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Biomedical subjects

H Saraux

Publications and source records attributed to H Saraux.

At least 19 recordsLinked to original sources
PubMed1995

[Uncommon ophthalmological involvement in chronic atrophic polychondritis].

OBJECTIVE: Report of two uncommon ocular manifestations of relapsing polychondritis (PR). METHODS: A 53 year-old woman presented with a uveal effusion. Diagnosis of PR was made 17 years later. A case of PR in a 41 year-old man is reported. The ocular manifestation was a pseudotumor of the lacrimal gland. CONCLUSION: The relapsing polychondritis must be known by the ophthalmologists. The ocular manifestations of this uncommon disease are significative and inflammatory.

Adult↗
PubMed1994

In vitro organotypic culture method to evaluate the biocompatibility of heparin-surface-modified intraocular lenses.

Using an organotypic culture method, we evaluated the biocompatibility of two kinds of intraocular lenses: conventional poly(methyl methacrylate) (PMMA) and heparin-surface-modified (HSM) PMMA. Chicken corneal endothelium from embryos incubated for 14 days was placed on an agar medium and covered with one of three types of materials: PMMA, HSM PMMA, and a control, Thermanox. Experiments at five different times measured cell migration, cell multiplication, and cell adhesion. Scanning electron microscopy showed a low level of corneal endothelial adhesion on the HSM IOL surface. There was a significant difference between the HSM and untreated lenses in migration surface and cell density, with the HSM lenses having better biocompatibility.

Animals↗
PubMed1994

Central nervous system control of intraocular pressure.

Normal intraocular pressure (IOP) is the result of an equilibrium between aqueous humor (AH) production, AH outflow and episcleral venous pressure. Most available antiglaucoma agents produce their effects by interacting with autonomic mechanisms (beta-blockers, epinephrine or parasympathomimetics). In contrast, the role of the central nervous system (brain and nerves) in the regulation of IOP remains unclear in view of the complex haemodynamic, metabolic or hormonal changes which occur under experimental conditions. In this paper, we discuss a basic understanding of the anatomic and physiological relationships between central nervous system and IOP and describe how the brain can affect functions in ciliary body and trabeculum meshwork.

Animals↗
PubMed1994

Autoradiographic distribution of the eye monoaminergic synaptic vesicles.

The ligand [3H]dihydrotetrabenazine ([3H]TBZOH), a tritiated derivative of the monoamine depleting agent tetrabenazine, has been reported to bind specifically to the transporter present on the membrane of monoaminergic synaptic vesicles. We have studied the pharmacological characteristics of [3H]TBZOH binding to rabbit eye sections and the anatomical distribution of [3H]TBZOH binding sites in rabbit, rat and human eyes by in vitro autoradiography. In rabbit eye sections, [3H]TBZOH binding bound to a single class of binding sites (Kd = 4.1 nM, Bmax = 30.6 fmol/mg protein). When animals were kept for various times after death before removal of the eyes, the mean density of [3H]TBZOH binding sites decreased to 94 and 93% of control values after 24 and 48 h, respectively. In both species, the topographical distribution of [3H]TBZOH sites shows a pattern of distribution similar to that of monoaminergic innervation of the eye. The present data demonstrate that [3H]TBZOH can be used for the identification and the quantitation of monoamine-containing neurons in the mammalian eye.

Aged↗
PubMed1994

Immunohistochemical and ultrastructural study of the cornea in Chandler's syndrome. Report of a case.

A corneal specimen obtained by surgery in a 55-year-old woman with Chandler's syndrome was studied by light and transmission electron microscopy as well as by immunocytochemistry. The pathologic features were abnormalities of the endothelially derived cells lining the posterior corneal surface with a fibrous material consisting of collagen fibrils, filaments and banded material similar to that found in the anterior part of Descemet's membrane observed between the endothelial cell layer and Descemet's membrane. The multilayered endothelial cell layer in our case was found to be strongly positive for cytokeratins K7 and KL1 and vimentin and negative for factor-VIII-related antigen, neuron-specific enolase, nerve tissue S-100 protein, epithelial membrane antigen, CD 68, actin and desmin. This immunohistochemical reaction pattern argues in favor of an epithelial origin for cells lining the endothelial cell layer in Chandler's syndrome.

Corneal Diseases↗
PubMed1994

[Microbiological safety and endothelial quality control during preservation of corneal grafts at +31 degree C].

Over a 10-month-period, 59 corneas were organ-cultured at + 31 degrees C and 7 were preserved at + 4 degrees C. Among the 59 organ-cultured corneas, 41% (24) were grafted and 25% (15) developed an infection during preservation. At the time of surgery, preservation medium and scleral rim were tested for microbiology. Infection during preservation was bacterial (80%, 12/15) and fungal (20%, 3/12). Scleral rims were sterile in 96% (24/25) of the grafted corneas preserved at + 31 degrees C but 34% (2/6) at + 4 degrees C (p < 0.01). Preservation media were sterile in 100% (24/24) of organ-cultures at + 31 degrees C but in 83% cases (5/6) of preservations at + 4 degrees C (NS). The percentage of endothelial dead cells increased with postmortem enucleation delay (r = 0.43; p = 0.03). The average endothelial cell loss during organ-culture was 11.2% (+/- 10.4). It correlated with endothelial density (r = 0.42; p = 0.04) and with percentage of endothelial dead cells (r = 0.43; p = 0.04) after enucleation. Organ-cultured at + 31 degrees C was able to assess graft sterility in almost 100% of the cases but corneas are lost due to infection. Graft sterility is not usually possible with preservation at + 4 degrees C.

Aged↗
PubMed1993

Vasoactive intestinal peptide/peptide histidine isoleucine mRNA in the eye and suprachiasmatic nucleus of normal and monocularly enucleated rats.

The localization of the messenger RNA (mRNA) encoding vasoactive intestinal peptide/peptide histidine isoleucine (VIP/PHI) in the rat eye was studied by in situ hybridization histochemistry using a synthetic 35S-labeled oligodeoxyribonucleotide. Among the layers of the retina, specific labeling was found in the soma of some cells in the innermost lamina of the inner nuclear layer. Occasionally, labeled cells were also present in the ganglion cell layer. No specific labeling was detected in any ocular structures other than the retina, including the cornea, iris, ciliary body, choroid, choriocapillaris, optic nerve and sclera. We also examined VIP/PHI mRNA expression in the suprachiasmatic nucleus (SCN) of the hypothalamus, which is the pacemaker of circadian rhythms and synchronizes them with the environmental light-dark cycle. High labeling was found in the ventrolateral part of the nucleus, which is the site of most projections from the retina. Monocular enucleation of rats at birth resulted in an increase of VIP/PHI mRNA expression in SCN ipsilateral to the removed eye after postnatal day 60. The discrete pattern of hybridization for VIP/PHI mRNA indicates that these two peptides are synthetized in rat retina and SCN and suggests that they may play a key role in the photic entrainment to the SCN regulating various circadian rhythms.

Animals↗
PubMed1993

Physiological roles of dopamine and neuropeptides in the retina.

The retina is a highly complex nervous tissue that converts light into patterns of electrical action potentials in order to process visual information. To carry out its function as a transducer and processor of visual information, the retina must be structurally and biochemically organized to send a coherent signal to the visual areas of the brain. In recent years, a number of biologically active substances have been demonstrated to be located within neurons in the retina. Most of them are thought to be involved in the modulation of the signal and its transmission to the brain through the optic nerve. The present paper attempts to summarize the immunocytochemical distribution and physiology of some neuronally localized substances in the mammalian retina, namely dopamine and neuropeptides.

Animals↗
PubMed1993

Evaluation of the Tono-Pen 2 and the X-Pert noncontact tonometers in cataract surgery.

The Oculab Tono-Pen and the X-Pert noncontact tonometers (NCTs) were compared to the Goldmann applanation tonometer in a consecutive series of 45 patients before and after cataract surgery. In the preoperative period, the mean value of the paired difference at intraocular pressure (IOP) measurements was -1.30 +/- 2.11 mm Hg (mean +/- SD) for the X-Pert NCT (X-Pert NCT minus Goldmann) and -0.19 +/- 2.56 mm Hg for the Tono-Pen 2 (Tono-Pen 2 minus Goldmann). In the postoperative period, this mean difference was 0.26 +/- 2.45 mm Hg for the X-Pert NCT and 0.87 +/- 2.83 mm Hg for the Tono-Pen 2. We found 87 and 67% of the X-Pert NCT and the Tono-Pen 2 readings to be within +/- 2 mm Hg of the Goldmann readings, respectively. In both preoperative and postoperative eyes, correlation coefficients between the readings of the three instruments were high (ranging from 0.84 to 0.96). Differences between the three tonometers were not correlated with corneal thickness of corneal curvature postoperatively. Both Tono-Pen 2 and X-Pert NCT could thus be considered accurate instruments for IOP screening after cataract surgery when compared to the Goldmann applanation tonometer.

Cataract↗
PubMed1993

[Clinical evaluation of betaxolol in ophthalmic suspension with or without preservative agent in patients with glaucoma or ocular hypertension].

A prospective, randomized, cross-over, double-blind trial was designed to compare the safety and intraocular pressure (IOP) lowering effect of betaxolol 0.25% ophthalmic suspension with and without preservative (benzalkonium chloride). Twenty-seven patients with primary open angle glaucoma or with ocular hypertension were assigned randomly to receive either the preserved or the unpreserved unit dose betaxolol suspension first, followed by the second medication after a 7-10 day washout period. Both test medications significantly reduced IOP from baseline (p < 0.01) twelve hours after dosing at each observation times. IOP was reduced from a mean of 26.1 mmHg at baseline to 21.6 mmHg (preserved formulation) and from a mean of 25.7 mmHg at baseline to 22.3 mmHg (unpreserved formulation) on day 7. There were no significant differences between treatments, nor was there any evidence of any order effect. Adverse events possibly associated with study drugs included transient headache following instillation in one patient on both preserved and unpreserved formulations. It is concluded from this study that inclusion of a preservative in the betaxolol suspension formulation has no effect on the IOP control afforded by betaxolol, and that both preserved and unpreserved suspensions were safe for use in treatment of glaucoma and ocular hypertension.

Adult↗
PubMed1993

[Experimental use of liposomes carrying an antimetabolite (mitoxantrone) in filtering surgery].

Fibroblast proliferation plays a prominent role in closure of conjunctival filtering blebs and extensive investigations are being carried out to optimize antiproliferative pharmacotherapy in the prevention of filtering bleb failure in glaucomatous eyes with a poor prognosis undergoing surgery. Intercalating agents such as doxorubicin or daunorubicin have been shown to decrease fibroblast proliferation in tissue cultures. A liposomal delivery system was developed in an attempt to obtain a sustained release effect and to minimize ocular side effects of mitoxantrone (Novantrone, MITX), an antineoplastic agent with intercalating properties. The objectives of this study were to demonstrate the entrapment stability of MITX in multilamellar vesicles (reaching about 60% and remaining at this level for 8-weeks storage) and to investigate its activity in vitro (cell cultures) and in vivo (sclerectomy ab externo in rabbits). We showed that entrapped MITX inhibited in a dose-dependent manner subconjunctival fibroblast proliferation (ID50: 0.03 micrograms/l at D3 in cultures) and prolonged the success of filtration surgery in rabbits (decrease of intraocular pressure of 8 mm Hg in treated eyes versus 1.8 mm Hg in control eyes; p < 0.01). These results indicate the potential of MITX-entrapped liposomes in the control of conjunctival scarring in filtering bleb surgery.

Animals↗
PubMed1993

[Chronic blepharoconjunctivitis during a treatment with acitretin (Soriatane)].

We report external ocular side effects after treatment with acitretin, a new synthetic vitamin A analogue and the main metabolite of etretinate. A patient treated with 20-25 mg/day of acitretin for psoriasis suffered from chronic blepharoconjunctivitis. Schirmer tests, tear lysozyme were normal while rose bengal and fluorescein staining disclosed epithelial punctate defects and tear break-up time was shortened. Meibomian glands of the lower lid were photographed with transillumination and appeared atrophic. Conjunctival cytology and biopsy showed snake-like chromatine appearance, keratinized epithelial cells and some lymphocytes infiltrates. Accessory salivary gland histological aspects were nonspecific. There was a clear relationship between restarting the acitretin therapy and recurrence of ocular symptoms. Acitretin, like other retinoids, may induce or exacerbate blepharoconjunctivitis in patients with psoriasis.

Acitretin↗
PubMed1991

Autoradiographic characterization and localization of vasoactive intestinal peptide binding sites in albino rat and rabbit eyes.

Localization and pharmacological properties of vasoactive intestinal peptide (VIP) binding sites were investigated in eyes from albino rabbits and rats using an in vitro autoradiographic method. [125I]VIP was used as ligand, and various unlabelled peptides were studied to test the specificity of binding. Autoradiograms were generated by apposing 20-microns-thick cryostat eye sections to [3H]Hyperfilm or autoradiographic emulsion and quantified by means of image analysis procedures. Specific binding represented about 85% of total binding. Kinetic studies showed that equilibrium was reached after a 120-min incubation at room temperature. Biochemical investigations demonstrated that [125I-]VIP bound to a population of sites with high affinity (Kd = 2.27 +/- 0.25 nM). Inhibition of [125I]VIP binding with VIP and related peptides indicated the following rank order of potency: VIP greater than Peptide histidine isoleucine greater than secretin greater than human growth hormone-releasing factor, glucagon, VIP1-14, VIP14-28. In both species, specific binding was found in conjunctiva, iris, ciliary processes, choroid and retina. Moderate grain densities of VIP binding sites were also present in the rat cornea. Quantitative analysis of the autoradiograms revealed that the highest densities of [125I]VIP binding sites were located in the iris and ciliary epithelia in rabbits and in the inner retina in rats. Our findings suggest that VIP may play an important role in several ocular functions, especially in aqueous humor dynamics and retinal neuromodulation.

Animals↗
PubMed1991

Localization and characterization of substance P binding sites in rat and rabbit eyes.

Specific and high-affinity binding sites for Substance P (SP) were found in eyes from albino rabbits and rats using an in vitro autoradiographic method with 125I-Bolton Hunter SP (BHSP). autoradiograms were generated by apposing 10-20 microns-thick cryostat eye sections to 3H-Hyperfilm or liquid emulsion and quantified by means of image-analysis procedures. Kinetic studies showed that equilibrium was reached after a 75-min incubation at room temperature. In rat retina, specific binding corresponding to approximately 90% of total binding, was reversible, of high affinity (dissociation constant [Kd], 0.13 +/- 0.02 nM). Half-time for dissociation of 125I-BHSP was about 15 min. Unlabeled SP and the two neurokinins (NK) A and B competed in a concentration-dependent manner for retinal sites labeled by 125I-BHSP with the following order of potencies: SP greater than NKA greater than NKB, in agreement with a pharmacologic profile of a SP receptor site. In both species, specific binding was found in the iris sphincter muscle, choroid, and retina. In rats, detectable amounts of SP-binding sites were also expressed in the corneal epithelium and iridial stroma. Quantitative analysis of the autoradiograms revealed that the highest densities of 125I-BHSP binding sites were localized in the iris sphincter muscle in rabbits and the inner retina in rats.

Animals↗
PubMed1991

[Atypical forms of optic neuritis of multiple sclerosis].

The authors report seven cases of optic neuritis in patients with a diagnosis of multiple sclerosis. All patients had severe bilateral eye disease with no or incomplete recovery. Clinical signs and symptoms of multiples sclerosis were observed in only some patients. IRM was remarkably sensitive for detecting cerebral lesions and confirming the diagnosis. In every case visual field abnormalities consisted of a diffuse defect of sensitivity with pericentral scotoma. The authors emphasize on two atypical forms, total acute neuropathy and chronic primary neuropathy.

Acute Disease↗
PubMed1990

Autoradiographic localization of D1 and D2 dopamine binding sites in the human retina.

The localization of dopamine binding sites was studied by in vitro autoradiography in the normal human retina using [125I]SCH 23982 for D1 receptor labelling and [125I]iodosulpride for D2 receptors. Results demonstrated that both types of binding sites were present in human retina. Binding of [125I]SCH 23982 to D1 dopamine receptor was blocked by 1 microM SKF 38393, SCH 23390 (D1 specific compounds) whereas bromocriptine and domperidone (D2 specific compounds) were inactive at the same concentration. On the contrary, binding of [125I]iodosulpride to D2 dopamine receptor was inhibited only by D2 drugs. Precise cellular distribution was given by microautoradiographic techniques and showed that binding sites were exclusively localized to the plexiform layers.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗