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Query: UMLS:C0243026 (sepsis)
 52,417 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

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

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

Actin has been found to bind to plasmin's kringle regions, thereby inhibiting its enzymatic activity in a noncompetitive manner. We, therefore, examined its effect upon the conversion of plasminogen to plasmin by tissue plasminogen activator. Actin stimulated plasmin generation from both Glu- and Lys-plasminogen, lowering the Km for activation of Glu-plasminogen into the low micromolar range. Accelerated plasmin generation did not occur in the presence of epsilon-amino caproic acid or if actin was exposed to acetic anhydride, an agent known to acetylate lysine residues. Actin binds to tissue plasminogen activator (t-Pa) (Kd = 0.55 microM), at least partially via lysine-binding sites. Actin's stimulation of plasmin generation from Glu-plasminogen was inhibited by the addition of aprotinin and was restored by the substitution of plasmin-treated actin, indicating the operation of a plasmin-dependent positive feedback mechanism. Native actin binds to Lys-plasminogen, and promotes its conversion to plasmin even in the presence of aprotinin, indicating that plasmin's cleavage of either actin or plasminogen leads to further plasmin generation. Plasmin-treated actin binds Glu-plasminogen and t-PA simultaneously, thereby raising the local concentration of t-PA and plasminogen. Together, but not separately, actin and t-PA prolong the thrombin time of plasma through the generation of plasmin and fibrinogen degradation products. Actin-stimulated plasmin generation may be responsible for some of the changes found in peripheral blood following tissue injury and sepsis.
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PMID:Actin accelerates plasmin generation by tissue plasminogen activator. 183 75

Plasma from 7 septic patients with positive blood cultures were studied. None of them presented either clinical or laboratory evidence of Disseminated Intravascular Coagulation. The white cells count varied between 5 and 45 X 10(9)/l. In plasma functional plasminogen levels varied between 25 and 45%, while those of alpha 2-antiplasmin were normal (80-105%). The levels of elastase ranged between 250 and 750 micrograms/ml. Leukocyte elastase digests plasminogen "in vitro" and is able to produce several fragments; one of them called mini-plasminogen lacking lysine binding sites; therefore it does not bind to lysine-Sepharose 4B. Two different behaviors were observed in the plasmatic plasminogen of these patients with respect to their binding capacity to lysine-Sepharose 4 B. 3 patients had plasminogen which did not bind to lysine-Sepharose 4 B; the other 4 had two different components, one of which bound to lysine-Sepharose 4 B and another one which did not bind. Previous studies "in vitro" have shown that leukocyte elastase modifies alpha 2-antiplasmin, initially producing a non-plasminogen binding form. A free alpha 2-antiplasmin (non-plasminogen binding form) was detected in the plasma of these patients with sepsis by crossed immunoelectrophoresis with plasminogen in the first dimension. It seems tenable that high levels of leukocyte elastase could be responsible for these findings although, the possible relationships to leukocyte elastase still remain to be proven but could possibly explain this effect.
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PMID:Mini-plasminogen like molecule in septic patients. 244 46

The protective effect of xanthines against E. coli-induced and cytokine-induced lung injury in guinea-pigs has been demonstrated recently. In the present study, the possible protective effects were examined of an analogue of pentoxifylline, HWA-138, a xanthine derivative, on lung injury in septic guinea-pigs. Three groups of animals were studied over a period of 8 hours: Group I animals--saline control injected intravenously with 3 ml 2% lysine/normal saline followed by a continuous lysine/saline infusion (1 ml/kg/hr); Group II--septic control injected intravenously with 2 x 10(9)/kg Escherichia coli followed by a continuous lysine/saline infusion (1 ml/kg/hr); and Group III--E. coli septicaemia plus HWA-138 continuous infusion (HWA-138 dissolved in lysine/saline) began with a bolus (10 mg/kg) followed by a HWA-138 continuous infusion (3 mg/kg/hr) started 60 minutes before injection of E. coli. Arterial blood pressure and white blood cell counts were monitored serially for 8 hours. Lung water (wet-to-dry ratio) and the concentration ratio of 125I-labelled albumin in bronchoalveolar lavage (BAL) fluid and lung tissue compared to plasma (125I-albumin BAL/plasma, 125I-albumin lung/plasma) were examined. Results demonstrated that an intravenous injection of E. coli caused an increased W/D ratio (p less than 0.01) and an increased 125I-albumin lung/plasma ratio (p less than 0.01). In contrast, the HWA-138-treated group did not demonstrate significantly increased W/D lung ratios (p less than 0.01) and 125I-albumin lung/plasma ratios (p less than 0.05). The data suggest a possible role for HWA-138 in attenuating sepsis-induced lung injury.
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PMID:Attenuation of acute lung injury in septic guinea-pigs by a new xanthine derivative (HWA-138). 268 96

Production of cytotoxin and enterotoxin by Aeromonas strains obtained from stools of 50 children in Mexico and Texas and from blood of 9 children with sepsis was determined. Results were correlated with clinical features of infected children as well as with biochemical traits of Aeromonas strains. Cytotoxin was produced by 40 of 42 Aeromonas strains (95%) isolated from stools of children with diarrhea, by all 8 isolates from stools of well children, and by all 9 isolates from children with sepsis. There was no difference in the quantities (amount of cytotoxin per milligram of protein required to kill 50% of the cells) of cytotoxin produced and in clinical manifestations among the groups. None of the isolates produced a toxin that could be neutralized by antiserum raised against Shiga toxin produced by Shigella dysenteriae 1 60R. Heat-labile-like enterotoxin (LT) was produced by 26 of 42 stool isolates (62%), while only 1 of the 42 isolates (2%) produced enterotoxinlike activity in suckling mice; 65% of the cytotoxin-producing strains also produced an LT-like material. All strains from blood produced LT-like material, and 2 of 6 (33%) produced activity in suckling mice. All strains produced hemolysin; 37 of 57 (65%) were Voges-Proskauer positive; 27 of 57 (47%) were lysine decarboxylase positive by API 20E strips, none were positive for lysine decarboxylose production by lysin-iron agar slants at 24 h, but 17 of 54 (31%) were positive at 48 h. There was no correlation between biochemical reactions and enterotoxin or cytotoxin production. There appears to be no correlation between toxin production by Aeromonas spp. and gastroenteritis.
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PMID:Clinical and biochemical significance of toxin production by Aeromonas hydrophila. 358 26

The metabolic derangement of sepsis leads to changes of the plasma and muscle amino acid (AA) pattern. In this study the influence of a septic process on liver AA pattern was investigated. In seven patients with abdominal sepsis, liver AA concentrations were determined during surgery and compared with those of four patients who had undergone cholecystectomy. In sepsis lowered AA levels were found for most of the AAs. Outstanding decreases exhibited the levels of the gluconeogenetic AAs (especially threonine and alanine), the branched chain AAs, lysine, and taurine. In the patients who did not survive the septic process, the depletion of these AAs was even amplified. Slightly increased AA levels were analyzed for P-ethanolamine, cystathionine, citrulline, beta-alanine, tyrosine, and phenylalanine. The results indicate a disturbed free AA pattern of the septic liver. Despite the increased flux of gluconeogenetic AA from muscle to liver in sepsis, as reported by several authors, no accumulation of these AAs occurs in the liver.
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PMID:Liver amino acids in sepsis. 398 19

Measurement of protein synthesis in individual organs is important in understanding metabolic changes in injury, sepsis, or starvation. Methods, mostly isotopic, for measuring synthesis are plagued by problems of experimental design and interpretation. Thus it is desirable to use a variety of methods based on different assumptions. The present study is the first to isolate radioactive aminoacyl-tRNA in the study of protein synthesis in muscle and skin. Male rats, 200-300 g, trained to eat chow for 4 hr/day were studied at 2 hr (absorptive) or 16 hr (postabsorptive) after a meal. Under ether anesthesia, a tracer dose of L-[4-5-3H(N)]-lysine was infused at a constant rate. At 20, 30, or 40 min 1 ml of arterial blood was withdrawn and 2-g samples of skin and thigh muscle were quickly excised and frozen. Samples were pooled from 4 to 7 rats for each infusion period. Concentrations and specific activities were determined for plasma lysine, and for free, tRNA, and protein-bound lysine in muscle and skin. Protein renewal rates in absorptive and postabsorptive periods averaged 6 and 9% per day in muscle, and 20 and 35% in skin. The data for muscle confirms results of other methods and suggests little contribution of rapidly turning over protein. The contribution of skin to whole body protein synthesis, about 500 mg . 100 g-1 . day-1, is similar in magnitude to the contributions of muscle, liver, or intestine.
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PMID:Protein synthesis rates in rat muscle and skin based on Lysyl-tRNA radioactivity. 640 30

Gluconeogenic and oxidative capabilities with lactate as a substrate were studied in perfused livers isolated from rats in late sepsis. Glucose release in the presence of 5 mM lactate was significantly depressed in livers from septic rats. When gluconeogenesis was stimulated by phenylephrine, livers from septic rats exhibited both a decreased sensitivity and lower maximal rate of glucose release when compared with livers from sham-operated rats. Oxygen consumption (VO2) by perfused livers from septic rats was also depressed under the above conditions. The addition of lysine in concentrations greater than 0.5 mM restored glucose production in livers from septic rats to a rate not different from sham-operated controls but did not restore VO2. However, inclusion of lysine (5 mM) in the perfusate was not able to restore sensitivity to stimulation by phenylephrine in livers from septic rats. Although hepatic ATP levels were depressed in sepsis, the decrease was not sufficient to explain the decreased rates of glucose production. We conclude from these results that primary cellular defects in gluconeogenic and oxidative capabilities occur during sepsis that are independent of inadequate perfusion.
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PMID:Regulation of glucose production from lactate in experimental sepsis. 640 37


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