Urethral pressure profile and hemodynamic effects of phenoxybenzamine and prazosin in non-sedated male beagle dogs

Prazosin is a readily available alpha-adrenergic antagonist that may be useful in the management of functional urethral obstruction in companion animals. This study used urethral pressure profilometry to evaluate the urethral effects of prazosin and phenoxybenzamine in healthy, non-sedated, male Beagle dogs. Heart rate, indirect systolic, diastolic and mean arterial blood pressures were measured, and saline perfusion urethral pressure profilometry was performed at 0, 10, 20, and 40 min following intravenous administration of prazosin (0.025 mg/kg), phenoxybenzamine (0.2 mg/kg), or placebo. Maximal urethral pressure, maximal urethral closure pressure, post peak nadir, and all blood pressure parameters decreased significantly at nearly all treatment intervals following administration of prazosin compared with placebo. Less consistently significant reductions were observed following phenoxybenzamine administration. Maximal decreases in urethral pressure parameters were observed 20 min following the injection of prazosin; maximal blood pressure decreases were evident by 10 min post- injection. In this non-sedated dog model, urethral pressure profilometry was a sensitive method of detecting urethral effects of alpha antagonists. Repeatable reductions in urethral pressure measurements were observed, with prazosin effecting more consistently significant changes than phenoxybenzamine. Significant decreases in systolic, diastolic, and mean arterial blood pressures were seen with prazosin, but not phenoxybenzamine or placebo. Further study of selective alpha-1 antagonists in dogs is needed to determine appropriate oral dosing protocols that will produce maximal urethral effects with minimal hemodynamic effects, and to demonstrate clinical efficacy in dogs with functional urethral obstruction.     

Lateral variations in Compressional/Shear velocities at the base of the mantle

Observations of core-diffracted P (Pdiff) and SH (SHdiff) waves recorded by the Missouri-to-Massachusetts (MOMA) seismic array show that the ratio of compressional (P) seismic velocities to horizontal shear (SH) velocities at the base of the mantle changes abruptly from beneath the mid-Pacific (VP/VS = 1.88, also the value predicted by reference Earth models) to beneath Alaska (VP/VS = 1.83). This change signifies a sudden lateral variation in material properties that may have a mineralogical or textural origin. A textural change could be a result of shear stresses induced during the arrival at the core of ancient lithosphere from the northern Pacific paleotrench.     

Bestimmung der Harnstoffabbaurate in Land- und Unterwasserböden nach verschiedenen Methoden

Determination of urease activity by two different methods in some soils and underwater soils Two methods differing in microbial activity during incubation with urea were used for the determination of urease activity. The results obtained showed a better relationship with natural conditions such as pH, organic substance-, or clay content, if the microbial activity was not inhibited during incubation. This effect was found to be particularly pronounced in underwater soils, where addition of a bacteriostatic substance (toluene) resulted in practically uniform values that reflected neither bacterial nor nutrient status.     

Modelling relative abundance of Oligoryzomys flavescens,an Orthohantavirus reservoir,in an endemic hantavirus pulmonary syndrome zone

Hantavirus pulmonary syndrome (HPS) is a zoonotic emerging infectious disease caused by New World orthohantaviruses (family Hantaviridae) hosted by rodents of the family Cricetidae. In Argentina, one of its main hosts is the sigmodontine rodent Oligoryzomys flavescens, a widely distributed mouse of the Pampas, Delta and Espinal ecoregions of central-east Argentina. Because the abundance of the reservoir and its proportion in the rodent community affects both virus prevalence and human exposure risk, its estimation throughout its known geographical distribution is of key importance for the design of public health strategies to prevent HPS. The aim of this study was therefore to model the relative abundance of O. flavescens in most of the Pampas ecoregion within Buenos Aires Province, Argentina, where hantavirus pulmonary syndrome is endemic. To do this we used owl-pellet samples collected between 2006 and 2008 from 51 sites distributed throughout most of Buenos Aires province. Mammalian prey in each pellet was identified to the lowest possible taxonomic level by examination of the skulls, dentaries and molars. We modelled the frequency of O. flavescens found in each sample as a function of climatic, environmental, and topographic data of each site. The two best models were applied to a Geo referential Information System to build maps of estimated frequency (as a proxy of relative abundance) within Buenos Aires province. Estimated relative abundance of O. flavescens in Buenos Aires province was significantly associated with annual mean temperature, annual precipitation and presence of freshwater bodies, and varied among sub-regions, with the Inland and Rolling Pampas being the regions with highest frequencies. Knowing in which areas O. flavescens abundance is expected to be higher can be used to concentrate limited sanitary efforts in those areas that are most needed in order to reduce transmission and increase detection.     

Extraction and Activation of Wheat Polyphenol Oxidase by Detergents: Biochemistry and Applications

Polyphenol oxidases (PPOs) from several plant species, including wheat, have been implicated in undesirable brown discolorations of food products. It has been demonstrated that these enzymes are often present in a latent form or are membrane‐associated, necessitating detergent or other treatments to obtain fully active preparations. Here, the influence of different detergents on wheat meal and flour PPOs was investigated. Extraction in presence of 50 mM SDS led to a 5‐ to 15‐fold increase in PPO activity, making quantitative assays in flour from low‐PPO lines more robust. Among a series of additional nonionic, anionic, and cationic detergents tested, only n ‐lauroylsarcosine increased extractable PPO activity to a degree comparable to that of SDS. Additional experiments suggested that a large fraction of wheat meal PPOs may be membrane‐associated and that SDS is able to activate PPOs extracted from high‐activity but not from low‐activity wheat lines. PPO activities assayed after SDS extraction of meal and flour were highly correlated with each other and with activity determined in whole (intact) kernels in absence of SDS. Correlation coefficients between PPO activities measured with all these methods and noodle brightness were about equal, indicating that activities assayed after SDS extraction are useful for germplasm screening and quality prediction.