Stoichiometry of the topa quinone biogenesis reaction in copper amine oxidases.

The stoichiometry of the topa quinone biogenesis reaction in phenylethylamine oxidase from Arthrobacter globiformis (AGAO) has been determined. We have shown that the 6e- oxidation of tyrosine to topa quinone (TPQ) consumes 2 mol of O2 and produces 1 mol of H2O2/mol of TPQ formed. The rate of H2O2 production is first-order (kobs = 1.

Underemployment and alcohol misuse in the National Longitudinal Survey of Youth.

Objective: This study measured the impact of unemployment and underemployment on alcohol misuse.

Method: A panel of respondents from the National Longitudinal Survey of Youth was studied in 1984-85 and 1988-89. In each pair of years, the effect of employment change (e.

Selective peptide antagonist of the class E calcium channel from the venom of the tarantula Hysterocrates gigas.

We describe the first potent and selective blocker of the class E Ca2+channel. SNX-482, a novel 41 amino acid peptide present in the venom of the African tarantula, Hysterocrates gigas, was identified through its ability to inhibit human class E Ca2+ channels stably expressed in a mammalian cell line. An IC50 of 15-30 nM was obtained for block of the class E Ca2+ channel, using either patch clamp electrophysiology or K+-evoked Ca2+ flux.

The nos (nitrous oxide reductase) gene cluster from the soil bacterium Achromobacter cycloclastes: cloning, sequence analysis, and expression.

The nitrous oxide (N2O) reductase (nos) gene cluster from Achromobacter cycloclastes has been cloned and sequenced. Seven protein coding regions corresponding to nosR, nosZ (structural N2O reductase gene), nosD, nosF, nosY, nosL, and nosX are detected, indicating a genetic organization similar to that of Rhizobium meliloti. To aid homology studies, nosR from R.

Reduction of 3,4-diaminopyridine-induced biogenic amine synthesis and release in rat brain by gabapentin.

The anticonvulsant drug gabapentin has been shown recently to exhibit anxiolytic and analgesic actions in animals. Such actions have been postulated in part to reflect effects on biogenic amine neuronal activity. Therefore the effects of gabapentin on biogenic amine neuronal activity were assessed by measuring the synthesis of norepinephrine (NE), dopamine (DA) and serotonin (5-HT) in rat brain and on the release of [3H] NE from rat hippocampal slices both in the presence and absence of the depolarizing agent 3,4-diaminopyridine (DAP).

Assessment of endothelin receptor subtype-mediated increases of [Ca2+]i in distinct rat cell types using fluorimetric imaging.

Activation of endothelin (ET) receptor subtypes by various agonists causes an increase in [Ca2+]i in different cell types. This effect can be readily monitored in a 96-well plate format by detecting 1-s fluorescence changes of cell-permeant, Ca(2+)-sensitive dyes (e.g.

A summary of mechanistic hypotheses of gabapentin pharmacology.

Although the cellular mechanisms of pharmacological actions of gabapentin (Neurontin) remain incompletely described, several hypotheses have been proposed. It is possible that different mechanisms account for anticonvulsant, antinociceptive, anxiolytic and neuroprotective activity in animal models. Gabapentin is an amino acid, with a mechanism that differs from those of other anticonvulsant drugs such as phenytoin, carbamazepine or valproate.

Development of quinolone-resistant Campylobacter fetus bacteremia in human immunodeficiency virus-infected patients.

Campylobacter fetus subspecies fetus has been recognized as a cause of systemic illness in immunocompromised hosts, including relapsing bacteremia in human immunodeficiency virus (HIV)-infected patients. Acquired resistance to quinolone therapy, while reported for a variety of bacteria, including Campylobacter jejuni, has not been previously documented for C. fetus.

Effect of favorable employment change on alcohol abuse: one- and five-year follow-ups in the National Longitudinal Survey of Youth.

Job loss has been linked to adverse outcomes such as alcohol abuse, but improved employment, usually assumed to be beneficial, has seldom been evaluated and may not help with addictive disorders. Using the National Longitudinal Survey of Youth, young adults who were unemployed or underemployed (low income or involuntary part-time) in 1984 were followed up in 1985 and 1989. Controlling for 1984 alcohol abuse, there were no effects of positive employment change on 1985 symptoms, but there were significant restorative effects on 1985 binge drinking among those who were heavy drinkers in 1984.

Crystal structures of the copper-containing amine oxidase from Arthrobacter globiformis in the holo and apo forms: implications for the biogenesis of topaquinone.

The crystal structures of the copper enzyme phenylethylamine oxidase from the Gram-positive bacterium Arthrobacter globiformis (AGAO) have been determined and refined for three forms of the enzyme: the holoenzyme in its active form (at 2.2 A resolution), the holoenzyme in an inactive form (at 2.8 A resolution), and the apoenzyme (at 2.

Adjunctive corticosteroid therapy for tuberculosis: a critical reappraisal of the literature.

An extensive, although largely forgotten, literature addresses the utility of adjunctive corticosteroid therapy in the management of tuberculosis. Corticosteroid therapy probably improves neurological outcomes of, and decreases mortality due to, tuberculous meningitis of moderate severity. Although therapy for tuberculous pericarditis is simplified (with less need for operative intervention) by adjunctive corticosteroid administration and there are fewer deaths, the incidence of subsequent constriction is not changed.

Flt3 ligand enhances the yield of primitive cells after Ex vivo cultivation of CD34+ CD38dim cells and CD34+ CD38dim CD33dim HLA-DR+ cells.

Flt3 ligand (FL) has been proposed as a possible modulator of early hematopoietic cell growth. The purpose of this study was to analyze the impact of FL on ex vivo expansion of hematopoietic cells obtained from adult donors. We sought to precisely identify hematopoietic populations responsive to FL and to quantitate the ability of FL to enhance the survival and/or proliferation of early hematopoietic precursors in a stroma-free culture system.

Spook house sporotrichosis. A point-source outbreak of sporotrichosis associated with hay bale props in a Halloween haunted-house.

While isolated cases of sporotrichosis typically occur following contact with contaminated plant materials, outbreaks are distinctly unusual. A temporal increase in the incidence of sporotrichosis in a dermatology practice at a military installation in southwestern Oklahoma prompted an investigation. Patients with sporotrichosis presenting to a single dermatologist in the winter of 1992-1993 were interviewed, epidemiological data were collected, and fungal cultures were obtained from incriminated hay fields.

Effect of underemployment on school-leavers' self-esteem.

This study explores whether self-esteem is adversely affected by economic underemployment as defined by unemployment, involuntary part-time employment, intermittent unemployment, and poverty income in a group of recent school-leavers. Results indicate that self-esteem was significantly lower in each of the economically underemployed groups relative to the adequately employed after controlling for early self-esteem, socio-economic status, gender, ethnicity, aptitude, age, and education. There were no differences in self-esteem among the economically underemployed groups after adjusting for the control variables.

Mechanistic studies of topa quinone biogenesis in phenylethylamine oxidase.

An alternative purification for apophenylethylamine oxidase from Arthrobacter globiformis has been developed, which avoids the use of possible contaminants that may interfere with the topa quinone (TPQ) self-processing reaction. The binding of Cu(II) and the kinetics of TPQ formation in these enzyme preparations have been reinvestigated. Our results show that Cu(II) is not significantly reduced when added to the apoprotein under anaerobic conditions.

Identification of the quinone cofactor in a lysyl oxidase from Pichia pastoris.

A copper amine oxidase from Pichia pastoris is the only known non-mammalian lysyl oxidase [Tur, S.S. and Lerch, K.

pS2 expression induced by American ginseng in MCF-7 breast cancer cells.

Background: Alternative medicines are frequently used by patients with breast cancer for general health benefits. American ginseng, an herbal remedy, purportedly alleviates treatment-induced postmenopausal symptoms.

Methods: Estrogenic potential of American ginseng root extract to induce the expression of pS2, an estrogen-regulated gene, was evaluated in breast cancer cell lines MCF-7, T-47D, and BT-20 by Northern and Western blot analysis.

A crosslinked cofactor in lysyl oxidase: redox function for amino acid side chains.

A previously unknown redox cofactor has been identified in the active site of lysyl oxidase from the bovine aorta. Edman sequencing, mass spectrometry, ultraviolet-visible spectra, and resonance Raman studies showed that this cofactor is a quinone. Its structure is derived from the crosslinking of the epsilon-amino group of a peptidyl lysine with the modified side chain of a tyrosyl residue, and it has been designated lysine tyrosylquinone.

Crystal structure of a eukaryotic (pea seedling) copper-containing amine oxidase at 2.2 A resolution.

Background: Copper-containing amine oxidases catalyze the oxidative deamination of primary amines to aldehydes, in a reaction that requires free radicals. These enzymes are important in many biological processes, including cell differentiation and growth, would healing, detoxification and signalling. The catalytic reaction requires a redox cofactor, topa quinone (TPQ), which is derived by post-translational modification of an invariant tyrosine residue.

Validation of catheter semiquantitative culture technique for nonstaphylococcal organisms.

The catheter semiquantitative culture roll tip technique has been validated as a discriminator between non-catheter-related bacteremias and catheter-related bacteremias (CRBs) caused by Staphylococcus species. However, this technique has not been specifically validated when used for the evaluation of catheters infected with organisms other than staphylococci. We reviewed catheters that had been submitted for semiquantitative roll tip culture as well as hospital records to determine clinical correlates of infection.