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1.
Nat Commun ; 15(1): 2655, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38531894

RESUMEN

Genetic pleiotropy is abundant across spatially distributed brain characteristics derived from one neuroimaging modality (e.g. structural, functional or diffusion magnetic resonance imaging [MRI]). A better understanding of pleiotropy across modalities could inform us on the integration of brain function, micro- and macrostructure. Here we show extensive genetic overlap across neuroimaging modalities at a locus and gene level in the UK Biobank (N = 34,029) and ABCD Study (N = 8607). When jointly analysing phenotypes derived from structural, functional and diffusion MRI in a genome-wide association study (GWAS) with the Multivariate Omnibus Statistical Test (MOSTest), we boost the discovery of loci and genes beyond previously identified effects for each modality individually. Cross-modality genes are involved in fundamental biological processes and predominantly expressed during prenatal brain development. We additionally boost prediction of psychiatric disorders by conditioning independent GWAS on our multimodal multivariate GWAS. These findings shed light on the shared genetic mechanisms underlying variation in brain morphology, functional connectivity, and tissue composition.


Asunto(s)
Estudio de Asociación del Genoma Completo , Neuroimagen , Humanos , Estudio de Asociación del Genoma Completo/métodos , Fenotipo , Pleiotropía Genética , Encéfalo/anatomía & histología , Polimorfismo de Nucleótido Simple , Predisposición Genética a la Enfermedad
2.
Sports Med Int Open ; 8: a21930922, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38312924

RESUMEN

Purpose EXERT-BC is a dose-escalated resistance training regimen created to improve body composition, strength, and balance in women treated for breast cancer (BC). Herein, we report the interim analysis. Women treated for BC underwent this 3-month exercise regimen in an exercise oncology facility with continual monitoring of load and strength. Twenty women completed the IRB-approved protocol, with a mean age of 57 years (range 41-74). Concurrent therapies included anti-estrogen therapy (73%), chemotherapy (14%), and radiotherapy (23%). 27% of women endorsed prior exercise. Subjects missed an average of 1.75 classes (range 0-7), with all meeting adherence over 75%. No injuries or adverse events were reported aside from muscle soreness and 2 days of knee pain. Significant differences in body composition at completion included reduced body fat (38.2% vs. 36.7%, p=0.003), and increased muscle mass (33.1% vs. 37.1%, p<0.001), functional mobility screening (9.82 vs. 11.73, p=0.018), and Y-balance (left: 72.4 vs. 85.3, p=0.001; right: 70.3 vs. 85.2. p<0.001). Significant increases in load were demonstrated: split squat (p<0.001), trap bar deadlift (p=0.035), inclined dumbbell press (p<0.001), and bird dog rows (p<0.001). Dose-escalated resistance training in women with BC is safe and feasible, endorsing significant improvements across body composition, balance, and strength.

3.
PLoS One ; 19(1): e0296523, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38166036

RESUMEN

PURPOSE: Ketogenic diets may positively influence cancer through pleiotropic mechanisms, but only a few small and short-term studies have addressed feasibility and efficacy in cancer patients. The primary goals of this study were to evaluate the feasibility and the sustained metabolic effects of a personalized well-formulated ketogenic diet (WFKD) designed to achieve consistent blood beta-hydroxybutyrate (ßHB) >0.5 mM in women diagnosed with stage IV metastatic breast cancer (MBC) undergoing chemotherapy. METHODS: Women (n = 20) were enrolled in a six month, two-phase, single-arm WFKD intervention (NCT03535701). Phase I was a highly-supervised, ad libitum, personalized WFKD, where women were provided with ketogenic-appropriate food daily for three months. Phase II transitioned women to a self-administered WFKD with ongoing coaching for an additional three months. Fasting capillary ßHB and glucose were collected daily; weight, body composition, plasma insulin, and insulin resistance were collected at baseline, three and six months. RESULTS: Capillary ßHB indicated women achieved nutritional ketosis (Phase I mean: 0.8 mM (n = 15); Phase II mean: 0.7 mM (n = 9)). Body weight decreased 10% after three months, primarily from body fat. Fasting plasma glucose, plasma insulin, and insulin resistance also decreased significantly after three months (p < 0.01), an effect that persisted at six months. CONCLUSIONS: Women diagnosed with MBC undergoing chemotherapy can safely achieve and maintain nutritional ketosis, while improving body composition and insulin resistance, out to six months.


Asunto(s)
Neoplasias de la Mama , Dieta Cetogénica , Resistencia a la Insulina , Insulinas , Cetosis , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Estudios de Factibilidad , Ácido 3-Hidroxibutírico
4.
JMIR Res Protoc ; 12: e49243, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-38055312

RESUMEN

BACKGROUND: Mental health problems during pregnancy and post partum are common and associated with negative short- and long-term impacts on pregnant individuals, obstetric outcomes, and child socioemotional development. Socio-environmental factors are important predictors of perinatal mental health, but the effects of the environment on mental health are heterogeneous. The differential susceptibility theory and the environmental sensitivity framework suggest that individuals differ in their degree of sensitivity to positive and negative environments, which can be captured by individual phenotypes such as temperament and personality. While there is strong evidence for these models in childhood, few studies examined them in adults, and they were not examined in pregnancy. OBJECTIVE: The primary objective of the Experiences of Pregnancy study is to explore whether childhood and current environments are associated with mental health and well-being in pregnancy and whether these effects depend on individual sensitivity phenotypes (personality). This study also aims to gather important psychosocial and health data for potential secondary data analyses and integrative data analyses. METHODS: We will conduct a longitudinal cohort study. The study was not registered elsewhere, other than this protocol. Participants will be recruited through social media advertisements linking to the study website, followed by an eligibility call on Zoom (Zoom Video Communications). Participants must be aged 18 years or older, currently residing in the United States as citizens or permanent residents, and currently planning to continue the pregnancy. A minimum of 512 participants will be recruited based on power analyses for the main objectives. Since the data will also be a resource for secondary analyses, up to 1000 participants will be recruited based on the available budget. Participants will be in their first trimester of pregnancy, and they will be followed at each trimester and once post partum. Data will be obtained through self-reported questionnaires assessing demographic factors; pregnancy-related factors; delivery, labor, and birth outcomes; early infant feeding; individual personality factors; childhood and current environments; mental health and well-being; attachment; and infant temperament. A series of measures were taken to safeguard the study from web robots and fraudulent participants, as well as to reduce legal and social risks for participants following Dobbs v. Jackson. RESULTS: The study received ethics approval in April 2023 from the University of Oklahoma-Norman Campus Institutional Review Board. Recruitment occurred from May to August 2023, with 3 follow-ups occurring over 10 months. CONCLUSIONS: The Experiences of Pregnancy study will extend theories of environmental sensitivity, mainly applied in children to the perinatal period. This will help better understand individual sensitivity factors associated with risk, resilience, plasticity, and receptivity to negative and positive environmental influences during pregnancy for pregnant individuals. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/49243.

5.
Curr Stem Cell Rep ; 9(4): 57-66, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38145008

RESUMEN

Purpose of Review: To explore the advances and future research directions in image analysis and computational modelling of human stem cells (hSCs) for ophthalmological applications. Recent Findings: hSCs hold great potential in ocular regenerative medicine due to their application in cell-based therapies and in disease modelling and drug discovery using state-of-the-art 2D and 3D organoid models. However, a deeper characterisation of their complex, multi-scale properties is required to optimise their translation to clinical practice. Image analysis combined with computational modelling is a powerful tool to explore mechanisms of hSC behaviour and aid clinical diagnosis and therapy. Summary: Many computational models draw on a variety of techniques, often blending continuum and discrete approaches, and have been used to describe cell differentiation and self-organisation. Machine learning tools are having a significant impact in model development and improving image classification processes for clinical diagnosis and treatment and will be the focus of much future research.

6.
Pediatr Cardiol ; 44(4): 836-844, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36933014

RESUMEN

Supraventricular tachycardia (SVT) is the most common arrhythmia among infants. Prevention of SVT is frequently managed through propranolol therapy. Hypoglycemia is a known adverse effect of propranolol therapy, but little research has been done on the incidence and risk of hypoglycemia in treatment of SVT in infants with propranolol. This study attempts to offer insight into the risk of hypoglycemia associated with propranolol therapy when treating infantile SVT to help inform future glucose screening guidelines. We conducted a retrospective chart review of infants treated with propranolol in our hospital system. Inclusion criteria were infants < 1 year of age who received propranolol for the treatment of SVT. A total of 63 patients were identified. Data was collected on sex, age, race, diagnosis, gestational age, nutrition source (Total Parenteral Nutrition (TPN) vs oral), weight (kg), weight for length (kg/cm), propranolol dose (mg/kg/day), comorbidities, and whether or not a hypoglycemic event was identified (< 60 mg/dL). Hypoglycemic events were identified in 9/63 (14.3%) patients. Of the patients with hypoglycemic events, 9/9 (88.9%) had comorbid conditions. Patients with hypoglycemic events had significantly lower weight and propranolol dose than those without hypoglycemic events. Weight for length also tended to increase risk for hypoglycemic events. The high incidence of comorbid conditions in the patients who had hypoglycemic events suggests that hypoglycemic monitoring may only be necessary in patients with conditions predisposing to hypoglycemia.


Asunto(s)
Hipoglucemia , Taquicardia Supraventricular , Lactante , Humanos , Propranolol/efectos adversos , Antiarrítmicos/uso terapéutico , Estudios Retrospectivos , Taquicardia Supraventricular/tratamiento farmacológico , Taquicardia Supraventricular/diagnóstico , Hipoglucemia/inducido químicamente , Hipoglucemia/tratamiento farmacológico , Hipoglucemiantes/efectos adversos
7.
Clin Nutr ESPEN ; 54: 277-287, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36963874

RESUMEN

BACKGROUND: Single doses of exogenous ketone salts (KS) transiently increase circulating beta-hydroxybutyrate (BHB) (∼1 mM; 1-2 h) regardless of starting levels of ketosis; however, no studies have explored how sustained use of KS influences measures of ketonemia and glycemia. OBJECTIVES: To determine the response to a hypocaloric, well-formulated ketogenic diet (KD), with and without the inclusion of two daily racemic KS doses (6 g R-BHB + 6 g S-BHB per serving) on 1) daily fasting capillary R-BHB and glucose (R-BHB/GLUfast), 2) bi-weekly 13 h diurnal BHB and glucose (R-BHB/GLUdiur), 3) three-hours post-KS ingestion kinetics (R-BHBKS), and 4) bi-weekly fasting plasma enantiomer-specific BHB (R/S-BHBplasma). METHODS: Non-diabetic adults with overweight and obesity were randomized to receive a precisely measured hypocaloric KD (∼75 %en of maintenance) for six weeks, supplemented twice-daily with KS or placebo (PL). A non-randomized comparison group was provided an isonitrogenous/isoenergetic low-fat diet (LFD). All meals were provided to subjects. Capillary blood was collected daily to measure R-BHB/GLUfast and hourly for R-BHB/GLUdiur. Plasma was collected to measure R/S-BHBplasma, insulin, fasting glucose, and insulin resistance (HOMA-IR). Total AUC was calculated using the trapezoidal method. RESULTS: Mean R-BHBfast increased significantly during KD + PL (1.0 mM BHB), an effect enhanced 26% during KD + KS. GLUfast AUC was -6% lower during KD + KS versus LFD. Mean R-BHBdiur increased 40% in KD + KS versus KD + PL, whereas GLUdiur decreased 13% during both KDs versus LFD. R-BHBKS peaked (Δ: ∼1 mM) 1 h after the morning KS dose, but not following the afternoon dose. Both R/S-BHBplasma increased during KD independent of KS inclusion. R-BHBplasma was 50-times greater compared to S-BHBplasma, and the KS augmented S-BHBplasma 50% more than PL. Fasting insulin and HOMA-IR decreased after 14 days independent of diet. CONCLUSIONS: A hypocaloric KD was effective at reducing diurnal glucose compared to a LFD independent of weight loss, but twice-daily racemic KS ingestion during KD augmented ketonemia, both as R- and S-BHB, and decreased mean fasting glucose beyond a KD alone. The hypoglycemic effects of KD in combination with exogenous ketones merit further investigation.


Asunto(s)
Dieta Cetogénica , Cetosis , Adulto , Humanos , Ácido 3-Hidroxibutírico , Sales (Química) , Cuerpos Cetónicos , Cetonas , Glucosa , Insulina , Ayuno
8.
Int J Tuberc Lung Dis ; 27(1): 49-54, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36853136

RESUMEN

BACKGROUND: Children under 1 year of age with hypoxic pneumonia regularly have concurrent cytomegalovirus (CMV) viremia. In these children, the diagnosis of CMV-associated pneumonia and the prediction of an outcome are difficult. It is unclear whether quantification of blood CMV viral load (CMV-VL) can predict outcomes in these children.METHODS: This was a retrospective study including children (1-12 months of age), with detectable CMV-VL and hypoxic pneumonia admitted to the paediatric intensive care unit of Tygerberg Hospital, Cape Town, South Africa between 1 January 2014 and 31 December 2015. Clinical, radiological and biochemical data were collected.RESULTS: Of the 87 participants included (median age: 3.9 months, IQR 2.2-4.8), 35 were (40%) born prematurely. The median weight-for-age Z-score was -2.68 (IQR -3.0 to -0.83); 37 (43%) were severely underweight for age; 27 (31%) were HIV-positive, 3 were on ART. The median CMV-VL was log 4.0 (IQR 3.3-4.79); CMVhigh was defined as CMV-VL > median; CMV-VL < median was classified as CMVlow. Overall survival was 90%; 12 (15.4%) remained oxygen-dependent at Day 28 post-admission. There was no difference in survival, 24-h post-admission ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2:FiO2), oxygen dependence or ventilation duration between CMVlow and CMVhigh. High-frequency oscillation ventilation duration was longer (P = 0.005) and Pneumocystis jirovecii (PJP) co-infection more frequent (P = 0.018) in CMVhigh.CONCLUSION: CMV-VL is unable to predict the clinical outcome in children with hypoxic pneumonia. Specific treatment for CMV should be considered in all children at risk of CMV-associated pneumonia with detectable CMV-VL.


Asunto(s)
Infecciones por Citomegalovirus , Neumonía , Niño , Humanos , Lactante , Citomegalovirus , Estudios Retrospectivos , Carga Viral , Sudáfrica/epidemiología , Neumonía/diagnóstico , Oxígeno , Infecciones por Citomegalovirus/diagnóstico , Progresión de la Enfermedad
9.
J Am Nutr Assoc ; 42(2): 169-177, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35512774

RESUMEN

BACKGROUND: Ketosis has been reported to benefit healthspan and resilience, which has driven considerable interest in development of exogenous ketones to induce ketosis without dietary changes. Bis hexanoyl (R)-1,3-butanediol (BH-BD) is a novel ketone di-ester that can be used as a food ingredient that increases hepatic ketogenesis and blood beta-hydroxybutyrate (BHB) concentrations. METHODS: Here, we provide the first description of blood ketone and metabolite kinetics for up to five hours after consumption of a beverage containing BH-BD by healthy adults (n = 8) at rest in three randomized, cross-over conditions (25 g + Meal (FEDH); 12.5 g + Meal (FEDL) ; 25 g + Fasted (FASTH)). RESULTS: Consumption of BH-BD effectively raised plasma r-BHB concentrations to 0.8-1.7 mM in all conditions, and both peak r-BHB concentration and r-BHB area under the curve were greater with 25 g versus 12.5 g of BH-BD. Urinary excretion of r-BHB was <1 g. Plasma concentration of the non-physiological isoform s-BHB was increased to 20-60 µM in all conditions. BH-BD consumption decreased plasma glucose and free fatty acid concentrations; insulin was increased when BH-BD was consumed with a meal. CONCLUSIONS: These results demonstrate that consumption of BH-BD effectively induces exogenous ketosis in healthy adults at rest.


Asunto(s)
Ésteres , Cetosis , Adulto , Humanos , Ácido 3-Hidroxibutírico , Hidroxibutiratos , Cuerpos Cetónicos , Cetonas
10.
Sports Med ; 53(1): 75-89, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36175646

RESUMEN

There are many benefits to the addition of exercise to cancer treatment and survivorship, particularly with resistance training regimens that target hypertrophy, bone mineral density, strength, functional mobility, and body composition. These goals are best achieved through a series of individualized high-intensity compound movements that mirror functional mobility patterns and sufficiently stress the musculoskeletal system. As a result of adequate stress, the body will engage compensatory cellular mechanisms that improve the structural integrity of bones and muscles, stimulate metabolism and the immune system, optimize functional performance, and minimize mechanical injury risk. The current evidence suggests that application of the above exercise principles, practiced in a safe environment under expert observation, may offer patients with cancer an effective means of improving overall health and cancer-specific outcomes. The following article poses several important questions certified exercise specialists and physicians should consider when prescribing resistance exercise for patients with cancer.


Asunto(s)
Neoplasias , Entrenamiento de Fuerza , Humanos , Densidad Ósea , Ejercicio Físico/fisiología , Huesos , Composición Corporal , Fuerza Muscular/fisiología , Neoplasias/terapia
11.
12.
Nutrients ; 14(6)2022 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-35334791

RESUMEN

A growing number of endurance athletes have considered switching from a traditional high-carbohydrate/low-fat (HCLF) to a low-carbohydrate/high-fat (LCHF) eating pattern for health and performance reasons. However, few studies have examined how LCHF diets affect blood lipid profiles in highly-trained runners. In a randomized and counterbalanced, cross-over design, athletes (n = 7 men; VO2max: 61.9 ± 6.1 mL/kg/min) completed six weeks of two, ad libitum, LCHF (6/69/25% en carbohydrate/fat/protein) and HCLF (57/28/15% en carbohydrate/fat/protein) diets, separated by a two-week washout. Plasma was collected on days 4, 14, 28, and 42 during each condition and analyzed for: triglycerides (TG), LDL-C, HDL-C, total cholesterol (TC), VLDL, fasting glucose, and glycated hemoglobin (HbA1c). Capillary blood beta-hydroxybutyrate (BHB) was monitored during LCHF as a measure of ketosis. LCHF lowered plasma TG, VLDL, and TG/HDL-C (all p < 0.01). LCHF increased plasma TC, LDL-C, HDL-C, and TC/HDL-C (all p < 0.05). Plasma glucose and HbA1c were unaffected. Capillary BHB was modestly elevated throughout the LCHF condition (0.5 ± 0.05 mmol/L). Healthy, well-trained, normocholesterolemic runners consuming a LCHF diet demonstrated elevated circulating LDL-C and HDL-C concentrations, while concomitantly decreasing TG, VLDL, and TG/HDL-C ratio. The underlying mechanisms and implications of these adaptive responses in cholesterol should be explored.


Asunto(s)
Dieta con Restricción de Grasas , Carbohidratos de la Dieta , HDL-Colesterol , Estudios Cruzados , Humanos , Lípidos , Masculino
14.
Ultrasound Obstet Gynecol ; 60(1): 132-138, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34919771

RESUMEN

OBJECTIVES: To compare the efficiency, ease of use and user satisfaction of two methods of transvaginal ultrasound probe high-level disinfection: ultraviolet-C radiation (UV-C) and a chlorine dioxide multistep wipe system. METHODS: This was a prospective survey study. UV-C units were introduced into a busy early pregnancy assessment service and compared with a multiwipe system for disinfection. Before seeing each patient, healthcare professionals (HCPs) measured with a stopwatch the time taken to complete a cycle of disinfection using either UV-C or chlorine dioxide multistep wipes and responded to a quick-response (QR) code-linked survey. Additional essential tasks that could be completed before seeing the next patient during probe disinfection were also documented. Using another QR code-linked survey, data on ease of use, satisfaction with the system used and preferred system were collected. The ease of use and satisfaction with the system were rated on a 0 to 10 Likert scale (0 poor, 10 excellent). A free-text section for comments was then completed. RESULTS: Disinfection using UV-C (n = 331) was 60% faster than the chlorine dioxide multiwipe system (n = 332) (101 vs 250 s; P < 0.0001). A greater number of tasks were completed during probe disinfection when using UV-C, saving a further 74 s per patient (P < 0.0001). The HCPs using UV-C (n = 71) reported greater ease of use (median Likert score, 10 vs 3; P < 0.0001) and satisfaction (median Likert score, 10 vs 2; P < 0.0001) compared with those using the multiwipe system (n = 43). HCPs reported that the chlorine dioxide system was time-consuming and environmentally unfriendly, while the UV-C system was efficient and easy to use. Overall, 98% of the HCPs preferred using the UV-C system. CONCLUSIONS: UV-C technology is more time-efficient and allows more essential tasks to be completed during disinfection. For a 4-h ultrasound list of 15 patients, the use of UV-C would save 55 min 45 s. HCPs found UV-C preferable and easier to use. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Compuestos de Cloro , Desinfección , Desinfección/métodos , Humanos , Óxidos , Estudios Prospectivos
15.
Ultrasound Obstet Gynecol ; 58(6): 909-915, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34605083

RESUMEN

OBJECTIVE: To describe and compare the characteristics of ectopic pregnancies (EPs) in the year prior to vs during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This was a retrospective analysis of women diagnosed with an EP on transvaginal sonography conducted at a center in London, UK, providing early-pregnancy assessment, between 1 January 2019 and 31 December 2020. Women were identified via the Astraia ultrasound reporting system using coded and non-coded outcomes of EP or pregnancy outside the uterine cavity. Data related to predefined outcomes were collected using Astraia and Cerner electronic reporting systems. Main outcome measures included clinical, ultrasound and biochemical features of EP, in addition to reported complications and management. RESULTS: There were 22 683 consultations over the 2-year period. Following consultation, a similar number and proportion of EPs were diagnosed in 2019 (141/12 657 (1%)) and 2020 (134/10 026 (1%)). Both cohorts were comparable in age, ethnicity, weight and method of conception. Gestational age at the first transvaginal sonography scan and at diagnosis were similar, and no difference in location, size or morphology of EP was found between the two cohorts. Serum human chorionic gonadotropin (hCG) levels at the time of EP diagnosis were higher in 2020 than in 2019 (1005 IU/L vs 665 IU/L; P = 0.03). The proportions of women according to type of final EP management were similar, but the rate of failed first-line management was higher during vs before the pandemic (16% vs 6%; P = 0.01). The rates of blood detected in the pelvis (hemoperitoneum) on ultrasound (23% vs 26%; P = 0.58) and of ruptured EP confirmed surgically (9% vs 3%; P = 0.07) were similar in 2019 vs 2020. CONCLUSIONS: No difference was observed in the location, size, morphology or gestational age at the first ultrasound examination or at diagnosis of EP between women diagnosed before vs during the COVID-19 pandemic. Complication rates and final management strategy were also unchanged. However, hCG levels and the failure rate of first-line conservative management measures were higher during the pandemic. Our findings suggest that women continued to access appropriate care for EP during the COVID-19 pandemic, with no evidence of diagnostic delay or an increase in adverse outcome in our population. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Embarazo Ectópico/diagnóstico , Atención Prenatal/normas , Adulto , COVID-19/epidemiología , Femenino , Humanos , Londres , Pandemias , Embarazo , Resultado del Embarazo , Embarazo Ectópico/sangre , Embarazo Ectópico/epidemiología , Estudios Retrospectivos , SARS-CoV-2 , Ultrasonografía Prenatal
16.
PLoS One ; 16(8): e0254991, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34347824

RESUMEN

Human pluripotent stem cells (hPSCs) have the potential to differentiate into all cell types, a property known as pluripotency. A deeper understanding of how pluripotency is regulated is required to assist in controlling pluripotency and differentiation trajectories experimentally. Mathematical modelling provides a non-invasive tool through which to explore, characterise and replicate the regulation of pluripotency and the consequences on cell fate. Here we use experimental data of the expression of the pluripotency transcription factor OCT4 in a growing hPSC colony to develop and evaluate mathematical models for temporal pluripotency regulation. We consider fractional Brownian motion and the stochastic logistic equation and explore the effects of both additive and multiplicative noise. We illustrate the use of time-dependent carrying capacities and the introduction of Allee effects to the stochastic logistic equation to describe cell differentiation. We conclude both methods adequately capture the decline in OCT4 upon differentiation, but the Allee effect model has the advantage of allowing differentiation to occur stochastically in a sub-set of cells. This mathematical framework for describing intra-cellular OCT4 regulation can be extended to other transcription factors and developed into predictive models.


Asunto(s)
Espacio Intracelular/metabolismo , Modelos Biológicos , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Células Madre Pluripotentes/metabolismo , Diferenciación Celular , Humanos , Factores de Tiempo
17.
Nutrients ; 13(6)2021 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-34198888

RESUMEN

BACKGROUND: Foods rich in saturated fatty acids (SFAs) have been discouraged by virtue of their cholesterol-raising potential, but this effect is modulated by the food source and background level of carbohydrate. OBJECTIVE: We aimed to compare the consumption of palm stearin (PS) versus butter on circulating cholesterol responses in the setting of both a low-carbohydrate/high-fat (LC/HF) and high-carbohydrate/low-fat (HC/LF) diet in healthy subjects. We also explored effects on plasma lipoprotein particle distribution and fatty acid composition. METHODS: We performed a randomized, controlled-feeding, cross-over study that compared a PS- versus a Butter-based diet in a group of normocholesterolemic, non-obese adults. A controlled canola oil-based 'Run-In' diet preceded the experimental PS and Butter diets. All diets were eucaloric, provided for 3-weeks, and had the same macronutrient distribution but varied in primary fat source (40% of the total fat). The same Run-In and cross-over experiments were done in two separate groups who self-selected to either a LC/HF (n = 12) or a HC/LF (n = 12) diet track. The primary outcomes were low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL)-C, triglycerides, and LDL particle distribution. RESULTS: Compared to PS, Butter resulted in higher LDL-C in both the LC/HF (13.4%, p = 0.003) and HC/LF (10.8%, p = 0.002) groups, which was primarily attributed to large LDL I and LDL IIa particles. There were no differences between PS and Butter in HDL-C, triglycerides, or small LDL particles. Oxidized LDL was lower after PS than Butter in LC/HF (p = 0.011), but not the HC/LF group. CONCLUSIONS: These results demonstrate that Butter raises LDL-C relative to PS in healthy normocholesterolemic adults regardless of background variations in carbohydrate and fat, an effect primarily attributed to larger cholesterol-rich LDL particles.


Asunto(s)
Mantequilla , Colesterol/sangre , Dieta/métodos , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Aceite de Palma/administración & dosificación , Adulto , Anciano , Estudios Cruzados , Dieta/efectos adversos , Dieta de Carga de Carbohidratos/efectos adversos , Dieta de Carga de Carbohidratos/métodos , Dieta Baja en Carbohidratos/efectos adversos , Dieta Baja en Carbohidratos/métodos , Dieta con Restricción de Grasas/efectos adversos , Dieta con Restricción de Grasas/métodos , Dieta Alta en Grasa/efectos adversos , Dieta Alta en Grasa/métodos , Femenino , Voluntarios Sanos , Humanos , Lípidos/sangre , Masculino , Persona de Mediana Edad , Aceite de Palma/química , Adulto Joven
18.
Integr Cancer Ther ; 20: 15347354211032283, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34259084

RESUMEN

Alpelisib is a α-selective phosphatidylinositol 3-kinase (PI3K) inhibitor approved for treatment of postmenopausal women, and men, with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-), PIK3CA-mutated, advanced breast cancer (ABC). Hyperglycemia is a common, on-target adverse effect that impairs treatment efficacy and increases the rate of treatment delays, dose reductions, and discontinuation. Currently, there are no clear guidelines on how to manage hyperglycemia due to alpelisib when metformin is not effective. In this case series, we review 3 subjects with ABC that developed hyperglycemia during alpelisib-fulvestrant therapy and were successfully managed with dietary and pharmacologic interventions. These cases provide anecdotal evidence to support the use of sodium-glucose co-transporter-2 inhibitors (SGLT2i) and very low carbohydrate diets to minimize hyperglycemia during alpelisib therapy.


Asunto(s)
Hiperglucemia , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Simportadores , Dieta Baja en Carbohidratos , Femenino , Glucosa , Humanos , Hiperglucemia/inducido químicamente , Hiperglucemia/tratamiento farmacológico , Masculino , Fosfatidilinositol 3-Quinasas , Receptor ErbB-2/metabolismo , Sodio , Tiazoles
19.
Nutrients ; 13(3)2021 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-33802651

RESUMEN

Ketogenic diets (KDs) often contain high levels of saturated fat, which may increase liver fat, but the lower carbohydrate intake may have the opposite effect. Using a controlled feeding design, we compared liver fat responses to a hypocaloric KD with a placebo (PL) versus an energy-matched low-fat diet (LFD) in overweight adults. We also examined the added effect of a ketone supplement (KS). Overweight adults were randomized to a 6-week KD (KD + PL) or a KD with KS (KD + KS); an LFD group was recruited separately. All diets were estimated to provide 75% of energy expenditure. Weight loss was similar between groups (p > 0.05). Liver fat assessed by magnetic resonance imaging decreased after 6 week (p = 0.004) with no group differences (p > 0.05). A subset with nonalcoholic fatty liver disease (NAFLD) (liver fat > 5%, n = 12) showed a greater reduction in liver fat, but no group differences. In KD participants with NAFLD, 92% of the variability in change in liver fat was explained by baseline liver fat (p < 0.001). A short-term hypocaloric KD high in saturated fat does not adversely impact liver health and is not impacted by exogenous ketones. Hypocaloric low-fat and KDs can both be used in the short-term to significantly reduce liver fat in individuals with NAFLD.


Asunto(s)
Dieta con Restricción de Grasas , Dieta Cetogénica , Suplementos Dietéticos , Grasas/análisis , Cetonas/uso terapéutico , Hígado/química , Sobrepeso/dietoterapia , Adulto , Dieta con Restricción de Grasas/métodos , Dieta Cetogénica/métodos , Grasas/metabolismo , Femenino , Humanos , Hígado/diagnóstico por imagen , Hígado/metabolismo , Imagen por Resonancia Magnética , Masculino , Sobrepeso/metabolismo
20.
Front Nutr ; 8: 618520, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33869263

RESUMEN

Background: Ketogenic diets (KDs) that elevate beta-hydroxybutyrate (BHB) promote weight and fat loss. Exogenous ketones, such as ketone salts (KS), also elevate BHB concentrations with the potential to protect against muscle loss during caloric restriction. Whether augmenting ketosis with KS impacts body composition responses to a well-formulated KD remains unknown. Purpose: To explore the effects of energy-matched, hypocaloric KD feeding (<50 g carbohydrates/day; 1.5 g/kg/day protein), with and without the inclusion of KS, on weight loss and body composition responses. Methods: Overweight and obese adults were provided a precisely defined hypocaloric KD (~75% of energy expenditure) for 6 weeks. In a double-blind manner, subjects were randomly assigned to receive ~24 g/day of a racemic BHB-salt (KD + KS; n = 12) or placebo (KD + PL; n = 13). A matched comparison group (n = 12) was separately assigned to an isoenergetic/isonitrogenous low-fat diet (LFD). Body composition parameters were assessed by dual x-ray absorptiometry and magnetic resonance imaging. Results: The KD induced nutritional ketosis (>1.0 mM capillary BHB) throughout the study (p < 0.001), with higher fasting concentrations observed in KD + KS than KD + PL for the first 2 weeks (p < 0.05). There were decreases in body mass, whole body fat and lean mass, mid-thigh muscle cross-sectional area, and both visceral and subcutaneous adipose tissues (p < 0.001), but no group differences between the two KDs or with the LFD. Urine nitrogen excretion was significantly higher in KD + PL than LFD (p < 0.01) and trended higher in KD + PL compared to KD + KS (p = 0.076), whereas the nitrogen excretion during KD + KS was similar to LFD (p > 0.05). Conclusion: Energy-matched hypocaloric ketogenic diets favorably affected body composition but were not further impacted by administration of an exogenous BHB-salt that augmented ketosis. The trend for less nitrogen loss with the BHB-salt, if manifested over a longer period of time, may contribute to preserved lean mass.

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