Saliva cortisol in relation to aircraft noise exposure: pooled-analysis results from seven European countries.

Background: Many studies have demonstrated adverse effects of exposure to aircraft noise on health. Possible biological pathways for these effects include hormonal disturbances. Few studies deal with aircraft noise effects on saliva cortisol in adults, and results are inconsistent.

A vanadium(IV) pyrazolate metal-organic polyhedron with permanent porosity and adsorption selectivity.

A vanadium(IV) pyrazolate-based open metal-organic polyhedron of [V3(μ3-O)O(OH)2(μ4-BPD)1.5(μ-HCOO)3] (BDP = benzene-1,4-bipyrazolate) formulation gives rise to a porous crystal structure exhibiting micro and mesoporosity which is useful for selective adsorption of gases.

Natural inhibitors of poly(ADP-ribose) polymerase-1.

Poly(ADP-ribose) polymerases (PARPs) are enzymes that catalyze the transfer of ADP-ribose units from β-nicotinamide adenine dinucleotide (NAD(+)) to acceptor proteins. PARP-1 is responsible for more than 90 % of protein poly-ADP-ribosylation in the brain and may play a role as a molecular switch for cell survival and death. The functional roles of PARP-1 are largely mediated by its activation after binding to damaged DNA.

Inhibition of poly(ADP-ribose) polymerase-1 attenuates the toxicity of carbon tetrachloride.

Carbon tetrachloride (CCl(4)) is routinely used as a model compound for eliciting centrilobular hepatotoxicity. It can be bioactivated to the trichloromethyl radical, which causes extensive lipid peroxidation and ultimately cell death by necrosis. Overactivation of poly(ADP-ribose) polymerase-1 (PARP-1) can rapidly reduce the levels of β-nicotinamide adenine dinucleotide and adenosine triphosphate and ultimately promote necrosis.

The kinetics of reductive dehalogenation of a set of halogenated aliphatic hydrocarbons in anaerobic sediment slurries.

Disappearance rate constants are reported for the reductive transformation of 17 halogenated aliphatic hydrocarbons in anaerobic sediment-water samples. Statistical experimental design in combination with multivariate chemical characterization of their chemical properties was used to select the compounds. Degradation followed pseudo first-order kinetics through at least two half-lives for 15 of the 17 compounds.

The Pertussis Serological Potency Test. Collaborative study to evaluatereplacement of the Mouse Protection Test.

The Pertussis Serological Potency Test (PSPT)--based on in vitro assessment of the humoral immune response against Bordetella pertussis--was developed as an alternative for the Mouse Protection Test (MPT). A small-scale collaborative study was carried out in five laboratories to evaluate the relevance and reliability of the PSPT. The study has been divided into three separate phases, each with its own objective.

Standardization of acellular pertussis vaccines.

In comparison with the current whole cell pertussis vaccine, the new generation of acellular pertussis vaccines opens new opportunities to improve the standardization of the product, because well defined and characterized components are used in these new products.However, different compositions, purification and inactivation methods are used by different manufacturers. Consequently the various acellular pertussis vaccines in the world are difficult to compare in a meaningful manner using simple laboratory tests.

The genetic basis of the phase variation repertoire of lipopolysaccharide immunotypes in Neisseria meningitidis.

Neisseria meningitidis strains express a diverse range of lipopolysaccharide (LPS) structures that have been classified into 12 immunotypes. A feature of meningococcal LPS is the reversible, high-frequency switching of expression (phase variation) of terminal LPS structures. A number of studies are strongly suggestive of a key role for these terminal structures, and their phase-variable expression, in pathogenesis.

Molecular epidemiology of poliovirus infection in Tunisia.

This report is an overview of poliomyelitis surveillance in Tunisia from 1991 to 1996. In all, 2088 stool specimens, collected from 152 acute flaccid paralysis (AFP) cases and from 1747 of their healthy contacts were investigated. Virus isolation was done systematically in RD and HEp-2C cell lines and isolated viruses were typed by sero-neutralisation as polioviruses or non-polio enteroviruses.

Supercritical fluid extraction of methyltestosterone, nortestosterone and testosterone at low ppb levels from fortified bovine urine.

A multi-residue supercritical fluid extraction (SFE) method is proposed for the isolation of nortestosterone, testosterone and methyltestosterone from bovine urine. Prior to SFE, bovine urine was hydrolyzed and then fortified with the three steroids at 100 ng/ml and 50 ng/ml each for HPLC analysis and 25 ng/ml and 12.5 ng/ml each for GC-MS analysis.

Obesity: a growing problem.

Obesity, defined as a body mass index (BMI) of 30 kg/m2 or more, is common in many parts of the world, especially in the established market economies, the former socialist economies of Europe, Latin America, the Caribbean and the Middle Eastern Crescent. As many as 250 million people worldwide may be obese (7% of the adult population) and two to three times as many may be considered overweight. The prevalence of obesity seems to be increasing in most parts of the world, even where it used to be rare.

Societal and personal costs of obesity.

The economic costs of obesity can be broken down into three levels: 1. DIRECT COSTS: Costs to the community, related to the diversion of resources to the diagnosis and treatment of diseases directly related to obesity, as well as the treatment of obesity itself. These costs have been estimated to vary between 1-5% of total healthcare costs for various countries.

The potential of restricted access media columns as applied in coupled-column LC/LC-TSP/MS/MS for the high-speed determination of target compounds in serum. Application to the direct trace analysis of salbutamol and clenbuterol.

This study investigated the potential of restricted access media (RAM) columns used as a first column in coupled-column LC hyphenated to thermospray tandem mass spectrometry (LC/LC-TSP/MS/MS) for the fast, selective, and sensitive determination of target drugs in serum samples. Because of their wide range in polarity, salbutamol and clenbuterol were chosen as model compounds and representatives of the class of beta 2-agonists. Three types of RAM columns were tested: (i) Pinkerton ISRP (internal surface reversed phase, 5 microns), (ii) SPS (semipermeable surface, 5 microns C18), and (iii) RP-18 ADS (alkyl-diol silica, 25 microns).

Pharmacokinetics of the enantiomers of bupivacaine and mepivacaine after epidural administration of the racemates.

Unlabelled: We investigated the pharmacokinetics of the enantiomers of bupivacaine and mepivacaine after epidural injection of the racemate of each drug into six surgical patients. After epidural administration of either bupivacaine/HCl (115 mg) or mepivacaine/HCl (460 mg), blood samples were collected for 24 h. Unbound fractions were determined by using ultrafiltration for bupivacaine and equilibrium dialysis for mepivacaine.

Risk assessment for the harmful effects of UVB radiation on the immunological resistance to infectious diseases.

Risk assessment comprises four steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization. In this study, the effects of increased ultraviolet B(UVB, 280-315 nm) radiation on immune functions and the immunological resistance to infectious diseases in rats were analyzed according to this strategy. In a parallelogram approach, nonthreshold mathematical methods were used to estimate the risk for the human population after increased exposure to UVB radiation.

Environmental risk assessment of musk ketone and musk xylene in The Netherlands in accordance with the EU-TGD.

An environmental risk assessment has been carried out for musk ketone and musk xylene according to the EU Technical Guidance Document for Environmental Risk Assessment for New and Existing Substances [1]. Musk ketone and musk xylene are used in fragrances for cosmetics and household products. For the fragrance industry these are important fragrance ingredients because of their excellent substantivity as well as for their unique smell, which determines largely the odor of a product.

Heterogeneity of epithelial cells in the rat thymus.

The morphological heterogeneity of the thymic epithelium has been well documented both at the light and electron microscopic level. Immunohistochemistry has revealed four broad classes of epithelial cells (EC): subcapsule/perivascular, cortical, medullary EC, and medullary Hassall's corpuscles. Ultrastructural analysis has revealed further heterogeneity.

Effect of growth rate, nutrient limitation and succinate on expression of TOL pathway enzymes in response to -xylene in chemostat cultures (pWW0).

Previous studies have shown that expression of the toluene and - and -xylene degradation pathway in (pWW0) is subject to catabolite repression by succinate. We report here that the expression level of the upper part of this so-called TOL pathway in cells grown in chemostat culture is strongly influenced by nutrient limitation when -xylene is the sole carbon and energy source. The benzylalcohol dehydrogenase (BADH) levels in cells that are growth-limited by anabolic processes [sulphate (S)-, phosphate (P)- or nitrogen (N)-limiting conditions] were 3-12% of those in cells growing under oxygen limitation (when catabolism limits growth).

Structural identifiability of PBPK models: practical consequences for modeling strategies and study designs.

Physiologically based pharmacokinetic (PBPK) models usually contain unknown parameters that need to be estimated by calibration to concentration-time profiles from in vivo experiments. However, even with error-free data, the number of parameters that can be estimated in this way is limited, depending on the particular situation. This paper introduces the concept of structural identifiability of a model, a requirement to make the estimation of parameters by calibration a meaningful undertaking.