The Experts below are selected from a list of 1896 Experts worldwide ranked by ideXlab platform
Ruth Hogue Angeletti - One of the best experts on this subject based on the ideXlab platform.
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expression of neuropeptide processing enzymes and neurosecretory Proteins in ependyma and choroid plexus epithelium
Brain Research, 1993Co-Authors: Patricia Gee, Harker C Rhodes, Lloyd D Fricker, Ruth Hogue AngelettiAbstract:Abstract Recent studies suggest that brain ependyma and choroid plexus produce neuropeptide processing enzymes. To facilitate the understanding of these cells and their ability to produce biologically active peptides, we developed cultures of defined cell type. Ependymal cells were characterized by morphological criteria, and choroid plexus epithelial cell lines were characterized by the presence of the mRNA for IGF-II and transthyretin, a Thyroxine Binding Protein produced in liver and choroid plexus. The ependymal cells and the choroid plexus epithelial cell lines were then examined for the presence of mRNAs for various neuropeptide processing enzymes. Northern blot analysis revealed high levels of furin, car☐ypeptidase E, and peptidyl glycine α-amidating monooxygenase mRNAs, with levels in ependymal cells comparable to those in brain or pituitary. Car☐ypeptidase E activity was detected in medium from cultured ependymal cells; this activity was identified as car☐ypeptidase E based on the acidic pH optimum and sensitivity to various inhibitors. The mRNAs for other neuropeptide processing enzymes, such as prohormone convertases 1 and 2, were not detected on Northern blots of RNA from ependyma or choroid plexus epithelium. Since ependyma and choroid plexus epithelium express a subset of processing enzymes, we suggest that these cells have the capacity to produce biologically active peptides. Initial screening by reverse transcriptase-polymerase chain reaction assays has demonstrated the presence of mRNA for the neurosecretory Proteins chromogranin B and secretogranin II in both ependyma and choroid plexus epithelium.
Daniel W Chan - One of the best experts on this subject based on the ideXlab platform.
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the effects of modifying proficiency testing materials on thyroid function test results a college of american pathologists ligand assay survey study
Archives of Pathology & Laboratory Medicine, 1997Co-Authors: Bernard W Steele, David L Witte, Ronald J Whitley, George G Klee, Daniel W ChanAbstract:. Objective.-To gain insight on the matrix effects, and possible clinical implications, resulting from diluting and concentrating proficiency testing survey material used for the measurement of thyroid function tests. Design.-To the standard set of five proficiency survey samples, three supplementary Wildcard samples were added. These additional samples were manufactured by overfilling and underfilling vials prior to lyophilization so as to vary the Thyroxine-Binding Protein concentrations. Survey participants measured Thyroxine, free Thyroxine, and the triiodothyronine uptake and related tests on the Wildcard samples. In addition, free Thyroxine indices were calculated. Setting.-The first mailing of the 1995 College of American Pathologists (CAP) Ligand Assay-Series 1 Survey. Main Outcome Measures.-Results obtained from the regular set of survey samples and the Wildcard set were compared to values expected by the laws of conservation of matter and mass action. Participants.-The approximately 2000 participants of the first mailing of the 1995 CAP Ligand Assay-Series 1 Survey. Results.-Numerous assays systems did not give the predicted results, including all of the single-step radioimmunoassays for free Thyroxine and over three quarters of free Thyroxine index determinations. Conclusions.-Varying the dilution of proficiency survey material produced results that were not predicted by the laws of conservation of matter and of mass action. Although these observations may have been the result of matrix effects, one cannot rule out the possibility that certain thyroid assays may not work in clinical situations having abnormal Thyroxine-Binding Protein concentrations.
Patricia Gee - One of the best experts on this subject based on the ideXlab platform.
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expression of neuropeptide processing enzymes and neurosecretory Proteins in ependyma and choroid plexus epithelium
Brain Research, 1993Co-Authors: Patricia Gee, Harker C Rhodes, Lloyd D Fricker, Ruth Hogue AngelettiAbstract:Abstract Recent studies suggest that brain ependyma and choroid plexus produce neuropeptide processing enzymes. To facilitate the understanding of these cells and their ability to produce biologically active peptides, we developed cultures of defined cell type. Ependymal cells were characterized by morphological criteria, and choroid plexus epithelial cell lines were characterized by the presence of the mRNA for IGF-II and transthyretin, a Thyroxine Binding Protein produced in liver and choroid plexus. The ependymal cells and the choroid plexus epithelial cell lines were then examined for the presence of mRNAs for various neuropeptide processing enzymes. Northern blot analysis revealed high levels of furin, car☐ypeptidase E, and peptidyl glycine α-amidating monooxygenase mRNAs, with levels in ependymal cells comparable to those in brain or pituitary. Car☐ypeptidase E activity was detected in medium from cultured ependymal cells; this activity was identified as car☐ypeptidase E based on the acidic pH optimum and sensitivity to various inhibitors. The mRNAs for other neuropeptide processing enzymes, such as prohormone convertases 1 and 2, were not detected on Northern blots of RNA from ependyma or choroid plexus epithelium. Since ependyma and choroid plexus epithelium express a subset of processing enzymes, we suggest that these cells have the capacity to produce biologically active peptides. Initial screening by reverse transcriptase-polymerase chain reaction assays has demonstrated the presence of mRNA for the neurosecretory Proteins chromogranin B and secretogranin II in both ependyma and choroid plexus epithelium.
Bernard W Steele - One of the best experts on this subject based on the ideXlab platform.
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the effects of modifying proficiency testing materials on thyroid function test results a college of american pathologists ligand assay survey study
Archives of Pathology & Laboratory Medicine, 1997Co-Authors: Bernard W Steele, David L Witte, Ronald J Whitley, George G Klee, Daniel W ChanAbstract:. Objective.-To gain insight on the matrix effects, and possible clinical implications, resulting from diluting and concentrating proficiency testing survey material used for the measurement of thyroid function tests. Design.-To the standard set of five proficiency survey samples, three supplementary Wildcard samples were added. These additional samples were manufactured by overfilling and underfilling vials prior to lyophilization so as to vary the Thyroxine-Binding Protein concentrations. Survey participants measured Thyroxine, free Thyroxine, and the triiodothyronine uptake and related tests on the Wildcard samples. In addition, free Thyroxine indices were calculated. Setting.-The first mailing of the 1995 College of American Pathologists (CAP) Ligand Assay-Series 1 Survey. Main Outcome Measures.-Results obtained from the regular set of survey samples and the Wildcard set were compared to values expected by the laws of conservation of matter and mass action. Participants.-The approximately 2000 participants of the first mailing of the 1995 CAP Ligand Assay-Series 1 Survey. Results.-Numerous assays systems did not give the predicted results, including all of the single-step radioimmunoassays for free Thyroxine and over three quarters of free Thyroxine index determinations. Conclusions.-Varying the dilution of proficiency survey material produced results that were not predicted by the laws of conservation of matter and of mass action. Although these observations may have been the result of matrix effects, one cannot rule out the possibility that certain thyroid assays may not work in clinical situations having abnormal Thyroxine-Binding Protein concentrations.
Lloyd D Fricker - One of the best experts on this subject based on the ideXlab platform.
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expression of neuropeptide processing enzymes and neurosecretory Proteins in ependyma and choroid plexus epithelium
Brain Research, 1993Co-Authors: Patricia Gee, Harker C Rhodes, Lloyd D Fricker, Ruth Hogue AngelettiAbstract:Abstract Recent studies suggest that brain ependyma and choroid plexus produce neuropeptide processing enzymes. To facilitate the understanding of these cells and their ability to produce biologically active peptides, we developed cultures of defined cell type. Ependymal cells were characterized by morphological criteria, and choroid plexus epithelial cell lines were characterized by the presence of the mRNA for IGF-II and transthyretin, a Thyroxine Binding Protein produced in liver and choroid plexus. The ependymal cells and the choroid plexus epithelial cell lines were then examined for the presence of mRNAs for various neuropeptide processing enzymes. Northern blot analysis revealed high levels of furin, car☐ypeptidase E, and peptidyl glycine α-amidating monooxygenase mRNAs, with levels in ependymal cells comparable to those in brain or pituitary. Car☐ypeptidase E activity was detected in medium from cultured ependymal cells; this activity was identified as car☐ypeptidase E based on the acidic pH optimum and sensitivity to various inhibitors. The mRNAs for other neuropeptide processing enzymes, such as prohormone convertases 1 and 2, were not detected on Northern blots of RNA from ependyma or choroid plexus epithelium. Since ependyma and choroid plexus epithelium express a subset of processing enzymes, we suggest that these cells have the capacity to produce biologically active peptides. Initial screening by reverse transcriptase-polymerase chain reaction assays has demonstrated the presence of mRNA for the neurosecretory Proteins chromogranin B and secretogranin II in both ependyma and choroid plexus epithelium.