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Biomedical subjects

J W Larrick

Publications and source records attributed to J W Larrick.

136 records · Page 8Linked to original sources
PubMed1979

Transferrin receptors on human B and T lymphoblastoid cell lines.

Experiments demonstrating the existence of receptors for iron-saturated transferrin on both B and T lymphoblastoid cell lines of human origin are described. Binding of 125I-labeled transferrin is rapid, saturable and reversible. It can be specifically inhibited by unlabeled transferrin but not by other proteins. The number of receptors on T cell lines determined by Scatchard analysis is almost double the number on B cell lines but the binding affinities are equal. The putative transferrin receptor can be removed from the cell by the proteolytic enzymes papain and trypsin, and is re-expressed during overnight incubation at 37 degrees C. Resynthesis is inhibited by puromycin. The receptor can be solubilized by deoxycholate, and retains transferrin binding capacity when non-covalently attached to an amphipathic matrix consisting of deoxycholate-coupled poly(L-lysyl) Agarose.

B-Lymphocytes↗
PubMed1979

Modulation of cell surface iron transferrin receptors by cellular density and state of activation.

This report describes investigations of plasma membrane transferring receptors on a variety of lymphoid cell lines and normal peripheral blood lymphocytes during activation and cell growth cycles. Transformed lymphoid cell lines have as many as 1,000 times the number of receptors found on normal resting lymphocytes. The number of iron transferrin receptors on continuous cell lines as well as normal human fibroblasts is down-regulated during the transition from log-phase growth to stationary plateau growth. When normal lymphocytes are transformed by mixed lymphocyte culture or mitogens, they rapidly express a 50-fold increase in the number of transferrin binding sites. This appearance of iron transferrin receptors anticipates nuclear changes during cell activation and subsequent mitosis of normal cells.

Cell Cycle↗
PubMedDate not supplied

Production of antibodies in transgenic plants.

Plants offer a cost-effective bioreactor to produce antibodies of diverse types. Recent studies demonstrate that secretory IgA, the predominant antibody isotype of the mucosal immune system, can be made in large quantities in plants. CaroRx, the lead SIgA antibody being developed by Planet Biotechnology Inc., has demonstrated activity in pilot phase II trials versus S. mutans, the major pathogen contributing to development of dental caries. Numerous other SIgA plantibodies are in preclinical development.

Antibodies, Monoclonal↗
PubMedDate not supplied

Clinical trial of a plant-derived antibody on recolonization of mutans streptococci.

OBJECTIVE: This double-blinded, placebo-controlled clinical trial tested the safety and efficacy of a topical secretory IgA antibody manufactured in tobacco plants (plantibody) in preventing recolonization of mutans streptococci (MS) in human plaque as measured by whole stimulated saliva samples. METHODS: Following a 9-day antimicrobial treatment with chlorhexidine (CHX), 56 eligible adults (enrollment salivary MS > or = 10(4) CFU/ml; no current caries) were randomized equally to a group receiving 0, 2, 4, or 6 topical applications of plantibody followed by 6, 4, 2, or 0 applications of placebo, respectively, over a 3-week period. RESULTS: Among the 54 subjects who completed the trial, the CHX regimen eliminated salivary MS in 69%. After 6 months, there were no significant differences in MS levels by number of applications, relative to placebo (p > 0.43). No adverse effects were observed. CONCLUSION: Plantibody is safe but not effective at the frequency, concentration, and number of applications used in this study.

Adult↗
PubMedDate not supplied

Message amplification phenotyping (MAPPing): a technique to simultaneously measure multiple mRNAs from small numbers of cells.

A rapid and highly sensitive technique (MAPPing: message amplification phenotyping) has been developed to simultaneously analyze the array of messenger RNAs made by small numbers of cells. The technique incorporates a micro-procedure for isolating RNA, reverse transcription of total cellular RNA to produce cDNA, and enzymatic amplification of cytokine-specific DNA fragments using the polymerase chain reaction. In this study, the technique has been applied to the analysis of cytokines produced by lymphoid cells ranging in number from a single cell to 10(6) cells. The technique should be applicable to virtually any tissue or cell type.

Base Sequence↗