Biomedical subjects

Chi-Chao Chan

Publications and source records attributed to Chi-Chao Chan.

98 records · Page 6Linked to original sources

PubMedDate not supplied

Microdissection and gene rearrangement analysis of paraffin-embedded specimens of orbital malignant lymphoma.

PURPOSE: To determine whether a definite diagnosis of malignant lymphoma can be made from paraffin-embedded archived orbital specimens by gene rearrangement analysis using microdissection and polymerase chain reaction (PCR). METHODS: Specimens from four patients with histopathologically diagnosed orbital malignant lymphoma were examined. The malignant cells were microdissected off the paraffin-embedded specimens. DNA was extracted from the cells, and the immunoglobulin heavy chain ( IgH) gene was amplified by PCR. Gene rearrangements were detected by using primers for the third framework (FR3A), the second framework (FR2A), and the complementary determining region 3 (CDR3). Translocation of the B-cell lymphoma/leukemia-2 ( bcl-2) gene was also examined. RESULTS: Malignant cells were present on the slides of the paraffin-embedded specimens of three of four cases. The specimens from these three cases showed IgH rearrangements for FR3A, FR2A, and CDR3. A bcl-2-associated translocation was also detected in one case. CONCLUSIONS: Gene rearrangement analysis is applicable to paraffin-embedded archived orbital specimens to confirm a diagnosis of malignant lymphoma. The advantage of this method is that only a small specimen is needed because the detection sensitivity is high.

Complementarity Determining Regions↗

PubMedDate not supplied

Conjunctival involvement with T-cell prolymphocytic leukemia: report of a case and review of the literature.

T-cell prolymphocytic leukemia is a rare and highly aggressive hematological neoplasm. A patient with T-cell prolymphocytic leukemia presented with bilateral perilimbal conjunctival infiltrates. Conjunctival biopsy showed aggregates of large atypical lymphocytes in the substantia propria with a concentration of atypical cells in the perivascular areas. Immunophenotyping of the malignant cells identified an abnormal clonal T-cell population consistent with T-cell prolymphocytic leukemia. A literature review of all reports of conjunctival involvement with leukemia was performed. The three cases of ocular prolymphocytic leukemia, including the one case of ocular T-cell prolymphocytic leukemia, are discussed in detail as well as 14 reported clinical cases of biopsy-proven conjunctival leukemia. The majority of cases occurred in the setting of acute leukemia, and conjunctival involvement was frequently a presenting sign of the disease or signified disease relapse. Conjunctival involvement with leukemia was consistent with good visual acuity; however, it portended a poor prognosis.

Alemtuzumab↗

PubMedDate not supplied

Primary testicular and intraocular lymphomas: two case reports and a review of the literature.

Testicular lymphoma is a rare neoplasm of the testis that is most commonly seen in older patients. It metastasizes preferentially to extranodal sites, including the skin, central nervous system, Waldeyer ring, contralateral testis, and lung. Two case reports of patients with a history of testicular lymphoma who developed involvement of the vitreous and retina are presented. These are interesting cases as the testis, central nervous system, and eye are all immune privileged organs, which may account for occurrence of disease in these sites. Histopathologic examination of diagnostic vitrectomy specimens from both cases showed atypical lymphoid cells with immunoglobulin heavy chain (IgH) gene rearrangements, consistent with the diagnosis of intraocular B-cell lymphoma. The results of a literature review of all reports of ocular involvement with testicular lymphoma are discussed. Patients with testicular lymphoma are at risk for relapse, particularly in the central nervous system. Clinicians should be suspicious for intraocular lymphoma in patients with a history of testicular lymphoma who present with vitritis or retinal lesions.

Aged↗

PubMedDate not supplied

Ophthalmic manifestations and histopathology of infantile nephropathic cystinosis: report of a case and review of the literature.

Cystinosis is a rare autosomal recessive metabolic disorder characterized by the intracellular accumulation of cystine, the disulfide of the amino acid cysteine, in many organs and tissues. Infantile nephropathic cystinosis is the most severe phenotype. Corneal crystal accumulation and pigmentary retinopathy were originally the most commonly described ophthalmic manifestations, but successful kidney transplantation significantly changed the natural history of the disease. As cystinosis patients now live longer, long-term complications in extrarenal tissues, including the eye, have become apparent. A case of an adult patient with infantile nephropathic cystinosis is reported. He presented with many long-term ocular complications of cystinosis. After 4 years of follow-up, the patient died from sepsis. Pathology of the phthisical eyes demonstrated numerous electron-transparent polygonal spaces, bounded by single membrane, in corneal cells, retinal pigment epithelial cells, and even choroidal endothelial cells. The ophthalmic manifestations and pathology of infantile nephropathic cystinosis are discussed and reviewed in light of the current report and other cases in the literature.

Adult↗

PubMedDate not supplied

Experimental autoimmune uveitides: multiple antigens, diverse diseases.

Human autoimmune uveitides are diverse and complex. Animal models have been developed for studying the pathogenesis of uveitis because of the difficulties in obtaining tissues from a patient's inflamed eye for experiments. There are animal models for experimental uveitis that provoke inflammation of different tissues of the eye and represent different forms of uveitis. Since inflammatory cells can infiltrate any part of the uvea and spill over to nonuveal tissues, such as retina, various antigens have been used to induce uveitis. Most of those models that represent autoimmune forms of uveitis are induced with proteins specific for photoreceptor cells (S-antigen, IRBP, rhodopsin, recoverin, phosducin). Nonretinal antigens, including melanin-associated proteins and myelin basic protein, are also good inducers of uveitis in animals.

Animals↗

PubMedDate not supplied

Cytotoxic T lymphocyte-associated antigen 4 blockade in patients with metastatic melanoma: a new cause of uveitis.

Cytotoxic T Lymphocyte-associated antigen 4 (CTLA-4) is an important costimultory receptor expressed on activated T cells. CTLA-4 blockade using a monoclonal antibody (mAb) in conjunction with tumor vaccines has improved tumor responses in animal models and enhanced numerous models of T cell-associated autoimmune diseases. Two patients with stage IV metastatic melanoma vaccinated with the gp 100 melanocyte/melanoma differentiation antigen either before or during anti-CTLA-4 mAb therapy developed uveitis. This is the first report of autoimmune disease involving the eye in patients treated with anti-CTLA-4 mAb. This suggests that CTLA-4 is an important regulatory molecule for maintenance of tolerance to melanosomal antigens and prevention of uveitis.

Antibodies, Monoclonal↗

PubMedDate not supplied

Intraocular lymphoma: update on diagnosis and management.

BACKGROUND: Primary intraocular lymphoma (PIOL) is a subset of primary central nervous system lymphoma (PCNSL) in which lymphoma cells initially invade the retina, vitreous, or optic nerve head, with or without concomitant CNS involvement. The incidence of this previously rare condition has increased dramatically. Given its nonspecific presentation and aggressive course, PIOL provides a diagnostic and therapeutic challenge. METHODS: We review the current strategies for diagnosis and treatment of PIOL and present our own experience with PIOL. RESULTS: Recent developments in the diagnosis of PIOL include immunohistochemistry, flow cytometry, cytokine evaluation, and molecular analysis. However, definitive diagnosis still requires harvesting of tissue for histopathology. Optimal treatment for PIOL remains unclear. Initial therapeutic regimens should include methotrexate-based chemotherapy and radiotherapy to the brain and eye. In addition, promising results have been seen with intravitreal methotrexate and autologous stem cell transplantation for recurrent and refractory disease. CONCLUSIONS: Efforts to further determine the immunophenotype and molecular characteristics of PIOL will continue to assist in the diagnosis of PIOL. Future studies are required to determine the role of radiotherapy and optimal local and systemic chemotherapeutic regimens.

Antimetabolites, Antineoplastic↗

PubMedDate not supplied

Immunotherapeutic approaches in ocular inflammatory diseases.

This comprehensive review discusses immunotherapeutic approaches to ocular inflammatory diseases, updates information provided in the literature, and presents clinical experiences with an emphasis on autoimmune uveitis at the National Eye Institute, United States. Current medical and surgical therapeutic approaches, including medications such as corticosteroids, anti-metabolites, alkylating agents, calcineurin and purine synthesis inhibitors, biologics as well as some anti-infectious agents, are reviewed along with new modalities and experimental approaches. Most immunosuppressive therapies have significant adverse effects. Physicians must be familiar with the pharmacology of the available drugs and aware of the philosophies behind the treatment.

Anti-Inflammatory Agents↗