Biomedical subjects

A Temiz Artmann

Publications and source records attributed to A Temiz Artmann.

4 recordsLinked to original sources

PubMed2007

Decrease in extracellular collagen crosslinking after NMR magnetic field application in skin fibroblasts.

Although biological effects of electromagnetic fields were investigated intensively, there is still no agreement on the significance of their effects. The underlying mechanisms and therapeutic importance are still mostly unknown too. In this study, primary cultures of human dermal fibroblasts were exposed to magnetic field at nuclear magnetic resonance (NMR) conditions for in total 5 days and 4 h/day. Among the investigated parameters were: cell proliferation rate, cell morphology, total protein concentration as well as content of skin-specific collagen types I, III, IV. NMR exposure induced distinct changes both in cellular and extracellular components. The extracellular matrix (ECM) of NMR-exposed cells had less cross-linked collagen. In particular, the increase of collagen of the soluble fraction was at 17.2 +/- 2.9% for type I, 27.0 +/- 1.86% for type III, 17.3 +/- 1.46% for type IV (N = 6). In the absence of resonance frequency, the effects of magnetic field on ECM were less profound.

Body Water↗

PubMed2006

Body temperature-related structural transitions of monotremal and human hemoglobin.

In this study, temperature-related structural changes were investigated in human, duck-billed platypus (Ornithorhynchus anatinus, body temperature T(b) = 31-33 degrees C), and echidna (Tachyglossus aculeatus, body temperature T(b) = 32-33 degrees C) hemoglobin using circular dichroism spectroscopy and dynamic light scattering. The average hydrodynamic radius (R(h)) and fractional (normalized) change in the ellipticity (F(obs)) at 222 +/- 2 nm of hemoglobin were measured. The temperature was varied stepwise from 25 degrees C to 45 degrees C. The existence of a structural transition of human hemoglobin at the critical temperature T(c) between 36-37 degrees C was previously shown by micropipette aspiration experiments, viscosimetry, and circular dichroism spectroscopy. Based on light-scattering measurements, this study proves the onset of molecular aggregation at T(c). In two different monotremal hemoglobins (echidna and platypus), the critical transition temperatures were found between 32-33 degrees C, which are close to the species' body temperature T(b). The data suggest that the correlation of the structural transition's critical temperature T(c) and the species' body temperature T(b) is not mere coincidence but, instead, is a more widespread structural phenomenon possibly including many other proteins.

Adult↗

PubMed2005

Adhesion of erythrocytes to endothelial cells after acute exercise: differences in red blood cells from juvenile and adult rats.

Erythrocytes (RBC) from untrained male Wistar rats and rat glomerular endothelial cells (EC) were used to investigate the effects of acute exercise (speed: 20 m/min, slope: 0, duration: 1 hour) on RBC membrane protein oxidation and adhesion to cultured EC. Experimental animals were divided into juvenile (age 10 weeks) and adult (age 30 weeks) groups for these studies. Immediately following exercise, juvenile rat RBC membrane protein oxidation was significantly enhanced. Adult rat RBC showed significantly higher basal protein oxidation than juvenile RBC; but the level of adult rat RBC membrane protein oxidation was unaffected by exercise. Prior to exercise, adult rat RBC showed significantly higher adhesion to EC than RBC of juvenile rat. There was no difference in plasma fibronectin or fibrinogen levels following exercise. Only juvenile rat RBC showed a significant decrease in sialic acid residue content following exercise. These experiments show that there are changes in RBC-EC interactions following exercise that are influenced by animal age.

Age Factors↗

PubMed2005

Bactericidal effects of plasma-generated cluster ions.

Air purification by plasma-generated cluster ions (PCIs) relies on a novel technology producing hydrated positive and negative ions. Phenomenological tests have shown strong evidence of lethal effects of the PCIs on various micro-organisms. However, the mechanisms of PCI action are still widely unknown. The aim was thus to test the bactericidal efficacy of PCI technology on common indoor micro-organisms and to explore possible PCI mechanisms of action. According to time/dose-dependent experiments with Staphylococcus, Enterococcus, Micrococcus and Bacillus, the inhibiting effects became apparent within the first few minutes of PCI exposure and led to an irreversible 99.9% destruction within the following 2-8 h of exposure. The destructive effect of the PCIs corresponded to membrane damage of the bacteria. Use of the techniques of both SDS PAGE and 2D PAGE revealed changes in the bacterial surface protein composition induced by the PCIs. In contrast, neither DNA nor cytoplasm protein damage was detected electrophoretically. The antimicrobial action of the PCIs seems to occur because of chemical modification of the surface proteins of bacteria. In situ hydroxyl radical formation on the surface of bacteria was proposed as the leading mechanism of the protein damage caused by the PCIs. At the same time, DNA damage seems not to be involved in the antibacterial action of the PCIs. The data obtained would broaden the knowledge concerning the antibacterial effects of air-born plasma-generated cluster ions and help to produce more efficient air-cleaning devices.

Air Ionization↗