Flow cytometric determination of intracytoplasmic Wiskott-Aldrich syndrome protein in peripheral blood lymphocyte subpopulations.

We have produced a novel monoclonal antibody (mAb) directed against Wiskott-Aldrich syndrome protein (WASP) by immunizing mice with the recombinant protein. The mAb designated 5A5 is highly specific to WASP and suitable for Western blot analysis and immunoprecipitation. A flow cytometric assay using the 5A5 mAb identifies expression of intracytoplasmic WASP in lymphocytes from normal individuals. Double staining analysis with cell surface CD3, CD19, and CD56, and intracytoplasmic molecules revealed WASP expression in each subpopulation. With regard to WASP expression in patients with Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT), peripheral blood mononuclear cells (PBMCs) from nine patients and Epstein-Barr virus-transformed B-lymphoblastoid cell lines from seven patients examined did not show WASP expression by flow cytometric analysis. These results were confirmed by Western blot analysis. We conclude that WASP expression in lymphocyte subpopulations from patients with WAS and XLT can be more precisely evaluated by flow cytometry as compared with Western blot analysis. This flow cytometry method is important as a supplement to Western blots, but even more important as an alternative and powerful assay that can contribute to research on WASP as well as diagnosis in a clinical setting.

Effects of the aminopeptidase P inhibitor apstatin on bradykinin-induced inositol 1,4,5-triphosphate in neonatal rat cardiomyocytes.

We investigated the effect of apstatin (an aminopeptidase P inhibitor) on bradykinin-induced inositol 1,4,5-triphosphate (IP3) formation and glucose uptake in isolated neonatal rat cardiomyocytes. Apstatin enhanced bradykinin-induced IP3 formation in a dose-dependent manner. We found that 1 microM Hoe 140 (a bradykinin B2-receptor antagonist) significantly decreased the potentiation of bradykinin-induced IP3 production by 5 microM apstatin from 781.8+/-67.2 to 127.4+/-33.0 pmol/mg protein; 5 microM apstatin increased bradykinin-induced glucose uptake from 197.0+/-25.5 to 297.3+/-64.0 pmol/h per milligram of protein. The stimulation of glucose uptake with apstatin was blocked to 132.5+/-26.2 pmol/h per milligram of protein by 1 microM Hoe 140. We conclude that apstatin stimulates bradykinin-induced IP3 formation and glucose uptake by preventing the degradation of bradykinin.

ONO-5046, an elastase inhibitor, attenuates liver mitochondrial dysfunction after endotoxin.

OBJECTIVE: To investigate the effect of ONO-5046, an elastase inhibitor, on liver mitochondrial dysfunction after endotoxin administration. DESIGN: Prospective, randomized, controlled animal study. SETTING: Research laboratory. SUBJECTS: Male Hartley guinea pigs. INTERVENTIONS: Endotoxin shock was induced by intravenous infusion of Escherichia coli lipopolysaccharide endotoxin (50 mg/kg). Six guinea pigs were treated with endotoxin and saline. Twenty-four guinea pigs received 5, 10, and 30 mg/kg/hr of ONO-5046 after endotoxin administration. Six guinea pigs received only saline. MEASUREMENTS AND MAIN RESULTS: We measured oxygen uptake in state 3 (substrate and adenosine 5'-diphosphate [ADP]) and state 4 (excess substrate, no ADP), as well as the respiratory control ratio (state 3/state 4), adenosine 5'-diphosphate/oxygen ratio (ADP/O), and arterial ketone body ratio. ONO-5046 was dose dependently effective in liver mitochondrial oxidative phosphorylation, such as oxygen uptake in stage 4, respiratory control ratio, adenosine triphosphate synthesis, ADP/O, and arterial ketone body ratio when ONO-5046 was started 30 mins after endotoxin. The administration of 30 mg/kg/hr of ONO-5046 improved mean blood pressure, which had decreased after endotoxin. CONCLUSION: ONO-5046 attenuates the endotoxin-induced liver mitochondrial dysfunctions that may be related to increased liver blood flow.

[Investigation of a new method for separation of neutrophils from a small volume of human blood].

We have already reported a neutrophil separation method for the multiple simultaneous measurement of neutrophil chemiluminescence. However, when the reported separation method was used, at least 4 ml of venous blood was needed to collect enough neutrophils for chemiluminescent measurement. Because of this blood volume, there is a limitation on applications of the multiple simultaneous method for neonates, infants, and in some clinical situations. To expand the application of this neutrophil chemiluminescence measurement into clinical and health science areas, we have developed a new method for separation of neutrophils from a relatively small amount of blood (500 microliters). In addition, the influences of remaining red blood cells and hemoglobin levels in the neutrophil fraction on the chemiluminescence were examined to determine the necessity for elimination procedures. The new separation method used a capillary tube (length, 130 mm; outside diameter, 5 mm; thickness, 0.8 mm) with density gradient reagents (Histopaque 1077 and 1119). After centrifugal separation (500 g, 30 min), the neutrophil fraction was isolated with 93.1 +/- 4.7% purity and 60.6 +/- 11.1% yield. This purity and yield were comparable to or better than those with the previously reported method, while levels of remaining red blood cells and hemoglobin were about the same. Remaining red blood cells and hemoglobin in the neutrophil fraction acted on the chemiluminescence as a quencher. For the correct estimation of neutrophil chemiluminescence, elimination of remaining red blood cells and hemoglobin in the neutrophil fraction is necessary. This new neutrophil separation method is a very useful method, especially for cases in which available blood amounts are limited.