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Biomedical subjects

L Missotten

Publications and source records attributed to L Missotten.

At least 91 records · Page 5Linked to original sources
PubMed1992

In situ immunohistochemical analysis of cell adhesion molecules on human corneal endothelial cells.

Interaction of leucocytes with human corneal endothelial cells (HCECs) can be observed in several clinicopathological conditions, such as uveitis, keratitis, and corneal graft rejection. Since leucocyte-endothelial cell interactions involve various adhesion receptors we have analysed the expression and distribution pattern of the neural cell adhesion molecule (NCAM), the intercellular adhesion molecule-1 (ICAM-1), the vascular cell adhesion molecule-1 (VCAM-1), the endothelial leucocyte adhesion molecule-1 (ELAM-1), and the cluster of differentiation antigen-44 (CD44) on flat preparations of normal and organ-cultured HCECs. NCAM and ICAM were constitutively expressed on HCECs whereas VCAM-1, ELAM-1, and CD44 were absent from normal HCECs. However flat mounts of HCECs from organ-culture preserved corneas showed a mosaic-like distribution pattern of VCAM-1 and ELAM-1 positive cells and garland-like clusters of CD44 positive cells. We suggest that modulation of ELAM-1, VCAM-1, and CD44 expression on HCECs may contribute to the regulation of leucocytes-HCECs interaction in the case of anterior segment inflammation.

Aged↗
PubMed1992

Sudden blindness in a child: presenting symptom of a sphenoid sinus mucocele.

A 10-year-old girl with no nasal or respiratory symptoms developed a headache lasting a few hours. The next day she became totally blind in the right eye and over 5 days vision in the left eye deteriorated to bare light perception. The diagnosis of a sphenoid sinus mucocele was made radiologically and drainage via an endonasal sphenoidectomy produced 12 ml of brownish fluid. Endoscopic biopsy of the wall confirmed the diagnosis of a mucocele. Steroid treatment was given postoperatively, but vision recovered to 6/12 in the left eye only. The importance of urgent clinical diagnosis and treatment is stressed.

Acute Disease↗
PubMed1992

A long term clinical trial of carteolol in the management of glaucoma. Belgian Carteolol Study Participants.

Carteolol is a nonselective beta-blocker with intrinsic sympathomimetic activity (I.S.A.). A multicenter trial was started to check if the theoretical advantages of this new drug could also be confirmed in a clinical setting. The intraocular pressure (I.O.P.), the visual field and the adverse reactions were evaluated at day 8, 60, 360 and 960. The results of this study demonstrate that carteolol effectively lowers the I.O.P. with minimal adverse side effects in previously treated as well as untreated patients.

Adult↗
PubMed1992

The use of the first locally manufactured epikeratolens for keratoconus in Leuven.

We adapted a lathe to the production of keratolenses. A cornea is mounted on a chuck and frozen at minus 40 degrees C. Hereafter we can cut the desired posterior radius and diameter. The first plano keratolens produced was used to correct keratoconus. The favourable result encouraged us to manufacture keratolenses for the correction of refractive errors.

Adult↗
PubMed1991

Bilateral blindness in cavernous sinus thrombosis.

An unusual case of bilateral blindness secondary to a cavernous sinus thrombosis is reported. A woman who had undergone reconstructive surgery after tumor resection of the floor of the mouth, was readmitted 1 month later with bilateral proptosis and signs of sepsis. There were no complaints of blurred vision. A CT-scan of the orbits demonstrated a bilateral cavernous sinus thrombosis (CST) secondary to an infection at the skull base behind the myocutaneous flap. A few days later she became blind, due to bilateral central retinal artery occlusion and anterior ischemic optic neuropathy. The general critical condition improved with intensive AB treatment. The patient recovered well without neurological defects apart from her permanent bilateral blindness. There were no signs of tumor recurrence. To our knowledge, this is the first documented case of bilateral blindness in a patient suffering from CST.

Blindness↗
PubMed1991

Morphologic and immunophenotypic heterogeneity of corneal dendritic cells.

The morphology, distribution and immunophenotype of corneal dendritic cells was investigated in frozen sections of normal human cornea using a panel of monoclonal antibodies (mAbs). Throughout the cornea, epithelial dendritic cells were labelled with mAbs LN2 and LN3, directed to HLA-DR-associated antigens. In the peripheral corneal and limbic epithelium, dendritic cells with long cytoplasmic processes in a suprabasal position were identified as being OKT6+, whereas in the central corneal epithelium, dendritic cells with short processes were located basally and corresponded to the OKT6- phenotype. Throughout the corneal stroma, LN2+ LN3+ OKT6- spindle cells were found. This study discloses that corneal dendritic cells display considerable phenotypic and morphologic heterogeneity. We suggest that this heterogeneity is partly due to local inductive effects of peripheral corneal basal cells.

Antibodies, Monoclonal↗
PubMed1991

Unilateral congenital nasolacrimal mucocele.

A case of a congenital nasolacrimal mucocele is reported. This very uncommon finding presents usually with a diagnostic triad on CT: an intranasal cystic mass, a dilated nasolacrimal duct and lacrimal sac.

Female↗
PubMed1991

Patterns of glutamate-like immunoreactive bipolar cell axons in the retina of the marine teleost, the dragonet.

Oblique 1 microns-sections through the dorsal inner plexiform layer of the light-adapted dragonet retina were processed for postembedding, silver-enhanced immunogold labeling after incubation with a glutamate-specific antiserum. Light microscopy showed strongly immunolabeled boutons grouped into distinct square patterns. These patterns were compared with the successive grids of bipolar axonal boutons revealed by electron microscope analysis of serial, oblique sections through the entire dorsal inner plexiform layer. With one exception, all types of patterned bipolar synaptic boutons could be clearly identified in the immunoreactive staining pattern. The elevated levels of endogenous glutamate in most bipolar synaptic boutons suggest that the large majority of bipolar cell types use glutamate as their neurotransmitter. However, some bipolar synaptic boutons displaying low levels of glutamate indicate that a small number of bipolar cells may contain another neuroactive substance.

Animals↗
PubMed1991

Retrolental white mass.

From 1985 till 1990 twenty-three children aged seven weeks to six years presented with a retrolental white mass. Six children had retinoblastoma, six Coats' disease, five retinopathy of prematurity, four persistent hyperplastic primary vitreous, one cysticercosis and one retinal detachment. Retinoblastoma and Coats' disease was only seen in children over eight months, whereas persistent hyperplastic primary vitreous and retinopathy of prematurity all presented before the age of six months. Differentiation between Coats' disease and retinoblastoma is not always easy. Most helpful for the diagnosis is to perform funduscopy under general anaesthesia with special attention to the vasculature. Ultrasounds are helpful, but can give confusing results. Cytological analysis of subretinal fluid is useful in Coats' disease.

Child↗
PubMed1991

Epikeratoplasty for the correction of aphakia and keratoconus.

Epikeratoplasty is a form of refractive corneal surgery in which a lens made of human corneal tissue is sutured onto the deepithelialized surface of the patient's cornea. The indications of epikeratoplasty for the correction of aphakia and keratoconus are discussed. We also report the results of epikeratophakia for the correction of aphakia in eight eyes and for the treatment of keratoconus in five eyes.

Adolescent↗
PubMed1991

Heterogeneous induction of major histocompatibility complex class II antigens on corneal endothelium by interferon-gamma.

The expression and distribution of major histocompatibility complex (MHC) class II gene products, HLA-DR, HLA-DQ, and the HLA-DR invariant chain, were studied on flat mounts of human corneal endothelial cells (HCEC) after in vitro incubation of donor corneas with interferon-gamma (IFN-gamma), interleukin-1 (IL-1), and IL-6, using a sensitive immunoperoxidase technique with monoclonal antibodies. Control HCEC and endothelium treated with IL-1 or IL-6 completely lacked MHC class II antigens. After treatment with 50 U/ml, 100 U/ml, 500 U/ml, and 5000 U/ml of human IFN-gamma, a mosaic-like, patchy staining for all MHC class II products was observed: part of the HCEC showed membranous and/or cytoplasmic positivity; other endothelial cells were negative. In addition, a dose-dependent response to IFN-gamma was observed: the proportion of cells expressing class II products rose with increasing doses of IFN-gamma. The induction of MHC class II antigen expression on HCEC by IFN-gamma was completely inhibited by the addition of a neutralizing antibody directed to IFN-gamma but not by IL-1 beta. The significance of these findings with respect to corneal transplantation immunology is discussed.

Antibodies, Monoclonal↗
PubMed1991

Orbital myositis following an upper respiratory tract infection: contribution of high resolution CT and MRI.

A case of isolated unilateral extraocular muscle myositis following an acute upper respiratory tract infection is reported. Painful eye movements, restricted eye motility and exophthalmus but a normal visual acuity are the most important clinical findings. High resolution contrast enhanced CT and MRI are the imaging modalities of choice to differentiate from other orbital pathologies. The solitary enlarged muscle was clearly seen on both the contrast enhanced CT and the MR examination. Preseptal cellulitis was better seen on MRI, whereas high resolution CT was superior in the demonstration of periscleritis. Graves' ophthalmopathy and orbital cellulitis first have to be excluded. Corticosteroids are the therapy of choice in orbital myositis. A control, contrast enhanced CT after 4 weeks showed an almost normal muscle.

Adrenal Cortex Hormones↗
PubMed1991

Distribution of very late activation integrins in the human cornea. An immunohistochemical study using monoclonal antibodies.

There is growing evidence that cellular adhesion mechanisms characterized by cell-cell and cell-matrix interactions are a fundamental process in the immunobiology of the cornea. Interactions with various extracellular matrix components are mediated by the very late activation (VLA) subgroup of the integrin superfamily of adhesion molecules. The six different VLA dimers known thus far consist of a common beta 1 subunit and a variable alpha (1 to 6) subunit. They serve as receptors for laminin (alpha 3 and alpha 6), collagen (alpha 2 and alpha 3), and fibronectin (alpha 4 and alpha 5). Using in situ immunohistochemistry and monoclonal antibodies, the distribution of the common beta 1 and the variable alpha-chains of VLA molecules was studied in normal human cornea and in cases with scarring or subepithelial/retrocorneal fibrous tissue. Epithelial cells were VLA-beta 1 and VLA-alpha 2, -alpha 3, -alpha 4, -alpha 5, and -alpha 6 positive. This is consistent with their intercellular adhesion and may aid in their attachment to the basement membrane which is composed of collagen, laminin, and fibronectin. Keratocytes in normal stroma expressed only the common beta 1-chain and no detectable alpha-chains. In regions of scar or fibrous tissue, however, an upregulated expression of the alpha-chains was detected. The VLA- alpha 1, -alpha 3, -alpha 4, and -alpha 5 were expressed in young fibrous tissue; in older lesions, VLA- alpha 1, -alpha 2, -alpha 3, -alpha 4, and -alpha 5 could be detected. The corneal endothelium showed a strikingly strong positivity for all VLA integrins.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1990

Glutamate-like immunoreactivity in the retina of a marine teleost, the dragonet.

The localisation of endogenous glutamate in the dragonet retina was investigated by light microscopic postembedding silver-enhanced immunogold labeling after incubation with an anti-glutamate antiserum. Rod and cone inner segments and synaptic terminals, as well as the inner plexiform layer, are moderately labeled. Bipolar cells and ganglion cell bodies show strong labeling. In the dorsal inner plexiform layer, the levels with square-patterned bipolar synaptic boutons can be identified by their prominent glutamate-immunoreactivity. These results support the idea that the majority of the neurons that constitute the direct, centripetal pathways through the retina use glutamate as their neurotransmitter.

Animals↗
PubMed1990

Expression of MHC class II antigens and immunoglobulin M by the corneal epithelial cells in herpetic keratitis.

The corneal buttons obtained from 4 patients with active epithelial and stromal herpetic keratitis were studied with routine microscopy and immunohistochemistry. We used an immunoperoxidase technique with monoclonal antibodies directed against Langerhans cells, lymphocyte subsets, MHC products and immunoglobulins A, G, M and D. The epithelium and stroma contained an inflammatory infiltrate composed of polymorpho-nuclear leukocytes, dendritic cells, B-lymphocytes and T-lymphocytes (helper/inducer and suppressor/cytotoxic subsets). The epithelial cells of all the corneal buttons expressed MHC class II antigens. IgM was bound to the membrane of the epithelial cells in 3 specimens. HSV antigenic material was localized in the epithelial cells and in the stromal keratocytes by a direct immunofluorescence technique. Our data suggest that cell-mediated as well as antibody-mediated immune responses are involved, with a possible role for an autoimmune mechanism in the pathogenesis of this condition.

Adult↗
PubMed1990

Subretinal neovascular membranes associated with chronic membranoproliferative glomerulonephritis type II.

Subretinal neovascular membranes were observed in three patients with chronic membranoproliferative glomerulonephritis type II (dense deposit disease). The first signs of glomerulonephritis occurred at respective ages of 13, 10 and 10 years; subretinal neovascular membranes were noted at respective ages of 25, 32 and 32 years. All patients had bilateral, widespread retinal pigment epithelial abnormalities. Our findings indicate that subretinal neovascularization is a complication of dense deposit disease. In one patient, the early recognition and laser treatment of an extrafoveal subretinal neovascular membrane prevented further loss of vision.

Adolescent↗
PubMed1990

Cytoskeletal filament typing of human corneal endothelial cells.

Flat mounts of human corneal endothelial cells (HCECs) were examined immunohistochemically by using a wide assortment of monoclonal antibodies against the five classes of intermediate filaments (IFs) and actin and myosin. HCECs showed uniform immunostaining with monoclonal antibodies against the 40-kD (CK 19) and 45-kD (CK 18) cytokeratin (CK). Only part of the endothelial cells reacted with monoclonal antibodies against the 52-kD (CK 8) and 54-kD (CK 7) cytokeratin polypeptides and with monoclonal antibodies against vimentin. Monoclonal antibodies against the low- and middle-molecular-mass neurofilament proteins produced positive staining of all HCECs. No positivity was obtained with antibodies against desmin or glial fibrillary acidic protein. In addition, positive immunostaining with monoclonal antibodies against actin and slow myosin demonstrate that these proteins form part of the cytoskeleton of HCECs. The results of this study show that immunostaining of flat cell preparations is very useful for studies on HCECs. HCECs display an unusual combination of cytokeratin IFs and neurofilaments, together with vimentin, and are heterogeneous with respect to their IF makeup. These findings are discussed in relation to the presumed origin of HCECs.

Actins↗