bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorous Solvents
Authors: Ryu Ilhyong , Matsubara Hiroshi , Emnet Charlotte , Gladysz John A. , Takeuchi Seiji , Nakamura Yutaka , Curran Dennis P.
Published: October 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Catalysis with Nitrides and Oxynitrides
Authors: Hargreaves J. S. J. , Mckay D.
Published: October 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Domain Relationships in Thiamine Diphosphate‐Dependent Ezymes
Authors: Duggleby Ronald G.
Published: October 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Significant impact of cutaneous T‐cell lymphoma on patients' quality of life
Authors: Demierre Marie‐France , Gan Stephanie , Jones Judy , Miller Donald R.
Published: October 2006

BACKGROUND.

Cutaneous T‐cell lymphoma (CTCL) can have a profound impact on a patient's health‐related quality of life; however, little is known about its actual impact. The authors evaluated patients' perspectives on the impact of CTCL on physical functioning, lifestyle, emotional well being, and satisfaction with treatment.

METHODS.

A 4‐page, self‐administered questionnaire was mailed and made available online in March 2005 to the entire United States membership of the Mycosis Fungoides Foundation (n = 930 members). Outcome measures were patients' perspectives on the psychosocial impact of CTCL and the management of their disease.

RESULTS.

The response rate was 68%, and 93.6% of respondents were white. The majority of respondents had mycosis fungoides (89%). Respondents were bothered by skin redness (94%) and by the extent of symptoms that affected their choice of clothing (63%). For most patients, the disease had a functional impact, rendering them tired or affecting their sleep. Health distress was reported by almost all respondents, with 94% reporting that they worried about the seriousness of their disease and 80% worrying about dying from the disease. Sixty‐two percent of respondents reported that their disease made them feel unattractive, 85% reported that their treatment made their disease seem more manageable, but 61% reported that they felt burdened financially by their disease.

CONCLUSIONS.

The high response rate and patients' responses to the survey provided compelling evidence that patients believed CTCL had a profound and severe impact on their functioning, emotional, and social well being. A striking health distress was prevalent in almost all respondents. Although the majority of patients reported that treatments made their disease more manageable, a significant proportion reported that they felt burdened financially by their disease. Cancer 2006. © 2006 American Cancer Society.
Degeneration and regeneration of ultraviolet cone photoreceptors during development in rainbow trout
Authors: Allison W. Ted , Dann Stephen G. , Veldhoen Kathy M. , Hawryshyn Craig W.
Published: October 2006

Ultraviolet‐sensitive (UVS) cones disappear from the retina of salmonid fishes during a metamorphosis that prepares them for deeper/marine waters. UVS cones subsequently reappear in the retina near sexual maturation and the return migration to natal streams. Cellular mechanisms of this UVS cone ontogeny were investigated using electroretinograms, in situ hybridization, and immunohistochemistry against opsins during and after thyroid hormone (TH) treatments of rainbow trout (Oncorhynchus mykiss). Increasing TH levels led to UVS cone degeneration. Labeling demonstrated that UVS cone degeneration occurs via programmed cell death and caspase inhibitors can inhibit this death. After the cessation of TH treatment, UVS cones regenerated in the retina. Bromodeoxyuridine (BrdU) was applied after the termination of TH treatment and was detected in the nuclei of cells expressing UVS opsin. BrdU was found in UVS cones but not other cone types. The most parsimonious explanation for the data is that UVS cones degenerated and UVS cones were regenerated from intrinsic retinal progenitor cells. Regenerating UVS cones were functionally integrated such that they were able to elicit electrical responses from second‐order neurons. This is the first report of cones regenerating during natural development. Both the death and regeneration of cones in retinae represent novel mechanisms for tuning visual systems to new visual tasks or environments. J. Comp. Neurol. 499:702–715, 2006. © 2006 Wiley‐Liss, Inc.
Jet‐Assisted Aerosol CVD for Multicomponent Particle Deposition
Authors: Hong C. , Kim D. S. , Choi M.
Published: October 2006

Aerosol CVD has been extensively utilized to manufacture high‐quality optical fibers in which multicomponent aerosols are generated and deposited. Our earlier study proposed a jet‐assisted aerosol CVD in which high‐temperature internal jets were used inside a conventional silica tube reactor of a modified (M)CVD method, and showed the enhancement of deposition performance for single component SiO2 particle deposition. In the present study, we apply this method to the deposition of multicomponent particles and demonstrate that our method of jet‐assisted aerosol CVD not only significantly improves overall particle deposition efficiency, but also enhances the uniformity of composition of multicomponent SiO2/GeO2 particle deposition. The existence of an optimum jet flow rate for the maximum deposition efficiency has been found. A nitrogen jet has also been used and found to produce almost the same improvement for particle deposition performance as in the case of a helium gas jet.
Crystal Growth of ZnS Films by a Charged Aerosol‐Assisted Vapor Deposition Process
Authors: Hou X. , Choy K.‐L.
Published: October 2006

Zinc sulfide (ZnS) films have promising applications in optoelectronic devices. The crystal structures and textures of ZnS films depend on the fabrication method and their processing conditions. This paper reports the crystal growth of hexagonal ZnS films deposited using a charged, aerosol‐assisted, vapor deposition method. The effects of the charge of precursor droplets on the crystallinity, composition, morphology, and optical bandgap of ZnS films have been established. The crystallographic and morphological results reveal that appropriate droplets charge density can enhance the crystallinity and preferred growth orientation of the hexagonal ZnS structure. The possible deposition mechanism is also discussed.
An instrument for sorting of magnetic microparticles in a magnetic field gradient
Authors: Espy Michelle A. , Sandin Henrik , Carr Chris , Hanson Christina J. , Ward Michael D. , Kraus Robert H.
Published: October 2006

Background:

The goal of our bioassay technique is to demonstrate high throughput, highly parallel, and high sensitivity quantitative molecular analysis that will expand current biomedical research capabilities. To this end, we have built and characterized a magnetophoresis instrument using a flow chamber in a magnetic field gradient to sort magnetic microparticles by their magnetic moment for eventual use as biological labels.

Methods:

The flow chamber consists of a sample inlet, differential sheath streams, and eight outlets for collecting the microparticles after they have traversed the chamber. Magnetic microparticles are injected into the flow chamber that is positioned in a linear magnetic field gradient. The trajectory for each microparticle is determined by its total magnetic moment and size. The resulting populations of monodispersed magnetic microparticles in the different outlet bins are sorted by their magnetic moment; with the highest magnetic moments being deflected the furthest.

Results:

We have characterized the system for sorting both superparamagnetic and ferromagnetic microparticles with approximate diameters of 8 μm and 4.0–4.9 μm, respectively. To characterize the instrument, we used microparticles with a known size distribution and varied the transit time through the chamber. This is equivalent to varying the magnetic moment, while allowing us to hold the particle properties constant from run‐to‐run. We demonstrated the ability to reproducibly change the distribution of the particles in the collection bins by varying transit time in good agreement with theory. We identified hydrodynamic instabilities responsible for causing dispersion in the flow. Improvements to the flow chamber hydrodynamics such as reducing the aspect ratio between the sample inlet and the chamber depth and stabilizing the sheath flow resulted in narrow sorting distributions. We measured a sorting reproducibility (percentage of particles returning to their original bin upon resorting individual populations) of 84–89%.

Conclusions:

We have developed a simple magnetophoresis system for reproducibly sorting magnetic microparticles. This technique will permit the use of microparticles with a wide range of magnetic moments to create a wide range of magnetic labels. Careful consideration of system design and operational parameters enables reliable and reproducible sorting of microparticles with varying size and magnetic content. © 2006 International Society for Analytical Cytology
Comparative analysis of ZAP‐70 expression and Ig VH mutational status in B‐cell chronic lymphocytic leukemia
Authors: Muñoz Luz , Lasa Adriana , Carricondo Maria T. , Hernández Carmen , Ubeda Josep , Nomdedéu Josep F.
Published: October 2006

Background:

B‐cell chronic lymphocytic leukemia (CLL) is a heterogeneous disorder with respect to its clinical course. Accurate identification of prognostic factors is becoming increasingly important in order to determine those patients requiring aggressive treatments. Two of the most predictive outcome markers are the Ig VH mutational gene status and ZAP‐70 expression. In earlier reports, both parameters have shown a high degree of concordance. To assess the value of these determinations in clinical practice, we simultaneously analyzed Ig VH mutations and ZAP‐70 expression in a consecutive series of B‐CLL.

Methods:

Fifty‐three consecutive B‐CLL cases were included in the study. ZAP‐70 expression was investigated by flow cytometry. Positivity was established using two methods: comparing ZAP70 expression in B‐cells with T‐cells using cytoplasmic CD3 (ZAP‐70/T) and with NK‐cell reactivity (ZAP‐70/NK). The complete immunophenotype was recorded in each case. Ig VH mutational gene status was determined employing purified RNA from peripheral blood samples. Retrotranscribed DNA was PCR‐amplified, direct‐sequenced, and compared with available public databases. VH3.21 family use was also recorded.

Results:

Using a T‐cell marker, 58% of patients were ZAP‐70+ and 42% were ZAP‐70−. NK‐cell comparisons gave only 6% of ZAP‐70 positivity in B‐CLL, and in six cases the absence of a clearly defined NK‐cell population precluded the ZAP70 analysis. Twenty‐four (45%) patients had mutated Ig VH genes and 29 (55%) had unmutated Ig VH genes. The results showed a statistical association between ZAP‐70/T expression and VH mutational status. Despite this, in 30% of cases there was a discordant result.

Immunophenotypic analysis showed no major differences in Matutes'score between mutated and nonmutated cases. Only FMC7 was more commonly expressed in the unmutated B‐CLL cases. VH3.21 was present in 7.5% of cases, mostly having an unmutated pattern.

Conclusions:

ZAP‐70 reactivity using a T‐cell marker as a control allows to identify the majority of patients with an unmutated Ig VH genotype. Parallel analysis revealed that discordances with Ig VH analysis are quite common with currently employed flow cytometry reagents and techniques. © 2006 International Society for Analytical Cytology
EU‐Forschungsprojekt ESECMaSE – Teilprojekt Optimierung von Hochlochziegeln für Aussteifungswände
Authors: Meyer Udo , Roßbach Michael , Schermer Detleff
Published: October 2006

Unbewehrtes Ziegelmauerwerk hat sich in den letzten Jahrhunderten als geeigneter Baustoff in den mitteleuropäischen Erdbebenzonen bewährt. Erhöhte Anforderungen aus den Lastnormen waren der Anlaß für umfangreiche Untersuchungen zur Schubtragfähigkeit von Mauerwerk. Die Optimierung von Produkteigenschaften von Hochlochziegeln für schubbeanspruchtes Mauerwerk war dabei einer von mehreren Untersuchungsansätzen. Der Optimierungsprozeß wurde in dem von der Europäischen Kommission geförderten Forschungsprojekt ESECMaSE (Enhanced safety and efficient construction of masonry structures in Europe) durchgeführt. Dabei wurden sowohl Untersuchungen zur Optimierung der Materialzusammensetzung als auch eine Optimierung des Lochbildes vorgenommen. Als Optimierungsergebnis wurden Prototypen hergestellt und in statisch zyklischen Schubversuchen untersucht. Die wichtigsten Materialeigenschaften, insbesondere die Längsdruck‐ und Längszugfestigkeit wurden erheblich verbessert. Erste Ergebnisse von Schubversuchen zeigen jedoch, daß die Bedeutung der Längsdruckfestigkeit bei anisotropen Baustoffen wie Hochlochziegeln bisher deutlich überschätzt wird.
Crystal Structures of Conformationally Locked Cyclitols: An Analysis of Hydrogen‐Bonded Architectures and their Implications in Crystal Engineering
Authors: Mehta Goverdhan , Sen Saikat , Ramesh Senaiar S.
Published: October 2006

A qualitative study has been carried out on selected polycyclitols to evaluate the potential of conformational locking of hydroxy groups in lending predictability to the O–H···O hydrogen‐bonding network observed in the crystal structures of such compounds. The polycyclitols employed in this study are conformationally locked with all the hydroxy groups destined to be axial owing to the trans ring fusion(s) in the polycyclic carbon framework. The consequent formation of intramolecular O–H···O hydrogen bonds between the 1,3‐syn diaxial hydroxy groups now permits any packing pattern in the polycyclitols to be described in terms of a small group of intramolecularly bonded molecular motifs linked to their respective neighbors by four O–H···O bonds. By using this model and the results of CSD analyses of polyols as a guide, the O–H···O hydrogen‐bonded packing motifs most likely to be observed in the crystal structure of each polycyclitol were proposed and compared with those obtained experimentally. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Collaborative care between professionals and non‐professionals in the management of eating disorders: a description of workshops focussed on interpersonal maintaining factors
Authors: Treasure J. , Sepulveda A. R. , Whitaker W. , Todd G. , Lopez C. , Whitney J.
Published: October 2006

The aim of this paper is to describe the content and processes involved in a series of workshops for carers of people with an eating disorder. These workshops were designed to equip carers with the skills and knowledge needed to be a ‘coach’ and help the person with an eating disorder break free from the traps that block recovery. The first hurdle is to overcome the unhelpful patterns of interpersonal processes between the person with an eating disorder and their carers. In both naturalistic studies and randomised controlled trials (RCT), family factors have been implicated either as moderators or mediators of outcome. High levels of expressed emotion (EE), misattributions about the illness or unhelpful methods of engaging with the eating disorder symptoms contribute to this effect. These workshops aim to reduce EE such as over protection. Carers are introduced to the transtheoretical model of change and the principles of motivational interviewing so that they can help rather than hinder change. They learn how to use reflective listening to reduce confrontation and how to sidestep resistance. Carers learn what is needed to help their daughter change by reflecting on the processes involved in changing their own behaviours in relationship with the person with eating disorders. Once they recognise that they may need to change then they can use their skills, information and insight to help change eating disorder symptoms. Copyright © 2006 John Wiley & Sons, Ltd and Eating Disorders Association.
Na+–H+ exchanger regulatory factor 1 is a PDZ scaffold for the astroglial glutamate transporter GLAST
Authors: Lee Aven , Rayfield Andrew , Hryciw Deanne H. , Ma Theingi Aung , Wang Dongsheng , Pow David , Broer Stefan , Yun Chris , Poronnik Philip
Published: October 2006

Glutamate is a key neurotransmitter and its levels in the synaptic cleft are tightly regulated by reuptake mechanisms that primarily involve transporters in astrocytes. This requires that the glutamate transporters be spatially constrained to effect maximum glutamate transport. GLAST (EAAT1) is the predominant astroglial transporter and contains a class I PDZ‐binding consensus (ETKM) in its C‐terminus. The epithelial Na+/H+ exchanger regulatory factors NHERF1 and NHERF2 are PDZ proteins that contain two tandem PDZ domains and a C‐terminal domain that binds members of the ERM (ezrin–radixin–moesin) family of membrane‐cytoskeletal adaptors. NHERF proteins have been extensively characterized in renal epithelia and their expression in brain has recently been reported; however, their function in the brain remains unknown. The aims of the current study were to (1) determine the distribution of NHERF1/2 in the rodent brain and (2) investigate whether GLAST was a physiological ligand for NHERF1/2. Immunohistochemistry revealed that NHERF1 expression was widespread in rat brain (abundant in cerebellum, cerebral cortex, hippocampus, and thalamus) and primarily restricted to astrocytes whereas NHERF2 expression was primarily restricted to endothelial cells of blood vessels and capillaries. Importantly, NHERF1 distribution closely matched that of GLAST and confocal imaging demonstrated co‐localization of the two proteins. Co‐immunoprecipitation demonstrated that GLAST, NHERF1, and ezrin associate in vivo. In vitro binding assays showed that GLAST bound directly to the PDZ1 domain of NHERF1 via the C‐terminal ETKM motif of GLAST. These findings implicate the GLAST–NHERF1 complex in the regulation of glutamate homeostasis in astrocytes. © 2006 Wiley‐Liss, Inc.
Access to diagnostic evaluation and treatment for dementia in Europe
Authors: Waldemar Gunhild , Phung Kieu T. T. , Burns Alistair , Georges Jean , Hansen Finn Ronholt , Iliffe Steven , Marking Christine , Rikkert Marcel Olde , Selmes Jacques , Stoppe Gabriela , Sartorius Norman
Published: October 2006

This paper reviews and discusses existing barriers to diagnosis and treatment for patients with dementia in Europe as well as approaches to overcome these barriers. The barriers to care are manifold, being present at all levels in each society and between countries in Europe. Multilevel and multifaceted strategies are needed to improve diagnosis and treatments for all patients with cognitive complaints. A multidisciplinary approach based on close collaboration between GPs and specialised memory clinics may be the ideal model for early accurate diagnosis and subsequently early pharmacological and psychosocial interventions. For all healthcare professionals, there should be specialised training in dementia and frequently updated practice guidelines to provide the framework for standards of care. Culture‐sensitive strategies to promote public knowledge and destigmatize dementia are essential. Policy makers and authorities should be made aware of the benefits of early access to diagnosis and treatment. Copyright © 2006 John Wiley & Sons, Ltd.
A comparison of small and large assisted living facilities for the diagnosis and care of dementia: the Maryland Assisted Living Study
Authors: Leroi Iracema , Samus Quincy M. , Rosenblatt Adam , Onyike Chiadi U. , Brandt Jason , Baker Alva S. , Rabins Peter , Lyketsos Constantine
Published: October 2006

Objectives

To compare the demographic, clinical, and psychiatric characteristics of residents living in small (≤15 beds) and large assisted living (AL) facilities in the United States.

Methods

One hundred and ninety‐eight residents in 10 large and 12 small assisted living facilities were comprehensively assessed as part of the Maryland Assisted Living Study (MD‐AL). The presence or absence of dementia and psychiatric disturbances and the facilities' recognition and management of these disorders were compared across the two types of AL. Aspects of care delivery were also compared.

Results

Small facilities had a higher prevalence of dementia (81%) compared to larger facilities (63%) and the mean Mini‐Mental State Examination (MMSE) across all residents in small facilities (mean 13.04) was than in large facilities (mean 19.93)(p = 0.000). Almost all (98%) of the residents of small homes carried a diagnosis of a dementia or other psychiatric diagnosis, compared to 74% of residents in large facilities (p < 0.001). Psychosis in particular was more prevalent in the smaller homes and the mean Neuropsychiatric Inventory score, a measure of neuropsychiatric symptoms, was higher compared to large homes. Falls were more common in larger homes despite a greater number of personal care hours per week. The use of safety devices and restraints was significantly less common in large facilities compared to smaller homes, where ‘geri‐chair’ and bedrails were more often used.

Conclusions

Rates of dementia and psychiatric disorder differ in assisted living facilities depending on size of facility. Copyright © 2006 John Wiley & Sons, Ltd.
Chemical carcinogensis in vitro: An improved method for chemical transformation in Rauscher leukemia virus‐infected rat embryo cells
Authors: Traul Karl A. , Hink Raymond J. , Wolff John S. , Wlodymr Korol
Published: October 2006

In vitro assays for careinogenesis, using mammalian cells, provide opportunity for rapid and inexpensive means, compared to in vivo assays, for studying carcinogenesis and for identifying potential carcinogens. These assays must, however, be shown to be reproducible, reliable and able to detect a variety of known carcinogens before they can be recommended for general use. We have, independently, reproduced a transformation assay which utilizes murine leukemia virus‐infected rat embryo cells as targets. In the process a new culture, designated 2FR450, was generated to replace the F1706 line, of Freeman, which is no longer available. Through careful control of the assay parameters a readily reproducible test has been developed. In 2–4 culture passages after chemical treatment, morphologically transformed foci of cells are observed while no such foci are found in noncarcinogen treated or control cultures. Over 75 compounds have been tested in this assay; 20 of these are detailed here as representative of the chemically diverse types of carcinogens detected.
The activation of mutagens in diesel particle extract with rat liver S9 enzymes
Authors: Pederson T. C. , Siak J‐S.
Published: October 2006

Reductive activation of nitroaromatic compounds by bacterial enzymes contributes to the direct‐acting mutagenicity of diesel particle extracts in the Salmonella mutation assay. In this study, the ability of mammalian enzymes to activate diesel particle extract was investigated with a rat liver S9 preparation using the nitroreductase‐deficient strain TA98NR to detect active metabolic products. The use of diesel particle extract at concentrations greater than 50 μg per plate inhibited S9 enzyme activations in the mutation assay. In addition, the S9 preparation without NADPH present decreased the residual direct‐acting mutagenicity of the particle extract. Activation by S9 enzymes of mutagens in diesel particle extract was evident as a difference in activity between assays with and without NADPH. 1‐Nitropyrene, a nitroarene identified in diesel particle extracts, was also activated by NADPH‐dependent S9 enzymes. S9 activation of both the particle extract and 1‐nitropyrene was detected only when using much lower S9 concentrations than conventionally applied in the Salmonella/S9 assay. S9 enzyme activation of 1‐nitropyrene is not merely a consequence of forming a mutagenic amine since 1‐aminopyrene was less mutagenic than 1‐nitropyrene in these assays. The NADPH‐dependent activation of 1‐nitropyrene is located in the microsomal fraction of the S9 preparation. However, activation of the diesel particle extract was more evident with the cytosol than with the microsomal fraction, demonstrating the involvement of yet other enzyme systems and extract components.
A spectrophotometric method for the quantitation of diesel exhaust particles in guinea pig lung
Authors: Rudd Colette J. , Strom Kenneth A.
Published: October 2006

Particulate material in diesel engine exhaust deposits in the lungs of exposed animals. A technique for measuring the amount of soot in the lungs would be useful for determining the rates of the deposition and clearance of the submicron particles. The paper describes the use of light extinction for quantitating diesel particles in aqueous suspension. Particles collected by electrostatic precipitation and finely suspended in 0.01 N NaOH by sonication strongly absorb visible light. The extinction of light at 750 nm is proportional to the mass concentration of particles, with an extinction coefficient of 28 ± 1 cm2 mg−1. Lungs from guinea pigs exposed to dilute diesel exhaust were dried and digested in potassium hydroxide and ethanol. The insoluble particles were centrifuged and resuspended in water by sonication. The optical density of the suspension was compared to that of suspensions made from lungs of animals not exposed to diesel exhaust, with or without known amounts of particulate added at the beginning of digestion. A concentration‐dependent increase in the total amount of particles per lung was found for guinea pigs exposed to 0, 269, 813 and 1530 μg m−3 diesel particles for 6 months.
Early pulmonary response of the rat lung to inhalation of high concentration of diesel particles
Authors: White Harold J. , Garg Bhagwan D.
Published: October 2006

Light microscopy was used to study the pathologic alterations in the rat lung after timed diesel exposures to 6000 μg m−3 of diesel particulates ranging from 6 h to 9 weeks. As a general reaction, an increase in alveolar macrophages containing diesel particles, an increase in type II pneumocytes, and an accumulation of inflammatory cells within the alveoli and septal walls was observed. Histochemical differentiation between type II cells and alveolar macrophages was clearly delineated by the use of the PAS (periodic acid Schiff) stain in which macrophages stained positive and type II cells negative for this reaction. After the 9‐week exposure, the accumulation of macrophages and accompanying type II cell reaction resulted in the formation of alveolar complexes that seemed to be preferentially localized near the terminal bronchioles. The similarity of the lesion to that of macrophage alveolitis' produced in animals repeatedly exposed to coal dust is emphasized, although the ultimate clinical significance of the complex formation cannot be assessed within the time limits of the experimental observation.
Inhibition of oxygen utilization by substances in combination
Authors: Franke John E. , Wahed Sayed A. , Hermann Edward R.
Published: October 2006

Measurement of concentrations at which substances in combination become toxic is complex, especially if quantitative definition of additive, antagonistic or synergistric toxicity is desired. Using inhibition of oxygen utilized by aerobic micro‐organisms in their metabolism of a standard substrate, seven chemicals were tested singly and in eight combinations for their graded toxic effects. In two of the experimental investigations the combined effects of three chemicals were determined. By comparing summations of the measured effects of the chemicals tested singly with similar results from testing the toxicity of actual combinations of the chemicals in solution it was found that the actual inhibitions of the oxygen utilization were essentially the same as predicted inhibitions over a range of aqueous concentrations. Statistical analysis of all combinations tested indicated the effects to be addivtive. Neither synergism nor antagonism was shown. the pure compounds tested were: mercuric chloride, potassium cyanide, nickel chloride, potassium chromate, copper sulfate, phenol and nitrobenzene. Although the toxicity of each chemical has been quite extensively studied, results regarding combined effects are relatively few. The methods presented here are applicable to many compounds in combination.
An improved method for the determination of aryl‐4‐hydroxylase activity
Authors: Lindblad William J. , Jackim Eugene
Published: October 2006

An improved method for separation of tritiated benzo[a]pyrene from tritiated water in the aryl‐4‐hydroxylase assay is presented. Quantitative retention of benzo[a]pyrene was obtained with mixed cellulose acetate and nitrate filters. Enzymatic activities obtained with this modification agreed well with those determined using the standard charcoal column extraction. This modification greatly reduces the time required to perform this assay, and allows for the determination of enzyme activity in a large number of samples.
Long‐term carcinogenicity and toxicity studies of patulin in the rat
Authors: Becci Peter J. , Hess Frederick G. , Johnson William D. , Gallo Michael A. , Babish John G. , Dailey Robert E. , Parent Richard A.
Published: October 2006

Patulin is a mycotoxin produced by a variety of Penicillium and Aspergillus species which are likely natural contaminants of various foods. The present study was conducted to determine the effects of lifetime administration of patulin in FDRL Wistar rats. Animals received patulin by gastric intubation three times per week at the level of 0.0, 0.1, 0.5 and 1.5 mg per kg body weight. The animals used in this lifetime study were derived from F0 parents exposed to equivalent levels of patulin for 4 weeks before mating, and throughout mating, gestation and lactation. Patulin treatment at 0.5 and 1.5 mg kg−1 to male rats caused a significant decrease in body weight gain in comparison to controls. Body weights of treated female rats were similar to that of control rats. No consistent significant differences among groups were noted in the hematology, clinical chemistry or urine analysis parameters measured during or at the termination of the study. Patulin administered to male and female rats at 1.5 mg kg−1 caused a significantly increased mortality rate as compared to respective control animals. The cause of death appeared to be increased pulmonary and laryngotracheal inflammation. No tumorigenic effect of patulin was observed.
Improvement in the atomic absorption determination of lead in blood
Authors: Karai Ichiro , Fukumoto Köichi , Horiguchi Shun'ichi
Published: October 2006

A simple, precise and accurate analysis for lead in blood and tissue was developed using spectrophotometry after extraction with HCl, H3PO4, KI and methyl isobutyl ketone. The results were similar to those obtained by anodic stripping voltammetry. The method is simple, requires only four reagents, does not need pH adjustment for lead extraction, saves time and is suitable for analyzing a large number of specimens.
Determination of vinyl acetate in air by gas chromatography
Authors: Sidhu Kirpal S.
Published: October 2006

A gas chromatographic analysis for vinyl acetate is presented. Vinyl acetate was sampled by adsorbing on activated carbon. It was desorbed with carbon disulfide with a mean efficiency of 83.0%. The analytical column was packed with 10% free fatty acid phase on acid‐washed Chromosorb‐P. Gas chromatographic identification was also conducted on another column packed with 0.4% Carbowax‐1500 on Carbopack A. Analysis was performed on a chromatograph equipped with a flame ionization detector. The precision (coefficient of variation) for the analytical procedure using a free fatty acid phase column was 4.0%. Based on a 10 litre air sample, the calculated limit of detection by this procedure was 0.1 parts per million.
Renal alterations in female rats following subchronic lead exposure
Authors: Vyskočil A. , Semecky V. , Fiala Z. , Čižková M. , Viau C.
Published: October 2006

Female Wistar rats were given 1% or 0.1% lead acetate in drinking water for 2 or 4 months, respectively. Urinary β2‐microglobulin, N‐acetyl‐β‐D‐glucosaminidase, lactate dehydrogenase and lysozyme were used as markers of tubular dysfunction. Excretion of albumin and glomerular filtration rate were used as indicators of glomerular impairment. Kidney and body weights and morphological changes in the kidney were also studied. Exposure to 1% lead acetate induced a mean blood lead level of 1730 μg−1 and caused only an increase of β2‐microglobulin excretion and relative kidney weight. Light microscopy of kidney revealed morphological changes mainly in the epithelial cells of the proximal tubules. The role of acetate or reduced water intake on kidney function was excluded because 1% sodium acetate or the restriction of water intake to the volume consumed by the rats of the lead‐exposed group was ineffective. Exposure to 0.1% lead acetate induced a blood lead level of 376 μg I−1, corresponding to the current level in industry workers, without any sign of nephrotoxicity. Comparison of this study with the results of a previous study on male rats indicates no sex difference in the nephrotoxicity of lead.
DNA adduct formation by mineral oils and their fractions as indicated by 32P‐postlabelling: Is adduct formation truly indicative of carcinogenic potential?
Authors: Ingram A. J. , Phillips J. C. , Lee R.
Published: October 2006

Oils of differing types, physical properties and carcinogenic activity were tested for their ability to produce epidermal DNA adducts 24 h after application to the skin of mice, using the 32P‐postlabelling method. Two studies were carried out, the first on three oils to identify the adduct‐forming components, and the second on nine oils to investigate whether the nature of the oils affected their adduct‐forming potential. In addition to the whole oils, fractions of the oils containing saturated hydrocarbons, 2–6‐ring aromatic compounds and polar compounds were tested in both studies in proportion to their concentration in the original oil. In addition, a further examination of the aromatic fractions from two carcinogenic oils was carried out in the first study by testing 2–3‐ring and 4–6‐ring subfractions (the latter containing carcinogenic polycyclic aromatic compounds (PACs)).

Results from the first study indicated that carcinogenic oils do produce adducts and that the adduct‐forming components were mainly in the aromatic fraction. When, however, subfractions of the aromatic fraction were examined, it was found that slightly higher adduct levels were produced by the 2–3‐ring aromatic fraction than with the 4–6‐ring PAC fraction. This was contrary to expectation from published work on the skin carcinogenicity of oils and suggested that some non‐carcinogenic PACs may produce adducts.

The second study indicated that although most carcinogenic oils produced adducts, some non‐carcinogenic oils can also do so. This was especially evident with a non‐carcinogenic residual oil and, as such oils have been reported to contain high levels of 2–3‐ring PACs, this was taken as further evidence that some non‐carcinogenic PACs containing three or four aromatic rings may give rise to DNA adducts.

Further studies are needed to confirm whether or not non‐carcinogenic components of oils are indeed able to produce adducts.
Toxicity evaluation of two treatment regimens for cyanide poisoning
Authors: Bhattacharya R. , Pant S. C. , Kumar Deo , Dube S. N.
Published: October 2006

Toxicological evaluation of two recently reported treatment protocols for cyanide—SN (sodium nitrite) + DMAP (4‐dimethylaminophenol) and SN + HA (hydroxylamine)—was carried out in male rats. Both treatments produced transient hyperammonaemia and decreased mean arterial pressure. Heart rate decreased and respiratory rate increased, but these changes reached the level of significance only after SN + HA. Histopathological lesions in lung, liver (SN+HA) and kidney (SN+DMAP) were predominantly in the vicinity of blood vessels.

The results indicate toxic effects in both treatment groups at a dose known to induce methaemoglobin concentration to the level of antidotal efficiency in cyanide intoxication.
Interferon‐α preserves erythrocyte and hepatocyte atpase activities from liver damage induced by prolonged bile duct ligation in the rat
Authors: Muriel Pablo
Published: October 2006

Interferons have been used to treat chronic hepatitis owing to their antiviral properties. However, now interferons are recognized to inhibit collagen production. Because fibrosis has been associated with liver damage and disfunction, the effects of interferon‐α2b on biliary obstruction‐induced cirrhosis were investigated. Obstructive jaundice was induced in male Wistar rats (ca. 200 g) by double ligation and division of the common bile duct. Control rats were sham operated. Interferon‐α2b (IFN‐α; 100 000 IU per rat) was administered subcutaneously daily after surgery. The animals were sacrificed after 4 weeks of bile duct ligation (BDL) or sham operation. Bilirubins and serum enzyme activities of alkaline phosphatase and γ‐glutamil transpeptidase (determined as markers of liver damage) increased several‐fold after BDL. Erythrocyte and hepatocyte plasma membrane Na+/K+‐ and Ca2+ ‐ATPase activities decreased significantly in the BDL group. Administration of IFN‐α to BDL rats resulted in a partial normalization of serum markers of liver damage. The normal activity of both ATPases on erythrocyte and hepatocyte plasma membranes was completely preserved by IFN‐α. It is concluded that interferons possess interesting hepatoprotective effects not related to their antiviral properties but probably associated with their antifibrogenic effect.
Subchronic toxicity of a medium‐chain chlorinated paraffin in the rat
Authors: Poon R. , Lecavalier P. , Chan P. , Viau C. , Håkansson H. , Chu I. , Valli V. E.
Published: October 2006

Groups of ten male and female weanling Sprague‐Dawley rats were fed diet containing 0, 5, 50, 500 or 5000 ppm of a medium‐chain chlorinated paraffin (C14‐17, 52% chlorination) for a period of 13 weeks. Increased relative liver weight was observed at 500 and 5000 ppm in females and at 5000 ppm in males. Relative kidney weight was increased at 5000 ppm in both sexes. Serum cholesterol was increased in the females in a dose‐related manner starting at 50 ppm. At 5000 ppm, animals of both sexes had elevated hepatic UDP‐glucuronosyltransferase activity while only females showed increased aminopyrine N‐demethylase activity. Increased urinary N‐acetylglucosaminidase activity occurred at 5000 ppm in females. Increased urinary ascorbic acid excretion monitored at week 12 and a decreased hepatic vitamin A level were detected in females receiving the 500 ppm diet and male and female rats at 5000 ppm. Mild, adaptive histopathological changes were detected in the liver of rats of both sexes at 500 and 5000 ppm, and in the thyroid of males and females starting at 500 and 50 ppm, respectively. Minimal changes were observed in the kidney proximal tubules of male rats fed the 5000 ppm diet and in the inner medulla tubules of female rats fed the 500 and 5000 ppm diets. These data indicate that the medium‐chain chlorinated paraffin produces biochemical and histological changes at dietary levels of ± 50 ppm in females and ± 500 ppm in males.
Evaluation of lymphocyte proliferation by immunohistochemistry in the local lymph node assay
Authors: Boussiquet‐Leroux C. , Durand‐Cavagna G. , Herlin K. , Holder D.
Published: October 2006

A modified version of the local lymph node assay (LLNA) is presented, using bromodeoxyuridine to label proliferating lymphocytes. Cell counting is done on mid‐sagittal sections of individual nodes under light microscopy. Two irritants (sodium lauryl sulfate and salicylic acid), four allergens of various sensitizing potential (potassium dichromate, 4‐chloroaniline, neomycin sulfate and nickel sulfate) and one chemical of unknown sensitizing potential (ethyl 3‐aminobenzoate) were tested either in the short protocol using three daily topical applications and/or in the long protocol with a pre‐exposure step under an occluded patch. A weak T cell proliferation was noted with both irritants in the short protocol, but not in the long protocol. Potassium dichromate induced a strong proliferative response in the short protocol. A lesser sensitizing potential was detected for 4‐chloroaniline, ethyl 3‐aminobenzoate and neomycin sulfate but only in the long protocol. Nickel sulfate was negative in both protocols. The long protocol was the most valuable for weak or moderate sensitizers. Histological examination of nodes ruled out intercurrent processes.

The present procedure offers several advantages. The use of a non‐isotopic marker enables this test to be run in a routine safety assessment department and allows the preparation of permanent slides. An increased specificity is obtained by restricting cell counting to the paracortex. Moreover, the collection of individual data permits statistical analysis of the results. This method is sensitive and reproducible and may be viewed as a useful adjunct to the LLNA.
Properties of an N,N‐dimethyl‐p‐aminoazobenzene Oxide Reductase Purified from Rat Liver Cytosol
Authors: Johnson Pamela R. Lashmet , Ziegler D. M.
Published: October 2006

Homogenates of all rat tissues examined, except brain, catalyze reduction of N,N‐dimethyl‐p‐aminoazobenzene N‐oxide (DMAB N‐oxide) to N,N‐dimethyl‐p‐aminoazobenzene by NADPH. Liver is the most active, and about one third of the homogenate activity of this tissue is recovered in the cytosol fraction. The purified cytosol enzyme has the properties of a tetrameric protein (Mr 370,000) consisting of identical subunits free from chromophores that absorb in the visible spectrum and from metals or other detectable prosthetic groups. The purified reductase is also free from NADPH oxidase and from cytochrome c or azo reductase activities. The enzyme is quite specific for NADPH as reductant and DMAB N‐oxide as the electron acceptor. Reduction of other N,N‐dimethyl‐arylamine or alkylamine oxides as well as N‐methylheterocyclicamine oxides could not be detected. Analysis of kinetic data indicate that, at saturating concentrations of the other substrate, 21 μM NADPH and 700 μM DMAB N‐oxide are required for half maximal velocity. At infinite concentrations of both substrates the turnover is 150 min−1 at 37 °C.
Oxidative metabolism of some hydrazine derivatives by rat liver and lung tissue fractions
Authors: Erikson John M. , Prough Russell A.
Published: October 2006

The enzyme systems in rat liver and lung responsible for the oxidative metabolism of hydrazine derivatives were studied to determine whether these enzymes, cytochrome P‐450 and monoamine oxidase, were responsible for metabolically activating hydrazines to carcinogenic/toxic metabolites. Cytochrome P‐450 preferentially oxidized the nitrogen to nitrogen bond of 1,2‐disubstituted hydrazines and hydrazides, while monoamine oxidase oxidized the nitrogen to nitrogen bond of all the classes of hydrazine derivatives that were tested. Oxidation of the nitrogen to nitrogen bond led to the formation of stable azo intermediates in the case of 1,2‐disubstituted hydrazines and to unstable monoazo (diazene) metabolites in the case of monosubstituted hydrazines and hydrazides. In addition, cytochrome P‐450 preferentially oxidized the carbon to nitrogen bond of monoalkylhydrazines; this reaction resulted in the formation of aldehyde metabolites (via hydrazone intermediates).

Monosubstituted hydrazines were shown to be potent, irreversible inhibitors of mitochondrial monoamine oxidase. In contrast, the 1,2‐disubstituted hydrazines appeared to be good substrates for the monoamine oxidase and served as competitive inhibitors at high concentrations. There did not appear to be any monoamine oxidase isozyme (form A or B) specificity in the metabolism of either the 1,2‐disubstituted hydrazines or the monoalkylhydrazines, ethyl‐ and n‐propylhydrazine.
Biochemical interactions of carbamates and ecothiophate with the activated conformation of nicotinic acetylcholine receptor
Authors: Mansour Nabil A. , Valdes James J. , Shamoo Adil E. , Annau Zoltan
Published: October 2006

Purified Torpedo nobiliana electric organ acetylcholine receptor (AChR) was reconstituted into membranes containing natural phospholipids supplemented with cholesterol (25% w/w). The reconstituted system facilitates the study of the effects of drugs on the regulation of the AChR channel complex under both resting and carbachol (carb)‐stimulated conditions. Neostigmine (Neo) was the only carbamate to induce activation of [3‐H]‐phencyclidine ([3‐H]‐PCP) binding to the channel sites, acting as a weak agonist. The activation of [3‐H]‐PCP binding is dependent upon the nature of the reconstituted systems, with carb/Neo activation ratios of 8, 3, and 1 for the intact purified AChR vesicles fraction (PVF), the PVF reconstituted in phospholipid/cholesterol (CRPVF), and the PVF reconstituted in phospholipid (RPVF), respectively. The carbamates Neo, physostigmine (Physo), and pyridostigmine (Pyrido) inhibited carb‐activated [3‐H]‐PCP binding with Ki values of 10, 20, and 1,600 μM, respectively. The inhibition was mixed competitivenoncompetitive in nature. The characteristic response of CRPVF to carb‐stimulated [22‐Na] influx was inhibited by the three carbamates, with IC‐50 values of 6,50, and 1,000 μM for Neo, Physo, and Pyrido, respectively. The quaternary ammonium organophosphate ecothiophate (Eco) inhibited carb‐stimulated [22‐Na] influx with potency similar to that of Neo. Preincubation of AChR preparation with the carbamates and ecothiophate caused a reduction in the binding of [125‐I]‐α‐ bungarotoxin ([125‐I]‐α‐BGT) with the following decreasing order of potency: Neo < Physo < Eco < Pyrido. Calcium has a direct modulatory role on the time‐course inhibition of [125‐I]‐α‐BGT binding by these drugs. While we observed a high potency of Neo and Physo in inhibiting [125‐I]‐α‐BGT binding, it was undetectable for the carbamate insecticide 2‐methyl‐2‐(methylthio)propionaldehyde‐O‐(methylcarbamoyl)oxime (aldicarb). These data suggest that the potent anticholinesterase carbamate agents interact differently with the AChR and its ionic channel. Their interactions with the nicotinic AChR channel system can be described as (a) weakly agonist, (b) directly acting on the open conformation of the channel, and (c) blocking the AChR‐binding sites.