Interleukin 1 (IL-1) causes changes in lateral and rotational mobilities of IL-1 type I receptors

To investigate IL-1-dependent interactions of IL-1 type I (IL-1 RI) receptors on intact cells, lateral and rotational mobilities and detergent insolubility were investigated. Lateral mobility was measured by fluorescence photobleaching recovery, using a Cy3-modified, noncompetitive mAb specific for IL-1RI (M5) bound to wild-type IL-1 RI or mutant IL-1 RI with a truncated cytoplasmic tail. Addition of IL-1 causes significant reduction in the mobile fraction of wild-type IL-1 RI for two different transfected cell lines. For the mutant IL-1 RI, no significant decrease in response to IL-1 is observed, indicating that the missing cytoplasmic segment is involved in IL-1-dependent interactions of IL-1 RI that lead to reduced lateral mobility on the cell surface. The rotational mobility of IL-1 RI was assessed with phosphorescence anisotropy decay measurements using erythrosin-labeled M5. IL-1 decreases the rotational mobility of cell surface IL-1 RI on the microsecond time scale and also increases the initial anisotropy, indicating loss in segmental motion. Measurements of resistance to solubilization by Triton X-100 showed that IL-1 binding increases the fraction of IL-1 RI sedimenting with cytoskeletal residues. The IL-1 receptor antagonist protein (IL-1ra) causes partial effects in reducing rotational mobility and increasing detergent insolubility of M5-lableled IL-1 RI, indicating that this ligand causes structural changes in the presence of the dimerizing M5 mAb. These ligand-dependent physical interactions of IL-1 RI on the cell surface may be related to signal initiation by this receptor.     

Sasumata(U+I) shape skin incision for the surgery through median sternotomy

Since April, 1994 we have tried median sternotomy in a new skin incision which resembles to "Sasumata", a Japanese historical weapon of police, for the surgery of eleven patients with thymic disease or lung cancer for cosmetic reasons. An U-shaped skin incision in the upper half portion of the breast and a vertical incision from the bottom of "U" to xyphoid process were made. A comparison was made in eight patients with former conventional method, a linear incision on the sternum. The new incision was useful not only for cosmetic reasons but also for the following reasons; enough operation area, good lymph node dissection from lower neck to upper mediastinum without additional collar incision, and good healing of the skin. There were no differences between the two incision groups on operation time, bleeding volume and hospital stay after surgery. In a postoperative research almost all patients have been satisfied with the new incision.     

A further implementation of the rotational symmetry boundary conditions for calculations of P4(3)2(1)2 symmetry crystals

One of the most accurate styles of protein simulation is to calculate proteins in crystalline environment without neglect of long-range interactions. The long-range interactions can be accelerated by various methods. However, as a unit cell of a protein crystal is a large molecular assembly, its simulation is still unpractical without high-speed computers. Thus this article is addressed to the reduction of calculational volumes for protein crystal simulation by a further implementation of the rotational symmetry boundary condition method. For protein crystals in P4(3)2(1)2 symmetry, a computational cell and related tables were developed. A 120-ps molecular dynamics simulation was performed for a P4(3)2(1)2 symmetry crystal of glycogen phosphorylase b under rotational symmetry boundary conditions. The computational cell was one-eighth of the unit cell in volume, and less than about one-fourth of the conventional periodic boundary box. Generation of neighbor atom pair lists was greatly accelerated, and thus the simulation was practical even with a personal computer.