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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

At present in vivo NMR spectroscopic studies of brain glutamate and glutamine concentrations relative to encephalopathy have mainly been performed in hepatic encephalopathy (HE). In vivo proton NMR studies were performed in rats with hyperammonemia and acute HE due to acute liver ischemia as well as in rats with hyperammonemia due to either repeated urease i.p. injection or i.p. administration of methionine sulfoximine, a well known inhibitor of glutamine synthetase. In man, in vivo proton NMR is described in patients with chronic liver disease: cirrhosis of different etiology and associated with different degrees of HE. In the experimental models proton NMR spectroscopy of the cerebral cortex revealed an increase in glutamine concentration, a decrease in glutamate concentration and a decrease in phosphocholine compounds. In humans no clear distinction between cerebral cortex glutamate and glutamine concentration could be made by in vivo 1H NMR spectroscopy. However, the combined glutamate/glutamine peak increased in a way compatible with an increased cerebral cortex glutamine concentration during chronic HE. In the cirrhotic patients too a decrease in cerebral cortex phosphocholine compounds was observed, the explanation of which is unclear. Both the experimental work and the clinical observations support the hypothesis that impairment of the glutamate/glutamine cycle between astrocytes and neurons plays a role in the pathogenesis of hepatic encephalopathy.
NMR Biomed 1991 Apr
PMID:What the clinician can learn from MR glutamine/glutamate assays. 167 85

Localized 1H NMR spectra of human brain in vivo are affected by signal overlap, strong spin-spin coupling, and complex J modulation, and therefore differ considerably from those obtained at higher magnetic fields. This paper deals with the assignment of 1H NMR resonances of cerebral metabolites under the experimental conditions used for human investigations. Conventional 7.0-T FID spectra and 2.0 T localized, short echo time STEAM spectra (TE = 20 ms) of aqueous metabolite solutions are compared to in vivo brain spectra of human volunteers and patients. In addition to singlet resonances from N-acetyl aspartate (NAA), creatines, and cholines, short echo time STEAM spectra exhibit multiplets due to the NAA aspartyl group, glutamate, taurine, and myo-inositol. Enhanced levels of cerebral glutamine are detected in patients with liver cirrhosis. For the first time elevated levels of brain glucose are observed in patients with diabetes mellitus.
NMR Biomed 1991 Apr
PMID:On the identification of cerebral metabolites in localized 1H NMR spectra of human brain in vivo. 167 88

We examined the 1H-NMR spectra of the lipid region of human plasma according to the method of Fossel et al. as the specific blood test for cancer. The study group included 20 patients with hepatocellular carcinoma (HCC), 10 patients with liver cirrhosis (LC) and 10 normal controls (NC). We measured the linewidths of methyl and methylene resonances of lipoprotein lipids at a proton resonance frequency of 400 MHz using a JNM GX400 FT NMR spectrometer. The mean linewidth values and the standard deviation of methyl were as follows: 41.3 +/- 7.2 Hz (NC), 34.8 +/- 6.9 Hz (LC), 29.6 +/- 5.7 Hz (HCC). There was thus a significant difference between NC and HCC. On the other hand, there was no significant difference between the three groups in the case of methylene. Although the spectrum in the HCC and LC groups had a blunt head but narrow body, that of the NC group had a pointed head but wide body, and the linewidth values thus showed wide dispersion. This difference in spectral patterns between the two groups was characteristic. Linewidth values, however, did not correlate well with the laboratory data.
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PMID:[1H-NMR studies of plasma from patients with liver diseases]. 207 59

Diagnosis of Wilson's Disease in the early stages may be elusive in patients presenting without neurological symptoms. A case history is presented which demonstrates the pitfalls in making the diagnosis. Presenting psychiatric symptoms were nonspecific. Ceruloplasmin level was initially elevated to normal range. Liver biopsy showed early nonspecific cirrhosis; staining for copper did not show the dramatic effects expected with Wilson's Disease. Neurological examination, including NMR, was within normal limits. Kayser-Fleischer rings are no longer considered pathognomic. Urinary copper excretion helped to establish the diagnosis.
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PMID:Pitfalls of diagnosis in the early stages of Wilson's disease. 200 54

Clinical studies using 31P and 1H MRS with a whole body 2.0 T MRI/MRS system are described. In most cases, techniques to quantitate absolute molar concentrations of metabolites in various organs were used. In the brain, AIDS, chronic stroke, and white matter lesions were associated with alterations of brain 31P metabolites. Epilepsy was associated with increased pH in the seizure focus. In the heart, dilated cardiomyopathy was associated with increased PDE/ATP while PCr/ATP was unchanged. In the liver, alcoholic hepatitis and cirrhosis were associated with diminished hepatic ATP while alcoholic hepatitis had increased pH and cirrhosis had decreased pH. This allowed differentiation of normal liver, alcoholic hepatitis, and alcoholic cirrhosis without biopsy. In the prostate, malignancy was associated with increased PME/ATP and decreased PCr/ATP. The PME/PCr was greatly increased in malignant prostate with no overlap in normals. Other cancers outside the brain had increased PME and effective treatment was often associated with diminished PME. 1H MRS of the brain was performed using ISIS and outer volume suppression pulses for volume localization. Excellent high resolution 1H water-suppressed spectra were obtained at echo times as short as 30 ms, showing well resolved peaks for lactate, N-acetylaspartate, glutamate, choline, creatinine, and inositol. 1H MRS demonstrated that the uptake of ethanol by the brain was slower than the rise of ethanol in blood. 31P spectroscopic imaging of the brain with resolution of 2.25 x 2.25 x 2.5 cm produced metabolic images and high resolution spectra from desired regions of interest.(ABSTRACT TRUNCATED AT 250 WORDS)
NMR Biomed 1989 Dec
PMID:Clinical magnetic resonance spectroscopy of brain, heart, liver, kidney, and cancer. A quantitative approach. 270 9

In evaluating nuclear magnetic tomography for the diagnosis of liver disease, one must differentiate between circumscribed and diffuse lesions. Nuclear magnetic tomography provides additional information for lesions which are echogenic on ultrasound and can differentiate between metastases, haemangiomas and hamartomas. In diffuse parenchymal disease measurement of relaxation time can differentiate between fatty liver, cirrhosis (alcoholic, primary biliary), haemochromatosis (cirrhotic transformation) and hepatoma. NMR spectroscopy is a method for the future.
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PMID:[Differential diagnosis of liver diseases in the nuclear spin tomogram]. 298 31

The relaxation times of water protons in rat liver tissue were measured with a NMR spectrometer at 20 MHz. The paramagnetic trace elements Cu, Fe, and Mn were determined by neutron activation analysis. No shortening of T1 could be observed when liver Cu or Fe concentration was increased in the microgram range. T1 was strongly correlated with the liver Mn concentration of untreated animals and animals whose liver Mn concentration was artificially increased or decreased by intravenous injection of manganous acetate or a metal chelating agent with high affinity for hepatobiliary excretion. Deviations from this Mn-T1 correlation were found in the initial phase of liver cirrhosis induced by thioacetamide (elongated T1, normal Mn concentration) and after stimulation of liver growth by phenobarbital (normal T1, decreased Mn concentration). An increased or decreased enhancement factor for Mn may have contributed to the observed deviations during phenobarbital and thioacetamide treatment.
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PMID:Contribution of paramagnetic trace elements to the spin-lattice relaxation time in the liver. 299 26

Human livers with histologically proven cirrhosis were assessed using in vitro 31P NMR spectroscopy. Spectra were compared with those from histologically normal livers and showed significant elevations in phosphoethanolamine (PE) and phosphocholine (PC) and significant reductions in glycerophosphorylethanolamine (GPE) and glycerophosphorylcholine (GPC). There were no significant differences in spectra from livers with compensated and decompensated cirrhosis. These results help to characterise the alterations in membrane metabolism in cirrhosis of the liver.
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PMID:Cirrhosis of the human liver: an in vitro 31P nuclear magnetic resonance study. 754 34

Fourteen patients with liver cirrhosis of differing severity participated in a one-dimensional chemical shift imaging 31P MRS study of the liver. Patients were divided into two groups according to the severity of their liver disease using Child's classification and the aminopyrine breath test (AB test). Seven normal volunteers without liver disease acted as controls. The phosphomonester (PME) peak in normal subjects was 4.77% (95% confidence interval, CI: 4.11-5.42) of total phosphorus. The PME peak was significantly elevated in both mild cirrhosis [5.80% (95% CI: 5.46-6.14), p = 0.0051, vs normal subjects] and severe cirrhosis [9.64% (95% CI: 8.71-10.57), p = 0.0002, vs normal subjects and p = 0.001, vs mild cirrhosis]. There was a significant negative linear correlation (r = 0.88, p < 0.01) of PME with the percentage dose of 14CO2 excreted over 2 h in the AB test. pH values in patients with mild cirrhosis [7.45 (95% CI: 7.35-7.55)] but not severe cirrhosis [7.36 (95% CI: 7.25-7.47)] were significantly elevated (p = 0.04) compared to normal subjects [7.29 (95% CI: 7.17-7.41)]. Comparison of the peak area of PME at TR = 0.5 s against that using TR = 5.0 s in cirrhotic liver suggested no reduction in T1 of phosphorus metabolites in cirrhosis. A relationship between the severity of liver cirrhosis and a relative increase in PME was demonstrated and this was not due to a reduction of T1. This study highlights the clinical potential of 31P MRS as a non-invasive means of assessing the severity of liver cirrhosis.
NMR Biomed
PMID:An in vivo 31P MRS study of patients with liver cirrhosis: progress towards a non-invasive assessment of disease severity. 849 48

The role of water of hydration in proton relaxation in tissues as exemplified by hydrated collagen in beef tendon was studied as a function of temperature from -40 degrees to 37 degrees C by using cross-relaxation spectroscopy. Experimental data were fitted to a simple binary spin-bath model. The outcome of this procedure allows the construction of a semi-quantitative depiction of proton relaxation in a heterogeneous system and its change as one of the water fractions freezes at about -10 to -20 degrees C, a transition observed by NMR and confirmed independently by differential scanning calorimetry. Such physical depiction provides a crude but insightful interpretation of the role "bound" water plays in proton relaxation. This may be important in shedding light on the mechanism of tissue relaxation and its role in MRI diagnosis, particularly for those diseases such as liver cirrhosis where the water-macromolecular interaction plays a prominent role.
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PMID:Temperature dependence and phase transition of proton relaxation of hydrated collagen in intact beef tendon specimens via cross-relaxation spectroscopy. 905 25


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