Procaine in Malignant Hyperpyrexia

The caffeine contracture of normal human muscle, which has been used as a model for malignant hyperpyrexia, is greatly potentiated by halothane. Prior administration of procaine markedly reduces the halothane-potentiated caffeine contracture, and procaine given at the height of the contracture induces relaxation. Lignocaine, on the other hand, produces a variable response and sometimes increases the contracture.The muscle from a patient with an inherited susceptibility to malignant hyperpyrexia contracted spontaneously with halothane alone, and this contracture was reversed by procaine.These experiments support the therapeutic use of procaine in malignant hyperpyrexia.     

Studies on the structures of the Tm, Sj, M1, Can, Sext and Hu blood group antigens

The Glycophorins (GPs = sialoglycoproteins) in erythrocyte membranes from various Black individuals, some of which exhibit the M1, Can, Sj, Tm, Sext and/or Hu antigens, and several Caucasian donors, including pooled fetal red cells, were studied. Using agglutination inhibition assays with GP fractions, GP fragments and chemically modified GPs as well as trypsin treatment of intact red cells, the antigens defined by anti-M1, anti-M+M1, anti-Can and anti-Tm sera were found to be located on the N-terminal tryptic peptide (T2, residues 1-31) of the major GP (GP A = MN sialoglycoprotein). Evidence was obtained that the N-terminal amino-acid residue, NeuNAc and/or (a) different sugar residue(s) are involved in the antigens. Amino-acid sequence and composition analyses excluded an amino-acid exchange within the N-terminal region (residues 1-31) of GP A. Carbohydrate analyses revealed the attachment of GlcNAc residues (up to about five, dependent on the strength of the above-mentioned antigens) to O-glycosidically linked oligosaccharides within the N-terminal portion (residues 1-31) of GP A. As judged from the carbohydrate compositions of peptides, the alteration of the O-glycosidic oligosaccharides is associated with a slight increase of the Gal and Fuc contents and a slight decrease of the NeuNAc level. Analyses of small, secondary cyanogen bromide and V8 proteinase peptides from the N-terminal region of GP A from Blacks, Caucasians and Caucasian fetal cells suggest that the variable attachment of small quantities of GlcNAc (about 0.03 to about 0.2 residues per peptide molecule) accounts, at least in part, for the polymorphisms detected by anti-Can and the original anti-Tm (serum Sheerin). Remarkably, the GlcNAc-containing O-glycosidic oligosaccharides occur only in small quantities, or not all at, within the positions 32-61 of GP A and the glycosylated domains of GP B and GP C.(ABSTRACT TRUNCATED AT 400 WORDS)     

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.     

A systematic screen for genes expressed in definitive endoderm by Serial Analysis of Gene Expression (SAGE)

Background  

The embryonic definitive endoderm (DE) gives rise to organs of the gastrointestinal and respiratory tract including the liver, pancreas and epithelia of the lung and colon. Understanding how DE progenitor cells generate these tissues is critical to understanding the cause of visceral organ disorders and cancers, and will ultimately lead to novel therapies including tissue and organ regeneration. However, investigation into the molecular mechanisms of DE differentiation has been hindered by the lack of early DE-specific markers.