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At least 19 recordsLinked to original sources

PubMed2000

Reproducibility of the University of Toronto self-administered questionnaire used to assess environmental sensitivity.

Environmental sensitivity patients report symptoms provoked by low-level exposure to a wide range of substances. Features of published case definitions include nature of onset, chronicity, symptom provocation by multiple substances, symptom provocation by an escalating number of exposures, involvement of multiple body systems including the nervous system, provocation by unrelated substances, and addictive behaviors. This study assessed the reproducibility of a Canadian self-administered questionnaire, the University of Toronto Health Survey, designed to determine the prevalence of the features described in these case definitions. A total of 191 eligible respondents aged 16-70 years who attended several types of medical practices in 1994 were invited to complete a second questionnaire 5-7 months after the first; 134 (70.2%) complied. Total agreement on whether patients satisfied each of seven case definitions ranged from 80% to 90%. After adjustment for chance, major agreement was observed for three of the seven case definitions (kappa = 0.69, 0.68, and 0.78). The survey achieved good reproducibility regarding self-report of symptoms described in published case definitions of environmental sensitivity.

Adolescent↗

PubMed2001

Environmental sensitivities: prevalence of major symptoms in a referral center: the Nova Scotia Environmental Sensitivities Research Center Study.

Although the phenomenon of environmental sensitivities (ES) has no clear etiology nor well-accepted pathophysiology, affected individuals experience symptoms that cause varying levels of dysfunction. Through a dedicated, government-funded research and treatment center, a detailed questionnaire covering 217 symptoms in 13 systems was mailed in 1997-1998 to 812 individuals referred to the center by physicians. A total of 385 (47%) questionnaires were returned, and data were analyzed on 351 individuals. Participants tended to be women (80%), middle-aged individuals (37% age 40-49 years), and those in higher educational groups (28% completed university), but there was wide variation in demographic variables. General symptoms such as difficulty concentrating, fatigue, forgetfulness, and irritability dominated the overall prevalence of symptoms since the start of their illness. Those related to irritation such as sneezing, itchy or burning eyes, and hoarseness or loss of voice were more common after exposure to environmental irritants. Ranking of symptoms using severity scores was consistent between men and women. Overall scores were higher in women, in participants who were separated or divorced, and in low-income groups. The type and consistency of symptoms experienced after exposure to triggering substances may not fit a purely psychogenic theory.

Adolescent↗

PubMed2005

Automated classification of an environmental sensitivity index.

Environmental Sensitivity Indices (ESI) composed of many field-data are essential for monitoring and control systems. At the beginning of the last decade an ESI of the German Wadden Sea was developed for use by the relevant authorities. This ESI was derived by experts semi-manually analysing the extensive field data-set. An algorithm is presented here which emulates human expert-decisions on the classification of sensitivity classes. This will permit the necessary regular updates of ESI-determination when new field data become available using automated classifications procedures. After tuning the algorithm parameters it generates decisions identical to those of human experts in about 97% of all locations tested. In addition, the algorithm presented also enables erroneous or extremely seldom field data to be identified.

Algorithms↗

PubMed2003

Environmental sensitivity.

The concept of environmental sensitivity is popular among a small group of physicians who believe that exposure to low levels of numerous environmental chemicals can cause a disease with numerous symptoms but no objective physical or laboratory abnormalities. The condition lacks a clear definition. Numerous theories that have been offered to explain the condition encompass immunotoxic, allergic, autoimmune, neurotoxic, cytotoxic, metabolic, behavioral, psychiatric, iatrogenic, and sociologic mechanisms. Environmental sensitivity has many features in common with other controversial syndromes, such as the chronic fatigue syndrome. Patients with environmental sensitivity frequently are subjected to unproven and unnecessary diagnostic tests and therapeutic modalities. In spite of the lack of physical illness and absence of pathology, patients often experience extreme disability, because their symptoms are triggered by common environmental exposures. The phenomenon of environmental sensitivity needs to be evaluated critically using scientifically sound methods. The practice of clinical ecology encompasses the practices of environmental sensitivity and its theories. Most methods of diagnosis and treatment have been disproved, and the concepts underlying these theories are not scientific. Alternative means of diagnosis and management are presented.

Environmental Illness↗

PubMed2000

Impact of environmental sensitivity on occupational performance.

Environmental sensitivity is a multi-system disorder characterized by adverse reactions to certain foods, chemicals, and environmental agents. In this study, the impact of environmental sensitivity on the person, environment, and occupation, as well as on occupational performance and time use, was determined. Using qualitative methods, 12 participants with environmental sensitivity were interviewed during a 2-month period. A time-use diary of activities over a 24-hour period was obtained and compared with a survey conducted by Statistics Canada. Textual analysis was conducted by examining and coding data for emerging themes. Finally, the data were interpreted using the Person-Environment-Occupation Model (Law et al., 1996). Findings suggest a multiple-system involvement that leads to changes in type, time, and location of self-care, productive, and leisure occupations. Changes to personal health, environment, and occupations contributed to a decline in occupational performance. Enabling and constraining factors influenced the adaptation to changes in occupational performance. Emerging themes included an initial struggle for legitimacy, societal stigma, isolation, financial strain, and loss of personal expression. Management of environmental sensitivity involved making personal, environmental, and occupational changes. Possible roles for occupational therapists encompass issues of pacing, energy conservation, environmental changes, job modification, and matching occupational interests with personal abilities.

Activities of Daily Living↗

PubMed2003

Estimation of environmental sensitivity of genetic merit for milk production traits using a random regression model.

The objective of this study was to estimate effects of environmental sensitivity of milk production traits for several environmental parameters and to investigate the impact of combining traits with different environmental sensitivity in an economic index. Variance components and breeding values were estimated for milk, fat, and protein yield, and fat and protein percentage by applying a random regression on values of an environmental parameter for each sire. Fourteen environmental parameters were defined and fitted to data consisting of 151,696 heifers in 6780 herds in The Netherlands with first-lactation records for milk production, somatic cell count, body condition score, and number of inseminations. Milk, fat, and protein yield showed environmental sensitivity in combination with 12 environmental parameters. Herd-year averages of protein, body condition score, age at calving, calving interval, and peak date of calving explained most genotype by environment interaction, mainly resulting from scaling effects. Almost all genetic correlations across environments were 0.99 or higher. Although heterogeneity of genetic variances was considerable, heterogeneity of heritabilities was limited. Scaling had a large effect on the weights of the economic index, but environmental sensitivities of milk, fat, and protein yields were approximately of equal magnitude. Consequently, very little reranking occurred based on the economic index.

Animals↗

PubMed1975

Determination of the environmental sensitivity of selection lines by the selection environment.

The parents chosen to continue 10 independent selection lines of Schizophyllum commune over eight successive generations of selection, along with unselected controls, have been retrospectively examined for their response to growth at 15 degrees, 20 degrees, 25 degrees, 30 degrees and 35 degrees C. The regression of rate of growth on temperature was essentially linear over the range 15 degrees to 30 degrees C for all lines in all generations as was also the regression of rate of growth on various biological assessments of the environments over the whole temperature range. Either regression, therefore, provided linear regression coefficients which adequately accounted for the relative sensitivities of the lines to temperature in each generation of selection. These measures of environmental sensitivity confirmed our earlier report that selection for high mean performance in a good environment or for low mean performance in a poor environment leads to selections that are more sensitive to environmental variation than selections for high mean performance in a poor environment or for low mean performance in a good environment. These differences in sensitivity emerge as correlated responses during selection and the magnitude of these correlated responses is higher in the good environment than in the poor environment irrespective of the direction of selection. The environmental sensitivity of selection lines can be modified in either direction as required by either selecting for sensitivity simultaneously with the selection for mean performance or by selecting for mean performance in an above or below average environment. The quality of environments in which artificial selection is usually carried out is likely to have led to high selections with maximum environmental sensitivity and low selections with minimum sensitivity.

Environment↗

PubMed2005

Sex and environmental sensitivity in blue tit nestlings.

In birds and mammals with sexual size dimorphism (SSD), the larger sex is typically more sensitive to adverse environmental conditions, such as food shortage, during ontogeny. However, some recent studies of altricial birds have found that the larger sex is less sensitive, apparently because large size renders an advantage in sibling competition. Still, this effect is not an inevitable outcome of sibling competition, because several studies of other species of altricial birds have found the traditional pattern. We investigated if the sexes differ in environmental sensitivity during ontogeny in the blue tit, a small altricial bird with c. 6% SSD in body mass (males larger than females). We performed a cross-fostering and brood size manipulation experiment during 2 years to investigate if the sexes were differently affected as regards body size (body mass, tarsus and wing length on day 14 after hatching) and pre-fledging survival. We also investigated if the relationship between body size and post-fledging survival differed between the sexes. Pre-fledging mortality was higher in enlarged than in reduced broods, representing poor and good environments, respectively, but the brood size manipulation did not affect the mortality rate of males and females differently. In both years, both males and females were smaller on day 14 after hatching in enlarged as compared to reduced broods. In one of the years, we also found significant Sex x Experiment interactions for body size, such that females were more affected by poor environmental conditions than that of males. Body size was positively correlated with post-fledging survival, but we found no interactive effects of sex and morphological traits on survival. We conclude that in the blue tit, females (the smaller sex) are more sensitive to adverse environmental conditions which, in our study, was manifest in terms of fledgling size. A review of published studies of sex differences in environmental sensitivity in sexually size-dimorphic altricial birds suggests that the smaller sex is more sensitive than the larger sex in species with large brood size and vice versa.

Animals↗

PubMed2002

Crystal structure of venus, a yellow fluorescent protein with improved maturation and reduced environmental sensitivity.

Yellow emission variants of green fluorescent protein (GFP) have been found useful in a variety of applications in biological systems due to their red-shifted emission spectrum and sensitivity to environmental parameters, such as pH and ionic strength. However, slow maturation properties and new requirements for more intense fluorescence necessitated further mutagenesis studies of these proteins. Venus, a new variant with improved maturation and brightness, as well as reduced environmental dependence, was recently developed by introducing five mutations into the well characterized variant, enhanced yellow fluorescent protein (EYFP). In this paper, we present the crystal structure of Venus at 2.2 A resolution, which enabled us to correlate its novel features with these mutation points. The rearrangement of several side chains near the chromophore, initiated by the F46L mutation, was found to improve maturation at 37 degrees C by removing steric and energetic constraints, which may hinder folding of the polypeptide chain, and by accelerating the oxidation of the Calpha-Cbeta bond of Tyr(66) during chromophore formation. M153T, V163A, and S175G were also found to improve the rate of maturation by creating regions of greater flexibility. F64L induced large conformational changes in the molecule, leading to the removal of halide sensitivity by preventing ion access to the binding site.

Amino Acid Sequence↗

PubMed1996

Internal complexity and environmental sensitivity in hospitals.

Theory suggests that organizations should respond to external complexity with internal complexity. We examine whether "environmentally sensitive" hospitals are more internally complex than "environmentally insensitive" hospitals. Results show that environmentally sensitive and insensitive hospitals differed on three of the measures of internal complexity: goal complexity, strategic complexity, and relational complexity.

Chief Executive Officers, Hospital↗

PubMed2003

A quantitative methodology for indexing environmental sensitivity and pollution potential.

A methodology for rating the suitability of sites for the location of industrial facilities is formulated and applied to the case of a coal-fired power plant location. The methodology comprises two major interlinked components: the environmental plant location indexing component, which involves the identification, scaling and weighting of environmental sensitivity factors; and the impact analysis component, which involves the superimposition of the pollution generation impacts of an industrial facility on spatially gridded zones of various environmental sensitivities. For each rectangular areal unit defined by a square grid, the Unit Pollution Potential Index is determined by the severity and distribution of key environmental sensitivity factors and the coverage of superimposed pollutant effects as determined by contaminant fate and transport models. For any alternative site of a planned facility, the summation of the unit indices over the area of influence of the facility provides the quantitative Pollution Index, which can be used as a basis for comparison of alternative sites for planned facilities. For this paper, this methodology is applied to the hypothetical case of the siting of a coal-fired power plant in the northeastern region of the United States, in which three alternative sites are considered. The three sites: A, B and C yielded indices of 47.83, 47.91 and 47.6, respectively, indicating that site C is the most suitable for siting the power plant.

Coal↗

PubMed2006

Environmental sensitivity: equivocal illness in the context of place.

This article presents a phenomenologically oriented description of the interaction of illness experience, social context, and place. This is used to explore an outbreak of environmental sensitivities in Nova Scotia, Canada. Environmental Sensitivity (ES) is a popular designation for bodily reactions to mundane environmental stimuli that are insignificant for most people. Mainstream medicine cannot support the popular models of this disease process and consequently illness experience is subject to ambiguity and contestation. As an 'equivocal illness', ES generates considerable social action around the nature, meaning and validity of suffering. Sense of place plays an important role in this process. In this case, the meanings that accrue to illness experience and that produce salient popular disease etiology are grounded in the experience and social construction of the Nova Scotian landscape over time. Shifting representations of place are reflected in illness experience and the meanings that arise around illness are emplaced in landscape.

Attitude↗

PubMed1996

Spectral properties of environmentally sensitive probes associated with horseradish peroxidase.

The environmentally sensitive fluorescent probes 6-propionyl-2-(N,N-dimethylamino)naphthalene (PRODAN) and 2'-(N,N-dimethylamino)-6-naphthoyl-4-trans-cyclohexanioc acid (DANCA) form complexes with the heme binding site of apohorseradish peroxidase. The dissociation constants of the PRODAN and DANCA complexes were determined from anisotropy titration data to be approximately 8.7 x 10(-5) and 3.3 x 10(-4) M, respectively. From comparison of the steady state fluorescence spectra of PRODAN and DANCA in solvents of varying dielectric constants, and in the apohorseradish peroxidase complex, we conclude that the heme binding site of horseradish peroxidase is relatively polar. The lifetimes of PRODAN and DANCA in organic solvents of varying polarities can be fit to single exponential decays. However, the lifetimes of PRODAN and DANCA associated with apohorseradish peroxidase, determined using a background subtraction method to correct for the non-negligible fluorescence of unbound probe, fit best to a distribution of lifetime values. We attribute these lifetime distributions to microenvironmental heterogeneity which is also consistent with the observed dependence of the emission maxima of PRODAN-apohorseradish peroxidase upon the excitation wavelength. In neither the PRODAN nor the DANCA case was evidence found in the time-resolved data for relaxation of the protein matrix around the excited state probe dipole.

2-Naphthylamine↗

PubMed2005

Dietary practices of women diagnosed with environmental sensitivity.

PURPOSE: Food avoidance is central to the treatment of environmental sensitivity (ES), a chronic, often debilitating, multisystem disorder characterized by adverse reactions to non-noxious levels of environmental substances. Because prolonged food avoidance could impact nutritional health, the purpose of this research was to assess adequacy and quality of diets consumed by women diagnosed with ES. METHODS: Twelve women aged 37 to 50 recruited from the Nova Scotia Environmental Health Clinic completed a four-day food record during the spring and summer of 1998. RESULTS: When adequacy of nutrient intake was assessed by comparison to the Estimated Average Requirement, the most limited nutrients in the diet were folate, vitamin B6, vitamin B12, and magnesium. Only one woman exceeded the Adequate Intake for calcium. When diet quality was assessed using the Healthy Eating Index, the majority of women (75%) scored in the "needs improvement" category; intake of milk and dietary variety scored the lowest. Women consumed very few servings from "other foods", defined in the food guide as foods containing mostly sugar and mostly fat. CONCLUSIONS: The results of this study suggest that women diagnosed with ES would benefit from counselling on ways to increase dietary variety, which would lead to improved nutrient intake, and ways to increase calcium intake.

Adult↗

PubMed2005

Environmental sensitivity of gas exchange in different-sized trees.

The carbon isotope signature (delta13C) of foliar cellulose from sunlit tops of trees typically becomes enriched as trees of the same species in similar environments grow taller, indicative of size-related changes in leaf gas exchange. However, direct measurements of gas exchange in common environmental conditions do not always reveal size-related differences, even when there is a distinct size-related trend in delta13C of the very foliage used for the gas exchange measurements. Since delta13C of foliage predominately reflects gas exchange during spring when carbon is incorporated into leaf cellulose, this implies that gas exchange differences in different-sized trees are most likely to occur in favorable environmental conditions during spring. If gas exchange differs with tree size during wet but not dry conditions, then this further implies that environmental sensitivity of leaf gas exchange varies as a function of tree size. These implications are consistent with theoretical relationships among height, hydraulic conductance and gas exchange. We investigated the environmental sensitivity of gas exchange in different-sized Douglas-fir (Pseudotsuga menziesii) via a detailed process model that specifically incorporates size-related hydraulic conductance [soil-plant-atmosphere (SPA)], and empirical measurements from both wet and dry periods. SPA predicted, and the empirical measurements verified, that differences in gas exchange associated with tree size are greatest in wet and mild environmental conditions and minimal during drought. The results support the hypothesis that annual net carbon assimilation and transpiration of trees are limited by hydraulic capacity as tree size increases, even though at particular points in time there may be no difference in gas exchange between different-sized trees. Maximum net ecosystem exchange occurs in spring in Pacific Northwest forests; therefore, the presence of hydraulic limitations during this period may play a large role in carbon uptake differences with stand-age. The results also imply that the impacts of climate change on the growth and physiology of forest trees will vary depending on the age and size of the forest.

Carbon Dioxide↗

PubMed1998

Structure-based engineering of environmentally sensitive fluorophores for monitoring protein-protein interactions.

Single, extrinsic, environmentally sensitive fluorophores can be used to quantitate formation of protein-protein complexes. These can be prepared semi-synthetically by covalent coupling to single cysteine mutations introduced at positions where the fluorophore is predicted to respond to formation of the complex without adversely affecting the interaction. The three-dimensional structure of a protein-protein interface can be used to select such locations by identifying residues that are located at the edge of a buried interfacial region, and are in partial steric contact with both partners as indicated by a change in their static solvent-accessible surface area upon complex formation. Using this design approach, cysteine mutations were introduced into the B1 domain of protein G, which successfully monitor complex formation with minimal interference. Such constructs have great utility in the analysis of solution properties of interface mutants.

Base Sequence↗

PubMed1994

Generation and Characterization of Environmentally Sensitive Variants of the beta-Galactosidase from Lactobacillus delbrueckii subsp. bulgaricus.

A method is described for generating and screening variants of the beta-galactosidase from Lactobacillus delbrueckii subsp. bulgaricus sensitive to several environmental stresses, with potential application in the food industry. Chemical mutagenesis with hydroxylamine or methoxylamine was performed on the beta-galactosidase gene carried on an Escherichia coli expression vector. Mutants sensitive to cold, heat, low pH, low magnesium concentration, and the presence of urea were isolated by screening for reduced color development on beta-galactosidase indicator plates. The mutations responsible for three variant beta-galactosidases were localized, and the base substitutions were determined by DNA sequencing. The amino acid alterations associated with one low-pH-sensitive (pHs) and two urea-sensitive (Us) variants correspond to P584L (pHs1), G400S/R479Q (Us26), and G167E/E168K/E363K/V492M (Us17), respectively. Mutant pHs1 is also heat, cold, low magnesium, and urea sensitive; Us26 is also cold sensitive; and Us17 is also low-pH sensitive.

Journal Article↗

PubMed1988

Spectroscopic and functional characterization of an environmentally sensitive fluorescent actin conjugate.

Rabbit skeletal muscle F-actin has been selectively labeled at a cysteine residue with the environmentally sensitive fluorophore 6-acryloyl-2-(dimethylamino)naphthalene. The fluorescent actin conjugate behaves similarly to native actin with respect to the polymerization kinetics, critical monomer concentration, and ability to form F-actin paracrystals. Upon polymerization to F-actin, the absorption of the actin conjugate is red-shifted, whereas the fluorescence emission is blue-shifted 740 wavenumbers and is accompanied by a decrease in the fluorescence bandwidth of 470 wavenumbers. These large shifts in the spectral properties of 6-propionyl-2-(dimethylamino)naphthalene (Prodan) in actin provide a simple method for obtaining a spectral discrimination between the G- and F-actin populations during the polymerization reaction. Steady-state fluorescence techniques were used to study the environment of the fluorophore in the monomeric and polymeric forms of actin. Fluorescence emission spectral analysis and quenching and polarization studies of G-actin-Prodan indicated that the fluorophore lies immobile on the protein surface but with one of its faces in full contact with the solvent. In F-actin, the fluorophore has a limited exposure to the solvent and is located in a dielectric environment similar to those seen for Prodan in polar, aprotic solvents or buried within a protein matrix [Macgregor, R. B., Jr., & Weber, G. (1986) Nature (London) 318, 70-73]. Additionally, our results demonstrate that the Prodan molecule conjugated to F-actin is completely immobile during its fluorescence lifetime, exhibits an increase in the resonance energy transfer (RET) from tryptophan residues compared to that observed in G-actin, and shows evidence of homologous RET within the polymer.

2-Naphthylamine↗