Publications by authors named "Elizabeth Erickson"

29 Publications

  • Page 1 of 1

Weight-Related Behaviors of Children with Obesity during the COVID-19 Pandemic.

Child Obes 2021 Apr 26. Epub 2021 Apr 26.

Department of Population Health Sciences, Duke University School of Medicine, Durham, NC, USA.

During the coronavirus disease 2019 (COVID-19) pandemic, children and families have had to adapt their daily lives. The purpose of this study was to describe changes in the weight-related behaviors of children with obesity after the onset of the COVID-19 pandemic. Semistructured interviews ( = 51) were conducted from April to June 2020 with parents of children with obesity. Families were participants in a randomized trial testing a clinic-community pediatric obesity treatment model. During interviews, families described their experience during the COVID-19 pandemic, with a particular emphasis on children's diet, physical activity, sleep, and screen time behaviors. Rapid qualitative analysis methods were used to identify themes around changes in children's weight-related behaviors. The mean child age was 9.7 (±2.8) years and the majority of children were Black (46%) or Hispanic (39%) and from low-income families (62%). Most parent participants were mothers (88%). There were differences in the perceived physical activity level of children, with some parents attributing increases in activity or maintenance of activity level to increased outdoor time, whereas others reported a decline due to lack of outdoor time, school, and structured activities. Key dietary changes included increased snacking and more meals prepared and consumed at home. There was a shift in sleep schedules with children going to bed and waking up later and an increase in leisure-based screen time. Parents played a role in promoting activity and managing children's screen time. The COVID-19 pandemic has created unique lifestyle challenges and opportunities for lifestyle modification. Clinical Trials ID: NCT03339440.
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http://dx.doi.org/10.1089/chi.2021.0038DOI Listing
April 2021

Clinician Experiences With Reach Out and Read: An Exploratory Qualitative Analysis.

Acad Pediatr 2021 Jan 29. Epub 2021 Jan 29.

Department of Pediatrics, Section of General and Community Pediatrics, University of Oklahoma Health Sciences Center (MC Grabe and M Dunlap), Oklahoma City, Okla.

Background: Enhanced literacy and increased vocabulary related to Reach Out and Read (ROR) are well described. Less is known about clinicians' experience with the program.

Objective: Understand clinician experiences of implementing ROR.

Design/methods: This study was a collaboration between ROR and the Academic Pediatric Association's Continuity Research Network. Participants completed an anonymous online survey to evaluate Literacy Promotion activities and training, and were asked "What has been the most meaningful experience you have encountered with using ROR?" and "Is there anything else you would like to add?" Responses were evaluated by researchers and 4 themes were generated through discussion. All responses were divided and coded by researchers working in pairs and subsequently by all researchers until consensus was reached. Data were organized into themes.

Findings: Responses were provided by 592 (35%) participants. Qualitative analysis revealed benefits to participation in ROR within 4 themes: 1) Child/Family Impact (60%): "Seeing a child read for the first time" 2) Physician Impact (16%): "I... use the books... to connect with patients." 3) Impact on clinic practice (25%): "I... enjoy modeling for parents and use the books to assess... development" 4) Social Determinants of Health (2%): "The books... are an invaluable resource to our under-served population."

Conclusion: Clinicians who implement ROR report positive impact on patients, families, and their own satisfaction and methods in practice. Clinicians value that the program addresses social determinants of health and facilitates developmental surveillance. Further study is needed to understand how clinician's perspectives affect and are affected by their experiences.
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http://dx.doi.org/10.1016/j.acap.2021.01.011DOI Listing
January 2021

Influence of Early Lactation Assistance on Inpatient Exclusive Breastfeeding Rates.

J Hum Lact 2020 Sep 14:890334420957967. Epub 2020 Sep 14.

12277 Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA.

Background: Human milk feeding reduces the incidence and costs of several maternal and childhood illnesses. Initiation and success of human milk feeding are influenced by race, socioeconomic status, and family support. The influence of early in-hospital lactation assistance in breastfeeding success has been not well described.

Research Aims: We aimed to determine how suspected known factors influencing breastfeeding success influence in-hospital human milk feeding rates. Second, we aimed to examine how timing of lactation assistance is related to success of human milk feeding during the newborn hospitalization for healthy infants.

Methods: We conducted a retrospective cohort study of term infants born between January 1, 2014 and December 31, 2016 at a large tertiary academic hospital. We considered "success" to be 100% human milk feeding during the birth hospitalization, and compared differences in success by demographics, payor, race, and initial feeding preference. Influences of lactation assistance on success were analyzed using multivariable logistic regression.

Results: Mean success with exclusive human milk feeding among 7,370 infants was 48.9%, ( = 3,601). Successful participants were more likely to be 39-40 weeks' gestation (64.9%, = 2,340), non-Hispanic/non-Latino (80.0%, = 2,882), and using private insurance (69.2%, = 2,491). Participants who had early feeding assisted by an International Board Certified Lactation Consultant (IBCLC) before being fed any formula were more likely to be successful than participants who had a feeding assisted by a non-IBCLC nurse (80% vs. 40% respectively).

Conclusions: Success for exclusive human milk feeding during newborn hospitalization is strongly associated with several factors. Early intervention with IBCLCs can greatly improve breastfeeding success.
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http://dx.doi.org/10.1177/0890334420957967DOI Listing
September 2020

Literacy Promotion Training and Implementation in Pediatric Continuity Clinics.

Acad Pediatr 2020 Sep - Oct;20(7):1013-1019. Epub 2020 Apr 15.

University of Oklahoma Health Sciences Center, Department of Pediatrics, Section of General and Community Pediatrics (A Caldwell, MC Garbe, and M Dunlap), Oklahoma City, Okla.

Background: Despite endorsement by the American Academy of Pediatrics, there are no national data on literacy promotion (LP) training and behaviors.

Objective: To describe LP training experiences and behaviors of pediatric and internal medicine/pediatrics residents and faculty nationally, and the association between LP training and behaviors.

Methods: The Academic Pediatric Association's Continuity Research Network and Reach Out and Read National Center sent an online survey to faculty and residents at participating Continuity Research Network clinics. Respondents were asked about LP training experiences and behaviors. Data were analyzed using descriptive statistics, chi-square tests, and logistic regression modeling.

Results: 473 faculty and 1216 residents at 42 institutions participated. More faculty than residents reported completing online Reach Out and Read training (63% vs 45%, P < .0001). More residents reported learning in clinic from others (92% vs 89%, P = .04). Training experiences did not differ otherwise. More faculty reported providing anticipatory guidance (87% vs 77%, P < .0001); modeling shared reading (69% vs 45%, P < .0001); and using books for developmental assessment (80% vs 62%, P < .0001). Both groups (97%) reported distributing books. The training modality most often endorsed as "very/extremely influential" was learning in clinic from others. Some LP behaviors were associated more strongly with online training while others were associated more strongly with in-person training.

Conclusions: Online training and in-person training are both associated with high quality delivery of LP. Faculty members are more likely to have completed online training and to report engaging in the full range of recommended LP behaviors. These data have implications for LP training.
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http://dx.doi.org/10.1016/j.acap.2020.04.008DOI Listing
April 2020

Environmental Heat Exposure and Heat-Related Symptoms in United States Coast Guard Deepwater Horizon Disaster Responders.

Disaster Med Public Health Prep 2019 06 6;13(3):561-569. Epub 2018 Nov 6.

1Department of Preventive Medicine and Biostatistics,F. Edward Hebert School of Medicine,Uniformed Services University of the Health Sciences,Bethesda,Maryland.

Objectives: The response to the 2010 Deepwater Horizon oil spill was impacted by heat. We evaluated the association between environmental heat exposure and self-reported heat-related symptoms in US Coast Guard Deepwater Horizon disaster responders.

Methods: Utilizing climate data and postdeployment survey responses from 3648 responders, we assigned heat exposure categories based on both wet bulb globe temperature (WBGT) and heat index (HI) measurements (median, mean, maximum). We calculated prevalence ratios (PRs) and 95% confidence intervals (CIs) via adjusted Poisson regression models with robust error variance to estimate associations with reported heat-related symptoms. We also evaluated the association between use of personal protective equipment (PPE) and heat-related symptoms.

Results: Those in the highest WBGT median-based heat exposure category had increased prevalence of heat-related symptoms compared to those in the lowest category (PR=2.22 [95% CI: 1.61, 3.06]), and there was a significant exposure-response trend (P<.001). Results were similar for exposure categories based on WBGT and HI metrics. Analyses stratified by use of PPE found significantly stronger associations between environmental heat exposure and heat-related symptoms in those who did not use PPE (PR=2.23 [95% CI: 1.10, 4.51]) than in those who did (PR=1.64 [95% CI: 1.14, 2.36]).

Conclusions: US Coast Guard Deepwater Horizon disaster responders who experienced higher levels of environmental heat had higher prevalences of heat-related symptoms. These symptoms may impact health, safety, and mission effectiveness. As global climate change increases the frequency of disasters and weather extremes, actions must be taken to prevent heat-related health impacts among disaster responders. (Disaster Med Public Health Preparedness. 2019;13:561-569).
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http://dx.doi.org/10.1017/dmp.2018.120DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6762031PMC
June 2019

Interventions to Prevent Falls and Fractures in Community-Dwelling Older Adults.

Am Fam Physician 2018 08;98(4):253-255

Uniformed Services University of the Health Sciences, USA.

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August 2018

Impact of a Modified Version of Baby-Led Weaning on Dietary Variety and Food Preferences in Infants.

Nutrients 2018 Aug 15;10(8). Epub 2018 Aug 15.

Department of Medicine, University of Otago, Dunedin 9054, New Zealand.

The aim of this study was to determine whether food variety and perceived food preferences differ in infants following baby-led instead of traditional spoon-feeding approaches to introducing solids. A total of 206 women (41.3% primiparous) were recruited in late pregnancy from a single maternity hospital (response rate 23.4%) and randomized to Control (n = 101) or BLISS (n = 105) groups. All participants received government-funded Well Child care. BLISS participants also received support to exclusively breastfeed to 6 months and three educational sessions on BLISS (Baby-Led Weaning, modified to reduce the risk of iron deficiency, growth faltering, and choking) at 5.5, 7, and 9 months. Food variety was calculated from three-day weighed diet records at 7, 12, and 24 months. Questionnaires assessed infant preference for different tastes and textures at 12 months, and for 'vegetables', 'fruit', 'meat and fish', or 'desserts' at 24 months. At 24 months, 50.5% of participants provided diet record data, and 78.2% provided food preference data. BLISS participants had greater variety in 'core' (difference in counts over three days, 95% CI: 1.3, 0.4 to 2.2), 'non-core' (0.6, 0.2 to 0.9), and 'meat and other protein' (1.3, 0.8 to 1.9) foods at 7 months, and in 'fruit and vegetable' foods at 24 months (2, 0.4 to 3.6). The only differences in perceived food preferences observed were very small (i.e., <5% difference in score, at 12 months only). Infants following the modified Baby-Led Weaning were exposed to more varied and textured foods from an early age, but only an increased variety in 'fruit and vegetable' intake was apparent by two years of age.
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http://dx.doi.org/10.3390/nu10081092DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115843PMC
August 2018

Insomnia and motor vehicle accident-related injuries, active component, U.S. Armed Forces, 2007-2016.

MSMR 2017 Dec;24(12):2-11

Insomnia is the most common sleep disorder in adults, and its incidence is increasing in the U.S. Armed Forces. A potential consequence of insomnia (including medications used to treat it) is increased risk of motor vehicle accidents (MVAs), which cause significant morbidity and mortality in service members. To examine the relationship between insomnia and MVA-related injuries in the U.S. Armed Forces, this retrospective cohort study compared incidence rates of MVA-related injuries from 2007 through 2016 between service members with diagnosed insomnia and an unexposed cohort. After adjustment for multiple covariates, service members with insomnia had more than double the rate of MVA-related injuries, compared to service members without insomnia (adjusted incidence rate ratio: 2.08; 95% CI: 1.95-2.22). A subanalysis of service members with insomnia during 2014-2016 found no difference in risk of MVA-related injury based on days' supply of sleep aid medications prescribed in 365 days following insomnia diagnosis. Insomnia is an important potential risk factor for MVAs in the military. Sleep health should be a component of MVA prevention efforts.
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December 2017

Awake High-Flow Extracranial to Intracranial Bypass for Complex Cerebral Aneurysms: Institutional Clinical Trial Results.

World Neurosurg 2017 Sep 14;105:557-567. Epub 2017 Apr 14.

Saint Louis University Center for Outcomes Research, St. Louis, Missouri, USA.

Objective: Assess the potential added benefit to patient outcomes of "awake" neurological testing when compared with standard neurophysiologic testing performed under general endotracheal anesthesia.

Methods: Prospective study of 30 consecutive adult patients who underwent awake high flow extracranial to intracranial (HFEC-IC) bypass. Clinical neurological and neurophysiologic findings were recorded. Primary outcome measures were the incidence of stroke/cerebrovascular accident (CVA), length of stay, discharge to rehabilitation, 30-day modified Rankin scale score, and death. An analysis was also performed of a retrospective control cohort (n = 110 patients who underwent HFEC-IC for internal carotid artery (ICA) aneurysms under standard general endotracheal anesthesia).

Results: Five patients (16.6%) developed clinical awake neurological changes (4, contralateral hemiparesis; 1, ipsilateral visual changes) during the 10-minute ICA occlusion test. These patients had 2 kinks in the graft, 1 vasospasm, 1 requiring reconstruction of the distal anastomosis, and 1 developed blurring of vision that reversed after the removal of the distal permanent clip on the ICA. Three of these 5 patients had asynchronous clinical "awake" neurological and neurophysiologic changes. Two patients (7%) developed CVA. Median length of stay was 4 days. Twenty-eight of 30 patients were discharged to home. Median modified Rankin scale score was 1. There were no deaths in this series. Absolute risk reduction in the awake craniotomy group (n = 30) relative to control retrospective group (n = 110) was 7% for CVA, 9% for discharge to rehabilitation, and 10% for graft patency.

Conclusions: Temporary ICA occlusion during HFEC-IC bypass for ICA aneurysms in conjunction with awake intraoperative clinical testing was effective in detecting a subset of patients (n = 3, 10%) in whom neurological deficit was not detected by neurophysiologic monitoring alone.
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http://dx.doi.org/10.1016/j.wneu.2017.04.016DOI Listing
September 2017

Breakfast frequency and quality may affect glycemia and appetite in adults and children.

J Nutr 2011 Jan 1;141(1):163-8. Epub 2010 Dec 1.

Division of Epidemiology and Community Health, School of Public Health, Minneapolis, MN 55454, USA.

Observational studies of breakfast frequency in children and adults suggest an inverse (protective) association between the frequency of eating breakfast and the risk for obesity and chronic diseases such as type 2 diabetes. More prospective studies with stronger designs are needed, as are experimental studies on this topic. In addition, above and beyond breakfast frequency, the roles of dietary quality and composition need to be studied in the context of eating or skipping breakfast. Experimental studies are also necessary to rigorously test causality and biological mechanisms. Therefore, we conducted 2 pilot experimental studies to examine some of the effects of breakfast skipping and breakfast composition on blood glucose and appetite in children and adults. Our results suggest that breakfast frequency and quality may be related in causal ways to appetite controls and blood sugar control, supporting the hypothesis that the breakfast meal and its quality may have important causal implications for the risk of obesity and type 2 diabetes.
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http://dx.doi.org/10.3945/jn.109.114405DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001239PMC
January 2011

Simulated reflux decreases vocal fold epithelial barrier resistance.

Laryngoscope 2010 Aug;120(8):1569-75

Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, Indiana, USA.

Objectives/hypothesis: The vocal fold epithelium provides a barrier to the entry of inhaled and systemic challenges. However, the location of the epithelium makes it vulnerable to damage. Past research suggests, but does not directly demonstrate, that exposure to gastric reflux adversely affects the function of the epithelial barrier. Understanding the nature of reflux-induced epithelial barrier dysfunction is necessary to better recognize the mechanisms for vocal fold susceptibility to this disease. Therefore, we examined the effects of physiologically relevant reflux challenges on vocal fold transepithelial resistance and gross epithelial and subepithelial appearance.

Study Design: Ex vivo, mixed design with between-group and repeated-measures analyses.

Methods: Healthy, native porcine vocal folds (N = 52) were exposed to physiologically relevant acidic pepsin, acid-only, or pepsin-only challenges and examined with electrophysiology and light microscopy. For all challenges, vocal folds exposed to a neutral pH served as control.

Results: Acidic pepsin and acid-only challenges, but not pepsin-only or control challenges significantly reduced transepithelial resistance within 30 minutes. Reductions in transepithelial resistance were irreversible. Challenge exposure produced minimal gross changes in vocal fold epithelial or subepithelial appearance as evidenced by light microscopy.

Conclusions: These findings demonstrate that acidic environments characteristic of gastric reflux compromise epithelial barrier function without gross structural changes. In healthy, native vocal folds, reductions in transepithelial resistance could reflect reflux-related epithelial disruption. These results might guide the development of pharmacologic and therapeutic recommendations for patients with reflux, such as continued acid-suppression therapy and patient antireflux behavioral education.
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http://dx.doi.org/10.1002/lary.20983DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2927501PMC
August 2010

Hypertonic challenge to porcine vocal folds: effects on epithelial barrier function.

Otolaryngol Head Neck Surg 2010 Jan 22;142(1):79-84. Epub 2009 Nov 22.

Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, IN, USA.

Objective: Dehydration challenges can increase the chemical composition of surface fluid overlying vocal fold epithelia (hypertonic surface fluid). The vocal fold epithelium is posited to act as a barrier, shielding the lamina propria from perturbations in the airway lumen. However, the effects of hypertonic surface fluid on the barrier functions of vocal fold epithelia have not been quantified. We, therefore, sought to investigate whether hypertonic surface fluid compromises epithelial barrier function. We examined the effects of hypertonic surface fluid on vocal fold epithelial resistance, paracellular pathway morphology, and tight junction protein integrity.

Study Design: Ex vivo, between group design.

Setting: Laboratory.

Methods: Porcine vocal folds (n = 24) were exposed to hypertonic or isotonic challenge and examined by electrophysiology, transmission electron microscopy, and Western blot analyses.

Results: Hypertonic, but not isotonic, challenge significantly reduced transepithelial resistance. This decrease in resistance was observed immediately after the challenge and was consistent with the appearance of dilated paracellular pathway morphology. However, hypertonic challenge did not alter protein levels of occludin, zona occludens-1, E-cadherin, or beta-catenin.

Conclusion: Hypertonic surface fluid alters epithelial barrier function in the vocal folds. Specifically, exposure to hypertonic challenges increases epithelial permeability. Given the important role of the vocal fold epithelium in shielding the underlying mucosa from inhaled pathogens and pollutants, our data provide the impetus for future studies on pharmacological treatments aimed at restoring the hydration level and chemical composition of vocal fold surface fluid.
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http://dx.doi.org/10.1016/j.otohns.2009.09.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2928222PMC
January 2010

Evidence for adverse phonatory change following an inhaled combination treatment.

J Speech Lang Hear Res 2010 Feb 20;53(1):75-83. Epub 2009 Aug 20.

Purdue University, West Lafayette, IN 47907, USA.

Purpose: Voice problems are reported as a frequent side effect of inhaled combination (IC) treatments. The purpose of this experimental study was to investigate whether IC treatments are detrimental to phonation. We hypothesized that IC treatment would significantly increase phonation threshold pressure (PTP) and perceived phonatory effort (PPE), whereas sham treatment would not.

Method: Fourteen healthy adults participated in a repeated-measures design in which they received IC and sham treatments in counterbalanced order. PTP and PPE were measured prior to treatments, immediately following treatments, and at 1 and 2 hr following treatments.

Results: IC treatment increased PTP, but sham treatment did not. The increase in PTP was maintained for a 2 hr period following administration. PPE ratings were not significantly correlated with PTP.

Conclusions: IC treatments can have acute, adverse effects on phonation. Detrimental phonatory effects were elicited in participants with no self-reported voice problems. IC treatments are being increasingly prescribed across the lifespan. The current data increase our understanding of the nature of phonatory deterioration associated with IC treatment and lay the groundwork for increased research effort to develop IC treatments that effectively control respiratory disease while minimizing an adverse effect on phonation.
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http://dx.doi.org/10.1044/1092-4388(2009/09-0024)DOI Listing
February 2010

Identifying putative promoter regions of Hermansky-Pudlak syndrome genes by means of phylogenetic footprinting.

Ann Hum Genet 2009 Jul;73(Pt 4):422-8

Section on Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.

HPS is an autosomal recessive disorder characterized by oculocutaneous albinism and prolonged bleeding. Eight human genes are described resulting in the HPS subtypes 1-8. Certain HPS proteins combine to form Biogenesis of Lysosome-related Organelles Complexes (BLOCs), thought to function in the formation of intracellular vesicles such as melanosomes, platelet dense bodies, and lytic granules. Specifically, BLOC-2 contains the HPS3, HPS5 and HPS6 proteins. We used phylogenetic footprinting to identify conserved regions in the upstream sequences of HPS3, HPS5 and HPS6. These conserved regions were verified to have in vitro transcription activation activity using luciferase reporter assays. Transcription factor binding site analyses of the regions identified 52 putative sites shared by all three genes. When analysis was limited to the conserved footprints, seven binding sites were found shared among all three genes: Pax-5, AIRE, CACD, ZF5, Zic1, E2F and Churchill. The HPS3 conserved upstream region was sequenced in four patients with decreased fibroblast HPS3 RNA levels and only one HPS3 mutation in the coding exons and surrounding exon/intron boundaries; no mutation was found. These findings illustrate the power of phylogenetic footprinting for identifying potential regulatory regions in non-coding sequences and define the first putative promoter elements for any HPS genes.
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http://dx.doi.org/10.1111/j.1469-1809.2009.00525.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2730976PMC
July 2009

Short-duration accelerated breathing challenges affect phonation.

Laryngoscope 2009 Aug;119(8):1658-63

Department of Speech, Language, and Hearing Sciences, Purdue University, West Lafayette, Indiana 47907, USA.

Objectives/hypothesis: Inhaled air must be adequately humidified to prevent vocal fold drying, which is detrimental to phonation. The water content of inspired air is reduced by parameters, such as increased breathing rate and oral route. Accelerated oral breathing challenges induce airway dehydration and are posited to affect airway function. The primary objective of this study was to investigate whether accelerated oral breathing challenges are detrimental to phonation. The secondary objective of this study was to determine whether individuals at increased risk for developing voice problems (i.e., smokers) have greater adverse phonatory effects after accelerated breathing challenge than nonsmoking controls.

Study Design: Prospective study with between-subjects, repeated-measures design.

Methods: Female smokers (n = 12) and nonsmoking controls (n = 12) participated in this experimental study over 2 days that differed in ambient humidity. Phonation threshold pressures (PTP) were collected prior to and following short-term accelerated and habitual breathing challenges. Respiratory measures were collected during the challenges.

Results: Short-term accelerated breathing challenges significantly increased PTP. This increase in PTP with accelerated breathing was transient and not significantly influenced by breathing route, ambient humidity, or smoking status. Likewise, respiratory measures were not affected by breathing route, ambient humidity, or smoking status.

Conclusions: During daily activities, such as exercise, individuals may engage in accelerated breathing for prolonged durations. This study demonstrates that even extremely short durations of accelerated breathing may affect phonation.
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http://dx.doi.org/10.1002/lary.20530DOI Listing
August 2009

Fuming method for micropatterning structures on Langmuir-Blodgett films.

Langmuir 2009 May;25(9):5098-102

Ralph N. Adams Institute for Bioanalytical Chemistry, Department of Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Drive, Lawrence, Kansas 66047, USA.

Lipid monolayers of L-alpha-dipalmitoylphosphatidylcholine (DPPC) are used to pattern substrates using the Langmuir-Blodgett (LB) technique. Lipid monolayers are deposited onto freshly cleaved mica surfaces or glass capillaries under conditions that lead to distinct patterns in the film. Exposure of the supported monolayer to ethyl 2-cyanoacrylate fumes leads to preferential polymerization in the more hydrated regions of the patterned monolayer. This method enables surfaces to be micropatterned where the lateral features are controlled by the structure present in the underlying LB film, and the vertical feature size is controlled by the length of the fuming process. Atomic force microscopy (AFM) measurements confirm that the original structure in the LB film is preserved following fuming and that the lateral and vertical feature sizes can be controlled from nanometers to micrometers. This method, therefore, provides a rapid and versatile approach for micropatterning both flat and curved surfaces on a variety of substrates.
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http://dx.doi.org/10.1021/la804104kDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3570059PMC
May 2009

Mitogen-activated protein kinases as therapeutic targets in osteoarthritis.

Curr Opin Rheumatol 2008 Sep;20(5):581-6

Department of Internal Medicine, Section of Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.

Purpose Of Review: The mitogen-activated protein (MAP) kinases are intracellular signaling proteins which play a central role in controlling the activity of pathways that regulate production and activity of multiple mediators of joint tissue destruction. The therapeutic potential of MAP kinase inhibition in osteoarthritis was reviewed.

Recent Findings: Results from basic research studies support the role of MAP kinases as central mediators that regulate expression of proinflammatory cytokines and metalloproteinases but also as potential pain mediators as well. Cell culture and animal model studies suggest that inhibition of MAP kinases might slow progression of osteoarthritis but trials of MAP kinase inhibitors in humans with osteoarthritis have not yet been reported. Safety concerns of the currently available inhibitors have limited their initial use to trials in conditions considered more severe than osteoarthritis.

Summary: MAP kinase inhibition has the potential to slow disease progression in osteoarthritis and also might reduce pain; however, safety concerns have limited the use of general MAP kinase inhibitors in humans. Further understanding of the function of specific isoforms of the MAP kinases as well as upstream and downstream effectors may lead to the development of more specific inhibitors with less toxicity that could eventually be used as structure-modifying drugs for osteoarthritis.
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http://dx.doi.org/10.1097/BOR.0b013e3283090463DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2892710PMC
September 2008

Phonatory effects of airway dehydration: preliminary evidence for impaired compensation to oral breathing in individuals with a history of vocal fatigue.

J Speech Lang Hear Res 2008 Dec 29;51(6):1494-506. Epub 2008 Jul 29.

Department of Speech, Language, and Hearing Sciences, 500 Oval Drive, Purdue University, West Lafayette, IN 47907, USA.

Purpose: Airway drying is detrimental to phonation and is posited to exacerbate vocal fatigue. However, limited research has demonstrated the adverse phonatory effects of dehydration in speakers reporting vocal fatigue. We compared the negative phonatory consequences of short-term oral breathing at low, moderate, and high humidity in individuals reporting a history of vocal fatigue and control participants.

Method: Females reporting a history of vocal fatigue (N = 8) and matched controls (N = 8) participated in a repeated-measures design over 3 different days.

Results: Oral breathing at low and moderate humidity increased phonation threshold pressure (PTP) to a greater extent in individuals reporting a history of vocal fatigue as compared to controls. Conversely, PTP did not increase in either participant group after oral breathing in a humid environment. Perceived phonatory effort (PPE) ratings were poorly correlated with PTP.

Conclusions: The emergence of between-group differences in PTP at low and moderate but not high ambient humidity demonstrates that drying challenges might be detrimental to voice production in individuals with a history of vocal fatigue. Based on the phonatory effects of dehydration, we suggest that individuals reporting vocal fatigue may demonstrate impaired compensation to airway drying induced by short-term oral breathing.
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http://dx.doi.org/10.1044/1092-4388(2008/07-0181)DOI Listing
December 2008

Characterization of power induced heating and damage in fiber optic probes for near-field scanning optical microscopy.

Rev Sci Instrum 2007 May;78(5):053712

Department of Chemistry, University of Kansas, Multidisciplinary Research Building, 2030 Becker Drive, Lawrence, KS 66047, USA.

Tip-induced sample heating in near-field scanning optical microscopy (NSOM) is studied for fiber optic probes fabricated using the chemical etching technique. To characterize sample heating from etched NSOM probes, the spectra of a thermochromic polymer sample are measured as a function of probe output power, as was previously reported for pulled NSOM probes. The results reveal that sample heating increases rapidly to approximately 55-60 degrees C as output powers reach approximately 50 nW. At higher output powers, the sample heating remains approximately constant up to the maximum power studied of approximately 450 nW. The sample heating profiles measured for etched NSOM probes are consistent with those previously measured for NSOM probes fabricated using the pulling method. At high powers, both pulled and etched NSOM probes fail as the aluminum coating is damaged. For probes fabricated in our laboratory we find failure occurring at input powers of 3.4+/-1.7 and 20.7+/-6.9 mW for pulled and etched probes, respectively. The larger half-cone angle for etched probes ( approximately 15 degrees for etched and approximately 6 degrees for pulled probes) enables more light delivery and also apparently leads to a different failure mechanism. For pulled NSOM probes, high resolution images of NSOM probes as power is increased reveal the development of stress fractures in the coating at a taper diameter of approximately 6 microm. These stress fractures, arising from the differential heating expansion of the dielectric and the metal coating, eventually lead to coating removal and probe failure. For etched tips, the absence of clear stress fractures and the pooled morphology of the damaged aluminum coating following failure suggest that thermal damage may cause coating failure, although other mechanisms cannot be ruled out.
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http://dx.doi.org/10.1063/1.2740133DOI Listing
May 2007

Endogenous production of reactive oxygen species is required for stimulation of human articular chondrocyte matrix metalloproteinase production by fibronectin fragments.

Free Radic Biol Med 2007 May 24;42(9):1350-8. Epub 2007 Jan 24.

Department of Biochemistry, Section of Rheumatology, Rush Medical College, Chicago, IL, USA.

The objective of the present study was to determine if reactive oxygen species (ROS) are required as secondary messengers for fibronectin fragment-stimulated matrix metalloproteinase (MMP) production in human articular chondrocytes. Cultured cells were stimulated with 25 microg/ml of the alpha5beta1 integrin-binding 110-kDa fibronectin fragment (FN-f) in the presence and absence of various antioxidants including Mn(III) tetrakis(4-benzoic acid)porphyrin (MnTBAP). FN-f stimulation significantly increased intracellular levels of ROS in articular chondrocytes. Pretreatment of cells with 250 microM MnTBAP or 40 mM N-acetyl-L-cysteine, but not inhibitors of nitric oxide synthase, completely prevented FN-f-stimulated MMP-3, -10, and -13 production. MnTBAP also blocked FN-f-induced phosphorylation of the MAP kinases and NF-kappaB-associated proteins and blocked activation of an NF-kappaB promoter-reporter construct. Overexpression of catalase, superoxide dismutase, or glutathione peroxidase also inhibited FN-f-stimulated MMP-13 production. Preincubation of chondrocytes with rotenone, an inhibitor of the mitochondrial electron transport chain, or nordihydroguaiaretic acid (NDGA), a selective 5-lipoxygenase inhibitor, partially prevented FN-f-stimulated MMP-13 production and decreased MAP kinase and NF-kappaB phosphorylation. These results show that increased production of ROS but not nitric oxide as obligatory secondary messengers in the chondrocyte FN-f signaling pathway leads to the increased production of MMPs, including MMP-13.
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http://dx.doi.org/10.1016/j.freeradbiomed.2007.01.035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892212PMC
May 2007

The role of nuclear envelope calcium in modifying nuclear pore complex structure.

Can J Physiol Pharmacol 2006 Mar-Apr;84(3-4):309-18

Department of Chemistry, University of Kansas, Lawrence, 66045, USA.

Some of the most important trafficking processes in cells involve transport across the nuclear envelope. Whether it is the import of transcription factors or the export of RNA, the only known portal across the double lipid bilayer that forms the nuclear envelope are the macromolecular pores known as nuclear pore complexes (NPCs). Understanding how signals influence the conformation of the NPC is important for testing models of, and perhaps modifying, transport across the nuclear envelope. Here we summarize high-resolution atomic force microscopy studies of NPC structure following manipulation of nuclear envelope calcium stores of nuclei from Xenopus laevis oocytes. The results show that the release of calcium from these stores through the specific activation of inositol 1,4,5-trisphosphate receptors leads to changes in NPC structure observable from both sides of the nuclear envelope. The diameter of the NPC is also sensitive to these calcium stores and increases upon calcium release. Western blot analysis reveals the presence of ryanodine receptors in the nuclear envelope of X. laevis oocytes, although in low abundance. Activation of these calcium channels also leads to the displacement of the central mass and changes in NPC diameter. This change in structure may involve a displacement of the cytoplasmic and nuclear rings of the NPC towards each other, leading to the apparent emergence of the central mass from both sides of the NPC. The changes in conformation and diameter of the NPC may alter cargo access and binding to phenylalanine-glycine repeats lining the pore, thus altering transport.
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http://dx.doi.org/10.1139/y05-109DOI Listing
September 2006

Nuclear side conformational changes in the nuclear pore complex following calcium release from the nuclear membrane.

Phys Biol 2004 Jun;1(1-2):125-34

Department of Chemistry, University of Kansas, Malott Hall, Lawrence, KS 66045, USA.

Changes in nuclear pore complex (NPC) structure are studied following treatments modifying the cisternal calcium levels located between the two lipid bilayers that together form the nuclear envelope. Since the NPC forms the only known passageway across the nuclear envelope, it plays a central role in nucleocytoplasmic transport. Understanding the origin of conformational changes that may affect this trafficking or modify cargo interactions with the NPC is, therefore, necessary to completely understand the function of these complex molecules. In previous studies on the cytoplasmic side of the nuclear envelope, a central mass was observed in the pore of the NPC and its location was shown to be sensitive to the cisternal calcium levels. Here we report atomic force microscopy (AFM) measurements on the nuclear side of the envelope, which also reveal a cisternal calcium dependence in the conformational state of the NPC. These measurements, made at the single nuclear pore level, reveal a displacement of the central mass towards the nuclear side of the membrane following treatments with adenophostin A, a specific agonist of calcium channels (inositol 1,4,5-trisphosphate (IP(3)) receptors) located in the nuclear envelope. We further demonstrate that these conformational changes are observed in nuclear pores lacking the basket structure while samples prepared in the presence of protease inhibitors retain baskets and block AFM measurements of the channel. While these measurements are unable to distinguish whether the central mass is cargo or an integral component of the NPC, its dose-dependent displacement with cisternal calcium levels does suggest links to transport or to changes in cargo interactions with the NPC. Taken together with previous measurements done on the cytoplasmic side of the nuclear envelope, these studies argue against a piston-like displacement of the central mass and instead suggest a more complicated mechanism. One possibility involves a concerted collapse of the NPC rings towards one another following cisternal calcium release, thus leading to the apparent emergence of the central mass from each side of the NPC.
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http://dx.doi.org/10.1088/1478-3967/1/2/008DOI Listing
June 2004

Activation of ryanodine receptors in the nuclear envelope alters the conformation of the nuclear pore complex.

Biophys Chem 2004 Dec;112(1):1-7

Department of Chemistry, University of Kansas, 1251 Wescoe Drive, Lawrence, KS 66045, USA.

Nuclear pore complexes (NPCs) are supramolecular protein pores that traverse the nuclear envelope and form the only known direct route of transport between the cytoplasmic and nuclear spaces. Detailed studies have identified both active and passive mechanisms of transport through the NPC and structural studies have revealed its three-dimensional architecture. Under certain conditions, structural studies have found evidence for a mass in the central pore of the NPC whose identity remains unclear. Some studies suggest this mass represents cargo caught in transit, while others suggest it is an integral component of the NPC, the position of which is sensitive to sample conditions. Regardless of its identity, previous studies have shown that the central mass location within the NPC pore is influenced by the presence of calcium in the cisternal spaces of the nuclear membrane. Specific depletion of these calcium stores through inositol 1,4,5-trisphosphate (IP(3)) receptor activation leads to the apparent displacement of the central mass towards both the cytoplasmic and nucleoplasmic sides of the NPC. Whether the central mass is cargo or a NPC component, these observations may offer interesting insights linking transport and calcium signaling pathways. Here, we show that ryanodine (Ry) receptors are also present in the nuclear envelope of Xenopus laevis oocytes, and their specific activation can affect the conformational state of the NPC. Although previously undetected, Western blot analysis of isolated oocyte nuclei reveals the presence of Ry receptors in the nuclear envelope, albeit in low abundance. Extensive atomic force microscopy (AFM) studies at the single pore level of isolated, fixed nuclei reveal changes in the NPC conformational state following treatments that stimulate Ry receptor activity. At resting calcium levels ( approximately 200 nM Ca(2+)), the central mass within the lumen of the NPC is recessed 5.3 nm below the cytoplasmic rim of the NPC. Following treatment with 10 nM ryanodine, the central mass displaces towards the cytoplasmic face occupying a new position only 2.9 nm below the cytoplasmic rim. Interestingly, at high ryanodine concentrations (20 microM), which are reported to deactivate Ry receptors, the central mass is observed to return to the recessed position, 5.4 nm below the cytoplasmic rim. Treatments with caffeine also lead to large changes in the NPC conformation, confirming the link to specific activation of Ry receptors. These observations are consistent with a new mechanism of NPC regulation in which specific activation of Ry receptors located in the nuclear envelope can modulate cisternal calcium levels, leading to changes in the NPC conformation. Together with previous studies, it now appears that both IP(3) and Ry receptors are present in the nuclear envelope of Xenopus oocytes and are capable, through activation, of indirectly influencing the conformational state of the NPC.
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http://dx.doi.org/10.1016/j.bpc.2004.06.010DOI Listing
December 2004

Effect of lipopolysaccharide on virulence of intestinal candida albicans.

J Surg Res 2003 Jul;113(1):42-9

Department of Laboratory Medicine & Pathology, Minneapolis, Minnesota 55455, USA.

Background: Candida albicans is a polymorphic fungus that frequently causes systemic infection in postsurgical and trauma patients. Others have reported that Escherichia coli lipopolysaccharide (LPS) acts as a copathogen to enhance the virulence of parenteral C. albicans. Experiments were designed to clarify the effect of parenteral LPS on systemic candidiasis initiated via the oral route.

Materials And Methods: Antibiotic-treated mice were orally inoculated with C. albicans CAF2 (wild-type) or mutant HLC54 (defective in filament formation), and were given 100 microg parenteral LPS 16 h before sacrifice. Separate groups of mice were additionally exposed to intermittent hypoxia prior to LPS. At sacrifice, cecal flora and microbial translocation to the mesenteric lymph nodes were quantified. C. albicans adherence to cultured HT-29 and Caco-2 enterocytes (pretreated with LPS, or calcium-free medium to expose the enterocyte lateral surface, or both) was quantified by enzyme-linked immunoabsorbent assay.

Results: All mice had high numbers of cecal C. albicans, and LPS was associated with an additional increase in cecal concentrations of HLC54 but not CAF2. Translocation of HLC54, but not CAF2, appeared facilitated by hypoxia, but LPS did not facilitate translocation in any treatment group. Exposure of the lateral surface of cultured enterocytes had no effect on C. albicans adherence, although LPS consistently decreased adherence of both C. albicans strains.

Conclusions: In contrast to experiments where systemic candidiasis was initiated by the parenteral route, parenteral LPS did not act as a copathogen in mice with systemic candidiasis initiated by the oral route, and these results might be related to LPS-induced alterations in C. albicans adherence to host enterocytes.
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http://dx.doi.org/10.1016/s0022-4804(03)00156-2DOI Listing
July 2003

The social consequences of expressive suppression.

Emotion 2003 Mar;3(1):48-67

Department of Psychology, Stanford University, California 94305-2130, USA.

At times, people keep their emotions from showing during social interactions. The authors' analysis suggests that such expressive suppression should disrupt communication and increase stress levels. To test this hypothesis, the authors conducted 2 studies in which unacquainted pairs of women discussed an upsetting topic. In Study 1, one member of each pair was randomly assigned to (a) suppress her emotional behavior, (b) respond naturally, or (c) cognitively reappraise in a way that reduced emotional responding. Suppression alone disrupted communication and magnified blood pressure responses in the suppressors' partners. In Study 2, suppression had a negative impact on the regulators' emotional experience and increased blood pressure in both regulators and their partners. Suppression also reduced rapport and inhibited relationship formation.
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http://dx.doi.org/10.1037/1528-3542.3.1.48DOI Listing
March 2003

Role of heparan sulfate in interactions of Listeria monocytogenes with enterocytes.

Med Microbiol Immunol 2003 May 5;192(2):107-15. Epub 2003 Mar 5.

Department of Laboratory Medicine and Pathology, University of Minnesota, Mayo Mail Code 609, 420 Delaware Street, SE, MN 55455, USA.

Heparan sulfate is known to participate in binding a wide variety of microbes to mammalian cells, but few studies have focused on the enterocyte. Normal human colonic and small intestinal enterocytes, and cultured HT-29 (but not Caco-2) enterocytes, reacted prominently with antibodies specific for heparan sulfate and for the core protein of syndecan-1 (a heparan sulfate proteoglycan). The heparan sulfate analog, heparin, inhibited interactions of Listeria monocytogenes (adherence and internalization) with HT-29, but not Caco-2, enterocytes. Internalization of L. monocytogenes by HT-29 enterocytes was inhibited by heparan sulfate and to a lesser extent by chondroitin sulfate, but not by the non-sulfated glycosaminoglycan hyaluronic acid. Compared to plasmid control ARH-77 cells, adherence of L. monocytogenes, was increased using ARH-77 cells transfected with syndecan-1 cDNA. Heparin binding protein(s) on L. monocytogenes were confirmed using biotinylated heparin. To determine if these in vitro observations might have in vivo relevance, L. monocytogenes was preincubated with heparin and then orally inoculated into mice. Compared to L. monocytogenes not pretreated with heparin, L. monocytogenes pretreated with heparin was associated with decreased extraintestinal dissemination to the mesenteric lymph nodes and liver of orally inoculated mice. Thus, heparan sulfate (possibly as the heparan sulfate proteoglycan syndecan-1) appears to participate in interactions of L. monocytogenes with enterocytes.
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http://dx.doi.org/10.1007/s00430-002-0165-7DOI Listing
May 2003

Determining critical flow conditions for chloride impairment in an effluent-dominated, storm-peaking, Western U.S. stream.

Water Environ Res 2003 Jan-Feb;75(1):39-53

Department of Environmental Science and Policy, University of South Florida, Tampa 33620, USA.

Extensive agricultural land use and intensive urban residential growth of the Calleguas Creek, California, watershed has increased chloride load and impaired beneficial uses. The hydrology of the watershed is typical of the semiarid U.S. West in that nearly all rainfall occurs in a small number of discrete storm events that each produces peak discharges of a duration of several days or less; conversely, during the dry weather season, discharge has historically been near zero. Currently, a year-round flow is sustained by two factors: base line flow sustained by discharges from publicly owned treatment works (POTWs) and increased groundwater discharge from a shallow water table elevated by intensive agricultural irrigation (deep groundwater basins used for water supply have declined into overdraft). Water quality impairment of Calleguas Creek increases during low-flow days, but cannot be defined seasonally because days not influenced by storm discharge occur at substantial proportions during all months. Impairment is greatest not during lowest flows, which are dominated by POTW effluent, but when groundwater and other nonpoint sources are highest, thereby contributing chloride load disproportionately to their flow. The highest nonstorm days are identified through cumulative frequency of mean daily discharge (MDD) as the transition from nonstorm conditions (described by normal distribution) to storm conditions (described by log-normal distribution). Transition occurs at approximately the 80th to 85th percentile MDD at three Calleguas Creek locations. Critical conditions for chloride impairment are defined as volumetric flow at those percentiles of cumulative MDD distribution.
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http://dx.doi.org/10.2175/106143003x140818DOI Listing
June 2003

Contracts to bear a child.

Calif Law Rev 1978 May;66(3):611-22

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May 1978