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J A Bailey

Publications and source records attributed to J A Bailey.

At least 37 records · Page 2Linked to original sources
PubMed1996

Flow-flash kinetics of O2 binding to cytochrome c oxidase at elevated [O2]: observations using high pressure stopped flow for gaseous reactants.

A high-pressure stopped-flow apparatus developed in our laboratories provides the capability to use dissolved gaseous reactants at elevated concentrations in solution (in equilibrium with gas pressures up to ca. 30 atm) for measurement of reaction kinetics. We have used this apparatus to follow the reaction of dioxygen with bovine cytochrome c oxidase following photolysis of the fully reduced CO ligated enzyme up to a dioxygen concentration of 16 mM. The observed rate dependence on [02] follows saturation kinetics and was fit to a limiting rate of 1.0 X 10(6) s(-1). This value is approximately the same as that for the thermal loss of CO to solution from the transient CuB bound state formed upon photolysis of the heme-CO complex. Implications for the mechanism of O2 binding and reduction by the heme-copper oxidases are discussed.

Animals↗
PubMed1994

Vasoactive intestinal peptide stimulates neuropeptide Y gene expression and causes neurite extension in PC12 cells through independent mechanisms.

Vasoactive intestinal peptide (VIP) is widely recognized as a regulator of tyrosine hydroxylase via a mechanism of trans-synaptic activation. Subsets of adrenal medullary cells and postganglionic sympathetic nerves coexpress the peptide neurotransmitter neuropeptide Y (NPY) with catecholamines. Using PC12 cells transiently expressing a fusion gene in which the bacterial enzyme chloramphenicol acetyltransferase (CAT) is under the control of 700 base pairs of the 5' flanking region of the NPY gene, we have studied the role of VIP and the related peptide pituitary adenylate cyclase activating peptide (PACAP) in regulating NPY gene transcription. Both VIP and PACAP stimulated expression of the NPY gene through activation of cAMP-dependent protein kinase. PACAP was 1000-fold more potent in eliciting this response compared to VIP and activity resided in its N-terminal 27 amino acids. Both VIP and PACAP caused a subpopulation (approximately 50%) of PC12 cells to undergo profound morphological changes in that the cells extended long, slender neurites with prominent growth cones. This change in morphology was unaffected by preincubating cells with inhibitors of either cAMP-dependent protein kinase or calcium/phospholipid-dependent protein kinase. A trophic role for either VIP or PACAP in regulating sympathetic nerve function is proposed.

Animals↗
PubMed1990

Serologic investigations in a New York City cohort of parenteral drug users.

Human immunodeficiency virus (HIV) infection continues to be a major health problem for society. Intravenous drug users are the second largest risk group for HIV infection. The disease primarily affects immunologic functioning. This study examined the inherent immunologic dysfunction by measuring the seroprevalence of infection against pathogens often associated with HIV infection. Additionally, chi square analysis was used to compare intravenous drug users with a non-drug-using control group to see if any difference existed in the prevalence of antinuclear antibody, rheumatoid factor, abnormal titer of antibody to Toxoplasma gondii, cytomegalovirus, and herpes simplex virus (types 1 and 2). The intravenous drug users had a significantly greater level of antibody titers for antinuclear antibody and Toxoplasma gondii than did controls. Abnormal serologic results were not significantly associated with HIV seropositivity. The findings of this study suggest that intravenous drug users experience a greater prevalence of alteration in serologic markers unrelated to HIV exposure.

Adult↗
PubMed1986

Differential accumulation of plant defense gene transcripts in a compatible and an incompatible plant-pathogen interaction.

Phenylalanine ammonia-lyase and chalcone synthase catalyze the first reaction of phenylpropanoid biosynthesis and the first reaction of a branch pathway specific for flavonoid-isoflavonoid biosynthesis, respectively. These enzymes are key control elements in the synthesis of kievitone, phaseollin, and related isoflavonoid-derived phytoalexins. RNA blot hybridization with 32P-labeled cDNA sequences was used to demonstrate marked accumulation of phenylalanine ammonia-lyase and chalcone synthase mRNAs in excision-wounded hypocotyls of Phaseolus vulgaris L. (dwarf French bean) and during race-cultivar-specific interactions between hypocotyls of P. vulgaris and the partially biotrophic fungus Colletotrichum lindemuthianum, the causal agent of anthracnose. In an incompatible interaction (host resistant), early concomitant accumulation of phenylalanine ammonia-lyase and chalcone synthase mRNAs, localized mainly but not entirely in tissue adjacent to the site of infection, was observed prior to the onset of phytoalexin accumulation and expression of localized, hypersensitive resistance. In contrast, in a compatible interaction (host susceptible) there was no early accumulation of these transcripts; instead, there was a delayed widespread response associated with phytoalexin accumulation during attempted lesion limitation. Two-dimensional gel electrophoresis of [35S]methionine-labeled polypeptides synthesized in vitro by translation of isolated polysomal RNA demonstrated stimulation of the synthesis of characteristic sets of phenylalanine ammonia-lyase and chalcone synthase isopolypeptides in directly infected tissue and distant, hitherto uninfected tissue in both compatible and incompatible interactions. Our data show that specific accumulation of plant defense gene transcripts is a key early component in the sequence of events leading to expression of defense responses in wounded tissue and in infected tissue during race-cultivar-specific interactions and that an elicitation signal is transmitted intercellularly in response to infection.

Base Sequence↗
PubMed1985

Co-ordinated synthesis of phytoalexin biosynthetic enzymes in biologically-stressed cells of bean (Phaseolus vulgaris L.).

Changes in the rates of synthesis of three enzymes of phenyl-propanoid biosynthesis in Phaseolus vulgaris L. (dwarf French bean) have been investigated by immunoprecipitation of [S]methionine-labeled enzyme subunits with mono-specific antisera. Elicitor causes marked, rapid but transient co-ordinated increases in the rate of synthesis of phenyl-alanine ammonia-lyase, chalcone synthase and chalcone isomerase concomitant with the phase of rapid increase in enzyme activity at the onset of accumulation of phenyl-propanoid-derived phytoalexin antibiotics in suspension cultures of P. vulgaris. Co-ordinate induction of enzyme synthesis is also observed in hypocotyl tissue during race:cultivar-specific interactions with Colletotrichum lindemuthianum, causal agent of anthracnose. In an incompatible interaction (host resistant) there are early increases apparently localized to the initial site of infection prior to the onset of phytoalexin accumulation and expression of hypersensitive resistance. In contrast, in a compatible interaction (host susceptible) there is no induction of synthesis in the early stages of infection, but a delayed widespread response at the onset of lesion formation associated with attempted lesion limitation. It is concluded that expression of the phytoalexin defense response in biologically stressed cells of P. vulgaris characteristically involves co-ordinate induction of synthesis of phytoalexin biosynthetic enzymes.

Journal Article↗
PubMed1985

Accumulation of hydroxyproline-rich glycoprotein mRNAs in response to fungal elicitor and infection.

Hydroxyproline-rich glycoproteins (HRGPs) are important structural components of plant cell walls and also accumulate in response to infection as an apparent defense mechanism. Accumulation of HRGP mRNA in biologically stressed bean (Phaseolus vulgaris L.) cells was monitored by blot hybridization with (32)P-labeled tomato genomic HRGP sequences. Elicitor treatment of suspension-cultured cells caused a marked increase in hybridizable HRGP mRNA. The response was less rapid but more prolonged than that observed for mRNAs encoding enzymes of phytoalexin biosynthesis. HRGP mRNA also accumulated during race:cultivar-specific interactions between bean hypocotyls and the partially biotrophic fungus Colletotrichum lindemuthianum, the causal agent of anthracnose. In an incompatible interaction (host resistant) there was an early increase in HRGP mRNA correlated with expression of hypersensitive resistance; whereas, in a compatible interaction (host susceptible), marked accumulation of HRGP mRNA occurred as a delayed response at the onset of lesion formation. In both interactions, mRNA accumulation was observed in uninfected cells distant from the site of fungal inoculation, indicating intercellular transmission of an elicitation signal.

Journal Article↗
PubMed1984

Differential induction of chalcone synthase mRNA activity at the onset of phytoalexin accumulation in compatible and incompatible plant-pathogen interactions.

Changes in the mRNA activity of chalcone synthase, the first enzyme of phenylpropanoid metabolism specific to flavonoid/isoflavonoid biosynthesis, have been investigated in relation to expression of the phytoalexin defense response in race-cultivar specific interactions between hypocotyls of Phaseolus vulgaris and the partially biotrophic fungus Colletotrichum lindemuthianum, causal agent of anthracnose. In an incompatible interaction (host resistant) there is an early but localized increase in chalcone synthase mRNA activity prior to the onset of accumulation of the phenylpropanoid-derived phytoalexin phaseoflin and expression of hypersensitive resistance. In contrast, in a compatible interaction (host susceptible) there is no induction of mRNA activity in the early stages of infection but rather a delayed, widespread increase during attempted lesion limitation at the onset of symptom development. The data indicate that control of phytoalexin gene expression is a key early component in the defense responses of biologically stressed cells during a race-cultivar specific host-pathogen interaction.

Journal Article↗
PubMed1979

Experience with a simplified trauma registry: profile of trauma at a university hospital.

A simplified computer-based trauma registry system with well-defined limits of data capture is presented. This registry was utilized to describe the profile of trauma at a university hospital. In 1 year there were 882 trauma victims hospitalized, with an overall mortality of 3.3%. The majority of the patients had relatively minor injuries, primarily involving soft tissue and bone. Severe multiple trauma was associated with a significant mortality. Intracranial or intra-abdominal injuries occurred in less than 10% of the patients. Transport accidents, falls, and assaults were the cause of injury in 70%. Key access to specific information about the trauma patient population demonstrated the potential of the registry system. The advantages and limitations of the registry are discussed.

Adolescent↗
PubMed1978

Column chromatographic separation of deoxynucleotide monomethyl esters and related products of the reaction of n-methyl-n-nitrosourea with deoxynucleoside monophosphates.

Dowex 1 (HCOO-) column chromatographic procedures are described for the resolution of deoxynucleoside monophosphate monomethyl esters and other related products of the reaction of the carcinogen N-methyl-N-nitrosourea with deoxynucleoside monophosphates. These procedures provide convenient methods for the isolation and estimation of the products of these reactions.

Chemical Phenomena↗