Stakeholder perspectives following implementation of Vietnam's first speech-language pathology degrees: recommendations for future curriculum development

PURPOSE

To investigate perspectives of multiple stakeholders involved in development and delivery of Vietnam's first speech-language pathology degrees and derive recommendations for future degrees in Vietnam and other Majority World countries.

METHODS

An exploratory-descriptive qualitative research design using focus groups and individual semi-structured interviews in the preferred language (English or Vietnamese) was used, with 70 participants from five stakeholder groups: project managers, students, academic educators, placement supervisors and interpreters. Transcriptions were analysed using thematic network analysis.

RESULTS

Analysis identified five organising themes: (1) People enjoyed working with/learning from others; (2) Benefits from/to stakeholders; (3) The pandemic impacted program delivery and learning; (4) Practical challenges; (5) Preparation with flexibility required for success and sustainability. From the five organising themes, one synthesising global theme was developed, conveying that satisfying international collaborations require preparation, support, high quality interpreting, and management of challenges.

CONCLUSIONS

Recommendations highlight the need for preparation, collaboration, support to manage challenges, flexibility, recognition for placement supervisors and high-quality interpreting. The recommendations are of relevance to other organisations engaged in development of professional degrees in Majority World countries. Future research would benefit from a critical investigation of the diverse perspectives of stakeholders involved in the development and implementation of international curricula.

Using Machine Learning to Determine a Suitable Patient Population for Anakinra for the Treatment of COVID-19 Under the Emergency Use Authorization

A randomized, double-blind, placebo-controlled study (SAVEMORE trial) provided data to support an Emergency Use Authorization (EUA) of anakinra in hospitalized adults with positive results of direct severe acute respiratory syndrome-coronavirus 2 viral testing with pneumonia requiring supplemental oxygen (low- or high-flow oxygen) who are at risk of progressing to severe respiratory failure and likely to have an elevated plasma soluble urokinase plasminogen activator receptor (suPAR). Currently, the suPAR assay is not commercially available in the United States. An alternative method was needed to identify patients that best reflect the population in the clinical trial selected based on suPAR level ≥ 6 ng/mL at baseline. A machine learning approach based on data from the SAVEMORE trial was used to develop a scoring rule to identify patients who are likely to have a suPAR level ≥ 6 ng/mL at baseline. External validation of the scoring rule was conducted with data from a different trial (SAVE). This clinical scoring rule with high positive predictive value, high specificity, reasonable sensitivity, and biological relevance is expected to identify patients who are likely to have an elevated suPAR level ≥ 6 ng/mL at baseline. As such, it is included in the EUA to identify patients that fall within the authorized population for whom the known and potential benefits outweigh the known and potential risks of anakinra.

A maximum of two readily releasable vesicles per docking site at a cerebellar single active zone synapse

Recent research suggests that in central mammalian synapses, active zones contain several docking sites acting in parallel. Before release, one or several synaptic vesicles (SVs) are thought to bind to each docking site, forming the readily releasable pool (RRP). Determining the RRP size per docking site has important implications for short-term synaptic plasticity. Here, using mouse cerebellar slices, we take advantage of recently developed methods to count the number of released SVs at single glutamatergic synapses in response to trains of action potentials (APs). In each recording, the number of docking sites was determined by fitting with a binomial model the number of released SVs in response to individual APs. After normalization with respect to the number of docking sites, the summed number of released SVs following a train of APs was used to estimate of the RRP size per docking site. To improve this estimate, various steps were taken to maximize the release probability of docked SVs, the occupancy of docking sites, as well as the extent of synaptic depression. Under these conditions, the RRP size reached a maximum value close to two SVs per docking site. The results indicate that each docking site contains two distinct SV-binding sites that can simultaneously accommodate up to one SV each. They further suggest that under special experimental conditions, as both sites are close to full occupancy, a maximal RRP size of two SVs per docking site can be reached. More generally, the results validate a sequential two-step docking model previously proposed at this preparation.

Comparing the Frequency of Culture-Positive Late Onset Sepsis With the Use of Ceftazidime Versus Cefotaxime in the NICU

OBJECTIVE

As broader spectrum antibiotics have been associated with adverse effects, our study evaluated whether the frequency of culture-positive late-onset sepsis (LOS) and multidrug resistant (MDR) infections were increased with the use of ceftazidime as compared with cefotaxime in the neonatal intensive care unit (NICU).

METHODS

This was a multihospital, retrospective chart review of patients who received at least 24 hours of ceftazidime or cefotaxime in the NICU between December 1, 2012 and August 31, 2021. Patients were excluded from analysis if they expired during the admission, had an incomplete history, positive cultures for an MDR infection prior to receiving either antibiotic, or received the alternate antibiotic within the same treatment course.

RESULTS

A total of 334 patients were included for analysis (ceftazidime, n = 147; cefotaxime, n = 187). The average birth weight was lower in the ceftazidime cohort compared with the cefotaxime cohort [1.46 kg (95% CI, 1.29-1.63 kg) versus 1.93 kg (95% CI, 1.75-2.11 kg), p = 0.0002] with a corresponding lower gestational age [28.9 weeks (95% CI, 28.0-29.9 weeks) versus 31.7 weeks (95% CI, 30.8-32.6 weeks), p = 0.0001]. Adjusting for baseline differences showed a protective effect for ceftazidime (OR = 0.32; 95% CI, 0.16-0.62; p = 0.0009). There was no statistically significant difference in the frequency of MDR infections between the cohorts (OR = 0.25; 95% CI, 0.053-1.14; p = 0.07), however this study was underpowered to detect the difference noted.

CONCLUSIONS

Ceftazidime appears to be a safe and effective alternative treatment option compared with cefotaxime in the NICU with no increase in the risk of culture-positive LOS or MDR infections.

Hydrogen Bonding Parameters by Rapid Colorimetric Assessment: Evaluation of Structural Components Found in Biological Ligands and Organocatalysts

Hydrogen bonding is a key molecular interaction in biological processes, drug delivery, and catalysis. This report describes a high throughput UV-Vis spectroscopic method to measure hydrogen bonding capacity using a pyrazinone sensor. This colormetric sensor reversibly binds to a hydrogen bond donor, resulting in a blue shift as additional equivalents of donor are added. Titration with excess equivalents of donor is used to determine the binding coefficient, ln(Keq ). Over 100 titrations were performed for a variety of biologically relevant compounds. This data enabled development a multiple linear regression model that is capable of predicting 95 % of ln(Keq ) values within 1 unit, allowing for the estimation of hydrogen bonding affinity from a single measurement. To show the effectiveness of the single point measurements, hydrogen bond strengths were obtained for a set of carboxylic acid bioisosteres. The values from the single point measurements were validated with full titrations.

Prioritized docking of synaptic vesicles provided by a rapid recycling pathway

It is known that endocytosis of synaptic vesicles, and docking of these vesicles to their release sites, are regulated in a similar manner, but it has remained unclear whether the two processes are linked mechanistically. To address this issue, we studied vesicular release during repeated trains of presynaptic action potentials. Synaptic responses decreased when the inter-train interval was shortened, indicating a gradual exhaustion of the recycling pool of vesicles, with a resting size of 180 vesicles per active zone. This effect was counteracted by the activation of a rapid recycling pathway, which utilized vesicles ∼10 s after endocytosis and was able to generate 200 vesicles per active zone. Blocking the rapid recycling of vesicles revealed an enhanced probability of docking of recently endocytosed vesicles compared to those coming from the recycling pool. Thus, our results demonstrate a differential sorting of vesicles inside the readily releasable pool depending on their origin.

Helicobacter pylori (H. pylori) risk factor analysis and prevalence prediction: a machine learning-based approach

Background

Although previous epidemiological studies have examined the potential risk factors that increase the likelihood of acquiring Helicobacter pylori infections, most of these analyses have utilized conventional statistical models, including logistic regression, and have not benefited from advanced machine learning techniques.

Objective

We examined H. pylori infection risk factors among school children using machine learning algorithms to identify important risk factors as well as to determine whether machine learning can be used to predict H. pylori infection status.

Methods

We applied feature selection and classification algorithms to data from a school-based cross-sectional survey in Ethiopia. The data set included 954 school children with 27 sociodemographic and lifestyle variables. We conducted five runs of tenfold cross-validation on the data. We combined the results of these runs for each combination of feature selection (e.g., Information Gain) and classification (e.g., Support Vector Machines) algorithms.

Results

The XGBoost classifier had the highest accuracy in predicting H. pylori infection status with an accuracy of 77%—a 13% improvement from the baseline accuracy of guessing the most frequent class (64% of the samples were H. Pylori negative.) K-Nearest Neighbors showed the worst performance across all classifiers. A similar performance was observed using the F1-score and area under the receiver operating curve (AUROC) classifier evaluation metrics. Among all features, place of residence (with urban residence increasing risk) was the most common risk factor for H. pylori infection, regardless of the feature selection method choice. Additionally, our machine learning algorithms identified other important risk factors for H. pylori infection, such as; electricity usage in the home, toilet type, and waste disposal location. Using a 75% cutoff for robustness, machine learning identified five of the eight significant features found by traditional multivariate logistic regression. However, when a lower robustness threshold is used, machine learning approaches identified more H. pylori risk factors than multivariate logistic regression and suggested risk factors not detected by logistic regression.

Conclusion

This study provides evidence that machine learning approaches are positioned to uncover H. pylori infection risk factors and predict H. pylori infection status. These approaches identify similar risk factors and predict infection with comparable accuracy to logistic regression, thus they could be used as an alternative method.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07625-7.

Graphical User Interface for Calculating Wave Intensity from Cardiac Catheterization Measurements

Wave intensity analysis (WIA) as a framework to assess cardiovascular hemodynamics has been successfully used in many clinical applications. Typically, wave intensity calculations require the simultaneous acquisition of blood velocity and blood pressure at the same vascular site. Unfortunately, many hemodynamic parameters that are used to monitor pre-operative patient hemodynamic state use both invasively acquired blood pressure measurements in catheterization laboratory and non-invasively acquired blood velocity measurements. To utilize wave intensity analysis to assess patients undergoing cardiac interventional procedures, we have developed a graphical user interface (GUI) that uses standard clinical measurements which include invasive blood pressure waveforms and Doppler echocardiography images to calculate wave intensity parameters. The GUI consists of three main subroutines that allow clinicians to import raw data and extract and analyze the blood pressure and blood velocity signals separately. Using the electrocardiogram signals as an alignment marker, the re-formatted signals are aligned, and wave intensity is calculated. Wave intensity features such as forward compression wave (FCW), forward expansion wave (FEW) and wave speed are calculated and output in a table for statistical analysis. The GUI represents the first attempt to create a program that encourages clinicians to use WIA for hemodynamic assessment in patients undergoing cardiac catheterization procedures with the data they have already procured.

Spontaneous and action potential-evoked Ca2+ release from endoplasmic reticulum in neocortical synaptic boutons

Although the endoplasmic reticulum (ER) is present throughout axons, and IP3 and ryanodine receptors are widely expressed in nerve terminals, whether Ca2+ release from presynaptic stores contributes to action potential (AP)-evoked Ca2+ transients remains controversial. We investigated the release of Ca2+ from ER stores in boutons en passant of neocortical layer 5 pyramidal neurons. A hallmark of these stores is that they spontaneously release Ca2+ at a low frequency. Using a high-affinity Ca2+ indicator, we documented and characterised such spontaneous Ca2+ transients (sCaTs), which occurred at a rate of ~0.2 per min and raised the intracellular Ca2+ concentration ([Ca2+]i) by ~2 µM in the absence of exogenous buffers. Caffeine increased the average frequency of sCaTs by 90%, without affecting their amplitude and decay kinetics. Therefore, presynaptic ryanodine receptors were likely involved. To determine if presynaptic ER stores contribute to intracellular Ca2+ accumulation during repetitive stimulation, we measured [Ca2+]i during 2 s long trains of APs evoked at 10-50 Hz. We found that for frequencies <20 Hz, [Ca2+]i reached a steady state within ~500 ms after stimulation onset. However, for higher frequencies, [Ca2+]i continued to increase with AP number, suggesting that the rate of Ca2+ entry exceeded the rate of clearance. Comparison between measured and predicted values indicates supralinear summation of Ca2+. Block of the sarco/endoplasmic reticulum Ca2+-ATPase reduced the supralinearity of summation, without reducing the amplitude of a single AP-evoked Ca2+ transient. Together, our results implicate presynaptic ER stores as a source of Ca2+ during repetitive stimulation.

Calcium-dependent docking of synaptic vesicles

The concentration of calcium ions in presynaptic terminals regulates transmitter release, but underlying mechanisms have remained unclear. Here we review recent studies that shed new light on this issue. Fast-freezing electron microscopy and total internal reflection fluorescence microscopy studies reveal complex calcium-dependent vesicle movements including docking on a millisecond time scale. Recordings from so-called 'simple synapses' indicate that calcium not only triggers exocytosis, but also modifies synaptic strength by controlling a final, rapid vesicle maturation step before release. Molecular studies identify several calcium-sensitive domains on Munc13 and on synaptotagmin-1 that are likely involved in bringing the vesicular and plasma membranes closer together in response to calcium elevation. Together, these results suggest that calcium-dependent vesicle docking occurs in a wide range of time domains and plays a crucial role in several phenomena including synaptic facilitation, post-tetanic potentiation, and neuromodulator-induced potentiation.

Grain filling in barley relies on developmentally controlled programmed cell death

Cereal grains contribute substantially to the human diet. The maternal plant provides the carbohydrate and nitrogen sources deposited in the endosperm, but the basis for their spatial allocation during the grain filling process is obscure. Here, vacuolar processing enzymes have been shown to both mediate programmed cell death (PCD) in the maternal tissues of a barley grain and influence the delivery of assimilate to the endosperm. The proposed centrality of PCD has implications for cereal crop improvement.

Radchuk et al. report on the role of vacuolar processing enzymes (VPEs) in mediating programmed cell death (PCD) in the maternal tissues of a barley grain and influencing the delivery of assimilate to the endosperm. This study presents a means of increasing the efficiency of the grain filling process in the major cereal crop species by manipulating the timing of PCD.

Multimodality adjuvant therapy and survival outcomes in stage I–IV uterine carcinosarcoma

Objectives

Uterine carcinosarcoma is a rare, aggressive form of uterine cancer with a high recurrence rate and poor survival at all stages. We sought to evaluate the outcomes of patients treated with chemotherapy versus a combination of chemotherapy and radiation (chemoradiation) to determine survival.

Methods

A multicenter retrospective analysis of patients with stage I–IV carcinosarcoma was conducted from January 2000 to December 2017. Inclusion criteria were primary surgical management, defined as hysterectomy ± salpingo-oophorectomy, comprehensive surgical staging and/or tumor debulking, followed by adjuvant chemotherapy or chemoradiation. Differences in the frequencies of stage, cytoreduction status, treatment delays and sites of disease recurrence were identified using Pearson’s χ2 test. Progression-free and overall survival rates were calculated using Kaplan-Meier estimates.

Results

Final analysis included 148 patients; 40.5% (n=60) chemotherapy and 59.5% (n=88) chemoradiation. The mean age was 67 years (range 39–89). Stage distribution included 24.3% stage I, 12.2% stage II, 37.2% stage III, and 26.3% stage IV. There was no difference in the frequency of stage (p=0.81), cytoreduction status (p=0.61), treatment delays (p=0.57), or location of recurrence (p=0.97) between cohorts. The most frequent location of recurrence was the abdomen (50.0%). The median progression-free survival favored chemoradiation over chemotherapy (15 vs 11 months, respectively), as did the median overall survival (26 vs 20 months, respectively). Chemoradiation was associated with a statistically significant improvement in 2 year progression-free survival (22.5% vs 13.6%; p=0.006) and 2 year overall survival (50.0% vs 35.6%; p=0.018) compared with chemotherapy alone. On subanalysis of patients receiving chemoradiation, ‘sandwich sequencing’ (chemotherapy–radiation–chemotherapy) was associated with superior overall survival compared with alternate therapy sequences (chemotherapy–radiation and radiation–chemotherapy) (34 months vs 14 months and 14 months, respectively) (p=0.038).

Conclusions

Chemoradiation was associated with improvement in both progression-free and overall survival for all stages of carcinosarcoma compared with chemotherapy alone.

Acute Kidney Injury During Treatment with Intravenous Acyclovir for Suspected or Confirmed Neonatal Herpes Simplex Virus Infection

OBJECTIVE

To describe the epidemiology of and risk factors associated with acute kidney injury (AKI) during acyclovir treatment in neonates and infants.

STUDY DESIGN

We conducted a multicenter (n = 4), retrospective cohort study of all hospitalized infants age <60 days treated with intravenous acyclovir (≥1 dose) for suspected or confirmed neonatal herpes simplex virus disease from January 2011 to December 2015. Infants with serum creatinine measured both before acyclovir (baseline) and during treatment were included. We classified AKI based on changes in creatinine according to published neonatal AKI criteria and performed Cox regression analysis to evaluate risk factors for AKI during acyclovir treatment.

RESULTS

We included 1017 infants. The majority received short courses of acyclovir (median, 5 doses). Fifty-seven infants (5.6%) developed AKI during acyclovir treatment, with an incidence rate of AKI at 11.6 per 1000 acyclovir days. Cox regression analysis identified having confirmed herpes simplex virus disease (OR, 4.35; P = .002), receipt of ≥2 concomitant nephrotoxic medications (OR, 3.07; P = .004), receipt of mechanical ventilation (OR, 5.97; P = .001), and admission to an intensive care unit (OR, 6.02; P = .006) as risk factors for AKI during acyclovir treatment.

CONCLUSIONS

Among our cohort of infants exposed to acyclovir, the rate of AKI was low. Sicker infants and those exposed to additional nephrotoxic medications seem to be at greater risk for acyclovir-induced toxicity and warrant closer monitoring.

Incomplete vesicular docking limits synaptic strength under high release probability conditions

Central mammalian synapses release synaptic vesicles in dedicated structures called docking/release sites. It has been assumed that when voltage-dependent calcium entry is sufficiently large, synaptic output attains a maximum value of one synaptic vesicle per action potential and per site. Here we use deconvolution to count synaptic vesicle output at single sites (mean site number per synapse: 3.6). When increasing calcium entry with tetraethylammonium in 1.5 mM external calcium concentration, we find that synaptic output saturates at 0.22 vesicle per site, not at 1 vesicle per site. Fitting the results with current models of calcium-dependent exocytosis indicates that the 0.22 vesicle limit reflects the probability of docking sites to be occupied by synaptic vesicles at rest, as only docked vesicles can be released. With 3 mM external calcium, the maximum output per site increases to 0.47, indicating an increase in docking site occupancy as a function of external calcium concentration.

1510. Improving the Management of Pediatric Complicated Pneumonia

Background

Pneumonia is a leading cause of pediatric hospitalization in the United States. Our Antimicrobial Stewardship Program (ASP) recognized significant variation in the management of pediatric complicated pneumonia. We developed and implemented a quality improvement (QI) intervention to align the management of complicated pneumonia with national guidelines and compared the medical care and clinical outcomes between a pre-intervention period and two post-intervention periods.

Methods

We queried Webi Universe for all ICD-9 and ICD-10-related admissions for pneumonia at our facility from November 15, 2015 to February 28, 2019. Manual chart review was done to extract clinical points of interest and to ensure that all included patients met inclusion criteria. Our first intervention (period 1) consisted of education to providers to increase use of chest tubes instilled with fibrinolytics and to decrease empiric antistaphylococcal therapy. Our second intervention (period 2) consisted of a care process model which codified the standardized management made by the first intervention, followed by several didactic sessions.

Results

29 patients were identified in the pre-intervention period, 11 in post-intervention period 1, and 27 in post-intervention period 2. Streptococcal species were the most common pathogens recovered in all periods. Following our interventions the number of video-assisted thorascopic procedures to drain complicated parapneumonic effusions decreased three-fold in favor of chest tubes instilled with fibrinolytics (P < 0.01). Our interventions also reduced empiric antistaphylococcal therapy within the first 48 hours of admission (P = 0.02) and decreased the use of empiric vancomycin three-fold (P = 0.01). Our interventions did not affect the median length of stay, frequency of pulmonary complications, number of 30-day readmissions, or duration of antimicrobial therapy.

Conclusion

Our ASP’s QI intervention decreased surgical drainage of complicated parapneumonic effusions and decreased the use of empiric antistaphylococcal agents without an increase in complications or readmissions. Opportunities remain to decrease the use of multiple antimicrobial agents within the first 48 hours of admission and to decrease the empiric use of antistaphylococcal therapy.

Disclosures

All authors: No reported disclosures.

1506. Outcomes of Standardized Neonatal Cephalexin Dosing

Background

The optimal dosing of cephalexin in infants ≤90 days old is not well known. Our Antimicrobial Stewardship Program (ASP) standardized cephalexin dosing for inpatients ≥30 days old using available literature and released an antimicrobial dosing guideline in September 2016. Recommended antimicrobial dosing for inpatients <30 days old followed in November 2017. We reviewed the indications, cephalexin dosing, and clinical outcomes of patients before and after the release of our ASP’s cephalexin dosing guidelines.

Methods

Webi Universe was queried for cephalexin orders for inpatients ≤ 90 days old at the Inova Children’s Hospital from January 2016 to November 2018. Manual chart review extracted clinical points of interest and ensured that inclusion criteria were met. For patients <30 days old, the pre-intervention period was January 2016 to October 2017 and the post-intervention period was November 2017 to October 2018. For patients ≥30 days old the pre-intervention period was January 2016 to August 2016 and the post-intervention period was September 2016 to October 2018. Aggregate data from the two pre-intervention and two post-intervention periods were pooled, respectively.

Results

41 patients were identified: 25 in the pre-intervention period and 16 in the post-intervention period. The median age of patients in the pre-intervention period was 16 days compared with 31 days in the post-intervention period (P = 0.02). No patients had acute kidney injury requiring cephalexin renal dosing. Skin and soft-tissue infections (18) and urinary tract infections (10) were the most common infections in both periods. 24% of patients received the recommended cephalexin dose in the pre-intervention period compared with 63% in the post-intervention period (P = 0.02). Logistic regression controlling for pathogens and area of care showed that patient age predicted the use of recommended cephalexin dosing (OR 1.1, 95% CI: 1.01–1.21). There were no deaths or recrudescent infections.

Conclusion

Our ASP’s interventions improved adherence to standardized cephalexin dosing in inpatients ≤90 days old without any adverse clinical outcomes. Patients ≥30 days old were more likely to receive recommended cephalexin dosing. Opportunities remain to best define the optimal dose of cephalexin in infants ≤90 days old.

Disclosures

All authors: No reported disclosures.

Credentialing of Pediatric Pharmacists in Collaborative Drug Therapy Management

Pediatric clinical pharmacists have evolved over the last 2 decades and have proven to be a key player in the multidisciplinary team. The American College of Clinical Pharmacy recently published (in 2015) a position statement on collaborative drug therapy management and comprehensive medication management. The Council on Credentialing in Pharmacy published a 2014 article on credentialing and privileging of pharmacists. Neither offered requirements for pediatric pharmacists in training and credentialing. This position statement provides a detailed outline defining adequate training for a pediatric clinical pharmacist in order to participate in collaborative drug therapy management for pediatric patients.

Opioid Use in Children

Limited guidance on opioid use exists in the pediatric population, causing medication safety concerns for pain management in children and adolescents. Opioid misuse and use disorder continue to greatly affect adolescents and young adults in the United States, furthering the apprehension of their use. Pediatric Pharmacy Advocacy Group (PPAG) recommends pharmacists contribute their knowledge to pain management in children, including the discussion of appropriate use of non-opioid alternatives for pain and when to recommend coprescribing of naloxone. PPAG also supports the review of electronic prescription drug-monitoring programs prior to opioid prescribing and dispensing by both prescribers and pharmacists. Education by pharmacists of children and their families regarding proper administration, storage, and disposal, as well as the awareness of opioid misuse and use disorder among adolescents and young adults, is key to prevention. If opioid use disorder is diagnosed, PPAG encourages improved access among adolescents to evidence-based medications including methadone, buprenorphine, and naltrexone. Furthermore, pharmacists should assist in screening and referral to evidence-based treatment.

609. Acute Kidney Injury During Treatment with Intravenous Acyclovir (AKITA) for Suspected Neonatal Herpes Simplex Virus Infection

Background

Intravenous (IV) acyclovir is often administered empirically in neonates with suspected herpes simplex virus (HSV) disease. Acute kidney injury (AKI) can occur within 1–2 days after starting acyclovir due to crystal nephropathy, but the epidemiology of acyclovir-associated AKI in infants is not well-described. Our objective was to detail the incidence and timing of AKI among acyclovir-exposed infants.

Methods

We identified all hospitalized infants age <60 days treated with ≥1 dose of IV acyclovir for suspected or confirmed neonatal HSV disease from January 2011 to December 2015 at four US hospitals. Subjects were included if they had both a baseline (lowest value obtained before initiation of acyclovir) and follow-up serum creatinine (SCr; obtained after at least one dose of acyclovir [Day 0] through 48 hours after completion) recorded. Infants with congenital kidney disease were excluded. We defined AKI using Kidney Disease: Improving Global Outcomes SCr criteria: ≥50% increase from baseline, or ≥0.3 mg/dL change within any 48-hour period.

Results

We identified 3,374 infants who received IV acyclovir, 1,535 of whom (45.5%) had SCr as defined for inclusion in our analyses (range 52–898 infants per hospital); 50% were white, 44% were female, and the median gestational age was 37 weeks (IQR 35 – 39). On acyclovir Day 0, the median age was 6 days (IQR 2–18), and 50.0% (n = 768) were admitted to the NICU. The median acyclovir dose was 59.5 mg/kg/day (IQR: 55.8–61.2) and the median duration of treatment was 3 days (IQR: 3–6). Thirty-two infants had confirmed HSV disease (10 CNS, 14 disseminated, and eight skin, eye, and mucous membrane disease). In all, 96 infants (6.3%) had AKI detected after acyclovir initiation including 62 (64.5%) on Day 0, 20 (20.8%) on Day 1 or 2, and 14 (14.6%) on/after Day 3. Of those with AKI on Day 1 or later, 41% (n = 14) had Stage 2 AKI (doubling of SCr or more from baseline). Seven of 32 (21.8%) infants with confirmed HSV had AKI including 4 on Day 0, 2 on Days 1–2, and 1 on Day 12.

Conclusion

The incidence of AKI among infants treated with IV acyclovir in our study was low. Most AKI was detected soon after acyclovir initiation, potentially owing to more severe illness at the start of treatment and/or drug toxicity, but AKI also developed later. SCr monitoring should be considered throughout acyclovir treatment in infants.

Disclosures

B. L. Haltzman, Pfizer, Inc.: Study Coordinator, Salary. K. J. Downes, Pfizer, Inc.: Investigator, Research support. Merck, Inc.: Investigator, Research support. S. E. Coffin, Merck, Inc.: Investigator, Research support.

Diffusion of Ca2+ from Small Boutons en Passant into the Axon Shapes AP-Evoked Ca2+ Transients

Not only the amplitude but also the time course of a presynaptic Ca²⁺ transient determine multiple aspects of synaptic transmission. In small bouton-type synapses, the mechanisms underlying the Ca²⁺ decay kinetics have not been fully investigated. Here, factors that shape an action-potential-evoked Ca²⁺ transient were quantitatively studied in synaptic boutons of neocortical layer 5 pyramidal neurons. Ca²⁺ transients were measured with different concentrations of fluorescent Ca²⁺ indicators and analyzed based on a single-compartment model. We found a small endogenous Ca²⁺-binding ratio (7 ± 2) and a high activity of Ca²⁺ transporters (0.64 ± 0.03 ms^-1), both of which enable rapid clearance of Ca²⁺ from the boutons. However, contrary to predictions of the single-compartment model, the decay time course of the measured Ca²⁺ transients was biexponential and became prolonged during repetitive stimulation. Measurements of [Ca²⁺]_i along the adjoining axon, together with an experimentally constrained model, showed that the initial fast decay of the Ca²⁺ transients predominantly arose from the diffusion of Ca²⁺ from the boutons into the axon. Therefore, for small boutons en passant, factors like terminal volume, axon diameter, and the concentration of mobile Ca²⁺-binding molecules are critical determinants of Ca²⁺ dynamics and thus Ca²⁺-dependent processes, including short-term synaptic plasticity.

Vacuolar processing enzyme 4 contributes to maternal control of grain size in barley by executing programmed cell death in the pericarp

The angiosperm embryo and endosperm are limited in space because they grow inside maternal seed tissues. The elimination of cell layers of the maternal seed coat by programmed cell death (PCD) could provide space and nutrition to the filial organs. Using the barley (Hordeum vulgare L.) seed as a model, we elucidated the role of vacuolar processing enzyme 4 (VPE4) in cereals by using an RNAi approach and targeting the enzymatic properties of the recombinant protein. A comparative characterization of transgenic versus wild-type plants included transcriptional and metabolic profiling, flow cytometry, histology and nuclear magnetic imaging of grains. The recombinant VPE4 protein exhibited legumain and caspase-1 properties in vitro. Pericarp disintegration was delayed in the transgenic grains. Although the VPE4 gene and enzymatic activity was decreased in the early developing pericarp, storage capacity and the size of the endosperm and embryo were reduced in the mature VPE4-repressed grains. The persistence of the pericarp in the VPE4-affected grains constrains endosperm and embryo growth and leads to transcriptional reprogramming, perturbations in signalling and adjustments in metabolism. We conclude that VPE4 expression executes PCD in the pericarp, which is required for later endosperm filling, and argue for a role of PCD in maternal control of seed size in cereals.

Tribes and tribulations: interdisciplinary eHealth in providing services for people with a traumatic brain injury (TBI)

Background

eHealth has potential for supporting interdisciplinary care in contemporary traumatic brain injury (TBI) rehabilitation practice, yet little is known about whether this potential is being realised, or what needs to be done to further support its implementation. The purpose of this study was to explore health professionals’ experiences of, and attitudes towards eHealth technologies to support interdisciplinary practice within rehabilitation for people after TBI.

Methods

A qualitative study using narrative analysis was conducted. One individual interview and three focus groups were conducted with health professionals (n = 17) working in TBI rehabilitation in public and private healthcare settings across regional and metropolitan New South Wales, Australia.

Results

Narrative analysis revealed that participants held largely favourable views about eHealth and its potential to support interdisciplinary practice in TBI rehabilitation. However, participants encountered various issues related to (a) the design of, and access to electronic medical records, (b) technology, (c) eHealth implementation, and (d) information and communication technology processes that disconnected them from the work they needed to accomplish. In response, health professionals attempted to make the most of unsatisfactory eHealth systems and processes, but were still mostly unsuccessful in optimising the quality, efficiency, and client-centredness of their work.

Conclusions

Attention to sources of disconnection experienced by health professionals, specifically design of, and access to electronic health records, eHealth resourcing, and policies and procedures related to eHealth and interdisciplinary practice are required if the potential of eHealth for supporting interdisciplinary practice is to be realised.

Dose and dose rate extrapolation factors for malignant and non-malignant health endpoints after exposure to gamma and neutron radiation

Murine experiments were conducted at the JANUS reactor in Argonne National Laboratory from 1970 to 1992 to study the effect of acute and protracted radiation dose from gamma rays and fission neutron whole body exposure. The present study reports the reanalysis of the JANUS data on 36,718 mice, of which 16,973 mice were irradiated with neutrons, 13,638 were irradiated with gamma rays, and 6107 were controls. Mice were mostly Mus musculus, but one experiment used Peromyscus leucopus. For both types of radiation exposure, a Cox proportional hazards model was used, using age as timescale, and stratifying on sex and experiment. The optimal model was one with linear and quadratic terms in cumulative lagged dose, with adjustments to both linear and quadratic dose terms for low-dose rate irradiation (<5 mGy/h) and with adjustments to the dose for age at exposure and sex. After gamma ray exposure there is significant non-linearity (generally with upward curvature) for all tumours, lymphoreticular, respiratory, connective tissue and gastrointestinal tumours, also for all non-tumour, other non-tumour, non-malignant pulmonary and non-malignant renal diseases (p < 0.001). Associated with this the low-dose extrapolation factor, measuring the overestimation in low-dose risk resulting from linear extrapolation is significantly elevated for lymphoreticular tumours 1.16 (95% CI 1.06, 1.31), elevated also for a number of non-malignant endpoints, specifically all non-tumour diseases, 1.63 (95% CI 1.43, 2.00), non-malignant pulmonary disease, 1.70 (95% CI 1.17, 2.76) and other non-tumour diseases, 1.47 (95% CI 1.29, 1.82). However, for a rather larger group of malignant endpoints the low-dose extrapolation factor is significantly less than 1 (implying downward curvature), with central estimates generally ranging from 0.2 to 0.8, in particular for tumours of the respiratory system, vasculature, ovary, kidney/urinary bladder and testis. For neutron exposure most endpoints, malignant and non-malignant, show downward curvature in the dose response, and for most endpoints this is statistically significant (p < 0.05). Associated with this, the low-dose extrapolation factor associated with neutron exposure is generally statistically significantly less than 1 for most malignant and non-malignant endpoints, with central estimates mostly in the range 0.1-0.9. In contrast to the situation at higher dose rates, there are statistically non-significant decreases of risk per unit dose at gamma dose rates of less than or equal to 5 mGy/h for most malignant endpoints, and generally non-significant increases in risk per unit dose at gamma dose rates ≤5 mGy/h for most non-malignant endpoints. Associated with this, the dose-rate extrapolation factor, the ratio of high dose-rate to low dose-rate (≤5 mGy/h) gamma dose response slopes, for many tumour sites is in the range 1.2-2.3, albeit not statistically significantly elevated from 1, while for most non-malignant endpoints the gamma dose-rate extrapolation factor is less than 1, with most estimates in the range 0.2-0.8. After neutron exposure there are non-significant indications of lower risk per unit dose at dose rates ≤5 mGy/h compared to higher dose rates for most malignant endpoints, and for all tumours (p = 0.001), and respiratory tumours (p = 0.007) this reduction is conventionally statistically significant; for most non-malignant outcomes risks per unit dose non-significantly increase at lower dose rates. Associated with this, the neutron dose-rate extrapolation factor is less than 1 for most malignant and non-malignant endpoints, in many cases statistically significantly so, with central estimates mostly in the range 0.0-0.2.

Evaluation of Oxetan-3-ol, Thietan-3-ol, and Derivatives Thereof as Bioisosteres of the Carboxylic Acid Functional Group

The oxetane ring serves as an isostere of the carbonyl moiety, suggesting that oxetan-3-ol may be considered as a potential surrogate of the carboxylic acid functional group. To investigate this structural unit, as well as thietan-3-ol and the corresponding sulfoxide and sulfone derivatives, as potential carboxylic acid bioisosteres, a set of model compounds has been designed, synthesized, and evaluated for physicochemical properties. Similar derivatives of the cyclooxygenase inhibitor, ibuprofen, were also synthesized and evaluated for inhibition of eicosanoid biosynthesis in vitro. Collectively, the data suggest that oxetan-3-ol, thietan-3-ol, and related structures hold promise as isosteric replacements of the carboxylic acid moiety.

CYP3A genes and the association between prenatal methylmercury exposure and neurodevelopment

BACKGROUND

Results on the association between prenatal exposure to methylmercury (MeHg) and child neuropsychological development are heterogeneous. Underlying genetic differences across study populations could contribute to this varied response to MeHg. Studies in Drosophila have identified the cytochrome p450 3A (CYP3A) family as candidate MeHg susceptibility genes.

OBJECTIVES

We evaluated whether genetic variation in CYP3A genes influences the association between prenatal exposure to MeHg and child neuropsychological development.

METHODS

The study population included 2639 children from three birth cohort studies: two subcohorts in Seychelles (SCDS) (n=1160, 20 and 30months of age, studied during the years 2001-2012), two subcohorts from Spain (INMA) (n=625, 14months of age, 2003-2009), and two subcohorts from Italy and Greece (PHIME) (n=854, 18months of age, 2006-2011). Total mercury, as a surrogate of MeHg, was analyzed in maternal hair and/or cord blood samples. Neuropsychological development was evaluated using Bayley Scales of Infant Development (BSID). Three functional polymorphisms in the CYP3A family were analyzed: rs2257401 (CYP3A7), rs776746 (CYP3A5), and rs2740574 (CYP3A4).

RESULTS

There was no association between CYP3A polymorphisms and cord mercury concentrations. The scores for the BSID mental scale improved with increasing cord blood mercury concentrations for carriers of the most active alleles (β[95% CI]:=2.9[1.53,4.27] for CYP3A7 rs2257401 GG+GC, 2.51[1.04,3.98] for CYP3A5 rs776746 AA+AG and 2.31[0.12,4.50] for CYP3A4 rs2740574 GG+AG). This association was near the null for CYP3A7 CC, CYP3A5 GG and CYP3A4 AA genotypes. The interaction between the CYP3A genes and total mercury was significant (p<0.05) in European cohorts only.

CONCLUSIONS

Our results suggest that the polymorphisms in CYP3A genes may modify the response to dietary MeHg exposure during early life development.

Radiation-associated circulatory disease mortality in a pooled analysis of 77,275 patients from the Massachusetts and Canadian tuberculosis fluoroscopy cohorts

High-dose ionising radiation is associated with circulatory disease. Risks associated with lower-dose (<0.5 Gy) exposures remain unclear, with little information on risk modification by age at exposure, years since exposure or dose-rate. Tuberculosis patients in Canada and Massachusetts received multiple diagnostic x-ray fluoroscopic exposures, over a wide range of ages, many at doses <0.5 Gy. We evaluated risks of circulatory-disease mortality associated with <0.5 Gy radiation exposure in a pooled cohort of 63,707 patients in Canada and 13,568 patients in Massachusetts. Under 0.5 Gy there are increasing trends for all circulatory disease (n = 10,209; excess relative risk/Gy = 0.246; 95% CI 0.036, 0.469; p = 0.021) and for ischaemic heart disease (n = 6410; excess relative risk/Gy = 0.267; 95% CI 0.003, 0.552; p = 0.048). All circulatory-disease and ischaemic-heart-disease risk reduces with increasing time since exposure (p < 0.005). Over the entire dose range, there are negative mortality dose trends for all circulatory disease (p = 0.014) and ischaemic heart disease (p = 0.003), possibly due to competing causes of death over this dose interval.These results confirm and extend earlier findings and strengthen the evidence for circulatory-disease mortality radiation risk at doses <0.5 Gy. The limited information on well-known lifestyle/medical risk factors for circulatory disease implies that confounding of the dose trend cannot be entirely excluded.

Structure Property Relationships of Carboxylic Acid Isosteres

The replacement of a carboxylic acid with a surrogate structure, or (bio)-isostere, is a classical strategy in medicinal chemistry. The general underlying principle is that by maintaining the features of the carboxylic acid critical for biological activity, but appropriately modifying the physicochemical properties, improved analogs may result. In this context, a systematic assessment of the physicochemical properties of carboxylic acid isosteres would be desirable to enable more informed decisions of potential replacements to be used for analog design. Herein we report the structure–property relationships (SPR) of 35 phenylpropionic acid derivatives, in which the carboxylic acid moiety is replaced with a series of known isosteres. The data set generated provides an assessment of the relative impact on the physicochemical properties that these replacements may have compared to the carboxylic acid analog. As such, this study presents a framework for how to rationally apply isosteric replacements of the carboxylic acid functional group.