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PubMed1991

Activation of human plasma prekallikrein by Pseudomonas aeruginosa elastase in vitro.

Human plasma prekallikrein, precursor of the bradykinin-generating enzyme, was activated in a purified system under a near physiological condition (pH 7.8, ionic strength I = 0.14, 37 degrees C) by Pseudomonas aeruginosa elastase which is a tissue-destructive metalloproteinase. Compared with that, Pseudomonas aeruginosa alkaline proteinase poorly activated it with a rate as low as less than one-twentieth of that of elastase. The activation by elastase was blocked with a specific inhibitor of elastase, HONHCOCH(CH2C6H5)CO-Ala-Gly-NH2 (10 microM). Generation of kallikrein-like amidolytic activity was also observed in plasma deficient in Hageman factor by treatment with elastase, but was not in plasma deficient in prekallikrein. The kallikrein-like activity generated in Hageman factor deficient plasma as well as the generation process itself was indeed inhibited by anti-human prekallikrein goat antibody. These results suggest that the pathological activation of the kallikrein-kinin system might occur under certain clinical conditions in pseudomonal infections.

Amino Acid Sequence↗
PubMed1981

Pseudo-factor-XI deficiency: effect of an inhibitor of factor XI adsorption to surface.

Recently we have described a normal plasma activity that modulates contact activation by inhibiting adsorption of factor XI to activating surfaces. Here we report the first identified case in which a patient has abnormal clotting tests due to an excess of a similar activity. The patient's plasma had a prolonged partial thromboplastin time and low apparent factor XI assay. His plasma prolonged the partial thromboplastin time of normal plasma and partially neutralized normal factor XI activity in vivo and in vitro. Analysis in dilute plasma revealed normal amounts of factor XI activity and antigen. Factor XI adsorption from plasma to activating surfaces was tested by adding a small amount of 125I-labeled purified factor XI to plasma, exposing the mixture to a glass tube or kaolin, and determining the amount of factor XI adsorbed to the surface. Whereas normal plasma and plasmas deficient in factor XII, factor XI, or Fletcher factor yielded about 4% adsorption to glass, factor XI adsorption from patient's plasma was less than 1%, indicating the presence of an adsorption inhibitor. This inhibitor did not affect factor XI activation or the activity of preformed factor XIa. It was not adsorbed by AI(OH)3 and was present in serum and the macroglobulin peak on gel filtration of the plasma through Sephadex G-200. The patient's history does not allow a definitive conclusion as to whether this inhibitor was associated with abnormal bleeding.

Adolescent↗
PubMed1989

[Physiopathology of kinin forming system in reproduction].

We studied contact factors and kinin-kallikrein in normal non-pregnant and pregnant women, FXII deficient toxemia and DIC. The results obtained are as follows: 1. The levels of plasma prekallikrein, high molecular weight kininogen, kallikrein inhibitor, and C-1 INA were gradually decreased at delivery, and the levels of kallikrein like activity and bradykinin were increased during pregnancy and at the time of parturition. These facts indicate that kinin kallikrein systems played important role in uterine contraction. 2. The levels of contact factors (FXII and FXI) were lower at delivery than those of term. 3. In rat uterus, specific binding of bradykinin was observed by the method of radio receptor assay in the pelet of 10,000 X g fetal membranes, and its activity was 38%. 4. A synthetic kallikrein inhibitor (OS-291, MS) and bradykinin antagonist inhibited completely spontaneous uterine contraction of Wistar rats during delivery. 5. In the case of FXII deficiency, the levels of plasma prekallikrein, high molecular weight kininogen were normal, but at delivery, these levels were lower than those of term. The levels of kallikrein like activity which was half of normal parturition level was increased at parturition. 6. In cases of DIC (17) and severe toxemia (22), plasma prekallikrein levels were lower than the normal controls. The decrease was due to consumption of plasma prekallikrein to kallikrein activation.

Animals↗
PubMed1985

Comparison of a chromogenic prothrombin time with clotting prothrombin time in the assessment of clinical coagulation deficiencies.

A chromogenic prothrombin time (CPT) has been compared with the standard prothrombin time (PT) or activated partial thromboplastin time (aPTT) in evaluating the hemostatic abnormality in patients with specific clotting factor deficiencies or liver disease and in patients receiving anticoagulant or fibrinolytic therapy. As expected, the CPT was sensitive to deficiencies of Factors II, V, X, and VII but was unaffected by deficiencies of Factors XII, XI, IX, or VIII. Due to the presence of polybrene in the thromboplastin formulation, the CPT was insensitive to heparin concentrations below 1 unit/mL. However, the assay result prolonged progressively between 1 and 10 units of heparin/mL, indicating that the CPT can be used to assay heparin concentrations within this range. Among patients with liver disease or who were receiving warfarin or fibrinolytic therapy, there was good correlation between the prolongation of the PT and the CPT. The results demonstrate that the CPT was sensitive to the commonly encountered clinical abnormalities in which the PT is prolonged and could be applied for monitoring oral anti-coagulant therapy. However, prolongation of the PT to a given value in different clinical conditions was associated with different degrees of prolongation of the CPT. This differential effect may reflect an abnormality in fibrinogen conversion to fibrin, which prolongs the PT but not the CPT and may also be contributed to by the differential sensitivity of the PT and CPT to specific factor deficiencies. The simplicity and reproducibility of the CPT warrant its further assessment, but correlation with the PT in a variety of clinical conditions is needed before clinical application can be undertaken.

Anticoagulants↗
PubMed1981

Contact activation of human plasma prorenin in vitro.

Acid activation of plasma prorenin occurs during dialysis to pH 3.3. and also during subsequent dialysis to pH 7.4. The latter, alkaline phase, involves Hageman factor-dependent formation of kallikrein, which in turn activates prorenin. The present study evaluates whether prorenin activation always occurs whenever kallikrein is activated in plasma. TAME esterase activity was used as a measure of plasma kallikrein activity an increase was observed during the alkaline phase of acid activation of prorenin. TAME esterase activity was absent when Hageman factor- or prekallikrein-deficient plasmas were similarly assayed and prorenin was not activated. Kaolin treatment of normal plasma rapidly increased TAME esterase activity at both 25 degrees and -4 degrees C, but no prorenin activation occurred. Similar changes in TAME esterase activity were observed in acid-treated plasma, in which setting prorenin was activated. No change in TAME esterase or renin activity occurred after addition of kaolin to acid-treated plasma deficient in Hageman factor; however, both enzymatic activities increased slightly in acidified prekallikrein-deficient plasma. Mixtures of these deficient plasmas exhibited normal kaolin activation of both TAME esterase and prorenin after acidification. Thus both Hageman factor and prekallikrein are needed for optimal contact activation of prorenin. These results demonstrate that prorenin activation does not always occur when active kallikrein is present in plasma. Prior acidification appears to be a prerequisite. Acidified prorenin may be more susceptible to cleavage; alternatively, competing substrates and/or inhibitors of kallikrein may be destroyed at acid pH, thereby permitting kallikrein to activate prorenin. Under normal conditions, activation of the plasma kallikrein-kinin system appears unlikely to result in activation of prorenin in vivo.

Dialysis↗
PubMed1977

Role of high-molecular-weight kininogen in surface-binding and activation of coagulation Factor XI and prekallikrein.

In the contact phase of activation of the kinin-forming, intrinsic clotting, and fibrinolytic systems, high-molecular-weight kininogen acts as a cofactor for the activation of Factor XI, prekallikrein, and Hageman factor. One mechanism by which high-molecular-weight kininogen acts as a cofactor has been studied by using 125I-labeled Factor XI and prekallikrein in kaolin-activated normal human plasma and plasmas deficient in high-molecular-weight kininogen and Hageman factor. High-molecular-weight kininogen was found to be essential for normal binding and cleavage of both Factor XI and prekallikrein on the kaolin surface. Hageman factor was essential for cleavage but not for binding of Factor XI and prekallikrein to kaolin. In normal plasma 80% of the activated Factor XI remained surface-bound, whereas 80% of the kallikrein was not surface-bound. These findings are consistent with the hypothesis that, in the initial phase of contact activation, high-molecular-weight kininogen links both Factor XI and prekallikrein to the exposed surface where they are activated by surface-bound activated Hageman factor. Once activated, the Factor XI molecules remain localized at the site of activation, in contrast to the kallikrein molecules which are found largely in the surrounding plasma.

Adult↗
PubMed1997

Mutations in the human factor XII gene.

The factor XII gene from 31 unrelated factor XII-deficient patients from Germany, Switzerland, and Austria was screened for mutations at the genomic level. Several novel mutations were detected and their absence in a control group of 74 healthy unrelated individuals was checked. Most changes are in the serine protease domain affecting the catalytic triad His-393-Asp-442-Ser-544; two missense mutations, R398Q (arginine 398 to glutamine; gene bank accession no. U71276) and L395M (leucine 395 to methionine; gene bank accession no. U71277), are close to the active site histidine at position 393. Another mutation detected in a cross-reacting material (CRM)-positive female with a history of three abortions affects the active site aspartic acid by changing it to asparagine (D442N; gene bank accession no. U71275). The novel mutation G570R (glycine 570 to arginine; gene bank accession no. U71274) giving rise to a CRM-positive phenotype is located next to Cys571, which forms a vital disulfide bridge. Two mutations are causing reading frame shifts: one single basepair deletion in exon 12 [exon 12: 10590(DelC); gene bank accession no. U71278] and one acceptor splice site mutation [exon 14: 11397(G --> A); gene bank accession no. L43615]. The putative regulatory mutation exon 1:-8 (g --> c) in the upstream region of the gene is associated with an aberrant Taq I restriction site allele in intron B of the gene (gene bank accession no. X80393).

Alleles↗
PubMed1979

Fujiwara trait: the first case of kininogen deficiency in Japan.

Asymptomatic identical twins were found to show the prolonged activated partial thromboplastin time, which was corrected by addition of normal, Hageman factor deficient or Fletcher trait plasma but not corrected by Fitzgerald or Williams plasma. The prolonged activated partial thromboplastin time was also corrected by addition of highly purified bovine high molecular weight kininogen but not by low molecular weight kininogen. When total kininogen was measured as the amount of bradykinin released by trypsin on acid treated plasma, only trace amount was detected in Fujiwara and Williams plasmas, although Fitzgerald plasma showed approximately 50% of the total kininogen of normal plasma level. Acetone-kaolin activated amidase activity of plasma kallikrein was not generated by Fujiwara plasma. Substitution with normal plasma in various ratios showed plasma kallikrein activity proportionally to the normal plasma contents. Extrapolation with the values at 120 min after activation gave the prekallikrein content of Fujiwara plasma as 30% of the normal value.

Diseases in Twins↗
PubMed1988

Cluster headache-like headache, Hageman trait deficiency, retrobulbar neuritis, and giant aneurysm. Autonomic function studies.

A 56-year-old, previously reported woman with cluster headache-like headache with bouts of unilateral (the side of predominance changing through the years) severe headache had a familial history (three generations) of partial Hageman factor deficiency and bleeding episodes. A giant aneurysm was found to be lodged in the anterior communicating artery on the left side. Clinically, the features were atypical for cluster headache: onset at a young age (14 years), episodes of retrobulbar neuritis appearing at the side of pain, etc. Studies of forehead sweating indicated that the right side was the pathologic one, from an autonomic point of view, as did pupillometric studies. However, during attacks, which were left-sided at the time, forehead sweating was marked laterally on the left side and on the upper eyelid, but not on the right. The "signal" usually reaching the autonomically stigmatized side during attacks of cluster headache, therefore, did not seem to reach the sweat glands on that (the right) side during the attack in the present case. This headache may, therefore, be distinct from cluster headache, both from a clinical and from an autonomic function point of view.

Autonomic Nervous System↗
PubMed1978

The "Hageman" connection: interrelationships of blood coagulation, fibrino(geno)lysis, kinin generation, and complement activation.

The activation pathways for the generation of enzymes involved in blood clotting, clot lysis, complement activation, and kinin generation are briefly reviewed. The interrelationship of the four systems is illustrated by the multiple functions of four key enzymes: Factor XIIa, kallikrein, plasmin, and C1 esterase. The pivotal role of Factor XIIa in establishing this connection is elucidated.

Blood Coagulation↗
PubMed1987

Isolation and properties of a capillary injury-related protease from lung lymph.

Lung microvascular injury induced in sheep by intravenous infusion of Escherichia coli endotoxin, oleic acid, or air emboli caused the appearance in lung lymph of high levels of a protease with trypsin-like activity. The enzyme was isolated as an apparently homogeneous protein from pooled samples of active lung lymph, after an almost 9000-fold purification by affinity chromatography on columns of Reactive Blue 2-agarose, aprotinin-agarose, and p-aminobenzamidine-agarose, and chromatography on a column of Sephadex G-100. A molecular weight of about 70,000 to 75,000 was determined from mobility in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The pH optimum was between 7.3 and 7.6. The isolated enzyme was quite labile, rapidly losing activity at both 37 and 25 degrees C. Addition of albumin to enzyme solutions protected against inactivation. Inhibition by diisopropylfluorophosphate and phenylmethanesulfonyl fluoride indicated that the enzyme belongs to the class of serine proteases. The enzyme cleaved peptide bonds on the carboxyl side of arginine residues and showed a relatively high affinity toward peptides containing several basic amino acid residues. Bonds involving the carboxyl group of lysine were cleaved at a much slower rate. The enzyme showed no plasminogen activator activity and its substrate specificity was quite different from that of several proteases of the clotting cascade. Its appearance in lymph was not influenced by lymph clotting and the isolated enzyme was not capable of correcting the clotting defect of plasmas deficient in factors XII, XI, IX, VII, and X.

Animals↗
PubMed1988

Rat paw edema induced by trimucase II, a kinin-releasing enzyme from Trimeresurus mucrosquamatus venom.

Trimucase II, a proteolytic enzyme isolated from Trimeresurus mucrosquamatus venom, caused rat hind-paw edema dose dependently. Captopril potentiated significantly, while pretreatment with cellulose sulfate suppressed the trimucase II-induced edematous response. Pretreatment with diphenhydramine and methysergide reduced by 42 and 46% the edema induced by trimucase II and kallikrein, respectively. The residual response was significantly further depressed by [Thi5,8,D-Phe7]bradykinin and trasylol. Kinin generation by trimucase II was also found in vitro from plasma and was concentration- and time-dependent. Kinin formation was inhibited by soybean trypsin inhibitor, trasylol and endogenous kininase. The kinins released were destroyed by chymotrypsin. Unlike cellulose sulfate, trimucase II caused kinin formation from Factor XII-deficient and prekallikrein-deficient plasma but not from high molecular weight kininogen-deficient plasma. These data indicate that, in addition to the mediators released from mast cells, kinins have an important role in the edema caused by trimucase II, and that kinins are released from plasma, probably due to direct activation of kininogen.

Animals↗
PubMed1990

Transfusion requirements in conservative nonoperative management of blunt splenic and hepatic injuries during childhood.

Nonoperative management of splenic and hepatic injuries in children is safe, and the majority of those with isolated injuries do not require blood transfusion. Thirty-seven children were treated for blunt splenic or hepatic trauma from November 1983 to September 1989. There was one death in a patient with a lethal head injury. No operations were performed on those with isolated splenic or hepatic injuries. Three of those with multiple injuries underwent delayed laparotomy. Two had perirenal and retroperitoneal hematomas without active bleeding, and one had a bowel obstruction secondary to an intramural jejunal hematoma. There were no late complications related to the splenic or hepatic injuries. Eight children (22%) required surgery for other injuries. Twelve children were not transfused, including the majority (8/11) of those with isolated splenic or hepatic injury. The hematocrit of four of these children fell to below 28% and this anemia was well-tolerated. Two children with bleeding disorders (factor VIII [antihemophilic factor] and factor XII [Hageman factor] deficiency) did not require packed red blood cells transfusion. Two clinically distinct groups of children received blood transfusions: (1) eight patients with multiple injuries were transfused during initial resuscitation when unstable or during early operation for other system trauma (mean, 62.0 mL blood/kg body weight); and (2) three hemodynamically stable patients with isolated injuries and 14 stable patients with multiple injuries were transfused empirically after initial resuscitation solely because of decreasing blood counts. They received an average of 16.5 and 21.1 mL blood/kg body weight, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidental Falls↗