bluuebunny/crossref_metadata_2025 huggingface dataset:
Ionized calcium: indications and advantages of its measurement Bestimmung des ionisierten Calciums: Indikationen und Vorteile
Authors: Onifade Kehinde U. , Mohammad Amin A. , Petersen John R. , Okorodudu Anthony O.
Published: August 2005

Plasma calcium exists in three forms: ionized, protein bound, and complexed with anions. Although all the forms are in equilibrium with each other, only the plasma ionized calcium has been reported to be physiologically active. Thus it is the preferred constituent for use in patient care. Despite this fact, the use of plasma total calcium concentration continues to be the predominant test for patient care in most hospitals mainly because of availability and ease of measurement. It has been documented that the use of total calcium is unreliable in cases where there is a change in the protein-calcium binding characteristics as in patients with hypergammaglobulinemia or a decrease/increase in pH. In an attempt to enhance the diagnostic accuracy of total calcium for these cases, several formulae have been developed for estimating “corrected” plasma total calcium. Although these formulae work reasonably well in normal healthy populations, they have been inadequate when applied for critically ill patients who are most prone to derangements in calcium metabolism. It has therefore been suggested that the measurement of the biologically active plasma ionized calcium be the routine rather than the exception. Ionized calcium however, has not gained widespread use for reasons that include the lack of familiarity by clinicians with the use of ionized calcium, problems historically associated with the measurement of ionized calcium, intricacies in the sample collection, and unavailability of ionized calcium measurement on the major clinical chemistry platforms. The advent of ionized calcium measurement as a standard feature in nearly all blood gas analyzers has enhanced its availability, especially in the critical care units. It is recommended that the use of ionized calcium measurement be adopted for the true reflection of calcium homeostasis in all patients.
Diagnostik und Prognostik der frühen rheumatoiden Arthritis unter besonderer Berücksichtigung der Labor-Analytik Diagnosis and prognosis of early rheumatoid arthritis, with special emphasis on laboratory analysis
Authors: Mierau Rudolf , Genth Ekkehard
Published: August 2005

Ausgehend vom klinischen Befund einer Arthritis von zwei oder mehr Gelenken wird die Diagnose einer rheumatoiden Arthritis (RA) überwiegend nach klinischen kriterien gestellt; auch die Labordiagnostik trägt jedoch wesentlich zur Frühdiagnostik der RA bei, zum einen durch die Entzündungsdiagnostik, zum anderen durch den Nachweis der RA-typischen Autoantikörper Rheumafaktor und anti-CCP. Die genannten Laborparameter haben, neben anderen Kriterien, zusätzlich zur diagnostischen auch prognostische Bedeutung im Hinblick auf Persistenz der Erkrankung, funktionelle Einbußen und radiologische Progression.
Bullöse Autoimmundermatosen Autoimmune bullous disorders
Authors: Eming Rüdiger , Hertl Michael
Published: August 2005

Bullöse Autoimmundermatosen stellen eine Gruppe organspezifischer Autoimmunerkrankungen dar, die pathogenetisch durch die Bindung von zirkulierenden Autoantikörpern an Adhäsionsstrukturen der Epidermis bzw. der dermoepidermalen Junktionszone charakterisiert sind. Die Schädigung der Integrität der jeweiligen Zielstrukturen verursacht einen Adhäsionsverlust epidermaler Keratinozyten bzw. im Bereich der Basalmembranzone, der klinisch initial als Blase und im späteren Verlauf als erosiver Substanzdefekt imponiert. Besonders Erkrankungen der Pemphigusgruppe können zu chronischen, lebensbedrohlichen Krankheitsverläufen führen. Die histologische Begutachtung läsional entnommener Hautproben ermöglicht die Lokalisation der Spaltbildung und somit eine orientierende Klassifizierung der bullösen Dermatose. Eine zentrale Bedeutung in der Diagnostik bullöser Autoimmundermatosen besitzt die Immunfluoreszenzdiagnostik, die anhand der direkten Immunfluoreszenz dem Nachweis gewebegebundener Auto-antikörper in periläsionalen Hautproben dient. Zirkulierende Autoantikörper werden an verschiedenen Gewebesubstraten, z. B. Affenösophagus oder Kochsalz-Spalthaut, nachgewiesen. Die Verfügbarkeit rekombinanter Autoantigene ermöglicht die Durchführung spezifischer ELISA-Verfahren oder Immunoblots für den Nachweis zirkulierender Autoantikörper zunächst zur Bestätigung der Diagnose im Rahmen der Primärdiagnostik und besonders auch bei der weiteren Verlaufsdiagnostik.
Protein microarrays for the diagnosis of allergic diseases: State-of-the-art and future development Protein-Biochips für die Diagnose allergischer Erkrankungen – Stand der Technik und zukünftige Entwicklungen
Authors: Harwanegg Christian , Hiller Reinhard
Published: August 2005

In the emerging field of Functional Proteomics, protein microarrays are considered to be one of the most promising tools for the simultaneous analysis of the a) abundance, b) function, and c) interaction of proteins on a system-wide scale. Resting on the technological grounds of widely used DNA biochips, the great power of microarray-based miniature solid-phase immunoassays lies in their potential to investigate in parallel large numbers of analyte pairs in a variety of biological samples. Consequently, this has fuelled aspirations that protein micro-arrays may serve as tools for the high-throughput functional investigation of complete proteomes and, moreover, that they will develop into promising candidates for innovative in-vitro diagnostic (IVD) applications. To date, published examples of protein microarrays for IVD purposes have included tests for allergy, autoimmune and infectious diseases. Here, we discuss recent advancements in the development of protein microarrays for the profiling of IgE antibodies in the diagnosis of Type 1-related allergic diseases.

Im ständig wachsenden Forschungsgebiet der funktionellen Proteomik zählen Protein-Biochips aus einer Reihe innovativer Methoden für die quantitative und funktionelle Bestimmung von Proteininteraktionen auf systemischer Ebene heute zu den aussichtsreichsten Kandidaten. Miniaturisierte Festphasen-Immunoassays, die analog zur etablierten DNA-Chip-Technologie entwickelt wurden, entfalten ihr Potential in der hoch parallelen Untersuchung unterschiedlichster Liganden-Paare in biologischem Ausgangsmaterial. Es besteht die berechtigte Hoffnung, dass Protein-Biochips in Zukunft durch den hohen Probendurchsatz und die enorme Zahl der generierten Daten den Bereich der Proteomik revolutionieren werden. Des Weiteren sind sie viel versprechende Kandidaten für neue und innovative in-vitro-Diagnostika (IVD). In mehreren aktuellen Publikationen wurde veranschaulicht, dass Protein-Biochips für die Diagnose von allergischen, autoimmunen oder infektiösen Erkrankungen wertvolle Beiträge leisten können. In diesem Artikel beleuchten wir neue Ansätze und Entwicklungen im Bereich der Diagnostik von IgE-vermittelten Typ 1-Allergien mit Hilfe von Allergen-Biochips.
Anwendung der HPLC-Tandem-Massenspektrometrie im Therapeutischen Drug Monitoring The use of HPLC-tandem mass spectrometry in therapeutic drug monitoring
Authors: Vogeser Michael
Published: August 2005

Die Flüssigkeitschromatographie-Tandem-Massenspektrometrie erlaubt erstmals die routinemäßige Anwendung der Massenspektrometrie im therapeutischen Drug-Monitoring. Vor allem durch die Möglichkeit, relativ kurzfristig hochspezifische Multianalyt-Methoden für die Messung praktisch aller Pharmaka zu entwickeln, stellt die Technik eine wesentliche Bereicherung für das Fach dar. Sie konkurriert mit den bisherigen Standardtechniken des therapeutischen Drug-Monitorings, dem Immunoassay bzw. den konventionellen HPLC-Methoden. In der vorliegenden Arbeit werden Stärken und Limitierungen der Flüssigkeitschromatographie-Tandem-Massenspektrometrie im Vergleich zu diesen Methoden diskutiert, die praktischen Anwendungscharakteristika im Routinebetrieb beschrieben und Entwicklungsperspektiven umrissen.
Monographies on drugs, which are frequently analysed in the course of Therapeutic Drug Monitoring Monographien über Medikamente, die regelmässig im Rahmen des Therapeutic Drug Monitorings analysiert werden
Authors: Rentsch K. , Fathi M. , Grignaschi N. , Magnin J.L. , Printzen G. , Thormann W. , Wenk M. , Werner D.
Published: August 2005

In 1995 the working group “Drug Monitoring” of the Swiss Society of Clinical Chemistry (SSCC) has already published a printed version of drug monographs, which are now newly compiled and presented in a standardised manner. The aim of these monographs is to give an overview on the most important informations that are necessary in order to request a drug analysis or is helpful to interpret the results. Therefore, the targeted audience are laboratory health professionals or the receivers of the reports.

There is information provided on the indication for therapeutic drug monitoring, protein binding, metabolic pathways and enzymes involved, elimination half life time and elimination routes as well as information on therapeutic or toxic concentrations.

Because preanalytical considerations are of particular importance for therapeutic drug monitoring, there is also information given at which time the determination of the drug concentration is reasonable and when steady-state concentrations are reached after changing the dose. Furthermore, the stability of the drug and its metabolite(s), respectively, after blood sampling is described.

For readers with a specific interest, references to important publications are given.

The number of the monographs will be continuously enlarged. The updated files are presented on the homepage of the SSCC (www.sscc.ch).

We hope that these monographs are helpful for you handling therapeutic drug monitoring and look forward to comments of the audience.
The Photochemistry of N‐p‐Toluenesulfonyl Peptides: The Peptide Bond as an Electron Donor
Authors: Hill Roger R. , Moore Sharon A. , Roberts David R.
Published: August 2005

The scope of photobiological processes that involve absorbers within a protein matrix may be limited by the vulnerability of the peptide group to attack by highly reactive redox centers consequent upon electronic excitation. We have explored the nature of this vulnerability by undertaking comprehensive product analyses of aqueous photolysates of 12 N‐p‐toluenesulfonyl peptides with systematically selected structures. The results indicate that degradation includes a major pathway that is initiated by intramolecular electron transfer in which the peptide bond serves as electron donor, and the data support the likelihood of a relay process in dipeptide derivatives.
Effects of Factors Related to Water Quality and Population Density on the Sensitivity of Juvenile Largemouth Bass to Mortality Induced by Viral Infection
Authors: Inendino Kate R. , Grant Emily C. , Philipp David P. , Goldberg Tony L.
Published: August 2005

Environmental stressors can predispose fish to mortality from infectious disease. This study examined the effects of two factors, water quality and physical crowding, on the responses of fish to viral infection. Juvenile largemouth bass Micropterus salmoides were experimentally inoculated with largemouth bass virus (LMBV), an emerging pathogen in the family Iridoviridae. In separate experiments, fish were exposed to various concentrations of nitrate (0, 40, 200, and 400 mg/L) and were housed at either high or low population densities. Survival time, viral load (quantity of virus in tissues), and body condition were measured as outcomes. Nitrate, as well as other water quality parameters such as ammonia, nitrite, and pH, affected mortality rates and viral loads in complex ways. Paradoxically, increased nitrate concentrations were associated with reduced mortality rates in juveniles exposed to LMBV. In general, rapid fluctuations in the concentrations of dissolved toxins had greater impact on sensitivity to viral infection than did persistently high levels of these toxins. Fish housed at high density experienced increased mortality rates, elevated viral loads, and reduced body condition compared with fish held at low density. These results demonstrate that both physiochemical and social environmental stressors can affect the survival and condition of largemouth bass infected with LMBV.
Effects of Practices Related to Catch-and-Release Angling on Mortality and Viral Transmission in Juvenile Largemouth Bass Infected with Largemouth Bass Virus
Authors: Grant Emily C. , Inendino Kate R. , Love William J. , Philipp David P. , Goldberg Tony L.
Published: August 2005

Largemouth bass virus (LMBV; family Iridoviridae) has recently emerged as a causative agent in fish kills of largemouth bass Micropterus salmoides. Little is known about how the virus is transmitted or what factors predispose fish to mortality subsequent to infection. Concern has nevertheless arisen that activities related to recreational angling may affect transmission dynamics and may alter the susceptibility of infected fish to clinical disease. This study examined the separate effects of two angling-related factors on the susceptibility of juvenile largemouth bass to mortality from LMBV infection and on the transmission of LMBV from infected to uninfected fish. The first factor was hook-and-line angling. Infected fish that underwent a simulated angling treatment did not experience higher mortality or have higher viral loads in their tissues than those that were not angled. The second factor was direct contact between infected and uninfected fish, as would occur in live wells and holding tanks. The LMBV was transmitted from infected to uninfected fish through water, even when direct contact was prevented. Transmission of LMBV between infected and uninfected fish separated by a fenestrated barrier was nearly as efficient as LMBV transmission between infected and uninfected fish that were allowed direct contact. These results imply that angling itself may have only minimal effects on the survival of largemouth bass infected with LMBV but that angling-related practices that place infected and uninfected fish together in a limited water volume may facilitate viral transmission. Partitioning or cooling of live wells and holding tanks, as well as limiting their use, could reduce LMBV-associated mortality and viral transmission.
Toxicity of herbicides in highway runoff
Authors: Huang Xinjiang , Fong Stephanie , Deanovic Linda , Young Thomas M.
Published: August 2005

Previous field monitoring at two highway sites found highway-applied herbicides in storm water runoff at maximum concentrations ranging from 10 μg/L for glyphosate and diuron to as high as 200 μg/L for oryzalin. To determine whether these herbicides at these concentrations can cause any toxicity to aquatic organisms, a standard toxicity study was conducted. Storm water was collected along Highway 37, Sonoma County, California, USA, and the herbicides isoxaben, oryzalin, diuron, clopyralid, and glyphosate were spiked into the storm water at the highest concentrations observed during the five previous field-monitoring campaigns. Three different toxicity studies were conducted and the results showed the following: No significant reduction in reproduction or increase in mortality relative to the control for an 8-d Ceriodaphnia (water flea) toxicity test; no significant increase in mortality or decrease in biomass compared to the control during a 7-d Pimephales (fish) toxicity test; and, in a 96-h Selenastrum (algae) toxicity test, both the 10-μg/L diuron treatment and the combined 50-μg/L isoxaben plus 200-μg/L oryzalin treatment produced significant (p < 0.05) reductions in algal growth compared to the controls, although the 30-μg/L clopyralid or 10-μg/L glyphosate treatments did not exhibit any toxic effects.
Short-term sublethal (sediment and aquatic roots of floating macrophytes) assays with a tropical chironomid based on postexposure feeding and biomarkers
Authors: Moreira-Santos Matilde , Fonseca Ana L. , Moreira Susana M. , Rendón-von Osten Jaime , da Silva Eduardo M. , Soares Amadeu M. V. M. , Guilhermino Lúcia , Ribeiro Rui
Published: August 2005

This study proposes assays with a freshwater chironomid, Chironomus xanthus, distributed over South America, based on subindividual (acetylcholinesterase activity) and individual (survival and postexposure feeding) level endpoints. Sediment and aquatic-rooted floating macrophyte assays were developed, due to the importance of both substrates for toxicant exposure in subtropical/tropical environments. Assays were evaluated under realistic exposure scenarios by simulating a runoff over an agricultural field dosed with deltamethrin. In situ assays were performed within microcosms to discriminate the effects of deltamethrin from those of additional potential stress factors (organism handling and caging, microcosms, use of aquatic roots, and runoff per se). A laboratory sediment assay based on feeding was conducted with samples from the microcosms. In all assays, both sublethal endpoints were responsive to deltamethrin and more sensitive than survival. Survival and feeding were more sensitive in situ than in the laboratory. In the in situ sediment assays, both sublethal endpoints were within a similar range of sensitivity; they were significantly inhibited as of the lowest Decis dose, from approximately 20 to 70%. In situ feeding was more sensitive in the sediment than in the macrophyte assay, where it was inhibited significantly only at the two highest Decis doses (up to ˜60%). Larval performance was not influenced significantly by any of the other potential stress factors.
Aeration with carbon dioxide-supplemented air as a method to control pH drift in toxicity tests with effluents from wastewater treatment plants
Authors: Elphick James R. , Bailey Howard C. , Hindle Amanda , Bertold Stanley E.
Published: August 2005

Environment Canada methods for acute toxicity tests with rainbow trout require continuous aeration of test solutions during exposure. Depending on the sample, this procedure can result in an increase in pH as dissolved carbon dioxide (CO2) is stripped from solution as a result of aeration. In samples that contain ammonia, the pH may increase to the point where the unionized fraction results in artifactual toxicity. Consequently, aeration with air supplemented with different CO2 concentrations was investigated as a method for maintaining pH at the level found in the original sample without adversely affecting other water quality parameters. Aeration with CO2 was an effective method for maintaining pH during exposure, depending both on the concentration of CO2 and the alkalinity of the sample. A multiple regression conducted on the data determined an equation that was effective at calculating the CO2 concentration necessary in an aeration mixture to maintain a target pH value as a function of sample alkalinity.
Developmental effects of bioaccumulated selenium in eggs and larvae of two salmonid species
Authors: Holm Jodi , Palace Vince , Siwik Paula , Sterling George , Evans Robert , Baron Christopher , Werner Julieta , Wautier Kerry
Published: August 2005

Elevated concentrations of Se have been detected in cold, flowing water habitats near uranium and coal mines in Canada. Fish from these systems have concentrations of Se in their tissues that exceed toxic effect thresholds that have been established for warm-water fishes. However, the applicability of toxic effect thresholds and guidelines to cold water, lotic habitats is a matter of contention in the literature since most cases of Se toxicosis have been documented in standing, warm-water systems. To examine the possibility of impaired reproduction in wild rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) near coal mining activity in the northeastern slopes region of Alberta, Canada, spawn from both species were collected from exposure and reference sites. Gametes were fertilized in the laboratory, reared to the swim-up stage, and examined for deformities. A significant relationship was observed for rainbow trout between the amount of Se in eggs and the incidence of developmental abnormalities, specifically craniofacial defects, skeletal deformities, and edema. These associations approximate exponential functions with probabilities that 15% of the population would be affected occurring between 8.8 and 10.5 μg Se per gram of wet egg weight, based on probit analysis. These relationships are similar to those described for centrarchids inhabiting a seleniferous warm-water lake. No such relationships were established for brook trout.
Sorption of hydrophobic organic chemicals to bacteria
Authors: Lunsman Tamara D. , Lick Wilbert
Published: August 2005

The toxicity and time-dependent sorption of three hydrophobic organic chemicals to Rhodococcus rhodochrous bacteria were investigated. In experiments, environmentally relevant concentrations of pentachlorophenol (PCP), hexachlorobenzene (HCB), and dichlorobiphenyl (DPCB) were applied to living (both growing and nongrowing) bacteria as well as to dead bacteria. For PCP (an ionizing chemical), bacterial growth decreased, and bacterial death increased, as the PCP concentration increased. In sorption experiments with PCP, the partition coefficient was affected by the active uptake of PCP by living but not by dead bacteria, by the death of the living bacteria because of PCP toxicity, and by saturation of site-specific sorption as the PCP concentration increased. Hexachlorobenzene (a nonionizing chemical) did not affect bacterial growth or death at all HCB concentrations investigated. In sorption experiments with HCB, the partition coefficient depended on the rate of bacterial growth relative to the sorption rate. The sorption rate depended on the state of bacterial aggregation, and this changed with time. Results for DPCB (a nonionizing chemical with an equilibrium partition coefficient similar to that of HCB) were similar to those for HCB.
Assessment of contaminated sediments with an indoor freshwater/sediment microcosm assay
Authors: Triffault-Bouchet Gaëlle , Clément Bernard , Blake Gérard
Published: August 2005

This study was conducted to assess the feasibility of using a 2-L, indoor microcosm assay to evaluate five contaminated sediments (A, B, C, D, and E). Toxic potential was deduced in the light of general contamination of sediments, pollutant partitioning in microcosms, and biological responses of species (Pseudokirchneriella subcapitata, Lemna minor, Daphnia magna, Hyalella azteca, Chironomus riparius): E<A<B<C<D. Sediments mainly were contaminated by metals (lead and zinc). Organic pollutant contents varied among the sediments. The major polycyclic aromatic hydrocarbon (PAH) compounds were pyrene, fluoranthene, and phenanthrene. Sediments A, B, and C highly stimulated duckweed growth (<700%) and impaired daphnid (<20%) and amphipod survival (<30%). Sediment D had no significant effect on pelagic and benthic organisms. Finally, sediment E, the most toxic, limited duckweed growth (inhibition of 82%) and impaired daphnid survival (0% of survival). Amphipods were impaired dramatically by this sediment (0% of survival), in contrast with chironomids, for which no toxic effect was measured. The 2-L, indoor microcosm assay successfully was applied to the assessment of those five contaminated sediments. Sediments A, B, C, and E should not be deposited in gravel quarries, and new, more sensitive endpoint measurements should be developed.
Physicochemical characterization of coke-plant soil for the assessment of polycyclic aromatic hydrocarbon availability and the feasibility of phytoremediation
Authors: Ahn Sungwoo , Werner David , Luthy Richard G.
Published: August 2005

Coke oven site soil was characterized to assess the particle association and availability of polycyclic aromatic hydrocarbons (PAHs). We identified various carbonaceous materials including coal, coke, pitch, and tar decanter sludge. Most of the PAHs were associated with the polymeric matrix of tar sludge or hard pitch as discrete particles, coatings on soil mineral particles, or complex aggregates. The PAH availability from these particles was very low due to hindered diffusive release from solid tar or pitch with apparent diffusivities of 6 × 10−15 for phenanthrene, 3 × 10−15 for pyrene, and 1 × 10−15 cm2/s for benzo[a]pyrene. Significant concentrations of PAHs were observed in the interior of solid tar aggregates with up to 40,000 mg/kg total PAHs. The release of PAHs from the interior of such particles requires diffusion over a substantial distance, and semipermeable membrane device tests confirmed a very limited availability of PAHs. These findings explain the results from three years of phytoremediation of the site soil, for which no significant changes in the total PAH concentrations were observed in the test plot samples. The observed low bioavailability of PAHs probably inhibited PAH phytoremediation, as diffusion-limited mass transfer would limit the release of PAHs to the aqueous phase.
Modeling of cadmium bioaccumulation in two populations of the green mussel Perna viridis
Authors: Ng Tania Y.-T. , Wang Wen-Xiong
Published: August 2005

This study attempted to quantify differences in Cd biokinetics from two populations of green mussels (Perna viridis) from two sites (eastern and western) in Hong Kong with contrasting hydrological conditions. Body Cd concentrations were modeled using a simple biokinetic model coupled with measurements of dissolved Cd concentrations at each site. Mussels collected from the western site had three to six times higher Cd tissue concentration than the eastern population collected during two seasons (summer wet and winter dry), but the salinity was only lower in the western site during the summer. More Cd was distributed in the metallothionein-like and heat-sensitive proteins in the western population than the eastern population, and Cd predominantly was distributed in the insoluble fraction during summer. The Cd uptake rate constant from the dissolved phase was higher in the western population during summer due to a much lower salinity, but was comparable during winter. Dietary uptake of Cd was similar in both populations, and assimilation was lower from ingested radiolabeled seston than from diatoms. Efflux of Cd remained comparable between the two populations from two seasons (0.02–0.03/d). Kinetic modeling demonstrates that the faster influx of Cd from aqueous phase caused the higher body Cd concentrations in the western population. The predicted Cd concentrations in mussels were comparable to those observed in the field. Our study highlights differences in Cd accumulation kinetics in different populations of mussels likely caused by the different physical environments.
Reproductive and developmental toxicity and bioconcentration of perfluorooctanesulfonate in a partial life-cycle test with the fathead minnow (Pimephales promelas)
Authors: Ankley Gerald T. , Kuehl Douglas W. , Kahl Michael D. , Jensen Kathleen M. , Linnum Ann , Leino Richard L. , Villeneuve Dan A.
Published: August 2005

Perfluorooctanesulfonate (PFOS) is a widespread environmental contaminant emanating from the production and/or metabolism of fluorinated chemicals with a variety of applications. The goal of this work was to assess the toxicity and bioconcentration of PFOS in the fathead minnow (Pimephales promelas). Sexually mature fish were exposed via the water for 21 d to 0 (control), 0.03, 0.1, 0.3, or 1 mg PFOS/L, and effects on reproductive capacity and endocrinology were assessed. To determine possible developmental effects, a subset of embryos from parental exposures at each test concentration were held for an additional 24 d in the same PFOS treatments. A concentration of 1 mg PFOS/L was lethal to adults within two weeks. The 21-d 50% effect concentration (95% confidence interval) for effects on fecundity of the fish was 0.23 (0.19–0.25) mg PFOS/L. Exposure to PFOS caused various histopathological alterations, most prominently in ovaries of adult females. Adult males exposed to 0.3 mg PFOS/L for 21 d exhibited decreased aromatase activity and elevated concentrations of plasma 11-ketotestosterone and testosterone. No significant adverse effects on survival or growth were observed in developing fathead minnows held for 24 d at PFOS concentrations up to 0.3 mg/L. Adult fathead minnows readily accumulated PFOS from the water. The largest concentrations of PFOS were in blood, followed by liver and then gonad; for all tissues, females accumulated higher concentrations than males. Water and tissue concentrations of PFOS associated with effects in this study exceeded those reported for samples collected from the field by two to three orders of magnitude, suggesting that the current risk of PFOS on aspects offish reproduction and development assessed in this study would be small.
Electron paramagnetic resonance investigation of in vivo free radical formation and oxidative stress induced by 2,4-dichlorophenol in the freshwater fish Carassius auratus
Authors: Luo Yi , Wang Xiao-Rong , Shi Hua-Hong , Mao Da-qing , Sui Yun-Xia , Ji Liang-Liang
Published: August 2005

In the present study, electron paramagnetic resonance coupled with spin-trapping technique was used, with α-phenyl-N-tert-butylnitrone (PBN) as a spin-trapping agent, to investigate free radical generation in freshwater fish with acute 2,4-dichlorophenol (2,4-DCP) poisoning. The PBN-radical adducts were detected in fish liver samples following treatments of 2,4-DCP (0.025, 0.05, 0.5, 5, or 25 mg/kg) 24 h after intraperitoneal (i.p.) injection and 2,4-DCP (0.5 mg/kg) at 2, 4, 8, 24, or 72 h after i.p. injection in Carassius auratus. The hyperfine splitting constants for the PBN-radical adducts are aN = 13.7 G, aH = 1.8 G, and g = 2.0058, which is consistent with those of PBN/hydroxyl radical (·OH). The results indicate that the hydroxyl radical is probably produced during acute intoxication of 2,4-DCP. The relative similarity in the kinetics (from 2 to 72 h) of superoxide dismutase activity induction and ·OH generation implies that the generation of ·OH possibly depends on the superoxide anion (O.−2). Superoxide anion (O.−2) might be the precursor radical undergoing the Haber-Weiss reaction to form ·OH. Possible pathways for radical chain reactions in the formation of the hydroxyl radical in vivo after 2,4-DCP administration are proposed. Other parameters with respect to antioxidant defense (e.g., superoxide dismutase and catalase) and oxidative damage (lipid peroxidation level) indicate that the fish were subjected to oxidative stress induced by 2,4-DCP and that the mechanisms of oxidative stress possibly involve the in vivo stimulation of hydroxyl radical formation.
Microbial responses to zinc in soil microcosms with and without a natural assemblage of enchytraeids
Authors: Kools Stefan A. E. , Ferwerda Bart , van Gestel Cornelis A. M. , van Straalen Nico M.
Published: August 2005

The presence of higher trophic levels in studies on the toxicity on soil contaminants to microbial processes increases ecological realism. This study assessed the toxicity of zinc to soil microbial processes in the presence and absence of enchytraeids (Oligochaeta, Annelida). We incubated microcosms under standard conditions without or inoculated with a natural assemblage of enchytraeid species. Total zinc concentrations of 365 to 1,360 mg/kg caused no mortality of enchytraeids during six weeks' incubation. Soil nitrate concentrations showed a negative trend under zinc addition and soil ammonium concentrations were the highest at zinc concentrations of 1,360 mg/kg, indicating impairment of ammonium oxidation. Zinc decreased bacterial carbon biomass and caused a dose-response decrease of the respiration, but this was not observed in the presence of enchytraeids. Respiration, ammonium concentrations, and soil moisture contents were increased by enchytraeids. We observed no interaction between the addition of zinc and the presence of enchytraeids. The effect of enchytraeids on soil-moisture contents and microbial processes, and the importance of enchytraeid-microbial interactions are discussed.
Promotion of Physical Activity Among High-School Girls: A Randomized Controlled Trial
Authors: Pate Russell R. , Ward Dianne S. , Saunders Ruth P. , Felton Gwen , Dishman Rod K. , Dowda Marsha
Published: August 2005

Objectives. Many adolescent girls fail to meet national guidelines for physical activity, and the prevalence of obesity is increasing among this group. Our study examined the effects of a comprehensive school-based intervention on physical activity among high-school girls.

Methods. A group-randomized controlled field trial was conducted at 24 high schools. A school-based sample of 2744 girls (48.7% African American, 46.7% White) participated in a measurement protocol when they were in eighth and then ninth grade. A comprehensive physical activity intervention was designed to change the instructional program and the school environment to increase support for physical activity among girls.

Results. At follow-up, 45% of girls in the intervention schools and 36% of girls in the control schools reported vigorous physical activity during an average of 1 or more 30-minute time blocks per day over a 3-day period.

Conclusions. A comprehensive school-based intervention can increase regular participation in vigorous physical activity among high-school girls.
Clustering of Fast-Food Restaurants Around Schools: A Novel Application of Spatial Statistics to the Study of Food Environments
Authors: Austin S. Bryn , Melly Steven J. , Sanchez Brisa N. , Patel Aarti , Buka Stephen , Gortmaker Steven L.
Published: August 2005

Objectives. We examined the concentration of fast food restaurants in areas proximal to schools to characterize school neighborhood food environments.

Methods. We used geocoded databases of restaurant and school addresses to examine locational patterns of fast‐food restaurants and kindergartens and primary and secondary schools in Chicago. We used the bivariate K function statistical method to quantify the degree of clustering (spatial dependence) of fast-food restaurants around school locations.

Results. The median distance from any school in Chicago to the nearest fast-food restaurant was 0.52 km, a distance that an adult can walk in little more than 5 minutes, and 78% of schools had at least 1 fast-food restaurant within 800 m. Fast-food restaurants were statistically significantly clustered in areas within a short walking distance from schools, with an estimated 3 to 4 times as many fast-food restaurants within 1.5 km from schools than would be expected if the restaurants were distributed throughout the city in a way unrelated to school locations.

Conclusions. Fast-food restaurants are concentrated within a short walking distance from schools, exposing children to poor-quality food environments in their school neighborhoods.
Beryllium
Authors: Mroz Margaret M. , Balkissoon Ronald , Newman Lee S.
Published: August 2005

Beryllium, found in a variety of different forms, has become indispensable in modern high‐technology industries, especially aerospace. It has many attractive properties, including light weight, high strength, and heat resistance. Unfortunately, beryllium is associated with a number of toxic effects. Even under controlled conditions, beryllium metal, oxide, and alloys can cause chronic lung disease among individuals exposed to dust or fume.

Identifying properties of different forms of beryllium are listed in Sections the first followed by sections, which describe the properties and characteristics of beryllium per se. These include production and use, toxic effects, standard and exposure assessment.
Zinc and Cadmium
Authors: Jakubowski Marek
Published: August 2005

This article covered zinc, zinc compounds, cadmium and cadmium in details in the following categories: physical and chemical properties, production, use, toxic effects, environmental impacts, and exposure assessment.
Aluminum
Authors: Dinman Bertram D.
Published: August 2005

Because of this element's electrochemical properties, its positvely charged ions form very tight chemical bonds with other anions such that dissociation is minimal in neutral or near‐neutral‐pH environments. Since most living organizations operate at or about such pH levels, by implication most naturally occurring aluminum compounds would display minimal potentials for cellular or subcellular interactions. Its binding forces, in addition to making this element available only recently (at the time of writing), has also meant that aluminum was relatively unavailable to the milieu intériur. However, since progressively more of the metal and its compounds came into common human use and commerce, ultimately its wide usage could be expected to eventually result in the possibility intimate human contact and finally, human health and hazard concerns.

These events have indeed occurred so that aluminum and its possible association with neurological disorders became a prominent health issue of the late twentieth century. Because of the foregoing electrochemical physical realities, concerns have focused on theelement'shealth effects per se, with little or attention directed at effects of aluminum compounds, such as chloride, phosphate, and sulfates. This should also not be unexpected, given theirrelativebiological inavailability. Obviously, some aluminum compounds do ionize sufficient to lower pH in aqueous environments (e.g., aluminum chloride or phosphate) and act as simple irritants. However, most other aluminum compounds, as expected have had very littleapparentbiologic availability or effects, and thus are accorded little scientific attention as compounds per se.

These facts are reflected in the content of contemporary biomedical literature. Although multiple aluminum compounds have been studied, few, if any, are studied except as they serve to “transport” aluminum into the body. The overwhelming majority represent interest in aluminum's effects alone rather than an individual compound's possible bioimpact.

For these reasons, this chapter deals mainly with aluminum as an element and the most common prevalent form: the oxides. Since its other compounds as such are the subject of so little current investigation, these other compounds are considered separately later in this chapter.
Aliphatic and Alicyclic Amines
Authors: Cavender Finis L.
Published: August 2005

Aliphatic and alicyclic amines are nonaromatic amines that have a straight chain, a branched chain, or a cyclic alkyl moiety attached to the nitrogen atom.

Aliphatic amines are highly alkaline and tend to be fat soluble. As such, they have the potential to produce severe irritation to skin, eyes, and mucous membranes. Corrosive burns as well as marked allergic sensitization may also occur. Volatile amines, which are characterized by boiling points lower than 100°C, are highly irritating and include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine,n‐propylamine, isopropylamine, diisopropylamine, allylamine,n‐butylamine, isobutylamine,sec‐butylamine,tert‐butylamine, and dimethylbutylamine. Workplace practice must consider these properties in developing strategies to protect workers. Toxicity information in humans continues to be limited. Although great strides in understanding the process of carcinogenicity have been made in recent years, controversies regarding potential aliphatic amine carcinogenicity are far from being resolved. Of considerable interest is the possibility of nitrosamine formation, which is both compound specific and pH dependent.
Acetone
Authors: Morgott David A.
Published: August 2005

Acetone is a clear, colorless liquid that is highly flammable and infinitely soluble in water. Years of clinical study, laboratory testing, and practical experience have shown that acetone can be used safely and without harm in many industrial and commercial applications. The long‐standing interest in the biochemical, pharmacological, and toxicological properties of acetone can be traced to three important characteristics of the chemical:

Acetone is a normal by‐product of mammalian metabolism; levels within the body can, however, be altered by changes in nutrition or energy balance.

Acetone is a highly volatile organic solvent that is miscible with water; thus large amounts of the vapor can be absorbed through the lungs and quickly distributed throughout the body.

Acetone is manufactured and used in large amounts in a variety of commercial and industrial applications; thus the potential for exogenous human exposure is widespread.
Ketones of Six To Thirteen Carbons
Authors: Topping Douglas C. , Morgott David A. , O'Donoghue John L.
Published: August 2005

Ketones of carbon number 6–13 are important commercial and industrial materials. Their primary use is as solvents that find use in numerous products and industrial applications. Due to their volatility, environmental regulations have been directed at restricting emissions, particularly to the atmosphere. A number of the ketones discussed in this chapter can undergo photochemical transformations that contribute to their abiotic degradation but may also contribute to the formation of smog. Regulations limiting or prohibiting release of materials that may contribute to smog formation are leading to reductions in the use of some of these materials.

As for the short‐chain ketones discussed in Chapter 75, the ketones covered in this chapter are mainly of concern due to inhalation and dermal exposure routes. Acute exposure to high vapor concentrations of these materials may result in narcosis; however, such exposures are rare except in cases of accidents.

Low levels of exposure to many of these ketones can be expected in the environment and through endogenous exposure because ketones are common substrates for many of the enzymes associated with intermediary metabolism in organisms from bacteria to man.
Esters of Carbonic and Orthocarbonic Acid, Organic Phosphorous, Monocarboxylic Halogenated Acids, Haloalcohols, and Organic Silicon
Authors: Bisesi Michael S.
Published: August 2005

This chapter covers (1) esters of carbonic and orthocarbonic acid, (2) esters of organic phosphorous compounds, (3) esters of monocarboxylic halogenated acids, alkanols, or haloalcohols, and (4) organic silicon esters. Other classes of esters are summarized in Chapters 79 and 80. Refer to the Introduction in Chapter 79 for a more detailed overview of general properties of esters.

Unfortunately, as shown in the two prior chapters, mainly fragmented toxicological evaluations are available for esters. Most of these esters are characterized by low toxicity. Indeed, as expressed in Chapter 79, lethal dose (e.g., LD50) values are frequently difficult or impractical to measure. Localized dermal irritation is one common effect characteristic of exposures to most organic solvents. Few esters are readily absorbed, but there are exceptions, such as tri‐o‐cresyl phosphate (TOCP). Several of the halogenated derivatives, such as ethylchloro‐ and ethylbromo‐, are potent lacrimators. Ethyl fluoroacetate and fluoroacetic acid exhibit about the same mode of action, which may indicate that the acetate is rapidly hydrolyzed and metabolized in the mammalian system. The unsaturated carbonates are also associated with high lacrimatory activity.

TOCP is an example of an ester that can cause neuropathy in a variety of animal species. The initial weakness and paralysis are normally reversible in early stages, but repeated or massive assaults result in demyelination of the nerve fibers. The mechanism of action is not yet certain, but it appears to involve phosphorylation of proteins. Only selected phosphates exhibit neuropathic effects, including diisopropyl fluorophosphorate andN,N′‐diisopropyl phosphorodiamidic fluoride.

As was expressed in Chapter 79, industrial hygiene evaluation of esters involves collecting and analyzing air samples to determine their airborne concentrations. Published industrial hygiene air sampling and analytical methods, however, are unavailable for most esters. In relation, there are few occupational exposure and biological limits. A list of ester compounds covered in this chapter that have industrial hygiene sampling and analytical methods are presented here along with their respective occupational exposure limits, established by the American Conference of Governmental Industrial Hygienists (ACGIH), the Occupational Safety and Health Administration (OSHA), and the National Institute for Occupational Safety and Health (NIOSH). As stated in Chapter 79, since sampling and analytical methods and occupational exposure limits are subject to periodic revision, the reader is encouraged to refer to current publications of ACGIH, OSHA, and NIOSH.
Noise and Ultrasound
Authors: Clark William W.
Published: August 2005

Noise is America's most widespread nuisance. But excessive noise is more than just a nuisance. Day and night, at home or at work or play, excessive noise exposure annoys individuals, produces stress, impairs the ability to communicate, interferes with work and play activities, and, in high enough doses, produces permanent damage to the auditory system that can lead to significant hearing loss.

Although annoyance caused by noise affects all of us to some degree, this chapter describes the effects of excessive noise on hearing, and on the effects of ultrasonic stimulation on tissue. The chapter is organized in four sections. In the first, consideration is given to the physical characteristics of sound and the measurement of noise exposure. The second section considers the effects of excessive noise exposure within the range of human hearing, approximately 20 hertz (Hz) to 20 kilohertz (kHz). In the third section, a review of the effects of infrasonic exposure (<20 Hz) is provided. Finally, the last section reviews the effects of exposure to ultrasound (20 kHz to 20 MHz) on humans.

Engineers and scientists are concerned with sound as an energy that can be measured and quantified; no consideration is usually given to whether the sound can be perceived by humans or not. However, hearing health professionals are usually concerned about theeffectsof sound on humans: what and how we hear, what sounds please us, what sounds annoy us, what sounds interfere with our ability to communicate with each other, and what sounds can be damaging to our hearing. These definitions are necessarily more complex than “simple” quantitative descriptions of acoustic energy, and often are expressed in perceptual terms, like “loudness” or “pitch.”