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Despite the extensive use of Sn-Ag-Cu as a Pb-free solder alloy, its melting point is significantly higher than that of eutectic Sn-Pb solder. Sn-Ag-Bi-In solder is an alternative Pb-free solder, with a melting temperature close to that of eutectic Sn-Pb. This study elucidates the electromigration behavior of Sn-Ag-Bi-In solder and then compares the results with those of the Sn-Ag-Bi system. The behavior of Pb-free Sn-Ag-Bi-In solder strips under electromigration is examined by preparing them in Si (001) U-grooves. The samples are then tested under various temperatures and current densities. Although the compounds thicken near both electrodes with current stressing, the thickness at the anode exceeds that at the cathode. Experimental results of the average failure time indicate that Sn-Ag-Bi-In solder has a longer lifetime than does Sn-Ag-Bi, which is attributed to the ζ phase. Additionally, the ζ phase dissolved by the current in the early stage replenishes the outgoing atomic flux. These atomic fluxes also enhance the growth of abnormally large particles in the middle of the strips. Field-emission electron probe microanalysis (FE-EPMA) results indicate that the amount of indium is reduced after the ζ phase near the cathode is exhausted for extended current stressing time. [ABSTRACT FROM AUTHOR]

SUMMARY To determine the biological functions of membrane expressed CD45 isoforms on polymorphonuclear neutrophils (PMN), the monoclonal IgG F(ab′)2 antibody against CD45, CD45RA or CD45RO was used as surrogate ligand for binding with these molecules on PMN. We found 99·5 ± 3·2%, 42·3 ± 5·8% and 96·7 ± 2·6% PMN expressed CD45, CD45RA and CD45RO molecules on the cell surface, respectively. The interaction of CD45, CD45RA or CD45RO with its specific antibody on PMN enhanced phagocytosis markedly (34–83% increase), mainly via increased expression of complement receptor type 3 (CR3, CD11b) on the cells. The production of IL-8 by PMN was also increased significantly after binding with antibodies (anti-CD45 > anti-CD45RO > anti-CD45RA). Anti-CD45RA and anti-CD45RO, but not anti-CD45, enhanced TNF-α mRNA expression and decreased protein tyrosine phosphorylation of PMN. However, only anti-CD45RO suppressed Src family protein tyrosine kinase p56lck expression in the cells. These results suggest that the cross-linking of CD45 isoforms by their specific antibodies stimulated different PMN activities by differential suppression on protein tyrosine phosphorylation and Src family tyrosine kinase p56lck . [ABSTRACT FROM AUTHOR]

Affinity-purified human polyclonal anti-double-stranded DNA antibodies (anti-dsDNA) exerted a cytostatic effect towards human and rat glomerular mesangial cells (MC). In order to identify the cognate antigens for anti-dsDNA on the surface of MC, we used these autoantibodies to probe a human renal λg11 cDNA expression library. Two cDNA clones encoding the cognate proteins for the autoantibodies were isolated. Sequencing analysis of the two cDNA showed that they had 98.6% homology with the gene of the P0 and 99.2% homology with the gene of the Pi human acidic ribosomal phosphoproteins (P protein). Two galactosidase fusion proteins (125 000 and 150 000 MW) derived from the two cDNA inserts expressed in lysogenic Escherichia coli Y1089 could react with the original screening antibodies in an immunoblotting analysis. After transformation and expression of the full-length P1 clone in prokaryotic cells, the purified P1 protein was able to react with anti-dsDNA. In a cross-inhibition experiment, the dsDNA binding activity of anti-dsDNA was inhibited by a synthetic polypeptide corresponding to the carboxyl terminal 20 amino acids of P protein and purified P1 protein in a dose-dependent manner, but this was less potent than the inhibition caused by calf thymus dsDNA. By use of well-defined systemic lupus erythematosus (SLE) sera, we found only sera containing a high titre of anti-dsDNA activity (>300 IU/ml) reacted with P1 of rat MC lysate. Furthermore, the 38000 and 19000 MW macromolecules were proved to be the cognate antigens for anti-dsDNA expression on the surface of the MC, by Western blot of the MC plasma membrane lysates. These results suggest that antidsDNA may cross-react with ribosomal P proteins expressed on the surface of the MC and exert cytostasis towards these cells. [ABSTRACT FROM AUTHOR]

Objectives: Initiation and maintenance of pro-inflammatory reactions elicited by bacterial lipopolysaccharide and/or cytokines in the macrophage lineage have been reported to play a crucial role in acute and chronic pathogenic effects. Whether pro-inflammatory responses triggered by lipopolysaccharide in growth arrested cells differ from those in proliferating cells remains unanswered., Materials and Methods: Olomoucine and roscovitine are cyclin-dependent kinase (CDK) inhibitors that prevent progression through the cell cycle. After treatment with CDK inhibitors, expression of pro-inflammatory genes was analysed by reverse transcriptase-polymerase chain reaction. Protein levels of inducible nitric oxide synthase (iNOS) and nuclear factor kappaB (NF-kappaB) were determined by Western blotting. Promoter activity of iNOS was measured by the luciferase activity assay., Results: In this study we have demonstrated that both olomoucine and roscovitine inhibit cell proliferation and diminish nitric oxide production and cytokine gene expression, in lipopolysaccharide-stimulated murine RAW264.7 macrophages. In addition, olomoucine reduces iNOS promoter activity and alleviates NF-kappaB transcription activation. After co-transfection with E2F1 interference RNA, suppression of lipopolysaccharide-mediated iNOS promoter activity and NF-kappaB activation was observed. Furthermore, we demonstrated that olomoucine-induced growth arrested cells reduce expression of the p65 subunit of NF-kappaB., Conclusions: The findings of this study suggest that inhibition of cell-cycle progression is capable of reducing pro-inflammatory responses via down-regulation of NF-kappaB.

To determine the biological functions of membrane expressed CD45 isoforms on polymorphonuclear neutrophils (PMN), the monoclonal IgG F(ab')2 antibody against CD45, CD45RA or CD45RO was used as surrogate ligand for binding with these molecules on PMN. We found 99.5 +/- 3.2%, 42.3 +/- 5.8% and 96.7 +/- 2.6% PMN expressed CD45, CD45RA and CD45RO molecules on the cell surface, respectively. The interaction of CD45, CD45RA or CD45RO with its specific antibody on PMN enhanced phagocytosis markedly (34-83% increase), mainly via increased expression of complement receptor type 3 (CR3, CD11b) on the cells. The production of IL-8 by PMN was also increased significantly after binding with antibodies (anti-CD45 > anti-CD45RO > anti-CD45RA). Anti-CD45RA and anti-CD45RO, but not anti-CD45, enhanced TNF-alpha mRNA expression and decreased protein tyrosine phosphorylation of PMN. However, only anti-CD45RO suppressed Src family protein tyrosine kinase p56lck expression in the cells. These results suggest that the cross-linking of CD45 isoforms by their specific antibodies stimulated different PMN activities by differential suppression on protein tyrosine phosphorylation and Src family tyrosine kinase p56lck.

In our previous reports, we found polyclonal anti-double-stranded DNA antibodies (anti-dsDNA) purified from patients with active systemic lupus erythematosus (SLE) exerted inhibitory effect on [3H]thymidine incorporation of human mononuclear cells (MNC). However, the other immunological effects of anti-dsDNA on the functions of MNC have not yet been reported. In this study, two monoclonal antibodies, 12B3 and 9D7, with different anti-dsDNA activity were evaluated for their effects on the expression and release of different cytokines from human MNC. We confirmed absence of endotoxin in the two monoclonal antibody preparations and the used medium as detected by Limulus amoebocyte lysate test. The mRNA expression and release of different cytokines including interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were measured. We found the two monoclonal anti-dsDNA not only dose-responsively suppressed the phytohaemagglutinin (PHA)-induced thymidine uptake of human MNC but stimulated the mRNA expression of IL-1beta, IL-6 and IL-8 in normal human MNC detected by reverse transcription-polymerase chain reaction (RT-PCR). Enzyme-linked immunosorbent assay (ELISA) measurement of cytokines in MNC culture supernatants revealed that anti-dsDNA enhanced IL-1beta, IL-8, TNF-alpha and IL-10 release from resting MNC. These effects of anti-dsDNA antibodies were not affected by polymyxin B, a potent binder and neutralizer of lipopolysaccharide (LPS). These in vitro studies suggest that anti-dsDNA possess a dual effect on normal human MNC: (a) to enhance the release of proinflammatory cytokines (IL-1beta, IL-8 and TNF-alpha) from MNC to augment inflammatory reaction; and (b) to polarize the immune reaction towards the T helper 2 (Th2) (increased IL-10 production) pathway. This unique effect of anti-dsDNA may play a role in lupus pathogenesis by augmenting inflammatory reactions and autoantibody production which are commonly found in patients with active SLE.

Cold acclimation has been suggested to be mediated by alternations in the gene expression pattern in the cold-adapted fish. To investigate the mechanism of cold acclimation in fish brain at the molecular level, relevant subsets of differentially expressed genes of interest were identified and cloned by the PCR-based subtraction suppression hybridization. Characterization of the selected cold-induced cDNA clones revealed one encoding ependymin. This gene was shown to be brain-specific. The expression of ependymin was induced by a temperature shift from 25 degrees C to 6 degrees C in Cyprinus carpio or 12 degrees C in Danio rerio. Activation of ependymin was detected 2 h after cold exposure and peaked at more than 10-fold at 12 h. This peak level remains unchanged until the temperature returns to 25 degrees C. Although the amount of soluble ependymin protein in brain was not changed by cold treatment, its level in the fibrous insoluble polymers increased 2-fold after exposure to low temperature. These findings indicate that the increase in ependymin expression is an early event that may play an important role in the cold acclimation of fish.

Synthesis of multiple extracellular lipases in Candida rugosa has been demonstrated. However, it is difficult to characterize the expression spectrum of lip genes, since the sequences of the lip multigene family are very closely related. A competitive reverse transcription-PCR assay was developed to quantify the expression of lip genes. In agreement with the protein profile, the abundance of lip mRNAs was found to be (in decreasing order) lip1, lip3, lip2, lip5, and lip4. To analyze the effects of different culture conditions, the transcript concentrations for these mRNA species were normalized relative to the values for gpd, encoding glyceraldehyde-3-phosphate dehydrogenase. In relative terms, lip1 and lip3 were highly and constitutively expressed (about 10(5) molecules per microg of total RNA) whereas the other inducible lip genes, especially lip4, showed significant changes in mRNA expression under different culture conditions. These results indicate that differential transcriptional control of lip genes results in multiple forms of lipase proteins.

The study examined the articular cartilages of 14 patients who suffered from temporomandibular joint disturbance syndrome (TMJDS) and 3 healthy fresh cadavers by light microscopy and immunofluorescence, and assayed 14 patients' synovial fluids and sera with indirect hemoagglutination. The results showed that there were antibodies to type II collagen in synovial fluids in 5 of 14 patients and there were some immune complexes in cartilage. So, the authors think that there are autoimmune reactions in the articular tissues in TMJDS because of the exposure of some sequestered antigens.