of organs from donors after circulatory death for vascularized pancreas and islet of Langerhans transplantation: recommendations from an expert group.

PubMed

Berney, Thierry; Boffa, Catherine; Augustine, Titus; Badet, Lionel; de Koning, Eelco; Pratschke, Johann; Socci, Carlo; Friend, Peter

2016-07-01

Donation after circulatory death (DCD) donors are increasingly being used as a source of pancreas allografts for vascularized organ and islet transplantation. We provide practice guidelines aiming to increase DCD pancreas utilization. We review risk assessment and donor selection criteria. We report suggested factors in donor and recipient clinical management and provide an overview of the activities and outcomes of vascularized pancreas and islet transplantation. © 2015 Steunstichting ESOT.

[Antihypoxic and antioxidative properties of bemitil].

PubMed

Plotnikov, M B; Saratikov, A S; Plotnikova, T M; Khazanov, V A; Panina, O P

1989-05-01

The authors discovered antihypoxic properties of the bemitil (pretreatment injections 50 mg/kg intraperitoneally) in the experiments on rats with the circulatory or hypoxic hypoxia. There was limitation of pO decrease and diene conjugates and Schiff bases production increase with the drug in the circulatory hypoxia conditions. Bemitil restricted malondialdehyde accumulation in the rat brain homogenate under the activation of free radicals processes. In the mitochondrial suspension incubation similar effect of the medicine was accompanied with limitation of organelle degradation. Bemitil showed no antiradical activity.

Novel Method for Exchange of Impella Circulatory Assist Catheter: The "Trojan Horse" Technique.

PubMed

Phillips, Colin T; Tamez, Hector; Tu, Thomas M; Yeh, Robert W; Pinto, Duane S

2017-07-01

Patients with an indwelling Impella may require escalation of hemodynamic support or exchange to another circulatory assistance platform. As such, preservation of vascular access is preferable in cases where anticoagulation cannot be discontinued or to facilitate exchange to an alternative catheter or closure device. Challenges exist in avoiding bleeding and loss of wire access in these situations. We describe a single-access "Trojan Horse" technique that minimizes bleeding while maintaining arterial access for rapid exchange of this percutaneous ventricular assist device.

Accelerated heart function recovery after therapeutic plasma exchange in patient treated with biventricular mechanical circulatory support for severe peripartum cardiomyopathy.

PubMed

Łasińska-Kowaraa, Magdalena; Lango, Romuald; Kowalik, Maciej; Jarmoszewicz, Krzysztof

2014-12-01

We describe a case of severe peripartum cardiomyopathy treated with biventricular mechanical circulatory support, where rapid haemodynamic recovery was observed after therapeutic plasma exchange, used as an adjunct to the inhibition of prolactin release. The patient recovered and after 2 months was discharged from the hospital without clinical symptoms of heart disease. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

ABO blood group antibody levels in infants exposed to mechanical circulatory support.

PubMed

Guynes, Anthony; Delaney, Meghan; McMullan, David M; Townsend-McCall, Dee; Kemna, Mariska; Boucek, Robert; Law, Yuk M

2014-01-01

ABO sensitization is a barrier to ABO-incompatible heart transplantation in infants. We investigate the development of ABO antibodies in infants with and without mechanical circulatory support (MCS) during their waiting period. Although the proportion of patients with antibodies was similar between the groups, the median age at antibody detection was only 9 days (6-198) for MCS vs. 223 days (28-367) for non-MCS patients (P = 0.028), suggesting MCS is associated with earlier ABO antibody detection.

Importance of integrating nanotechnology with pharmacology and physiology for innovative drug delivery and therapy - an illustration with firsthand examples.

PubMed

Zhang, Rui Xue; Li, Jason; Zhang, Tian; Amini, Mohammad A; He, Chunsheng; Lu, Brian; Ahmed, Taksim; Lip, HoYin; Rauth, Andrew M; Wu, Xiao Yu

2018-05-01

Nanotechnology has been applied extensively in drug delivery to improve the therapeutic outcomes of various diseases. Tremendous efforts have been focused on the development of novel nanoparticles and delineation of the physicochemical properties of nanoparticles in relation to their biological fate and functions. However, in the design and evaluation of these nanotechnology-based drug delivery systems, the pharmacology of delivered drugs and the (patho-)physiology of the host have received less attention. In this review, we discuss important pharmacological mechanisms, physiological characteristics, and pathological factors that have been integrated into the design of nanotechnology-enabled drug delivery systems and therapies. Firsthand examples are presented to illustrate the principles and advantages of such integrative design strategies for cancer treatment by exploiting 1) intracellular synergistic interactions of drug-drug and drug-nanomaterial combinations to overcome multidrug-resistant cancer, 2) the blood flow direction of the circulatory system to maximize drug delivery to the tumor neovasculature and cells overexpressing integrin receptors for lung metastases, 3) endogenous lipoproteins to decorate nanocarriers and transport them across the blood-brain barrier for brain metastases, and 4) distinct pathological factors in the tumor microenvironment to develop pH- and oxidative stress-responsive hybrid manganese dioxide nanoparticles for enhanced radiotherapy. Regarding the application in diabetes management, a nanotechnology-enabled closed-loop insulin delivery system was devised to provide dynamic insulin release at a physiologically relevant time scale and glucose levels. These examples, together with other research results, suggest that utilization of the interplay of pharmacology, (patho-)physiology and nanotechnology is a facile approach to develop innovative drug delivery systems and therapies with high efficiency and translational potential.

Blood pressure support in the very low-birth-weight infant during the first week of life.

PubMed

Nist, Marliese Dion; Backes, Carl H; Moorehead, Pamela; Wispe, Jonathan

2012-06-01

The immature cardiovascular system of very preterm infants predisposes them to low systemic blood flow during the first week of life, a state that may be damaging to multiple organ systems. There are many treatment strategies for the maintenance of cardiovascular equilibrium in these infants, each with its own advantages and risks. Caregivers are responsible for assessing the circulatory status of each patient and evaluating the effectiveness of interventions aimed at maintaining adequate systemic blood flow. Therefore, it is important to have an understanding of the mechanics of transitional circulation, the relationship between blood pressure and systemic blood flow, and the therapies used to treat infants with compromised organ perfusion.

EVAHEART: an implantable centrifugal blood pump for long-term circulatory support.

PubMed

Yamazaki, Kenji; Kihara, Shinichiro; Akimoto, Takehide; Tagusari, Osamu; Kawai, Akihiko; Umezu, Mitsuo; Tomioka, Jun; Kormos, Robert L; Griffith, Bartley P; Kurosawa, Hiromi

2002-11-01

We developed "EVAHEART": a compact centrifugal blood pump system as an implantable left ventricular assist device for long-term circulatory support. The 55 x 64 mm pump is made from pure titanium, and weighs 370 g. The entire blood-contacting surface is covered with an anti-thrombogenic coating of diamond like carbon (DLC) or 2-methacryloyloxyethyl phosphorylcholine (MPC) to improve blood compatibility. Flows exceeding 12 L/min against 100 mmHg pressure at 2600 rpm was measured. A low-temperature mechanical seal with recirculating cooling system is used to seal the shaft. EVAHEART demonstrated an acceptably low hemolysis rate with normalized index of hemolysis of 0.005 +/- 0.002 g/100L. We evaluated the pump in long-term in-vivo experiments with seven calves. Via left thoracotomy, we conducted left ventricular apex-descending aorta bypass, placing the pump in the left thoracic cavity. Pump flow rates was maintained at 5-9 L/min, pump power consumption remained stable at 9-10 W in all cases, plasma free Hb levels were less than 15 mg/dl, and the seal system showed good seal capability throughout the experiments. The calves were sacrificed on schedule on postoperative day 200, 222, 142, 90, 151, 155, and 133. No thrombi formed on the blood contacting surface with either the DLC or MPC coating, and no major organ thromboembolisms occurred except for a few small renal infarcts. EVAHEART centrifugal blood pump demonstrated excellent performance in long-term in-vivo experiments.

CANNULATION STRATEGY FOR AORTIC ARCH RECONSTRUCTION USING DEEP HYPOTHERMIC CIRCULATORY ARREST

PubMed Central

de Zéicourt, Diane; Jung, Philsub; Horner, Marc; Pekkan, Kerem; Kanter, Kirk R.; Yoganathan, Ajit P.

2013-01-01

Background Aortic arch reconstruction in neonates is commonly performed using deep hypothermic circulatory arrest. However, concerns have arisen regarding potential adverse neurologic outcomes from this complex procedure, raising questions as to best arterial cannulation approach for cerebral perfusion and effective systemic hypothermia. In this study, we use computational fluid dynamics to investigate the impact of different cannulation strategies in neonates. Methods Using a realistic hypoplastic neonatal aorta template as the base geometry, four different cannulation options were investigated: 1) right innominate artery, 2) innominate root, 3) patent ductus arteriosus (PDA), or 4) both innominate root and PDA. Performance was evaluated based on the numerically predicted cerebral and systemic flow distributions compared with physiological perfusion under neonatal conditions. Results The four cannulation strategies were associated with different local hemodynamics, but this did not translate into any significant effect on the measured flow distributions. The largest difference only represented 0.8% of the cardiac output and was measured in the innominate artery, which received 23.2% of the cardiac output in Option 3 vs. 24% in Option 4. PA snaring benefited all systemic vessels uniformly. Conclusion Due to the very high vascular resistances in neonates, flow distribution to the different vascular beds was dictated by the downstream vascular resistances rather than the cannulation strategy, allowing the surgical team to choose their method of preference. However, patients with aortic coarctation warrant further investigation and will most likely benefit from a two cannulae approach (Option 4). PMID:22608717

A mock circulatory system with physiological distribution of terminal resistance and compliance: application for testing the intra-aortic balloon pump.

PubMed

Kolyva, Christina; Biglino, Giovanni; Pepper, John R; Khir, Ashraf W

2012-03-01

A mock circulatory system (MCS) was designed to replicate a physiological environment for in vitro testing and was assessed with the intra-aortic balloon pump (IABP). The MCS was comprised of an artificial left ventricle (LV), connected to a 14-branch polyurethane-compound aortic model. Physiological distribution of terminal resistance and compliance according to published data was implemented with capillary tubes of different sizes and syringes of varying air volume, respectively, fitted at the outlets of the branches. The ends of the aortic branches were connected to a common tube representing the venous system and an overhead reservoir provided atrial pressure. An IABP operating a 40-cc balloon was set to counterpulsate with the LV. Total arterial compliance of the system was 0.94 mL/mm Hg and total arterial resistance was 20.3 ± 3.3 mm Hg/L/min. At control, physiological flow distribution was achieved and both mean and phasic aortic pressure and flow were physiological. With the IABP, aortic pressure exhibited the major features of counterpulsation: diastolic augmentation during inflation, inflection point at onset of deflation, and end-diastolic reduction at the end of deflation. The contribution of balloon inflation and deflation was also evident on the aortic flow pattern. This MCS was verified to be suitable for IABP testing and with further adaptations it could be used for studying other hemodynamic problems and ventricular assist devices. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

An original valveless artificial heart providing pulsatile flow tested in mock circulatory loops.

PubMed

Tozzi, Piergiorgio; Maertens, Audrey; Emery, Jonathan; Joseph, Samuel; Kirsch, Matthias; Avellan, François

2017-11-24

We present the test bench results of a valveless total artificial heart that is potentially compatible with the pediatric population. The RollingHeart is a valveless volumetric pump generating pulsatile flow. It consists of a single spherical cavity divided into 4 chambers by 2 rotating disks. The combined rotations of both disks produce changes in the volumes of the 4 cavities (suction and ejection). The blood enters/exits the spherical cavity through 4 openings that are symmetrical to the fixed rotation axis of the first disk.Mock circulatory system: The device pumps a 37% glycerin solution through 2 parallel circuits, simulating the pulmonary and systemic circulations. Flow rates are acquired with a magnetic inductive flowmeter, while pressure sensors collect pressure in the left and right outflow and inflow tracts.In vitro test protocol: The pump is run at speeds ranging from 20 to 180 ejections per minute. The waveform of the pressure generated at the inflow and outflow of the 4 chambers and the flow rate in the systemic circulation are measured. At an ejection rate of 178 min-1, the RollingHeart pumps 5.3 L/min for a systemic maximal pressure gradient of 174 mmHg and a pulmonary maximal pressure gradient of 75 mmHg. The power input was 14 W, corresponding to an efficiency of 21%. The RollingHeart represents a new approach in the domain of total artificial heart. This preliminary study endorses the feasibility of a single valveless device acting as a total artificial heart.

Heart Transplant and Mechanical Circulatory Support in Patients With Advanced Heart Failure.

PubMed

Sánchez-Enrique, Cristina; Jorde, Ulrich P; González-Costello, José

2017-05-01

Patients with advanced heart failure have a poor prognosis and heart transplant is still the best treatment option. However, the scarcity of donors, long waiting times, and an increasing number of unstable patients have favored the development of mechanical circulatory support. This review summarizes the indications for heart transplant, candidate evaluation, current immunosuppression strategies, the evaluation and treatment of rejection, infectious prophylaxis, and short and long-term outcomes. Regarding mechanical circulatory support, we distinguish between short- and long-term support and the distinct strategies that can be used: bridge to decision, recovery, candidacy, transplant, and destination therapy. We then discuss indications, risk assessment, management of complications, especially with long-term support, and outcomes. Finally, we discuss future challenges and how the widespread use of long-term support for patients with advanced heart failure will only be viable if their complications and costs are reduced. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

The total artificial heart.

PubMed

Cook, Jason A; Shah, Keyur B; Quader, Mohammed A; Cooke, Richard H; Kasirajan, Vigneshwar; Rao, Kris K; Smallfield, Melissa C; Tchoukina, Inna; Tang, Daniel G

2015-12-01

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient's native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review.

LONG-TERM MECHANICAL CIRCULATORY SUPPORT (DESTINATION THERAPY): ON TRACK TO COMPETE WITH HEART TRANSPLANTATIO?

PubMed Central

Kirklin, James K.; Naftel, David C.; Pagani, Francis D.; Kormos, Robert L.; Stevenson, Lynne; Miller, Marissa; Young, James B.

2012-01-01

Objective(s) Average two-year survival following cardiac transplantation is approximately 80%. The evolution and subsequent approval of larger pulsatile and, more recently, continuous flow mechanical circulatory support (MCS) technology for destination therapy (DT) offers the potential for triage of some patients awaiting cardiac transplantation to DT. Methods The National Heart, Lung and Blood Institute Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) is a national multi-institutional study of chronic mechanical circulatory support. Between June 2006 and December 2011, 127 pulsatile and 1160 continuous flow pumps (24% of total primary LVADs) carried an initial strategy of DT therapy. Results By multivariable analysis, risk factors (p<0.05) for mortality following DT included older age, larger body mass index, history of cancer, history of cardiac surgery, INTERMACS level I (cardiogenic shock), dialysis, increased BUN, use of a pulsatile flow device and use of a RVAD. Among continuous flow LVAD patients who were not in cardiogenic shock, a particularly favorable survival was associated with no cancer, patients not in cardiogenic shock, and BUN < 50, resulting in one and two year survival of 88 and 80%. Conclusions 1) Evolution from pulsatile to continuous flow technology has dramatically improved one and two year survival; 2) Destination Therapy is not appropriate for patients with rapid hemodynamic deterioration; or severe right ventricular failure 4) Important subsets of continuous flow DT patients now enjoy survival which is competitive with heart transplantation out to about two years. PMID:22795459

D-dimer as marker for microcirculatory failure: correlation with LOD and APACHE II scores.

PubMed

Angstwurm, Matthias W A; Reininger, Armin J; Spannagl, Michael

2004-01-01

The relevance of plasma d-dimer levels as marker for morbidity and organ dysfunction in severely ill patients is largely unknown. In a prospective study we determined d-dimer plasma levels of 800 unselected patients at admission to our intensive care unit. In 91% of the patients' samples d-dimer levels were elevated, in some patients up to several hundredfold as compared to normal values. The highest mean d-dimer values were present in the patient group with thromboembolic diseases, and particularly in non-survivors of pulmonary embolism. In patients with circulatory impairment (r=0.794) and in patients with infections (r=0.487) a statistically significant correlation was present between d-dimer levels and the APACHE II score (P<0.001). The logistic organ dysfunction score (LOD, P<0.001) correlated with d-dimer levels only in patients with circulatory impairment (r=0.474). On the contrary, patients without circulatory impairment demonstrated no correlation of d-dimer levels to the APACHE II or LOD score. Taking all patients together, no correlations of d-dimer levels with single organ failure or with indicators of infection could be detected. In conclusion, d-dimer plasma levels strongly correlated with the severity of the disease and organ dysfunction in patients with circulatory impairment or infections suggesting that elevated d-dimer levels may reflect the extent of microcirculatory failure. Thus, a therapeutic strategy to improve the microcirculation in such patients may be monitored using d-dimer plasma levels.

Comparison of outcomes of kidney transplantation from donation after brain death, donation after circulatory death, and donation after brain death followed by circulatory death donors.

PubMed

Chen, Guodong; Wang, Chang; Ko, Dicken Shiu-Chung; Qiu, Jiang; Yuan, Xiaopeng; Han, Ming; Wang, Changxi; He, Xiaoshun; Chen, Lizhong

2017-11-01

There are three categories of deceased donors of kidney transplantation in China, donation after brain death (DBD), donation after circulatory death (DCD), and donation after brain death followed by circulatory death (DBCD) donors. The aim of this study was to compare the outcomes of kidney transplantation from these three categories of deceased donors. We retrospectively reviewed 469 recipients who received deceased kidney transplantation in our hospital from February 2007 to June 2015. The recipients were divided into three groups according to the source of their donor kidneys: DBD, DCD, or DBCD. The primary endpoints were delayed graft function (DGF), graft loss, and patient death. The warm ischemia time was much longer in DCD group compared to DBCD group (18.4 minutes vs 12.9 minutes, P < .001). DGF rate was higher in DCD group than in DBD and DBCD groups (22.5% vs 10.2% and 13.8%, respectively, P = .021). Urinary leakage was much higher in DCD group (P = .049). Kaplan-Meier analysis showed that 1-, 2-, and 3-year patient survivals were all comparable among the three groups. DBCD kidney transplantation has lower incidences of DGF and urinary leakage than DCD kidney transplant. However, the overall patient and graft survival were comparable among DBD, DCD, and DBCD kidney transplantation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Orbit-spin coupling and the interannual variability of global-scale dust storm occurrence on Mars

NASA Astrophysics Data System (ADS)

Shirley, James H.; Mischna, Michael A.

2017-05-01

A new physical hypothesis predicts that a weak coupling of the orbital and rotational motions of extended bodies may give rise to a modulation of circulatory flows within their atmospheres. Driven cycles of intensification and relaxation of large-scale circulatory flows are predicted, with the phasing of these changes linked directly to the rate of change of the orbital angular momentum, dL/dt, with respect to inertial frames. We test the hypothesis that global-scale dust storms (GDS) on Mars may occur when periods of circulatory intensification (associated with positive and negative extrema of the dL/dt waveform) coincide with the southern summer dust storm season on Mars. The orbit-spin coupling hypothesis additionally predicts that the intervening 'transitional' periods, which are characterized by the disappearance and subsequent sign change of dL/dt, may be unfavorable for the occurrence of GDS, when they occur during the southern summer dust storm season. These hypotheses are strongly supported by comparisons between calculated dynamical time series of dL/dt and historic observations. All of the nine known global-scale dust storms on Mars took place during Mars years when circulatory intensification during the dust storm season is 'retrodicted' under the orbit-spin coupling hypothesis. None of the historic global-scale dust storms of our catalog occurred during transitional intervals. Orbit-spin coupling appears to play an important role in the excitation of the interannual variability of the atmospheric circulation of Mars.

Arsenic in drinking water and cerebrovascular disease, diabetes mellitus, and kidney disease in Michigan: a standardized mortality ratio analysis.

PubMed

Meliker, Jaymie R; Wahl, Robert L; Cameron, Lorraine L; Nriagu, Jerome O

2007-02-02

Exposure to arsenic concentrations in drinking water in excess of 300 microg/L is associated with diseases of the circulatory and respiratory system, several types of cancer, and diabetes; however, little is known about the health consequences of exposure to low-to-moderate levels of arsenic (10-100 microg/L). A standardized mortality ratio (SMR) analysis was conducted in a contiguous six county study area of southeastern Michigan to investigate the relationship between moderate arsenic levels and twenty-three selected disease outcomes. Disease outcomes included several types of cancer, diseases of the circulatory and respiratory system, diabetes mellitus, and kidney and liver diseases. Arsenic data were compiled from 9251 well water samples tested by the Michigan Department of Environmental Quality from 1983 through 2002. Michigan Resident Death Files data were amassed for 1979 through 1997 and sex-specific SMR analyses were conducted with indirect adjustment for age and race; 99% confidence intervals (CI) were reported. The six county study area had a population-weighted mean arsenic concentration of 11.00 microg/L and a population-weighted median of 7.58 microg/L. SMR analyses were conducted for the entire six county study area, for only Genesee County (the most populous and urban county), and for the five counties besides Genesee. Concordance of results across analyses is used to interpret the findings. Elevated mortality rates were observed for both males (M) and females (F) for all diseases of the circulatory system (M SMR, 1.11; CI, 1.09-1.13; F SMR, 1.15; CI, 1.13,-1.17), cerebrovascular diseases (M SMR, 1.19; CI, 1.14-1.25; F SMR, 1.19; CI, 1.15-1.23), diabetes mellitus (M SMR, 1.28; CI, 1.18-1.37; F SMR, 1.27; CI, 1.19-1.35), and kidney diseases (M SMR, 1.28; CI, 1.15-1.42; F SMR, 1.38; CI, 1.25-1.52). This is some of the first evidence to suggest that exposure to low-to-moderate levels of arsenic in drinking water may be associated with several of the leading causes of mortality, although further epidemiologic studies are required to confirm the results suggested by this ecologic SMR analysis.

Arsenic in drinking water and cerebrovascular disease, diabetes mellitus, and kidney disease in Michigan: a standardized mortality ratio analysis

PubMed Central

Meliker, Jaymie R; Wahl, Robert L; Cameron, Lorraine L; Nriagu, Jerome O

2007-01-01

Background Exposure to arsenic concentrations in drinking water in excess of 300 μg/L is associated with diseases of the circulatory and respiratory system, several types of cancer, and diabetes; however, little is known about the health consequences of exposure to low-to-moderate levels of arsenic (10–100 μg/L). Methods A standardized mortality ratio (SMR) analysis was conducted in a contiguous six county study area of southeastern Michigan to investigate the relationship between moderate arsenic levels and twenty-three selected disease outcomes. Disease outcomes included several types of cancer, diseases of the circulatory and respiratory system, diabetes mellitus, and kidney and liver diseases. Arsenic data were compiled from 9251 well water samples tested by the Michigan Department of Environmental Quality from 1983 through 2002. Michigan Resident Death Files data were amassed for 1979 through 1997 and sex-specific SMR analyses were conducted with indirect adjustment for age and race; 99% confidence intervals (CI) were reported. Results The six county study area had a population-weighted mean arsenic concentration of 11.00 μg/L and a population-weighted median of 7.58 μg/L. SMR analyses were conducted for the entire six county study area, for only Genesee County (the most populous and urban county), and for the five counties besides Genesee. Concordance of results across analyses is used to interpret the findings. Elevated mortality rates were observed for both males (M) and females (F) for all diseases of the circulatory system (M SMR, 1.11; CI, 1.09–1.13; F SMR, 1.15; CI, 1.13,-1.17), cerebrovascular diseases (M SMR, 1.19; CI, 1.14–1.25; F SMR, 1.19; CI, 1.15–1.23), diabetes mellitus (M SMR, 1.28; CI, 1.18–1.37; F SMR, 1.27; CI, 1.19–1.35), and kidney diseases (M SMR, 1.28; CI, 1.15–1.42; F SMR, 1.38; CI, 1.25–1.52). Conclusion This is some of the first evidence to suggest that exposure to low-to-moderate levels of arsenic in drinking water may be associated with several of the leading causes of mortality, although further epidemiologic studies are required to confirm the results suggested by this ecologic SMR analysis. PMID:17274811

The heart works against gravity

NASA Technical Reports Server (NTRS)

Seymour, R. S.; Hargens, A. R.; Pedley, T. J.

1993-01-01

The circulatory systems of vertebrate animals are closed, and blood leaves and returns to the heart at the same level. It is often concluded, therefore, that the heart works only against the viscous resistance of the system, not against gravity, even in vascular loops above the heart in which the siphon principle operates. However, we argue that the siphon principle does not assist blood flow in superior vascular loops if any of the descending vasculature is collapsible. If central arterial blood pressure is insufficient to support a blood column between the heart and the head, blood flow ceases because of vascular collapse. Furthermore, the siphon principle does not assist the heart even when a continuous stream of blood is flowing in a superior loop. The potential energy gained by blood as it is pumped to the head is lost to friction in partially collapsed descending vessels and thus is not regained. Application of the Poiseuille equation to flow in collapsible vessels is limited; resistance depends on flow rate in partially collapsed vessels with no transmural pressure difference, but flow rate is independent of resistance. Thus the pressure developed by the heart to establish a given flow rate is independent of the resistance occurring in the partially collapsed vessels. The pressure depends only on the height of the blood column and the resistance in the noncollapsed parts of the system. Simple laboratory models, involving water flow in collapsible tubing, dispel the idea that the siphon principle facilitates blood flow and suggest that previously published results may have been affected by experimental artifact.

Circulation kinetics and organ distribution of Hb-vesicles developed as a red blood cell substitute.

PubMed

Sou, Keitaro; Klipper, Robert; Goins, Beth; Tsuchida, Eishun; Phillips, William T

2005-02-01

Phospholipid vesicles encapsulating concentrated human hemoglobin (Hb-vesicles, HbV), also known as liposomes, have a membrane structure similar to that of red blood cells (RBCs). These vesicles circulate in the bloodstream as an oxygen carrier, and their circulatory half-life times (t(1/2)) and biodistribution are fundamental characteristics required for representation of their efficacy and safety as a RBC substitute. Herein, we report the pharmacokinetics of HbV and empty vesicles (EV) that do not contain Hb, in rats and rabbits to evaluate the potential of HbV as a RBC substitute. The samples were labeled with technetium-99m and then intravenously infused into animals at 14 ml/kg to measure the kinetics of HbV elimination from blood and distribution to the organs. The t(1/2) values were 34.8 and 62.6 h for HbV and 29.3 and 57.3 h for EV in rats and rabbits, respectively. At 48 h after infusion, the liver, bone marrow, and spleen of both rats and rabbits had significant concentrations of HbV and EV, and the percentages of the infused dose in these three organs were closely correlated to the circulatory half-life times in elimination phase (t(1/2beta)). Furthermore, the milligrams of HbV per gram of tissue correlated well between rats and rabbits, suggesting that the balance between organ weight and body weight is a fundamental factor determining the pharmacokinetics of HbV. This factor could be used to estimate the biodistribution and the circulation time of HbV in humans, which is estimated to be equal to that in rabbit.

Selective cerebral perfusion prevents abnormalities in glutamate cycling and neuronal apoptosis in a model of infant deep hypothermic circulatory arrest and reperfusion

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

Kajimoto, Masaki; Ledee, Dolena R.; Olson, Aaron K.

Rationale: Deep hypothermic circulatory arrest (DHCA) is often required for the repair of complex congenital cardiac defects in infants. However, DHCA induces neuroapoptosis associated with later development of neurocognitive abnormalities. Selective cerebral perfusion (SCP) theoretically provides superior neural protection possibly through modifications in cerebral substrate oxidation and closely integrated glutamate cycling. Objectives: We tested the hypothesis that SCP modulates glucose entry into the citric acid cycle, and ameliorates abnormalities in glutamate flux which occur in association neuroapoptosis during DHCA. Methods and Results: Eighteen male Yorkshire piglets (age 34-44 days) were assigned randomly to 2 groups of 7 (DHCA or DHCAmore » with SCP for 60 minutes at 18 °C) and 4 control pigs without cardiopulmonary bypass support. After the completion of rewarming from DHCA, 13-Carbon-labeled (13C) glucose as a metabolic tracer was infused. We used gas chromatography-mass spectrometry (GCMS) and nuclear magnetic resonance for metabolic analysis in the frontal cortex. Following 2.5 hours of cerebral reperfusion, we observed similar cerebral ATP levels, absolute levels of lactate and citric acid cycle intermediates, and 13C-enrichment. However, DHCA induced significant abnormalities in glutamate cycling resulting in reduced glutamate/glutamine and elevated γ-aminobutyric acid (GABA)/glutamate along with neuroapoptosis (TUNEL), which were all prevented by SCP. Conclusions: DHCA alone induces abnormalities in cycling of the major neurotransmitters in association with neuroapoptosis, but does not alter cerebral glucose utilization during reperfusion. The data suggest that SCP prevents these modifications in glutamate/glutamine/GABA cycling and protects the cerebral cortex from neuroapoptosis.« less

Reduced levels of skeletal muscle Na+K+ -ATPase in McArdle disease

NASA Technical Reports Server (NTRS)

Haller, R. G.; Clausen, T.; Vissing, J.; Blomqvist, C. G. (Principal Investigator)

1998-01-01

We evaluated the hypothesis that impaired sarcolemmal function associated with exaggerated potassium release, impaired potassium uptake, or both may contribute to exertional fatigue and abnormal circulatory responses to exercise in McArdle disease (MD). The cellular mechanism of exertional fatigue and muscle injury in MD is unknown but likely involves impaired function of the ATPases that couple ATP hydrolysis to cellular work, including the muscle sodium potassium pump (Na+K+-ATPase). However, the concentration of muscle Na+K+ pumps in MD is not known, and no studies have related exercise increases in blood potassium concentrations to muscle Na+K+ pump levels. We measured muscle Na+K+ pumps (3H-ouabain binding) and plasma K+ in response to 20 minutes of cycle exercise in six patients with MD and in six sex-, age-, and weight-matched sedentary individuals. MD patients had lower levels of 3H-ouabain binding (231 +/- 18 pmol/g w.w., mean +/- SD, range, 210 to 251) than control subjects (317 +/- 37, range, 266 to 371, p < 0.0004), higher peak increases in plasma potassium in response to 45 +/- 7 W cycle exercise (MD, 1.00 +/- 0.15 mmol/L; control subjects, 0.48 +/- 0.09; p < 0.0001), and mean exercise heart rate responses to exercise that were 45 +/- 12 bpm greater than control subjects. Our results indicate that Na+K+ pump levels are low in MD patients compared with healthy subjects and identify a limitation of potassium reuptake that could result in sarcolemmal failure during peak rates of membrane activation and may promote exaggerated potassium-activated circulatory responses to submaximal exercise. The mechanism of the low Na+K+ pump concentrations in MD is unknown but may relate to deconditioning or to disruption of a close functional relationship between membrane ion transport and glycolysis.

Propofol-induced increase in vascular capacitance is due to inhibition of sympathetic vasoconstrictive activity.

PubMed

Hoka, S; Yamaura, K; Takenaka, T; Takahashi, S

1998-12-01

Venodilation is thought to be one of the mechanisms underlying propofol-induced hypotension. The purpose of this study is to test two hypotheses: (1) propofol increases systemic vascular capacitance, and (2) the capacitance change produced by propofol is a result of an inhibition of sympathetic vasoconstrictor activity. In 33 Wistar rats previously anesthetized with urethane and ketamine, vascular capacitance was examined before and after propofol infusion by measuring mean circulatory filling pressure (Pmcf). The Pmcf was measured during a brief period of circulatory arrest produced by inflating an indwelling balloon in the right atrium. Rats were assigned into four groups: an intact group, a sympathetic nervous system (SNS)-block group produced by hexamethonium infusion, a SNS-block + noradrenaline (NA) group, and a hypovolemic group. The Pmcf was measured at a control state and 2 min after a bolus administration of 2, 10, and 20 mg/kg of propofol. The mean arterial pressure (MAP) was decreased by propofol dose-dependently in intact, hypovolemic, and SNS-block groups, but the decrease in MAP was less in the SNS-block group (-25%) than in the intact (-50%) and hypovolemic (-61%) groups. In the SNS-block + NA group, MAP decreased only at 20 mg/kg of propofol (-18%). The Pmcf decreased in intact and hypovolemic groups in a dose-dependent fashion but was unchanged in the SNS-block and SNS-block + NA groups. The results have provided two principal findings: (1) propofol decreases Pmcf dose-dependently, and (2) the decrease in Pmcf by propofol is elicited only when the sympathetic nervous system is intact, suggesting that propofol increases systemic vascular capacitance as a result of an inhibition of sympathetic nervous system.

INTRACORPOREAL HEAT DISSIPATION FROM A RADIOISOTOPE-POWERED ARTIFICIAL HEART.

PubMed

Huffman, Fred N.; Hagen, Kenneth G.; Whalen, Robert L.; Fuqua, John M.; Norman, John C.

1974-01-01

The feasibility of radioisotope-fueled circulatory support systems depends on the ability of the body to dissipate the reject heat from the power source driving the blood pump as well as to tolerate chronic intracorporeal radiation. Our studies have focused on the use of the circulating blood as a heat sink. Initial in vivo heat transfer studies utilized straight tube heat exchangers (electrically and radioisotope energized) to replace a segment of the descending aorta. More recent studies have used a left ventricular assist pump as a blood-cooled heat exchanger. This approach minimizes trauma, does not increase the area of prosthetic interface with the blood, and minimizes system volume. Heat rejected from the thermal engine (vapor or gas cycle) is transported from the nuclear power source in the abdomen to the pump in the thoracic cavity via hydraulic lines. Adjacent tissue is protected from the fuel capsule temperature (900 to 1200 degrees F) by vacuum foil insulation and polyurethane foam. The in vivo thermal management problems have been studied using a simulated thermal system (STS) which approximates the heat rejection and thermal transport mechanisms of the nuclear circulatory support systems under development by NHLI. Electric heaters simulate the reject heat from the thermal engines. These studies have been essential in establishing the location, suspension, surgical procedures, and postoperative care for implanting prototype nuclear heart assist systems in calves. The pump has a thermal impedance of 0.12 degrees C/watt. Analysis of the STS data in terms of an electrical analog model implies a heat transfer coefficient of 4.7 x 10(-3) watt/cm(2) degrees C in the abdomen compared to a value of 14.9 x 10(-3) watt/cm(2) degrees C from the heat exchanger plenum into the diaphragm.

Operational Characteristics of Two Commercially Available Personal Cooling Vests

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Webbon, Bruce W.; Luna, Bernadette (Technical Monitor)

1996-01-01

Personal thermoregulatory systems which provide chest cooling are used in the industrial and aerospace environments to alleviate thermal stress. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to compare the effectiveness of two passive cooling vests, and to measure the body temperature and circulatory changes produced by each cooling vest configuration. A Life Enhancement Technologies, (LET) ice vest garment and a Steele, Inc. vest were used to cool the chest region of 11 male subjects (25 to 55 yr) in this study. Calf, forearm and finger blood flows were measured using a tetrapolar impedance rheograph. The subjects, seated in an upright position at normal room temperature (approximately 21 C) were tested for 60 min. with the cooling system operating at its maximum cooling capacity. Blood flows were recorded continuously using a computer data acquisition system with a sampling frequency of 250 Hz. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; respiration; and an activity index were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. No significant differences were found in either the oral or ear temperature responses to the two vests. However, the rectal and mean skin temperatures at the end of the cooling period were both significantly lower (P less than 0.05), approximately 0.2 and 1.9 C, respectively for the LET vest than for the Steele garment. These data show that different vest configurations may produce different thermal responses in healthy male subjects which should be considered in the use of these cooling garments.

Bodily systems and the spatial-functional structure of the human body.

PubMed

Smith, Barry; Munn, Katherine; Papakin, Igor

2004-01-01

The human body is a system made of systems. The body is divided into bodily systems proper, such as the endocrine and circulatory systems, which are subdivided into many sub-systems at a variety of levels, whereby all systems and subsystems engage in massive causal interaction with each other and with their surrounding environments. Here we offer an explicit definition of bodily system and provide a framework for understanding their causal interactions. Medical sciences provide at best informal accounts of basic notions such as system, process, and function, and while such informality is acceptable in documentation created for human beings, it falls short of what is needed for computer representations. In our analysis we will accordingly provide the framework for a formal definition of bodily system and of associated notions.

Development of a space activity suit

NASA Technical Reports Server (NTRS)

Annis, J. F.; Webb, P.

1971-01-01

The development of a series of prototype space activity suit (SAS) assemblies is discussed. The SAS is a new type of pressure suit designed especially for extravehicular activity. It consists of a set of carefully tailored elastic fabric garments which have been engineered to supply sufficient counterpressure to the body to permit subjects to breath O2 at pressures up to 200 mm Hg without circulatory difficulty. A closed, positive pressure breathing system (PPBS) and a full bubble helmet were also developed to complete the system. The ultimate goal of the SAS is to improve the range of activity and decrease the energy cost of work associated with wearing conventional gas filled pressure suits. Results are presented from both laboratory (1 atmosphere) and altitude chamber tests with subjects wearing various SAS assemblies. In laboratory tests lasting up to three hours, the SAS was worn while subjects breathed O2 at pressures up to 170 mm Hg without developing physiological problems. The only physiological symptoms apparent were a moderate tachycardia related to breathing pressures above 130 mm Hg, and a small collection of edema fluid in the hands. Both problems were considered to be related to areas of under-pressurization by the garments. These problems, it is suggested, can ultimately be corrected by the development of new elastic fabrics and tailoring techniques. Energy cost of activity, and mobility and dexterity of subjects in the SAS, were found to be superior to those in comparable tests on subjects in full pressure suits.

Determinants of the Delegation of Health Care Aboard Ships with Women Assigned

DTIC Science & Technology

1989-06-07

Classification of Diseases (ICD-9) code7 by one of five research staff memners. 4 RESULTS Of the original 2,906 patient visits, the research staff was tnable...was recomputed: (1) neoplasms, (2) endocrine, nutritional and metabolic diseases , and immunity disorders, (3) diseases of the blood and blood-forming...organs, (4) diseases of the circulatory system, (5) complications o pregnancy, and (6) congenital anomalies. As shown in Figure 2, the results of this

Cardiovascular Imaging and Image Processing: Theory and Practice - 1975

NASA Technical Reports Server (NTRS)

Harrison, Donald C. (Editor); Sandler, Harold (Editor); Miller, Harry A. (Editor); Hood, Manley J. (Editor); Purser, Paul E. (Editor); Schmidt, Gene (Editor)

1975-01-01

Ultrasonography was examined in regard to the developmental highlights and present applicatons of cardiac ultrasound. Doppler ultrasonic techniques and the technology of miniature acoustic element arrays were reported. X-ray angiography was discussed with special considerations on quantitative three dimensional dynamic imaging of structure and function of the cardiopulmonary and circulatory systems in all regions of the body. Nuclear cardiography and scintigraphy, three--dimensional imaging of the myocardium with isotopes, and the commercialization of the echocardioscope were studied.

Orthostasis test in the practice of the cardiologist

NASA Technical Reports Server (NTRS)

Moskalenko, N. P.; Glezer, M. G.

1980-01-01

The orthostasis test makes it possible to evaluate neurohumoral regulation and reaction of the circulatory system and to detect changes in the function of a number of internal organs (especially the kidney). Simultaneous recording of the ECG in an orthostatic position despite nonspecificity, makes it possible to detect hidden damage (organic or metabolic) or increased sensitivity of the myocardium to stressor sympathetico-adrenal effects, stability of therapeutic effect, and the action mechanism of a number of drugs.

The Impact of Pharmaceutical Expenses and the Use of Flexible Budgets at The Johns Hopkins Hospital

DTIC Science & Technology

1999-12-01

Newborns & Other Neonates, “Blood, Blood Forming Organs, & Immulogical”, Myeloproliferative Diseases & Poorly Diff Neoplasm , Infectious & Parasitic Diseases...1,716.1) Endocrine, Nutritional, & Metabolic (n=412) 3.2 2.2 38 268 (1,807.7) 81.4 2,140 (5,366.3) Myeloproliferative Diseases & Poorly Diff Neoplasm (n...pharmaceutical expenditures were for drugs utilized in six of the twenty-five MDG’s, Myeloproliferative Diseases at 18.5%, Circulatory System at 14.7

In Vitro Study of Flow Regulation for Pulmonary Insufficiency

PubMed Central

Camp, T. A.; Stewart, K. C.; Figliola, R. S.; McQuinn, T.

2007-01-01

Given the tolerance of the right heart circulation to mild regurgitation and gradient, we study the potential of using motionless devices to regulate the pulmonary circulation. In addition, we document the flow performance of two mechanical valves. A motionless diode, a nozzle, a mechanical bileaflet valve, and a tilting disk valve were tested in a pulmonary mock circulatory system over the normal human range of pulmonary vascular resistance (PVR). For the mechanical valves, regurgitant fractions (RFs) and transvalvular pressure gradients were found to be weak functions of PVR. On the low end of normal PVR, the bileaflet and tilting disk valves fluttered and would not fully close. Despite this anomaly, the regurgitant fraction of either valve did not change significantly. The values for RF and transvalvular gradient measured varied from 4 to 7% and 4 to 7 mm Hg, respectively, at 5 lpm for all tests. The diode valve was able to regulate flow with mild regurgitant fraction and trivial gradient but with values higher than either mechanical valve tested. Regurgitant fraction ranged from 2 to 17% in tests extending from PVR values of 1 to 4.5 mm Hg/lpm at 5 lpm and with concomitant increases in gradient up to 17 mm Hg. The regurgitant fraction for the nozzle increased from 2 to 23% over the range of PVR with gradients increasing to 18 mm Hg. The significant findings were: (1) the mechanical valves controlled regurgitation at normal physiological cardiac output and PVR even though they failed to close at some normal values of PVR and showed leaflet flutter; and (2) it may be possible to regulate the pulmonary circulation to tolerable levels using a motionless pulmonary valve device. PMID:17408334

Influence of using challenging tasks in biology classrooms on students' cognitive knowledge structure: an empirical video study

NASA Astrophysics Data System (ADS)

Nawani, Jigna; Rixius, Julia; Neuhaus, Birgit J.

2016-08-01

Empirical analysis of secondary biology classrooms revealed that, on average, 68% of teaching time in Germany revolved around processing tasks. Quality of instruction can thus be assessed by analyzing the quality of tasks used in classroom discourse. This quasi-experimental study analyzed how teachers used tasks in 38 videotaped biology lessons pertaining to the topic 'blood and circulatory system'. Two fundamental characteristics used to analyze tasks include: (1) required cognitive level of processing (e.g. low level information processing: repetiition, summary, define, classify and high level information processing: interpret-analyze data, formulate hypothesis, etc.) and (2) complexity of task content (e.g. if tasks require use of factual, linking or concept level content). Additionally, students' cognitive knowledge structure about the topic 'blood and circulatory system' was measured using student-drawn concept maps (N = 970 students). Finally, linear multilevel models were created with high-level cognitive processing tasks and higher content complexity tasks as class-level predictors and students' prior knowledge, students' interest in biology, and students' interest in biology activities as control covariates. Results showed a positive influence of high-level cognitive processing tasks (β = 0.07; p < .01) on students' cognitive knowledge structure. However, there was no observed effect of higher content complexity tasks on students' cognitive knowledge structure. Presented findings encourage the use of high-level cognitive processing tasks in biology instruction.

Flow interactions with cells and tissues: cardiovascular flows and fluid-structure interactions. Sixth International Bio-Fluid Mechanics Symposium and Workshop, March 28-30, 2008, Pasadena, California.

PubMed

Friedman, Morton H; Krams, Rob; Chandran, Krishnan B

2010-03-01

Interactions between flow and biological cells and tissues are intrinsic to the circulatory, respiratory, digestive and genitourinary systems. In the circulatory system, an understanding of the complex interaction between the arterial wall (a living multi-component organ with anisotropic, nonlinear material properties) and blood (a shear-thinning fluid with 45% by volume consisting of red blood cells, platelets, and white blood cells) is vital to our understanding of the physiology of the human circulation and the etiology and development of arterial diseases, and to the design and development of prosthetic implants and tissue-engineered substitutes. Similarly, an understanding of the complex dynamics of flow past native human heart valves and the effect of that flow on the valvular tissue is necessary to elucidate the etiology of valvular diseases and in the design and development of valve replacements. In this paper we address the influence of biomechanical factors on the arterial circulation. The first part presents our current understanding of the impact of blood flow on the arterial wall at the cellular level and the relationship between flow-induced stresses and the etiology of atherosclerosis. The second part describes recent advances in the application of fluid-structure interaction analysis to arterial flows and the dynamics of heart valves.

Chronic Deep Brain Stimulation of the Hypothalamic Nucleus in Wistar Rats Alters Circulatory Levels of Corticosterone and Proinflammatory Cytokines

PubMed Central

Calleja-Castillo, Juan Manuel; De La Cruz-Aguilera, Dora Luz; Manjarrez, Joaquín; Velasco-Velázquez, Marco Antonio; Morales-Espinoza, Gabriel; Moreno-Aguilar, Julia; Hernández, Maria Eugenia; Aguirre-Cruz, Lucinda

2013-01-01

Deep brain stimulation (DBS) is a therapeutic option for several diseases, but its effects on HPA axis activity and systemic inflammation are unknown. This study aimed to detect circulatory variations of corticosterone and cytokines levels in Wistar rats, after 21 days of DBS-at the ventrolateral part of the ventromedial hypothalamic nucleus (VMHvl), unilateral cervical vagotomy (UCVgX), or UCVgX plus DBS. We included the respective control (C) and sham (S) groups (n = 6 rats per group). DBS treated rats had higher levels of TNF-α (120%; P < 0.01) and IFN-γ (305%; P < 0.001) but lower corticosterone concentration (48%; P < 0.001) than C and S. UCVgX animals showed increased corticosterone levels (154%; P < 0.001) versus C and S. UCVgX plus DBS increased IL-1β (402%; P < 0.001), IL-6 (160%; P < 0.001), and corsticosterone (178%; P < 0.001 versus 48%; P < 0.001) compared with the C and S groups. Chronic DBS at VMHvl induced a systemic inflammatory response accompanied by a decrease of HPA axis function. UCVgX rats experienced HPA axis hyperactivity as result of vagus nerve injury; however, DBS was unable to block the HPA axis hyperactivity induced by unilateral cervical vagotomy. Further studies are necessary to explore these findings and their clinical implication. PMID:24235973

The effect of age on fluid intelligence is fully mediated by physical health.

PubMed

Bergman, Ingvar; Almkvist, Ove

2013-01-01

The present study investigated the extent to which the effect of age on cognitive ability is predicted by individual differences in physical health. The sample consisted of 118 volunteer subjects who were healthy and ranging in age from 26 to 91. The examinations included a clinical investigation, magnetic resonance imaging (MRI) brain neuroimaging, and a comprehensive neuropsychological assessment. The effect of age on fluid IQ with and without visual spatial praxis and on crystallized IQ was tested whether being fully-, partially- or non-mediated by physical health. Structural equation analyses showed that the best and most parsimonious fit to the data was provided by models that were fully mediated for fluid IQ without praxis, non-mediated for crystallized IQ and partially mediated for fluid IQ with praxis. The diseases of the circulatory and nervous systems were the major mediators. It was concluded from the pattern of findings that the effect of age on fluid intelligence is fully mediated by physical health, while crystallized intelligence is non-mediated and visual spatial praxis is partially mediated, influenced mainly by direct effects of age. Our findings imply that improving health by acting against the common age-related circulatory- and nervous system diseases and risk factors will oppose the decline in fluid intelligence with age. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

[The action of high-molecular linear polymers on the circulatory system].

PubMed

Grigorian, S S; Sokolova, I A; Shakhnazarov, A A

1995-01-01

An analysis of the hemodynamic consequences of the injections of long linear polymers with high molecular weight is introduced. These injections lead to an increase of the cardiac output, to a decrease of the blood pressure, and hence cause a reduction of the resistance to blood flow. It follows that such kind of polymers is able to normalize hemodynamics under some pathophysiological conditions, e.g., during experimental atherosclerosis, ischemic state, hemorrhagic shock. An addition of drag-reducing polymers into the blood system is associated with a modification of the blood flow microstructure itself.

Effect of three day bed-rest on circulatory and hormonal responses to active orthostatic test in endurance trained athletes and untrained subjects

NASA Technical Reports Server (NTRS)

Kubala, P.; Smorawinski, J.; Kaciuba-Uscilko, H.; Nazar, K.; Bicz, B.; Greenleaf, J. E.

1996-01-01

Circulatory and hormonal parameters were measured in endurance-trained athletes and control subjects during orthostatic tolerance tests conducted prior to and after three days of bed rest. Heart rate and blood pressure changes due to bed rest appeared to be the same in both groups. Hormonal changes, however, were different between the two groups, with the athletes having decreased sympathoadrenal activity and increased plasma renin activity. Untrained subjects had changes in cortisol secretion only.

A comparison between minimized extracorporeal circuits and conventional extracorporeal circuits in patients undergoing aortic valve surgery: is 'minimally invasive extracorporeal circulation' just low prime or closed loop perfusion ?

PubMed

Starinieri, Pascal; Declercq, Peter E; Robic, Boris; Yilmaz, Alaaddin; Van Tornout, Michiel; Dubois, Jasperina; Mees, Urbain; Hendrikx, Marc

2017-07-01

Even though results have been encouraging, an unequivocal conclusion on the beneficial effect of minimally invasive extracorporeal circulation (MiECC) in patients undergoing aortic valve surgery cannot be derived from previous publications. Long-term outcomes are rarely reported and a significant decrease in operative mortality has not been shown. Most studies have a limited number of patients and are underpowered. They merely report on short-term results of a heterogeneous intraoperative group using different types of ECC system in aortic valve surgery. The aim of the present study was to determine whether MiECC systems are more beneficial than conventional extracorporeal systems (CECC) with regard to mortality, hospital stay and inflammation and with only haemodilution and blood-air interface as differences. We retrospectively analysed data regarding mortality, hospital stay and inflammation in patients undergoing isolated aortic valve surgery. Forty patients were divided into two groups based on the type of extracorporeal system used; conventional (n=20) or MiECC (n=20). Perioperative blood product requirements were significantly lower in the MiECC group (MiECC: 0.2±0.5 units vs CECC: 0.9±1.2 units, p=0.004). No differences were seen postoperatively regarding mortality (5% vs 5%, p=0.99), total length of hospital stay (10.6±7.2 days (MiECC) vs 12.1±5.9 days (CECC), p=0.39) or inflammation markers (CRP: MiECC: 7.09±13.62 mg/L vs CECC: 3.4±3.2 mg/L, p=0.89). MiECC provides circulatory support that is equally safe and feasible as conventional extracorporeal circuits. No differences in mortality, hospital stay or inflammation markers were observed.

Biplane roentgen videometric system for dynamic, 60/sec, studies of the shape and size of circulatory structures, particularly the left ventricle.

NASA Technical Reports Server (NTRS)

Ritman, E. L.; Sturm, R. E.; Wood, E. H.

1973-01-01

An operator interactive video system for the measurement of roentgen angiographically outlined structures is described. Left ventricular volume and three-dimensional shapes are calculated from up to 200 pairs of diameters measured from ventriculograms at the rate of 60 pairs of biplane images per second. The accuracy and reproducibility of volumes calculated by the system were established by analysis of roentgenograms of inanimate objects of known volume and by comparison of left ventricular stroke volumes calculated by the system with the stroke volumes calculated by an indicator-dilution technique and an aortic root electromagnetic flowmeter. Computer-generated display of the large amounts of data obtained by the videometry system is described.

Deep Hypothermic Circulatory Arrest vs. Antegrade Cerebral Perfusion in Cerebral Protection during the Surgical Treatment of Chronic Dissection of the Ascending and Arch Aorta

PubMed Central

Kamenskaya, Oksana Vasilyevna; Klinkova, Asya Stanislavovna; Chernyavsky, Alexander Mikhailovich; Lomivorotov, Vladimir Vladimirovich; Meshkov, Ivan Olegovich; Karaskov, Alexander Mikhailovich

2017-01-01

Abstract: Circulatory arrest during aortic surgery presents a risk of neurological complications. The present study aimed to investigate the effectiveness of deep hypothermic circulatory arrest (DHCA) vs. antegrade cerebral perfusion (ACP) in cerebral protection during the surgical treatment of chronic dissection of the ascending and arch aorta and to assess the quality-of-life (QoL) in the long-term postoperative period with respect to the used cerebral protection method. In a prospective, randomized study, 58 patients with chronic type I aortic dissection who underwent ascending aorta and aortic arch replacement surgery were included. Patients were allocated in two groups: 29 patients who underwent surgery under moderate hypothermia (24°C) combined with ACP and 29 patients who underwent surgery under DHCA (18°C) with craniocerebral hypothermia. The regional hemoglobin oxygen saturation (rSO2, %) were compared during surgery, neurological complications were analyzed during the early postoperative period, QoL was compared in the long-term postoperative period (1-year follow-up). During the early postoperative period, 37.9% of patients in the DHCA group exhibited neurological complications, compared with 13.8% of those in the ACP group (p < .05). The risk of neurological complications in the early postoperative period was dependent on the extent of rSO2 decrease during circulatory arrest. In the ACP group, rSO2 decreased by ≤17% from baseline during circulatory arrest. In the DHCA group, a more profound decrease in rSO2 (>30%) was recorded (p < .05). QoL in the long-term period after surgery improved, but it was not dependent on the cerebral protection method used during surgery. ACP during aortic replacement demonstrated the most advanced properties of cerebral protection that can be evidenced by a lesser degree of neurological complications, compared with patients who underwent surgery under conditions of DHCA. QoL after surgery was not dependent on the cerebral protection method used during surgery. PMID:28298661

Antithrombin III is associated with acute liver failure in patients with end-stage heart failure undergoing mechanical circulatory support.

PubMed

Hoefer, Judith; Ulmer, Hanno; Kilo, Juliane; Margreiter, Raimund; Grimm, Michael; Mair, Peter; Ruttmann, Elfriede

2017-06-01

There are few data on the role of liver dysfunction in patients with end-stage heart failure supported by mechanical circulatory support. The aim of our study was to investigate predictors for acute liver failure in patients with end-stage heart failure undergoing mechanical circulatory support. A consecutive 164 patients with heart failure with New York Heart Association class IV undergoing mechanical circulatory support were investigated for acute liver failure using the King's College criteria. Clinical characteristics of heart failure together with hemodynamic and laboratory values were analyzed by logistic regression. A total of 45 patients (27.4%) with heart failure developed subsequent acute liver failure with a hospital mortality of 88.9%. Duration of heart failure, cause, cardiopulmonary resuscitation, use of vasopressors, central venous pressure, pulmonary capillary wedge pressure, pulmonary pulsatility index, cardiac index, and transaminases were not significantly associated with acute liver failure. Repeated decompensation, atrial fibrillation (P < .001) and the use of inotropes (P = .007), mean arterial (P = .005) and pulmonary pressures (P = .042), cholinesterase, international normalized ratio, bilirubin, lactate, and pH (P < .001) were predictive of acute liver failure in univariate analysis only. In multivariable analysis, decreased antithrombin III was the strongest single measurement indicating acute liver failure (relative risk per %, 0.84; 95% confidence interval, 0.77-0.93; P = .001) and remained an independent predictor when adjustment for the Model for End-Stage Liver Disease score was performed (relative risk per %, 0.89; 95% confidence interval, 0.80-0.99; P = .031). Antithrombin III less than 59.5% was identified as a cutoff value to predict acute liver failure with a corresponding sensitivity of 81% and specificity of 87%. In addition to the Model for End-Stage Liver Disease score, decreased antithrombin III activity tends to be superior in predicting acute liver failure compared with traditionally thought predictors. Antithrombin III measurement may help to identify patients more precisely who are developing acute liver failure during mechanical circulatory support. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Impact of dynamic changes of elevated bilirubin on survival in patients on veno-arterial extracorporeal life support for acute circulatory failure.

PubMed

Freundt, Miriam; Lunz, Dirk; Philipp, Alois; Panholzer, Bernd; Lubnow, Matthias; Friedrich, Christine; Rupprecht, Leopold; Hirt, Stephan; Haneya, Assad

2017-01-01

Veno-arterial extracorporeal life support (ECLS) is an established method to stabilize acute circulatory failure. Parameters and data on when to ideally wean circulatory support are limited. Bilirubin is a marker of end-organ damage. Therefore, the purpose of this large study was to evaluate the impact of dynamic changes of elevated bilirubin levels on survival in patients on ECLS. We reviewed 502 consecutive cases of ECLS from 2007 to 2015. Bilirubin levels were recorded before implantation and until six days after explantation. Dynamic bilirubin changes, and hemodynamic and laboratory outcome parameters were compared in survivors and nonsurvivors. Reason for ECLS implantation was cardiac arrest with ongoing resuscitation in 230 (45.8%), low cardiac output in 174 (34.7%) and inability to wean off cardiopulmonary bypass in 98 (19.5%) patients. 307 (61.2%) patients were weaned off ECLS, however, 206 (41.0%) survived. Mean duration of ECLS was 3 (2-6) days, and survivors received significantly longer ECLS (5 vs 3 days, p < 0.001). Survivors had significantly lower baseline bilirubin levels (p = 0.003). Bilirubin started to rise from day 2 in all patients. In survivors, bilirubin levels had trended down on the day of ECLS explantation and stayed at an acceptable level. However, in weaned patients who did not survive and patients who died on ECLS bilirubin levels continued to rise during the recorded period. ECLS support improves survival in patients with acute circulatory failure. Down trending bilirubin levels on veno-arterial ECLS indicate improved chances of successful weaning and survival in hemodynamically stable patients.

Circadian variation in the circulatory responses to exercise: relevance to the morning peaks in strokes and cardiac events

PubMed Central

2009-01-01

Sudden cardiac and cerebral events are most common in the morning. A fundamental question is whether these events are triggered by the increase in physical activity after waking, and/or a result of circadian variation in the responses of circulatory function to exercise. Although signaling pathways from the master circadian clock in the suprachiasmatic nuclei to sites of circulatory control are not yet understood, it is known that cerebral blood flow, autoregulation and cerebrovascular reactivity to changes in CO2 are impaired in the morning and, therefore, could explain the increased risk of cerebrovascular events. Blood pressure (BP) and the rate pressure product (RPP) show marked ‘morning surges’ when people are studied in free-living conditions, making the rupture of a fragile atherosclerotic plaque and sudden cardiac event more likely. Since cerebral autoregulation is reduced in the morning, this surge in BP may also exacerbate the risk of hemorrhagic and ischemic strokes in the presence of other acute and chronic risk factors. Increased sympathetic activity, decreased endothelial function, and increased platelet aggregability could also be important in explaining the morning peak in cardiac and cerebral events but how these factors respond to exercise at different times of day is unclear. Evidence is emerging that the exercise-related responses of BP and RPP are increased in the morning when prior sleep is controlled. We recommend that such ‘semi-constant routine’ protocols are employed to examine the relative influence of the body clock and exogenous factors on the 24-h variation in other circulatory factors. PMID:19826832

Vasoactive mediators and splanchnic perfusion.

PubMed

Reilly, P M; Bulkley, G B

1993-02-01

To provide an overview of the splanchnic hemodynamic response to circulatory shock. Previous studies performed in our own laboratory, as well as a computer-assisted search of the English language literature (MEDLINE, 1966 to 1991), followed by a selective review of pertinent articles. Studies were selected that demonstrated relevance to the splanchnic hemodynamic response to circulatory shock, either by investigating the pathophysiology or documenting the sequelae. Article selection included clinical studies as well as studies in appropriate animal models. Pertinent data were abstracted from the cited articles. The splanchnic hemodynamic response to circulatory shock is characterized by a selective vasoconstriction of the mesenteric vasculature mediated largely by the renin-angiotensin axis. This vasospasm, while providing a natural selective advantage to the organism in mild-to-moderate shock (preserving relative perfusion of the heart, kidneys, and brain), may, in more severe shock, cause consequent loss of the gut epithelial barrier, or even hemorrhagic gastritis, ischemic colitis, or ischemic hepatitis. From a physiologic standpoint, nonpulsatile cardiopulmonary bypass, a controlled form of circulatory shock, has been found experimentally to significantly increase circulating levels of angiotensin II, the hormone responsible for this selective splanchnic vasoconstriction. While angiotensin II has been viewed primarily as the mediator responsible for the increased total vascular resistance seen during (and after) cardiopulmonary bypass, it may also cause the disproportionate decrease in mesenteric perfusion, as measured in human subjects by intraluminal gastric tonometry and galactose clearance by the liver, as well as the consequent development of the multiple organ failure syndrome seen in 1% to 5% of patients after cardiac surgery.

Fatty Acid-Mediated Inhibition of Metal Binding to the Multi-Metal Site on Serum Albumin: Implications for Cardiovascular Disease.

PubMed

Blindauer, Claudia A; Khazaipoul, Siavash; Yu, Ruitao; Stewart, Alan J

2016-01-01

Human serum albumin (HSA) is the major protein in blood plasma and is responsible for circulatory transport of a range of small molecules including fatty acids, metal ions and drugs. We previously identified the major plasma Zn2+ transport site on HSA and revealed that fatty-acid binding (at a distinct site called the FA2 site) and Zn2+ binding are interdependent via an allosteric mechanism. Since binding affinities of long-chain fatty acids exceed those of plasma Zn2+, this means that under certain circumstances the binding of fatty acid molecules to HSA is likely to diminish HSA Zn2+-binding, and hence affects the control of circulatory and cellular Zn2+ dynamics. This relationship between circulatory fatty acid and Zn2+ dynamics is likely to have important physiological and pathological implications, especially since it has been recognised that Zn2+ acts as a signalling agent in many cell types. Fatty acid levels in the blood are dynamic, but most importantly, chronic elevation of plasma fatty acid levels is associated with some metabolic disorders and disease states - including myocardial infarction and other cardiovascular diseases. In this article, we briefly review the metal-binding properties of albumin and highlight the importance of their interplay with fatty acid binding. We also consider the impact of this dynamic link upon levels and speciation of plasma Zn2+, its effect upon cellular Zn2+ homeostasis and its relevance to cardiovascular and circulatory processes in health and disease.

Revealing a new mode of sensitization induced by mechanical circulatory support devices: Impact of anti-AT1 R antibodies.

PubMed

Zhang, Xiaohai; Mirocha, James; Aintablian, Tamar; Dimbil, Sadia; Moriguchi, Jaime; Arabia, Francisco; Kobashigawa, Jon A; Reinsmoen, Nancy

2018-02-01

Increased levels of angiotensin II type 1 receptor (AT 1 R) antibody have been shown to be associated with allograft rejection. This study aims to determine the rate of development of antibody to AT 1 R after mechanical circulatory support device (MCS) implantation, and if the development of strong binding AT 1 R antibodies is associated with survival. Eighty-eight patients who had one MCS implantation were accessed based on serum availability. Mechanical circulatory support devices in this cohort included pneumatic bilateral paracorporeal ventricular assist device, continuous flow left ventricular assist device, and total artificial heart. Of 88 patients, seven patients had AT 1 R antibodies ≥40 U/mL preimplantation. For 81 patients who had AT 1 R antibodies <40 U/mL, the median value was 8 U/mL. Of these 81 patients, AT 1 R antibody levels in 55 (68%) patients reached the saturated concentration (≥40 U/mL) postimplantation (P < .0001), with the highest percentage of patients with the saturated level of AT 1 R antibody observed in the pneumatic bilateral paracorporeal ventricular assist device group. Compared to patients without the saturated level of AT 1 R antibodies, patients with the saturated AT 1 R antibody level had lower 18-month survival (P = .040). Mechanical circulatory support devices implantation significantly increases AT 1 R antibody levels. The saturated level of AT 1 R antibodies is associated with lower patient survival postimplantation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sensitivity Analysis of Median Lifetime on Radiation Risks Estimates for Cancer and Circulatory Disease amongst Never-Smokers

NASA Technical Reports Server (NTRS)

Chappell, Lori J.; Cucinotta, Francis A.

2011-01-01

Radiation risks are estimated in a competing risk formalism where age or time after exposure estimates of increased risks for cancer and circulatory diseases are folded with a probability to survive to a given age. The survival function, also called the life-table, changes with calendar year, gender, smoking status and other demographic variables. An outstanding problem in risk estimation is the method of risk transfer between exposed populations and a second population where risks are to be estimated. Approaches used to transfer risks are based on: 1) Multiplicative risk transfer models -proportional to background disease rates. 2) Additive risk transfer model -risks independent of background rates. In addition, a Mixture model is often considered where the multiplicative and additive transfer assumptions are given weighted contributions. We studied the influence of the survival probability on the risk of exposure induced cancer and circulatory disease morbidity and mortality in the Multiplicative transfer model and the Mixture model. Risks for never-smokers (NS) compared to the average U.S. population are estimated to be reduced between 30% and 60% dependent on model assumptions. Lung cancer is the major contributor to the reduction for NS, with additional contributions from circulatory diseases and cancers of the stomach, liver, bladder, oral cavity, esophagus, colon, a portion of the solid cancer remainder, and leukemia. Greater improvements in risk estimates for NS s are possible, and would be dependent on improved understanding of risk transfer models, and elucidating the role of space radiation on the various stages of disease formation (e.g. initiation, promotion, and progression).

Donation After Circulatory Death for Liver Transplantation: A Meta-Analysis on the Location of Life Support Withdrawal Affecting Outcomes.

PubMed

Cao, Yiming; Shahrestani, Sara; Chew, Hong Chee; Crawford, Michael; Macdonald, Peter Simon; Laurence, Jerome; Hawthorne, Wayne John; Dhital, Kumud; Pleass, Henry

2016-07-01

Liver transplantation using donation after circulatory death (DCD) donors is associated with inferior outcomes compared to donation after brain death (DBD). Prolonged donor warm ischemic time has been identified as the key factor responsible for this difference. Various aspects of the donor life support withdrawal procedure, including location of withdrawal and administration of antemortem heparin, are thought to play important roles in mitigating the effects of warm ischemia. However, a systematic exploration of these factors is important for more confident integration of these practices into a standard DCD protocol. Medline, EMBASE, and Cochrane libraries were systematically searched and 23 relevant studies identified for analysis. Donation after circulatory death recipients were stratified according to location of life support withdrawal (intensive care unit or operating theater) and use of antemortem heparin. Donation after circulatory death recipients had comparable 1-year patient survival to DBD recipients if the location of withdrawal of life support was the operating theater, but not if the location was the intensive care unit. Likewise, the inferior 1-year graft survival and higher incidence of ischemic cholangiopathy of DCD compared with DBD recipients were improved by withdrawal in operating theater, although higher rates of ischemic cholangiopathy and worse graft survival were still observed in DCD recipients. Furthermore, administering heparin before withdrawal of life support reduced the incidence of primary nonfunction of the allograft. Our evidence suggests that withdrawal in the operating theater and premortem heparin administration improve DCD liver transplant outcomes, thus allowing for the most effective usage of these valuable organs.

A systematic review and meta-analysis of the circulatory, erythrocellular and CSF selenium levels in Alzheimer's disease: A metal meta-analysis (AMMA study-I).

PubMed

Reddy, Varikasuvu Seshadri; Bukke, Suman; Dutt, Naveen; Rana, Puneet; Pandey, Arun Kumar

2017-07-01

Available studies in the literature on the selenium levels in Alzheimer's disease (AD) are inconsistent with some studies reporting its decrease in the circulation, while others reported an increase or no change as compared to controls. The objective of this study was to perform a meta-analysis of circulatory (plasma/serum and blood), erythrocyte and cerebrospinal fluid (CSF) selenium levels in AD compared controls. We also performed a meta-analysis of the correlation coefficients (r) to demonstrate the associations between selenium and glutathione peroxidase (GPx) in AD patients. All major databases were searched for eligible studies. We included 12 case-control/observational studies reporting selenium concentrations in AD and controls. Pooled-overall effect size as standardized mean difference (SMD) and pooled r-values were generated using Review Manager 5.3 and MedCalc 15.8 software. Random-effects meta-analysis indicated a decrease in circulatory (SMD=-0.44), erythrocellular (SMD=-0.52) and CSF (SMD=-0.14) selenium levels in AD patients compared to controls. Stratified meta-analysis demonstrated that the selenium levels were decreased in both the subgroups with (SMD=-0.55) and without (SMD=-0.37) age matching between AD and controls. Our results also demonstrated a direct association between decreased selenium levels and GPx in AD. This meta-analysis suggests that circulatory selenium concentration is significantly lower in AD patients compared to controls and this decrease in selenium is directly correlated with an important antioxidant enzyme, the GPx, in AD. Copyright © 2017 Elsevier GmbH. All rights reserved.

Protective effect of chitosan from Sepia kobiensis (Hoyle 1885) cuttlebone against CCl4 induced hepatic injury.

PubMed

Ramasamy, Pasiyappazham; Subhapradha, Namasivayam; Shanmugam, Vairamani; Shanmugam, Annaian

2014-04-01

Carbon tetrachloride (CCl4) is a potent hepatotoxic agent causing hepatic necrosis and it is widely used in animal models for induction of acute and chronic liver damage. The antioxidative and hepatoprotective effects of chitosan from Sepia kobiensis against CCl4 induced liver toxicity in Wistar rats was studied by measuring the activity of lipid peroxidation (TBARS, lipid hydroperoxides), non enzymatic antioxidant (GSH), antioxidant enzyme activities (SOD, CAT and GPx), liver marker enzymes (ALT and AST), lipid profile (FFA, TG, cholesterol and HDL cholesterol) and histopathological changes. Rats treated with chitosan against CCl4 toxicity showed significantly decreased levels of ALT and AST activities, total cholesterol, triglyceride and free fatty acid in plasma and tissue. Whereas the treatment with chitosan along with CCl4 showed markedly increased level of hepatic and circulatory in SOD, CAT, GPx and reduced glutathione and decreased the malondialdehyde level. Histopathological observations proved the marked hepatoprotective effect of chitosan. The CCl4 induced alterations in circulatory and hepatic antioxidant defense system were normalized by chitosan and it could be concluded that the hepatoprotective effect of chitosan may be due to its antioxidant and antilipidemic properties. Copyright © 2014 Elsevier B.V. All rights reserved.

CHANGES OF ARTERIAL BLOOD PRESSURE IN ACUTE RADIATION DISEASE

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

Ryzewski, J.

1962-12-01

Acute experiments were done in cats and chronic experiments in dogs. The cats were subjected to whole-body x irradiation with a dose of 1500 r, and were examined on the third day after irradiation, when radiation disease was fully developed. Reflexes from the baro- and chemoreceptors were investigated, and arterial blood pressure was recorded in the irradiated cats after intravenous administration of adrenaline, noradrenaline, serotonin, acetylcholine, histamine, Regitine, atropine, or Pendiomid. Dogs were subjected to whole-body irradiation with 800 r,; changes in arterial blood pressure, which occurred after the administration of neurohormones, were investigated before and after irradiation. Pressor reflexesmore » in irradiated cats, elicited by clamping and unclamping of both common carotid arteries, corresponded to a rise from 129.6 to 141.4 mm Hg, as compared to pressor reflexes in nonirradiated cats from 106.6 to 146. Reflexes from carotid sinus chemoreceptors evoked by 0.5% KCl were also weaker in irradiated cats. The results of both the acute and chronic experiments indicate that circulatory changes occur in radiation disease. The changes mainly involve responses of the circulatory system to neurohormones and stimulation of vascular baro- and chemoreceptors. (TCO)« less

How safe is safe enough? Radiation risk for a human mission to Mars.

PubMed

Cucinotta, Francis A; Kim, Myung-Hee Y; Chappell, Lori J; Huff, Janice L

2013-01-01

Astronauts on a mission to Mars would be exposed for up to 3 years to galactic cosmic rays (GCR)--made up of high-energy protons and high charge (Z) and energy (E) (HZE) nuclei. GCR exposure rate increases about three times as spacecraft venture out of Earth orbit into deep space where protection of the Earth's magnetosphere and solid body are lost. NASA's radiation standard limits astronaut exposures to a 3% risk of exposure induced death (REID) at the upper 95% confidence interval (CI) of the risk estimate. Fatal cancer risk has been considered the dominant risk for GCR, however recent epidemiological analysis of radiation risks for circulatory diseases allow for predictions of REID for circulatory diseases to be included with cancer risk predictions for space missions. Using NASA's models of risks and uncertainties, we predicted that central estimates for radiation induced mortality and morbidity could exceed 5% and 10% with upper 95% CI near 10% and 20%, respectively for a Mars mission. Additional risks to the central nervous system (CNS) and qualitative differences in the biological effects of GCR compared to terrestrial radiation may significantly increase these estimates, and will require new knowledge to evaluate.

Renal vascular responses to static handgrip: role of muscle mechanoreflex

NASA Technical Reports Server (NTRS)

Momen, Afsana; Leuenberger, Urs A.; Ray, Chester A.; Cha, Susan; Handly, Brian; Sinoway, Lawrence I.

2003-01-01

During exercise, the sympathetic nervous system is activated, which causes vasoconstriction. The autonomic mechanisms responsible for this vasoconstriction vary based on the particular tissue being studied. Attempts to examine reflex control of the human renal circulation have been difficult because of technical limitations. In this report, the Doppler technique was used to examine renal flow velocity during four muscle contraction paradigms in conscious humans. Flow velocity was divided by mean arterial blood pressure to yield an index of renal vascular resistance (RVR). Fatiguing static handgrip (40% of maximal voluntary contraction) increased RVR by 76%. During posthandgrip circulatory arrest, RVR remained above baseline (2.1 +/- 0.2 vs. 2.8 +/- 0.2 arbitrary units; P < 0.017) but was only 40% of the end-grip RVR value. Voluntary biceps contraction increased RVR within 10 s of initiation of contraction. This effect was not associated with an increase in blood pressure. Finally, involuntary biceps contraction also raised RVR. We conclude that muscle contraction evokes renal vasoconstriction in conscious humans. The characteristic of this response is consistent with a primary role for mechanically sensitive afferents. This statement is based on the small posthandgrip circulatory arrest response and the vasoconstriction that was observed with involuntary biceps contraction.

Circulation-Enhancing Device Improves CPR

NASA Technical Reports Server (NTRS)

2007-01-01

Advanced Circulatory Systems, Inc. and NASA's Kennedy Space Center collaborated for five years on impedance threshold device technology. The resulting technology is encapsulated in a device called the ResQPOD Circulatory Enhancer, which improves the standard of care provided to patients with a variety of clinical conditions due to low blood flow. ResQPOD generates negative intrathoracic pressure during respiration to increase blood flow to the body's vital organs. It is unique in that it non-invasively enhances the body's biophysical performance without depending on pharmaceutical or other outside agents. ResQPOD uses the relationship of the heart, brain, lungs and chest cavity in a manner similar to a bellows to increase venous blood return to the heart. Multiple studies have shown a significant improvement in cardiac output and blood flow to the brain with the use of the impedance threshold device, as well as the device's ability to prevent shock secondary to blood loss. ResQPOD has been added to the set of medical equipment that is available for returning astronaut crews, and commercial applications have fallen into two categories: Non-spontaneously breathing patients who can benefit from enhanced circulation, and spontaneously breathing patients who suffer from transient hypotension or low blood pressure.

How Safe Is Safe Enough? Radiation Risk for a Human Mission to Mars

PubMed Central

Cucinotta, Francis A.; Kim, Myung-Hee Y.; Chappell, Lori J.; Huff, Janice L.

2013-01-01

Astronauts on a mission to Mars would be exposed for up to 3 years to galactic cosmic rays (GCR) — made up of high-energy protons and high charge (Z) and energy (E) (HZE) nuclei. GCR exposure rate increases about three times as spacecraft venture out of Earth orbit into deep space where protection of the Earth's magnetosphere and solid body are lost. NASA's radiation standard limits astronaut exposures to a 3% risk of exposure induced death (REID) at the upper 95% confidence interval (CI) of the risk estimate. Fatal cancer risk has been considered the dominant risk for GCR, however recent epidemiological analysis of radiation risks for circulatory diseases allow for predictions of REID for circulatory diseases to be included with cancer risk predictions for space missions. Using NASA's models of risks and uncertainties, we predicted that central estimates for radiation induced mortality and morbidity could exceed 5% and 10% with upper 95% CI near 10% and 20%, respectively for a Mars mission. Additional risks to the central nervous system (CNS) and qualitative differences in the biological effects of GCR compared to terrestrial radiation may significantly increase these estimates, and will require new knowledge to evaluate. PMID:24146746

Colloids Versus Albumin in Large Volume Paracentesis to Prevent Circulatory Dysfunction: Evidence-based Case Report.

PubMed

Widjaja, Felix F; Khairan, Paramita; Kamelia, Telly; Hasan, Irsan

2016-04-01

Large volume paracentesis may cause paracentesis induced circulatory dysfunction (PICD). Albumin is recommended to prevent this abnormality. Meanwhile, the price of albumin is too expensive and there should be another alternative that may prevent PICD. This report aimed to compare albumin to colloids in preventing PICD. Search strategy was done using PubMed, Scopus, Proquest, dan Academic Health Complete from EBSCO with keywords of "ascites", "albumin", "colloid", "dextran", "hydroxyethyl starch", "gelatin", and "paracentesis induced circulatory dysfunction". Articles was limited to randomized clinical trial and meta-analysis with clinical question of "In hepatic cirrhotic patient undergone large volume paracentesis, whether colloids were similar to albumin to prevent PICD". We found one meta-analysis and four randomized clinical trials (RCT). A meta analysis showed that albumin was still superior of which odds ratio 0.34 (0.23-0.51). Three RCTs showed the same results and one RCT showed albumin was not superior than colloids. We conclude that colloids could not constitute albumin to prevent PICD, but colloids still have a role in patient who undergone paracentesis less than five liters.

Effect of task-related extracerebral circulation on diffuse optical tomography: experimental data and simulations on the forehead.

PubMed

Näsi, Tiina; Mäki, Hanna; Hiltunen, Petri; Heiskala, Juha; Nissilä, Ilkka; Kotilahti, Kalle; Ilmoniemi, Risto J

2013-03-01

The effect of task-related extracerebral circulatory changes on diffuse optical tomography (DOT) of brain activation was evaluated using experimental data from 14 healthy human subjects and computer simulations. Total hemoglobin responses to weekday-recitation, verbal-fluency, and hand-motor tasks were measured with a high-density optode grid placed on the forehead. The tasks caused varying levels of mental and physical stress, eliciting extracerebral circulatory changes that the reconstruction algorithm was unable to fully distinguish from cerebral hemodynamic changes, resulting in artifacts in the brain activation images. Crosstalk between intra- and extracranial layers was confirmed by the simulations. The extracerebral effects were attenuated by superficial signal regression and depended to some extent on the heart rate, thus allowing identification of hemodynamic changes related to brain activation during the verbal-fluency task. During the hand-motor task, the extracerebral component was stronger, making the separation less clear. DOT provides a tool for distinguishing extracerebral components from signals of cerebral origin. Especially in the case of strong task-related extracerebral circulatory changes, however, sophisticated reconstruction methods are needed to eliminate crosstalk artifacts.

Biventricular assist device for scombroid poisoning with refractory myocardial dysfunction: a bridge to recovery.

PubMed

Grinda, Jean-Michel; Bellenfant, Florence; Brivet, François Gilles; Carel, Yvan; Deloche, Alain

2004-09-01

We report the usefulness of biventricular mechanical circulatory support in a 36-yr-old woman with refractory myocardial dysfunction resulting from scombroid poisoning. Case report. Medical and surgical university care units. A previously healthy 36-yr-old woman with severe myocardial dysfunction unresponsive to epinephrine (1.3 microg/kg/min) and dobutamine (18 microg/kg/min) after the ingestion of cooked fresh tuna. Implantation at day 3 of a biventricular assist device consisting of two paracorporeal pneumatic pumps set at 70 beats/min to reach an output of 5.6 L/min during 8 days. The biventricular mechanical circulatory assist device allowed weaning of the inotropic drugs, maintenance of end-organ function, and support of the patient until myocardial recovery. The patient was successfully explanted 11 days after ingestion. Cardiac function had totally recovered, but a stroke was noted. At 3-yrs follow-up, there was no cardiac or neurologic sequela. This report describes severe myocardial dysfunction secondary to scombroid poisoning and demonstrates the usefulness of a mechanical circulatory assist device as a bridge to recovery.

Circulatory support for OPCAB procedures.

PubMed

Mueller, Xavier M; von Segesser, Ludwig K

2002-07-01

During off-pump coronary artery bypass grafting (OPCAB) which allows complete revascularization through a median sternotomy, revascularization of the lateral and posterior walls requires the verticalization of the heart, which may cause haemodynamic disturbance. This concern has stimulated the development of circulatory support with mini-pumps. Initially, these pumps were designed for the right side of the heart, which was found to be the main contributor to haemodynamic instability under experimental conditions. The three types of mini-pumps that have been developed so far - two for the right side of the heart and one for both sides - are reviewed as well as a new concept of integrated cardiopulmonary bypass (CPB) circuit with reduced surface and priming volume. However, with increasing experience and improved methods of exposition, OPCAB has become a procedure that can be performed without support in the majority of the cases. Nevertheless, the concept of miniaturization and the possibility to insert these devices through a peripheral access has opened the way to new indications, mainly short-term circulatory support for acute heart failure. This development is welcome in a field where available devices are invasive and plagued with a heavy morbidity.

The total artificial heart

PubMed Central

Cook, Jason A.; Shah, Keyur B.; Quader, Mohammed A.; Cooke, Richard H.; Kasirajan, Vigneshwar; Rao, Kris K.; Smallfield, Melissa C.; Tchoukina, Inna

2015-01-01

The total artificial heart (TAH) is a form of mechanical circulatory support in which the patient’s native ventricles and valves are explanted and replaced by a pneumatically powered artificial heart. Currently, the TAH is approved for use in end-stage biventricular heart failure as a bridge to heart transplantation. However, with an increasing global burden of cardiovascular disease and congestive heart failure, the number of patients with end-stage heart failure awaiting heart transplantation now far exceeds the number of available hearts. As a result, the use of mechanical circulatory support, including the TAH and left ventricular assist device (LVAD), is growing exponentially. The LVAD is already widely used as destination therapy, and destination therapy for the TAH is under investigation. While most patients requiring mechanical circulatory support are effectively treated with LVADs, there is a subset of patients with concurrent right ventricular failure or major structural barriers to LVAD placement in whom TAH may be more appropriate. The history, indications, surgical implantation, post device management, outcomes, complications, and future direction of the TAH are discussed in this review. PMID:26793338

Detection of circulatory microRNAs in prostate cancer.

PubMed

Srivastava, Anvesha; Goldberger, Helle; Afzal, Zainab; Suy, Simeng; Collins, Sean P; Kumar, Deepak

2015-01-01

Prostate cancer (PCa) is one of the most common cancer worldwide and accounts for 14.4 % of all new cancer cases. The clinical outcome and management of PCa can be significantly improved by use of biomarker assays for early detection, prognosis and also for prediction and monitoring of treatment response. MiRNAs are short, endogenous, single-stranded RNA molecules that play important role in regulation of gene expression and can modulate a number of cellular processes. Discovery of miRNAs in circulation has not only facilitated understanding their role in various diseases but also paved new avenues for biomarker discovery due to their ease of access and stability. The fact that a minimally invasive test based on miRNAs profiles can distinguish the presence or absence of disease illustrates immense potential of these molecules as predictive biomarkers.In this chapter, we have summarized the presumed mechanisms of miRNA release into the circulation and systematically summarized the studies of circulatory miRNAs in PCa. Also, we have mainly focused on the methodology of identification of circulatory miRNAs from biofluids.

Computational Conceptual Change: An Explanation-Based Approach

DTIC Science & Technology

2012-06-01

case for students in the control group of Chi et al. (1994a) who (1) explained blood flow in terms of the heart on a pretest , (2) read a textbook...Chi et al. (1994a) who complete a pretest about the circulatory system, read a textbook passage on the topic, and then complete a posttest to assess...model on the posttest . In total, 33% of the control group and 66% of the prompted group reached the correct mental model at the posttest . Results are

Neurochemical phenotypes of cardiorespiratory neurons.

PubMed

Pilowsky, Paul M

2008-12-10

Interactions between the cardiovascular and respiratory systems have been known for many years but the functional significance of the interactions is still widely debated. Here I discuss the possible role of metabotropic receptors in regulating cardiorespiratory neurons in the brainstem and spinal cord. It is clear that, although much has been discovered, cardiorespiratory regulation is certainly one area that still has a long way to go before its secrets are fully divulged and their function in controlling circulatory and respiratory function is revealed.

Heavy Metals and the Petroleum Industr

DTIC Science & Technology

1993-05-01

460 11 Fat Rendering 220 210 70 460 6 Bakery 150 330 430 280 2 Misc. Foods 350 150 110 1100 6 Brewery 410 60 40 470 5 Soft Drinks/ Flavoring 2040 180...arsenic react with -SH groups and can form coordination complexes and chelates with various compounds and structures in the cell .’ The -SH and...important in the function of the human body. It is present in the circulatory system, and a component in the formation of bones and teeth. Calcium is

Measurement of Human Blood and Plasma Volumes

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Szalkay, H. G. H.

1987-01-01

Report reviews techniques for measuring blood-plasma volume in humans. Common technique of using radioactive iodine isotope to label plasma albumin involves unwarranted risks from low-level radiation. Report emphasizes techniques using Evans-blue-dye (T-1824) labeling of albumin, hematocrit or hemoglobin/hematocrit measurements, or blood densitometry. In Evans-blue-dye technique, plasma volume determined from decrease in dye concentration occurring after small amount of dye solution injected into circulatory system. Subjection of Evans blue dye to test for carcinogenicity gave negative results.

Methods of blood flow measurement in the arterial circulatory system.

PubMed

Tabrizchi, R; Pugsley, M K

2000-01-01

The most commonly employed techniques for the in vivo measurement of arterial blood flow to individual organs involve the use of flow probes or sensors. Commercially available systems for the measurement of in vivo blood flow can be divided into two categories: ultrasonic and electromagnetic. Two types of ultrasonic probes are used. The first type of flow probe measures blood flow-mediated Doppler shifts (Doppler flowmetry) in a vessel. The second type of flow probe measures the "transit time" required by an emitted ultrasound wave to traverse the vessel and are transit-time volume flow sensors. Measurement of blood flow in any vessel requires that the flow probe or sensor be highly accurate and exhibit signal linearity over the flow range in the vessel of interest. Moreover, additional desirable features include compact design, size, and weight. An additional important feature for flow probes is that they exhibit good biocompatability; it is imperative for the sensor to behave in an inert manner towards the biological system. A sensitive and reliable method to assess blood flow in individual organs in the body, other than by the use of probes/sensors, is the reference sample method that utilizes hematogeneously delivered microspheres. This method has been utilized to a large extend to assess regional blood flow in the entire body. Obviously, the purpose of measuring blood flow is to determine the amount of blood delivered to a given region per unit time (milliliters per minute) and it is desirable to achieve this goal by noninvasive methodologies. This, however, is not always possible. This review attempts to offer an overview of some of the techniques available for the assessment of regional blood flow in the arterial circulatory system and discusses advantages and disadvantages of these common techniques.

Sociodemographic disparities in the occurrence of medical conditions among adolescent and young adult Hodgkin lymphoma survivors.

PubMed

Keegan, Theresa H M; Li, Qian; Steele, Amy; Alvarez, Elysia M; Brunson, Ann; Flowers, Christopher R; Glaser, Sally L; Wun, Ted

2018-06-01

Hodgkin lymphoma (HL) survivors experience high risks of second cancers and cardiovascular disease, but no studies have considered whether the occurrence of these and other medical conditions differ by sociodemographic factors in adolescent and young adult (AYA) survivors. Data for 5,085 patients aged 15-39 when diagnosed with HL during 1996-2012 and surviving ≥ 2 years were obtained from the California Cancer Registry and linked to hospitalization data. We examined the impact of race/ethnicity, neighborhood socioeconomic status (SES), and health insurance on the occurrence of medical conditions (≥ 2 years after diagnosis) and the impact of medical conditions on survival using multivariable Cox proportional hazards regression. Twenty-six percent of AYAs experienced at least one medical condition and 15% had ≥ 2 medical conditions after treatment for HL. In multivariable analyses, Black HL survivors had a higher likelihood (vs. non-Hispanic Whites) of endocrine [hazard ratio (HR) = 1.37, 95% confidence interval (CI) 1.05-1.78] and circulatory system diseases (HR = 1.58, CI 1.17-2.14); Hispanics had a higher likelihood of endocrine diseases [HR = 1.24 (1.04-1.48)]. AYAs with public or no insurance (vs. private/military) had higher likelihood of circulatory system diseases, respiratory system diseases, chronic kidney disease/renal failure, liver disease, and endocrine diseases. AYAs residing in low SES neighborhoods (vs. high) had higher likelihood of respiratory system and endocrine diseases. AYAs with these medical conditions or second cancers had an over twofold increased risk of death. Strategies to improve health care utilization for surveillance and secondary prevention among AYA HL survivors at increased risk of medical conditions may improve outcomes.

Initial in vitro testing of a paediatric continuous-flow total artificial heart.

PubMed

Fukamachi, Kiyotaka; Karimov, Jamshid H; Horvath, David J; Sunagawa, Gengo; Byram, Nicole A; Kuban, Barry D; Moazami, Nader

2018-06-01

Mechanical circulatory support has become standard therapy for adult patients with end-stage heart failure; however, in paediatric patients with congenital heart disease, the options for chronic mechanical circulatory support are limited to paracorporeal devices or off-label use of devices intended for implantation in adults. Congenital heart disease and cardiomyopathy often involve both the left and right ventricles; in such cases, heart transplantation, a biventricular assist device or a total artificial heart is needed to adequately sustain both pulmonary and systemic circulations. We aimed to evaluate the in vitro performance of the initial prototype of our paediatric continuous-flow total artificial heart. The paediatric continuous-flow total artificial heart pump was downsized from the adult continuous-flow total artificial heart configuration by a scale factor of 0.70 (1/3 of total volume) to enable implantation in infants. System performance of this prototype was evaluated using the continuous-flow total artificial heart mock loop set to mimic paediatric circulation. We generated maps of pump performance and atrial pressure differences over a wide range of systemic vascular resistance/pulmonary vascular resistance and pump speeds. Performance data indicated left pump flow range of 0.4-4.7 l/min at 100 mmHg delta pressure. The left/right atrial pressure difference was maintained within ±5 mmHg with systemic vascular resistance/pulmonary vascular resistance ratios between 1.4 and 35, with/without pump speed modulation, verifying expected passive self-regulation of atrial pressure balance. The paediatric continuous-flow total artificial heart prototype met design requirements for self-regulation and performance; in vivo pump performance studies are ongoing.

[Health status comparative analysis of the emercom of Russia Federal fire service employees and contract servicemen in the Russian Army].

PubMed

Koteev, P K; Kireev, S G; Golovinova, V Iu

2013-08-01

Results of health status comparative analysis of the emercom of Russia Federal fire service employees and contract servicemen in the Russian Army are submitted as following. The emercom of russia firemen's average annual rate of primary morbidity is 459,1, that of labor losses' days 8430,8, of disability 0,9, and mortality cases 0,7. The russian army contract servicemen's average annual rate of primary morbidity during the covered period comes to 410,3, that of discharges 7,4, and mortality cases 1,3. The results of comparative analysis show that the rate of contract servicemen's primary morbidity is lower than that of emercom of Russia firemen below 10.6% (p < 0.001), whereas their discharge level is higher above 87% (p < 0.001). In the course of comparison of the emercom of Russia Federal fire service employees' and the Russian Army contract servicemen's primary morbidity structure it was revealed that the indexes of the diseases of respiratory system, traumas and poisoning are higher among the first ones. On the contrary, their indexes were lower in the sphere of circulatory system, skin and hypodermic cellulose diseases. The indexes of circulatory system diseases in the disability (discharge level) structure of the emercom of Russia Federal fire service employees were higher than those of other diseases. It is expedient to use the results of this research in forming of priority assignments and conducting of a complex of curative and prophylactic measures organized by the medical service of the emercom of Russia.

Feasibility of using a World Health Organization-standard methodology for Sample Vital Registration with Verbal Autopsy (SAVVY) to report leading causes of death in Zambia: results of a pilot in four provinces, 2010.

PubMed

Mudenda, Sheila S; Kamocha, Stanley; Mswia, Robert; Conkling, Martha; Sikanyiti, Palver; Potter, Dara; Mayaka, William C; Marx, Melissa A

2011-08-05

Verbal autopsy (VA) can be used to describe leading causes of death in countries like Zambia where vital events registration does not produce usable data. The objectives of this study were to assess the feasibility of using verbal autopsy to determine age-, sex-, and cause-specific mortality in a community-based setting in Zambia and to estimate overall age-, sex-, and cause-specific mortality in the four provinces sampled. A dedicated census was conducted in regions of four provinces chosen by cluster-sampling methods in January 2010. Deaths in the 12-month period prior to the census were identified during the census. Subsequently, trained field staff conducted verbal autopsy interviews with caregivers or close relatives of the deceased using structured and unstructured questionnaires. Additional deaths were identified and respondents were interviewed during 12 months of fieldwork. After the interviews, two physicians independently reviewed each VA questionnaire to determine a probable cause of death. Among the four provinces (1,056 total deaths) assessed, all-cause mortality rate was 17.2 per 1,000 person-years (95% confidence interval [CI]: 12.4, 22). The seven leading causes of death were HIV/AIDS (287, 27%), malaria (111, 10%), injuries and accidents (81, 8%), diseases of the circulatory system (75, 7%), malnutrition (58, 6%), pneumonia (56, 5%), and tuberculosis (50, 5%). Those who died were more likely to be male, have less than or equal to a primary education, and be unmarried, widowed, or divorced compared to the baseline population. Nearly half (49%) of all reported deaths occurred at home. The 17.2 per 1,000 all-cause mortality rate is somewhat similar to modeled country estimates. The leading causes of death -- HIV/AIDS, malaria, injuries, circulatory diseases, and malnutrition -- reflected causes similar to those reported for the African region and by other countries in the region. Results can enable the targeting of interventions by region, disease, and population to reduce preventable death. Collecting vital statistics using standardized Sample Vital Registration with Verbal Autopsy (SAVVY) methods appears feasible in Zambia. If conducted regularly, these data can be used to evaluate trends in estimated causes of death over time.

An approach estimating the short-term effect of NO2 on daily mortality in Spanish cities.

PubMed

Linares, Cristina; Falcón, Isabel; Ortiz, Cristina; Díaz, Julio

2018-07-01

Road traffic is the most significant source of urban air pollution. PM 2.5 is the air pollutant whose health effects have been most closely studied, and is the variable most commonly used as a proxy indicator of exposure to air pollution, whereas evidence on NO 2 concentrations per se is still under study. In the case of Spain, there are no specific updated studies which calculate short-term NO 2 -related mortality. To quantify the relative risks (RRs) and attributable risks (ARs) of daily mortality associated with NO 2 concentrations recorded in Spain across the study period, 2000-2009; and to calculate the number of NO 2 -related deaths. We calculated daily mortality due to natural causes (ICD-10: A00 R99), circulatory causes (ICD-10: I00 I99) and respiratory causes (ICD-10: J00 J99) for each province across the period 2000-2009, using data supplied by the National Statistics Institute. Mean daily NO 2 concentrations in μg/m 3 for each provincial capital were furnished by the Ministry of Agriculture & Environment, along with the equivalent figures for the control pollutants (PM 10 ). To estimate RRs and ARs, we used generalised linear models with a Poisson link, controlling for maximum and minimum daily temperature, trend of the series, seasonalities, and the autoregressive nature of the series. A meta-analysis with random effects was used to estimate RRs and ARs nationwide. The overall RRs obtained for Spain, corresponding to increases of 10 μg/m 3 in NO 2 concentrations were 1.012 (95% CI: 1.010 1.014) for natural-cause mortality, 1.028 (95% CI: 1.019 1.037) for respiratory-cause mortality, and 1.016 (95% CI: 1.012 1.021) for circulatory-cause mortality. This amounted to an annual overall 6085 deaths (95% CI: 3288 9427) due to natural causes, 1031 (95% CI: 466 1585) due to respiratory causes, and 1978 (95% CI: 828 3197) due to circulatory causes. By virtue of the number of cities involved and the nature of the analysis performed, with quantification of the RRs and ARs of the short-term impact of NO 2 on daily mortality in Spain, this study provides an updated estimate of the effect had by this type of pollutant on causes of mortality, and constitutes an important basis for reinforcing public health measures at a national level. Copyright © 2018 Elsevier Ltd. All rights reserved.

Biomedical Application of Aerospace Personal Cooling Systems

NASA Technical Reports Server (NTRS)

Ku, Yu-Tsuan E.; Lee, Hank C.; Montgomery, Leslie D.; Webbon, Bruce W.; Kliss, Mark (Technical Monitor)

1997-01-01

Personal thermoregulatory systems which are used by astronauts to alleviate thermal stress during extravehicular activity have been applied to the therapeutic management of multiple sclerosis. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to compare the effectiveness of two passive and two active cooling vests and to measure the body temperature and circulatory changes produced by each cooling vest configuration. The MicroClimate Systems and the Life Enhancement Tech(LET) lightweight liquid cooling vests, the Steele Vest and LET's Zipper Front Garment were used to cool the chest region of 10 male and female subjects (25 to 55 yr.) in this study. Calf, forearm and finger blood flows were measured using a tetrapolar impedance rheograph. The subjects, seated in an upright position at normal room temperature (approx.22C), were tested for 60 min. with the cooling system operated at its maximum cooling capacity. Blood flows were recorded continuously using a computer data acquisition system with a sampling frequency of 250 Hz. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; respiration; and an activity index were recorded continuously on a U.F.I., Inc. Biolog ambulatory monitor. In general, the male and female subjects' oral and ear temperature responses to cooling were similar for all vest configurations tested. Oral temperatures during the recovery period were significantly (P<0.05) lower than during the control period, approx. 0.2 - 0.5C, for both men and women wearing any of the four different garments. The corresponding ear temperatures were significantly (P<0.05) decreased approx.0.2 - 0.4C by the end of the recovery period. Compared to the control period, no significant differences were found in rectal temperatures during cooling and recovery periods.

[Identifying children at risk for cardiorespiratory arrest].

PubMed

Carrillo Alvarez, A; Martínez Gutiérrez, A; Salvat Germán, F

2004-08-01

Cardiorespiratory arrest in children with severe disease does not usually present suddenly or unexpectedly but is often the result of a progressive deterioration of respiratory and/or circulatory function. Before failure of these functions occurs, there is a series of clinical signs that serve as a warning. Health professionals should not only evaluate clinical signs of respiratory and/or circulatory insufficiency but should also be able to identify these warning signs as early as possible, preferably in the compensation phase, given that the possibility that this process can be reversed by therapeutic measures decreases as the process progresses.

Circulatory Shock. Volume 34. Number 1. May 1991. International Conference on Shock (2nd), Meeting of European Shock Society (5th), Annual Meeting of the Shock Society (USA) (14th), Vienna Shock Form (3rd) Held in Vienna, Austria on 2-6 June 1991

DTIC Science & Technology

1991-06-06

OCTADECENOATE, AS A BURN TOXIN Takayuki Ozawa, Mika Hayakawa, Kazuhiro Kosaka, Satoru Sugiyama, Kazuhisa Yokoo, Hisashi Aoyama, and Yohei Izawa Department...shock. 41 CARDIOPULMONARY HEMODYNAMIC AND PERIPHERAL CIRCULATORY RESPONSES IN SHOCK T. Muteki, N. Kaku. T. Fukushige, I. Kohno and T. Hiraki Department...Tadashi, 242 Machleidt, Werner, 213 Ozawa, Takayuki , 11 Kawarada, Yoshifumi, 442 Mackie, D.P., 348 Ozawa, Kazue, 268 Keser, Claudia, 380 Maitra, Subir R

Toward total implantability using free-range resonant electrical energy delivery system: achieving untethered ventricular assist device operation over large distances.

PubMed

Waters, Benjamin; Sample, Alanson; Smith, Joshua; Bonde, Pramod

2011-11-01

Heart failure is a terminal disease with a very poor prognosis. Although the gold standard of treatment remains heart transplant, only a minority of patients can benefit from transplants. Another promising alternative is mechanical circulatory assistance using ventricular assist devices. The authors envision a completely implantable cardiac assist system affording tether-free mobility in an unrestricted space powered wirelessly by the innovative Free-Range Resonant Electrical Energy Device (FREE-D) system. Patients will have no power drivelines traversing the skin, and this system will allow power to be delivered over room distances and will eliminate trouble-prone wirings, bulky consoles, and replaceable batteries. Copyright © 2011 Elsevier Inc. All rights reserved.

A novel combination technique of cold crystalloid perfusion but not cold storage facilitates transplantation of canine hearts donated after circulatory death.

PubMed

Rosenfeldt, Franklin; Ou, Ruchong; Salamonsen, Robert; Marasco, Silvana; Zimmet, Adam; Byrne, Joshua; Cosic, Filip; Saxena, Pankaj; Esmore, Donald

2016-11-01

Donation after circulatory death (DCD) represents a potential new source of hearts to increase the donor pool. We showed previously that DCD hearts in Greyhound dogs could be resuscitated and preserved by continuous cold crystalloid perfusion but not by cold static storage and could demonstrate excellent contractile and metabolic function on an in vitro system. In the current study, we demonstrate that resuscitated DCD hearts are transplantable. Donor Greyhound dogs (n = 12) were divided into perfusion (n = 8) and cold static storage (n = 4) groups. General anesthesia was induced and ventilation ceased for 30 minutes to achieve circulatory death. Donor cardiectomy was performed, and for 4 hours the heart was preserved by controlled reperfusion, followed by continuous cold perfusion with an oxygenated crystalloid perfusate or by static cold storage, after which orthotopic heart transplantation was performed. Recovery was assessed over 4 hours by hemodynamic monitoring. During cold perfusion, hearts showed continuous oxygen consumption and low lactate levels, indicating aerobic metabolism. The 8 dogs in the perfusion group were weaned off bypass, and 4 hours after bypass produced cardiac output of 4.73 ± 0.51 liters/min, left ventricular power of 7.63 ± 1.32 J/s, right ventricular power of 1.40 ± 0.43 J/s, and left ventricular fractional area shortening of 39.1% ± 5.2%, all comparable to pre-transplant values. In the cold storage group, 3 of 4 animals could not be weaned from cardiopulmonary bypass, and the fourth exhibited low-level function. Cold crystalloid perfusion, but not cold static storage, can resuscitate and preserve the DCD donor heart in a canine model of heart transplantation, thus rendering it transplantable. Controlled reperfusion and cold crystalloid perfusion have potential for clinical application in DCD transplantation. Copyright © 2016. Published by Elsevier Inc.

CIRCULATORY FAILURE DURING NON-INHALED FORMS OF CYANIDE INTOXICATION

PubMed Central

Haouzi, Philippe; Tubbs, Nicole; Rannals, Matthew D.; Judenherc-Haouzi, Annick; Cabell, Larry A.; McDonough, Joe A.; Sonobe, Takashi

2016-01-01

Our objective was to determine how circulatory failure develops following systemic administration of potassium cyanide (KCN). We used a non-inhaled modality of intoxication, wherein the change in breathing pattern would not influence the diffusion of CN into the blood, akin to the effects of ingesting toxic levels of CN. In a group of 300–400 g rats, CN-induced coma (CN IP, 7 mg/kg) produced a central apnea within 2–3 minutes along with a potent and prolonged gasping pattern leading to auto-resuscitation in 38% of the animals. Motor deficits and neuronal necrosis were nevertheless observed in the surviving animals. To clarify the mechanisms leading to potential auto-resuscitation versus asystole, 12 urethane-anesthetized rats were then exposed to the lowest possible levels of CN exposure that would lead to breathing depression within 7–8 minutes; this dose averaged 0.375 mg/kg/min iv. At this level of intoxication, a cardiac depression developed several minutes only after the onset of the apnea, leading to cardiac asystole as PaO2 reached value around 15 Torr, unless breathing was maintained by mechanical ventilation or through spontaneous gasping. Higher levels of KCN exposure in 10 animals provoked a primary cardiac depression, which led to a rapid cardiac arrest by pulseless electrical activity despite the maintenance of PaO2 by mechanical ventilation. These effects were totally unrelated to the potassium contained in KCN. It is concluded that circulatory failure can develop as a direct consequence of CN induced apnea but in a narrow range of exposure. In this “low” range, maintaining pulmonary gas exchange after exposure, through mechanical ventilation (or spontaneous gasping) can reverse cardiac depression and restore spontaneous breathing. At higher level of intoxication, cardiac depression is to be treated as a specific and spontaneously irreversible consequence of CN exposure, leading to a pulseless electrical activity. PMID:27513083

Early microvascular changes in the preterm neonate: a comparative study of the human and guinea pig.

PubMed

Dyson, Rebecca M; Palliser, Hannah K; Lakkundi, Anil; de Waal, Koert; Latter, Joanna L; Clifton, Vicki L; Wright, Ian M R

2014-09-17

Dysfunction of the transition from fetal to neonatal circulatory systems may be a major contributor to poor outcome following preterm birth. Evidence exists in the human for both a period of low flow between 5 and 11 h and a later period of increased flow, suggesting a hypoperfusion-reperfusion cycle over the first 24 h following birth. Little is known about the regulation of peripheral blood flow during this time. The aim of this study was to conduct a comparative study between the human and guinea pig to characterize peripheral microvascular behavior during circulatory transition. Very preterm (≤28 weeks GA), preterm (29-36 weeks GA), and term (≥37 weeks GA) human neonates underwent laser Doppler analysis of skin microvascular blood flow at 6 and 24 h from birth. Guinea pig neonates were delivered prematurely (62 day GA) or at term (68-71 day GA) and laser Doppler analysis of skin microvascular blood flow was assessed every 2 h from birth. In human preterm neonates, there is a period of high microvascular flow at 24 h after birth. No period of low flow was observed at 6 h. In preterm animals, microvascular flow increased after birth, reaching a peak at 10 h postnatal age. Blood flow then steadily decreased, returning to delivery levels by 24 h. Preterm birth was associated with higher baseline microvascular flow throughout the study period in both human and guinea pig neonates. The findings do not support a hypoperfusion-reperfusion cycle in the microcirculation during circulatory transition. The guinea pig model of preterm birth will allow further investigation of the mechanisms underlying microvascular function and dysfunction during the initial extrauterine period. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Utilization of the Organ Care System Lung for the assessment of lungs from a donor after cardiac death (DCD) before bilateral transplantation.

PubMed

Mohite, P N; Sabashnikov, A; García Sáez, D; Pates, B; Zeriouh, M; De Robertis, F; Simon, A R

2015-07-01

In this manuscript, we present the first experience of evaluating donation after circulatory death (DCD) lungs, using the normothermic preservation Organ Care System (OCS) and subsequent successful transplantation. The OCS could be a useful tool for the evaluation of marginal lungs from DCD donors as it allows a proper recruitment and bronchoscopy in such donations in addition to continuous ex-vivo perfusion and assessment and treatment during transport. The OCS could potentially be a standard of care in the evaluation of marginal lungs from DCD. © The Author(s) 2014.

Endocannabinoids as mediators in the heart: a potential target for therapy of remodelling after myocardial infarction?

PubMed Central

Hiley, C Robin; Ford, William R

2003-01-01

Endocannabinoid production by platelets and macrophages is increased in circulatory shock. This may be protective of the cardiovascular system as blockade of CB1 cannabinoid receptors exacerbates endothelial dysfunction in haemorrhagic and endotoxin shock and reduces survival. Now evidence suggests that blockade of CB1 receptors starting 24 h after myocardial infarction in rats has a deleterious effect on cardiac performance, while use of a nonselective cannabinoid receptor agonist prevents hypotension and reduces endothelial dysfunction, although left ventricular end diastolic pressure is elevated. Cannabinoids and endocannabinoid systems may therefore present useful targets for therapy following myocardial infarction. PMID:12711614

Self sufficient wireless transmitter powered by foot-pumped urine operating wearable MFC.

PubMed

Taghavi, M; Stinchcombe, A; Greenman, J; Mattoli, V; Beccai, L; Mazzolai, B; Melhuish, C; Ieropoulos, I A

2015-12-10

The first self-sufficient system, powered by a wearable energy generator based on microbial fuel cell (MFC) technology is introduced. MFCs made from compliant material were developed in the frame of a pair of socks, which was fed by urine via a manual gaiting pump. The simple and single loop cardiovascular fish circulatory system was used as the inspiration for the design of the manual pump. A wireless programmable communication module, engineered to operate within the range of the generated electricity, was employed, which opens a new avenue for research in the utilisation of waste products for powering portable as well as wearable electronics.

The effect of extreme cold temperatures on the risk of death in the two major Portuguese cities

NASA Astrophysics Data System (ADS)

Antunes, Liliana; Silva, Susana Pereira; Marques, Jorge; Nunes, Baltazar; Antunes, Sílvia

2017-01-01

It is well known that meteorological conditions influence the comfort and human health. Southern European countries, including Portugal, show the highest mortality rates during winter, but the effects of extreme cold temperatures in Portugal have never been estimated. The objective of this study was the estimation of the effect of extreme cold temperatures on the risk of death in Lisbon and Oporto, aiming the production of scientific evidence for the development of a real-time health warning system. Poisson regression models combined with distributed lag non-linear models were applied to assess the exposure-response relation and lag patterns of the association between minimum temperature and all-causes mortality and between minimum temperature and circulatory and respiratory system diseases mortality from 1992 to 2012, stratified by age, for the period from November to March. The analysis was adjusted for over dispersion and population size, for the confounding effect of influenza epidemics and controlled for long-term trend, seasonality and day of the week. Results showed that the effect of cold temperatures in mortality was not immediate, presenting a 1-2-day delay, reaching maximum increased risk of death after 6-7 days and lasting up to 20-28 days. The overall effect was generally higher and more persistent in Lisbon than in Oporto, particularly for circulatory and respiratory mortality and for the elderly. Exposure to cold temperatures is an important public health problem for a relevant part of the Portuguese population, in particular in Lisbon.

Progression of Mortality due to Diseases of the Circulatory System and Human Development Index in Rio de Janeiro Municipalities

PubMed Central

Soares, Gabriel Porto; Klein, Carlos Henrique; Silva, Nelson Albuquerque de Souza e; de Oliveira, Glaucia Maria Moraes

2016-01-01

Background Diseases of the circulatory system (DCS) are the major cause of death in Brazil and worldwide. Objective To correlate the compensated and adjusted mortality rates due to DCS in the Rio de Janeiro State municipalities between 1979 and 2010 with the Human Development Index (HDI) from 1970 onwards. Methods Population and death data were obtained in DATASUS/MS database. Mortality rates due to ischemic heart diseases (IHD), cerebrovascular diseases (CBVD) and DCS adjusted by using the direct method and compensated for ill-defined causes. The HDI data were obtained at the Brazilian Institute of Applied Research in Economics. The mortality rates and HDI values were correlated by estimating Pearson linear coefficients. The correlation coefficients between the mortality rates of census years 1991, 2000 and 2010 and HDI data of census years 1970, 1980 and 1991 were calculated with discrepancy of two demographic censuses. The linear regression coefficients were estimated with disease as the dependent variable and HDI as the independent variable. Results In recent decades, there was a reduction in mortality due to DCS in all Rio de Janeiro State municipalities, mainly because of the decline in mortality due to CBVD, which was preceded by an elevation in HDI. There was a strong correlation between the socioeconomic indicator and mortality rates. Conclusion The HDI progression showed a strong correlation with the decline in mortality due to DCS, signaling to the relevance of improvements in life conditions. PMID:27849263

Progression of Mortality due to Diseases of the Circulatory System and Human Development Index in Rio de Janeiro Municipalities.

PubMed

Soares, Gabriel Porto; Klein, Carlos Henrique; Silva, Nelson Albuquerque de Souza E; Oliveira, Glaucia Maria Moraes de

2016-10-01

Diseases of the circulatory system (DCS) are the major cause of death in Brazil and worldwide. To correlate the compensated and adjusted mortality rates due to DCS in the Rio de Janeiro State municipalities between 1979 and 2010 with the Human Development Index (HDI) from 1970 onwards. Population and death data were obtained in DATASUS/MS database. Mortality rates due to ischemic heart diseases (IHD), cerebrovascular diseases (CBVD) and DCS adjusted by using the direct method and compensated for ill-defined causes. The HDI data were obtained at the Brazilian Institute of Applied Research in Economics. The mortality rates and HDI values were correlated by estimating Pearson linear coefficients. The correlation coefficients between the mortality rates of census years 1991, 2000 and 2010 and HDI data of census years 1970, 1980 and 1991 were calculated with discrepancy of two demographic censuses. The linear regression coefficients were estimated with disease as the dependent variable and HDI as the independent variable. In recent decades, there was a reduction in mortality due to DCS in all Rio de Janeiro State municipalities, mainly because of the decline in mortality due to CBVD, which was preceded by an elevation in HDI. There was a strong correlation between the socioeconomic indicator and mortality rates. The HDI progression showed a strong correlation with the decline in mortality due to DCS, signaling to the relevance of improvements in life conditions.

Activation of PI3K/Akt signaling in rostral ventrolateral medulla impairs brain stem cardiovascular regulation that underpins circulatory depression during mevinphos intoxication.

PubMed

Tsai, Ching-Yi; Chang, Alice Y W; Chan, Julie Y H; Chan, Samuel H H

2014-03-01

As the most widely used pesticides in the globe, the organophosphate compounds are understandably linked with the highest incidence of suicidal poisoning. Whereas the elicited toxicity is often associated with circulatory depression, the underlying mechanisms require further delineation. Employing the pesticide mevinphos as our experimental tool, we evaluated the hypothesis that transcriptional upregulation of nitric oxide synthase II (NOS II) by NF-κB on activation of the PI3K/Akt cascade in the rostral ventrolateral medulla (RVLM), the brain stem site that maintains blood pressure and sympathetic vasomotor tone, underpins the circulatory depressive effects of organophosphate poisons. Microinjection of mevinphos (10 nmol) bilaterally into the RVLM of anesthetized Sprague-Dawley rats induced a progressive hypotension that was accompanied sequentially by an increase (Phase I) and a decrease (Phase II) of an experimental index for the baroreflex-mediated sympathetic vasomotor tone. There were also progressive augmentations in PI3K or Akt enzyme activity and phosphorylation of p85 or Akt(Thr308) subunit in the RVLM that were causally related to an increase in NF-κB transcription activity and elevation in NOS II or peroxynitrite expression. Loss-of-function manipulations of PI3K or Akt in the RVLM significantly antagonized the reduced baroreflex-mediated sympathetic vasomotor tone and hypotension during Phase II mevinphos intoxication, and blunted the increase in NF-κB/NOS II/peroxynitrite signaling. We conclude that activation of the PI3K/Akt cascade, leading to upregulation of NF-κB/NOS II/peroxynitrite signaling in the RVLM, elicits impairment of brain stem cardiovascular regulation that underpins circulatory depression during mevinphos intoxication. Copyright © 2014 Elsevier Inc. All rights reserved.

Is gender policy related to the gender gap in external cause and circulatory disease mortality? A mixed effects model of 22 OECD countries 1973-2008.

PubMed

Backhans, Mona; Burström, Bo; de Leon, Antonio Ponce; Marklund, Staffan

2012-11-12

Gender differences in mortality vary widely between countries and over time, but few studies have examined predictors of these variations, apart from smoking. The aim of this study is to investigate the link between gender policy and the gender gap in cause-specific mortality, adjusted for economic factors and health behaviours. 22 OECD countries were followed 1973-2008 and the outcomes were gender gaps in external cause and circulatory disease mortality. A previously found country cluster solution was used, which includes indicators on taxes, parental leave, pensions, social insurances and social services in kind. Male breadwinner countries were made reference group and compared to earner-carer, compensatory breadwinner, and universal citizen countries. Specific policies were also analysed. Mixed effect models were used, where years were the level 1-units, and countries were the level 2-units. Both the earner-carer cluster (ns after adjustment for GDP) and policies characteristic of that cluster are associated with smaller gender differences in external causes, particularly due to an association with increased female mortality. Cluster differences in the gender gap in circulatory disease mortality are the result of a larger relative decrease of male mortality in the compensatory breadwinner cluster and the earner-carer cluster. Policies characteristic of those clusters were however generally related to increased mortality. Results for external cause mortality are in concordance with the hypothesis that women become more exposed to risks of accident and violence when they are economically more active. For circulatory disease mortality, results differ depending on approach--cluster or indicator. Whether cluster differences not explained by specific policies reflect other welfare policies or unrelated societal trends is an open question. Recommendations for further studies are made.

A comprehensive Guyton model analysis of physiologic responses to preadapting the blood volume as a countermeasure to fluid shifts

NASA Technical Reports Server (NTRS)

Simanonok, K. E.; Srinivasan, R. S.; Myrick, E. E.; Blomkalns, A. L.; Charles, J. B.

1994-01-01

The Guyton model of fluid, electrolyte, and circulatory regulation is an extensive mathematical model capable of simulating a variety of experimental conditions. It has been modified for use at NASA to simulate head-down tilt, a frequently used analog of weightlessness. Weightlessness causes a headward shift of body fluids that is believed to expand central blood volume, triggering a series of physiologic responses resulting in large losses of body fluids. We used the modified Guyton model to test the hypothesis that preadaptation of the blood volume before weightless exposure could counteract the central volume expansion caused by fluid shifts, and thereby attenuate the circulatory and renal responses that result in body fluid losses. Simulation results show that circulatory preadaptation, by a procedure resembling blood donation immediately before head-down bedrest, is effective in damping the physiologic responses to fluid shifts and reducing body fluid losses. After 10 hours of head-down tilt, preadaptation also produces higher blood volume, extracellular volume, and total body water for 20 to 30 days of bedrest, compared with non-preadapted control. These results indicate that circulatory preadaptation before current Space Shuttle missions may be beneficial for the maintenance of reentry and postflight orthostatic tolerance in astronauts. This paper presents a comprehensive examination of the simulation results pertaining to changes in relevant physiologic variables produced by blood volume reduction before a prolonged head-down tilt. The objectives were to study and develop the countermeasure theoretically, to aid in planning experimental studies of the countermeasure, and to identify potentially disadvantageous physiologic responses that may be caused by the countermeasure.

Causes and Consequences of Missing Health-Related Quality of Life Assessments in Patients Who Undergo Mechanical Circulatory Support Implantation: Insights From INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support).

PubMed

Grady, Kathleen L; Jones, Philip G; Cristian-Andrei, Adin; Naftel, David C; Myers, Susan; Dew, Mary Amanda; Idrissi, Katharine; Weidner, Gerdi; Wissman, Sherri A; Kirklin, James K; Spertus, John A

2017-12-01

Missing health-related quality of life (HRQOL) data in longitudinal studies can reduce precision and power and bias results. Using INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support), we sought to identify factors associated with missing HRQOL data, examine the impact of these factors on estimated HRQOL assuming missing at random missingness, and perform sensitivity analyses to examine missing not at random (MNAR) missingness because of illness severity. INTERMACS patients (n=3248) with a preimplantation profile of 1 (critical cardiogenic shock) or 2 (progressive decline) were assessed with the EQ-5D-3L visual analog scale and Kansas City Cardiomyopathy Questionnaire-12 summary scores pre-implantation and 3 months postoperatively. Mean and median observed and missing at random-imputed HRQOL scores were calculated, followed by sensitivity analyses. Independent factors associated with HRQOL scores and missing HRQOL assessments were determined using multivariable regression. Independent factors associated with preimplantation and 3-month HRQOL scores, and with the likelihood of missing HRQOL assessments, revealed few correlates of HRQOL and missing assessments ( R 2 range, 4.7%-11.9%). For patients with INTERMACS profiles 1 and 2 and INTERMACS profile 1 alone, missing at random-imputed mean and median HRQOL scores were similar to observed scores, before and 3 months after implantation, whereas MNAR-imputed mean scores were lower (≥5 points) at baseline but not at 3 months. We recommend use of sensitivity analyses using an MNAR imputation strategy for longitudinal studies when missingness is attributable to illness severity. Conduct of MNAR sensitivity analyses may be less critical after mechanical circulatory support implant, when there are likely fewer MNAR data. © 2017 American Heart Association, Inc.

On the Mechanism of Human Red Blood Cell Longevity: Roles of Calcium, the Sodium Pump, PIEZO1, and Gardos Channels.

PubMed

Lew, Virgilio L; Tiffert, Teresa

2017-01-01

In a healthy adult, the transport of O 2 and CO 2 between lungs and tissues is performed by about 2 · 10 13 red blood cells, of which around 1.7 · 10 11 are renewed every day, a turnover resulting from an average circulatory lifespan of about 120 days. Cellular lifespan is the result of an evolutionary balance between the energy costs of maintaining cells in a fit functional state versus cell renewal. In this Review we examine how the set of passive and active membrane transporters of the mature red blood cells interact to maximize their circulatory longevity thus minimizing costs on expensive cell turnover. Red blood cell deformability is critical for optimal rheology and gas exchange functionality during capillary flow, best fulfilled when the volume of each human red blood cell is kept at a fraction of about 0.55-0.60 of the maximal spherical volume allowed by its membrane area, the optimal-volume-ratio range. The extent to which red blood cell volumes can be preserved within or near these narrow optimal-volume-ratio margins determines the potential for circulatory longevity. We show that the low cation permeability of red blood cells allows volume stability to be achieved with extraordinary cost-efficiency, favouring cell longevity over cell turnover. We suggest a mechanism by which the interplay of a declining sodium pump and two passive membrane transporters, the mechanosensitive PIEZO1 channel, a candidate mediator of P sickle in sickle cells, and the Ca 2+ -sensitive, K + -selective Gardos channel, can implement red blood cell volume stability around the optimal-volume-ratio range, as required for extended circulatory longevity.

Delayed Referral Results in Missed Opportunities for Organ Donation After Circulatory Death.

PubMed

Krmpotic, Kristina; Payne, Clare; Isenor, Cynthia; Dhanani, Sonny

2017-06-01

Rates of organ donation and transplantation have steadily increased in the United States and Canada over the past decade, largely attributable to a notable increase in donation after circulatory death. However, the number of patients awaiting solid organ transplantation continues to remain much higher than the number of organs transplanted each year. The objective of this study was to determine the potential to increase donation rates further by identifying gaps in the well-established donation after circulatory death process in Ontario. Retrospective cohort study. Provincial organ procurement organization. Patients who died in designated donation hospitals within the province of Ontario, Canada between April 1, 2013, and March 31, 2015. None. Of 1,407 patient deaths following planned withdrawal of life-sustaining therapy, 54.0% (n = 760) were medically suitable for donation after circulatory death. In 438 cases where next of kin was approached, consent rates reached 47.5%. A total of 119 patients became actual organ donors. Only 66.2% (n = 503) of suitable patients were appropriately referred, resulting in 251 missed potential donors whose next of kin could not be approached regarding organ donation because referral occurred after initiation of withdrawal of life-sustaining therapy or not at all. The number of medically suitable patients who die within 2 hours of planned withdrawal of life-sustaining therapy is nearly six times higher than the number of actual organ donors, with the greatest loss of potential due to delayed referral until at the time of or after planned withdrawal of life-sustaining therapy. Intensive care teams are not meeting their ethical responsibility to recognize impending death and appropriately refer potential organ donors to the local organ procurement organization. In cases where patients had previously registered their consent decision, they were denied a healthcare right.

On the Mechanism of Human Red Blood Cell Longevity: Roles of Calcium, the Sodium Pump, PIEZO1, and Gardos Channels

PubMed Central

Lew, Virgilio L.; Tiffert, Teresa

2017-01-01

In a healthy adult, the transport of O2 and CO2 between lungs and tissues is performed by about 2 · 1013 red blood cells, of which around 1.7 · 1011 are renewed every day, a turnover resulting from an average circulatory lifespan of about 120 days. Cellular lifespan is the result of an evolutionary balance between the energy costs of maintaining cells in a fit functional state versus cell renewal. In this Review we examine how the set of passive and active membrane transporters of the mature red blood cells interact to maximize their circulatory longevity thus minimizing costs on expensive cell turnover. Red blood cell deformability is critical for optimal rheology and gas exchange functionality during capillary flow, best fulfilled when the volume of each human red blood cell is kept at a fraction of about 0.55–0.60 of the maximal spherical volume allowed by its membrane area, the optimal-volume-ratio range. The extent to which red blood cell volumes can be preserved within or near these narrow optimal-volume-ratio margins determines the potential for circulatory longevity. We show that the low cation permeability of red blood cells allows volume stability to be achieved with extraordinary cost-efficiency, favouring cell longevity over cell turnover. We suggest a mechanism by which the interplay of a declining sodium pump and two passive membrane transporters, the mechanosensitive PIEZO1 channel, a candidate mediator of Psickle in sickle cells, and the Ca2+-sensitive, K+-selective Gardos channel, can implement red blood cell volume stability around the optimal-volume-ratio range, as required for extended circulatory longevity. PMID:29311949

End-of-life practices in patients with devastating brain injury in Spain: implications for organ donation.

PubMed

Domínguez-Gil, B; Coll, E; Pont, T; Lebrón, M; Miñambres, E; Coronil, A; Quindós, B; Herrero, J E; Liébanas, C; Marcelo, B; Sanmartín, A M; Matesanz, R

2017-04-01

To describe end-of-life care practices relevant to organ donation in patients with devastating brain injury in Spain. A multicenter prospective study of a retrospective cohort. 1 November 2014 to 30 April 2015. Sixty-eight hospitals authorized for organ procurement. Patients dying from devastating brain injury (possible donors). Age: 1 month-85 years. Type of care, donation after brain death, donation after circulatory death, intubation/ventilation, referral to the donor coordinator. A total of 1,970 possible donors were identified, of which half received active treatment in an Intensive Care Unit (ICU) until brain death (27%), cardiac arrest (5%) or the withdrawal of life-sustaining therapy (19%). Of the rest, 10% were admitted to the ICU to facilitate organ donation, while 39% were not admitted to the ICU. Of those patients who evolved to a brain death condition (n=695), most transitioned to actual donation (n=446; 64%). Of those who died following the withdrawal of life-sustaining therapy (n=537), 45 (8%) were converted into actual donation after circulatory death donors. The lack of a dedicated donation after circulatory death program was the main reason for non-donation. Thirty-seven percent of the possible donors were not intubated/ventilated at death, mainly because the professional in charge did not consider donation alter discarding therapeutic intubation. Thirty-six percent of the possible donors were never referred to the donor coordinator. Although deceased donation is optimized in Spain, there are still opportunities for improvement in the identification of possible donors outside the ICU and in the consideration of donation after circulatory death in patients who die following the withdrawal of life-sustaining therapy. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Does the arterial cannulation site for circulatory arrest influence stroke risk?

PubMed

Svensson, Lars G; Blackstone, Eugene H; Rajeswaran, Jeevanantham; Sabik, Joseph F; Lytle, Bruce W; Gonzalez-Stawinski, Gonzalo; Varvitsiotis, Poseidon; Banbury, Michael K; McCarthy, Patrick M; Pettersson, Gösta B; Cosgrove, Delos M

2004-10-01

We investigated whether axillary/subclavian artery inflow with a side graft decreases the risk of stroke versus cannulation at other sites during hypothermic circulatory arrest. Between January 1993 and May 2003, 1,352 operations with circulatory arrest were performed for complex adult cardiac problems. A single arterial inflow cannulation site was used in 1,336 operations, and these formed the basis for comparative analyses. Cannulation sites were axillary plus graft in 299 operations, direct cannulation of the aorta in 471, femoral in 375, innominate in 24, and axillary or subclavian without a side graft in 167. Retrograde brain perfusion was used in 933 (69%). A total of 272 (20%) were for emergencies, 432 (32%) were reoperations, and 439 (32%) were for dissections. A total of 617 (46%) had aortic valve replacement and 1,160 (87%) ascending, 415 arch (31%), and 248 descending (18%) aortic replacements. Indications also included arteriosclerosis (n = 301) and calcified aorta (n = 278). Primary comparisons were made by using propensity matching, and, secondarily, risk factors for stroke or hospital mortality were identified by multivariable logistic regression. Stroke occurred in 6.1% of patients (81/1,336): 4.0% (12/299) of those had axillary plus graft and 6.7% who had direct cannulation (69/1,037; p = 0.09; p = 0.05 among propensity-matched pairs). Operative variables associated with stroke included direct aortic cannulation, aortic arteriosclerosis, descending aorta repair, and mitral valve replacement. The risk of hospital mortality was higher (11%; 42/375) for patients who had femoral cannulation than axillary plus graft (7.0%; 21/299; p = 0.06; p = 0.02 among propensity-matched pairs). Axillary inflow plus graft reduces stroke and is our method of choice for complex cardiac and cardioaortic operations that necessitate circulatory arrest. Retrograde or antegrade perfusion is used selectively.

von Willebrand factor, Jedi knight of the bloodstream.

PubMed

Springer, Timothy A

2014-08-28

When blood vessels are cut, the forces in the bloodstream increase and change character. The dark side of these forces causes hemorrhage and death. However, von Willebrand factor (VWF), with help from our circulatory system and platelets, harnesses the same forces to form a hemostatic plug. Force and VWF function are so closely intertwined that, like members of the Jedi Order in the movie Star Wars who learn to use "the Force" to do good, VWF may be considered the Jedi knight of the bloodstream. The long length of VWF enables responsiveness to flow. The shape of VWF is predicted to alter from irregularly coiled to extended thread-like in the transition from shear to elongational flow at sites of hemostasis and thrombosis. Elongational force propagated through the length of VWF in its thread-like shape exposes its monomers for multimeric binding to platelets and subendothelium and likely also increases affinity of the A1 domain for platelets. Specialized domains concatenate and compact VWF during biosynthesis. A2 domain unfolding by hydrodynamic force enables postsecretion regulation of VWF length. Mutations in VWF in von Willebrand disease contribute to and are illuminated by VWF biology. I attempt to integrate classic studies on the physiology of hemostatic plug formation into modern molecular understanding, and point out what remains to be learned. © 2014 by The American Society of Hematology.

Discrete Element Model for Suppression of Coffee-Ring Effect

NASA Astrophysics Data System (ADS)

Xu, Ting; Lam, Miu Ling; Chen, Ting-Hsuan

2017-02-01

When a sessile droplet evaporates, coffee-ring effect drives the suspended particulate matters to the droplet edge, eventually forming a ring-shaped deposition. Because it causes a non-uniform distribution of solid contents, which is undesired in many applications, attempts have been made to eliminate the coffee-ring effect. Recent reports indicated that the coffee-ring effect can be suppressed by a mixture of spherical and non-spherical particles with enhanced particle-particle interaction at air-water interface. However, a model to comprehend the inter-particulate activities has been lacking. Here, we report a discrete element model (particle system) to investigate the phenomenon. The modeled dynamics included particle traveling following the capillary flow with Brownian motion, and its resultant 3D hexagonal close packing of particles along the contact line. For particles being adsorbed by air-water interface, we modeled cluster growth, cluster deformation, and cluster combination. We found that the suppression of coffee-ring effect does not require a circulatory flow driven by an inward Marangoni flow at air-water interface. Instead, the number of new cluster formation, which can be enhanced by increasing the ratio of non-spherical particles and the overall number of microspheres, is more dominant in the suppression process. Together, this model provides a useful platform elucidating insights for suppressing coffee-ring effect for practical applications in the future.

A novel nonenzymatic cascade amplification for ultrasensitive photoelectrochemical DNA sensing based on target driven to initiate cyclic assembly of hairpins.

PubMed

Wen, Guangming; Dong, Wenxia; Liu, Bin; Li, Zhongping; Fan, Lifang

2018-05-29

A novel cascade photoelectrochemical (PEC) signal amplification biosensing tactics was developed for DNA detection based on a target-driven DNA association to induce cyclic hairpin assembly. In the circulatory system there are two ssDNA (A and B) and two hairpins (C and D). The hybridization of these ssDNA led to the formation of an A-target-B structure. The close proximity of their toehold and branch-migration regions was able to induce the cyclic hairpin assembly. Afterwards, the assembly result further causes the separation of a double-stranded probe DNA (Q:F) to switch the PEC signal via toehold-mediated strand replacement. As such, the signal stranded DNA-CdS QDs (F) as the signal tag was released in the presence of the target DNA. The signal DNA-CdS QDs was then coated to F-doped tin oxide (FTO) electrode leading to the "signal-on" PEC signal. The designed biosensing strategy showed a low detection limit of 21.3 pM for target DNA and a broad linear range from 50 pM to 100 nM. This signal amplification PEC sensing method exhibited a potential application to detect protein molecules, RNA or metal ions via changing the sequence of A and B recognition. Copyright © 2018 Elsevier B.V. All rights reserved.

Engineering a Blood Vessel Network Module for Body-on-a-Chip Applications.

PubMed

Ryu, Hyunryul; Oh, Soojung; Lee, Hyun Jae; Lee, Jin Young; Lee, Hae Kwang; Jeon, Noo Li

2015-06-01

The blood circulatory system links all organs from one to another to support and maintain each organ's functions consistently. Therefore, blood vessels have been considered as a vital unit. Engineering perfusable functional blood vessels in vitro has been challenging due to difficulties in designing the connection between rigid macroscale tubes and fragile microscale ones. Here, we propose a generalizable method to engineer a "long" perfusable blood vessel network. To form millimeter-scale vessels, fibroblasts were co-cultured with human umbilical vein endothelial cells (HUVECs) in close proximity. In contrast to previous works, in which all cells were permanently placed within the device, we developed a novel method to culture paracrine factor secreting fibroblasts on an O-ring-shaped guide that can be transferred in and out. This approach affords flexibility in co-culture, where the effects of secreted factors can be decoupled. Using this, blood vessels with length up to 2 mm were successfully produced in a reproducible manner (>90%). Because the vessels form a perfusable network within the channel, simple links to inlets and outlets of the device allowed connections to the outside world. The robust and reproducible formation of in vitro engineered vessels can be used as a module to link various organ components as parts of future body-on-a-chip applications. © 2014 Society for Laboratory Automation and Screening.

In Vivo Evaluation of Active and Passive Physiological Control Systems for Rotary Left and Right Ventricular Assist Devices.

PubMed

Gregory, Shaun D; Stevens, Michael C; Pauls, Jo P; Schummy, Emma; Diab, Sara; Thomson, Bruce; Anderson, Ben; Tansley, Geoff; Salamonsen, Robert; Fraser, John F; Timms, Daniel

2016-09-01

Preventing ventricular suction and venous congestion through balancing flow rates and circulatory volumes with dual rotary ventricular assist devices (VADs) configured for biventricular support is clinically challenging due to their low preload and high afterload sensitivities relative to the natural heart. This study presents the in vivo evaluation of several physiological control systems, which aim to prevent ventricular suction and venous congestion. The control systems included a sensor-based, master/slave (MS) controller that altered left and right VAD speed based on pressure and flow; a sensor-less compliant inflow cannula (IC), which altered inlet resistance and, therefore, pump flow based on preload; a sensor-less compliant outflow cannula (OC) on the right VAD, which altered outlet resistance and thus pump flow based on afterload; and a combined controller, which incorporated the MS controller, compliant IC, and compliant OC. Each control system was evaluated in vivo under step increases in systemic (SVR ∼1400-2400 dyne/s/cm(5) ) and pulmonary (PVR ∼200-1000 dyne/s/cm(5) ) vascular resistances in four sheep supported by dual rotary VADs in a biventricular assist configuration. Constant speed support was also evaluated for comparison and resulted in suction events during all resistance increases and pulmonary congestion during SVR increases. The MS controller reduced suction events and prevented congestion through an initial sharp reduction in pump flow followed by a gradual return to baseline (5.0 L/min). The compliant IC prevented suction events; however, reduced pump flows and pulmonary congestion were noted during the SVR increase. The compliant OC maintained pump flow close to baseline (5.0 L/min) and prevented suction and congestion during PVR increases. The combined controller responded similarly to the MS controller to prevent suction and congestion events in all cases while providing a backup system in the event of single controller failure. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Low-Dimensional Models for Physiological Systems: Nonlinear Coupling of Gas and Liquid Flows

NASA Astrophysics Data System (ADS)

Staples, A. E.; Oran, E. S.; Boris, J. P.; Kailasanath, K.

2006-11-01

Current computational models of biological organisms focus on the details of a specific component of the organism. For example, very detailed models of the human heart, an aorta, a vein, or part of the respiratory or digestive system, are considered either independently from the rest of the body, or as interacting simply with other systems and components in the body. In actual biological organisms, these components and systems are strongly coupled and interact in complex, nonlinear ways leading to complicated global behavior. Here we describe a low-order computational model of two physiological systems, based loosely on a circulatory and respiratory system. Each system is represented as a one-dimensional fluid system with an interconnected series of mass sources, pumps, valves, and other network components, as appropriate, representing different physical organs and system components. Preliminary results from a first version of this model system are presented.

Non-circulatory fluid forces on porous bodies with application to panel flutter

NASA Astrophysics Data System (ADS)

Hajian, Rozhin; Jaworski, Justin W.

2017-11-01

The non-circulatory fluid forces acting on an oscillating porous panel or airfoil in uniform incompressible flow are derived from linearized potential theory. The fundamental integral equation for Holder-continuous porosity distributions is formulated and solved numerically for the special cases of non-porous and uniformly-porous panels with prescribed structural deformations. The new unsteady aerodynamic forces are then applied to aeroelastic stability predictions for porous panels or liners. Results from this analysis aim to form the basis of a complete unsteady aerodynamic theory for porous airfoils and their acoustic emissions based upon the unique attributes of natural fliers and swimmers.

Cardiorespiratory interactions in neural circulatory control in humans.

PubMed

Shamsuzzaman, A S; Somers, V K

2001-06-01

The reflex mechanisms and interactions described in this overview provide some explanation for the range of neural circulatory responses evident during changes in breathing. The effects described represent the integrated responses to activation of several reflex mechanisms, including peripheral and central chemoreflexes, arterial baroreflexes, pulmonary stretch receptors, and ventricular mechanoreceptors. These interactions occur on a dynamic basis and the transfer characteristics of any single interaction are, in all likelihood, also highly dynamic. Nevertheless, it is only by attempting to understand individual reflexes and their modulating influences that a more thorough understanding of the responses to complex phenomena such as hyperventilation, apnea, and obstructive sleep apnea can be better understood.

On the Estimation of Time Dependent Lift of a European Starling (Sturnus vulgaris) during Flapping Flight.

PubMed

Stalnov, Oksana; Ben-Gida, Hadar; Kirchhefer, Adam J; Guglielmo, Christopher G; Kopp, Gregory A; Liberzon, Alexander; Gurka, Roi

2015-01-01

We study the role of unsteady lift in the context of flapping wing bird flight. Both aerodynamicists and biologists have attempted to address this subject, yet it seems that the contribution of unsteady lift still holds many open questions. The current study deals with the estimation of unsteady aerodynamic forces on a freely flying bird through analysis of wingbeat kinematics and near wake flow measurements using time resolved particle image velocimetry. The aerodynamic forces are obtained through two approaches, the unsteady thin airfoil theory and using the momentum equation for viscous flows. The unsteady lift is comprised of circulatory and non-circulatory components. Both approaches are presented over the duration of wingbeat cycles. Using long-time sampling data, several wingbeat cycles have been analyzed in order to cover both the downstroke and upstroke phases. It appears that the unsteady lift varies over the wingbeat cycle emphasizing its contribution to the total lift and its role in power estimations. It is suggested that the circulatory lift component cannot assumed to be negligible and should be considered when estimating lift or power of birds in flapping motion.

2015 SCAI/ACC/HFSA/STS Clinical Expert Consensus Statement on the Use of Percutaneous Mechanical Circulatory Support Devices in Cardiovascular Care (Endorsed by the American Heart Association, the Cardiological Society of India, and Sociedad Latino Americana de Cardiologia Intervencion; Affirmation of Value by the Canadian Association of Interventional Cardiology-Association Canadienne de Cardiologie d'intervention).

PubMed

Rihal, Charanjit S; Naidu, Srihari S; Givertz, Michael M; Szeto, Wilson Y; Burke, James A; Kapur, Navin K; Kern, Morton; Garratt, Kirk N; Goldstein, James A; Dimas, Vivian; Tu, Thomas

2015-06-01

Although historically the intra-aortic balloon pump has been the only mechanical circulatory support device available to clinicians, a number of new devices have become commercially available and have entered clinical practice. These include axial flow pumps, such as Impella(®); left atrial to femoral artery bypass pumps, specifically the TandemHeart; and new devices for institution of extracorporeal membrane oxygenation. These devices differ significantly in their hemodynamic effects, insertion, monitoring, and clinical applicability. This document reviews the physiologic impact on the circulation of these devices and their use in specific clinical situations. These situations include patients undergoing high-risk percutaneous coronary intervention, those presenting with cardiogenic shock, and acute decompensated heart failure. Specialized uses for right-sided support and in pediatric populations are discussed and the clinical utility of mechanical circulatory support devices is reviewed, as are the American College of Cardiology/American Heart Association clinical practice guidelines. Copyright © 2015. Published by Elsevier Inc.