TARGETING SOLUBLE AMYLOID-BETA OLIGOMERS WITH A NOVEL NANOBODY.

The classical amyloid cascade hypothesis postulates that the aggregation of amyloid plaques and the accumulation of intracellular hyperphosphorylated Tau tangles, together, lead to profound neuronal death. However, emerging research has demonstrated that soluble amyloid-ß oligomers (SAßOs) accumulate early, prior to amyloid plaque formation. SAßOs induce memory impairment and disrupt cognitive function independent of amyloid-ß plaques, and even in the absence of plaque formation. This work describes the development and characterization of a novel anti-SAßO (E3) nanobody generated from an alpaca immunized with SAßO. In-vitro assays and in-vivo studies using 5XFAD mice indicate that the fluorescein (FAM)-labeled E3 nanobody recognizes both SAßOs and amyloid-ß plaques. The E3 nanobody traverses across the blood-brain barrier and binds to amyloid species in the brain of 5XFAD mice. Imaging of mouse brains reveals that SAßO and amyloid-ß plaques are not only different in size, shape, and morphology, but also have a distinct spatial distribution in the brain. SAßOs are associated with neurons, while amyloid plaques reside in the extracellular matrix. The results of this study demonstrate that the SAßO nanobody can serve as a diagnostic agent with potential theragnostic applications in Alzheimer's disease.

Projected Colorectal Cancer Incidence and Mortality Based on Observed Adherence to Colonoscopy and Sequential Stool-Based Screening.

INTRODUCTION: Modeling supporting recommendations for colonoscopy and stool-based colorectal cancer (CRC) screening tests assumes 100% sequential participant adherence. The impact of observed adherence on the long-term effectiveness of screening is unknown. We evaluated the effectiveness of a program of screening colonoscopy every 10 years vs annual high-sensitivity guaiac-based fecal occult blood testing (HSgFOBT) using observed sequential adherence data. METHODS: The MIcrosimulation SCreening ANalysis (MISCAN) model used observed sequential screening adherence, HSgFOBT positivity, and diagnostic colonoscopy adherence in HSgFOBT-positive individuals from the National Colonoscopy Study (single-screening colonoscopy vs ≥4 HSgFOBT sequential rounds). We compared CRC incidence and mortality over 15 years with no screening or 10 yearly screening colonoscopy vs annual HSgFOBT with 100% and differential observed adherence from the trial. RESULTS: Without screening, simulated incidence and mortality over 15 years were 20.9 (95% probability interval 15.8-26.9) and 6.9 (5.0-9.2) per 1,000 participants, respectively. In the case of 100% adherence, only screening colonoscopy was predicted to result in lower incidence; however, both tests lowered simulated mortality to a similar level (2.1 [1.6-2.9] for screening colonoscopy and 2.5 [1.8-3.4] for HSgFOBT). Observed adherence for screening colonoscopy (83.6%) was higher than observed sequential HSgFOBT adherence (73.1% first round; 49.1% by round 4), resulting in lower simulated incidence and mortality for screening colonoscopy (14.4 [10.8-18.5] and 2.9 [2.1-3.9], respectively) than HSgFOBT (20.8 [15.8-28.1] and 3.9 [2.9-5.4], respectively), despite a 91% adherence to diagnostic colonoscopy with FOBT positivity. The relative risk of CRC mortality for screening colonoscopy vs HSgFOBT was 0.75 (95% probability interval 0.68-0.80). Findings were similar in sensitivity analyses with alternative assumptions for repeat colonoscopy, test performance, risk, age, and projection horizon. DISCUSSION: Where sequential adherence to stool-based screening is suboptimal and colonoscopy is accessible and acceptable-as observed in the national colonoscopy study, microsimulation, comparative effectiveness, screening recommendations.

Randomized Trial of Facilitated Adherence to Screening Colonoscopy vs Sequential Fecal-Based Blood Test.

BACKGROUND & AIMS: Colorectal cancer (CRC) screening guidelines include screening colonoscopy and sequential high-sensitivity fecal occult blood testing (HSgFOBT), with expectation of similar effectiveness based on the assumption of similar high adherence. However, adherence to screening colonoscopy compared with sequential HSgFOBT has not been reported. In this randomized clinical trial, we assessed adherence and pathology findings for a single screening colonoscopy vs sequential and nonsequential HSgFOBTs. METHODS: Participants aged 40-69 years were enrolled at 3 centers representing different clinical settings. Participants were randomized into a single screening colonoscopy arm vs sequential HSgFOBT arm composed of 4-7 rounds. Initial adherence to screening colonoscopy and sequential adherence to HSgFOBT, follow-up colonoscopy for positive HSgFOBT tests, crossover to colonoscopy, and detection of advanced neoplasia or large serrated lesions (ADN-SERs) were measured. RESULTS: There were 3523 participants included in the trial; 1761 and 1762 participants were randomized to the screening colonoscopy and HSgFOBT arms, respectively. Adherence was 1473 (83.6%) for the screening colonoscopy arm vs 1288 (73.1%) for the HSgFOBT arm after 1 round (relative risk [RR], 1.14; 95% CI, 1.10-1.19; P ≤ .001), but only 674 (38.3%) over 4 sequential HSgFOBT rounds (RR, 2.19; 95% CI, 2.05-2.33). Overall adherence to any screening increased to 1558 (88.5%) in the screening colonoscopy arm during the entire study period and 1493 (84.7%) in the HSgFOBT arm (RR, 1.04; 95% CI, 1.02-1.07). Four hundred thirty-six participants (24.7%) crossed over to screening colonoscopy during the first 4 rounds. ADN-SERs were detected in 121 of the 1473 participants (8.2%) in the colonoscopy arm who were adherent to protocol in the first 12 months of the study, whereas detection of ADN-SERs among those who were not sequentially adherent (n = 709) to HSgFOBT was subpar (0.6%) (RR, 14.72; 95% CI, 5.46-39.67) compared with those who were sequentially adherent (3.3%) (n = 647) (RR, 2.52; 95% CI, 1.61-3.98) to HSgFOBT in the first 4 rounds. When including colonoscopies from HSgFOBT patients who were never positive yet crossed over (n = 1483), 5.5% of ADN-SERs were detected (RR, 1.50; 95% CI, 1.15-1.96) in the first 4 rounds. CONCLUSIONS: Observed adherence to sequential rounds of HSgFOBT was suboptimal compared with a single screening colonoscopy. Detection of ADN-SERs was inferior when nonsequential HSgFOBT adherence was compared with sequential adherence. However, the greatest number of ADN-SERs was detected among those who crossed over to colonoscopy and opted to receive a colonoscopy. The effectiveness of an HSgFOBT screening program may be enhanced if crossover to screening colonoscopy is permitted. CLINICALTRIALS: gov, Number: NCT00102011.

Nanobodies as Probes and Modulators of Cardiovascular G Protein-Coupled Receptors.

ABSTRACT: Understanding the activation of G protein-coupled receptors (GPCRs) is of paramount importance to the field of cardiovascular medicine due to the critical physiological roles of these receptors and their prominence as drug targets. Although many cardiovascular GPCRs have been extensively studied as model receptors for decades, new complexities in their regulation continue to emerge. As a result, there is an ongoing need to develop novel approaches to monitor and to modulate GPCR activation. In less than a decade, nanobodies, or recombinant single-domain antibody fragments from camelids, have become indispensable tools for interrogating GPCRs both in purified systems and in living cells. Nanobodies have gained traction rapidly due to their biochemical tractability and their ability to recognize defined states of native proteins. Here, we review how nanobodies have been adopted to elucidate the structure, pharmacology, and signaling of cardiovascular GPCRs, resolving long-standing mysteries and revealing unexpected mechanisms. We also discuss how advancing technologies to discover nanobodies with tailored specificities may expand the impact of these tools for both basic science and therapeutic applications.

Mediation of outcomes for cognitive behavioral therapy targeted to parents of children with Functional Abdominal Pain Disorders.

OBJECTIVE: There is a large body of evidence for the efficacy of Cognitive Behavioral Therapy (CBT) in treating Functional Abdominal Pain Disorders (FAPD) in children. In most CBT interventions for FAPD, parents participate together with their children. However, only one study to date has examined targeting parents alone for treatment. The aim of the current study was to examine mediators of a parent-only CBT treatment incorporating social learning (SLCBT) for FAPD in children. METHODS: We examined mediators of child outcomes in an existing randomized controlled trial (n = 316) of parent-only social learning CBT compared to an education condition. Hypothesized mediators (parental protectiveness, perceived threat of pain, catastrophizing) were assessed at 3 months post-treatment, and outcomes (parent ratings of disability, quality of life, school absences, and health care visits) were assessed at 6 months post-treatment. Mediation analyses were performed using Hayes' PROCESS macro. RESULTS: Pain catastrophizing significantly mediated treatment effects for all outcomes (B ranged from -1.65 to 2.22). Reduction in pain threat was a significant mediator for all outcomes (B ranged from -1.84 to 3.13) except school absences and health care visits. Decrease in parental protectiveness mediated effects on disability and missed school (B ranged from -1.47 to 1.34). Mediation effects did not differ by in-person or remote delivery of SLCBT. CONCLUSION: Changes in maladaptive parental thoughts and behaviors following parent-only SLCBT intervention appeared to mediate the effects of the intervention. Parental catastrophizing appears to be a particularly important target given that decreases in that variable mediated all outcomes.

Do Nontechnical Skills Affect Legal Outcomes After Endoscopic Perforations?

INTRODUCTION: Health systems often emphasize technical skills to reduce iatrogenic injuries. Nontechnical skills such as clinical and communication skills are mostly overlooked or not readily retrievable from medical records. Our aim was to estimate the association of technical and nontechnical skills of endoscopists with indemnity payments to patients after endoscopic perforations. METHODS: This is an observational registry-based study of closed claims against gastroenterologists involved in endoscopic perforations. RESULTS: We analyzed 175 closed claims related to perforations, all of which involved allegations of improper performance of the endoscopic procedure. Inadequate communication (n = 71, 41%) and clinical judgment (n = 60, 34%) on the part of the endoscopists were observed. Inadequate communication and clinical judgment were associated with over 3-fold odds of indemnity payment (odds ratio [OR] 3.31; 95% confidence interval [CI], 1.46-7.48, and OR 3.18; 95% CI, 1.44-7.01, respectively). However, if there were no communication breakdown or clinical judgment issues and the only allegation was poor technical skill, the odds of indemnity payments were less than half of those cases (OR 0.43; 95% CI 0.15-0.80). There was no evidence of a statistically significant interaction among age, procedure type, trainee involvement, clinical severity, need for surgery, and procedure-related death. DISCUSSION: We observed that inadequate communication and clinical judgment were associated with indemnity payment, independent of the severity of clinical outcomes. On the other hand, cases wherein there was an allegation of poor technical skills alone, without communication breakdown or clinical judgment issues, were associated with favorable legal outcomes for the defendant. (See the Visual Abstract at http://links.lww.com/AJG/B568.).

Expression, Solubilization, and Purification of Eukaryotic Borate Transporters.

The Solute Carrier 4 (SLC4) family of proteins is called the bicarbonate transporters and includes the archetypal protein Anion Exchanger 1 (AE1, also known as Band 3), the most abundant membrane protein in the red blood cells. The SLC4 family is homologous with borate transporters, which have been characterized in plants and fungi. It remains a significant technical challenge to express and purify membrane transport proteins to homogeneity in quantities suitable for structural or functional studies. Here we describe detailed procedures for the overexpression of borate transporters in Saccharomyces cerevisiae, isolation of yeast membranes, solubilization of protein by detergent, and purification of borate transporter homologs from S. cerevisiae, Arabidopsis thaliana, and Oryza sativa. We also detail a glutaraldehyde cross-linking experiment to assay multimerization of homomeric transporters. Our generalized procedures can be applied to all three proteins and have been optimized for efficacy. Many of the strategies developed here can be utilized for the study of other challenging membrane proteins.

Maladaptive Coping and Depressive Symptoms Partially Explain the Association Between Family Stress and Pain-Related Distress in Youth With IBD.

Objective: To extend existing research on the pain burden experienced by youth with inflammatory bowel disease (IBD) by examining the complexity of psychosocial factors involved in pain-related distress. Methods: Parents completed measures of family stress and their child's pain-related expressions of distress and coping. Youth with IBD rated their depressive symptoms (n = 183 dyads). Mediation analyses were performed using regression-based techniques and bootstrapping. Results: Greater family stress was positively related to children's pain-related expressions of distress and passive coping. Significant indirect effects were found in the relationship between family stress and expressed pain-related distress through parent-reported passive coping, depressive symptoms, and both passive coping and depressive symptoms sequentially. Conclusions: Results suggest that family stress can place children at risk for greater expressed pain-related distress through effects on coping and depressive symptoms. Addressing psychosocial difficulties is important for closing the gap between disability and health in youth with IBD.

Brief telephone-delivered cognitive behavioral therapy targeted to parents of children with functional abdominal pain: a randomized controlled trial.

Pediatric functional abdominal pain disorders (FAPDs) are associated with increased health care utilization, school absences, and poor quality of life (QoL). Cost-effective and accessible interventions are needed. This multisite study tested the effects of a 3-session cognitive behavioral intervention delivered to parents, in-person or remotely, on the primary outcome of pain severity and secondary outcomes (process measures) of parental solicitousness, pain beliefs, catastrophizing, and child-reported coping. Additional outcomes hypothesized a priori and assessed included functional disability, QoL, pain behavior, school absences, health care utilization, and gastrointestinal symptoms. The study was prospective and longitudinal (baseline and 3 and 6 months' follow-up) with 3 randomized conditions: social learning and cognitive behavioral therapy in-person (SLCBT) or by phone (SLCBT-R) and education and support condition by phone (ES-R). Participants were children aged 7 to 12 years with FAPD and their parents (N = 316 dyads). Although no significant treatment effect for pain severity was found, the SLCBT groups showed significantly greater improvements compared with controls on process measures of parental solicitousness, pain beliefs, and catastrophizing, and additional outcomes of parent-reported functional disability, pain behaviors, child health care visits for abdominal pain, and (remote condition only) QoL and missed school days. No effects were found for parent and child-reported gastrointestinal symptoms, or child-reported QoL or coping. These findings suggest that for children with FAPD, a brief phone SLCBT for parents can be similarly effective as in-person SLCBT in changing parent responses and improving outcomes, if not reported pain and symptom report, compared with a control condition.

Endoscopic Sedation: Medicolegal Considerations.

Goals of endoscopic sedation are to provide patients with a successful procedure, and ensure that they remain safe and are relieved from anxiety and discomfort; agents should provide efficient, appropriate sedation and allow patients to recover rapidly. Sedation is usually safe and effective; however, complications may ensue. This paper outlines some medicolegal aspects of endoscopic sedation, including informed consent, possible withdrawal of consent during the procedure, standard of care for monitoring sedation, use of anesthesia personnel to deliver sedation, and new agents and devices.

Time to Put Managing Endoscopic Complications Into the Curriculum.

Proper management of complications is critical to ensure the best outcome for both the patient and the physician. The physician's response to the error or complication, promptly informing the patient and the family, and expressing empathy at the situation, ensuring transparency and excellent post-complication care, is a critical determinant of the patient's understanding of the complication, perception of the physician, and, often, the decision to sue. Articles outlining best practice approach to various legal and risk management issues may aid physicians to acquire useful skills to help their patients.

Psychosocial mechanisms for the transmission of somatic symptoms from parents to children.

AIM: To examine familial aggregation of irritable bowel syndrome (IBS) via parental reinforcement/modeling of symptoms, coping, psychological distress, and exposure to stress. METHODS: Mothers of children between the ages of 8 and 15 years with and without IBS were identified through the Group Health Cooperative of Puget Sound. Mothers completed questionnaires, including the Child Behavior Checklist (child psychological distress), the Family Inventory of Life Events (family exposure to stress), SCL-90R (mother psychological distress), and the Pain Response Inventory (beliefs about pain). Children were interviewed separately from their parents and completed the Pain Beliefs Questionnaire (beliefs about pain), Pain Response Inventory (coping) and Child Symptom Checklist [gastrointestinal (GI) symptoms]. In addition, health care utilization data was obtained from the automated database of Group Health Cooperative. Mothers with IBS (n = 207) and their 296 children were compared to 240 control mothers and their 335 children, while controlling for age and education. RESULTS: Hypothesis 1: reinforcement of expression of GI problems is only related to GI symptoms, but not others (cold symptoms) in children. There was no significant correlation between parental reinforcement of symptoms and child expression of GI or other symptoms. Hypothesis 2: modeling of GI symptoms is related to GI but not non-GI symptom reporting in children. Children of parents with IBS reported more non-GI (8.97 vs 6.70, P < 0.01) as well as more GI (3.24 vs 2.27, P < 0.01) symptoms. Total health care visits made by the mother correlated with visits made by the child (rho = 0.35, P < 0.001 for cases, rho = 0.26, P < 0.001 for controls). Hypothesis 3: children learn to share the methods of coping with illness that their mothers exhibit. Methods used by children to cope with stomachaches differed from methods used by their mothers. Only 2/16 scales showed weak but significant correlations (stoicism rho = 0.13, P < 0.05; acceptance rho = 0.13, P < 0.05). Hypothesis 4: mothers and children share psychological traits such as anxiety, depression, and somatization. Child psychological distress correlated with mother's psychological distress (rho = 0.41, P < 0.001 for cases, rho= 0.38, P < 0.001 for controls). Hypothesis 5: stress that affects the whole family might explain the similarities between mothers and their children. Family exposure to stress was not a significant predictor of children's symptom reports. Hypothesis 6: the intergenerational transmission of GI illness behavior may be due to multiple mechanisms. Regression analysis identified multiple independent predictors of the child's GI complaints, which were similar to the predictors of the child's non-GI symptoms (mother's IBS status, child psychological symptoms, child catastrophizing, and child age). CONCLUSION: Multiple factors influence the reporting of children's gastrointestinal and non-gastrointestinal symptoms. The clustering of illness within families is best understood using a model that incorporates all these factors.

Development and validation of a clinical score for predicting risk of adenoma at screening colonoscopy.

BACKGROUND: Currently, no clinical tools use demographic and risk factor information to predict the risk of finding an adenoma in individuals undergoing colon cancer screening. Such a tool would be valuable for identifying those who would most benefit from screening colonoscopy. METHODS: We used baseline data from men and women who underwent screening colonoscopy from the randomized, multicenter National Colonoscopy Study (NCS) to develop and validate an adenoma risk model. The study, conducted at three sites in the United States (Minneapolis, MN; Seattle, WA; and Shreveport, LA) asked all participants to complete baseline questionnaires on clinical risk factors and family history. Model parameters estimated from logistic regression yielded an area under the receiver operating characteristic curve (AUROCC) used to assess prediction. RESULTS: Five hundred forty-one subjects were included in the development model, and 1,334 in the validation of the risk score. Variables in the prediction of adenoma risk for colonoscopy screening were age (likelihood ratio test for overall contribution to model, P < 0.001), male sex (P < 0.001), body mass index (P < 0.001), family history of at least one first-degree relative with colorectal cancer (P = 0.036), and smoking history (P < 0.001). The adjusted AUROCC of 0.67 [95% confidence interval (CI), 0.61-0.74] for the derivation cohort was not statistically significantly different from that in the validation cohort. The adjusted AUROCC for the entire cohort was 0.64 (95% CI, 0.60-0.67). CONCLUSION: We developed and validated a simple well-calibrated risk score. IMPACT: This tool may be useful for estimating risk of adenomas in screening eligible men and women.