bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurogenic Fever after Acute Traumatic Spinal Cord Injury: A Qualitative Systematic Review
Authors: Savage Katherine E. , Oleson Christina V. , Schroeder Gregory D. , Sidhu Gursukhman S. , Vaccaro Alexander R.
Published: January 2016

Study Design

Systematic review.

Objective

To determine the incidence, pathogenesis, and clinical outcomes related to neurogenic fevers following traumatic spinal cord injury (SCI).

Methods

A systematic review of the literature was performed on thermodysregulation secondary to acute traumatic SCI in adult patients. A literature search was performed using PubMed (MEDLINE), Cochrane Central Register of Controlled Trials, and Scopus. Using strict inclusion and exclusion criteria, seven relevant articles were obtained.

Results

The incidence of fever of all origins (both known and unknown) after SCI ranged from 22.5 to 71.7% with a mean incidence of 50.6% and a median incidence of 50.0%. The incidence of fever of unknown origin (neurogenic fever) ranged from 2.6 to 27.8% with a mean incidence of 8.0% and a median incidence of 4.7%. Cervical and thoracic spinal injuries were more commonly associated with fever than lumbar injuries. In addition, complete injuries had a higher incidence of fever than incomplete injuries. The pathogenesis of neurogenic fever after acute SCI is not thoroughly understood.

Conclusion

Neurogenic fevers are relatively common following an acute SCI; however, there is little in the scientific literature to help physicians prevent or treat this condition. The paucity of research underscored by this review demonstrates the need for further studies with larger sample sizes, focusing on incidence rate, clinical outcomes, and pathogenesis of neurogenic fever following acute traumatic SCI.
Recommended direct simulation Monte Carlo collision model parameters for modeling ionized air transport processes
Authors: Swaminathan-Gopalan Krishnan , Stephani Kelly A.
Published: February 2016

A systematic approach for calibrating the direct simulation Monte Carlo (DSMC) collision model parameters to achieve consistency in the transport processes is presented. The DSMC collision cross section model parameters are calibrated for high temperature atmospheric conditions by matching the collision integrals from DSMC against ab initio based collision integrals that are currently employed in the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) and Data Parallel Line Relaxation (DPLR) high temperature computational fluid dynamics solvers. The DSMC parameter values are computed for the widely used Variable Hard Sphere (VHS) and the Variable Soft Sphere (VSS) models using the collision-specific pairing approach. The recommended best-fit VHS/VSS parameter values are provided over a temperature range of 1000-20 000 K for a thirteen-species ionized air mixture. Use of the VSS model is necessary to achieve consistency in transport processes of ionized gases. The agreement of the VSS model transport properties with the transport properties as determined by the ab initio collision integral fits was found to be within 6% in the entire temperature range, regardless of the composition of the mixture. The recommended model parameter values can be readily applied to any gas mixture involving binary collisional interactions between the chemical species presented for the specified temperature range.
Electrically induced drop detachment and ejection
Authors: Cavalli Andrea , Preston Daniel J. , Tio Evelyn , Martin David W. , Miljkovic Nenad , Wang Evelyn N. , Blanchette Francois , Bush John W. M.
Published: February 2016

A deformed droplet may leap from a solid substrate, impelled to detach through the conversion of surface energy into kinetic energy that arises as it relaxes to a sphere. Electrowetting provides a means of preparing a droplet on a substrate for lift-off. When a voltage is applied between a water droplet and a dielectric-coated electrode, the wettability of the substrate increases in a controlled way, leading to the spreading of the droplet. Once the voltage is released, the droplet recoils, due to a sudden excess in surface energy, and droplet detachment may follow. The process of drop detachment and lift-off, prevalent in both biology and micro-engineering, has to date been considered primarily in terms of qualitative scaling arguments for idealized superhydrophobic substrates. We here consider the eletrically-induced ejection of droplets from substrates of finite wettability and analyze the process quantitatively. We compare experiments to numerical simulations and analyze how the energy conversion efficiency is affected by the applied voltage and the intrinsic contact angle of the droplet on the substrate. Our results indicate that the finite wettability of the substrate significantly affects the detachment dynamics, and so provide new rationale for the previously reported large critical radius for drop ejection from micro-textured substrates.
Linear stability of pressure-driven flow over longitudinal superhydrophobic grooves
Authors: Yu K. H. , Teo C. J. , Khoo B. C.
Published: February 2016

The modal analysis of pressure-driven flows in channels patterned with superhydrophobic surfaces containing periodic grooves and ribs aligned longitudinally to the flow direction has been performed. The effects of shear–free fraction δ and groove-rib spatial period normalized by full-channel height L on the linear flow stability of such flows have been explored. By performing a BiGlobal linear stability analysis via the pseudo-spectral method, such surfaces have been found to potentially exert a stabilizing or destabilizing effect on the base flow, depending predominantly on the normalized groove-rib spacing. For small values of L (i.e., L = 0.01 and 0.02), a stabilizing effect is predicted for flows over longitudinal superhydrophobic grooves, in agreement with the results obtained using a local stability analysis which employs a homogeneous slip condition along the walls. For a moderate value of normalized groove-rib spacing where the groove-rib periodic spacing is one-tenth of the channel height, the presence of longitudinal superhydrophobic grooves leads to flow instabilities at a lower critical Reynolds number. The redistribution of the base flow resulting from the vanishing shear rates along the liquid-gas interface could give rise to an inflectional instability that promotes temporal instability. The effects of patterning the superhydrophobic surfaces on one or both channel walls are also examined.
Observation of Fano line shapes arising from coupling between surface plasmon polariton and waveguide modes
Authors: Hayashi S. , Nesterenko D. V. , Rahmouni A. , Sekkat Z.
Published: February 2016

We demonstrate experimentally the generation of narrow Fano line shapes in planar multilayer structures. The Fano line shape originates from coupling between a high loss surface plasmon polariton mode with a low loss planar waveguide mode. The line shape is shown to depend strongly on the structural parameters that govern the position of the waveguide mode and the coupling strength, and to be in good agreement with results of electromagnetic calculations.
Enhancing the light extraction efficiency of AlGaN deep ultraviolet light emitting diodes by using nanowire structures
Authors: Djavid Mehrdad , Mi Zetian
Published: February 2016

The performance of conventional AlGaN deep ultraviolet light emitting diodes has been limited by the extremely low light extraction efficiency (<10%), due to the unique transverse magnetic (TM) polarized light emission. Here, we show that, by exploiting the lateral side emission, the extraction efficiency of TM polarized light can be significantly enhanced in AlGaN nanowire structures. Using the three-dimensional finite-difference time domain simulation, we demonstrate that the nanowire structures can be designed to inhibit the emission of guided modes and redirect trapped light into radiated modes. A light extraction efficiency of more than 70% can, in principle, be achieved by carefully optimizing the nanowire size, nanowire spacing, and p-GaN thickness.
Ultrasound resolution beats the diffraction limit
Authors: Miller Johanna L.
Published: January 2016

With an acoustic analogue of a Nobel Prize–winning optical technique, researchers can acquire detailed images quickly.
A quantum cascade laser gets a geometric makeover
Authors: Wilson R. Mark
Published: January 2016

A change in the cross section and orientation of the laser’s optical cavity collimates an otherwise highly divergent terahertz-frequency beam.
Volcano research flows from North Korea
Authors: Feder Toni
Published: January 2016

An international team of scientists is studying Mount Paektu to understand its past activity and future hazards.
Sensing deep-ocean temperatures
Authors: Sabra Karim G. , Cornuelle Bruce , Kuperman William A.
Published: January 2016

Though not yet widely implemented, the technique of monitoring the ocean’s warming via changes in the speed of sound through the water is a powerful complement to the more common tools available: free-floating thermometers and altimetry satellites.
The surprising dynamics of rolling rings
Authors: Jalali Mir Abbas , Alam Mohammad-Reza
Published: January 2016

A ring set spinning on a tabletop can display a rolling behavior that a spun coin will never show.
Tensile and fatigue behaviour of Ni–Ni3Si eutectic in situ composites
Authors: Cui C. , Xue T. , Jin Y. , Zhai T.
Published: January 2016

A Ni–Ni3Si composite was fabricated via a eutectic reaction (Ni–Ni3Si) using a rapidly cooled directional solidification technique at a solidification rate of 40 μm s−1. The composite consisted of approximately 62.2% Ni–Si solid solution and 37.8% Ni–Ni3Si eutectic phase in volume. Four-point bend fatigue tests were carried out on the composite. The fatigue strength of the alloy was measured to be 520 MPa (maximum cyclic stress). It was found that the fatigue cracks were preferably initiated in the Ni–Ni3Si eutectic phase, and that the Ni matrix was fractured in a cleavage fashion. It was probably attributed to the high level of supersaturated Si in the Ni matrix, which led to inducing the embrittlement of the Ni matrix.
The Effects of Benefit Timing and Income Fungibility on Food Purchasing Decisions among Supplemental Nutrition Assistance Program Households
Authors: Smith Travis A. , Berning Joshua P. , Yang Xiaosi , Colson Gregory , Dorfman Jeffrey H.
Published: January 2016

The Supplemental Nutrition Assistance Program (SNAP) is the largest nutritional safety net in the United States. Prior research has found that participants have higher consumption shortly after receiving their benefits, followed by lower consumption towards the end of the benefit month. Known as the “SNAP benefit cycle,” this consumption pattern has been found to have negative effects on beneficiaries. We hypothesize two behavioral responses of SNAP participants may work in tandem to drive much of the cycle: (1) short‐run impatience—a higher preference to consume today, and (2) fungibility of income—the degree of substitutability between a SNAP dollar and a cash dollar. Using data from the National Food Acquisition and Purchase Survey (FoodAPS), a newly developed nationally representative survey of daily food acquisitions by SNAP households, we find evidence of both behavioral responses. However, the degree of short‐run impatience and fungibility of income is found to differ significantly across poverty levels and use of grocery lists to plan food purchases. SNAP households could gain from food purchase planning education.
Augmented trial designs for evaluation of principal surrogates
Authors: Gabriel Erin E. , Follmann Dean
Published: January 2016

Observation of counterfactual intermediate responses, and evaluation of them as candidate surrogates, is complicated in a standard randomized trial as half of the responses are systematically missing by design. Although some augmentation procedures exist for obtaining counterfactual responses, they are specific to vaccine trials. We outline extensions to the existing augmentations and suggest augmentations of three trial designs outside the setting of vaccines. We outline the assumptions needed to identify the causal estimands of interest under each augmented design, under which standard likelihood-based methods can be used to evaluate intermediate responses as principal surrogates. Two of these designs, crossover and individual stepped-wedge, allow for the observation of clinical endpoints under both treatment and control for some subset of subjects and can therefore improve efficiency over standard parallel trial designs. The third, the treatment run-in design, allows for the observation of a baseline measure that may be as useful a surrogate as the true counterfactual intermediate response. As the evaluation methods rely on several assumptions, we also outline a remediation analysis, which can be used to help overcome assumption violations. We illustrate our suggested methods in an example from a drug-resistant tuberculosis treatment trial.
Spatio-temporal distribution of euphausiids: an important component to understanding ecosystem processes in the Gulf of Alaska and eastern Bering Sea
Authors: Simonsen Kirsten A. , Ressler Patrick H. , Rooper Christopher N. , Zador Stephani G.
Published: January 2016

Euphausiids (principally Thysanoessa spp.) are found in high abundance in both the eastern Bering Sea (EBS) and the Gulf of Alaska (GOA). They are an important part of these cold-water coastal and pelagic ecosystems as a key prey item for many species, including marine mammals, seabirds, and fish, forming an ecological link between primary production and higher trophic levels. Acoustic-trawl (AT) survey methods provide a means of monitoring euphausiid abundance and distribution over a large spatial scale. Four years of AT and bottom-trawl survey data (2003, 2005, 2011, and 2013) were available from consistently sampled areas around Kodiak Island, including Shelikof Strait, Barnabas Trough, and Chiniak Trough. We identified euphausiid backscatter using relative frequency response and targeted trawling, and created an annual index of abundance for euphausiids. This index has broad application, including use in the stock assessments for GOA walleye pollock (Gadus chalcogrammus) and other species, as an ecosystem indicator, and to inform ecological research. We then used generalized additive models (GAMs) to examine the relationship between relative euphausiid abundance and potential predictors, including pollock abundance, temperature, bottom depth, and primary production. Model results were compared with an updated GAM of euphausiid abundance from the EBS to determine if the factors driving abundance and distribution were consistent between both systems. Temperature was not a strong predictor of euphausiid abundance in the GOA as in the EBS; warmer temperatures and lack of seasonal ice cover in the GOA may be a key difference between these ecosystems. Pollock abundance was significant in both the GOA and the EBS models, but was not a strongly negative predictor of euphausiid abundance in either system, a result not consistent with top-down control of euphausiid abundance.
Prognostic impact of average iodine density assessed by dual-energy spectral imaging for predicting lung tumor recurrence after stereotactic body radiotherapy
Authors: Aoki Masahiko , Hirose Katsumi , Sato Mariko , Akimoto Hiroyoshi , Kawaguchi Hideo , Hatayama Yoshiomi , Fujioka Ichitaro , Tanaka Mitsuki , Ono Shuichi , Takai Yoshihiro
Published: January 2016

The purpose of this study was to investigate the prognostic significance of average iodine density as assessed by dual-energy computed tomography (DE-CT) for lung tumors treated with stereotactic body radiotherapy (SBRT). From March 2011 to August 2014, 93 medically inoperable patients with 74 primary lung cancers and 19 lung metastases underwent DE-CT prior to SBRT of a total dose of 45–60 Gy in 5–10 fractions. Of these 93 patients, nine patients had two lung tumors. Thus, 102 lung tumors were included in this study. DE-CT was performed for pretreatment evaluation. Regions of interest were set for the entire tumor, and average iodine density was obtained using a dedicated imaging software and evaluated with regard to local control. The median follow-up period was 23.4 months (range, 1.5–54.5 months). The median value of the average iodine density was 1.86 mg/cm 3 (range, 0.40–9.27 mg/cm 3 ). Two-year local control rates for the high and low average iodine density groups divided by the median value of the average iodine density were 96.9% and 75.7% ( P = 0.006), respectively. Tumors with lower average iodine density showed a worse prognosis, possibly reflecting a hypoxic cell population in the tumor. The average iodine density exhibited a significant impact on local control. Our preliminary results indicate that iodine density evaluated using dual-energy spectral CT may be a useful, noninvasive and quantitative assessment of radio-resistance caused by presumably hypoxic cell populations in tumors.
Detection of Periodicity Based on Independence Tests – II. Improved Serial Independence Measure
Authors: Zucker Shay
Published: January 2016

We introduce an improvement to a periodicity metric we have introduced in a previous paper. We improve on the Hoeffding-test periodicity metric, using the Blum–Kiefer–Rosenblatt (BKR) test. Besides a consistent improvement over the Hoeffding-test approach, the BKR approach turns out to perform superbly when applied to very short time series of sawtooth-like shapes. The expected astronomical implications are much more detections of RR-Lyrae stars and Cepheids in sparse photometric data bases, and of eccentric Keplerian radial-velocity (RV) curves, such as those of exoplanets in RV surveys.
Genotyping low-grade gliomas among Hispanics
Authors: Cardona Andrés Felipe , Rojas Leonardo , Wills Beatriz , Behaine José , Jiménez Enrique , Hakim Fernando , Useche Nicolás , Bermúdez Sonia , Arrieta Oscar , Mejía Juan Armando , Ramón Juan Fernando , Carranza Hernán , Vargas Carlos , Otero Jorge , González Diego , Rodríguez July , Ortiz León Darío , Cifuentes Hernando , Balaña Carmen
Published: January 2016

Background

Low-grade gliomas (LGGs) are classified by the World Health Organization as astrocytoma (DA), oligodendroglioma (OD), and mixed oligoastrocytoma (OA). TP53 mutation and 1p19q codeletion are the most-commonly documented molecular abnormalities. Isocitrate dehydrogenase (IDH) 1/2 mutations are frequent in LGGs; however, IDH-negative gliomas can also occur. Recent research suggests that ATRX plays a significant role in gliomagenesis.

Methods

We investigated p53 and Olig2 protein expression, and MGMT promoter methylation, 1p19q codeletion, IDH, and ATRX status in 63 Colombian patients with LGG. The overall survival (OS) rate was estimated and compared according to genotype.

Results

The most common histology was DA, followed by OD and OA. IDH1/2 mutations were found in 57.1% and MGMT+ (positive status of MGMT promoter methylation methyl-guanyl-methyl-transferase gene) in 65.1% of patients, while overexpression of p53 and Olig2 was present in 30.2% and 44.4%, respectively, and 1p19q codeletion in 34.9% of the patients. Overexpression of ATRX was analyzed in 25 patients, 16% tested positive and were also mutations in isocitrate dehydrogenase and negative 1p19q-codelition. The median follow-up was 15.8 months (95% CI, 7.6–42.0) and OS was 39.2 months (95% CI, 1.3–114). OS was positively and significantly affected by MGMT+, 1p19q codeletion, surgical intervention extent, and number of lobes involved. Multivariate analysis confirmed that MGMT methylation status and 1p19q codeletion affected OS.

Conclusions

This is the first study evaluating the molecular profile of Hispanic LGG patients. Findings confirmed the prognostic relevance of MGMT methylation and 1p19q codeletion, but do not support IDH1/2 mutation as a relevant marker. The latter may be explained by sample size and selection bias. ATRX alterations were limited to patients with DA and were mutations in isocitrate dehydrogenase and negative 1p19q-codelition.
Minocycline-Induced Cutaneous Hyperpigmentation in an Orthopedic Patient Population
Authors: Hanada Yuri , Berbari Elie F. , Steckelberg James M.
Published: January 2016

Background.  The objectives of this study were to estimate the incidence and evaluate risk factors for development of minocycline-induced cutaneous hyperpigmentation in patients with orthopedic infections.

Methods.  Patients with orthopedic infections evaluated at Mayo Clinic (Rochester, MN) and treated with minocycline from 1 January 2002 to 31 December 2011 were retrospectively identified. Long-term minocycline suppression was defined as daily minocycline use for at least 3 months. A proportional hazards model was used to evaluate potential risk factors.

Results.  Of 291 patients receiving long-term minocycline suppression, 54% (156 of 291) developed hyperpigmentation after a mean follow-up of 4.8 years (range, 0.3–13.2 years); 88% involved blue-gray pigmentation of normal skin that appeared most commonly in the lower (75%) and upper extremities (44%). The mean duration of minocycline therapy before hyperpigmentation was 1.5 years (range, 0.1–9 years) with a mean cumulative dosage of 107.3 g (range, 8.6–657 g). Notable risk factors include a history of vitamin D deficiency (relative risk [RR], 6.29; 95% confidence interval [CI], 1.91–15.27; P = .0052), presence of a shoulder prosthesis (RR, 3.2; 95% CI, 1.23–6.56; P = .0062), noncirrhotic liver pathology (RR, 3.63; 95% CI, 1.11–8.75; P = .0359), and use of a concurrent medication also known to cause hyperpigmentation (RR, 4.75; 95% CI, 1.83–10.1; P = .0029).

Conclusions.  Hyperpigmentation associated with the use of long-term minocycline suppression in patients with orthopedic infections is common.
Immune Control Despite Protracted Lymphopenia After Chemoradiation in an Elite Controller
Authors: Reiss Kim A. , Jackson Dvone C. , Piotrowski Anna , Grossman Stuart , Blankson Joel N.
Published: January 2016

Elite controllers are human immunodeficiency virus-1–positive individuals capable of sustaining undetectable viral loads without treatment. We present the case of an elite controller diagnosed with extensive stage small cell lung cancer who maintained a viral load of <20 copies/mL despite the development of severe treatment-related lymphopenia.
Chao Yuanfang: Imperial Physician of the Sui Dynasty and an Early Pertussis Observer?
Authors: Liang Yan , Salim Abdulbaset M. , Wu Wendy , Kilgore Paul E.
Published: January 2016

Early Chinese texts contain extensive disease descriptions, including various texts that contain descriptions of modern-day conditions. During the Sui Dynasty, a leading scholar, Chao Yuanfang, may have authored a leading treatise 1400 years ago. Although these texts are the subject of ongoing research, evidence suggests that a clinical syndrome consistent with pertussis was observed in ancient China.
Use of Intensive Care Services for Medicare Beneficiaries Undergoing Major Surgical Procedures
Authors: Wunsch Hannah , Gershengorn Hayley B. , Cooke Colin R. , Guerra Carmen , Angus Derek C. , Rowe John W. , Li Guohua
Published: January 2016

AbstractAbstract

For a large cohort of patients undergoing selected major surgical procedures, there was a wide variation in intensive care unit utilization for each procedure, with no relation to mortality. Greater systematic use of intensive care for older surgical patients in the United States undergoing selected major surgeries does not improve survival outcomes.

Supplemental Digital Content is available in the text.

Background

Use of intensive care after major surgical procedures and whether routinely admitting patients to intensive care units (ICUs) improve outcomes or increase costs is unknown.

Methods

The authors examined frequency of admission to an ICU during the hospital stay for Medicare beneficiaries undergoing selected major surgical procedures: elective endovascular abdominal aortic aneurysm (AAA) repair, cystectomy, pancreaticoduodenectomy, esophagectomy, and elective open AAA repair. The authors compared hospital mortality, length of stay, and Medicare payments for patients receiving each procedure in hospitals admitting patients to the ICU less than 50% of the time (low use), 50 to 89% (moderate use), and 90% or greater (high use), adjusting for patient and hospital factors.

Results

The cohort ranged from 7,878 patients in 162 hospitals for esophagectomies to 69,989 patients in 866 hospitals for endovascular AAA. Overall admission to ICU ranged from 35.6% (endovascular AAA) to 71.3% (open AAA). Admission to ICU across hospitals ranged from less than 5% to 100% of patients for each surgical procedure. There was no association between hospital use of intensive care and mortality for any of the five surgical procedures. There was a consistent association between high use of intensive care with longer length of hospital stay and higher Medicare payments only for endovascular AAA.

Conclusions

There is little consensus regarding the need for intensive care for patients undergoing major surgical procedures and no relationship between a hospital’s use of intensive care and hospital mortality. There is also no consistent relationship across surgical procedures between use of intensive care and either length of hospital stay or payments for care.
Effect of Inhalational Anesthetics and Positive-pressure Ventilation on Ultrasound Assessment of the Great Vessels
Authors: Lin Elaina E. , Chen Aaron E. , Panebianco Nova , Conlon Thomas , Ju Na Rae , Carlson Dustin , Kopenitz Jason , Nishisaki Akira
Published: January 2016

AbstractAbstract

Inhalational anesthesia decreased the inferior vena cava (IVC)/aorta ratio but did not change the IVC diameter in response to respiratory variation in healthy children receiving general anesthesia. The initiation of positive-pressure ventilation significantly increased the IVC/aorta ratio and decreased the IVC diameter in response to respiratory variation. There was no change in the IVC/aorta ratio or the IVC diameter in response to respiratory variation with subsequent incremental increases in peak inspiratory pressure or positive end-expiratory pressure.

Background

Bedside ultrasound has emerged as a rapid, noninvasive tool for assessment and monitoring of fluid status in children. The inferior vena cava (IVC) varies in size with changes in blood volume and intrathoracic pressure, but the magnitude of change to the IVC with inhalational anesthetic and positive-pressure ventilation (PPV) is unknown.

Methods

Prospective observational study of 24 healthy children aged 1 to 12 yr scheduled for elective surgery. Ultrasound images of the IVC and aorta were recorded at five time points: awake; spontaneous ventilation with sevoflurane by mask; intubated with peak inspiratory pressure/positive end-expiratory pressure of 15/0, 20/5, and 25/10 cm H2O. A blinded investigator measured IVC/aorta ratios (IVC/Ao) and changes in IVC diameter due to respiratory variation (IVC-RV) from the recorded videos.

Results

Inhalational anesthetic decreased IVC/Ao (1.1 ± 0.3 vs. 0.6 ± 0.2; P < 0.001) but did not change IVC-RV (median, 43%; interquartile range [IQR], 36 to 58% vs. 46%; IQR, 36 to 66%; P > 0.99). The initiation of PPV increased IVC/Ao (0.64 ± 0.21 vs. 1.16 ± 0.27; P < 0.001) and decreased IVC-RV (median, 46%; IQR, 36 to 66% vs. 9%; IQR, 4 to 14%; P < 0.001). There was no change in either IVC/Ao or IVC-RV with subsequent incremental increases in peak inspiratory pressure/positive end-expiratory pressure (P > 0.99 for both).

Conclusions

Addition of inhalational anesthetic affects IVC/Ao but not IVC-RV, and significant changes in IVC/Ao and IVC-RV occur with initiation of PPV in healthy children. Clinicians should be aware of these expected vascular changes when managing patients. Establishing these IVC parameters will enable future studies to better evaluate these measurements as tools for diagnosing hypovolemia or predicting fluid responsiveness.
Variations in the Use of Perioperative Multimodal Analgesic Therapy
Authors: Ladha Karim S. , Patorno Elisabetta , Huybrechts Krista F. , Liu Jun , Rathmell James P. , Bateman Brian T.
Published: January 2016

AbstractAbstract

In a review of nearly 800,000 patients undergoing four common major surgical procedures between 2007 and 2014, the probability of receiving multimodal analgesia was high (90%). There was large variability among hospitals in the use of multimodal analgesia, which could not be accounted for by patient or hospital characteristics.

Supplemental Digital Content is available in the text.

Background

Practice guidelines for perioperative pain management recommend that multimodal analgesic therapy should be used for all postsurgical patients. However, the proportion of patients who actually receive this evidence-based approach is unknown. The objective of this study was to describe hospital-level patterns in the utilization of perioperative multimodal analgesia.

Methods

Data for the study were obtained from the Premier Research Database. Patients undergoing below-knee amputation, open lobectomy, total knee arthroplasty, and open colectomy between 2007 and 2014 were included in the analysis. Patients were considered to have multimodal therapy if they received one or more nonopioid analgesic therapies. Mixed-effects logistic regression models were used to estimate the hospital-specific frequency of multimodal therapy use while adjusting for the case mix of patients and hospital characteristics and accounting for random variation.

Results

The cohort consisted of 799,449 patients who underwent a procedure at 1 of 315 hospitals. The mean probability of receiving multimodal therapy was 90.4%, with 95% of the hospitals having a predicted probability between 42.6 and 99.2%. A secondary analysis examined whether patients received two or more nonopioid analgesics, which gave an average predicted probability of 54.2%, with 95% of the hospitals having a predicted probability between 9.3 and 93.2%.

Conclusions

In this large nationwide sample of surgical admissions in the United States, the authors observed tremendous variation in the utilization of multimodal therapy not accounted for by patient or hospital characteristics. Efforts should be made to identify why there are variations in the use of multimodal analgesic therapy and to promote its adoption in appropriate patients.
Surgical Site Infections in Patients With Type 3 Open Fractures: Comparing Antibiotic Prophylaxis With Cefazolin Plus Gentamicin Versus Piperacillin/Tazobactam
Authors: Redfern Jenessa , Wasilko Scott M. , Groth Meghan E. , McMillian Wesley D. , Bartlett Craig S.
Published: January 2016

Objectives:

The purpose of this study was to compare rates of surgical site infection (SSI) in patients with type 3 open fractures who had received cefazolin plus gentamicin versus piperacillin/tazobactam for antibiotic prophylaxis.

Design:

Retrospective cohort study.

Setting:

Level 1 trauma center.

Patients:

Seven hundred sixty-six patients admitted between January 1, 2004, and December 31, 2012, with open fractures were identified using the National Trauma Data Bank by searching International Classification of Diseases, Ninth Revision (ICD-9) codes. Electronic medical record review revealed 134 patients with type 3 open fractures, of which 72 were included in the final analysis.

Intervention:

Administration of cefazolin plus gentamicin or piperacillin/tazobactam for type 3 open fracture antibiotic prophylaxis.

Main Outcome Measurements:

SSI, nonunion, death, and rehospitalization rates at 1 year.

Results:

Surgical site infection at 1 year occurred in 12 of 37 patients (32.4%) in the cefazolin plus gentamicin group and 11 of 35 patients (31.4%) in the piperacillin/tazobactam group (P = 1.000). Nonunion, death, and rehospitalization rates at 1 year were similar between the 2 groups. Although there was no statistically significant difference in SSI at 30 days between groups, the rate was higher in the cefazolin plus gentamicin group (21.6% vs. 11.4%; P = 0.246).

Conclusions:

At our institution, use of piperacillin/tazobactam as compared with cefazolin plus gentamicin for antibiotic prophylaxis in patients with type 3 open fractures showed similar rates of SSI, nonunion, mortality, and rehospitalization at 1 year after injury.

Level of Evidence:

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Endothelin-1 in the tumor microenvironment correlates with melanoma invasion
Authors: Chiriboga Luis , Meehan Shane , Osman Iman , Glick Michael , de la Cruz Gelo , Howell Brittny S. , Friedman-Jiménez George , Schneider Robert J. , Jamal Sumayah
Published: January 2016

Endothelin-1 (ET-1) is a vasoactive peptide that also plays a role in the tanning response of the skin. Animal and cell culture studies have also implicated ET-1 in melanoma progression, but no association studies have been performed to link ET-1 expression and melanoma in humans. Here, we present the first in-vivo study of ET-1 expression in pigmented lesions in humans: an ET-1 immunohistochemical screen of melanocytic nevi, melanoma in situ lesions, invasive melanomas, metastatic melanomas, and blue nevi was performed. Twenty-six percent of melanocytic nevi and 44% of melanoma in situ lesions demonstrate ET-1 expression in the perilesional microenvironment, whereas expression in nevus or melanoma cells was rare to absent. In striking contrast, 100% of moderately to highly pigmented invasive melanomas contained numerous ET-1-positive cells in the tumor microenvironment, with 79% containing ET-1-positive melanoma cells, confirmed by co-staining with melanoma tumor marker HMB45. Hypopigmented invasive melanomas had reduced ET-1 expression, suggesting a correlation between ET-1 expression and pigmented melanomas. ET-1-positive perilesional cells were CD68-positive, indicating macrophage origin. Sixty-two percent of highly pigmented metastatic melanomas demonstrated ET-1 expression in melanoma cells, in contrast to 28.2% of hypopigmented specimens. Eighty-nine percent of benign nevi, known as blue nevi, which have a dermal localization, were associated with numerous ET-1-positive macrophages in the perilesional microenvironment, but no ET-1 expression was detected in the melanocytes. We conclude that ET-1 expression in the microenvironment increases with advancing stages of melanocyte transformation, implicating a critical role for ET-1 in melanoma progression, and the importance of the tumor microenvironment in the melanoma phenotype.
COTTON-WOOL SPOTS AFTER USE OF MACITENTAN FOR PULMONARY ARTERIAL HYPERTENSION
Authors: Khan Mohammed Ali , Ho Allen C. , Spirn Marc J.
Published: January 2016

Purpose:

To report a case of transient, bilateral cotton spots after initiation of macitentan, an endothelin receptor antagonist used for the treatment of pulmonary arterial hypertension.

Methods:

Case report.

Results:

A 76-year-old woman with WHO Class IIIb pulmonary arterial hypertension was referred for evaluation of bilateral cotton-wool spots 1 week after starting macitentan therapy. The patient was asymptomatic and visual acuity was 20/25 in each eye. Fluorescein angiography and optical coherence tomography were completed. Given lack of symptoms and alternative treatment options, the patient was observed closely. The cotton-wool spots resolved 8 weeks after presentation and visual acuity remained stable at 20/25. Throughout the observation period, average mean arterial pressure was within normal limits at 84.8.

Conclusion:

In patients using endothelin receptor antagonists, medication side effect should be considered in the differential diagnosis of cotton-wool spots.
RUPTURED RETINAL ARTERIAL MACROANEURYSM ON THE OPTIC DISK
Authors: Rahimy Ehsan , Doyle Brian C. , Brown Gary C.
Published: January 2016

Purpose:

To describe multimodal imaging findings in a patient presenting with an occult optic disk macroaneurysm.

Methods:

A 54-year-old woman presented with decreased vision in the right eye secondary to preretinal, intraretinal, and optic disk hemorrhage.

Results:

Ancillary fluorescein angiography revealed evidence of an occult optic disk macroaneurysm that was not realized on fundoscopic examination. Subsequent optical coherence tomography obtained once the hemorrhage resolved demonstrated a thrombosed macroaneurysm with an adjacent ring of exudate.

Conclusion:

Detection of optic disk macroaneurysms at the time of initial presentation can be difficult because of concurrent overlying hemorrhage, but should nevertheless be kept in the differential when macular hemorrhage in multiple retinal layers is observed.
The Ocular Hypotensive Efficacy of Topical Fasudil, a Rho-Associated Protein Kinase Inhibitor, in Patients With End-Stage Glaucoma
Authors: Pakravan Mohammad , Beni Afsaneh Naderi , Ghahari Elham , Varshochian Reyhaneh , Yazdani Shahin , Esfandiari Hamed , Ahmadieh Hamid
Published: January 2016

To investigate the effects of topical administration of a selective Rho-associated kinase (ROCK) inhibitor, fasudil 0.5% and 1.2% in glaucomatous patients. In this interventional case series study, 4 eyes of 4 patients with unilateral end-stage primary open-angle glaucoma and no light perception vision were assigned to receive topical fasudil 0.5% (in 3 eyes) or 1.2% (in 1 eye) ophthalmic solution twice daily for 8 weeks. At weeks 1, 2, 3, 4, and 8, intraocular pressure (IOP) and adverse events were evaluated. Baseline mean IOP was 53.5 ± 3.4 mm Hg and mean IOP reductions of the last visit were −8.25 ± 1.2 mm Hg at 2 hours and −8.75 ± 2.2 mm Hg at 4 hours. Mean IOP reductions were clinically and statistically significant with 0.5% and 1.2% fasudil and peak effects occurred 2–4 hours after application (P = 0.0002). The largest IOP reductions were produced by 1.2% fasudil (up to −12 mm Hg). Conjunctival hyperemia was found in 1 patient with 1.2% fasudil. Topical administration of fasudil in end-stage primary open-angle glaucoma patients, caused reduction in IOP and was well tolerated. ROCK inhibitors could be considered as a candidate for glaucoma therapy in future.
Thirty Years of Cystocele/Rectocele Repair in the United States
Authors: Stewart James R. , Hamner Jennifer J. , Heit Michael H.
Published: January 2016

Objective

A growing body of evidence suggests an increased role for apical support in the treatment of pelvic organ prolapse regardless of phenotype. The objective of this study was to determine whether changes in cystocele/rectocele diagnosis and surgical management for the last 30 years reflect this changing paradigm.

Methods

Data from the National Hospital Discharge Survey were mined from 1979 to 2009 for diagnosis and procedure codes. Records were categorized according to predefined combinations of diagnosis and procedure codes and weighted according to the National Hospital Discharge Survey data set. Pearson χ2 test was used to evaluate the changes in population proportions during the study interval.

Results

The proportion of isolated cystocele/rectocele diagnoses decreased from 1979 to 2009 (56.5%, n = 88,548, to 34.8%, n = 31,577). The proportion of isolated apical defect diagnoses increased from 1979 to 2009 (38.4%, n = 60,223, to 60.8%, n = 55,153). There was a decrease in the frequency of isolated cystocele/rectocele repair procedures performed from 1979 to 2009 (96.3%, n = 150,980, to 67.7%, n = 61,444), whereas there was an increase in isolated apical defect repair procedures (2.5%, n = 3929, to 22.5%, n = 20,450). The proportion of cystocele/rectocele plus apical defect procedures also increased (1.2%, n = 1879, to 9.7%, n = 8806). Furthermore, 87.0% of all studied diagnostic groups were managed by cystocele/rectocele repair alone.

Conclusions

Surgeons have responded to the increased contribution of apical support defects to cystocele/rectocele by modifying their diagnostic coding practices. Unfortunately, their surgical choices remain largely rooted in an older paradigm.
Vaginal Expression of LOXL1 in Premenopausal and Postmenopausal Women With Pelvic Organ Prolapse
Authors: Kow Nathan , Ridgeway Beri , Kuang Mei , Butler Robert S. , Damaser Margot S.
Published: January 2016

Objectives

This study aimed to compare cellular expression of lysyl oxidase-like 1 (LOXL1), a key enzyme in elastin metabolism, of premenopausal women with pelvic organ prolapse (POP) compared with premenopausal controls without POP and postmenopausal women with POP. In addition, we examined whether variation of LOXL1 expression was dependent on biopsy site.

Methods

A standardized protocol was utilized to obtain vaginal biopsies from 30 women (10 premenopausal POP, 10 postmenopausal POP, and 10 premenopausal non-POP). Expression levels of messenger RNA (mRNA) and protein of LOXL1 were determined using real-time quantitative polymerase chain reactions and enzyme-linked immunosorbant assays. Analysis was performed to determine if there were differences between group or biopsy site.

Results

Significant differences in LOXL1 mRNA expression were found between patient groups (P = 0.0033). LOXL1 mRNA expression (relative to 18S) was upregulated in the postmenopausal POP group (54.5 ± 14.7) compared with the premenopausal POP group (5.2 ± 14.7, P = 0.0034) and the premenopausal non-POP group (23 ± 18, P = 0.0359). No significant differences in LOXL1 protein expression (nanogram/milliliter per microgram total protein) were seen between groups (premenopausal POP, 3.2 × 10−3 ± 6.3 × 10−4; postmenopausal POP, 4.3 × 10−3 ± 6.3 × 10−4; premenopausal non-POP, 5.0 × 10−3 ± 7.7 × 10−4; P = 0.15). No differences in mRNA expression were seen between sites (P = 0.74), but significant variation was noted in protein expression (P = 0.001).

Conclusions

Premenopausal and postmenopausal women with POP exhibit differential expression of LOXL1 suggesting different pathways in the pathogenesis of POP. The role of biopsy location on LOXL1 expression requires further investigation.
A Novel Cystometric Model of Pelvic Floor Dysfunction After Rabbit Pelvic Floor Noxious Electrical Stimulation
Authors: Dobberfuhl Amy D. , Spettel Sara , Schuler Catherine , Dubin Andrew H. , Levin Robert M. , De Elise J.B.
Published: January 2016

Objectives

Although a relationship between pelvic floor dysfunction and lower urinary tract symptoms is described in the literature, the mechanism and pathways need further characterization. We developed an animal model of pelvic floor dysfunction after noxious stimulation of the pubococcygeus (PC) muscle.

Methods

Fifteen female adult rabbits were evaluated with cystometry (CMG) and electromyography (EMG) recordings from the PC muscle. Cystometry/EMG was performed before and after treatment animal (n = 11) received noxious pelvic floor electrical stimulation through the PC EMG electrode, and controls (n = 4) underwent sham needle placement. Two animals underwent S3 dorsal rhizotomy to demonstrate that the observed results required afferent innervation.

Results

Voiding changes were demonstrated in 9 of 11 rabbits after stimulation. Most of the rabbits (7/9) exhibited a prolonged-dysfunctional voiding pattern with larger capacity (mean, 17 mL [SEM, ±8 mL]), longer intercontractile interval (227% [SEM, ±76%]) and duration (163% [SEM, ±20%]), and increased postvoid residual (24 mL [SEM, ±6 mL]). The remaining dysfunctional rabbits (2/9) exhibited an overactive-dysfunctional voiding pattern with lower capacity (−26 mL [SEM, ±6 mL]), shortened intercontractile interval (16% [SEM, ±9%]) and duration (56% [SEM, ±30%]), and decreased postvoid residual (−27 mL [SEM, ±6 mL]). Nonresponder rabbits (2/11) were relatively unchanged in their micturition cycles after stimulation. Rhizotomy animals were acontractile and filled until overflow incontinence occurred.

Conclusions

Using noxious electrical stimulation of the pelvic musculature, we were able to produce an animal model of pelvic floor dysfunction in most rabbits as hallmarked by a larger bladder capacity, an increased intercontractile interval, and prolonged contraction duration.
Impact of Pelvic Floor Physical Therapy on Quality of Life and Function After Obstetric Anal Sphincter Injury: A Randomized Controlled Trial
Authors: Oakley Susan H. , Ghodsi Vivian C. , Crisp Catrina C. , Estanol Maria Victoria , Westermann Lauren B. , Novicki Kathleen M. , Kleeman Steven D. , Pauls Rachel N.
Published: January 2016

Objectives

There is no standard of care for women sustaining an obstetric anal sphincter injury (OASIS). We sought to determine whether pelvic floor physical therapy (PFPT) would improve the quality of life and function in women 12 weeks after OASIS.

Methods

This institutional review board–approved randomized trial enrolled primiparous women 2 weeks after delivery complicated by OASIS. After informed consent, all subjects underwent vaginal electromyography and anorectal manometry and completed validated questionnaires; measures were repeated for all subjects at 12 weeks after delivery. The intervention arm completed 4 PFPT sessions. The primary outcome was a change in the Fecal Incontinence Quality of Life.

Results

Three hundred four women were screened; 250 were excluded, and 54 were randomized. After four were lost to follow-up, analysis included 27 in the intervention arm and 23 in the control arm. Overall, mean age was 29.8 ± 4.7 years, and there were no demographic differences between groups.

Fecal Incontinence Quality of Life domain scores showed improvement for both groups from baseline to 12 weeks for coping (P = 0.006) and depression (P = 0.009); however, there was no difference in domain scores between groups. For the secondary outcome of anorectal manometry, squeezing pressure improved for all subjects (P = 0.035) from baseline to 12 weeks. Vaginal EMG strength (microvolts) increased for all subjects in measures of rest average (P < 0.000), rapid peak (P = 0.006), and work average (P < 0.000), with no difference based on therapeutic arm.

Conclusions

All women showed improvements in quality of life and function at 12 weeks after delivery, regardless of treatment allocation. Further study is needed to determine whether PFPT provides a significant benefit to women having OASIS.
MetaFlow: Metagenomic profiling based on whole-genome coverage analysis with min-cost flows
Authors: Sobih Ahmed , Tomescu Alexandru I. , Mäkinen Veli
Published: January 2016

High-throughput sequencing (HTS) of metagenomes is proving essential in understanding the environment and diseases. State-of-the-art methods for discovering the species and their abundances in an HTS metagenomic sample are based on genome-specific markers, which can lead to skewed results, especially at species level. We present MetaFlow, the first method based on coverage analysis across entire genomes that also scales to HTS samples. We formulated this problem as an NP-hard matching problem in a bipartite graph, which we solved in practice by min-cost flows. On synthetic data sets of varying complexity and similarity, MetaFlow is more precise and sensitive than popular tools such as MetaPhlAn, mOTU, GSMer and BLAST, and its abundance estimations at species level are two to four times better in terms ofℓ1-norm. On a real human stool data set, MetaFlow identifiesB.uniformisas most predominant, in line with previous human gut studies, whereas marker-based methods report it as rare. MetaFlow is freely available athttp://cs.helsinki.fi/gsa/metaflow