FIP: a novel approach to vaccination. Proceedings from the 2nd International FCoV/FIP Symposium, Glasgow, 4-7 August 2002

Feline infectious peritonitis (FIP) is a fatal disease of cats. Early attempts at vaccination have been unsuccessful, some even serving to exacerbate the disease through antibody-dependent enhancement. Replication-incompetent feline foamy virus (FFV) transducing vectors are being developed as potential vaccine agents, into which immunogenic fragments of feline coronavirus (FCoV) proteins will be inserted. To use a recombinant viral vector to express FCoV proteins, the agent chosen should be apathogenic and replication incompetent within the host following gene delivery. Spumaviruses confer several advantages over the more traditionally explored retroviral vectors. Stable helper cell line clones have been established by transfection of CRFK cells with FFV tas and assessed using beta-galactosidase assays, PCR, immunofluorescence and western blotting. The generation of infectious virions using these cell lines has been investigated using tas-deleted FFV vectors containing the enhanced green fluorescent protein (eGFP) cassette.     

A rapid confirmatory method for analyzing tetracycline antibiotics in bovine, swine, and poultry muscle tissues: matrix solid-phase dispersion with heated water as extractant followed by liquid chromatography-tandem mass spectrometry

A rapid, specific, and sensitive procedure for determining four widely used tetracycline antibiotics and three related epimers in bovine, swine, and poultry muscle tissues is presented. The method is based on the matrix solid-phase dispersion technique with heated water as the extractant followed by liquid chromatography (LC)-tandem mass spectrometry (MS) equipped with an electrospray ion source. Target compounds were extracted from tissues with 5 mL of water heated at 70 degrees C. After acidification and filtration, 100 microL of the aqueous extract was injected in the LC column. MS data acquisition was performed in the multireaction monitoring mode, selecting two precursor ion to product ion transitions for each target compound. Heated water appeared to be an excellent extractant, since the absolute recovery data ranged between 70 and 78%. The accuracy of the method was determined at three spike levels, using minocycline as a surrogate analyte, in any different kind of muscle tissues considered and varied between 88 and 109% with relative standard deviations ranging between 3 and 11%. Limits of quantification were estimated to range between 1 (chlortetracycline) and 9 ng/g (4-epioxytetracycline), based on a signal-to-noise ratio of 10, and are well below the tolerance levels set by the European Union. The effects of the extraction temperature, volume of the extractant, and washing of the material supporting the biological matrix with ethylenediamine tetraacetic disodium salt on the analyte recovery were studied.     

Effect of Weight Loss in Obese Dogs on Indicators of Renal Function or Disease

Background

Obesity is a common medical disorder in dogs, and can predispose to a number of diseases. Human obesity is a risk factor for the development and progression of chronic kidney disease.

Objectives

To investigate the possible association of weight loss on plasma and renal biomarkers of kidney health.

Animals

Thirty‐seven obese dogs that lost weight were included in the study.

Methods

Prospective observational study. Three novel biomarkers of renal functional impairment, disease, or both (homocysteine, cystatin C, and clusterin), in addition to traditional markers of chronic renal failure (serum urea and creatinine, urine specific gravity [USG], urine protein‐creatinine ratio [UPCR], and urine albumin corrected by creatinine [UAC]) before and after weight loss in dogs with naturally occurring obesity were investigated.

Results

Urea (P = .043) and USG (P = .012) were both greater after weight loss than before loss, whilst UPCR, UAC, and creatinine were less after weight loss (P = .032, P = .006, and P = .026, respectively). Homocysteine (P < .001), cystatin C (P < .001) and clusterin (P < .001) all decreased upon weight loss. Multiple linear regression analysis revealed associations between percentage weight loss (greater weight loss, more lean tissue loss; r = ?0.67, r² = 0.45, P < .001) and before‐loss plasma clusterin concentration (greater clusterin, more lean tissue loss; r = 0.48, r² = 0.23, P = .003).

Conclusion and Clinical Importance

These results suggest possible subclinical alterations in renal function in canine obesity, which improve with weight loss. Further work is required to determine the nature of these alterations and, most notably, the reason for the association between before loss plasma clusterin and subsequent lean tissue loss during weight management.

     

Nutrient solution monitoring in greenhouse cultivation employing a potentiometric electronic tongue

This work investigates the use of electronic tongues for monitoring nutrient solution compositions in closed soilless systems. This is a horticultural technique in which the nutrient solution is continuously recirculated and an automatic recomposition system maintains the concentration of the different ions in the optimum range for the plants. Electronic tongues used in this study comprised an array of potentiometric sensors and complex data processing by artificial neural networks. A first experiment was able to carry out the simultaneous inline monitoring of ammonium, potassium, sodium, chloride, and nitrate ions during the winter. In the second and third applications, done during summer, some changes were introduced in the sensor array to improve its response toward chloride ions and to incorporate phosphate in the model. This electronic tongue was validated with real greenhouse samples and was also able to detect the variations in the ion concentrations caused by an incorrect configuration of the recomposition system.     

Molecular detection of a Hepatozoon species in stray cats from a feline colony in North-eastern Spain

Within the framework of a local animal health programme, the presence of ectoparasites and haemoparasites was investigated in a colony of 25 cats in Barcelona. Diagnosis was performed both by standard parasitological procedures and molecular techniques. All cats were negative to haematozoan infection by microscopic examination of blood smears. However, Hepatozoon spp. was found in four cats as shown by amplification and sequencing of the 18S rRNA gene. Cat isolates were 100% identical to the isolate Hepatozoon spp. (Spain 2) from Southern Spain. This is the first time that Hepatozoon spp. has been identified in cats from Northern Spain.     

Changes in body composition during weight loss in obese client-owned cats: loss of lean tissue mass correlates with overall percentage of weight lost

Obesity is one of the most common medical diseases in cats, but there remains little information on success of weight loss regimes in obese client-owned cats. No information currently exists on body composition changes during weight loss in clinical cases. Twelve obese client-owned cats undertook a weight loss programme incorporating a high-protein low fat diet. Body composition was quantified by dual-energy X-ray absorptiometry, before and after weight loss. Mean (+/-standard deviation) weight loss was 27+/-6.8% of starting weight, and mean rate of weight loss was 0.8+/-0.32% per week. Mean energy allocation during weight loss was 32+/-7.0 kcal/kg target weight. Mean composition of tissue lost was 86:13:1 (fat:lean:bone mineral). The proportion of lean tissue loss was positively associated with overall percentage of weight loss (simple linear regression, r(2)=44.2%, P=0.026). Conventional weight loss programmes produce safe weight loss, but lean tissue loss is an inevitable consequence in cats that lose significant proportions of their starting body weight.     

A long-snouted predatory dinosaur from africa and the evolution of spinosaurids

Fossils discovered in Lower Cretaceous (Aptian) rocks in the Tenere Desert of central Niger provide new information about spinosaurids, a peculiar group of piscivorous theropod dinosaurs. The remains, which represent a new genus and species, reveal the extreme elongation and transverse compression of the spinosaurid snout. The postcranial bones include blade-shaped vertebral spines that form a low sail over the hips. Phylogenetic analysis suggests that the enlarged thumb claw and robust forelimb evolved during the Jurassic, before the elongated snout and other fish-eating adaptations in the skull. The close phylogenetic relationship between the new African spinosaurid and Baryonyx from Europe provides evidence of dispersal across the Tethys seaway during the Early Cretaceous.     

Impact of transgenic viral resistance on seed potato certification

It was nearly 100 years ago that the decline in quality and yield observed in potato crops was attributed to the accumulation of pathogens in seed tubers saved from one field generation to the next. As a direct result of this realization, seed potato certification programs have been initiated throughout the world. While these programs have different administrative structures and employ various methodologies, they are all dedicated to the primary goal of producing a sufficient volume of high quality seed tubers as free from disease causing organisms as possible. Viral diseases are especially problematic because they have serious economic affects and their physical and biological properties make them difficult to control. Until recently, certification programs have relied on methodologies including the use of virus-free material obtained from tissue culture, strict adherence to practices that minimize the mechanical and insect spread of virus, physical inspection of seed increase plots to identify and minimize the number of virus-infected plants, and the increase of seed materials for only a limited number of years to insure that any infected materials are “flushed out” of the system. Approximately 10 years ago, it was first observed that virus resistance can be obtained by using transformation techniques to insert viral genes into the genome of plants. Subsequently, researchers in private and public laboratories have shown that potato plants produced in this way are highly resistant or immune to several viral diseases. The effect that the deployment of these materials may have on the seed potato certification process is the subject of this paper.