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Biomedical subjects

T S Stevens

Publications and source records attributed to T S Stevens.

25 records · Page 2Linked to original sources

De novo lesions in presumed ocular histoplasmosis-like syndrome.

Two patients with multifocal choroiditis similar or identical to POHS are presented. Colour photographs and fluorescein angiography document the occurrence of de novo lesions in the originally involved eye. The cases also demonstrate the development of new choroidal lesions within the originally involved eye, the early evolution of the "basic choroidal lesion", and the need for fluorescein angiography for visualizing the underlying choroidal lesion.

Adult↗

Spontaneous remodeling of the peripheral retinal vasculature in sickling disorders.

Periodic photographic and angiographic surveys of patients with the earliest stages of sickle retinopathy showed a number of fundus findings. In seven cases (sickle cell anemia, four; sickle cell hemoglobin C, three), these findings included: (1) a variety of vascular abnormalities in the equatorial and post-equatorial retina such as segmented dilations of the vessel walls, hairpin-shaped vascular loops, hypertrophic, tortuous A-V anastomoses, intraluminal plugs, closure and loss of capillary bed, and terminal budding of capillaries; and (2) a continuous, spontaneous remodeling of the peripheral retinal vasculature due to successive closures and reopenings of equatorial retinal vessels. A centripetal recession of the peripheral retinal vasculature usually resulted. No correlation between the ophthalmoscopic and the systemic condition of the patients could be made.

Adolescent↗

Cryotherapy of proliferative sickle retinopathy. Part I. Single freeze-thaw cycle.

Transconjunctival cryocoagulation was used to treat proliferative sickle retinopathy in 6 patients. Ten eyes were treated with a single freeze-thaw cycle and were observed for 3 to 18 months. Nine of 13 (70%) neovascular lesions were completely closed without occluding major vascular trunks, while the remaining 4 (30%) showed marked attenuation.

Adolescent↗

Fatty acids in blue-green algae: possible relation to phylogenetic position.

Analyses of the lipids in five species of blue-green algae show that the fatty acids are largely the C(16) and C(18) acids. The only alga that could be grown heterotrophically, Chlorogloea, formed the triply unsaturated C(18) acid in the light but only the doubly unsaturated C(18) acid in the dark. Examination of these results and the results of others suggest that, except for one species, the more highly unsaturated acids are found in the morphologically more complex algae. The fatty acid compositions of blue-green algae are different from the fatty acid composition of the other prokaryotic organisms, the bacteria. It is speculated that the diversity of the patterns of fatty acid composition among the blue-green algae could be of phylogenetic significance.

Alkenes↗

The influence of subconjunctival depot corticosteroid on choroidal detachment following retinal detachment surgery.

This study indicates that primary retinal detachment surgery on patients aged 55 or over is complicated by uveitis and choroidal detachment at approximate rates of 24% and 44%, respectively. These complications did not influence the anatomic cure rate or recovery of visual acuity. Although only 89 patients were recruited, the technique of random selection equally distributed the parameters studied and provided results of high reliability. The internal controls of the protocol prevented the examiners from being aware of whether the drug or placebo had been administered. We were concerned that the corticosteroid injection might have been producing the apparent increase in infection rate of 7.7% and the study was temporarily discontinued. Because statistical analysis showed there was no significant difference in infection rate between the treatment and control groups, the project could have been continued again.

Aged↗