Publications by authors named "Trent Bjorndahl"

Prion diseases are caused by the conversion of normal cellular prion proteins (PrP) into lethal prion aggregates. These prion aggregates are composed of proteinase K (PK) resistant fibrils and comparatively PK-sensitive oligomers. Currently there are no anti-prion pharmaceuticals available to treat or prevent prion disease.

View Article and Find Full Text PDF

Prion (PrP) diseases are neurodegenerative diseases characterized by the formation of β-sheet rich, insoluble and protease resistant protein deposits (called PrP) that occur throughout the brain. Formation of synthetic or in vitro PrP can occur through on-pathway toxic oligomers. Similarly, toxic and infectious oligomers identified in cell and animal models of prion disease indicate that soluble oligomers are likely intermediates in the formation of insoluble PrP.

View Article and Find Full Text PDF

Stillbirth remains a major problem in both developing and developed countries. Omics evaluation of stillbirth has been highlighted as a top research priority. To identify new putative first-trimester biomarkers in maternal serum for stillbirth prediction using metabolomics-based approach.

View Article and Find Full Text PDF

Introduction: Endometrial cancer (EC) is associated with metabolic disturbances including obesity, diabetes and metabolic syndrome. Identifying metabolite biomarkers for EC detection has a crucial role in reducing morbidity and mortality.

Objective: To determine whether metabolomic based biomarkers can detect EC overall and early-stage EC.

View Article and Find Full Text PDF

Prion diseases are fatal neurodegenerative disorders of the central nervous system characterized by the accumulation of a protease resistant form (PrP) of the cellular prion protein (PrP) in the brain. Two types of cellular prion (PrP) compounds have been identified that appear to affect prion conversion are known as Effective Binders (EBs) and Accelerators (ACCs). Effective binders shift the balance in favour of PrP, whereas Accelerators favour the formation of PrP.

View Article and Find Full Text PDF

Currently little is known about the underlying pathophysiology associated with SIDS, and no objective biomarkers exist for the accurate identification of those at greatest risk of dying from SIDS. Using targeted metabolomics, we aim to profile the medulla oblongata of infants who have died from SIDS (n = 16) and directly compare their biochemical profile with age matched controls. Combining data acquired using H NMR and targeted DI-LC-MS/MS, we have identified fatty acid oxidation as a pivotal biochemical pathway perturbed in the brains of those infants who have from SIDS (p = 0.

View Article and Find Full Text PDF

Background: There is strong evidence indicating that gut microbiota have the potential to modify, or be modified by the drugs and nutritional interventions that we rely upon. This study aims to characterize the compositional and functional effects of several nutritional, neutraceutical, and pharmaceutical cardiovascular disease interventions on the gut microbiome, through metagenomic and metabolomic approaches. Apolipoprotein-E-deficient mice were fed for 24 weeks either high-fat/cholesterol diet alone (control, HFC) or high-fat/cholesterol in conjunction with one of three dietary interventions, as follows: plant sterol ester (PSE), oat β-glucan (OBG) and bile salt hydrolase-active Lactobacillus reuteri APC 2587 (BSH), or the drug atorvastatin (STAT).

View Article and Find Full Text PDF

Huntington's disease (HD) is an autosomal neurodegenerative disorder affecting approximately 5-10 persons per 100,000 worldwide. The pathophysiology of HD is not fully understood but the age of onset is known to be highly dependent on the number of CAG triplet repeats in the huntingtin gene. Using (1)H NMR spectroscopy this study biochemically profiled 39 brain metabolites in post-mortem striatum (n=14) and frontal lobe (n=14) from HD sufferers and controls (n=28).

View Article and Find Full Text PDF

Background: Heart failure (HF) with preserved ejection fraction (HFpEF) is increasingly recognized as an important clinical entity. Preclinical studies have shown differences in the pathophysiology between HFpEF and HF with reduced ejection fraction (HFrEF). Therefore, we hypothesized that a systematic metabolomic analysis would reveal a novel metabolomic fingerprint of HFpEF that will help understand its pathophysiology and assist in establishing new biomarkers for its diagnosis.

View Article and Find Full Text PDF

Brassica villosa is a wild Brassica C genome species with very dense trichome coverage and strong resistance to many insect pests of Brassica oilseeds and vegetables. Transcriptome analysis of hairy B. villosa leaves indicated higher expression of several important trichome initiation genes compared with glabrous B.

View Article and Find Full Text PDF
Article Synopsis
  • The conversion of the cellular prion protein (PrP(C)) to its infectious isoform (PrP(Sc)) is key in prion diseases, with PrP(Sc) being the main infectious agent, but other cellular factors also play a significant role in this process.
  • Various in vitro systems using different chemical agents have been developed to promote PrP(C) conversion into PrP(Sc), although these methods often occur under non-natural conditions.
  • Recent research found that lipopolysaccharide (LPS), a component of gram-negative bacteria, can induce the conversion of PrP(C) to a β-rich isoform at nearly physiological conditions, especially when LPS concentration is above a certain threshold.
View Article and Find Full Text PDF

Objective: The objective of the study was to identify metabolomic markers in maternal first-trimester serum for the detection of fetal congenital heart defects (CHDs).

Study Design: Mass spectrometry (direct injection/liquid chromatography and tandem mass spectrometry) and nuclear magnetic resonance spectrometry-based metabolomic analyses were performed between 11 weeks' and 13 weeks 6 days' gestation on maternal serum. A total of 27 CHD cases and 59 controls were compared.

View Article and Find Full Text PDF

Prion-induced diseases are a global health concern. The lack of effective therapy and 100% mortality rates for such diseases have made the prion protein an important target for drug discovery. Previous NMR experimental work revealed that thiamine and its derivatives bind the prion protein in a pocket near the N-terminal loop of helix 1, and conserved intermolecular interactions were noted between thiamine and other thiamine-binding proteins.

View Article and Find Full Text PDF

Urine has long been a "favored" biofluid among metabolomics researchers. It is sterile, easy-to-obtain in large volumes, largely free from interfering proteins or lipids and chemically complex. However, this chemical complexity has also made urine a particularly difficult substrate to fully understand.

View Article and Find Full Text PDF

The Human Metabolome Database (HMDB) (www.hmdb.ca) is a resource dedicated to providing scientists with the most current and comprehensive coverage of the human metabolome.

View Article and Find Full Text PDF

Although highly conserved throughout evolution, the exact biological function of the prion protein is still unclear. In an effort to identify the potential biological functions of the prion protein we conducted a small-molecule screening assay using the Syrian hamster prion protein [shPrP(90-232)]. The screen was performed using a library of 149 water-soluble metabolites that are known to pass through the blood-brain barrier.

View Article and Find Full Text PDF

The residue-specific urea-induced unfolding patterns of recombinant prion proteins from different species (bovine, rabbit, mouse, and Syrian hamster) were monitored using high-resolution (1)H nuclear magnetic resonance (NMR) spectroscopy. Protein constructs of different lengths, and with and without a His tag attached at the N-terminus, were studied. The various species showed different overall sensitivities toward urea denaturation with stabilities in the following order: hamster ≤ mouse < rabbit < bovine protein.

View Article and Find Full Text PDF

Prions are believed to spontaneously convert from a native, monomeric highly helical form (called PrP(c)) to a largely β-sheet-rich, multimeric and insoluble aggregate (called PrP(sc)). Because of its large size and insolubility, biophysical characterization of PrP(sc) has been difficult, and there are several contradictory or incomplete models of the PrP(sc) structure. A β-sheet-rich, soluble intermediate, called PrP(β), exhibits many of the same features as PrP(sc) and can be generated using a combination of low pH and/or mild denaturing conditions.

View Article and Find Full Text PDF

Background: One-dimensional (1D) 1H nuclear magnetic resonance (NMR) spectroscopy is widely used in metabolomic studies involving biofluids and tissue extracts. There are several software packages that support compound identification and quantification via 1D 1H NMR by spectral fitting techniques. Because 1D 1H NMR spectra are characterized by extensive peak overlap or spectral congestion, two-dimensional (2D) NMR, with its increased spectral resolution, could potentially improve and even automate compound identification or quantification.

View Article and Find Full Text PDF

The human rhinovirus (HRV) is a positive sense RNA virus responsible for about 30% of "common colds". It relies on a 182 residue cysteine protease (3C) to proteolytically process its single gene product. Inhibition of this enzyme in vitro and in vivo has consistently demonstrated cessation of viral replication.

View Article and Find Full Text PDF

The structural determinants of type II' beta-turns were probed through a comprehensive CD, NMR, and molecular dynamics analysis of 10 specially designed beta-hairpin peptides. The peptide model used in this study is a synthetic, water-soluble, 14-residue cyclic analogue of gramicidin S which contains two well-defined type II' beta-turns connected by a highly stable, amphipathic, antiparallel beta-sheet. A variety of coded and noncoded amino acids were systematically substituted in one of the two type II' turns to analyze the effects of backbone chirality, side-chain steric restriction, and side-chain/side-chain interactions.

View Article and Find Full Text PDF