In vitro ethylene-diamine-tetra-acetic acid (EDTA) dependent satellitism and phagocytosis of platelets by neutrophils have been considered to be rare phenomena. It is associated with pseudothrombocytopenia, abnormal histogram of platelets and pseudoleukocytosis on complete blood cell count (CBC) by automated blood cell counter, but these findings are not found in heparinized or sodium citrated blood. It has no clinical significance such as bleeding tendency or abnormal platelet function. EDTA dependent platelet satellitosis and phagocytosis must be differentiated from true thrombocytopenia. We report a case of EDTA dependent platelet phagocytosis by neutrophils in a 68 year-old male patient who was diagnosed as mycosis fungoides. His EDTA blood smear showed frequent phagocytosis of platelets by neutrophils and occasional platelet satellitism. The bood cell counts were within normal limits without pseudothrombocytopenia. Phagocytized platelets were confirmed by immunohistochemistry using GpIIb/IIIa antibody and transmission electron micrographs.
Aged ; Blood Cell Count ; Blood Platelets* ; Cell Count ; Edetic Acid* ; Hemorrhage ; Heparin ; Humans ; Immunohistochemistry ; Male ; Mycosis Fungoides* ; Neutrophils* ; Phagocytosis* ; Sodium ; Thrombocytopenia

Chronic exposure to cadmium (Cd) results in an inhibition of protein endocytosis in the renal proximal tubule, leading to proteinuria. In order to gain insight into the mechanism by which Cd impairs the protein endocytosis, we investigated the effect of Cd on the acidification of renal cortical endocytotic vesicles (endosomes). The endosomal acidification was assessed by measuring the pH gradient-dependent fluorescence change, using acridine orange or FITC-dextran as a probe. In renal endosomes isolated from Cd-intoxicated rats, the Vmax of ATP-driven fluorescence quenching (H -ATPase dependent intravesicular acidification) was significantly attenuated with no substantial changes in the apparent Km, indicating that the capacity of acidification was reduced. When endosomes from normal animals were directly exposed to free Cd in vitro, the Vmax was slightly reduced, whereas the Km was markedly increased, implying that the biochemical property of the H -ATPase was altered by Cd. In endosomes exposed to free Cd in vitro, the rate of dissipation of the transmembrane pH gradient after H -ATPase inhibition appeared to be significantly faster compared to that in normal endosomes, indicating that the H -conductance of the membrane was increased by Cd. These results suggest that in long-term Cd-exposed animals, free Cd ions liberated in the proximal tubular cytoplasm by lysosomal degradation of cadmium-metallothionein complex (CdMT) may impair endosomal acidification 1) by reducing the H -ATPase density in the endosomal membrane, 2) by suppressing the intrinsic H -ATPase activity, and 3) possibly by increasing the membrane conductance to H+ ion. Such effects of Cd could be responsible for the alterations of proximal tubular endocytotic activities, protein reabsorption and various transporter distributions observed in Cd-exposed cells and animals.
Acridine Orange ; Animals ; Cadmium* ; Cytoplasm ; Endocytosis ; Endosomes ; Fluorescence ; Hydrogen-Ion Concentration ; Ions ; Kidney ; Membranes ; Proteinuria ; Proton-Motive Force ; Rats

Patients with acute myelocytic leukemia (AML) have varied outlooks for survival after the diagnosis. To identify pretreatment prognostic indicators in AML, we analyzed 132 cases of AML seen at our hospital between June, 1989 and December, 1994. The median age of the patients was 40 years (range, 15-81). There were 63 male and 69 female patients. One hundred eight patients (82%) received induction chemotherapy which was based on cytarabine plus anthracyclines. Sixty six patients achieved complete remission (CR) and the CR rate among the patients given induction chemotherapy was 61%. The median duration of CR was 11.2 months. After median follow up of 6.6 months (range 0.5-51.4), 26 patients (39%) remain in continuous CR. The median duration of overall survival of the patients was 6.7 months. After median follow up of 10.6 months (range, 0.1-52.7), 41 patients (31%) are alive. Variables affecting duration of CR included the age of the patients, performance status of the patients, percentage of blast in the peripheral blood, hemoglobin level, percentage of blast in the bone marrow, FAB subtype, and CD7 marker positivity. Variables affecting survival duration included age of the patients, performance status of the patients, absolute blast count (ABC) in the peripheral blood, bone marrow cellularity, the percentage of blast in the bone marrow, and CD5 marker positivity. Multivariate analysis showed that the age of the patients and percentage of blast in the bone marrow were significant independent indicators for overall survival of the patients. Further studies utilizing cytogenetics and molecular characteristics of leukemic cell are warranted to better define the prognostic factors of patients with AML.
Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Female ; Human ; Leukemia, Myelocytic, Acute/*mortality ; Male ; Middle Age ; Multivariate Analysis ; Prognosis ; Survival Rate