In vitro biological responses of plasma nanocoatings for coronary stent applications

In-stent restenosis and thrombosis remain to be long-term challenges in coronary stenting procedures. The objective of this study was to evaluate the in vitro biological responses of trimethylsilane (TMS) plasma nanocoatings modified with NH3 /O2 (2:1 molar ratio) plasma post-treatment (TMS + NH3 /O2 nanocoatings) on cobalt chromium (CoCr) alloy L605 coupons, L605 stents, and 316L stainless steel (SS) stents. Surface properties of the plasma nanocoatings with up to 2-year aging time were characterized by wettability assessment and x-ray photoelectron spectroscopy (XPS). It was found that TMS + NH3 /O2 nanocoatings had a surface composition of 41.21 ± 1.06 at% oxygen, 31.90 ± 1.08 at% silicon, and 24.12 ± 1.7 at% carbon, and very small but essential amount of 2.77 ± 0.18 at% nitrogen. Surface chemical stability of the plasma coatings was noted with persistent O/Si atomic ratio of 1.292-1.413 and N/Si atomic ratio of ~0.087 through 2 years. The in vitro biological responses of plasma nanocoatings were studied by evaluating the cell proliferation and migration of porcine coronary artery endothelial cells (PCAECs) and smooth muscle cells (PCASMCs). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay results revealed that, after 7-day incubation, TMS + NH3 /O2 nanocoatings maintained a similar level of PCAEC proliferation while showing a decrease in the viability of PCASMCs by 73 ± 19% as compared with uncoated L605 surfaces. Cell co-culture of PCAECs and PCASMCs results showed that, the cell ratio of PCAEC/PCASMC on TMS + NH3 /O2 nanocoating surfaces was 1.5-fold higher than that on uncoated L605 surfaces, indicating enhanced selectivity for promoting PCAEC growth. Migration test showed comparable PCAEC migration distance for uncoated L605 and TMS + NH3 /O2 nanocoatings. In contrast, PCASMC migration distance was reduced nearly 8.5-fold on TMS + NH3 /O2 nanocoating surfaces as compared to the uncoated L605 surfaces. Platelet adhesion test using porcine whole blood showed lower adhered platelets distribution (by 70 ± 16%), reduced clotting attachment (by 54 ± 12%), and less platelet activation on TMS + NH3 /O2 nanocoating surfaces as compared with the uncoated L605 controls. It was further found that, under shear stress conditions of simulated blood flow, TMS + NH3 /O2 nanocoating significantly inhibited platelet adhesion compared to the uncoated 316L SS stents and TMS nanocoated 316L SS stents. These results indicate that TMS + NH3 /O2 nanocoatings are very promising in preventing both restenosis and thrombosis for coronary stent applications.

Impact of Immune, Inflammatory, and Nutritional Indices on Outcome in Patients with Cervical Cancer Treated with Definitive (Chemo)radiotherapy

PURPOSE/OBJECTIVE(S)

Systemic immune, inflammatory, and nutritional indices have been shown to be prognostic for outcome across a range of tumor sites. However, a comprehensive analysis of these markers in patients with cervical cancer treated with definitive (chemo)radiotherapy [(C)RT] has not been performed. We hypothesized that systemic immune, inflammatory, and nutritional indices may be associated with progression free survival (PFS) and overall survival (OS) in patients undergoing definitive (C)RT for cervical cancer.

MATERIALS/METHODS

Patients with cervical cancer treated with definitive (C)RT from 1999 - 2015 were identified from a single cancer institution's retrospective clinicopathological database. Pre-treatment immune, inflammatory, and nutritional parameters were collected, and indices derived. Systemic immune-inflammation index (SII) = neutrophil count x platelet count / lymphocyte count(10^9/L); PLR = platelet count / lymphocyte count(10^9/L), NLR = neutrophil count / lymphocyte count (10^9/L); MLR = monocyte count / lymphocyte count (10^9/L); albumin to alkaline phosphatase ratio (AAPR) = serum albumin level (g/L)/alkaline phosphatase level (U/L) and prognostic nutritional index (PNI) = serum albumin (g/L) + 5 x lymphocyte count (10^9/L). Univariate analysis was first performed on each parameter as continuous variables for PFS and OS. For variables with statistically significant associations, ROC curves were analyzed to determine if an optimal cut point could be established for each outcome. Common cut points were then defined for each variable. PFS and OS were analyzed by the Kaplan-Meier method and the Log-Rank test. Multivariate analysis was performed using Cox regression with covariates of tumor stage, histology, and age. P-values of <0.05 were considered statistically significant.

RESULTS

A total of 196 patients were identified; median follow-up 7 years. 131 (67%) had stage I-II and 65 (33%) stage III-IV disease. 187 (95%) received CRT and 9 (5%) RT alone. Higher SII (≤700 vs >700; p = 0.01), higher PLR (≤ 250 vs >250; p<0.001) and higher NLR (≤ 5 vs >5; p = 0.003) were associated with worse PFS. Higher SII [≤700 vs >700: 5y OS 74.9 vs 55.8; p = 0.02], higher PLR [≤ 250 vs >250: 5y OS 69.9% vs 42.0%; p<0.001] and higher NLR [≤ 5 vs >5: 5y OS 65.3% vs 51.0%; p = 0.01] were associated with worse OS. MLR, AAPR and PNI were not associated with outcome on univariate analysis. On multivariate analysis, SII and PLR were independently associated with both PFS [SII: HR 1.647 (CI 1.029-2.639), p = 0.038; PLR: HR 2.301 (95% CI 1.507 - 3.512), p = <0.001], and OS [SII: HR 1.649 (95% CI 1.009-2.696), p = 0.046; PLR: HR 2.212 (95% CI 1.416-3.455), p<0.001]; NLR did not remain statistically significant.

CONCLUSION

SII and PLR, but not nutritional indices, were independently associated with PFS and OS in patients with cervical cancer treated with definitive (C)RT. Further evaluation of these systemic immune and inflammatory indices in a validation set will be required to better define their clinical utility.

Evaluating the Performance of ChatGPT at Breast Tumor Board

PURPOSE/OBJECTIVE(S)

Chat Generative Pre-trained Transformer (ChatGPT) is a chatbot built on the GPT-3 language model. We sought to determine whether it can contribute to tumor board discussions by comparing the accuracy and clarity of its answers to challenging breast radiation oncology questions with that of human specialists.

MATERIALS/METHODS

Twenty consecutive breast radiation oncology questions between January and February 2023 that received at least one human answer were curated from theMedNet, a physician-only Q&A platform for expert answers to real-world clinical situations. These questions were posed to ChatGPT, and its answers were paired with the first chronological human response. Breast radiation oncologists at one academic institution were asked to rate from 1 (strongly disagree) to 5 (strongly agree) the extent to which they agreed with each answer (accuracy score) and whether they felt the response provided clear and specific guidance relevant to the original question (clarity score). Wilson score intervals with continuity correction were used to estimate the proportion of answers on which ChatGPT receives a higher median accuracy or clarity score than human responders. The Wilcoxon signed-rank test was used to compare median accuracy and clarity scores across all of the 20 questions.

RESULTS

Six board-certified breast radiation oncologists evaluated answers to the 20 questions, resulting in 120 distinct assessments of each of ChatGPT and human responders. The evaluators agreed or strongly agreed with ChatGPT responses on 49 (41%) of assessments and human responders on 66 (55%) of assessments. ChatGPT achieved a higher median accuracy score than human responders on 7 (35%; 95% Wilson score CI, 16-59%) questions whereas humans outperformed ChatGPT on 8 (40%) questions; there was no significant difference in median scores (Wilcoxon signed-rank p = 0.3). There was agreement or strong agreement that ChatGPT provided clear and specific guidance on 38 (32%) of assessments compared to 45 (38%) assessments of human answers. No differences were detected in median clarity score across all questions (Wilcoxon signed-rank p = 0.8). On 3 questions (15%; 95% Wilson score CI, 4-39%), ChatGPT surpassed human responders on both median accuracy score and median clarity score. Human responders similarly outperformed ChatGPT in both metrics on 3 (15%) questions.

CONCLUSION

There was no detectable difference in the accuracy or clarity of answers provided by ChatGPT and human responders in this sample of 20 challenging breast radiation oncology questions. ChatGPT outperformed human responders in the accuracy and clarity of its answers to some questions, suggesting that it has the potential to contribute meaningfully to discussions about real-world clinical problems.

Hypomagnesemia and Survival in Patients with Cervical Cancer Treated with Definitive Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

Hypomagnesemia is a common side effect of platinum-based chemotherapy regimens. Although there are data reporting that hypomagnesemia is associated with worse survival in patients receiving platinum-based chemotherapy or chemoradiotherapy (CRT), this has not been documented in patients with cervical cancer treated with definitive CRT. We hypothesized that in patients with cervical cancer undergoing definitive CRT, on-treatment hypomagnesemia would be associated with longer treatment duration and worse cancer-specific survival (CSS).

MATERIALS/METHODS

Patients with cervical cancer treated with definitive CRT from 1999 to 2015 were identified from a single cancer center's clinicopathologic database. Lowest on-treatment magnesium value was recorded and categorized as per Common Terminology Criteria for Adverse Events (CTCAE) v5.0 grading (grade 1: <0.7 - 0.5 mmol/L, grade 2: <0.5 - 0.4 mmol/L, grade 3: <0.4-0.3 mmol/L, and grade 4 <0.3 mmol/L). Grade 0 was defined as ≥ 0.7 mmol/L. Treatment duration was defined as the number of days between the first day of radiotherapy until the last day of pelvic treatment (either brachytherapy or pelvic external beam radiotherapy boost). Prolonged treatment was considered as any treatment duration greater than 63 days. CSS for patients with either grade 0-1 or grade ≥ 2 CTCAE v5.0 magnesium toxicity was estimated using the Kaplan-Meier method, and the Peto & Peto modification to the generalized Gehan-Wilcoxon was used to determine statistical significance between groups. Associations with prolonged treatment duration was explored using logistic regression. P-values of <0.05 were considered statistically significant.

RESULTS

A total of 186 patients were identified; median follow-up was 7 (IQR 2-11) years. 125 (67%) had stage I-II disease and 61 (33%) stage III-IV. Median treatment duration was 51 (IQR 48-57) days. All patients received concurrent weekly cisplatin-based chemotherapy with RT: the majority (n = 133; 72%) received 5 or 6 cycles. 147 (79%) patients received routine IV magnesium infusion with their chemotherapy and 173 (93%) received routine IV mannitol. During treatment the highest CTCAE v5.0 magnesium toxicity score was grade 0-1 in 158 (85%) and grade ≥ 2 in 28 (15%). Magnesium grade ≥ 2 was associated with worse 5-year CSS [grade 0-1: 5yr CSS 67.2%, (95% CI 60.1-75.1); grade ≥ 2: 5yr CSS 50%, (95% CI 34.5-72.4); p = 0.039]. Magnesium status was not associated with an increase in treatment duration [OR 1.465 (95% CI 0.3177 - 6.753); p = 0.625].

CONCLUSION

On-treatment hypomagnesemia ≥ grade 2 (CTCAE v5.0) was associated with worse CSS but did not predict longer treatment duration. This is the first study that shows a detrimental survival impact of on-treatment hypomagnesemia in this patient population. These findings highlight the need to ensure adequate monitoring, support and correction of magnesium during definitive CRT.

Prospective Application of an Artificial Intelligence Decision Support Tool for Applicator and Needle Selection in High-Dose-Rate Brachytherapy for Cervical Cancer Patients

PURPOSE/OBJECTIVE(S)

To assess the performance of an artificial intelligence (AI)-based decision support tool under differing thresholds to determine optimal applicator selection in a prospective clinical setting.

MATERIALS/METHODS

Cervical cancer patients scheduled for high-dose-rate brachytherapy implants with intracavitary tandem and ring (IC) or interstitial tandem and ring (IC/IS) implants in a single tertiary cancer center were eligible for enrollment. Prior to the first brachytherapy implant, a diagnostic MRI was acquired. The clinical target volume and the expected inserted position of the intrauterine tandem and ring were identified and contoured on the T2-MRI. An in-house artificial intelligence-based predicted the need for an IC or IC/IS implant, based on target volume geometric features. For IC/IS implants, an optimal needle arrangement for target coverage was also predicted. Blinded to the AI outcome, a clinical determination was made by the clinician reviewing the MR image. AI algorithm prediction provided a confidence level associated with each decision. The algorithm performance for different confidence thresholds using the IC applicator of 50%, 60%, and 80% was investigated. Performance metrics of the initial clinical determination and the AI prediction were calculated based on the consensus optimal applicator determined from an assessment of planning dosimetry in the first fraction and clinical use for the final brachytherapy implants and fractions. The performance metrics were accuracy, precision, and recall.

RESULTS

A total of 10 eligible patients were accrued between December 2020 and October 2022. Table 1 shows the initial clinical determination and consensus applicator AI predictions that were made with different confidence thresholds. The optimal confidence threshold (60%) yielded performance scores of 80%, 83.3%, and 83.3% for the accuracy, precision, and recall, respectively. The performance metrics were equivalent for the optimal confidence threshold and the initial clinical decision.

CONCLUSION

The AI-based decision support tool shows strong predictive results for a clinical brachytherapy application that is important to patient outcome. This prospective study demonstrates that the algorithm's utility is a critical step in using AI-based tools clinically. Further work to determine the optimal brachytherapy applicator, based on treatment planning dosimetry, is required.

Interchange reconnection as the source of the fast solar wind within coronal holes

The fast solar wind that fills the heliosphere originates from deep within regions of open magnetic field on the Sun called 'coronal holes'. The energy source responsible for accelerating the plasma is widely debated; however, there is evidence that it is ultimately magnetic in nature, with candidate mechanisms including wave heating^1,2 and interchange reconnection^3-5. The coronal magnetic field near the solar surface is structured on scales associated with 'supergranulation' convection cells, whereby descending flows create intense fields. The energy density in these 'network' magnetic field bundles is a candidate energy source for the wind. Here we report measurements of fast solar wind streams from the Parker Solar Probe (PSP) spacecraft⁶ that provide strong evidence for the interchange reconnection mechanism. We show that the supergranulation structure at the coronal base remains imprinted in the near-Sun solar wind, resulting in asymmetric patches of magnetic 'switchbacks'^7,8 and bursty wind streams with power-law-like energetic ion spectra to beyond 100 keV. Computer simulations of interchange reconnection support key features of the observations, including the ion spectra. Important characteristics of interchange reconnection in the low corona are inferred from the data, including that the reconnection is collisionless and that the energy release rate is sufficient to power the fast wind. In this scenario, magnetic reconnection is continuous and the wind is driven by both the resulting plasma pressure and the radial Alfvénic flow bursts.

Adjuvant Radiotherapy in Stage II Endometrial Cancer: Selective De-intensification of Adjuvant Treatment

AIMS

Risk stratification, including nodal assessment, allows for selective de-intensification of adjuvant radiotherapy in stage II endometrial cancer. Patterns of treatment and clinical outcomes, including the use of reduced volume 'mini-pelvis' radiotherapy fields, were evaluated in a population-based study.

MATERIALS AND METHODS

All patients diagnosed with pathological stage II endometrial cancer between 2000 and 2014, and received adjuvant radiotherapy in a regional healthcare jurisdiction were reviewed. Registry data were supplemented by a comprehensive review of patient demographics, disease characteristics and treatment details. The Charlson Comorbidity Score was calculated. Survival and recurrence data were analysed.

RESULTS

In total, 264 patients met the inclusion criteria. Most patients had endometrioid histology (83%); 41% of patients had International Federation of Gynecologists and Obstetricians grade 1 disease. Half (49%) had surgical nodal evaluation; 11% received chemotherapy. Most patients (59%) were treated with full pelvic radiotherapy fields ± brachytherapy. Seventeen per cent of patients received mini-pelvis radiotherapy ± brachytherapy, whereas 24% received brachytherapy alone. Five-year recurrence-free survival was 87% for the entire cohort, with no significant difference by adjuvant radiotherapy approach. Only one patient receiving mini-pelvis radiotherapy ± brachytherapy recurred in the pelvis but outside of the mini-pelvis field. Recorded late toxicity rates were highest for full pelvis radiotherapy + brachytherapy.

CONCLUSION

Risk stratification in a real-world setting allowed for selective de-intensification of adjuvant radiation with equivalent outcomes for stage II endometrial cancer. Mini-pelvis radiotherapy combined with brachytherapy is effective in highly selected patients, with the potential to decrease toxicity without compromising local control. Brachytherapy should be considered in low-risk stage II patients.

Normal ranges of global left ventricular myocardial work indices in adults: a meta-analysis

Background

Non-invasive global myocardial work recently emerged as new parameter to characterize left ventricle function with potential advantages over both ejection fraction and global longitudinal strain.

Purpose

We aimed to perform a meta-analysis of normal ranges of non-invasive left ventricular myocardial work (MW) indices including global constructive work (GCW), global work index (GWI), global wasted work (GWW), and global work efficiency (GWE) and to identify confounding factors that may contribute to variance in reported measures.

Methods

The authors searched four databases, Pubmed, Scopus, Embase, and Cochrane Library through January 2021 using the key terms “myocardial work”,“global constructive work”, “global wasted work”, “global work index”, “global work efficiency”. Studies were included if the articles reported LV myocardial work using 2D transthoracic echocardiography in healthy normal subjects, either in the control group or comprising the entire study cohort. The weighted mean was estimated by using the random effect model with a 95% confidence interval. Heterogeneity across studies was assessed using the I2 test. Publication bias was examined by funnel plot and Egger's regression test.

Results

The search yielded 476 articles. After abstract and full text screening we included 13 datasets with 1665 patients for meta-analysis. The reported normal mean values of GCW and GWI among the studies were 2278 (95% CI, 2167 to 23878; I2=95%), and 2.010 (95% CI, 1922 to 2098, I2=97%), respectively. The mean GWE was 96.0 (95% CI, 95.6% to 96.5; I2=92%), and the mean GWW was 79.7% (95% CI, 68.8% to 90.7%; I2=90%) (Figure). Furthermore, age and gender did not significantly contribute to variations in normal values. No evidence of significant publication bias was observed in the funnel plots and the Egger test.

Conclusion

In this meta-analysis, we provide echocardiographic reference ranges for non-invasive indices of MW. These normal values should serve as a template for clinical and research use for this promising technology.

Funding Acknowledgement

Type of funding sources: None.

Evaluation of the Haemophilus influenzae EUCAST and CLSI disc diffusion methods to recognize aminopenicillin and amoxicillin/clavulanate resistance

OBJECTIVES

Implementation of EUCAST susceptibility testing in an Australian hospital laboratory demonstrated higher rates of aminopenicillin and amoxicillin/clavulanate resistance in Haemophilus influenzae than previously recognized. This study aimed to better define the variability in the detection of β-lactam resistance based on EUCAST and CLSI disc diffusion (DD) methodology, by comparison with the recommended reference method, broth microdilution (BMD), and by concordance with genomic analysis.

METHODS

A total of 100 random H. influenzae isolates were assessed for ampicillin and amoxicillin/clavulanate susceptibility by EUCAST and CLSI DD and BMD. WGS was used to analyse the ftsI gene of a subset of isolates with β-lactam resistance, other than that due to isolated β-lactamase production.

RESULTS

Of the 100 isolates, 32 were categorized as either β-lactamase negative, ampicillin resistant (BLNAR) (n = 18) or β-lactamase positive, amoxicillin/clavulanate resistant (BLPACR) (n = 14) by EUCAST DD. All 18 EUCAST BLNAR isolates were genotypically confirmed by WGS. Five of 18 BLNAR isolates were concordant by CLSI DD, 12 by EUCAST BMD and 4 by CLSI BMD. Nine of 14 EUCAST BLPACR isolates were confirmed by WGS; the remaining 5 were 1 mm below the EUCAST DD breakpoint. Only one isolate was detected as BLPACR by CLSI DD. Group III mutations associated with high-level ampicillin resistance were identified in 10/32 isolates.

CONCLUSIONS

The EUCAST DD susceptibility method is more reliable than either CLSI or BMD for the detection of genotypically defined BLNAR resistance. However, accurate categorization of amoxicillin/clavulanate resistance remains problematic. Continuous and reproducible surveillance of resistance is needed; for this to be possible, robust susceptibility methods are required.

Electron Acceleration during Macroscale Magnetic Reconnection

The first self-consistent simulations of electron acceleration during magnetic reconnection in a macroscale system are presented. Consistent with solar flare observations, the spectra of energetic electrons take the form of power laws that extend more than two decades in energy. The drive mechanism for these nonthermal electrons is Fermi reflection in growing and merging magnetic flux ropes. A strong guide field suppresses the production of nonthermal electrons by weakening the Fermi drive mechanism. For a weak guide field the total energy content of nonthermal electrons dominates that of the hot thermal electrons even though their number density remains small. Our results are benchmarked with the hard x-ray, radio, and extreme ultraviolet observations of the X8.2-class solar flare on September 10, 2017.

Endophthalmitis resulting from gonococcal keratoconjunctivitis

Neisseria gonorrhoeae is a global pathogen with significant morbidity. This bacterium is one of the common causes of sexually transmitted diseases; however, ocular gonococcal infection is rare. The gonococcal ocular infection can lead to ulcerative keratitis and/or corneal perforation. We report a case of endophthalmitis resulting from gonococcal keratoconjunctivitis. Sexual transmission could not be proven in this patient.

Increased detection of carbapenemase-producing Enterobacteriaceae on post-clean sampling of a burns unit's wet surfaces

Wet surface biofilms are a potential reservoir for multidrug-resistant Gram-negative organisms, including carbapenemase-producing Enterobacteriaceae (CPE). Recognition of environmental sources is important in reducing secondary patient transmission. We report the increased detection of blaIMP-4⁺ CPE in environmental samples from floor drains in burns unit shower rooms, when collected following cleaning as compared to pre-cleaning. We propose that disruption of biofilms during cleaning may account for the increased detection of multi-resistant organisms. The results highlight the role of the wet environment as an under-recognized potential source of CPE transmission. Environmental screening focusing on pre-cleaning samples alone will likely underestimate environmental contamination.

Impact of a Brief Group Intervention to Enhance Parenting and the Home Learning Environment for Children Aged 6-36 Months: a Cluster Randomised Controlled Trial

This study evaluated the effectiveness of a group parenting intervention designed to strengthen the home learning environment of children from disadvantaged families. Two cluster randomised controlled superiority trials were conducted in parallel and delivered within existing services: a 6-week parenting group (51 locations randomised; 986 parents) for parents of infants (aged 6–12 months), and a 10-week facilitated playgroup (58 locations randomised; 1200 parents) for parents of toddlers (aged 12–36 months). Each trial had three conditions: intervention (smalltalk group-only); enhanced intervention with home coaching (smalltalk plus); and ‘standard’/usual practice controls. Parent-report and observational measures were collected at baseline, 12 and 32 weeks follow-up. Primary outcomes were parent verbal responsivity and home learning activities at 32 weeks. In the infant trial, there were no differences by trial arm for the primary outcomes at 32 weeks. In the toddler trial at 32-weeks, participants in the smalltalk group-only trial showed improvement compared to the standard program for parent verbal responsivity (effect size (ES) = 0.16; 95% CI 0.01, 0.36) and home learning activities (ES = 0.17; 95% CI 0.01, 0.38) but smalltalk plus did not. For the secondary outcomes in the infant trial, several initial differences favouring smalltalk plus were evident at 12 weeks, but not maintained to 32 weeks. For the toddler trial, differences in secondary outcomes favouring smalltalk plus were evident at 12 weeks and maintained to 32 weeks. These trials provide some evidence of the benefits of a parenting intervention focused on the home learning environment for parents of toddlers but not infants. Trial Registration: 8 September 2011; ACTRN12611000965909.

Expression of DNA damage response proteins in cervical cancer patients treated with radical chemoradiotherapy

OBJECTIVE

The management of locally advanced cervical cancer has improved significantly with the advent of cisplatin-based chemoradiotherapy (CRT) as the primary treatment regimen. Nevertheless, a significant proportion of patients fail to respond or relapse on this treatment and have a very poor prognosis. Our goal was to determine the prognostic value of a panel of proteins involved in detection and repair of DNA damage.

METHODS

We performed fluorescence immunohistochemistry, and used software analysis to assess expression of DNA damage response proteins ATM, DNA-PKcs, PARP-1, Ku70 and Ku86 in 117 pre-treatment specimens from patients with locally advanced cervical cancer. We compared expression to clinicopathologic correlates to determine prognostic significance.

RESULTS

Five-year progression-free survival was significantly lower in the low expressors than in high expressors of ATM (35% vs. 58%, p=0.044) and PARP-1 (24% vs. 61%, p=0.003), and showed a trend to significance for DNA-PKcs (30% vs. 60%, p=0.050). Low expression of the same proteins also correlated significantly with lower overall survival. In multivariable analysis, adjusted for FIGO stage and tumor size, low ATM and PARP-1 expression was significantly associated with both poorer progression-free and overall survival. Pairwise analyses indicated that expression levels of these proteins were correlated.

CONCLUSIONS

Expression of DNA damage response proteins in cervical cancer is associated with outcome in patients treated with CRT. Immunohistochemical analysis of these proteins may be useful in guiding treatment decisions in such patients.

The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients

NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products.

Formula Feeding Predisposes Gut to NSAID-Induced Small Intestinal Injury

Objectives

Breast feeding protects infants from many diseases, including necrotizing enterocolitis, peptic ulceration and infectious diarrhea. Conversely, maternal separation stress and Non-Steroidal Anti-Inflammatory Drugs (NSAID's) can induce intestinal injury and bleeding. This study aimed to evaluate in suckling rats if maternal separation/formula feeding leads to increased intestinal sensitivity to indomethacin (indo)-induced intestinal injury and to look at potential mechanisms involved.

Methods

Nine-day-old rats were dam-fed or separated/trained to formula-feed for 6 days prior to indo administration (5 mg/kg/day) or saline (control) for 3 days. Intestinal bleeding and injury were assessed by measuring luminal and Fecal Hemoglobin (Hob) and jejunal histology. Maturation of the intestine was assessed by measuring luminal bile acids, jejunal sucrase, serum corticosterone, and mRNA expression of ileal Apical Sodium-Dependent Bile Acid Transporter (ASBT).

Results

At 17 days, formula-fed indo-treated pups had a 2-fold increase in luminal Hb compared to formula-fed control pups and had evidence of morphological injury to the small intestinal mucosa as observed at the light microscopic level, whereas indo had no effect on dam-fed littermates. In addition, formula-fed rats had significant increases in luminal bile acid, sucrase specific activity, serum corticosterone, and expression of ASBT mRNA compared to dam-fed rats.

Conclusion

Maternal separation stress may cause early intestinal maturational changes induced by corticosteroid release, including increased epithelial exposure to bile acids. These maturational changes may have a sensitizing rather than protective effect against indo-induced injury in the new-born.

Low-noise heterodyne receiver for electron cyclotron emission imaging and microwave imaging reflectometry

The critical component enabling electron cyclotron emission imaging (ECEI) and microwave imaging reflectometry (MIR) to resolve 2D and 3D electron temperature and density perturbations is the heterodyne imaging array that collects and downconverts radiated emission and/or reflected signals (50-150 GHz) to an intermediate frequency (IF) band (e.g. 0.1-18 GHz) that can be transmitted by a shielded coaxial cable for further filtering and detection. New circuitry has been developed for this task, integrating gallium arsenide (GaAs) monolithic microwave integrated circuits (MMICs) mounted on a liquid crystal polymer (LCP) substrate. The improved topology significantly increases electromagnetic shielding from out-of-band interference, leads to 10× improvement in the signal-to-noise ratio, and dramatic cost savings through integration. The current design, optimized for reflectometry and edge radiometry on mid-sized tokamaks, has demonstrated >20 dB conversion gain in upper V-band (60-75 GHz). Implementation of the circuit in a multi-channel electron cyclotron emission imaging (ECEI) array will improve the diagnosis of edge-localized modes and fluctuations of the high-confinement, or H-mode, pedestal.

Bioavailability of aspirin in rats comparing the drug's uptake into gastrointestinal tissue and vascular and lymphatic systems: implications on aspirin's chemopreventive action

Aspirin is an effective analgesic and antiplatelet drug that in addition to its ability to reduce pain, inflammation and fever, appears to have efficacy in the prevention/treatment of a range of diseases including heart disease, numerous cancers and Alzheimer's. It is important to understand the bioavailability of aspirin and its major metabolite, salicylic acid, since dosage and route of administration can vary for treating differing diseases, and the major side-effects of aspirin, upper gastrointestinal ulceration and bleeding, are dose-dependent. We examined the time course for gastroduodenal uptake of aspirin and the appearance of its major metabolite salicylic acid in blood and lymph after intragastric (to simulate oral) and intraduodenal (to simulate enteric-coating) dosing in rats. Results show that after intragastric dosing, intact aspirin is absorbed primarily by the gastric mucosa and to a lesser extent by the duodenal mucosa. When aspirin is dosed intragastrically or intraduodenally, a much greater concentration of aspirin enters the lymph than the blood. In contrast, the concentration of salicylic acid was higher in blood than in lymph. Lymph levels of both aspirin and salicylic acid were sufficiently high so as to perform a pharmacologic function there, possibly as a chemopreventive agent against colon cancer and potentially the metastatic spread of non-gastrointestinal cancers.

The changing landscape of brachytherapy for cervical cancer: a Canadian practice survey

BACKGROUND

We documented changes in practice from 2009 to 2012 for cervical cancer brachytherapy in Canada.

METHODS

Centres with gynecologic brachytherapy services were sent an e-mail questionnaire querying their 2012 practice. Responses are reported and compared with practice patterns identified in a similar survey for 2009.

RESULTS

The response rate was 77% (24 of 31 centres). Almost all use high-dose-rate brachytherapy (92%); low-dose-rate brachytherapy has been completely phased out. Most continue to move patients from the site of applicator insertion to the radiation treatment simulation suite (75%) or to a diagnostic imaging department (29%), or both. In 2012, the imaging modalities used for dose specification were computed tomography [ct (75%)], magnetic resonance imaging [mri (38%)], plain radiography (21%), and cone-beam ct (8%). The number of institutions using mri guidance has markedly increased during the period of interest (9 vs. 1). Most respondents (58% vs. 14%) prescribed using guidelines from the Groupe Européen de Curiethérapie and the European Society for Therapeutic Radiology and Oncology, but they also used point A as a reference. Commonly used high-dose radiation regimens included 30 Gy in 5 fractions and 24 Gy in 3 fractions.

CONCLUSIONS

In Canada, image-guided brachytherapy for cervical cancer continues to evolve. Although ct-based imaging remains the most commonly used modality, many centres have adopted mri for at least 1 brachytherapy treatment. More centres are using fewer fractions and a slightly lower biologically effective dose, but are still achieving EQD2 (2-Gy equivalent) doses of 80-90 Gy in combination with external-beam radiation therapy.

Recent vaccine development for human metapneumovirus

Human metapneumovirus (hMPV) and respiratory syncytial virus, its close family member, are two major causes of lower respiratory tract infection in the paediatric population. hMPV is also a common cause of worldwide morbidity and mortality in immunocompromised patients and older adults. Repeated infections occur often, demonstrating a heavy medical burden. However, there is currently no hMPV-specific prevention treatment. This review focuses on the current literature on hMPV vaccine development. We believe that a better understanding of the role(s) of viral proteins in host responses might lead to efficient prophylactic vaccine development.

Ara h 1 CD4+ T cell epitope-based peptides: candidates for a peanut allergy therapeutic

Background

Peanut allergy is a life-threatening condition; there is currently no cure. While whole allergen extracts are used for specific immunotherapy for many allergies, they can cause severe reactions and even fatalities in peanut allergy.

Objective

To identify short, HLA-degenerate CD4⁺ T cell epitope-based peptides of the major peanut allergen Ara h 1 that target allergen-specific T cells without causing IgE-mediated inflammatory cell activation, as candidates for safe peanut-specific immunotherapy.

Methods

Ara h 1-specific CD4⁺ T cell lines (TCL) were generated from peripheral blood mononuclear cells (PBMC) of peanut-allergic subjects using CFSE-based methodology. T cell epitopes were identified using CFSE and thymidine-based proliferation assays. Epitope HLA-restriction was investigated using blocking antibodies, HLA-genotyping and epitope prediction algorithms. Functional peanut-specific IgE reactivity to peptides was assessed by basophil activation assay.

Results

A total of 145 Ara h 1-specific TCL were generated from 18 HLA-diverse peanut-allergic subjects. The TCL recognized 20-mer peptides throughout Ara h 1. Nine 20-mers containing the most frequently recognized epitopes were selected and their recognition confirmed in 18 additional peanut-allergic subjects. Ten core epitopes were mapped within these 20-mers. These were HLA-DQ and/or HLA–DR restricted, with each presented on at least two different HLA-molecules. Seven short (≤ 20 aa) non-basophil-reactive peptides encompassing all core epitopes were designed and validated in peanut-allergic donor PBMC T cell assays.

Conclusions and Clinical Relevance

Short CD4⁺ T cell epitope-based Ara h 1 peptides were identified as novel candidates for a safe, T cell targeted peanut-specific immunotherapy for HLA-diverse populations.

Design and feasibility studies of a stationary digital breast tomosynthesis system

Studies have shown that digital breast tomosynthesis (DBT) can improve breast cancer diagnosis by reconstructing 3D images. However, DBT scanners based on rotation gantry prolong the imaging time and reduce spatial resolution due to motion comparing with the regular two-view mammography. To obtain three dimension reconstruction images and maintain the high image quality of conventional mammography, we proposed a prototype stationary digital breast tomosynthesis system (s-DBT). The proposed s-DBT system acquires projection images without mechanical movement. The core component of the s-DBT system is a specially designed spatially distributed multi-beam x-ray tube based on the carbon nanotube field emission x-ray technology. The multi-beam x-ray source array enables collection of all projection images from different viewing angles without mechanical motion. Preliminary results show the s-DBT system can achieve a scan time comparable to the regular two-view mammography, and improve the spatial resolution comparing with rotating gantry DBT.

Aspirin's ability to induce intestinal injury in rats is dependent on bile and can be reversed if pre-associated with phosphatidylcholine

Clinical evidence suggests that aspirin and particularly enteric-coated aspirin induce significant injury to the lower gut. We have reported that NSAID injury to the small bowel is exacerbated by bile acids and that phosphatidylcholine (PC) can protect against this damage. Using a recently described method, we intra-duodenally administered either: saline, aspirin or aspirin pre-associated with PC. The rats were euthanized 90 minutes later at which time we assessed: tissue injury morphologically, vascular permeability with i.v. administered Evan's blue and intestinal bleeding by measuring luminal hemoglobin. In a separate experiment, aspirin-induced injury was studied in rats whose bile duct was ligated either alone or in the presence of rat bile (collected from donor animals). Intra-duodenal administration of aspirin induced mucosal injury (observed histologically), an increase in vascular permeability and blood loss into the intestinal lumen, all of which could be attenuated if the NSAID was pre-associated with PC. Furthermore, using 100 mg/kg dose of aspirin it was determined that bile duct ligation (BDL) significantly reduced aspirin-induced intestinal bleeding which was not different from control rats. Lastly, it was determined that intestinal bleeding was significantly increased in rats with BDL if the aspirin was administered in rodent bile. Aspirin-induced intestinal injury and bleeding in the rat is dependent on the presence of luminal bile, which is likely attributable to it's constituent bile acids. Pre-association of aspirin with PC provides a novel therapeutic approach to significantly reduce aspirin-induced small intestinal injury and bleeding, as may occur with enteric-coated aspirin.

Osteoblast Attachment on Biomaterials as a Function of Surface Charge

Bioactive materials such as calcium phosphate ceramics and bioactive glasses enhance bone tissue formation and then bond to bone tissue. In our work, we question what particular surface feature or features of bioactive materials are responsible for the bone tissue response. In this study we have uncoupled surface charge from surface chemistry, energy, and topography and have examined osteoblast adhesion to titanium surfaces of varying surface charge. We have shown that a negative surface charge promotes osteoblast adhesion by approximately 60% over a neutral surface and that conversely, a positive surface charge inhibits osteoblast adhesion by about 20%. Continued examination of surface characteristics that control cellular responses are warranted with the eventual goal of applying those desirable surface characteristics to any structural biomaterial for bone implant or tissue engineering applications.