Comparison of fluorescent antibody tests for tuberculosis and paratuberculosis with antigens coupled to insoluble spheres or taken up by macrophages

Sera of 106 cattle from farms with histories of Mycobacterium johnei infection and sera from 15 human tuberculous patients as well as a number of control sera were examined by means of two different fluorescent antibody tests (FAT) for the occurrence of antibodies against M. johnei and M. tuberculosis respectively. The antigens used were PPD johnin and PPD tuberculin. In the macrophage uptake FAT (MU/FAT) mouse macrophages after phagocytosis of the tuberculins served as the matrix; in the tests performed using the defined antigen substrate spheres (DASS) system, Sepharose beads activated by CNBr were used for the matrix. A good correlation was found between the results of the DASS/FAT and those of the MU/FAT, which is known to be a sensitive and specific test in the diagnosis of Johne's disease in cattle. It is suggested that the FAT, with utilization of the DASS system, might have good prospects for routine examination for antibodies against species of Mycobacterium.     

Mode of Binding of Fibrinogen,Fibronectin and Iron-binding Proteins by Animal Enterococci

Sixty-two animal enterococci were examined for their binding of bovine fibrinogen, porcine fibronectin, bovine lactoferrin, bovine apotransferrin and human holotransferrin in the particle agglutination assay (PAA). Individual strains expressed binding of selected glycoproteins to various degrees (0, 1, 2, 3), whereas bovine fibrinogen binding of enterococci from goats, rabbits and rodents was the strongest (3) in general. Porcine fibronectin was bound weakly (1 or 2) by enterococci from horses, dogs, poultry, rabbits and rodents, while most of the goat isolates and half of the dog feed isolates did not bind fibronectin (0). Bovine lactoferrin was bound especially by the isolates from rodents and rabbits. Bovine apotransferrin was bound very weakly (1) by only a few isolates. Human holotransferrin was bound to a greater extent than apotransferrin by some isolates from rabbits and rodents. Since multiresistant strains are preferred in our binding studies, enterococci were also examined for their antibiotic resistance pattern. Almost all investigated isolates were resistant at least to one antibiotic. However, some strains displayed resistance to five or six antibiotics of 10 antibiotics tested. In a study of the inhibitory effect of heparin, porcine mucin and hyaluronic acid, the greatest effect was observed after heparin treatment of bacterial cells. These observations, as well as the expression of heparin binding by most strains, may suggest that at least one mode of enterococcal attachment utilizes glycosaminoglycan chains present on the surface of adherent cells.     

Life expectancy in a birth cohort of Boxers followed up from weaning to 10 years of age

OBJECTIVE: To determine mortality rate over time, risk factors for death, and heritability of life expectancy in Boxers. ANIMALS: 1,733 purebred Boxers born in The Netherlands between January 1994 and March 1995. PROCEDURE: Dogs were followed up from weaning (ie, 49 days of age) to 10 years of age through use of a written questionnaire sent to owners every 6 months. Mortality rate over time, risk factors potentially associated with death, and heritability of life expectancy were examined by use of a proportional hazards model based on the Weibull distribution. RESULTS: stimated mortality rate during the 10-year study period for this birth cohort of Boxers was 45%. The probability of surviving to 5 years of age was 88%; the probability of surviving to 10 years of age was 55%. Estimated effective heritability of life expectancy was 0.076, meaning that in this population, an estimated 76% of the observed variation in life expectancy could be attributed to genetic differences among dogs that were passed from parents to their offspring. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cumulative incidence of death from weaning to 10 years of age among this birth cohort of Boxers was 45%. The estimated heritability of life expectancy suggested that life expectancy can be improved by use of selective breeding.     

Neonatal vitamin A injection promotes cattle muscle growth and increases oxidative muscle fibers

Background: Vitamin A and its metabolite,retinoic acid(RA),are important regulators of cell differentiation and organ morphogenesis.Its impact on beef cattle muscle growth remains undefined.Method: Angus steer calves were administrated with 0(control) or 150,000 IU vitamin A(retinyl palmitate in glycerol,i.m.) per calf at birth and 1 month of age.At 2 months of age,a biopsy of the Biceps femoris muscle was obtained to analyze the immediate effects of vitamin A injection on myogenic capacity of muscle cells.The resulting steers were harvested at 14 months of age.Results: Vitamin A administration increased cattle growth at 2 months.At 2 months of age,Vitamin A increased PAX7 positive satellite cells and the expression of myogenic marker genes including PAX7,MYF5,MYOD and MYOG.Muscle derived mononuclear cells were further isolated and induced myogenesis in vitro.More myotubes and a higher degree of myogenesis was observed in vitamin A groups.Consistently,vitamin A increased Latissimus dorsi(LD) muscle fiber size at harvest.In addition,vitamin A increased the ratio of oxidative type I and type IIA fibers and reduced the glycolic type IIX fibers.Furthermore,we found that RA,a key bioactive metabolite of vitamin A,activated PPARGC1 A promoter,which explains the upregulated expression of PPARGC1 A in skeletal muscle.Conclusion: Vitamin A administration to neonatal calves enhanced postnatal muscle growth by promoting myogenesis and increasing satellite cell density,accompanied with a shift to oxidative muscle fibers.     

Automated observation and analysis of earthworm surface behaviour under experimental habitat quality and availability conditions

Currently, the driving factors of active earthworm dispersal across the soil surface are not sufficiently understood, and distances traversed by individual earthworms have rarely been quantified. Research progress has been hampered by the lack of adequate observation methods as well as fast, objective and quantitative measurements of nocturnal earthworm behaviour.In this work, we report on the potential of a new, automated method using infrared-sensitive webcams and computer image analysis. Nightly surface activities of Lumbricus terrestris L. were monitored quantitatively while manipulating levels of disturbance, burrow availability and congener presence in standard observation units.The automated observation system proved to be simple and inexpensive to build, provided reliable quantitative measures of locomotive behaviour without animal disturbance, and considerably reduced human workload and bias.Waterlogging of the burrow zone stimulated surface activities around and away from the home burrow as compared to habitat disturbance by pesticide application and vibration. However, dispersing earthworms never settled in prefabricated burrows. Surface activity of individuals subjected to waterlogged conditions was influenced by the availability of alternative habitat. Minimal habitat disturbance (vibration) and the presence of conspecific individuals resulted in an increased amount of burrow-anchored, possibly sexually oriented, behaviour, but reciprocal burrow visits and mating were not observed. Pesticide application did not result in dispersal, increased foraging activities or sexual attraction attempts during this short-term study.The presence, extent and mechanisms of the remote assessment of important cues in the surroundings of the home burrow by L. terrestris need further research. Infrared monitoring opens new research avenues of earthworm surface behaviour studies (e.g. density-dependent dispersal, habitat selection, (re)colonization, invasion).     

Recent plant diversity changes on Europe's mountain summits

In mountainous regions, climate warming is expected to shift species' ranges to higher altitudes. Evidence for such shifts is still mostly from revisitations of historical sites. We present recent (2001 to 2008) changes in vascular plant species richness observed in a standardized monitoring network across Europe's major mountain ranges. Species have moved upslope on average. However, these shifts had opposite effects on the summit floras' species richness in boreal-temperate mountain regions (+3.9 species on average) and Mediterranean mountain regions (-1.4 species), probably because recent climatic trends have decreased the availability of water in the European south. Because Mediterranean mountains are particularly rich in endemic species, a continuation of these trends might shrink the European mountain flora, despite an average increase in summit species richness across the region.