Human alveolar epithelial cells induce nitric oxide synthase-2 expression in alveolar macrophages.

It was hypothesized that cell-to-cell interaction between human alveolar macrophages (AM) and alveolar epithelium, might be an important factor leading to nitric oxide synthase-2 (NOS2) messenger ribonucleic acid (mRNA) and protein expression by constituent cells of the alveolar wall and/or AM. NOS2 mRNA and the protein expression patterns of human AM and alveolar epithelial cells type II (AEC-II) isolated from normal parts of lung resections of patients with pulmonary malignancies were determined. In addition, NOS2 mRNA expression in human AM co-cultured with autologous AEC-II in the presence of pro-inflammatory cytokines interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma or lipopolysaccharide (LPS) was investigated. The effect of human surfactant protein-A (SP-A) on IFN-gamma-mediated NOS2 mRNA expression in human AM was also studied. Neither NOS2 mRNA nor protein could be detected in freshly isolated, unstimulated or cytokine-stimulated AEC-II. In contrast, freshly isolated AM from bronchoalveolar lavage or lung tissue samples expressed immunoreactivity for NOS2 protein, but no NOS2 mRNA could be detected by reverse transcriptase polymerase chain reaction. All stimuli tested failed to induce NOS2 mRNA expression in human AM in vitro. Only AM-AEC-II co-culture in the presence of IFN-gamma led to NOS2 mRNA and protein expression. In situ hybridization of NOS2 mRNA on lung tissue explants and immunohistochemical staining of cytospin preparations of AM-AEC-II co-cultures demonstrated that NOS2 is expressed in AM but not in AEC-II. This co-culture effect could not be reproduced by substitution of AEC-II with SP-A. These data give evidence of a regulatory network controlling human nitric oxide synthase-2 expression in the lower respiratory tract.

Tuber physiology and properties of starch from tubers of transgenic potato plants with altered plastidic adenylate transporter activity.

We showed recently that antisense plants with decreased activity of the plastidic ATP/ADP-transporter protein exhibit drastically reduced levels of starch and a decreased amylose/amylopectin ratio, whereas sense plants with increased activity of the transporter possessed more starch than wild-type plants and an increased amylose/amylopectin ratio. In this paper we investigate the effect of altered plastidic ATP/ADP-transporter protein expression on primary metabolism and granule morphology in more detail. Tuber tissues from antisense and sense plants exhibited substantially increased respiratory activity compared with the wild type. Tubers from antisense plants contained markedly increased levels of free sugars, UDP-Glc, and hexose phosphates, whereas phosphoenolpyruvate, isocitrate, ATP, ADP, AMP, UTP, UDP, and inorganic pyrophosphate levels were slightly decreased. In contrast, tubers from sense plants revealed a slight increase in adenine and uridine nucleotides and in the levels of inorganic pyrophosphate, whereas no significant changes in the levels of soluble sugars and metabolites were observed. Antisense tubers contained 50% reduced levels of ADP-Glc, whereas sense tubers contained up to 2-fold increased levels of this sole precursor for starch biosynthesis. Microscopic examination of starch grain morphology revealed that the size of starch grains from antisense tubers was substantially smaller (50%) compared with the wild type. The large starch grains from sense tubers appeared of a more angular morphology, which differed to the more ellipsoid shape of wild type grains. The results suggest a close interaction between plastidial adenylate transport and starch biosynthesis, indicating that ADP-Glc pyrophosphorylase is ATP-limited in vivo and that changes in ADP-Glc concentration determine starch yield, as well as granule morphology. Possible factors linking starch synthesis and respiration are discussed.

Surfactant protein A differentially regulates IFN-gamma- and LPS-induced nitrite production by rat alveolar macrophages.

Although several studies have demonstrated that the pulmonary collectins surfactant protein (SP)-A and SP-D contribute to innate immunity by enhancing pathogen phagocytosis, the role of SP-A and SP-D in regulating production of free radicals and cytokines is controversial. We hypothesized that the state and mechanism of activation of the immune cell influence its response to SP-A. The effects of SP-A and SP-D on production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) were assessed in isolated rat alveolar macrophages activated with lipopolysaccharide (LPS), interferon gamma (IFN-gamma), or both agonists. SP-A inhibited production of NO and iNOS in macrophages stimulated with smooth LPS, which did not significantly bind SP-A, or rough LPS, which avidly bound SP-A. In contrast, SP-A enhanced production of NO and iNOS in cells stimulated with IFN-gamma or INF-gamma plus LPS. Neither SP-A nor SP-D affected baseline NO production, and SP-D did not significantly affect production of NO in cells stimulated with either LPS or IFN-gamma. These results suggest that SP-A contributes to the lung inflammatory response by exerting differential effects on the responses of immune cells, depending on their state and mechanism of activation.

Temporal sequence of pulmonary and systemic inflammatory responses to graded polymicrobial peritonitis in mice.

The lungs are the remote organ most commonly affected in human peritonitis. The major goals of this study were to define the dose- and time-dependent relationship between graded septic peritonitis and systemic and pulmonary inflammatory responses in mice. BALB/c mice were treated with intraperitoneal polymicrobial inoculi and sacrificed at 3, 12, and 24 h. The treatment protocol resulted in distinct groups of animals with respect to mortality rate, kinetics, and concentrations of a broad spectrum of pro- and anti-inflammatory endogenous mediators, intrapulmonary bacterial accumulation, and static lung compliance. In sublethally infected mice, pulmonary bacterial proliferation was controlled. Levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-10, interleukin-6, granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor (TNF) in plasma were elevated 3 h after infection exclusively. At 3 h, MCP-1, gamma interferon, and TNF were detected in extracts of pulmonary tissue or in bronchoalveolar lavage (BAL) fluid. Static lung compliance (C(st)) was transiently decreased at 12 h. In contrast, in lethally infected mice pulmonary bacterial proliferation was not contained. Concentrations of MCP-1, G-CSF, and TNF in plasma were maximal at 24 h, as were pulmonary MCP-1 levels. Lung myeloperoxidase activity was increased at 3, 12, and 24 h. C(st) was reduced after 3 h and did not reach control values at 24 h. Pulmonary cyclooxygenase-2 mRNA and eicosanoids in BAL fluid and plasma were elevated at 3 and 24 h. This study shows that polymicrobial peritonitis in mice leads to dose-dependent systemic and pulmonary inflammation accompanied by a decrease in lung compliance.

[Circulatory function and oxygenation during hemihepatectomy. Dopamine versus dopexamine]. / Kreislaufverhalten und Oxygenierung während Hemihepatektomien. Dopamin versus Dopexamin.

OBJECTIVE: The aim of this study was to compare low dose dopamine and dopexamine with respect to of liver-venous oxygen saturation, oxygen delivery and--demand, liver function tests and cardiocirculatory effects in the reperfusion period during a hemihepatectomy operation with occlusion of the liver hilus. METHODS: Twenty patients were studied in a randomised, doubleblind setting. They either received 2 micrograms/kg per min dopamine or 0.5 microgram/kg per min dopexamine perioperatively. For monitoring purposes a pulmonary artery and a liver venous catheter were placed. At four different time points hemodynamic parameter were assessed and blood samples were drawn. RESULTS: Significant changes between groups were found 5 min after opening the liver hilus for the cardiac index and the systemic oxygen delivery, as well as at the end of the operation for pulmonary shunt volume, which had increased more in the dopexamine group. No significant difference between liver venous oxygen saturation and liver function tests was found. CONCLUSION: Until more detailed studies concerning the influence of dopamine on the hepatic-splanchnic region during liver surgery are performed, dopexamine can not be considered superior to dopamine during these operations.

Surfactant protein A enhances the binding and deacylation of E. coli LPS by alveolar macrophages.

Surfactant protein (SP) A and SP-D are involved in multiple immunomodulatory functions of innate host defense partly via their interaction with alveolar macrophages (AMs). In addition, both SP-A and SP-D bind to bacterial lipopolysaccharide (LPS). To investigate the functional significance of this interaction, we first tested the ability of SP-A and SP-D to enhance the binding of tritium-labeled Escherichia coli LPS to AMs. In contrast to SP-D, SP-A enhanced the binding of LPS by AMs in a time-, temperature-, and concentration-dependent manner. Coincubation with surfactant-like lipids did not affect the SP-A-mediated enhancement of LPS binding. At SP-A-to-LPS molar ratios of 1:2-1:3, the LPS binding by AMs reached 270% of control values. Second, we investigated the role of SP-A in regulating the degradation of LPS by AMs. In the presence of SP-A, deacylation of LPS by AMs increased by approximately 2.3-fold. Pretreatment of AMs with phosphatidylinositol-specific phospholipase C had no effect on the SP-A-enhanced LPS binding but did reduce the amount of serum-enhanced LPS binding by 50%, suggesting that a cell surface molecule distinct from CD14 mediates the effect of SP-A. Together the results for the first time provide direct evidence that SP-A enhances LPS binding and degradation by AMs.

Early alterations in intracellular and alveolar surfactant of the rat lung in response to endotoxin.

The aim of this study was to characterize early ultrastructural, biochemical, and functional alterations of the pulmonary surfactant system induced by Salmonella minnesota lipopolysaccharide (LPS) in rat lungs. Experimental groups were: (1) control in vitro, 150 min perfusion; (2) LPS in vitro, 150 min perfusion, infusion of 50 microg/ml LPS after 40 min; (3) control ex vivo, 10 min perfusion; (4) LPS ex vivo, lungs perfused for 10 min from rats treated for 110 min with 20 mg/kg LPS intraperitoneally. Morphometry of type II pneumocytes showed that LPS increased stored surfactant. Lamellar bodies were increased in size, but decreased in numerical density, suggesting that giant lamellar bodies observed in LPS-treated lungs may result from fusion of normal bodies. Structural analysis of alveolar surfactant composition showed that LPS elicited an increase in lamellar body-like and multilamellar forms. Bronchoalveolar lavage (BAL) material from LPS-treated lungs was decreased in phospholipids. BAL bubble surfactometer analysis showed a reduction in hysteresis area caused by LPS. We conclude that LPS leads to alterations of intracellular and alveolar surfactant within 2 h: fusion of lamellar bodies, reduction in surfactant secretion, and changes in alveolar surfactant transformation, composition, and function, which may contribute to the development of respiratory distress.

[Mediastinal tumor and airway obstruction in general anesthesia. Case report and review of the literature]. / Mediastinaltumor und Luftwegsobstruktion unter Allgemeinanästhesie. Fallbeispiel und Literaturüberblick.

Case report of an acute airway obstruction during general anaesthesia by compression of the left main bronchus in an asymptomatic patient with unknown mediastinal mass. The patient was scheduled for a relief of a thyroid gland cyst. The compression occurred after uneventful induction of anaesthesia during the patient's positioning with flexed neck and elevated upper thorax on a pad. Increasing FiO2 from 0.5 to 1.0, repeated fiberoptic bronchoscopic examination and changing of the position of the endotracheal tube facilitated the operation. After reversal of the flexed neck position ventilation was normal. The intraoperatively suspected mediastinal tumour was confirmed by postoperative computerised tomography of thorax and neck. The teratoma was removed in toto in a second operation. In a review of the literature pathophysiological changes, preoperative assessment and anaesthetic management of patients with mediastinal tumour are discussed.