Duane D. Miller

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Studies have been conducted on the dynamics of Ca2+ entry in pollen tubes using ratiometric ion imaging to measure the intracellular gradient and an ion selective vibrating electrode to detect the extracellular influx. A steep tip-focused gradient occurs in all species examined, including Lilium longiflorum, Nicotiana sylvestris, and Tradescantia(More)
Lily pollen tubes possess a steep, tip-focused intracellular Ca2+ gradient and a tip-directed extracellular Ca2+ influx. Ratiometric ion imaging revealed that the gradient extends from above 3.0 microM at the apex to approximately 0.2 microM within 20 microns from the tip, while application of the Ca(2+)-specific vibrating electrode indicated that the(More)
We have adapted an in vitro digestion/Caco-2 cell model to assess Fe availability from foods, by using ferritin formation by Caco-2 cells as an indicator of Fe uptake. Ferritin formation by Caco-2 cells occurs in response to Fe uptake at concentrations of available Fe greater than that of the culture media to which the cells have been adapted. This(More)
The presence and localization of actin and myosin have been examined in pollen tubes of Lilium longiflorum and Nicotiana alata. Immunoblot analysis of pollen tube extracts with antibodies to actin, myosins IA and IB, myosin II, and myosin V reveals the presence of these contractile proteins. Immunofluorescence microscopy using various methods to preserve(More)
Nonsteroidal androgens have not been reported. During studies to identify affinity ligands for the androgen receptor in our laboratory, we synthesized several electrophilic nonsteroidal ligands for the androgen receptor and examined their receptor binding affinity and ability to stimulate receptor-mediated transcriptional activation. We found that three of(More)
The purpose of this study was to determine the role of alpha-amino-3-hydroxy- 5-methylisoxazole-4-propionate (AMPA)/kainate excitatory amino acid receptors in the nucleus accumbens and the ventral pallidum in the hypermotility responses to amphetamine, caffeine and scopolamine. To accomplish this, we determined the effects of intracranial injections of(More)
Cryofixation is widely held to be superior to chemical fixation for preserving cell structure; however, the use of cryofixation has been limited chiefly to electron microscopy. To see if cryofixation would improve sample structure or antigenicity as observed through the light microscope, we cryofixed Nicotiana alata and Lilium longiflorum pollen tubes and(More)
An in vitro method for estimating food iron availability is described. The method involves simulated gastrointestinal digestion followed by measurement of soluble, low molecular weight iron. Mixtures of foods (meals) were homogenized and exposed to pepsin at pH 2. Dialysis was used to adjust the pH to intestinal levels and digestion was continued after the(More)
Prostate cancer cell migration is an essential event both in the progression of prostate cancer and in the steps leading to metastasis. We report here that lysophosphatidic acid (LPA), a potent bioactive phospholipid, induces prostate cancer PC3 cell migration via the activation of the LPA(1) receptor, which is linked to a PTX-sensitive activation mechanism(More)
Inulin, a linear beta fructan, is present in a variety of plants including chicory root and wheat. It exhibits prebiotic properties and has been shown to enhance mineral absorption and increase beneficial bacteria in the colon. The aim of the present study was to assess the effect of dietary inulin on the gene expression of selected intestinal Fe(More)