The Causes of Minor Suicide: How the Restatement Approach to Foreseeability & Scope of Liability Fails to Act as a Deterrent.

Suicide is one of the most common causes of death among individuals younger than eighteen years old. While psychological and social sciences continue to study the causes of the increasing prevalence of suicide in children and teens, the law largely continues to treat suicide as an isolated event. This Note tracks the historical treatment of suicide both under tort and criminal law, supporting the shift away from the traditional view of suicide towards one that more closely aligns with the growing understanding of the many factors that can contribute to a minor's suicide. Ultimately, this Note argues that many minor suicides should be treated as foreseeable, allowing actions in tort.

The XFP (17-BM) beamline for X-ray footprinting at NSLS-II.

Hydroxyl-radical mediated synchrotron X-ray footprinting (XF) is a powerful solution-state technique in structural biology for the study of macromolecular structure and dynamics of proteins and nucleic acids, with several synchrotron resources available to serve the XF community worldwide. The XFP (Biological X-ray Footprinting) beamline at the NSLS-II was constructed on a three-pole wiggler source at 17-BM to serve as the premier beamline for performing this technique, providing an unparalleled combination of high flux density broadband beam, flexibility in beam morphology, and sample handling capabilities specifically designed for XF experiments. The details of beamline design, beam measurements, and science commissioning results for a standard protein using the two distinct XFP endstations are presented here. XFP took first light in 2016 and is now available for general user operations through peer-reviewed proposals. Currently, beam sizes from 450 µm × 120 µm to 2.7 mm × 2.7 mm (FWHM) are available, with a flux of 1.6 × 1016 photons s-1 (measured at 325 mA ring current) in a broadband (∼5-16 keV) beam. This flux is expected to rise to 2.5 × 1016 photons s-1 at the full NSLS-II design current of 500 mA, providing an incident power density of >500 W mm-2 at full focus.

Characterization of metalloproteins by high-throughput X-ray absorption spectroscopy.

High-throughput X-ray absorption spectroscopy was used to measure transition metal content based on quantitative detection of X-ray fluorescence signals for 3879 purified proteins from several hundred different protein families generated by the New York SGX Research Center for Structural Genomics. Approximately 9% of the proteins analyzed showed the presence of transition metal atoms (Zn, Cu, Ni, Co, Fe, or Mn) in stoichiometric amounts. The method is highly automated and highly reliable based on comparison of the results to crystal structure data derived from the same protein set. To leverage the experimental metalloprotein annotations, we used a sequence-based de novo prediction method, MetalDetector, to identify Cys and His residues that bind to transition metals for the redundancy reduced subset of 2411 sequences sharing <70% sequence identity and having at least one His or Cys. As the HT-XAS identifies metal type and protein binding, while the bioinformatics analysis identifies metal- binding residues, the results were combined to identify putative metal-binding sites in the proteins and their associated families. We explored the combination of this data with homology models to generate detailed structure models of metal-binding sites for representative proteins. Finally, we used extended X-ray absorption fine structure data from two of the purified Zn metalloproteins to validate predicted metalloprotein binding site structures. This combination of experimental and bioinformatics approaches provides comprehensive active site analysis on the genome scale for metalloproteins as a class, revealing new insights into metalloprotein structure and function.

Human-induced pluripotent stem cell-derived cardiomyocytes exhibit temporal changes in phenotype.

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) have been recently derived and are used for basic research, cardiotoxicity assessment, and phenotypic screening. However, the hiPS-CM phenotype is dependent on their derivation, age, and culture conditions, and there is disagreement as to what constitutes a functional hiPS-CM. The aim of the present study is to characterize the temporal changes in hiPS-CM phenotype by examining five determinants of cardiomyocyte function: gene expression, ion channel functionality, calcium cycling, metabolic activity, and responsiveness to cardioactive compounds. Based on both gene expression and electrophysiological properties, at day 30 of differentiation, hiPS-CMs are immature cells that, with time in culture, progressively develop a more mature phenotype without signs of dedifferentiation. This phenotype is characterized by adult-like gene expression patterns, action potentials exhibiting ventricular atrial and nodal properties, coordinated calcium cycling and beating, suggesting the formation of a functional syncytium. Pharmacological responses to pathological (endothelin-1), physiological (IGF-1), and autonomic (isoproterenol) stimuli similar to those characteristic of isolated adult cardiac myocytes are present in maturing hiPS-CMs. In addition, thyroid hormone treatment of hiPS-CMs attenuated the fetal gene expression in favor of a more adult-like pattern. Overall, hiPS-CMs progressively acquire functionality when maintained in culture for a prolonged period of time. The description of this evolving phenotype helps to identify optimal use of hiPS-CMs for a range of research applications.

Structure and property based design of factor Xa inhibitors: pyrrolidin-2-ones with aminoindane and phenylpyrrolidine P4 motifs.

The rational design, syntheses and evaluation of potent sulfonamidopyrrolidin-2-one-based factor Xa inhibitors incorporating aminoindane and phenylpyrrolidine P4 motifs are described. These series delivered highly potent anticoagulant compounds with excellent oral pharmacokinetic profiles; however, significant time dependant P450 inhibition was an issue for the aminoindane series, but this was not observed with the phenylpyrrolidine motif, which produced candidate quality molecules with potential for once-daily oral dosing in humans.

The discovery of potent and long-acting oral factor Xa inhibitors with tetrahydroisoquinoline and benzazepine P4 motifs.

The discovery and evaluation of potent and long-acting oral sulfonamidopyrrolidin-2-one factor Xa inhibitors with tetrahydroisoquinoline and benzazepine P4 motifs are described. Unexpected selectivity issues versus tissue plasminogen activator in the former series were addressed in the later, delivering a robust candidate for progression towards clinical studies.

High FGF23 Levels Failed to Predict Cardiac Hypertrophy in Animal Models of Hyperphosphatemia and Chronic Renal Failure.

Increased fibroblast growth factor 23 (FGF23) levels are an independent predictor for adverse cardiac events suggesting a role as a link that drives cardiomyopathic changes in cardiorenal syndrome. The search for the underlying mechanism driving this interaction has led to the hypothesis that FGF23 causes pathogenic changes in the heart. Increased serum FGF23 has been independently shown to cause increased cardiac morbidity, mortality, and hypertrophy by signalling through FGF receptor 4. This mechanistic concept was based on preclinical studies demonstrating inhibition of FGF23 signaling through FGF4, which led to suppression of left ventricular hypertrophy and fibrosis in a 2-week rat 5/6 nephrectomy study and a 12-week (2%) high-phosphate diet mouse model in which FGF23 levels were markedly elevated. In this report, renal dysfunction was observed in the 5/6 nephrectomy model, and FGF23 levels were significantly elevated, whereas no changes in left ventricular hypertrophy were observed at 2 or 4 weeks postnephrectomy. Mice placed on a high-phosphate diet that did not cause significant renal dysfunction resulted in significantly elevated FGF23 but no changes in left ventricular hypertrophy. The in vivo studies reported here, which were performed to recapitulate the observations of FGF23 as a driver of cardiac hypertrophy, did not lend support to the FGF23-driven cardiac remodelling hypothesis.

Structure and property based design of factor Xa inhibitors: pyrrolidin-2-ones with monoaryl P4 motifs.

Structure and property based drug design was exploited in the synthesis of sulfonamidopyrrolidin-2-one-based factor Xa inhibitors, incorporating neutral and basic monoaryl P4 groups, ultimately producing potent inhibitors with effective levels of anticoagulant activity and extended oral pharmacokinetic profiles. However, time dependant inhibition of Cytochrome P450 3A4 was a particular issue with this series.

Automatic identification of relevant chemical compounds from patents.

In commercial research and development projects, public disclosure of new chemical compounds often takes place in patents. Only a small proportion of these compounds are published in journals, usually a few years after the patent. Patent authorities make available the patents but do not provide systematic continuous chemical annotations. Content databases such as Elsevier's Reaxys provide such services mostly based on manual excerptions, which are time-consuming and costly. Automatic text-mining approaches help overcome some of the limitations of the manual process. Different text-mining approaches exist to extract chemical entities from patents. The majority of them have been developed using sub-sections of patent documents and focus on mentions of compounds. Less attention has been given to relevancy of a compound in a patent. Relevancy of a compound to a patent is based on the patent's context. A relevant compound plays a major role within a patent. Identification of relevant compounds reduces the size of the extracted data and improves the usefulness of patent resources (e.g. supports identifying the main compounds). Annotators of databases like Reaxys only annotate relevant compounds. In this study, we design an automated system that extracts chemical entities from patents and classifies their relevance. The gold-standard set contained 18 789 chemical entity annotations. Of these, 10% were relevant compounds, 88% were irrelevant and 2% were equivocal. Our compound recognition system was based on proprietary tools. The performance (F-score) of the system on compound recognition was 84% on the development set and 86% on the test set. The relevancy classification system had an F-score of 86% on the development set and 82% on the test set. Our system can extract chemical compounds from patents and classify their relevance with high performance. This enables the extension of the Reaxys database by means of automation.

Antithrombotic potential of GW813893: a novel, orally active, active-site directed factor Xa inhibitor.

BACKGROUND: Factor Xa (FXa) has been a target of considerable interest for drug development efforts aimed at suppressing thrombosis. In this report, a new orally active, small molecule, active-site directed FXa inhibitor, GW813893, has been profiled in a succession of in vitro and in vivo assays involved in its preclinical characterization as a potential antithrombotic therapeutic. METHODS: In vitro profiling of GW813893 consisted of assessing its inhibitory potential against FXa and a broad panel of related and unrelated enzymes and receptors. Additionally, the FXa inhibition potential of GW813893 was assessed in prothrombinase and plasma-based clotting assays. In vivo characterization of GW813893 consisted of thrombosis studies in a rat inferior vena cava model, a rat carotid artery thrombosis model, and a rabbit jugular thrombosis model. Bleeding studies were conducted in a rat tail transection model. Ex vivo determinations of compound effects on FX and clotting activity were also undertaken. RESULTS: GW813893 was more than 90-fold selective over all enzymes tested, and it inhibited FXa and prothrombinase activity with a Ki of 4.0 nM and 9.7 nM, respectively. In vivo, GW813893 concentration-dependently suppressed thrombotic activity in all models tested. The antithrombotic activity correlated with the suppression of plasma-based clotting activity and the inhibition of plasma FX activity (P < 0.02). Over the antithrombotic dose-range, an increased bleeding diathesis was not observed. CONCLUSION: These experiments demonstrate that GW813893 is a potent, selective, orally active inhibitor of FXa. The data suggest that GW813893 has robust antithrombotic potential at doses that have no detectable hemostasis liability. Collectively, the profile suggests that GW813893 has the preclinical pharmacology underpinnings of an oral antithrombotic therapeutic.

Structure and property based design of factor Xa inhibitors: biaryl pyrrolidin-2-ones incorporating basic heterocyclic motifs.

Structure and property based drug design was exploited in the synthesis of sulfonamidopyrrolidin-2-one-based factor Xa (fXa) inhibitors, incorporating basic biaryl P4 groups, producing highly potent inhibitors with significant anticoagulant activities and encouraging oral pharmacokinetic profiles.

Structure and property based design of factor Xa inhibitors: pyrrolidin-2-ones with biaryl P4 motifs.

Structure and property based drug design was exploited in the synthesis of sulfonamidopyrrolidin-2-one-based factor Xa (fXa) inhibitors, incorporating biaryl P4 groups, producing highly potent inhibitors with encouraging oral pharmacokinetic profiles and significant but sub-optimal anticoagulant activities.

Installation and testing of a focusing mirror at beamline X28C for high flux x-ray radiolysis of biological macromolecules.

The NSLS X28C white-light beamline has been upgraded with a focusing mirror in order to provide increased x-ray density and a wide selection of beam shapes at the sample position. The cylindrical single crystal silicon mirror uses an Indalloy 51 liquid support bath as both a mechanism for heat transfer and a buoyant support to counter the effects of gravity and correct for minor parabolic slope errors. Calorimetric measurements were performed to verify that the calculated more than 200-fold increase in flux density is delivered by the mirror at the smallest beam spot. The properties of the focused beam relevant to radiolytic footprinting, namely, the physical dimensions of the beam, the effective hydroxyl radical dose delivered to the sample, and sample heating upon irradiation, have been studied at several mirror angles.

Factor Xa inhibitors: S1 binding interactions of a series of N-{(3S)-1-[(1S)-1-methyl-2-morpholin-4-yl-2-oxoethyl]-2-oxopyrrolidin-3-yl}sulfonamides.

Factor Xa inhibitory activities for a series of N-{(3S)-1-[(1S)-1-methyl-2-morpholin-4-yl-2-oxoethyl]-2-oxopyrrolidin-3-yl}sulfonamides with different P1 groups are described. These data provide insight into binding interactions within the S1 primary specificity pocket; rationales are presented for the derived SAR on the basis of electronic interactions through crystal structures of fXa-ligand complexes and molecular modeling studies. A good correlation between in vitro anticoagulant activities with lipophilicity and the extent of human serum albumin binding is observed within this series of potent fXa inhibitors. Pharmacokinetic profiles in rat and dog, together with selectivity over other trypsin-like serine proteases, identified 1f as a candidate for further evaluation.

Inhibition of factor IX(a) is protective in a rat model of thromboembolic stroke.

BACKGROUND AND PURPOSE: Although used clinically to prevent stroke, there are few examples of anticoagulant investigations in the treatment of acute thromboembolic stroke in animal models. The treatment of thromboembolic stroke in experimental models has been investigated almost exclusively around the use of tissue plasminogen activator (tPA). In this study, using a rat thromboembolic stroke model, we investigated the use of an inhibitory anti-factor IX(a) monoclonal antibody (SB 249417) for the treatment of thromboembolic stroke and compared its efficacy to that of tPA. METHODS: Stroke was initiated by delivering 6 clots into the internal carotid artery. After 2, 4, or 6 hours, rats received either intravenous vehicle, 10.0 mg/kg tPA, or 1.0, 2.0, or 3.0 mg/kg SB 249417. At 24 hours after stroke, infarct volumes and neurological deficits were assessed. RESULTS: Treatment with tPA 2, 4, or 6 hours after stroke reduced infarct volumes by 35% (P=NS), 45%, and 39%, respectively. tPA treatment did not improve neurological deficits at any time point. Treatment with SB 249417 (3.0 mg/kg) 2, 4, or 6 hours after stroke reduced infarct volumes by 44%, 50%, and 13% (P=NS), respectively. Neurological deficits were reduced by 49%, 42%, and 13% (P=NS), respectively. Neither mortality nor hemorrhage was affected by either treatment. CONCLUSIONS: The data indicate that the inhibition of factor IX(a) within 4 hours of thromboembolic stroke produced a more favorable outcome than tPA. When treatment was initiated 6 hours after stroke, the benefits of factor IX(a) inhibition were lost, whereas tPA continued to suppress lesion development, albeit without a corresponding improvement in functional deficits. This study suggests that cerebral ischemia and the resultant perfusion deficit are exacerbated by the activation of blood coagulation and that anticoagulants like SB 249417 may find utility in the treatment of ischemic stroke.

The antithrombotic efficacy of lotrafiban (SB 214857) in canine models of acute coronary thrombosis.

In patients with acute coronary syndromes, inhibition of platelet aggregation with parenteral alpha(IIb)/beta(III) antagonists has proven effective at preventing nonfatal myocardial infarction and repeat percutaneous coronary interventions. Paradoxically, the efficacy observed for acute indications and parenteral agents has not extended to oral agents and chronic prevention of secondary thrombotic events, despite robust antithrombotic properties in preclinical thrombosis models. This report documents the preclinical data of Lotrafiban, an oral alpha(IIb)/beta(III) antagonist that recently failed in a phase III clinical trial (BRAVO) for the prevention of secondary thrombosis. Lotrafiban was characterized in a dog circumflex artery electrical injury model, and a cyclic flow reduction model ("Folts"). The data demonstrate that both oral (1.0-50.0 mg/kg) and intravenous (0.1-0.8ug/kg/min) administration of lotrafiban produced dose-related inhibition (45%-95%) of ex vivo platelet aggregation. In the electrical injury model, the dose-related inhibition correlated with a significant reduction in the frequency of coronary occlusion, size of the developing thrombus, and the extent of left ventricular ischemic damage. Effects on blood flow and bleeding time were also dose related. The combination of low dose lotrafiban (0.1ug/kg/min) and aspirin (5.0 mg/kg) generated additive antithrombotic effects, approximating the antithrombotic efficacy of a 2-4 fold higher dose of lotrafiban while only modestly prolonging the bleeding time. For purposes of comparison, the ADP receptor antagonist clopidogrel was also assessed in the electrical injury model. Clopidogrel (5.0-10.0 mg/kg, iv.) significantly reduced the resulting left ventricular infarct areas, but lacked the overall efficacy of lotrafiban. In the "Folts" model, lotrafiban inhibited cyclic blood flow reductions (CFR's) by 100% in animals insensitive to the antithrombotic effects of aspirin. Overall, the preclinical data demonstrated that alpha(IIb)/beta(III) antagonism with lotrafiban was a well tolerated and effective strategy for attenuating acute arterial thrombosis. The lack of a correlation between these preclinical data and the outcome of the clinical trial BRAVO are unexplained. However, the combined evidence suggests that these acute canine thrombosis studies may not completely capture the pathology reflected in chronic human atherothrombotic disease.

Healthy aging is associated with increased neural processing of positive valence but attenuated processing of emotional arousal: an fMRI study.

Arousal and valence play key roles in emotional perception, with normal aging leading to changes in the neural substrates supporting valence processing. The objective of this study was to investigate normal age-related changes in the neural substrates of emotional arousal processing. Twenty-three young and 23 older, healthy women underwent functional magnetic resonance imaging as they viewed images which were neutral or positive in valence and which varied in arousal level from low to high. Using a parametric modulation approach, we examined how the blood oxygen-level dependent signal varied with single trial subjective ratings of valence and arousal, and whether this differed with age. In accordance with previous studies we found that the older group showed greater activation in response to positive valence, in the left amygdala, left middle temporal gyrus and right lingual gyrus. In contrast however, they showed reduced reactivity to emotional arousal, in occipital and temporal visual cortices bilaterally, the left inferior parietal cortex, and the supplementary motor area bilaterally. This study represents the first of its kind to clearly dissociate how aging affects the neural correlates of emotional arousal and valence. The changes in arousal processing may in part be mediated by the functional reorganization evident in the aging brain, such as reduced activation of the posterior cortices as described by the posterior-anterior shift in ageing (PASA) effect.

Personality modulates the effects of emotional arousal and valence on brain activation.

The influence of personality on the neural correlates of emotional processing is still not well characterized. We investigated the relationship between extraversion and neuroticism and emotional perception using functional magnetic resonance imaging (fMRI) in a group of 23 young, healthy women. Using a parametric modulation approach, we examined how the blood oxygenation level dependent (BOLD) signal varied with the participants' ratings of arousal and valence, and whether levels of extraversion and neuroticism were related to these modulations. In particular, we wished to test Eysenck's biological theory of personality, which links high extraversion to lower levels of reticulothalamic-cortical arousal, and neuroticism to increased reactivity of the limbic system and stronger reactions to emotional arousal. Individuals high in neuroticism demonstrated reduced sustained activation in the orbitofrontal cortex (OFC) and attenuated valence processing in the right temporal lobe while viewing emotional images, but an increased BOLD response to emotional arousal in the right medial prefrontal cortex (mPFC). These results support Eysenck's theory, as well as our hypothesis that high levels of neuroticism are associated with attenuated reward processing. Extraversion was inversely related to arousal processing in the right cerebellum, but positively associated with arousal processing in the right insula, indicating that the relationship between extraversion and arousal is not as simple as that proposed by Eysenck.

An orally active TRPV4 channel blocker prevents and resolves pulmonary edema induced by heart failure.

Pulmonary edema resulting from high pulmonary venous pressure (PVP) is a major cause of morbidity and mortality in heart failure (HF) patients, but current treatment options demonstrate substantial limitations. Recent evidence from rodent lungs suggests that PVP-induced edema is driven by activation of pulmonary capillary endothelial transient receptor potential vanilloid 4 (TRPV4) channels. To examine the therapeutic potential of this mechanism, we evaluated TRPV4 expression in human congestive HF lungs and developed small-molecule TRPV4 channel blockers for testing in animal models of HF. TRPV4 immunolabeling of human lung sections demonstrated expression of TRPV4 in the pulmonary vasculature that was enhanced in sections from HF patients compared to controls. GSK2193874 was identified as a selective, orally active TRPV4 blocker that inhibits Ca(2+) influx through recombinant TRPV4 channels and native endothelial TRPV4 currents. In isolated rodent and canine lungs, TRPV4 blockade prevented the increased vascular permeability and resultant pulmonary edema associated with elevated PVP. Furthermore, in both acute and chronic HF models, GSK2193874 pretreatment inhibited the formation of pulmonary edema and enhanced arterial oxygenation. Finally, GSK2193874 treatment resolved pulmonary edema already established by myocardial infarction in mice. These findings identify a crucial role for TRPV4 in the formation of HF-induced pulmonary edema and suggest that TRPV4 blockade is a potential therapeutic strategy for HF patients.

Comparative analyses of the small molecule thrombopoietin receptor agonist eltrombopag and thrombopoietin on in vitro platelet function.

OBJECTIVE: The thrombopoietin receptor (TPOR) is a therapeutic target for treatment of thrombocytopenia because stimulation of this receptor results in enhanced megakaryocyte proliferation, differentiation, and ultimately platelet production. In addition to effects on megakaryocytes, TPOR stimulation also impacts platelet function. The present study examined platelet function following stimulation with the small molecule TPOR agonist eltrombopag. MATERIALS AND METHODS: Platelets were obtained from healthy volunteers, and signal transduction pathway activation was examined in washed platelet preparations. Platelet aggregation was examined in both washed platelet preparations and platelet-rich plasma. Platelet alpha-granule release was determined via fluorescein-activated cell sorting measurement of CD62P. RESULTS: In signal transduction studies of washed human platelets, eltrombopag induced the phosphorylation signal transducers and activators of transcription (STAT) proteins with no phosphorylation of Akt, whereas recombinant human TPO (rhTPO) induced the phosphorylation of Akt as well as STAT-1, -3, and -5. In studies conducted at subthreshold/submaximal concentrations of adenosine diphosphate (ADP) or collagen, eltrombopag pretreatment did not result in platelet aggregation. In contrast, rhTPO acted in synergy with submaximal concentrations of ADP or collagen to induce maximal aggregation under all conditions examined. Similarly, platelet activation as examined via surface expression of CD62P was not enhanced by eltrombopag pretreatment as compared to rhTPO. CONCLUSIONS: These results demonstrate that the nonpeptidyl TPOR agonist eltrombopag stimulates platelet signal transduction with little or no effect on overall platelet function, in contrast to TPO, which significantly primes platelet activation. These data demonstrate that effects of TPOR ligands on platelet function can vary depending on the specific mechanism utilized to stimulate the TPOR.