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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sepsis is a major catabolic insult resulting in modifications in carbohydrate and fat energy metabolism, and leading to increased muscle breakdown and nitrogen loss. Insulin resistance, which develops in sepsis, decreases glucose utilization, but plasma insulin levels are sufficiently elevated to prevent lipolysis, resulting in a further energy deficit. The availability of fuels in sepsis is therefore limited, and the body resorts to muscle breakdown, gluconeogenesis, and amino acid oxidation for energy supply. Previous work has not defined, however, the exact alterations in amino acid metabolism. Therefore, the following studies were undertaken. Blood samples were drawn from fifteen patients in whom the diagnosis of sepsis was clinically established; the samples were analyzed for amino acid, beta-hydroxyphenylethanolamines, glucose, insulin and glucagon concentrations. The plasma amino acid pattern observed was characterized by an increase in total amino acid content, due mainly to high levels of the aromatic amino acids (phenylalanine and tyrosine) and the sulfur-containing amino acids (taurine, cystine and methionine). Alanine, aspartic acid, glutamic acid and proline were also elevated, but to a lesser degree. The branched chain amino acids (valine, leucine and isoleucine) were within normal limits, as were glycine, serine, threonine, lysine, histidine and tryptophan. Those patients who did not survive sepsis had higher levels of aromatic and sulfur-containing amino acids as compared to those patients surviving sepsis. On the other hand, those patients surviving sepsis had higher levels of alanine and the branched chain amino acids. In a second group of five patients with overwhelming sepsis accompanied by a state of metabolic encephalopathy, a parenteral nutrition solution consisting of 23% dextrose, and an amino acid formulation enriched with branched chain amino acids was administered. In these five patients, normalization of the plasma amino acid pattern and reversal of encephalopathy was observed. The following sequence of events may be postulated: The septic patient develops insulin resistance in the peripheral tissues, primarily muscle, while the adipose tissue is much less affected. The insulin resistance and the inability to utilize fat leads to increased muscle proteolysis. Muscle breakdown results in release into the blood of enormous amounts of various amino acids; the muscle itself is able to oxidize the branched chain amino acids, supplying the muscles' own energy requirements and alanine for gluconeogenesis. The extensive muscle proteolysis coupled with relative hepatic insufficiency occurring early in sepsis results in the appearance in the plasma of high levels of most of the amino acids present in muscle, particularly the aromatic and the sulfur-containing amino acids. The outcome of patients with sepsis might be positively affected by combined therapy with glucose, insulin and branched chain amino acids.
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PMID:Amino acid derangements in patients with sepsis: treatment with branched chain amino acid rich infusions. 9 98

Preoperative and serial postoperative clinical, cardiovascular, physiologic, and metabolic studies were carried out on 86 patients undergoing coronary artery bypass surgery (CABG); and 48 patients undergoing abdominal general surgical procedures (GSEL). Multivariable statistical analysis of these data showed the patients to be in different physiologic states and to manifest several types of recovery trajectories that could not be discerned on clinical grounds alone. The CABG patients followed one of three types of cardiogenic recovery trajectories. In contrast, GSEL patients show a normal recovery trajectory different from all CABG types. When sepsis develops, and exaggerated stress response (A state) occurs, with increased oxygen consumption and a pattern of amino acids, fat, and glucose breakdown products, which is heightened but similar to the response of nonseptic GSEL patients. With progression of sepsis severity, an unbalanced hyperdynamic recovery trajectory (B state) develops in which a decrease in oxygen consumption is associated with increases in the aromatic amino acids tyrosine, tryptophane, and phenylalanine; and decreases in the branched-chain amino acids, leucine and isoleucine. Triglycerides rise as keto acids fall, but both lactate and pyruvate rise. Glucagon is persistently high, regardless of insulin levels. The quantifiably different physiologic recovery trajectories reflect altered hormone and metabolic states and imply different responses to therapy.
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PMID:The physiologic recovery trajectory as the organizing principle for the quantification of hormonometabolic adaptation to surgical stress and severe sepsis. 31 78

Sepsis is a major catabolic insult resulting in a peripheral energy deficit which is made up in part by increased breakdown of lean body mass and oxidation of amino acids, principally the branched chain amino acids. The prognosis in any given case of sepsis is difficult to predict, but should theoretically be related to the degree of disturbance in peripheral energy deficit, which may in turn, be related to plasma amino acid pattern. In order to study whether this hypothesis was correct, plasma amino acids and some of their metabolic byproducts, the beta-hydroxyphenylethanolamines, were studied in 25 septic patients, and were used as discriminant variables in a series of computer performed discriminant analyses and multiple regressions. The two functions tested were the degree of metabolic septic encephalopathy as a determinant of the severity of sepsis and the final outcome in the septic patient. Plasma amino acid patterns exhibited elevated levels of the aromatic and sulfur containing amino acids, phenylalanine, tryosine, tryptophan, methionine, cysteine, and taurine, normal concentrations of alanine, and low normal concentrations of the branched chain amino acids, valine, leucine and isoleucine. Arginine levels, as previously noted, were very low. Patients not surviving the septic episode exhibited higher concentrations of aromatic and sulfur containing amino acids, while patients surviving sepsis had higher concentrations of the branched chain amino acids and arginine. When the degree of encephalopathy as a determinant of the severity of sepsis and step wise discriminant analysis with multiple crescent techniques were used, the best discriminant function between patients with and without encephalopathy was found to result from the interaction of cysteine, methionine, phenylalanine, isoleucine, leucine, and valine. These amino acids gave a correct classification in 82% of patients with no encephalopathy, and 80% of patients with septic encephalopathy. When the same amino acids were used for the discriminant analysis for patients dying of sepsis and patients surviving, the best discriminant function was achieved by using plasma concentrations of alanine, cysteine, methionine, isoleucine, arginine, tyrosine and phenylalanine resulting in 91% of the nonsurvivors, and 79% of the survivors correctly classified. The results suggest a close and significant relationship between the deranged energy metabolism and muscle protein breakdown in sepsis, and the outcome. This further suggests a central role for certain amino acids in perhaps predicting the severity of sepsis and its outcome.
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PMID:Plasma amino acids as predictors of the severity and outcome of sepsis. 38 83

The flow of phenylalanine, the essential amino acid precursor of thyroid hormone and catecholamines, was severely elevated in five septic burned patients (6.70 +/- 1.07 mg/kg) and six nonseptic burned patients (5.00 +/- 0.44 mg/kg) when compared with seven normal controls (2.10 +/- 0.33 mg/kg). Fasting serum concentrations of phenylalanine were elevated in the septic burned patients (2.33 +/- 0.37 mg/100 ml of serum) relative to the nonseptic patients (1.28 +/- 0.21 mg/100 ml) and the controls (1.01 +/- 0.15 mg/100 ml). The rate of appearance of the phenylalanine metabolite, tyrosine, after an oral phenylalanine dose was normal in all burn patients. Increased serum concentrations and increased flow of phenylalanine are an index of rapid protein catabolism, further augmented by sepsis in the thermally injured, and not a reflection of decreased hepatic conversion of phenylalanine to tyrosine.
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PMID:Abnormalities of phenylalanine and tyrosine kinetics. Significance in septic and nonseptic burned patients. 62 74

The plasma concentrations of substrates, together with transhepatic and transgut balances, have been studied in six control and eight septic awake fasted dogs. Four severely ill septic dogs (typically fluid in chest and/or abdomen, extensive peritonitis, respiratory difficulties) had high concentrations of threonine, glycine, tyrosine, lysine, histidine, tryptophan, and triglycerides (p less than or equal to 0.05). The other septic dogs (less severely ill) showed fewer and less pronounced alterations in the plasma substrates (aspartate and tryptophan were elevated, p less than or equal to 0.05). The infusion of glucose increased the concentration of glucose, lactate, and pyruvate and depressed the concentrations of most amino acids in both normal and septic dogs. Threonine, asparagine, glutamine, leucine, isoleucine, alpha-aminobutyrate, and tyrosine were significantly depressed in the severely ill septic dogs (p less than or equal to 0.05). In the normal dogs most amino acids were removed by the liver, with alanine accounting for approximately 40% of the total. Glutamine removal was negligible. In the septic dogs hepatic removal of amino acids was variable; livers of two severely ill septic dogs did not remove amino acids. In the control dogs glucose infusion (0.015--0.017 g/kg/min) tended to lower hepatic removal of amino acids. Hepatic dye removal in the septic dogs was always very poor. In the gut glutamine was removed and alanine, glutamate, glycine, and ammonia produced, but the overall sum of amino acid uptake was negligible in both the control and septic dogs. The ratio of tryptophan to the sum of valine, isoleucine, leucine, tyrosine, and phenylalanine concentrations was greatly elevated in all septic dogs in which it was measured. The free concentrations of amino acids in the liver, heart, and muscle tissues were grossly elevated in the low intravenous alimented septic state relative to the fasted normal state, whereas the tissue concentrative ability as measured by nonmetabolizable amino acids, alpha-aminoisobutyrate and cycloleucine, was not similarly increased. Sepsis clearly alters plasma and tissue concentrations, and in some instances hepatic uptake of amino acids.
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PMID:Plasma concentrations and tissue uptake of free amino acids in dogs in sepsis and starvation: effects of glucose infusion--some effects of low alimentation. 65 52

Long-term parenteral feeding in childhood must be adapted to the requirements of the young organism. The caloric requirements are mainly provided by glucose and fat emulsions; additional calories can be supplied by xylite and, with some reservations, by fructose. For neonates and young infants the combination and quantity of amino-acids is of particular importance: histidine, arginine, proline and tyrosine are essential amino-acids; glycine, glutamic acid, aspartic acid and cystine should form part of the unspecific sources of nitrogen. Addition of trace elements and vitamins is obligatory in long-term parenteral feeding. Complications may arise at the site of the catheter (sepsis, clotting). Late damage due to intravenous feeding is known to occurs; but a more detailed knowledge needs long-term investigations.
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PMID:[Problems of long-term parenteral feeding in childhood (author's transl)]. 82 14

Infections or inflammatory states often cause significant increases in serum phenylalanine and the phenylalanine-tyrosine ratio. More than 95% of samples obtained during inflammatory diseases in man showed phenylalanine-tyrosine ratio increases greater than the maximum normal values. An increase in this ratio also occurred in monkeys with induced Rocky Mountain spotted fever, viral encephalitis, yellow fever, or pneumococcal and Salmonella infections, as well as in rats with pneumococcal and Salmonella infections, as well as in rats with pneumococcal, Salmonella or tularemia infections. A similar ratio increase occurred in rats inoculated with unpurified mediator substances (released by activated leukocytes) that appear to initiate many of the secondary metabolic phenomena associated with infection and/or inflammation. To identify responsible mechanisms, rats were given lethal doses of Streptococcus pneumoniae; serum phenylalanine and phenylalanine-tyrosine ratios increased significantly. Hepatic phenylalanine hydroxylase activities were slightly decreased when compared to noninfected controls. Infected and noninfected rats showed comparable oxidation rates for 14C-phenylalanine given with an oral phenylalanine load, as a pulse-oral dose, or as an intraperitoneal injection. After 8 hr, both infected and control rats had similar amounts of radioactivity in total body protein, but tissue distributions were markedly altered during pneumococcal sepsis. Serum proteins of infected rats contained almost twice as much total radioactivity as that found in controls, while the amount of labeled phenylalanine in skeletal muscle protein was significantly reduced in the infected group. Isolated muscles from infected rats released more phenylalanine and less tyrosine than control muscles. Infection-related increases in serum phenlalanine could not be explained by decreased hydroxylation or oxidation. Rather, the data were consistent with an increased flux of phenylalanine into serum, most likely as the result of increased skeletal muscle catabolism. Elevations in the serum phenylalanine-tyrosine ratio have potential value for estimating the presence of an inflammatory fisease and the catabolic state of a patient.
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PMID:The significance and mechanism of an increased serum phenylalanine-tyrosine ratio during infection. 82 5

The sequential changes in plasma free amino acid concentration were analyzed and compared in burned patients with sepsis (n = 12) and without sepsis (n = 19). After burn injury, phenylalanine, methionine, lysine, and the Phe/Tyr ratio were significantly increased in two groups (P < 0.05-0.01). Threonine, serine, histidine, arginine, proline and BCAA/AAA ratio were significantly decreased in two groups (P < 0.05-0.001). The Phel Tyr ratio in patients with sepsis was much higher than that in patients without sepsis on postburn days 14 and 21 (P < 0.05), while the BCAA/AAA ratio in patients with sepsis was much lower than that in patients without sepsis on postburn day 14 (P < 0.01). The level of proline in patients with sepsis was much higher than that in patients without sepsis on postburn days 3 and 7 (P < 0.05). It is suggested that these results, in collaboration with other clinical and laboratory findings, may be helpful in foretelling the probable development of sepsis in patients with major burns.
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PMID:[Changes in plasma free amino acid concentration in burned patients with sepsis]. 130 55

1. The effects of parenteral nutrition with or without xylitol and/or glutamine supplementation were studied in septic rats after 4 days of treatment. 2. Septic rats treated with xylitol- and/or glutamine-supplemented parenteral nutrition survived sepsis significantly better than other parenteral nutrition-treated septic rats: the cumulative percentage of deaths over 4 days in septic rats treated with xylitol-glutamine-supplemented parenteral nutrition was 9.5% compared with 54.5% in septic rats given parenteral nutrition without xylitol and glutamine, and 52.4% in septic rats treated with parenteral nutrition supplemented with glucose. 3. Xylitol- and/or glutamine-supplemented parenteral nutrition resulted in improved nitrogen balance in septic rats: the cumulative nitrogen balance over the 4 days of treatment was positive in the rats given xylitol-supplemented parenteral nutrition and more positive when rats were treated with xylitol-glutamine-supplemented parenteral nutrition, as compared with other groups of septic rats. 4. The rate of loss of intracellular glutamine in skeletal muscle was markedly decreased (P less than 0.001) in response to xylitol- and/or glutamine-supplemented parenteral nutrition in septic rats. 5. Hepatic protein and RNA contents were increased in septic rats treated with xylitol- and/or glutamine-supplemented parenteral nutrition. Similarly, protein and RNA contents were markedly increased in muscles of septic rats treated with xylitol- and/or glutamine-supplemented parenteral nutrition. 6. The rates of incorporation of leucine/tyrosine into liver/muscle proteins in vitro were increased and the rate of muscular tyrosine release was decreased in response to xylitol- and/or glutamine-supplemented parenteral nutrition in septic rats. 7. It is concluded that the administration of xylitol- and/or glutamine-supplemented parenteral nutrition is beneficial to septic rats and possibly to septic patients.
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PMID:Effects of xylitol- and/or glutamine-supplemented parenteral nutrition on septic rats. 137 1

Peroxynitrite (ONOO-), the reaction product of superoxide (O2-) and nitric oxide (NO), may be a major cytotoxic agent produced during inflammation, sepsis, and ischemia/reperfusion. Bovine Cu,Zn superoxide dismutase reacted with peroxynitrite to form a stable yellow protein-bound adduct identified as nitrotyrosine. The uv-visible spectrum of the peroxynitrite-modified superoxide dismutase was highly pH dependent, exhibiting a peak at 438 nm at alkaline pH that shifts to 356 nm at acidic pH. An equivalent uv-visible spectrum was obtained by Cu,Zn superoxide dismutase treated with tetranitromethane. The Raman spectrum of authentic nitrotyrosine was contained in the spectrum of peroxynitrite-modified Cu,Zn superoxide dismutase. The reaction was specific for peroxynitrite because no significant amounts of nitrotyrosine were formed with nitric oxide (NO), nitrogen dioxide (NO2), nitrite (NO2-), or nitrate (NO3-). Removal of the copper from the Cu,Zn superoxide dismutase prevented formation of nitrotyrosine by peroxynitrite. The mechanism appears to involve peroxynitrite initially reacting with the active site copper to form an intermediate with the reactivity of nitronium ion (NO2+), which then nitrates tyrosine on a second molecule of superoxide dismutase. In the absence of exogenous phenolics, the rate of nitration of tyrosine followed second-order kinetics with respect to Cu,Zn superoxide dismutase concentration, proceeding at a rate of 1.0 +/- 0.1 M-1.s-1. Peroxynitrite-mediated nitration of tyrosine was also observed with the Mn and Fe superoxide dismutases as well as other copper-containing proteins.
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PMID:Peroxynitrite-mediated tyrosine nitration catalyzed by superoxide dismutase. 141 74


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