scholarly journals The Influence of Biological and Technical Factors on the Variability of Global and Regional Brain Metabolism of 2-[18F]Fluoro-2-Deoxy-D-Glucose

1992 ◽  
Vol 12 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Edwaldo E. Camargo ◽  
Zsolt Szabo ◽  
Jonathan M. Links ◽  
Samuel Sostre ◽  
Robert F. Dannals ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Blood Glucose Concentration ◽  
Temporal Cortex ◽  
Peak Time ◽  
Operational Equation ◽  
Complex Functions ◽  
Coefficients Of Variations ◽  
Technical Factors ◽  
The Individual ◽  
The Brain

This study investigated the influence of biological and technical factors on variations of global and regional cerebral metabolic rate of glucose (CMRglc) measured with 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG). Twelve male volunteers (22–40 years) were investigated on three or four occasions for a total of 42 studies. We calculated the variance/covariance of the following parameters: CMRglc, six parameters of the blood clearance of [18F]FDG, hour of injection, peak time of blood radioactivity, and six components of the operational equation (nonradioactive blood glucose concentration, brain radioactivity, two integrals, numerator, and denominator). There was correlation among these six components, except for nonradioactive blood glucose. However, the correlation between the CMRglc and the individual components of the operational equation was poor. The inter- and intrapersonal CMRglc coefficients of variations were 13.8 and 7.1%, respectively. In contrast, coefficients of variations of the numerator and denominator of the operational equation were 34.6 and 32.6%, respectively, and were always in the same direction. No correlation was found between CMRglc and the technical factors in the numerator and denominator of the operational equation. Factor analysis disclosed that a single factor was responsible for 70% of the variance. This factor included caudate, putamen, thalamus, frontal cortex, temporal cortex, and cingulate gyrus. These structures are involved with multiple complex functions, from autonomic motor control to behavior and emotions. The intrinsic metabolic variability of these structures, along with the basal metabolic processes that are continuously going on in the brain, may be the best explanation for the variance encountered in our investigation.

Hypoglycaemia in the treatment of diabetes mellitus

2011 ◽  
pp. 1849-1861
Author(s):  
Pratik Choudhary ◽  
Stephanie A. Amiel
Keyword(s):  
Diabetes Mellitus ◽  
Blood Glucose ◽  
Blood Glucose Concentration ◽  
Cerebral Metabolism ◽  
Chronic Complications ◽  
Glucose Levels ◽  
Patients With Diabetes ◽  
Treatment Of Diabetes ◽  
Clinically Significant ◽  
The Brain

Hypoglycaemia (low blood glucose concentration) is the most important acute complication of the pharmacological treatment of diabetes mellitus. Low blood glucose impairs brain (and, potentially, cardiac) function. The brain has minimal endogenous stores of energy, with small amounts of glycogen in astroglial cells. The brain is therefore largely dependent on circulating glucose as the substrate to fuel cerebral metabolism and support cognitive performance. If blood glucose levels fall sufficiently, cognitive dysfunction is inevitable. In health, efficient glucose sensing and counterregulatory mechanisms exist to prevent clinically significant hypoglycaemia. These are impaired by diabetes and by its therapies. Patients with diabetes rank fear of hypoglycaemia as highly as fear of chronic complications such as nephropathy or retinopathy (1). Fear of hypoglycaemia, hypoglycaemia itself and attempts to avoid hypoglycaemia limit the degree to which glycaemic control can be intensified to reduce the risk of chronic complications of diabetes both for type 1 and type 2 diabetes.

scholarly journals THE EFFECT OF HYPERGLYCEMIA ON HYPOTHALAMIC GOLD UPTAKE AND HYPERPHAGIA IN GOLDTHIOGLUCOSE-TREATED MICE

1965 ◽  
Vol 121 (3) ◽  
pp. 403-413 ◽  
Author(s):  
P. Michael Edelman ◽  
Irving L. Schwartz ◽  
Eugene P. Cronkite ◽  
George Brecher ◽  
Linda Livingston
Keyword(s):  
Blood Glucose ◽  
Intravenous Injection ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Hypothalamic Lesion ◽  
Gold Deposition ◽  
Gold Content ◽  
Single Intravenous Injection ◽  
Control Brain ◽  
The Brain

The accumulation of gold in the hypothalamus and the development of hyperphagia and obesity were studied in mice given a single intravenous injection of goldthioglucose at various levels of blood glucose concentration. It was found that the glucose concentration prevailing at the time of goldthioglucose injection was correlated directly with the level of free and bound goldthioglucose in the blood 3 minutes later, with the hypothalamic uptake of gold, with the extent of the hypothalamic lesion, and with the severity of the subsequent hyperphagia and obesity. Hyperglycemia was associated with an increased gold deposition throughout the brain. A gold content of 88 ± 12 µg/mg wet tissue in the hypothalamus of fasted animals was associated with clearcut lesions in all animals studied, whereas a similar gold content in the control brain lobes of hyperglycemic animals was not associated with lesions in any animal. This finding indicates that some regions in the brain (e.g. the ventral hypothalamus) are more susceptible than others to damage by goldthioglucose.

Slow postmeal walking reduces postprandial glycemia in middle-aged women

2009 ◽  
Vol 34 (6) ◽  
pp. 1087-1092 ◽  
Author(s):  
Håvard Nygaard ◽  
Sissel Erland Tomten ◽  
Arne Torbjørn Høstmark
Keyword(s):  
Blood Glucose ◽  
Glucose Concentration ◽  
Blood Glucose Concentration ◽  
Negative Relationship ◽  
Postprandial Blood Glucose ◽  
Moderate Intensity ◽  
Glucose Response ◽  
Postprandial Glycemia ◽  
Blood Glucose Response ◽  
The Individual

Postprandial blood glucose concentration is a risk factor for the development of cardiovascular diseases and diabetes, even at states well below hyperglycemic levels. A previous study has shown that postmeal exercise of moderate intensity blunts the blood glucose increase after carbohydrate intake (Høstmark et al. Prev. Med. 42(5): 369–371). The objective of the present study was to examine whether even postmeal slow walking would have a similar effect. Fourteen healthy women aged >50 years participated in 3 experiments in a random crossover design: after a carbohydrate-rich meal, either they were seated (control experiment) or they performed slow postmeal walking for 15 min (W15) or 40 min (W40). Blood glucose concentration was determined prior to the meal (fasting), and at 11 time points throughout each experiment. The W15 trial lowered the blood glucose values during walking and delayed the peak blood glucose value (p = 0.003). In W40, the postmeal blood glucose increase during walking was blunted, the peak glucose value was delayed (p = 0.001), and the incremental area under the 2-h blood glucose curve (IAUC) was reduced (p = 0.014). There was a negative relationship between IAUC and walking time (p = 0.016). The individual reducing effect of walking on IAUC correlated strongly with IAUC on the control day (p < 0.001). We conclude that even slow postmeal walking can reduce the blood glucose response to a carbohydrate-rich meal. The magnitude of this effect seems to be related to the duration of walking and to the magnitude of the postprandial blood glucose response when resting after a carbohydrate-rich meal.

Effects of Epinephrine on Metabolism of Glucose of Normal Dogs

1958 ◽  
Vol 194 (2) ◽  
pp. 327-332 ◽  
Author(s):  
Sherman R. Dickman ◽  
Walter G. Wiest ◽  
Kristen Eik-Nes
Keyword(s):  
Blood Glucose ◽  
Specific Activity ◽  
Blood Glucose Concentration ◽  
Femoral Vein ◽  
Concomitant Administration ◽  
Treated Group ◽  
Dual Effect ◽  
Anesthetized Dogs ◽  
Lactate Levels ◽  
The Individual

Following the intravenous administration of a tracer dose of C14 glucose, nonradioactive glucose was infused in normal, anesthetized dogs over a 2-hour period with and without the concomitant administration of epinephrine. Blood samples were obtained from the portal vein, hepatic vein, femoral artery and femoral vein at various periods after the start of the infusion. The blood glucose concentration was higher in the epinephrine-treated animals than in the controls and blood glucose radioactivity remained at consistently higher levels in the former group. Blood glucose specific activity, however, dropped faster and attained lower values in the controls. Blood lactate levels were higher in the epinephrine-treated animals. The individual and cumulative specific activities of expired CO2 were appreciably lower in the epinephrine-treated group. The results are interpreted as demonstrating a dual effect of epinephrine; decrease in glucose uptake by tissues and an increase in lactate entry into the blood.

Effect on blood glucose concentration of changes in availability of glucose to the brain

1963 ◽  
Vol 204 (6) ◽  
pp. 1127-1132 ◽  
Author(s):  
Kazuki Sakata ◽  
Shigeo Hayano ◽  
Henry A. Sloviter
Keyword(s):  
Blood Glucose ◽  
Glucose Concentration ◽  
Internal Carotid ◽  
Glucose Solution ◽  
Blood Glucose Concentration ◽  
Systemic Blood ◽  
Significant Difference ◽  
Sympathetic Nervous ◽  
The Brain ◽  
Glucose Curve

In the unanesthetized rabbit, systemic blood glucose concentration was measured periodically during the course of a slow, continuous infusion of glucose solution via the internal carotid artery. Under conditions otherwise identical, the same experiment was performed in the same rabbit, but the infusion was intravenous. In 7 of 14 such pairs of experiments, the curve of glucose concentration versus time was significantly lower for the intracarotid experiment and in the other seven cases there was no significant difference between the two curves. These results suggest that the brain responds to the increased concentration of glucose of its environment and by some mechanism acts to return it toward normal. Experiments were done in the same way with 2-deoxy-d-glucose, a substance which produces a cellular glucopenia. Of seven pairs of experiments, the systemic blood glucose curve was markedly higher in intracarotid infusion in three cases, moderately higher in two cases, and not significantly different in two cases from the curve for the intravenous infusion. These results suggest that the brain responds to decreased availability of glucose and acts, by way of the sympathetic nervous system, to raise the blood glucose concentration.

Fit Vs Faint: Assessing Work Causation in “Idiopathic Fall” Cases

2014 ◽  
Vol 19 (5) ◽  
pp. 3-12
Author(s):  
Lorne Direnfeld ◽  
David B. Torrey ◽  
Jim Black ◽  
LuAnn Haley ◽  
Christopher R. Brigham
Keyword(s):  
Blood Flow ◽  
Electrical Activity ◽  
Loss Of Consciousness ◽  
Brain Electrical Activity ◽  
Medical Terminology ◽  
Scientific Analysis ◽  
Medical Causation ◽  
The Individual ◽  
The Brain ◽  
Current Science

Abstract When an individual falls due to a nonwork-related episode of dizziness, hits their head and sustains injury, do workers’ compensation laws consider such injuries to be compensable? Bearing in mind that each state makes its own laws, the answer depends on what caused the loss of consciousness, and the second asks specifically what happened in the fall that caused the injury? The first question speaks to medical causation, which applies scientific analysis to determine the cause of the problem. The second question addresses legal causation: Under what factual circumstances are injuries of this type potentially covered under the law? Much nuance attends this analysis. The authors discuss idiopathic falls, which in this context means “unique to the individual” as opposed to “of unknown cause,” which is the familiar medical terminology. The article presents three detailed case studies that describe falls that had their genesis in episodes of loss of consciousness, followed by analyses by lawyer or judge authors who address the issue of compensability, including three scenarios from Arizona, California, and Pennsylvania. A medical (scientific) analysis must be thorough and must determine the facts regarding the fall and what occurred: Was the fall due to a fit (eg, a seizure with loss of consciousness attributable to anormal brain electrical activity) or a faint (eg, loss of consciousness attributable to a decrease in blood flow to the brain? The evaluator should be able to fully explain the basis for the conclusions, including references to current science.

An Approach to diabetic ketoacidosis in an emergency setting.

2020 ◽  
Vol 15 ◽  
Author(s):  
Dario Pitocco ◽  
Mauro Di Leo ◽  
Linda Tartaglione ◽  
Emanuele Gaetano Rizzo ◽  
Salvatore Caputo ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Type 1 Diabetes ◽  
Blood Glucose ◽  
Diabetic Ketoacidosis ◽  
Blood Glucose Concentration ◽  
Diabetic Complication ◽  
Emergency Setting ◽  
Online Activity

Background: Diabetic Ketoacidosis (DKA) is one of the most commonly encountered diabetic complication emergencies. It typically affects people with type 1 diabetes at the onset of the disease. It can also affect people with type 2 diabetes, although this is uncommon. Methods: Research and online content related to diabetes online activity is reviewed. DKA is caused by a relative or absolute deficiency of insulin and elevated levels of counter regulatory hormones. Results: Goals of therapy are to correct dehydration, acidosis and to reverse ketosis, gradually restoring blood glucose concentration to near normal. Conclusion: Furthermore it is essential to monitor potential complications of DKA and if necessary, to treat them and any precipitating events.

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