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Biomedical subjects

Antonio G Secchi

Publications and source records attributed to Antonio G Secchi.

8 recordsLinked to original sources
PubMed2006

Th1- and Th2-type cytokines in chronic ocular allergy.

BACKGROUND: Previous reports have suggested that Th2-type cytokines are important in the pathogenesis of ocular allergic diseases. The purpose of this study is to measure levels and mRNA expression of Th1- and Th2-type cytokines in patients with active vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC). METHODS: Tear samples and tear-isolated cells were obtained from 9 healthy participants (CT--controls), 28 VKC, and 6 AKC patients. IL-4, IL-13, and interferon gamma (IFNgamma) tear levels were determined by ELISA, and IL-4 and IFNgamma tear cell mRNA expression by RT-PCR. Effects of these cytokines on IL-6 and IL-8 secretion, and on ICAM-1 expression by conjunctival fibroblasts, were evaluated by ELISA and flow cytometry respectively. RESULTS: Interleukin-4 tear levels were increased in VKC and AKC compared with CT, but only IFNgamma significantly correlated with corneal involvement. An IL-4/13-dominant profile was found in 50% of VKC and in 17% of AKC patients, while a IFNgamma-dominant profile was found in 18% of VKC and in 17% of AKC patients. IL-4 and IFNgamma transcripts were detected in tear cells from 11 out of 12 VKC patients. IFNgamma upregulated expression of ICAM-1 on conjunctival fibroblasts and the secretion of IL-6 and IL-8. CONCLUSIONS: Although both IL-4 and IFNgamma are detected in tears, only IFNgamma levels correlated with disease severity and upregulated ICAM-1 on conjunctival fibroblasts, suggesting the role of IFNgamma in the inflammatory phase of chronic allergic eye diseases.

Adolescent↗
PubMed2006

Combined 50- and 20-MHz frequency ultrasound imaging in intermediate uveitis.

PURPOSE: To evaluate the information provided by multifrequency ultrasound examination in patients with intermediate uveitis. DESIGN: Prospective observational case series. METHOD: High-resolution ultrasonography with 50- and 20-MHz frequency immersion probes was performed in seven eyes of five young patients with clinical diagnosis of intermediate uveitis. RESULTS: Exudative material over the inferior pars plana and peripheral retina (snowbank) was found in all eyes with 50- and 20-MHz probe, although resolution of the latter was poorer. The 50-MHz imaging was superior for visualization of angle structures and details of pars planitis; the anterior vitreous involvement and cyclitic bands were better shown with the 20-MHz probe, which could also evidence cystoid macular edema. CONCLUSIONS: Ultrasound examination with both 50- and 20-MHz frequency probes can detect the typical snowbank in intermediate uveitis and be useful in eyes with small pupil, dense vitreitis, or both, especially before pars plana vitrectomy or cataract surgery.

Adolescent↗
PubMed2006

Case series of 406 vernal keratoconjunctivitis patients: a demographic and epidemiological study.

PURPOSE: To evaluate the specific allergic sensitization and epidemiological characteristics of vernal keratoconjunctivitis (VKC). METHODS: This retrospective non-comparative case series included 406 VKC patients. Data included patient and family histories, and results of allergic tests. Annual incidence and prevalence rates were calculated for a cohort of 128 VKC patients from the greater Padua area. RESULTS: The great majority of VKC patients were male (76%), with a male : female ratio of 3.3 : 1. A skin prick test, specific serum IgE or conjunctival challenge was positive in 43%, 56% and 58% of patients, respectively. In the cohort of patients from the Padua area, the prevalence of the disease was 7.8/100,000, with a higher rate in young males (57/100,000) compared with young females (22/100,000), and lower rates in people over 16 years of age (3.8/100,000 in males, 1/100,000 in females). The incidence of VKC was 1/100,000, with a higher rate in males under 16 years of age (10/100,000) compared with females (4.2/100,000). In people over 16 years of age, the incidence of the disease was 0.06/100,000, with no difference between males and females. CONCLUSION: An IgE-mediated sensitization was found in only half of the VKC patients. Vernal keratoconjunctivitis is not a rare event in the paediatric population but is an extremely rare new disease in adults.

Adolescent↗
PubMed2005

Urokinase plasminogen activator, uPa receptor, and its inhibitor in vernal keratoconjunctivitis.

PURPOSE: Plasminogen activators play a role, not only in fibrinolysis but also in events such as chemotaxis, collagen degradation, and cell spreading. The serine protease urokinase (uPA) is a potent chemoattractant for leukocytes that may be involved in the pathogenesis of severe forms of allergic conjunctivitis such as vernal keratoconjunctivitis (VKC). METHODS: Tear and peripheral blood samples were obtained from 20 patients with active VKC and from 19 normal subjects who formed the control group. Levels of plasminogen activity, uPA, tissue plasminogen activator (tPA), and their inhibitor, plasminogen activator inhibitor type-1 (PAI-1) were measured in tears and plasma of patients with VKC. The presence of tPA, uPA, and urokinase receptor (uPAR) in conjunctival tissues were evaluated by immunohistochemistry. uPA, uPAR, and PAI-1 expression and production were measured in conjunctival epithelial cell and fibroblast cultures treated with cytokines. RESULTS: Tear levels of uPA and tPA and tear plasminogen activity levels were significantly greater in patients with VKC than in control subjects. Increased staining for uPA and uPAR was found in VKC tissues compared with normal conjunctiva. Both conjunctival epithelial cells and fibroblasts demonstrated an increased expression of uPAR after exposure to IL-4 or -13, whereas uPA was highly expressed by epithelial cells exposed to IL-4. PAI-1 levels in culture medium were increased in IL-4-exposed epithelial cells compared to nonstimulated cells and were decreased in fibroblast culture. CONCLUSIONS: Increased expression of fibrinolytic system components and imbalance between plasminogen activators and PAI may be involved in the pathogenesis of severe allergic conjunctivitis, thus contributing to inflammatory cell migration and tissue remodeling.

Adolescent↗
PubMed2003

Effects of Th2 cytokines on expression of collagen, MMP-1, and TIMP-1 in conjunctival fibroblasts.

PURPOSE: To determine whether cytokines involved in chronic allergic conjunctival disorders may affect formation of giant papillae and tissue remodeling. METHODS: Conjunctival fibroblast cultures were challenged with different concentrations of human recombinant interleukin (IL)-4, IL-13, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha. Procollagens I (PIP) and III (PIIIP), matrix metalloproteinase (MMP)-1 and -9, and tissue inhibitor of metalloproteinase (TIMP)-1 were measured in supernatants, and their respective mRNAs were evaluated by RT-PCR. RESULTS: IL-4 and -13 (10 ng/mL) significantly increased production and expression of PIP compared with nonstimulated cells, whereas IFN-gamma elicited the opposite effect, at both the protein and mRNA levels. Both IL-4 and -13 significantly decreased production of MMP-1 and increased that of TIMP-1, whereas TNF-alpha increased production of MMP-1 and -9. Expression of MMP-1 was reduced by IL-4 and increased by the other tested cytokines, whereas expression of TIMP-1 was increased by all tested cytokines. CONCLUSIONS: IL-4 and -13 increased production of collagen and modified the equilibrium between MMP-1 and its inhibitor, TIMP-1. These effects were partially opposed by IFN-gamma and TNF-alpha.

Cell Division↗
PubMed2003

Tear levels and activity of matrix metalloproteinase (MMP)-1 and MMP-9 in vernal keratoconjunctivitis.

PURPOSE: To study levels and activity of matrix metalloproteinase (MMP)-1 and -9 and their tissue inhibitor (TIMP-1) in tears of patients with vernal keratoconjunctivitis (VKC), with and without severe corneal damage. METHODS: Tear samples were obtained from 16 patients with active VKC and 10 normal control subjects, after clinical evaluation and tear cytology. Tear levels of pro-MMP-1, pro-MMP-9, and TIMP-1 were measured by enzyme-linked immunosorbent assay (ELISA). Collagenase and gelatinase activity were measured in tears by MMP activity assays. Immunohistochemistry was performed on a fragment of superficial keratectomy from two vernal corneal ulcers. RESULTS: Tear levels of pro-MMP-1 and pro-MMP-9 were significantly increased in patients with VKC compared with control subjects (P < 0.001). MMP-1/TIMP-1 and MMP-9/TIMP-1 molar ratios were significantly increased (P < 0.001) in VKC. MMP-1 and MMP-9 activities were significantly increased in VKC tears compared with control samples (P < 0.005). MMP-9 activity correlated significantly with corneal involvement and giant papillae formation. Immunohistochemistry showed positive staining for MMP-9, fibronectin, and eosinophil cationic protein (ECP) on the superficial corneal stroma of the ulcer bed, but no inflammatory cells. CONCLUSIONS: Increased levels and activity of MMP-1 and -9 and an imbalance between MMPs and TIMP may be involved in the pathogenesis of VKC.

Adolescent↗
PubMed2002

Efficacy and safety of desonide phosphate for the treatment of allergic conjunctivitis.

PURPOSE: To study the safety and efficacy of the topical corticosteroid, desonide 0.25% ophthalmic solution, for inhibition of the clinical allergic reaction induced by conjunctival provocation (CPT) and for the treatment of seasonal allergic conjunctivitis (SAC). METHODS: For the CPT study, 12 allergic but inactive patients were exposed in both eyes to increasing doses of a specific allergen until a positive bilateral, symmetrical early- and late-phase reaction was obtained. After 2 weeks the last positive dose was readministrated and their positive response confirmed. After an additional 2 weeks, CPT was performed 30 minutes after topical administration of desonide in one eye and placebo in the contralateral eye (Group A) or after topical desonide or placebo four times a day for 2 days (Group B). Clinical signs and symptoms were recorded after 15, 30, and 60 minutes, and after 6 hours. Regarding the seasonal study, 96 patients with active SAC were treated bilaterally with either desonide or fluorometholone for 3 weeks, and allergic signs and symptoms evaluated at regular intervals. The safety of the drugs was assessed by identification of any side effects or adverse events of any kind. RESULTS: For the CPT study: individual itching and redness, and the sum score for signs and symptoms were all statistically (p < 0.05) and clinically (greater than 1 change between treated eyes) significantly lower in desonide versus placebo eyes. Both early- and late-phase reactions were reduced by desonide pretreatment. Seasonal study: desonide and fluorometholone were both highly effective in reducing itching, tearing, and conjunctival hyperemia over time (p < 0.0001). Both drugs appeared safe, with no statistically significant changes in IOP observed with either treatment. CONCLUSIONS: Desonide has a significant therapeutic effect on both the induced conjunctival early- and late-allergic reaction and in active SAC. It was also safe, with no side effects such as increases in intraocular pressure observed by physician or patient.

Administration, Topical↗