Combinatorial gene therapy induces regression of hepatic encephalopathy.

Capillarization of the sinusoid impedes the clearance of neurotoxic substances in liver fibrosis. These events may result in hepatic encephalopathy. Neurological and hepatic features of rats after bile duct ligation (BDL) supplemented with Manganese (BDL+Mn(2+)) were examined. The 4-week-old BDL rats had elevated levels of ammonia and were concomitantly fed with 1 mg ml(-1) of MnCl(2) in drinking water (BDL/Mn(+2)). Five out of fifteen rats were killed and the serum, liver and brain tissue (striatum and substantia nigra) were recovered. Of the remaining BDL/Mn(+2)-cirrhotic animals (n=10), five were injected with a combination of Adenovirus-human plasminogen activator (Ad-huPA) and Adenovirus-matrix metalloproteinase-8 (Ad-MMP-8) (3 × 10(11)+1.5 × 10(11) vector particles per kg), and five with 4.5 × 10(11) vector particles per kg of Adenovirus-ß-galactosidase (Ad-ß-Gal). This treatment was carried on for 10 days. The BDL/Mn(+2) rats displayed tremor, rigidity and gait abnormalities, which improved notably with combinatorial gene therapy, as well as motor coordination. Liver fibrosis was evidently less after treatment with Ad-huPA+Ad-MMP-8 (25%). In the brain (striatum), Ad-huPA+Ad-MMP-8 treatment rendered higher concentrations of dopamine compared with Ad-ß-Gal-treated encephalopathic rats (210 and 162 ng g(-1) of tissue, respectively). The BDL/Mn(+2) animals and controls treated with Ad-ß-Gal showed abnormal morphology in astrocytes (gliosis) in striatum and substantia nigra, in which expressions of green fibrillar acidic protein and tyrosine hydroxylase were altered. These abnormalities decreased with Ad-huPA+Ad-MMP-8 treatment. Importantly, the latter animals showed an increment in sprouting of nervous fibers in substantia nigra. Combinatorial gene therapy improves neuroanatomical and neurochemical characteristics similar to human hepatic encephalopathy.

Fibrinolytic treatment for acute ischaemic stroke.

Ischaemic stroke is a leading cause of death and disability in the US. At present, intravenous administration of tissue plasminogen activator within 3 h of symptom onset is the only proven effective treatment for patients with acute ischaemic stroke. Unfortunately, most treated patients do not make a functional recovery and very few patients presenting with acute stroke qualify for intravenous tissue plasminogen activator therapy. The focus of current research is to extend the therapeutic window for intervention beyond 3 h, and to improve the outcome of treated patients. The purpose of the present paper is to describe the current state of affairs for intravenous plasminogen activators, and to review recently published research. Agents and strategies under investigation include the intra-arterial delivery of plasminogen activators or antiplatelet agents, as well as combined intravenous/intra-arterial protocols.

Tratamiento intravenoso con activador del plasminógeno tisular en la isquemia cerebral aguda / Intravenous tissue-type plasminogen activator for the treatment of acute cerebral ischemia

FUNDAMENTO Y OBJETIVO: Se desconoce si el riesgo de transformación hemorrágica sintomática (THS) del infarto cerebral por el uso de activador del plasminógeno tisular (t-PA) en la práctica clínica es superior al observado en los ensayos clínicos. El objetivo de este estudio fue analizar la seguridad y la evolución clínica de los pacientes con isquemia cerebral aguda que recibieron tratamiento abierto con t-PA en hospitales españoles. PACIENTES Y MÉTODO: Estudio observacional y prospectivo que incluyó a 155 pacientes consecutivos con isquemia cerebral de menos de 3 h de evolución, o de menos de 6 h en ausencia de signos tempranos de infarto cerebral extenso en la tomografía computarizada (TC) craneal. Se administraron 0,9 mg/kg de t-PA intravenoso, el 10 per cent en bolo y el resto en infusión continua durante 60 min. El deterioro neurológico se cuantificó con la escala del ictus del NIH (NIHSS). Se evaluaron la THS en la TC realizada a las 24-36 h, la mortalidad y la capacidad funcional a los 3 meses. Los pacientes fueron atendidos por neurólogos expertos, y controlados en unidades de ictus. RESULTADOS: La mediana de la NIHSS al ingreso fue de 16, y el tiempo medio desde el inicio de los síntomas hasta el tratamiento, de 163 min. Se observó THS en 12 pacientes (7,7 per cent; intervalo de confianza [IC] del 95 per cent, 4,0-13,1), que fue fatal en 7 (4,5 per cent; IC del 95 per cent, 1,8-9,1). La mortalidad global a los 90 días fue del 16,8 per cent (IC del 95 per cent, 11,2-23,6). A las 24 h, el 48 per cent (IC del 95 per cent, 39,7-55,9) de los pacientes había mejorado en 4 puntos o más en la NIHSS, y el 29 per cent (IC del 95 per cent, 22,0-36,8) había mejorado en 10 puntos o más o se había recuperado. En el día 90, el 56 per cent (IC del 95 per cent, 47,9-64,1) de los pacientes era independiente. CONCLUSIONES: Este estudio demuestra que en la práctica clínica la administración intravenosa de tPA por neurólogos con experiencia, en centros españoles con unidades o equipos de ictus, es segura y se asocia a una evolución clínica favorable, comparable a la observada en los ensayos clínicos (AU)

Modulation of PAI-1 and tPA activity and thrombolytic effects of corilagin.

In this study, Charlton's and Tomihisa's methods were modified to investigate the thrombolytic effect of corilagin from the Chinese herbal plant Phyllanthus urinaria L., as well as its effect on carotid artery patency status. The activity of type 1 plasminogen activator inhibitor (PAI-1) in rat plasma or platelet-released substances and tissue-type plasminogen activator (tPA) in rat plasma was assayed by use of a chromogenic substrate. The results showed that corilagin had a dose-dependent thrombolytic effect in rats. 5 mg/kg of corilagin produced a nearly similar reperfusion rate to that of 20000 U/kg of urokinase, whereas it produced a lower reocclusion rate than urokinase. Corilagin significantly inhibited PAI-1 activity in rat plasma or platelet-released substances while it elevated plasma tPA activity, in a concentration-dependent manner. Corilagin, however, had no influence on rabbit platelet aggregation. It is indicated that corilagin inhibited PAI-1 activity and increased tPA activity, and this property of corilagin is assumed to be responsible for the thrombolytic effect. Abbreviations. PO:persistent occlusion CR:cyclic reflow PP:persistent patency PAI-1:type 1 plasminogen activator inhibitor tPA:tissue-type plasminogen activator PBS:phosphate buffer solution IC (50):50 % of inhibitory concentration PRP:platelet-rich plasma ADP:adenosine diphosphate AA:arachidonic acid PAF:platelet-activating factor

Prognosis of central retinal artery occlusion: local intraarterial fibrinolysis versus conservative treatment.

BACKGROUND AND PURPOSE: Local intraarterial fibrinolysis (LIF) is one of several methods used in treating central retinal artery occlusion (CRAO). We investigated whether LIF is more effective than conservative methods in the treatment of CRAO. METHODS: In this retrospective study, a total of 178 patients (125 men and 53 women) with CRAO were treated at the Eye Hospital of the University of Freiburg from 1980 to 2000. The average age of the patients was 66.8 years (SD, 12 years). In group I, 116 patients were treated conservatively by anterior chamber paracentesis, massage of the globe, isovolemic hemodilution, acetazolamide, Pentoxifyllin, acetylsalicylic acid, and reduction of arterial hypertension. Some combination but not all of the mentioned conservative methods were used in the conservatively treated patients. In group II, 62 patients receiving LIF received local injection of urokinase or recombinant tissue plasminogen activator into the proximal part of the ophthalmic artery. In case of ipsilateral carotid artery occlusion or high grade stenosis (14 of 62 patients), the thrombolytic agent was administered into the internal maxillary artery. RESULTS: Among 178 patients, the CRAO was subtotal in 130 (73.0%), incomplete in 39 (21.9%), and total in nine (5.1%). Statistical calculations showed a significantly better visual acuity in group II patients, who were treated with LIF, in comparison with group I patients, who were treated conservatively (P =.0022). CONCLUSION: For patients with CRAO, LIF is superior to conservative treatment.

Combined cataract extraction and submacular blood clot evacuation for globe perforation caused by retrobulbar injection.

A 45-year-old woman, originally scheduled for cataract surgery in the left eye, was referred for management of a globe perforation noticed after the retrobulbar injection of an anesthetic solution. There was a moderate degree of vitreous hemorrhage, and initial visual acuity was hand movement. A submacular blood clot of about 4-disc diameter was detected when the vitreous hemorrhage gradually cleared. One week after the incident, combined phacoemulsification, intraocular lens implantation, pars plana vitrectomy, and submacular clot removal using tissue plasminogen activator (tPA) as an adjunct were performed. Recovery was uneventful. At the last follow-up 6 months after surgery, best corrected visual acuity was 20/30.

Use of glycoprotein IIb/IIIa inhibition plus fibrinolysis in acute myocardial infarction.

Pharmacological reperfusion therapy for acute myocardial infarction with intravenous fibrinolytic agents improves survival yet fails to achieve early and complete coronary blood flow in nearly half of treated patients. In principle, glycoprotein (GP) IIb/IIIa inhibitors, potent antiplatelet agents, might improve the efficacy and clinical outcomes associated with fibrinolysis. Preclinical research suggests more rapid and effective reperfusion with combined platelet GP IIb/IIIa inhibition and fibrinolysis. Early clinical studies confirm improved early patency and more rapid electrocardiographic resolution, but increased bleeding complications, with the addition of GP IIb/IIIa antagonists to conventional fibrinolysis. Future studies may combine reduced-dose fibrinolytic therapy with GP IIb/IIIa inhibition to optimize efficacy and safety.

High-dose intradialytic urokinase to restore the patency of permanent central vein hemodialysis catheters.

From November 1, 1995, to April 30, 1997, in our outpatient dialysis facility, 7,179 or 24.3% of hemodialyses were performed with soft, cuffed, intravenous catheters as blood accesses. Inadequate blood flow (pump speed < 400 mL/min) was noted in 286 instances (4.0%). Locking of catheter lumina with 5,000 to 9,000 IU urokinase was only partly successful in three of 21 cases. Infusions of 20,000 to 40,000 IU urokinase in 25 instances during dialysis restored catheter function in 10 cases. In nine instances in which blood could not be aspirated from the catheter and dialysis could not be performed, the infusion was done through the catheter while the patient remained in the chair. In eight instances, the catheter was opened, and dialysis was performed on the next shift. In 162 instances, a new method was used to open failing catheters most conveniently, efficiently, and with minimal cost. Whenever a nonpositional deterioration of blood flow was noted, 250,000 IU urokinase was infused during dialysis over 3 hours, if there were no contraindications. Full restoration of pump speed was achieved during 132 infusions; in another 21 cases, blood flow improved. In 59 cases, in which an adequate pump speed was not achieved during the next dialysis, the infusion was repeated with restoration of blood flow in 50 instances and flow improvement in six; infusion was re-repeated in the nine instances without complete restoration of flow and in one of the 50 in which restoration of flow was temporary. Adequate flow was restored in nine of these 10 cases in which re-repeated infusion was done. Routine doses of heparin were used concomitantly with urokinase in all cases. No adverse reaction to urokinase has been encountered in any case. To maintain long-term catheter patency, warfarin therapy was started in patients who required repeated urokinase infusions. Vials of 250,000 IU, 9,000 IU, and 5,000 IU urokinase cost $358.47, $77.07, and $43.76, respectively. The higher cost of high-dose intradialytic urokinase as compared with the catheter "lock" is offset by the high probability of positive results, saving of nursing and patient time, and saving on transportation expenses. The convenience and cost are even more remarkably in favor of intradialytic urokinase compared with catheter stripping ($2,433) or surgical replacement ($3,060).

Various problems during long-term percutaneous cardiopulmonary support.

A 54-year-old man with a left ventricular free wall rupture following acute anterior myocardial infarction underwent a repair surgery with percutaneous cardiopulmonary support (PCPS). During surgery and postoperatively, PCPS provided sufficient support flow. The patient was successfully weaned from PCPS on the 15th postoperative day and discharged subsequently. In the management of cardiac rupture patients, PCPS has the merit of preventing rupture progression and the advantage of recovery of pulmonary function. However, there are several problems to solve. The support effectiveness and recovery of the patient's heart should be carefully evaluated. Effective left heart decompression also needs to be established. Heparin-coated circuits still need proper anticoagulation treatment to prevent thrombus formation especially while support flow is low. A circuit construction that allows easier maintenance and safer exchange of oxygenators and pump heads is suggested. Ischemia of the cannulated leg should be prevented by femoral artery perfusion.

Thrombolytic therapy with tissue plasminogen activator for prevention of vasospasm in experimental subarachnoid hemorrhage: its efficacy and problems.

We investigated the efficacy of two different tissue plasminogen activators (t-PA) for preventing vasospasm after experimental subarachnoid hemorrhage (SAH) in rabbits. Intrathecal injection of Silteplase and Alteplase showed significant preventive action against vasospasm following SAH and thrombolytic effect. The low dose groups with both t-PA showed more preventive action on day 1 than the high dose groups. The data suggest that the determination of optimum dose of t-PA is essential in clinical use of t-PA.

Induction of thrombolysis and prevention of thrombus formation by local drug delivery with a double-occlusion balloon catheter.

The efficacy of the local delivery of an antithrombotic drug in preventing thrombosis and enabling thrombolysis was investigated in 29 dogs. An antithrombotic drug (heparin, 25 U/kg), or an antithrombin (argatroban, 0.05 mg/kg) was infused into injured canine iliac arteries, using a double-occlusion balloon catheter, and the preventive effect of the drug was evaluated. Local delivery of low-dose tissue-type plasminogen activator (t-PA; Tisokinase, 50,000 U; Kowa, Nagoya and Asahi Chemical Industries, Fuji, Japan) into thrombosed canine iliac arteries, using the same catheter, or intravenous infusion of low-dose or high-dose t-PA (30,000 U/kg) was also performed. Angiographically, stenotic thrombosis was 2% by local delivery of argatroban and 7% by local delivery of heparin (P < 0.01 vs each control; 47% and 51% respectively). Thrombotic stenosis, as observed by angiography, decreased from 91% to 9% after local delivery of t-PA, and from 94% to 52% in controls. Local delivery of t-PA effectively reduced the thrombus size (P < 0.01 vs control). After systemic intravenous delivery of low-dose t-PA, no reduction of residual thrombotic stenosis, was observed. Reduction of residual thrombotic stenosis after intravenous delivery of high-dose t-PA, was similar to that achieved by local delivery of the drug. Angioscopy demonstrated a similar trend. High-dose drug delivery reduced systemic coagulability. Local delivery of an antithrombotic drug, using a double-occlusion balloon catheter, effectively prevented thrombus formation, and local delivery of t-PA induced thrombolysis without exerting a significant influence on coagulability.

Comparative thrombolytic properties of tissue-type plasminogen activator (t-PA), single-chain urokinase-type plasminogen activator (u-PA) and K1K2Pu (a t-PA/u-PA chimera) in a combined arterial and venous thrombosis model in the dog.

The chimeric molecule K1K2Pu, comprising the two kringle domains (K1 and K2) of tissue-type plasminogen activator (t-PA) and the COOH-terminal region with the serine protease domain (Pu) of urokinase-type plasminogen activator (u-PA), was previously shown to have a 5- to 10-fold reduced clearance rate with maintained specific thrombolytic activity, resulting in an increased thrombolytic potency in animal models of venous and arterial thrombosis. To document the thrombolytic potential of K1K2Pu, the thrombolytic potency and fibrin specificity were studied in a combined platelet-rich arterial eversion graft thrombosis and venous whole blood clot model in heparinized dogs (100 U/kg bolus and 50 U/kg per h infusion). Dose-response effects of bolus injections of K1K2Pu (0.032 to 0.25 mg/kg) were compared with those of recombinant t-PA (rt-PA) and of recombinant single chain u-PA (rscu-PA) (0.25 to 1.0 mg/kg each) in groups of five or six dogs, each given heparin with or without the thromboxane synthase inhibitor/prostaglandin endoperoxide receptor antagonist ridogrel. Heparin and ridogrel in the absence of a thrombolytic agent did not produce arterial reflow or venous clot lysis in five dogs. Addition of K1K2Pu, rt-PA or rscu-PA resulted in a dose-dependent induction of arterial reflow and of venous clot lysis in the absence of systemic fibrinolytic activation and fibrinogen breakdown. Consistent arterial reflow required 0.063 mg/kg of K1K2Pu and 0.5 mg/kg of rt-PA or of rscu-PA. The thrombolytic potency for venous clot lysis, expressed as percent lysis per mg compound administered per kg body weight, was (mean +/- SEM) 750 +/- 160 for K1K2Pu, 68 +/- 17 for rscu-PA (p less than 0.001 vs. K1K2Pu) and 110 +/- 29 for rt-PA (p less than 0.001 vs. K1K2Pu). The plasma clearance rates were significantly lower for K1K2Pu than for rscu-PA and rt-PA. In the absence of ridogrel, arterial reflow was significantly slower and was followed by cyclic reocclusion and reflow; however, venous clot lysis was unaffected. Template bleeding times were not significantly altered in the absence but were markedly prolonged in the presence of ridogrel. These results confirm and establish that, when given as a bolus injection, K1K2Pu has an approximately 10-fold higher thrombolytic potency for arterial and venous thrombolysis than does rt-PA or rscu-PA. Thrombolysis with K1K2Pu is obtained in the absence of systemic fibrinolytic activation and fibrinogen breakdown. These properties suggest that K1K2Pu offers potential for thrombolytic therapy by bolus administration in patients with thromboembolic disease.