Association of the intronic polymorphism rs891512 (G24943A) of the endothelial nitric oxide synthase gene with hypertension in Chilean type 2 diabetes patients.

We investigated two single nucleotide polymorphisms of the NOS3 gene in type 2 diabetic patients (n=93) and healthy non-diabetic controls (n=76) and their relationship with smoking habits, body mass index, hypertension and dyslipidemia. Results showed that eNOS polymorphism rs891512 (G24943A) is associated with hypertension in Chilean individuals (p<0.05).

Isolation and characterization of homokaryotic strains from the ligninolytic basidiomycete Ceriporiopsis subvermispora.

Genetic analyses of the lignin-degrading fungus Ceriporiopsis subvermispora is complicated by a dikaryotic nuclear condition and the absence of spore forms. Previous investigations had identified a family of closely related sequences encoding manganese peroxidase (MnP), but the relationship between genes and allelic variants could not be experimentally established. Addressing this issue, homokaryotic derivatives of C. subvermipora strain FP105752 were isolated from regenerated protoplasts. Designated CsA and CsB, their homokaryotic nature was established by polymerase chain reaction amplification and sequence analysis of the allelic variants of three MnP genes. Isoelectrofocusing revealed fewer MnP isoenzymes in filtrates of homokaryon cultures relative to the parental strain. The homokaryotic strains will simplify genetic analyses, particularly the identification of new genes.

Predicted and measured muscle forces after recoveries of differing durations following fatigue in functional electrical stimulation.

Using 31P nuclear magnetic resonance (NMR) spectroscopy, the bioenergetics of paralyzed muscles activated by functional electrical stimulation (FES) were studied in vivo during fatigue and recovery on paraplegic subjects. During the activation phase of the muscle, the muscle force was also monitored. The phosphorus metabolites were found to vary systemically during the fatigue and to recover slowly to their rest state values after cessation of FES. During fatigue, a good correlation was found between the decaying force and each of the profiles of phosphocreatine, inorganic phosphorus, and intracellular pH. A musculotendon 5 element model was proposed for the activated muscle to predict its force generation capacity. A fatigue recovery function, based on the metabolic profiles, was introduced into the model. This model allowed us to predict the force expected to be developed as a function of the time after recovery of given time durations. Validation experimental measurements of force were carried out and included recurrent fatigue tests, both in the initially unfatigued state and at various times in the postfatigue stage of the muscle. Comparison of the predicted and measured forces indicated satisfactory agreement of the results. The developed model of muscle dynamics should help to design a strategy for reducing muscle fatigue under FES.

Biochemical and genetic studies of bacteria metabolizing lignin-related compounds.

The ability of bacterial strains to metabolize lignin model compounds was studied. Strains examined were non-filamentous bacterial isolates obtained from decaying wood and the actinomycete Streptomyces viridosporus T7A. Model compounds included dimers containing either the beta-1 (1,2-diarylethane) or the beta-O-4 (arylglycerol-beta-aryl ether) type of linkage. Pseudomonas fluorescens biovar I A1 proliferated on anisoin (4,4'-dimethoxybenzoin) accumulating anisic acid temporarily. Cleavage at the beta-1 bond was also observed with crude extracts prepared from the same strain. In turn, cleavage of the beta-O-4 linkage of veratrylglycerol-beta-guaiacyl ether was detected in cultures of Pseudomonas acidovorans D3. In this case, main degradation intermediates were beta-hydroxypropioveratrone, acetoveratrone and guaiacol. S. viridosporus T7A reduced the carbonyl group of some beta-1 dimers and did not modify the beta-O-4 model compounds tested. Attempts to ascribe a catabolic character to large molecular weight extrachromosomal DNA present in some strains were unsuccessful. Gene banks of P. fluorescens biovar I A1 and P. acidovorans D3 were prepared utilizing the broad host range cosmid pLAFR1 as vector.