Biophysical and biochemical properties of a binary lipid mixture for DNA transfection.

The phase and miscibility behavior of a triple-chain phosphatidylcholine (TPHPC) and a single-chain surfactant (CTAB) were investigated in aqueous dispersions and in monolayers at the air/water interface. CTAB can be incorporated in the TPHPC monolayer because of its complementary molecule shape and reduces the tilt angle of TPHPC. The type of phases and the phase sequence (L2 - LS) are the same in the pure TPHPC monolayer and in the TPHPC/CTAB (80:20 mol:mol) mixture. No indication of any ordering of adsorbed DNA was observed. In the aqueous dispersions, TPHPC exhibits an inverted hexagonal phase above the chain melting. The addition of 30 mol% CTAB leads to the appearance of a lamellar Lalpha phase. The binding of DNA to the mixture is obvious but this is accompanied by a separation of the two lipids what is supported by monolayer experiments. The system has no long-term stability. The main reason seems to be not only the stronger interaction of DNA with CTAB, but also especially the unexpected weak interaction between CTAB and TPHPC. The transfection efficiency is lower compared with lipofectamine. The main disadvantage of this system is the cytotoxicity of CTAB, which could not be lowered by incorporation of CTAB in the TPHPC bilayer.

Ability of fractionated petroleum refinery effluent to elicit cyto- and photocytotoxic responses and to induce 7-ethoxyresorufin-O-deethylase activity in fish cell lines.

The ability of fractionated petroleum refinery effluent to cause cellular responses in fish cell lines was evaluated. The cellular responses, which included direct and indirect cytotoxicity, photocytotoxicity and induction of 7-ethoxyresorufin-O-deethylase (EROD) activity, may potentially be linked to sublethal effects observed in effluent-exposed fish and fish larvae. In order to be able to quantify cellular responses rapidly, microtitre plates were used along with fluorescent probes. For the quantification of cyto- and photocytotoxicity, the fluorescent probes were alamar Blue and carboxyfluorescein diacetate acetoxymethyl ester (CFDA-AM), which monitor metabolic activity and cell membrane integrity, respectively. EROD activity was measured as the rate of conversion by EROD of the substrate 7-ethoxyresorufin to its fluorescent product, resorufin. Effluent from an Ontario refinery was fractionated into aqueous and particulate phase. As well, a solid phase extract (SPE) was used to prepare concentrated effluent for testing in the cell lines. The effluent was able to elicit all of the responses of interest although significant cyto- and photocytotoxicity required effluent equivalent concentrations above 100% effluent and could only be revealed upon exposure of cells to the SPE concentrated effluent. Based on their retention on C18, the cytotoxicants are likely to be non-polar to moderately polar chemicals. The presence of polar compounds affecting cellular metabolism was indicated by the responses of exposed cells to a 90% aqueous phase effluent. In contrast to cyto- and photocytotoxicity, EROD induction occurred at effluent equivalent concentrations well below 100% effluent and was elicited by the SPE and the particulate fraction thereby suggesting that most EROD-inducers were particle-bound. Among other applications, the described techniques could help to determine the source of causative agents of sublethal effects in the refining process.

[Effectiveness of Formica rufa and autologous blood injection in patients with ankylosing spondylitis: a double-blind randomized study]. / Wirksamkeit von Formica rufa und Eigenblut-Injektionen bei Patienten mit ankylosierender Spondylitis: eine doppelblinde, randomisierte Studie.

While complementary medicine and homeopathy is becoming an increasingly prominent part of the health care practices, there is a lack of controlled studies concerning their effectiveness. In our study, we wanted to answer the question whether a combination of Formica rufa D6 and reinjection of the patient's own blood is superior to injection of placebo. 104 patients with ankylosing spondylitis entered a prospective, randomized, double-blind study. During four weeks they received twice weekly either 1 ml of Formica rufa D6 in combination with 0.5 ml of blood or 1.5 ml NaCl intramuscular. Before and after therapy, mobility, thoracic excursion and doctor's overall assessment were measured in addition to patient's health status, using a German version of the Arthritis Impact Measurement Scales, before and after therapy as well as four, twelve, and twenty-four weeks later. We were not able to detect any statistical difference between treatment and placebo group in any of the parameters measured. Therefore, the therapy under study may not be regarded effective.