Therapeutic effect of methotrexate encapsulated in cationic liposomes (EndoMTX) in comparison to free methotrexate in an antigen-induced arthritis study in vivo.

OBJECTIVES: Cationic lipid complexes bind to angiogenic endothelial cells of solid tumours and microvessels of chronic inflammatory tissue. Methotrexate (MTX) is one of the drugs used in the therapy of rheumatoid arthritis (RA); it is applied systemically but can have serious side-effects. The aim of this study was to investigate the impact of MTX encapsulated in cationic liposomes (EndoMTX) in comparison to treatment with free MTX. METHOD: We used an antigen-induced arthritis (AiA) model and investigated the leucocyte- and platelet-endothelial cell interaction in arthritic female C57/Bl6 mice and in healthy controls. The arthritic animals were divided into four different groups receiving either trehalose, free MTX, EndoMTX placebo, or EndoMTX. These parameters and functional capillary density (FCD) were measured and assessed by intravital microscopy (IVM). We controlled clinical parameters such as the knee joint diameter (KJD) throughout the observation period. RESULTS: Animals treated with EndoMTX showed a significant and superior reduction in leucocyte- and platelet-endothelial cell interaction, FCD, and KJD. Free MTX or empty liposomes also showed a reduction in these parameters but not to a significant level. FCD decreased in the EndoMTX group in comparison to using free drugs or empty carrier-like liposomes. CONCLUSIONS: This study demonstrates the advantage of using MTX encapsulated in cationic liposomes in contrast to free and generic MTX, with a higher efficacy in anti-inflammatory and anti-angiogenic abilities. Targeting with cationic liposomes may be a promising treatment option and should be elucidated in further experiments regarding dose reduction and side-effects due to MTX usage.

Timing of cervical spine stabilisation and outcome in patients with rheumatoid arthritis.

One complication of rheumatoid arthritis (RA) is the involvement of the cervical spine (CS). Although prophylactic stabilisation is recommended, the timing at which this should occur is poorly defined. The aim of our study was to evaluate the course of neurological symptoms in terms of the timing of surgery. A total of 34 patients with RA and CS involvement were surgically stabilised. These patients were classified using the Ranawat (RW) score both preoperatively and at an average of 54 months post-operatively. For each patient, the presence of atlantoaxial and subaxial subluxation as well as vertical migration of the odontoid was recorded. The anterior atlantodental interval was also assessed pre- and post-operatively. Improvement was obtained in 20 patients, the clinical situation remained unchanged in three patients and three patients manifested disease progression. In terms of the RW score, the 16 patients with pre-operative RW grades I-II showed no deterioration at the post-operative follow-up, with 13 of these patients showing an improvement; the 12 patients with pre-operative RW grades IIIA-IIIB did not show any improvement of neurological symptoms at follow-up, although seven of these patients subjectively assessed the symptoms to be less severe after surgery; three other patients showed a worsening of symptoms. Our results suggest that preventive stabilisation of CS in RA leads to acceptable results, although the complications of the surgery are obvious. However, early operative treatment may delay the detrimental course of cervical myelopathy in RA.

Interaction of bacterial glucose-6-phosphate dehydrogenase with triazine dyes: a study by means of affinity partitioning and kinetic analysis.

The interaction of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) from Pseudomonas W6 with 33 triazine dyes bound to poly(ethylene glycol) has been screened by means of affinity partition in an aqueous two-phase system composed of poly-(ethylene glycol) and dextran. Regarding the strength of interaction expressed by the affinity partitioning effect three groups of dyes can be distinguished showing high, medium or low interaction to the enzyme. The different influence of the structurally related dyes Cibacronblue F3G-A, Procion Blue MX-3G and Procion Blue MX-R on the partitioning of glucose-6-phosphate dehydrogenase is discussed. Both coenzymes of this glucose-6-phosphate dehydrogenase, NADP+ and NAD+, are able to diminish the dye-enzyme interactions but to a different extent. In the case of Procion Red HE-3B less than 0.2 mM of NADP+ abolished completely the dye-protein interaction indicating that the dye binding site might be closely related to the nucleotide binding site. This does not hold for a series of other dyes revealing strong interactions to the enzyme. In these cases higher NADP(+)-concentrations are necessary to weaken the dye-enzyme interactions. Only small influences on the interaction between the dye and glucose-6-phosphate dehydrogenase were found with 1 mM NAD+. The different effects of the two coenzymes are discussed with respect to separate binding sites for them and to different conformational states induced. The competition of Procion Red HE-3B with NADP+ and NAD+ for the binding site of glucose-6-phosphate dehydrogenase was also demonstrated by inhibition studies. The Ki-values of Procion Red HE-3B with NAD+ and NADP+, respectively, were calculated.