We investigated the role of limitations in aerobic metabolism, glycolysis, and membrane excitability for development of high-frequency fatigue in isolated rat soleus muscle. Muscles mounted on force transducers were incubated in buffer bubbled with 5% CO(2) and either 95% O(2) (oxygenated) or 95% N(2) (anoxic) and stimulated at 60 Hz continuously for 30-120 s or intermittently for 120 s. Cyanid...

Interstitial K(+) concentrations were measured during one-legged knee-extensor exercise by use of microdialysis with probes inserted in the vastus lateralis muscle of the subjects. K(+) in the dialysate was measured either by flame photometry or a K(+)-sensitive electrode placed in the perfusion outlet. The correction for fractional K(+) recovery was based on the assumption of identical fractio...

Residue identification in a pharmaceutical manufacturing environment involves; the cleaner, primary ingredients, excipients, decomposition products, and preservatives. This document is intended to help with the cleaner residue identification. Residue detection method selection for cleaners can involve specific methods for specific cleaner ingredients such as; high performance liquid chromatogra...

A agência brasileira que regulamenta a produção e comercialização de álcool combustível estabelece que a concentração de sódio deve ser determinada usando a fotometria de chama e curva analítica construída com soluções padrão preparadas em uma matriz que se assemelhe às amostras. Todavia, essa metodologia pode produzir resultados inexatos porque o álcool combustível apresenta uma variabilidade ...

Conventional gravimetric (weight loss) calibration of jet nebulizers overestimates their aerosol output by up to 80% due to unaccounted evaporative loss. We examined two methods of measuring true aerosol output from jet nebulizers. A new adaptation of a widely available clinical assay for lithium (determined by flame photometry, LiCl method) was compared to an existing electrochemical method ba...

The passive permeability properties of Rickettsia mooseri to both inorganic and organic solutes have been examined. Visual observations by phase-contrast microscopy of rickettsiae in macerated yolk sacs taken directly from heavily infected eggs revealed plasmolysis with hypertonic NaCl and KCl as well as with sucrose solutions. In contrast, similar visual studies of rickettsiae which had been s...

Arginase, a manganese-dependent enzyme that widely distributed in almost all creatures, is a urea cycle enzyme that catalyzes the hydrolysis of L-arginine to generate L-ornithine and urea. Compared with the well-studied arginases from animals and yeast, only a few eubacterial arginases have been characterized, such as those from H. pylori and B. anthracis. However, these enzymes used for argina...

Stress causes an increase in cortisol and amylase. Recurrent aphthous stomatitis (RAS) results due to a multitude of causes, amongst which stress is one of the most important. Aim of the study was to estimate the level of stress, serum cortisol, salivary cortisol, amylase and electrolytes in subjects with RAS. 34 subjects with RAS (cases) were compared with 34 controls. Stress was measured usin...

Administration of oral contraceptive (OC) has been associated with body fluid retention and in high doses over a long period, promotes hypertension. This present investigation tests the hypothesis that the dietary calcium supplementation increases salt and water excretion in OC (norgestre/ethinylestradiol) treated 32 female albino rats randomly distributed into four (1-4) groups of 8 rats each:...

Ouabain-sensitive (OS) and -resistant (OR) Rb(+) influx was examined in three sublines of U937 cells to compare alterations of K(+) channel permeability and the Na(+),K(+)-ATPase pump leading to the shift in ion and water balance during apoptosis induced by 0.2 and 1microM staurosporine (STS) for 4-5 h. Cell K(+), Rb(+), Na(+) and Cl(-) content was determined by flame photometry and (36)Cl dist...