Daniel M. Lewis

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1. Rat soleus muscles were denervated for 6-10 months; some of these were chronically stimulated for the last 3-8 weeks before recording. The muscles were fixed at physiological lengths and embedded in epoxy resin. 2. Sections for light microscopy were stained with p-phenylenediamine. Denervation reduced the mean cross-sectional area of fibres to 3% of(More)
1. Rat soleus muscle was denervated by sciatic transection and electrically stimulated for periods of between 3 and 9 weeks with intermittent 1 s bursts of pulses. Most of the bursts were either repeated every 90 s and pulses within them had frequencies between 10 and 100 Hz, or had a frequency of 50 Hz and were repeated at intervals between 60 and 600 s.(More)
The mitotic activity in muscles of growing rats and the effect of denervation were studied by means of continuous infusion of 5-bromo-2-deoxyuridine (BRDU). Denervated muscles after 10 weeks contained 20 to 60% fewer muscle nuclei than normal; BRDU labeled about 25% of the nuclei of normal soleus and extensor digitorum longus (EDL) and of denervated EDL(More)
1. Isometric contractions of fast and slow twitch muscles of rats were recorded 1-42 days after denervation. 2. The major changes occurred over the period from 2 to 6 days after denervation. These changes were qualitatively similar in the two types of muscle. The most important effects were on the twitch: times to peak and half relaxation were prolonged,(More)
1. Physiological properties of motor units in the soleus muscle were studied in anaesthetized rats using ventral root splitting to isolate single units. 2. Motor unit types were classified by the same criteria used to classify cat hindlimb motor units into types FR (fast-twitch, fatigue-resistant) and type S (slow-twitch, fatigue-resistant). Type FR units(More)
1. Isometric contractions of kitten soleus and flexor hallucis longus (FHL) muscles have been examined for evidence of polyneuronal innervation. The sum of tetanic tensions of two almost equal divisions of the ventral roots was greater than the tetanic tension elicited by stimulating both the divisions simultaneously. The difference was large in kittens(More)
1. Isosmetric contractions of cat flexor digitorum longus whole muscles and of functionally isolated motor units have been measured under conditions similar to those used by Buller & Lewis (1965a).2. Motor unit twitch time to peak was inversely related to axonal conduction velocity. The logarithm of tetanic tension was directly related to conduction(More)
Effect of lipopolysaccharide (LPS) on RAW264.7 macrophage cell line was studied. LPS-treated RAW264.7 cells increased in cell size and acquired distinct dendritic morphology. At the optimal dose of LPS (1 μg/ml), almost 70% RAW264.7 cells acquired dendritic morphology. Flow cytometric studies indicate that the cell surface markers known to be expressed on(More)
Brown Norway rats were exposed by intratracheal instillation of saline, carbon black (CB), or diesel exhaust particles (DEP) (5 mg/kg) on day 1, followed by exposure to ovalbumin (OVA, 90 mg/m(3)) or saline for 30 minutes on days 1, 8, 15, and 29. Animals were sacrificed on day 30. The DEP, CB, or OVA exposure alone did not result in abnormal levels of(More)
1. The contractile properties of fast-twitch (extensor digitorum longus or EDL) and slow-twitch (soleus) muscles in the rat were followed for periods of between 4 and 10 months after denervation. The effects of chronic electrical stimulation during the last 3-8 weeks of denervation were investigated. 2. The fall in tetanic tension that follows axotomy ended(More)