Exploration of PET and MRI radiomic features for decoding breast cancer phenotypes and prognosis.

Radiomics is an emerging technology for imaging biomarker discovery and disease-specific personalized treatment management. This paper aims to determine the benefit of using multi-modality radiomics data from PET and MR images in the characterization breast cancer phenotype and prognosis. Eighty-four features were extracted from PET and MR images of 113 breast cancer patients. Unsupervised clustering based on PET and MRI radiomic features created three subgroups. These derived subgroups were statistically significantly associated with tumor grade (p = 2.0 × 10-6), tumor overall stage (p = 0.037), breast cancer subtypes (p = 0.0085), and disease recurrence status (p = 0.0053). The PET-derived first-order statistics and gray level co-occurrence matrix (GLCM) textural features were discriminative of breast cancer tumor grade, which was confirmed by the results of L2-regularization logistic regression (with repeated nested cross-validation) with an estimated area under the receiver operating characteristic curve (AUC) of 0.76 (95% confidence interval (CI) = [0.62, 0.83]). The results of ElasticNet logistic regression indicated that PET and MR radiomics distinguished recurrence-free survival, with a mean AUC of 0.75 (95% CI = [0.62, 0.88]) and 0.68 (95% CI = [0.58, 0.81]) for 1 and 2 years, respectively. The MRI-derived GLCM inverse difference moment normalized (IDMN) and the PET-derived GLCM cluster prominence were among the key features in the predictive models for recurrence-free survival. In conclusion, radiomic features from PET and MR images could be helpful in deciphering breast cancer phenotypes and may have potential as imaging biomarkers for prediction of breast cancer recurrence-free survival

Folding transition of the triangular lattice in a discrete three--dimensional space

A vertex model introduced by M. Bowick, P. Di Francesco, O. Golinelli, and E. Guitter (cond-mat/9502063) describing the folding of the triangular lattice onto the face centered cubic lattice has been studied in the hexagon approximation of the cluster variation method. The model describes the behaviour of a polymerized membrane in a discrete three--dimensional space. We have introduced a curvature energy and a symmetry breaking field and studied the phase diagram of the resulting model. By varying the curvature energy parameter, a first-order transition has been found between a flat and a folded phase for any value of the symmetry breaking field.Comment: 11 pages, latex file, 2 postscript figure

First-order transition of tethered membranes in 3d space

We study a model of phantom tethered membranes, embedded in three-dimensional space, by extensive Monte Carlo simulations. The membranes have hexagonal lattice structure where each monomer is interacting with six nearest-neighbors (NN). Tethering interaction between NN, as well as curvature penalty between NN triangles are taken into account. This model is new in the sense that NN interactions are taken into account by a truncated Lennard-Jones potential including both repulsive and attractive parts. The main result of our study is that the system undergoes a first-order crumpling transition from low temperature flat phase to high temperature crumpled phase, in contrast with early numerical results on models of tethered membranes.Comment: 5 pages, 6 figure

Folding transitions of the triangular lattice with defects

A recently introduced model describing the folding of the triangular lattice is generalized allowing for defects in the lattice and written as an Ising model with nearest-neighbor and plaquette interactions on the honeycomb lattice. Its phase diagram is determined in the hexagon approximation of the cluster variation method and the crossover from the pure Ising to the pure folding model is investigated, obtaining a quite rich structure with several multicritical points. Our results are in very good agreement with the available exact ones and extend a previous transfer matrix study.Comment: 16 pages, latex, 5 postscript figure

Folding of the Triangular Lattice with Quenched Random Bending Rigidity

We study the problem of folding of the regular triangular lattice in the presence of a quenched random bending rigidity + or - K and a magnetic field h (conjugate to the local normal vectors to the triangles). The randomness in the bending energy can be understood as arising from a prior marking of the lattice with quenched creases on which folds are favored. We consider three types of quenched randomness: (1) a ``physical'' randomness where the creases arise from some prior random folding; (2) a Mattis-like randomness where creases are domain walls of some quenched spin system; (3) an Edwards-Anderson-like randomness where the bending energy is + or - K at random independently on each bond. The corresponding (K,h) phase diagrams are determined in the hexagon approximation of the cluster variation method. Depending on the type of randomness, the system shows essentially different behaviors.Comment: uses harvmac (l), epsf, 17 figs included, uuencoded, tar compresse

Epidemiology of Sarcopenia and Frailty

Sarcopenia and frailty are common in older persons and pose particular challenges for health and social care systems especially in the context of global population ageing. Sarcopenia, the loss of skeletal muscle mass, strength and function with age is associated with adverse individual physical and metabolic changes contributing to morbidity and mortality. The health and socioeconomic implications of sarcopenia are also considerable. Sarcopenia is a core component of physical frailty that together impact negatively on an individual’s capability to live independently. Frailty is a biological syndrome of low reserve and resistance to stressors resulting from cumulative declines across multiple physiological systems that collectively predispose an individual to adverse outcomes. Frailty develops along a continuum from independence through to death as physiological reserves progressively diminish an individual’s capacity to recover from an acute insult or illness. Managing sarcopenia and frailty involves the multidisciplinary led completion of a comprehensive care plan that is patient centred, responsive to the needs of the patient and adaptable therefore enabling an individual to maintain their independence

Mortality, bone density and grip strength: lessons from the past and hope for the future?

Lay Summary: What does this mean for patients? Low grip strength is important in the diagnosis of sarcopenia (loss of muscle mass and strength with age) and low bone density is used to define osteoporosis. Both sarcopenia and osteoporosis are common conditions among older people and are related to increased risk of poor health. In this study we examined grip strength and bone density in relation to the risk of death using data from older UK men and women from the Hertfordshire Cohort Study (aged 59–73 years at the start of the study). Lower grip strength was related to an increased risk of death (any cause) and death due to cardiovascular causes. In contrast, the relationships between bone density and risk of death (any cause) and death due to cardiovascular causes were weak. Relationships between muscle strength and risk of death were much stronger than the relationships between bone density and risk of death. This may reflect better treatment of low bone density, compared with low muscle strength, in this group of older people. This suggests that advances in the treatment of low muscle strength are required

Using routine health care data to develop and validate a system dynamics simulation model of frailty trajectories in an ageing population.

Frailty is common in older adults and has a substantial impact on patient outcomes and service use. Information to support service planning, including prevalence in middle-aged adults and patterns of frailty progression at population level, is scarce. This paper presents a system dynamics model describing the dynamics of frailty and ageing within a population of patients aged ≥50, based on linked data for 2.2 million patients from primary care practices in England. The purpose of the model is to estimate the incidence and prevalence of frailty in an ageing population over time. The model was developed in consultation with stakeholders (patients, carers, clinicians, and commissioners) and validated against another large dataset (1.38 million patients) from Wales. It was then scaled up to the population of England, using Office for National Statistics projections (to 2027). The baseline results, subject to the assumption that the frailty transition parameters remain constant over this period, suggest that the number of people living with frailty will increase as the population ages, and that those with mild-moderate frailty are likely to have the greatest impact on demand. This paper focuses on model development and validation, highlighting the benefits and challenges of using large routine health datasets

The Effect of Nicotinamide Mononucleotide and Riboside on Skeletal Muscle Mass and Function: A Systematic Review and Meta-Analysis.

IntroductionSarcopenia is associated with the loss of skeletal muscle function and mass. Nicotinamide precursors, such as nicotinamide mononucleotide (NMN) and nicotinamide riboside (NR), have received attention for their potential to improve NAD+ levels and mitigate age-related sarcopenia in preliminary models, though evidence on their effects in older adults remains inconclusive.MethodsWe searched PubMed, Cochrane Library, Web of Science, and Scopus to identify randomized controlled trials (RCTs), comparing NR or NMN vs. placebo. A random-effects meta-analysis was employed to determine their impact on measures of sarcopenia such as skeletal muscle index (SMI), handgrip strength (HGS) and gait speed. A narrative synthesis was used for 5-time chair stand test (5CST), short physical performance battery (SPPB), timed-up-and-go (TUG), 6-min walking distance (6MWD), leg and chest press 80% 1RM (repetition maximum) and thigh muscle mass.ResultsIncluded participants had a mean age range from 60.9 to 83 years. NMN supplementation showed no significant effects on SMI (n = 3; mean difference (MD): -0.42, 95% confidence interval (CI): -0.99 - 0.14, I2 = 63%, p = 0.14), HGS (One study estimating left grip; n = 5; MD: 0.61, 95%CI: -0.89 - 2.10, I2 = 0%, p = 0.42; One study estimating right grip; n = 5; MD: 0.45, 95%CI: -1.06 - 1.96, I2 = 0%, p = 0.56), gait speed (n = 4; MD: -0.01, 95%CI: -0.08 - 0.06, I2 = 0%, p = 0.79), or 5CST (n = 2; MD: -0.21, 95%CI: -0.70 - 0.29, I2 = 11%, p = 0.41). Additionally, our narrative synthesis showed that NMN did not improve knee extension strength, SPPB, or thigh muscle mass. NR supplementation was associated with a longer 6MWD among individuals with peripheral artery disease. However, lower scores in the SPPB and slower 5CST were observed in those with mild cognitive impairment.ConclusionsCurrent evidence does not support NMN and NR supplementation for preserving muscle mass and function in adults with mean age of over 60 years. Future research should explore supplementation dosage, NAD+ baseline deficiency, and combined interventions