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Featured researches published by S.A. Callejo.


Canadian Journal of Ophthalmology-journal Canadien D Ophtalmologie | 2003

Cyclooxygenase-2 expression in uveal melanoma: novel classification of mixed-cell-type tumours

Andresson Figueiredo; A.L. Caissie; S.A. Callejo; Ian W. McLean; Phil Gold; Miguel N. Burnier

BACKGROUND The expression of cyclooxygenase-2 (COX-2), an inducible prostaglandin (PG) synthase, has been investigated in various human malignant diseases, such as cutaneous melanoma. We investigated the expression of COX-2 in uveal melanoma and related the findings to prognostic factors. METHODS In 40 cases of uveal melanoma, immunostaining for COX-2 was done. COX-2 expression was related to histopathological prognostic markers, such as cell type, the presence of lymphocytic infiltration and vascular closed loops in the tumour, and cytomorphometry results. RESULTS COX-2 expression was found in 58% of the cases, and it correlated with markers of poor prognosis, such as epithelioid cell type and the presence of lymphocytic infiltration and vascular closed loops. The uveal melanomas expressing COX-2 had larger nuclei, as determined by cytomorphometry. INTERPRETATION Whereas epithelioid tumours carry a worse prognosis than spindle cell tumours, until now it has not been possible to give a strong indication of prognosis in mixed-cell tumours. This study showed that mixed-cell tumours, representing the majority of uveal melanomas, may be further subclassified according to COX-2 expression, which serves as a marker of poor prognosis. The role of COX-2 in uveal melanoma should be further elucidated, and the use of COX-2 inhibitors warrants investigation as adjuvant treatment for this life-threatening malignant disease.


Pathobiology | 2004

Cell Proliferation Profile of Five Human Uveal Melanoma Cell Lines of Different Metastatic Potential

Jean-Claude Marshall; A.L. Caissie; S.A. Callejo; Emilia Antecka; Miguel N. Burnier

Objective: The aim of this study was to establish a proliferation profile of uveal melanoma cell lines, using different methods, and to compare it with their previously determined metastatic potential (MP). Methods: Four human uveal melanoma and one transformed human uveal melanocytic cell line were ranked according to proliferation profiles. The proliferation profiles of the cell lines were compared to their MPs, which were previously determined from an immunosuppressed rabbit model. Results: Ranking of the cell lines using pulse labeling with tritiated thymidine was similar to the MP of the cell lines. Conclusion: The correlation between the proliferative rate of the uveal melanoma cell lines and their previously determined MP resulted in the proposal of a new classification scheme: high proliferation/high MP, low proliferation/low MP, and high proliferation/no MP. High proliferative capacity of a cell line did not necessarily confer MP; therefore, further cellular functions/adaptations must be required for tumor cell dissemination, survival, and growth at a metastatic site.


Canadian Journal of Ophthalmology-journal Canadien D Ophtalmologie | 2003

Benign ocular adnexal tumours of a ocrine eccrine or hair follicle origin

Pinar Ozdal; S.A. Callejo; François Codère; Miguel N. Burnier

BACKGROUND The differential diagnosis of malignant eyelid tumours, particularly basal cell carcinoma (BCC), includes tumours of skin appendages. The incidence of these adnexal tumours has not been well established. This study aimed to determine the incidence and review the main clinicopathological features of benign tumours arising from skin appendages of the eyelid with apocrine, eccrine or hair follicle differentiation. METHODS The histopathological diagnoses of 7751 ophthalmic specimens retrieved from 6967 patients between September 1993 and March 2002 at the Henry C. Witelson Ophthalmic Pathology Laboratory and Registry, McGill University, Montreal, were retrospectively reviewed. Clinical data and histopathological diagnoses were obtained for 228 benign adnexal tumours of apocrine, eccrine or hair follicle origin. New histopathological slides were made from the paraffin-embedded specimens and stained with hematoxylin-eosin and periodic acid-Schiffs reagent. RESULTS Of the 228 benign adnexal tumours, 182 were diagnosed as apocrine or eccrine hydrocystoma (79.8%), 12 pilomatrixoma (5.3%), 12 syringoma (5.3%), 11 trichilemmoma (4.8%), 5 syringocystadenoma papilliferum (2.2%), 3 trichoepithelioma (1.3%) and 3 trichofolliculoma (1.3%). Discrepancies between clinical and histopathological diagnoses were noted in 22 cases (9.6%). INTERPRETATION Benign tumours originating from skin appendages of the eyelid are rare and frequently have apocrine or eccrine differentiation. These tumours, particularly those originating from the hair follicle, should be considered in the differential diagnosis of BCC of the eyelid.


Canadian Journal of Ophthalmology-journal Canadien D Ophtalmologie | 2004

The risk of other primary cancer in patients with uveal melanoma: a retrospective cohort study of a Canadian population.

S.A. Callejo; Saad Al-Khalifa; Pinar Ozdal; Chaim Edelstein; Miguel N. Burnier

BACKGROUND The incidence of second primary malignant tumours has doubled during the last 2 decades. These tumours now represent the sixth most common group of cancers. Many authors have described the presence of multiple primary cancers in patients with uveal melanoma. However, no studies have been performed using Canadian data. The purpose of this study was to describe the occurrence of other primary cancers diagnosed before or after uveal melanoma and to calculate the incidence of subsequent primary cancer in a Canadian cohort with uveal melanoma. METHODS We conducted a retrospective study of a cohort of patients with uveal melanoma diagnosed between 1990 and 2002 at a university-affiliated centre in Montreal. We reviewed medical records to identify patients in whom other, unrelated primary malignant disease had been diagnosed. We used the standardized incidence ratio to calculate the risk of development of a second, unrelated cancer following the diagnosis of uveal melanoma. RESULTS A total of 129 cases of uveal melanoma were diagnosed. Eighteen patients (14%) also had a diagnosis of an unrelated primary cancer. In nine patients the other cancer had been diagnosed first, and in nine patients the other tumour had been diagnosed after the uveal melanoma. There was no increased risk of development of any particular form of cancer studied for females or males. INTERPRETATION In our Canadian cohort, statistical analysis showed no increased risk of a second cancer, overall or by organ site, in male or female patients with uveal melanoma. As uveal melanoma is a rare type of cancer, analyses of a much larger cohort may be needed to accurately estimate the risk of development of a second primary cancer in patients with uveal melanoma.


Melanoma Research | 2004

Macrophage-derived soluble factor enhances melanoma inhibitory activity expression by uveal melanoma cells in vitro.

S.A. Callejo; Jean-Claude Marshall; Jonathan Cools-Lartigue; Vinicius S. Saraiva; Miguel N. Burnier

Melanoma inhibitory activity (MIA) is correlated with tumour progression and development of metastatic disease. Melanoma inhibitory activity, secreted by melanoma cells, is known to inhibit tumour cell attachment to the extracellular matrix enhancing their invasive potential. The regulatory pathways that lead to MIA expression have not yet been elucidated. It is well established that tumour cells and macrophages interact through soluble factors, preventing or enhancing tumour growth. The purpose of the present study was to determine whether soluble factor(s) derived from macrophages lead to the up-regulation of MIA production by human uveal melanoma cell lines (HUMCL) and whether MIA contributes to an increase in the invasive behaviour of HUMCL in vitro. Baseline MIA levels were measured by enzyme-linked immunosorbent assay in five HUMCL of known metastatic potential (92.1>SP6.5>OCM-1>MKT-BR>UW-1). Macrophage conditioned medium (MaCM) was placed on top of the HUMCL and MIA levels were measured at 6, 12, 24, and 36 h. The HUMCL were also seeded in a Matrigel chamber for 72 h and then cells invading the Matrigel were counted. The assay was repeated adding recombinant human MIA to the top layer of each well. All HUMCL expressed MIA at baseline (average of 31 ng/ml at 36 h). Following exposure to MaCM, MIA levels increased to an average of 45.2 ng/ml, with the 92.1 and SP6.5 cell lines expressing the highest MIA levels and UW-1 cell line expressing the lowest level. During the baseline invasion assay, the vast majority of cells (>95%) were found to adhere to the upper surface of the Matrigel. When MIA was added to the invasion chamber, no adhesion or invasion was observed. The results suggest, for the first time, that macrophages secrete a soluble factor(s) that may stimulate nearby melanoma cells to enhance their production of MIA in vitro. Furthermore, increased MIA production may, in turn, increase the invasive properties of the cells by modulating the attachment of HUMCL to the extracellular matrix.


Orbit | 2007

Immunohistochemical Panel of Undifferentiated Orbital Metastatic Carcinomas

Katyanne Dantas Godeiro; Alexandre N. Odashiro; Danilo N. Odashiro; Bruno F. Fernandes; Miguel N. Burnier; S.A. Callejo

Purpose: To examine the applicability of an immunohistochemical panel of seven monoclonal antibodies to identify the primary site of poorly differentiated orbital metastatic carcinomas. Material and Methods: Immunohistochemistry was performed to detect cytokeratin (CK) 7, CK20, thyroid transcription factor-1 (TTF-1), BRST1, BRST2, carcinoembryonic antigen (CEA) and prostate-specific antigen (PSA) in seven cases of poorly differentiated orbital metastases. Of the seven cases, four were female and three male. The youngest patient was thirty-six while the oldest was eighty-eight years of age. Results: The immunohistochemical panel alone was helpful to identify the primary source of the metastatic lesion in three out of the seven cases. Two of them were metastatic breast carcinomas (BRST1, BRST2 positive) and one was a prostate carcinoma (PSA positive). By correlating the immunohistochemical results with the previous clinical history, the primary site could be identified in two more cases. In those metastatic lesions, the positive staining for CK7, CK20, and CEA, associated with negative staining for BRST1, BRST2, PSA and TTF-1, indicated bladder as the probable primary site. In two out of seven cases, the metastatic tumor was only positive for CEA, therefore a primary site could not be identified. Conclusions: An immunohistochemical panel of poorly differentiated orbital metastases is helpful in the identification of the primary tumor site. The association of seven markers with the patients clinical history allowed for the positive identification of the primary tumor in the majority of these cases.


International Medical Case Reports Journal | 2017

Choroidal extranodal marginal zone lymphoma diagnosed by full-thickness retinochoroidal biopsy: case report and review of the literature

Ali Dirani; Guy Allaire; S.A. Callejo; Marie Lyne Belair; Katarzyna Biernacki; Christine Corriveau; Karim Hammamji

The case of an 89-year-old man who was referred for a painless decrease of vision in his right eye (RE) is reported. Fundus examination of the RE showed an elevated amelanotic lesion located in the posterior pole with an adjacent focal round pigmented lesion. There was also a more peripheral amelanotic lesion extending from 6 to 9 o’clock clockwise inferotemporally. Uveitis workup and imaging studies of brain and orbits were normal. A retinochoroidal biopsy was done and showed the presence of choroidal extranodal marginal zone lymphoma. The patient was treated with external beam radiotherapy. This report presents a review of the literature of all reported cases of choroidal extranodal marginal zone lymphoma.


Case reports in ophthalmological medicine | 2016

Conjunctival Involvement of T-Cell Lymphoma in a Patient with Mycosis Fungoides.

Sultan Aldrees; Pablo Zoroquiain; Sarah Alghamdi; Patrick Logan; S.A. Callejo; Miguel N. Burnier

Background. Ocular involvement in mycosis fungoides (MF) cases occurs in one-third of patients with the eyelid being the most frequent site affected; however, conjunctival involvement is rarely reported. Herein, we report a rare case of conjunctival involvement of MF. Case Presentation. A 66-year-old man who was previously diagnosed with MF in 2010 and was treated presented in 2014 complaining of foreign body sensation and redness in both eyes. Slit lamp examination of both eyes showed erythematous conjunctival growth that extended circumferentially. Physical examination revealed erythematous skin lesions on different body parts. Conjunctival biopsy was performed and revealed a dense, highly polymorphic lymphocytic population. The immunophenotype demonstrated a neoplastic T-cell origin consistent with MF. A diagnosis of conjunctival involvement by MF was made. The conjunctiva was treated with radiotherapy resulting in tumor regression. There were no recurrences at the 6-month follow-up. Conclusion. T-cell lymphoma should be considered in patients with a history of MF presenting with conjunctival and skin lesions.


Investigative Ophthalmology & Visual Science | 2005

Characterization of Ocular and Metastatic Uveal Melanoma in an Animal Model

P.L. Blanco; Jean Claude Marshall; Emilia Antecka; S.A. Callejo; João Pessoa Souza Filho; Vinicius S. Saraiva; Miguel N. Burnier


International Ophthalmology | 2008

Cyclooxygenase-2 expression in human irradiated uveal melanomas

Pinar Ozdal; S.A. Callejo; A.L. Caissie; C. Edelstein; S. Bakalian; Raul N. G Vianna; Miguel N. Burnier

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