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M A Moore

Publications and source records attributed to M A Moore.

527 records · Page 30Linked to original sources

Functionally distinct stages in B-lymphocyte maturation.

Evidence is reviewed that supports the concept of extrinsic stem cell colonization of inductive micro-environments for B-cell formation in the bursa of Fabricius of chickens and foetal liver of mammals. In these organs, the first distinctive marker of B-lineage differentiation (readily detectable immunoglobulin) is synthesized and displayed on cells which have extensive proliferative and differentiative capacity. The degree of commitment of these cells to the synthesis of trace or large quantities of immunoglobulin of the respective major classes when they colonize peripheral lymphoid tissues and the role of antigen in this process are considered.

Animals↗

[Distribution of hematopoietic stem cells in the mononuclear fraction of human umbilical cord blood].

The advances in transplantation of hemopoietic stem cells (HSC) from umbilical human blood (UHB) necessitate introduction of effective methods of HSC isolation and preservation. The studies show that UHB cells remained viable even after several days of storage at room temperature. Density gradients proved effective for isolation of cell precursors from UHB. Most of hemopoietic cell-precursors in UHB have low density (under 1.070 g/ml) which becomes greater with cell maturation.

Blood Cell Count↗

Nonaldehyde sterilization of biologic tissue for use in implantable medical devices.

Biologic tissue stabilized by dye-mediated photooxidation has found application in implantable devices. The desire to avoid aldehydes in the processing of photooxidized tissues led to the development of a nonaldehyde, iodine based sterilant. The interaction of tissue with iodine was indicated by a change in tissue shrinkage temperature, dependent upon solution and incubation parameters. The amino acid tyrosine also was altered, presumably because of aromatic ring iodination. Transmission electron microscopic study indicated no change in the quarter staggered array structure of collagen under controlled iodine treatment conditions. The D10 values for iodine kill of several organisms, in the absence of tissue, were determined in 0.1% iodine (pH 6.5) at 37 degrees C for Bacillus subtilis (12 min, Aspergillus niger, Escherichia coli, Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa (all < 1 min). In a separate experiment, samples of 0.1% iodine (pH 6.5) containing photooxidized pericardial tissue were inoculated with 1.6 X 10(7) Bacillus subtilis, 4.6 X 10(6) Pseudomonas aeruginosa, or 7.2 X 10(6) Staphylococcus aureus and incubated at 37 degrees C. No survivors were detected on the tissue samples after exposure of 48 hr. Photooxidized pericardial tissue samples inoculated with either 3.2 X 10(5) porcine parvovirus or 1 X 10(9) infectious bovine rhinotracheitis were exposed to 0.1% iodine (pH 6.5) at 36 degrees C for 12 h. No viral particles were detected after exposure, yielding minimum viral log reduction factors of 3.0 and 6.5, respectively. The results presented indicate the potential for the nonaldehyde, iodine based solution to sterilize implantable devices containing biologic tissue.

Amino Acids↗