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Biomedical subjects

J C Pastor

Publications and source records attributed to J C Pastor.

45 records · Page 3Linked to original sources
PubMed1990

Pharmacologic modulation of vascular permeability in ocular allergy in the rat.

Evans blue (EB) dye extravasation has been used as a reliable and objective parameter of the increased vascular permeability of an allergic conjunctivitis experimental rat model that closely mimics human ocular allergy. Five male Wistar rats, previously immunized (Group 1), had DL-dithiothreitol (DTT) applied topically to one eye 15 min prior to topical challenge with egg albumin (EA). The fellow eye (control) received phosphate buffered saline (PBS) 15 min prior to receiving EA. Immediately prior to challenge, the rats were injected intravenously with EB. After 30 min, the animals were killed and the dye extracted from the eyes. The intensity of EB extravasation was determined by spectrophotometry at 620 nm. EB extravasation was significantly higher in the eyes that received DTT than in those that received PBS. Groups 2, 3 and 4 of nonimmunized rats served as additional controls: Group 2 for DTT toxicity, Group 3 as a proof of the reaginic antibody mediation and Group 4 as a control of EB extravasation under normal conditions. Five additional groups of five rats each were immunized and both eyes of each rat received DTT 15 min before EA challenge. One eye of each rat received 0.1% dexamethasone sodium phosphate topically (Group 5), 0.1% pyrilamine maleate (Groups 6 and 7), and 2% disodium cromoglycate (DSCG) (Groups 8 and 9). The fellow eye received the solvent of each drug topically (control). In the eyes treated with antiallergic drugs, EB extravasation decreased 40% for dexamethasone, 44.1% and 10.4% for pyrilamine, and 51.4% and 51.2% for DSCG.

Animals↗
PubMed1985

[Leukemic infiltration in the anterior chamber of the eye].

Leukaemic infiltration of the anterior chamber of the eye (hypopyon and corneal opacity) was the only sign of relapse in two girls with acute lymphoblastic leukaemia who had been off treatment for one and three years. The malignant cells had probably been present in the eye since the onset of the disease. The anterior segment of the eye may be a pharmacologycal "sanctuary" in patients with ALL. The response to radiotherapy was good but this treatment should be coupled with systemic chemotherapy and CNS prophylaxis.

Anterior Chamber↗
PubMed1979

[Incidence of diabetic retinopathy].

The epidemiology of retinal microangiopathy in 410 diabetic patients is discussed. The correlations between age, duration of diabetes, treatment, artheriosclerotic disease, arterial hypertension and obesity was determined.

Adult↗
PubMedDate not supplied

Proliferative vitreoretinopathy: an overview.

Proliferative vitreoretinopathy (PVR) is still the most common cause of failure of surgery for rhegmatogenous retinal detachment, despite the substantial effort that has been devoted to better understanding and managing this condition during the past 25 years. Basic research has indicated that PVR represents scarring, the end stage of the wound-healing process that occurs after retinal detachment surgery. Medical treatment has been directed toward preventing inflammation, the first phase of the wound healing process, and inhibiting cell proliferation, the second phase. The 1983 Retina Society classification was modified in 1989 by the Silicone Study Group, whose classification differentiates between posterior and anterior forms of PVR and recognizes three patterns of proliferation: diffuse, focal, and subretinal. The anterior form has a worse prognosis than the posterior form, and its treatment requires more complex surgical procedures. In this review, risk factors and pathobiology of PVR are discussed, and management of PVR of various degrees of severity are considered.

Animals↗
PubMedDate not supplied

Combined pharmacologic therapy in a rabbit model of proliferative vitreoretinopathy (PVR).

PURPOSE: This study was designed to evaluate the efficacy of a combined treatment, previously used to prevent fibrosis after glaucoma surgery, to inhibit an experimental model of proliferative vitreoretinopathy (PVR). METHODS: Two groups of albino rabbits were used. In the control group (group 1, n = 14), experimental PVR was induced using vitrectomy, retinotomies, cryotherapy and intraocular injection of platelet-rich plasma. In the experimental group (group 2, n = 15), after PVR was induced, the following treatment was administered for 4 weeks: systemic methylprednisolone, sodium diclofenac and colchicine combined with topical atropine 1%, adrenaline 10% and dexamethasone phosphate 0.1%. Follow- up consisted of fundus examination for 4 weeks. Results were classified according to Fastenberg's classification. Only retinal detachments were considered to compare the two groups. Nonparametric test was used. RESULTS: Retinal detachments were observed in 85.7% of group 1 and 33.3% of group 2 at the end of the follow-up (p<0.01). No major systemic complications were observed. CONCLUSIONS: Combined therapy seems to be useful for treating experimental PVR.

Animals↗
PubMedDate not supplied

Antisilicone antibodies in patients with silicone implants for retinal detachment surgery.

A modified ELISA assay was used to detect IgG binding to silicone and IgG subtypes in serum of patients bearing silicone bands, silicone sponges and intraocular silicone oil. Presence of autoantibodies (rheumatoid factor, antinuclear antibody, and SCL 70) and signs and symptoms of autoimmune diseases were also checked. Antisilicone antibodies were detected in 35.7% of patients with solid silicone and in 83% in those with silicone oil. This increase in IgG is mainly due to IgG1. Nevertheless no positive results were found in detecting signs and symptoms of autoimmune diseases.

Adolescent↗
PubMedDate not supplied

Clinical consequences of the use of highly purified silicone oil. Comparative study of highly and less purified silicone oil.

PURPOSE: To compare the ocular toxicity caused by the use of highly purified silicone oil to less purified silicone oil in humans. METHODS: Fifty-six eyes received 2,000 centistokes (cs) purified silicone oil (group 1) and 42 eyes received 2,000 cs fractionated (highly purified) silicone oil (group 2) after pars plana vitrectormy. Follow-up ranged from 6 to 48 months. RESULTS: Six months after injection, the following complications were found in groups 1 and 2, respectively: ocular hypotension (< 13 mmHg), 39.3% and 31%, sustained ocular hypertension (> 23 mmHg), 19.6% and 19%; acute hypertensive peaks (> 30 mmHg), 23.2% and 11.9%; corneal alterations, 19.6% and 14.3%; emulsification, 1.8% and 2.4%; silicone oil cloudiness, 28.6% and 0%; preretinal reproliferation, 14.3% and 4.8% and total or partial retinal reattachment, 78.6% and 90.5%. CONCLUSIONS: Highly purified silicone oil was better tolerated than the less purified oil and caused fewer complications. Poorly purified silicone oils should be avoided in clinical practice.

Aged↗
PubMedDate not supplied

Experimental model of corneal haze in chickens.

PURPOSE: To develop an experimental animal model of corneal haze following photorefractive keratectomy (PRK). METHODS: Fifteen Iber Braun hens underwent unilateral PRK for -9.00 D of myopia. The animals were sacrificed at 1, 3, and 6 months postoperatively, and light microscopy was performed. RESULTS: Slit-lamp microscopy showed haze in the PRK-treated eyes. Histopathologic study disclosed epithelial hyperplasia, basement membrane abnormalities, and extensive anterior stromal disorganization. CONCLUSIONS: An easy and inexpensive model of haze after PRK was developed in an animal with Bowman's layer. This new model could be useful to understand the pathophysiology and pharmacologic modulation of corneal haze.

Animals↗