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B A Bailey

Publications and source records attributed to B A Bailey.

14 recordsLinked to original sources
PubMed1994

Induction of ethylene biosynthesis in Nicotiana tabacum by a Trichoderma viride xylanase is correlated to the accumulation of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase transcripts.

Xylanase (EIX) from the fungus Trichoderma viride elicits ethylene biosynthesis in leaf tissues of Nicotiana tabacum cv Xanthi but not in cv Hicks. The increase in ethylene biosynthesis is accompanied by an accumulation of 1-aminocyclopropane-1-carboxylic acid (ACC), an increase in extractable ACC synthase activity, and increases in ACC synthase and ACC oxidase transcripts. Priming of increases in ACC synthase and ACC oxidase transcripts. Priming of leaves with ethylene (120 microL/L, 14 h) sensitizes the tissue, resulting in an enhanced response to EIX and increases in both the in vivo ACC oxidase activity and ACC oxidase transcript level. EIX and ethylene independently induce ACC oxidase. Inhibition of ethylene biosynthesis by aminoethoxyvinylglycine is not accompanied by a reduction in ACC oxidase transcript level, indicating that ethylene biosynthesis is not required. In contrast to the differential induction of ethylene biosynthesis by EIX in Xanthi versus Hicks cultivars, both cultivars respond to a chemical stress (induced by CuSO4) by enhancing ethylene production. This induction is accompanied by an increase in ACC synthase transcript but not in that of ACC oxidase.

Amino Acid Oxidoreductases↗
PubMed1992

Calcium transients in feline left ventricular myocytes with hypertrophy induced by slow progressive pressure overload.

A model of chronic, progressive pressure overload of the left ventricle was characterized in the cat. The aortas of young cats (10 weeks) were partially constricted with a 2.8 mm ID band, and the cats were allowed to grow to adulthood (8-13 months). This procedure resulted in severe cardiac hypertrophy as indicated by heart wt/body wt (g/kg) of 3.3 +/- 0.2 in controls (C) vs. 8.2 +/- 0.6 in left ventricular hypertrophy (LVH). The degree of aortic constriction (measured as the peak gradient across the root of the aorta) was significantly elevated in LVH 76 +/- 14 vs. -3.2 +/- 6 mmHg (C). Left ventricular systolic pressure was significantly elevated in LVH (162 +/- 18 vs. 96 +/- 7 mmHg in C). Cardiac index was significantly reduced in LVH 100 +/- 17 vs. 149 +/- 17 ml/min/kg in C, suggesting that the animals may have been progressing from a state of compensated hypertrophy to a decompensated state. The mechanical and contractile properties of isolated myocytes were also studied. LVH myocytes had significantly reduced magnitudes of shortening (6.2 +/- 0.4 vs. 7.8 +/- 0.12 %DCL), rates of shortening (0.28 +/- 0.03 vs. 0.45 +/- 0.05 %DCL/s), rates of relengthening (0.24 +/- 0.03 vs. 0.40 +/- 0.05 %DCL/s) and prolonged duration of twitch (0.67 +/- 0.04 vs. 0.55 +/- 0.03 s) compared to controls. Ca2+ transients were measured using indo-1. LVH myocytes had significantly depressed peak Ca2+ (I410/I480 2.31 +/- 0.07 vs. 2.53 +/- 0.08 in C) and significantly prolonged transient durations (0.74 +/- 0.03 vs. 0.59 +/- 0.02 s).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Correlating students' undergraduate science GPAs, their MCAT scores, and the academic caliber of their undergraduate colleges with their first-year academic performances across five classes at Dartmouth Medical School.

Reviewing the predictive validity of admission criteria to improve the selection process is important to a school in maintaining quality in the entering class. For this reason, the authors studied how the academic criteria used to select the 420 students who entered Dartmouth Medical School from 1982 to 1986 compared with the students' first-year academic performances. The criteria used were Medical College Admission Test scores, undergraduate science grade-point averages, and college selectivity (i.e., the academic caliber of the students' undergraduate colleges). Results showed that a combination of these criteria were useful in identifying the students who were successful in their first year. The authors suggest that their findings also demonstrate the ability to an admission committee to subjectively weigh these academic criteria with consistent results in student performance.

College Admission Test↗
PubMed1990

Effect of experience with nontraditional workers on psychological and social dimensions of occupational sex-role stereotyping by elementary school children.

AngloAmerican and Hispanic boys and girls ages 6 to 11 yr. (N = 219) were exposed to nontraditional workers within their elementary school classrooms. They rated 30 occupations as appropriate for men, women, or both men and women, on a pre- and posttest for a social dimension score (attribution of occupational sex-role stereotypes to others). Pre- and posttest fixed-choice selection of individual career aspirations indicated a psychological dimension score (individual job preference). Traditionality was measured from the child's point of view, not an adult concensus. Analysis shows: (a) When students are exposed to nontraditional role models their attitudes become less sex-typed on the social but not on the psychological dimension. (b) Sex and age affected career choices. (c) Historical-cultural (i.e., women's movement) events appear to have affected the children's attitudes on the social dimension.

Career Choice↗
PubMed1987

A behavioural and neurochemical analysis of chronic and selective monoamine oxidase inhibition.

The effects of clorgyline were compared with the effects of (-)-deprenyl using measures of rewarding hypothalamic self-stimulation, regional monoamine metabolism and monoamine oxidase activity. Male Wistar rats trained to self-stimulate at half-maximal rates with unilateral bipolar lateral hypothalamic electrodes on a continuous reinforcement schedule were implanted subcutaneously with osmotic minipumps which delivered 1 mg X kg-1 drug per day or vehicle for 13 days. A response rate/stimulation frequency (reward summation) function was determined the day before minipump implantation and on days 5 and 13 of drug administration. Only clorgyline induced a shift to the left in the reward summation function at 5 and 13 days, indicating enhancement of reinforcement. Clonidine (50 micrograms X kg-1 IP) probe tests were run on days 2 and 10 to determine the sensitivity of alpha 2-noradrenaline receptors. Clorgyline induced an attenuation of the clonidine response on day 10 relative to day 2. The other groups exhibited no change in response to clonidine. Clorgyline also induced a progressive increase in self-stimulation rates; this effect was not observed with the other groups. The clorgyline effects were accompanied by an increase in regional brain levels of dopamine, noradrenaline and 5-hydroxytryptamine and a reduction of their acid metabolites. Clorgyline selectively inhibited type A monoamine oxidase, whereas (-)-deprenyl selectively inhibited type B monoamine oxidase.

Animals↗
PubMed1987

In vivo release of endogenous dopamine, 5-hydroxytryptamine and some of their metabolites from rat caudate nucleus by phenylethylamine.

The in vivo release of endogenous 3,4-dihydroxyphenylethylamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 3-methoxytyramine (3-MT), and of 5-hydroxytryptamine (5-HT) and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), has been measured in the caudate nucleus of the anesthetized rat. A push-pull cannula was implanted into the brain, and the tissue perfused with artificial CSF or artificial CSF containing 5 X 10(-4) M phenylethylamine. The perfusate was collected and analyzed for DA, 5-HT and their metabolites by high performance liquid chromatography with electrochemical detection (HPLC-ECD). DA was released by phenylethylamine at rates significantly greater than its basal rate. 3-MT and 5-HT were undetectable in perfusates collected under basal conditions, but could be detected readily during phenylethylamine stimulation. DOPAC, HVA and 5-HIAA concentrations were not significantly affected by phenylethylamine. The results suggest (1) that phenylethylamine may exert its behavioural effects through increased release of both DA and 5-HT, and (2) that in vivo measurements of the acid metabolites alone may not be indicative of the release of the amines.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1986

Choice of analog electronic low-pass filters in chromatography.

Butterworth low-pass filters, frequently used to improve signal-to-noise ratios in chromatographic instrumentation, are chosen for their frequency domain characteristics; their time domain response may introduce spurious peaks which are eliminated by use of the Bessel filter which provides improved chromatographic response.

Biogenic Amines↗
PubMed1986

New sensitive high-performance liquid chromatographic method for p-tyrosine aminotransferase assay.

A rapid, sensitive and specific procedure has been developed for the determination of p-tyrosine aminotransaminase activity. The assay is based on high-performance liquid chromatography (HPLC) separation and electrochemical detection of the pyruvate product, which has been derivatized with hydroxylamine to form a stable oxime. Using this method the product at the low pmol level can be measured. A comparison of the kinetic parameters of the rat liver tyrosine aminotransferase and rat brain non-specific aspartate aminotransferase towards p-tyrosine has been made.

Animals↗
PubMed1986

Stereospecific deuterium substitution at the alpha-carbon position of dopamine and its effect on oxidative deamination catalyzed by MAO-A and MAO-B from different tissues.

Stereospecific replacement of deuterium in the alpha-carbon side chain position of dopamine (DA) was achieved by decarboxylation of L-3,4-dihydroxyphenylalanine (L-dopa) using hog kidney aromatic aminoacid decarboxylase. The S[alpha-2H1]DA enantiomer was obtained by decarboxylation of L-[alpha-2H1]dopa in H2O, while the R[alpha-2H1]DA enantiomer was obtained by decarboxylation of unsubstituted L-dopa in 2H2O. An inverse solvent isotope effect of L-dopa decarboxylation was observed in 2H2O. The deaminated aldehyde products of the four DA analogues, i.e. undeuterated DA, [alpha, alpha-2H2] DA, R[alpha-2H1]DA and S[alpha-2H1]DA, have been analyzed by the gas chromatography-mass spectrometry (GC-MS) method. It is evident that monoamine oxidase (MAO) catalyzes the stereochemical removal of only R-deuterium and that S-deuterium was maintained at the alpha-carbon atom of 3,4-dihydroxyphenylacetaldehyde. The steady-state kinetics of the oxidative deamination of undeuterated, [alpha, alpha-2H2], R[alpha-2H1], and S[alpha-2H1] dopamine were assessed by determination of the aldehyde products directly by high performance liquid chromatography (HPLC) using electrochemical detection (ECD). MAO-A from rat liver mitochondria (deprenyl-treated) and from human placenta, as well as MAO-B from rat liver (clorgyline-treated) and from human platelet were used in this study. The apparent isotope effects, i.e. (V/K)H/(V/K)D ratios of [alpha, alpha-2H2]DA and R[alpha-2H1]DA, were quite similar (2.34 and 3.13) with respect to both MAO-A and MAO-B. S[alpha-2H1]DA exhibited a slight secondary isotope effect. Formula: see text.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1986

High-performance liquid chromatography of aldehydes and acids formed in monoamine oxidase-catalyzed reactions.

A rapid, sensitive, and specific method for the determination of monoamine oxidase (MAO) activities toward different substrates is described. The assay is based on high-performance liquid chromatographic (HPLC) separation and electrochemical detection of the aldehyde or acid products. The aldehyde metabolic intermediates were observed to be quite stable in 0.1 N perchloric acid containing antioxidant and EDTA, and therefore can be used to measure the MAO activity of washed mitochondrial membrane and partially purified or purified MAO. Incomplete conversion of aldehyde to acid was observed when the amine substrates were incubated with the crude enzyme preparations. These aldehydes can be converted to corresponding acids by addition of yeast aldehyde dehydrogenase and beta-NAD and the acid can also be measured by HPLC-electrochemical detection. A deuterium isotope effect in the oxidation of p-[alpha,alpha-2H2]tyramine and [alpha,alpha-2H2]serotonin has been demonstrated by this method.

Acids↗
PubMed1983

Rapid estimation of catecholamines, octopamine and 5-hydroxytryptamine in biological tissues using high-performance liquid chromatography with coulometric detection.

A rapid, convenient procedure is described for the simultaneous determination of catecholamines, monohydroxyphenolamines and 5-hydroxytryptamine in biological tissues. The procedure involves homogenization of tissue in perchloric acid, addition of heparin and centrifugation followed by direct injection of the supernatant onto a C18 reversed-phase high-performance liquid chromatographic column. The mobile phase employed sodium dodecyl sulfate as ion pair reagent with 20% acetonitrile and 10-12% methanol as organic modifier. Eluted fractions were detected electrochemically using dual coulometric electrodes operated in screen mode. The procedure has been applied to the analysis of norepinephrine, epinephrine, dopamine, octopamine, tyramine, 5-hydroxytryptamine and tryptophan in a variety of tissues including mammalian heart and brain and insect nerve cord.

Animals↗
PubMed1978

Line copy presentation slides with Kodalith.

Line copy presentation slides with white letters on a blue background can be produced with a two-step process. The slides are more permanent than diazo slides, and the process is faster and less expensive.

Ophthalmology↗
PubMed1975

The effect of an H2-receptor antagonist on food-stimulated acid secretion, serum gastrin, and gastric emptying in patients with duodenal ulcers. Comparison with an anticholinergic drug.

The purpose of the present series of experiments was to measure and compare the effects of an anticholinergic drug (isopropamide) and an antagonist of the histamine H2 receptor (metiamide) on food-stimulated acid secretion. Patients with duodenal ulcers were stimulated by a steak meal, and acid secretion was measured by in vivo intragastric titration. The largest dose of isopropamide that can be taken clinically without producing intolerable side effects (maximum tolerated dose) suppressed food-stimulated acid secretion by 35%. By contrast, metiamide in a 400-mg dose produced no side effects and almost completely abolished food-stimulated acid secretion. A dose-response curve revealed that a 50-mg dose of metiamide was required to suppress food-stimulated acid secretion by 50%. Further studies showed that metiamide and isopropamide are additive in suppressing food-stimulated acid secretion, and that metiamide has no effect on serum gastrin concentration or on gastric emptying.

Adult↗