Biomedical subjects

P R Singer

Publications and source records attributed to P R Singer.

12 recordsLinked to original sources

PubMed1990

Reduction in radiation exposure during coronary angiography.

In addition to lead shielding, increased distance between the operator and x-ray source will lower radiation exposure. To utilize this principle, we interposed a 24 in. piece of pressure tubing between the catheter used for coronary angiography and the manifold apparatus. Radiation exposure to the hand of the operator during coronary angiography was compared with and without the extension tubing. When corrected for the differences in exposure time, operator exposure was 5.38 mrem/min without the extension and 4.84 mrem/min with the extension. Although this is a small difference in exposure/min, a substantial reduction in exposure could accumulate over a 1 yr period. Insertion of this extension tube into the catheter system is a simple and safe way to further reduce operator exposure during coronary angiography.

Cardiac Catheterization↗

PubMed1981

One-hour intraocular pressure response to timolol. Lack of correlation with long-term response.

The initial topical administration of 1 drop of 0.25% timolol maleate in 25 nontreated ocular hypertensive patients resulted in a significant reduction of mean intraocular pressure one hour later, from a baseline of 28.1 +/- 5.3 (mean +/- SD) mm Hg to 18.5 +/- 4.5 mm Hg. Two patients (8%) failed to show at least a 10% decreases in IOP one hour after the initial administration. After three to four weeks of twice a day unilateral therapy with 0.25% timolol, mean IOP increased to 21.1 +/- 4.2 mm Hg. At this time seven patients (28%) failed to obtain a 10% decrease in IOP from topical timolol administration. Changing to 0.5% timolol for three to four weeks did not cause an additional significant lowering of IOP (20.4 +/- 3.5 mm Hg). At this time five patients (20%) had less than a 10% reduction in IOP. The one-hour response failed to predict future IOP nonresponsiveness.

Administration, Topical↗

PubMed1979

Recurrent orbital and metastatic melanoma in a patient undergoing previous glaucoma surgery.

A 61-year-old woman had unilateral acute angle-closure glaucoma and subsequently underwent a Scheie filtering operation. After a two-week interval, a large choroidal and ciliary body melanoma in the glaucomatous eye was found. No evidence of metastatic disease was found and the eye was enucleated. Histopathologic sections did not show extrascleral extension. Two and one-half years later the patient developed local orbital recurrence of the melanoma and fatal metastatic disease. We hypothesized a possible causal relationship between the filtering surgery and the local and systemic recurrence of the tumor.

Choroid Neoplasms↗

PubMed1977