102 research outputs found

    Trans unsaturated fatty acids : a study of methodology and levels in New Zealand food fats including milkfat : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Biochemistry at Massey University, New Zealand

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    Trans fatty acids (TFAs) occur naturally in small amounts in foods such as milk, butter and tallow as a result of biohydrogenation by ruminant gut microflora. They are formed in much larger quantities during chemical hydrogenation of fats and oils. The relationship between dietary TFAs and blood cholesterol has been investigated over the last 30 years with equivocal results because of methodological limitations, including difficulties of quantifying the consumption of TFAs. The present study was conducted to investigate the methodologies used to quantify TFAs in fat samples. Two methodologies, based on infrared spectrophotometry and argentation-thin layer chromatography/gas chromatography (Ag-TLC/GC), were optimised for TFA quantification. Improvements in the infrared methods were made using a calibration standard made up with two non-trans components (stearin and olein) in order to mimic the fatty acid background in the samples. Further improvements were made using a spectral subtraction technique where the non-trans background spectrum was subtracted from the sample spectrum using Fourier-transform infrared spectrophotometry software. Results from the improved infrared methods were compared with TFA measurements by the more detailed Ag-TLC/GC method. The spectral subtraction technique for the methyl ester samples produced results that were closest to those of the Ag-TLC/GC method. This Ag-TLC/GC method gives information about the individual trans isomers (C18:1 trans positional isomers and C18:2 and C18:3 trans isomers) that is not available by infrared. The present study was also conducted to determine, as accurately as possible, the TFA content in 18 manufactured foods commonly available in New Zealand using the TFA methods mentioned above. The TFA contents in some of the foods determined by the Ag-TLC/GC method were, margarine (15.43-15.57%), butter (6.58%), milk (5.26-6.03%), meat patties (3.42%), plain sweet biscuits (3.65%) and white bread (4.41 %). Using these TFA data and the food consumption data from a Life in New Zealand (Horwarth et al., 1991), the estimated TFA intakes in the average New Zealand diet were approximately 3.99 and 5.75 g/person/day for females and males respectively. These figures were similar to or lower than those estimated for Northern Hemisphere countries. The predominant TFA isomer in the New Zealand diet was identified as the C18:1 Δ11t positional isomer (30-33%). Further studies were made on the total TFA content in New Zealand milkfat. These studies indicated that the total TFA levels in New Zealand milkfat were influenced by seasonal variations, with the highest TFA content recorded in spring (September, 6.7%) and the lowest in summer (January, 5.3%). The C18:1 Δ11t isomer was found to be the predominant isomer in milkfat, making up 49-60% of the total TFA. Similar ranges were observed for several overseas butter samples. However, major differences were observed with the distribution of the C18:1 trans positional isomers. These differences are currently suspected to be influenced by the feed and animal husbandry methods used in some Northern Hemisphere countries, where cows are mainly grain fed in the winter months. The seasonal variation of TFAs in New Zealand butter and possible effects of feed and animal husbandry methods on the C18:1 trans positional isomer distribution are important factors that the New Zealand dairy industry could exploit for the production of low trans milkfat and/or other dairy products in which the levels of specific trans isomers implicated to be "harmful" to humans could be minimised. Margarines display a trans isomer distribution that is quite distinct from that of butter. Unlike milkfat where the predominant trans isomer is C18:1 Δ11t, in margarines and hydrogenated fats and oils the positional isomers show a normal distribution around the C18:1 Δ10t-11t isomers. The predominant isomers for the margarines analysed in this study were Δ9t-Δ12t (90%) with the polyunsaturated C18:2 and C18:3 trans making up less than 2%. The distinct distribution of C18:1 trans positional isomers could serve as an additional tool for the identification of animal or hydrogenated vegetable oils used in food fats

    Maternal Serum and Breast Milk Vitamin D Levels: Findings from the Universiti Sains Malaysia Pregnancy Cohort Study

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    Background: Vitamin D deficiency has become a global health issue in pregnant women. This study aimed to assess the adequacy of maternal vitamin D status by measuring maternal serum and breast milk 25-hydroxyvitamin D [25(OH)D] levels and to determine the association between maternal serum and milk 25(OH)D levels. Methods: Data was obtained from the Universiti Sains Malaysia Pregnancy Cohort Study. This study was conducted from April 2010 to December 2012 in the state of Kelantan, Malaysia. Blood samples from pregnant women aged 19 to 40 years were drawn in the second and third trimesters of pregnancy, while breast milk samples at delivery, 2, 6 and 12 months postpartum were collected to analyze for 25(OH)D levels. A total of 102 pregnant women were included in the analysis. Results: Vitamin D deficiency [25(OH)D ,50 nmol/L] was detected in 60% and 37% of women in the second and third trimesters of pregnancy, respectively. There were 6% and 23% of women who reached normal level of vitamin D status in the second trimester and the third trimester, respectively. Multivitamin intakes during pregnancy were significantly associated with higher serum 25(OH)D levels in the second trimester (b = 9.16, p = 0.005) and the third trimester (b = 13.65, p = 0.003). 25(OH)D levels in breast milk during the first year of lactation ranged from 1.01 to 1.26 nmol/L. Higher maternal serum 25(OH)D level in the second trimester of pregnancy was associated with an elevated level of 25(OH)D in breast milk at delivery (b = 0.002, p = 0.026). Conclusions: This study shows that high proportions of Malay pregnant women are at risk of vitamin D deficiency. Maternal vitamin D status in the second trimester of pregnancy was found to influence vitamin D level in breast milk at delivery

    A kinetic equation for economic value estimation with irrationality and herding

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    A kinetic inhomogeneous Boltzmann-type equation is proposed to model the dynamics of the number of agents in a large market depending on the estimated value of an asset and the rationality of the agents. The interaction rules take into account the interplay of the agents with sources of public information, herding phenomena, and irrationality of the individuals. In the formal grazing collision limit, a nonlinear nonlocal Fokker-Planck equation with anisotropic (or incomplete) diffusion is derived. The existence of global-in-time weak solutions to the Fokker-Planck initial-boundary-value problem is proved. Numerical experiments for the Boltzmann equation highlight the importance of the reliability of public information in the formation of bubbles and crashes. The use of Bollinger bands in the simulations shows how herding may lead to strong trends with low volatility of the asset prices, but eventually also to abrupt corrections

    Retinoids Regulate the Formation and Degradation of Gap Junctions in Androgen-Responsive Human Prostate Cancer Cells

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    The retinoids, the natural or synthetic derivatives of Vitamin A (retinol), are essential for the normal development of prostate and have been shown to modulate prostate cancer progression in vivo as well as to modulate growth of several prostate cancer cell lines. 9-cis-retinoic acid and all-trans-retinoic acid are the two most important metabolites of retinol. Gap junctions, formed of proteins called connexins, are ensembles of intercellular channels that permit the exchange of small growth regulatory molecules between adjoining cells. Gap junctional communication is instrumental in the control of cell growth. We examined the effect of 9-cis-retinoic acid and all-trans retinoic acid on the formation and degradation of gap junctions as well as on junctional communication in an androgen-responsive prostate cancer cell line, LNCaP, which expressed retrovirally introduced connexin32, a connexin expressed by the luminal cells and well-differentiated cells of prostate tumors. Our results showed that 9-cis-retinoic acid and all-trans retinoic acid enhanced the assembly of connexin32 into gap junctions. Our results further showed that 9-cis-retinoic acid and all-trans-retinoic acid prevented androgen-regulated degradation of gap junctions, post-translationally, independent of androgen receptor mediated signaling. Finally, our findings showed that formation of gap junctions sensitized connexin32-expressing LNCaP cells to the growth modifying effects of 9-cis-retinoic acid, all-trans-retinoic acid and androgens. Thus, the effects of retinoids and androgens on growth and the formation and degradation of gap junctions and their function might be related to their ability to modulate prostate growth and cancer

    Quantitative proteomics of delirium cerebrospinal fluid

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    Delirium is a common cause and complication of hospitalization in older people, being associated with higher risk of future dementia and progression of existing dementia. However relatively little data are available on which biochemical pathways are dysregulated in the brain during delirium episodes, whether there are protein expression changes common among delirium subjects and whether there are any changes which correlate with the severity of delirium. We now present the first proteomic analysis of delirium cerebrospinal fluid (CSF), and one of few studies exploring protein expression changes in delirium. More than 270 proteins were identified in two delirium cohorts, 16 of which were dysregulated in at least 8 of 17 delirium subjects compared with a mild Alzheimer's disease neurological control group, and 31 proteins were significantly correlated with cognitive scores (mini-mental state exam and acute physiology and chronic health evaluation III). Bioinformatics analyses revealed expression changes in several protein family groups, including apolipoproteins, secretogranins/chromogranins, clotting/fibrinolysis factors, serine protease inhibitors and acute-phase response elements. These data not only provide confirmatory evidence that the inflammatory response is a component of delirium, but also reveal dysregulation of protein expression in a number of novel and unexpected clusters of proteins, in particular the granins. Another surprising outcome of this work is the level of similarity of CSF protein profiles in delirium patients, given the diversity of causes of this syndrome. These data provide additional elements for consideration in the pathophysiology of delirium as well as potential biomarker candidates for delirium diagnosis

    Physical activity for women with breast cancer after adjuvant therapy

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    © 2018 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. Background: Women with a diagnosis of breast cancer may experience short- and long-term disease and treatment-related adverse physiological and psychosocial outcomes. These outcomes can negatively impact prognosis, health-related quality of life (HRQoL), and psychosocial and physical function. Physical activity may help to improve prognosis and may alleviate the adverse effects of adjuvant therapy. Objectives: To assess effects of physical activity interventions after adjuvant therapy for women with breast cancer. Search methods: We searched the Cochrane Breast Cancer Group (CBCG) Specialised Registry, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Physiotherapy Evidence Database (PEDro), SPORTDiscus, PsycINFO, ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform, on 18 September 2015. We also searched OpenGrey and Healthcare Management Information Consortium databases. Selection criteria: We searched for randomised and quasi-randomised trials comparing physical activity interventions versus control (e.g. usual or standard care, no physical activity, no exercise, attention control, placebo) after adjuvant therapy (i.e. after completion of chemotherapy and/or radiation therapy, but not hormone therapy) in women with breast cancer. Data collection and analysis: Two review authors independently selected studies, assessed risk of bias, and extracted data. We contacted trial authors to ask for additional information when needed. We calculated an overall effect size with 95% confidence intervals (CIs) for each outcome and used GRADE to assess the quality of evidence for the most important outcomes. Main results: We included 63 trials that randomised 5761 women to a physical activity intervention (n = 3239) or to a control (n = 2524). The duration of interventions ranged from 4 to 24 months, with most lasting 8 or 12 weeks (37 studies). Twenty-eight studies included aerobic exercise only, 21 involved aerobic exercise and resistance training, and seven used resistance training only. Thirty studies described the comparison group as usual or standard care, no intervention, or control. One-fifth of studies reported at least 20% intervention attrition and the average physical activity adherence was approximately 77%. No data were available on effects of physical activity on breast cancer-related and all-cause mortality, or on breast cancer recurrence. Analysis of immediately postintervention follow-up values and change from baseline to end of intervention scores revealed that physical activity interventions resulted in significant small-to-moderate improvements in HRQoL (standardised mean difference (SMD) 0.39, 95% CI 0.21 to 0.57, 22 studies, 1996 women; SMD 0.78, 95% CI 0.39 to 1.17, 14 studies, 1459 women, respectively; low-quality evidence), emotional function (SMD 0.21, 95% CI 0.10 to 0.32, 26 studies, 2102 women, moderate-quality evidence; SMD 0.31, 95% CI 0.09 to 0.53, 15 studies, 1579 women, respectively; low-quality evidence), perceived physical function (SMD 0.33, 95% CI 0.18 to 0.49, 25 studies, 2129 women; SMD 0.60, 95% CI 0.23 to 0.97, 13 studies, 1433 women, respectively; moderate-quality evidence), anxiety (SMD -0.57, 95% CI -0.95 to -0.19, 7 studies, 326 women; SMD -0.37, 95% CI -0.63 to -0.12, 4 studies, 235 women, respectively; low-quality evidence), and cardiorespiratory fitness (SMD 0.44, 95% CI 0.30 to 0.58, 23 studies, 1265 women, moderate-quality evidence; SMD 0.83, 95% CI 0.40 to 1.27, 9 studies, 863 women, respectively; very low-quality evidence). Investigators reported few minor adverse events. Small improvements in physical activity interventions were sustained for three months or longer postintervention in fatigue (SMD -0.43, 95% CI -0.60 to -0.26; SMD -0.47, 95% CI -0.84 to -0.11, respectively), cardiorespiratory fitness (SMD 0.36, 95% CI 0.03 to 0.69; SMD 0.42, 95% CI 0.05 to 0.79, respectively), and self-reported physical activity (SMD 0.44, 95% CI 0.17 to 0.72; SMD 0.51, 95% CI 0.08 to 0.93, respectively) for both follow-up values and change from baseline scores. However, evidence of heterogeneity across trials was due to variation in intervention components (i.e. mode, frequency, intensity, duration of intervention and sessions) and measures used to assess outcomes. All trials reviewed were at high risk of performance bias, and most were also at high risk of detection, attrition, and selection bias. In light of the aforementioned issues, we determined that the evidence was of very low, low, or moderate quality. Authors' conclusions: No conclusions regarding breast cancer-related and all-cause mortality or breast cancer recurrence were possible. However, physical activity interventions may have small-to-moderate beneficial effects on HRQoL, and on emotional or perceived physical and social function, anxiety, cardiorespiratory fitness, and self-reported and objectively measured physical activity. The positive results reported in the current review must be interpreted cautiously owing to very low-to-moderate quality of evidence, heterogeneity of interventions and outcome measures, imprecision of some estimates, and risk of bias in many trials. Future studies with low risk of bias are required to determine the optimal combination of physical activity modes, frequencies, intensities, and durations needed to improve specific outcomes among women who have undergone adjuvant therapy.Published versio
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