Associations between Genetic Variants and Blood Biomarkers of One-Carbon Metabolism in Postmenopausal Women from the Women's Health Initiative Observational Study.

BACKGROUND: Genetic variation in one-carbon metabolism may affect nutrient concentrations and biological functions. However, data on genetic variants associated with blood biomarkers of one-carbon metabolism in US postmenopausal women are limited, and whether these associations were affected by the nationwide folic acid (FA) fortification program is unclear. OBJECTIVES: We investigated associations between genetic variants and biomarkers of one-carbon metabolism using data from the Women's Health Initiative Observational Study. METHODS: In 1573 non-Hispanic White (NHW) and 282 Black/African American, American Indian/Alaska Native, Asian/Pacific Islander, and Hispanic/Latino women aged 50-79 y, 288 nonsynonymous and tagging single-nucleotide variants (SNVs) were genotyped. RBC folate, plasma folate, pyridoxal-5'-phosphate (PLP), vitamin B-12, homocysteine, and cysteine concentrations were determined in 12-h fasting blood. Multivariable linear regression tested associations per variant allele and for an aggregated genetic risk score. Effect modifications before, during, and after nationwide FA fortification were examined. RESULTS: After correction for multiple comparisons, among NHW women, 5,10-methylenetetrahydrofolate reductase (MTHFR) rs1801133 (677C→T) variant T was associated with lower plasma folate (-13.0%; 95% CI: -17.3%, -8.6%) and higher plasma homocysteine (3.5%; 95% CI: 1.7%, 5.3%) concentrations. Other associations for nonsynonymous SNVs included DNMT3A rs11695471 (T→A) with plasma PLP; EHMT2 rs535586 (G→A), TCN2 rs1131603 (L349S A→G), and TCN2 rs35838082 (R188W G→A) with plasma vitamin B-12; CBS rs2851391 (G→A) with plasma homocysteine; and MTHFD1 rs2236224 (G→A) and rs2236225 (R653Q G→A) with plasma cysteine. The influence of FA fortification on the associations was limited. Highest compared with lowest quartiles of aggregated genetic risk scores from SNVs in MTHFR and MTRR were associated with 14.8% to 18.9% lower RBC folate concentrations. Gene-biomarker associations were similar in women of other races/ethnicities. CONCLUSIONS: Our findings on genetic variants associated with several one-carbon metabolism biomarkers may help elucidate mechanisms of maintaining B vitamin status in postmenopausal women.

Associations between Plasma Choline Metabolites and Genetic Polymorphisms in One-Carbon Metabolism in Postmenopausal Women: The Women's Health Initiative Observational Study.

BACKGROUND: Choline plays an integral role in one-carbon metabolism in the body, but it is unclear whether genetic polymorphisms are associated with variations in plasma choline and its metabolites. OBJECTIVES: This study aimed to evaluate the association of genetic variants in choline and one-carbon metabolism with plasma choline and its metabolites. METHODS: We analyzed data from 1423 postmenopausal women in a case-control study nested within the Women's Health Initiative Observational Study. Plasma concentrations of choline, betaine, dimethylglycine (DMG), and trimethylamine N-oxide were determined in 12-h fasting blood samples collected at baseline (1993-1998). Candidate and tagging single-nucleotide polymorphisms (SNPs) were genotyped in betaine-homocysteine S-methyltransferase (BHMT), BHMT2, 5,10-methylenetetrahydrofolate reductase (MTHFR), methylenetetrahydrofolate dehydrogenase (NADP+ dependent 1) (MTHFD1), 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR), and 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR). Linear regression was used to derive percentage difference in plasma concentrations per variant allele, adjusting for confounders, including B-vitamin biomarkers. Potential effect modification by plasma vitamin B-12, vitamin B-6, and folate concentrations and folic-acid fortification periods was examined. RESULTS: The candidate SNP BHMT R239Q (rs3733890) was associated with lower concentrations of plasma betaine and DMG concentrations (-4.00% and -6.75% per variant allele, respectively; both nominal P < 0.05). Another candidate SNP, BHMT2 rs626105 A>G, was associated with higher plasma DMG concentration (13.0%; P < 0.0001). Several tagSNPs in these 2 genes were associated with plasma concentrations after correction for multiple comparisons. Vitamin B-12 status was a significant effect modifier of the association between the genetic variant BHMT2 rs626105 A>G and plasma DMG concentration. CONCLUSIONS: Genetic variations in metabolic enzymes were associated with plasma concentrations of choline and its metabolites. Our findings contribute to the knowledge on the variation in blood nutrient concentrations in postmenopausal women.

Preclinical evaluation of the ANCD thrombectomy device: safety and efficacy in a swine clot model.

BACKGROUND: The Advanced Thrombectomy System (ANCD) provides a new funnel component designed to reduce clot fragmentation and facilitate retrieval in patients with stroke by locally restricting flow, allowing distal aspiration in combination with a stent retriever (SR). OBJECTIVE: To evaluate the preclinical efficacy and safety of the ANCD in a swine clot model. METHODS: Soft and firm clots were implanted in the lingual and cervical arteries of 11 swine to obtain Thrombolysis in Cerebral Infarction (TICI) 0 blood flow. Mechanical thrombectomy was performed with either a balloon guide catheter+Solitaire 2 stent retriever (BGC+SR, n=13) or ANCD+SR (n=13). TICI flow was evaluated and successful revascularization was defined as TICI 3 (normal perfusion). To characterize safety, a total of 3 passes were performed in each vessel independent of recanalization. Tissues were explanted for histopathological analysis after 3 and 30 days, respectively. RESULTS: First pass reperfusion rates were ANCD+SR: 69% and BGC+SR: 46%. Reperfusion increased after the third pass in both groups (ANCD+SR: 100%, vs BGC+SR: 77%). Recanalization was achieved after an average of 1.4 and 1.9 passes in ANCD+SR and BGC+SR (p=0.095), respectively. Vessel injury was comparable in both groups; endothelial loss at 3 days was the most common injury seen (ANCD+SR: 1.78±1.22; BGC+SR: 2.03±1.20; p=0.73), while other histopathological markers were absent or minimal. Tissues downstream from targeted vessels also showed absence or minimal lesions across both groups. CONCLUSIONS: Results in a swine clot model support the high efficacy of the ANCD+SR without causing clinically significant vessel injury potentially related to the new funnel component.

Fracture in drug-eluting stents increases focal intimal hyperplasia in the atherosclerosed rabbit iliac artery.

OBJECTIVES: Drug-eluting stent (DES) strut fracture (SF) is associated with higher incidence of In-stent restenosis (ISR)-return of blockage in a diseased artery post stenting-than seen with bare metal stents (BMS). We hypothesize that concomitance of drug and SF leads to greater neointimal response. BACKGROUND: Controlled release of therapeutic agents, such as sirolimus and its analogs, or paclitaxel from has reduced tissue based DES failure modes compared to BMS. ISR is dramatically reduced and yet the implications of mechanical device failure is magnified. METHODS: Bilateral Xience Everolimus-eluting stents (EES) were implanted in 20 New Zealand White rabbits on normal (n = 7) or high fat (HF)/high cholesterol (HC) (n = 13) diets. Implanted stents were intact or mechanically fractured. Everolimus concentration was as packaged or pre-eluted. After 21 days, stented vessels were explanted, resin embedded, MicroCT scanned, and analyzed histomorphometrically. RESULTS: Fractured EES were associated with significant (P < 0.05) increases in arterial stenosis and neointimal formation and lower lumen-to-artery area ratios compared to intact EES. Hyperlipidemic animals receiving pre-eluted EES revealed no significant difference between intact and fracture groups. CONCLUSIONS: SF increases intimal hyperplasia, post EES implant, and worse with more advanced disease. Pre-eluted groups, reflective of BMS, did not show significant differences, suggesting a synergistic effect of everolimus and mechanical injury, potentially explaining the lack of SF reports for BMS. Here, we report that ISR has a higher incidence with SF in EES, the clinical implication is that patients with SF after DES implantation merit careful follow-up.

Association between one-carbon metabolism indices and DNA methylation status in maternal and cord blood.

One-carbon metabolism is essential for multiple cellular processes and can be assessed by the concentration of folate metabolites in the blood. One-carbon metabolites serve as methyl donors that are required for epigenetic regulation. Deficiencies in these metabolites are associated with a variety of poor health outcomes, including adverse pregnancy complications. DNA methylation is known to vary with one-carbon metabolite concentration, and therefore may modulate the risk of adverse pregnancy outcomes. This study addresses changes in one-carbon indices over pregnancy and the relationship between maternal and child DNA methylation and metabolite concentrations by leveraging data from 24 mother-infant dyads. Five of the 13 metabolites measured from maternal blood and methylation levels of 993 CpG sites changed over the course of pregnancy. In dyads, maternal and fetal one-carbon concentrations were highly correlated, both early in pregnancy and at delivery. The 993 CpG sites whose methylation levels changed over pregnancy in maternal blood were also investigated for associations with metabolite concentrations in infant blood at delivery, where five CpG sites were associated with the concentration of at least one metabolite. Identification of CpG sites that change over pregnancy may result in better characterization of genes and pathways involved in maintaining a healthy, term pregnancy.

Percutaneous Hepatic Perfusion With Filtered Melphalan for Localized Treatment of Metastatic Hepatic Disease: A Risk Assessment.

Regional therapies for metastatic liver disease have garnered interest in recent years due to technological advances in drug delivery. A percutaneous hepatic perfusion (PHP) using a newly developed generation 2 (GEN2) filtration system was designed to mitigate systemic toxicity and cardiovascular risk associated with hepatic blood filtration during hepatic artery infusion of the chemotherapy drug melphalan. The GEN2 system was evaluated in healthy swine, and plasma samples were assessed for clinical chemistry, melphalan toxicokinetics (TK), inflammatory cytokines, catecholamines, hematological, and cardiac biomarkers. Cardiovascular safety was assessed by echocardiography, electrocardiogram, and telemetry. Toxicology parameters included clinical signs, body weight, gross pathology, and histopathology. There were no treatment-related deaths associated with the PHP procedure with GEN2 filtration, and all animals survived to scheduled necropsy. Assessment of the pharmacokinetic/TK plasma concentrations of melphalan demonstrated that the GEN2 filter was able to extract melphalan from blood with high efficiency and reduce melphalan exposure in the systemic circulation. The hemodynamic, immunosuppressive, immunotoxic, cardiotoxic, and histopathologic effects of melphalan were limited. The significant hemodynamic challenge imposed by filtration resulted in a compensatory tachycardia with supranormal left ventricular function, although no wall motion abnormalities were detected and left ventricular function remained normal. Catecholamines decreased and then quickly rebounded during washout. Transient and reversible effects of treatment on cardiac enzymes, catecholamines, and cytokines and reversible hemodynamic effects without cardiac damage indicated that PHP with melphalan was not cardiotoxic or immunotoxic under the conditions tested, due to high efficiency of the filtration system limiting exposure of melphalan to the systemic circulation.

Global folate status in women of reproductive age: a systematic review with emphasis on methodological issues.

Inadequate folate status in women of reproductive age (WRA) can lead to adverse health consequences of public health significance, such as megaloblastic anemia (folate deficiency) and an increased risk of neural tube defect (NTD)-affected pregnancies (folate insufficiency). Our review aims to evaluate current data on folate status of WRA. We queried eight databases and the World Health Organization Micronutrients Database, identifying 45 relevant surveys conducted between 2000 and 2014 in 39 countries. Several types of folate assays were used in the analysis of blood folate, and many surveys used folate cutoffs not matched to the assay. To allow better comparisons across surveys, we attempted to account for these differences. The prevalence of folate deficiency was >20% in many countries with lower income economies but was typically <5% in countries with higher income economies. Only 11 surveys reported the prevalence of folate insufficiency, which was >40% in most countries. Overall, folate status data for WRA globally are limited and must be carefully interpreted due to methodological issues. Future surveys would benefit from using the microbiologic assay to assess folate status, along with assay-matched cutoffs to improve monitoring and evaluation of folic acid interventions, thus informing global efforts to prevent NTDs.

CD4+ and CD8+ T-Cell-Specific DNA Cytosine Methylation Differences Associated With Obesity.

OBJECTIVE: Lifestyle factors associated with obesity may alter epigenome-regulated gene expression. Most studies examining epigenetic changes in obesity have analyzed DNA 5´-methylcytosine (5mC) in whole blood, representing a weighted average of several distantly related and regulated leukocyte classes. To examine leukocyte-specific differences associated with obesity, a pilot study examining 5mC in three distinct leukocyte types isolated from peripheral blood of women with normal weight and obesity was conducted. METHODS: CD4+ T cells, CD8+ T cells, and CD16+ neutrophils were reiteratively isolated from blood, and 5mC levels were measured across >450,000 CG sites. RESULTS: Nineteen CG sites were differentially methylated between women with obesity and with normal weight in CD4+ cells, 16 CG sites in CD8+ cells, and 0 CG sites in CD16+ neutrophils (q < 0.05). There were no common differentially methylated sites between the T-cell types. The amount of visceral adipose tissue was strongly associated with the methylation level of 79 CG sites in CD4+ cells, including 4 CG sites in CLSTN1's promoter, which, this study shows, may regulate its expression. CONCLUSIONS: The methylomes of various leukocytes respond differently to obesity and levels of visceral adipose tissue. Highly significant differentially methylated sites in CD4+ and CD8+ cells in women with obesity that have apparent biological relevance to obesity were identified.

Improving maternal folate status to prevent infant neural tube defects: working group conclusions and a framework for action.

As infectious disease control programs achieve increasing success, further reductions in child mortality in low- and middle-income countries (LMICs) will require focused prevention strategies for birth defects and other noninfectious diseases. Neural tube defects (NTDs) can cause early death or lifelong disability. Preventing NTDs provides a feasible, significant opportunity to decrease the toll of birth defects and contribute to further reducing child mortality globally. The Micronutrient Forum convened a technical consultation on Folate Status in Women and Neural Tube Defects Prevention to develop a roadmap to inform and prioritize investments in NTD prevention in LMICs; help guide implementation efforts in terms of the feasibility of interventions and the potential for acceleration; and identify research and knowledge gaps. Here, we describe the impetus for and approach to the consultation and present the conclusions and a framework for developing a roadmap for action to accelerate NTD prevention in LMICs. The framework (1) provides options for action on folate status assessment; (2) outlines a way forward to develop and implement a time-bound global action plan for NTD prevention; and (3) identifies common impediments to NTD prevention, broad strategies to overcome or minimize these impediments, and basic building blocks necessary to accelerate action.

Defining drug and target protein distributions after stent-based drug release: Durable versus deployable coatings.

BACKGROUND: Innovations in drug eluting stent designs make it increasingly important to develop models for differentiating performance through spatial definition of drug, receptor binding and cell state. METHODS: Two designs of sirolimus analog eluting stents were implanted into porcine coronary arteries for 28, 60 or 90 days (n = 9/time point), durable coating (Xience) and deployable absorbable coating (MiStent). Explanted arteries were evaluated for drug content (n = 3/time point) by LC-MS/MS and for drug and target protein (mTOR) distributions by immunofluorescence (IF, n = 6/time point). A computational model was developed to predict drug release and arterial distribution maps. RESULTS: Both stents released the majority of drug load by 28 days, with different tissue retention efficiencies (91.4 ±â€¯4.9% MiStent versus 21.5 ±â€¯1.9% Xience, P < 0.001). Computational modeling of MiStent coating deployment and microcrystal dissolution recapitulated in vivo drug release and net tissue content and predicted that >98.5% of deployed drug remains crystalline through 90 days. Immunofluorescence and computational modeling showed peristrut drug localization for both stents, with similar peaks, but high interstrut levels only at sites of coating deployment from the absorbable coating. Co-localization of mTOR-IF with drug-IF for both devices showed persistent drug effects, though with differential drug-receptor pharmacokinetics. CONCLUSIONS: Immunofluorescence and computational modeling provide insights into drug distribution and binding status that can help differentiate drug delivery technologies. Herein we found that tissue deployment of slow dissolving crystalline drug particles results in temporally and spatially more uniform drug delivery to interstrut zones that might otherwise be under-dosed without excess peristrut drug.

A public health approach for preventing neural tube defects: folic acid fortification and beyond.

In this paper we review the evidence basis for prevention of folic acid-sensitive neural tube defects (NTDs) through public health interventions in women of reproductive age (WRA), the proven vehicles for delivery of folic acid, and what is needed to effectively scale these, and provide a snapshot of potential innovations that require future research. Our primary focus is on the global situation affecting large-scale food fortification (LSFF) with folic acid, in particular the fortification of wheat flour and maize meal. Our overarching conclusion is that folic acid fortification is an evidence-based intervention that reduces the prevalence of NTDs, and that LSFF with folic acid is underutilized. Thus, food fortification with folic acid should be a component of most national public health strategies, in particular where folate status is insufficient and a fortifiable food vehicle, processed by a centralized industry, is consumed regularly by WRA. The evidence shows that there is still much work needed (1) to build the enabling environment and expand programs where there is currently no legislation, (2) to improve the low quality of delivery of existing programs, and (3) to measure and sustain programs by generating new coverage data and demonstrating evidence of impact in low- and middle-income countries.

Vessel centerline reconstruction from non-isocentric and non-orthogonal paired monoplane angiographic images.

PURPOSE: Three-dimensional reconstruction of a vessel centerline from paired planar coronary angiographic images is critical to reconstruct the complex three-dimensional structure of the coronary artery lumen and the relative positioning of implanted devices. In this study, a new vessel centerline reconstruction method that can utilize non-isocentric and non-orthogonal pairs of angiographic images was developed and tested. METHODS: Our new method was developed in in vitro phantom models of bifurcated coronary artery with and without stent, and then tested in in vivo swine models (twelve coronary arteries). This method was also validated using data from six patients. RESULTS: Our new method demonstrated high accuracy (root mean square error = 0.27 mm or 0.76 pixel), and high reproducibility across a broad imaging angle (20°-130°) and between different cardiac cycles in vitro and in vivo. Use of this method demonstrated that the vessel centerline in the stented segment did not deform significantly over a cardiac cycle in vivo. In addition, the total movement of the isocenter in each image could be accurately estimated in vitro and in vivo. The performance of this new method for patient data was similar to that for in vitro phantom models and in vivo animal models. CONCLUSIONS: We developed a vessel centerline reconstruction method for non-isocentric and non-orthogonal angiographic images. It demonstrated high accuracy and good reproducibility in vitro, in vivo, and in clinical setting, suggesting that our new method is clinically applicable despite the small sample size of clinical data.

Folate status in women of reproductive age as basis of neural tube defect risk assessment.

Reliable folate status data for women of reproductive age (WRA) to assess global risk for neural tube defects (NTDs) are needed. We focus on a recent recommendation by the World Health Organization that a specific "optimal" red blood cell (RBC) folate concentration be used as the sole indicator of NTD risk within a population and discuss how to best apply this guidance to reach the goal of assessing NTD risk globally. We also emphasize the importance of using the microbiologic assay (MBA) as the most reliable assay for obtaining comparable results for RBC folate concentration across time and countries, the need for harmonization of the MBA through use of consistent key reagents and procedures within laboratories, and the requirement to apply assay-matched cutoffs for folate deficiency and insufficiency. To estimate NTD risk globally, the ideal scenario would be to have country-specific population-based surveys of RBC folate in WRA determined utilizing a harmonized MBA, as was done in recent studies in Guatemala and Belize. We conclude with guidance on next steps to best navigate the road map toward the goal of generating reliable folate status data on which to assess NTD risk in WRA in low- and middle-income countries.

Distinctions in gene-specific changes in DNA methylation in response to folic acid supplementation between women with normal weight and obesity.

BACKGROUND/OBJECTIVES: Obesity and maternal folate deficiency are associated with increased risk for neural tube defects (NTDs). Limited knowledge exists on the impact of folate status or obesity on DNA methylation of genes related to NTD risk and folate metabolism. SUBJECTS/METHODS: Women (18-35y) with normal weight (NW; BMI 18.5-24.9kg/m2; n=12) and obesity (OB; BMI >30kg/m2; n=6) were provided FA (800µg/d) for 8-weeks. Serum folate concentration and changes in DNA methylation across 2098 CpG sites in 91 genes related to NTD risk and folate metabolism were examined. RESULTS: Serum folate concentration increased in both groups following FA supplementation, but OB maintained a relative lower concentration (NW; 38.36±2.50-71.41±3.02nmol/L and OB; 27.12±3.09-56.85±3.90nmol/L). Methylation of 56 and 99 CpG sites changed in response to supplementation in NW and OB, respectively, and majority of these sites decreased in methylation in both groups. Only 4 CpG sites responded to supplementation in both groups. Gene ontology analysis revealed a response to supplementation in 61 biological processes (BPs) from the selected genes. Five of the 61 BPs were identified only in NW, including neural tube closure, while 13 of the 61 BPs were enriched only in OB, including folate metabolism, vitamin B12 metabolism and methylation related processes. CONCLUSIONS: Changes in DNA methylation in genes related to NTD risk and folate metabolism in response to FA supplementation were different in NW and OB. Increased NTD risk and abnormal folate metabolism in obesity may be due to a distinctive epigenetic response to folate status in these genes.

Folate Deficiency Is Prevalent in Women of Childbearing Age in Belize and Is Negatively Affected by Coexisting Vitamin B-12 Deficiency: Belize National Micronutrient Survey 2011.

Background: Folate deficiency, vitamin B-12 deficiency, and anemia can have adverse effects on birth outcomes. Also, low vitamin B-12 reduces the formation of metabolically active folate.Objectives: We sought to establish the baseline prevalence of and factors associated with folate deficiency and insufficiency, vitamin B-12 deficiency, and anemia among women of childbearing age (WCBA) in Belize.Methods: In 2011, a national probability-based survey was completed among Belizean nonpregnant WCBA aged 15-49 y. Blood samples for determination of hemoglobin, folate (RBC and serum), and vitamin B-12 (plasma) and sociodemographic and health information were collected from 937 women. RBC and serum folate concentrations were measured by microbiologic assay (MBA). Folate status was defined based on both the WHO-recommended radioproteinbinding assay and the assay adjusted for the MBA.Results: The national prevalence estimates for folate deficiency in WCBA, based on serum and RBC folate concentrations by using the assay-matched cutoffs, were 11.0% (95% CI: 8.6%, 14.0%) and 35.1% (95% CI: 31.3%, 39.2%), respectively. By using the assay-matched compared with the WHO-recommended cutoffs, a substantially higher prevalence of folate deficiency was observed based on serum (6.9% absolute difference) and RBC folate (28.9% absolute difference) concentrations. The prevalence for RBC folate insufficiency was 48.9% (95% CI: 44.8%, 53.1%). Prevalence estimates for vitamin B-12 deficiency and marginal deficiency and anemia were 17.2% (95% CI: 14.2%, 20.6%), 33.2% (95% CI: 29.6%, 37.1%), and 22.7% (95% CI: 19.5%, 26.2%), respectively. The adjusted geometric means of the RBC folate concentration increased significantly (P-trend < 0.001) in WCBA who had normal vitamin B-12 status relative to WCBA who were vitamin B-12 deficient.Conclusions: In Belize, the prevalence of folate and vitamin B-12 deficiencies continues to be a public health concern among WCBA. Furthermore, low folate status co-occurred with low vitamin B-12 status, underlining the importance of providing adequate vitamin B-12 and folic acid intake through approaches such as mandatory food fortification.

DNA Methylation Changes in Whole Blood and CD16+ Neutrophils in Response to Chronic Folic Acid Supplementation in Women of Childbearing Age.

Folate, a water-soluble vitamin, is a key source of one-carbon groups for DNA methylation, but studies of the DNA methylation response to supplemental folic acid yield inconsistent results. These studies are commonly conducted using whole blood, which contains a mixed population of white blood cells that have been shown to confound results. The objective of this study was to determine if CD16+ neutrophils may provide more specific data than whole blood for identifying DNA methylation response to chronic folic acid supplementation. The study was performed in normal weight (BMI 18.5 - 24.9 kg/m2) women (18 - 35 y; n = 12), with blood samples taken before and after 8 weeks of folic acid supplementation at 800 µg/day. DNA methylation patterns from whole blood and isolated CD16+ neutrophils were measured across >485,000 CpG sites throughout the genome using the Infinium HumanMethylation450 BeadChip. Over the course of the 8-week supplementation, 6746 and 7513 CpG sites changed (p < 0.05) in whole blood and CD16+ neutrophils, respectively. DNA methylation decreased in 68.4% (whole blood) and 71.8% (CD16+ neutrophils) of these sites. There were only 182 CpG sites that changed in both the whole blood and CD16+ neutrophils, 139 of which changed in the same direction. These results suggest that the genome-wide DNA methylation response to chronic folic acid supplementation is different between whole blood and CD16+ neutrophils and that a single white blood cell type may function as a more specific epigenetic reporter of folate status than whole blood.

Ultra-hydrophilic stent platforms promote early vascular healing and minimise late tissue response: a potential alternative to second-generation drug-eluting stents.

AIMS: Simple surface modifications can enhance coronary stent performance. Ultra-hydrophilic surface (UHS) treatment of contemporary bare metal stents (BMS) was assessed in vivo to verify whether such stents can provide long-term efficacy comparable to second-generation drug-eluting stents (DES) while promoting healing comparably to BMS. METHODS AND RESULTS: UHS-treated BMS, untreated BMS and corresponding DES were tested for three commercial platforms. A thirty-day and a 90-day porcine coronary model were used to characterise late tissue response. Three-day porcine coronary and seven-day rabbit iliac models were used for early healing assessment. In porcine coronary arteries, hydrophilic treatment reduced intimal hyperplasia relative to the BMS and corresponding DES platforms (1.5-fold to threefold reduction in 30-day angiographic and histological stenosis; p<0.04). Endothelialisation was similar on UHS-treated BMS and untreated BMS, both in swine and rabbit models, and lower on DES. Elevation in thrombotic indices was infrequent (never observed with UHS, rare with BMS, most often with DES), but, when present, correlated with reduced endothelialisation (p<0.01). CONCLUSIONS: Ultra-hydrophilic surface treatment of contemporary stents conferred good healing while moderating neointimal and thrombotic responses. Such surfaces may offer safe alternatives to DES, particularly when rapid healing and short dual antiplatelet therapy (DAPT) are crucial.

An epigenetic clock for gestational age at birth based on blood methylation data.

BACKGROUND: Gestational age is often used as a proxy for developmental maturity by clinicians and researchers alike. DNA methylation has previously been shown to be associated with age and has been used to accurately estimate chronological age in children and adults. In the current study, we examine whether DNA methylation in cord blood can be used to estimate gestational age at birth. RESULTS: We find that gestational age can be accurately estimated from DNA methylation of neonatal cord blood and blood spot samples. We calculate a DNA methylation gestational age using 148 CpG sites selected through elastic net regression in six training datasets. We evaluate predictive accuracy in nine testing datasets and find that the accuracy of the DNA methylation gestational age is consistent with that of gestational age estimates based on established methods, such as ultrasound. We also find that an increased DNA methylation gestational age relative to clinical gestational age is associated with birthweight independent of gestational age, sex, and ancestry. CONCLUSIONS: DNA methylation can be used to accurately estimate gestational age at or near birth and may provide additional information relevant to developmental stage. Further studies of this predictor are warranted to determine its utility in clinical settings and for research purposes. When clinical estimates are available this measure may increase accuracy in the testing of hypotheses related to developmental age and other early life circumstances.

Vascular Response to Experimental Stent Malapposition and Under-Expansion.

Up to 80% of all endovascular stents have malapposed struts, and while some impose catastrophic events others are inconsequential. Thirteen stents were implanted in coronary arteries of seven healthy Yorkshire pigs, using specially-designed cuffed balloons inducing controlled stent malapposition and under-expansion. Optical coherence tomography (OCT) imaging confirmed that 25% of struts were malapposed (strut-wall distance

Particulates from hydrophilic-coated guiding sheaths embolise to the brain.

AIMS: We sought to evaluate the incidence of embolic material in porcine brains following vascular interventions using hydrophilic-coated sheaths. METHODS AND RESULTS: A new self-expanding stent and delivery system (SDS) was deployed through a hydrophilic-coated (Flexor Ansel; Cook Medical, Bloomington, IN, USA) guiding sheath into the iliac and/or carotid arteries of 23 anaesthetised Yucatan mini swine. The animals were euthanised at three, 30, 90 and 180 days and their brains were removed for histological analysis. In an additional single control animal, the guiding sheath was advanced but no SDS was deployed. Advancement of the coated guiding sheath with or without the SDS was associated with frequent foreign material in the arterioles of the brain. The embolic material was amorphous, non-refractile, non-crystalline, non-birefringent and typically lightly basophilic with a slightly stippled appearance on haematoxylin and eosin (H&E) stain. Material was observed at all time points involving 54% of all study animals (i.e., test and control) and in vitro after incubation in 0.9% saline. CONCLUSIONS: The hydrophilic coating on a clinically used guiding sheath readily avulses and embolises to the brain during deployment in a porcine model. Further documentation of this effect and monitoring in clinical scenarios are warranted.