[Deep anterior lamellar keratoplasty in the surgical treatment of keratoconus. A 1-year follow-up]. / Kératoplastie lamellaire antérieure profonde dans le traitement chirurgical du kératocône. Recul de plus d'un an.

OBJECTIVE: To evaluate the results of deep anterior lamellar keratoplasty (DALK) using dissection with air or with a viscoelastic substance in the surgical treatment of keratoconus as an alternative to penetrating keratoplasty. MATERIAL AND METHODS: This prospective monocentric noncomparative study involved patients with contact lens-intolerant keratoconus operated on between February 2001 and September 2002. Deep lamellar dissection was performed either by air injection into the cornea to create a white emphysema of the stroma or by viscoelastic injection. This allows the surgeon to separate Descemet's membrane from the posterior stroma using the air-to-endothelium interface. Previously, aqueous humor was replaced by air in the anterior chamber to visualize the posterior corneal surface. A full-thickness allogenic corneal button was sutured into the recipient bed, after stripping its Descemet's membrane. RESULTS: Fifteen eyes of 15 patients (mean age, 41.2 years) underwent DALK. The mean preoperative visual acuity was 0.11+/-0.06. At 1 year, the mean best corrected visual acuity was 0.47+/-0.16 (p<0.001). Mean keratometric astigmatism was reduced from 6.97+/-3.3 D to 2.77+/-1.76 D at 1 year (p<0.001). Specular microscopy 3 months postoperatively revealed average endothelial cell counts of 2018+/-662/mm2, while 1 month preoperatively this value was 2604+/-235/mm2 (cell loss, 22.5%; p>0.05). Perforation of Descemet's membrane during surgery occurred in five eyes (33.3%). Two cases were converted to penetrating keratoplasty. There was no endothelial rejection. CONCLUSION: In this series, DALK appears to be a promising procedure for treatment of keratoconus with encouraging refractive outcome, no progressive primary graft failure, and no allogenic endothelial graft rejection. DALK is an interesting alternative for penetrating keratoplasty even if it is technically more difficult.

[Corneal transplantation of a corneal graft with radial keratotomy]. / Greffe de cornée avec un greffon cornéen aux antécédents de kératotomie radiaire.

INTRODUCTION: We report the case of a patient operated on for penetrating keratoplasty with a corneal graft with radial keratotomy. CASE REPORT: A 27-year-old man underwent penetrating keratoplasty for keratoconus. Graft incisions of radial keratotomy were discovered the day after surgery. Corneal graft examination and endothelial cell density were carried out postoperatively. CONCLUSION: This case shows the potential problem of corneal graft assessment before transplantation. An examination of the donor's cornea before its removal with a portable slit lamp could make graft quality evaluation safer.

[Pseudokeratoconus and ocular rosacea]. / Pseudo-kératocône et rosacée oculaire.

Photokeratoscopy analysis of the anterior curve of the cornea can detect keratoconus, particularly in the early stages of the disease. Nevertheless, all irregular astigmatisms are not related to keratoconus. We report here several cases of patients presenting high asymmetric astigmatism with features of keratoconus, although the clinical examination suggests corneal disease related to rosacea.

Effects of alumina and zirconium dioxide particles on arachidonic acid metabolism and proinflammatory interleukin production in osteoarthritis and rheumatoid synovial cells.

We describe a model which can be used for in vitro biocompatibility assays of biomaterials. We studied the in vitro response of human osteoarthritis or rheumatoid arthritis fibroblast-like synoviocytes to Al2O3 or ZrO2 particles by analysing the production of interleukin-1 (IL-1) and interleukin-6 (IL-6) and the metabolism of arachidonic acid via lipoxygenase and cyclo-oxygenase pathways. Our results show that, in these cells and under our experimental conditions, Al2O3 and ZrO2 did not significantly modify the synthesis of IL-1 and IL-6 or the metabolism of arachidonic acid.

A plant steroid, diosgenin, induces apoptosis, cell cycle arrest and COX activity in osteosarcoma cells.

Cyclooxygenases (COXs) are key enzymes in the conversion of arachidonic acid into prostanoids which are involved in apoptosis and inflammation. Two distinct COXs have been identified: COX-1 which is constitutively expressed and COX-2 which is induced by different products such as tumor promoters or growth factors. Previously, we demonstrated that a plant steroid, diosgenin, was a new megakaryocytic differentiation inducer of human erythroleukemia cells. In our study, we investigated the effect of diosgenin on the proliferation rate, cell cycle distribution and apoptosis in the human osteosarcoma 1547 cell line. The effects of this compound were also tested on COX expression and COX activities. Diosgenin treatment caused an inhibition of 1547 cell growth with a cycle arrest in G1 phase and apoptosis induction. Moreover, we found a correlation between p53, p21 mRNA expression and nuclear factor-kappaB activation and we observed a time-dependent increase in PGE2 synthesis after diosgenin treatment.

Dose-dependent modulation of apoptosis and cyclooxygenase-2 expression in human 1547 osteosarcoma cells by NS-398, a selective cyclooxygenase-2 inhibitor.

A selective cyclooxygenase-2 (COX-2) inhibitor, NS-398, was shown to produce an anti-proliferative and pro-apoptotic effect on different types of cell lines. We describe the presence of COX-1 and COX-2 pathways in the human osteosarcoma 1547 cell line, as well as the conflicting effects of NS-398 (10, 50 and 100 microM) on programmed cell death, PGE2 release and COX-2 expression in 1547 cells cultured under apoptotic conditions. We demonstrate a link between the effects of 10 and 100 microM NS-398 on cell apoptosis, PGE2 release, and expression of COX-2 in 1547 cells undergoing apoptosis. At 10 microM, NS-398 acted as a selective COX-2 inhibitor moderately increasing apoptosis without any effect on COX-2 expression. In contrast, at 100 microM, NS-398 induced a cell cycle slowing or arrest, strongly enhanced COX-2 expression which was associated with a high PGE2 release and a marked decrease in apoptosis. This latter property of NS-398 at 100 microM in 1547 human osteosarcoma cells is novel compared to the described NS-398 pro-apoptotic effect on other cell lines.

Enhanced apoptosis in retrovirally transfected osteosarcoma cells after exposure to sodium butyrate.

We investigated the effects of sodium butyrate (NaBu) on two retrovirally transfected osteosarcoma cell lines (1547-TK and 1547-LacZ cells) compared to the corresponding untransfected cell line. The first finding was an inhibitory effect only on the proliferation of both transfected cell lines. This antiproliferative effect was associated with apoptosis induction, which was detected using techniques that monitor either characteristic biochemical or morphological processes. Our findings show that 1547-TK and 1547-LacZ cells were much more sensitive to NaBu treatment than untransfected 1547 cells as concerns both proliferation and apoptosis induction.

Linoleic acid peroxidation by Solanum tuberosum lipoxygenase was activated in the presence of human 5-lipoxygenase-activating protein.

The present investigation describes the ability of human 5-lipoxygenase-activating protein (FLAP) to activate a plant 5-lipoxygenase. The presence of an active recombinant human FLAP in the 100000xg membrane fraction of infected Sf9 cells led to a specific increase in 9-hydroperoxyoctadecadienoic acid (9-HPOD) synthesis (+68%) or in 5-hydroperoxyeicosatetraenoic acid (5-HPETE) synthesis (+68%), after action of Solanum tuberosum tuber 5-lipoxygenase (S.t.LOX) on linoleic acid (natural plant lipoxygenase substrate) or on arachidonic acid. On the contrary, the presence of non-transfected membranes obtained from non-infected Sf9 cells led to an inhibition of lipoxygenase activity. MK-886, a potent inhibitor of leukotriene biosynthesis, blocked the FLAP dependent S.t.LOX activation after preincubation with FLAP transfected membranes. In conclusion, this study demonstrates that a recombinant human FLAP can stimulate a lipoxygenase other than mammalian 5-lipoxygenase (S.t.LOX) by using different polyunsaturated fatty acids as substrates.