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Biomedical subjects

J G Heathcote

Publications and source records attributed to J G Heathcote.

At least 19 recordsLinked to original sources
PubMed2003

Osteoblastoma of the clavicle.

A 14-year-old female with a 1-year history of a painful clavicle mass underwent resection and reconstruction with an intercalated autograft and rigid plate fixation. The histopathology was diagnostic for osteoblastoma. Although a clavicle mass is a common entity following clavicle trauma, less common disorders such as bone tumors need to be considered in the differential diagnosis. Osteoblastoma is an uncommon, benign bone tumor representing 1% of all primary bone tumors. An extensive review of the literature reveals only one reported case of clavicular osteoblastoma.

Adolescent↗
PubMed2000

Iris lymphoma in a pediatric cardiac transplant recipient: clinicopathologic findings.

PURPOSE: To report the unusual presentation of a confirmed iris lymphoma in the setting of posttransplant lymphoproliferative disorder. DESIGN: Case report with clinicopathologic findings. METHODS: The medical record was reviewed for clinical manifestations, course of disease, and pathologic and radiologic findings. RESULTS: A 4-year-old girl who had undergone a cardiac transplant at 3 months of age was found to have unilateral iris lesions associated with granulomatous uveitis. Her condition was unresponsive to local and systemic steroids, so she underwent an iris biopsy that was found to contain a B cell-derived monoclonal lymphoproliferation. Treatment with systemic chemotherapy including cyclophosphamide and prednisone resulted in a transient, partial response. Localized radiotherapy induced total regression of the iris lesions. She continues to be observed and has been free of recurrence or metastasis for the past 12 months. CONCLUSIONS: Because of the increased use of organ transplantation, eye care specialists should consider the diagnosis of intraocular lymphoma when confronted with uveitis-like syndrome unresponsive to topical steroid therapy. Although there are numerous treatment options for intraocular lymphoma, radiation therapy was found to be effective in the treatment of this case.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Erdheim-Chester disease: two cases of orbital involvement.

Erdheim-Chester disease (ECD) is an increasingly recognised form of fibro-inflammatory process characterised by xanthomatous histiocytes containing large amounts of ingested lipid, plasma cells, macrophages and Touton-type giant cells. Ophthalmic involvement in ECD has been reported in only 22 cases. We describe two patients, one presenting with diabetes insipidus and subsequently developing orbital pseudotumours and retroperitoneal fibrosis, the other presenting with exophthalmos and diplopia. The first patient was treated with cladribine and subsequently developed sudden onset of bilateral blindness while the second required radiation therapy for the retro-orbital process and developed radiation retinopathy. These cases typify the variable presentation and course in patients with ECD.

Diplopia↗
PubMed2000

Expression of vascular endothelial growth factor in uveal melanoma and its correlation with metastasis.

AIMS: To evaluate the expression of vascular endothelial growth factor (VEGF) in uveal melanomas and correlate its presence with tumour characteristics and systemic metastasis. METHODS: 47 cases of ciliochoroidal melanoma enucleated between 1983 and 1993 were retrieved from the pathology archives at the University of Western Ontario. Paraffin sections stained with haematoxylin and eosin, periodic acid Schiff, and periodic acid Schiff without haematoxylin after bleaching of melanin were examined. The expression of VEGF protein was examined by an immunoalkaline phosphatase method following antigen retrieval, using an antibody to VEGF and vector red as the chromogen. The intensity of VEGF immunoreactivity was graded on a scale of 0-7 and correlated with tumour cell type, tumour size, presence or absence of necrosis, pigmentation, mitotic activity, microvascular density, and microvascular pattern. RESULTS: VEGF immunoreactivity was present in 44/47 tumours (94%): the intensity was graded as very weak (1-2) in 29/47 (62%) and as weak or greater in 15/47 (32%). VEGF was also found in the ciliary epithelium, smooth muscle of the ciliary body and iris, retinal ganglion cells, inner photoreceptor segments, and the retinal pigment epithelium. Follow up data were available in 43/47 patients (91.5%), with a median follow up time of 10 years. 16/43 (37%) patients developed metastases. VEGF expression in melanoma was linked to the presence of tumour necrosis and the degree of pigmentation but no statistically significant relation with microvascular pattern, tumour size, or microvascular density was found. There was no statistically significant correlation between VEGF expression and metastasis. CONCLUSIONS: Most ciliochoroidal melanomas express VEGF and expression is correlated with the presence of necrosis but not with the occurrence of systemic metastasis or tumour angiogenesis.

Adult↗
PubMed1996

Focal posttraumatic choroidal granulomatous inflammation.

PURPOSE: This study was performed to describe the clinicopathologic features of a group of patients with posttraumatic unilateral focal choroidal granulomatous inflammation. METHODS: Enucleated eyes with focal choroidal granulomatous inflammation without clinical signs of contralateral ocular inflammation were identified. Clinical and pathologic features were recorded. RESULTS: Six enucleated eyes that had been injured by projectiles had focal uveal granulomatous inflammation of the posterior choroid. Four eyes had uvea attached to or incarcerated into the wound. Two eyes had foreign material associated with the granulomatous inflammation, and two eyes had a disrupted lens with lens-induced inflammation. Two eyes exhibited the focal granulomatous inflammation at the site of a choroidal rupture. None of the six enucleated eyes contained Dalen-Fuchs' nodules. CONCLUSIONS: Focal choroidal granulomatous inflammation may occur as a result of penetrating ocular trauma. The origin of this condition is unknown, although it likely represents a reaction to a foreign body.

Adolescent↗
PubMed1996

Cyanoacrylate tissue adhesive in blepharoplasty.

This article reports the results of an animal study designed to evaluate the usefulness of butyl 2-cyanoacrylate (Histoacryl) in blepharoplasty skin closure. Bilateral upper and lower lid blepharoplasty skin incisions were made on seven pigs. We compared the wounds closed with 6.0 nylon to those closed with Histoacryl at 1, 2, 4, and 9 weeks postoperatively. The tensile strength of the "glued" incisions was significantly greater than that of the sutured incisions only at the 9-week postoperative interval (p < 0.05). There was no significant difference in bond strength, however, between the two methods at 1, 2 and 4 weeks postoperatively. Histopathologic analyses of sutured and glued wounds were compared at the same designated postoperative periods. No deleterious effects were found in the overall healing of the cutaneous wounds closed with Histoacryl.

Analysis of Variance↗
PubMed1994

Epithelioid sarcoma of the orbit.

BACKGROUND: Epithelioid sarcoma is a rare and aggressive malignancy commonly occurring in the tendon sheaths of the distal extremities of young adults. This article presents the clinical and pathologic details of two patients with epithelioid sarcoma in the orbit, the first to be reported as occurring in this location. METHODS: The clinical history, results of physical and radiologic examination, surgical procedures, pathologic specimens, and clinical course of each patient were reviewed and recorded. RESULTS: Biopsies were performed of the masses that were found in the superotemporal orbit of both patients. Results of pathologic examination in each patient caused considerable difficulty, and the correct diagnosis was reached only after extensive consultation. The first patient underwent wide soft tissue and bone exenteration and is alive without recurrence at 3 years. The second patient had multiple recurrences and died of recurrent and metastatic disease at 29 months. CONCLUSIONS: Epithelioid sarcoma must be added to the differential diagnosis of orbital sarcomas. The histology is nodular with a pseudogranulomatous appearance. Based on our limited experience, epithelioid sarcoma of the orbit may have a course similar to that which occurs elsewhere in the body, requiring aggressive surgical treatment at the outset.

Adolescent↗
PubMed1994

The ocular pathology in Leber's congenital amaurosis.

PURPOSE: To present the ocular pathology of a three-year-old child with Leber's congenital amaurosis (LCA) who died from an unrelated episode of presumed viral meningitis. METHODS: Autopsy was performed, and in addition the globes were harvested for pathological examination. Before the child's death, known systemic disorders with infantile retinal dystrophy were excluded. RESULTS: The outer nuclear layer and photoreceptor layers are the primary site of retinal pathology in LCA. CONCLUSION: This report of the pathological findings in LCA, early in the natural history of the disease, indicates that process appears to be a degeneration rather than an agenesis.

Blindness↗
PubMed1994

Deformation of the lamina cribrosa by elevated intraocular pressure.

The purpose of this study was to determine the mechanical response of the lamina cribrosa (LC) to elevated intraocular pressure (IOP) so as to identify possible mechanisms of optic nerve damage in early glaucoma. Ten pairs of normal human eyes were fixed after 24 hours' exposure to 50 mm Hg pressure (experimental eyes) or 5 mm Hg pressure (contralateral control eyes). Photomicrographs of the central region of the optic nerve head (ONH) were taken to examine the LC morphologically and to measure the dimensions of the LC. It was found that elevated IOP caused the LC to deflect posteriorly without affecting its thickness. The majority of the posterior displacement in the LC occurred near the periphery of the ONH. This shape change is consistent with a model of force distribution within the LC in which shear stresses are dominant; such stresses are maximal at the periphery and minimal at the centre of the ONH. These findings support a model in which mechanical forces, specifically shearing stresses within the peripheral lamina, play a direct role in the pathology of glaucomatous optic neuropathy.

Aged↗
PubMed1994

Depot drug delivery system for 5-fluorouracil after filtration surgery in the rabbit.

We investigated the potential value of 50:50 poly (DL glycolic acid-lactic acid) (PGLA) copolymer as a degradable depot delivery system for 5-fluorouracil (5-FU) after filtration surgery. Analysis of retrieved discs after implantation in 22 eyes of 22 pigmented rabbits showed a dual drug release profile and polymer mass loss characteristics. In a second group of pigmented rabbits implantation of PGLA discs impregnated with 5-FU (22 eyes) significantly lengthened the survival time of filtration fistulae compared with discs without 5-FU (18 eyes) or no disc (10 eyes) (p < 0.0001). Use of PGLA copolymer impregnated with 5-FU could prove valuable for patients undergoing glaucoma filtering surgery.

Animals↗
PubMed1994

Ocular toxicity of mitomycin C and 5-fluorouracil in the rabbit.

We studied the histotoxic effects of mitomycin C and 5-fluorouracil (5-FU) in the eyes of New Zealand white rabbits using light microscopy. Twenty-four eyes of 24 rabbits received subconjunctival injections of mitomycin C (0.025, 0.05, 0.10, 0.20, 0.40 or 0.80 mg/mL) or 5-FU (10.0 mg/mL), either alone (0.25 mL) or in combination with anterior chamber injections (0.05 mL), once daily for 4 consecutive days. Two eyes of two rabbits received subconjunctival and anterior chamber injections of unpreserved sterile saline. The eyes were examined regularly for external signs of toxicity and were enucleated 4 weeks after the last injection. Mitomycin C produced considerable tissue damage in the anterior segment, the severity being related to both the concentration and the route of administration. Eyes that received both subconjunctival and anterior chamber injections showed more damage than those that received subconjunctival injections alone. At the highest concentration of mitomycin C the cornea was inflamed, with stromal necrosis and marked endothelial loss. Hemorrhagic iris necrosis was also seen. In contrast, the 5-FU-treated eyes showed no microscopic evidence of toxicity. We conclude that there is greater risk of toxic anterior segment effects when mitomycin C is used as adjunctive therapy following filtration or pterygium surgery.

Animals↗