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Biomedical subjects

L J Thomas

Publications and source records attributed to L J Thomas.

2 recordsLinked to original sources

A sensitive and reproducible assay for the quantitation of erythrophagocytosis and its correlation with reduction in tritiated thymidine uptake in a tumor target cell system modified by immunoenhancing or immunosuppressive agents.

A new and sensitive assay procedure for studying erythrophagocytosis is described. The assay technique permits quantitation of the in vivo and in vitro effects of chemicals, hormones, and cell, or microbrial products, on the level of phagocytic activation of glass-adherent cells. The effect of intraperitoneal injection of BCG, Zymosan, Vitamin A, B. pertussis, cortisone, estrone, and thioglycollate on phagocytic activation of peritoneal exudate cells harvested from two days up to 28 days following drug injection was examined by this assay. Erythrophagocytosis was compared to the effect of "activated" spleen cells on tritiated thymidine uptake of a tumor target cell suspension.

Animals

A detection algorithm for multiform premature ventricular contractions.

This paper reports an algorithm developed to identify and quantify multiform PVCs. The algorithm clusters PVCs of similar morphology using a combination of time-domain and frequency-domain analysis. Initially, PVCs are grouped together on the basis of four time-domain-based morphological feature measurements. However, these time-domain-based clusters many times are nonunique because commonly encountered signal changes can cause substantial variations in the feature measurements of clinically similar beats. These redundant clusters are consolidated using two frequency-domain parameters: The First Spectral Moment (FSM) (center of gravity) of the amplitude spectrum, and the 5-Hz phase angle.

Cardiac Complexes, Premature