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J Nelson

Publications and source records attributed to J Nelson.

459 records · Page 26Linked to original sources
PubMedDate not supplied

Polar spongioblastoma of the cervical spinal cord: case report.

Polar spongioblastomas are rare, histologically distinctive glial neoplasms that have been reported to involve the brain stem, third ventricle, aqueduct, and fourth ventricle. In this case report we describe a polar spongioblastoma of the cervical spinal cord in a patient who has survived 2 1/2 years without evidence of recurrent neoplasm.

Astrocytoma↗
PubMedDate not supplied

Sponsor/contract laboratory communication: a team approach to quality.

The true measure of any successful quality endeavor is the final product. The final product generated at contract facilities conducting nonclinical studies is the final report. This should be accurate, complete, and consistent with regard to the raw data, and in compliance itself. The final report resulting from studies conducted at contract laboratories should be reflective of the collaborative efforts of sponsor and laboratory staffs. The dual interaction of the respective Quality Assurance Units (QAUs) in ensuring that optimal study performance is maintained from initiation through final report submission is of paramount importance. Key to any productive sponsor/contract laboratory relationship is communication. The multidirectional flow of information inherent in the conduct of nonclinical studies must be managed to maximize the strengths of the principals involved, while at the same time assuring that consistent emphasis is placed on team focus. Although the role of the QAUs representing the contract facilities and the sponsor both ensure the quality of study conduct, and ultimately the final product, their respective approaches may be from different perspectives. The contract QAU's primary focus is the specific study conduct, including appropriate inspections of ongoing critical phases and audits of raw data and reports, along with compliance to site Standard Operating Procedures (SOPs), protocols and sponsor requirements. On the other hand, sponsor QAUs focus mainly on overall study conduct, assurance that contract QAUs are operating effectively, and ensuring that sponsor monitors are communicating adequately with contract facility personnel. Open communication between the respective QAUs is the most productive and useful way of ensuring that all quality criteria are met.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Protocols↗
PubMedDate not supplied

Nitric oxide production and MDR expression by human brain endothelial cells.

The endothelium both initiates and responds to a cascade of events triggered by cytokines. Enhanced formation of NO, especially by inducible nitric oxide- synthase (i NOS), is largely stimulated by tumor necrosis factor (TNF). Nitrogen oxides are reactive intermediate molecules functioning in neural transmission, and vasodilatation. The aim of our study was to investigate the effect of TNF and Staphylococcus aureus, a TNF inducing agent on the NO production of brain endothelial cells in vitro. The effect of the same agent was investigated on the MDR expression of endothelial cells. Both TNF and Staphylococcus aureus resulted in enhanced NO production. Western blot analysis showed enhanced expression of iNOS, which could be inhibited by pentoxifylline, an inhibitor of TNF synthesis. Flow cytometric analysis revealed that the brain capillary endothelial cells exerted P-glycoprotein expression, which was not influenced by TNF. However, the mdr function itself in these cells was decreased by TNF. Cultured endothelial cells are excellent tools for the investigation of the possible connection between the NO production and MDR function, and for the estimation the effect of different agents influencing these activities, which might be important in blood-brain barrier function.

ATP Binding Cassette Transporter, Subfamily B, Mem↗