Semiautomated Software to Improve Stability and Reduce Operator-Induced Variation in Vascular Ultrasound Speckle Tracking.

OBJECTIVES: Ultrasound is useful in predicting arteriovenous fistula (AVF) maturation, which is essential for hemodialysis in end-stage renal disease patients. We developed ultrasound software that measures circumferential vessel wall strain (distensibility) using conventional ultrasound Digital Imaging and Communications in Medicine (DICOM) data. We evaluated user-induced variability in measurement of arterial wall distensibility and upon finding considerable variation we developed and tested 2 methods for semiautomated measurement. METHODS: Ultrasound scanning of arteries of 10 subjects scheduled for AVF surgery were performed. The top and bottom of the vessel wall were tracked using the Kanade-Lucas-Tomasi (KLT) feature-tracking algorithm over the stack of images in the DICOM cine loops. The wall distensibility was calculated from the change of vessel diameter over time. Two semiautomated methods were used for comparison. RESULTS: The location of points selected by users for the cine loops varied significantly, with a maximum spread of up to 120 pixels (7.8 mm) for the top and up to 140 pixels (9.1 mm) for the bottom of the vessel wall. This variation in users' point selection contributed to the variation in distensibility measurements (ranging from 5.63 to 41.04%). Both semiautomated methods substantially reduced variation and were highly correlated with the median distensibility values obtained by the 10 users. CONCLUSIONS: Minimizing user-induced variation by standardizing point selection will increase reproducibility and reliability of distensibility measurements. Our recent semiautomated software may help expand use in clinical studies to better understand the role of vascular wall compliance in predicting the maturation of fistulas.

Childhood maltreatment and within-person associations between cortisol and affective experience.

Glucocorticoids exert profound effects on the brain and behavior, but cortisol concentrations are rarely linked to subjectively reported emotional states in humans. This study examined whether the link between cortisol and subjective anxiety varied by childhood maltreatment history. To do this, 97 individuals (60.8% female) participated in a standardized stress task in the laboratory (Trier Social Stress Test, TSST) while providing serial ratings of their feelings of anxiety as well as cortisol samples in blood. These measurements were collected nine times across the laboratory visit, from immediately before the TSST to 65 minutes after stress initiation. We estimated the within-person association between cortisol concentrations and momentary feelings of anxiety for individuals with and without exposure to childhood maltreatment, measured via self-report on the Childhood Trauma Questionnaire (CTQ). Individuals exposed to maltreatment during childhood reported the greatest feelings of anxiety when cortisol concentrations were lowest. This pattern was exaggerated among female participants, those with posttraumatic stress disorder (PTSD), and those exposed to emotional neglect relative to other forms of maltreatment. Early life adversity, such as parental maltreatment, may alter the role of cortisol in affective experiences. This observation may provide preliminary, translational evidence of a novel pathway through which stress may lead to and maintain internalizing symptoms in humans. More studies accounting for the moderating role of childhood maltreatment in biobehavioral pathways are needed.

Do diurnal salivary cortisol curves carry meaningful information about the regulatory biology of the HPA axis in healthy humans?

Salivary cortisol stress biomarkers have been extensively used in epidemiological work to document links between stress and ill health. There has been little effort to ground field friendly cortisol measures in the hypothalamic-pituitary-adrenal (HPA) axis regulatory biology that is likely relevant to delineating mechanistic pathways leading from stress exposure to detrimental health outcomes. Here, we utilized a healthy convenience sample (n = 140) to examine normal linkages between extensively collected salivary cortisol measures and available laboratory probes of HPA axis regulatory biology. Participants provided 9 saliva samples per day over 6 days within a month, while engaging in usual activities, and also participated in 5 regulatory tests (adrenocorticoptripin stimulation, dexamethasone/corticotropin-releasing-hormone stimulation, metyrapone, dexamethasone suppression, and Trier Social Stress Test). Logistical regression was used to test specific predictions linking cortisol curve components to regulatory variables and to explore widely for non-predicted associations. We found support for 2 of 3 original hypotheses, showing associations (1) between cortisol diurnal decline and feedback sensitivity as measured by dexamethasone suppression, and (2) between morning cortisol levels and adrenal sensitivity. We did not find links between central drive (metyrapone test) and end of day salivary levels. We confirmed an a priori expectation of limited linkage between regulatory biology and diurnal salivary cortisol measures, beyond those predicted. These data support an emerging focus on measures related to diurnal decline in epidemiological stress work. They raise questions about the biological meaning of other curve components, including morning cortisol levels, and perhaps CAR (Cortisol Awakening Response). If morning cortisol dynamics are linked to stress, more work on adrenal sensitivity in stress adaptation and stress-health links may be warranted.

DNA methylation GrimAge acceleration in US military veterans with PTSD.

Epigenetic alterations in DNA methylation might mediate gene expression effects of trauma underlying PTSD symptoms, or effects of PTSD on related health problems. PTSD is associated with all-cause morbidity and premature mortality, suggesting accelerated biological aging. We measured genome-wide DNA methylation (Illumina MethylationEPIC BeadChip) in whole blood in a treatment study for combat-related PTSD - "PROGrESS", a multisite RCT comparing sertraline plus enhanced medication management (SERT + EMM), prolonged exposure (PE) therapy plus placebo (PE + PLB), and the combination (SERT + PE). DNA methylation was measured in 140 US military veterans who served in Iraq and/or Afghanistan (112 current PTSD cases enrolled in a PTSD treatment study and 28 veterans without PTSD history controls), and also 59 non-trauma exposed controls at baseline posttreatment (24 weeks after baseline). Increased DNA methylation GrimAge acceleration (p = 8.8e-09) was observed in patients with PTSD compared to a pooled control group (trauma exposed and non-trauma exposed), suggesting a higher risk of premature mortality in those with PTSD. There was no difference in GrimAge acceleration between combat trauma and non-trauma exposed controls. No treatment-related changes in GrimAge acceleration were found in within-subject comparisons of PTSD patients pre- to post-treatment.

Development of open-source software for free-hand 3D vascular ultrasound: Dialysis fistula application.

BACKGROUND: The arteriovenous fistula (AVF) is the preferred vascular access for End Stage Renal Disease, having superior patency and lower infection risks than prosthetic graft and catheter access. When AVF dysfunction or delayed maturation does occur, the gold standard for diagnosis is the fistula angiogram (a.k.a. fistulogram). 3D ultrasound is available for obstetrical and other specialized uses, but it is cost prohibitive and has a field of view that is too small to cover the region of interest for the dialysis fistula application. We sought to develop a point of care 3D solution using freehand 2D ultrasound data acquisition. METHODS: We developed open-source software for 3D image reconstruction and projection of an angiogram-like image of the vascular access using a 2D freehand ultrasound scanner. We evaluated this software by comparing the ultrasound "sono-angiogram" images to fistulogram images in five subjects, using visual inspection and by applying the Percent of Exact Match (PEM) as a statistic test. RESULTS: The sono-angiograms showed identifiable characteristics that matched the fistulogram results in all five subjects. The PEM ranged between 42.8% and 77.0%, with Doppler and grayscale ultrasound data, showing complementary advantages and disadvantages when used for sono-angiogram image construction. Motion from freehand ultrasound acquisition was a significant source of mismatch. 3D image generation is a potential advantage with ultrasound data. CONCLUSIONS: While further work is needed to improve the accuracy with free hand scanning, fistulogram-like "sono-angiograms" can be generated using point of care 2D ultrasound. Methods such as these may be able to assist in point-of-care diagnosis in the future. The software is open-source, and importantly, the ultrasound data used are non-proprietary and available from any standard ultrasound machine. The simplicity and accessibility of this approach warrant further study.

Ultrasound Measurement of Vascular Distensibility Based on Edge Detection and Speckle Tracking Using Ultrasound DICOM Data.

This study presents an edge detection and speckle tracking (EDST) based algorithm to calculate distensibility as percentage of change of vessel diameter during cardiac cycles. Canny edge detector, Vandermonde matrix representation, Kanade Lucas Tomasi algorithm with pyramidal segmentation, and penalized least squares technique identifies the vessel lumen edge, track the vessel diameter, detrend the signal and find peaks and valleys when the vessel is fully distended or contracted. An upper extremity artery from 10 patients underwent an ultrasound examination as part of preoperative evaluation before arteriovenous fistula surgery. Three studies were performed to evaluate EDST with automatic peak and valley selection versus manual speckle selection of expert users using manual peak and valley selection. Results demonstrate the effectiveness of the proposed methodology, to obtain comparable results as those obtained by expert-users, and considerably reducing the variability associated with external factors such as excessive motion, fluctuations in stroke volume, beat-to-beat blood pressure changes, breathing cycles, and arm-transducer pressure.

Detecting High-Resolution Intramural Vascular Wall Strain Signals Using DICOM Data.

Maintaining dialysis vascular access is a source of considerable morbidity in patients with end-stage renal disease (ESRD). High-resolution radiofrequency (RF) ultrasound vascular strain imaging has been applied experimentally in the vascular access setting to assist in diagnosis and management. Unfortunately, high-resolution RF data are not routinely accessible to clinicians. In contrast, the standard DICOM formatted B-mode ultrasound data are widely accessible. However, B-mode, representing the envelope of the RF signal, is of much lower resolution. If strain imaging could use open-source B-mode data, these imaging techniques could be more broadly investigated. We conducted experiments to detect wall strain signals with submillimeter tracking resolutions ranging from 0.2 mm (3 pixels) to 0.65 mm (10 pixels) using DICOM B-mode data. We compared this submillimeter tracking to the overall vascular distensibility as the reference measurements to see if high-strain resolution strain could be detected using open-source B-Mode data. We measured the best-fit coefficient of determination between signals, expressed as the percentage of strain waveforms that exhibited a correlation with a p value of 0.05 or less. The lowest percentage was 86.7%, and most were 90% and higher. This indicates high-resolution strain signals can be detected within the vessel wall using B-mode DICOM data.

Sono-angiography for dialysis vascular access based on the freehand 2D ultrasound scanning.

INTRODUCTION: Dialysis vascular access, preferably an autogenous arteriovenous fistula, remains an end stage renal disease (ESRD) patient's lifeline providing a means of connecting the patient to the dialysis machine. Once an access is created, the current gold standard of care for maintenance of vascular access is angiography and angioplasty to treat stenosis. While point of care 2D ultrasound has been used to detect access problems, we sought to reproduce angiographic results comparable to the gold standard angiogram (fistulogram) using ultrasound data acquired from a conventional 2D ultrasound scanner. METHODS: A 2D ultrasound probe was used to acquire a series of cross sectional images of the vascular access including arteriovenous anastomosis of a subject with a radio-cephalic fistula. These 2D B-mode images were used for 3D vessel reconstruction by binary thresholding to categorize vascular versus non-vascular structures followed by standard image segmentation to select the structure representative of dialysis vascular access and morphologic filtering. Image processing was done using open source Python Software. RESULTS: The open source software was able to: (1) view the gold standard fistulogram images, (2) reconstruct 2D planar images of the fistula from ultrasound data as viewed from the top, analogous to computerized tomography images, and (3) construct a 2D representation of vascular access similar to the angiogram. CONCLUSION: We present a simple approach to obtain an angiogram-like representation of the vascular access from readily available, non-proprietary 2D ultrasound data in the point of care setting. While the sono-angiogram is not intended to replace angiography, it may be useful in providing 3D imaging at the point of care in the dialysis unit, outpatient clinic, or for pre-operative planning for interventional procedures. Future work will focus on improving the robustness and quality of the imaging data while preserving the straightforward freehand approach used for ultrasound data acquisition.

Ultrasound speckle tracking to detect vascular distensibility changes from angioplasty and branch ligation in a radio-cephalic fistula: Use of novel open source software.

We used novel open source software, based on an ultrasound speckle tracking algorithm, to examine the distensibility of the vessel wall of the inflow artery, anastomosis, and outflow vein before and after two procedures. An 83-year-old white man with a poorly maturing radio-cephalic fistula received an angioplasty at the anastomosis followed by branch ligation 28 days later. Duplex Doppler measurements corroborated the blood flow related changes anticipated from the interventions. The experimental distensibility results showed that it is technically feasible to measure subtle vessel wall motion changes with high resolution (sub-millimeter) using standard Digital Imaging and Communications in Medicine (DICOM) ultrasound data, which are readily available on conventional ultrasound scanners. While this methodology was originally developed using high resolution radiofrequency from ultrasound data, the goal of this study was to use DICOM data, which makes this technology accessible to a wide range of users.

Angioplasty Induced Changes in Dialysis Vascular Access Compliance.

Dialysis vascular access remains vitally important to maintain life and functional capacity with end stage renal disease. Angioplasty is an integral part of maintaining dialysis access function and patency. To understand the effect of angioplasty balloon dilation on vascular wall mechanics, we conducted a clinical study to evaluate the elastic modulus of the anastomosis in five subjects with anastomosis stenoses, before and after six angioplasty procedures, using B-mode ultrasound DICOM data. A novel and open source vascular ultrasound high-resolution speckle tracking software tool was used. The median lumen diameter increased from 3.4 to 5.5 mm after angioplasty. Meanwhile, the median elastic modulus of the 18 measurements at the anastomosis increased by 52.2%, from 2.24 × 103 to 3.41 × 103 mmHg. The results support our hypothesis that the structural changes induced in the vessel wall by balloon dilation lead to reduced vascular compliance and a higher elastic modulus of the vessel wall.

The roles of comorbidity and trauma exposure and its timing in shaping HPA axis patterns in depression.

BACKGROUND: Much work has documented hypothalamic pituitary adrenal (HPA) axis abnormalities in major depressive disorder (MDD), but inconsistencies leave this system's role in the illness unclear. Comparisons across studies are complicated by variation in co-morbidity (Posttraumatic Stress Disorder-PTSD, anxiety disorders), exposure to trauma, and timing of trauma (child vs. adult). Here, we examined the impact of these factors on HPA axis profiles in depression. METHODS: We recruited 5 groups of participants: MDD (n = 14), comorbid MDD + PTSD following adulthood trauma (MDD + PTSD-Adult; n = 12), comorbid MDD + PTSD following childhood trauma (MDD + PTSD-Child; n = 18), comorbid MDD + social anxiety disorder (MDD + SAD; n = 12), and non-depressed control participants who were sex and age matched to patients (combined total n = 36). HPA axis function was assessed using three challenges: stress reactivity via the Trier Social Stress Test (TSST), feedback sensitivity via a dexamethasone suppression test (DST), and central drive via a metyrapone challenge (MET). We compared hormonal responses between patient groups and their respective non-depressed controls. RESULTS: MDD + PTSD-Child showed low cortisol levels at baseline, and reduced adrenocorticotropic hormone (ACTH) levels at baseline and throughout the TSST. MDD-only, MDD + PTSD-Adult, and MDD + SAD did not differ from non-depressed controls in HPA axis responses to the TSST. Controlling for childhood trauma severity, the reduced baseline levels in MDD + PTSD-Child were no longer significant and significantly reduced baseline cortisol levels emerged for MDD + PTSD-Adult. No diagnostic group effects were detected with DST and MET. Childhood maltreatment subtypes were associated with unique HPA axis responses to TSST and MET. CONCLUSION: Comorbidity and trauma exposure, as well as their timing and type, contribute to inconsistencies in the depression literature and must be included in efforts to clarify the role of the HPA axis in MDD.

Cortisol awakening response in PTSD treatment: Predictor or mechanism of change.

PTSD is associated with abnormalities in hypothalamic-pituitary-adrenal (HPA) axis activity. This includes enhanced HPA axis negative feedback, attenuated cortisol awakening response, and attenuated cortisol response to personal trauma script. Whether HPA axis function predicts treatment response or treatment related symptom reduction in PTSD remains unclear. In addition, the relative effects of different treatment modalities (i.e., medication and psychotherapy) on HPA axis is unclear. To address this gap in knowledge, the PROGrESS study examined cortisol awakening response across treatment in Veterans with chronic PTSD randomized to receive Prolonged Exposure + Placebo (PE + PLB), Sertraline + PE (SERT + PE) or Sertraline + Enhanced Medication Management (SERT + EMM). Salivary cortisol awakening response (CAR) was assessed at baseline, mid-treatment (week 6 and 12), post-treatment (week 24) and follow-up (week 36 and 52). Among males at baseline, combat veterans with PTSD showed lower CAR Area Under the Curve Increase (AUCi; M = 3.15, SD = 9.57) than Combat controls (M = 7.63, SD = 9.07; p = .02), demonstrating combat veterans with PTSD have a less responsive system than combat controls. Higher PTSD severity was also related to lower CAR AUCi (r = -0.52, p = .03). When controlling for PTSD severity, higher baseline CAR AUCi was related to attenuated reduction in PTSD and lower likelihood of high treatment response over treatment (z = -2.06, p = .04).

Synergistic transcription activation by Maf and Sox and their subnuclear localization are disrupted by a mutation in Maf that causes cataract.

Crystallin genes are selectively expressed during lens development. Maf and Sox family proteins synergistically enhanced gammaF-crystallin promoter activity in a lens cell line. Mutational analysis of the gammaF-crystallin promoter identified a composite regulatory element containing nonconsensus Maf and Sox recognition sequences. Mutations in these recognition sequences or changes in their spacing eliminated synergistic transcription activation. The transcriptional synergy was also affected by changes in the orientation of the Maf recognition sequence that had no detectable effect on binding affinity. The interaction between Maf and Sox proteins was visualized in living cells by bimolecular fluorescence complementation analysis. The N-terminal region of Maf mediated the interaction with Sox proteins in cells. Synergistic transcription activation required the N-terminal region of Maf as well as the ancillary DNA binding domain and the unique portion of the basic region that mediate specific recognition of the gammaF-crystallin promoter element. A mutation in the ancillary DNA binding domain of Maf (R288P) that has been shown to cause cataract eliminated the transcriptional activity of Maf but had no detectable effect on DNA binding in vitro. Whereas wild-type Maf was uniformly distributed in the nucleoplasm, R288P Maf was enriched in nuclear foci. Cajal bodies and gemini of coiled bodies were closely associated with the foci occupied by R288P Maf. Wild-type Maf formed complexes with Sox proteins in the nucleoplasm, whereas R288P Maf recruited Sox proteins as well as other interaction partners to the nuclear foci. The mislocalization of normal cellular proteins to these foci provides a potential explanation for the dominant disease phenotype of the R288P mutation in Maf.

DHEA enhances emotion regulation neurocircuits and modulates memory for emotional stimuli.

Dehydroepiandrosterone (DHEA) is a neurosteroid with anxiolytic, antidepressant, and antiglucocorticoid properties. It is endogenously released in response to stress, and may reduce negative affect when administered exogenously. Although there have been multiple reports of DHEA's antidepressant and anxiolytic effects, no research to date has examined the neural pathways involved. In particular, brain imaging has not been used to link neurosteroid effects to emotion neurocircuitry. To investigate the brain basis of DHEA's impact on emotion modulation, patients were administered 400 mg of DHEA (N=14) or placebo (N=15) and underwent 3T fMRI while performing the shifted-attention emotion appraisal task (SEAT), a test of emotional processing and regulation. Compared with placebo, DHEA reduced activity in the amygdala and hippocampus, enhanced connectivity between the amygdala and hippocampus, and enhanced activity in the rACC. These activation changes were associated with reduced negative affect. DHEA reduced memory accuracy for emotional stimuli, and also reduced activity in regions associated with conjunctive memory encoding. These results demonstrate that DHEA reduces activity in regions associated with generation of negative emotion and enhances activity in regions linked to regulatory processes. Considering that activity in these regions is altered in mood and anxiety disorders, our results provide initial neuroimaging evidence that DHEA may be useful as a pharmacological intervention for these conditions and invite further investigation into the brain basis of neurosteroid emotion regulatory effects.