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Biomedical subjects

H A Bates

Publications and source records attributed to H A Bates.

18 recordsLinked to original sources
PubMed1984

Structure and synthesis of histopine, a histidine derivative produced by crown gall tumors.

Histopine, an unusual amino acid derivative of histidine isolated from crown gall tumors of sunflowers (Helianthus annus) inoculated with Agrobacterium tumefaciens strain B6, was previously assigned the gross structure N-(1-carboxyethyl) histidine (2). A diastereomeric mixture containing histopine (2a and 2b) was readily prepared by reductive alkylation of (S)-histidine (1) with pyruvic acid and sodium cyanoborohydride. The individual diastereomers were prepared by reaction of (S)-histidine with (R)- and (S)-2-bromopropionic acid. (R)-N-(1-Carboxyethyl)-(S)-histidine (2a) supports the growth of A. tumefaciens whereas (S)-N-(1-carboxyethyl)-(S)-histidine (2b) is inactive. Therefore, we assign structure 2a to histopine.

Chromatography, High Pressure Liquid↗
PubMed1979

Arachidonic acid is responsible for the smooth muscle-contracting activity of G-acid.

G-acid, a smooth-muscle-contracting substance isolated from human blood plasma, was previously identified as 3-octadecenoic acid. Synthetic cis- and trans-3-octadecenoic acid, however, are biologically inactive. G-acid actually consists of a mixture of fatty acids, characteristic of animal tissues. The biological activity is caused by arachidonic acid, which contracts smooth muscle upon in situ conversion to prostaglandins.

Animals↗
PubMed1978

Increased incidence of positive tests for estrogen binding in mammary carcinoma specimens transported in liquid nitrogen.

Use of a liquid nitrogen container for convenient transport of frozen mammary carcinoma tissue for hormone-receptor assays is described. The container can be used in dry or wet mode and is appropriate for all types of transport, including air. Experience shows a significantly higher incidence of positive tests on specimens transported by this means than on specimens transported in dry ice.

Breast Neoplasms↗
PubMed1972

Cytoplasmic immunofluorescence of blood cells from myeloma, Hodgkin's disease an cultured cells from normal liver.

The immunofluorescent reaction of peripheral blood cells from 10 multiple myeloma, 10 Hodgkin's and 11 lymphosarcoma cases with antiviral (Rauscher) murine leukaemia (AMR) and antihuman stem cell leukaemia plasma (AHS) antisera was studied. Cells from 25 of these patients were reactive at least once with AMR and AHS or AHS alone. Absorption studies suggested that this cytoplasmic immunofluorescent reaction involved cellular isoantigens. Serial studies on multiple myeloma, Hodgkin's and lymphosarcoma cases with significant fluorescence, showed that the fluorescent cell count variation was correlated with the presence of active disease.

Absorption↗
PubMed1971

The effects of protamine on a murine leukemia virus.

THIS STUDY INDICATED THAT: (1) i.p. inoculation of protamine into (Rauscher) leukemic mice increased their X death time, (2) protamine was more toxic for leukemic than normal mice and (3) the in vitro reaction between Rauscher virus and protamine reduced its infectivity for mice.

Animals↗
PubMedDate not supplied

A direct method for assignment of absolute configurations in crown gall metabolites: the structure of nopaline.

The absolute configurations of the crown gall tumor metabolite nopaline (1a) have been determined by a direct degradative method. Oxidation of nopaline with KMnO4 afforded (S)-arginine and (R)-glutamic acid. Separation of these two amino acids was accomplished easily and simultaneously with determination of chirality by chromatography on a reverse-phase column eluted with chiral eluent. The present technique can easily determine absolute configurations on submilligram quantities. In contrast, an attempted determination of absolute configuration by synthesis from (S)-arginine and chiral 2-chloropentanedioic acid was unsuccessful.

Arginine↗