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Biomedical subjects

Reza Dana

Publications and source records attributed to Reza Dana.

9 recordsLinked to original sources
PubMed2006

Nonvascular VEGF receptor 3 expression by corneal epithelium maintains avascularity and vision.

Transparency of the cornea, the window of the eye, is a prerequisite for vision. Angiogenesis into the normally avascular cornea is incompatible with good vision and, therefore, the cornea is one of the few tissues in the human body where avascularity is actively maintained. Here, we provide evidence for a critical mechanism contributing to corneal avascularity. VEGF receptor 3, normally present on lymphatic and proliferating blood vascular endothelium, is strongly constitutively expressed by corneal epithelium and is mechanistically responsible for suppressing inflammatory corneal angiogenesis.

Animals↗
PubMed2006

Chemokine receptor CCR5 expression in conjunctival epithelium of patients with dry eye syndrome.

OBJECTIVE: To characterize chemokine receptor CCR5 expression on the conjunctival epithelium in dry eye syndromes. METHODS: Conjunctival impression cytology samples were obtained from normal subjects (n = 15) and patients with dry eye syndrome (n = 45). Cells were harvested from impression cytology samples, and flow cytometry was performed to quantitatively analyze the cell surface expression of chemokine receptor CCR5. Characterization of CCR5-positive cells was done by 2-color flow cytometry using fluorescein-conjugated anti-CCR5 and phycoerythrin-conjugated anti-CD45 antibodies (where CD45 is a marker for bone marrow-derived cells). To study CCR5 messenger RNA transcripts, real-time polymerase chain reaction was done on RNA isolated from the impression cytology samples of normal subjects (n = 5) and patients with dry eye syndrome (n = 14). RESULTS: We found significant up-regulation in cell surface expression of CCR5 in patients with both aqueous tear-deficient and evaporative forms of dry eye syndrome (P<.001). The real-time polymerase chain reaction results (for messenger RNA) corroborated the flow cytometry data (for protein). The majority of the cells expressing CCR5 were non-bone marrow-derived resident epithelial cells of the conjunctiva. CONCLUSION: Our findings suggest that CCR5 up-regulation is significantly associated with dry eye syndrome-associated ocular surface disease. Clinical Relevance Chemokine receptor CCR5 or its ligands may serve as useful targets for modulation of tissue immunoinflammatory responses in dry eye syndromes.

Adult↗
PubMed2006

Validation and repeatability of a short questionnaire for dry eye syndrome.

PURPOSE: To clinically validate and ascertain the repeatability of a short questionnaire for dry eye syndrome (DES), consisting of two questions pertaining to symptoms (dryness and irritation) and one question regarding previous history of clinically diagnosed DES. DESIGN: Clinical validation study with repeated assessments. METHODS: A short questionnaire for DES was administered to participants of two large cohort studies, the Women's Health Study (WHS) and the Physicians' Health Study (PHS). A supplementary questionnaire comprising 16 questions pertaining to symptoms was mailed to a subset of 450 WHS and 240 PHS participants, selected so that a third of these subjects had DES based on their response to the short questionnaire. Repeatability of the dryness and irritation symptom questions was ascertained using intraclass correlation coefficient (ICC). Standardized ophthalmologic examination was performed on 53 subjects. Sensitivity and specificity of the short questionnaire was determined using a combination of clinical tests to define clinical DES. RESULTS: An ICC of 0.75 for dryness and 0.65 for irritation was found between subsequent measurements. Participants' responses to the dryness and irritation questions were highly correlated (r = 0.75) with a score derived from responses to the longer 16-symptom questionnaire. The short questionnaire for DES had a sensitivity of 77% and specificity of 83% when cutoff point for clinical DES was Schirmer 1 value </=10 mm or tear breakup time <10 seconds. CONCLUSION: The short questionnaire for DES is a sensitive and repeatable tool that is easy to administer in large epidemiologic research studies as well as clinical research.

Dry Eye Syndromes↗
PubMed2006

Advances in immunology: from bench to bedside--a symposium at the 2005 Annual Meeting of the Federation of Clinical Immunology Societies (FOCIS), Boston, MA, USA.

The American Uveitis Society sponsored a symposium at the recent 2005 Annual FOCIS meeting in Boston, MA, USA, that was organized by the authors of this report. The symposium was designed to bring together several leaders in the broad field of immunology and investigators in ocular immunology to discuss three interrelated areas of interest: (i) animal models of ocular inflammation; (ii) interface of innate and adaptive immunity; and (iii) immune regulation. A brief summary of the salient points of the symposium is given.

Adaptation, Physiological↗
PubMed2005

Chronic ocular surface disease after allogeneic bone marrow transplantation.

Graft-versus-host disease (GVHD) is a common complication of allogeneic bone marrow transplantation (allo-BMT). Ocular surface disease (OSD) is one of the most common manifestations of chronic ocular GVHD, yet little is known about it. In this article, we review the available literature on this condition and present results from our study of the manifestations of OSD in the chronic phase (>3 months duration) post allo-BMT. Our study consisted of a retrospective chart review of 62 allo-BMT patients with chronic OSD evaluated at our center between 1995 and 2002. The clinical features, systemic associations, treatment, and status of OSD at the last follow-up are presented and discussed in the context of other reports of OSD in GVHD.

Journal Article↗
PubMed2005

Pathways of corneal and ocular surface inflammation: a perspective from the cullen symposium.

The goal of this symposium was to coalesce information presented by 22 investigators in the field of corneal and ocular surface inflammation into common pathways of inflammation. The perspective elucidated in this article defines the components of the normal ocular surface immune architecture and describes the consensus reached on the mechanisms/pathways involved in 1) acute inflammation; 2) late-stage (chronic) response; and 3) allergic disease. Seven diagrams didactically illustrate mechanisms. This paper is the introductory article in a supplement containing 18 articles by the symposium participants.

Journal Article↗
PubMed2005

Corneal antigen presentation: molecular regulation and functional implications.

Presentation of corneal antigens for induction of adaptive immune responses is mediated by corneal antigen-presenting cells (APC), including those that infiltrate the cornea in response to inflammatory stimuli and, to a lesser extent, those that reside in the cornea and up-regulate activation markers in response to inflammation. Significant progress has been made in the last decade in dissecting the molecular mechanisms that mediate APC infiltration into the cornea. However, it has recently been determined that exit of APC out of the cornea is critical for induction of T cells that normally reside outside of the cornea in lymphoid reservoirs. Much less is understood about the molecular regulation of APC egress from the cornea, but our laboratory has recently discovered that APC access to afferent lymphatics and draining lymph nodes requires signaling mediated by VEGFR-3. We describe herein the functional implication of APC trafficking and the prospects for novel immunomodulatory strategies based on regulating APC migration.

Journal Article↗
PubMed2005

Radiotherapy-induced ocular surface disease.

Today radiation is routinely used as a therapeutic modality for select tumors of the orbit, adnexa, paranasal sinus, and nasopharynx. Despite significant improvements in mechanisms of delivery and protective shielding, acute and chronic complications of radiation can affect different segments of the eye. In this report, we provide an overview of ocular damage secondary to radiotherapy. We identify the characteristic clinical changes and underlying pathophysiologic mechanisms involving the ocular surface and provide a rational approach to their prevention and treatment.

Eye↗