Systemic histopathology of rats treated with 6-sulfanilamidoindazole, a novel arthritogenic sulfonamide

Synthesis of N-cyano-substituted sulfilimine and sulfoximine derivatives of S0859 and their biological evaluation as sodium bicarbonate co-transport inhibitors

Two analogs of S0859 have been synthesized and their effects on Na⁺,HCO₃⁻ co-transport activity have been evaluated.

Translation Strategy for the Qualification of Drug-induced Vascular Injury Biomarkers

Drug-induced vascular injury (DIVI) is a common preclinical toxicity usually characterized by hemorrhage, vascular endothelial and smooth muscle damage, and inflammation. DIVI findings can cause delays or termination of drug candidates due to low safety margins. The situation is complicated by the absence of sensitive, noninvasive biomarkers for monitoring vascular injury and the uncertain relevance to humans. The Safer And Faster Evidence-based Translation (SAFE-T) consortium is a public–private partnership funded within the European Commission’s Innovative Medicines Initiative (IMI) aiming to accelerate drug development by qualifying biomarkers for drug-induced organ injuries, including DIVI. The group is using patients with vascular diseases that have key histomorphologic features (endothelial damage, smooth muscle damage, and inflammation) in common with those observed in DIVI, and has selected candidate biomarkers associated with these features. Studied populations include healthy volunteers, patients with spontaneous vasculitides and other vascular disorders. Initial results from studies with healthy volunteers and patients with vasculitides show that a panel of biomarkers can successfully discriminate the population groups. The SAFE-T group plans to seek endorsement from health authorities (European Medicines Agency and Food and Drug Administration) to qualify the biomarkers for use in regulatory decision-making processes.

Simultaneous detection of antibacterial sulfonamides in a microfluidic device with amperometry

A highly sensitive and robust method for simultaneous detection of five sulfonamide drugs is developed by integrating the preconcentration and separation steps in a microfluidic device. An ampetrometry is performed for the selective detection of sulfonamides using an aluminum oxide-gold nanoparticle (Al(2)O(3)-AuNPs) modified carbon paste (CP) electrode at the end of separation channel. The preconcentration capacity of the channel is enhanced by using the field amplified sample stacking and the field amplified sample injection techniques. The experimental parameters affecting the analytical performances, such as pH, % of Al(2)O(3), volume of AuNPs, buffer concentration, and water plug length are optimized. A reproducible response is observed during the multiple injections of samples with RSDs<4%. The calibration plots are linear with the correlation coefficient between 0.991 and 0.997 over the range between 0.01 and 2025pM. The detection limits of five drugs are determined to be between 0.91 (±0.03) and 2.21 (±0.09)fM. The interference effects of common biological compounds are also investigated and the applicability of the method to the direct analysis of sulfonamides in real meat samples is successfully demonstrated. Long term stability of the modified electrode was also investigated.

Role of endotoxin in 6-sulfanilamidoindazole(6SAI)-induced arthritis in rats

6-Sulfanilamidoindazole (6SAI) induces selflimiting arthritis in rats. Since close relationships exist between arthritis and endotoxin, four experiments were conducted to clarify the relationship between endotoxin and 6SAI-induced arthritis. Endotoxin levels in the plasma from the abdominal aorta and portal vein from rats that had 6SAI (500 mg/kg) administered orally for up to 7 days remained within the control values at day 1 and day 3, and were significantly elevated at day 7. Endotoxin levels in the synovial fluid from the same rats showed no significant change. Ankle swelling and redness in rats treated 11 consecutive days with 6SAI did not ameliorate when coadministered with an anti-endotoxin agent, polymyxin B sulfate. Histopathological examination on the ankles of rats treated orally with non-arthiritogenic sulfonamides including sulfonamide, sulfamethoxazole and sulfadimethoxin (250 and 500 mg/kg/day, each compound) for 2 weeks demonstrated no inflammatory changes, while hyperplasia/hypertrophy of thyroid epithelial cells were frequently observed. When histopathological changes in the ankles from rats coadministered with 6SAI and lipopolysaccharide (LPS, Escherihia coli O55:B5, 50 microg/kg, i.v.) were compared with those in rats treated with 6SAI or LPS alone, the ankles from the 6SAI+LPS treated animals had marked edematous inflammation in the synovium and surrounding connective tissues, whereas the LPS-group had only mild focal infiltration of polymorphonuclear leukocytes in the synovium and the 6SAI-group showed no apparent changes. These results suggest that endotoxin is not a direct cause but a possible acceralating factor of 6SAI-induced arthritis, and that the effects of 6SAI on gut bacteria is not related with the pathogenesis of this model.