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Biomedical subjects

R Perry

Publications and source records attributed to R Perry.

69 records · Page 4Linked to original sources
PubMed1977

Differentiation of slow and fast muscles in chickens.

1. The development of the characteristic histochemical appearance of the slow anterior latissimus dorsi (ALD) and fast posterior latissimus dorsi (PLD) was studied in chickens during embryonic development as well as during regeneration of minced muscle. 2. During embryonic development the activity of the oxidative enzyme succinic dehydrogenase (SDH) is higher in the slow ALD muscle already at 16 days of incubation. At this time the fast PLD has a higher activity of the glycolytic enzyme, phosphorylase. Although the histochemical appearance of the two types of muscle is already different at 16 days, their contractile speeds are still similar. No difference in myosin ATP-ase was found in the two muscles in young embryos but in 20-day old embryos the two muscles became distinctly different when stained for this enzyme. 3. When PLD muscles in hatched chickens redeveloped during regeneration in place of ALD the histochemical characteristics of the regenerated muscle resembled ALD, and when ALD regenerated in place of PLD it resembled PLD. 4. It is concluded that the histochemical characteristics of slow and fast muscles become determined during early development, even before any difference in contractile properties can be detected and that they are determined by the nerve.

Adenosine Triphosphatases↗
PubMedDate not supplied

Amyloid and Alzheimer's disease: a question of specificity.

As with potential neurotransmitter therapy, the question of how successful reducing amyloid deposits would be in the treatment of Alzheimer's disease hinges on the position of amyloid formation in the pathological cascade. Identification of the presence of A4 reactive plaques and neurofibrillary tangles, either separately or together, in an increasingly wide variety of distinct diseases strongly suggests amyloid formation is "downline" in a variety of pathological processes. Thus, there may be no reason to expect amyloid therapy to be more effective than, say, transmitter therapy and, in view of the fact that neurodegeneration probably occurs in conjunction with amyloid formation, both therapeutic approaches should perhaps be considered together until such time as the primary etiopathological event is identified.

Alzheimer Disease↗