530 research outputs found
Ontogenetic and temporal variability in the fat content and fatty acid composition of Atlantic herring (Clupea harengus) from the Bay of Fundy, Canada
Atlantic herring (Clupea harengus) is an ecologically and
economically valuable species in many food webs, yet surprisingly little is known about the variation in the nutritional quality of these fish. Atlantic herring collected from 2005 through 2008 from the Bay of Fundy, Canada, were examined for variability in their nutritional quality by using total lipid content (n=889) and fatty acid composition (n=551) as proxies for nutritional value. A
significant positive relationship was found between fish length and total lipid content. Atlantic herring also had significantly different fatty acid signatures by age. Fish from 2005 had significantly lower total lipid content than fish from 2006 through 2008, and all years had significantly different fatty acid signatures. Summer
fish were significantly fatter than winter fish and had significantly different fatty acid signatures. For all comparisons (ontogenetic, annual, and seasonal) percent concentrations of omega-3, -6, and long-chain monounsaturated fatty acids were the most important for distinguishing between the fatty acid signatures of fish. This study underscores the importance of quantifying variation in prey quality synoptically with prey quantity
in food webs over ontogenetic and temporal scales when evaluating the effect of prey nutritional quality on
predators and on modeling trophic dynamics
Long-term physical activity: an exogenous risk factor for sporadic amyotrophic lateral sclerosis?
OBJECTIVES: To conduct a geographically defined, UK-based case-control study, to examine any association between physical activity (PA) and amyotrophic lateral sclerosis (ALS). METHODS: A novel historical PA questionnaire was designed, validated, and subsequently administered in individual face-to-face interviews of 175 newly diagnosed sporadic ALS cases and 317 age- and sex-matched community controls. Historical PA energy expenditure and time spent in vigorous-intensity PA were derived from questionnaire data and compared between cases and controls. RESULTS: Participation in an extra 10kJ/kg/day of PA (equivalent to approximately 45minutes brisk walking) was consistently associated with an increased risk of ALS, with the strongest association observed for adulthood exercise-related PA (OR 1.47, 95% CI 1.10-1.97). An extra 10mins/day of vigorous PA was also associated with the odds of ALS (OR 1.03, 95% CI 1·01-1·05). Results were slightly attenuated following adjustment for smoking and educational attainment. CONCLUSIONS: To our knowledge this is the first study to demonstrate a positive association between ALS and PA participation using a specifically designed and validated historical PA questionnaire. Despite the well-established health benefits of PA, a high activity lifestyle may also be associated with elevated risk of ALS. Large-scale prospective studies in the future may help to confirm this association.This study was funded by a Medical Research Council/Motor Neurone Disease Association Lady Edith Wolfson Fellowship.This is the final version of the article. It first appeared from Taylor and Francis via https://doi.org/10.3109/21678421.2016.115457
Long-term physical activity: an exogenous risk factor for sporadic amyotrophic lateral sclerosis?
Objectives: To conduct a geographically defined, UK-based case-control study, to examine any association between physical activity (PA) and amyotrophic lateral sclerosis (ALS).
Methods: A novel historical PA questionnaire was designed, validated, and subsequently administered in individual face-to-face interviews of 175 newly diagnosed sporadic ALS cases and 317 age- and sex-matched community controls. Historical PA energy expenditure and time spent in vigorous-intensity PA were derived from questionnaire data and compared between cases and controls.
Results: Participation in an extra 10kJ/kg/day of PA (equivalent to approximately 45minutes brisk walking) was consistently associated with an increased risk of ALS, with the strongest association observed for adulthood exercise-related PA (OR 1.47, 95% CI 1.10-1.97). An extra 10mins/day of vigorous PA was also associated with the odds of ALS (OR 1.03, 95% CI 1·01-1·05). Results were slightly attenuated following adjustment for smoking and educational attainment.
Conclusions: To our knowledge this is the first study to demonstrate a positive association between ALS and PA participation using a specifically designed and validated historical PA questionnaire. Despite the well-established health benefits of PA, a high activity lifestyle may also be associated with elevated risk of ALS. Large-scale prospective studies in the future may help to confirm this association.This study was funded by a Medical Research Council/Motor Neurone Disease Association Lady Edith Wolfson Fellowship.This is the final version of the article. It first appeared from Taylor and Francis via https://doi.org/10.3109/21678421.2016.115457
Sleep duration and cardiometabolic risk factors among individuals with type 2 diabetes.
OBJECTIVE: To examine the association between sleep duration and cardiometabolic risk factors among individuals with recently diagnosed type 2 diabetes (n = 391). METHODS: Sleep duration was derived using a combination of questionnaire and objective heart rate and movement sensing in the UK ADDITION-Plus study (2002-2007). Adjusted means were estimated for individual cardiometabolic risk factors and clustered cardiometabolic risk (CCMR) by five categories of sleep duration. RESULTS: We observed a J-shaped association between sleep duration and CCMR - individuals sleeping 7 to <8 h had a significantly better CCMR profile than those sleeping ≥9 h. Independent of physical activity and sedentary time, individuals sleeping 7 to <8 h had lower triacylglycerol (0.62 mmol/l (0.29, 1.06)) and higher high-density lipoprotein (HDL)-cholesterol levels (0.23 mmol/l (0.16, 0.30)) compared with those sleeping ≥9 h, and a lower waist circumference (7.87 cm (6.06, 9.68)) and body mass index (BMI) (3.47 kg/m(2) (2.69, 4.25)) than those sleeping <6 h. Although sleeping 7 to <8 h was associated with lower levels of systolic and diastolic blood pressure, HbA1c, total cholesterol, and low-density lipoprotein (LDL)-cholesterol, these associations were not statistically significant. CONCLUSIONS: Sleep duration has a J-shaped association with CCMR in individuals with diabetes, independent of potential confounding. Health promotion interventions might highlight the importance of adequate sleep in this high-risk population.The trial is supported by the Wellcome Trust, the Medical Research Council, Diabetes UK and National Health Service R&D support funding. SJG was a member of the National Institute for Health Research (NIHR) School for Primary Care Research. The General Practice and Primary Care Research Unit was supported by NIHR Research funds. SJG received support from the Department of Health NIHR Programme Grant funding scheme [RP-PG-0606-1259]. ATP is supported by the NIHR Biomedical Research Centre at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.sleep.2014.10.00
Pulmonary Embolism in a Woman Taking Oral Contraceptives and Valdecoxib
A 25-y-old woman, who had been on an oral contraceptive pill for 3 years, presented with pulmonary embolism. One month prior to presentation she had been started on valdecoxib for neck pain
Identification of chloroplast DNA insertions in nuclear chromosomes of maize B73 line using the FISH procedure
Abstract only availableIt is known that chloroplast DNA can incorporate itself into the nuclear genome of plants. However, the sites of chloroplast (ct) DNA integration into chromosomes of maize have not yet been analyzed. This project is the first attempt to find the location of the ctDNA on the maize chromosomes. Fluorescent in situ hybridization is a technique that has proved useful in karyotyping and chromosomal mapping in maize. The FISH procedure is being used in this study to discover the location of the ctDNA in the nuclear genome of the inbred line B37. In order to develop ctDNA “probes” for FISH analysis, we have used the polymerase chain reaction (PCR) to produce fragments of ctDNA. Primers were chosen to amplify fragments of 10 kb or larger. The amplified DNAs were purified and labeled with fluorescent dyes and these probes were subsequently hybridized to chromosomes. The probes recognize and bind to the corresponding DNA sequences within the chromosomes. Root tip cells were used to prepare the slides for hybridization. Because the cells are collected during the metaphase stage of division, the chromosomes are compact and more easily visible. Chromosomes that contain ctDNA can be detected using a compound microscope with fluorescent attachments. The location of the ctDNA on the chromosomes is made visible by the fluorescent labeling of the probe. Eight of eleven regions of the chloroplast genome of the B73 line have been specifically amplified and have been observed under the microscope for FISH analysis. This information will contribute to an understanding of the extent and mechanism of transfer of organellar genomes to the nucleus.MU Monsanto Undergraduate Research Fellowshi
Temperature as a Circadian Marker in Older Human Subjects: Relationship to Metabolic Syndrome and Diabetes
Background: Circadian rhythms are characterized by approximate 24-hour oscillations in physiological and behavioral processes. Disruptions in these endogenous rhythms, most commonly associated with shift work and/or lifestyle, are recognized to be detrimental to health. Several studies have demonstrated a high correlation between disrupted circadian rhythms and metabolic disease. The aim of this study was to determine which metabolic parameters correlate with physiological measures of circadian temperature amplitude (TempAmp) and stability (TempStab).
Methods: Wrist skin temperature was measured in 34 subjects (ages 50 to 70, including lean, obese, and diabetic subjects) every 10 minutes for 7 consecutive days. Anthropometric measures and fasting blood draws were conducted to obtain data on metabolic parameters: body mass index, hemoglobin A1C, triglycerides, cholesterol, high-density lipoprotein, and low-density lipoprotein. A history of hypertension and current blood pressure was noted.
Results: Analysis of the data indicated a substantial reduction in TempAmp and TempStab in subjects with metabolic syndrome (three or more risk factors). To determine the impact of individual interdependent metabolic factors on temperature rhythms, stepwise multilinear regression analysis was conducted using metabolic syndrome measurements. Interestingly, only triglyceride level was consistently correlated by the analysis. Triglyceride level was shown to contribute to 33% of the variability in TempAmp and 23% of the variability in TempStab.
Conclusion: Our results demonstrate that elevated triglycerides are associated with diminished TempAmp and TempStab in human subjects, and triglycerides may serve as a primary metabolic predictor of circadian parameters
Analysis of mitochondrial DNA insertions into a nuclear chromosome of the maize B73 line
Abstract only availableMitochondrial DNA (mtDNA) is known to have integrated into the nuclear DNA of plants and animals. The purpose of this project is to investigate the on-going migration of mtDNA into the nuclear DNA of maize plants. Specific objectives are to discover the amount of DNA incorporated, whether it is the whole mitochondrial genome or sections, and to see if it has replicated after migration. The maize inbred line B73 has a particularly large mt DNA insert on chromosome 9. Using the fluorescent in situ hybridization (FISH) method, the arrangement of inserted mitochondrial DNA was examined. The FISH method uses fluorescently labeled mtDNA as probes for hybridization to chromosomes. Regions of the chromosomes that contain mtDNA can then be detected using a compound microscope with fluorescent attachments. Locations that contain more mtDNA are brighter. Three combinations of probes that cover different parts of the mitochondrial genome were employed. In order to analyze the arrangement of the DNA, the chromosomes were prepared from a stage of meiosis called pachynema in which the chromosomes are elongated and have not yet begun to condense. The results have confirmed the presence of all three probes within the large insertion of mtDNA on chromosome 9 of B73. The data suggest that either different parts of the mitochondrial genome are incorporated preferentially or that there is selective replication of portions of the mitochondrial genome after incorporation.MU Monsanto Undergraduate Research Fellowshi
Fetal heart rate responses in chronic hypoxaemia with superimposed repeated hypoxaemia consistent with early labour: a controlled study in fetal sheep
Objective: Deceleration area (DA) and capacity (DC) of the fetal heart rate can help predict risk of intrapartum fetal compromise. However, their predictive value in higher risk pregnancies is unclear. We investigated whether they can predict the onset of hypotension during brief hypoxaemia repeated at a rate consistent with early labour in fetal sheep with pre-existing hypoxaemia.
Design: Prospective, controlled study.
Setting: Laboratory.
Sample: Chronically instrumented, unanaesthetised near-term fetal sheep.
Methods: One-minute complete umbilical cord occlusions (UCOs) were performed every 5 minutes in fetal sheep with baseline paO2 17 mmHg (normoxic, n = 11) for 4 hours or until arterial pressure fell <20 mmHg.
Main outcome measures: DA, DC and arterial pressure.
Results: Normoxic fetuses showed effective cardiovascular adaptation without hypotension and mild acidaemia (lowest arterial pressure 40.7 ± 2.8 mmHg, pH 7.35 ± 0.03). Hypoxaemic fetuses developed hypotension (lowest arterial pressure 20.8 ± 1.9 mmHg, P P = 0.04) and final (P = 0.012) 20 minutes of UCOs. DA was not different between groups.
Conclusion: Chronically hypoxaemic fetuses had early onset of cardiovascular compromise during labour-like brief repeated UCOs. DA was unable to identify developing hypotension in this setting, while DC only showed modest differences between groups. These findings highlight that DA and DC thresholds need to be adjusted for antenatal risk factors, potentially limiting their clinical utility
Plasma Brain-Derived Neurotrophic Factor Levels in Newborn Infants with Neonatal Abstinence Syndrome
Background: Brain-derived neurotrophic factor (BDNF) is a type of growth factor that promotes growth and survival of neurons. Fetal exposure to opiates can lead to postnatal withdrawal syndrome, which is referred as neonatal abstinence syndrome (NAS). Preclinical and clinical studies have shown an association between opiates exposure and alteration in BDNF expression in the brain and serum levels in adult. However, to date, there are no data available on the effects of opiate exposure on BDNF levels in infant who are exposed to opiates in utero and whether BDNF level may correlate with the severity of NAS.
Objective: To compare plasma BDNF levels among NAS and non-NAS infants and to determine the correlation of BDNF levels and the severity of NAS.
Methods: This is a prospective cohort study with no intervention involved. Infants ≥35 weeks of gestation were enrolled. BDNF level was measured using enzyme-linked immunosorbent assay technique from blood samples drawn within 48 h of life. The severity of NAS was determined by the length of hospital stay, number of medications required to treat NAS.
Results: 67 infants were enrolled, 34 NAS and 33 non-NAS. Mean gestational age did not differ between the two groups. Mean birth weight of NAS infants was significantly lower than the non-NAS infants (3,070 ± 523 vs. 3,340 ± 459 g, p = 0.028). Mean BDNF level in NAS group was 252.2 ± 91.6 ng/ml, significantly higher than 211.3 ± 66.3 ng/ml in the non-NAS group (p = 0.04). There were no differences in BDNF levels between NAS infants that required one medication vs. more than one medication (254 ± 91 vs. 218 ± 106 ng/ml, p = 0.47). There was no correlation between the BDNF levels and length of hospital stay (p = 0.68) among NAS infants. Overall, there were no significant correlations between BDNF levels and NAS scores except at around 15 h after admission (correlation 0.35, p = 0.045).
Conclusion: Plasma BDNF level was significantly increased in NAS infants during the first 48 h when compared to non-NAS infants. The correlations between plasma BDNF levels and the severity of NAS warrant further study. These results suggest that BDNF may play a neuromodulatory role during withdrawal after in utero opiate exposure
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