A possible new diagnostic biomarker in early diagnosis of Alzheimer's disease.

Early diagnosis in patients with Alzheimer's disease (AD) is of great importance since only a sufficient treatment in early stages of this disease helps to keep patients in an autonomous state for as long as possible. Until now, there is no single diagnostic biomarker for AD derived from material routinely obtained. In this study, proton nuclear magnetic resonance (1H-NMR) spectra of the cerebrospinal fluid (CSF) of AD patients were compared with 1H-NMR spectra of the CSF of healthy control subjects using a metabonomic approach. The 1H-NMR spectra of CSF of AD patients showed specific multiplets at 2.15 ppm and 2.45 ppm, which could not be detected in the majority (59.3% and 70.4%, respectively) of healthy control subjects (positive likelihood ratio (+LR) 2.33, 95% CI [1.46, 3.72], p<0.01; +LR 3.22, 95% CI [1.78, 5.78], p<0.01). Moreover, CSF 1H-NMR spectra of AD patients showed specific resonances at 7.03 ppm (+LR 3.38, 95% CI [1.60, 7.14], p<0.05), 7.19 ppm (+LR 2.89, 95% CI [1.46, 5.74], p<0.05), 7.43 ppm (+LR 3.15, 95% CI [1.47, 6.75], p<0.05), and at 7.91 ppm (+LR 3.38, 95% CI [1.60, 7.14], p<0.01). CSF 1H-NMR spectroscopy is obviously a capable method for detection and quantification of substances in the CSF of AD patients even without the knowledge of molecular structures. These substances can be used as a biomarker in the early diagnosis of AD. We assume that this biomarker will simplify the diagnosis of AD, especially in early stages of the disease.

N-acetylcysteine decreases lactate signal intensities in liver tissue and improves liver function in septic shock patients, as shown by magnetic resonance spectroscopy: extended case report.

BACKGROUND: N-acetylcysteine (NAC) has been shown to improve splanchnic blood flow in experimental studies. This report evaluates the effects of NAC on liver perfusion and lactate signal intensities in the liver tissue of septic shock patients using proton magnetic resonance imaging and spectroscopy. Furthermore, the monoethylglycinexylidide (MEGX) test was used to investigate hepatic function. METHODS: Five septic shock patients received 150 mg/kg body weight NAC as an intravenous bolus injection over 15 min. Lidocaine was injected both prior to and following NAC administration in order to determine MEGX formation. Measurements (hemodynamics, oxygen transport-related variables, blood samples for lactate, liver-related markers) were performed 1 hour before and 1 hour after NAC injection. In addition to the proton magnetic resonance imaging patients received two proton magnetic resonance spectra, one prior to and one 30 min subsequent to the onset of the NAC infusion at a 1.5 Tesla clinical scanner, for measurement of liver perfusion and liver lactate signal intensity. MAIN FINDINGS: Following NAC infusion, the lactate signal intensity in the liver tissue showed a median decrease of 89% (11-99%), there was a median increase in liver perfusion of 41% (-14 to 559%), and the MEGX serum concentration increased three times (1.52-5.91). CONCLUSIONS: A decrease in the lactate signal intensity in the liver tissue and an increase in the MEGX serum concentration and in liver perfusion might indicate improved liver function as a result of NAC administration. Patients with compromised hepatosplanchnic function, such as patients with septic shock due to peritonitis, may therefore benefit from NAC therapy.