CAUDATE NUCLEUS LESIONS: BEHAVIORAL EFFECTS IN THE RAT

Bilateral lesions within the caudate nucleus led to a marked impairmentc on acquistion and retention tion of a spatial alternation habit but produced no deficit in Hebb-Williams maze performance. Conversely, subtotal bilateral lesions of posterior cortex produced no significant deficit on the alternation habit but markedly impaired maze performance.     

Femoral Strain Distribution and Subsidence After Physiological Loading of a Cementless Canine Femoral Prosthesis: The Effects of Implant Orientation, Canal Fill, and Implant Fit

Twelve normal greyhound femora were divided into three groups. In group one, femoral stems were placed in neutral position with maximal fill. Group two had undersized femoral stems placed in neutral position. Group three had undersized femoral stems placed in varus position. Intact and implanted femora were loaded from 10 newtons (N) to 300 N in axial compression at a rate of 25 N/s for 10 replications. A strain gauge analysis showed that the strain distribution of all implanted femora were substantially different from intact femora, but femora with large implants placed in neutral position had the least amount of deviation from normal. An undersized stem in neutral position had significantly less compressive longitudinal strains along the proximomedial and proximocranial cortices. An undersized stem in varus position improved implant fit along the proximomedial and distolateral cortices, which resulted in increased tensile hoop strains. There were multiple significant correlations between the strain data and implantation variables (implant alignment, canal fill, and implant fit). Subsidence was significantly greater for the undersized implant in neutral position. There was not a difference in subsidence between the large neutral and varus groups. The most important variable that decreased subsidence was increased lateral implant fit ( r = -0.86, P = .0003).     

Hemodynamic Effects of Intravenous Midazolam-Xylazine-Butorphanol in Dogs

The hemodynamic effects of a mixture of midazolam (1.0 mg/kg), xylazine (0.44 mg/kg), and butorphanol (0.1 mg/kg) were evaluated in six adult dogs. The dogs were anesthetized with isoflurane for instrumentation. As the dogs returned to consciousness, baseline values were recorded and the midazolam-xylazine-butorphanol mixture and glycopyrrolate (0.01 mg/kg) were administered intravenously (IV). Hemodynamic data were recorded 3, 10, 20, 30, 40, 50, and 60 minutes after injection. Mean arterial pressure (AP), mean pulmonary arterial pressure (PAP), heart rate (HR), rate-pressure product (RPP), mean pulmonary capillary wedge pressure (PCWP), systemic vascular resistance (SVR), and right ventricular stroke work index (RVSWI) were increased significantly above baseline values. Cardiac output (CO), stroke volume (SV), cardiac index (CI), stroke index (SI), mean central venous pressure (CVP), and left ventricular stroke work index (LVSWI) were decreased significantly below baseline values. When administered IV at the dosages used in this study, midazolam-xylazine-butorphanol-glycopyrrolate induced profound acute alterations in several critical hemodynamic variables.     

Stimulation of frontal cortex and delayed alternation performance in the monkey

Unilateral or bilateral stimulation of the region surrounding the sulcus principalis of the cortex of the monkey interferes with delayed alternation performance. It is without effect on auditory discrimination performance. Bilateral stimulation is more disrupting than unilateral stimulation. The impairment is limited in time to the period of stimulation and is fully reversible.     

PROVITAMIN A2 FROM LUTEIN

Alfalfa lipids were treated with p-toluenesulfonic acid in benzene under reflux; after saponification, chromatography of the unsaponifiable portion yielded a carotenoid having a single absorption maximum at 460 mmicro in ethanol and hexane. Its properties correspond to those of the dehydration product of lutein, 3'-hydroxy-3,4-dehydro-ss-carotene, for which the name "anhydrolutein" is proposed. Vitamin A depleted chicks convert this pigment to vitamin A(2), as shown by the high ratio of absorbancies at 693 and 620 mmicro in a mixture of CHCI(3) and SbCl(3). and the absorption maximum at 350 mmicro in hexane exhibited by the liver lipids. The possible role of this pigment in the biogenesis of vitamin A(2) is discussed.     

A pharmacokinetic basis for the administration of digoxin to puppies

The pharmacokinetics of digoxin were investigated in five 15-day-old puppies. Following administration of 30 μg/kg digoxin intravenously, multiple serum samples were collected and assayed by radioimmunoassay. Data was analysed by non-linear least squares regression analysis.
The mean biological half-life of digoxin in puppies was 22.7 h and the mean volume of distribution by extrapolation was 14.4 litres/kg. The data collected along with data from the literature was applied to standard pharmacokinetic equations to formulate tentative doses of digoxin. The maintenance doses calculated for puppies were, in μg/kg/24 h, 15 for the intravenous injection, 18 for the pediatric elixir and 22 for the tablet.
When the above doses of digoxin were administered to six 31-day-old Beagle pups, resultant plasma digoxin concentrations measured over 12 days were mostly lower than expected but were nevertheless within the proposed therapeutic, non-toxic range of 0.5 to 2.5 ng/ml.     

Pest management with biopesticides

Biopesticides are attracting interest as alternatives to conventional pesticides but without many of the non-target effects, promising a better record of safety and sustainability in pest control practices. In this article we summarize and discuss the current status and future promise of biopesticides, including how biopesticides use may increase the quality and safety of the food supply.     

Use of genetic markers in growth testing of common carp, Cyprinus carpio L., carried out over 2 or 3 year cycles

Abstract. A method of testing the growth of different genetic groups of common carp, Cyprinus carpio L., over 3 year cycles was demonstrated. In European aquaculture, attaining market weight of common carp usually requires growth periods of 3 years. Typical mean weights at the end of the first year are 20 to 40g. For genetic testing, each progeny is nursed in a separate first-year pond. Co-stocking these nursery ponds with samples of a genetically marked group of carp is a convenient method of multiple nursing for second- and third-year testing. This method does not require additional ponds for generating multiply nursed samples.
Four successive experiments were carried out using this method of testing. Each experiment was run over a period of 3 years. The modified multiple nursing method generated sufficiently large weight differences only in one experiment. In the others, weight differentiation was small and unreliable, or several multiply nursed groups were lost or unidentifiable. Some improvements of this method are suggested. The genetic groups participating in the test included Ropsha carp, an Estonian strain and a strain of German mirror carp. The results are consistent with a similar study involving Chinese and European races of common carp.