Leszek Siergiejczyk

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Metabolic and morphologic abnormalities as well as disturbances in bone mineral density (BMD) are prevalent among HIV-infected patients, particularly during highly active antiretroviral treatment (HAART) [1–3]. Hyperlipidaemia may affect up to 60–80% of HIV-infected patients treated with protease inhibitors (PI) and is commonly associated with abnormalities(More)
BACKGROUND Magnetic resonance proton spectroscopy ((1)H MRS) is a non-invasive method that provides in vivo measurement of metabolic concentrations in body tissue. However, relatively little is known about the potential of 1H MR spectroscopy for the quantification of liver metabolites. The aim of this study was to determine the usefulness of (1)H MRS in(More)
BACKGROUND/AIMS Hepatic encephalopathy is a serious problem in patients with liver cirrhosis and precise pathophysiological mechanisms responsible for encephalopathy are not fully understood. Magnetic resonance imaging and magnetic resonance spectroscopy can be used to detect specific morphological and metabolic abnormalities in the brain even in patients(More)
Syntheses of "glycospirostanes" from 3beta-hydroxy-23,24-dinor-5alpha-cholano-22,16-lactone and 3alpha-hydroxy-23,24-dinor-5beta-cholano-22,16-lactone were performed. The key step of these syntheses was ring-closing metathesis of the corresponding C,O-diallyl derivative. Further elaboration of the six-membered ring F consisted of allylic hydroxylation with(More)
The first synthesis of 22-isospirostane derivatives is described. They were obtained by photochemical isomerization of 23-oxosapogenins. The structure of 23-oxo-22-isotigogenin acetate (12) was proved by a single crystal X-ray diffraction, while structures of 23-oxo-22-isodiosgenin acetate (13) and 23-oxo-22-isosarsasapogenin acetate (14) were elucidated by(More)
BACKGROUND The aim of this study was to evaluate the relationship between N-acetylaspartate (NAA) levels in selected brain regions and cognitive performance in patients with first-episode schizophrenia. MATERIAL/METHODS Thirty patients (20 male, 10 female; mean age: 22.5 years) with the diagnosis of first-episode schizophrenia and 19 comparable healthy(More)
PURPOSE To evaluate proton magnetic resonance spectroscopy (1H MRS) features in order to assess hepatocellular activation in chronic hepatitis C and human immunodeficiency virus/hepatitis C (HIV/HCV) co-infected patients. MATERIAL AND METHODS Liver in vivo 1H MR spectra were obtained in 14 patients with hepatitis C virus infection (HCV), 20 HIV/HCV(More)
UNLABELLED MR proton spectroscopy (1H MRS) has been widely applied in characterisation and differentiation of brain tumors, staging, recurrence of pathologic process, post radiotherapy changes and other lesions mimicking neoplasm like abscesses. Despite of many studies performed over last 3 years in many countries spectroscopic pattern (phenotype) of brain(More)
A new electrochemical glycosylation method is presented. According to the method cholesterol and other 3beta-hydroxy-Delta(5)-steroids can be selectively transformed to glycosides using non-activated sugars. The method is also useful for the synthesis of glycoconjugates with sugar linked to a steroid moiety by an ether bond.
Several derivatives of cholesterol and other 3β-hydroxy-Δ(5)-steroids were prepared and tested as sterol donors in electrochemical reactions with sugar alcohols. The reactions afforded glycoconjugates with sugar linked to a steroid moiety by an ether bond. Readily available sterol diphenylphosphates yielding up to 54% of the desired glycoconjugate were(More)