Stability of tropical forest tree carbon-water relations in a rainfall exclusion treatment through shifts in effective water uptake depth.

Increasing severity and frequency of drought is predicted for large portions of the terrestrial biosphere, with major impacts already documented in wet tropical forests. Using a 4-year rainfall exclusion experiment in the Daintree Rainforest in northeast Australia, we examined canopy tree responses to reduced precipitation and soil water availability by quantifying seasonal changes in plant hydraulic and carbon traits for 11 tree species between control and drought treatments. Even with reduced soil volumetric water content in the upper 1 m of soil in the drought treatment, we found no significant difference between treatments for predawn and midday leaf water potential, photosynthesis, stomatal conductance, foliar stable carbon isotope composition, leaf mass per area, turgor loss point, xylem vessel anatomy, or leaf and stem nonstructural carbohydrates. While empirical measurements of aboveground traits revealed homeostatic maintenance of plant water status and traits in response to reduced soil moisture, modeled belowground dynamics revealed that trees in the drought treatment shifted the depth from which water was acquired to deeper soil layers. These findings reveal that belowground acclimation of tree water uptake depth may buffer tropical rainforests from more severe droughts that may arise in future with climate change.

Hydraulically-vulnerable trees survive on deep-water access during droughts in a tropical forest.

Deep-water access is arguably the most effective, but under-studied, mechanism that plants employ to survive during drought. Vulnerability to embolism and hydraulic safety margins can predict mortality risk at given levels of dehydration, but deep-water access may delay plant dehydration. Here, we tested the role of deep-water access in enabling survival within a diverse tropical forest community in Panama using a novel data-model approach. We inversely estimated the effective rooting depth (ERD, as the average depth of water extraction), for 29 canopy species by linking diameter growth dynamics (1990-2015) to vapor pressure deficit, water potentials in the whole-soil column, and leaf hydraulic vulnerability curves. We validated ERD estimates against existing isotopic data of potential water-access depths. Across species, deeper ERD was associated with higher maximum stem hydraulic conductivity, greater vulnerability to xylem embolism, narrower safety margins, and lower mortality rates during extreme droughts over 35 years (1981-2015) among evergreen species. Species exposure to water stress declined with deeper ERD indicating that trees compensate for water stress-related mortality risk through deep-water access. The role of deep-water access in mitigating mortality of hydraulically-vulnerable trees has important implications for our predictive understanding of forest dynamics under current and future climates.

Drivers and mechanisms of tree mortality in moist tropical forests.

Tree mortality rates appear to be increasing in moist tropical forests (MTFs) with significant carbon cycle consequences. Here, we review the state of knowledge regarding MTF tree mortality, create a conceptual framework with testable hypotheses regarding the drivers, mechanisms and interactions that may underlie increasing MTF mortality rates, and identify the next steps for improved understanding and reduced prediction. Increasing mortality rates are associated with rising temperature and vapor pressure deficit, liana abundance, drought, wind events, fire and, possibly, CO2 fertilization-induced increases in stand thinning or acceleration of trees reaching larger, more vulnerable heights. The majority of these mortality drivers may kill trees in part through carbon starvation and hydraulic failure. The relative importance of each driver is unknown. High species diversity may buffer MTFs against large-scale mortality events, but recent and expected trends in mortality drivers give reason for concern regarding increasing mortality within MTFs. Models of tropical tree mortality are advancing the representation of hydraulics, carbon and demography, but require more empirical knowledge regarding the most common drivers and their subsequent mechanisms. We outline critical datasets and model developments required to test hypotheses regarding the underlying causes of increasing MTF mortality rates, and improve prediction of future mortality under climate change.

Orbital and rotational atherectomy during percutaneous coronary intervention for coronary artery calcification.

Severe coronary artery calcification (CAC) increases the complexity of percutaneous coronary intervention (PCI) by inhibiting optimal stent expansion, leading to an increased risk of death, myocardial infarction, repeat revascularization, and stent thrombosis. Coronary atherectomy modifies and debulks calcified plaque to facilitate PCI. Although there is no clear consensus, and further studies are needed, the decision to perform atherectomy should be based upon the presence of fluoroscopic CAC or with the use of intravascular imaging. The management of CAC in the modern era relies on rotational and orbital atherectomy to prepare the lesion to facilitate stent delivery and optimal expansion. While the two technologies differ in equipment, technique, and mechanism of action, the available literature suggests similar efficacy and safety of the two systems, although head-to-head comparisons are limited. While rotational and orbital atherectomy have been shown to have excellent procedural success in terms of facilitating stent delivery, no system has been shown to reduce long-term major adverse cardiovascular events, although the definitive trial for orbital atherectomy has not been completed. Additional trials are needed to find the population who would derive the most benefit of atherectomy and to compare the two systems in a prospective manner.

Orbital atherectomy for treating de novo, severely calcified coronary lesions: 3-year results of the pivotal ORBIT II trial.

BACKGROUND/PURPOSE: The presence of heavy coronary artery calcification increases the complexity of percutaneous coronary intervention (PCI) and increases the incidence of major adverse cardiac events (MACE): death, myocardial infarction (MI), target vessel revascularization (TVR), and stent thrombosis. The ORBIT II (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) trial reported low rates of procedural, 30-day, 1-year, and 2-year ischemic complications after treatment of de novo, severely calcified lesions with the Diamondback 360° Coronary Orbital Atherectomy System (OAS) (Cardiovascular Systems, Inc.). METHODS/MATERIALS: ORBIT II was a single-arm trial that enrolled 443 patients at 49U.S. sites; in this study, de novo, severely calcified coronary lesions were treated with OAS prior to stenting. The primary safety endpoint was 30-day MACE: the composite of cardiac death, MI, and TVR (inclusive of target lesion revascularization (TLR)). The primary efficacy endpoint was procedural success: stent delivery with a residual stenosis of <50% without the occurrence of in-hospital MACE.The present analysis reports the final, 3-year follow-up results from ORBIT II. RESULTS: The majority of subjects (88.2%) underwent PCI with drug-eluting stents after orbital atherectomy. There were 360 (81.3%) subjects who completed the protocol-mandated 3-year visit.The overall cumulative rate of 3-year MACE was 23.5%, including cardiac death (6.7%), MI (11.2%), and TVR (10.2%). The 3-year target lesion revascularization rate was 7.8%. CONCLUSIONS: In the final 3-year analysis of the ORBIT II trial, orbital atherectomy of severely calcified coronary lesions followed by stenting resulted in a low rate of adverse ischemic events compared with historical controls.Orbital atherectomy represents a safe and effective revascularization strategy for patients with severely calcified coronary lesions. SUMMARY: The ORBIT II trial enrolled 443 subjects to study orbital atherectomy followed by stenting for de novo severely calcified coronary lesions. The overall cumulative 3-year MACE rate was 23.5%, including cardiac death (6.7%), MI (11.2%), and TVR (10.2%); the 3-year target lesion revascularization rate was 7.8%. Orbital atherectomy of heavily calcified coronary lesions followed by stenting results in a low rate of adverse ischemic events compared with historical controls; it represents a reasonable revascularization strategy for patients with severely calcified coronary lesions.

Two-year outcomes after treatment of severely calcified coronary lesions with the orbital atherectomy system and the impact of stent types: Insight from the ORBIT II trial.

OBJECTIVES: We report 2-year outcomes of the Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions (ORBIT II) trial, with emphasis on the impact of stent type. BACKGROUND: The ORBIT II trial demonstrated the safety and efficacy of the Diamondback 360° Coronary Orbital Atherectomy System (OAS; Cardiovascular Systems, Inc., St. Paul, MN) in the treatment of de novo, severely calcified coronary lesions. METHODS: ORBIT II was a single-arm trial that enrolled 443 subjects with severely calcified lesions at 49 US sites. All patients were intended to be treated with OAS before stent implantation. The primary safety endpoint was 30-day major adverse cardiac events (MACE: Cardiac death, myocardial infarction, or target vessel revascularization). For the purpose of this study, we divided patients into three groups according to the type of stent implanted (i.e., bare metal stent [BMS], first-generation drug-eluting stent [DES], or second-generation DES). The 2-year MACE rate and its components were compared between groups. RESULTS: In the ORBIT II study cohort, 2-year rates of MACE, cardiac death, and target vessel revascularization were 19.4%, 4.3%, and 8.1%, respectively. Two year data were available in 419 of 443 patients (94.6%) with median follow up time of 25.1 months. Stent-type data were available in 435 of the 443 patients (98.2%). Six patients received stents of more than one type and were excluded from the stent type comparisons. Among the 429 patients included in the stent comparison analyses, 43 patients (10.0%) received BMS, 74 (17.2%) received first-generation DES, and 312 (72.7%) received second-generation DES. The 1 and 2-year target lesion revascularization rates were lower among patients receiving first-generation (1.4% and 6.3%) and second-generation (3.9% and 5.0%) DES compared to patients receiving BMS (15.3% and 15.3%), respectively (1 year: P = 0.007; 2 year: P = 0.047). Higher diameter stenosis and the use of BMS were independently associated with the occurrence of MACE and TVR at 2 years. CONCLUSIONS: OAS remained safe and effective for patients with de novo, severely calcified lesions at 2 years in the ORBIT II study. Adverse ischemic events were significantly higher with BMS compared with DES. © 2016 Wiley Periodicals, Inc.

Gender differences in acute and 30-day outcomes after orbital atherectomy treatment of de novo, severely calcified coronary lesions.

OBJECTIVES: The aim of this analysis is to evaluate potential differences according to gender in terms of acute and 30-day clinical outcomes in patients enrolled in the ORBIT II trial with de novo, severely calcified coronary lesions treated with orbital atherectomy to facilitate stent delivery. BACKGROUND: Previous studies have shown an increased risk of safety events in females compared to males undergoing percutaneous coronary intervention. METHODS: ORBIT II, a prospective, nonrandomized, multicenter, single arm study conducted in the US evaluated the safety and efficacy of the coronary OAS to facilitate stent placement in de novo, severely calcified coronary lesions in 443 subjects (286 males and 157 females). The rate of major adverse cardiac events (MACE) defined as a composite of myocardial infarction, target vessel revascularization, and cardiac death was evaluated in-hospital and 30-days postprocedure. For this analysis, the ORBIT II safety and efficacy results were stratified by gender. RESULTS: At baseline, females were significantly older than males and had a lower mean estimated glomerular filtration rate. Males had a higher rate of previous coronary artery bypass grafting and history of smoking. The rates of successful stent delivery and <50% residual stenosis were similar in males and females. In-hospital and 30-day MACE rates did not differ by gender. CONCLUSIONS: Despite females being older, having smaller arteries, and more renal dysfunction, preparation of severely calcified coronary lesions with orbital atherectomy to facilitate stent deployment results in similar rates of in-hospital and 30-day MACE, irrespective of gender.

Orbital Atherectomy for Treating De Novo Severely Calcified Coronary Narrowing (1-Year Results from the Pivotal ORBIT II Trial).

Percutaneous coronary intervention of severely calcified lesions has historically been associated with major adverse cardiac event (MACE) rates as high as 30%. In the ORBIT II (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) trial, treatment of de novo severely calcified lesions with the Diamondback 360° Coronary Orbital Atherectomy System (OAS) resulted in low rates of procedural and 30-day adverse ischemic events. The long-term results from this trial have not been reported. We sought to determine the 1-year outcomes after orbital atherectomy of severely calcified coronary lesions. ORBIT II was a single-arm trial enrolling 443 subjects at 49 US sites with severely calcified lesions usually excluded from randomized trials. OAS utilizes a centrifugal differential sanding mechanism of action for plaque modification prior to stent implantation. After OAS drug-eluting stents were implanted in 88.2% of the patients. The primary safety end point was 30-day MACE, the composite of cardiac death, myocardial infarction, or target vessel revascularization [TVR]. The present analysis reports the 1-year follow-up results from ORBIT II. One-year data were available in 433 of 443 patients (97.7%), with median follow-up time of 16.7 months. The 1-year MACE rate was 16.4%, including cardiac death (3.0%), myocardial infarction (9.7%), and target vessel revascularization (5.9%). The 1-year target lesion revascularization rate was 4.7%, and stent thrombosis occurred in 1 patient (0.2%). Independent predictors of 1-year MACE and target vessel revascularization were diameter stenosis at baseline and the use of bare-metal stents. In patients with severely calcified lesions who underwent percutaneous coronary intervention, the use of OAS was associated with low rates of 1-year adverse ischemic events compared with historical controls. This finding has important clinical implications for the selection of optimum treatment strategies for patients with severely calcified lesions.

An unusual complication of epididymo-orchitis: scrotal pyocele extending into the inguinal canal mimicking a strangulated inguinal hernia.

We report a case of a paraplegic patient with an indwelling Foley catheter and epididymo-orchitis leading to a scrotal pyocele. This case is unique in that the patient's physical examination revealed both inguinal and scrotal abnormalities that mimicked a strangulated inguinal hernia. Imaging studies and surgical exploration helped elucidate the exact diagnosis. Although rare, this entity requires emergent surgical consultation. We will also discuss the etiology, pathophysiology, and treatment of scrotal abscesses.

Development and confirmatory factor analysis of the community norms of child neglect scale.

This article describes the development of the Community Norms of Child Neglect Scale (CNCNS), a new measure of perceptions of child neglect, for use in community samples. The CNCNS differentiates among four subtypes of neglect (failure to provide for basic needs, lack of supervision, emotional neglect, and educational neglect). Scenarios ranging in seriousness for each subtype were presented to a large community sample (N = 3,809). Confirmatory factor analyses indicated that a four-factor model provided a better fit to the data than did a model specifying only one overall neglect factor, suggesting this sample distinguished among the four subtypes of neglect. The authors tested measurement equivalence across individuals who work with children and lay community respondents and across rural and urban respondents, with results indicating a very similar structure across these groups. These initial reliability and validity data suggest that the CNCNS may be of use in comparing perceptions of child neglect among individuals and across communities.