Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In recent years, the concept has emerged that the host's inflammatory response contributes substantially to the development of septic shock and organ failure. Experimental observations prompted large scale randomised clinical trials with a variety of agents such as glucocorticoids, ibuprofen, antiendotoxin monoclonal antibodies, antagonists of platelet-activating factor, of bradykinin or of interleukin-1 receptor, and monoclonal anti-tumour necrosis factor (TNF) antibodies or soluble dimeric TNF receptor fusion proteins. All these major studies of immunomodulators in sepsis have yielded disappointing results despite showing promise during preliminary clinical studies. However, these recent failures do not mean that septic shock will forever remain an insurmountable medical challenge. Many lessons have been learned from these studies. and certain mistakes in their study design will be avoided in the future. Our understanding of the pathophysiology of sepsis and septic shock is increasing markedly; potential new treatment strategies are available and could be explored to improve the outcome of patients with sepsis.
 ...
PMID:Treatment of sepsis: past and future avenues. 1018 56

C1-esterase inhibitor (C1-Inh) therapy was introduced in clinical medicine about 25 years ago as a replacement therapy for patients with hereditary angioedema caused by a deficiency of C1-Inh. There is now accumulating evidence, obtained from studies in animals and observations in patients, that administration of C1-Inh may have a beneficial effect as well in other clinical conditions such as sepsis, cytokine-induced vascular leak syndrome, acute myocardial infarction, or other diseases. Activation of the complement system, the contact activation system, and the coagulation system has been observed in these diseases. A typical feature of the contact and complement system is that on activation they give rise to vasoactive peptides such as bradykinin or the anaphylatoxins, which in part explains the proinflammatory effects of either system. C1-Inh, belonging to the superfamily of serine proteinase inhibitors (serpins), is a major inhibitor of the classical complement pathway, the contact activation system, and the intrinsic pathway of coagulation, respectively. It is, therefore, endowed with anti-inflammatory properties. However, inactivation of C1-Inh occurs locally in inflamed tissues by proteolytic enzymes (e.g., elastase) released from activated neutrophils or bacteria thereby leading to increased local activation of the various host defense systems. Here we will give an overview on the biochemistry and biology of C1-Inh. We will discuss studies addressing therapeutic administration of C1-Inh in experimental and clinical conditions. Finally, we will provide an explanation for the therapeutic benefit of C1-Inh in so many different diseases.
 ...
PMID:C1-Esterase inhibitor: an anti-inflammatory agent and its potential use in the treatment of diseases other than hereditary angioedema. 1069 56

In pregnancy and puerperium disseminated intravascular coagulopathy may accompany abruptio placenta, intrauterine fetal demise with retained dead fetus, amniotic fluid embolism, endotoxin sepsis, preecalampsia with HELLP and massive transfusion. Clinical signs and symptoms of DIC can include oozing from venipuncture sites and/or mucous membranes, red cell lysis from activation of the complement system, hemorrhage from coagulopathy and possible uterine atony, hypotension from hemorrhage and/or bradykinin release, and oliguria from end-organ insult and hypovolemia/hypotension. Treatment of DIC consists of replacement of volume, blood products, and coagulation components and cardiovascular and respiratory support with elimination of underlying triggering mechanism.
 ...
PMID:Disseminated intravascular coagulopathy in pregnancy: thorough comprehension of etiology and management reduces obstetricians' stress. 1076 41

Studies investigating the role of bradykinin in disease states such as hypertension, sepsis, and asthma have been confounded by difficulties in measuring the concentration of this short-lived peptide. The purpose of this study was to determine a stable metabolite of bradykinin in the systemic circulation of humans. Bradykinin (containing trace concentrations of [(3)H]bradykinin) was administered i.v. into three human volunteers in increasing amounts up to a maintenance rate of 200 ng/kg/min until a total dose of 1 mg was given. Metabolic products were purified and identified by HPLC and by electrospray ionization mass spectrometry. Infused bradykinin was rapidly degraded, such that no exogenous bradykinin was detected in venous plasma sampled during infusion. BK1-5 (Arg-Pro-Pro-Gly-Phe), the 1-to-5 amino acid fragment of bradykinin, was identified as a major stable plasma metabolite of bradykinin. Plasma concentrations of BK1-5 correlated with dose of bradykinin infused and concentrations at the end of bradykinin infusion were 1510 to 4600 fmol/ml of blood. BK1-5 was cleared from blood with a terminal half-life of 86 to 101 min. Thus, in humans, bradykinin is rapidly degraded in vivo to BK1-5, a stable metabolite. Measurement of this metabolite could provide a tool to assess pathophysiologic and pharmacologic alterations in systemic bradykinin generation associated with human disease.
 ...
PMID:Metabolism of bradykinin In vivo in humans: identification of BK1-5 as a stable plasma peptide metabolite. 1087 21

Extensive research has provided few therapeutic agents for the treatment of septicemia. Bradykinin, an endogenous vasodepressor hormone, is a key mediator in the hypotension seen with septicemia. The present investigation shows that a stable metabolic fragment of bradykinin, arginine-proline-proline-glycine-phenylalanine (RPPGF), prevents the deleterious effects of endotoxin [lipopolysaccharide (LPS); a component of the membrane of Gram negative bacteria], the signaling agent responsible for the effects of septicemia, in both anesthetized rats and in isolated rat aortic segments. Survival time of rats treated with LPS (12 mg/kg) was significantly (p < 0.05) prolonged by pretreatment with RPPGF [140.3 +/- 16 min (n = 10)] compared with rats receiving saline and LPS [93.2 +/- 8 min (n = 39)]. Prolongation of survival was not seen when rats were pretreated with either bradykinin or with PRGFP (proline-arginine-glycine-phenylalanine-proline). Isolated aortic segments treated with LPS (30 microg/ml) showed a significantly reduced ability to contract in response to phenylephrine compared with control segments not receiving LPS. Pretreatment of the segments with RPPGF significantly reversed the LPS-induced reduction in contractile response of the segments. Removal of the endothelial layer did not alter the protection provided by RPPGF. These results demonstrate the ability of a stable metabolic fragment of bradykinin, RPPGF, to protect against the deleterious effects produced by LPS. The findings presented here may provide the basis for a new developmental area for novel therapeutic agents in the treatment of septicemia.
 ...
PMID:A metabolic fragment of bradykinin, Arg-Pro-Pro-Gly-Phe, protects against the deleterious effects of lipopolysaccharide in rats. 1112 64

Staphylococcus aureus is a prominent human pathogen. Here we report that intact S. aureus bacteria activate the contact system in human plasma in vitro, resulting in a massive release of the potent proinflammatory and vasoactive peptide bradykinin. In contrast, no such effect was recorded with Streptococcus pneumoniae. In the activation of the contact system, blood coagulation factor XII and plasma kallikrein play central roles, and a specific inhibitor of these serine proteinases inhibited the release of bradykinin by S. aureus in human plasma. Furthermore, fragments of the cofactor H-kininogen of the contact system efficiently blocked bradykinin release. The results suggest that activation of the contact system at the surface of S. aureus and the subsequent release of bradykinin could contribute to the hypovolemic hypotension seen in patients with severe S. aureus sepsis. The data also suggest that the contact system could be used as a target in the treatment of S. aureus infections.
 ...
PMID:Staphylococcus aureus induces release of bradykinin in human plasma. 1134 54

The kallikrein-kinin system plays an important role in many physiological and pathophysiological conditions such as homeostasis of circulation, inflammation/allergy, pain, shock, etc. Two types of kinin receptor are known, bradykinin (BK) B1 receptor and BK B2 receptor. B2 receptors are constitutively expressed and mediate most physiological actions of kinins, whereas B1 receptors are highly inducible upon inflammatory stimulation or tissue injury, suggesting that they are involved in inflammation and/or nociception. Only three peptide type B2 antagonists, NPC 567, CP-0127 and HOE-140, have been evaluated in clinical studies so far, and some beneficial effects of B2 antagonists have been shown for rhinitis, asthma, systemic inflammatory response syndrome/sepsis and brain injury. However, the results were less convincing than expected. Now several potent and orally active nonpeptide B2-receptor antagonists have been found, which are expected to overcome the weak point of the peptide type antagonists and clarify the therapeutic potential of the B2-receptor antagonist for novel indications as well as those mentioned above. As for B1 receptors, no antagonist has been tested in a clinical trial. The important role of B1 receptors is just being elucidated by use of peptide type antagonists or B1 receptor gene knockout mice. The further development of newer B1 antagonists and clinical evaluation is desired.
 ...
PMID:[Bradykinin antagonist: current status and perspective]. 1186 56

C1 inhibitor (C1-Inh) is a protease inhibitor of the serpin family. It interacts and forms complexes with several serine proteases although not all these interactions were proved to be relevant in vivo. Based on studies in deficient patients, C1-Inh appears pivotal in regulating the activation of complement classical pathway and of contact system. The best recognized consequence of defective C1-Inh function is predisposition to episodes of self-limited, increased vascular permeability (angioedema) that is restricted to three specific sites, which include the subcutaneous space, the gut and the upper airway. Candidate mediator of angioedema is bradykinin, a potent vasoactive peptide, released upon contact system activation. Mutations in C1-Inh structural gene are the most common cause of C1-Inh deficiency and lead to hereditary angioedema. Recurrent angioedema are also seen in the acquired defect of C1-Inh that is due to autoantibodies against this protein or to an associated disease causing accelerated catabolism of C1-Inh. Apart from the profound deficiency of C1-Inh characteristic of angioedema, it has been suggested that, in specific pathologic settings, C1-Inh levels in the low normal range could still represent a significant functional deficiency. Such conditions, as extensively investigated in sepsis, are of great relevance because they open the possibility of using C1-Inh as therapeutic agent in several different diseases.
 ...
PMID:Mechanisms of C1-inhibitor deficiency. 1239 14

Kinins are peptide hormones that exert pathophysiological as well as pronounced beneficial physiological effects, mainly by stimulation of bradykinin (BK) B(2) receptors. Owing to the strong proinflammatory properties of kinins resulting from vasodilation, plasma extravasation, activation of mast cells, fibroblasts and macrophages, stimulation of sensory neurons, and the release of nitric oxide, prostaglandins, leukotrienes and cytokines, kinins are believed to play an important role in a variety of inflammatory diseases and pain. Beneficial effects of BK B(2) receptor antagonists in perennial rhinitis, asthma and brain edema have already been shown in clinical trials. Recently, the potential therapeutic utility of BK B(2) receptor antagonists has been extended by the discovery of orally active, nonpeptide BK B(2) receptor antagonists and the identification of novel indications for their use. On the other hand, kinins also have been identified as potent antihypertensive and organ-protective peptides. They have been shown to have vasodilatory, antihypertrophic, antiaggregatory and fibrinolytic effects due to the BK B(2) receptor-mediated release of the autacoids nitric oxide, prostacyclin and tissue plasminogen activator. A recent finding is that kinins are also involved in ischemic preconditioning. Orally active, nonpeptide BK B(2) receptor agonists as potential novel therapeutic agents in cardiovascular medicine have also been identified. In conclusion, interaction with the BK B(2) receptor by either its blockade or its stimulation offers promising therapeutic approaches. BK B(2) receptor antagonists may prove to be useful in the treatment of asthma, rhinitis, arthritis, colitis, pancreatitis, sepsis, edema, tissue injury, pain and possibly infections, hepatorenal syndrome, Alzheimer's disease and lung cancer. BK B(2) receptor agonists have potential in the treatment of cardiovascular diseases like hypertension, cardiac hypertrophy, restenosis and myocardial infarction and diabetic disorders.
 ...
PMID:Bradykinin B2 receptor as a potential therapeutic target. 1293 26

Activation of the so-called contact system has 2 major consequences; initiation of the intrinsic pathway of coagulation and the release of bradykinin, a highly potent proinflammatory peptide inducing vascular permeability and capillary leakage. Several significant human pathogens have the ability to activate the contact system, and the potential significance of this mechanism in bacterial virulence, including its role in sepsis, is discussed in this review.
 ...
PMID:Contact activation by pathogenic bacteria: a virulence mechanism contributing to the pathophysiology of sepsis. 1462 Jan 42


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>