Mineralocorticoid regulation of cyclooxygenase-2 expression in rat renal medulla.

The renal inner medulla and its distal one-third, the papilla, are major sites of prostanoid synthesis involved in water and electrolyte homeostasis. These sites contain variable levels of cyclooxygenase (COX)-2, a key prostaglandin synthase enzyme that is sensitive to adrenal steroids. Immunoreactive renal medullary COX-2, restricted to interstitial cells in control adult rats, shows a gradient of intense staining at the tip of the papilla that gradually diminishes to undetectable levels in the proximal inner medulla.

Cyclooxygenase-2 inhibitor blocks expression of mediators of renal injury in a model of diabetes and hypertension.

Background: We previously reported that renal cortical cyclooxygenase (COX-2) expression increased following subtotal nephrectomy, and chronic treatment with a selective COX-2 inhibitor, SC58236, reduced proteinuria and retarded the development of glomerulosclerosis. The present studies were designed to examine the effects of COX-2 inhibition in a model of diabetic nephropathy.

Methods: Rats were divided into three groups: control, diabetic (streptozotocin-induced diabetic animals with superimposed DOCA/salt hypertension; right nephrectomy and DOCA treatment), and treated (administration of the selective COX-2 inhibitor, SC58236, to a subset of diabetic/DOCA/salt rats).

Near-work activity, night-lights, and myopia in the Singapore-China study.

Objective: To investigate the relationship among near-work activity, night-lights, and myopia in schoolchildren in Singapore and Xiamen, China.

Methods: The refractive error and ocular dimensions of 957 Chinese schoolchildren aged 7 to 9 years in Singapore and Xiamen, China, were determined using cycloplegic autorefraction and A-scan ultrasound biometry. Information on near-work activity (number of books read per week, reading in hours per day) and night-light use before age 2 years was obtained.