Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Interplay”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,783 records · Page 99Linked to original sources
PubMed2002

Risk factors for goiter and thyroid nodules.

The occurrence of thyroid diseases is determined by interplay between genetic and environmental factors. The major environmental factor that determines goiter prevalence is iodine status, but other environmental factors influencing entire populations have been identified such as goitrogens in food and drinking water. Less focus has been on individual environmental factors and the interplay between factors. The goiter prevalence is higher in certain groups in the population. The variation in goiter prevalence between the genders is well known with a higher occurrence among women. The association with age is probably dependent on iodine status, because it seems that the zenith of goiter prevalence appears earlier in life the more severe iodine deficiency the population is exposed to. The association with individual risk factors has been investigated in some studies, especially the association with tobacco smoking. In iodine-deficient areas, a strong association between tobacco smoking and goiter prevalence is found, whereas the association is less pronounced in iodine-replete areas. This was predictable from experimental studies showing thiocyanate to be the mediator of the goitrogenic effect of tobacco smoke acting as a competitive inhibitor of iodine uptake. The association with alcohol intake has only been investigated in few studies, but a low occurrence of goiter among alcohol consumers has been found. The mechanism of this association is not known. Increased goiter prevalence during pregnancy has been reported, and recently a long-term goitrogenic effect of pregnancies has also been shown. As demonstrated for tobacco smoking, this association is dependent on iodine status, because the association has only been found in areas with a suboptimal iodine intake. This indicates pregnancy-induced goiter to be the result of exacerbation of existing iodine deficiency. Recently, the use of oral contraceptives has been shown to be associated with a markedly reduced prevalence of goiter, although experimental studies have previously shown proliferative effects of estrogens on thyrocytes. Some implications for prevention of thyroid disease could be suggested. Discussion of smoking habits should be included in a consultation for goiter with a motivation to quit smoking. Iodine deficiency has particularly strong goitrogenic effects during pregnancy and for the sake of the mother as well as the fetus, sufficient iodine supply should be ensured to all pregnant women. The difference in age maximum in goiter prevalence suggests that monitoring of iodine deficiency disorders should ideally include a spectrum of age groups.

Female↗
PubMed2000

Ironing-out mechanisms of neuronal injury under hypoxic-ischemic conditions and potential role of iron chelators as neuroprotective agents.

Iron is the most abundant transition metal in the brain, where it functions as an important cofactor in a host of vital metabolic processes and plays an absolutely essential role in cell viability. Free iron is also very toxic when present in high concentrations, thus placing this essential metal at the core of neurotoxic injury in a number of neurological disorders. The pivotal role of iron in cellular homeostasis, including its latent toxicity, necessitates a tight regulation of iron metabolism. Oxygen and iron appear to play an important role in iron homeostasis. They appear to exert their homeostatic role by modulating the proteins involved in a complex interplay between iron sensing, transport, and storage. These key regulatory proteins include ferritin (intracellular storage), transferrin (extracellular transport), transferrin receptor, and iron regulatory protein (sensor of intracellular iron concentration). The interplay of iron and oxygen is most intriguing in the setting of stroke, where hypoxia and free iron appear to interact in causing the subsequent neuronal death.

Electrons↗
PubMed2007

Protein tyrosine phosphorylation and reversible oxidation: two cross-talking posttranslation modifications.

In addition to protein phosphorylation, redox-dependent posttranslational modification of proteins is emerging as a key signaling system, conserved throughout evolution, and influencing many aspects of cellular homeostasis. Recent data have provided new insight about the interplay between phosphorylation- and redox-dependent signaling, and reactive oxygen species have been included among intracellular signal transducers of growth factor and extracellular matrix receptors. Both tyrosine phosphorylation and thiol oxidation are reversible and dynamic, and this review will particularly focus on the cross-talk between these posttranslational protein regulatory means. Although these modifications share their reversibility, their effects on enzymatic activity of protein tyrosine phosphatases (PTPs) and protein tyrosine kinases (PTKs) may be even opposite. Indeed, while tyrosine phosphorylation is frequently correlated to enzyme activation, thiol oxidation leads to inactivation of PTPs and to superactivation of PTKs. Several papers describe that both these modifications occur during the same input, (i.e., cell proliferation and motility induced by numerous growth factors and cytokines). The review will discuss several aspects of phosphorylation\oxidation interplay, describing both convergent and divergent features of the integrated and coordinated function of PTPs and PTKs during signaling.

Animals↗
PubMed2005

Mouse models for the genetic study of tuberculosis susceptibility.

Tuberculosis, mainly caused by the pathogenic bacterium Mycobacterium tuberculosis, remains an inestimable public health problem, despite the established use of the Bacillus Calmette-Guerin (BCG) vaccine, multidrug therapy and the existence of global tuberculosis control programmes. Statistics show that nearly 2 billion people (approximately one-third of the world's population) are infected with M. tuberculosis. For unknown reasons, only about 10 per cent of those infected by M. tuberculosis will develop tuberculosis, resulting in 9 million new cases yearly and 2 million deaths. A better understanding of the host--mycobacterial--environmental interplay is central to developing better antituberculosis vaccines and treatments. This review will discuss how a clearer idea of this interplay is emerging with new genomic strategies in mouse models.

Animals↗
PubMed2005

Total workload, work stress and perceived symptoms in Swedish male and female white-collar employees.

BACKGROUND: The aim of this study was to analyse how paid work, unpaid household tasks, child care, work-child care interactions and perceived work stress are associated with reported symptoms in male and female white-collar employees. METHODS: A questionnaire was mailed to 1300 men and 1300 women belonging to the white-collar sector, with at least 35 hours of regular employment a week and a participant age of between 32 and 58 years. It contained items relating to total workload (hours spent on paid work, unpaid household tasks and childcare), subjective indices for work stress and symptoms. The response rate was 65% (743 women; 595 men). Gender difference in symptom prevalence was tested by analyses of variance. Odds ratios were used to estimate the bivariate associations between work-related variables and symptom prevalence. A multivariate analysis estimated the effect of paid and unpaid work interaction, work-childcare interplay and possible synergy. RESULTS: The frequency and severity of symptoms was higher in women than in men (P < 0.0001). Employed women's health was determined by the interaction between conditions at work and household duties (OR 2.09; 1.06-4.14), whereas men responded more selectively to long working hours, i.e. >50 h/week (OR 1.61; 1.02-2.54). However, childcare (<21 h/week) appeared to have a buffer effect on the risk of a high level of symptoms in men working long hours. CONCLUSION: Working life and private circumstances and the interplay between them need to be taken into account to curb stress-related ill health in both men and women.

Adult↗
PubMed2003

Dissemination of heart health promotion in the Ontario Public Health System: 1989-1999.

This paper reports the results of an analysis of the dissemination of community-based heart health promotion strategies. The research draws on diffusion and socio-ecological theories to study the first 10 years of heart health promotion in the public health system in Ontario, Canada. Using case description and interpretive analysis, the study describes developments in five stages of dissemination, and examines the interplay of factors operating in the internal organizational setting and the external environment in order to explain these developments. Findings demonstrate that dissemination of health promotion is a long-term, iterative process involving multiple stages. Dissemination is influenced by a complex interplay of factors operating within the public health system (especially traditional public health practice and champions) and factors in the environment in which the public health system operates (especially research, practice information and health policies). Implications are that policy makers should take a long-term view of dissemination, identify intermediate and long-term goals consistent with dissemination stages, and capitalize on internal and external forces supporting dissemination goals. Similar case-study research in other public health systems and time periods, and in more advanced stages of dissemination, will add further insight into the dissemination process.

Health Promotion↗
PubMed2002

Crassulacean acid metabolism: plastic, fantastic.

The occurrence, activity and plasticity of the CAM pathway is described from an introductory viewpoint, framed by the use of the four "Phases" of CAM as comparative indicators of the interplay between environmental constraints and internal molecular and biochemical regulation. Having described a number of "rules" which seem to govern the CAM cycle and apply uniformly to most species, a number of key regulatory points can then be identified. These include temporal separation of carboxylases, based on the circadian expression of key genes and their control by metabolites. The role of a circadian oscillator and interplay between tonoplast and nuclear control are central to maintaining the CAM cycle. Control of reserve carbohydrates is often neglected, but the importance of daily partitioning (for growth and the subsequent night-time CAM activity) and use at night is shown to drive the CAM cycle. Finally, it is shown that the genotypic and phenotypic plasticity in patterns of CAM expression is mediated partly by environmental conditions and molecular signalling, but also by diffusive constraints in succulent tissues. A transformation system is now required to allow these key areas of control to be elucidated.

Carbohydrate Metabolism↗
PubMed2004

Enzymes of arginine metabolism.

In mammals, L-arginine is classified as a semiessential or conditionally essential amino acid, depending on the developmental stage and health status of the individual. It can be derived from proline or glutamate, with the ultimate synthetic step catalyzed by argininosuccinate lyase. L-arginine is catabolized by arginases, nitric oxide synthases, arginine:glycine amidinotransferase, and possibly also by arginine decarboxylase, resulting ultimately in the production of urea, proline, glutamate, polyamines, nitric oxide, creatine, or agmatine. There is considerable diversity in tissue-specific and stimulus-dependent regulation of expression within this group of enzymes, and the expression of several of them can be regulated at transcriptional and translational levels by changes in the concentration of L-arginine itself. Consequently, the interplay among these enzymes in the regulation of specific aspects of arginine metabolism can be quite complex. For example, nitric oxide production can be affected by the interplay between nitric oxide synthases, arginases, and argininosuccinate synthetase. This metabolic complexity can pose challenges for analyses of arginine metabolism not only because L-arginine is a substrate for several different enzymes but also because ornithine and citrulline, key products of arginine metabolism, can each be produced by multiple enzymes. This overview highlights key features of the arginine metabolic enzymes and their interactions.

Animals↗
PubMed2005

Essential requirement for sphingosine kinase activity in eNOS-dependent NO release and vasorelaxation.

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid that acts both as an extracellular ligand for endothelial differentiation gene receptor family and as an intracellular second messenger. Cellular levels of S1P are low and tightly regulated by sphingosine kinase (SPK). Recent studies have suggested that eNOS pathway may function as a downstream target for the biological effects of receptor-mediated S1P. Here we have studied the possible interplay between intracellular SIP generation and the eNOS activation pathway. S1P causes an endothelium-dependent vasorelaxation in rat aorta that is PTX sensitive, inhibited by L-NAME that involves eNOS phosphorylation, and mainly dependent on hsp90. When rat aorta rings were incubated with the SPK inhibitor DL-threo-dihydrosphingosine (DTD), there was a concentration-dependent reduction of Ach-induced vasorelaxation, implying a consistent contribution of sphingolipid pathway through intracellular sphingosine release and phosphorylation. Co-immunoprecipitation experiments consistently showed increased association of hsp90 with eNOS after exposure of cells to S1P as well to BK or calcium ionophore A-23187. Interestingly, as opposite to A-23187, BK and S1P effect were significantly inhibited by pretreatment with the SPK inhibitor DTD. In conclusion, our data demonstrate that an interplay exists among eNOS, hsp90, and intracellularly generated S1P where eNOS coupling to hsp90 is a major determinant for NO release as confirmed by our functional and molecular studies.

Animals↗
PubMedDate not supplied

An explanatory model of health promotion and quality of life in chronic disabling conditions.

BACKGROUND: Although previous studies have examined selected factors influencing health-promoting behaviors or quality of life, the complex interplay of these variables in persons with chronic disabling conditions has not been investigated. OBJECTIVE: To test an explanatory model of variables influencing health promotion and quality of life (Stuifbergen & Rogers, 1997) in persons living with the chronic disabling condition of multiple sclerosis (MS). METHODS: A sample of 786 persons with MS (630 women and 156 men) completed a battery of instruments measuring severity of illness-related impairment, barriers to health-promoting behaviors, resources, self-efficacy, acceptance, health-promoting behaviors, and perceived quality of life. The proposed model was assessed and modified using the weighted least squares procedure (WLS), which is implemented by LISREL8 (Joreskog & Sorbom, 1993). RESULTS: The initial model was modified to obtain a recursive model with adequate fit, chi2 (8, N = 786) = 77, p < 0.05; GFI = 0.96; IFI = 0.98; CFI = 0.98. The antecedent variables accounted for 58% of the variance in the frequency of health-promoting behaviors and 66% of the variance in perceived quality of life. The effects of severity of illness on quality of life were mediated partially by health-promoting behaviors, resources, barriers, self-efficacy and acceptance. CONCLUSIONS: The final model supports the hypothesis that quality of life is the outcome of a complex interplay among contextual factors (severity of illness), antecedent variables (Stuifbergen & Rogers, 1997), and health-promoting behaviors. The strength of direct and indirect paths suggests that interventions to enhance social support, decrease barriers, and increase specific self-efficacy for health behaviors would result in improved health-promoting behaviors and quality of life. Further research using a longitudinal design is needed to clarify the effects of the interaction between health-promoting behaviors and trajectory of illness on quality of life for persons with chronic disabling conditions.

Adolescent↗
PubMed2001

Vision multiplexing: an engineering approach to vision rehabilitation device development.

Multiplexing is the transmission of two or more messages simultaneously over the same communication channel in a way that enables them to be separated and used at the receiving end. The normal visual system provides us with a very wide field of view at an apparent high resolution. The wide field of view is continuously monitored at a low resolution, providing information for navigation and detection of objects of interest. These objects of interest are sampled over time using the high-resolution fovea. Most disabling visual conditions impact only one of the components, the peripheral low-resolution wide field or the central high-resolution fovea. The loss of one of these components prevents the interplay of central and peripheral vision needed for normal function and causes disability. Traditionally low-vision aids replace or supplement the missing function, but usually at a cost of a significant loss in the surviving function. For example, magnifying devices increase resolution but reduce the field of view, whereas minifying devices increase the field of view but reduce resolution. A proposal to resolve many of the problems of current visual aids by exploring a general engineering approach--vision multiplexing--that takes advantage of the dynamic nature of human vision is presented. Vision multiplexing seeks to provide both the wide field of view and the high-resolution information in ways that could be accessed and interpreted by the visual system. This paper describes the use of optical methods and computer technologies in the development of a number of new visual aids, all of which apply vision multiplexing to restore the interplay of central and peripheral vision using eye movements in a natural way.

Biomedical Engineering↗
PubMedDate not supplied

Gonadal steroids in the treatment of mood disorders.

UNLABELLED: Increased interest in the complex interplay between gonadal steroids and neurotransmitter systems involved in mood has led investigators to question the role of gonadal steroids in the treatment of affective disorders, especially in women. OBJECTIVES: The purpose of this article is to provide a rationale for using gonadal hormones in the treatment of depression in women. METHODS: The literature is reviewed regarding 1) sex-specific phenomenologic and epidemiologic differences in the manifestation of psychiatric illness, 2) sex-specific differences in the therapeutic and adverse effects of psychotropic medications, 3) the complex interplay between gonadal steroids and neurotransmitter systems implicated in psychiatric disorders, and 4) the growing literature regarding the use of estrogen and progesterone in the treatment of mood disorders in women and androgens in the treatment of depression and sexual dysfunction in both men and women. RESULTS: Findings from pharmacologic trials of estrogen and androgens are encouraging, albeit mixed, in the treatment of mood disorders and decreased libido in women, respectively. Controlled studies have failed to confirm early open-label reports of the effectiveness of progesterone in the treatment of premenstrual syndrome. CONCLUSIONS: Pending replication, estrogen may become an important pharmacologic agent in the treatment of postnatal and perimenopausal depression, whereas androgens have been shown to improve libido in postmenopausal women and hypogonadal men. Progesterone cannot be recommended as a treatment for premenstrual syndrome or postnatal depression.

Disease Susceptibility↗
PubMedDate not supplied

Relationship between all-cause mortality and cumulative working life course psychosocial and physical exposures in the United States labor market from 1968 to 1992.

OBJECTIVE: To examine the relationship between cumulative exposures to psychosocial and physical work conditions and mortality in a nationally representative sample. METHODS: A working cohort was created using the U.S. Panel Study of Income Dynamics. Information on psychosocial and physical work conditions were imputed using the Job Characteristics Scoring System exposure matrix for the period 1968 through 1991 to construct working life courses. Deaths were ascertained from 1970 through 1992. RESULTS: Working in low-control jobs for a working life was associated with a 43% increase in the chance of death (OR, 1.43, 1.13-1.81) assuming a 10-year time lag. No significant effect was found for high-strain work (ie, high psychosocial job demands and low job control), but a relationship was found between passive work (ie, low psychosocial job demands and low job control) and mortality (OR, 1.35, 1.06-1.72). No significant risk of death was found for psychosocial or physical job demands, job security, or work-related social support. Retirement (OR, 2.85, 1.59-5.11) and unemployment (OR, 2.26, 1.65-3.10) transitions and baseline disability (OR, 1.38, 1.06-1.79) predicted mortality. CONCLUSIONS: The results support the importance of job control to health. The passive work effect suggests that job content may be important in shaping a worker's health over the life course. Future research should focus on modeling stressors over the life course to capture the dynamic interplay of life transitions, stressor intensity and duration and the role of health in the interplay.

Adult↗
PubMed1991

Trunk muscle and lumbar ligament contributions to dynamic lifts with varying degrees of trunk flexion.

This study was done to assess the interplay between muscular and ligamentous sources of extensor moment during dynamic lifting with various loads and flexion angles of the trunk segment for 15 subjects lifting a total of 150 loads. Ligament forces predicted from an anatomically detailed biomechanical model did not generally contribute more than 60 Nm for most of the lifts because the lumbar spine was only flexed to a moderate and constant degree for each load condition. In contrast, additional moment demands associated with increases in hand load were supported by muscle. Although the compression forces on the L4-5 intervertebral disc were fairly insensitive to the interplay between the recruitment of muscle and ligament, the shear force was significantly higher with a greater degree of lumbar flexion. The risk of injury may be influenced more by the degree of lumbar flexion than the choice of stoop or squat technique.

Adult↗
PubMed1998

Determinants of self-reported neck-shoulder and low back symptoms in a general population.

STUDY DESIGN: A combined cross-sectional and longitudinal design. OBJECTIVES: To investigate relation between, on one hand, self-reported neck-shoulder symptoms and, on the other hand, low back symptoms and self-reported work-related physical load, psychosocial factors, and individual characteristics and to study the influence of physical capacity in adolescence on neck-shoulder and low back symptoms in adulthood. SUMMARY OF BACKGROUND DATA: Heavy physical work and exposure to vibration constitute risk factors for low back problems, and repetitive and static work are risk factors for neck-shoulder symptoms in many jobs. The interplay between individual factors and work-related psychosocial and physical exposure, however, is not well documented. This study addresses effects of adolescent capacity on this interplay in a general population. METHODS: A random sample of 425 Swedish students was investigated when the students were 16 years and 34 years of age. Sixty-five percent participated in both examinations; only those who worked > or = 16 hours/week at the follow-up period, 148 men and 90 women, were included in these analyses. Data about musculoskeletal symptoms, work, and sociodemographic and individual characteristics were collected at the age of 34 years; physical performance data were collected at the ages of 16 years and 34 years. RESULTS: Among the men, self-employment and worry were associated with neck-shoulder symptoms; among the women, monotonous work and high decision latitude were associated with neck-shoulder symptoms. Low back problems were related to monotonous work among men and women and to exposure to vibration among men. Performance in certain fitness tests at the ages of 16 years and 34 years was negatively associated with musculoskeletal symptoms. CONCLUSIONS: The inverse relationships between performance at the age of 16 years and adult musculoskeletal symptoms may imply benefits of early fitness training.

Adolescent↗
PubMedDate not supplied

Heat loss and continuous renal replacement therapy.

Because of the devastating consequences of thermal imbalance, it is imperative that nurses understand these concepts and apply them to the daily care of their patients. Heat loss, heat conservation, and heat generation interplay to maintain the narrow range that is considered optimal for human cellular function. These concepts factor into patients who are critically ill but are especially important for patients undergoing continuous renal replacement therapy. Many of these types of dialysis expose the individual patient's blood to room temperature dialysate via an extracorporeal circuit 24-hours a day, sometimes for several weeks at a time. Critical care and advanced practice nurses must understand the interplay of the processes of heat loss, conservation, and heat generation to ensure patients undergoing this therapy achieve maximum benefit with the fewest complications possible.

Acute Kidney Injury↗
PubMed2000

The importance of the sympathetic nervous system and systolic hypertension in patients with hypertension: benefits in treating patients with increased cardiovascular risk.

The sympathetic nervous system is intimately involved in both the origin and the perpetuation of the hypertensive state, although there is some debate as to its precise contribution to the long-term hypertensive condition. Catecholamines are leading candidates to be both the pressor mechanism that initiates the rise in blood pressure and the trophic mechanism that maintains hypertension by vascular hypertrophy. Although the relationship between sympathetic nervous system and systolic blood pressure would seem intuitive, the multiple interactive pathways between these two pathways still needs to be more completely clarified, particularly as relates to interplay with the renin-angiotensin axis. Along this line of reasoning, a number of studies have examined the interplay between ACE inhibitors or angiotensin-receptor antagonists and alterations in sympathetic nervous system activity. Recent data support a role for one of the angiotensin-receptor antagonists, eprosartan, in having a potent inhibitory effect on pre-synaptic type-1 angiotensin receptors (AT(1) -receptors) involved in the enhancement of sympathetic nervous system activity. This may provide an explanation for the differential effect on systolic blood pressure exhibited by this compound.

Antihypertensive Agents↗
PubMed2006

In silico models of acute inflammation in animals.

Trauma and hemorrhagic shock elicit an acute inflammatory response, predisposing patients to sepsis, organ dysfunction, and death. Few approved therapies exist for these acute inflammatory states, mainly due to the complex interplay of interacting inflammatory and physiological elements working at multiple levels. Various animal models have been used to simulate these phenomena, but these models often do not replicate the clinical setting of multiple overlapping insults. Mathematical modeling of complex systems is an approach for understanding the interplay among biological interactions. We constructed a mathematical model using ordinary differential equations that encompass the dynamics of cells and cytokines of the acute inflammatory response, as well as global tissue dysfunction. The model was calibrated in C57Bl/6 mice subjected to (1) various doses of lipopolysaccharide (LPS) alone, (2) surgical trauma, and (3) surgery + hemorrhagic shock. We tested the model's predictive ability in scenarios on which it had not been trained, namely, (1) surgery +/- hemorrhagic shock + LPS given at times after the beginning of surgical instrumentation, and (2) surgery + hemorrhagic shock + bilateral femoral fracture. Software was created that facilitated fitting of the mathematical model to experimental data, as well as for simulation of experiments with various inflammatory challenges and associated variations (gene knockouts, inhibition of specific cytokines, etc.). Using this software, the C57Bl/6-specific model was recalibrated for inflammatory analyte data in CD14-/- mice and was used to elucidate altered features of inflammation in these animals. In other experiments, rats were subjected to surgical trauma +/- LPS or to bacterial infection via fibrin clots impregnated with various inocula of Escherichia coli. Mathematical modeling may provide insights into the complex dynamics of acute inflammation in a manner that can be tested in vivo using many fewer animals than has been possible previously.

Animals↗