Streptokinase reduces Streptococcus dysgalactiae subsp. equisimilis biofilm formation.

BACKGROUND: Streptococcus dysgalactiae subspecies equisimilis (SDSE) is increasingly recognized as an emerging cause of invasive diseases including necrotizing soft tissue infections (NSTIs). In contrast to the closely related Streptococcus pyogenes, SDSE infections mainly affect older and comorbid patients. Biofilm formation has been demonstrated in soft tissue biopsies of S. pyogenes NSTI cases. RESULTS: Here, we show that bacterial aggregations indicative of biofilms are also present in SDSE NSTI. Although streptokinase (Ska) activity and biofilm formation did not correlate in a diverse set of clinical SDSE isolates, addition of exogenous Ska at an early time point prevented biofilm formation for selected strains. Deletion of ska in SDSE S118 strain resulted in increased biofilm forming capacity. Ska-deficient mutant strain was characterized by a higher metabolic activity and consequent metabolome profiling of biofilms identified higher deposition of a wide range of metabolites as compared to the wild-type. CONCLUSIONS: Our results argue that Ska suppresses biofilm formation in SDSE independent of its original plasminogen converting activity. However, the impact of biofilms and its consequences for patient outcomes in streptococcal NSTIs remain to be elucidated.

Guillain-Barre syndrome after myocardial infarction: a case report and literature review.

BACKGROUND: Guillain-Barre syndrome after myocardial infarction occurs infrequently, and its occurrence following percutaneous coronary intervention is extremely rare. Due to the high mortality rate of myocardial infarction and the disability of Guillain-Barre syndrome, early identification of Guillain-Barre syndrome after myocardial infarction and early intervention can decrease the mortality rate, lead to early recovery, and provide a better outcome. CASE PRESENTATION: Herein, we reported a rare case of Guillain-Barre syndrome after myocardial infarction treated with percutaneous coronary intervention. The patient was a 75-year-old woman from China who was admitted to hospital due to sudden loss of consciousness. Electrocardiography showed acute myocardial infarction in the right ventricle and inferior and posterior walls. The patient underwent emergency percutaneous intervention of the posterior collateral artery of the right coronary artery. Soon after, her condition worsened resulting in limb weakness and numbness. Unfortunately, she continued to develop respiratory failure, and treated with intravenous immunoglobulin and ventilator-assisted breathing. A physical examination showed hypotonia of all four limbs, complete quadriplegia, bulbar palsy, dysarthria, and tendon areflexia. Serum immunoglobulin (Ig) G anti-ganglioside antibody analysis was positive with anti-GT1a antibodies (+ +), anti-GM1 antibodies ( +), anti-GM2 antibodies ( +), and anti-GM4 antibodies ( +), and he was diagnosed with Guillain-Barre syndrome after myocardial infarction. She was discharged due to poor response to treatment. The patient died two days after being discharged. CONCLUSIONS: Myocardial infarction and/or percutaneous coronary intervention may activate immune-mediated response and cause severe complications. Clinician should be alert to Guillain-Barre syndrome after myocardial infarction and/or percutaneous coronary intervention.

The Inhibitory Effects of Amylase and Streptokinase on Minimum Inhibitory Concentration of Antibiotics Used to Treat Gram Negative Bacteria Biofilm Infection on Indwelling Devices.

The study evaluated and compared the effect of adding streptokinase and amylase to antibiotics that are already used in clinical practice to treat Gram negative bacteria biofilm infection on indwelling devices on the antibiotics' minimum inhibitory concentration (MIC). 24 h-old biofilms were developed on 96-well plate with eight clinical isolates. MIC of amikacin, cefepime, ceftazidime, colistin, meropenem, and piperacillin-tazobactam, on biofilms were measured before and after the addition of 25 U/ml streptokinase and 25 µg/ml amylase with microplate reader. The addition of streptokinase reduces the MICs of cefepime, ceftazidime, colistin, meropenem from (16, 16, 8, 4 µg/ml) to (8, 1, 1, 0.5 µg/ml) in Escherichia coli (isolate 1). While the addition of amylase reduces the MICs of only cefepime, ceftazidime from (16, 16 µg/ml) to (2, 4 µg/ml) in E. coli (isolate 1). In Pseudomonas aeruginosa (isolate 4), the MICs of amikacin, cefepime, ceftazidime, colistin and meropenem (64, 16, 32, 4, 32 µg/ml) reduced to (2, 1, 0.5, 0.25, 0.5 µg/ml) with streptokinase and (4, 4, 4, 2, 0.5 µg/ml) with amylase respectively. Similar inhibitions were seen in Pseudomonas putida, Proteus mirabilis. We can conclude that the addition of streptokinase and amylase were effective in reducing the MICs of antibiotics that are commonly used to treat Gram negative bacteria biofilm infection on indwelling devices, thereby increasing susceptibility of bacteria to antibiotics. Streptokinase obviously had a greater effect than amylase, implying that it should be prioritized in future in vivo and clinical studies to obtain successful therapy with antibiotics on biofilm infections.

Streptococcus co-opts a conformational lock in human plasminogen to facilitate streptokinase cleavage and bacterial virulence.

Virulent strains of Streptococcus pyogenes (gram-positive group A Streptococcus pyogenes [GAS]) recruit host single-chain human plasminogen (hPg) to the cell surface-where in the case of Pattern D strains of GAS, hPg binds directly to the cells through a surface receptor, plasminogen-binding group A streptococcal M-protein (PAM). The coinherited Pattern D GAS-secreted streptokinase (SK2b) then accelerates cleavage of hPg at the R561-V562 peptide bond, resulting in the disulfide-linked two-chain protease, human plasmin (hPm). hPm localizes on the bacterial surface, assisting bacterial dissemination via proteolysis of host defense proteins. Studies using isolated domains from PAM and hPg revealed that the A-domain of PAM binds to the hPg kringle-2 module (K2hPg), but how this relates to the function of the full-length proteins is unclear. Herein, we use intact proteins to show that the lysine-binding site of K2hPg is a major determinant of the activation-resistant T-conformation of hPg. The binding of PAM to the lysine-binding site of K2hPg relaxes the conformation of hPg, leading to a greatly enhanced activation rate of hPg by SK2b. Domain swapping between hPg and mouse Pg emphasizes the importance of the Pg latent heavy chain (residues 1-561) in PAM binding and shows that while SK2b binds to both hPg and mouse Pg, the activation properties of streptokinase are strictly attributed to the serine protease domain (residues 562-791) of hPg. Overall, these data show that native hPg is locked in an activation-resistant conformation that is relaxed upon its direct binding to PAM, allowing hPm to form and provide GAS cells with a proteolytic surface.

Assessing the Efficacy and Outcomes Following Irrigation with Streptokinase Versus Hydrogen Peroxide in Necrotizing Pancreatitis: A Randomized Pilot Study.

BACKGROUND: Percutaneous catheter drainage (PCD's) are prone to blockage because of necrosum. To improve the efficacy of PCD, necrolytic agents have been used. The present study compared the use of Streptokinase with H2O2 in saline irrigation. MATERIALS AND METHODS: This is a single-center randomized pilot study (from July 2018 to Dec 2019). Patients with infected pancreatic necrosis not showing response to PCD and saline irrigation were included in the study. Patients received either Streptokinase (Streptokinase group 50,000 IU in 100 ml normal saline) or 3% H2O2 (3% H2O2 in 100 ml normal saline in 1:10 dilution). Primary endpoints were the need for surgery and mortality while secondary endpoints were hospital stay and complications attributable to necrolytic agents. RESULTS: There were 30 patients in the study, 15 in each arm. Organ failure was seen in 23 (76.6%), single organ failure was present in 11 (47%), and multi-organ failure in 12 (53%). Bleeding complications (20% in H2O2 vs 6.6% in Streptokinase), need for surgery (73% in H2O2 vs 33.3% in Streptokinase) and mortality (60% in H2O2 vs 33% in Streptokinase) were higher in H2O2 group but the difference was not significant statistically. Post-irrigation hospital stay was lesser in the Streptokinase group compared to H2O2 group but the difference did not reach statistical significance (14.1 ± 7.7 vs 19.2 ± 11.7, p = 0.09) CONCLUSIONS: Streptokinase irrigation led to a trend for reduced need for necrosectomy and mortality. H2O2 group had more bleeding complications. Post-irrigation hospital stay was lesser in Streptokinase group.

Fibrinspecific liposomes as a potential method of delivery of the thrombolytic preparation streptokinase.

The use of streptokinase (SK) in the clinic is limited by the lack of fibrin-specificity and the short half-life of the drug. We have developed a new dosage form of streptokinase (immunoliposome), which consists of "free" native streptokinase and "bound" encapsulated in liposomes conjugated through carboxylated dextran with fibrin-specific monoclonal antibodies FnI-3C (IgG2 class), in a ratio of 60 and 40%, respectively, and studied their physicochemical properties, pharmacokinetic parameters, and the ability of fibrin-specific liposomes with SK for targeted delivery to fibrin in an in vivo experiment. The obtained immunoliposomes had a hydrodynamic diameter of ~ 140 nm, a zeta potential of - 19.6 mV, and entrapment efficiency of 14.1%. Fluorescent labels bound to immunoliposomes with streptokinase selectively accumulated in model rat vein thrombi at sites containing fibrin in 30 min after injection. Studies of pharmacokinetic parameters showed that the administration of immunoliposomes with streptokinase to rats was accompanied by an increase in the half-life from 1.8 to 24.1 min, the time to reach the maximum concentration from 15 to 30 min, and a decrease in the elimination constant by about 13 times compared with the native streptokinase preparation. Further studies are needed to evaluate the thrombolytic efficacy a new dosage form of streptokinase in experiment in vivo.

Impact of COVID-19 pandemic on STEMI thrombolysis and Emergency Department's performance in a non-PCI capable tertiary hospital.

INTRODUCTION: Some guidelines had recommended "thrombolysis first" in ST-elevated myocardial infarction (STEMI) during the Coronavirus Disease 2019 (COVID-19) outbreak. The impact of COVID-19 solely on STEMI thrombolysis is lacking as most studies reported outcomes related to percutaneous coronary intervention (PCI) setting. Thus, this study aimed to assess the impact of the COVID-19 pandemic on STEMI thrombolysis outcomes and the Emergency Department's performance in a non-PCI capable centre. METHODS: This single-centre retrospective study analysed data on consecutive STEMI patients who received thrombolytic therapy from May 2019 to December 2020 (20 months) in a non-PCI capable tertiary hospital. Total population sampling was used in this study. We compared all patients' characteristics and outcomes ten months before and during the pandemic. Regression models were used to assess the impact of COVID-19 pandemic on door-to-needle time (DNT), mortality, bleeding events, and the number of overnight stays. RESULTS AND DISCUSSION: We analysed 323 patients with a mean age of 52.9 ± 12.9 years and were predominantly male (n = 280, 88.9%). There was a 12.5% reduction in thrombolysis performed during the pandemic. No significant difference in timing from symptoms onset to thrombolysis and DNT was observed. In-hospital mortality was significantly higher during the pandemic (OR 2.02, 95% CI 1.02-4.00, p = 0.044). Bleeding events post thrombolysis remained stable and there was no significant difference in the number of overnight stays during the pandemic. CONCLUSION: STEMI thrombolysis cases were reduced during the COVID-19 pandemic, with an inverse increase in mortality despite the preserved Emergency Department performance in timely thrombolysis.

The Benefits of Fibrinolysis Combined with Venous Systemic Oxygen Persufflation (VSOP) in a Rat Model of Donation after Circulatory Death and Orthotopic Liver Transplantation.

Organ shortage has led to the increasing utilization of livers retrieved from donors after circulatory death (DCD). These pre-damaged organs are susceptible to further warm ischemia and exhibit minimal tolerance for cold storage. The aim was thus to examine the effects of fibrinolysis combined with Venous Systemic Oxygen Persufflation (VSOP) on the preservation of DCD livers in vivo. Livers of male Lewis rats were explanted after 45 min of warm ischemia, cold-stored for 18 h, and transplanted into a recipient animal. Livers were left untreated or underwent either VSOP or fibrinolysis via Streptokinase (SK) or received combined SK and VSOP. Combined treatment exhibited improved microvascular flow at 168 h (p = 0.0009) and elevated microperfusion velocity at 24 h post-transplantation (p = 0.0007). Combination treatment demonstrated increased portal venous flow (PVF) at 3 and 24 h post-transplantation (p = 0.0004, p < 0.0001), although SK and VSOP analogously achieved increases at 24 h (p = 0.0036, p = 0.0051). Enzyme release was decreased for combination treatment (p = 0.0002, p = 0.0223) and lactate dehydrogenase (LDH) measurements were lower at 24 h post-transplantation (p = 0.0287). Further supporting findings have been obtained in terms of serum cytokine levels and in the alterations of endothelial injury markers. The combination treatment of SK + VSOP might provide improved organ integrity and viability and may therefore warrant further investigation as a potential therapeutic approach in the clinical setting of DCD.

Exogenous activation and inhibition of plasminogen/plasmin activity during in vitro maturation of bovine cumulus-oocyte complexes: A biological and spectroscopic approach.

This study deals with the effect of plasminogen/plasmin on the in vitro maturation (IVM) of bovine cumulus-oocyte complexes (COCs). Exogenous plasminogen activator streptokinase (SK) added to the IVM medium revealed similar values of cumulus expansion and oocyte nuclear maturation compared to controls (standard IVM medium). However, a decrease in both determinations was observed in COCs matured with the supplementation of ɛ-aminocaproic acid (ɛ-ACA), a specific plasmin inhibitor. After in vitro fertilization, no differences were observed in either cleavage or blastocyst rates between SK and control groups; however, ε-ACA treatment caused a decrease in both developmental rates. Zona pellucida (ZP) digestion time decreased in the SK group while it increased in the ε-ACA group. Raman microspectroscopy revealed an increase in the intensity of the band corresponding to the glycerol group of sialic acid in the ZP of oocytes matured with SK, whereas ZP spectra of oocytes treated with ɛ-ACA presented similarities with immature oocytes. The results indicate that although treatment with SK did not alter oocyte developmental competence, it induced modifications in the ZP of oocytes that could modify the folding of glycoproteins. Plasmin inhibition impairs oocyte maturation and has an impact on embryo development, thus evidencing the importance of this protease during IVM.

Kringles of substrate plasminogen provide a 'catalytic switch' in plasminogen to plasmin turnover by Streptokinase.

To understand the role of substrate plasminogen kringles in its differential catalytic processing by the streptokinase - human plasmin (SK-HPN) activator enzyme, Fluorescence Resonance Energy Transfer (FRET) model was generated between the donor labeled activator enzyme and the acceptor labeled substrate plasminogen (for both kringle rich Lys plasminogen - LysPG, and kringle less microplasminogen - µPG as substrates). Different steps of plasminogen to plasmin catalysis i.e. substrate plasminogen docking to scissile peptide bond cleavage, chemical transformation into proteolytically active product, and the decoupling of the nascent product from the SK-HPN activator enzyme were segregated selectively using (1) FRET signal as a proximity sensor to score the interactions between the substrate and the activator during the cycle of catalysis, (2) active site titration studies and (3) kinetics of peptide bond cleavage in the substrate. Remarkably, active site titration studies and the kinetics of peptide bond cleavage have shown that post docking chemical transformation of the substrate into the product is independent of kringles adjacent to the catalytic domain (CD). Stopped-flow based rapid mixing experiments for kringle rich and kringle less substrate plasminogen derivatives under substrate saturating and single cycle turnover conditions have shown that the presence of kringle domains adjacent to the CD in the macromolecular substrate contributes by selectively speeding up the final step, namely the product release/expulsion step of catalysis by the streptokinase-plasmin(ogen) activator enzyme.

Study of Aqueous Ecballium Elaterium as Fibrinolytic in The Rabbit Model of Intrapleural Empyema.

AIMS: We aimed to investigate of intrapleural use of ecballium elaterium (EE) in a rabbit model empyema. METHODS: An empyema was induced in 21 rabbits after inoculation of Staphylococcus aureus. Glucose levels, pH, lactate dehydrogenase levels, and amounts of pleural drainage were evaluated in addition to pleural and empyema scores. The rabbits were divided into three groups, each 7, the isotonic solution, the streptokinase, and the ecballium group. RESULTS: At autopsy, there was no difference in pH, glucose, and LDH levels in three groups. The mean pleural drainage was greater in the ecballium group. A significant difference was detected between groups in terms of drainage amounts and pleural and empyema scores (P < 0.05). A significant difference in pleural and empyema scores was detected in the ecballium and streptokinase groups (P < 0.05). EE group had significant differences in drainage amounts and plural and empyema scores regard to the control group (P < 0.05). No significance was found between streptokinase and EE groups. CONCLUSION: We conclude that intrapleural use of EE is at least as effective as streptokinase for the treatment of empyema.

In silico design and in vitro validation of a novel PCR-RFLP assay for determination of phylogenetic clusters of streptokinase gene alleles in streptococci groups.

Streptokinase (SK), a heterogeneous plasminogen (Pg) activator protein secreted by groups A, C and G streptococci (GAS/GCS/GGS) is a virulence factor composed of three structural domains; SKα/SKß/SKγ. Phylogenetic analysis of the major variable region of SKß (sk-V1; nucleotides 448-791; 343bp) which classifies the SK alleles into SK1/SK2 clusters and SK2a/SK2b sub-clusters, is an approved assay to categorize clinical/natural streptococcal-isolates into co-related functional/pathogenesis groups. Herein, we describe a novel PCR-RFLP assay that in combination with Numerical Taxonomy and multivariate analysis System (NTSYS) resulted to dendrograms with complete adaption to that of the phylogenetic analysis of sk-V1-based clustering. In silico analyses by 30 restriction enzymes on GenBank-acquired sk-V1 sequences of known streptococcal clusters, resulted to the selection of "BsrI, MseI and Tsp45I″ enzymes that produced proper patterns to construct the expected dendrograms. In vitro analysis of the selected enzymes on clinical isolates of GAS/GCS/GGS validated the production of the same in silico-observed digestion patterns. Comparison of the constructed dendrogram and phylogenetic trees of selected GenBank and clinical isolates of streptococci indicated complete adaptation. Assessment of Pg-activation activity in selected clinical isolates indicated the expected co-related functionalities of the classified SK-clusters by the invented PCR-RFLP/NTSYS method. The simplicity of the assay relieves the need of sequencing/phylogenetic analyses for SK-clustering.

Comparison of QT dispersion in patients with ST elevation acute myocardial infarction (STEMI) before and after treatment by streptokinase versus primary percutaneous coronary intervention (PCI).

BACKGROUND: QT dispersion (QTD) represents inhomogeneous ventricular repolarization such that an increased QTD may predispose the heart to malignant ventricular arrhythmias (VAs). This study was conducted to compare QTD in patients with ST-elevation myocardial infarction (STEMI) before and after treatment by streptokinase (SK) versus primary percutaneous coronary intervention (PCI). METHODS: The present case-control study was conducted on 185 STEMI patients who received SK (115 cases) or underwent primary PCI (70 cases). QTD and QT corrected dispersion before and 24 h after treatment. Likewise, they were also found to correct fatal arrhythmias (VT and VF) during the first 24 h after admission, and ejection fraction (EF) 24 h after treatment was evaluated. RESULTS: QTD decreased in the primary PCI group, though no significant difference was seen between the two studied groups (P > 0.05). A significant increase was detected in the EF mean values for the primary PCI-treated patients (P = 0.022). Moreover, there was a significant reduction in QTD of patients with fatal arrhythmias in the primary PCI group (P = 0.022). CONCLUSION: An overall QTD reduction in the primary PCI group and a significant decrease in QTD of patients with fatal arrhythmias in the primary PCI group show that this treatment strategy is more efficient than thrombolytic therapy. As an important indicator of proper myocardial function, EF can independently predict improved myocardial function in the primary PCI group.

Streptokinase Versus Unfractionated Heparin Nebulization in Patients With Severe Acute Respiratory Distress Syndrome (ARDS): A Randomized Controlled Trial With Observational Controls.

OBJECTIVE: To examine and compare nebulizing heparin versus streptokinase for reversing alveolar collapse nonresponsive to recruitment. DESIGN: A clinical trial at a tertiary intensive care unit (ICU). Sixty patients with severe acute respiratory distress syndrome (ARDS) (PaO2/FIO2 <100) nonresponsive to recruitment maneuver (RM), prone position, and neuromuscular block (NMB) were randomized into intervention arms or the standard-of-care arm. SETTING: The ICU at Beni-Suef University Hospital. PARTICIPANTS: Sixty patients with severe ARDS (PaO2/FIO2 <100) nonresponsive to RM, PP, and NMB. INTERVENTIONS: Nebulized heparin (10,000 IU/4 h), nebulized streptokinase (250,000 IU/4 h), and conservative management. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the change in PaO2/FIO2; the secondary outcomes included the change in compliance, plateau pressure, coagulation, and ICU mortality. The PaO2/FIO2 was significantly higher in the streptokinase group from day 1 to day 8 compared to the heparin and standard-of-care groups. Streptokinase produced PaO2/FIO2>100 at day 1, >200 at day 5, and >300 at day 7. The heparin group achieved a PaO2/FIO2 >100 at day 5 but remained <200 until day 8. The standard-of-care group did not achieve a PaO2/FIO2>100 after 8 days. Streptokinase significantly reduced plateau pressure and improved compliance at day 8. Only streptokinase decreased PaCO2 (p < 0.0001). Moreover, ICU mortality was significantly lower in streptokinase patients compared to other groups. Additionally, no heparin-induced thrombocytopenia was observed in all groups. CONCLUSION: Inhaled streptokinase serves as rescue therapy in patients with severe ARDS with improving oxygenation and lung mechanics more quickly than heparin or conventional management.

Immunoglobulin Attenuates Streptokinase-Mediated Virulence in Streptococcus dysgalactiae Subspecies equisimilis Necrotizing Fasciitis.

Background: Necrotizing fasciitis (NF) retains a very high mortality rate despite prompt and adequate antibiotic treatment and surgical debridement. Necrotizing fasciitis has recently been associated with Streptococcus dysgalactiae subspecies equisimilis (SDSE). Methods: We investigated the causes of a very severe clinical manifestation of SDSE-NF by assessing both host and pathogen factors. Results: We found a lack of streptokinase-function blocking antibodies in the patient resulting in increased streptokinase-mediated fibrinolysis and bacterial spread. At the same time, the clinical SDSE isolate produced very high levels of streptokinase. Exogenous immunoglobulin Gs (ex-IgGs) efficiently blocked streptokinase-mediated fibrinolysis in vitro, indicating a protective role against the action of streptokinase. In vivo, SDSE infection severity was also attenuated by ex-IgGs in a NF mouse model. Conclusions: These findings illustrate for the first time that the lack of specific antibodies against streptococcal virulence factors, such as streptokinase, may contribute to NF disease severity. This can be counteracted by ex-IgGs.

[Comparative efficacy of various thrombolytic agents in treatment of pulmonary embolism]. / Sravnitel'naia éffektivnost' razlichnykh tromboliticheskikh preparatov v lechenii tromboémbolii legochnoi arterii.

The authors carried out a retrospective analysis of clinical efficacy of streptokinase and alteplase (actilyse®) in patients presenting with high- and intermediate-to-high risk pulmonary artery thromboembolism (PATE) who were discharged from hospital after appropriate treatment performed. Of the total number of the treated patients, we formed 2 groups comprising 20 patients each, receiving alteplase (group 1) and streptokinase (group 2). The patients were comparable by the main clinical characteristics, predisposing factors, severity of pulmonary artery thromboembolism (PATE) and duration of treatment. Efficacy of thrombolytic therapy assessed clinically and instrumentally did not differ. However, by the stratified risk and frequency of PATE relapses, the condition of patients receiving alteplase turned out to be more severe. Based on the obtained results, a conclusion was made that actilyse is a drug of choice for treatment of patients with PATE.

Engineering of deglycosylated and plasmin resistant variants of recombinant streptokinase in Pichia pastoris.

Streptokinase, a therapeutically important thrombolytic agent, is prone to C-terminal degradation and plasmin-mediated proteolytic processing. Since the protein was glycosylated during secretion from Pichia pastoris, therefore, the role of carbohydrate moieties on its stability was analyzed via in vivo blocking of N-glycosylation using tunicamycin where an increased degradation of streptokinase was observed. Further, the in vitro site-directed mutagenesis of the three putative N-glycosylation sites at asparagine residues 14, 265, and 377 to alanine revealed the essentiality of glycosylation of the 14th amino acid residue in its post-translational proteolytic stability without significantly affecting its biological activity. However, the mutation of both Asn265 and Asn377 did not seem to contribute toward its glycosylation but resulted in a 39% lower specific activity in case of the rSK-N265,377A. Moreover, the mutation of all three glycosylation positions drastically reduced the secretory expression of native streptokinase from 347 to 186.6 mg/L for the triple mutant with a 14% lower specific activity of 56,738 IU/mg from 65,808 IU/mg. The secondary structure, tertiary structure, and thermal transition point (45-55 °C) of all the deglycosylated variants did not show any significant differences when compared with fully glycosylated native streptokinase using CD and fluorescence spectroscopy. Furthermore, the longer acting plasmin-resistant variants were also developed via the mutation of lysine residues 59 and 386 to glutamine which enhanced its biological stability as a ~ 1.5-fold increase in the caseinolytic zone size was observed in case of rSK-K59Q and also in rSK-K59,386Q mutant without affecting the structural properties.

Intrapleural streptokinase is effective and safe for children with multi-loculated empyema regardless of the time from disease onset.

AIM: This study compared the efficacy of administering intrapleural streptokinase to children with multi-loculated empyema within 14 days or at any time after disease onset. METHODS: We studied children under 12 years with multi-loculated empyema who were admitted to a teaching hospital in Chandigarh, India, from July 2013 to June 2017. They received antibiotics, pleural drainage and intrapleural streptokinase. The first group received three doses within 14 days of disease onset, the second received three doses regardless of time after onset and the third group received four to six doses regardless of time after onset. The three phases lasted 18, 18 and 12 months, respectively. RESULTS: Of 195 children, 133 (68%) received streptokinase within 14 days, 46 (24%) beyond 14 days and 16 (8%) did not receive it. There was no difference in surgical decortication (14/133 versus 7/46, p > 0.05) and median hospitalisation duration (15 versus 14 days, p > 0.05) between administration before versus after 14 days. Median hospitalisation was shorter with four to six doses than three doses (11 versus 16 days, p < 0.01). CONCLUSION: Intrapleural streptokinase was effective for multi-loculated empyema even when it was administered more than 14 days after disease onset and four to six doses were superior to three doses.

Observational study comparing pharmacoinvasive strategy with primary percutaneous coronary intervention in patients presenting with ST elevation myocardial infarction to a tertiary care centre in India.

Objective: The objective was to study whether the incidence of composite end points (mortality, cardiogenic shock and re-myocardial infarction [re-MI]) in pharmacoinvasive strategy was noninferior to primary percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI). Methods: This was an observational study which included 138 patients. The study included patients admitted with a diagnosis of STEMI within 24 h of symptom onset, who underwent primary PCI or pharmacoinvasive therapy in a single center over a 9-month period. Primary end points (death within 30 days, re-MI within 30 days, and cardiogenic shock) and secondary end points (arrhythmias, bleeding manifestations, ischemic stroke, ejection fraction, mechanical complications, and duration of hospital stay) were compared between the two groups at 1 month after intervention. Results: At one month follow-up, the incidence rate for primary end points was 5 events per 43 patients (11.6%) in pharmacoinvasive arm and 18 events per 95 patients (18.9%) in primary PCI arm, a difference of - 7.3% (95% confidence interval: 18.5, 7.1). This finding shows that pharmacoinvasive strategy as compared with primary PCI in the management of STEMI was equivalent in terms of composite primary outcome. There was no significant difference between the secondary outcomes between the two groups. Use of thrombus aspiration device and in turn the thrombus burden was significantly lower in the pharmacoinvasive arm. Conclusion: This observational study showed that pharmacoinvasive strategy was as good as primary PCI in STEMI, in our setting, where primary PCI may be delayed or not possible at all due to financial and logistic constraints.

Molecular Docking, Computational, and Antithrombotic Studies of Novel 1,3,4-Oxadiazole Derivatives.

A new series of 1,3,4-oxadiazoles derivatives was synthesized, characterized, and evaluated for their in vitro and in vivo anti-thrombotic activity. Compounds (3a⁻3i) exhibited significant clot lysis with respect to reference drug streptokinase (30,000 IU), and enhanced clotting time (CT) values (130⁻342 s) than heparin (110 s). High affinity towards 1NFY with greater docking score was observed for the compounds (3a, 3i, 3e, 3d, and 3h) than the control ligand RPR200095. In addition, impressive inhibitory potential against factor Xa (F-Xa) was observed with higher docking scores (5612⁻6270) with Atomic Contact Energy (ACE) values (-189.68 to -352.28 kcal/mol) than the control ligand RPR200095 (Docking score 5192; ACE -197.81 kcal/mol). In vitro, in vivo, and in silico results proposed that these newly synthesized compounds might be used as anticoagulant agents.