Skip header and navigation

Refine By

112 records – page 1 of 12.

1H-MRS Measured Ectopic Fat in Liver and Muscle in Danish Lean and Obese Children and Adolescents.

https://arctichealth.org/en/permalink/ahliterature273208
Source
PLoS One. 2015;10(8):e0135018
Publication Type
Article
Date
2015
Author
Cilius Esmann Fonvig
Elizaveta Chabanova
Ehm Astrid Andersson
Johanne Dam Ohrt
Oluf Pedersen
Torben Hansen
Henrik S Thomsen
Jens-Christian Holm
Source
PLoS One. 2015;10(8):e0135018
Date
2015
Language
English
Publication Type
Article
Keywords
Adolescent
Anthropometry
Blood Glucose - analysis
Blood pressure
Body mass index
Body Weight
Cardiovascular Diseases - physiopathology
Child
Cross-Sectional Studies
Denmark
Dyslipidemias - blood
Fatty Liver - pathology
Female
Humans
Insulin - blood
Insulin Resistance
Intra-Abdominal Fat - pathology
Linear Models
Lipids - blood
Liver - metabolism - pathology
Male
Muscles - pathology
Overweight
Pediatric Obesity - blood - pathology
Proton Magnetic Resonance Spectroscopy
Puberty
Sex Factors
Subcutaneous Fat - pathology
Abstract
This cross sectional study aims to investigate the associations between ectopic lipid accumulation in liver and skeletal muscle and biochemical measures, estimates of insulin resistance, anthropometry, and blood pressure in lean and overweight/obese children.
Fasting plasma glucose, serum lipids, serum insulin, and expressions of insulin resistance, anthropometry, blood pressure, and magnetic resonance spectroscopy of liver and muscle fat were obtained in 327 Danish children and adolescents aged 8-18 years.
In 287 overweight/obese children, the prevalences of hepatic and muscular steatosis were 31% and 68%, respectively, whereas the prevalences in 40 lean children were 3% and 10%, respectively. A multiple regression analysis adjusted for age, sex, body mass index z-score (BMI SDS), and pubertal development showed that the OR of exhibiting dyslipidemia was 4.2 (95%CI: [1.8; 10.2], p = 0.0009) when hepatic steatosis was present. Comparing the simultaneous presence of hepatic and muscular steatosis with no presence of steatosis, the OR of exhibiting dyslipidemia was 5.8 (95%CI: [2.0; 18.6], p = 0.002). No significant associations between muscle fat and dyslipidemia, impaired fasting glucose, or blood pressure were observed. Liver and muscle fat, adjusted for age, sex, BMI SDS, and pubertal development, associated to BMI SDS and glycosylated hemoglobin, while only liver fat associated to visceral and subcutaneous adipose tissue and intramyocellular lipid associated inversely to high density lipoprotein cholesterol.
Hepatic steatosis is associated with dyslipidemia and liver and muscle fat depositions are linked to obesity-related metabolic dysfunctions, especially glycosylated hemoglobin, in children and adolescents, which suggest an increased cardiovascular disease risk.
Notes
Cites: Child Obes. 2012 Dec;8(6):533-4123181919
Cites: Int J Pediatr Obes. 2011 Aug;6(3-4):188-9621529264
Cites: Int J Obes (Lond). 2014 Jan;38(1):40-523828099
Cites: Pediatr Diabetes. 2014 May;15(3):151-6124754463
Cites: Semin Liver Dis. 2001;21(1):3-1611296695
Cites: Pediatr Clin North Am. 2011 Dec;58(6):1375-92, x22093857
Cites: Obesity (Silver Spring). 2012 Feb;20(2):371-521869763
Cites: AJR Am J Roentgenol. 2012 Jul;199(1):2-722733887
Cites: J Clin Endocrinol Metab. 2012 Jul;97(7):E1099-10522508709
Cites: Nutr Metab Cardiovasc Dis. 2009 Feb;19(2):146-5219171470
Cites: Pediatr Diabetes. 2014 Sep;15 Suppl 20:4-1725182305
Cites: Int J Obes Relat Metab Disord. 2001 Feb;25(2):177-8411410817
Cites: J Clin Endocrinol Metab. 2001 Dec;86(12):5755-6111739435
Cites: Diabetes. 2002 Apr;51(4):1022-711916921
Cites: Circulation. 2003 Mar 25;107(11):1562-612654618
Cites: Lancet. 2003 Sep 20;362(9388):951-714511928
Cites: Pediatrics. 2004 Aug;114(2 Suppl 4th Report):555-7615286277
Cites: Int J Obes Relat Metab Disord. 2004 Oct;28(10):1257-6315278103
Cites: Nutr Rev. 1981 Feb;39(2):43-557010232
Cites: Stat Med. 1992 Jul;11(10):1305-191518992
Cites: Am J Clin Nutr. 1993 Oct;58(4):463-78379501
Cites: Diabetes. 1997 Jun;46(6):983-89166669
Cites: Diabetologia. 1999 Jan;42(1):113-610027589
Cites: Diabetes. 1999 Oct;48(10):2039-4410512371
Cites: Obesity (Silver Spring). 2006 Mar;14(3):357-6716648604
Cites: Pediatrics. 2006 Oct;118(4):1388-9317015527
Cites: Diabetes Care. 2007 Jan;30(1):89-9417192339
Cites: Eur J Clin Nutr. 2007 Jul;61(7):877-8317151586
Cites: Circulation. 2008 Jul 15;118(3):277-8318591439
Cites: Diabetes Care. 2009 Feb;32(2):342-718957533
Cites: J Clin Endocrinol Metab. 2009 Sep;94(9):3440-719531593
Cites: Am J Epidemiol. 2010 Jun 1;171(11):1195-20220457571
Cites: Eur J Endocrinol. 2010 Sep;163(3):413-920584996
Cites: J Clin Endocrinol Metab. 2010 Dec;95(12):5189-9820829185
Cites: J Clin Res Pediatr Endocrinol. 2010;2(3):100-621274322
Cites: Diabetologia. 2011 Apr;54(4):869-7521181394
Cites: Abdom Imaging. 2013 Apr;38(2):315-922736224
PubMed ID
26252778 View in PubMed
Less detail

1H MRS studies in the Finnish boron neutron capture therapy project: detection of 10B-carrier, L-p-boronophenylalanine-fructose.

https://arctichealth.org/en/permalink/ahliterature172386
Source
Eur J Radiol. 2005 Nov;56(2):154-9
Publication Type
Article
Date
Nov-2005
Author
M. Timonen
L. Kankaanranta
N. Lundbom
J. Collan
A. Kangasmäki
M. Kortesniemi
A-M Häkkinen
A. Lönngren
S. Karjalainen
M. Rasilainen
J. Leinonen
T. Huitti
J. Jääskeläinen
M. Kouri
S. Savolainen
S. Heikkinen
Author Affiliation
Department of Physical Sciences, University of Helsinki, POB 64, FIN-00014, Helsinki, Finland.
Source
Eur J Radiol. 2005 Nov;56(2):154-9
Date
Nov-2005
Language
English
Publication Type
Article
Keywords
Adult
Aged
Boron - therapeutic use
Boron Compounds - analysis - blood
Boron Neutron Capture Therapy
Brain Neoplasms - pathology - radiotherapy
Carcinoma - pathology - radiotherapy
Female
Finland
Fructose - analogs & derivatives - analysis - blood
Glioblastoma - pathology - radiotherapy
Humans
Hydrogen
Isotopes - therapeutic use
Magnetic Resonance Spectroscopy - methods
Male
Neoplasm Recurrence, Local - pathology - radiotherapy
Paranasal Sinus Neoplasms - pathology - radiotherapy
Phantoms, Imaging
Plasma
Radiopharmaceuticals - therapeutic use
Abstract
This article summarizes the current status of 1H MRS in detecting and quantifying a boron neutron capture therapy (BNCT) boron carrier, L-p-boronophenylalanine-fructose (BPA-F) in vivo in the Finnish BNCT project. The applicability of 1H MRS to detect BPA-F is evaluated and discussed in a typical situation with a blood containing resection cavity within the gross tumour volume (GTV). 1H MRS is not an ideal method to study BPA concentration in GTV with blood in recent resection cavity. For an optimal identification of BPA signals in the in vivo 1H MR spectrum, both pre- and post-infusion 1H MRS should be performed. The post-infusion spectroscopy studies should be scheduled either prior to or, less optimally, immediately after the BNCT. The pre-BNCT MRS is necessary in order to utilise the MRS results in the actual dose planning.
PubMed ID
16233888 View in PubMed
Less detail

1H-NMR metabolomic biomarkers of poor outcome after hemorrhagic shock are absent in hibernators.

https://arctichealth.org/en/permalink/ahliterature267428
Source
PLoS One. 2014;9(9):e107493
Publication Type
Article
Date
2014
Author
Lori K Bogren
Carl J Murphy
Erin L Johnston
Neeraj Sinha
Natalie J Serkova
Kelly L Drew
Source
PLoS One. 2014;9(9):e107493
Date
2014
Language
English
Publication Type
Article
Keywords
Animals
Biological Markers - blood
Hibernation
Lipids - blood
Magnetic Resonance Spectroscopy
Male
Metabolome
Rats, Sprague-Dawley
Reperfusion Injury - blood - prevention & control
Sciuridae
Shock, Hemorrhagic - blood - therapy
Treatment Outcome
Abstract
Hemorrhagic shock (HS) following trauma is a leading cause of death among persons under the age of 40. During HS the body undergoes systemic warm ischemia followed by reperfusion during medical intervention. Ischemia/reperfusion (I/R) results in a disruption of cellular metabolic processes that ultimately lead to tissue and organ dysfunction or failure. Resistance to I/R injury is a characteristic of hibernating mammals. The present study sought to identify circulating metabolites in the rat as biomarkers for metabolic alterations associated with poor outcome after HS. Arctic ground squirrels (AGS), a hibernating species that resists I/R injury independent of decreased body temperature (warm I/R), was used as a negative control.
Male Sprague-Dawley rats and AGS were subject to HS by withdrawing blood to a mean arterial pressure (MAP) of 35 mmHg and maintaining the low MAP for 20 min before reperfusing with Ringers. The animals' temperature was maintained at 37 ? 0.5 ?C for the duration of the experiment. Plasma samples were taken immediately before hemorrhage and three hours after reperfusion. Hydrophilic and lipid metabolites from plasma were then analyzed via 1H-NMR from unprocessed plasma and lipid extracts, respectively. Rats, susceptible to I/R injury, had a qualitative shift in their hydrophilic metabolic fingerprint including differential activation of glucose and anaerobic metabolism and had alterations in several metabolites during I/R indicative of metabolic adjustments and organ damage. In contrast, I/R injury resistant AGS, regardless of season or body temperature, maintained a stable metabolic homeostasis revealed by a qualitative 1H-NMR metabolic profile with few changes in quantified metabolites during HS-induced global I/R.
An increase in circulating metabolites indicative of anaerobic metabolism and activation of glycolytic pathways is associated with poor prognosis after HS in rats. These same biomarkers are absent in AGS after HS with warm I/R.
Notes
Cites: Am J Physiol Regul Integr Comp Physiol. 2010 Feb;298(2):R329-4019923364
Cites: Gerontology. 2010;56(2):220-3019602865
Cites: Am J Physiol Regul Integr Comp Physiol. 2011 Nov;301(5):R1440-5221865542
Cites: Transplantation. 2011 Dec 15;92(11):1215-2122082817
Cites: Am J Respir Crit Care Med. 2011 Sep 15;184(6):647-5521680948
Cites: Pharmacol Ther. 2012 Feb;133(2):230-5522138603
Cites: Bioanalysis. 2012 Feb;4(3):321-4122303835
Cites: Resuscitation. 2012 Feb;83(2):253-821864484
Cites: Comp Biochem Physiol B Biochem Mol Biol. 2012 May;162(1-3):1-922326449
Cites: Nucleic Acids Res. 2012 Jul;40(Web Server issue):W127-3322553367
Cites: Physiol Genomics. 2012 Jul 15;44(14):717-2722643061
Cites: Resuscitation. 2012 Sep;83(9):1166-7222353638
Cites: Exp Biol Med (Maywood). 2013 May;238(5):539-4823856905
Cites: J Surg Res. 2014 Jan;186(1):338-4524124975
Cites: PLoS One. 2014;9(4):e9422524728042
Cites: Jpn J Pharmacol. 2001 Oct;87(2):143-5011700013
Cites: Am J Surg. 2001 Nov;182(5):481-511754855
Cites: J Comp Physiol B. 2010 Apr;180(4):599-61719967378
Cites: J Trauma. 2010 Jul;69(1):31-4020622576
Cites: J Surg Res. 2010 Nov;164(1):e131-920855081
Cites: Shock. 2010 Dec;34(6):565-7220386494
Cites: Comp Biochem Physiol Part D Genomics Proteomics. 2010 Dec;5(4):265-7320728417
Cites: Am J Physiol Lung Cell Mol Physiol. 2011 Jan;300(1):L4-L1120889676
Cites: J Exp Biol. 2011 Apr 15;214(Pt 8):1300-621430207
Cites: Physiol Genomics. 2011 Jul 14;43(13):799-80721540299
Cites: PLoS One. 2011;6(10):e2702122046435
Cites: Jpn J Pharmacol. 2002 May;89(1):36-4312083741
Cites: Horm Behav. 2003 Feb;43(2):318-2612694642
Cites: J Emerg Med. 2003 May;24(4):413-2212745044
Cites: Surgery. 2003 Aug;134(2):267-7412947328
Cites: Biol Reprod. 1988 Apr;38(3):616-223378074
Cites: J Comp Physiol B. 1988;158(1):25-373385059
Cites: Science. 1989 Jun 30;244(4912):1593-52740905
Cites: J Lipid Res. 1993 Jun;34(6):1009-198354948
Cites: J Cereb Blood Flow Metab. 1994 Mar;14(2):193-2058113316
Cites: Anal Chem. 1995 Mar 1;67(5):793-8117762816
Cites: J Cereb Blood Flow Metab. 1998 Feb;18(2):168-759469159
Cites: Kidney Int. 2005 Mar;67(3):1142-5115698456
Cites: Physiol Rev. 2003 Oct;83(4):1153-8114506303
Cites: Annu Rev Physiol. 2004;66:239-7414977403
Cites: Am J Physiol Gastrointest Liver Physiol. 2005 Mar;288(3):G473-8015701622
Cites: Chem Res Toxicol. 2005 Apr;18(4):639-5415833024
Cites: Annu Rev Nutr. 2005;25:469-9716011475
Cites: Anesth Analg. 2005 Dec;101(6):1577-8316301222
Cites: J Hepatol. 2006 May;44(5):956-6216223541
Cites: Stroke. 2006 May;37(5):1261-516574920
Cites: Surgery. 2006 Sep;140(3):404-1216934602
Cites: Am J Physiol Gastrointest Liver Physiol. 2006 Nov;291(5):G895-90116751173
Cites: J Surg Res. 2007 Jan;137(1):96-10217064732
Cites: JPEN J Parenter Enteral Nutr. 2007 Mar-Apr;31(2):94-10017308249
Cites: Bioessays. 2007 May;29(5):431-4017450592
Cites: Acta Cardiol. 2007 Aug;62(4):381-917824299
Cites: Physiol Genomics. 2007 Sep 19;31(1):15-2417536023
Cites: J Cereb Blood Flow Metab. 2008 Jul;28(7):1307-1918398417
Cites: J Neural Transm (Vienna). 2008 Jul;115(7):1011-718478178
Cites: Am J Physiol Regul Integr Comp Physiol. 2008 Jul;295(1):R316-2818434441
Cites: Allergol Int. 2008 Sep;57(3):211-718566550
Cites: Crit Care. 2008;12(4):21818638356
Cites: Shock. 2009 Jan;31(1):40-918497709
Cites: Am J Physiol Regul Integr Comp Physiol. 2009 Feb;296(2):R383-9319052316
Cites: Conf Proc IEEE Eng Med Biol Soc. 2008;2008:4891-419163813
Cites: Brain Res Rev. 2009 Mar;59(2):293-31518845187
Cites: Nucleic Acids Res. 2009 Jul;37(Web Server issue):W652-6019429898
Cites: J Neurochem. 2009 Aug;110(4):1170-919493168
Cites: Exp Biol Med (Maywood). 2009 Sep;234(9):1011-919546346
Cites: Mol Biosyst. 2010 Jan;6(1):215-2420024083
PubMed ID
25211248 View in PubMed
Less detail

1H NMR studies on human plasma lipids from newborn infants, healthy adults, and adults with tumors.

https://arctichealth.org/en/permalink/ahliterature25704
Source
Magn Reson Med. 1989 Jan;9(1):35-8
Publication Type
Article
Date
Jan-1989
Author
S. Eskelinen
Y. Hiltunen
J. Jokisaari
S. Virtanen
K. Kiviniitty
Author Affiliation
Department of Biomedical Physics, University of Oulu, Finland.
Source
Magn Reson Med. 1989 Jan;9(1):35-8
Date
Jan-1989
Language
English
Publication Type
Article
Keywords
Adult
Female
Humans
Hydrogen
Infant, Newborn - blood
Lactates - blood
Lipoproteins - blood
Magnetic Resonance Spectroscopy - diagnostic use
Male
Methane - blood
Neoplasms - blood
Protons
Abstract
The 1H NMR spectra of the lipid region of human plasma from healthy adults, neonates, and patients with malignant and nonmalignant tumors have been recorded on a JNM-GX400 FT spectrometer operating at 399.6 MHz for protons. The chemical shifts of methylene and methyl groups of plasma lipids were measured with respect to the higher field component of the methyl proton resonance of the lactate molecule. The results show that there are changes in the chemical shifts of the methylene proton resonances among the plasma from healthy adults, adults with tumors, and neonates. The shifts observed in the case of cancer patients and neonates are in the direction opposite to the shift measured from the plasma of healthy adults. Thus, the observed changes cannot be explained by the activity in the cell proliferation of tissues which is high in the cases of both healthy neonates and patients with malignant tumors, but they most probably reflect the different lipoprotein compositions of neonates, healthy adults, and adults with tumors.
PubMed ID
2540395 View in PubMed
Less detail

1 H NMR study and multivariate data analysis of reindeer skin tanning methods.

https://arctichealth.org/en/permalink/ahliterature291047
Source
Magn Reson Chem. 2017 Apr; 55(4):312-317
Publication Type
Journal Article
Date
Apr-2017
Author
Lizheng Zhu
Andrew J Ilott
Eleonora Del Federico
Cindie Kehlet
Torunn Klokkernes
Alexej Jerschow
Author Affiliation
Department of Chemistry, New York University, New York, NY, USA.
Source
Magn Reson Chem. 2017 Apr; 55(4):312-317
Date
Apr-2017
Language
English
Publication Type
Journal Article
Keywords
Animals
Humans
Magnetic Resonance Spectroscopy
Multivariate Analysis
Plant Extracts - chemistry
Reindeer
Seasons
Skin - chemistry
Tanning - methods
Tannins - chemistry
Vegetables - chemistry
Abstract
Reindeer skin clothing has been an essential component in the lives of indigenous people of the arctic and sub-arctic regions, keeping them warm during harsh winters. However, the skin processing technology, which often conveys the history and tradition of the indigenous group, has not been well documented. In this study, NMR spectra and relaxation behaviors of reindeer skin samples treated with a variety of vegetable tannin extracts, oils and fatty substances are studied and compared. With the assistance of principal component analysis (PCA), one can recognize patterns and identify groupings of differently treated samples. These methods could be important aids in efforts to conserve museum leather artifacts with unknown treatment methods and in the analysis of reindeer skin tanning processes. Copyright © 2016 John Wiley & Sons, Ltd.
PubMed ID
27654838 View in PubMed
Less detail

31P-NMR study of skeletal muscle metabolism in patients with chronic respiratory impairment.

https://arctichealth.org/en/permalink/ahliterature5321
Source
Am Rev Respir Dis. 1992 Oct;146(4):1019-24
Publication Type
Article
Date
Oct-1992
Author
T. Kutsuzawa
S. Shioya
D. Kurita
M. Haida
Y. Ohta
H. Yamabayashi
Author Affiliation
Department of Respiratory Medicine, Tokai University School of Medicine, Isehara, Japan.
Source
Am Rev Respir Dis. 1992 Oct;146(4):1019-24
Date
Oct-1992
Language
English
Publication Type
Article
Keywords
Aged
Anaerobic Threshold - physiology
Energy Metabolism - physiology
Exercise - physiology
Forearm
Glycolysis - physiology
Humans
Hydrogen-Ion Concentration
Lung Diseases, Obstructive - metabolism
Magnetic Resonance Spectroscopy - diagnostic use
Male
Middle Aged
Muscles - metabolism
Phosphates - metabolism
Phosphocreatine - metabolism
Research Support, Non-U.S. Gov't
Abstract
To evaluate the energy metabolism of peripheral skeletal muscle during exercise in patients with chronic respiratory impairment, the 31P-nuclear magnetic resonance (NMR) spectra of forearm muscle were investigated in nine patients and nine age-matched control subjects. We calculated the phosphocreatine (PCr) to PCr + inorganic phosphate (PI) ratio, the time constant of PCr recovery and the intracellular pH. The exercise consisted of repetitive hand grips against a 2-kg load every 3 s for 6 min (0.33 W). The patients showed a marked decrease in the PCr/(PCr + PI) ratio and pH in the muscle during exercise in contrast to the control subjects whose PCr/(PCr + PI) showed a minor decrease without any change in pH. The relationship between PCr utilization and pH demonstrated that anaerobic glycolysis switched on earlier in patients with chronic respiratory impairment. A split PI peak was observed in five of nine patients during exercise. The PCr/(PCr + PI) ratio during the last minute of exercise correlated significantly with the vital capacity (% predicted), with the FEV1/FVC, with the body weight, with the maximum strength of hand grip, and with the muscle mass. The results indicate impaired oxidative phosphorylation and the early activation of anaerobic glycolysis in the muscles of patients with chronic respiratory impairment. Several factors related to chronic respiratory impairment, such as disuse, malnutrition and dysoxia, would contribute to the metabolic changes observed in the muscles examined.
PubMed ID
1416390 View in PubMed
Less detail

Abnormality of energy metabolism in the skeletal muscle of patients with liver cirrhosis and changes under administration of glucose and branched-chain amino acids.

https://arctichealth.org/en/permalink/ahliterature5271
Source
Tokai J Exp Clin Med. 2004 Dec;29(4):191-8
Publication Type
Article
Date
Dec-2004
Author
Jun Doi
Koichi Shiraishi
Munetaka Haida
Shohei Matsuzaki
Author Affiliation
Department of Gastroenterology, Tokai University Hachioji Hospital, Hachioji, Tokyo 192-0032, Japan.
Source
Tokai J Exp Clin Med. 2004 Dec;29(4):191-8
Date
Dec-2004
Language
English
Publication Type
Article
Keywords
Aged
Amino Acids, Branched-Chain - administration & dosage
Case-Control Studies
Citric Acid Cycle
Comparative Study
Energy Metabolism
Exercise
Fasting
Female
Glucose - administration & dosage - metabolism
Humans
Hydrogen-Ion Concentration
Liver Cirrhosis - metabolism
Magnetic Resonance Spectroscopy
Male
Middle Aged
Muscle, Skeletal - metabolism
Oxygen - metabolism
Phosphocreatine - metabolism
Spectroscopy, Near-Infrared
Abstract
We assessed changes in skeletal muscle energy metabolism by 31P-magnetic resonance spectroscopy (31P-MRS) and oxygen supply by near-infrared spectroscopy (NIR), after exercise and after administration of glucose and a branched-chain amino acids (BCAA), in healthy volunteers and patients with liver cirrhosis. As for the patients with liver cirrhosis, 4 were classified in Child-Pugh Grade A and the other 4 in Grade B. In patients with liver cirrhosis, the intramuscular pH and PCr index (PCr/PCr + Pi) were lower than in healthy subjects after exercise in the fasting state; the deltapH and deltaPCr index were statistically siginificant (p
PubMed ID
15717491 View in PubMed
Less detail

Accuracy of quantitative magnetic resonance and eight-electrode bioelectrical impedance analysis in normal weight and obese women.

https://arctichealth.org/en/permalink/ahliterature258595
Source
Clin Nutr. 2014 Jun;33(3):471-7
Publication Type
Article
Date
Jun-2014
Author
Marja Bosaeus
Therese Karlsson
Agneta Holmäng
Lars Ellegård
Source
Clin Nutr. 2014 Jun;33(3):471-7
Date
Jun-2014
Language
English
Publication Type
Article
Keywords
Adult
Body Composition
Body mass index
Body Weight
Cross-Sectional Studies
Electric Impedance
Electrodes
Female
Humans
Magnetic Resonance Spectroscopy - methods
Middle Aged
Obesity - diagnosis
Plethysmography - methods
Reproducibility of Results
Sweden
Young Adult
Abstract
Quantitative magnetic resonance (QMR) has previously been shown to both overestimate and underestimate average fat mass (FM) in humans. Eight-electrode bioelectrical impedance analysis (BIA) has previously been found biased as well as successfully validated. We report cross-sectional accuracy of QMR and eight-electrode BIA evaluated with air displacement plethysmography (ADP) as reference method.
Fat mass and fat free mass (FFM) by QMR and eight-electrode BIA were evaluated against ADP as reference in 38 normal weight and 30 obese women. Total body water estimates by QMR and eight-electrode BIA were compared.
Fat mass was overestimated by QMR (1 ± 2 kg, p
PubMed ID
23871192 View in PubMed
Less detail

Acylated pregnane glycosides from Caralluma quadrangula.

https://arctichealth.org/en/permalink/ahliterature117305
Source
Phytochemistry. 2013 Apr;88:54-60
Publication Type
Article
Date
Apr-2013
Author
Hossam M Abdallah
Abdel-Moneim M Osman
Hussein Almehdar
Essam Abdel-Sattar
Author Affiliation
Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
Source
Phytochemistry. 2013 Apr;88:54-60
Date
Apr-2013
Language
English
Publication Type
Article
Keywords
Acylation
Antineoplastic Agents - chemistry - pharmacology
Asclepiadaceae - chemistry
Breast Neoplasms - drug therapy
Cell Line, Tumor
Cell Survival - drug effects
Chloroform - chemistry
Female
Glycosides - chemistry - pharmacology
Humans
Magnetic Resonance Spectroscopy
Molecular Structure
Plant Extracts - chemistry
Pregnanes - chemistry - pharmacology
Abstract
In a previous study, the methanolic extract as well as the chloroform fraction of the aerial parts of Caralluma quadrangula (Forssk.) N.E.Br. indigenous to Saudi Arabia showed significant in vitro cytotoxic activity against breast cancer (MCF7) cell line. In a biologically-guided fractionation approach, four acylated pregnane glycosides were isolated from the chloroform fraction of C. quadrangula. The structures of the isolated compounds were elucidated by the analysis of their MS and NMR data. The compounds were identified as 12,20-di-O-benzoylboucerin 3-O-ß-D-digitoxopyranosyl-(1?4)-ß-D-canaropyranosyl-(1?4)-ß-D-cymaropyranoside (1), 12,20-di-O-benzoylboucerin 3-O-ß-D-cymaropyranosyl-(1?4)-ß-D-canaropyranosyl-(1?4)-ß-D-cymaropyranoside (2), 12,20-di-O-benzoylboucerin 3-O-ß-D-glucopyranosyl-(1?4)-ß-D-digitoxopyranosyl-(1?4)-ß-D-canaropyranosyl-(1?4)-ß-D-cymaropyranoside (3) and 12,20-di-O-benzoyl-3ß,5a,12ß,14ß,20-pentahydroxy-(20R)-pregn-6-ene 3-O-ß-D-glucopyranosyl-(1?4)-ß-D-digitoxopyranosyl-(1?4)-ß-D-canaropyranosyl-(1?4)-ß-D-cymaropyranoside (4). The isolated compounds were tested for their cytotoxic activity against breast cancer (MCF7) cell line.
PubMed ID
23312459 View in PubMed
Less detail

Alternative conformations of the x region of human protein disulphide-isomerase modulate exposure of the substrate binding b' domain.

https://arctichealth.org/en/permalink/ahliterature91978
Source
J Mol Biol. 2008 Nov 28;383(5):1144-55
Publication Type
Article
Date
Nov-28-2008
Author
Nguyen Van Dat
Wallis Katrine
Howard Mark J
Haapalainen Antti M
Salo Kirsi E H
Saaranen Mirva J
Sidhu Ateesh
Wierenga Rik K
Freedman Robert B
Ruddock Lloyd W
Williamson Richard A
Author Affiliation
Department of Biochemistry, University of Oulu, FIN-90014 Oulu, Finland.
Source
J Mol Biol. 2008 Nov 28;383(5):1144-55
Date
Nov-28-2008
Language
English
Publication Type
Article
Keywords
Amino Acid Sequence
Crystallography, X-Ray
Humans
Magnetic Resonance Spectroscopy
Models, Molecular
Molecular Sequence Data
Mutant Proteins - chemistry
Mutation - genetics
Protein Disulfide-Isomerases - chemistry
Protein Structure, Secondary
Protein Structure, Tertiary
Recombinant Proteins - chemistry
Spectrometry, Fluorescence
Substrate Specificity
Tryptophan
Abstract
Protein disulphide isomerase (PDI) is a key multi-domain protein folding catalyst in the endoplasmic reticulum. The b' domain of PDI is essential for the non-covalent binding of incompletely folded protein substrates. Earlier, we defined the substrate binding site in the b' domain of human PDI by modelling and mutagenesis studies. Here, we show by fluorescence and NMR that recombinant human PDI b'x (comprising the b' domain and the subsequent x linker region) can assume at least two different conformations in solution. We have screened mutants in the b'x region to identify mutations that favour one of these conformers in recombinant b'x, and isolated and characterised examples of both types. We have crystallised one mutant of b'x (I272A mutation) in which one conformer is stabilized, and determined its crystal structure to a resolution of 2.2 A. This structure shows that the b' domain has the typical thioredoxin fold and that the x region can interact with the b' domain by "capping" a hydrophobic site on the b' domain. This site is most likely the substrate binding site and hence such capping will inhibit substrate binding. All of the mutations we previously reported to inhibit substrate binding shift the equilibrium towards the capped conformer. Hence, these mutations act by altering the natural equilibrium and decreasing the accessibility of the substrate binding site. Furthermore, we have confirmed that the corresponding structural transition occurs in the wild type full-length PDI. A cross-comparison of our data with that for other PDI-family members, Pdi1p and ERp44, suggests that the x region of PDI can adopt alternative conformations during the functional cycle of PDI action and that these are linked to the ability of PDI to interact with folding substrates.
PubMed ID
18801374 View in PubMed
Less detail

112 records – page 1 of 12.