• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 287
  • 186
  • 94
  • 29
  • 26
  • 21
  • 12
  • 10
  • 8
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 801
  • 801
  • 236
  • 184
  • 97
  • 95
  • 79
  • 76
  • 64
  • 61
  • 55
  • 54
  • 54
  • 52
  • 47
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Genetic Variation of the BETA-2 Adrenergic Receptor and the Bronchodilatory Response to Albuterol in Patients with Cystic Fibrosis

Herko, Kara, Guthrie, Benjamin, Snyder, Eric January 2012 (has links)
Class of 2012 Abstract / Specific Aims: We sought to determine the influence of genetic variation of ADRB2 on the airway response to albuterol in patients with CF when compared to matched healthy controls at baseline and at 60 minutes following the administration of albuterol (2.5mg diluted in 3ml normal saline). Methods: Baseline pulmonary function (forced vital capacity, FVC, forced expiratory flow in 1-second, FEV1, mid-maximal expiratory flow, MMF, and forced expiratory flow at 50% of the FVC) was assessed in 17 patients with CF and 31 healthy subjects. Main Results: As expected, the healthy group had higher baseline pulmonary function when compared to the CF group (FVC=97±3 vs. 83±5; FEV1=95±3 vs. 72±6; MMF=90±4 vs. 54±8, % predicted for healthy and CF, respectively, mean±SE, p<0.05 for all. We compared Arg16Arg to Arg16Gly/Gly16Gly subjects. There was no effect of genotype on the response to albuterol in healthy subjects. However, in the CF group, we found that the Arg16Arg group (n=6) had an attenuated response to β-agonist when compared to the Gly-containing group (n=11) (FVC=0±0.9 vs. 6±3: FEV1=3±1 vs. 7±4: MMF=12±3 vs. 12±5 % change, for Arg16Arg and Gly-containing groups, respectively, p<0.05 for FVC, p=0.06 for FEV1). Conclusions: These results demonstrate a differential response to β-agonists according to genetic variation of the ADRB2 at amino acid 16. Due to the differences in FVC and FEV1 but not in MMF, these data suggest that the genetic difference in airway function is primarily in bronchodilation of the larger airways.
232

Influence of genetic variation of the alpha-subunit of the epithelial sodium channel (ENaC) on baseline pulmonary function and exhaled sodium ions (Na+) and chloride ions (Cl-) in healthy subjects and patients with cystic fibrosis

Foxx-Lupo, William T. January 2012 (has links)
Class of 2012 Abstract / Specific Aims: The epithelial sodium channels (ENaC) found on the apical membranes of epithelial cells including those lining the respiratory tract are the rate limiting step of the absorption of excess fluid from the airspace of the alveoli. ENaC function is modulated by the effects of various physiologic signals such as the adrenergic and purinergic pathways, in addition to other local channels which control the flow of negatively charged ions such as the cystic fibrosis transmembrane conductance regulator (CFTR). We sought to determine the influence of genetic variation on the alpha subunit of ENaC at amino acid position 663 on baseline exhaled ions and pulmonary function in patients with CF. Methods: We assessed pulmonary function ( forced vital capacity[FVC], forced expiratory volume in one second [FEV1], forced expiratory flow maximum[FEFmax]) using a Medical Graphics cardiopulmonary testing device (Minneapolis, MN). Measures of exhaled sodium (Na+) and chloride (Cl-) were obtained using exhaled breathe condensate collected on a Jaeger Ecoscreen condenser unit (Cardinal Health, Yorba Linda, CA) with Na+ quantification using an atomic absorption spectrophotometer (Analyst 100; Perkin Elmer, Norwalk, CT) and Cl- anion quantification using a Dionex AS11 HC column. Healthy n=31 (n=18[58%], 9[29%], and 4[13%] subjects; Body mass index (BMI)=23±1, 25±2, and 25±2kg/ m2 for AA, AT and TT groups respectively). CF n= 42 (n=33[79%], 7[16%], and 2[5%] subjects; BMI equals 23±7, 19±0.4, and 20±2.2kg/m2 for AA, AT and TT groups respectively). Main Results: We found that the distribution of genotypes in CF differed from healthy subjects, with the AA genotype in 80% of CF and 59% in healthy. No significant difference were demonstrated in healthy subjects between genotype groups for pulmonary function and exhaled chloride while the genotypes did differ in exhaled Na (Na=2.9±0.4, 1.7±0.3, and 3.7±1.1mmol/L for AA, AT, and TT respectively, ANOVA p=0.07). CF subjects with the AA genotype had a higher baseline exhaled Cl-, FEV1, and FEFmax than those in the AA group (Cl=0.125±0.038,0.0 27±0.007, and 0.033±0.02 mmol/L ; FEV1=71±5, 68±11, and 40±22L; FEFmax=86±4, 72±7, and 44±24L/sec; for AA, AT, and TT respectively, ANOVA p<0.05, Tukey [AA vs. TT] p<0.05) while exhaled Na+ and FVC were similar between genotypes. Conclusions: Our results suggest that CF subjects with the AA genotype of the alpha subunit of the ENaC have a higher baseline exhaled Cl- and a resulting increase in pulmonary function when compared to the overactive TT groupCF patients with the TT αENaC genotype are likely candidates for early identification and treatment with inhaled ENaC inhibitors or other modulators of this pathway in order to improve survival.
233

The role of respiratory viruses in exacerbations of cystic fibrosis in adults

Flight, William George January 2014 (has links)
Viral respiratory infections (VRI) are common in children with cystic fibrosis (CF) and are associated with significant clinical deterioration. Little previous research has been conducted on VRI in adults with CF. This thesis describes a prospective study to determine the epidemiology and clinical impact of VRI among 100 adults with CF.The incidence of identifiable VRI was 1.66 cases/patient-year. Rhinovirus accounted for 72.5% of viruses. Identifiable VRI was associated with increased risk of pulmonary exacerbation, increased respiratory symptoms and higher C-reactive protein levels. Changes in the climate and seasons affected the incidence of identifiable VRI. Rhinovirus was most common in autumn and other viruses predominated during winter. Warmer ambient temperatures were associated with increased risk of rhinovirus infection while other viruses were more common in colder temperatures. Genetic sequencing of a subset of 42 rhinoviruses identified during the study showed that rhinovirus A accounted for 69% of cases and was associated with more severe respiratory symptoms and higher C-reactive protein levels than rhinovirus B.The impact of identifiable VRI on changes to bacterial communities within the lungs of patients with CF was investigated. Ribosomal intergenic spacer analysis (RISA) was developed as a tool to profile the bacterial diversity of CF sputum and was compared with standard culture and 16S rRNA gene pyrosequencing. No consistent effect of identifiable VRI on the microbial diversity of CF sputum was detected with any of these methods in longitudinal analysis of a subset of 18 patients.
234

Gene transfer vector development to treat lung disease

Harding-Smith, Rebekka January 2014 (has links)
No description available.
235

Evaluation of Safety and Efficacy Outcomes from use of Extended Infusion of Beta-Lactam in the treatment of Acute Pulmonary Exacerbations in Cystic Fibrosis

Tien, Quang, Sivinski, Jared, Lew, Darren January 2017 (has links)
Class of 2017 Abstract / Objectives: The objective of this retrospective cohort chart review was to evaluate the safety and efficacy of extended infusion beta-lactam regimens as part of treatment of acute CF pulmonary exacerbations in adults and pediatric patients. Methods: Inclusion criteria: adult and pediatric patients (age 1 month or older) with CF diagnosis who were admitted to BUMC-T for acute pulmonary CF exacerbation, and who received meropenem, imipenem, aztreonam, piperacillin-tazobactam, and or cefepime during their hospitalization (between 1/1/2011 and 10/30/2015). Exclusion criteria: pregnant women and admissions less than 24 hours. The two groups evaluated were patients receiving treatment (group 1) prior to extend infusion practices (Jan 2011 – Dec 2012) and (group 2) after implementation of extend infusion practices (Jan 2013 – Oct 2015). Data was collected from medical records using both the Sunrise Clinical Manager and EPIC electronic medical record systems. The data was then analyzed for differences in efficacy outcomes (e.g., length of hospitalization, lung function, return to baseline lung function), changes in renal and hepatic function, incidence of documented adverse drug effects, and potential factors associated with increased risk for changes in renal or hepatic function with use of extended infusion beta‐lactam regimens. Results: Pending. Efficacy outcomes: - length of hospitalization - improvement in lung function - return to baseline lung function Safety outcomes: - changes in renal and hepatic function - incidence of documented adverse drug effects - potential factors associated with increased risk for changes in renal or hepatic function Conclusions: Pending. As this study is being conducted at one academic medical center, conclusions may not be generalizable to other institutions.
236

Epidemiologia das infecções bacterianas em pacientes com fibrose cística envolvendo Achromobacter e bactérias do complexo Burkholderia cepacia / Epidemiology of bacterial infections in patients with cystic fibrosis involving Achromobacter and Burkholderia cepacia complex

Carolina Paulino da Costa Capizzani 14 June 2017 (has links)
Achromobacter sp. e Burkholderia sp. são considerados patógenos problemáticos em pacientes com fibrose cística (FC), principalmente por apresentarem linhagens que podem ser transmissíveis e multidroga resistentes. Este trabalho teve como objetivo analisar isolados de Achromobacter e do complexo Burkholderia cepacia (CBc) de pacientes com FC atendidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP-USP) e no Hospital das Clínicas da Faculdade de Ciências Médicas de Campinas (HCFCM-UNICAMP): identificar gênero/espécies; avaliar a sensibilidade a antimicrobianos; investigar relações genéticas entre os isolados por Pulsed-field Gel Electrophoresis (PFGE); elucidar a taxonomia e epidemiologia molecular dos isolados por Multilocus Sequence Typing (MLST) e correlacionar os resultados com dados clínicos. Entre julho/2011 a setembro/2014, nos dois hospitais, as espécies mais prevalentes de Achromobacter e CBc foram A. xylosoxidans e B. vietnamiensis, respectivamente. Os antibióticos mais efetivos contra isolados de Achromobacter sp. de pacientes do HCFMRP-USP foram imipenem e meropenem e do HCFCM-UNICAMP foram meropenem e ceftazidima. Os antibióticos mais efetivos contra CBc de pacientes do HCFMRP-USP foram sulfametoxazol-trimetoprim e meropenem e do HCFCM-UNICAMP foram ceftazidima e meropenem. Houve suspeita de contaminação cruzada entre alguns pacientes que apresentaram isolados com o mesmo perfil de PFGE. No HCFMRP-USP, isolados de B. vietnamiensis de pacientes diferentes tiveram o mesmo perfil de PFGE e apenas 2 pacientes tinham infecção crônica. No HCFCM-UNICAMP, isolados de B. cenocepacia IIIB de 4 pacientes apresentaram o mesmo pulsotipo, porém nenhum dos pacientes tinha infecção crônica. Isolados de B. vietnamiensis e B. multivorans de pacientes diferentes no HCFCM-UNICAMP também apresentaram o mesmo pulsotipo, e apenas um paciente colonizado por B. multivorans tinha infecção crônica. No HCFCM-UNICAMP, isolados de Achromobacter apresentaram perfis únicos de PFGE, enquanto que no HCFMRP-USP houve suspeita de contaminação cruzada somente entre pacientes colonizados por A. xylosoxidans, sendo que 3 destes pacientes estavam com infecção crônica. Nos dois hospitais, 17 STs foram identificados em isolados do CBc, 14 deles pela primeira vez e 3 STs (ST17, ST369 e ST911) apresentaram distribuição intercontinental. Em isolados de pacientes dos dois hospitais foram identificados alguns STs em comum (STs 1056, 1057, 369 e 911), o que pode sugerir ancestral comum. No total, 6 STs diferentes foram identificados em isolados de A. xylosoxidans de pacientes do HCFMRP-USP, dos quais 3 STs apareceram pela primeira vez e os outros 3 STs apresentaram distribuição intercontinental. Nenhuma das espécies apresentou linhagens epidêmicas descritas. Os pacientes colonizados cronicamente por A. xylosoxidans apresentaram valores de escore de Shwachman, índice de massa corporal (IMC) e função pulmonar menos preservados e exacerbações ligeiramente mais frequentes do que pacientes colonizados por bactérias do CBc. Este estudo possibilitou a correta identificação dos patógenos proporcionando a adoção de medidas de controle mais efetivas e tratamentos mais adequados, além de atualização do banco de dados epidemiológicos, o que facilita a análise colaborativa multicêntrica e auxilia no controle de infecção global destes patógenos. / Achromobacter sp. and Burkholderia sp. are troublesome pathogens in cystic fibrosis (CF) patients, mainly because they may have transmissible and multidrug resistant strains. The aim of this study was to analyze the Achromobacter and Burkholderia cepacia complex (Bcc) isolates from CF patients treated at the Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP-USP) and Hospital das Clínicas da Faculdade de Ciências Médicas de Campinas (HCFCM-UNICAMP); to identify genus/species; to evaluate antimicrobial susceptibility; to investigate clonal relatedness among isolates by Pulsed-field Gel Electrophoresis (PFGE); to elucidate taxonomy and molecular epidemiology of the isolates by Multilocus Sequence Typing (MLST), and to relate the results to clinical data. Between July/2011 and September/2014, in both hospitals, the most prevalent species of Achromobacter and Bcc were A. xylosoxidans and B. vietnamiensis, respectively. The most effective antibiotics against Achromobacter sp. isolates of patients from HCFMRP-USP were imipenem and meropenem, and from HCFCM-UNICAMP were meropenem and ceftazidime. The most effective antibiotics against Bcc isolates of patients from HCFMRP-USP were sulfamethoxazole-trimethoprim and meropenem, and from HCFCM-UNICAMP were ceftazidime and meropenem. Cross-contamination was suspected among some patients who presented isolates with the same PFGE profile. In HCFMRP-USP, isolates of B. vietnamiensis from different patients showed the same PFGE profile, and only 2 patients had chronic infection. In HCFCM-UNICAMP, isolates of B. cenocepacia IIIB of 4 patients showed the same pulsetype, but none of the patients had chronic infection. Isolates of B. vietnamiensis and B. multivorans from different patients from HCFCM-UNICAMP also showed the same pulsetype, and only one patient colonized by B. multivorans had chronic infection. In HCFCM-UNICAMP, Achromobacter isolates showed unique profiles of PFGE, whereas in HCFMRP-USP cross-contamination was only suspected among patients colonized by A. xylosoxidans, and 3 of these patients had chronic infection. In both hospitals, 17 STs were identified in Bcc isolates, 14 of them for the first time and 3 STs (ST17, ST369 and ST911) presented intercontinental distribution. In both hospitals, some common STs (STs 1056, 1057, 369 and 911) were identified, which may suggest a common ancestor. In total, 6 different STs were identified in A. xylosoxidans isolates of patients from HCFMRP-USP, of which 3 STs were identified for the first time, and the other 3 STs presented intercontinental distribution. None of the species presented described epidemic strains. Patients chronically colonized by A. xylosoxidans showed less preserved Shwachman score, body mass index (BMI) and lung function, and slightly more frequent exacerbations than patients colonized by Bcc bacteria. This study provided the correct identification of the pathogens, allowing the adoption of more effective control measures and adequate treatments, besides updating the epidemiological database, which facilitates the multicentric collaborative analysis and assists in the control of global infection of these pathogens
237

Studies on the pathophysiological basis of cystic fibrosis airway disease in newborn pigs

Hoegger, Mark Jeffrey 01 May 2015 (has links)
Cystic fibrosis (CF) is a common lethal hereditary disease resulting from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CFTR dysfunction affects multiple organ systems and most morbidity and mortality in CF results from lung disease. The CF lung appears healthy at birth, but spontaneously develops airway disease characterized by infection, inflammation, mucus plugging and airway remodeling. A CF pig model was recently generated to determine the events that initiate lung disease. CF pigs recapitulate many findings seen in humans with CF, including the spontaneous development of lung disease. I used newborn CF pigs to investigate two leading hypotheses regarding CF disease initiation: abnormal airway surface liquid (ASL) composition and defective mucociliary transport (MCT). I developed an assay to study ASL composition and found that CF ASL contained similar sodium concentrations, elevated potassium concentrations, and a decreased fraction of volatile material. I developed an assay to measure MCT in vivo. By tracking individual particles in 3-dimensions I found that newborn pigs exhibit a ventrally directed cilia orientation in the trachea. I also found that MCT is highly heterogeneous and particles traveled at different speeds within airways and between airways, challenging the classic view that airway mucus exists as continuous blanket. Comparing particle transport revealed that non-CF and CF newborn pigs exhibit similar basal particle clearance and speeds. Cholinergic stimulation induces mucus and fluid secretion. Particles became stuck in newborn CF pigs after cholinergic stimulation and stasis persisted with tissue submersion. This challenged the leading hypothesis that attributes CF airway disease pathogenesis to ASL depletion. I hypothesized that adherent mucus impairs mucociliary transport in CF airways and I developed an assay to visualize mucus stasis in submerged tracheal segments ex vivo. CF trachea stimulated in vivo exhibited highly adhesive mucus entities that emerged exclusively from submucosal gland ducts. These adherent entities impaired MCT even with extremely high ASL depths. Non-CF trachea with combinatorial disruption of HCO3- and Cl- transport reproduced the defect in CF signifying that anion transport disruption was responsible for adherent mucus. These data suggest that CFTR disruption directly produces multiple host defense defects, including defective bacterial killing and abnormally adherent mucus. Therapeutic targeting of the described defects may provide new opportunities to intervene early and improve the lives of those with CF.
238

Regulation Of gene expression in cystic fibrosis: implications for biology and therapeutics

Ramachandran, Shyam 01 May 2012 (has links)
Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel that when mutated causes the disease cystic fibrosis (CF). Many obstacles hinder the understanding of CF disease pathogenesis, impeding advancements in understanding how mutations cause disease, and slowing the progress towards new treatments. To this end, we have profiled the transcriptome (mRNA and microRNA) of human and newborn pig CF and non-CF airway epithelia. We show that the use of cross-species transcriptomics allows the identification of genes differentially expressed owing to the loss of CFTR, and not due to confounding environmental or secondary disease progression influences. The identification of reduced OAS1 expression in CF samples is a case in point. We also demonstrate the utility of transcriptome profiling and longitudinal studies in pigs, providing greater understanding of the molecular mechanisms underlying CF disease progression. MicroRNAs (miRNAs) comprise a large family of ~21-nt long non-coding RNAs that function as key post-transcriptional regulators of gene expression. Very little is known of how CFTR is regulated in the cell, both transcriptionally and post-transcriptionally. We discovered three miRNAs: miR-509-3p, miR-494 and miR-138 with possible CFTR regulatory functions. miR-509-3p or -494 directly target the CFTR mRNA, and decrease CFTR levels when over expressed; while inhibiting them had the opposite effect. Upon stimulating human airway epithelial cells with TNFα or IL-1β, we observed an increase in expression of both miRNAs mediated in part by the NF-κB transcription factor complex, with a concurrent decrease in CFTR expression. Gene ontology classification of predicted targets of miR-509-3p and/or miR-494 expressed in the airway epithelium revealed enrichment for genes in ion transport pathways. To our knowledge, this is the first suggestion of a possible role for miRNAs regulating a broad range of important epithelial electrolyte and fluid transport proteins. The study of miR-138 mediated regulation of CFTR expression has led to novel discoveries in the field of CFTR transcriptional control. We discovered SIN3A to be a novel transcriptional repressor of CFTR, interacting with CTCF on the CFTR promoter at the -20.9 kb DHS. By validating SIN3A as a conserved target of miR-138, we also discovered miR-138 to be a novel transcriptional regulator/activator of CFTR. The most common CFTR mutation, ΔF508, causes protein misfolding, degradation, and CF. Manipulating the miR-138/SIN3A regulatory network improved the biosynthesis of CFTR-ΔF508, restoring Cl- transport to human CF airway epithelia. To our knowledge, this is the first example of an individual miRNA having such broad regulatory functions. This discovery also provided novel targets for restoring CFTR function in cells affected by the most common CF mutation. To this end, we are utilizing the molecular signatures of miR-138 over-expression and SIN3A knockdown to identify candidate genes for RNA interference screens, and to identify candidate small molecule drugs that might mimic the effects of these two interventions. The goal of this approach is to develop a new therapeutic agent that restores anion transport to airway epithelia and other cell types and tissues affected by CF.
239

GENOTYPIC SPERM SORTING: A less invasive “ART” to prevent Genetic Disorders in Newborns

Unknown Date (has links)
Genetic disorders like Cystic Fibrosis (CF) and X-linked Diseases (XLD) are inherited by offspring from parents who are healthy carriers of the autosomal recessive or allosomal genes. About 10-million Americans are healthy carriers of a mutant cysticfibrosis gene (predominantly F508del) and about 4% of newborns are at risk of being born with an X-linked disease. The current clinically approved mitigation plan for preventing genetic disorders in newborns from “at-risk couples” is to consider Preimplantation Genetic Testing for Monogenetic diseases (PGT-M). PGT-M involves an invasive microsurgical procedure that requires the removal of cells from 3-5day old embryos. To minimize this invasiveness, we proposed a less invasive approach to prevent genetic disorders in newborns by genotypically sorting sperm cells which may be used for fertilization events (IUI/IVF/ICSI) with specially characterized antigens on the sperm surface membrane. For the disease models being adopted in our study – CF and XLD; we utilized certain monoclonal antibodies (mab) to target the H-Y male antigen and the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein which are both selectively expressed on the sperm surface. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection
240

Engineering extracellular environments to study and treat lung pathologies

Pinezich, Meghan January 2022 (has links)
Lung disease is the third leading cause of death worldwide. The only curative intervention for end-stage lung disease is lung transplantation, which remains limited by the shortage of viable donor organs. Strategies to improve outcomes for patients with end-stage lung disease include: (i) ex vivo recovery of initially unusable donor lungs to a level suitable for transplantation, and (ii) repair of damaged lungs in situ to avoid the need for transplantation. Recovery of damaged lungs both ex vivo and in situ necessitates precise regulation of the lung extracellular environment, which includes biochemical, physical, and mechanical stimuli across scales. This thesis describes the development of bioengineering tools, including bioreactors and biomaterials, that leverage the lung extracellular environment across cellular, tissue, and organ scales to: (i) recover whole injured donor lungs ex vivo, (ii) assess and repair regional lung tissue injury in situ, and (iii) study the pathological cellular microenvironment in cystic fibrosis. In Chapter 1, regulation of the organ macroenvironment (ventilation, perfusion, systemic metabolism) with a homeostatic cross-circulation bioreactor enabled up to 100 hours of ex vivo lung support and recovery of injured human donor lungs. In Chapter 2, quantitative analysis of localized lung tissue properties, including lung sounds, enabled detection and assessment of pulmonary air leak, and recapitulation of lung microenvironmental features (structure, mechanics, composition) in a therapeutic biomaterial sealant enabled rapid treatment of air leaks. In Chapter 3, the first quantitative characterization of the cystic fibrosis matrisome (matrix proteome) identified pathological alterations to the microenvironment, and investigated implications for inflammation and immunity in cystic fibrosis. Collectively, these studies demonstrate that macro- and microenvironmental signals, including ventilation and perfusion mechanics, homeostatic metabolic regulation, and extracellular matrix structure and composition, can be leveraged to reveal previously unknown drivers of disease and promote recovery and repair of damaged lungs.

Page generated in 0.0709 seconds