Effects of hypoxia and hypercapnia on whole body release and clearance of choline

1995 ◽  
Vol 268 (6) ◽  
pp. R1520-R1525 ◽  
Author(s):  
D. J. Jenden ◽  
O. U. Scremin
Keyword(s):  
Simple Model ◽  
Intravenous Infusion ◽  
Respiratory Acidosis ◽  
Whole Body ◽  
Body Balance ◽  
Arterial Blood ◽  
Individual Contributions ◽  
Per Se ◽  
The Individual

We have recently demonstrated an increase in arterial blood choline (Ch) concentration in normocapnic hypoxia and apnea. This could be due to enhanced release of free Ch from tissues, to decreased Ch clearance, or both. The present investigations was undertaken to determine the individual contributions of these processes to the whole body balance of Ch, using an intravenous infusion of tracer quantities of [2H4]Ch to assess the bidirectional flux between the central pool and peripheral pools. Rats were subjected to normocapnic hypoxia or hypercapnia; release and clearance of Ch were calculated using a simple model. Hypoxia caused an increase in Ch production and a decrease in Ch clearance. At severe levels of hypoxia, Ch clearance was essentially zero. Hypoxia was attended by progressive acidosis that was related to the magnitude of the hypoxic challenge. To determine the possible effects of acidosis per se on the variables measured, respiratory acidosis with normoxia was provoked by controlled administration of CO2. Under these conditions, parallel decreases in Ch production and Ch clearance were observed.

Dissociation between skeletal muscle microvascular Po2and hypoxia-induced microvascular inflammation

2003 ◽  
Vol 94 (6) ◽  
pp. 2323-2329 ◽  
Author(s):  
Sidharth Shah ◽  
Julie Allen ◽  
John G. Wood ◽  
Norberto C. Gonzalez
Keyword(s):  
Blood Flow ◽  
Microvascular Blood Flow ◽  
Phosphorescence Quenching ◽  
Arterial Blood ◽  
Anesthetized Rats ◽  
Systemic Hypoxia ◽  
Individual Contributions ◽  
Microvascular Inflammation ◽  
Quenching Method ◽  
The Individual

Systemic hypoxia (SHx) produces microvascular inflammation in mesenteric, cremasteric, and pial microcirculations. In anesthetized rats, SHx lowers arterial blood pressure (MABP), which may alter microvascular blood flow and microvascular Po2(PmO2) and influence SHx-induced leukocyte-endothelial adherence (LEA). These experiments attempted to determine the individual contributions of the decreases in PmO2, venular blood flow and shear rate, and MABP to the hypoxia-induced increase in LEA. Cremaster microcirculation of anesthetized rats was visualized by intravital microscopy. PmO2was measured by a phosphorescence-quenching method. SHx [inspired Po2of 70 Torr for 10 min, MABP of 65 ± 3 mmHg, arterial Po2(PaO2) of 33 ± 1 Torr] and cremaster ischemia (MABP of 111 ± 7 mmHg, PaO2of 86 ± 3 Torr) produced similar PmO2: 7 ± 2 and 6 ± 2 Torr, respectively. However, LEA increased only in SHx (1.9 ± 0.9 vs. 11.2 ± 1.1 leukocytes/100 μm, control vs. SHx, P < 0.05). Phentolamine-induced hypotension (MABP of 55 ± 4 mmHg) in normoxia lowered PmO2to 26 ± 6 Torr but did not increase LEA. Cremaster equilibration with 95% N2-5% CO2during air breathing (PaO2of 80 ± 1 Torr) lowered PmO2to 6 ± 1 Torr but did not increase LEA. On the other hand, when cremaster PmO2was maintained at 60–70 Torr during SHx (PaO2of 35 ± 1 Torr), LEA increased from 2.1 ± 1.1 to 11.1 ± 1.5 leukocytes/100 μm ( P < 0.05). The results show a dissociation between PmO2and LEA and support the idea that SHx results in the release of a mediator responsible for the inflammatory response.

Influence of chronic metabolic acid-base disorders on the acute CO2 titration curve

1983 ◽  
Vol 55 (4) ◽  
pp. 1187-1195 ◽  
Author(s):  
N. E. Madias ◽  
H. J. Adrogue
Keyword(s):  
Titration Curve ◽  
Respiratory Acidosis ◽  
Whole Body ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Hydrogen Ion Concentration ◽  
Plasma Bicarbonate ◽  
Arterial Blood ◽  
Acid Base Equilibrium ◽  
Body Response

Previous studies from this laboratory have characterized the “whole-body” response to acute hypercapnia in normal dog and humans. A more recent investigation has demonstrated that this response is markedly altered by graded degrees of chronic respiratory acidosis. The present studies were carried out to assess the influence, if any, of chronic metabolic acid-base disturbances on the acute CO2 titration curve in the dog. To this purpose we first produced a broad range of chronic plasma bicarbonate concentration of metabolic nature. Metabolic acidosis (n = 14) was produced by prolonged HCl-feeding and metabolic alkalosis (n = 11) by diuretics and a chloride-free diet. Animals with normal acid-base status (n = 4) were also studied. After the establishment of a chronic steady state of acid-base equilibrium, we then performed an acute CO2 titration of the unanesthetized dogs within a large environmental chamber. Three levels of inspired CO2 fraction (FICO2) were employed ranging from 4 to 15%. The results indicate that chronic metabolic acid-base disturbances exert a dramatic influence on the whole-body response to acute hypercapnia. The acute change in plasma bicarbonate for a given change in partial pressure of CO2 in arterial blood (PaCO2) or plasma pH decreases as a function of the chronic level of plasma bicarbonate concentration. Yet the ability of the organism to defend plasma hydrogen ion concentration is progressively strengthened as the chronic level of plasma bicarbonate increases.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effect of acute acid-base disturbances on ErbB1/2 tyrosine phosphorylation in rabbit renal proximal tubules

2013 ◽  
Vol 305 (12) ◽  
pp. F1747-F1764 ◽  
Author(s):  
Lara A. Skelton ◽  
Walter F. Boron
Keyword(s):  
Metabolic Alkalosis ◽  
Kinase Inhibitor ◽  
Respiratory Acidosis ◽  
Respiratory Alkalosis ◽  
Proximal Tubules ◽  
Whole Body ◽  
Ph Homeostasis ◽  
Acid Base ◽  
Major Site ◽  
The Individual

The renal proximal tubule (PT) is a major site for maintaining whole body pH homeostasis and is responsible for reabsorbing ∼80% of filtered HCO3−, the major plasma buffer, into the blood. The PT adapts its rate of HCO3− reabsorption ( JHCO3−) in response to acute acid-base disturbances. Our laboratory previously showed that single isolated perfused PTs adapt JHCO3− in response to isolated changes in basolateral (i.e., blood side) CO2 and HCO3− concentrations but, surprisingly, not to pH. The response to CO2 concentration can be blocked by the ErbB family tyrosine kinase inhibitor PD-168393. In the present study, we exposed enriched rabbit PT suspensions to five acute acid-base disturbances for 5 and 20 min using a panel of phosphotyrosine (pY)-specific antibodies to determine the influence of each disturbance on pan-pY, ErbB1-specific pY (four sites), and ErbB2-specific pY (two sites). We found that each acid-base treatment generated a distinct temporal pY pattern. For example, the summated responses of the individual ErbB1/2-pY sites to each disturbance showed that metabolic acidosis (normal CO2 concentration and reduced HCO3− concentration) produced a transient summated pY decrease (5 vs. 20 min), whereas metabolic alkalosis produced a transient increase. Respiratory acidosis (normal HCO3− concentration and elevated CO2 concentration) had little effect on summated pY at 5 min but produced an elevation at 20 min, whereas respiratory alkalosis produced a reduction at 20 min. Our data show that ErbB1 and ErbB2 in the PT respond to acute acid-base disturbances, consistent with the hypothesis that they are part of the signaling cascade.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

A Handbook to Eddic Poetry: Myths and Legends of Early Scandinavia, ed. Carolyne Larrington, Judy Quinn, and Brittany Schorn. Cambridge: Cambridge University Press, 2016, xii, 413 pp., 12 b/w ill.

Mediaevistik ◽  
2018 ◽  
Vol 31 (1) ◽  
pp. 366-366
Author(s):  
Albrecht Classen
Keyword(s):  
Old Norse ◽  
Entire Volume ◽  
Cambridge University ◽  
Critical Studies ◽  
Individual Contributions ◽  
The Many ◽  
The Individual ◽  
Made In ◽  
Scandinavian Literature

Eddic poetry constitutes one of the most important genres in Old Norse or Scandinavian literature and has been studied since the earliest time of modern-day philology. The progress we have made in that field is impressive, considering the many excellent editions and translations, not to mention the countless critical studies in monographs and articles. Nevertheless, there is always a great need to revisit, to summarize, to review, and to digest the knowledge gained so far. The present handbook intends to address all those goals and does so, to spell it out right away, exceedingly well. But in contrast to traditional concepts, the individual contributions constitute fully developed critical article, each with a specialized topic elucidating it as comprehensively as possible, and concluding with a section of notes. Those are kept very brief, but the volume rounds it all off with an inclusive, comprehensive bibliography. And there is also a very useful index at the end. At the beginning, we find, following the table of contents, a list of the contributors, unfortunately without emails, a list of translations and abbreviations of the titles of Eddic poems in the Codex Regius and then elsewhere, and a very insightful and pleasant introduction by Carolyne Larrington. She briefly introduces the genre and then summarizes the essential points made by the individual authors. The entire volume is based on the Eddic Network established by the three editors in 2012, and on two workshops held at St. John’s College, Oxford in 2013 and 2014.

Employee Surveys and Sensing

2020 ◽  
Keyword(s):  
Organizational Performance ◽  
Employee Engagement ◽  
Computational Linguistics ◽  
Full Range ◽  
Organization Culture ◽  
Employee Survey ◽  
Passive Data ◽  
Individual Contributions ◽  
Action Taking ◽  
The Individual

This volume comprises 27 chapters focused on the design and execution of employee survey programs. These chapters reflect the latest advances in technology and analytics and a pervasive emphasis on driving organizational performance and effectiveness. The individual chapters represent the full range of survey-related topics, including design, administration, analysis, feedback, and action-taking. The latest methodological trends and capabilities are discussed including computational linguistics, applications of artificial intelligence, and the use of qualitative methods such as focus groups. Extending beyond traditional employee surveys, contributions include the role of passive data collection as an alternative or supplement in a comprehensive employee listening system. Unique contextual factors are discussed including the use of surveys in a unionized environment. Individual contributions also reflect increasing stakeholder concerns for the protection of privacy among other ethical considerations. Finally, significant clarifications to the literature are provided on the use of surveys for measuring organization culture, strategic climate, and employee engagement.

Knowledge First

2017 ◽  
Author(s):  
J. Adam Carter ◽  
Emma C. Gordon ◽  
Benjamin W. Jarvis
Keyword(s):  
Philosophy Of Mind ◽  
Theoretical Background ◽  
Contemporary Research ◽  
Timothy Williamson ◽  
Research Themes ◽  
New Directions ◽  
Individual Contributions ◽  
The Individual

In this introductory chapter, the volume’s editors provide a theoretical background to the volume’s topic and a brief overview of the papers included. The chapter is divided into five parts: Section 1 explains the main contours of the knowledge-first approach, as it was initially advanced by Timothy Williamson in Knowledge and its Limits. In Sections 2–3, some of the key philosophical motivations for the knowledge-first approach are reviewed, and several key contemporary research themes associated with this approach in epistemology, the philosophy of mind and elsewhere are outlined and briefly discussed. The volume’s papers are divided into two broad categories: foundational issues and applications and new directions. Section 4 discusses briefly the scope and aim of the volume as the editors have conceived it, and Section 5 offers an overview of each of the individual contributions in the volume.

scholarly journals Causes, Effects and Methods of Monitoring Gas Exchange Disturbances during Equine General Anaesthesia

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2049
Author(s):  
Elżbieta Stefanik ◽  
Olga Drewnowska ◽  
Barbara Lisowska ◽  
Bernard Turek
Keyword(s):  
Gas Exchange ◽  
General Anaesthesia ◽  
Near Infrared ◽  
Respiratory Acidosis ◽  
Monitoring Methods ◽  
Arterial Blood Gas ◽  
Complementary Method ◽  
Arterial Blood ◽  
Operative Complications ◽  
Post Operative Complications

Horses, due to their unique anatomy and physiology, are particularly prone to intraoperative cardiopulmonary disorders. In dorsally recumbent horses, chest wall movement is restricted and the lungs are compressed by the abdominal organs, leading to the collapse of the alveoli. This results in hypoventilation, leading to hypercapnia and respiratory acidosis as well as impaired tissue oxygen supply (hypoxia). The most common mechanisms disturbing gas exchange are hypoventilation, atelectasis, ventilation–perfusion (V/Q) mismatch and shunt. Gas exchange disturbances are considered to be an important factor contributing to the high anaesthetic mortality rate and numerous post-anaesthetic side effects. Current monitoring methods, such as a pulse oximetry, capnography, arterial blood gas measurements and spirometry, may not be sufficient by themselves, and only in combination with each other can they provide extensive information about the condition of the patient. A new, promising, complementary method is near-infrared spectroscopy (NIRS). The purpose of this article is to review the negative effect of general anaesthesia on the gas exchange in horses and describe the post-operative complications resulting from it. Understanding the changes that occur during general anaesthesia and the factors that affect them, as well as improving gas monitoring techniques, can improve the post-aesthetic survival rate and minimize post-operative complications.

scholarly journals Biomechanical Aspects of the Foot Arch, Body Balance and Body Weight Composition of Boys Training Football

2021 ◽  
Vol 18 (9) ◽  
pp. 5017
Author(s):  
Joanna M. Bukowska ◽  
Małgorzata Jekiełek ◽  
Dariusz Kruczkowski ◽  
Tadeusz Ambroży ◽  
Jarosław Jaszczur-Nowicki
Keyword(s):  
Body Composition ◽  
Body Height ◽  
Study Groups ◽  
The Body ◽  
Whole Body ◽  
Training Methods ◽  
Training Experience ◽  
Mean Values ◽  
Significance Level ◽  
Body Balance

Background: The aim of the study is to assess the body balance and podological parameters and body composition of young footballers in the context of the control of football training. Methods: The study examined the distribution of the pressure of the part of the foot on the ground, the arch of the foot, and the analysis of the body composition of the boys. The pressure center for both feet and the whole body was also examined. The study involved 90 youth footballers from Olsztyn and Barczewo in three age groups: 8–10 years, 11–13 years old, and 14–16 years. The study used the Inbody 270 body composition analyzer and the EPSR1, a mat that measures the pressure distribution of the feet on the ground. Results: The results showed statistically significant differences in almost every case for each area of the foot between the groups of the examined boys. The most significant differences were observed for the metatarsal area and the left heel. In the case of stabilization of the whole body, statistically significant differences were noted between all study groups. In the case of the body composition parameters, in the examined boys, a coherent direction of changes was noticed for most of them. The relationships and correlations between the examined parameters were also investigated. The significance level in the study was set at p < 0.05. Conclusions: Under the training rigor, a statistically significant increase in stability was observed with age. The total length of the longitudinal arch of both feet of the examined boys showed a tendency to flatten in direct proportion to the age of the examined boys. Mean values of the body composition parameters reflect changes with the ontogenetic development, basic somatic parameters (body height and weight) and training experience, and thus with the intensity and volume of training. This indicates a correct training process that does not interfere with the proper development of the body in terms of tissue and biochemical composition.

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