Establishment of a reliable laser-Induced Choroidal Neovascularization Animal Model

Purpose: Pathologic choroidal neovascularizations (CNV) are implicated in the wet form of age-related macular degeneration (ARMD). Abnormal vessel growth is also observed in disease when hypoxia and/or inflammation occur. Our goal is to establish a standard protocol of laser-induced CNV in mice that have different levels of pigmentation to identify the most reliable animal model.Methods: CNV was induced by 4 burns around the optic disk, using a green argon laser (100μm diameter spot size; 0,05 sec. duration) in C57/Bl6, DBA/1 and Balb/c to ascertain the efficacy of the method in function of retina pigmentation. Five different intensities were tested and Bruch's membrane disruption was identified by the appearance of a bubble at the site of photocoagulation. Fluorescein angiographies (FA) were undertaken 14 days post lesion and CNV area was quantified by immunohistochemistry on cryosections.Results: CNV retina area was related to spot intensity after laser injury. While 180mW and 200mW do not induce reliable CNV (respectively 27.85±0.35% and 29±1.67% of the retina surface), 260mW is required to induce 51,07±8.52% of CNV in C57/Bl6 mice. For the DBA/1 strain, less pigmented, 200mW was sufficient to induce 49.35±3.9% of CNV, indicating that lower intensity are required to induce CNV. Furthermore, an intensity of 180mW induced greater CNV (35.55±6.01%) than in C57/Bl6 mice. Nevertheless, laser did not induce reproducible 50% CNV in Balb/c albino mice for all intensities tested. Isolectin-B4 and GFAP stainings revealed neovessel formation and photoreceptor (PR) degeneration at the impact site. The presence of glia was observed throughout all the retinal layers and angiograms showed fluorescein leakage in pigmented mice.Conclusions: The establishment of a standard protocol to induce CNV and subsequent PR degeneration is of prime importance for the use of the laser-induced CNV model and will allow to evaluate the therapeutic potency of agents to prevent CNV and retinal degeneration.

Lésion du fond d'oeil séquellaire d'un traumatisme obstétrical: à propos d'un cas [Retinal lesion due to an obstetrical traumatism: a case report].

The authors report a case of unilateral, stable, localized, and well-circumscribed choriocapillaris atrophy associated with retinal pigment epithelium dispersion and atrophy. The anterior segment was normal. Facial examination revealed a homolateral malar hypoplasia. The other eye was normal. The electrophysiologic study did not confirm pigmentary degeneration of the retina. The patient's history included a difficult delivery using obstetrical forceps. The authors review the main ocular lesions secondary to birth trauma. In this case, they favored a traumatic chorioretinal lesion secondary to an obstetrical traumatism. In this context, progressive facial hemiatrophy is the main differential diagnosis.

Le multiple evanescent white dot syndrome: une prédisposition génétique [Multiple evanescent white dot syndrome: a genetic predisposition?]

BACKGROUND: Multiple evanescent white dot syndrome (MEWDS) is a benign acquired isolated chorioretinal disorder. Symptoms include photopsia, visual blur and scotomas. Ocular examination reveals multiple white dots at the level of the deep retina. A parainfectious disorder was suggested but the exact mechanism of MEWDS is still unknown. Postulating that MEWDS might be an antigen driven inflammatory reaction, we analyzed HLA subtypes in patients with MEWDS. PATIENTS AND METHODS: Sixteen patients were diagnosed with MEWDS in Lausanne from 1985 to 1994. Blood was withdrawn in 9/16 patients. HLA-A, -B and -DR were sought. RESULTS: HLA-B51 was detected in 4/9 patients (44.4%). Other HLA subtypes were detected sporadically. CONCLUSIONS: The frequency of HLA-B51 haplotype was found to be 3.7 times more elevated than in a normal control caucasian group. This suggests the possibility that MEWDS might be a genetically determined disorder as it is the case for other ocular diseases like Birdshot chorioretinopathy (HLA-A29), Harada's disease (HLA-DRMT3), acute anterior uveitis (HLA-B27) or Behçet's disease (HLA-B51). We have no explanation for the presence of HLA-B51 in both Behçet's disease and MEWDS. The association of HLA-B51 and MEWDS needs confirmation by further testing.

Temozolomide: a milestone in neuro-oncology and beyond?

Temozolomide (Temodal, Temodar), an imidazol derivative, is a second-generation alkylating agent. The orally available prodrug with the capacity of crossing the blood-brain barrier received accelerated US FDA approval in 1999. Three pivotal Phase II trials showed modest activity in the treatment of recurrent anaplastic astrocytoma glioblastoma. In 2005, the FDA and the European Agency for the Evaluation of Medicinal Products approved temozolomide for use in newly diagnosed glioblastoma, in conjunction with radiotherapy, based on an European Organisation for Research and Treatment of Cancer/National Cancer Institute of Canada Phase III trial. The adverse events associated with temozolomide are mild-to-moderate and generally predictable; the most serious are noncumulative and reversible myelosuppression and, in particular, thrombocytopenia, which occurs in less than 5% of patients. Continuous temozolomide administration is associated with profound CD4-selective lymphocytopenia. Molecular studies have suggested that the benefit of temozolomide chemotherapy is restricted to patients whose tumors have a methylated methylguanine methyltransferase gene promotor and are thus unable to repair some of the chemotherapy-induced DNA damage. Temozolomide is under investigation for other disease entities, in particular lower-grade glioma, brain metastases and melanoma.

An ultra performance liquid chromatography-tandem MS assay for tamoxifen metabolites profiling in plasma: first evidence of 4'-hydroxylated metabolites in breast cancer patients.

There is increasing evidence that the clinical efficacy of tamoxifen, the first and most widely used targeted therapy for estrogen-sensitive breast cancer, depends on the formation of the active metabolites 4-hydroxy-tamoxifen and 4-hydroxy-N-desmethyl-tamoxifen (endoxifen). Large inter-individual variability in endoxifen plasma concentrations has been observed and related both to genetic and environmental (i.e. drug-induced) factors altering CYP450s metabolizing enzymes activity. In this context, we have developed an ultra performance liquid chromatography-tandem mass spectrometry method (UPLC-MS/MS) requiring 100 μL of plasma for the quantification of tamoxifen and three of its major metabolites in breast cancer patients. Plasma is purified by a combination of protein precipitation, evaporation at room temperature under nitrogen, and reconstitution in methanol/20 mM ammonium formate 1:1 (v/v), adjusted to pH 2.9 with formic acid. Reverse-phase chromatographic separation of tamoxifen, N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen and 4-hydroxy-N-desmethyl-tamoxifen is performed within 13 min using elution with a gradient of 10 mM ammonium formate and acetonitrile, both containing 0.1% formic acid. Analytes quantification, using matrix-matched calibration samples spiked with their respective deuterated internal standards, is performed by electrospray ionization-triple quadrupole mass spectrometry using selected reaction monitoring detection in the positive mode. The method was validated according to FDA recommendations, including assessment of relative matrix effects variability, as well as tamoxifen and metabolites short-term stability in plasma and whole blood. The method is precise (inter-day CV%: 2.5-7.8%), accurate (-1.4 to +5.8%) and sensitive (lower limits of quantification comprised between 0.4 and 2.0 ng/mL). Application of this method to patients' samples has made possible the identification of two further metabolites, 4'-hydroxy-tamoxifen and 4'-hydroxy-N-desmethyl-tamoxifen, described for the first time in breast cancer patients. This UPLC-MS/MS assay is currently applied for monitoring plasma levels of tamoxifen and its metabolites in breast cancer patients within the frame of a clinical trial aiming to assess the impact of dose increase on tamoxifen and endoxifen exposure.

Antibody-indocyanin conjugates for immunophotodetection of human squamous cell carcinoma in nude mice.

We have recently shown that immunophotodetection of human colon carcinomas in nude mice and in patients is possible by using anti-carcinoembryonic antigen monoclonal antibodies (MAb) coupled to fluorescein. The most common clinical application of photodiagnosis has been for the detection of squamous cell carcinomas (SCC) in the upper respiratory tract, but the free dyes used have a poor tumor selectivity. We selected the known MAb E48 directed against SCC and coupled it to a fluorescent dye: indopentamethinecyanin (indocyanin). This dye has an advantage over fluorescein in that it emits a more penetrating fluorescent red signal at 667 nm after excitation with a laser ray of 640 nm. In vitro, an conjugate with an indocyanin:MAb molar ratio of 2, and an additional trace labeling with 125I, showed more than 80% of binding to cells from the SCC line A431. In vivo, when injected i.v. into nude mice bearing xenografts of the same carcinoma line, the MAb E48-(indocyanin)2 conjugate was almost as efficient as the unconjugated MAb E48 in terms of specific tumor localization: 15% of the injected dose per g of tumor at 24 h after injection and a tumor:overall normal tissue ratio of 6-8. There was no selective tumor localization of an irrelevant IgG1-(indocyanin)2 conjugate. Immunophotodetection of the s.c. SCC xenografts on mice given injections of 100 micrograms of MAb E48-(indocyanin), conjugate (representing 1 microgram of indocyanin) was performed at 24 h. Upon laser irradiation, clearly detectable red fluorescence from the indocyanin-MAb conjugate was observed specifically in the SCC xenografts across the mouse skin. In comparison, injection of 100 micrograms of a MAb E48 coupled to 2 micrograms of fluorescein gave a specific green fluorescence signal in the tumor xenografts, which was detectable, however, only after removing the mouse skin. Injection i.v. of a 15 times higher amount of free indocyanin (15 micrograms) gave a diffuse red fluorescence signal all over the mouse body with no definite increase in intensity in the tumor, indicating a lack of tumor selectivity of the free dye. The results demonstrate the possibility of broadening and improving the efficiency of tumor immunophotodiagnosis by coupling to a MAb directed against SCC, a fluorescent dye absorbing and emitting at higher wavelength than fluorescein, and thus having deeper tissue penetration and lower tissue autofluorescence. Such a demonstration opens the way to a new form of clinical immunophotodiagnosis and possibly to the development of a more specific approach to phototherapy of early bronchial carcinomas.

Micro-patterning of biomolecules on polymer substrates.

UV−excimer laser photoablation was used, in combination with surface blocking techniques, to pattern proteins on the surfaces of polyimide and poly(ethylene terephthalate). This technique involves physical adsorption of avidin through laser-defined openings in low-temperature laminates or adsorbed protein blocking layers. Visualization of biomolecular patterns were monitored using avidin and fluorescein-labeled biotin as a model receptor−ligand couple. Adsorbed proteins could be shown to bind to UV-laser-treated polymer surfaces up to three times higher than on commercially available polymers. UV-laser photoablation was also used for the generation of three-dimensional structure, which leads to the possibility of biomolecule patterning within polymer-based microanalytical systems. The simplicity and easy handling of the described technique facilitate its application in microdiagnostic devices.

Periphere okklusive Vaskulopathie bei einer Patientin mit kombinierter Präeklampsie und Alpha-Thalassämie minor [Peripheral occlusive retinal vasculopathy in a woman with combined preeclampsia and alpha thalassemia minor].

Normalerweise eine Störung der ersten Schwangerschaft, ist die Präeklampsie charakterisiert durch eine arterielle Hypertonie (> 140 mmHg systolisch oder > 90 mmHg diastolisch), die in der Regel nach der 20. Schwangerschaftswoche auftritt und von einer Proteinurie begleitet wird [1]. Die Präeklampsie wird als ,,schwer" bezeichnet, wenn sie mit einer wesentlichen Erhöhung des Blutdrucks (> 160 mmHg systolisch oder > 110 mmHg diastolisch), schwerer Proteinurie, Oligurie, Lungenödem, abdominalen Schmerzen, Leberfunktionsstörungen, Thrombozytopenie und visuellen oder zerebralen Symptomen einhergeht. Eine Eklampsie wiederum ist durch die Entwicklung von tonisch-klonischen Anfällen bei einer präeklamptischen Patientin charakterisiert. Bei der Alpha-Thalassämie tritt ein Defekt von 2 oder mehr der 4 Alpha-Globin-Gene auf. Von einer Alpha-Thalassämie minor spricht man, wenn 2 Alpha-Ketten-Gene deletiert sind. Sie tritt häufig bei Menschen aus Afrika, Südostasien, dem westindischen und mediterranen Raum auf. Die Alpha-Thalassämie minor verursacht eine milde bis moderate mikrozytäre Anämie. Wir berichten über eine Patientin mit peripherer okklusiver Vaskulopathie im Rahmen einer kombinierten Präeklampsie und Alpha-Thalassämie minor.

Bénéfices de l'utilisation de la clozapine en première intention chez de jeunes patients schizophrènes : quelques données à propos de six patients.

Résumé : La clozapine (Leponex®) est un neuroleptique atypique utilisé depuis une quarantaine d'années (synthétisée en 1959) dans le traitement de la schizophrénie résistante. Son utilisation a fait l'objet de controverses importantes en raison de son profil d'effets secondaires, potentiellement fatals (agranulocytose), et a entraîné son retrait de certains pays pendant de nombreuses années, malgré certaines caractéristiques qui en font une molécule très intéressante sur le plan clinique. On peut citer à cet égard une efficacité antipsychotique importante tant sur les symptômes positifs que sur les symptômes négatifs de la maladie, ainsi que l'absence d'effets secondaires extrapyramidaux, tels que ceux entraînés par les neuroleptiques classiques. Depuis la réadmission de la clozapine par la FDA aux Etats-Unis en 1990, suite notamment aux travaux montrant l'amélioration, grâce à cette molécule, des dyskinésies tardives induites par les neuroleptiques classiques, on assiste à un regain d'intérêt marqué pour ses possibilités thérapeutiques. L'indication reste toutefois limitée à l'heure actuelle au traitement de la schizophrénie résistante à d'autres neuroleptiques, donc un traitement en deuxième intention. Sachant que l'évolution de la schizophrénie est influencée, entre autres facteurs, par la durée des manifestations symptomatiques, il nous a semblé intéressant d'évaluer le devenir de jeunes patients schizophrènes mis d'emblée au bénéfice d'un traitement par la clozapine. C'est le sujet de la présente étude. Cette étude a été initialement conçue comme une étude de cohorte, randomisée, en double aveugle, multi-site à l'échelle romande, avec un suivi des patients sur une année. Les difficultés rencontrées, qui ont abouti à une interruption précoce ne permettant le relevé que des observations de six patients, sont détaillées. Après une brève introduction sur la schizophrénie et sur la clozapine, ce travail décrit l'historique de l'étude, ses buts et sa méthodologie. Suit une description des six patients et leur évolution au cours de l'étude. Dans le chapitre IV, les résultats sont analysés et discutés dans une perspective descriptive. Précédant la bibliographie et les annexes, la conclusion fournit l'opportunité de discuter les apports et les limites de ce travail, en le resituant dans le contexte international actuel de regain d'intérêt pour l'utilisation de la clozapine dans le traitement de la schizophrénie.

Bilateral Uveal Pigmented Alterations With Remarkable Evolution: Long Term Follow-Up in a Case of Possible Bilateral Diffuse Uveal Melanocytic Proliferation

Purpose: to describe a case of probable bilateral diffuse uveal melanocytic proliferation (BDUMP) with scleral involvement, free from systemic malignancies and cataract. Methods: fifty months of follow up with recurrent complete ophthalmological examinations, including fundus photography, fluorescein/indocyanine green angiography (FA) and optical coherence tomography (OCT). Investigations also included an electroretinography (ERG) and histological examination of scleral biopsy. Extraocular malignancies were repeatedly searched. Results: the patient was a 61 year-old Italian man with chronic hepatitis type C. At first visit his best corrected visual acuity (BCVA) was 20/32 in OS and 20/25 in OD. Funduscopy showed multiple patch-shaped pigmented alterations involving macular region and mid retinal periphery. FA showed corresponding areas of late-phase hyperfluorescent pinpoints (figure 1a, OS) and intemediate-phase hypocyanescence (figure 1b, OS), with subtle serous neurosensory retinal detachment confirmed by OCT. Photopic and scotopic ERG tested normal. Systemic prednisone was administered for one month without any improvement. After ten months round pigmentary lesions appeared also in superior scleral surface of both eyes. Biopsy allowed to disclose slightly pigmented spindle cells. BCVA worsened for further 10 months, with enlargement of FA alteration areas but lenses still clear. After 30 months spontaneous coalescence and atrophy of retinal lesions started, paralleled by progressive visual recovery. At the end of our follow up BCVA was 20/25 in OU while scleral pigmentary lesions remained unchanged. Conclusions: we report the case of a patient with main features of BDUMP and some unusual findings. Although not all classical diagnostic criteria were fulfilled, the presence of scleral pigmented lesions and spontaneous visual recovery may enlarge clinical spectrum of the disease.

Intravitreal ranibizumab (Lucentis) in the treatment of retinal angiomatous proliferation (RAP).

BACKGROUND: Retinal angiomatous proliferation (RAP) is a distinct variant of neovascular age-related macular degeneration (AMD). The aim of this study is to evaluate the functional and anatomic outcome after intravitreal ranibizumab (Lucentis) treatment in patients with RAP. METHODS: Prospective study of consecutive patients with newly diagnosed or recurrent RAP treated with intravitreal ranibizumab at the Jules Gonin Eye Hospital between March 2006 and December 2007. Baseline and monthly follow-up visits included best-corrected visual acuity (BCVA), fundus exam and optical coherence tomography. Fluorescein and indocyanine green angiography were performed at baseline and repeated at least every 3 months. RESULTS: Thirty-one eyes of 31 patients were treated with 0.5 mg of intravitreal ranibizumab for RAP between March 2006 and December 2007. The mean age of the patients was 82.6 years (SD:4.9). The mean number of intravitreal injections administered for each patient was 5 (SD: 2.4, range 3 to 12). The mean follow up was 13.4 months (SD: 3, range 10 to 22). The baseline mean logMAR BCVA was 0.72 (SD: 0.45) (decimal equivalent of 0.2). The mean logMAR BCVA was improved significantly (P < 0.0001) at the last follow-up to 0.45, SD: 0.3 (decimal equivalent 0.35). The visual acuity (VA) improved by a mean of 2.7 lines (SD 2.5). Mean baseline central macular thickness (CMT) was 376 microm, and decreased significantly to a mean of 224 microm (P < 0.001) at the last follow-up. Mean reduction of CMT was 152 microm (SD: 58). An average of 81.5% of the total visual improvement and 85% of the total CMT reduction occurred during the first post-operative month after one intravitreal injection of ranibizumab. During follow-up, an RPE tear occurred in one eye (3.2%) of the study group. No injection complications or systemic drug-related side-effects were noted during the follow-up period. CONCLUSIONS: Intravitreal ranibizumab injections appeared to be an effective and safe treatment for RAP, resulting in visual gain and reduction in macular thickness. Further long-term studies to evaluate the efficacy of intravitreal ranibizumab in RAP are warranted.

Intravitreal ranibizumab (Lucentis) for the treatment of myopic choroidal neovascularization.

BACKGROUND: Macular choroidal neovascularization (CNV) is one of the most vision-threatening complications of myopia, which can lead to severe vision loss. The purpose of this study was to evaluate the safety and efficacy of intravitreal ranibizumab in the treatment of myopic CNV. METHODS: We conducted a prospective, consecutive, interventional study of patients with subfoveal or juxtafoveal CNV secondary to pathologic myopia (PM) treated with intravitreal injection of ranibizumab in the Jules Gonin University Eye Hospital from June 2006 to February 2008. Best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and fluorescein angiography (FA) were performed at baseline and monthly for all patients. Indications for retreatment were loss in BCVA associated either with persistent leakage from CNV shown on FA, and/or evidence of CNV activity on OCT. RESULTS: The study included 14 eyes of 14 patients. The mean spherical equivalent refractive error was -12.5 (range, -8.0 D to -16.0 D). Mean time of follow-up was 8.4 months (range from 3 to 16 months, SD: 3). The mean number of intravitreal injections administered for each patient was 2.36 (SD 1.5). The mean initial visual acuity (VA) was 0.19 decimal equivalent (log-MAR: 0.71, SD: 0.3). A statistically significant improvement to a mean VA of 0.48 decimal equivalent (log-MAR:0.32, SD: 0.25) was demonstrated at the final follow-up. VA improved by a mean of 3.86 (SD 2.74) lines. Nine patients (64%) demonstrated a gain of 3 or more lines. Mean central macular thickness (CMT) measured with OCT was 304 microm (SD: 39) at the baseline, and was reduced significantly at the final follow-up to 153 microm (SD: 23). Average CMT reduction was 170 microm (SD: 57). No injection complications or drug-related side effects were noted during the follow-up period. CONCLUSIONS: In this small series of eyes with limited follow-up, intravitreal ranibizumab was a safe and effective treatment for CNV secondary to PM, resulting in functional and anatomic improvements.

Peculiar findings in a case of bilateral uveal pigmented lesions.

PURPOSE: To describe a probable case of bilateral diffuse uveal melanocytic proliferation (BDUMP) with unusual manifestations and prognosis. DESIGN: Case report. METHODS: Clinical follow-up of the patient lasting 50 months with recurrent fundus examination using color photographs, angiography, ultrasound, and optical coherence tomography. Serological and radiological investigations were performed to assess possible extraocular alterations. RESULTS: In both eyes patch-shaped pigmented alterations of the fundus were revealed. Fluorescein and indocyanine angiography evidenced corresponding areas of hyperfluorescent pinpoints and subtle serous detachment of the neurosensory retina, respectively. Ten months after the initial evaluation, flat pigmentary lesions appeared in the superior scleral surface of the right eye and underwent histological examination. After an initial decrease in visual acuity, the patient experienced a spontaneous recovery. He did not develop cataracts or any systemic malignancies. CONCLUSIONS: Although not all the criteria for the diagnosis were fulfilled, clinical findings were compatible with BDUMP. The presence of scleral pigmented lesions and the good visual prognosis may widen the spectrum of this rare disease.

Apport de l'angiographie au vert d'indocyanine (ICG) dans la localisation des néovascularisations chororoidiennes occultes [Value of indocyanine green angiography in localization of occult choroid neovascularization]

PURPOSE: To determine the role of Indocyanin Green (ICG) angiography in localizing occult new vessels associated with age-related macular degeneration (ARMD) and assess the possibilities of ICG guided laser photocoagulations. PATIENTS AND METHODS: Fluorescein and ICG angiographies (IMAGEnet system) of 62 patients with occult new vessels (ONV), serous (SPED) or vascular (VPED) pigment epithelium detachment have been studied. RESULTS: Based on fondoscopic examination and fluorescein angiography, 43 eyes (69%) disclosed ONV, 8 (13%) SPED and 11 (18%) VPED. Choroidal neovascularisation was confirmed by ICG angiography in 37 ONV cases (86%), in 8 (72%) VPED cases, but in no SPED. Conversion of ONV in classical neovascular membranes was possible in 19 ONV cases (44%) and in 6 (54%) VPED cases, making a laser photocoagulation possible in 9 eyes (36%). CONCLUSION: ICG angiography plays an important role in the evaluation, classification and laser treatment of patients with ONV secondary to ARMD.