Furn Knapp - Academia.edu (original) (raw)

Papers by Furn Knapp

Research paper thumbnail of Radiohalogenated thienylethylamine derivatives for evaluating local cerebral blood flow

International Journal of Radiation Applications and Instrumentation. Part B. Nuclear Medicine and Biology, 1990

Research paper thumbnail of The mass spectral fragmentation of phenyl ?-dialkoxyethyl tellurides

J Mass Spectrometry, 1979

Research paper thumbnail of New azomycin acyclonucleoside. Synthesis and biodistribution of radiohalogenated analogues in tumor-bearing mice

J Heterocycl Chem, Oct 1, 1993

Abstract The design, synthesis and biological activities of several acyclonucleoside analogues re... more Abstract The design, synthesis and biological activities of several acyclonucleoside analogues related to misoni-dazole are described. The hydroxy-5, bromo-6, iodo-7, and fluoro-8 derivatives of ethoxymethylazomycin and iodopropenyloxymethylazomycin (12) ...

Research paper thumbnail of An unusual mass spectral fragmentation of C-4 alkylated cholesterols

Journal of the Chemical Society, Chemical Communications, 1974

Research paper thumbnail of Radiolabeled dimethyl branched long chain fatty acid for heart imaging

International Journal of Radiation Applications and Instrumentation. Part B. Nuclear Medicine and Biology, 1989

ABSTRACT

Research paper thumbnail of Chemical synthesis, spectral properties, and chromatography of 4α-methyl and 4β-methyl isomers of (24R)-24-ethyl-5α-cholestan-3β-ol and (24S)-24-ethyl-cholesta-5,22-dien-3β-ol

Steroids, 1975

Described herein are chemical syntheses of the following compounds: 4-methyl-(24S)-24-ethyl-chole... more Described herein are chemical syntheses of the following compounds: 4-methyl-(24S)-24-ethyl-cholesta-4,22-dien-3-one, 4,4-dimethyl-(24S)-24-ethyl-cholesta-5,22-dien-3-one, 4beta-methyl-(24R)-24-ethyl-5alpha-cholestan-3beta-ol, 4alpha-methyl-(24R)-24-ethyl-5alpha-cholestan-3beta-ol, 4alpha-methyl-(24S)-24-ethyl-5alpha-cholest-22-en-3beta-ol, 4-methyl-6beta-bromo-(24S)-24-ethyl-cholesta-4,22-dien-3-one, 4alpha-methyl-(24S)-24-ethyl-cholesta-5,22-dien-3beta-ol, 4alpha,5alpha-epoxy-(24S)-24-ethyl-cholesta-4,22-dien-3beta-yl acetate, 4beta-methyl-(24S)-24-ethyl-cholest-22-en-3beta,5alpha-diol, 4beta-methyl-5alpha-hydroxy-(24S)-24-ethyl-cholest-22-en-3beta-yl acetate, 4beta-methyl-(24S)-24-ethyl-cholesta-5,22-dien-3beta-yl acetate and 4beta-methyl-(24S)-24-ethyl-cholesta-5,22-dien-3beta-ol. Chromatographic, nuclear magnetic resonance, and mass spectral data are presented for the compounds under consideration.

Research paper thumbnail of Concerning the role of 4.beta.-methyl sterols in cholesterol biosynthesis

Journal of the American Chemical Society, 1975

Research paper thumbnail of Mass spectral fragmentation of 5α-hydroxysteroids

Chemistry and Physics of Lipids, 1976

Research paper thumbnail of Mass spectrometry of sterols. Electron ionization induced fragmentation of C-4-alkylated cholesterols

Chemistry and Physics of Lipids, 1976

The electron impact ionization of C-4-alkylated cholest-5-en-3beta-hydroxysterols has been invest... more The electron impact ionization of C-4-alkylated cholest-5-en-3beta-hydroxysterols has been investigated. The mass spectra of the C-4-alkylated cholesterols contain a number of ions in the high mass region for which analogous ions are not found in the spectrum of cholesterol. Detailed studies of the composition and origin of these ions have been made by high resolution mass spectrometry and analysis of metastable ions. In addition, a large number of isotopically (deuterium and 18O) substituted C-4-alkylated analogues have been prepared to assist in the interpretation of the spectra. The combined results indicate the occurrence of a number of very complex and unusual electron ionization induced fragmentations. Most notable of the findings reported herein concerns the demonstration of the formation of an ion involving loss of the elements of ring A with an intramolecular shift of the oxygen and hydrogen atoms of the hydroxyl function to the charge-retaining species.

Research paper thumbnail of Indirect Production of No Carrier Added (NCA) <sup>177</sup>Lu from Irradiation of Enriched <sup>176</sup>Yb: Options for Ytterbium/Lutetium Separation

Current Radiopharmaceuticals, 2015

Research paper thumbnail of Production of 177Lu for Targeted Radionuclide Therapy: Available Options

Nuclear Medicine and Molecular Imaging, 2015

This review provides a comprehensive summary of the production of (177)Lu to meet expected future... more This review provides a comprehensive summary of the production of (177)Lu to meet expected future research and clinical demands. Availability of options represents the cornerstone for sustainable growth for the routine production of adequate activity levels of (177)Lu having the required quality for preparation of a variety of (177)Lu-labeled radiopharmaceuticals. The tremendous prospects associated with production of (177)Lu for use in targeted radionuclide therapy (TRT) dictate that a holistic consideration should evaluate all governing factors that determine its success. While both &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;direct&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;indirect&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; reactor production routes offer the possibility for sustainable (177)Lu availability, there are several issues and challenges that must be considered to realize the full potential of these production strategies. This article presents a mini review on the latest developments, current status, key challenges and possibilities for the near future. A broad understanding and discussion of the issues associated with (177)Lu production and processing approaches would not only ensure sustained growth and future expansion for the availability and use of (177)Lu-labeled radiopharmaceuticals, but also help future developments.

Research paper thumbnail of Evolving Important Role of Lutetium-177 for Therapeutic Nuclear Medicine

Current radiopharmaceuticals, Jan 12, 2015

Lutetium-177 (177Lu) is a late entrant into the nuclear medicine therapy arena but is expected to... more Lutetium-177 (177Lu) is a late entrant into the nuclear medicine therapy arena but is expected to be poised to become one of the most widely used therapeutic radionuclides. This paper analyses the reason for the increasing preference of 177Lu as a therapeutic radionuclide. While the radionuclidic properties favor its use for several therapeutic applications, the potential for large scale production of 177Lu is also an important aspect for its acceptability as a therapeutic radionuclide. This introductory discussion also summarizes some developing clinical uses and suggested future directions for applications of 177Lu.

Research paper thumbnail of Rhenium-188 - A Generator-Derived Radioisotope for Cancer Therapy

Cancer Biotherapy & Radiopharmaceuticals, 1998

Research paper thumbnail of Phytosterol biosynthesis in banana peel. Initial removal of the 4α-methyl group of 24-methylenecycloartanol during its conversion into cycloeucalenol in Musa sapientum

Research paper thumbnail of Liquid Crystalline Properties of Ergosteryl Fatty Acid Esters

Molecular Crystals and Liquid Crystals, 1970

Thirteen fatty acid esters of ergosterol (24α-methyl-5, 7, 22-cholestatrien-3β-ol) have been prep... more Thirteen fatty acid esters of ergosterol (24α-methyl-5, 7, 22-cholestatrien-3β-ol) have been prepared and their liquid crystalline properties studied with the polarizing microscope. Ergosteryl acetate is not mesomorphic. Saturated even-chain esters from the butyrate to the laurate form enaniotropic smectic transitions. The myristate and palmitate form monotropic transitions, the smetic mesophases being formed only upon cooling the isotropic liquid. The stearate

Research paper thumbnail of Cycloartenyl Palmitate: A Naturally Occurring Ester that Forms a Cholesteric Mesophase

Research paper thumbnail of Structural Studies of the Cholesteric Mesophase

Liquid Crystals and Ordered Fluids, 1970

Research paper thumbnail of The synthesis of123m Te-labeled 17� -hydroxy-2-tellura-A-nor-5a-androstane

J Label Compound Radiopharm, 1980

Research paper thumbnail of Tungsten-188/carrier-free rhenium-188 perrhenic acid generator system

ABSTRACT A generator system for providing a carrier-free radioisotope in the form of an acid comp... more ABSTRACT A generator system for providing a carrier-free radioisotope in the form of an acid comprises a chromatography column in tandem fluid connection with an ion exchange column, the chromatography column containing a charge of a radioactive parent isotope. The chromatography column, charged with a parent isotope, is eluted with an alkali metal salt solution to generate the radioisotope in the form of an intermediate solution, which is passed through the ion-exchange column to convert the radioisotope to a carrier-free acid form.

Research paper thumbnail of Technetium-99m generator system

ABSTRACT A ⁹⁹Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composit... more ABSTRACT A ⁹⁹Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composition containing ⁹⁹Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating {sup 99m}Tc eluted from the sorbent column. A method of preparing a concentrated solution of {sup 99m}Tc includes the general steps of: (a) providing a sorbent column loaded with a composition containing ⁹⁹Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; (b) eluting the sorbent column with a salt solution to elute {sup 99m}Tc from the sorbent and to trap and concentrate the eluted {sup 99m}Tc on the ion-exchange column; and (c) eluting the concentrated {sup 99m}Tc from the ion-exchange column with a solution comprising a reductive complexing agent. 1 fig.

Research paper thumbnail of Radiohalogenated thienylethylamine derivatives for evaluating local cerebral blood flow

International Journal of Radiation Applications and Instrumentation. Part B. Nuclear Medicine and Biology, 1990

Research paper thumbnail of The mass spectral fragmentation of phenyl ?-dialkoxyethyl tellurides

J Mass Spectrometry, 1979

Research paper thumbnail of New azomycin acyclonucleoside. Synthesis and biodistribution of radiohalogenated analogues in tumor-bearing mice

J Heterocycl Chem, Oct 1, 1993

Abstract The design, synthesis and biological activities of several acyclonucleoside analogues re... more Abstract The design, synthesis and biological activities of several acyclonucleoside analogues related to misoni-dazole are described. The hydroxy-5, bromo-6, iodo-7, and fluoro-8 derivatives of ethoxymethylazomycin and iodopropenyloxymethylazomycin (12) ...

Research paper thumbnail of An unusual mass spectral fragmentation of C-4 alkylated cholesterols

Journal of the Chemical Society, Chemical Communications, 1974

Research paper thumbnail of Radiolabeled dimethyl branched long chain fatty acid for heart imaging

International Journal of Radiation Applications and Instrumentation. Part B. Nuclear Medicine and Biology, 1989

ABSTRACT

Research paper thumbnail of Chemical synthesis, spectral properties, and chromatography of 4α-methyl and 4β-methyl isomers of (24R)-24-ethyl-5α-cholestan-3β-ol and (24S)-24-ethyl-cholesta-5,22-dien-3β-ol

Steroids, 1975

Described herein are chemical syntheses of the following compounds: 4-methyl-(24S)-24-ethyl-chole... more Described herein are chemical syntheses of the following compounds: 4-methyl-(24S)-24-ethyl-cholesta-4,22-dien-3-one, 4,4-dimethyl-(24S)-24-ethyl-cholesta-5,22-dien-3-one, 4beta-methyl-(24R)-24-ethyl-5alpha-cholestan-3beta-ol, 4alpha-methyl-(24R)-24-ethyl-5alpha-cholestan-3beta-ol, 4alpha-methyl-(24S)-24-ethyl-5alpha-cholest-22-en-3beta-ol, 4-methyl-6beta-bromo-(24S)-24-ethyl-cholesta-4,22-dien-3-one, 4alpha-methyl-(24S)-24-ethyl-cholesta-5,22-dien-3beta-ol, 4alpha,5alpha-epoxy-(24S)-24-ethyl-cholesta-4,22-dien-3beta-yl acetate, 4beta-methyl-(24S)-24-ethyl-cholest-22-en-3beta,5alpha-diol, 4beta-methyl-5alpha-hydroxy-(24S)-24-ethyl-cholest-22-en-3beta-yl acetate, 4beta-methyl-(24S)-24-ethyl-cholesta-5,22-dien-3beta-yl acetate and 4beta-methyl-(24S)-24-ethyl-cholesta-5,22-dien-3beta-ol. Chromatographic, nuclear magnetic resonance, and mass spectral data are presented for the compounds under consideration.

Research paper thumbnail of Concerning the role of 4.beta.-methyl sterols in cholesterol biosynthesis

Journal of the American Chemical Society, 1975

Research paper thumbnail of Mass spectral fragmentation of 5α-hydroxysteroids

Chemistry and Physics of Lipids, 1976

Research paper thumbnail of Mass spectrometry of sterols. Electron ionization induced fragmentation of C-4-alkylated cholesterols

Chemistry and Physics of Lipids, 1976

The electron impact ionization of C-4-alkylated cholest-5-en-3beta-hydroxysterols has been invest... more The electron impact ionization of C-4-alkylated cholest-5-en-3beta-hydroxysterols has been investigated. The mass spectra of the C-4-alkylated cholesterols contain a number of ions in the high mass region for which analogous ions are not found in the spectrum of cholesterol. Detailed studies of the composition and origin of these ions have been made by high resolution mass spectrometry and analysis of metastable ions. In addition, a large number of isotopically (deuterium and 18O) substituted C-4-alkylated analogues have been prepared to assist in the interpretation of the spectra. The combined results indicate the occurrence of a number of very complex and unusual electron ionization induced fragmentations. Most notable of the findings reported herein concerns the demonstration of the formation of an ion involving loss of the elements of ring A with an intramolecular shift of the oxygen and hydrogen atoms of the hydroxyl function to the charge-retaining species.

Research paper thumbnail of Indirect Production of No Carrier Added (NCA) <sup>177</sup>Lu from Irradiation of Enriched <sup>176</sup>Yb: Options for Ytterbium/Lutetium Separation

Current Radiopharmaceuticals, 2015

Research paper thumbnail of Production of 177Lu for Targeted Radionuclide Therapy: Available Options

Nuclear Medicine and Molecular Imaging, 2015

This review provides a comprehensive summary of the production of (177)Lu to meet expected future... more This review provides a comprehensive summary of the production of (177)Lu to meet expected future research and clinical demands. Availability of options represents the cornerstone for sustainable growth for the routine production of adequate activity levels of (177)Lu having the required quality for preparation of a variety of (177)Lu-labeled radiopharmaceuticals. The tremendous prospects associated with production of (177)Lu for use in targeted radionuclide therapy (TRT) dictate that a holistic consideration should evaluate all governing factors that determine its success. While both &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;direct&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;indirect&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; reactor production routes offer the possibility for sustainable (177)Lu availability, there are several issues and challenges that must be considered to realize the full potential of these production strategies. This article presents a mini review on the latest developments, current status, key challenges and possibilities for the near future. A broad understanding and discussion of the issues associated with (177)Lu production and processing approaches would not only ensure sustained growth and future expansion for the availability and use of (177)Lu-labeled radiopharmaceuticals, but also help future developments.

Research paper thumbnail of Evolving Important Role of Lutetium-177 for Therapeutic Nuclear Medicine

Current radiopharmaceuticals, Jan 12, 2015

Lutetium-177 (177Lu) is a late entrant into the nuclear medicine therapy arena but is expected to... more Lutetium-177 (177Lu) is a late entrant into the nuclear medicine therapy arena but is expected to be poised to become one of the most widely used therapeutic radionuclides. This paper analyses the reason for the increasing preference of 177Lu as a therapeutic radionuclide. While the radionuclidic properties favor its use for several therapeutic applications, the potential for large scale production of 177Lu is also an important aspect for its acceptability as a therapeutic radionuclide. This introductory discussion also summarizes some developing clinical uses and suggested future directions for applications of 177Lu.

Research paper thumbnail of Rhenium-188 - A Generator-Derived Radioisotope for Cancer Therapy

Cancer Biotherapy & Radiopharmaceuticals, 1998

Research paper thumbnail of Phytosterol biosynthesis in banana peel. Initial removal of the 4α-methyl group of 24-methylenecycloartanol during its conversion into cycloeucalenol in Musa sapientum

Research paper thumbnail of Liquid Crystalline Properties of Ergosteryl Fatty Acid Esters

Molecular Crystals and Liquid Crystals, 1970

Thirteen fatty acid esters of ergosterol (24α-methyl-5, 7, 22-cholestatrien-3β-ol) have been prep... more Thirteen fatty acid esters of ergosterol (24α-methyl-5, 7, 22-cholestatrien-3β-ol) have been prepared and their liquid crystalline properties studied with the polarizing microscope. Ergosteryl acetate is not mesomorphic. Saturated even-chain esters from the butyrate to the laurate form enaniotropic smectic transitions. The myristate and palmitate form monotropic transitions, the smetic mesophases being formed only upon cooling the isotropic liquid. The stearate

Research paper thumbnail of Cycloartenyl Palmitate: A Naturally Occurring Ester that Forms a Cholesteric Mesophase

Research paper thumbnail of Structural Studies of the Cholesteric Mesophase

Liquid Crystals and Ordered Fluids, 1970

Research paper thumbnail of The synthesis of123m Te-labeled 17� -hydroxy-2-tellura-A-nor-5a-androstane

J Label Compound Radiopharm, 1980

Research paper thumbnail of Tungsten-188/carrier-free rhenium-188 perrhenic acid generator system

ABSTRACT A generator system for providing a carrier-free radioisotope in the form of an acid comp... more ABSTRACT A generator system for providing a carrier-free radioisotope in the form of an acid comprises a chromatography column in tandem fluid connection with an ion exchange column, the chromatography column containing a charge of a radioactive parent isotope. The chromatography column, charged with a parent isotope, is eluted with an alkali metal salt solution to generate the radioisotope in the form of an intermediate solution, which is passed through the ion-exchange column to convert the radioisotope to a carrier-free acid form.

Research paper thumbnail of Technetium-99m generator system

ABSTRACT A ⁹⁹Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composit... more ABSTRACT A ⁹⁹Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composition containing ⁹⁹Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating {sup 99m}Tc eluted from the sorbent column. A method of preparing a concentrated solution of {sup 99m}Tc includes the general steps of: (a) providing a sorbent column loaded with a composition containing ⁹⁹Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; (b) eluting the sorbent column with a salt solution to elute {sup 99m}Tc from the sorbent and to trap and concentrate the eluted {sup 99m}Tc on the ion-exchange column; and (c) eluting the concentrated {sup 99m}Tc from the ion-exchange column with a solution comprising a reductive complexing agent. 1 fig.