Fluorescent location of malignant cells in fine needle aspirates.

Malignant cells in fine needle aspirates possess a cell surface protease which can be targeted with fluorescent affinity probes. Cells with active GB exhibit cell surface fluorescence when stained with such affinity probes. The nuclei of all cells on the slides can be counterstained with a nuclear fluorescent stain. Malignant cells are then located by their cell surface fluorescence and their diagnosis confirmed by examining their fluorescent nuclei. Normal cells and benign cells exhibit no cell surface fluorescence and can be ignored. This technique can be used to rapidly select cells of cytological interest in FNA samples obtained routinely and might be adapted for automated screening of FNA.

Fine needle aspiration cytology of non-Hodgkin's lymphomas. A morphologic and immunophenotypic study.

To assess the value of fine needle aspiration cytology (FNAC) in the diagnosis of non-Hodgkin's lymphomas (NHL), we retrospectively studied all the cases diagnosed cytologically as NHL in our laboratory during a five-year period (1987-1991). We also traced cases in which FNAC failed to diagnose NHL and where the diagnosis was made subsequently by histopathology. Fine needle aspiration (FNA) was performed on both peripheral/palpable and deeply situated lesions. A total of 164 specimens were studied cytologically, and for 130 of them a histologic report was available. In 83 of the cases, FNA was carried out as part of the initial evaluation, and in 81 the diagnosis of NHL was known and FNA was performed to confirm or exclude a relapse. In 76 cases for which morphology was inconclusive the immunophenotype was assessed by immunocytochemistry. There were three false-negative and one false-positive result; in none of them was immunophenotyping performed. No discrepancy was observed in the distinction between low and high grade lymphomas, but this was feasible in only 115 of the 164 specimens studied. We conclude that the method is a feasible, rapid and inexpensive first approach in the evaluation of patients with NHL. FNAC may be substituted for histology in the occasional patient for whom the surgical risk outweighs the inaccuracies of the procedure.

Stimulation of human platelet aggregation by phospholipase-A and a saline "extract" of a polyurethane.

A saline extract of polyurethane (SPU) induces enzymatic conversion of arachidonic acid (either exogenous or released through the action of exogenous phospholipase-A) by activating a hitherto undiscovered labile enzyme, synthetase-alpha which is not blocked by aspirin. Addition of SPU, plus arachidonic acid or SPU plus phospholipase-A to platelet-rich plasma (PRP) triggers a biphasic platelet aggregation. Incubation of SPU with PRP results in activation and exhaustion of synthetase-alpha; this renders platelets refractory to the various aggregating agents.

2,3-diphosphoglycerate: a physiological inhibitor of platelet aggregation.

2,3-Diphosphoglycerate (2,3-DPG) may inhibit the platelet release reaction and the irreversible aggregation of human blood platelets induced by adenosine diphosphate, epinephrine, or norepinephrine. The effects of 2,3-DPG on platelet aggregation were more pronounced in cases with low hematocrit (less than 30 percent). Dipyridamole and vincaminor potentiated the antiaggregating effect of 2,3-DPG. Erythocytes (10-3 to 10-4 per microliter) exhibited a similar antiaggregating effect, especially when secured from anemic patients.