Deciphering the water quality impacts of COVID-19 human mobility shifts in estuaries surrounding New York City

The COVID-19 pandemic altered human mobility, particularly in large metropolitan areas. In New York City (NYC), stay-at-home orders and social distancing led to significant decreases in commuting, tourism, and a surge of outward migration. Such changes could result in decreased anthropogenic pressure on local environments. Several studies have linked COVID-19 shutdowns with improvements in water quality. However, the bulk of these studies primarily focused on short-term impacts during shutdown periods, without assessing longer-term impacts as restrictions eased. Here, we examine both concurrent lockdown and societal reopening impacts on water quality, using pre-pandemic baseline conditions, in two highly urbanized estuaries surrounding NYC, the New-York Harbor estuary and Long Island Sound (LIS). We compiled datasets from 2017 to 2021 of mass-transit ridership, work-from-home trends, and municipal wastewater effluent to assess changes in human mobility and anthropogenic pressure during multiple waves of the pandemic in 2020 and 2021. These were linked to changes in water quality assessed using high spatiotemporal ocean color remote sensing, which provides near-daily observations across the estuary study regions. To distinguish anthropogenic impacts from natural environmental variability, we examined meteorological/hydrological conditions, primarily precipitation and wind. Our results show that nitrogen loading into the New York Harbor declined significantly in the spring of 2020 and remained below pre-pandemic values through 2021. In contrast, nitrogen loading into LIS remained closer to the pre-pandemic average. In response, water clarity in New-York Harbor significantly improved, with less of a change in LIS. We further show that changes in nitrogen loading had higher impact on water quality than meteorological conditions. Our study demonstrates the value of remote sensing observations in assessing water quality changes when field-based monitoring is hindered and highlights the complex nature of urban estuaries and their heterogeneous response to changes in extreme events and human behavior.

CTIM-29. PHASE 2 STUDY OF A NOVEL IMMUNOTHERAPY SL-701 IN ADULTS WITH RECURRENT GBM: IDENTIFICATION OF TREATMENT-INDUCED CD8+CD107A+ CD57+ PD-1- MEMORY T-CELLS THAT ARE ASSOCIATED WITH INCREASED SURVIVAL

Recurrent glioblastoma (GBM) is an aggressive disease with poor survival and limited treatment options. SL-701 is a novel immunotherapy comprised of synthetic peptides designed to elicit an anti-tumor immune response against GBM antigens IL-13Rα2, ephrinA2, and survivin. Here we describe an 18-color flow cytometry analysis from stage 2 of a Ph2 clinical trial of SL-701+poly-ICLC+bevacizumab (NCT02078648), in which 12-month overall survival (OS) was 50%. Of the 27 patients in stage 2, 24 (89%) developed heterogeneous T-cell responses against 1, 2, or 3 of the SL-701 CD8 peptides. Magnitude and kinetics of peptide responses were variable among these patients with no clear relationship to OS. Therefore, a phenotypic analysis of the T-cell response in all 27 patients was conducted using terraFlow, a unique data analysis approach utilizing machine learning to identify T-cell phenotypes associated with clinical response from all possible combinations of markers. In total, 10,184 unique SL-701 induced phenotypes were measured, including 223 phenotypes (P < 0.05) and 16 core phenotypes that uniquely represent differences between patients with OS above or below 12 months (P < 0.05). 50% of the core phenotypes were CD8+ CD57+ CD107a+ PD-1- SL-701-specific T-cells, which are highly-differentiated memory T-cells primed for cytotoxicity. The frequency of the CD57+ core phenotypes (8%-18%) was enhanced 1.6- to 2.3-fold in patients with an OS > 12 months (P < 0.05). Similarly, 2 core phenotypes identified cytotoxic CD4+ and CD8+ T cells, which were enhanced 1.9- and 2.5-fold in patients with an OS >12 months. The final 6 core phenotypes identified activated CD4+ CD154+ SL-701-specific T-cells (5%-19%) that were enhanced 0.3- to 0.5-fold in patients with an OS < 12 months (P < 0.05), suggesting helper T-cell responses in the absence of cytotoxic T-cell responses are associated with an OS < 12 months. Deep sequencing of SL-701-specific T-cells using whole transcriptome-based molecular cytometry is planned.

Optical classification of an urbanized estuary using hyperspectral remote sensing reflectance

Optical water classification based on remote sensing reflectance (R_rs(λ)) data can provide insight into water components driving optical variability and inform the development and application of bio-optical algorithms in complex aquatic systems. In this study, we use an in situ dataset consisting of hyperspectral R_rs(λ) and other biogeochemical and optical parameters collected over nearly five years across a heavily urbanized estuary, the Long Island Sound (LIS), east of New York City, USA, to optically classify LIS waters based on R_rs(λ) spectral shape. We investigate the similarities and differences of discrete groupings (k-means clustering) and continuous spectral indexing using the Apparent Visible Wavelength (AVW) in relation to system biogeochemistry and water properties. Our R_rs(λ) dataset in LIS was best described by three spectral clusters, the first two accounting for the majority (89%) of R_rs(λ) observations and primarily driven by phytoplankton dynamics, with the third confined to measurements in river and river plume waters. We found AVW effective at tracking subtle changes in R_rs(λ) spectral shape and fine-scale water quality features along river-to-ocean gradients. The recently developed Quality Water Index Polynomial (QWIP) was applied to evaluate three different atmospheric correction approaches for satellite-derived R_rs(λ) from the Sentinel-3 Ocean and Land Colour Instrument (OLCI) sensor in LIS, finding Polymer to be the preferred approach. Our results suggest that integrative, continuous indices such as AVW can be effective indicators to assess nearshore biogeochemical variability and evaluate the quality of both in situ and satellite bio-optical datasets, as needed for improved ecosystem and water resource management in LIS and similar regions.

Esophageal cooling during ablation of persistent atrial fibrillation is associated with improved freedom from arrhythmia at one-year follow up

Background

Various factors influence successful freedom from atrial arrhythmia after pulmonary vein isolation (PVI) with radiofrequency (RF) ablation for the treatment of atrial fibrillation (AF). Lesion transmurality and continuity (as measured by the Continuity Index) are two important factors, and these can be worsened by pauses in RF energy application due to esophageal overheating. Proactive esophageal cooling precludes the need for premature cessation of power, avoiding partially-formed lesions and the need to “hop-scotch” in the left atrium. The resulting improvement in lesion continuity may improve long-term freedom from atrial arrhythmia after PVI, particularly in patients with persistent AF, where more posterior wall ablation is often necessary.

Purpose

Determine differences in freedom from arrhythmia at one year between patients receiving LET monitoring and those receiving esophageal cooling during PVI for persistent AF.

Methods

We reviewed data from two healthcare systems for patient rhythm status at one-year follow up after PVI for the treatment of persistent or long-standing persistent AF. We then determined Kaplan-Meier estimates of freedom from arrhythmia (AF, atrial flutter, and atrial tachycardia), and compared these between patients receiving esophageal cooling and those treated with traditional LET monitoring.

Results

A total of 252 patients received PVI for persistent or long-standing persistent AF and had data available for review. Of these, 148 received LET monitoring (with either a single or multi-sensor temperature probe), and 104 received active cooling with a dedicated esophageal cooling device. Mean age and gender for each group was similar (67.2, range 21 to 88 years, 36% female for LET monitoring, and 67.8, range 32 to 89 years, 30% female for esophageal cooling). KM estimates for freedom from AF at the one-year follow-up were 44.2% for LET monitored patients and 79.3% for actively cooled patients (P=0.01).

Conclusions

Freedom from atrial arrhythmia at one-year after PVI for persistent AF is associated with significant improvement when using active esophageal cooling rather than LET monitoring.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Attune Medical

Arrhythmia recurrence reduction with an active esophageal cooling device during radiofrequency ablation

Funding Acknowledgements

Type of funding sources: None.

Background

As the burden of atrial fibrillation continues to rise with an aging population, there have been contrasting positions on the efficacy of left atrial ablation. While ablation techniques have continued to improve over the past decades, arrhythmia recurrence rates must be further reduced given the burden of ablation on patients. Since continuity of lesion sets has been associated with greater lesion durability, it has been theorized that the use of active esophageal cooling may facilitate greater freedom from arrhythmia.

Purpose

In order to investigate the association between use of active esophageal cooling and arrhythmia recurrence, we performed a multicenter retrospective study of arrhythmia recurrence rates in patients that received active cooling and compared them to those that received luminal esophageal temperature (LET) monitoring.

Methods

In this study, follow up data were collected from patients that underwent pulmonary vein isolation (PVI) at three separate large medical centers. Data were contained in a prospective hospital registry, a prospective physician registry, or the electronic health record, depending on the center. For each patient included, we recorded whether their ablation utilized LET monitoring or active esophageal cooling, along with their rhythm status at 1-year follow up. Rhythm status at follow-up was determined by either electrocardiogram, Holter monitor, or wearable heart rate monitor. Kaplan-Meier (KM) curves were created for freedom-from-arrhythmia at one year comparing those in the LET monitoring group to those in the active cooling group.

Results

Follow up data were collected from 1035 patients. There were 560 patients that received LET monitoring during their original ablation, and 475 patients that underwent active esophageal cooling. KM estimates for freedom-from-arrhythmia at one year were 42% in the LET monitored group and 65% in the actively cooled group (P<.001).

Conclusion

In this large multicenter study, there is a significant increase in freedom-from-arrhythmia at one year follow-up among patients that received active esophageal cooling as compared to those that underwent LET monitoring.

Effect of a proactive esophageal cooling device on procedure length - a multicenter comparison of persistent and paroxysmal atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

During left atrial ablation for the treatment of atrial fibrillation (AF), effective esophageal protection is essential for reducing or preventing thermal injury. Traditional methods include luminal esophageal temperature (LET) monitoring that lead to frequent pauses in the procedure when temperature alarms alert operators to dangerous temperature levels. While there have been recent studies that demonstrate an association between active esophageal cooling and a reduction in procedure duration regardless of AF type, these retrospective studies have been conducted at single or joint centers which may lead to confounding from other time-saving variables that have changed over time.

Purpose

Consequently, we sought to perform a large-scale multicenter comparison to better elucidate the association between procedure length and the use of active cooling in patients with persistent and paroxysmal atrial fibrillation.

Methods

In this study, we collected data from three large hospital centers, one hospital-maintained registry, one physician-maintained registry, and one through EHR data review and aggregated in groups separated by AF type as well as whether the patients received active cooling or LET monitoring. We then compared median procedure durations in each group.

Results

There were a total of 753 patients included in this study. Of the 360 patients with paroxysmal AF, 179 received active esophageal cooling while 181 underwent LET monitoring. In the persistent AF group with 393 patients, 157 received active esophageal cooling and 236 underwent LET monitoring. Among patients with paroxysmal AF, the median mean procedure duration was 137 minutes in the LET monitored group, and 90 minutes in the actively cooled group with an overall reduction of 47 minutes (P<.001). In patients with persistent AF, the median procedure duration was 148 minutes in the LET monitored group and 94 minutes in the actively cooled group with an overall reduction of 54 minutes (P<.001). The relative reduction as a percent of total procedure time was 34%, and 36%, for paroxysmal and persistent AF cases, respectively.

Conclusion

In this large multicenter review, there is a significant reduction in procedure length when using active esophageal cooling, regardless of AF type.

Radio-Pathomic Maps of Cell Density Identify Brain Tumor Invasion beyond Traditional MRI-Defined Margins

BACKGROUND AND PURPOSE

Currently, contrast-enhancing margins on T1WI are used to guide treatment of gliomas, yet tumor invasion beyond the contrast-enhancing region is a known confounding factor. Therefore, this study used postmortem tissue samples aligned with clinically acquired MRIs to quantify the relationship between intensity values and cellularity as well as to develop a radio-pathomic model to predict cellularity using MR imaging data.

MATERIALS AND METHODS

This single-institution study used 93 samples collected at postmortem examination from 44 patients with brain cancer. Tissue samples were processed, stained with H&E, and digitized for nuclei segmentation and cell density calculation. Pre- and postgadolinium contrast T1WI, T2 FLAIR, and ADC images were collected from each patient's final acquisition before death. In-house software was used to align tissue samples to the FLAIR image via manually defined control points. Mixed-effects models were used to assess the relationship between single-image intensity and cellularity for each image. An ensemble learner was trained to predict cellularity using 5 × 5 voxel tiles from each image, with a two-thirds to one-third train-test split for validation.

RESULTS

Single-image analyses found subtle associations between image intensity and cellularity, with a less pronounced relationship in patients with glioblastoma. The radio-pathomic model accurately predicted cellularity in the test set (root mean squared error = 1015 cells/mm²) and identified regions of hypercellularity beyond the contrast-enhancing region.

CONCLUSIONS

A radio-pathomic model for cellularity trained with tissue samples acquired at postmortem examination is able to identify regions of hypercellular tumor beyond traditional imaging signatures.

CTIM-11. PHASE 2 STUDY OF SL-701, A NOVEL IMMUNOTHERAPY, IN ADULTS WITH RECURRENT GBM: A HIGH PARAMETER FLOW CYTOMETRY ANALYSIS OF CD8+ T CELLS AND POTENTIAL IMPLICATIONS FOR PATIENT ENRICHMENT STRATEGIES

Treatment of glioblastoma (GBM) remains a critical challenge and unmet medical need due to limited treatment options. SL-701 is a novel immunotherapy comprised of synthetic peptides designed to elicit a target-specific anti-tumor immune response against the GBM antigens IL-13Rα2, ephrinA2, and survivin. A multicenter, 2-stage, phase 2 clinical trial (NCT02078648) that evaluated the safety and efficacy of SL-701 in 74 adults with recurrent GBM was previously reported. This report describes preliminary data to suggest a correlation of immunocompetence to clinical outcome. In stage 2 (SL-701 + bevacizumab + poly-ICLC) the overall survival at 12 months was 50%. Two of 28 patients enrolled in stage 2 achieved CR (duration of response: 7.8 and 8.8 months) and 2 achieved PR (duration of response: 7.9 and 8.8 months). In a preliminary analysis to assess CD8+ T-cell responses, long-term survivors were comprised largely of subjects with an SL-701-induced target-specific CD8+ T-cell response, indicating a potential correlation of immunocompetence to clinical outcome. By week 24, SL-701-induced target-specific CD8+ T cells expressing IFNg were detected in 8 of 27 patients (30%) who had sufficient samples, with co-expression of PD-1, TIM3, and LAG3 detected in 4 patients. To further understand the T-cell response to SL-701, deep sequencing of target-specific CD8+ T cells using whole transcriptome-based molecular cytometry and high parameter (25+ color) flow cytometry is currently underway and updated data will be reported.

Pediatric surgical wait priority score (pSWAPS): Modifying a health system's adult-based elective surgery prioritization system for children's surgery during the COVID-19 pandemic

BACKGROUND

With the rise of COVID-19 cases, societies recommended canceling all elective surgical procedures because of perioperative concerns, transmission risk, and the need to divert resources. Once the number of cases stabilized, there was recognition that a system was needed to triage and prioritize scheduling operations.

METHODS

A universal scoring system to triage surgical elective cases was developed for the Advocate Aurora Health system (Surgical Wait Priority Score, SWAPS) and was modified for use in pediatrics (pSWAPS). Resource-related, patient-related, and case urgency factors were used to create the overall score. Interrater reliability of ten cases was determined by four surgeons' scores and calculating Fleiss' Kappa coefficient. The system has been used for two months at two operating rooms with different resource restrictions with the goal of prioritizing elective cases.

RESULTS

18 factors were identified as significant contributors to the pWAPS creating a cumulative score ranging from 0 to 120. In the first month, 61 and 99 procedures were screened at the Oak Lawn (OL) and Park Ridge (PR) campuses respectively, and in the second month, 94 (OL) and 135 (PR) procedures were evaluated. The average pSWAPS scores were 37.9 at OL and 54.3 at PR. All cases that had scores within the immediate group were scheduled and completed.

CONCLUSION

The pSWAPS system is a simple, flexible scoring system that takes into consideration resource constraints. pSWAPS has been used for two months. It has served as an effective tool for safe and methodical reintroduction of elective procedures during the COVID-19 pandemic and could be used again for another surge.

LEVEL OF EVIDENCE

prognosis study, level of evidence - 4.

Cold Atmospheric Plasma as a Novel Therapeutic Tool for the Treatment of Brain Cancer

BACKGROUND

Studies from the past few years revealed the importance of Cold Atmospheric Plasma (CAP) on various kinds of diseases, including brain cancers or glioblastoma (GBM), and hence coined a new term 'Plasma Medicine' in the modern world for promising therapeutic approaches. Here, we focus on the efficacy of CAP and its liquid derivatives on direct interactions or with specific nanoparticles to show pivotal roles in brain cancer treatment.

METHOD

In the present review study, the authors studied several articles over the past decades published on the types of CAP and its effects on different brain cancers and therapy.

RESULTS

A growing body of evidence indicates that CAP and its derivatives like Plasma Activated Media/ Water (PAM/PAW) are introduced in different kinds of GBM. Recent studies proposed that CAP plays a remarkable role in GBM treatment. To increase the efficacy of CAP, various nanoparticles of different origins got specific attention in recent times. In this review, different strategies to treat brain cancers, including nanoparticles, are discussed as enhancers of CAP induced targeted nanotherapeutic approach.

CONCLUSION

CAP treatment and its synergistic effects with different nanoparticles hold great promise for clinical applications in early diagnosis and treatment of GBM treatment. However, results obtained from previous studies were still in the preliminary phase, and there must be a concern over the use of optimal methods for a dosage of CAP and nanoparticles for complete cure of GBM.

Photosynthetic energy conversion efficiency in the West Antarctic Peninsula

The West Antarctic Peninsula (WAP) is a highly productive polar ecosystem where phytoplankton dynamics are regulated by intense bottom-up control from light and iron availability. Rapid climate change along the WAP is driving shifts in the mixed layer depth and iron availability. Elucidating the relative role of each of these controls and their interactions is crucial for understanding of how primary productivity will change in coming decades. Using a combination of ultra-high-resolution variable chlorophyll fluorescence together with fluorescence lifetime analyses on the 2017 Palmer Long Term Ecological Research cruise, we mapped the temporal and spatial variability in phytoplankton photophysiology across the WAP. Highest photosynthetic energy conversion efficiencies and lowest fluorescence quantum yields were observed in iron replete coastal regions. Photosynthetic energy conversion efficiencies decreased by ~ 60% with a proportional increase in quantum yields of thermal dissipation and fluorescence on the outer continental shelf and slope. The combined analysis of variable fluorescence and lifetimes revealed that, in addition to the decrease in the fraction of inactive reaction centers, up to 20% of light harvesting chlorophyll-protein antenna complexes were energetically uncoupled from photosystem II reaction centers in iron-limited phytoplankton. These biophysical signatures strongly suggest severe iron limitation of photosynthesis in the surface waters along the continental slope of the WAP.

INNV-13. SYNERGISTIC EFFECT OF COLD ATMOSPHERIC PLASMA IN COMBINATION WITH TEMOZOLOMIDE TO TREAT GLIOBLASTOMA IN A NON-INVASIVE MOUSE XENOGRAFT MODEL

INTRODUCTION

A primary limitation in anti-cancer therapy is the resistance of cancer cells to chemotherapeutic drugs. However, combination therapy may be an effective approach for reducing drug derived toxicity and evading drug resistance, resulting in improved clinical treatment of cancer. Our prior work demonstrated effective treatment of glioblastoma (GBM) with cold atmospheric plasma (CAP) technology with minimal effect to normal cells. Consequently, CAP may serve as a strong candidate for combination therapy with the classical antineoplastic alkylating agent Temozolomide (TMZ) to treat GBM.

OBJECTIVES

To determine the in vivo co-efficacy of CAP and TMZ to “sensitize” GBM.

METHODS

An in vivo study was performed using the CAP jet device (He-gas) to determine the effect of combined CAP–TMZ treatment. U87MG-luc glioblastoma cells were implanted intracranially in athymic nude NU(NCr)-Foxn1nu/immunodeficient mice. He-CAP (or control He alone) was non-invasively applied over the skin for 60sec to developed tumors on the first day of the treatment followed with 6.5 mg/kg TMZ or vehicle control treatment for 5 days for two weeks (n=5/group). In vivo bioluminescence imaging was used to monitor tumor volume on the 6th, 9th and 13th treatment day.

RESULTS

In vivo bioluminescence imaging revealed a marked 8.0±3.2 fold increase in tumor volume in control animals (He-vehicle). Treatment with He-TMZ (6.7±2.5 fold) or CAP-vehicle (4.8±1.7 fold) in isolation had minimal effect in preventing tumor growth. However, combined CAP-TMZ co-treatment virtually prevented increases in tumor volume over 2 weeks (1.8±0.2 fold).

CONCLUSIONS

Collectively, these findings indicate an effective synergistic treatment method for GBM combining CAP with TMZ. Future investigations look to incorporate radiation into the treatment regimen as well as primary GBM cell models.

INNV-08. COMPARATIVE STUDY OF THE CANCER TREATMENT POTENTIAL EFFECT OF TUMOR-TREATING FIELDS AND COLD ATMOSPHERIC PLASMA

INTRODUCTION

Cold Atmospheric Plasma (CAP) is ionized gas close to room temperature that generates reactive oxygen and nitrogen species, an electromagnetic field (EMF) and UV, which are selectively cytotoxic to cancer cells. Tumor Treating Fields (TTFields) is an FDA approved cancer treatment that utilizes “low intensity” and “intermediate frequency” alternating electric fields to produce an inhibitory effect on cancerous cells.

OBJECTIVES

In this study, we directly compared CAP and TTFields treatments using U87 glioblastoma tumor cells. We aimed to assess the relative merits of both technologies as potential approaches for brain cancer treatment.

METHODS

In this in vitro study, the cells were treated with either CAP or TTFields at room temperature. In both cases in order the optimize the treatment parameters, the energy we applied was varied for both methods by changing the power and time of the treatment. The resulting cell viability changes were measured 72 hours after treatment.

RESULTS

The results revealed that increased energy resulted in decreased cell viability of U87 glioblastoma tumor cells with both CAP and TTFields treatment. The rate of U87 glioblastoma tumor cell viability under CAP treatment was 80% of the original viability after using 4.8J of energy, compared with 15,752J of energy with TTFields treatment. Additionally, the CAP displayed significantly greater time-efficiency as compared to TTFields. For instance, the most effective TTFields treatment took 4 hours, while the CAP treatment displayed a comparable effect on tumor cell viability with a treatment time of 30 seconds.

CONCLUSIONS

This preliminary in vitro study indicates that CAP treatment is potentially a more favorable effective method of brain cancer therapy. This data indicates that CAP is significantly more energy-efficient and requires significantly less treatment time than TTFields. Future research looks to compare the 2 treatments in an intracranial mouse xenograft model.

Sustainability in Dentistry: A Multifaceted Approach Needed

This article provides an introduction to environmentally sustainable dentistry and offers perspectives on managing drivers to reduce carbon emissions and make dentistry more environmentally sustainable. A sustainable world must meet the needs of the present without compromising the ability of future generations to meet their own needs. Global commitment to sustainability and demands for a sustainable world are growing. Within dentistry, travel creates the highest carbon emissions and also contributes to human health damage. Internally, there are a number of ways to reduce impact by decreasing travel and energy use, as well as carefully considering the types of items purchased (and how they are disposed of). Larger dental organizations can influence their suppliers and industry by choosing to purchase from sustainable companies with environmentally friendly products. From an external driver perspective policy, guidance and research are essential. Governments need to reevaluate decontamination policy from an environmental perspective. Decontamination documents need revision to consider both planetary and public health. Dental organizations need to support dental teams in this area. Insurance providers and health care purchasers should review policies to influence the sustainability of dental providers. Sustainability education needs to be considered as part of the curriculum of undergraduate and postgraduate students. Guidance could also be developed for the dental industry to produce sustainable products. Research needs to be prioritized. Identifying hot spots or areas of high environmental contributions using other assessments such as life cycle analysis (LCA) would allow dentistry to identify products or practices that have a disproportionate adverse impact on the environment and might be prioritized for change. This should include an analysis of single-use instruments, chemicals, and products. Building research capacity by training students and creating virtual or physical centers for sustainability is essential. Financial support is needed for priority areas of research.

EXTH-10. THE ACTIVATION AND SENSITIZATION OF GLIOBLASTOMA CELLS VIA COLD ATMOSPHERIC PLASMA TREATMENT

BACKGROUND

Treatment of glioblastoma multiforme (GBM) continues to remain a challenge using conventional treatment. Through an in vitro study we assessed the efficacy of our novel cold atmospheric plasma technology (CAP) to sensitize GBM cells to temozolomide (TMZ).

METHODS

The CAP jet is formed through the discharge (Pk-Pk: 5.8 kV) between a ring grounded cathode and a central anode and with He flow through a glass tube. The discharge process is driven by an AC high voltage (3.16 kV) with a frequency of 12.5 kHz. Human glioblastoma (U87MG) cells were cultured in DMEM supplemented by 1% (v/v) penicillin and streptomycin solution and 10% (v/v) FBS. CAP was delivered to U87 cells in a 96-well plate for 1 min in combination with 10 and 15 μM H2O2. The cell viability was measured by using the MTT assay. We then tested TMZ concentrations of 10 and 50 uM. Cell viability was monitored with the Cell Titer Glo 2.0. luminescent assay. All experiments were performed in triplicate and were independently repeated at least 3 times.

RESULTS

We identified an activation state of U87MG cells after the plasma treatment. This activation state resulted in GBM cells sensitized to reactive species identified by decreased cell viability after treatment with H2O2 as compared to the H2O2 treatment alone (p< 0.005). In addition, the plasma-activated cells were sensitized to TMZ. Cells treated with CAP in combination with TMZ displayed decreased cell viability at TMZ concentrations of (10 uM) (p< 0.05) and (50 uM) (p< 0.005) as compared to TMZ alone.

CONCLUSIONS

This study demonstrates the activation phenomenon on GBM cells via direct CAP treatment. Due to this activation, the GBM cells were sensitized to both H2O2 and TMZ identified via decreased cell viability. Future work looks to assess this effect of cell activation/sensitization with chemotherapy plus radiation treatment.

Lhcx proteins provide photoprotection via thermal dissipation of absorbed light in the diatom Phaeodactylum tricornutum

Diatoms possess an impressive capacity for rapidly inducible thermal dissipation of excess absorbed energy (qE), provided by the xanthophyll diatoxanthin and Lhcx proteins. By knocking out the Lhcx1 and Lhcx2 genes individually in Phaeodactylum tricornutum strain 4 and complementing the knockout lines with different Lhcx proteins, multiple mutants with varying qE capacities are obtained, ranging from zero to high values. We demonstrate that qE is entirely dependent on the concerted action of diatoxanthin and Lhcx proteins, with Lhcx1, Lhcx2 and Lhcx3 having similar functions. Moreover, we establish a clear link between Lhcx1/2/3 mediated inducible thermal energy dissipation and a reduction in the functional absorption cross-section of photosystem II. This regulation of the functional absorption cross-section can be tuned by altered Lhcx protein expression in response to environmental conditions. Our results provide a holistic understanding of the rapidly inducible thermal energy dissipation process and its mechanistic implications in diatoms.

Photosynthetic organisms can dissipate excess absorbed light energy as heat to avoid photodamage. Here the authors show that induced thermal dissipation in the diatom Phaeodactylum tricornutum Pt4 is Lhcx protein-dependent and correlates with a reduced functional absorption cross-section of photosystem II.

Effectiveness of Positron Emission Tomography/Computed Tomography as a Guide for Palliative Radiation Therapy for Spinal Metastases

OBJECTIVE

As back pain is the presenting symptom in 95% of patients with epidural spinal metastases, appropriately identifying and treating the most symptomatic levels can provide significant palliation. The purpose of this study was to analyze the ability of combined positron emission tomography (PET)/computed tomography (CT) to identify spinal metastases with high metabolic activity and guide radiotherapy. We sought to correlate improvement in back pain with reduction in standard uptake value (SUV) after treatment.

METHODS

Retrospective review was performed of 72 patients with spinal metastases treated with stereotactic ablative radiation therapy at a single center between 2002 and 2014. PET/CT was used to calculate SUVs for spinal metastases, and treatment planning was based on PET/CT results. Preoperative and postoperative pain levels were assessed in all patients.

RESULTS

Reduction in pain scores was found in 78% of treated patients. A significant reduction in pain was identified in patients with >5 metastases compared with fewer lesions (P < 0.05). Degree of change in SUV did not correlate significantly with pain relief. However, comparing pretreatment and posttreatment PET/CT, patients with improved pain consistently displayed decreased SUV.

CONCLUSIONS

PET/CT was shown to be a useful adjunct in radiation treatment planning with change in SUV correlating with symptomatic improvement. This study paves the way for future prospective studies to further assess utility and cost-effectiveness of this imaging modality in radiation treatment planning for spinal metastases.

Temporary mechanical support of left ventricular failure following open heart surgery

Patients coming to open heart surgery with advanced cardiac dysfunction may require mechanical cardiac support to avoid life-threatening low cardiac output in the postoperative period. 15 patients who could not be withdrawn from cardiopulmonary bypass because of low cardiac output were supported with a left heart bypass system (left atrium to ascending aorta). Ten were ultimately separated from the device, 6 were dismissed from the hospital and 4 remain well (the longest 2.6 years postoperative). A major asset of the device is that thoracic reentry is not required when support is discontinued.

Effect of cold plasma on glial cell morphology studied by atomic force microscopy

The atomic force microscope (AFM) is broadly used to study the morphology of cells. The morphological characteristics and differences of the cell membrane between normal human astrocytes and glial tumor cells are not well explored. Following treatment with cold atmospheric plasma, evaluation of the selective effect of plasma on cell viability of tumor cells is poorly understood and requires further evaluation. Using AFM we imaged morphology of glial cells before and after cold atmospheric plasma treatment. To look more closely at the effect of plasma on cell membrane, high resolution imaging was used. We report the differences between normal human astrocytes and human glioblastoma cells by considering the membrane surface details. Our data, obtained for the first time on these cells using atomic force microscopy, argue for an architectural feature on the cell membrane, i.e. brush layers, different in normal human astrocytes as compared to glioblastoma cells. The brush layer disappears from the cell membrane surface of normal E6/E7 cells and is maintained in the glioblastoma U87 cells after plasma treatment.

The effect of tuning cold plasma composition on glioblastoma cell viability

Previous research in cold atmospheric plasma (CAP) and cancer cell interaction has repeatedly proven that the cold plasma induced cell death. It is postulated that the reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a major role in the CAP cancer therapy. In this paper, we seek to determine a mechanism of CAP therapy on glioblastoma cells (U87) through an understanding of the composition of the plasma, including treatment time, voltage, flow-rate and plasma-gas composition. In order to determine the threshold of plasma treatment on U87, normal human astrocytes (E6/E7) were used as the comparison cell line. Our data showed that the 30 sec plasma treatment caused 3-fold cell death in the U87 cells compared to the E6/E7 cells. All the other compositions of cold plasma were performed based on this result: plasma treatment time was maintained at 30 s per well while other plasma characteristics such as voltage, flow rate of source gas, and composition of source gas were changed one at a time to vary the intensity of the reactive species composition in the plasma jet, which may finally have various effect on cells reflected by cell viability. We defined a term “plasma dosage” to summarize the relationship of all the characteristics and cell viability.

A review of stereotactic radiosurgery practice in the management of skull base meningiomas

Gross total resection of skull base meningiomas poses a surgical challenge due to their proximity to neurovascular structures. Once the gold standard therapy for skull base meningiomas, microsurgery has been gradually replaced by or used in combination with stereotactic radiosurgery (SRS). This review surveys the safety and efficacy of SRS in the treatment of cranial base meningiomas including 36 articles from 1991 to 2010. SRS produces excellent tumor control with low morbidity rates compared with surgery alone for asymptomatic small skull base meningiomas, patients with risk factors precluding conventional surgery, and as adjuvant therapy for recurrent or residual lesions.

Kinetic analysis of anterior cervical discectomy and fusion supplemented with transarticular facet screws

OBJECT The clinical success rates of anterior cervical discectomy and fusion (ACDF) procedures are substantially reduced as more cervical levels are included in the fusion procedure. One method that has been proposed as an adjunctive technique for multilevel ACDF is the placement of screws across the facet joints ("transfacet screws"). However, the biomechanical stability imparted by transfacet screw placement (either unilaterally or bilaterally) has not been reported. Therefore, the purpose of this study was to determine the acute stability conferred by implementation of unilateral and bilateral transfacet screws to an ACDF construct. METHODS Eight C2-T1 fresh-frozen human cadaveric spines (3 female and 5 male; mean age 50 years) were tested. Three different instrumentation variants were performed on cadaveric cervical spines across C4-7: 1) ACDF with an intervertebral spacer and standard plate/screw instrumentation; 2) ACDF with an intervertebral spacer and standard plate/screw instrumentation with unilateral facet screw placement; and 3) ACDF with an intervertebral spacer and standard plate/screw instrumentation with bilateral facet screw placement. Kinetic ranges of motion in flexion-extension, lateral bending, and axial rotation at 1.5 Nm were captured after each of these procedures and were statistically analyzed for significance. RESULTS All 3 fixation scenarios produced statistically significant reductions (p < 0.05) in all 3 bending planes compared with the intact condition. The addition of a unilateral facet screw to the ACDF construct produced significant reductions at the C4-5 and C6-7 levels in lateral bending and axial rotation but not in flexion-extension motion. Bilateral facet screw fixation did not produce any statistically significant decreases in flexion-extension motion compared with unilateral facet screw fixation. However, in lateral bending, significant reductions at the C4-5 and C5-6 levels were observed with the addition of a second facet screw. The untreated, adjacent levels (C2-3, C3-4, and C7-1) did not demonstrate significant differences in range of motion. CONCLUSIONS The data demonstrated that adjunctive unilateral facet screw fixation to an ACDF construct provides significant gains in stability and should be considered a potential option for increasing the likelihood for obtaining a successful arthrodesis for multilevel ACDF procedures.

Observing signs of pain in relation to self-injurious behaviour among individuals with intellectual and developmental disabilities

BACKGROUND

Self-injurious behaviour is a chronic condition among people with intellectual and developmental disabilities for which there is no known cure. The pain hypothesis suggests that individuals who engage in self-injury have altered or diminished pain perception. The purpose of the present study was to assess how frequently individuals diagnosed with an intellectual and developmental disability who engage in chronic self-injury displayed non-verbal signs of pain in relation to their self-injury.

METHODS

We videotaped four participants (aged 28-50 years) in their homes during times when they were likely to engage in self-injury. Using continuous recording measures, we coded videotapes for the frequency and duration of self-injury and expressions of non-verbal pain-related behaviours. Sequential analyses were conducted to identify temporal relations between pain-related behaviours and self-injury.

RESULTS

Our data suggest that the existing measures of pain may be systematically related to instances of self-injury. The relationships, however, appear to vary depending on the person who engages in self-injury, the environmental contexts in which the self-injury occurs, and perhaps, the type of self-injury in which the person engages.

CONCLUSIONS

These results support some of the findings of Symons et al. and they raise questions about the blunted nociception hypothesis of self-injury.

How to dig deeper? Improved enrichment methods for mucin core-1 type glycopeptides

Two different workflows were tested in order to develop methods that provide deeper insight into the secreted O-glycoproteome. Bovine serum samples were subjected to lectin affinity-chromatography both at the protein- and peptide-level in order to selectively isolate glycopeptides with the most common, mucin core-1 sugar. This enrichment step was implemented with either protein-level mixed-bed ion-exchange chromatography or with peptide-level electrostatic repulsion hydrophilic interaction chromatography. Both methods led to at least 65% of the identified products being glycopeptides, in comparison to ≈ 25% without the additional chromatography steps [Darula, Z., and Medzihradszky, K. F. (2009) Affinity enrichment and characterization of mucin core-1 type glycopeptides from bovine serum. Mol. Cell. Proteomics 8, 2515-2526]. In order to improve not only the isolation but also the characterization of the glycopeptides exoglycosidases were used to eliminate carbohydrate extensions from the directly peptide-bound GalNAc units. Consequent tandem MS analysis of the mixtures using higher-energy collision-dissociation and electron-transfer dissociation led to the identification of 124 glycosylation sites in 51 proteins. While the electron-transfer dissociation data provided the bulk of the information for both modified sequence and modification site assignment, the higher-energy collision-dissociation data frequently yielded confirmation of the peptide identity, and revealed the presence of some core-2 or core-3 oligosaccharides. More than two-thirds of the sites as well as the proteins have never been reported modified.