摘要:

AbstractMore than 50% of cancers fail to respond to any individual treatment and tumour follow‐up after treatment plays a major role in routine therapy planning and pharmacological research. Today, MRS is the only technological approach providing non‐invasive access to tumour biochemistry. Ten years ago, expectations were raised concerning31P MRS as an exciting and promising technical approach to the study of tumours. However the expectations have not always come to fruition. How close are we now to seeing routine31P NMR in clinical oncology? This review of the 127 published papers shows spectroscopy results in more than 150 experimental animal tumour models. These tumour/host/treatment systems provide us with a useful basis to evaluate the current state of the art, summarize the basic knowledge presently available, determine the key points underlying the present disappointment of some clinical oncologists and stimulate new basic research. The information collected concerns the discussion of the reliability of experimental models in oncology, the technical improvement of magnetic resonance technology and the monitoring of bioenergetic status, pH regulation and phospholipid metabolism in treated and untreated tumours. Recent advances (two‐thirds of the papers have been published in the last 5 years) seem to provide more optimistic perspectives than those generally accepted a few years ago, in the depressing period following early pioneering

ISSN:0952-3480    

DOI:10.1002/nbm.1940060602

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThis work presents a new method for localizedT1measurements, based upon the OSIRIS scheme. It relies on the use of a non‐selective 180° pulse applied before the OSIRIS preparation cycle. The accuracy of the method has been verified with test tubes andin vivofor two nuclei,1H and19F. The accuracy of theT1values is discussed, as well as possible applications of the inversion‐recovery method to non‐invasivein vivopO2measur

ISSN:0952-3480    

DOI:10.1002/nbm.1940060603

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractWe report on the13C NMR visibility of the C‐1 glycosidic carbon of α‐particulate glycogen in perfused rat liver. We used rats fedad libitum, animals refed after a 48 h fast with a sucrose supplement with or without glucocorticoid treatment, andgsd/gsdrats with a hepatic glycogen storage disease due to phosphorylase kinase deficiency. Thus we studied a wide range of glycogen levels (25‐140 mg/g liver). All livers were perfused with 15 mM glucose, to maintain constant glycogen levels. Failure to activate glycogen phosphorylase ensures stable glycogen levels ingsd/gsdlivers. Natural abundance13C NMR signals were calibrated against a phantom containing a fixed amount of glycogen. Accumulated free induction decays were analysed after Fourier transformation by numerical integration, or by direct analysis of the signal in the time domain using a non‐iterative method based on singular value decomposition. NMR quantification of the glycogen correlated well with the chemical determination over the whole concentration range. However, the precision (reproducibility) of glycogen determinations (be it by chemical methods or by NMR spectroscopy) may pose problems. Authors should be encouraged to report systematically on the precision of their

ISSN:0952-3480    

DOI:10.1002/nbm.1940060604

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

Abstract19F one‐dimensional chemical shift imaging and one‐pulse techniques were used to follow the uptake of isoflurane in rabbit brainin vivo. Brain isoflurane appeared mainly in two adjacent slices of cerebral cortex. Both slices showed increase in anesthetic content at similar rates. A biphasic first‐order uptake pattern with an initial fast component and a slower rate for the duration of the uptake was observed by the one‐pulse technique. Only the slower kinetic was followed by chemical shift imaging due to constraints on temporal resolution. Anesthetic levels in arterial blood reached equilibrium significantly earlier than in brain, suggesting a ‚restricted’︁ diffusion into brain tissue f

ISSN:0952-3480    

DOI:10.1002/nbm.1940060605

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractFour31P NMR spectroscopy parameters were measured non‐invasively in the liver of 11 healthy pigs and 9 pigs with CCI4‐induced liver disease: (i) absolute molar concentration of phosphorous metabolites; (ii) pH based on the chemical shift of the Pipeak; (iii)T1of the peaks in the31P NMR spectrum; and (iv) changes in ATP, Piand phosphomonoester after fructose administration. Liver disease was verified by histology and blood chemistry. The concentration of ATP decreased from 3.0(2.8–3.1) to 2.0(2.0–2.4) mM (median and quartiles) when liver disease was induced (p<0.05). The concentration of phosphodiesters (PDEs) decreased from 14.8(11.4–19.5) to 8.7(7.4–11.6) mM (p<0.05). pH increased by 0.1 unit.Tirelaxation times for the γ‐, α‐ and β‐ATP peaks increased from 320(249–471) to 577(506–638) ms (p<0.01), from 765(611–786) to 906(820–1058) ms (p<0.05) and from 402(327–509) to 579(543–743) ms (p<0.01), respectively, whileT1for the PDE peak decreased from 2204(1909–2404) to 1758(1502‐1894) ms (p<0.05). In the healthy animals injection of fructose was followed by a reduction of ATP (β‐ATP). In diseased livers this reduction was significantly smaller. In conclusion, it was possible non‐invasively to show differences between healthy and diseased livers in all NMR parameters evaluated. This means that31P NMR Spectroscopy may have a potential as a non‐invasive d

ISSN:0952-3480    

DOI:10.1002/nbm.1940060606

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

ISSN:0952-3480    

DOI:10.1002/nbm.1940060601

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY