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H Stimulation (h + stimulation)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

In vitro detection of cytotoxic T and NK cells in peripheral blood of patients with various drug-induced skin diseases

ALLERGY, Issue 3 2010
A. Zawodniak
To cite this article: Zawodniak A, Lochmatter P, Yerly D, Kawabata T, Lerch M, Yawalkar N, Pichler WJ. In vitro detection of cytotoxic T and NK cells in peripheral blood of patients with various drug-induced skin diseases. Allergy 2010; 65: 376,384. Abstract Background:, Cytotoxic cells are involved in most forms of drug-induced skin diseases. Till now, no in vitro test addressed this aspect of drug-allergic responses. Our report evaluates whether drug-induced cytotoxic cells can be detected in peripheral blood of nonacute patients with different forms of drug hypersensitivity, and also whether in vitro detection of these cells could be helpful in drug-allergy diagnosis. Methods:, GranzymeB enzyme-linked immunosorbent spot-forming (ELISPOT) and cell surface expression of the degranulation marker CD107a were evaluated on peripheral blood mononuclear cells from 12 drug-allergic patients in remission state and 16 drug-exposed healthy controls. Results:, In 10/12 allergic patients culprit but not irrelevant drug elicited granzymeB release after 48,72 h stimulation. It was clearly positive in patients with high proliferative response to the drug, measured in lymphocyte transformation tests. In patients, who showed moderate or low proliferation and low drug-response in granzymeB ELISPOT, overnight preincubation with interleukin (IL)-7/IL-15 enhanced drug-specific granzymeB release and allowed to clearly identify the offending agent. CD107a staining was positive on CD4+/CD3+, CD8+/CD3+ T cells as well as CD56+/CD3, natural killer cells. None of the drug-exposed healthy donors reacted to the tested drugs and allergic patients reacted only to the offending, but not to tolerated drugs. Conclusion:, GranzymeB ELISPOT is a highly specific in vitro method to detect drug-reacting cytotoxic cells in peripheral blood of drug-allergic patients even several years after disease manifestation. Together with IL-7/IL-15 preincubation, it may be helpful in indentifying the offending drug even in some patients with weak proliferative drug-response. [source]

A transcriptomic and proteomic analysis of the effect of CpG-ODN on human THP-1 monocytic leukemia cells

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2005
Cheng-Chin Kuo
Abstract The CpG motif of bacterial DNA (CpG-DNA) is a potent immunostimulating agent whose mechanism of action is not yet clear. Here, we used both DNA microarray and proteomic approaches to investigate the effects of oligodeoxynucleotides containing the CpG motif (CpG-ODN) on gene transcription and protein expression profiles of CpG-ODN responsive THP-1 cells. Microarray analysis revealed that 2,h stimulation with CpG-ODN up-regulated 50,genes and down-regulated five genes. These genes were identified as being associated with inflammation, antimicrobial defense, transcriptional regulation, signal transduction, tumor progression, cell differentiation, proteolysis and metabolism. Longer stimulation (8,h) with CpG-ODN enhanced transcriptional expression of 58,genes. Among these 58,genes, none except one, namely WNTI inducible signaling pathway protein,2, was the same as those induced after 2,h stimulation. Proteomic analysis by two-dimensional gel electrophoresis, followed by mass spectrometry identified several proteins up-regulated by CpG-ODN. These proteins included heat shock proteins, modulators of inflammation, metabolic proteins and energy pathway proteins. Comparison of microarray and proteomic expression profiles showed poor correlation. Use of more reliable and sensitive analyses, such as reverse transcriptase polymerase chain reaction, Western blotting and functional assays, on several genes and proteins, nonetheless, confirmed that there is indeed good correlation between mRNA and protein expression after CpG-ODN treatment. This study also revealed that several anti-apoptotic and neuroprotective related proteins, not previously reported, are activated by CpG-DNA. These findings have extended our knowledge on the activation of cells by CpG-DNA and may contribute to further understanding of mechanisms that link innate immunity with acquired immune response(s). [source]

Pulsed electromagnetic fields affect osteoblast proliferation and differentiation in bone tissue engineering

BIOELECTROMAGNETICS, Issue 7 2007
Ming-Tzu Tsai
Abstract Bone tissue engineering is an interdisciplinary field involving both engineers and cell biologists, whose main purpose is to repair bone anatomical defects and maintain its functions. A novel system that integrates pulsed electromagnetic fields (PEMFs) and bioreactors was applied to bone tissue engineering for regulating osteoblast proliferation and differentiation in'vitro. Osteoblasts were acquired from the calvaria of newborn Wistar rats and isolated after sequential digestion. Poly(DL -lactic-co-glycolic acid) (PLGA) scaffolds were made by the solvent merging/particulate leaching method. Osteoblasts were seeded into porous PLGA scaffolds with 85% porosity and cultured in bioreactors for the 18-day culture period. Cells were exposed to PEMF pulsed stimulation with average (rms) amplitudes of either 0.13, 0.24, or 0.32 mT amplitude. The resulting induced electric field waveform consisted of single, narrow 300 µs quasi-rectangular pulses with a repetition rate of 7.5'Hz. The results showed that PEMF stimulation for 2 and 8 h at .13 mT increased the cell number on days 6 and 12, followed by a decrease on day 18 using 8 h stimulation. However, ALP activity was decreased and then increased on days 12 and 18, respectively. On the other hand, PEMF-treated groups (irrespective of the stimulation time) at 0.32 mT inhibited cell proliferation but enhanced ALP activity during the culture period. These findings suggested that PEMF stimulation with specific parameters had an effect on regulating the osteoblast proliferation and differentiation. This novel integrated system may have potential in bone tissue engineering. Bioelectromagnetics 28:519,528, 2007. © 2007 Wiley-Liss, Inc. [source]

Stimulation of cardiac ,-adrenoceptors targets connexin 43

BRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2009
Kerstin Boengler
Connexin 43 (Cx43) is the major protein of cardiac ventricular gap junctions and is crucial to cell,cell communication and cardiac function. The protein level of Cx43 is reduced in patients with heart failure or dilated cardiomyopathy (DCM), pathophysiological conditions often associated with arrhythmias. As catecholamines are often increased in cardiac diseases, Salameh et al., in this issue of the BJP, investigated the effect of ,-adrenoceptor stimulation of neonatal cardiomyocytes on Cx43 expression and found increased Cx43 mRNA and protein levels following 24 h stimulation. Up-regulation of Cx43 was associated with phosphorylation of mitogen-activated protein kinases and translocation of transcription factors into the nucleus. In patients with DCM, a situation often associated with desensitization of the ,-adrenoceptor system, Cx43 expression was reduced. The characterization of the signal transduction pathways involved in Cx43 expression and intracellular localization in human myocardium in vivo is a promising target for the development of new anti-arrhythmic strategies. [source]