Evaluating the effect of metronidazole plus amoxicillin-clavulanate versus amoxicillin-clavulanate alone in canine haemorrhagic diarrhoea: a randomised controlled trial in primary care practice.

OBJECTIVES: To investigate the benefit of supplementing amoxicillin-clavulanic acid therapy with metronidazole in dogs presenting to a primary care veterinary practice with severe haemorrhagic diarrhoea. MATERIALS AND METHODS: Prospective randomised blinded trial on dogs presenting with haemorrhagic diarrhoea of less than 3 days duration to a primary care veterinary hospital and also requiring intravenous fluid therapy. Cases were randomised to receive either metronidazole or saline, in addition to standard supportive therapy consisting of amoxicillin-clavulanic acid, intravenous fluid therapy, buprenorphine and omeprazole. Treatment efficacy was measured by duration of hospitalisation and daily scoring of disease severity. RESULTS: Thirty-four cases successfully completed the trial. There was no significant difference in hospitalisation time between treatment groups (mean for dogs receiving metronidazole was 29.6 hours and for controls was 26.3 hours) nor in daily clinical scores. CLINICAL SIGNIFICANCE: This study strongly suggests that addition of metronidazole is not an essential addition to amoxicillin-clavulanic acid therapy for treatment of severe cases of haemorrhagic diarrhoea in dogs.

Measurement of behavioral, affective, and somatic responses to pediatric bone marrow transplantation: development of the BASES scale.

A new measure to assess behavioral, affective and somatic outcomes in the acute phase of bone marrow transplant is described. The Behavioral Affective and Somatic Experiences Scale (BASES) is a 38 item nurse-report instrument, with five subscales labeled Somatic distress, Compliance, Mood/Behavior, Interactions, and Activity. A series of pilot studies were conducted to refine the content of the BASES scale and to establish its psychometric properties in terms of internal consistency, inter-rater reliability, and validity. Internal consistency (Chronbach's alpha) for the subscales ranged from .742 to .902. Inter-rater reliability was good, with a median correlation between paired nurse observations of .866. A parent report version of the BASES scale has also been developed, and the finding of significant parent-nurse correlations provides preliminary evidence of the validity of the measure. Potential uses of the BASES scale in the pediatric BMT setting are discussed.

A comparison of the effects of the novel muscarinic receptor agonists L-689,660 and AF102B in tests of reference and working memory.

Four experiments compared the CNS effects of a novel M1/M3 receptor agonist L-689,660 with those of the M1/M3 muscarinic receptor agonist AF102B. In the mouse tail-flick test of antinociception (TF) the minimum effective doses to increase tail-flick latency (MED) of L-689,660 and AF102B were 0.03 mg/kg and 10.0 mg/kg, respectively. In a rat conditioned-suppression-of-drinking (CSD) test of reference memory, doses of 0.3 and 1.0 mg/kg L-689,660 and a dose of 5.0 mg/kg AF102B reversed a scopolamine-induced deficit in performance (0.6 mg/kg). Although there was a tendency for L-689,660 to reverse the scopolamine-induced (0.4 mg/kg) performance deficit in a rat delayed-matching-to-position (DMTP) test, the difference failed to reach statistical significance. In contrast, a 5.0 mg/kg dose of AF102B potentiated the scopolamine-induced deficit in choice accuracy and the number of trials completed on this task. In a response sensitivity (RS) test, chain-pulling rates were significantly decreased by L-689,660 (MED = 0.03 mg/kg) and by AF102B (MED = 5.0 mg/kg). These results suggest that L-689,660 and AF102B may ameliorate or reverse a scopolamine-induced deficit, but only at doses that also reduce chain-pulling rates on operant schedules of reinforcement.

Behavioural and pharmacological characterization of the mouth movements induced by muscarinic agonists in the rat.

Pilocarpine administered in doses of 1.25-10.0 mg/kg (IP) produced a variety of mouth movements in the rat. The most frequent of these movements was a chewing behaviour, which increased up to a mean frequency of over 40 per min at the highest doses. Tongue protrusion and gaping also showed dose-dependent increases. Yawning tended to increase in some doses, though these increases were not significant, and yawning was relatively infrequent. Pre-treatment with scopolamine reduced these responses, while pre-treatment with methyl scopolamine did not. Injections of oxotremorine or arecoline, but not carbachol, produced dose-related increases in mouth movements similar to those produced by pilocarpine. These results suggest that mouth movements in the rat are caused by stimulation of central muscarinic receptors. This may prove to be an important behavioural sign of central cholinomimetic activity.

Response-reinforcer associations after caudate-putamen lesions in the rat: spatial discrimination and overshadowing-potentiation effects in instrumental learning.

Experiment 1 demonstrated that rats with caudate-putamen lesions show an impairment in the acquisition and reversal of a spatial maze task when compared with unoperated control subjects. Experiment 2 examined lever-press responding supported by a variable interval schedule in three groups of subjects: a group with caudate-putamen lesions, a group with lesions of the posterior cortex, and an unoperated control group. The presentation of a 0.5-s, response-contingent light correlated with reinforcement generated an elevated response rate in the two operated groups but tended to suppress responding in the control group, perhaps by overshadowing the response-reinforcer relation. Only the group with cortical lesions maintained the elevated rate when the light was uncorrelated with food delivery. Experiment 3 confirmed for these same subjects that caudate-putamen lesions produce a spatial learning deficit. No deficit was seen in the posterior cortex group. It is suggested that caudate-putamen lesions disrupt the mechanism underlying the response-reinforcer association upon which spatial maze learning and free operant responding in part depend.

A comparison of intradimensional and extradimensional shift learning in pigeons.

In each of three experiments pigeons were trained on a simultaneous discrimination between stimuli that differed in both colour and orientation. For half the birds the colour dimension was relevant and for half orientation was relevant (i.e., differences along that dimension were correlated with reward and nonreward). All birds were then shifted to a second discrimination between new colours and orientations. For half this constituted an intradimensional shift in that the previously relevant dimension remained relevant; for the remainder the previously irrelevant dimension was made relevant (an extradimensional shift). Contrary to the predictions of attentional theory, the two types of shift were learned with equal ease.

Facilitation and retardation of discrimination learning after exposure to the stimuli.

In three experiments, rats was required to learn a simultaneous discrimination in a jumping stand between horizontally and vertically striped objects. Experiment 1 showed that prior prolonged exposure to these stimuli in the rats' home cages helped them to learn the discrimination. Experiment 2 showed that a briefer period of exposure (1 hr per day for 50 days) was equally effective when the stimuli were presented in the home cage but produced a retardation of discrimination when the stimuli were presented in the jumping stand itself. Experiment 3 demonstrated that prior exposure to the jumping stand was not in itself enough to produce a retardation of subsequent discrimination learning. Some implications of these results for current theories of perceptual learning and latent inhibition are discussed.