Polygenic risk scores (PRSs) can be used to predict ischemic stroke (IS). However, further validation of PRS performance is required in independent populations, particularly older adults in whom the ...majority of strokes occur.
We predicted risk of incident IS events in a population of 12 792 healthy older individuals enrolled in the ASPREE trial (Aspirin in Reducing Events in the Elderly). The PRS was calculated using 3.6 million genetic variants. Participants had no previous history of cardiovascular events, dementia, or persistent physical disability at enrollment. The primary outcome was IS over 5 years, with stroke subtypes as secondary outcomes. A multivariable model including conventional risk factors was applied and reevaluated after adding PRS. Area under the curve and net reclassification were evaluated.
At baseline, mean population age was 75 years. In total, 173 incident IS events occurred over a median follow-up of 4.7 years. When PRS was added to the multivariable model as a continuous variable, it was independently associated with IS (hazard ratio, 1.41 95% CI, 1.20–1.65 per SD of the PRS; P<0.001). The PRS alone was a better discriminator for IS events than most conventional risk factors. PRS as a categorical variable was a significant predictor in the highest tertile (hazard ratio, 1.74; P=0.004) compared with the lowest. The area under the curve of the conventional model was 66.6% (95% CI, 62.2–71.1) and after inclusion of the PRS, improved to 68.5 (95% CI, 64.0–73.0 P=0.095). In subgroup analysis, the continuous PRS remained an independent predictor for large vessel and cardioembolic stroke subtypes but not for small vessel stroke. Reclassification was improved, as the continuous net reclassification index after adding PRS to the conventional model was 0.25 (95% CI, 0.17–0.43).
PRS predicts incident IS in a healthy older population but only moderately improves prediction over conventional risk factors.
URL: https://www.clinicaltrials.gov; Unique identifier: NCT01038583.
High office blood pressure variability (OBPV) in midlife increases the risk of cardiovascular disease (CVD), but the impact of OBPV in older adults without previous CVD is unknown. We conducted a ...post hoc analysis of ASPREE trial (Aspirin in Reducing Events in the Elderly) participants aged 70-years and older (65 for US minorities) without history of CVD events at baseline, to examine risk of incident CVD associated with long-term, visit-to-visit OBPV. CVD was a prespecified, adjudicated secondary end point in ASPREE. We estimated OBPV using within-individual SD of mean systolic BP from baseline and first 2 annual visits. Cox proportional hazards regression was used to calculate hazard ratios (HR) and 95% CI for associations with CVD events. In 16 475 participants who survived to year 2 without events, those in the highest tertile of OBPV had increased risk of CVD events after adjustment for multiple covariates, when compared with participants in the lowest tertile (HR, 1.36 95% CI, 1.08-1.70;
=0.01). Similar increased risk was observed for ischemic stroke (HR, 1.56 95% CI, 1.04-2.33;
=0.03), heart failure hospitalization, or death (HR, 1.73 95% CI, 1.07-2.79;
=0.02), and all-cause mortality (HR, 1.27 95% CI, 1.04-1.54;
=0.02). Findings were consistent when stratifying participants by use of antihypertensive drugs, while sensitivity analyses suggested the increased risk was especially for individuals whose BP was uncontrolled during the OBPV estimation period. Our findings support increased OBPV as a risk factor for CVD events in healthy older adults with, or without hypertension, who have not had such events previously. Registration- URL: https://www.clinicaltrials.gov; Unique identifiers: NCT01038583; URL: https://www.isrctn.com; Unique identifiers: ISRCTN83772183.
Laser powder bed fusion (LPBF) is a method of additive manufacturing characterized by the rapid scanning of a high powered laser over a thin bed of metallic powder to create a single layer, which may ...then be built upon to form larger structures. Much of the melting, resolidification, and subsequent cooling take place at much higher rates and with much higher thermal gradients than in traditional metallurgical processes, with much of this occurring below the surface. We have used in situ high speed X-ray diffraction to extract subsurface cooling rates following resolidification from the melt and above the β-transus in titanium alloy Ti-6Al-4V. We observe an inverse relationship with laser power and bulk cooling rates. The measured cooling rates are seen to correlate to the level of residual strain borne by the minority β-Ti phase with increased strain at slower cooling rates. The α-Ti phase shows a lattice contraction which is invariant with cooling rate. We also observe a broadening of the diffraction peaks which is greater for the β-Ti phase at slower cooling rates and a change in the relative phase fraction following LPBF. These results provide a direct measure of the subsurface thermal history and demonstrate its importance to the ultimate quality of additively manufactured materials.
To control the process of cation exchange (CE) in a multielemental system, a detailed understanding of structural changes at the microscopic level is imperative. However, the synthesis of a ...multielemental system has so far relied on the CE phenomenon of a binary system, which does not necessarily extend to the higher-order systems. Here, direct experimental evidence supported by theoretical calculations reveals a growth model of binary Cu–S to ternary Cu–Sn–S to quaternary Cu–Zn–Sn–S, which shows that cations preferentially diffuse along a specific lattice plane with the preservation of sulfuric anionic framework. In addition, we also discover that, unlike the commonly accepted structure (P63 mc), the metastable crystal structure of Cu–Zn–Sn–S phase possesses fixed Sn occupancy sites. By revealing the preferential nature of cations diffusion and growth mechanism, our work provides insight into controlling the stoichiometry and phase purity of novel multielemental materials.
Obesity leads to an increased risk for type 2 diabetes, heart disease, stroke, and cancer. The causal link between obesity and these pathologies has recently been identified as chronic low-grade ...systemic inflammation initiated by pro-inflammatory macrophages in visceral adipose tissue. Current medications based on small-molecule drugs yield significant off-target side effects with long-term use, and therefore there is a major need for targeted therapies. Here we report that nanoscale polysaccharides based on biocompatible glucose polymers can efficiently target adipose macrophages in obese mice. We synthesized a series of dextran conjugates with tunable size linked to contrast agents for positron emission tomography, fluorophores for optical microscopy, and anti-inflammatory drugs for therapeutic modulation of macrophage phenotype. We observed that larger conjugates efficiently distribute to visceral adipose tissue and selectively associate with macrophages after regional peritoneal administration. Up to 63% of the injected dose remained in visceral adipose tissue 24 h after administration, resulting in >2-fold higher local concentration compared to liver, the dominant site of uptake for most nanomedicines. Furthermore, a single-dose treatment of anti-inflammatory conjugates significantly reduced pro-inflammatory markers in adipose tissue of obese mice. Importantly, all components of these therapeutic agents are approved for clinical use. This work provides a promising nanomaterials-based delivery strategy to inhibit critical factors leading to obesity comorbidities and demonstrates a unique transport mechanism for drug delivery to visceral tissues. This approach may be further applied for high-efficiency targeting of other inflammatory diseases of visceral organs.
In the general population, body mass index (BMI) and waist circumference are recognized risk factors for several chronic diseases and all-cause mortality. However, whether these associations are the ...same for older adults is less clear. The association of baseline BMI and waist circumference with all-cause and cause-specific mortality was investigated in 18,209 Australian and US participants (mean age: 75.1 ± 4.5 years) from the ASPirin in Reducing Events in the Elderly (ASPREE) study, followed up for a median of 6.9 years (IQR: 5.7, 8.0). There were substantially different relationships observed in men and women. In men, the lowest risk of all-cause and cardiovascular mortality was observed with a BMI in the range 25.0-29.9 kg/m
HR
: 0.85; 95% CI, 0.73-1.00 while the highest risk was in those who were underweight HR
: 1.82; 95% CI 1.30-2.55, leading to a clear U-shaped relationship. In women, all-cause mortality was highest in those with the lowest BMI leading to a J-shaped relationship (HR
: 1.64; 95% CI 1.26-2.14). Waist circumference showed a weaker relationship with all-cause mortality in both men and women. There was little evidence of a relationship between either index of body size and subsequent cancer mortality in men or women, while non-cardiovascular non-cancer mortality was higher in underweight participants. For older men, being overweight was found to be associated with a lower risk of all-cause mortality, while among both men and women, a BMI in the underweight category was associated with a higher risk. Waist circumference alone had little association with all-cause or cause-specific mortality risk.Trial registration ASPREE https://ClinicalTrials.gov number NCT01038583.
Filter-aided sample preparation is a proteomic technique for the preparation and on column proteolysis of proteins. Recently an enhanced FASP protocol was developed that uses deoxycholic acid (DCA) ...and that reportedly enhances trypsin proteolysis, resulting in increases cytosolic and membrane protein representation. FASP and eFASP were re-evaluated by ultra-high-performance liquid chromatography coupled to a quadrupole mass filter Orbitrap analyzer (Q Exactive). Although there was no difference in trypsin activity, 14 099 and 13 414 peptides, describing 1723 and 1793 protein groups, from Escherichia coli K12 were identified using FASP and eFASP, respectively. Characterization of the physicochemical properties of identified peptides showed no significant differences other than eFASP extracting slightly more basic peptides. At the protein level, both methods extracted essentially the same number of hydrophobic transmembrane helix-containing proteins as well as proteins associated with the cytoplasm or the cytoplasmic and outer membranes. By employing state-of-the-art LC–MS/MS shot gun proteomics, our results indicate that FASP and eFASP showed no significant differences at the protein level. However, because of the slight differences in selectivity at the physicochemical level of peptides, these methods can be seen to be somewhat complementary for analyses of complex peptide mixtures.
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