OBJECTIVE To validate primer sets for use in reverse transcription quantitative PCR assays to measure gene expression of cytosolic phospholipase A2 (cPLA2) and microsomal prostaglandin E2 synthase 1 (mPGES1) in equine mononuclear cells and determine the effects of firocoxib, a selective cyclooxygenase 2 (COX-2) inhibitor, on COX-2, cPLA2, and mPGES1 gene expression following incubation of mononuclear cells with lipopolysaccharide (LPS).
ANIMALS 8 healthy adult horses.
PROCEDURES Peripheral blood mononuclear cells were isolated by density gradient centrifugation and incubated at 37°C with medium alone, firocoxib (100 ng/mL), LPS (1 ng/mL or 1 μg/mL), or combinations of firocoxib and both LPS concentrations. After 4 hours, supernatants were collected and tested for prostaglandin E2 (PGE2) concentration with an enzyme inhibition assay, and gene expression in cell lysates was measured with PCR assays.
RESULTS Primer pairs for cPLA2 and mPGES1 yielded single products on dissociation curve analyses, with mean assay efficiencies of 102% and 100%, respectively. Incubation with firocoxib and LPS significantly decreased PGE2 supernatant concentrations and significantly reduced COX-2 and mPGES1 gene expression, compared with values following incubation with LPS alone.
CONCLUSIONS AND CLINICAL RELEVANCE Primer sets for mPGES1 and cPLA2 gene expression in equine mononuclear cells were successfully validated. Firocoxib significantly decreased LPS-induced COX-2 and mPGES1 expression, suggesting that it may be useful in the control of diseases in which expression of these genes is upregulated.
A 1-year-old male eclectus parrot (Eclectus roratus) with a 3- to 4-month history of blepharospasm in the right eye was referred to a veterinary medical teaching hospital for further evaluation. Conventional medical treatments had been ineffective. The referring avian specialist had plucked a suspected ectopic feather from the right eye 6 weeks prior to the referral evaluation.
The parrot was sedated, and ophthalmic examination of the right eye with slit-lamp biomicroscopy revealed a 3 × 2 × 2-mm raised vascular mass with a focally pigmented center associated with the temporal aspect of the leading edge of the third eyelid. No abnormalities were detected in the left eye.
TREATMENT AND OUTCOME
The parrot was anesthetized, and the right eye mass was excised and submitted for histologic examination. Histologically, there was a single pigmented feather follicle bulb surrounded by multiple discrete lymphoid follicles and moderate lymphoplasmacytic inflammation within the substantia propria of the third eyelid conjunctiva. The histologically normal feather follicle in an abnormal location classified the lesion as a choristoma. Nine months after surgery, the parrot had no signs of ocular discomfort and no overt regrowth of the feather follicle.
For the eclectus parrot of this report, a lesion caused by normal differentiation of an ectopic feather follicle in the right third eyelid was successfully treated. A third eyelid choristoma appears to be a hitherto unreported pathological finding in avian species. Although rare, the presence of a choristoma should be considered as a differential diagnosis for birds with blepharospasm.