bluuebunny/crossref_metadata_2025 huggingface dataset:
Utilization of Predictive Modeling to Determine Episode of Care Costs and to Accurately Identify Catastrophic Cost Nonwarranty Outlier Patients in Adult Spinal Deformity Surgery
Authors: Ames Christopher P. , Smith Justin S. , Gum Jeffrey L. , Kelly Michael , Vila-Casademunt Alba , Burton Douglas C. , Hostin Richard , Yeramaneni Samrat , Lafage Virginie , Schwab Frank J. , Shaffrey Christopher I. , Bess Shay , Pellisé Ferran , Serra-Burriel Miquel
Published: September 2019

Study Design.

Retrospective review of prospectively-collected, multicenter adult spinal deformity (ASD) database.

Objective.

The aim of this study was to evaluate the rate of patients who accrue catastrophic cost (CC) with ASD surgery utilizing direct, actual costs, and determine the feasibility of predicting these outliers.

Summary of Background Data.

Cost outliers or surgeries resulting in CC are a major concern for ASD surgery as some question the sustainability of these surgical treatments.

Methods.

Generalized linear regression models were used to explain the determinants of direct costs. Regression tree and random forest models were used to predict which patients would have CC (>$100,000).

Results.

A total of 210 ASD patients were included (mean age of 59.3 years, 83% women). The mean index episode of care direct cost was $70,766 (SD = $24,422). By 90 days and 2 years following surgery, mean direct costs increased to $74,073 and $77,765, respectively. Within 90 days of the index surgery, 11 (5.2%) patients underwent 13 revisions procedures, and by 2 years, 26 (12.4%) patients had undergone 36 revision procedures. The CC threshold at the index surgery and 90-day and 2-year follow-up time points was exceeded by 11.9%, 14.8%, and 19.1% of patients, respectively. Top predictors of cost included number of levels fused, surgeon, surgical approach, interbody fusion (IBF), and length of hospital stay (LOS). At 90 days and 2 years, a total of 80.6% and 64.0% of variance in direct cost, respectively, was explained in the generalized linear regression models. Predictors of CC were number of fused levels, surgical approach, surgeon, IBF, and LOS.

Conclusion.

The present study demonstrates that direct cost in ASD surgery can be accurately predicted. Collectively, these findings may not only prove useful for bundled care initiatives, but also may provide insight into means to reduce and better predict cost of ASD surgery outside of bundled payment plans.

Level of Evidence: 3
A Career in Nursing
Authors: Miller Christine L.
Published: September 2019

Is nursing a choice, a vocation, a calling? What is the significance of these terms? Caring remains the underlying foundation of nursing practice that can transform the choice of nursing as a career into a higher calling. Nurses often find life satisfaction in fulfilling God's call to care.
Engaging Faith for Spiritual Fitness
Authors: Busby Steven
Published: September 2019

The experience of going from a student nurse to a working registered nurse can be quite an adjustment. Once the newness of the first job wears off, graduate nurses may be prone to unexpected burnout and compassion fatigue. The purpose of this article is to help student nurses recognize ways to engage their faith to lay the foundation for spiritual fitness and to plan for the spiritual care they will need to have a long, impactful, and satisfying career.
Distinguishing and Addressing Gender Minority Stress and Borderline Personality Symptoms
Authors: Goldhammer Hilary , Crall Cary , Keuroghlian Alex S.
Published: September 2019

As transgender and gender-diverse people are gaining increased visibility in clinical settings, clinicians are requesting better guidance on providing affirming care to improve the mental health and well-being of these patients. In particular, more direction is needed on whether, when, and how to diagnose and treat borderline personality disorder among gender minorities, partially in response to beliefs among some mental health clinicians that a gender minority identity may be a manifestation of identity diffusion. In this Perspectives article, we argue that gender minority identity, even when fluid, is rarely a sign of identity diffusion. By taking a careful history of a patient’s gender identity development, the clinician can clarify and gain more conviction regarding the presence of a patient’s gender minority identity. Moreover, multiple stigma-related stressors experienced by gender minorities may produce symptoms and behaviors that can mimic or be consistent with certain diagnostic criteria for borderline personality disorder. We therefore conclude with recommendations for adopting a gender-affirming framework to treat borderline personality symptoms when present among gender minority patients, with implications for future research and practice.
Endocarditis and bacterial brain abscess in a young woman with a single atrium, patent ductus arteriosus, and Eisenmenger syndrome
Authors: Wang Wuwan , Feng Panpan , Wang Lu , Dong Qian , Huang Wei
Published: September 2019

Rationale:

A single atrium is a rare congenital heart disease (CHD) involving zero atrial septal traces and preserved intact ventricular septum and atrioventricular valves, requiring careful surgical intervention. However, developing to Eisenmenger syndrome (ES) makes the surgery complicated. Based on bidirectional cardiac shunting, vegetation easily develops in case of bacterial infection.

Patient concern and diagnoses:

We reported a 35-year-old woman with a single atrium, patent ductus arteriosus, pulmonary hypertension, and ES who developed infective endocarditis on her left ventricular outflow tract and complicated cerebral abscess and who underwent challenged medical treatment.

Intervention:

Infection was successfully controlled after 4-time change in antibiotics over 4 months. However, surgery is complicated for her.

Outcomes:

The patient presented a relatively good outcome during follow-up for >6 months.

Lessons:

This case report suggests that patients with complex CHD should accept surgery therapy earlier before developing ES. It is imperative to avoid invasive interventions to prevent infectious endocarditis.
Only one-third of hepatocellular carcinoma cases are diagnosed via screening or surveillance: a systematic review and meta-analysis
Authors: Zhao Changqing , Xing Feng , Yeo Yee Hui , Jin Michelle , Le Richard , Le Michael , Jin Mingjuan , Henry Linda , Cheung Ramsey , Nguyen Mindie H.
Published: September 2019

Background/objects

Early hepatocellular carcinoma diagnosis is associated with better long-term survival. Studies of at-risk patients who are monitored in routine practice have reported an overall adherence rate to hepatocellular carcinoma screening/surveillance of approximately 60% and suboptimal diagnostic efficacy of the current screening/surveillance tools. However, it is unclear how many hepatocellular carcinoma patients were actually diagnosed via screening/surveillance given these obstacles. Therefore, via a systematic review of PubMed and Scopus databases from 2000 to 2019, we aimed to identify the proportion of patients with hepatocellular carcinoma diagnosed via screening/surveillance in routine practice.

Methods

We included original research articles of studies of patients already diagnosed with hepatocellular carcinoma that reported the proportion of hepatocellular carcinoma diagnosed via screening/surveillance.

Results

The study included 60 studies and 50 554 hepatocellular carcinoma cases. The pooled proportion of hepatocellular carcinoma diagnosed by screening/surveillance was 37% (95% confidence interval: 31%–44%) and differed by geographic region (North America/Asia/Europe/Oceania/Africa/South America, 31%/42%/41%/30%/29%/47%, P = 0.017, respectively) and by surveillance interval (<12 months 39% vs. 12 months 19%, P < 0.01) but not by disease etiology, cirrhosis status, clinical setting, practice setting, hepatocellular carcinoma diagnosis period, or surveillance method.

Conclusion

Globally, hepatocellular carcinoma was diagnosed via screening/surveillance in less than half of the patients (37%) regardless of healthcare setting or liver disease etiology and without improvement over time despite several recent guideline updates. Research is needed to understand the barriers to screening/surveillance to include medical as well as social and cultural influences.
Transforming the Workforce for Primary Palliative Care Through a System-Wide Educational Initiative
Authors: Duty Susan M. , Loftus Jocelyn
Published: September 2019

Palliative care (PC) is a national and global priority, yet there is insufficient knowledge regarding PC among generalist clinicians. An interdisciplinary educational initiative was implemented to enhance a hospital workforce's PC knowledge and skills. More than 1000 clinicians attended at least 1 of 27 educational offerings. Measurable gains were evident in key outcome measures including PC referrals and advanced directive documentation. Changes reflected a transformation of workforce culture and resulted in 2 national awards for improving PC.
Exploring the Lived Experiences of Staff Nurses Transitioning to the Nurse Manager Role
Authors: Pilat Melissa , Merriam Deborah H.
Published: September 2019

OBJECTIVE

The objective of this study was to discover the experience of nurse managers (NMs) who had transitioned from a staff nurse position

BACKGROUND

Nurses who become NMs may receive little or no training or support during the transition process. This study sought to gain the perspective of NMs who transitioned into the role.

METHODS

A phenomenology method was used to interview 10 NMs regarding their experience of transitioning into the NM role. Meleis Role Transition theory provided the theoretical framework.

RESULTS

Five themes were identified that related to the research questions: expectations, essential knowledge and skills, graduate education prepared, sought support and mentoring from colleagues, and role mastery not possible. Participants experienced role insufficiency due to lack of support and resources.

CONCLUSIONS

Further research is needed to understand nurses' experience after completing an NM developmental program, contributing to role mastery.
Three Years’ Experience
Authors: Harper Mary G. , Maloney Patsy
Published: September 2019

Since its publication in 2016, the third edition of Nursing Professional Development: Scope and Standards of Practice has generated excitement for the specialty. The scope and standards has promoted uniformity of title, stimulated changes in position descriptions, fostered adherence to scope of practice, and served as a unifying framework for system-wide nursing professional development departments. However, continued action is required in the areas of advocacy, research, and engagement with the specialty organization.
Vaccination Capability Inventory of Community, Migrant, and Homeless Health Centers: A Survey Report
Authors: Lewis Joy H. , Whelihan Kate , Roy Debosree , White Earla J. , Morgan Christine , Vora Rupal S. , Boyle Kimberly R. , Luebbering Corey , Bay R. Curtis , Lindley Megan C.
Published: September 2019

Context:

Federally funded Community, Migrant, and Homeless Health Centers provide health services to the most vulnerable communities in the United States. However, little is known about their capabilities and processes for providing vaccinations to adults.

Program:

We conducted the first national survey of health centers assessing their inventory, workflow, capacity for, and barriers to provision of routinely recommended adult vaccines. In addition, we asked health center leaders' perceptions regarding best practices and policy recommendations for adult vaccinations.

Implementation:

A survey was developed on the basis of domains elicited from advisory panels and focus groups and was sent electronically to leaders of 762 health centers throughout the United States and its territories; data were collected and analyzed in 2018.

Evaluation:

A total of 319 survey responses (42%) were obtained. Health centers reported stocking most routinely recommended vaccines for adults; zoster vaccines were not stocked regularly due to supply and storage issues. Respondents most commonly reported adequate reimbursement for vaccination services from private insurance and Medicaid. Most vaccinations were provided during primary care encounters; less than half of health centers reported providing vaccines during specialist visits. Vaccines administered at the health center were most commonly documented in an open field of the electronic health record (96%) or in an immunization information system (72%). Recommendations for best practices related to better documentation of vaccinations and communication with immunization information systems were provided.

Discussion:

Health centers provide most adult vaccines to their patients despite financial and technological barriers to optimal provisioning. Further studies at point of care could help identify mechanisms for system improvements.
Antipruritic Placebo Effects by Conditioning H1-antihistamine
Authors: Meeuwis Stefanie H. , van Middendorp Henriët , Pacheco-Lopez Gustavo , Ninaber Maarten K. , Lavrijsen Adriana P.M. , van der Wee Nic , Veldhuijzen Dieuwke S. , Evers Andrea W.M.
Published: September 2019

Objective

Allergic rhinitis symptoms can be reduced by behaviorally conditioning antihistamine. It is unclear whether these findings extend to histamine-induced itch or work when participants are informed about the conditioning procedure (open-label conditioning). The current study aims to investigate the efficacy of (open-label) antipruritic behavioral conditioning for histamine-induced itch.

Methods

Healthy participants (n= 92; 84% female) were randomized to I) an open-label conditioned, II) closed-label conditioned, III) conditioned-not-evoked control, or IV) nonconditioned control group. A two-phase conditioning paradigm was used. During acquisition, a conditioned stimulus (CS; distinctively tasting beverage) was repeatedly paired with the H1-antihistamine levocetirizine (groups I–III). During evocation, the CS was paired with placebo (I, II), or instead of the CS, water was paired with placebo (III). The nonconditioned control group (IV) received CS with placebo in both phases. Itch after histamine iontophoresis and physiological data (i.e., spirometry, heart rate, skin conductance) were assessed. Combined conditioned and combined control groups were first compared, and analyses were repeated for separate groups.

Results

Marginally lower itch was reported in the combined conditioned compared with the control groups (F(1,88) = 2.10,p= .076, η2partial= 0.02); no differences between separate groups were found. No effects on physiological data were found, except for heart rate, which reduced significantly and consistently for control groups, and less consistently for conditioned groups (group by time interaction:F(7,80) = 2.35,p= .031, η2partial= 0.17).

Conclusion

Limited support was found for the efficacy of antipruritic behavioral conditioning, regardless of whether participants were informed about the conditioning procedure. The application of open-label conditioning in patient populations should be further researched.

Trial Registration:www.trialregister.nl; ID NTR5544.
Application of Postlabeling Delay Time in 3-Dimensional Pseudocontinuous Arterial Spin-Labeled Perfusion Imaging in Normal Children
Authors: Tang Shilong , Liu Xianfan , He Ling , Liu Bo , Qin Bin , Feng Chuan
Published: September 2019

Objective

To explore the application value of postlabeling delay (PLD) in 3D pseudocontinuous arterial spin–labeled (3D-pcASL) perfusion imaging in normal children and to find the optimal PLD values for children at each age group.

Methods

Five groups of children, with 50 patients in each group, who underwent routine magnetic resonance imaging scans with normal results were included. The patients were stratified according to the following ages: younger than 1 month, more than 1 month to 6 months, more than 6 months to 12 months, more than 1 year to 3 years, more than 3 years to 6 years, and more than 6 years to 18 years. All patients received 3D-pcASL perfusion magnetic resonance scanning. The PLD values were set to 1025, 1525, or 2025 milliseconds. In subjective evaluations, the signal-to-noise ratio (SNR) and cerebral blood flow (CBF) of 3D-pcASL perfusion images under different PLD values were compared and analyzed.

Results

For patients in the <1-month group and >1-month to 6-month group, the images were mainly grade A when the PLD value was 1025 milliseconds, which equaled 43 and 46 cases, respectively. The brain CBF values and SNR values were higher than those of the images with PLD values of 1525 and 2025 milliseconds. For patients in the >6-month to 12-month group, >1-year to 3-year group, >3-year to 6-year group, and >6-year to 18-year group, the images were mainly grade A when the PLD value was 1525 milliseconds, which equaled 43, 45, 43, and 46 cases, respectively. The brain CBF values and SNR values were higher than those of the images with PLD values of 1025 and 2025 milliseconds.

Conclusions

The optimal PLD values for 3D-pcASL perfusion imaging are different in children of different ages. The optimal PLD value for infants who are 6 months younger is 1025 milliseconds. The optimal PLD value for children older than 6 months to 18 years is 1525 milliseconds.
Simulation-Based Training in Measurement of Blood Pressure
Authors: Basheer Aneesh , Das Subhasis , Iqbal Nayyar , Kandasamy Ravichandran
Published: September 2019

Introduction

Simulators are used for training competencies including blood pressure (BP) measurement. Whether such training translates to competency in real life is unclear.

Methods

We randomized 145 first-year undergraduate medical students to train on a BP simulator or arms of colleagues. After training, all students were assessed for accuracy (within 4 mm Hg above or below assessor's simultaneous recording) and methodology of BP recordings by an objectively structured clinical examination on real patients.

Results

Overall, 67 (46.2%) and 92 (63.4%) students accurately measured systolic and diastolic BP, respectively. Forty-three (58.1%) of 74 students in the conventional training recorded systolic BP accurately compared with 24 (33.8%) of 71 students in simulator training (P = 0.005). Diastolic BP was accurately recorded by 56 (75.7%) of 74 students in conventional group as against 36 (50.7%) of 71 students trained on simulator (P = 0.002). Median (interquartile range) objectively structured clinical examination score in conventional group was 8 (7–9) compared with 6 (5–7) in simulator group (P < 0.001).

Conclusions

Simulator-based training did not translate to clinical competence in terms of accuracy and methodology of BP recordings in real-life settings. Notwithstanding its advantages, simulator-based BP training needs integration with human element to make it meaningful and relevant to clinical practice.
The Impact of Transport Modality on Efficiency of Simulated Neonatal Endotracheal Intubation
Authors: Geyer Emily D. , Walia Hina , Syed Faizaan , Hakim Mohammed , Tumin Dmitry , Tobias Joseph D. , Moharir Alok
Published: September 2019

Introduction

Although the transport of neonates is generally safe, adverse events can occur where equipment is a contributing factor. The aims of the study were to explore how the types of neonatal intensive care unit bed in use could impact a simulated emergency endotracheal intubation and to identify future areas for training and education.

Methods

The efficiency of endotracheal intubation performed during simulated neonatal transport using 3 different transport modalities (closed incubator bed, open incubator bed, and open radiant warmer bed) was assessed. Twenty participants were enrolled. Outcomes included time to intubation, intubation success, and ease of mannequin access and were compared using Wilcoxon signed-rank tests and McNemar exact tests.

Result

Median times to intubation were 59, 44, and 37 seconds with the incubator top closed, with the top open, and with the open radiant warmer bed, respectively. Intubation was slowest and subjective ease of access was most difficult with the incubator top closed.

Conclusions

Experienced anesthesia providers had significantly greater difficulty with simulated emergency endotracheal intubation when performing neonatal transport with the incubator top closed compared with available alternative modes.
Controlling and measuring dynamic odorant stimuli in the laboratory
Authors: Gorur-Shandilya Srinivas , Martelli Carlotta , Demir Mahmut , Emonet Thierry
Published: September 2019

Animals experience complex odorant stimuli that vary widely in composition, intensity and temporal properties. However, stimuli used to study olfaction in the laboratory are much simpler. This mismatch arises from the challenges in measuring and controlling them precisely and accurately. Even simple pulses can have diverse kinetics that depend on their molecular identity. Here, we introduce a model to describe how stimulus kinetics depend on the molecular identity of the odorant and the geometry of the delivery system. We describe methods to deliver dynamic odorant stimuli of several types, including broadly distributed stimuli that reproduce some of the statistics of naturalistic plumes, in a reproducible and precise manner. Finally, we introduce a method to calibrate a Photo-Ionization Detector to any odorant it can detect, using no additional components. Our approaches are affordable and flexible and can be used to advance our understanding of how olfactory neurons encode real-world odor signals.
Diauxie and co-utilization are not exclusive during growth in nutritionally complex environments
Authors: Perrin Elena , Giovannini Michele , Di Patti Francesca , Cardazzo Barbara , Carraro Lisa , Fagorzi Camilla , Ghini Veronica , Turano Paola , Fani Renato , Fondi Marco
Published: September 2019

The classic view of microbial growth strategy when multiple carbon sources are available states that they either metabolize them sequentially (diauxic growth) or simultaneously (co-utilization). This perspective is biased by the fact that this process has been mainly analysed in over-simplified laboratory settings, i.e. using a few model microorganisms and growth media containing only two alternative compounds. Models concerning the mechanisms and the dynamics regulating nutrients assimilation strategies in conditions that are closer to the ones found in natural settings (i.e. with many alternative carbon/energy sources) are missing. Here, we show that bacterial co-utilization and sequential uptake of multiple substrates can coexist when multiple possible nutrients are provided in the same growth experiment, leading to an efficient exploitation of nutritionally complex settings. The order of nutrient uptake is determined by the actual biomass yield (and growth rate) that can be achieved when the same compounds are provided as single carbon sources. Finally, using two alternative theoretical models we show that this complex metabolic phenotype can be explained by a tight regulation process that allows microbes to actively modulate the different assimilatory pathways involved.
Implicit versus explicit control strategies in models for vector-borne disease epidemiology
Authors: Demers Jeffery , Robertson Suzanne L. , Bewick Sharon , Fagan William F.
Published: September 2019

Throughout the vector-borne disease modeling literature, there exist two general frameworks for incorporating vector management strategies (e.g. area-wide adulticide spraying and larval source reduction campaigns) into vector population models, namely, the “implicit” and “explicit” control frameworks. The more simplistic “implicit” framework facilitates derivation of mathematically rigorous results on disease suppression and optimal control, but the biological connection of these results to realworld “explicit” control actions that could guide specific management actions is vague at best. Here, we formally define the biological and mathematical relationships between implicit and explicit control, and we provide detailed mathematical expressions relating the strength of implicit control to management-relevant properties of explicit control for four common intervention strategies. These expressions allow optimal control and sensitivity analysis results in existing implicit control studies to be interpreted in terms of real world actions. Our work reveals a previously unknown fact: implicit control is a meaningful approximation of explicit control only when resonance-like synergistic effects between multiple controls have a negligible effect on average population reduction. When non-negligible synergy exists, implicit control results, despite their mathematical tidiness, fail to provide accurate predictions regarding vector control and disease spread. The methodology we establish can be applied to study the interaction of phenological effects with control strategies, and we present a new technique for finding impulse control strategies that optimally reduce a vector population in the presence of seasonally oscillating model parameters. Collectively, these elements build an effective bridge between analytically interesting and mathematically tractable implicit control and the challenging, action-oriented explicit control.
The role of early acoustic experience in song discrimination
Authors: Hudson Emily J. , Creanza Nicole , Shizuka Daizaburo
Published: September 2019

Oscine songbirds are an ideal system for investigating how early experience affects behavior. Young songbirds face a challenging task: how to recognize and selectively learn only their own species’ song, often during a time-limited window. Because birds are capable of hearing birdsong very early in life, early exposure to song could plausibly affect recognition of appropriate models; however, this idea conflicts with the traditional view that song learning occurs only after a bird leaves the nest. Thus, it remains unknown whether natural variation in acoustic exposure prior to song learning affects the template for recognition. In a population where sister species, golden-crowned and white-crowned sparrows, breed syntopically, we found that nestlings discriminate between heterospecific and conspecific song playbacks prior to the onset of song memorization. We then asked whether natural exposure to more frequent or louder heterospecific song explained any variation in golden-crowned nestling response to heterospecific song playbacks. We characterized the amount of each species’ song audible in golden-crowned sparrow nests and showed that even in a relatively small area, the ratio of heterospecific to conspecific song exposure varies widely. However, although many songbirds hear and respond to acoustic signals before fledging, golden-crowned sparrow nestlings that heard different amounts of heterospecific song did not behave differently in response to heterospecific playbacks. This study provides the first evidence that song discrimination at the onset of song learning is robust to the presence of closely related heterospecifics in nature, which may be an important adaptation in sympatry between potentially interbreeding taxa.
Capturing the dynamics of peripersonal space by integrating sound propagation properties and expectancy effects
Authors: Hobeika Lise , Taffou Marine , Carpentier Thibaut , Warusfel Olivier , Viaud-Delmon Isabelle
Published: September 2019

Highlights

Logarithmically distributed auditory distances provides an apt granularity of PPS

Measuring expectation helps to interpret behavioral impact of audiotactile integration

Tactile RTs follows a logarithmic decrease due to audiotactile integration

Peripersonal space is better characterized and quantified with this refinement

Background

Humans perceive near space and far space differently. Peripersonal space, i.e. the space directly surrounding the body, is often studied using paradigms based on auditory-tactile integration. In these paradigms, reaction time to a tactile stimulus is measured in the presence of a concurrent auditory looming stimulus.

New Method

We propose here to refine the experimental procedure considering sound propagation properties in order to improve granularity and relevance of auditory-tactile integration measures. We used a logarithmic distribution of distances for this purpose. We also want to disentangle behavioral contributions of the targeted audiotactile integration mechanisms from expectancy effects. To this aim, we added to the protocol a baseline with a fixed sound distance.

Results

Expectation contributed significantly to overall behavioral responses. Subtracting it isolated the audiotactile effect due to the stimulus proximity. This revealed that audiotactile integration effects have to be tested on a logarithmic scale of distances, and that they follow a linear variation on this scale.

Comparison with Existing Method(s)

The granularity of the current method is more relevant, providing higher spatial resolution in the vicinity of the body. Furthermore, most of the existing methods propose a sigmoid fitting, which rests on the intuitive framework that PPS is an in-or-out zone. Our results suggest that behavioral effects follow a logarithmic decrease, thus a response graduated in space.

Conclusions

The proposed protocol design and method of analysis contribute to refine the experimental investigation of the factors influencing and modifying multisensory integration phenomena in the space surrounding the body.
Single mutation at a highly conserved region of chloramphenicol acetyltransferase enables thermophilic isobutyl acetate production directly from cellulose by Clostridium thermocellum
Authors: Seo Hyeongmin , Lee Jong-Won , Garcia Sergio , Trinh Cong T.
Published: September 2019

Background

Esters are versatile chemicals and potential drop-in biofuels. To develop a sustainable production platform, microbial ester biosynthesis using alcohol acetyltransferases (AATs) has been studied for decades. Volatility of esters endows thermophilic production with advantageous downstream product separation. However, due to the limited thermal stability of AATs known, the ester biosynthesis has largely relied on use of mesophilic microbes. Therefore, developing thermostable AATs is important for thermophilic ester production directly from lignocellulosic biomass by the thermophilic consolidated bioprocessing (CBP) microbes, e.g., Clostridium thermocellum.

Results

In this study, we engineered a thermostable chloramphenicol acetyltransferase from Staphylococcus aureus (CATSa) for enhanced isobutyl acetate production at elevated temperature. We first analyzed the broad alcohol substrate range of CATSa. Then, we targeted a highly conserved region in the binding pocket of CATSa for mutagenesis. The mutagenesis revealed that F97W significantly increased conversion of isobutanol to isobutyl acetate. Using CATSa F97W, we demonstrated the engineered C. thermocellum could produce isobutyl acetate directly from cellulose.

Conclusions

This study highlights that CAT is a potential thermostable AAT that can be harnessed to develop the thermophilic CBP microbial platform for biosynthesis of designer bioesters directly from lignocellulosic biomass.
The schizophrenia risk locus in SLC39A8 alters brain metal transport and plasma glycosylation
Authors: Mealer Robert G. , Jenkins Bruce G. , Chen Chia-Yen , Daly Mark J. , Ge Tian , Lehoux Sylvain , Marquardt Thorsten , Palmer Christopher D. , Park Julien H. , Parsons Patrick J. , Sackstein Robert , Williams Sarah E. , Cummings Richard D. , Scolnick Edward M. , Smoller Jordan W.
Published: September 2019

A common missense variant in SLC39A8 is convincingly associated with schizophrenia and several additional phenotypes. Homozygous loss-of-function mutations in SLC39A8 result in undetectable serum manganese (Mn) and a Congenital Disorder of Glycosylation (CDG) due to the exquisite sensitivity of glycosyltransferases to Mn concentration. Here, we identified several Mn-related changes in human carriers of the common SLC39A8 missense allele. Analysis of structural brain MRI scans showed a dose-dependent change in the ratio of T2w to T1w signal in several regions. Comprehensive trace element analysis confirmed a specific reduction of only serum Mn, and plasma protein N-glycome profiling revealed reduced complexity and branching. N-glycome profiling from two individuals with SLC39A8-CDG showed similar but more severe alterations in branching that improved with Mn supplementation, suggesting that the common variant exists on a spectrum of hypofunction with potential for reversibility. Characterizing the functional impact of this variant will enhance our understanding of schizophrenia pathogenesis and identify novel therapeutic targets and biomarkers of disease.

A common variant in the manganese transporter SLC39A8 is associated with numerous phenotypes including schizophrenia. Mealer et. al. presents an in-depth analysis of brain MRI and plasma glycomics in human carriers of the common variant, identifying several manganese-related changes with potential for diagnostic and therapeutic biomarker development.
Low miRNA abundance disables microRNA pathway in mammalian oocytes
Authors: Kataruka Shubhangini , Modrak Martin , Kinterova Veronika , Zeitler Daniela M. , Malik Radek , Kanka Jiri , Meister Gunter , Svoboda Petr
Published: September 2019

MicroRNAs (miRNAs) are ubiquitous small RNAs, which guide post-transcriptional gene repression in countless biological processes. However, the miRNA pathway in mouse oocytes appears inactive and is dispensable for development. We report that miRNAs do not accumulate like maternal mRNAs during oocyte growth. The most abundant miRNAs total tens of thousands of molecules in fully-grown oocytes, a number similar to that observed in much smaller fibroblasts. The lack of miRNA accumulation acts like miRNA knock-down, where miRNAs can engage their targets but are not abundant enough to produce significant silencing effect. Injection of 100,000 miRNAs was sufficient to restore reporter repression in oocytes, confirming that miRNA inactivity primarily stems from low miRNA abundance and not from an active repression of the miRNA pathwayper se. Similar situation was observed in rat, hamster, porcine, and bovine oocytes arguing that miRNA inactivity is not a mouse-specific adaptation but a common mammalian oocyte feature.
Elevated exposure to prenatal thyroid hormones affects embryonic mortality but has no clear effects into adulthood
Authors: Sarraude Tom , Hsu Bin-Yan , Groothuis Ton G.G. , Ruuskanen Suvi
Published: September 2019

Maternal thyroid hormones (THs) are known to be crucial in embryonic development in humans, but their influence on other, especially wild, animals remains poorly understood. So far, the studies that experimentally investigated the consequences of maternal THs focused on short-term effects, while early organisational effects with long-term consequences, as shown for other prenatal hormones, could also be expected. In this study, we aimed at investigating both the short- and long-term effects of prenatal THs in a bird species, the Japanese quailCoturnix japonica.We experimentally elevated yolk TH content (the prohormone T4, and its active metabolite T3, as well as a combination of both hormones). We analysed hatching success, embryonic development, offspring growth and oxidative stress as well as their potential organisational effects on reproduction, moult, and oxidative stress in adulthood. We found that eggs injected with both hormones had a higher hatching success compared with control eggs, suggesting conversion of T4into T3by the embryo. We detected no other clear short-term or long-term effects of yolk THs. These results suggest that yolk thyroid hormones are important in the embryonic stage of precocial birds, but other short- and long-term consequences remain unclear. Research on maternal thyroid hormones will greatly benefit from studies investigating how embryos use and respond to this maternal signalling. Long-term studies on prenatal THs in other taxa in the wild are needed for a better understanding of this hormone-mediated maternal pathway.
OR1D2 receptor mediates bourgeonal-induced human CatSper activation in a G-protein dependent manner
Authors: Cheng Yi-min , Luo Tao , Peng Zhen , Chen Hou-yang , Zhang Jin , Zeng Xu-Hui
Published: September 2019

During fertilization, sperm are guided towards eggs by physiological chemokines, a process named sperm chemotaxis. Human sperm chemotaxis is speculated to be mediated by olfactory receptor OR1D2 in a pathway requiring calcium influx. Bourgeonal, an artificial ligand of OR1D2, can activate CatSper, the primary calcium channel in human sperm. However, whether bourgeonal-induced CatSper activation requires OR1D2 and how CatSper is activated remain unclear. Herein, we show that OR1D2 antibody can inhibit bourgeonal-induced CatSper activation and sperm chemotaxis, proving that OR1D2 mediates bourgeonal-induced CatSper activation. Furthermore, bourgeonal-evoked CatSper currents can be greatly suppressed by either GDP-β-S or antibody of Gαs. Interestingly, bourgeonal can transiently increase sperm cAMP level, and this effect can be abolished by OR1D2 antibody. Consistently, bourgeonal-induced CatSper activation can be inhibited by membrane adenylate cyclases inhibitor. Overall, our results indicate that bourgeonal activates CatSper via OR1D2-G protein-cAMP pathway. Although CatSper can be activated by various physiological and environmental factors, this study represents the most recent progress proving that CatSper can be indirectly activated by extracellular regulators through a G-protein-dependent intracellular signaling pathway.
Confined filaments in soft vesicles - case of sickle red blood cells
Authors: Behera Arabinda , Kumar Gaurav , Sain Anirban
Published: September 2019

A semi-rigid filament confined in a soft vesicle of similar size can mutually deform each other. An important example from biological context is Hemoglobin-S (HbS) fibers which polymerize inside red blood cell (RBC). The fibers deform the healthy RBC into sickle-like shape causing difficulty in blood flow through capillaries. Using an area difference elasticity (ADE) model for RBC and a worm-like chain model for the HbS fibers, confined within RBC, we study the shape deformations at equilibrium. We also consider multiple filaments and find that confinement can generate multipolar RBC shapes and can also promote helical filament conformations. The same model, in different parameter regime, reproduces tubulation for phospholipid vesicles, as seen in experiments, when microtubules are confined in the vesicle. We conclude that with a decrease in the surface area to volume ratio, and membrane rigidity, the vesicle prefers tubulation over sickling. Our simulations can access various non-axisymmetric shapes, which have been observed experimentally, both in the context of sickle RBC and phospholipid vesicles, but have so far remained beyond the scope of variational methods.
Functional coupling between NMDA receptors and SK channels in rat hypothalamic magnocellular neurons: altered mechanisms during heart failure
Authors: Ferreira-Neto HC , Stern JE
Published: September 2019

Glutamatergic NMDA receptors (NMDAR) and small conductance Ca2+-activated K+ channels (SK) are critical synaptic and intrinsic mechanisms that regulate the activity of hypothalamic magnocellular neurosecretory neurons (MNNs) under physiological and pathological states, including lactation and heart failure (HF). Still, whether NMDARs and SK channels in MNNs are functionally coupled, and whether changes in this coupling contribute to exacerbated neuronal activity during HF is at present unknown. In the present study, we addressed these questions using patch-clamp electrophysiology and confocal Ca2+ imaging in a rat model of ischaemic HF. We found that in MNNs of sham rats, blockade of SK channels with apamin (200 nM) significantly increased the magnitude of an NMDAR-evoked current (INMDA). We also observed that blockade of SK channels potentiated NMDAR-evoked firing, and abolished spike frequency adaptation in MNNs from sham, but not HF rats. Importantly, a larger INMDA-ΔCa2+response was observed under basal conditions in HF compared to sham rats. Finally, we found that dialyzing recorded cells with the Ca2+ chelator BAPTA (10 mM) increased the magnitude of INMDA in MNNs from both sham and HF rats, and occluded the effects of apamin in the former. Together, our studies demonstrate that in MNNs, NMDARs and SK channels are functionally coupled, forming a local negative feedback loop that restrains the excitatory effect evoked by NMDAR activation. Moreover, our studies also support a blunted NMDAR-SK channel coupling in MNNs of HF rats, standing thus as a pathophysiological mechanism contributing to exacerbated hypothalamic neuronal activity during this prevalent neurogenic cardiovascular disease.
PCNA ubiquitination protects stalled replication forks from DNA2-mediated degradation by regulating Okazaki fragment maturation and chromatin assembly
Authors: Thakar Tanay , Leung Wendy , Nicolae Claudia M. , Clements Kristen E. , Shen Binghui , Bielinsky Anja-Katrin , Moldovan George-Lucian
Published: September 2019

Upon genotoxic stress, PCNA ubiquitination allows for replication of damaged DNA by recruiting lesion-bypass DNA polymerases. However, PCNA is also ubiquitinated during normal S-phase progression. By employing ubiquitination-deficient 293T and RPE1 cells generated through CRISPR/Cas9 genome editing, we show that this modification promotes cellular proliferation and suppression of genomic instability under normal growth conditions. Loss of PCNA-ubiquitination results in DNA2-mediated but MRE11-independent nucleolytic degradation of nascent DNA at stalled replication forks. This degradation is linked to defective gap-filling in the wake of the replication fork, and incomplete Okazaki fragment synthesis and maturation, thus interfering with efficient PCNA unloading by ATAD5 and subsequent nucleosomal deposition by CAF-1. Moreover, concomitant loss of PCNA-ubiquitination and BRCA2 results in a synergistic increase in nascent DNA degradation and sensitivity to PARP-inhibitors. In conclusion, we show that by ensuring efficient Okazaki fragment maturation, PCNA-ubiquitination protects fork integrity and promotes the resistance of BRCA-deficient cells to PARP-inhibitors.
Gamma-protocadherin localization at the synapse corresponds to parameters of synaptic maturation
Authors: LaMassa Nicole , Sverdlov Hanna , Mambetalieva Aliya , Shapiro Stacy , Bucaro Michael , Fernandez-Monreal Monica , Phillips Greg R.
Published: September 2019

Clustered protocadherins (Pcdhs) are a large family of ~60 cadherin-like proteins (divided into the subclasses α, β, and γ) that compose a surface “barcode” in individual neurons. The code is generated through combinatorial expression via epigenetic regulation at a large gene cluster that encodes the molecules. During early neural development, Pcdhs were shown to mediate dendrite self-avoidance in some neuronal types through a still uncharacterized anti-adhesive mechanism. Pcdhs were also shown to be important for dendritic complexity in cortical neurons likely through a pro-adhesive mechanism. Pcdhs have also been postulated to participate in synaptogenesis and the specificity of connectivity. Some synaptic defects were noted in knockout animals, including synaptic number and physiology, but the role of these molecules in synaptic development is not understood. The effects of Pcdh knockout on dendritic patterning may present a confound to studying synaptogenesis. We have shown previously in vivo and in cultures that Pcdh-γs are highly enriched in intracellular compartments located in dendrites and spines with localization at only a few synaptic clefts. To gain insight into how Pcdh-γs might affect synapses, we compared synapses that harbored endogenous Pcdh-γs versus those that did not for parameters of synaptic maturation including pre- and postsynaptic size, postsynaptic perforations, and spine morphology by light microscopy in cultured hippocampal neurons and by serial section immuno-electron microscopy in hippocampal CA1. In mature neurons, synapses immunopositive for Pcdh-γs were found to be larger in diameter with more frequent perforations. Analysis of spines in cultured neurons revealed that mushroom spines were more frequently immunopositive for Pcdh-γs at their tips than thin spines. Taken together, these results suggest that Pcdh-γ function at the synapse may be related to promotion of synaptic maturation and stabilization.
Automethylation of PRC2 promotes H3K27 methylation and is impaired in H3K27M pediatric glioma
Authors: Lee Chul-Hwan , Yu Jia-Ray , Granat Jeffrey , Saldaña-Meyer Ricardo , Andrade Joshua , LeRoy Gary , Jin Ying , Lund Peder , Stafford James M. , Garcia Benjamin A. , Ueberheide Beatrix , Reinberg Danny
Published: September 2019

The histone methyltransferase activity of PRC2 is central to the formation of H3K27me3-decorated facultative heterochromatin and gene silencing. In addition, PRC2 has been shown to automethylate its core subunits, EZH1/EZH2 and SUZ12. Here, we identify the lysine residues at which EZH1/EZH2 are automethylated with EZH2-K510 and EZH2-K514 being the major such sites in vivo. Automethylated EZH2/PRC2 exhibits a higher level of histone methyltransferase activity and is required for attaining proper cellular levels of H3K27me3. While occurring independently of PRC2 recruitment to chromatin, automethylation promotes PRC2 accessibility to the histone H3 tail. Intriguingly, EZH2 automethylation is significantly reduced in diffuse intrinsic pontine glioma (DIPG) cells that carry a lysine-to-methionine substitution in histone H3 (H3K27M), but not in cells that carry either EZH2 or EED mutants that abrogate PRC2 allosteric activation, indicating that H3K27M impairs the intrinsic activity of PRC2. Our study demonstrates a PRC2 self-regulatory mechanism through its EZH1/2-mediated automethylation activity.
Crystal structure of Mo-substituted lanthanum tungstate La5.4W1−y
Mo
y
O12−δ (0 ≤ y ≤ 0.2) studied by X-ray and neutron diffraction
Authors: Fantin Andrea , Scherb Tobias , Seeger Janka , Schumacher Gerhard , Gerhards Uta , Ivanova Mariya E. , Meulenberg Wilhelm A. , Dittmeyer Roland , Banhart John
Published: September 2019

A determination of the detailed crystal structure of an Mo-substituted lanthanum tungstate series, La6−x
W1−y
Mo
y
O12−δ (0 ≤ y ≤ 0.2, δ is the oxygen deficiency), is presented. Material of composition La5.4W0.8Mo0.2O12−δ (y = 0.2) produced by the citrate-complexation route based on the Pechini method was investigated by high-resolution X-ray diffraction and neutron diffraction in the temperature range 10 ≤ T ≤ 298 K. The results are compared with a non-substituted material La5.4WO12−δ. A structural model established earlier for lanthanum tungstates and Re-substituted lanthanum tungstates is confirmed, according to which the Wyckoff site shared by La and W is split with half site occupancies (Fm\bar 3m space group, 48h site) and also accommodates Mo atoms. Substitution of W by up to 20 mol% Mo does not change the face-centred cubic lattice: Mo atoms substitute W statistically on both 4a and 48h Wyckoff sites of the crystal structure, which is described by the Fm\bar 3m space group. These results were obtained from the combination of the average neutron-scattering length and average X-ray scattering power procedures with electron-probe micro-analysis. The temperature dependence of bond lengths in dry and wet (D2O) conditions shows that vacant oxygen sites are located on the 32f Wyckoff sites also in Mo-substituted lanthanum tungstates, and that the bond lengths between La on 4b and O on 32f increase with increasing pO2 and pD2O, reflecting the filling of oxygen vacancies and the increase in coordination of La on 4b.