The line bisection bias as a deficit of proportional reasoning - evidence from number line estimation in neglect

This study aimed to investigate whether neurological patients presenting with a bias in line bisection show specific problems in bisecting a line into two equal parts or their line bisection bias rather reflects a special case of a deficit in proportional reasoning more generally. In the latter case, the bias should also be observed for segmentations into thirds or quarters. To address this question, six neglect patients with a line bisection bias were administered additional tasks involving horizontal lines (e.g., segmentation into thirds and quarters, number line estimation, etc.). Their performance was compared to five neglect patients without a line bisection bias, 10 patients with right hemispheric lesions without neglect, and 32 healthy controls. Most interestingly, results indicated that neglect patients with a line bisection bias also overestimated segments on the left of the line (e.g., one third, one quarter) when dissecting lines into parts smaller than halves. In contrast, such segmentation biases were more nuanced when the required line segmentation was framed as a number line estimation task with either fractions or whole numbers. Taken together, this suggests a generalization of line bisection bias towards a segmentation or proportional processing bias, which is congruent with attentional weighting accounts of line bisection/neglect. As such, patients with a line bisection bias do not seem to have specific problems bisecting a line, but seem to suffer from a more general deficit processing proportions.

Organ-specific responses to atezolizumab plus bevacizumab in advanced hepatocellular carcinoma: A multicentre, retrospective study

BACKGROUND AND AIMS

Anti-programmed death 1 (PD-1) monotherapy triggers various responses by each organ. In advanced hepatocellular carcinoma (HCC), while extrahepatic lesions demonstrate objective response rates (ORR) of 20%-40%, only 10% of intrahepatic lesions respond. Although first-line atezolizumab/bevacizumab has shown survival benefits in advanced HCC, organ-specific responses remain unexplored. Therefore, we aimed to assess organ-specific responses in patients with advanced HCC receiving atezolizumab/bevacizumab.

METHODS

This retrospective, multicenter, observational study included patients who received first-line atezolizumab/bevacizumab for advanced HCC. Patients with Child-Pugh class A, measurable tumour lesions and serial imaging available for response evaluation were eligible.

RESULTS

Between May 2020 and June 2021, 131 patients (median age: 62) from three cancer referral institutions were included. Ninety-one had hepatitis B (69.5%), 108 were at Barcelona clinic liver cancer stage C (82.4%), and 78 had extrahepatic metastasis (59.5%). After a median follow-up of 10.1 months, median progression-free survival was 6.8 months (95% confidence interval [CI], 4.6-9.2), median overall survival remained unreached (95% CI, range unavailable) and the ORR was 29.0%. Among 270 individual tumour lesions, the liver was the most commonly involved organ (n = 158). Atezolizumab/bevacizumab induced ORR of 27.8%, 42.2%, 29.1% and 21.0% for liver, lymph nodes, lungs and other sites, respectively. The organ-specific response rate for intrahepatic tumours decreased with increasing size (35.6%: <5 cm, 15.0%: ≥ 5 cm).

CONCLUSIONS

Unlike anti-PD-1 monotherapy, atezolizumab/bevacizumab demonstrated favourable responses in intrahepatic lesions, comparable to those in extrahepatic lesions, and may potentially overcome the immune-tolerant hepatic microenvironment in patients with advanced HCC.

ARID1A Mutation from Targeted Next-Generation Sequencing Predicts Primary Resistance to Gemcitabine and Cisplatin Chemotherapy in Advanced Biliary Tract Cancer

PURPOSE

There are clinical unmet needs in predicting therapeutic response and precise strategy for the patient with advanced biliary tract cancer (BTC). We aimed to identify genomic alterations predicting therapeutic response and resistance to gemcitabine and cisplatin (Gem/Cis)-based chemotherapy in advanced BTC.

MATERIALS AND METHODS

Genomic analysis of advanced BTC multi-institutional cohorts was performed using targeted panel sequencing. Genomic alterations were analyzed integrating patients' clinicopathologic data, including clinical outcomes of Gem/Cis-based therapy. Significance of genetic alterations was validated using clinical next-generation sequencing (NGS) cohorts from public repositories and drug sensitivity data from cancer cell lines.

RESULTS

193 BTC patients from three cancer centers were analyzed. Most frequent genomic alterations were TP53 (55.5%), KRAS (22.8%), ARID1A (10.4%) alterations, and ERBB2 amplification (9.8%). Among 177 patients with BTC receiving Gem/Cis-based chemotherapy, ARID1A alteration was the only independent predictive molecular marker of primary resistance showing disease progression for 1st-line chemotherapy in the multivariate regression model (odds ratio, 3.12; p=0.046). In addition, ARID1A alteration was significantly correlated with inferior progression-free survival on Gem/Cis-based chemotherapy in the overall patient population (p=0.033) and in patients with extrahepatic cholangiocarcinoma (CCA) (p=0.041). External validation using public repository NGS revealed that ARID1A mutation was a significant predictor for poor survival in BTC patients. Investigation of multi-OMICs drug sensitivity data from cancer cell lines revealed that cisplatin-resistance was exclusively observed in ARID1A mutant bile duct cancer cells.

CONCLUSION

Integrative analysis with genomic alterations and clinical outcomes of the first-line Gem/Cis-based chemotherapy in advanced BTC revealed that patients with ARID1Aalterations showed a significant worse clinical outcome, especially in extrahepatic CCA. Well-designed prospective studies are mandatory to validate the predictive role of ARID1Amutation.

Disconnection in a left-hemispheric temporo-parietal network impairs multiplication fact retrieval

Arithmetic fact retrieval has been suggested to recruit a left-lateralized network comprising perisylvian language areas, parietal areas such as the angular gyrus (AG), and non-neocortical structures such as the hippocampus. However, the underlying white matter connectivity of these areas has not been evaluated systematically so far. Using simple multiplication problems, we evaluated how disconnections in parietal brain areas affected arithmetic fact retrieval following stroke. We derived disconnectivity measures by jointly considering data from n = 73 patients with acute unilateral lesions in either hemisphere and a white-matter tractography atlas (HCP-842) using the Lesion Quantification Toolbox (LQT). Whole-brain voxel-based analysis indicated a left-hemispheric cluster of white matter fibers connecting the AG and superior temporal areas to be associated with a fact retrieval deficit. Subsequent analyses of direct gray-to-gray matter disconnections revealed that disconnections of additional left-hemispheric areas (e.g., between the superior temporal gyrus and parietal areas) were significantly associated with the observed fact retrieval deficit. Results imply that disconnections of parietal areas (i.e., the AG) with language-related areas (i.e., superior and middle temporal gyri) seem specifically detrimental to arithmetic fact retrieval. This suggests that arithmetic fact retrieval recruits a widespread left-hemispheric network and emphasizes the relevance of white matter connectivity for number processing.

Correlation of high serum interleukin-6 with clinical outcome and T cell response in patients with unresectable hepatocellular carcinoma treated with atezolizumab and bevacizumab

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Background: We elucidated the clinical and immunologic implications of serum interleukin (IL)-6 levels in patients with unresectable hepatocellular carcinoma (HCC) treated with atezolizumab and bevacizumab (Ate/Bev). Methods: We prospectively enrolled 165 patients with unresectable HCC (Discovery cohort: 84 patients from three centers; Validation cohort: 81 patients from one center). Baseline blood samples were analyzed using a flow cytometric bead array. The tumor immune microenvironment was analyzed using RNA sequencing. Results: In the Discovery cohort, clinical benefit (CB) was defined as a complete or partial response or stable disease for ≥ 6 months. Among various blood-based biomarkers, the serum IL-6 level was significantly higher in patients without CB than in those with CB (mean 11.56 vs. 5.05 pg/mL, P=0.02). The optimal cutoff value for high IL-6 was determined as 18.49 pg/mL using maximally selected rank statistics, and 15.2% of patients were identified to have high IL-6 levels at baseline. In both the Discovery and Validation cohorts, patients with high baseline IL-6 levels had a reduced response rate and worse progression-free and overall survival after Ate/Bev compared with that of patients with low IL-6 levels. In the multivariable Cox regression analysis, the clinical implication of high IL-6 levels persisted even after adjustment for various confounding factors. Patients with high IL-6 levels showed reduced interferon-γ and tumor necrosis factor-α secretion from CD8+ T cells. Moreover, excess IL-6 suppressed cytokine production and CD8+ T-cell proliferation. Finally, patients with high IL-6 levels exhibited a non-T-cell-inflamed immunosuppressive tumor microenvironment. Conclusions: High baseline IL-6 levels can be associated with poor clinical outcomes and impaired T-cell function in patients with unresectable HCC after Ate/Bev treatment.

High serum IL-6 correlates with reduced clinical benefit of atezolizumab and bevacizumab in unresectable hepatocellular carcinoma

Background & Aims

We elucidated the clinical and immunologic implications of serum IL-6 levels in patients with unresectable hepatocellular carcinoma (HCC) treated with atezolizumab and bevacizumab (Ate/Bev).

Methods

We prospectively enrolled 165 patients with unresectable HCC (discovery cohort: 84 patients from three centres; validation cohort: 81 patients from one centre). Baseline blood samples were analysed using a flow cytometric bead array. The tumour immune microenvironment was analysed using RNA sequencing.

Results

In the discovery cohort, clinical benefit 6 months (CB_6m) was defined as complete or partial response, or stable disease for ≥6 months. Among various blood-based biomarkers, serum IL-6 levels were significantly higher in participants without CB_6m than in those with CB_6m (mean 11.56 vs. 5.05 pg/ml, p = 0.02). Using maximally selected rank statistics, the optimal cut-off value for high IL-6 was determined as 18.49 pg/ml, and 15.2% of participants were found to have high IL-6 levels at baseline. In both the discovery and validation cohorts, participants with high baseline IL-6 levels had a reduced response rate and worse progression-free and overall survival after Ate/Bev treatment compared with those with low baseline IL-6 levels. In multivariable Cox regression analysis, the clinical implications of high IL-6 levels persisted, even after adjusting for various confounding factors. Participants with high IL-6 levels showed reduced interferon-γ and tumour necrosis factor-α secretion from CD8⁺ T cells. Moreover, excess IL-6 suppressed cytokine production and proliferation of CD8⁺ T cells. Finally, participants with high IL-6 levels exhibited a non-T-cell-inflamed immunosuppressive tumour microenvironment.

Conclusions

High baseline IL-6 levels can be associated with poor clinical outcomes and impaired T-cell function in patients with unresectable HCC after Ate/Bev treatment.

Impact and implications

Although patients with hepatocellular carcinoma who respond to treatment with atezolizumab and bevacizumab exhibit favourable clinical outcomes, a fraction of these still experience primary resistance. We found that high baseline serum levels of IL-6 correlate with poor clinical outcomes and impaired T-cell response in patients with hepatocellular carcinoma treated with atezolizumab and bevacizumab.

Atezolizumab plus bevacizumab in patients with child-Pugh B advanced hepatocellular carcinoma

Background

Atezolizumab plus bevacizumab (Ate/Bev) demonstrated promising efficacy and safety in patients with advanced hepatocellular carcinoma (HCC) in the phase III IMbrave150 trial. However, patients with Child-Pugh B HCC were excluded in the abovementioned prospective trial. Therefore, we aimed to investigate the efficacy and safety of Ate/Bev in patients with Child-Pugh B HCC.

Methods

This multicenter retrospective study included 36 patients with Child-Pugh B advanced HCC who received Ate/Bev at four cancer referral centers between May 2020 and August 2021. Comparative analyses were performed with an independent cohort of patients with Child-Pugh A HCC from the same registry (n = 133).

Results

All patients received Ate/Bev as first-line systemic treatment for advanced HCC. The objective response and disease control rates of patients in the Child-Pugh groups B and A were 11.1% and 58.3% and 34.6% and 76.7%, respectively. The median progression-free survival (PFS) and overall survival (OS) were 3.0 months [95% confidence interval (CI), 1.7-4.3) and 7.7 months (95% CI, 4.8-10.6) in the Child-Pugh B group, whereas the median PFS and OS were 9.6 months (95% CI, 5.1-14.2) and not reached (95% CI, not available) in the Child-Pugh A group, respectively. Compared to the Child-Pugh A group, grade 3-4 adverse events (AEs) were more common in the Child-Pugh B group (44.4% versus 15.8, p < 0.001), with the most frequent grade 3-4 AEs being gastrointestinal bleeding (n = 6, 16.7%), neutropenia (n = 5, 13.9%), and thrombocytopenia (n = 4, 11.1%).

Conclusions

In the Child-Pugh B subgroup of patients with advanced HCC, Ate/Bev treatment showed modest clinical activity. However, due to the increased frequency of serious AEs, careful evaluation of treatment response and AE management is required in this subgroup of patients.

Association of High Levels of Antidrug Antibodies Against Atezolizumab With Clinical Outcomes and T-Cell Responses in Patients With Hepatocellular Carcinoma

Importance

Administration of atezolizumab could be immunogenic and induce undesirable antidrug antibody (ADA) responses. This may interfere with atezolizumab-mediated actions, affecting drug clearance and serum concentration or inducing antibody neutralization.

Objective

To determine the clinical and immunological associations of highly elevated ADA levels with clinical outcomes after atezolizumab/bevacizumab (Atezo/Bev) treatment in patients with advanced hepatocellular carcinoma (HCC).

Design, Setting, and Participants

This cohort study prospectively enrolled 174 patients with advanced HCC treated with first-line Atezo/Bev (discovery cohort: 61 patients from 1 center; validation cohort: 113 patients from 4 centers).

Exposures

Serum ADA levels at pretreatment and 3 weeks (cycle 2 day 1 [C2D1]) were analyzed using competitive enzyme-linked immunosorbent assays. In addition, samples were subjected to serological and flow cytometric analyses.

Main Outcomes and Measures

Overall, ADA positivity was associated with treatment outcomes and T-cell functions.

Results

After excluding patients with inadequate samples, follow-up loss, or consent withdrawal, 132 patients (discovery cohort: 50 patients; 41 [82.0%] men; median age [IQR], 61 [55-70] years; validation cohort: 82 patients; 70 [85.4%] men; median age [IQR], 61 [53-68] years) were analyzed, and robust ADA (≥1000 ng/mL) responses at C2D1 were identified in 23 (17.4%) of the patients. Patients with progressive disease exhibited higher ADA levels (median [IQR], 65.2 [0-520.4] ng/mL) at C2D1 than in responders (median [IQR], 0 [0-117.5] ng/mL). In both discovery and validation cohorts, patients with high ADA levels at C2D1 were associated with a reduced response rate (discovery cohort: 34% vs 11%; validation cohort: 29% vs. 7%) and worse progression-free survival (discovery cohort: hazard ratio [HR], 2.84; 95% CI, 1.31-6.13; P = .005; validation cohort: HR, 2.52; 95% CI, 1.27-5.01; P = .006) and overall survival (discovery cohort: HR, 3.30; 95% CI, 1.43-7.64; P = .003; validation cohort: HR, 5.81, 95% CI, 2.70-12.50; P = .001) with Atezo/Bev compared with those with low ADA levels. In multivariable Cox regression, the clinical implication of high ADA levels persisted even after adjusting for various confounding factors and was most significant at 1000 ng/mL or greater. Compared with patients with low ADA levels, patients with high ADA levels exhibited reduced serum atezolizumab concentrations, impaired CD8-positive T-cell proliferation, and had decreased interferon-γ and tumor necrosis factor-α from CD8-positive T cells compared with patients with low ADA levels.

Conclusions and Relevance

This cohort study found that highly elevated ADA levels at C2D1 may be associated with poor clinical outcomes in patients with advanced HCC treated with Atezo/Bev. High ADA levels may reduce atezolizumab exposure and attenuate the anticancer efficacy of the drug.

Membranous septum length as predictor for permanent pacemaker implantation after TAVI

Background

High-degree atrioventricular (AV) block and permanent pacemaker (PPM) implantation represent major complications after transcatheter aortic valve implantation (TAVI). Extension of indication for TAVI towards subjects with lower surgical risk requires to reduce the likelihood for the requirement of permanent pacemaker (PPM) implantation. Data on the role of membranous septum length as potential predictor for AV block after TAVI are scarce.

Purpose

We examined the role of membranous septum length as potential predictor for AV block and the need for PPM implantation in a large cohort of consecutive subjects after TAVI.

Methods

In a cohort of 1365 patients without prior permanent pacemaker who underwent transfemoral TAVI, clinical and procedural characteristics were assessed systematically. Based on cardiac computed tomography performed prior to TAVI, membranous septum length was measured orthogonal to the anulus plane (see figure).

Results

Median age of subjects was 81 (IQR 7) years, 50% were male. Logistic euroSCORE was 12.8 (IQR 15.7), STS score 3 (2.7). 9,8% of subjects had a pre-interventional complete right bundle branch block (RBBB). 71% of patients received a balloon-expandable, 29% a self-expandable valve. In n=153 patients (11.2%), PPM implantation was necessary due to high-degree AV block. Median membranous septum length was 2.9 mm (IQR 2.5mm) in subjects who received a PPM versus 4.3 mm (IQR 3.2 mm) in subjects who did not need a PPM (p=0.061). In univariate regression analysis, pre-interventional complete RBBB (p&lt;0.001, OR 7.8), implantation of a self-expandable prosthesis (p=0002, OR 1.7) and membranous septum length (p=0.027, OR 0.9 per 1 mm) were identified as significant predictors for PPM implantation. In multivariate regression analysis, all parameters remained significant, including membranous septum length (p=0.009, OR 0.9 per 1 mm).

Conclusion

In a large cohort of consecutive patients, we were able to confirm the significant independent predictive value of membranous septum length, in addition to pre-interventional complete RBBB or implantation of a self-expandable prosthesis, regarding the occurrence of post-procedural AV block with the need for PPM implantation. The results may contribute to improved risk stratification for potential PPM implantation after TAVI.

Funding Acknowledgement

Type of funding sources: None.

The presence and size of intrahepatic tumors determine the therapeutic efficacy of nivolumab in advanced hepatocellular carcinoma

Purpose:

Inter-tumoral heterogeneity at the differential lesion level raises the possibility of distinct organ-specific responses to immune checkpoint inhibitors (ICIs). We aimed to comprehensively examine the clinicopathological factors to predict and assess the efficacy of nivolumab, programmed cell death protein 1 (PD-1) blockade at an individual tumor site-specific level in patients with advanced hepatocellular carcinoma (aHCC).

Patients and Methods:

We enrolled 261 aHCC patients treated with nivolumab between 2012 and 2018. Eighty-one clinicopathological factors were comprehensively collected and analyzed. The association between all variables and survival outcomes was evaluated. According to tumor site, the organ-specific responses were assessed based on the Response Evaluation Criteria in Solid Tumors, version 1.1.

Results:

The liver was the most commonly involved organ (75.1%), followed by the lungs (37.5%) and lymph nodes (LNs, 11.5%). The liver of nonresponders was more frequently the organ of progression, while the lungs of responders were more frequently the organs of response. Among the 455 individual lesions (liver, n = 248; lung, n = 124; LN, n = 35; others including bone or soft tissues, n = 48), intrahepatic tumors showed the least response (10.1%), followed by lung (24.2%) and LN tumors (37.1%), indicating the presence of distinct organ-specific responses to nivolumab. In intrahepatic tumors, the organ-specific response rate decreased as the size increased (13% for ⩽50 mm, 8.1% for 50–100 mm, and 5.5% for >100 mm). In the subgroup analysis according to tumor location, patients with lung only metastasis (⩾30 mm) showed the best progression-free survival (PFS) and overall survival (OS). In contrast, primary HCC (⩾100 mm) without lung metastasis had the worst PFS and OS. Comprehensive analyses also revealed that liver function and systemic inflammatory indices, such as neutrophil-to-lymphocyte ratio (NLR), were significantly associated with PFS and OS.

Conclusion:

The presence and size of liver tumors, liver function, and NLR are key factors determining the response to nivolumab in aHCC. These clinical factors should be considered when treating patients with advanced HCC with PD-1 blockade.

Multi-disciplinary assessment of the entrustable professional activities of surgery residents

Purpose

Medicine is practiced in a collaborative and interdisciplinary manner. However, medical training and assessment remain largely isolated in traditional departmental silos. Two Entrustable Professional Activities (EPAs) developed by the American Board of Surgery are multidisciplinary in nature and offer a unique opportunity to study interdisciplinary assessment.

Methods

EPA microassessments were collected from Surgery and Emergency Medicine (EM) faculty between July 2018 and May 2020. Differences in feedback provided by faculty were assessed using natural language processing (NLP) techniques, (1) automated algorithms; and (2) topic modeling. Summative content analysis was used to identify themes in text feedback. We developed automated coding algorithms for these themes using regular expressions. Topic modeling was performed using latent Dirichlet allocation.

Results

549 assessments were collected for two EPAs: 198 for GS Consultation and 351 for Trauma. 27 EM and 27 Surgery faculty provided assessments for 71 residents. EM faculty were significantly more likely than Surgery faculty to submit feedback coded as Communication, Demeanor, and Timeliness, (all chi-square test p-values < 0.01). No significant differences were found for Clinical Performance, Skill Level, or Areas for Improvement. Similarly, topic modeling indicated that assessments submitted by EM faculty focused on communication, timeliness, and interpersonal skills, while those submitted by Surgery faculty focused on the residents' abilities to effectively gather information and correctly diagnose the underlying pathology.

Conclusions

Feedback from EM and Surgery faculty differed significantly based on NLP analyses. EPA assessments should stem from multiple sources to avoid assessment gaps and represent a more holistic picture of performance.

High atezolizumab antidrug antibody levels are associated with unfavorable clinical outcomes and diminished T cell responses following atezolizumab and bevacizumab treatment in advanced hepatocellular carcinoma

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Background: Systemic administration of humanized monoclonal antibodies can be immunogenic and trigger unwanted anti-drug antibody (ADA) responses. In the IMbrave 150 study, 29.6% of advanced hepatocellular carcinoma (HCC) patients developed atezolizumab ADAs after atezolizumab and bevacizumab (atezo/bev) treatment. ADAs could impair the action of the therapeutic antibody by reduction of serum concentration or neutralization. We determined the clinical and immunological implications of high ADA levels in advanced HCC patients after atezo/bev treatment. Methods: Advanced HCC patients (n = 132) treated with first-line atezo/bev were prospectively enrolled (discovery cohort: 50 from an institute; validation cohort: 82 from four institutes). Serum levels of atezolizumab ADA at baseline and three weeks (C2D1) and atezolizumab concentrations at C2D1 were measured by competitive ELISA. The effects of ADA on T cell immunity were examined by multiplex flow cytometry. Results: Strong ADA (≥ 1000 ng/ml) responses at C2D1 were observed in 17.4% of advanced HCC patients. ADA elevation after atezo/bev at C2D1 was evident in non-responders but not significant in responders. In the discovery cohort, patients with high ADA at C2D1 showed a decreased response rate (ADA-high: 11% and ADA-low: 34%) and shorter progression-free survival (PFS) and overall survival (OS) with atezo/bev compared to those with low ADA levels ( P = 0.004 for PFS; P = 0.009 for OS). In the validation cohort, patients with high ADA at C2D1 showed reduced response rate than those with low ADA (ADA-high: 7% and ADA-low: 29%). PFS and OS were worse in ADA-high group than in ADA-low group ( P = 0.001 for PFS; P < 0.001 for OS). In multivariate Cox regression analysis, the clinical significance of high ADA levels was independently associated with shorter PFS and OS after adjustment for age, sex, ECOG performance status, Child-Pugh score, AFP, macroscopic vascular invasion, extrahepatic spread, and neutrophil-to-lymphocyte ratio (PFS: HR 2.27, P = 0.006; OS: HR 3.04, P = 0.006). The atezolizumab serum concentrations were 29.8% lower in patients with high ADA levels than in ADA-negative patients. Atezolizumab concentration at C2D1 was inversely correlated with ADA levels. Moreover, patients with high ADA lacked CD8+ T cell proliferative responses to atezo/bev treatment. Furthermore, patients with high ADA had decreased secretion of effector cytokines such as IFN-γ and TNF-α from CD8+ T cells compared to those with low ADA. Conclusions: Highly elevated ADA at C2D1 is associated with unfavorable clinical outcomes in advanced HCC patients treated with atezo/bev. High ADA levels were associated with reduced atezolizumab exposure and could limit the drug’s anti-cancer efficacy.

Diagnostic Accuracy of High-Resolution 3D T2-SPACE in Detecting Cerebral Venous Sinus Thrombosis

BACKGROUND AND PURPOSE

Assessment of cerebral venous sinus thrombosis on MR imaging can be challenging. The aim of this study was to evaluate the diagnostic accuracy of high-resolution 3D T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) in patients with cerebral venous sinus thrombosis and to compare its performance with contrast-enhanced 3D T1-MPRAGE.

MATERIALS AND METHODS

We performed a blinded retrospective analysis of T2-SPACE and contrast-enhanced MPRAGE sequences from patients with cerebral venous sinus thrombosis and a control group. The results were compared with a reference standard, which was based on all available sequences and clinical history. Subanalyses were performed according to the venous segment involved and the clinical stage of the thrombus.

RESULTS

Sixty-three MR imaging examinations from 35 patients with cerebral venous sinus thrombosis and 51 examinations from 40 control subjects were included. The accuracy, sensitivity, and specificity calculated from the initial MR imaging examination for each patient were 100% each for T2-SPACE and 95%, 91%, and 98%, respectively, for contrast-enhanced MPRAGE. The interrater reliability was high for both sequences. In the subanalysis, the accuracy for each venous segment involved and if subdivided according to the clinical stage of thrombus was ≥95% and ≥85% for T2-SPACE and contrast-enhanced MPRAGE, respectively.

CONCLUSIONS

Both T2-SPACE and contrast-enhanced MPRAGE offer high accuracy for the detection and exclusion of cerebral venous sinus thrombosis; however, T2-SPACE showed a better overall performance and thus could be a useful tool if included in a multiparametric MR imaging protocol for the diagnosis of cerebral venous sinus thrombosis, especially in scenarios where gadolinium administration is contraindicated.

Organ-specific responses to atezolizumab plus bevacizumab in patients with advanced hepatocellular carcinoma

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Background: Anti-PD-1 monotherapy elicits various organ-specific immune responses. Although advanced hepatocellular carcinoma (aHCC) showed 20–40% objective response rates (ORR) for cases of extrahepatic lesions in sites such as the lungs or lymph nodes (LNs), only 10% of intrahepatic lesions responded to the monotherapy. The organ-specific responses were due to tumor heterogeneity and differential microenvironments, and may have contributed to the failure of the phase III trials of anti-PD-1 monotherapy for aHCC. Recently, the combination of atezolizumab and bevacizumab (Ate/Bev) as first-line systemic treatment has resulted in survival benefits for patients with aHCC. However, the organ-specific response for this treatment has not been explored. We aimed to evaluate the organ-specific response to Ate/Bev combination therapy in patients with aHCC. Methods: We enrolled patients who received first-line Ate/Bev treatment for aHCC. Eligible patients included those with Child-Pugh A liver function, measurable tumor lesions, and serial image studies available for response evaluation. An independent radiologist reviewed the tumors located in the liver, lungs, LNs, and other sites. Organ-specific response criteria, adapted from RECIST 1.1 and immune-related RECIST, were used. Results: Between May 2020 and June 2021, 124 patients from two Korean cancer referral institutions received first-line Ate/Bev treatment for aHCC. The patient baseline characteristics included: hepatitis B (n = 85, 68.5%), hepatitis C (n = 6, 4.8%), non-viral (n = 33, 26.7%); BCLC stage A/B/C (n = 2, 1.6%/n = 19, 15.3%/n = 103, 83.1%); macrovascular invasion (n = 39, 31.5%); extrahepatic metastasis (n = 75, 60.5%); and AFP >400 ng/ml (n = 39, 31.5%). The median age was 62 years (range: 34–90). With median follow-up duration of 10.1 months, median progression-free survival was 6.8 months (95% CI, 3.6–10.0) and median overall survival was 16.9 months (95% CI, range not available). The ORR was 29.8%. For 260 individual tumor lesions, the liver was the most commonly involved organ (n = 152, 58.5%), followed by the LNs (n = 42, 16.2%) and lungs (n = 24, 9.2%). Ate/Bev treatment induced potent tumor shrinkage in both intrahepatic and extrahepatic lesions: ORR for hepatic lesions was 28.3%; LN lesions, 40.5%; lung lesions, 29.1%; and other metastatic lesions, 19.0%. Further, the organ-specific response rate for intrahepatic tumors decreased as the tumor size increased (36.7%: ≤50 mm, 13.0%: >50 mm). Conclusions: Unlike anti-PD-1 monotherapy, Ate/Bev combination therapy showed favorable responses even in intrahepatic lesions, which are comparable to those in extrahepatic lesions. As such, Ate/Bev may overcome an immune-tolerant hepatic microenvironment in patients with aHCC. (NCT04862949).

Effect of empagliflozin on ketone bodies in patients with stable chronic heart failure

Background

Recent studies indicated that sodium glucose cotransporter (SGLT)2 inhibition increases levels of ketone bodies in the blood in patients with type 1 and 2 diabetes. Other studies suggested that in patients with chronic heart failure (CHF), increased myocardial oxygen demand can be provided by ketone bodies as a fuel substrate. Experimental studies reported that ketone bodies, specifically beta-hydroxybutyrate (β-OHB) may increase blood pressure (BP) by impairing endothelium-dependant relaxation, thereby leading to increased vascular stiffness. In our study we assessed whether the SGLT 2 inhibition with empagliflozin increases ketone bodies in patients with stable CHF and whether such an increase impairs BP and vascular function.

Methods

In a prospective, double blind, placebo controlled, parallel-group single centre study 75 patients with CHF (left ventricular ejection fraction 39.0 ± 8.2%) were randomised (2:1) to the SGLT-2 inhibitor empagliflozin 10 mg orally once daily or to placebo, 72 patients completed the study. After a run-in phase we evaluated at baseline BP by 24 h ambulatory blood pressure (ABP) monitoring, vascular stiffness parameters by the SphygmoCor system (AtCor Medical, Sydney, NSW, Australia) and fasting metabolic parameters, including β-OHB by an enzymatic assay (Beckman Coulter DxC 700 AU). The same measurements were repeated 12 weeks after treatment. In 19 of the 72 patients serum levels of β-OHB were beneath the lower border of our assay (< 0.05 mmol/l) therefore being excluded from the subsequent analysis.

Results

In patients with stable CHF, treatment with empagliflozin (n = 36) was followed by an increase of β-OHB by 33.39% (p = 0.017), reduction in 24 h systolic (p = 0.038) and diastolic (p = 0.085) ABP, weight loss (p = 0.003) and decrease of central systolic BP (p = 0.008) and central pulse pressure (p = 0.008). The increase in β-OHB was related to an attenuated decrease of empagliflozin-induced 24 h systolic (r = 0.321, p = 0.069) and diastolic (r = 0.516, p = 0.002) ABP and less reduction of central systolic BP (r = 0.470, p = 0.009) and central pulse pressure (r = 0.391, p = 0.033). No significant changes were seen in any of these parameters after 12 weeks of treatment in the placebo group (n = 17).

Conclusion

In patients with stable CHF ketone bodies as assessed by β-OHB increased after treatment with empagliflozin. This increase led to an attenuation of the beneficial effects of empagliflozin on BP and vascular parameters.

Trial registration The study was registered at http://www.clinicaltrials.gov (NCT03128528).

Reduced tissue sodium content is related to improvement of vascular function in patients with chronic heart failure treated with the SGLT2 inhibitor empagliflozin

Background

Large randomized controlled trials have demonstrated that SGLT2 inhibitors produce cardiovascular benefits beyond their metabolic effects. One of the assumed underlying mechanisms is the reduction of the left ventricular afterload. Factors aggravating the afterload are impaired vascular function (ventricular-arterial coupling) as well as high tissue sodium content, which exerts enhanced hypertrophic stimuli and exaggerated response to vasoconstrictors.

Purpose

We hypothesized that the SGLT2 inhibitor empagliflozin leads to afterload reduction in patients with chronic heart failure (CHF) by reducing tissue sodium content and improving vascular function and that these changes are related to each other.

Methods

In a randomized (2:1), investigator initiated, double-blind, placebo controlled, parallel-group, prospective clinical study, patients with CHF NYHA II-III and an ejection fraction of 49% or less were randomized to empagliflozin 10mg once daily or placebo. In each patient, we assessed vascular parameters under resting conditions (Sphygmocor) and 24-hour daily life conditions (Mobilograph), including central systolic pressure (cSBP) and central pulse pressure (cPP) among others. In parallel, we measured tissue (skin and muscle) sodium content of the lower leg by Sodium-MRI, at baseline and after 1 month of therapy.

Results

A total of 74 patients (men: n=62), aged 66±9 years, with a mean ejection fraction of 39±9% were included. Only 24% of the patients had type 2 diabetes. After 1 month treatment with empagliflozin, a decrease of skin sodium content was observed (22.8±6.1 vs. 21.6±6.0 mmol/l, p=0.039), while there was no significant change in muscle sodium and muscle water content. A decrease of cSBP (117.1±14.5 vs. 110.7±11.3 mmHg, p&lt;0.001) and cPP (41.4±8.8 vs. 38.4±8.5 mmHg, p=0.004) under resting conditions was observed after 1 month treatment with empagliflozin, while changes in the placebo group were not significant for cSBP (117.0±18.1 vs. 116.3±15.0 mmHg, p=0.759) and cPP (40.6±9.1 vs. 39.4±8.6 mmHg, p=0.422). Similarly, there was a decrease of cSBP and cPP in patients with empagliflozin treatment under ambulatory conditions, but not in the placebo group. In the whole group, we observed a significant correlation between change in skin sodium content and change in vascular parameters such as cSBP (r=0.364, p=0.004) and cPP (r=0.250, p=0.054) after 1 month of treatment with empagliflozin or placebo.

Conclusion(s)

Significant changes in skin sodium content induced by empagliflozin and a significant correlation between changes in skin sodium content and vascular function suggest that a reduction of tissue sodium content may be one of the mechanisms underlying the beneficial effects of SGLT2 inhibitors in heart failure.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim International GmbH.

High-degree atrioventricular block after valve-in-valve transcatheter aortic valve implantation: incidence and predictors

Background

High-degree atrioventricular (AV) block and permanent pacemaker (PPM) implantation represent major complications after transcatheter aortic valve implantation (TAVI). Data on the incidence of AV block for patients undergoing valve-in-valve (ViV) TAVI are scarce. We examined the incidence and predictors of periinterventional AV conduction disturbances in a cohort of subjects undergoing ViV TAVI compared to subjects undergoing TAVI of native aortic valves.

Methods

In 50 consecutive patients who underwent ViV TAVI, clinical characteristics, incidence and predictors for AV conduction disturbances as well as intrahospital outcome were assessed. Applying a matched pair approach for age, gender, type and size of transcatheter valve, these subjects were compared to 50 patients undergoing TAVI of native tricuspid aortic valves.

Results

Mean age in both groups was 80±6 years and 50% of subjects were male. In the ViV group, 22 patients (44%) had a stented bioprosthesis, 10 patients (20%) a stentless bioprosthesis and 18 patients (36%) a previous TAVI prosthesis (balloon-expandable: n=15, self-expandable n=3). The majority of subjects (92% in each group) were treated using balloon-expandable valves (ViV group: Sapien XT, n=20 or Sapien 3, n=26, control group: Sapien XT, n=19 or Sapien 3, n=27).

Periinterventional, non-reversible 3rd degree AV-block occurred in 6 patients within each group (12%), and all of the affected patients underwent PPM implantation. Among the 32 patients who underwent ViV-TAVI of a surgically placed bioprosthesis, only 2 (6%) developed a high-degree AV block (1/22 with a stented bioprosthesis and 1/10 with a stentless bioprosthesis). In contrast, high-degree AV block occurred in 4/18 patients (22%) who underwent ViV TAVI of a prior TAVI prosthesis. There was a significant difference in the occurrence of total high-degree AV blocks requiring postinterventional PPM implantation (p=0.033) between subjects who received TAVI of stented bioprostheses and those who received re-TAVI.

In logistic regression analysis, pre-existing RBBB represented a significant predictor for periinterventional 3rd degree AV block across the whole cohort (p=0.001, Exp(B)=10.667), both in ViV subjects (p=0.016, Exp(B)=12.0) and in the control group (p=0.018, Exp(B)=10.0).

Conclusion

Periinterventional AV block occurs infrequently in subjects undergoing ViV TAVI for treatment of degenerated surgical bioprostheses. However, patients undergoing ViV TAVI for degenerated transcatheter prostheses as well as subjects with pre-existing RBBB are at substantial risk for the occurence of AV block and require close peri-interventional monitoring.

Funding Acknowledgement

Type of funding sources: None.

P04.22 Tumor treating fields in high-grade glioma patients: A retrospective single-center study

BACKGROUND

Tumor-treating fields (TTFields) are a modern anti-mitotic, non-invasive therapy for the treatment of patients with recurrent and newly diagnosed glioblastoma multiforme (GBM). In Europe, Optune® recieved in 2015 the CE certification. TTFields are a low-intensity (1–3 V/cm) approved therapeutic modality using a non-invasive application of intermediate frequency (200 kHz) alternating electric fields through four transducer arrays directly applied to the skin. The EF-14 study has shown that the addition of TTFields to temozolomide chemotherapy in patients with newly diagnosed GBM significantly improved overall survival (OS) and progression-free survival (PFS) without additional adverse events, apart from mild to moderate skin irritations (Stupp et al., JAMA 2017).

MATERIAL

We retrospectively analyzed data from TTFields-treated patients (2015–2020) that were treated at our department. Patient characteristics such as MGMT promoter methylation status, age, and diagnosis, as well as treatment duration and TTFields therapy usage, were evaluated for this study.

RESULTS

29 patients were treated with TTFields therapy between 2015 and 2020 at our hospital. Most patients received TTFields as primary treatment together with temozolomide maintenance therapy. In detail, 48% of patients were diagnosed with newly diagnosed GBM, 41% received TTFields therapy after tumor recurrence and 10% were diagnosed with other high-grade gliomas. In summary, patients could integrate TTFields therapy into their daily life and showed high adherence to the therapy.Particularly, one of our patients (with MGMT-promoter methylation positive) receives TTFields therapy now for almost 1229 days (approx. 41 months) and is still on therapy. Additionally, this patient shows a high usage rate of 86% indicating well integration of the therapy into daily life.

CONCLUSION

Taken together, our data provided the outcomes of using TTFields together with chemotherapy in the treatment of recurrent and newly diagnosed GBM in our department. Therapy with TTFields has been showing to provide significant clinical benefit for GBM patients.

High Rate of False Negative Diagnosis of Silent Patent Ductus Arteriosus on the Chest CT with 3 mm Slice-Thickness, Suggesting the Need for Analysis with Thinner Slice Thickness

The purpose of this study was to evaluate the diagnostic accuracy of patent with ductus arteriosus (PDA) based on the availability of pretest information on routine chest CT with 3 mm slice-thickness. We retrospectively evaluated CT of 64 patients with PDA. The enrolled patients were categorized as group 1 (presence of pretest information) and 2 (absence of pretest information, silent PDA). CTs were read by eleven board-certified radiologists, and subsequently by two blind readers. We investigated whether a PDA was mentioned on the initial CT reading. Correct diagnosis of PDA was made in all patients with group 1 (n = 42). In contrast, only 13.7% were correctly diagnosed in group 2. All cases of missed PDA in group 2 were also missed by two blind readers. It is important to realize that the diagnostic accuracy of silent PDA is poor on the chest CT with 3 mm slice-thickness. Thus, use of axial CT images with the thinnest slice-thickness and multi-planar reformatted images (i.e., sagittal and coronal images) may be one way to reduce the number of missed PDA.

Orbital Complexity in Intrinsic Magnetic Topological Insulators MnBi_{4}Te_{7} and MnBi_{6}Te_{10}

Using angle-resolved photoelectron spectroscopy (ARPES), we investigate the surface electronic structure of the magnetic van der Waals compounds MnBi_{4}Te_{7} and MnBi_{6}Te_{10}, the n=1 and 2 members of a modular (Bi_{2}Te_{3})_{n}(MnBi_{2}Te_{4}) series, which have attracted recent interest as intrinsic magnetic topological insulators. Combining circular dichroic, spin-resolved and photon-energy-dependent ARPES measurements with calculations based on density functional theory, we unveil complex momentum-dependent orbital and spin textures in the surface electronic structure and disentangle topological from trivial surface bands. We find that the Dirac-cone dispersion of the topologial surface state is strongly perturbed by hybridization with valence-band states for Bi_{2}Te_{3}-terminated surfaces but remains preserved for MnBi_{2}Te_{4}-terminated surfaces. Our results firmly establish the topologically nontrivial nature of these magnetic van der Waals materials and indicate that the possibility of realizing a quantized anomalous Hall conductivity depends on surface termination.

Image-guided placement of totally implanted vascular access device: retrospective analysis of the clinical outcomes and associated risk factors

OBJECTIVES

To determine risk factors for catheter survival and complications after image-guided implantation of a totally implanted vascular access device (TIVAD).

METHODS

A total of 2883 TIVADs (2735 patients, 63.5±13 years old, 1060 men, 1675 women) implanted under guidance by ultrasound and fluoroscopy in our institution from January 2010 to December 2019 were evaluated retrospectively. We used the log rank test and logistic regression to analyse risk factors associated with catheter survival and complications.

RESULTS

Female patients (n=1778; 61.7%; mean catheter survival days: 780.6 days) and those with a haematological malignancy (n=277; 10.1%; mean catheter survival days: 1019 days) had significantly better catheter survival than male patients (n=1105; 38.3%; mean catheter survival days: 645.9 days) and those with a solid organ malignancy (n=2447; 89.5%; mean catheter survival days: 701 days) (p<0.001 and p=0.003). Patients with haematological malignancies and benign vascular inflammatory disease (n=11; 0.4%) were vulnerable to infection (n=96; 3.3%) (p<0.001 and p=0.004). Thrombotic malfunction (n=38; 1.3%) was significantly more common in females than males (p=0.005). Non-thrombotic malfunction (n=16; 0.6%) showed a significant association with left positioning of the TIVAD (n=410; 14.2%) (p=0.043). Wound dehiscence (n=3; 0.1%) was significantly more frequent in punctured veins other (n=23; 0.8%) than the internal jugular vein (p<0.001).

CONCLUSIONS

Increased attention should be paid to patients with an underlying haematological malignancy, underlying vascular inflammatory disease, female patients, older patients, those accessed via a vein other than the IJV, those with left positioning of the TIVAD system or those with a prolonged TIVAD maintenance.

A compact and stable incidence-plane-rotating second harmonics detector

We describe a compact and stable setup for detecting the optical second harmonics, in which the incident plane rotates with respect to the sample. The setup is composed of rotating Fresnel rhomb optics and a femtosecond ytterbium-doped fiber laser source operating at the repetition frequency of 10 MHz. The setup including the laser source occupies an area of 1 m² and is stable so that the intensity fluctuation of the laser harmonics can be less than 0.2% for 4 h. We present the isotropic harmonic signal of a gold mirror of 0.5 pW and demonstrate the integrity and sensitivity of the setup. We also show the polarization-dependent six-fold pattern of the harmonics of a few-layer WSe₂, from which we infer the degree of local-field effects. Finally, we describe the extensibility of the setup to investigate the samples in various conditions such as cryogenic, strained, ultrafast non-equilibrium, and high magnetic fields.

Bacteriocin production by Leuconostoc citreum ST110LD isolated from organic farm soil, a promising biopreservative

AIMS

The objective of this study was to isolate a bacteriocin-producing strain and to characterize the expressed bacteriocin for the control of Listeria monocytogenes with aim of biopreservation application.

METHODS AND RESULTS

Soil samples from a Korean organic farm were subjected to microbiological analysis for isolation of potential bacteriocinogenic LAB, based on a three-level approach, using L. monocytogenes ATCC 15313 as an indicator test micro-organism. From a total of 17 isolates with inhibitory potential, seven were confirmed to be bacteriocin producers. The selected isolates were differentiated based on their morphology, catalase reaction, sugar fermentation profile obtained by API50CHL and by RAPD-PCR generating two unique profiles. One of the isolates, ST110LD, a specific strong producer of anti-Listeria bacteriocins (12 800 AU ml^-1 ) was identified as Leuconostoc citreum. The proteinaceous nature of the inhibitory compound produced by Leuc. citreum ST110LD was confirmed through treatment with pepsin and α-chymotrypsin. Bacteriocin activity was observed to be not affected by the presence of milk, NaCl, SDS, Tween 80 or glycerol. Bacteriocin ST110LD effectively inhibited the growth of exponentially growing L. monocytogenes ATCC 15313 during a 10-h incubation period in BHI at 37°C. In addition, this bacteriocin showed specific inhibition of only Listeria spp., but did not inhibit the growth of beneficial cultures included in the microbial test panel for assessment of the spectrum of activity.

CONCLUSIONS

Leuconostoc citreum ST110LD was evaluated as safe bacterium strain, producing bacteriocin with high specificity against listerial and enterococcal species. Specificity of producer strain and expressed bacteriocin can be explored in biopreservation of different fermented food products or applied in biotherapy of antibiotic resistant listerial or enterococcal infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

To the best of our knowledge, this is the first report of bacteriocin produced by Leuc. citreum strain with highly specific antimicrobial activity against Listeria sp. and Enterococcus sp.

Relationship between tumor cell infiltration and 5-aminolevulinic acid fluorescence signals after resection of MR-enhancing lesions and its prognostic significance in glioblastoma

PURPOSE

This study investigated the degree of tumor cell infiltration in the tumor cavity and ventricle wall based on fluorescent signals of 5-aminolevulinic acid (5-ALA) after removal of the magnetic resonance (MR)-enhancing area and analyzed its prognostic significance in glioblastoma.

METHODS

Twenty-five newly developed isocitrate dehydrogenase (IDH)-wildtype glioblastomas with complete resection both of MR-enhancing lesions and strong purple fluorescence on resection cavity were retrospectively analyzed. The fluorescent signals of 5-ALA were divided into strong purple, vague pink, and blue colors. The pathologic findings were classified into massively infiltrating tumor cells, infiltrating tumor cells, suspicious single-cell infiltration, and normal-appearing cells. The pathological findings were analyzed according to the fluorescent signals in the resection cavity and ventricle wall.

RESULTS

There was no correlation between fluorescent signals and infiltrating tumor cells in the resection cavity (p = 0.199) and ventricle wall (p = 0.704) after resection of the MR-enhancing lesion. The median progression-free survival (PFS) and median overall survival (OS) were 12.5 (± 2.1) and 21.1 (± 3.5) months, respectively. In univariate analysis, the presence of definitive infiltrating tumor cells in the resection cavity and ventricle wall was significantly related to the PFS (p = 0.002) and OS (p = 0.027). In multivariate analysis, the absence of definitive infiltrating tumor cells improved PFS (hazard ratio: 0.184; 95% CI: 0.049-0.690, p = 0.012) and OS (hazard ratio: 0.124; 95% CI: 0.015-0.998, p = 0.050).

CONCLUSIONS

After resection both of the MR-enhancing lesions and strong purple fluorescence on resection cavity, there was no correlation between remnant fluorescent signals and infiltrating tumor cells. The remnant definitive infiltrating tumor cells in the resection cavity and ventricle wall significantly influenced the prognosis of patients with glioblastoma. Aggressive surgical removal of infiltrating tumor cells may improve their prognosis.

Paired EMI-HIMU hotspots in the South Atlantic-Starting plume heads trigger compositionally distinct secondary plumes?

Age-progressive volcanism is generally accepted as the surface expression of deep-rooted mantle plumes, which are enigmatically linked with the African and Pacific large low-shear velocity provinces (LLSVPs). We present geochemical and geochronological data collected from the oldest portions of the age-progressive enriched mantle one (EMI)-type Tristan-Gough track. They are part of a 30- to 40-million year younger age-progressive hotspot track with St. Helena HIMU (high time-integrated 238U/204Pb) composition, which is also observed at the EMI-type Shona hotspot track in the southernmost Atlantic. Whereas the primary EMI-type hotspots overlie the margin of the African LLSVP, the HIMU-type hotspots are located above a central portion of the African LLSVP, reflecting a large-scale geochemical zonation. We propose that extraction of large volumes of EMI-type mantle from the margin of the LLSVP by primary plume heads triggered upwelling of HIMU material from a more internal domain of the LLSVP, forming secondary plumes.

Bibliometric analysis of manuscript characteristics that influence citations: A comparison of ten major dermatology journals

BACKGROUND

The number of citations an article receives is a reassuring marker for its influence in the academic world.

OBJECTIVE

We aimed to discover characteristics of dermatology articles that may impact their citation.

METHODS

This cross-sectional study collected and analyzed articles published between January and June 2013 from ten highest impact dermatology journals. The study included manuscript characteristics i.e. the length of an article, the presence of visual aids, accessibility, originality, and clarity. Citation analysis statistics required multiple tools such as linear regression, point-biserial correlation, Spearman's rank-order correlation, and Kruskal-Wallis to determine the association between these study variables and the number of citations of articles.

RESULTS

Of 748 articles included in our study, the number of citations ranged from 0 to 814 (median: 18), with weak positive correlations to the length of manuscript (word count: r_s 0.3, p<0.001; pages: r_s 0.3, p<0.001). Having a structured abstract (r_pb -0.15, p<0.001) and increasing number of references (r_s -0.26, p<0.001) showed a negative correlation. Studies originating in North America were associated with higher citations, followed by Europe and Asia (p<0.001). Review articles had a higher number of citations (p<0.001).

CONCLUSIONS

We found that the number of words and the number of pages within a dermatology manuscript had the strongest positive correlation for a higher citation count. The results of this study can benefit authors who may improve the citation of their articles by utilizing this bibliometric study when assembling their manuscript.

Distribution of bone thickness in the human mandibular ramus - a CBCT-based study

Background

The bone thickness of the human mandibular ramus is an important parameter in mandibular surgeries. The aim of this study was to systematically measure the bicortical bone thickness, the ramus dimensions and the position of the lingula. The measurements were tested on significant correlations to the patients’ parameters.

Methods

Based on CBCT scans 150 rami were reconstructed as 3D polygon surfaces. An anatomical grid was adapted to the ramus surface to mark the bone thickness measurement points and to achieve comparability between the measurements on different mandibles. The bone thickness, ramus height, ramus width and the gonion angle were measured. A cluster analysis was performed with these parameters to identify clinically relevant groups with anatomical similarities.

Results

The median distribution of the bone thickness was calculated and visualized in a pseudo-colour map. The mean ramus height was 44.78 mm, the mean width was 31.31 mm and the mean gonion angle was 124.8°. The average distance from the lingula to the dorsal tangent was 53% of the total width and its distance to the caudal tangent was 65% of the total height. Significant correlations between the bone thickness and the ramus proportions could be identified. Age and sex had no significant influence on the mean bone thickness. The measured rami could be divided into two groups by cluster analysis.

Conclusion

The dimensions of the human mandibular ramus can be determined from 3D reconstructed surface models from CBCT scans. Measurements could be made comparable by applying an anatomically oriented grid. A cluster analysis allowed the differentiation of two groups with different bone thickness distributions and geometries, which can be used for the optimization of osteosynthesis systems and their precision of adaptation to different ramus morphologies.