Differentiation and function of osteoclasts cultured on bone and cartilage

We examined the differentiation and resorptive function of osteoclasts (OC) cultured on the slices of calcified bone, decalcified bone and hyaline cartilage, and found that OC differentiation depends on the co-cultured substratum, as well as osteoblast-derived factors. Bone marrow-derived macrophages (BMM) were formed from marrow cells of 5 week old ddY mice and cultured for 3 days on freeze-dried slices of calcified bone, decalcified bone or cartilage, all prepared from rabbit costal bone. BMM cultured on calcified bone slices exhibited tartrate-resistant acid phosphatase (TRAP) activity and were structurally characterized by multinucleation and ruffled border development. However, on decalcified bone slices, BMM seldom became multinucleated and exhibited weak TRAP activity. BMM cultured on cartilage slices were mononuclear, devoid of TRAP activity and structurally resembled mononuclear phagocytes. In SEM observations of co-cultured slices, resorption lacunae were formed only on calcified bone slices, and not on slices of decalcified bone and cartilage. Our results, therefore, indicated that BMM could differentiate into functional OC only on calcified bone slices, suggesting a key role of calcified components in the bone matrix for the terminal OC differentiation. Then, we cultured BMM on the same slices with yeast particles. In cultures with yeast particles, BMM exhibited intense TRAP activity, developed a ruffled border-like structure and formed resorption lacunae even on decalcified bone and cartilage slices. Vacuolar-type H+-ATPase was strongly expressed along the ruffled border membranes of these OC. Only the BMM that had not incorporated yeast particles developed a ruffled border, whereas the BMM that had incorporated yeast particles did not become multinucleated and lacked a ruffled border structure. Thus, our results further suggest that, even on uncalcified substrata, the terminal differentiation of BMM into functional OC is induced by an unidentified external stimulus, which may be contained in the cell membrane of yeast particles.     

Aberration measurement from specific photolithographic images: a different approach

Techniques for measurement of higher-order aberrations of a projection optical system in photolithographic exposure tools have been established. Even-type and odd-type aberrations are independently obtained from printed grating patterns on a wafer by three-beam interference under highly coherent illumination. Even-type aberrations, i.e., spherical aberration and astigmatism, are derived from the best focus positions of vertical, horizontal, and oblique grating patterns by an optical microscope. Odd-type aberrations, i.e., coma and three-foil, are obtained by detection of relative shifts of a fine grating pattern to a large pattern by an overlay inspection tool. Quantitative diagnosis of lens aberrations with a krypton fluoride (KrF) excimer laser scanner is demonstrated.     

Surface tension of molten silicon measured by the electromagnetic levitation method under microgravity

The surface tension of molten silicon was measured using the electromagnetic levitation method under microgravity. The atmosphere was Ar-3 pct H₂ purified by Pt asbestos and magnesium perchlorate. The partial oxygen pressure is estimated to be less than 1.1 × 10⁻¹⁴ Pa. The spherical droplet shape was controlled by changing the current ratio between a quadrupole coil and a dipole coil. The surface tension of molten silicon can be expressed by the equation

Stimulation of leukaemic cells from adult T-cell leukaemia patients with bacterial superantigens

Bacterial superantigens stimulate T cells in a manner that is restricted to the Vbeta of the T-cell receptor. We examined the ability of adult T-cell leukaemia (ATL) cells to respond to these superantigens. Mononuclear cells from 10 patients were cultured with staphylococcal enterotoxin A (SEA), staphylococcal enterotoxin B (SEB) or toxic shock syndrome toxin-1 (TSST-1), and their response was determined by MTT assay and 3H-thymidine incorporation assay. Cells from six patients showed a specific response to a single superantigen. In two cases the cells responded to TSST-1 and bore Vbeta2, the known target of TSST-1. In three cases the cells responded to SEA with one bearing Vbeta9, a target of SEA, and one bearing Vbeta16. In one case the cells responded to SEB. Most of the cells which proliferated in response to superantigens were determined genetically to be leukaemic. The response to TSST-1 was inhibited by anti-Vbeta2 antibody. The responding cells showed a strongly enhancement expression of interleukin-2 receptor. These findings indicate that leukaemic cells from a proportion of ATL patients have an ability to respond to T-cell receptor-dependent superantigens. This suggests that bacterial infection in such patients may contribute to the expansion of ATL cells.     

A Source for Multiply-Charged Ions and Acceleration of C, N and O Ions by IPCR Cyclotron

The design and performance of the ion source which is now used in the IPCR variable energy cyclotron are described. The source is of the electron-bombarded hot cathode type having two cylindrical cathodes of tungsten and a water-cooled copper anode containing a replaceable molybdenum slit plate. The arc discharge is established continuously but not pulsed. The source is usually operated very stably under an arc power of 1.5 to 3kW with a gas flow rate of 1 to 2 cc/min. The lifetime of the source is mainly limited by the erosion of the upper tungsten cathode at about 24 hours. At present, C4+, N4+, O4+, N5+ and O5+ ions are accelerated up to 48~100, 56~1100, 70~95, 56~125 and 70~125 MeV respectively, and a few micro-amperes of these ions are extracted from the cyclotron. The vacuum obtainable in the accelerating chamber is usually 2 ~ 4 × 10-6 mHg, and the loss of ion beam by the charge exchange effect is comparatively small. Extracted ion beams are used in several experiments for about 1900 hours in a year.     

InP/Al2O3n-channel inversion-mode m.i.s.f.e.t.s using sulphur-diffused source and drain

InP metal-insulator-semiconductor field-effect transistors (m.i.s.f.e.t.s) have been fabricated using c.v.d. Al2O3 as the gate insulator and the sulphur-diffusion process for source and drain. The n-channel inversion-mode device exhibits normally off behaviour. A maximum d.c. transconductance gm of 10 mS (87 mS/mm of gate width) has been obtained.     

n-channel formation on semi-insulating InP surface by m.i.s.f.e.t.

InP m.i.s.f.e.t.s using Fe-doped semi-insulating material surface have been fabricated. The devices, composed of sulphur-diffused n-type source and drain and c.v.d. Al2O3 gate insulator, exhibited n-channel normally-off behaviour and a source drain capacitance two orders of magnitude smaller than that of p-InP m.i.s.f.e.t.s with the same dimensions.     

Selectively ion implanted Gunn-f.e.t. integrated circuits for pulse regenerator

A planar GaAs integrated Gunn-effect device and f.e.t. connected in cascade have been fabricated using selective sulphur-ion implantation. High-speed pulse regeneration and pulse amplification have been realised under d.c. bias condition. Output voltage and voltage gain of the regenerated pulse of 1 ns width were 1.7 V and 18.6 dB, respectively.