Fibrinolytic therapy with low-dose recombinant tissue plasminogen activator in retinal vein occlusion

In a retrospective study the outcome of patients treated by the Kapandji-Sauvé procedure was evaluated. In the period from 1989 to 1993, 18 patients were operated. The arthrodesis of the distal radioulnar joint was performed by a dorsoulnar incision using one screw. A 2 cm long segment of the ulna was resected. Indications for Kapandji-Sauvé procedures were in 12 cases deformities subsequent to wrist fractures, in three cases osteoarthrosis of the distal radioulnar joint, in two cases Madelung's deformity and in one case Kienb?ck's disease. The mean follow-up time was 5.1 years (range 3 to 7 years). There was one case of reossification, which required reoperation. No other complications were seen. An excellent result was obtained in seven patients, a good result in nine patients, one patient showed satisfactory and one poor results. Grip strength was normal in six cases, reduced up to 20% in seven cases and reduced up to 50% in five cases. 13 patients returned to their previous occupation. 12 patients showed a range of pronation-supination of more than 150 degrees. There was no correlation between X-ray findings and clinical outcome in patients.     

Pulse-spray treatment of subclavian and jugular venous thrombi with recombinant tissue plasminogen activator

PURPOSE: To evaluate the efficacy of recombinant tissue plasminogen activator (rtPA) injected by pulse-spray in lysing subclavian and jugular venous thrombi. MATERIALS AND METHODS: Twelve patients with symptomatic, venogram-confirmed, occlusive thrombi of the subclavian-axillary or jugular veins were treated with one or two daily 15-minute injections of rtPA delivered directly into the clots with pulse-spray catheters. Twenty-four hours after each treatment, repeated venograms were obtained to assess venous patency. Successful thrombolysis was defined as antegrade flow through the previously occluded segments with minimal collateral venous flow. Continued patency was assessed with repeated venograms obtained after 1 and 2 months of oral anticoagulation. RESULTS: The 15-minute rtPA injections successfully lysed thrombi in eight of the 12 patients. Hypofibrinogenemia developed in only one patient. The technique had a high success rate with thrombi less than 2 weeks old (seven of eight) regardless of the length of the clot, but had limited success with thrombi more than 2 weeks old (one of four). Continued patency over a 2-month interval was documented in four of the eight patients whose thrombi were successfully lysed. However, patency could be maintained in only one of the four patients who retained a venous access device in the treated vein. CONCLUSION: Pulse spray rtPA is an effective, safe, and practical alternative to continuous infusions of thrombolytic agents to treat upper extremity venous thrombi.     

Urokinase but not tissue plasminogen activator mediates arterial neointima formation in mice

To define the role of the plasminogen activators (PAs) tissue PA (t-PA) and urokinase PA (u-PA) in vascular wound healing, neointima formation and reendothelialization were evaluated after electric or mechanical arterial injury in mice with a single or combined deficiency of t-PA (t-PA-/-) and/or u-PA (u-PA-/-). In both models, neointima formation and neointimal cell accumulation were reduced in u-PA-/- and in t-PA-/-/u-PA-/- arteries but not in t-PA-/- arteries. The electric injury model was used to characterize the underlying cellular mechanisms. Topographic analysis of vascular wound healing in electrically injured wild-type and t-PA-/- arteries revealed a similar degree of migration of smooth muscle cells from the noninjured borders into the necrotic center. In contrast, in u-PA-/- and t-PA-/-/u-PA-/- arteries, smooth muscle cells accumulated at the uninjured borders but failed to migrate into the necrotic center. Cultured u-PA-/- but not t-PA-/- smooth muscle cells also failed to migrate in vitro after scrape wounding. Proliferation of smooth muscle cells was not affected by PA deficiency. Reendothelialization after electric injury was similar in all genotypes. In situ analysis revealed markedly elevated u-PA zymographic activity, mRNA, and immunoreactivity in smooth muscle cells, endothelial cells, and leukocytes within 1 week after injury, eg, when cells migrated into the wound. Thus, u-PA plays a significant role in vascular wound healing and arterial neointima formation after injury, most likely by affecting cellular migration.     

An autopsy case of intracranial hemorrhage during tissue plasminogen activator infusion

A comprehensive classification system has been proposed by the AO/ASIF Foundation for the classification of long bone fractures. After an explanatory talk and with the aid of an illustrated pamphlet, 18 orthopaedic surgeons were asked to classify 10 long bone fractures according to the AO system. Three of the participating surgeons had previous experience of the classification system. After individual classification, a consensus classification was derived and the results of the individual and consensus codings were compared. Only 32 per cent of all codings agreed with the final consensus. There was no difference between the surgeons with previous experience of the system (66 per cent) and novice coders (69 per cent) in the number of inaccurate codes when compared with the consensus codes. Reasons for error in coding are discussed. It is recommended that if the AO system is used for the purposes of research and computer-based audit, a consensus of opinion is used as the basis of classification.     

Phase I study of intraventricular recombinant tissue plasminogen activator for treatment of posthaemorrhagic hydrocephalus

AIM: Phase I study to evaluate intraventricular fibrinolytic treatment with recombinant tissue plasminogen activator (tPA) as a method of clearing blood from the cerebrospinal fluid, and thus preventing permanent hydrocephalus. METHODS: Twenty two preterm infants, aged 7 to 26 days, with progressive posthaemorrhagic ventricular dilatation (ventricular width > 4 mm over 97th centile) received one to five intraventricular bolus injections of 1.0 mg or 0.5 mg tPA at intervals of one to seven days. RESULTS: The mean cerebrospinal fluid concentration of tPA 24 hours after 1 mg was 1860 micrograms/ml. The half life of tPA in cerebrospinal fluid was about 24 hours. Twenty one (95%) infants survived, 12 (55%) without shunt surgery. One infant had secondary intraventricular haemorrhage. CONCLUSION: Intraventricular tPA resulted in survival without a shunt for most of the infants, but with some risk. Failure may have been due to plasminogen deficiency, an inhibitor, or late intervention.     

Coordinated expression of tissue-type plasminogen activator and plasminogen activator inhibitor type 1 during corpus luteum formation and luteolysis in the adult pseudopregnant rat

Proteolytic activity generated by the plasminogen activator (PA) system is associated with many biological processes. Using an adult pseudopregnant rat model, we have studied how two components of the PA system, tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor type 1 (PAI-1), are expressed temporally and spatially during different developmental stages of the corpus luteum (CL). Northern blot analysis, in situ hybridization, in situ zymography, and fibrin overlay were used to analyze the expression and distribution of tPA and PAI-1 messenger RNA (mRNA) as well as PA activity in CL of different ages. We demonstrated that during the luteinization period (approximately days 1-2), tPA mRNA was highly and evenly expressed in newly formed CL, whereas PAI-1 mRNA was mainly detected in the central part of the same CL. In accordance with these findings, proteolytic activity generated by tPA was detected in the outer region of newly formed CL by in situ zymography. During the luteotropic period (approximately days 3-10), tPA mRNA expression was very low. PAI-1 mRNA expression was also low, but increased on day 10. As expected, proteolytic activity was very low during this period. During functional luteolysis (days 13-14) and subsequent structural luteolysis, tPA mRNA was elevated. PAI-1 mRNA was also expressed during this period. Moreover, the net PA activity, as determined by fibrin overlay, was relatively high during this period. Our studies indicate that tPA and PAI-1 are coordinately expressed in the CL, resulting in increased proteolytic activities during the luteinization and luteolytic periods. PA-mediated proteolysis may, therefore, play a role in both CL formation and luteolysis in rats.     

Acute band-shaped keratopathy after intraocular fibrinolysis with recombinant tissue plasminogen activator (rt-PA)

The study was planned to determine the proportion of parents that wish to know the sex of their fetus at the 20-week anomaly scan, and to investigate our ability to diagnose correctly the sex of the fetus when undertaken as part of a routine scan. A total of 472 patients gave their informed consent. An attempt was made to identify the genitalia as part of the routine scan. No extra time was allowed to determine the sex of the fetus. Altogether 353 (74.7%) women wanted to know the sex, of which four (0.9%) wanted to know but did not want their partners to know. In 50 (10.6%) cases, it was not possible to determine the fetal sex in the time allowed. When the sex was identified, it was correct in 408 (96.7%) cases, and incorrect in 14 (3.3%) cases. Where the parents wanted to know the sex of the fetus, 24 (6.8%) scans were inconclusive, 319 (97%) were correctly identified, and ten (3%) were incorrectly identified (six male, four female). There were no terminations of pregnancy. The majority of prospective parents wish to know the sex of their child, and, in most cases, it is possible to determine the fetal sex at the time of the routine anomaly scan. During the time allowed, the fetal sex was undetermined in one in ten cases, and 3% were sexed incorrectly. If parents wish to know the gender of their fetus, it would appear reasonable to provide this information, provided that the parents are aware of the failure and error rates of sex identification using ultrasound.     

Treatment of hepatic venocclusive disease with recombinant human tissue plasminogen activator and heparin in 42 marrow transplant patients

The purpose of this report is to review the Fred Hutchinson Cancer Research Center experience of treating patients with venocclusive disease of the liver (VOD) after marrow transplantation using recombinant human tissue plasminogen activator (rh-tPA) and heparin. The charts of 42 patients who had received rh-tPA and heparin for the treatment of VOD between February 1991 and December 1995 were reviewed. Response to rh-tPA and heparin was defined as a reduction in total serum bilirubin by 50% within 10 days of starting treatment. Total serum bilirubin, percent weight gain, and serum creatinine before, after, and at the start of rh-tPA and heparin were examined to determine whether these laboratory values distinguished patients who responded to treatment from those who did not. We also evaluated whether evidence of multiorgan failure (requirement for supplemental oxygen, requirement for hemodialysis, requirement for mechanical ventilation) or whether the calculated probability of a fatal outcome from VOD could discriminate responders from nonresponders. In addition, the incidence and outcome of bleeding as a major complication of thrombolytic therapy was examined. Twelve patients responded to rh-tPA and heparin and 30 patients did not. There were no statistically significant differences between responders and nonresponders in the day treatment was started, dose of rh-tPA, total serum billirubin, and percent weight gain before, after, or at the start of treatment, or the calculated probability of dying from VOD on the day treatment with rh-tPA and heparin was begun. More nonresponding patients required dialysis or mechanical ventilation (11 of 30) before or at the start of rh-tPA and heparin than responding patients (0 of 12), P = .0183. Serum creatinine was greater at the start of treatment in nonresponding patients (1.9 +/- 1.3 mg/dL) than in responding patients (1.1 +/- 0.4 mg/dL), P = .0794. Ten patients had severe bleeding episodes, which resulted in death in three patients and may have contributed to death in an additional three patients. Treatment for VOD using rh-tPA and heparin was successful in 29% of patients but was associated with a significant risk of life-threatening hemorrhage. Requirement for supplemental oxygen, dialysis, or mechanical ventilation before the start of treatment were prognostic indicators of no response to thrombolytic therapy. We do not recommend treatment using tPA and heparin in patients with severe VOD who have already developed multiorgan dysfunction.     

Recombinant tissue type plasminogen activator treatment of thrombosed mitral valve prosthesis during pregnancy

PURPOSE: Prosthetic heart valve thrombosis occurring during pregnancy is a life-threatening complication. Surgical treatment requires clot removal under cardiopulmonary bypass (CPB) and carries a high mortality. We describe the successful use of thrombolytic therapy for recurrent thrombosed valve prosthesis in a pregnant patient. CLINICAL FEATURES: A 32-yr-old patient whose pregnancy was complicated by two episodes of a thrombosed St Jude mitral prosthesis is reported. The first episode occurred at 20 wk of pregnancy during the change of oral anticoagulant therapy (acenocoumarol 4 mg a day) to sc heparin. As the patient was in cardiogenic shock, the valve thrombus was treated by clot removal under CPB., with a cross clamp time of 32 min, a perfusion pressure above 70 mmHG. There was no fetal cardiac rhythm during CPB which lasted < 45 min. The second episode occurred at the 28th gestational week in a patient in cardiogenic shock and because reoperation was thought to carry too high a risk, the thrombus was successfully treated with 50 mg recombinant tissue plasminogen activators (rtPA) i.v. Following this, the course of pregnancy was uneventful and carried to term and the patient delivered vaginally. Pain relief was achieved with intravenous patient-controlled analgesia with alfentanil (bolus 100 mug; lock out = five minutes). Although rtPA has been used before, this is the first report in which pregnancy was carried to term and standard vaginal delivery performed. CONCLUSION: This case provides evidence for the efficacy and relative safety of rtPA as thrombolytic therapy in the treatment of haemodynamically compromised valve heart thrombosis in pregnancy.     

A refined kinetic analysis of plasminogen activation by recombinant bovine tissue-type plasminogen activator indicates two interconvertible activator forms

Bovine tissue-type plasminogen activator (tPA) was heterologously expressed in the methylotrophic yeast Pichia pastoris and characterized structurally and kinetically. The bovine single-chain tPA-mediated activation of bovine plasminogen was studied in the presence and absence of fibrinogen fragments. We have proposed a refined new method of kinetic analysis which allows examination of both stationary and prestationary phases of this process. The investigation revealed the presence of two interconvertible forms of the recombinant bovine tPA being in equilibrium at a 1 to 50 ratio. Only the minor form was able to bind and activate plasminogen. Saturation of the whole pool of tPA required high plasminogen concentration (Km >/= 5 microM) in order to reverse the equilibrium between the two forms. Fibrinogen fragments activated the single-chain tPA due to preferential binding and stabilization of the minor "active" form of the enzyme until all the molecules of tPA were converted. The same mechanism could be applied to human tPA as well. The Km values, obtained for recombinant bovine and human tPA in the presence of fibrinogen fragments, were found to be similar (Km = 0.1 microM) while kcat of human tPA was 5-10 times higher.     

Gene polymorphisms for plasminogen activator inhibitor-1/tissue plasminogen activator and development of allograft coronary artery disease

BACKGROUND: Impaired fibrinolytic activity has been linked to the presence and severity of allograft vasculopathy (Tx CAD). This impairment may be associated with the presence of certain fibrinolytic protein gene polymorphisms. METHODS AND RESULTS: To investigate the relation between donor-specific fibrinolytic protein genotypes and Tx CAD, we identified donor plasminogen activator inhibitor-1 (PAI-1) HindIII and tissue plasminogen activator (TPA) EcoRI restriction fragment length polymorphisms-based genotypes by Southern blot analysis in 48 recipients of cardiac allografts and correlated these genotypes with the development of CAD. No association was found between donor TPA genotypes and the presence of Tx CAD. Among the 48 patients, 17% were homozygous for the 1/1 PAI-1 genotype, 51% for the 2/2 PAI-1 genotype, and 32% for the 1/2 PAI-1 genotype. The actuarial freedom from any CAD for the recipients with each respective donor PAI-1 genotype at 12 and 24 months was 100% and 100% for the 1/1 PAI-1 genotype, 92% and 92% for the 1/2 PAI-1 genotype, and 75% and 45% for the 2/2 PAI-1 genotype (P=0.03). Recipients with a diseased 2/2 PAI-1 genotyped allograft had longer ischemic times (P=0.02) than those recipients with a Tx CAD-free allograft. CONCLUSIONS: These data suggest that recipients with a 2/2 PAI-1 genotype are at a significant risk of developing Tx CAD. This genotype may serve as a useful screening tool for predicting the future development of Tx CAD.     

Acceleration of plasminogen activation by tissue plasminogen activator on surface-bound histidine-proline-rich glycoprotein

Histidine-proline-rich glycoprotein (HPRG), also known as histidine-rich glycoprotein, is a major plasminogen-binding protein. In this work we characterized extensively the circumstances under which HPRG accelerates plasminogen activation and the specificity of this effect. Soluble HPRG did not significantly influence plasminogen activation. In contrast, native HPRG bound to hydrazide or nickel chelate surfaces strongly stimulated the activation of plasminogen by tissue plasminogen activator, but not by urokinase or streptokinase. The efficiency of activation on surface-bound HPRG was increased for Glu-plasminogen (41-fold), Lys-plasminogen (17-fold), and cross-linked Glu-plasminogen (11-fold) but not for mini-plasminogen, and was mainly due to a decrease in the apparent Km. A reduced susceptibility to inhibition by chloride ions contributed to the higher activation rate of Glu-plasminogen on an HPRG surface. The immobilized N- and C-terminal domains, but not the histidine-proline-rich domain of HPRG, also bound plasminogen and stimulated its activation. HPRG-enhanced plasminogen activation was proportional to the quantity of HPRG immobilized and was abolished by anti-HPRG antiserum, by low concentrations of epsilon-aminocaproic acid, by methylation of lysine residues in HPRG, and by treatment of HPRG with carboxypeptidase B. Soluble HPRG and a plasminogen fragment, kringle 1-2-3, acted as competitive inhibitors by binding to plasminogen and immobilized HPRG, respectively. The interaction of the conserved C-terminal lysine of HPRG with the high affinity lysine binding site of plasminogen is necessary and sufficient to accelerate plasminogen activation. Unlike other stimulators of plasminogen activation, the effect of HPRG on fibrinolysis is modulated by factors that influence the equilibrium between solution and surface-bound HPRG.     

Choroidal hemorrhage associated with systemic tissue plasminogen activator

PURPOSE: To determine the cause of spontaneous choroidal hemorrhage in a 67-year-old man after a myocardial infarction and administration of tissue plasminogen activator. METHODS: The patient underwent ocular examination. RESULTS: The patient retained excellent visual acuity and the choroidal hemorrhage resolved completely within two months. CONCLUSION: The administration of tissue plasminogen activator was responsible for the large extent of hemorrhage and should be considered in the differential diagnosis of hemorrhagic choroidal detachment.     

Pneumatic displacement of subretinal hemorrhage without tissue plasminogen activator

PURPOSE: To analyze the results of excimer laser phototherapeutic keratectomy (PTK) combined with simple excision in recurrent pterygium to minimize the recurrence rate and obtain a smooth corneal surface. SETTING: Veni Vidi Eye Health Centre, Istanbul, Turkey. METHODS: Combined pterygium excision and excimer laser PTK was performed in 22 eyes with recurrent pterygium (22 patients). Both spot and scan modes of the Meditec MEL 60 excimer laser were used to produce a wide ablation layer (depth 40 to 80 microns). RESULTS: During the mean follow-up of 16.5 months (range 6 to 27 months), visual acuity, refraction, slitlamp, and corneal topography examinations were recorded. Pterygium recurred in only 1 eye (4.5%). Postoperative visual acuity improved in 15 eyes (68.2%). Keratometric readings were not accurately measured preoperatively because of corneal surface irregularities but could be easily taken after the surgery. Corneal astigmatism ranged from 0 to 2.00 diopters (D) (mean 1.23 D). Three months after surgery, no haze persisted in any eye. No significant intraoperative or postoperative complication was detected. CONCLUSIONS: Excimer laser PTK appears to simplify pterygium surgery because a superficial keratectomy is sufficient to remove pterygium. The excimer laser can be used to ablate the visible residual tissues and smooth the corneal surface, resulting in good postoperative refraction and visual acuity. Consequently, this procedure seems to be effective and safe.     

Recombinant murine cell lines, transformed by various vectors based on bovine type 1 papillomavirus and expressing human tissue plasminogen activator. II. Analysis of cell lines, producing recombinant tissue plasminogen activator

We have characterized a number of recombinant cell lines established with BPV1 and Lx1 (containing duplication of LCR-E6-E7 sequence) vectors on the basis of C127 cells. It had been shown that Lx1 based vectors possess the higher number of intracellular copies than analogous vectors on the basis of wtBPV, and most part of them is integrated into the host genome. Using various concentrations of heavy metal salts we have developed the optimized procedure for induction of recombinant tPA synthesis which is controlled by the mouse MT1 promoter. A 8-fold increase of rtPA concentration was reached in the course of induction. It had been shown that native and non-glucosylated forms of recombinant and human tPA are identical in their properties.     

In vitro urokinase type plasminogen activator levels and total plasminogen activator activity in squamous cell carcinomas of the head and neck

OBJECTIVE: Determine total plasminogen activator (PA) activity and urokinase-type plasminogen activator (u-PA) levels in cell-free supernatants derived from primary and metastatic squamous cell carcinoma of the head and neck. DESIGN: Plasminogen activator activity was measured by spectrophotometric assay with chromogenic substrate Val-Leu-Lys-para-nitroanilide. Urokinase-type plasminogen activator levels were measured with enzyme-linked immunosorbent assay technique. RESULTS: Fourteen established squamous cell carcinoma lines from patients with head and neck cancer were assayed for both total PA activity and u-PA levels at 24 to 48 hours of incubation. Compared with control and fibroblast-conditioned media, cell lines established from squamous cell carcinoma of the head and neck had significantly (P < .005) higher levels of both total PA activity and u-PA levels. Linear regression analysis showed a positive correlation (r = .65, P = .007) between total PA activity and u-PA levels. CONCLUSIONS: Squamous cell carcinomas of the head and neck are able to activate plasminogen and produce u-PA in vitro. The production of PA by squamous cell carcinomas of the head and neck may play an important role in the biology of invasion and metastasis.