An unknown intense signal (Pun ) with a mean chemical shift of 5.3 ppm was observed in 31 P MR spectra from the calf muscles of patients with the diabetic foot syndrome. The aim of the study was to identify the origin of this signal and its potential as a biomarker of muscle injury. Calf muscles of 68 diabetic patients (66.3 ± 8.6 years; body mass index = 28.2 ± 4.3 kg/m2 ) and 12 age-matched healthy controls were examined by (dynamic) 31 P MRS (3 T system, 31 P/1 H coil). Phantoms (glucose-1-phosphate, Pi and PCr) were measured at pH values of 7.05 and 7.51. At rest, Pun signals with intensities higher than 50% of the Pi intensity were observed in 10 of the 68 examined diabetic subjects. We tested two hypothetical origins of the Pun signal: (1) phosphorus from phosphoesters and (2) phosphorus from extra- and intracellular alkaline phosphate pools. 2,3-diphosphoglycerate and glucose-1-phosphate are the only phosphoesters with signals in the chemical shift region close to 5.3 ppm. Both compounds can be excluded: 2,3-diphosphoglycerate due to the missing second signal component at 6.31 ppm; glucose-1-phosphate because its chemical shifts are about 0.2 ppm downfield from the Pi signal (4.9 ppm). If the Pun signal is from phosphate, it represents a pH value of 7.54 ± 0.05. Therefore, it could correspond to signals of Pi in mitochondria. However, patients with critical limb ischemia have rather few mitochondria and so the Pun signal probably originates from interstitia. Our data suggest that the increased Pun signal observed in patients with the diabetic foot syndrome is a biomarker of severe muscular damage.
- MeSH
- fantomy radiodiagnostické MeSH
- fosfor chemie MeSH
- ischemie diagnostické zobrazování MeSH
- koncentrace vodíkových iontů MeSH
- končetiny diagnostické zobrazování patologie MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie * MeSH
- odpočinek MeSH
- počítačové zpracování signálu * MeSH
- senioři MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
Magnetic Resonance (MR) compatible ergometers are specialized ergometers used inside the MR scanners for the characterization of tissue metabolism changes during physical stress. They are most commonly used for dynamic phosphorous magnetic resonance spectroscopy (31P MRS), but can also be used for lactate production measurements, perfusion studies using arterial spin labelling or muscle oxygenation measurements by blood oxygen dependent contrast sequences. We will primarily discuss the importance of ergometers in the context of dynamic 31P MRS. Dynamic 31P MRS can monitor muscle fatigue and energy reserve during muscle contractions as well as the dynamics of recuperation of skeletal muscle tissue during the following recovery through signal changes of phosphocreatine (PCr), inorganic phosphate and adenosine triphosphate (ATP). Based on the measured data it is possible to calculate intracellular pH, metabolic flux of ATP through creatine-kinase reaction, anaerobic glycolysis and oxidative phosphorylation and other metabolic parameters as mitochondrial capacity. This review primarily focuses on describing various technical designs of MR compatible ergometers for dynamic 31P MRS that must be constructed with respect to the presence of magnetic field. It is also expected that the construction of ergometers will be easy for the handling and well accepted by examined subjects.
Souhrn: Úvod: Inzulinová rezistence (IR) má velký význam v patogenezi nealkoholové tukové nemoci jater a dalších onemocnění. Údaje o prevalenci a vývoji IR u pacientů před transplantací jater (LT – liver transplantation) a po ní jsou omezené. Cílem naší prospektivní studie bylo zhodnocení prevalence a vývoje IR u pacientů před LT a v prvních 2 letech po LT. Metody: U 77 pacientů zařazených na čekací listinu k LT v období 5/ 2015–4/ 2017 bylo před LT, 6 měsíců (M), 1 rok (R) a 2R po LT provedeno klinické a laboratorní vyšetření a elastografie jater, 1H magnetickou rezonanční (1H MR) spektroskopií byl stanoven obsah tuku v játrech. V 1 a 2 letech po LT byla provedena necílená biopsie jater. Výsledky: IR definovanou jako HOMA-IR (Homeostasis Assessment Model) ≥ 3,0 mělo 26 pacientů (41,3 %) před LT, 16 pacientů (25,4 %) v 6M po LT, 22 pacientů (34,9 %) v 1R po LT a 29 pacientů (46,0 %) ve 2R po LT (p = 0,028 pro 2R vs. 6M). Předtransplantační IR korelovala s věkem, indikací k LT a přítomností metabolického syndromu. IR hodnocená 2R po LT korelovala s přítomností metabolického syndromu, hypertenze, diabetu, body mass indexu, gamaglutamyltransferázy, s množstvím jaterního tuku hodnoceného histologicky i 1H MR spektroskopií, se stupněm balonové degenerace v biopsii a se stupněm fibrózy dle shear wave elastografie. Závěr: Prevalence IR je vysoká u pacientů před i po LT, významně stoupá s rostoucí dobou od LT. Výskytu potransplantační IR a souvisejících faktorů je třeba věnovat maximální péči.
Introduction: Insulin resistance (IR) plays an important role in the pathogenesis of nonalcoholic fatty liver disease and other diseases. Data regarding the prevalence and evolution of IR in patients before and after liver transplantation (LT) are limited. This prospective study aimed to evaluate the prevalence and evolution of IR in patients before and within 2 years (Y) after LT. Methods: In 77 patients listed for LT from May 2015 to April 2017, clinical, laboratory, and elastographic evaluations were performed before LT and 6 months (M), 1Y, and 2Y after LT. The liver fat content was also determined by 1H magnetic resonance (1H MR) spectroscopy. Liver graft biopsy was performed at 1Y and 2Y after LT. Results: IR defined as HOMA-IR ≥ 3.0 was found in 26 patients (41.3%) before LT, 16 patients (25.4%) at 6M after LT, 22 patients (34.9%) at 1Y after LT, and 29 patients (46.0%) at 2Y after LT (P = 0.028 for 2Y vs. 6M). Pretransplant IR correlated with age, indication for LT, and the presence of metabolic syndrome. IR at 2Y after LT correlated with the presence of metabolic syndrome, hypertension, and diabetes mellitus, body mass index, the level of gamma-glutamyl transferase, the liver fat content estimated both histologically and by 1H MR spectroscopy, the grade of ballooning in liver biopsy, and the fibrosis stage estimated by shear wave elastography. Conclusion: The prevalence of IR is high in patients both before and after LT, and increases significantly with time after LT. Great attention should be paid to posttransplant IR and associated factors.
- MeSH
- elastografie MeSH
- inzulinová rezistence * MeSH
- metabolický syndrom MeSH
- nealkoholová steatóza jater diagnostické zobrazování diagnóza komplikace MeSH
- nemoci jater diagnostické zobrazování diagnóza komplikace MeSH
- prevalence MeSH
- prospektivní studie MeSH
- transplantace jater * MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
Autologous cell therapy (ACT) is a new treatment method for diabetic patients with critical limb ischemia (CLI) not eligible for standard revascularization. After intramuscular injection of bone marrow-derived mononuclear cells local arteriogenesis in the ischemic tissue occurs. Studies assessing visualization of this therapeutic vasculogenesis after ACT by novel imaging techniques are lacking. The aim of our study was to assess the effect of ACT on possible metabolic changes and perfusion of critically ischemic limbs using (31)P magnetic resonance spectroscopy ( (31)P MRS) and its possible correlation with changes of transcutaneous oxygen pressure (TcPO(2)). Twenty-one patients with diabetes and no-option CLI treated by ACT in our foot clinic over 8 years were included in the study. TcPO(2) as well as rest (phosphocreatine, adenosine triphosphate and inorganic phosphate) and dynamic (mitochondrial capacity and phosphocreatine recovery time) (31)P-MRS parameters were evaluated at baseline and 3 months after cell treatment. TcPO(2) increased significantly after 3 months compared with baseline (from 22.4±8.2 to 37.6±13.3 mm Hg, p=0.0002). Rest and dynamic (31)P MRS parameters were not significantly different after ACT in comparison with baseline values. Our study showed a significant increase of TcPO(2) on the dorsum of the foot after ACT. We did not observe any changes of rest or dynamic (31)P MRS parameters in the area of the proximal calf where the cell suspension has been injected into.
- MeSH
- autologní transplantace metody MeSH
- bérec diagnostické zobrazování krevní zásobení patologie MeSH
- ischemie diagnostické zobrazování metabolismus terapie MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie metody MeSH
- následné studie MeSH
- radioizotopy fosforu MeSH
- transplantace kostní dřeně MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
BACKGROUND: Diets rich in fat and added sugars (especially fructose) play an important role in the pathogenesis of nonalcoholic liver disease (NAFLD), but there is only limited information on the acute effects of these nutrients on hepatic fat content (HFC). OBJECTIVES: We therefore explored how the administration of high-fat load, glucose, fructose, and combinations thereof affects HFC measured in vivo using proton magnetic resonance spectroscopy (1H-MRS) in healthy subjects. METHODS: Ten healthy nonsteatotic male volunteers (age 38.5 ± 9.6 y, body mass index [BMI, kg/m2] 26.9 ± 2.7) underwent, in random order, 6 experiments, each lasting 8 h, that included: 1) fasting; 2) a high-fat load (150 g of fat [dairy cream] at time 0); 3) glucose (3 doses of 50 g at 0, 2, and 4 h); 4) a high-fat load with glucose; 5) fructose (3 doses of 50 g at 0, 2, and 4 h); and 6) a high-fat load with fructose. HFC was measured using 1H-MRS prior to test meal administration (before time 0) and at 3 and 6 h. Plasma concentrations of triglycerides, nonesterified fatty acids, glucose, and insulin were monitored throughout each experiment. RESULTS: HFC increased to 119 ± 19% (P < 0.05) and 117 ± 17% (P < 0.01) of baseline when subjects consumed a high-fat load alone or a high-fat load with fructose, respectively, but was not affected when glucose was coadministered with a high-fat load. HFC was not affected when subjects had fasted or had consumed repeated doses of fructose. When subjects were administered 3 doses of glucose, HFC dropped to 85 ± 13% (P < 0.05) of baseline. CONCLUSIONS: Our results demonstrate that fructose and glucose have a different immediate impact on HFC in humans in vivo. Clinical trial registry: The study was registered at clinicaltrials.gov and obtained clinicaltrials.gov identifier: NCT03680248.
- MeSH
- dospělí MeSH
- fruktosa metabolismus MeSH
- glukosa metabolismus MeSH
- inzulin krev MeSH
- játra metabolismus MeSH
- kyseliny mastné neesterifikované krev MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- triglyceridy krev MeSH
- tuky metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
- Publikační typ
- abstrakt z konference MeSH
