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K F Tabbara

Publications and source records attributed to K F Tabbara.

At least 55 records · Page 3Linked to original sources
PubMed1997

Identification of a novel HLA-B allele (B*4202) in a Saudi Arabian family with Behçet's disease.

A new HLA-B antigen, tentatively called HLA-B42AND, was identified as a B42 serologic variant in a Saudi Arabian family. DNA sequencing analysis of the second and third exon of this new B allele revealed that B42AND was identical to B*4201 except for a single T to C substitution at position 97 of exon 2. This substitution results in histidine (CAC) at codon 9 in B42AND instead of tyrosine (TAC) in B*4201. The antigen frequency of B42AND in a Saudi Arabian population was around 10%. This novel B42AND has officially been named HLA-B*4202.

Alleles↗
PubMed1997

Adhesion molecules in vernal keratoconjunctivitis.

AIMS/BACKGROUND: Adhesion molecules play a key role in the selective recruitment of different leucocyte population to inflammatory sites. The purpose of the present study was to investigate the presence and distribution of adhesion molecules in the conjunctiva of patients with vernal keratoconjunctivitis (VKC). METHODS: The presence and distribution of adhesion molecules were studied in 14 conjunctival biopsy specimens from seven patients with active VKC and in four normal conjunctival biopsy specimens. We used a panel of specific monoclonal antibodies (mAbs) directed against intercellular adhesion molecule-1 (ICAM-1), intercellular adhesion molecule-3 (ICAM-3), lymphocyte function associated antigen-1 (LFA-1), very late activation antigen-4 (VLA-4), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leucocyte adhesion molecule-1 (ELAM-1) In addition, a panel of mAbs were used to characterise the composition of the inflammatory infiltrate. RESULTS: In the normal conjunctiva, ICAM-1 was expressed on the vascular endothelium only, LFA-1 and ICAM-3 on epithelial and stromal mononuclear cells, and VLA-4 on stromal mononuclear cells. The expression of VCAM-1 and ELAM-1 was absent. The number of cells expressing adhesion molecules was found to be markedly increased in all VKC specimens. This was concurrent with a heavy inflammatory infiltrate. Strong ICAM-1 expression was induced on the basal epithelial cells, and vascular endothelial cells. Furthermore, ICAM-I was expressed on stromal mononuclear cells. LFA-1 and ICAM-3 were expressed on the majority of epithelial and stromal infiltrating mononuclear cells. VLA-4 expression was noted on stromal mononuclear cells. Compared with controls, VKC specimens showed significantly more ICAM-3+, LFA-3+, LFA-1+, and VLA-4+ cells. VCAM-1 and ELAM-1 were induced on the vascular endothelial cells. CONCLUSIONS: Increased expression of adhesion molecules may play an important role in the pathogenesis of VKC.

Adolescent↗
PubMed1997

Cataract extraction in Behçet's disease.

AIMS/BACKGROUND: To assess the outcome and complications of cataract extraction in patients with Behçet's disease. METHODS: Thirty-six Behçet's disease patients underwent cataract surgery without intraocular lens implantation. Twenty-six patients had phacoemulsification or extracapsular cataract extraction, and ten patients had pars plana lensectomy/vitrectomy. The follow-up period ranged from 24 to 84 months (mean, 38 months). RESULTS: There was no statistically significant difference in the follow-up period of patients who underwent phacoemulsification, extracapsular cataract extraction, or pars plana lensectomy/vitrectomy. Sixteen (62%) of 26 patients who had extracapsular cataract extraction or phacoemulsification had a visual acuity of 20/200 or better compared with none of the 10 patients who had pars plana lensectomy/vitrectomy. Three (30%) of ten eyes which underwent pars plana lensectomy/vitrectomy eventuated in phthisis bulbi while none of the eyes that underwent extracapsular cataract extraction or phacoemulsification developed phthisis bulbi. CONCLUSION: Extracapsular cataract extraction or phacoemulsification had a better visual outcome and fewer postoperative complications than pars plana lensectomy/vitrectomy in patients with Behçet's disease.

Adult↗
PubMed1997

Trachoma in Saudi Arabia.

AIMS & BACKGROUND: The main objectives of this study were to determine the prevalence and magnitude of trachoma in Saudi Arabia and to evaluate the factors that play a role in the transmission and severity of the disease. METHODS: The samples consisted of a stratified multistage random cluster design that selected defined primary sampling units of 50-60 housing units in both metropolitan and non-metropolitan communities. RESULTS: In 1984, evidence of trachoma (active and inactive) was found among 22.2% of the Saudi population and 6.2% of the Saudis had evidence of active trachoma. In addition, 17.4% had conjunctival scarring as a result of old trachoma, and 1.5% had entropion or trichiasis. In 1994, clinical evidence of trachoma (active and inactive) was found among 10.7% of the Saudi population while 2.6% had active trachoma. Conjunctival scarring as a result of healed trachoma was seen in 8.1% and 0.2% had entropion and trichiasis. The prevalence of trachoma in households was directly related to the presence and appearance rating of children in a household, the presence of flies, and the appearance rating of the household itself. An increase in individual risk was found among women who veil and men who use kohl. CONCLUSION: This study has shown a remarkable decrease in the prevalence of active trachoma in Saudi Arabia over the past decade. The findings should serve as a basis for future plans for prevention and intervention.

Adolescent↗
PubMed1997

The differential diagnosis of posterior uveitis.

The diagnosis of posterior uveitis can be established in most cases on the basis of (1) morphology of the lesion, (2) the mode of onset and course of the disease, and (3) the association with other systemic diseases. The differential diagnosis of posterior uveitis include the following entities: (1) the viral infections, (2) the bacterial infections, (3) the parasitic infections, (4) the fungal infections, (5) the autoimmune diseases, and (6) the diseases of unknown origin.

Autoimmune Diseases↗
PubMed1996

Bilateral central retinal vein thrombosis in Behçet's disease.

Behçet's disease is a multisystem disorder affecting the skin, mucous membranes, eye, joints, central nervous system, and blood vessels. One of the known vascular complications of Behçet's disease is venous thrombosis or aneurysm formation. We report, herewith, a patient with Behçet's disease who developed radial artery aneurysm, deep venous thrombosis, and bilateral central retinal vein thrombosis. To our knowledge, this is the first report of bilateral central retinal vein thrombosis in association with Behçet's disease.

Adult↗
PubMed1996

An immunohistochemical study of topical cyclosporine in vernal keratoconjunctivitis.

PURPOSE: To determine the immunomodulating effects of topical cyclosporine on the immune cells in the conjunctival biopsy specimens obtained from patients with active vernal keratoconjunctivitis. METHODS: We studied six patients who had severe active vernal keratoconjunctivitis. Each patient was given topical cyclosporine 2% eyedrops four times daily. A 2 x 2-mm limbal conjunctival biopsy specimen was obtained from each patient before and three weeks after treatment. Using a panel of monoclonal and polyclonal antibodies and immunohistochemical techniques, we analyzed the conjunctival immune cells before and after cyclosporine treatment. RESULTS: Three weeks after topical cyclosporine treatment, there was marked clinical improvement and a statistically significant reduction in the number of epithelial and stromal class II MHC+ cells, UCHL1+ T cells, and stromal IgA+ and IgG+ plasma cells. The mean number of cells before and after therapy, respectively, were: class II MHC+ (epithelium), 31.5 +/- 13.1 and 8.3 +/- 5.6 (P = .031); class II MHC+ (stroma), 77.0 +/- 28.7 and 24.7 +/- 17.5 (P = .031); UCHL1+ T cells (epithelium), 24.5 +/- 14.1 and 4.2 +/- 2.9 (P = .031); UCHL1+ T cells (stroma), 78.7 +/- 31.1 and 44.5 +/- 27.5 (P = .031); IgA+ plasma cells, 66.7 +/- 32.1 and 22.2 +/- 7.8 (P = .031); and IgG+ plasma cells, 37.3 +/- 30.0 and 9.0 +/- 6.4 (P = .031). There was a statistically insignificant decrease in the epithelial class II MHC+ dendritic Langerhans cells, epithelial and stromal KP1+ macrophages, stromal OPD4+ helper/inducer T cells, and stromal L26+ B cells. The numbers of IgE+ plasma cells and mast cells were unaltered. CONCLUSION: The clinical improvement in vernal keratoconjunctivitis after topical cyclosporine therapy may result from its immunomodulating effect on the components of cell-mediated and humoral immune responses. In contrast, the drug has no immunomodulatory effect on mast cells and IgE-mediated allergic response.

Administration, Topical↗
PubMed1996

Single-dose azithromycin in the treatment of trachoma. A randomized, controlled study.

PURPOSE: To compare the safety and efficacy of single oral-dose azithromycin with a 7-week topical tetracycline ointment course in the treatment of active trachoma. METHODS: A total of 64 patients with active trachoma were selected randomly to receive azithromycin (20 mg/kg) in a single dose or topical tetracycline eye ointment for 6 weeks. Clinical assessments were made before and at 4, 8, 12, and 24 weeks after treatment. Conjunctival scrapings were obtained before and after 24 weeks after treatment and fixed for Giemsa and direct immunofluorescence staining. RESULTS: Trachoma resolved in 17 (63.3%) patients who received azithromycin compared with 19 (65.4%) who were treated with tetracycline ointment. There were no significant differences in treatment effect or baseline characteristics between the treatment groups. Both treatments were well tolerated, and no adverse events were noted. CONCLUSION: Single-dose azithromycin is as effective as a 6-week course of topical tetracycline ointment in the treatment of active trachoma. The findings may help establish high compliance in treating trachoma and could contribute to the control of trachoma worldwide.

Administration, Oral↗
PubMed1996

Immunopathogenesis of vernal keratoconjunctivitis.

We have analyzed the in situ distribution of immune cells in the conjunctival biopsy specimens obtained from patients with active vernal keratoconjunctivitis (VKC). We used immunohistochemical techniques and a panel of monoclonal and polyclonal antibodies. Our data point to a complex immunopathogenesis of the disease. Distinct components involved in IgE-mediated immune mechanisms, as well as humoral and cell mediated immune mechanisms were detected in the conjunctival tissues. In addition, we investigated the presence and distribution of adhesion molecules. In the normal conjunctiva, intercellular adhesion molecule-1 (ICAM-1) was expressed only on the vascular endothelium, lymphocyte function associated antigen-1 (LFA-1) and intercellular adhesion molecule-3 (ICAM-3) on epithelial and stromal mononuclear cells, and very late activation antigen-4 (VLA-4) on a few stromal mononuclear cells. Endothelial leukocyte adhesion molecule-1 (ELAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression was not detected. In VKC a marked increase of all these antigens was observed. Strong ICAM-1 expression was induced on the basal epithelial cells, and vascular endothelium. Furthermore, about 30% of the stromal mononuclear cells expressed ICAM-1. LFA-1 and ICAM-3 were expressed on the majority of infiltrating mononuclear cells. VLA-4 expression was noted on about 25% of the stromal mononuclear cells. ELAM-1 and VCAM-1 were induced on the vascular endothelial cells. Our results suggests that increased expression of adhesion molecules in VKC promotes the recruitment of inflammatory cells through blood vessels and the cell interaction between lymphocytes and antigen presenting cells, among lymphocytes, as well as between lymphocytes and epithelial cells.

Antigens, CD↗
PubMed1995

Eyelid laceration sustained in an attack by a rabid desert fox.

PURPOSE/METHODS: Two patients were bitten on the face by a rabid desert fox and sustained eyelid lacerations. The patients were examined and they received the same prophylactic treatment: human rabies immunoglobulin, intramuscularly and at the laceration site, and rabies human-diploid cell vaccine. RESULTS/CONCLUSIONS: One patient survived; the other died. Eyelid laceration sustained by a bite of a rabid animal is a life-threatening condition; patients should receive prompt rabies prophylaxis.

Animals↗