Jurors\u27 Comprehension of Sentencing Instructions: A Test of the Death Penalty Process in Tennessee

In response to the U.S. Supreme Court\u27s mandate in Furman.v. Georgia to constrain jurors\u27 discretion, several states devised sentencing instructions that ostensibly guide jurors\u27 decision making in death penalty cases. Recently, however, jurors\u27 ability to comprehend these sentencing instructions has come under scrutiny. To test jurors\u27 comprehension, we provided 495 persons summoned for jury duty in Shelby County, Tennessee (which includes Memphis) with a copy of Tennessee\u27s death penalty sentencing instructions and asked them to complete a questionnaire. The scenarios in the questionnaire measured comprehension of differences in the levels of proof and requirements for unanimity on the existence of aggravating and mitigating circumstances, of the process of weighing mitigating against aggravating circumstances, and of nonenumerated mitigating circumstances. The results suggest that comprehension is relatively high when the instructions are clear and concise. However, when the instructions are poorly worded or vague, or when serious omissions regarding the law exist, jurors\u27 comprehension is severely limited. Respondents tended not to consider fully mitigating circumstances. Thus, in actual cases in Tennessee, death sentences may have been imposed unconstitutionally

Jurors’ Comprehension of Sentencing Instructions: A Test of the Death Penalty Process in Tennessee

In response to the U.S. Supreme Court’s mandate in Furman v. Georgia to constrain jurors’ discretion, several states devised sentencing instructions that ostensibly guide jurors’ decision making in death penalty cases. Recently, however, jurors’ ability to comprehend these sentencing instructions has come under scrutiny. To test jurors’ comprehension, we provided 495 persons summoned for jury duty in Shelby County, Tennessee (which includes Memphis) with a copy of Tennessee’s death penalty sentencing instructions and asked them to complete a questionnaire. The scenarios in the questionnaire measured comprehension of differences in the levels of proof and requirements for unanimity on the existence of aggravating and mitigating circumstances, of the process of weighing mitigating against aggravating circumstances, and of nonenumerated mitigating circumstances. The results suggest that comprehension is relatively high when the instructions are clear and concise. However, when the instructions are poorly worded or vague, or when serious omissions regarding the law exist, jurors’ comprehension is severely limited. Respondents tended not to consider fully mitigating circumstances. Thus, in actual cases in Tennessee, death sentences may have been imposed unconstitutionally

NPP4 is a procoagulant enzyme on the surface of vascular endothelium

Ap3A is a platelet-dense granule component released into the extracellular space during the second wave of platelet aggregation on activation. Here, we identify an uncharacterized enzyme, nucleotide pyrophosphatase/phosphodiesterase-4 (NPP4), as a potent hydrolase of Ap3A capable of stimulating platelet aggregation and secretion. We demonstrate that NPP4 is present on the surface of vascular endothelium, where it hydrolyzes Ap3A into AMP and ADP, and Ap4A into AMP and ATP. Platelet aggregation assays with citrated platelet-rich plasma reveal that the primary and secondary waves of aggregation and dense granule release are strongly induced by nanomolar NPP4 in a concentration-dependent manner in the presence of Ap3A, while Ap3A alone initiates a primary wave of aggregation followed by rapid disaggregation. NPP2 and an active site NPP4 mutant, neither of which appreciably hydrolyzes Ap3A, have no effect on platelet aggregation and secretion. Finally, by using ADP receptor blockade we confirm that NPP4 mediates platelet aggregation via release of ADP from Ap3A and activation of ADP receptors. Collectively, these studies define the biologic and enzymatic basis for NPP4 and Ap3A activity in platelet aggregation in vitro and suggest that NPP4 promotes hemostasis in vivo by augmenting ADP-mediated platelet aggregation at the site of vascular injury

Time-course of the metabolism of various nucleotides by human normal bronchial cells

<p><b>Copyright information:</b></p><p>Taken from "Structure–activity relationships of dinucleotides: Potent and selective agonists of P2Y receptors"</p><p></p><p>Purinergic Signalling 2005;1(2):183-191.</p><p>Published online Jan 2005</p><p>PMCID:PMC2096529.</p><p></p> The cells were grown to confluence on an air-liquid interface and differentiated into a ciliated cell sheath over 4 weeks. The cells were pre-incubated 30 min at 37°C in Krebs buffer (0.35 ml apical/2 ml basolateral; pH 7.4). The assays were started with 0.1 mM nucleotide added to the apical buffer. Aliquots of 30 µl were transferred to 0.3 ml ice-cold water and boiled during 5 min. Their content in nucleotides was analyzed by HPLC. Data are expressed as percent of initial peak (SEM < 10%; = 4–8)