The role of nonactivated and interferon-gamma activated monocytes in regulating normal and SLE patient B cell responses to TNP-Brucella abortus

We have previously characterized the human B cell response to trinitrophenol (TNP)-Brucella abortus (Ba) response as being T cell independent. In this report we examine the role of monocytes in the TNP-Ba antibody response of human peripheral blood mononuclear cells (PBMC). Depletion of monocytes by sequential adherence to plastic and Sephadex G-10 passage did not result in decreased plaque-forming cell responses to TNP-Ba, suggesting that monocytes were not required. On the contrary monocytes were probably inhibitory because their removal resulted in enhanced responses. This was confirmed by showing that adding monocytes back reconstituted the inhibition. When interferon-gamma (IFN-gamma), a potent activator of monocytes, was added to TNP-Ba-driven PBMC cultures, marked inhibition (greater than 90%) of the responses ensued. This IFN-gamma-mediated suppression was monocyte dependent because it was completely abrogated by monocyte, but not T cell depletion. Previously, we described a concanavalin A (Con A), T cell inhibition pathway of the TNP-Ba response. Both the Con A and IFN-gamma pathways were tested for their ability to inhibit systemic lupus erythematosus (SLE) patient responses to TNP-Ba. The B cell response of SLE patients was inhibitable by both pathways. In all of the patients, the inhibition was complete (greater than 95%) when IFN-gamma was added to the cultures. In the presence of Con A, greater than 95% inhibition was observed in six of 10 patients, the remainder being inhibited to a lesser extent. Thus the hyperactive B cells from SLE patients can be down-regulated, particularly in the presence of IFN-gamma.     

L’electromyographie du penis: Une nouvelle exploration du muscle lisse caverneux et de son controle neurologique?

The authors have investigated the electrical activity of corpus cavernous, first according to Wagner and Gerstenberg’ method, then, since one year, according to Stief method, in the basal state and following intracavernosal injection of vasoactive agents, or following various stimulation tests. They have found again the electrical activity described by these authors, but have been confronted with the difficulty in quantifying the data. Specially single potential analysis seems to them little reliable and reproducible for an objective interpretation. At this stage of their experience, they test two simpler criteria interpretation: the richness of the electrical activity, and the reactivity of the recording to various stimulations. Their preminary results suggest a correlation between those criteria and the state of the autonomic nervous system of the penis.     

Complete sequences of the rRNA genes of Drosophila melanogaster

In this, the first of three papers, we present the sequence of the ribosomal RNA (rRNA) genes of Drosophila melanogaster. The gene regions of D. melanogaster rDNA encode four individual rRNAs: 18S (1,995 nt), 5.8S (123 nt), 2S (30 nt), and 28S (3,945 nt). The ribosomal DNA (rDNA) repeat of D. melanogaster is AT rich (65.9% overall), with the spacers being particularly AT rich. Analysis of DNA simplicity reveals that, in contrast to the intergenic spacer (IGS) and the external transcribed spacer (ETS), most of the rRNA gene regions have been refractory to the action of slippage-like events, with the exception of the 28S rRNA gene expansion segments. It would seem that the 28S rRNA can accommodate the products of slippage-like events without loss of activity. In the following two papers we analyze the effects of sequence divergence on the evolution of (1) the 28S gene "expansion segments" and (2) the 28S and 18S rRNA secondary structures among eukaryotic species, respectively. Our detailed analyses reveal, in addition to unequal crossing-over, (1) the involvement of slippage and biased mutation in the evolution of the rDNA multigene family and (2) the molecular coevolution of both expansion segments and the nucleotides involved with compensatory changes required to maintain secondary structures of RNA.      

Echocardiographic assessment and percutaneous closure of multiple atrial septal defects

Percutaneous coronary intervention can be associated with distal embolization of thrombotic material causing myocardial necrosis and infarction. We discuss the role of intravascular imaging to guide the use of a distal protection device by describing the outcome of a young woman presenting with non-ST elevation myocardial infarction. Coronary angiography demonstrated an isolated minor stenosis in the proximal left anterior descending coronary artery with slight haziness beyond the lesion. Intravascular ultrasound confirmed an extensive thrombus overlying a bulky atherosclerotic plaque. A distal filter wire was therefore successfully used to reduce the risk of distal embolization. The use of intravascular ultrasound in patients presenting with acute coronary syndrome may reveal large thrombi that are difficult to image using conventional angiographic techniques. Intravascular ultrasound can therefore be used as a tool to select lesions requiring distal protection.