Biomedical subjects

P V Whitmore

Publications and source records attributed to P V Whitmore.

6 recordsLinked to original sources

PubMed1991

Foscarnet therapy for ganciclovir-resistant cytomegalovirus retinitis in patients with AIDS.

Infections caused by cytomegalovirus (CMV) resistant in vitro to ganciclovir, defined as requiring greater than 6 mumols of ganciclovir for ED50 have developed in some AIDS patients with progressive CMV retinitis despite chronic ganciclovir therapy. Two such patients (CMV isolates ED50, 9.5-14.5 mumols) were treated with foscarnet, an antiviral pyrophosphate analogue to which both patients' isolates demonstrated in vitro susceptibility (ED50, less than or equal to 300 mumols). Each patient had documented retinitis progression, at 2- and 1- to 5-week intervals, respectively, despite high-dose intravenous ganciclovir therapy. Both patients responded to foscarnet therapy with cessation of viral shedding in urine and blood. After foscarnet therapy was started, retinitis stabilized in the two patients for 12 and 25 weeks, respectively, before progression recurred. Therefore, foscarnet may be effective in immunocompromised patients with rapidly progressive CMV retinitis whose CMV isolates have developed in vitro resistance to ganciclovir.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Conjunctival and canalicular papillomas and ichthyosis vulgaris.

Papillomas of the lacrimal canaliculus are very rare tumors and, when encountered in clinical practice, usually present with unilateral epiphora due to obstruction of the lacrimal drainage system. Surgical excision is usually curative although, on occasion, they may recur. The following case report concerns a patient with autosomal-dominant ichthyosis vulgaris and conjunctival and canalicular papillomas.

Adult↗

PubMed1987

The effect of rapid freezing on uveal melanomas.

We studied the immediate effects of rapid freezing on 19 variously sized uveal melanomas that were subjected to cryoenucleation using liquid nitrogen and a cryoring by light and electron microscopy and tissue culture. The freezing time and the temperature of 11 lesions were recorded. The light microscopic finding of an intranuclear clear center with peripheral displacement of clumped chromatin against the nuclear membrane was suggestive of intranuclear ice crystal formation but did not indicate cellular death of the tumors. The major ultrastructural changes, including plasmalemmal breaks, dissolution of cytoplasmic matrix, and damage to various organelles, however, suggested acute necrosis in tumors not exceeding 7 mm in elevation. Failure of the melanoma cells to grow in tissue culture and positive staining with trypan blue support the contention of tumor death. The late effects of rapid freezing were also evaluated in another case of uveal melanoma. The eye was enucleated six months after cryopexy. Histopathologic findings showed that the tumor was necrotic. Failure of the neoplasm to regress (noted clinically) was related to edema and inflammatory infiltrates.

Choroid Neoplasms↗

PubMed1985

Diffuse drusen and associated complications.

An eye of a patient with an unusual form of diffuse drusen was studied by light and electron microscopy. Examination disclosed marked diffuse and nodular thickening of the inner portion of Bruch's membrane by vesicular and curvilinear membranous profiles and basement membrane-like material that was apparently derived from the retinal pigment epithelium. Deposition of this abnormal material suggests a diffuse abnormality of the retinal pigment epithelium and predisposes to serous detachment of the retinal pigment epithelium, choroidal neovascularization, hemorrhagic detachment of the retinal pigment epithelium, and disciform scarring. The features of this case are similar to previously reported cases of diffuse drusen, but differ in the early age of onset, intensity of changes, and, in part, by the nature of the abnormal material observed.

Basement Membrane↗

PubMed1976

Aplasia of the optic nerve.

A case of unilateral true aplasia of the optic nerve in an otherwise normal and healthy child is presented. Twenty-eight previously reported cases of aplasia have been reviewed and classified according to criteria which we have presented. Only six of these cases, including the present case, represent true aplasia, manifested by total blindness and complete absence of the optic disc and retinal vessels.

Blindness↗

PubMedDate not supplied

Treatment of intravitreal and prepapillary neovascularization following branch retinal vein occlusion.

Ten eyes which had developed retinitis proliferans following branch retinal vein occlusion were treated with xenon photocoagulation utilizing an ablative technique limited to the effected retinal quadrants. In eight of the ten eyes, complete regression of the vessels was obtained, as evidenced by nonfilling on subsequent fluorescein angiography. The remaining two eyes showed significant but incomplete closure. There were no postoperative vitreous hemorrhages, no significant permanent complications, and the visual acuity remained at or better than pretreatment levels in all cases. In conclusion, we wish to reemphasize the limited scope of this report. The series, though consecutive, is small and the follow-up period relatively short. On the basis of the cases presented here, we believe that continued investigation using this mode of treatment is warranted, and that this method may prove to be of significant value in the management of complicated retinal branch vein occlusion.

Adult↗