Recent data suggest that mast cells (MCs) and their products are involved in the pathophysiology of thrombosis. In the present study, we analyzed the number, distribution, and phenotype of prostate MCs and periprostatic MCs in patients with unilateral periprostatic vein thrombosis (PVT) by immunohistochemical analysis and electron microscopy. MCs reacted with monoclonal antibodies to tryptase, chymase, and c-kit/CD117 and stained positively for tissue-type plasminogen activator (tPA) and urokinase receptor (uPAR/CD87) but did not express detectable urokinase (uPA) or plasminogen activator inhibitors (PAI-1, PAI-2). We found an increase in the mean +/- SEM number of MCs in PVT compared with control (PVT, 14.36 +/- 1.57 vs control, 5.23 +/- 0.57/mm2). The majority of MCs accumulated in the adventitia of thrombosed veins and showed a decrease in chymase expression. As MCs increase in number in PVT and express a profibrinolytic phenotype, we hypothesize that MC-derived molecules have a role in endogenous fibrinolysis.

We investigated the degradation of angiotensin I (Ang I) by guinea pig aqueous humor at physiological pH (pH 7.4) and assessed the activity of responsible enzymes using various enzyme inhibitors. The aqueous humor was incubated with Ang I in the presence or absence of an enzyme inhibitor at 37 degrees C for the appropriate time period. The resulting peptides were analyzed by a Beckman HPLC system with a Waters microBondapak C18 analytical column using a 30-min increasing linear gradient of 10 to 40% acetonitrile containing 0.05% trifluoroacetic acid (TFA) and H2O containing 0.05% TFA at a flow rate of 1 mL/min. Detection was done by absorbance at 214 nm. Angiotensin II (Ang II) was a major product (39.3+/-4.10 nmol x h(-1) mL(-1), n = 5) of Ang I hydrolysis. Traces of angiotensin 1-9, angiotensin IV, and angiotensin 1-7 were also produced. Chymostatin (0.05 mmol/L), EDTA (1 mmol/L), enalaprilat (0.1 mmol/L), and ebelacton B (0.01 mmol/L) inhibited generation of Ang II from Ang I by guinea pig aqueous humor by 89+/-4.6, 56+/-7.6, 33+/-5.1, 20+/-6.5%, respectively. Our findings indicate that guinea pig aqueous humor contains several enzymes that can form Ang II. The chymostatin-sensitive type of enzyme was the most active one found in guinea pig aqueous humor. Angiotensin I converting enzyme, carboxypeptidase A, and deamidase may also contribute to angiotensin II formation in guinea pig ocular fluid.

The protonation and complex formation equilibria in aluminium(III) + ofloxacin (Hoflo) solutions in the presence of either cetyltrimethylammonium bromide (CTAB, 5.0 mmol L−1), cetylpyridinium chloride (CPCL, 2.0 mmol L−1) or polyethylene glycol tert-octylphenyl ether (triton X-100, 1.0 mmol L−1) have been studied by glass-electrode potentiometric measurements in a 0.1 mol L−1 LiCl ionic medium at 298 K. In the concentration range 0.4 ≤ CAl ≤ 1.0 mmol L−1, with a ligand to metal ratio of 1 : 1 to 5 : 1, and 3.5 ≤ −log h ≤ 7.0, a non-linear least squares treatment of the data indicate that in all studied systems the complex Al(oflo)2+ forms as the dominating one. Its overall stability constant (log β) is in the range 10.37–11.90 (depending on the type of surfactant), which is about 1 log unit higher than in the absence of surfactants. The formation of bis(ofloxacinato) and mixed protonated or hydrolytic complexes is largely suppressed in the presence of surfactants. The adsorption of ofloxacin on aluminium ...

The signaling mechanisms downstream of growth factor-stimulated proliferation in myeloid leukemia cells have not yet been fully elucidated. Recent evidence suggests that alternate pathways to the mitogen-activated protein kinase cascade are required. We have previously shown that Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) activates cytosolic phospholipase A2 (cPLA2), which is involved in the proliferation of vascular smooth muscle cells. In the present study, the contribution of this pathway was investigated in the proliferation of U-937 myeloid leukemia cells. In U-937 cells, fetal bovine serum (FBS)-induced proliferation was attenuated by CaM kinase II inhibitor KN-93 but not by its inactive analog KN-92. Inhibitors of cPLA2 (methyl arachidonyl fluorophosphonate and arachidonyl trifluoromethyl ketone) also reduced proliferation of U-937 cells. FBS-induced proliferation was also attenuated by cotransfection with cPLA2 antisense oligonucleotides. These results suggest a role for CaM kinase II and cPLA2 in the proliferation of U-937 cells. FBS stimulated CaM kinase II and cPLA2 activities in a time-dependent manner. Moreover, FBS-stimulated phosphorylation and activation of cPLA2 activation was inhibited by KN-93. FBS-stimulated phosphorylation of CaM kinase II was blocked by KN-93 but not by cPLA2 inhibitors, suggesting that CaM kinase II activates cPLA2. The products of phospholipid hydrolysis produced by cPLA2, lysophosphatidylcholine but not arachidonic acid, increased [3H]thymidine incorporation in U-937 cells. These data suggest that exposure of U-937 cells to FBS promotes phosphorylation and activation of CaM kinase II, leading to stimulation of cPLA2 and generation of lysophosphatidylcholine and resultant proliferation of these cells.

BACKGROUND Cardiomyopathy and low ejection fraction (EF) are associated with cardiac thrombi and cardiogenic embolism but may also be risk factors for hypoperfusion-related cerebral ischemia (HRCI). Current stroke subtype criteria do not include an HRCI category. METHOD To look for evidence of HRCI, we compared mean infarct volume between serial patients with EF < or =35% and high-grade (> or = 70%) carotid stenosis and serial patients with normal EF and high-grade carotid stenosis. We matched serial stroke patients with EF < or =35% with stroke patients with normal EF and compared the number and type of ischemic lesion (symptomatic or asymptomatic) and mean infarct volume on magnetic resonance imaging. We blindly compared stroke subtype in these groups using modified Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria, including an HRCI category. RESULTS In patients with carotid stenosis, ipsilateral infarct volume was greater with EF < or = 35% (74.7 mL, 95% CI, 17.3-132.1 mL) than in controls (17.1 mL, 95% Cl, 9.4-24.8 mL) (P<.05). There was no difference in the mean number of HRCI-compatible infarcts on computed tomography scan between patients with low EF and controls. Symptomatic HRCI occurred in 4 of 15 patients with low EF and in 0 of 15 controls. CONCLUSIONS Symptomatic HRCI occurs in patients with low EF. Severe arterial stenosis may interact with left ventricular systolic dysfunction to cause cerebral hypoperfusion. Modification of the TOAST criteria to include an HRCI subtype is feasible and HRCI should be included as a stroke subtype.