Cyclooxygenase selectivity of nonsteroidal anti-inflammatory drugs in canine blood

OBJECTIVE: To evaluate cyclooxygenase (COX) selectivity of several nonsteroidal anti-inflammatory drugs (NSAID) in canine blood in vitro. ANIMALS: 11 healthy adult male hound crosses. PROCEDURE: 9 NSAID were studied at 5 concentrations. Thromboxane B2 (TxB2) was assayed as a measure of COX-1 activity in clotted blood. Prostaglandin E2 (PGE2) was assayed as a measure of COX-2 activity in heparinized, lipopolysaccharide (LPS)-stimulated blood. All assays were competitive ELISA tests. Cyclooxygenase selectivity was expressed as a ratio of the concentration of an NSAID that inhibited 50% of the activity (IC50) of COX-1 to the IC50 of COX-2. A separate ratio of the concentration that inhibited 80% of COX activity (IC80) was also determined. A ratio of < 1.0 indicated selectivity for COX-1, whereas a ratio of > 1.0 indicated COX-2 selectivity. RESULTS: Ketoprofen, aspirin, and etodolac were COX-1 selective. Piroxicam, meloxicam, and carprofen had COX-2 selectivity. The IC50 and IC80 values were similar for most NSAID. CONCLUSIONS: This methodology provides repeatable data from individual dogs and is comparable to results of previous in vitro and ex vivo models. Findings are also consistent with those of canine studies performed in vivo, suggesting that this is a viable in vitro assessment of the COX selectivity of NSAID in dogs.     

Comparison of individual and pooled sampling methods for detecting bacterial pathogens of fish.

Examination of finfish populations for viral and bacterial pathogens is an important component of fish disease control programs worldwide. Two methods are commonly used for collecting tissue samples for bacteriological culture, the currently accepted standards for detection of bacterial fish pathogens. The method specified in the Office International des Epizooties Manual of Diagnostic Tests for Aquatic Animals permits combining renal and splenic tissues from as many as 5 fish into pooled samples. The American Fisheries Society (AFS) Blue Book/US Fish and Wildlife Service (USFWS) Inspection Manual specifies the use of a bacteriological loop for collecting samples from the kidney of individual fish. An alternative would be to more fully utilize the pooled samples taken for virology. If implemented, this approach would provide substantial savings in labor and materials. To compare the relative performance of the AFS/USFWS method and this alternative approach, cultures of Yersinia ruckeri were used to establish low-level infections in groups of rainbow trout (Oncorhynchus mykiss) that were sampled by both methods. Yersinia ruckeri was cultured from 22 of 37 groups by at least 1 method. The loop method yielded 18 positive groups, with 1 group positive in the loop samples but negative in the pooled samples. The pooled samples produced 21 positive groups, with 4 groups positive in the pooled samples but negative in the loop samples. There was statistically significant agreement (Spearman coefficient 0.80, P < 0.001) in the relative ability of the 2 sampling methods to permit detection of low-level bacterial infections of rainbow trout.     

Growth-promotant implants: managing the tools.

Great contemplation, conversation, and controversy have surrounded the use of growth-promotant implants since their inception in the 1950s. Since the very beginning, the purpose of growth promotants has been to enhance production efficiency, reduce the cost of production, and improve profitability. Changes in our understanding of the physiologic mechanisms involved in growth promotion have not altered this fundamental purpose. With enhanced knowledge of the impact of various compounds and doses on different classes of animals, and with the introduction of numerous products providing those compounds and doses, planning implant programs has become difficult. However, the net return from a well-designed implant program may mean the difference between profit and loss on a given set of cattle.     

Fracture toughness of bovine claw horn from cattle with and without vertical fissures

The study was undertaken to determine whether the claw horn from cows suffering from vertical fissures (sandcracks) is weaker with regard to fracture formation than claw horn from cows without vertical fissures. Fracture toughness was determined using a composite testing procedure previously developed for use in equine hoof horn. Twenty cows with vertical fissures of the lateral front claw were compared with 20 case controls. Due to the calibration technique needed as part of the testing method results were obtained for only five animals in each group; cows with and without vertical fissures had median J-integrals of 8182J/m(2) and 8483J/m(2), respectively, but the difference was not statistically significant. Although the numbers are small it is suggested that since no difference existed in the fracture toughness of the claw horn from the two groups of cattle, vertical fissure formation is not directly dependent on the biomechanical property of the horn itself.     

How the brain translates money into force: a neuroimaging study of subliminal motivation

Unconscious motivation in humans is often inferred but rarely demonstrated empirically. We imaged motivational processes, implemented in a paradigm that varied the amount and reportability of monetary rewards for which subjects exerted physical effort. We show that, even when subjects cannot report how much money is at stake, they nevertheless deploy more force for higher amounts. Such a motivational effect is underpinned by engagement of a specific basal forebrain region. Our findings thus reveal this region as a key node in brain circuitry that enables expected rewards to energize behavior, without the need for the subjects;awareness.     

Birthweight determines intestinal microvasculature development and alters endothelial nitric oxide synthase density in young piglets

Blood supply to enterocytes dictates intestinal health and nutrient absorption. These two aspects are impaired in low birthweight (LBW) piglets, but whether the perfusion to intestinal tissues is implicated as well is still unknown. Thus, structural changes in the microvasculature of LBW and normal birthweight (NBW) piglets were investigated during early postnatal development. Additionally, the presence of endothelial nitric oxide synthase (eNOS) in the intestinal mucosa was assessed given its important role to assure perfusion. A total of 22 pigs (11 LBW and 11 NBW) were sacrificed at days 0, 3, 8 and 19 of life. Body weight and intestinal length were recorded and a piece of the small intestine was sampled for immunohistochemical analysis of von Willebrand Factor (vWF, an endothelial cell marker) and eNOS. LBW piglets had a relatively (to body weight) longer intestine than their NBW counterparts. Age did not affect microvasculature, which was more abundant (85% larger vWF-positive area) in NBW than LBW pigs. However, an interaction age*BW was observed for eNOS-IR, showing that eNOS presence peaked in NBW piglets on the first day of life and subsequently decreased. This pattern was not observed in LBW piglets. The less abundant intestinal endothelial mass and the different pattern of eNOS expression observed in LBW piglets suggests microcirculation as a contributing factor in the impaired digestive functioning and gut health of LBW pigs. However, revealing whether the origin of this alteration is prenatal or postnatal, for example due to a lower milk intake, needs further study.     

The effects of inbreeding on performance traits of adult Pacific oysters (Crassostrea gigas)

Understanding the effects of inbreeding is critical to the long-term viability of shellfish breeding programs, especially as breeders attempt to develop selected lines in hatcheries with small effective population sizes. Inbreeding depression in shellfish is well documented among the offspring of selfed individuals and full-sib crosses. This study was conducted to determine if crossing more distantly related parents would result in measurable inbreeding depression of performance traits in adult Crassostrea gigas raised in a commercial intertidal growing environment. Families were created with expected inbreeding coefficients (F) of 0, 0.0625, and 0.203. Average family yield, individual growth rate, and survival were recorded after the first and second growing seasons. Significant inbreeding depression in yield, individual growth rate and survival was observed after the first growing season in families with F=0.203 (P<0.0001), but not in families with F=0.0625 (P>0.058). After two growing seasons, significant inbreeding depression of yield and individual growth rate was observed in families with F=0.0625 (P<0.01) and F=0.203 (P<0.001). Significant depression of survival at harvest was observed only in families with F=0.203 (P=0.009). These results emphasize the importance of maintaining pedigree records in shellfish breeding programs to help avoid the deleterious effects of inbreeding depression, even among crosses of distantly related parents.