Spatial Organization of Lipid Nanoparticle siRNA Delivery Systems Revealed by an Integrated Magnetic Resonance Approach.

Lipid nanoparticles (LNPs) are increasingly finding applications in targeted drug delivery, including for subcutaneous, intravenous, inhalation, and vaccine administration. While a variety of microscopy techniques are widely used for LNP characterization, their resolution does not allow for characterization of the spatial organization of different components, such as the excipients, targeting agents, or even the active ingredient. Herein, an approach is presented to probe the spatial organization of individual constituent groups of LNPs used for siRNA-based drug delivery, currently in clinical trials, by multinuclear solid-state magic-angle-spinning nuclear magnetic resonance (MAS NMR) spectroscopy. Dynamic nuclear polarization is exploited (DNP) for sensitivity enhancement, together with judicious 2H labeing, to detect functionally important LNP constituents, the siRNA and the targeting agent (<1-2 w/v%), respectively, and achieve a structural model of the LNP locating the siRNA in the core, the targeting agent below the surface, and the sugars above the lipid bilayer at the surface. The integrated approach presented here is applicable for structural analysis of LNPs and can be extended more generally to other multi-component biological formulations.

Optimization of Care for the Elderly Surgical Emergency Patient.

Geriatric patients undergoing emergency surgery are at significantly higher risk for complications and death when compared with younger patients. Optimizing care for these patients requires a multidisciplinary team, special attention to physiologic changes and medication use, as well as targeted intervention to mitigate complications such as delirium, which can worsen overall outcomes. Frailty can be assessed preoperatively to identify patients at the highest risk for complications. Shared decision-making with both the family and patient during the consent process is integral to defining patient's goals of care in these high-risk situations.

Impact of Fluid Balance on Intensive Care Unit Length of Stay in Critically Ill Trauma Patients.

BACKGROUND: There is significant data in the medical and surgical literature supporting the correlations between positive volume balance and negative outcomes such as AKI, prolonged mechanical ventilation, intensive care unit and hospital length of stay and increased mortality. METHODS: This single-center, retrospective chart review included adult patients identified from a Trauma Registry database. The primary outcome was the total ICU LOS. Secondary outcomes include hospital LOS, ventilator-free days, incidence of compartment syndrome, acute respiratory distress syndrome (ARDS), renal replacement therapy (RRT), and days of vasopressor therapy. RESULTS: In general, baseline characteristics were similar between groups with the exception of mechanism of injury, FAST exam, and disposition from the ED. The ICU LOS was shortest in the negative fluid balance and longest in the positive fluid balance group (4 days vs 6 days, P = .001). Hospital LOS was also shorter in the negative balance group than that of the positive balance group (7 days vs 12 days, P < .001). More patients in the positive balance group experienced acute respiratory distress syndrome compared to the negative balance group (6.3% vs 0%, P = .004). There was no significant difference in the incidence of renal replacement therapy, days of vasopressor therapy, or ventilator-free days. DISCUSSION: A negative fluid balance at seventy-two hours was associated with a shorter ICU and hospital LOS in critically ill trauma patients. Our observed correlation between positive volume balance and total ICU days merits further exploration with prospective, comparative studies of lower volume resuscitation to key physiologic endpoints compared with routine standard of care.

Seasonal variation in morphotype composition of pelagic Sargassum influx events is linked to oceanic origin.

The recent proliferation of pelagic Sargassum spp. in the Tropical Atlantic causes major ecological and socioeconomic impacts to the wider Caribbean when it washes ashore, with regional fisheries and tourism industries particularly affected. The Caribbean influxes have been tracked to a new bloom region known as the North Equatorial Recirculation Region (NERR) encompassing the area between the South Equatorial Current and the North Equatorial Counter Current and extending from Africa to South America. The vast biomass of Sargassum presents serious problems when it washes ashore but also represents significant commercial opportunities, especially with biofuel and fertilizer. The floating Sargassum mats are themselves diverse ecosystems that vary both in their biodiversity and biochemical attributes. Two major species (Sargassum fluitans and S. natans) have been identified as well as several distinguishable morphotypes of each. Oceanic mixing tends to blend the morphotypes together making it difficult to determine if there are regions of the NERR that favour bloom and growth of the distinct types. In this study, we quantify the species and morphotype composition of Sargassum strandings in Barbados and test if this is related to separate oceanic origins and routes travelled using a backtracking algorithm based on ocean drifter data. We found significant seasonal variation in the relative abundance of three morphotypes and this could be traced to two distinct easterly sub-origins and/or transport pathways; one area around 15° N that travels directly E-W across the Atlantic, and another area generally south of 10° N that takes a more meandering route coming close the coast of South America. These findings contribute towards our understanding of why the Tropical Atlantic bloom is presently occurring as well as towards addressing valorisation constraints surrounding variation in the supply of the three commonly occurring morphotypes.

Management of Paroxysmal Sympathetic Hyperactivity with Dexmedetomidine and Propranolol Following Traumatic Brain Injury in a Pediatric Patient.

We report a case of pharmacologic management of pediatric paroxysmal sympathetic hyperactivity (PSH) in a patient who experienced symptomatic resolution with dexmedetomidine and propranolol. Following a blunt traumatic subdural hematoma and diffuse axonal injury, an 8-year-old male developed PSH on approximately day 5 of the hospitalization. PSH symptoms identified in this patient were hyperthermia, tachycardia, posturing, and hypertension with associated elevations in intracranial pressure. Episodes of PSH continued to be observed despite appropriate titration of opiates, sedatives, and traditional blood pressure management. Dexmedetomidine and propranolol were subsequently initiated to attenuate acute episodes of PSH. A reduction in sedative requirements and improvement in symptoms followed, which facilitated successful extubation. The combination of propranolol and dexmedetomidine was followed by a decrease in the frequency and severity of acute episodes of PSH. After utilization of multiple treatment modalities to control PSH episodes in our patient, propranolol and dexmedetomidine may have helped attenuate PSH signs and symptoms.

Comparison of Weight-Based Dosing versus Fixed Dosing of 23.4% Hypertonic Saline for Intracranial Pressure Reduction in Patients with Severe Traumatic Brain Injury.

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.

Comprehensive Survey of Area-Wide Agricultural Pesticide Use in Southern United States Row Crops and Potential Impact on Honey Bee Colonies.

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 (LD50) 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 Varroa destructor. 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.

Prolonged Antibiotics for Drains After Spine Injury Instrumentation for Trauma: Not Prophylactic or Necessary.

BACKGROUND: Antibiotics after spine instrumentation are often extended while the surgical drain is in place, particularly for traumatic injuries. We sought to study if continuing antibiotics past 24 hours affected outcomes. METHODS: We performed a retrospective observational study of all patients who underwent spine fixation with hardware and surgical drains for trauma at our institution. We compared the effect of perioperative (≤24 hours of antibiotics) versus prolonged (>24 hours) antibiotics on surgical outcomes. Bivariate and multivariable logistic and linear regression statistics were performed. RESULTS: Three hundred and forty-six patients were included in the analysis. On multivariate analysis, antibiotic duration >24 hours did not predict surgical site infection (odds ratio, 2.68; 95% confidence interval, 0.88-8.10, P = 0.08) or mortality (odds ratio, 0.59; 95% confidence interval, 0.10-3.44; P = 0.56). CONCLUSIONS: Continuing antibiotics past 24 hours after traumatic spine instrumentation was not associated with improved outcomes. A prospective study to verify these findings may be warranted.

Addressing Religious or Cultural Opposition to Brain Death Diagnosis.

In 1968, the neurologic or "brain death" standard for declaration was introduced as an accepted standard for declaration of death in hospitals where heartbeat and breathing are being sustained by technology, but functions of the brain, including the brain stem, have ceased. For many people, this accepted ethical, legal, and medical definition of death by neurologic standards can seem to blur the line between life and death as the heart is still beating, the lungs are still moving air albeit by mechanical ventilation, and the body is still warm. As experts in end-of-life care, hospice and palliative care nurses must be knowledgeable about declaration of death by neurologic criteria, understand beliefs that do not support the concept, and collaborate with the health care team in providing compassionate end-of-life care. This article will use a case study to describe the legal and ethical challenges that ensue when religious and/or cultural beliefs result in rejection of the concept of brain death and propose ethically sound strategies to navigate these challenges within a framework of culturally congruent care that includes a 4-step process to progressively appreciate, accommodate, negotiate, and/or explicate the differences.

Editorial Commentary: A Revisit of an Old Clinical Dilemma-To Operate or Not to Operate on Acute Knee Anterior Cruciate Ligament Injuries.

There is a feeling among knee surgeons that operating on an acute anterior cruciate ligament injury will increase the incidence of arthrofibrosis. A recent systematic review and meta-analysis of 7 recent articles compared early versus delayed anterior cruciate ligament reconstruction. The conclusions were that the clinical and stability results were comparable in both groups.

A Molecular Method to Detect Wound Cells in Bloodstains Resultant of Sharp Force Injuries for Crime Scene Reconstruction.

Previous research by the authors on an animal model showed that bloodstains can contain additional information about their somatic origin in the form of wound cells. Bloodstains produced by a gunshot wound to the head were distinguished from bloodstains produced by a gunshot wound to the chest by testing the stains for a brain microRNA marker. In this study, the effectiveness of the technique was examined on blood drops shed externally from a stab wound to the liver of rat carcasses. Specifically, investigations were conducted on the liver microRNA marker, rno-mir-122-3p, with the QIAGEN miScript System, and PCR analysis. Between the two stabbing methods used, 67% of the scalpel blades and 57% of the blood drops tested positive for rno-mir-122-3p; however, other samples tested negative giving inconclusive results as to the wound-of-origin. The amount of the liver cells in the bloodstains appeared to be related to the extent of trauma.

Evaluation of Neuroleptic Utilization in the Intensive Care Unit During Transitions of Care.

PURPOSE: The purpose of this study was to identify risk factors associated with inappropriate continuation of neuroleptics postdischarge from the intensive care unit (ICU) and hospital. MATERIALS AND METHODS: A retrospective chart review was performed including all patients greater than 18 years of age who received neuroleptic medications in an ICU. RESULTS: One hundred sixty-one patients were included during the 12- month study period. There were 85 (53%) patients discharged from the ICU with inappropriate continuation of a neuroleptic medication. There were 54 (34%) patients discharged from the hospital with inappropriate continuation of a neuroleptic medication. Patients were more likely to be discharged from the ICU with an inappropriate neuroleptic if they were prescribed multiple neuroleptics ( P = .02), did not have a urine drug screen collected at admission ( P = .023), or if trazodone was utilized in their therapy ( P = .004). Patients were more likely to be discharged from the hospital with a neuroleptic if they had multiple neuroleptic orders ( P = .0001) or if trazodone was utilized in their therapy ( P = .0023). CONCLUSION: Risk factors associated with the continuation of inappropriate neuroleptic medications upon discharge from the ICU or the hospital include multiple neuroleptic medications prescribed, the lack of a urine drug screen upon admission, and the utilization of trazodone.

Failure of chemical thromboprophylaxis in critically ill medical and surgical patients with sepsis.

PURPOSE: Critically ill patients who develop sepsis may be at a higher risk of venous thromboembolism (VTE) prophylaxis failure; however, studies in this population are limited. The objective of this study was to identify the incidence of VTE prophylaxis failure in this population. METHODS: This retrospective review of patients admitted to the intensive care unit between February 2013 and September 2015 included patients who were diagnosed with sepsis and received heparin or enoxaparin VTE prophylaxis. RESULTS: Of the 355 patients included, 42 (12.5%) developed a VTE. Acute respiratory distress syndrome (ARDS) (31% vs 16.7%, P = .0272) and higher positive end expiratory pressure (10 vs 8, P = .0066) were associated with increased risk of VTE prophylaxis failure. Logistic regression identified ARDS an event risk factor (odds ratio, 2.58; 95% confidence interval, 1.22-5.42). The VTE was associated with an increased intensive care unit (14 vs 9 days, P = .01) and hospital length of stay (26 vs 15 days, P < .0001). The median time from sepsis diagnosis to VTE event was 9 days (interquartile range, 5-13). CONCLUSION: Critically ill patients with sepsis had a high rate of VTE prophylaxis failure with ARDS being identified as a risk factor for VTE prophylaxis failure.

Disparities in hemodynamic resuscitation of the obese critically ill septic shock patient.

BACKGROUND: With a growing obesity epidemic, the approach to care of this patient remains controversial and in many circumstances different than the general population. Appropriate hemodynamic support, although still controversial, remains a cornerstone of septic shock therapy. Catecholamines are currently recommended by guidelines without a preferred dosing strategy. However, the use of weight-based (µg kg-1 min-1) or nonweight-based (µg/min) vasopressor drip rates may impact patient care in these populations. METHODS: A multicenter retrospective chart review was conducted. Patients receiving nonweight-based catecholamine infusions for septic shock were grouped into nonobese (n = 112) or obese (n = 196), and evaluated based on hemodynamic resuscitation. For the primary outcome, groups were analyzed for the requirement of a secondary hemodynamic support agent to obtain a goal mean arterial pressure of greater than or equal to 65 mm Hg. Secondary outcomes included an evaluation of time to a secondary hemodynamic support agent, time to hemodynamic stability (HDS), ability to obtain HDS at 24 hours, and death due to cardiovascular collapse. RESULTS: With the exception of weight and sex, baseline characteristics were similar among groups. Early resuscitative fluids were given at a lower weight based, but not total volume dose in the obese group (nonobese, 34.8 mL/kg vs obese, 22.4 mL/kg; P < .0001). The primary end point of addition of any secondary hemodynamic support agent was significantly greater in obese patients when adjusted for institution (nonobese, 19% vs obese, 27%; adjusted odds ratio, 0.42; 95% confidence interval, 0.23-0.77). Time to HDS was also prolonged (nonobese, 3.5 hours vs obese, 5.3 hours; P = .006). CONCLUSION: This study calls into question the adequacy of a nonweight-based approach to hemodynamic support of critically ill obese patients. This strategy seems to result in less aggressive, lower weight-based vasopressor and fluid doses, and more diverse approach than their nonobese counterparts.

Covalently deposited dyes: a new chromogen paradigm that facilitates analysis of multiple biomarkers in situ.

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.

Early-onset pediatric atopic dermatitis is TH2 but also TH17 polarized in skin.

BACKGROUND: Atopic dermatitis (AD) affects 15% to 25% of children and 4% to 7% of adults. Paradigm-shifting discoveries about AD have been based on adult biomarkers, reflecting decades of disease activity, although 85% of cases begin by 5 years. Blood phenotyping shows only TH2 skewing in patients with early-onset pediatric AD, but alterations in early pediatric skin lesions are unknown, limiting advancement of targeted therapies. OBJECTIVE: We sought to characterize the early pediatric AD skin phenotype and its differences from pediatric control subjects and adults with AD. METHODS: Using immunohistochemistry and quantitative real-time PCR, we assessed biopsy specimens from 19 children with AD younger than 5 years within 6 months of disease onset in comparison with adults with AD or psoriasis and pediatric and adult control subjects. RESULTS: In lesional skin children showed comparable or greater epidermal hyperplasia (thickness and keratin 16) and cellular infiltration (CD3+, CD11c+, and FcεRI+) than adults with AD. Similar to adults, strong activation of the TH2 (IL-13, IL-31, and CCL17) and TH22 (IL-22 and S100As) axes and some TH1 skewing (IFN-γ and CXCL10) were present. Children showed significantly higher induction of TH17-related cytokines and antimicrobials (IL-17A, IL-19, CCL20, LL37, and peptidase inhibitor 3/elafin), TH9/IL-9, IL-33, and innate markers (IL-8) than adults (P < .02). Despite the characteristic downregulation in adult patients with AD, filaggrin expression was similar in children with AD and healthy children. Nonlesional skin in pediatric patients with AD showed higher levels of inflammation (particularly IL-17A and the related molecules IL-19 and LL37) and epidermal proliferation (keratin 16 and S100As) markers (P < .001). CONCLUSION: The skin phenotype of new-onset pediatric AD is substantially different from that of adult AD. Although excess TH2 activation characterizes both, TH9 and TH17 are highly activated at disease initiation. Increases in IL-19 levels might link TH2 and TH17 activation.

Postoperative Complications Within the First Year After Extreme Lateral Interbody Fusion: Experience of the First 108 Patients.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: To determine complications within the first year after undergoing extreme lateral interbody fusion (XLIF). SUMMARY OF BACKGROUND DATA: There are a growing but limited number of reports in the literature regarding early postoperative complications after XLIF. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Nevospheres from neurocutaneous melanocytosis cells show reduced viability when treated with specific inhibitors of NRAS signaling pathway.

BACKGROUND: Neurocutaneous melanocytosis (NCM) is characterized by clonal nevomelanocytic proliferations in the CNS and skin. Given the scarcity of effective therapeutic targets, testing new drugs requires a reliable and reproducible in vitro cellular model of the disease. METHODS: We generated nevomelanocytic spheroids in vitro from lesions of the spinal cord, brain, and skin from 4 NCM patients. Nevomelanocytic cells were grown as monolayers or spheroids and their growth characteristics were evaluated. Cultured cell identity was confirmed by demonstration of the same NRAS mutation found in the original lesions and by immunophenotyping. Nevomelanocytic spheroids were treated with inhibitors of specific mediators of the NRAS signaling pathway (vemurafenib, MEK162, GDC0941, and GSK2126458). Drug sensitivity and cell viability were assessed. RESULTS: Cultured cells were growth-factor dependent, grew as spheroids on Geltrex matrix, and maintained their clonogenicity in vitro over passages. Skin-derived cells formed more colonies than CNS-derived cells. Inhibitors of specific mediators of the NRAS signaling pathway reduced viability of NRAS mutated cells. The highest effect was obtained with GSK2126458, showing a viability reduction below 50%. CONCLUSIONS: NRAS mutated cells derived from clinical NCM samples are capable of continuous growth as spheroid colonies in vitro and retain their genetic identity. Drugs targeting the NRAS signaling pathway reduce in vitro viability of NCM cells. NCM lesional spheroids represent a new and reliable experimental model of NCM for use in drug testing and mechanistic studies.