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Biomedical subjects

D Stone

Publications and source records attributed to D Stone.

175 records · Page 10Linked to original sources
PubMedDate not supplied

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↗
PubMedDate not supplied

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↗
PubMedDate not supplied

The use of exercise technetium-99m 2-methoxy-isobutyl-isonitrile (99mTc-Sestamibi) perfusion scanning in the detection of acute rejection after cardiac transplantation.

Acute cardiac rejection remains an important cause of death during the first year following cardiac transplantation. Right ventricular biopsies at regular intervals are the main method of detecting rejection, although it is invasive. Unfortunately, non-invasive methods of detecting rejection have not proved reliable enough to replace cardiac biopsies. We assessed the usefulness of technetium-99m 2-methoxy-isobutyl-isonitrile (99mTc-Sestamibi) perfusion scanning in detecting acute rejection in 12 human orthotopic cardiac transplant recipients. Rest and exercise studies and right ventricular biopsies were performed on two occasions. Isotopic evidence of rejection was defined as a perfusion abnormality on either the resting or exercise studies. 99mTc-Sestamibi studies successfully identified acute rejection in 8 of 11 rejection episodes (p less than 0.04). The calculated sensitivity and specificity of 99mTc-Sestamibi scanning were both 72%. Perfusion scanning with 99mTc-Sestamibi may be useful in the diagnosis of acute rejection in cardiac transplant recipients.

Adult↗