Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube

We report on a measurement of astrophysical tau neutrinos with 9.7 yr of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate ν_{τ} events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent ν_{τ} energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrinos, and muons from π^{±}/K^{±} decays in atmospheric air showers, we obtain a total estimated background of about 0.5 events, dominated by non-ν_{τ} astrophysical neutrinos. Thus, we rule out the absence of astrophysical ν_{τ} at the 5σ level. The measured astrophysical ν_{τ} flux is consistent with expectations based on previously published IceCube astrophysical neutrino flux measurements and neutrino oscillations.

Online physiotherapy for people with axial spondyloarthritis: quantitative and qualitative data from a cohort study

Life-long exercise is essential in axial spondyloarthritis (axSpA) management; however, long-term adherence is challenging. Online exercise programmes are an alternative to face-to-face physiotherapy. (1) To measure adherence to a 12-month, individualised, online physiotherapy programme for people with axSpA, and investigate the effects on disease activity, spinal mobility, work ability, quality of life and function. (2) To investigate associations between programme adherence and outcomes. (3) To explore participants' views of the programme and factors affecting adherence. Participants were 'non-exercisers' recruited from rheumatology outpatient services. Adherence was measured using online diary entries. Outcomes included the BATH indices, health status (EQ5D), Ankylosing Spondylitis Quality of Life (ASQOL), exercise capacity (6MWT), Work, Productivity and Activity Impairment in AS (WPAI), Exercise Attitude Questionnaire (EAQ) and Exercise Motivations Inventory-2 (EMI-2) at baseline, 6 and 12 months. Interviews determined views on the intervention and factors affecting adherence. Fifty participants were recruited. Over the 52-week intervention, adherence (five times/week) ranged from 19% (± 30%) to 44% (± 35%). Significant improvements were found in disease activity (BASDAI), spinal mobility (BASMI), 6MWT, AsQoL and EQ5D-VAS at 6 and 12 months. There were no associations between adherence and baseline variables or demographics. Interviews suggested support from others, routine, and feeling the benefit positively affected adherence. Conversely, lack of motivation, life events and symptoms negatively affected adherence. A 12-month online physiotherapy programme significantly improved symptoms in people with axSpA who were not regular exercisers. Adherence reduced over the intervention period. Online exercise programmes may benefit people with axSpA; however, strategies to improve adherence are required.

Observation of high-energy neutrinos from the Galactic plane

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

Evidence for neutrino emission from the nearby active galaxy NGC 1068

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of 79 − 20 + 22 neutrinos at tera–electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{μ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9}  eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{μ} Disappearance at IceCube

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{μτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

Search for Relativistic Magnetic Monopoles with Eight Years of IceCube Data

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19}  cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with β≳0.8 and up to β∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

Anakinra for recalcitrant pyoderma gangrenosum

Pyoderma gangrenosum (PG) is an autoinflammatory neutrophilic dermatosis characterized by rapidly enlarging, painful ulcers. Anakinra is a recombinant interleukin (IL)-1 receptor antagonist that blocks the activity of IL-1α and IL-1β by competitively inhibiting IL-1 binding to the IL-1 type 1 receptor. We present a series of two patients with recalcitrant PG, who had limited therapeutic options and multiple comorbidities and multiple previous treatment failures, who obtained 100% healing with anakinra. Compared with conventional first-line therapies for PG, the safety profile of anakinra may be preferable for patients with multiple comorbidities. Further research is needed to assess the safety and efficacy of anakinra for PG.

Structural characterization of cassava linamarase-linamarin enzyme complex: an integrated computational approach

Cassava linamarase is a hydrolyzing enzyme that belongs to a glycoside hydrolase family 1 (GH1). It is responsible for breaking down linamarin to toxic cyanide. The enzyme provides a defensive mechanism for plants against herbivores and has various applications in many fields. Understanding the structure of linamarase at the molecular level is a key to avail its reaction mechanism. In this study, the three-dimensional (3D) structure of linamarase was built for the first time using homology modelling and used to study its interaction with linamarin. Molecular docking calculations established the binding and orientation nature of linamarin, while molecular dynamics (MD) simulation established protein-ligand complexes' stability. Binding-free energy based on MM/PBSA was further used to rescore the docking results. An ensemble structure was found to be relatively stable compared to the modelled structure. This study sheds light on the exploration of linamarase towards understanding its reaction mechanisms.Communicated by Ramaswamy H. Sarma.

Genetic variants modify the associations of concentrations of methylmalonic acid, vitamin B-12, vitamin B-6, and folate with bone mineral density

BACKGROUND

Elevated plasma homocysteine has been found to be associated with an increased risk of osteoporosis, especially hip and vertebral fractures. The plasma concentration of homocysteine is dependent on the activities of several B vitamin-dependent enzymes, such as methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTR), methionine synthase reductase (MTRR), and cystathionine β-synthase (CBS).

OBJECTIVES

We investigated whether genetic variants in some of the genes involved in 1 carbon metabolism modify the association of B vitamin-related measures with bone mineral density (BMD) and strength.

METHODS

We measured several B vitamins and biomarkers in participants of the Framingham Offspring Study, and performed analyses of methylmalonic acid (MMA) continuously and <210 nmol/L; pyridoxal-5'-phosphate; vitamin B-12 continuously and ≥258 pmol/L; and folate. The outcomes of interest included areal and volumetric BMD, measured by DXA and quantitative computed tomography (QCT), respectively. We evaluated associations between the bone measures and interactions of single nucleotide polymorphism with a B vitamin or biomarker in Framingham participants (n = 4310 for DXA and n = 3127 for QCT). For analysis of DXA, we validated the association results in the B-PROOF cohort (n = 1072). Bonferroni-corrected locus-wide significant thresholds were defined to account for multiple testing.

RESULTS

The interactions between rs2274976 and vitamin B-12 and rs34671784 and MMA <210 nmol/L were associated with lumbar spine BMD, and the interaction between rs6586281 and vitamin B-12 ≥258 pmol/L was associated with femoral neck BMD. For QCT-derived traits, 62 interactions between genetic variants and B vitamins and biomarkers were identified.

CONCLUSIONS

Some genetic variants in the 1-carbon methylation pathway modify the association of B vitamin and biomarker concentrations with bone density and strength.  These interactions require further replication and functional validation for a mechanistic understanding of the role of the 1-carbon metabolism pathway on BMD and risks of fracture.

A Code of Ethics for Gene Drive Research

Gene drives hold promise for use in controlling insect vectors of diseases, agricultural pests, and for conservation of ecosystems against invasive species. At the same time, this technology comes with potential risks that include unknown downstream effects on entire ecosystems as well as the accidental or nefarious spread of organisms that carry the gene drive machinery. A code of ethics can be a useful tool for all parties involved in the development and regulation of gene drives and can be used to help ensure that a balanced analysis of risks, benefits, and values is taken into consideration in the interest of society and humanity. We have developed a code of ethics for gene drive research with the hope that this code will encourage the development of an international framework that includes ethical guidance of gene drive research and is incorporated into scientific practice by gaining broad agreement and adherence.

Changing Behaviour towards Aerobic and Strength Exercise (BASE): Design of a randomised, phase I study determining the safety, feasibility and consumer-evaluation of a remotely-delivered exercise programme in persons with multiple sclerosis

BACKGROUND

Multiple sclerosis is a chronic progressive neurological disease. Evidence attests to the benefits of exercise, guidelines for exercise in multiple sclerosis are available. Remote-delivery of exercise adherence programmes based on the exercise guidelines require urgent testing.

AIMS

The design, and outcomes of Behaviour towards Aerobic and Strength Exercise in MS (BASE-MS), a remotely-delivered exercise training study based principles of behaviour change, will further evaluate the remote-delivery of the current exercise guidelines.

METHODS

BASE is a 4-month clinically relevant randomised controlled trial to explore the delivery of a remotely supervised, guidelines-based exercise programme for persons with multiple sclerosis, underpinned by principles of health behaviour change. Initially, 72 persons with mild to moderate multiple sclerosis will be randomised in a 1:1:1 allocation to receive the BASE programme, or act as controls continuing usual care. On programme completion, exercise participants will be further randomised to an optimised adherence treatment or usual adherence. Our online survey assesses the primary outcome of exercise participation, and secondary outcomes of symptoms, and correlates of behaviour change at baseline, month four, month five and month eleven. Online surveys will capture coach and participant feedback to identify the contexts, mechanisms and outcomes of BASE implementation.

CONCLUSIONS

The research and clinical landscape for MS management must remain in-step with public health and health communication. BASE tests the remote-delivery of the current exercise guidelines for exercise in persons with MS. Safety, feasibility and evaluative outcomes will provide rich data for future remote-delivery of exercise in neurological conditions.

Balance Right in Multiple Sclerosis (BRiMS): a feasibility randomised controlled trial of a falls prevention programme

Background

Balance, mobility impairments and falls are problematic for people with multiple sclerosis (MS). The “Balance Right in MS (BRiMS)” intervention, a 13-week home and group-based exercise and education programme, aims to improve balance and minimise falls. This study aimed to evaluate the feasibility of undertaking a multi-centre randomised controlled trial and to collect the necessary data to design a definitive trial.

Methods

This randomised controlled feasibility study recruited from four United Kingdom NHS clinical neurology services. Patients ≥ 18 years with secondary progressive MS (Expanded Disability Status Scale 4 to 7) reporting more than two falls in the preceding 6 months were recruited. Participants were block-randomised to either a manualised 13-week education and exercise programme (BRiMS) plus usual care, or usual care alone.

Feasibility assessment evaluated recruitment and retention rates, adherence to group assignment and data completeness. Proposed outcomes for the definitive trial (including impact of MS, mobility, quality of life and falls) and economic data were collected at baseline, 13 and 27 weeks, and participants completed daily paper falls diaries.

Results

Fifty-six participants (mean age 59.7 years, 66% female, median EDSS 6.0) were recruited in 5 months; 30 randomised to the intervention group. Ten (18%) participants withdrew, 7 from the intervention group. Two additional participants were lost to follow up at the final assessment point. Completion rates were > 98% for all outcomes apart from the falls diary (return rate 62%).

After adjusting for baseline score, mean intervention—usual care between-group differences for the potential primary outcomes at week 27 were MS Walking Scale-12v2: − 7.7 (95% confidence interval [CI] − 17.2 to 1.8) and MS Impact Scale-29v2: physical 0.6 (CI − 7.8 to 9), psychological − 0.4 (CI − 9.9 to 9). In total, 715 falls were reported, rate ratio (intervention:usual care) for falls 0.81 (0.41 to 2.26) and injurious falls 0.44 (0.41 to 2.23).

Conclusions

Procedures were practical, and retention, programme engagement and outcome completion rates satisfied a priori progression criteria. Challenges were experienced in completion and return of daily falls diaries. Refinement of methods for reporting falls is therefore required, but we consider a full trial to be feasible.

Trial registration

ISRCTN13587999

Date of registration: 29 September 2016

A prospective birth cohort study on cord blood folate subtypes and risk of autism spectrum disorder

BACKGROUND

We previously reported that extremely high concentrations of maternal plasma folate were associated with increased risk of autism spectrum disorder (ASD) in children. This study explored whether specific types of folate in cord blood have differential association with ASD.

OBJECTIVES

In the Boston Birth Cohort (BBC), we assessed the association between cord blood unmetabolized folic acid (UMFA), 5-methyl tetrahydrofolate (THF), and total folate and a child's ASD risk. In a subset, we explored whether the association between UMFA and ASD risk can be affected by the dihydrofolate reductase (DHFR) genotype and cord plasma creatinine. We also examined prenatal correlates of cord UMFA concentrations.

METHODS

This report included 567 BBC children (92 ASD, 475 neurotypical), who were recruited at birth and prospectively followed at the Boston Medical Center. ASD was defined from International Classification of Diseases (ICD)-9 and ICD-10 codes documented in electronic medical records.

RESULTS

Children with cord UMFA in the highest, versus lowest quartile, had a greater ASD risk (adjusted OR, aORquartile4: 2.26; 95% CI: 1.08, 4.75). When stratified by race/ethnicity, the association was limited to 311 (45 ASD) Black children (aORquartile4: 9.85; 95% CI: 2.53, 38.31); a test of interaction between race/ethnicity and cord UMFA concentrations was significant (P = 0.007). The UMFA-ASD association in Black children slightly attenuated after adjusting for cord plasma creatinine (P = 0.05). There was no significant association between cord 5-methyl THF, total folate, DHFR genotype, and ASD risk. Cord total folate and maternal supplement intake during second trimester were associated with higher cord UMFA.

CONCLUSIONS

Higher concentrations of cord UMFA, but not 5-methyl THF or total folate, were associated with a greater risk of ASD in Black children. This study in a preterm-birth-enriched cohort raises more questions than it could answer and underscores the need for additional investigations on the sources and role of cord UMFA in children's neurodevelopmental outcomes and underlying mechanisms.

Determining validity of the PALite and ODFS PACE activity logger for measuring step count in healthy adults

BACKGROUND

Determining adherence with orthoses is important for clinicians prescribing devices. Measuring orthotic use often relies on patient recall which has poor agreement with objective measures. Measuring step count whilst wearing an orthosis could help objectively quantifying adherence. The Odstock Drop Foot Stimulator (ODFS) Pace, used in foot drop, has an integral activity logger which provides data on step count. The PALite, an accelerometer, measures step count and can be fixed to an ankle foot orthoses (AFO). Both have the potential to provide objective measures of adherence; however, their validity for this purpose has not been determined.

RESEARCH QUESTION

To determine the validity of the PALite and ODFS Pace activity logger in measuring total step count, by exploring their level of agreement.

METHODS

A convenience sample of sixteen healthy volunteers, aged 18-65, were recruited from Glasgow Caledonian University (GCU). Participants walked continuously for 5 min on a treadmill at three walking speeds; normal (1.3ms^-1), slow (0.4 ms^-1) and fast (1.7-2.0 ms^-1), wearing both the PALite and ODFS Pace. All walks were video recorded, viewed by 2 raters, and observed step count was determined by a click counter. Step count from both devices was validated against observed step count using video recording. The level of agreement between the three methods was established.

RESULTS

There was no significant difference between the 3 methods of measuring step count at any walking speed (normal, p = 0.913; slow, p = 0.938; fast, p = 0.566). Good levels of agreement for both devices with observed step count at all 3 walking speeds, with mean percentage differences being between -1.2 and 2.1 % (maximum upper and lower levels of agreement = 19.5 and -18.8 %) was detected.

SIGNIFICANCE

Clinicians could consider both devices to objectively measure step count with people who are prescribed foot drop orthoses, thus quantifying orthotic use.

Association Between Folate Metabolites and the Development of Food Allergy in Children

BACKGROUND

Studies on the association between folate/folic acid exposure and the development of allergic disease have yielded inconsistent results, which may be due, in part, to lack of data distinguishing folate from folic acid exposure.

OBJECTIVE

To examine the association between total folate, 5-methyltetrahydrofolate (5-MTHF), and unmetabolized folic acid (UMFA) concentrations at birth and in early childhood and the development of food sensitization (FS) and food allergy (FA).

METHODS

A nested case control study was performed in the Boston Birth Cohort (BBC). Total folate, 5-MTHF, and UMFA were measured at birth and in early childhood. Based on food-specific IgE (sIgE) levels, diet, and clinical history, children were classified as FS (sIgE ≥0.35 kU/L), FA, or non-FS/FA (controls). Folate concentrations were divided into quartiles, and multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Of a total of 1394 children, 507 children with FS and 78 with FA were identified. Although mean total folate concentrations at birth were lower among those who developed FA (30.2 vs 35.3 nmol/L; P = .02), mean concentrations of the synthetic folic acid derivative, UMFA, were higher (1.7 vs 1.3 nmol/L, P = .001). Higher quartiles of UMFA at birth were associated more strongly with FA (OR 8.50; 95% CI 1.7-42.8; test for trend P = .001). Neither early childhood concentrations of 5-MTHF nor UMFA were associated with the development of FS or FA.

CONCLUSION

Among children in the BBC, higher concentrations of UMFA at birth were associated with the development of FA, which may be due to increased exposure to synthetic folic acid in utero or underlying genetic differences in synthetic folic acid metabolism.

Fortification of bakery and corn masa-based foods in Mexico and dietary intake of folic acid and folate in Mexican national survey data

BACKGROUND

In Mexico, wheat and corn flour fortification with folic acid (FA) was implemented in 2001 and mandated in 2008, but without direct enforcement. Current Mexican nutrient-content tables do not account for FA contained in bakery bread and corn masa-based foods, which are dietary staples in Mexico.

OBJECTIVE

The objective of this study was to examine the impact of FA fortification of dietary staples on the proportion of the population consuming below the Estimated Average Requirement (EAR) for folate or above the Tolerable Upper Intake Level (UL) for FA.

METHODS

We measured FA and folate content in dietary staples (bakery bread and tortillas) using microbial assays and MS, and we recalculated FA intake from 24-h recall dietary intake data collected in the 2012 Mexican National Health and Nutrition Survey (Encuesta Nacional de Salud y Nutrición) utilizing estimates from our food measurements, using nutrient concentrations from tortillas to approximate nutrient content of other corn masa-derived foods. The revised FA intake estimates were used to examine population-level intake of FA and dietary folate equivalent (DFE) accounting for geographic differences in FA content with statistical models.

RESULTS

FA content in dietary staples was variable, whereas use of FA-fortified flour in corn masa tortillas increased with population size in place of residence. Accounting for dietary staples' FA fortification increased population estimates for FA and DFE intake, resulting in a lower proportion with intake below the EAR and a higher proportion with intake above the UL. Despite accounting for FA-fortified staple foods, 9-33% of women of childbearing age still have intake below the EAR, whereas up to 12% of younger children have intake above the UL.

CONCLUSIONS

Unregulated FA fortification of dietary staples leads to unpredictable total folate intake without adequately impacting the intended target. Our findings suggest that monitoring, evaluation, and enforcement of mandatory fortification policies are needed. Without these, alternate strategies may be needed in order to reach women of childbearing age while avoiding overexposing children.

Lycopene Inhibits Smoke-Induced Chronic Obstructive Pulmonary Disease and Lung Carcinogenesis by Modulating Reverse Cholesterol Transport in Ferrets

Chronic obstructive pulmonary disease (COPD) and lung cancer share the same etiologic factor, cigarette smoking. Higher consumption of dietary lycopene has been associated with lower risks of COPD and lung cancer in smokers. We investigated whether lycopene feeding protects against COPD and lung cancer in ferrets, a nonrodent model that closely mimics cigarette smoke (CS)-induced chronic bronchitis, emphysema, and lung tumorigenesis in human. We also explored whether the protective effect of lycopene is associated with restoring reverse cholesterol transport (RCT), a key driver in persistent inflammation with CS exposure. Ferrets (4 groups, n = 12-16/group) were exposed to a combination of tobacco carcinogen (NNK) and CS with or without consuming lycopene at low and high doses (equivalent to ∼30 and ∼90 mg lycopene/day in human, respectively) for 22 weeks. Results showed that dietary lycopene at a high dose significantly inhibited NNK/CS-induced chronic bronchitis, emphysema, and preneoplastic lesions, including squamous metaplasia and atypical adenomatous hyperplasia, as compared with the NNK/CS alone (P < 0.05). Lycopene feeding also tended to decrease the lung neoplastic lesions. Furthermore, lycopene feeding significantly inhibited NNK/CS-induced accumulation of total cholesterol, and increased mRNA expression of critical genes related to the RCT (PPARα, LXRα, and ATP-binding cassette transporters ABCA1 and ABCG1) in the lungs, which were downregulated by the NNK/CS exposure. The present study has provided the first evidence linking a protective role of dietary lycopene against COPD and preneoplastic lesions to RCT-mediated cholesterol accumulation in lungs.

Modulation of Reverse Cholesterol Transport by Lycopene Is Associated with Its Protective Role Against Cigarette Smoke Induced COPD and Lung Carcinogenesis in Ferrets (OR05-02-19)

Objectives

Reverse cholesterol transport (RCT), which mediates removal of excess cholesterol from peripheral tissues, is a key player in persistent lung inflammation, a common feature of chronic obstructive pulmonary disease (COPD) and lung cancer, after cigarette smoke (CS) exposure. We have previously shown that lycopene, a carotenoid naturally occurring in tomatoes and tomato products, inhibits tobacco carcinogen (NNK)/CS-induced COPD and preneoplastic lesions in lung of ferrets, but the mechanism is unknown. We hypothesize that the protective role of lycopene against NNK/CS-induced COPD and lung preneoplastic lesions is associated with restoring the RCT in ferrets.

Methods

Male ferrets (4 groups, n = 12−16/group) were exposed to combination of NNK and CS with or without lycopene feeding at low (LL) and high (HL) doses (equivalent to ∼30 mg and ∼90 mg lycopene/day in humans, respectively) for 22 weeks. Ferrets in NNK/CS groups were given NNK (50 mg/kg body weight, i.p. injection) once a month for 4 consecutive months, and were exposed to CS for 30 min/day for 22 weeks. The animals were fed lycopene or placebo starting three weeks prior to the NNK injections and continued until the end of the study.

Results

NNK/CS exposure significantly increased total cholesterol levels in both plasma and lungs of ferrets (P < 0.05), which was associated with COPD and lung preneoplastic lesion development. In lungs, HL and LL doses lowered NNK/CS-induced total cholesterol, with HL dose reaching significance (P < 0.05); this was accompanied with the decreased lung lesions. HL group had significantly higher mRNA expression of critical genes involved in RCT (LXRα, PPARα, ABCA1 and ABCG1) as compared to NNK/CS group (P < 0.05). Additionally, HL feeding significantly increased protein levels of both nuclear hormone receptors, LXRα and PPARα, known regulators of ABCA1/G1 transporters (P < 0.05). In plasma, lycopene restored total cholesterol and HDL-C concentrations to normal. Plasma triglyceride, LDL-C and VLDL-C concentrations were not significantly different between groups.

Conclusions

These data demonstrate an important association between lycopene protection against NNK/CS induced lung lesions and pulmonary cholesterol homeostasis through the restoration of the impaired RCT.

Funding Sources

NIH/NCI, USDA/ARS grants.

A case-control analysis of maternal diet and risk of neural tube defects in Bangladesh

OBJECTIVES

Mothers need a nutrient-rich diet for healthy neural tube development. Neural tube defect risk can be reduced through fortifying grain products with folic acid and taking folic acid supplements. Fortification is not required in Bangladesh. Maternal supplement use rates are low, similar to other countries. This study evaluates maternal dietary intake during pregnancy to identify possible interventions.

METHODS

A food frequency questionnaire (FFQ) assessed maternal diet. The primary aim compared dietary intake (calories, fat, carbohydrate, protein, fiber, vitamins, and minerals) between mothers of infants with myelomeningocele (cases) and mothers of controls. Secondary aims included (i) comparing foods consumed and (ii) evaluating if rice intake correlated with arsenic exposure. Paired t-tests, Wilcoxon signed rank tests, McNemar's chi-squared test, and linear regression were used.

RESULTS

This study included 110 matched mother-infant pairs (55 cases/55 controls). Mothers of cases and mothers of controls had similar caloric intake [median 2406 kcal/day vs. 2196 kcal/day (p = 0.071)]. Mothers in both groups consumed less than half the daily recommended 600 μg of folate. Diets were potentially deficient in vitamins A, D, E, potassium, sodium, and iron. Steamed rice was the primary food consumed for both groups, and this rice intake was not associated with toenail arsenic.

CONCLUSIONS

Dietary interventions should increase folate, vitamins A, D, E, potassium, sodium, and iron intake in Bangladeshi mothers. Folic acid fortification of grain products maybe the only viable strategy to achieve adequate folate intake for mothers. Given the central role of rice to the Bangladeshi diet, fortifying rice may be a viable option.

Level of adherence to prescribed exercise in spondyloarthritis and factors affecting this adherence: a systematic review

Adherence is a primary determinant of the effectiveness of any intervention. Exercise is considered essential in the management of spondyloarthritis (SpA); however, the overall adherence to exercise programmes and factors affecting adherence are unknown. The aim of this systematic review was to examine measures of, and factors influencing adherence to, prescribed exercise programmes in people with SpA. A search was performed in August 2018 using five data bases; the Cochrane library, CINAHL, EMBASE, MEDLINE, and Web of Science Collections. Inclusion criteria were: studies with adults (> 18 years) with SpA, with a prescribed exercise intervention or educational programme with the aim of increasing exercise participation. Article quality was independently assessed by two assessors. Extracted descriptive data included: populations, interventions, measures of adherence and factors affecting adherence. Percentage adherence rates to prescribed exercises were calculated if not reported. Nine studies were included with a total of 658 participants, 95% of participants had a diagnosis of ankylosing spondylitis. Interventions and measurement of adherence varied, making comparisons difficult. Rates of adherence ranged from 51.4 to 95%. Single studies identified; adherence improved following educational programmes, and higher disease severity and longer diagnostic delays were associated with higher adherence. Conflicting evidence was found as to whether supervision of exercise improved adherence. Three consecutive studies demonstrated adherence reduced over time. Adherence to prescribed exercise in SpA was poorly reported and predominately for people with AS. The levels of adherence and factors affecting prescribed exercise in SpA remain unclear. Future research should measure adherence across a longer time period and investigate possible factors which may influence adherence.

Curcumin and piperine supplementation of obese mice under caloric restriction modulates body fat and interleukin-1β

Background

Dietary bioactive compounds capable of improving metabolic profiles would be of great value, especially for overweight individuals undergoing a caloric restriction (CR) regimen. Curcumin (Cur), a possible anti-obesity compound, and piperine (Pip), a plausible enhancer of Cur’s bioavailability and efficacy, may be candidate agents for controlling body fat, metabolism and low grade inflammation.

Methods

47 eight-week-old male C57BL/6 mice were fed a high fat diet (HFD) for 23 weeks to induce obesity. Then, mice were divided into 5 groups. Group 1 continued on HFD ad libitum. The other 4 groups underwent CR (reduced 10% HFD intake for 10 weeks, 20% for 20 weeks) with Cur, Pip, Cur + Pip or none of these. Percent body fat, plasma inflammatory markers associated with obesity (interferon (IFN)-γ, interleukin (IL)-10, IL-12 p70, IL-1β, IL-6 and KC/GRO), plasma Cur metabolites and liver telomere length were measured.

Results

Compared to the other groups, obese mice who underwent CR and received Cur + Pip in their diet lost more fat and had significantly lower IL-1β and KC/GRO. Tandem mass spectrometry analysis of plasma from obese mice under CR showed no difference in Cur metabolite levels between groups supplemented with Cur alone or combined with Pip. However, plasma IL-1β levels were inversely correlated with curcumin glucuronide. Minor modulation of telomere length were observed.

Conclusions

It is plausible that supplementing the high fat diet of CR mice with Cur + Pip may increase loss of body fat and suppresses HFD induced inflammation. Combination of Cur and Pip has potential to enhance CR effects for the prevention of metabolic syndrome.

Skin Cancer Awareness Amongst Irish Golfers

Aim The aim of this study was to assess skin cancer awareness and identify the UV protective measures used by golfers within the Munster region of Ireland. Methods Subjects were recruited from throughout the Munster region at a regional competition, and at three other local golf clubs and "pro" shops. Participants filled out a short anonymous validated questionnaire when collecting their score cards7. Results One hundred and sixty-three golfers completed the questionnaire with a mean age of 65.6 years. 137 (84%) were male and 26 (16%) were female. We noted a high incidence of both non-melanoma and melanoma skin cancer in our subjects. Sixteen (9.8%) had a previous history of skin cancer, with 8 melanomas and 8 non-melanoma skin cancers. A high percentage, 85%, of the golfers surveyed were compliant with SPF use. However many were using too low a SPF, 63 (44%) were using a SPF less than 30. Knowledge of risk of skin cancer is better amongst the golfers surveyed when compared to the general population. Most respondents (N = 96 (59%)) were aware that melanoma can lead to death if left untreated and 114 (70%) recognized that melanoma can be cured if treated early. Conclusion Golfers may benefit from targeted education emphasizing the importance of higher SPF use. Other interventions that may benefit this population would include availability of sunscreens and educational literature in 'pro' shops at golf courses.

Balance Right in Multiple Sclerosis (BRiMS): a guided self-management programme to reduce falls and improve quality of life, balance and mobility in people with secondary progressive multiple sclerosis: a protocol for a feasibility randomised controlled trial

BACKGROUND

Impaired mobility is a cardinal feature of multiple sclerosis (MS) and is rated by people with MS as their highest priority. By the secondary progressive phase, balance, mobility and physical activity levels are significantly compromised; an estimated 70% of people with secondary progressive MS fall regularly. Our ongoing research has systematically developed 'Balance Right in MS' (BRiMS), an innovative, manualised 13-week guided self-management programme tailored to the needs of people with MS, designed to improve safe mobility and minimise falls. Our eventual aim is to assess the clinical and cost effectiveness of BRiMS in people with secondary progressive MS by undertaking an appropriately statistically powered, multi-centre, assessor-blinded definitive, randomised controlled trial. This feasibility study will assess the acceptability of the intervention and test the achievability of running such a definitive trial.

METHODS/DESIGN

This is a pragmatic multi-centre feasibility randomised controlled trial with blinded outcome assessment. Sixty ambulant people with secondary progressive MS who self-report two or more falls in the previous 6 months will be randomly allocated (1:1) to either the BRiMS programme plus usual care or to usual care alone. All participants will be assessed at baseline and followed up at 15 weeks and 27 weeks post-randomisation. The outcomes of this feasibility trial include:Feasibility outcomes, including trial recruitment, retention and completionAssessment of the proposed outcome measures for the anticipated definitive trial (including measures of walking, quality of life, falls, balance and activity level)Measures of adherence to the BRiMS programmeData to inform the economic evaluation in a future trialProcess evaluation (assessment of treatment fidelity and qualitative evaluation of participant and treating therapist experience).

DISCUSSION

The BRiMS intervention aims to address a key concern for MS service users and providers. However, there are several uncertainties which need to be addressed prior to progressing to a full-scale trial, including acceptability of the BRiMS intervention and practicality of the trial procedures. This feasibility trial will provide important insights to resolve these uncertainties and will enable a protocol to be finalised for use in the definitive trial.

TRIAL REGISTRATION

ISRCTN13587999.

Bacterial Folates Provide an Exogenous Signal for C. elegans Germline Stem Cell Proliferation

Here we describe an in vitro primary culture system for Caenorhabditis elegans germline stem cells. This culture system was used to identify a bacterial folate as a positive regulator of germ cell proliferation. Folates are a family of B-complex vitamins that function in one-carbon metabolism to allow the de novo synthesis of amino acids and nucleosides. We show that germ cell proliferation is stimulated by the folate 10-formyl-tetrahydrofolate-Glun both in vitro and in animals. Other folates that can act as vitamins to rescue folate deficiency lack this germ cell stimulatory activity. The bacterial folate precursor dihydropteroate also promotes germ cell proliferation in vitro and in vivo, despite its inability to promote one-carbon metabolism. The folate receptor homolog FOLR-1 is required for the stimulation of germ cells by 10-formyl-tetrahydrofolate-Glun and dihydropteroate. This work defines a folate and folate-related compound as exogenous signals to modulate germ cell proliferation.

Validity of the activPAL3 activity monitor in people moderately affected by Multiple Sclerosis

Walking is the primary form of physical activity performed by people with Multiple Sclerosis (MS), therefore it is important to ensure the validity of tools employed to measure walking activity. The aim of this study was to assess the criterion validity of the activPAL3 activity monitor during overground walking in people with MS. Validity of the activPAL3 accelerometer was compared to video observation in 20 people moderately affected by MS. Participants walked 20-30m twice along a straight quiet corridor at a comfortable speed. Inter-rater reliability of video observations was excellent (all intraclass correlations >0.99). The mean difference (activPAL3- mean of raters) was -4.70±9.09, -4.55s±10.76 and 1.11s±1.11 for steps taken, walking duration and upright duration respectively. These differences represented 8.7%, 10.0% and 1.8% of the mean for each measure respectively. The activPAL3 tended to underestimate steps taken and walking duration in those who walked at cadences of ≤38 steps/min by 60% and 47%, respectively. The activPAL3 is valid for measuring walking activity in people moderately affected by MS. It is accurate for upright duration regardless of cadence. In participants with slow walking cadences, outcomes of steps taken and walking duration should be interpreted with caution.

Associations between post translational histone modifications, myelomeningocele risk, environmental arsenic exposure, and folate deficiency among participants in a case control study in Bangladesh

Arsenic exposure may contribute to disease risk in humans through alterations in the epigenome. Previous studies reported that arsenic exposure is associated with changes in plasma histone concentrations. Posttranslational histone modifications have been found to differ between the brain tissue of human embryos with neural tube defects and that of controls. Our objectives were to investigate the relationships between plasma histone 3 levels, history of having an infant with myelomeningocele, biomarkers of arsenic exposure, and maternal folate deficiency. These studies took place in Bangladesh, a country with high environmental arsenic exposure through contaminated drinking water. We performed ELISA assays to investigate plasma concentration of total histone 3 (H3) and the histone modification H3K27me3. The plasma samples were collected from 85 adult women as part of a case-control study of arsenic and myelomeningocele risk in Bangladesh. We found significant associations between plasma %H3K27me3 levels and risk of myelomeningocele (P<0.05). Mothers with higher %H3K27me3 in their plasma had lower risk of having an infant with myelomeningocele (odds ratio: 0.91, 95% confidence interval: 0.84, 0.98). We also found that arsenic exposure, as estimated by arsenic concentration in toenails, was associated with lower total H3 concentrations in plasma, but only among women with folate deficiency (β = -9.99, standard error = 3.91, P=0.02). Our results suggest that %H3K27me3 in maternal plasma differs between mothers of infants with myelomeningocele and mothers of infants without myelomeningocele, and may be a marker for myelomeningocele risk. Women with folate deficiency may be more susceptible to the epigenetic effects of environmental arsenic exposure.

Abstract P6-01-14: Dissection of the Abl interactor 1 signaling in metastatic breast cancer cells

Abl interactor 1 (Abi1) is a key component of WAVE regulatory complex (WRC) that regulates actin cytoskeleton reorganization, membrane receptor signaling, and intracellular trafficking. Recent in vitro and in vivo studies as well as the studies of human patient samples suggest that Abi1 may play an important role in breast cancer (BC) metastasis. To determine if Abi1 is deregulated in metastatic breast cancer cells, we compared the expression of Abi1 in a panel of human breast cancer cell lines exhibiting distinct metastatic properties. In comparison with low-metastatic ER+/PR+ BC lines MCF-7 and T47D and a non-transforming mammary epithelial cell line MCF-10A, two ER-BC lines CN34 and MDA 231 and their sublines selected by high metastatic potential to bone (231Bo), brain (231Br and CN34Br), and lung (231LM2) show significantly reduced Abi1 protein levels, with greater reduction found in highly metastatic sublines. It is unlikely that the down-regulation of Abi1 expression in these metastatic BC cells occurs at mRNA level, because RT-PCR analysis shows no significant difference in Abi1 mRNA levels among the cells analyzed. Interestingly, despite a reduction in protein level, the tyrosine phosphorylation of Abi1 was increased in CN34, MDA231, and their metastatic sublines compared to low-metastatic BC cells. The tyrosine phosphorylation of Abi1 is stimulated by epidermal growth factor (EGF) in these cells and Abi1 is recruited to EGF receptor (EGFR) upon EGF stimulation. The deregulation of Abi1 in metastatic BC cells is mediated by Abl tyrosine kinases, as the inhibition of Abl family kinases by imatinib not only attenuates EGF-stimulated Abi1 tyrosine phosphorylation but also rescue the down-regulation of Abi1 protein in metastatic BC cells.

These findings are consistent with a role of the EGFR-Abl-Abi1 signaling in BC metastasis. The studies suggest that this pathway may serve as a biomarker for diagnosis and/or prognosis of metastatic breast cancer. We have identified the tyrosine 213 in Abi1 as a major phosphorylation site stimulated by Abl kinases and have generated a unique conditional Abi1 depletion/re-expression system to dissect how the deregulation of the Abi1 signaling contributes to BC metastasis.

Citation Format: Jiang P, Tang H, Hogan H, Tate S, Ryan W, Paul L, Liu X, Zonghan D. Dissection of the Abl interactor 1 signaling in metastatic breast cancer cells [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-01-14.

Embolization of Intracranial Dural Arteriovenous Fistulas Using PHIL Liquid Embolic Agent in 26 Patients: A Multicenter Study

BACKGROUND AND PURPOSE

The introduction of liquid embolic agents has revolutionized endovascular approach to cranial vascular malformations. The aim of the study was to retrospectively assess the efficacy and safety of Precipitating Hydrophobic Injectable Liquid (PHIL), a new nonadhesive liquid embolic agent, in the treatment of patients with cranial dural arteriovenous fistulas. The primary end point was the rate of complete occlusion of dural arteriovenous fistulas. Secondary end points included the incidence of adverse events and clinical status at 3-month follow-up.

MATERIALS AND METHODS

This was a retrospective multicenter study. Twenty-six consecutive patients with dural arteriovenous fistulas (de novo or previously treated) treated by injection of PHIL only or with PHIL in combination with other embolization products (such as Onyx or detachable coils) were included in the study. Recruitment started in August 2014 and ended in September 2015.

RESULTS

Twenty-two (85%) patients were treated with PHIL only, with 3 patients treated with both PHIL and Onyx, and 1, with both PHIL and coils. Immediate complete angiographic occlusion was achieved in 20 (77%) patients. Of the 6 patients with residual fistulas, 3 were retreated with PHIL and 1 achieved angiographic cure. An adverse event was seen in 1 patient who developed worsening of preexisting ataxia due to acute thrombosis of the draining vein.

CONCLUSIONS

PHIL appears to be safe and effective for endovascular treatment of cranial dural arteriovenous fistulas. Short-term angiographic and clinical results are comparable with those of Onyx, with the added advantage of easier preparation and improved homogeneous cast visualization. The use of iodine as a radio-opacifier also produces considerably less artifacts on CT compared with tantalum-based embolic materials.

Transcobalamin 776C→G polymorphism is associated with peripheral neuropathy in elderly individuals with high folate intake

BACKGROUND

The 776C→G polymorphism of the vitamin B-12 transport protein transcobalamin gene (TCN2) (rs1801198; Pro259Arg) is associated with a lower holotranscobalamin concentration in plasma. This effect may reduce the availability of vitamin B-12 to tissues even when vitamin B-12 intake is adequate. Clinical outcomes associated with vitamin B-12 insufficiency could potentially be worsened by high folate intake.

OBJECTIVE

We determined the association of the TCN2 776C→G polymorphism and folate intake with peripheral neuropathy in elders with normal plasma concentrations of vitamin B-12.

DESIGN

Participants in this cross-sectional study (n = 171) were from a cohort of community-based, home-bound elderly individuals aged ≥60 y who underwent an evaluation by physicians including an assessment for peripheral neuropathy. Participants were administered food-frequency and general health status questionnaires, anthropometric measurements were taken, and a fasting blood sample from each subject was collected.

RESULTS

Odds of neuropathy were 3-fold higher for GG genotypes than for CC genotypes (OR: 3.33; 95% CI: 1.15, 9.64). When folate intake was >2 times the Recommended Dietary Allowance (800 μg), GG genotypes had 6.9-fold higher odds of neuropathy than CC genotypes (OR: 6.9; 95% CI: 1.31, 36.36). There was no difference between the genotypes in the odds of peripheral neuropathy when folate intake was ≤800 μg (OR: 1.5; 95% CI: 0.18, 12.33).

CONCLUSION

The TCN2 776C→G polymorphism is associated with increased odds of peripheral neuropathy in the elderly, even with a normal vitamin B-12 status, especially if their folate intake is >2 times the Recommended Dietary Allowance.

Interaction between excess folate and low vitamin B12 status

Current epidemiological evidence suggests that an imbalance of high folate status and low vitamin B12 status is associated with negative health outcomes in older adults and children. Such an imbalance during pregnancy also predisposes women to diabetes and their offspring to insulin resistance and adiposity and low birthweight. In older adults, vitamin B12 status can remain low despite adequate intake due to age-related decline in vitamin B12 absorption. Pregnant women are exposed to folic acid at varying doses depending on the prenatal care prescribed in different countries. This review summarizes the current knowledge on the interaction between folate and vitamin B12 and the associated health outcomes.

The effectiveness and satisfaction of web-based physiotherapy in people with spinal cord injury: a pilot randomised controlled trial

STUDY DESIGN

A pilot randomised controlled trial.

OBJECTIVES

The aims of this study were to evaluate the effectiveness and participant satisfaction of web-based physiotherapy in people with spinal cord injury (SCI).

SETTING

Community patients of a national spinal injury unit in a university teaching hospital, Scotland, UK.

METHODS

Twenty-four participants were recruited and randomised to receive 8 weeks of web-based physiotherapy (intervention), twice per week, or usual care (control). Individual exercise programmes were prescribed based on participants' abilities. The intervention was delivered via a website (www.webbasedphysio.com) and monitored and progressed remotely by the physiotherapist.

RESULTS

Participants logged on to the website an average of 1.4±0.8 times per week. Between-group differences, although not significant, were more pronounced for the 6-min walk test. Participants were positive about using web-based physiotherapy and stated that they would be happy to use it again and would recommend it to others. Overall, it was rated as either good or excellent.

CONCLUSIONS

Web-based physiotherapy was feasible and acceptable for people with SCI. Participants achieved good compliance with the intervention and rated the programme highly and beneficial for health and well-being at various states after injury. The results of this study warrant further work with a more homogeneous sample.

SPONSORSHIP

This study was funded by the Queen Elizabeth National Spinal Injuries Unit, Glasgow, UK.

A randomised trial of the cool pad pillow topper versus standard care for sleep disturbance and hot flushes in women on endocrine therapy for breast cancer

PURPOSE

Quality of life in women receiving adjuvant endocrine therapy for breast cancer (BC) may be impaired by hot flushes and night sweats. The cool pad pillow topper (CPPT) is a commercial product, promoted to improve quality of sleep disrupted by hot flushes. This study aimed to identify if the CPPT reduces severity of sleep disturbance by minimising effects of hot flushes.

METHODS

This randomised phase II trial, recruited women with BC, on adjuvant endocrine therapy, experiencing hot flushes and insomnia. Participants were randomised (stratified by baseline sleep efficiency score (SES) and menopausal status) to the intervention arm (CPPT + standard care) or control arm (standard care). Participants completed Hospital Anxiety and Depression Scale and Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaires and fortnightly sleep/hot flush diaries (where responses were averaged over 2-week periods). The primary endpoint was change in average SES from -2 to 0 weeks to 2 to 4 weeks.

RESULTS

Seventy-four pre- (68.9 %) and post-menopausal (31.1 %) women were recruited. Median age was 49.5 years. Endocrine therapies included tamoxifen (93.2 %). Median SES at weeks 2 to 4 improved in both arms but the increase on the intervention arm was almost twice that on the control arm (p = 0.024). There were significantly greater reductions in hot flushes and HADS depression in the intervention arm (p = 0.09 and p = 0.036, respectively). There were no significant differences in FACT-B or HADS anxiety.

CONCLUSION

This study supports the use of the CPPT as an aid to reduce sleep disturbance and the frequency/severity of hot flushes.

Evidence from a Randomized Trial That Exposure to Supplemental Folic Acid at Recommended Levels during Pregnancy Does Not Lead to Increased Unmetabolized Folic Acid Concentrations in Maternal or Cord Blood

BACKGROUND

Exposure to higher intakes of folic acid (FA) from fortified foods and supplements, although largely considered beneficial, is associated with unmetabolized FA in the circulation, which has raised some health concerns.

OBJECTIVE

The effect of supplemental FA at a dose of 400 μg/d during pregnancy on unmetabolized FA concentrations in maternal plasma and newborn cord blood plasma was investigated.

METHODS

A new analysis was performed of blood samples from participants in a randomized trial in pregnancy. Women aged 18-35 y, who had taken 400 μg FA/d as recommended in the first trimester, were recruited at the start of trimester 2 and randomly allocated to receive either 400 μg FA/d (n = 59) or a placebo (n = 67) throughout the second and third trimesters until delivery. Unmetabolized FA concentrations in maternal and cord blood samples were measured by LC-tandem MS analysis.

RESULTS

In response to the intervention from gestational week 14 through delivery, a higher proportion of women in the FA compared with the placebo group had detectable FA (≥0.27 nmol/L) in plasma, but the difference in concentrations was not statistically significant (mean ± SD: 0.44 ± 0.80 compared with 0.13 ± 0.49 nmol/L, P = 0.38). FA treatment throughout pregnancy resulted in higher cord blood plasma total folate (50.6 ± 20.1 compared with 34.5 ± 14.4 nmol/L; P = 0.004) and 5-methyltetrahydrofolate (50.4 ± 20.3 compared with 34.5 ± 14.4 nmol/L; P = 0.005) concentrations, but FA was detected only in 8 of 53 available cord blood samples, and the proportion of samples with detectable FA concentrations was similar in FA-treated and placebo groups.

CONCLUSIONS

Plasma concentrations of unmetabolized FA arising from supplemental FA at a dose of 400 μg/d, in addition to FA from fortified foods, were low or undetectable in mothers and newborns. The benefits for mothers and offspring of continuing FA supplementation beyond the first trimester of pregnancy can be achieved without posing any risk of increasing unmetabolized circulating FA, even in those already exposed to FA from fortified foods.

Unmetabolized Folic Acid in Prediagnostic Plasma and the Risk of Colorectal Cancer

Higher folate has been associated with a reduced colorectal cancer (CRC) risk, but excessive folate may promote tumor progression. The role of unmetabolized folic acid (UFA) from high folic acid consumption in carcinogenesis is largely unexplored. We evaluated prediagnostic plasma levels of UFA in relation to CRC risk in nested case-control studies (618 CRC case patients and 1207 matched control) with blood samples collected prior to folic acid fortification. UFA was detected in 21.4% of control UFA levels were not associated with CRC risk. Compared with undetectable levels, the multivariable relative risks (RRs) of CRC were 1.03 (95% confidence interval [CI] = 0.73 to 1.46) for less than 0.5 nmol/L and 1.12 (95% CI = 0.81 to 1.55) for 0.5 nmol/L or more (Ptrend = .32). A positive association between UFA levels and CRC risk was observed among men (RR = 1.57, 95% CI = 0.99 to 2.49 for ≥0.5 nmol/L vs undetectable, Pinteraction = .04), and a positive association was also observed among those with the methylene-tetrahydrofolate reductase (MTHFR) CT/TT genotype (RR = 2.20, 95% CI = 1.22 to 3.94 for ≥0.5 nmol/L vs undetectable, Pinteraction=0.02). In conclusion, prediagnostic plasma levels of UFA from the prefortification period were not associated with risk of CRC.