Recombinant Human Tissue Plasminogen Activator Research Articles

Neutrophil migration participates in the side effect of recombinant human tissue plasminogen activator.

Ischemic stroke remains a challenge in medical research because of the limited treatment options. Recombinant human tissue plasminogen activator (rtPA) is the primary treatment for recanalization. However, nearly 50% of the patients experience complications that result in ineffective reperfusion. The precise factors contributing to ineffective reperfusion remain unclear; however, recent studies have suggested that immune cells, notably neutrophils, may influence the outcome of rtPA thrombolysis via mechanisms such as the formation of neutrophil extracellular traps. This study aimed to explore the nonthrombolytic effects of rtPA on neutrophils and highlight their contribution to ineffective reperfusion. We evaluated the effects of rtPA treatment on middle cerebral artery occlusion in rats. We also assessed neutrophil infiltration and activation after rtPA treatment invitro and invivo in a small cohort of patients with massive cerebral ischemia (MCI). rtPA increased neutrophil infiltration into the brain microvessels and worsened blood-brain barrier damage during ischemia. It also increased the neutrophil counts of the patients with MCI. Neutrophils play a crucial role in promoting ischemic injury and blood-brain barrier disruption, making them potential therapeutic targets.

Morbimortality and determinants of reperfusion in ischemic stroke.

Cerebrovascular accident (or stroke) and ischemic heart disease are the the major causes of death in the world. It is estimated that about 85% of strokes are ischemic in origin. Reperfusion therapy in the acute phase of ischemic stroke with a recombinant human tissue plasminogen activator is effective, but some factors influence the success of this treatment. The aim of this study was to evaluate clinical aspects and possible determinants for reperfusion after venous thrombolysis. This is a retrospective, cross-sectional, observational study based on a review of hospital records of inpatients diagnosed with ischemic stroke treated with intravenous thrombolysis, the main outcome being reperfusion or not. Data from this study revealed a predominance of females in the group of reperfused patients and males in the non-reperfused group, both maintaining moderate severity on the National Institutes of Health Stroke Scale and admission without statistical significance (p>0.18). In addition, the mean admission severity score was 13.2 for the group of reperfused patients and 14.2 for those not reperfused, and the mean ejection fraction of both groups was within normal functionality, with a mean of 0.50 for reperfused patients and 0.62 for non-reperfused patients. We found an association between successful venous chemical thrombolysis reperfusion and lower mortality in patients with acute stroke.

Efficacy of Urinary Kallidinogenase Plus Intravenous Recombinant Tissue Plasminogen Activator for Stroke Patients With Extended Window: A Retrospective Analysis.

To assess the outcome of human urinary kallidinogenase (HUK) plus recombinant tissue plasminogen activator (rT-PA) intravenous thrombolysis for stroke patients with an extended time window(4.5 to 9 h). A total of 92 acute ischemic stroke patients who fulfilled the criteria were included in this study. All patients received basic treatment and intravenous rT-PA, and 49 patients received additional injections of HUK (HUK group) once a day for 14 consecutive days. Outcomes were indicated by the thrombolysis in cerebral infarction score as the primary endpoint and the National Institute of Health Stroke Scale, modified Rankin Scale, and Barthel Index as the secondary endpoints. The safety outcomes were the rate of symptomatic intracranial hemorrhage, bleeding, angioedema, and mortality. The National Institute of Health Stroke Scale scores were significantly lower in the HUK group at hospital discharge (4.55 ± 3.78 vs 7.88 ± 7.31, P = 0.009) and day 90 (4.04 ± 3.51 vs 8.12 ± 9.53, P = 0.011). The improvements in the Barthel Index scores were more obvious in the HUK group. Patients in the HUK group achieved favorable functional independence (67.35% vs 46.51%; odds ratio: 2.37; 95% CI: 1.01-5.53) at 90 days. The recanalization rate of the HUK group was 64.10%, whereas that was 41.48% in the control group (P = 0.050). The complete reperfusion rates were 42.9% and 23.3% in the HUK group and the control group, respectively. No significant differences were observed for adverse events between the two groups. Combination therapy of HUK plus rT-PA in patients with acute ischemic stroke with an extended time window can safely improve their functional outcomes.

Subretinal recombinant human tissue plasminogen activator injection using a 41G needle for the management of submacular hemorrhages: a 3-case report.

Subretinal recombinant human tissue plasminogen activator injection using a 41G needle for the management of submacular hemorrhages: a 3-case report.

Results of treatment of acute arterial thrombosis in patients with severe course of coronavirus infection COVID-19

Acute arterial thrombosis against the background of the novel coronavirus infection COVID-19 is an unfavorable complication. The survival prognosis in this category of patients is much worse than in the rest of the patient population. The aim of the work is to compare the immediate results of various methods of treating acute arterial insufficiency in patients with the novel coronavirus infection COVID-19, complicated by the development of acute arterial thrombosis of various localizations. 42 clinical cases of treatment of acute arterial pathology in patients with confirmed COVID-19 infection were analyzed. The severity of the underlying disease was not considered as a criterion for exclusion from the study. Surgical treatment by open intra-arterial thrombectomy under local anesthesia was used in 9 patients. Endovascular balloon angioplasty of arteries followed by selective catheter-guided thrombolysis with alteplase was performed in 17 patients. Sixteen patients received systemic transvenous thrombolysis with the recombinant human tissue plasminogen activator alteplase at a dose of 100 mg. The development of arterial thrombosis against the background of the coronavirus infection is accompanied by a high risk of death in the absence of timely and active specialized care. In the study group, 18 patients (43 %) with acute arterial thrombosis associated with COVID-19 deceased; of these, eight patients underwent open thrombectomy, eight patients had systemic transvenous thrombolysis with alteplase, and two patients underwent endovascular balloon angioplasty with selective catheter-guided thrombolysis with alteplase. A favorable outcome of the disease was noted in 24 patients (57 %); of these, fifteen patients underwent endovascular balloon angioplasty with selective catheter-guided thrombolysis with alteplase, and 8 patients had systemic thrombolysis with alteplase. Optimal treatment results were achieved in the group of patients using minimally invasive endovascular treatment methods in combination with tissue plasminogen activator. In the group of non-transportable patients with grade 3 respiratory failure and high perioperative risks, positive results were achieved exclusively through the use of systemic transvenous thrombolysis. These data allow us to consider justified the use of options for systemic thrombolysis and selective catheter thrombolysis in combination with endovascular reconstruction as an alternative to «open» surgical methods for thevtreatment of acute arterial insufficiency against the background of COVID-19.

Day 1 neutrophil-to-lymphocyte ratio (NLR) predicts stroke outcome after intravenous thrombolysis and mechanical thrombectomy

BackgroundThe neutrophil-to-lymphocyte ratio (NLR) is a biomarker reflecting the balance between inflammation (as indicated by the neutrophil count) and adaptive immunity (as indicated by the lymphocyte count). We aimed to estimate ability of NLR at admission and at day 1 for predicting stroke outcome after two reperfusion therapies: intravenous thrombolysis (IVT) and mechanical thrombectomy (MT).MethodsA retrospective analysis was performed on patients who received recombinant human tissue plasminogen activator (IVT) and/or underwent MT for acute ischemic stroke (AIS) at the First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China) from January 2018 to December 2020. Blood samples were taken on admission to hospital and on day 1 after stroke onset. Binary logistic regression models were applied to investigate potential associations between NLR at admission or day 1 and the following outcomes: symptomatic intracerebral hemorrhage (sICH), dependence, and mortality at 90 days. The ability of NLR to predict AIS outcome was analyzed using receiver operating characteristic (ROC) curves.ResultsData for 927 patients (576 IVT and 351 MT) were reviewed. High admission NLR was associated with dependence in IVT treatment [adjusted odds ratio (OR) 1.21, 95% confidence interval (CI) 1.14–1.23] and 90-day mortality in MT patients (OR 1.09, 95% CI 1.04–1.13). In IVT patients, high NLR at day 1 predicted dependence (OR 1.09, 95% CI 1.02–1.11), sICH (OR = 1.07, 95% CI 1.01–1.12), and 90-day mortality (OR 1.06, 95% CI 1.01–1.15). In MT patients, high NLR at day 1 also predicted dependence (OR 1.08, 95% CI 1.02–1.11) and sICH (OR 1.03, 95% CI 1.01–1.09). ROC analysis confirmed that NLR at day 1 could predict dependence (cut-off 4.2; sensitivity 68.7%; specificity 79.6%), sICH (cut-off 5.1; sensitivity 57.9%, specificity 73.5%), and death (cut-off 5.4; sensitivity 78.8%; specificity 76.4%) in IVT patients. Z values of area under the curves were compared between admissioin and day 1 NLR in IVT patients and showed day 1 NLR can better predict dependence (Z = 2.8, p = 0.004) and 90-day death (Z = 2.8, p = 0.005).ConclusionsNLR is a readily available biomarker that can predict AIS outcome after reperfusion treatment and day 1 NLR is even better than admission NLR.

Acupuncture intervention prolongates thrombolysis time window by regulating cerebral cortex angiogenesis-related genes and proteins in cerebral infarction rats

To observe the effect of acupuncture on the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and endostatin (Endostatin, ES) mRNAs and proteins (angiogenesis related factors) in the ischemic penumbra region in rats with cerebral infarction (CI), so as to explore its underlying mechanisms in prolonging the time window of thrombolysis therapy for CI. A total of 48 male SD rats were randomly divided into sham operation, model, medication (6 h thrombolysis) and acupuncture (Acupunct)+medication groups (n=12 in each group). The CI model was established using modified auto-thrombus method. Six hours after thrombolysis, recombinant human tissue plasminogen activator (rt-PA,10 mg/kg) was given to rats of the thrombolysis group through tail vein. Acupuncture was applied at "Shuigou"(CV26) and bilateral "Neiguan" (PC6) 2 h after successful modeling, and the needles were retained for 30 minutes. Cerebral blood flow (CBF) was monitored during modeling in each group, and the neurological deficit score (0-7 points) was given 2 h and 24 h after successful modeling according to Bederson's methods. The cerebral infarction volume was observed after triphenyltetrazole chloride (TTC) staining. The protein and mRNA expression levels of VEGF, bFGF and ES in the ischemic penumbra region of the right cerebral cortex were detected by Western blot and real-time PCR, separately. The neurological deficit score at both 2 h and 24 h after modeling, percentage of cerebral infarction volume, and the expression levels of VEGF, bFGF and ES proteins and mRNAs in the model group were significantly higher than those of the sham operation group (P<0.01, P < 0.05). Compared with the model group, the neurological deficit score 24 h (not at 2 h) after modeling and percentage of cerebral infarction volume, and the expression levels of ES protein and mRNA in the Acupunct+medication group (not in the medication group) were notably lower (P<0.05, P<0.01), while the expression levels of VEGF and bFGF proteins and mRNAs in the Acupunct +medication group (not in the medication group) were considerably higher (P<0.01, P<0.05). No significant differences were found between medication and model groups in the CI percentage, VEGF, bFGF and ES proteins and mRNAs (P>0.05). The therapeutic effect of Acupunct +medication group was significantly superior to that of medication in lowering neurological deficit score, percentage of CI volume and expression of ES protein and mRNA and in up-regulating the expression of VEGF and bFGF proteins and mRNAs (P<0.05, P<0.01). Acupuncture and timely intervention can prolong the time window of thrombolysis in CI rats, which may be related to its function in up-regulating the expression of VEGF and bFGF mRNAs and proteins and in down-regulating the expression of ES mRNA and protein in ischemic cerebral cortex.

Influences of blood lipids on the occurrence and prognosis of hemorrhagic transformation after acute cerebral infarction: a case-control study of 732 patients

BackgroundTo study the influence of blood lipid levels on hemorrhagic transformation (HT) and prognosis after acute cerebral infarction (ACI).MethodsPatients with ACI within 72 h of symptoms onset between January 1st, 2015, and December 31st, 2016, were retrospectively analyzed. Patients were divided into group A (without HT) and group B (HT). The outcomes were assessed after 3 months of disease onset using the modified Rankin Scale (mRS). An mRS score of 0–2 points indicated excellent prognosis, and an mRS score of 3–6 points indicated poor prognosis.ResultsA total of 732 patients conformed to the inclusion criteria, including 628 in group A and 104 in group B. The incidence of HT was 14.2%, and the median onset time was 2 d (interquartile range, 1–7 d). The percentages of patients with large infarct size and cortex involvement in group B were 80.8 and 79.8%, respectively, which were both significantly higher than those in group A (28.7 and 33.4%, respectively). The incidence rate of atrial fibrillation (AF) in group B was significantly higher than that in group A (39.4% vs. 13.9%, P < 0.001). The adjusted multivariate analysis results showed that large infarct size, cortex involvement and AF were independent risk factors of HT, while total cholesterol (TC) was a protective factor of HT (OR = 0.359, 95% CI 0.136–0.944, P = 0.038). With every 1 mmol/L reduction in normal TC levels, the risk of HT increased by 64.1%. The mortality and morbidity at 3 months in group B (21.2 and 76.7%, respectively) were both significantly higher than those in group A (8.0 and 42.8%, respectively). The adjusted multivariate analysis results showed that large infarct size (OR = 12.178, 95% CI 5.390–27.516, P < 0.001) was an independent risk factor of long-term unfavorable outcomes, whereas low-density lipoprotein cholesterol (LDL-C) was a protective factor (OR = 0.538, 95% CI 0.300–0.964, P = 0.037). With every 1 mmol/L reduction in normal LDL-C levels, the risk of an unfavorable outcome increased by 46.2%. Major therapies, including intravenous recombinant human tissue plasminogen activator (rTPA), intensive lipid-lowering statins and anti-platelets, were not significantly related to either HT or long-term, post-ACI poor prognosis.ConclusionFor patients with large infarct sizes, especially those with cortex involvement, AF, or lower levels of TC, the risk of HT might increase after ACI. The risk of a long-term unfavorable outcome in these patients might increase with a reduction in LDL-C.

Fibrinolysis of Contracted Blood Clots Depends on Whether Plasminogen Activator Acts from inside or Outside

Fibrinolysis involves the dissolution of polymeric fibrin networks that is required to restore blood flow through vessels obstructed by clots and thrombi. The efficiency of lysis depends on the susceptibility of fibrin to enzymatic digestion, which is governed by the structure and spatial organization of fibrin fibers as well as porosity and composition of the clot. Platelet-driven clot contraction results in compaction of the erythrocytes into the core of the clot, effectively reducing the permeability of the clot, and influences fibrin network structure. We have shown that clot contraction is reduced in blood from patients with thrombotic conditions such ischemic stroke and deep vein thrombosis, which points to the clinical importance of understanding the influence of clot contraction on efficacy of fibrinolysis. Here, we examined the effects of clot contraction on the rate of internal fibrinolysis emanating from within the clot to simulate (patho)physiological conditions, and external fibrinolysis initiated from the clot exterior to simulate therapeutic thrombolysis.Fibrinolysis was induced and the kinetics of lysis was measured in parallel in contracted versus uncontracted clots from the same citrated human blood samples. Clot formation and platelet activation were initiated with 1 U/ml thrombin and 2 mM CaCl2. Clot contraction was either unaffected or impaired by inhibiting platelet non-muscle myosin IIa (blebbistatin), actin polymerization (latrunculin A), and platelet-fibin(ogen) binding (abciximab). To examine internal fibrinolysis, 75 ng/ml of human recombinant tissue plasminogen activator (tPA) was added prior to initiation of clotting, allowing for tPA to be uniformly distributed through the clot volume and for fibrinolysis occur after the clot has formed. We used optical tracking to follow clot size in a time dependent manner. Contracted clots were completely lysed at a rate that was at least 2 times faster than clots with impaired contraction. Specifically, the average time to complete lysis was 33±4 minutes for contracted clots versus 59±3, 84±4, 75±3 minutes when contraction was impaired by blebbistatin, latrunculin A, and abciximab, respectively (p<0.001). To examine external fibrinolysis, blood spiked with purified human 125I-fibrinogen was allowed to clot and contract (unless contraction was inhibited) prior to the addition of 75 ng/ml tPA. Clots with impaired contraction released 2-4-fold more radiolabeled soluble degradation products during the first 30 minutes and continued to lyse at a rate 4-fold faster than contracted clots over the initial 4 hours following addition of tPA. This reduction of the fibrinolysis rate in contracted clots was not due to the expulsion of serum-soluble anti-fibrinolytic compounds during the contraction process because serum replacement with a buffer did not affect the lysis rate.This difference in the susceptibility of contracted and uncontracted clots to internal versus external lysis suggests that the lysis rate is dominated by the interplay of clot permeability to fibrinolytic enzymes and the spatial proximity of the fibrin fibers themselves. Despite limitations of in vitro experimental models, numerous studies on fibrinolysis have demonstrated the relevance of experimental findings to pathophysiological fibrinolysis and therapeutic thrombolysis. Enhancement of fibrinolysis in contracted blood clots is consistent with the need to dissolve mature clots once they have performed their hemostatic function in a vessel on in a wound. The reduced rates of dissolution of contracted clots in our model of externally applied tPA could account for the inefficacy of therapeutic thrombolysis of old thrombi that likely underwent more compaction compared to newer thrombi. Our studies point to the clinical importance of understanding how mechanical remodeling of clots and thrombi may influence their fibrinolytic resolution and could inform the development of improved thrombolytic therapies. This work, in part, was supported by the Program for Competitive Growth at KFU. DisclosuresNo relevant conflicts of interest to declare.

High glucose and low specific cell growth but not mild hypothermia improve specific r-protein productivity in chemostat culture of CHO cells.

In the biopharmaceutical sector, Chinese hamster ovary (CHO) cells have become the host of choice to produce recombinant proteins (r-proteins) due to their capacity for correct protein folding, assembly, and posttranslational modification. However, the production of therapeutic r-proteins in CHO cells is expensive and presents insufficient production yields for certain proteins. Effective culture strategies to increase productivity (qp) include a high glucose concentration in the medium and mild hypothermia (28–34 °C), but these changes lead to a reduced specific growth rate. To study the individual and combined impacts of glucose concentration, specific growth rate and mild hypothermia on culture performance and cell metabolism, we analyzed chemostat cultures of recombinant human tissue plasminogen activator (rh-tPA)-producing CHO cell lines fed with three glucose concentrations in feeding media (20, 30 and 40 mM), at two dilution rates (0.01 and 0.018 1/h) and two temperatures (33 and 37 °C). The results indicated significant changes in cell growth, cell cycle distribution, metabolism, and rh-tPA productivity in response to the varying environmental culture conditions. High glucose feed led to constrained cell growth, increased specific rh-tPA productivity and a higher number of cells in the G2/M phase. Low specific growth rate and temperature (33 °C) reduced glucose consumption and lactate production rates. Our findings indicated that a reduced specific growth rate coupled with high feed glucose significantly improves r-protein productivity in CHO cells. We also observed that low temperature significantly reduced qp, but not cell growth when dilution rate was manipulated, regardless of the glucose concentration or dilution rate. In contrast, we determined that feed glucose concentration and consumption rate were the dominant aspects of the growth and productivity in CHO cells by using multivariate analysis.

Early Abrogation of Gelatinase Activity Extends the Time Window for tPA Thrombolysis after Embolic Focal Cerebral Ischemia in Mice.

Acute ischemic stroke (AIS) is caused by clotting in the cerebral arteries, leading to brain oxygen deprivation and cerebral infarction. Recombinant human tissue plasminogen activator (tPA) is currently the only Food and Drug Administration-approved drug for ischemic stroke. However, tPA has to be administered within 4.5 h from the disease onset and delayed treatment of tPA can increase the risk of neurovascular impairment, including neuronal cell death, blood-brain barrier (BBB) disruption, and hemorrhagic transformation. A key contributing factor for tPA-induced neurovascular impairment is activation of matrix metalloproteinase-9 (MMP-9). We used a clinically-relevant mouse embolic model of focal-cerebral ischemia by insertion of a single embolus of blood clot to block the right middle cerebral artery. We showed that administration of the potent and highly selective gelatinase inhibitor SB-3CT extends the time window for administration of tPA, attenuating infarct volume, mitigating BBB disruption, and antagonizing the increase in cerebral hemorrhage induced by tPA treatment. We demonstrated that SB-3CT attenuates tPA-induced expression of vascular MMP-9, prevents gelatinase-mediated cleavage of extracellular laminin, rescues endothelial cells, and reduces caveolae-mediated transcytosis of endothelial cells. These results suggest that abrogation of MMP-9 activity mitigates the detrimental effects of tPA treatment, thus the combination treatment holds great promise for extending the therapeutic window for tPA thrombolysis, which opens the opportunity for clinical recourse to a greater number of patients.

Effect of recombinant human prourokinase on thrombolysis in a rabbit model of thromboembolic stroke.

The aim of the present study was to investigate the efficacy of recombinant human prourokinase (rhPro-UK) on thromboembolic stroke in rabbits. A total of 210 rabbits were used in experiments. The 180 thromboembolic stroke rabbits were divided into three therapeutic time windows with six groups in each time window (n=10). The model group was administered saline, the reagent groups were administered rhPro-UK (2.5×, 5× and 10×104 U/kg), and the positive control groups were administered 5×104 urokinase (UK) U/kg and 4.5 mg/kg recombinant human tissue plasminogen activator via intravenous infusion at 3, 4.5 and 6 h after embolism. The remaining 30 rats (that had not undergone occlusion by autologous blood clots) served as a sham group and were administered saline. The radioactive intensity was detected using a medical gamma counter before and after the administration of the drug for 15, 30, 45, 60, 75, 90, 105 and 120 min. At 24 h after treatment, the brain samples were coronally sliced into 5 mm sections and hemorrhage was estimated used a semiquantitative method by counting the number of section faces with hemorrhaging. The plasma was collected for prothrombin time, activated partial thromboplastin time, fibrinogen and thrombin time tests using a solidification method with a blood coagulation factor analyzer. In addition, α2-antiplasmin (α2-AP) was evaluated using ELISA methods using a RT-6100 microplate reader. At the 3 h time point, the thrombolysis rate of rhPro-UK(2.5×, 5× and 10×104 U/kg) was 21.5% (P<0.05), 36.8% (P<0.001) and 55.0% (P<0.001), respectively together with patency rates of 10% (P>0.05), 40% (P<0.05) and 70% (P<0.001). Furthermore, α2-AP levels were reduced by 5.3% (P>0.05), 5.3% (P>0.05) and 18.1% (P<0.05). At the 4.5 h time point, the thrombolysis rate was 18.8% (P<0.05), 29.9% (P<0.01) and 49.0% (P<0.001) together with patency rates of 10% (P>0.05), 30% (P<0.05) and 50% (P<0.01), and α2-AP levels were reduced by 2.4% (P>0.05), 6.5% (P>0.05) and 17.8% (P<0.05). At the 6 h time point, the thrombolysis rate was 14.7% (P<0.05), 24.1%(P<0.01) and 35.7% (P<0.001) together with patency rates of 20% (P>0.05), 30% (P<0.05) and 40% (P<0.01), and α2-AP levels were reduced by 5.7% (P>0.05), 12.7% (P>0.05) and 22.2% (P<0.01). No significant differences (P>0.05) were identified between rhPro-UK (2.5×, 5× and 10×104 U/kg) and the model group regarding hemorrhage type, size and blood coagulation factors at the different time points. Thus, rhPro-UK promoted thrombolysis and recanalization (patency rate), with reduced risk of cerebral hemorrhage, and thus exerted protective effects on cerebral ischemia rabbits.

Variations of Postresuscitation Lung Function after Thrombolysis Therapy in a Cardiac Arrest Porcine Model Caused by Pulmonary Thromboembolism.

Background:Study of lung function in survivor from cardiac arrest (CA) caused by pulmonary thromboembolism (PTE) was rare. The aim of this study was to investigate the variations of postresuscitation lung function after thrombolysis treatment in a CA porcine model caused by PTE.Methods:After 2 min of untreated CA, pigs of 10–12 weeks with a weight of 30 ± 2 kg (n = 24) were treated with recombinant human tissue plasminogen activator (50 mg). Cardiopulmonary resuscitation (CPR) and ventilation were initiated after drug administration. Pulmonary function and arterial blood gas parameters were measured at baseline, return of spontaneous circulation (ROSC) immediately, and 1 h, 2 h, 4 h, and 6 h after ROSC.Results:The dynamic lung compliance decreased significantly at ROSC immediately and 1 h after ROSC compared to baseline (21.86 ± 2.00 vs. 26.72 ± 2.20 ml/mmHg and 20.38 ± 1.31 vs. 26.72 ± 2.20 ml/mmHg, respectively; P < 0.05; 1 mmHg = 0.133 kPa). Compared with baseline, airway resistance increased significantly at ROSC immediately and 1 h after ROSC (P < 0.05). Respiratory index also increased after ROSC and showed significant differences among baseline, ROSC immediately, and 2 h after ROSC (P < 0.05). Oxygen delivery decreased at ROSC immediately compared to baseline (P < 0.05). The oxygenation index decreased significantly at any time after ROSC compared to baseline (P < 0.05). Extravascular lung water index and pulmonary vascular permeability index (PVPI) showed significant differences at ROSC immediately compared to baseline and 1 h after ROSC (P < 0.05); PVPI at ROSC immediately was also different from 6 h after ROSC (P < 0.05). Ventilation/perfusion ratios increased after ROSC (P < 0.05). Histopathology showed fibrin effusion, bleeding in alveoli, and hemagglutination in pulmonary artery.Conclusions:Lung function remains abnormal even after CPR with thrombolysis therapy; it is essential to continue anticoagulation and symptomatic treatment after ROSC.

Clinical efficacy of sequential therapy for butylphthalide combined with alteplase in the treatment of acute cerebral infarction

Objective To observe the effect of butylphthalide sequential therapy combined with injection of alteplase(injection with recombinant human collagenous tissue plasminogen activator) in the treatment of acute cerebral infarction (ACI). Methods 61 patients with ACI and within 4.5 hours of onset were selected, and they were divided into treatment group(butylphthalide combined with alteplase group, 31 cases) and the control group (alteplase only group, 30 cases) by random number table.The two groups were given glucose-lowering, statins for maintaining the blood pressure, as well as aspirin enteric tablets or clopidogrel for those without bleeding on the 24 hour review head CT in the acute phase.The treatment group was given alteplase for injection with sequential butylphthalide therapy (butylphthalide injection for 2 weeks followed by an oral administration of butylphthalide soft capsules for 3 months), and the control group was given only alteplase for injection.The National Institute of Health stroke scale (NIHSS) and Barthel index (BI) were used for evaluating the final clinical efficacy. Results The NIHSS scores of the treatment group compared with the control group at 24 hour, 14 days and 3.5 months after the treatment had statistically significant differences(t=-0.102, -1.964, -2.444, P=0.037, 0.018 and 0.012). The NIHSS scores of the treatment group had decreased 2%, 27% and 41% compared with the control group at 24 hour, 14 days and 3.5 months after the treatment, respectively.The BI score of the treatment group and control group at 3.5 months after treatment had statistically significant difference(t=-1.956, P=0.029). Conclusion The sequential butylphthalide therapy combined with injection of alteplase has good synergistic effect for the patients with onset of ACI less than 4.5 hours, and it is a safe and effective treatment method for ACI within 4.5 h and it is worthy of clinical promotion. Key words: Cerebral infarction, acute; Butylphthalide; Alteplase

Impact of sodium butyrate and mild hypothermia on metabolic and physiological behaviour of CHO TF 70R cells

Background: To reduce costs associated with productivity of recombinant proteins in the biopharmaceutical industry, research has been focused on regulatory principals of growth and survival during the production phases of the cell culture. The main strategies involve the regulation of cell proliferation by the modulation of cell cycle control points (G1/S or G2/M) with mild hypothermia and the addition of sodium butyrate (NaBu). In this study, batch culture strategies were evaluated using CHO TF 70R cells producing the recombinant human tissue plasminogen activator (rh-tPA), to observe their individual and combined effect on the cellular physiological state and relevant kinetic parameters. Results: NaBu addition has a negative effect on the mitochondrial membrane potential (∆Ψm), the values of which are remarkably diminished in cultures exposed to this cytotoxic compound. This effect was not reflected in a loss of cell viability. NaBu and mild hypothermic conditions increased the doubling time in the cell cultures, suggesting that these strategies triggered a general slowing of each cell cycle phase in a different way. Finally, the individual and combined effect of NaBu and mild hypothermia produced an increase in the specific rh-tPA productivity in comparison to the control at 37oC without NaBu. Nevertheless, both strategies did not have a synergistic effect on the specific productivity. Conclusions: The combination of NaBu addition and mild hypothermic condition causes an impact on physiological and metabolic state of CHO TF 70R cells, decreasing cell growth rate and improving glucose consumption efficiency. These results therefore provide a promising strategy to increases specific productivity of rh-tPA. Normal 0 false false false ES-CL X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabla normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; mso-bidi-font-size:10.0pt; font-family:Arial,sans-serif; color:black; mso-ansi-language:ES-CL; mso-fareast-language:ES-CL;}

Abstract WP105: Tissue Plasminogen Activator (tPA) is Essential for Functional Recovery After Stroke by Promoting Axonal Outgrowth

Objectives: Stroke is the leading cause of long term neurological disability with limited therapeutic options. Human recombinant tissue plasminogen activator (tPA) is currently the only FDA approved drug for the thrombolytic treatment of ischemic stroke. Emerging evidence suggests that the effects of tPA in ischemic brain may extend beyond its thrombolytic activity. In this study, we investigated the role of tPA in long term stroke recovery. Methods: Cortical infarct was induced by distal middle cerebral artery occlusion (dMCAO) in tPA knockout (KO) and wild type (WT) mice. Sensorimotor functions were evaluated at 3-35 days after dMCAO. White matter integrity was assessed by luxol fast blue staining, immunohistochemistry for SMI-32, and diffusion tensor imaging (DTI). The neuronal tracer biotinylated dextran amine (BDA) was used to label the corticorubral tract and the corticospinal tract. For rescue experiment, tPA (2mg/kg) was delivered intranasally to tPA KO mice once a day for 14 days starting 6h after dMCAO. Results: Infarct volume was comparable between tPA KO and WT mice after dMCAO. Sensorimotor deficits after dMCAO were exacerbated in tPA KO mice than WT mice. tPA KO mice also showed more severe demyelination in post-stroke white matter and reduced axonal sprouting at 35 days after dMCAO compared to WT mice. DTI studies revealed deteriorated white matter integrity in tPA KO mice, as manifested by decreased fractional anisotropy. Intranasal delivery of tPA after dMCAO rescued the neurological phenotype shown by tPA KO mice. Conclusion: Endogenous tPA promotes white matter integrity and is essential for functional recovery after ischemic stroke. tPA may be a novel neurorestorative therapy for stroke recovery.

Efficacy and safety of combined intraventricular fibrinolysis with lumbar drainage for prevention of permanent shunt dependency after intracerebral hemorrhage with severe ventricular involvement: A randomized trial and individual patient data meta-analysis.

Intraventricular hemorrhage (IVH) is a negative prognostic factor in intracerebral hemorrhage (ICH) and is associated with permanent shunt dependency in a substantial proportion of patients post-ICH. IVH treatment by intraventricular fibrinolysis (IVF) was recently linked to reduced mortality rates in the CLEAR III study and IVF represents a safe and effective strategy to hasten clot resolution that may reduce shunt rates. Additionally, promising results from observational studies reported reductions in shunt dependency for a combined treatment approach of IVF plus lumbar drains (LDs). The present randomized, controlled trial investigated efficacy and safety of a combined strategy-IVF plus LD versus IVF alone-on shunt dependency in patients with ICH and severe IVH. This randomized, open-label, parallel-group study included patients aged 18 to 85 years, prehospital modified Rankin Scale ≤3, ICH volume < 60ml, Glasgow Coma Scale of <9, and severe IVH with tamponade of the third and fourth ventricles requiring placement of external ventricular drainage (EVD). Over a 3-year recruitment period, patients were allocated to either standard treatment (control group receiving IVF consisting of 1mg of recombinant human tissue plasminogen activator every 8 hours until clot clearance of third and fourth ventricles) or a combined treatment approach of IVF and-upon clot clearance of third and fourth ventricles-subsequent placement of an LD for drainage of cerebrospinal fluid (CSF; intervention group). The primary endpoint consisted of permanent shunt placement indicated after a total of three unsuccessful EVD clamping attempts or need for CSF drainage longer than 14 days in both groups. Secondary endpoints included IVF- and LD-related safety, such as bleeding or infections, and functional outcome at 90 and 180 days. Conducted endpoint analyses used individual patient data meta-analyses. The study was registered at clinicaltrials.gov (NCT01041950). The trial was stopped upon predefined interim analysis after 30 patients because of significant efficacy of tested intervention. The primary endpoint was analyzed without dropouts and was reached in 43% (7 of 16) of the control group versus 0% (0 of 14) of the intervention group (p = 0.007). Meta-analyses were based on overall 97 patients, 45 patients receiving IVF plus LD versus 42 with IVF only. Meta-analyses on shunt dependency showed an absolute risk reduction of 24% for the intervention (LD, 2.2% [1 of 45] vs no-LD, 26.2% [11 of 42]; odds ratio [OR] = 0.062; confidence interval [CI], 0.011-0.361; p = 0.002). Secondary endpoints did not show significant differences for CSF infections (OR = 0.869;CI, 0.445-1.695; p = 0.680) and functional outcome at 90 days (OR = 0.478; CI, 0.190-1.201; p = 0.116), yet bleeding complications were significantly reduced in favor of the intervention (OR = 0.401; CI, 0.302-0.532; p < 0.001). The present trial and individual patient data meta-analyses provide evidence that, in patients with severe IVH, as compared to IVF alone, a combined approach of IVF plus LD treatment is feasible and safe and significantly reduces rates of permanent shunt dependency for aresorptive hydrocephalus post-ICH. ANN NEUROL 2017;81:93-103.

Effect of Temperature Downshift on the Transcriptomic Responses of Chinese Hamster Ovary Cells Using Recombinant Human Tissue Plasminogen Activator Production Culture.

Recombinant proteins are widely used as biopharmaceuticals, but their production by mammalian cell culture is expensive. Hence, improvement of bioprocess productivity is greatly needed. A temperature downshift (TDS) from 37°C to 28–34°C is an effective strategy to expand the productive life period of cells and increase their productivity (qp). Here, TDS in Chinese hamster ovary (CHO) cell cultures, initially grown at 37°C and switched to 30°C during the exponential growth phase, resulted in a 1.6-fold increase in the qp of recombinant human tissue plasminogen activator (rh-tPA). The transcriptomic response using next-generation sequencing (NGS) was assessed to characterize the cellular behavior associated with TDS. A total of 416 (q > 0.8) and 3,472 (q > 0.9) differentially expressed transcripts, with more than a 1.6-fold change at 24 and 48 h post TDS, respectively, were observed in cultures with TDS compared to those at constant 37°C. In agreement with the extended cell survival resulting from TDS, transcripts related to cell growth arrest that controlled cell proliferation without the activation of the DNA damage response, were differentially expressed. Most upregulated genes were related to energy metabolism in mitochondria, mitochondrial biogenesis, central metabolism, and avoidance of apoptotic cell death. The gene coding for rh-tPA was not differentially expressed, but fluctuations were detected in the transcripts encoding proteins involved in the secretory machinery, particularly in glycosylation. Through NGS the dynamic processes caused by TDS were assessed in this biological system.

Adverse effects of intrapleural instillation of tissue plasminogen activator in a horse: Suspected re‐expansion pulmonary oedema

SummaryThis case report describes a 5‐year‐old pregnant Warmblood mare that was being treated for fibrinous bacterial pleuropneumonia. Since initial attempts to drain and lavage both pleural cavities were ineffective due to the presence of extensive intrapleural fibrin loculations, recombinant human tissue plasminogen activator (tPA) was instilled into both pleural cavities, to promote fibrinolysis and improve drainage. Within 1–2 h of instilling tPA, the horse became distressed, with increasing dyspnoea, tachycardia, pleurodynia and hypoxaemia. At 4 h post tPA instillation, diffuse bilateral pulmonary oedema was evidenced by the onset of widespread audible inspiratory crackles and ultrasonographic ring‐down artefacts. Ultrasonography demonstrated that tPA had induced pleural fibrinolysis, thereby removing the restrictive effects of pleural adhesions on lung motion and facilitating lung re‐expansion. Re‐expansion pulmonary oedema was suspected, although an adverse drug reaction could not be excluded. The complication resolved with nasal oxygen supplementation, and administration of frusemide, meloxicam, morphine and hydroxyethyl starch. Subsequent repetition of intrapleural tPA instillation and thoracic drainage had no apparent adverse effect. The mare was discharged from the hospital and subsequently foaled successfully. The pathogenesis, diagnosis and management of re‐expansion pulmonary oedema are reviewed.

Development of a Method for Industrial Cultivation of a Producer of Human Recombinant Tissue Plasminogen Activator

An industrial perfusion method for culturing of the CHO 1F8 cell line, a producer of human recombinant tissue plasminogen activator, has been developed. It permits to obtain a product that meets the requirements of the European Pharmacopoeia in respect of specific activity, content of the single-strand form and glycosylation profile. The suggested method makes it possible to obtain 38+3 g rTPA, or 750 doses of drug per cycle in a 100-L bioreactor.