Showing papers by "University of Kansas published in 1997"

A survey of active network research

Abstract: Active networks are a novel approach to network architecture in which the switches (or routers) of the network perform customized computations on the messages flowing through them. This approach is motivated by both lead user applications, which perform user-driven computation at nodes within the network today, and the emergence of mobile code technologies that make dynamic network service innovation attainable. The authors discuss two approaches to the realization of active networks and provide a snapshot of the current research issues and activities. They illustrate how the routers of an IP network could be augmented to perform such customized processing on the datagrams flowing through them. These active routers could also interoperate with legacy routers, which transparently forward datagrams in the traditional manner.

Activation mechanisms of matrix metalloproteinases.

Abstract: Matrix metalloproteinases (MMPs), also called matrixins, function in the turnover of extracellular matrix components. These enzymes are considered to play important roles in embryo development, morphogenesis and tissue remodeling, and in diseases such as arthritis, periodontitis, glomerulonephritis, atherosclerosis, tissue ulceration, and in cancer cell invasion and metastasis. All MMPs are synthesized as preproenzymes and most of them are secreted from the cells as proenzymes. Thus, the activation of these proenzymes is one of the critical steps that leads to extracellular matrix breakdown. This review describes recent progress made to elucidate the activation mechanisms of pro-matrixins which include extracellular stepwise activation common to most proMMPs, cell surface activation of progelatinase A and procollagenase 3, and intracellular activation of prostromelysin 3 and pro-membrane-type-1 MMP.

Empathy and Attitudes: Can Feeling for a Member of a Stigmatized Group Improve Feelings Toward the Group?

Abstract: Results of 3 experiments suggest that feeling empathy for a member of a stigmatized group can improve attitudes toward the group as a whole. In Experiments 1 and 2, inducing empathy for a young woman with AIDS (Experiment 1) or a homeless man (Experiment 2) led to more positive attitudes toward people with AIDS or toward the homeless, respectively. Experiment 3 tested possible limits of the empathy-attitude effect by inducing empathy toward a member of a highly stigmatized group, convicted murderers, and measuring attitudes toward this group immediately and then 1-2 weeks later. Results provided only weak evidence of improved attitudes toward murderers immediately but strong evidence of improved attitudes 1-2 weeks later.

A theoretical framework for intraguild predation

Abstract: Many important issues in community ecology revolve around the interplay of competition and predation Species that compete may also be locked in predator-prey interactions, a mixture of competition and predation known as "intraguild predation" (IGP) There is growing evidence for the importance of IGP in many natural communities, yet little formal ecological theory addresses this particular blend of interactions In this article, we explore the consequences of incorporating IGP into standard models of exploitative competition and food chains (a general resource-consumer model, a Lotka-Volterra food chain model, and Schoener's exploitative competition model) Our theoretical analyses suggest a general criterion for coexistence in IGP systems: the intermediate species (the prey in intraguild predation) should be superior at exploitative competition for the shared resource, whereas the top species (the predator) should gain significantly from its consumption of the intermediate species Along gradients in en

The Development and Validation of the Children’s Hope Scale

Abstract: Assuming that children are goal-oriented, it is suggested that their thoughts are related to two components--agency and pathways. Agency thoughts reflect the perception that children can initiate and sustain action toward a desired goal; pathways thoughts reflect the children's perceived capability to produce routes to those goals. Hope reflects the combination of agentic and pathways thinking toward goals. A six-item dispositional self-report index called the Children's Hope Scale is introduced and validated for use with children ages 8-16. Results suggest that the scale evidence internal consistency, and is relatively stable over retesting. Additionally, the scale exhibits convergent, discriminant, and incremental validity. Limitations and uses of the scale are discussed.

Perspective Taking: Imagining How Another Feels Versus Imaging How You Would Feel

Abstract: Although often confused, imagining how another feels and imagining how you would feel are two distinct forms of perspective taking with different emotional consequences. The former evokes empathy; the latter, both empathy and distress. To test this claim, undergraduates listened to a (bogus) pilot radio interview with a young woman in serious need. One third were instructed to remain objective while listening; one third, to imagine how the young woman felt; and one third, to imagine how they would feel in her situation. The two imagine perspectives produced the predicted distinct pattern of emotions, suggesting different motivational consequences: Imagining how the other feels produced empathy, which has been found to evoke altruistic motivation; imagining how you would feel produced empathy, but it also produced personal distress, which has been found to evoke egoistic motivation.

Cyclodextrins: Their Future in Drug Formulation and Delivery

Abstract: Since their discovery, cyclodextrins and their ability to form inclusion complexes have fascinated chemists, formulators and recently, entrepreneurs. This mini-review has as its objective, a critical assessment of the current status of cyclodextrins in the formulation and delivery of pharmaceuticals and commentary on their potential future uses. The emphasis will be on answers to common questions often asked of pharmaceutical scientists working in this area. Why use cyclodextrins for drug solubilization and stabilization when alternative techniques are available? Why the greater interest in modified cyclodextrins and not the parent cyclodextrins? If a drug forms a strong cyclodextrin inclusion complex, how is the drug releasedin vivo? Does the injection of a cyclodextrin/drug complex alter the pharmacokinetics of the drug? Are there drug products on the market which contain cyclodextrins? What is the regulatory status of cyclodextrins? Although definitive answers to all these questions are not possible at this time, many of these questions are answerable, and educated and informed responses are possible for the rest.

Mechanism of inhibition of the human matrix metalloproteinase stromelysin-1 by TIMP-1.

Abstract: Matrix metalloproteinases (MMPs) are zinc endopeptidases that are required for the degradation of extracellular matrix components during normal embryo development, morphogenesis and tissue remodelling. Their proteolytic activities are precisely regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs). Disruption of this balance results in diseases such as arthritis, atherosclerosis, tumour growth and metastasis. Here we report the crystal structure of an MMP-TIMP complex formed between the catalytic domain of human stromelysin-1 (MMP-3) and human TIMP-1. TIMP-1, a 184-residue protein, has the shape of an elongated, contiguous wedge. With its long edge, consisting of five different chain regions, it occupies the entire length of the active-site cleft of MMP-3. The central disulphide-linked segments Cys 1-Thr 2-Cys 3-Val 4 and Ser 68-Val 69 bind to either side of the catalytic zinc. Cys 1 bidentally coordinates this zinc, and the Thr-2 side chain extends into the large specificity pocket of MMP-3. This unusual architecture of the interface between MMP-3 and TIMP-1 suggests new possibilities for designing TIMP variants and synthetic MMP inhibitors with potential therapeutic applications.

Is Empathy-Induced Helping Due to Self–Other Merging?

Abstract: Two experiments tested the idea that empathy-induced helping is due to self–other merging. To manipulate empathy, half of the participants in each experiment received instructions to remain objective while hearing about a young woman in need (low-empathy condition), and half received instructions to

Phantom materials for elastography

Abstract: Acoustic and mechanical properties are reported for gelatin materials used to construct tissue-like phantoms for elasticity imaging (elastography). A device and procedure for measuring elastic properties are described. The measured compression forces were comparable to results obtained from finite element analysis when linear elastic media are assumed. Also measured were the stress relaxation, temporal stability, and melting point of the materials. Aldehyde concentration was used to increase the stiffness of the gelatin by controlling the amount of collagen cross-linking. A broad range of tissue-like elastic properties was achieved with these materials, although gels continued to stiffen for several weeks. The precision for elastic modulus measurements ranged from less than 0.1% for 100 kPa samples to 8.9% for soft (<10 kPa), sticky samples.

High‐frequency unilateral thalamic stimulation in the treatment of essential and parkinsonian tremor

Abstract: Pharmacologic treatment for essential tremor and the tremor of Parkinson's disease is often inadequate. Stereotaxic surgery, such as thalamotomy, can effectively reduce tremors. We performed a multicenter trial of unilateral high-frequency stimulation of the ventral intermedius nucleus of the thalamus in 29 patients with essential tremor and 24 patients with Parkinson's disease, using a blinded assessment at 3 months after surgery to compare clinical rating of tremor with stimulation ON with stimulation OFF and baseline and a 1-year follow-up. Six patients were not implanted because of lack of intraoperative tremor suppression (2 patients), hemorrhage (2 patients), withdrawal of consent (1 patient), and persistent microthalamotomy effect (1 patient). A significant reduction in both essential and parkinsonian tremor occurred contralaterally with stimulation. Patients reported a significant reduction in disability. Measures of function were significantly improved in patients with essential tremor. Complications related to surgery in implanted patients were few. Stimulation was commonly associated with transient paresthesias. Other adverse effects were mild and well tolerated. Efficacy was not reduced at 1 year. Chronic high-frequency stimulation is safe and highly effective in ameliorating essential and parkinsonian tremor.

Bacterial cell division and the z ring

Abstract: Bacterial cell division occurs through the formation of an FtsZ ring (Z ring) at the site of division. The ring is composed of the tubulin-like FtsZ protein that has GTPase activity and the ability to polymerize in vitro. The Z ring is thought to function in vivo as a cytoskeletal element that is analogous to the contractile ring in many eukaryotic cells. Evidence suggests that the Z ring is utilized by all prokaryotic organisms for division and may also be used by some eukaryotic organelles. This review summarizes our present knowledge about the formation, function, and evolution of the Z ring in prokaryotic cell division.

A New Version of the Rule Induction System LERS

Abstract: A new version of the rule induction system LERS is described and compared with the old version of LERS. Experiments were done for comparison of performance for both versions of LERS and the two other rule-induction systems: AQ15 and C4.5. The new LERS system performance is fully comparable with performance of the other two systems.

A Comparison of the Performance of Children With and Without Autism on the Sensory Profile

Abstract: Objective The purpose of this study was to determine whether the Sensory Profile discriminates between children with and without autism and which items on the profile best discriminate between these groups. Method Parents of 32 children with autism aged 3 to 13 years and of 64 children without autism aged 3 to 10 years completed the Sensory Profile. A descriptive analysis of the data set of children with autism identified the distribution of responses on each item. A multivariate analysis of covariance (MANCOVA) of each category of the Sensory Profile identified possible differences among subjects without autism, with mild or moderate autism, and with severe autism. Follow-up univariate analyses were conducted for any category that yielded a significant result on the MANCOVA: Results Eight-four of 99 items (85%) on the Sensory Profile differentiated the sensory processing skills of subjects with autism from those without autism. There were no group differences between subjects with mild or moderate autism and subjects with severe autism. Conclusion The Sensory Profile can provide information about the sensory processing skills of children with autism to assist occupational therapists in assessing and planning intervention for these children.

The D3 Dopamine Receptor: Neurobiology and Potential Clinical Relevance

Abstract: Dopamine is a major neurotransmitter in the central nervous system. Receptors for this catecholamine are of considerable interest, as they are the principal target of drugs employed in the treatment of neuropsychiatric disorders such as schizophrenia and Parkinson’s disease. Before 1990, the

Comet Hyakutake x‐ray source: Charge transfer of solar wind heavy ions

Abstract: Recently, Lisse et al. (1996) reported on exciting observations by the Rontgen X-ray satellite (ROSAT) of x-ray and extreme ultraviolet emissions from comet C/Hyakutake 1996 B2. The spatial distribution of the emissions was displaced sunward of the nucleus and the spatial extent was about 105 km. Lisse et al. (1996) suggested that the emission could be explained by thermal bremsstrahlung associated with hot electrons, possibly due to solar wind interaction effects. In the present paper, an alternate emission mechanism is proposed. The solar wind contains a large number of minor/heavy ion species with a range of charge states, such as O6+, C5+, N5+, and Si10+. These ions will readily charge transfer with cometary neutrals, producing ions which can be highly excited and consequently emit photons in the extreme ultraviolet and x-ray part of the spectrum. The photon emission rate is proportional to the solar wind heavy ion flux and hence to the solar wind flux and, with some assumptions concerning the solar wind velocity, to the solar wind number density. The emission rate should be greatest downstream of the bow shock along the sun-comet axis in agreement with the observed spatial distribution. The x-ray images are really images of the line of sight integration of the solar wind density convoluted with the cometary neutral density. A total EUV/x-ray luminosity for comet Hyakutake from this charge transfer mechanism agrees with the observed luminosity of 4 × 1015 ergs s−1 within a factor of two.

The design, performance, and analysis of slug tests

Abstract: Introduction The Slug Test-What Is It? Why Is It So Prevalent? But Skepticism Abounds... Purpose of this Book Outline A Short Word on Terminology The Design of Slug Tests Chapter Overview Well Construction Well Development Verification of Conventional Theory Design Guidelines The Performance of Slug Tests Chapter Overview Slug-Test Equipment Test Initiation Degree of Head Recovery Performance Guidelines Pre-analysis Processing Chapter Overview Pre-analysis Data Processing Pre-analysis Processing Guidelines The Analysis of Slug Tests-Confined Formations Chapter Overview Theoretical Models for the Analysis of Response Data Slug Tests in Confined Formations The Analysis of Slug Tests-Unconfined Formations Chapter Overview Slug Tests in Unconfined Formations The Analysis of Slug Tests-Low-Conductivity Formations Chapter Overview Slug Tests in Log-Conductivity Formations The Analysis of Slug Tests-High-Conductivity Formulations Chapter Overview Slug Tests in High-Conductivity Formations The Analysis of Slug Tests-Well Skins Chapter Overview Slug Tests in the Presence of Well Skins The Analysis of Slug Tests-Multiwell Tests Chapter Overview Multiwell Slug Tests The Analysis of Slug Tests-Additional Issues Chapter Overview Slug Tests in Fractured Formations Slug Tests in Naturally Heterogeneous Formations Assessment of Prospective Observation Wells The Analysis of Slug Tests-Guidelines Chapter Overview Analysis Guidelines Final Comments Appendix A: A Brief Discussion of Analysis Software Appendix B: List of Notations References NTI/Sales copy (Already routed/approved)

A prospective, longitudinal, multicenter study of service utilization and costs in fibromyalgia

Abstract: Objective. To study, for the first time, service utilization and costs in fibromyalgia, a prevalent syndrome associated with high levels of pain, functional disability, and emotional distress. Methods. Five hundred thirty-eight fibromyalgia patients from 6 rheumatology centers were enrolled in a 7-year prospective study of fibromyalgia outcome. Patients were assessed every 6 months with validated, mailed questionnaires which included questions regarding fibromyalgia symptoms and severity, utilization of services, and work disability. Results. Fibromyalgia patients averaged almost 10 outpatient medical visits per year, and when nontraditional treatments were considered, this number increased to ∼1 visit per month. Patients were hospitalized at a rate of 1 hospitalization every 3 years. In each 6-month study period, patients used a mean of 2.7 fibromyalgia-related drugs. Costs increased over the course of the study. The mean yearly per-patient cost in 1996 dollars was $2,274. However, results were skewed by high utilizers, and many patients used few services and had limited costs. Total costs and utilization were independently associated with the number of selfreported comorbid or associated conditions, functional disability, and global disease severity. Compared with patients with other rheumatic disorders, those with fibromyalgia were more likely to have lifetime surgical interventions, including back or neck surgery, appendectomy, carpal tunnel surgery, gynecologic surgery, abdominal surgery, and tonsillectomy, and were more likely than other rheumatic disease patients to report comorbid or associated conditions. Almost 50% of hospitalizations occurring during the study were related to fibromyalgia-associated symptoms. Conclusion. The average yearly cost for service utilization among fibromyalgia patients is $2,274. Fibromyalgia patients have high lifetime and current rates of utilization of all types of medical services. They report more symptoms and comorbid or associated conditions than patients with other rheumatic conditions, and symptom reporting is linked to service utilization and, to a lesser extent, functional disability and global disease severity.

Safety and Efficacy of Omacor in Severe Hypertriglyceridemia

Abstract: Background Severe hypertriglyceridemia is a risk factor for acute pancreatitis, therefore decreasing serum triglyceride concentrations is an important component of risk management. Omega-3 fatty ac...

Clinically relevant pharmacology of selective serotonin reuptake inhibitors. An overview with emphasis on pharmacokinetics and effects on oxidative drug metabolism.

Abstract: This paper presents an overview of the clinically relevant pharmacology of selective serotonin reuptake inhibitors (SSRIs) with an emphasis on their pharmacokinetics and effects on cytochrome P450 (CYP) enzymes. The SSRIs are potent inhibitors of the neuronal reuptake pump for serotonin (5-hydroxytryptamine; 5-HT) and have minimal effects on a number of other sites of actions (e.g. neuroreceptors and fast sodium channels). For this reason, drugs in this class have remarkable similarity as regards acute and maintenance antidepressant efficacy and tolerability profile.

Gender- and race-based standards of competence: lower minimum standards but higher ability standards for devalued groups

Abstract: Stereotypes may influence judgment via assimilation, such that individual group members are evaluated consistently with stereotypes, or via contrast, such that targets are displaced from the overall group expectation. Two models of judgment--the shifting standards model and status characteristics theory--provide some insight into predicting and interpreting these apparently contradictory effects. In 2 studies involving a simulated applicant-evaluation setting, we predicted and found that participants set lower minimum-competency standards, but higher ability standards, for female than for male and for Black than for White applicants. Thus, although it may be easier for low- than high-status group members to meet (low) standards, these same people must work harder to prove that their performance is ability based.

Hope: An individual motive for social commerce.

Abstract: The authors suggest that people of all ages are goal oriented and that 2 related thought processes typically accompany this goal-related thinking. First, there are pathway thoughts, which tap the perceived capability to generate 1 or more workable routes to desired goals. Second, there are agentic thoughts, which reflect the perception that one can initiate and sustain movement toward a goal along the given pathways. Together, pathway and agentic goal-directed thinking define hope in the present model. After describing how hope develops, the self-report instruments for measuring hope in children and adults are reviewed. How hope is sustained in the context of larger groups is explored, and the importance of shared goals as the foundation of communal hope is described.

Increased rates of fibromyalgia following cervical spine injury. A controlled study of 161 cases of traumatic injury.

Abstract: Objective. To study the relationship between cervical spine injury and the development of fibromyalgia syndrome (FMS). Methods. One hundred two patients with neck injury and 59 patients with leg fractures (control group) were assessed for nonarticular tenderness and the presence of FMS. A count of 18 tender points was conducted by thumb palpation, and tenderness thresholds were assessed by dolorimetry at 9 tender sites. All patients were interviewed about the presence and severity of neck and FMS-related symptoms. FMS was diagnosed using the American College of Rheumatology 1990 criteria. Additional questions assessed measures of physical functioning and quality of life (QOL). Results. Although no patient had a chronic pain syndrome prior to the trauma, FMS was diagnosed following injury in 21.6% of those with neck injury versus 1.7% of the control patients with lower extremity fractures (P = 0.001). Almost all symptoms were more common and severe in the group with neck injury. FMS was noted at a mean of 3.2 months (SD 1.1) after the trauma. Neck injury patients with FMS (n = 22) had more tenderness, had more severe and prevalent FMS-related symptoms, and reported lower QOL and more impaired physical functioning than did those without FMS (n = 80). In spite of the injury or the presence of FMS, all patients were employed at the time of examination. Twenty percent of patients with neck injury and 24% of patients with leg fractures filed an insurance claim. Claims were not associated with the presence of FMS, increased FMS symptoms, pain, or impaired functioning. Conclusion. FMS was 13 times more frequent following neck injury than following lower extremity injury. All patients continued to be employed, and insurance claims were not increased in patients with FMS.

In a very different voice: unmasking moral hypocrisy.

Abstract: Across 3 small studies, 80 female undergraduates were confronted with the dilemma of deciding whom-themselves or another research participant-to assign to a positive consequences task, leaving the other to do a dull, boring task. In Study 1, where morality was not mentioned, 16 of 20 assigned themselves to the positive consequences task, even though in retrospect only 1 said this was moral. In Studies 2 and 3, a moral strategy was suggested: either flipping a coin or accepting task assignment by the experimenter. In Study 2, 10 of 20 participants flipped a coin, but of these, 9 assigned themselves the positive consequences task. In Study 3, participants were significantly more likely to accept the experimenter's assignment when it gave them the positive consequences task. Overall, results suggested motivation to appear moral yet still benefit oneself. Such motivation is called moral hypocrisy.

Inaccuracy of the International Classification of Diseases (ICD-9-CM) in identifying the diagnosis of ischemic cerebrovascular disease

Abstract: In administrative databases the International Classification of Diseases, Version 9, Clinical Modification (ICD-9-CM) is often used to identify patients with specific diagnoses. However, certain conditions may not be accurately reflected by the ICD-9 codes. We assessed the accuracy of ICD-9 coding for cerebrovascular disease by comparing ICD-9 codes in an administrative database with clinical findings ascertained from medical record abstractions. We selected patients with ICD-9 diagnostic codes of 433 through 436 (in either the primary or secondary positions) from an administrative database of patients hospitalized in five academic medical centers in 1992. Medical records of the selected patients were reviewed by trained medical abstractors, and the patients' clinical conditions during the admission (stroke, TIA, asymptomatic) were recorded, as well as any history of cerebrovascular symptoms. Results of the medical record review were compared with the ICD-9 codes from the administrative database. More than 85% of those patients with the ICD-9 code 433 were asymptomatic for the index admission. More than one-third of these asymptomatic patients did not undergo either cerebral angiography or carotid endarterectomy. For ICD-9 code 434, 85% of patients were classified as having a stroke and for ICD-9 code 435, 77% had TIAs. For code 436, 77% of patients were classified as having strokes. Limiting the identifying ICD-9 code to the primary position increased the likelihood of agreement with the medical record review. The ICD-9 coding scheme may be inaccurate in the classification of patients with ischemic cerebrovascular disease. Its limitations must be recognized in the analyses of administrative databases selected by using ICD-9 codes 433 through 436.

Effect of recombinant human insulin-like growth factor-I on progression of ALS A placebo-controlled study

Abstract: The objective of this study was to investigate the safety and efficacy of recombinant human insulinlike growth factor-I (rhIGF-I) in the treatment of sporadic ALS A double-blind, placebo-controlled, randomized study of 266 patients was conducted at eight centers in North America Placebo or rhIGF-I (005 mg/kg/day or 010 mg/kg/day) was administered for 9 months The primary outcome measure was disease symptom progression, assessed by the rate of change (per patient slope) in the Appel ALS rating scale total score The Sickness Impact Profile (SIP), a patient-perceived, health-related quality of life assessment, was a secondary outcome variable Progression of functional impairment in patients receiving high-dose (010 mg/kg/day) rhIGF-I was 26% slower than in patients receiving placebo (p = 001) The high-dose treatment group was less likely to terminate the study due to protocol-defined markers of disease symptom progression, and members in this group exhibited a slower decline in quality of life, as assessed by the SIP Patients receiving 005 mg/kg/day of rhIGF-I exhibited trends similar to those associated with high-dose treatment, suggesting a dose-dependent response The incidence of clinically significant adverse experiences was comparable among the three treatment groups Recombinant human insulin-like growth factor-I slowed the progression of functional impairment and the decline in health-related quality of life in patients with ALS with no medically important adverse effects

Sulfation and sulfotransferases 5: the importance of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) in the regulation of sulfation.

Abstract: Sulfation is the transfer of a sulfate group from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to a substrate that is catalyzed by a family of sulfotransferase enzymes. Many different endogenous and xenobiotic molecules are substrates for the sulfotransferases; sulfation affects many different physiological processes, including: 1) deactivation and bioactivation of xenobiotics, 2) inactivation of hormones and catecholamines, 3) structure and function of macromolecules, and 4) elimination of end products of catabolism. PAPS is the obligate cosubstrate that is synthesized in tissues to make available an "activated form" of sulfate for the sulfation reaction. PAPS participation in the reaction is dependent on its availability, which in turn is dependent on its synthesis, degradation, and ultimately its utilization in the sulfation reaction itself. PAPS synthesis is dependent on the availability of sulfate and on the activity of the two enzymes of its synthesis, ATP-sulfurylase and APS-kinase. Although the ki...