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Biomedical subjects

M N Collins

Publications and source records attributed to M N Collins.

6 recordsLinked to original sources

Effects of imprint training procedure at birth on the reactions of foals at age six months.

REASONS FOR PERFORMING STUDY: While imprint training procedures have been promoted in popular magazines, they have received limited scientific investigation. OBJECTIVES: To determine the effects of a neonatal imprint training procedure on 6-month-old foals and to determine if any one session had a greater effect than others. METHODS: Foals (n = 131) were divided into the following treatments: no imprint training, imprint training at birth, 12, 24 and 48 h after birth or imprint training only at birth, 12, 24, 48, or 72 h after birth. Foals then received minimal human handling until they were tested at 6 months. RESULTS: During training, time to complete exposure to the stimulus was significant for only 2 of 6 stimuli. Percentage change in baseline heart rate was significant for only 2 of 10 stimuli. These 4 effects were randomly spread across treatments. CONCLUSIONS: Neither the number of imprint training sessions (0, 1, or 4) nor the timing of imprint training sessions (none, birth, 12, 24, 48, or 72 h after birth) influenced the foal's behaviour at 6 months of age. POTENTIAL CLINICAL RELEVANCE: In this study, imprint training did not result in better behaved, less reactive foals.

Age Factors↗

Capgras' syndrome with organic disorders.

Capgras' syndrome, one form of the delusional misidentification syndromes, is described. Three patients with the syndrome are reported. The first had a right cerebral infarction, the second had nephrotic syndrome secondary to severe pre-eclampsia in the puerperium, and the third had uncontrolled diabetes mellitus with dementia. Evidence is reviewed regarding an organic aetiology for Capgras' syndrome. We conclude that, when the syndrome is present, a thorough search for organic disorder should be made.

Adult↗

A structured programme for out-patient alcohol detoxification.

An out-patient alcohol detoxification service based in a psychiatric emergency clinic is described. Of 173 patients referred during the first year, 76 (44%) were accepted for the programme; 60 (79%) of these successfully completed detoxification with no medical complications. Compared with previous years, during the year of operation of the service there was a 50% fall in the number of in-patient admissions for detoxification to the local hospital. We conclude that a structured out-patient detoxification programme is safe and effective, and may obviate the need for many patients to be admitted, freeing psychiatric beds for other uses.

Adolescent↗

Autonomic response to coronary occlusion in animals susceptible to ventricular fibrillation.

Disturbances in autonomic control during myocardial ischemia may contribute significantly to the development of malignant cardiac arrhythmias. Therefore acute ischemia was induced in 29 mongrel dogs with healed myocardial infarctions during an exercise test. Seventeen animals developed ventricular fibrillation (susceptible, S), whereas 12 dogs did not (resistant, R). Before the exercise plus ischemia test a coronary occlusion was made at rest. The amplitude of respiratory sinus arrhythmia (0.24- to 1.04-Hz component of R-R interval fluctuation) was used as an index of cardiac vagal tone. Acute ischemia elicited a significantly larger heart rate increase in susceptible animals (S: control 115.6 +/- 0.8, occlusion 176.4 +/- 8.2 beats/min vs. R: control 114.6 +/- 8.9, occlusion 145.7 +/- 7.5 beats/min). Accompanying the heart rate increase were significantly greater reductions in the cardiac vagal tone index in the susceptible animals. (S: control 6.4 +/- 0.3, occlusion 2.2 +/- 0.6 ln ms2 vs. R: control 6.6 +/- 0.4, occlusion 5.1 +/- 0.5 ln ms2). beta-Adrenergic receptor blockade reduced the heart rate increases but exacerbated the reductions in the cardiac vagal tone index. These data suggest that coronary artery occlusion elicits a significantly greater increase in sympathetic activity coupled with a greater reduction in parasympathetic activity in animals subsequently shown to be susceptible to ventricular fibrillation.

Animals↗