720 results on '"A. L. Nichols"'
Search Results
2. Glucose confers protection to Escherichia coli against contact killing by Vibrio cholerae
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Cristian V. Crisan, Holly L. Nichols, Sophia Wiesenfeld, Gabi Steinbach, Peter J. Yunker, and Brian K. Hammer
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Medicine ,Science - Abstract
Abstract Evolutionary arms races are broadly prevalent among organisms including bacteria, which have evolved defensive strategies against various attackers. A common microbial aggression mechanism is the type VI secretion system (T6SS), a contact-dependent bacterial weapon used to deliver toxic effector proteins into adjacent target cells. Sibling cells constitutively express immunity proteins that neutralize effectors. However, less is known about factors that protect non-sibling bacteria from T6SS attacks independently of cognate immunity proteins. In this study, we observe that human Escherichia coli commensal strains sensitive to T6SS attacks from Vibrio cholerae are protected when co-cultured with glucose. We confirm that glucose does not impair V. cholerae T6SS activity. Instead, we find that cells lacking the cAMP receptor protein (CRP), which regulates expression of hundreds of genes in response to glucose, survive significantly better against V. cholerae T6SS attacks even in the absence of glucose. Finally, we show that the glucose-mediated T6SS protection varies with different targets and killers. Our findings highlight the first example of an extracellular small molecule modulating a genetically controlled response for protection against T6SS attacks. This discovery may have major implications for microbial interactions during pathogen-host colonization and survival of bacteria in environmental communities.
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- 2021
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3. Fluorescence activation mechanism and imaging of drug permeation with new sensors for smoking-cessation ligands
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Aaron L Nichols, Zack Blumenfeld, Chengcheng Fan, Laura Luebbert, Annet EM Blom, Bruce N Cohen, Jonathan S Marvin, Philip M Borden, Charlene H Kim, Anand K Muthusamy, Amol V Shivange, Hailey J Knox, Hugo Rego Campello, Jonathan H Wang, Dennis A Dougherty, Loren L Looger, Timothy Gallagher, Douglas C Rees, and Henry A Lester
- Subjects
pharmacokinetics ,nicotine ,biosensors ,nicotinic agonists ,iDrugSnFRs ,inside-out pharmacology ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Nicotinic partial agonists provide an accepted aid for smoking cessation and thus contribute to decreasing tobacco-related disease. Improved drugs constitute a continued area of study. However, there remains no reductionist method to examine the cellular and subcellular pharmacokinetic properties of these compounds in living cells. Here, we developed new intensity-based drug-sensing fluorescent reporters (iDrugSnFRs) for the nicotinic partial agonists dianicline, cytisine, and two cytisine derivatives – 10-fluorocytisine and 9-bromo-10-ethylcytisine. We report the first atomic-scale structures of liganded periplasmic binding protein-based biosensors, accelerating development of iDrugSnFRs and also explaining the activation mechanism. The nicotinic iDrugSnFRs detect their drug partners in solution, as well as at the plasma membrane (PM) and in the endoplasmic reticulum (ER) of cell lines and mouse hippocampal neurons. At the PM, the speed of solution changes limits the growth and decay rates of the fluorescence response in almost all cases. In contrast, we found that rates of membrane crossing differ among these nicotinic drugs by >30-fold. The new nicotinic iDrugSnFRs provide insight into the real-time pharmacokinetic properties of nicotinic agonists and provide a methodology whereby iDrugSnFRs can inform both pharmaceutical neuroscience and addiction neuroscience.
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- 2022
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4. Transcriptome analysis of a nematode resistant and susceptible upland cotton line at two critical stages of Meloidogyne incognita infection and development.
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Pawan Kumar, Sameer Khanal, Mychele Da Silva, Rippy Singh, Richard F Davis, Robert L Nichols, and Peng W Chee
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Medicine ,Science - Abstract
Host plant resistance is the most practical approach to control the Southern root-knot nematode (Meloidogyne incognita; RKN), which has emerged as one of the most serious economic pests of Upland cotton (Gossypium hirsutum L.). Previous QTL analyses have identified a resistance locus on chromosome 11 (qMi-C11) affecting galling and another locus on chromosome-14 (qMi-C14) affecting egg production. Although these two QTL regions were fine mapped and candidate genes identified, expression profiling of genes would assist in further narrowing the list of candidate genes in the QTL regions. We applied the comparative transcriptomic approach to compare expression profiles of genes between RKN susceptible and resistance genotypes at an early stage of RKN development that coincides with the establishment of a feeding site and at the late stage of RKN development that coincides with RKN egg production. Sequencing of cDNA libraries produced over 315 million reads of which 240 million reads (76%) were mapped on to the Gossypium hirsutum genome. A total of 3,789 differentially expressed genes (DEGs) were identified which were further grouped into four clusters based on their expression profiles. A large number of DEGs were found to be down regulated in the susceptible genotype at the late stage of RKN development whereas several genes were up regulated in the resistant genotype. Key enriched categories included transcription factor activity, defense response, response to phyto-hormones, cell wall organization, and protein serine/threonine kinase activity. Our results also show that the DEGs in the resistant genotype at qMi-C11 and qMi-C14 loci displayed higher expression of defense response, detoxification and callose deposition genes, than the DEGs in the susceptible genotype.
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- 2019
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5. Leveraging the electronic health record to eliminate hepatitis C: Screening in a large integrated healthcare system.
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Alexander G Geboy, Whitney L Nichols, Stephen J Fernandez, Sameer Desale, Peter Basch, and Dawn A Fishbein
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Medicine ,Science - Abstract
Highly efficacious and tolerable treatments that cure hepatitis C viral (HCV) infection exist today, increasing the feasibility of disease elimination. However, large healthcare systems may not be fully prepared for supporting recommended actions due to knowledge gaps, inadequate infrastructure and uninformed policy direction. Additionally, the HCV cascade of care is complex, with many embedded barriers, and a significant number of patients do not progress through the cascade and are thus not cured. The aim of this retrospective cohort study was to evaluate a large healthcare system's HCV screening rates, linkage to care efficiency, and provider testing preferences. Patients born during 1945-1965, not previously HCV positive or tested from within the Electronic Health Record (EHR), were identified given that three-quarters of HCV-infected persons in the United States are from this Birth Cohort (BC). In building this HCV testing EHR prompt, non-Birth Cohort patients were excluded as HCV-specific risk factors identifying this population were not usually captured in searchable, structured data fields. Once completed, the BC prompt was released to primary care locations. From July 2015 through December 2016, 11.5% of eligible patients (n = 9,304/80,556) were HCV antibody tested (anti-HCV), 3.8% (353/9,304) anti-HCV positive, 98.1% (n = 311/317) HCV RNA tested, 59.8% (n = 186/311) HCV RNA positive, 86.6% (161/186) referred and 76.4% (n = 123/161) seen by a specialist, and 34.1% (n = 42/123) cured of their HCV. Results from the middle stages of the cascade in this large healthcare system are encouraging; however, entry into the cascade-HCV testing-was performed for only 11% of the birth cohort, and the endpoint-HCV cure-accounted for only 22% of all infected. Action is needed to align current practice with recommendations for HCV testing and treatment given that these are significant barriers toward elimination.
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- 2019
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6. Physiological Responses to Multiple Low-Doses of Bacillus anthracis Spores in the Rabbit Model of Inhalation Anthrax
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Sarah C. Taft, Tonya L. Nichols, Stephanie A. Hines, Roy E. Barnewall, Gregory V. Stark, and Jason E. Comer
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Bacillus anthracis ,anthrax ,low-dose ,multiple dose ,dose-response ,physiological response ,Medicine - Abstract
Bacillus anthracis spores that are re-aerosolized from surface deposits after initial contamination present significant health risks for personnel involved in decontamination. To model repeated exposure to low dose B. anthracis spores, three groups of seven rabbits were challenged with multiple low-doses of B. anthracis spores 5 days a week for 3 weeks. Mortality, body temperature, heart and respiration rates, hematology, C-reactive protein, bacteremia, and serum protective antigen were monitored for 21 days post-exposure after the last of multiple doses. All rabbits exposed to a mean daily dose of 2.91 × 102 colony forming units (CFU) survived and showed minimal physiological changes attributable to exposure. One of seven rabbits receiving a mean daily dose of 1.22 × 103 CFU died and four of seven receiving a mean daily dose of 1.17 × 104 CFU died. The LD50 was calculated to be 8.1 × 103 CFU of accumulated dose. Rabbits that succumbed to the higher dose exhibited bacteremia and increases above baseline in heart rate, respiration rate, and body temperature. Two rabbits in the mean daily dose group of 1.17 × 104 CFU exhibited clinical signs of inhalation anthrax yet survived. This study provides a description of lethality, pathophysiology, and pathology in a controlled multiple low-dose inhalation exposure study of B. anthracis in the rabbit model. The data suggest that the accumulated dose is important in survival outcome and that a subset of rabbits may show clinical signs of disease but fully recover without therapeutic intervention
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- 2020
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7. Physiological Responses to a Single Low-Dose of Bacillus anthracis Spores in the Rabbit Model of Inhalational Anthrax
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Sarah C. Taft, Tonya L. Nichols, Stephanie A. Hines, Roy E. Barnewall, Gregory V. Stark, and Jason E. Comer
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Bacillus anthracis ,anthrax ,low-dose ,dose–response ,physiological response ,Medicine - Abstract
Credible dose–response relationships are needed to more accurately assess the risk posed by exposure to low-level Bacillus anthracis contamination during or following a release. To begin to fill this knowledge gap, New Zealand White rabbits were implanted with D70-PCT telemetry transmitters and subsequently aerosol challenged with average inhaled doses of 2.86 × 102 to 2.75 × 105 colony forming units (CFU) of B. anthracis spores. Rabbits exposed to a single inhaled dose at or above 2.54 × 104 CFU succumbed with dose-dependent time to death. Death was associated with increases above baseline in heart rate, respiration rate, and body temperature and all rabbits that died exhibited bacteremia at some point prior to death. Rabbits that inhaled doses of 2.06 × 103 CFU or lower survived to the end of the study and showed no or minimal adverse changes in the measured physiological responses in response to the challenge. Moreover, no bacteremia nor toxemia were observed in rabbits that survived to the end of the study. Overall, the data indicate that challenge doses of B. anthracis below the level sufficient to establish systemic infection do not produce observable physiological responses; however, doses that triggered a response resulted in death.
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- 2020
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8. RNA-Seq transcriptome analysis of Amaranthus palmeri with differential tolerance to glufosinate herbicide.
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Reiofeli A Salas-Perez, Christopher A Saski, Rooksana E Noorai, Subodh K Srivastava, Amy L Lawton-Rauh, Robert L Nichols, and Nilda Roma-Burgos
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Medicine ,Science - Abstract
Amaranthus palmeri (Amaranthaceae) is a noxious weed in several agroecosystems and in some cases seriously threatens the sustainability of crop production in North America. Glyphosate-resistant Amaranthus species are widespread, prompting the use of alternatives to glyphosate such as glufosinate, in conjunction with glufosinate-resistant crop cultivars, to help control glyphosate-resistant weeds. An experiment was conducted to analyze the transcriptome of A. palmeri plants that survived exposure to 0.55 kg ha-1 glufosinate. Since there was no record of glufosinate use at the collection site, survival of plants within the population are likely due to genetic expression that pre-dates selection; in the formal parlance of weed science this is described as natural tolerance. Leaf tissues from glufosinate-treated and non-treated seedlings were harvested 24 h after treatment (HAT) for RNA-Seq analysis. Global gene expression was measured using Illumina DNA sequence reads from non-treated and treated surviving (presumably tolerant, T) and susceptible (S) plants. The same plants were used to determine the mechanisms conferring differential tolerance to glufosinate. The S plants accumulated twice as much ammonia as did the T plants, 24 HAT. The relative copy number of the glufosinate target gene GS2 did not differ between T and S plants, with 1 to 3 GS2 copies in both biotypes. A reference cDNA transcriptome consisting of 72,780 contigs was assembled, with 65,282 sequences putatively annotated. Sequences of GS2 from the transcriptome assembly did not have polymorphisms unique to the tolerant plants. Five hundred sixty-seven genes were differentially expressed between treated T and S plants. Of the upregulated genes in treated T plants, 210 were more highly induced than were the upregulated genes in the treated S plants. Glufosinate-tolerant plants had greater induction of ABC transporter, glutathione S-transferase (GST), NAC transcription factor, nitronate monooxygenase (NMO), chitin elicitor receptor kinase (CERK1), heat shock protein 83, ethylene transcription factor, heat stress transcription factor, NADH-ubiquinone oxidoreductase, ABA 8'-hydroxylase, and cytochrome P450 genes (CYP72A, CYP94A1). Seven candidate genes were selected for validation using quantitative real time-PCR. While GST was upregulated in treated tolerant plants in at least one population, CYP72A219 was consistently highly expressed in all treated tolerant biotypes. These genes are candidates for contributing tolerance to glufosinate. Taken together, these results show that differential induction of stress-protection genes in a population can enable some individuals to survive herbicide application. Elevated expression of detoxification-related genes can get fixed in a population with sustained selection pressure, leading to evolution of resistance. Alternatively, sustained selection pressure could select for mutation(s) in the GS2 gene with the same consequence.
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- 2018
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9. The Ighmbp2D564N mouse model is the first SMARD1 model to demonstrate respiratory defects
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Jose Marquez, Zayd Al Rawi, Elizabeth C. Bryda, Daniel J. Davis, Mona O. Garro-Kacher, Caley E. Smith, Christian L. Lorson, Catherine L Smith, Nicole L. Nichols, Amy N Keilholz, Jiude Mao, Eric Villalón, Sara M. Ricardez Hernandez, Toni I. Morcos, and Monique A. Lorson
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Pathology ,medicine.medical_specialty ,Sensory system ,Disease ,Biology ,Muscular Atrophy, Spinal ,Mice ,Genetics ,medicine ,Animals ,Humans ,Respiratory system ,Molecular Biology ,Genetics (clinical) ,Respiratory Distress Syndrome, Newborn ,Respiratory distress ,Neurodegenerative Diseases ,General Medicine ,Spinal muscular atrophy ,medicine.disease ,Phenotype ,Muscle atrophy ,DNA-Binding Proteins ,Disease Models, Animal ,Muscular Atrophy ,Autonomic nervous system ,Mutation ,General Article ,medicine.symptom ,Transcription Factors - Abstract
Spinal muscular atrophy with respiratory distress type I (SMARD1) is a neurodegenerative disease defined by respiratory distress, muscle atrophy and sensory and autonomic nervous system defects. SMARD1 is a result of mutations within the IGHMBP2 gene. We have generated six Ighmbp2 mouse models based on patient-derived mutations that result in SMARD1 and/or Charcot-Marie Tooth Type 2 (CMT2S). Here we describe the characterization of one of these models, Ighmbp2D564N (human D565N). The Ighmbp2D564N/D564N mouse model mimics important aspects of the SMARD1 disease phenotype, including motor neuron degeneration and muscle atrophy. Ighmbp2D564N/D564N is the first SMARD1 mouse model to demonstrate respiratory defects based on quantified plethysmography analyses. SMARD1 disease phenotypes, including the respiratory defects, are significantly diminished by intracerebroventricular (ICV) injection of ssAAV9-IGHMBP2 and the extent of phenotypic restoration is dose-dependent. Collectively, this model provides important biological insight into SMARD1 disease development.
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- 2021
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10. Pioneer Axons Utilize a Dcc Signaling-Mediated Invasion Brake to Precisely Complete Their Pathfinding Odyssey
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Kurt C. Marsden, Abigail M. Zellmer, Evan L. Nichols, Lauren A. Green, Cody J. Smith, Sam A. Hedlund, Sanjana Pai, and Nina L. Kikel-Coury
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Nervous system ,General Neuroscience ,Biology ,Spinal cord ,Sensory neuron ,medicine.anatomical_structure ,nervous system ,Invadopodia ,medicine ,Neuron ,Axon ,Growth cone ,Neuroscience ,Filopodia - Abstract
Axons navigate through the embryo to construct a functional nervous system. A missing part of the axon navigation puzzle is how a single axon traverses distinct anatomic choice points through its navigation. The dorsal root ganglia (DRG) neurons experience such choice points. First, they navigate to the dorsal root entry zone (DREZ), then halt navigation in the peripheral nervous system to invade the spinal cord, and then reinitiate navigation inside the CNS. Here, we used time-lapse super-resolution imaging in zebrafish DRG pioneer neurons to investigate how embryonic axons control their cytoskeleton to navigate to and invade at the correct anatomic position. We found that invadopodia components form in the growth cone even during filopodia-based navigation, but only stabilize when the axon is at the spinal cord entry location. Further, we show that intermediate levels of DCC and cAMP, as well as Rac1 activation, subsequently engage an axon invasion brake. Our results indicate that actin-based invadopodia components form in the growth cone and disruption of the invasion brake causes axon entry defects and results in failed behavioral responses, thereby demonstrating the importance of regulating distinct actin populations during navigational challenges.SIGNIFICANCE STATEMENT Correct spatiotemporal navigation of neuronal growth cones is dependent on extracellular navigational cues and growth cone dynamics. Here, we link dcc-mediated signaling to actin-based invadopodia and filopodia dynamics during pathfinding and entry into the spinal cord using an in vivo model of dorsal root ganglia (DRG) sensory axons. We reveal a molecularly-controlled brake on invadopodia stabilization until the sensory neuron growth cone is present at the dorsal root entry zone (DREZ), which is ultimately essential for growth cone entry into the spinal cord and behavioral response.
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- 2021
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11. Mechanisms of severe acute intermittent hypoxia-induced phrenic long-term facilitation
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Nicole L. Nichols and Gordon S. Mitchell
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Male ,medicine.medical_specialty ,Physiology ,Rats, Sprague-Dawley ,03 medical and health sciences ,0302 clinical medicine ,immune system diseases ,Internal medicine ,medicine ,Animals ,Respiratory system ,Hypoxia ,Protein kinase B ,PI3K/AKT/mTOR pathway ,030304 developmental biology ,Motor Neurons ,0303 health sciences ,Neuronal Plasticity ,business.industry ,Long term facilitation ,General Neuroscience ,Intermittent hypoxia ,Motor neuron ,Spinal cord ,digestive system diseases ,Rats ,Phrenic Nerve ,Disease Models, Animal ,medicine.anatomical_structure ,Acute Disease ,Cardiology ,Breathing ,business ,030217 neurology & neurosurgery ,Signal Transduction ,Research Article - Abstract
Moderate acute intermittent hypoxia (mAIH; 35–55 mmHg Pa(O(2))) elicits phrenic long-term facilitation (pLTF) by a mechanism that requires activation of G(q) protein-coupled serotonin type 2 receptors, MEK/ERK MAP kinase, and NADPH oxidase activity and is constrained by cAMP-PKA signaling. In contrast, severe AIH (sAIH; 25–35 mmHg Pa(O(2))) elicits G(s) protein-coupled adenosine type 2 A receptor-dependent pLTF. Another G(s) protein-coupled receptor, serotonin 7 receptors, elicits phrenic motor facilitation (pMF) by a mechanism that requires exchange protein activated by cyclic AMP (EPAC) and phosphatidylinositol 3-kinase/Akt (PI3K/Akt) activation and is constrained by NADPH oxidase activity. Here, we tested the hypothesis that the same downstream signaling mechanisms giving rise to serotonin 7 (vs. serotonin 2) receptor-induced pMF underlie sAIH-induced pLTF. In anesthetized rats, sAIH-induced pLTF was compared after pretreatment with intrathecal (C4) injections of inhibitors for: 1) EPAC (ESI-05); 2) MEK/ERK (UO126); 3) PKA (KT-5720); 4) PI3K/Akt (PI828); and 5) NADPH oxidase (apocynin). In partial agreement with our hypothesis, sAIH-induced pLTF was abolished by ESI-05 and PI828 and marginally enhanced by apocynin but, surprisingly, was abolished by UO126 and attenuated by KT-5720. Mechanisms of sAIH-induced pLTF reflect elements of both G(q) and G(s) pathways to pMF, likely as a consequence of the complex, cross-talk interactions between them. NEW & NOTEWORTHY Distinct mechanisms give rise to pLTF induced by moderate and severe AIH. We demonstrate that, unlike moderate AIH, severe AIH-induced pLTF requires EPAC and PI3K/Akt and is marginally constrained by NADPH oxidase activity. Surprisingly, sAIH-induced pLTF requires MEK/ERK activity similar to moderate AIH-induced pLTF and is reduced by PKA inhibition. We suggest sAIH-induced pLTF arises from complex interactions between dominant mechanisms characteristic of moderate versus severe AIH-induced pLTF.
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- 2021
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12. Ex vivo delivery of Mirococept: A dose-finding study in pig kidney after showing a low dose is insufficient to reduce delayed graft function in human kidney
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Jonathon Olsburgh, Abdel Douiri, Guilherme Danzi, Anass Qasem, Richard A. G. Smith, Theodoros Kassimatis, Clare Flach, Peter J. Friend, Flavia Neri, Steven H. Sacks, James P. Hunter, Laura L. Nichols, Catherine Horsfield, Roseanna Greenlaw, Martin Drage, Irene Rebollo-Mesa, and Julieta Karegli
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medicine.medical_specialty ,translational research/science ,Swine ,Urology ,Delayed Graft Function ,kidney transplantation/nephrology ,030230 surgery ,clinical research/practice ,Kidney ,complement biology ,Pathogenesis ,03 medical and health sciences ,Complement inhibitor ,0302 clinical medicine ,medicine ,Animals ,Humans ,Immunology and Allergy ,Pharmacology (medical) ,Transplantation ,Machine perfusion ,business.industry ,Graft Survival ,animal models: porcine ,Kidney Transplantation ,Tissue Donors ,Complement system ,ischemia reperfusion injury (IRI) ,Complement Inactivating Agents ,medicine.anatomical_structure ,Reperfusion Injury ,business ,Ex vivo - Abstract
The complement system plays a pivotal role in the pathogenesis of ischemia-reperfusion injury in solid organ transplantation. Mirococept is a potent membrane-localizing complement inhibitor that can be administered ex vivo to the donor kidney prior to transplantation. To evaluate the efficacy of Mirococept in reducing delayed graft function (DGF) in deceased donor renal transplantation, we undertook the efficacy of mirococept (APT070) for preventing ischaemia-reperfusion injury in the kidney allograft (EMPIRIKAL) trial (ISRCTN49958194). A dose range of 5-25 mg would be tested, starting with 10 mg in cohort 1. No significant difference between Mirococept at 10 mg and control was detected; hence the study was stopped to enable a further dose saturation study in a porcine kidney model. The optimal dose of Mirococept in pig kidney was 80 mg. This dose did not induce any additional histological damage compared to controls or after a subsequent 3 hours of normothermic machine perfusion. The amount of unbound Mirococept postperfusion was found to be within the systemic dose range considered safe in the Phase I trial. The ex vivo administration of Mirococept is a safe and feasible approach to treat DGF in deceased donor kidney transplantation. The porcine kidney study identified an optimal dose of 80 mg (equivalent to 120 mg in human kidney) that provides a basis for further clinical development.
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- 2021
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13. Combatting the Epidemic of E-cigarette Use and Vaping among Students and Transitional-age Youth
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Abolhassani Hassan, Vezzoli Valeria, S. Childs Gail, Li Hui-Chun, Y. Al-Nema Mayasah, Jadidi-Niaragh Farhad, Morsink Margaretha, R. Moreau Jacquelyn, Zheng Yangmin, Aghamohammadi Asghar, L. Nichols Kathy, Ferreira da Silva Classius, Barbosa Souto Eliana, Cordeiro Cardoso Juliana, Goudarzvand Mahdi, Shirkani Afshin, Campbell Christopher, Duminuco Paolo, J. Merlo Lisa, Uppal Sheetal, Luo Yumin, Hamedifar Haleh, Chen Ke, Azizi Gholamreza, Hafezi Nasim, García Julio, de Celis Alonso Benito, Pogliaghi Gabriele, Kundu Suman, Zhao Haiping, Bonomi Marco, N.T. De Silva Sembukuttige, Han Ziping, Almasi-Hashiani Amir, Zian Zeineb, M. Hernández López Javier, Severino Patrícia, Sabzevari Araz, Dies Suárez Pilar, Cangiano Biagio, Asim Khan Mohd., Aghamahdi Fatemeh, S. Hidalgo Tobón Silvia, Chandra Ojha Suvash, Domenico Lisa, Gaurav Anand, Almeida Taline, G.S. Siri Jothiratna, A.N. Fernando Chakrawarthige, Yazdani Reza, Angsuthanasombat Chanan, Thonabulsombat Charoensri, Zaki-Dizaji Majid, Barragán Pérez Eduardo, de Melo Barbosa Raquel, Imtong Chompounoot, Khine Linn Aung, E. DeRemer Christina, and Kiaee Fatemeh
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Pharmacology ,Psychiatry and Mental health ,business.industry ,Environmental health ,Medicine ,Pharmacology (medical) ,Cigarette use ,business - Abstract
Background: Over the past decade, the use of electronic nicotine delivery system (ENDS) devices such as e-cigarettes has increased dramatically, particularly among students and other transitional- age youth. Societal norms and the variety of ENDS devices available have also evolved dramatically in recent years. Objective: This article provides a comprehensive review and synthesis of contemporary literature, as it relates to ENDS use among transitional-age youth. Methods: Over 125 peer-reviewed studies, literature syntheses, legal reports and contemporary media works focused on ENDS use and vaping were reviewed. Results: Marketing strategies for ENDS devices have primarily targeted teens and young adults. Though ENDS devices are advertised as a safer alternative to cigarettes, accumulating data demonstrate significant health risks and consequences associated with use. The long-term health effects remain largely unknown; however, detrimental acute effects are apparent. Furthermore, rather than aiding in tobacco cessation efforts, the use of ENDS by transitional-age youth is correlated with the increased use of conventional tobacco products and other substances of abuse. Students appear to be ill-informed regarding the dangers of using ENDS products. Conclusion: Given the rapid increase in ENDS users each year, and accumulating concerns about health risks associated with use, university student health services must be prepared to address this growing problem. As clinical practice guidelines do not yet exist to encourage ENDS-product cessation, the use of the evidence-based strategies developed for tobacco cessation is advised. More research is needed to determine the most effective methods to prevent the initiation of ENDS use within this population.
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- 2021
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14. Glucose confers protection to Escherichia coli against contact killing by Vibrio cholerae
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Peter Yunker, Gabi Steinbach, Holly L. Nichols, Cristian V. Crisan, Brian K. Hammer, and Sophia Wiesenfeld
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0301 basic medicine ,Science ,030106 microbiology ,medicine.disease_cause ,Article ,Microbiology ,Microbial ecology ,03 medical and health sciences ,Bacterial Proteins ,Immunity ,Bacterial genetics ,Escherichia coli ,medicine ,Humans ,Vibrio cholerae ,Gene ,Type VI secretion system ,Multidisciplinary ,biology ,Effector ,Bacteriology ,Bacterial Infections ,Gene Expression Regulation, Bacterial ,Type VI Secretion Systems ,biology.organism_classification ,Glucose ,030104 developmental biology ,cAMP receptor protein ,biology.protein ,Medicine ,Bacteria - Abstract
Evolutionary arms races are broadly prevalent among organisms including bacteria, which have evolved defensive strategies against various attackers. A common microbial aggression mechanism is the type VI secretion system (T6SS), a contact-dependent bacterial weapon used to deliver toxic effector proteins into adjacent target cells. Sibling cells constitutively express immunity proteins that neutralize effectors. However, less is known about factors that protect non-sibling bacteria from T6SS attacks independently of cognate immunity proteins. In this study, we observe that human Escherichia coli commensal strains sensitive to T6SS attacks from Vibrio cholerae are protected when co-cultured with glucose. We confirm that glucose does not impair V. cholerae T6SS activity. Instead, we find that cells lacking the cAMP receptor protein (CRP), which regulates expression of hundreds of genes in response to glucose, survive significantly better against V. cholerae T6SS attacks even in the absence of glucose. Finally, we show that the glucose-mediated T6SS protection varies with different targets and killers. Our findings highlight the first example of an extracellular small molecule modulating a genetically controlled response for protection against T6SS attacks. This discovery may have major implications for microbial interactions during pathogen-host colonization and survival of bacteria in environmental communities.
- Published
- 2021
15. Impact of Menopause and Body Composition Status on Dyslipidemia in Women
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Charlotte F. Sanborn, Nancy M. DiMarco, Benjamin L. Webb, David L. Nichols, and Joshua S. Wooten
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Health (social science) ,Social Psychology ,Physiology ,Menstrual status ,Regional body composition ,Body Mass Index ,03 medical and health sciences ,medicine ,Humans ,Obesity ,Triglycerides ,Dyslipidemias ,030505 public health ,business.industry ,Public Health, Environmental and Occupational Health ,Fat distribution ,Overweight ,medicine.disease ,Menopause ,Cholesterol ,Normal weight ,Body Composition ,Female ,lipids (amino acids, peptides, and proteins) ,Composition (visual arts) ,0305 other medical science ,business ,Dyslipidemia - Abstract
Objective: The aim of this study was to identify the effects of menopausal and body composition statuses on measures of total and regional body composition and dyslipidemia in women. Methods: Sedentary, non-smoking women (N = 212), not currently treated for dyslipidemia were grouped based on 2 categories: (1) menstrual status: premenopausal or postmenopausal and (2) body composition status: normal weight (NW; BMI < 25 kg/m2 and body fat (BF) < 36%), normal weight obese (NWO; BMI < 25 kg/m2 and BF > 36%), or obese (BMI > 25 kg/m2 and BF > 36%), to determine differences in total and regional body composition and measures of lipid and lipoprotein-cholesterol concentrations. Results: Overall, a greater prevalence of NWO was observed in postmenopausal versus premenopausal women. Being postmenopausal was associated with higher TC, LDL-C, non-HDL-C, HDL-C, and HDL3-C. Premenopausal NWO women had elevated LDL-C and VLDL-C comparable to obese women. Postmenopausal NWO women had elevated Tg and VLDL-C and lower HDL-C similar to obese women. Conclusions: Menopausal status was not associated with differences in fat distribution, however, the age-related differences in lipids and lipoproteins appear to be due to a difference in menopausal status exacerbated in women who are NWO.
- Published
- 2021
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16. Tongue and hypoglossal morphology after intralingual cholera toxin B <scp>–</scp> saporin injection
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Teresa E. Lever, Lori A Lind, and Nicole L. Nichols
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0301 basic medicine ,Cholera Toxin ,Hypoglossal Nerve ,Pathology ,medicine.medical_specialty ,Saporin ,Physiology ,Muscle Fibers, Skeletal ,030105 genetics & heredity ,medicine.disease_cause ,Injections, Intramuscular ,Article ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Tongue ,Laminin ,Physiology (medical) ,medicine ,Animals ,Motor Neurons ,Neurons ,Genioglossus ,biology ,Cholera toxin ,Organ Size ,Immunohistochemistry ,Saporins ,Dysphagia ,Axons ,Rats ,Disease Models, Animal ,medicine.anatomical_structure ,biology.protein ,Ultrastructure ,Neurology (clinical) ,medicine.symptom ,Deglutition Disorders ,030217 neurology & neurosurgery - Abstract
Introduction We recently developed an inducible model of dysphagia using intralingual injection of cholera toxin B conjugated to saporin (CTB-SAP) to cause death of hypoglossal neurons. In this study we aimed to evaluate tongue morphology and ultrastructural changes in hypoglossal neurons and nerve fibers in this model. Methods Tissues were collected from 20 rats (10 control and 10 CTB-SAP animals) on day 9 post-injection. Tongues were weighed, measured, and analyzed for microscopic changes using laminin immunohistochemistry. Hypoglossal neurons and axons were examined using transmission electron microscopy. Results The cross-sectional area of myofibers in the posterior genioglossus was decreased in CTB-SAP-injected rats. Degenerative changes were observed in both the cell bodies and distal axons of hypoglossal neurons. Discussion Preliminary results indicate this model may have translational application to a variety of neurodegenerative diseases resulting in tongue dysfunction and associated dysphagia.
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- 2020
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17. Maintaining adequate donations and a sustainable blood supply: Lessons learned
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Richard R Gammon, Sarah Vossoughi, Tracie L Nichols, Rhonda Cooke, Lizabeth Rosenbaum, Linda Rockwood, and Mark T. Friedman
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medicine.medical_specialty ,Erythrocytes ,transfusion practices (oncology‐hematology) ,Blood Safety ,media_common.quotation_subject ,Immunology ,Specialty ,Reviews ,Blood Component Transfusion ,Blood Donors ,Disaster Planning ,Review ,030204 cardiovascular system & hematology ,ABO Blood-Group System ,03 medical and health sciences ,0302 clinical medicine ,Resource (project management) ,medicine ,Humans ,Immunology and Allergy ,Operations management ,Cooperative Behavior ,media_common ,Emergency management ,Transfusion Medicine ,business.industry ,transfusion service operations ,Transfusion medicine ,Hematology ,Payment ,Hospitals ,Blood center ,Patient Satisfaction ,blood center operations ,Sustainability ,Female ,Blood supply ,Business ,030215 immunology - Abstract
Background The availability of a safe blood supply is a key component of transfusion medicine. A decade of decreased blood use, decreased payment for products, and a dwindling donor base have placed the sustainability of the US blood supply at risk. Study Design and Methods A literature review was performed for blood center (BC) and hospital disaster management, chronically transfusion‐dependent diseases, and appropriate use of group O‐negative red blood cells (RBCs), and the Choosing Wisely campaign. The aim was to identify current practice and to make recommendations for BC and hospital actions. Results While BCs are better prepared to handle disasters than after the 9/11 attacks, messaging to the public remains difficult, as donors often do not realize that blood transfused during a disaster was likely collected before the event. BCs and transfusion services should participate in drafting disaster response plans. Hospitals should maintain inventories adequate for patients in the event supply is disrupted. Providing specialty products for transfusion‐dependent patients can strain collections, lead to increased use of group O RBCs, and create logistical inventory challenges for hospitals. The AABB Choosing Wisely initiative addresses overuse of blood components to optimally use this precious resource. Group O‐negative RBCs should be transfused only to patients who truly need them. Conclusions Collecting and maintaining a blood supply robust enough to handle disasters and transfusion‐dependent patients in need of specialty products is challenging. Collaboration of all parties should help to optimize resources, ensure appropriate collections, improve patient care, and ultimately result in a robust, sustainable blood supply.
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- 2020
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18. Functional <scp>PPO2</scp> mutations: co‐occurrence in one plant or the same ppo2 allele of herbicide‐resistant <scp> Amaranthus palmeri </scp> in the <scp>US</scp> mid‐south
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Lawrence E. Steckel, Jens Lerchl, Taghi Bararpour, Matheus M. Noguera, Nilda Roma-Burgos, Sophie Zimmermann, Gulab Rangani, James W. Heiser, Michael Betz, Aimone Porri, and Robert L. Nichols
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0106 biological sciences ,Genetics ,Mutation ,Herbicide resistant ,Co-occurrence ,General Medicine ,Biology ,biology.organism_classification ,medicine.disease_cause ,01 natural sciences ,Double mutation ,Amaranthus palmeri ,010602 entomology ,chemistry.chemical_compound ,chemistry ,Insect Science ,Glyphosate ,medicine ,Allele ,Agronomy and Crop Science ,Genotyping ,010606 plant biology & botany - Abstract
BACKGROUND Protoporphyrinogen IX oxidase 2 (PPO2) inhibitors are important for the management of glyphosate- and acetolactate synthase-resistant Palmer amaranth [Amaranthus palmeri (S.) Wats.]. The evolving resistance to PPO inhibitors is of great concern. We surveyed the evolution of resistance to fomesafen in the US Mid-south and determined its correlation with the known functional PPO2 target-site mutations (TSM). RESULTS The 167 accessions analyzed were grouped into five categories, four resistant (147) and one susceptible (20). Arkansas accessions constituted 100% of the susceptible group while the Missouri accessions comprised 60% of the most resistant category. The majority of Mississippi accessions (88%) clustered in the high-survival-high-injury category, manifesting an early-stage resistance evolution. One hundred and fifteen accessions were genotyped for four known TSMs; 74% of accessions carried at least one TSM. The most common single TSM was ΔG210 (18% of accessions) and the predominant double mutation was ΔG210 + G399A (17%). Other mutations are likely less favorable, hence are rare. All TSMs were detected in three accessions. Further examination revealed that 9 and two individuals carried G399A + G210 and G399A + R128G TSM in the same allele, respectively. The existence of these combinations is supported by molecular modeling. CONCLUSIONS Resistance to PPO inhibitors is widespread across the Mid-southern USA. Highly resistant field populations have plants with multiple mutations. G399A is the most prone to co-occur with other ppo2 mutations in the same allele. Mutation at R128 in the configuration of the PPO2 catalytic domain restrains the co-occurrence of R128G with ΔG210, making ΔG210 + G399A the most plausible, tolerable functional mutation combination to co-occur in the same ppo2 allele.
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- 2020
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19. Peripheral-to-central immune communication at the area postrema glial-barrier following bleomycin-induced sterile lung injury in adult rats
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Corey Smith, Thomas E. Dick, David Litvin, Lauren F. Borkowski, Frank J. Jacono, Scott J. Denstaedt, and Nicole L. Nichols
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0301 basic medicine ,medicine.medical_specialty ,Immunology ,Inflammation ,Lung injury ,Article ,Rats, Sprague-Dawley ,Bleomycin ,03 medical and health sciences ,Behavioral Neuroscience ,0302 clinical medicine ,Internal medicine ,Animals ,Medicine ,Neuroinflammation ,Circumventricular organs ,Glial fibrillary acidic protein ,biology ,Endocrine and Autonomic Systems ,business.industry ,Communication ,Area postrema ,Lung Injury ,Rats ,030104 developmental biology ,Endocrinology ,medicine.anatomical_structure ,Area Postrema ,nervous system ,biology.protein ,Brainstem ,medicine.symptom ,business ,Neuroglia ,030217 neurology & neurosurgery ,Homeostasis - Abstract
The pathways for peripheral-to-central immune communication (P → C I-comm) following sterile lung injury (SLI) are unknown. SLI evokes systemic and central inflammation, which alters central respiratory control and viscerosensory transmission in the nucleus tractus solitarii (nTS). These functional changes coincide with increased interleukin-1 beta (IL-1β) in the area postrema, a sensory circumventricular organ that connects P → C I-comm to brainstem circuits that control homeostasis. We hypothesize that IL-1β and its downstream transcriptional target, cyclooxygenase-2 (COX-2), mediate P → C I-comm in the nTS. In a rodent model of SLI induced by intratracheal bleomycin (Bleo), the sigh frequency and duration of post-sigh apnea increased in Bleo- compared to saline- treated rats one week after injury. This SLI-dependent change in respiratory control occurred concurrently with augmented IL-1β and COX-2 immunoreactivity (IR) in the funiculus separans (FS), a barrier between the AP and the brainstem. At this barrier, increases in IL-1β and COX-2 IR were confined to processes that stained for glial fibrillary acidic protein (GFAP) and that projected basolaterally to the nTS. Further, FS radial-glia did not express TNF-α or IL-6 following SLI. To test our hypothesis, we blocked central COX-1/2 activity by intracerebroventricular (ICV) infusion of Indomethacin (Ind). Continuous ICV Ind treatment prevented Bleo-dependent increases in GFAP + and IL-1β + IR, and restored characteristics of sighs that reset the rhythm. These data indicate that changes in sighs following SLI depend partially on activation of a central COX-dependent P → C I-comm via radial-glia of the FS.
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- 2020
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20. Hemostatic prophylaxis and colonoscopy outcomes for patients with bleeding disorders: A retrospective cohort study and review of the literature
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C. Christopher Hook, Rajiv K. Pruthi, Amy Eckerman, Sarah M. Azer, William L. Nichols, Aneel A. Ashrani, Vilmarie Rodriguez, and Ariela L. Marshall
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Adult ,Male ,medicine.medical_specialty ,Psychological intervention ,haemophilia ,Colonoscopy ,Hemorrhage ,030204 cardiovascular system & hematology ,Haemophilia ,Hemostatics ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Von Willebrand disease ,Humans ,Clinical Haemophilia ,Genetics (clinical) ,Aged ,Retrospective Studies ,medicine.diagnostic_test ,business.industry ,Retrospective cohort study ,Original Articles ,Hematology ,General Medicine ,Middle Aged ,medicine.disease ,Exact test ,Treatment Outcome ,Hemostasis ,Cohort ,Original Article ,Female ,prophylaxis ,von Willebrand disease ,business ,030215 immunology - Abstract
Introduction Hemostatic prophylaxis (HP) is recommended for patients with bleeding disorders (PWBD) before invasive procedures. However, evidence‐based guidelines are needed to determine optimal HP strategies. Aim To determine outcomes of HP for PWBD undergoing colonoscopy. Methods We undertook a retrospective cohort study of HP and outcomes of colonoscopy procedures performed between 9 November 1993 and 13 February 2018 for PWBD who received care in the Mayo Clinic Comprehensive Hemophilia Treatment Center. Results During the study period, 73 PWBD (58 with milder phenotypes: haemophilia, von Willebrand disease [subtypes 1 and 2; II, VII and XI deficiency]) underwent 141 procedures. Preprocedural HP was given to 61%, and interventions were performed in 47%. Of the 39% without preprocedural HP, postprocedural HP was given for 11%. One major (0.7%; 6 days postprocedure despite HP) and 10 minor (7%) bleeding complications occurred, which tended to be in patients with severe disease and/or after excision of larger polyps. There was no significant difference in the rate of bleeding complications with or without preprocedural HP (8.1% vs 5.5%, respectively; P = .74, Fisher's exact test). Conclusion The low bleeding rates in our cohort suggest that preprocedure HP may be withheld for patients with mild bleeding disorders who undergo colonoscopy with a low likelihood of requiring an intervention or who require only low‐risk intervention. This strategy may be best used in experienced centres, provided optimal local hemostasis measures are undertaken and postprocedural HP is rapidly available if high‐risk intervention is required. Further studies are needed to determine optimal evidence‐based HP strategies for PWBD undergoing colonoscopy.
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- 2020
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21. Routine disaccharidase testing: are we there yet?
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Bruno P. Chumpitazi, Mustafa M. Abdulsada, Antone R. Opekun, and Buford L. Nichols
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Abdominal discomfort ,Enzyme supplementation ,medicine.diagnostic_test ,Gastrointestinal Diseases ,Mechanism (biology) ,business.industry ,Gastroenterology ,Disaccharidases ,Bioinformatics ,Article ,Disaccharidase ,Gastrointestinal Microbiome ,Patient management ,03 medical and health sciences ,0302 clinical medicine ,Breath testing ,Malabsorption Syndromes ,030220 oncology & carcinogenesis ,Fermentation ,Humans ,Medicine ,030211 gastroenterology & hepatology ,Microbiome ,business ,Genetic testing - Abstract
Purpose of review Disaccharidase testing, as applied to the evaluation of gastrointestinal disturbances is available but it is not routinely considered in the diagnostic work-up. The purpose of this review was to determine if disaccharidase testing is clinically useful and to consider how the results could alter patient management. Recent findings Indicate that carbohydrate maldigestion could contribute functional bowel disorders and negatively impact the fecal microbiome. Diagnostic techniques include enzyme activity assays performed on random endoscopically obtained small intestinal biopsies, immunohistochemistry, stable isotope tracer and nonenriched substrate load breath testing, and genetic testing for mutations. More than 40 sucrase--isomaltase gene variants coding for defective or reduced enzymatic activity have been reported and deficiency conditions are more common than previously thought. Summary The rationale for disaccharidase activity testing relates to a need to fully assess unexplained recurrent abdominal discomfort and associated symptoms. All disaccharidases share the same basic mechanism of mucosal expression and deficiency has far reaching consequences. Testing for disaccharidase expression appears to have an important role in symptom evaluation, but there are accuracy and logistical issues that should be considered. It is likely that specific recommendations for patient management, dietary modification, and enzyme supplementation would come from better testing methods.
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- 2020
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22. Fluorescence activation mechanism and imaging of drug permeation with new sensors for smoking-cessation ligands
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Laura Luebbert, Chengcheng Fan, Zack Blumenfeld, Aaron L Nichols, Annet EM Blom, Bruce N Cohen, Jonathan S Marvin, Philip M Borden, Charlene H Kim, Anand K Muthusamy, Amol V Shivange, Hailey J Knox, Hugo Rego Campello, Jonathan H Wang, Dennis A Dougherty, Loren L Looger, Timothy Gallagher, Douglas C Rees, and Henry A Lester
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Mouse ,iDrugSnFRs ,QH301-705.5 ,Science ,inside-out pharmacology ,Ligands ,Heterocyclic Compounds, 4 or More Rings ,Fluorescence ,General Biochemistry, Genetics and Molecular Biology ,neuroscience ,Substance Misuse ,Mice ,Alkaloids ,Heterocyclic Compounds ,Tobacco ,Animals ,Humans ,Nicotinic Agonists ,Biology (General) ,Cancer ,Tobacco Smoke and Health ,General Immunology and Microbiology ,General Neuroscience ,Neurosciences ,Azepines ,General Medicine ,4 or More Rings ,biosensors ,Azocines ,Brain Disorders ,Good Health and Well Being ,nicotinic agonists ,Medicine ,Smoking Cessation ,Generic health relevance ,Biochemistry and Cell Biology ,Drug Abuse (NIDA only) ,pharmacokinetics ,Quinolizines ,nicotine - Abstract
Nicotinic partial agonists provide an accepted aid for smoking cessation and thus contribute to decreasing tobacco-related disease. Improved drugs constitute a continued area of study. However, there remains no reductionist method to examine the cellular and subcellular pharmacokinetic properties of these compounds in living cells. Here, we developed new intensity-based drug-sensing fluorescent reporters (iDrugSnFRs) for the nicotinic partial agonists dianicline, cytisine, and two cytisine derivatives – 10-fluorocytisine and 9-bromo-10-ethylcytisine. We report the first atomic-scale structures of liganded periplasmic binding protein-based biosensors, accelerating development of iDrugSnFRs and also explaining the activation mechanism. The nicotinic iDrugSnFRs detect their drug partners in solution, as well as at the plasma membrane (PM) and in the endoplasmic reticulum (ER) of cell lines and mouse hippocampal neurons. At the PM, the speed of solution changes limits the growth and decay rates of the fluorescence response in almost all cases. In contrast, we found that rates of membrane crossing differ among these nicotinic drugs by >30-fold. The new nicotinic iDrugSnFRs provide insight into the real-time pharmacokinetic properties of nicotinic agonists and provide a methodology whereby iDrugSnFRs can inform both pharmaceutical neuroscience and addiction neuroscience.
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- 2022
23. Dexmedetomidine prolongs the duration of action of mepivacaine on anesthesia of the palmar digital nerves of horses
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Cailey L. Nichols, Xiaocun Sun, Philip D. Jones, James Schumacher, and Thomas J Doherty
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Heel ,General Veterinary ,business.industry ,Sedation ,Mepivacaine ,Horse ,Nerve Block ,General Medicine ,Blockade ,medicine.anatomical_structure ,Nociception ,Lameness ,Anesthesia ,Forelimb ,Medicine ,Animals ,Female ,Horses ,medicine.symptom ,Dexmedetomidine ,Anesthetics, Local ,business ,medicine.drug - Abstract
OBJECTIVE To determine whether palmar digital nerve (PDN) blockade in horses with a combination of dexmedetomidine and mepivacaine would block the response to mechanical force applied to the digit longer than would anesthetizing these nerves with mepivacaine alone or dexmedetomidine alone. ANIMALS 8 mares with no signs of lameness. PROCEDURES In a randomized, crossover, blinded, experimental study, both PDNs of the same forelimb of each horse were anesthetized by perineural injection with either 30 mg mepivacaine alone, 250 µg of dexmedetomidine alone, or 30 mg mepivacaine combined with 250 µg of dexmedetomidine. Each horse received each treatment, and treatments were administered ≥ 2 weeks apart. The mechanical nociceptive threshold was measured at a region between the heel bulbs with the use of a digital force gauge before (baseline) and at 15-minute intervals after treatment. RESULTS The mean duration of sensory blockade of the digit was 2-fold longer when a combination of mepivacaine and dexmedetomidine was administered (371 minutes), compared with when mepivacaine alone was administered (186 minutes). Treatment with dexmedetomidine alone did not change the mechanical nociceptive threshold substantially from baseline and resulted in no clinical signs of sedation. CLINICAL RELEVANCE Results indicated that relief from digital pain provided by perineural treatment with mepivacaine for PDN blockade can be extended by adding dexmedetomidine to the injectate.
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- 2021
24. Fluorescence Activation Mechanism and Imaging of Drug Permeation with New Sensors for Smoking-Cessation Ligands
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Jonathan S. Marvin, Amol V. Shivange, Hailey J. Knox, Loren L. Looger, Henry A. Lester, Charlene H. Kim, Annet E. M. Blom, C. Fan, Timothy Gallagher, Laura Luebbert, Philip M. Borden, Bruce N. Cohen, Aaron L. Nichols, Hugo Rego Campello, Dennis A. Dougherty, Jonathan H. Wang, Zack Blumenfeld, Douglas C. Rees, and Anand K. Muthusamy
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Drug ,Dianicline ,Endoplasmic reticulum ,media_common.quotation_subject ,Partial agonist ,Nicotine ,chemistry.chemical_compound ,Cytisine ,Nicotinic agonist ,chemistry ,medicine ,Biophysics ,Varenicline ,medicine.drug ,media_common - Abstract
Nicotinic partial agonists provide an accepted aid for smoking cessation and thus contribute to decreasing tobacco-related disease. Improved drugs constitute a continued area of study. However, there remains no reductionist method to examine the cellular and subcellular pharmacokinetic properties of these compounds in living cells. Here, we developed new intensity-based drug sensing fluorescent reporters ("iDrugSnFRs") for the nicotinic partial agonists dianicline, cytisine, and two cytisine derivatives - 10-fluorocytisine and 9-bromo-10-ethylcytisine. We report the first atomic-scale structures of liganded periplasmic binding protein-based biosensors, accelerating development of iDrugSnFRs and also explaining the activation mechanism. The nicotinic iDrugSnFRs detect their drug partners in solution, as well as at the plasma membrane (PM) and in the endoplasmic reticulum (ER) of cell lines and mouse hippocampal neurons. At the PM, the speed of solution changes limits the growth and decay rates of the fluorescence response in almost all cases. In contrast, we found that rates of membrane crossing differ among these nicotinic drugs by > 30 fold. The new nicotinic iDrugSnFRs, in combination with previously described nicotine and varenicline sensors, provide insight into the real-time pharmacokinetic properties of nicotinic agonists and provide a methodology whereby iDrugSnFRs can inform both pharmaceutical neuroscience and addiction neuroscience.
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- 2021
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25. Fly Transmission of Campylobacter
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Gordon L. Nichols
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Campylobacter ,Climate ,diarrhea ,disease outbreaks ,Epidemiologic Methods ,Diptera ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Published
- 2005
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26. Cardiology providers’ recommendations for treatments and use of patient decision aids for multivessel coronary artery disease
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Daniel D. Matlock, Elizabeth L. Nichols, David J. Malenka, Mandeep S. Sidhu, A. James O'Malley, Megan Coylewright, Anthony W. DiScipio, Shama S. Alam, Glyn Elwyn, Cathy S. Ross, and Jeremiah R. Brown
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Adult ,Male ,medicine.medical_specialty ,Consensus ,Adolescent ,Health Status ,medicine.medical_treatment ,Clinical Decision-Making ,Specialty ,MEDLINE ,Nurses ,Coronary Artery Disease ,Choice Behavior ,Decision Support Techniques ,Coronary artery disease ,Young Adult ,Cardiologists ,Percutaneous Coronary Intervention ,New England ,Diseases of the circulatory (Cardiovascular) system ,Humans ,Medicine ,cardiovascular diseases ,Coronary Artery Bypass ,Practice Patterns, Physicians' ,Aged ,Angiology ,Aged, 80 and over ,Surgeons ,business.industry ,Research ,Patient Selection ,Percutaneous coronary intervention ,Middle Aged ,medicine.disease ,Cardiac surgery ,Cross-Sectional Studies ,surgical procedures, operative ,Vignette ,RC666-701 ,Health Care Surveys ,Emergency medicine ,Conventional PCI ,Female ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Rates of recommending percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) vary across clinicians. Whether clinicians agree on preferred treatment options for multivessel coronary artery disease patients has not been well studied. Methods and results We distributed a survey to 104 clinicians from the Northern New England Cardiovascular Study Group through email and at a regional meeting with 88 (84.6%) responses. The survey described three clinical vignettes of multivessel coronary artery disease patients. For each patient vignette participants selected appropriate treatment options and whether they would use a patient decision aid. The likelihood of choosing PCI only or PCI/CABG over CABG only was modeled using a multinomial regression. Across all vignettes, participants selected CABG only as an appropriate treatment option 24.2% of the time, PCI only 25.4% of the time, and both CABG or PCI as appropriate treatment options 50.4% of the time. Surgeons were less likely to choose PCI over CABG (RR 0.14, 95% CI 0.03, 0.59) or both treatments over CABG only (RR 0.10, 95% CI 0.03, 0.34) relative to cardiologists. Overall, 65% of participants responded they would use a patient decision aid with each vignette. Conclusions There is a lack of consensus on the appropriate treatment options across cardiologists and surgeons for patients with multivessel coronary artery disease. Treatment choice is influenced by both patient characteristics and clinician specialty.
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- 2021
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27. Divergent receptor utilization is necessary for phrenic long-term facilitation over the course of motor neuron loss following CTB-SAP intrapleural injections
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Lauren F. Borkowski, Nicole L. Nichols, Amy N Keilholz, and Catherine L Smith
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Male ,Cholera Toxin ,Receptor, Adenosine A2A ,Physiology ,Long-Term Potentiation ,030204 cardiovascular system & hematology ,complex mixtures ,Rats, Sprague-Dawley ,03 medical and health sciences ,Phosphatidylinositol 3-Kinases ,0302 clinical medicine ,Medicine ,Animals ,Receptor, trkB ,Respiratory system ,Receptor ,Extracellular Signal-Regulated MAP Kinases ,Motor Neurons ,Long term facilitation ,business.industry ,General Neuroscience ,Brain-Derived Neurotrophic Factor ,Respiration ,Motor neuron ,Spinal cord ,Saporins ,Rats ,Phrenic Nerve ,medicine.anatomical_structure ,Receptors, Serotonin ,Synapses ,Facilitation ,Breathing ,business ,Neuroscience ,Proto-Oncogene Proteins c-akt ,030217 neurology & neurosurgery ,Research Article - Abstract
Intrapleural injection of cholera toxin B conjugated to saporin (CTB-SAP) mimics respiratory motor neuron death and respiratory deficits observed in rat models of neuromuscular diseases. Seven-day CTB-SAP rats elicit enhanced phrenic long-term facilitation (pLTF) primarily through TrkB and PI3K/Akt-dependent mechanisms [i.e., Gs-pathway, which can be initiated by adenosine 2A (A2A) receptors in naïve rats], whereas 28-day CTB-SAP rats elicit moderate pLTF though BDNF- and MEK-/ERK-dependent mechanisms [i.e., Gq-pathway, which is typically initiated by serotonin (5-HT) receptors in naïve rats]. Here, we tested the hypothesis that pLTF following CTB-SAP is 1) A2A receptor-dependent at 7 days and 2) 5-HT receptor-dependent at 28 days. Adult Sprague–Dawley male rats were anesthetized, paralyzed, ventilated, and exposed to acute intermittent hypoxia (AIH; 3-, 5-min bouts of 10.5% O(2)) following bilateral, intrapleural injections at 7 days and 28 days of 1) CTB-SAP (25 µg) or 2) unconjugated CTB and SAP (control). Intrathecal C(4) delivery included either the 1) A2A receptor antagonist (MSX-3; 10 µM; 12 µL) or 2) 5-HT receptor antagonist (methysergide; 20 mM; 15 µL). pLTF was abolished with A2A receptor inhibition in 7-day, not 28-day, CTB-SAP rats versus controls (P < 0.05), whereas pLTF was abolished following 5-HT receptor inhibition in 28-day, not 7-day, CTB-SAP rats versus controls (P < 0.05). In addition, 5-HT2A receptor expression was unchanged in CTB-SAP rats versus controls, whereas 5-HT2B receptor expression was decreased in CTB-SAP rats versus controls (P < 0.05). This study furthers our understanding of the contribution of differential receptor activation to pLTF and its implications for breathing following respiratory motor neuron death. NEW & NOTEWORTHY The current study investigates underlying receptor-dependent mechanisms contributing to phrenic long-term facilitation (pLTF) following CTB-SAP-induced respiratory motor neuron death at 7 days and 28 days. We found that A2A receptors are required for enhanced pLTF in 7-day CTB-SAP rats, whereas 5-HT receptors are required for moderate pLTF in 28-day CTB-SAP rats. Targeting these time-dependent mechanisms have implications for breathing maintenance over the course of many neuromuscular diseases.
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- 2021
28. Injury risk-factor differences between two golf swing styles: a biomechanical analysis of the lumbar spine, hip and knee
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David L. Nichols, George J. Salem, Jordan Cannon, Mark D. Mann, and Kiran D Kanwar
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musculoskeletal diseases ,medicine.medical_specialty ,Knee extensors ,business.industry ,Physical Therapy, Sports Therapy and Rehabilitation ,Swing ,musculoskeletal system ,Low back pain ,Sagittal plane ,Physical medicine and rehabilitation ,medicine.anatomical_structure ,Coronal plane ,medicine ,Injury risk ,Orthopedics and Sports Medicine ,Lumbar spine ,medicine.symptom ,Lead (electronics) ,business ,human activities - Abstract
The golf swing has been associated with mechanical injury risk factors at many joints. One swing, the Minimalist Golf Swing, was hypothesised to reduce lumbar spine, lead hip, and lead knee ranges of motion and peak net joint moments, while affecting swing performance, compared to golfers' existing swings. Existing and MGS swings of 15 golfers with handicaps ranging from +2 to -20 were compared. During MGS downswing, golfers had 18.3% less lumbar spine transverse plane ROM, 40.7 and 41.8% less lead hip sagittal and frontal plane ROM, and 39.2% less lead knee sagittal plane ROM. MGS reduced lead hip extensor, abductor, and internal rotator moments by 17.8, 19.7 and 43%, while lead knee extensor, abductor, adductor and external rotator moments were reduced by 24.1, 26.6, 37 and 68.8% respectively. With MGS, club approach was 2° shallower, path 4° more in-to-out and speed 2 m/s slower. MGS reduced certain joint ROM and moments that are linked to injury risk factors, while influencing club impact factors with varying effect. Most golf injuries are from overuse, so reduced loads per cycle with MGS may extend the healthy life of joints, and permit golfers to play injury-free for more years.
- Published
- 2021
29. Recurrent laryngeal nerve transection in mice results in translational upper airway dysfunction
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Henok G. Woldu, Filiz Bunyak, Michelle R. Ciucci, Megan M Haney, Ali Hamad, Nicole L. Nichols, and Teresa E. Lever
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Male ,0301 basic medicine ,Vocal Cords ,Biology ,Article ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Swallowing ,Paralysis ,medicine ,Recurrent laryngeal nerve ,Animals ,Respiratory function ,Peak flow meter ,measurement_unit ,Nucleus ambiguus ,Laryngoscopy ,Recurrent Laryngeal Nerve ,General Neuroscience ,Deglutition ,Mice, Inbred C57BL ,030104 developmental biology ,Anesthesia ,Recurrent Laryngeal Nerve Injuries ,measurement_unit.measuring_instrument ,Animal studies ,Vocalization, Animal ,medicine.symptom ,Airway ,Vocal Cord Paralysis ,030217 neurology & neurosurgery ,Brain Stem - Abstract
The recurrent laryngeal nerve (RLN) is responsible for normal vocal-fold (VF) movement, and is at risk for iatrogenic injury during anterior neck surgical procedures in human patients. Injury, resulting in VF paralysis, may contribute to subsequent swallowing, voice, and respiratory dysfunction. Unfortunately, treatment for RLN injury does little to restore physiologic function of the VFs. Thus, we sought to create a mouse model with translational functional outcomes to further investigate RLN regeneration and potential therapeutic interventions. To do so, we performed ventral neck surgery in 21 C57BL/6J male mice, divided into two groups: Unilateral RLN Transection (n = 11) and Sham Injury (n = 10). Mice underwent behavioral assays to determine upper airway function at multiple time points prior to and following surgery. Transoral endoscopy, videofluoroscopy, ultrasonic vocalizations, and whole-body plethysmography were used to assess VF motion, swallow function, vocal function, and respiratory function, respectively. Affected outcome metrics, such as VF motion correlation, intervocalization interval, and peak inspiratory flow were identified to increase the translational potential of this model. Additionally, immunohistochemistry was used to investigate neuronal cell death in the nucleus ambiguus. Results revealed that RLN transection created ipsilateral VF paralysis that did not recover by 13 weeks postsurgery. Furthermore, there was evidence of significant vocal and respiratory dysfunction in the RLN transection group, but not the sham injury group. No significant differences in swallow function or neuronal cell death were found between the two groups. In conclusion, our mouse model of RLN injury provides several novel functional outcome measures to increase the translational potential of findings in preclinical animal studies. We will use this model and behavioral assays to assess various treatment options in future studies.
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- 2019
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30. Optimizing the Translational Value of Mouse Models of ALS for Dysphagia Therapeutic Discovery
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Sabrina Kohlberg, Alexis Mok, Andries Ferreira, Joan R. Coates, Kate L Osman, Katelyn McCormack, Elizabeth A. Bearce, Matan D. Kadosh, Mary K. Fagan, Teresa E. Lever, Nicole L. Nichols, Lori A Lind, and Ryan T. Brooks
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Male ,Genetically modified mouse ,Hypoglossal Nerve ,Pathology ,medicine.medical_specialty ,Hypoglossal nucleus ,animal diseases ,SOD1 ,Gene Dosage ,Mice, Transgenic ,Hindlimb ,Article ,Translational Research, Biomedical ,Mice ,Speech and Hearing ,Superoxide Dismutase-1 ,Tongue ,Forelimb ,Paralysis ,medicine ,Animals ,Humans ,Amyotrophic lateral sclerosis ,Gastrointestinal Transit ,business.industry ,Cineradiography ,Amyotrophic Lateral Sclerosis ,Gastroenterology ,nutritional and metabolic diseases ,medicine.disease ,Dysphagia ,Deglutition ,nervous system diseases ,Disease Models, Animal ,medicine.anatomical_structure ,Otorhinolaryngology ,Pharynx ,Female ,Autopsy ,medicine.symptom ,Deglutition Disorders ,business - Abstract
The goal of this study was to compare dysphagia phenotypes in low and high copy number (LCN and HCN) transgenic superoxide dismutase 1 (SOD1) mouse models of ALS to accelerate the discovery of novel and effective treatments for dysphagia and early amyotrophic lateral sclerosis (ALS) diagnosis. Clinicopathological features of dysphagia were characterized in individual transgenic mice and age-matched controls utilizing videofluoroscopy in conjunction with postmortem assays of the tongue and hypoglossal nucleus. Quantitative PCR accurately differentiated HCN-SOD1 and LCN-SOD1 mice and nontransgenic controls. All HCN-SOD1 mice developed stereotypical paralysis in both hindlimbs. In contrast, LCN-SOD1 mice displayed wide variability in fore- and hindlimb involvement. Lick rate, swallow rate, inter-swallow interval, and pharyngeal transit time were significantly altered in both HCN-SOD1 and LCN-SOD1 mice compared to controls. Tongue weight, tongue dorsum surface area, total tongue length, and caudal tongue length were significantly reduced only in the LCN-SOD1 mice compared to age-matched controls. LCN-SOD1 mice with lower body weights had smaller/lighter weight tongues, and those with forelimb paralysis and slower lick rates died at a younger age. LCN-SOD1 mice had a 32% loss of hypoglossal neurons, which differed significantly when compared to age-matched control mice. These novel findings for LCN-SOD1 mice are congruent with reported dysphagia and associated tongue atrophy and hypoglossal nucleus pathology in human ALS patients, thus highlighting the translational potential of this mouse model in ALS research.
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- 2019
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31. A systematic review of cardiovascular responses associated with ambient black carbon and fine particulate matter
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Adam F. Benson, Jennifer L. Nichols, Jason D. Sacks, Ellen Kirrane, Thomas J. Luben, Elizabeth Oesterling Owens, Steven J. Dutton, and Meagan Madden
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Fine particulate matter ,Databases, Factual ,010504 meteorology & atmospheric sciences ,Fine particulate ,Cardiovascular health ,Blood Pressure ,Context (language use) ,010501 environmental sciences ,complex mixtures ,Cardiovascular System ,01 natural sciences ,Article ,Black carbon ,Heart Rate ,Environmental health ,Humans ,Medicine ,Heart rate variability ,Internal validity ,lcsh:Environmental sciences ,0105 earth and related environmental sciences ,General Environmental Science ,lcsh:GE1-350 ,business.industry ,Confounding ,Cardiovascular effects ,Carbon ,Confidence interval ,Ambient air ,Particulate Matter ,business - Abstract
Background: Exposure to fine particulate matter (PM2.5), an ambient air pollutant with mass-based standards promulgated under the Clean Air Act, and black carbon (BC), a common component of PM2.5, are both associated with cardiovascular health effects. Objectives: To elucidate whether BC is associated with distinct, or stronger, cardiovascular responses compared to PM2.5, we conducted a systematic review. We evaluated the associations of short- and long-term BC, or the related component elemental carbon (EC), with cardiovascular endpoints including heart rate variability, heart rhythm, blood pressure and vascular function, ST segment depression, repolarization abnormalities, atherosclerosis and heart function, in the context of what is already known about PM2.5. Data sources: We conducted a stepwise systematic literature search of the PubMed, Web of Science and TOXLINE databases and applied Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines for reporting our results. Study eligibility criteria: Studies reporting effect estimates for the association of quantitative measurements of ambient BC (or EC) and PM2.5, with relevant cardiovascular endpoints (i.e. meeting inclusion criteria) were included in the review. Included studies were evaluated for risk of bias in study design and results. Study appraisal and synthesis methods: Risk of bias evaluations assessed aspects of internal validity of study findings based on study design, conduct, and reporting to identify potential issues related to confounding or other biases. Study results are presented to facilitate comparison of the consistency of associations with PM2.5 and BC within and across studies. Results: Our results demonstrate similar associations for BC (or EC) and PM2.5 with the cardiovascular endpoints examined. Across studies, associations for BC and PM2.5 varied in their magnitude and precision, and confidence intervals were generally overlapping within studies. Where differences in the magnitude of the association between BC or EC and PM2.5 within a study could be discerned, no consistent pattern across the studies examined was apparent. Limitations: We were unable to assess the independence of the effect of BC, relative the effect of PM2.5, on the cardiovascular system, nor was information available to understand the impact of differential exposure misclassification. Conclusions: Overall, the evidence indicates that both BC (or EC) and PM2.5 are associated with cardiovascular effects but the available evidence is not sufficient to distinguish the effect of BC (or EC) from that of PM2.5 mass. Keywords: Black carbon, Fine particulate matter, Cardiovascular effects
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- 2019
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32. The Role of Pharmacy Refill Measures in Assessing Adherence and Predicting HIV Disease Markers in Youth with Perinatally-Acquired HIV (PHIV)
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Cenk, Yildirim, Patricia A, Garvie, Miriam, Chernoff, Megan L, Wilkins, E Doyle, Patton, Paige L, Williams, Sharon L, Nichols, and Elizabeth, Willen
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Social Psychology ,Disease Response ,Anti-HIV Agents ,Human immunodeficiency virus (HIV) ,HIV Infections ,medicine.disease_cause ,Logistic regression ,Article ,Medication Adherence ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Antiretroviral Therapy, Highly Active ,Internal medicine ,medicine ,Humans ,030212 general & internal medicine ,Pharmacy refill ,Pharmacies ,030505 public health ,Recall ,business.industry ,Public health ,Public Health, Environmental and Occupational Health ,Patient Acceptance of Health Care ,Viral Load ,Infectious Disease Transmission, Vertical ,Health psychology ,Outcome and Process Assessment, Health Care ,Infectious Diseases ,Pharmaceutical Services ,HIV-1 ,Female ,Self Report ,0305 other medical science ,business ,Viral load - Abstract
Antiretroviral (ARV) adherence is critical in monitoring disease response in youth with perinatally-acquired HIV (PHIV). We used pharmacy refill (PR) information for PHIV youth from the PHACS Memory Sub-study to calculate medication availability over 2, 4, and 6 months. PR, a proxy of adherence, was compared with self-reported 7-day adherence in predicting suppressed viral load (SVL
- Published
- 2019
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33. Determining the pharmacokinetics of nicotinic drugs in the endoplasmic reticulum using biosensors
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Philip M. Borden, Kallol Bera, Huan Bao, Bruce N. Cohen, Edwin R. Chapman, Ishak Bishara, Anand K. Muthusamy, Aaron L. Nichols, Jonathan S. Marvin, Amol V. Shivange, Loren L. Looger, Dennis A. Dougherty, Matthew J. Mulcahy, Charlene Kim, Janice Jeon, Saidhbhe L. O'Riordan, and Henry A. Lester
- Subjects
Nicotine ,Physiology ,medicine.medical_treatment ,Biosensing Techniques ,Receptors, Nicotinic ,Pharmacology ,Endoplasmic Reticulum ,Hippocampus ,Cell Line ,Green fluorescent protein ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Pregnancy ,Cell Line, Tumor ,Commentaries ,medicine ,Animals ,Humans ,Receptor ,Varenicline ,030304 developmental biology ,Mammals ,Neurons ,0303 health sciences ,Chemistry ,Endoplasmic reticulum ,Cell Membrane ,Smoking ,HEK 293 cells ,3. Good health ,Protein Transport ,HEK293 Cells ,Nicotinic agonist ,Commentary ,Smoking cessation ,Female ,030217 neurology & neurosurgery ,HeLa Cells ,medicine.drug - Abstract
Nicotine dependence is thought to arise in part because nicotine permeates into the endoplasmic reticulum (ER), where it binds to nicotinic receptors (nAChRs) and begins an “inside-out” pathway that leads to up-regulation of nAChRs on the plasma membrane. However, the dynamics of nicotine entry into the ER are unquantified. Here, we develop a family of genetically encoded fluorescent biosensors for nicotine, termed iNicSnFRs. The iNicSnFRs are fusions between two proteins: a circularly permutated GFP and a periplasmic choline-/betaine-binding protein engineered to bind nicotine. The biosensors iNicSnFR3a and iNicSnFR3b respond to nicotine by increasing fluorescence at [nicotine] 75%. Reducing nicotine intake by 10-fold decreases activation to ∼20%. iNicSnFR3a and iNicSnFR3b also sense the smoking cessation drug varenicline, revealing that varenicline also permeates into the ER within seconds. Our iNicSnFRs enable optical subcellular pharmacokinetics for nicotine and varenicline during an early event in the inside-out pathway.
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- 2019
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34. 'The Clock Is Ticking': The Timely Management of a Painful Skin Rash in a Seventy-Year-Old Woman
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Susan Thomas, Folashade Omole, Vijaykumar G. Patel, and Michelle L. Nichols
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Medicine - Abstract
Necrotizing fasciitis is an uncommon but a potentially fatal condition and can affect any part of the body. Most patients have pre-existing conditions that render them susceptible to infection, although etiology is unclear. Diagnosis is primarily clinical and is often delayed because of the unfamiliarity of the condition among clinicians. Management consists of immediate resuscitation, early surgical debridement, and administration of broad spectrum intravenous antibiotics. We report a case of a 70 year old woman who presented with a painful erythematous rash, was admitted as a case of cellulitis, later developed worsening of symptoms and septic shock, and was diagnosed as necrotizing fasciitis.
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- 2014
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35. Substance P differentially modulates firing rate of solitary complex (SC) neurons from control and chronic hypoxia-adapted adult rats.
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Nicole L Nichols, Frank L Powell, Jay B Dean, and Robert W Putnam
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Medicine ,Science - Abstract
NK1 receptors, which bind substance P, are present in the majority of brainstem regions that contain CO2/H(+)-sensitive neurons that play a role in central chemosensitivity. However, the effect of substance P on the chemosensitive response of neurons from these regions has not been studied. Hypoxia increases substance P release from peripheral afferents that terminate in the caudal nucleus tractus solitarius (NTS). Here we studied the effect of substance P on the chemosensitive responses of solitary complex (SC: NTS and dorsal motor nucleus) neurons from control and chronic hypoxia-adapted (CHx) adult rats. We simultaneously measured intracellular pH and electrical responses to hypercapnic acidosis in SC neurons from control and CHx adult rats using the blind whole cell patch clamp technique and fluorescence imaging microscopy. Substance P significantly increased the basal firing rate in SC neurons from control and CHx rats, although the increase was smaller in CHx rats. However, substance P did not affect the chemosensitive response of SC neurons from either group of rats. In conclusion, we found that substance P plays a role in modulating the basal firing rate of SC neurons but the magnitude of the effect is smaller for SC neurons from CHx adult rats, implying that NK1 receptors may be down regulated in CHx adult rats. Substance P does not appear to play a role in modulating the firing rate response to hypercapnic acidosis of SC neurons from either control or CHx adult rats.
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- 2014
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36. Self-reported stomach upset in travellers on cruise-based and land-based package holidays.
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Naomi J Launders, Gordon L Nichols, Rodney Cartwright, Joanne Lawrence, Jane Jones, and Christos Hadjichristodoulou
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Medicine ,Science - Abstract
BACKGROUND: International travellers are at a risk of infectious diseases not seen in their home country. Stomach upsets are common in travellers, including on cruise ships. This study compares the incidence of stomach upsets on land- and cruise-based holidays. METHODS: A major British tour operator has administered a Customer Satisfaction Questionnaire (CSQ) to UK resident travellers aged 16 or more on return flights from their holiday abroad over many years. Data extracted from the CSQ was used to measure self-reported stomach upset in returning travellers. RESULTS: From summer 2000 through winter 2008, 6,863,092 questionnaires were completed; 6.6% were from cruise passengers. A higher percentage of land-based holiday-makers (7.2%) reported stomach upset in comparison to 4.8% of cruise passengers (RR = 1.5, p
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- 2014
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37. Nested Polymerase Chain Reaction for Amplification of the Cryptosporidium Oocyst Wall Protein Gene
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Susana Pedraza-Díaz, Corinne Amar, Gordon L. Nichols, and Jim McLauchlin
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United Kingdom ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
We developed a sensitive nested polymerase chain reaction (PCR) procedure for the Cryptosporidium oocyst wall protein (COWP) gene. Amplification and genotyping were successful in 95.2% of 1,680 fecal samples, 77.6% by the unnested and 17.6% by the nested COWP procedure. The COWP gene was amplified from 2,128 fecal samples: 71 from livestock animals and 2,057 from humans. This series included 706 cases from seven drinking water-associated outbreaks and 51 cases from five swimming pool-associated outbreaks, as well as 1,300 sporadic cases.
- Published
- 2001
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38. Utilization of pectoralis minor accessory inspiratory muscles in a rodent model of respiratory motor neuron loss
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Lauren F. Borkowski and Nicole L. Nichols
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medicine.anatomical_structure ,Pectoralis Minor ,Genetics ,medicine ,Rodent model ,Anatomy ,Respiratory system ,Motor neuron ,Biology ,Molecular Biology ,Biochemistry ,Biotechnology - Published
- 2021
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39. Cardiorespiratory responses to acute bouts of high-intensity functional training and traditional exercise in physically active adults
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Kyle D. Biggerstaff, Matthew F Brisebois, and David L. Nichols
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Adult ,Male ,medicine.medical_specialty ,Functional training ,business.industry ,High intensity ,Physical Therapy, Sports Therapy and Rehabilitation ,Cardiorespiratory fitness ,Blood Pressure ,High-Intensity Interval Training ,Blood pressure ,Energy expenditure ,Heart Rate ,Internal medicine ,Heart rate ,medicine ,Cardiology ,Humans ,Orthopedics and Sports Medicine ,Female ,Peak vo2 ,business ,Energy Metabolism ,Exercise - Abstract
BACKGROUND High-intensity functional training is a popular form of exercise, but little is known about how it compares to more traditional exercise patterns. METHODS Thirty healthy, physically active adults (15 males, 15 females) performed a high-intensity functional training workout (HIFT) and a traditional workout (TRAD). Cardiorespiratory responses were measured during and for 15 min after each workout. RESULTS Peak heart rate (males: 187 ± 7 vs. 171 ± 10 bpm, p < .001; females: 191 ± 9 vs. 175 ± 6 bpm, p < .001), peak VO2 (males: 3.80 ± 0.58 vs. 3.26 ± 0.60 L/min, p < .001; females: 2.65 ± 0.26 vs. 2.36 ± 0.21, p < .001), and average 15 min recovery VO2 (males: 1.15 ± 0.20 vs. 0.99 ± 0.17 L/min, p < .001; females: 0.77 ± 0.10 vs. 0.71 ± 0.07 L/min, p = .019) were significantly higher in HIFT vs. TRAD. Aerobic energy expenditure was significantly higher in HIFT compared to TRAD in males (9.01 ± 1.43 vs. 8.53 ± 1.38 kcal/min, p = .002) but was not significantly different between the two workouts in females (6.04 ± 0.53 vs. 5.97 ± 0.50 kcal/min, p = .395). Post-exercise systolic blood pressure (SBP) was significantly higher than pre-exercise SBP following both HIFT (males: 124 ± 13 mmHg pre to 154 ± 28 mmHg post, p < .001; females: 110 ± 7 mmHg pre to 140 ± 15 mmHg post, p < .001) and TRAD (males: 124 ± 13 mmHg pre to 142 ± 16 mmHg post, p = .002; females: 112 ± 8 mmHg pre to 123 ± 10 mmHg post, p = .002), however, HIFT led to a greater increase compared to TRAD in females (p = .001). Post-exercise diastolic blood pressure (DBP) was significantly lower than pre-exercise DBP following both HIFT (males: 77 ± 9 mmHg pre to 64 ± 6 mmHg post, p < .001; females: 71 ± 8 mmHg pre to 64 ± 7 mmHg post, p = .011) and TRAD (males: 82 ± 7 mmHg pre to 72 ± 7 mmHg post, p < .001; females: 73 ± 8 mmHg pre to 65 ± 8 mmHg post, p < .001). Mean arterial blood pressure was unchanged following both workouts. CONCLUSIONS High-intensity functional training may be an effective form of exercise for caloric expenditure and may elicit greater cardiorespiratory stress than traditional exercise.
- Published
- 2021
40. GRK2 Mediates β-Arrestin Interactions with 5-HT(2) Receptors for JC Polyomavirus Endocytosis
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Melissa S. Maginnis, Colleen L. Mayberry, Tristan M. Fong, Michael P. Wilczek, and Sarah L. Nichols
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media_common.quotation_subject ,Viral pathogenesis ,Immunology ,Population ,Biology ,Microbiology ,03 medical and health sciences ,0302 clinical medicine ,Viral entry ,Virology ,Arrestin ,medicine ,education ,Internalization ,030304 developmental biology ,Dynamin ,media_common ,0303 health sciences ,education.field_of_study ,Progressive multifocal leukoencephalopathy ,Signal transducing adaptor protein ,medicine.disease ,Virus-Cell Interactions ,Insect Science ,030217 neurology & neurosurgery - Abstract
JC polyomavirus (JCPyV) infects the majority of the population, establishing a lifelong, asymptomatic infection in the kidney of healthy individuals. People who become severely immunocompromised may experience JCPyV reactivation, which can cause progressive multifocal leukoencephalopathy (PML), a neurodegenerative disease. Due to a lack of therapeutic options, PML results in fatality or significant debilitation among affected individuals. Cellular internalization of JCPyV is mediated by serotonin 5-hydroxytryptamine subfamily 2 receptors (5-HT(2)Rs) via clathrin-mediated endocytosis. The JCPyV entry process requires the clathrin-scaffolding proteins β-arrestin, adaptor protein 2 (AP2), and dynamin. Furthermore, a β-arrestin-interacting domain, the Ala-Ser-Lys (ASK) motif, within the C terminus of 5-HT(2A)R is important for JCPyV internalization and infection. Interestingly, 5-HT(2)R subtypes A, B, and C equally support JCPyV entry and infection, and all subtypes contain an ASK motif, suggesting a conserved mechanism for viral entry. However, the role of the 5-HT(2)R ASK motifs and the activation of β-arrestin-associated proteins during internalization have not been fully elucidated. Through mutagenesis, the ASK motifs within 5-HT(2B)R and 5-HT(2C)R were identified as being critical for JCPyV internalization and infectivity. Furthermore, by using biochemical pulldown techniques, mutagenesis of the ASK motifs in 5-HT(2B)R and 5-HT(2C)R resulted in reduced β-arrestin binding. When small-molecule chemical inhibitors and RNA interference were used, G protein receptor kinase 2 (GRK2) was determined to be required for JCPyV internalization and infection by mediating interactions between β-arrestin and the ASK motif of 5-HT(2)Rs. These findings demonstrate that GRK2 and β-arrestin interactions with 5-HT(2)Rs are critical for JCPyV entry by clathrin-mediated endocytosis and the resultant infection. IMPORTANCE As intracellular parasites, viruses require a host cell to replicate and cause disease. Therefore, virus-host interactions contribute to viral pathogenesis. JC polyomavirus (JCPyV) infects most of the population, establishing a lifelong asymptomatic infection within the kidney. Under conditions of severe immunosuppression, JCPyV may spread to the central nervous system, causing the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). Individuals living with HIV or undergoing immunomodulatory therapies are at risk for developing PML. The mechanisms of how JCPyV uses specific receptors on the surface of host cells to initiate internalization and infection are poorly understood processes. We have further identified cellular proteins involved in JCPyV internalization and infection and elucidated their specific interactions that are responsible for the activation of receptors. Collectively, these findings illuminate how viruses usurp cellular receptors during infection, contributing to current development efforts for therapeutic options for the treatment or prevention of PML.
- Published
- 2021
41. A Tertiary Academic Medical Center Blood Bank's Experience With Four-Factor Prothrombin Complex Concentrate
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Aaron D Shmookler, Tracie L Nichols, and Peter Perrotta
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medicine.medical_specialty ,Rivaroxaban ,Pathology, Clinical ,business.industry ,Warfarin ,Transfusion medicine ,Pharmacy ,Hemorrhage ,General Medicine ,Emergency department ,030204 cardiovascular system & hematology ,Prothrombin complex concentrate ,Blood Coagulation Factors ,Tertiary Care Centers ,03 medical and health sciences ,0302 clinical medicine ,Emergency medicine ,medicine ,Blood Banks ,Humans ,Apixaban ,030212 general & internal medicine ,business ,Blood bank ,medicine.drug - Abstract
Objectives The role of transfusion medicine consultative services in prospectively auditing (PA) orders for four-factor prothrombin complex concentrate (4F-PCC) was evaluated at an academic medical center. Methods Data from 4 years of 4F-PCC orders were obtained from the laboratory information system, and electronic health records of patients receiving concentrate were reviewed. Results 4F-PCC was ordered for 427 patients with warfarin-, apixaban-, or rivaroxaban-associated hemorrhage. Turnaround time (TAT) to prepare 4F-PCC was longer when PA-recommended dose adjustments were needed (85 vs 66 minutes, P = .03). There was no difference in TAT between patients who died and those who were ultimately discharged (60 vs 70, P = .22). TAT was shortest for orders originating in the emergency department (ED) compared with other locations (64 vs 85, P Conclusions PA can ensure 4F-PCC is dosed appropriately without affecting patient outcomes.
- Published
- 2021
42. Ozone exposure during early pregnancy and preterm birth: A systematic review and meta-analysis
- Author
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Thomas J. Luben, R. Byron Rice, Kristen M. Rappazzo, and Jennifer L. Nichols
- Subjects
Early pregnancy factor ,010501 environmental sciences ,01 natural sciences ,Biochemistry ,Article ,03 medical and health sciences ,0302 clinical medicine ,Ozone ,Pregnancy ,Air Pollution ,Medicine ,Humans ,Meta-regression ,030212 general & internal medicine ,Ozone exposure ,0105 earth and related environmental sciences ,General Environmental Science ,Air Pollutants ,biology ,business.industry ,Infant, Newborn ,Pregnancy Outcome ,Prediction interval ,Random effects model ,Confidence interval ,Meta-analysis ,Cohort ,biology.protein ,Premature Birth ,Female ,Particulate Matter ,business ,Demography - Abstract
Exposure to ozone has been linked to reproductive outcomes, including preterm birth. In this systematic review, we summarize published epidemiologic cohort and case-control studies examining ozone exposures (estimated on a continuous scale) in early pregnancy (1(st) and 2(nd) trimesters (T1, T2)) and preterm birth using ratio measures, and perform a meta-analysis to evaluate the potential relationship between them. Studies were identified by searching PubMed and Web of Science, screened according to predefined inclusion/exclusion criteria, and evaluated for study quality. We extracted study data including effect estimates, confidence limits, study location, study years, ozone exposure assessment method, and mean or median ozone concentrations. Nineteen studies were identified and included, of which 18 examined T1 exposure (17 reported effect estimates), and 15 examined T2 exposure. Random effects meta-analysis was performed in the metafor package, R 3.5.3. The pooled OR (95% CI) for a 10 ppb increase in ozone exposure in T1 was 1.06 (1.03, 1.10) with a 95% prediction interval of 0.95, 1.19; for T2 it was 1.05 (1.02, 1.08) with a 95% prediction interval of 0.95, 1.16. Effect estimates for both exposure periods showed high heterogeneity. In meta-regression analyses of study characteristics, study location (continent) explained some (~20%) heterogeneity for T1 exposure studies, but no characteristic explained a substantial amount of heterogeneity for T2 exposure studies. Increased ozone exposure during early pregnancy is associated with preterm birth across studies.
- Published
- 2021
43. Small RNA and degradome deep sequencing reveals important roles of microRNAs in cotton (Gossypium hirsutum L.) response to root-knot nematode Meloidogyne incognita infection
- Author
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Baohong Zhang, Robert L. Nichols, Runrun Sun, Chao Li, Xiaoping Pan, Caiping Cai, and Kater Hake
- Subjects
0106 biological sciences ,Small RNA ,01 natural sciences ,Deep sequencing ,03 medical and health sciences ,Gene Expression Regulation, Plant ,Genetics ,medicine ,Meloidogyne incognita ,Root-knot nematode ,Animals ,Tylenchoidea ,KEGG ,Nematode Infections ,Gene ,030304 developmental biology ,0303 health sciences ,Gossypium ,biology ,High-Throughput Nucleotide Sequencing ,medicine.disease ,biology.organism_classification ,MicroRNAs ,Nematode ,Nematode infection ,010606 plant biology & botany - Abstract
Investigation of cotton response to nematode infection will allow us to better understand the cotton immune defense mechanism and design a better biotechnological approach for efficiently managing pest nematodes in cotton. In this study, we firstly treated cotton by root knot nematode (RKN, Meloidogyne incognita) infections, then we employed the high throughput deep sequencing technology to sequence and genome-widely identify all miRNAs in cotton; finally, we analyzed the functions of these miRNAs in cotton response to RKN infections. A total of 266 miRNAs, including 193 known and 73 novel miRNAs, were identified by deep sequencing technology, which belong to 67 conserved and 66 novel miRNA families, respectively. A majority of identified miRNA families only contain one miRNA; however, miR482 family contains 14 members and some others contain 2-13 members. Certain miRNAs were specifically expressed in RKN-infected cotton roots and others were completely inhibited by RKN infection. A total of 50 miRNAs were differentially expressed after RKN infection, in which 28 miRNAs were up-regulated and 22 were inhibited by RKN treatment. Based on degradome sequencing, 87 gene targets were identified to be targeted by 57 miRNAs. These miRNA-targeted genes are involved in the interaction of cotton plants and nematode infection. Based on GO (gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, 466 genes from all 636 miRNA targets were mapped to 6340 GO terms, 181 genes from 228 targets of differentially expressed miRNAs were mapped to 1588 GO terms. The GO terms were then categorized into the three main GO classes: biological processes, cellular components, and molecular functions. The targets of differentially expressed miRNAs were enriched in 43 GO terms, including 22 biological processes, 10 cellular components, and 11 molecular functions (p < 0.05). Many identified processes were associated with organism responses to the environmental stresses, including regulation of nematode larval development, response to nematode, and response to flooding. Our results will enhance the study and application of developing new cotton cultivars for nematode resistance.
- Published
- 2021
44. Enzyme-synthesized highly branched maltodextrins have slow glucose generation at the mucosal α-glucosidase level and are slowly digestible in vivo.
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Byung-Hoo Lee, Like Yan, Robert J Phillips, Bradley L Reuhs, Kyra Jones, David R Rose, Buford L Nichols, Roberto Quezada-Calvillo, Sang-Ho Yoo, and Bruce R Hamaker
- Subjects
Medicine ,Science - Abstract
For digestion of starch in humans, α-amylase first hydrolyzes starch molecules to produce α-limit dextrins, followed by complete hydrolysis to glucose by the mucosal α-glucosidases in the small intestine. It is known that α-1,6 linkages in starch are hydrolyzed at a lower rate than are α-1,4 linkages. Here, to create designed slowly digestible carbohydrates, the structure of waxy corn starch (WCS) was modified using a known branching enzyme alone (BE) and an in combination with β-amylase (BA) to increase further the α-1,6 branching ratio. The digestibility of the enzymatically synthesized products was investigated using α-amylase and four recombinant mammalian mucosal α-glucosidases. Enzyme-modified products (BE-WCS and BEBA-WCS) had increased percentage of α-1,6 linkages (WCS: 5.3%, BE-WCS: 7.1%, and BEBA-WCS: 12.9%), decreased weight-average molecular weight (WCS: 1.73×10(8) Da, BE-WCS: 2.76×10(5) Da, and BEBA-WCS 1.62×10(5) Da), and changes in linear chain distributions (WCS: 21.6, BE-WCS: 16.9, BEBA-WCS: 12.2 DPw). Hydrolysis by human pancreatic α-amylase resulted in an increase in the amount of branched α-limit dextrin from 26.8% (WCS) to 56.8% (BEBA-WCS). The α-amylolyzed samples were hydrolyzed by the individual α-glucosidases (100 U) and glucogenesis decreased with all as the branching ratio increased. This is the first report showing that hydrolysis rate of the mammalian mucosal α-glucosidases is limited by the amount of branched α-limit dextrin. When enzyme-treated materials were gavaged to rats, the level of postprandial blood glucose at 60 min from BEBA-WCS was significantly higher than for WCS or BE-WCS. Thus, highly branched glucan structures modified by BE and BA had a comparably slow digesting property both in vitro and in vivo. Such highly branched α-glucans show promise as a food ingredient to control postprandial glucose levels and to attain extended glucose release.
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- 2013
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45. Blood group A Secretors are associated with a higher risk of COVID-19 cardiovascular disease complications
- Author
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Christian J Stevens-Hernandez, Marie Attwood, Jennifer Pooley, Sabine Kupzig, David T Arnold, Fergus Hamilton, A Cooper, Nicola Cogan, David J. Anstee, Adam Finn, Ashley M. Toye, Claire Asby, Belinda K. Singleton, F Hosseini, Pedro Luis Moura, Gabriella Ruffino, Tosti J. Mankelow, L Nichols, G Gyorffy, F Moghaddas, Catherine Hyams, and Alan R. Noel
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medicine.medical_specialty ,Fucosyltransferase ,biology ,business.industry ,Disease ,Group A ,Phenotype ,Asymptomatic ,Virus ,ABO blood group system ,Internal medicine ,Cohort ,biology.protein ,Medicine ,medicine.symptom ,business - Abstract
The SARS-CoV-2 virus causes COVID-19, an infection capable of causing severe disease and death but which may also be asymptomatic or oligosymptomatic in many individuals. While several risk factors, including age, have been described, the mechanisms of this variation are poorly understood. Several studies have described associations between blood group and COVID-19 severity, while others do not. Expression of ABO glycans on secreted proteins and non-erythroid cells is controlled by a fucosyltransferase (FUT2). Inactivating mutations result in a non-secretor phenotype which is known to protect against some viral infections. We investigated whether ABO or secretor status was associated with COVID-19 severity. Data combined from healthcare records and laboratory tests (n=275) of SARS-CoV-2 PCR positive patients hospitalised with COVID-19, confirmed higher than expected numbers of blood group A individuals compared to O (RR=1.24, CI 95% [1.05,1.47], P=0.0111). There was also a significant association between group A and COVID-19-related cardiovascular complications (RR=2.56, CI 95% [1.43,4.55], P=0.0011) which is independent of gender. Molecular analysis of phenotype revealed that group A patients who are non-secretors are significantly less likely to be hospitalised than secretors. In a larger cohort of 1000 convalescent plasma donors, among whom the majority displayed COVID-19 symptoms and only a small minority required hospitalisation, group A non-secretors were slightly over-represented. Our findings indicate that group A non-secretors are not resistant to infection by SARS-CoV-2, but they are likely to experience a less severe form of its associated disease.Key PointsBlood group type A is associated with an increased risk of cardiovascular complications in COVID-19 patients.FUT2 “non-secretor” status reduces the risk of severe COVID-19 outcomes in patients with blood group A.
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- 2020
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46. A retrospective study on the association of gastrointestinal symptoms in children with low lactase activity and low activity of other disaccharidases
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Buford L. Nichols, Karla J AuYeung, Ann O. Scheimann, Wikrom Karnsakul, Paul Wasuwanich, Susan Billet, Christine Karwowski, Thammasin Ingviya, and Hassan Choudry
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Abdominal pain ,medicine.medical_specialty ,Duodenum ,medicine.medical_treatment ,Maltase-Glucoamylase ,Disaccharidases ,Gastroenterology ,Lactase activity ,Sucrase-isomaltase complex ,Sucrase ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Disaccharidases deficiency ,lcsh:RC799-869 ,Child ,Prospective cohort study ,Lactase ,Retrospective Studies ,business.industry ,030229 sport sciences ,General Medicine ,Lactase-Phlorizin hydrolase ,Disaccharidase ,Diarrhea ,Sucrase-Isomaltase complex ,lcsh:Diseases of the digestive system. Gastroenterology ,030211 gastroenterology & hepatology ,medicine.symptom ,business ,Research Article - Abstract
Background Disaccharides such as lactose and sucrose are sugars commonly found in human diet. They are broken down by mucosal disaccharidases in the duodenum. Previous small studies found no associations between gastrointestinal (GI) symptoms and combined low disaccharidase activity. We aim to explore the associations of low activity of disaccharidase and combinations of low activity of different disaccharidases with general GI symptom presentations in a large cohort of pediatric patients. Methods We examined a cohort (0–21 yrs.) who have undergone esophagogastroduodenoscopy and received disaccharidase activity assay from duodenal biopsy in the time period 2010 to 2012. Disaccharidase assays tested for activity of lactase, sucrase, maltase, and palatinase. GI symptoms were grouped into four categories, abdominal pain, diarrhea, weight loss, and gastroesophageal reflux. Results Of the 347 subjects, we found an association between low lactase activity and abdominal pain (OR = 1.78; 95% CI = 1.07–2.97; p p Conclusions Low activities of certain disaccharidase combinations may be associated with GI symptoms in subjects; a prospective study may be needed to investigate further.
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- 2020
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47. Physiological Responses to Multiple Low-Doses of Bacillus anthracis Spores in the Rabbit Model of Inhalation Anthrax
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Stephanie A. Hines, Tonya L. Nichols, Gregory V. Stark, Sarah C. Taft, Roy E. Barnewall, and Jason E. Comer
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Microbiology (medical) ,low-dose ,040301 veterinary sciences ,Physiology ,lcsh:Medicine ,Article ,0403 veterinary science ,03 medical and health sciences ,Respiration ,medicine ,Immunology and Allergy ,Molecular Biology ,Bacillus anthracis ,030304 developmental biology ,Inhalation exposure ,Colony-forming unit ,dose-response ,0303 health sciences ,General Immunology and Microbiology ,biology ,business.industry ,lcsh:R ,fungi ,anthrax ,04 agricultural and veterinary sciences ,biology.organism_classification ,medicine.disease ,Pathophysiology ,Spore ,Infectious Diseases ,Bacteremia ,multiple dose ,pathology ,physiological response ,business ,Respiration rate - Abstract
Bacillus anthracis spores that are re-aerosolized from surface deposits after initial contamination present significant health risks for personnel involved in decontamination. To model repeated exposure to low dose B. anthracis spores, three groups of seven rabbits were challenged with multiple low-doses of B. anthracis spores 5 days a week for 3 weeks. Mortality, body temperature, heart and respiration rates, hematology, C-reactive protein, bacteremia, and serum protective antigen were monitored for 21 days post-exposure after the last of multiple doses. All rabbits exposed to a mean daily dose of 2.91 ×, 102 colony forming units (CFU) survived and showed minimal physiological changes attributable to exposure. One of seven rabbits receiving a mean daily dose of 1.22 ×, 103 CFU died and four of seven receiving a mean daily dose of 1.17 ×, 104 CFU died. The LD50 was calculated to be 8.1 ×, 103 CFU of accumulated dose. Rabbits that succumbed to the higher dose exhibited bacteremia and increases above baseline in heart rate, respiration rate, and body temperature. Two rabbits in the mean daily dose group of 1.17 ×, 104 CFU exhibited clinical signs of inhalation anthrax yet survived. This study provides a description of lethality, pathophysiology, and pathology in a controlled multiple low-dose inhalation exposure study of B. anthracis in the rabbit model. The data suggest that the accumulated dose is important in survival outcome and that a subset of rabbits may show clinical signs of disease but fully recover without therapeutic intervention
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- 2020
48. Intralingual Administration of AAVrh10-miR(SOD1) Improves Respiratory But Not Swallowing Function in a Superoxide Dismutase-1 Mouse Model of Amyotrophic Lateral Sclerosis
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Nicole L. Nichols, Mai K. ElMallah, Angela L McCall, Christian Mueller, Justin S Dhindsa, Lori A Lind, Olivia E. Stricklin, Katherine A. Johnson, Ellyn M Andel, and Teresa E. Lever
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Male ,Pathology ,medicine.medical_specialty ,animal diseases ,Genetic Vectors ,Degeneration (medical) ,Superoxide dismutase ,03 medical and health sciences ,Impaired respiratory function ,Mice ,0302 clinical medicine ,Superoxide Dismutase-1 ,Swallowing ,Tongue ,Genetics ,Medicine ,Animals ,Respiratory system ,Amyotrophic lateral sclerosis ,Molecular Biology ,Research Articles ,030304 developmental biology ,0303 health sciences ,biology ,business.industry ,Amyotrophic Lateral Sclerosis ,nutritional and metabolic diseases ,Genetic Therapy ,Dependovirus ,medicine.disease ,nervous system diseases ,Deglutition ,Mice, Inbred C57BL ,Disease Models, Animal ,MicroRNAs ,medicine.anatomical_structure ,Phenotype ,030220 oncology & carcinogenesis ,biology.protein ,Breathing ,Molecular Medicine ,Female ,business ,Respiratory Insufficiency - Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by degeneration of motor neurons and muscles, and death is usually a result of impaired respiratory function due to loss of motor neurons that control upper airway muscles and/or the diaphragm. Currently, no cure for ALS exists and treatments to date do not significantly improve respiratory or swallowing function. One cause of ALS is a mutation in the superoxide dismutase-1 (SOD1) gene; thus, reducing expression of the mutated gene may slow the progression of the disease. Our group has been studying the SOD1(G93A) transgenic mouse model of ALS that develops progressive respiratory deficits and dysphagia. We hypothesize that solely treating the tongue in SOD1 mice will preserve respiratory and swallowing function, and it will prolong survival. At 6 weeks of age, 11 SOD1(G93A) mice (both sexes) received a single intralingual injection of gene therapy (AAVrh10-miR(SOD1)). Another 29 mice (both sexes) were divided into two control groups: (1) 12 SOD1(G93A) mice that received a single intralingual vehicle injection (saline); and (2) 17 non-transgenic littermates. Starting at 13 weeks of age, plethysmography (respiratory parameters) at baseline and in response to hypoxia (11% O(2)) + hypercapnia (7% CO(2)) were recorded and videofluoroscopic swallow study testing were performed twice monthly until end-stage disease. Minute ventilation during hypoxia + hypercapnia and mean inspiratory flow at baseline were significantly reduced (p 0.05). AAVrh10-miR(SOD1) injections also significantly extended survival in females by ∼1 week. In conclusion, this study indicates that intralingual AAVrh10-miR(SOD1) treatment preserved respiratory (but not swallowing) function potentially via increasing upper airway patency, and it is worthy of further exploration as a possible therapy to preserve respiratory capacity in ALS patients.
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- 2020
49. Differential mechanisms are required for phrenic long-term facilitation over the course of motor neuron loss following CTB-SAP intrapleural injections
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Lauren F. Borkowski and Nicole L. Nichols
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0301 basic medicine ,MAPK/ERK pathway ,Male ,Cholera Toxin ,Saporin ,Long-Term Potentiation ,Tropomyosin receptor kinase B ,Pharmacology ,Rats, Sprague-Dawley ,03 medical and health sciences ,0302 clinical medicine ,Developmental Neuroscience ,Medicine ,Animals ,Receptor ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Motor Neurons ,Pleural Cavity ,biology ,business.industry ,Intermittent hypoxia ,Motor neuron ,Saporins ,Rats ,Phrenic Nerve ,030104 developmental biology ,medicine.anatomical_structure ,nervous system ,Neurology ,embryonic structures ,biology.protein ,business ,030217 neurology & neurosurgery - Abstract
Selective elimination of respiratory motor neurons using intrapleural injections of cholera toxin B fragment conjugated to saporin (CTB-SAP) mimics motor neuron death and respiratory deficits observed in rat models of neuromuscular diseases. This CTB-SAP model allows us to study the impact of motor neuron death on the output of surviving phrenic motor neurons. After 7(d) days of CTB-SAP, phrenic long-term facilitation (pLTF, a form of respiratory plasticity) is enhanced, but returns towards control levels at 28d. However, the mechanism responsible for this difference in magnitude of pLTF is unknown. In naive rats, pLTF predominately requires 5-HT2 receptors, the new synthesis of BDNF, and MEK/ERK signaling; however, pLTF can alternatively be induced via A2A receptors, the new synthesis of TrkB, and PI3K/Akt signaling. Since A2A receptor-dependent pLTF is enhanced in naive rats, we suggest that 7d CTB-SAP treated rats utilize the alternative mechanism for pLTF. Here, we tested the hypothesis that pLTF following CTB-SAP is: 1) TrkB and PI3K/Akt, not BDNF and MEK/ERK, dependent at 7d; and 2) BDNF and MEK/ERK, not TrkB and PI3K/Akt, dependent at 28d. Adult Sprague Dawley male rats were anesthetized, paralyzed, ventilated, and were exposed to acute intermittent hypoxia (AIH; 3, 5 min bouts of 10.5% O2) following bilateral, intrapleural injections at 7d and 28d of: 1) CTB-SAP (25 μg), or 2) un-conjugated CTB and SAP (control). Intrathecal C4 delivery included either: 1) small interfering RNA that targeted BDNF or TrkB mRNA; 2) UO126 (MEK/ERK inhibitor); or 3) PI828 (PI3K/Akt inhibitor). Our data suggest that pLTF in 7d CTB-SAP treated rats is elicited primarily through TrkB and PI3K/Akt-dependent mechanisms, whereas BDNF and MEK/ERK-dependent mechanisms induce pLTF in 28d CTB-SAP treated rats. This project increases our understanding of respiratory plasticity and its implications for breathing following motor neuron death.
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- 2020
50. Glucose promotes resistance of human commensal Escherichia coli against contact-killing by pandemic Vibrio cholerae
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Peter Yunker, Holly L. Nichols, Sophia Wiesenfeld, Cristian V. Crisan, Brian K. Hammer, and Gabi Steinbach
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biology ,Effector ,biology.organism_classification ,medicine.disease_cause ,Microbiology ,cAMP receptor protein ,Immunity ,Vibrio cholerae ,biology.protein ,medicine ,Microbiome ,Escherichia coli ,Bacteria ,Type VI secretion system - Abstract
Evolutionary arms races among organisms are broadly prevalent and bacteria have evolved defensive strategies against various attackers. A common microbial aggression mechanism is the Type VI Secretion System (T6SS), a contact-dependent bacterial weapon used to deliver toxic effector proteins into adjacent target cells. Sibling cells constitutively express immunity proteins that neutralize effectors. However, less is known about mechanisms that allow non-sibling bacteria to respond to external cues and survive T6SS attacks independently of immunity proteins. In this study, we show that resistance to T6SS attacks is promoted by a genetically controlled response to exogenous glucose. We observe that multiple human Escherichia coli commensal strains lacking immunity proteins are sensitive to T6SS attacks from pandemic Vibrio cholerae on nutrient-rich media. By contrast, E. coli cells become resistant to attacks when co-cultured on the same media with glucose. We confirm that glucose does not impair V. cholerae T6SS activity. Instead, we find that cAMP receptor protein (CRP), which alters expression of hundreds of genes in response to glucose, controls resistance to T6SS attacks in E. coli cells. Consistent with the observed resistance on media with glucose, an E. coli crp disruption mutant survives significantly better against V. cholerae T6SS attacks even in the absence of glucose. Finally, we also show that resistance to T6SS attacks depends on the pH of the medium and varies based on the target and killer strains.IMPORTANCEMany Gram-negative bacteria, including important pathogens, encode T6SS genes to deliver toxic effectors and eliminate competitors. Our results uncover a novel defense mechanism against T6SS attacks that is triggered by an external stimulus and mediated by a metabolic response in non-kin target cells. In microbiomes such as those in gastrointestinal tracts where T6SS activity is known to occur, signaling by metabolites like glucose may affect the efficacy of T6SS attacks and alter microbial community composition. Our findings could have vast implications for microbial interactions during pathogen colonization of hosts and survival of bacterial cells in environmental communities. Furthermore, the glucose-mediated resistance observed here might provide a novel example of an evolutionary arms race between killer T6SS cells and target bacteria.
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- 2020
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