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Full-Text Articles in Biomedical Engineering and Bioengineering
Technology Aiding In Neonatal Lung Developmental Care, Megan Kirk
Technology Aiding In Neonatal Lung Developmental Care, Megan Kirk
Undergraduate Honors Theses
In this paper, old as well as new technological findings to decrease premature infant mortality are reviewed. This paper discusses fetal development throughout pregnancy from conception to full-term status as well as fetal lung development specifically from conception until full-term status. Several ideas to rapidly develop and mature fetal lungs are discussed such as mothers ingesting artificial surfactant supplements, either independently or coupled with antenatal corticosteroids, as well as intra-amniotic instillation prior to 28 weeks gestational. Drawbacks regarding these two are mentioned as well such as the fetus’s lungs not being mature enough to use the artificial surfactant leading into …
Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen
Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen
Electronic Theses and Dissertations
Chlamydia trachomatis (CT) replicates in macrophages, but is inhibited by IFN-$\gamma$ or LPS. IFN-$\gamma$ and/or LPS induced nitrite production in mouse peritoneal macrophages, macrophage cell lines (RAW264.7 and J774A.1) and McCoy cells. Kinetic studies indicated that peak production occurred 48 hours post-treatment. CT infection itself was insufficient to induce nitrite production, but resulted in enhancement of nitrite production in IFN-$\gamma$-treated cells. Treatment with IFN-$\gamma$ or LPS resulted in significant inhibition of CT replication in these cells. Strong correlation between nitrite production and inhibition of CT replication was observed in RAW264.7 and J774A.1 cells (correlation coefficients: $-$0.93 and $-$0.94, p $<$ 0.001). N$\sp{\rm g}$- monomethyl-L-arginine (L-NMMA) specifically inhibited nitrite production and partially reversed inhibition of CT replication in macrophage cell lines. NOS mRNA was measured in RAW264.7 cells by Northern blot and Dot blot hybridization. Strong correlation between NOS mRNA expression and inhibition of CT replication (correlation coefficient: $-$0.97, p $<$ 0.05) was observed. Anti-TNF-$\alpha$ antibody completely neutralized the biological activity of TNF-$\alpha$ secreted by LPS-treated RAW264.7 cells, yet the antibody neither reduced nitrite production nor restored CT replication. Combination of the antibody and L-NMMA significantly enhanced restoration of CT replication. In peritoneal macrophages, inhibition of CT replication induced by IFN-$\gamma$ was partially restored by L-NMMA or anti-TNF-$\alpha$ antibody. In McCoy cells, inhibition of CT replication induced by IFN-$\gamma$ and LPS was not significantly restored by L-NMMA. Great restoration of CT replication by 1 mM L-NMMA was observed in LPS-treated J774A.1 cells (31%), but not in IFN-$\gamma$-treated cells (5%). Our data indicate that (1) NO production is one of the mechanisms for inhibition of CT replication in IFN-$\gamma$-activated peritoneal macrophages and RAW264.7 cells; (2) NO plays a significant role in CT inhibition in LPS-treated macrophage cell lines, but not peritoneal macrophages; (3) TNF-$\alpha$ may be associated with inhibition, but the mechanism(s) may not involve NO production; (4) NO production may not be the mechanism for CT inhibition in McCoy cells treated with IFN-$\gamma$ and LPS.
Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites
Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites
Electronic Theses and Dissertations
Glycerophospholipids of mammalian cells exist as chemically diverse structures with various fatty acids at the sn-1 and sn-2 positions. Arachidonic acid, a polyunsaturated fatty acid, which may be converted to biologically active eicosanoids such as prostaglandins, thromboxanes, and leukotrienes, is found predominantly in the sn-2 position of glycerophospholipids. The purpose of this study was to examine, at the level of the individual molecular species, the incorporation of arachidonate into phospholipids and its release from phospholipids during stimulation. In this way, the specificity of the enzymes controlling arachidonate metabolism could be examined in order to clarify the processes that control the …