Evaluating the Completeness of ClinicalTrials.gov.

Background: To date, although studies have been conducted to assess compliance with listing clinical trial information, to our knowledge there is nothing in the literature examining the completion and accuracy of clinical trial site information on ClinicalTrials.gov .

Methods: We compared clinical trial information originating from ClinicalTrials.

Characterization and localization of adenosine A2 receptors in bovine rod outer segments.

Previous work from this laboratory has shown that retinal adenosine A2 binding sites are localized over outer and inner segments of photoreceptors in rabbit and mouse retinal sections. In the present study, adenosine receptor binding has been characterized and localized in membranes from bovine rod outer segments (ROS). Saturation studies with varying concentrations (10-150 nM) of 5'-(N-[2,8-3H]ethylcarboxamido)adenosine ([3H]NECA) and 100 micrograms of ROS membrane protein show a single site with a KD of 103 nM and a Bmax of 1.

Characterization of adenosine A2 receptors in bovine retinal pigment epithelial membranes.

The pharmacological characteristics of adenosine A2 receptors are described for membranes prepared from bovine retinal pigmented epithelial (RPE) cells. RPE cells were isolated after removal of retina, lysed by freeze-thawing, and membranes separated from cytoplasmic components. A single population of adenosine binding sites is present in RPE membranes, as determined from saturation analysis and competition binding assays.

Characterization of adenosine A2 receptors in bovine retinal membranes.

Two classes of extracellular receptors for adenosine, A1 and A2, have been demonstrated in the mammalian retina. Our laboratory has previously reported the pharmacological characteristics of the mammalian retinal A1 receptors. We now report our characterization of retinal A2 receptors based on data obtained from both adenylate cyclase assays and radioligand binding studies.

Type I calmodulin-sensitive adenylyl cyclase is neural specific.

The distribution of type I calmodulin-sensitive adenylyl cyclase in bovine and rat tissues was examined by northern blot analysis and in situ hybridization. Northern blot analysis using poly(A)(+)-selected RNA from various bovine tissues indicated that mRNA for type I adenylyl cyclase was found only in brain, retina, and adrenal medulla, suggesting that this enzyme is neural specific. In situ hybridization studies using bovine, rabbit, and rat retina indicated that mRNA for type I adenylyl cyclase is found in all three nuclear layers of the neural retina and is particularly abundant in the inner segment of the photoreceptor cells.