Effects of a 98% solution of glycerol or sterilization with ethylene oxide on FeLV in bone allografts and effects on bone incorporation of allografts in cats

OBJECTIVES: To compare virucidal effects and bone incorporation properties of cortical bone allografts transplanted into specific-pathogen-free (SPF) cats. Allografts consisted of untreated bone from a SPF cat (negative-control group) and bone from 5 FeLV-infected cats that was subjected to sterilization with ethylene oxide (ETO), preservation with glycerol, or no treatment (positive-control group). SAMPLE POPULATION: Bones from the aforementioned groups and twenty 8-week-old SPF cats (5 cats/group) implanted with an allograft from 1 of the aforementioned groups. PROCEDURE: After implantation, blood samples were collected weekly to monitor FeLV p27 antigen and antibody titers. Quantification of FeLV provirus was performed on blood samples at weeks 0, 4, and 8 and donor bone samples at time of implantation. Cats were euthanatized 8 weeks after transplantation, and graft sites were evaluated. RESULTS: All results for negative-control cats were negative. All ETO group cats had negative results for antigen and provirus in blood, whereas 1 cat had a low antibody titer. Although 3 ETO-treated allografts were positive for provirus, the DNA appeared denatured. One cat in the glycerol group had positive results for all tests in blood samples. All glycerol-preserved allografts were positive when tested for provirus. All results for positive-control group cats were positive. Differences in incorporation of bone grafts were not observed. CONCLUSIONS AND CLINICAL RELEVANCE: Glycerol preservation of FeLV-infected bone allografts did not eliminate transmission of retrovirus to recipients. In contrast, ETO sterilization appeared to denature DNA and prevent infection. Treatments did not affect incorporation of bone grafts in young cats.     

The first European congress on agricultural and food ethics and follow-up workshop on ethics and food biotechnology: A US perspective

The first European Congress on Agriculturaland Food Ethics was held at Wageningen University andResearch Center (WUR), Wageningen, The Netherlands, March 4–6, 1999. This was the inaugural conference forthe newly forming European Society for Agricultural andFood Ethics – EUR-SAFE – and around two hundredpeople from across Europe (and a handful of NorthAmericans) participated. Following theCongress/conference, a small (16 people), two-dayworkshop funded in part by the US National ScienceFoundation focused on similarities and differencesbetween the US and the EU regarding publicdiscourse/debate on food biotechnology. A briefoverview of the Congress and the follow-up workshopsuggests what lessons AFHVS and ASFS might learn fromEuropean experience of agricultural and food ethics.     

Biogenetic studies in Syringa vulgaris L.: bioconversion of (18)O(2H)-labeled precursors into lilac aldehydes and lilac alcohols

Syringa vulgaris L. inflorescences, petals, and chloroplasts, isolated from lilac flower petals, were fed with aqueous solutions of (18)O-labeled linalool and [5,5-(2)H(2)]-deoxy-d-xylose (DOX). The chloroplasts of lilac flower petals were isolated after feeding experiments with labeled precursors. Volatiles from the chloroplasts were extracted by stir bar sorptive extraction (SBSE) and analyzed using enantioselective multidimensional gas chromatography-mass spectrometry (enantio-MDGC-MS). Feeding experiments with DOX indicate that the novel mevalonate-independent 1-deoxy-d-xylose 5-phosphate/2C-methyl-d-erythritol 4-phosphate (DOX/MEP) is the decisive pathway of lilac aldehyde and lilac alcohol, respectively. Bioconversion of [(18)O]linalool into lilac aldehyde and lilac alcohol during in vivo feeding experiments was monitored, and the metabolic pathways are discussed.     

Biotechnology,ethics, and the structure of agriculture

The “new” agricultural biotechnologies are presently high-priority items on the national research agenda. The promise of increased efficiency and productivity resulting from products and processes derived from biotech is thought to justify the commitment to R&D. Nevertheless, critics challenge the environmental safety as well as political-economic consequences of particular products of biotech, notably, ice-nucleating bacteria and the bovine growth hormone. In this paper the critics' arguments are analyzed in explicitly ethical terms, and assessed as to their relative merits. In some cases, a principle of “do no foreseeable harm” as well as a clear determination of likely harms would force us to conclude that research, development, and diffusion of a product or process derived from biotechnology is ethically wrong. In all cases, one conclusion that can be reached is that everyone involved in research, development, marketing and adoption of biotech products is responsible for the results of their actions; thus, each individual has a responsibility to consider a broader range of values and goals that effect and are effected by the biotechnology effort.     

Effect of temperature and relative humidity on the stability of infectious porcine reproductive and respiratory syndrome virus in aerosols

The objective of this experiment was to describe the stability of airborne infectious porcine reproductive and respiratory syndrome virus (PRRSV) as a function of temperature and relative humidity. A cloud of infectious PRRSV was aerosolized using 24-jet Collison nebulizer into a dynamic aerosol toroid (DAT) maintained at a specific temperature and relative humidity. The PRRSV cloud within the DAT was sampled repeatedly over time using SKC BioSampler impingers and the total viral RNA (RT-PCR) and concentration of infectious PRRSV (TCID50) in the air samples was determined. As measured by quantitative RT-PCR, PRRSV RNA was stable under the conditions evaluated in this study. Thus, a comparison of viral RNA and Rhodamine B dye, a physical tracer, found no significant difference in the slopes of the lines. Titers of infectious virus were plotted by time and the half-life (T1/2) of infectious PRRSV was calculated using linear regression analysis. An analysis of the results showed that aerosolized PRRSV was more stable at lower temperatures and/or lower relative humidity, but temperature had a greater effect on the T1/2 of PRRSV than relative humidity. Based on these results, an equation was derived to predict the T1/2 of infectious airborne PRRSV for any combination of environmental temperature and relative humidity.     

Cortisol Response in Healthy and Diseased Dogs after Stimulation with a Depot Formulation of Synthetic ACTH

Background

The ACTH stimulation test is used to evaluate the adrenocortical reserve. Recently, the availability of the synthetic ACTH formulation was limited, causing major problems in clinical practice.

Objectives

The objective of this study was to evaluate poststimulation peak cortisol concentrations and the duration of the stimulatory effect of a depot ACTH preparation in dogs.

Animals

Twenty‐two healthy dogs, 10 dogs with suspected hypoadrenocorticism (HA) and 15 dogs with suspected hyperadrenocorticism (HC).

Methods

Prospective study. An ACTH stimulation test using a synthetic depot tetracosactide, administered intramuscularly (5 μg/kg or at least 0.1 mL) was performed. Blood samples for determination of cortisol were taken immediately before and 1, 2, 3, 4, 6, and 24 hours after stimulation.

Results

Peak cortisol concentrations were reached after 2–4 hours in all dogs. Cortisol concentrations 1 hour after stimulation were >9 μg/dL in all healthy dogs and >5 μg/dL in all dogs in which HA was excluded. None of the dogs with HA showed a cortisol‐increase above the detection‐limit of the assay. After 6 hours, cortisol concentrations had decreased in the healthy and HC group and were back to baseline after 24 hours.

Conclusions and Clinical Importance

The depot formulation can be used in place of the short‐acting ACTH to evaluate the adrenocortical reserve. Blood for peak cortisol concentrations should be drawn 3 hours after stimulation in cases in which HC is suspected; in HA‐suspected cases, blood sampling can take place after 1 hour. As the stimulatory effect is gone after 24 hours, interference with other hormonal tests is unlikely after that time.     

Stratospheric Nitric Oxide: Measurements during Daytime and Sunset

Measurements of the temporal variation in the stratospheric nitric oxide concentration covering a time period from 11:00 to 20:30 local time show the effect of solar ultraviolet sunset. The experimental results strongly support the theorized role of nitric oxide as a catalyst in the destruction of ozone and its importance in the stratospheric ozone balance.     

Ultrastructural changes in articular cartilages of immature beagle dogs dosed with difloxacin, a fluoroquinolone.

The ultrastructural features of quinolone-induced arthropathy were studied in the humeral and femoral heads of nine skeletally immature Beagle dogs (3 months old) that were dosed orally with difloxacin at 300 mg/kg body weight and euthanatized 24, 36, or 48 hours later in groups of three. Three age-matched dogs were given a placebo and euthanatized after 48 hours. Mitochondria in chondrocytes had significantly greater cross-sectional areas (P less than 0.05) in electron micrographs from dogs euthanatized after 48 hours of treatment than did those in other groups. There was also a significantly greater percentage of chondrocytes with swollen mitochondria in treated dogs than in the controls (P less than 0.05). These changes preceded the necrosis observed in some chondrocytes in the dogs of the 48-hour group. Disruption of extracellular matrix was first observed in the pericellular matrix of necrotic chondrocytes, indicating that this change was secondary to the changes in chondrocytes. Fissures within cartilages apparently resulted from the loss of the normal association of proteoglycans with collagen fibrils.