49 results on '"Saunders SE"'
Search Results
2. Mutually exclusive expression of alternatively spliced FMRFamide transcripts in identified neuronal systems of the snail Lymnaea
- Author
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Bright, K, primary, Kellett, E, additional, Saunders, SE, additional, Brierley, M, additional, Burke, JF, additional, and Benjamin, PR, additional
- Published
- 1993
- Full Text
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3. Cell-specific alternative RNA splicing of an FMRFamide gene transcript in the brain
- Author
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Saunders, SE, primary, Kellett, E, additional, Bright, K, additional, Benjamin, PR, additional, and Burke, JF, additional
- Published
- 1992
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4. Occurrence, transmission, and zoonotic potential of chronic wasting disease.
- Author
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Saunders SE, Bartelt-Hunt SL, Bartz JC, Saunders, Samuel E, Bartelt-Hunt, Shannon L, and Bartz, Jason C
- Abstract
Chronic wasting disease (CWD) is a fatal, transmissible prion disease that affects captive and free-ranging deer, elk, and moose. Although the zoonotic potential of CWD is considered low, identification of multiple CWD strains and the potential for agent evolution upon serial passage hinders a definitive conclusion. Surveillance for CWD in free-ranging populations has documented a continual geographic spread of the disease throughout North America. CWD prions are shed from clinically and preclinically affected hosts, and CWD transmission is mediated at least in part by the environment, perhaps by soil. Much remains unknown, including the sites and mechanisms of prion uptake in the naive host. There are no therapeutics or effective eradication measures for CWD-endemic populations. Continued surveillance and research of CWD and its effects on cervid ecosystems is vital for controlling the long-term consequences of this emerging disease. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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5. Neuropeptides Gly-Asp-Pro-Phe-Leu-Arg-Phe-amide (GDPFLRFamide) and Ser- Asp-Pro-Phe-Leu-Arg-Phe-amide (SDPFLRFamide) are encoded by an exon 3' to Phe-Met-Arg-Phe-NH2 (FMRFamide) in the snail Lymnaea stagnalis
- Author
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Saunders, SE, primary, Bright, K, additional, Kellett, E, additional, Benjamin, PR, additional, and Burke, JF, additional
- Published
- 1991
- Full Text
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6. Post-partum breast feeding support: impact on duration.
- Author
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Saunders SE and Carroll J
- Published
- 1988
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7. Insulin activates parasympathetic hepatic-related neurons of the paraventricular nucleus of the hypothalamus through mTOR signaling.
- Author
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Dos Santos KM, Saunders SE, Antunes VR, and Boychuk CR
- Abstract
Integration of autonomic and metabolic regulation, including hepatic function, is a critical role played by the brain's hypothalamic region. Specifically, the paraventricular nucleus of the hypothalamus (PVN) regulates autonomic functions related to metabolism, such as hepatic glucose production. Although insulin can act directly on hepatic tissue to inhibit hepatic glucose production, recent evidence implicates central actions of insulin within PVN also regulates glucose metabolism. However, specific central circuits responsible for insulin signaling with relation to hepatic regulation are poorly understood. As a heterogenous nucleus essential to controlling parasympathetic motor output with notable expression of insulin receptors, PVN is an appealing target for insulin-dependent modulation of parasympathetic activity. Here, we tested the hypothesis that insulin activates hepatic-related PVN (PVN
hepatic ) neurons through a parasympathetic pathway. Using transsynaptic retrograde tracing, labeling within PVN was first identified 24 h after its expression in DMV and 72 h after hepatic injection. Critically, nearly all labeling in medial PVN was abolished after a left vagotomy, indicating that PVNhepatic neurons in this region are part of a central circuit innervating parasympathetic motor neurons. Insulin also significantly increased firing frequency of PVNhepatic neurons in this subregion. Mechanistically, rapamycin pretreatment inhibited insulin-dependent activation of PVNhepatic neurons. Therefore, central insulin signaling can activate a subset of PVNhepatic neurons which are part of a unique parasympathetic network in control of hepatic function. Taken together, PVNhepatic neurons related to parasympathetic output regulation could serve as a key central network in insulin's ability to control hepatic functions.- Published
- 2024
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8. Hibernation reduces GABA signaling in the brainstem to enhance motor activity of breathing at cool temperatures.
- Author
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Saunders SE and Santin JM
- Subjects
- Animals, Rana catesbeiana physiology, Motor Activity physiology, gamma-Aminobutyric Acid metabolism, Signal Transduction physiology, Receptors, GABA-A metabolism, Receptors, GABA-A physiology, Motor Neurons physiology, Hibernation physiology, Brain Stem physiology, Cold Temperature, Respiration
- Abstract
Background: Neural circuits produce reliable activity patterns despite disturbances in the environment. For this to occur, neurons elicit synaptic plasticity during perturbations. However, recent work suggests that plasticity not only regulates circuit activity during disturbances, but these modifications may also linger to stabilize circuits during future perturbations. The implementation of such a regulation scheme for real-life environmental challenges of animals remains unclear. Amphibians provide insight into this problem in a rather extreme way, as circuits that generate breathing are inactive for several months during underwater hibernation and use compensatory plasticity to promote ventilation upon emergence., Results: Using ex vivo brainstem preparations and electrophysiology, we find that hibernation in American bullfrogs reduces GABA
A receptor (GABAA R) inhibition in respiratory rhythm generating circuits and motor neurons, consistent with a compensatory response to chronic inactivity. Although GABAA Rs are normally critical for breathing, baseline network output at warm temperatures was not affected. However, when assessed across a range of temperatures, hibernators with reduced GABAA R signaling had greater activity at cooler temperatures, enhancing respiratory motor output under conditions that otherwise strongly depress breathing., Conclusions: Hibernation reduces GABAA R signaling to promote robust respiratory output only at cooler temperatures. Although frogs do not ventilate lungs during underwater hibernation, we suggest this would be beneficial for stabilizing breathing when the animal passes through a large temperature range during emergence in the spring. More broadly, these results demonstrate that compensatory synaptic plasticity can increase the operating range of circuits in harsh environments, thereby promoting adaptive behavior in conditions that suppress activity., (© 2024. The Author(s).)- Published
- 2024
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9. Activation of respiratory-related bursting in an isolated medullary section from adult bullfrogs.
- Author
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Saunders SE and Santin JM
- Subjects
- Animals, Rana catesbeiana, Respiration, Anura, Brain Stem, Norepinephrine
- Abstract
Breathing is generated by a rhythmic neural circuit in the brainstem, which contains conserved elements across vertebrate groups. In adult frogs, the 'lung area' located in the reticularis parvocellularis is thought to represent the core rhythm generator for breathing. Although this region is necessary for breathing-related motor output, whether it functions as an endogenous oscillator when isolated from other brainstem centers is not clear. Therefore, we generated thick brainstem sections that encompass the lung area to determine whether it can generate breathing-related motor output in a highly reduced preparation. Brainstem sections did not produce activity. However, subsaturating block of glycine receptors reliably led to the emergence of rhythmic motor output that was further enhanced by blockade of GABAA receptors. Output occurred in singlets and multi-burst episodes resembling the intact network. However, burst frequency was slower and individual bursts had longer durations than those produced by the intact preparation. In addition, burst frequency was reduced by noradrenaline and μ-opioids, and increased by serotonin, as observed in the intact network and in vivo. These results suggest that the lung area can be activated to produce rhythmic respiratory-related motor output in a reduced brainstem section and provide new insights into respiratory rhythm generation in adult amphibians. First, clustering breaths into episodes can occur within the rhythm-generating network without long-range input from structures such as the pons. Second, local inhibition near, or within, the rhythmogenic center may need to be overridden to express the respiratory rhythm., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)
- Published
- 2023
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10. Understanding and countering opioid-induced respiratory depression.
- Author
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Bateman JT, Saunders SE, and Levitt ES
- Subjects
- Humans, Analgesics, Opioid adverse effects, Naloxone pharmacology, Respiration, Opiate Overdose drug therapy, Respiratory Insufficiency chemically induced, Respiratory Insufficiency drug therapy
- Abstract
Respiratory depression is the proximal cause of death in opioid overdose, yet the mechanisms underlying this potentially fatal outcome are not well understood. The goal of this review is to provide a comprehensive understanding of the pharmacological mechanisms of opioid-induced respiratory depression, which could lead to improved therapeutic options to counter opioid overdose, as well as other detrimental effects of opioids on breathing. The development of tolerance in the respiratory system is also discussed, as are differences in the degree of respiratory depression caused by various opioid agonists. Finally, potential future therapeutic agents aimed at reversing or avoiding opioid-induced respiratory depression through non-opioid receptor targets are in development and could provide certain advantages over naloxone. By providing an overview of mechanisms and effects of opioids in the respiratory network, this review will benefit future research on countering opioid-induced respiratory depression. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc., (© 2021 The British Pharmacological Society.)
- Published
- 2023
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11. Neuron populations use variable combinations of short-term feedback mechanisms to stabilize firing rate.
- Author
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Pellizzari S, Hu M, Amaral-Silva L, Saunders SE, and Santin JM
- Subjects
- Feedback, Action Potentials physiology, Motor Neurons physiology
- Abstract
Neurons tightly regulate firing rate and a failure to do so leads to multiple neurological disorders. Therefore, a fundamental question in neuroscience is how neurons produce reliable activity patterns for decades to generate behavior. Neurons have built-in feedback mechanisms that allow them to monitor their output and rapidly stabilize firing rate. Most work emphasizes the role of a dominant feedback system within a neuronal population for the control of moment-to-moment firing. In contrast, we find that respiratory motoneurons use 2 activity-dependent controllers in unique combinations across cells, dynamic activation of an Na+ pump subtype, and rapid potentiation of Kv7 channels. Both systems constrain firing rate by reducing excitability for up to a minute after a burst of action potentials but are recruited by different cellular signals associated with activity, increased intracellular Na+ (the Na+ pump), and membrane depolarization (Kv7 channels). Individual neurons do not simply contain equal amounts of each system. Rather, neurons under strong control of the Na+ pump are weakly regulated by Kv7 enhancement and vice versa along a continuum. Thus, each motoneuron maintains its characteristic firing rate through a unique combination of the Na+ pump and Kv7 channels, which are dynamically regulated by distinct feedback signals. These results reveal a new organizing strategy for stable circuit output involving multiple fast activity sensors scaled inversely across a neuronal population., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Pellizzari et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
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12. Fentanyl effects on respiratory neuron activity in the dorsolateral pons.
- Author
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Saunders SE, Baekey DM, and Levitt ES
- Subjects
- Rats, Animals, Fentanyl pharmacology, Pons physiology, Neurons physiology, Respiration, Naloxone pharmacology, Analgesics, Opioid pharmacology, Apnea
- Abstract
Opioids suppress breathing through actions in the brainstem, including respiratory-related areas of the dorsolateral pons, which contain multiple phenotypes of respiratory patterned neurons. The discharge identity of dorsolateral pontine neurons that are impacted by opioids is unknown. To address this, single neuronal units were recorded in the dorsolateral pons of arterially perfused in situ rat preparations that were perfused with an apneic concentration of the opioid agonist fentanyl, followed by the opioid antagonist naloxone (NLX). Dorsolateral pontine neurons were categorized based on respiratory-associated discharge patterns, which were differentially affected by fentanyl. Inspiratory neurons and a subset of inspiratory/expiratory phase-spanning neurons were either silenced or had reduced firing frequency during fentanyl-induced apnea, which was reversed upon administration of naloxone. In contrast, the majority of expiratory neurons continued to fire tonically during fentanyl-induced apnea, albeit with reduced firing frequency. In addition, pontine late-inspiratory and postinspiratory neuronal activity were absent from apneustic-like breaths during the transition to fentanyl-induced apnea and the naloxone-mediated transition to recovery. Thus, opioid-induced deficits in respiratory patterning may occur due to reduced activity of pontine inspiratory neurons, whereas apnea occurs with loss of all phasic pontine activity and sustained tonic expiratory neuron activity. NEW & NOTEWORTHY Opioids can suppress breathing via actions throughout the brainstem, including the dorsolateral pons. The respiratory phenotype of dorsolateral pontine neurons inhibited by opioids is unknown. Here, we describe the effect of the highly potent opioid fentanyl on the firing activity of these dorsolateral pontine neurons. Inspiratory neurons were largely silenced by fentanyl, whereas expiratory neurons were not. We provide a framework whereby this differential sensitivity to fentanyl can contribute to respiratory pattern deficits and apnea.
- Published
- 2022
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13. RAS-inhibiting biologics identify and probe druggable pockets including an SII-α3 allosteric site.
- Author
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Haza KZ, Martin HL, Rao A, Turner AL, Saunders SE, Petersen B, Tiede C, Tipping K, Tang AA, Ajayi M, Taylor T, Harvey M, Fishwick KM, Adams TL, Gaule TG, Trinh CH, Johnson M, Breeze AL, Edwards TA, McPherson MJ, and Tomlinson DC
- Subjects
- Allosteric Site, Biological Products chemistry, Humans, Neoplasms chemistry, Neoplasms enzymology, Signal Transduction, ras Proteins metabolism, Biological Products pharmacology, Cell Surface Display Techniques methods, Drug Discovery methods, Neoplasms drug therapy, ras Proteins antagonists & inhibitors
- Abstract
RAS mutations are the most common oncogenic drivers across human cancers, but there remains a paucity of clinically-validated pharmacological inhibitors of RAS, as druggable pockets have proven difficult to identify. Here, we identify two RAS-binding Affimer proteins, K3 and K6, that inhibit nucleotide exchange and downstream signaling pathways with distinct isoform and mutant profiles. Affimer K6 binds in the SI/SII pocket, whilst Affimer K3 is a non-covalent inhibitor of the SII region that reveals a conformer of wild-type RAS with a large, druggable SII/α3 pocket. Competitive NanoBRET between the RAS-binding Affimers and known RAS binding small-molecules demonstrates the potential to use Affimers as tools to identify pharmacophores. This work highlights the potential of using biologics with small interface surfaces to select unseen, druggable conformations in conjunction with pharmacophore identification for hard-to-drug proteins.
- Published
- 2021
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14. Kölliker-Fuse/Parabrachial complex mu opioid receptors contribute to fentanyl-induced apnea and respiratory rate depression.
- Author
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Saunders SE and Levitt ES
- Subjects
- Animals, Female, Male, Rats, Rats, Sprague-Dawley, Analgesics, Opioid pharmacology, Apnea chemically induced, Apnea prevention & control, Fentanyl pharmacology, Kolliker-Fuse Nucleus drug effects, Narcotic Antagonists pharmacology, Parabrachial Nucleus drug effects, Receptors, Opioid, mu drug effects, Respiratory Rate drug effects
- Abstract
Overdoses caused by the opioid agonist fentanyl have increased exponentially in recent years. Identifying mechanisms to counter progression to fatal respiratory apnea during opioid overdose is desirable, but difficult to study in vivo. The pontine Kölliker-Fuse/Parabrachial complex (KF/PB) provides respiratory drive and contains opioid-sensitive neurons. The contribution of the KF/PB complex to fentanyl-induced apnea was investigated using the in situ arterially perfused preparation of rat. Systemic application of fentanyl resulted in concentration-dependent respiratory disturbances. At low concentrations, respiratory rate slowed and subsequently transitioned to an apneustic-like, 2-phase pattern. Higher concentrations caused prolonged apnea, interrupted by occasional apneustic-like bursts. Application of CTAP, a selective mu opioid receptor antagonist, directly into the KF/PB complex reversed and prevented fentanyl-induced apnea by increasing the frequency of apneustic-like bursting. These results demonstrate that countering opioid effects in the KF/PB complex is sufficient to restore phasic respiratory output at a rate similar to pre-fentanyl conditions, which could be beneficial in opioid overdose., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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15. The effectiveness of antibiotic prophylaxis in preventing infective endocarditis is not easily dismissed.
- Author
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Lockhart PB, Bahrani Mougeot FK, Saunders SE, and Brennan MT
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- Female, Humans, Male, Antibiotic Prophylaxis, Bacteremia microbiology, Bacteremia prevention & control, Endocarditis, Bacterial microbiology, Endocarditis, Bacterial prevention & control, Prosthesis-Related Infections microbiology, Prosthesis-Related Infections prevention & control, Tooth Extraction adverse effects, Toothbrushing adverse effects
- Published
- 2015
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16. Associations between bacteremia from oral sources and distant-site infections: tooth brushing versus single tooth extraction.
- Author
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Mougeot FK, Saunders SE, Brennan MT, and Lockhart PB
- Subjects
- Adult, Bacteremia epidemiology, Endocarditis, Bacterial epidemiology, Female, Humans, Incidence, Male, Prosthesis-Related Infections epidemiology, Antibiotic Prophylaxis, Bacteremia microbiology, Bacteremia prevention & control, Endocarditis, Bacterial microbiology, Endocarditis, Bacterial prevention & control, Prosthesis-Related Infections microbiology, Prosthesis-Related Infections prevention & control, Tooth Extraction adverse effects, Toothbrushing adverse effects
- Abstract
Objectives: To determine the impact of antibiotic prophylaxis (AP) on the incidence of bacteremia caused by oral bacterial species associated with infective endocarditis (IE) and prosthetic joint infections (PJIs) and to compare the incidence of following tooth brushing versus single tooth extraction., Study Design: Bacterial species in blood following single tooth extraction, with or without AP, and tooth brushing(1) were compared with IE- and PJI-associated bacteria reported in the literature., Results: Of the 98 bacterial species identified in blood following single tooth extraction and tooth brushing, 32(1) and 12 were species were associated with IE and PJI, respectively. AP decreased the frequency of IE- and PJI-causing oral bacterial species in blood; however, single tooth extraction versus brushing resulted in bacteremia with IE- and PJI-causing species with similar frequencies: 65% versus 56% for IE, and 31% versus 28% for PJI., Conclusions: Although AP significantly decreased the incidence of bacteremia, the similarity between the incidence of bacteremia following brushing and extraction undermines AP as an effective strategy for the prevention of these distant-site infections., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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17. Protein misfolding cyclic amplification of prions.
- Author
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Saunders SE, Bartz JC, and Shikiya RA
- Subjects
- Animals, Cricetinae, PrPC Proteins genetics, PrPC Proteins metabolism, PrPSc Proteins genetics, PrPSc Proteins metabolism, Prion Diseases genetics, Prion Diseases metabolism, Protein Engineering methods, Protein Folding, PrPC Proteins chemistry, PrPSc Proteins chemistry
- Abstract
Prions are infectious agents that cause the inevitably fatal transmissible spongiform encephalopathy (TSE) in animals and humans(9,18). The prion protein has two distinct isoforms, the non-infectious host-encoded protein (PrP(C)) and the infectious protein (PrP(Sc)), an abnormally-folded isoform of PrP(C 8). One of the challenges of working with prion agents is the long incubation period prior to the development of clinical signs following host inoculation(13). This traditionally mandated long and expensive animal bioassay studies. Furthermore, the biochemical and biophysical properties of PrP(Sc) are poorly characterized due to their unusual conformation and aggregation states. PrP(Sc) can seed the conversion of PrP(C) to PrP(Sc) in vitro(14). PMCA is an in vitro technique that takes advantage of this ability using sonication and incubation cycles to produce large amounts of PrP(Sc), at an accelerated rate, from a system containing excess amounts of PrP(C) and minute amounts of the PrP(Sc) seed(19). This technique has proven to effectively recapitulate the species and strain specificity of PrP(Sc) conversion from PrP(C), to emulate prion strain interference, and to amplify very low levels of PrP(Sc) from infected tissues, fluids, and environmental samples(6,7,16,23) . This paper details the PMCA protocol, including recommendations for minimizing contamination, generating consistent results, and quantifying those results. We also discuss several PMCA applications, including generation and characterization of infectious prion strains, prion strain interference, and the detection of prions in the environment.
- Published
- 2012
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18. Methane and carbon dioxide production from simulated anaerobic degradation of cattle carcasses.
- Author
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Yuan Q, Saunders SE, and Bartelt-Hunt SL
- Subjects
- Anaerobiosis, Animals, Biodegradation, Environmental, Cadaver, Carbon Dioxide analysis, Environment, Methane analysis, Mortuary Practice, United States, Waste Products, Air Pollutants analysis, Carbon Dioxide metabolism, Cattle, Methane metabolism, Refuse Disposal methods
- Abstract
Approximately 2.2million cattle carcasses require disposal annually in the United States. Land burial is a convenient disposal method that has been widely used in animal production for disposal of both daily mortalities as well as during catastrophic mortality events. To date, greenhouse gas production after mortality burial has not been quantified, and this study represents the first attempt to quantify greenhouse gas emissions from land burial of animal carcasses. In this study, anaerobic decomposition of both homogenized and unhomogenized cattle carcass material was investigated using bench-scale reactors. Maximum yields of methane and carbon dioxide were 0.33 and 0.09m(3)/kg dry material, respectively, a higher methane yield than that previously reported for municipal solid waste. Variability in methane production rates were observed over time and between reactors. Based on our laboratory data, annual methane emissions from burial of cattle mortalities in the United States could total 1.6Tg CO(2) equivalents. Although this represents less than 1% of total emissions produced by the agricultural sector in 2009, greenhouse gas emissions from animal carcass burial may be significant if disposal of swine and poultry carcasses is also considered., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
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19. Soil-mediated prion transmission: is local soil-type a key determinant of prion disease incidence?
- Author
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Saunders SE, Bartz JC, and Bartelt-Hunt SL
- Subjects
- Animals, Humans, Prion Diseases transmission, Prion Diseases veterinary, Prion Diseases epidemiology, Prions analysis, Soil chemistry, Soil Pollutants analysis
- Abstract
Prion diseases, including chronic wasting disease (CWD) and scrapie, can be transmitted via indirect environmental routes. Animals habitually ingest soil, and results from laboratory experiments demonstrate prions can bind to a wide range of soils and soil minerals, retain the ability to replicate, and remain infectious, indicating soil could serve as a reservoir for natural prion transmission and a potential prion exposure route for humans. Preliminary epidemiological modeling suggests soil texture may influence the incidence of prion disease. These results are supported by experimental work demonstrating variance in prion interactions with soil, including variance in prion soil adsorption and soil-bound prion replication with respect to soil type. Thus, local soil type may be a key determinant of prion incidence. Further experimental and epidemiological work is required to fully elucidate the dynamics of soil-mediated prion transmission, an effort that should lead to effective disease management and mitigation strategies., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
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20. Resistance of soil-bound prions to rumen digestion.
- Author
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Saunders SE, Bartelt-Hunt SL, and Bartz JC
- Subjects
- Animals, Cricetinae, Male, PrPC Proteins pathogenicity, Prion Diseases transmission, Soil, Digestion physiology, PrPC Proteins metabolism, Prion Diseases metabolism, Rumen metabolism
- Abstract
Before prion uptake and infection can occur in the lower gastrointestinal system, ingested prions are subjected to anaerobic digestion in the rumen of cervids and bovids. The susceptibility of soil-bound prions to rumen digestion has not been evaluated previously. In this study, prions from infectious brain homogenates as well as prions bound to a range of soils and soil minerals were subjected to in vitro rumen digestion, and changes in PrP levels were measured via western blot. Binding to clay appeared to protect noninfectious hamster PrP(c) from complete digestion, while both unbound and soil-bound infectious PrP(Sc) proved highly resistant to rumen digestion. In addition, no change in intracerebral incubation period was observed following active rumen digestion of unbound hamster HY TME prions and HY TME prions bound to a silty clay loam soil. These results demonstrate that both unbound and soil-bound prions readily survive rumen digestion without a reduction in infectivity, further supporting the potential for soil-mediated transmission of chronic wasting disease (CWD) and scrapie in the environment.
- Published
- 2012
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21. An enzymatic treatment of soil-bound prions effectively inhibits replication.
- Author
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Saunders SE, Bartz JC, Vercauteren KC, and Bartelt-Hunt SL
- Subjects
- Hydrogen-Ion Concentration, Temperature, Disinfection methods, Prions metabolism, Soil chemistry, Subtilisin metabolism
- Abstract
Chronic wasting disease (CWD) and scrapie can be transmitted through indirect environmental routes, possibly via soil, and a practical decontamination strategy for prion-contaminated soil is currently unavailable. In the laboratory, an enzymatic treatment under environmentally relevant conditions (22°C, pH 7.4) can degrade soil-bound PrPSc below the limits of Western blot detection. We developed and used a quantitative serial protein misfolding cyclic amplification (PMCA) protocol to characterize the amplification efficiency of treated soil samples relative to controls of known infectious titer. Our results suggest large (10(4)- to >10(6)-fold) decreases in soil-bound prion infectivity following enzyme treatment, demonstrating that a mild enzymatic treatment could effectively reduce the risk of prion disease transmission via soil or other environmental surfaces.
- Published
- 2011
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22. Replication efficiency of soil-bound prions varies with soil type.
- Author
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Saunders SE, Shikiya RA, Langenfeld K, Bartelt-Hunt SL, and Bartz JC
- Subjects
- Adsorption, Animals, Cricetinae, Mink, Protein Binding, Protein Folding, Ruminants, Prions metabolism, Soil chemistry
- Abstract
Prion sorption to soil is thought to play an important role in the transmission of scrapie and chronic wasting disease (CWD) via the environment. Sorption of PrP to soil and soil minerals is influenced by the strain and species of PrP(Sc) and by soil characteristics. However, the ability of soil-bound prions to convert PrP(c) to PrP(Sc) under these wide-ranging conditions remains poorly understood. We developed a semiquantitative protein misfolding cyclic amplification (PMCA) protocol to evaluate replication efficiency of soil-bound prions. Binding of the hyper (HY) strain of transmissible mink encephalopathy (TME) (hamster) prions to a silty clay loam soil yielded a greater-than-1-log decrease in PMCA replication efficiency with a corresponding 1.3-log reduction in titer. The increased binding of PrP(Sc) to soil over time corresponded with a decrease in PMCA replication efficiency. The PMCA efficiency of bound prions varied with soil type, where prions bound to clay and organic surfaces exhibited significantly lower replication efficiencies while prions bound to sand exhibited no apparent difference in replication efficiency compared to unbound controls. PMCA results from hamster and CWD agent-infected elk prions yielded similar findings. Given that PrP(Sc) adsorption affinity varies with soil type, the overall balance between prion adsorption affinity and replication efficiency for the dominant soil types of an area may be a significant determinant in the environmental transmission of prion diseases.
- Published
- 2011
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23. Effects of solution chemistry and aging time on prion protein adsorption and replication of soil-bound prions.
- Author
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Saunders SE, Yuan Q, Bartz JC, and Bartelt-Hunt S
- Subjects
- Adsorption, Aluminum Silicates metabolism, Animals, Clay, Cricetinae, Minerals metabolism, Protein Binding, Silicon Dioxide metabolism, Solutions, Time Factors, PrPSc Proteins metabolism, Soil chemistry
- Abstract
Prion interactions with soil may play an important role in the transmission of chronic wasting disease (CWD) and scrapie. Prions are known to bind to a wide range of soil surfaces, but the effects of adsorption solution chemistry and long-term soil binding on prion fate and transmission risk are unknown. We investigated HY TME prion protein (PrP(Sc)) adsorption to soil minerals in aqueous solutions of phosphate buffered saline (PBS), sodium chloride, calcium chloride, and deionized water using western blotting. The replication efficiency of bound prions following adsorption in these solutions was also evaluated by protein misfolding cyclic amplification (PMCA). Aging studies investigated PrP(Sc) desorption and replication efficiency up to one year following adsorption in PBS or DI water. Results indicate that adsorption solution chemistry can affect subsequent prion replication or desorption ability, especially after incubation periods of 30 d or longer. Observed effects were minor over the short-term (7 d or less). Results of long-term aging experiments demonstrate that unbound prions or prions bound to a diverse range of soil surfaces can readily replicate after one year. Our results suggest that while prion-soil interactions can vary with solution chemistry, prions bound to soil could remain a risk for transmitting prion diseases after months in the environment.
- Published
- 2011
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24. Enzymatic digestion of chronic wasting disease prions bound to soil.
- Author
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Saunders SE, Bartz JC, Vercauteren KC, and Bartelt-Hunt SL
- Subjects
- Adsorption, Animals, Cricetinae, Prions, Scrapie metabolism, Soil, Wasting Disease, Chronic metabolism
- Abstract
Chronic wasting disease (CWD) and sheep scrapie can be transmitted via indirect environmental routes, and it is known that soil can serve as a reservoir of prion infectivity. Given the strong interaction between the prion protein (PrP) and soil, we hypothesized that binding to soil enhances prion resistance to enzymatic digestion, thereby facilitating prion longevity in the environment and providing protection from host degradation. We characterized the performance of a commercially available subtilisin enzyme, Prionzyme, to degrade soil-bound and unbound CWD and HY TME PrP as a function of pH, temperature, and treatment time. The subtilisin enzyme effectively degraded PrP adsorbed to a wide range of soils and soil minerals below the limits of detection. Signal loss occurred rapidly at high pH (12.5) and within 7 days under conditions representative of the natural environment (pH 7.4, 22 degrees C). We observed no apparent difference in enzyme effectiveness between bound and unbound CWD PrP. Our results show that although adsorbed prions do retain relative resistance to enzymatic digestion compared with other brain homogenate proteins, they can be effectively degraded when bound to soil. Our results also suggest a topical application of a subtilisin enzyme solution may be an effective decontamination method to limit disease transmission via environmental "hot spots" of prion infectivity.
- Published
- 2010
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25. Ethidium monoazide does not inhibit RT-PCR amplification of nonviable avian influenza RNA.
- Author
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Graiver DA, Saunders SE, Topliff CL, Kelling CL, and Bartelt-Hunt SL
- Subjects
- Animals, Birds, Influenza A virus genetics, Influenza in Birds virology, Virology methods, Antiviral Agents pharmacology, Azides pharmacology, Enzyme Inhibitors pharmacology, Influenza A virus physiology, Microbial Viability drug effects, RNA, Viral genetics, Reverse Transcriptase Polymerase Chain Reaction methods
- Abstract
A critical obstacle to using PCR to quantify viral titers is the distinguishment of viable and nonviable genomic material. Pretreatments of ethidium monoazide (EMA) have been effective in preventing PCR amplification of DNA from nonviable bacteria. To test whether an EMA pretreatment could be used with RT-PCR to quantify viable RNA virions, avian influenza virus (AIV) survival was measured in water through 28d using cell culture titration and real-time RT-PCR with or without EMA pretreatment. Cell culture titration yielded significantly lower titers than both RT-PCR procedures, and there was no significant difference between RT-PCR results with or without EMA. Ineffective binding of EMA to AIV RNA may have allowed nonviable AIV RNA to amplify. Furthermore, since AIV inactivation may take place by means other than membrane disruption, any pretreatment distinguishing viable and nonviable AIV virions by membrane integrity may not be practical., (Copyright (c) 2009 Elsevier B.V. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
26. Blunt testicular trauma results in rupture of mixed germ cell tumor.
- Author
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Luchey A, Rogers A, Saunders SE, Williams HJ, Fooks HJ, and Zaslau S
- Subjects
- Diagnosis, Differential, Hemorrhage diagnosis, Hemorrhage surgery, Humans, Male, Orchiectomy, Rupture, Spontaneous, Seminoma diagnosis, Seminoma surgery, Testicular Neoplasms diagnosis, Testicular Neoplasms surgery, Wounds, Nonpenetrating diagnosis, Young Adult, Hemorrhage etiology, Seminoma complications, Testicular Neoplasms complications, Testis injuries, Wounds, Nonpenetrating complications
- Abstract
It is extremely rare that a documented case of blunt trauma results in rupture of a testicular tumor. We present the case of a 24-year-old man who was crushed by a tree who developed spontaneous testicular rupture. At surgical exploration, he was found to ultimately have a mixed germ cell tumor of the testicle. This case illustrates the importance of physical examination, patient clinical history, and scrotal ultrasound in the management of scrotal trauma. In this instance, the testicular mass ruptured and lead to significant testicular hemorrhage.
- Published
- 2009
27. Prion protein adsorption to soil in a competitive matrix is slow and reduced.
- Author
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Saunders SE, Bartz JC, and Bartelt-Hunt SL
- Subjects
- Adsorption, Animals, Time Factors, Prion Diseases transmission, Prions chemistry, Soil analysis
- Abstract
It is likely that the soil environment serves as a stable reservoir of infectious CWD and scrapie prions as well as a potential reservoir of BSE. Prion adsorption to soil could play an important role in prion mobility, proteolysis, and infectivity. We modified previously published methods to quantify adsorbed prions via direct detection and studied prion adsorption to soil and soil minerals as a function of time through 60 days. Prion-infected brain homogenate was used as a complex, relevant prion source. We determined that maximum PrP adsorption requires days or weeks, depending on the soil or mineral, and is 2-5 orders of magnitude lower than previous studies using purified PrP(Sc) or recPrP. Because PrP adsorption to soil is slow and reduced in tissue homogenate, the possibility of prion transport in soil environments cannot be excluded and requires further investigation. Our results indicate that binding to soil may protect prions from degradation, consistent with prions' longevity in the environment. Adsorption of PrP to sterilized soil did not differ significantly from adsorption to unsterilized soil, which suggests that active biological processes do not significantly affect prion adsorption or degradation in the soil environment.
- Published
- 2009
- Full Text
- View/download PDF
28. Leiomyoma of the urinary bladder presenting as urinary retention in the female.
- Author
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Saunders SE, Conjeski JM, Zaslau S, Williams J, and Kandzari SJ
- Subjects
- Female, Humans, Leiomyoma diagnosis, Middle Aged, Urinary Bladder Neoplasms diagnosis, Leiomyoma complications, Urinary Bladder Neoplasms complications, Urinary Retention etiology
- Abstract
A case of leiomyoma of the urinary bladder, a rare benign tumor, in a 56-year-old female first seen with bilateral flank pain radiating to both groins, is reported. Examination showed a well developed female with obesity (260 pounds) and elevated blood pressure (132/90 mmHg). Evaluation with ultrasound, cystoscopy, urodynamics, and cytology contributed to the diagnosis of urinary bladder leiomyoma. Ultrasound detected a mass in the urinary bladder, and it was confirmed by cystoscopy to be a 5 cm to 6 cm bladder mass on the anterior bladder wall. The mass was prolapsing as a ball valve into the urethra at the level of the bladder neck. Frozen section of the mass showed it to be leiomyoma.
- Published
- 2009
29. Influence of prion strain on prion protein adsorption to soil in a competitive matrix.
- Author
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Saunders SE, Bartz JC, and Bartelt-Hunt SL
- Subjects
- Animals, Brain Chemistry, Humans, Prion Diseases transmission, Prion Diseases veterinary, Prions genetics, Protein Isoforms genetics, Prions chemistry, Protein Isoforms chemistry, Soil analysis
- Abstract
It is likely that the soil environment serves as a stable reservoir of infectious chronic wasting disease (CWD) and scrapie prions, as well as a potential reservoir of bovine spongiform encephalopathy (BSE, or "mad cow" disease). Prion adsorption to soil may play an important role in prion mobility, proteolysis, and infectivity. Differences in PrP environmental fate are possible due to the strain- and species-dependent structure of PrP(Sc). Kinetic and isothermal studies of PrP adsorption to sand and two whole soils were conducted using HY and DY TME-infected hamster, uninfected hamster, and CWD-infected elk brain homogenates as competitive PrP sources. The role of the N-terminus in PrP adsorption was also investigated. We report strain and species differences in PrP adsorption to soil over time and as a function of aqueous concentration, indicating that the fate of prions in the environment may vary with the prion strain and species infected. Our data also provide evidence that the N-terminal region of PrP enhances adsorption to clay but may hinder adsorption to sand. PrP adsorption was maximal at an intermediate aqueous concentration, most likely due to the competitive brain homogenate matrix in which it enters the soil environment.
- Published
- 2009
- Full Text
- View/download PDF
30. Penile prosthesis pump tubing erosion into urethra appearing as inability to catheterize: a case report.
- Author
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Brown ET, Saunders SE, and Zaslau S
- Subjects
- Cystoscopy, Device Removal, Diagnosis, Differential, Femoral Artery surgery, Humans, Ischemia surgery, Leg blood supply, Male, Middle Aged, Popliteal Artery surgery, Postoperative Complications surgery, Prosthesis Design, Reoperation methods, Penile Prosthesis adverse effects, Postoperative Complications diagnosis, Prosthesis Failure, Urethra injuries, Urinary Catheterization
- Abstract
Introduction: Erosion of penile prosthesis tubing represents a late complication of penile prosthesis surgery. To our knowledge, this is the first report of isolated erosion of penile implant pump tubing into the urethra in an otherwise asymptomatic patient. The patient had no signs of infection or erosion and no voiding complaints. His only problem was that his urinary catheter was not able to be placed during his vascular surgery procedure., Methods: Patient with a 5-year history of erectile dysfunction refractory to therapy with PDE5 inhibitors, injection therapy, and vacuum erection device therapy underwent placement of an Alpha-1 Mentor inflatable penile prosthesis. The patient underwent femoral-popliteal bypass at month 21, and during the procedure, the vascular service was unable to place a urinary catheter. Erosion of the tubing from his penile prosthesis was then noted at approximately the junction between the membranous and bulbar urethra., Results: Patient was without signs of infection and had no voiding complaints. These findings were discovered because of the inability to place a urinary catheter for his femoral-popliteal bypass. Diagnosis was made by flexible cystoscopy., Conclusions: No evidence of infection was noted on examination, and the patient was otherwise asymptomatic. Diagnosis can be made by flexible cystoscopy. Subsequent removal of the penile implant was curative.
- Published
- 2008
- Full Text
- View/download PDF
31. Prions in the environment: occurrence, fate and mitigation.
- Author
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Saunders SE, Bartelt-Hunt SL, and Bartz JC
- Subjects
- Animals, Humans, Prions chemistry, Soil Microbiology, Disease Reservoirs, Environment, Prion Diseases transmission, Prions isolation & purification, Soil analysis
- Abstract
Scrapie and CWD are horizontally transmissible, and the environment likely serves as a stable reservoir of infectious prions, facilitating a sustained incidence of CWD in free-ranging cervid populations and complicating efforts to eliminate disease in captive herds. Prions will enter the environment through mortalities and/or shedding from live hosts. Unfortunately, a sensitive detection method to identify prion contamination in environmental samples has not yet been developed. An environmentally-relevant prion model must be used in experimental studies. Changes in PrP(Sc) structure upon environmental exposure may be as significant as changes in PrP(Sc) quantity, since the structure can directly affect infectivity and disease pathology. Prions strongly bind to soil and remain infectious. Conformational changes upon adsorption, competitive sorption and potential for desorption and transport all warrant further investigation. Mitigation of contaminated carcasses or soil might be accomplished with enzyme treatments or composting in lieu of incineration.
- Published
- 2008
- Full Text
- View/download PDF
32. Environmentally-relevant forms of the prion protein.
- Author
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Saunders SE, Bartz JC, Telling GC, and Bartelt-Hunt SL
- Subjects
- Animals, Blotting, Western, Cricetinae, Hydrolysis, Mink, Prion Diseases transmission, Prions chemistry
- Abstract
Scrapie and chronic wasting disease (CWD) are prion diseases of particular environmental concern as they are horizontally transmissible and can remain infectious after years in the environment. Recent evidence suggests that the N-terminus of PrPSC, the infectious conformation of the prion protein, plays an important role in the mechanism of sorption to soil particles. We hypothesize that, in a prion-infected animal carcass, a portion of the N-terminus of PrPSc could be cleaved by proteinases in the brain at ordinary temperatures. Hamster (HY transmissible mink encephalopathy-infected), transgenic mice (CWD-infected), and elk (CWD-infected) brain homogenates were incubated at 22 and 37 degrees C for up to 1 month and then analyzed by Western blot using N-terminal and middle region monoclonal anti-PrP antibodies. For all three systems, there was a very faint or undetectable N-terminal PrP signal after 35 days at both temperatures, which indicates that full-length PrPSc might be rare in the brain matter of animal carcasses. Future studies on prion-soil interactions should therefore consider N-terminal-degraded PrPSc in addition to the full-length form. Both mouse and elk CWD PrPSc demonstrated greater resistance to degradation than HY TME PrPSc. This indicates that the transgenic mouse-CWD model is a good surrogate for natural CWD prions, but that other rodent prion models might not accurately represent CWD prion fate in the environment.
- Published
- 2008
- Full Text
- View/download PDF
33. ADHD-like hyperactivity, with no attention deficit, in adult rats after repeated hypoxia during the equivalent of extreme prematurity.
- Author
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Oorschot DE, Voss L, Covey MV, Bilkey DK, and Saunders SE
- Subjects
- Age Factors, Animals, Animals, Newborn, Behavior, Animal, Conditioning, Operant physiology, Disease Models, Animal, Extinction, Psychological, Female, Male, Pregnancy, Rats, Brain growth & development, Brain pathology, Brain physiopathology, Hyperkinesis physiopathology, Hypoxia physiopathology
- Abstract
The most common behavioural disorder seen in children and adolescents born extremely prematurely is attention deficit hyperactivity disorder (ADHD). The hyperactive/impulsive sub-type of ADHD or the inattentive sub-type or the hyperactive/impulsive/inattentive sub-type can be evident. These sub-types of ADHD can persist into adulthood. The aim of this study was to investigate the relevance of a new immature rat model of repeated hypoxic exposure to these behavioural characteristics of extreme prematurity. More specifically, this study aimed to measure ADHD-like hyperactivity in response to delayed reward, and inattention, in repeated hypoxic versus repeated normoxic rats. Sprague-Dawley rats were exposed to either repeated hypoxia or repeated normoxia during postnatal days (PN) 1-3. The rat brain during PN1-3 is generally considered to be developmentally equivalent to the human brain during extreme prematurity. The rats were then behaviourally tested at 16 months-of-age on a multiple component fixed interval-extinction test. This test detects ADHD-like hyperactivity in response to delayed reward, as well as inattention. It was found that the repeated hypoxic rats exhibited ADHD-like hyperactivity in response to delayed reward, but no attention deficit, when compared to repeated normoxic rats. These findings provide a new animal model to investigate the biological mechanisms and treatment of ADHD-like hyperactivity due to repeated hypoxia during the equivalent of extreme prematurity.
- Published
- 2007
- Full Text
- View/download PDF
34. Pancreatic pseudocyst masquerading as renal injury on imaging studies.
- Author
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Talug C, Mullins J, Saunders SE, and Zaslau S
- Subjects
- Adult, Cholangiopancreatography, Endoscopic Retrograde, Diagnosis, Differential, Drainage, Endoscopy, Female, Humans, Pancreatic Pseudocyst surgery, Stents, Kidney injuries, Pancreatic Pseudocyst diagnosis
- Abstract
In a patient with a prior history of pancreatitis or abdominal trauma, radiographic imaging may only show abnormalities in the urinary tract. When these patients are first seen with subcapsular or perinephric fluid collections, percutaneous drainage can be both diagnostic and therapeutic.
- Published
- 2007
35. Primary synovial sarcoma of the kidney.
- Author
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Perlmutter AE, Saunders SE, Zaslau S, Chang WW, and Farivar-Mohseni H
- Subjects
- Female, Humans, Kidney Neoplasms genetics, Magnetic Resonance Imaging, Middle Aged, Oncogene Proteins, Fusion genetics, Sarcoma genetics, Kidney Neoplasms pathology, Sarcoma pathology, Synovial Membrane pathology
- Abstract
Primary renal synovial sarcomas (SS) are rare tumors of the kidney. Faria first described primary renal synovial sarcoma in 1999. Twenty-one cases of primary renal synovial sarcoma have been reported to date. Primary renal synovial sarcomas can exist in either a monophasic or a biphasic pattern. The monophasic variant of primary renal synovial sarcoma is more common and tends to have a better prognosis than the biphasic variant. We present the case of a 61 year-old woman with a monophasic variant of primary renal synovial sarcoma.
- Published
- 2005
- Full Text
- View/download PDF
36. The effect of the Family Case Management Program on 1996 birth outcomes in Illinois.
- Author
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Keeton K, Saunders SE, and Koltun D
- Subjects
- Adult, Chi-Square Distribution, Confidence Intervals, Family Health, Female, Follow-Up Studies, Humans, Illinois epidemiology, Infant, Low Birth Weight, Infant, Newborn, Odds Ratio, Pregnancy, Program Evaluation, Risk Factors, Time Factors, Case Management, Medicaid standards, Mothers education, Poverty statistics & numerical data, Pregnancy Outcome epidemiology, Prenatal Care organization & administration
- Abstract
Objectives: The purpose of this study was to determine if birth outcomes for Medicaid recipients were improved with participation in the Illinois Family Case Management Program., Methods: Health program data files were linked with the 1996 Illinois Vital Records linked birth-death certificate file. Logistic regression was used to characterize the variation in birth outcomes as a function of Family Case Management participation while statistically controlling for measurable factors found to be confounders., Results: Results of the logistic regression analysis show that women who participated in the Family Care Management Program were significantly less likely to give birth to very low birth weight infants (odds ratio [OR] = 0.86, 95% confidence interval [CI] = 0.75, 0.99) and low birth weight infants (OR = 0.83, CI = 0.79, 0.89). For infant mortality, however, the adjusted OR (OR = 0.98, CI = 0.82, 1.17), although under 1, was not statistically significant., Conclusions: These results suggest that the Family Case Management Program may be effective in reducing very low birth weight and low birth weight rates among infants born to low-income women.
- Published
- 2004
- Full Text
- View/download PDF
37. Multimeric CREB-binding sites in the promoter regions of a family of G-protein-coupled receptors related to the vertebrate galanin and nociceptin/orphanin-FQ receptor families.
- Author
-
Saunders SE, Burke JF, and Benjamin PR
- Subjects
- Animals, Base Sequence, Central Nervous System chemistry, Cloning, Molecular, GTP-Binding Proteins metabolism, Ganglia, Invertebrate chemistry, Gene Expression Regulation physiology, In Situ Hybridization, Lymnaea, Molecular Sequence Data, Neurons chemistry, Neurons physiology, RNA, Messenger analysis, Sequence Homology, Amino Acid, Signal Transduction physiology, Nociceptin, Cyclic AMP Response Element-Binding Protein metabolism, GTP-Binding Proteins genetics, Galanin genetics, Opioid Peptides genetics, Promoter Regions, Genetic physiology, Receptors, Neuropeptide genetics
- Abstract
Four related genes encoding a family of G-protein-coupled receptors (GPCRs) have been isolated from the mollusc Lymnaea stagnalis. The coding regions of this family of receptors share 97-99% sequence similarity at both the protein and nucleotide level, and they also share high sequence identity with vertebrate galanin and orphanin-FQ/nociceptin GPCR families. Analysis of the promoter regions reveals shared domains, some of which encode highly conserved repeating units. One 27-bp repeating unit, which encodes a c-AMP response element (CRE) and binds CREB protein, is repeated 14 times in one promoter. In situ hybridization showed expression of these receptors in identified neurons of several behaviourly important networks including those involved in feeding and ion and water regulation. These Lymnaea receptors are likely to represent members of a novel family of invertebrate neuropeptide receptors extensively regulated in response to intracellular signalling cascades.
- Published
- 2000
- Full Text
- View/download PDF
38. Obesity in North America. An overview.
- Author
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Allison DB and Saunders SE
- Subjects
- Adolescent, Adult, Aged, Cause of Death, Cross-Sectional Studies, Female, Humans, Incidence, Male, Middle Aged, Obesity complications, Obesity psychology, Social Adjustment, United States epidemiology, Obesity mortality
- Abstract
The terms "obesity" and "overweight" mean different things to different people. This article discusses such issues as prevalence, morbidity, mortality, and psychosocial effects. Definitions and various classifications of obesity are discussed also.
- Published
- 2000
- Full Text
- View/download PDF
39. Extender PCR: a method for the isolation of sequences regulating gene expression from genomic DNA.
- Author
-
Brown AJ, Perry SJ, Saunders SE, and Burke JF
- Subjects
- Animals, Base Sequence, Biotechnology, DNA Primers genetics, Decapoda genetics, Evaluation Studies as Topic, Gene Expression, Genome, Promoter Regions, Genetic, Rod Opsins genetics, DNA genetics, DNA isolation & purification, Polymerase Chain Reaction methods
- Published
- 1999
- Full Text
- View/download PDF
40. Intracoronary Stent Placement without Coumadin or Intravascular Ultrasound.
- Author
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Lawrence ME, Burtt DM, Shaftel PA, Saunders SE, Korr KS, and Gordon PC
- Abstract
Coronary stenting has been associated with the need for intravascular ultrasound, increased anticoagulation, and increased length of stay. We evaluated the use of ticlopidine and aspirin without ultrasound in 322 consecutive patients from February 1995 through January 1996 who underwent intracoronary stenting with adjunctive high pressure balloon angioplasty [mean peak atmospheres (ATM) = 15.9; mean post-dilating balloon size = 3.4 mm]. Unstable coronary syndrome was the admitting diagnosis in 66% of these patients. Post-stent anticoagulation consisted of overnight heparin, followed by aspirin (325 mg daily) and ticlopidine (250 mg twice daily) for 4 to 6 weeks. Among the 322 patients, 575 stents (Palmaz-Schatz Coronary Stents = 530; Palmaz-Schatz Biliary Stents = 33; Gianturco-Roubin Stents = 12) were implanted in 338 coronary vessels (native arteries = 316; saphenous vein grafts = 22). Twenty-three patients (7%) had multi-vessel stenting. Average length of stay following stenting was 1.6 days (average overall hospital length of stay was 2.3 days), and 71% of patients were discharged the next day. Follow-up of all 322 patients was performed by telephone contact at least 30 days after discharge. During this period 1 (0.3%) acute thrombosis and no subacute thrombosis occurred. In this series of patients, coronary stent implantation using routine high pressure balloon post-dilatation Ñ without intravascular ultrasound Ñ and a combination of aspirin and ticlopidine was performed with no subacute thrombosis and a short length of stay.
- Published
- 1996
41. Maternal and child health and health care reform.
- Author
-
Saunders SE, Hess CA, Nelson RP, and Petersen DJ
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Female, Health Status, Humans, Infant, Infant, Newborn, Male, Minnesota, Pregnancy, United States epidemiology, Child Health Services organization & administration, Health Care Reform legislation & jurisprudence, Maternal Health Services organization & administration
- Abstract
Women and children, because of particular characteristics and vulnerabilities, should be afforded special attention in health care reform. Health care reform provides an opportunity to positively affect the maternal and child health (MCH) status. Universal coverage of a comprehensive benefit package must be combined with a strong public health system of population-based services if benefits are to be realized. There must be an accountable public locus of responsibility for promoting MCH, including clear authority and resources for four primary activities: (1) core public health, (2) systems development, (3) coordinated services for children with special health care needs, and (4) access to care.
- Published
- 1995
- Full Text
- View/download PDF
42. Drosophila integrins and their ligands.
- Author
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Gotwals PJ, Paine-Saunders SE, Stark KA, and Hynes RO
- Subjects
- Alternative Splicing, Amino Acid Sequence, Animals, Drosophila genetics, Drosophila growth & development, Extracellular Matrix physiology, Integrin alpha Chains, Integrins genetics, Ligands, Models, Biological, Molecular Sequence Data, Oligopeptides genetics, Oligopeptides physiology, Drosophila physiology, Drosophila Proteins, Integrins physiology
- Abstract
The major advance during the past year was the identification of ligands for two of the previously known position-specific integrins in Drosophila. At the same time, two new Drosophila integrin subunits (one alpha and one beta) were discovered, and significant progress was made on developmental genetic analyses of integrin functions, shedding light on the roles of integrins in Drosophila development.
- Published
- 1994
- Full Text
- View/download PDF
43. Drosophila syndecan: conservation of a cell-surface heparan sulfate proteoglycan.
- Author
-
Spring J, Paine-Saunders SE, Hynes RO, and Bernfield M
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Chromosome Mapping, Cloning, Molecular, DNA Primers chemistry, Drosophila Proteins genetics, Drosophila Proteins metabolism, Drosophila melanogaster embryology, Drosophila melanogaster genetics, Genes, Insect, Membrane Glycoproteins genetics, Membrane Glycoproteins metabolism, Molecular Sequence Data, Proteoglycans genetics, Proteoglycans metabolism, Sequence Alignment, Sequence Homology, Amino Acid, Solubility, Syndecans genetics, Syndecans metabolism, Drosophila Proteins chemistry, Drosophila melanogaster chemistry, Membrane Glycoproteins chemistry, Proteoglycans chemistry, Syndecans chemistry
- Abstract
In mammals, cell-surface heparan sulfate is required for the action of basic fibroblast growth factor, fibronectin, antithrombin III, as well as other effectors. The syndecans, a gene family of four transmembrane proteoglycans that participates in these interactions, are the major source of this heparan sulfate. Based on the conserved transmembrane and cytoplasmic domains of the mammalian syndecans, a single syndecan-like gene was detected and localized in the Drosophila genome. As in mammals, Drosophila syndecan is a heparan sulfate proteoglycan expressed at the cell surface that can be shed from cultured cells. The single Drosophila syndecan is expressed in embryonic tissues that correspond with those tissues in mammals that express distinct members of the syndecan family predominantly. Conservation of this class of molecules suggests that Drosophila, like mammals, uses cell-surface heparan sulfate as a receptor or coreceptor for extracellular effector molecules.
- Published
- 1994
- Full Text
- View/download PDF
44. Is there lead in the suburbs? Risk assessment in Chicago suburban pediatric practices. Pediatric Practice Research Group.
- Author
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Binns HJ, LeBailly SA, Poncher J, Kinsella TR, and Saunders SE
- Subjects
- Centers for Disease Control and Prevention, U.S., Chicago epidemiology, Child, Preschool, Cost-Benefit Analysis, Environmental Exposure analysis, Evaluation Studies as Topic, Humans, Infant, Lead Poisoning diagnosis, Lead Poisoning prevention & control, Predictive Value of Tests, Prevalence, Risk Factors, Sensitivity and Specificity, United States, Lead blood, Lead Poisoning epidemiology, Mass Screening methods, Suburban Population, Surveys and Questionnaires
- Abstract
Objective: This study was designed to determine: (1) the prevalence of elevated blood lead (BPb) levels (BPb > or = 10 micrograms/dL) in Chicago suburban children attending Pediatric Practice Research Group practices at 12 and 24 months of age, and (2) the efficacy of the Centers for Disease Control and Prevention (CDC) and Illinois lead exposure risk assessment questions., Methods: Parents bringing their 1- and 2-year-old children for health supervision visits at pediatric practices completed questionnaires. BPb levels were drawn on children. Both questionnaire and an analyzable BPb level were obtained on 1393 subjects (79.2%)., Results: Only 2.1% of our sample had a venous BPb level > or = 10 micrograms/dL (0.48 mumol/L); no subjects had a level > or = 30 micrograms/dL (1.45 mumol/L). The CDC risk assessment questions had a sensitivity of .69 and specificity of .70. Due to the low prevalence of elevated BPb levels in this sample, CDC and Illinois screening strategies had high negative predictive values (.99) and low positive predictive values (.05 and .04, respectively). However, some of the subjects with BPb levels > or = 10 micrograms/dL were not at high risk by CDC and Illinois screening questions; 9 of 29 subjects with elevated lead levels (31%) did not respond affirmatively to any CDC risk assessment questions. The question best predicting an elevated BPb was the determination that the house the child lives in was built before 1960 (sensitivity = .83, specificity = .67). This question is not currently included in CDC or Illinois screening strategies. Screening based on the single question "Was your house built before 1960?" would have missed only five (17%) of the children with BPb levels > or = 10 micrograms/dL. Three of these five children were among the 17.1% of 1-year-olds and 26.3% of 2-year-olds in our sample who had moved., Conclusions: In this sample, children living in houses built before 1960 should be considered at high risk for high-dose lead exposure. Due to the high mobility of our sample, phrasing the question to include lifetime exposure (ie, Has your child ever lived in a house built before 1960?) should also be considered. Selective BPb testing of high-risk children in low-prevalence suburban areas using this question would miss few children with elevated BPb. Useful risk assessment questions in other areas and other populations may differ.
- Published
- 1994
45. Alternative mRNA splicing in the nervous system.
- Author
-
Burke JF, Bright KE, Kellett E, Benjamin PR, and Saunders SE
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, FMRFamide, Lymnaea, Molecular Sequence Data, Protein Precursors genetics, Tachykinins genetics, Transcription, Genetic, Alternative Splicing, Nervous System Physiological Phenomena, Neurons physiology, Neuropeptides genetics, RNA, Messenger genetics
- Published
- 1992
- Full Text
- View/download PDF
46. Rapid isolation of miniprep DNA for double strand sequencing.
- Author
-
Saunders SE and Burke JF
- Subjects
- Base Sequence, DNA analysis, Sequence Homology, Nucleic Acid, DNA isolation & purification, Genetic Techniques
- Published
- 1990
- Full Text
- View/download PDF
47. EBNA-1: a virally induced nuclear antigen of primate lymphocytes and its expression in Drosophila cells.
- Author
-
MacGillivray AJ, Allday MJ, Saunders SE, and Sinclair JH
- Subjects
- Animals, Cell Transformation, Viral, Cells, Cultured, Cosmids, Epitopes genetics, Epstein-Barr Virus Nuclear Antigens, Heat-Shock Proteins genetics, Herpesvirus 4, Human genetics, Humans, Immunoblotting, Molecular Weight, Polymorphism, Genetic, Transfection, Vimentin genetics, Antigens, Viral genetics, Cell Nucleus immunology, Drosophila genetics, Gene Expression Regulation, Herpesvirus 4, Human immunology, Lymphocytes immunology
- Abstract
EBNA-1 is a nuclear antigen of lymphocytes infected by Epstein-Barr virus and whose size polymorphism correlates only with the strain of infecting virus and the length of the glycine-alanine copolymer encoded by the third internal repeat of the viral genome. The major antigenic determinant(s) also appear to reside in this region. We have been able to obtain efficient expression of this nuclear antigen in cultured Drosophila cells transfected with a cosmid carrying the EBNA-1 coding region, indicating that insect mechanisms recognise control sequences and transcripts of the herpes virus. The association of a vimertin-like protein of mol. wt. 46,000 with Drosophila cell nuclei has been found to vary with culture conditions and heat shock. We now find that the level and nuclear association of this protein also increase after transfection with either EBNA-1 or yolk protein DNA.
- Published
- 1988
48. High efficiency expression of transfected genes in a Drosophila melanogaster haploid (1182) cell line.
- Author
-
Saunders SE, Rawls JM, Wardle CJ, and Burke JF
- Subjects
- Animals, Calcium Phosphates, Cell Line, Chemical Precipitation, Chloramphenicol O-Acetyltransferase genetics, Cloning, Molecular, DNA genetics, DNA Replication, Haploidy, Plasmids, Transcription, Genetic, Drosophila melanogaster genetics, Gene Expression Regulation, Promoter Regions, Genetic, Transfection
- Abstract
Drosophila tissue culture cells have been important in the study of homologous promoters and more recently in the study of mammalian transcriptional factors such as CTF and SP1 which bind and stimulate transcription from transfected genes. In this paper we show that a Drosophila melanogaster haploid cell line (1182-4), not previously used for transfection studies, is capable of taking up and expressing DNA without the use of a facilitating agent such as calcium phosphate. Furthermore expression from a variety of Drosophila promoters such as copia, heatshock and rudimentary as well as a mammalian promoter RSV-LTR, show between 20 and over 100 times more activity in 1182-4 cells than in D.hydei DH33 or D.melanogaster S3, or D1 cell lines. This cell line should prove to be particularly useful for the analysis of weak promoters and heterologous transcription factors.
- Published
- 1989
- Full Text
- View/download PDF
49. Regulated expression of a Drosophila melanogaster heat shock locus after stable integration in a Drosophila hydei cell line.
- Author
-
Sinclair JH, Saunders SE, Burke JF, and Sang JH
- Subjects
- Animals, Cell Line, Cloning, Molecular, Escherichia coli genetics, Genetic Vectors, Nucleic Acid Hybridization, Plasmids, Drosophila genetics, Drosophila melanogaster genetics, Genes, Heat-Shock Proteins genetics, Transcription, Genetic
- Abstract
DNA-mediated cotransformation has been used to transfer a Drosophila melanogaster heat shock locus into cultured Drosophila hydei cells by use of the copia-based selectable vector pCV2gpt and of pMH10A, a cloned 87A7 heat shock locus encoding a mutant heat shock protein (hsp). Transformed lines contain between 50 and 200 copies of both plasmids, each separately organized as a head-to-tail concatemer which is stably maintained in the transformed lines. Exposure of the cotransformants to heat shock temperatures induces the regulated expression of the hsp RNA and the mutant hsp in all the lines analyzed.
- Published
- 1985
- Full Text
- View/download PDF
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