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Biomedical subjects

L Missotten

Publications and source records attributed to L Missotten.

At least 109 records · Page 6Linked to original sources
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↗
PubMed1990

[Detachment with giant tear].

The authors report their experience in treating 39 eyes in 36 patients suffering a retinal detachment with giant tear. Follow-up has been from 7 to 54 months with a mean of 25 months. The different surgical procedures are compared and evaluated.

Adolescent↗
PubMed1990

Trabeculectomy: a retrospective long-term follow-up study.

The results of the surgical procedure of trabeculectomy as performed in our hospital on 100 eyes (67 patients) are presented. At the end of the follow-up period, with a range of 1 to 5 years and a mean follow-up of 36 months, there was an overall success rate of 68%. Criteria for success included no further visual field loss or disc damage, and no glaucomatous etiology for a decrease in visual acuity. Only in half of failure cases an IOP of more than 20 mmHg was recorded at least once during the follow-up period. Hyphaema, resolving most of the time in less than 7 days, was the most frequent postoperative complication (66%), followed by hypotomia (29%). Progression of lensopacities occurred in 22% of eyes.

Female↗
PubMed1990

Physiology of the lacrimal system.

The precorneal tear film has a three-layered structure: the superficial lipid layer, the underlying aqueous layer and the innermost mucous layer. Some experiments were performed to demonstrate the existence and the destination of each of those layers.

Humans↗
PubMed1990

Silicone intubation for congenital obstruction of nasolacrimal ducts.

In children aged 3 months or older lacrimal probing was performed to cure nasolacrimal duct obstructions. In 56 cases where this procedure failed a silicone tube was inserted. The results were favourable in 47 cases. Children with facial malformations and those with a narrow nasolacrimal duct however proved to be poor candidates for silicone tube insertion.

Child↗
PubMed1989

Immunopathological study of vernal keratoconjunctivitis.

The in situ immune reaction occurring in the conjunctival tissues of patients with vernal keratoconjunctivitis was studied using immunohistochemical techniques and a panel of monoclonal and polyclonal antibodies. Our data point to a complex immunopathogenesis of the disease. The anaphylactic response was demonstrated by the presence of many eosinophils and mast cells showing membranous IgE staining in the epithelial and stromal inflammatory infiltrate. IgE+ plasma cells were rare or absent in the conjunctival tissues and around the acini of accessory lacrimal glands, suggesting that IgE is not produced locally in the conjunctival tissues. A humoral immune response was evidenced by the presence of small B-lymphoid follicles, scattered B-lymphocytes, and many plasma cells in the stromal inflammatory infiltrate. IgA+ and IgG+ plasma cells were of more or less equal numbers and outnumbered IgM+ plasma cells. The majority of plasma cells around the acini of accessory lacrimal glands were IgA+. A role played by cell-mediated immunity was evident from the presence of scattered stromal T-lymphocytes and many dendritic cells in the epithelium and stroma. Some stromal dendritic cells carried IgE on their surfaces.

Adolescent↗
PubMed1989

Immune cells in a case of postherpetic marginal trophic ulcer.

The corneal surface was examined by means of replica histology, and the excised limbic conjunctiva was examined by routine histological and immunohistochemical methods with monoclonal antibodies directed against major histocompatibility class II antigens, lymphocyte subsets, Langerhans cells (HLA-DR, OKT4-Leu3a, OKT8, BA1, B1, and OKT6) and immunoglobulins A, G, M, and D. The findings were compared with those found in normal conjunctiva. No inflammatory cells were present in the replica of the corneal surface. An inflammatory infiltrate composed of B lymphocytes and null cells, in addition to T lymphocytes, Langerhans cells, and polymorphs, was present in the epithelium as well as in the stroma of the limbic conjunctiva. The composition of the infiltrate points towards the involvement of cell mediated immunity as well as humoral immunity. No immunoglobulins were bound to the conjunctival epithelium.

Aged↗
PubMed1989

Immunopathology of trachomatous conjunctivitis.

Upper palpebral conjunctival biopsy specimens obtained from eight patients with active trachoma were examined by routine histological and immunohistochemical methods. The epithelium expressed class I major histocompatibility complex (MHC) products throughout and class II MHC products in the superficial layers. The epithelial inflammatory infiltrate consisted of polymorphonuclear leucocytes, macrophages, T lymphocytes, and dendritic cells. In the underlying stroma the inflammatory infiltrate was organised as B lymphoid follicles, and there was also a diffuse infiltrate consisting of plasma cells and scattered B lymphoid cells, dendritic cells, T cells, macrophages, and polymorphonuclear leucocytes. Each type of cell has its special location in the tissue. Plasma cells were located on a subepithelial band and as a dense infiltrate round the acini of accessory lacrimal glands. IgA+ plasma cells outnumbered IgG+ cells, whereas IgM+ and IgE+ cells were few. Our data provide good evidence for the presence of both humoral and cell mediated immune responses and a possible role for autoimmune mechanisms in the conjunctival tissues of trachoma patients.

Child↗
PubMed1989

Recombinant interferon-gamma induces HLA-DR expression on human corneal epithelial and endothelial cells in vitro: a preliminary report.

The effect of interferon-gamma on the expression in situ of major histocompatibility complex (MHC) products in human corneas was studied in vitro. Incubation for four days with 5 or 50 mg/l of Escherichia coli-derived recombinant human interferon-gamma resulted in the appearance de novo of MHC class II or HLA-DR antigens on variable numbers of corneal epithelial cells as well as on corneal endothelium, whereas it had no effect on the expression of MHC class I or HLA-ABC antigens. These results may help to explain the mechanism underlying the expression of HLA-DR antigens on corneal and limbal epithelium in various inflammatory eye diseases.

Cells, Cultured↗
PubMed1988

Incidence and clinical presentation of chlamydial keratoconjunctivitis: a preliminary study.

Using a direct immunofluorescent technique and monoclonal antibody, chlamydia trachomatis was detected in the conjunctival smears of 13 out of 47 patients presenting with conjunctivitis or keratoconjunctivitis (an incidence of 28%). Two patients presented with acute symptoms of few days duration, whereas the condition was chronic and of long duration in 11 patients. Conjunctival changes noted were upper and lower palpebral conjunctival follicles and papillae (11 patients), chemosis (5 patients), upper tarsal scar (2 patients) and pseudomembrane (one patient). Corneal involvement was detected in 9 patients and was manifested as micropannus (6 patients), multiple small epithelial punctate stains (3 patients), extensive pannus affecting the upper third of the cornea (2 patients), subepithelial punctate infiltrates similar to that of adenovirus infection (2 patients) and upper limbal follicles (one patient). Identification of chlamydia trachomatis in conjunctival smears by use of the monoclonal antibody is a simple, rapid and reliable laboratory procedure.

Acute Disease↗
PubMed1988

Phenotypic characterization of inflammatory cells in phlyctenular eye disease.

Phlyctenular conjunctival biopsy specimens obtained from seven patients presenting with ulcerated limbal phlyctens were examined with routine histology and immunohistochemistry using a panel of monoclonal and polyclonal antibodies and immunoperoxidase techniques. Large numbers of mononuclear phagocytes, dendritic Langerhans cells and polymorphonuclear leukocytes and moderate numbers of T-lymphocytes were observed in the epithelium. This infiltrate was most intense at the basal epithelial layers which expressed HLA-DR antigens. The underlying stromal inflammatory infiltrate was organized as perivascular cuffs and a scattered subepithelial infiltrate, and consisted of many mononuclear cells and poly-morphonuclear leukocytes. Among the mononuclear cells, monocyte derived cells dominated and included monocytes macrophages and dendritic cells. T-lymphocytes were present in moderate numbers, whereas B-lymphocytes and plasma cells, mostly of IgA class, were infrequent. These findings provided in situ immunohistochemical evidence that phlyctenular eye disease is the result of delayed type hypersensitivity immune response in which monocytes and monocyte derived cells play a central role.

Antibodies, Monoclonal↗
PubMed1988

Experimental chlamydial keratitis in rabbits. Correlation with chlamydia infected McCoy tissue culture cells.

Rabbit corneas were inoculated three times at weekly intervals with the agent of chlamydia trachomatis using the scratch method. Specimens of the corneal epithelium were obtained using the replica technique on the 1st, 2nd, 3rd and 4th day after each inoculation and at two weeks after the last inoculation. The development of chlamydial inclusions and the inflammatory cell response were monitored using Giemsa stain, acridine orange stain and direct immunofluorescent technique. Primary inoculation produced mild clinical disease associated cytologically with polymorphonuclear leucocytic cellular inflammatory response. Repeated inoculations produced more severe disease associated clinically with pannus formation and cytologically with the presence of lymphocytes and Leber cells in addition to polymorphonuclear leucocytes. Halberstaedter Prowazek inclusion bodies were detected in all the specimens. Additional intracytoplasmic and intranuclear inclusions of different morphological appearances were present. The cytological findings detected in the corneal epithelium of rabbits were correlated with the findings in McCoy tissue culture cells inoculated with chlamydia trachomatis.

Animals↗
PubMed1988

[Amplitude of accommodation in Zairian subjects].

The authors studied the amplitude of accommodation in Zairian patients who consulted the Ophthalmic Clinic of University of Kinshasa from February 24 to July 31, 1986. During this period, of 1326 Zairians seen, 159 (318 eyes) were included in this study. Patients with monocular visual acuities less than 10/10, or with ocular pathology, astigmatisms and anisometropias exceeding one diopter were excluded from the study. The mean age +/- SD was 32 years +/- 12 with a range of 10 to 58 years. There were 101 males and 58 females. The measurements were performed, once for each patient, with Osterberg Bino-Oculus apparatus according to the "push-up" method and the plus spherical method. The amplitude of accommodation decreased with the age. This decrease was more notable between 30 and 40 years. The age of onset of presbyopia calculated from the amplitude of accommodation according to the "push-up" method was 39 years. The values of the amplitude of accommodation obtained by the both methods could be superposed (p greater than 0.05). They were similar to those of black patients and were also inferior to the white patients obtained by other authors.

Accommodation, Ocular↗