Balancing Quality and Efficiency of Head and Neck Contour Revision for Online Adaptive Radiotherapy

PURPOSE/OBJECTIVE(S)

The number of target and organs-at-risk (OAR) structures requiring contours is a barrier to online adaptive radiotherapy (oART) implementation for head and neck (H&N) cancer. In sharing our experience utilizing a cone beam CT-based oART system featuring automatic contours, we analyzed the system's clinical performance and the dosimetric benefits of human supervision to investigate the optimal balance between contour editing and plan quality.

MATERIALS/METHODS

We analyzed 44 H&N patients and 349 adaptive fractions treated on the oART system. The unsupervised (automatically generated) and supervised (edited by clinicians) target and OAR contours as well as the corresponding adaptive plans were acquired. Dice Similarity Coefficient (DSC) and Hausdorff Distance (HD) used to assess the geometric extent of contour supervision. We mapped the clinically treated adaptive plan to the unsupervised contours to quantify the dosimetric effect of the contour edits, and the adaptive plan optimized from the unsupervised contours to the supervised contours to simulate an unsupervised workflow.

RESULTS

The targets were edited in >80.7% of the sessions, with the most changes seen in the primary GTV (DSC = 0.86 ± 0.09 and HD = 2.77 ± 1.58 mm) and the least in the nodal CTV (DSC = 0.92 ± 0.06, HD = 2.29 ± 1.49 mm). Among OARs, oral cavity was the most frequently edited (49.0%) and brainstem the least (2.2%). In general, OAR edits were minor (mean DSC > 0.95 with std Dosimetric quantification of the edits (Table 1) showed that while the unsupervised targets resulted in significant coverage loss, the change in unsupervised OAR dose was not as pronounced, with 81.5-96.8% still meeting the preplan constraints. Edits corresponding to major dose changes were mostly adjacent to or inside targets. The unsupervised workflow underdosed the targets and overdosed the OARs, and therefore is not recommended.

CONCLUSION

While target contours needed physician supervision in H&N oART, edits to automatic OAR contours were minor. An alternative contour workflow could be adopted to focus on the targets and reduce time spent on the OARs. For OAR close to or overlapping with the targets, strategic cropping could potentially minimize time for editing and improve the robustness of the adapted plan quality.

Disposable versus reusable fibre-optic nasendoscopes: a national survey of UK ENT surgical trainees and a single-centre cost-analysis

BACKGROUND

This study primarily assessed ENT surgical trainees' preferences for the qualities of disposable and reusable fibre-optic nasendoscopes. Secondary aims included eliciting trainees' views on ENT surgery and climate change, and creating a single-centre per-use cost analysis for disposable and reusable fibre-optic nasendoscopes.

METHODS

A cross-sectional study was formulated. An online survey consisting of multiple-choice and Likert-scale questions was distributed nationally. Cost analysis was performed using 2021-2022 data from the host institution.

RESULTS

Twenty-four trainees responded. Data on disposable fibre-optic nasendoscopes showed no difference in overall satisfaction (p = 0.244). Reusable fibre-optic nasendoscopes had a lower cost per use compared with disposable nasendoscopes at 5 years (4.7 per cent reduction) and 10 years (7.1 per cent reduction). Of the trainees, 79.2 per cent were supportive of climate-friendly initiatives within ENT surgery, and 25 per cent felt supported by their departments.

CONCLUSION

Trainees' satisfaction with disposable and reusable fibre-optic nasendoscopes is similar. Cost analysis favours reusable fibre-optic nasendoscopes in the long term at the host institution. Empowering departments and trainees to pursue climate-friendly initiatives should be encouraged.

Acute exacerbation of chronic obstructive pulmonary disease in a slaughterhouse

We describe the case of a 52-year-old male who presented with two episodes of acute exacerbations (AE) of chronic obstructive pulmonary disease (COPD) during work, while suspending live chickens for slaughter. The patient was exposed to high levels of bioaerosols, including endotoxins and microorganisms. Endotoxins can induce bronchoconstriction and airway inflammation, and COPD patients are more vulnerable to airway infections caused by microorganisms inhaled with bioaerosols. This study suggests that a high level of bioaerosols may induce airway infections, resulting in acute exacerbations of COPD.

Using the lactate-to-albumin ratio to predict mortality in patients with sepsis or septic shock: a systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate whether the lactate-to-albumin ratio (LAR) can predict mortality in patients with sepsis or septic shock.

PATIENTS AND METHODS

A systematic search of the PubMed, EMBASE, Web of Science, and Google Scholar databases was conducted on December 16, 2021, for relevant articles that provided the predictive performance of LAR for mortality in patients with sepsis or septic shock.

RESULTS

Eight studies encompassing a total of 4,723 patients were included in this paper. The pooled sensitivity, specificity, and diagnostic odds ratio of the LAR for predicting mortality were 0.71 (95% confidence interval [CI]: 0.54-0.84), 0.68 (95% CI: 0.58-0.76) and 5.23 (95% CI: 2.62-10.45), respectively. The area under the summary receiver operating characteristic curve was 0.74 (95% CI: 0.70-0.78).

CONCLUSIONS

The current evidence suggests that LAR is moderately predictive of mortality among patients with sepsis or septic shock and may be beneficial to identify high-risk patients.

225 First Contact: A Series of Zoom-Based, Virtual on Call Shifts

Aim

COVID-19 has resulted in reduced exposure to on-call shifts where medical students could increase confidence and proficiency in task prioritisation and decision making. Existing ‘simulated on-calls’ provide a substitute in a controlled environment, however in person teaching has also been limited by COVID-19. Our virtual on-call sessions use ZOOM to replicate the higher-level learning experiences normally conferred by live simulation.

Method

We designed a series of virtual ‘on-calls’ for medical students. Participants were ‘on-call’, receiving ‘bleeps’ which were ‘answered’ by calling a facilitator via ZOOM. The facilitator would roleplay a scenario and the ‘Electronic Patient Record’ (EPR) on Google Forms contained patient notes and observations. Students needed to collect information from the facilitator and document a management plan into the EPR. Participants received ‘bleeps’ of varying complexity, urgency and relevance and were expected to prioritise and triage tasks accordingly. Evaluation was via a pre/post session quiz with separate feedback forms.

Results

23 students from 18 universities participated. Students reported increased confidence in managing on-call scenarios, and average scores improved in the post session quiz. Positive feedback was paid to the variety of scenarios, the EPR system and the feeling of realism elicited from the need to triage and prioritise jobs.

Conclusions

Our framework uses readily accessible technology to provide interactive learning experience. Feedback suggested students engaged in higher order learning and thinking, achieving our stated aims. We aim to incorporate technologies such as automation software which will allow for a scalable, free, and accessible virtual on call.

1426 Assessing the Impact Of COVID-19 On ENT Referrals at A West London General Practice

Aim

The COVID-19 pandemic has resulted in initial GP consultations being conducted via telephone. This quality improvement initiative quantified this impact on ENT referrals conducted at a West London GP, using education to improve awareness of the relevant NICE guidance to reduce inappropriate referrals.

Method

An initial retrospective audit comparing number and urgency of ENT referrals and the appropriateness of ENT referrals (using NICE guidance) during the face to face (F2F) period (August 2019 – February 2020) and telephone period (March – September 2020) was performed. Results were presented locally to GPs, with education measures on relevant NICE guidance implemented. Further PDSA cycles occurred during October and November 2020.

Results

In total, 16 ENT referrals were made during the F2F period (routine n = 15; urgent n = 1); 3 were inappropriate. 31 referrals were made between March and September 2020 (routine n = 27, urgent n = 2, 2WW n = 2); 4 were inappropriate. Further cycles in October 2020, and November 2020 identified 13 referrals (routine n = 10, 2WW n = 3), and 2 referrals (routine n = 2) respectively. 1 inappropriate referral was made during October and none in November.

Conclusions

Locally, it appears that the number of routine referrals has increased since the advent of the initial lockdown. This may be partially explained by the practice losing the ability to perform some ENT services, such as ear wax micro-suctioning. Education to increase awareness of relevant guidance has been shown to reduce the number of inappropriate referrals to ENT services.

1372 Thrombocytosis and Malignancy: Management in Primary Care

Introduction

The diagnosis of cancer relies within primary care to recognise this possibility in patients. Studies have shown an association of thrombocytosis with cancer, in particular lung, renal, uterine and colorectal cancer. Subsequently, suspected cancer pathways incorporate thrombocytosis in stratifying risk. This quality improvement project aimed to evaluate and improve the approach of GPs at a West London practice in managing thrombocytosis.

Method

A retrospective study evaluated patients with a most recent platelet count of > 450x109/L. Furthermore, a survey was sent to all GPs within the practice to establish their understanding and concerns. Results were presented locally, and intervention applied following the end of the first cycle.

Results

The survey showed 75% (n = 9) of staff were aware of the association of thrombocytosis and malignancy. In absence of specific symptoms, 64% would consider a chest X-ray, 41% a faecal occult blood test and 16% would consider transvaginal USS in women. 28 patients were identified with thrombocytosis. Of these, 4 had underlying malignancy, 3 had an underlying haematological condition. 2 cases had a concurrent inflammatory process. Of the remaining 19 patients, 5 were referred on for specialist service. In the remaining 14, although filed as “to repeat blood test” or “speak to doctor”, 12 had yet to be actioned.

Conclusions

The management of thrombocytosis at a local level in primary care has room for improvement. An alert was designed and created on the online system used by the practice to safeguard missed recalls for blood tests and prompts to consider the possibility of malignancy.

1389 Axillary Staging in Ductal Carcinoma in Situ with Microinvasion: A Systematic Review

Introduction

Ductal carcinoma in situ with microinvasion (DCISM) is a rare subtype of DCIS, with a foci of tumour cells penetrating through the basement membrane. A conundrum for surgeons is that definitive diagnosis is made upon histological examination of the final specimen. In the UK, there are no specific guidelines on the role of axillary staging in the management of DCISM cases.

Method

A systematic review was conducted on the databases MEDLINE and Embase using the keywords: breast, DCISM, microinvasion, “ductal carcinoma in situ with microinvasion”, sentinel lymph node biopsy, SLNB, axillary staging was performed. 23 studies were selected for analysis. Primary outcome was the positivity of lymph node metastases; secondary outcome looked at characteristics of DCISM that may affect node positivity.

Results

2959 patients were included. Significant heterogeneity was observed amongst the studies with regards to metastases (I2=61%; P < 0.01). Lymph node macrometastases was estimated to be 2%. Significant subgroup difference was not observed between SLNB technique and lymph node macrometastases (Q = 0.74; p = 0.69). Statistical significance was observed between the focality of the DCISM and lymph node macrometastases (Q = 8.71; p = 0.033).

Conclusions

DCISM is not linked with higher rates of clinically significant metastasis to axillary lymph nodes. Survival rates are very similar to those seen in cases of DCIS. Current evidence suggests that axillary staging in cases of DCISM will not change their overall management. A conscientious multidisciplinary team approach evaluating pre-operative clinical and histological information to tailor the management specific to individual cases of DCISM would be a preferred approach than routine axillary staging.

Erratum: Azimuthal Anisotropy of K_{S}^{0} and Λ+Λ[over ¯] Production at Midrapidity from Au+Au Collisions at sqrt[s]_{NN}=130 GeV [Phys. Rev. Lett. 89, 132301 (2002)]

This corrects the article DOI: 10.1103/PhysRevLett.89.132301.

Erratum: Azimuthal Anisotropy at the Relativistic Heavy Ion Collider: The First and Fourth Harmonics [Phys. Rev. Lett. 92, 062301 (2004)]

This corrects the article DOI: 10.1103/PhysRevLett.92.062301.

P–370 RPL-protease A as a potential biomarker for predicting recurrent pregnancy loss

Study question

Could the reduction of RPL-protease A be involved in the dysfunctional trophoblast for resulting in recurrent pregnancy loss (RPL).

Summary answer

Low expression of RPL-protease A may result in RPL and low serum RPL-protease A level may be a potential biomarker for predicting RPL.

What is known already

The RPL-protease A is expressed and secreted by placenta. The RPL-protease A is involved in the pathogenesis of pre-eclampsia, and the serum RPL-protease A level is higher in the patients with pre-eclampsia than that of normal groups. In our previous study, we identified that the RPL-protease A mRNA level was lower in the villi of patients with RPL than that of normal groups.

Study design, size, duration

Using the CRISPR/Cas9 system, the RPL-protease A gene knockout BeWo cell (BeWo KO) line was established, and the wild type (BeWo WT) and BeWo KO cells were applied to investigate the roles of RPL-protease A in trophoblasts. The human serum RPL-protease A levels were investigated by Western blot analysis and ELISA kit.

Participants/materials, setting, methods

The cell-cell fusion, cell counting analysis, invasion and scratch wound assays, cell cycle analysis, and immunocytochemical analysis were used to investigate cellular functions of RPL-protease A in trophoblast. The sera were obtained from 32 normal pregnant women and 60 women with RPL. The Western blot analysis and ELISA were used for detection of serum RPL-protease A levels.

Main results and the role of chance

The β-hCG was detected in fused BeWo WT cells, while the BeWo KO cells cannot fuse and did not express the β-hCG. The ability of invasion was decreased, but the capacity of migration and proliferation was higher in BeWo KO cells than BeWo WT cells. Cell fusion related factor (β-hCG), and cell invasion related factors (MMP–2 and MMP–9) were highly expressed in BeWo WT cells, and cell related factor (FAK), and cell proliferation related factors (ERK, p38, JNK, MKK3, MKK6, Raf, and Ras) were highly expressed in BeWo KO cells. The Western blot analysis and ELISA indicate that the serum RPL-protease A level was decreased in patients with RPL compared to that of normal groups.

Limitations, reasons for caution

The results of this study have the limitation of RPL-protease A functions in vitro.

Wider implications of the findings: The cellular functions of RPL-protease A in trophoblasts were investigated to explain the pathogenesis of RPL, and low serum RPL-protease A level can be used for a potential biomarker predicting RPL.

Trial registration number

Not applicable

Determining the Degree of Dopaminergic Denervation Based on the Loss of Nigral Hyperintensity on SMWI in Parkinsonism

BACKGROUND AND PURPOSE

Nigrostriatal dopaminergic function in patients with Parkinson disease can be assessed using ¹²³I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropan dopamine transporter (¹²³I-FP-CIT) SPECT, and a good correlation has been demonstrated between nigral status on SWI and dopaminergic denervation on ¹²³I-FP-CIT SPECT. Here, we aim to correlate quantified dopamine transporter attenuation on ¹²³I-FP-CIT SPECT with nigrosome-1 status using susceptibility map-weighted imaging (SMWI).

MATERIALS AND METHODS

Between May 2017 and January 2018, consecutive patients with idiopathic Parkinson disease (n = 109) and control participants (n = 29) who underwent ¹²³I-FP-CIT SPECT with concurrent 3T SWI were included. SMWI was generated from SWI. Two neuroradiologists evaluated nigral hyperintensity from nigrosome-1 on each side of the substantia nigra. Using consensus reading, we compared the ¹²³I-FP-CIT-specific binding ratio according to nigral hyperintensity status and the ¹²³I-FP-CIT specific binding ratio threshold to confirm the loss of nigral hyperintensity was determined using receiver operating characteristic curve analysis.

RESULTS

The concordance rate between SMWI and ¹²³I-FP-CIT SPECT was 65.9%. The ¹²³I-FP-CIT-specific binding ratios in the striatum, caudate nucleus, and putamen were significantly lower when nigral hyperintensity in the ipsilateral substantia nigra was absent than when present (all, P < .001). The ¹²³I-FP-CIT-specific binding ratio threshold values for the determination of nigral hyperintensity loss were 2.56 in the striatum (area under the curve, 0.890), 3.07 in the caudate nucleus (0.830), and 2.36 in the putamen (0.887).

CONCLUSIONS

Nigral hyperintensity on SMWI showed high positive predictive value and low negative predictive value with dopaminergic degeneration on ¹²³I-FP-CIT SPECT. In patients with Parkinson disease, the loss of nigral hyperintensity is prominent in patients with lower striatal specific binding ratios.

MRI-Based Assessment of the Pharyngeal Constrictor Muscle as a Predictor of Surgical Margin after Transoral Robotic Surgery in HPV-Positive Tonsillar Cancer

BACKGROUND AND PURPOSE

Transoral robotic surgery is an emerging strategy for treating human papillomavirus-positive cancers, but the role of MR imaging in predicting the surgical outcome has not been established. We aimed to identify preoperative MR imaging characteristics that predispose the outcome of transoral robotic surgery toward an insecure (positive or close) surgical margin in human papillomavirus-positive tonsillar squamous cell carcinoma.

MATERIALS AND METHODS

Between December 2012 and May 2019, sixty-nine patients underwent transoral robotic surgery at our institution. Among these, 29 who were diagnosed with human papillomavirus-positive tonsillar squamous cell carcinoma, did not receive neoadjuvant treatment, underwent preoperative 3T MR imaging, and had postoperative pathologic reports and were included in this retrospective study. Two neuroradiologists evaluated the preoperative MR imaging scans to determine the tumor spread through the pharyngeal constrictor muscle using a 5-point scale: 1, normal constrictor; 2, bulging constrictor; 3, thinning constrictor; 4, obscured constrictor; and 5, tumor protrusion into the parapharyngeal fat. The risk of an insecure surgical margin (involved or <1 mm) according to the MR imaging scores was predicted using logistic regression with the Firth correction.

RESULTS

The interobserver agreement for the MR imaging scores was excellent (κ = 0.955, P < .001). A score of ≥4 could predict an insecure margin with 87.5% sensitivity and 92.3% specificity (area under the curve = 0.899) and was the only significant factor associated with an insecure margin in the multivariable analysis (OR, 6.59; 95% CI, 3.11-22.28; P < .001).

CONCLUSIONS

The pre-transoral robotic surgery MR imaging scoring system for the pharyngeal constrictor muscle is a promising predictor of the surgical margin in human papillomavirus-positive tonsillar squamous cell carcinoma.

Amalgam Strength Resistance to Various Contaminants

Purpose:

The purpose of this study was to quantify the relative strength tolerance of 1-day and 30-day amalgam following saturation contamination with water, saliva, blood, and handpiece lubricant oil during condensation.

Methods and Materials:

Valiant PhD XT amalgam was tested with 300 shear-strength (N=15) and 120 compressive-strength (N=6) specimens, divided into 1-day and 30-day groups, each with control, water, saliva, blood, and lubricant oil contamination samples. Shear specimens were condensed in 4 × 4-mm anchor wells inundated with contaminant fluids before adding a ring mold with 3.5-mm-diameter central hole adapted immediately to the top for continued condensation under contaminant-submerged conditions. Compressive specimen samples were condensed while completely inundated by each contaminant using the American Dental Association Specification No. 1 amalgam mold apparatus. All specimens were tested with the Instron E3000 and E10000 at 0.5 mm/min, with data statistically evaluated using the Kruskal-Wallis procedure with IBM SPSS v25 and Wilcoxon signed ranks test.

Results:

Shear test values (mean±SD) following intracapsular and extracapsular contamination after 30 days under 100% humidity at 37°C were as follows: control, 30.97±5.41 MPa; water, 30.63 ±4.41 MPa; saliva, 27.54 ±4.56 MPa; blood, 24.92 ±3.48 MPa; lubricant oil, 26.06 ±4.06 MPa. Compressive strengths (±SD) of similarly contaminated samples were as follows: control, 447.7 ±76.3 MPa; water, 343.6 ±70.1 MPa; saliva, 307.7 ±24.0 MPa; blood, 281.6 ±35.2 MPa; lubricant oil, 227.8 ±16.9 MPa.

Conclusions:

Saliva, blood, and handpiece oil diminish compressive strength significantly, but water shows no statistically significant effect (p&gt;0.05). Amalgam 30-day shear strength is significantly altered by contamination with water, blood, or handpiece lubricant oil (p&lt;0.05). Remaining amalgam strength after extensive contamination may still be clinically functional relative to a previous ADA recommendation and when compared with resin-based direct restorative materials.

Progression of Osteoporosis After Kidney Transplantation in Patients With End-Stage Renal Disease

BACKGROUND

This study investigated the prevalence of osteoporosis and the risk factors for its progression in kidney transplant recipients (KTRs).

METHODS

Dual energy X-ray absorptiometry was used to prospectively measure changes in bone mineral density (BMD) before kidney transplantation (KT) and 1 year after transplantation in 207 individuals. We also analyzed the risk factors of osteoporosis progression during this period.

RESULTS

Prior to KT, the mean BMD score (T-score of the femur neck area) was -2.1 ± 1.2, and the prevalence of osteoporosis was 41.5% (86/207). At 1 year post-transplantation, the mean BMD score significantly decreased to -2.3 ± 1.1 (P < .001), and the prevalence of osteoporosis increased to 47.3% (98/207; P = .277). The BMD score worsened over the study period in 69.1% (143/207) of patients, improved in 24.1% (50/207), and showed no change in 6.8% (14/207). Minimal intact parathyroid hormone (iPTH) improvement after KT was found to be an independent risk factor of osteoporosis progression.

CONCLUSIONS

This study demonstrates progressive loss of BMD after KT and sustained secondary hyperparathyroidism might influence the progression of osteoporosis.

Feasibility of Permanent Stenting with Solitaire FR as a Rescue Treatment for the Reperfusion of Acute Intracranial Artery Occlusion

BACKGROUND AND PURPOSE

The Solitaire FR can be used not only as a tool for mechanical thrombectomy but also as a detachable permanent stent. Our aim was to assess the feasibility and safety of permanent stent placement with the Solitaire FR compared with other self-expanding stents for intracranial artery recanalization for acute ischemic stroke.

MATERIALS AND METHODS

From January 2011 through January 2016, we retrospectively selected 2979 patients with acute ischemic stroke. Among them, 27 patients who underwent permanent stent placement (13 patients with the Solitaire FR [Solitaire group] and 14 patients with other self-expanding stents [other stent group]) were enrolled. The postprocedural modified TICI grade and angiographic and clinical outcomes were assessed. The safety and efficacy of permanent stent placement of the Solitaire FR for acute large-artery occlusion were evaluated.

RESULTS

Stent placement was successful in all cases. Modified TICI 2b-3 reperfusion was noted in 84.6% of the Solitaire group and in 78.6% of the other stent group. Procedural time was significantly shorter in the Solitaire group than in the other stent group (P = .022). Shorter procedural time was correlated with favorable outcome (ρ = 0.46, P = .035). No significant differences were found in the modified TICI grade, NIHSS score, mRS, and hemorrhagic transformation rate between the 2 groups. The acute in-stent thrombosis rate at discharge was significantly lower when a glycoprotein IIb/IIIa inhibitor was injected during the procedure (P = .013).

CONCLUSIONS

Permanent stent placement with the Solitaire FR compared with other self-expanding stents appears to be feasible and safe as a rescue tool for refractory intra-arterial therapy.

Diffusion-Weighted Imaging of the Head and Neck: Influence of Fat-Suppression Technique and Multishot 2D Navigated Interleaved Acquisitions

BACKGROUND AND PURPOSE

DWI of the head and neck can reveal valuable information, but the effects of fat suppression and multishot acquisition on image quality have not been thoroughly investigated. We aimed to comprehensively compare the quality of head and neck DWI at 3T using 2 fat-suppression techniques, STIR, and spectral presaturation with inversion recovery, which were used with both single- and multishot EPI.

MATERIALS AND METHODS

Sixty-five study participants underwent 3 DWI sequences of single-shot EPI-STIR, single-shot EPI-spectral presaturation with inversion recovery, and multishot EPI-spectral presaturation with inversion recovery of the head and neck. In multiple anatomic regions, 2 independent readers assessed 5-point visual scores for fat-suppression uniformity and image distortion, and 1 reader measured the contrast-to-noise ratio and ADC.

RESULTS

The mean visual score for fat-suppression uniformity was higher in single-shot EPI-STIR than in other sequences (all regions except for the orbital region, P < .05). The mean visual score for image distortion was higher in multishot EPI-spectral presaturation with inversion recovery than in single-shot EPI sequences (all regions, P < .001). Contrast-to-noise ratio was mostly lower in single-shot EPI-STIR than in other sequences (P < .001), and ADC was significantly higher in multishot EPI-spectral presaturation with inversion recovery than in single-shot EPI sequences (P ≤ .001).

CONCLUSIONS

Overall, multishot EPI-spectral presaturation with inversion recovery provided the best image quality, with relatively homogeneous fat suppression, less image distortion than single-shot EPI sequences, and higher contrast-to-noise ratio than single-shot EPI-STIR. The measured ADC values can be higher in multishot EPI-spectral presaturation with inversion recovery, which necessitates cautious application of the previously reported ADC values to clinical settings.

Probabilistic dietary exposure to ethyl carbamate from fermented foods and alcoholic beverages in the Korean population

The occurrence of ethyl carbamate was investigated in fermented foods and alcoholic beverages of the Korean total diet study. The concentrations of ethyl carbamate ranged from not detected to 166.5 μg kg^-1. Dietary exposure to ethyl carbamate was estimated by the probabilistic method. Estimated intakes of ethyl carbamate from foods and alcoholic beverages were 4.12 ng kg^-1 body weight (bw) per day for average consumers and 12.37 ng kg^-1 bw/day for 95th percentile high consumers. The major foods contributing to ethyl carbamate exposure were soy sauce (63%), followed by maesilju (plum liqueur, 30%), whisky (5%), and bokbunjaju (black raspberry wine, 2%). On the basis of the benchmark dose lower confidence limit 10% (BMDL₁₀) of 0.3 mg kg^-1 bw/day, margins of exposure were 128,000 for mean exposure and 40,000 for 95th percentile exposure. This indicates that the exposure of the Korean general population for ethyl carbamate is of low concern. However, careful vigilance should be continued for high consumers of fermented foods and alcoholic beverages.

Major Histocompatibilty Complex-Restricted Adaptive Immune Responses to CT26 Colon Cancer Cell Line in Mixed Allogeneic Chimera

BACKGROUND

Although the induction of mixed allogeneic chimera shows promising clinical tolerance results in organ transplantation, its clinical relevance as an anti-cancer therapy is yet unknown. We introduced a mixed allogenic chimera setting with the use of a murine colon cancer cell line, CT26, by performing double bone marrow transplantation.

METHODS

We analyzed donor- and recipient-restricted anti-cancer T-cell responses, and phenotypes of subpopulations of T cells. The protocol involves challenging 1 × 10⁵ cells of CT26 cells intra-hepatically on day 50 after bone marrow transplantation, and, by use of CT26 lysates and an H-2L^d-restricted AH1 pentamer, flow cytometric analysis was performed to detect the generation of cancer-specific CD4⁺ and CD8⁺ T cells at various time points.

RESULTS

We found that immunocompetence against tumors depends heavily on cancer-specific CD8⁺ T-cell responses in a major histocompatibility complex-restricted manner; the evidence was further supported by the increase of interferon-γ-secreting CD4⁺ T cells. Moreover, we demonstrated that during the effector immune response to CT26 cancer challenge, there was a presence of central memory cells (CD62L^hiCCR7⁺) as well as effector memory cells (CD62L^loCCR7^-). Moreover, mixed allogeneic chimeras (BALB/c to C56BL/6 or vice versa) showed similar or heightened immune responses to CT26 cells compared with that of wild-type mice.

CONCLUSIONS

Our results suggest that the responses of primary immunocompetency and of pre-existing memory T cells against allogeneic cancer are sustained and preserved long-term in a mixed allogeneic chimeric environment.

The Role of MRI in Diagnosing Neurovascular Compression of the Cochlear Nerve Resulting in Typewriter Tinnitus

BACKGROUND AND PURPOSE

Typewriter tinnitus, a symptom characterized by paroxysmal attacks of staccato sounds, has been thought to be caused by neurovascular compression of the cochlear nerve, but the correlation between radiologic evidence of neurovascular compression of the cochlear nerve and symptom presentation has not been thoroughly investigated. The purpose of this study was to examine whether radiologic evidence of neurovascular compression of the cochlear nerve is pathognomonic in typewriter tinnitus.

MATERIALS AND METHODS

Fifteen carbamazepine-responding patients with typewriter tinnitus and 8 control subjects were evaluated with a 3D T2-weighted volume isotropic turbo spin-echo acquisition sequence. Groups 1 (16 symptomatic sides), 2 (14 asymptomatic sides), and 3 (16 control sides) were compared with regard to the anatomic relation between the vascular loop and the internal auditory canal and the presence of neurovascular compression of the cochlear nerve with/without angulation/indentation.

RESULTS

The anatomic location of the vascular loop was not significantly different among the 3 groups (all, P > .05). Meanwhile, neurovascular compression of the cochlear nerve on MR imaging was significantly higher in group 1 than in group 3 (P = .032). However, considerable false-positive (no symptoms with neurovascular compression of the cochlear nerve on MR imaging) and false-negative (typewriter tinnitus without demonstrable neurovascular compression of the cochlear nerve) findings were also observed.

CONCLUSIONS

Neurovascular compression of the cochlear nerve was more frequently detected on the symptomatic side of patients with typewriter tinnitus compared with the asymptomatic side of these patients or on both sides of control subjects on MR imaging. However, considering false-positive and false-negative findings, meticulous history-taking and the response to the initial carbamazepine trial should be regarded as more reliable diagnostic clues than radiologic evidence of neurovascular compression of the cochlear nerve.

Positive correlation of serum HDL cholesterol with blood mercury concentration in metabolic syndrome Korean men (analysis of KNANES 2008-2010, 2013)

PURPOSE

High-density lipoprotein cholesterol (HDLC) is anti-inflammatory in the basal state and pro-inflammatory during the acute-phase response. Blood mercury also has an inflammatory property. Therefore, the aim of this study was to investigate the relationship between serum HDLC and blood mercury concentration in relation with metabolic syndrome (MS).

METHODS

The data of 7616 subjects (3713 men and 3903 women), over 20 years of age, from 2008 to 2013, Korea National Health and Nutrition Examination Survey were selected for cross-sectional analyses. Correlation and regression of serum HDLC and blood mercury were initially done. We compared serum HDLC concentration according to blood mercury quartile after adjustment for relevant variables in subjects with MS.

RESULTS

Mean blood mercury concentrations is 5.6 and 3.9 μg/dL in men and women, respectively. Blood mercury concentration in MS subjects was positively correlated with serum HDLC concentration, especially in men. In addition, HDLC concentration was significantly higher according to the higher blood mercury quartile.

CONCLUSION

Serum HDLC was positively associated with blood mercury concentration in MS Korean men. Therefore, elevated blood mercury may be a factor to increase serum HDLC concentration in MS men.

Evaluation of interface trap densities and quantum capacitance in carbon nanotube network thin-film transistors

The interface trap density in single-walled carbon nanotube (SWNT) network thin-film transistors (TFTs) is a fundamental and important parameter for assessing the electronic performance of TFTs. However, the number of studies on the extraction of interface trap densities, particularly in SWNT TFTs, has been insufficient. In this work, we propose an efficient technique for extracting the energy-dependent interface traps in SWNT TFTs. From the measured dispersive, frequency-dependent capacitance-voltage (C-V) characteristics, the dispersive-free, frequency-independent C-V curve was obtained, thus enabling the extraction and analysis of the interface trap density, which was found to be approximately 8.2 × 10(11) eV(-1) cm(-2) at the valence band edge. The frequency-independent C-V curve also allows further extraction of the quantum capacitance in the SWNT network without introducing any additional fitting process or parameters. We found that the extracted value of the quantum capacitance in SWNT networks is lower than the theoretical value in aligned SWNTs due to the cross point of SWNTs on the SWNT network. Therefore, the method proposed in this work indicates that the C-V measurement is a powerful tool for obtaining deep physical insights regarding the electrical performance of SWNT TFTs.

Human periodontal ligament stem cells suppress T-cell proliferation via down-regulation of non-classical major histocompatibility complex-like glycoprotein CD1b on dendritic cells

BACKGROUND AND OBJECTIVE

Periodontal ligament stem cells (PDLSCs) from the periodontal ligament tissue were recently identified as mesenchymal stem cells (MSCs). The capabilities of PDLSCs in periodontal tissue or bone regeneration have been reported, but their immunomodulatory role in T-cell immune responses via dendritic cells (DCs), known as the most potent antigen-presenting cell, has not been studied. The aim of this study is to understand the immunological function of homogeneous human STRO-1⁺ CD146⁺ PDLSCs in DC-mediated T-cell immune responses to modulate the periodontal disease process.

MATERIAL AND METHODS

We utilized highly purified (> 95%) human STRO-1⁺ CD146⁺ PDLSCs and human bone marrow mesenchymal stem cells (BMSCs). Each stem cell was co-cultured with human monocyte-derived DCs in the presence of lipopolysaccharide isolated from Porphyromonas gingivalis, a major pathogenic bacterium responsible for periodontal disease, in vitro to examine the immunological effect of each stem cell on DCs and DC-mediated T-cell proliferation.

RESULTS

We discovered that STRO-1⁺ CD146⁺ PDLSCs, as well as BMSCs, significantly decreased the level of non-classical major histocompatibility complex glycoprotein CD1b on DCs, resulting in defective T-cell proliferation, whereas most human leukocyte antigens and the co-stimulatory molecules CD80 and CD86 in/on DCs were not significantly affected by the presence of BMSCs or STRO-1⁺ CD146⁺ PDLSCs.

CONCLUSIONS

This study unveiled an immunomodulatory role of STRO-1⁺ CD146⁺ PDLSCs in negatively regulating DC-mediated T-cell immune responses, demonstrating their potential to be utilized in promising new stem cell therapies.

The Revascularization Scales Dilemma: Is It Right to Apply the Treatment in Cerebral Ischemia Scale in Posterior Circulation Stroke?

BACKGROUND AND PURPOSE

Although various revascularization scales are used in the angiographic evaluation of acute ischemic stroke, observer reliability tests of these scales have been rarely performed for posterior circulation stroke. We aimed to evaluate inter- and intraobserver variability of 2 scales, the modified Treatment in Cerebral Ischemia and the Arterial Occlusive Lesion, in posterior circulation stroke.

MATERIALS AND METHODS

Three independent readers interpreted pre- and postthrombolytic angiographies of 62 patients with posterior circulation stroke by using the modified Treatment in Cerebral Ischemia and Arterial Occlusive Lesion scales. The κ statistic was used to measure observer agreement for both scales, and κ > 0.6 was considered substantial agreement.

RESULTS

For the Arterial Occlusive Lesion scale, inter- and intraobserver agreement was >0.6. While intraobserver agreement of the modified Treatment in Cerebral Ischemia scale was >0.6 except for 1 reader, interobserver agreement was lower in dichotomized and original scales. In 49 cases with solely basilar artery occlusion, inter- and intraobserver agreement of both scales was similar to that in all 62 patients with posterior circulation stroke. In 2 consecutive readings, there was a significant decrease in the proportion of mTICI 2a reads (22.58% in the first versus 13.44% in the second session, P < .03) and a reciprocal increase in the sum of proportions for modified Treatment in Cerebral Ischemia 2b and modified Treatment in Cerebral Ischemia 3 reads (62.37% in the first versus 72.58% in the second session, P < .046).

CONCLUSIONS

In angiographic assessment of posterior circulation stroke, inter- and intraobserver agreement for the Arterial Occlusive Lesion scale was reliable, while the modified Treatment in Cerebral Ischemia failed to achieve substantial interobserver agreement. The clinical impact of this result needs to be validated in future studies.