Ryuji Tanaka

Analysis of peroxidase-negative acute unclassifiable leukemias by monoclonal antibodies. 1. Acute myelogenous leukemia and acute myelomonocytic leukemia

In this study, pretreatment peripheral and/or bone marrow blasts from 12 patients with acute unclassifiable leukemia (AUL) expressing the myeloid‐related cell‐surface antigen (CD 11) were isolated for further analysis. Despite a lack of myeloperoxidase (MPO) activity, 1 patients blasts contained cytoplasmic Auer rods. The circulating blasts from another patient expressed MPO while maintaining the same surface phenotype during 20 months of clinical follow‐up. In addition, the blasts from 3 cases demonstrated both myelomonocytic and monocyte‐specific surface antigens, whereas the remaining 9 cases completely lacked any monocyte‐specific antigen detectable by monoclonal antibodies, Mo2, My4 and Leu M3 (CD 14). The first case eventually was diagnosed as acute myelomonocytic leukemia and the second as acute myelogenous leukemia by means of immunophenotypic analysis using flow cytometry (FACS IV). In addition, the presence of MPO protein was identified in the cytoplasm of blast cells from 5 patients with AUL by means of a cytoplasmic immunofluorescence test using a monoclonal antibody (MA1). Our study indicates that non‐T, non‐B AUL expressing OKM1 (CD 11) antigens include acute leukemias which are unequivocally identifiable as being of either myeloid or myelomonocytic origin. However, further investigations, including immunophenotypic and cytoplasmic analysis, ultrastructural cytochemistry and gene analysis with molecular probes (tests applicable to normal myeloid cells), are necessary in order to determine the actual origin of blasts and to recognize the differentiation stages of the various types of leukemic cells from patients with undifferentiated forms of leukemia.

New Findings in Six-degrees-of-freedom Kinematics during Stationary Steppingin Patients with Knee Osteoarthritis

Background: Frontal plane knee kinematics are more likely associated with the development or progression of knee osteoarthritis. However, detailed frontal plane knee kinematics remain unclear. Previous studies examined movement during gait, squatting or stair stepping which allowed compensatory motion. However, biomechanical parameters in gait analyses can be modified. Therefore, we analyzed movement during stationary stepping activity while holding a handrail. The purpose was to determine: 1) detailed 6-degrees-of-freedom kinematics during stationary stepping activity in subjects with severe knee osteoarthritis; and 2) the association between unloading and black-loading phases. Methods: Twenty-four patients (32 knees) with severe medial knee osteoarthritis awaiting total knee arthroplasty were enrolled in this study. Knee kinematics was analyzed using a 3D-to-2D registration technique. Results: Knee adduction motion and tibial lateral translation increased from the unloading to weight-loading phase (P=0.027, P<0.001), but tibial internal-rotation motion was not increased (P=0.204). Knee adduction motion and tibial lateral translation motion were significantly correlated (r=0.400, P=0.023). Knee flexion angle during the weight-loading phase was negatively correlated with tibial lateral translation motion (r=0.597, P<0.001). Conclusions: A few studies that demonstrated detailed frontal plane knee kinematics have focused on the femoro-tibial motion. Severe knee osteoarthritis induced a greater knee adduction angle during the unloading phase, but the angle showed a smaller increase than that previously reported. Tibial lateral translation also increased during stationary stepping activity. Further work is needed to determine the association between femoro-tibial motion and varus thrust, and the association between knee flexion angle and intra-joint kinematics such as contact points. Level of Evidence: Cross-sectional study Level III