Unraveling the "Greener Pastures" Concept: The Phenomenology of Internationally Educated Occupational Therapists.

The Philippines is one of the major labor exporters for health care workers in the world and occupational therapists are the second most likely professionals behind nurses to work in "greener pastures" overseas. This phenomenological study describes the migration experiences of Philippine-trained occupational therapists working in high-income, Anglophone countries. Researchers conducted online interview for 15 participants who were previously/currently unemployed/underemployed.

The effect of high level tennis matches on urine steroid profiles in professional tennis players.

Aim: Modern day, tennis matches are characterized by shorter and more intense efforts with players enduring great physical and psychological stress. The aim of this study was to evaluate acute changes in the urinary steroid profile of elite tennis players following professional tournament matches.

Methods: Eight professional male tennis players participated in this study.

SHBG, plasma, and urinary androgens in weight lifters after a strength training.

Previous studies with different results have suggested that total and bioavailable testosterone levels are modified by physical exercise. Such changes may be related to modifications in cortisol levels and could be reflected in some urine androgens. To determine how weight lifting training may affect serum and urinary androgens, we measured total serum testosterone (T), cortisol, sex hormone binding globulin (SHBG) and urinary testosterone, epitestosterone, androsterone, and etiocholanolone, in a group of 19 elite weight lifters after 20 weeks of training.

Urinary steroid profile after the completion of concentric and concentric/eccentric trials with the same total workload.

High intensity strength training causes changes in steroid hormone concentrations. This could be altered by the muscular contraction type: eccentric or concentric. The aim of this study was to compare the effect of the completion of a short concentric (CON) and concentric/eccentric (CON/ECC) trial on the urinary steroid profile, both with the same total work.

Heterocyclic amines in griddled beef steak analysed using a single extract clean-up procedure.

Heterocyclic amines (HAs), which are potent mutagenic and carcinogenic substances, are formed in muscle meats during their cooking under ordinary conditions. In this work, we measured the concentration of 15 HAs in different samples of griddled beef steak, which is one of the most consumed meat items is Spain. Three samples were obtained from different restaurants, and the other sample was cooked under controlled conditions to a well-done degree of doneness.

Glutamine synthetase degradation is controlled by oxidative proteolysis in the marine cyanobacterium Prochlorococcus marinus strain PCC 9511.

Prochlorococcus is one of the most important primary producers on Earth; its unusual features and ecological importance have made it a model organism, but nutrient assimilation has received little attention. Glutamine synthetase (GS) plays a key role in nitrogen metabolism and its central position justifies the fine regulation of this enzyme. The aim of this work is to demonstrate the involvement of metal-catalyzed oxidation (MCO) in the control of the biological activity and turnover of GS from Prochlorococcus.

Adsorption of water vapor by poly(styrenesulfonic acid), sodium salt: isothermal and isobaric adsorption equilibria.

Air conditioning and dehumidifying systems based on sorption on solids are of great interest, especially in humid climates, because they allow reduction of thermal loads and use of chlorofluorocarbons. Previous studies have shown that hydrophilic polymers such as sulfonic polymers can have very high performance in water adsorption from air. The aim of this study was to characterize the water vapor adsorption properties of fully sulfonated and monosulfonated poly(styrenesulfonic acid), sodium salt, and to elucidate the mechanism of adsorption on these materials.

Occurrence of heterocyclic amines in several home-cooked meat dishes of the Spanish diet.

Heterocyclic amines (HAs) were determined in several of the most frequently eaten meat dishes in Spain such as fried beef hamburger, fried pork loin, fried chicken breast, fried pork sausages, griddled chicken breast, griddled lamb steak and griddled beef steak. All of the products tested were household cooked. The HAs were analysed in the selected meat dishes using an analytical method based on solid-phase extraction followed by liquid chromatography coupled to tandem mass spectrometry.

Analysis of heterocyclic amines in food products: interlaboratory studies.

A feasibility study and two interlaboratory exercises on the determination of selected heterocyclic amines (HAs) in beef extract, organised in the framework of a European project, are presented. The aim of these exercises was to improve the quality of the laboratories and to evaluate the performance of a standardised analytical method and also the methods currently used by each of the participants for the analysis of these compounds. Three lyophilised portions of a commercial beef material previously spiked with HAs at different concentration levels ranging from 10 to 75 ng g(-1) were used as laboratory reference materials (lot A, B and C).

Ion-trap tandem mass spectrometry for the determination of heterocyclic amines in food.

Heterocyclic amines (HAs) are mutagenic compounds to which humans are regularly exposed through diet. Due to the high complexity of the sample matrix and the low level of concentration of HAs, sensitive and selective analytical methodologies are required. Here we describe a methodology based on liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry using an ion-trap to analyse HAs.

Glutamine synthetase from the marine cyanobacteria Prochlorococcus spp: characterization, phylogeny and response to nutrient limitation.

The regulation of glutamine synthetase (EC 6.3.1.

Effect of food deprivation on oxidative stress biomarkers in fish (Sparus aurata).

Oxidative stress in fish (Sparus aurata) as a consequence of food restriction and fasting, has been studied. Four groups of fish were maintained for 46 days under different conditions of food supplementation: a control group with no food restriction (ratio of food/fish of 2% w/w), two groups of animals with restricted food supplement (1 and 0.5%) and a fasting group (no meal addition).

Multistep mass spectrometry of heterocyclic amines in a quadrupole ion trap mass analyser.

The fragmentation of heterocyclic amines (HAs) in an ion trap was studied by means of the infusion of methanolic solutions containing the compounds under assay, and using an atmospheric pressure chemical ionization (APCI) as ion source. The MS(n) spectra obtained for compounds included in the same family, either aminoimidazoazaarenes (AIAs) or carbolines, were compared in order to propose fragmentation pathways for each HA. Moreover, labelled AIAs were used to establish the mechanisms.

In vivo regulation of glutamine synthetase activity in the marine chlorophyll b-containing cyanobacterium Prochlorococcus sp. strain PCC 9511 (oxyphotobacteria).

The physiological regulation of glutamine synthetase (GS; EC 6.3.1.

Separation of heteroaromatic amines in food products.

In recent years, many studies have dealt with the role of certain heteroaromatic amines (HAs) as mutagenic compounds, and their occurrence in foodstuffs. Here we examine the determination of HAs, focusing on the analytical strategies for their extraction and preconcentration from several matrices. We summarise the properties of heteroaromatic amines and the main drawbacks involved in their analysis, and then concentrate on the separation procedures, sorbents and solvents used in the sample treatment.

Comparison of different commercial solid-phase extraction cartridges used to extract heterocyclic amines from a lyophilised meat extract.

Heterocyclic amines are a group of potent mutagenic compounds which are generated when muscle meat is cooked. Since they are possible human carcinogens, these mutagens have received considerable attention in recent years, and several analytical techniques have been developed for their quantification. Although the purification step is one of the most important, there are a great number of variables influencing the recovery of the amines, especially when real samples are analysed.

Determination of heterocyclic aromatic amines in meat extracts by liquid chromatography-ion-trap atmospheric pressure chemical ionization mass spectrometry.

When protein-rich foods are processed under normal cooking conditions, heterocyclic aromatic amines (HAAs) can be generated at a few parts per billion level. In this work, we have analyzed the HAAs present in a lyophilized meat extract by means of a simplified solid-phase extraction procedure. All the analytes were collected in a single extract with recoveries in the range of 45.

Evaluation of different clean-up procedures for the analysis of heterocyclic aromatic amines in a lyophilized meat extract.

Along with other mutagenic and carcinogenic contaminants in foods such as aflatoxins, and polycyclic aromatic hydrocarbons, heterocyclic aromatic amines (HAAs) have received considerable attention in recent years. A major drawback in the analysis of HAAs in foods is their very low level of concentration (0.1 50 ng g-1) as well as matrix interferences.

Formation of 8-oxoguanine in cellular DNA of Escherichia coli strains defective in different antioxidant defences.

This paper examines the relationship in Escherichia coli between the in vivo content of 8-oxoguanine (8-oxoG) in chromosomal DNA and deficiencies of various key antioxidant defences. The structural genes for catalases (katG and katE), cytosolic superoxide dismutases (sodA and sodB) or formamidopyrimidine-DNA glycosylase (fpg) were inactivated to obtain bacterial strains lacking the scavenger enzymes for H2O2 or O2.- or the DNA repair protein for 8-oxoG.

Methods for purification of glutathione peroxidase and related enzymes.

The different preparative techniques and related analytical methods used for purification of glutathione peroxidase, glutathione transferase and glutathione reductase, described in papers published in the last ten years, have been reviewed in this article. Among the different purification techniques, chromatography has played a relevant role, being reported in all the papers reviewed, whereas other preparative techniques such as electrophoresis and isoelectric focusing were less employed and have been reported in only ca. 3% of cases.

Methods for chromatographic and electrophoretic separation and assay of NADP oxidoreductases.

The different techniques described in purification protocols for pyridine nucleotide-dependent enzymes have been reviewed, covering mainly the papers published in the past six years. Chromatography was reported in 100% of reviewed papers and among the chromatographic techniques, affinity chromatography was the most used (ca. 92%), followed by ion-exchange chromatography (ca.

The levels of ribonucleotide reductase, thioredoxin, glutaredoxin 1, and GSH are balanced in Escherichia coli K12.

The dithiol forms of thioredoxin and glutaredoxin are hydrogen donors for ribonucleotide reductase. We have determined the intracellular levels of ribonucleotide reductase (RRase), thioredoxin (Trx), glutaredoxin 1 (Grx1), and glutathione (GSH) and the glutathione redox status in new Escherichia coli K12 strains lacking thioredoxin (trxA-), glutaredoxin 1 (grxA-), and/or GSH (gshA-) or overproducing Trx or Grx1 from multicopy plasmids. We propose a regulatory network in which RRase levels are balanced with those of Trx, Grx1, and GSH so that deficiency or overproduction of one component would promote the opposite effect on the others to maintain a balanced supply of deoxyribonucleotides.

Trends in HIV seroprevalence in men who have sex with men: New York City Department of Health sexually transmitted disease clinics, 1988-1993.

Objective: To measure HIV seroprevalence trends in a primarily non-white sample (n = 1618) of men who have sex with men (MSM). The MSM were sampled at New York City Department of Health (NYC-DOH) sexually transmitted disease (STD) clinics during 1988-1993.

Design: Unlinked HIV-1 serosurvey using remnant serum originally drawn for routine syphilis screening.

Increasing HIV-1 seroprevalence associated with genital ulcer disease, New York City, 1990-1992.

Objective: To measure HIV seroprevalence trends associated with sexually transmitted diseases (STD) causing ulcerative lesions [genital ulcer disease (GUD)], such as syphilis, chancroid and genital herpes, in New York City between 1990 and 1992.

Design: Unlinked HIV-1 serosurvey using remnant serum drawn originally for routine syphilis screening.

Setting And Patients: Consecutive sample of patients presenting to New York City Department of Health STD clinics for STD examination (n = 41,678).

Rapid determination of glutathione status in fish liver using high-performance liquid chromatography and electrochemical detection.

A rapid and sensitive method for the detection of reduced (GSH), oxidised (GSSG) and protein-bound (PSSG) glutathione in fish liver, using reversed-phase HPLC with electrochemical detection has been developed. Separation was carried out isocratically at room temperature using 0.020 M sodium phosphate, pH 2.