Search results for "Biophysics"
showing 10 items of 3515 documents
Dependence of T-lymphocyte activation on the extent of cellular damage
2010
Mechanically damaged cells release intracellular substances, resulting in the activation of CD4- and CD8-positive T-lymphocytes. The goal of this investigation was to quantify and compare fractions of activated CD4- and CD8-positive T-lymphocytes, based on the quantity of damaged cells in a given blood sample. Blood samples were mechanically stressed by vortexing intensely. Subsequently, different quantities of distressed blood samples were mixed with samples of fresh, whole blood. Afterwards, the extent of CD4- and CD8-positive T-cell activation was examined in the mixture by flow cytometry. Sine-like curves of T-cell activation were observed for both CD4- (T-helper mediated) and CD8- (cyt…
Paracentrin 1, a synthetic antimicrobial peptide from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa…
2014
The rise of antibiotic-resistance as well as the reduction of investments by pharmaceutical companies in the development of new antibiotics have stimulated the investigation for alternative strategies to conventional antibiotics. Many antimicrobial peptides show a high specificity for prokaryotes and a low toxicity for eukaryotic cells and, due to their mode of action the development of resistance is considered unlikely. We recently characterized an antimicrobial peptide that was called Paracentrin 1 from the 5-kDa peptide fraction from the coelomocyte cytosol of the Paracentrotus lividus. In this study, the chemically synthesized Paracentrin 1, was tested for its antimicrobial and antibiof…
Optical biosensor-based characterization of anti-double-stranded DNA monoclonal antibodies as possible new standards for laboratory tests.
2009
The serum determination of circulating anti-double-stranded (ds)DNA autoantibodies is a routine measure for the laboratory diagnosis of systemic lupus erythematosus. Since available assays differ substantially and no feasible calibrator is available, the aim of this study was to evaluate a recently introduced surface plasmon resonance (SPR) biosensor chip for binding studies between dsDNA and anti-dsDNA autoantibodies and to demonstrate its usefulness for the characterization of new monoclonal antibody (mAb) standards and standardization of assays. We characterized two human and one murine monoclonal anti-dsDNA antibodies by measuring the kinetic on- and off-rates using the biosensor and ca…
Identification and characterization of a monoclonal antibody to the membrane fatty acid binding protein
1992
A monoclonal antibody to the rat liver membrane fatty acid binding protein (MFABP) was prepared by immunizing mice with purified MFABP isolated from solubilized rat liver plasma membrane proteins by oleate-agarose affinity chromatography technique. The monoclonal antibody K15/6 identified a single 40 kDa protein in rat liver plasma membranes with pI values of 8.5, 8.8 and 9.0, which is identical to the authentic MFABP, but clearly distinct from rat mitochondrial GOT. The antibody K15/6 selectively inhibited cellular influx as well as membrane binding of fatty acids, but not of cholesterol or vitamin E. The same antibody was used in immunofluorescence, ELISA and Western blot analysis to dete…
Geranylgeranyl as well as farnesyl moiety is transferred to Ras p21 overproduced in adrenocortical cells transformed by c-Ha-rasEJ oncogene.
1997
The ras-transformed newborn rat adrenocortical (RTAC) cells were obtained by transfection with the mutated c-Ha-rasEJ oncogene. They are proliferative and tumorigenic cells characterized by expression of the c-Ha-rasEJ oncogene and overexpression of a wild-type ras oncogene. The overproduced Ras p21 was identified here as Ki-Ras p21 by western blotting using a specific anti-Ki-Ras monoclonal antibody. Radioactivity derived from [14C]mevalonolactone was strongly incorporated into Ras p21 overproduced in RTAC cells. RTAC cells pretreated with lovastatin and labeled with either [3H]geranylgeranyl-pyrophosphate or [3H]farnesyl-pyrophosphate incorporated also radioactivity into Ras p21. These re…
Alteration of loosely bound calcium in the guinea pig organ of Corti after treatment with diltiazem as calcium channel blocker
1997
After oral administration of the organic calcium channel blocker diltiazem to guinea pigs for 7 days, calcium ions were precipitated with potassium antimonate in the cochleae. The spatial distribution of the precipitates was studied by energy-filtering transmission electron microscopy and the amount of the ultrastructural reaction products formed was determined semiquantitatively by an image processing system. Compared with untreated control ears, the number of the formed precipitates was reduced drastically in the inner hair cells after diltiazem treatment. In addition, electron microscopic analysis revealed that the number of calcium precipitates attached at the basolateral membrane of th…
New hydrogel matrices containing an anti-inflammatory agent. Evaluation of in vitro release and photoprotective activity.
2002
In the present work. the preparation and characterization of hydrogels based on alpha,beta-polyaspartylhydrazide (PAHy) chemically crosslinked with ethyleneglycol diglycidylether (EGDGE) containing Tolmetin sodium salt, are reported. In particular, these samples have been prepared both as water swellable microparticles and as gels at two different crosslinking degrees. The incorporation of Tolmetin sodium salt in PAHy-EGDGE microparticles has been performed after the crosslinking reaction by a soaking procedure or during the formation of the network. The influence of drug loading procedure on Tolmetin release has been evaluated by performing in vitro release study in simulated gastrointesti…
Immunonegative Staining: Epitope Localization on Macromolecules
1996
Relevant literature relating to immunonegative staining is reviewed and integrated with current research of the author and others. The immunonegative staining procedure has been utilized for the study of epitope localization on immune complexes formed from keyhole limpet hemocyanin type 2 (KLH2) di- and multidecamers, and the 20S and 26S proteasome from Xenopus laevis. The IgG linkage pattern of molecules in small immune complexes is considered to provide the most reliable indication of epitope location. For both KLH2 and the 20S proteasome, using domain-specific monoclonal antibodies and a 32-kDa (p32) subunit-specific polyclonal antibody, respectively, it is shown that epitopes (KLH2, sub…
On the Use of XML in Medical Imaging Web-Based Applications
2016
The rapid growth of digital technology in medical fields over recent years has increased the need for applications able to manage patient medical records, imaging data, and chart information. Web-based applications are implemented with the purpose to link digital databases, storage and transmission protocols, management of large volumes of data and security concepts, allowing the possibility to read, analyze, and even diagnose remotely from the medical center where the information was acquired. The objective of this paper is to analyze the use of the Extensible Markup Language (XML) language in web-based applications that aid in diagnosis or treatment of patients, considering how this proto…
Effect of footwear on plantar flexor fine-wire electromyography activity in walking
2019
Compared to barefoot walking, walking in footwear seems to alter plantar flexor electromyography (EMG) activity, vertical and horizontal ground reaction forces (Sacco, Akashi, & Hennig, 2010), ankle kinematics and the time of peak activity (Sacco et al., 2010). However, study results are inconsistent regarding the magnitude and direction of these changes. Magnetic resonance imaging showed high inter-individual variability in muscle metabolic activity during walking, suggesting individual-specific activation patterns (Kolk et al., 2015). Additionally, little is known about the role of toe flexors such as flexor hallucis longus (FHL) in walking.