Differences of proteolytic enzymes and pathological changes in permissive and nonpermissive animal hosts for Angiostrongylus cantonensis infection.

In this study, mice (nonpermissive hosts) infected with Angiostrongylus cantonensis showed significant worm degeneration and eosinophil degranulation, whereas infected rats (permissive hosts) showed lower worm degeneration and eosinophil degranulation. Pathophysiological changes developed to a lesser extent in rat than in the mouse strains. Neurological evaluation of A. cantonensis-infected mice showed mechanical damage caused by worms migrating to the brain. A significant correlation between the proteolytic enzymes, plasminogen activator (PA) and matrix metalloproteinase-9 (MMP-9), and pathological changes was found in hosts with eosinophilic meningitis or meningoencephalitis. Also, the ratio of cerebrospinal fluid (CSF) to serum albumin was consistently increased in hosts with angiostrongyliasis as compared with control. These data clearly indicate that PA and MMP-9 proteolytic enzymes as well as pathological changes are different in permissive and nonpermissive hosts.

CSF levels of growth factors and plasminogen activators in leptomeningeal metastases.

OBJECTIVE: To investigate the diagnostic value of transforming growth factor beta(1) (TGFbeta(1)), vascular endothelial growth factor (VEGF), urokinase-type plasminogen activator (uPA), and tissue-type plasminogen activator (tPA) in CSF for leptomeningeal metastasis (LM). METHODS: The authors measured concentrations of biomarkers by ELISA in matched samples of CSF and serum, collected from 132 patients with a solid malignancy with LM (n = 19) and without LM (n = 54) and patients with viral (n = 16) and bacterial (n = 16) meningitis and a variety of nonmalignant, noninfectious neurologic disorders (n = 27). Indexes of the biomarkers (CSF/serum value relative to CSF/serum albumin ratios) were calculated to correct for the serum contribution to the CSF marker concentration. RESULTS: CSF VEGF concentration was significantly higher in LM than in all other groups. VEGF indexes were also higher, although not significant. In contrast, the tPA index was significantly decreased in LM compared with all other groups. The combination of the VEGF and tPA indexes resulted in a sensitivity of 100% for LM and a specificity of 73% for the patient group with a primary tumor but without LM. CONCLUSION: Patients with leptomeningeal metastasis have high vascular endothelial growth factor (VEGF) indexes and low tissue-type plasminogen activator (tPA) indexes. As cytologic examination of CSF lacks 100% sensitivity for the diagnosis of leptomeningeal metastasis (LM), the combination VEGF and tPA index analysis may be of additional value in the diagnostic workup of patients suspected of having LM.

Association of plasminogen activators and matrix metalloproteinase-9 proteolytic cascade with blood-CNS barrier damage of angiostrongyliasis.

Blood-central nervous system (blood-CNS) barrier breakdown, an important pathophysiological event in meningitis, results in extravasation of leucocytes into subarachnoid space. The blood-CNS barrier disruption is mediated by primarily two enzyme systems, the plasminogen activators (PAs) and matrix metalloproteinases (MMPs). The present study showed that the activities of tissue-type PA (tPA), urokinase-type activator (uPA) and MMP-9 in cerebrospinal-like fluid (CSF-like fluid) were significantly increased in mice with eosinophilic meningitis compared with uninfected mice. Eosinophilia significantly correlated with tPA, uPA and MMP-9 activities, and albumin concentration. In addition, when GM6001, a specific matrix metalloproteinase blocker, was injected into infected mice, MMP-9 activity and total protein concentrations declined from their preinjection highs. These results suggest that the PAs and MMP-9 proteolytic cascade may be associated with blood-CNS barrier disruption in eosinophilic meningitis caused by Angiostrongylus cantonensis.

Elevation of plasminogen activators in cerebrospinal fluid of mice with eosinophilic meningitis caused by Angiostrongylus cantonensis.

A hallmark of parasitic meningitis is the infiltration of eosinophils into the subarachnoid space. Infection with Angiostrongylus cantonensis in mice induced proteinase activity in parallel with the pathological changes of eosinophilic meningitis. Zymogram analysis demonstrated that 70 and 55 kDa proteinases from cerebrospinal fluid (CSF) were active against the casein/plasminogen substrate. The proteinase activities were clearly inhibited by phenylmethanesulphonyl fluoride but not by ethylenediamine tetraacetic acid, 1,10-phenanthroline or leupeptin. Western blotting confirmed these enzymes to be tissue-type plasminogen activator and urokinase-type plasminogen activator, respectively. High activities of tissue-type plasminogen activator and urokinase-type plasminogen activator were detected in the CSF of mice with eosinophilic meningitis, and correlated positively with CSF eosinophil numbers and total protein, respectively. Immunohistochemistry demonstrated that tissue-type plasminogen activator and urokinase-type plasminogen activator localised in the endothelial cells of blood vessels, in blood clots and in infiltrated leukocytes. These results suggest that tissue-type plasminogen activator and urokinase-type plasminogen activator may be play a role in the pathogenesis of eosinophilic meningitis of angiostrongyliasis.

Tissue plasminogen activator levels after single intracisternal injection in patients with subarachnoid hemorrhage.

Tissue plasminogen activator (tPA) levels were investigated in the cisternal fluid of patients with subarachnoid hemorrhage treated with single intracisternal injection of recombinant tPA during radical surgery for ruptured aneurysms. Seven patients received different doses of tPA: two of 400 microg/ml, three of 500 microg/ml, one of 700 microg/ml, and one of 800 microg/ml in a total amount of 20 ml distilled water at pH 7. Cerebrospinal fluid samples were taken directly from the cisternal fluid at 15-minute incubation after injection, immediately after irrigation during surgery, and by lumbar tap 2 days after surgery. Cisternal tPA levels decreased to about 60% of the mean injected doses after 15-minute incubation. Simple linear regression analysis showed these tPA levels after incubation correlated with the initial doses. After copious irrigation with Ringer solution at pH 8, tPA levels decreased rapidly without correlation with the initial doses. After spinal drainage for 2 days, tPA levels further decreased by an order of 10(-4) to 10(-6) from the initial dose. These values were still greater than normal controls. The final values of tPA levels were not related to the initial dose. None of the patients suffered from systemic or wound complications. Cisternal tPA injection with increased doses and irrigation may be beneficial for the selective rapid removal of blood clots with controllable safety.

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.

Coagulation and fibrinolysis in blood and cerebrospinal fluid after aneurysmal subarachnoid haemorrhage: effect of tranexamic acid (AMCA).

Serial assays of blood coagulation factors as well as of fibrin/fibrinogen degradation products (FDP) and plasminogen activatory activity (PA) on fibrin plates in blood and cerebrospinal fluid (CSF) were performed in 41 consecutive patients with recently ruptured cerebral aneurysms, 21 of whom were randomly treated with tranexamic acid (AMCA). Coagulation factors were unaffected by the drug and plasminogen and FDP decreased in blood after two weeks' treatment. After one week, PA in CSF was increased in control patients and unchanged in AMCA-treated patients, whereas CSF-FDP had decreased among AMCA-treated patients. After two weeks PA as well as FDP in CSF showed the same values in both groups. An increase in CSF-FDP occurred after rebleeding and in patients with cerebral ischaemic symptoms. The results indicate that AMCA inhibits local fibrinolysis in CSF in patients with aneurysm rupture.

Fibrin-fibrinogen degradation products in cerebrospinal fluid.

An increase in low molecular weight fibrin-fibrinogen degradation products (FDP) was demonstrated in cerebrospinal fluid (CSF) from 17 of 18 patients with bacterial or viral meningitis compared with 29 patients without meningitis. The CSF also showed an increase in coagulation proteins of molecular weight less than 90000 (factors VII, IX, and plasminogen) but did not contain fibrinogen (MW 340000) or plasminogen activator. It is concluded that low molecular weight FDP in the CSF in infective meningitis result from leakage through a damaged blood-CSF barrier rather than from local digestion of fibrin deposited on the meninges.