In vivo 19F-NMR study of halothane distribution in brain

Wyrwicz, Alice M.; Conboy, Claire B.; Nichols, Brenda G.; Ryback, Kenneth R.; Eisele, Pamela H.

doi:10.1016/0167-4889(87)90253-9

Cited by 31 publications

(9 citation statements)

References 16 publications

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“…It does seem clear, however, that halothane is detectable in the brain using IgF MRS up to 90 min after a relatively short anesthetic. Previous animal studies that have addressed this issue are in conflict; although some studies have shown that halothane is detectable in mousehat brain up to 6.5 h after a relatively prolonged anesthetic with halothane (5), other authors have reported that halothane retention in the brain is much less prolonged (6), and there is evidence to suggest that some of the more persistent signal may have arisen from trifluoroacetate (15). The use of "F MRS to obtain precise pharmacokinetic data will require better volume localization.…”

Section: In Vivo 19f Mrs Of Halothane In Postoperative Patientsmentioning

confidence: 92%

“…One possibility is that both these resonances arise from halothane itself, in two different physicochemical environments, as suggested by Evers et al (4). Alternatively, one of the resonances may be due to a metabolite of halothane, perhaps trifluoroacetate (15). However, previous reports have indicated that, in animal brain at least, the separation between the halothane and trifluoroacetate resonances is less than 1 Previous ex vivo studies (16) and our phantom data do suggest that the chemical shift of halothane may vary with environment to an extent that may account for the two separate resonances.…”

Section: In Vivo 19f Mrs Of Halothane In Postoperative Patientsmentioning

confidence: 94%

“…Five hundred twelve data points were acquired with a sweep width of 10 kHz. Spectra were zero-filled to 1024 points and subjected to 10 to 15 Hz line broadening prior to Fourier transformation. The spin-lattice relaxation time constant (TI) was estimated using standard formulae (12).…”

Section: Methodsmentioning

confidence: 99%

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In vivo fluorine‐19 magnetic resonance spectroscopy of cerebral halothane in postoperative patients: Preliminary results

Menon

Lockwood

Peden

et al. 1993

Magnetic Resonance in Med

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This study reports the use of 19F MRS to study halothane in the brain of eight patients recovering from halothane anesthesia of short duration. Resonances attributable to halothane were observed up to 90 min after withdrawal of the anesthetic agent. The signal-to-noise ratio for an unlocalized spectrum acquired using a 6 cm surface coil was typically 20 with data collection times of 2 min. In seven patients a single resonance was seen with a mean (+/- SD) chemical shift of +43.3 (+/- 1.8) ppm, referenced to NaF at 0 ppm. This resonance exhibited a T1 value of between 0.5 and 1 s, and a T2* (estimated from the linewidth of the resonance) between 3.5 and 10 ms. In one patient two resonances were observed with chemical shifts of +38 and +41 ppm. Because we cannot exclude the possibility that this was due to field inhomogeneity, the significance of the last finding is uncertain. However, phantom studies show that the chemical shift of halothane in different environments (such as water, olive oil, methanol, and lecithin) can vary to an extent that accounts for the two resonances seen in our patient. These results demonstrate the feasibility of in vivo 19F MRS studies of fluorinated volatile agents in humans. The potential for clinical 19F MRS of fluorinated anesthetics is discussed.

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Section: In Vivo 19f Mrs Of Halothane In Postoperative Patientsmentioning

confidence: 92%

Section: In Vivo 19f Mrs Of Halothane In Postoperative Patientsmentioning

confidence: 94%

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In vivo fluorine‐19 magnetic resonance spectroscopy of cerebral halothane in postoperative patients: Preliminary results

Menon

Lockwood

Peden

et al. 1993

Magnetic Resonance in Med

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“…Wyrwicz and co-workers [329][330][331][332][333][334][335][336] addressed the issue of Such trapping is apparently a requisite, though not in itself residence times of anesthetics in the brain and observed sufficient for efficacy [21]. signals for the anesthetics for prolonged durations after cessation of anesthesia.…”

Section: Metabolism Of Fluoropyrimidine Drugsmentioning

confidence: 99%

“…signals for the anesthetics for prolonged durations after cessation of anesthesia. Both halothane [330] and isoflurane 5FU requires anabolic conversion to nucleosides (e.g.,…”

Section: Metabolism Of Fluoropyrimidine Drugsmentioning

confidence: 99%

Breast Cancer Gene Therapy: Development of Novel Non-Invasive Magnetic Resonance Assay to Optimize Efficacy

Mason¹

2005

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Public reporting burden for this collection of information Is estimated to average 1 hour per response, Including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, ABSTRACT (Maximum 200 Words)Gene therapy holds great promise for treatment of breast cancer. In particular, clinical trials are underway to apply therapeutic genes related to pro-drug activation or to modulate the activity of oncogenes by blocking promoter sites. However, there are major problems in terms of assessing the delivery to target tissue, assessing the uniformity (versus heterogeneity) of biodistribution and determining whether the genes are expressed. We propose to design, evaluate and apply a novel approach to gene activity detection-specifically, using fluorinated substrates of P-galactosidase to reveal gene activity. Our prototype molecule PFONPG (para-fluoro-ortho-nitro-phenyl P3-D-galactopyranoside) is a direct analog of the traditional "yellow' biochemical indicator ONPG (ortho-nitro-phenyl 3-D-galactopyranoside). This shows useful MR characteristics, sensitivity to enzyme activity and ability to enter cells. We will synthesize analogs of this prototype to optimize MR and biological characteristics and explore the feasibility of tailoring the reporter to specific applications, e.g., exploiting P-gal activity to deliver specific physiological reporter molecules such as pH and potentially specific cytotoxic agents. The agents will be rigorously tested in solution, applied to cultured breast cancer cells and ultimately used to examine P-gal activity in vivo in transfected breast tumors in mice and rats. SUBJECT TERMS NUMBER OF PAGESGene therapy, fluorine NMR, P-galactosidase, pH 127 IntroductionGene therapy holds great promise for treatment of breast cancer (1, 2). In particular, clinical trials are underway to apply therapeutic genes related to pro-drug activation or modulation of the activity of oncogenes by blocking promoter sites. However, there are major problems in terms of assessing the delivery to target tissue, assessing the uniformity (versus heterogeneity) of biodistribution and determining whether the genes are expressed. We propose to design, evaluate and apply a novel approach to gene activity detection-specifically, using fluorinated substrates of P3-galactosidase to reveal gene activity. Our prototype molecule PFONPG (para-fluoro-ortho-nitro-phenyl [3-D-galactopyranoside) is a direct analog of the traditional "yellow' biochemical indicator ONPG (ortho-nitro-phenyl 13-D-galactopyranoside).This shows useful MR characteristics, sensitivity to enzyme activity ...

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Fluorine-19 MRS: General Overview and Anaesthesia

Menon

2007

Encyclopedia of Magnetic Resonance

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In vivo 19F-NMR study of halothane distribution in brain

Cited by 31 publications

References 16 publications

In vivo fluorine‐19 magnetic resonance spectroscopy of cerebral halothane in postoperative patients: Preliminary results

In vivo fluorine‐19 magnetic resonance spectroscopy of cerebral halothane in postoperative patients: Preliminary results

Breast Cancer Gene Therapy: Development of Novel Non-Invasive Magnetic Resonance Assay to Optimize Efficacy

Fluorine-19 MRS: General Overview and Anaesthesia

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