Exploring the genetics underpinning dynamic laryngeal collapse associated with poll flexion in Norwegian-Swedish Coldblooded Trotter racehorses.

BACKGROUND: Dynamic laryngeal collapse (DLC) associated with poll flexion is the most common disorder of the upper respiratory tract (URT) in the Norwegian-Swedish Coldblooded Trotter (NSCT). The disorder, which has also been diagnosed in other breeds of trotters and gaited horses, appears to be related to anatomic phenotypes and only occurs during poll flexion when the horse is exercised 'on the bit'. OBJECTIVES: Identify genomic regions associated with DLC in the NSCT by combining a rigorous phenotyping protocol with genomic data from a high-density equine genotyping array. STUDY DESIGN: Prospective case/control study. METHODS: High-speed treadmill endoscopy was used to phenotype horses (n = 61) for DLC, distinguishing between cases and controls. Genome-wide association (GWA) analysis of DLC status was then performed using a principal component approach (PCA) with haplotype analyses subsequently performed for regions containing single-nucleotide polymorphisms (SNPs) above the suggestive genome-wide significance (GWS) threshold (P<1.0 × 10-5 ). RESULTS: One region containing 10 SNPs (Equus caballus chromosome [ECA] 7: 89,601,935-94,647,192) was above the suggestive GWS threshold. Two inferred haplotypes in this region demonstrated significant differences (P<0.001) between cases and controls, with the most frequent haplotype resulting in a significantly increased risk of DLC. MAIN LIMITATIONS: Small sample size as a result of stringent phenotyping protocols. CONCLUSIONS: The current study highlights a candidate genomic region on ECA7 as potentially important with regard to the manifestation of DLC. Further exploration of this region and the genes included within it will bring veterinarians and researchers closer to fully understanding the biological mechanisms underlying DLC in horses.

Behavioural fever boosts the inflammatory response in rainbow trout Oncorhynchus mykiss.

Behavioural fever, manifested as an increased preferred temperature, was shown in rainbow trout Oncorhynchus mykiss following an injection of bacterial lipopolysaccharide. Simulated behavioural fever, through a 2·5° C water temperature rise following bacterial lipopolysaccharide injection, enhanced the expression of the cytokine interleukin-1ß, in comparison with an untreated group held at the initial temperature. The present findings show that an important mediator in the immune response can be boosted through behavioural fever in fishes.

Monoclonal antibodies specific for neutrophil proteinase 4. Production and use for isolation of the enzyme.

Four stable hybridoma cell lines producing monoclonal antibodies specific for neutrophil proteinase 4 (NP4) were established and one monoclonal antibody was chosen to produce an immunoaffinity-resin for the purification of NP4. In a precipitation assay system these antibodies bound NP4 in a dose-dependent manner, but did so neither with neutrophil elastase nor with cathepsin G. NP4 was purified and electrophoresis of the affinity-purified enzyme in sodium dodecyl sulfate polyacrylamide gels resulted in a single Mr = 30,000 polypeptide. The purified enzyme digested fibrin but not elastin and it cleaved Boc-Ala-ONp readily (Km = 0.47mM) at neutral pH, but had no effect on Suc-[Ala]3 Nan and N-Suc-[Ala]2-Pro-Phe-pNA. The proteolytic activity was inhibited by DFP, alpha 1 PI and alpha 2 M with a Ki of 10(-9)M for the NP4-alpha 1 PI complex. The NH2-terminal sequence and the amino-acid composition of NP4 were distinct from those of elastase and cathepsin G. Neutrophils contain large amounts of NP4 as judged by the comparable amounts of elastase- and NP4-alpha 1 PI complexes present in inflammatory exudates.

Outbreaks of infections with erythromycin-resistant group A streptococci in child day care centres.

Erythromycin-resistant group A streptococci (ERGAS) are considered rare in Sweden. In the county of Halland (240,000 inhabitants) in southern Sweden, we had 294 isolates of ERGAS between January 1984 and June 1985. Almost all strains were of T-type 12 and only resistant to erythromycin (MIC values approximately 8 g/l). Seven child day care centres (DCC) were involved in the outbreaks and on average 49% of all children were infected in each outbreak. Employees were seldom infected (8%), but parents and siblings more often (23% and 36%). One course of phenoxymethylpenicillin succeeded in eradicating ERGAS from 75% of those infected. The ERGAS strains are now established in southern Sweden and account for about 2% of all group A streptococcal infections in the county of Halland.

Radioimmunological quantitation of the urinary trypsin inhibitor in normal blood and urine.

A radioimmunoassay for measurement of the urinary trypsin inhibitor in human serum and urine is described. Because of the immunological cross-reactivity between the inter-alpha-trypsin inhibitor and the urinary trypsin inhibitor the plasma and serum were treated with perchloric acid to precipitate the inter-alpha-trypsin inhibitor. Gel filtration of serum before and after acid treatment showed identical peaks corresponding to the urinary trypsin inhibitor. The normal level of the urinary trypsin inhibitor in fresh plasma from 30 blood donors was 6.38 +/- 0.33 mg/l (SEM), and in sera from 24 healthy volunteers 7.14 +/- 0.27 mg/l (SEM). In urine from 23 healthy volunteers the normal excretion was 8.17 +/- 1.18 mg/24 h (SEM).

The effect of the secretory leukocyte protease inhibitor on leukocyte proteases released during phagocytosis.

The human secretory leukocyte protease inhibitor effectively binds and blocks the digestive activity of elastase released from PMN leukocytes during phagocytosis of opsonized yeast particles. About 25% of the alpha 1-protease inhibitor present in the incubation medium is inactivated during the phagocytosis, while the secretory leukocyte protease inhibitor retains more than 90% of its inhibiting capacity.

Quantification of granulocyte elastase inhibitors in human mixed saliva and in pure parotid secretion.

The predominant inhibitors of granulocyte elastase in plasma (alpha 1-proteinase inhibitor and alpha 2-macroglobulin) together with antileukoproteinase were quantified in parotid secretion and mixed saliva. Antileukoproteinase was the only inhibitor found in parotid saliva and was present in a concentration about 30 times the serum level, suggesting a local production. In mixed saliva, antileukoproteinase accounted for more than 70% of the molar concentration of the granulocyte elastase inhibitors studied. alpha 1-Proteinase inhibitor was measurable in about 1/3 of the specimens of mixed saliva. In parotid secretion, antileukoproteinase was present only as a free, active inhibitor. In mixed saliva about 15% of antileukoproteinase was in complex with granulocyte elastase, while the remaining amount of 85% was inhibitorily active. This suggests that antileukoproteinase has a biological function in a local defence mechanism directed towards the effects of granulocyte elastase in the oral cavity and salivary glands.

Studies on the interaction between leukocyte elastase, antileukoproteinase and the plasma proteinase inhibitors alpha 1-proteinase inhibitor and alpha 2-macroglobulin.

The dominating inhibitor of leukocyte elastase in human respiratory tract secretions is a low molecular mass inhibitor, designated antileukoproteinase. An equimolar antileukoproteinase-elastase complex was produced and subjected to gel filtration after differing time intervals and was found to be stable. On addition to human serum, however, elastase dissociated from antileukoproteinase and formed a complex with alpha 1-proteinase inhibitor. A small amount of elastase was also found bound to alpha 2-macroglobulin. Antileukoproteinase was capable of inhibiting elastase bound to alpha 2-macroglobulin. This inhibition was more complete and more rapid when the alpha 2-macroglobulin-elastase complex was in a molar ratio of 1:1 than in a ratio of 1:2.

A radioimmunoassay for measurement and characterization of human antileukoprotease in serum.

This report describes a radioimmunological method for the measurement of the protease inhibitor antileukoprotease in nanogram quantities. Antileukoprotease, previously found in bronchial secretions, has now also been found in serum using this radioimmunologic technique. In healthy blood donors the serum level was 126 micrograms/l. The serum immunoreactive antileukoprotease was found in a free form and did not show any antigenic cross reaction with the normal plasma protease inhibitors. Further, it was also found to be active and to form a complex with active human granulocyte elastase.

Localization and quantitation of a low molecular weight proteinase inhibitor, antileukoprotease, in the human uterus.

Antileukoprotease was demonstrated in the cervical mucosa, but was absent in the endometrium. It was shown immunohistologically to predominate in the epithelial lining of the cervical crypts. High concentrations were found in the cervical mucus. Although antileukoprotease was not present in the endometrium, low concentrations were found in the uterine fluid, probably secondary to diffusion from the cervical mucus. The concentration of antileukoprotease in cervical mucus varied greatly during the menstrual cycle, but no midcycle minimum was found. Increased concentrations were found in samples obtained during the week preceding onset of the menstruation in most women. Antileukoprotease was present in uterine fluid from intra uterine device (IUD) non-users in its free form. In fluid from IUD users it was partly in its free form, and partly in a complexed form. The major part of the non-complexed portion was biologically active. The complex consisted, at least partly, of elastase bound to antileukoprotease. Antileukoprotease may thus contribute to the neutralization of granulocyte elastase in the uterine fluid of IUD users.