Tumor-Informed Circulating Tumor DNA for Minimal Residual Disease Detection in the Management of Colorectal Cancer

PURPOSE

Recurrence after curative-intent treatment occurs in 20%-50% of patients with stage II-IV colorectal cancer (CRC), underscoring the need for early detection of minimal residual disease (MRD) using circulating tumor DNA (ctDNA). Here, we examined the pattern of use of a tumor-informed ctDNA assay in CRC MRD monitoring in routine clinical practice at Mayo Clinic, Rochester.

METHODS

We conducted a retrospective analysis of health records of patients with CRC who had at least one tumor-informed ctDNA assay from May 2019 through July 1, 2022. Recurrence was defined as radiographic evidence of disease. Descriptive characteristics of the cohort, ctDNA results, and subsequent interventions were recorded.

RESULTS

Of the 120 patients included, the median age at diagnosis was 67 years, 46% were female, and 94% were White. At diagnosis, 10 patients had stage I, 23 stage II, 60 stage III, and 25 stage IV disease. Of 476 ctDNA assays performed, 70% were performed in patients who had recurrent disease most commonly to monitor the effectiveness of therapeutic interventions and 16% resulted in a change in clinical decision making. There were 110 recurrences identified in 62 patients, as some patients experienced more than one recurrence over time. Compared with serum carcinoembryonic antigen levels, ctDNA results correlated better with radiologic imaging.

CONCLUSION

Routine ctDNA monitoring for MRD detection has been adopted in clinical practice; however, 84% of ctDNA assays performed did not result in a change in clinical management. This suggests the need for further clinical research data to guide routine clinical use of ctDNA MRD testing in CRC.

Postpartum related intrahepatic cholangiocarcinoma with FGFR2 fusion and severe hyperbilirubinemia with response to FGFR inhibitor pemigatinib: case report and review

Background

Cholangiocarcinoma during postpartum or pregnancy is a rare presentation. There are limited cases reported in the literature. Diagnosis can be delayed as presenting signs and symptoms may be attributed to pregnancy or postpartum state.

Case Description

We present the case of a 33-year-old postpartum woman with intrahepatic cholangiocarcinoma with severe hyperbilirubinemia who was found to have fibroblast growth factor receptor 2 (FGFR2)-adenosylhomocysteinase like 1 (AHCYL1) fusion on next-generation sequencing (NGS). She initially was treated with two doses of gemcitabine and cisplatin with increasing hyperbilirubinemia requiring hold of further chemotherapy. NGS showed FGFR2-AHCYL1 fusion, and she was started on the FGFR inhibitor pemigatinib, with dramatically decreasing bilirubin within 10 days. She eventually normalized her bilirubin values and had partial response on follow-up imaging.

Conclusions

This is the first report, to our knowledge of response to an FGFR inhibitor in the postpartum setting, as well to show response in the setting of life-threatening hyperbilirubinemia. Our patient did not tolerate standard chemotherapy, likely due to liver dysfunction, but responded to pemigatinib, suggesting that the liver dysfunction was driven by her disease. This case underscores the need to include NGS as part of initial workup to identify important therapeutic targets and increase available lines of therapy, including those patients who are postpartum or pregnant.

Genetic and Survey Data Improves Performance of Machine Learning Model for Long COVID

Over 200 million SARS-CoV-2 patients have or will develop persistent symptoms (long COVID). Given this pressing research priority, the National COVID Cohort Collaborative (N3C) developed a machine learning model using only electronic health record data to identify potential patients with long COVID. We hypothesized that additional data from health surveys, mobile devices, and genotypes could improve prediction ability. In a cohort of SARS-CoV-2 infected individuals (n=17,755) in the All of Us program, we applied and expanded upon the N3C long COVID prediction model, testing machine learning infrastructures, assessing model performance, and identifying factors that contributed most to the prediction models. For the survey/mobile device information and genetic data, extreme gradient boosting and a convolutional neural network delivered the best performance for predicting long COVID, respectively. Combined survey, genetic, and mobile data increased specificity and the Area Under Curve the Receiver Operating Characteristic score versus the original N3C model.

Impact of perioperative chemotherapy on survival in patients with cholangiocarcinoma undergoing curative resection

BACKGROUND

Most patients with localized cholangiocarcinoma (CCA) endure cancer relapse after curative resection underscoring the importance of systemic therapy. The current study attempts to determine the impact of perioperative chemotherapy (PC) on survival in patients with CCA undergoing resection.

METHODS

Patients diagnosed with CCA undergoing curative-intent resection between January 1, 2000, and December 31, 2019, in a tertiary care center were included. Cox proportional hazard modeling was used to determine the impact of PC on disease-free survival (DFS) and overall survival (OS). In addition, a nomogram was constructed to estimate 3-year DFS.

RESULTS

Among the 182 patients included in the analysis, 102 underwent surgery alone, and 80 received surgery plus PC. Forty-two patients received neoadjuvant therapy, and 38 patients received adjuvant therapy. On multivariate analysis, PC was significantly associated with an improved DFS (HR, 95% CI: 0.63, 0.41-0.98; p = 0.04) and OS (HR, 95% CI: 0.46, 0.27-0.78; p < 0.01). In the interaction analysis, the survival benefit was especially seen in patients with positive resection margins and tumor size > 5 cm.

CONCLUSION

In patients with CCA undergoing curative resection, receipt of PC was associated with improved DFS and OS. The nomogram constructed from this database provides an estimate of 3-year DFS after surgical resection. Randomized trials are needed to define the optimal regimen and sequence.

Preliminary experience with robotic cholecystectomy illustrates feasibility in a canine cadaver model

OBJECTIVE

To evaluate the feasibility and describe the relevant differences between robotic cholecystectomy (RC) and laparoscopic cholecystectomy in a canine model.

SAMPLE

Canine cadavers (n = 4) weighing between 30 and 42 kg.

METHODS

Dogs were positioned in dorsal recumbency. A surgical robot was used to perform the RC and was placed at the cranial aspect of the surgical table. One 12-mm and 3 8-mm robotic ports and 1 5-mm laparoscopic port were placed as needed to perform the RC. The specific steps of the procedure were described and timed. Perceived differences between psychomotor skills between robotics and laparoscopy were noted.

RESULTS

RC was successful in all dogs, but minor intraoperative complications did occur during the manipulation of the gallbladder in 1 dog. The median length of time for ports to be appropriately docked was 19.5 minutes, and the median procedure time was 119.5 minutes. Psychomotor skills specific to robotics can be learned during this procedure.

CLINICAL RELEVANCE

Robotic cholecystectomy is feasible. RC allowed for experience with the different psychomotor skills utilized with robotic instrumentation and may be an appropriate training procedure for veterinary surgeons wishing to gain basic experience with robotic instrumentation.

Episodic stuttering as the presenting manifestation of acute ischemic stroke: A case report and systematic literature review

BACKGROUND

Acquired episodic stuttering in adulthood represents a rare condition, which has been infrequently described in the literature.

CASE PRESENTATION

We describe the case of a 62-year-old male who presented to the emergency room with three episodes of new-onset brief isolated stuttering with no other speech impairment or associated focal neurologic deficits. His brain magnetic resonance imaging was notable for the presence of a small acute ischemic stroke involving the left precuneus cortex.

SYSTEMATIC LITERATURE REVIEW

We performed a systematic literature review to evaluate the association between stroke and acquired neurogenic stuttering. The evidence published to this date suggests that the underlying pathophysiology of acquired stutter does not localize to an isolated or focal region. The development of stuttering secondary to strokes may be the result of a disruption at any level in a cortico-striato-cortical integrative pathway mediating speech execution.

CONCLUSION

Here we aimed to emphasize the importance of carefully evaluating new-onset recurrent episodic stuttering to rule out an underlying stroke or another neurogenic etiology. We provide a comprehensive review of acquired stuttering, its differential diagnosis, and its evaluation.

Distinguishing skill levels with haptic simulation in restorative dentistry: Myth or reality?

INTRODUCTION

This study aims to validate that haptic simulator assistance could distinguish skill levels with haptic simulation in restorative dentistry.

MATERIALS AND METHODS

This work was carried out with 93 first-year, 87 third-year and 44 fifth-year dental students. The promotions of first- and fifth-year dental students made one session to represent the negative and the positive controls, respectively. The third-year dental students were the studied population. Whatever the group, the maximum time for each reparation was restricted to 3 min. All students have to perform the same three exercises. The third-year dental students performed four sessions spread over the whole university year. For each test, the total score provided by the simulator was recorded and analysed.

RESULTS

The exercises are not discriminating in direct vision while the exercise in indirect vision is very interesting to distinguish the levels of the learners.

CONCLUSION

The results underline that the exercises in indirect vision could distinguish different profiles of student having different preclinical and clinical levels, while making it possible to follow the acquisition of clinical competence.

Genomics driven precision oncology in advanced biliary tract cancer improves survival

BACKGROUND

Biliary tract cancers (BTCs) including intrahepatic, perihilar, and distal cholangiocarcinoma as well as gallbladder cancer, are rare but aggressive malignancies with few effective standard of care therapies.

METHODS

We implemented integrative clinical sequencing of advanced BTC tumors from 124 consecutive patients who progressed on standard therapies (N=92 with MI-ONCOSEQ and N=32 with commercial gene panels) enrolled between 2011-2020.

RESULTS

Genomic profiling of paired tumor and normal DNA and tumor transcriptome (RNA) sequencing identified actionable somatic and germline genomic alterations in 54 patients (43.5%), and potentially actionable alterations in 79 (63.7%) of the cohort. Of these, patients who received matched targeted therapy (22; 40.7%) had a median overall survival of 28.1 months compared to 13.3 months in those who did not receive matched targeted therapy (32; P < 0.01), or 13.9 months in those without actionable mutations (70; P < 0.01). Additionally, we discovered recurrent activating mutations in FGFR2, and a novel association between KRAS and BRAF mutant tumors with high expression of immune modulatory protein NT5E (CD73) that may represent novel therapeutic avenues.

CONCLUSIONS

Overall, the identification of actionable/ potentially actionable aberrations in a large proportion of cases, and improvement in survival with precision oncology supports molecular analysis and clinical sequencing for all patients with advanced BTC.

Safety and immunogenicity of a ChAdOx1 vaccine against Rift Valley fever in UK adults: an open-label, non-randomised, first-in-human phase 1 clinical trial

BACKGROUND

Rift Valley fever is a viral epidemic illness prevalent in Africa that can be fatal or result in debilitating sequelae in humans. No vaccines are available for human use. We aimed to evaluate the safety and immunogenicity of a non-replicating simian adenovirus-vectored Rift Valley fever (ChAdOx1 RVF) vaccine in humans.

METHODS

We conducted a phase 1, first-in-human, open-label, dose-escalation trial in healthy adults aged 18-50 years at the Centre for Clinical Vaccinology and Tropical Medicine, Oxford, UK. Participants were required to have no serious comorbidities or previous history of receiving an adenovirus-based vaccine before enrolment. Participants were non-randomly allocated to receive a single ChAdOx1 RVF dose of either 5 × 109 virus particles (vp), 2·5 × 1010 vp, or 5 × 1010 vp administered intramuscularly into the deltoid of their non-dominant arm; enrolment was sequential and administration was staggered to allow for safety to be assessed before progression to the next dose. Primary outcome measures were assessment of adverse events and secondary outcome measures were Rift Valley fever neutralising antibody titres, Rift Valley fever GnGc-binding antibody titres (ELISA), and cellular response (ELISpot), analysed in all participants who received a vaccine. This trial is registered with ClinicalTrials.gov (NCT04754776).

FINDINGS

Between June 11, 2021, and Jan 13, 2022, 15 volunteers received a single dose of either 5 × 109 vp (n=3), 2·5 × 1010 vp (n=6), or 5 × 1010 vp (n=6) ChAdOx1 RVF. Nine participants were female and six were male. 14 (93%) of 15 participants reported solicited local adverse reactions; injection-site pain was the most frequent (13 [87%] of 15). Ten (67%) of 15 participants (from the 2·5 × 1010 vp and 5 × 1010 vp groups only) reported systemic symptoms, which were mostly mild in intensity, the most common being headache (nine [60%] of 15) and fatigue (seven [47%]). All unsolicited adverse events reported within 28 days were either mild or moderate in severity; gastrointestinal symptoms were the most common reaction (at least possibly related to vaccination), occurring in four (27%) of 15 participants. Transient decreases in total white cell, lymphocyte, or neutrophil counts occurred at day 2 in some participants in the intermediate-dose and high-dose groups. Lymphopenia graded as severe occurred in two participants in the 5 × 1010 vp group at a single timepoint, but resolved at the subsequent follow-up visit. No serious adverse events occurred. Rift Valley fever neutralising antibodies were detectable across all dose groups, with all participants in the 5 × 1010 vp dose group having high neutralising antibody titres that peaked at day 28 after vaccination and persisted through the 3-month follow-up. High titres of binding IgG targeting Gc glycoprotein were detected whereas those targeting Gn were comparatively low. IFNγ cellular responses against Rift Valley fever Gn and Gc glycoproteins were observed in all participants except one in the 5 × 1010 vp dose group. These IFNγ responses peaked at 2 weeks after vaccination, were highest in the 5 × 1010 vp dose group, and tended to be more frequent against the Gn glycoprotein.

INTERPRETATION

ChAdOx1 RVF was safe, well tolerated, and immunogenic when administered as a single dose in this study population. The data support further clinical development of ChAdOx1 RVF for human use.

FUNDING

UK Department of Health and Social Care through the UK Vaccines Network, Oak Foundation, and the Wellcome Trust.

TRANSLATION

For the Swahili translation of the abstract see Supplementary Materials section.

A Unicorn Disease: The Large Duct Variant of Invasive Ductal Adenocarcinoma of the Pancreas

Large duct adenocarcinoma (LDA) is a rare histopathological variant of pancreatic ductal adenocarcinoma (PDAC) that closely mimics intraductal papillary mucinous neoplasm (IPMN). We present a 74-year-old female diagnosed with LDA in 2017. She was initially managed with chemotherapy and laparoscopic distal pancreatectomy. After five years of stable disease on systemic chemotherapy, she was referred to us to explore further definitive treatments. We used a multidisciplinary approach with curative-intent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC), followed by oral maintenance chemotherapy. Subsequent scans showed stable disease; she eventually underwent neoadjuvant radiation and surgery with intraoperative radiation therapy (IORT) and achieved remission.

Parent Behavior Management Training for Child ADHD Enhanced to Address Health Behaviors: Comparison of Telemedicine "Telegroup" Versus In-Person Delivery

OBJECTIVE

ADHD is associated with suboptimal health behaviors including physical activity (PA). LEAP is a parent BMT group program enhanced to focus on health behaviors, integrated with mHealth technology. Little is known about implementing BMT via telemedicine "telegroups."

METHODS

Children ages 5 to 10 with ADHD and their caregiver wore activity trackers and participated in an 8 to 9 week parent BMT and social media group emphasizing PA, sleep, and screen use. A 7-day child accelerometer-wear and parent and teacher measures were completed pre- and post-group. Groups were in-person prior to the COVID-19 pandemic and in telegroup format during the pandemic.

RESULTS

Thirty-three families participated in person and 23 participated via virtual telegroup. Group attendance was superior for telegroup with equivalent satisfaction and skill use. Changes in health behavior and clinical outcomes were equivalent.

CONCLUSIONS

LEAP is a feasible and novel BMT intervention that can be delivered in an accessible telegroup format with high participation and acceptability.

Transfer function approach to understanding periodic forcing of signal transduction networks

Signal transduction networks are responsible for transferring information from the extracellular to the intracellular environment. This process facilitates biochemical changes in the cell which, in turn, dictates physiological changes such as differentiation and growth. Information can be stored in a variety of physical modes, including signal frequency. Different signal frequencies impart different information onto the cell surface, driving different physiological outcomes via signal transduction networks. Frequency-dependent cell behaviour is well documented in experimental literature. Understanding this frequency dependence allows us to control cells, opening avenues into therapeutics and bridges between theory and experiment. The transfer function provides one approach to understanding this. In this tutorial, we show how to obtain the transfer function of an arbitrary signal transduction network and use it to explain how the network responds to periodic forcing. We discuss advantages and limitations to this method.

Pembrolizumab near the end of life in patients with metastatic pancreatic cancer: a multi-site consecutive series to examine survival and patient treatment burden

BACKGROUND

Pembrolizumab confers minimal benefit to most patients with pancreas cancer. We explored survival and patient treatment burden (for example, death within 14 days of therapy) in a subgroup who had early access to pembrolizumab .

METHODS

This multisite study examined consecutive pancreas cancer patients, who received pembrolizumab from 2004 through 2022. Median overall survival of > 4 months was to be deemed favorable. Patient treatment burden and medical record quotations are presented descriptively.

RESULTS

Forty-one patients (median age 66 years; range 36, 84) are included. Fifteen (37%) had dMMR, MSI-H, TMB-H, or Lynch syndrome; and 23 (56%) received concurrent therapy. The median overall survival was 7.2 months (95% confidence interval (CI): 5.2, 12.7 months); 29 were deceased at the time of reporting. Patients with dMMR, MSI-H, TMB-H, or Lynch syndrome had a lower risk of death: hazard ratio (HR): 0.29 (95% CI: 0.12, 0.72); p = 0.008. Medical record phrases ("brilliant response") aligned with the above. One patient died within 14 days of therapy, and one was in an intensive care unit within 30 days of death. Fifteen patients enrolled in hospice; four of these died < 3 days later.

CONCLUSIONS

These unexpectedly favorable findings underscore the need for healthcare providers-including palliative care providers-to knowledgeably guide patients about cancer therapy even near the end of life.

Impact of Simulation-Based Training on Radiation Exposure of Young Interventional Cardiologists

Reducing radiation exposure during cardiovascular catheterization is of paramount importance to ensure patient and staff safety. Our study aimed to assess the transferability of acquired skills from virtual reality to the real world, including radioprotection measures during mentored simulation training (ST) in coronary angiography. A total of 10 cardiology residents were evaluated during real-life cases in the catheterization laboratory before (group A) and after mentored ST. The educational effect of mentored simulator training on real-life case performance was evaluated at 2 different time points: within the first week (group B) and after 12 weeks (group C). Compared with group A, the total dose area product (DAP) (µGy•m²) and total air kerma (mGy) were lower after ST: group A: 2,633 (1,723 to 3,617) versus group B: 1,618 (1,032 to 2,562), p <0.05 and 214 (136 to 297) versus 135 (84 to 222), p <0.05, respectively. Concerning operator radiation exposure (µSv), left finger dose: 1,090 (820 to 1,460) versus 635 (300 to 900), p = 0.028; left leg dose 80 (0 to 110) versus 0 (0 to 0), p = 0.027; left eye lens dose: 39 (24 to 69) versus 11 (8 to 20), p <0.0001; and chest dose outside the lead apron: 50 (34 to 88) versus 29 (21 to 50), p <0.003 were significantly lower in the group B than group A. A total of 12 weeks after ST, the total DAP and total air kerma remained stable along with operator exposure except left eye lens dose (µSv): group B: 11 (8 to 20) versus group C: 16 (12 to 27), p = 0.02. In addition, left eye lens dose, left wrist dose, and chest dose outside the lead apron were significantly correlated with total DAP (rs = 0.635, rs = 0.729, and rs = 0, 629, respectively) and total air kerma (rs = 0.488, rs = 0.514, and rs = 0.548, respectively) at 12 weeks. In conclusion, ST for coronary angiography may improve radioprotection learning and should be incorporated into training curricula.

Sexual Behaviors Associated with HIV Transmission Among Transgender and Gender Diverse Young Adults: The Intersectional Role of Racism and Transphobia

HIV prevalence and engagement in sexual behaviors associated with HIV transmission are high among transgender people of color. Per intersectionality, this disproportionate burden may be related to both interpersonal and structural racism and transphobia. The goal of this study was to estimate the association between interpersonal and structural discrimination and sexual behaviors among transgender and gender diverse (TGD) U.S. young adults. We used logit models with robust standard errors to estimate the individual and combined association between interpersonal and structural racism and transphobia and sexual behaviors in a national online sample of TGD young adults of color (TYAOC) aged 18-30 years (N = 228). Racism was measured at the interpersonal and structural level using the Everyday Discrimination Scale and State Racism Index, respectively. Transphobia was measured at the interpersonal and structural level using the Gender Minority Stress Scale and the Gender Identity Tally, respectively. We found that interpersonal racism was associated with transactional sex, and interpersonal transphobia was associated with alcohol/drug consumption prior to sex and transactional sex among TYAOC. We also found evidence of a strong joint association of interpersonal and structural racism and transphobia with alcohol/drug consumption prior to sex (OR 3.85, 95% CI 2.12, 7.01) and transactional sex (OR 3.54, 95% CI 0.99, 12.59) among TYAOC. Racism and transphobia have a compounding impact on sexual behaviors among TYAOC. Targeted interventions that reduce discrimination at both the interpersonal and structural level may help reduce the HIV burden in this marginalized population.

Virtual aids and students' performance with haptic simulation in implantology

OBJETIVES

This study aims to validate that haptic simulator assistance could improve drilling ability in implantology and that the repetition of training session could highlight a learning curve.

METHODS

This work was carried out with 88 first-year dental students. After randomization, students were divided into two groups. Group 1 was assigned to prepare an implant site for a left first mandibular molar (36) on haptic simulator with assistance provided by simulator. Group 2 had to perform the same exercise without assistance. Whatever the group, the maximum time for each reparation was restricted to 5 min. An interval of 1 week was done between each session. For each test, different objective parameters provided by the simulator were recorded and analyzed.

RESULTS

This study showed that the presence of virtual aids led to quickly obtain better results, and the training led to gradually acquire sufficient competence to do without virtual aids.

CONCLUSION

By associating virtual assistance and repetition, the student will acquire more quickly the skills allowing to carry out his clinical gestures in real conditions.

[Two experimental models for wound vitality evaluation in forensic pathology: A clinical prospective non-interventional study and an animal model]

AIM OF THE STUDY

In forensic pathology, wound age evaluation allows to determine if a wound was inflicted before or after death, and to date wounds of different ages. This dating is performed in conventional histopathology by observing inflammatory cells and hemorrhage at the wound site. However, these criteria seem to show low sensitivity and/or specificity. The aim of our study was to compare two models of wound vitality evaluation: a human surgical model, and a porcine experimental model; using these histological criteria.

PATIENTS AND METHOD

In the two human (n=38) and porcine (n=11) models, three wounds were performed at regular time-lapse before devascularization/sacrifice, and a control wound after devascularization/sacrifice. The main evaluation criteria were the presence of interstitial hemorrhage and the number of interstitial polymorphonuclear neutrophils at 10 high power fields.

RESULTS

In the two models, the number of polymorphonuclears neutrophils was significantly higher in vital wounds compared to the post-devascularization/sacrifice wounds (P<0.001), with a very low sensitivity (human model: 4.3%; porcine: 47%). Hemorrhagic infiltration was more frequent in vital wounds (human: P<0.001; porcine: P=0.01), with a low specificity (human: 48%; porcine: 54%).

DISCUSSION AND CONCLUSION

This first study confirms, in the two models, the limitations of conventional histopathology in wound vitality evaluation. The next step will be testing several immunohistochemical markers in the two models.

Current Predictors of Mortality in Veteran Patients Undergoing Major Lower Extremity Amputations: Risk Factors Have Not Changed and Mortality Remains High

Major lower extremity amputation (LEA-above the ankle) carries a high rate of mortality. In the present study, we performed an institutional review of all patients submitting to LEAs at a Veteran Administration Hospital (between 2009 and 2021) accompanied with a review of the literature.For the past 12 years, 1042 LEAs were performed in 603 patients at our hospital. The 30-day, 1-year, and 5-year mortalities were 8.5%, 28.9%, and 53.0%, respectively. Age, hypoalbuminemia, and Clavien-Dindo Class were independent predictors of mortality in all the time intervals in the analysis. Cardiac disease was not an independent predictor of mortality. In 39 studies reviewed, the average 30-day, 1-year, and 5-year mortality was 14%, 36%, and 56%, respectively. There was no difference in mortality in multiple studies analyzed. No significant temporal variation was identified between 1950 and 2000 vs. 2001 and 2021. Predictors of mortality were not substantially different from our institutional experience.The mortality rate for LEAs remains constant over time. Increasing age and hypoalbuminemia are strong predictors of short- and long-term mortality.

The importance of right heart function in heart failure with preserved ejection fraction

Funding Acknowledgements

Type of funding sources: None.

Background

Heart failure (HF) is a complex clinical syndrome that is a frequent cause of morbidity and mortality. Although half of patients with HF have a preserved ejection fraction (HFpEF), the majority of studies have examined the prognostic impact of left heart parameters instead of the right. We thus evaluated associations of right heart hemodynamics and echocardiographic measures with outcomes in HFpEF subjects.

Purpose

To perform long-term mortality analysis of patients with decompensated HFpEF using strain imaging and right heart catheterization hemodynamics.

Methods

This was a retrospective cross-sectional study which included patients hospitalized for acute heart failure exacerbation as the primary admitting diagnosis based on clinical and laboratory parameters as determined by the primary medical team. Patients included were only those with HFpEF and with available echocardiographic and right heart catheterization (RHC) hemodynamic data done during the index admission. 2D strain analysis software was used to automatically calculate right ventricular free wall strain (RVFWS), fractional area change (FAC), and left ventricular global longitudinal strain (LVGLS). Demographic and clinical parameters were obtained including RHC hemodynamics. The outcome of interest was long term 6-year all-cause mortality. Right and left ventricular echocardiographic strain and hemodynamic parameters were compared between patients with mortality and those who survived using independent T tests and non-parametric methods as appropriate. Multivariable logistic regression was used to identify echocardiographic and hemodynamic factors independently associated with all-cause mortality. Results From a total of 100 patients, 47% were Caucasian and 53% were female. The mean age was 67.4 ± 14.3. There was an 18% long term all cause mortality rate. Of the right sided echocardiographic strain parameters, only RVFWS was statistically significantly lower among those who died (12.0 vs 15.7 p = 0.038). Meanwhile, 4 chamber LVGLS was significantly lower (13.8 vs 15.1 p = 0.016) and mean right atrial (RA) pressure was higher (13.6 vs 10.7 p = 0.076) although this did not reach statistical significance. Looking at echocardiographic strain and hemodynamic parameters as predictors of mortality, after adjusting for age, gender and race accounting for the major differences in these parameters between the survival groups, only RVFWS (OR 1.90, 95% CI 1.12-3.28; p = 0.02) and RA pressure (OR 1.85, 95% CI 1.12-3.28; p = 0.016) remained independently associated with long term all-cause mortality with C statistic of 0.751 for the overall predictive model.

Conclusion

Among patients with HFpEF admitted for acute heart failure exacerbation, baseline RVFWS and RA hemodynamic pressure measurements were independently associated with long term all-cause mortality. This suggests that right heart diagnostic parameters may hold more prognostic utility in HFpEF. Abstract Figure.  Abstract Figure.

Isocitrate Dehydrogenase-Mutated Cholangiocarcinoma: Natural History and Clinical Outcomes

PURPOSE

Clinical-pathologic features and natural history of patients with isocitrate dehydrogenase (IDH)-mutant intrahepatic cholangiocarcinoma (CCA) are not well characterized. Here, we sought to describe the natural history, clinical phenotype, and prognostic impact of advanced, IDH-mutated CCA.

METHODS

We conducted a multicentric, retrospective analysis of patients with IDH-mutated (IDH1 or IDH2) CCA between 2010 and 2020. Median overall survival (OS) and progression-free survival (PFS) analyses were performed using the Kaplan-Meier method. Chi-square test was used to analyze disease control rate (DCR) and overall response rate (ORR). Matched controls were used for comparing survival between patients with and without IDH mutations (mIDH).

RESULTS

Sixty-five patients with IDH-mutated CCA were included. All patients had intrahepatic CCA. On first-line chemotherapy, median OS and median PFS were 21.2 months and 8.3 months, respectively. Notably, median OS (32.4 v 19.5 months, P = .12) and PFS (18.0 v 8.0 months, P = .12) were not significantly affected by disease status at presentation (locally advanced v metastatic, respectively). Median OS was significantly longer in patients with mIDH (21.2 v 10.5 months; P < .01). First-line gemcitabine-containing regimens had a significantly higher DCR and ORR than non-gemcitabine-containing regimens (DCR: 75% v 33%, P = .01; ORR: 39% v 0%, P = .02). In patients receiving IDH inhibitor therapy, median PFS was 4.6 months with a DCR of 29%.

CONCLUSION

CCA with mIDH confers a unique subtype resulting in a better survival compared with that of counterparts. IDH inhibitors represent a promising therapeutic option in later lines of therapy in this subgroup.

Endothelial Nitric Oxide Synthase (eNOS) and the Cardiovascular System: in Physiology and in Disease States

Endothelial nitric oxide synthase (eNOS) plays a critical role in regulating and maintaining a healthy cardiovascular system. The importance of eNOS can be emphasized from the genetic polymorphisms of the eNOS gene, uncoupling of eNOS dimerization, and its numerous signaling regulations. The activity of eNOS on the cardiac myocytes, vasculature, and the central nervous system are discussed. The effects of eNOS on the sympathetic autonomic nervous system (SANS) and the parasympathetic autonomic nervous system (PANS), both of which profoundly influence the cardiovascular system, will be elaborated. The relationship between the eNOS protein with cardiovascular autonomic reflexes such as the baroreflex and the Exercise Pressor Reflex will be discussed. For example, the effects of endogenous nitric oxide (NO) are shown to be mediated by the eNOS protein and that eNOS-derived endothelial NO is most effective in regulating blood pressure oscillations via modulating the baroreflex mechanisms. The protective action of eNOS on the CVS is emphasized here because dysfunction of the eNOS enzyme is intricately correlated with the pathogenesis of several cardiovascular diseases such as hypertension, arteriosclerosis, myocardial infarction, and stroke. Overall, our current understanding of the eNOS protein with a focus on its role in the modulation, regulation, and control of the cardiovascular system in a normal physiological state and in cardiovascular diseases are discussed.

Robust bulk micro-nano hierarchical copper structures possessing exceptional bactericidal efficacy

Conventional copper (Cu) metal surfaces are well recognized for their bactericidal properties. However, their slow bacteria-killing potency has historically excluded them as a rapid bactericidal material. We report the development of a robust bulk superhydrophilic micro-nano hierarchical Cu structure that possesses exceptional bactericidal efficacy. It resulted in a 4.41 log₁₀ reduction (>99.99%) of the deadly Staphylococcus aureus (S. aureus) bacteria within 2 min vs. a 1.49 log₁₀ reduction (96.75%) after 240 min on common Cu surfaces. The adhered cells exhibited extensive blebbing, loss of structural integrity and leakage of vital intracellular material, demonstrating the rapid efficacy of the micro-nano Cu structure in destructing bacteria membrane integrity. The mechanism was attributed to the synergistic degradation of the cell envelope through enhanced release and therefore uptake of the cytotoxic Cu ions and the adhesion-driven mechanical strain due to its rapid ultimate superhydrophilicity (contact angle drops to 0° in 0.18 s). The scalable fabrication of this micro-nano Cu structure was enabled by integrating bespoke precursor alloy design with microstructure preconditioning for dealloying and demonstrated on 2000 mm² Cu surfaces. This development paves the way to the practical exploitation of Cu as a low-cost antibiotic-free fast bactericidal material.

P08.01 Immune-Related Acute Motor Axonal Neuropathy: A Small Case Series and Review of the Literature

BACKGROUND

Immunotherapy have revolutionized cancer treatment in the past decade, with a significant increased survival in patients with solid tumors. However, the use of immune checkpoint inhibitors (ICIs) has been associated with a growing number of neurotoxicities, some of which can be fatal if not recognized and treated promptly. Some of these neurotoxicities include very uncommon syndromes like Acute Motor Axonal Neuropathy (AMAN). Herein we present four oncological cases of patients who underwent immunotherapy and developed AMAN.

METHODS

Four patients were diagnosed with immune-related AMAN between 2017 and 2000 at H. Lee Moffitt Cancer Center. The patients were treated with standard of care and currently follow up in clinic.

RESULTS

We describe four oncological patients who developed a motor axonal neuropathy (i.e., AMAN) confirmed on nerve conduction studies following 2 cycles of immunotherapy, including a 28 year old woman with melanoma brain metastasis and a 50 year old woman with renal cell carcinoma both treated with ipilimumab and nivolumab, a 32 year old man with Hodgkin lymphoma who was treated with nivolumab and brentuximab, and a 77 year old woman with renal urothelial cancer who was treated with pembrolizumab and cabozantinib. All four patients were promptly recognized as having immune-related neurotoxicity (irNs), were promptly treated (i.e., high dose steroids +/- IVIG +/- other immunomodulators), and significantly improved and have remained stable.

CONCLUSION

This is the first case series of patients with AMAN following two cycles of immunotherapy, who were successfully treated. It is crucial to develop a better understanding of the irNs associated with ICIs, including those rare conditions that are difficult to diagnose and treat, as the utilization of these immunomodulating therapies continues to increase and expand to include other solid malignancies. Neurologists should be involved early on in any case of suspected irN to assist in the management of these complicated patients and a swift work up should be initiated for timely diagnosis and treatment.

Evaluating the Feasibility and Acceptability of the Lifestyle Enhancement for ADHD Program

OBJECTIVE

To evaluate the feasibility and acceptability of the Lifestyle Enhancement for Attention Deficit Hyperactivity Disorder (ADHD) Program (LEAP), a novel parent behavior management training program that promotes physical activity (PA) and positive health behaviors and is enhanced with mobile health technology (Garmin) and a social media (Facebook) curriculum for parents of children with ADHD.

METHODS

The study included parents of children ages 5-10 years diagnosed with ADHD who did not engage in the recommended >60 min/day of moderate to vigorous PA based on parent report at baseline. Parents participated in the 8-week LEAP group and joined a private Facebook group. Children and one parent wore wrist-worn Garmin activity trackers daily. Parents completed the Treatment Adherence Inventory, Client Satisfaction Questionnaire, and participated in a structured focus group about their experiences with various aspects of the program.

RESULTS

Of 31 children enrolled, 51.5% had ADHD combined presentation, 36.3% with ADHD, predominately inattentive presentation, and 12.1% had unspecified ADHD (age 5-10; M = 7.6; 48.4% female). Parents attended an average of 86% of group sessions. On average, parents wore their Garmins for 5.1 days/week (average step count 7,092 steps/day) and children for 6.0 days/week (average step count 9,823 steps/day). Overall, parents and children were adherent to intervention components and acceptability of the program was high.

CONCLUSIONS

Findings indicate that the LEAP program is an acceptable and feasible intervention model for promoting PA among parents and their children with ADHD. Implications for improving ADHD symptoms and enhancing evidence-based parent training programs are discussed.

Safety and Immunogenicity of Adenovirus and Poxvirus Vectored Vaccines against a Mycobacterium Avium Complex Subspecies

Heterologous prime-boost strategies are known to substantially increase immune responses in viral vectored vaccines. Here we report on safety and immunogenicity of the poxvirus Modified Vaccinia Ankara (MVA) vectored vaccine expressing four Mycobacterium avium subspecies paratuberculosis antigens as a single dose or as a booster vaccine following a simian adenovirus (ChAdOx2) prime. We demonstrate that a heterologous prime-boost schedule is well tolerated and induced T-cell immune responses.

Re-assessing the role of the fecalith in acute appendicitis in adults: case report, case series and literature review

Appendicitis in adults is thought to occur because of luminal obstruction from a fecalith. We present a unique case of a patient who had her entire appendiceal lumen occupied by a fecalith (5.0 cm long) but had no appendicitis. We reviewed the records of 257 veterans who underwent surgical intervention at our institution for the management of acute appendicitis. Fecaliths occurred in 15.6% of patients. At laparotomy, 20.6% had a perforated appendix; pathology showed fecaliths in 20.8% of specimens. A review of the literature inclusive of 25 series showed fecaliths in 33.3% of patients with a normal appendix, 23.5% of patients with acute appendicitis and 24.9% with perforated appendicitis. These data show that appendicitis is not a common cause of fecalith obstruction in adults.

[Early- vs. late-onset treatment using abiraterone acetate plus prednisone in chemo-naïve, asymptomatic or mildly symptomatic patients with metastatic CRPC after androgen deprivation therapy]

BACKGROUND

 Abiraterone acetate (AA) is a prodrug of abiraterone, which is an irreversible inhibitor of 17α-hydroxylase/C17, 20-lyase. Since 2011, abiraterone acetate has been available in combination with prednisone/prednisolone (AA + P) for the treatment of metastatic castration-resistant prostate cancer (mCRPC) after pre-treatment with docetaxel, and since 2012 for the treatment of chemotherapy-naïve asymptomatic or mildly symptomatic mCRPC patients. A revision of the guidelines of the European Association of Urology in 2014 redefining castration resistance gave rise to the question of when the treatment of mCRPC with abiraterone acetate plus prednisone should be initiated after prior hormone treatment and how successful it would be. This led us to observe an early-onset AA + P therapy cohort (EC) and a late-onset therapy cohort (LC) of patients.

PATIENTS AND METHODS

 We designed a combined retrospective and prospective, multicentre, non-interventional two-cohort study to obtain data on the effectiveness and safety of an early-onset AA + P therapy in mCRPC patients in the clinical routine compared to a late therapy onset. The EC comprised patients who received AA + P immediately after castration resistance without a prior first-generation antiandrogen such as bicalutamide or flutamide. The LC included patients who, after castration resistance had occurred, started treatment with AA + P only after unsuccessful treatment with a first-generation antiandrogen. Patients with mCRPC who received AA + P therapy according to the physician's routine clinical practice decision were considered. The patients were consecutively included in the study on the basis of their medical records, with the treatment decision having been made independently of and before patient enrolment. Patients were documented or followed from the beginning of AA + P therapy until the start of a carcinoma-specific systemic follow-up therapy (retrospectively if before and prospectively if after start of data collection). Effectiveness analyses were done for all patients with at least two AA + P administrations and safety analyses for all treated patients.

RESULTS

 Of the 159 patients included, 44 received early therapy and 105 received later therapy with AA + P. 10 patients could not be clearly assigned and were summarised in a third cohort (missed early-onset therapy assignment; MEC). 56/159 patients (35.2 %) were still alive at study start and 103/159 patients (64.8 %) had already deceased (31/44 [70.5 %] in EC, 64/105 [61.0 %] in LC, and 8/10 [80.0 %] in MEC). 24/159 patients (15.1 %) were documented both retrospectively and prospectively. The median duration of AA + P treatment was 11.3 months for EC, 12.0 months for LC, and 8.3 months for MEC patients. The median time to next systemic cancer therapy or death was 12.3 months for EC and 12.8 months for LC patients (p = 0.2820). The median time to the next systemic cancer therapy alone (i. e. without the event 'death') was 22.7 months for EC and 23.3 months for LC patients (p = 0.5995). Median overall survival (OS) was 22.3 months for EC and 39.2 months for LC patients (p = 0.0232). The incidence of serious adverse events (SAEs) was low. SAEs occurred in 3/44 EC (6.8 %), 4/105 LC (3.8 %), and 1/10 MEC patients (10.0 %). One SAE in EC and one in LC resulted in death.

CONCLUSIONS

 In contrast to the new definition of castration resistance, AA + P was still more frequently used in daily clinical practice during the study observation period in patients treated with antiandrogens of the first generation after occurrence of castration resistance. Nevertheless, AA + P therapy appears to be effective and well tolerated during clinical routine in mCRPC patients. A comparison of the study results with earlier 'real-world' studies, however, has to take limiting factors into account. The observed difference in median overall survival might be explained by the imbalance of baseline characteristics between both cohorts with regard to number of patients, patients already deceased at start of documentation, patients with visceral metastases and patients with opioids at start of AA + P. For these reasons, patients in the EC initially might have had a poorer prognosis. A prospective randomised and controlled clinical trial would therefore be necessary to assess a possible difference in overall survival and response of the AA + P treatment with respect to therapy onset.

Anoxygenic photosynthesis and iron-sulfur metabolic potential of Chlorobia populations from seasonally anoxic Boreal Shield lakes

Aquatic environments with high levels of dissolved ferrous iron and low levels of sulfate serve as an important systems for exploring biogeochemical processes relevant to the early Earth. Boreal Shield lakes, which number in the tens of millions globally, commonly develop seasonally anoxic waters that become iron rich and sulfate poor, yet the iron-sulfur microbiology of these systems has been poorly examined. Here we use genome-resolved metagenomics and enrichment cultivation to explore the metabolic diversity and ecology of anoxygenic photosynthesis and iron/sulfur cycling in the anoxic water columns of three Boreal Shield lakes. We recovered four high-completeness and low-contamination draft genome bins assigned to the class Chlorobia (formerly phylum Chlorobi) from environmental metagenome data and enriched two novel sulfide-oxidizing species, also from the Chlorobia. The sequenced genomes of both enriched species, including the novel "Candidatus Chlorobium canadense", encoded the cyc2 gene that is associated with photoferrotrophy among cultured Chlorobia members, along with genes for phototrophic sulfide oxidation. One environmental genome bin also encoded cyc2. Despite the presence of cyc2 in the corresponding draft genome, we were unable to induce photoferrotrophy in "Ca. Chlorobium canadense". Genomic potential for phototrophic sulfide oxidation was more commonly detected than cyc2 among environmental genome bins of Chlorobia, and metagenome and cultivation data suggested the potential for cryptic sulfur cycling to fuel sulfide-based growth. Overall, our results provide an important basis for further probing the functional role of cyc2 and indicate that anoxygenic photoautotrophs in Boreal Shield lakes could have underexplored photophysiology pertinent to understanding Earth's early microbial communities.

Drawing from the Theory of Planned Behaviour to examine pre-exposure prophylaxis uptake intentions among heterosexuals in high HIV prevalence neighbourhoods in Philadelphia, Pennsylvania, USA: an observational study

Background Research surrounding attitudes and intentions concerning pre-exposure prophylaxis (PrEP) among at-risk heterosexuals, women and ethnic and racial minorities is needed to inform programs to scale this effective HIV prevention intervention among these populations.

METHODS

The study sample includes 192 HIV-negative heterosexuals recruited from HIV testing sites operating in high HIV prevalence neighbourhoods in a mid-Atlantic city. Participants received brief educational sessions on PrEP and completed a self-administered survey assessing sociodemographic factors, HIV risk behaviours and theoretical determinants of PrEP uptake, based on the Theory of Planned Behaviour.

RESULTS

Participants were majority persons of colour (86%), with a median age of 43 years. Compared with Whites, a higher percentage of Black and Brown persons had more than five sex partners (75.0%), used condoms inconsistently (85.6%) and engaged in transactional sex (84.4%). Most expressed positive PrEP attitudes and indicated intention to adopt PrEP, especially if recommended by their doctor. In a multivariable model, willingness to take PrEP if suggested by a healthcare provider (aOR: 4.17; 95% CI: 1.42-12.24) and willingness to take PrEP even if it caused side-effects (aOR: 1.98; 95% CI: 1.01-3.90) were both associated with greater PrEP adoption intentions.

CONCLUSIONS

A diverse at-risk population was identified through community-based HIV testing. Low perceived HIV risk, as well as PrEP-related attitudes, subjective norms and perceived behavioural control were associated with PrEP use intentions. These factors are potential targets for interventions to increase PrEP adoption among diverse heterosexual samples.

Heterosexual Men Anticipate Risk Compensatory Behaviors With Future Preexposure Prophylaxis Initiation: Findings From an Exploratory Cross-Sectional Study

Among 146 urban heterosexuals screening negative for human immunodeficiency virus, one third anticipated increased sexual risk taking with human immunodeficiency virus preexposure prophylaxis. Men (vs. women) and black (vs. white) participants had increased odds for anticipating decreased condom use. Men and persons reporting transactional sex expected to increase sexual partnerships. Risk compensation could affect reproductive health and disease control.

Safety and function of a new pre-vascularized bioartificial pancreas in an allogeneic rat model

Cell encapsulation could overcome limitations of free islets transplantation but is currently limited by inefficient cells immune protection and hypoxia. As a response to these challenges, we tested in vitro and in vivo the safety and efficacy of a new macroencapsulation device named MailPan^®. Membranes of MailPan^® device were tested in vitro in static conditions. Its bio-integration and level of oxygenation was assessed after implantation in non-diabetic rats. Immune protection properties were also assessed in rat with injection in the device of allogeneic islets with incompatible Major Histocompatibility Complex. Finally, function was assessed in diabetic rats with a Beta cell line injected in MailPan^®. In vitro, membranes of the device showed high permeability to glucose, insulin, and rejected IgG. In rat, the device displayed good bio-integration, efficient vascularization, and satisfactory oxygenation (>5%), while positron emission tomography (PET)-scan and angiography also highlighted rapid exchanges between blood circulation and the MailPan^®. The device showed its immune protection properties by preventing formation, by the rat recipient, of antibodies against encapsulated allogenic islets. Injection of a rat beta cell line into the device normalized fasting glycemia of diabetic rat with retrieval of viable cell clusters after 2 months. These data suggest that MailPan^® constitutes a promising encapsulation device for widespread use of cell therapy for type 1 diabetes.

Safety and immunogenicity of a candidate Middle East respiratory syndrome coronavirus viral-vectored vaccine: a dose-escalation, open-label, non-randomised, uncontrolled, phase 1 trial

BACKGROUND

Cases of Middle East respiratory syndrome coronavirus (MERS-CoV) infection continue to rise in the Arabian Peninsula 7 years after it was first described in Saudi Arabia. MERS-CoV poses a significant risk to public health security because of an absence of currently available effective countermeasures. We aimed to assess the safety and immunogenicity of the candidate simian adenovirus-vectored vaccine expressing the full-length spike surface glycoprotein, ChAdOx1 MERS, in humans.

METHODS

This dose-escalation, open-label, non-randomised, uncontrolled, phase 1 trial was done at the Centre for Clinical Vaccinology and Tropical Medicine (Oxford, UK) and included healthy people aged 18-50 years with negative pre-vaccination tests for HIV antibodies, hepatitis B surface antigen, and hepatitis C antibodies (and a negative urinary pregnancy test for women). Participants received a single intramuscular injection of ChAdOx1 MERS at three different doses: the low-dose group received 5 × 10⁹ viral particles, the intermediate-dose group received 2·5 × 10¹⁰ viral particles, and the high-dose group received 5 × 10¹⁰ viral particles. The primary objective was to assess safety and tolerability of ChAdOx1 MERS, measured by the occurrence of solicited, unsolicited, and serious adverse events after vaccination. The secondary objective was to assess the cellular and humoral immunogenicity of ChAdOx1 MERS, measured by interferon-γ-linked enzyme-linked immunospot, ELISA, and virus neutralising assays after vaccination. Participants were followed up for up to 12 months. This study is registered with ClinicalTrials.gov, NCT03399578.

FINDINGS

Between March 14 and Aug 15, 2018, 24 participants were enrolled: six were assigned to the low-dose group, nine to the intermediate-dose group, and nine to the high-dose group. All participants were available for follow-up at 6 months, but five (one in the low-dose group, one in the intermediate-dose group, and three in the high-dose group) were lost to follow-up at 12 months. A single dose of ChAdOx1 MERS was safe at doses up to 5 × 10¹⁰ viral particles with no vaccine-related serious adverse events reported by 12 months. One serious adverse event reported was deemed to be not related to ChAdOx1 MERS. 92 (74% [95% CI 66-81]) of 124 solicited adverse events were mild, 31 (25% [18-33]) were moderate, and all were self-limiting. Unsolicited adverse events in the 28 days following vaccination considered to be possibly, probably, or definitely related to ChAdOx1 MERS were predominantly mild in nature and resolved within the follow-up period of 12 months. The proportion of moderate and severe adverse events was significantly higher in the high-dose group than in the intermediate-dose group (relative risk 5·83 [95% CI 2·11-17·42], p<0·0001) Laboratory adverse events considered to be at least possibly related to the study intervention were self-limiting and predominantly mild in severity. A significant increase from baseline in T-cell (p<0·003) and IgG (p<0·0001) responses to the MERS-CoV spike antigen was observed at all doses. Neutralising antibodies against live MERS-CoV were observed in four (44% [95% CI 19-73]) of nine participants in the high-dose group 28 days after vaccination, and 19 (79% [58-93]) of 24 participants had antibodies capable of neutralisation in a pseudotyped virus neutralisation assay.

INTERPRETATION

ChAdOx1 MERS was safe and well tolerated at all tested doses. A single dose was able to elicit both humoral and cellular responses against MERS-CoV. The results of this first-in-human clinical trial support clinical development progression into field phase 1b and 2 trials.

FUNDING

UK Department of Health and Social Care, using UK Aid funding, managed by the UK National Institute for Health Research.

Morphological validation of a novel bi-material 3D-printed model of temporal bone for middle ear surgery education

Background

A new model of 3D-printed temporal bone with an innovative distinction between soft and hard tissues is described and presented in the present study. An original method is reported to quantify the model's ability to reproduce the complex anatomy of this region.

Methods

A CT-scan of temporal bone was segmented and prepared to obtain 3D files adapted to multi-material printing technique. A final product was obtained with two different resins differentiating hard from soft tissues. The reliability of the anatomy was evaluated by comparing the original CT-scan and the pre-processed files sent to the printer in a first step, and by quantifying the printing technique in a second step. Firstly, we evaluated the segmentation and mesh correction steps by segmenting each anatomical region in the CT-scan by two different other operators without mesh corrections, and by computing distances between the obtained geometries and the pre-processed ones. Secondly, we evaluated the printing technique by comparing the printed geometry imaged using µCT with the pre-processed one.

Results

The evaluation of the segmentation and mesh correction steps revealed that the distance between both geometries was globally less that one millimeter for each anatomical region and close to zero for regions such as temporal bone, semicircular canals or facial nerve. The evaluation of the printing technique revealed mismatches of 0.045±0.424 mm for soft and -0.093±0.240 mm for hard tissues between the initial prepared geometry and the actual printed model.

Conclusions

While other reported models for temporal bone are simpler and have only been validated subjectively, we objectively demonstrated in the present study that our novel artificial bi-material temporal bone is consistent with the anatomy and thus could be considered into ENT surgical education programs. The methodology used in this study is quantitative, inspired by engineer sciences, making it the first of its kind. The validity of the manufacturing process has also been verified and could, therefore, be extended to other specialties, emphasizing the importance of cross-disciplinary collaborations concerning new technologies.

Contribution of Haptic Simulation to Analogic Training Environment in Restorative Dentistry

The aim of this study was to evaluate the contribution of virtual reality to the conventional analogic training environment and show the complementarity of conventional techniques and virtual reality in the learning of dental students. All 88 first-year dental students at a dental school in France in early 2019 were randomly assigned to one of two groups: group 1 (n = 45) was assigned to cavity preparations on a haptic simulator (Virteasy) and group 2 (n = 43) was assigned to conventional practical work on plastic analogue teeth (Kavo). Following three training sessions, the students in group 1 took a final exam on the same plastic analogue teeth exercise. The results showed improvement in the drilling skill of both groups. The simulator-trained group (group 1) had similar results to the plastic analogue-trained group (group 2) in the final test on a plastic analogue tooth. In this study, virtual reality allowed an assessment based on objective criteria and reduced the subjectivity of evaluations conducted on plastic analogue teeth. Considering the saving of supervision and teaching time as well as the material gain offered by virtual reality, the learning methods of haptic simulators are educational options that should be considered by dental educators.