Influence of Partial Liquid Ventilation on Bacterial Growth and Alveolar Expansion in Newborn Rabbits with Group B-Streptococcal Pneumonia

Rüdiger, Mario; Some, Margareta; Jarstrand, Connie; Čalkovská, Andrea; Linderholm, Bim; Robertson, Bengt; Herting, Egbert

doi:10.1203/01.pdr.0000088070.62177.3a

Cited by 8 publications

(6 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have previously shown that PF5080 does not have an impact on bacterial growth of group B streptococci in vitro (39). However, in vivo data on preterm rabbits with connatal GBS pneumonia show a reduced amount of GBS in the lungs of PF5080-treated animals (15). Therefore, the protective effect of the present study on isolated ATII cells could be even more pronounced in an animal model of C. pneumoniae infection.…”

Section: Discussionmentioning

confidence: 52%

“…pneumoniae induce an inflammatory reaction in alveolar type II cells (8). PFC exhibit anti-inflammatory properties and have a beneficial effect in animal models of bacterial infection (14,15). Thus, intratracheal PFC application could be a promising supplementary therapy for patients with bacterial infections.…”

Section: Discussionmentioning

confidence: 99%

“…Intratracheal PFC application prolonged the survival of rats with bacterial pneumonia (14) and reduced the bacterial count in the lungs of newborn rabbits with connatal group B streptococcal pneumonia (15). Furthermore, PFC exhibit anti-inflammatory properties.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Perfluorocarbons Decrease Chlamydophila pneumoniae–Mediated Inflammatory Responses of Rat Type II Pneumocytes In Vitro

et al. 2006

Self Cite

View full text Add to dashboard Cite

Chlamydophila pneumoniae alter the expression of Toll-like receptor (TLR) 4 in alveolar type II (ATII)-cells. Subsequently nuclear factor kappaB (NF-B) is activated and tumor necrosis factor-␣ (TNF-␣) and macrophage inflammatory protein 2 (MIP-2) are produced. Perfluorocarbons (PFC) are beneficial in animals with bacterial pneumonia and reduce production of TNF-␣. Using isolated ATII-cells, it was studied whether PFC prevent C. pneumoniae-induced TNF-␣ and MIP-2 release and what the underlying pathway is. PF5080 preincubation prevented C. pneumoniae-induced secretion of TNF-␣ (43 Ϯ 10 versus 661 Ϯ 41 pg/mL) and MIP-2 (573 Ϯ 41 versus 4786 Ϯ 502 pg/mL). The C. pneumoniae-induced 2.2-fold increase of TNF-␣ Receptor 1 expression was reduced by PF5080. C. pneumoniae reduced cytoplasmatic IB␣ (3.7 Ϯ 0.3 versus 14 Ϯ 1) and increased NF-B p65 (31 Ϯ 7.5 versus 3.6 Ϯ 1.1) compared with control. PF5080 prevented NF-B activation. TLR4 expression was 1.5-fold higher after C. pneumoniae incubation, but remained at control levels after PF5080 pretreatment. After 24 h of C. pneumoniae incubation, in 88 Ϯ 6% of cells bacteria were found in the perinuclear region and in 50% of these cells bacteria adhered to cellular surface. After PF5080 preincubation, C. pneumoniae were in 32 Ϯ 4% attached to and in 5 Ϯ 1% internalized in ATII-cells. Since PF5080 was found in ATII-cell membranes, PF5080 effect could be explained by an alteration of the cellular membrane, preventing activation of the inflammatory cascade. Chlamydophila pneumoniae are obligate intracellular Gram-negative bacteria that cause respiratory infections in pediatric populations and adults (1,2). Recent studies demonstrated the presence of C. pneumoniae in alveolar macrophages and ATII cells in patients with chronic obstructive pulmonary disease (COPD) (3). Whereas most respiratory infections with C. pneumoniae are self-limited (4), bacterial colonization can lead to infectious exacerbations and development of COPD (5). Because detection rate of C. pneumonia varies significantly (6), the clinical relevance of C. pneumoniae is still controversial.The effect of C. pneumoniae on isolated ATII-cells is well characterized. C. pneumoniae inhibit the surfactant metabolism of ATII-cells after internalization (7). Many of C. pneumoniae-induced effects are mediated by cytokines. C. pneumoniae act at the ATII cell membrane to induce the expression of TLR4 (8). TLR signaling is partly mediated by the transcription factor NF-B, which controls the expression of many genes involved in the inflammatory response (9). C. pneumoniae-induced activation of NF-B leads to a release of the chemokine MIP-2 and the pro-inflammatory cytokine tumor necrosis factor alpha (TNF-␣) (8) and its receptor tumor necrosis factor receptor 1 (TNFR1). Together, they play an important role in bacterial infections and modulate the inflammatory process (10).PFC-administered as liquid (11), vapor (12), or gas (13) into the lung-represent an alternative approach to treat respiratory insufficiency. Intrat...

show abstract

Section: Discussionmentioning

confidence: 52%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Perfluorocarbons Decrease Chlamydophila pneumoniae–Mediated Inflammatory Responses of Rat Type II Pneumocytes In Vitro

et al. 2006

Self Cite

View full text Add to dashboard Cite

show abstract

“…Histological preparations were performed according to our standardized protocol as previously described (24,31). In short, lung tissues were embedded in paraffin and were transversely cut in sections of 4-m thickness.…”

Section: Methodsmentioning

confidence: 99%

“…From each animal, five sections that were an equal distance apart and thus representative for the entire lung were examined in a blinded manner by light microscopy. From each section 10 areas were chosen in a randomized manner, and alveolar expansion pattern and recruitment of inflammatory cells into the airspaces were evaluated as previously described (24) after staining with hematoxylin and eosin. Alveolar inflammation was graded semiquantitatively as absent, mild, or severe.…”

Section: Methodsmentioning

confidence: 99%

Intratracheal perfluorocarbons diminish LPS-induced increase in systemic TNF-α

Burkhardt¹,

Koehne²,

Wissel³

et al. 2008

American Journal of Physiology-Lung Cellular and Molecular Phys

Self Cite

View full text Add to dashboard Cite

Perfluorocarbons (PFC) reduce the production of various inflammatory cytokines, including TNF-alpha. The anti-inflammatory effect is not entirely understood. If anti-inflammatory properties are caused by a mechanical barrier, PFC in the alveoli should have no effect on the inflammatory response to intravenous LPS administration. To test that hypothesis, rats (n=31) were administered LPS intravenously and were either spontaneously breathing (Spont), conventionally ventilated (CMV), or receiving partial liquid ventilation (PLV). Serum concentration of TNF-alpha was measured. The pulmonary expressions of TNF-alpha and TNF-alpha receptor 1 protein and of TNF-alpha and ICAM-1 mRNA were determined. LPS caused a significant (P<0.001) increase in serum TNF-alpha. Serum TNF-alpha concentration was similar in LPS/Spont (525+/-180 pg/ml) and LPS/CMV (504+/-154 pg/ml) but was significantly (P<0.001) lower in animals of the LPS/PLV group (274+/-101 pg/ml). Immunohistochemical data on TNF-alpha protein expression showed a LPS-induced increase in TNF-alpha and TNF-alpha receptor 1 expression that was diminished by partial liquid ventilation. PCR measurements revealed a lower expression of TNF-alpha and ICAM-1 mRNA in LPS/PLV than in LPS/CMV or LPS/Spont animals. Semiquantitative histological evaluation revealed only minor alveolar inflammation with no significant differences between the groups. Low serum TNF-alpha concentration in PFC-treated animals is most likely explained by a decreased production of TNF-alpha in the lung.

show abstract

A supervisor for volume-controlled tidal liquid ventilator using independent piston pumps

Robert

Micheau

Walti

2007

Biomedical Signal Processing and Control

View full text Add to dashboard Cite

Influence of Partial Liquid Ventilation on Bacterial Growth and Alveolar Expansion in Newborn Rabbits with Group B-Streptococcal Pneumonia

Cited by 8 publications

References 33 publications

Perfluorocarbons Decrease Chlamydophila pneumoniae–Mediated Inflammatory Responses of Rat Type II Pneumocytes In Vitro

Perfluorocarbons Decrease Chlamydophila pneumoniae–Mediated Inflammatory Responses of Rat Type II Pneumocytes In Vitro

Intratracheal perfluorocarbons diminish LPS-induced increase in systemic TNF-α

A supervisor for volume-controlled tidal liquid ventilator using independent piston pumps

Contact Info

Product

Resources

About