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J J Stuart

Publications and source records attributed to J J Stuart.

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Chromosome extraction and revision of linkage group 2 in Tribolium castaneum.

We used a balancer chromosome to recover ethylmethanesulfonate-induced recessive mutations in a targeted region of the genome of the red flour beetle (Tribolium castaneum) by the technique of chromosome extraction. The experiments reported herein constitute the first successful application of this powerful technique in the order Coleoptera. Using the balancer chromosome maxillopedia-Dachs3 (mxpDch-3), we recovered seven recessive visible variants representing seven distinct loci and several dozen recessive lethal variants representing at least five distinct loci after screening 1,607 EMS-mutagenized chromosomes. A subset of the mxpDch-3-extracted mutations were positioned on the map of the second linkage group by a series of two-, three-, and four-point crosses. The orientation of the homeotic gene complex (HOM-C) on this linkage group was also determined. With the advent of better and more varied balancer chromosomes and the concomitant improvement of chromosome extraction procedures for genetic analysis of T. castaneum, saturation mutagenesis of targeted regions of the genome is now feasible in this species.

Animals↗

Pharmacokinetics of vincristine infusion.

Using a sensitive radioimmunoassay, serial blood concentrations of vincristine were measured in 11 patients with refractory malignancies receiving infusions of vincristine at three dose levels: 0.5, 0.75, and 1.0 mg/m2 daily for 5 days. The pharmacokinetics of vincristine infusion were compared to pharmacologic data obtained from four patients who received conventional iv bolus injections of 2 mg of vincristine. Whereas rapid decline of blood levels was seen following iv bolus injection, with concentrations of vincristine approaching 10(-9) M by 48-72 hours, vincristine infusions of 0.5, 0.75, and 1.0 mg/m2 daily for 5 days consistently resulted in blood concentrations greater than 10(-9) M during the treatment period. Similarly, areas under the concentration curve were greater in patients receiving infusions compared to bolus injections of vincristine. Antitumor responses in patients receiving vincristine infusions were observed after failure to respond to iv bolus injections. These data demonstrate the ability of infusion therapy to sustain blood concentrations of vincristine in man beyond that seen with conventional administration and suggest the possibility of improved therapeutic efficacy with this agent by use of infusion techniques.

Adult↗