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1.
Dalton Trans ; 44(37): 16506-15, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26331156

RESUMO

Calcium ionophoretic properties of ferutinin were re-evaluated in solvent-containing bilayer lipid membranes. The slopes of conductance-concentration curves suggest that in the presence of a solvent in the membrane the majority of complexes appear to consist of a single terpenoid molecule bound to one Ca ion. By contrast, the stoichiometry of ferutinin-Ca(2+) complexes in acetone determined using the conductometric method was 2 : 1. While the cation-cation selectivity of ferutinin did not change, the cation-anion selectivity slightly decreased in solvent containing membranes. FT-IR and NMR data together with DFT calculations at the B3LYP/6-31G(d) level of theory indicate that in the absence of Ca ions ferutinin molecules are hydrogen-bonded at the phenol hydroxyl groups. The variations of absorption assigned to -OH and -C-O stretching mode suggest that ferutinin interacts strongly with Ca ions via the hydroxyl group of ferutinol and carboxyl oxygen of the complex ether bond. The coordination through the carbonyl group of ferutinin was demonstrated by theoretical calculations. Taken together, ferutinin molecules form H-bonded dimers, while complexation of Ca(2+) by ferutinin ruptures this hydrogen bond due to spatial re-orientation of the ferutinin molecules from parallel to antiparallel alignment.


Assuntos
Benzoatos/química , Cálcio/química , Complexos de Coordenação/química , Cicloeptanos/química , Bicamadas Lipídicas/química , Sesquiterpenos/química , Compostos Bicíclicos com Pontes/química , Condutometria , Ligação de Hidrogênio , Íons/química , Espectroscopia de Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
3.
Acta Radiol ; 45(8): 803-9, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15690608

RESUMO

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 co-infected individuals, and 24 healthy volunteers. Resonances of lipids, glutamine/glutamate (Glx), phosphomonoesters (PME), glycogen/glucose (Glc) were assessed and metabolite ratios to total lipids (TL) were calculated. RESULTS: A significant increase in Glx/TL and PME/TL was observed in the HCV group as compared to healthy individuals. Patients with HIV and HCV co-infection had a further increase of all metabolite ratios. Changes in metabolite ratios were due to both the increase in particular metabolite contents and to the decrease in lipid levels. HIV/HCV-infected patients treated with highly active anti-retroviral therapy (HAART) showed elevated PME and Glx levels and significantly decreased TL compared to patients not undergoing anti-retroviral treatment. CONCLUSIONS: Our findings suggest clinical usefulness of liver 1H MR spectroscopy in detecting even slight disturbances in liver metabolism.


Assuntos
Infecções por HIV/complicações , Hepatite C/complicações , Hepatócitos/fisiologia , Fígado/metabolismo , Espectroscopia de Ressonância Magnética , Doenças Metabólicas/complicações , Doenças Metabólicas/diagnóstico , Prótons , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
Hepatogastroenterology ; 50(54): 2149-53, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14696484

RESUMO

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 with early stages of hepatic encephalopathy. METHODOLOGY: Twenty patients with liver cirrhosis and 14 patients with grade I-II hepatic encephalopathy were studied with magnetic resonance and proton magnetic resonance spectroscopy. Localized magnetic resonance spectra were acquired in the parietal gray/white matter regions and basal ganglia. Control group consisted of 20 healthy volunteers. RESULTS: Frequency and degree of brain atrophy and bilateral signal hyperintensities in globus pallidus were similar in groups with liver cirrhosis and with encephalopathy. Decreased myoinositol, choline and increased glutamine levels were noted in both groups whereas N-acetylaspartate levels were unchanged. The statistically significant differences between cirrhotic and encephalopathic groups were observed only in myoinositol/creatine ratio in basal ganglia. There were no significant differences in metabolic concentrations between parietal and basal ganglia regions. CONCLUSIONS: Metabolic brain alterations occur earlier than clinical evidence of hepatic encephalopathy but there is no correlation between presence of symptoms encephalopathy and magnetic resonance and magnetic resonance spectroscopy findings.


Assuntos
Ácido Aspártico/análogos & derivados , Encéfalo/fisiopatologia , Metabolismo Energético/fisiologia , Encefalopatia Hepática/diagnóstico , Processamento de Imagem Assistida por Computador , Cirrose Hepática/diagnóstico , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Adulto , Ácido Aspártico/metabolismo , Atrofia , Encéfalo/patologia , Colina/metabolismo , Dominância Cerebral/fisiologia , Feminino , Globo Pálido/patologia , Globo Pálido/fisiopatologia , Glutamina/metabolismo , Encefalopatia Hepática/classificação , Encefalopatia Hepática/fisiopatologia , Humanos , Inositol/metabolismo , Cirrose Hepática/classificação , Cirrose Hepática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Lobo Parietal/patologia , Lobo Parietal/fisiopatologia , Prognóstico , Valores de Referência
5.
Neurol Neurochir Pol ; 35 Suppl 5: 90-100, 2001.
Artigo em Polonês | MEDLINE | ID: mdl-11935688

RESUMO

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 tumors is still not well estimated and the role of each metabolite as an indicator of histopathologic grade and type of the tumor is still unknown. MATERIALS AND METHODS: In vivo 1H MR spectroscopy was prospectively performed in 36 patients with intracranial tumors (low grade gliomas, high grade gliomas, meningiomas and abscesses). Examinations was performed with 1.5 T system, using voxels of 8 cc. RESULTS: In high grade gliomas level of NAA was decreased, and consequently low ratios of NAA to other metabolites were obtained; lactate and choline peaks were markedly increased. In patients with meningiomas signal of NAA was reduced, while in abscesses group peaks of acetate and succinate were observed. Authors analysed ratios of metabolites in above-mentioned tumors. The method is especially useful in differential diagnosis in neoplastic and nonneoplastic cases. CONCLUSIONS: Our study confirms diagnostic value of 1H MRS in doubtful cases of intracranial tumors.


Assuntos
Abscesso Encefálico/diagnóstico , Neoplasias Encefálicas/diagnóstico , Espectroscopia de Ressonância Magnética , Abscesso Encefálico/patologia , Neoplasias Encefálicas/patologia , Estudos de Casos e Controles , Diagnóstico Diferencial , Glioma/diagnóstico , Humanos , Neoplasias Meníngeas/diagnóstico , Meningioma/diagnóstico , Estudos Prospectivos , Prótons , Sensibilidade e Especificidade
6.
Steroids ; 60(2): 195-203, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7618185

RESUMO

The structures of the title compounds have been investigated in solid state by X-ray and in solution by NMR methods. The configurations at C20 and the preferred conformations of both epimers were established. A full assignment of signals in 1H and 13C NMR spectra was done.


Assuntos
Compostos Aza/química , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Noresteroides/química , Isótopos de Carbono , Modelos Moleculares , Prótons , Estereoisomerismo
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