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Biomedical subjects

M Keeney

Publications and source records attributed to M Keeney.

64 records · Page 4Linked to original sources
PubMed1966

Quantitative micro determination and isolation of plasmalogen aldehydes as 2,4-dinitrophenylhydrazones.

A micro spectrophotometric procedure for the quantitative determination of plasmalogen aldehydes is described which utilizes simultaneous methanolysis and formation of 2,4-dinitrophenylhydrazones. After isolation of the hydrazones by thin-layer chromatography, the aldehydes can be regenerated, reduced, acetylated, and then analyzed by gas-liquid chromatography. Identification of the plasmalogen aldehydes obtained from rumen holotrich protozoa is described.

Aldehydes↗
PubMedDate not supplied

Flow cytometric enumeration and immunophenotyping of hematopoietic stem and progenitor cells.

Flow cytometric enumeration of CD34+ hematopoietic stem and progenitor cells (HPC) is widely used for evaluation of graft adequacy of peripheral blood stem cell grafts, and is also useful in planning the apheresis sessions necessary to obtain these grafts. The state-of-the-art method to enumerate CD34+ cells makes use of a multiparameter definition of HPC based on their light scatter characteristics and dim expression of CD45, and the use of counting beads to derive the concentration of CD34+ cells directly from the flow cytometric assessment. This method can be extended with a viability stain and additional markers for further immunological characterization of CD34+ cells, and has been successfully implemented in multicenter trials. Thus, the lower threshold of a safe HPC graft in terms of short- and long-term hematopoiesis may be more accurately defined.

Animals↗
PubMedDate not supplied

Impact of standardization on clinical cell analysis by flow cytometry.

The evolution of flow cytometry from a research tool to a pivotal technology for clinical diagnostic purposes has required significant efforts to standardize methods. The great advantage of flow cytometry is that it's applications are highly amenable to standardization. Here, we review the efforts that have been made for flow cytometric applications in four major fields of clinical cell analysis: CD4+ T-cell enumeration, CD34+ hematopoietic stem and progenitor cell enumeration, screening for the HLA-B27 antigen and leukemia/lymphoma immunophenotyping. These standardization efforts have been parallelled by the establishment of external quality assessment (EQA) schemes in many countries worldwide. The goal of these EQA exercises has been primarily educa-tional, but their results will increasingly serve as a basis for laboratory accreditation. This important development requires that the EQA schemes, in particular the quality of the distributed samples and the procedures for evaluating the results, meet the highest standards.

Antigens, CD34↗