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Metabolic Differences (metabolic + difference)
Selected AbstractsTowards a platform for the metabonomic profiling of different strains of Drosophila melanogaster using liquid chromatography,Fourier transform mass spectrometryFEBS JOURNAL, Issue 22 2009Muhammad A. Kamleh A platform based on hydrophilic interaction chromatography in combination with Fourier transform mass spectrometry was developed in order to carry out metabonomics of Drosophila melanogaster strains. The method was able to detect , 230 metabolites, mainly in the positive ion mode, after checking to eliminate false positives caused by isotope peaks, adducts and fragment ions. Two wild-type strains, Canton S and Oregon R, were studied, plus two mutant strains, Maroon Like and Chocolate. In order to observe the differential expression of metabolites, liquid chromatography-mass spectrometry analyses of the different strains were compared using sieve 1.2 software to extract metabolic differences. The output from sieve was searched against a metabolite database using an Excel-based macro written in-house. Metabolic differences were observed between the wild-type strains, and also between both Chocolate and Maroon Like compared with Oregon R. It was established that a metabonomic approach could produce results leading to the generation of new hypotheses. In addition, the structure of a new class of lipid with a histidine head group, found in all of the strains of flies, but lower in Maroon Like, was elucidated. [source] Metabolic differences between Asian and Caucasian patients on clozapine treatmentHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 4 2007Mythily Subramaniam Abstract Objective To establish if there are ethnic differences in the various metabolic disturbances that are common with clozapine treatment. Method Forty subjects (20 Asians and 20 Caucasians) with a diagnosis of schizophrenia were recruited for the study. Clozapine blood levels as well as fasting blood glucose, lipid levels, and liver function tests were established. Other clinical parameters such as blood pressure and Body Mass Index (BMI) were recorded for each patient. Results The mean clozapine dose was significantly higher in the Caucasian subjects (432.5,±,194.7,mg) as compared to the Asian subjects (175.6,±,106.9,mg) (p,<,0.001) while the mean weight-corrected dose for Asian patients was lower (3.0,±,1.9 and 5.0,±,2.1,mg/kg, respectively, p,=,0.005). There were, however, no ethnic differences in the mean plasma clozapine concentration (415.3,±,185.8,ng/ml in Caucasians and 417.1,±,290.8,ng/ml in Asians). BMI were significantly higher in Caucasians, as were the number of subjects with hypertension; levels of hepatic enzymes were higher in the Asian group. Conclusions Not only are there pharmacokinetic differences between Asian and Caucasian patients receiving clozapine, but there may also be differential emergence of certain metabolic abnormalities like hypertension and weight gain in these two ethnic groups. However, the effects of life style including diet and exercise cannot be excluded. Copyright © 2007 John Wiley & Sons, Ltd. [source] Metabolic differences between primary and recurrent human brain tumors: a 1H NMR spectroscopic investigationNMR IN BIOMEDICINE, Issue 6 2005Fritz-Georg Lehnhardt Abstract High-resolution proton magnetic resonance spectroscopy was performed on tissue specimens from 33 patients with astrocytic tumors (22 astrocytomas, 11 glioblastomas) and 13 patients with meningiomas. For all patients, samples of primary tumors and their first recurrences were examined. Increased anaplasia, with respect to malignant transformation, resulting in a higher malignancy grade, was present in 11 recurrences of 22 astrocytoma patients. Spectroscopic features of tumor types, as determined on samples of the primary occurrences, were in good agreement with previous studies. Compared with the respective primary astrocytomas, characteristic features of glioblastomas were significantly increased concentrations of alanine (Ala) (p,=,0.005), increased metabolite ratios of glycine (Gly)/total creatine (tCr) (p,=,0.0001) and glutamate (Glu)/glutamine (Gln) (p,=,0.004). Meningiomas showed increased Ala (p,=,0.02) and metabolite ratios [Gly, total choline (tCho), Ala] over tCr (p,=,0.001) relative to astrocytomas, and N -acetylaspartate and myo-inositol were absent. Metabolic changes of an evolving tumor were observed in recurrent astrocytomas: owing to their consecutive assessments, more indicators of malignant degeneration were detected in astrocytoma recurrences (e.g. Gly, p,=,0.029; tCho, p,=,0.034; Glu, p,=,0.015; tCho/tCr, p,=,0.001) in contrast to the comparison of primary astrocytomas with primary glioblastomas. The present investigation demonstrated a correlation of the tCho-signal with tumor progression. Significantly elevated concentrations of Ala (p,=,0.037) and Glu (p,=,0.003) and metabolite ratio tCho/tCr (p,=,0.005) were even found in recurrent low-grade astrocytomas with unchanged histopathological grading (n,=,11). This may be related to an early stage of malignant transformation, not yet detectable morphologically, and emphasizes the high sensitivity of 1H NMR spectroscopy in elucidating characteristics of brain tumor metabolism. Copyright © 2005 John Wiley & Sons, Ltd. [source] Metabolic differences between male and female adolescents with non-alcoholic fatty liver disease, as detected by ultrasoundACTA PAEDIATRICA, Issue 8 2010MTB Fernandes Abstract Background:, Age, developmental stage and gender are risk factors for paediatric non-alcoholic fatty liver disease (NAFLD). Aims:, The aim of this study was to identify differences in clinical or laboratory variables between sexes in adolescents with NAFLD. Methodology:, Ninety obese adolescents including 36 males and 54 females were evaluated. Inclusion criteria for this study were a Body Mass Index above the 95th percentile, as set forth by the National Center for Health Statistics, and an age of 10,19 years. A clinical and laboratory evaluation was conducted for all adolescents. Results:, The variables that were found to be predictive of NAFLD in adolescence were visceral fat, Aminotransferase, Gamma-Glutamyl Transferase, triglyderides, cholesterol and LDL-cholesterol. We also observed that cholesterol and LDL-cholesterol variables were influenced by gender, i.e. there was a significant statistical difference in the values of these variables between male and female adolescents. With regard to cholesterol serum concentrations, the risk was 6.99 times greater for females, compared with 1.2 times for males; and for LDL-cholesterol serum concentrations the risk was 8.15 times greater for females, compared with and 1.26 times for males. Conclusion:, Female adolescents with NAFLD showed a significantly different metabolic behaviour than males. [source] A serum metabolomic investigation on hepatocellular carcinoma patients by chemical derivatization followed by gas chromatography/mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 19 2008Ruyi Xue The purpose of this study was to investigate the serum metabolic difference between hepatocellular carcinoma (HCC, n,=,20) male patients and normal male subjects (n,=,20). Serum metabolome was detected through chemical derivatization followed by gas chromatography/mass spectrometry (GC/MS). The acquired GC/MS data was analyzed by stepwise discriminant analysis (SDA) and support vector machine (SVM). The metabolites including butanoic acid, ethanimidic acid, glycerol, L-isoleucine, L-valine, aminomalonic acid, D-erythrose, hexadecanoic acid, octadecanoic acid, and 9,12-octadecadienoic acid in combination with each other gave the strongest segregation between the two groups. By applying these variables, our method provided a diagnostic model that could well discriminate between HCC patients and normal subjects. More importantly, the error count estimate for each group was 0%. The total classifying accuracy of the discriminant function tested by SVM 20-fold cross validation was 75%. This technique is different from traditional ones and appears to be a useful tool in the area of HCC diagnosis. Copyright © 2008 John Wiley & Sons, Ltd. [source] Approach to procedures in neonatesDERMATOLOGIC THERAPY, Issue 2 2005Valerie B. Lyon ABSTRACT:, Physical constraints and metabolic differences in neonates require that special attention is given to performing procedures in this patient group. Neonates have a thinner dermis and a greater surface-to-weight ratio, allowing for easier invasion through the skin barrier. The enzymes for metabolism of agents and defense against organisms inside the body are not fully developed in infants. Very premature neonates also have less circulating albumin, making the effective concentration of circulating agent even greater. The infant is prone to unanticipated movement during procedures, such as rolling on the procedure table. The neonatal period is the most common time period for malformations to become manifest on the skin, and invasion of some of these lesions can produce morbidity. These and other factors affect the choice of the type of procedure used, the timing for intervention, and the approach to intervention in this age group. This article reviews the important considerations for approaching procedures and offers suggestions for safe and effective methods of reliably producing the intended outcome. [source] Towards a platform for the metabonomic profiling of different strains of Drosophila melanogaster using liquid chromatography,Fourier transform mass spectrometryFEBS JOURNAL, Issue 22 2009Muhammad A. Kamleh A platform based on hydrophilic interaction chromatography in combination with Fourier transform mass spectrometry was developed in order to carry out metabonomics of Drosophila melanogaster strains. The method was able to detect , 230 metabolites, mainly in the positive ion mode, after checking to eliminate false positives caused by isotope peaks, adducts and fragment ions. Two wild-type strains, Canton S and Oregon R, were studied, plus two mutant strains, Maroon Like and Chocolate. In order to observe the differential expression of metabolites, liquid chromatography-mass spectrometry analyses of the different strains were compared using sieve 1.2 software to extract metabolic differences. The output from sieve was searched against a metabolite database using an Excel-based macro written in-house. Metabolic differences were observed between the wild-type strains, and also between both Chocolate and Maroon Like compared with Oregon R. It was established that a metabonomic approach could produce results leading to the generation of new hypotheses. In addition, the structure of a new class of lipid with a histidine head group, found in all of the strains of flies, but lower in Maroon Like, was elucidated. [source] Essential pathogenic and metabolic differences in steatosis induced by choline or methione-choline deficient diets in a rat modelJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2007Reeta Veteläinen Abstract Background and Aim:, Choline deficient (CD) and methione-choline deficient (MCD) diets are rodent models for steatosis, with potentially dissimilar biochemical backgrounds. The aim of this study was to assess the metabolic and pathological derangements in rats fed CD and MCD diets. Methods:, Male Wistar rats received CD or MCD diet up to 7 weeks. Nutritional status, liver histopathology, Kupffer cell-mediated inflammation and injury, oxidative stress via thiobarbituric reactive species (TBARS), hepatic and plasma glutathione (GSH) and insulin homeostasis were assessed. Results:, In CD-fed rats, mainly microvesicular steatosis developed with occasional inflammatory cells. In MCD-fed rats, macrovesicular steatosis progressed to steatohepatitis (collagen deposition, activated stellate cells). Hepatic TBARS was increased and GSH decreased in the MCD-fed rats compared to no changes in the CD-fed rats. The CD-fed rats developed obesity, dyslipidemia and insulin resistance, in contrast to undetectable plasma lipids, unaffected insulin homeostasis and loss of body weight in the MCD-fed rats. Conclusions:, The CD diet induced uncomplicated steatosis as compared to progressive inflammation and fibrinogenesis in the MCD diet. CD and MCD diets represent two pathogenically different models of steatosis. Although equivalence for the outcome of both diets can be found in clinical steatosis, the results of models using these diets should be compared with caution. [source] Comparative oxidative metabolic profiles of clomipramine in cats, rats and dogs: preliminary results from an in vitro studyJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2007C. LAINESSE The objectives of this in vitro study were to describe cytochrome-dependent metabolism of clomipramine in canine and feline microsomes, compare metabolic profiles between cats, rats and dogs, and investigate a potential gender-related difference in metabolic activity between male and female cats. Pooled liver microsomes were incubated with clomipramine, where species and gender-specific reactions were initiated by the addition of a nicotinamide adenine dinucleotide phosphate regenerating system and quenched with methanol at 0, 5, 15, 30, 45 and 60 min, and 0, 30, 60, 90, 120, 180, 240 and 360 min respectively. Liquid chromatography tandem mass spectrometry was used to measure clomipramine and its metabolites. Preliminary results showed that cat microsomes biotransformed clomipramine slower and less efficiently than rat and dog microsomes. Moreover, gender differences in metabolic profiles suggested that male cat microsomes may be less efficient demethylators and hydroxylators than female cat microsomes. As gender metabolic differences may carry clinical significance for this antidepressant, further studies are warranted. [source] Reduced N -acetylaspartate is consistent with axonal dysfunction in cerebral small vessel diseaseNMR IN BIOMEDICINE, Issue 3 2009Arani Nitkunan Abstract Background: Cerebral small vessel disease (SVD) is an important cause of cognitive impairment, but the pathophysiological mechanisms remain unclear. We used 1H MRS to investigate brain metabolic differences between patients with SVD and controls and correlated this with cognition. Methods: 35 patients with SVD (lacunar stroke and radiological evidence of confluent leukoaraiosis) and 35 controls underwent multi-voxel spectroscopic imaging of white matter to obtain absolute metabolite concentrations of N -acetylaspartate (NAA), total creatines, total cholines, myo -inositol, and lactate. A range of cognitive tests was performed on patients with SVD, and composite scores were calculated. Results: Scans of sufficient quality for data analysis were available in 29 cases and 35 controls. NAA was significantly reduced in patients compared with controls (lower by 7.27%, P,=,0.004). However, when lesion load within each individual voxel (mean 22% in SVD vs 5% in controls, P,<,0.001) was added as a covariate, these differences were no longer significant, suggesting that the metabolite differences arose primarily from differences in lesioned tissue. In patients with SVD, there was no correlation between cognitive scores and any brain metabolite. No lactate, an indicator of anaerobic metabolism, was detected. Conclusions: The most consistent change in SVD is a reduction in NAA, a marker of neuronal integrity. The lack of correlation with cognition does not support the use of MRS as a surrogate disease marker. Copyright © 2008 John Wiley & Sons, Ltd. [source] Modelling of reserve carbohydrate dynamics, regrowth and nodulation in a N2 -fixing tree managed by periodic pruningsPLANT CELL & ENVIRONMENT, Issue 10 2000F. Berninger ABSTRACT We used a modified transport resistance approach to model legume tree growth, nodulation and dynamics of reserve carbohydrates after pruning. The model distributes growth between roots and shoots applying the transport resistance approach. Within shoots, growth is divided into leaves, branches and stems applying the pipe model theory. The model also accounts for the metabolic differences of principal N sources, nitrate, ammonium and atmospheric dinitrogen, in a mechanistic way. We compared the simulation results with measured biomass dynamics of Gliricidia sepium (Jacq.) Walp. (Papilionaceae: Robinieae) under humid and subhumid tropical conditions. Comparison showed that the biomass production predicted by the model is close to measured values. Total N2 fixation is also similar to measured values. Qualitatively the model increases the proportion of N2 fixation if roots acquire less mineral N. In the present study, the general form of the model is discussed and compared with similar models. The results encourage the use of this approach for studying biomass dynamics of legume trees under the scheme of periodic prunings. Also, it shows that process-based models have potential in the simulation of trees disturbed by prunings, herbivory or similar factors. [source] Natural abundance of 15N and 13C in fish tissues and the use of stable isotopes as dietary protein tracers in rainbow trout and gilthead sea breamAQUACULTURE NUTRITION, Issue 1 2009M. BELTRÁN Abstract For developing efficient diets, two sets of experiments examined whether the use and allocation of dietary protein can be traced by labelling with stable isotopes (15N and 13C) in two culture fish (Oncorhynchus mykiss and Sparus aurata). In the first experiment, natural abundance and tissue distribution of these isotopes were determined, by measuring the ,13C and ,15N values by isotopic ratio mass spectrometry, in fingerlings (14,17 g) adapted to diets differing in the percentage of fish meal replacement by plant protein sources. For both species, ,15N and ,13C were greater in tissues with higher protein and lower lipid content. Delta 15N of diets and tissues decreased as replacement increased, suggesting ,15N can be used as a marker for dietary protein origin. The 15N fractionation (,15N fish , ,15N diet) differed between groups, and could thus be used to indicate protein catabolism. In the second experiment, fish (75,90 g) of each species ingested a diet enriched with 15N-protein (10 g kg,1 diet) and 13C-protein (30 g kg,1 diet). These proportions were suitable for determining that the delta values of tissue components were high enough above natural levels to allow protein allocation to be traced at 11 and 24 h after feeding, and revealed clear metabolic differences between species. [source] Feed development for fed-batch CHO production process by semisteady state analysisBIOTECHNOLOGY PROGRESS, Issue 3 2010Sarwat F. Khattak Abstract Semisteady state cultures are useful for studying cell physiology and facilitating media development. Two semisteady states with a viable cell density of 5.5 million cells/mL were obtained in CHO cell cultures and compared with a fed-batch mode control. In the first semisteady state, the culture was maintained at 5 mM glucose and 0.5 mM glutamine. The second condition had threefold higher concentrations of both nutrients, which led to a 10% increase in lactate production, a 78% increase in ammonia production, and a 30% reduction in cell growth rate. The differences between the two semisteady states indicate that maintaining relatively low levels of glucose and glutamine can reduce the production of lactate and ammonia. Specific amino acid production and consumption indicated further metabolic differences between the two semisteady states and fed-batch mode. The results from this experiment shed light in the feeding strategy for a fed-batch process and feed medium enhancement. The fed-batch process utilizes a feeding strategy whereby the feed added was based on glucose levels in the bioreactor. To evaluate if a fixed feed strategy would improve robustness and process consistency, two alternative feeding strategies were implemented. A constant volume feed of 30% or 40% of the initial culture volume fed over the course of cell culture was evaluated. The results indicate that a constant volumetric-based feed can be more beneficial than a glucose-based feeding strategy. This study demonstrated the applicability of analyzing CHO cultures in semisteady state for feed enhancement and continuous process improvement. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Magnetic resonance spectroscopy in anxiety disordersACTA NEUROPSYCHIATRICA, Issue 2 2008Clarissa Trzesniak Objective:, Magnetic resonance spectroscopy (MRS) is a non-invasive in vivo method used to quantify metabolites that are relevant to a wide range of brain processes. This paper briefly describes neuroimaging using MRS and provides a systematic review of its application to anxiety disorders. Method:, A literature review was performed in the PubMed, Lilacs and Scielo databases using the keywords spectroscopy and anxiety disorder. References of selected articles were also hand-searched for additional citations. Results:, Recent studies have shown that there are significant metabolic differences between patients with anxiety disorders and healthy controls in various regions of the brain. Changes were mainly found in N -acetylaspartate, which is associated with neuronal viability, but some of them were also seen in creatine, a substance that is thought to be relatively constant among individuals with different pathological conditions. Conclusions:, MRS is a sophisticated neuroimaging technique that has provided useful insights into the biochemical and neurobiological basis of many anxiety disorders. Nevertheless, its utilization in some anxiety disorders is still modest, particularly social phobia and generalised anxiety. Although it is an extremely useful advance in neuroimaging, further research in other brain areas and patient populations is highly advisable. [source] | ||||||||||||||||