Manganese(II) semiquinonato and manganese(III) catecholato complexes with tridentate ligand: modeling the substrate-binding state of manganese-dependent catechol dioxygenase and reactivity with molecular oxygen.

Catecholate catwalk: Monomeric manganese(III) catecholato and manganese(II) semiquinonato complexes as the substrate-binding model of catechol dioxygenase have been synthesized and structurally characterized. The semiquinonato complex reacted with molecular oxygen to give ring-cleaved products and benzoquinone in the catalytic condition.

The efficacy of slide tracheoplasty in a growing rabbit model.

PURPOSE: Slide tracheoplasty for congenital tracheal stenosis was reported by Tsang. This procedure provides good results, but there are few studies about the tracheal growth of post-surgical condition. Recently, not only traditional posterior to anterior slide plasty but also right side to left side slide plasty was reported. We evaluated the tracheal growth after slide tracheoplasty in growing Japanese white rabbit model. METHODS: The Japanese white rabbits, weighing 1,600-2,400 g, were used for this study. One-third of the estimated length of the trachea was slantingly resected about an appropriate angle. We performed a slant, side-to-side tracheal anastomosis in two ways (slanted from the front to the back in four animals, and slanted from right to left in four animals) on growing rabbits as an animal model of slide tracheoplasty. RESULTS: All the rabbits were alive until the 10th week after surgery. There was no evidence of differential growth in any part of the circumference of the normal and anastomotic tracheas. Histologically, all tracheal lumina were completely lined with normal respiratory epithelium and normal surrounding cartilage. CONCLUSION: The results presented that these two methods did not prevent the tracheal growth and trachea did not buckle macroscopically. Both slide tracheoplasties did not interrupt the growth of trachea.

Electrochemically controlled release of alpha,beta,gamma,delta-tetrakis(4-N-methylpyridyl)porphine from layer-by-layer thin films.

The release of alpha,beta,gamma,delta-tetrakis(4-N-methylpyridyl)porphyrin (TMPyP) from layer-by-layer assembled thin films composed of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) was electrochemically controlled. The release rate of TMPyP was enhanced when a positive electrode potential (+1.2 to +1.5 V) was applied to the glassy carbon electrode on which TMPyP-loaded PAH/PAA film was coated, while the effect of lower electrode potentials (0 to +1.0 V) was negligibly small. The effect of applied potential on the release rate was more significant at pH 7.4 than in the solutions of pH 8.0 and 9.0. The electrochemically enhanced release of TMPyP was rationalized based on local pH change in the vicinity of the electrode surface, which was induced by electrolysis of H(2)O.

Carbon dioxide pneumoperitoneum prevents intraperitoneal adhesions after laparotomy in rats.

PURPOSE: The aim of this study was to assess whether carbon dioxide insufflation (CDI) pneumoperitoneum prevents intraperitoneal adhesions (IPAs). METHODS: Laparotomy was performed in 40 8-week-old Lewis rats and their bowels delivered through the wound and manipulated. The rats were divided into 4 groups, namely, those that would have laparotomy (Lp group, n = 15), Lp with CDI (Lp-CDI group, n = 15), Lp and bowel anastomosis (LpBA group, n = 5), and LpBA with CDI (LpBA-CDI group, n = 5). LpBA and LpBA-CDI group rats had 1 cm of ileum excised and end-to-end anastomosis performed. To accelerate IPA formation, all rats then had their bowels heated to 45 degrees C for 40 seconds and 0.5 mL of Lewis rat blood spilled over them. Rats in the control group (n = 5) had Lp alone without heating or blood spillage. Pneumoperitoneum involved insufflating carbon dioxide into the peritoneal cavity through a cannula at the time of final abdominal closure to create pneumoperitoneum to a pressure of 5 mm Hg. All rats had relaparotomy 10 days after surgery and IPAs were assessed blindly using an IPA severity score (IPASS: 0 = no adhesions, 1 = no serosal tears during adhesiolysis, 2 = serosal tears during adhesiolysis, 3 = bowel perforation during adhesiolysis). Only the worst IPA in each rat was scored. Rats were killed after the peritoneum and bowels were excised for histopathology. RESULTS: Pneumoperitoneum resolved in approximately 5 days. There were no associated side effects. The Lp-CDI group had significantly lower IPASS than the Lp group (0.23 +/- 0.46 vs 1.07 +/- 1.18, P < .05), and the LpBA-CDI group had significantly lower IPASS than the LpBA group (1.50 +/- 0.61 vs 2.40 +/- 0.55, P < .05). Histopathology showed pneumoperitoneum had no effect on the peritoneum or bowels. CONCLUSIONS: Our results suggest that CDI pneumoperitoneum appears to prevent IPA, especially between bowel-bowel IPA.