Volumetric brain MRI signatures of heart failure with preserved ejection fraction in the setting of dementia

Heart failure with preserved ejection fraction (HFpEF) is an important, emerging risk factor for dementia, but it is not clear whether HFpEF contributes to a specific pattern of neuroanatomical changes in dementia. A major challenge to studying this is the relative paucity of datasets of patients with dementia, with/without HFpEF, and relevant neuroimaging. We sought to demonstrate the feasibility of using modern data mining tools to create and analyze clinical imaging datasets and identify the neuroanatomical signature of HFpEF-associated dementia. We leveraged the bioinformatics tools at Vanderbilt University Medical Center to identify patients with a diagnosis of dementia with and without comorbid HFpEF using the electronic health record. We identified high resolution, clinically-acquired neuroimaging data on 30 dementia patients with HFpEF (age 76.9 ± 8.12 years, 61% female) as well as 301 age- and sex-matched patients with dementia but without HFpEF to serve as comparators (age 76.2 ± 8.52 years, 60% female). We used automated image processing pipelines to parcellate the brain into 132 structures and quantify their volume. We found six regions with significant atrophy associated with HFpEF: accumbens area, amygdala, posterior insula, anterior orbital gyrus, angular gyrus, and cerebellar white matter. There were no regions with atrophy inversely associated with HFpEF. Patients with dementia and HFpEF have a distinct neuroimaging signature compared to patients with dementia only. Five of the six regions identified in are in the temporo-parietal region of the brain. Future studies should investigate mechanisms of injury associated with cerebrovascular disease leading to subsequent brain atrophy.

Metabolic habitat imaging with hemodynamic heterogeneity predicts individual progression-free survival in high-grade glioma

AIM

We design a feasibility study to obtain a set of metabolic-hemodynamic habitats for tackling tumor spatial metabolic patterns with hemodynamic information.

MATERIALS AND METHODS

Preoperative data from 69 high-grade gliomas (HGG) patients with subsequent histologic confirmation of HGG were prospectively collected (January 2016 to March 2020) after concurrent chemoradiotherapy (CCRT). Four vascular habitats were automatically segmented by multiparametric magnetic resonance imaging (MRI). The metabolic information, either at enhancing or edema tumor regions, was obtained by two neuroradiologists. The relative habitat volumes were used for weight estimation procedures for computing the coefficients of a linear regression model using weighted least squares (WLS) for metabolite semiquantifications (i.e. the Cho/NAA ratio and the Cho/Cr ratio) at vascular habitats. Multivariate Cox proportional hazard regression analyses are used to obtain the odds ratio (OR) and develop a nomogram using weighted estimators corresponding to each covariate derived from Cox regression coefficients.

RESULTS

There was a strongly correlation between perfusion indexes and the Cho/Cr ratio (rCBV, r=0.71) or Cho/NAA ratio (rCBV, r=0.66) at high-angiogenic enhancing tumor habitats (HAT) habitat. Compared isocitrate dehydrogenase (IDH) mutation to their wild type, the IDH wild type had significantly decreased Cho/Cr ratio (IDH mutation: Cho/Cr ratio = 2.44 ± 0.33, IDH wildtype: Cho/Cr ratio = 2.66 ± 0.36, p=0.02) and Cho/NAA ratio (IDH mutation: Cho/Cr ratio = 4.59 ± 0.61, IDH wildtype: Cho/Cr ratio = 4.99 ± 0.66, p=0.022) at the HAT. The C-index for the median progression-free survival (PFS) prediction was 0.769 for the Cho/NAA nomogram and 0.747 for the Cho/Cr nomogram through 1000 bootstrapping validation.

CONCLUSIONS

Our findings suggest that spatial metabolism combined with hemodynamic heterogeneity is associated with individual PFS to HGG patients post-CCRT.

Longitudinal Assessment of Pancreas Volume by MRI Predicts Progression to Stage 3 Type 1 Diabetes

OBJECTIVE

This multicenter prospective cohort study compared pancreas volume as assessed by MRI, metabolic scores derived from oral glucose tolerance testing (OGTT), and a combination of pancreas volume and metabolic scores for predicting progression to stage 3 type 1 diabetes (T1D) in individuals with multiple diabetes-related autoantibodies.

RESEARCH DESIGN AND METHODS

Pancreas MRI was performed in 65 multiple autoantibody-positive participants enrolled in the Type 1 Diabetes TrialNet Pathway to Prevention study. Prediction of progression to stage 3 T1D was assessed using pancreas volume index (PVI), OGTT-derived Index60 score and Diabetes Prevention Trial-Type 1 Risk Score (DPTRS), and a combination of PVI and DPTRS.

RESULTS

PVI, Index60, and DPTRS were all significantly different at study entry in 11 individuals who subsequently experienced progression to stage 3 T1D compared with 54 participants who did not experience progression (P < 0.005). PVI did not correlate with metabolic testing across individual study participants. PVI declined longitudinally in the 11 individuals diagnosed with stage 3 T1D, whereas Index60 and DPTRS increased. The area under the receiver operating characteristic curve for predicting progression to stage 3 from measurements at study entry was 0.76 for PVI, 0.79 for Index60, 0.79 for DPTRS, and 0.91 for PVI plus DPTRS.

CONCLUSIONS

These findings suggest that measures of pancreas volume and metabolism reflect distinct components of risk for developing stage 3 type 1 diabetes and that a combination of these measures may provide superior prediction than either alone.

Graph Autoencoders for Embedding Learning in Brain Networks and Major Depressive Disorder Identification

Brain functional connectivity (FC) networks inferred from functional magnetic resonance imaging (fMRI) have shown altered or aberrant brain functional connectome in various neuropsychiatric disorders. Recent application of deep neural networks to connectome-based classification mostly relies on traditional convolutional neural networks (CNNs) using input FCs on a regular Euclidean grid to learn spatial maps of brain networks neglecting the topological information of the brain networks, leading to potentially sub-optimal performance in brain disorder identification. We propose a novel graph deep learning framework that leverages non-Euclidean information inherent in the graph structure for classifying brain networks in major depressive disorder (MDD). We introduce a novel graph autoencoder (GAE) architecture, built upon graph convolutional networks (GCNs), to embed the topological structure and node content of large fMRI networks into low-dimensional representations. For constructing the brain networks, we employ the Ledoit-Wolf (LDW) shrinkage method to efficiently estimate high-dimensional FC metrics from fMRI data. We explore both supervised and unsupervised techniques for graph embedding learning. The resulting embeddings serve as feature inputs for a deep fully-connected neural network (FCNN) to distinguish MDD from healthy controls (HCs). Evaluating our model on resting-state fMRI MDD dataset, we observe that the GAE-FCNN outperforms several state-of-the-art methods for brain connectome classification, achieving the highest accuracy when using LDW-FC edges as node features. The graph embeddings of fMRI FC networks also reveal significant group differences between MDD and HCs. Our framework demonstrates the feasibility of learning graph embeddings from brain networks, providing valuable discriminative information for diagnosing brain disorders.

[Analysis of ultrasound images features and diagnostic model establishment of alveolar soft part sarcoma and intramuscular capillary-type hemangiomas]

Objective: The ultrasonography features of alveolar soft part sarcoma (ASPS) and intramuscular capillary-type hemangiomas (ICTH) were analyzed, and the diagnostic model of ASPS was established. Methods: A cross-sectional study was carried out. The clinical data of 52 patients [28 males and 24 females, aged (20.7±15.1) years] with pathologically confirmed ASPS and ICTH admitted to People's Hospital of Henan Province from January 2005 to February 2023 were included in the study. According to pathological types, the patients were divided into ASPS group and ICTH group. Clinical data of patients were retrospectively collected, and meaningful indicators in the univariate analysis were included in the regression analysis for screening. After comprehensive consideration of clinical significance and statistical significance, eligible indicators were selected for inclusion in the regression analysis. Binary logistic regression analysis was used to screen the factors that distinguished the pathological types of ASPS and ICTH, and the diagnostic model was established. The area under receiver operating characteristic (ROC) curve (AUC) was used to evaluate the diagnostic effectiveness of the diagnostic model in distinguishing ASPS from ICTH. Results: There were 20 patients in ASPS group, 10 males and 10 females, aged (26.9±13.5) years, and 32 patients in ICTH group, 18 males and 14 females, aged (16.8±15.0) years. The age difference between the ASPS group and the ICTH group was statistically significant (P<0.05), and there were statistically significant differences in the ultrasound imaging features of "clear boundary" "peripheral lobe" "thin blood vessels inside the lesion are straight and out of shape" "intra-lesion liquification" "peripheral thick blood vessels" and "peripheral muscle fiber disruption" between the two groups (all P<0.001).Variables with clinical and statistical significance were selected as independent variables. Binary logistic regression analysis showed that peripheral muscle fiber interruption (OR=97.358, 95%CI:6.833-1 387.249) and internal thin blood vessels were flat and out of shape (OR=0.052, 95%CI:0.003-0.921) was the correlation factor to distinguish the pathological types of ASPS and ICTH. Two ultrasonic image features of "peripheral muscle fiber interruption" and "internal thin blood vessels are straight and out of shape" were used to establish the diagnostic model. The sensitivity of "peripheral muscle fiber interruption" diagnostic model was 81.3%, and the specificity was 95.0%. The AUC was 0.811(95%CI: 0.761-0.954). The sensitivity, specificity and AUC of the diagnosis model of "internal thin vessels with flat misshape" were 90.0%, 96.9% and 0.934(95%CI: 0.830-0.984). The sensitivity, specificity and AUC of the combined diagnosis model of "peripheral muscle fiber interruption" and "internal thin blood vessel straight out of shape" were 96.9%, 90.0% and 0.974(95%CI:0.877-0.999). Conclusion: Ultrasonography can be used to distinguish ASPS from ICTH, and the combined diagnostic model based on the two ultrasonic imaging features of "peripheral muscle fiber interruption" and "internal thin blood vessel straight out of shape" can further improve the diagnostic efficiency.

Polyethylene Glycol-Mediated Axonal Fusion Promotes Early Sensory Recovery After Digital Nerve Injury: A Randomized Clinical Trial

BACKGROUND

Peripheral nerve repair is limited by Wallerian degeneration coupled with the slow and inconsistent rates of nerve regrowth. In more proximal injuries, delayed nerve regeneration can cause debilitating muscle atrophy. Topical application of polyethylene glycol (PEG) during neurorrhaphy facilitates the fusion of severed axonal membranes, immediately restoring action potentials across the coaptation site. In preclinical animal models, PEG-fusion resulted in remarkable early functional recovery.

METHODS

This is the first randomized clinical trial comparing functional outcomes between PEG-fusion and standard neurorrhaphy. Participants with digital nerve transections were followed up at 2 weeks, 1 month, and 3 months postoperatively. The primary outcome was assessed using the Medical Research Council Classification (MRCC) rating for sensory recovery at each timepoint. Semmes-Weinstein monofilaments and static two-point discrimination determined MRCC ratings. Postoperative quality of life was measured using the Michigan Hand Questionnaire (MHQ).

RESULTS

Forty-eight transected digital nerves (25 control, 23 PEG) across twenty-two patients were analyzed. PEG-fused nerves demonstrated significantly higher MRCC scores at 2 weeks (OR 16.95, 95% CI: 1.79 - 160.38, p = 0.008) and 1 month (OR 13.40, 95% CI: 1.64 - 109.77, p = 0.009). Participants in the PEG cohort also had significantly higher average MHQ scores at 2 weeks (Hodge's g 1.28, 95% CI: 0.23 - 2.30, p = 0.0163) and 1 month (Hodge's g 1.02, 95% CI: 0.04 - 1.99, p = 0.049). No participants had adverse events related to the study drug.

CONCLUSION

PEG-fusion promotes early sensory recovery and improved patient well-being following peripheral nerve repair of digital nerves.

Different tumor growth pattern of clinically nonfunctioning pituitary neuroendocrine tumor according to sex and age: a longitudinal study

PURPOSE

Asymptomatic patients with clinically non-functional pituitary neuroendocrine tumors (CNF-PitNETs) are usually followed up. However, the natural course of CNF-PitNETs according to sex and age remains unclear. Therefore, this study assessed growth patterns of CNF-PitNETs according to sex and age.

METHODS

In this longitudinal study, we enrolled 431 consecutive patients with CNF-PitNETs who were treated at Seoul National University Hospital from 1997 to 2021. The patients underwent hormone function testing and visual field testing, and were subsequently followed up with imaging over a median duration of 66 months.

RESULTS

The median age of the patients was 53.0 years, and 37.1% (n = 160) were men. Men were older and harbored more macroadenomas than women. The annual tumor volume change was higher in men than in women (0.21 vs. 0.04 cm3/year, P < 0.001). The estimated cutoff value of age for significant tumor growth was 51 years. In men, the annual tumor volume change was similar across all age groups. In women, those aged ≤ 50 years showed significantly lower annual tumor volume change than those aged > 50 years (0.01, 0.11, and 0.17 cm3/year, P = 0.001). When comparing sexes within the same age group, the annual tumor volume changes was significantly lower for women than for men, only in patients aged ≤ 50 years (0.01 vs. 0.15 cm3/year, P < 0.001).

CONCLUSIONS

Among patients with CNF-PitNET, tumor growth was slower in women aged ≤ 50 years than in men and women aged > 50. These findings may guide the customization of surveillance strategies for CNF-PitNETs according to sex and age.

Multimodel habitats constructed by perfusion and/or diffusion MRI predict isocitrate dehydrogenase mutation status and prognosis in high-grade gliomas

AIM

To determine whether tumour vascular and cellular heterogeneity of high-grade glioma (HGG) is predictive of isocitrate dehydrogenase (IDH) mutation status and overall survival (OS) by using tumour habitat-based analysis constructed by perfusion and/or diffusion magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Seventy-eight HGG patients that met the 2021 World Health Organization WHO Classification of Tumors of the Central Nervous System, 5th edition (WHO CNS5), were enrolled to predict IDH mutation status, of which 32 grade 4 patients with unmethylated O6-methylguanine-DNA methyltransferase (MGMT) promoter were enrolled for prognostic analysis. The deep-learning-based model nnU-Net and K-means clustering algorithm were applied to construct the Traditional Habitat, Vascular Habitat (VH), Cellular Density Habitat (DH), and their Combined Habitat (CH). Quantitative parameters were extracted and compared between IDH-mutant and IDH-wild-type patients, respectively, and the prediction potential was evaluated by receiver operating characteristic (ROC) curve analysis. OS was analysed using Kaplan-Meier survival analysis and the log-rank test.

RESULTS

Compared with IDH-mutants, median relative cerebral blood volume (rCBVmedian) values in the whole enhancing tumour (WET), VH1, VH3, CH1-4 habitats were significantly increased in IDH-wild-type HGGs (all p<0.05). Additionally, the accuracy of rCBVmedian values in CH1 outperformed other habitats in identifying IDH mutation status (p<0.001) at a cut-off value of 4.83 with AUC of 0.815. Kaplan-Meier survival analysis highlighted significant differences in OS between the populations dichotomised by the median of rCBVmedian in WET, VH1, CH1-3 habitats (all p<0.05).

CONCLUSIONS

The habitat imaging technique may improve the accuracy of predicting IDH mutation status and prognosis, and even provide a new direction for subsequent personalised precision treatment.

Accentuated Paralimbic and Reduced Mesolimbic D2/3-Impulsivity Associations in Parkinson's Disease

Impulsivity is a behavioral trait that is elevated in many neuropsychiatric disorders. Parkinson's disease (PD) patients can exhibit a specific pattern of reward-seeking impulsive-compulsive behaviors (ICBs), as well as more subtle changes to generalized trait impulsivity. Prior studies in healthy controls (HCs) suggest that trait impulsivity is regulated by D2/3 autoreceptors in mesocorticolimbic circuits. While altered D2/3 binding is noted in ICB+ PD patients, there is limited prior assessment of the trait impulsivity-D2/3 relationship in PD, and no prior direct comparison with patterns in HCs. We examined 54 PD (36 M; 18 F) and 31 sex- and age-matched HC (21 M; 10 F) subjects using [18F]fallypride, a high-affinity D2/3 receptor ligand, to measure striatal and extrastriatal D2/3 nondisplaceable binding potential (BPND). Subcortical and cortical assessment exclusively used ROI or exploratory-voxelwise methods, respectively. All completed the Barratt Impulsiveness Scale, a measure of trait impulsivity. Subcortical ROI analyses indicated a negative relationship between trait impulsivity and D2/3 BPND in the ventral striatum and amygdala of HCs but not in PD. By contrast, voxelwise methods demonstrated a positive trait impulsivity-D2/3 BPND correlation in ventral frontal olfactocentric-paralimbic cortex of subjects with PD but not HCs. Subscale analysis also highlighted different aspects of impulsivity, with significant interactions between group and motor impulsivity in the ventral striatum, and attentional impulsivity in the amygdala and frontal paralimbic cortex. These results suggest that dopamine functioning in distinct regions of the mesocorticolimbic circuit influence aspects of impulsivity, with the relative importance of regional dopamine functions shifting in the neuropharmacological context of PD.SIGNIFICANCE STATEMENT The biological determinants of impulsivity have broad clinical relevance, from addiction to neurodegenerative disorders. Here, we address biomolecular distinctions in Parkinson's disease. This is the first study to evaluate a large cohort of Parkinson's disease patients and age-matched healthy controls with a measure of trait impulsivity and concurrent [18F]fallypride PET, a method that allows quantification of D2/3 receptors throughout the mesocorticolimbic network. We demonstrate widespread differences in the trait impulsivity-dopamine relationship, including (1) loss of subcortical relationships present in the healthy brain and (2) emergence of a new relationship in a limbic cortical area. This illustrates the loss of mechanisms of behavioral regulation present in the healthy brain while suggesting a potential compensatory response and target for future investigation.

Genetic risk converges on regulatory networks mediating early type 2 diabetes

Type 2 diabetes mellitus (T2D), a major cause of worldwide morbidity and mortality, is characterized by dysfunction of insulin-producing pancreatic islet β cells1,2. T2D genome-wide association studies (GWAS) have identified hundreds of signals in non-coding and β cell regulatory genomic regions, but deciphering their biological mechanisms remains challenging3-5. Here, to identify early disease-driving events, we performed traditional and multiplexed pancreatic tissue imaging, sorted-islet cell transcriptomics and islet functional analysis of early-stage T2D and control donors. By integrating diverse modalities, we show that early-stage T2D is characterized by β cell-intrinsic defects that can be proportioned into gene regulatory modules with enrichment in signals of genetic risk. After identifying the β cell hub gene and transcription factor RFX6 within one such module, we demonstrated multiple layers of genetic risk that converge on an RFX6-mediated network to reduce insulin secretion by β cells. RFX6 perturbation in primary human islet cells alters β cell chromatin architecture at regions enriched for T2D GWAS signals, and population-scale genetic analyses causally link genetically predicted reduced RFX6 expression with increased T2D risk. Understanding the molecular mechanisms of complex, systemic diseases necessitates integration of signals from multiple molecules, cells, organs and individuals, and thus we anticipate that this approach will be a useful template to identify and validate key regulatory networks and master hub genes for other diseases or traits using GWAS data.

Cognitive, Disability, and Treatment Outcome Implications of Symptom-Based Phenotyping in Late-Life Depression

OBJECTIVE

Late-life depression is associated with substantial heterogeneity in clinical presentation, disability, and response to antidepressant treatment. We examined whether self-report of severity of common symptoms, including anhedonia, apathy, rumination, worry, insomnia, and fatigue were associated with differences in presentation and response to treatment. We also examined whether these symptoms improved during treatment with escitalopram.

DESIGN

Eighty-nine older adults completed baseline assessments, neuropsychological testing and providing self-reported symptom and disability scales. They then entered an 8-week, placebo-controlled randomized trial of escitalopram, and self-report scales were repeated at the trial's end. Raw symptom scale scores were combined into three standardized symptom phenotypes and models examined how symptom phenotype severity was associated with baseline measures and depression improvement over the trial.

RESULTS

While rumination/worry appeared independent, severity of apathy/anhedonia and fatigue/insomnia were associated with one another and with greater self-reported disability. Greater fatigue/insomnia was also associated with slower processing speed, while rumination/worry was associated with poorer episodic memory. No symptom phenotype severity score predicted a poorer overall response to escitalopram. In secondary analyses, escitalopram did not improve most phenotypic symptoms more than placebo, aside for greater reductions in worry and total rumination severity.

CONCLUSION

Deeper symptom phenotype characterization may highlight differences in the clinical presentation of late-life depression. However, when compared to placebo, escitalopram did not improve many of the symptoms assessed. Further work is needed to determine whether symptom phenotypes inform longer-term course of illness, and which treatments may best benefit specific symptoms.

The Role of a Dopamine-Dependent Limbic-Motor Network in Sensory Motor Processing in Parkinson Disease

Limbic and motor integration is enabled by a mesial temporal to motor cortex network. Parkinson disease (PD) is characterized by a loss of dorsal striatal dopamine but relative preservation of mesolimbic dopamine early in disease, along with changes to motor action control. Here, we studied 47 patients with PD using the Simon conflict task and [18F]fallypride PET imaging. Additionally, a cohort of 16 patients participated in a single-blinded dextroamphetamine (dAMPH) study. Task performance was evaluated using the diffusion model for conflict tasks, which allows for an assessment of interpretable action control processes. First, a voxel-wise examination disclosed a negative relationship, such that longer non-decision time is associated with reduced D2-like binding potential (BPND) in the bilateral putamen, left globus pallidus, and right insula. Second, an ROI analysis revealed a positive relationship, such that shorter non-decision time is associated with reduced D2-like BPND in the amygdala and ventromedial OFC. The difference in non-decision time between off-dAMPH and on-dAMPH trials was positively associated with D2-like BPND in the globus pallidus. These findings support the idea that dysfunction of the traditional striatal-motor loop underlies action control deficits but also suggest that a compensatory parallel limbic-motor loop regulates motor output.

Exocrine pancreas in type 1 and type 2 diabetes: different patterns of fibrosis, metaplasia, angiopathy, and adiposity

The endocrine and exocrine compartments of the pancreas are spatially related but functionally distinct. Multiple diseases affect both compartments, including type 1 diabetes (T1D), pancreatitis, cystic fibrosis, and pancreatic cancer. To better understand how the exocrine pancreas changes with age, obesity, and diabetes, we performed systematic analysis of wellpreserved tissue sections from the pancreatic head, body, and tail of organ donors with T1D (n = 20), type 2 diabetes (T2D, n = 25), and donors with no diabetes (ND, n = 74). Among ND donors, we found that acinar-to-ductal metaplasia (ADM), angiopathy, and pancreatic adiposity increased with age, while ADM and adiposity also increased with BMI. Compared to age- and sex-matched ND organs, T1D pancreata had greater acinar atrophy and angiopathy with fewer intralobular adipocytes. T2D pancreata had greater ADM, angiopathy, and total T lymphocytes, but no difference in adipocyte number, compared to ND organs. While total pancreatic fibrosis was increased in both T1D and T2D, the pattern was different with T1D pancreata having greater periductal and perivascular fibrosis, whereas T2D pancreata had greater lobular and parenchymal fibrosis. Thus, the exocrine pancreas undergoes distinct changes as individuals age or develop T1D or T2D.

Influences of resting-state intrinsic functional brain connectivity on the antidepressant treatment response in late-life depression

BACKGROUND

Late-life depression (LLD) is characterized by differences in resting state functional connectivity within and between intrinsic functional networks. This study examined whether clinical improvement to antidepressant medications is associated with pre-randomization functional connectivity in intrinsic brain networks.

METHODS

Participants were 95 elders aged 60 years or older with major depressive disorder. After clinical assessments and baseline MRI, participants were randomized to escitalopram or placebo with a two-to-one allocation for 8 weeks. Non-remitting participants subsequently entered an 8-week trial of open-label bupropion. The main clinical outcome was depression severity measured by MADRS. Resting state functional connectivity was measured between a priori key seeds in the default mode (DMN), cognitive control, and limbic networks.

RESULTS

In primary analyses of blinded data, lower post-treatment MADRS score was associated with higher resting connectivity between: (a) posterior cingulate cortex (PCC) and left medial prefrontal cortex; (b) PCC and subgenual anterior cingulate cortex (ACC); (c) right medial PFC and subgenual ACC; (d) right orbitofrontal cortex and left hippocampus. Lower post-treatment MADRS was further associated with lower connectivity between: (e) the right orbitofrontal cortex and left amygdala; and (f) left dorsolateral PFC and left dorsal ACC. Secondary analyses associated mood improvement on escitalopram with anterior DMN hub connectivity. Exploratory analyses of the bupropion open-label trial associated improvement with subgenual ACC, frontal, and amygdala connectivity.

CONCLUSIONS

Response to antidepressants in LLD is related to connectivity in the DMN, cognitive control and limbic networks. Future work should focus on clinical markers of network connectivity informing prognosis.

REGISTRATION

ClinicalTrials.gov NCT02332291.

Racial Differences in the Presentation and Progression of Huntington's Disease

BACKGROUND

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease that predominantly impacts a Caucasian population, but few efforts have explored racial differences in presentation and progression.

OBJECTIVE

The aim was to assess the presentation and progression of HD across race groups using the Enroll-HD longitudinal observational study.

METHODS

We applied propensity score matching for cytosine-adenine-guanine age product score, and age, to identify White, Hispanic, Asian, and Black participants from the Enroll-HD database. We compared clinical presentations at baseline, and progression over time, using White participants as a control cohort.

RESULTS

Black participants were more severe at baseline across all clinical measures. No significant differences in progression were observed between race groups.

CONCLUSIONS

We consider the factors driving clinical differences at baseline for Black participants. Our data emphasize the necessary improvement in underrepresented minority recruitment for studies of rare diseases. © 2023 International Parkinson and Movement Disorder Society.

Incidence, Radiologic and Dosimetric Parameters Associated with Radiation Induced Breast Lymphedema

PURPOSE/OBJECTIVE(S)

Radiation induced breast lymphedema (BL) is an underreported but common finding. This study aimed to report the incidence of clinical BL and investigate the radiologic and dosimetric parameters associated with higher risk of BL.

MATERIALS/METHODS

This IRB approved study included women with breast cancer who underwent breast conservative surgery followed by adjuvant radiation therapy between 2019 and 2021 at our institution. We reviewed the eligible patients' charts for incidence of clinical BL resulting in symptoms and requiring physical therapy referral. Thickness of the skin at defined center and bottom points of the breast was measured for patient' baseline and follow up mammograms. Dosimetric parameters were imported from patients' radiation plans including mean, maximum doses, and volumes receiving 20, 30, 40, & 50 Gy (V20, V30, V40, & V50), of the whole breast (WB), breast_eval (BE), and breast skin (BS) (defined as the superficial 5 mm of the skin). A chi-square test was used to test the association between clinical BL and radiation treatment regimens and beam energies and the association of skin thicknesses between those who had clinical BL and those who did not. A Wilcoxon rank sum test was used to test the association of the dosimetric parameters with clinical BL.

RESULTS

We identified 268 patients who were eligible for the study. After chart and radiologic review, 119 patients had complete records available and were included in this study. Twenty-nine patients (24.4%) of the patients presented with symptomatic BL. Most patients (68%) received hypofractionated (42.56 Gy with or without 10 Gy boost), while 25% received conventional and 7% received ultra-hypofractionated radiotherapy. There was no association between the fractionation and incidence of BL (p = 0.4). There was no association between breast size and BL (mean 1065 cc vs 1232 cc, p = 0.35). There was significant association between BL and BS V30 (142cc vs 162 cc, p = 0.02), and BS V40 (82 cc vs 102 cc, p = 0.02), and a trend towards significant association with BS V20 (172cc vs. 193cc, p = 0.08), BS V50 (8 cc vs. 16 cc, p = 0.06). There was no significant association between BL and BS mean dose (36.9 Gy vs 39 Gy p = 0.11), or BS max dose (53.9 Gy vs 54.1 Gy, p = 0.21). None of the dosimetric parameters of WB and BE had significant association with clinical BL. Utilizing ROC analysis, there was significant association between clinical BL and the change of baseline mammogram breast skin thickness and skin thickness at 6 months follow up mammograms (+13 mm center point p = 0.04, +9 mm bottom point p<0.5), and at 12 months mammograms (+15 mm center point p<0.5, +11 mm bottom point p<0.5).

CONCLUSION

Almost 1 in 4 women experienced radiation induced BL in our cohort. BS V30 & V40 are significantly associated with higher risk of BL. There was significant association between increased skin thickening in 6- and 12-months follow up mammograms and BL. Further analysis will follow to assess the association between surgical and clinical characteristics and BL.

Clinical Outcomes with Stereotactic Body Radiation Therapy for Oligometastatic Prostate Cancer: Results from a Prospective Registry Trial

PURPOSE/OBJECTIVE(S)

Metastasis-directed radiation therapy using stereotactic body radiation therapy (SBRT) in oligometastatic prostate cancer (Oligo PCa) has a demonstrated benefit for local control and biochemical recurrence free survival for men with oligorecurrent PCa; however, the impact of SBRT within other oligometastatic states and in the context of systemic therapy remains poorly characterized. In this study, we investigate prognostic factors for clinical outcomes in a prospective cohort of Oligo PCa patients treated with metastasis-directed SBRT.

MATERIALS/METHODS

Using a single-institution registry trial, we analyzed a prospective cohort of 86 patients with Oligo PCa (≤5 metastatic lesions) and treated with metastasis-directed SBRT between 2017- 2022. Patients were classified as synchronous, metachronous, or induced oligometastatic disease as per the ESTRO guidelines. We evaluated the time to radiographic progression (TTRP), defined as the time from SBRT start date to radiographic progression, as well as time to initiation of new treatment (TTNT), defined as the time from SBRT end date to initiation of new therapy (systemic or radiation therapy). Time to event (TTE) was defined as the time from SBRT start date to radiographic progression or initiation of new therapy, whichever occurred first. Patients without documented events were censored at the date of last disease assessment. Comparative analyses were performed using Kaplan-Meier and Cox proportional hazards regression methods.

RESULTS

Eighty-six men with Oligo PCa treated with SBRT were followed for a median of 16.4 months with M0 (73%), Oligo PCa (21%) or polymetastatic PCa (6%) GS > = 8 (63%) at initial diagnosis. At the time of treatment with initial SBRT, 21% had synchronous oligometastatic disease, 63% had metachronous or repeat oligorecurrence or oligoprogression, and 16% had induced oligometastatic disease. Most patients were treated to 1-3 sites (94%), which predominantly included bone (86%), and the median dose was 35 Gy/5F. Concurrent systemic therapy during SBRT was seen in 85% of patients, including (60.5% with new generation androgen receptor signaling inhibitors). Overall survival at 1-year and 2-years was 96.9% [95% CI, 88.2-99.2%] and 94.4% [95% CI, 83.2-98.2%]. Using univariable analysis, those who did not receive systemic treatment during SBRT had significantly shorter TTRP (HR 3.67, [95% CI, 1.62-8.32], p = 0.002), TTNT (HR 3.24, 95% CI [1.49-7.06], p = 0.003), and TTE (HR 3.05, [95% CI, 1.44-6.45], p = 0.004). Additionally, patients treated with SBRT for metachronous (HR 2.89, [95% CI 0.68-12.30]) and induced metastatic disease (HR 8.96, [95% CI 1.85-43.37]) had significantly shorter TTE compared to synchronous oligometastatic disease (p = 0.006).

CONCLUSION

Using a prospective registry cohort of men with Oligo PCa treated with SBRT, we identify an association of oligometastatic state and the use of concurrent systemic therapy with improved TTRP and TTNT. Further prospective studies are warranted.

Longitudinal MRI Shows Progressive Decline in Pancreas Size and Altered Pancreas Shape in Type 1 Diabetes

CONTEXT

Individuals with type 1 diabetes (T1D) have a smaller pancreas, but longitudinal changes in pancreas size and shape are unclear.

OBJECTIVE

We monitored changes in pancreas size and shape after diagnosis with T1D.

DESIGN

We conducted a prospective cohort study at an academic medical center between 2014 and 2022.

PATIENTS AND HEALTHY CONTROLS

Individuals with T1D (n = 91) or controls (n = 90) underwent magnetic resonance imaging (MRI) of the pancreas, including longitudinal MRI in 53 individuals with new-onset T1D.

INTERVENTION

Interventions included MRI and continuous glucose monitoring (CGM).

MAIN OUTCOME MEASURES

Pancreas size and shape were measured from MRI. For participants who used CGM, measures of glycemic variability were calculated.

RESULTS

On longitudinal imaging, pancreas volume and pancreas volume index normalized for body weight declined during the first year after diagnosis. Pancreas volume index continued to decline through the fifth year after diagnosis. A cross-sectional study of individuals with diabetes duration up to 60 years demonstrated that pancreas size in adults negatively correlated with age and disease duration, whereas pancreas volume and pancreas volume index remained stable in controls. Pancreas volume index correlated inversely with low blood glucose index, a measure of risk for hypoglycemia. Pancreas shape was altered in individuals with T1D and further diverged from controls over the first 5 years after diagnosis. Pancreas size and shape are altered in nondiabetic individuals at genetic risk for T1D. Combined pancreas size and shape analysis better distinguished the pancreas of individuals with T1D from controls than size alone.

CONCLUSIONS

Pancreas size declines most rapidly near the clinical diagnosis of T1D and continues to decline throughout adulthood. Declines in pancreas size are accompanied by changes in pancreas shape.

Auditory cortex hyperconnectivity before rTMS is correlated with tinnitus improvement

INTRODUCTION

Repetitive transcranial magnetic stimulation (rTMS) has been used as a potential treatment for tinnitus; however, its effectiveness is variable and unpredictable. We hypothesized that resting-state functional connectivity before rTMS may be correlated with rTMS treatment effectiveness.

METHODS

We applied 1-Hz rTMS to the left primary auditory (A1) and dorsolateral prefrontal cortices (DLPFC) of 10 individuals with tinnitus and 10 age-matched controls. Resting-state functional magnetic resonance imaging (fMRI) studies were performed approximately one week before rTMS. Seed-based connectivity analyses were conducted for each individual, with seed regions as rTMS target areas.

RESULTS

Compared to controls, the left superior temporal areas showed significantly increased positive connectivity with the left A1 and negative connectivity with the left DLPFC in the tinnitus group. The left frontoparietal and right cerebellar areas showed significantly increased negative connectivity with the left A1 and positive connectivity with the left DLPFC. Seed-based hyperconnectivity was correlated with tinnitus improvement (pre-rTMS vs. 2-week post-rTMS Tinnitus Handicap Inventory scores). Tinnitus improvement was significantly correlated with left A1 hyperconnectivity; however, no correlation was observed with left DLPFC connectivity. Positive rTMS outcomes were associated with significantly increased positive connectivity in bilateral superior temporal areas and significantly increased negative connectivity in bilateral frontal areas.

CONCLUSIONS

Our results suggest that oversynchronisation of left A1 connectivity before rTMS of the left A1 and DLPFC is associated with treatment effectiveness.

Structural brain differences in essential tremor and Parkinson's disease deep brain stimulation patients

BACKGROUND

Essential tremor (ET) and Parkinson's disease (PD) are the most common tremor disorders and are common indications for deep brain stimulation (DBS). In some patients, PD and ET symptoms overlap and diagnosis can be challenging based on clinical criteria alone. The objective of this study was to identify structural brain differences between PD and ET DBS patients to help differentiate these disorders and improve our understanding of the different brain regions involved in these pathologic processes.

METHODS

We included ET and PD patients scheduled to undergo DBS surgery in this observational study. Patients underwent 3T brain MRI while under general anesthesia as part of their procedure. Cortical thicknesses and subcortical volumes were quantified from T1-weighted images using automated multi-atlas segmentation. We used logistic regression analysis to identify brain regions associated with diagnosis of ET or PD.

RESULTS

149 ET and 265 PD patients were included. Smaller volumes in the pallidum and thalamus and reduced thickness in the anterior orbital gyrus, lateral orbital gyrus, and medial precentral gyrus were associated with greater odds of ET diagnosis. Conversely, reduced volumes in the caudate, amygdala, putamen, and basal forebrain, and reduced thickness in the orbital part of the inferior frontal gyrus, supramarginal gyrus, and posterior cingulate were associated with greater odds of PD diagnosis.

CONCLUSIONS

These findings identify structural brain differences between PD and ET patients. These results expand our understanding of the different brain regions involved in these disorders and suggest that structural MRI may help to differentiate patients with these two disorders.

Corticostriatal beta oscillation changes associated with cognitive function in Parkinson's disease

Cognitive impairment is the most frequent non-motor symptom in Parkinson's disease and is associated with deficits in a number of cognitive functions including working memory. However, the pathophysiology of Parkinson's disease cognitive impairment is poorly understood. Beta oscillations have previously been shown to play an important role in cognitive functions including working memory encoding. Decreased dopamine in motor cortico-striato-thalamo-cortical (CSTC) circuits increases the spectral power of beta oscillations and results in Parkinson's disease motor symptoms. Analogous changes in parallel cognitive CSTC circuits involving the caudate and dorsolateral prefrontal cortex (DLPFC) may contribute to Parkinson's disease cognitive impairment. The objective of our study is to evaluate whether changes in beta oscillations in the caudate and DLPFC contribute to cognitive impairment in Parkinson's disease patients. To investigate this, we used local field potential recordings during deep brain stimulation surgery in 15 patients with Parkinson's disease. Local field potentials were recorded from DLPFC and caudate at rest and during a working memory task. We examined changes in beta oscillatory power during the working memory task as well as the relationship of beta oscillatory activity to preoperative cognitive status, as determined from neuropsychological testing results. We additionally conducted exploratory analyses on the relationship between cognitive impairment and task-based changes in spectral power in additional frequency bands. Spectral power of beta oscillations decreased in both DLPFC and caudate during working memory encoding and increased in these structures during feedback. Subjects with cognitive impairment had smaller decreases in caudate and DLPFC beta oscillatory power during encoding. In our exploratory analysis, we found that similar differences occurred in alpha frequencies in caudate and theta and alpha in DLPFC. Our findings suggest that oscillatory power changes in cognitive CSTC circuits may contribute to cognitive symptoms in patients with Parkinson's disease. These findings may inform the future development of novel neuromodulatory treatments for cognitive impairment in Parkinson's disease.

The Interictal Suppression Hypothesis in focal epilepsy: network-level supporting evidence

Why are people with focal epilepsy not continuously having seizures? Previous neuronal signalling work has implicated gamma-aminobutyric acid balance as integral to seizure generation and termination, but is a high-level distributed brain network involved in suppressing seizures? Recent intracranial electrographic evidence has suggested that seizure-onset zones have increased inward connectivity that could be associated with interictal suppression of seizure activity. Accordingly, we hypothesize that seizure-onset zones are actively suppressed by the rest of the brain network during interictal states. Full testing of this hypothesis would require collaboration across multiple domains of neuroscience. We focused on partially testing this hypothesis at the electrographic network level within 81 individuals with drug-resistant focal epilepsy undergoing presurgical evaluation. We used intracranial electrographic resting-state and neurostimulation recordings to evaluate the network connectivity of seizure onset, early propagation and non-involved zones. We then used diffusion imaging to acquire estimates of white-matter connectivity to evaluate structure-function coupling effects on connectivity findings. Finally, we generated a resting-state classification model to assist clinicians in detecting seizure-onset and propagation zones without the need for multiple ictal recordings. Our findings indicate that seizure onset and early propagation zones demonstrate markedly increased inwards connectivity and decreased outwards connectivity using both resting-state (one-way ANOVA, P-value = 3.13 × 10-13) and neurostimulation analyses to evaluate evoked responses (one-way ANOVA, P-value = 2.5 × 10-3). When controlling for the distance between regions, the difference between inwards and outwards connectivity remained stable up to 80 mm between brain connections (two-way repeated measures ANOVA, group effect P-value of 2.6 × 10-12). Structure-function coupling analyses revealed that seizure-onset zones exhibit abnormally enhanced coupling (hypercoupling) of surrounding regions compared to presumably healthy tissue (two-way repeated measures ANOVA, interaction effect P-value of 9.76 × 10-21). Using these observations, our support vector classification models achieved a maximum held-out testing set accuracy of 92.0 ± 2.2% to classify early propagation and seizure-onset zones. These results suggest that seizure-onset zones are actively segregated and suppressed by a widespread brain network. Furthermore, this electrographically observed functional suppression is disproportionate to any observed structural connectivity alterations of the seizure-onset zones. These findings have implications for the identification of seizure-onset zones using only brief electrographic recordings to reduce patient morbidity and augment the presurgical evaluation of drug-resistant epilepsy. Further testing of the interictal suppression hypothesis can provide insight into potential new resective, ablative and neuromodulation approaches to improve surgical success rates in those suffering from drug-resistant focal epilepsy.

Exploratory Multisite MR Spectroscopic Imaging Shows White Matter Neuroaxonal Loss Associated with Complications of Type 1 Diabetes in Children

BACKGROUND AND PURPOSE

Type 1 diabetes affects over 200,000 children in the United States and is associated with an increased risk of cognitive dysfunction. Prior single-site, single-voxel MRS case reports and studies have identified associations between reduced NAA/Cr, a marker of neuroaxonal loss, and type 1 diabetes. However, NAA/Cr differences among children with various disease complications or across different brain tissues remain unclear. To better understand this phenomenon and the role of MRS in characterizing it, we conducted a multisite pilot study.

MATERIALS AND METHODS

In 25 children, 6-14 years of age, with type 1 diabetes across 3 sites, we acquired T1WI and axial 2D MRSI along with phantom studies to calibrate scanner effects. We quantified tissue-weighted NAA/Cr in WM and deep GM and modeled them against study covariates.

RESULTS

We found that MRSI differentiated WM and deep GM by NAA/Cr on the individual level. On the population level, we found significant negative associations of WM NAA/Cr with chronic hyperglycemia quantified by hemoglobin A1c (P < .005) and a history of diabetic ketoacidosis at disease onset (P < .05). We found a statistical interaction (P < .05) between A1c and ketoacidosis, suggesting that neuroaxonal loss from ketoacidosis may outweigh that from poor glucose control. These associations were not present in deep GM.

CONCLUSIONS

Our pilot study suggests that MRSI differentiates GM and WM by NAA/Cr in this population, disease complications may lead to neuroaxonal loss in WM in children, and deeper investigation is warranted to further untangle how diabetic ketoacidosis and chronic hyperglycemia affect brain health and cognition in type 1 diabetes.

Parasagittal dural space hypertrophy and amyloid-β deposition in Alzheimer's disease

One of the pathological hallmarks of Alzheimer's and related diseases is the increased accumulation of protein amyloid-β in the brain parenchyma. As such, recent studies have focused on characterizing protein and related clearance pathways involving perivascular flow of neurofluids, but human studies of these pathways are limited owing to limited methods for evaluating neurofluid circulation non-invasively in vivo. Here, we utilize non-invasive MRI methods to explore surrogate measures of CSF production, bulk flow and egress in the context of independent PET measures of amyloid-β accumulation in older adults. Participants (N = 23) were scanned at 3.0 T with 3D T2-weighted turbo spin echo, 2D perfusion-weighted pseudo-continuous arterial spin labelling and phase-contrast angiography to quantify parasagittal dural space volume, choroid plexus perfusion and net CSF flow through the aqueduct of Sylvius, respectively. All participants also underwent dynamic PET imaging with amyloid-β tracer 11C-Pittsburgh Compound B to quantify global cerebral amyloid-β accumulation. Spearman's correlation analyses revealed a significant relationship between global amyloid-β accumulation and parasagittal dural space volume (rho = 0.529, P = 0.010), specifically in the frontal (rho = 0.527, P = 0.010) and parietal (rho = 0.616, P = 0.002) subsegments. No relationships were observed between amyloid-β and choroid plexus perfusion nor net CSF flow. Findings suggest that parasagittal dural space hypertrophy, and its possible role in CSF-mediated clearance, may be closely related to global amyloid-β accumulation. These findings are discussed in the context of our growing understanding of the physiological mechanisms of amyloid-β aggregation and clearance via neurofluids.

Cognitive phenotypes in late-life depression

OBJECTIVE

To identify cognitive phenotypes in late-life depression (LLD) and describe relationships with sociodemographic and clinical characteristics.

DESIGN

Observational cohort study.

SETTING

Baseline data from participants recruited via clinical referrals and community advertisements who enrolled in two separate studies.

PARTICIPANTS

Non-demented adults with LLD (n = 120; mean age = 66.73 ± 5.35 years) and non-depressed elders (n = 56; mean age = 67.95 ± 6.34 years).

MEASUREMENTS

All completed a neuropsychological battery, and individual cognitive test scores were standardized across the entire sample without correcting for demographics. Five empirically derived cognitive domain composites were created, and cluster analytic approaches (hierarchical, k-means) were independently conducted to classify cognitive patterns in the depressed cohort only. Baseline sociodemographic and clinical characteristics were then compared across groups.

RESULTS

A three-cluster solution best reflected the data, including "High Normal" (n = 47), "Reduced Normal" (n = 35), and "Low Executive Function" (n = 37) groups. The "High Normal" group was younger, more educated, predominantly Caucasian, and had fewer vascular risk factors and higher Mini-Mental Status Examination compared to "Low Executive Function" group. No differences were observed on other sociodemographic or clinical characteristics. Exploration of the "High Normal" group found two subgroups that only differed in attention/working memory performance and length of the current depressive episode.

CONCLUSIONS

Three cognitive phenotypes in LLD were identified that slightly differed in sociodemographic and disease-specific variables, but not in the quality of specific symptoms reported. Future work on these cognitive phenotypes will examine relationships to treatment response, vulnerability to cognitive decline, and neuroimaging markers to help disentangle the heterogeneity seen in this patient population.

Is the Number of National Database Research Studies in Musculoskeletal Sarcoma Increasing, and Are These Studies Reliable?

BACKGROUND

Large national databases have become a common source of information on patterns of cancer care in the United States, particularly for low-incidence diseases such as sarcoma. Although aggregating information from many hospitals can achieve statistical power, this may come at a cost when complex variables must be abstracted from the medical record. There is a current lack of understanding of the frequency of use of the Surveillance, Epidemiology, and End Results (SEER) database and the National Cancer Database (NCDB) over the last two decades in musculoskeletal sarcoma research and whether their use tends to produce papers with conflicting findings.

QUESTIONS/PURPOSES

(1) Is the number of published studies using the SEER and NCDB databases in musculoskeletal sarcoma research increasing over time? (2) What are the author, journal, and content characteristics of these studies? (3) Do studies using the SEER and the NCDB databases for similar diagnoses and study questions report concordant or discordant key findings? (4) Are the administrative data reported by our institution to the SEER and the NCDB databases concordant with the data in our longitudinally maintained, physician-run orthopaedic oncology dataset?

METHODS

To answer our first three questions, PubMed was searched from 2001 through 2020 for all studies using the SEER or the NCDB databases to evaluate sarcoma. Studies were excluded from the review if they did not use these databases or studied anatomic locations other than the extremities, nonretroperitoneal pelvis, trunk, chest wall, or spine. To answer our first question, the number of SEER and NCDB studies were counted by year. The publication rate over the 20-year span was assessed with simple linear regression modeling. The difference in the mean number of studies between 5-year intervals (2001-2005, 2006-2010, 2011-2015, 2016-2020) was also assessed with Student t-tests. To answer our second question, we recorded and summarized descriptive data regarding author, journal, and content for these studies. To answer our third question, we grouped all studies by diagnosis, and then identified studies that shared the same diagnosis and a similar major study question with at least one other study. We then categorized study questions (and their associated studies) as having concordant findings, discordant findings, or mixed findings. Proportions of studies with concordant, discordant, or mixed findings were compared. To answer our fourth question, a coding audit was performed assessing the concordance of nationally reported administrative data from our institution with data from our longitudinally maintained, physician-run orthopaedic oncology dataset in a series of patients during the past 3 years. Our orthopaedic oncology dataset is maintained on a weekly basis by the senior author who manually records data directly from the medical record and sarcoma tumor board consensus notes; this dataset served as the gold standard for data comparison. We compared date of birth, surgery date, margin status, tumor size, clinical stage, and adjuvant treatment.

RESULTS

The number of musculoskeletal sarcoma studies using the SEER and the NCDB databases has steadily increased over time in a linear regression model (β = 2.51; p < 0.001). The mean number of studies per year more than tripled during 2016-2020 compared with 2011-2015 (39 versus 13 studies; mean difference 26 ± 11; p = 0.03). Of the 299 studies in total, 56% (168 of 299) have been published since 2018. Nineteen institutions published more than five studies, and the most studies from one institution was 13. Orthopaedic surgeons authored 35% (104 of 299) of studies, and medical oncology journals published 44% (130 of 299). Of the 94 studies (31% of total [94 of 299]) that shared a major study question with at least one other study, 35% (33 of 94) reported discordant key findings, 29% (27 of 94) reported mixed key findings, and 44% (41 of 94) reported concordant key findings. Both concordant and discordant groups included papers on prognostic factors, demographic factors, and treatment strategies. When we compared nationally reported administrative data from our institution with our orthopaedic oncology dataset, we found clinically important discrepancies in adjuvant treatment (19% [15 of 77]), tumor size (21% [16 of 77]), surgery date (23% [18 of 77]), surgical margins (38% [29 of 77]), and clinical stage (77% [59 of 77]).

CONCLUSION

Appropriate use of databases in musculoskeletal cancer research is essential to promote clear interpretation of findings, as almost two-thirds of studies we evaluated that asked similar study questions produced discordant or mixed key findings. Readers should be mindful of the differences in what each database seeks to convey because asking the same questions of different databases may result in different answers depending on what information each database captures. Likewise, differences in how studies determine which patients to include or exclude, how they handle missing data, and what they choose to emphasize may result in different messages getting drawn from large-database studies. Still, given the rarity and heterogeneity of sarcomas, these databases remain particularly useful in musculoskeletal cancer research for nationwide incidence estimations, risk factor/prognostic factor assessment, patient demographic and hospital-level variable assessment, patterns of care over time, and hypothesis generation for future prospective studies.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Human pancreatic capillaries and nerve fibers persist in type 1 diabetes despite beta cell loss

The autonomic nervous system regulates pancreatic function. Islet capillaries are essential for the extension of axonal projections into islets, and both of these structures are important for appropriate islet hormone secretion. Because beta cells provide important paracrine cues for islet glucagon secretion and neurovascular development, we postulated that beta cell loss in type 1 diabetes (T1D) would lead to a decline in intraislet capillaries and reduction of islet innervation, possibly contributing to abnormal glucagon secretion. To define morphological characteristics of capillaries and nerve fibers in islets and acinar tissue compartments, we analyzed neurovascular assembly across the largest cohort of T1D and normal individuals studied thus far. Because innervation has been studied extensively in rodent models of T1D, we also compared the neurovascular architecture between mouse and human pancreas and assembled transcriptomic profiles of molecules guiding islet angiogenesis and neuronal development. We found striking interspecies differences in islet neurovascular assembly but relatively modest differences at transcriptome level, suggesting that posttranscriptional regulation may be involved in this process. To determine whether islet neurovascular arrangement is altered after beta cell loss in T1D, we compared pancreatic tissues from non-diabetic, recent-onset T1D (<10-yr duration), and longstanding T1D (>10-yr duration) donors. Recent-onset T1D showed greater islet and acinar capillary density compared to non-diabetic and longstanding T1D donors. Both recent-onset and longstanding T1D had greater islet nerve fiber density compared to non-diabetic donors. We did not detect changes in sympathetic axons in either T1D cohort. Additionally, nerve fibers overlapped with extracellular matrix (ECM), supporting its role in the formation and function of axonal processes. These results indicate that pancreatic capillaries and nerve fibers persist in T1D despite beta cell loss, suggesting that alpha cell secretory changes may be decoupled from neurovascular components.NEW & NOTEWORTHY Defining the neurovascular architecture in the pancreas of individuals with type 1 diabetes (T1D) is crucial to understanding the mechanisms of dysregulated glucagon secretion. In the largest T1D cohort of biobanked tissues analyzed to date, we found that pancreatic capillaries and nerve fibers persist in human T1D despite beta cell loss, suggesting that alpha cell secretory changes may be decoupled from neurovascular components. Because innervation has been studied extensively in rodent T1D models, our studies also provide the first rigorous direct comparisons of neurovascular assembly in mouse and human, indicating dramatic interspecies differences.

Harmonization of repetition time and scanner effects on estimates of brain hemodynamic response function

Multisite contributions are essential to improve the reliability and statistical power of imaging studies but introduce a complexity because of different acquisition protocols and scanners. The hemodynamic response function (HRF) is the transform that relates neural activity to the measured blood oxygenation level-dependent (BOLD) signal in MRI and contains information about the latency, amplitude, and duration of neuronal activations. Acquisition variabilities, without adding harmonization techniques, can severely limit our ability to characterize spatial effects. To address this problem, we propose to study and remove variabilities of the sampling rate and scanners on estimates of the HRF. We computed the HRF using a blind deconvolution method in 547 subjects from the Alzheimer's Disease Neuroimaging Initiative (ADNI) across 62 sites and 18 scanners. The approach consists of studying the changes of the response according to repetition times (TR) and scanner models. We applied ComBAT, a statistical multi-site harmonization technique, to evaluate and reduce the scanner and repetition time effects and used the Wilcoxon rank sum test to assess the performance of the harmonization. Results show high scanner and repetition time variabilities (|d| ≥ 0.38, p = 4.5 × 10-5) across features, indicating that using harmonization is crucial in multi-site studies. ComBAT successfully removes the sampling effects and reduces the variance between scanners for 7 out of 10 of the HRF features (|d| ≤ 0.05, p = 0.0052). Scanners effects have been characterized on multi-site datasets, but the repetition time impact has been less studied. We showed that the use of different values of repetition time leads to changes in HRF behavior. Regression modeling changes in the HRF on the harmonized data are not significant (p = 0.0401) which does not allow to conclude how HRF changes with aging.

Treatment outcomes of multidrug-resistant TB with selective use of new drugs

SETTING: This was a nationwide cohort study.OBJECTIVE: To assess the treatment outcomes in patients with multidrug-resistant TB (MDR-TB) who underwent treatment guided by a national TB expert review committee in South Korea.DESIGN: We enrolled all patients with MDR-TB submitted for approval for the use of new TB drugs, including bedaquiline and delamanid, from 2016 to 2019. Patients were classified into two groups: those on new TB drugs and those not on new TB drugs. We compared the final treatment outcomes between the groups and analysed the prognostic factors.RESULTS: Of a total of 785 patients, respectively 754 (96.1%) and 31 (3.9%) were classified into the "new TB drugs" group and "no new TB drugs" group. The new TB drugs group had a higher acid-fast bacilli smear positivity rate and higher resistance rate to second-line injectable drugs or fluoroquinolones. Of all the patients, 97.8% achieved culture conversion (97.7% vs. 100%), and 80.4% achieved treatment success (80.2% vs. 86.7%); there was no difference between the two groups.CONCLUSIONS: New drugs are currently recommended for use in all MDR-TB treatment regimens, and the use of new drugs, as determined by an expert committee, in mainly quinolone-susceptible MDR-TB, did not compromise the treatment success rate.

Short superficial white matter and aging: a longitudinal multi-site study of 1293 subjects and 2711 sessions

It is estimated that short association fibers running immediately beneath the cortex may make up as much as 60% of the total white matter volume. However, these have been understudied relative to the long-range association, projection, and commissural fibers of the brain. This is largely because of limitations of diffusion MRI fiber tractography, which is the primary methodology used to non-invasively study the white matter connections. Inspired by recent anatomical considerations and methodological improvements in superficial white matter (SWM) tractography, we aim to characterize changes in these fiber systems in cognitively normal aging, which provide insight into the biological foundation of age-related cognitive changes, and a better understanding of how age-related pathology differs from healthy aging. To do this, we used three large, longitudinal and cross-sectional datasets (N = 1293 subjects, 2711 sessions) to quantify microstructural features and length/volume features of several SWM systems. We find that axial, radial, and mean diffusivities show positive associations with age, while fractional anisotropy has negative associations with age in SWM throughout the entire brain. These associations were most pronounced in the frontal, temporal, and temporoparietal regions. Moreover, measures of SWM volume and length decrease with age in a heterogenous manner across the brain, with different rates of change in inter-gyri and intra-gyri SWM, and at slower rates than well-studied long-range white matter pathways. These features, and their variations with age, provide the background for characterizing normal aging, and, in combination with larger association pathways and gray matter microstructural features, may provide insight into fundamental mechanisms associated with aging and cognition.

Altered EEG, disrupted hippocampal long-term potentiation and neurobehavioral deficits implicate a delirium-like state in a mouse model of sepsis

Sepsis and systemic inflammation are often accompanied by severe encephalopathy, sleep disruption and delirium that strongly correlate with poor clinical outcomes including long-term cognitive deficits. The cardinal manifestations of delirium are fluctuating altered mental status and inattention, identified in critically ill patients by interactive bedside assessment. The lack of analogous assessments in mouse models or clear biomarkers is a challenge to preclinical studies of delirium. In this study, we utilized concurrent measures of telemetric EEG recordings and neurobehavioral tasks in mice to characterize inattention and persistent cognitive deficits following polymicrobial sepsis. During the 24-hour critical illness period for the mice, slow-wave EEG dominance, sleep disruption, and hypersensitivity to auditory stimuli in neurobehavioral tasks resembled clinical observations in delirious patients in which alterations in similar outcome measurements, although measured differently in mice and humans, are reported. Mice were tested for nest building ability 7 days after sepsis induction, when sickness behaviors and spontaneous activity had returned to baseline. Animals that showed persistent deficits determined by poor nest building at 7 days also exhibited molecular changes in hippocampal long-term potentiation compared to mice that returned to baseline cognitive performance. Together, these behavioral and electrophysiological biomarkers offer a robust mouse model with which to further probe molecular pathways underlying brain and behavioral changes during and after acute illness such as sepsis.

Towards differentiation of brain tumor from radiation necrosis using multi-parametric MRI: Preliminary results at 4.7 T using rodent models

BACKGROUND

It remains a clinical challenge to differentiate brain tumors from radiation-induced necrosis in the brain. Despite significant improvements, no single MRI method has been validated adequately in the clinical setting.

METHODS

Multi-parametric MRI (mpMRI) was performed to differentiate 9L gliosarcoma from radiation necrosis in animal models. Five types of MRI methods probed complementary information on different scales i.e., T2 (relaxation), CEST based APT (probing mobile proteins/peptides) and rNOE (mobile macromolecules), qMT (macromolecules), diffusion based ADC (cell density) and SSIFT iAUC (cell size), and perfusion based DSC (blood volume and flow).

RESULTS

For single MRI parameters, iAUC and ADC provide the best discrimination of radiation necrosis and brain tumor. For mpMRI, a combination of iAUC, ADC, and APT shows the best classification performance based on a two-step analysis with the Lasso and Ridge regressions.

CONCLUSION

A general mpMRI approach is introduced to choosing candidate multiple MRI methods, identifying the most effective parameters from all the mpMRI parameters, and finding the appropriate combination of chosen parameters to maximize the classification performance to differentiate tumors from radiation necrosis.

[Clinical features and prognosis of cutaneous melanoma]

Objective: To analyze the clinical features and prognosis of patients with cutaneous melanoma. Methods: The clinical data and follow-up data of 125 patients with cutaneous malignant melanoma (CMM) treated in the Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology between February 2008 and August 2019 were collected. Kaplan-Meier method and Log rank test were used for survival analysis, and Cox proportional risk regression model was used for impact factor analysis. Results: Among the 125 patients, 12 were stage Ⅰ, 62 were stage Ⅱ, 30 were stage Ⅲ, and 21 were stage Ⅳ; 76 were acral and 49 were non-acral. The median survival time was 44 months, and the 1-, 2-, and 5-year survival rates were 85.4%, 63.2% and 38.7%, respectively. Kaplan-Meier univariate survival analysis showed that Karnofsky performance status score, tumor stage, primary site, vascular infiltration, Ki-67, BRAF, lactate dehydrogenase (LDH), and surgical treatment were related to the prognosis of patients (P<0.05). The median overall survival (OS) time of patients receiving interferon treatment was 53 months, which was better than 40 months of patients not receiving interferon treatment, but the difference was not statistically significant (P=0.448). Among stage Ⅲ patients, the median OS time of patients receiving interferon therapy was 40 months, which was better than 17 months of patients not receiving interferon therapy (P=0.012). Among stage Ⅱ patients, the 1-, 2-, and 5-year survival rates of acral patients were 97.1%, 84.7%, and 65.8%, and the 1-, 2-, and 5-year survival rates of non-acral patients were 93.3%, 70.0% and 17.0%. The prognosis of patients with stage Ⅱ acral type was better than that of non-acral type (P=0.043). The median survival time of stage Ⅲ patients with acral type was 32 months, better than 17 months of non-acral type, but the difference was not statistical significance (P=0.164). The median survival time of acral type and non-acral type was 8 months and 11 months respectively (P=0.458). Cox multivariate analysis showed that tumor stage and preoperative LDH level were independent prognostic risk factors for cutaneous melanoma. Conclusions: Interferon treatment can improve the prognosis of patients with stage Ⅲ, and stage Ⅱ acral type patients have better prognosis than that of non-acral type patients. Tumor stage and preoperative LDH level were independent prognostic risk factors for cutaneous melanoma.

Amphetamine-induced dopamine release and impulsivity in Parkinson's disease

Impulsive-compulsive behaviours manifest in a substantial proportion of subjects with Parkinson's disease. Reduced ventral striatum dopamine receptor availability, and increased dopamine release is noted in patients with these symptoms. Prior studies of impulsivity suggest that midbrain D2 autoreceptors regulate striatal dopamine release in a feedback inhibitory manner, and in healthy populations, greater impulsivity is linked to poor proficiency of this inhibition. This has not been assessed in a Parkinson's disease population. Here, we applied 18F-fallypride PET studies to assess striatal and extrastriatal D2-like receptor uptake in a placebo-controlled oral dextroamphetamine sequence. We hypothesized that Parkinson's disease patients with impulsive-compulsive behaviours would have greater ventral striatal dopaminergic response to dextroamphetamine, and that an inability to attenuate ventral striatal dopamine release via midbrain D2 autoreceptors would underlie this response. Twenty patients with Parkinson's disease (mean age = 64.1 ± 5.8 years) both with (n = 10) and without (n = 10) impulsive-compulsive behaviours, participated in a single-blind dextroamphetamine challenge (oral; 0.43 mg/kg) in an OFF dopamine state. All completed PET imaging with 18F-fallypride, a high-affinity D2-like receptor ligand, in the placebo and dextroamphetamine state. Both voxelwise and region of interest analyses revealed dextroamphetamine-induced endogenous dopamine release localized to the ventral striatum, and the caudal-medial orbitofrontal cortex. The endogenous dopamine release observed in the ventral striatum correlated positively with patient-reported participation in reward-based behaviours, as quantified by the self-reported Questionnaire for Impulsivity in Parkinson's disease Rating Scale. In participants without impulsive-compulsive behaviours, baseline midbrain D2 receptor availability negatively correlated with ventral striatal dopamine release; however, this relationship was absent in those with impulsive-compulsive behaviours. These findings emphasize that reward-based behaviours in Parkinson's disease are regulated by ventral striatal dopamine release, and suggest that loss of inhibitory feedback from midbrain autoreceptors may underlie the manifestation of impulsive-compulsive behaviours.

Editorial for "Pre-Surgical Magnetic Resonance Imaging Indicators of Revascularization Response in Adults With Moyamoya Vasculopathy"

Background:

Moyamoya is a progressive intracranial vasculopathy, primarily affecting distal segments of the internal carotid and middle cerebral arteries. Treatment may comprise angiogenesis-inducing surgical revascularization, however lack of randomized trials often results in subjective treatment decisions.

Hypothesis:

Compensatory pre-surgical posterior vertebrobasilar (VBA) flow-territory reactivity, including greater cerebrovascular reactivity and reduced vascular delay time, portends greater neoangiogenic response verified on digital subtraction angiography (DSA) at one-year follow-up.

Study Type:

Prospective intervention cohort.

Subjects:

31 patients with moyamoya (26 female; age=45±13 years; 41 revascularized hemispheres).

Methods:

Anatomical MRI, hypercapnic cerebrovascular reactivity MRI, and DSA acquired pre-surgically in adult moyamoya participants scheduled for clinically-indicated surgical revascularization. One year post-surgery, DSA was repeated to evaluate collateralization.

Field Strength:

3 Tesla.

Sequence:

Hypercapnic T 2*-weighted gradient-echo blood-oxygenation-level-dependent, T 2-weighted turbo-spin-echo fluid-attenuated-inversion-recovery, T 1-weighted magnetization-prepared-rapid-gradient-echo, and T 2-weighted diffusion-weighted imaging.

Assessment:

Pre-surgical maximum cerebrovascular reactivity and response times were evaluated in VBA flow-territories. Revascularization success was determined using an ordinal scoring system of neoangiogenic collateralization from post-surgical DSA by two cerebrovascular neurosurgeons (RVC; experience=8 years; MRF, experience=9 years) and one neuroradiologist (LTD, experience=8 years). Stroke risk factors (age, sex, race, vasculopathy, and diabetes) were recorded.

Statistical Tests:

Fisher’s exact and Wilcoxon rank-sum tests were applied to compare pre-surgical variables between cohorts with angiographically-confirmed good (>1/3 MCA territory revascularized) vs. poor (<1/3 MCA territory revascularized) outcomes. Significance: two-sided p<0.05. Normalized odds ratios (OR) were calculated.

Results:

Criteria for good collateralization were met in 25 of 41 revascularized hemispheres. Pre-surgical normalized VBA flow-territory cerebrovascular reactivity was significantly higher in those with good (1.12±0.13 unitless) vs. poor (1.04±0.05 unitless) outcomes. Younger (OR=−0.60±0.67) and White (OR=−1.81±1.40) participants had highest revascularization success (good outcomes: age=42±14 years, race=84% White; poor outcomes: age=49±11 years, race=44% White).

Data Conclusion:

Pre-surgical MRI-measures of VBA flow-territory cerebrovascular reactivity are highest in moyamoya participants with better angiographic responses to surgical revascularization.

Presurgical Magnetic Resonance Imaging Indicators of Revascularization Response in Adults With Moyamoya Vasculopathy

BACKGROUND

Moyamoya is a progressive intracranial vasculopathy, primarily affecting distal segments of the internal carotid and middle cerebral arteries. Treatment may comprise angiogenesis-inducing surgical revascularization; however, lack of randomized trials often results in subjective treatment decisions.

HYPOTHESIS

Compensatory presurgical posterior vertebrobasilar artery (VBA) flow-territory reactivity, including greater cerebrovascular reactivity (CVR) and reduced vascular delay time, portends greater neoangiogenic response verified on digital subtraction angiography (DSA) at 1-year follow-up.

STUDY TYPE

Prospective intervention cohort.

SUBJECTS

Thirty-one patients with moyamoya (26 females; age = 45 ± 13 years; 41 revascularized hemispheres).

METHODS

Anatomical MRI, hypercapnic CVR MRI, and DSA acquired presurgically in adult moyamoya participants scheduled for clinically indicated surgical revascularization. One-year postsurgery, DSA was repeated to evaluate collateralization.

FIELD STRENGTH

3 T.

SEQUENCE

Hypercapnic T 2 * -weighted gradient-echo blood-oxygenation-level-dependent, T2 -weighted turbo-spin-echo fluid-attenuated-inversion-recovery, T1 -weighted magnetization-prepared-rapid-gradient-echo, and T2 -weighted diffusion-weighted-imaging.

ASSESSMENT

Presurgical maximum CVR and response times were evaluated in VBA flow-territories. Revascularization success was determined using an ordinal scoring system of neoangiogenic collateralization from postsurgical DSA by two cerebrovascular neurosurgeons (R.V.C. with 8 years of experience; M.R.F. with 9 years of experience) and one neuroradiologist (L.T.D. with 8 years of experience). Stroke risk factors (age, sex, race, vasculopathy, and diabetes) were recorded.

STATISTICAL TESTS

Fisher's exact and Wilcoxon rank-sum tests were applied to compare presurgical variables between cohorts with angiographically confirmed good (>1/3 middle cerebral artery [MCA] territory revascularized) vs. poor (<1/3 MCA territory revascularized) outcomes.

SIGNIFICANCE

two-sided P < 0.05. Normalized odds ratios (ORs) were calculated.

RESULTS

Criteria for good collateralization were met in 25 of the 41 revascularized hemispheres. Presurgical normalized VBA flow-territory CVR was significantly higher in those with good (1.12 ± 0.13 unitless) vs. poor (1.04 ± 0.05 unitless) outcomes. Younger (OR = -0.60 ± 0.67) and White (OR = -1.81 ± 1.40) participants had highest revascularization success (good outcomes: age = 42 ± 14 years, race = 84% White; poor outcomes: age = 49 ± 11 years, race = 44% White).

DATA CONCLUSION

Presurgical MRI-measures of VBA flow-territory CVR are highest in moyamoya participants with better angiographic responses to surgical revascularization.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 4.

Effectiveness of an integrative medicine approach to improve cognitive dysfunction and dementia: An observational study

Despite the urgent need to control dementia, an effective treatment has yet to be developed. Along with the Korean government's policy of cooperation between conventional medicine (CM) and Korean medicine (KM), integrative medical services for dementia patients are being provided. This study aimed to compare the integrative medical clinic (IMC) for dementia used by Dongguk University Hospitals (DUH) with other service models and to review the characteristics and treatment outcomes of patients who had visited DUH over the past 5 years. Patients' electronic medical records from May 2015 to June 2020 were searched and their data were analyzed to evaluate the IMC's service model. Patient demographic and clinical characteristics, diagnostic tests, and treatment patterns for CM and KM were collected. The proportion of patients who did not show worsening cognitive function was described in detail. A strength of the DUH integrative medicine clinic is its ability to manage both KM and CM patients in the same space at the same time. Among the 82 patients who visited the clinic during our study period, 56 remained for data analysis after we excluded patients who met the exclusion criteria; nineteen patients had diagnoses of mild cognitive impairment. Among collaboration patterns, the first visit to the IMC had the highest proportion (55.4%). Among diagnosed tests in CM, laboratory tests and neuropsychological tests were used the most. In KM, a heart rate variability test was frequently used. The most common CM treatment prescribed was anticonvulsants, with 22 patients (39.2%) receiving donepezil, whereas the most frequent KM treatments were acupuncture (82.1%) and herbal medicine (78.6%). Twelve patients were followed up with the Mini-Mental State Examination, and 8 demonstrated either no worsening or improved cognition (baseline Mini-Mental State Examination range: 21-26). All 8 patients had mild cognitive impairment including 6 with amnestic, multidomain impairment. This study searched for a way to improve cognitive dysfunction and dementia using an integrative approach, and it shows promising results for mild cognitive impairment. However, more precisely designed follow-up studies are needed to address the present work's limitations of a retrospective study design and a small sample size.

[Activation of cannabinoid receptor 2 alleviates acute lung injury in rats with lipopolysaccharide-induced sepsis]

OBJECTIVE

To investigate the protective effect of cannabinoid receptor 2 (CB2) activation against acute lung injury in rats with lipopolysaccharide (LPS)-induced sepsis and explore the underlying mechanism.

METHODS

Forty-eight SD rats were randomly assigned into control group, model group, CB2 agonist group and P38 MAPK inhibitor group (n=12). In the latter 3 groups, the rats received intraperitoneal injection of LPS to induce sepsis, and the control rats were given saline injection. In CB2 agonist group, JWH133 (3 mg/kg) was injected intraperitoneally 30 min before LPS injection; in P38 MAPK inhibitor group, the rats received intraperitoneal injection of SB203580 (5 mg/kg) 30 min prior to JWH133 injection. The changes in lung histopathology, water content, fluid clearance rate, inflammatory factors, pulmonary expressions of CB2 and tight junctionrelated genes, and phosphorylation of P38 MAPK in the lung tissues were examined.

RESULTS

The rat models of sepsis showed severe damage of alveolar structures with significantly decreased fluid clearance rate, lowered pulmonary expressions of CB2, occludin and ZO-1 mRNA and proteins, increased water content in the lung tissue, and increased phosphorylation level of P38 MAPK and TNF-α and IL-1β levels in lung lavage fluid (all P < 0.05). Treatment with JWH133 improved alveolar pathology in the septic rats, but there was still inflammatory infiltration; lung tissue water content, phosphorylation of P38 MAPK, and TNF-α and IL-1β levels in lung lavage fluid were all significantly decreased, and the fluid clearance rate, pulmonary expressions of CB2, occludin and ZO-1 were significantly increased (all P < 0.05). Additional treatment with SB203580 resulted in further improvements of alveolar pathologies, lowered phosphorylation levels of P38 MAPK in the lung tissue and TNF-α and IL-1β levels in lung lavage fluid, and increased the protein expressions of occludin and ZO-1 (P < 0.05) without causing significant changes in mRNA and protein expression of CB2 (P > 0.05).

CONCLUSION

In rats with LPS-induced sepsis, activation of CB2 can inhibit the p38 MAPK signaling pathway, reduce the release of inflammatory factors in the lung tissues, promote tight junction protein expressions, and thus offer protection against acute lung injury.

P02.01.B The telomere maintenance mechanism spectrum and its dynamics in gliomas

The activation of the telomere maintenance mechanism (TMM) is one of the critical drivers of cancer cell immortality. In gliomas, TERT expression and TERT promoter mutation are considered to reliably indicate telomerase activation, while ATRX mutation indicates alternative lengthening of telomeres (ALT). However, these relationships have not been extensively validated in tumor tissues. Here, we show through the direct measurement of telomerase activity and ALT in a large set of glioma samples that the TMM in glioma cannot be defined in the dichotomy of telomerase activity and ALT, regardless of TERT expression, TERT promoter mutation and ATRX mutation. Moreover, we observed that a considerable proportion of gliomas lack both telomerase activity and ALT (Neither group). And this Neither group exhibited evidence of slow growth potential. From a set of longitudinal samples from a separate cohort of glioma patients, we discovered that the TMM is not fixed but changes with glioma progression. Collectively, these results suggest that the TMM is a dynamic entity and that reflects the plasticity of the oncogenic biological status of tumor cells and that the TMM should be defined by the direct measurement of telomerase enzyme activity and evidence of ALT.

Holter electrocardiogram research trends and hotspots: bibliometrics and visual analysis

OBJECTIVE

With the help of metrology, we can identify research hotspots and development trends in dynamic electrocardiography, and thereby provide corresponding reference material to aid further theoretical research.

MATERIALS AND METHODS

All research data derived from the core collection of Web of Science, and all searches were completed on the same day (February 6, 2022). The obtained data were stored in plain text format and imported into CiteSpace for subsequent analysis. Citation analysis and visualization technology were used to draw a visual map of the research elements, using factors such as annual literature volume, country, journal, author, abstract, keywords, and citation.

RESULTS

After screening, 2,937 papers were obtained. Research on ambulatory electrocardiography is increasing worldwide every year. Using research hotspots, keyword-clustering time-zone maps, and high-frequency emerging words, the research in this field was roughly divided into two stages, with 2017 as the divider. The first stage primarily focuses on areas such as atrial fibrillation, stroke, autonomic nerve function, catheter ablation, and T-wave alternation. The second stage saw the focus shift to wearable devices, sudden cardiac death, obstructive sleep apnea, feature extraction, cryptogenic stroke, and similar topics.

CONCLUSIONS

With the development of various wearable technologies, the daily monitoring of healthy people engaged in sporting activities and the development of innovative analysis algorithms providing more accurate data may represent the hotspots and direction of future research.