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Biomedical subjects

M Georgieff

Publications and source records attributed to M Georgieff.

At least 235 records · Page 13Linked to original sources
PubMed1988

Low-dose bradykinin infusion reduces endogenous glucose production in surgical patients.

The systemic effect of low-dose bradykinin infusion on total body glucose production and arterial substrate concentrations was examined during D5W infusion (1.0 mg/kg/min) in five normal-weight postsurgical subjects and compared to the response in four saline infused control patients, well matched for age, weight, and degree of postoperative stress. The primed-constant infusion of 6,6-d2-glucose was used to determine the rate of endogenous glucose production. After a basal period of 90 minutes, subjects in the study group were infused with bradykinin at increasing rates of 2.0 and 4.0 micrograms/kg/h, each infusion rate lasting for 90 minutes, whereas in controls corresponding amounts of saline were given. After 75 minutes of bradykinin, endogenous glucose production was significantly reduced as compared to basal values (1.63 +/- 0.21 mg/kg/min, P less than .0125 v 2.20 +/- 0.35 basal). This was accompanied by a significant reduction in arterial concentrations of glucose, lactate, pyruvate, and alanine. Corresponding concentrations of insulin, glucagon, glycerol, free fatty acids, and ketone bodies, as well as mean arterial blood pressure and heart rate was not affected by bradykinin. In the control group no significant changes in substrate and hormone concentrations, or the rate of glucose production were observed. The higher bradykinin infusion rate did not further affect substrate metabolism or systemic hemodynamics. These results demonstrate the inhibitory effect of low-dose bradykinin on glucose production in surgically stressed patients. The stimulation of hepatic prostaglandin synthesis by bradykinin may explain the results since prostaglandins are known to exert an inhibitory effect on hormone stimulated gluconeogenesis and glycogenolysis in liver tissue.

Adult↗
PubMed1987

Changes in energy expenditure and fat metabolism in rats infused with interleukin-1.

Metabolic alterations related to resting energy expenditure (REE) and fat metabolism have been noted during sepsis, and often depend on the causative agent and the stage and severity of the illness. We studied the effect of IL-1, the protein mediator of the 'acute phase' response during infection, on REE, respiratory quotient (RQ), and fat metabolism in male rats (210 g), who were infused over an 8-h period with (1-14C)-palmitate (PALM), (2-3H)-glycerol (GLY) and either saline or interleukin-1 (IL-1). At 7-8 h post infusion, the IL-1 group showed a significant increase in REE but no change in RQ. The IL-1 group also exhibited a significant decrease in serum free fatty acid (FFA) and an increase in FFA clearance. Free fatty acid flux, %PALM oxidation, serum (GLY), glycerol clearance, and glycerol flux (a measure of lipolytic rate) were not significantly different between the two groups. We conclude that IL-1 can mimic the increase in REE seen during infection; the increase in REE is not due to a selective increase in fat oxidation only, although the unchanged RQ and increased REE suggest that there is a proportional increase in net FFA oxidation.

Animals↗
PubMed1987

Interleukin 1, tumour necrosis factor-alpha (cachectin) and the pathogenesis of cancer cachexia.

Soluble proteins synthesized and released by phagocytic cells may be responsible for the protein and energy wasting frequently observed during catabolic states, including cancer cachexia. This hypothesis is based upon the observation that many of the hosts's metabolic responses to infection, inflammation, accidental trauma and some forms of cancer are remarkably similar. Anorexia and degradation of skeletal and connective tissue protein, as well as increases in hepatic protein synthesis and energy expenditure, can all be reproduced by the administration of activated macrophage products. During inflammatory states, including active tumour growth, increased production of some cytokines, including interleukin 1 and tumour necrosis factor-alpha (cachectin), have been observed. If these monokines serve as metabolic inducers, then efforts to block therapeutically the actions of macrophage-secreted substances may play a role in slowing the progression of tissue-wasting associated with catabolic states, particularly due to malignant tumours.

Animals↗
PubMed1987

The metabolic response to glycerol during parenteral nutrition.

The use of various nonprotein energy sources in parenteral nutrition regimens has been discussed for many years. Besides glucose, glycerol, xylitol, fructose and sorbitol are currently being used as water-soluble parenteral fuels. Despite the increasing frequency with which these glucose substitutes are being used, little information is available regarding the differences they evoke in host responses. All experimental evidence to date has shown glycerol to be equally effective in sparing body nitrogen as glucose when supplied in hypocaloric amounts. Results from studies in injured animals suggest that exogenously administered glycerol is a more potent inhibitor of fatty acid oxidation than glucose. Although results from human volunteers have been variable, glycerol administration after injury appears to markedly reduce fatty acid oxidation and ketogenesis, as well as increase hepatic glycogen. Glycerol toxicity appears to result only from its excessive administration, or when administered intraperitoneally or subcutaneously. Intravenous administration of hypocaloric quantities of glycerol alone or as a component of total parenteral nutrition is safe and effective.

Dose-Response Relationship, Drug↗
PubMed1987

[Metabolism-oriented postoperative nutritional therapy--possibilities and limits in the use of glucose and xylitol].

Carbohydrates and polyols are essential constituents of intravenous nutrition. In order to better understand the problems associated with the supply of energy sources, the physiology of enteral nutrition will be covered and compared with intravenous nutrition. This review article will deal with the metabolic actions of glucose and xylitol and derive therapeutical consequences for their intravenous use during different illnesses.

Alanine Transaminase↗
PubMed1987

[Intravenous feeding--possibilities and limits in the use of glucose and xylitol following trauma and infection, with special reference to liver metabolism].

Numerous side-effects of intravenously administered substrates have taught us that we have to reevaluate the dosages of the various substitutes of an intravenous regimen after trauma and during sepsis, whereby the limitation of glucose calories to approx. 3 g/kg B.W./day is of great metabolic importance. Additionally required calories can be provided either in the form of a lipid emulsion in a dosage of 1 to maximally 1.5 g/kg B.W./day and/or additionally xylitol in a dosage of max. 3 g/kg B.W./day.

Bacterial Infections↗
PubMed1986

Side effects of positive pressure ventilation on hepatic function and splanchnic circulation.

Positive pressure ventilation is associated with a reduction and redistribution of cardiac output. Splanchnic blood flow is decreased. Blood supply of the liver is reduced exceeding the fall in cardiac output. As a result oxygen transport to the mesenteric bed and liver is curtailed. There is a concomitant impairment of hepatic venous outflow. These hemodynamic changes may cause functional, structural and metabolic disturbances in organs whose blood supply arises from splanchnic circulation.

Bile Ducts↗
PubMed1985

Enteral tube feeding: state of the art.

We have provided an introduction and brief overview covering a new field of enteral nutrition and an important topic for research and patient care. Several advances have been developed and we must seize the opportunity to exploit new opportunities. Also, the endocrinology, biochemistry, and physiology of the gastrointestinal tract can be better understood in terms of response to enteral feeding. This "nutritional medicine" has potential to reduce the severity of illness, hasten recovery and agility, and restore quality to life.

Animals↗
PubMed1983

[Effect of different infusion regimens on the hormonal and metabolic reaction before, during and after cholecystectomy].

18 metabolically healthy female patients with cholelithiasis, who had to undergo cholecystectomy, were divided into 3 groups and studied for a 4-day period. Group I, n = 6, received beginning on the operationday 0,19 g/kg BW X h of a polyol-mixture-solution (Sorbitol/Xylitol 1:1) and 0,86 g 1-crystalline amino acids (AA)/kg BW X day. Group II, n = 6, received beginning 24 h preoperatively only 1,14 g 1-crystalline AA/kg BW X day. Group III, n = 6, received beginning 24 h preoperatively 0,07 g Xylitol/kg BW X h, 0,03 g Glucose/kg BW X h and 1,14 g 1-crystalline AA/kg BW X day. In this study we could demonstrate that the pre-, intra- and postoperative hormonal and metabolic response is strongly influenced by different infusion regimens. Only by the simultaneous infusion of carbohydrate together with AA during the preoperative period a significant drop of triiodothyronine can be avoided. The rise of insulin and cortisol in the early postoperative period is augmented by the infusion of carbohydrates together with AA. There was no difference in growth hormone response to surgery between group I-III. All 3 groups showed a continuous fall of cholesterol during the study period.

Cholecystectomy↗
PubMed1982

[Theory and practice of perioperative trauma-adapted parenteral feeding].

In this paper we introduce a new perioperative infusion regime. We will discuss problems associated with the water and electrolyte metabolism and show the influence of pre- and postoperative beginning of an intravenous nutrition support on metabolic and hormonal changes after trauma. We also will show the influence of hypercaloric and trauma-adapted nutritional support on hormonal, metabolic and liver-specific enzyme changes after trauma.

Amino Acids↗
PubMed1982

[Advantage of xylitol compared to glucose as an energy source during early postoperative parenteral feeding].

After a 5-day preoperative preparing period, 24 metabolically healthy patients, who had to undergo gastric resection, were fed postoperatively by hypocaloric total parenteral nutrition for a 5-day period. Group I, n = 13; received 0.11 g Xylitol/kg BW . h; Group II, n = 11, received 0.11 g Glucose/kg BW . h. Both groups received 1.71 g L-crystalline amino acids/kg BW . day. During the whole postoperative period, group II had significantly higher serum glucose and insulin levels. Due to the high postoperative insulin concentration in group II, free fatty acids, acetoacetate, beta-hydroxybutyrate and branched chained amino acids were significantly lower. The augmented release of muscle amino acids and the covering of a part of the energy expenditure by increased fatty acid oxidation in group I led to a higher postoperative synthesis rate of visceral proteins. From postoperative day 3 on transferrin and from postoperative day 6 on albumin and total protein were significantly higher in group I. This study could demonstrate that due to its special role in the intermediary metabolism during the postoperative period xylitol leads to a significantly higher regeneration rate of visceral proteins compared to glucose during total parenteral nutrition.

Adult↗
PubMed1982

[Regulation of ketone body levels before and following elective surgical operations during different intravenous feedings].

44 patients who had to undergo gastric resection and 28 patients who had to undergo cholecystectomy were divided into 4 groups each. Each group received parenterally a different energy source and calorie-nitrogen ratio. We intended to investigate the influence of different intravenous regimens on pre- and postoperative acetoacetate and beta-hydroxybutyrate levels. Patients undergoing gastric resection who received 0.36 g glucose/kg BW x h together with 1.14 g/kg BW x day 1-crystalline amino acids had the lowest postoperative ketone body concentration. A comparable group who received 0.36 g/kg BW x day of a carbohydrate-mixture solution consisting of glucose-fructose and xylitol in a proportion of 1:1:1 had significantly higher ketone bodies. The comparison of glucose with xylitol in a hypocaloric dosage of 0.11 g/kg BW x h led to a physiologic ketosis only in the group with xylitol as energy source from postoperative day 2 on. In patients undergoing cholecystectomy, the sole infusion of amino acids in a dosage of 1.14 g/kg BW x h led to the highest ketone bodies from the operation day on. The intravenous infusion of a polyol-mixture solution containing xylitol and sorbitol in a relation of 1:1 in a dosage of 4.2 g/kg BW x day led to the lowest ketone body production. The infusion of a polyol-mixture solution in a dosage of 2 g/kg BW x day enabled the development of a physiologic ketosis. In this study we could demonstrate that the infusion of xylitol or a polyol-mixture solution in a dosage of 2-3 g/kg BW x day after elective surgery enables the development of physiologic ketosis.

3-Hydroxybutyric Acid↗
PubMed1982

[Importance of lipid metabolism in the overcoming of trauma].

We studied the pre- and postoperative lipid metabolism in 24 metabolically healthy surgical patients who had to undergo gastric resection during intravenous substitional infusion. Group I, n = 10, received 0,36 g/kg Bw x h of a carbohydrate mixture solution together with 1.14 g L-crystalline amino acids/kg Bw . day. Group II, n = 11, received 0.11 g Glucose/kg Bw x h; group group III, n = 13, received 0.11 g Xylitol/kg Bw x h. Both groups II and III received 1.71 g L-crystalline amino acids/kg Bw x day. After the preoperative infusion period the free fatty acids fall significantly in all groups. beta-hydroxybutyrate falls on the operation-day in all groups also with no significance. Postoperatively the free fatty acid levels remain significantly reduced in all groups. From postoperative day 1 to 5 the FFA levels in group III are significantly higher compared with group I and II. From postoperative day 2 on beta-hydroxybutyrate levels rise in all groups. From postoperative day 1 on beta-hydroxybutyrate and acetacetate levels in group III are significantly higher compared with group I and II. In conclusion the hypocaloric postoperative infusion of xylitol directs fat metabolism to reasonable physiologic pathways. A short term postoperative hypercaloric nutrition seems inadequate in patients with normal body weight.

Acetoacetates↗
PubMed1982

[Anesthesia in patients with hormonal and metabolic diseases].

In this paper the pathophysiology and clinical symptoms of the most frequent hormonal and metabolic disorders are discussed with regard to their importance for the anaesthesiologist. Special recommendations for various anaesthesiological procedures are given. The disorders in particular discussed are diabetes mellitus, disorders of the thyroid and the adrenal cortex and phaeochromocytoma.

Adrenal Gland Diseases↗