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J C Cook

Publications and source records attributed to J C Cook.

At least 37 records · Page 2Linked to original sources
PubMed1984

Structures of two cockroach neuropeptides assigned by fast atom bombardment mass spectrometry.

Amino acid sequences have been assigned to two cockroach neuropeptides (greater than Glu-Val-Asn-Phe-Ser-Pro-Asn-Trp-NH2, M I, and greater than Glu-Leu-Thr-Phe-Thr-Pro-Asn-Trp-NH2, M II) by application of fast atom bombardment mass spectrometry, including high resolution and linked scan (metastable) studies. The peptides show considerable homology with two other invertebrate neuropeptides, adipokinetic hormone (AKH, from a locust) and red pigment concentrating hormone (RPCH, from a prawn), whose fast atom bombardment spectra were also studied. M I and M II are thus members of a family of structurally-related invertebrate neuropeptides.

Amino Acid Sequence↗
PubMed1983

Induction of cytochrome P-450 by methylenedioxyphenyl compounds: importance of the methylene carbon.

Induction of hepatic microsomal cytochrome P-450 in Dub:ICR male mice treated with phenobarbital, 3-methylcholanthrene, safrole, isosafrole, 5-tert.-butyl-1,3-benzodioxole (BBD), 2-methyl-5-tert.-butyl-1,3-benzodioxole (MBBD), and 2,2-dimethyl-5-tert.-butyl-1,3-benzodiozole (DBBD) was evaluated by measuring the cytochrome P-450 content, Type II:Type 1 binding ratio, ethylisocyanide pH equilibrium point, biphenyl 2- and 4-hydroxylase, ethylmorphine N-demethylase, ethoxyresorufin O-deethylase, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Safrole and isosafrole treatment of mice produced a phenobarbital-type induction. BBD, but not MBBD and DBBD, induced cytochrome P-450 and formed a Type III metabolite-cytochrome P-450 complex, in vitro and in vivo. SDS-PAGE revealed that DBBD does induce proteins other than cytochrome P-450. These data suggest that the methylene carbon plays an important role in cytochrome P-450 induction.

Animals↗
PubMed1983

Factors associated with successful vaginal delivery after cesarean section.

To assess obstetric parameters that would predict successful vaginal delivery in patients with prior cesarean sections, the perinatal records of 579 such patients were reviewed. Sixty-six percent of the patients (385) had elective repeat cesarean sections. Of the 194 patients who attempted vaginal delivery, three-fourths (148) had success. Perinatal parameters that were statistically significant indicators of success included: nonrecurrent indication for cesarean section, vaginal delivery either prior or subsequent to cesarean section, duration of labor less than 24 hours prior to cesarean section, infant's birth weight less than 4,000 gm and cervical dilatation greater than 4 cm on admission for attempted vaginal delivery.

Birth Weight↗
PubMed1981

Pyochelin: novel structure of an iron-chelating growth promoter for Pseudomonas aeruginosa.

Pyochelin, an endogenous growth promoter that solubilizes ferric iron, has been isolated from Pseudomonas aeruginosa, including clinical strains. The structure of pyochelin has been assigned as 2-(2-o-hydroxyphenyl-2-thiazolin-4-yl)-3-methylthiazolidine-4-carboxylic acid and is of a different type from those previously assigned to siderophores (siderochromes) from bacteria. The assignment rests on 1H and 13C NMR data, high-resolution (including field desorption) mass spectrometry, and spectroscopic properties of synthetic model compounds. Pyochelin is presumed to be biosynthesized from salicylic acid and two moles of cysteine.

Growth Substances↗
PubMed1980

Field desorption mass spectrometry in structural studies of polyene macrolide antibiotics: isolation and early identification of a pentaene macrolide antibiotic.

Isolation of a pentaene macrolide antibiotic (NSC-277813) from Streptomyces griseus (FCRC-21) fermentation broth is described. Using field desorption mass spectrometry and high resolution field desorption mass spectrometry on the intact and derivatized antibiotic and degradation products, the antibiotic was identified as fungichromin. The application of field desorption mass spectrometry in the identification of polyene antibiotics is discussed.

Antibiotics, Antineoplastic↗
PubMed1977

Phosphazenes: high molecular weight reference compounds for field desorption mass spectrometry.

Because of poor field ionization sensitivity or an insufficient number of peaks, conventional reference materials are inadequate for field desorption mass spectrometry. Hexakis (multifluoroalkoxy)cyclotriphosphazenes satisfy a growing need for high molecular weight reference compounds amenable to either electron impact or field ionization. In comparison with tris(perfluoroalkyl)-s-triazine standards, the substituted phosphazenes offer greater volatility, easier synthesis and better mass spectral characteristics. Phosphazene mixtures, in particular, cover a broad mass range in either ionization mode, creating new measurement capabilities for ions at high masses.

Chromatography, Gas↗
PubMedDate not supplied

The induction of cytochrome P-450 by isosafrole and related methylenedioxyphenyl compounds.

Using sucrose gradients, the Ah receptor and a 3-4S binding peak were measured in hepatic cytosol from Dub: ICR, C57BL/6, and DBA/2 male mice. Isosafrole, piperonyl butoxide, and 5-t-butyl-1,3-benzodioxole were unable to displace 2,3,7,8-tetrachlorodibenzo-p-dioxin or 3-methylcholanthrene from either the Ah receptor or the 3-4S binding peak, in vitro. In in vivo experiments, treatment of C57BL/6 mice with 3-methylcholanthrene caused a 4-fold reduction in Ah receptor binding 2 h after i.p. injection; whereas, isosafrole caused a 2-fold enhancement of the Ah receptor after 24 h. This increase in the Ah receptor binding following isosafrole treatment may be due to induction. 3-Methylcholanthrene treatment of C57BL/6 mice also caused a 3-fold reduction in the 3-4S binding peak 2 h after i.p. injection; isosafrole treatment had little or no effect on the 3-4S peak in C57BL/6 or DBA/2 mice. Both in vivo and in vitro data appear to demonstrate that there is no direct role for the Ah receptor or the 3-4S protein in the regulation of cytochrome P-450 by methylenedioxyphenyl compounds. Using Sephadex G-100 chromatography, a cytosolic protein fraction was obtained from C57BL/6 and Dub:ICR mice which was previously implicated by others as a carrier in the metabolism of benzo[a]pyrene (B[a]P). This fraction was applied to sucrose gradients and sedimented in the 3-4S region. Hence it appears that the 3-4S binding peak may be the carrier described by these workers.

Animals↗