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Biomedical subjects

A Patey

Publications and source records attributed to A Patey.

10 recordsLinked to original sources
PubMed1986

Quantitative analysis of tight junctions during ciliary epithelium development.

The tight junctions of the ciliary epithelium constitute the main morphological counterpart of the blood-aqueous barrier. Although well-known in the adult, they have only been poorly studied during the morphogenesis of the ciliary processes. We thus analysed them during this period in order to detect whether any changes appear in their general pattern. In the rat, results show that during ciliary body development, the junctional depth and the number of superimposed junctional fibrils decrease, the P-face intramembranous particle density within and outside the junctional domains increase, and particular structures, namely the 'complex strands', are numerous at the early stages and become rare in the adult. Thus, the tight junctions appear as non-stable structures during ciliary-body development and these modifications in their morphology may correspond to changes in barrier properties during the development of this tissue.

Animals↗
PubMed1986

Drug-induced cicatricial pemphigoid affecting the conjunctiva. Light and electron microscopic features.

Cicatricial pemphigoid (CP) is a chronic inflammatory disease which can affect the conjunctiva. It is a slowly progressive disorder of unknown but presumed autoimmune etiology. Pseudopemphigoid, or CP associated with ocular drug administration, has also been described. These cases, which appear clinically indistinguishable from unilateral idiopathic CP affecting the conjunctiva, have been related to the use of echothiophate iodide, pilocarpine, idoxuridine, and epinephrine. We report the histopathologic and ultrastructural characteristics of 22 biopsies from ten patients with iatrogenic CP following the use of various ocular drugs. All patients presented with clinically obvious, active CP affecting the conjunctiva. Light microscopy and electron microscopy revealed findings identical to those previously reported for idiopathic CP of the conjunctiva: squamous metaplasia, increased numbers of desmosomes, basal lamina modifications suggestive of damage and attempted repair, subepithelial inflammatory cell infiltration, and diminished intravascular space within the stroma. These patients responded to immunosuppressive therapy. The authors wonder if it is possible that these patients were destined to develop CP, but that with topical ocular drug use, a more rapid emergence of the chronic cicatrizing feature of CP developed.

Aged↗
PubMed1986

Quantitative autoradiography of multiple 5-HT1 receptor subtypes in the brain of control or 5,7-dihydroxytryptamine-treated rats.

The distribution of the 2 main types (A and B) of 5-HT1 binding sites in the rat brain was studied by light-microscopic quantitative autoradiography. The 5-HT1A sites were identified using 3H-8-hydroxy-2-(N-dipropylamino)tetralin (3H-8-OH-DPAT) or 3H-5-HT as the ligand. In the latter case, it was shown that 3H-5-HT binding to 5-HT1A sites corresponded to that displaceable by 0.1 microM 8-OH-DPAT or 1 microM spiperone. The "non-5-HT1A" sites labeled by 3H-5-HT in the presence of 0.1 microM 8-OH-DPAT corresponded mainly to 5-HT1B sites. 5-HT1A binding was notably high in limbic regions (dentate gyrus, CA1 and CA3 hippocampal regions, lateral septum, frontal cortex), whereas 5-HT1B binding was particularly concentrated in extrapyramidal areas (caudate nucleus, globus pallidus, substantia nigra). Except in the latter regions, where only one class of 5-HT1 sites was found, both 5-HT1A and 5-HT1B sites existed in all areas examined. The selective degeneration of serotoninergic neurons produced by an intracerebral injection of 5,7-dihydroxytryptamine was associated only with a significant loss of 5-HT1A binding to the dorsal raphe nucleus (-60%) and of 5-HT1B binding to the substantia nigra (-37%). These results are discussed in relation to the possible identity of 5-HT1A and/or 5-HT1B sites with the presynaptic 5-HT autoreceptors controlling nerve impulse flow and neurotransmitter release in serotoninergic neurons.

5,7-Dihydroxytryptamine↗
PubMed1984

Keratoconus and normal cornea: a comparative study of the collagenous fibers of the corneal stroma by image analysis.

Using an automatic image analysis technique, we studied the characteristics of the collagenous fibers of the corneal stroma of keratoconus at different stages of development. The clear portions of keratoconus specimens were studied at three different levels: anterior, middle, and posterior. The parameters obtained were compared with those of a normal adult cornea with the purpose of determining which ultrastructural alterations were caused by the appearance and progression of keratoconus.

Adolescent↗
PubMed1983

[Antiviral agents and cicatrization of the corneal stroma].

Infection of the cornea due to herpes simplex virus continues to be a problem for ophthalmologists despite treatment of the disease with antiviral drugs. These drugs are known to produce some toxic effects and prolonged administration is sometimes necessary. Using tensile strength measurements to assess tissue repair, healing of a 5 mm perforating corneal stromal incision was measured after treatment with different antiviral drugs four times a day for eighteen postoperative days. Results suggest that 3% adenine arabinoside, 3% acycloguanosine, 1% trifluorothymidine, and 1% iododesoxycytidine ointments do not delay (p greater than 0.05) normal stromal healing.

Acyclovir↗
PubMed1983

[PHZ-102 (epidermal growth factor) and cicatrization of the corneal epithelium].

Epidermal Growth Factor is a polypeptide isolated from mouse submaxillary glands and evaluated by histological studies. The healing of 7.3 mm diameter central corneal epithelial wounds after treatment with epidermal Growth Factor was measured by standardized photography. The results suggest that topically-administrated Epidermal Growth Factor, at a frequency of four (p less than 0.02) and six (p less than 0.001) times daily, significantly increases the corneal epithelial healing rate compared to the vehicle control. Histological examination of the control eyes enucleated after seven days of treatment showed an epithelium four to five layers in thickness. The basal cells had a round shape and round, centrally-positioned nuclei. The Epidermal Growth Factor treated group (six times daily) had an epithelial thickness of five to six layers. The basal cells were taller and more tightly-packed with oval nuclei oriented towards the apex of the cell.

Animals↗
PubMed1983

[Sclerocornea. Ultrastructural and morphologic study].

A 6 month old white male infant had bilateral congenital diffuse sclerocornea. A penetrating keratoplasty was performed in his left eye. Histologic examination by electron microscopy demonstrated: the presence of vacuoles in the superficial epithelial layer, the absence of Bowman's membrane, a disorganization of collagen fibers and lamellae more prominent in the middle stroma, and an extremely thin Descemet's membrane. A comparison, using an automatized image analysis method, was carried out between the stroma of sclerocornea and a normal cornea. Morphometric analysis of the collagenous fibril's diameter and the interfibrillar distances demonstrated a statistically significant difference (p less than 0.001) between the two corneas examined.

Cornea↗
PubMed1983

[Morphologic and quantimetric study of the surface of the corneal epithelium].

Studies were conducted to attempt to demonstrate the presence of a twofold cell population in the superficial cells of the corneal epithelium as seen on scanning electron microscopy. Transmission electron microscopy was used to compare corneas washed with acetylcysteine with unwashed corneas after staining of surface mucosubstances with ruthenium red. Washing was found to remove some of the mucus film deposited by the tears on the epithelial surface. In contrast, both specimens showed a layer of substance, stained by the ruthenium red and more or less abundant according to the cell, which was thick enough to mask the microvillosities on scanning microscopy. Two distinct layers were observed. One of constant thickness was a thin layer which followed the outline of the microvillosities exactly but did not mask them. This was formed of glycocalix itself, a substance of cellular origin which was visible on developed cell surfaces even before desquamation of adjacent cells occurred. The other layer was more heterogeneous and attached to the cell wall, but it cannot be removed by washing with acetylcysteine. It also appeared on developed cell surfaces before adjacent cells had desquamated. The substance could arise from the lacrimal film or the necrozed remnants of superficial cells. It appears to increase in quantity with aging of the cell, and is capable of infiltrating between the microvillosities giving the appearance of dark cells on scanning microscopy. The different cells noted on scanning microscopy vary only by the amount of this mucin-like substance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗