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Notes: Porphyromonas gingivalis has been shown to attack host defense systems through proteolytic cleavage of a wide variety of members of the systems. In this study, we examined the ability of P. gingivalis culture supernatant to alter the expression of human T cell surface proteins. As judged by flow cytometric analysis, detection of CD4 expression was completely eliminated by the supernatant, but CD8 was less sensitive. When the culture supernatant was added with reducing agents, proteolytic activity was enhanced, resulting in the cleavage of CD8. Mitogenic response of T cells to phytohemagglutinin or concanavalin A was decreased by the treatment of the cells with the culture supernatant of P. gingivalis. The three forms of gingipains (high molecular mass arginine-specific gingipain, arginine-specific gingipain 2 and lysine-specific gingipain) purified from the culture supernatant of P. gingivalis actively cleaved CD4 and CD8 on human T cells, indicating that proteolytic activity of the culture supernatant was due to gingipains. These results suggest that cysteine proteinases like gingipains released from P. gingivalis cleave T cell surface proteins and impede T cell function.

Notes: Background: The IgA1 molecule, which is predominantly deposited in glomeruli of IgA nephropathy, has the characteristic O-glycan side chain in its hinge region. Several lines of evidence have demonstrated that underglycosylated IgA1 acquires self-aggregation1 and binding affinities to the extra-cellular matrix,1,2 resulting in deposition in the glomeruli.3,4 However, there is little information concerning actual biological activities of the underglycosylated IgA1 deposited in glomeruli, which lead to mesangial cell proliferation and/or matrix expansion.Aim: To clarify the influence of O-glycan side chain in the hinge of IgA1 on its biological activity in mesangial cells, we performed a comprehensive gene expression profiling analysis of human cultured mesangial cells stimulated by enzymatically underglycosylated IgA1 using cDNA array.Methods: IgA1 was purified by affinity chromatography using anti IgA column followed by Jacalin column. Asialo/agalacto IgA1 was obtained by enzyme digestion using sialidase and β-galactosidase. Heat aggregated IgA1 was obtained by incubation at 63°C for 150 min. Cultured human mesangial cells were stimulated for 3 h by non-treated IgA1, heat aggregated IgA1 or asialo/agalacto IgA1, respectively, and total RNA was obtained. Only the enzyme stimulation was performed as a negative control for asialo/agalacto IgA1. After DNase treatment, isotope labelled probes were prepared by reverse transcription and hybridized to the Atlas Human 1.2 Array (CLONTECH, Palo Alto, CA, USA) according to the manufacturer’s protocol. A total of 1176 arrayed genes were quantitatively evaluated using BAS.Results: Expression profiles of 1176 genes were obtained. In all experiments, none of the three negative controls on the cDNA array was detected. The expression profiles of mesangial cells by each IgA1 stimulation resembled one another, but they were widely different from that of mononuclear cells. On the whole, 10% of the genes expressed in the mesangial cells were up-regulated by asialo/agalacto IgA1 stimulation compared to that by enzyme stimulation. The results suggested that under-O-glycosylated IgA1 has a biological function in human mesangial cells in vitro. In good agreement with previous studies,5 heat aggregated IgA1 stimulation up-regulated IL-6 and TNF-α expressions in mesangial cells compared to by non-treated IgA1. Asialo/agalacto IgA1 stimulation also up-regulated these molecules, suggesting its pathogenetic role in IgA nephropathy. However, since a similar tendency was revealed by enzyme stimulation alone, further study may be necessary to establish these observations.Conclusion. In the present study, we investigated the comprehensive expression profiles of mesangial cells stimulated by various types of IgA1 using cDNA array. This approach may serve as a useful database not only to evaluate the biological activities of under-O-glycosylated IgA1 but also to elucidate the pathogenesis of IgA nephropathy.

Notes: Abstract The excitation conditions where both direct Coulomb and shake-off processes concur to multiply ionize fluorineK andL shells were adopted in this experiment; 6MeV/amu p,α and C4+ impacts. The ion induced FKα satellites, measured for a series of F bearing compounds, showed significant chemical effects on their intensity distributions. Such effects are explained well with an FL-vacancy rearrangement model. Without any theoretical prediction, rearrangement probabilities or widths of FL shells were estimated by use of a reference compound with high ionicity, i.e. NaF. A linear relationship between FL widths and covalencies of compounds was found for a wide variety of fluorides. For the same compounds, the absolute values of the FL-vacancy rearrangement probabilities or the FL-shell widths obtained here were the same as those estimated from pure direct Coulomb and pure shake-off excitations, respectively. Other models than theL-vacancy rearrangement's are also discussed and eliminated.

Notes: Abstract Continuous observation of dislocation motion on the specimen surface of IIb–VIb semiconducting compounds (CdS and CdTe) has been made using a scanning electron microscope (SEM) with the cathodoluminescence (CL) by use of a deformation apparatus installed in the SEM chamber. With the application of stress, SEM-CL patterns revealed an increasing density of dark spots that formed dark stripes along slip traces. For both CdS and CdTe crystals, regardless of the slip system involved, the dark spots corresponding to individual dislocations appeared in the SEM field without displaying their moving state and seldom disappeared, indicating that dislocations are immobilized after they travel a certain distance from the source with a high velocity. The investigation of slip-band growth in CdS showed that screw bands on the basal plane exhibit the photoplastic effect, whereas those on the prismatic plane do not, in accordance with the macroscopic deformation tests.