Acute respiratory distress syndrome (ARDS) is a syndrome of acute lung injury that is characterized by noncardiogenic pulmonary edema and severe hypoxemia second to a pathogenic impairment of gas ...exchange. Despite significant advances in the area, mortality remains high among ARDS patients. High mortality and a limited spectrum of therapeutic options have left clinicians searching for alternatives, spiking interest in selective pulmonary vasodilators (SPVs). Despite the lack of robust evidence, SPVs are commonly employed for their therapeutic role in improving oxygenation in patients who have developed refractory hypoxemia in ARDS. While inhaled epoprostenol (iEPO) also impacts arterial oxygenation by decreasing ventilation–perfusion (V/Q) mismatching and pulmonary shunt flow, this effect is not different from inhaled nitric oxide (iNO). The most effective and safest dose for yielding a clinically significant increase in PaO2 and reduction in pulmonary artery pressure (PAP) appears to be 20–30 ng/kg/min in adults and 30 ng/kg/min in pediatric patients. iEPO appears to have a ceiling effect above these doses in which no additional benefit may be derived. iNO and iEPO have shown similar efficacy profiles; however, they differ with respect to cost and ease of therapeutic administration. The most beneficial effects of iEPO have been seen in adult patients with secondary ARDS as compared with primary ARDS, most likely due to the difference in etiology of the two disease states, and in patients suffering from baseline right ventricular heart failure. Although iEPO has demonstrated improvements in hemodynamic parameters and oxygenation in ARDS patients, due to the limited number of randomized clinical trials and the lack of studies investigating mortality, the use of iEPO cannot be recommended as standard of care in ARDS. iEPO should be reserved for those refractory to traditional therapies.
A single copy of bacteriophage T7 DNA polymerase and DNA helicase advance the replication fork with a processivity greater than 17,000 nucleotides. Nonetheless, the polymerase transiently dissociates ...from the DNA without leaving the replisome. Ensemble and single-molecule techniques demonstrate that this dynamic processivity is made possible by two modes of DNA polymerase-helicase interaction. During DNA synthesis the polymerase and the helicase interact at a high-affinity site. In this polymerizing mode, the polymerase dissociates from the DNA approximately every 5000 bases. The polymerase, however, remains bound to the helicase via an electrostatic binding mode that involves the acidic C-terminal tail of the helicase and a basic region in the polymerase to which the processivity factor also binds. The polymerase transfers via the electrostatic interaction around the hexameric helicase in search of the primer-template.
The purpose of this study was to describe selected college students’ (N = 252) perceptions of and future intentions (FI) to engage in public-sphere water conservation behaviors, and to determine if ...FI could be predicted by a single or linear combination of student demographic characteristics and latent variables. A majority of respondents agreed a growing population will negatively affect water quantity (90.5%) and there is a need for water resource management (85.6%). A majority disagreed or strongly disagreed that they (53.4%), their family (57.1%), or their friends (67.5%) practiced water conservation, or that people in their hometowns were concerned about local water availability (78.1%). A majority agreed they would engage in four of five public-sphere water conservation behaviors in the future: support water conservation programs (86.4%), care more deeply about water conservation (81.2%), join a water conservation organization (79.2%), and vote for stricter water use laws (55.0%). Fewer than one-half agreed or strongly agreed they would donate money to support water conservation (45.8%). Responses to statements concerning water conservation were factor analyzed and two factors were extracted: lack of agency (LA) and subjective norms (SN). A linear combination of gender, LA, and SN explained 36.7% of the variance in FI.
Multiplexed analysis of multiple biomarkers in a tissue sample requires use of reporter dyes with specific spectral properties that enable discrimination of signals. Conventional chromogens with ...broad absorbance spectra, widely used in immunohistochemistry (IHC), offer limited utility for multiplexed detection. Many dyes with narrow absorbance spectra, eg rhodamines, fluoresceins, and cyanines, potentially useful for multiplexed detection are well-characterized; however, generation of a chromogenic reagent useful for IHC analysis has not been demonstrated. Studies reported herein demonstrate utility of tyramine-chemistry for synthesis of a wide variety of new chromogenic dye conjugates useful for multiplexed in situ analysis using conventional light microscopes. The dyes, useful individually or in blends to generate new colors, provide signal sensitivity and dynamic range similar to conventional DAB chromogen, while enabling analysis of co-localized biomarkers. It is anticipated that this new paradigm will enable generation of a wide variety of new chromogens, useful for both research and clinical biomarker analysis that will benefit clinicians and patients.
Honey bees forage across a large area, continually scouting the local landscape for ephemeral food resources. Beekeepers often rely on flowering plants in and around irrigated farmland to maintain ...their colonies during dry seasons, despite the potential risk of pesticide exposure. Recent declines in pollinator abundance and diversity have focused attention on the role of pesticides and their effects on honey bee health. This investigation examined two types of landscapes within a two-mile (3.2 km) radius of honey bee colonies: an intensive agricultural setting and a rural setting without intensive agriculture. More than 10,000 acres of agricultural land was surveyed to quantify the area of cultivated crops and the area treated with pesticides, including seed treatments and foliar applications of insecticides. Samples of honey, bee bread (stored pollen), beeswax, and adult bees were collected from hives in both landscape types and screened for pesticide residues to determine if foraging bees were transporting pesticides to hives. Some samples of bee bread and honey did contain pesticide residues, but these were below known lethal dose (LD
) levels for honey bees. Beeswax samples contained the highest levels of contamination, but most were still relatively low. Samples were screened for 174 common agricultural pesticides and metabolites, but only 26 compounds were detected during the two-year study. These included one defoliant, one insect growth regulator, five herbicides, six fungicides, six insecticides never used in beekeeping, and five insecticides/miticides and their metabolites, which are used in beekeeping and for various other agricultural purposes, as well as two miticides exclusively used by beekeepers to control
. Bee colonies foraging in agricultural landscapes are potentially exposed to numerous pesticide applications. While the residues detected in this study did not pose an acute lethal risk to adult honey bees, this study did not measure sublethal effects on bee colony health or performance, which merit further investigation.
Context: Hypertonic saline (HTS) is a pharmacologic therapy used in patients with severe traumatic brain injuries to decrease intracranial pressure (ICP) associated with cerebral edema. Aims: The ...purpose of this study was to compare ICP reduction between fixed doses of 23.4% HTS and weight-based doses. Setting and Design: This was a retrospective study that included adult patients at a level 1 trauma center who had nonpenetrating traumatic brain injury, an ICP monitor, and received at least one dose of 23.4% HTS. Subjects and Methods: Doses were classified as either high weight-based (>0.6 ml/kg), low weight-based (<0.6 ml/kg), or standard fixed dose (30 ml). Only doses given within 5 days post-injury were evaluated. Percent reduction in ICP was compared pre- and post-dose between dosing groups, and each dose was evaluated as a separate episode. Statistical Analysis: The primary and secondary endpoints for the study were analyzed using mixed-model, repeated-measures analysis of covariance. Results: A total of 97 doses of HTS were evaluated. The primary endpoint of ICP reduction showed a 42.5% decrease in ICP after the administration of a high weight-based dose, a 36.7% reduction after a low weight-based dose, and a 31.5% reduction after a fixed dose. There was no significant relationship between dose group and percent change in ICP (P = 0.25). A sub-analysis of doses received within 48 h postinjury found a significant relationship between both dose group and percent change in ICP, and initial ICP and percent change in ICP (P = 0.04, and <0.0001 respectively). Conclusions: Our data did not show a significant difference between fixed- and weight-based doses of 23.4% HTS for ICP reduction.
Retrospective chart review.
To determine complications within the first year after undergoing extreme lateral interbody fusion (XLIF).
There are a growing but limited number of reports in the ...literature regarding early postoperative complications after XLIF.
We performed a retrospective chart review of perioperative complications of a case series of the first 108 patients to undergo XLIF at our institution between 2007 and 2009. We also recorded estimated blood loss, surgical time, and hospital length of stay for each procedure.
There were 25 complications (23%) overall in patients who underwent the XLIF procedure. Four patients (3.7%) experienced major complications including: vertebral body fracture, contralateral nerve root injury, dense quadriceps paresis, and persistent stenosis. Three of these patients underwent revision surgery. There were 21 minor (19.4%) complications the vast majority of which consisted of approach-related thigh pain and/or paresthesias that all ultimately resolved.
Transient ipsilateral thigh numbness, pain, and/or hip flexor weakness is a frequent postoperative finding most commonly when the L4-L5 level is instrumented. Dense femoral nerve palsy is a debilitating complication that may occur despite intraoperative neurophysiological monitoring. It should be noted that this retrospective study may underreport the true incidence of complications among these patients.
This study investigated a sample of 979 full-time, first semester freshmen (FTFSF) university students using data from an individual institution's National Survey of Student Engagement (NSSE) to ...determine if university pre-entry admissions data, satisfaction, self-reported grades, or
student engagement could be used to predict six-year degree completion. Results indicated that self-reported freshman grades, high school grade-point average (HSGPA), being from a metro area, and satisfaction with college experiences were positive indicators of increased likelihood of graduating
within six years. Satisfaction with academic advising and Pell grant eligibility were found to be negative predictors of six-year degree completion. These findings can be used to focus recruiting efforts, as well as identify students who may be at risk of attrition.