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Michael Ith Peter Bigler Eva Scheurer Roland Kreis Lucie Hofmann Richard Dirnhofer Chris Boesch 《Magnetic resonance in medicine》2002,48(5):915-920
Postmortem decomposition of brain tissue was investigated by (1)H-magnetic resonance spectroscopy (MRS) in a sheep head model and selected human cases. Aiming at the eventual estimation of postmortem intervals in forensic medicine, this study focuses on the characterization and identification of newly observed metabolites. In situ single-voxel (1)H-MRS at 1.5 T was complemented by multidimensional homo- and heteronuclear high-resolution NMR spectroscopy of an extract of sheep brain tissue. The inclusion of spectra of model solutions in the program LC Model confirmed the assignments in situ. The first postmortem phase was characterized mainly by changes in the concentrations of metabolites usually observed in vivo and by the appearance of previously reported decay products. About 3 days postmortem, new metabolites, including free trimethylammonium, propionate, butyrate, and iso-butyrate, started to appear in situ. Since the observed metabolites and the time course is comparable in sheep and human brain tissue, the model system seems to be appropriate. 相似文献
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Stettler R Ith M Acheson KJ Décombaz J Boesch C Tappy L Binnert C 《Diabetes care》2005,28(6):1404-1409
OBJECTIVE: To assess the effect of a possible interaction between dietary fat and physical inactivity on whole-body insulin sensitivity and intramyocellular lipids (IMCLs). RESEARCH DESIGN AND METHODS: Eight healthy male volunteers were studied on two occasions. After 2 days of an equilibrated diet and moderate physical activity, participants remained inactive (bed rest) for 60 h and consumed either a high-saturated fat (45% fat, of which approximately 60% was saturated fat [BR-HF]) or a high-carbohydrate (70% carbohydrate [BR-HCHO]) diet. To evaluate the effect of a high-fat diet alone, six of the eight volunteers were restudied after a 2-day equilibrated diet followed by 60 h on a high-saturated fat diet and controlled physical activity (PA-HF). Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp and IMCL concentrations by (1)H-magnetic resonance spectroscopy. RESULTS: Insulin-mediated glucose disposal was decreased by BR-HF condition (-24 +/- 6%, P < 0.05) but did not change with BR-HCHO (+19 +/- 10%, NS). BR-HF and BR-HCHO increased IMCL levels (+32 +/- 7%, P < 0.05 and +17 +/- 8%, P < 0.0011, respectively). Although the increase in IMCL levels with PA-HF (+31 +/- 19%, P = 0.12) was similar to that during BR-HF, insulin-mediated glucose disposal (-7 +/- 9%, NS) was not decreased. CONCLUSIONS: These data indicate that physical inactivity and a high-saturated fat diet may interact to reduce whole-body insulin sensitivity. IMCL content was influenced by dietary lipid and physical inactivity but was not directly associated with insulin resistance. 相似文献
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Lê KA Faeh D Stettler R Ith M Kreis R Vermathen P Boesch C Ravussin E Tappy L 《The American journal of clinical nutrition》2006,84(6):1374-1379
BACKGROUND: High fructose consumption is suspected to be causally linked to the epidemics of obesity and metabolic disorders. In rodents, fructose leads to insulin resistance and ectopic lipid deposition. In humans, the effects of fructose on insulin sensitivity remain debated, whereas its effect on ectopic lipids has never been investigated. OBJECTIVE: We assessed the effect of moderate fructose supplementation on insulin sensitivity (IS) and ectopic lipids in healthy male volunteers (n = 7). DESIGN: IS, intrahepatocellular lipids (IHCL), and intramyocellular lipids (IMCL) were measured before and after 1 and 4 wk of a high-fructose diet containing 1.5 g fructose . kg body wt(-1) . d(-1). Adipose tissue IS was evaluated from nonesterified fatty acid suppression, hepatic IS from suppression of hepatic glucose output (6,6-2H2-glucose), and muscle IS from the whole-body glucose disposal rate during a 2-step hyperinsulinemic euglycemic clamp. IHCL and IMCL were measured by 1H magnetic resonance spectroscopy. RESULTS: Fructose caused significant (P < 0.05) increases in fasting plasma concentrations of triacylglycerol (36%), VLDL-triacylglycerol (72%), lactate (49%), glucose (5.5%), and leptin (48%) without any significant changes in body weight, IHCL, IMCL, or IS. IHCL were negatively correlated with triacylglycerol after 4 wk of the high-fructose diet (r = -0.78, P < 0.05). CONCLUSION: Moderate fructose supplementation over 4 wk increases plasma triacylglycerol and glucose concentrations without causing ectopic lipid deposition or insulin resistance in healthy humans. 相似文献
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Boss A Kreis R Jenni S Ith M Nuoffer JM Christ E Boesch C Stettler C 《Diabetes care》2011,34(1):220-222
OBJECTIVE
Intramyocellular acetylcarnitine (IMAC) is involved in exercise-related fuel metabolism. It is not known whether levels of systemic glucose influence IMAC levels in type 1 diabetes.RESEARCH DESIGN AND METHODS
Seven male individuals with type 1 diabetes performed 120 min of aerobic exercise at 55–60% of Vo2max randomly on two occasions (glucose clamped to 5 or 11 mmol/l, identical insulinemia). Before and after exercise, IMAC was detected by 1H magnetic resonance spectroscopy in musculus vastus intermedius.RESULTS
Postexercise levels of IMAC were significantly higher than pre-exercise values in euglycemia (4.30 ± 0.54 arbitrary units [a.u.], P < 0.001) and in hyperglycemia (2.44 ± 0.53 a.u., P = 0.01) and differed significantly according to glycemia (P < 0.01). The increase in exercise-related levels of IMAC was significantly higher in euglycemia (3.97 ± 0.45 a.u.) than in hyperglycemia (1.71 ± 0.50 a.u.; P < 0.01).CONCLUSIONS
The increase in IMAC associated with moderate aerobic exercise in individuals with type 1 diabetes was significantly higher in euglycemia than in hyperglycemia.Intramyocellular acetylcarnitine (IMAC) is involved in the regulation of fat and carbohydrate oxidation in skeletal muscle during moderate aerobic exercise (1). Although carnitine metabolism appears comparable in patients with type 1 diabetes and healthy control subjects (2), it is not known whether IMAC is related to variations in fuel metabolism observed during exercise under differing glycemic levels in type 1 diabetes (3). Given the controversial results from previous studies linking IMAC to increased β-oxidation (4) but also to high glycolytic flux (1), the aim of the present study was to assess exercise-related concentrations of IMAC noninvasively by 1H magnetic resonance spectroscopy (1H MRS) (5,6) in patients with type 1 diabetes in euglycemia and hyperglycemia. 相似文献7.
Khoschy?SchawkatEmail author Michael?Ith Andreas?Christe Wolfgang?Kühn Yojena?Chittazhathu Lauren?Bains Val?Murray?Runge Johannes?T.?Heverhagen 《European radiology》2018,28(6):2389-2396
Objectives
To investigate prospectively the repeatability of pancreatic perfusion measurements using arterial spin labelling (ASL) and to determine the increase in perfusion due to secretin stimulation.Material and methods
An (FAIR)-TrueFISP ASL sequence was applied to determine the perfusion of the pancreatic head in a 3T MRI scanner. Ten healthy volunteers (four men, six women: mean age 28.5 ± 4.6 years; age range 25–40 years) were investigated twice within 1 week. The inter-individual variability was calculated using the standard deviation. Intra-individual agreement between the first and second scan was estimated using the Pearson correlation coefficient. A paired Wilcoxon rank-sum test was used to compare perfusion at baseline (BL) and during secretin stimulation.Results
The mean BL perfusion of the pancreatic head was 285 ± 96 mL/100 g/min with an intra-individual correlation coefficient of 0.67 (strong) for repeated measurements. Secretin stimulation led to a significant increase (by 81%) in perfusion of the pancreatic head to 486 ±156 mL/100 g/min (p=0.002) with an intra-individual correlation of 0.29 (weak). A return to BL values was observed after 239 ± 92 s with a moderate intra-individual correlation coefficient of 0.42 for repeat measurements.Conclusion
Dynamic non-invasive ASL imaging of the pancreas permitted quantification of pancreatic perfusion in a clinically applicable setting.Key Points
? ASL imaging of the pancreas permitted quantification of pancreatic perfusion? Secretin stimulation led to a significant increase in pancreatic perfusion? The intra-individual correlation coefficient for baseline perfusion was strong for repeated measurements8.
Micah W. Smith Agnes Ith Eugene J. Carragee Ivan Cheng Todd F. Alamin S. Raymond Golish Kyle Mitsunaga Gaetano J. Scuderi Matthew Smuck 《The spine journal》2019,19(2):e28-e33
Background context
Protein biomarkers associated with lumbar disc disease have been studied as diagnostic indicators and therapeutic targets. Recently, a cartilage degradation product, the fibronectin-aggrecan complex (FAC) identified in the epidural space, has been shown to predict response to lumbar epidural steroid injection in patients with radiculopathy from herniated nucleus pulposus (HNP).Purpose
Determine the ability of FAC to predict response to microdiscectomy for patients with radiculopathy due to lumbar disc herniationStudy design/setting
Single-center prospective consecutive cohort study.Patient sample
Patients with radiculopathy from HNP with concordant symptoms to MRI who underwent microdiscectomy.Outcomes measures
Oswestry disability index (ODI) and visual analog scores (VAS) were noted at baseline and at 3-month follow-up. Primary outcome of clinical improvement was defined as patients with both a decrease in VAS of at least 3 points and ODI >20 points.Methods
Intraoperative sampling was done via lavage of the excised fragment by ELISA for presence of FAC. Funding for the ELISA was provided by Cytonics, Inc.Results
Seventy-five patients had full complement of data and were included in this analysis. At 3-month follow-up, 57 (76%) patents were “better.” There was a statistically significant association of the presence of FAC and clinical improvement (p=.017) with an 85% positive predictive value. Receiver-operating-characteristic (ROC) curve plotting association of FAC and clinical improvement demonstrates an area under the curve (AUC) of 0.66±0.08 (p=.037). Subset analysis of those with weakness on physical examination (n=48) plotting the association of FAC and improvement shows AUC on ROC of 0.81±0.067 (p=.002).Conclusions
Patients who are “FAC+” are more likely to demonstrate clinical improvement following microdiscectomy. The data suggest that the inflammatory milieu plays a significant role regarding improvement in patients undergoing discectomy for radiculopathy in lumbar HNP, even in those with preoperative weakness. The FAC represents a potential target for treatment in HNP. 相似文献9.
Boesch C Ith M Jung B Bruegger K Erban S Diamantis I Kreis R Bär A 《Regulatory toxicology and pharmacology : RTP》2001,33(2):257-267
Standard toxicity tests with high levels of D-tagatose showed a reversible enlargement of the liver in Sprague-Dawley rats without increase of liver enzymes. The present study tests the hypotheses that partial substitution of dietary sucrose by D-tagatose for 28 days increases the volume of human liver and the concentration of liver glycogen. Twelve healthy, male volunteers were studied in a double-blind crossover study with ingestion of D-tagatose (3x15 g daily) and placebo (sucrose, 3x15 g daily) for periods of 28 days each. Liver volume and glycogen concentration have been determined by magnetic resonance (MR) imaging and spectroscopy, which were accompanied by routine medical examinations. MR examinations before and after the treatments revealed no effects (P>0.05) of treatment, period, or subject for changes in liver volume or glycogen concentration. A steady increase of liver volumes, independent of the D-tagatose or placebo intake, has been observed over the study in parallel with a slight increase in body weight. The treatment with D-tagatose was not associated with clinically relevant changes of the examined clinico-chemical and hematological parameters, including liver enzymes and uric acid. 相似文献
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Mordasini P El-Koussy M Schmidli J Bonel HM Ith M Gralla J Schroth G Hoppe H 《European journal of radiology》2012,81(5):979-984