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  • 1
    Electronic Resource
    Electronic Resource
    Characterization of the effects of an airborne mixture of chemicals on the respiratory tract and smoothing polynomial spline analysis of the data (1995)
    Springer
    Archives of toxicology 69 (1995), S. 579-589 
    Details
    ISSN: 1432-0738
    Keywords: Key words Sensory irritation ; Pulmonary irritation ; Airflow limitation ; Machining fluids ; Toxicity of mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We expanded a previously published (Vijayaraghavan et al. 1994) computerized system to analyze the breathing pattern of unanesthetized mice in order better to recognize and quantify the effects of an airborne mixture of chemicals at three different levels of the respiratory tract. The airborne chemical mixture used was a machining fluid. Such fluids are widely used in industry and a large number of workers are exposed to these airborne mixtures. We found this mixture to be capable of inducing three types of effects on the respiratory tract: sensory irritation of the upper respiratory tract (S), airflow limitation along the conducting airways (A) and pulmonary irritation (P). Depending upon the exposure concentration, mainly S or P effects were obtained but an A effect was also identified. The three types of effects occurred at various times during the exposures and, furthermore, within a group of exposed animals some exhibited one type of effect while others exhibited another type. In order to analyze such complex data sets, two statistical methods for smoothing polynomial splines were utilized: the maximum likelihood (ML) method and generalized cross validation (GCV) method. The results indicated that previous methods used to characterize a single effect of airborne chemicals can now be extended to evaluate mixtures likely to induce multiple types of effects. However, statistical analysis methods, either the ML or GCV methods, or other appropriate methods are needed to evaluate the responses obtained due to the complex effects that a mixture can induce in comparison to single chemicals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002040050217
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  • 2
    Electronic Resource
    Electronic Resource
    Characteristic modifications of the breathing pattern of mice to evaluate the effects of airborne chemicals on the respiratory tract (1993)
    Springer
    Archives of toxicology 67 (1993), S. 478-490 
    Details
    ISSN: 1432-0738
    Keywords: Breathing pattern ; Mice ; Airborne chemicals ; Respiratory tract
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A system was developed for exposure of unanesthetized mice to airborne chemicals and for continuous measurement of their breathing pattern prior to, during and following exposure. By measuring inspiratory and expiratory airflows (VI and VE), and integration with time to yield tidal volume (VT), we obtained characteristic modifications to the normal breathing pattern. These permitted recognition that a specific portion of the respiratory tract was affected by the selected airborne chemicals. Following recognition, we also quantitated the degree of effect using one specific measurement in each case. An effect on the upper respiratory tract, induced by the sensory irritant, 2-chlorobenzylchloride, was quantitated by measuring a decrease in respiratory frequency. An effect on the conducting airways, induced by the airway constrictor, carbamylcholine, was quantitated by a decrease in VE at the mid-point of VT. An effect at the alveolar level, induced either by the vagal nerve ending stimulant, propranolol, or by the pulmonary irritant, machining fluid G, was quantitated by an increase in the length of a pause induced at the end of expiration. The system is easy to construct and operate and can be used to rapidly evaluate the effects of airborne chemicals on the respiratory tract.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01969919
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  • 3
    Electronic Resource
    Electronic Resource
    An attempt to define a just detectable effect for airborne chemicals on the respiratory tract in mice (1996)
    Springer
    Archives of toxicology 70 (1996), S. 567-578 
    Details
    ISSN: 1432-0738
    Keywords: Key words Sensory irritation ; Pulmonary irritation ; Airflow limitation ; Machining fluids ; Metal working fluids ; Toxicity of mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We have attempted to define a just detectable effect (JDE) for three different types of reactions along the respiratory tract: (a) sensory irritation of the upper airways (S), (b) airflow limitation along the conducting airways (A), and (c) pulmonary irritation at the alveolar level (P1 or P). Each type of reaction, S, A, P1 or P, was recognized by analyzing the breathing pattern of unanesthetized mice held in body plethysmographs. A rule-based computer program analyzed each breath during a period of 3.75 h and classified each breath as normal (N) or falling in any of the above categories (i.e., S, A, P1 or P). Eight groups of four mice were used for sham exposures: exposed to water vapor. These data sets were used, as sham exposure data, to define the variation which can occur with time in order to define an expected range of normal variation. Once this range was established, we defined JDE values for each type of effect and used such values to evaluate the results obtained in exposed animals. Eight groups of four mice were exposed to a mixture of airborne chemicals, machining fluid G (MFG), at concentrations from 0.17 to 55 mg/m3. Data sets for individual animals and for each group of animals exposed to MFG were analyzed to determine if and when a particular effect occurred. It was possible to recognize the effects of low exposure concentrations on groups of exposed animals or individual animals within each group. This procedure will be valuable when investigating the effect of airborne chemicals and when it is impossible to generate high exposure concentrations to define concentration-response relationships.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002040050314
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  • 4
    Electronic Resource
    Electronic Resource
    Structure-activity relationships of volatile organic chemicals as sensory irritants (1998)
    Springer
    Archives of toxicology 72 (1998), S. 125-140 
    Details
    ISSN: 1432-0738
    Keywords: Key words Sensory irritation ; Structure activity relationship ; Quantitative structure-activity relationships ; QSAR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We used a database of 145 volatile organic chemicals for which the sensory irritation potency (RD50) has been reported in mice. Chemicals were first separated into two groups: nonreactive and reactive, using Ferguson's rule. This rule suggests that nonreactive chemicals induce their effect via a physical ( p) mechanism (i.e., weak forces or interactions between a chemical and a biological receptor). Therefore, appropriate physicochemical descriptors can be used to estimate their potency. For reactives, a chemical (c) mechanism (i.e., covalent bonding with the receptor) would explain their potency. All chemicals were also separated on the basis of functional groups and subgroups into 24 classifications. Our results indicated that the potency of nonreactive chemicals, regardless of their chemical structure, can be estimated using a variety of physicochemical descriptors. For reactive chemicals, we identified five basic reactivity mechanisms which explained why their potency was higher than that estimated from physicochemical descriptors. We concluded that Ferguson's proposed rule is adequate initially to classify two separate mechanisms of receptor interactions, p vs c. Several physicochemical descriptors can be used to estimate the potency of p chemicals, but chemical reactivity descriptors are needed to estimate the potency for c chemicals. At present, this is the largest database for nonreactive-reactive chemicals in toxicology. Because of the wide variety of c chemicals presented, a semi-quantitative estimate of the potency of new, or not previously evaluated, c chemicals can be arrived at via comparison with those presented and the basic chemical reactivity mechanisms presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002040050479
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    The Toxicity of Smoke From Polymeric Materials During Thermal Decomposition (1985)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Pharmacology 25 (1985), S. 325-347 
    Details
    ISSN: 0362-1642
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Medicine , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.pa.25.040185.001545
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  • 6
    Electronic Resource
    Electronic Resource
    Preferences and normal goods: A necessary and sufficient condition
    Amsterdam : Elsevier
    Journal of Economic Theory 51 (1990), S. 423-430 
    Details
    ISSN: 0022-0531
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Economics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0022-0531(90)90026-G
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  • 7
    Electronic Resource
    Electronic Resource
    Computer assisted recognition and quantitation of the effects of airborne chemicals acting at different areas of the respiratory tract in mice (1994)
    Springer
    Archives of toxicology 68 (1994), S. 490-499 
    Details
    ISSN: 1432-0738
    Keywords: Key words: Sensory irritation – Pulmonary irritation – Airflow limitation – Mice – Airborne chemicals – Propranolol – Carbamylcholine – 2-Chlorobenzylchloride – Trigeminal nerve endings – Vagal nerve endings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The pattern and timing of a normal breath in unanesthetized mice was analyzed from measurement of inspiratory and expiratory airflows (V.I and V.E). Airflow was measured via a differential pressure transducer, attached to a pneumotachograph, which itself was attached to a body plethysmograph into which a mouse was placed. The analog voltage from the differential pressure transducer was digitized and stored for analysis on a microcomputer. Criteria were developed to classify each breath as normal (N) or belonging into one of seven abnormal categories. The abnormal categories were arrived at by computer analysis, recognizing specific modifications of the normal pattern into patterns of: sensory irritation of the upper respiratory tract (S), airflow limitation within the conducting airways of the lungs (A) or pulmonary irritation at the alveolar level (P). Combinations of these effects, i.e., S+A, P+A, P+S and P+S+A were also recognized. Computer analysis of each breath also permitted quantitative evaluation of the degree of S, A or P abnormalities. To induce each type of effect we used inhalation exposures to 2-chlorobenzylchloride, carbamylcholine or propranolol. We propose that this approach will permit rapid evaluation of the possible effects of airborne chemicals at three levels of the respiratory tract, with the classification of the type of effect easily obtained in an objective way using well defined criteria, followed by quantitation of the degree of each effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002040050101
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    Paper (German National Licenses)
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  • 8
    Electronic Resource
    Electronic Resource
    Use of experimental materials to assess toxicological tests for rating polymeric materials under thermal stress (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 2 (1978), S. 136-140 
    Details
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: In order to evaluate the performance of the indices of toxicity which have been developed, thermal decomposition products of three polymers, polyvinylchloride, polychloroprene, and polycarbonate were tested for sensory irritation, physiological stress induction, and acute lethality. Each polymer has been contrasted with the same polymer containing 5% zinc ferrocyanide. The most irritating and the most stressful pyrolysis products were those from polyvinylchloride. The least irritation and stress were associated with polycarbonate decomposition products. The acute lethality for polychloroprene was higher than that of the other two polymers by a factor of 4. The addition of zinc ferrocyanide had a variable effect, depending on the polymer and the index of toxicity being evaluated. Sensory irritation was lessened by the presence of zinc ferrocyanide in polycarbonate. The sample weight required to cause death of 50% of the animals was reduced for the two hydrogen chloride-generating polymers, polyvinylchloride and polychloroprene. However, the acute lethality of polycarbonate did not change with addition of zinc ferrocyanide. By itself, zinc ferrocyanide decomposed very slowly during heating, caused almost no irritation or stress, and no deaths.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fam.810020308
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    Paper (German National Licenses)
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  • 9
    Electronic Resource
    Electronic Resource
    Toxicity of Teflon®, similar results obtained with radiant-convective heat sources or in the hot fire gases (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 8 (1984), S. 54-55 
    Details
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fam.810080110
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    Paper (German National Licenses)
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  • 10
    Electronic Resource
    Electronic Resource
    Role of small scale toxicity testing in hazard control (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Fire and Materials 13 (1988), S. 122-129 
    Details
    ISSN: 0308-0501
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Architecture, Civil Engineering, Surveying , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fam.810130117
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    Paper (German National Licenses)
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