Caseous lymphadenitis: an increasing cause for concern.
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Animals↗
Biomedical subjects
M J Glover
Publications and source records attributed to M J Glover.
Extrinsic current and flash sensitivity in turtle cones.
The effects of hyperpolarizing current and background light on intracellular responses of red cones in turtle were compared. Even though a background light always reduced response amplitude, hyperpolarizing current did so in only 25% of the cells studied. When hyperpolarizing current reduced response amplitude it also produced changes in response kinetics and the intensity-response relationships, but these changes differed from those produced by background light. Considerably greater hyperpolarization was required with current than with light to produce equivalent reductions in amplitude. The results suggest that current reduces amplitude by activating a membrane conductance, while background light acts through a different mechanism.
Action Potentials↗
Are albino rats night blind?
Based on single-unit recordings from the superior colliculus and optic nerve, albino rats recently were reported to have dark-adapted thresholds that are 2 log units higher than those of pigmented rats. To confirm this result, electroretinograms (ERG) were recorded with pupillary light reflex thresholds from the same strains of albino (CD) and pigmented (Long-Evans hooded) rats. Neither ERG nor pupil measurements showed higher dark-adapted thresholds for albino relative to pigmented animals. Both groups had dark-adapted thresholds close to the thresholds found for hooded animals in the reported study. These experiments measuring ERGs and pupillary light reflexes do not verify the report of night blindness in albino rats.
Albinism↗
A questionnaire survey of the prevalence of scrapie in sheep in Britain.
An anonymous, self-administered questionnaire has been used in two independent surveys to try to determine the prevalence of scrapie in the national sheep flock. The disease was recorded in 35 counties in England and Wales. About a third (26.5 and 37.3 percent) of respondents owning 100 or more sheep indicated that they had seen sheep with scrapie in their flocks. The incidences of clinical cases recorded in affected flocks in the two surveys were 0.5 and 1.1 cases/100 ewes/year. At present there is no control over the disposal of these animals. If as has been suggested, an increase in the prevalence of scrapie was a contributory factor in the emergence of bovine spongiform encephalopathy, it would seem logical that measures should be introduced to monitor the prevalence and incidence of scrapie and to control the disposal of clinical cases.
Animals↗
Identification of the denaturants in surgical spirits B.P.C. by using thin-layer chromatography.
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Chromatography, Thin Layer↗
Electrophysiological estimates of visual sensitivity in albino and pigmented mice.
We have estimated the absolute threshold of congenic albino and pigmented mice (C57) using ERG, pupillary light reflex, and VEP. We are unable to detect strain differences using ERGs or VEPs, but pupillary thresholds appear to be different. In addition, as we have previously reported for rats, VEP thresholds are considerably lower than the ERG b-wave thresholds. The VEP thresholds agree with behavioral data from pigmented mice made by others. The mouse VEP thresholds are close to the VEP thresholds in rats and the psychophysical thresholds of two human observers.
Albinism↗