This review describes the present state of a project to identify and characterize novel nervous system proteins by using monoclonal antibodies (mAbs) against the Drosophila brain. Some 1,000 hybridoma clones were generated by injection of homogenized Drosophila brains or heads into mice and fusion of their spleen cells with myeloma cells. Testing the mAbs secreted by these clones identified a library of about 200 mAbs, which selectively stain specific structures of the Drosophila brain. Using the approach "from antibody to gene", several genes coding for novel proteins of the presynaptic terminal were cloned and characterized. These include the "cysteine string protein" gene (Csp, mAb ab49), the "synapse-associated protein of 47 kDa" gene (Sap47, mAbs nc46 and nb200), and the "Bruchpilot" gene (brp, mAb nc82). By a "candidate" approach, mAb nb33 was shown to recognize the pigment dispersing factor precursor protein. mAbs 3C11 and pok13 were raised against bacterially expressed Drosophila synapsin and calbindin-32, respectively, after the corresponding cDNAs had been isolated from an expression library by using antisera against mammalian proteins. Recently, it was shown that mAb aa2 binds the Drosophila homolog of "epidermal growth factor receptor pathway substrate clone 15" (Eps15). Identification of the targets of mAbs na21, ab52, and nb181 is presently attempted. Here, we review the available information on the function of these proteins and present staining patterns in the Drosophila brain for classes of mAbs that either bind differentially in the eye, in neuropil, in the cell-body layer, or in small subsets of neurons. The prospects of identifying the corresponding antigens by various approaches, including protein purification and mass spectrometry, are discussed.

T2*-weighted perfusion imaging exploits the susceptibility-mediated signal intensity loss of a first-pass bolus of gadopentetate dimeglumine within the capillary bed. First-pass perfusion imaging of breast lesions is feasible. It is promising in the differentiation of benign from malignant, rapidly enhancing lesions.

Mitochondria are involved in the development of organ failure in critical care diseases. However, the mechanisms underlying mitochondrial dysfunction are not clear yet. Inducible hemoxygenase (HO-1), a member of the heat shock protein family, is upregulated in critical care diseases and considered to confer cytoprotection against oxidative stress. However, one of the products of HO-1 is Fe 2 þ which multiplies the damaging potential of reactive oxygen species catalyzing Fenton reaction. The aim of this study was to clarify the relevance of free iron metabolism to the oxidative damage of the liver in endotoxic shock and its impact on mitochondrial function. Endotoxic shock in rats was induced by injection of lipopolysaccharide (LPS) at a dose of 8 mg/kg (i.v.). We observed that the pro-inflammatory cytokine TNF-a and the liver necrosis marker aspartate aminotransferase were increased in blood, confirming inflammatory response to LPS and damage to liver tissue, respectively. The levels of free iron in the liver were significantly increased at 4 and 8 h after onset of endotoxic shock, which did not coincide with the decrease of transferrin iron levels in the blood, but rather with expression of the inducible form of heme oxygenase (HO-1). The proteins important for sequestering free iron (ferritin) and the export of iron out of the cells (ferroportin) were downregulated facilitating the accumulation of free iron in cells. The temporarily increased concentration of free iron in the liver correlated with the temporary impairment of both mitochondrial function and tissue ATP levels. Addition of exogenous iron ions to mitochondria isolated from control animals resulted in an impairment of mitochondrial respiration similar to that observed in endotoxic shock in vivo. Our data suggest that free iron released by HO-1 causes mitochondrial dysfunction in pathological situations accompanied by endotoxic shock.

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The objective of this study was to investigate early effects of peritoneal inflammation on the mitochondrial function in the vital organs, liver and kidney, and their relation to inflammatory and oxidative stress mediators. The study was performed on 14 domestic pigs. Peritoneal inflammation was induced in anesthetized pigs after a midline laparotomy by autologous feces. Fluid resuscitation maintained a MAP above 60 mmHg. Animals were sacrificed 12 h later, and tissue samples were obtained to determine mitochondrial function, mRNA levels of relevant genes [inducible NO synthase (iNOS), inducible HO (HO-1), tumor necrosis factor-alpha (TNF-alpha)], generation of reactive oxygen species (ROS), and HO-1 activity. We found impaired mitochondrial function in both liver and kidney, based on decreased state 3 respiration in the liver and increased states 2 and 4 respiration in the kidney at 12 h. This was accompanied by increased TNF-alpha protein in the blood and up-regulation of TNF-alpha mRNA in the liver. Free iron was elevated in the liver but not in the kidney. In the kidney, mitochondrial ROS production was increased. Nitric oxide levels in blood remained unchanged, corresponding to unchanged levels of iNOS mRNA expression in liver and kidney. Similarly, HO-1 mRNA and heme oxygenase (HO)-activity were unchanged. The inflammatory response in the absence of characteristic septic symptoms was not associated with morphological organ damage at this early time point. Peritoneal inflammation in pigs caused mitochondrial dysfunction in liver and kidney, preceding signs of organ damage. We did not find proof that mitochondrial dysfunction was due to increased levels of either nitric oxide (NO) or products of HO, but it was accompanied by increased levels of oxidative stress markers.