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Biomedical subjects

D Stone

Publications and source records attributed to D Stone.

At least 163 records · Page 9Linked to original sources

Occurrence and formation of the N epsilon-methyl-lysines in myosin and the myofibrillar proteins.

1. Adult rabbit skeletal-muscle myosin has been shown to contain 1.0 residue of mono-N(in)-methyl-lysine and 3.3 residues of tri-N(in)-methyl-lysine per molecule of molecular weight 500000. 2. The methyl-lysines appear to be located in the subfragment 1 portion of the myosin molecule. 3. Methyl-lysines are not present in actin, tropomyosin, inhibitory factor and calcium-sensitizing factor. 4. Enzymic methylation of histidine and lysine residues of myosin has been demonstrated in vitro. 5. The methylation of histidine and lysine of the total myofibrillar protein occurs after peptide-bond synthesis. 6. Although methylated lysines and 3-methyl-histidine could not be detected by analysis of hydrolysates, radiochemical evidence is provided for the presence of these residues in the soluble-protein fraction of rabbit skeletal muscle.

Amino Acids↗

Guide wire entrapment during PTCA: a potentially dangerous complication.

The tip of a "high-torque" floppy guide wire became entrapped in a coronary artery during elective PTCA in four patients. In two it was removed through the guiding catheter, in the third an operative intervention was needed in order to free the wire, and in the fourth the remnant was left in situ. Interventional cardiologists should be aware of this potential complication.

Adult↗

Expression of tyrosine hydroxylase in the aging, rodent olfactory system.

Tyrosine hydroxylase (TH) mRNA, immunoreactivity, and activity were examined as a reflection of dopamine expression in juxtaglomerular neurons intrinsic to the olfactory bulbs of young (6-month-old), middle aged (18-month-old), and aged (25- to 29-month-old) rats and mice. TH expression was maintained at levels observed in young animals in the olfactory bulbs of aged animals from two mouse strains, C57Bl/6JNia and C57Bl/6NNia, and one rat strain, an F1 hybrid between F344 and Brown Norway strains. The parental F344 rat strain exhibited reductions in TH expression of about 20% in 26- to 29-month-old animals as compared to 6- and 18 month-old rats. However, there was significant inter-animal variability. Some aged F344 rats had TH levels that were similar and others had activity levels that were 50% of those in young and middle aged animals. Neither the general condition of the animals nor the presence of adrenal tumors predicted the individuals with reduced TH expression. Olfactory bulb size, estimated from protein content, did not differ between rats and mice of different ages. In addition, expression of olfactory marker protein, a protein found primarily in mature olfactory receptor neurons, also was unchanged indicating the maintenance of afferent innervation. These data suggest that, in contrast to other brain dopamine systems, the expression of the dopamine phenotype is maintained in the aging olfactory bulb.

Aging↗