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Biomedical subjects

S Farrokhzad

Publications and source records attributed to S Farrokhzad.

7 recordsLinked to original sources
PubMed1985

Pharmacokinetics of 11C-BCNU in experimental brain tumor.

Wistar rats implanted intracerebrally with AA ascites tumor were injected seven or eight days later with 11C-labelled BCNU. Radioactive compounds in samples of plasma, tumor, and contralateral brain were identified after injection at intervals by doing chloroform extraction and thin layer radiochromatography. At 60 min after injection radioactivity levels were 56% higher in the tumor than in contralateral brain. This increase was due mainly to 2-chlorethyl isocyanate, which binds to amino groups and/or nucleic acid. The results demonstrated both a higher concentration and a faster decomposition of BCNU in the tumor.

Animals↗
PubMed1985

New synthesis of fluorine-18-labeled 6-fluoro-L-dopa by cleaving the carbon-silicon bond with fluorine.

A new synthesis of 3,4-dihydroxy-6-[18F]fluoro-L-phenylalanine using 6-trimethylsilyl-3,4-dimethoxy-L-dopa-ethylester as a fluorination substrate is described. The silane is prepared from the corresponding bromo compound by reacting the latter with magnesium and trimethylsilyl chloride. Reaction of the silane with [18F]F2 (0.5% F2 in neon) in a mixture of freon-11/CCl4 (1:1) kept in a dry ice bath, subsequent hydrolysis with concentrated HBr in a bath at 140 degrees C, and simple chromatographic purification yielded 18F-labeled 6-fluoro-L-dopa. A radiochemical yield of about 8% was achieved at the end of the 1-hr synthesis. The specific activity at the end of the synthesis was about 680 mCi/mmol after a 30-min irradiation.

Chemical Phenomena↗
PubMed1984

Pharmacokinetics of positron-labeled 1,3-bis(2-chloroethyl)nitrosourea in human brain tumors using positron emission tomography.

The nitrosoureas are widely used in the chemotherapy of brain tumors, two of the most common being 1,3-bis(2-chloroethyl)nitrosourea and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea. However, we do not understand how these compounds work, nor do we know which part of the molecule has antitumor activity. In six patients with brain tumor, we measured the kinetic behavior of positron-labeled 1,3-bis(2-chloroethyl)nitrosourea in both the tumor and the normal brain with the aid of positron emission tomography; we also analyzed the distribution of radioactivity in plasma. We found the clearance of total radioactivity from the tumor to be significantly slower than from the contralateral brain and plasma, indicating a different rate of 1,3-bis(2-chloroethyl)nitrosourea decomposition in the tumor than in normal brain.

Brain Neoplasms↗