Factors associated with whole carcass condemnation rates in provincially-inspected abattoirs in Ontario 2001-2007: implications for food animal syndromic surveillance

Background  

Ontario provincial abattoirs have the potential to be important sources of syndromic surveillance data for emerging diseases of concern to animal health, public health and food safety. The objectives of this study were to: (1) describe provincially inspected abattoirs processing cattle in Ontario in terms of the number of abattoirs, the number of weeks abattoirs process cattle, geographical distribution, types of whole carcass condemnations reported, and the distance animals are shipped for slaughter; and (2) identify various seasonal, secular, disease and non-disease factors that might bias the results of quantitative methods, such as cluster detection methods, used for food animal syndromic surveillance.     

Molecular modelling of the interactions of tetra-(4-N-methylpyridyl) porphin with TA and CG sites on DNA.

The molecular structure of the DNA-intercalating ligand tetra-(4-N-methylpyridyl) porphin has been determined by X-ray crystallography. The porphyrin has a precise centre of symmetry; the central core is planar, with the N-methylpyridyl groups inclined to it at angles of 66-72 degrees. Molecular modelling of this structure into TpA and CpG sites of intercalated DNA, has been performed, and approximate energetics calculated. It has been shown that only the CpG site can have full ligand intercalation, since the thymine methyl group sterically hinders such geometry at TpA sites. Modelling indicates the importance of electrostatic effects in the low-energy forms of intercalated and part-intercalated complexes at both sequences.     

Knowledge and experience of young people regarding drug abuse, 1969-89.

OBJECTIVE--To establish a baseline of knowledge to plan an effective health education programme in schools. The survey was repeated at five year intervals from 1969 to 1989. DESIGN--To preserve consistency, the same anonymous questionnaire, which was confidential to the research workers, was used throughout. SETTING--Three secondary schools in Wolverhampton in different parts of the town and representing different social groups. SUBJECTS--Sample sizes ranged from 471 fourth year pupils (aged 14 to 15) in 1969 to 540 in 1984 and 380 in 1989, the decrease being due mainly to the falling birth rate. There were slightly more girls than boys, and the pupils covered the whole range of academic ability. RESULTS--Over the 20 years the proportion of pupils who knew someone taking drugs more than doubled from 15% (71) to 31% (117) and the proportion who had been offered drugs almost quadrupled from 5% (24) to 19% (72). The changes taking place over the past five years were characterised by an increased knowledge about drugs and the first mention of "crack," a purified form of cocaine, and "ecstasy" (methylenedioxymethamphetamine). Peer influence continued to be given as the prime reason for taking drugs. Over the 20 years, though less often mentioned in 1989, television and newspapers remained the most common source of information. CONCLUSIONS--These results suggest the need for responsible coverage by the mass media and for more effective health and social education programmes to prevent the spread of drug misuse.     

A molecular model for proflavine-DNA intercalation.

A molecular model has been derived for the intercalation of proflavine into the CpG site of the decamer duplex of d(GATACGATAC). The starting geometry of the intercalation site was taken from previous crystallographic studies on the d(CpG)-proflavine complex, and molecular mechanics used to obtain a stereochemically acceptable structure. This has widened grooves compared to standard A- or B- double helices, as well as distinct conformational, roll, twist and tilt features.     

Effects of spinal anesthesia on response to main pulmonary arterial distension

Nonocclusive main pulmonary arterial distension produces peripheral pulmonary hypertension. The mechanism of this response is unknown. The effects of total spinal anesthesia on the response were studied in halothane-anesthetized dogs. Before total spinal anesthesia, main pulmonary arterial balloon inflation increased pulmonary arterial pressure and resistance without affecting systemic hemodynamic variables. Both right and left pulmonary arterial pressures were monitored to exclude unilateral obstruction with main pulmonary arterial balloon inflation. Total spinal anesthesia decreased cardiac output and systemic arterial pressures. After total spinal anesthesia, main pulmonary arterial distension still increased pulmonary arterial pressure and resistance. Right atrial pacing, discontinuation of halothane anesthesia, and norepinephrine infusion during total spinal anesthesia partially reversed the hemodynamic changes caused by total spinal anesthesia. The percent increase in pulmonary vascular resistance due to main pulmonary arterial distension was similar before total spinal anesthesia and during all experimental conditions during total spinal anesthesia. The pulmonary hypertensive response is therefore not dependent on central synaptic connections.     

Map location of arginyl-tRNA synthetase mutations in Escherichia coli K-12

Summary Mutants of Escherichia coli K-12 previously isolated in the authors' laboratory have reduced arginyl-tRNA synthetase activity. The mutants fall into two classes. All mutants grow slowly on arginine-free medium. On arginine-supplemented medium some mutants grow at a normal rate (Class I) while others still grow slowly (Class II). Matings were performed to located a Class I and a Class II mutation on the E. coli chromosome map, and on the basis of our results we have assigned both to one locus, argS.     

ISOLATED NERVE ENDINGS (NEUROSECRETOSOMES) FROM THE POSTERIOR PITUITARY : Partial Separation of Vasopressin and Oxytocin and the Isolation of Microvesicles

Subcellular fractions of the bovine posterior pituitary, including one composed almost exclusively of pinched-off nerve endings (neurosecretosomes), were characterized electron microscopically, hormonally, and enzymically. 15% of the nerve terminals in the gland were isolated as neurosecretosomes, as estimated from determinations of lactic dehydrogenase, a soluble, cytoplasmic enzyme. Neurosecretosomes were subdivided into three fractions by density-gradient centrifugation. The three subfractions, each shown to be nearly homogeneous populations of neurosecretosomes by means of electron microscopic and enzymic criteria, differed from each other in their vasopressin/oxytocin (VP/OT) ratios. The VP/OT ratio increased from the lightest to the densest fraction, indicating that VP is localized to denser and OT to lighter neurosecretosomes; similar results have been obtained previously for subfractions of neurosecretory granules (NSG). No morphological differences were apparent in neurosecretosomes among the three subfractions. Although complete separation of VP and OT was not achieved, the findings suggest that VP and OT are each stored in a different species of nerve ending and support the hypothesis that a given neurosecretory cell synthesizes, stores, and secretes only one of the peptide hormones. Microvesicles, 40–80 mµ diameter and contained in typical neurosecretory cell terminals, are believed to be degradation products of membrane ghosts of depleted NSG; electron micrographs indicative of this transformation are presented. A fraction rich in microvesicles, but containing some NSG membranes, was prepared by density-gradient centrifugation of an osmolysate of neurosecretosomes. Smaller, apparently nonneurosecretory nerve endings, lacking NSG but filled with small vesicles, are occasionally seen in sections from whole gland. The vesicles in these atypical posterior pituitary nerve endings may be true neurohumor-containing, "synaptic" vesicles.     

Role of Ca2+ in induction and secretion of dengue virus-induced cytokines

The present study was undertaken to investigate the role of calcium ions (Ca₂₊) in the induction and secretion of the dengue type 2 virus induced cytotoxic factor and the cytotoxin. This was done by using calcium channel blocking drugs such as verapamil, nifedipine or diltiazem hydrochloride. The production of cytotoxic factor was significantly reduced by treatment of dengue type 2 virus infected mice with verapamil. Similarly, a dosedependent inhibition of the secretion of cytotoxic factor was observed, when spleen cells of the virus-primed mice were treatedin vitro with the 3 calcium channel blockers. The production of cytotoxin by macrophages was abrogated by pretreatment with calcium channel blockers but had little effect on its secretion as shown by treatment of macrophages with verapamil at 1 h after the induction to later periods up to 18 h. The findings thus show that in the induction of both the cytokines Ca₂₊ plays a critical role; on the other hand it is required for the secretion of the cytotoxic factor but not for that of the cytotoxin.     

Spicebush [Lindera benzoin (L.) Blume var.benzoin,Lauraceae]: A tea,spice, and medicine

The essential oils of fresh leaves, twigs, and/or fruits of spicebush cultivated in Oregon (field distilled) and Delaware (laboratory distilled) are examined by GC/MS. The oil of leaves of spicebush is notably high in 6-methyl-5-hepten-2-one (1.94% in Oregon to 34.83 ± 9.69% in Delaware). β-caryophyllene (15.26% in Oregon to 48.44 ± 1.35% in Delaware), and/or (E)-nerolidol (10.20% in Oregon to 12.05 ± 2.02% in Delaware). The oil of the twigs of spicebush is notably high in 1,8-cineole (45.41 ± 0.35% in Delaware), while the oil of the fruits is notably high in a-phellandrene (64.62 ± 0.66% in Delaware) and β-phellandrene (11.23+0.17% in Delaware).