365 research outputs found

    The Norumbega Fault Zone, Maine: a mid-to shallow-level crustal section within a transcurrent shear zone

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    From studies of structure, metamorphism, and geochronology we have evidence that the Norumbega Fault Zone represents a transition from mid- to shallow crustal levels in a dextral, transcurrent shear zone within the northern Appalachian Orogen. The Norumbega Fault Zone strikes parallel to the orogen (northeast-southwest), is ~5 to 30 km wide, and is characterized by distributed ductile dextral shear fabrics in the southwestern section with a transition to brittle fabrics toward the northeast. Within the zone of distributed shear, deformation is partitioned into local zones of very high strain. Upright, isoclinal folds are common in areas of high and low strain. Metamorphic grade decreases from amphibolite facies in the southwest to sub-green schist facies in the northeast. 40Ar/39Ar mineral ages from recrystallized minerals in a high strain zone, regional cooling ages in areas of lower strain, and metamorphic textures are consistent with a polyphase history of deformation. We interpret a younging trend in 40Ar/39Ar cooling ages toward the northeast, together with the deformational fabrics andmetamorphic features, to represent exhumation of the southwestern section of the Norumbega Fault Zone from mid-crustal levels during the polyphase history of this transcurrent zone. The Norumbega Fault Zone may therefore serve as a model for deformational processes at mid- to shallow crustal levels in active strike-slip systems. RÉSUMÉ Des études de la structure, du métamorphisme et de la géochronologic nous fournissent la preuve que la zone faillée de Norumbega représente une transition des niveaux crustaux moyens à des niveaux peu profonds dans une zone de cisaillement transversal dextrale à l'intérieur de la partie septentrionale de l'orogene appalachien. La zone faillée de Norumbega suit une direction paralléle a l'orogéne (nord-est-sud-ouest); die a cinq à 30 km de largeur; et elle est caractérisec par des structures cisaillées dextrales déformables se ramifiant dans la section sud-ouest avec une transition a des structures cassantes vers le nord-est. A l'intérieur de la zone de cisaillement ramifié, la déformation est divisée en zones locales de très forte contrainte. Les plis droits isoclinaux sont courants dans les secteurs de forte et faible contrainte. L'intensité du métamorphisme décroit d'un faciès à amphibolite dans le sud-ouest à un faciès secondaire de schistes verts dans le nord-est. Les périodes minérales 40Ar/39Ar des minéraux recristallises dans une zone de forte contrainte, les périodes de refroidissement régional dans les secteurs de faible contrainte et les textures métamorphiques correspondent à une orogénese polyphasée. Nous interprétons la tendance de rajeunissement dans les périodes de refroidissement 40Ar/39Ar vers le nord-est, de même que les textures de déformation et les caractéristiqucs métamorphiques, comme une exhumation de la section sud-ouest de la zone faillée de Norumbega depuis les niveaux crustaux moyens pendant l'histoire polyphasée de cette zone transversale. La zone faillée de Norumbega pourrait, par consequent, servir de modèle pour les processus de déformation aux niveaux variant de moyens à peu profonds dans les systèmes a décrochement. [Traduit par la rédaction

    Variation in emergency percutaneous coronary intervention in ventilated patients in the UK: insights from a national database

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    Aims Pre-procedural ventilation is a marker of high risk in PCI patients. Causes include out-of-hospital cardiac arrest (OHCA) and cardiogenic shock. OHCA occurs in approximately 60,000 patients in the UK per annum. No consensus exists regarding the need/timing of coronary angiography ± revascularization without ST elevation. The aim was to describe the national variation in the rate of emergency PCI in ventilated patients. Methods and Results Using the UK national database for PCI in 2013, we identified all procedures performed as ‘emergency’ or ‘salvage’ for whom ventilation had been initiated before the PCI. Of the 92,589 patients who underwent PCI, 1342 (5.5%) fulfilled those criteria. There was wide variation in practice. There was no demonstrable relationship between the number of emergency PCI patients with pre-procedure ventilation per annum and (i) total number of PPCIs in a unit (r = −0.186), and (ii) availability of 24 h PCI, (iii) on-site surgical cover. Conclusion We demonstrated a wide variation in practice across the UK in rates of pre-procedural ventilation in emergency PCI. The majority of individuals will have suffered an OHCA. In the absence of a plausible explanation for this discrepant practice, it is possible that (a) some patients presenting with OHCA that may benefit from revascularization are being denied treatment and (b) procedures may be being undertaken that are futile. Further prospective data are needed to aid in production of guidelines aiming at standardized care in OHCA

    Determinants of excess mortality following unprotected left main stem percutaneous coronary intervention.

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    For percutaneous coronary intervention (PCI) to the unprotected left main stem (UPLMS), there are limited long-term outcome data. We evaluated 5-year survival for UPLMS PCI cases taking into account background population mortality.A population-based registry of 10 682 cases of chronic stable angina (CSA), non-ST-segment elevation acute coronary syndrome (NSTEACS), ST-segment elevation myocardial infarction with (STEMI+CS) and without cardiogenic shock (STEMI-CS) who received UPLMS PCI from 2005 to 2014 were matched by age, sex, year of procedure and country to death data for the UK populace of 56.6 million people. Relative survival and excess mortality were estimated.Over 26 105 person-years follow-up, crude 5-year relative survival was 93.8% for CSA, 73.1% for NSTEACS, 77.5% for STEMI-CS and 28.5% for STEMI+CS. The strongest predictor of excess mortality among CSA was renal failure (EMRR 6.73, 95% CI 4.06 to 11.15), and for NSTEACS and STEMI-CS was preprocedural ventilation (6.25, 5.05 to 7.75 and 6.92, 4.25 to 11.26, respectively). For STEMI+CS, the strongest predictor of excess mortality was preprocedural thrombolysis in myocardial infarction (TIMI) 0 flow (2.78, 1.87 to 4.13), whereas multivessel PCI was associated with improved survival (0.74, 0.61 to 0.90).Long-term survival following UPLMS PCI for CSA was high, approached that of the background populace and was significantly predicted by co-morbidity. For NSTEACS and STEMI-CS, the requirement for preprocedural ventilation was the strongest determinant of excess mortality. By contrast, among STEMI+CS, in whom survival was poor, the strongest determinant was preprocedural TIMI flow. Future cardiovascular cohort studies of long-term mortality should consider the impact of non-cardiovascular deaths

    Statin Treatment Increases Lifespan and Improves Cardiac Health in Drosophila by Decreasing Specific Protein Prenylation

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    Statins such as simvastatin are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and standard therapy for the prevention and treatment of cardiovascular diseases in mammals. Here we show that simvastatin significantly increased the mean and maximum lifespan of Drosophila melanogaster (Drosophila) and enhanced cardiac function in aging flies by significantly reducing heart arrhythmias and increasing the contraction proportion of the contraction/relaxation cycle. These results appeared independent of internal changes in ubiquinone or juvenile hormone levels. Rather, they appeared to involve decreased protein prenylation. Simvastatin decreased the membrane association (prenylation) of specific small Ras GTPases in mice. Both farnesyl (L744832) and type 1 geranylgeranyl transferase (GGTI-298) inhibitors increased Drosophila lifespan. These data are the most direct evidence to date that decreased protein prenylation can increase cardiac health and lifespan in any metazoan species, and may explain the pleiotropic (non-cholesterol related) health effects of statins

    Effects of an Extensively Hydrolyzed Formula Supplemented with Two Human Milk Oligosaccharides on Growth, Tolerability, Safety and Infection Risk in Infants with Cow’s Milk Protein Allergy: A Randomized, Multi-Center Trial

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    This randomized clinical trial (Registration: NCT03085134) assessed if an extensively hydrolyzed formula (EHF) supplemented with two human milk oligosaccharides (HMO) and reduced protein content (2.20 g/100 kcal) supports normal growth in infants with cow’s milk protein allergy (CMPA). Secondary outcomes were gastrointestinal tolerability, safety, and effect on infections. Nonbreastfed infants aged 0–6 months with CMPA were enrolled. Body weight, length, and head circumference were measured monthly for 4 months (primary study endpoint), after 6 months, and at the age of 12 months. Of 200 infants screened, 194 (mean age 3.2 months) were randomized. At the 4-month follow-up, daily weight gain for the test formula was noninferior to the control formula; p < 0.005. There were no significant group differences in anthropometric parameters. Both formulas were safe and well tolerated. Infants in the HMO group had a statistically significant reduction in the frequency of upper respiratory tract infections and a lower incidence of ear infections at 12 months (per protocol analysis). The relative risk of lower respiratory tract and gastrointestinal infections was reduced by 30–40%, but this was not statistically significant due to sample size limitations. In summary, the HMO-supplemented formula supports normal growth in infants with CMPA and suggests a protective effect against respiratory and ear infections in the first year of life

    Trajectories of self-rated health in people with diabetes: Associations with functioning in a prospective community sample

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    © 2013 Schmitz et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Self-rated health (SRH) is a single-item measure that is one of the most widely used measures of general health in population health research. Relatively little is known about changes and the trajectories of SRH in people with chronic medical conditions. The aims of the present study were to identify and describe longitudinal trajectories of self-rated health (SRH) status in people with diabetes. Methods: A prospective community study was carried out between 2008 and 2011. SRH was assessed at baseline and yearly at follow-ups (n=1288). Analysis was carried out through trajectory modeling. The trajectory groups were subsequently compared at 4 years follow-up with respect to functioning. Results: Four distinct trajectories of SRH were identified: 1) 72.2% of the participants were assigned to a persistently good SRH trajectory; 2) 10.1% were assigned to a persistently poor SRH trajectory; 3) mean SRH scores changed from good to poor for one group (7.3%); while 4) mean SRH scores changed from poor to medium/good for another group (10.4%). Those with a persistently poor perception of health status were at higher risk for poor functioning at 4 years follow-up than those whose SRH scores decreased from good to poor. Conclusions: SRH is an important predictor for poor functioning in diabetes, but the trajectory of SRH seems to be even more important. Health professionals should pay attention to not only SRH per se, but also changes in SRH over time.This work was supported by Operating Grant MOP-84574 from the Canadian Institutes of Health Research (CIHR). GG was supported by a doctoral fellowship from the CIHR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Impact of Intracoronary Imaging-Guided Percutaneous Coronary Intervention on Procedural Outcomes Among Complex Patient Groups.

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    Background Intracoronary imaging (ICI) has been shown to improve survival after percutaneous coronary intervention (PCI). Whether this prognostic benefit is sustained across different indications remains unclear. Methods and Results All PCI procedures performed in England and Wales between April, 2014 and March 31, 2020, were retrospectively analyzed. The association between ICI use and in-hospital major acute cardiovascular and cerebrovascular events; composite of all-cause mortality, stroke, and reinfarction and mortality was examined using multivariable logistic regression analysis for different imaging-recommended indications as set by European Association for Percutaneous Cardiovascular Interventions consensus. Of 555 398 PCI procedures, 10.8% (n=59 752) were ICI-guided. ICI use doubled between 2014 (7.8%) and 2020 (17.5%) and was highest in left main PCI (41.2%) and lowest in acute coronary syndrome (9%). Only specific European Association for Percutaneous Cardiovascular Interventions imaging-recommended indications were associated with reduced major acute cardiovascular and cerebrovascular events and mortality, including left main PCI (odds ratio [OR], 0.45 [95% CI, 0.39-0.52] and 0.41 [95% CI, 0.35-0.48], respectively), acute coronary syndrome (OR, 0.76 [95% CI, 0.70-0.82] and 0.70 [95% CI, 0.63-0.77]), and stent length >60 mm (OR, 0.75 [95% CI, 0.59-0.94] and 0.72 [95% CI, 0.54-0.95]). Stent thrombosis and renal failure were associated with lower mortality (OR, 0.69 [95% CI, 0.52-0.91]) and major acute cardiovascular and cerebrovascular events (OR, 0.77 [95% CI, 0.60-0.99]), respectively. Conclusions ICI use has more than doubled over a 7-year period at a national level but remains low, with <1 in 5 procedures performed under ICI guidance. In-hospital survival was better with ICI-guided than angiography-guided PCI, albeit only for specific indications
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