Respiratory System Commons^™

Oxygen Saturation Among Newborn Infants And The Decrease Occurring During Feeding In Various Populations, Jennifer Lynn Allison

MUSC Theses and Dissertations

Pharyngeal and laryngeal structural movements coordinate respiration and swallowing functions, hence eliminating simultaneous execution. This research aims to document levels of oxygen saturation during rest and feeding among various newborn populations. Hypothesized is that an increase in oxygen alterations during feeding will be exhibited by infants of younger gestational age and, further, by those with the presence of respiratory anomalies. Thirty newborns in the nurseries at Medical University of South Carolina, free of cardiac and genetic maladies, were divided into three groups. Subjects of group 1 are healthy, full-term newborns; within groups 2 and 3, preterm infants (gestation). Subjects of …

Platelets Stimulate Fibroblast-Mediated Contraction Of Collagen Gels, Ulrika Zagai, Karin Fredriksson, Stephen I. Rennard, Joachim Lundahl, C. Magnus Sköld

Journal Articles: Pulmonary & Critical Care Med

BACKGROUND: Platelets are thought to play a role in a variety of inflammatory conditions in the lung, some of which may lead to fibrosis. In the current study we tested the hypothesis that whole platelets and platelet lysate can mediate remodelling of extracellular matrix in vitro by affecting fibroblast-mediated contraction of a collagen gel. We also sought to determine to what extent platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta) contribute to this effect.

METHODS: Washed platelets, isolated from healthy blood donors, and platelet lysate (freezing and thawing), were cast together with human lung fibroblasts in three-dimensional collagen gels. …

Staphylococcus Aureus Agr And Sara Functions Are Required For Invasive Infection But Not Inflammatory Responses In The Lung, Geoffrey Heyer, Shahryar Saba, Robert Adamo, William Rush, Grace Soong, Ambrose Cheung, Alice Prince

Dartmouth Scholarship

Staphylococcus aureus strains lacking agr- and sarA-dependent gene products or specific MSCRAMM (microbial surface components recognizing adhesive matrix molecules) adhesins were compared for the ability to activate inflammatory responses in the lung. The mutants were evaluated for virulence in a mouse model of pneumonia and by quantifying their ability to stimulate interleukin-8 (IL-8) and granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in respiratory epithelial cells. In a neonatal mouse, only strains with intact agr and sarA loci were consistently associated with invasive, fatal pulmonary infection (P < 0.001) and sarA was specifically required to cause bacteremia (P < 0.001). The agr and/or sarA mutants were, nonetheless, fully capable of producing pneumonia and were as proficient as the wild-type strain in stimulating epithelial IL-8 expression, a polymorphonuclear leukocyte chemokine, in airway cells. In contrast, agr and especially sarA mutants induced less epithelial GM-CSF expression, and MSCRAMM mutants lacking fibronectin binding proteins or clumping factor A, a ligand for fibrinogen, were unable to stimulate epithelial GM-CSF production. The ability to induce IL-8 expression was independent of the adherence properties of intact bacteria, indicating that shed and/or secreted bacterial components activate epithelial responses. While conserved staphylococcal components such as peptidoglycan are sufficient to evoke inflammation and cause pneumonia, the agr and sarA loci of S. aureus are critical for the coordination of invasive infection of the lungs.

Staphylococcus Aureus Rn6390 Replicates And Induces Apoptosis In A Pulmonary Epithelial Cell Line, Barbara C. Kahl, Mark Goulian, Willem Van Wamel, Mathias Herrmann, Sanford M. Simon, Gilla Kaplan, Georg Peters, Ambrose L. Cheung

Dartmouth Scholarship

Staphylococcus aureus frequently colonizes the airways of patients with compromised airway defenses (e.g., cystic fibrosis [CF] patients) for extended periods. Persistent and relapsing infections may be related to live S. aureus bacteria actively residing inside epithelial cells. In this study, we infected a respiratory epithelial cell line, which was derived from a CF patient, with S. aureus RN6390. Internalization of S. aureus was found to be time and dose dependent and could be blocked by cytochalasin D. Transmission electron microscopy revealed that internalized bacteria resided within endocytic vacuoles without any evidence of lysosomal fusion in a 24-h period. The results …

Repair Of The Airway Epithelium: Potential Opportunities For Therapeutic Intervention In Airway Disease, Stephen I. Rennard

Journal Articles: Pulmonary & Critical Care Med

The epithelium of the airway has considerable capacity to undergo repair. These repair processes are responsible for maintaining and restoring function after injury of the airways, which likely occurs often as a result of infectious, toxic or other exposures. However, repair processes need not be fully effective. Inadequate repair can take a number of forms and may result in metaplasia, hyperplasia or fibrotic scarring. It is likely that repair processes that lead to tissue disruption play an important role in the chronic airways diseases, such as asthma and bronchitis. Through delineation of these processes, it may become feasible to target …

Efficient Vasoactive Intestinal Polypeptide Hydrolyzing Autoantibody Light Chains Selected By Phage Display, Sonia Tyutyulkova, Qing-Sheng Gao, Austin Thompson, Stephen I. Rennard, Sudhir Paul

Journal Articles: Pulmonary & Critical Care Med

An immunoglobulin light chain (L chain) library derived from the peripheral blood lymphocytes of a patient with asthma was cloned into a phagemid vector. Phage particles displaying L chains capable of binding vasoactive intestinal polypeptide (VIP) were isolated by affinity chromatography. Two VIP binding L chains were expressed in Escherichia coli in soluble form and purified to electrophoretic homogeneity by metal chelating and protein L affinity chromatography. Both L chains catalyzed the hydrolysis of [tyr10-125I]VIP substrate. The catalytic activity eluted at the molecular mass of the monomer form of the L chain (28 kDa) from a gel filtration column. The …

Evaluation Of Nitric Oxide In Respiratory Distress Syndrome, Kimberly S. Myruski

Loma Linda University Electronic Theses, Dissertations & Projects

Little is known of the effects of low concentrations of inhaled nitric oxide (NO) on pulmonary mechanics and lung volumes in premature newborn infants with lung disease. Cardiopulmonary function tests including blood gas analyses were obtained from eleven premature lamb models with respiratory distress syndrome to determine if compliance, airways resistance, tidal volume, functional residual capacity, and gas exchange were affected. The effect of inhaled NO on the direction of shunting through the ductus arteriosus was determined using echocardiography.

Twin lambs were cannulated with arterial and venous catheters and intubated with an endotracheal tube before delivery on gestational day 126-130 …

Respiration In The Newborn Infant, A. Robert Bauer, Philip J. Howard

Henry Ford Hospital Medical Journal

No abstract provided.

Oxygen Physiology, Normal And Abnormal, Donald D. Van Slyke

Henry Ford Hospital Medical Journal

No abstract provided.

The Circulatory Effects Of Histamine, Fred B. Moor

Medical Arts and Sciences: A Scientific Journal of the College of Medical Evangelists

No abstract provided.