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Biomedical subjects

B Delbosc

Publications and source records attributed to B Delbosc.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Immunolabelling of collagen types I, III and IV, laminin and fibronectin in the human lens capsule].

PURPOSE: To localize collagen types I, III, and IV, laminin and fibronectin in the anterior human lens capsule. MATERIAL AND METHODS: Twenty-one anterior capsules were sampled by capsulorhexis during extracapsular cataract extraction (mean age 71.5). All capsules were labelled by an immunostaining specific for each antibodies. Immunostaining of four capsules was revealed with immunoperoxydase and seventeen using indirect immunofluorescence. RESULTS: Labelling of collagen types I and III was observed throughout the entire thickness of the capsule for each technique, the strongest labelling was found in the base of the epithelial cells with immunofluorescence. Collagen type IV was observed at the base of the epithelial cells whichever technique was used. Laminin could be detected in the inner layer of the capsule, using immunoperoxydase or immunofluorescence. No specific labelling was found for fibronectin using the two techniques. CONCLUSIONS: Different kinds of collagens have been found in capsules, more particularly the type III. The latter does not appear on other ocular basement membrane. Because of this uneven distribution in the capsule's thickness, each collagen might have a specific function.

Aged↗
PubMed1996

[Grafting of the cornea and implants sutured to the sclera or anterior chamber. Comparative study on graft survival and endothelial cell loss].

PURPOSE: We studied the percentage of graft survival and endothelial cell loss after penetrating keratoplasty with scleral sutured posterior chamber lens compared with secondary anterior chamber lens. METHODS: The study concerned 46 patients divided into two groups: group I: 26 cases with scleral sutured posterior chamber lens; group II: 20 cases with anterior chamber lens. The postoperative Kaplan-Meir curve survival was established and cell loss assessed between graft cell density and postoperative cell density according to Sperling's method. RESULTS: After one year, cell loss was less important in group I (69.23%) than in group II (95%). However, after the first postoperative year, this difference decreases and becomes very slight at the fourth postoperative year. The percentage of cell loss during the first year is 44.6% in group I and is 41.8% in group II. After the first year, the percentage of annual cell loss is 3% in group I and ranges between 6 and 8% in group II. CONCLUSIONS: Except for age, there was no significant difference between the two groups preoperatively. This, it seems that the high postoperative intra-ocular pressure, more frequent in group I, was a poor prognosis factor for graft survival. After one year, results were similar in the two groups for graft survival, but in group I, the annual percentage cell loss was lower.

Adult↗
PubMed1995

[Organ culture preservation of the human cornea at +31 degrees C and risk of infection].

PURPOSE: In order to reduce the risk of infection, we analyzed each stage of conservation of human cornea in organ culture at +31 degrees C. METHODS: This epidomiological study was conducted in 266 human corneas preserved in organ culture between January 1991 and December 1993. There were 3 stages: In the period of preservation (analysis of the contaminated medium), Before clinical use of the graft (analysis of the preservation medium), After the penetrating keratoplasty (analysis of the corneo-scleral rim and the transportation medium). The bacteriological media used were thioglycolate broth, trypticase soja and Sabouraud. RESULTS: In 266 storage media, 42 (15.7%) cultures are positive. The most commonly found organism was Staphylococcus aureus (21.4%). At the end of the conservation procedure, all of the cultures of the media were sterile (n = 165). After penetrating keratoplasty, 8 cultures were positive for the transportation medium and the corneo-scleral rim (5.1%), 3 cultures were positive for the corneo-scleral rim only (1.9%) and 5 cultures were positive (3.2%) for the transportation medium without contamination of the corneo-scleral rim. CONCLUSION: Preservation at +31 degrees C in organ culture of human corneas allows elimination of the contaminated or potentially contaminant corneas before an eventual transplantation. In our experience, the risk of infection is especially situated in the period of preservation which shows the insuffiency of the decontamination procedures or the antibiotical content of the medium and probably the virulence of the organisms in donors hospitalized for long period.

Anti-Bacterial Agents↗
PubMed1995

T-cell repertoire of normal, rejected, and pathological corneas: phenotype and function.

The specific immune mechanisms of corneal graft rejection are not completely understood. Recently, the technique of growing T-cell lines from rejected allografts using recombinant IL-2 has enabled the cells involved in allograft rejection to be recognized. In the present study, this method was applied for the extraction and propagation of T lymphocytes from rejected, normal, and diseased corneas. T-cell lines could successfully be grown from rejected and normal corneas, but not from corneas with keratoconus or pseudophakic bullous keratopathy. The phenotypic repertoire of the grown cells was studied by FACS scan analysis. Rejected corneas were invaded by a mixture of activated CD4+ and CD8+ T-cell lines, with one population being predominant. In normal corneas only activated CD8+ cells with cytotoxic function were cultured. No cells were obtained from diseased corneas. The in vitro function of cell lines was assessed by primed lymphocyte testing. The present study shows that the technique of propagating invading T-cell lines from organ grafts can be applied to human corneas, offering a new approach to understanding the immunological mechanisms occurring inside this immune tissue.

Antibodies, Monoclonal↗
PubMed1994

[T-lymphocyte population in the normal human cornea].

T-lymphocytes of the normal human cornea (10 donors) were studied from corneal fragments cultured in IL-2 medium. Their phenotypic repertoire was performed by FACS analysis using the following monoclonal antibodies: CD3, CD19, CD4, CD29, CD18, CD16, CD56, CD25, TCR alpha/beta, TCR alpha/delta. Functional analysis was done by proliferation assays (PLT). T cell growth was more often obtained from peripheral (n = 7/10) than central corneal parts (n = 3/10). Most of the cultured cells carried the CD8 marker, were activated (HLA-DR+) and had a cytotoxic function (CD 18+). All their T cell-receptors were alpha/beta type. No NK cells could be detected. No specific proliferation was observed when tested on a panel of HLA typed presenting cells. This study demonstrated activated T-lymphocytes in the normal human cornea. These activated, cytotoxic CD8+ lymphocytes could participate in the particular immunological characteristics of the eye.

CD8 Antigens↗
PubMed1993

[Physiology of the cornea: stromal hydration and its regulation].

The authors present an up-to-date review of stromal hydration of the cornea and its controlling mechanisms. Stromal hydration quantifies the water component of the stroma. Its regularization depends on different factors which were detailed as; swelling pressure, corneal endothelial and epithelial metabolic pumps and barriers, tear film evaporation and intraocular pressure. Finally, the authors present different clinical procedures for evaluating stromal hydration, such as, the fluorophotometry and hypoxic-stress. This study shows the importance of stromal physiology and the consequences of all surgical or pathological modifications.

Animals↗
PubMed1993

[Bacterial contamination of the anterior chamber and cataract surgery].

The authors report the results of bacteriologic cultures of the anterior chamber aspirate after cataract surgery. The results were positive for 15 cases (24%). Nine cultures were positive for 27 eyes operated by phacoemulsification and 6 cultures were positive for 35 eyes operated by extracapsular cataract extraction. The origin of these organisms is the normal bacterial flora of the conjunctiva and the inoculum size is very small. The most commonly identified organisms are coagulase-negative staphylococcus and propionibacterium acnes.

Anterior Chamber↗
PubMed1993

[Ultrastructural study of human cornea preserved in organ culture media at +31 degrees C].

Organ culture becomes a standard method of corneal graft preservation. The aim of the study was to evaluate the preservation injuries induced by organ culture. We examined 12 organ cultured human corneas. Corneas were preserved in the medium for 2 to 21 days. Corneas showed some abnormalities: numerous light vacuoles, mitochondrial swelling and increased cell thickness in all cells of the cornea, sloughing of the external and medium epithelial cell layers. We observed normal endoplasmic reticulum, Golgi apparatus and nucleus. These preservation injuries are moderate and reversible.

Aged↗
PubMed1991

[Organotypic culture of human corneal epithelium. Preliminary results].

The authors compared the growth of limbal and central explants removed from human cornea. Epithelial growth began on the third day, was greater during the first week and was subsequently slightly invaded by fibroblasts. This study demonstrated that peripheral corneal epithelial cells growth better than central cells. In this study, the cytologic and histologic features of the cells were examined. However, epithelial immunofluorescence staining by anti-cytokeratin antibodies was rather poor. This in vitro system may provide a suitable model for epithelial human corneal cell culture, allowing further biocompatibility studies.

Cell Division↗
PubMed1990

[HLA antigenicity of normal and pathological corneas].

Fresh human corneas and corneal buttons were studied for expression of HLA antigens. Using monoclonal antibodies in an indirect immunofluorescence assay, corneal layers were examined for class I (HLA-A, B, C) and class II (HLA-DR) histocompatibility antigens. Twenty-one human corneas were studied, 6 normal and 15 pathological: 4 buttons of allograft rejection, 9 buttons of pseudophakic bullous keratopathy. In fresh control corneas, HLA-A, B, C antigens were localized on corneal epithelium and on stromal keratocytes but were never found on endothelial cells. HLA-DR antigens were not detected on corneal epithelium, stroma or endothelium but were detected on Langerhans cells within epithelium and anterior stroma. At the corneal limbus, HLA class I-II antigens were expressed on vascular endothelium. HLA antigen distribution was modified in pathological corneas. Antigens HLA-A, B, C were induced on endothelial cells of rejected corneal allografts. Antigens HLA-DR were detected on epithelial cells, cells in the stroma of pseudophakic bullous keratopathy and also on endothelial cells of rejected corneal allografts. These results suggest that induction of class I and II antigen expression by inflammatory factors may occur in vivo. In rejected corneal allografts induction of HLA-DR antigen on corneal layers would intensify the process of rejection. This study and others have demonstrated the ability of modulation of HLA antigen expression on human corneal cells in vivo.

Cornea↗
PubMed1990

[Post mortem HLA phenotyping of donors of eyes. Evaluation of a serological method of microlymphotoxicity on lymphocytes and PHA lymphoblasts].

To increase the number of HLA typed corneas a microlymphocytotoxicity assay on lymphocytes and PHA lymphoblasts was investigated. A double immunofluorescence technique using magnetic beads coated with anti-T8 (for class I) and anti-DR (for class II) monomorphic antibodies was applied. Blood samples from 50 non selected donors were obtained. HLA class I and class II typing was possible in 74% of the cases. Using PBL's (Peripheral Blood Lymphocytes) HLA class I could be defined in 29 out of 50 Cases and class II in 15 out of 50 cases. On PHA blasts HLA class I and class II antigens could be defined in 32 and 33 out of 50 cases respectively. Mean time of culture was 10 days (6-20). No influence of donor age and post partum time could be observed. By combination of both methods a significant proportion of eye donors could be reliably typed within a short time.

Adult↗
PubMed1990

[Preservation of human corneas in organ culture: technical protocol].

Using organ-culture preservation human corneas were preserved up to 5 weeks in a modified tissue culture medium at 37 degrees C. The endothelial viability was examined after staining with trypan-blue 0.3%, after determination of endothelial cell density and cell loss and by light microscopy after staining with trypan-blue 0.3% and alizarin red 1%. The biochemical analysis of the medium (pH, glucose, lactate) has allowed the evaluation of three kinds of storage. The influence of time preservation on the endothelial viability and the metabolic conditions are determined. At the end of this study a clinical trial is proposed.

Cell Count↗
PubMed1990

[Preservation of human corneas in organ culture: results of a feasibility clinical protocol].

This study reports donor corneas stored at +37 degrees C in organ culture incubation. The follow up is 12 months. The graft survival is 92%. Two grafts are failed before 6 months. The mean control thickness is 0.54 mm and the mean endothelial cell density 1625 cells per mm2. A mean decrease in cell density of 40.6% is recorded. This study demonstrates that banked donor material can be successfully employed for corneal transplantation.

Cornea↗
PubMed1990

[Retinitis disclosing subacute sclerosing panencephalitis].

SSPE is a panencephalitis who involves children and who leads to death. It is due to a defective measles virus. Ophthalmologic features are frequent and may be the first manifestation of the disease. The most typical ocular involvement is retinitis which can be misdiagnosed as a toxoplasmosis.

Adult↗
PubMed1990

[Non-freeze myopic keratomileusis. Retrospective study of 27 consecutive operations].

27 consecutive cases of non freeze myopic keratomileusis (using Barraquer Krumeich Swinger Set) were performed by one surgeon on 22 patients in a retrospective study. 4 per operative complications were noticed. Visual acuity with and without correction, astigmatism before and after surgery were reviewed preoperatively, at 1 week, 1 month, 3 months, 6 months and 1 year postoperative. The preoperative myopia (mean +/- standard deviation) was -15.55 +/- 5.46 D, the average postoperative residual myopia was: at 1 week -0.43 +/- 3.58 D, at 1 month -1.18 +/- 4.15 D, at 3 month -4.44 +/- 4.80 D, at 6 month -5.43 +/- 5.51, at 1 year -6.95 +/- 4.81 D. Visual acuity without correction was always better postoperatively. The best visual acuity (with correction) was preoperatively 0.38 +/- -0.22 at 1 week postoperative 0.21 +/- 0.09, at 1 month 0.35 +/- 0.16, at 3 month 0.31 +/- 0.15, at 6 month 0.32 +/- 0.15, at 1 year 0.34 +/- 0.17. Further investigation is monitoring to assess the predictability and stability of non freeze keratomileusis.

Adult↗