Inhibition of Fas antigen-mediated apoptosis of rheumatoid synovial cells in vitro by transforming growth factor beta 1

OBJECTIVE: To investigate the mitogenic and anti-apoptotic effects of transforming growth factor beta 1 (TGF beta 1) on rheumatoid synovial cells in vitro. METHODS: Synovial cells were cultured with or without TGF beta 1. After incubation, the proliferative response of synovial cells and the expression of Fas antigen and bcl-2 on synovial cells were examined. Finally, Fas antigen-mediated apoptosis of synovial cells was investigated by the addition of anti-Fas antibody. RESULTS: TGF beta 1 enhanced the proliferation of synovial cells in a dose-dependent manner. In addition, Fas antigen expression on synovial cells was inhibited by the addition of TGF beta 1 with up-regulation of bcl-2 expression. The addition of anti-Fas antibody induced synovial cell apoptosis. However, stimulation of synovial cells with TGF beta 1 became markedly resistant to Fas antigen-mediated apoptosis. The results were not affected by the addition of a neutralizing antibody to platelet-derived growth factor type AA (PDGF-AA), which suggests that the effect of TGF beta 1 on synovial cells was promoted via PDGF-AA-independent mechanisms. CONCLUSION: Our results suggest that TGF beta 1 promotes synovial cell proliferation through its mitogenic effect on synovial cells and interference with the apoptotic process mediated by the Fas antigen, resulting in the perpetuation of the synovial hyperplasia in patients with rheumatoid arthritis.     

Rate Effects on the Stress-Strain Behaviour of Eps Geofoam

The rate-dependency of the stress-strain behavior of EPS (Expanded Polystyrene) geofoam with densities of 19.3 and 28.0 kg/m³ was investigated by performing unconventional unconfined compression tests. A set of monotonic loading (ML) tests were performed at different constant values of vertical (axial) strain rate, ε_v. The ε_v value was stepwise changed many times and several sustained loading (SL) tests were performed during otherwise ML at a constant ε_v in other tests. A number of SL tests were performed during global unload and reload cycles to infer the stress-strain relation when ε_v=0. The elastic properties were evaluated by applying minute unload/reload cycles during otherwise ML. The rate-dependent stress-strain behaviour observed in these tests was described by an elasto-viscoplastic model (i.e., a non-linear three-component model), for which the vertical (axial) stress, σ_v, consists of inviscid and viscous components, σ_v^f and σ_v^v, while ε_v consists of elastic and irreversible components, ε_v^e and ε_v^ir. It is shown that the viscous property of EPS geofoam is of Isotach type in that, under the loading conditions where ε_v^ir is always positive, the current σ_v^v value is a unique function of instantaneous ε_v^ir and ε_v^ir, therefore the strength increases with ε_v. This viscous property was quantified based on the test results and incorporated into the model. The rate-dependent stress-strain behaviour, including the creep behaviour, observed in the experiment is simulated very well by the proposed model. In particular, the fact that the creep strain becomes significant when the sustained σ_v value becomes larger than the inviscid yield vertical stress is well simulated.     

Expression of p53 protein and p53 gene transcripts in rabbit carotid arteries after balloon denudation

A case of sinusitis caused by the basidiomycete Schizophyllum commune is reported in a 36-year-old female with a history of allergic rhinitis and dermatitis. The patient presented with sudden nasal obstruction, purulent nasal discharge, headache and general discomfort. Computer tomography revealed extensive opacity of the left maxillary sinus as well as erosion of the nasal wall and maxillary bone. Mycological examinations of nasal discharges and material aspirated during anthrostomy showed hyaline, septate hyphae with rare spicules. Primary isolation yielded a white, woolly mould which demonstrated clamp connections and basidiocarp primordia but these characteristics were lost in subculture. Identification was confirmed by vegetative compatibility studies. The patient was treated with itraconazole to avoid possible postsurgical dissemination. Three months after cessation of therapy, no recurrence of infection had occurred.     

Theoretical L-shell Coster-Kronig energies 11 ≤ Z ≤ 103

Relativistic relaxed-orbital calculations of L-shell Coster-Kronig transition energies have been performed ab initio for all possible transitions in atoms with atomic numbers 11 ≤ Z ≤ 103. Hartree-Fock-Slater wavefunctions served as zeroth-order eigenfunctions to compute the expectation of the total Hamiltonian. A first-order approximation to the local approximation was thus included. Quantum-electrodynamic corrections were made. Each transition energy was computed as the difference between results of separate self-consistent-field calculations for the initial, singly ionized state and the final two-hole state. The following quantities are listed: total transition energy, “electric” (Dirac-Hartree-Fock-Slater) contribution, magnetic and retardation contributions, and contributions due to vacuum polarization and self energy.     

Mapping of the pressure response element of the c-fos gene by direct DNA injection into beating hearts

In vivo gene transfer into various organs of postnatal animals has recently been demonstrated. We applied this technique in order to map the promoter element of the protooncogene c-fos in the myocardium that responds to left ventricular pressure overload in vivo. Beating rat hearts were directly injected with a recombinant plasmid containing a 356-base pair upstream regulatory element of the mouse c-fos gene fused to a reporter gene. Two days after the injection, the hearts were excised and buffer-perfused. Acute pressure overload was applied for 2 h by inflating an intraventricular balloon. Pressure overload increased the myocardial reporter gene activity by 3-8-fold (p < 0.01). Deletion and point mutations in the serum response element (SRE) of the c-fos promoter resulted in loss of pressure-induced reporter gene expression, indicating that the SRE is necessary for pressure response. The SRE alone was sufficient to confer pressure responsiveness to the minimal c-fos promoter, confirming that the pressure response element coincides with the SRE. A construct containing a point mutation at the p62TCF binding site of the SRE did not respond to pressure overload or to a protein kinase C activator but retained responsiveness to a calcium ionophore. This suggests that pressure overload may activate the c-fos promoter by a protein kinase C-dependent pathway. Thus, a directly injected gene can be regulated in the host cells by a physical stimulus to the intact organ. The in vivo DNA injection technique is a useful method to study complex organ physiology at the molecular level.     

Metallic Particle Motion in 3-Phase SF6 Gas Insulated Bus

To investigate the behavior of metallic particles in 3-phase gas insulated buses (3-phase GIB), we conducted a test by using a 3-phase 275kV, ac, 60Hz full-scale model. The test results revealed that in a 3-phase electric field, unlike in a single-phase field, metallic particles were trapped on and around the high-voltage conductors and revolved circumferentially. Computer analysis shows that it was closely related to locational and periodic changes in the electric field provided by the 3-phase GIB, and that there were points on the high-voltage conductors in which metallic particles were readily trapped. It also was proved that phenomena peculiar to the 3-phase GIB could be reproduced very well by computer simulation.