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Biomedical subjects

C Baudouin

Publications and source records attributed to C Baudouin.

159 records · Page 9Linked to original sources
PubMed1989

Pharmacokinetic and autoradiographic studies of basic fibroblast growth factor on de-epithelialized and intact rabbit eye.

In a previous work, we showed and compared the wound healing properties of aFGF and bFGF topically administered on totally de-epithelialized rabbit corneas. Pharmacokinetic and autoradiographic studies were then performed to investigate the sites of accumulation of bFGF in ocular structures, both on de-epithelialized and intact rabbit eyes. After one single instillation of 125I-bFGF, all the ocular structures were dissected and the measurement of the radioactivity allowed to establish kinetic curves. The results showed a very important and early fixation of bFGF on denuded cornea (10 minutes) and a posterior distribution of the drug between 10 and 30 minutes. A second accumulation of bFGF in the anterior segment appeared 8 hours after application and then decreased till the 48th hour. These findings were confirmed by the macroautoradiographies and the microautoradiographies pointed out the fixation of bFGF not only at the location of the Bowman membrane, but also on the corneal endothelium. These experiments also demonstrated the systemic diffusion of bFGF into the untreated controlateral eye. The integrity of bFGF in the cornea and other structures was then confirmed by SDS PAGE followed by autoradiography. In the intact eye, bFGF was shown to penetrate in extremely low amounts, illustrating the major role of the corneal barrier. For a therapeutic use bFGF may be recommended as an efficient wound healing agent for epithelial but also endothelial defects. Its eventual unwanted side effects must be kept in mind to perfect an efficient low dose and short term clinical treatment.

Animals↗
PubMed1988

Immunohistopathologic findings in proliferative diabetic retinopathy.

We performed immunopathologic studies on pars plana specimens obtained by biopsy in patients with diabetes mellitus type I or II and by autopsy in diabetic patients and normal subjects. Frozen sections were treated with several antisera, including anti-IgG, complement components, and major histocompatibility complex antigens, as well as anti-factor VIII to detect vascular structures. The results showed IgG in a linear pattern at the basal pole of pigment epithelial cells and complement deposits of C3c, C3d, and C4 at the same location and in the stroma. HLA-DR expression was found at the level of the pigmented cells. These data suggest that some autoimmune processes may be involved in proliferative diabetic retinopathy at the level of the pigment epithelium, but it is unknown whether they are an epiphenomenon of neovascularization or if they play a role in its initiation.

Adult↗
PubMed1988

HLA DR and DQ distribution in normal human ocular structures.

HLA DR and DQ distribution was investigated in normal human ocular tissues, together with class I antigens and immunocompetent cell subsets, by immunofluorescence and immunoperoxidase procedures. In the anterior segment, our findings, consistent with those of previous reports, showed the wide distribution of class I antigens, specially in the corneal epithelium, while class II antigens were restricted to very rare cells scattered in the conjunctiva, the peripheral cornea and the stroma of the ciliary processes. Some non pigmented epithelial cells of the ciliary processes were HLA DR and DQ positive. In the posterior segment, class I antigens were abundantly represented in the choroid and the retinal layers. Few HLA DR and DQ positive cells were seen in the choroid, similar to those found in the anterior segment. Normal RPE did not react with any monoclonal antibody, but numerous cells located in the retina were strongly HLA DR and DQ positive, all around the blood vessels, and not at the sites of endothelial cells. The characterization of those cells, which could be hypothetized as pericytes needs further studies but suggests close relationships between neuroretina and the immune system. This study may provide insight in the implication of the immune system in many poorly understood ocular diseases.

Adult↗
PubMed1987

Effects of aFGF and bFGF on wound healing in rabbit corneas.

After the debridement of the entire corneal epithelium of the rabbit eye, epithelial cells of conjunctival origin cover the denuded corneal surface. Under such experimental conditions, the rate of wound healing is considerably delayed and total regeneration is completed within 15 to 20 days, allowing evaluation of various drugs, such as the Fibroblast Growth Factor. Both acidic and basic FGF were administered topically on totally de-epithelialized rabbit eye, at three different concentrations of 1.5 and 10 Stimulation Units/50 microliters, 3 times per day. A dose-response effect was observed and in each case, acidic FGF was found to be much more potent than bFGF in increasing the rate of wound healing of the cornea. These results are correlated with a new purification procedure, avoiding acid treatment of the tissue extract. The systemic diffusion of FGF allows the contralateral eye cells to be also stimulated for mitosis and migration and to heal faster than the control eyes.

Animals↗
PubMed1987

[Isolation of LAV/HTLV III from tears of patients with the ARC syndrome].

Isolation of Human Immunodeficiency Virus (HIV) was attempted from the tears of seven patients with ARC. For two of these patients the fluid from cell cultures showed significant reverse transcriptase activity. One strain was maintained on C.E.M. (T lymphocytes cell line). Indirect fixed cell immuno fluorescence and Western Blot tests have shown this strain to be a HIV. This result confirms other already published data. Although there is no evidence of transmission through tears, the presence of the virus should not be forgotten.

AIDS-Related Complex↗
PubMedDate not supplied

Proton MR spectroscopy in herpes simplex encephalitis: assessment of neuronal loss.

We present here the case of an 11-year-old boy with herpes simplex encephalitis diagnosed on the basis of clinical features, serology, and response to acyclovir, who relapsed after 3 weeks of therapy. In vivo proton magnetic resonance spectroscopy (1H MRS) of the brain, at 8 and 16 weeks after the onset of symptoms, showed abnormalities, most prominently a reduction in the N-acetylaspartate/choline ratio. The role of 1H MRS in assessing disease activity is discussed.

Aspartic Acid↗
PubMedDate not supplied

Comparison of the effects of preserved and unpreserved formulations of timolol on the ocular surface of albino rabbits.

Thirty-six albino rabbits, randomly divided into six groups, were used to study their ocular tolerance to (a) 0.25 and 0.50% Timoptol preserved with 0.01% benzalkonium chloride, (b) 0.25 and 0.50% Timoptol-LP, a gel-forming solution preserved with 0. 012% benzododecinium bromide, and (c) 0.25 and 0.50% Timabak unpreserved in the ABAK eyedrops dispenser. All eyedrops were applied in the right eye for 60 days. A clinical follow-up with slitlamp examination and break-up time evaluation was performed for 2 months. At the end of the experimentation, the animals were sacrificed and their eyes enucleated for histological analyses of the conjunctiva and cornea. There was no significant difference in the clinical examination between each group, except for the break-up time evaluation between Timoptol and Timabak at each concentration which was better with the unpreserved timolol. Histological results showed a significant difference in the corneal stroma edema between preserved and unpreserved timolol. This study confirms that using unpreserved timolol may be beneficial for the long-term treatment of glaucomatous patients as it increases tear film stability and decreases epithelial permeability and stromal aggression of the cornea.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

The triple classification of dry eye for practical clinical use.

PURPOSE: "Dry Eye is a condition produced by the inadequate interrelation between lacrimal film and ocular surface epithelium, and is caused by quantitative and qualitative deficits in one or both of them. It can be produced by one or combined etiologic causes, affecting one or several of the secretions of the glands serving the ocular surface, and producing secondary manifestations of different grades of severity". Clinicians need a practical classification to face diagnosis, prognosis and treatment. Dry eyes have many etiologies and pathogenesis, different affectation of the various dacryoglands and ocular surface epithelium, and diverse grades of severity. The specialists in xero-dacryology must know these three parameters to evaluate any case of dry eye, and to establish an adequate treatment. METHODS: To facilitate this, an open session in the 8th congress of the International Society of Dacryology and Dry Eye (Madrid, April, 2005) proposed modifying the Triple Classification of dry eye approved in the XIV congress of the European Society of Ophthalmology (Madrid, June, 2003). There was consensus of all conclusions. CONCLUSIONS: The following classification has been established: First, a classification of the etio-pathogenesis, distributed in ten groups: age-related, hormonal, pharmacologic, immunopathic, hyponutritional, dysgenic, infectious/inflammatory, traumatic, neurologic and tantalic. Second, a classification of the affected glands and tissues, which under the acronym of ALMEN includes the Aqueo-serousdeficient, Lipodeficient, Mucindeficient and Epitheliopatic dry eyes, and the Non dacryological affected exocrine glands (saliva, nasal secretion, tracheo-pharyngeal secretion, etc). And thirdly, a classification of severity, in three grades: Grade 1 or mild (symptoms without slitlamp signs), grade 2 or moderate (symptoms with reversible signs), and grade 3 or severe (symptoms with permanent signs).

Aging↗
PubMedDate not supplied

[Immunohistologic study of the epiretinal membranes in proliferative diabetic retinopathy and retinal detachment with vitreo-retinal proliferation].

An immunohistological study was performed in specimens of epiretinal membranes obtained during surgery in patients with proliferative diabetic retinopathy or retinal detachment with proliferative vitreoretinopathy. Using immunostaining procedures, these membranes were found to contain great amounts of immunoglobulins and complement, as well as a strong expression of class II antigens. These results confirm the involvement of auto-immune phenomena in intra-ocular proliferative diseases and the close relationship between the immune system and peptide growth factors.

Cell Division↗
PubMedDate not supplied

[Immunopathologic study of retinal detachment with vitreo-retinal proliferation].

Immunopathological studies were performed on biopsies or autopsies of pars plana samples from patients with retinal detachment, with or without vitreo-retinal proliferation. Immunoglobulins and complement deposits have been found in vitreo retinal proliferation, together with a deviant expression of HLA-DR and DQ antigens by pigmented epithelial cells of the ciliary body. Gamma interferon is able to induce this expression in vitro, and the inducing effect of this lymphokine and other mediators has been tested on pigment epithelium cultures. Cultured pigment epithelial cells expressed HLA-DR and DQ antigens after being stimulated by very low doses of gamma interferon. The precise target of this immune reaction is still impossible to determine, but its consequences could be the release of growth factors as FGF, which has been found at very high levels in pigmented and non pigmented cells of pars plana and ciliary processes. Our work asserts the existence of auto-immune phenomena in retinal detachment with vitreo-retinal proliferation as well as in proliferative diabetic retinopathy, their exact involvement remaining to determine.

HLA-DQ Antigens↗