Showing papers by "Saint Louis University published in 1999"

Iterative deconvolution and receiver-function estimation

Abstract: We describe and apply an iterative, time-domain deconvolution approach to receiver-function estimation and illustrate the reliability and advantages of the technique using synthetic- and observation-based examples. The iterative technique is commonly used in earthquake time-function studies and offers several advantages in receiver-function analysis such as intuitively stripping the largest receiver-function arrivals from the observed seismograms first and then the details; long-period stability by a priori constructing the deconvolution as a sum of Gaussian pulses; and easy generalization to allow multiwaveform deconvolution for a single receiver-function estimate.

One size does not fit all: the case for tailoring print materials.

Abstract: Printed health education materials frequently consist of mass-produced brochures, booklets, or pamphlets designed for a general population audience. Although this one-size-fits-all approach might be appropriate under certain circumstances and even produce small changes at relatively modest costs, it cannot address the unique needs, interests, and concerns of different individuals. With the advent and dissemination of new communication technologies, our ability to collect information from individuals and provide feedback tailored to the specific information cellected is not only possible, but practical. The purpose of this article is to: (a) distinguish between tailored print communication and other common communication-based approaches to health education and behavior change; (b) present a theoretical and public health rationale for tailoring health information; and (c) describe the steps involved in creating and deliverin tailored print communication programs. Studies suggest computer tailoring is a promising strategy for health education and behavior change. Practitioners and researchers should understand the approach and consider the possibilities it presents for enhancing their work in disease prevention.

The hope construct, will, and ways: Their relations with self-efficacy, optimism, and general well-being.

Abstract: This investigation (N = 204) examined (a) the relations between the hope construct (Snyder, Harris et al., 1991; Snyder, Irving, & Anderson, 1991) and its two essential components, "will" and "ways," and the related constructs of self-efficacy and optimism; and (b) the ability of hope, self-efficacy, and optimism to predict general well-being. Maximum-likelihood factor analysis recovered will, ways, self-efficacy, and optimism as generally distinct and independent entities. Results of multiple regression analyses predicting well-being indicated that (a) hope taken as a whole predicts unique variance independent of self-efficacy and optimism, (b) will predicts unique variance independent of self-efficacy, and (c) ways predicts unique variance independent of optimism. Overall, findings suggest that will, ways, self-efficacy, and optimism are related but not identical constructs.

Tailoring Health Messages: Customizing Communication With Computer Technology

Abstract: Through the use of new technologies researchers and practitioners in health education and health communication can now provide health information and behavior change strategies that are customized based on the unique needs interests and concerns of different individuals. These are examples of tailored health messages which can be highly effective in assisting individuals in understanding and responding to health concerns. This book discusses the process of tailoring and its use in health communication programs. Moreover it presents a theoretical and public health rationale for tailoring and supports its position with empirical evidence. It is noted that tailored health promotion messages are any combination of information and behavior change strategies intended to reach one specific person based on characteristics that are unique to that person related to the outcome of interest and derived from an individual assessment. Hence it measures a participants needs interests and concerns and uses that information to create health messages and materials to fit that person. The step-by-step approach in creating tailoring programs is described in this book.

Linking clinical relevance and statistical significance in evaluating intra-individual changes in health-related quality of life.

Abstract: Objective.To compare the standard error of measurement (SEM) with established standards for clinically relevant intra-individual change in an evaluation of health-related quality of life.Design.Secondary analysis of data from a randomized controlled trial.Subjects.Six hundred and five outpatients wi

Further Validation and Reliability Testing of the Trust in Physician Scale

Abstract: Objectives.To further validate and assess the reliability and validity of the Trust in Physician Scale.Methods.Consecutive adult patients (n = 414) from 20 community-based, primary care practices were enrolled in a prospective, 6-month study. At enrollment, subjects completed the 11-item Trust in Ph

A nonpeptidyl mimic of superoxide dismutase with therapeutic activity in rats

Abstract: Many human diseases are associated with the overproduction of oxygen free radicals that inflict cell damage. A manganese(II) complex with a bis(cyclohexylpyridine)-substituted macrocyclic ligand (M40403) was designed to be a functional mimic of the superoxide dismutase (SOD) enzymes that normally remove these radicals. M40403 had high catalytic SOD activity and was chemically and biologically stable in vivo. Injection of M40403 into rat models of inflammation and ischemia-reperfusion injury protected the animals against tissue damage. Such mimics may result in better clinical therapies for diseases mediated by superoxide radicals.

Common genetic vulnerability for nicotine and alcohol dependence in men.

Abstract: Results: The heritability of nicotine dependence was 60.3% (95% confidence interval [CI], 55.4%-65.2%); that of alcohol dependence, 55.1% (95% CI, 49.7%-60.5%). The best-fitting model for the co-occurrence of lifetime nicotine and alcohol dependence included a substantial genetic correlation between both disorders (r = 0.68; 95% CI, 0.61-0.74) and a modest unique environmental correlation (r = 0.23; 95% CI, 0.14-0.32). Conclusions: These data suggest a common genetic vulnerability to nicotine and alcohol dependence in men. This common genetic influence may partially explain the clinical and epidemiological observations that alcoholics are often dependent smokers.

Functional-anatomical implications of the nucleus accumbens core and shell subterritories.

Abstract: The nucleus accumbens, a major part of the ventral striatum, comprises numerous subterritories and compartments, of which the core and shell appear to be dominant. Shell exhibits greater chemical neuroanatomical diversity than core and is rather directly connected to it by a robust, feed-forward, striatopallido-thalamocortico-striatal pathway. Shell and extended amygdala share afferents, but the two are distinguished by their outputs, strongly toward cortex for shell and descendent toward brain stem effector sites for extended amygdala. Shell responds independently to stimulation by excitatory amino acids and dopamine, which are more mutually permissive in the core. Accordingly, the shell responds to a broad variety of physiological and pharmacological stimuli, including psychomotor and opioid drugs. Whereas locomotion and oro-facial movements are elicitable from the shell, lesions and blockade of EAA transmission in the core reduce locomotion. It is hypothesized that core-shell has a feed-forward functional organization.

System for use in displaying images of a body part

Abstract: A system for use during a medical or surgical procedure on a body. The system generates a display representing the position of two or more body elements during the procedure based on a reference image data set generated by a scanner. The system produces a reference image of a body elements, discriminates the body elements in the images and creates an image data set representing the images of the body elements. The system produces a density image of the body element. The system modifies the image data set according to the density image of the body element during the procedure, generates a displaced image data set representing the position and geometry of the body element during the procedure, and compares the density image of the body element during the procedure to the reference image of the body element. The system also includes a display utilizing the displaced image data set generated by the processor to illustrate the position and geometry of the body element during the procedure. Methods relating to the system are also disclosed.

Smoking and diabetes.

Abstract: The objective of this review is to summarize the literature on diabetes and smoking related to epidemiological risks, efficacy and cost-effectiveness of different cessation approaches, and implications for clinical practice. Over 200 studies were reviewed, with special emphasis placed on publications within the past 10 years. Intervention studies that included patients with diabetes but did not report results separately by disease are included. Diabetes-specific studies are highlighted. There are consistent results from both cross-sectional and prospective studies showing enhanced risk for micro- and macrovascular disease, as well as premature mortality from the combination of smoking and diabetes. The general cessation literature is extensive, generally well-designed, and encouraging regarding the impact of cost-effective practical office-based interventions. In particular, system-based approaches that make smoking a routine part of office contacts and provide multiple prompts, advice, assistance, and follow-up support are effective. Although there is minimal information on the effectiveness of cessation interventions specifically for people with diabetes, there is no reason to assume that cessation intervention would be more or less effective in this population. There is a clear need to increase the frequency of smoking cessation advice and counseling for patients with diabetes given the strong and consistent data on smoking prevalence; combined risks of smoking and diabetes for morbidity, mortality, and several complications; and the proven efficacy and cost-effectiveness of cessation strategies.

Cooperation between Th1 and Th2 cells in a murine model of eosinophilic airway inflammation

Abstract: We have studied the actions of helper T lymphocyte-1 and -2 (Th1 and Th2) cells in an acute model of eosinophilic airway inflammation by infusing chicken ovalbumin-specific (OVA-specific) Th1 cells, Th2 cells, or both into unsensitized mice and challenging the mice with an OVA aerosol. OVA challenge after infusion of Th1 cells alone resulted in airway inflammation with lymphocytes and monocytes. Challenge after the infusion of Th2 cells alone resulted in minimal inflammation. In contrast, when Th1 and Th2 cells were transferred together, they cooperated to promote a robust eosinophil-predominant inflammatory response. Th1 cells alone were readily recruited to the airways after challenge, but in the absence of Th1 cells, Th2 cells did not accumulate in the airways. When transferred together, both Th1 and Th2 cells, as well as endogenous eosinophils, were effectively recruited. This recruitment was correlated with increased VCAM-1 expression in the medium- and large-sized vessels of the lung and could be inhibited by treating the mice with neutralizing antibodies to TNF-alpha or VCAM-1. These data indicate that Th2 cells require signals in addition to antigen for their effective recruitment to the airways. Th1 cells can provide these signals.

Bone repair techniques, bone graft, and bone graft substitutes.

Abstract: This paper reviews the techniques and materials (bone graft and bone graft substitutes) that currently are used to treat nonunions and bone defects. The techniques reviewed are intramedullary nailing, plating, distraction osteogenesis, and electric stimulation. Bone graft and bone graft substitutes reviewed are as follows: vascularized bone transfers; autogenous bone graft; autogenous bone marrow; dimineralized bone matrix; growth factors; calcium sulphate; calcium phosphates; and allograft. The goal of management of fractures, nonunions, and segmental bony defects, is the return of function as quickly and completely as possible. Techniques and management strategies constantly are evolving to accomplish this goal. This paper reviews the history, indications, and limitations of bone repair techniques, methods of bone grafting, and materials available as bone graft substitutes.

Requirement for the Kinase Activity of Human DNA-Dependent Protein Kinase Catalytic Subunit in DNA Strand Break Rejoining

Abstract: The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is an enormous, 470-kDa protein serine/threonine kinase that has homology with members of the phosphatidylinositol (PI) 3-kinase superfamily. This protein contributes to the repair of DNA double-strand breaks (DSBs) by assembling broken ends of DNA molecules in combination with the DNA-binding factors Ku70 and Ku80. It may also serve as a molecular scaffold for recruiting DNA repair factors to DNA strand breaks. This study attempts to better define the role of protein kinase activity in the repair of DNA DSBs. We constructed a contiguous 14-kb human DNA-PKcs cDNA and demonstrated that it can complement the DNA DSB repair defects of two mutant cell lines known to be deficient in DNA-PKcs (M059J and V3). We then created deletion and site-directed mutations within the conserved PI 3-kinase domain of the DNA-PKcs gene to test the importance of protein kinase activity for DSB rejoining. These DNA-PKcs mutant constructs are able to express the protein but fail to complement the DNA DSB or V(D)J recombination defects of DNA-PKcs mutant cells. These results indicate that the protein kinase activity of DNA-PKcs is essential for the rejoining of DNA DSBs in mammalian cells. We have also determined a model structure for the DNA-PKcs kinase domain based on comparisons to the crystallographic structure of a cyclic AMP-dependent protein kinase. This structure gives some insight into which amino acid residues are crucial for the kinase activity in DNA-PKcs.

Coronary Revascularization in Diabetic Patients A Comparison of the Randomized and Observational Components of the Bypass Angioplasty Revascularization Investigation (BARI)

Abstract: Background—Patients with treated diabetes in the randomized-trial segment of the Bypass Angioplasty Revascularization Investigation (BARI) who were randomized to initial revascularization with PTCA had significantly worse 5-year survival than patients assigned to CABG. This treatment difference was not seen among diabetic patients eligible for BARI who opted to select their mode of revascularization. We hypothesized that differences in patient characteristics, assessed and unmeasured, together with the treatment selection in the registry, at least partially account for this discrepancy. Methods and Results—Among diabetics taking insulin or oral hypoglycemic drugs at entry, angiographic and clinical presentations were comparable between randomized and registry patients. However, more registry patients were white, and registry diabetics tended to be more educated and more physically active and to report better quality of life. Procedural characteristics and in-hospital complications were comparable. The 5-y...

Evidence-based decision making in public health.

Abstract: A stronger focus on evidence-based decision making in day-to-day public health practice is needed. This article describes the rationale for this need, including (1) the inter-relationships between evidence-based medicine and evidence-based public health (EBPH); (2) commonly used analytic tools and processes; (3) keys to when public health action is warranted; (4) a strategic, six-step approach to more analytic decision making; and (5) summary barriers and opportunities for widespread implementation of EBPH. The approach outlined is being tested through a series of courses for mid-level managers in the Missouri Department of Health--initial results from a pilot test are encouraging. It is hoped that the greater use of an evidence-based framework in public health will lead to more effective programs.

Yellow Fever/Japanese Encephalitis Chimeric Viruses: Construction and Biological Properties

Abstract: A system has been developed for generating chimeric yellow fever/Japanese encephalitis (YF/JE) viruses from cDNA templates encoding the structural proteins prM and E of JE virus within the backbone of a molecular clone of the YF17D strain. Chimeric viruses incorporating the proteins of two JE strains, SA14-14-2 (human vaccine strain) and JE Nakayama (JE-N [virulent mouse brain-passaged strain]), were studied in cell culture and laboratory mice. The JE envelope protein (E) retained antigenic and biological properties when expressed with its prM protein together with the YF capsid; however, viable chimeric viruses incorporating the entire JE structural region (C-prM-E) could not be obtained. YF/JE(prM-E) chimeric viruses grew efficiently in cells of vertebrate or mosquito origin compared to the parental viruses. The YF/JE SA14-14-2 virus was unable to kill young adult mice by intracerebral challenge, even at doses of 10(6) PFU. In contrast, the YF/JE-N virus was neurovirulent, but the phenotype resembled parental YF virus rather than JE-N. Ten predicted amino acid differences distinguish the JE E proteins of the two chimeric viruses, therefore implicating one or more residues as virus-specific determinants of mouse neurovirulence in this chimeric system. This study indicates the feasibility of expressing protective antigens of JE virus in the context of a live, attenuated flavivirus vaccine strain (YF17D) and also establishes a genetic system for investigating the molecular basis for neurovirulence determinants encoded within the JE E protein.

Mechanism of increased iron absorption in murine model of hereditary hemochromatosis: Increased duodenal expression of the iron transporter DMT1

Abstract: Hereditary hemochromatosis (HH) is a common autosomal recessive disorder characterized by tissue iron deposition secondary to excessive dietary iron absorption. We recently reported that HFE, the protein defective in HH, was physically associated with the transferrin receptor (TfR) in duodenal crypt cells and proposed that mutations in HFE attenuate the uptake of transferrin-bound iron from plasma by duodenal crypt cells, leading to up-regulation of transporters for dietary iron. Here, we tested the hypothesis that HFE−/− mice have increased duodenal expression of the divalent metal transporter (DMT1). By 4 weeks of age, the HFE−/− mice demonstrated iron loading when compared with HFE+/+ littermates, with elevated transferrin saturations (68.4% vs. 49.8%) and elevated liver iron concentrations (985 μg/g vs. 381 μg/g). By using Northern blot analyses, we quantitated duodenal expression of both classes of DMT1 transcripts: one containing an iron responsive element (IRE), called DMT1(IRE), and one containing no IRE, called DMT1(non-IRE). The positive control for DMT1 up-regulation was a murine model of dietary iron deficiency that demonstrated greatly increased levels of duodenal DMT1(IRE) mRNA. HFE−/− mice also demonstrated an increase in duodenal DMT1(IRE) mRNA (average 7.7-fold), despite their elevated transferrin saturation and hepatic iron content. Duodenal expression of DMT1(non-IRE) was not increased, nor was hepatic expression of DMT1 increased. These data support the model for HH in which HFE mutations lead to inappropriately low crypt cell iron, with resultant stabilization of DMT1(IRE) mRNA, up-regulation of DMT1, and increased absorption of dietary iron.

Regrowth of axons into the distal spinal cord through a Schwann-cell-seeded mini-channel implanted into hemisected adult rat spinal cord.

Abstract: Schwann cells (SCs) have been shown to be a key element in promoting axonal regeneration after being grafted into the central nervous system (CNS). In the present study, SC-supported axonal regrowth was tested in an adult rat spinal cord implantation model. This model is characterized by a right spinal cord hemisection at the eighth thoracic segment, implantation of a SC-containing mini-channel and restoration of cerebrospinal fluid circulation by suturing the dura. We demonstrate that a tissue cable containing grafted SCs formed an effective bridge between the two stumps of the hemicord 1 month after transplantation. Approximately 10 000 myelinated and unmyelinated axons (1 : 9) per cable were found at its midpoint. In addition to propriospinal axons and axons of peripheral nervous system (PNS) origin, axons from as many as 19 brainstem regions also grew into the graft without additional treatments. Most significantly, some regenerating axons in the SC grafts were able to penetrate through the distal graft-host interface to re-enter the host environment, as demonstrated by anterograde axonal labelling. These axons coursed toward, and then entered the grey matter where terminal bouton-like structures were observed. In channels containing no SCs, limited axonal growth was seen within the graft and no axons penetrated the distal interface. These findings further support the notion that SCs are strong promotors of axonal regeneration and that the mini-channel model may be appropriate for further investigation of axonal re-entry, synaptic reconnection and functional recovery following spinal cord injury.