Elements of an occupational health and safety program: deficiencies identified by AAALAC international.

An effective occupational health and safety program is critical to ensure personnel safety in working with animals. The authors present data compiled from AAALAC international site visits conducted between 1993 and 1999, which indicate how programs can fall short of current recommendations.

In-vitro activity of trovafloxacin against sensitive and resistant aerobic bacteria using the standard microdilution broth method and Etest.

A comparison of MICs of trovafloxacin (CP-99,219) determined by the standard microdilution broth method versus the Etest was performed for multiple strains of Gram-positive and Gram-negative bacteria. A comparison was also made of the in-vitro activity of trovafloxacin versus ciprofloxacin and ofloxacin. The MIC50 and MIC90 were determined by both methods for each species tested. The Etest resulted in MICs one to two dilutions higher than the microdilution broth method. Trovafloxacin was the most active agent against Gram-positive organisms. Ciprofloxacin was the most active agent against Citrobacter freundii, Proteus mirabilis, Proteus vulgaris, Morganella morganii and Serratia marcescens, while trovafloxacin had equal or greater activity compared with ciprofloxacin and ofloxacin against the other Gram-negative organisms tested. Overall, ofloxacin was the least active agent tested. In addition, the in-vitro activity of trovafloxacin or ciprofloxacin in combination with ampicillin/sulbactam, gentamicin or vancomycin was evaluated. The combination of trovafloxacin and gentamicin was synergic against two of 20 Enterococcus faecium isolates, the combination of trovafloxacin and ampicillin/sulbactam was synergic against two of 24 Enterococcus faecalis isolates, and the combination of ciprofloxacin and gentamicin was synergic against one of 25 Stenotrophomonas maltophilia isolates. All other antibiotic combinations resulted in an additive or indifferent effect.

The effect of euthanasia technique on vascular arachidonic acid metabolism and vascular and intestinal smooth muscle contractility.

This study was designed to determine the effects that specific euthanasia methods have on vascular arachidonic acid metabolism and vascular and intestinal smooth muscle contractility. Rats were euthanatized by decapitation (DC), pentobarbital overdose (PB), or anesthesia with CO2, methoxyflurane or ether followed by DC (CO2-DC, Met-DC, Ether-DC, respectively). Rabbits were killed by a similar protocol, but CO2 overexposure replaced Ether-DC. The rat and rabbit aortas produced mainly 6-keto PGF1 alpha, the prostacyclin metabolite, and lesser amounts of PGE2. No qualitative differences were seen in arachidonate metabolites. However, aortic tissue from rabbits and rats killed by Met-DC produced more prostacyclin. In contrast, aorta from rabbits euthanatized by CO2-DC produced less prostacyclin than controls, whereas aorta from rats killed in the same way yielded greater amounts of prostacyclin. Aortic tissue from rabbits killed by Met-DC and CO2-OD was less responsive to acetylcholine (ACH). Intestinal contractility to ACH was increased in rabbits when Met-DC was used as the method of euthanasia, while colon from rats sacrificed by Met-DC showed decreased responsiveness to ACH. Colon from rats killed by intraperitoneal PB exhibited altered contractility to ACH and norepinephrine. The results of this study show that methoxyflurane, carbon dioxide (rabbit) and pentobarbital (rat) alter the vascular synthesis of prostacyclin and smooth muscle contractility. We conclude that the method of euthanasia affects certain physiologic parameters and careful consideration should be given to the selection of a particular euthanasia technique.

Evaluation and characterization of the hypothyroid hyt/hyt mouse. I: Somatic and behavioral studies.

Mice homozygous for the autosomal-recessive gene hypothyroid (hyt) had congenital hypothyroidism of fetal onset after 15 days postconception. Neonatal hyt/hyt mice had reduced serum thyroxine ranging from 1/5 to 1/6 of normal as well as significantly delayed somatic and behavioral development. Delayed somatic development included retarded eye opening and ear raising, and reduced body length and body weight. The hyt/hyt animals compared to their normal littermates demonstrated delayed reflexive behavior and abnormal motor and adaptive behavior. The somatic and behavioral measures clearly distinguished hyt/hyt animals from their normal littermates even without T4 determination. The somatic and reflexive behavioral abnormalities in the hyt/hyt mouse were similar to other rodent models of human congenital hypothyroidism. The hyt/hyt mouse provided an ideal model for exploring the effect of severe primary inherited hypothyroidism related to deficient autonomous fetal thyroid function and was consistent with the hypothesis that thyroid hormone deficit in utero and in the early neonatal period significantly altered functional development.

Distribution of a monoclonal antibody-recognized protective protein immunogen on the outer membranes of Pasteurella multocida rabbit isolates.

The distribution of a monoclonal antibody (MAb)-recognized protective protein immunogen on the outer membrane of 153 Pasteurella multocida rabbit isolates was determined by dot blot (DB) analysis. MAb 1608 reacted with 36 (24%) of the 153 clinical isolates. The DB-positive clinical isolates expressed capsular antigens A, D, and nontypable and somatic antigens 2, 3, 10, 12, 15, and nontypable. Western blot (immunoblot) analysis with adsorbed and eluted MAb 1608 confirmed that the antigenic determinant identified was located on the cell surface. With MAb 1608 as a probe for antibody-accessible radioimmunoassay, 31 of 36 DB-positive P. multocida rabbit isolates were shown to have surface-exposed and antibody-accessible antigenic determinants, while 44 of 44 DB-negative isolates were negative by antibody-accessible radioimmunoassay. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed DB-negative P. multocida isolates both with (6 of 13, 46%) and without (7 of 13, 54%) the 37.5-kilodalton protein. This study establishes that the protective antigenic determinant of the 37.5-kilodalton outer membrane protein is present in 24% of rabbit clinical isolates tested and is detectable in P. multocida strains distributed among the major somatic types (3, 10, 12, and 15) and the capsular types (A and D) commonly isolated from rabbits in North America.

17 beta-Hydroxysteroid oxidoreductase: a ubiquitous enzyme. Interconversion of estrone and estradiol-17 beta in BALB/c mouse tissues.

A survey was conducted to define the sites of 17 beta-hydroxysteroid oxidoreductase activity in organs and tissues of male and female BALB/c mice, as well as the favored direction of the oxidoreductase reaction in intact tissues. The enzyme activity was assayed by use of radiolabeled estrone and estradiol-17 beta as substrates. Estrone formation from estradiol-17 beta was demonstrated in all tissues. The formation of estradiol-17 beta from estrone was demonstrated in most tissues, however, it was barely detected or was undetectable in the glandular stomach, small intestine, cecum, and large intestine. Thus, 17 beta-hydroxysteroid oxidoreductase activity is expressed in all BALB/c mouse organs and tissues. Approximately two-thirds of the tissues and organs examined, including those of the reproductive tracts, favored the conversion of estrone to estradiol-17 beta rather than the reverse reaction. The results of this study, however, represent qualitative estimates of 17 beta-hydroxysteroid oxidoreductase activity in BALB/c mouse tissues that are uncorrected for conversion to hydroxylated metabolites. These in vitro findings suggest that the 17 beta-hydroxysteroid oxidoreductase catalyzed reduction of estrone may contribute to the maintenance of physiologic levels of estradiol-17 beta in estrogen responsive tissues.

Steroid sulfatase and 17 beta-hydroxysteroid oxidoreductase activities in mouse tissues.

The metabolism of estrone sulfate and dehydroisoandrosterone sulfate to the free, unconjugated steroids, estrone and dehydroisoandrosterone, was demonstrated in more than thirty different tissues from male and female BALB/c mice. The activity of steroid sulfatase, when expressed per mg tissue, was greatest in both the pituitary gland and the adrenal glands. The pituitary gland, however, had the lowest capacity for hydrolysis of steroid sulfates while the liver had the greatest capacity. 17 beta-Hydroxysteroid oxidoreductase activity also was demonstrated in all mouse tissues by the formation of estradiol-17 beta when using estrone sulfate as the substrate. The highest apparent activity for 17 beta-hydroxysteroid oxidoreductase was found in lung tissue, and the greatest capacity to form estradiol-17 beta from estrone sulfate was found in liver, lungs, kidneys and testes. This study demonstrates that the majority of mouse tissues have steroid sulfatase and 17 beta-hydroxysteroid oxidoreductase activities.

Anomalous origin of the right subclavian artery in a marmoset (Callithrix jacchus).

Anomalous right subclavian artery in a one-day-old marmoset (Callithrix jacchus) is reported. The anomalous vessel originated with the left subclavian artery from a short trunk off the arch of the aorta, then passed posterior to the esophagus, indenting it.