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Biomedical subjects

R H Simon

Publications and source records attributed to R H Simon.

80 records · Page 5Linked to original sources
PubMed1978

An octamer of histones H3 and H4 forms a compact complex with DNA of nucleosome size.

Equimolar mixtures of histones H3 and H4 have been reconstituted onto DNA of nucleosome core size. Two distinct complexes are formed in a relative abundance that depends on the starting ratio of H3 + H4 to DNA. One of these complexes contains two H3-H4 dimers for each DNA molecule, and has a sedimentation coefficient of 7.5S. The other complex contains an octamer consisting of four H3-H4 dimers, and has a sedimentation coefficient of 10.4S. On the basis of these measurements, we conclude that the octamer complex (but not the tetramer complex) is a fully folded, compact structure resembling the nucleosome.

Animals↗
PubMed1976

Cerebrospinal fluid shunt infections with anaerobic diphtheroids (Propionibacterium species).

The clinical and laboratory findings in six cases of anaerobic diphtheroid infection of cerebrospinal fluid shunts are described. These organisms have been infrequently reported as a cause of shunt infections but our data indicate that such infections may be more common than currently appreciated. Propionibacterium species are common contaminants of cerebrospinal fluid specimens, but when isolated from the spinal fluid of a patient with a shunt who has symptoms and signs compatible with infection, the organism should not be dismissed as a contaminant. Fever was a constant finding frequently accompanied by signs of central nervous system dysfunction. Spinal fluid pleocytosis was usually limited to 1 to 200 cells and protein and sugar values were variable. The organisms grow slowly, therefore spinal fluid cultures should be held for at least 14 days before they are reported as negative.

Bacterial Infections↗
PubMedDate not supplied

Experiences with electrical stimulation devices for the control of chronic pain.

The results of a study involving the treatment of pain syndromes by electrical stimulation in 98 patients are reported. Advantages and disadvantages of three electrostimulation techniques--transcutaneous stimulation, peripheral nerve stimulation, and dorsal cord stimulation--are discussed. Also included is a brief discussion of the possible mechanism of suppression of pain stimuli.

Chronic Disease↗