Nitric oxide and cyclic nucleotides are regulators of neuronal migration in an insect embryo.

The dynamic regulation of nitric oxide synthase (NOS) activity and cGMP levels suggests a functional role in the development of nervous systems. We report evidence for a key role of the NO/cGMP signalling cascade on migration of postmitotic neurons in the enteric nervous system of the embryonic grasshopper. During embryonic development, a population of enteric neurons migrates several hundred micrometers on the surface of the midgut.

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) alters the endogenous metabolism of all-trans-retinoic acid in the rat.

2,3,7,8-Tetrachlorodibenzo- p-dioxin (TCDD) is known to influence vitamin A homeostasis. In order to investigate the mechanism behind this retinoid disruption, male Sprague-Dawley rats were exposed to TCDD at doses ranging from 0.1 to 100 micro g/kg body weight, and were killed 3 days after exposure.

Flow cytometry and its application in small animal oncology.

Flow cytometry measures multiple characteristics of single cells. The use of flow cytometry in the veterinary clinical laboratory has increased considerably during the past decade. The most common applications of flow cytometry in small animal oncology are measurement of DNA content in tumours and immunophenotyping of haematopoietic malignancies.

Simultaneous determination of ketamine and xylazine in canine plasma by liquid chromatography with ultraviolet absorbance detection.

An isocratic reversed-phase high-performance liquid chromatographic method for the simultaneous determination of ketamine and xylazine in canine plasma is described. Plasma samples (500 microl) are cleaned up via liquid-liquid extraction. The analytes and the internal standard clonidine are separated on a cyano (CN) column using a mobile phase containing acetonitrile-0.

Sensitivity of different prothrombin time assays to factor VII deficiency in canine plasma.

The factor VII sensitivity of prothrombin time (PT) in dogs was tested using five different PT reagents and a commercial PT variant. The five PT reagents were used according to manufacturers' instructions (standard test, PT([ST])) and also using a modified test instruction (modified test, PT([MT])). Plasma samples with defined factor VII levels (10-100%) were prepared by adding increasing quantities of canine factor VII deficient plasma to the pooled plasma of healthy dogs.

Bovine viral diarrhoea eradication and control programmes in Europe.

The economic impact of BVDV infections has led a number of countries in Europe to start eradication or control programmes. While in both cases the primary step is identification and elimination of persistently infected (PI) animals, the strategy applied thereafter is dependent on the density and seroprevalence of the regional cattle population. One of the first countries to design and implement an eradication programme was Sweden in 1993, a country with a relatively low cattle density and no vaccination.

A high resolution physical and RH map of pig chromosome 6q1.2 and comparative analysis with human chromosome 19q13.1.

Background: The generation of BAC/PAC contigs in targeted genome regions is a powerful method to establish high-resolution physical maps. In domestic animal species the generation of such contigs is typically initiated with the screening of libraries with probes derived from human genes that are expected to be located in the region of interest by comparative mapping. However, in many instances the available gene-derived probes are too far apart to allow the cloning of BAC/PAC contigs larger than a few hundred kb.

Specific order in the appearance of protein tyrosine phosphorylation patterns is functionally coordinated with dog sperm hyperactivation and capacitation.

The aims of the present study were to characterize a slow capacitation system that records initial changes in the sperm membrane state, and, using a canine model, to order the specific protein tyrosine phosphorylation signaling in the sequence of capacitational events and to associate them with hyperactivated motility. Dog sperm washed through Percoll were incubated in complete bicarbonate Tyrode medium for 6 hours in 5% CO(2). Capacitation was evaluated using chlortetracycline staining.

Altered spontaneous discharge rate and pattern of basal ganglia output neurons in the circling (ci2) rat mutant.

The circling rat is an autosomal recessive mutant (homozygous ci2/ci2) characterized by lateralized rotational behavior, locomotor hyperactivity, ataxia, stereotypic head movements, and deafness. Previous neurochemical investigations showed that ci2 rats of both genders have a lower tissue content of dopamine in the striatum ipsilateral to the preferred direction of circling. For further evaluation as to whether this striatal imbalance has functional consequences within basal ganglia structures, the spontaneous extracellular single unit activity of GABAergic neurons located in the striatum and, downstream to the dopaminergic nigrostriatal system, the substantia nigra pars reticulata (SNr) was recorded bilaterally in anesthetized ci2 rats.

Mapping and microsatellite marker development for the porcine leukemia inhibitory factor receptor (LIFR) and epidermal growth factor receptor (EGFR) genes.

Leukemia inhibitory factor receptor (LIFR), epidermal growth factor receptor (EGFR), and their respective ligands have been implicated in regulating growth and development of the early pig conceptus. We isolated a PAC clone containing the porcine gene for LIFR and a BAC clone with the porcine EGFR gene, respectively. On each of these clones one microsatellite marker was identified by sequencing a collection of subclones.

Molecular characterization of the porcine gene CAPNS1 encoding the small subunit 1 of calpain on SSC6q1.1-->q1.2.

The CAPNS1 gene encodes the small subunit of the calpain proteases. Cloning and characterization of the porcine CAPNS1 gene revealed a highly conserved organization with respect to other mammalian CAPNS1 orthologs. The porcine gene consists of 11 exons spanning approximately 7.

Reverse transcription-polymerase chain reaction assay for species-specific detection of bovine central nervous system tissue in meat and meat products.

This paper reports the development of a reverse transcription-polymerase chain reaction (RT-PCR) assay coupled with restriction fragment length polymorphism (RFLP) analysis to specifically detect the glial fibrillary acidic protein (GFAP) mRNA of bovine central nervous system (CNS) tissue in minced meat and meat products. RNA extracted from bovine brain tissue and brain tissue from other mammals yielded a 168-bp CNS-specific signal after RT-PCR. The species specificity of the assay can be obtained by subsequent RFLP analysis of the amplified RT-PCR product.

Blood vessels of the rat tail: a histological re-examination with respect to blood vessel puncture methods.

The rat tail vascularization is histologically re-examined especially with respect to blood sampling and vascular-injection methods. The terminal third of the tail is recommended for blood vessel puncturing. In this segment, the arteries and veins are most prominent, since the structures of the musculo-skeletal system diminish towards the tip of the tail.

Species-specific usage of sleeping sites in two sympatric mouse lemur species (Microcebus murinus and M. ravelobensis) in northwestern Madagascar.

We investigated the sleeping site ecology of two sympatric mouse lemur species (Microcebus murinus and M. ravelobensis) in northwestern Madagascar during the second half of the dry season with respect to the type, quality, and usage pattern of the sleeping sites, as well as to social sleeping habits and response to potential threats. The type and quality of the sleeping sites differed between the two species.

Chromatographic analysis of endogenous retinoids in tissues and serum.

We present a reliable, highly sensitive, and versatile method for the simultaneous determination of endogenous polar (acidic) and apolar (retinol, retinal, and retinyl esters) retinoids in various biological matrices. Following a single liquid extraction of retinoids from tissues or plasma with isopropanol, polar retinoids are separated from apolar retinoids and neutral lipids via automated solid-phase extraction using an aminopropyl phase. After vacuum concentration to dryness and reconstitution of the residue in appropriate solvents, the obtained fractions are injected onto two different high-performance liquid chromatography (HPLC)-systems.

Seeking mathematical strategies in sperm function analysis: between scylla and charybdis?

During the last decades, essential progresses in reproductive biotechnology were achieved, implying development of special spermatological techniques. The major problem was to set up simple, rapid, precise and adequate evaluation methods. The key aspect to be considered in all assays of sperm fertilizing function is capacitation.

The effects of different rack systems on the breeding performance of DBA/2 mice.

Housing systems for laboratory animals have been developed over a long time. Micro-environmental systems such as positive, individually ventilated caging systems and forced-air-ventilated systems are increasingly used by many researchers to reduce cross contamination between cages. There have been many investigations of the impact of these systems on the health of animals, the light intensity, the relative humidity and temperature of cages, the concentration of ammonia and CO(2), and other factors in the cages.

A glutamine to proline exchange at amino acid residue 1098 in sucrase causes a temperature-sensitive arrest of sucrase-isomaltase in the endoplasmic reticulum and cis-Golgi.

A striking feature of phenotype II in congenital sucrase-isomaltase deficiency is the retention of the brush border protein sucrase-isomaltase (SI) in the cis-Golgi. This transport block is the consequence of a glutamine to proline substitution at amino acid residue 1098 of the sucrase subunit. Here we provide unequivocal biochemical and confocal data to show that the SI(Q/P) mutant reveals characteristics of a temperature-sensitive mutant.

Influence of platelet count, acetylsalicylic acid, von Willebrand's disease, coagulopathies, and haematocrit on results obtained using a platelet function analyser in dogs.

The platelet function analyser PFA-100 aspirates blood in vitro from a sample reservoir in disposable test cartridges through a microscopic aperture cut into a biologically active membrane at the end of a capillary. In different cartridges the membrane is coated with collagen and adenosine diphosphate (ADP) or collagen and epinephrine (adrenaline) inducing a platelet plug and closure of the aperture. The closure time and total volume of blood flow through the capillary until closure of its aperture were measured.

Fate of lactadherin P47 during post-testicular maturation and capacitation of boar spermatozoa.

Polyclonal avian antibody was used partially to characterize the pig sperm lactadherin P47. P47 is a mosaic protein, composed of two epidermal growth factor (EGF)-like domains and two C1/C2 domains. P47 is homologous to the bovine mammary gland protein MGP 53/57 and mouse milk fat globule protein.

Effect of dietary vitamin E supplementation on the shelf life of cured pork sausage.

This study examined the shelf life of cured sausage under different packaging conditions from vitamin E supplemented pigs. One group (n=6) of crossbred pigs received a normal fattening diet containing 20 ppm α-tocopherol for 39 days before slaughter. Another group was fed a diet containing 410 ppm α-tocopherol during the same period.