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Biomedical subjects

D Maddox

Publications and source records attributed to D Maddox.

15 recordsLinked to original sources
PubMed1993

Increased tolerance to two oomycete pathogens in transgenic tobacco expressing pathogenesis-related protein 1a.

Expression of pathogenesis-related protein 1a (PR-1a), a protein of unknown biochemical function, is induced to high levels in tobacco in response to pathogen infection. The induction of PR-1a expression is tightly correlated with the onset of systemic acquired resistance (SAR), a defense response effective against a variety of fungal, viral, and bacterial pathogens. While PR-1a has been postulated to be involved in SAR, and is the most highly expressed of the PR proteins, evidence for its role is lacking. In this report, we demonstrate that constitutive high-level expression of PR-1a in transgenic tobacco results in tolerance to infection by two oomycete pathogens, Peronospora tabacina and Phytophthora parasitica var. nicotianae.

Oomycetes↗
PubMed1991

Development of a recombinant baculovirus expressing an insect-selective neurotoxin: potential for pest control.

Recombinant nuclear polyhedrosis viruses (NPVs) expressing insect-selective toxins, hormones, or enzymes could enhance their insecticidal properties. We have constructed a recombinant, polyhedrin-positive Autographa californica NPV (AcNPV) that is orally infectious and expresses an insect-selective toxin (AaIT), isolated from the scorpion Androctonus australis, under the control of the p10 promoter. Bioassays with the recombinant baculovirus on 2nd instar larvae of Heliothis virescens demonstrated a significant decrease in the time to kill (LT50 88.0 hours) compared to wild-type AcNPV (LT50 125 hours). Production of AaIT was confirmed by western blot analysis of larval hemolymph from infected H. virescens, and bioassays with larvae of Sarcophaga falculata.

Animals↗
PubMed1977

Effect of sublingually administered nitroglycerin on regional myocardial blood flow in patients with coronary artery disease.

The effect of sublingually administered nitroglycerin on regional myocardial specific blood flow (in ml/min per 100 g tissue) was evaluated with a xenon-133 washout technique in 31 patients in a resting nonstressed state. Eight patients had normal coronary arteriograms (Group 1), 12 had coronary artery disease without collateral vessels (Group 2) and 11 had coronary artery disease with collateral vessels (Group 3). Although nitroglycerin caused a similar decrease in mean arterial blood pressure and blood pressure-heart rate product in all three groups, the decrease in regional myocardial blood flow was significantly less in Group 3 (-8+/-6% [mean+/-standard error of the mean]) than in Group 1 (-31+/-5%), P less than 0.05); an intermediary decrease occurred in Group 2 (-23+/-5%). Within Group 3, there was a mean increase in regional myocardial blood flow after nitroglycerin in the five patients whose collateral vessels were of a higher angiographic grade and arose from non-stenosed coronary arteries, whereas a reduction was observed in the six patients with none or only one of these findings (+10+/-7% versus -23+/-3%, P less than 0.001). This study suggests that even in the resting state, in some patients with coronary artery disease enhancement of regional myocardial blood flow can occur after sublingual administration of nitroglycerin and is probably mediated through well functioning collateral vessels. It is possible that the drug's effects on both the coronary and systemic circulation may relieve angina in some patients with coronary artery disease.

Administration, Oral↗