Showing papers by "Laval University published in 2009"

Guidelines for the nomenclature of the human heat shock proteins

Abstract: The expanding number of members in the various human heat shock protein (HSP) families and the inconsistencies in their nomenclature have often led to confusion. Here, we propose new guidelines for the nomenclature of the human HSP families, HSPH (HSP110), HSPC (HSP90), HSPA (HSP70), DNAJ (HSP40), and HSPB (small HSP) as well as for the human chaperonin families HSPD/E (HSP60/HSP10) and CCT (TRiC). The nomenclature is based largely on the more consistent nomenclature assigned by the HUGO Gene Nomenclature Committee and used in the National Center of Biotechnology Information Entrez Gene database for the heat shock genes. In addition to this nomenclature, we provide a list of the human Entrez Gene IDs and the corresponding Entrez Gene IDs for the mouse orthologs.

Goodness-of-fit tests for copulas: A review and a power study

Abstract: Many proposals have been made recently for goodness-of-fit testing of copula models. After reviewing them briefly, the authors concentrate on “blanket tests”, i.e., those whose implementation requires neither an arbitrary categorization of the data nor any strategic choice of smoothing parameter, weight function, kernel, window, etc. The authors present a critical review of these procedures and suggest new ones. They describe and interpret the results of a large Monte Carlo experiment designed to assess the effect of the sample size and the strength of dependence on the level and power of the blanket tests for various combinations of copula models under the null hypothesis and the alternative. To circumvent problems in the determination of the limiting distribution of the test statistics under composite null hypotheses, they recommend the use of a double parametric bootstrap procedure, whose implementation is detailed. They conclude with a number of practical recommendations.

Heterosexual Risk of HIV-1 Infection Per Sexual Act: Systematic Review and Meta-Analysis of Observational Studies

Abstract: We did a systematic review and meta-analysis of observational studies of the risk of HIV-1 transmission per heterosexual contact. 43 publications comprising 25 different study populations were identified. Pooled female-to-male (0.04% per act [95% CI 0.01-0.14]) and male-to-female (0.08% per act [95% CI 0.06-0.11]) transmission estimates in high-income countries indicated a low risk of infection in the absence of antiretrovirals. Low-income country female-to-male (0.38% per act [95% CI 0.13-1.10]) and male-to-female (0.30% per act [95% CI 0.14-0.63]) estimates in the absence of commercial sex exposure (CSE) were higher. In meta-regression analysis, the infectivity across estimates in the absence of CSE was significantly associated with sex, setting, the interaction between setting and sex, and antenatal HIV prevalence. The pooled receptive anal intercourse estimate was much higher (1.7% per act [95% CI 0.3-8.9]). Estimates for the early and late phases of HIV infection were 9.2 (95% CI 4.5-18.8) and 7.3 (95% CI 4.5-11.9) times larger, respectively, than for the asymptomatic phase. After adjusting for CSE, presence or history of genital ulcers in either couple member increased per-act infectivity 5.3 (95% CI 1.4-19.5) times versus no sexually transmitted infection. Study estimates among non-circumcised men were at least twice those among circumcised men. Low-income country estimates were more heterogeneous than high-income country estimates, which indicates poorer study quality, greater heterogeneity of risk factors, or under-reporting of high-risk behaviour. Efforts are needed to better understand these differences and to quantify infectivity in low-income countries.

Regulatory T cells are key cerebroprotective immunomodulators in acute experimental stroke

Abstract: Systemic and local inflammatory processes have a key, mainly detrimental role in the pathophysiology of ischemic stroke. Currently, little is known about endogenous counterregulatory immune mechanisms. We examined the role of the key immunomodulators CD4(+)CD25(+) forkhead box P3 (Foxp3)(+) regulatory T lymphocytes (T(reg) cells), after experimental brain ischemia. Depletion of T(reg) cells profoundly increased delayed brain damage and deteriorated functional outcome. Absence of T(reg) cells augmented postischemic activation of resident and invading inflammatory cells including microglia and T cells, the main sources of deleterious cerebral tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), respectively. Early antagonization of TNF-alpha and delayed neutralization of IFN-gamma prevented infarct growth in T(reg) cell-depleted mice. Intracerebral interleukin-10 (IL-10) substitution abrogated the cytokine overexpression after T(reg) cell depletion and prevented secondary infarct growth, whereas transfer of IL-10-deficient T(reg) cells in an adoptive transfer model was ineffective. In conclusion, T(reg) cells are major cerebroprotective modulators of postischemic inflammatory brain damage targeting multiple inflammatory pathways. IL-10 signaling is essential for their immunomodulatory effect.

Live-animal tracking of individual haematopoietic stem/progenitor cells in their niche

Abstract: Stem cells reside in a specialized, regulatory environment termed the niche that dictates how they generate, maintain and repair tissues. We have previously documented that transplanted haematopoietic stem and progenitor cell populations localize to subdomains of bone-marrow microvessels where the chemokine CXCL12 is particularly abundant. Using a combination of high-resolution confocal microscopy and two-photon video imaging of individual haematopoietic cells in the calvarium bone marrow of living mice over time, we examine the relationship of haematopoietic stem and progenitor cells to blood vessels, osteoblasts and endosteal surface as they home and engraft in irradiated and c-Kit-receptor-deficient recipient mice. Osteoblasts were enmeshed in microvessels and relative positioning of stem/progenitor cells within this complex tissue was nonrandom and dynamic. Both cell autonomous and non-autonomous factors influenced primitive cell localization. Different haematopoietic cell subsets localized to distinct locations according to the stage of differentiation. When physiological challenges drove either engraftment or expansion, bone-marrow stem/progenitor cells assumed positions in close proximity to bone and osteoblasts. Our analysis permits observing in real time, at a single cell level, processes that previously have been studied only by their long-term outcome at the organismal level.

Regulation of innate immune responses in the brain.

Abstract: In this Review article, Serge Rivest discusses how microglial cells (the resident innate immune cells of the central nervous system) are activated during infection and injury, whether microglial cell activation is neurodestructive or neuroprotective, and how targeting these cells could be a therapeutic approach for the treatment of Alzheimer's disease. Microglial cells are the main innate immune cells of the complex cellular structure of the brain. These cells respond quickly to pathogens and injury, accumulate in regions of degeneration and produce a wide variety of pro-inflammatory molecules. These observations have resulted in active debate regarding the exact role of microglial cells in the brain and whether they have beneficial or detrimental functions. Careful targeting of these cells could have therapeutic benefits for several types of trauma and disease specific to the central nervous system. This Review discusses the molecular details underlying the innate immune response in the brain during infection, injury and disease.

A review of twenty years of SERVQUAL research

Abstract: Purpose – This paper reviews 20 years (1988‐2008) of research on the SERVQUAL scale for measuring service quality.Design/methodology/approach – A range of studies that have applied the SERVQUAL scale in this 20‐year period are examined in a non‐exhaustive review of the literature. These studies are selected from well‐known databases – such as “ABI/Inform”, “ScienceDirect”, and “EBSCOhost”.Findings – The paper identifies and summarizes numerous theoretical and empirical criticisms of the SERVQUAL scale. Despite these criticisms, the paper concludes that SERVQUAL remains a useful instrument for service‐quality research.Originality/value – The paper provides a useful source of information on SERVQUAL and its applications. In particular, the paper summarizes a selection of 30 applications of SERVQUAL.

Prosthetic Heart Valves Selection of the Optimal Prosthesis and Long-Term Management

Abstract: The introduction of valve replacement surgery in the early 1960s has dramatically improved the outcome of patients with valvular heart disease. Approximately 90 000 valve substitutes are now implanted in the United States and 280 000 worldwide each year; approximately half are mechanical valves and half are bioprosthetic valves. Despite the marked improvements in prosthetic valve design and surgical procedures over the past decades, valve replacement does not provide a definitive cure to the patient. Instead, native valve disease is traded for “prosthetic valve disease,” and the outcome of patients undergoing valve replacement is affected by prosthetic valve hemodynamics, durability, and thrombogenicity. Nonetheless, many of the prosthesis-related complications can be prevented or their impact minimized through optimal prosthesis selection in the individual patient and careful medical management and follow-up after implantation. The purpose of this article is to provide an overview of the current state of knowledge and future perspectives with regard to optimal prosthesis selection and clinical management after valve implantation. The ideal valve substitute should mimic the characteristics of a normal native valve. In particular, it should have excellent hemodynamics, long durability, high thromboresistance, and excellent implantability. Unfortunately, this ideal valve substitute does not exist, and each of the currently available prosthetic valves has inherent limitations. ### Mechanical Valves Three basic types of mechanical valve design exist: bileaflet, monoleaflet, and caged ball valves (Figure 1A, 1B, and 1C). Figure 1. Different types of prosthetic valves. A, Bileaflet mechanical valve (St Jude); B, monoleaflet mechanical valve (Medtronic Hall); C, caged ball valve (Starr-Edwards); D, stented porcine bioprosthesis (Medtronic Mosaic); E, stented pericardial bioprosthesis (Carpentier-Edwards Magna); F, stentless porcine bioprosthesis (Medtronic Freestyle); G, percutaneous bioprosthesis expanded over a balloon (Edwards Sapien); H, self-expandable percutaneous bioprosthesis (CoreValve). #### Caged Ball Valves Caged ball valves, which consist of a silastic ball with a circular sewing ring and a …

Smallest algae thrive as the Arctic Ocean freshens.

Abstract: As climate changes and the upper Arctic Ocean receives more heat and fresh water, it becomes more difficult for mixing processes to deliver nutrients from depth to the surface for phytoplankton growth. Competitive advantage will presumably accrue to small cells because they are more effective in acquiring nutrients and less susceptible to gravitational settling than large cells. Since 2004, we have discerned an increase in the smallest algae and bacteria along with a concomitant decrease in somewhat larger algae. If this trend toward a community of smaller cells is sustained, it may lead to reduced biological production at higher trophic levels.

Cognitive behavioral therapy, singly and combined with medication, for persistent insomnia: a randomized controlled trial.

Abstract: Context Cognitive behavioral therapy (CBT) and hypnotic medications are efficacious for short-term treatment of insomnia, but few patients achieve complete remission with any single treatment. It is unclear whether combined or maintenance therapies would enhance outcome. Objectives To evaluate the added value of medication over CBT alone for acute treatment of insomnia and the effects of maintenance therapies on long-term outcome. Design, Setting, and Patients Prospective, randomized controlled trial involving 2-stage therapy for 160 adults with persistent insomnia treated at a university hospital sleep center in Canada between January 2002 and April 2005. Interventions Participants received CBT alone or CBT plus 10 mg/d (taken at bedtime) of zolpidem for an initial 6-week therapy, followed by extended 6-month therapy. Patients initially treated with CBT attended monthly maintenance CBT for 6 months or received no additional treatment and those initially treated with combined therapy (CBT plus 10 mg/d of zolpidem) continued with CBT plus intermittent use of zolpidem or CBT only. Main Outcome Measures Sleep onset latency, time awake after sleep onset, total sleep time, and sleep efficiency derived from daily diaries (primary outcomes); treatment response and remission rates derived from the Insomnia Severity Index (secondary outcomes). Results Cognitive behavioral therapy used singly or in combination with zolpidem produced significant improvements in sleep latency, time awake after sleep onset, and sleep efficiency during initial therapy (all P Conclusion In patients with persistent insomnia, the addition of medication to CBT produced added benefits during acute therapy, but long-term outcome was optimized when medication is discontinued during maintenance CBT. Trial Registration clinicaltrials.gov Identifier: NCT00042146

Lakes and reservoirs as sentinels, integrators, and regulators of climate change

Abstract: Climate change is generating complex responses in both natural and human ecosystems that vary in their geographic distribution, magnitude, and timing across the global landscape. One of the major issues that scientists and policy makers now confront is how to assess such massive changes over multiple scales of space and time. Lakes and reservoirs comprise a geographically distributed network of the lowest points in the surrounding landscape that make them important sentinels of climate change. Their physical, chemical, and biological responses to climate provide a variety of information-rich signals. Their sediments archive and integrate these signals, enabling paleolimnologists to document changes over years to millennia. Lakes are also hot spots of carbon cycling in the landscape and as such are important regulators of climate change, processing terrestrial and atmospheric as well as aquatic carbon. We provide an overview of this concept of lakes and reservoirs as sentinels, integrators, and regulators of climate change, as well as of the need for scaling and modeling these responses in the context of global climate change. We conclude by providing a brief look to the future and the creation of globally networked sensors in lakes and reservoirs around the world.

Comparison of the effect of denosumab and alendronate on BMD and biochemical markers of bone turnover in postmenopausal women with low bone mass: a randomized, blinded, phase 3 trial.

Abstract: Denosumab is a fully human monoclonal antibody that inhibits bone resorption by neutralizing RANKL, a key mediator of osteoclast formation, function, and survival. This phase 3, multicenter, doubleblind study compared the efficacy and safety of denosumab with alendronate in postmenopausal women with low bone mass. One thousand one hundred eighty-nine postmenopausal women with a T-score

The Economic Burden of Insomnia: Direct and Indirect Costs for Individuals with Insomnia Syndrome, Insomnia Symptoms, and Good Sleepers

Abstract: INSOMNIA IS A PREVALENT PUBLIC HEALTH PROBLEM, WITH BETWEEN 6% AND 10% OF THE POPULATION MEETING DIAGNOSTIC CRITERIA FOR INSOMNIA syndrome1–3 and about a third of the population experiencing insomnia symptoms at any given moment.2 Despite its high prevalence, there is little information on the economic burden of insomnia. Information on the costs of illnesses, an indicator of their burden to society, is increasingly driving policy decisions about the funding and development of health care and research programs and priorities. Insurance companies are also concerned with the costs of illnesses and the impact that interventions may have in reducing symptoms and health care system utilization. Economic evaluations of the cost of illnesses or the cost effectiveness of treatments consider 2 broad categories of costs. These include direct costs associated with the consumption of resources (e.g., consultations, products, and testing), and indirect costs associated with the loss of resources (e.g., absenteeism, reduced productivity).4 While studies show a relationship between insomnia severity and the use of health-care service and product utilization,5–9 quantification of the associated costs is scarce. Similarly, some studies have reported a relationship between insomnia, increased absenteeism, and decreased productivity,10–13 yet the economic burden of this has been less frequently measured. The National Commission on Sleep Disorders Research estimated the direct costs of insomnia in the United States at $13.9 billion for the year 1995,14 whereas Leger et al.15 estimated the total cost of insomnia in France at about 10 million francs (or $2 billion US). The indirect costs associated with insomnia have received less attention in the literature, primarily because these costs are more difficult to estimate and quantify, there is no single database from which to draw, and measurement of these variables is more subject to interpretation and memory bias. Stoller16 attempted to quantify work-related deficits by combining data obtained in a study of workplace performance in Navy servicemen17 with her own insomnia prevalence estimate of 33% and a performance decrement estimate of 4%. The monetary value of absenteeism and lost productivity was estimated at $41.1 billion annually (1995 US$). A per person estimate was attempted by Chilcott and Shapiro,5 who suggest a decrease in work productivity due to insomnia of 10%. This amounts to $3,000 per insomnia sufferer per year. Stoller16 also looked at a number of other indirect costs, including insomnia-related accidents, alcoholism, and depression, estimating their costs at between $77.05 and $92.13 billion. Although these estimates have been criticized because they are based on liberal prevalence rates and relied on some questionable assumptions,9 they are still frequently used to describe the indirect economic consequences of insomnia. A French study18 concluded that insomnia is associated with increased absenteeism and reduced productivity, with associated costs about twice as high for insomnia patients as for good sleepers. The methods of costing did not allow, however, for an analysis of the proportional contribution of insomnia. There was also a methodological problem associated with double-counting costs that may have inflated cost estimates. Using existing data banks, Hillman et al.19 estimated the financial costs of all sleep disorders combined (e.g., insomnia, sleep apnea, periodic limb movements) for Australia at about $1,524 million, or 0.8% of the Australian gross domestic product. While an innovative approach was used to estimate fractions of other health impacts attributable to sleep disorders, this study did not permit the identification of costs associated with individual sleep disorders. A recent study by Ozminkowski et al.20 used medical claims data for health-care services, and absenteeism and short-term disability records to assess costs of insomnia occurring in adults in the US. After matching adult (aged 18–64) subsamples on variables determined by propensity score analysis, indirect costs combined were $1,253 higher in individuals with insomnia as compared to those without insomnia. The matching procedure and use of objective data lend strength to this study. However, costs related to reduced productivity, transportation, use of alcohol, and use of over-the-counter products were excluded from the analysis, suggesting that the results may underestimate the real cost of insomnia. Despite recent progress in documenting the economic burden of insomnia, some methodological weaknesses limit the current state of knowledge on this topic. The use of large administrative databases precludes analysis of potential confounding variables such as the reasons for consultations, use of OTC products, actual consumption of prescribed medications and, for some medications, the target ailment for which it was prescribed. When workplace records are used to obtain absenteeism data, reasons for absences are rarely provided and productivity data are not available. Similarly, the use of official accident records precludes identification of the contributing role of insomnia to these events. Studies typically use 2 groups—individuals with and without insomnia; the inclusion of an intermediate category would allow analysis of a linear relationship between costs and insomnia severity. The purpose of this study was to estimate, from the societal perspective, direct and indirect costs of insomnia. Costs were compared across three groups of participants classified as being good sleepers, having insomnia symptoms or having insomnia syndrome. The proportional contribution of insomnia to overall consultation costs and three indirect dependent cost variables, absenteeism, productivity and accidents, was also calculated.

Akt/GSK3 signaling in the action of psychotropic drugs.

Abstract: Psychotropic drugs acting on monoamine neurotransmission are major pharmacological treatments for neuropsychiatric conditions such as schizophrenia, depression, bipolar disorder, Tourette syndrome, ADHD, and Alzheimer disease. Independent lines of research involving biochemical and behavioral approaches in normal and/or genetically modified mice provide converging evidence for an involvement of the signaling molecules Akt and glycogen synthase kinase-3 (GSK3) in the regulation of behavior by dopamine and serotonin (5-HT). These signaling molecules have also received attention for their role in the actions of psychoactive drugs such as antidepressants, antipsychotics, lithium, and other mood stabilizers. Furthermore, investigations of the mechanism by which D2 dopamine receptors regulate Akt/GSK3 signaling strongly support the physiological relevance of a new modality of G protein-coupled receptor (GPCR) signaling involving the multifunctional scaffolding protein beta-arrestin 2. Elucidation of the contribution of multiple signaling pathways to the action of psychotropic drugs may provide a better biological understanding of psychiatric disorders and lead to more efficient therapeutics.

Brain activity during visual versus kinesthetic imagery: an fMRI study.

Abstract: Although there is ample evidence that motor imagery activates similar cerebral regions to those solicited during actual movements, it is still unknown whether visual (VI) and kinesthetic imagery (KI) recruit comparable or distinct neural networks. The present study was thus designed to identify, through functional magnetic resonance imaging at 3.0 Tesla in 13 skilled imagers, the cerebral structures implicated in VI and KI. Participants were scanned in a perceptual control condition and while physically executing or focusing during motor imagery on either the visual or kinesthetic components of an explicitly known sequence of finger movements. Subjects' imagery abilities were assessed using well-established psychological, chronometric, and new physiological measures from the autonomic nervous system. Compared with the perceptual condition, physical executing, VI, and KI resulted in overlapping (albeit non-identical) brain activations, including motor-related regions and the inferior and superior parietal lobules. By contrast, a divergent pattern of increased activity was observed when VI and KI were compared directly: VI activated predominantly the occipital regions and the superior parietal lobules, whereas KI yielded more activity in motor-associated structures and the inferior parietal lobule. These results suggest that VI and KI are mediated through separate neural systems, which contribute differently during processes of motor learning and neurological rehabilitation.

Visceral Obesity. The Link Among Inflammation, Hypertension, and Cardiovascular Disease

Abstract: The worldwide epidemic of obesity, fostered by the modern lifestyle characterized by the lack of physical activity and an energy-dense diet, has contributed to create an unprecedented condition in human history where a majority of overfed individuals will soon surpass the number of malnourished.1 Obesity-associated disorders, such as diabetes mellitus, an atherogenic dyslipidemia, and hypertension, have undoubtedly contributed to create an atherosclerosis-prone environment and thereby the development of cardiovascular disease (CVD), a leading cause of mortality in Westernized societies. A growing body of evidence indicates that obesity is a heterogeneous condition in which body fat distribution is closely associated with metabolic perturbations and, thus, with CVD risk.2 In this regard, accumulation of visceral (intra-abdominal) fat is strongly associated with insulin resistance and with a typical atherogenic dyslipidemic state.3 The adipose tissue, once considered a simple energy warehouse, is now regarded as a complex organ not only contributing to the management of energy flux within the body but also interacting with the inflammatory system and the vascular wall. Furthermore, recent studies have underlined that there are intricate interplays among adipocytes, the sympathetic nervous system (SNS), and the renin-angiotensin system (RAS), which participate in the obesity-associated dysmetabolic state. Thus, the adipose tissue is believed to play an important role in the development of both hypertension and other complications related to insulin resistance. However, it should be pointed out that different fat depots have distinct metabolic characteristics, leading to individual differences in the impact of obesity on cardiometabolic risk. Herein, we reviewed the complex links among visceral adiposity, inflammation, and hypertension, along with an attempt to address the clinical implications of these interactions. ### Small, Dense Low-Density Lipoprotein By its peculiar location, the expanded visceral fat depot has easy access to the liver via the portal circulation, where it could influence metabolism and promote insulin …

A systematic review of clinical outcomes, clinical process, healthcare utilization and costs associated with telerehabilitation

Abstract: Purpose. To identify clinical outcomes, clinical process, healthcare utilization and costs associated with telerehabilitation for individuals with physical disabilities.Method. Relevant databases were searched for articles on telerehabilitation published until February 2007. Reference lists were examined and key journals were hand searched. Studies that included telerehabilitation for individuals with physical impairments and used experimental or observational study designs were included in the analysis, regardless of the specific clientele or location of services. Data was extracted using a form to record methodological aspects and results relating to clinical, process, healthcare utilization and cost outcomes. Study quality of randomized clinical trials was assessed using the PEDro rating scale.Results. Some 28 articles were analysed. These dealt with rehabilitation of individuals in the community, neurological rehabilitation, cardiac rehabilitation, follow-up of individuals with spinal cord injuries, r...

Existence of a microRNA pathway in anucleate platelets

Abstract: Platelets have a crucial role in the maintenance of hemostasis as well as in thrombosis and vessel occlusion, which underlie stroke and acute coronary syndromes. Anucleate platelets contain mRNAs and are capable of protein synthesis, raising the issue of how these mRNAs are regulated. Here we show that human platelets harbor an abundant and diverse array of microRNAs (miRNAs), which are known as key regulators of mRNA translation in other cell types. Further analyses revealed that platelets contain the Dicer and Argonaute 2 (Ago2) complexes, which function in the processing of exogenous miRNA precursors and the control of specific reporter transcripts, respectively. Detection of the receptor P2Y(12) mRNA in Ago2 immunoprecipitates suggests that P2Y(12) expression may be subjected to miRNA control in human platelets. Our study lends an additional level of complexity to the control of gene expression in these anucleate elements of the cardiovascular system.

Intraarticular injection of anakinra in osteoarthritis of the knee: a multicenter, randomized, double-blind, placebo-controlled study.

Abstract: Objective To evaluate the clinical response, safety, and tolerability of a single intraarticular injection of anakinra in patients with symptomatic osteoarthritis (OA) of the knee. Methods Patients with OA of the knee were enrolled in a multicenter, double-blind, placebo-controlled study and randomized 2:1:2 to receive a single intraarticular injection of placebo, anakinra 50 mg, or anakinra 150 mg in their symptomatic knee. Patients were evaluated for 12 weeks postinjection. The primary end point was the change in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score from baseline to week 4. Safety assessments included the evaluation of adverse events (AEs), laboratory tests, and vital signs. Pharmacokinetic parameters were assessed in a subset of patients. Results Of 170 patients who enrolled, 160 (94%) completed the study. The mean improvements from baseline to week 4 in the WOMAC score were not statistically different between the placebo group and the patients who received 50 mg of anakinra (P = 0.67) or 150 mg of anakinra (P = 0.77). Anakinra was well tolerated. No withdrawals due to AEs or serious AEs, and no serious infections or deaths were reported. No clinically significant trends were noted in laboratory values or vital signs. Pharmacokinetic parameters demonstrated that the mean terminal half-life of anakinra in serum after intraarticular injection was ∼4 hours. Conclusion Anakinra was well tolerated as a single 50-mg or 150-mg intraarticular injection in patients with OA of the knee. However, anakinra was not associated with improvements in OA symptoms compared with placebo.

The Natural History of Insomnia : A Population-Based 3-Year Longitudinal Study

Abstract: Background Despite its high prevalence, little information is available about the natural history of insomnia. The extent to which episodes of insomnia will persist or remit over time is difficult to predict. We examined the natural history of insomnia and describe the most common trajectories over 3 years. Methods Three hundred eighty-eight adults (mean [SD] age, 44.8 [13.9] years; 61% women) were selected from a larger population-based sample on the basis of the presence of insomnia at baseline. They completed standardized sleep/insomnia questionnaires at 3 annual follow-up assessments. For each follow-up assessment, participants were classified into 1 of 3 groups (individuals with an insomnia syndrome, individuals with insomnia symptoms, and individuals with good sleep) on the basis of algorithms using standard diagnostic criteria for insomnia. Rates of persistent insomnia, remission, and relapse were computed for each group. Results Of the study sample, 74% reported insomnia for at least 1 year (2 consecutive assessments) and 46% reported insomnia persisting over the entire 3-year study. The course of insomnia was more likely to be persistent in those with more severe insomnia at baseline (ie, insomnia syndrome) and in women and older adults. Remission rate was 54%; however, 27% of those with remission of insomnia eventually experienced relapse. Individuals with subsyndromal insomnia at baseline were 3 times more likely to remit than worsen to syndrome status, although persistence was the most frequent course in that group as well. Conclusion These findings indicate that insomnia is often a persistent condition, in particular when it reaches the diagnostic threshold for an insomnia disorder.

Incidence and risk factors of insomnia in a population-based sample.

Abstract: INSOMNIA IS AMONG THE MOST PREVALENT HEALTH COMPLAINTS. APPROXIMATELY 9% OF THE GENERAL POPULATION REGULARLY SUFFER FROM INSOMNIA, and about 30% do so occasionally.1–3 Incidence rates reported in longitudinal studies vary extensively (from 3% to 20%), depending on the population studied, the time interval (e.g., 1 year versus 10 years), and the definition of insomnia used (i.e., insomnia syndrome versus symptoms). For instance, it is estimated that over a period of one year, approximately 6% of the general population develop an insomnia syndrome,4 and approximately 20% develop insomnia symptoms, with the latter figures being based on samples of older adults5 and individuals with chronic health problems.6 Furthermore, new onset of insomnia is generally more frequent among women and individuals with medical conditions, psychiatric disorders, and a perceived stressful life.4,7–9 Based on a tripartite conceptual framework widely used to explain the development of insomnia,10–12 3 types of factors are involved at different times during the course of insomnia. First, everyone is, to some degree, predisposed to develop insomnia. Second, a precipitating event is usually associated with the onset of insomnia. Third, insomnia is perpetuated over time by psychological and behavioral factors, even after precipitating factors have been controlled or eliminated. The most commonly hypothesized predisposing factors include demographic factors (e.g., aging, female gender, living alone),1,3,13 familial/hereditary conditions (a personal or family history of insomnia),14–16 psychological factors (e.g., anxiety, depression, personality traits),4,17–19 and physiological and lifestyle factors (e.g., arousability and smoking).20,21 Precipitating factors include stressful life events (e.g., divorce),9,22 as well as psychological and health-related factors (e.g., pain, mental health problems).10,23 Finally, maintaining factors include maladaptive sleep habits (e.g., excessive amounts of time spent in bed, napping, chronic medication use) and dysfunctional cognitions about sleep loss and its impact on life (e.g., worry over sleep loss).10 Most studies investigating insomnia risk factors have been either retrospective or cross-sectional, precluding unequivocal inference about the relationship between these factors and the development of insomnia. The extent to which depression and anxiety trigger insomnia or represent consequences of insomnia remains ambiguous. The few longitudinal studies of insomnia have provided informative data about incidence and risk factors, although most of those studies have focused predominantly on selected samples such as young adults,7,28 elderly adults,8,24,25 or patients attending medical practices.6,26,27 Only one longitudinal study evaluating the relation between sleep problem symptoms (i.e., insomnia and hypersomnia) and psychiatric disorders sampled the population at large.4 Few studies have used standard diagnostic criteria to define insomnia. Moreover, previous studies have used various time frames and most have not adequately operationalized their measure of incidence. For instance, most studies have not differentiated between incident cases of first episode of insomnia (no prior history of insomnia) and cases of recurrence (with past history of insomnia). Furthermore, the majority of studies included only individuals experiencing insomnia at the time of the second assessment in their incidence estimates5,6,8,29 rather than all cases emerging during the interval between baseline and follow-up assessment.7 Since insomnia may prove transient or episodic, incidence rates may have been underestimated in previous studies. The National Institutes of Health30 called for additional longitudinal studies using well-operationalized and stringent diagnostic criteria to estimate insomnia incidence and identify risk factors within the general population. The objectives of this study were to estimate the incidence of insomnia symptoms and syndrome and to identify associated risk factors in a cohort of good sleepers sampled from the general population and followed over a one-year period.

Fear of Cancer Recurrence Inventory: development and initial validation of a multidimensional measure of fear of cancer recurrence

Abstract: Background Despite the fact that the fear of cancer recurrence is to varying degrees almost universal in cancer survivors, there is a lack of validated multidimensional instruments to evaluate this issue specifically.

Service quality, emotional satisfaction, and behavioural intentions: A study in the hotel industry

Abstract: Purpose – The purpose of this paper is to develop and test a conceptual model of the relationships among the constructs of “service quality”, “emotional satisfaction”, and “behavioural intention” in the hospitality industry.Design/methodology/approach – The study utilises a review of the literature to propose a conceptual model that postulates that: service quality is positively related to consumers' emotions; service quality is positively related to behavioural intentions; and consumers' emotions are positively related to behavioural intentions. Moreover, the model postulates that emotional satisfaction partially mediates the effect of service quality on behavioural intentions. The model is tested in an empirical study with data from a survey among 200 Canadian travellers.Findings – All the hypothesised relationships are supported. The results confirm that service quality exerts both direct and indirect effects (through emotional satisfaction) on behavioural intentions.Research limitations/implications –...

Beyond description: the active and effective way to infer processes from spatial patterns

Abstract: The ecological processes that create spatial patterns have been examined by direct measurement and through measurement of patterns resulting from experimental manipulations. But in many situations, creating experiments and direct measurement of spatial processes can be difficult or impossible. Here, we identify and define a rapidly emerging alternative approach, which we formalize as "space as a surrogate" for unmeasured processes, that is used to maximize inference about ecological processes through the analysis of spatial patterns or spatial residuals alone. This approach requires three elements to be successful: a priori hypotheses, ecological theory and/or knowledge, and precise spatial analysis. We offer new insights into a long-standing debate about process-pattern links in ecology and highlight six recent studies that have successfully examined spatial patterns to understand a diverse array of processes: competition in forest-stand dynamics, dispersal of freshwater fish, movement of American marten, invasion mechanisms of exotic trees, dynamics of natural disturbances, and tropical-plant diversity. Key benefits of using space as a surrogate can be found where experimental manipulation or direct measurements are difficult or expensive to obtain or not possible. We note that, even where experiments can be performed, this procedure may aid in measuring the in situ importance of the processes uncovered through experiments.

Shape-controlled synthesis of highly crystalline titania nanocrystals.

Abstract: A versatile synthetic method based on solvothermal technique has been developed for the fabrication of TiO2 nanocrystals with different shapes such as rhombic, truncated rhombic, spherical, dog-bone, truncated and elongated rhombic, and bar. The central features of our approach are the use of water vapor as hydrolysis agent to accelerate the reaction and the use of both oleic acid and oleylamine as two distinct capping surfactants which have different binding strengths to control the growth of the TiO2 nanoparticles. We also show that the presence of an appropriate amount of water vapor along with the desired oleic acid/oleylamine molar ratio plays a crucial role in controlling size and shape of TiO2 nanocrystals.

Sirtuin 1 reduction parallels the accumulation of tau in Alzheimer disease.

Abstract: Aging and metabolism-related disorders are risk factors for Alzheimer disease (AD) Because sirtuins may increase the life span through regulation of cellular metabolism, we compared the concentration of sirtuin 1 (SIRT1) in the brains of AD patients (n = 19) and controls (n = 22) using Western immunoblots and in situ hybridization We report a significant reduction of SIRT1 (messenger RNA [mRNA], -29%; protein, -45%) in the parietal cortex of AD patients, but not in the cerebellum Further analyses in a second cohort of 36 subjects confirmed that cortical SIRT1 was decreased in AD but not in individuals with mild cognitive impairment SIRT1 mRNA and its translated protein correlated negatively with the duration of symptoms (mRNA, r2 = -0367; protein, r2 = -0326) and the accumulation of paired helical filament tau (mRNA, r2 = -0230; protein, r2 = -0119), but weakly with insoluble amyloid-beta 42 (mRNA, r2= -0090; protein, r2 = -0072) A significant relationship between SIRT1 levels and global cognition scores proximate to death was also found (r2= +009, p = 0049) In contrast, cortical SIRT1 levels remained unchanged in a triple-transgenic animal model of AD Collectively, our results indicate that loss of SIRT1 is closely associated with the accumulation of amyloid-beta and tau in the cerebral cortex of persons with AD

Wildfire responses to abrupt climate change in North America

Abstract: It is widely accepted, based on data from the last few decades and on model simulations, that anthropogenic climate change will cause increased fire activity. However, less attention has been paid to the relationship between abrupt climate changes and heightened fire activity in the paleorecord. We use 35 charcoal and pollen records to assess how fire regimes in North America changed during the last glacial–interglacial transition (15 to 10 ka), a time of large and rapid climate changes. We also test the hypothesis that a comet impact initiated continental-scale wildfires at 12.9 ka; the data do not support this idea, nor are continent-wide fires indicated at any time during deglaciation. There are, however, clear links between large climate changes and fire activity. Biomass burning gradually increased from the glacial period to the beginning of the Younger Dryas. Although there are changes in biomass burning during the Younger Dryas, there is no systematic trend. There is a further increase in biomass burning after the Younger Dryas. Intervals of rapid climate change at 13.9, 13.2, and 11.7 ka are marked by large increases in fire activity. The timing of changes in fire is not coincident with changes in human population density or the timing of the extinction of the megafauna. Although these factors could have contributed to fire-regime changes at individual sites or at specific times, the charcoal data indicate an important role for climate, and particularly rapid climate change, in determining broad-scale levels of fire activity.