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.

DIGITAL TECHNOLOGY USE AND SOCIAL CAPITAL: THE MODERATING EFFECT OF SOCIAL CLASS

This study aims to elucidate the heterogeneous associations between digital technology use and social capital by social class. The sample comprises 315 Korean older people who are 65 years old or older and participated in an online survey. Digital technology use was measured by the frequency of independent use in four areas of digital technology: primary, cultural, economic, and public areas. Social capital was measured with ten items asking the perceived support availability from both online and offline relationships. Social class was measured with education, household income, and subjective social position to reflect both objective and subjective aspects of social class. Using SPSS 25 PROCESS Macro 3.5, linear regression with moderation analyses was performed. A simple slope and the region of significance were tested for a significant interaction. Results showed that subjective social position significantly moderated the relationship between digital technology use and social capital. The positive association between digital technology use and social capital was strengthened when the level of subjective social position was higher. Education and household income did not moderate the relationship between digital technology use and social capital. The results of this study indicate that the effects of digital technology use vary depending on perceived aspects of social class. This study also demonstrates that people with higher social classes enjoy more benefits from digitalization, supporting digital inequality among the older population.

DIGITAL TECHNOLOGY USE AND INTERGENERATIONAL INTEGRATION: THE MEDIATING ROLE OF DIGITAL LITERACY

This study aimed to analyze the mediating effect of digital literacy on the association between digital technology use and intergenerational integration in later life. The sample included 315 older Korean adults aged 65 and above (M=68.83, SD=4.19, range=65-84) who participated in an online survey in December 2021. The participants’ use of digital technology was measured by the sum of thirteen questions about how often they used each digital technology in their daily lives. Intergenerational integration was measured by the sum of thirty questions concerning awareness of understanding and empathizing with characteristics and cultures between generations to live harmoniously in the times through communication and cooperation. The mediating variable, digital literacy, was measured by the sum of thirty-five questions from the New Media Literacy Scale, asking individuals’ ability to find, evaluate, and communicate information in a digital society. Age, gender, education level, household income, marital status, and living conditions were controlled for to reduce confounding effects. According to the mediation path analysis using SPSS PROCESS macro and bootstrapping, digital literacy significantly mediated the effects of digital technology use on intergenerational integration in later life; the higher the level of digital technology use, the higher the level of digital literacy, and this had a positive effect on the level of awareness of intergenerational integration among older adults. This study is significant in that it confirms the mechanism underlying the link between digital technology use and intergenerational integration and provides a new empirical model to promote intergenerational integration in terms of digital aging.

SERIAL MEDIATION BY DIGITAL ASSISTANCE, INTERNET SELF-EFFICACY, DIGITAL CITIZENSHIP, AND UNMET NEEDS

Although many social services are getting digitalized with the rapidly growing digital technology, there is little information available on the specific process of meeting personal needs in digital aging contexts. The present study examined the serial mediation model from digital assistant to unmet needs via internet self-efficacy and digital citizenship. An online survey was used to collect data in December 2021, and the sample included 223 older Korean adults aged 65 and above (M=68.79, SD=4.18, range=65-84) who owned at least one digital device. Unmet needs, the dependent variable, was the number of problems (e.g., housing, physical functioning) that participants responded to as ‘unmet.’ The independent variable was digital assistance, meaning getting help from friends or others when having problems with the digital device. The first mediator was internet self-efficacy, and the second mediator was five subtypes of digital citizenship (internet political activism, technical skills, local/global awareness, critical perspective, and networking agency). Covariates were gender, age, education, and income. SPSS Process Macro was utilized for serial mediation analysis. The result showed that only a serial mediation path from digital assistance to unmet needs via internet self-efficacy and internet political activism was significant. Additionally, a simple mediation path from digital assistance to unmet needs via internet political activism was significant. Technical skills, local/global awareness, critical perspective, and networking agency did not reveal significant mediational paths. Findings imply providing digital assistance system may be useful to reduce unmet needs among older adults by enhancing self-efficacy and political participation in the current digitalized world.

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

Social Exclusion and Suicidal Ideation: Analysis of the Bereaved Living Alone

The aim of this study is to explore the relationship between social exclusion and suicidal ideation among bereaved older people living alone. When people with a significant loss in the familial relationship are exposed to social exclusion, they likely experience poor mental health and suicidal ideation. Using the Korean Community Health Survey 2017, logistic regression model was applied to the bereaved older people living alone, 65 to 110 of age (N=14,659). Social exclusion was comprised of three network-based components: exclusion from relationships, social participation, and community. Relationship exclusion means the lack of contact with family, friends, and neighbors, respectively, at least once a week. Social participation exclusion refers to the lack of participation in a religious, socializing, and leisure activity, respectively, at least once a month. Community exclusion covers two indicators of trust in neighbors and perception of neighborhood reciprocity. Results showed that indicators of relationship, social participation, and community exclusion were associated with suicidal ideation. Bereaved, living-alone older people were likely to have suicidal ideation when they lack contact with neighbors (OR=1.13, p<.05), participation in the religious activity (OR=1.12, p<.05) and socializing activity (OR=1.20, p<.05), and trust in neighbors (OR=1.29, p<.001). The moderation analysis showed that exclusion from socializing activity was associated with suicidal ideation only among females. The results of the analyses imply that interventions that promote social participation could improve the mental health of the bereaved older adults living alone.

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.

The originating pattern of deep inferior epigastric artery: anatomical study and surgical considerations

PURPOSE

Studies focusing on the originating patterns of the deep inferior epigastric artery (DIEA) have not been conducted. Here, we analyzed the vascular anatomy of the DIEA with computed tomographic angiography (CTA) to provide assistance during proximal pedicle dissection of a DIEA-based flap.

METHODS

We conducted a retrospective study on patients who had undergone breast reconstruction with the transverse rectus abdominis musculocutaneous flap and the deep inferior epigastric perforator flap from March 2006 to October 2016. Preoperative three-dimensional computed tomographic angiograms of the abdominal wall (hemi-abdominal walls) were employed in this study, and three independent surgeons reviewed all CTA images. The originating angles and the distance from the originating point to the DIEA turning point were analyzed. Moreover, we assessed the relationship between the measured values and patients' characteristics, such as abdominal surgery history.

RESULTS

CTA data of 184 patients and 368 hemiabdomens were reviewed and analyzed. Most of the DIEAs originated from the external iliac artery in the medial direction, proceeded caudally, and curved in a cephalic direction. The average descending length was 11.29 mm. As the DIEA origin angle decreased (toward the caudal direction), the distance of the initial descent increased (r = 0.382, p < 0.01). In addition, the descending length was significantly larger (p < 0.01) in the operation group (12.22 mm) than in the non-operation group (9.86 mm).

CONCLUSIONS

Surgeons should consider DIEA-originating patterns to ensure safe pedicle dissection during flap elevation.

Quantitative analysis of shoulder function and strength after breast reconstruction: A retrospective cohort study

Immediate breast reconstruction (IBR) after mastectomy has been proven to affect patient quality of life, psychological well-being, and functional capacities. In the present study, we aimed to investigate the effect of breast reconstruction on postoperative shoulder function and muscle performance by evaluating isokinetic muscle performance tests.A retrospective chart review to collect data on shoulder function analysis with isokinetic muscle performance testing was performed among patients who received mastectomy with IBR from July 2013 to March 2015. Patients were categorized into 4 groups: a control group that underwent mastectomy without reconstruction, a tissue expander/implant insertion group, a pedicled latissimus dorsi (LD) flap group, and a free transverse rectus abdominis muscle (TRAM) flap group.Analysis of the groups at 1 to 3, 4 to 6, 7 to 9, 10 to 12, and 13 to 15 months postoperatively showed significant shoulder function improvement in the tissue expander/implant and TRAM groups as measured by linear regression analysis. Compared with the control group, patients who received immediate reconstruction with tissue expander/implant insertion or a TRAM flap showed statistically significant improvement in shoulder function after mastectomy.IBR with a TRAM flap or tissue expander/implant insertion were more beneficial for shoulder rehabilitation and for regaining function compared to mastectomy alone and breast reconstruction with a LD flap.

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.

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.

Coxsackievirus and Adenovirus Receptor, a Tight Junction Protein, in Peri-Implantation Mouse Embryos

To understand the role of Coxsackievirus and adenovirus receptor (CAR), a tight junction (TJ) protein, in peri-implantation embryos, developmental expression of CAR and its role in paracellular permeability were examined in mouse embryos. Splice variants for transmembrane CAR, Car1, Car2, and Car3 mRNA, were expressed from 2-cell, morula, and blastocyst stages onward, respectively, whereas mRNA for soluble CAR was expressed in MII oocytes and 4-cell stage onward. On Western blot, ∼46 kDa CAR proteins were detected in blastocysts. During the 4-cell embryos to morula stage, CAR was gradually concentrated at the contacts between blastomeres. In blastocysts, CAR was expressed at the cell contacts within the inner cell mass as well as in the trophectoderm (TE) where CAR was found together with ZO1 at the apical contacts, suggesting that CAR builds up apical TJs in TE and mediates cell adhesion in TE and inner cell mass. In blastocysts, CAR-blocking antibodies under Ca(2+) switching increased the dextran permeability and decreased the volume of blastocoel and H19 and Cdx2 mRNA, suggesting the pivotal role of CAR in the blastocyst development and paracellular permeability barrier in TE. CAR was expressed in TE of implanting embryos as well as endometrial epithelium, suggesting the involvement of CAR in the interaction between implanting embryos and endometrium. At 5-6 days postcoitum, CAR was expressed together with ZO1 in the primitive endoderm, visceral endoderm, and epiblasts facing the pro-amniotic cavity, suggesting that CAR TJs contribute to the separation of epiblast from the blastocoel and development of the pro-amniotic cavity within epiblasts.

Rapid Detection of Glycogen Synthase Kinase-3 Activity in Mouse Sperm Using Fluorescent Gel Shift Electrophoresis

Assaying the glycogen synthase kinase-3 (GSK3) activity in sperm is of great importance because it is closely implicated in sperm motility and male infertility. While a number of studies on GSK3 activity have relied on labor-intensive immunoblotting to identify phosphorylated GSK3, here we report the simple and rapid detection of GSK3 activity in mouse sperm using conventional agarose gel electrophoresis and a fluorescent peptide substrate. When a dye-tethered and prephosphorylated (primed) peptide substrate for GSK3 was employed, a distinct mobility shift in the fluorescent bands on the agarose was observed by GSK3-induced phosphorylation of the primed peptides. The GSK3 activity in mouse testes and sperm were quantifiable by gel shift assay with low sample consumption and were significantly correlated with the expression levels of GSK3 and p-GSK3. We suggest that our assay can be used for reliable and rapid detection of GSK3 activity in cells and tissue extracts.

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.