Neuronal knockdown of Cullin3 as a Drosophila model of autism spectrum disorder.

Mutations in Cullin-3 (Cul3), a conserved gene encoding a ubiquitin ligase, are strongly associated with autism spectrum disorder (ASD). Here, we characterize ASD-related pathologies caused by neuron-specific Cul3 knockdown in Drosophila. We confirmed that neuronal Cul3 knockdown causes short sleep, paralleling sleep disturbances in ASD. Because sleep defects and ASD are linked to metabolic dysregulation, we tested the starvation response of neuronal Cul3 knockdown flies; they starved faster and had lower triacylglyceride levels than controls, suggesting defects in metabolic homeostasis. ASD is also characterized by increased biomarkers of oxidative stress; we found that neuronal Cul3 knockdown increased sensitivity to hyperoxia, an exogenous oxidative stress. Additional hallmarks of ASD are deficits in social interactions and learning. Using a courtship suppression assay that measures social interactions and memory of prior courtship, we found that neuronal Cul3 knockdown reduced courtship and learning compared to controls. Finally, we found that neuronal Cul3 depletion alters the anatomy of the mushroom body, a brain region required for memory and sleep. Taken together, the ASD-related phenotypes of neuronal Cul3 knockdown flies establish these flies as a genetic model to study molecular and cellular mechanisms underlying ASD pathology, including metabolic and oxidative stress dysregulation and neurodevelopment.

Key factors in the decision-making process for mastectomy alone or breast reconstruction: A qualitative analysis.

Breast cancer is the most common cancer to affect New Zealand women. Women diagnosed face several decisions regarding surgical treatment, including whether to undergo lumpectomy, mastectomy, or breast reconstruction. Reconstructive surgery adds an additional layer of complexity, with several reconstructive options, each associated with differing surgical and recovery times. Furthermore, surgical decisions are often made under time-pressure and significant diagnostic distress, therefore provision of good information to support decision-making is crucial to adequately inform women of their options. We interviewed 24 women who had undergone breast surgery within the preceding 12 months to assess the key factors leading to their decision to opt for their chosen surgical procedure. Interviews revealed that decision-making was complex and involved multiple factors. Women were ultimately confronted with assessing feminine identity versus survival. Whether opting for breast reconstruction or not, women were fearful of what surgery would involve and how their reconstructed breast or mastectomy scar might look following surgery. Shared decision-making between patient and clinician can mitigate this fear and provide women with a sense of autonomy over their health decisions. Provision of visual depictions of surgical outcomes was not routinely provided to those interviewed but was expressed as important to help women manage surgical expectations. Therefore our findings support the multi-modal presentation of diagnostic and treatment information to support decision-making. Likewise, women reported feeling unsupported in their decision not to undergo breast reconstruction, suggesting a need to develop resources to provide women with positive discussions about 'going flat'.

Novel Forms of Reluctance Among Suspected Child Sexual Abuse Victims in Adolescence.

Adolescents tend to be neglected in research examining child sexual abuse (CSA) interviews, yet are often said to be particularly reluctant. This study examined reluctance among 119 10- to 17-year-old females questioned about suspected CSA (n = 25,942 responses), utilizing a scheme identifying previously overlooked types of reluctance in commercially sexually exploited (CSE) youth. In contrast to the CSE youth in a prior study, in which 26% of responses were reluctant, only 8% of CSA victims' responses expressed reluctance. Reluctance was unrelated to age, abuse characteristics, and don't know (IDK) responding. Greater reluctance (but not IDK responding) was related to disclosure of fewer characteristics of abuse. Virtually all youth (93%) had disclosed prior to the interview, in contrast to previous studies examining reluctance among adolescent victims of internet-initiated sexual abuse and CSE. The way in which abuse is discovered may better explain reluctance than the age of the alleged victims.

Police Interviewing Behaviors and Commercially Sexually Exploited Adolescents' Reluctance.

Little is known about the relation between law enforcement interviewing behaviors and commercially sexually exploited children's (CSEC) reluctance. This study examined the relation between officers' use of maximization, (references to) expertise, minimization, and support and adolescent CSEC victims' reluctance in a small sample of police interviews (n = 2,416 question-answer pairs across ten interviews). Twenty-six percent of officers' utterances contained at least one interviewing tactic. When statements were paired with maximization, they were correlated with more reluctance than when they were not paired with an interviewing tactic. Contrary to predictions, support was also related to greater reluctance. Open-ended (recall) questions and statements were associated with greater reluctance than closed-ended (recognition) questions. The results highlight the importance of understanding the context in which interviewing strategies are employed when assessing the relation between interviewer behavior and interviewee reluctance.

Circadian autophagy drives iTRF-mediated longevity.

Time-restricted feeding (TRF) has recently gained interest as a potential anti-ageing treatment for organisms from Drosophila to humans1-5. TRF restricts food intake to specific hours of the day. Because TRF controls the timing of feeding, rather than nutrient or caloric content, TRF has been hypothesized to depend on circadian-regulated functions; the underlying molecular mechanisms of its effects remain unclear. Here, to exploit the genetic tools and well-characterized ageing markers of Drosophila, we developed an intermittent TRF (iTRF) dietary regimen that robustly extended fly lifespan and delayed the onset of ageing markers in the muscles and gut. We found that iTRF enhanced circadian-regulated transcription and that iTRF-mediated lifespan extension required both circadian regulation and autophagy, a conserved longevity pathway. Night-specific induction of autophagy was both necessary and sufficient to extend lifespan on an ad libitum diet and also prevented further iTRF-mediated lifespan extension. By contrast, day-specific induction of autophagy did not extend lifespan. Thus, these results identify circadian-regulated autophagy as a critical contributor to iTRF-mediated health benefits in Drosophila. Because both circadian regulation and autophagy are highly conserved processes in human ageing, this work highlights the possibility that behavioural or pharmaceutical interventions that stimulate circadian-regulated autophagy might provide people with similar health benefits, such as delayed ageing and lifespan extension.

Vitamin preference in Drosophila.

Many animals rely on taste to identify nutritious foods and to avoid the consumption of harmful substances. The tastes of macronutrients, as well as of non-caloric micronutrients such as sodium and calcium, contribute to the regulation of ingestive behavior1,2. Whether vitamins also affect feeding behavior through taste is less clear. Here, we show that the fly Drosophila melanogaster has a strong preference for consuming a vitamin-containing diet: both sexes show a preference for folic acid, whereas only females show a preference for riboflavin. Females show a preference with vitamin concentrations as low as ∼10 nM - at least 50,000-fold lower than the concentration needed for sucrose preference. This female vitamin preference requires inputs from external and internal taste organs, suggesting that post-ingestive signals, in the absence of gustatory input, are insufficient to actuate preferential consumption of vitamin-containing diets. Our studies demonstrate that vitamin perception is an important determinant of feeding behavior.

Neurofibromin regulates metabolic rate via neuronal mechanisms in Drosophila.

Neurofibromatosis type 1 is a chronic multisystemic genetic disorder that results from loss of function in the neurofibromin protein. Neurofibromin may regulate metabolism, though the underlying mechanisms remain largely unknown. Here we show that neurofibromin regulates metabolic homeostasis in Drosophila via a discrete neuronal circuit. Loss of neurofibromin increases metabolic rate via a Ras GAP-related domain-dependent mechanism, increases feeding homeostatically, and alters lipid stores and turnover kinetics. The increase in metabolic rate is independent of locomotor activity, and maps to a sparse subset of neurons. Stimulating these neurons increases metabolic rate, linking their dynamic activity state to metabolism over short time scales. Our results indicate that neurofibromin regulates metabolic rate via neuronal mechanisms, suggest that cellular and systemic metabolic alterations may represent a pathophysiological mechanism in neurofibromatosis type 1, and provide a platform for investigating the cellular role of neurofibromin in metabolic homeostasis.

Identifying novel forms of reluctance in commercially sexually exploited adolescents.

BACKGROUND: Research has largely overlooked expressions of reluctance in commercially sexually exploited adolescent ("CSEA") victims. This is problematic because gaining information from known victims is of the utmost importance in order to better serve the needs of current and potential future victims. OBJECTIVE: The current study proposes a novel conceptualization of reluctance based on CSEA victims' transcripts from police interviews and courtroom examinations. PARTICIPANTS AND SETTING: The study examined police interviews (n = 8 victims, 1558 utterances) and courtroom transcripts (n = 6 victims, 1961 utterances) conducted with female CSEA victims aged 15-17 years old (Mage = 16.29). The victims were associated with the same trafficker and were thus interviewed by the same group of police officers, and for those who testified, were questioned by the same lawyers in court. RESULTS: Sixteen reluctance tactics were identified, including several that have been overlooked in previous literature. The current reluctance measure identified more reluctance than previous studies' reluctance measures. Reluctance was much more common in police interviews (26.4%; p < .001) than in court (5.5%), and if victims were more reluctant in the police interviews, they were less likely to appear in court (p = .001). CONCLUSIONS: These findings have implications for future conceptualizations of reluctance, and illustrate the importance of considering the age of the victim and the circumstances under which the victim is questioned in identifying reluctance.

The Drosophila melanogaster Neprilysin Nepl15 is involved in lipid and carbohydrate storage.

The prototypical M13 peptidase, human Neprilysin, functions as a transmembrane "ectoenzyme" that cleaves neuropeptides that regulate e.g. glucose metabolism, and has been linked to type 2 diabetes. The M13 family has undergone a remarkable, and conserved, expansion in the Drosophila genus. Here, we describe the function of Drosophila melanogaster Neprilysin-like 15 (Nepl15). Nepl15 is likely to be a secreted protein, rather than a transmembrane protein. Nepl15 has changes in critical catalytic residues that are conserved across the Drosophila genus and likely renders the Nepl15 protein catalytically inactive. Nevertheless, a knockout of the Nepl15 gene reveals a reduction in triglyceride and glycogen storage, with the effects likely occurring during the larval feeding period. Conversely, flies overexpressing Nepl15 store more triglycerides and glycogen. Protein modeling suggests that Nepl15 is able to bind and sequester peptide targets of catalytically active Drosophila M13 family members, peptides that are conserved in humans and Drosophila, potentially providing a novel mechanism for regulating the activity of neuropeptides in the context of lipid and carbohydrate homeostasis.

Absolute ethanol intake predicts ethanol preference in Drosophilamelanogaster.

Factors that mediate ethanol preference in Drosophila melanogaster are not well understood. A major confound has been the use of diverse methods to estimate ethanol consumption. We measured fly consumptive ethanol preference on base diets varying in nutrients, taste and ethanol concentration. Both sexes showed an ethanol preference that was abolished on high nutrient concentration diets. Additionally, manipulating total food intake without altering the nutritive value of the base diet or the ethanol concentration was sufficient to evoke or eliminate ethanol preference. Absolute ethanol intake and food volume consumed were stronger predictors of ethanol preference than caloric intake or the dietary caloric content. Our findings suggest that the effect of the base diet on ethanol preference is largely mediated by total consumption associated with the delivery medium, which ultimately determines the level of ethanol intake. We speculate that a physiologically relevant threshold for ethanol intake is essential for preferential ethanol consumption.

PGC1α Controls Sucrose Taste Sensitization in Drosophila.

Perceived palatability of food controls caloric intake. Sweet taste is the primary means of detecting the carbohydrate content of food. Surprisingly, sweet taste sensitivity is responsive to extrinsic factors like diet, and this occurs by unknown mechanisms. Here, we describe an unbiased proteomic investigation into sweet taste sensitivity in the fruit fly. We identify a dopamine/cyclic AMP (cAMP)/CREB axis acting within sweet taste neurons that controls taste perception but is largely dispensable for acute taste transduction. This pathway modulates sweet taste perception in response to both sensory- and nutrient-restricted diets and converges on PGC1α, a critical regulator of metabolic health and lifespan. By electrophysiology, we found that enhanced sucrose taste sensitivity was the result of heightened sweet taste intensity and that PGC1α was both necessary and sufficient for this effect. Together, we provide the first molecular insight into how diet-induced taste perception is regulated within the sweet taste neuron.

Excreta Quantification (EX-Q) for Longitudinal Measurements of Food Intake in Drosophila.

Longitudinal measurements of food intake remain a challenge in Drosophila studies of nutrition and behavior. Here, we report an improved method for measuring fly food intake using dye-labeled food and excreta quantification (EX-Q). Reducing the surface area of the medium maximized excreta recovery and the accuracy in estimating total consumption. The EX-Q method is compatible with agar-based medium and makes it possible to measure consumption over an extended period and at multiple time points without sacrificing flies. Using EX-Q, we revealed nutrient- and age-specific features of Drosophila feeding behavior. Daily consumption of a chemically defined diet was relatively consistent over the first 25 days of adulthood. Omitting amino acids or vitamins from the diet reduced consumption in both sexes, whereas omitting sugars or cholesterol primarily affected female food intake. Our results demonstrate EX-Q as a simple, reliable, and nondestructive method for longitudinal studies of solid food intake in Drosophila.

Pilot study comparing the accuracy of lymphoscintigraphy sentinel lymph node localisation with axillary node dissection in women with operable breast cancer.

AIM: To evaluate the use of lymphoscintigraphy sentinel lymph node mapping with scintillation gamma probe detection and blue dye assisted sentinel lymph node biopsy in patients with invasive breast cancer. To compare the lymph nodes detected lymphosintigraphically and at surgery for invasive breast cancer and the accuracy of sentinel node prediction of axillary status. METHODS: A prospective pilot study was performed on 36 women diagnosed with invasive breast cancer requiring axillary node dissection. Lymphoscintigraphy involving peritumoral injection of 99mTechnetium antimony sulphide or rhenium sulphur colloid was performed prior to surgery. Sentinel lymph node biopsy was then performed using gamma probe and blue dye localisation. RESULTS: Sentinel lymph nodes were identified on lymphoscintigrams in 100% of cases, and sentinel nodes located surgically in 34/36 (94.4%) of patients. All women with positive axillary lymph nodes on axillary dissection were correctly identified on sentinel node biopsy. Eight patients demonstrated internal mammary (IM) node radiocolloid uptake, one returning positive IM histology in the presence of positive axillary sentinel node metastasis. CONCLUSION: A high proportion of sentinel nodes were demonstrated by lymphoscintigraphy and were subsequently removed surgically. When internal mammary nodes are identified surgical removal should be considered. In this small series sentinel lymph node status correctly predicted axillary node status in 100% of patients for whom sentinel nodes were retrieved supporting the concept of sentinel node biopsy only for women with normal sentinel lymph nodes. Evidence from randomised trials that sentinel node based management does not compromise regional control of breast cancer or survival, is awaited.

The Boston Marathon Medical Care Team: Ten Years of Experience.

In brief: Over the last decade, an elaborate medical organization has evolved to provide acute care for injured persons at the finish line of the Boston Marathon. The medical team consists of physicians, nurses, podiatrists, physical therapists, athletic trainers, and other nonmedical personnel. The team believes that the most important cause of race injuries is fluid volume depletion; therefore, severely symptomatic athletes are treated early with intravenous fluids. In addition to the medical care team, an ancillary group has been established to maintain medical records, which help to define patterns of injury, thus allowing for more precise planning of medical care. The objective of both groups is not only to improve care at the finish line but also to identify ways to prevent injuries.