bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of the mediation effect with a binary mediator
Authors: Li Yan , Schneider Julie A. , Bennett David A. 
Published: October 2006

AbstractA mediator acts as a third variable in the causal pathway between a risk factor and an outcome. In this paper, we consider the estimation of the mediation effect when the mediator is a binary variable. We give a precise definition of the mediation effect and examine asymptotic properties of five different estimators of the mediation effect. Our theoretical developments, which are supported by a Monte Carlo study, show that the estimators that account for the binary nature of the mediator are consistent for the mediation effect defined in this paper while other estimators are inconsistent. We use these estimators to study the mediation effect of chronic cerebral infarction in the causal relationship between the apolipoprotein E ε4 allele and cognitive function among 233 deceased participants from the Religious Orders Study, a longitudinal, clinical‐pathologic study of aging and Alzheimer's disease. Copyright © 2006 John Wiley & Sons, Ltd.
Chronic heart failure slows late sodium current in human and canine ventricular myocytes: Implications for repolarization variability
Authors: Maltsev Victor A. , Silverman Norman , Sabbah Hani N. , Undrovinas Albertas I. 
Published: October 2006

AbstractBackground:Late Na+ current (INaL) in human and dog hearts has been implicated in abnormal repolarization associated with heart failure (HF). HF slows inactivation gating of late Na+ channels, which could contribute to these abnormalities.Aims:To test how altered gating affects INaL time course, Na+ influx, and action potential (AP) repolarization.Methods:INaL and AP were measured by patch clamp in left ventricular cardiomyocytes from normal and failing hearts of humans and dogs. Canine HF was induced by coronary microembolization.Results:INaL decay was slower and INaL density was greater in failing hearts than in normal hearts at 24 °C (human hearts: τ659±16 vs. 529±21ms; n=16 and 4 hearts, respectively; mean±SEM; p<0.002; dog hearts: 561±13 vs. 420±17ms; and 0.307±0.014 vs. 0.235±0.019pA/pF; n=25 and 14 hearts, respectively; p<0.005) and at 37°C this difference tended to increase. These INaL changes resulted in much greater (53.6%) total Na+ influx in failing cardiomyocytes. INaL was sensitive to cadmium but not to cyanide and exhibited low sensitivity to saxitoxin (IC50=62nM) or tetrodotoxin (IC50=1.2 μM), tested in dogs. A 50% INaL inhibition by toxins or passing current opposite to INaL, decreased beat‐to‐beat AP variability and eliminated early afterdepolarizations in failing cardiomyocytes.Conclusions:Chronic HF leads to larger and slower INaL generated mainly by the cardiac‐type Na+ channel isoform, contributing to larger Na+ influx and AP duration variability. Interventions designed to reduce/normalize INaL represent a potential cardioprotective mechanism in HF via reduction of related Na+ and Ca2+ overload and improvement of repolarization.
Hyperuricaemia and long‐term outcome after hospital discharge in acute heart failure patients
Authors: Pascual‐Figal Domingo A. , Hurtado‐Martínez Jose A. , Redondo Belen , Antolinos Maria J. , Ruiperez Juan A. , Valdes Mariano 
Published: October 2006

AbstractBackgroundUric acid (UA) may be involved in chronic heart failure (HF) pathogenesis, entailing a worse outcome. The purpose of this study was to examine the role of hyperuricaemia as a prognostic marker after hospital discharge in acute HF patients.MethodsWe studied 212 patients consecutively discharged after an episode of acute HF with LVEF<40%. Blood samples for UA measurement were extracted in the morning prior to discharge. The evaluated endpoints were death and new HF hospitalization.ResultsMean UA levels were 7.4±2.4 mg/dl (range 1.6 to 16 mg/dl), with 127 (60%) of patients being within the range of hyperuricaemia. Hyperuricaemia was associated with a higher risk of death (n=48) (HR 2.0, 95% CI 1.1–3.9,p=0.028), new HF readmission (n=67) (HR 1.8, 95% CI 1.1–3.1,p=0.023) and the combined event (n=100) (HR 1.9, 95% CI 1.2–2.9,p=0.004). At 24 months, cumulative event‐free survival was lower in the two higher UA quartiles (36.9% and 40.7% vs. 63.5% and 59.5%, log rank=0.006). After adjustment for potential confounders, hyperuricaemia remains an independent risk factor for adverse outcomes (HR 1.6, 95% CI 1.1–2.6,p=0.02).ConclusionsIn hospitalized patients with acute HF and LV systolic dysfunction, hyperuricaemia is a long‐term prognostic marker for death and/or new HF readmission.
Nonattendance of adult otolaryngology patients for scheduled appointments
Authors: Cohen A D , Kaplan D M , Kraus M , Rubinshtein E , Vardy D A 
Published: October 2006

Background: Nonattendance for appointments is an impediment to otolaryngology patient care worldwide. In a previous study of children attending an otolaryngology clinic, we observed that attendance was determined by the waiting time for an appointment and the timing of the appointment within the day. However, the factors that affect nonattendance in adults have not been well studied.Objective: We aimed to investigate factors associated with nonattendance in adults visiting an otolaryngology clinic.Methods: Nonattendance was observed for a period of one year in adult patients visiting an ambulatory otolaryngology clinic. The following parameters were also noted: age, gender, treating physician, waiting time and timing of the appointment. The chi-square test was used to analyse differences between categorical variables. The t-test was used to analyse differences between continuous variables. Logistic regression was used for multivariate analyses.Results: The study assessed 8071 visits to the otolaryngology clinic. The overall proportion of nonattendance was 27.7 per cent. A multivariate logistic regression model demonstrated that nonattendance was significantly associated with the following factors: female gender, younger age, long waiting time for an appointment, timing of the appointment within the day and the treating physician.Conclusion: In adult otolaryngology patients, nonattendance was associated with patient-related factors and healthcare systems related factors alike. It is suggested that managed overbooking could be carefully introduced into otolaryngology patient scheduling.
A qualitative study of the trauma and posttraumatic growth of
multiple myeloma patients treated with peripheral blood stem cell
transplant
Authors: DAHAN JACQUELINE FINE , AUERBACH CARL F. 
Published: October 2006

Objective: The study was conducted to understand the
emotional impact of multiple myeloma, as well as the impact of its
principle treatment, peripheral blood stem cell transplant (PBSCT). The
absence of psycho-oncology research literature on this population prompted
the need for a hypothesis-generating investigation. Thus, a qualitative
design was used to construct a theoretical model of the trauma relating to
diagnosis and treatment of myeloma. The study also incorporates the
important period of reflection and growth following treatment.Methods: The sample consisted of 3 women and 3 men treated
for myeloma at a New York City-based cancer treatment center. Data from
individual interviews were audiotaped and transcribed. After extensive
review, the data were categorized into groups of repeating ideas, themes
and broad theoretical constructs.Results: A five-construct model emerged from the data
analysis that integrated a model of trauma and growth presented in earlier
work (Auerbach et al., 2006). These constructs
roughly correspond with stages of illness, but do not necessarily imply a
linear process, as suggested by stage models. The first construct is
diagnosis. Patients receive the news that they have multiple myeloma.
Initial reactions are discussed and a treatment plan takes form. In the
second construct, treatment, patients highlight the physical and emotional
hurdles confronted throughout treatment. The third construct, network of
safety, presents social factors that play a role in comforting patients
throughout illness. Patients recognize the importance of a strong support
system during their experiences. In the fourth construct, recuperation,
physical energy is regained after an arduous recovery period. This
contributes to higher spirits and a motivation to reengage with life. The
fifth construct is reflection and new existence. Patients strive to
balance a new reality that relapse and death are inevitable, along with
their need to live a meaningful life. Many do not yet appreciate how their
disease has impacted them, but describe how their interpersonal lives and
perceptions have changed, both positively and negatively.Significance of results: Limitations of the study, future
directions for research and clinical implications are discussed.
Nutrient regulation of pancreatic β-cell function in diabetes: problems and potential solutions
Authors: Flatt P.R. , Green B.D. 
Published: October 2006

Increasing prevalence of obesity combined with longevity will produce an epidemic of Type 2 (non-insulin-dependent) diabetes in the next 20 years. This disease is associated with defects in insulin secretion, specifically abnormalities of insulin secretory kinetics and pancreatic β-cell glucose responsiveness. Mechanisms underlying β-cell dysfunction include glucose toxicity, lipotoxicity and β-cell hyperactivity. Defects at various sites in β-cell signal transduction pathways contribute, but no single lesion can account for the common form of Type 2 diabetes. Recent studies highlight diverse β-cell actions of GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). These intestinal hormones target the β-cell to stimulate glucose-dependent insulin secretion through activation of protein kinase A and associated pathways. Both increase gene expression and proinsulin biosynthesis, protect against apoptosis and stimulate replication/neogenesis of β-cells. Incretin hormones therefore represent an exciting future multi-action solution to correct β-cell defect in Type 2 diabetes.
Mechanisms regulating energy metabolism by adiponectin in obesity and diabetes
Authors: Fang X. , Sweeney G. 
Published: October 2006

Nutritional control of molecular events has become of great interest given the increased incidence of diet-induced obesity, and consequently Type 2 (non-insulin-dependent) diabetes, in recent years. The altered adipose tissue content in obese individuals results in an altered profile of circulating adipokines, and here we focus on adiponectin, whose circulating levels decrease in obese individuals. Adiponectin is a 30 kDa protein but circulates primarily as hexameric, oligomeric and, to a lesser extent, trimeric forms. Full-length adiponectin can also be cleaved to produce a fragment containing the globular domain that exerts potent metabolic effects. Adiponectin has insulin-mimetic and -sensitizing actions including stimulation of glucose uptake in skeletal muscle and suppression of glucose production in liver. Hence, adiponectin has attracted great interest as an antidiabetic agent. Adiponectin acts via two receptor isoforms, AdipoR1 (adiponectin receptor 1) and AdipoR2, which have distinct tissue distributions and affinities for recognition of the various adiponectin forms. Expression of AdipoR isoforms can be regulated by hyperinsulinaemia and hyperglycaemia with the consequence of increased sensitivity or resistance to specific forms of adiponectin. In summary, regulation of adiponectin or AdipoR expression may be of great importance in the development of metabolic perturbations characteristic of Type 2 diabetes in obese individuals.
Regulation of insulin secretion by uncoupling protein
Authors: Chan C.B. , Kashemsant N. 
Published: October 2006

UCPs (uncoupling proteins) can regulate cellular ATP production by uncoupling oxidative phosphorylation. UCP2 is expressed in islet β-cells and its induction reduces glucose-stimulated insulin secretion. Under physiological conditions, superoxide, formed as a by-product of respiration, activates UCP2. This leads to reduced ATP production, which impairs closure of the ATP-dependent K+ channels to prevent insulin secretion. It is suggested that the physiological role of UCP2 is to prevent excessive superoxide generation through a feedback loop. UCP2 induction may also alter fatty acid metabolism by altering NAD/NADH or by facilitating cycling of fatty acid anions. Recently, UCP2 has been proposed to keep insulin secretion low during starvation, a function under the control of the transcription co-repressor, surtuin-1, which has been shown to bind to the UCP2 promoter. Pathological UCP2 expression or activation may suppress glucose-stimulated insulin secretion to the extent that diabetes onset is hastened. In ob/ob mice, induction of UCP2 at age 5 weeks precedes development of insulin secretion defects and hyperglycaemia. Activating protein kinase A-dependent pathways can normalize insulin secretion in UCP2-overexpressing islets. Conversely, lowering UCP2 expression may promote increased insulin secretion. UCP2 knockout mice were protected from the diabetogenic effects of a high-fat diet and their islets exhibited increased sensitivity to glucose and elevated ATP/ADP. These results support a role for UCP2 as a gene contributing to the pathogenesis of Type 2 diabetes.
On Growth Poles
Authors: Lasuen J.R. 
Published: October 2006

Perroux argued that economic space as an abstract field of forces leads to the notion of a vector of economic forces, and hence to the concept of growth poles. His further view that economic development necessarily requires spatial polarisation is an inaccurate and damaging limitation of this concept. Whilst the early stages of economic development must generate growth points due to a lack of entrepreneurship outside these centres, development in advanced countries is becoming less polarised. This is caused by the increasingly diversified structure of business which results in an extensive spatial spread of innovations and economic development. It follows that developing countries can accelerate their growth by creating diversified corporate structures which diminish the exigencies of a polarised strategy.
Public Housing and Slums: Cure or Cause?
Authors: Vitaliano Donald F. 
Published: October 2006

This paper tests the hypothesis that an increase in the supply of public housing causes a substantially offsetting decline in the quantity supplied of competing private units. The statistical results offer little by way of confirmation of this view. A comparative statics model of the rental housing market is presented from which estimating equations suitable for regression analysis are derived. Data from the US Census are used to estimate the effect of public housing on the private rental sector in 33 cities in New York State. The empirical evidence suggests a 5 to 9 per cent induced decline in private market rents per one per cent increase in the proportion of public units in the total housing stock. No meaningful evidence of private market vacancies, demolitions or dilapidation offsetting to the public units was found.
Staphylococcus aureus Bacteremia in Older Adults: Predictors of 7-Day Mortality and Infection With a Methicillin-Resistant Strain
Authors: Bader Mazen S. 
Published: October 2006

Objectives.To determine the predictors of 7-day mortality in older adult patients with Staphylococcus aureus bacteremia after controlling for comorbidity using the Charlson weighted index of comorbidity (WIC) and to identify the risk factors associated with bacteremia due to methicillin-resistant S. aureus (MRSA).Design.Retrospective cohort study from January 2003 until December 2004.Setting.Two tertiary care, university-affiliated hospitals.Methods.One hundred thirty-five hospitalized patients with S. aureus bacteremia were included in the study. All patients who were 60 years or older and had 1 or more blood cultures positive for S. aureus were included in the study. The primary outcome was death 7 days after the onset of S. aureus bacteremia.Results.Twenty-one patients (15.6%) died within 7 days after the onset of S. aureus bacteremia. Seventy-four patients (56.1%) had MRSA bacteremia. Multivariate analysis identified 3 independent determinants of 7-day mortality: Charlson WIC score greater than 5 (odds ratio [OR], 3.6 [95% confidence interval {CI}, 1.1-11.2]; P = .03), previous hospitalization in the past 3 months (OR, 5.0 [95% CI, 1.1-25.1]; P = .04), and altered mental status at the onset of S. aureus bacteremia (OR, 13.6 [95% CI, 2.9-64.6]; P = .001). Multivariate analysis identified .previous hospitalization in the past 3 months (OR, 2.6 [95% CI, 1.1-5.9]; P = .02), residence in a long-term care facility (OR, 4.5 [95% CI, 1.7-12.3]; P = .003), and altered mental status at the onset of S. aureus bacteremia (OR, 2.5 [95% CI, 1.5-5.6]; P = .02) to be independently associated with the presence of MRSA.Conclusions.The Charlson WIC is significantly associated with increased mortality of S. aureus bacteremia in older adults. Previous hospitalization in the past 3 months, residence in a long-term care facility, and altered mental status should be used as a guidance for empirical vancomycin therapy and application of infection control measures in older adults with suspected S. aureus bacteremia.
Reproduction of the angular angel shark (Squatina guggenheim): geographic differences, reproductive cycle, and sexual dimorphism
Authors: Colonello Jorge H. , Lucifora Luis O. , Massa Ana M. 
Published: October 2006

Abstract
Colonello, J. H., Lucifora, L. O., and Massa, A. M. 2007. Reproduction of the angular angel shark (Squatina guggenheim): geographic differences, reproductive cycle, and sexual dimorphism. – ICES Journal of Marine Science, 64: 131–140. The reproductive ecology of Squatina guggenheim from two coastal areas in South America is analysed. In both sexes, individuals from ER (El Rincón coastal system, the more southern area) attained a larger maximum total length (LT) and a heavier weight at a given length than those from LP (La Plata River estuary). Females from ER mature at a significantly larger LT than females from LP. These patterns could be explained by an advantage of larger body size at higher latitudes in providing more reserves for winter, because individuals from ER have a larger liver than those from LP. Spines in the outer part of the pectoral fins were observed only in adult males. Fecundity increased with female total length. Females have a 3-y reproductive cycle, consisting of 10–12 months of gestation and 2 y of oocyte maturation. The embryonic growth fits the Gompertz model. Birth is in November or December, as inferred from embryo size and the presence of neonates and young of the year. Densities of S. guggenheim in LP peaked in spring and summer along the Uruguayan coast, suggesting a seasonal movement perpendicular to the shore. The reproductive pattern found suggests a population with low productivity.
Potential pressure indicators for fishing, and their data requirements
Authors: Piet G. J. , Quirijns F. J. , Robinson L. , Greenstreet S. P. R. 
Published: October 2006

Abstract
Piet, G. J., Quirijns, F. J., Robinson, L., and Greenstreet, S. P. R. 2007. Potential pressure indicators for fishing, and their data requirements. – ICES Journal of Marine Science, 64: 110–121. Indicators of fishing pressure are necessary to support an ecosystem approach to fisheries management (EAFM). We present a framework that distinguishes four levels of pressure indicators that move from being a simple description of anthropogenic activity to more precisely describing the actual pressure on the ecosystem and its components, but which require increasingly more information to be quantified. We use the example of the Dutch beam trawl fleet in the North Sea to compare these pressure indicators, as the level of information used is increased. The first level is that of fleet capacity (e.g. number of vessels), the second is fishing effort, usually expressed as the number of hours fishing or days at sea, the third incorporates fishing parameters such as the proportion of time actually spent fishing, fishing speed, or gear characteristics, e.g. the size of the beam trawl in order to determine the frequency with which an area is fished, and at the fourth level, the most informative measure of fishing pressure, annual fishing mortality, is available for a few commercial species from stock assessments. For other species, it can be calculated from the lower level pressure indicators through the incorporation of the chance of individuals of a species coming into contact with the fishing gear and the encounter mortality, which is the portion of mortality caused by the passing of the gear. Comparison of trends and absolute values shows that the pressure indicators at different levels differ considerably in their description of both present and historical fishing impact in the North Sea. Therefore, for an EAFM, we advise using the highest level pressure indicator that can be obtained with the data available.
Consumption impacts by marine mammals, fish, and seabirds on the Gulf of Maine–Georges Bank Atlantic herring (Clupea harengus) complex during the years 1977–2002
Authors: Overholtz W. J. , Link J. S. 
Published: October 2006

Abstract
Overholtz, W. J. and Link, J. S. 2007. Consumption impacts by marine mammals, fish, and seabirds on the Gulf of Maine–Georges Bank Atlantic herring (Clupea harengus) complex during the years 1977–2002. ICES Journal of Marine Science, 64: 83–96. A comprehensive study of the impact of predation during the years 1977–2002 on the Gulf of Maine–Georges Bank herring complex is presented. An uncertainty approach was used to model input variables such as predator stock size, daily ration, and diet composition. Statistical distributions were constructed on the basis of available data, producing informative and uninformative inputs for estimating herring consumption within an uncertainty framework. Consumption of herring by predators tracked herring abundance closely during the study period, as this important prey species recovered following an almost complete collapse during the late 1960s and 1970s. Annual consumption of Atlantic herring by four groups of predators, demersal fish, marine mammals, large pelagic fish, and seabirds, averaged just 58 000 t in the late 1970s, increased to 123 000 t between 1986 and 1989, 290 000 t between 1990 and 1994, and 310 000 t during the years 1998–2002. Demersal fish consumed the largest proportion of this total, followed by marine mammals, large pelagic fish, and seabirds. Sensitivity analyses suggest that future emphasis should be placed on collecting time-series of diet composition data for marine mammals, large pelagic fish, and seabirds, with additional monitoring focused on the abundance of seabirds and daily rations of all groups.
OBSTACLE IN CLEANING DRAWING COMPOUNDS FROM ENAMELING IRON*
Authors: Pfeiffer W. H. , Williamitis V. A. 
Published: October 2006

AbstractUnder certain conditions of storage, some drawing compounds (die lubricants) form or deposit a material on the surface of sheet enameling‐iron parts which is insoluble in water and alkaline cleaners but is made soluble by organic solvents. Moisture and time seem to be necessary to the mechanism, and fatty acids, or the salts of fatty acids, may be the offending materials. A method of reproducing these conditions is described and some discussion of possible remedies is offered. The use of the test method described should aid in the development of improved drawing compounds and more effective cleaning methods.