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Biomedical subjects

A Bron

Publications and source records attributed to A Bron.

At least 73 records · Page 4Linked to original sources

Bilateral loss of vision and macular ischemia related to Behçet disease.

PURPOSE: To report a 61-year-old man with sudden onset of visual loss in both eyes related to bilateral macular ischemia. METHODS: The patient underwent comprehensive ophthalmic examination including slit-lamp and fundus examination, fluorescein angiography, and visual field testing as well as biologic screening. RESULTS: Bilateral macular ischemia associated with peripheral retinal vasculitis was confirmed by angiography. We diagnosed Behçet disease by association of ocular, oral, and cutaneous involvement according to the criteria of the international study group for Behçet disease. The patient was treated with corticosteroids. CONCLUSION: In Behçet disease, sudden onset of bilateral vision loss may be associated with bilateral retinal vascular disease and macular ischemia. Prompt diagnosis and treatment with systemic corticosteroids may be beneficial.

Behcet Syndrome↗

Effects of high dose intravenous immunoglobulin in two severe corticosteroid insensitive asthmatic patients.

Preliminary observations of the clinical efficacy of intravenous immunoglobulin in two patients with severe corticosteroid insensitive asthma are reported. In both patients treatment with intravenous immunoglobulin resulted in clinical improvement and enabled a significant reduction in the dose of prednisolone. In one of the patients fibreoptic bronchoscopy with endobronchial biopsies was performed and peripheral blood was analysed by flow cytometry before and after treatment. Immunohistological analysis of the biopsy samples after treatment showed a decrease in the number of all cell types, especially CD3+ T cells, CD4+ T cells, and activated CD25+ T lymphocytes, which was associated with a reduction in peripheral blood T cell activation. Intravenous immunoglobulin may be a valid option for the treatment of corticosteroid insensitive asthma. To elucidate the role and mode of action of intravenous immunoglobulin further studies in larger groups of patients are needed.

Adolescent↗

Free and complexed interleukin-8 in blood and bronchial mucosa in asthma.

We have tested the hypothesis that the expression of interleukin-8 (IL-8) is increased in bronchial tissue and circulating leukocytes of atopic asthmatics, indicating a role for this chemokine in asthma. The concentration of IL-8 in its free form and complexed with IgG or IgA was measured by ELISA in bronchial tissue, serum, and lysates of freshly isolated peripheral blood mononuclear cells and granulocytes from subjects with mild or severe asthma and nonatopic nonasthmatic subjects. Serum ECP was measured by fluorescent enzyme immunoassay. Free IL-8 was detected in the sera (n = 44) and bronchial tissue (n = 9) of all subjects with severe atopic asthma, but it was undetectable in normal subjects and subjects with mild atopic asthma, suggesting that free IL-8 is a marker of severe asthma. A positive correlation between free IL-8 and serum ECP levels found in severe disease suggests that IL-8 is associated with eosinophil activation. Complexes of IL-8 with IgA and IgG were detected in all serum and tissue samples. However, the levels of the IL-8-IgA complex were increased in the bronchial mucosa in asthma, and in blood were related to disease activity. Together, these results point to upregulation of IL-8 production in asthma and the induction of IL-8 binding immunoglobulins of the IgA class in the inflamed mucosa. We suggest a proinflammatory role for these complexes in lung tissue.

Asthma↗

New insights into the pathogenesis of severe corticosteroid-dependent asthma.

Severe asthma is characterized by persistent T-cell activation, as demonstrated in both peripheral blood and bronchial mucosa. Endobronchial biopsy specimens of patients with severe, corticosteroid-dependent asthma revealed increased expression of CD25+ on mucosal T cells. Increased immunoreactivity for IL-5 further supports the evidence that the inflammatory response is orchestrated by TH2-type T cells. Peripheral blood eosinophils and total serum IgE levels were increased in the absence of allergen and despite optimal treatment. The chemokine IL-8 may also be an aggravating factor in severe asthma; as well as being a potent chemotactic and activating factor for neutrophils, it may also be chemoattractant for eosinophils. We have recently detected increased levels of free IL-8 in the peripheral blood of patients with chronic severe asthma but not in healthy control subjects or in patients with mild asthma, even after allergen challenge. In patients with severe asthma there may be an imbalance between IL-8 production and the blocking capacity of IL-8 autoantibodies. Higher levels of IL-8 complexed to IgA autoantibody and increased numbers of activated T cells were also found in patients with unstable asthma compared with patients who had severe but stable disease. We conclude that IL-8 may provide an additional marker of asthma severity and corticosteroid responsiveness.

Adrenal Cortex Hormones↗

[Orbital lymphangioma: a clinical and radiological entity. Apropos of a case].

We reported on the case of a seven years-old boy suffering from an acute unilateral proptosis. Diagnosis of orbital lymphangioma was made with Magnetic Resonance Imaging (MRI) showing an intra-tumoral hemorrhage in a vascular tumor unrelated to general circulation. Authors underlined the interest of MRI due to its unique ability to characterize hemorrhage with hemodynamic isolation and to plan therapeutic approach. Even controversial, conservative management remained the best choice but surgery should be considered if vision is threatened.

Child↗

Expression of inflammatory membrane markers by conjunctival cells in chronically treated patients with glaucoma.

PURPOSE: Recent histologic studies of conjunctival tissues in patients who have had long-term treatment for glaucoma have shown in situ an abnormal infiltration by inflammatory cells. In this study, conjunctival inflammatory antigens were investigated in impression cytology specimens from patients who have been and those who have not been treated for glaucoma. METHODS: This study included 107 eyes from 55 patients with primary open-angle glaucoma. Of these, 48 had received prolonged topical treatments, all containing benzalkonium chloride as a preservative. Seven glaucomatous eyes could be examined before any treatment. In addition, the authors examined 11 patients (21 eyes) receiving anticataract eye drops preserved with chlorhexidine and 15 normal untreated subjects (30 eyes). In all patients, immunocytochemistry was performed in impression cytology specimens, using two monoclonal antibodies against HLA-DR antigens and receptor to IgE CD23. RESULTS: None of the untreated eyes showed reactivity for either monoclonal antibody. In contrast, HLA-DR expression by conjunctival cells was found in 43 of 88 treated eyes (mean percentage of reactive cells, 70% +/- 28%) and positive staining for receptor to IgE in 26 of 68 eyes (52% +/- 28% of conjunctival cells). Results were not related to a specific treatment or combination of anti-glaucoma drugs. However, the proportion of positive specimens (3/14 for both antigens) in the group receiving chlorhexidine-containing eye drops was significantly lower than that found in the patients with glaucoma. CONCLUSION: This study showed abnormal expression of inflammatory markers without clinical inflammation at the level of conjunctival cells in repetitive contact with various anti-glaucomatous treatments and their common preservative, benzalkonium chloride. Failure in filtering glaucoma surgery was found to be related to prolonged medical treatment; therefore, a topical sensitization to preservatives and/or anti-glaucoma drugs has been hypothesized. An immunocytologic test thus could be useful for qualitative and quantitative investigation of drug-induced conjunctival inflammation and predict high-risk patients.

Adrenergic beta-Antagonists↗

[Prophylactic antibiotic therapy in ocular surgery].

Prophylactic antibiotics have been used by ophthalmic surgeons routinely before and after surgery. However, the optimal type of antibiotics and route of administration have not yet been clearly established. In this article, ocular surgery patterns, bacteriology and pharmacokinetics of antibiotics within the eye are reviewed, to try to provide rationale for antimicrobial prophylaxis.

Anti-Bacterial Agents↗

Expression of mucin peptide and blood group ABH- and Lewis-related carbohydrate antigens in normal human conjunctiva.

PURPOSE: The immunohistochemical characterization of mucin peptide antigens and identification of blood group ABH- and Lewis-related carbohydrate antigens expressed in epithelium of normal human conjunctiva. METHODS: Immunoperoxidase characterization of conjunctival glycoproteins was performed using antibodies against peptide and saccharide moieties of gastrointestinal mucins on conjunctival biopsy specimens from 89 healthy individuals of known ABO and Lewis red cell phenotypes. RESULTS: Ocular mucins had epitopes in common with the peptidic core of gastric mucin (M1 epitopes), but also contained sialylated saccharide chains like those of intestinal mucins. Anti-M1 gastric mucins, anti-type 1 precursor, and anti-T antibodies strongly stained the cytoplasm of goblet cells. Anti-Lea, anti-NeuAc-Lea, and anti-Leb antibodies stained both epithelial and goblet cells of Lewis-positive individuals only. Anti-H type 1, anti-H type 2, anti-A, and anti-B stained epithelial cells of ABH secretors. In addition, A-like epitopes independent of secretor phenotype were found in epithelial and goblet cells of all donors. CONCLUSIONS: The conjunctival mucins cross-react with antibodies specific for digestive mucins and for blood group-related carbohydrate epitopes. The distributions of Lewis and secretor phenotypes in conjunctiva are: 19% Lewis-positive nonsecretors, 71% Lewis-positive secretors, and 10% Lewis-negative secretors. Lea and Leb antigens are present on epithelial cells of Lewis-positive nonsecretors and Lewis-positive secretors, respectively, as expected for antigens under control of Lewis and secretor genes. The secretor alpha-2-fucosyltransferase is not expressed on goblet cells, as described for the goblet cells of the distal rectal colonic mucosae. ABH antigens synthesized by the products of A1, A2, B, and Se genes and modulated by the presence of the product of the Lewis gene are found in epithelial cells. In addition, A-related epitopes independent of the A1-A2 subtype, secretor, and Lewis phenotypes also are present in both epithelial and goblet cells.

ABO Blood-Group System↗

[Mucocele: a cause of exophthalmos originating blindness].

Inflammatory exophthalmos with visual loss due to optic atrophy is reported in a 45-year-old man. Computed tomography showed an ethmoido-frontal mucocel. This single case stresses the severe complication of a mucocel like optic nerve head atrophy. The different tools for diagnosis and treatment are also emphasized.

Blindness↗

[Corneal pseudo-dystrophic complication caused by contact lenses].

The authors report the cases of two patients suffering of a rare long-term complication of contact lens wearing. Both patients wore daily soft contact lens for 5 and 8 years respectively. They presented with bilateral central predescemetic avascular haze associated with mild corneal stromal edema, descemetic folds in one patient and polymegethism on endothelial specular microscopic examination. The vision impairment was severe, unilateral in one patient and bilateral in the other. More than one year after removal of the contact lenses, only one patient fully recovered her initial visual acuity. The mechanisms of the onset of this corneal pseudo-dystrophy are discussed. Hypoxia and acidosis of the cornea induced by the contact lens are most probably responsible for this complication through endothelial metabolic dysfunction.

Adult↗

[Hertwig Magendie syndrome].

The "skew deviation" also called Hertwig Magendie syndrome is an ocular static disease. Two features are encountered: conjugate deviation and vertical divergence with one eye with upward gaze and the other with one downward gaze. The authors report a simple case in a 50 years old woman. The role of M.R.I. or C.T. scan in the diagnosis is emphasized. The pathogenic mechanism remains obscure.

Atrophy↗

[Principles of the treatment of ocular infections].

Ocular infections are still quite common and their clinical presentation is variable; some of them may lead to blindness. In this paper only severe infections like keratitis and endophthalmitis are considered. The rationale for treatment and prophylaxis is based upon bacteriological findings, understanding of ocular barriers and pharmacokinetics of antibacterial agents.

Drug Administration Schedule↗