Knee kinematics and kinetics during shuttle run cutting: comparison of the assessments performed with and without the point cluster technique

The differences between the assessments performed with and without the point cluster technique (PCT) for knee joint motions during the high-risk movements associated with non-contact anterior cruciate ligament (ACL) injuries have not been reported. This study aims to examine the differences between PCT and non-PCT assessments for knee joint angles and moments during shuttle run cutting. Fourteen high school athletes performed a maximal effort shuttle run cutting task. Motion data were collected by an 8-camera motion analysis system at 200 Hz, and ground reaction force data were recorded using a force plate at 1000 Hz. In both PCT and non-PCT approaches, the knee joint angles were calculated using Euler angle rotations, and the knee joint moments were obtained by solving the Newton-Euler equations using an inverse dynamics technique. For the extension/flexion angle, good agreement was measured between PCT and non-PCT assessments. The abduction angle obtained in the non-PCT assessment was smaller than that obtained with the PCT. An internal rotation angle was obtained in the PCT assessment, whereas a small external rotation angle was obtained in the non-PCT assessment. For the knee joint moments, good agreement between PCT and non-PCT assessments was observed for all the components. The differences in the knee joint angles were attributed in part to the differences in the position of the medial femoral epicondyle. The results suggest that the ACL injury risk during shuttle run cutting is estimated lower in the non-PCT assessment than in the PCT assessment.     

Different recognition of transgenic HLA-DQw6 molecules by mouse CD4+ and CD8+ T cells

Address correspondence and offprint requests to: T. Sasazuki.     

Streptococcal immunoglobulin-binding protein Sib35 exerts stimulatory and mitogenic effects toward mouse B lymphocytes

Group A Streptococcus (GAS) produces several immunopotent proteins such as the immunoglobulin-binding protein 35 (Sib35) family, known to be an immunoglobulin G-degrading enzyme of GAS and a CD16-binding protein of GAS, Mac-1-like protein/IdeS. In this study, Sib35 activated mouse B cells and induced the proliferation of B lymphocytes, while it also bound directly to B cells, which enhanced the expression of MHC class II and B7-2. Furthermore, Sib35 induced the differentiation of B cells to immunoglobulin-producing plasma cells and B cell line proliferation. These results suggest that Sib35 functions as a streptococcal mitogen of mouse B cells.     

Nondestructive tree-ring measurements for Japanese oak and Japanese beech using micro-focus X-ray computed tomography

The purpose of this study is to establish technology for utilizing images taken by micro-focus X-ray computed tomography (CT) to perform nondestructive tree-ring measurement of wooden cultural properties. This paper covers two experiments conducted using Japanese oak as a typical example of ring-porous wood and Japanese beech as a representative example of diffuse-porous wood. In the first experiment, images of thin strip specimens of Japanese oak and Japanese beech taken by micro-focus X-ray CT are compared against those taken by soft X-ray radiography, the method conventionally used in dendrodensitometry. A discussion then follows in regard to image quality and tree-ring width measurement resulting from the two methods. In the second experiment, tomograms are taken of folk art articles made of Japanese oak and Japanese beech, demonstrating that it is possible to use nondestructive means to visualize the tree-rings of three-dimensional objects. The results show that micro-focus X-ray CT offers much promise of widespread utilization in the tree-ring dating of wooden cultural properties.     

Calmodulin and cell proliferation

The calmodulin content of synchronized Chinese hamster ovary (CHO-K₁) cells was determined at each phase of the cell cycle. The calmodulin content was minimum in the G₁ phase, increased after the cells entered S phase and reached the maximum level at the late G₂ or early M phase. When 30 μM of W-7 (calmodulin antagonist) was added at the S phase, the cell cycle was blocked at the late G₂ or early M phase. The addition of W-7 also prevented the morphological changes caused by cholera toxin. These results suggest that calmodulin plays an important role in the phases through S to M, possibly in the initiation of DNA synthesis and in the mitosis.