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J M de Haas

Publications and source records attributed to J M de Haas.

3 recordsLinked to original sources
PubMed1996

Improved extraction procedure for the assay of isosorbide-5-mononitrate in serum.

A procedure is described for the extraction of isosorbide-5-mononitrate from serum with diethyl ether-n-butyl acetate (15:1, v/v). After extraction, the diethyl ether is evaporated at room temperature and the nitrate remains dissolved in the relatively non-volatile n-butyl acetate phase. Glassware must be used throughout as the recovery of isosorbide-5-mononitrate is not reproducible when plastic tubes or plastic pipettes are used. The extraction recovery of isosorbide-5-mononitrate from serum is 67 +/- 7%, measured relative to external standards.

Chromatography, Gas↗
PubMed1991

Two potential Petunia hybrida mitochondrial DNA replication origins show structural and in vitro functional homology with the animal mitochondrial DNA heavy and light strand replication origins.

Four Petunia hybrida mitochondrial (mt) DNA fragments have been isolated, sequenced, localized on the physical map and analyzed for their ability to initiate specific DNA synthesis. When all four mtDNA fragments were tested as templates in an in vitro DNA synthesizing lysate system, developed from purified P. hybrida mitochondria, specific initiation of DNA synthesis could only be observed starting within two fragments, oriA and oriB. When DNA synthesis incubations were performed with DNA templates consisting of both the A and B origins in the same plasmid in complementary strands, DNA synthesis first initiates in the A-origin, proceeds in the direction of the B-origin after which replication is also initiated in the B-origin. Based on these observations, a replication model for the P. hybrida mitochondrial genome is presented.

Animals↗