Biosynthesis of sulphated macromolecules by rabbit lens epithelium. I. Identification of the major macromolecules synthesized by lens epithelial cells in vitro.

Rabbit lens epithelial cells synthesize and secrete a variety of [35S]sulphate-labeled glycoconjugates in vitro. Associated with the cell layer, and with the medium, was a high molecular weight glycoconjugate(s) that contained heparan sulphate which was apparently covalently linked to sulphated glycoprotein. This component(s) was eluted in the void volume of a Sepharose CL-2B column and could not be fractionated by detergent treatment or extraction with lipid solvents. The cell layer also contained glycosaminoglycans (72% heparan sulphate, 28% chondroitin sulphate), as well as a small proportion of a low molecular weight sulphated glycoprotein. The major 35S-labeled species secreted into the medium were sulphated glycoproteins with approximate molecular weights of 120,000 and 35,000 together with a heparan sulphate proteoglycan. This proteoglycan could be precipitated from the culture medium with 30% saturated (NH4)2SO4 and eluted from Sepharose CL-4B columns at approximately the same position (Kav = 0.15) as heparan sulphate proteoglycans described in the basement membrane of the EHS "sarcoma" (Hassell, J. R., P. G. Robey, H. J. Barrach, J. Wilczek, S. I. Rennard, and G. R. Martin, 1980, Proc. Natl. Acad. Sci. USA, 77:4494-4498) and of the mouse mammary epithelium (David, G., and M. Bernfield, 1981, J. Cell Biol., 91:281-286). Its presence in the culture medium was unanticipated but may be explained by the inability of these cultures to deposit a basement membrane when grown on a plastic surface. The relationship of this heparan sulphate proteoglycan to the lens epithelial basement membrane is the subject of the following paper.

Biosynthesis of sulphated macromolecules by rabbit lens epithelium. II. Relationship to basement membrane formation.

Rabbit lens epithelial cells display a similar "cobblestone" morphology and produce the same complement of sulphated macromolecules (also see Heathcote, J.G., and R.W. Orkin, 1984, J. Cell Biol., 99:852-860) whether grown on plastic or glass, dried films of gelatin or type IV collagen with laminin, or on gels of type I collagen. There was no evidence of basement membrane formation by these cells when they were grown on plastic, glass, or dried films. In contrast, cultures that had been grown on gels deposited a discrete basement membrane that followed the contours of the basal surfaces of the cells and in addition, they secreted amorphous basement membrane-like material that diffused into the interstices of the gel and associated with the collagen fibrils of the gel. A significant proportion (approximately 70%) of the heparan sulphate proteoglycan fraction that was secreted into the culture medium (fraction MI) when the cells were grown on plastic became associated with the cell-gel layer in the gel cultures. Further, when basement membrane was isolated by detergent extraction, greater than 90% of the 35S-labeled material present was in this heparan sulphate proteoglycan.

A spindle-cell myoepithelioma of the lacrimal gland.

A middle-aged woman developed unilateral, painless proptosis that increased slowly over 1 year. A clinical diagnosis of pleomorphic adenoma of the lacrimal gland was supported by computed tomographic scanning and the tumor was excised. On histological examination the tumor proved to be a benign, myxoid myoepithelioma of spindle-cell type. Although occasionally seen in the salivary glands, to our knowledge, this tumor has not previously been described in the lacrimal gland.

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.

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.

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.

Multicentric reticulohistiocytosis: a report of a case and a review of the pathology.

A case of multicentric reticulohistiocytosis (MR) in a 24-yr-old woman is presented. MR is a rare disorder characterized by progressive polyarthropathy and a papulo-nodular skin rash. The diagnosis was established by histological examination of biopsies of erythematous nodules on the fingers which showed circumscribed collections of large mononuclear cells and multinucleate giant cells in the reticular dermis. These were embedded in a fine network of mature fibrous tissue with a scanty lymphocytic infiltrate. Histochemical, immunopathological and ultrastructural investigations confirmed that the large mononuclear cells had the properties of macrophages. The histopathological features of MR are reviewed in the light of current knowledge of macrophage physiology, and evidence for lymphocyte-histiocyte interactions in the pathogenesis of this bizarre granulomatous disorder is presented.

Diabetes mellitus in the aetiology of Dupuytren's disease.

In controlled clinical studies of adult diabetics a 42% incidence of signs of Dupuytren's disease was found. The incidence was highest in the older patients with a longer history of diabetes, but was not related to the severity of the diabetes. The features of Dupuytren's disease in the diabetics has a distinctive pattern, being more severe in men than women and, compared with controls, having a radial shift towards the middle finger. The disease was mild and of benign prognosis, rarely needing operation. In a further study, 13% of patients with Dupuytren's disease were found to have a raised blood glucose level. The question is posed as to whether the biochemical disturbance causes the Dupuytren's disease or whether the pattern of inheritance predisposes to both Dupuytren's disease and diabetes.

Persistence of intralenticular squamous epithelium after trauma.

An intralenticular foreign body with associated squamous epithelium was found incidentally at cataract extraction in a 61-year-old man 23 years after a penetrating injury. The squamous epithelium produced no adverse effects. To our knowledge this is the first report of persistence of surface squamous epithelium within the lens.

Plasma cell granuloma of the lacrimal sac.

A 31-year-old man with a 2-year history of recurrent dacryocystitis underwent dacryocystorhinostomy. An unexpected operative finding was a polyp in the lacrimal sac. Histopathological examination revealed a plasma cell granuloma. The nature of this uncommon inflammatory pseudotumour of the lacrimal sac is discussed.

Incontinentia pigmenti (Bloch-Sulzberger syndrome): a case report and review of the ocular pathological features.

Incontinentia pigmenti (IP) (Bloch-Sulzberger syndrome) is an X-linked dominant condition usually fatal in males. Shortly after birth affected girls present with a rash followed by pigmentary changes. Abnormalities of the central nervous system and dentition are often present, and ophthalmic problems develop in approximately one-third of patients. The authors present the pathological findings in the skin and eye in a young woman who required enucleation as a result of long-standing retinal detachment and closed-angle glaucoma. A review of published ocular pathology reports indicates that retinal detachment and a fibrovascular retrolental membrane are the commonest intraocular abnormalities in IP. Changes in the retinal pigment epithelium are also prominent, although whether these are primary or secondary remains to be established.

Endophthalmitis caused by exogenous nocardial infection in a patient with Sjögren's syndrome.

A 60-year-old woman receiving prednisolone therapy for Sjögren's syndrome presented with corneal perforation. Therapeutic penetrating keratoplasty was performed, but no causative organism was identified. Focal inflammatory infiltrates in both donor and host cornea and anterior uveitis developed postoperatively. Five months later the inflammation rapidly became much worse, with fulminating abscesses, and the eye was eviscerated because of severe endophthalmitis. Nocardia organisms were identified in the cornea, conjunctiva and vitreous by means of acridine orange and modified Ziehl-Neelsen stains. The infection produced both suppurative and granulomatous inflammation. Reexamination of the penetrating keratoplasty specimen with a modified Ziehl-Neelsen stain revealed a few Nocardia organisms, which suggested that infection had occurred at the time of corneal perforation.

Anterior segment mesenchymal dysgenesis associated with partial duplication of the short arm of chromosome 2.

We present a case of partial duplication of the short arm of chromosome 2 (karyotype 46,XX, dup [2p21-2p25]) in a newborn girl. The infant was born at 41 weeks of gestation and died approximately 3 hours after birth. At autopsy the characteristic dysmorphic features (hypertelorism, high, prominent forehead, micrognathia and low-set, malformed ears) and numerous other congenital malformations were observed. Bilateral microcornea with opacities was noted. Histopathological examination of the eyes showed dysgenesis of Bowman's membrane, with glycosaminoglycan deposition and a series of structural anomalies that form part of the anterior segment mesenchymal dysgenesis (ASMD) complex. To our knowledge this is the first case of partial duplication of the short arm of chromosome 2 in which the ocular histopathological features have been studied. Our case provides a further example of the association of ASMD with a chromosomal abnormality.

Further evaluation of collagen shields as a delivery system for 5-fluorouracil: histopathological observations.

Collagen shields are a potential delivery system for antifibroblast drugs such as 5-fluorouracil after filtration surgery. To determine whether collagen shields produce histologic evidence of inflammation when implanted subconjunctivally, shields were implanted into four rabbit eyes and six guinea pig eyes and retained for 7 or 14 days. Two rabbit eyes and two guinea pig eyes served as controls. Seven days after implantation in the rabbit eyes foreign-body giant cells were present at the surface of the shield, and early deposition of connective tissue was evident around the shield. The inflammatory response at 14 days was similar but more intense. In the guinea pig eyes the collagen shields induced substantially less inflammation, and there was marked shield degradation at 14 days. The results suggest that the inflammatory response in rabbits may be species specific and that collagen shields may be of value as a drug-delivery system for antifibroblast drugs in other species.

Oncocytoma of the lacrimal caruncle.

Two cases of oncocytoma of the lacrimal caruncle are presented. This benign tumour is characterized by a uniform population of epithelial cells with abundant, finely granular, eosinophilic cytoplasm. The granules stain blue with Mallorys phosphotungstic acid hematoxylin and can be identified as mitochondria by electron microscopy. An additional 35 cases from the literature are reviewed. The tumour usually occurs in people over the age of 60 years and is more common in women (male:female ratio of 1:5).

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.

Fifty:fifty poly (DL glycolic acid-lactic acid) copolymer as a drug delivery system for 5-fluorouracil: a histopathological evaluation.

Fifty:fifty poly (DL glycolic acid-lactic acid) copolymer (PGLA) is a potentially useful depot drug delivery system for 5-fluorouracil (5-FU). The purpose of this study was to evaluate the fibroinflammatory reaction induced by this polymer. Polymer discs without 5-FU were inserted subconjunctivally in one eye of each of two guinea pigs and four pigmented rabbits (control group), and discs containing 20% 5-FU were inserted subconjunctivally in both eyes of nine pigmented rabbits (study group). The tissue reaction to the copolymer did not differ between rabbits and guinea pigs, with a mild mixed inflammatory reaction 1 week after implantation. At 2 weeks a thin fibrous capsule surrounded the discs, with no change in the amount of inflammation. At 4 weeks the disc had disintegrated, but residual polymer was seen within multinucleated giant cells in the episcleral tissue. Granulation tissue and inflammatory responses were mild. Less inflammation and fibrosis occurred in the study eyes, although the pattern of response was similar in the two groups. The inflammatory response to PGLA was markedly less than that to implanted collagen shields, and our findings suggest that PGLA implant is a promising ocular drug delivery system for 5-FU after filtration surgery.

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.

Isolated eyelid edema in Melkersson-Rosenthal syndrome: a case series.

PURPOSE: To report the clinicopathologic features of a series of patients with Melkersson-Rosenthal syndrome (MRS). METHODS: Patients in this clinicopathological case series were identified through retrospective review. Five Caucasian patients (2 women and 3 men; age range, 46 to 73 years) with isolated eyelid swelling presented over an 11-month period to two Canadian tertiary Oculoplastic referral centres. All underwent clinical examination and had tissue biopsies. RESULTS: The patients presented with non-pitting, non-pruritic, painless and recurrent eyelid swelling. None had evidence of cranial nerve palsy or fissured tongue. The duration of symptoms before referral was between 1-5 years. Histopathological examination showed granulomatous inflammation in four patients. Granulomatous folliculitis was a novel finding in three patients. CONCLUSIONS: Monosymptomatic patients with MRS require a high index of suspicion. Histopathological confirmation is vital for the diagnosis.