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

DIC is a hemorrhagic syndrome frequently encountered as a complication in severe gram-negative bacterial sepsis. An animal model for sepsis-associated DIC was developed in order to permit study of the appearance and development of this syndrome in relation to the entire disease process. Rhesus monkeys (4 to 6 kg) were infected by intravenous injection of 10(9) Salmonella typhimurium organisms and studied for a period of 7 to 10 days following infection. Ten of 23 infected monkeys developed petechial rash characteristic of DIC, which appeared on days 1 to 2 infection and lasted 4 to 5 days. In the group of monkeys developing rash, activation of coagulation was suggested by an 80% decrease in platelet count and 20% to 30% increases in PT and APTT. Fibrinolytic system activation was indicated by the appearance of FDP. Kinin system activation was evidenced by decreases in both prekallikrein nad kininogen. Changes in laboratory tests suggestive of subclinical DIC were also noted in infected monkeys which did not develop a rash. Pathologic evidence of DIC was obtained through observation of numerous fibrin thrombi in the kidneys of the only monkey which died in the course of infection. Occurrence of DIC in association with this experimental infection in rhesus monkeys was established on the basis of clinical, laboratory, and pathologic criteria. Expression of the syndrome on days 1 to 2 following infection correlated with the period of increasing bacteremia.
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PMID:Model for disseminated intravascular coagulation: bacterial sepsis in rhesus monkeys. 9 3

Plasma kallikrein releases bradykinin when activated by gram-negative septicemia or irreversible hemorrhagic shock. Pancreatitis releases glandular kallikrein causing hypotension and increased vascular permeability. Bradykinin in the brain produces hypertension. Renal kallikrein is released by high arterial pressure, vasodilators, low doses of noradrenaline, angiotensin II, mineralocorticoids and rapid volume expansion. It has a biphasic relation to sodium excretion. In essential hypertension, kallikrein release into the blood and urine is low and facilitates hypertension. High renin in Bartter's syndrome is balanced by high PGE and kallikrein without hypertension.
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PMID:Kallikrein, kininogen and kinins in control of blood pressure. 37 13

To determine whether or not kinin activation in the blood during severe infection with gram-negative bacteria may be related to hemodynamic abnormalities encountered, blood prekallikrein, kallikrein inhibitor and kinin values in 2l surgical patients with sepsis were compared with those in normotensive and hypotensive states. Because of reduced prekallikrein synthesis in patients with hepatic insufficiency, the normotensive and hypotensive groups were each subdivided according to the presence or absence of liver dysfunction, as indicated by elevated blood bilirubin, serum glutamic-oxalacetic transaminase or alkaline phosphatase levels. The mortality was zero in group 1, normotensive normal liver function; 80 per cent in group 2, hypotensive-normal liver function; 20 per cent in group 3, normotensive liver dysfunction, and 67 per cent in group 4, hypotensive liver dysfunction. Ultimately, the majority of deaths were due to respiratory failure. Although the blood prekallikrein level, was below normal in all groups and was significantly less in all patients with liver dysfunction, it was reduced proportionately in hypotensive patients to less than 30 per cent of the values noted in the two normotensive groups. This finding suggests prekallikrein consumption in the hypotensive groups to be the result of the process of activating kallikrein and bradykinin. This concept is supported by finding elevated kinin values, above 3 nanograms per milliliter of plasma, in only 28 per cent of those in group 1 and 12 per cent of those in group 3, while in the hypotensive patients, groups 2 and 4, the kinin level was elevated in 60 and 66 per cent, respectively.
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PMID:Kinin activation in the blood of patients with sepsis. 95 70

Angiotensin converting enzyme (ACE) is present on endothelial cells and plays a role in regulating blood pressure in vivo by converting angiotensin I to angiotensin II and metabolizing bradykinin. Since ACE activity is decreased in vivo in sepsis, the ability of lipopolysaccharide (LPS) to suppress endothelial cell ACE activity was tested by culturing human umbilical vein endothelial cells (HUVEC) for 0-72 hr with or without LPS and then measuring ACE activity. ACE activity in intact HUVEC monolayers incubated with LPS (10 micrograms/ml) decreased markedly with time and was inhibited by 33%, 71%, and 76% after 24 hr, 48 hr, and 72 hr, respectively, when compared with control, untreated cells. The inhibitory effect of LPS was partially reversible upon removal of the LPS and further incubation in the absence of LPS. The LPS-induced decrease in ACE activity was dependent on the concentrations of LPS (IC50 = 15 ng/ml at 24 hr) and was detectable at LPS concentrations as low as 1 ng/ml. That LPS decreased the Vmax of ACE in the absence of cytotoxicity and without a change in Km suggests that LPS decreased the amount of ACE present on the HUVEC cell membrane. While some LPS serotypes (Escherichia coli 0111:B4 and 055:B5, S. minnesota) were more potent inhibitors of ACE activity than others (E. coli 026:B6 and S. marcescens), all LPS serotypes tested were inhibitory. These finding suggest that LPS decreases endothelial ACE activity in septic patients; in turn, this decrease in ACE activity may decrease angiotensin II production and bradykinin catabolism and thus play a role in the pathogenesis of septic shock.
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PMID:Lipopolysaccharides decrease angiotensin converting enzyme activity expressed by cultured human endothelial cells. 131 Mar 27

The hypotension in septicemia is believed to be mediated by the combined action of many mediators including cytokines, prostaglandins, and complement components. To evaluate the contribution of the contact/kinin-forming system to hypotension, the authors used an established experimental baboon model of bacteremia in which two concentrations of Escherichia Coli (E. coli) were used to produce lethal and nonlethal hypotension. The lethal group (n = 5) developed irreversible hypotension that significantly correlated with the decline in levels of high molecular weight kininogen (HK) and an increase in alpha 2 macroglobulin-kallikrein complexes (alpha 2M-kal). The nonlethal group (n = 9) experienced reversible hypotension, a less striking decline in HK, and only slight elevation in alpha 2M-kal. No significant changes were found in levels of factor XII, prekallikrein, and factor XI in either group. A significant change in the contact system, which reflects the fatal outcome, is the rise in alpha 2M-kal. This study suggests that irreversible hypotension correlates with prolonged activation of the contact system.
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PMID:Activation of the contact system in lethal hypotensive bacteremia in a baboon model. 137 71

Coagulation and fibrinolysis are not activated in an isolated system but it involves numerous interrelations with the kininogen-kinin pathway and the complement. In severe sepsis, substances released by microorganisms, notably lipopolysaccharides, can activate the contact system, and particularly in such circumstances, contact activation probably plays a role in the occurrence of haemodynamic changes and consumption coagulopathy. Evidence of kininogen-kinin pathway activation as assessed by biological investigations in patients with severe sepsis, could lead to the therapeutical use of natural or synthetic protease inhibitors.
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PMID:[Contact factors in severe sepsis]. 153 87

Widespread intravascular coagulation is common in patients with sepsis. Coagulation abnormalities may result from exposure to endotoxin, from tumor necrosis factor alpha or interleukin 1 release, or from the actions of a more specific mediator, such as vascular permeability factor. The result is marked activation of the contact and coagulation systems; simultaneously, there is decreased fibrinolysis and depressed levels of the inhibitors of the contact and coagulation systems. Multiple agents are being studied to correct these abnormalities. Antithrombin III holds promise because it inhibits a number of factors important in contact and coagulation activation, not just thrombin. Plasminogen activators may prove helpful in increasing fibrinolysis during sepsis; because they have been associated with rebound thrombin generation, however, plasminogen activators may be most effective if used in conjunction with hirudin or a synthetic hirudin analogue. Bradykinin may offset hypotension in sepsis. Protein C may inhibit thrombin formation and also complex with plasminogen activator inhibitor 1, thereby promoting fibrinolysis. Other agents that may prove effective include alpha 1-antitrypsin Pittsburgh, C1-esterase inhibitor, monoclonal antibodies to contact factors, soybean trypsin inhibitors, thrombomodulin, prostaglandin I2, and aprotinin. There are no data to support the use of heparin or fibronectin, except in limited circumstances.
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PMID:Modulators of coagulation. A critical appraisal of their role in sepsis. 162 18

Knowledge of the role of high-molecular-weight kininogen (HK) in disease states has been limited by the lack of easy, reliable, and rapid assays for HK antigen. We have developed two immunochemical determinations, which use covalent coupling of the capture antibody, that will greatly facilitate the measurement of HK in plasma and cells. The first is an enzyme-linked immunosorbent assay (ELISA) that is performed in 96-well microplates and can be prepared up to 5 months in advance; it can, therefore, be available when needed. The second is a very rapid method that uses the technique known as particle concentration fluorescence immunoassay (PCFIA) and can be performed on 96 samples in less than 30 minutes. The HK-ELISA correlated well with HK coagulant activity in 22 normal donors (r = 0.88). The interassay coefficient of variation (CV) of 22 samples assayed on 5 separate days was 12%, whereas the interassay CV was 4%. The HK-PCFIA demonstrated an excellent correlation (r = 0.97) with HK coagulant activity in 22 normal donors, with an interassay CV of 7% and an intraassay CV of 1.5%. The HK ELISA was linear between 6 and 80 ng/ml, whereas the HK-PCFIA was linear between 5 and 800 ng/ml. Using the HK-PCFIA, we found a difference in HK antigen levels between two groups of patients with sepsis. The mean of those who survived (n = 10) was 70 micrograms/ml, whereas the mean of those who died (n = 6) was 48 micrograms/ml. Both HK-ELISA and HK-PCFIA were able to detect HK antigen in baboon plasma, enabling the monitoring of HK during experimental protocols. The HK-PCFIA was sensitive enough to detect HK antigen in the supernatant of hepatoma G2 at levels of 1 to 4 ng/ml. These assays should enable convenient and frequent measurement of HK antigen in various physiologic and pathophysiologic states, as well as in cell fractions.
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PMID:Sensitive antigenic determinations of high molecular weight kininogen performed by covalent coupling of capture antibody. 172 10

Patients treated with high doses of interleukin-2 (IL-2) because of cancer, develop hemodynamic and vasopermeability changes, that resemble those observed in sepsis. These patients thus provide a unique opportunity to study the early events in the development of septic shock. We analysed the changes that occurred in the contact system of coagulation in plasma from 4 patients, who together received seven 12-day cycles of high doses of IL-2. Levels of factor XII and prekallikrein during the cycles progressively fell to 50 and 30% of their initial levels, respectively, whereas significant increases in plasma factor XIIa- and kallikrein-C1-inhibitor complexes were not observed (in 3 out of 211 samples slightly increased levels of both complexes were found). The reductions in factor XII and prekallikrein were only in part due to protein leakage, since levels were still significantly lower, i.e., 80 and 50%, respectively, when corrected for albumin decreases. Levels of high molecular weight kininogen (HMWK) also decreased during IL-2 therapy, however, this decrease paralleled that of albumin. SDS-PAGE analysis of plasma HMWK did not reveal increased cleavage of this protein. The reduction of factor XII and prekallikrein, corrected for protein leakage, significantly correlated with albumin levels and inversely with daily cumulative weight gain in the patients. Thus, we demonstrate that factor XII and prekallikrein decrease during IL-2 therapy. As these decreases, already observed after 1 day treatment, were disproportional to that of albumin, a negative acute phase reactant, and correlated with signs of the vascular leak syndrome, we favor the explanation that they reflected activation rather than a decreased synthesis of the contact system proteins.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies on the contact system of coagulation during therapy with high doses of recombinant IL-2: implications for septic shock. 187 10

The plasma kallikrein-kinin system is activated in Gram-negative sepsis and typhoid fever, two diseases in which bacterial products have been shown to initiate inflammation. Because a single intraperitoneal injection of bacterial cell wall peptidoglycan-polysaccharide polymers from group A steptococci (PG-APS) into a Lewis rat produces a syndrome of relapsing polyarthritis and anemia, we investigated changes in the role of the kallikrein-kinin system in this model of inflammation. Coagulation studies after injection of PG-APS revealed an immediate and persistent decrease in prekallikrein levels. High-molecular-weight kininogen levels decreased significantly during the acute phase and correlated with the severity of arthritis. Factor XI levels were decreased only during the acute phase. Antithrombin III levels remained unchanged, indicating that neither decreased hepatic synthesis nor disseminated intravascular coagulation caused the decreased plasma contact factors. Plasma T-kininogen (an acute phase protein) was significantly elevated during the chronic phase. PG-APS failed to activate the contact system in vitro. Thus the kallikrein-kinin system plays an important role in this experimental model of inflammation, suggesting that activation of this system may play a role in the pathogenesis of inflammatory bowel disease and rheumatoid arthritis in which bacterial products might be etiologically important.
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PMID:Role of kallikrein-kinin system in pathogenesis of bacterial cell wall-induced inflammation. 199 42


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