Thrombolytic therapy

External validation and comparison of MBE, EDEMA, and modified EDEMA scores for predicting malignant cerebral EDEMA in Chinese patients with large hemispheric infarction patients without revascularization

BACKGROUND

Malignant cerebral edema (MCE) is a severe condition characterized by rapid neurological deterioration and a potentially poor prognosis. Scoring systems including the malignant brain edema (MBE) score, Enhanced Detection of Edema in Malignant Anterior Circulation Stroke score (EDEMA), and modified EDEMA score, have been developed to predict MCE in patients with large hemispheric infarction (LHI). We aimed to externally validate and comparethe predictive efficacy of these scores in LHI patients within 48 h of onset and not undergoing reperfusion therapy.

METHODS

Demographic, clinical and radiological data were retrospectively collected from LHI patients within 48 h of onset and not receiving reperfusion therapy. Patients were divided into MCE and non-MCE group. The calibration, discrimination, and clinical practicability of the three scores were verified using Hosmer-Lemeshow goodness-of-fit test, receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA), respectively. Finally, continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were applied to determine the discrimination performance of the three scores.

RESULTS

A total of 314 patients were included in the study, with 122 cases being MCE patients. The Hosmer-Lemeshow goodness-of-fit test showed excellent fitting ability across the MBE (p = 0.36), EDEMA (p = 0.61), and modified EDEMA scores (p = 0.62) in our patients. The MBE, EDEMA, and modified EDEMA scores had the AUCs of 0.855 (95 % CI 0.818-0.898), 0.782 (95 % CI 0.727-0.837) and 0.878 (95 % CI 0.844-0.919) respectively. The MBE (NRI, 0.33; 95 % CI, 0.11-0.56, p = 0.003 and IDI, 0.11; 95 % CI, 0.03-0.18; p = 0.004) and modified EDEMA scores (NRI, 1.10; 95 % CI, 0.94-1.26; p < 0.001 and IDI, 0.17; 95 % CI, 0.13-0.20, p < 0.001) showed better performance than the EDEMA score. DCA demonstrated that the modified EDEMA score outperformed the other two scores, possessing heightened clinical usefulness.

CONCLUSIONS

The MBE, EDEMA, and modified EDEMA scores for predicting MCE are also applicable in non-revascularization LHI patients within 48 h of onset. Both the MBE and modified EDEMA scores demonstrated higher predictive validity as predictive tools for MCE in LHI patients than the EDEMA score. Furthermore, the modified EDEMA score could be a suitable prediction tool in Chinese patients for its excellent clinical utility.

Thrombolytic Potential of Micromycetes from the Genus Tolypocladium, Obtained from White Sea Soils: Screening of Producers and Exoproteinases Properties

Thrombotherapy is an important approach in treatment of various diseases associated with pathologies of the cardiovascular and human hemostasis systems. Screening for producers of modern, specific, and safe thrombolytic substances is an important task for medicine and biotechnology. The aim of this study was to characterize thrombolytic potential of seven strains of micromycete belonging to the genus Tolypocladium, which was obtained from White Sea soils. The Tolypocladium inflatum 62a strain was considered the most promising producer of thrombolytic agent activities suitable for possible use in thrombotherapy or diagnostics of hemostasis pathologies. It demonstrated a high radial growth rate and was characterized not only by a sufficiently high value of enzymatic index in media with fibrin and fibrinogen but also by the highest specificity for fibrillar proteins among all strains. The preparation obtained from it demonstrated pronounced thrombolytic effectiveness and substrate specificity.

Alteplase or tenecteplase for thrombolysis in ischemic stroke: An illustrated review

Intravenous thrombolysis is a standard of care treatment for patients with acute ischemic stroke. Tissue plasminogen activator (tPA) has been the main thrombolytic agent used since the publication of the seminal National Institutes of Neurological Disorders and Stroke trial in 1995. There is now mounting evidence to support the routine use of Tenecteplase (TNK) to treat acute ischemic stroke. TNK is a genetically modified tPA with higher fibrin specificity, longer half-life, and reduced systemic coagulopathy. In this illustrated review, we compare the indications, doses, mechanisms of action, efficacy and safety of TNK and tPA. We provide an overview of published clinical trials studying TNK in acute ischemic stroke, including dose-escalation studies and head-to-head comparisons with tPA. Finally, we summarize current acute stroke guideline recommendations and suggest treatment algorithms to manage the two main complications of intravenous thrombolysis: symptomatic intracerebral hemorrhage and angioedema.

Isolation and characterization of two new non-hemorrhagic metalloproteinases with fibrinogenolytic activity from the mapanare (Bothrops colombiensis) venom

Colombienases are acidic, low molecular weight metalloproteinases (Mr of 23,074.31 Da colombienase-1 and 23,078.80 Da colombienase-2; pI of 6.0 and 6.2, respectively) isolated from Bothrops colombiensis snake venom. The chromatographic profile in RP-HPLC and its partial sequence confirmed its high homogeneity. Both colombienases present fibrino(geno)lytic activity, but did not show any hemorrhagic, amidolytic, plasminogen activator or coagulant activities, and no effect on platelet aggregation induced by collagen or ADP. Both enzymes were strongly active on fibrinogen Aα chains followed by the Bβ chains, and colombienases-2, at high doses, also degraded the γ chains. This activity was stable at temperatures ranging between 4 and 37 °C, with a maximum activity at 25 °C, and at pHs between 7 and 9. The homology demonstrated by the comparison of sequences, with zinc-dependent metalloproteinases, as well as the metal chelant effects on, confirmed that the colombienases were metalloproteinases, particularly to α-fibrinogenases belonging to the P-I class of SVPMs (20-30 kDa), which contain only the single-domain proteins. The biological characteristics of the colombienases confer a therapeutic potential, since they contain a high fibrino(geno)lytic activity, devoid of hemorrhagic activity. These metalloproteinases might be explored as thrombolytic agents given that they dissolve fibrin clots or prevent their formation.

Inflammatory bowel disease-associated thromboembolism: a systematic review of outcomes with anticoagulation versus catheter-directed thrombolysis

BACKGROUND

Thromboembolism (TE) is a common extraintestinal complication of inflammatory bowel disease (IBD). Catheter-directed thrombolysis (CDT) is being increasingly used to treat TE but often evokes fears of hemorrhagic complications (HCs) in patients with IBD. We reviewed clinical outcomes with anticoagulation (AC) and CDT in IBD patients with TE.

METHODS

Published cases of IBD patients with TE were identified by a PubMed search. Cases were divided into two groups based on treatment modality: AC alone or CDT. Pretreatment variables and treatment-related outcomes were compared between treatment groups.

RESULTS

Fifty-two cases of IBD-associated TE were identified. Thirty-five cases were treated with AC alone and 17 with CDT. There were no significant differences in pretreatment variables. Patients treated with CDT tended to be more likely to achieve complete or partial symptomatic (P = 0.02) and radiologic resolution (P = 0.06). Gastrointestinal (GI) and non-GI HCs tended to occur more frequently with CDT, although these differences were not statistically significant (P = 0.44 and 0.15, respectively).

CONCLUSIONS

CDT and AC both appear to be well tolerated by IBD patients with TE. CDT may be used preferentially in patients with life-threatening TE, while AC may be preferable in patients with less clinically significant TE or patients at higher risk for bleeding. Further prospective studies are warranted to confirm these results and more definitively identify the best therapeutic approach for patients with IBD-associated TE.

Local thrombolysis: a newer approach to treating inflammatory bowel disease-related thromboembolism

GOALS

To review the experience with a relatively novel treatment, local thrombolysis, in patients with inflammatory bowel disease (IBD)-related thromboembolism (TE).

BACKGROUND

TE is an extraintestinal complication of IBD for which there are no clear treatment guidelines. Systemic treatment with anticoagulants or thrombolytics often raises fear of hemorrhagic complications, particularly hematochezia.

STUDY

Cases of IBD-related and non-IBD-related TE treated with local thrombolysis were searched for in PubMed, reviewed, and grouped into anatomic areas. Outcomes in each anatomic area were compared between IBD and non-IBD patients. Due to the small number of IBD-related TE cases, a descriptive, not statistical, analysis was performed.

RESULTS

There were 17 cases of IBD-related TE treated with local thrombolysis grouped as follows: 7 of cerebral venous thrombosis, 3 of lower extremity arterial TE, 1 of deep vein thrombosis, 1 of upper extremity deep vein thrombosis, 3 of abdominal vein thrombosis, and 2 of inferior vena cava TE. Mean age was 32 (range, 14 to 50) years, and 13 of 17 patients were female. Twelve had ulcerative colitis, 3 had Crohn's disease, and 1 was indeterminate. Four of the 7 patients with active IBD had pretreatment hematochezia, 2 of whom had worsening of hematochezia secondary to treatment. The rates of radiologic resolution, clinical resolution, and hemorrhagic complications in the IBD patients were favorable in all the anatomic areas and were very similar to non-IBD patients.

CONCLUSIONS

Local thrombolysis may be considered a viable therapeutic option for IBD-related TE. As more cases of local thrombolysis for IBD-related TE accumulate, further recommendations can be made as to the indications for its use.

Purification and characterization of a fibrinolytic subtilisin-like protease of Bacillus subtilis TP-6 from an Indonesian fermented soybean, Tempeh

We have isolated a bacterium (TP-6) from the Indonesian fermented soybean, Tempeh, which produces a strong fibrinolytic protease and was identified as Bacillus subtilis. The protease (TPase) was purified to homogeneity by ammonium sulfate fractionation and octyl sepharose and SP sepharose chromatography. The N-terminal amino acid sequence of the 27.5 kDa enzyme was determined, and the encoding gene was cloned and sequenced. The result demonstrates that TPase is a serine protease of the subtilisin family consisting of 275 amino acid residues in its mature form. Its apparent K (m) and V (max) for the synthetic substrate N-succinyl-Ala-Ala-Pro-Phe-pNA were 259 microM and 145 micromol mg(-1) min(-1), respectively. The fibrinogen degradation pattern generated by TPase as a function of time was similar to that obtained with plasmin. In addition, N-terminal amino acid sequence analysis of the fibrinogen degradation products demonstrated that TPase cleaves Glu (or Asp) near hydrophobic acids as a P1 site in the alpha- and beta-chains of fibrinogen to generate fragments D', E', and D' similar to those generated by plasmin. On plasminogen-rich fibrin plates, TPase did not seem to activate fibrin clot lysis. Moreover, the enzyme converted the active plasminogen activator inhibitor-1 to the latent form.

Venous Thrombolysis: Current Perspectives

Venous thromboembolism is a common problem in hospital and community patients and is associated with longer hospital stays, significant morbidity, and mortality. It is the third most common cardiovascular disease after ischemic coronary artery disease and stroke. A quarter of patients with acute myocardial infarction and more than half of patients with acute ischemic stroke may develop venous thromboembolism. The traditional treatment of venous thrombosis has been with anticoagulation, initially with heparin, followed by warfarin long term. The concept of thrombolysis for venous thrombosis is relatively new, but its exact role remains unsettled and largely unexplored. Reports of catheter fragmentation with systemic thrombolysis as well as catheter-directed thrombolysis are promising, and groups of patients who would benefit from thrombolytic therapy as the primary treatment are now being identified.