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Biomedical subjects

Irene Pecorella

Publications and source records attributed to Irene Pecorella.

9 recordsLinked to original sources

Scleral ossification in phthisical eyes.

Heterotopic secondary ossification of the eye usually affects intraocular tissues. Although calcium deposition in the scleral lamellae is not uncommonly observed, bone formation is only rarely associated with chromosomal abnormalities or colobomatous eyes. Herein two cases of both scleral and intraocular ossification in patients with long-standing ocular phthisis are reported. The cases of idiopathic scleral ossification, albeit exceedingly rare, suggest that osteogenic precursor cells may reside in the sclera, as well and though very rarely, these cells can also be stimulated to form heterotopic bone by a traumatic or inflammatory local event.

Adult↗

Osteo-odonto-keratoprosthesis: a human model of autotransplant.

We evaluated the microscopical changes that occurred when bone and dental tissue were exposed to such a foreign environment as the ocular surface and anterior chamber in 17 osteo-odonto-keratoprostheses removed from the recipient's eye after 1 to 20 years. Histochemical methods were performed to demonstrate elastic and precursor fibers, while immunohistochemical procedures were used to study the distribution of collagen types I to VI. Islands of heterotopic, newly formed bone were observed in the dentin and the periodontal space, leading to focal dentoalveolar ankylosis. Remodelling and disappearance of the periodontal ligament was never diffuse.

Adolescent↗

Progressive replacement of oral mucosa by conjunctiva in osteo-odonto-keratoprosthesis: preliminary observations.

PURPOSE: In a Strampelli osteo-odonto-keratoprosthesis, a patch of oral mucosa is frequently used to cover the ocular surface after implantation of an osteodental lamina into the eye. In many cases, gross modifications in the eye covering become apparent a few years later. The aim of this study was to investigate the histologic findings in the clinically modified ocular surface. METHOD: Biopsies were performed in 7 patients at the junction between the osteodental acrylic lamina and surrounding modified oral mucosa, during surgery for local plastic reconstruction or positioning of antiglaucoma silicone tubes. Specimens were examined by light microscopy. RESULTS: Six of the 7 clinically modified specimens corresponded microscopically to conjunctiva. Typical oral mucosa could still be observed overlying the osteodental acrylic lamina. CONCLUSIONS: The production of local regulatory factors is a possible explanation for the survival of oral mucosa over the osteodental acrylic lamina, whereas their absence in distant areas may have induced the oral mucosa to transdifferentiate into a conjunctival-type lining. Alternatively, conjunctival regrowth from forniceal stem cells should be taken into consideration.

Acrylates↗

Diffuse granulomatous necrotizing scleritis.

CASE REPORT: A 34-year-old man presented with anterior scleral thinning in the right eye (RE) and a painful nodular scleritis in the left eye (LE). Fundus examination showed a healed vasculitis and an inferior epiretinal neovascular membrane in the LE. Topical and systemic oral steroids and antiviral medication were prescribed. One year later, optic disc hyperaemia and swelling and macular oedema became apparent in the LE. Pulsed intravenous steroids were administered for 1 year, when a nasal septum perforation and vitreous haemorrhage in the LE were diagnosed. The eye was enucleated 3.5 years after the initial complaint. Necrotizing granulomatous tissue replacing the sclera and subconjunctival granulomatous tissue were observed. Six months later, oedema and neovascularization of the right optic disc were observed and cyclophosphamide was started, with regression of the clinical signs. No systemic abnormalities have so far become apparent. DISCUSSION: Posterior scleritis is most often observed in patients with no signs of associated systemic autoimmune disease. The diagnosis in this case is most probably one of Wegener's granulomatosis (WG). In WG, the diagnosis is based on necrotizing granulomas of the respiratory tract, generalized focal necrotizing vasculitis and focal necrotizing glomerulonephritis. Eye involvement with WG has been reported in up to 58% of cases. Evaluation of the scleritis patient should include a detailed medical history, chest X-rays, blood tests, autoantibody serology and analysis of urinary sediment. Cyclophosphamide is the treatment of choice for patients with ocular manifestations of WG, polyarteritis nodosa or rheumatoid arthritis, either alone or in combination with systemic steroids. Visual loss is expected in 85% of individuals with severe necrotizing posterior scleritis.

Adult↗

Lesions caused by ricin applied to rabbit eyes.

PURPOSE: Ricin, a highly potent toxin from castor beans, is a potential biological weapon that could be dispersed in the air as dust or aerosol. In these forms, ricin, besides being inhaled, could reach unprotected eyes. The present research was performed to ascertain the lesions that the toxin causes when applied to rabbit eyes. METHODS: Ricin was applied to rabbit eyes in solution, in quantities ranging from 1 to 100 mug. Animals were observed until death, when eyes and internal organs were removed and fixed. Sections were stained and examined microscopically. RESULTS: Ricin caused inflammation of the eyes and adnexa, visible both macroscopically and histologically. The damage was greatly reduced by rinsing the eyes with 10% lactose, provided the rinsing was done almost immediately after application of the toxin. Rinsing with phosphate-buffered saline (PBS) had no effect. With the highest dosage, congestion of internal organs was also apparent. CONCLUSIONS: Application of ricin to eyes causes local damage, mainly of the inflammatory type. The ineffectiveness of rapid rinsing with PBS and the partial efficacy of rapid rinsing with lactose indicate that the toxin quickly binds to and is taken up by cells. The lesions of internal organs show that ricin applied to the eyes can be absorbed, pass into the circulation, and, at least at some dosages, damage internal organs.

Administration, Topical↗

Calcium oxalate precipitates in a renomedullary interstitial cell tumor.

We report a case of calcium oxalate deposition in a renomedullary interstitial cell tumor (RICT) in a patient dying of full-blown AIDS. The precipitates showed birefringence using a partially polaris ed light and were stained black in Yasue's silver nitrate-rubeanic acid method. The combination of calcium oxalosis and RICT has not been reported before and might possibly be due to systemic biochemical alterations of the glycosaminoglycans as a result of profound metabolic disturbances in AIDS patients.

Acquired Immunodeficiency Syndrome↗

Bilateral ocular malformations in a newborn with normal karyotype: histologic findings.

Microphthalmos with cyst is a rare condition characterized by a small globe and an inferior uveoretinal coloboma. There is also a defect in the posterior aspect of the eye through which a cyst lined by neuroectodermically derived tissue protrudes into the orbit. A case of isolated bilateral colobomatous and cystic microphthalmos is reported in an otherwise healthy child, showing no evidence of chromosomal abnormalities. Microscopic findings in the enucleated eye consisted of iris and retinal dysgenesis, ectopia lentis, persistent anterior tunica vasculosa lentis and pupillary membrane, intrachoroidal smooth muscle, and optic nerve hypoplasia. In the orbital cyst, a thick membrane reminiscent of the retinal inner limiting membrane lay between the fibroadipose and vascularised outer wall and the inner neuroectodermal lining.

Coloboma↗

An Unusual Case of Neurofibroma of the Thyroid Capsule.

A solitary neurofibroma arising from the thyroid capsule in a 64 year-old woman is reported. The tumor was adherent to the lower margin of the thyroid gland and extended into the anterior mediastinum. The unusual nature of the lesion, both its relationship to the thyroid gland and to the occurrence of a neural tumor in the anterior mediastinum is discussed.

Journal Article↗