Sensitive diagnosis of cardiac allograft rejection by detection of cytokine transcription in situ

BACKGROUND & AIMS: Interleukin 12 (IL-12) is a heterodimeric, macrophage-derived cytokine that is elevated in Crohn's disease (CD). Epstein-Barr virus-induced gene 3 (EBI3) is a recently characterized human glycoprotein that is homologous to the 40-kilodalton chain of IL-12 and forms a heterodimer with the 35-kilodalton chain of IL-12. We investigated the expression of EBI3 in colonic mucosa of normal control subjects, patients with ulcerative colitis (UC), and patients with CD. METHODS: Colonic tissue was analyzed for messenger RNA (mRNA) expression by quantitative polymerase chain reaction and for protein expression by immunohistology and Western blotting. RESULTS: EBI3 mRNA was present in intestinal biopsy specimens from healthy subjects and patients with CD but was elevated only in active UC. EBI3 levels in UC specimens correlated with histological scores of activity and T-cell infiltration. EBI3-positive cells that had a shape consistent with that of macrophages were identified in the lamina propria, and protein was detected by Western blotting. CONCLUSIONS: EBI3 is a novel IL-12-related cytokine that is expressed by macrophage-like cells in normal intestine and CD and has enhanced expression in active UC but not in active CD.     

ZAP-70 association with T cell receptor zeta (TCRzeta): fluorescence imaging of dynamic changes upon cellular stimulation

The nonreceptor protein tyrosine kinase ZAP-70 is a critical enzyme required for successful T lymphocyte activation. After antigenic stimulation, ZAP-70 rapidly associates with T cell receptor (TCR) subunits. The kinetics of its translocation to the cell surface, the properties of its specific interaction with the TCRzeta chain expressed as a chimeric protein (TTzeta and Tzetazeta), and its mobility in different intracellular compartments were studied in individual live HeLa cells, using ZAP-70 and Tzetazeta fused to green fluorescent protein (ZAP-70 GFP and Tzetazeta-GFP, respectively). Time-lapse imaging using confocal microscopy indicated that the activation-induced redistribution of ZAP-70 to the plasma membrane, after a delayed onset, is of long duration. The presence of the TCRzeta chain is critical for the redistribution, which is enhanced when an active form of the protein tyrosine kinase Lck is coexpressed. Binding specificity to TTzeta was indicated using mutant ZAP-70 GFPs and a truncated zeta chimera. Photobleaching techniques revealed that ZAP-70 GFP has decreased mobility at the plasma membrane, in contrast to its rapid mobility in the cytosol and nucleus. Tzetazeta- GFP is relatively immobile, while peripherally located ZAP-70 in stimulated cells is less mobile than cytosolic ZAP-70 in unstimulated cells, a phenotype confirmed by determining the respective diffusion constants. Examination of the specific molecular association of signaling proteins using these approaches has provided new insights into the TCRzeta-ZAP-70 interaction and will be a powerful tool for continuing studies of lymphocyte activation.     

Comparison of biomechanical properties of the incisor periodontal ligament among different species

BACKGROUND: The aim of this study was to obtain a more precise understanding of the mechanical properties of the periodontal ligament in continuously erupting incisors by comparing the shear stress-strain relations among teeth from four closely related species. METHODS: Four species of experimental animals (mice, hamsters, rats, and rabbits) were used. Transverse sections of the left mandibular incisors were cut from the incisal, middle, and basal regions of each incisor. The tooth was pushed out of the alveolar bone in an extrusive direction at 5 mm/min using a materials testing machine. The maximum shear stress, maximum shear strain, tangent modulus, and failure strain energy density were estimated from the resulting stress-strain curve. Polarized light microscopic observations of collagen fibers were also made. RESULTS: All the biomechanical measures tended to decrease from the incisal toward the basal regions in all species. There were large species differences, especially in the incisal region, with the greatest maximum shear stress and failure strain energy density in hamsters. The greatest tangent modulus and the smallest maximum shear strain were observed in mice. The birefringent fiber architectures of the periodontal ligaments in the four species appeared to be similarly organized; the incisal periodontal ligament appeared to have more organized and thicker collagen fibres than did the middle and basal ligaments in the four species. CONCLUSIONS: These results suggest that the regional differences in the biomechanical properties of the periodontal ligament depend upon the developmental stages of the periodontal collagen fibers that may be related to the general arrangement, diameters, and densities of the collagen fiber bundles and the fiber insertions into the alveolar bone and cementum. The species differences in the biomechanical properties may be due to differences in the width of the periodontal ligament and the waviness as well as the strength and stiffness of the periodontal collagen fibers.     

Calcium ion as a second messenger for o-nitrophenylsulfenyl-adrenocorticotropin (NPS-ACTH) and ACTH in bovine adrenal steroidogenesis

o-Nitrophenyl sulfenyl-modified ACTH (NPS-ACTH) stimulated steroidogenesis acutely in bovine fasciculata-reticularis cells without increase in cellular cAMP synthesis. Application of NPS-ACTH to the cultured cells induced Ca2+ signals in individual cells as detected by video-enhanced microscopic fluorescence measurements. The percentage of Ca2+ signaling cells corresponded well with the increase of steroidogenesis induced by NPS-ACTH below 1 nM. Treatment of the cells with nicardipine, a Ca2+ channel blocker, suppressed the Ca2+ signals except for the transient increase just after the addition of NPS-ACTH and also blocked completely the stimulative effect on the steroidogenesis of NPS-ACTH below 1 nM. At a dosage of NPS-ACTH higher than 10 nM, the stimulative effect of steroidogenesis was partly suppressed by nicardipine and also by AA-861, a lipoxygenase inhibitor. The action of NPS-ACTH might be mediated by both Ca2+ and lipoxygenase metabolite(s) of arachidonic acid as dual second messengers. The effect of ACTH in pM range on the steroidogenesis was suppressed completely by the treatment with nicardipine and AA-861 at the same time, indicating that the action was mediated by both Ca2+ and the lipoxygenase metabolite(s) but not by cAMP. cAMP plays a significant role as a second messenger for ACTH action only at ACTH concentrations greater than 10 pM.     

A procedure to obtain a fully stressed shape of elastic continuum

In this paper, a procedure for obtaining a fully stresses shape of elastic continuum under arbitrary design conditions is proposed, by using the optimum distribution of the material properties such as the Young's modulus or the plate thickness. By using this technique, the optimum multiple-connected shape can be created from the original shape of simply body. The optimum shape of a road-pole subjected to an uniformly distributed load is determined by using the technique, and from the results the effectiveness of the technique is examined numerically.     

Experimental Facsimile Communication System on Packet Switched Data Network

The use of the public data network for facsimile communication has remarkable advantages with regard to high speed and reliable transmission and, in addition, it is well applicable to provide value added facilities for future service extension. The Research and Development Laboratories of Kokusai Denshin Denwa (KDD) Company, Ltd. have developed an experimental facsimile communication system on the packet switched data network (PSDN). The system is composed of packet switching exchanges (PSE), high speed digital facsimile terminal equipment, a facsimile communication processor (FCP), and facsimile packet assembly/ disassembly equipment (FAX-PAD). The facsimile equipment in the system adopts a two-dimensional modified READ code and has the interface protocol to the PSDN. The FCP provides the store-and-forward facilities to provide such services as delayed delivery, multiaddress delivery, and mailbox service. The FAX-PAD realizes the interworking between facsimile equipments on the public switched telephone network (PSTN) and those on PSDN. After various experiments including international field tests, it was confirmed that the system is useful for future advanced facsimile service.     

Defect levels in chromium-doped silicon

The transient capacitance technique has been used to study the chromium-related levels in the silicon band gap. Chromium was diffused at temperature of 1100 and 1150°C for 0.5 and 3 hr. Five different levels at E_c?0.11 eV, E_c?0.21 eV, E_c?0.28 eV, E_c?0.36 eV and E_c?0.45 eV were obtained from the Arrheniu plots of the electron thermal-emission rates. The number of levels in the upper half of the band gap decreased from five to two with an increase of Cr-diffusion period. Two levels were located at E_c?0.20 eV (donor) and E_c?0.43 eV (acceptor). A donor level was also observed at E_v + 0.25 eV. The donor level was not affected by the diffusion condition. The majority carrier capture cross sections of the three dominant levels have been measured by the transient capacitance technique modified by the pulse transformer. The values were σ_n = 4.1 × 10^?15 cm² for the upper donor at E_c?0.20 eV, σ_n = 2.0 × 10^?16 cm² for the acceptor at E_c ?0.43 eV and σ_p = 9.1 × 10^?18 cm² for the lower donor at E_v + 0.25 eV, and were independent of temperature. The three dominant levels are due to distinct chromium centers.     

Compensation of Interchannel Crosstalk Induced by Optical Fiber Nonlinearity in Carrier Phase-Locked WDM System

A scheme that compensates the waveform distortion induced by nonlinear interchannel crosstalk such as four-wave mixing (FWM) and cross-phase modulation as well as self-phase modulation in phase-locked wavelength-division-multiplexing transmission systems is proposed. Reduction of FWM-induced waveform distortion by controlling the phase relationship between neighbouring channels and its cancellation by precompensation is successfully demonstrated     

A Passive UHF RF Identification CMOS Tag IC Using Ferroelectric RAM in 0.35-μm Technology

A passive UHF RF identification (RFID) tag IC with embedded 2-KB ferroelectric RAM (FeRAM) for rewritable applications enables a 2.9 times faster read-and-write transaction time over EEPROM-based tag ICs. The resulting FeRAM-based tag has a nominally identical communication range for both read and write operations, which is indispensable for data write applications. The evaluated tag communication range with a folded dipole antenna is from 0 m to 4.3 m, at the 953-MHz carrier frequency with 4-W transmitting Effective Isotropic Radiated Power (EIRP) from a reader/writer. The developed tag IC features two circuit blocks to maximize the communication range in 0.35-mum CMOS/FeRAM technology. First is a CMOS-only full-wave rectifier, which can improve the measured efficiency by up to 36.6% by reducing the input parasitic capacitances and optimization of multiplier structure. This efficiency is more than twice that of previously-published results. Second is a low-voltage current-mode ASK demodulator to accommodate a low-breakdown voltage of FeRAM, which converts the ASK power modulation into a linearly modulated current over an incoming power range of 27 dB, corresponding to the entire communication range. The developed demodulator can thus resolve the primary design tradeoff issue between device protection and detection sensitivity in the conventional voltage-mode demodulator