Search results for "T cell"
showing 10 items of 2228 documents
CYP2D6 increases toxicity of the designer drug 4-methylthioamphetamine (4-MTA)
2006
4-Methylthioamphetamine (4-MTA) belongs to a group of new amphetamine derivatives that is usually sold as "ecstasy" or "flatliners" on the illicit drug market. Large interindividual differences in 4-MTA mediated toxicity have been reported in humans. Therefore, we tested whether CYP2D6 or its variant alleles as well as CYP3A4 influence the susceptibility to 4-MTA. For this purpose, we used the colony formation assay with Chinese hamster lung fibroblast V79 cells expressing human wild-type CYP2D6 (CYP2D6*1), the low activity alleles CYP2D6*2, CYP2D6*9, as well as human CYP3A4. The obtained results showed that the expression of wild type CYP2D6*1 clearly enhanced the susceptibility to the cyt…
Identification of the plant compound geraniin as a novel Hsp90 inhibitor
2013
Besides its function in normal cellular growth, the molecular chaperone heat shock protein 90 (Hsp90) binds to a large number of client proteins required for promoting cancer cell growth and/or survival. In an effort to discover new small molecules able to inhibit the Hsp90 ATPase and chaperoning activities, we screened, by a surface plasmon resonance assay, a small library including different plant polyphenols. The ellagitannin geraniin, was identified as the most promising molecule, showing a binding affinity to Hsp90α similar to that of 17-(allylamino)-17-demethoxygeldanamycin (17AGG). Geraniin was able to inhibit in vitro the Hsp90α ATPase activity in a dose−dependent manner, with an in…
Porcine Dermis-Derived Collagen Membranes Induce Implantation Bed Vascularization Via Multinucleated Giant Cells: A Physiological Reaction?
2014
In this study, the tissue reactions to 2 new porcine dermis-derived collagen membranes of different thickness were analyzed. The thicker material (Mucoderm) contained sporadically preexisting vessel skeletons and fatty islands. The thinner membrane (Collprotect) had a bilayered structure (porous and occlusive side) without any preexisting structures. These materials were implanted subcutaneously in mice to analyze the tissue reactions and potential transmembranous vascularization. Histological and histomorphometrical methodologies were performed at 4 time points (3, 10, 15, and 30 days). Both materials permitted stepwise connective tissue ingrowth into their central regions. In the Mucoderm…
High-Temperature Sintering of Xenogeneic Bone Substitutes Leads to Increased Multinucleated Giant Cell Formation: In Vivo and Preliminary Clinical Re…
2014
The present preclinical and clinical study assessed the inflammatory response to a high-temperature–treated xenogeneic material (Bego-Oss) and the effects of this material on the occurrence of multinucleated giant cells, implantation bed vascularization, and regenerative potential. After evaluation of the material characteristics via scanning electron microscopy, subcutaneous implantation in CD-1 mice was used to assess the inflammatory response to the material for up to 60 days. The clinical aspects of this study involved the use of human bone specimens 6 months after sinus augmentation. Established histologic and histomorphometric analysis methods were applied. After implantation, the mat…
TRAP-Positive Multinucleated Giant Cells Are Foreign Body Giant Cells Rather Than Osteoclasts: Results From a Split-Mouth Study in Humans
2014
This study compared the material-specific tissue response to the synthetic, hydroxyapatite-based bone substitute material NanoBone (NB) with that of the xenogeneic, bovine-based bone substitute material Bio-Oss (BO). The sinus cavities of 14 human patients were augmented with NB and BO in a split-mouth design. Six months after augmentation, bone biopsies were extracted for histological and histomorphometric investigation prior to dental implant insertion. The following were evaluated: the cellular inflammatory pattern, the induction of multinucleated giant cells, vascularization, the relative amounts of newly formed bone, connective tissue, and the remaining bone substitute material. NB gra…
Foreign Body Giant Cell–Related Encapsulation of a Synthetic Material Three Years After Augmentation
2016
Bone substitute materials of different origin and chemical compositions are frequently used in augmentation procedures to enlarge the local bone amount. However, relatively little data exist on the long-term tissue reactions. The presented case reports for the first time histological and histomorphometrical analyses of a nanocrystaline hydroxyapatite–based bone substitute material implanted in the human sinus cavity after an integration period of 3 years. The extracted biopsy was analyzed histologically and histomorphometrically with focus on the tissue reactions, vascularization, new bone formation, and the induction of a foreign body reaction. A comparably high rate of connective tissue (…
Autoradiographische Beobachtungen �ber den Einbau von3H-Uridin in herpesinduzierten Riesenzellen
1968
Cytological studies indicate that Herpes induced polykaryocytes often contain normal appearing nuclei. Further, virus induced DNA-synthesis was absent in about 20% of the nuclei inside of giant cells as observed by autoradiography. On the other hand, RNA-synthesis seems to be inhibited in all nuclei of such cells as evidenced by reduced3H-uridin incorporation. It is concluded that nuclear RNA-synthesis is blocked by spreading of inhibitory factors.
Does Exist A Correlation Between BMI and Gleason Patterns 4 and 5 At Prostate Biopsy?
2013
Background: Obesity has been related with higher Gleason grade and worse prognosis. Increasing proportion of Gleason pattern 4 or 5 is a critical factor for biochemical recurrence, progression and mortality. The endocrine activity of visceral fat could be responsible of the differentation of the prostatic malignant cell towards a more aggressive fenotype. The aim of our study was to correlate Body Mass Index with the presence of Gleason pattern 4 or higher at biopsy. Materials and Methods: Consecutive patients with positive prostate biopsy were included. A transrectal prostate biopsy procedure with 12 cores, was performed. All tissue samples were reviewed. Results: Out of 135 patients diagn…
Active Site Mapping of Xylan-Deconstructing Enzymes with Arabinoxylan Oligosaccharides Produced by Automated Glycan Assembly
2017
Xylan-degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as the production of biofuel. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2-substituted, 3-substituted, and 2-/3-substituted arabino- and glucuronoxylan oligosaccharides. Elongation of the xylan backbone relied on iterative additions of C4-fluorenylmethoxylcarbonyl (Fmoc) protected xylose building blocks to a linker-functionalized …
A novel cytotoxin from Clostridium difficile serogroup F is a functional hybrid between two other large clostridial cytotoxins.
1999
Abstract The large clostridial cytotoxins (LCTs) constitute a group of high molecular weight clostridial cytotoxins that inactivate cellular small GTP-binding proteins. We demonstrate that a novel LCT (TcdB-1470) from Clostridium difficile strain 1470 is a functional hybrid between “reference” TcdB-10463 andClostridium sordellii TcsL-1522. It bound to the same specific receptor as TcdB-10463 but glucosylated the same GTP-binding proteins as TcsL-1522. All three toxins had equal enzymatic potencies but were equally cytotoxic only when microinjected. When applied extracellularly TcdB-1470 and TcdB-10463 were considerably more potent cytotoxins than TcsL-1522. The small GTP-binding protein R-R…