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Biomedical subjects

J D Cameron

Publications and source records attributed to J D Cameron.

At least 91 records · Page 5Linked to original sources
PubMed1986

S-antigen-specific rat T cell lines recognize peptide fragments of S-antigen and mediate experimental autoimmune uveoretinitis and pinealitis.

Two S-antigen-specific rat T cell lines expressing the T helper cell surface phenotype (W 3/25+, OX 8-) have been isolated from the spleen and lymph node cells of retinal S-antigen-immunized Lewis rats, one of which displayed neither clinical nor histopathologic signs of experimental autoimmune uveoretinitis. The other rat had recovered from severe experimental autoimmune uveoretinitis for 2 mo before isolation of the cell line. Both lines are specific for S-antigen presented by histocompatible antigen-presenting cells, and also respond in vitro to several of the peptides produced by cyanogen bromide cleavage of bovine retinal S-antigen. The lesions induced by the i.v. transfer of from 1 to 10 X 10(6) viable line cells involve the retina and pineal gland, as is found when Lewis rats are immunized with immunopathogenic doses of S-antigen. Histologic examination of the eyes and pineal glands revealed pathologic lesions typical of experimental autoimmune uveoretinitis, and consisted of marked infiltration of the retina and surrounding tissues and the pineal gland by lymphocytes and inflammatory cells. T cells capable of mediating autoimmune disease are clearly present and readily isolated from both asymptomatic and convalescent animals. No significant differences in specificity for the cyanogen bromide peptides of S-antigen or cell surface phenotype were found in the T cell lines isolated from these two rats, nor was any difference found in the specificity or titer of serum antibodies taken from the original rats for the cyanogen bromide peptides of S-antigen.

Animals↗
PubMed1986

Embryonal rhabdomyosarcoma of the conjunctiva. A clinicopathologic and immunohistochemical study.

Rhabdomyosarcoma of the conjunctiva is a rare lesion, with few previously reported cases. We have observed such a tumor occurring in a 16-year-old girl. The clinical and pathologic entities to be considered in differential diagnosis in such cases are several; in this circumstance, immunohistologic reactivity for desmin and myoglobin (two muscle-related proteins) allows a definitive interpretation of rhabdomyosarcoma to be made. This article documents the clinicopathologic features of the epibulbar rhabdomyosarcoma seen in our patient and discusses the immunocytochemical characteristics of myogenic tumors in general, in the context of ocular neoplasia.

Adolescent↗
PubMed1986

Polysulfone corneal lenses.

Polysulfone is a thermoplastic compound first synthesized in 1965. A unique characteristic of polysulfone is its high refractive index (1.633), which allows very thin optical lenses to be manufactured. Over the last five years, D. Peter Choyce has surgically implanted over 40 polysulfone lenses into eyes of his patients. Analysis of his data indicates that polysulfone intraocular lenses are capable of correcting large refractive errors. Based on his work, a multicenter study was undertaken to evaluate the safety and efficacy of polysulfone as an intracorneal lens material in laboratory models. Four monkeys, eight baboons, and 24 cats were used as laboratory models; 5.0-mm to 6.0-mm diameter hyperopic (+28.5 diopter) and myopic (-17.0 and -25.5 diopter) lenses were surgically implanted within the corneal stroma in one eye of each of the laboratory models while a sham lamellar dissection was performed in the other eye. One hundred percent (4/4) of monkey eyes, 12.5% (1/8) of baboon eyes, and 70.0% (18/24) of cat eyes maintained clear media by ophthalmoscopic examination at follow-ups ranging from three to six months. Complications included both visually and nonvisually significant interface opacities, lens extrusion, anterior corneal necrosis, refractile particles, and epithelial thinning.

Animals↗
PubMed1986

Ocular histopathology of acrodermatitis enteropathica.

Acrodermatitis enteropathica is the clinical expression of congenital zinc deficiency and is now treated with supplemental zinc. This report details the ocular histopathology of a child who died before efficacious treatment was available. The findings include corneal epithelial thinning and loss of polarity, anterior corneal scarring and loss of Bowman's membrane, cataract formation, ciliary body atrophy, retinal degeneration, RPE depigmentation, and optic atrophy.

Acrodermatitis↗
PubMed1985

Intraocular retinoblastoma group V: an analysis of prognostic factors.

A retrospective analysis of the University of Minnesota (Minneapolis) experience with retinoblastoma is presented. Seventy-five patients were diagnosed with retinoblastoma between 1958 and 1983, of which 53 (71%) had at least one Reese-Ellsworth group V eye. Nineteen group V patients and one group II patient developed extraocular disease recurrence. The cumulative actuarial rate of recurrence at 12 years was 36% for patients with group V disease. The median time from diagnosis to recurrence for unilateral patients was seven months and for bilateral patients 28 months (P = .001). Patients developing extraocular disease had a 10-year actuarial survival rate postrecurrence of 34%. The four long-term survivors of extraocular recurrences had had isolated orbital or local soft tissue recurrences only. Features of group V patients associated with extraocular recurrences were identified by univariate life table analyses. Clinical poor-risk factors included the nongenetic form of the disease (P = .03) and male sex (P = .02). Pathologic poor risk factors included rubeosis (P = .01), undifferentiated histology (P = .03), large tumor size (P = .05), and intraocular extension to the anterior segment (P = .02), retinal pigment epithelium (P = .03), choroid (P less than .001), and optic nerve beyond the lamina cribrosa (P = .02). Treatment-associated poor-risk factors included an optic nerve length of less than 5 mm removed at enucleation (P = .003). Multivariate life table analyses demonstrated the following parameters to be independent poor-prognostic factors: optic nerve length of less than 5 mm removed at enucleation (P = .001), optic nerve involvement (P = .004), and large tumor size (P = .01). These results will help to identify patients with retinoblastoma who are at greatest risk for extraocular recurrence.

Actuarial Analysis↗
PubMed1984

The clinical implications of bilateral microphthalmos with cyst.

An infant with bilateral congenital microphthalmos with cyst developed neurologic and cardiac abnormalities that resulted in her death at the age of 7 months. When she was first examined, the cystic masses in both eyes transilluminated and were easily deformable. No ocular structures could be identified. Bilateral microphthalmos with cyst appears to be associated with major systemic abnormalities whereas unilateral microphthalmos with cyst is associated with much less serious systemic abnormalities.

Cysts↗
PubMed1984

Retinal vascular changes in malignant melanoma of the choroid.

A review of fluorescein angiograms from 41 patients with malignant melanoma of the choroid showed that 11 patients (27%) had evidence of retinal vascular abnormalities. Abnormal retinal capillaries were found in eight cases, areas of capillary nonperfusion in seven cases, and microaneurysms in four cases. Lipid exudation, retinal neovascularization, and arteriovenous communication were noted in one case each. Histopathologic studies in eight cases showed extensive degeneration of the overlaying retina in all eight cases and extension through Bruch's membrane by the tumor in four cases. Abnormal capillary architecture was demonstrated by trypsin digest preparations from four cases.

Adult↗
PubMed1984

Electron microscopic study of corneal epithelial-endothelial interactions in organ culture.

The interactions between rabbit corneal epithelium and endothelium were investigated in an organ culture model using scanning electron microscopy and correlative light microscopy. Following mechanical removal of corneal endothelium, corneal epithelium was observed to migrate across the cut surface of the corneal stroma and onto the denuded Descemet's membrane after 48 hours in organ culture. By 72 hours, a distinct line of contact between the migrated epithelium and endothelium was established. Following epithelial-endothelial contact, no cellular migration occurred. Corneal endothelial inhibition of epithelial migration may be a major factor in the prevention of surface epithelial invasion and proliferation following surgery and trauma.

Animals↗
PubMed1983

Cellulose acetate impressions of the ocular surface. Dry eye states.

Cellulose acetate impressions of the ocular surface were obtained for normal eyes, eyes with blepharoconjunctivitis, eyes with keratoconjunctivitis sicca, and eyes with primary ocular surface disease. Normal eyes and eyes with blepharoconjunctivitis had morphologically normal epithelium and goblet cells on the bulbar and palpebral ocular surfaces. Eyes with primary ocular surface disease had abnormal ocular surface impressions (decreased, abnormal, or absent goblet cells with abnormal epithelial cells) on both the bulbar and palpebral ocular surfaces. Conversely, eyes with keratoconjunctivitis sicca had substantial abnormalities of the epithelium and goblet cells only on the bulbar ocular surface, suggesting an environmental role in this disease process.

Adult↗
PubMed1983

Angiolymphoid hyperplasia with eosinophilia (Kimura's disease) of the orbit and ocular adnexa.

We conducted a clinicopathologic study of eight cases of angiolymphoid hyperplasia with eosinophilia (Kimura's disease). The orbit was involved in five patients and the ocular adnexa (eyelid and inner canthus) in three. The median age of the six men and two women was 51 years (range, 38 to 72 years). The lesions were characterized by an abnormal proliferation of small vessels lined by plump endothelial cells, associated with a chronic inflammatory infiltrate with prominent tissue eosinophilia and scattered lymphoid follicles. Serial sectioning of two tumors disclosed that these small vessels apparently originated within the walls of arteries. Immunohistochemistry disclosed factor VIII-related antigen within the endothelial cells in two of the four lesions studied. Ultrastructurally, some of the capillaries showed prominent multilaminar basement membranes surrounding their walls. The apical surface of the markedly swollen endothelial cells disclosed broad villous processes protruding into the lumen. Although this vascular lesion can be mistaken for angiosarcoma, it is considered benign. There was no evidence of recurrences of any of the six of the seven lesions that were completely excised and followed up (follow-up periods ranged from five to 95 months). Complete surgical excision appears to be the best treatment.

Adult↗
PubMed1983

Transcorneal extrusion of an intraocular lens.

An 82-year-old woman was treated for pseukophakic bullous keratopathy with a penetrating keratoplasty complicated by a postoperative retinal detachment. The retina was reattached successfully but impaired visual acuity remained. She was lost to follow-up for 14 months. Upon re-examination the pseudophakic lens optic had eroded completely through the donor cornea. Histologic study of the enucleated eye suggests that the intraocular lens optic came in contact with the posterior cornea after a transient wound dehiscence. The lens haptics, still attached to the optic, extended through anterior corneal scar tissue into the globe. The globe remained sterile and intact during the extrusion process. This case emphasizes the importance of selecting patients who will comply with postoperative care and the need to minimize contact between intraocular lenses and ocular tissue.

Aged↗
PubMed1982

Experimental retinal detachment. II. Role of the vitreous.

The role of the cortical vitreous in persistence of experimental retinal detachments was evaluated in cynomolgus monkeys. Detachments were created by subretinal injection of 20% autologous serum in Ringer's solution. A pars plana vitrectomy was performed on selected eyes with a Douvas vitrectomy instrument before creation of the detachment. Retinal holes were created from the subretinal side with a hooked needle or from the vitreal side with the vitrectomy instrument. The rate of reattachment of the retina was rapid and independent of retinal holes size if cortical vitreous covered the retinal hole. If no cortical vitreous covered the retinal hole, the retina remained detached indefinitely (longer than three months). A spontaneous reduction in the size of the retinal hole occurred in many eyes in association with star-fold formation. It is concluded that cortical vitreous is capable of obstructing fluid movement through the retinal hole.

Animals↗
PubMed1982

Disseminated intravascular coagulation in infancy and in the neonate. Ocular findings.

We report two cases of neonatal disseminated intravascular coagulation (DIC). One case is associated with placenta previa and respiratory distress, and the other shows hemorrhage with Gram-negative sepsis. In both cases, results of autopsy show microscopic confirmation of DIC in several body tissues. One pair of eyes demonstrates intraocular hemorrhages and intravascular fibrin in the choriocapillaris (a typical manifestation) and intravascular fibrin in the ciliary body vessels of one eye. In addition, the other pair of eyes shows involvement of iris vessels, a unique finding, as is intraretinal intravascular fibrin in one eye of the same patient.

Bacterial Infections↗
PubMed1981

Pigment dispersion syndrome: a clinical study.

This study involved a group of 407 patients (799 eyes) with pigment dispersion syndrome gathered from a glaucoma population of 9200 patients. The sex distribution was equal. The majority (65%) of patients were myopic. The incidence of retinal detachment was 6.4%. No patients were black, but 5 were mulatto. Approximately one-quarter of the patients wih pigment dispersion syndrome (31% of the men, 19% of the women) had glaucoma. The average age of onset of glaucoma was 15 years less than in control patients with chronic simple glaucoma. When both eyes were affected by glaucoma, the glaucoma was consistently more severe in the eye with the more heavily pigmented angle. The degree of iris transillumination was found to be of no importance in predicting the presence of glaucoma or the severity of trabecular pigmentation. The pressure in 66% of the eyes with pigmentary glaucoma was controlled medically. A higher percentage of patients with pigmentary glaucoma required surgery than patients in the control group with chronic simple glaucoma. Men with pigmentary glaucoma required surgery at a much earlier age than women with pigmentary glaucoma.

Adult↗
PubMed1980

Mycobacterium bovis infection of the conjunctiva.

An elderly woman from Minnesota had bilateral bulbar conjunctival nodules that proved to be caused by Mycobacterium bovis. She was found to have active military tuberculosis; only pulmonary and ocular involvement was confirmed. She had a history of tuberculosis but no recent exposure or intercurrent illness. The case was unusual in that the endogenous infection caused bilateral bulbar symptoms but no palpable lymphadenopathy and no other organ involvement. This case demonstrates many of the basic tenents on the course of tuberculosis in humans. Triple chemotherapy was administered, and the patient had a slow but definite clinical response.

Adult↗