| 1. |
- Nägga, Katarina, 1962-, et al.
(författare)
-
Evaluation of factors of importance for clinical dementia diagnosis
- 2005
-
Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 19:5-6, s. 289-298
-
Tidskriftsartikel (refereegranskat)abstract
- Diagnosing clinical dementia is based on an assessment of different variables, such as the patient’s medical history, known risk factors, and biochemical features. Partial least squares discriminant analysis was used to evaluate variables of importance for diagnosing dementia in a clinical dementia population. Polymorphism for genotypes of glutathione S-transferase (GST) and sulfotransferase 1A1, hypothetically of importance in dementia disorders, was also included in the analysis. The study population consisted of 73 patients with Alzheimer’s disease (AD), 14 with mixed dementia, 75 patients with vascular dementia, and 28 control cases. We found that several of the variables, such as the presence of ApoE4 allele, high cerebrospinal fluid levels of total tau protein, low levels of β-amyloid<sub>(1–42)</sub>, and a low score on the Mini-Mental State Examination, facilitated a discrimination between the diagnoses compared with the controls. The different diagnoses overlapped. There were indications that genotypes of GSTs contributed to a subgrouping within AD.
|
|
| 2. |
- Dunstan, R. H., et al.
(författare)
-
Diverse characteristics of the urinary excretion of amino acids in humans and the use of amino acid supplementation to reduce fatigue and sub-health in adults
- 2017
-
Ingår i: Nutrition Journal. - : Springer Science and Business Media LLC. - 1475-2891. ; 16:19
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The excretion of amino acids in urine represents an important avenue for the loss of key nutrients. Some amino acids such as glycine and histidine are lost in higher abundance than others. These two amino acids perform important physiological functions and are required for the synthesis of key proteins such as haemoglobin and collagen. Methods: Stage 1 of this study involved healthy subjects(n = 151) who provided first of the morning urine samples and completed symptom questionnaires. Urine was analysed for amino acid composition by gas chromatography. Stage 2 involved a subset of the initial cohort (n = 37) who completed a 30 day trial of an amino acid supplement and subsequent symptom profile evaluation. Results: Analyses of urinary amino acid profiles revealed that three groups could be objectively defined from the 151 participants using k-means clustering. The amino acid profiles were significantly different between each of the clusters (Wilks' Lambda = 0.13, p < 0.0001). Cluster 1 had the highest loss of amino acids with histidine being the most abundant component. Cluster 2 had glycine present as the most abundant urinary amino acid and cluster 3 had equivalent abundances of glycine and histidine. Strong associations were observed between urinary proline concentrations and fatigue/pain scores (r =.56 to.83) for females in cluster 1, with several other differential sets of associations observed for the other clusters. Conclusions: Different phenotypic subsets exist in the population based on amino acid excretion characteristics found in urine. Provision of the supplement resulted in significant improvements in reported fatigue and sleep for 81% of the trial cohort with all females reporting improvements in fatigue.
|
|
| 3. |
- Dunstan, R. H., et al.
(författare)
-
Sex differences in amino acids lost via sweating could lead to differential susceptibilities to disturbances in nitrogen balance and collagen turnover
- 2017
-
Ingår i: Amino Acids. - : Springer Science and Business Media LLC. - 0939-4451 .- 1438-2199. ; 49:8, s. 1337-1345
-
Tidskriftsartikel (refereegranskat)abstract
- Fluid collected during sweating is enriched with amino acids derived from the skin's natural moisturising factors and has been termed "faux" sweat. Little is known about sex differences in sweat amino acid composition or whether faux sweat amino acid losses affect nitrogen balance. Faux sweat collected by healthy adults (n = 47) after exercise, and at rest by chronic fatigue patients, was analysed for amino acid composition. Healthy females had higher total amino acid concentrations in sweat (10.5 +/- 1.2 mM) compared with healthy males (6.9 +/- 0.9 mM). Females had higher levels of 13 amino acids in sweat including serine, alanine and glycine. Higher hydroxyproline and proline levels suggested greater collagen turnover in females. Modelling indicated that with conservative levels of exercise, amino acid losses in females via faux sweat were triple than those predicted for urine, whereas in males they were double. It was concluded that females were more susceptible to key amino acid loss during exercise and/or hot conditions. Females reporting chronic fatigue had higher levels of methionine in faux sweat than healthy females. Males reporting chronic fatigue had higher levels of numerous amino acids in faux sweat compared to healthy males. Higher amino acid loss in faux sweat associated with chronic fatigue could contribute to a hypometabolic state. Depending on activity levels, climatic conditions and gender, amino acid losses in sweat and skin leachate could influence daily protein turnover where periods of continuously high turnover could lead to a negative net nitrogen balance.
|
|
| 4. |
|
|
| 5. |
- Pinto, Rui Climaco, et al.
(författare)
-
Advantages of orthogonal inspection in chemometrics
- 2012
-
Ingår i: Journal of Chemometrics. - : Wiley. - 0886-9383 .- 1099-128X. ; 26:6, s. 231-235
-
Tidskriftsartikel (refereegranskat)abstract
- The demand for chemometrics tools and concepts to study complex problems in modern biology and medicine has prompted chemometricians to shift their focus away from a traditional emphasis on model predictive capacity toward optimizing information exchange via model interpretation for biological validation. The interpretation of projection-based latent variable models is not straightforward because of its confounding of different systematic variations in the model components. Over the last 15?years, this has spurred the development of orthogonal-based methods that are capable of separating the correlated variation (to Y) from the noncorrelated (orthogonal to Y) variations in a single model. Here, we aim to provide a conceptual explanation of the advantages of orthogonal variation inspection in the context of Partial Least Squares (PLS) in multivariate classification and calibration. We propose that by inspecting the orthogonal variation, both model interpretation and information quality are improved by enhancement of the resulting level of knowledge. Although the predictive capacity of PLS using orthogonal methods may be identical to that of PLS alone, the combined result can be superior when it comes to the model interpretation. By discussing theory and examples, several new advantages revealed by inspection of orthogonal variation are highlighted. Copyright (c) 2012 John Wiley & Sons, Ltd.
|
|
| 6. |
- Rüetschi, Ulla, 1962, et al.
(författare)
-
Identification of CSF biomarkers for frontotemporal dementia using SELDI-TOF.
- 2005
-
Ingår i: Experimental neurology. - : Elsevier BV. - 0014-4886. ; 196:2, s. 273-81
-
Tidskriftsartikel (refereegranskat)abstract
- This investigation describes the discovery of novel possible cerebrospinal fluid (CSF) biomarkers for frontotemporal dementia (FTD) using surface-enhanced laser desorption/ionization time-of-flight (SELDI-TOF) mass spectrometry (MS). Sixteen clinically diagnosed FTD patients and 12 non-demented controls were included in the study. CSF was collected and analyzed for protein expression by SELDI-TOF MS. The samples were analyzed on four different array surfaces using two different energy-absorbing molecules as matrices. In total each sample was subjected to eight different surface/matrix conditions. About 2000 protein peaks (mass/charge ratios) were detected. Forty-two peaks were differentially expressed in FTD (P < 0.01). After exclusion of peaks with low signal-to-noise ratio and/or poor resolution and peaks representing differentially charged proteins, 10 peaks remained, five of which were increased and five decreased in FTD cases compared to controls. Using partial least square discriminant analysis (PLS-DA), the combination of these biomarkers discriminated FTD from non-demented controls with a sensitivity of 94%, a specificity of 83% and an accuracy of 89%. Five of the peaks were purified further and identified by tandem MS as a fragment of neurosecretory protein VGF, transthyretin, S-cysteinylated transthyretin, truncated cystatin C and a fragment of chromogranin B. With use of these potential biomarkers, FTD can be distinguished from control subjects with high accuracy in this pilot study.
|
|
| 7. |
- Svelander, Cecilia, 1980, et al.
(författare)
-
Postprandial lipid and insulin responses among healthy, overweight men to mixed meals served with baked herring, pickled herring or baked, minced beef
- 2015
-
Ingår i: European Journal of Nutrition. - : Springer Science and Business Media LLC. - 1436-6207 .- 1436-6215. ; 54:6, s. 945-958
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim was to compare postprandial lipid, insulin and vitamin D responses after consumption of three otherwise identical meals served either with baked herring, pickled herring or with baked, minced beef. METHODS: Seventeen healthy, overweight men (mean age 58 years, BMI 26.4-29.5 kg/m2) consumed standardized lunches together with baked herring, pickled herring or baked, minced beef on three occasions in a crossover design. Blood samples were taken just before and up to 7 h after the meal. The postprandial response was measured as serum concentrations of triglycerides (TG), total cholesterol and lipoproteins (LDL, HDL and VLDL), insulin, 25-OH vitamin D and plasma fatty acid composition. RESULTS: There was no difference in postprandial lipid responses between the two herring meals, whereas a slower TG clearance was observed after the baked, minced beef meal. The 150 g servings of baked and pickled herring provided 3.3 and 2.8 g of long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), respectively, which was reflected in a substantial postprandial increase in plasma LC n-3 PUFA levels. The pickled herring contained 22 % sugar and consequently gave a higher insulin response compared with the other two meals. CONCLUSIONS: Both pickled and baked herring are good sources of LC n-3 PUFA in the diet, but the presence of sugar in pickled herring should be taken into consideration, especially if large amounts are consumed. The faster postprandial TG clearance after a meal with baked herring compared with baked beef supports previous studies on the beneficial effects of herring on cardiovascular health.
|
|
| 8. |
- Alreshidi, M. M., et al.
(författare)
-
Amino acids and proteomic acclimation of Staphylococcus aureus when incubated in a defined minimal medium supplemented with 5% sodium chloride
- 2019
-
Ingår i: Microbiologyopen. - : Wiley. - 2045-8827. ; 8:6
-
Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus is a versatile bacterium that can adapt to survive and grow in a wide range of salt concentrations. This study investigated whether the cells could mount a response to survive a challenge of 5% NaCl in a minimal incubation medium that would not support cell replication. Cells were grown in liquid culture, washed and then incubated for 90 min at 37 degrees C in a medium that contained only glycine and glucose as substrates in PBS plus trace elements. The control cells were compared with a treatment group which was incubated with an additional 5% NaCl. Significantly more glycine was taken up by the cells exposed to 5% NaCl compared with control cells, and both groups consumed 99% of the glucose supplied. The NaCl treated cells had significantly higher cytoplasmic levels of proline and glutamic acid as well as lower levels of alanine and methionine compared with the controls (p < 0.05). The levels of the two major cytoplasmic amino acids, aspartic acid and glycine, remained constant in control and treated cells. Proteomic analyses revealed that 10 proteins showed differential responses between the control and treatment groups. The reductions in proteins were primarily associated with processes of protein biosynthesis, pathogenicity, and cell adhesion. Since cell numbers remained constant during the incubation period in minimal medium, it was concluded that there was no cell division to support population growth. The results provided evidence that the cells in the minimal medium exposed to the NaCl treatment underwent in situ homeostatic changes to adjust to the new environmental conditions. It was proposed that this represented a phenotypic shift to form cells akin to small colony variants, with lower metabolic rates and lower levels of key proteins associated with pathogenicity.
|
|
| 9. |
- Alreshidi, M. M., et al.
(författare)
-
Changes in the Cytoplasmic Composition of Amino Acids and Proteins Observed in Staphylococcus aureus during Growth under Variable Growth Conditions Representative of the Human Wound Site
- 2016
-
Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:7
-
Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus is an opportunistic pathogen responsible for a high proportion of nosocomial infections. This study was conducted to assess the bacterial responses in the cytoplasmic composition of amino acids and ribosomal proteins under various environmental conditions designed to mimic those on the human skin or within a wound site: pH6-8, temperature 35-37 degrees C, and additional 0-5% NaCl. It was found that each set of environmental conditions elicited substantial adjustments in cytoplasmic levels of glutamic acid, aspartic acid, proline, alanine and glycine (P < 0.05). These alterations generated characteristic amino acid profiles assessed by principle component analysis (PCA). Substantial alterations in cytoplasmic amino acid and protein composition occurred during growth under conditions of higher salinity stress implemented via additional levels of NaCl in the growth medium. The cells responded to additional NaCl at pH 6 by reducing levels of ribosomal proteins, whereas at pH 8 there was an upregulation of ribosomal proteins compared with the reference control. The levels of two ribosomal proteins, L32 and S19, remained constant across all experimental conditions. The data supported the hypothesis that the bacterium was continually responding to the dynamic environment by modifying the proteome and optimising metabolic homeostasis.
|
|
| 10. |
- Alreshidi, M. M., et al.
(författare)
-
Metabolomic and proteomic responses of Staphylococcus aureus to prolonged cold stress
- 2015
-
Ingår i: Journal of Proteomics. - : Elsevier BV. - 1874-3919. ; 121, s. 44-55
-
Tidskriftsartikel (refereegranskat)abstract
- The high pathogenicity of Staphylococcus aureus is thought to be due to its extraordinary capacity to rapidly adapt to changes in environmental conditions. This study was carried out to investigate whether the cytoplasmic profiles of metabolites and proteins of Staphylococcus aureus were altered in response to prolonged exposure to cold stress. Metabolic profiling and proteomics were used to characterise alterations in cytoplasmic proteins and metabolites in cells from the mid-exponential phase of growth under ideal conditions at 37 degrees C and compared with equivalent cells exposed to prolonged cold stress for 2 weeks at 4 degrees C. Principle component analysis (PCA) of the metabolomic and proteomic data indicated that, at the mid-exponential phase of growth, prolonged cold stress conditions generated cells with different metabolite and protein profiles compared with those grown at 37 degrees C. Nine ribosomal proteins and citric acid were substantially elevated in the cytoplasmic fractions from the cells adapted to cold-stress but most amino acids showed a reduction in their concentration in cold-stressed samples. The data provided strong evidence supporting the hypothesis that specific changes in metabolic homeostasis and protein composition were critical to the adaptive processes required for survival under cold stress. Work in our laboratory has shown that prolonged exposure of Staphylococcus aureus to cold stress can result in the formation of small colony variants (SCVs) associated with significant alterations in the cell wall composition [8]. Further studies revealed that Staphylococcus aureus altered cell size and cell wall thickness in response to exposure to cold temperatures, alterations in pH and exposure to antibiotics [10]. The current study has utilised the prolonged exposure to cold stress as a model system to explore changes in the proteome and associated metabolic homeostasis following environmental challenges. The study provides an improved understanding of how Staphylococcus aureus adapts to the changing environment whilst in transition between human hosts. The results indicated an unexpected production of 9 ribosomal proteins and citric acid in response to cold stress suggesting specific survival roles for these proteins and citric acid as an adaptation mechanism for empowering survival under these conditions. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.
|
|
