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At least 451 records · Page 25Linked to original sources

PubMed2006

Differential effects of clorgyline on sensitization to quinpirole in rats tested in small and large environments.

RATIONALE: Cotreatment with clorgyline shifts the development of sensitization to the D2/D3 dopamine receptor agonist quinpirole from locomotion to mouthing, an effect apparently unrelated to the monoamine oxidase inhibition property of clorgyline. This phenomenon was demonstrated in rats examined in small activity chambers. However, like with other psychostimulant drugs, sensitization to quinpirole is modulated by environmental context. It is not known whether the clorgyline cotreatment effect is likewise influenced by the environment. OBJECTIVE: To determine the generality of the clorgyline effect on behavioral sensitization by evaluating the effects of clorgyline cotreatment on sensitization to quinpirole in two different environments: a small activity chamber and a large open field. METHODS: Male rats received eight injections of quinpirole (0.5 mg/kg, twice weekly) in an open field or activity chamber; one group in each environment received a constant infusion of clorgyline (1 mg/kg/day via osmotic minipumps) while the other group served as the sham surgery control. For quinpirole injection 7 or 8, rats were tested in the alternate environment. RESULTS: In activity chambers, clorgyline cotreatment switched sensitization to quinpirole from locomotion to mouthing. In the open field, clorgyline cotreatment increased mouthing and expanded the explored space without a change in path stereotypy or the amount of locomotion compared to treatment with quinpirole alone. CONCLUSIONS: Structure of the environment can modulate the clorgyline cotreatment effect on behavioral sensitization to quinpirole. The behavioral profiles produced by clorgyline cotreatment in the two environments resembled the behavioral effects observed with quinpirole and D1 agonist cotreatment. It is suggested that clorgyline cotreatment produces a behavioral profile characteristic of enhanced dopamine D1 and D2 receptor costimulation.

Animals↗

PubMed2006

Learning about environments: the significance of primal landscapes.

The way we learn about our environments--be they farms, forests, or tribal lands--has implications for the formulation of environmental policy. This article presents the findings of how residents learned about their environments in two rural case studies conducted in northern Queensland and relates these to the concept of "primal landscapes," which is concerned with the interaction that occurs between children and the environments in which they mature. Rather than focusing specifically on built environments or natural environments, the article draws on an approach that conceptualizes environment as meaning-laden places in which we live and work, which integrate social, cultural, biological, physical, and economic dimensions. In drawing insights for environmental policy, the article draws attention to the timing of policy interventions, the significance of experiential environmental education, the potential to learn from place-based festivals, and the importance of learning from extreme events such as fires and floods.

Child↗

PubMed2005

Evolution in heterogeneous environments and the potential of maintenance of genetic variation in traits of adaptive significance.

The maintenance of genetic variation in traits of adaptive significance has been a major dilemma of evolutionary biology. Considering the pattern of increased genetic variation associated with environmental clines and heterogeneous environments, selection in heterogeneous environments has been proposed to facilitate the maintenance of genetic variation. Some models examining whether genetic variation can be maintained, in heterogeneous environments are reviewed. Genetic mechanisms that constrain evolution in quantitative genetic traits indicate that genetic variation can be maintained but when is not clear. Furthermore, no comprehensive models have been developed, likely due to the genetic and environmental complexity of this issue. Therefore, I have suggested two empirical approaches to provide insight for future theoretical and empirical research. Traditional path analysis has been a very powerful approach for understanding phenotypic selection. However, it requires substantial information on the biology of the study system to construct a causal model and alternatives. Exploratory path analysis is a data driven approach that uses the statistical relationships in the data to construct a set of models. For example, it can be used for understanding phenotypic selection in different environments, where there is no prior information to develop path models in the different environments. Data from Brassica rapa grown in different nutrients indicated that selection changed in the different environments. Experimental evolutionary studies will provide direct tests as to when genetic variation is maintained.

Adaptation, Biological↗

PubMed1984

Symposium on infectious complications of neoplastic disease (Part II). Protected environments are discomforting and expensive and do not offer meaningful protection.

An environment that is germ free and a patient who is germ free have been goals in managing immunocompromised patients, especially those who are neutropenic. Such a germ-free environment, inside and out, can be achieved in laboratory animals after considerable manipulation, including delivery by cesarean section. This is rarely indicated or achieved in humans, but investigators have tried to decrease the numbers of organisms on the outside of patients (both environmental and on the skin) and to do the same with the inside--or at least to selectively decrease the organisms most likely to invade from mucous membranes and the gastrointestinal tract. Most studies of protected environments have included patients who receive prophylactic oral nonabsorbable antibiotics, prophylactic systemic antibiotics, or oral absorbable antibiotics (selective decontamination). Another variable that needs to be considered is the use of sterile food--included in some studies, not used in others, and not mentioned in still others. No studies have used the only appropriate control, which is the same laminar airflow room, but with the airflow turned off and without gowns, masks, or gloves, only assiduous hand-washing. The same staff should care for the control patients as well as those in protected environments. In addition, control patients in some studies have been clearly different in the severity of the underlying disease from patients placed in protected environments. Even without these proper controls, differences in infection rates have varied considerably among the studies both inside and outside the protected environment and efficacy has also varied considerably; however, the one constant in almost every controlled study is that life has not been prolonged, remission induction increased, nor remission duration prolonged.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗

PubMed1978

Social grouping cannot account for cerebral effects of enriched environments.

Several experiments were conducted to test whether, as suggested by Welch et al. in this journal, mere group living (social stimulation) can account for the significant differences in measures of brain anatomy and brain chemistry that develop between rodents housed in groups in enriched environments and rodents housed singly in restricted environments; the alternative hypothesis was that features of the inanimate environment can significantly affect brain measures of animals living in a social group. Groups of 12 male rats were assigned for 30 days to several types of environment: (a) large cage without stimulus objects, (b) large cage containing varied stimulus objects, (c) large cage containing a maze whose pattern of barriers was changed daily, and (d) a seminatural outdoor environment; in each experiment, littermates of rats in the social conditions were housed in isolation in small colony cages. At the end of the 30-day period, measures were taken of weights of brain regions, RNA and DNA contents of regions of cerebral cortex, and acetylcholinesterase activities of brain regions. Although the number of rats housed together was constant for conditions a--d and cage size was constant for conditions a--c, the magnitudes of the cerebral measures varied significantly as a function of the inanimate stimulus conditions. The differences from isola;ion-housed littermates was greatest in condition d and smallest in condition a. Thus, social grouping alone is inadequate to explain the cerebral effects of enriched environments and the inanimate stimulus conditions must be taken into account.

Acetylcholinesterase↗

PubMed2004

Family of origin environments in two clinical samples of survivors of intra-familial, extra-familial, and both types of sexual abuse.

OBJECTIVE: It has been suggested that survivors of ongoing childhood sexual abuse (CSA) tend to have been reared in ineffective family environments that render them particularly vulnerable to maltreatment and which foster psychological difficulties beyond those accounted for solely by their abuse. If this conjecture is valid, one would expect that the family of origin environments of CSA survivors would be disturbed whether their abuser was intra-familial or extra-familial. To assess this hypothesis, two studies compared the childhood family of origin environments and supportive parenting characteristics of a clinical sample of women sexually abused by family members only (the intra-familial group), by non-family members only (the extra-familial group), and by both family and non-family members (the "both" group). METHOD: Study 1 compared the three groups (total N = 213) using the Family Environment Scale (FES). Study 2 compared groups (total N = 86) on the positive parenting scales of the Exposure to Abusive and Supportive Environments Parenting Inventory (EASE-PI). RESULTS: In Study 1, multivariate analyses indicated significant differences on the independence, cohesion, and conflict subscales of the FES. Pairwise comparisons revealed that the extra-familial group reported significantly higher levels of family independence and lower levels of conflict than the other two groups. In addition, the extra-familial group reported higher levels of cohesion than the intra-familial group. However, the effect sizes of these comparisons were extremely small. In Study 2, multivariate analyses revealed no group differences on the EASE-PI scales. CONCLUSIONS: Low effect sizes on the three significant FES scales, non-significance on the remaining seven FES scales, and non-significance on the EASE-PI scales suggest that there is considerable similarity in the family of origin environments of adult female CSA survivors seeking therapy regardless of whether their perpetrators were family members, non-family members, or both family and non-family members.

Adult↗

PubMed2004

Family environment of eating disordered patients with and without self-injurious behaviors.

OBJECTIVE: The family environment is known to be an important contributor to the course of psychiatric disorders. In this study, we examined the family context of eating disordered (ED) patients with and without self-injurious behaviors (SIB). METHOD: A Dutch adaptation of the Family Environment Scale "Sci Eng 57(9-B):1997;5927" was completed by 131 ED patients of whom 47% showed at least one form of SIB (e.g., cutting, burning, hair pulling, etc.). RESULTS: Results showed a significant difference in family environment between patients with and without SIB. The family environment of self-injuring ED patients was less cohesive, expressive and socially oriented, and more conflictual and disorganized than the family environment of those without SIB. No significant differences in perceived family environment were found with respect to the number or form of SIB and the subtype of ED. Neither did we find a significant interaction effect between ED subtype and presence/absence of SIB.

Adult↗

PubMed2004

Genetics, epigenetics, and the environment: switching, buffering, releasing.

Increasing evidence suggests that the interactions between genes and environment might play a critical role in the pathogenesis of complex diseases, such as asthma, that exhibit a heritable component but do not follow Mendel's laws. Gene-environment interactions are extremely complex and not linear, such that the same genetic variants might be associated with opposite phenotypes in different environments. This is particularly evident for innate immunity genes, which operate at the interface between the immune system and the pathogen world. This article examines gene-environment interactions by using CD14 as a model and argues that the conflicting results of epidemiologic studies on CD14*C-159T result from differences in environmental conditions essential to modulate CD14 gene expression. Furthermore, on the basis of how rapidly environmental changes have affected the incidence of immune diseases, I argue that a full understanding of gene-environment interactions requires that epigenetic as well as classical genetic mechanisms be taken into account. Recent data about the effect of diet on gene methylation and the release of hidden genetic variation by impairment of heat shock protein 90-mediated buffering systems offer eloquent examples of how epigenetic mechanisms might affect gene-environment interactions.

DNA Methylation↗

PubMed1999

Unipedal balance in healthy adults: effect of visual environments yielding decreased lateral velocity feedback.

OBJECTIVE: To test the (null) hypotheses that the reliability of unipedal balance is unaffected by the attenuation of visual velocity feedback and that, relative to baseline performance, deterioration of balance success rates from attenuated visual velocity feedback will not differ between groups of young men and older women, and the presence (or absence) of a vertical foreground object will not affect balance success rates. DESIGN: Single blind, single case study. SETTING: University research laboratory. PARTICIPANTS: Two volunteer samples: 26 healthy young men (mean age, 20.0yrs; SD, 1.6); 23 healthy older women (mean age, 64.9 yrs; SD, 7.8). MAIN OUTCOME MEASURE: Normalized success rates in unipedal balance task. METHODS: Subjects were asked to transfer to and maintain unipedal stance for 5 seconds in a task near the limit of their balance capabilities. Subjects completed 64 trials: 54 trials of three experimental visual scenes in blocked randomized sequences of 18 trials and 10 trials in a normal visual environment. The experimental scenes included two that provided strong velocity/weak position feedback, one of which had a vertical foreground object (SVWP+) and one without (SVWP-), and one scene providing weak velocity/strong position (WVSP) feedback. Subjects' success rates in the experimental environments were normalized by the success rate in the normal environment in order to allow comparisons between subjects using a mixed model repeated measures analysis of variance. RESULTS: The normalized success rate was significantly greater in SVWP+ than in WVSP (p = .0001) and SVWP- (p = .013). Visual feedback significantly affected the normalized unipedal balance success rates (p = .001); neither the group effect nor the group X visual environment interaction was significant (p = .9362 and p = .5634, respectively). Normalized success rates did not differ significantly between the young men and older women in any visual environment. CONCLUSIONS: Near the limit of the young men's or older women's balance capability, the reliability of transfer to unipedal balance was adversely affected by visual environments offering attenuated visual velocity feedback cues and those devoid of vertical foreground objects.

Adult↗

PubMed1999

Access to the environment and life satisfaction after spinal cord injury.

OBJECTIVE: To determine the potential relation between satisfaction with life after spinal cord injury and access to the environment as measured by selected items from the Craig Handicap Assessment and Reporting Technique (CHART). DESIGN: Prospective, correlational/predictive study using cross-sectional and longitudinal data from 18 Model Spinal Cord Injury Systems of Care. SUBJECTS: Adult persons with traumatic-onset spinal cord injury (n = 650) evaluated at 1 or 2 years postinjury. OUTCOME MEASURE: Satisfaction With Life Scale (SWLS). PREDICTOR VARIABLES: Demographic characteristics, impairment and disability classifications. medical complications, rehabilitation insurance status, occupational status as measured by the CHART Occupation Scale, self-perceived health (from SF-36), and access to the environment as measured by items from the CHART Mobility Scale. RESULTS: Access to the environment was positively and linearly associated with satisfaction with life, demonstrated both positive and negative change over time, and was positively associated with subject's neurologic status. Access to the environment added to the explanatory model to predict life satisfaction even after all other independent measures were accounted for. CONCLUSION: Access to the environment (an "outside the person" factor) is important in predicting satisfaction with life for persons with spinal cord injury. The measure of access to the environment developed here is promising and worthy of further exploration and expansion.

Activities of Daily Living↗

PubMed2001

Combining qualitative and quantitative methods in assessing hospital learning environments.

Clinical education is a vital component in the curricula of pre-registration nursing courses and provides student nurses with the opportunity to combine cognitive, psychomotor, and affective skills. Clinical practice enables the student to develop competencies in the application of knowledge, skills, and attitudes to clinical field situations. It is, therefore, vital that the valuable clinical time be utilised effectively and productively. Nursing students' perception of the hospital learning environment were assessed by combining quantitative and qualitative approaches. The Clinical Learning Environment Inventory, based on the theoretical framework of learning environment studies, was developed and validated. The quantitative and qualitative findings reinforced each other. It was found that there were significant differences in students' perceptions of the actual clinical learning environment and their preferred learning environment. Generally, students preferred a more positive and favourable clinical environment than they perceived as being actually present.

Attitude of Health Personnel↗

PubMedDate not supplied

Long-term neurobehavioural impact of the postnatal environment in rats: manipulations, effects and mediating mechanisms.

The major characteristics of the postnatal environment of the rat pup are its mother and littermates. The pup, which is poorly developed at birth, matures rapidly in this environment, and regulates the behaviour and physiology of the dam and littermates, as well as vice versa. The study of the impact of the rat's postnatal environment on its long-term neurobehavioural development is of fundamental importance. In fact, it is one of the major examples--at the interface of the biological, social and medical sciences--of animal models for the study of the interaction between the environment and the genome in both the acute and chronic regulation of the phenotype. Specific experimental manipulations of the rat postnatal environment have been demonstrated to exert robust and marked effects on neurobiological, physiological and behavioural phenotypes in adulthood. In the present review we present some of the major findings, including some original data, and discuss what these existing data can tell us about the long-term neurobehavioural effects of the postnatal environment in rats, the external and internal mechanisms that mediate these effects, and the most appropriate directions for future basic and applied research in this area.

Animals↗

PubMed2004

A common approach for radiological protection of humans and the environment.

Protection of the environment is developing rapidly at the national and international level, but there are still no internationally agreed recommendations as to how radiological protection of the environment should be carried out. The International Commission on Radiological Protection (ICRP) is currently reviewing its existing recommendations for human protection. It has set up a task group with the aim of developing a protection policy for, and suggesting a framework of, the protection of the environment that could feed into its recommendations at the start of the 21st century. The task group will propose a framework for the protection of the environment from harmful effects of radiation, harmonising with the principles for the protection of humans. Although the task group has not yet finalised on the objectives for the environment, these might be to safeguard the environment by preventing or reducing the frequency of effects likely to cause early mortality, reduced reproductive success, or the occurrence of scorable DNA damage in individual fauna and flora to a level where they would have a negligible impact on conservation of species, maintenance of biodiversity, or the health and status of natural habitats or communities. To achieve these objectives, a set of reference dose models, reference dose per unit intake and reference organisms will be required.

Animals↗

PubMed2002

Complexity of sensory environment drives the expression of candidate-plasticity gene, nerve growth factor induced-A.

Exposure of animals to an enriched environment triggers widespread modifications in brain circuitry and function. While this paradigm leads to marked plasticity in animals chronically or acutely exposed to the enriched environment, the molecular mechanisms that enable or regulate such modifications require further characterization. To this end, we have investigated the expression profiles of both mRNA and protein products of a candidate-plasticity gene, nerve growth factor induced-A (NGFI-A), in the brains of rats exposed to increased environmental complexity. We found that NGFI-A mRNA is markedly up-regulated throughout the brains of animals exposed to the enriched environment, but not in the brains of either handled-only or undisturbed control groups. The most pronounced effects were observed in the somatosensory and visual cortices, in layers III and V, while more modest increases were observed in all other cortical layers, with the exception of layer I. A striking NGFI-A mRNA up-regulation was also observed in the striatum and hippocampal formation, notably in the CA1 subfield, of animals exposed to the enriched environment paradigm. Immunocytochemistry was also used to investigate the distribution of NGFI-A protein in response to the environmental enrichment protocol. A marked increase in the number of NGFI-A positive nuclei was identified in the enriched environment condition, as compared to undisturbed and handled-only controls, throughout the rat brain. While the greatest number of NGFI-A immunolabeled neurons was found in cortical layers III and V, up-regulation of NGFI-A protein was also detectable in layers II, IV and VI, in both the somatosensory and visual cortices. NGFI-A immunopositive neurons were also more numerous in the CA1 subfield of the hippocampal formation of animals exposed to the enriched environment, but remained at basal levels in both control groups. Our results implicate NGFI-A as one of the possible early genetic signals that ultimately lead to plastic changes in the CNS.

Animals↗

PubMed2003

Effects of postischemic environment on transcription factor and serotonin receptor expression after permanent focal cortical ischemia in rats.

Housing rats in an enriched environment improves functional outcome after ischemic stroke, this may reflect neuronal plasticity in brain regions outside the lesion. Which components of the enriched environment that are of greatest importance for recovery after brain ischemia is uncertain. We have previously found that enriched environment and social interaction alone both improve functional recovery after focal cerebral ischemia, compared with isolated housing with voluntary wheel-running. In this study, the aim was to separate components of the enriched environment and investigate the effects on some potential mediators of improved functional recovery; such as the inducible transcription factors nerve growth factor-induced gene A (NGFI-A) and NGFI-B, and the glucocorticoid and serotonin systems. After permanent middle cerebral artery occlusion, rats were divided into four groups: individually housed with no equipment (deprived group), individually housed with free access to a running wheel (running group), housed together in a large cage with no equipment (social group) or in a large cage furnished with exchangeable bars, chains and other objects (enriched group). mRNA expression of inducible transcription factors, serotonin and glucocorticoid receptors was determined with in situ hybridisation 1 month after cerebral ischemia. Rats housed in enriched or social environments showed significantly higher mRNA expression of NGFI-A and NGFI-B in cortical regions outside the lesion and in the CA1 (cornu ammonis region of the hippocampus), compared with isolated rats with or without a running wheel. NGFI-A and NGFI-B mRNA expression in cortex and in CA1 was significantly correlated to functional outcome. 5-Hydroxytryptamine receptor 1A (5-HT(1A)) mRNA expression and binding, as well as 5-HT(2A) receptor mRNA expression were decreased in the hippocampus (CA4 region) of the running wheel rats. Mineralocorticoid receptor gene expression was increased in the dentate gyrus amongst wheel-running rats. No group differences were found in plasma corticosterone levels or mRNA levels of glucocorticoid receptor, corticotropin-releasing hormone, 5-HT(2C) or c-fos. In conclusion, we have found that social interaction is a major component of the enriched environment regarding the effects on NGFI-A and NGFI-B expression. These transcription factors may be important mediators of improved functional recovery after brain infarctions, induced by environmental enrichment.

Animals↗

PubMed2002

Environment associated with morphine and experience of aggression modulate behaviors of postdependent mice.

Contexts associated with drug use can acquire secondary reinforcing properties. Furthermore, context-specific withdrawal has been observed to reflect a relatively long-lasting learned response. The aim of this study was to evaluate the effect of the environment paired with morphine after 15 days of abstinence. In the first experiment, isolated male mice received saline or morphine either in their home cage or in the distinctive environment, performing two agonistic encounters in the distinctive environment during spontaneous withdrawal. Similar groups were assigned but without aggression encounters during withdrawal. In the second experiment, animals received saline or morphine as previously described but suffered two naloxone-induced withdrawals during agonistic encounters. In all cases, after the second withdrawal, animals were drug-free during 15 days and then an aggression test took place in the distinctive environment. Results show that experience of aggression during this spontaneous withdrawal causes an increase in the level of aggression exhibited when animals are drug free, in comparison with others in which this experience does not exist. Environment associated with morphine administration decreases conditioned physical signs of withdrawal and to a smaller extent aggression. It could be suggested that environment associated with morphine administration decreases the abnormal behaviors exhibited in postdependent mice.

Agonistic Behavior↗

PubMed2002

Exploring the effect of the environment on physical activity: a study examining walking to work.

BACKGROUND: Research on physical activity and the physical environment is at the correlates stage, so it is premature to attribute causal effects. This paper provides a conceptual approach to understanding how the physical design of neighborhoods may influence behavior by disentangling the potential effects of income, university education, poverty, and degree of urbanization on the relationship between walking to work and neighborhood design characteristics. METHODS: The study merges Canadian data from 27 neighborhood observations with information on walking to work from the 1996 census. Hierarchical linear modeling was used to create a latent environment score based on 18 neighborhood characteristics (e.g., variety of destinations, visual aesthetics, and traffic). The relationship between the environment score and walking to work was modeled at the second level, controlling for income, university education, poverty, and degree of urbanization. RESULTS: With the exceptions of visual interest and aesthetics, each neighborhood characteristic contributed significantly to the environment score. The environment score was positively associated with walking to work, both with and without adjustment for degree of urbanization. Controlling for university education, income, and poverty did not influence these relationships. CONCLUSIONS: The positive association between the environment score and walking to work, controlling for degree of urbanization supports the current movement toward the development of integrated communities for housing, shops, workplaces, schools, and public spaces. Given the need for research to guide environmental interventions, collaboration among public health practitioners, urban planners, and transportation researchers is essential to integrate knowledge across sectors.

Adult↗

PubMed2002

Association of single-nucleotide polymorphisms at the Delta locus with genotype by environment interaction for sensory bristle number in drosophila Melanogaster.

The nature of forces maintaining variation for quantitative traits can only be assessed at the level of individual genes affecting variation in the traits. Identification of single-nucleotide polymorphisms (SNPs) associated with variation in Drosophila sensory bristle number at the Delta (Dl) locus provides us with the opportunity to test a model for the maintenance of variation in bristle number by genotype by environment interaction (GEI). Under this model, genetic variation is maintained at a locus under stabilizing selection if phenotypic values of heterozygotes are more stable than homozygotes across a range of environments, and the mean allelic effect is much smaller than the standard deviation of allelic effects across environments. Homozygotes and heterozygotes for two SNPs at Dl, one affecting sternopleural and the other abdominal bristle number, were reared in five different environments. There was significant GEI for both bristle traits. Neither condition of the model was satisfied for Dl SNPs exhibiting GEI for sternopleural bristle number. Heterozygotes for the abdominal bristle number SNPs were indeed the most stable genotype for two of the three environment pairs exhibiting GEI, but the mean genotypic effect was greater than the standard deviation of effects across environments. Therefore, this mechanism of GEI seems unlikely to be responsible for maintaining the common bristle number polymorphisms at Dl.

Abdomen↗