Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0243026 (sepsis)
 52,417 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The branched-chain amino acids (BCAAs; valine, isoleucine, and leucine) are the major nitrogen source for glutamine and alanine synthesis in muscle. Synthesis of glutamine, alanine, and BCAA use is activated in critical illnesses such as in sepsis, cancer, and trauma. The use of glutamine often exceeds its synthesis, resulting in the lack of glutamine in plasma and tissues. In critical illness, resynthesis of BCAA from branched-chain keto acids is activated, particularly in hepatic tissue. The BCAA released to circulation may be used for protein synthesis or synthesis of alanine and glutamine. Glutamine and/or alanine infusion has an inhibitory effect on the breakdown of body proteins and decreases BCAA catabolism in postabsorptive control, endotoxemic, and irradiated rats. Decreased protein breakdown also was observed when glutamine synthesis was activated by ammonia infusion. In conclusion some favorable effects of BCAA supply can be explained by its role in the synthesis of glutamine and some positive effects of glutamine exogenous supply can be explained by its effect on metabolism of BCAA.
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PMID:Relation between glutamine, branched-chain amino acids, and protein metabolism. 1184 43

The reduced pressure response to vasopressin during acute sepsis has directed our interest to the regulation of vasopressin V(1A) receptors. Rats were injected with lipopolysaccharide for induction of experimental gram-negative sepsis. V(1A) receptor gene expression was downregulated in the liver, lung, kidney, and heart during endotoxemia. Inasmuch as the concentrations of proinflammatory cytokines such as interleukin-1beta, tumor necrosis factor-alpha, and interferon-gamma were highly increased during sepsis, the influence of these cytokines on V(1A) receptor expression was investigated in primary cultures of hepatocytes and in the aortic vascular smooth muscle cell line A7r5. V(1A) receptor expression was downregulated by the cytokines in a nitric oxide-independent manner. Blood pressure dose-response studies after injection of endotoxin showed a diminished responsiveness to the selective V(1) receptor agonist Phe(2),Ile(3),Orn(8)-vasopressin. Our data show that sepsis causes a downregulation of V(1A) receptors and suggest that this effect is likely mediated by proinflammatory cytokines. We propose that this downregulation of V(1A) receptors contributes to the attenuated responsiveness of blood pressure in response to vasopressin and, therefore, contributes to the circulatory failure in septic shock.
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PMID:Cytokine-mediated downregulation of vasopressin V(1A) receptors during acute endotoxemia in rats. 1189

The mechanism by which glutamine produces a favorable effect in the treatment of sepsis, injury, burns and abdominal irradiation is not completely understood. The main aim of this study was to evaluate the effect of alanyl-glutamine (AlaGln) administration on the metabolism of proteins in irradiated rats. The rats were exposed to whole-body irradiation (8Gy) and then fed intragastrically with a mixture of glucose and amino acids either with AlaGln or without AlaGln. At 48 hours after irradiation, parameters of whole-body protein metabolism and DNA synthesis in intestinal mucosa were investigated using a primed, continuous infusion of [1-14C]leucine and [3H]thymidine. In addition, we evaluated the effect of irradiation and AlaGln on gut morphology, blood count and amino acid concentrations in blood plasma and skeletal muscle. Control rats were not irradiated but were given identical treatment. An increase in whole-body leucine oxidation, and insignificant changes in whole-body proteolysis and in protein synthesis were observed after irradiation. In irradiated rats we observed a decrease in muscle glutamine concentration, a decrease in protein synthesis in jejunum, colon and heart, and an increase in synthesis of proteins of blood plasma and spleen. Morphological examination and measurement of DNA synthesis failed to demonstrate any favorable effect of AlaGln supplementation on irradiated gut. However, administration of AlaGln resulted in a decrease in whole-body proteolysis and leucine oxidation which caused an increase in the fraction of leucine incorporated into the pool of body proteins. We conclude that the data obtained demonstrate that irradiation induces metabolic derangement associated with increased oxidation of essential branched-chain amino acids (valine, leucine and isoleucine) and that these disturbances can be ameliorated by administration of AlaGln.
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PMID:Effect of alanyl-glutamine on leucine and protein metabolism in irradiated rats. 1202 76

Branched chain organic acidurias are a group of disorders that result from an abnormality of specific enzymes involving the catabolism of branched chain amino acids (leucine, isoleucine, valine). Maple syrup urine disease (MSUD), isovaleric acidaemia (IVA), propionic aciduria (PA) and methylmalonic aciduria (MMA) represent the most commonly encountered abnormal organic acidurias. All these four disorders present in neonates as a neurologic distress of the intoxication type with either ketosis or ketoacidosis and hyperammonaemia. There is a free interval between birth and clinical symptoms. MMA, PA and IVA present with a severe dehydration, leuconeutropenia and thrombopenia which can mimic sepsis. All these disorders can be diagnosed by identifying acylcarnitine and other organic acid compounds in plasma and urine by gas chromatography mass spectrometry or tandem MS-MS. These disorders are amenable to treatment by removing toxic compounds and by using special diets and carnitine.
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PMID:Branched-chain organic acidurias. 1206 39

This is a retrospective study of limb amputations in Ile-Ife, Nigeria during a thirteen-year period (1987-1999). 82 patients were studied with a mean age of 35 +/- 22 years. 63 of the patients were adults, while 19 patients were children aged 15 years and below. Trauma was indicated as a reason for amputation in 60 patients (73.4%). Road traffic accident with peripheral vascular compromise was the single most common reason for amputation (41.7%). Forty-seven of the 82 patients had lower limb amputations, while the others were in the upper limbs. There was delay in performing amputation in some patients due to refusal to accept the procedure in 10(12.1%), logistics in 5(6.1%) and lack of finance in 3 (3.7%). The average healing time of the amputation stump wounds was 47 +/- 36 days. In 68.3% of cases, there was wound infection and the wound healing time was 63 +/- 45 days, much longer than than the general average. Other complications were flap necrosis, gas gangrene, osteomyelitis of the bony stump, and tetanus. Six patients died from sepsis and one from chronic renal failure, a hospital mortality rate of 8.5%. Prosthesis could not be fitted in any of the patients during the hospital admission and only three of the diabetic patients attended follow up clinic for up to two years; others absconded within 3 months of discharge from hospital. It will be possible to reduce the rate of amputation and improve the quality of life of patients with amputation if more attention is placed on accident prevention and injury control.
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PMID:Indications for amputations in Ile-Ife, Nigeria. 1222 53

Many bacterial pathogens secrete proteins that activate host trypsinogen-like enzyme precursors, most notably the proenzymes of the blood coagulation and fibrinolysis systems. Staphylococcus aureus, an important human pathogen implicated in sepsis and endocarditis, secretes the cofactor staphylocoagulase, which activates prothrombin, without the usual proteolytic cleavages, to directly initiate blood clotting. Here we present the 2.2 A crystal structures of human alpha-thrombin and prethrombin-2 bound to a fully active staphylocoagulase variant. The cofactor consists of two domains, each with three-helix bundles; this is a novel fold that is distinct from known serine proteinase activators, particularly the streptococcal plasminogen activator streptokinase. The staphylocoagulase fold is conserved in other bacterial plasma-protein-binding factors and extracellular-matrix-binding factors. Kinetic studies confirm the importance of isoleucine 1 and valine 2 at the amino terminus of staphylocoagulase for zymogen activation. In addition to making contacts with the 148 loop and (pro)exosite I of prethrombin-2, staphylocoagulase inserts its N-terminal peptide into the activation pocket of bound prethrombin-2, allosterically inducing functional catalytic machinery. These investigations demonstrate unambiguously the validity of the zymogen-activation mechanism known as 'molecular sexuality'.
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PMID:Staphylocoagulase is a prototype for the mechanism of cofactor-induced zymogen activation. 1452 51

In meningococcal sepsis, disseminated intravascular coagulation with deposition of fibrin and formation of microthrombi occurs in various organs and enhanced inhibition of fibrinolysis is associated with adverse outcome. Recently, TAFI (thrombin-activatable fibrinolysis inhibitor) was identified as a link between coagulation and fibrinolysis, as TAFI can be activated by thrombin and once activated potently attenuates fibrinolysis. On the basis of this one would predict that DNA polymorphisms that increase TAFI activity would deteriorate the outcome in meningococcal sepsis. Therefore, we studied the prevalence of the Thr325Ile dimorphism in the TAFI gene, which is associated with increased TAFIa stability and activity in 50 patients who survived meningococcal disease, in 176 first-degree relatives of a consecutive patient series with meningococcal disease and 212 controls from the same geographic region. The TAFI 325 Ile/Ile genotype was slightly more common among parents of patients with meningococcal disease than in controls (11% vs. 7.1%, P= 0.24). This difference was pronounced among the subgroup of parents of non-surviving patients (19.2%, P= 0.03). Patients whose parents were carriers of the TAFI 325 Ile/Ile genotype had a 1.6-fold (95% CI 0.7-3.7) higher risk to contract meningococcal disease and a 3.1-fold (95% CI 1.0-9.5) increased risk to die from the infection compared with all other genotypes. Survivors had a genotype frequency (4.0%) that was lower than in the general population. TAFI 325 variants affect the outcome of meningococcal disease.
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PMID:A functional single nucleotide polymorphism in the thrombin-activatable fibrinolysis inhibitor (TAFI) gene associates with outcome of meningococcal disease. 1471 66

Vascular permeability plays a key role in a wide array of life-threatening and sight-threatening diseases. Vascular endothelial growth factor can increase vascular permeability. Using a model system for nonproliferative diabetic retinopathy, we found that pigment epithelium-derived factor (PEDF) effectively abated vascular endothelial growth factor-induced vascular permeability. A 44-amino acid region of PEDF was sufficient to confer the antivasopermeability activity. Additionally, we identified four amino acids (glutamate-101, isoleucine-103, leucine-112, and serine-115) critical for this activity. PEDF, or a derivative, could potentially abate or restore vision loss from diabetic macular edema. Furthermore, PEDF may represent a superior therapeutic approach to sepsis-associated hypotension, nephrotic syndrome, and other sight-threatening and life-threatening diseases resulting from excessive vascular permeability.
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PMID:Identification of the antivasopermeability effect of pigment epithelium-derived factor and its active site. 1509 82

TNF-alpha is a mediator of insulin resistance in sepsis, obesity, and type 2 diabetes and is known to impair insulin signaling in adipocytes. Akt (protein kinase B) is a crucial signaling mediator for insulin. In the present study we examined the posttranslational mechanisms by which short-term (<6-h) exposure of 3T3-L1 adipocytes to TNF-alpha decreases Akt levels. TNF-alpha treatment both increased the ubiquitination of Akt and decreased its protein level. The decrease in protein was associated with the presence of an (immunoreactive) Akt fragment after TNF-alpha treatment, indicative of Akt cleavage. The broad-spectrum caspase inhibitor t-butoxycarbonyl-Asp(O-Me)-fluoromethyl ketone markedly suppressed these effects of TNF-alpha. The caspase-6 inhibitor Z-Val-Glu(OMe)-Ile-Asp(OMe)-CH(2)F potently suppressed Akt ubiquitination, degradation, and fragment formation, whereas the proteasome inhibitor Z-Leu-Leu-Leu-CHO modestly attenuated the decline in Akt levels. Exposure to TNF-alpha also enhanced the association of Akt with an E3 ligase activity. Adipocytes preexposed to TNF-alpha for 5 h and then stimulated with insulin for 30 min exhibited decreased levels of Akt, phosphorylated Akt, as well as phosphorylated Mdm2, which is a known direct substrate of Akt, and glucose uptake. Caspase inhibition attenuated these inhibitory effects of TNF-alpha. Collectively, our results suggest that TNF-alpha induces the caspase-dependent degradation of Akt via the cleavage and ubiquitination of Akt, which results in its degradation through the 26S proteasome. Furthermore, the caspase- and proteasome-mediated degradation of Akt due to TNF-alpha exposure leads to impaired Akt-dependent insulin signaling in adipocytes. These findings expand the mechanism by which TNF-alpha impairs insulin signaling.
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PMID:Tumor necrosis factor-{alpha} decreases Akt protein levels in 3T3-L1 adipocytes via the caspase-dependent ubiquitination of Akt. 1574 49

Acute and chronic ischaemic diseases are among the main death reasons and civilized world menace. Branched chain amino acids (BCAAs): valine (Val), leucine (Leu), and isoleucine (Ile) are the main source of nitrogen to glutamine (Gln) and alanine (Ala) synthesis in muscles. In numerous cachexy-producing illnesses such as cancer, sepsis, diverse injuries and heart diseases increased consumption of BCAAs occurs. In myocardial ischemia BCAAs derived from the mobilization of muscle protein may be an important alternative energy substrate for the heart. BCAAs are oxidative energy substrates for the heart and may exert anabolic effects on myocardial protein (8). The aim of our study was to determine branched chain amino acids (BCAAs) concentrations in blood plasma of patients with chronic and acute ischeamic heart disease and to find out changes that those amino acids undergo during the first five days of patients' hospitalization.
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PMID:Branched chain amino acids (BCAAs) in heart diseases (ischaemic heart disease and myocardial infarction). 1614 56


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