Pharyngeal Constrictor Dose-Volume Histogram Metrics and Patient-Reported Dysphagia in Head and Neck Radiotherapy

AIMS

Head and neck radiotherapy long-term survival continues to improve and the management of long-term side-effects is moving to the forefront of patient care. Dysphagia is associated with dose to the pharyngeal constrictors and can be measured using patient-reported outcomes to evaluate its effect on quality of life. The aim of the present study was to relate pharyngeal constrictor dose-volume parameters with patient-reported outcomes to identify prognostic dose constraints.

MATERIALS AND METHODS

A 64-patient training cohort and a 24-patient testing cohort of oropharynx and nasopharynx cancer patients treated with curative-intent chemoradiotherapy were retrospectively examined. These patients completed the MD Anderson Dysphagia Inventory outcome survey at 12 months post-radiotherapy to evaluate late dysphagia: a composite score lower than 60 indicated dysphagia. The pharyngeal constrictor muscles were subdivided into four substructures: superior, middle, inferior and cricopharyngeal. Dose-volume histogram (DVH) metrics for each of the structure combinations were extracted. A decision tree classifier was run for each DVH metric to identify dose constraints optimising the accuracy and sensitivity of the cohort. A 60% accuracy threshold and feature selection method were used to ensure statistically significant DVH metrics were identified. These dose constraints were then validated on the 24-patient testing cohort.

RESULTS

Existing literature dose constraints only had two dose constraints performing above 60% accuracy and sensitivity when evaluated on our training cohort. We identified two well-performing dose constraints: the pharyngeal constrictor muscle D63% < 55 Gy and the superior-middle pharyngeal constrictor combination structure V31Gy < 100%. Both dose constraints resulted in ≥73% mean accuracy and ≥80% mean sensitivity on the training and testing patient cohorts. In addition, a pharyngeal constrictor muscle mean dose <57 Gy resulted in a mean accuracy ≥74% and mean sensitivity ≥60%.

CONCLUSION

Mid-dose pharyngeal constrictor muscle and substructure combination dose constraints should be used in the treatment planning process to reduce late patient-reported dysphagia.

Erectile Dysfunction Pharmacotherapy Utilization after 60Gy in 20 Fractions Volumetric Modulated Arc Therapy to the Prostate

PURPOSE/OBJECTIVE(S)

To determine which factors predict for worsening erectile function after highly conformal, modestly hypofractionated radiotherapy to the prostate.

MATERIALS/METHODS

All patients who received 60Gy in 20 fractions, volumetric modulated arc therapy to the prostate across 4 centers over 9 years were included in this study. The provincial electronic medical record was interrogated to identify any new prescriptions for erectile dysfunction (ED) medication, any change in prescription of ED medication or any permanent discontinuance of ED medication persisting beyond 6 months post completion of any androgen deprivation therapy. The penile bulb, penile crux and penile shaft structures were retrospectively contoured. A Youden receiver-operator-curve analysis, logistic regression, and neural network based interpretable machine learning analysis were then used to determine dependencies between worsening ED and clinical factors including mean doses to these structures.

RESULTS

Two-hundred-twelve patients with median (inter-quartile-range) follow-up of 3.6 (3.2-4.4) years were identified. Median age was 72 (67-76) years. 104 (49%) patients received androgen deprivation therapy. Prior to treatment, 52 (25%) patients were on ED medication: 20 (9%) on sildenafil, 28 (13%) on tadalafil and 4 (8%) on vardenafil. Median PTV volume was 158.9 (129.8-192.1) cc. Median penile bulb, penile crux and penile shaft volumes were 4.7 (3.6-6.2) cc, 6.5 (5.1-8.5) cc and 93.3 (80.6-106.2) cc, respectively. PTV V95 was 99.8 (99.5-99.9)%. Mean doses to penile bulb, penile crux and penile shaft were 2094.8 (1306.2-3036.3) cGy, 2094.8 (1306.2-3036.3) cGy and 444.4 (313.2-650.5), respectively. Fifty-nine (28%) patients had a worsening of ED after treatment: 25 (12%) started a new ED medication, 6 (3%) had a prescription change and 28 (13%) stopped ED medication. On univariate analyses pretreatment use of ED medication predicted for worsening ED: odds ratio (OR) yes vs no: 10.2 (5.0 - 20.8; p<0.001). A trend towards mean dose to penile bulb [OR ≤2343.9 vs >2343.9: 1.7 (0.9-3.2; p = 0.08)] predicting for worsening ED was observed. Mean doses to penile crux [OR <1725.8 vs > 1725.8: 2.6 (1.3-5.2; p = 0.005)] and penile shaft [OR ≤344.9 vs >344.9: 5.2 (2.2-12.2; p<0.001)] predicted for worsening ED. Use of androgen deprivation therapy, and age at time of radiotherapy were not predictive of worsening ED. On multivariate analysis, only mean dose to penile shaft [OR ≤344.9 vs >344.9: 6.3 (1.9-20.3; p = 0.002)] and pretreatment use of ED medication [OR yes vs no: 11.1 (5.3-23.2; p<0.001)] predicted for worsening ED. A neural network analysis suggested that penile shaft mean dose and pre-treatment ED medication use are the most important factors in predicting worsening ED.

CONCLUSION

In this limited analysis, pre-treatment use of ED medication and mean dose to penile shaft predicted for worsening ED after treatment with modestly hypofractionated radiotherapy for prostate cancer.

Initial Experience with the Commercial Electron FLASH Research Extension

PURPOSE/OBJECTIVE(S)

The purpose of this study was to introduce a new commercial electron FLASH system that has the potential to become widely available for FLASH researchers globally. In this study, we first present the initial acceptance and commissioning tests for the FLASH system, and second, we highlight preliminary FLASH effect results from our cell studies.

MATERIALS/METHODS

A linear accelerator was converted into a commercial research platform with the FLASH Research Extension, enabling the generation of a powerful 16 MeV electron FLASH beam. The dosimetric and stability tests were conducted using various dosimeters (i.e., radiochromic film, optically stimulated luminescent dosimeters (OSLDs), and a plane-parallel ionization chamber). To evaluate the FLASH effect, normal and cancer cell lines were FLASH irradiated using different pulse repetition frequencies (PRF) of 18 pulses/s and 180 pulses/s.

RESULTS

The electron FLASH mode was able to generate over 1 Gy per pulse at the isocenter and a dose rate of up to 690 Gy/s near the accessory mount of the Linac gantry head. The charge collected by the plane-parallel ionization chamber at the highest PRF (i.e., 180 pulses/s) showed a linear relationship with the delivered number of pulses (i.e., 1 to 99 pulses) with a coefficient of determination (R2) of 0.9996. The absorbed dose measured using radiochromic film and OSLDs agreed within 3%, on average, and followed an inverse square law as the source-to-axis distance (SAD) varied for which the R2 values were 0.9972 and 0.9955 for radiochromic film and OSLDs, respectively. The profile of the FLASH beam was symmetrical but was not as flat as the conventional 16 MeV electron beam due to the use of a thinner custom scattering foil to reduce the degradation of the ultra-high dose rate. The depth-dose curve beyond the build-up region for the FLASH beam was similar to the conventional 16 MeV electron beam for which the range at 50% the maximum dose (R50) agreed within 0.5 mm. The FLASH beam output remained consistent over a 4-month period with a variation of 2.5%, on average. The FLASH sparing effect was observed in vitro for healthy human pancreatic cells. Furthermore, we observed that the highest PRF beam (180 pulses/s) was more effective at destroying pancreatic cancerous cells while minimizing damage to healthy cells compared to the lowest PRF beam (18 pulses/s).

CONCLUSION

The novel commercial FLASH Research Extension system was dosimetrically characterized for pre-clinical FLASH research, and preliminary in vitro results demonstrated the FLASH effect. Given the prevalence of linear accelerators, this new commercial system has the potential to greatly increase the access to FLASH research.

Commissioning and Initial Validation of Commercial Treatment Planning System for the Electron FLASH Research Extension

PURPOSE/OBJECTIVE(S)

The aim of this study was to investigate the feasibility of commissioning the 16 MeV electron FLASH beam in a commercial treatment planning system (TPS) for pre-clinical research purposes. The delivery system consisted of a new commercial solution for which a linear accelerator was modified into a FLASH Research Extension platform. Additionally, preliminary radiation biology results were highlighted to showcase the future use of this system.

MATERIALS/METHODS

To commission a commercial electron Monte Carlo (MC) for dose calculation of a 16 MeV FLASH beam in the TPS, radiochromic film was used to measure the vendor-required beam data, e.g., profiles and percent depth dose (PDD) curves for cone sizes of 6 × 6 cm2, 10 × 10 cm2, and 15 × 15 cm2 as well as an in-air profile for a 40 × 40 cm2 open field (no cone). Once the electron MC beam model was generated, additional measurements were collected for validation and compared against the calculated dose from the TPS. A treatment planning comparison between the newly commissioned FLASH beam and the conventional electron beam was conducted. Specifically, the dose-volume histograms (DVHs) for target volumes and organs at risk were investigated for skin cancer cases previously treated with conventional electron beams. Lastly, the FLASH dose distribution predicted by the electron MC for an in vitro cell study setup was validated with radiochromic film measurements, and initial radiobiology tests were conducted using FLASH and conventional dose-rate electron beams.

RESULTS

The electron MC calculated dose for the 16 MeV electron FLASH beam agreed with measured PDDs within 1% for all field sizes. The beam profile characteristics, such as penumbra, shape, and full width at half maximum, demonstrated good agreement with less than 0.5 mm difference between the TPS and measurements. There were noticeable differences in the profiles of large fields between the FLASH and conventional dose-rate beam models due to the more forward-peaked FLASH beam. For treatment planning, Regarding DVH, the FLASH dose-rate plan provided comparable plan quality to the conventional dose-rate plan, achieving adequate coverage for the target volumes and sparing the healthy organs and tissues. The electron MC dose prediction for the FLASH beam was also found to be in good agreement with the film measurements of the in vitro cell study setup. Furthermore, the FLASH beam was observed to be more effective with a 20 % increase in killing pancreatic cancer cells compared to the conventional dose rate.

CONCLUSION

The study successfully incorporated the 16 MeV electron FLASH Research Extension into the commercial TPS using electron Monte Carlo for dose calculation. This will be valuable for pre-clinical cell and animal studies. This research also enables FLASH treatment planning studies, a key component for the future implementation of FLASH into clinical care. Further research is necessary to incorporate the radiation biology effect of FLASH into the treatment planning system.

A human donor (cadaveric) observation study of three needle placements in the piriformis muscle

OBJECTIVE

To compare the safety and accuracy of three dry needling locations in the piriformis muscle using human donors.

DESIGN

Observational dissection study of embalmed human donors.

METHODS

A licensed physical therapist of 17 years clinical experience and 5 years teaching dry needling placed three needles in a medial, midpoint, and lateral location of 14 piriformis muscles of seven embalmed human donors. Block dissection allowed for observation of tissues the needles traversed and recording of the structures that the needles pierced.

RESULTS

The lateral needle pierced piriformis in 3/14 trials, and contacted sciatic nerve in 0/14 trials. The medial needle pierced both piriformis and sciatic nerve in 11/14 trials. The midpoint needle pierced the piriformis in 11/14 trials, and contacted sciatic nerve in 3/14 trials. Fisher's Exact test (p < 0.001) found a nonrandom association between dry needle placement, and dry needle contact.

CONCLUSIONS

When dry needling the piriformis, a lateral approach can avoid the sciatic nerve, but cannot accurately pierce the piriformis tendon. Furthermore, while a midpoint and medial approach finds the piriformis muscle with the same accuracy, the midpoint location avoided the sciatic nerve more often.

Technical note: Investigating the suitability of existing facilities for a new Lu-177 prostate-specific membrane antigen therapy program

BACKGROUND

¹⁷⁷ Lu prostate-specific membrane antigen (PSMA) therapy prolongs survival for some prostate cancer patients. To adopt this technique, institutions may need to evaluate the suitability of existing infrastructure.

PURPOSE

Develop a methodology to determine whether existing facilities can accommodate a ¹⁷⁷ Lu-PSMA therapy program.

METHODS

Room suitability is defined by both the ability to accommodate ¹⁷⁷ Lu-PSMA therapy workflow and to provide appropriate radiation shielding. Two methods of shielding calculation were performed: (1) National Council on Radiation Protection and Measurements report 151 (NCRP-151), with workload defined in terms of the activity of ¹⁷⁷ Lu administered, and (2) using the RadPro shielding calculator. This methodology was applied to ¹³¹ I therapy, PET-CT uptake, PET-SPECT injection, and orthovoltage therapy rooms.

RESULTS

¹³¹ I therapy rooms were found to meet both shielding and workflow requirements. The shielding was found to be adequate for orthovoltage and PET-SPECT facilities, neglecting patient transit between external washrooms. The workflow was the limiting factor for these rooms due to the requirement of dedicated washrooms that shield the patient and contain possible contamination. The PET-CT facility did not meet either criteria. The NCRP-151 method generally predicted a higher dose rate on the other side of shielding than did the RadPro calculator. The dose rate on the other side of concrete shielding as predicted by the NCRP-151 method increased relative to the dose rate predicted by the RadPro calculator as shielding thickness increased. For lead shielding, the dose rate predicted by the NCRP-151 method decreased relative to the result predicted by the RadPro calculator with increasing material thickness.

CONCLUSIONS

¹³¹ I therapy, PET-CT uptake, PET-SPECT injection, and orthovoltage therapy rooms were considered. The ¹³¹ I treatment rooms were the best candidate for ¹⁷⁷ Lu-PSMA therapy, due to their shielding and capability to accommodate the necessary workflow.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Angiographically Occult Subarachnoid Hemorrhage: Yield of Repeat Angiography, Influence of Initial CT Bleed Pattern, and Sources of Diagnostic Error in 242 Consecutive Patients

BACKGROUND AND PURPOSE

Nearly 20% of patients with spontaneous SAH have no definitive source on initial DSA. The purpose of this study was to investigate the timing and yield of repeat DSA, to clarify the influence of initial CT bleed pattern, and to characterize sources of diagnostic error in this scenario.

MATERIALS AND METHODS

We evaluated the yield of repeat DSA and clinical outcomes stratified by hemorrhage pattern on CT in consecutive patients with nontraumatic SAH with negative initial DSA findings at a referral center. Cases in which the culprit lesion was subsequently diagnosed were classified as physiologically occult (ie, undetectable) on the initial DSA, despite adequate technique and interpretation or misdiagnosed due to operator-dependent error.

RESULTS

Two hundred forty-two of 1163 (20.8%) patients with spontaneous SAH had negative initial DSA findings between 2009 and 2018. The SAH CT pattern was nonperimesencephalic (41%), perimesencephalic (36%), sulcal (18%), and CT-negative (5%). Repeat DSA in 135/242 patients (55.8%) revealed a source in 10 patients (7.4%): 4 saccular aneurysms, 4 atypical aneurysms, and 2 arteriovenous shunts. The overall yield of repeat DSA was 11.3% with nonperimesencephalic and 2.2% for perimesencephalic patterns. The yield of the second and third DSAs with a nonperimesencephalic pattern was 7.7% and 12%, respectively. Physiologically occult lesions accounted for 6/242 (2.5%) and operator-dependent errors accounted for 7/242 (2.9%) of all angiographically occult lesions on the first DSA.

CONCLUSIONS

Atypical aneurysms and small arteriovenous shunts are important causes of SAH negative on angiography. Improving DSAs technique can modestly reduce the need for repeat DSA; however, a small fraction of SAH sources remain occult despite adequate technique. These findings support the practice of repeating DSA in patients with a nonperimesencephalic SAH pattern.

P08 The quality of life and cost benefits of domiciliary 24-hour piperacillin/tazobactam 13.5 g infusion in patients with necrotizing otitis externa

Background

The incidence of necrotizing otitis externa (NOE) is increasing with the rise in the population who are elderly or immunocompromised. Currently there is no consensus on an antibiotic regimen for NOE but in a recent survey of otolaryngologists, 90% recommended using IV antibiotics.1,2 An initial 6 week period of IV antibiotics such as piperacillin/tazobactam has been recommended, this necessitated a prolonged hospital stay in patients who could be managed at home. To enable domiciliary treatment, a patient pathway was set-up, a ‘mid-line’ inserted and once clinically well (after 0–10 days in hospital) home antibiotic treatment was commenced.

Objectives

To evaluate the patient satisfaction, safety and cost benefit of using 6 weeks of domiciliary piperacillin/tazobactam 13.5 g administered with infusion pump in patients with NOE.

Methods

Since September 2017 to present, 11 patients (9 males, 2 females aged 52–91 years) received domiciliary IV antibiotics for NOE, patients completed a patient satisfaction questionnaire [Glasgow Benefit Inventory (GBI), a validated questionnaire that is used to assess the impact of any clinical intervention]. The cost of this service was compared with the traditional 6 week stay in hospital for IV antibiotic therapy. Patients were only asked to complete the GBI to evaluate a recognized treatment.

Results

The GBI scale ranges from −100 (maximal negative benefit) to 0 (no benefit), to +100 (maximal benefit). Table 1 demonstrates that domiciliary IV antibiotics have a positive impact on total and general health but the low scores for social and physical health reflect worsening of quality of life in patients with NOE. All patients expressed they preferred being at home rather than being in hospital. 6 weeks inpatient care (at £250 per night) equates to £10 500 per patient. Piperacillin/tazobactam 4.5 g injection, costing £7.85 per ampoule, given thrice daily for 6 weeks costs £989. Domiciliary treatment using piperacillin/tazobactam 13.5 g infusion device is £98.16 daily, 6 weeks antibiotic costs £4122 per patient. A domiciliary nurse visit is £120 equates to nursing costs of £5040 for antibiotic given by infusion. Domiciliary potentially saves £2327 per patient.

Conclusions

Although studies have assessed community IV antibiotic service;3 this study albeit with limited patient numbers is the first evaluating patient satisfaction and cost benefit of domiciliary antibiotics in patients with NOE. All patients preferred to be treated at home with no safety issues raised. There is a potential saving of £2347 per patient with domiciliary rather than in-patient treatment as well as ‘freeing-up’ beds for other patients requiring admission.

Differences in obstetrical care and outcomes associated with the proportion of the obstetrician's shift completed

BACKGROUND

Understanding and improving obstetrical quality and safety is an important goal of professional societies, and many interventions such as checklists, safety bundles, educational interventions, or other culture changes have been implemented to improve the quality of care provided to obstetrical patients. Although many factors contribute to delivery decisions, a reduced workload has addressed how provider issues such as fatigue or behaviors surrounding impending shift changes may influence the delivery mode and outcomes.

OBJECTIVE

The objective was to assess whether intrapartum obstetrical interventions and adverse outcomes differ based on the temporal proximity of the delivery to the attending's shift change.

STUDY DESIGN

This was a secondary analysis from a multicenter obstetrical cohort in which all patients with cephalic, singleton gestations who attempted vaginal birth were eligible for inclusion. The primary exposure used to quantify the relationship between the proximity of the provider to their shift change and a delivery intervention was the ratio of time from the most recent attending shift change to vaginal delivery or decision for cesarean delivery to the total length of the shift. Ratios were used to represent the proportion of time completed in the shift by normalizing for varying shift lengths. A sensitivity analysis restricted to patients who were delivered by physicians working 12-hour shifts was performed. Outcomes chosen included cesarean delivery, episiotomy, third- or fourth-degree perineal laceration, 5-minute Apgar score of <4, and neonatal intensive care unit admission. Chi-squared tests were used to evaluate outcomes based on the proportion of the attending's shift completed. Adjusted and unadjusted logistic models fitting a cubic spline (when indicated) were used to determine whether the frequency of outcomes throughout the shift occurred in a statistically significant, nonlinear pattern RESULTS: Of the 82,851 patients eligible for inclusion, 47,262 (57%) had ratio data available and constituted the analyzable sample. Deliveries were evenly distributed throughout shifts, with 50.6% taking place in the first half of shifts. There were no statistically significant differences in the frequency of cesarean delivery, episiotomy, third- or fourth-degree perineal lacerations, or 5-minute Apgar scores of <4 based on the proportion of the shift completed. The findings were unchanged when evaluated with a cubic spline in unadjusted and adjusted logistic models. Sensitivity analyses performed on the 22.2% of patients who were delivered by a physician completing a 12-hour shift showed similar findings. There was a small increase in the frequency of neonatal intensive care unit admissions with a greater proportion of the shift completed (adjusted P=.009), but the findings did not persist in the sensitivity analysis.

CONCLUSION

Clinically significant differences in obstetrical interventions and outcomes do not seem to exist based on the temporal proximity to the attending physician's shift change. Future work should attempt to directly study unit culture and provider fatigue to further investigate opportunities to improve obstetrical quality of care, and additional studies are needed to corroborate these findings in community settings.

Residue analytical method for the determination of trifluoroacetic acid and difluoroacetic acid in plant matrices by capillary electrophoresis tandem mass spectrometry (CE-MS/MS)

In the past years, the technology for trace residue analysis of plant protection compounds in plant and animal matrices, soil, and water has gradually changed to meet changing regulatory demands. Generally, from the '70s to the '90s of the last century, the active compounds and only a few major metabolites had to be determined in a typical "residue definition". Step by step and within the framework of product safety assessments of the enforcement of residues in dietary matrices and in the environment, further metabolites have come into the authorities focus. Many active substances were formerly determined via gas chromatography (GC) based detection techniques. The introduction of liquid chromatography tandem mass spectrometry (LC-MS/MS) technology in the '90s and the acceptance of this technique, by official bodies at the end of the '90s, has led to a major change for residue analytical laboratories all over the world. Most of the medium to non-polar active compounds as well as many of the more polar metabolites can be detected with this technique, and today LC-MS/MS is the "workhorse" in many residue analytical laboratories in the industry as well as official enforcement labs responsible for analyzing registration-related field studies. With the demand to analyze further breakdown products, more and more polar compounds, or even (permanently) charged target compounds, have now come into the focus of the registration authorities. This now brings standard LC-based techniques to their limits and requires the application of approaches such as hydrophilic interaction chromatography (HILIC) MS/MS or ion chromatography, however these techniques often incur related uncertainties and problems with matrix samples. The aim of this study was to develop a new CE-MS/MS-based approach to reduce the impact of matrix on the separation and detection of trifluoroacetic acid (TFA) and difluoroacetic acid (DFA) in agrochemical field trials. This project used 7 representative examples of fruit, grain and vegetables which had undergone homogenization and extraction with acetonitrile water and filtration before CE-MS/MS analysis. The CE-MS/MS developed reached the limit of quantitation (LOQ) requirement of current legislation for both TFA and DFA (0.01 mg/kg) in all 7 matrices tested. The mean relative standard deviation (RSD) obtained from the repeat analysis of control field trail samples in all matrices, for both TFA and DFA, was less than 10% meeting GLP guidelines. When compared with LC-MS/MS, using on column loading amounts, the CE-MS/MS was 17 - 43 times more sensitive than a standard method and less matrix effects were observed. The developed method was validated under GLP conditions to provide a GLP-validated residue analytical method for the charged metabolites TFA and DFA in matrix samples from GLP field residue trials.

SAT0143 A PHASE 1 STUDY IN HEALTHY VOLUNTEERS EXPLORING THE SAFETY, PHARMACOKINETICS AND PHARMACODYNAMICS OF ATI-450: A NOVEL ORAL MK2 INHIBITOR

Background:

ATI-450, is an investigational small molecule inhibitor of the MAPK-activated protein kinase 2 (MK2) signaling pathway. This pathway drives the expression of multiple cytokines including TNFα, IL-1α and β, and IL-6.

Objectives:

We evaluated the safety and tolerability of ATI-450 in healthy volunteers as well as pharmacokinetics (PK) and pharmacodynamics (PD). Here we present data from single and multiple ascending dose cohorts. The aim was to select a dose for evaluation in phase 2 in patients with rheumatoid arthritis.

Methods:

Safety, PK and PD were assessed in a randomized, observer-blind, placebo-controlled, phase 1 study in male and female healthy subjects aged 18-55 (n=77).

Safety and tolerability of ATI-450 was evaluated based on adverse events, clinical laboratory, vital signs, 12-lead ECG, Holter monitoring, and physical examination. Blood was drawn for PK analysis at 0.5, 1, 2, 4, 6, 8, 12 hours, 24, 36, and 48 hours post dose in the SAD cohort and on day 7 of the MAD cohort. PD of ATI-450 were explored by investigating the inhibition of a target biomarker, phospho-HSP27 (pHSP27) and proinflammatory cytokines, TNFα, IL1β, IL6 and IL8 inex-vivoLPS-stimulated blood samples collected 4 and 12 hours post dose on day 7 from subjects in the MAD cohorts.

Results:

ATI-450 was generally well tolerated. No serious adverse events or severe adverse events were reported, and no adverse events led to discontinuation of the study medication. The most common adverse events (reported by 2 or more subjects who received ATI-450) observed during the trial were dizziness, headache, upper respiratory tract infection, constipation, nausea, and abdominal pain. All adverse events were mild. A trend of a decrease in absolute neutrophil count (ANC) was observed without correlated clinical sequelae.

ATI-450 had dose proportional PK with a terminal half-life (t½) of 9-12 hours in the MAD cohort on day 7. A dose and concentration dependent inhibition ofex vivostimulated cytokines and target biomarker was observed. On day 7, patients in the 50mg BID dose (the dose with the highest degree of inhibition) recorded mean trough drug levels (12 hours post dose) that were 1.4, 2.5, 2.5 and 2.4 times greater than the IC80for TNFα, IL1β, IL8 and pHSP27 respectively. Mean Cmax drug levels (4 hours post dose) were 3.6, 6.4, 6.2 and 6.0 times greater than the IC80for TNFα, IL1β, IL8 and pHSP27 respectively. IL6 levels were inhibited by more than 50% for part of the dosing interval.

Conclusion:

Oral ATI-450 was generally well tolerated at all doses with dose proportional PK. The t½ suggests that once or twice daily oral dosing may be possible. At the 50mg BID dose, marked inhibition of TNFα, IL1β and IL8, IL6 and pHSP27 was observed. ATI-450 has the potential to be an oral, small molecule drug which can target multiple cytokines. Exploration of its benefit to risk profile in patients with rheumatoid arthritis is warranted.

Disclosure of Interests:

Judy Schnyder Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Joe Monahan Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Walter Smith Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Heidi Hope Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, Deborah Kelly Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, David Burt Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, E Huff Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, A Kaul Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, A Hildebrand Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, B Burnette Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, N Klug Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics, M Bangs Shareholder of: Aclaris Therapeutics, Employee of: Aclaris Therapeutics, David Gordon Shareholder of: aclaris therapeutics, Employee of: aclaris therapeutics

Liquid Chromatographic Determination of Major Organic Acids in Apple Juice and Cranberry Juice Cocktail: Collaborative Study

Twelve laboratories collaboratively studied a liquid chromatographic method for determination of quinic, malic, and citric acids in cranberry juice cocktail and apple juice. Samples are passed through a disposable silica cartridge, filtered, and directly injected into the chromatograph. The mobile phase is 0.2M KH2PO4 (pH 2.4). Two reverse phase columns are used, with UV detection at 214 nm. Six samples of cranberry juice cocktail and 6 samples of apple juice were sent to each collaborator. Repeatability and reproducibility coefficients of variation ranged from 1.2 to 7.6% and from 2.9 to 14.7%, respectively, for quinic, malic, and citric acid levels above 0.10%. The precision of the method is satisfactory. The method has been adopted official first action.

Determination of Zearalenone in Barley, Maize and Wheat Flour, Polenta, and Maize-Based Baby Food by Immunoaffinity Column Cleanup with Liquid Chromatography: Interlaboratory Study

An interlaboratory study was performed on behalf of the UK Food Standards Agency to evaluate the effectiveness of an affinity column cleanup liquid chromatography (LC) method for the determination of zearalenone (ZON) in a variety of cereals and cereal products at proposed European regulatory limits. The test portion is extracted with acetonitrile:water. The sample extract is filtered, diluted, and applied to an affinity column. The column is washed, and ZON is eluted with acetonitrile. ZON is quantified by reversed-phase LC with fluorescence detection. Barley, wheat and maize flours, polenta, and a maize-based baby food naturally contaminated, spiked, and blank (very low level) were sent to 28 collaborators in 9 European countries and 1 collaborator in New Zealand. Participants were asked to spike test portions of all samples at a ZON concentration equivalent to 100 μg/kg. Average recoveries ranged from 91–111%. Based on results for 4 artificially contaminated samples (blind duplicates) and 1 naturally contaminated sample (blind duplicate), the relative standard deviation for repeatability (RSDr) ranged from 6.9–35.8%, and the relative standard deviation for reproducibility (RSDR) ranged from 16.4–38.2%. The method showed acceptable within- and between-laboratory precision for all 5 matrixes, as evidenced by HorRat values &lt;1.7.

Dental Public Health in Action: Understanding oral health care needs and oral health-related quality of life in vulnerable adults in Plymouth

This paper aims to provide a snapshot analysis of the oral health status of vulnerable adults in Plymouth; and to demonstrate the extent to which oral disease impacts on their normal functioning through the implementation of the Oral Health Impact Profile (OHIP). It is acknowledged that gaining a representative sample of a transient population such as people who are homeless, or individuals affected by problematic use of drugs and/or alcohol is difficult. An opportunity was identified to collect data within the Community Engagement Team's (CET) programme of activity within the Peninsula Dental Social Enterprise. The CET works alongside local organisations to enable dental students from Peninsula School of Dentistry to undertake outreach programmes in a variety of settings. A study was designed which aimed to analyse the oral health status of vulnerable adults accessing three day-support services in Plymouth, and to understand the extent to which oral disease impacts on their normal functioning through the OHIP-14. For all impact domains, the 44 patients in this study reported a greater impact than that found in the Adult Dental Health Survey. The most commonly reported impact domains were physical pain and psychological discomfort. The sample was divided into high and low oral health-related quality of life impact groups, and those participants in the high impact group had significantly greater median D₃MFT scores, i.e. higher levels of decay experience. This survey highlights how these vulnerable groups are characterised by a high prevalence of poor oral health, ill-health, deprivation and social exclusion.

MR Venous Flow in Sigmoid Sinus Diverticulum

BACKGROUND AND PURPOSE

Case reports demonstrate that coiling of a sigmoid sinus diverticulum can treat pulsatile tinnitus. We hypothesized that MR imaging 4D flow and computational fluid dynamics would reveal distinct blood flow patterns in the venous outflow tract in these patients.

MATERIALS AND METHODS

Patients with pulsatile tinnitus of suspected venous etiology underwent MR imaging at 3T, using venous phase contrast-enhanced MR angiography, 4D flow, and 2D phase contrast. The contrast-enhanced MRA contours were evaluated to determine the presence and extent of a sigmoid sinus diverticulum. Computational fluid dynamics analysis was performed using the 4D flow inlet flow and the luminal contours from contrast-enhanced MRA as boundary conditions. In addition, computational fluid dynamics was performed for the expected post treatment conditions by smoothing the venous geometry to exclude the sigmoid sinus diverticulum from the anatomic boundary conditions. Streamlines were generated from the 4D flow and computational fluid dynamics velocity maps, and flow patterns were examined for the presence of rotational components.

RESULTS

Twenty-five patients with pulsatile tinnitus of suspected venous etiology and 10 control subjects were enrolled. Five (20%) of the symptomatic subjects had sigmoid sinus diverticula, all associated with an upstream stenosis. In each of these patients, but none of the controls, a stenosis-related flow jet was directed toward the opening of the sigmoid sinus diverticulum with rotational flow patterns in the sigmoid sinus diverticulum and parent sigmoid sinus on both 4D flow and computational fluid dynamics.

CONCLUSIONS

Consistent patterns of blood flow can be visualized in a sigmoid sinus diverticulum and the parent sinus using 4D flow and computational fluid dynamics. Strong components of rotational blood flow were seen in subjects with sigmoid sinus diverticula that were absent in controls.

Neonatal outcomes of elective early-term births after demonstrated fetal lung maturity

BACKGROUND

Studies of early-term birth after demonstrated fetal lung maturity show that respiratory and other outcomes are worse with early-term birth (37⁰-38⁶ weeks) even after demonstrated fetal lung maturity when compared with full-term birth (39⁰-40⁶ weeks). However, these studies included medically indicated births and are therefore potentially limited by confounding by the indication for delivery. Thus, the increase in adverse outcomes might be due to the indication for early-term birth rather than the early-term birth itself.

OBJECTIVE

We examined the prevalence and risks of adverse neonatal outcomes associated with early-term birth after confirmed fetal lung maturity as compared with full-term birth in the absence of indications for early delivery.

STUDY DESIGN

This is a secondary analysis of an observational study of births to 115,502 women in 25 hospitals in the United States from 2008 through 2011. Singleton nonanomalous births at 37-40 weeks with no identifiable indication for delivery were included; early-term births after positive fetal lung maturity testing were compared with full-term births. The primary outcome was a composite of death, ventilator for ≥2 days, continuous positive airway pressure, proven sepsis, pneumonia or meningitis, treated hypoglycemia, hyperbilirubinemia (phototherapy), and 5-minute Apgar <7. Logistic regression and propensity score matching (both 1:1 and 1:2) were used.

RESULTS

In all, 48,137 births met inclusion criteria; the prevalence of fetal lung maturity testing in the absence of medical or obstetric indications for early delivery was 0.52% (n = 249). There were 180 (0.37%) early-term births after confirmed pulmonary maturity and 47,957 full-term births. Women in the former group were more likely to be non-Hispanic white, smoke, have received antenatal steroids, have induction, and have a cesarean. Risks of the composite (16.1% vs 5.4%; adjusted odds ratio, 3.2; 95% confidence interval, 2.1-4.8 from logistic regression) were more frequent with elective early-term birth. Propensity scores matching confirmed the increased primary composite in elective early-term births: adjusted odds ratios, 4.3 (95% confidence interval, 1.8-10.5) for 1:1 and 3.5 (95% confidence interval, 1.8-6.5) for 1:2 matching. Among components of the primary outcome, CPAP use and hyperbilirubinemia requiring phototherapy were significantly increased. Transient tachypnea of the newborn, neonatal intensive care unit admission, and prolonged neonatal intensive care unit stay (>2 days) were also increased with early-term birth.

CONCLUSION

Even with confirmed pulmonary maturity, early-term birth in the absence of medical or obstetric indications is associated with worse neonatal respiratory and hepatic outcomes compared with full-term birth, suggesting relative immaturity of these organ systems in early-term births.

Greenhouse gas and ammonia emissions from production of compost bedding on a dairy farm

Recent developments in composting technology enable dairy farms to produce their own bedding from composted manure. This management practice alters the fate of carbon and nitrogen; however, there is little data available documenting how gaseous emissions are impacted. This study measured in-situ emissions of methane (CH₄), carbon dioxide (CO₂), nitrous oxide (N₂O), and ammonia (NH₃) from an on-farm solid-liquid separation system followed by continuously-turned plug-flow composting over three seasons. Emissions were measured separately from the continuously-turned compost phase, and the compost-storage phase prior to the compost being used for cattle bedding. Active composting had low emissions of N₂O and CH₄ with most carbon being emitted as CO₂-C and most N emitted as NH₃-N. Compost storage had higher CH₄ and N₂O emissions than the active phase, while NH₃ was emitted at a lower rate, and CO₂ was similar. Overall, combining both the active composting and storage phases, the mean total emissions were 3.9×10^-2gCH₄kg^-1 raw manure (RM), 11.3gCO₂kg^-1 RM, 2.5×10^-4g N₂O kg^-1 RM, and 0.13g NH₃ kg^-1 RM. Emissions with solid-separation and composting were compared to calculated emissions for a traditional (unseparated) liquid manure storage tank. The total greenhouse gas emissions (CH₄+N₂O) from solid separation, composting, compost storage, and separated liquid storage were reduced substantially on a CO₂-equivalent basis compared to traditional liquid storage. Solid-liquid separation and well-managed composting could mitigate overall greenhouse gas emissions; however, an environmental trade off was that NH₃ was emitted at higher rates from the continuously turned composter than reported values for traditional storage.

The revolving door: antibiotic allergy labelling in a tertiary care centre

BACKGROUND

Patients frequently report antibiotic allergies; however, only 10% of labelled patients have a true allergy.

AIM

We investigated the documentation of antibiotic 'allergy' labels (AAL) and the effect of labelling on clinical outcomes, in a West Australian adult tertiary hospital.

METHODS

Retrospective cross-sectional analysis of patients captured in the 2013 and 2014 National Antimicrobial Prescribing Surveys was carried out. Data were collected on documented antibiotic adverse drug reactions, antibiotic cost, prescribing appropriateness, prevalence of multi-drug resistant organisms, length of stay, intensive care admission and readmissions.

RESULTS

Of the 687 patients surveyed, 278 (40%) were aged 70 or above, 365 (53%) were male and 279 (41%) were prescribed antibiotics. AAL were recorded in 122 (18%) patients and the majority were penicillin labels (n = 87; 71%). Details of AAL were documented for 80 of 141 (57%) individual allergy labels, with 61 describing allergic symptoms. Patients with beta-lactam allergy labels received fewer penicillins (P = 0.0002) and more aminoglycosides (P = 0.043) and metronidazole (P = 0.021) than patients without beta-lactam labels. Five patients received an antibiotic that was contraindicated according to their allergy status. Patients with AAL had significantly more hospital readmissions within 4 weeks (P = 0.001) and 6 months (P = 0.025) of discharge, compared with unlabelled patients. The majority (81%) of readmitted labelled patients had major infections.

CONCLUSIONS

AAL are common, but poorly documented in hospital records. Patients with AAL are significantly more likely to require alternative antibiotics and hospital readmissions. There may be a role for antibiotic allergy delabelling to mitigate the clinical and economic burdens for patients with invalid allergy labels.

Asymmetric dimethylarginine and symmetric dimethylarginine prospectively relates to carotid wall thickening in black men: the SABPA study

The relationship of both asymmetric (ADMA) and symmetric (SDMA) dimethylarginine with carotid wall thickness is inconclusive especially among black populations. We aimed to compare carotid intima media thickness (cIMT) and dimethylarginine levels in 75 black and 91 white men at baseline and after a 3-year follow-up, and to investigate associations of percentage change in cIMT with percentage change in dimethylarginine levels (ADMA and SDMA). Plasma levels of ADMA and SDMA were determined with a liquid chromatography mass spectrometry method and B-mode ultrasonography was used to determine the cIMT at baseline and follow-up. In black men, mean cIMT (p = 0.79) and ADMA levels (p = 0.67) remained the same, but SDMA levels were lower (p < 0.001) when comparing baseline and follow-up. In white men, cIMT increased (p < 0.001), but both mean ADMA and SDMA levels decreased (p < 0.001) over time. In black men, percentage change in cIMT was positively associated with percentage change in ADMA (R ² = 0.49; β = 0.46; p < 0.001) and percentage change in SDMA (R ² = 0.46; β = 0.41; p < 0.001). These associations were absent in the white men. Despite lower mean SDMA and similar ADMA and cIMT in black men, percentage change in cIMT was independently associated with percentage change in ADMA and percentage change in SDMA. These results suggest an important role for ADMA and SDMA lowering strategies to delay carotid wall thickening, especially in black populations prone to the development of cardiovascular disease.

Communities in action: developing a dental ambassador training programme for adults with learning disability

Adults with learning disabilities may be at higher risk of poor oral health. The community outreach programme attached to Plymouth University Peninsula Dental School used established links with local agencies for this group to try out an intervention using service users as dental ambassadors. A programme was developed to meet the needs of the group and training in oral health key messages was provided along with support in presentation skills. Early evaluation shows promise in terms of feasibility, interest and improved self-care. Public health competencies being illustrated: Strategic leadership, communication, teaching and training, and collaborative working for health and oral health improvement.

Recent advances in understanding hypertension development in sub-Saharan Africa

Consistent reports indicate that hypertension is a particularly common finding in black populations. Hypertension occurs at younger ages and is often more severe in terms of blood pressure levels and organ damage than in whites, resulting in a higher incidence of cardiovascular disease and mortality. This review provides an outline of recent advances in the pathophysiological understanding of blood pressure elevation and the consequences thereof in black populations in Africa. This is set against the backdrop of populations undergoing demanding and rapid demographic transition, where infection with the human immunodeficiency virus predominates, and where under and over-nutrition coexist. Collectively, recent findings from Africa illustrate an increased lifetime risk to hypertension from foetal life onwards. From young ages black populations display early endothelial dysfunction, increased vascular tone and reactivity, microvascular structural adaptions as well as increased aortic stiffness resulting in elevated central and brachial blood pressures during the day and night, when compared to whites. Together with knowledge on the contributions of sympathetic activation and abnormal renal sodium handling, these pathophysiological adaptations result in subclinical and clinical organ damage at younger ages. This overall enhanced understanding on the determinants of blood pressure elevation in blacks encourages (a) novel approaches to assess and manage hypertension in Africa better, (b) further scientific discovery to develop more effective prevention and treatment strategies and

Abstract P4-06-01: Patient derived DCIS mouse-intraductal (MIND) models recapitulate the full spectrum of human patient pathology and histologic features including progression to invasion in a subset of cases

Introduction: The 20-year breast cancer mortality rate following a DCIS diagnosis is ∼3%. Radiation and anti-hormonal therapy of DCIS has not resulted in improved overall survival, which argues against the non-selective use of such therapies in DCIS management. However, some DCIS cases do progress to invasive cancer, and these patients may benefit from treatment. A study of 80 DCIS patients followed for up to 30 years reported a 43% progression rate. Notably, progression was not predicted by grade, as 39% of even low-grade DCIS ultimately progressed to invasive cancer. Clearly, there is a need to identify which DCIS lesions are likely to progress. We have developed a novel mouse xenograft model (mouse-intraductal; MIND) to study the molecular basis of DCIS progression and enable identification of suitable biomarkers that predict invasive progression.

Methods: MIND involves injection of epithelial cells derived from patient breast lesions into the mammary ducts of immunocompromised mice. Serial sections of mouse mammary glands containing DCIS xenograft lesions were examined at time intervals of 3-14 months post-engraftment by histology using hematoxylin and eosin (H&E) and immunohistochemistry using anti-human cytokeratin 5/19, smooth muscle actin, ER, PR, p53, Ki67 and HER-2.

Results: Intraductal injection of cells derived from breast lesions of 28 patients into 133 mice resulted in a successful engraftment rate of 60%. Among these, 12 pure DCIS samples were injected into 35 different mice to create MIND xenografts. As early as three months post-engraftment, the DCIS xenograft cells showed multilayered in situ growth consisting of atypical neoplastic cells with prominent and vesicular nuclei. DCIS MIND xenografts exhibited the full spectrum of human DCIS histologic features, including similar biomarker expression (ER, PR, Ki67, HER-2 and p53) at long-term follow-up after engraftment (up to 12 months). Most remarkably, a subset of xenografts representing 5 patients (5/12; 42%) showed progression to invasion 6-12 months post-engraftment in the absence of any external genetic manipulations. This rate is very similar to that reported for human DCIS progression in untreated patients. MIND DCIS xenograft lesions that progressed showed disruption of basement membrane and myoepithelial layer by the invasive cells, retraction of basement membrane, and micro-invasion. MIND DCIS lesions were enriched in small capillaries, and in some cases clusters of invasive cells appeared inside nearby blood vessels.

Conclusion: The MIND xenograft is a viable model for human DCIS progression that recapitulates histologic features of human DCIS, as well as reported rates of progression to invasion. The availability of this innovative model provides a valuable tool for the discovery of new biomarkers to identify DCIS with invasive potential. The identification of high risk DCIS will ultimately help patients and clinicians choose the best course of therapy and avoid the morbidity and costs associated with unnecessary treatment.

Citation Format: Behbod F, Limback D, Hong Y, Elsarraj H, Berger J, Heddens E, Valdez K, Smith WP, Inciardi M, Reddick M, Gatewood J, Darrah J, Winblad O, Meierotto R, Ricci L, Wagner J, Amin A, May L, Cusick T, Mammen J, Fields T, Godwin AK, Fabian C, Kaufman C, Tawfik O, Fan F. Patient derived DCIS mouse-intraductal (MIND) models recapitulate the full spectrum of human patient pathology and histologic features including progression to invasion in a subset of cases [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-06-01.

Sensitivity of soil organic carbon to grazing management in the semi-arid rangelands of south-eastern Australia

This study compared the effects of grazing management on soil organic carbon (OC) stocks in the semi-arid rangelands of New South Wales, Australia. A field survey was conducted at three locations (Brewarrina, Cobar–North and Cobar–South), with paired sites of long-term (>8 years) rotational grazing management and continuously grazed pastures (either set stocked or no stocking). At each location, soil OC, carbon (C) fractions, soil nitrogen (N) and microsite and site factors (including ground cover and woody vegetation) were measured. The control of total grazing pressure (TGP) through rotational grazing and exclusion fencing did not increase soil C stocks compared with continuous grazing for the majority of comparisons. However, in some parts of the landscape, higher soil C stock was found with TGP control, for example on the ridges (21.6 vs 13.3 t C ha–1 to 0.3 m). C stocks increased with litter and perennial ground cover and with close proximity to trees. At Brewarrina, C stocks were positively affected by perennial plant cover (P < 0.001) and litter (P < 0.05), whereas at Cobar–North and Cobar–South C stocks were positively affected by the presence of trees (P < 0.001), with higher C stocks in close proximity to trees, and with increasing litter cover (P < 0.01). The present study demonstrates that natural resource benefits, such as increased perennial cover, can be achieved through controlling TGP in the rangelands but increases in soil C may be limited in certain parts of the landscape. These findings also highlight that interactions between managed and unmanaged TGP and microsite factors, such as ground cover and proximity to woody vegetation, need to be considered when evaluating the role of changed grazing management on soil C.

Cardiac Troponin T as Early Marker of Subclinical Cardiovascular Deterioration in Black Hypertensive Women

BACKGROUND

Hypertensive heart disease is a rising concern, especially among black South African women. As high sensitivity cardiac troponin T (cTnT) is a marker of cardiomyocyte damage, we determined the potential link of (i) systemic endothelial dysfunction (reflected by urinary albumin-to-creatinine ratio), (ii) large artery stiffness, (iii) cardiac volume load (estimated by the N-terminal prohormone B-type natriuretic peptide (Nt-proBNP)), and (iv) ECG left ventricular hypertrophy in post-menopausal black women.

METHODS

In 121 (50 normotensive and 71 hypertensive) black women (mean age: 60.6 years), basic cardiovascular assessments including blood pressure and ECG were performed, along with plasma and urinary biomarkers including cTnT.

RESULTS

The cTnT levels (p=0.049) along with Nt-proBNP (p=0.003), pulse pressure (p<0.0001) and the Cornell product (p=0.030) were higher in hypertensive than normotensive women. Only in hypertensive women, was cTnT independently associated with urinary albumin-to-creatinine ratio (β=0.25; p=0.019), pulse pressure (β=0.31; p=0.019), Nt-proBNP (β=0.47; p<0.0001) and Cornell product (β=0.31; p=0.018). An independent association between albumin-to-creatinine ratio and cTnT was also evident in normotensive women (β=0.34; p=0.037).

CONCLUSION

We found cTnT to be a useful marker in an elderly black population relating to several measures of cardiovascular deterioration - from subclinical endothelial dysfunction to left ventricular hypertrophy.

GS-9857 in patients with chronic hepatitis C virus genotype 1-4 infection: a randomized, double-blind, dose-ranging phase 1 study

GS-9857, an inhibitor of the hepatitis C virus (HCV) nonstructural protein (NS) 3/4A, demonstrates potent activity against HCV genotypes 1-6 and improved coverage against commonly encountered NS3 resistance-associated variants (RAVs). In this study, the safety, tolerability, antiviral activity and pharmacokinetics (PK) of GS-9857 were evaluated in patients with chronic HCV genotype 1-4 infection. Patients with genotype 1-4 infection received placebo or once-daily GS-9857 at doses ranging from 50 to 300 mg for 3 days under fasting conditions. GS-9857 was well tolerated; all reported adverse events (AEs) were mild or moderate in severity. Diarrhoea and headache were the most commonly reported AEs. Grade 3 or 4 laboratory abnormalities were observed in 17% of patients receiving GS-9857; there were no Grade 3 or 4 abnormalities in alanine aminotransferase, aspartate aminotransferase or alkaline phosphatase levels. GS-9857 demonstrated potent antiviral activity in patients with chronic HCV infection, achieving mean and median maximum reductions in HCV RNA of ≥3 log10 IU/mL following administration of a 100-mg dose in patients with HCV genotype 1a, 1b, 2, 3 or 4 infection. The antiviral activity of GS-9857 was unaffected by the presence of pretreatment NS3 RAVs. In patients with genotype 1-4 infection, GS-9857 exhibited linear PK and was associated with a median half-life of 29-42 h, supporting once-daily dosing. Thus, the tolerability, efficacy and pharmacokinetic profile of GS-9857 support its further evaluation for treatment of patients with chronic HCV infection.

Diffusion out of a triangle

A problem in molecular genetics called for the following result. If a particle is dropped at random on a right-angled isosceles triangle, and thus allowed to execute symmetrical Brownian motion, the chance that it will first leave the triangle via the hypotenuse is 0.41062. An inequality and two methods of deriving this probability are illustrated. The most useful source of solutions to diffusion problems of this kind is the torsion problem of elasticity.

Preterm neonatal morbidity and mortality by gestational age: a contemporary cohort

BACKGROUND

Although preterm birth <37 weeks' gestation is the leading cause of neonatal morbidity and mortality in the United States, the majority of data regarding preterm neonatal outcomes come from older studies, and many reports have been limited to only very preterm neonates. Delineation of neonatal outcomes by delivery gestational age is needed to further clarify the continuum of mortality and morbidity frequencies among preterm neonates.

OBJECTIVE

We sought to describe the contemporary frequencies of neonatal death, neonatal morbidities, and neonatal length of stay across the spectrum of preterm gestational ages.

STUDY DESIGN

This was a secondary analysis of an obstetric cohort of 115,502 women and their neonates who were born in 25 hospitals nationwide, 2008 through 2011. All liveborn nonanomalous singleton preterm (23.0-36.9 weeks of gestation) neonates were included in this analysis. The frequency of neonatal death, major neonatal morbidity (intraventricular hemorrhage grade III/IV, seizures, hypoxic-ischemic encephalopathy, necrotizing enterocolitis stage II/III, bronchopulmonary dysplasia, persistent pulmonary hypertension), and minor neonatal morbidity (hypotension requiring treatment, intraventricular hemorrhage grade I/II, necrotizing enterocolitis stage I, respiratory distress syndrome, hyperbilirubinemia requiring treatment) were calculated by delivery gestational age; each neonate was classified once by the worst outcome for which criteria was met.

RESULTS

In all, 8334 deliveries met inclusion criteria. There were 119 (1.4%) neonatal deaths. In all, 657 (7.9%) neonates had major morbidity, 3136 (37.6%) had minor morbidity, and 4422 (53.1%) survived without any of the studied morbidities. Deaths declined rapidly with each advancing week of gestation. This decline in death was accompanied by an increase in major neonatal morbidity, which peaked at 54.8% at 25 weeks of gestation. As frequencies of death and major neonatal morbidity fell, minor neonatal morbidity increased, peaking at 81.7% at 31 weeks of gestation. The frequency of all morbidities fell >32 weeks. After 25 weeks, neonatal length of hospital stay decreased significantly with each additional completed week of pregnancy; among babies delivered from 26-32 weeks of gestation, each additional week in utero reduced the subsequent length of neonatal hospitalization by a minimum of 8 days. The median postmenstrual age at discharge nadired around 36 weeks' postmenstrual age for babies born at 31-35 weeks of gestation.

CONCLUSION

Our data show that there is a continuum of outcomes, with each additional week of gestation conferring survival benefit while reducing the length of initial hospitalization. These contemporary data can be useful for patient counseling regarding preterm outcomes.

Bioavailable IGF-1 and its Relation to the Metabolic Syndrome in a Bi-Ethnic Population of Men and Women

Insulin-like growth factor 1 (IGF-1), an insulin sensitivity and vasculoprotective factor, associates negatively with the metabolic syndrome. However, IGF-1 is reduced by factors such as inflammation, oxidative stress and liver dysfunction. We investigated the relationship between bioavailable IGF-1 and the number of metabolic syndrome components and determined whether this relationship is independent of inflammation, oxidative stress and gamma glutamyl transferase (γ-GT; a marker of liver dysfunction). This study included 907 black and white participants stratified by sex (aged 43.0±11.8 years). Among them 63 participants had fasting glucose levels of ≥+7.0+mmol/l and/or used diabetes medication. Via standard methods we determined waist circumference, fasting glucose, triglycerides, high-density lipoprotein cholesterol and blood pressure. We also determined high-sensitivity C-reactive protein (CRP), reactive oxygen species (ROS), γ-GT, IGF-1 and insulin-like growth factor binding protein 3 (IGFBP-3). IGF-1/IGFBP-3 was used as an estimate of bioavailable IGF-1. Total IGF-1 was similar between men and women (p=0.10), however, bioavailable IGF-1 was lower in women (p<0.001). In multivariate-adjusted analyses, IGF-1/IGFBP-3 was inversely associated with the number of metabolic syndrome components in both sexes (men: β=- 0.11; p=0.013 and women: β=- 0.17; p=0.003). Upon inclusion of ROS, γ-GT and CRP, significance was lost. In patients without diabetes, the results for men changed marginally, but were consistent for women. We found an inverse association between bioavailable IGF-1 and the number of metabolic syndrome components. But the relationship was dependent on oxidative stress, liver dysfunction and inflammation, suggesting underlying processes by which the metabolic syndrome attenuates IGF-1.

Glutamine and hyperammonemic crises in patients with urea cycle disorders

Blood ammonia and glutamine levels are used as biomarkers of control in patients with urea cycle disorders (UCDs). This study was undertaken to evaluate glutamine variability and utility as a predictor of hyperammonemic crises (HACs) in UCD patients.

METHODS

The relationships between glutamine and ammonia levels and the incidence and timing of HACs were evaluated in over 100 adult and pediatric UCD patients who participated in clinical trials of glycerol phenylbutyrate.

RESULTS

The median (range) intra-subject 24-hour coefficient of variation for glutamine was 15% (8-29%) as compared with 56% (28%-154%) for ammonia, and the correlation coefficient between glutamine and concurrent ammonia levels varied from 0.17 to 0.29. Patients with baseline (fasting) glutamine values >900 μmol/L had higher baseline ammonia levels (mean [SD]: 39.6 [26.2]μmol/L) than patients with baseline glutamine ≤ 900 μmol/L (26.6 [18.0]μmol/L). Glutamine values >900 μmol/L during the study were associated with an approximately 2-fold higher HAC risk (odds ratio [OR]=1.98; p=0.173). However, glutamine lost predictive significance (OR=1.47; p=0.439) when concomitant ammonia was taken into account, whereas the predictive value of baseline ammonia ≥ 1.0 upper limit of normal (ULN) was highly statistically significant (OR=4.96; p=0.013). There was no significant effect of glutamine >900 μmol/L on time to first HAC crisis (hazard ratio [HR]=1.14; p=0.813), but there was a significant effect of baseline ammonia ≥ 1.0 ULN (HR=4.62; p=0.0011).

CONCLUSIONS

The findings in this UCD population suggest that glutamine is a weaker predictor of HACs than ammonia and that the utility of the predictive value of glutamine will need to take into account concurrent ammonia levels.