235 research outputs found
NMR protocol for determination of oxidation susceptibility of serum lipids and application of the protocol to a chocolate study
A protocol for determination of oxidation susceptibility of serum lipids based on proton nuclear magnetic resonance (1H NMR) spectroscopy is presented and compared to the commonly used spectrophotometric method. Even though there are methodological differences between these two methods, the NMR-based oxidation susceptibility correlates well (r2 = 0.73) with the lag time determined spectrophotometrically. In addition to the oxidizability of serum lipids, the NMR method provides also information about the lipid profile. The NMR oxidation assay was applied to the chocolate study including fasting serum samples (n = 45) from subjects who had consumed white (WC), dark (DC) or high-polyphenol chocolate (HPC) daily for 3 weeks. The oxidation susceptibility of serum lipids decreased in the HPC group, and there was a significant difference between the WC and HPC groups (P = 0.031). According to the random forest analysis, the consumption of the HPC chocolate induced changes to the amounts of HDL, phosphatidylcholine, sphingomyelin, and nervonic, docosahexaenoic and myristic acids. Furthermore, arachidonic, docosahexaenoic, docosapentaenoic and palmitic acids, gamma-glutamyl transferase, hemoglobin, HDL, phosphatidylcholine and choline containing phospholipids explained about 60% of the oxidation susceptibility values
Association of height and pubertal timing with lipoprotein subclass profile: exploring the role of genetic and environmental effects
Objectives: Little is known about the relationship between growth and lipoprotein profile. We aimed to analyze common genetic and environmental factors in the association of height from late childhood to adulthood and pubertal timing with serum lipid and lipoprotein subclass profile.
Methods: A longitudinal cohort of Finnish twin pairs (FinnTwin12) was analysed using self-reported height at 11-12, 14, 17 years and measured stature at adult age (21-24 years). Data were available for 719 individual twins including 298 complete pairs. Serum lipids and lipoprotein subclasses were measured by proton nuclear magnetic resonance spectroscopy. Multivariate variance component models for twin data were fitted. Cholesky decomposition was used to partition the phenotypic covariation among traits into additive genetic and unique environmental correlations.
Results: In men, the strongest associations for both adult height and puberty were observed with total cholesterol, low-density lipoprotein cholesterol, intermediate-density lipoprotein cholesterol and low-density lipoprotein particle subclasses (max. r = -0.19). In women, the magnitude of the correlations was weaker (max. r = -0.13). Few associations were detected between height during adolescence and adult lipid profile. Early onset of puberty was related to an adverse lipid profile, but delayed pubertal development in girls was associated with an unfavorable profile, as well. All associations were mediated mainly by additive genetic factors, but unique environmental effects cannot be disregarded.
Conclusions: Early puberty and shorter adult height relate to higher concentrations of atherogenic lipids and lipoprotein particles in early adulthood. Common genetic effects behind these phenotypes substantially contribute to the observed associations
Tolerability of ORM-12741 and effects on episodic memory in patients with Alzheimer's disease
Introduction
ORM-12741 is a novel selective antagonist of alpha-2C adrenoceptors. This trial evaluated the safety and efficacy of ORM-12741 in patients with Alzheimer's disease (AD).
Methods
A randomized, double-blind, placebo-controlled, exploratory phase 2a trial was conducted in 100 subjects with AD and neuropsychiatric symptoms. Participants were randomized to receive one of two flexible doses of ORM-12741 (30–60 mg or 100–200 mg) or placebo b.i.d. for 12 weeks in addition to standard therapy with cholinesterase inhibitors. Efficacy was assessed primarily with the Cognitive Drug Research (CDR) computerized assessment system and secondarily with the Neuropsychiatric Inventory (NPI).
Results
A statistically significant treatment effect was seen in one of the four primary CDR system end points, Quality of Episodic Memory (P = .030; not adjusted for multiple comparisons), favoring ORM-12741 over placebo. NPI caregiver distress scores also favored ORM-12741 (P = .034). ORM-12741 was well tolerated.
Discussion
This is the first clinical trial providing evidence on an acceptable safety profile for ORM-12741 in patients with AD and neuropsychiatric symptoms. In addition, the trial provided hints of potential therapeutic benefit, primarily on episodic memory, in this patient population
1H NMR metabonomics approach to the disease continuum of diabetic complications and premature death
Peer reviewe
Proceedings of Seminar on Network Protocols in Operating Systems
The Linux networking stack tends to evolve rapidly, and while there are some excellent documentation written in the past, most of the past documentation gotten (at least partially) outdated over time. The seminar on Network Protocols in Operating Systems was arranged in Aalto University, fall 2012, Department of Communications and Networking to gain a better understanding of the current status of the networking implementation in the Linux kernel. The seminar had 10 participants and each participant was assigned a module from the Linux networking implementation, on which a short paper was to be written. This publications contain the final output of this work. The papers included in the publication are:
Kurnikov, Arseny: Linux kernel application interface.
Jaakkola, Antti: Implementation of transmission control protocol in Linux.
Arianfar, Somaya: TCP’s congestion control implementation in Linux kernel.
Budigere, Karthik: Linux implementation study of stream control transmission protocol.
Khattak, Fida Ullah: The IPv4 implementation of Linux kernel stack.
Boye, Magnus: Netfilter connection tracking and NAT implementation.
Korhonen, Jouni: Mobile IPv6 Linux kernel and user space.
Soininen, Jonne: Device agnostic network interface.
Kalliola, Aapo: Network device drivers in Linux.
Varis, Nuutti: Anatomy of a Linux bridge
metaCCA : summary statistics-based multivariate meta-analysis of genome-wide association studies using canonical correlation analysis
Motivation: A dominant approach to genetic association studies is to perform univariate tests between genotype-phenotype pairs. However, analyzing related traits together increases statistical power, and certain complex associations become detectable only when several variants are tested jointly. Currently, modest sample sizes of individual cohorts, and restricted availability of individual-level genotype-phenotype data across the cohorts limit conducting multivariate tests. Results: We introduce metaCCA, a computational framework for summary statistics-based analysis of a single or multiple studies that allows multivariate representation of both genotype and phenotype. It extends the statistical technique of canonical correlation analysis to the setting where original individual-level records are not available, and employs a covariance shrinkage algorithm to achieve robustness. Multivariate meta-analysis of two Finnish studies of nuclear magnetic resonance metabolomics by metaCCA, using standard univariate output from the program SNPTEST, shows an excellent agreement with the pooled individual-level analysis of original data. Motivated by strong multivariate signals in the lipid genes tested, we envision that multivariate association testing using metaCCA has a great potential to provide novel insights from already published summary statistics from high-throughput phenotyping technologies.Peer reviewe
Abdominal obesity and circulating metabolites : A twin study approach
Objective. To investigate how obesity, insulin resistance and low-grade inflammation link to circulating metabolites, and whether the connections are due to genetic or environmental factors. Subjects and methods. Circulating serum metabolites were determined by proton NMR spectroscopy. Data from 1368 (531 monozygotic (MZ) and 837 dizygotic (DZ)) twins were used for bivariate twin modeling to derive the genetic (r(g)) and environmental (re) correlations between waist circumference (WC) and serum metabolites. Detailed examination of the associations between fat distribution (DEXA) and metabolic health (HOMA-IR, CRP) was performed among 286 twins including 33 BMI-discordant MZ pairs (intrapair BMI difference >= 3 kg/m(2)). Results. Fat, especially in the abdominal area (i.e. WC, android fat % and android to gynoid fat ratio), together with HOMA-IR and CRP correlated significantly with an atherogenic lipoprotein profile, higher levels of branched-chain (BCAA) and aromatic amino acids, higher levels of glycoprotein, and a more saturated fatty acid profile. In contrast, a higher proportion of gynoid to total fat associated with a favorable metabolite profile. There was a significant genetic overlap between WC and several metabolites, most strongly with phenylalanine (r(g) = 0.40), glycoprotein (r(g) = 0.37), serum triglycerides (r(g) = 0.36), BCAAs (r(g) = 0.30-0.40), HDL particle diameter (r(g) = -0.33) and HDL cholesterol (r(g) = -0.30). The effect of acquired obesity within the discordant MZ pairs was particularly strong for atherogenic lipoproteins. Conclusions. A wide range of unfavorable alterations in the serum metabolome was associated with abdominal obesity, insulin resistance and low-grade inflammation. Twin modeling and obesity-discordant twin analysis suggest that these associations are partly explained by shared genes but also reflect mechanisms independent of genetic liability. (C) 2015 Elsevier Inc. All rights reserved.Peer reviewe
Metabolic profiling of fatty liver in young and middle-aged adults : Cross-sectional and prospective analyses of the Young Finns Study
Nonalcoholic fatty liver is associated with obesity-related metabolic disturbances, but little is known about the metabolic perturbations preceding fatty liver disease. We performed comprehensive metabolic profiling to assess how circulating metabolites, such as lipoprotein lipids, fatty acids, amino acids, and glycolysis-related metabolites, reflect the presence of and future risk for fatty liver in young adults. Sixty-eight lipids and metabolites were quantified by nuclear magnetic resonance metabolomics in the population-based Young Finns Study from serum collected in 2001 (n = 1,575), 2007 (n = 1,509), and 2011 (n = 2,002). Fatty liver was diagnosed by ultrasound in 2011 when participants were aged 34-49 years (19% prevalence). Cross-sectional associations as well as 4-year and 10-year risks for fatty liver were assessed by logistic regression. Metabolites across multiple pathways were strongly associated with the presence of fatty liver (P <0.0007 for 60 measures in age-adjusted and sex-adjusted cross-sectional analyses). The strongest direct associations were observed for extremely large very-low-density lipoprotein triglycerides (odds ratio [OR] = 4.86 per 1 standard deviation, 95% confidence interval 3.48-6.78), other very-low-density lipoprotein measures, and branched-chain amino acids (e.g., leucine OR = 2.94, 2.51-3.44). Strong inverse associations were observed for high-density lipoprotein measures, e.g., high-density lipoprotein size (OR = 0.36, 0.30-0.42) and several fatty acids including omega-6 (OR = 0.37, 0.32-0.42). The metabolic associations were attenuated but remained significant after adjusting for waist, physical activity, alcohol consumption, and smoking (P <0.0007). Similar aberrations in the metabolic profile were observed already 10 years before fatty liver diagnosis. Conclusion: Circulating lipids, fatty acids, and amino acids reflect fatty liver independently of routine metabolic risk factors; these metabolic aberrations appear to precede the development of fatty liver in young adults. (Hepatology 2017;65:491-500).Peer reviewe
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