Hormonal induction of steroid sulphatase in the mouse

By comparing steroid sulphatase levels per se, and also ratios to alpha-galactosidase, in 6 sets of mice - normal females, entire and castrated males both with and without exogenous testosterone administration - we obtained support for the contention that induction of this enzyme is in part controlled by male hormones.     

Subcutaneous transposition of the spleen enhances the survival rate following 90% hepatectomy in rats

Summary The effects of subcutaneous transposition of the spleen (STS) on the survival rate following 90% hepatectomy were investigated in rats. The survival rate was significantly higher in the STS group than in the non-STS group. Light microscopy enabled us to note that congestion in the terminal portal veins and sinusoids occurred either slightly earlier or to a higher degree in the non-STS group.     

Effects of acetaldehyde and/or ethanol on neutral amino acid transport systems in microvillous brush border membrane vesicles prepared from human placenta

Summary At 20 mM of acetaldehyde, the activities of three transport systems of L-alanine distinguished by the difference in their cation dependence, namely 1) Na⁺-specific, 2) Li⁺-dependent, and 3) Na⁺-independent systems, were significantly reduced in a similar manner. Only the Li⁺-dependent system was selectively inhibited at toxic concentrations of acetaldehyde and ethanol.     

Neutrophil influx into an inflammatory site inhibited by a soluble homing receptor-IgG chimaera

Neutrophil-mediated inflammation is involved in a number of human clinical manifestations, including the adult respiratory distress syndrome, multi-organ failure and reperfusion injury. One way of inhibiting this type of inflammatory response would be to block competitively the adhesive interactions between neutrophils and the endothelium adjacent to the inflamed region. The lectin-containing murine adhesion molecule gp90MEL, the homing receptor, is found on all leukocytic cells, including neutrophils. MEL 14, a monoclonal antibody directed against this adhesion molecule, blocks lymphocyte traffic to lymph nodes and extravasation of neutrophils from blood to inflammatory sites. Here we show that administration to mice of a soluble immunoglobulin chimaera containing the murine homing receptor extracellular domain significantly decreases the number of neutrophils that migrate to the peritoneum in response to the inflammatory irritant thioglycollate. These results indicate that soluble forms of a single type of adhesion molecule, the homing receptor, could be clinically effective compounds for the inhibition of neutrophil-mediated inflammation.     

Presence of NAD pyrophosphorylase in skeletal muscle in dystrophic mice

Summary NAD pyrophosphorylase (ATP:NMN adenylyltransferase) activity has been measured in the skeletal muscle of dystrophic mice. The amount of this enzyme in the dystrophic mice, as determined by three different methods, was about one half of that in the controls. In addition, the concentration of ATP was too low to be detected in crude extracts of dystrophic mouse skeletal muscle, which were prepared using Tris buffer alone or Tris buffer containing either 3 M KCl, or 1 mM PMSF.     

The stability of a complex social system

Analyzing communication data within a social structure represented by a wholesale agricultural market demonstrates the utility of network analysis techniques for identifying systems. A representation of these data in matrix form permits exploration of the stability properties of the system. The stability analyses lend some support for theoretical arguments pertaining to the conditions leading to system equilibrium.     

Somatic variation in micropropagated clones ofCichorium intybus

Summary An experiment aiming to establish whether temporary or persistet somatic variation can arise in clones obtained in vitro by micropropagation has been performed onCichorium intybus. The results point out that persistent modifications of the phenotype can be observed after six cycles of cloning and that when the length of the cloning period is varied these appear to be differential responses of the same genotype to the micropropagation.     

Involvement of prolyl endopeptidase in ascidian fertilization

Inhibitory effects on fertilization of the ascidian of three benzyloxycarbonyl(Z)-aminoacyl prolinals and Z-Gly-Pro-chloromethyl ketone added before and after insemination were examined. The results suggest that the prolyl endopeptidase is involved in the process of fertilization, especially in a process taking place between chorion elevation and cell cleavage.