A novel titanium implant surface modification by plasma electrolytic oxidation (PEO) preventing tendon adhesion.

Titanium is one of the most commonly used materials for implants in trauma applications due to its low density, high corrosion resistance and biocompatibility. Nevertheless, there is still a need for improved surface modifications of Titanium, in order to change surface properties such as wettability, antibacterial properties or tissue attachment. In this study, different novel plasma electrolytic oxidation (PEO) modifications have been investigated for tendon adhesion to implants commonly used in hand surgery.

Uncoupling effect of fatty acids in halo- and alkalotolerant bacterium Bacillus pseudofirmus FTU.

Natural uncouplers of oxidative phosphorylation, long-chain non-esterified fatty acids, cause uncoupling in the alkalo- and halotolerant bacterium Bacillus pseudofirmus FTU. The uncoupling effect in the bacterial cells was manifested as decrease of membrane potential and increase of respiratory activity. The membrane potential decrease was detected only in bacterial cells exhausted by their endogenous substrates.

Cyclosporin A-sensitive decrease in the transmembrane potential across the inner membrane of liver mitochondria induced by low concentrations of fatty acids and Ca2+.

At low Ca2+ concentrations the pore of the inner mitochondrial membrane can open in substates with lower permeability (Hunter, D. R., and Haworth, R.

A cytochrome c mutant with high electron transfer and antioxidant activities but devoid of apoptogenic effect.

A cytochrome c mutant lacking apoptogenic function but competent in electron transfer and antioxidant activities has been constructed. To this end, mutant species of horse and yeast cytochromes c with substitutions in the N-terminal alpha-helix or position 72 were obtained. It was found that yeast cytochrome c was much less effective than the horse protein in activating respiration of rat liver mitoplasts deficient in endogenous cytochrome c as well as in inhibition of H(2)O(2) production by the initial segment of the respiratory chain of intact rat heart mitochondria.

Role of the ADP/ATP-antiporter in fatty acid-induced uncoupling of Ca2+-loaded rat liver mitochondria.

We show that Ca2+ loading of mitochondria substantially augments the myristate-induced decrease in the transmembrane electric potential difference (deltapsi). Such a Ca2+ action is without effect on the respiration rate and is not accompanied by the high-amplitude swelling when low concentrations of Ca2+ and myristate are used. The myristate-induced deltapsi decrease is prevented and reversed by cyclosporin A (CsA); the decrease is prevented and transiently reversed by nigericin.

Generation of transmembrane electrical potential during NADH oxidation via the external pathway and the fatty acid uncoupling effect after transient opening of the Ca2+-dependent cyclosporin A-sensitive pore in liver mitochondria.

The effects of transient pore opening on generation of the transmembrane gradient of electrical potential across the inner mitochondrial membrane (DeltaPsi) induced by NADH oxidation through the external pathway as well as on the uncoupling effect of fatty acids were studied. The pore opening was monitored by changes in the DeltaPsi value. The cycle of pore opening/closing was found to have only an insignificant effect on the sensitivity of DeltaPsi to fatty acid uncoupling.

Membrane potential generation coupled to oxidation of external NADH in liver mitochondria.

Oxidation of added NADH by rat liver mitochondria has been studied. It is found that exogenous NADH, when oxidized by rat liver mitochondria in sucrose hypotonic medium supplemented with Mg2+ and EGTA, generates a membrane potential (delta psi) even in the absence of added cytochrome c. ADP and phosphate decrease delta psi, the effect being reversed by oligomycin.

[Participation of the ADP/ATP-antiporter in the uncoupling action of fatty acids in liver mitochondria].

The controversial data on the involvement of the ATP/ADP-antiporter in the uncoupling effect of fatty acids in liver mitochondria as well as on the sensitivity of the uncoupling process to the ATP/ADP-antiporter inhibitor, carboxyatractylate, have been analyzed. It has been shown that in liver mitochondria uncoupled by palmitic acid, pyridoxal-5-phosphate, diethyl pyrocarbonate and glutamate produce an additional recoupling action against the background of carboxyatractylate. No such effect is observed during mitochondrial uncoupling by FCCP.