Optimization of an anatomically and electrically detailed rodent subthalamic nucleus neuron model.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for Parkinson's disease, but its mechanisms of action remain unclear. Detailed multi-compartment computational models of STN neurons are often used to study how DBS electric fields modulate the neurons. However, currently available STN neuron models have some limitations in their biophysical realism. In turn, the goal of this study was to update a detailed rodent STN neuron model originally developed by Gillies & Willshaw [2006]. Our design requirements consisted of explicitly representing an axon connected to the neuron and updating the ion channel distributions based on the experimental literature to match established electrophysiological features of rodent STN neurons. We found that adding an axon to the STN neuron model substantially altered its firing characteristics. We then used a genetic algorithm to optimize the biophysical parameters of the model. The optimized model exhibited spontaneous firing, action potential shape, hyperpolarization response, and frequency-current curve that aligned well with experimental recordings from STN neurons. Subsequently, we evaluated the general compatibility of the updated biophysics by applying them to 26 different STN neuron morphologies derived from 3D anatomical reconstructions. The different morphologies affected the firing behavior of the model, but the updated biophysics were robustly capable of maintaining the desired electrophysiological features. The new STN neuron model developed in this work offers a valuable tool for studying STN neuron firing properties, and may find application in simulating STN local field potentials or analysis of the effects of STN DBS.

Coupled Activation of the Hyperdirect and Cerebellothalamic Pathways with Zona Incerta Deep Brain Stimulation.

BACKGROUND: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or ventral intermediate nucleus (VIM) are established targets for the treatment of Parkinson's disease (PD) or essential tremor (ET), respectively. However, DBS of the zona incerta (ZI) can be effective for both disorders. VIM DBS is assumed to achieve its therapeutic effect via activation of the cerebellothalamic (CBT) pathway, whereas the activation of the hyperdirect (HD) pathway likely plays a role in the mechanisms of STN DBS. Interestingly, HD pathway axons also emit collaterals to the ZI and red nucleus (RN) and the CBT pathway courses nearby to the ZI. OBJECTIVE: The aim was to examine the ability of ZI DBS to mutually activate the HD and CBT pathways in a detailed computational model of human DBS. METHODS: We extended a previous model of the human HD pathway to incorporate axon collaterals to the ZI and RN. The anatomical framework of the model system also included representations of the CBT pathway and internal capsule (IC) fibers of passage. We then performed detailed biophysical simulations to quantify DBS activation of the HD, CBT, and IC pathways with electrodes located in either the STN or ZI. RESULTS: STN DBS and ZI DBS both robustly activated the HD pathway. However, STN DBS was limited by IC activation at higher stimulus amplitudes. Alternatively, ZI DBS avoided IC activation while simultaneously activating the HD and CBT pathways. CONCLUSIONS: From both neuroanatomical and biophysical perspectives, ZI DBS represents an advantageous target for coupled activation of the HD and CBT pathways. © 2024 International Parkinson and Movement Disorder Society.

The contributions of clinical disease activity, functional disability, and illness intrusiveness to depressive symptoms in pediatric inflammatory bowel disease.

BACKGROUND: Clinical disease activity associated with inflammatory bowel disease (IBD) can place physical limitations on youths' activities of daily living. In turn, functional limitations potentially contribute to youths' heightened experience of IBD-induced intrusions on a wide range of routine and valued activities (i.e., illness intrusiveness), which can increase their risk for depressive symptoms. The present study examined the contributions of clinical disease activity, functional disability, and illness intrusiveness to depressive symptoms in youth with IBD. METHODS: Youth (N = 180) completed the Functional Disability Inventory (FDI), Illness Intrusiveness Scale-Child (IIS-C), and Children's Depression Inventory-2 (CDI-2). Physicians completed the Physicians Global Assessment of disease activity (PGA). RESULTS: Results revealed a mediating effect for functional disability in the association between disease activity and depressive symptoms (PGA → FDI → CDI-2); illness intrusiveness mediated the association between functional disability and depressive symptoms (i.e., FDI → IIS-C → CDI-2). Serial mediation revealed that clinical disease activity conferred an indirect effect on youth depressive symptoms through the sequential effects of functional disability and illness intrusiveness (i.e., PGA → FDI → IIS-C → CDI-2). CONCLUSIONS: Taken together, these findings indicate that youth who encounter more physical limitations as a function of clinical disease activity are more likely to experience an amplified sense of IBD-related intrusions on their ability to participate in meaningful activities. In turn, heightened illness intrusiveness increases the likelihood of depressive symptoms. Clinical interventions that help youth maintain adequate functional ability in the face of IBD disease activity and encourage involvement in positively valued activities could decrease the negative impact of IBD on youths' emotional adjustment.

Minimally invasive cytoreductive radical prostatectomy, exploring the safety and feasibility of a single-port or multi-port robotic platform.

BACKGROUND: Consolidative resection or cytoreductive radical prostatectomy (CRP) may benefit men with non-organ confined prostate cancer. We report the safety, feasibility, and outcomes of robot-assisted laparoscopic CRP using a single-port (SP) or multi-port (MP) platform. METHODS: We reviewed consecutive men with clinical node positive or metastatic castrate-sensitive prostate cancer who underwent IRB-approved CRP and extended pelvic lymph node dissection using the da Vinci SP or MP Surgical Systems (Intuitive Surgical, Sunnyvale, CA) from 2015-2022. Perioperative data and Clavien-Dindo 90-day complications were recorded. RESULTS: Twenty-four men with a median age of 61 (IQR 56-69) years and prostate-specific antigen of 32.1 (IQR 21.9-62.3) ng/mL were included. Clinical N1, M1, or N1 + M1 disease were detected in 8 (33%), 9 (38%), 7 (29%) patients, respectively. There was no difference in positive margins, 41% vs. 29% (P = 0.67), lymph node yield, 21 (IQR 14-28) vs. 20 (IQR 13.5-21) nodes (P = 0.31), or estimated blood loss, 150 mL (IQR 100-200) vs. 50 mL (IQR 50-125) (P = 0.06), between the MP and SP cohorts, respectively. Hospital length of stay was significantly shorter for the SP group, same-day discharge (IQR 0-0), compared to MP, 1-day (IQR 1-1), P < 0.001. One grade III bowel obstruction and lymphocele occurred in the MP cohort. No major complications occurred in the SP cohort. CONCLUSION: Robot-assisted laparoscopic CRP is safe and feasible for select men with advanced castrate-sensitive prostate cancer.

First-in-Class Humanized Antibody against Alternatively Spliced Tissue Factor Augments Anti-Metastatic Efficacy of Chemotherapy in a Preclinical Model of Pancreatic Ductal Adenocarcinoma.

Alternatively spliced tissue factor (asTF) promotes the progression of pancreatic ductal adenocarcinoma (PDAC) by activating ß1-integrins on PDAC cell surfaces. hRabMab1, a first-in-class humanized inhibitory anti-asTF antibody we recently developed, can suppress PDAC primary tumor growth as a single agent. Whether hRabMab1 has the potential to suppress metastases in PDAC is unknown. Following in vivo screening of three asTF-proficient human PDAC cell lines, we chose to make use of KRAS G12V-mutant human PDAC cell line PaCa-44, which yields aggressive primary orthotopic tumors with spontaneous spread to PDAC-relevant anatomical sites, along with concomitant severe leukocytosis. The experimental design featured orthotopic tumors formed by luciferase labeled PaCa-44 cells; administration of hRabMab1 alone or in combination with gemcitabine/paclitaxel (gem/PTX); and the assessment of the treatment outcomes on the primary tumor tissue as well as systemic spread. When administered alone, hRabMab1 exhibited poor penetration of tumor tissue; however, hRabMab1 was abundant in tumor tissue when co-administered with gem/PTX, which resulted in a significant decrease in tumor cell proliferation; leukocyte infiltration; and neovascularization. Gem/PTX alone reduced primary tumor volume, but not metastatic spread; only the combination of hRabMab1 and gem/PTX significantly reduced metastatic spread. RNA-seq analysis of primary tumors showed that the addition of hRabMab1 to gem/PTX enhanced the downregulation of tubulin binding and microtubule motor activity. In the liver, hRabMab1 reduced liver metastasis as a single agent. Only the combination of hRabMab1 and gem/PTX eliminated tumor cell-induced leukocytosis. We here demonstrate for the first time that hRabMab1 may help suppress metastasis in PDAC. hRabMab1's ability to improve the efficacy of chemotherapy is significant and warrants further investigation.

Potential utility of a multi-component coagulation factor panel to calculate MELD scores and assess the risk of portal vein thrombosis in chronic liver disease.

BACKGROUND: Current quantitative approaches to assess chronic liver disease (CLD) severity have limitations. Further, portal vein thrombosis (PVT) pre-liver transplant (LT) is a major contributor to morbidity in CLD; the means of detecting and/or predicting PVT are limited. We sought to explore whether plasma coagulation factor activity levels can serve as a substitute for prothrombin time/international normalized ratio (PT/INR) in the Model for End-stage Liver Disease (MELD), and/or help assess the risk of PVT. METHODS: Plasma activity levels of Factor V (FV), Factor VIII (FVIII), Protein C (PC), and Protein S (PS) and the concentrations of D-dimer, sP-selectin, and asTF were assessed in two cohorts of CLD patients (ambulatory, n = 42; LT, n = 43). RESULTS: FV and PC activity levels strongly correlated with MELD scores, which enabled the development of a novel scoring system based on multiple linear regressions of the correlations of FV and PC activity with MELD-Na that substitutes PT/INR. Six-month and 1-year follow-up revealed that our novel approach was non-inferior to MELD-Na at predicting mortality. A significant inverse correlation between FVIII activity levels and PVT was found in the LT cohort (p = 0.010); FV and PS activity levels were in-trend (p = 0.069, p = 0.064). We developed a logistic regression-based compensation score to identify patients at risk of PVT. CONCLUSIONS: We demonstrate that FV and PC activity levels may be used to replace PT/INR in MELD scoring. We also show the potential of using the combination of FV, FVIII, and PS activity levels to assess the risk of PVT in CLD.

Parental Uncertainty Scale Factor Structure in Pediatric DSD With Ambiguous Genitalia.

OBJECTIVE: Illness uncertainty is a salient experience for caregivers of children with disorders/differences of sex development (DSD) presenting with ambiguous genitalia; however, no validated measure of illness uncertainty exists for this unique population. Thus, the current study aimed to preliminarily identify the factor structure of the Parental Perception of Uncertainty Scale (PPUS) in caregivers of children with DSD presenting with ambiguous genitalia and examine the convergent validity of the PPUS. METHODS: Participants included 115 caregivers (Mage = 32.12 years, SD = 6.54; 57% mothers) of children (<2-year-olds) diagnosed with DSD participating in a larger, longitudinal study. Caregivers completed the PPUS as well as self-report measures of anxious, depressive, and posttraumatic stress symptoms. An exploratory factor analysis was conducted. RESULTS: Exploratory factor analysis results indicated that a 23-item 1-factor solution was the most parsimonious and theoretically sound factor structure (α = 0.92). Convergent validity analyses demonstrated further support for the use of the 23-item 1-factor solution over the original PPUS factor structure. CONCLUSION: These results demonstrate the preliminary clinical and research utility of the PPUS with caregivers of children with DSD presenting with ambiguous genitalia. The PPUS may benefit from further refinement through qualitative research and item adaptation to capture uncertainties unique to DSD presenting with ambiguous genitalia. In addition, future research should replicate the proposed factor structure using confirmatory factor analysis with a separate, larger sample of caregivers of children with DSD to confirm the factor structure.

Comparative Long-Wave Infrared Laser-Induced Breakdown Spectroscopy Employing 1-D and 2-D Focal Plane Array Detectors.

Long-wave infrared (LWIR) emissions of laser-induced plasma on solid potassium chloride and acetaminophen tablet surfaces were studied using both a one-dimensional (1-D) linear array detection system and, for the first time, a two-dimensional (2-D) focal plane array (FPA) detection system. Both atomic and molecular infrared emitters in the vicinity of the plasma were identified by analyzing the detected spectral signatures in the infrared region. Time- and space-resolved long-wave infrared emissions were also studied to assess the temporal and spatial behaviors of atomic and molecular emitters in the plasma. These pioneer temporal and spatial investigations of infrared emissions from laser-induced plasma would be valuable to the modeling of plasma evolutions and the advances of the novel LWIR laser-induced breakdown spectroscopy (LIBS). When integrated both temporally (≥200 µs) and spatially using a 2-D FPA detector, the observed intensities and signal-to-noise-ratio (SNR) of single-shot LWIR LIBS signature emissions from intact molecules were considerably enhanced (e.g., with enhancement factors up to 16 and 3.76, respectively, for a 6.62 µm band of acetaminophen molecules) and, in general, comparable to those from the atomic emitters. Pairing LWIR LIBS with conventional ultraviolet-visible-near infrared (UV/Vis/NIR) LIBS, a simultaneous UV/Vis/NIR + LWIR LIBS detection system promises unprecedented capability of in situ, real-time, and stand-off investigation of both atomic and molecular target compositions to detect and characterize a range of chemistries.

The Combined Effects of Youth and Parent Illness Intrusiveness on Depressive Symptoms in Adolescents with Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) presents physical and emotional challenges for families and imposes significant lifestyle intrusions on both youth and parents. The present study examined the effects of IBD disease activity and youth illness intrusiveness on depressive symptoms in adolescents, and the moderating influence of parent illness intrusiveness on these associations. Adolescents and parents completed measures of illness intrusiveness; youth completed a measure of depressive symptoms. Physicians provided estimates of IBD disease activity. Mediation analysis revealed an IBD disease activity → youth intrusiveness → youth depressive symptoms indirect effect. Moderated mediation analyses revealed this indirect effect to be greater among youth whose parents endorsed more IBD-related intrusions. Youth encountering greater activity disruptions related to IBD are vulnerable to depressive symptoms. When parents also experience IBD-induced intrusions, youth are at even greater risk for depressive symptoms. Clinical implications are discussed within the context of youths' and parents' experiences of IBD.

Subthalamic deep brain stimulation of an anatomically detailed model of the human hyperdirect pathway.

The motor hyperdirect pathway (HDP) is considered a key target in the treatment of Parkinson's disease with subthalamic deep brain stimulation (DBS). This hypothesis is partially derived from the association of HDP activation with evoked potentials (EPs) generated in the motor cortex and subthalamic nucleus (STN) after a DBS pulse. However, the biophysical details of how and when DBS-induced action potentials (APs) in HDP neurons reach their terminations in the cortex or STN remain unclear. Therefore, we used an anatomically detailed representation of the motor HDP, as well as the internal capsule (IC), in a model of human subthalamic DBS to explore AP activation and transmission in the HDP and IC. Our results show that small diameter HDP axons exhibited AP initiation in their subthalamic terminal arbor, which resulted in relatively long transmission latencies to cortex (∼3.5-8 ms). Alternatively, large diameter HDP axons were most likely to be directly activated in the capsular region, which resulted in short transmission times to the cortex (∼1-3 ms). However, those large diameter HDP antidromic APs would be indistinguishable from any other IC axons that were also activated by the stimulus. Conversely, DBS-induced APs in both small and large diameter HDP axons reached their synaptic boutons in the STN with similar timings, but both spanned a wide temporal range (∼0.5-5 ms). We also found that using anodic or bipolar stimulation helped to bias activation of the HDP over the IC. These computational results provide useful information for linking HDP activation with EP recordings in clinical experiments.NEW & NOTEWORTHY We used biophysical models to study pathway recruitment and conduction latencies of the hyperdirect pathway (HDP) in response to subthalamic deep brain stimulation (DBS). The model system allowed us to assess the influence of increased anatomical realism on pathway activity and the possibility of identifying HDP activity in evoked potentials (EPs) recorded in either the subthalamic nucleus (STN) or cortex. The model predicts that HDP activation is accentuated by complex axonal branching in the STN.

Self-expanding intestinal expansion sleeves (IES) for short gut syndrome.

PURPOSE: Many disease processes (necrotizing enterocolitis, caustic esophageal injury, malrotation with volvulus), can result in short-gut syndrome (SGS), where remnant intestinal segments may dilate axially, but rarely elongate longitudinally. Here we mechanically characterize a novel model of a self-expanding mesh prototype intestinal expanding sleeve (IES) for use in SGS. METHODS: Gut lengthening was achieved using a proprietary cylindrical layered polyethylene terephthalate IES device with helicoid trusses with isometric ends. The IES is pre-contracted by diametric expansion, deployed into the gut and anchored with bioabsorbable sutures. IES expansion to its equilibrium dimension maintained longitudinal gut tension, which may permit remodeling, increased absorptive surface area while preserving vascular and nervous supplies. We performed mechanical testing to obtain the effective force-displacement characterization achieved on these prototypes and evaluated minimal numbers of sutures needed for its anchoring. Furthermore, we deployed these devices in small and large intestines of New Zealand White rabbits, measured IES length-tension relationships and measured post-implant gut expansion ex vivo. Histology of the gut before and after implantation was also evaluated. RESULTS: Longitudinal tension using IES did not result in suture failure. Maximum IES suture mechanical loading was tested using 4-6 sutures; we found similar failure loads of 2.95 ± 0.64, 4 ± 1.9 and 3.16 ± 0.24 Newtons for 4, 6 and 8 sutures, respectively (n = 3, n.s). Pre-contracted IES tubes were deployed at 67 ± 4% of initial length (i.l.); in the large bowel these expanded significantly to 81.5 ± 3.7% of i.l. (p = 0.014, n = 4). In the small bowel, pre-contracted IES were 61 ± 3.8% of i.l.; these expanded significantly to 82.7 ± 7.4% of i.l. (p = 0.0009, n = 6). This resulted in an immediate 24 ± 7.8% and 36.2 ± 11% increase in gut length when deployed in large and small bowels, respectively, with maintained longitudinal tension. Maintained IES induced tension produced gut wall thinning; gut histopathological evaluation is currently under evaluation. CONCLUSION: IES is a versatile platform for gaining length in SGS, which may be simply deployed via feeding tubes. Our results need further validation for biocompatibility and mechanical characterization to optimize use in gut expansion.

Improved Neutron Lifetime Measurement with UCNτ.

We report an improved measurement of the free neutron lifetime τ_{n} using the UCNτ apparatus at the Los Alamos Neutron Science Center. We count a total of approximately 38×10^{6} surviving ultracold neutrons (UCNs) after storing in UCNτ's magnetogravitational trap over two data acquisition campaigns in 2017 and 2018. We extract τ_{n} from three blinded, independent analyses by both pairing long and short storage time runs to find a set of replicate τ_{n} measurements and by performing a global likelihood fit to all data while self-consistently incorporating the ß-decay lifetime. Both techniques achieve consistent results and find a value τ_{n}=877.75±0.28_{stat}+0.22/-0.16_{syst} s. With this sensitivity, neutron lifetime experiments now directly address the impact of recent refinements in our understanding of the standard model for neutron decay.

Identifying Toxicologically Significant Compounds in Urban Wildfire Ash Using In Vitro Bioassays and High-Resolution Mass Spectrometry.

Urban wildfires may generate numerous unidentified chemicals of toxicity concern. Ash samples were collected from burned residences and from an undeveloped upwind reference site, following the Tubbs fire in Sonoma County, California. The solvent extracts of ash samples were analyzed using GC- and LC-high-resolution mass spectrometry (HRMS) and using a suite of in vitro bioassays for their bioactivity toward nuclear receptors [aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and androgen receptor (AR)], their influence on the expression of genetic markers of stress and inflammation [interleukin-8 (IL-8) and cyclooxygenase-2 (COX-2)], and xenobiotic metabolism [cytochrome P4501A1 (CYP1A1)]. Genetic markers (CYP1A1, IL-8, and COX-2) and AhR activity were significantly higher with wildfire samples than in solvent controls, whereas AR and ER activities generally were unaffected or reduced. The bioassay responses of samples from residential areas were not significantly different from the samples from the reference site despite differing chemical compositions. Suspect and nontarget screening was conducted to identify the chemicals responsible for elevated bioactivity using the multiple streams of HRMS data and open-source data analysis workflows. For the bioassay endpoint with the largest available database of pure compound results (AhR), nontarget features statistically related to whole sample bioassay response using Spearman's rank-order correlation coefficients or elastic net regression were significantly more likely (by 10 and 15 times, respectively) to be known AhR agonists than the overall population of compounds tentatively identified by nontarget analysis. The findings suggest that a combination of nontarget analysis, in vitro bioassays, and statistical analysis can identify bioactive compounds in complex mixtures.

Illness Stigma, Worry, Intrusiveness, and Depressive Symptoms in Youth With Inflammatory Bowel Disease.

BACKGROUND: Youth who experience IBD-associated stigma may manifest increased worry about aversive symptoms that can intrude on their participation in routine activities (eg, school, social events), potentially resulting in limited opportunities for reinforcement and increased depressive symptoms. The present study examined an IBD stigma → IBD worry → illness intrusiveness → depressive symptoms serial mediation model, in which stigma was hypothesized to confer an indirect effect on youth depressive symptoms through the serial effects of stigma on IBD worry and illness intrusiveness. METHODS: Youth with IBD (N = 90) between the ages of 10 and 18 years were recruited from a pediatric gastroenterology clinic and completed measures of IBD stigma, IBD worry, illness intrusiveness, and depressive symptoms. RESULTS: In addition to several independent direct effects among the modeled variables, results revealed a significant IBD stigma → IBD worry → illness intrusiveness → depressive symptoms serial mediation path (effect = 0.63, 95% CI = 0.22 to 1.20), controlling for youth sex and IBD severity. CONCLUSIONS: The experience of IBD-related stigma may prompt increased worry about IBD symptoms, independent of the influence of disease activity. Further, heightened worry appears to amplify youths' experience of IBD-imposed limitations on routine and rewarding activities, increasing their risk for experiencing depressive symptoms. Our findings highlight the importance of regular screening for depressive symptoms, as well as the identification of potential risk factors associated with emotional adjustment difficulties. Stigma-specific treatment modules could be integrated within existing cognitive-behavioral approaches for reducing worry and depressive symptoms in youth with IBD.

Relationship Between Caregiver Uncertainty, Problem-Solving, and Psychological Adjustment in Pediatric Cancer.

OBJECTIVE: The current study examined the roles of constructive and dysfunctional problem-solving strategies in the relationships between illness uncertainty and adjustment outcomes (i.e., anxious, depressive, and posttraumatic stress symptoms) in caregivers of children newly diagnosed with cancer. METHODS: Two hundred thirty-eight caregivers of children (0-19 years of age) newly diagnosed with cancer (2-14 weeks since diagnosis) completed measures of illness uncertainty, problem-solving strategies, and symptoms of anxiety, depression, and posttraumatic stress. RESULTS: A mediation model path analysis assessed constructive and dysfunctional problem-solving strategies as mediators between illness uncertainty and caregiver anxious, depressive, and posttraumatic stress symptoms. Dysfunctional problem-solving scores partially mediated the relationships between illness uncertainty and anxious, depressive, and posttraumatic stress symptoms. Constructive problem-solving scores did not mediate these relationships. CONCLUSIONS: The current findings suggest that illness uncertainty and dysfunctional problem-solving strategies, but not constructive problem-solving strategies, may play a key role in the adjustment of caregivers of children newly diagnosed with cancer. Interventions aimed at managing illness uncertainty and mitigating the impact of dysfunctional problem-solving strategies may promote psychological adjustment.

Stigma by Association: Parent Stigma and Youth Adjustment in Inflammatory Bowel Disease.

OBJECTIVE: Examine the indirect association between parents' experience of stigma (i.e., associative stigma) and youth depressive symptoms through the serial effects of associative stigma on parent and youth illness intrusiveness in pediatric inflammatory bowel disease (IBD). METHODS: During routine clinic visits, 150 youth with well-controlled IBD (ages 10-18 years) completed measures of perceived illness intrusiveness and depressive symptoms. Parents completed measures of associative stigma and illness intrusiveness. Pediatric gastroenterologists provided ratings of IBD disease severity. RESULTS: Structural equation modeling revealed significant direct associations for associative stigma → parent illness intrusiveness, parent illness intrusiveness → youth illness intrusiveness, and youth illness intrusiveness → youth depressive symptoms. Results also revealed a significant associative stigma → parent illness intrusiveness → youth illness intrusiveness→ youth depressive symptoms serial mediation path, indicating that parents' experience of associative stigma indirectly influenced youth depressive symptoms through its sequential effects on parent and youth perceived illness intrusiveness. CONCLUSIONS: Parents who face stigma related to their child's IBD (i.e., associative stigma) are more likely to experience IBD-induced lifestyle intrusions (i.e., illness intrusiveness), which in turn is associated with youths' illness intrusiveness and ultimately youth depressive symptoms. These findings provide further evidence for the important role of illness-related stigma in pediatric IBD, particularly the transactional relation between parents' associative stigma and youths' illness appraisals and emotional functioning. The clinical implications of our results for addressing adjustment difficulties in youth with IBD are also discussed.

Enhanced Efficacy of Combination of Gemcitabine and Phosphatidylserine-Targeted Nanovesicles against Pancreatic Cancer.

Phosphatidylserine (PS) is often externalized in viable pancreatic cancer cells and is therapeutically targetable using PS-selective drugs. One of the first-line treatments for advanced pancreatic cancer disease, gemcitabine (GEM), provides only marginal benefit to patients. We therefore investigated the therapeutic benefits of combining GEM and the PS-targeting drug, saposin C-dioleoylphosphatidylserine (SapC-DOPS), for treating pancreatic ductal adenocarcinoma (PDAC). Using cell-cycle analyses and a cell surface PS-based sorting method in vitro, we observed an increase in surface PS as cells progress through the cell cycle from G1 to G2/M. We also observed that GEM treatment preferentially targets G1 phase cells that have low surface PS, resulting in an increased median surface PS level of PDAC cells. Inversely, SapC-DOPS preferentially targets high surface PS cells that are predominantly in the G2/M phase. Finally, combination therapy in subcutaneous and orthotopic PDAC tumors in vivo with SapC-DOPS and GEM or Abraxane (Abr)/GEM (one of the current standards of care) significantly inhibits tumor growth and increases survival compared with individual treatments. Our studies confirm a surface PS and cell cycle-based enhancement of cancer cytotoxicity following SapC-DOPS treatment in combination with GEM or Abr/GEM. Thus, PDAC patients treated with Abr/GEM may benefit from concurrent administration of SapC-DOPS.

External carotid artery pseudoaneurysm following upper respiratory infection masquerading as a pharyngeal abscess in an 8-month-old.

Pseudoaneurysms are very rare with an incidence of less than 0.1% in the pediatric population. Approximately 30 cases of carotid artery aneurysms in children have been published in the literature, usually affecting children over one year of age. We present one of the youngest cases in the literature; the patient is an 8-month old female with a strep throat infection complicated by pseudoaneurysm development of the external carotid artery. Because of the rarity of these lesions, there is little known regarding the types of clinical presentation and management. They are commonly the result of direct arterial trauma; however, they can also occur secondary to infection, connective tissue disease or arteritis. We are presenting a case with a highly atypical presentation. When present, pseudoaneurysms harbor the potential risk of life-threatening hemorrhage and warrant immediate management. It is important to be aware of cases and the treatment modalities used to guide future diagnosis and planning.

The Role of Avoidance Coping and Illness Uncertainty in the Relationship Between Transition Readiness and Health Anxiety.

PURPOSE: The transition to college is associated with numerous stressors, including environmental changes, increased academic expectations, and changes in social support, all of which may be exacerbated by the added responsibility of managing a chronic medical condition. Huang (2019) proposed a model examining the relationships between coping styles, transition readiness, and health anxiety, and suggested that greater transition readiness is associated with adaptive coping strategies and less health anxiety. However, there are limited findings as to how poor transition readiness relates to health anxiety. Therefore, the current study tested a serial mediation model (i.e., poor transition readiness → avoidance coping → illness uncertainty → health anxiety). DESIGN AND METHODS: College students (N = 194) with a chronic medical condition completed self-report questionnaires. RESULTS: Results indicated several direct effects among the modeled variables and a significant poor transition readiness → avoidance coping → illness uncertainty → health anxiety serial mediation (path a1d21b2 = 0.438, 95% CI = 0.153 to 0.913). CONCLUSIONS: Worse transition readiness was associated with increased avoidance as a coping mechanism, which in turn is associated with increased illness uncertainty, and ultimately health anxiety. The current findings identified possible drivers of health anxiety in college students with a chronic medical condition. PRACTICE IMPLICATIONS: These findings highlight that good transition readiness skills may buffer against maladaptive avoidance, illness uncertainty, and health anxiety. Modules aimed at improving healthcare management, avoidance, and illness uncertainty may be beneficial additions to interventions to reduce health anxiety.

Stigma Moderates the Relation Between Peer Victimization, Thwarted Belongingness, and Depressive Symptoms in Youth with Inflammatory Bowel Disease.

PURPOSE: The stigmatizing nature of IBD symptoms may place youth at risk for being targets of peer victimization, potentially resulting in a decreased sense of social belongingness and poorer emotional adjustment. The present study tested a series of mediation and moderated mediation models examining the associations among peer victimization, thwarted social belongingness, and depressive symptoms, as well as the moderating role of IBD stigma in these associations. We hypothesized peer victimization would have an indirect effect on youth depressive symptoms through thwarted belongingness, and this effect would be amplified for youth endorsing greater IBD stigma. DESIGN AND METHODS: Seventy-five youth (10-18 yrs.) diagnosed with IBD were recruited from a pediatric gastroenterology clinic. Participants completed self-report measures of IBD stigma, peer victimization, thwarted belongingness, and depressive symptoms. RESULTS: As anticipated, mediation analyses revealed a significant peer victimization → thwarted belongingness → depressive symptoms indirect path. Moderated mediation analyses indicated that this indirect effect was moderated by IBD stigma and was significantly greater among youth reporting higher IBD stigma. CONCLUSIONS: Youth who experience higher levels of IBD-related stigma are at increased risk for depressive symptoms as a function of the socially isolating effects of peer victimization. PRACTICE IMPLICATIONS: Our findings highlight the need for routine screening and identification of the socioemotional challenges faced by youth with IBD. Clinical interventions that incorporate coping strategies aimed at minimizing youths' stigmatizing self-perceptions and improving overall social skills and social engagement may lessen the negative impact of peer victimization on youths' social and emotional adjustment.