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27 records – page 1 of 3.

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
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Calcium and phosphate balance with quotidian hemodialysis.

https://arctichealth.org/en/permalink/ahliterature184751
Source
Am J Kidney Dis. 2003 Jul;42(1 Suppl):24-9
Publication Type
Article
Date
Jul-2003
Author
Robert M Lindsay
Fayez Alhejaili
Gihad Nesrallah
Rosemary Leitch
Laurie Clement
A Paul Heidenheim
Claude Kortas
Author Affiliation
Optimal Dialysis Research Unit, London Health Sciences Centre, London, Ontario, Canada. robert.lindsay@lhsc.on.ca
Source
Am J Kidney Dis. 2003 Jul;42(1 Suppl):24-9
Date
Jul-2003
Language
English
Publication Type
Article
Keywords
Adult
Aged
Alkaline Phosphatase - blood
Appointments and Schedules
Calcium - metabolism
Calcium Carbonate - administration & dosage
Female
Follow-Up Studies
Hemodialysis Solutions
Hemodialysis, Home - adverse effects - methods
Humans
Hyperparathyroidism, Secondary - blood - etiology
Isoenzymes - blood
Kidney Failure, Chronic - metabolism - therapy
Male
Middle Aged
Ontario - epidemiology
Parathyroid Hormone - blood
Phosphates - metabolism
Prospective Studies
Treatment Outcome
Abstract
Conventional hemodialysis (HD) is associated with profound disturbances in calcium and phosphate metabolism and abnormal parathyroid hormone (PTH) levels. Effects of more frequent HD on calcium and phosphate balance have not been fully elucidated.
The London Daily/Nocturnal Hemodialysis Study examined effects of quotidian HD, either daily HD (n = 11) or nocturnal HD (n = 12), on calcium and phosphate metabolism, bone alkaline phosphatase levels, and intact PTH (iPTH) levels.
Daily HD patients showed a slight decrease in predialysis serum phosphate levels, no changes in phosphate-binder requirements or serum calcium levels, and slight increases in serum bone alkaline phosphatase and iPTH levels. Nocturnal HD patients showed a trend for decreased predialysis phosphate levels, with significantly lower values than daily HD and matched control patients on conventional HD therapy at several times. Phosphate-binder use by nocturnal HD patients was significantly reduced. Both quotidian HD groups showed decreases in calcium x phosphate product, with significantly lower values for nocturnal HD patients (38.11 mg(2)/dL(2)) compared with daily HD and control patients (53.99 and 52.51 mg(2)/dL(2), respectively) at 18 months. Bone alkaline phosphatase levels increased slightly and attained statistical significance compared with baseline values for both quotidian HD groups. A trend for increases in serum iPTH levels, coupled with increasing levels of bone alkaline phosphatase in nocturnal HD patients, led to the decision to increase the dialysate calcium concentration from 5.0 to 7.0 mg/dL. This 1-time adjustment resulted in a reversal of the trend and a return to baseline values.
This study shows the superior control of serum phosphate levels in nocturnal HD patients compared with daily HD or conventional HD patients and the benefits of dialysate with a greater calcium concentration in slow nocturnal HD.
PubMed ID
12830440 View in PubMed
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Change in Emiliania huxleyi Virus Assemblage Diversity but Not in Host Genetic Composition during an Ocean Acidification Mesocosm Experiment.

https://arctichealth.org/en/permalink/ahliterature286113
Source
Viruses. 2017 Mar 08;9(3)
Publication Type
Article
Date
Mar-08-2017
Author
Andrea Highfield
Ian Joint
Jack A Gilbert
Katharine J Crawfurd
Declan C Schroeder
Source
Viruses. 2017 Mar 08;9(3)
Date
Mar-08-2017
Language
English
Publication Type
Article
Keywords
Carbon Dioxide - metabolism
Chlorophyll - analysis
Denaturing Gradient Gel Electrophoresis
Genetic Variation - drug effects
Haptophyta - classification - genetics - isolation & purification - virology
Nitrates - metabolism
Norway
Phosphates - metabolism
Phycodnaviridae - classification - genetics - growth & development - isolation & purification
Seawater - chemistry - microbiology - virology
Abstract
Effects of elevated pCO2 on Emiliania huxleyi genetic diversity and the viruses that infect E. huxleyi (EhVs) have been investigated in large volume enclosures in a Norwegian fjord. Triplicate enclosures were bubbled with air enriched with CO2 to 760 ppmv whilst the other three enclosures were bubbled with air at ambient pCO2; phytoplankton growth was initiated by the addition of nitrate and phosphate. E. huxleyi was the dominant coccolithophore in all enclosures, but no difference in genetic diversity, based on DGGE analysis using primers specific to the calcium binding protein gene (gpa) were detected in any of the treatments. Chlorophyll concentrations and primary production were lower in the three elevated pCO2 treatments than in the ambient treatments. However, although coccolithophores numbers were reduced in two of the high-pCO2 treatments; in the third, there was no suppression of coccolithophores numbers, which were very similar to the three ambient treatments. In contrast, there was considerable variation in genetic diversity in the EhVs, as determined by analysis of the major capsid protein (mcp) gene. EhV diversity was much lower in the high-pCO2 treatment enclosure that did not show inhibition of E. huxleyi growth. Since virus infection is generally implicated as a major factor in terminating phytoplankton blooms, it is suggested that no study of the effect of ocean acidification in phytoplankton can be complete if it does not include an assessment of viruses.
Notes
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PubMed ID
28282890 View in PubMed
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Characterization of a melatonin binding site in Siberian hamster brown adipose tissue.

https://arctichealth.org/en/permalink/ahliterature10933
Source
Eur J Pharmacol. 1997 Nov 27;339(2-3):271-8
Publication Type
Article
Date
Nov-27-1997
Author
S. Le Gouic
C. Atgié
N. Viguerie-Bascands
N. Hanoun
D. Larrouy
L. Ambid
S. Raimbault
D. Ricquier
P. Delagrange
B. Guardiola-Lemaitre
L. Pénicaud
L. Casteilla
Author Affiliation
CNRS UPRESA 5018, UPS, IFR Louis Bugnard, Toulouse, France.
Source
Eur J Pharmacol. 1997 Nov 27;339(2-3):271-8
Date
Nov-27-1997
Language
English
Publication Type
Article
Keywords
Animals
Antioxidants - metabolism
Binding Sites
Binding, Competitive
Brown Fat - chemistry - metabolism
Cricetinae
Cyclic AMP - metabolism
Female
Inositol Phosphates - metabolism
Iodine Radioisotopes - metabolism
Lipolysis - drug effects
Male
Melatonin - metabolism
Phodopus
Receptors, Cell Surface - chemistry - metabolism
Receptors, Cytoplasmic and Nuclear - chemistry - metabolism
Receptors, Melatonin
Research Support, Non-U.S. Gov't
Abstract
Melatonin has been shown, in various rodent species, to mediate photoperiodic effects on body weight and, consequently, fat mass. Pharmacological investigations indicated that the brown adipose tissue of Siberian hamsters possesses a melatonin binding site with a dissociation constant of 570+/-300 pM and a density of 3.2+/-1.8 fmol/mg protein. This binding site can also be detected on mature brown adipocyte membranes. The rank order of potency of a variety of drugs to displace 2-[125I]iodomelatonin from binding sites on Siberian hamster brown adipose tissue was as follows: 2-iodomelatonin > melatonin = prazosin > GR135531 (5-methoxycarbonylamino-N-acetyltryptamine) > N-acetylserotonin > 6-chloromelatonin > S20304 (N-(2-(1-naphthyl)ethyl)cyclobutanecarboxamide) >> methoxamine, phenylephrine, serotonin. Mel(1a) mRNA was not detected by RT-PCR (reverse transcription-polymerase chain reaction) in brown adipose tissue. Melatonin had no effect on either basal or stimulated lipolysis. Moreover, melatonin did not modify intracellular cAMP accumulation or inositol phosphate content. Together, these results suggest that the melatonin binding site characterized in brown adipose tissue is clearly different from the Mel(1) cloned subtype and has some features different from those of the Mel2 subtype.
PubMed ID
9473145 View in PubMed
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Characterization of malignant colon tumors with 31P nuclear magnetic resonance phospholipid and phosphatic metabolite profiles.

https://arctichealth.org/en/permalink/ahliterature4070
Source
Cancer. 1995 Nov 15;76(10):1715-23
Publication Type
Article
Date
Nov-15-1995
Author
T E Merchant
P M Diamantis
G. Lauwers
T. Haida
J N Kasimos
J. Guillem
T. Glonek
B D Minsky
Author Affiliation
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Source
Cancer. 1995 Nov 15;76(10):1715-23
Date
Nov-15-1995
Language
English
Publication Type
Article
Keywords
Cell Differentiation
Colonic Neoplasms - metabolism - pathology
Humans
Lymphatic Metastasis
Magnetic Resonance Spectroscopy
Neoplasm Invasiveness
Phosphates - metabolism
Phospholipids - metabolism
Prognosis
Research Support, Non-U.S. Gov't
Abstract
BACKGROUND. To further characterize selected pathologic features on a biochemical level, the authors analyzed the nuclear magnetic resonance metabolite and phospholipid spectra of 30 malignant colon tumors using 31P magnetic resonance spectroscopy. METHODS. Eleven individual generic phospholipids were identified in the spectra of 17 phospholipid extracts, and 31 individual phosphatic metabolites were identified in the spectra of 13 perchloric acid extracts. The metabolites and lipids were quantified for statistical intergroup comparisons based on tumor stage, lymph node status, differentiation, mucin production, blood vessel invasion (BVI), and lymphatic vessel invasion (LVI). RESULTS. Significant elevations in the relative concentration of alpha-glycerol phosphate were noted when comparing AJCC tumor classification (T3 vs. T2, 0.92 +/- 0.14 vs. 0.46 +/- 0.11, P
PubMed ID
8625039 View in PubMed
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Clostridium perfringens beta-toxin forms multimeric transmembrane pores in human endothelial cells.

https://arctichealth.org/en/permalink/ahliterature10547
Source
Microb Pathog. 2000 Jan;28(1):45-50
Publication Type
Article
Date
Jan-2000
Author
V. Steinthorsdottir
H. Halldórsson
O S Andrésson
Author Affiliation
Institute for Experimental Pathology, University of Iceland, Reykjavik, Keldur, 112, Iceland. vstein@decode.is
Source
Microb Pathog. 2000 Jan;28(1):45-50
Date
Jan-2000
Language
English
Publication Type
Article
Keywords
Animals
Arachidonic Acid - secretion
Bacterial Toxins - chemistry - toxicity
Calcium - metabolism
Calcium-Binding Proteins
Cell Membrane - drug effects
Cells, Cultured
Clostridium perfringens - pathogenicity
Endothelium, Vascular - drug effects
Humans
Inositol Phosphates - metabolism
Mice
Phospholipase C - toxicity
Research Support, Non-U.S. Gov't
Abstract
Beta-toxin is one of the lethal toxins of Clostridium perfringens. It shares sequence homology with the pore-forming alpha-toxin of Staphylococcus aureus and structural homology has been indicated by mutagenesis studies. Human endothelial cells are sensitive to the toxic effect of alpha-toxin and in order to investigate the function of beta-toxin we have looked at the effect of the protein on human umbilical vein endothelial cells. We show that like alpha-toxin beta-toxin induces release of arachidonic acid in a dose dependent manner. In addition we show that both toxins cause leakage of inositol from the cells, consistent with the formation of transmembrane pores. The effect of toxin mutants on endothelial cells correlates with the lethal dose of each mutant in mice. Furthermore, we demonstrate the formation of heat stable toxin multimers in the cell membrane. Multimer formation was not observed on other cell types tested. We conclude that beta-toxin is a cell specific pore-forming toxin, structurally and functionally related to alpha-toxin of Staphylococcus aureus.
PubMed ID
10623563 View in PubMed
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27 records – page 1 of 3.