Comparative ozone responses of cutleaf coneflowers (Rudbeckia laciniata var. digitata, var. ampla) from Rocky Mountain and Great Smoky Mountains National Parks, USA.

Cutleaf coneflower (Rudbeckia laciniata L. var. digitata) is native to Great Smoky Mountains National Park (GRSM) and an ozone bioindicator species. Variety ampla, whose ozone sensitivity is less well known, is native to Rocky Mountain National Park (ROMO). In the early 2000s, researchers found putative ozone symptoms on var. ampla and rhizomes were sent to Appalachian State University to verify that the symptoms were the result of ozone exposure. In 2011, potted plants were exposed to ambient ozone from May to August. These same plants were grown in open-top chambers (OTCs) in 2012 and 2013, and exposed to charcoal-filtered (CF), non-filtered (NF), elevated ozone (EO), NF+50ppb in 2012 for 47days and NF+30/NF+50ppb ozone in 2013 for 36 and 36days, respectively. Ozone symptoms similar to those found in ROMO (blue-black adaxial stippling) were reproduced both in ambient air and in the OTCs. Both varieties exhibited foliar injury in the OTCs in an exposure-dependent manner, verifying that symptoms resulted from ozone exposure. In two of the three study years, var. digitata appeared more sensitive than var. ampla. Exposure to EO caused reductions in ambient photosynthetic rate (A) and stomatal conductance (gs) for both varieties. Light response curves indicated that ozone reduced A, gs, and the apparent quantum yield while it increased the light compensation point. In CF air, var. ampla had higher light saturated A (18.2±1.04 vs 11.6±0.37µmolm-2s-1), higher light saturation (1833±166.7 vs 1108±141.7µmolm-2s-1), and lower Ci/Ca ratio (0.67±0.01 vs 0.77±0.01) than var. digitata. Coneflowers in both Parks are adversely affected by exposure to ambient ozone and if ozone concentrations increase in the Rocky Mountains, greater amounts of injury on var. ampla can be expected.

Changes in adjuvant therapy utilization in stage I seminoma: are they enough to prevent overtreatment?

OBJECTIVE: To determine if utilization of surveillance or adjuvant chemotherapy has increased compared with that of adjuvant radiotherapy (ART) in clinical stage I seminoma (CSIS) and to estimate the impact of this utilization trend on secondary malignancies. METHODS: The National Cancer Data Base, a web-based data analysis tool was examined for first-course adjuvant therapy management in CSIS from 2000 to 2008. We assessed the utilization in academic vs community practice settings and changes in tumor stage. We also estimated the number of secondary malignancies based on the change in practice. RESULTS: There were 52,672 patients of testicular cancer diagnosed. Of those, 28,974 (55.0%) patients had seminoma with 22,210 (84.2%) patients classified as CSIS. Overall, 14,005 (65.4%), 6430 (30.1%), and 951 (4.4%) patients received ART, surveillance, and adjuvant chemotherapy (AC), respectively. In 2000, most patients received ART (71.7%), followed by surveillance (26.5%), and AC (1.9%). In 2008, the majority of patients still received ART (47.7%) but surveillance (39.6%) and AC (12.6%) totaled a larger proportion. We calculated that this ART utilization rate would lead to an additional 372 solid tumor cases per year, 40 years later, whereas the current surveillance rate would lead to 34 cases of secondary malignancy annually in the United States. CONCLUSION: ART was the leading adjuvant management strategy for CSIS, but its share drastically decreased with a concomitant increase in surveillance and AC, particularly after 2004. These trends were similar in both academic and community settings. The current level of ART, although decreasing, may nevertheless lead to additional cases of solid cancer comparable with testicular cancer deaths.

A Single Surgeon's Experience with Open, Laparoscopic, and Robotic Partial Nephrectomy.

Objective. To report the perioperative outcomes of patients treated with partial nephrectomy by a single surgeon using three surgical modalities-open, laparoscopic, and robotic. Methods. Between August 2006 and February 2012, 106 consecutive patients underwent open partial nephrectomy (OPN) (n = 23), laparoscopic partial nephrectomy (LPN) (n = 48), and robotic partial nephrectomy (RPN) (n = 35) by a single surgeon. Clinical variables, operative parameters, and renal functional outcomes were analyzed. Results. Preoperative patient characteristics were similar except for baseline glomerular filtration rate (GFR), which was highest in the RPN group (P = 0.004). Surgery time was longest in the RPN group (244 minutes) and shortest in the OPN group (163 minutes, P < 0.0001). Patients who had OPN had the highest incidence of 30-day complications (30%), while the RPN approach had the lowest (14%, P = 0.008). Conclusions. When performed by a single surgeon, robotic partial nephrectomy appears to be associated with fewer complications than both open and laparoscopic partial nephrectomy. Kidney function was not affected by surgical approach.

Dual immunofluorescence staining of proteoglycans in human temporal bones.

OBJECTIVES/HYPOTHESIS: Immunofluorescence staining methods have been developed to study the distribution of macromolecules in archival formalin-fixed celloidin-embedded human temporal bone tissues. The aim of this study was to investigate the feasibility of utilizing this approach to evaluate the codistribution of more than one molecule of interest in a single tissue section. STUDY DESIGN: Retrospective study of proteoglycan codistribution in archival human temporal bone tissues. METHODS: The chondroitin sulfate and keratan sulfate proteoglycans were selected for evaluating this methodology. Human tissues with known proteoglycan staining patterns were studied as controls. Thirty-one formalin-fixed celloidin-embedded archival human temporal bones were evaluated, and the observations in 11 specimens are described. A dual immunofluorescence staining method was developed using primary antibodies of differing isotypes and secondary antibodies labeled with fluorophores having nonoverlapping emission characteristics. RESULTS: The specificity of the dual immunofluorescence technique for chondroitin sulfate and keratan sulfate proteoglycans was demonstrated in control tissues and confirmed through inhibition studies. The normal human tectorial membrane exhibited intense chondroitin sulfate staining. Cochlear and vestibular hair cells exhibited predominantly keratan sulfate staining. Keratan sulfate staining predominated in spiral ganglion cell bodies and fibers. Alterations in the normal distribution pattern of proteoglycans were observed in cases of presbycusis and otosclerosis. CONCLUSIONS: The dual immunofluorescence staining methodology can be used to study archival formalin-fixed celloidin-embedded human temporal bone tissues. This technique may be applied to the evaluation of other molecules in archival human temporal bone tissues and lead to improvement in our understanding of the function of these molecules and their role in disease processes.

Assessing the risk of foliar injury from ozone on vegetation in parks in the U.S. National Park Service's Vital Signs Network.

The risk of ozone injury to plants was assessed in support of the National Park Service's Vital Signs Monitoring Network program. The assessment examined bioindicator species, evaluated levels of ozone exposure, and investigated soil moisture conditions during periods of exposure for a 5-year period in each park. The assessment assigned each park a risk rating of high, moderate, or low. For the 244 parks for which assessments were conducted, the risk of foliar injury was high in 65 parks, moderate in 46 parks, and low in 131 parks. Among the well-known parks with a high risk of ozone injury are Gettysburg, Valley Forge, Delaware Water Gap, Cape Cod, Fire Island, Antietam, Harpers Ferry, Manassas, Wolf Trap Farm Park, Mammoth Cave, Shiloh, Sleeping Bear Dunes, Great Smoky Mountains, Joshua Tree, Sequoia and Kings Canyon, and Yosemite.

Absence of correlation between symptoms and rhythm in "symptomatic" atrial fibrillation.

BACKGROUND: Symptoms are widely used as a means of assessment and follow-up of patients with atrial fibrillation. This study assessed the correlation between symptoms and cardiac rhythm in patients being evaluated for operative therapy for atrial fibrillation. METHODS: Seven days of preoperative continuous outpatient home electrocardiographic monitoring was performed on 50 patients with symptomatic atrial fibrillation. Cardiac rhythm was continuously monitored automatically, while patients recorded their symptoms electronically. Correlations were then drawn between symptomatic events and actual rhythm, and between atrial fibrillation episodes and symptoms. RESULTS: Fifty patients (37 men) with symptomatic atrial fibrillation were monitored for a combined 356 days (mean, 7.1 days). Patients were average age of 69 years old. Intermittent atrial fibrillation was reported by 36 patients, and 14 believed their atrial fibrillation was continuous. During monitoring, all patients had periods of both atrial fibrillation and normal sinus rhythm. Of the 552 documented episodes of atrial fibrillation, 467 (85%) were asymptomatic, and 85 (15%) episodes were symptomatic. Patients indicated that they experienced atrial fibrillation symptoms 163 times. Of the 163 symptomatic events, 85 (52%) were actual atrial fibrillation, 64 (42%) were sinus rhythm, and 14 (6%) were other rhythms. The ability of an individual patient to accurately identify atrial fibrillation ranged from 0% to 100%. CONCLUSIONS: Patient-reported symptoms of atrial fibrillation had poor correlation with actual rhythm. The lack of correlation between symptoms and rhythm underscores the importance of continuous home monitoring for accurately quantifying preoperative atrial fibrillation burden and for postoperative follow-up.

Intraoperative epicardial electrophysiologic mapping and isolation of autonomic ganglionic plexi.

BACKGROUND: Autonomic ganglionic plexi (GPs) have been implicated as triggers in lone atrial fibrillation (AF). The purpose of this study was to describe the technique and results of epicardial electrophysiologic mapping and the early effects of GP isolation. METHODS: Intraoperative epicardial electrophysiologic mapping was performed on 41 consecutive patients during a stand-alone minimally invasive operation for AF. A map labeling anatomic locations was developed to describe the findings. Intraoperative high-frequency stimulation (800/minute, 12 to 16 mA, pulse duration 9.9 ms) was performed using a standard quadripolar catheter placed directly on the epicardium. Locations where stimulation resulted in ventricular slowing with doubling of the electrocardiographic R-R interval were defined as active GPs. These areas were mapped and described. After dry bipolar radiofrequency isolation, the sites were again stimulated to assess isolation. RESULTS: Forty-one patients (mean age of 60.2 years, 31 males) underwent operation for AF (28 intermittent AF, 13 chronic). Active GPs were identified in all patients (24 bilateral, 17 unilateral). There was a mean of 5.0 GPs on the right and 2.7 on the left. More than 50% of patients had active GPs along the interatrial groove on the right and along the ligament of Marshall. All sites were inactive after radiofrequency isolation. Six-month follow-up is available for 15 patients, with 14 patients free of AF. CONCLUSIONS: Autonomic GPs can be routinely identified during AF surgery utilizing high-frequency stimulation. The GPs are clustered around the interatrial groove and the ligament of Marshall, and the cardiac response to GP stimulation can be eliminated with bipolar radiofrequency isolation. The addition of GP isolation to bilateral pulmonary vein isolation may increase freedom from AF.

Ability of static and statistical mechanics posturographic measures to distinguish between age and fall risk.

Traditional posturographic analysis and four statistical mechanics techniques were applied to center-of-pressure (COP) trajectories of young, older "low-fall-risk" and older "high-fall-risk" individuals. Low-fall-risk older adults were active 3 days per week in a cardiac rehabilitation program, while high-fall-risk older adults were diagnosed with perilymph fistula. Subjects diagnosed with perilymph fistula must have experienced two of the following vestibular findings: constant disequilibrium, positional vertigo and/or a positive fistula test. Non-parametric statistical tests were used to determine whether the posturographic measures could detect differences between the young and older "low-fall-risk" groups (age comparison) and between the older "low-" and "high-risk" groups (risk of falling comparison). The statistical mechanics techniques were more sensitive than the traditional measures: detecting significant differences between the young and older "low-risk" groups, while none of the traditional measures were significantly different. In addition, interpretation of the statistical mechanics techniques may offer more insight into the nature of the process controlling the COP trajectories. However, the methods offered slightly different explanations. For instance, the Hurst rescaled range analysis suggests that the movement of the COP is governed solely by anti-persistent behavior, whereas the stabilogram diffusion analysis suggests a short-term persistence balanced by a long-term anti-persistence. These discrepancies highlight the need for a model that incorporates the biological systems responsible for maintaining balance and experimental methods to directly quantify their status and roles. Until such a model exists, however, the statistical mechanics techniques appear to have some advantages over traditional posturographic measures for studying balance control.

The long-term effects of carbon dioxide on natural systems: issues and research needs.

Research on the responses of plants to increasing levels of carbon dioxide has largely assessed physiological, phenotypic, and community-level effects. Little attention has been directed to investigating the possibility that escalating levels of carbon dioxide may serve as a selection pressure altering the genetic diversity of plant populations. Plant populations exposed to elevated levels of heavy metals or ozone have been shown to undergo selection, and it is reasonable to consider that populations experiencing long-term exposure to escalating levels of carbon dioxide may show similar responses. Selection of this nature could be particularly significant because of the global extent of the effect. Genetic selection occurs when plants are subject to an agent of selection and three conditions for a property responsive to the agent are satisfied at the population level. In the population, variation must exist in the property, part of the variation must be genetically controlled, and variation in the property must affect reproductive fitness. If these conditions are satisfied, the frequency distribution of the property, and the gene frequency associated with it, will change over time in response to the agent of selection. Research on the selection pressure effects of carbon dioxide involves assessments that integrate across temporal, spatial, and biological scales, and embrace variation in the environment and genetics. To be effective, the research will have to adopt approaches that have not been commonly employed in previous air quality studies. The questions posed are biologically complex, and new research approaches and methods are required to answer them. Some of the new approaches that can be used to assess changes in gene frequency include use of natural carbon dioxide gradients, model plant systems, molecular markers, and DNA microarray technology.