Investigation of Cell-Type-Specific Effects and Synergistic Interactions Between Genes in Duplication 15q Syndrome

Duplication 15q syndrome (Dup15q) is a genetic disorder caused by duplications of the 15q11.2-q13.1 region and is characterized by developmental delay, autism spectrum disorder, and treatment resistant epilepsy. Extra copies of the E3 ubiquitin ligase UBE3A and elevated levels of UBE3A expression in neurons are thought to be the primary cause of Dup15q phenotypes. However, animal models overexpressing UBE3A in neurons have not successfully recapitulated all aspects of Dup15q syndrome, especially epilepsy. Here, we used Drosophila melanogaster (fruit flies) to investigate Dup15q syndrome. In Chapter 2 we explored whether Dube3a, the Drosophila homolog of UBE3A, is imprinted in the fly brain. In mammals, UBE3A undergoes complex imprinting and is expressed only from the maternal allele in mature neurons. Prior to this work the imprinting status of Dube3a in flies was unclear. Here, we present evidence that Dube3a is not imprinted and is biallelically expressed in the fly. Next, in Chapter 3 we examined the interaction between Dube3a and HERC2. HERC2 is also an E3 ubiquitin ligase located in the 15q11.2-q13.1 critical region and is duplicated in all Dup15q individuals. HERC2 physically interacts with and stimulates the ubiquitin ligase activity of UBE3A in vitro. We found that Drosophila HERC2 appears to stimulate the ubiquitin ligase function of Dube3a, and Dube3a and HERC2 interact synergistically to impact phenotypes associated with Dup15q syndrome in vivo. Data presented in Chapter 3 suggests that genes other than UBE3A are important in generating the Dup15q phenotypes and should not be ignored when modeling Dup15q syndrome. In Chapter 4 we investigated how non-neuronal cells, specifically glial cells, contribute to the seizure phenotype of Dup15q syndrome. We found that elevated levels of Dube3a or UBE3A in glia causes seizures, while overexpression in neurons does not. These data are consistent with mammalian models in which UBE3A elevation in neurons does not generate seizures. Furthermore, overexpression of Dube3a in glia reduced protein levels of the Na+/K+ ATPase, ATPα. ATPα down regulation in glia is both necessary and sufficient to generate seizures. In Chapter 5 we further characterized our Dup15q epilepsy model and investigated cell type specific effects of Dube3a overexpression in glia compared to neurons using whole transcriptome and whole proteome analyses. We found that elevation of Dube3a in glia caused a cell non-autonomous down regulation of synaptic proteins in neurons while simultaneously causing a cell autonomous upregulation of glutathione S-transferases (GSTs) in glial cells. Finally, we showed that the upregulation of GSTs is common to multiple different Drosophila gliopathic seizure lines, not just our Dup15q epilepsy model. GSTs play a role in drug metabolism, and elevation of these enzymes may underlie the treatment resistant nature of some epilepsies including Dup15q syndrome. The results from these studies highlight the role that glial cell dysfunction may play in generating seizures in Dup15q syndrome and could ultimately provide novel avenues for epilepsy treatments

Social Determinants of Health Associated with HBV Testing and Access to Care among Foreign-born Persons Residing in the United States: 2009 - 2012

Objectives: To describe how select Social Determinants of Health (SDH) are associated with the burden of hepatitis B virus (HBV) infection among foreign-born persons residing in the United States. Methods: Multivariate logistic regression was used to examine the Racial and Ethnic Approaches to Community Health (REACH) 2010 Risk Factor Survey data to investigate the independent relationship between SDH and HBV testing and access to care. Results: HBV infected persons with insurance were more likely to see a physician than those without. Respondents worried about money to pay rent or mortgage were more likely to report HBV infection than individuals who reported they never worry. Compared to English speakers, Spanish-speakers were less likely to report HBV infection, Vietnamese-speakers were more likely to see a physician for HBV infection, and Khmer-speakers were less likely to be tested. Conclusions: Health insurance coverage, worries about paying rent, and language of interview all differentially affect HBV testing and linkages to care among foreign–born persons. Multi-sectorial stakeholder collaborative efforts should integrate resources to provide culturally sensitive health promotion campaigns which may improve HBV related outcomes

The effect of mode and context on survey results: analysis of data from the Health Survey for England 2006 and the Boost Survey for London.

BACKGROUND: Health-related data at local level could be provided by supplementing national health surveys with local boosts. Self-completion surveys are less costly than interviews, enabling larger samples to be achieved for a given cost. However, even when the same questions are asked with the same wording, responses to survey questions may vary by mode of data collection. These measurement differences need to be investigated further. METHODS: The Health Survey for England in London ('Core') and a London Boost survey ('Boost') used identical sampling strategies but different modes of data collection. Some data were collected by face-to-face interview in the Core and by self-completion in the Boost; other data were collected by self-completion questionnaire in both, but the context differed. Results were compared by mode of data collection using two approaches. The first examined differences in results that remained after adjusting the samples for differences in response. The second compared results after using propensity score matching to reduce any differences in sample composition. RESULTS: There were no significant differences between the two samples for prevalence of some variables including long-term illness, limiting long-term illness, current rates of smoking, whether participants drank alcohol, and how often they usually drank. However, there were a number of differences, some quite large, between some key measures including: general health, GHQ12 score, portions of fruit and vegetables consumed, levels of physical activity, and, to a lesser extent, smoking consumption, the number of alcohol units reported consumed on the heaviest day of drinking in the last week and perceived social support (among women only). CONCLUSION: Survey mode and context can both affect the responses given. The effect is largest for complex question modules but was also seen for identical self-completion questions. Some data collected by interview and self-completion can be safely combined

Flame experiments at the Advanced Light Source: New insights into soot formation processes

Hansen N, Skeen SA, Michelsen HA, Wilson KR, Kohse-Höinghaus K. Flame experiments at the Advanced Light Source: New insights into soot formation processes. JOURNAL OF VISUALIZED EXPERIMENTS. 2014;87(87):E51369

The effect of survey method on survey participation: Analysis of data from the Health Survey for England 2006 and the Boost Survey for London

BACKGROUND: There is a need for local level health data for local government and health bodies, for health surveillance and planning and monitoring of policies and interventions. The Health Survey for England (HSE) is a nationally-representative survey of the English population living in private households, but sub-national analyses can be performed only at a regional level because of sample size. A boost of the HSE was commissioned to address the need for local level data in London but a different mode of data collection was used to maximise participant numbers for a given cost. This study examines the effects on survey and item response of the different survey modes. METHODS: Household and individual level data are collected in HSE primarily through interviews plus individual measures through a nurse visit. For the London Boost, brief household level data were collected through interviews and individual level data through a longer self-completion questionnaire left by the interviewer and collected later. Sampling and recruitment methods were identical, and both surveys were conducted by the same organisation. There was no nurse visit in the London Boost. Data were analysed to assess the effects of differential response rates, item non-response, and characteristics of respondents. RESULTS: Household response rates were higher in the 'Boost' (61%) than 'Core' (HSE participants in London) sample (58%), but the individual response rate was considerably higher in the Core (85%) than Boost (65%). There were few differences in participant characteristics between the Core and Boost samples, with the exception of ethnicity and educational qualifications. Item non-response was similar for both samples, except for educational level. Differences in ethnicity were corrected with non-response weights, but differences in educational qualifications persisted after non-response weights were applied. When item non-response was added to those reporting no qualification, participants' educational levels were similar in the two samples. CONCLUSION: Although household response rates were similar, individual response rates were lower using the London Boost method. This may be due to features of London that are particularly associated with lower response rates for the self-completion element of the Boost method, such as the multi-lingual population. Nevertheless, statistical adjustments can overcome most of the demographic differences for analysis. Care must be taken when designing self-completion questionnaires to minimise item non-response

Safety analyses from the phase 3 ASCENT trial of sacituzumab govitecan in metastatic triple-negative breast cancer

Breast cancer; Drug safetyCàncer de mama; Seguretat dels medicamentsCáncer de mama; Seguridad de los medicamentosSacituzumab govitecan (SG) is an anti-Trop-2 antibody-drug conjugate with an SN-38 payload. In the ASCENT study, patients with metastatic triple-negative breast cancer (mTNBC) relapsed/refractory to ≥2 prior chemotherapy regimens (≥1 in the metastatic setting), received SG or single-agent treatment of physician’s choice (eribulin, vinorelbine, capecitabine, or gemcitabine). This ASCENT safety analysis includes the impact of age and UGT1A1 polymorphisms, which hinder SN-38 detoxification. SG demonstrated a manageable safety profile in patients with mTNBC, including those ≥65 years; neutropenia/diarrhea are key adverse events (AE). Patients with UGT1A1 *28/*28 genotype versus those with 1/*28 and *1/*1 genotypes had higher rates of grade ≥3 SG-related neutropenia (59% vs 47% and 53%), febrile neutropenia (18% vs 5% and 3%), anemia (15% vs 6% and 4%), and diarrhea (15% vs 9% and 10%), respectively. Individuals with UGT1A1 *28/*28 genotype should be monitored closely; active monitoring and routine AE management allow optimal therapeutic exposure of SG.This study was sponsored by Immunomedics, Inc., a subsidiary of Gilead Sciences, Inc. We thank the ASCENT patients, their caregivers, study investigators, and team members. We thank William A. Wegener, MD, PhD, Robert M. Sharkey, PhD, and Pius Maliakal, PhD, former employees of Immunomedics, for their contributions to the development of the ASCENT protocol and the clinical development of sacituzumab govitecan. Medical writing and editorial assistance were provided by Robert Rydzewski, MS, CMPP, and Shala Thomas, PhD, CMPP, of Team 9 Science, and funded by Immunomedics, Inc., a subsidiary of Gilead Sciences, Inc

Sequential mechanisms underlying concentration invariance in biological olfaction

Concentration invariance—the capacity to recognize a given odorant (analyte) across a range of concentrations—is an unusually difficult problem in the olfactory modality. Nevertheless, humans and other animals are able to recognize known odors across substantial concentration ranges, and this concentration invariance is a highly desirable property for artificial systems as well. Several properties of olfactory systems have been proposed to contribute to concentration invariance, but none of these alone can plausibly achieve full concentration invariance. We here propose that the mammalian olfactory system uses at least six computational mechanisms in series to reduce the concentration-dependent variance in odor representations to a level at which different concentrations of odors evoke reasonably similar representations, while preserving variance arising from differences in odor quality. We suggest that the residual variance then is treated like any other source of stimulus variance, and categorized appropriately into “odors” via perceptual learning. We further show that naïve mice respond to different concentrations of an odorant just as if they were differences in quality, suggesting that, prior to odor categorization, the learning-independent compensatory mechanisms are limited in their capacity to achieve concentration invariance

Development and validation of a short form psychometric tool assessing the caregiving Challenge of Living with Cystic Fibrosis (CLCF-SF) in a child.

Caring for a child with cystic fibrosis (CF) is a rigorous daily commitment for caregivers and treatment burden is a major concern. We aimed to develop and validate a short form version of a 46-item tool assessing the Challenge of Living with Cystic Fibrosis (CLCF) for clinical or research use. A novel genetic algorithm based on 'evolving' a subset of items from a pre-specified set of criteria, was applied to optimise the tool, using data from 135 families. Internal reliability and validity were assessed; the latter compared scores to validated tests of parental well-being, markers of treatment burden, and disease severity. The 15-item CLCF-SF demonstrated very good internal consistency [Cronbach's alpha 0.82 (95%CI 0.78-0.87)]. Scores for convergent validity correlated with the Beck Depression Inventory (Rho = 0.48), State Trait Anxiety Inventory (STAI-State, Rho = 0.41; STAI-Trait, Rho = 0.43), Cystic Fibrosis Questionnaire-Revised, lung function (Rho = -0.37), caregiver treatment management (  = 0.48) and child treatment management (  = 0.45), and discriminated between unwell and well children with CF (Mean Difference 5.5, 95%CI 2.5-8.5,  < 0.001), and recent or no hospital admission (MD 3.6, 95%CI 0.25-6.95,  = 0.039). The CLCF-SF provides a robust 15-item tool for assessing the challenge of living with a child with CF