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Search Results: 1 - 10 of 168934 matches for " Kathleen E. Delgiorno "
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Persistent Salmonellosis Causes Pancreatitis in a Murine Model of Infection
Kathleen E. DelGiorno, Jason W. Tam, Jason C. Hall, Gangadaar Thotakura, Howard C. Crawford, Adrianus W. M. van der Velden
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0092807
Abstract: Pancreatitis, a known risk factor for the development of pancreatic ductal adenocarcinoma, is a serious, widespread medical condition usually caused by alcohol abuse or gallstone-mediated ductal obstruction. However, many cases of pancreatitis are of an unknown etiology. Pancreatitis has been linked to bacterial infection, but causality has yet to be established. Here, we found that persistent infection of mice with the bacterial pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) was sufficient to induce pancreatitis reminiscent of the human disease. Specifically, we found that pancreatitis induced by persistent S. Typhimurium infection was characterized by a loss of pancreatic acinar cells, acinar-to-ductal metaplasia, fibrosis and accumulation of inflammatory cells, including CD11b+ F4/80+, CD11b+ Ly6Cint Ly6G+ and CD11b+ Ly6Chi Ly6G? cells. Furthermore, we found that S. Typhimurium colonized and persisted in the pancreas, associated with pancreatic acinar cells in vivo, and could invade cultured pancreatic acinar cells in vitro. Thus, persistent infection of mice with S. Typhimurium may serve as a useful model for the study of pancreatitis as it relates to bacterial infection. Increased knowledge of how pathogenic bacteria can cause pancreatitis will provide a more integrated picture of the etiology of the disease and could lead to the development of new therapeutic approaches for treatment and prevention of pancreatitis and pancreatic ductal adenocarcinoma.
Deficiencies of the Lipid-Signaling Enzymes Phospholipase D1 and D2 Alter Cytoskeletal Organization, Macrophage Phagocytosis, and Cytokine-Stimulated Neutrophil Recruitment
Wahida H. Ali, Qin Chen, Kathleen E. Delgiorno, Wenjuan Su, Jason C. Hall, Tsunaki Hongu, Huasong Tian, Yasunori Kanaho, Gilbert Di Paolo, Howard C. Crawford, Michael A. Frohman
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0055325
Abstract: Cell migration and phagocytosis ensue from extracellular-initiated signaling cascades that orchestrate dynamic reorganization of the actin cytoskeleton. The reorganization is mediated by effector proteins recruited to the site of activity by locally-generated lipid second messengers. Phosphatidic acid (PA), a membrane phospholipid generated by multiple enzyme families including Phospholipase D (PLD), has been proposed to function in this role. Here, we show that macrophages prepared from mice lacking either of the classical PLD isoforms PLD1 or PLD2, or wild-type macrophages whose PLD activity has been pharmacologically inhibited, display isoform-specific actin cytoskeleton abnormalities that likely underlie decreases observed in phagocytic capacity. Unexpectedly, PA continued to be detected on the phagosome in the absence of either isoform and even when all PLD activity was eliminated. However, a disorganized phagocytic cup was observed as visualized by imaging PA, F-actin, Rac1, an organizer of the F-actin network, and DOCK2, a Rac1 activator, suggesting that PLD-mediated PA production during phagocytosis is specifically critical for the integrity of the process. The abnormal F-actin reorganization additionally impacted neutrophil migration and extravasation from the vasculature into interstitial tissues. Although both PLD1 and PLD2 were important in these processes, we also observed isoform-specific functions. PLD1-driven processes in particular were observed to be critical in transmigration of macrophages exiting the vasculature during immune responses such as those seen in acute pancreatitis or irritant-induced skin vascularization.
The neural encoding of self-generated and externally applied movement: implications for the perception of self-motion and spatial memory
Kathleen E. Cullen
Frontiers in Integrative Neuroscience , 2013, DOI: 10.3389/fnint.2013.00108
Abstract: The vestibular system is vital for maintaining an accurate representation of self-motion. As one moves (or is moved) toward a new place in the environment, signals from the vestibular sensors are relayed to higher-order centers. It is generally assumed the vestibular system provides a veridical representation of head motion to these centers for the perception of self-motion and spatial memory. In support of this idea, evidence from lesion studies suggests that vestibular inputs are required for the directional tuning of head direction cells in the limbic system as well as neurons in areas of multimodal association cortex. However, recent investigations in monkeys and mice challenge the notion that early vestibular pathways encode an absolute representation of head motion. Instead, processing at the first central stage is inherently multimodal. This minireview highlights recent progress that has been made towards understanding how the brain processes and interprets self-motion signals encoded by the vestibular otoliths and semicircular canals during everyday life. The following interrelated questions are considered. What information is available to the higher-order centers that contribute to self-motion perception? How do we distinguish between our own self-generated movements and those of the external world? And lastly, what are the implications of differences in the processing of these active versus passive movements for spatial memory?
Contribution of the Local RAS to Hematopoietic Function: A Novel Therapeutic Target
Kathleen E. Rodgers
Frontiers in Endocrinology , 2013, DOI: 10.3389/fendo.2013.00157
Abstract: The renin-angiotensin system (RAS) has long been a known endocrine system that is involved in regulation of blood pressure and fluid balance. Over the last two decades, evidence has accrued that shows that there are local RAS that can affect cellular activity, tissue injury, and tissue regeneration. There are locally active ligand peptides, mediators, receptors, and signaling pathways of the RAS in the bone marrow (BM). This system is fundamentally involved and controls the essential steps of primitive and definitive blood-cell production. Hematopoiesis, erythropoiesis, myelopoiesis, thrombopoiesis, formation of monocytic and lymphocytic lineages, as well as stromal elements are regulated by the local BM RAS. The expression of a local BM RAS has been shown in very early, primitive embryonic hematopoiesis. Angiotensin-converting enzyme (ACE-1, CD143) is expressed on the surface of hemangioblasts and isolation of the CD143 positive cells allows for recovery of all hemangioblast activity, the first endothelial and hematopoietic cells, forming the marrow cavity in the embryo. CD143 expression also marks long-term blood-forming CD34+ BM cells. Expression of receptors of the RAS is modified in the BM with cellular maturation and by injury. Ligation of the receptors of the RAS has been shown to modify the status of the BM resulting in accelerated hematopoiesis after injury. The aim of the present review is to outline the known functions of the local BM RAS within the context of primitive and definitive hematopoiesis as well as modification of BM recovery by administration of exogenous ligands of the RAS. Targeting the actions of local RAS molecules could represent a valuable therapeutic option for the management of BM recovery after injury as well as neoplastic disorders.
Frequent Beneficial Mutations during Single-Colony Serial Transfer of Streptococcus pneumoniae
Kathleen E. Stevens,Michael E. Sebert
PLOS Genetics , 2011, DOI: 10.1371/journal.pgen.1002232
Abstract: The appearance of new mutations within a population provides the raw material for evolution. The consistent decline in fitness observed in classical mutation accumulation studies has provided support for the long-held view that deleterious mutations are more common than beneficial mutations. Here we present results of a study using a mutation accumulation design with the bacterium Streptococcus pneumoniae in which the fitness of the derived populations increased. This rise in fitness was associated specifically with adaptation to survival during brief stationary phase periods between single-colony population bottlenecks. To understand better the population dynamics behind this unanticipated adaptation, we developed a maximum likelihood model describing the processes of mutation and stationary-phase selection in the context of frequent population bottlenecks. Using this model, we estimate that the rate of beneficial mutations may be as high as 4.8×10?4 events per genome for each time interval corresponding to the pneumococcal generation time. This rate is several orders of magnitude higher than earlier estimates of beneficial mutation rates in bacteria but supports recent results obtained through the propagation of small populations of Escherichia coli. Our findings indicate that beneficial mutations may be relatively frequent in bacteria and suggest that in S. pneumoniae, which develops natural competence for transformation, a steady supply of such mutations may be available for sampling by recombination.
Coping Complexity Model: Coping Stressors, Coping Influencing Factors, and Coping Responses  [PDF]
Kathleen Hudson
Psychology (PSYCH) , 2016, DOI: 10.4236/psych.2016.73033
Abstract:

Aim: To describe the complex phenomena of coping involving the stressors, influencing factors, and responses of coping via a mid-range theory Background: Previous models have presented the concepts of coping, this model expands previous models, creates a revision which is more complex and more comprehensive than previous work. Design: Model includes components of initial stressors, key critical coping influencing factors, and various types of coping responses, either healthy or unhealthy responses. Results: Coping is complex and multifaceted. This model portrays a comprehensive overview of the facets of coping, including temporary, effective, and destructive coping responses. A list of key influencing factors is presented to assist with highlighting possible factors that can influence the overall potential adaptive (healthy) or maladaptive responses (unhealthy). This model outlines the various possible pathways of coping. Conclusion: This model provides a comprehensive complex coping overview which can be used for education, clinical, and research applications.

Bismuth Toxicity: A Rare Cause of Neurologic Dysfunction  [PDF]
Paul T. Reynolds, Kathleen C. Abalos, Jennifer Hopp, Mark E. Williams
International Journal of Clinical Medicine (IJCM) , 2012, DOI: 10.4236/ijcm.2012.31010
Abstract: Bismuth subsalicylate (Pepto-Bismol?) and other bismuth-containing compounds have been used for many years to treat gastroenterological complaints. Although safe in the majority of patients, bismuth can cause a well-described toxic state marked by progressive neurological decline. Features of bismuth toxicity include confusion, postural instability, myoclonus, and problems with language. This presentation can masquerade as other causes of progressive neurologic dysfunction including Creutzfeld-Jakob Disease (CJD), Hashimoto’s Encephalopathy, and others. In this case study, we present a patient who was using bismuth salicylate in toxic quantities to help control diarrhea. On initial presentation, several diagnoses were entertained before bismuth levels were obtained. This case study highlights the fact that bismuth toxicity, while rare, should be considered in a patient with progressive neurological decline. Also, we hope this case reminds physicians of a severe consequence of a common, readily available medication.
Determinants of nurse faculty intention to remain employed  [PDF]
Ann E. Tourangeau, Heather Thomson, Margaret Saari, Kimberley Widger, Era Mae Ferron, Kathleen MacMillan
Open Journal of Nursing (OJN) , 2012, DOI: 10.4236/ojn.2012.23039
Abstract: Shortage of nurses is a major concern across healthcare systems. One contributing factor that has received little attention is the shortage of adequately prepared nurse faculty. The nurse shortage will be exacerbated if the supply of adequately prepared nurse faculty is insufficient. Little is known about the factors that influence nurse faculty to remain employed. Focus groups were conducted in 2011 with nurse faculty from both colleges and universities in Ontario, Canada. Six focus groups including 37 participants were held with different groups of nurse faculty in geographically diverse areas of the province. Focus group transcripts were reviewed by five members of the research team using thematic analysis strategies to identify factors related to nurse faculty intention to remain employed. Nurse faculty members’ intention to remain employed was influenced by factors that fell into four thematic categories: personal characteristics, work environment and organizational support, job content, and external characteristics. Each thematic category includes several factors reported to influence nurse faculty intention to remain employed. The “Determinants of Nurse Faculty Intention to Remain Employed” Model is hypothesized. Strategies to address modifiable factors and support non-modifiable factors are suggested to promote retention of nurse faculty. Additional research is needed to test the hypothesized model of nurse faculty intention to remain employed.
Functional Conducting Polymers via Thiol-ene Chemistry
Kathleen E. Feldman,David C. Martin
Biosensors , 2012, DOI: 10.3390/bios2030305
Abstract: We demonstrate here that thiol-ene chemistry can be used to provide side-chain functionalized monomers based on 3,4-propylenedioxythiophene (ProDOT) containing ionic, neutral, hydrophobic, and hydrophilic side chains. All reactions gave high yields and purification could generally be accomplished through precipitation. These monomers were polymerized either chemically or electro-chemically to give soluble materials or conductive films, respectively. This strategy provides for facile tuning of the solubility, film surface chemistry, and film morphology of this class of conducting polymers.
Consumption of a Diet Rich in Cottonseed Oil (CSO) Lowers Total and LDL Cholesterol in Normo-Cholesterolemic Subjects
Kathleen E. Davis,Chandan Prasad,Victorine Imrhan
Nutrients , 2012, DOI: 10.3390/nu4070602
Abstract: Animal data indicates that dietary cottonseed oil (CSO) may lower cholesterol; however, the effects of a CSO -rich diet have not been evaluated in humans. Thirty-eight healthy adults (aged 18–40; 12 males, 26 females) consumed a CSO rich diet (95 g CSO daily) for one week. Anthropometric measurements were obtained, and blood was drawn pre- and post-intervention. Serum lipids (total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), triglyceride (TG), and free fatty acids (FFA)) were assayed. There was no change in weight or waist circumference among participants. There was no change in HDL (Pre: 1.27 ± 0.4 mmol/L; Post: 1.21 ± 0.3 mmol/L) or TG (Pre: 0.91 ± 0.6 mmol/L; Post: 1.06 ± 1.0 mmol/L). Total cholesterol and LDL were reduced (TC Pre: 4.39 ± 0.9 mmol/L; Post: 4.16 ± 0.8 mmol/L; LDL Pre: 2.70 ± 0.8 mmol/L; Post: 2.47 ± 0.6 mmol/L). When data were grouped by sex, total cholesterol was reduced in female participants (Pre: 4.34 ± 0.9 mmol/L; Post: 4.09 ± 0.8 mmol/L). Consumption of a high fat, CSO-rich diet for one week reduced total cholesterol in female participants without reducing HDL.
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