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Biomedical subjects

Y El-Shabrawi

Publications and source records attributed to Y El-Shabrawi.

15 recordsLinked to original sources
PubMed2006

Lamellar corneal dissection for visualization of the anterior chamber before triple procedure.

PURPOSE: Open-sky cataract extraction during triple procedure can be associated with higher risk of complications owing to the missing counterbalance by the cornea. Herein, we present a fast and easy technique for visualization of the anterior chamber and the lens in eyes with opaque corneas planed for triple procedure. MATERIALS AND METHODS: Four patients with corneal oedema due to Fuchs' endothelial dystrophy and cataract underwent triple procedure. As the anterior chamber view was limited, the central 7.0 mm of the cornea was marked. Then, 60-80% of the corneal thickness was removed by lamellar dissection and filled with hydroxypropylmethylcellulose. Continuous curvilinear capsulorhexis (CCC) and phacoemulsification with intraocular lens implantation through a corneoscleral tunnel were then performed and at the end the remaining corneal tissue was excised and the donor tissue fixed with a single running continuous suture. RESULTS: Lamellar corneal dissection enhances the anterior chamber view and CCC can be performed under stable anterior chamber condition. Phacoemulsification via sclerocorneal tunnel could be easily performed under good anterior chamber view in all cases. The operation time was 60-75 min in all cases. CONCLUSION: Lamellar corneal dissection in opaque corneas before cataract extraction is a useful technique for enhancing anterior chamber view in cases of triple procedure.

Anterior Chamber↗
PubMed2006

Adverse skin reactions to infliximab in the treatment of intraocular inflammation.

TNFalpha inhibitors are more widely used in the treatment of intraocular inflammation, thus ophthalmologists should become aware of possible adverse events, associated with this form of treatment. Herein we report two cases of cutaneous adverse events in uveitis patients treated with infliximab. In one patient, the primary outbreak of pustular psoriasis was observed after her third infusion. A second patient developed impetigo contagiosa induced by Staphylococcus aureus. Thus patients undergoing treatment with infliximab should be monitored carefully since dermal infections and pustular psoriasis, which may be triggered by streptococcal infection, may occur under this regime.

Adolescent↗
PubMed2005

TNF-alpha promoter polymorphisms and primary open-angle glaucoma.

PURPOSE: Primary open-angle glaucoma (POAG) is a multifactorial optic neuropathy with a strong hereditary component. Recent studies suggested a role for tumour necrosis factor-alpha(TNF-alpha) in the pathogenesis of POAG. The purpose of the present study was to investigate a hypothesized association between the TNF-alpha-308G>A and -238G>A gene polymorphisms and the presence of POAG in a Caucasian population. METHODS: The present case-control study comprised 114 unrelated patients with POAG and 228 healthy control subjects, matched for age and gender. Genotyping of the TNF-alpha-308G>A and -238G>A polymorphisms was performed using polymerase chain reaction. RESULTS: Allelic frequencies and genotype distributions of both the TNF-alpha-308G>A and -238G>A gene polymorphisms did not significantly differ between patients with POAG and control subjects. Presence of the TNF-alpha-308A-allele was associated with an odds ratio (OR) of 0.96 for POAG, whereas an OR of 0.52 was found among carriers of the TNF-alpha-238A-allele. CONCLUSION: Our data suggest that none of the investigated TNF-alphagene polymorphisms is a major risk factor among Caucasian patients with POAG.

Aged↗
PubMed2005

[ABO blood group expression in corneal allograft failures].

BACKGROUND: ABO blood group antigens are only expressed by the epithelial cells of normal human corneas. Since AB0 blood group antigens are also known to be expressed on stromal and endothelial cells of inflamed corneas, this study aimed to investigate the extend of ABO blood group antigen expression in corneal allograft failures. MATERIAL AND METHODS: Twenty-two failed corneal allografts of 22 patients were examined. In 12 cases the patients had clinically proven corneal allograft rejection. In 10 cases there was no evident history of allograft rejection and the diagnosis graft failure due to chronic endothelial cell loss was made. Immunohistochemical staining of paraffin embedded sections was performed with monoclonal mouse antibodies to human blood group antigen A or B using the streptavidin-biotin-peroxidase complex technique. RESULTS: Blood group antigens A or B were expressed by stromal keratocytes in 5 out of 12 and by endothelial cells in 7 out of 12 corneas with clinically proven immunologic graft rejection. Corneal transplants with chronic endothelial cell loss expressed blood group antigens A and/or B on the endothelial cells in three out of ten cases. CONCLUSION: The results of this study show that ABO blood group antigens can be up-regulated in cases of corneal allograft failure, especially in cases of immune mediated graft rejection. This phenomenon might play a role in corneal allograft rejection.

ABO Blood-Group System↗
PubMed2001

MMP-9 is predominantly expressed in epithelioid and not spindle cell uveal melanoma.

Extracellular matrix-degrading enzymes are crucial for cancer metastases. One group of enzymes that has been increasingly implicated in the breakdown of the extracellular matrix, and hence the intravasation and dissemination of tumour cells, is the family of metalloproteinases. In the recent past, increasing efforts have led to the development of more or less specific matrix metalloproteinase (MMP) inhibitors. Data concerning the molecular nature and timing of the contribution of MMPs to tumour spread is of paramount importance in clarifying which MMP is an appropriate target for more selective MMP inhibition in future tumour therapy. This study immunohistochemically characterized the expression pattern of MMP-2, -3, and -9 in 26 uveal melanomas. Forty-six per cent of the uveal melanomas expressed MMP-2 and/or MMP-9. MMP-3 expression was seen in 17 out of 26 uveal melanomas. MMP-9, previously shown to play an important part in tumour dissemination, was predominantly present in epithelioid melanomas (71.4%) or the epithelioid portion of mixed cell uveal melanomas (67%), whereas only one out of ten spindle cell melanomas showed MMP-9 expression (10%). MMP-2 and MMP-9 expression was associated with a significantly higher incidence of metastatic disease. The survival rate of patients with MMP-2-positive melanomas was 31% vs. 85% for patients with MMP-2-negative (p<0.05); for MMP-9-positive uveal melanomas the survival rate was 27% vs. 85% with MMP-9-negative uveal melanomas (p<0.04). The fact that patients suffering from TIMP-1- as well as TIMP-2-positive uveal melanomas tended to show a better survival rate (72% vs. 45% for TIMP-1; 88% vs. 37% for TIMP-2) supports the view that proteolytic enzymes are of importance in tumour spread.

Aged↗
PubMed2001

[Optic nerve involvement in syphilis in 4 patients].

BACKGROUND: Due to increasing numbers of cases syphilis again becomes more important in ophthalmology. Syphilitic ocular manifestations do not show any typical characteristics and therefore are often not diagnosed although a correct and early diagnosis with adequate therapy is very important for the visual outcome. PATIENTS: We report on four patients with luetic ocular fundus manifestations, who were referred to our clinic with unspecific ocular complaints. Funduscopic examination revealed in all patients a papilledema, which was bilateral in three patients and unilateral in one patient. Additional findings were a non-granulomatous uveitis anterior and a chorioretinitis in both eyes of a 61-year-old HIV positive patient with retinal scars from a bilateral acute retinal necrosis syndrome (ARN), a mild non granulomatous iridocyclitis in a 53-year-old patient and a bilateral chorioretinitis and a cystoid macular edema in a 37-year-old patient. A 54-year-old patient showed a vein branch occlusion. Serological analysis demonstrated active syphilis in all cases and an EBV-infection in two patients. After penicillin therapy the ocular findings resolved. CONCLUSION: In all cases of inflammatory fundus manifestations syphilis should be taken into consideration and serological lues tests should be performed routinely.

Adult↗
PubMed2000

cDNA cloning and analysis of tissue-specific expression of mouse peroxisomal straight-chain acyl-CoA oxidase.

Straight-chain acyl-CoA oxidase is the first and rate limiting enzyme in the peroxisomal beta-oxidation pathway catalysing the desaturation of acyl-CoAs to 2-trans-enoyl-CoAs, thereby producing H2O2. To study peroxisomal beta-oxidation we cloned and characterized the cDNA of mouse peroxisomal acyl-CoA oxidase. It consists of 3778 bp, including a 1983-bp ORF encoding a polypeptide of 661 amino-acid residues. Like the rat and human homologue the C-terminus contains an SKL motif, an import signal present in several peroxisomal matrix proteins. Sequence analysis revealed high amino-acid homology with rat (96%) and human (87%) acyl-CoA oxidase in addition to minor homology ( approximately 40%) with other related proteins, such as rabbit trihydroxy-cholestanoyl-CoA oxidase, human branched chain acyl-CoA oxidase and rat trihydroxycoprostanoyl-CoA oxidase. Acyl-CoA oxidase mRNA and protein expression were most abundant in liver followed by kidney, brain and adipose tissue. During mouse brain development acyl-CoA oxidase mRNA expression was highest during the suckling period indicating that peroxisomal beta-oxidation is most critical during this developmental stage. Comparing tissue mRNA levels of peroxisome proliferator-activated receptor alpha and acyl-CoA oxidase, we noticed a constant relationship in all tissues investigated, except heart and adipose tissue in which much more, and respectively, much less, peroxisome proliferator-activated receptor alpha mRNA in proportion to acyl-CoA oxidase mRNA was found. Our data show that acyl-CoA oxidase is an evolutionary highly conserved enzyme with a distinct pattern of expression and indicate an important role in lipid metabolism.

Acyl-CoA Oxidase↗
PubMed1999

The role of UV-radiation in the development of conjunctival malignant melanoma.

PURPOSE: To investigate the possible role of UV-radiation in the development of conjunctival malignant melanoma. N-ras mutations are frequently found in cutaneous melanomas of sun-exposed body areas. UV-radiation is thought to induce mutations in the N-ras gene, that convert these genes into active oncogenes. The presence of N-ras mutations has been considered an indicator for UV-exposure in the development of melanomas on sun-exposed body sides. METHODS: We analyzed six paraffin-embedded conjunctival melanomas for mutations of the N-ras gene. Codons 12, 13 and 61 were amplified using polymerase chain reaction and sequenced. RESULTS: We could not detect point mutations of the N-ras gene in our samples. CONCLUSION: Since we could not find deviations from the wild type sequence in the N-ras gene, our study does not support UV-exposure as being causative in the development of conjunctival melanoma.

Codon↗
PubMed1998

Recurrent nodular scleritis associated with varicella zoster virus.

PURPOSE: To describe a case of recurrent nodular scleritis that was apparently caused by reactivation of a varicella zoster virus infection. METHODS: Case report. Immunohistochemistry and polymerase chain reaction were used to detect viral antigen and DNA in the biopsy specimen of inflamed sclera of a patient with a history of recurrent nodular scleritis.

2-Aminopurine↗
PubMed1998

mRNA levels of alpha1(VI) collagen, alpha1(XII) collagen, and beta ig in rabbit cornea during normal development and healing.

PURPOSE: Type VI and XII collagens and beta ig, major components of the interfibrillar matrix, may maintain proper spacing among collagen fibrils, necessary for corneal transparency. During normal corneal stroma development and healing, changes in mRNA levels of these proteins were measured to determine whether differences in steady state levels are indicative of the unique structure produced by each corneal tissue. METHODS: A full-thickness excision wound was made in each cornea of six adult rabbits and allowed to heal for 1, 2, or 4 weeks. Scar tissue from two rabbits (four scars) were used from each time period and processed for RNA extraction. Total RNA from 23-day-old fetal rabbit corneas (equivalent to approximately 1 week of stromal development) and 8-day-old neonate corneas (equivalent to approximately 3.5 weeks of stromal development) was also extracted. Relative quantities of alpha1(VI) collagen, alpha1(XII) collagen, beta ig, and beta-actin mRNAs were determined by competitive reverse transcriptase-polymerase chain reaction. Glyceraldehyde-3-phosphate dehydrogenase was used as a housekeeping gene. RESULTS: Increased mRNA levels for alpha1(VI) and alpha1(XII) collagens, beta ig, and beta-actin were seen during the first 2 weeks of healing and were followed by a decrease in 4-week-old scars. Similar increases were seen in fetal corneas with a further increase in the neonate. Differences in the beta ig mRNA levels relative to that of alpha1(XII) collagen in fetal stroma and in comparison with 1-week-old wounds suggest a higher production of beta ig in early healing tissue. CONCLUSIONS: Alterations of mRNA levels during healing and development are consistent with the cellular events and deposition of extracellular matrices in these corneal tissues. Assuming that extracellular matrix protein production is regulated at the transcriptional level, relative changes in beta ig and collagen mRNA levels reflect differences in protein deposition in early fetal and healing tissues. This is consistent with differences in the organization of the interfibrillar matrices of these tissues and their transparency.

Actins↗