Purification and cloning of a streptokinase from Streptococcus uberis. (1/634)

A bovine plasminogen activator was purified from the culture supernatant of the bovine pathogen Streptococcus uberis NCTC 3858. After the final reverse-phase high-performance liquid chromatography step a single protein with a molecular mass of 32 kDa was detected in the active fraction. A partial peptide map was established, and degenerate primers were designed and used for amplification of fragments of the gene encoding the activator. Inverse PCR was subsequently used for obtaining the full-length gene. The S. uberis plasminogen activator gene (skc) encodes a protein consisting of 286 amino acids including a signal peptide of 25 amino acids. In an amino acid sequence comparison the cloned activator showed an identity of approximately 26% to the streptokinases isolated from Streptococcus equisimilis and Streptococcus pyogenes. Interestingly, the activator from S. uberis was found to lack the C-terminal domain possessed by the streptokinase from S. equisimilis. This is apparently a general feature of the streptokinases of this species; biochemical and genetic analysis of 10 additional strains of S. uberis revealed that 9 of these were highly similar to strain NCTC 3858. Sequencing of the skc gene from three of these strains indicated that the amino acid sequence of the protein is highly conserved within the species.  (+info)

Expression and characterization of the intact N-terminal domain of streptokinase. (2/634)

Proteolytic studies have enabled two of the three putative domains of the fibrinolytic protein streptokinase to be isolated and characterized (Conejero-Lara F et al., 1996, Protein Sci 5:2583-2591). The N-terminal domain, however, could not be isolated in these experiments because of its susceptibility to proteolytic cleavage. To complete the biophysical characterization of the domain structure of streptokinase we have overexpressed, purified, and characterized the N-terminal region of the protein, residues 1-146. The results show this is cooperatively folded with secondary structure content and overall stability closely similar to those of the equivalent region in the intact protein.  (+info)

Low molecular weight heparin (dalteparin) as adjuvant treatment of thrombolysis in acute myocardial infarction--a pilot study: biochemical markers in acute coronary syndromes (BIOMACS II). (3/634)

OBJECTIVES: This randomized, double blind, placebo-controlled pilot trial evaluated the effect of dalteparin as an adjuvant to thrombolysis in patients with acute myocardial infarction regarding early reperfusion, recurrent ischemia and patency at 24 h. BACKGROUND: Low-molecular-weight heparin, given subcutaneously twice daily without monitoring, might be an attractive alternative to conventional intravenous heparin in the treatment of acute myocardial infarction. METHODS: In 101 patients dalteparin/placebo 100 IU/kg was given just before streptokinase and a second injection 120 IU/kg after 12 h. Monitoring with continuous vector-ECG was done to obtain signs of early reperfusion and later ischemic episodes. Blood samples for myoglobin were obtained at start and after 90 min to evaluate signs of reperfusion. Coronary angiography was performed after 20-28 h to evaluate TIMI-flow in the infarct-related artery. RESULTS: Dalteparin added to streptokinase tended to provide a higher rate of TIMI grade 3 flow in infarct-related artery compared to placebo, 68% versus 51% (p = 0.10). Dalteparin had no effects on noninvasive signs of early reperfusion. In patients with signs of early reperfusion, there seemed to be a higher rate of TIMI grade 3 flow, 74% versus 46% (myoglobin) (p = 0.04) and 73% versus 52% (vector-ECG) (p = 0.11). Ischemic episodes 6-24 h. after start of treatment were fewer in the dalteparin group, 16% versus 38% (p = 0.04). CONCLUSIONS: When dalteparin was added as an adjuvant to streptokinase and aspirin, there were tendencies for less ECG monitoring evidence of recurrent ischemia and better patency at 24 h, warranting further study.  (+info)

The rgg gene of Streptococcus pyogenes NZ131 positively influences extracellular SPE B production. (4/634)

Streptococcus pyogenes produces several extracellular proteins, including streptococcal erythrogenic toxin B (SPE B), also known as streptococcal pyrogenic exotoxin B and streptococcal proteinase. Several reports suggest that SPE B contributes to the virulence associated with S. pyogenes; however, little is known about its regulation. Nucleotide sequence data revealed the presence, upstream of the speB gene, of a gene, designated rgg, that was predicted to encode a polypeptide similar to previously described positive regulatory factors. The putative Rgg polypeptide of S. pyogenes NZ131 consisted of 280 amino acids and had a predicted molecular weight of 33,246. To assess the potential role of Rgg in the production of SPE B, the rgg gene was insertionally inactivated in S. pyogenes NZ131, which resulted in markedly decreased SPE B production, as determined both by immunoblotting and caseinolytic activity on agar plates. However, the production of other extracellular products, including streptolysin O, streptokinase, and DNase, was not affected. Complementation of the rgg mutant with an intact rgg gene copy in S. pyogenes NZ131 could restore SPE B production and confirmed that the rgg gene product is involved in the production of SPE B.  (+info)

Use of fibrinolytic agents in the management of complicated parapneumonic effusions and empyemas. (5/634)

BACKGROUND: Standard treatment for pleural infection includes catheter drainage and antibiotics. Tube drainage often fails if the fluid is loculated by fibrinous adhesions when surgical drainage is needed. Streptokinase may aid the process of pleural drainage, but there have been no controlled trials to assess its efficacy. METHODS: Twenty four patients with infected community acquired parapneumonic effusions were studied. All had either frankly purulent/culture or Gram stain positive pleural fluid (13 cases; 54%) or fluid which fulfilled the biochemical criteria for pleural infection. Fluid was drained with a 14F catheter. The antibiotics used were cefuroxime and metronidazole or were guided by culture. Subjects were randomly assigned to receive intrapleural streptokinase, 250,000 IU daily, or control saline flushes for three days. The primary end points related to the efficacy of pleural drainage--namely, the volume of pleural fluid drained and the chest radiographic response to treatment. Other end points were the number of pleural procedures needed and blood indices of inflammation. RESULTS: The streptokinase group drained more pleural fluid both during the days of streptokinase/control treatment (mean (SD) 391 (200) ml versus 124 (44) ml; difference 267 ml, 95% confidence interval (CI) 144 to 390; p < 0.001) and overall (2564 (1663) ml versus 1059 (502) ml; difference 1505 ml, 95% CI 465 to 2545; p < 0.01). They showed greater improvement on the chest radiograph at discharge, measured as the fall in the maximum dimension of the pleural collection (6.0 (2.7) cm versus 3.4 (2.7) cm; difference 2.9 cm, 95% CI 0.3 to 4.4; p < 0.05) and the overall reduction in pleural fluid collection size (p < 0.05, two tailed Fisher's exact test). Systemic fibrinolysis and bleeding complications did not occur. Surgery was required by three control patients but none in the streptokinase group. CONCLUSIONS: Intrapleural streptokinase probably aids the treatment of pleural infections by improving pleural drainage without causing systemic fibrinolysis or local haemorrhage.  (+info)

Empirical treatment with fibrinolysis and early surgery reduces the duration of hospitalization in pleural sepsis. (6/634)

The efficacy of three different treatment protocols was compared: 1) simple chest tube drainage (Drain); 2) adjunctive intrapleural streptokinase (IP-SK); and 3) an aggressive empirical approach incorporating SK and early surgical drainage (SK+early OP) in patients with pleural empyema and high-risk parapneumonic effusions. This was a nonrandomized, prospective, controlled time series study of 82 consecutive patients with community-acquired empyema (n=68) and high-risk parapneumonic effusions (n=14). The following three treatment protocols were administered in sequence over 6 years: 1) Drain (n=29, chest catheter drainage); 2) IP-SK (n=23, adjunctive intrapleural fibrinolysis with 250,000 U x day(-1) SK); and 3) SK+early OP (n=30, early surgical drainage was offered to patients who failed to respond promptly following initial drainage plus SK). The average duration of hospital stay in the SK+early OP group was significantly shorter than in the Drain and IP-SK groups. The mortality rate was also significantly lower in the SK+early OP than the Drain groups (3 versus 24%). It was concluded that an empirical treatment strategy which combines adjunctive intrapleural fibrinolysis with early surgical intervention results in shorter hospital stays and may reduce mortality in patients with pleural sepsis.  (+info)

Intrapericardial streptokinase in purulent pericarditis. (7/634)

Six consecutive children with proven purulent pericarditis were treated with pericardial irrigation with streptokinase. Mean (SD) 861 (678) ml (range 240-2000) of thick purulent fluid was drained, and five children had complete clearance of the pus within 3-8 days. One child developed intrapericardial haemorrhage with a submitral pseudoaneurysm and underwent patch closure of the neck of the aneurysm as well as anterior pericardiectomy. Follow up of 13 to 30 months revealed no pericardial constriction.  (+info)

Sustained benefit at 10-14 years follow-up after thrombolytic therapy in myocardial infarction. (8/634)

AIMS: To investigate whether the benefit of thrombolytic therapy was sustained beyond the first decade. We report the 10-14 year outcome of 533 patients who were randomized to treatment with intracoronary streptokinase or to conventional therapy during the years 1980-1985. METHODS AND RESULTS: Details of survival and cardiac events were obtained from the civil registry, from medical records or from the patient's physician. At follow-up, 158 patients (59%) of the 269 patients allocated to thrombolytic treatment and only 129 patients (49%) of the 264 conventionally treated patients were alive. The cumulative 1-, 5- and 10-year survival rates were 91%, 81% and 69% in patients treated with streptokinase and 84%, 71% and 59% in the control group, respectively (P=0.02). Reinfarction during 10-years of follow-up was more frequent after thrombolytic therapy, particularly during the first year. Coronary bypass surgery and coronary angioplasty were more frequently performed after thrombolytic therapy. At 10 years approximately 30% of the patients were free from subsequent cardiac events. Independent determinants of mortality were elderly age, indicators of impaired residual left ventricular function, multivessel disease and an inability to perform an exercise test at the time of hospital discharge. CONCLUSION: Improved survival after thrombolytic therapy is maintained beyond the first decade. Age, left ventricular function, multivessel disease and an inability to perform an exercise test were independent predictors for long-term mortality, as they are predictors for early mortality.  (+info)

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