The conventional forelimb grip strength test is a widely used method to assess skeletal muscle function in rodents; in this study, we modified this method to improve its variability and consistency. The modified test had lower variability among trials and days than the conventional test in young C57BL6 mice, especially by improving the variabilities in male. The modified test was more sensitive than the conventional test to detect a difference in motor function between female and male mice, or between young and old male mice. When the modified test was performed on male mice during the aging process, reduction of grip strength manifested between 18 and 24 months of age at the group level and at the individual level. The modified test was similar to the conventional test in detecting skeletal muscle dysfunction in young male dystrophic mice. Thus, the modified forelimb grip strength test, with its improved validity and reliability may be an ideal substitute for the conventional method.

Telomerase activity can be detected in exfoliated cells in urine from patients with bladder cancer, and measurement of this activity appears to be more sensitive in detecting the presence of cancer than standard urine cytologic examination. These findings suggest that measuring telomerase activity in exfoliated cells would be useful in the diagnosis and follow-up of patients with bladder cancer, a possibility that warrants further study.

Background-We investigated the possibility that a frequent trigger action might play a role in the development of persistent atrial fibrillation (PeAF) and the presence of a substrate. Methods and Results-In 263 consecutive patients who underwent catheter ablation (CA) for PeAF, electric cardioversion was performed at the beginning of the procedure to determine the presence or absence of an immediate recurrence of AF (IRAF).We defined an IRAF as a reproducible AF recurrence within 90 s after restoration of sinus rhythm by electric cardioversion.We performed a meanϮSD of 1.3Ϯ0.5 sessions of CA, including pulmonary vein isolation and ablation of the premature atrial contractions that triggered the IRAF (IRAF triggers), and observed the patients for 17 (10 -27) months. An IRAF was observed in 70 patients (27%), but we could not ablate the IRAF triggers in 16 (23%) of these IRAF patients. The recurrence rate of PeAF was higher in patients with an unsuccessful IRAF trigger ablation than in those with successful IRAF trigger ablation (63% versus 11%; PϽ0.001). A multivariable analysis also revealed that an unsuccessful IRAF trigger ablation was 1 of the independent predictors of recurrent PeAF (odds ratio, 10.9; 95% CI, 3.4 -36.7). Conclusions-In the PeAF patients with an IRAF, successful elimination of the IRAF triggers, in addition to pulmonary vein isolation, resulted in a successful CA. These results imply that such triggers play a major role in the AF persistence in these PeAF patients. (Circ Arrhythm Electrophysiol. 2012;5:295-301.)

Binding properties of lignin peroxidase (LiP) from the basidiomycete Phanerochaete chrysosporium against a synthetic lignin (dehydrogenated polymerizate, DHP) were studied with a resonant mirror biosensor. Among several ligninolytic enzymes, only LiP specifically binds to DHP. Kinetic analysis revealed that the binding was reversible, and that the dissociation equilibrium constant was 330 M. The LiP-DHP interaction was controlled by the ionization group with a pK a of 5.3, strongly suggesting that a specific amino acid residue plays a role in lignin binding. A oneelectron transfer from DHP to oxidized intermediates LiP compounds I and II (LiPI and LiPII) was characterized by using a stopped-f low technique, showing that binding interactions of DHP with LiPI and LiPII led to saturation kinetics. The dissociation equilibrium constants for LiPI-DHP and LiPII-DHP interactions were calculated to be 350 and 250 M, and the first-order rate constants for electron transfer from DHP to LiPI and to LiPII were calculated to be 46 and 16 s ؊1 , respectively. These kinetic and spectral studies strongly suggest that LiP is capable of oxidizing lignin directly at the protein surface by a long-range electron transfer process. A close look at the crystal structure suggested that LiP possesses His-239 as a possible lignin-binding site on the surface, which is linked to Asp-238. This Asp residue is hydrogen-bonded to the proximal His-176. This HisAsp⅐⅐⅐proximal-His motif would be a possible electron transfer route to oxidize polymeric lignin.Lignin is the most abundant renewable aromatic polymer and is known as one of the most recalcitrant biomaterials on earth (1, 2). Its degradation plays a key role in the carbon cycle of the biosphere (2-7). Only white-rot basidiomycetes are responsible for the complete mineralization of this polymer. Phanerochaete chrysosporium, the best studied white-rot fungus, secretes two heme peroxidases, lignin peroxidase (LiP) and manganese peroxidase (MnP) under ligninolytic conditions (3-8). Thus, these enzymes have been believed to be involved in triggering lignin biodegradation. MnP oxidizes Mn II to Mn III , and the latter acts as a freely diffusible one-electron oxidizer, nonspecifically reacting with terminal organic substrates such as phenols, thiols, and lignin (3, 8 -12). This nonspecific manner is advantageous for lignin degradation because lignin is such a heterogeneous polymer.LiP is another unique heme peroxidase secreted by P. chrysosporium. It catalyzes a one-electron oxidation of nonphenolic aromatic compounds, forming the aryl cation radical (13,14), suggesting that oxidized intermediates of the enzyme possess a very high redox potential. The mechanism of LiP catalytic action on lignin is still uncertain, because it has not been clear whether LiP can oxidize lignin through a direct interaction or through radical mediation. Veratryl (3,4-dimethoxybenzyl) alcohol (VA), a preferred substrate for LiP, is synthesized de novo by P. chrysosporium under ligninolytic conditions (15). The...