The combination of a Rotaflow centrifugal pump and Lilliput 2 ECMO oxygenator in pediatric ECMO circuits improved durability and reduced circuit-induced hemolysis. This improvement may be due to the low priming volume, the oxygenator's plasma leakage resistance, the suspended rotor of the centrifugal pump, or a combination of these factors.

A gyrB gene from Streptomyces sphaeroides, a producer of novobiocin, has been cloned in Streptomyces lividans, where it conferred resistance to novobiocin. The Streptomyces gyrB gene was sufficiently similar to a Bacillus subtilis gyrB probe to be specifically recognized during Southern analysis. Partial purification of DNA gyrase by affinity chromatography revealed the presence of two such activities (differing in their responses to novobiocin) in the clone. The product of the cloned gene, a novobiocin‐resistant DNA gyrase B subunit, was identified in vitro by coupled transcription–translation as a 79‐kd protein.

No abstract

The glycocalyx covering the endothelium is shed during ischemia and reperfusion. The shedding is accompanied by increased levels of the glycocalyx component syndecan-1 in the circulation. Our aim was to compare plasma levels of syndecan-1 in patients undergoing coronary artery bypass grafting (CABG), with or without the use of cardiopulmonary bypass (CPB). Syndecan-1 plasma concentrations were measured in patients undergoing CABG on-pump (nA =A 22) or off-pump (nA =A 22). The syndecan-1 concentration increased significantly from 29.5 +/- 4.6 ng/mL at baseline to 98.7 +/- 9.8 ng/mL (pA

The production of different transcripts (transcript heterogeneity) is a feature of many genes that may result in phenotypic variation. Several mechanisms, that occur at both the DNA and RNA level have been shown to contribute to this transcript heterogeneity in mammals, all of which involve either the rearrangement of sequences within a genome or the use of alternative signals in linear, contiguous DNA or RNA. Here we describe tissue-specific repetition of selective exons in transcripts of a rat gene (SA) with a normal exon-intron organization. We conclude that nonlinear mRNA processing can generate tissue-specific transcripts.

The two circuits exhibited a comparable degree of in vivo biocompatibility.

SummaryThe complement system can be activated via the lectin pathway by the recognition molecules mannose-binding lectin (MBL) and the ficolins. Ficolin-2 exhibits binding against a broad range of ligands, including biomaterials in vitro, and low ficolin-2 levels are associated with increased risk of infections. Thus, we investigated the biocompatibility of the recognition molecules of the lectin pathway in two different types of cardiopulmonary bypass circuits. Bloods were drawn at five time-points before, during and postoperatively from 30 patients undergoing elective cardiac surgery. Patients were randomized into two groups using different coatings of cardiopulmonary bypass circuits, Phisio® (phosphorylcholine polymer coating) and Bioline® (albumin-heparin coating). Concentrations of MBL, ficolin-1, −2 and −3 and soluble C3a and terminal complement complex (TCC) in plasma samples were measured. Ficolin-3-mediated complement activation potential was evaluated with C4, C3 and TCC as output. There was no significant difference between the two circuit materials regarding MBL, ficolin-1 and −3. In the Bioline® group the ficolin-2 levels decreased significantly after initiation of surgery (P < 0·0001) and remained reduced throughout the sampling period. This was not seen for Phisio®-coated circuits. Ficolin-3-mediated complement activation potential was reduced significantly in both groups after start of operation (P < 0·0001), whereas soluble C3a and TCC in the samples were increased (P < 0·0001). Ficolin-2 was depleted from plasma during cardiac surgery when using heparin-coated bypass circuits and did not reach baseline level 24 h postoperation. These findings may have implications for the postoperative susceptibility to infections in patients undergoing extracorporeal circulation procedures.

A novobiocin producer, Streptomyces sphaeroides, contains two genes, designated gyrBS and gyrBR, that encode novobiocin-sensitive and -resistant DNA gyrase B proteins, respectively. The cloning of gyrBR was reported earlier; here, we describe the cloning of gyrBS. Both genes have been sequenced (the deduced products of gyrBS and gyrBR have M(r) values of 87.6K and 86.5K, respectively) and their transcripts have been mapped. Downstream of gyrBS, and co-transcribed with it, is the sole gyrA gene (encoding DNA gyrase A protein). By constructing hybrid gyrB genes, using fragments of gyrBS and gyrBR, a specific portion of the N-terminal domain of the gyrase B protein (corresponding to amino acid residues 134-256 of Escherichia coli gyrase B) has been implicated in the binding of novobiocin.