Adaptive DNA amplification of synthetic gene circuit opens a way to overcome cancer chemoresistance.

Drug resistance continues to impede the success of cancer treatments, creating a need for experimental model systems that are broad, yet simple, to allow the identification of mechanisms and novel countermeasures applicable to many cancer types. To address these needs, we investigated a set of engineered mammalian cell lines with synthetic gene circuits integrated into their genome that evolved resistance to Puromycin. We identified DNA amplification as the mechanism underlying drug resistance in 4 out of 6 replicate populations. Triplex-forming oligonucleotide (TFO) treatment combined with Puromycin could efficiently suppress the growth of cell populations with DNA amplification. Similar observations in human cancer cell lines suggest that TFOs could be broadly applicable to mitigate drug resistance, one of the major difficulties in treating cancer.

Hexose translocation mediated by SlSWEET5b is required for pollen maturation in Solanum lycopersicum.

Pollen fertility is critical for successful fertilization and, accordingly, for crop yield. While sugar unloading affects the growth and development of all types of sink organs, the molecular nature of sugar import to tomato (Solanum lycopersicum) pollen is poorly understood. However, sugar will eventually be exported transporters (SWEETs) have been proposed to be involved in pollen development. Here, reverse transcription-quantitative polymerase chain reaction (PCR) revealed that SlSWEET5b was markedly expressed in flowers when compared to the remaining tomato SlSWEETs, particularly in the stamens of maturing flower buds undergoing mitosis. Distinct accumulation of SlSWEET5b-ß-glucuronidase activities was present in mature flower buds, especially in anther vascular and inner cells, symplasmic isolated microspores (pollen grains), and styles. The demonstration that SlSWEET5b-GFP fusion proteins are located in the plasma membrane supports the idea that the SlSWEET5b carrier functions in apoplasmic sugar translocation during pollen maturation. This is consistent with data from yeast complementation experiments and radiotracer uptake, showing that SlSWEET5b operates as a low-affinity hexose-specific passive facilitator, with a Km of ∼36 mM. Most importantly, RNAi-mediated suppression of SlSWEET5b expression resulted in shrunken nucleus-less pollen cells, impaired germination, and low seed yield. Moreover, stamens from SlSWEET5b-silenced tomato mutants showed significantly lower amounts of sucrose (Suc) and increased invertase activity, indicating reduced carbon supply and perturbed Suc homeostasis in these tissues. Taken together, our findings reveal the essential role of SlSWEET5b in mediating apoplasmic hexose import into phloem unloading cells and into developing pollen cells to support pollen mitosis and maturation in tomato flowers.

Using optogenetics to link myosin patterns to contractile cell behaviors during convergent extension.

Distinct patterns of actomyosin contractility are often associated with particular epithelial tissue shape changes during development. For example, a planar-polarized pattern of myosin II localization regulated by Rho1 signaling during Drosophila body axis elongation is thought to drive cell behaviors that contribute to convergent extension. However, it is not well understood how specific aspects of a myosin pattern influence the multiple cell behaviors, including cell intercalation, cell shape changes, and apical cell area fluctuations, that simultaneously occur during morphogenesis. Here, we developed two optogenetic tools, optoGEF and optoGAP, to activate or deactivate Rho1 signaling, respectively. We used these tools to manipulate myosin patterns at the apical side of the germband epithelium during Drosophila axis elongation and analyzed the effects on contractile cell behaviors. We show that uniform activation or inactivation of Rho1 signaling across the apical surface of the germband is sufficient to disrupt the planar-polarized pattern of myosin at cell junctions on the timescale of 3-5 min, leading to distinct changes in junctional and medial myosin patterns in optoGEF and optoGAP embryos. These two perturbations to Rho1 activity both disrupt axis elongation and cell intercalation but have distinct effects on cell area fluctuations and cell packings that are linked with changes in the medial and junctional myosin pools. These studies demonstrate that acute optogenetic perturbations to Rho1 activity are sufficient to rapidly override the endogenous planar-polarized myosin pattern in the germband during axis elongation. Moreover, our results reveal that the levels of Rho1 activity and the balance between medial and junctional myosin play key roles not only in organizing the cell rearrangements that are known to directly contribute to axis elongation but also in regulating cell area fluctuations and cell packings, which have been proposed to be important factors influencing the mechanics of tissue deformation and flow.

Associations of diet, physical activity and polycystic ovary syndrome in the Coronary Artery Risk Development in Young Adults Women's Study.

BACKGROUND: Current evidence supports the adoption of healthy diet and physical activity (PA) behaviors in patients with polycystic ovary syndrome (PCOS), given the positive effects of those behaviors on physical well-being. An improved understanding of the associations between diet and PA with PCOS is needed to ascertain whether tailored dietary and PA recommendations are needed for this population. Thus, we investigated the associations of diet and PA with PCOS and its isolated features. METHODS: Cross-sectional study. Of the 748 women who were included in this study from the Coronary Artery Risk Development in Young Adults (CARDIA) Women's Study, 40 were classified as having PCOS, 104 had isolated hyperandrogenism (HA) and 75 had isolated oligomenorrhea (OA). Dietary intake was measured using the CARDIA diet history questionnaire and diet quality was scored using the Alternative Healthy Eating Index 2010; a higher score indicated a better quality diet. Self-reported PA was measured using a validated interviewer-administered questionnaire. Polytomous logistic regression analyses examined the associations between diet and PA with PCOS, HA, and OA status (outcomes), adjusting for age, race, total energy intake, education, and/or body mass index. The threshold for statistical significance was set at p < 0.05. RESULTS: Mean age of the participants was 25.4 years (SD 3.6) and 46.8% of participants were Black women. There was little to no association of total energy intake, nutrients, diet quality, and PA with PCOS, HA or OA status. CONCLUSION: Energy intake, nutrient composition, diet quality, and PA were not associated with PCOS, supporting recent PCOS guidelines of using national recommendations for the general population to encourage health-promoting behaviors among women with PCOS. However, longitudinal studies evaluating changes in diet and physical activity in relation to the development and/or the progression of PCOS are needed to establish a causal association.

Association of number of bites and eating speed with energy intake: Wearable technology results under free-living conditions.

Personalized weight management strategies are gaining interest. However, knowledge is limited regarding eating habits and association with energy intake, and current technologies limit assessment in free-living situations. We assessed associations between eating behavior and time of day with energy intake using a wearable camera under free-living conditions and explored if obesity modifies the associations. Sixteen participants (50% with obesity) recorded free-living eating behaviors using a wearable fish-eye camera for 14 days. Videos were viewed by trained annotators who confirmed number of bites, eating speed, and time of day for each eating episode. Energy intake was determined by a trained dietitian performing 24-h diet recalls. Greater number of bites, reduced eating speed, and increased BMI significantly predicted higher energy intake among all participants (P < 0.05, each). There were no significant interactions between obesity and number of bites, eating speed, or time of day (p > 0.05). Greater number of bites and reduced eating speed were significantly associated with higher energy intake in participants without obesity. Results show that under free-living conditions, more bites and slower eating speed predicted higher energy intake when examining consumption of foods with beverages. Obesity did not modify these associations. Findings highlight how eating behaviors can impact energy balance and can inform weight management interventions using wearable technology.

FINO2 initiates ferroptosis through GPX4 inactivation and iron oxidation.

Ferroptosis is a non-apoptotic form of regulated cell death caused by the failure of the glutathione-dependent lipid-peroxide-scavenging network. FINO2 is an endoperoxide-containing 1,2-dioxolane that can initiate ferroptosis selectively in engineered cancer cells. We investigated the mechanism and structural features necessary for ferroptosis initiation by FINO2. We found that FINO2 requires both an endoperoxide moiety and a nearby hydroxyl head group to initiate ferroptosis. In contrast to previously described ferroptosis inducers, FINO2 does not inhibit system xc- or directly target the reducing enzyme GPX4, as do erastin and RSL3, respectively, nor does it deplete GPX4 protein, as does FIN56. Instead, FINO2 both indirectly inhibits GPX4 enzymatic function and directly oxidizes iron, ultimately causing widespread lipid peroxidation. These findings suggest that endoperoxides such as FINO2 can initiate a multipronged mechanism of ferroptosis.

Derivation of a clinical decision instrument to identify patients with status epilepticus who require emergent brain CT.

BACKGROUND: Studies have shown the value of CT brain imaging in adults with first-time seizures, but there are no recommendations regarding emergent brain CTs in persons with an established seizure disorders. Our study aimed to derive a clinical decision instrument (CDI) to determine which patients with status epilepticus (SE) require emergent brain imaging. METHODS: This was a retrospective chart review of patients who presented to our emergency department with SE between 2010 and 2018. Patients with first-time seizures were excluded. A priori, we defined high risk criteria for emergent imaging as well as positive findings on brain CT. High risk criteria included known malignancy, trauma, and immunosuppression. Positive CT scans included findings such as intracranial hemorrhage (ICH) and mass. RESULTS: We identified 214 patients who met inclusion criteria Of the 181 patients without high risk criteria, 3% had positive CT scans. Of the 33 patients with high risk criteria, 10% had positive CT scans. The sensitivity, specificity, PPV, and NPV for our initial CDI were 38%, 85%, 9%, and 97%. Adding the criterion of prior ICH would have lowered our miss rate to 0.6%. Modifying our CDI to 1) History of ICH, 2) Malignancy, 3) Immunosuppression, and 4) Trauma would result in a CDI with sensitivity, specificity, PPV, and NPV of 87.5%, 87.4%, 21.2%, and 99.5%. CONCLUSIONS: By using four criteria to identify high risk patients, we can defer CT scanning in the vast majority of patients with SE and known seizure disorders. This CDI should be prospectively validated before adoption.

Interrogation of Eukaryotic Stop Codon Readthrough Signals by in Vitro RNA Selection.

RNA signals located downstream of stop codons in eukaryotic mRNAs can stimulate high levels of translational readthrough by the ribosome, thereby giving rise to functionally distinct C-terminally extended protein products. Although many readthrough events have been previously discovered in Nature, a broader description of the stimulatory RNA signals would help to identify new reprogramming events in eukaryotic genes and provide insights into the molecular mechanisms of readthrough. Here, we explore the RNA reprogramming landscape by performing in vitro translation selections to enrich RNA readthrough signals de novo from a starting randomized library comprising >1013 unique sequence variants. Selection products were characterized using high-throughput sequencing, from which we identified primary sequence and secondary structure readthrough features. The activities of readthrough signals, including three novel sequence motifs, were confirmed in cellular reporter assays. Then, we used machine learning and our HTS data to predict readthrough activity from human 3'-untranslated region sequences. This led to the discovery of >1.5% readthrough in four human genes (CDKN2B, LEPROTL1, PVRL3, and SFTA2). Together, our results provide valuable insights into RNA-mediated translation reprogramming, offer tools for readthrough discovery in eukaryotic genes, and present new opportunities to explore the biological consequences of stop codon readthrough in humans.

Reprogramming eukaryotic translation with ligand-responsive synthetic RNA switches.

Protein synthesis in eukaryotes is regulated by diverse reprogramming mechanisms that expand the coding capacity of individual genes. Here, we exploit one such mechanism, termed -1 programmed ribosomal frameshifting (-1 PRF), to engineer ligand-responsive RNA switches that regulate protein expression. First, efficient -1 PRF stimulatory RNA elements were discovered by in vitro selection; then, ligand-responsive switches were constructed by coupling -1 PRF stimulatory elements to RNA aptamers using rational design and directed evolution in Saccharomyces cerevisiae. We demonstrate that -1 PRF switches tightly control the relative stoichiometry of two distinct protein outputs from a single mRNA, exhibiting consistent ligand response across whole populations of cells. Furthermore, -1 PRF switches were applied to build single-mRNA logic gates and an apoptosis module in yeast. Together, these results showcase the potential for harnessing translation-reprogramming mechanisms for synthetic biology, and they establish -1 PRF switches as powerful RNA tools for controlling protein synthesis in eukaryotes.

A novel role for ceramide synthase 6 in mouse and human alcoholic steatosis.

Perilipin 2 (PLIN2) is a lipid-droplet protein that is up-regulated in alcoholic steatosis and associated with hepatic accumulation of ceramides, bioactive lipids implicated in alcoholic liver disease pathogenesis. The specific role of ceramide synthetic enzymes in the regulation of PLIN2 and promotion of hepatocellular lipid accumulation is not well understood. We examined the effects of pharmacologic ceramide synthesis inhibition on hepatic PLIN2 expression, steatosis, and glucose and lipid homeostasis in mice with alcoholic steatosis and in ethanol-incubated human hepatoma VL17A cells. In cells, pharmacologic inhibition of ceramide synthase reduced lipid accumulation by reducing PLIN2 RNA stability. The subtype ceramide synthase (CerS)6 was specifically up-regulated in experimental alcoholic steatosis in vivo and in vitro and was up-regulated in zone 3 hepatocytes in human alcoholic steatosis. In vivo ceramide reduction by inhibition of de novo ceramide synthesis reduced PLIN2 and hepatic steatosis in alcohol-fed mice, but only de novo synthesis inhibition, not sphingomyelin hydrolysis, improved glucose tolerance and dyslipidemia. These findings implicate CerS6 as a novel regulator of PLIN2 and suggest that ceramide synthetic enzymes may promote the earliest stage of alcoholic liver disease, alcoholic steatosis.-Williams, B., Correnti, J., Oranu, A., Lin, A., Scott, V., Annoh, M., Beck, J., Furth, E., Mitchell, V., Senkal, C. E., Obeid, L., Carr, R. M. A novel role for ceramide synthase 6 in mouse and human alcoholic steatosis.

Counting Bites With Bits: Expert Workshop Addressing Calorie and Macronutrient Intake Monitoring.

BACKGROUND: Conventional diet assessment approaches such as the 24-hour self-reported recall are burdensome, suffer from recall bias, and are inaccurate in estimating energy intake. Wearable sensor technology, coupled with advanced algorithms, is increasingly showing promise in its ability to capture behaviors that provide useful information for estimating calorie and macronutrient intake. OBJECTIVE: This paper aimed to summarize current technological approaches to monitoring energy intake on the basis of expert opinion from a workshop panel and to make recommendations to advance technology and algorithms to improve estimation of energy expenditure. METHODS: A 1-day invitational workshop sponsored by the National Science Foundation was held at Northwestern University. A total of 30 participants, including population health researchers, engineers, and intervention developers, from 6 universities and the National Institutes of Health participated in a panel discussing the state of evidence with regard to monitoring calorie intake and eating behaviors. RESULTS: Calorie monitoring using technological approaches can be characterized into 3 domains: (1) image-based sensing (eg, wearable and smartphone-based cameras combined with machine learning algorithms); (2) eating action unit (EAU) sensors (eg, to measure feeding gesture and chewing rate); and (3) biochemical measures (eg, serum and plasma metabolite concentrations). We discussed how each domain functions, provided examples of promising solutions, and highlighted potential challenges and opportunities in each domain. Image-based sensor research requires improved ground truth (context and known information about the foods), accurate food image segmentation and recognition algorithms, and reliable methods of estimating portion size. EAU-based domain research is limited by the understanding of when their systems (device and inference algorithm) succeed and fail, need for privacy-protecting methods of capturing ground truth, and uncertainty in food categorization. Although an exciting novel technology, the challenges of biochemical sensing range from a lack of adaptability to environmental effects (eg, temperature change) and mechanical impact, instability of wearable sensor performance over time, and single-use design. CONCLUSIONS: Conventional approaches to calorie monitoring rely predominantly on self-reports. These approaches can gain contextual information from image-based and EAU-based domains that can map automatically captured food images to a food database and detect proxies that correlate with food volume and caloric intake. Although the continued development of advanced machine learning techniques will advance the accuracy of such wearables, biochemical sensing provides an electrochemical analysis of sweat using soft bioelectronics on human skin, enabling noninvasive measures of chemical compounds that provide insight into the digestive and endocrine systems. Future computing-based researchers should focus on reducing the burden of wearable sensors, aligning data across multiple devices, automating methods of data annotation, increasing rigor in studying system acceptability, increasing battery lifetime, and rigorously testing validity of the measure. Such research requires moving promising technological solutions from the controlled laboratory setting to the field.

Health-related knowledge, beliefs and self-efficacy in women with polycystic ovary syndrome.

STUDY QUESTION: Do health-related knowledge, beliefs and self-efficacy differ between women with and without polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Women with PCOS felt at greater risk for adverse health outcomes, yet believed a healthy lifestyle was less beneficial to prevent weight gain relative to a comparison group. WHAT IS KNOWN ALREADY: Diet and physical activity are often used to treat PCOS, but there are high attrition rates and less engagement in self-help methods. It is unclear whether there are unique psychosocial considerations in PCOS that should be incorporated into these interventions. STUDY DESIGN, SIZE, DURATION: This cross-sectional study enrolled 475 women with (N = 255) and without PCOS (N = 220). PARTICIPANTS/MATERIALS, SETTING, METHODS: Female participants were recruited through paper and web-based advertisements across the US (mean age: 28.1 ± 5.4 years). Participants were either diagnosed with PCOS by a healthcare professional (PCOS group) or had self-reported regular menstrual cycles (comparison group). A reliable and valid online instrument about health-related knowledge, beliefs and self-efficacy was administered to these participants. MAIN RESULTS AND THE ROLE OF CHANCE: Most women with PCOS had a basic understanding of nutrition (96%), but had misconceptions about diagnostic criteria for PCOS (≥86%). PCOS was associated with greater perceived susceptibility for disease and weight gain and poorer perceived control over these health outcomes (all P < 0.05), in relation to the comparison group. Women with PCOS also perceived fewer benefits of healthy behaviors on weight gain (P = 0.03) with less than half of the PCOS group attempting to follow government diet recommendations (47%). There were no differences in the self-efficacy of dietary behaviors between groups. LIMITATIONS, REASONS FOR CAUTION: It is likely that participant self-selection occurred due to the nature of recruitment in this study and results may have limited generalizability since most participants identified as Caucasian. Additionally, it is unclear whether some results may be clinically meaningful due to small effect sizes. WIDER IMPLICATIONS OF THE FINDINGS: These findings support that behavioral interventions should incorporate the unique psychosocial considerations associated with PCOS to encourage patient participation in lifestyle interventions. STUDY FUNDING/COMPETING INTEREST(S): This manuscript was partially supported by Cornell University Human Ecology Alumni Association and College of Agriculture and Life Sciences Alumni Association. The authors have no competing interests. TRIAL REGISTRATION NUMBER: NCT01859663.

Characterization of the peripheral neuropathy associated with brentuximab vedotin treatment of Mycosis Fungoides and Sézary Syndrome.

Chemotherapy-induced peripheral neuropathy (CIPN) is common, frequently limits chemotherapy dosing, and negatively impacts quality of life. The National Cancer Institute Common Toxicity Criteria for Adverse Events (CTCAE), version 4.0, and the Total Neuropathy Score clinical version (TNSc) are both validated scores to quantify peripheral neuropathy (PN), with the TNSc being more sensitive to clinical changes. Mycosis fungoides and Sézary syndrome (MF/SS) are characterized by a chronic course, where current therapies are generally non-curative and treatment toxicities have the potential for significant lasting effects. Brentuximab vedotin (BV) is an antibody-drug-conjugate composed of an anti-CD30 monoclonal antibody linked to the microtubule-disrupting agent, monomethyl auristatin E, with a known associated CIPN. In our phase II clinical trial of BV in MF/SS, 25 (69%) of 36 patients developed PN, with 18 (50%) developing Clinically Significant PN, CTCAE v4.0 grade 2 or higher. The median time to grade 2 PN was 15 weeks (range 0.4-48) after the initial dose. By Kaplan-Meier calculation, the median time to improvement from Clinically Significant PN was 30 weeks from the last BV dose. Seventy-four percent had improvement by 24 months. We found that TNSc scores significantly correlated with CTCAE grade, with Spearman correlation coefficient 0.68 (p < 0.001). By logistic regression, for each 100 mg increase in BV total dose, the likelihood of developing Clinically Significant PN increased by 23% (95% CI 4-46%). Improved monitoring of CIPN associated with BV is of paramount importance in the MF/SS population.

Case report: Clinical and pathological findings in a canine patient with intervertebral disk extrusion resembling progressive myelomalacia.

A 4-year-old female spayed dog presented to the emergency department for non-ambulatory tetraparesis, which progressed to tetraplegia. Computed tomography (CT) confirmed cervical intervertebral disk extrusion at C5-6 extending to C6-7, and an emergency ventral slot was performed. After the procedure, the patient was placed on mechanical ventilation due to respiratory failure. Repeat assessment upon weaning her ventilatory support suggested the patient's neurological status had declined. Based on her deterioration and suspicion of progressive myelomalacia on magnetic resonance imaging (MRI), she was euthanized. Post-mortem histopathology of the spinal cord supported the presence of progressive myelomalacia. To the author's knowledge, this is the first case report describing a progressive myelomalacia in a canine patient with cervical intervertebral disk extrusion.

Rationale and design of the SenseWhy project: A passive sensing and ecological momentary assessment study on characteristics of overeating episodes.

Objectives: Overeating interventions and research often focus on single determinants and use subjective or nonpersonalized measures. We aim to (1) identify automatically detectable features that predict overeating and (2) build clusters of eating episodes that identify theoretically meaningful and clinically known problematic overeating behaviors (e.g., stress eating), as well as new phenotypes based on social and psychological features. Method: Up to 60 adults with obesity in the Chicagoland area will be recruited for a 14-day free-living observational study. Participants will complete ecological momentary assessments and wear 3 sensors designed to capture features of overeating episodes (e.g., chews) that can be visually confirmed. Participants will also complete daily dietitian-administered 24-hour recalls of all food and beverages consumed. Analysis: Overeating is defined as caloric consumption exceeding 1 standard deviation of an individual's mean consumption per eating episode. To identify features that predict overeating, we will apply 2 complementary machine learning methods: correlation-based feature selection and wrapper-based feature selection. We will then generate clusters of overeating types and assess how they align with clinically meaningful overeating phenotypes. Conclusions: This study will be the first to assess characteristics of eating episodes in situ over a multiweek period with visual confirmation of eating behaviors. An additional strength of this study is the assessment of predictors of problematic eating during periods when individuals are not on a structured diet and/or engaged in a weight loss intervention. Our assessment of overeating episodes in real-world settings is likely to yield new insights regarding determinants of overeating that may translate into novel interventions.

Notch1 cortical signaling regulates epithelial architecture and cell-cell adhesion.

Notch receptors control tissue morphogenic processes that involve coordinated changes in cell architecture and gene expression, but how a single receptor can produce these diverse biological outputs is unclear. Here, we employ a 3D model of a human ductal epithelium to reveal tissue morphogenic defects result from loss of Notch1, but not Notch1 transcriptional signaling. Instead, defects in duct morphogenesis are driven by dysregulated epithelial cell architecture and mitogenic signaling which result from the loss of a transcription-independent, Notch1 cortical signaling mechanism that ultimately functions to stabilize adherens junctions and cortical actin. We identify that Notch1 localization and cortical signaling are tied to apical-basal cell restructuring and discover that a Notch1-FAM83H interaction underlies control of epithelial adherens junctions and cortical actin. Together, these results offer new insights into Notch1 signaling and regulation and advance a paradigm in which transcriptional and cell adhesive programs might be coordinated by a single receptor.

Overnight Melatonin Concentration and Sleep Quality Are Associated with the Clinical Features of Polycystic Ovary Syndrome.

Circulating melatonin is elevated in women with polycystic ovary syndrome (PCOS); whether circadian disruptions coincide with sleep disturbances in women with PCOS or their symptom severity is unclear. The objective of this observational pilot study was to determine whether altered patterns of melatonin excretion are associated with reduced sleep quality in women with versus without PCOS. Participants underwent a clinical assessment, transvaginal ultrasound, and reproductive hormone testing. Morning and evening urine samples were assayed for urinary 6-sulfatoxymelatonin (MEL) as a proxy for melatonin production. The night (morning MEL)-to-day (evening MEL) ratio, or N:D ratio, was determined to approximate the rhythm of MEL production. Sleep quality and duration were assessed using the Pittsburgh Sleep Quality Index (PSQI) and wrist actigraphy. No differences were detected in overnight MEL, daytime MEL, or the N:D ratio in participants with PCOS versus controls. The PCOS group experienced reduced weekend sleep efficiency vs. controls (81% vs. 88% p < 0.05). The number of follicles per ovary (FNPO) was positively associated with overnight MEL (r = 0.359, p < 0.05). Weekend sleep time and overnight MEL concentrations were dependent on PCOS status. Therefore, diagnostic features of PCOS were associated with MEL production and sleep disturbances, suggesting that women with a more severe clinical presentation of PCOS may be more likely to experience altered MEL production or sleep disturbances.

Resilience and smoking: the implications for general practitioners and other primary healthcare practitioners.

BACKGROUND: Smoking cessation counselling is a key component of medical treatment and health promotion activities performed by general practitioners (GPs); however, GPs are often left wondering why their patients continue to smoke in spite of being given information about the damaging health effects and medical treatments. The concept of resilience to smoking is an emerging idea that offers an innovative perspective to smoking cessation. AIMS: To understand why some people continue to smoke in spite of well-known adverse health effects, what and how resilience factors impact on people's smoking, and the role and limitations of the GP in fostering resilience to smoking. METHOD: A qualitative study of 22 oral-history interviews was conducted in Adelaide, South Australia. Interviews were audio-recorded, transcribed and analysed for emergent themes. RESULTS: The main themes of most relevance to GPs are the resilience to health messages, resilience factors associated with smoking abstinence and the common pathways that lead to successful smoking cessation. DISCUSSION: Understanding smoking and resilience can assist the GP to provide more effective and supportive smoking cessation assistance. The GP may assist in the process by fostering the adoption of resilience factors, much of which is already part of routine GP work but may not yet be considered part of a holistic smoking cessation strategy. Through this holistic approach, smoking cessation is likely to be just one of many physical and social benefits, and avoids victim blaming. Broad system change to increase the levels of resilience within individuals and communities may then mean that smokers can stop more easily with brief interventions. Such changes are beyond the limits of a single GP, but provide opportunities to lobby government for future public health programmes aimed at promoting both the internal traits and external resources that are required for resilience building.

Comparative Validity of Mostly Unprocessed and Minimally Processed Food Items Differs Among Popular Commercial Nutrition Apps Compared with a Research Food Database.

BACKGROUND: Commercial nutrition apps are increasingly used to evaluate diet. Evaluating the comparative validity of nutrient data from commercial nutrition app databases is important to determine the merits of using these apps for dietary assessment. OBJECTIVE: Nutrient data from four commercial nutrition apps were compared with a research-based food database, Nutrition Data System for Research (NDSR) (version 2017). DESIGN: Comparative validation study. PARTICIPANTS/SETTING: An investigator identified the 50 most frequently consumed foods (22% of total reported foods) from a weight-loss study in Chicago, IL, during 2017. Nutrient data were compared between four commercial databases with NDSR. MAIN OUTCOME MEASURES: Comparative validity of energy, macronutrients, and other nutrient data (ie, total sugars, fiber, saturated fat, cholesterol, calcium, and sodium). STATISTICAL ANALYSES PERFORMED: Intraclass correlation coefficients (ICCs) evaluated agreement between commercial databases with the NDSR for foods that were primarily un- and minimally processed and by the three most frequently consumed food groups. Bland-Altman plots determined degree of bias for calories between commercial databases and NDSR. RESULTS: This study observed excellent agreement between NDSR and CalorieKing (ICC range = 0.90 to 1.00). Compared with NDSR, agreement for Lose It! and MyFitnessPal ranged from good to excellent (ICC range = 0.89 to 1.00), with the exception of fiber in MyFitnessPal (ICC = 0.67). Fitbit showed the widest variability with NDSR (ICC range = 0.52 to 0.98). When evaluating by food group, Fitbit had poor agreement for all food groups, with the lowest agreement observed for fiber within the vegetable group (ICC = 0.16). Bland-Altman plots confirmed ICC energy results but also found that MyFitnessPal had the poorest agreement to NDSR (mean 8.35 [SD 133.31] kcal) for all food items. CONCLUSIONS: Degree of agreement varied by commercial nutrition app. CalorieKing and Lose It! had mostly excellent agreement with NDSR for all investigated nutrients. Fitbit showed the widest variability in agreement with NDSR for most nutrients, which may reflect how well the app can accurately capture diet.

Small-molecule allosteric inhibitors of GPX4.

Encouraged by the dependence of drug-resistant, metastatic cancers on GPX4, we examined biophysical mechanisms of GPX4 inhibition, which revealed an unexpected allosteric site. We found that this site was involved in native regeneration of GPX4 under low glutathione conditions. Covalent binding of inhibitors to this allosteric site caused a conformational change, inhibition of activity, and subsequent cellular GPX4 protein degradation. To verify this site in an unbiased manner, we screened a library of compounds and identified and validated that an additional compound can covalently bind in this allosteric site, inhibiting and degrading GPX4. We determined co-crystal structures of six different inhibitors bound in this site. We have thus identified an allosteric mechanism for small molecules targeting aggressive cancers dependent on GPX4.