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Biomedical subjects

G Renard

Publications and source records attributed to G Renard.

At least 37 records · Page 2Linked to original sources

Effect of sulfated GAGs on the expression and activation of MMP-2 and MMP-9 in corneal and dermal explant cultures.

It has been shown previously that hyaluronan (HA) added to fibroblast and keratocyte cell cultures or corneal explant cultures produces an up-regulation of MMP-2 and MMP-9 expression and activation. Here, we examine the effect of sulfated GAG-s, chondroitin 4 and 6 sulfate (CS4, CS6), dermatan sulfate (DS), keratan sulfate (KS) and heparan sulfate (HS) on MMP-2 and 9 expression and activation under the same culture conditions. It appears that CS4 has only minor effects, KS inhibits MMP-2 activation and CS6, DS and HS increase MMP-2 activation in corneal explant cultures. For skin explant cultures, DS, KS and HS strongly increase MMP-9 activation, whereas KS inhibits and DS increases MMP-2 activation. All these effects can be strongly inhibited by the addition of an antibody to CD44, except CS6 and DS. Activation by these two GAGs was only slightly affected, supporting the contention that the effects of HA, CS4, KS and HS are mediated by one of the isoforms of this CD44 receptor. The physio-pathological significance of these results is discussed for cornea and skin ageing, because of the divergent evolution with in vitro ageing of the relative proportions of GAGs synthesised by these two cell types.

Cells, Cultured↗

[Multilocular eyelid hidrocystoma: an anatomical and clinical observation].

A cystic cutaneous mass was observed on the lateral canthus of the left eyelid in a 25-year-old woman, 2 years after being operated on for a lesion that had existed in the same area several years before, but the patient could not identify its nature. The present mass appeared as a well-circumscribed bluish cystic lesion. A surgical resection was performed; pathological analysis disclosed a cystic sweat tumor composed of several contiguous cysts. One year of follow-up has revealed no complications.

Adult↗

[Inflammatory pseudotumor of the caruncle].

A 6-year-old girl exhibited a recent caruncular tumor which was increasing in size. It was removed after a CT scan had showed a both medial and superficial mass. Fortunately, histological tests only found inflammatory cells attesting that the mass was due to an inflammation of this area. Inflammation is one of the different processes that may increase the size of the caruncle, but sometimes, only histopathology can provide conclusive evidence.

Child↗

[Hypertrophic eyelid conjunctival scar. A tarsal keloid].

The clinicopathologic case of a 53-year-old female patient with an abnormal tumor growing on the mucous part of the superior right eyelid is reported. The patient was operated on for ten years ago and a whitish mass slowly developed on the conjunctival face of the eyelid disturbing the use of corneal lenses. It was hard, painless and had the shape of a flat mushroom. The removal was performed under local anesthesia and allowed us to resect a hard and fibrous lesion. Histopathology showed that the lesion was made of a fibrous tissue organized like a hypertrophic scar. Surgical treatment of chalazion is frequent and rarely gives rise to abnormal scarring.

Cicatrix↗

[Why are aphakic anterior chamber intraocular lenses still implanted? Five-year incidence and implantation circumstances at the Hôtel-Dieu in Paris].

PURPOSE: To report incidence and circumstances of aphakic anterior chamber intraocular lens implantation. METHODS: Retrospective study of medical charts of anterior chamber intraocular lens implantation in the Ophthalmology Department, Hôtel Dieu, Paris, from 1996 to 2000, investigating the number of anterior intraocular lenses (ACIOL) implanted, circumstances, and incidence during cataract extraction. RESULTS: One hundred and forty-three ACIOLs (139 patients, 60 men, 79 women) were implanted. The mean age was 75.98+/-10.6 years [range, 35-96 years]. All ACIOLs were of open-loop design: open C-loop or Kelman lens. Four circumstances leading to ACIOL implantation were reported: extracapsular cataract extraction with intraoperative complications (94 cases), intracapsular cataract extraction (13 cases), secondary implantation (20 cases), and penetrating keratoplasty with ACIOL (9 cases). Since 1996, the number of ACIOLs implanted each year has decreased (p<0.01): 1.09% of cataract extractions performed in 1996 were implanted with ACIOLs and 0.43% in 2000. At the end of the 5-year period, 12,580 cataract extractions had been performed in our department, with a mean incidence of ACIOL implantation at 0.85%. CONCLUSION: ACIOLs continue to be implanted in some cases in the absence of capsular support. Because of endothelial complications, they must be reserved for elderly patients. Endothelial surveillance using specular microscopy remains indispensable.

Adult↗

[Corneal graft rejection and corticoid iontophoresis: 3 case reports].

This is the first report of three cases of severe acute corneal graft rejection, treated by transscleral methylprednisolone (Solumédrol) iontophoresis. The efficacy of the treatment was evaluated by corneal transparency, visual acuity and corneal inflammation parameters. The patient was treated with Solumédrol iontophoresis once a day for 3 days with a topical corticotherapy reduced to three drops of dexamethasone per day. Iontophoresis was performed, under topical anesthesia, and lasted 3 minutes with a 1.5-mA current. The subjective and objective tolerance of iontophoresis was good. No side-effect was observed. Corneal transparency and visual acuity improved rapidly after the second iontophoresis procedure. These observations show that Solumédrol iontophoresis might be an alternative to pulse therapy in the treatment of corneal graft rejection. Further comparative studies are necessary to confirm these preliminary observations.

Adult↗

[Conjunctival semi-lunar fold nevus of presumed late onset].

Conjunctival nevi are lesions observed commonly occasionnally and can be found later in a life. Such a lesion was observed on the conjunctival semilunar fold in a 76-year-old female patient. It was oval in shape, pigmented, and was mainly visible when the affected eye was in abduction. As no accurate anterior clinical history was available, surgical resection was performed. Hitopathological study disclosed a subepithelial nevus, which was completely resected. Regular follow-up was recommended, as is usual after surgical resection of a conjunctival pigmented tumor.

Aged↗

[Pseudotumoral eyelid inflammation. Apropos of an anatomo-clinical case].

A clinicopathological case of a 76-year-old male patient with a chronic inflammatory change of the inferior left eyelid is reported. The inflammation appeared as a reddish area of the inner part of the eyelid, without sharp limits, but with loss of lashes. Numerous local treatments did not to cure this condition. As some true eyelid tumors may mimic an inflammation during growth and, for example, sebaceous carcinoma may clinically present as chronic unilateral blepharitis, a surgical excisional biopsy was performed on this left eyelid. Its histopathological study showed a granulomatous inflammation, which was typical of a simple chalazion. This case clearly illustrates that the chalazion may not always appear as a limited nodular inflammation of the eyelid, but may have a more diffuse clinical presentation.

Aged↗

[Corneal edema in pseudophakia. A case report].

Pseudophakic bullous keratopathy is one of the most common complications of intraocular lenses, which explains the high rate of this condition in series of patients experiencing corneal grafts. It is caused by irreversible damage to the endothelial layer of the implanted eye involving the artificial lens, and occurs either during cataract extraction or after the operation. Intraoperative endothelial protection and the choice of an appropriate lens may contribute to decreasing this secondary disease, which can have severe consequences for many patients whose corneal graft may not restore their visual potential as well as expected. We report a clinicopathological case of a 59-year-old male, previously operated on for cataract in both eyes with an anterior chamber lens. A bilateral corneal edema occurred a few years after the operation, with a bilateral decrease in vision as a consequence. A corneal graft was performed in 2000 on the left eye in order to improve the patient's visual autonomy. The best treatment of this condition remains prevention, avoiding the use of this type of intraocular lens, whose main complication is corneal edema.

Cataract Extraction↗

[Conjunctival pyogenic granuloma in a patient with chalazions].

A 28-year-old male patient had a chalazion on his left eyelid. Increased discomfort led to the discovery of a conjunctival mass under the inner part of his upper eyelid. On clinical examination, a small reddish mass on the palpebral conjunctiva of the upper left eyelid was only visible on the underside of the lid; the mass was diffusely reddish. Additionally, a chalazion was present in the middle of the lower left eyelid. As this condition was a source of discomfort to the patient, the mass was surgically resected. The histological study found a typical pyogenic granuloma, a possible complication in the course of a chalazion.

Adult↗

Modulation of cell-phenotype during in vitro aging. Glycosaminoglycan biosynthesis by skin fibroblasts and corneal keratocytes.

The aim of this study was to compare keratocyte and fibroblast phenotypes during in vitro aging by comparing their biosynthesis of glycosaminoglycans using explant and cell cultures. Human skin and corneal explant cultures were realised with Dulbecco Modified Eagle's medium containing 3H glucosamine. Sequential cell cultures were studied at different passages for GAGs biosynthesis by 3H glucosamine incorporation followed by selective degradation with specific hydrolases. Radioactivity was determined and each GAG fraction evaluated. KS and DS are the major components synthesised by corneal explant culture. During in vitro aging, keratocytes synthesised 41% less KS between passages 4-9 with a decrease by 26% of the proportion of DS observed in the same conditions. In skin explant cultures, as expected the major components are CS and hyaluronan (HA). In the first cell passage studied compared with skin organ cultures we could notice a strong decrease of the proportions of DS and KS compensated by an increase of the proportion of HA. During the successive passages of fibroblasts, the proportions of DS and HS decreased (-30 and -62%, respectively) and those of KS increased (+90%). These results indicate that there remain measurable differences between keratocyte and fibroblast phenotypes as far as GAG-synthesis is concerned all though the successive passages, starting from explant cultures and up to the limits of in vitro cell passages.

Cells, Cultured↗

[Basal cell carcinoma associated with a squamous cell papilloma at the inner part of the eyelid].

There are numerous variants of cutaneous tumors involving the eyelids. Tumors of a different nature may at times be observed simultaneously in the same area of the eyelid. A clinicopathologic case of a 36-year-old male patient with 2 different cutaneous tumors at the nasal part of the left eyelid is reported. One was a nodular tumor on the inner canthus with a pearly appearance; the other had a papillomatous pattern. After surgical removal, the histopathological study of the tumors disclosed a typical basal cell carcinoma and a squamous cell papilloma. Both tumors can be commonly observed on the eyelids and surgical excision cured the patient.

Adult↗

[Vitrectomy without scleral buckle versus ab-externo approach for pseudophakic retinal detachment: comparative retrospective study].

PURPOSE: Retinal detachment (RD) is a major complication of cataract surgery, which can be treated by either primary vitrectomy without indentation or the scleral buckling procedure. The aim of this study is to compare the results of these two techniques for the treatment of pseudophakic RD. PATIENTS AND METHODS: The charts of 40 patients (40 eyes) treated with scleral buckling for a primary pseudophakic RD were retrospectively studied and compared to the charts of 32 patients (32 eyes) treated with primary vitrectomy without scleral buckle during the same period by the same surgeons. To obtain comparable samples, patients with giant retinal tears, vitreous hemorrhage, and severe preoperative proliferative vitreoretinopathy (PVR) were not included. Minimal follow-up was 6 months. RESULTS: The primary success rate was 84% in the vitrectomy group and 82.5% in the ab-externo group. Final anatomical success was observed in 100% of cases in the vitrectomy group and in 95% of cases in the ab-externo group. Final visual acuity was 0.5 or better in 44% of cases in the vitrectomy group and 37.5% in the ab-externo group. The duration of the surgery was significantly lower in the ab-externo group, whereas the hospital stay tended to be lower in the vitrectomy group. In the vitrectomy group, postoperative PVR developed in 3 eyes and new or undetected breaks were responsible for failure of the initial procedure in 2 eyes. CONCLUSION: Primary vitrectomy appears to be as effective as scleral buckling procedures for the treatment of pseudophakic RD.

Aged↗

[Eyelid neurofibroma affecting a young woman].

A 43-year-old female patient had an amelanotic single tumor thickening the upper right eyelid and observed since early childhood. Clinically, it appeared as a firm mass, without sharp margins, giving a thickened appearance to the superior eyelid. The ophthalmic clinical examination was normal but some subcutaneous nodules attested to the diffusion of the disease recognized as a limited form of neurofibromatosis 1. Although well tolerated, it gave rise to a cosmetic disturbance and the patient was willing to undergo an excision. A complete surgical excision was performed on the lesions and the pathological study disclosed a typical neurofibroma. Regular observation of the different cutaneous nodules was recommended.

Adult↗

[Eyelid precancerous keratosis].

A 25-year-old-male patient had one keratinized tumor on the inferior right eyelid, first observed 5 months before. Its size had been increasing for the last three weeks. The visual function was normal. Clinical examination disclosed a papillomatous lesion on the cutaneous middle part of the eyelid. A surgical excision was performed under local anesthesia. The histopathological study found a papillomatous epidermal proliferation with both structural and cytological atypias, concluding with a precancerous keratosis of the eyelid.

Adult↗

[Seborrheic keratosis of the eyelid in a young woman].

A 46-year-old female patient had a tumor of the free margin area of the superior right eyelid, appearing as the fourth recurrence of a primary lesion, occurring 24 years before. The lesion was covered with a thick layer of keratin, giving it a grayish and black color. Excision was performed without involving the free margin. Histopathology disclosed that the tumor was a seborrheic keratosis, which was not completely removed. As the lesion was benign, no further surgery was performed but regular examination was recommended to the patient.

Eyelid Diseases↗

[Protection of cornea against proteolytic damage. Experimental study of procyanidolic oligomers (PCO) on bovine cornea].

AIM OF THE STUDY: The purpose of this work was the development of an antiprotease treatment for the cornea and later for other ocular tissues. Indeed, many proteases participate in various ocular pathologies and no really effective treatments are currently available. METHODS: We worked on bovine corneas in organ cultures, incubated in the presence and absence of bacterial collagenase. We used procyanidolic oligomers from grape seeds (PCO) as the antiproteolytic agent, added to the cultures in two different concentrations. RESULTS: The corneas incubated in the presence of collagenase were quickly attacked and their degradation was practically complete after 24 hours. With the low concentration used (0.066 mg/ml), proteolysis was only slightly inhibited. With the higher concentration of PCO (1 mg/ml), the collagenolysis was completely prevented and the corneas were completely preserved. CONCLUSION: These results show that the protective effect of the PCO against proteolytic attack, demonstrated previously on other tissues, proved to be effective also for the cornea in vitro. An adequate method of administration in clinical practice must now be developed in order to obtain an effective clinical antiproteolytic treatment.

Animals↗