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Biomedical subjects

R P Hamilton

Publications and source records attributed to R P Hamilton.

7 recordsLinked to original sources
PubMed2006

[Selective retina therapy in patients with diabetic maculopathy].

Selective Retina Therapy (SRT) is a new laser treatment that selectively targets the retinal pigmen epithelium (RPE). In this study, we treated 39 patients presenting with nonischemic, focal and focal-diffuse diabetic maculopathy with SRT. In the main. the results indicate that SRT had stabilizing effects on visual acuity, angiographic leakage, lipid exudation, and foveal retinal thickness. SRT is safe and is especially useful for treating pathologies that are located close to the fovea, which cannot be treated with conventional argon laser photocoagulation.

Aged↗
PubMed1999

Successful contracting depends on optimal retail pricing.

Retail price structures are a critical part of the managed care contracting process because payers use local and national charge norms to compare hospitals and to determine negotiating targets. To successfully negotiate managed care contracts, and to be able to offer sensible discounts to payers that require them, a healthcare organization needs to determine its retail prices relative to the marketplace. By measuring their charge structure's variance from those of other providers in the same market, healthcare organizations can ensure that their retail prices are competitive.

Contract Services↗
PubMed1978

Inhibition of cholesterol biosynthesis in ovine ovarian follicles in vitro by human chorionic gonadotrophin.

Cholesterol biosynthesis from DL-[2-14C]mevalonic acid ([14C]MVA) was demonstrated in ovine ovarian follicles and isolated thecal tissues and granulosal cells incubated in vitro. Thecal tissues more readily synthesized cholesterol than did granulosal cells when incubated separately, but in the intact follicle the newly synthesized cholesterol distributed evenly between the two tissue layers, indicating that the theca could act as a supplementary source of cholesterol for the granulosal cells. Human chorionic gonadotrophin (hCG) added to the incubation medium was found to inhibit cholesterol biosynthesis from [14C]MVA by intact follicles and isolated thecal tissues, but not granulosal cells. This hCG-induced inhibition was evident in whole follicles incubated for 12--48 h, but not at 3--6 h, and was demonstrated in thecal tissues incubated for 3 h. In all cases where inhibition of cholesterol biosynthesis was observed, 14C label accumulated in a product characterized by thin layer and vapour phase chromatography as lanosterol, implying that the hCG block lies between lanosterol and cholesterol. Treatment of follicles with hCG also reduced the amount of 14C label incorporated into the cholesteryl ester fraction. These changes were accompanied by a corresponding reduction in the tissue content of cholesteryl ester, but there were no changes in the specific activities to indicate that newly synthesized cholesteryl ester was used selectively as a substrate for progestin biosynthesis.

Animals↗
PubMed1978

Lipid content of sheep ovarian follicles in culture.

A detailed examination was made of the lipid content of sheep ovarian follicles maintained in organ culture, and of the effect on this of human chorionic gonadotrophin. Lipid classes were isolated by thin-layer chromatography and the fatty acid composition determined by gas chromatographic analysis. The mean total lipid content of isolated follicles, 4-6 mm in diameter, after 18 h in organ culture was 43.1 nmol/mg wet weight tissue. Five major lipid fractions were detected, namely phospholipids (21.0 nmol/mg), cholesterol (14.5 nmol/mg), triglycerides (3.1 nmol/mg), free fatty acids (1.1 nmol/mg), and cholesteryl esters (3.4 nmol/mg). The phospholipid fraction was distinctive in that it contained a large percentage of sphingomyelin (28.0%). Other phospholipids present were phosphatidyl choline (42.0%), phosphatidyl inositol (6.9%), phosphatidyl serine (6.1%), and phosphatidyl ethanolamine and phosphatidic acid (16.9%). Each lipid fraction had a characteristic fatty acid profile which was rich in the content of unsaturated fatty acids. Inclusion of human chorionic gonadotrophin (20 i.u. ml-1) in the culture medium caused no discernable effects on the follicular content of lipids nor on the fatty acid composition of individual lipid fractions.

Animals↗