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Biomedical subjects

B L Roberts

Publications and source records attributed to B L Roberts.

At least 109 records · Page 6Linked to original sources

Electron microscopic observations of the mesencephalic nucleus of the fifth nerve in the Selachian brain.

The mesencephalic nucleus of the trigeminal nerve (mes V) in the brain of the skate (Raja oscellata) was studied by electron microscopy. Mes V neurons are large (40-80 mum diameter) and are located in the periventricular grey matter. Their perikaryal cytoplasm is rich in Golgi apparatus, small mitochondria, rough endoplasmic reticulum, polysomes and bundles of neurofilaments. A striking feature is the presence of masses of glycogen granules, at times surrounded by membrane wrappings and lysosomal bodies. Two types of conventional synaptic contacts were made onto mes V perikarya and dendrites. One had round, agranular vesicles and usually also contained dense-cored vesicles, the other had flattened, pleomorphic, agranular vesicles and usually lacked dense-cored vesicles. Additional membrane complexes consisting of a region of gap junction flanked by sites of desmosomal attachment were observed to link neighbouring mes V neurons. Somato-somatic, dendro-somatic, axo-somatic, and dendro-dendritic junctions were noted. Except for the somato-somatic union, one or more chemical synapses were located close to the sites of gap junctions.

Animals↗

Drug interactions in the horse: effect of furosemide on plasma and urinary levels of phenylbutazone.

Horses pretreated with 6.6 mg/kg of phenylbutazone were injected with 1 mg/kg of furosemide intravenously. Furosemide had no clinically significant effect on either plasma levels or plasma half-life of phenylbutazone. Furosemide reduced urinary levels of phenylbutazone 18-fold to concentrations which may result in inconsistent drug detection in routine screening tests. The results show that it is not possible to monitor compliance with phenylbutazone medication rules by means of urinalysis alone if the use of furosemide is permitted. Furosemide treatment, however, does not interfere with monitoring by plasma level determinations.

Animals↗