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Biomedical subjects

J A Schulman

Publications and source records attributed to J A Schulman.

At least 19 recordsLinked to original sources
PubMed1995

Non-neoplastic chorioretinal enhancement patterns in magnetic resonance imaging of the eye.

OBJECTIVE: To define the role of contrast-enhanced magnetic resonance imaging (MRI) as a possible adjunct to funduscopy and ultrasonography in a selected sample of non-neoplastic disorders of the chorioretina. PATIENTS AND METHODS: The study group consisted of five patients (ranging in age from 3 to 78 years) with one of the following diagnoses: ocular toxocariasis, staphyloma, glaucoma, or ocular involvement of cytomegalovirus (CMV) infection or AIDS. All of the patients underwent MRI, and the findings were correlated with those of funduscopy and ultrasonography when possible. RESULTS: There were two abnormal MRI enhancement patterns, one with and the other without major distortion of the chorioretina. Areas of abnormal enhancement correlated well with the funduscopic findings. For the patient with CMV infection and the one with AIDS, who were not examined with ultrasonography, MRI showed subtle chorioretinal abnormalities. In the other three cases, for which both ultrasonography and MRI were performed, the findings of the two methods correlated well. CONCLUSIONS: Ultrasonography remains the imaging modality of choice in the work-up of most ocular abnormalities. Ultrasonography, MRI and computed tomography are recommended when funduscopy is technically not possible. Because contrast-enhanced MRI is often performed to define the remainder of the orbit, as well as extra-orbital structures, and because of its capability to demonstrate abnormalities of the chorioretina, this modality may serve as a useful adjunct to ultrasonography. Further studies are needed to compare the efficacy of contrast-enhanced MRI and ultrasonography in the evaluation of small, nonneoplastic lesions of the chorioretina.

Adult↗
PubMed1993

Management of giant retinal tears with perfluoroperhydrophenanthrene (Vitreon).

Giant retinal tears in 10 eyes were repaired with the perfluorocarbon liquid Vitreon (perfluoroperhydrophenanthrene). The mean patient follow-up period was 9.2 months; retinas remained attached in all eyes at the last examination. Visual acuity improved in 9 eyes and could not be measured in one eye. One patient (mentally retarded) required a second operation for reattachment of the retina, which redetached from trauma after initial successful repair. Vitreon, unlike other perfluorocarbon liquids, may also be used as a short-term intraocular tamponade with the patient remaining in a supine position postoperatively. Vitreon was used as a short-term postoperative intraocular tamponade in 6 eyes. In 4 eyes, Vitreon was used as an intraoperative tool to reposition the retina and, when necessary, to unfold an inverted flap.

Adolescent↗
PubMed1992

Intravitreal corticosteroids as an adjunct in the treatment of bacterial and fungal endophthalmitis. A review.

The use of intravitreal corticosteroids in the management of endophthalmitis remains controversial. Several clinical and experimental reports are reviewed that suggest that intravitreal corticosteroid therapy, when used in conjunction with antibiotics with and without vitrectomy, reduces the intraocular inflammatory process and secondary complications associated with microbial endophthalmitis.

Animals↗
PubMed1991

Ocular toxicity of experimental intravitreal itraconazole.

We investigated itraconazole, a new triazole antifungal agent that poorly penetrates ocular tissues after oral administration. We injected itraconazole in doses from 10 to 100 micrograms dissolved in 100% dimethyl sulfoxide into the eyes of New Zealand rabbits. Ocular toxicity studies performed five weeks after administration showed no substantial retinal or histopathologic changes in eyes injected with either 100% dimethyl sulfoxide or 10 micrograms of itraconazole. Higher doses caused focal areas of retinal necrosis. Our results indicated that intravitreal doses of 10 micrograms or less of itraconazole may be beneficial in the treatment of fungal endophthalmitis.

Animals↗
PubMed1989

Toxicity of intravitreal oxiconazole.

Oxiconazole, a new imidazole derivative, has a broad antifungal spectrum in vitro and in vivo. Adult New Zealand white rabbits were injected intravitreally with doses ranging from 10 to 100 micrograms of this drug. Eyes were evaluated with preoperative and postoperative biomicroscopy and indirect ophthalmoscopy, electroretinography, and light microscopy. From these data, it was determined that an intravitreal injection containing a concentration of up to 100 micrograms per 0.1 milliliter of oxiconazole was nontoxic to the rabbit eye.

Animals↗
PubMed1989

Toxicity and clearance of a combination of liposome-encapsulated ganciclovir and trifluridine.

New Zealand albino rabbits were given intravitreal injections of liposome-encapsulated ganciclovir and trifluridine. Preoperatively and postoperatively, the eyes were evaluated by indirect ophthalmoscopy at different time intervals up to 14 days after injection. At intervals up to 14 days postinjection, the animals were sacrificed, the eyes enucleated, vitreous antiviral levels determined in one group of eyes, and histopathological examination conducted in the other group. The results of this study demonstrated prolonged intravitreal drug levels above the mean inhibitory dose for many strains of virus belonging to the herpes simplex virus family. No evidence of gross retinal toxicity was found by clinical or light microscopic examination of the treated eyes.

Animals↗
PubMed1989

Intravitreal drug therapy.

The treatment of many ocular disorders is hampered because of poor penetration of systemically administered drugs into the eye. The tight junctional complexes (zonulae occludens) of the retinal pigment epithelium and retinal capillaries are the site of the blood-ocular barrier. This barrier inhibits penetration of substances, including antibiotics, into the vitreous. Over the last 18 years we have evaluated the nontoxic doses of various drugs. These include antibiotics and antifungals for treatment of bacterial and fungal endophthalmitis, antivirals for treatment of viral retinitis (specifically, when medication with these drugs poses the threat of toxicity to other organs). Intravitreal antineoplastic drugs have been studied to prevent cell proliferation in the vitreous cavity after retinal attachment surgery, which can lead to proliferative vitreoretinopathy (PVR). Furthermore, we evaluated the anti-inflammatory action of dexamethasone and cyclosporine A to reduce intraocular inflammation after intraocular surgery or in uveitis. Because these studies had been performed in the presence of the vitreous, which can slow down the diffusion of the drugs toward the retina, it was necessary to reevaluate the concentration of drugs which could be administered intravitreally in the vitrectomized eye. The nontoxic dose of numerous drugs when added to vitrectomy infusion fluid has also been evaluated. Furthermore, the role of vitrectomy in the treatment of bacterial fungal endophthalmitis has been studied and the role of vitrectomy in this ocular disorder is defined.

Animals↗
PubMed1989

Syphilitic gummatous iridocyclitis.

We present a rare case of gummatous syphilitic iridocyclitis. The differential diagnosis, clinical characteristics, and treatment of this ocular disease are discussed.

Adult↗
PubMed1989

Ocular toxicity after intravitreal injection of terconazole.

Terconazole, a new triazole antifungal agent, was injected intravitreally in doses ranging from 10 to 100 micrograms dissolved in dimethyl sulfoxide (DMSO) 60% into the eyes of New Zealand rabbits. Three control eyes received only DMSO. The eyes were evaluated with biomicroscopy, indirect ophthalmoscopy, electroretinography, and histopathologic examination. From these data, it was determined that an intravitreal injection containing a concentration of 10 micrograms/0.1 mL of terconazole is not toxic to the rabbit eye.

Animals↗
PubMed1988

Toxicity of intravitreal injection of foscarnet in the rabbit eye.

Foscarnet (sodium phosphonoformate) is an antiviral with a high degree of efficacy against members of the herpes simplex virus family. We studied the toxicity of single doses of intravitreally administered foscarnet in the albino rabbit. Eyes were evaluated clinically and by light microscopy. Data demonstrated that doses ranging from 20 to 1000 micrograms per 0.1 milliliter are nontoxic to the retina, suggesting that foscarnet may be useful in the treatment of acute retinal necrosis and cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome.

Animals↗
PubMed1988

Fatal disseminated cryptococcosis following intraocular involvement.

A 33-year-old man was treated with systemic steroids for a retinal inflammatory lesion before the diagnosis of cryptococcal retinitis and meningitis was suspected. He died from central nervous system disease despite treatment with parenteral antifungals. Histopathological studies demonstrated ocular and disseminated systemic infection with Cryptococcus neoformans. Direct cryptococcal involvement of the eye is rare and is usually associated with disseminated disease. Systemic steroids must be used with caution, and patients who take these drugs require frequent monitoring.

Adult↗
PubMed1988

Management of viral retinitis.

Cytomegalovirus, herpes simplex, and herpes zoster are responsible for the majority of cases of viral retinitis. Herpes zoster also has been strongly incriminated as a causal agent in acute retinal necrosis. Effective chemotherapy exists for retinitis caused by herpes simplex and herpes zoster, along with acute retinal necrosis. Conventional antiviral therapy and immunomodulators are ineffective in the treatment of cytomegalovirus retinitis in patients with acquired immune deficiency disorder. Ganciclovir, a new antiviral agent, has significantly reduced visual morbidity in these patients. Recurrence of the infection is not uncommon while patients are on the drug or when the agent is discontinued, because ganciclovir is virostatic and does not stop viral replication in the retina. The inability to control this viral retinitis using presently available chemotherapy indicates a need to examine other therapeutic modalities.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Intravitreal injection of liposome-encapsulated ganciclovir in a rabbit model.

The authors determined the intravitreal clearance of liposome-encapsulated ganciclovir. Liposome-encapsulated ganciclovir (84.1 micrograms/0.1 ml) was injected into the vitreous cavity of New Zealand rabbits, which were killed at 24 hours and 7, 14, and 28 days after injection. Total ganciclovir concentrations in the vitreous, up to 28 days, were higher than ID50 (50% inhibitory dose) for different clinical and laboratory strains of viruses belonging to the herpes simplex family.

Acyclovir↗
PubMed1987

Toxicity of intravitreal injection of fluconazole in the rabbit.

Fluconazole is a new bis-triazole derivative proven highly effective against Candida in various animal models. To determine its potential use in exogenous fungal endophthalmitis, 13 New Zealand white rabbits were given intravitreal injections of up to 100 micrograms/0.1 mL of the antifungal. All eyes underwent biomicroscopy, ophthalmoscopy and electroretinography before and after the procedure. No evidence of toxic intraocular effects was detected with these techniques or on light microscopy, performed 8 days after injection. The results suggest that fluconazole has potential application in the treatment of exogenous fungal endophthalmitis.

Animals↗
PubMed1981

Golgi cells of the cerebellum are inhibited by inferior olive activity.

Golgi cells of the cerebellar cortex are inhibited by activation of the inferior olive by direct electrical stimulation, or by appropriate peripheral stimulation. The strength of the inhibition is correlated with the intensity of inferior olive activation. These results indicate that the olivocerebellar inhibition of Purkinje cells is probably not mediated by the Golgi cells, and suggest previously undetected effects of the inferior olive on cerebellar cortical information processing.

Animals↗
PubMed1981

Salmon-patch hemorrhages after central retinal artery occlusion in sickle cell disease.

In two patients with sickle cell disease (one hemoglobin SC and one hemoglobin SS), central retinal artery occlusions developed. In one case, the occlusion followed a retrobulbar injection of lidocaine hydrochloride. Although the central retinal artery reperfused in each patient, many secondary peripheral retinal arteriolar occlusions remained. During the subsequent days, multiple salmon-patch hemorrhages developed in the distribution of these occluded arterioles. In one patient, the salmon-patch hemorrhages evolved into atrophic schisis cavities. These unusual cases allowed us to document the origin of salmon-patch hemorrhages after peripheral retinal arteriolar occlusions. The development of the hemorrhages was a delayed phenomenon that occurred hours to days after the initial vascular occlusion. Reperfusion of the damaged ischemic vessels with a blowout of the wall of the vessels seems the most likely explanation for this phenomenon.

Adult↗
PubMed1981

Anatomical distribution and physiological effects of enkephalin in rat inferior olive.

The opioid peptide enkephalin was evaluated as a possible synaptic transmitter in the inferior olivary complex using anatomical and physiological techniques. With standard immunohistochemical procedures, fibres and terminals containing enkephalin-like immunoreactivity were found to be heterogenously distributed in the inferior olive of the rat. Enkephalin-like immunoreactivity was found in the medial and dorsal accessory nuclei, but was sparse in the principal nucleus. Iontophoresis or pressure microapplication of Leu5-enkephalin, or a peptidase-resistant enkephalin analogue, depressed both spontaneous and amino acid-evoked firing of inferior olivary complex cells. The effect appeared to be postsynaptic, since the excitatory effects of iontophoretically-applied DL-homocysteic acid were suppressed. No selective effect on a calcium-mediated component of the action potential was seen. We conclude that enkephalin may act as a neurotransmitter or neuromodulator at afferent synapses in the inferior olive.

Amino Acids↗