Probabilistic analysis of spatial viscoelastic cues in 3D cell culture using magnetic microrheometry.

Breast tumors are typically surrounded by extracellular matrix (ECM), which is heterogeneous, not just structurally but also mechanically. Conventional rheometry is inadequate for describing cell-size-level spatial differences in ECM mechanics that are evident at micrometer scales. Optical tweezers and passive microrheometry provide a microscale resolution for the purpose but are incapable of measuring ECM viscoelasticity (the liquid-like viscous and solid-like elastic characteristics) at stiffness levels as found in breast tumor biopsies.

Measuring mechanical cues for modeling the stromal matrix in 3D cell cultures.

A breast-cancer tumor develops within a stroma, a tissue where a complex extracellular matrix surrounds cells, mediating the cancer progression through biomechanical and -chemical cues. Current materials partially mimic the stromal matrix in 3D cell cultures but methods for measuring the mechanical properties of the matrix at cell-relevant-length scales and stromal-stiffness levels are lacking. Here, to address this gap, we developed a characterization approach that employs probe-based microrheometry and Bayesian modeling to quantify length-scale-dependent mechanics and mechanical heterogeneity as in the stromal matrix.

Quantifying the Influence of X-Ray Irradiation on Cell-Size-Scale Viscoelasticity of Collagen Type 1.

X-rays are widely used in mammography and radiotherapy of breast cancer. The research has focused on the effects of X-rays on cells in breast tissues, instead of the tissues' nonliving material, extracellular matrix. It is unclear what the influence of X-ray irradiation is on the matrix's mechanical cues, known to regulate malignant cancer-cell behaviors.

Fibrin Stiffness Regulates Phenotypic Plasticity of Metastatic Breast Cancer Cells.

The extracellular matrix (ECM)-regulated phenotypic plasticity is crucial for metastatic progression of triple negative breast cancer (TNBC). While ECM faithful cell-based models are available for in situ and invasive tumors, such as cell aggregate cultures in reconstituted basement membrane and in collagenous gels, there are no ECM faithful models for metastatic circulating tumor cells (CTCs). Such models are essential to represent the stage of metastasis where clinical relevance and therapeutic opportunities are significant.

Magnetic microrheometry of tumor-relevant stiffness levels and probabilistic quantification of viscoelasticity differences inside 3D cell culture matrices.

The progression of breast cancer involves cancer-cell invasions of extracellular matrices. To investigate the progression, 3D cell cultures are widely used along with different types of matrices. Currently, the matrices are often characterized using parallel-plate rheometry for matrix viscoelasticity, or liquid-like viscous and stiffness-related elastic characteristics.

Characterizing Aptamers with Reconfigurable Chiral Plasmonic Assemblies.

Aptamers have emerged as versatile affinity ligands and as promising alternatives to protein antibodies. However, the inconsistency in the reported affinities and specificities of aptamers has greatly hindered the development of aptamer-based applications. Herein, we present a strategy to characterize aptamers by using DNA origami-based chiral plasmonic assemblies as reporters and establishing a competitive hybridization reaction-based thermodynamic model.

Light-Responsive Dynamic DNA-Origami-Based Plasmonic Assemblies.

DNA nanotechnology offers a versatile toolbox for precise spatial and temporal manipulation of matter on the nanoscale. However, rendering DNA-based systems responsive to light has remained challenging. Herein, we describe the remote manipulation of native (non-photoresponsive) chiral plasmonic molecules (CPMs) using light.

Association between self-reported hypertension onset age and electrocardiographic left ventricular hypertrophy.

Objectively defined early-onset hypertension, based on repeated blood pressure measurements, is associated with greater odds of organ damage and cardiovascular mortality than late-onset hypertension. In this study we examined the association between two factors that are easily available in primary care, self-reported hypertension onset age and electrocardiographic left ventricular hypertrophy (ECG-LVH), in a nationwide population sample of 2864 Finns aged ≥50 years. We observed that, in contrast to prior findings, the odds of ECG-LVH were similar between self-reported hypertension onset age groups, and thus self-reported early-onset hypertension does not seem to associate with ECG-LVH more strongly than simple presence of hypertension.

Early Onset Hypertension Is Associated With Hypertensive End-Organ Damage Already by MidLife.

Early onset hypertension confers increased risk for cardiovascular mortality in the community. Whether early onset hypertension also promotes the development of target end-organ damage (TOD), even by midlife, has remained unknown. We studied 2680 middle-aged CARDIA study (Coronary Artery Risk Development in Young Adults) Study participants (mean age 50±4 years, 57% women) who underwent up to 8 serial blood pressure measurements between 1985 and 2011 (age range at baseline 18-30 years) in addition to assessments of echocardiographic left ventricular hypertrophy, coronary calcification, albuminuria, and diastolic dysfunction in 2010 to 2011.

Electrocardiographic predictors of atrial fibrillation in nonhypertensive and hypertensive individuals.

Objective: The aim of this study was to compare the predictive value of ECG abnormalities for atrial fibrillation in nonhypertensive versus hypertensive individuals.

Methods: We recorded ECG and measured conventional cardiovascular risk factors in a nationwide population-based sample of 5813 Finns. We divided the participants into nonhypertensive (n = 3148) and hypertensive (n = 2665) individuals and followed the participants for incident atrial fibrillation events.

Thyroid-stimulating hormone and risk of sudden cardiac death, total mortality and cardiovascular morbidity.

Background: Previous data on the association of thyroid function with total mortality, cardiovascular disease (CVD) outcomes and sudden cardiac death (SCD) are conflicting or limited. We investigated associations of thyroid-stimulating hormone (TSH) with these outcomes in a nationwide population-based prospective cohort study.

Methods: We examined 5211 participants representative of the Finnish population aged ≥30 years in 2000-2001 and followed them for a median of 13.

Incidence rates, correlates, and prognosis of electrocardiographic P-wave abnormalities - a nationwide population-based study.

Background: Scant data exist on incidence rates, correlates, and prognosis of electrocardiographic P-wave abnormalities in the general population.

Methods: We recorded ECG and measured conventional cardiovascular risk factors in 5667 Finns who were followed up for incident atrial fibrillation (AF). We obtained repeat ECGs from 3089 individuals 11years later.

Prevalence and prognosis of ECG abnormalities in normotensive and hypertensive individuals.

Objective: To define the prevalence and prognosis of ECG abnormalities in hypertensive individuals.

Methods: ECG, blood pressure and other cardiovascular risk factors were recorded in a nationwide population sample of 5800 Finns. The presence of 15 ECG abnormalities was evaluated.