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1.
J Biol Chem ; : 107423, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38815864

RESUMO

Recent research has identified the mechanistic Target of Rapamycin Complex 2 (mTORC2) as a conserved direct effector of Ras proteins. While previous studies suggested the involvement of the Switch I (SWI) effector domain of Ras in binding mTORC2 components, the regulation of the Ras-mTORC2 pathway is not entirely understood. In Dictyostelium, mTORC2 is selectively activated by the Ras protein RasC, and the RasC-mTORC2 pathway then mediates chemotaxis to cAMP and cellular aggregation by regulating the actin cytoskeleton and promoting cAMP signal relay. Here, we investigated the role of specific residues in RasC's SWI, C-terminal allosteric domain, and hypervariable region (HVR) related to mTORC2 activation. Interestingly, our results suggest that RasC SWI residue A31, which was previously implicated in RasC-mediated aggregation, regulates RasC's specific activation by the Aimless RasGEF. On the other hand, our investigation identified a crucial role for RasC SWI residue T36, with secondary contributions from E38 and allosteric domain residues. Finally, we found that conserved basic residues and the adjacent prenylation site in the HVR, which are crucial for RasC's membrane localization, are essential for RasC-mTORC2 pathway activation by allowing for both RasC's own cAMP-induced activation and its subsequent activation of mTORC2. Therefore, our findings revealed new determinants of RasC-mTORC2 pathway specificity in Dictyostelium, contributing to a deeper understanding of Ras signaling regulation in eukaryotic cells.

2.
CJC Pediatr Congenit Heart Dis ; 3(1): 14-21, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38544883

RESUMO

Background: Eating disorders (EDs) often develop during adolescence with high mortality rates. Sudden cardiac death in these patients has been associated with corrected QT (QTc) interval prolongation. The significance of extrinsic factors on QTc prolongation in populations with EDs remains controversial. This study assessed the relationship between QTc prolongation in paediatric patients with EDs and extrinsic factors, such as QTc-prolonging medications and electrolyte abnormalities to investigate whether an ED alone is associated with an increased prevalence of QTc prolongation. Methods: Electrocardiograms, electrolytes, and psychopharmaceutical usage were retrospectively analysed from the charts of 264 paediatric patients with EDs. Descriptive statistics were used to assess QTc prolongation and its relationship with electrolyte abnormalities and psychopharmaceuticals. Results: Of 264 patients, 227 had normal QTc intervals (<440 ms), whereas 37 had borderline prolonged (440-460 ms) or prolonged (>460 ms) intervals. The prevalence of QTc intervals exceeding 440 ms in patients with normal electrolytes and not using QTc-prolonging psychotropics mirrored that of the general population (P = 0.59). Of the 23 patients taking psychotropics, 8 had abnormal QTc intervals. The average QTc was greater for patients using QTc-prolonging psychotropics (P = 0.05) with a correlation between interval length and psychotropic usage (P < 0.01). Average potassium (P = 0.08), calcium (P = 0.18), and magnesium (P = 0.08) levels did not significantly differ between those with normal and abnormal QTc intervals. Conclusions: This study suggests that EDs alone may not prolong QTc intervals in paediatric patients with EDs, but psychotropics appear to be a salient external factor in QTc prolongation.


Contexte: Les troubles des conduites alimentaires (TCA) surviennent surtout au cours de l'adolescence et entraînent un taux de mortalité élevé. Chez ces patients, la mort subite d'origine cardiaque a été associée à un allongement de l'intervalle QT corrigé (QTc). La portée des facteurs extrinsèques sur l'allongement de cet intervalle chez les patients atteints de TCA demeure un sujet controversé. La présente étude visait à évaluer la relation entre l'allongement de l'intervalle QTc chez les enfants atteints de TCA et des facteurs extrinsèques, comme la prise de médicaments causant l'allongement de l'intervalle QTc et les anomalies électrolytiques, pour déterminer si la présence d'un TCA est à elle seule associée à une prévalence élevée d'allongement de l'intervalle QTc. Méthodologie: Nous avons analysé rétrospectivement les électrocardiogrammes, les valeurs d'électrolytes et l'utilisation de médicaments psychotropes dans les dossiers de 264 enfants atteints de TCA. Des techniques de statistique descriptive ont été utilisées pour analyser l'allongement de l'intervalle QTc et les liens avec les anomalies électrolytiques et les médicaments psychotropes. Résultats: Parmi les 264 patients, 227 présentaient un intervalle QTc normal (< 440 ms) et 37 présentaient des résultats limites (440 à 460 ms) ou un allongement de l'intervalle (> 460 ms). La prévalence d'un intervalle QTc de 440 ms ou plus chez les patients présentant des taux d'électrolytes normaux et non traités par des médicaments psychotropes causant l'allongement de l'intervalle QTc était semblable à la prévalence dans la population générale (p = 0,59). Huit des 23 patients traités par des médicaments psychotropes présentaient un intervalle QTc anormal. La moyenne des intervalles QTc était supérieure dans le groupe des patients recevant des médicaments psychotropes causant un allongement de l'intervalle QTc (p = 0,05), et il existait une corrélation entre la durée de l'intervalle et de l'usage de médicaments psychotropes (p < 0,01). Les taux moyens de potassium (p = 0,08), de calcium (p = 0,18) et de magnésium (p = 0,08) ne différaient pas de façon significative entre les groupes présentant des intervalles QTc normaux et anormaux. Conclusions: Les résultats de notre étude donnent à penser que le TCA à lui seul ne provoque pas l'allongement de l'intervalle QTc chez les enfants qui en sont atteints, mais que l'utilisation de médicaments psychotropes constitue un facteur externe important dans l'allongement de l'intervalle QTc.

3.
Diabetes ; 73(7): 1099-1111, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38345889

RESUMO

Familial partial lipodystrophy (FPLD) is a heterogenous group of syndromes associated with a high prevalence of cardiometabolic diseases. Prior work has proposed DEXA-derived fat mass ratio (FMR), defined as trunk fat percentage divided by leg fat percentage, as a biomarker of FPLD, but this metric has not previously been characterized in large cohort studies. We set out to 1) understand the cardiometabolic burden of individuals with high FMR in up to 40,796 participants in the UK Biobank and 9,408 participants in the Fenland study, 2) characterize the common variant genetic underpinnings of FMR, and 3) build and test a polygenic predictor for FMR. Participants with high FMR were at higher risk for type 2 diabetes (odds ratio [OR] 2.30, P = 3.5 × 10-41) and metabolic dysfunction-associated liver disease or steatohepatitis (OR 2.55, P = 4.9 × 10-7) in UK Biobank and had higher fasting insulin (difference 19.8 pmol/L, P = 5.7 × 10-36) and fasting triglycerides (difference 36.1 mg/dL, P = 2.5 × 10-28) in the Fenland study. Across FMR and its component traits, 61 conditionally independent variant-trait pairs were discovered, including 13 newly identified pairs. A polygenic score for FMR was associated with an increased risk of cardiometabolic diseases. This work establishes the cardiometabolic significance of high FMR, a biomarker for FPLD, in two large cohort studies and may prove useful in increasing diagnosis rates of patients with metabolically unhealthy fat distribution to enable treatment or a preventive therapy.


Assuntos
Biomarcadores , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Biomarcadores/metabolismo , Biomarcadores/sangue , Lipodistrofia Parcial Familiar/genética , Lipodistrofia Parcial Familiar/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/epidemiologia , Tecido Adiposo/metabolismo , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/genética
4.
Am J Clin Nutr ; 117(4): 802-813, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36796647

RESUMO

BACKGROUND: Recent 3-dimensional optical (3DO) imaging advancements have provided more accessible, affordable, and self-operating opportunities for assessing body composition. 3DO is accurate and precise in clinical measures made by DXA. However, the sensitivity for monitoring body composition change over time with 3DO body shape imaging is unknown. OBJECTIVES: This study aimed to evaluate the ability of 3DO in monitoring body composition changes across multiple intervention studies. METHODS: A retrospective analysis was performed using intervention studies on healthy adults that were complimentary to the cross-sectional study, Shape Up! Adults. Each participant received a DXA (Hologic Discovery/A system) and 3DO (Fit3D ProScanner) scan at the baseline and follow-up. 3DO meshes were digitally registered and reposed using Meshcapade to standardize the vertices and pose. Using an established statistical shape model, each 3DO mesh was transformed into principal components, which were used to predict whole-body and regional body composition values using published equations. Body composition changes (follow-up minus the baseline) were compared with those of DXA using a linear regression analysis. RESULTS: The analysis included 133 participants (45 females) in 6 studies. The mean (SD) length of follow-up was 13 (5) wk (range: 3-23 wk). Agreement between 3DO and DXA (R2) for changes in total FM, total FFM, and appendicular lean mass were 0.86, 0.73, and 0.70, with root mean squared errors (RMSEs) of 1.98 kg, 1.58 kg, and 0.37 kg, in females and 0.75, 0.75, and 0.52 with RMSEs of 2.31 kg, 1.77 kg, and 0.52 kg, in males, respectively. Further adjustment with demographic descriptors improved the 3DO change agreement to changes observed with DXA. CONCLUSIONS: Compared with DXA, 3DO was highly sensitive in detecting body shape changes over time. The 3DO method was sensitive enough to detect even small changes in body composition during intervention studies. The safety and accessibility of 3DO allows users to self-monitor on a frequent basis throughout interventions. This trial was registered at clinicaltrials.gov as NCT03637855 (Shape Up! Adults; https://clinicaltrials.gov/ct2/show/NCT03637855); NCT03394664 (Macronutrients and Body Fat Accumulation: A Mechanistic Feeding Study; https://clinicaltrials.gov/ct2/show/NCT03394664); NCT03771417 (Resistance Exercise and Low-Intensity Physical Activity Breaks in Sedentary Time to Improve Muscle and Cardiometabolic Health; https://clinicaltrials.gov/ct2/show/NCT03771417); NCT03393195 (Time Restricted Eating on Weight Loss; https://clinicaltrials.gov/ct2/show/NCT03393195), and NCT04120363 (Trial of Testosterone Undecanoate for Optimizing Performance During Military Operations; https://clinicaltrials.gov/ct2/show/NCT04120363).


Assuntos
Composição Corporal , Imagem Óptica , Masculino , Adulto , Feminino , Humanos , Absorciometria de Fóton/métodos , Estudos Transversais , Estudos Retrospectivos , Composição Corporal/fisiologia , Impedância Elétrica , Índice de Massa Corporal
5.
Science ; 378(6617): 290-295, 2022 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-36264814

RESUMO

Adaptations to infectious and dietary pressures shape mammalian physiology and disease risk. How such adaptations affect sex-biased diseases remains insufficiently studied. In this study, we show that sex-dependent hepatic gene programs confer a robust (~300%) survival advantage for male mice during lethal bacterial infection. The transcription factor B cell lymphoma 6 (BCL6), which masculinizes hepatic gene expression at puberty, is essential for this advantage. However, protection by BCL6 protein comes at a cost during conditions of dietary excess, which result in overt fatty liver and glucose intolerance in males. Deleting hepatic BCL6 reverses these phenotypes but markedly lowers male survival during infection, thus establishing a sex-dependent trade-off between host defense and metabolic systems. Our findings offer strong evidence that some current sex-biased diseases are rooted in ancient evolutionary trade-offs between immunity and metabolism.


Assuntos
Infecções Bacterianas , Evolução Biológica , Fígado Gorduroso , Adaptação ao Hospedeiro , Fígado , Proteínas Proto-Oncogênicas c-bcl-6 , Animais , Masculino , Camundongos , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Regulação da Expressão Gênica , Fígado/metabolismo , Adaptação ao Hospedeiro/genética , Adaptação ao Hospedeiro/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/fisiologia , Deleção de Genes , Fatores Sexuais , Infecções Bacterianas/genética , Infecções Bacterianas/imunologia
6.
Obesity (Silver Spring) ; 30(8): 1589-1598, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35894079

RESUMO

OBJECTIVE: This study examined whether body shape and composition obtained by three-dimensional optical (3DO) scanning improved the prediction of metabolic syndrome (MetS) prevalence compared with BMI and demographics. METHODS: A diverse ambulatory adult population underwent whole-body 3DO scanning, blood tests, manual anthropometrics, and blood pressure assessment in the Shape Up! Adults study. MetS prevalence was evaluated based on 2005 National Cholesterol Education Program criteria, and prediction of MetS involved logistic regression to assess (1) BMI, (2) demographics-adjusted BMI, (3) 85 3DO anthropometry and body composition measures, and (4) BMI + 3DO + demographics models. Receiver operating characteristic area under the curve (AUC) values were generated for each predictive model. RESULTS: A total of 501 participants (280 female) were recruited, with 87 meeting the criteria for MetS. Compared with the BMI model (AUC = 0.819), inclusion of age, sex, and race increased the AUC to 0.861, and inclusion of 3DO measures further increased the AUC to 0.917. The overall integrated discrimination improvement between the 3DO + demographics and the BMI model was 0.290 (p < 0.0001) with a net reclassification improvement of 0.214 (p < 0.0001). CONCLUSIONS: Body shape measures from an accessible 3DO scan, adjusted for demographics, predicted MetS better than demographics and/or BMI alone. Risk classification in this population increased by 29% when using 3DO scanning.


Assuntos
Síndrome Metabólica , Somatotipos , Adulto , Antropometria/métodos , Composição Corporal/fisiologia , Índice de Massa Corporal , Feminino , Humanos , Síndrome Metabólica/diagnóstico por imagem , Síndrome Metabólica/epidemiologia , Curva ROC , Fatores de Risco , Circunferência da Cintura
7.
JMIR Mhealth Uhealth ; 10(3): e33940, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35285809

RESUMO

BACKGROUND: Low-carbohydrate ketogenic diets are a viable method to lose weight that have regained popularity in recent years. Technology in the form of mobile health (mHealth) apps allows for scalable and remote delivery of such dietary interventions and are increasingly being used by the general population without direct medical supervision. However, it is currently unknown which factors related to app use and user behavior are associated with successful weight loss. OBJECTIVE: First, to describe and characterize user behavior, we aim to examine characteristics and user behaviors over time of participants who were enrolled in a remotely delivered clinical weight loss trial that tested an mHealth ketogenic diet app paired with a breath acetone biofeedback device. Second, to identify variables of importance to weight loss at 12 weeks that may offer insight for future development of dietary mHealth interventions, we aim to explore which app- and adherence-related user behaviors characterized successful weight loss. METHODS: We analyzed app use and self-reported questionnaire data from 75 adults with overweight or obesity who participated in the intervention arm of a previous weight loss study. We examined data patterns over time through linear mixed models and performed correlation, linear regression, and causal mediation analyses to characterize diet-, weight-, and app-related user behavior associated with weight loss. RESULTS: In the context of a low-carbohydrate ketogenic diet intervention delivered remotely through an mHealth app paired with a breath acetone biofeedback device, self-reported dietary adherence seemed to be the most important factor to predict weight loss (ß=-.31; t54=-2.366; P=.02). Furthermore, self-reported adherence mediated the relationship between greater app engagement (from c=-0.008, 95% CI -0.014 to -0.0019 to c'=-0.0035, 95% CI -0.0094 to 0.0024) or higher breath acetone levels (from c=-1.34, 95% CI -2.28 to -0.40 to c'=-0.40, 95% CI -1.42 to 0.62) and greater weight loss, explaining a total of 27.8% and 28.8% of the variance in weight loss, respectively. User behavior (compliance with weight measurements and app engagement) and adherence-related aspects (breath acetone values and self-reported dietary adherence) over time differed between individuals who achieved a clinically significant weight loss of >5% and those who did not. CONCLUSIONS: Our in-depth examination of app- and adherence-related user behaviors offers insight into factors associated with successful weight loss in the context of mHealth interventions. In particular, our finding that self-reported dietary adherence was the most important metric predicting weight loss may aid in the development of future mHealth dietary interventions. TRIAL REGISTRATION: ClinicalTrials.gov NCT04165707; https://clinicaltrials.gov/ct2/show/NCT04165707. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/19053.


Assuntos
Dieta Cetogênica , Aplicativos Móveis , Telemedicina , Adulto , Humanos , Obesidade/terapia , Sobrepeso , Redução de Peso
8.
Clin Nutr ; 41(1): 211-218, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34915272

RESUMO

BACKGROUND: The accurate assessment of total body and regional body circumferences, volumes, and compositions are critical to monitor physical activity and dietary interventions, as well as accurate disease classifications including obesity, metabolic syndrome, sarcopenia, and lymphedema. We assessed body composition and anthropometry estimates provided by a commercial 3-dimensional optical (3DO) imaging system compared to criterion measures. METHODS: Participants of the Shape Up! Adults study were recruited for similar sized stratifications by sex, age (18-40, 40-60, >60 years), BMI (under, normal, overweight, obese), and across five ethnicities (non-Hispanic [NH] Black, NH White, Hispanic, Asian, Native Hawaiian/Pacific Islander). All participants received manual anthropometry assessments, duplicate whole-body 3DO (Styku S100), and dual-energy X-ray absorptiometry (DXA) scans. 3DO estimates provided by the manufacturer for anthropometry and body composition were compared to the criterion measures using concordance correlation coefficient (CCC) and Bland-Altman analysis. Test-retest precision was assessed by root mean square error (RMSE) and coefficient of variation. RESULTS: A total of 188 (102 female) participants were included. The overall fat free mass (FFM) as measured by DXA (54.1 ± 15.2 kg) and 3DO (55.3 ± 15.0 kg) showed a small mean difference of 1.2 ± 3.4 kg (95% limits of agreement -7.0 to +5.6) and the CCC was 0.97 (95% CI: 0.96-0.98). The CCC for FM was 0.95 (95% CI: 0.94-0.97) and the mean difference of 1.3 ± 3.4 kg (95% CI: -5.5 to +8.1) reflected the difference in FFM measures. 3DO anthropometry and body composition measurements showed high test-retest precision for whole body volume (1.1 L), fat mass (0.41 kg), percent fat (0.60%), arm and leg volumes, (0.11 and 0.21 L, respectively), and waist and hip circumferences (all <0.60 cm). No group differences were observed when stratified by body mass index, sex, or race/ethnicity. CONCLUSIONS: The anthropometric and body composition estimates provided by the 3DO scanner are precise and accurate to criterion methods if offsets are considered. This method offers a rapid, broadly available, and automated method of body composition assessment regardless of body size. Further studies are recommended to examine the relationship between measurements obtained by 3DO scans and metabolic health in healthy and clinical populations.


Assuntos
Antropometria/instrumentação , Composição Corporal , Imageamento Tridimensional/instrumentação , Imagem Corporal Total/instrumentação , Absorciometria de Fóton , Adolescente , Adulto , Antropometria/métodos , Índice de Massa Corporal , Feminino , Humanos , Imageamento Tridimensional/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Imagem Corporal Total/métodos , Adulto Jovem
9.
Am J Clin Nutr ; 114(4): 1455-1466, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34159352

RESUMO

BACKGROUND: LDL particle size and number (LDL-P) are emerging lipid risk factors. Nonsystematic reviews have suggested that diets lower in carbohydrates and higher in fats may result in increased LDL particle size when compared with higher-carbohydrate diets. OBJECTIVES: This study aimed to systematically review available evidence and conduct meta-analyses of studies addressing the association of carbohydrate restriction with LDL particle size and LDL-P. METHODS: We searched 6 electronic databases on 4 January, 2021 for randomized trials of any length that reported on dietary carbohydrate restriction (intervention) compared with higher carbohydrate intake (control). We calculated standardized mean differences (SMDs) in LDL particle size and LDL-P between the intervention and control groups of eligible studies, and pooled effect sizes using random-effects models. We performed prespecified subgroup analyses and examined the effect of potential explanatory factors. Internal validity and publication bias were assessed using Cochrane's risk-of-bias tool and funnel plots, respectively. Studies that could not be meta-analyzed were summarized qualitatively. RESULTS: This review summarizes findings from 38 randomized trials including a total of 1785 participants. Carbohydrate-restricted dietary interventions were associated with an increase in LDL peak particle size (SMD = 0.50; 95% CI: 0.15, 0.86; P < 0.01) and a reduction in LDL-P (SMD = -0.24; 95% CI: -0.43, -0.06; P = 0.02). The effect of carbohydrate-restricted dietary interventions on LDL peak particle size appeared to be partially explained by differences in weight loss between intervention groups and exploratory analysis revealed a shift from small dense to larger LDL subclasses. No statistically significant association was found between carbohydrate-restricted dietary interventions and mean LDL particle size (SMD = 0.20; 95% CI: -0.29, 0.69; P = 0.37). CONCLUSIONS: The available evidence indicates that dietary interventions restricted in carbohydrates increase LDL peak particle size and decrease the numbers of total and small LDL particles.This review was registered at www.crd.york.ac.uk/prospero/ as CRD42020188745.


Assuntos
LDL-Colesterol/sangue , Carboidratos da Dieta/administração & dosagem , Carboidratos da Dieta/farmacologia , Redução de Peso , Humanos
10.
Obesity (Silver Spring) ; 29(10): 1606-1614, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34124856

RESUMO

OBJECTIVE: The aim of this study was to determine whether a Mediterranean-style, ketogenic diet mobile health application (app) with breath acetone biofeedback is superior to a calorie-restricted, low-fat diet app in promoting weight loss. METHODS: Participants (n = 155) with overweight/obesity (mean [SD]: age 41 [11] years, BMI = 34 [5] kg/m2 , 71% female) were randomized to one of the interventions delivered entirely via app. Participants received a wireless scale and were instructed to take daily weight measurements. A third-party laboratory collected blood samples at baseline and 12 weeks. RESULTS: Weight loss at 12 weeks was greater in the ketogenic (-5.6 kg; 95% CI: -6.7 kg to -4.5 kg) compared with the low-fat group (-2.5 kg; 95% CI: -3.6 kg to -1.4 kg) (between-group difference: -3.1 kg; 95% CI: -4.6 kg to -1.5 kg; p < 0.001). Weight loss at 24 weeks indicated durability of the effect (between-group difference: -5.5 kg; 95% CI: -8.3 kg to -2.8 kg; p < 0.001). Secondary/exploratory outcomes of hemoglobin A1c and liver enzymes were improved to a greater extent in the ketogenic diet group (p < 0.01). CONCLUSIONS: Among adults with overweight/obesity, a ketogenic diet app with breath acetone biofeedback was superior to a calorie-restricted diet app at promoting weight loss in a real-world setting.


Assuntos
Aplicativos Móveis , Sobrepeso , Adulto , Feminino , Hemoglobinas Glicadas , Humanos , Masculino , Obesidade/terapia , Sobrepeso/terapia , Redução de Peso
11.
J Lipid Res ; 62: 100051, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33631213

RESUMO

Oxysterols are oxidized derivatives of cholesterol that play regulatory roles in lipid biosynthesis and homeostasis. How oxysterol signaling coordinates different lipid classes such as sterols and triglycerides remains incompletely understood. Here, we show that 4ß-hydroxycholesterol (HC) (4ß-HC), a liver and serum abundant oxysterol of poorly defined functions, is a potent and selective inducer of the master lipogenic transcription factor, SREBP1c, but not the related steroidogenic transcription factor SREBP2. By correlating tracing of lipid synthesis with lipogenic gene expression profiling, we found that 4ß-HC acts as a putative agonist for the liver X receptor (LXR), a sterol sensor and transcriptional regulator previously linked to SREBP1c activation. Unique among the oxysterol agonists of the LXR, 4ß-HC induced expression of the lipogenic program downstream of SREBP1c and triggered de novo lipogenesis both in primary hepatocytes and in the mouse liver. In addition, 4ß-HC acted in parallel to insulin-PI3K-dependent signaling to stimulate triglyceride synthesis and lipid-droplet accumulation. Thus, 4ß-HC is an endogenous regulator of de novo lipogenesis through the LXR-SREBP1c axis.


Assuntos
Proteína de Ligação a Elemento Regulador de Esterol 1
13.
Surg Endosc ; 35(12): 6549-6555, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33196877

RESUMO

AIMS: The increased use of endoscopy as a minimally invasive therapeutic technique has created a great demand for endoscopic training. The Basic Endoscopic Skills Training (BEST) box provides a low-cost solution by adapting the Fundamentals of Laparoscopic Surgery (FLS) box for flexible endoscopic simulation. The BEST box consists of six endoscopic tasks with a 5-min time limit per task. This study aims to develop a scoring system for objective evaluation of user performance. METHODS: A total of 165 participants were tested on the BEST box. Participants were divided into two groups: retrospective analysis (n = 100) and prospective analysis (n = 65). From the retrospective group, 55 individuals were also scored on the Global Assessment of Gastrointestinal Endoscopic Skills-Upper Endoscopy (GAGES-UE). Linear regression between user performance on BEST box and GAGES-UE was performed to develop the scoring system. Receiver Operating Characteristic curve was used to determine a threshold score to help users appreciate their endoscopic expertise. Prospective scoring of 65 individuals was then performed using the formula developed (20 experts and 45 trainees). RESULTS: The minimum and maximum possible scores are 30 and 110, respectively. Retrospective analysis showed that the scoring system was able to distinguish between experts and trainees (p < 0.001), correlated with GAGES-UE (p < 0.001), and had a reliability constant of r = 0.765 (p < 0.001). On prospective testing using the scoring system the expert group received a final average score of 92, whereas the average score for the trainee group was 61 (p < 0.001). CONCLUSIONS: The developed BEST box scoring system correlates with the experience level of the test taker as well as with the GAGES-UE scoring system. The results of this study add further evidence to the validity of the BEST box as an effective, low-cost endoscopic simulator with the scores used by trainees to track their performance level overtime.


Assuntos
Laparoscopia , Treinamento por Simulação , Competência Clínica , Simulação por Computador , Endoscopia Gastrointestinal , Humanos , Reprodutibilidade dos Testes , Estudos Retrospectivos
14.
JAMA Intern Med ; 180(11): 1491-1499, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32986097

RESUMO

Importance: The efficacy and safety of time-restricted eating have not been explored in large randomized clinical trials. Objective: To determine the effect of 16:8-hour time-restricted eating on weight loss and metabolic risk markers. Interventions: Participants were randomized such that the consistent meal timing (CMT) group was instructed to eat 3 structured meals per day, and the time-restricted eating (TRE) group was instructed to eat ad libitum from 12:00 pm until 8:00 pm and completely abstain from caloric intake from 8:00 pm until 12:00 pm the following day. Design, Setting, and Participants: This 12-week randomized clinical trial including men and women aged 18 to 64 years with a body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) of 27 to 43 was conducted on a custom mobile study application. Participants received a Bluetooth scale. Participants lived anywhere in the United States, with a subset of 50 participants living near San Francisco, California, who underwent in-person testing. Main Outcomes and Measures: The primary outcome was weight loss. Secondary outcomes from the in-person cohort included changes in weight, fat mass, lean mass, fasting insulin, fasting glucose, hemoglobin A1c levels, estimated energy intake, total energy expenditure, and resting energy expenditure. Results: Overall, 116 participants (mean [SD] age, 46.5 [10.5] years; 70 [60.3%] men) were included in the study. There was a significant decrease in weight in the TRE (-0.94 kg; 95% CI, -1.68 to -0.20; P = .01), but no significant change in the CMT group (-0.68 kg; 95% CI, -1.41 to 0.05, P = .07) or between groups (-0.26 kg; 95% CI, -1.30 to 0.78; P = .63). In the in-person cohort (n = 25 TRE, n = 25 CMT), there was a significant within-group decrease in weight in the TRE group (-1.70 kg; 95% CI, -2.56 to -0.83; P < .001). There was also a significant difference in appendicular lean mass index between groups (-0.16 kg/m2; 95% CI, -0.27 to -0.05; P = .005). There were no significant changes in any of the other secondary outcomes within or between groups. There were no differences in estimated energy intake between groups. Conclusions and Relevance: Time-restricted eating, in the absence of other interventions, is not more effective in weight loss than eating throughout the day. Trial Registration: ClinicalTrials.gov Identifiers: NCT03393195 and NCT03637855.


Assuntos
Restrição Calórica/métodos , Dietoterapia/métodos , Jejum/fisiologia , Obesidade/dietoterapia , Obesidade/metabolismo , Adulto , Glicemia/metabolismo , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/terapia , Cooperação do Paciente , Redução de Peso , Adulto Jovem
15.
JMIR Res Protoc ; 9(8): e19053, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32804087

RESUMO

BACKGROUND: Obesity and being overweight are major contributing factors for many diseases. Calorie restricted diets often fail to result in sustained long-term weight loss. Very low-carbohydrate, high-fat ketogenic diets have been suggested to have superior metabolic and weight loss effects. Keyto is a low-cost, highly scalable mobile health (mHealth) app paired with a noninvasive biofeedback tool aimed at facilitating weight loss through a personalized healthy and predominantly plant- and fish-based ketogenic diet. OBJECTIVE: This protocol describes a randomized trial comparing the efficacy of the Keyto mHealth app and device intervention to that of Weight Watchers' WW app in individuals who are overweight or obese. The primary outcome is weight loss after 12 weeks. Secondary and exploratory outcomes, including metabolic and cardiovascular risk factors, will be assessed at 12, 24, and 48 weeks. METHODS: A total of 144 participants will be recruited and randomized to either the Keyto program or Weight Watchers program. Study participants will be guided through the study via video conference or phone calls and will undergo a fasting blood analysis performed by a third-party diagnostic lab at weeks 0 and 12 to assess metabolic and cardiovascular risk markers. All participants will be asked to weigh themselves daily on a study-provided Bluetooth-enabled scale. Participants randomized to the Keyto arm will also be asked to measure their breath acetone levels, a measure of ketosis, with the Keyto device 3 times per day. RESULTS: Recruitment started in December 2019. Rolling recruitment is expected to be completed by July 2020. Data collection and analysis of the primary intervention phase is expected to be completed in October 2020. The 24- and 48-week follow-ups are expected to be completed in January 2021 and July 2021, respectively. CONCLUSIONS: This trial will provide high-quality evidence regarding the efficacy of the Keyto weight loss program in individuals who are overweight and obese in a free-living condition. This study also fills a gap by examining the impact of a ketogenic diet emphasizing plant- and fish-based fats on blood lipid profile and cardiovascular disease risk. TRIAL REGISTRATION: ClinicalTrials.gov NCT04165707; https://clinicaltrials.gov/ct2/show/NCT04165707. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/19053.

16.
Perspect Biol Med ; 63(1): 66-72, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32063587

RESUMO

Ruthie Weiss was born with white hair, but her parents did not consider the possibility of there being more to the story until they noticed that she was not visually tracking when she was just a month old. Thus began a long and continuing story of the discovery of Ruthie's albinism, her significant visual impairment, but also her courage and determination to do anything and everything her peers do, if not more. But this story is really about how her parents grew to embrace the impact Ruthie (and importantly Ruthie's disability) had on their lives and the lives of everyone with whom Ruthie interacted. The experience of raising Ruthie ultimately led her parents to think about a world where she might not exist, or at least might not exist with albinism. But it also led them to ponder a future in which children with genetic differences like albinism are gene edited using technologies like CRISPR-Cas9.


Assuntos
Albinismo Oculocutâneo/etiologia , Pais , Albinismo Oculocutâneo/genética , Albinismo Oculocutâneo/psicologia , Criança , Feminino , Testes Genéticos , Humanos , Masculino , Pais/psicologia
17.
Curr Dev Nutr ; 4(6): nzaa090, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33959689

RESUMO

BACKGROUND: Visceral adiposity, more so than overall adiposity, is associated with chronic disease and mortality. There has been, to our knowledge, little research exploring the association between diet quality and visceral adipose tissue (VAT) among a mulitethnic population aged 18-80 y. OBJECTIVE: The primary objective of this cross-sectional analysis was to examine the association between diet quality [Healthy Eating Index-2010 (HEI-2010) scores] and VAT among a multiethnic population of young, middle, and older aged adults in the United States. Secondary objectives were to repeat these analyses with overall adiposity and blood-based biomarkers for type 2 diabetes and cardiovascular disease risk as outcome measures. METHODS: A total of 540 adults (dropped out: n = 4; age: 18-40 y, n = 220; 40-60 y, n = 183; 60-80 y, n = 133) were recruited across 3 sites (Honolulu County, San Francisco, and Baton Rouge) for the Shape Up! Adults study. Whole-body DXA, anthropometry, fasting blood draw, and questionnaires (food frequency, physical activity, and demographic characteristics) were completed. Linear regression was used to assess the associations between HEI-2010 tertiles and VAT and secondary outcome measures among all participants and age-specific strata, while adjusting for known confounders. RESULTS: VAT, BMI (kg/m2), body fat percentage, total body fat, trunk fat, insulin, and insulin resistance were inversely related to diet quality (all P values < 0.004). When stratified by age, diet quality was inversely associated with VAT among participants aged 60-80 y (P < 0.006) and VAT/subcutaneous adipose tissue (SAT) among participants aged 40-60 y (P < 0.008). CONCLUSIONS: Higher-quality diet was associated with lower VAT, overall adiposity, and insulin resistance among this multiethnic population of young, middle, and older aged adults with ages ranging from 18 to 80 y. More specifically, adherence to a high-quality diet may minimize VAT accumulation in adults aged 60-80 y and preferentially promote storage of SAT compared with VAT in adults aged 40-60 y.This study was registered at clinicaltrials.gov as NCT03637855.

18.
JCI Insight ; 52019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31393852

RESUMO

Non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) are liver manifestations of the metabolic syndrome and can progress to hepatocellular carcinoma (HCC). Loss of Growth Hormone (GH) signaling is reported to predispose to NAFLD and NASH through direct actions on the liver. Here, we report that aged mice lacking hepatocyte Jak2 (JAK2L), an obligate transducer of Growth Hormone (GH) signaling, spontaneously develop the full spectrum of phenotypes found in patients with metabolic liver disease, beginning with insulin resistance and lipodystrophy and manifesting as NAFLD, NASH and even HCC, independent of dietary intervention. Remarkably, insulin resistance, metabolic liver disease, and carcinogenesis are prevented in JAK2L mice via concomitant deletion of adipocyte Jak2 (JAK2LA). Further, we demonstrate that GH increases hepatic lipid burden but does so indirectly via signaling through adipocyte JAK2. Collectively, these data establish adipocytes as the mediator of GH-induced metabolic liver disease and carcinogenesis. In addition, we report a new spontaneous model of NAFLD, NASH, and HCC that recapitulates the natural sequelae of human insulin resistance-associated disease progression. The work presented here suggests a attention be paid towards inhibition of adipocyte GH signaling as a therapeutic target of metabolic liver disease.


Assuntos
Adipócitos/metabolismo , Carcinoma Hepatocelular/metabolismo , Fígado Gorduroso/metabolismo , Janus Quinase 2/metabolismo , Neoplasias Hepáticas/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Adipócitos/patologia , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Animais , Carcinogênese/metabolismo , Modelos Animais de Doenças , Fígado Gorduroso/patologia , Hormônio do Crescimento , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Resistência à Insulina , Janus Quinase 2/genética , Fígado/metabolismo , Fígado/patologia , Masculino , Síndrome Metabólica/complicações , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/patologia , Transdução de Sinais
19.
Surg Endosc ; 33(10): 3444-3450, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30604259

RESUMO

BACKGROUND: The paucity of readily accessible, cost-effective models for the simulation, practice, and evaluation of endoscopic skills present an ongoing barrier for resident training. We have previously described a system for conversion of the Fundamentals of Laparoscopic Surgery box (FLS) for flexible endoscopic simulation. Six endoscopic tasks focusing on scope manipulation, and other clinically relevant endoscopic skills are performed within a 5-min time limit per task. This study describes our experience and validation results with the first 100 participants. METHODS: A total of 100 participants were evaluated on the simulator. Thirty individuals were classified as experts (having done over 200 endoscopic procedures), and 70 were classified as trainees (39 individuals reported having no prior endoscopy experience). Of the 100 participants, 55 individuals were retested on the simulator within a period of 4 months. These 55 individuals were also evaluated using the "Global Assessment of Gastrointestinal Endoscopic Skills" (GAGES). T-tests and Pearson correlations were used where appropriate, values less than 0.05 were considered significant. RESULTS: Experts completed all six tasks significantly faster than trainees. For the 55 participants who were retested on the simulator, all tasks demonstrated evidence of test-retest reliability for both experts and trainees who did not practice in between tests. Moderate correlations between lower completion times and higher GAGES scores were observed for all tasks except the clipping task. CONCLUSIONS: The results from the first 100 participants provide evidence for the simulator's validity. Based on task completion times, we found that experts perform significantly better than trainees. Additionally, preliminary data demonstrate evidence of test-retest reliability, as well as GAGES score correlation. Additional studies to determine and validate a scoring system for this simulator are ongoing.


Assuntos
Endoscopia Gastrointestinal/educação , Laparoscopia/educação , Treinamento por Simulação/métodos , Adulto , Competência Clínica , Simulação por Computador , Feminino , Humanos , Internato e Residência/métodos , Masculino , Reprodutibilidade dos Testes , Análise e Desempenho de Tarefas
20.
Surg Endosc ; 32(6): 2968-2983, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29611046

RESUMO

BACKGROUND: The fundamentals of laparoscopic surgery (FLS) training box is a validated tool, already accessible to surgical trainees to hone their laparoscopic skills. We aim to investigate the feasibility of adapting the FLS box for the practice and assessment of endoscopic skills. This would allow for a highly available, reusable, low-cost, mechanical trainer. METHODS: The design and development process was based on a user-centered design, which is a combination of the design thinking method and cognitive task analysis. The process comprises four phases: empathy, cognitive, prototyping/adaptation, and end user testing. The underlying idea was to utilize as many of the existing components of FLS training to maintain simplicity and cost effectiveness while allowing for the practice of clinically relevant endoscopic skills. A sample size of 18 participants was calculated to be sufficient to detect performance differences between experts and trainees using a two tailed t test with alpha set at 0.05, standard deviation of 5.5, and a power of 80%. RESULTS: Adaptation to the FLS box included two fundamental attachments: a front panel with an insertion point for an endoscope and a shaft which provides additional support and limits movement of the scope. The panel also allows for mounting of retroflexion tasks. Six endoscopic tasks inspired by FLS were designed (two of which utilize existing FLS components). Pilot testing with 38 participants showed high user's satisfaction and demonstrated that the trainer was robust and reliable. Task performance times was able to discriminate between trainees and experts for all six tasks. CONCLUSIONS: A mechanical, reusable, low-cost adaptation of the FLS training box for endoscopic skills is feasible and has high user satisfaction. Preliminary testing shows that the simulator is able to discriminate between trainees and experts. Following further validation, this adaptation may act as a supplement to the FES program.


Assuntos
Endoscopia/educação , Treinamento por Simulação , Avaliação Educacional , Desenho de Equipamento , Estudos de Viabilidade , Humanos
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