bluuebunny/crossref_metadata_2025 huggingface dataset:
Case report of successful low-dose, ultra-slow infusion thrombolysis of prosthetic mitral valve thrombosis in a high risk patient after redo-mitral valve replacement
Authors: Kapos Ioannis , Fuchs Tobias , Tanner Felix C
Published: March 2020

Background

An increase in transvalvular pressure gradient of prosthetic valve should always raise suspicion for obstructive valve thrombosis. A multimodality diagnostic approach including transthoracic echocardiography, transoesophageal echocardiography (TOE), cinefluoroscopy, or computed tomography (CT) is necessary for a prompt diagnosis. The management of mechanical prosthetic valve thrombosis (PVT) is high risk in any therapeutic option taken. Emergency valve replacement is recommended for critically ill patients. Fibrinolysis is an alternative for patients with contraindication to surgery or if surgery is not immediately available.

Case summary

A 52-year-old woman presented with symptoms and signs of cardiac congestion. On laboratory, brain natriuretic peptide was elevated and international normalized ratio (INR) was in subtherapeutic range. She underwent a mitral valve replacement with mechanical prosthesis 7 months before, because of a significant residual regurgitation after repair on the same year. TOE revealed severe stenosis of the prosthesis with immobile anterior disc but there was no mass present. CT revealed a minor lesion at the hinge points of the prosthesis without involvement of the ring, suggestive for thrombus. The initial fruitless management with intravenous (i.v) heparin in high therapeutic range was followed by a successful ‘low-dose, ultra-slow’ fibrinolysis.

Discussion

CT may help differentiate thrombus vs. pannus. The acute onset of symptoms, inadequate anticoagulation, and restricted leaflet motion increased the suspicion for PVT. The current European guidelines propose normal dose fibrinolysis. We performed ‘low-dose, ultra-slow’ fibrinolysis due to lower bleeding risk with successful results. Low dose should be considered as alternative to normal dose fibrinolysis or urgent surgery.
Implementing Package of Essential Non-communicable Disease Interventions in the Republic of Moldova—a feasibility study
Authors: Laatikainen Tiina , Inglin Laura , Collins Dylan , Ciobanu Angela , Curocichin Ghenadie , Salaru Virginia , Zatic Tatiana , Anisei Angela , Chiosa Diana , Munteanu Maria , Alexa Zinaida , Farrington Jill
Published: March 2020

Background

The aim of this study is to determine the feasibility of implementing and evaluating the World Health Organization Package of Essential Non-communicable Disease Interventions (WHO PEN) approach in primary healthcare in the Republic of Moldova.

Methods

According to our published a priori methods, 20 primary care clinics were randomized to 10 intervention and 10 control clinics. The intervention consisted of implementation of adapted WHO PEN guidelines and structured training for health workers; the control clinics continued with usual care. Data were gathered from paper-based patient records in July 2017 and August 2018 resulting in a total of 1174 and 995 patients in intervention and control clinics at baseline and 1329 and 1256 at follow-up. Pre-defined indicators describing assessment of risk factors and total cardiovascular risk, prescribing medications and treatment outcomes were calculated. Differences between baseline and follow-up as well as between intervention and control clinics were calculated using logistic and linear regression models and by assessing interaction effects.

Results

Improvements were seen in recording smoking status, activity to measure HbA1c among diabetes patients and achieving control in hypertension treatment. Improvement was also seen in identification of patients with hypertension or diabetes. Less improvement or even deterioration was seen in assessing total risk or prescribing statins for high-risk patients.

Conclusions

It is feasible to evaluate the quality and management of patients with non-communicable diseases in low-resource settings from routine data. Modest improvements in risk factor identification and management can be achieved in a relatively short period of time.
Sensitivity analysis of gravity gradient inversion of the Moho depth—a case example for the Amazonian Craton
Authors: Haas Peter , Ebbing Jörg , Szwillus Wolfgang
Published: March 2020

We present a novel approach for linearized gravity inversion to estimate the Moho depth, which allows the use of any gravitational component instead of the vertical gravity component only. The inverse problem is solved with the Gauss–Newton algorithm and the gravitational field of the undulating Moho depth is calculated with tesseroids. Hereby, the density contrast can be laterally variable by using information from seismological regionalization. Our approach is illustrated with a synthetic example, which we use to explore different regularization parameters. The vertical gravity gradient gzz provides the most reasonable results with appropriate parameters. As a case example, we invert for the Moho depth of the Amazonian Craton and its surroundings. The results are constrained by estimates from active seismic measurements. Our new Moho depth model correlates to tectonic domains and is in agreement with previous models. The estimated density contrasts of the tectonic domains agree well with the lithospheric architecture and show with 300–450 kg m–3 lower density contrasts for continental domains, whereas the oceans reveal a density contrast of 450–500 kg m–3. The wider range of estimated density contrast for the continent reflects uncertainties in Precambrian Fold Belts that arise from its small gravity signal. Our results demonstrate that a variable density contrast at the Moho depth is a valuable enhancement for gravity inversion.
A single Rayleigh mode may exist with multiple values of phase-velocity at one frequency
Authors: Forbriger Thomas , Gao Lingli , Malischewsky Peter , Ohrnberger Matthias , Pan Yudi
Published: March 2020

Other than commonly assumed in seismology, the phase velocity of Rayleigh waves is not necessarily a single-valued function of frequency. In fact, a single Rayleigh mode can exist with three different values of phase velocity at one frequency. We demonstrate this for the first higher mode on a realistic shallow seismic structure of a homogeneous layer of unconsolidated sediments on top of a half-space of solid rock (LOH). In the case of LOH a significant contrast to the half-space is required to produce the phenomenon. In a simpler structure of a homogeneous layer with fixed (rigid) bottom (LFB) the phenomenon exists for values of Poisson’s ratio between 0.19 and 0.5 and is most pronounced for P-wave velocity being three times S-wave velocity (Poisson’s ratio of 0.4375). A pavement-like structure (PAV) of two layers on top of a half-space produces the multivaluedness for the fundamental mode. Programs for the computation of synthetic dispersion curves are prone to trouble in such cases. Many of them use mode-follower algorithms which loose track of the dispersion curve and miss the multivalued section. We show results for well established programs. Their inability to properly handle these cases might be one reason why the phenomenon of multivaluedness went unnoticed in seismological Rayleigh wave research for so long. For the very same reason methods of dispersion analysis must fail if they imply wave number kl(ω) for the lth Rayleigh mode to be a single-valued function of frequency ω. This applies in particular to deconvolution methods like phase-matched filters. We demonstrate that a slant-stack analysis fails in the multivalued section, while a Fourier–Bessel transformation captures the complete Rayleigh-wave signal. Waves of finite bandwidth in the multivalued section propagate with positive group-velocity and negative phase-velocity. Their eigenfunctions appear conventional and contain no conspicuous feature.
Linking the performance of a data-limited empirical catch rule to life-history traits
Authors: Fischer Simon H , De Oliveira José A A , Kell Laurence T
Published: March 2020

Worldwide, the majorities of fish stocks are data-limited and lack fully quantitative stock assessments. Within ICES, such data-limited stocks are currently managed by setting total allowable catch without the use of target reference points. To ensure that such advice is precautionary, we used management strategy evaluation to evaluate an empirical rule that bases catch advice on recent catches, information from a biomass survey index, catch length frequencies, and MSY reference point proxies. Twenty-nine fish stocks were simulated covering a wide range of life histories. The performance of the rule varied substantially between stocks, and the risk of breaching limit reference points was inversely correlated to the von Bertalanffy growth parameter k. Stocks with k>0.32 year−1 had a high probability of stock collapse. A time series cluster analysis revealed four types of dynamics, i.e. groups with similar terminal spawning stock biomass (collapsed, BMSY, 2BMSY, 3BMSY). It was shown that a single generic catch rule cannot be applied across all life histories, and management should instead be linked to life-history traits, and in particular, the nature of the time series of stock metrics. The lessons learnt can help future work to shape scientific research into data-limited fisheries management and to ensure that fisheries are MSY compliant and precautionary.
Comparative digestibility of polysaccharide-complexed zinc and zinc sulfate in diets for gestating and lactating sows
Authors: Holen Julia P , Johnston Lee J , Urriola Pedro E , Garrett Jack E , Shurson Gerald C
Published: March 2020

We hypothesized that the digestibility of a zinc polysaccharide complex is greater than zinc sulfate when sows consume high fiber diets containing corn dried distillers grains with solubles (DDGS). Gilts and sows (n = 32) were blocked according to parity and assigned randomly to one of four dietary treatments (n = 8 sows per treatments). Dietary treatments consisted of: 1) Control (ConZnSO4)—corn–soybean meal-based diet + 100 ppm supplemental Zn from ZnSO4; 2) Control PSZn (ConPSZn)—corn–soybean meal-based diet + 100 ppm supplemental Zn from Zn polysaccharide complex; 3) DDGS/ZnSO4—corn–soybean meal–40% DDGS gestation diet and a 30% DDGS lactation diet, with each containing 100 ppm supplemental Zn from ZnSO4; 4) DDGS/PSZn—corn–soybean meal–40% DDGS gestation diet and a 30% DDGS lactation diet, with each containing 100 ppm supplemental Zn from Zn polysaccharide complex. A fifth dietary treatment was imposed using a subset of sows (n = 20) to determine basal Zn losses in gestating and lactating sows fed corn–soybean meal-based diets containing no supplemental Zn. Nutrient balance experiments were conducted in both gestation and lactation to evaluate the digestibility of Zn sources of the four dietary treatments and to determine basal Zn losses when no supplemental Zn was provided. The statistical model included fixed effects of diet, Zn source, and their interaction, and random effects of parity. Estimated endogenous losses of Zn were used to adjust apparent total tract digestibility (ATTD) to true total tract digestibility (TTTD) of Zn in the four dietary treatment balance periods. There were no differences in Zn concentrations of urine, plasma, colostrum, or milk samples among treatments at any time of the experiment (P > 0.05). Gestating sows fed DDGS/PSZn had improved (P < 0.05) ATTD, TTTD, and overall retention of Zn compared with both Control treatments, with the DDGS/ZnSO4 treatment responses being intermediate. Lactating sows consuming diets without DDGS and supplemented with Zn polysaccharide complex had the greatest (P < 0.05) ATTD, TTTD, and retention of Zn, which were opposite to responses observed in gestation. Furthermore, ATTD, TTTD, and Zn retention for lactating sows consuming DDGS/PSZn were less (P < 0.05) than all other treatments. Overall, zinc digestibility of ZnSO4 and PSZn appears to be differentially influenced by the stage of the reproductive cycle and presence of dietary fiber from DDGS.
Increasing the ratio of SID lysine to metabolizable energy improves pig performance during a viral challenge
Authors: Jasper Jessica E , Mendoza Omarh F , Shull Caleb M , Schweer Wesley P , Schwartz Kent J , Gabler Nicholas K
Published: March 2020

Porcine reproductive and respiratory syndrome virus (PRRSV) compromises pig performance. However, increasing standardized ileal digestible Lys per Mcal metabolizable energy (SID Lys:ME) above requirement has been shown to mitigate reduced performance seen during a porcine reproductive and respiratory syndrome (PRRS) virus challenge. The objective of this study was to evaluate the effects of increasing the dietary SID Lys:ME from 100% National Research Council (NRC) requirement to 120% of the requirement in vaccinated (vac+; modified live vaccine Ingelvac PRRS) and non-vaccinated (vac−; no PRRS vaccine) grower pigs subjected to a PRRSV challenge. In addition, the dietary formulation approach to achieve the 120% ratio by increasing Lys relative to energy (HL) or diluting energy in relation to Lys (LE) was evaluated. This allowed us to test the hypothesis that pigs undergoing a health challenge would have the ability to eat to their energy needs. Within vaccine status, 195 mixed-sex pigs, vac+ (35.2 ± 0.60 kg body weight [BW]) and vac− (35.2 ± 0.65 kg BW) were randomly allotted to one of three dietary treatments (2.67, 3.23, or 3.22 g SID Lys:ME) for a 42-d PRRS virus challenge study representing 100%, 120%, and 120% of NRC requirement, respectively. Pigs were randomly allotted across two barns, each containing 24 pens with 7 to 10 pigs per pen (8 pens per diet per vaccine status). On day post-inoculation 0, both barns were inoculated with PRRSV and started on experimental diets. Within vaccine status, weekly and overall challenge period pig performance were assessed. In both vac+ (P < 0.05) and vac− (P < 0.05) pigs, the HL and LE diets increased end BW and overall average daily gain (ADG) ADG compared with pigs fed the control diet (P < 0.05). Overall, average daily feed intake (ADFI) during the challenge period was greater (P < 0.05) for pigs fed the LE diet compared with pigs fed control and HL treatments, regardless of vaccine status (20% and 17% higher ADFI than the control in vac+ and vac− pigs, respectively). The HL vac+ pigs had the greatest gain to feed (G:F) compared with the control and LE pigs (0.438 vs. 0.394 and 0.391 kg/kg, respectively; P < 0.01). Feed efficiency was not impacted (P > 0.10) by treatment in the vac− pigs. In summary, PRRSV-challenged grower pigs consumed feed to meet their energy needs as indicated by the increase in ADFI when energy was diluted in the (LE) diet, compared with control pigs. In both PRRS vac+ and vac− pigs subsequently challenged with PRRSV, regardless of formulation approach, fed 120% SID Lys:ME diets resulted in enhanced overall growth performance.
Landscape genetics of wolverines (Gulo gulo): scale-dependent effects of bioclimatic, topographic, and anthropogenic variables
Authors: Balkenhol Niko , Schwartz Michael K , Inman Robert M , Copeland Jeffrey P , Squires John S , Anderson Neil J , Waits Lisette P
Published: March 2020

Climate change can have particularly severe consequences for high-elevation species that are well-adapted to long-lasting snow conditions within their habitats. One such species is the wolverine, Gulo gulo, with several studies showing a strong, year-round association of the species with the area defined by persistent spring snow cover. This bioclimatic niche also predicts successful dispersal paths for wolverines in the contiguous United States, where the species shows low levels of genetic exchange and low effective population size. Here, we assess the influence of additional climatic, vegetative, topographic, and anthropogenic, variables on wolverine genetic structure in this region using a multivariate, multiscale, landscape genetic approach. This approach allows us to detect landscape-genetic relationships both due to typical, small-scale genetic exchange within habitat, as well as exceptional, long-distance dispersal among habitats. Results suggest that a combination of snow depth, terrain ruggedness, and housing density, best predict gene flow in wolverines, and that the relative importance of variables is scale-dependent. Environmental variables (i.e., isolation-by-resistance, IBR) were responsible for 79% of the explained variation at small scales (i.e., up to ~230 km), and 65% at broad scales (i.e., beyond ~420 km). In contrast, a null model based on only space (i.e., isolation-by-distance, IBD) accounted only for 17% and 11% of the variation at small and broad scales, respectively. Snow depth was the most important variable for predicting genetic structures overall, and at small scales, where it contributed 43% to the variance explained. At broad spatial scales, housing density and terrain ruggedness were most important with contributions to explained variation of 55% and 25%, respectively. While the small-scale analysis most likely captures gene flow within typical wolverine habitat complexes, the broad-scale analysis reflects long-distance dispersal across areas not typically inhabited by wolverines. These findings help to refine our understanding of the processes shaping wolverine genetic structure, which is important for maintaining and improving functional connectivity among remaining wolverine populations.
Bayes-Raking: Bayesian Finite Population Inference with Known Margins
Authors: Si Yajuan , Zhou Peigen
Published: March 2020

Raking is widely used for categorical data modeling and calibration in survey practice but faced with methodological and computational challenges. We develop a Bayesian paradigm for raking by incorporating the marginal constraints as a prior distribution via two main strategies: (1) constructing solution subspaces via basis functions or the projection matrix and (2) modeling soft constraints. The proposed Bayes-raking estimation integrates the models for the margins, the sample selection and response mechanism, and the outcome as a systematic framework to propagate all sources of uncertainty. Computation is done via Stan, and codes are ready for public use. Simulation studies show that Bayes-raking can perform as well as raking with large samples and outperform in terms of validity and efficiency gains, especially with a sparse contingency table or dependent raking factors. We apply the new method to the longitudinal study of well-being study and demonstrate that model-based approaches significantly improve inferential reliability and substantive findings as a unified survey inference framework.
Mental Health Service Utilization and Perceived Barriers to Receiving Care in Deployed Soldiers
Authors: Nugent Katie L , Riviere Lyndon A , Sipos Maurice L , Wilk Joshua E
Published: March 2020

Introduction

Scant research has examined mental health treatment utilization and barriers to care in deployed U.S. soldiers. This study aims to assess mental health treatment utilization in deployed soldiers, including providers used and barriers to care.

Materials and Methods

U.S. Army soldiers (n = 2,412) in a combat environment were surveyed on psychiatric symptoms, mental health help received, sources of care, and perceived barriers to care by Mental Health Advisory teams from 2009 to 2013.

Results

Of the 25% of soldiers at mental health risk, 37% received mental health help, with 18% receiving help from a provider. Nonprovider sources of care were utilized significantly more frequently than providers. Soldiers at mental health risk reported significantly greater anticipated career-related stigma, organizational barriers to care, self-reliance views, and negative attitudes toward care, yet these constructs did not differ between who did or did not receive help. Soldiers who received help from providers exclusively reported significantly more anticipated career-related stigma and fewer organizational barriers to care than those that received no help. Soldiers who spent no time living outside the forward operating base and soldiers with six or more types of combat exposures were more likely to receive help.

Conclusions

Prevalence of common psychopathology and receipt of care in a combat environment was similar to previous reports from postdeployment settings. Nonprovider sources of care were more frequently utilized as compared to an in-Garrison report. Findings suggest important differences exist in sources of help and barriers to care in deployed vs. postdeployment environments. The hypothesized barriers to care did not preclude receiving any help, however, less than one-half of soldiers at mental health risk received help. Thus, future research should identify factors that have the greatest influence on help seeking behavior in both deployed and Garrison settings.
Searching for dark matter signals from local dwarf spheroidal galaxies at low radio frequencies in the GLEAM survey
Authors: Cook R H W , Seymour N , Spekkens K , Hurley-Walker N , Hancock P J , Bell M E , Callingham J R , For B-Q , Franzen T M O , Gaensler B M , Hindson L , Johnston-Hollitt M , Kapińska A D , Morgan J , Offringa A R , Procopio P , Staveley-Smith L , Wayth R B , Wu C , Zheng Q
Published: March 2020

The search for emission from weakly interacting massive particle (WIMP) dark matter annihilation and decay has become a multipronged area of research not only targeting a diverse selection of astrophysical objects, but also taking advantage of the entire electromagnetic spectrum. The decay of WIMP particles into standard model particles has been suggested as a possible channel for synchrotron emission to be detected at low radio frequencies. Here, we present the stacking analysis of a sample of 33 dwarf spheroidal (dSph) galaxies with low-frequency (72–231 MHz) radio images from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. We produce radial surface brightness profiles of images centred upon each dSph galaxy with background radio sources masked. We remove 10 fields from the stacking due to contamination from either poorly subtracted, bright radio sources or strong background gradients across the field. The remaining 23 dSph galaxies are stacked in an attempt to obtain a statistical detection of any WIMP-induced synchrotron emission in these systems. We find that the stacked radial brightness profile does not exhibit a statistically significant detection above the 95 per cent confidence level of ∼1.5 mJy beam−1. This novel technique shows the potential of using low-frequency radio images to constrain fundamental properties of particle dark matter.
Abundance analyses of Li-enriched and normal giants in the GALAH survey
Authors: Deepak  , Lambert David L , Reddy Bacham E
Published: March 2020

Compositions of lithium-enriched and normal giants among the GALAH survey are compared. Except for Li, the only detectable abundance difference between lithium-enriched and normal giants among the investigated elements from carbon to europium occurs for carbon. Among Li-rich giants with A(Li) = 1.8 to 3.1, the C deficiency is very similar to that reported for the normal giants (with A(Li) < 1.8) where the slight C deficiency arises from the first dredge-up. Carbon is slightly under abundant relative to normal giants among the super Li-rich giants where the Li abundance exceeds A(Li) = 3.2. The C abundance as well as the 12C/13C ratios from the literature suggest that addition of Li to create a Li-rich giant may occur independently of the abundance changes wrought by the first dredge-up. Creation of a super Li-rich giant, however, appears to occur with additional CN-cycle conversion of C to N. The probability of becoming a Li-rich giant is approximately independent of a star’s mass, although the majority of the Li-rich giants are found to be low mass (M ≤ 2 M⊙). The frequency of occurrence of Li-enriched giants among normal giants is about one percent and slightly dependent on metallicity ([Fe/H]). Li-enriched and normal giants are found to have similar projected rotational velocity which suggest that Li-enrichment in giants is not linked to scenarios such as mergers and tidal interaction between binary stars.
Hard X-ray selected giant radio galaxies – II. Morphological evidence of restarted radio activity
Authors: Bruni G , Panessa F , Bassani L , Dallacasa D , Venturi T , Saripalli L , Brienza M , Hernández-García L , Chiaraluce E , Ursini F , Bazzano A , Malizia A , Ubertini P
Published: March 2020

About 6 per cent of radio galaxies (RGs) can reach linear sizes larger than 0.7 Mpc, and are then classified as giant radio galaxies (GRGs). The conditions that make possible the formation of such big structures are still not clear – either core accretion properties or environmental factors. Recent studies have shown that GRGs can be up to four times more abundant in hard X-ray selected (i.e. from INTEGRAL/IBIS and Swift/BAT at >20 keV) RG samples. Moreover, a high fraction of young radio sources found in their cores suggest a recently restarted activity, as suggested from the discrepancy between the measured jet and lobes power, with respect to the one expected from core X-ray luminosity. Here, we present a radio morphological study of a sample of 15 hard X-ray selected GRGs, discussing low-frequency images from our GMRT campaign complemented with others from the literature: among them, 7/15 show evidence of restarted radio activity either in the form of double–double/X-shaped morphology, or as a cocoon emission embedding more recent jets. This, together with the objects from this sample already found hosting a young radio source in their core, suggests that at least 13 over 15 of these hard X-ray selected GRGs show features that are consistent with the possibility of restarted radio activity.
Confirmed short periodic variability of subparsec supermassive binary black hole candidate Mrk 231
Authors: Kovačević Andjelka B , Yi Tignfeng , Dai Xinyu , Yang Xing , Čvorović-Hajdinjak Iva , Popović Luka Č
Published: March 2020

Here we confirm the short periodic variability of a subparsec supermassive binary black hole (SMBBH) candidate Mrk 231 in the extended optical photometric data set collected by the Catalina Real-Time Transient Survey (CRTS) and All-Sky Automated Survey for Supernovae (ASAS-SN). Using the Lomb–Scargle periodogram and 2DHybrid method, we detected the significant periodicity of ∼1.1 yr beyond a damped random walk model in the CRTS+ASAS-SN optical data set. Mrk 231 has been previously proposed as an SMBBH candidate with a highly unequal mass ratio (q ∼ 0.03), very tight mutual separation of ∼590 au, and an orbital period of ∼1.2 yr. Hence, our result further supports, even though not prove, the intriguing hypothesis that SMBBHs with low mass ratios may be more common than close-equal mass SMBBHs. This result, however, was obtained from the contribution of the CRTS data with limited sampling cadence and photometric accuracy, and further monitoring of Mrk 231 is crucial to confirm the periodicity.
Safety and Outcomes of Linezolid Use for Nocardiosis
Authors: Davidson Natalie , Grigg Matthew J , Mcguinness Sarah L , Baird Robert J , Anstey Nicholas M
Published: March 2020

Background

Tropical Australia has a high incidence of nocardiosis, with high rates of intrinsic antimicrobial resistance. Linezolid, the only antimicrobial to which all local Nocardia species are susceptible, has been recommended in empirical combination treatment regimens for moderate–severe Nocardia infections at Royal Darwin Hospital (RDH) since 2014. We report the safety and efficacy of linezolid use for nocardiosis in this setting.

Methods

We identified cases through a retrospective review of all RDH Nocardia isolates from December 2014 to August 2018 and included 5 linezolid-treated cases from a previous cohort. Laboratory, demographic, and clinical data were included in the primary analysis of safety and treatment outcomes.

Results

Between 2014 and 2018, Nocardia was isolated from 35 individuals; 28 (80%) had clinically significant infection and 23 (82%) received treatment. All isolates were linezolid-susceptible. Safety and efficacy were assessed for 20 patients receiving linezolid-containing regimens and 8 receiving nonlinezolid regimens. Median linezolid induction therapy duration was 28 days. Common adverse effects in those receiving linezolid were thrombocytopenia (45%) and anemia (40%). Adverse events prompted discontinuation of trimethoprim-sulfamethoxazole more often than linezolid (40% vs 20%). Linezolid therapeutic drug monitoring was used in 1 patient, with successful dose reduction and outcome. There was no difference in 30-day survival between those treated with linezolid (90%) vs no linezolid (87%). One Nocardia-attributed death occurred during linezolid therapy.

Conclusions

Linezolid is safe and efficacious in empirical treatment for moderate to severe nocardiosis in a monitored hospital setting, with 100% drug susceptibility and no difference in adverse events or outcomes compared with nonlinezolid regimens.
Per-Contact Infectivity of Hepatitis C Virus Acquisition in Association With Receptive Needle Sharing Exposures in a Prospective Cohort of Young Adult People who Inject Drugs in San Francisco, California
Authors: Leyva Yuridia , Page Kimberly , Shiboski Stephen , Hahn Judith A , Evans Jennifer , Erhardt Erik
Published: March 2020

Background

Sharing needles and ancillary injecting equipment is a primary risk exposure for hepatitis C virus (HCV) infection among people who inject drugs (PWID); however, infectivity of these exposures is not well quantified. We aimed to estimate per-event HCV infectivity associated with receptive needle sharing (RNS) among susceptible PWID.

Methods

Participants in a prospective cohort study of young adult PWID who were anti-HCV and HCV RNA negative at baseline and attended at least 2 follow-up study visits between 2003 and 2014 were eligible. Data were selected from the first HCV-negative through the first HCV-positive visit (or last HCV-negative among those uninfected). Anti-HCV and HCV-RNA tests were used to determine infection status. A probabilistic exposure model linking observed HCV infection outcomes to self-reported exposure events was applied to estimate infectivity.

Results

Among 344 participants, a maximum likelihood estimate considering RNS yielded a pooled population per RNS event HCV probability of 0.25% (95% confidence interval [CI], 0.10%–0.43%), and 1.12% (95% CI, 0.48%–2.35%) among those who acquired any HCV infection (primary or reinfection).

Conclusions

HCV is highly infectious in association with RNS, a primary injection-related risk exposure. Our infectivity estimate among participants who acquired any HCV infection is 1.7 times higher than that estimated for HIV infection in PWID and 2.24 times higher than that estimated among health care workers exposed through needle sticks. The strengths of this study include the assessment of receptive needle sharing events, the prospective design, and relatively short recall and testing periods. These results can inform transmission models and research to prevent HCV infection.
Microbiology and Risk Factors for Hospital-Associated Bloodstream Infections Among Pediatric Hematopoietic Stem Cell Transplant Recipients
Authors: Akinboyo Ibukunoluwa C , Young Rebecca R , Spees Lisa P , Heston Sarah M , Smith Michael J , Chang Yeh-Chung , McGill Lauren E , Martin Paul L , Jenkins Kirsten , Lugo Debra J , Hazen Kevin C , Seed Patrick C , Kelly Matthew S
Published: March 2020

Background

Children undergoing hematopoietic stem cell transplantation (HSCT) are at high risk for hospital-associated bloodstream infections (HA-BSIs). This study aimed to describe the incidence, microbiology, and risk factors for HA-BSI in pediatric HSCT recipients.

Methods

We performed a single-center retrospective cohort study of children and adolescents (<18 years of age) who underwent HSCT over a 20-year period (1997–2016). We determined the incidence and case fatality rate of HA-BSI by causative organism. We used multivariable Poisson regression to identify risk factors for HA-BSI.

Results

Of 1294 patients, the majority (86%) received an allogeneic HSCT, most commonly with umbilical cord blood (63%). During the initial HSCT hospitalization, 334 HA-BSIs occurred among 261 (20%) patients. These were classified as gram-positive bacterial (46%), gram-negative bacterial (24%), fungal (12%), mycobacterial (<1%), or polymicrobial (19%). During the study period, there was a decline in the cumulative incidence of HA-BSI (P = .021) and, specifically, fungal HA-BSIs (P = .002). In multivariable analyses, older age (incidence rate ratio [IRR], 1.03; 95% confidence interval [CI], 1.01–1.06), umbilical cord blood donor source (vs bone marrow; IRR, 1.69; 95% CI, 1.19–2.40), and nonmyeloablative conditioning (vs myeloablative; IRR, 1.85; 95% CI, 1.21–2.82) were associated with a higher risk of HA-BSIs. The case fatality rate was higher for fungal HA-BSI than other HA-BSI categories (21% vs 6%; P = .002).

Conclusions

Over the past 2 decades, the incidence of HA-BSIs has declined among pediatric HSCT recipients at our institution. Older age, umbilical cord blood donor source, and nonmyeloablative conditioning regimens are independent risk factors for HA-BSI among children undergoing HSCT.
Low Sensitivity of Procalcitonin for Bacteremia at an Academic Medical Center: A Cautionary Tale for Antimicrobial Stewardship
Authors: Goodlet Kellie J , Cameron Emily A , Nailor Michael D
Published: March 2020

Background

Procalcitonin testing has been adopted by antimicrobial stewardship programs as a means of reducing inappropriate antibiotic use, including within intensive care units (ICUs). However, concerns regarding procalcitonin’s sensitivity exist. The purpose of this study is to calculate the sensitivity of procalcitonin for bacteremia among hospitalized patients.

Methods

This was a retrospective cohort study of adult patients admitted to an academic medical center between July 1, 2018, and June 30, 2019, with ≥1 positive blood culture within 24 hours of admission and procalcitonin testing within 48 hours. Low procalcitonin was defined as <0.5 µg/L.

Results

A total of 332 patients were included. The sensitivity of procalcitonin for bacteremia was 62% at the sepsis threshold of 0.5 µg/L, 76% at a threshold of 0.25 µg/L, and 92% at a threshold of 0.1 µg/L. Of the 125 patients with low procalcitonin, 14% were initially admitted to the ICU and 9% required the use of vasopressors. In that same group, the top 3 organisms isolated were Staphylococcus aureus (39%), Escherichia coli (17%), and Klebsiella spp. (7%). Compared with those patients with elevated procalcitonin, patients with low procalcitonin were significantly more likely to have >24-hour delayed receipt of antibiotic therapy (3% vs 8%; P = .04), including among patients admitted to the ICU (1% vs 18%; P = .02).

Conclusions

The sensitivity of procalcitonin for bacteremia is unacceptably low for a rule-out test. Antimicrobial stewardship programs should use caution before promoting the withholding of antibiotic therapy for patients with low initial procalcitonin values.
Oxytocin and the stress buffering effect of social company: a genetic study in daily life
Authors: Sicorello Maurizio , Dieckmann Linda , Moser Dirk , Lux Vanessa , Luhmann Maike , Schlotz Wolff , Kumsta Robert
Published: March 2020

Social relationships are a crucial determinant of both mental and physical health. This effect is partly due to social buffering of stress. Animal studies suggest that social buffering is mediated via the oxytocin system, while studies in humans are sparse and limited by the low ecological validity of laboratory settings. In the present study, participants (N = 326) completed smartphone questionnaires four times a day over 4 to 5 days, measuring stressors, negative affect, and social context to assess social buffering. We found that under stress, participants reported a higher need for social company. Further, the impact of prior stressful events on momentary negative affect was attenuated by the perceived pleasantness of current social company. This social buffering effect was moderated by haplotypes of the oxytocin receptor gene, based on two well-described single nucleotide polymorphisms (rs2268498, rs53576). Effects were robust when controlling for gender and age, applying different data quality criteria, and even apparent in genotype-based analyses. Our findings demonstrate that social buffering and its modulation by oxytocin system characteristics have implications for life as lived outside the laboratory.
Evaluating the Performance of Probabilistic Algorithms for Phylogenetic Analysis of Big Morphological Datasets: A Simulation Study
Authors: Vernygora Oksana V , Simões Tiago R , Campbell Erin O
Published: March 2020

Reconstructing the tree of life is an essential task in evolutionary biology. It demands accurate phylogenetic inference for both extant and extinct organisms, the latter being almost entirely dependent on morphological data. While parsimony methods have traditionally dominated the field of morphological phylogenetics, a rapidly growing number of studies are now employing probabilistic methods (maximum likelihood and Bayesian inference). The present-day toolkit of probabilistic methods offers varied software with distinct algorithms and assumptions for reaching global optimality. However, benchmark performance assessments of different software packages for the analyses of morphological data, particularly in the era of big data, are still lacking. Here, we test the performance of four major probabilistic software under variable taxonomic sampling and missing data conditions: the Bayesian inference-based programs MrBayes and RevBayes, and the maximum likelihood-based IQ-TREE and RAxML. We evaluated software performance by calculating the distance between inferred and true trees using a variety of metrics, including Robinson-Foulds (RF), Matching Splits (MS), and Kuhner-Felsenstein (KF) distances. Our results show that increased taxonomic sampling improves accuracy, precision, and resolution of reconstructed topologies across all tested probabilistic software applications and all levels of missing data. Under the RF metric, Bayesian inference applications were the most consistent, accurate, and robust to variation in taxonomic sampling in all tested conditions, especially at high levels of missing data, with little difference in performance between the two tested programs. The MS metric favored more resolved topologies that were generally produced by IQ-TREE. Adding more taxa dramatically reduced performance disparities between programs. Importantly, our results suggest that the RF metric penalizes incorrectly resolved nodes (false positives) more severely than the MS metric, which instead tends to penalize polytomies. If false positives are to be avoided in systematics, Bayesian inference should be preferred over maximum likelihood for the analysis of morphological data.
Here comes the flood! Stress effects of continuous and interval waterlogging periods during the growing season on Scots pine saplings
Authors: Domisch Timo , Qian Ji , Sondej Izabela , Martz Françoise , Lehto Tarja , Piirainen Sirpa , Finér Leena , Silvennoinen Raimo , Repo Tapani
Published: March 2020

Future climate scenarios for the boreal zone project increasing temperatures and precipitation, as well as extreme weather events such as heavy rain during the growing season. This can result in more frequent short-term waterlogging (WL) leading to unfavorable conditions for tree roots. In addition, it is decisive whether short-term WL periods during the growing season occur continuously or periodically. We assessed the effects of short-termed WL on 4-year-old Scots pine (Pinus sylvestris L.) saplings after shoot elongation started. Waterlogging (WL) lasted either continuously for 2.5 weeks (ContWL) or noncontinuously for 5 weeks, consisting of three repeated 1-week-interval WL periods (IntWL). Both treatments resulted in the same duration of soil anoxia. We studied soil gases, root and shoot growth and physiology, and root survival probability and longevity during the experiment. In the final harvest, we determined shoot and root biomass and hydraulic conductance and electrical impedance spectra of the root systems. Soil CO2 and CH4 concentrations increased immediately after WL onset and O2 decreased until anoxia. Waterlogging decreased fine root survival probability, but there was no difference between WL treatments. Shoot growth suffered more from ContWL and root growth more from IntWL. Needle concentrations of pinitol increased in the WL saplings, indicating stress. No WL effects were observed in photosynthesis and chlorophyll fluorescence. Increased starch concentration in needles by WL may be due to damaged roots and thus a missing belowground sink. Electrical impedance indicated suffering of WL saplings, although root hydraulic conductance did not differ between the treatments. Oxidative stress of short-term and interval WL can have long-lasting effects on shoot and root growth and the physiology of Scots pine. We conclude that even short-term WL during the growing season is a stress factor, which will probably increase in the future and can affect carbon allocation and dynamics in boreal forests.
The Clinical Utility of Additional Axillary and Velpeau Radiographs in the Evaluation of Suspected Shoulder Trauma
Authors: Cruz Sebastian A. , Castillo Hector , Chintapalli Ravi Theja V. , Adams Olufemi E. , Morgan Vince K. , Koh Jason L. , Lee Michael J. , Shi Lewis L.
Published: March 2020

Objectives:

To investigate the clinical utility of additional axillary or Velpeau views in evaluating potential shoulder trauma after a standard radiograph series of anteroposterior, Grashey, and/or trans-scapular views.

Design:

Retrospective study.

Setting:

Level I academic medical center.

Patients:

All patients in a 10-year span who received an initial shoulder radiograph series followed by additional axillary/Velpeau views within 24 hours.

Main Outcome Measurements:

The clinical utility of the additional axillary/Velpeau views, including the final diagnosis and treatment plan, as ascertained through examination of radiology reports, progress notes, and radiograph images.

Results:

A total of 271 cases were reviewed, with 35 patients being excluded from the final cohort because they received post-treatment radiographs to confirm a successful therapeutic outcome. The additional axillary/Velpeau views did not affect clinical decision making in 230 (97.5%) of the remaining 236 cases. All 6 patients whose care benefitted from the additional views carried the diagnosis of shoulder instability, accounting for 40% of this diagnostic group. The additional views confirmed an equivocal finding in 5 of these 6 cases and changed the diagnosis (demonstrating a posterior dislocation that was not evident on initial radiographs) and treatment plan (leading to a closed glenohumeral reduction procedure) in the other case.

Conclusions:

Additional axillary/Velpeau views of suspected shoulder trauma rarely led to a change in the final treatment plan, except in patients in which a definitive diagnosis of stability or instability could not be made based on initial radiographs. A cost/benefit analysis is required to weigh the cost of additional radiographs with the benefit of capturing infrequent yet serious dislocations (usually posterior).

Level of Evidence:

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Gene therapy beyond luxturna: a new horizon of the treatment for inherited retinal disease
Authors: Prado Dominic A. , Acosta-Acero Marcy , Maldonado Ramiro S.
Published: March 2020

Purpose of review

Gene therapy offers, for the first time, the possibility to cure diseases such as retinitis pigmentosa. The positive outcomes that led to the U.S. Food and Drug Administration (FDA) approval of Luxturna to treat Leber congenital amaurosis caused by RPE65 mutations created an optimistic atmosphere in the research, clinical and patient community. Despite this first success, we must understand that this is not a ‘one treatment for all’. This review aims to explain the basic concepts of gene therapy and how they translate in different approaches that are utilized in ongoing clinical trials here reviewed.

Recent findings

In 2017, the FDA approved the first gene therapy treatment. In parallel, other approaches have gained attention. Different delivery methods (adeno-associated virus, lentivirus), injection sites (subretinal, intravitreal, suprachoroidal) and methodologies (gene replacement, silencing, editing) are currently being tested.

Gene therapy is an evolving field in medicine and ophthalmology. Its success and application depends on several factors that are specific to the disease to treat. For now, we know it's a relatively safe approach and we look forward to the continued advancements of current ongoing clinical trials.
Clinical outcomes after topography-guided LASIK: comparing results based on a new topography analysis algorithm with those based on manifest refraction
Authors: Lobanoff Mark , Stonecipher Karl , Tooma Tom , Wexler Stephen , Potvin Richard
Published: March 2020

Purpose:

To compare short-term refractive and visual acuity outcomes after topography-guided laser in situ keratomileusis (LASIK) planned with a new topography analysis system to those based on the manifest refraction.

Setting:

Four clinical sites in the United States.

Design:

Double-arm, nonmasked, nonrandomized retrospective chart review.

Methods:

This was a retrospective study of postoperative refraction and visual acuity at least 2 months after uneventful LASIK using the Contoura Vision algorithm on the WaveLight Topolyzer VARIO laser. One arm comprised eyes treated using the manifest refraction (manifest), while the other included eyes treated with an ablation profile determined by the Phorcides Analytic Engine (analytic).

Results:

Clinical results from a matched group of 317 manifest eyes and 323 analytic eyes were available for analysis. Residual refractive results, both sphere and cylinder, were similar between groups. However, significantly more eyes had 20/16 or better (−0.1 logarithm of the minimum angle of resolution) uncorrected distance visual acuity (UDVA) (62.5% analytic, 41.3% manifest) and corrected distance visual acuity (CDVA) (77.1% analytic, 51.4% manifest) in the analytic group. All eyes but 1 had a CDVA of 20/20 or better postoperatively. The number of patients with a UDVA better than their preoperative CDVA was significantly higher in the analytic group (36.5%) relative to the manifest group (23.0%). No eye in either group lost more than 1 line of CDVA; significantly more eyes in the analytic group (42.7%) gained 1 or more lines of CDVA relative to the manifest group (30.3%).

Conclusions:

Using the Phorcides Analytic Engine for topography-guided surgery planning increased the likelihood of 20/16 UDVA and CDVA relative to using the manifest refraction.
Skin Cancer
Authors: Davis Kyleen E.
Published: March 2020

Basal cell carcinoma (BCC) is the most common form of skin cancer in the United States, with an estimated 4.3 million cases diagnosed each year. The major risk for BCC is primarily related to sun exposure; however, multiple modifiable and nonmodifiable risk factors contribute to the development of this condition. Although it rarely metastasizes, BCC can cause significant morbidity through local tissue destruction and infiltration into vital underlying organs. There are multiple treatment options for BCC, but Mohs micrographic surgery is considered to be the gold standard of therapy. For individuals with unresectable or metastatic BCC, new and emerging therapies involving inhibition of the Hedgehog signaling pathway have shown promising results. This article discusses the most current literature for dermatology nurses on the epidemiology, assessment, and treatment of BCC with the focus on early detection and management to lower morbidity and offer better patient outcomes.