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Biomedical subjects

L Missotten

Publications and source records attributed to L Missotten.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Congenital malformations of the eyeball and its appendices in Zaire].

OBJECTIVE: to determine the epidemiology of congenital eye malformations. METHODS: the records of 1740 patients (1913 eyes) with congenital eye malformations seen from 1962 through 1992 were reviewed. RESULTS: the prevalence rate of congenital eye malformations was 2.2%. Congenital cataract (38%), atresia of the naso-lacrimal duct (10%), congenital glaucoma (9%), congenital ptosis (8%), microphthalmos (8%), albinism of iris (8%), microcornea (7%) were the most frequent eye malformations. The common types of associated malformations included albinism, microcephaly, cardiopathy and anomalies of ears. CONCLUSION: the findings of this study were similar to those published in Europe and United States.

Abnormalities, Multiple↗
PubMed1994

Method for detection of conjunctival chlamydial infection and allergic conjunctivitis.

In this study 104 adult patients with chronic conjunctival irritation without obvious diagnosis were investigated by conjunctival scrapings. The smears were stained with May-Grünwald-Giemsa or fluorescein-conjugated monoclonal antibodies prepared against Chlamydiae. In 45 cases it was possible to make a correct diagnosis of Chlamydia infection (29%) or allergy (20%).

Adult↗
PubMed1994

Ocular findings in prematurely born children at the age of 12.

A group of 79 prematurely born children was assessed ophthalmologically at the age of 12 and compared with a group of 100 12 years old children born at term. Of the 79 children, results of neonatal eye examinations were available in 26 prematures (52 eyes). In 28 eyes no signs of retinopathy of prematurity (ROP) were detected (non-ROP group). In 24 eyes a stage 1 or 2 retinopathy of prematurity was present (ROB group). 75% of the children with ROP had an ophthalmological problem. Myopia (29%), hypermetropia (21%), astigmatism (37%) and strabismus (33%) were significantly higher. Considering the whole group of prematurely born children, there was more astigmatism (11%) and strabismus (13%). Preterm children, with or without ROP, are more prone to develop ocular problems.

Adolescent↗
PubMed1994

[The Farnsworth-Munsell 100 Hue test in the Bantu population. Preliminary results].

The purpose of this work was to establish in this first report the age standards of the Farnsworth-Munsell 100 hue in Zaire. The Farnsworth-Munsell 100 Hue test was performed in 132 normal subjects. All subjects were Zairian blacks aged from 20 to 49 years. The test was administered binocularly, once, to each subject. Subjects were divided in three age groups. The first age group had 35 subjects aged between 20 and 29 years, the second age group had 48 subjects aged between 30 and 39 years and the third 49 subjects aged between 40-49 years. The total error scores were 7.06 +/- 2.10 for the first age group, 9.03 +/- 1.80 for the second age group and 9.80 +/- 2 for the third age group. These results were aged related (r = 0.42, p inferior to 0.05). Scores of Zairian subjects in this study were higher when compared to those reported in Europe and U.S.A. Interpretation of results of the Farnsworth-Munsell 100 hue test must take in account this difference in ethnic origin.

Adult↗
PubMed1994

Silastic intubation for Canaliculus communis stenosis.

Silastic intubation was performed for Canaliculus communis obstruction in 32 cases. Two eyes showed additional impatent nasolacrimal duct and were not treated. The silastic intubation was performed by aid of a long, hollow blunt injection needle which allows us to check the patency of the lacrimal system once the stenosis of common canaliculus is perforated. The success rate for isolated silastic intubation was 70%, which is similar to the results of other often more invasive surgical techniques for Canaliculus communis stenosis.

Adult↗
PubMed1993

A subgroup of bipolar cells in human retina is GABA-immunoreactive.

The distribution of GABA in the perifoveal and the near and far peripheral region of human retina was studied with peroxidase anti-peroxidase immunocytochemistry applied on semithin epoxy resin sections. Among the labeled amacrine cells in these regions, four types can be identified: putative diffuse A2 amacrines, stratified semilunar amacrines, interstitial amacrines and small displaced amacrines. GABA-immunoreactive interplexiform cells and ganglion cells also occur. Contrary to previous post-embedding studies, our preparations show that some bipolar cells in the near and far peripheral region are GABA-immunopositive. This indicates that a number of bipolar cells in human retina does have an enhanced GABA content.

Eye Enucleation↗
PubMed1993

New aspects of dopaminergic interplexiform cell organization in the goldfish retina.

Dopaminergic interplexiform cells (DA-IPCs) in the goldfish retina have been reexamined by light and electron microscopic immunocytochemistry with antisera against dopamine (DA) or tyrosine hydroxylase (TH). Successful immunostaining with a specific anti-DA antiserum offers further direct support for DA-IPCs. Anti-DA immunocytochemistry in combination with [3H]-DA autoradiography shows 92% colocalization of the two markers, indicating that [3H]-DA autoradiography is a reliable technique for identification of DA-IPCs. Incubations with anti-TH antiserum show that immunoreactive DA-IPCs have a homogeneous distribution, with an average frequency of 71 +/- 8 cells/mm2 in retinas of 14-15 cm long goldfish. Their arrangement is distinctly nonrandom. Electron microscopy of TH-immunoreactive cell processes confirms that horizontal cell axons synapse onto DA-IPCs and adds the following junctional arrangements to the circuit diagram of the DA-IPC: 1) adjacent serial synapses between DA-IPCs, external horizontal cells, and putative glycinergic interplexiform cells, 2) junctional appositions between DA-IPCs and photoreceptor cells, 3) junctional appositions between neighbouring DA-IPCs, and 4) the "gap junctional complex," typically consisting of a DA-IPC process juxtaposed with a gap junction between horizontal cell axons. The gap junction is flanked by clusters of small, round vesicles and groups of electron-dense structures resembling intermediate filaments. These morphological results support the functional involvement of DA-IPCs in adaptive retinomotor movements and in horizontal cell gap junction modulation and/or dynamics. They also suggest particular interaction between the dopaminergic and the glycinergic IPC system in the outer plexiform layer of goldfish retina.

Animals↗
PubMed1993

Antioxidant activity of plasma from subjects with and without senile cataract.

The relationship between overall plasma antioxidant activity and senile cataract was examined in 148 subjects aged 37-90 years. Antioxidant activity of plasma from 52 control and 96 patients with senile cataract was determined by a method which measures the capacity of plasma to inhibit auto-oxidation of bovine brain homogenate. In contrast to previous studies which demonstrated a relationship between decreased levels of antioxidant components in blood and the occurrence of lens opacities, the present study does not show any significant difference between subjects with and without senile cataract.

Adult↗
PubMed1993

A new epithelial cell type in the human cornea.

PURPOSE: To study the expression of intermediate filaments in the human cornea. METHODS: Light and electron microscopic and immunohistochemical studies were performed on 20 corneas from subjects of various ages. RESULTS: A hitherto unrecognized epithelial cell population emerged from the immunohistochemical studies. Epithelial cells were invariably present in the superior cornea, whereas the nasal, temporal, and inferior segments almost lacked these cells. They were situated at the transition between peripheral cornea and limbus, and occurred as small groups in the basal epithelium. On electron microscopy, they were recognized by their marginated nuclear chromatin, large nucleoli, prominent bundles of intermediate filaments, and numerous hemidesmosomes and desmosomes. Immunohistochemistry on frozen sections revealed a unique intermediate filament make-up: ie, strong co-expression of vimentin and cytokeratin 19; other intermediate filaments, including cytokeratins 3, 4, 6, 7, 8, 10, 13, and 18 were negative. Finally, the cells lacked ultrastructural and immunohistochemical features of melanocytes, neuroendocrine cells, Langerhans' cells, and leukocytes. CONCLUSIONS: A new epithelial cell type in the human cornea is described with characteristic morphologic and immunohistochemical features. According to their particular segmental distribution, restricted localization at the junction between cornea and limbus, and expression of an "early" intermediate filament profile, it is tempting to speculate that they represent stem cells of the human cornea. Further studies are aimed to characterize their phenotype and function more extensively.

Aged↗
PubMed1993

A retinoblastoma with an unusual aspect in a 5-year-old girl.

A five-year-old girl presented with a white, semitransparent, slightly elevated retinal lesion in the left eye, with as most probable diagnosis retinoblastoma. Fluorescein angiography showed intraretinal vascular abnormalities and leakage. On computed tomography and ultrasound no calcifications were identified. As the tumor had grown, enucleation was performed and the diagnosis of retinoblastoma was confirmed by routine histology and by immunohistochemistry.

Child, Preschool↗
PubMed1993

The transitional zone between limbus and peripheral cornea. An immunohistochemical study.

PURPOSE: The authors investigated the phenotypic characteristics of basally located "transitional cells" in peripheral superior cornea, characterized previously by their coexpression of cytokeratin 19 and vimentin and their negativity for AE5. METHODS: Twenty adult human corneas were studied, using in situ immunohistochemical techniques and a panel of specific monoclonal antibodies against various surface and cytoplasmic molecules. RESULTS: The transitional cells shared staining characteristics with limbal basal cells in their expression of alpha 6 beta 4-integrin, metallothionein, AE1, and transferrin receptor. CONCLUSIONS: These "transitional" epithelial cells exhibit a unique phenotype differing from that of the surrounding basal epithelial cells in the peripheral cornea but analogous to that of limbal basal cells. These findings further corroborate the hypothesis that, at least from an immunohistochemical point of view, transitional cells in the superior peripheral cornea exhibit stem cell characteristics.

Aged↗
PubMed1992

Localization of the cytoadhesin integrins in the human cornea. An immunohistochemical study using monoclonal antibodies.

Cell-matrix interactions play a fundamental role in normal and pathological conditions. They can be mediated by the cytoadhesin subgroup of the integrin superfamily of adhesion molecules. Its members include the vitronectin receptor (VNR) and the platelet glycoprotein IIb/IIIa (GP IIb/IIIa). Both receptors are composed of an alpha-chain (alpha v and alpha IIb, respectively) coupled to a beta 3-chain. Using in situ immunohistochemistry and monoclonal antibodies, the authors studied the distribution of GP IIIa (common beta 3-chain), GP IIb/IIIa (alpha IIb-chain) and VNR (alpha v-chain) in normal and pathological corneal tissues. In the normal cornea, the limbal vascular endothelium was weakly alpha v-positive. Occasionally, faint and granular staining was seen in the epithelium. In the pathological samples, an upregulated expression of the alpha v-chain was noticed on the corneal epithelium as well as on fibroblasts and corneal endothelium. The alpha IIb and beta 3-chains were consistently absent. These data suggest that expression of the VNR-alpha v-chain in the human cornea is modulated by soluble factors released during inflammation and wound healing. Dissociation of expression of the alpha v and beta 3-chains suggests usage of an alternative beta-chain by the VNR-alpha v-chain.

Antibodies, Monoclonal↗
PubMed1992

A comparative immunohistochemical study of human corneotrabecular tissue.

Using in situ immunohistochemical techniques and a broad panel of antibodies directed against intermediate filament proteins, vascular endothelial markers, neuroectodermal/neuroendocrine markers, and monoclonal antibodies raised against human corneal endothelial cells (HCECs), a comparative phenotypical analysis was performed on HCECs, keratocytes, trabecular cells, and cells lining the canal of Schlemm. The coexpression of cytokeratins and neurofilaments by HCECs argues in favor of a neuroectodermal origin, which is further supported by the fact that they stain positive for neuron-specific enolase (NSE) and that they express neural cell adhesion molecules (N-CAM) at their surface. The expression of NSE and N-CAM also applies to the trabecular cells. The cells lining the canal of Schlemm were found to share many immunophenotypical features with vascular endothelial cells (i.e., factor-VIII-related antigen and BMA-120), rather than with HCECs. This was further supported by the reactivity of two monoclonal antibodies (i.e., 9.3 E and 5.52 H) that were raised against HCECs, and which labelled vascular endothelium and cells lining Schlemm's canal.

Animals↗
PubMed1992

Three types of GABA-immunoreactive cone horizontal cells in teleost retina.

Peroxidase-anti-peroxidase immunocytochemistry, applied on serial semithin epoxy resin sections, was used to examine the localization of endogenous GABA in horizontal cells in the retina of a marine teleost, the dragonet (Callionymus lyra L.). The immunostaining shows that not only the external H1 cone horizontal cells label with antibodies against GABA, but also the H2 and H3 cone horizontal cells in the inner nuclear layer. The distribution of the H1 cells corresponds to that of the single cones. They are square-patterned and in the dorsal retina their density equals 20,000 cells/mm2. The estimated density of the immunostained H2 and the H3 cells in the dorsal retina is 9500 and 1300 cells/mm2, respectively. The H2 and H3 cells are not geometrically arranged, but nearest-neighbor analysis shows that these horizontal cell types do have a very regular disposition. We suggest that GABA is the likely neurotransmitter substance used by all cone horizontal cell types in teleost retina.

Animals↗