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Biomedical subjects

G Brasseur

Publications and source records attributed to G Brasseur.

At least 19 recordsLinked to original sources
PubMed2006

[Surgical management of nontraumatic corneal perforations: an 8-year retrospective study].

PURPOSE: Treatment of nontraumatic corneal perforation is a difficult task. The aim of our study was to retrospectively analyze predisposing conditions leading to perforation, surgical treatments, and visual outcomes. METHODS: Fifty-six patients were admitted in our department for a nontraumatic corneal perforation between 1997 and 2004. Mean patient age was 69 years (range, 16-95 years) and the mean follow-up was 20.5 months (range, 6-96 months). RESULTS: The diseases associated with perforations were neurotrophic ulcer in 24 cases (43%), peripheral immunologic ulcer in ten cases (18%), dry eye in six cases (11%), and infectious keratitis in seven cases (13%). All patients had specific adapted medical treatment before surgery. As a first procedure, we used cyanoacrylate glue in 14 cases (50% anatomic success), multilayer amniotic membrane transplantation in 23 cases (100% anatomic success), conjunctival flap in six cases, peripheral lamellar graft in three cases (33% anatomic success), emergency penetrating keratoplasty in 13 cases (31% anatomic success), and one patient's eye had to be eviscerated. Several surgical procedures were necessary in 16 cases (28%), nine patients needing total conjunctival flap at the end. We were able to achieve tectonic stability in 91% of eyes and 32% of patients recovered useful visual acuity between 20/400 and 20/50. CONCLUSION: Amniotic membrane transplantation is an effective method for managing corneal perforations and usually does not need a further reconstructive procedure. Visual outcome is poor when peripheral or central keratoplasty are needed. We recommend a conjunctival flap when descemetocele or perforation recurs despite previous surgical management.

Adolescent↗
PubMed2006

[Advantages of amniotic membrane transplantation in eye surface diseases].

Amniotic membrane transplantation is now a widely adopted technique in the field of eye surface diseases. Depending on the indication, the amniotic membrane can be used as either a graft or a patch. When used as a graft, the amniotic membrane serves as a substrate for regrowth of deficient epithelium; the aim is to integrate this membrane. The basal membrane reinforces the adhesion and differentiation of the corneal epithelial cells, facilitates their migration, and prevents their apoptosis. When used as a patch, the amniotic membrane is sutured epithelium-down so as to maximize the concentration of biological factors delivered by this membrane: the membrane covers the diseased cornea and acts as a biological bandage and analgesic. The best indications for amniotic membrane grafts are acute chemical burns and trophic corneal ulcers refractory to all medical treatment. When these ulcers are perforated or in the early stages of perforation, it is best to use multiple layers of amniotic membrane, restoring the thickness of the cornea. In cases of confirmed limbal deficiency, amniotic membrane grafts may be a useful complement to the necessary limbal stem cell grafts. In the future, amniotic membranes will provide an indispensable support for the expansion of cultured stem cells. Amniotic membrane grafts may also be used to reconstruct the conjunctiva following the exeresis of symblepharons or conjunctival tumors. However, the use of this technique is currently limited to diseases with little inflammation and no extensive fibrosis.

Amnion↗
PubMed2006

[Intraocular fluids analysis for etiologic diagnosis of presumed infectious uveitis].

PURPOSE: To study the etiologic distribution of patients with presumed infectious uveitis who underwent ocular fluid analysis. PATIENTS AND METHODS: We retrospectively analyzed vitreous and or aqueous humor samples of patients with presumed infectious uveitis, referred to the department of Ophthalmology of the University Hospital of Rouen, France, between January 1997 and June 2004. We excluded patients with postsurgical or endogenous endophthalmitis. We noted clinical features and intraocular sample analysis methods for each pathogen. RESULTS: The study included 42 patients, 24 men and 18 women, aged between 6 and 79 years (mean, 39.5 years). Uveitis was unilateral in 88% of cases and bilateral in 12%. Posterior uveitis was predominant (52%), followed by panuveitis (24%), anterior (14%), and intermediate uveitis (10%). Aqueous humor and vitreous analysis confirmed etiological diagnosis for 13 of 41 patients (31%) and three of six cases (50%), respectively. Inflammation was controlled or stabilized in all cases. The most pejorative visual outcome was observed for candidiasis and viral retinitis. Positivity of intraocular samples was variable, depending on the suspected pathogen, with results similar to those reported in other studies. DISCUSSION: Atypical features in potential infectious uveitis justify ocular paracentesis or vitrectomy, which are more efficient since molecular biological tools have become available. Sensitivity of aqueous humor analysis is high for posterior uveitis and suspicion of viral retinitis. New molecular variants applied to ocular samples will improve the etiological diagnosis of infectious uveitis, particularly for pathogens that are difficult to culture, such as fungi and bacteria.

Adolescent↗
PubMed2006

[Meningococcus endophthalmitis without meningitidis].

Meningococcus endophthalmitis is exceptional. We report a case of ocular damage following type C meningococcus septicemia with no meningitis. A 20-year-old man reported to the emergency unit for polyarthritis pain in various joints, associated with chills, nausea, and diarrhea without fever. Ophthalmological examination revealed uveitis. A few days later, endogenous endophthalmitis was suggested because of a worsening general condition and fever spells to 39 degrees C. A hemoculture sampled on the patient's admission 4 days earlier revealed Neisseria meningitidis positivity. Meningococcus septicemia with no meningitis was diagnosed. Before the introduction of antibiotics, meningococcus meningitis was unfortunately frequent and ocular septic embolism was not a rare occurrence. The diagnosis of meningococcemia was delayed in our patient because of the atypical symptomatology and ocular manifestations in the forefront. As with any endogenous endophthalmitis, prognosis is bleak and it should be raised whenever suspected uveitis does not react to standard treatment.

Adult↗
PubMed2005

Concentration of neuron-specific enolase and S100 protein in the subretinal fluid of rhegmatogenous retinal detachment.

BACKGROUND: Neuron-specific enolase and S100 protein are markers of neuronal lysis. To assess the neuronal suffering in rhegmatogenous retinal detachment we quantified neuron-specific enolase and S100 protein in the subretinal fluid. METHODS: The puncture was performed in the sclera with a Merseture 5/0 round needle, and the fluid was collected with a glass capillary tube. Twelve subretinal fluid samples were obtained from 12 eyes with rhegmatogenous retinal detachment undergoing retinal detachment surgery. Vitreous from ten eyes with macular hole or epimacular membrane served as negative control group, and vitreous collected during cornea procurement from ten deceased patients served as positive control group. RESULTS: The mean concentration of neuron-specific enolase (in nanogrammes per millilitre) was 602 in the subretinal fluid of rhegmatogenous retinal detachment, 10.2 in the serum of these patients, 2.9 in the vitreous of the negative control group, and 364 in the positive control group. The mean concentration of S100 protein (in nanogrammes per millilitre) was 104 in the subretinal fluid of rhegmatogenous retinal detachment, <0.1 in the serum of these patients and in the vitreous of the control negative group, and 11.18 in the positive control group. CONCLUSION: Neuron-specific enolase (NSE) and S100 are known to be good markers of brain stress and, thus, are good markers of retinal stress.

Adult↗
PubMed2005

[Macular hole evaluation with 10-MHz and 20-MHz ultrasonography and optical coherence tomography].

PURPOSE: To evaluate and compare the data provided by 10-MHz and 20-MHz ultrasonography and optical coherence tomography (OCT) in macular hole exploration. MATERIAL AND METHODS: Sixty patients with macular hole at different stages were included in the study from January 2002 to April 2003. All patients received three successive examinations: an echographic examination with a 10- and 20-MHz probe (Quantel Medical Cinescan) and an examination with optical coherence tomography (OCT) (Humphrey Zeiss). RESULTS: In stages I and II, the 10-MHz examination was not a useful tool; in certain cases the 20-MHz examination highlighted stage II macular holes. OCT was better than ultrasonography in all these cases: it clearly defined the outline of the hole and perifovea posterior vitreous detachment (PVD). In stage III, the 10-MHz examination only allowed the visualization of the high reflectivity of the prefoveal operculum; the 20-MHz examination could also measure the thickness of the macular neuroepithelium. OCT very precisely visualized the hole as well as the opercula and the detachment of the posterior hyaloid located in the macular area but still attached to the papilla. In stage IV, the 10-MHz examination confirmed total PVD. High-frequency ultrasound examination and OCT provided somewhat similar information. OCT provided the advantage of measuring the hole. DISCUSSION: It is possible now to use probes of frequencies higher than 10 MHz for the study of the posterior pole and the vitreomacular junction at the cost of a more reduced exploration area than that usually obtained with a 10-MHz probe and a lower reflectivity of the interfaces encountered. One is indeed very quickly limited by noise if the gain is increased. Usually, the standard gain with 20 MHz is close to 90 dB and beyond 100 dB, the images are uninterpretable because of noise. CONCLUSION: The 10-MHz ultrasonography is very useful for an overall assessment of the vitreous body, its mobility, and in searching for PVD. The 20-MHz examination gives very valuable information on the analysis of the vitreomacular junction, approaching the precision level provided by OCT. It demands a very rigorous examination protocol. OCT, however, remains better for the fine morphological study of this zone, unless opaque media studies are necessary to determine the maximum frequency usable to increase the space resolution of the lesions of the posterior pole. In this case, the combined ultrasonographic study using 10 and 20 MHz provides a valid diagnosis and a therapeutic approach to the posterior pole.

Humans↗
PubMed2005

[Infantile esotropia: comparison of surgery results when the intervention takes place before or after 30 months of age].

OBJECTIVE: Present and compare surgery results of children with congenital or infantile esotropia, who had surgery before or after 30 months of age, in the Rouen Department of Ophthalmology between 1996 and 2000. PATIENTS AND METHODS: A retrospective study included 37 patients, 23 females and 14 males, 19 in the first group who had surgery before 30 months at an average age of 24 months (15-30) and 18 in the second group who had surgery after 30 months at an average age of 56 months (38-81). Hypermetropia was found up to 2 diopters for 14 of 19 patients in the first group and 13 of 18 in the second. We noted the surgical procedure. We compared pre- and postoperative amblyopia as well as pre- and postoperative objective deviations at near and distance ranges. The exclusion criteria were follow-up for less than 3 months, esotropia emergence after 12 months of age, children aged more than 7 years at the first surgery, and children with central nervous system disorders. Finally, esthetic aspect, postoperative distance and near sensory results were evaluated. Success was defined by orthotropic position, esotropia less than 15 prism diopters, or consecutive exotropia less than 10 prism diopters. RESULTS: The mean follow-up after surgery was 30 months (3-56) for the first group and 28 months (3-67) for the second. Motor results were similar between the two groups: we found 10 out of 19 successes (esotropia (E(T)) less than 15 diopters (D) or exotropia (X(T)) less than 10 D) in the first group, and 15 out of 18 successes in the second group. There were 3 out of 19 failures (E(T) more than 20 D or X(T) more than 15 D) in the first group and 3 out of 18 in the second. Hypermetropia and preoperative deviation were not significantly different for good or bad motor results (p<0.05). A second-step surgery was performed for two children in the first group and three in the second group, and one of the three children of the second group had a third step. Sensory results were very similar with 6 of 19 cases achieving binocular union in the first group and 7 of 18 in the second one. Finally, one patient from each group presented amblyopia after surgery. CONCLUSION: In our study, as in the literature, infantile esotropia surgery can result in excellent motor alignment, while sensory results are not as good. It appears in our study that there is no significant advantage in performing surgery before 30 months for infantile esotropia. The follow-up of our patients may have been insufficient, and our definition of the semi-early surgery (before 30 months) was already too late in comparison with other studies (less than 24 months).

Age Factors↗
PubMed2005

[Optic neuropathy associated with primary antiphospholipid syndrome].

We describe a 45-year-old male patient with an atypical unilateral optic neuropathy who was diagnosed with primary antiphospholipid syndrome. The initially poor vision lasting several months completely recovered and long-term oral anticoagulation therapy prevented potential further systemic thrombotic complications.

Anticoagulants↗
PubMed2005

Advanced glycation end products can induce glial reaction and neuronal degeneration in retinal explants.

BACKGROUND/AIMS: Neuronal degeneration has been reported to occur in diabetic retinopathy before the onset of detectable microvascular abnormalities. To investigate whether advanced glycation end products (AGE) could be directly responsible for retinal neurodegeneration, retinal explants were incubated with glycated bovine serum albumin (BSA). METHODS: Retinal explants obtained from non-diabetic adult rats were incubated 4 days with or without 200 mug/ml glycated BSA. Neural apoptosis was quantified by terminal dUTP nick end labelling (TUNEL) binding and immunostaining with anti-cleaved caspase-3 antibody. Expression of glial fibrillary acidic protein (GFAP) was localised by immunofluorescence. RESULTS: TUNEL and cleaved caspase-3 positive cells increased significantly by 2.2-fold and 2.5-fold in retinal explants incubated in glycated BSA (p<0.05), respectively. The ganglion cell layer was the most sensitive retinal layer to the glycated BSA. Neuronal degeneration was confirmed by the increased GFAP labelling in Müller glial cells from retinal explants treated with glycated BSA. CONCLUSION: These results suggest that AGE could induce retinal neurodegeneration in the absence of blood perfusion. Cells in the ganglion cell layer appeared to be the most sensitive as in diabetic retinopathy and its animal models. AGE toxicity could therefore contribute to the early pathological mechanisms of diabetic retinopathy.

Animals↗
PubMed2004

Apparent redundancy of electron transfer pathways via bc(1) complexes and terminal oxidases in the extremophilic chemolithoautotrophic Acidithiobacillus ferrooxidans.

Acidithiobacillus ferrooxidans is an acidophilic chemolithoautotrophic bacterium that can grow in the presence of either the weak reductant Fe(2+), or reducing sulfur compounds that provide more energy for growth than Fe(2+). We have previously shown that the uphill electron transfer pathway between Fe(2+) and NAD(+) involved a bc(1) complex that functions only in the reverse direction [J. Bacteriol. 182, (2000) 3602]. In the present work, we demonstrate both the existence of a bc(1) complex functioning in the forward direction, expressed when the cells are grown on sulfur, and the presence of two terminal oxidases, a bd and a ba(3) type oxidase expressed more in sulfur than in iron-grown cells, besides the cytochrome aa(3) that was found to be expressed only in iron-grown cells. Sulfur-grown cells exhibit a branching point for electron flow at the level of the quinol pool leading on the one hand to a bd type oxidase, and on the other hand to a bc(1)-->ba(3) pathway. We have also demonstrated the presence in the genome of transcriptionally active genes potentially encoding the subunits of a bo(3) type oxidase. A scheme for the electron transfer chains has been established that shows the existence of multiple respiratory routes to a single electron acceptor O(2). Possible reasons for these apparently redundant pathways are discussed.

Acidithiobacillus↗
PubMed2004

[Anterior segment tumor imaging: advantages of ultrasound (10, 20 and 50 MHz) and optical coherence tomography].

PURPOSE: Detail the role of different imaging techniques for diagnosis of tumors of the iris. MATERIAL AND METHODS: Sixty-one tumors of the iris were explored using ultrasound at 10 and 20MHz (Cinescan, BVI Quantel Medical) and 50MHz (UBM, Paradigm) and optical coherence tomography (OCT) (Humphrey Zeiss). RESULTS: Ultrasound should be used at frequencies of 20MHz or greater to precisely characterize, localize and measure a lesion. Ultrasound biomicroscopy (UBM) is inadequate to measure large tumors (extending toward the back of the ciliary body), because of the transducer and the considerably lower image quality caused by the lesion. Ultrasound alone cannot characterize a solid lesion, and moreover cannot differentiate benign and malignant lesions. Clinical notions are also important in diagnosis and patient management. OCT recognizes whether a lesion is liquid or solid in certain cases. CONCLUSIONS: With a tumor that seems solid, a 50MHz examination must be done rapidly, and if the entire lesion is difficult to see, a 20MHz ultrasound should be used. With a protruding iris, high-frequency ultrasound and OCT differentiate a cystic lesion from a solid mass, but only BMU provides a precise measurement and regular surveillance capabilities.

Anterior Eye Segment↗
PubMed2004

[Vitrectomy for floaters].

PURPOSE: To clarify vitrectomy indications in the treatment of vitreous floaters. METHODS: This is a retrospective study of four patients, four eyes (age, 42-65 years), who underwent vitrectomy for the treatment of vitreous floaters. Two patients had a total posterior vitreous detachment. All patients were required to think about the intervention for several months before consenting. RESULTS: Preoperative visual acuity ranged from 20/40 to 30/30 and after the operation it ranged from 20/40 to 10/10. Minimum follow-up was 1 year. Visual acuity did not decrease after treatment in any patients. All patients expressed satisfaction with their postoperative visual function. DISCUSSION-CONCLUSION: Visual acuity measures do not always accurately reflect patients' visual discomfort. Vitrectomy has been known for many years. It can be proposed as a last resort after thorough retina examination, after patients have received adequate information and they are psychologically ready for the procedure.

Adult↗
PubMed2003

[The importance of flow cytometry and the cell proliferation index in choroidal melanoma].

PURPOSE: To evaluate the prognostic value of DNA ploidy and proliferative activity in metastasis occurrence after enucleation for choroidal melanomas. METHODS: This retrospective study investigated 14 patients (eight males, six females) using flow cytometry and immunohistochemistry with the Ki67 antibody. RESULTS: Two of the tumors were aneuploid, 12 were diploid. The proliferation index was between 0% and 16%. Two tumors progressed to metastatic disease; both were diploid and had a low proliferation index. They were mixed cell type. The median observation period was 3 years and 9 months. CONCLUSION: DNA content and proliferative activity are not correlated with metastasis occurrence. Sclera invasion is the best prognostic factor.

Aged↗
PubMed2003

[Intraocular pressure results of contact transscleral cyclophotocoagulation with Neodymium YAG laser for refractory glaucoma].

PURPOSE: To evaluate the effects of contact transscleral cyclophotocoagulation with neodymium YAG laser for refractory glaucoma. METHOD: This was a retrospective study with 36 patients (37 eyes) who were treated at the Rouen Hospital from February 1996 to February 2001. Patients had various types of glaucoma: glaucoma in pseudophakia (12), primary open-angle glaucoma (16), posttraumatic glaucoma (6), glaucoma associated with uveitis (4), neovascular glaucoma (3), and glaucoma after silicone oil (1). The Neodymium YAG laser (Alcon) was used for treatment. Energy was delivered in up 32 applications of 7-9 W for 0.7 seconds each. All patients except one 10-year-old child received retrobulbar anesthesia. Intraocular pressure was measured after 4 hours, 1 month, and 10 years. RESULTS: The mean preoperative intraocular pressure of 30.3 (+/-1.3) mmHg decreased to 19.4 (+/-2) mmHg at 1 month and to 22.2 (+/-2.4) mmHg at 1 year. Seven patients underwent a second treatment during the year, since the first one was insufficient. Treatment lowered the number of medications used to decrease intraocular pressure from a pretherapy mean of 2.7 mmHg to 1.8 mmHg at 1 month and 2.07 mmHg at 1 year. In three patients who were treated for a painful sightless eye, the treatment failed. DISCUSSION: Neodymium YAG laser necroses ciliary bodies. Treatment must be dosed to achieve the greatest efficacy without hypotonia, although hypotonia is rare, as is non-response to treatment. A few patients will be retreated during the year. The subgroup of sightless painful eyes had a high failure rate (75%), with half undergoing evisceration. We found no other differences according to the origins of refractory glaucoma. CONCLUSION: Midterm results of contact transscleral cyclophotocoagulation with Neodymium YAG laser are encouraging in the treatment of refractory glaucoma.

Adolescent↗
PubMed2002

Use of denaturing HPLC and automated sequencing to screen the VMD2 gene for mutations associated with Best's vitelliform macular dystrophy.

We identified three novel VMD2 mutations in patients with Best's macular dystrophy. DHPLC analysis of the 11 VMD2 exons revealed abnormal profiles in exon 8. Direct sequencing showed that these abnormal profiles were due to monoallelic transitions and transversions. We also found three polymorphic sequence changes that have been reported previously and annotated to an online database (http://www.uni-wuerzburg.de/humangenetics/vmd2.html).

Bestrophins↗
PubMed2002

Analysing the various obstacles to cornea postmortem procurement.

AIMS: In many countries the number of corneal donations is far too low to graft all patients on waiting lists within reasonable time. The aim of this study was to define specifically what practical changes are to be implemented to fully meet corneal graft demand. METHODS: The list of potential donors drawn by the coordination team from 1 January to 31 December 1999 was compared with that of all patients who had died during the same period. In each identified record, the parameters which permitted or precluded effective collection of cornea specimens were analysed, and the reasons why other records were not identified were investigated. RESULTS: Among the 1112 patients who died in 1999, coordinating nurses were able to identify 451 records (40.5 %) including 329 patients aged between 18 and 85 years (29.5%). After excluding 184 patients (55.9 %) who presented with medical contraindications, the coordinating nurses were able to meet the relatives of only 55 out of 145 patients (38%) and obtained their agreement in 39 cases (71% approval rate). Therefore, relatives' refusal was the cause for the absence of collection in only 5.5% of cases (16/290). The number of corneas procured amounted to 11.8% of identified records and 3.5% of all deceased patients. CONCLUSION: French law and regulations regarding tissue collection are based on consent presumption but it requires that verifications be made with the relatives to ensure that potential donors were not, before their death, opposed to such tissue procurement. That provision implies a high degree of organisation on the part of coordinating teams. It was demonstrated that donation shortage is no longer the result of relatives' refusal but rather because of logistical difficulties (potential donors not identified and problems in reaching relatives). It appears necessary therefore to strengthen coordinating teams with sufficient staff levels for wider donor identification. Those teams should also find ways to keep closer contact with relatives, so as to meet the maximum transparency targets required by public opinion and regulations and to graft all patients awaiting corneal transplantation.

Adolescent↗
PubMed2001

Analysis of suppressor mutation reveals long distance interactions in the bc(1) complex of Saccharomyces cerevisiae.

Four totally conserved glycines are involved in the packing of the two cytochrome b hemes, b(L) and b(H), of the bc(1) complex. The conserved glycine 131 is involved in the packing of heme b(L) and is separated by only 3 A from this heme in the bc(1) complex structure. The cytochrome b respiratory deficient mutant G131S is affected in the assembly of the bc(1) complex. An intragenic suppressor mutation was obtained at position 260, in the ef loop, where a glycine was replaced by an alanine. This respiratory competent revertant exhibited a low bc(1) complex activity and was affected in the electron transfer at the Q(P) site. The k(min) for the substrate DBH(2) was diminished by an order of magnitude and EPR spectra showed a partially empty Q(P) site. However, the binding of the Q(P) site inhibitors stigmatellin and myxothiazol remained unchanged in the suppressor strain. Optical spectroscopy revealed that heme b(L) is red shifted by 0.8 nm and that the E(m) of heme b(L) was slightly increased (+20 mV) in the revertant strain as compared to wild type strain values. Addition of a methyl group at position 260 is thus sufficient to allow the assembly of the bc(1) complex and the insertion of heme b(L) despite the presence of the serine at position 131. Surprisingly, reversion at position 260 was located 13 A away from the original mutation and revealed a long distance interaction in the yeast bc(1) complex.

Binding Sites↗