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Biomedical subjects

L A Marco

Publications and source records attributed to L A Marco.

53 records · Page 3Linked to original sources

Sarcomeric oscillations in frog skeletal muscle fibers.

Brief asynchronous, small-amplitude, cyclic, longitudinal displacements of the striations of frog skeletal muscle fibers were observed with ordinary light microscopy after application of caffeine and certain quaternary ammonium compounds. With time these oscillations became synchronized and evolved into peristaltic-like movements. The oscillations were influenced by sarcomere length, temperature, external concentration of calcium ions, membrane potential, and disruption of the transverse tubules.

Action Potentials↗

Narcolepsy with tinnitus aura: interpretation.

A fifty-five year old man was admitted to our ward for evaluation of narcoleptic-cataplectic attacks which were signaled by a "hissing sound like high pressure steam leaking out of a pipe." This tinnitus was exclusively localized to the right ear. It started about sixty-to-ninety seconds before the cataplectic episode (affecting mostly the jaw muscles) and lasted through part of it as it became progressively louder toward the end and ceased abruptly. It is postulated that, along with the collapse of tonic musculature of the mandible, a decrease of proprioceptive tone also affected the tensor tympani muscle leaving the middle ear vulnerable to internally generated noise. We further postulate that tinnitus was finally arrested by the generation of phasic bursts of contraction of the tensor tympani and/or the stapedius muscle at a later stage of cataplexy.

Electroencephalography↗