bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trophic structure of a boreal forest arthropod community revealed by stable isotope (δ13C, δ15N) analyses
Authors: BENNETT Pamela M. , HOBSON Keith A. 
Published: March 2009

AbstractTerrestrial arthropods are important components of boreal ecosystems but relatively little is known about their trophic structure within communities. We measured δ13C and δ15N values in a broad range of arthropod taxa (Coleoptera, Diptera, Ephemeroptera, Homoptera, Hymenoptera, Lepidoptera, Odonata, Orthoptera, Araneae) from boreal forest in Prince Albert National Park, Saskatchewan, Canada. Isotopic measurements supported previous conventional investigations on foraging niches based on stomach content analysis and direct feeding observations but additional, new information was also obtained using the stable isotope approach. Significant differences were observed in both δ15N and δ13C values between various orders and families or superfamilies within orders. Higher variance in stable isotope values for scavengers (e.g. carrion beetles; Coleoptera, Silphidae) and generalists (e.g. ground beetles; Coleoptera, Carabidae) was found compared to specialists (e.g. grasshoppers; Orthoptera). Consistent isotopic differences between terrestrial and aquatic species were not found. However, aquatic insect δ13C values tended to be lower than those of their terrestrial counterparts. We discuss the potential for using stable isotope methods to reconstruct trophic linkages and interaction involving arthropods.
Atypical neurofibroma of the skin and subcutaneous tissue: clinicopathologic analysis of 11 cases
Authors: Jokinen Chris H. , Argenyi Zsolt B. 
Published: March 2009

Background: Neurofibroma (NF) is a relatively common cutaneous tumor, which typically presents little diagnostic difficulty. Occasionally, however, pleomorphic cells may be present in NF raising consideration of other neoplasms like malignant peripheral nerve sheath tumor (MPNST).Methods: This study examines the clinicopathologic and immunohistochemical features of 11 dermal and subcutaneous ‘atypical’ NF.Results: 9/11 (82%) atypical NF were from females, aged 8–70 years. One patient had neurofibromatosis‐1. Most presented on the extremities or trunk. The atypical cells had large hyperchromatic, irregular nuclei, and were arranged in a distinct lamellar or fibrillar pattern. Some tumors were hypercellular, but marked density characteristic of MPNST was not observed. All were nonplexiform. Mitoses were mostly absent. The pleomorphic cells expressed S‐100 protein. All were negative for p53. MIB‐1 was negative in 7/10 (70%) and stained only rare cells in 3 (30%). Epithelial membrane antigen (EMA) and p16 expression were variable. Of six patients with available follow‐up, no tumor recurred and none developed malignancy (range 6–63, mean 33 months).Conclusions: Superficial atypical NF, while morphologically unusual, has no apparent association with neurofibromatosis‐1 or short‐term risk of recurrence or malignant transformation. Awareness of this variant is important in order to avoid misdiagnosis of a more aggressive neoplasm.
Receptor binding properties of amperozide
Authors: Svartengren J. , Simonsson P. 
Published: March 2009

AbstractThe receptor pharmacology of amperozide was investigated with in vitro radioligand binding technique. Amperozide possessed a high affinity to the 5‐HT2receptors (Ki= 16.5±2.1 nM) and a moderate affinity to α1‐adrenergic receptors of rat cerebral cortical membranes (Ki=172±14 nM). The affinity of amperozide for striatal and limbic dopamine D2receptors was low and not significantly different (Ki±S.E.M. = 540 ± 59 nM vs 403±42 nM; p<0.11, n = 4). The affinity for striatal and limbic 5‐HT2receptors was measured as well and found to be very close to the affinity to the cerebral cortical 5‐HT2receptor. The drug affinity for D2and 5‐HT2receptors seems thus not to be influenced by the location of the receptor moiety. The affinity for several other rat brain receptors such as 5‐HT1A, α2‐adrenergic, dopamine D1muscarinic M1 and M2, opiate sigma and β2‐adrenergic was low.The pseudo‐Hill coefficient of the amperozide competition binding curve was consistently higher than one indicating antagonistic and complex interactions with the 5‐HT2receptor or with α1‐adrenergic and dopamine D2receptors.The antagonistic properties of amperozide were investigated by its ability to antagonize the serotonin‐induced formation of inositol‐1‐phosphate in human blood platelets. Amperozide inhibited this 5‐HT2receptor‐mediated intracellular response with similar potency as ketanserin.These results suggest that amperozide is a selective 5‐HT2receptor antagonist.
Amperozide and conditioned behaviour in rats: potentiation by classical neuroleptics and α‐methylparatyrosine
Authors: Egbe Patrik , Engel Jörgen , Gustafsson Bo , Christensson Erik 
Published: March 2009

AbstractAmperozide, a new putatively antipsychotic compound, has been evaluated for its effect on conditioned avoidance response and food‐reinforced lever‐pressing. Given alone, amperozide was almost equipotent to clozapine, but less potent than haloperidol in both test models. It was found that there was a statistically significant synergism, in these two models, between amperozide and classical neuroleptics. Since amperozide is inactive in behavioural tests reflecting striatal dopaminergic mechanisms, the synergistic effect could be of great therapeutic value in the treatment of psychotic disorders.
Effects of amperozide on induced turning behaviour in 6‐OHDA lesioned rats
Authors: Christensson Erik G. 
Published: March 2009

AbstractThe effect of amperozide on DA synapses was studied in 6‐OHDA lesioned rats exhibiting a specific turning behaviour in response to the DA agonists apomorphine and pergolide or indirectly acting stimulating agents like amphetamine. Amperozide, unlike classical neuroleptics, failed to antagonize apomorphine induced turning behaviour in a regular fashion, but showed pergolide antagonism within the D2 receptor selective dose range, suggesting a type of selective interference with dopaminergic nerve transmission which differs from that caused by classical neuroleptics. Furthermore, amperozide antagonized the turning behaviour induced by amphetamine, presumably by interfering with the availability of newly synthesized DA and NA suggesting a similar influence also on other DA releasing agents. Although amperozide potentiated the effects of α‐MPT, the drug seemed not to influence the reserpine sensitive pool of DA.
The effect of amperozide on uptake and release of [3H]‐dopamine in vitro from perfused rat striatal and limbic brain areas
Authors: Eriksson Eva , Christensson Erik 
Published: March 2009

AbstractAmperozide, a putatively antipsychotic drug, was studied for its effects on uptake and release of [3H]‐dopamine in rat brainin vitro.Amperozide inhibited uptake of [3H]‐dopamine in striatal chopped tissuein vitrowith an IC50of 18 μM. It also increased basal release of [3H]‐dopamine from perfused rat striatal and limbic tissuein vitroat concentrations above 5 μM. Release of [3H]‐dopamine from perfused rat striatal and limbic tissue stimulated with 5 μM amphetamine, was inhibited by 1 μM amperozide to 46%. No significant difference was found for the effect of amperozide onin vitrorelease of [3H]‐dopamine from corpus striatum compared to tissue from limbic brain regions; neither on basal release nor on amphetamine‐stimulated release of dopamine.
LIGHT THERAPY OF DEPRESSION; BASAL AND CLINICAL ASPECTS
Authors: Wetterberg Lennart 
Published: March 2009

SUMMARYThe effects of treatment with bright light in different forms of depressive conditions are described. The therapeutic mode rests on the hypothesis that they will normalize disturbed diurnal rhythms. The results have been more favourable when light has been given in the morning compared with in the evening, and in patients with seasonal depression rather than in those with non‐seasonal illness.
Human Biological Monitoring of Occupational Genotoxic Exposures
Authors: Knudsen Lisbeth E. , Sorsa Marja 
Published: March 2009

AbstractHuman biological monitoring is a valuable tool for exposure assessment in groups of persons occupationally exposed to genotoxic agents. If the monitoring activity covers genetic material the term genetic monitoring is used. The methods used for genetic monitoring are either substance specific, e.g. the quantitation of identified DNA‐adducts or substance unspecific as is the measurement of DNA‐repair. The sample material used for analysis must be well characterized and subject to uniform processing for comparison of the results. Confounding factors of smoking, age and sex must be well controlled for and the biomonitoring results should preferentially be linked with accurate ambient air monitoring. In persons occupationally exposed to styrene the endpoints of DNA‐damage and DNA‐repair in genetic monitoring are methods of choice in exposure situations above the current Danish (25 ppm) or Finnish (20 ppm) occupational exposure limit value of styrene in ambient air.The consideration of ethical issues in human genetic monitoring is an important but often overlooked aspect. This includes the scientific and preventional relevance of performing a test on individuals, pre‐ and post study information of donors and confidentiality as well as ownership of the results.
Cancer Risk Related to Genetic Polymorphisms in Carcinogen Metabolism and DNA Repair
Authors: Poulsen Henrik E. , Loft Steffen , Wassermann Karsten 
Published: March 2009

Abstract:Chemical carcinogenesis involves metabolism in the body of the carcinogen to the ultimate carcinogen and its interaction with DNA. There is considerable interindividual variation in the metabolic ability to activate as well as detoxify the carcinogens and in the ability to repair the carcinogen‐DNA adducts. In many cases such differences occur as genetic polymorphisms and form the basis for variation in susceptibility to carcinogens and thereby to cancer risk.The activation mechanism is particularly related to the cytochromes P‐450 (CYPs), and four of these are known to activate carcinogens: CYP1A1, CYP1A2, CYP2E1, and CYP3A4. Increased cancer risk has been related to polymorphisms in the CYPs and other activating enzymes.The DNA repair mechanisms show considerable complexity, and deficient repair mechanisms in certain human disorders are clearly related to increased cancer risk. Yet, there is no unambiguous epidemiological evidence available for cancer risk among individuals in general. In vivo methods have to be refined and developed for use in epidemiological studies.
The Relative Importance of Mutagens and Carcinogens in the Diet
Authors: Lutz Werner K. , Schlatter Josef 
Published: March 2009

AbstractKnown mutagens and carcinogens in the diet were compiled and the risk of cancer was estimated on the basis of average exposure levels in Switzerland and carcinogenic potencies from rodent bioassays. The analysis showed that, except for alcohol, the sum of all known dietary carcinogens could only explain a few percent of the cancer deaths attributed by epidemiologists to dietary factors. The discrepancy was explained by a “carcinogenicity” of excess macronutrients. This hypothesis was based on an evaluation of dietary restriction experiments in rats and mice, where a dramatic reducing effect on spontaneous tumour formation was seen. From these experiments, a "carcinogenic potency" was deduced for food in excess (TD50 approximately 16 g/kg per day). Overnutrition in Switzerland was converted into excess food intake and the cancer risk estimated on the basis of the TD50 value. The resulting risk of 60,000 cases per one million lives would allow to explain by overnutrition almost all "diet‐related" cancer deaths in humans.
Carcinogenicity and Drinking Water
Authors: Dayan Anthony D. 
Published: March 2009

Abstract: Water is a powerful solvent that readily dissolves many natural and synthetic substances from the enviroment (e.g. inorganic salts, humic acids and pesticide residues). The processes of purification, disinfection and preparation and storage necessary to provide and distribute drinking water may introduce further chemicals, including some used for these purposes and others derived by interaction between them and the compounds of natural origin. The composition of drinking water, therefore, is complex and varies between sites and with the seasons. Modern technology is employed to minimise the amounts of many of these substances, but some may persist, including derivatives generated by halogenation and ozonation for disinfection.Some of the substances are genotoxic in the laboratory and a few are proven experimental carcinogens ‐ all at much higher concentrations than those normally found in a drinking water supply.Many ecological and epidemiological surveys have been done to compare the occurrence of various types of tumour in man with exposure to different types of drinking, but no consistent or reliable association has been found. There are serious and probably irremediable methodological weaknesses in these attempts, because of the difficulty of defining the nature of the waters consumed over a major part of life, and the variable composition of waters. The surveys do not permit even a realistic assessment of the upper confidence limit of the exclusion of the risk.Thus, although there is some experimental indication of the possible presence of carcinogenic substances in most or all drinking waters, and of how they are formed, the concentrations are very low and there is no realistic evidence that they have caused harm to man. The problem is one of importance to all of us, but its very generality makes it almost impossible to explore. It is very important that the proven, vital benefits of water treatment far outweigh concern about this notional chemical risk.‘… for blessed be water that giveth life…’from an ancient Jewish prayer
On the Substitution for Carcinogens in the Working Environment
Authors: Goldschmidt Gitte , Olsen Erik , Svane Ole 
Published: March 2009

AbstractThe ultimate solution in prevention of occupational cancer risks would be to remove carcinogens from the working environment. Elimination of carcinogenic substances can be achieved by replacement of the carcinogen with non‐carcinogen(s) having the same functionality, or by using a different process that produces adequate results without the use of carcinogenic agents.This paper presents selected methods and tools, which have been used for substitution purposes in practice. These are: 1. a strategy for substitution, 2. a tool for creating ideas on how to substitute, 3. a software package, SUBTEC, for solving some technical and industrial hygiene problems, and 4. a proposal for a strategy to deal with organizational and psychological barriers encountered when changes are to be introduced.
Some Ethical Considerations and the Status of Dietary Advice
Authors: Hill Michael 
Published: March 2009

AbstractDietary guide‐lines are currently given to whole populations whether the recipients have asked for it or not, and this raises ethical and practical problems. If we have not been asked for advice, what right do we have to tell people what they “ought” to eat? Are we sufficiently sure of the benefits of following our advice? Could we, in fact, be wrong about it? Are we sure of the absence of "side effects" of our advice? If not, are we sure that the balance between risk and benefit is favourable? Might our advice, in fact, do more harm than good? Would it not be better to restrict our advice to those at high risk of diet‐ related cancer? These issues are all discussed. Furthermore, the conclusions from the European Cancer Prevention (ECP) symposium and workshop on public education on diet and cancer are presented.The major conclusion is that the concept of general guide‐lines should be abandoned in favour of guide‐lines targeted to specific groups. In addition, it is concluded that the recent evidence had led to considerable confusion regarding dietary fibre and cancer, and also regarding dietary fat and cancer. The recent evidence strengthens the association between high intake of fresh fruit and vegetables and low risk of cancers at a number of sites.
Metabolism and Elimination of Inhaled Drugs and Airborne Chemicals from the Lungs
Authors: Bond James A. 
Published: March 2009

Abstract:Inhalation is a common route by which people are exposed to many toxic chemicals. Inhaled chemicals can deposit in various regions of the respiratory tract. The factors that determine deposition site include chemical reactivity and water solubility for gases and vapors, and shape, physical size, and density for particles. Metabolic activation of chemicals by respiratory tract tissues may play an important role in both the pathogenesis of diseases in these tissues or in modifying the effective dose to tissues distal to the respiratory tract. This paper is a review of the state‐of‐the‐knowledge regarding the regional distribution of xenobiotic metabolizing enzymes in the conducting airways and pulmonary tissue of several animal species, including humans. All segments of the respiratory tract, including the periphery of the pulmonary compartment, contain enzymes (Phase I and II) that metabolize xenobiotic compounds. In general, the data indicate that the pulmonary tissue has a higher metabolic activity toward inhaled chemicals than other regions of the respiratory tract, such as the trachea and bronchi. However, even within an anatomical region of the respiratory tract, there is a non‐uniform distribution of enzymes within the individual cell types. Significant species differences exist in metabolic activity toward a number of substrates. However, some generalities can be made. Firstly, the ratio of activating/inactivating enzyme activities in all species is, in general, less than 1. A second point is that this ratio is considerably higher in rodent animal species than humans. This indicates that caution needs to be exercised when extrapolating metabolic data derived from rodents to human metabolic capability.
Venous Catheter Implantation in the Minipig Surgical Approaches and Refinements
Authors: Webb Anthony J. 
Published: March 2009

Abstract: In spite of requiring invasive implantation procedures, chronic venous catheters offer a number of benefits in biomedical research involving pig:

– avoidance of long term or repeated stress due to restraint for venepuncture

– assured delivery of compounds into venous blood

– sampling is always from the same site

– use of large central veins ensures representative samples, in large quantities

– central venous sites allow rapid dilution or bufferng of compounds whcich may potentially irritant

– facilitate long term and infusion studies

Common sites of access to the venous system are jugular vein or its tributaries and the femoral vein. Experience has shown the jugular approach to the cranial vena cava to give superior performance. The presentation will focus on this approach by surgical exposure of the vessel with reference to the potential use of percutaneous introducer sheaths and Seldinger technique which offer reduced invasiveness of catheter insertion.Catheters may be either exteriorised through the skin or attached to a totally implanted vascular access port (VAP). The management of the skin‐implant interface with materials such a Dacron velour which favour adherence to the animal's own tissue, obliterating space in which infection may arise and providing anchorage is advocated. Fully implantable pumps for infusion studies may also be used.Catheter related sepsis (CRS) is the chief and most significant complication of chronic vascular access in any species, in the pig, CRS is particularly resistant to therapy in comparison with other species. Methods for prevention of catheter related will be outlined.
The Inhibitory Effect of Ambroxol on Respiratory Burst, Degranulation and Cytosolic Ca2+ Change in Degraded Immunoglobulin G‐Activated Neutrophils
Authors: Park No Hyuk , Han Eun Sook , Lee Chung Soo 
Published: March 2009

Abstract: Superoxide and H2O2 production by neutrophils stimulated by 0.5 mg/ml degraded immunoglobulin G (IgG) and 1 μM N‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP) was inhibited by ambroxol in a dose‐dependent fashion, and at the concentration of 100 μM, 43.3% to 64.3% of inhibitions were detected. The inhibitory effect of ambroxol on H2O2 production by neutrophils was greater than that on superoxide production. The production of nitrite by lipopolysaccharide‐activated murine peritoneal macrophages was significantly attenuated by ambroxol in a dose‐dependent fashion and NG‐monomethyl‐L‐arginine (NMMA). Ambroxol decreased the release of myeloperoxidase and lysozyme evoked by 0.5 mg/ml degraded immunoglobulin G and 1 μM fMLP in a dose‐dependent fashion, and at the concentration of 100 μM, 37.1% to 64.2% of inhibitions were observed. The stimulatory effect of phorbol 12‐myristate 13‐acetate (PMA) (0.1 μg/ml) on superoxide production and myeloperoxidase, which is inhibited by 100 nM staurosporine, was not affected by 100 μM ambroxol. Degraded immunoglobulin G (0.5 mg/ml) caused an immediate elevation of [Ca2+]i, in fura‐2 load neutrophils in 1.23 mM Ca2+‐containing medium. Preincubation of neutrophils with 10 μM to 100 μM ambroxol, 5 mM EGTA and 100 μM verapamil depressed the elevation of [Ca2+]i elicited by 0.5 mg/ml degraded immunoglobulin G.In conclusion, the inhibitory action of ambroxol on stimulated neutrophil responses, including respiratory burst and lysosomal enzyme release, appears to be attributed to its depressant action on the activation process, including the change in intracellular Ca2+ level, in which the role of protein kinase C is uncertain.
Understorey plant and soil responses to disturbance and increased nitrogen in boreal forests
Authors: Manninen O.H. , Stark S. , Kytöviita M.‐M. , Lampinen L. , Tolvanen A. 
Published: March 2009

AbstractQuestion: How do N fertilization and disturbance affect the understorey vegetation, microbial properties and soil nutrient concentration in boreal forests?Location: Kuusamo (66°22′N; 29°18′E) and Oulu (65°02′N; 25°47′E) in northern Finland.Methods: We conducted a fully factorial experiment with three factors: site (two levels), N fertilization (four levels) and disturbance (two levels). We measured treatment effects on understorey biomass, vegetation structure, and plant, soil and microbial N and C concentrations.Results: The understorey biomass was not affected by fertilization either in the control or in the disturbance treatment. Fertilization reduced the biomass of deciduous Vaccinium myrtillus. Disturbance had a negative effect on the biomass of V. myrtillus and evergreen Vaccinium vitis‐idaea and decreased the relative proportion of evergreen species. Fertilization and disturbance increased the biomass of grass Deschampsia flexuosa and the relative proportion of graminoids. The amount of NH4+ increased in soil after fertilization, and microbial C decreased after disturbance.Conclusions: Our results suggest that the growth of slow‐growing Vaccinium species and soil microbes in boreal forests are not limited by N availability. However, significant changes in the proportion of dwarf shrubs to graminoids and a decrease in the biomass of V. myrtillus demonstrate the susceptibility of understorey vegetation to N enrichment. N enrichment and disturbance seem to have similar effects on understorey vegetation. Consequently, increasing N does not affect the rate or the direction of recovery after disturbance. Moreover, our study demonstrates the importance of understorey vegetation as a C source for soil microbes in boreal forests.