On-line enzyme activity determination using the stopped-flow technique: application to laccase activity in pulp mill waste-water treatment

An automated system for on-line measurement of enzyme activity is proposed. The system uses a flow injection manifold in the stopped-flow mode to measure initial reaction rates. The time during which the flow is halted is selected in such a way as to optimise the enzyme/substrate ratio for the correct determination of activity values. The proposed system was used to determine the activity of laccase produced by the fungus Trametes versicolor immobilised on nylon in a fixed-bed reactor used for treating pulp mill waste water. Received: 17 February 1997 / Received revision: 23 April 1997 / Accepted: 27 April 1997     

HLA-DR2-associated Dw subtypes correlate with RFLP clusters: most DR2 IDDM patients belong to one of these clusters

The incidence of arthritis and the antibody response to mouse and to rat type 11 collagen after immunization with native rat type II collagen was studied in different mouse strains, including wild mouse-derived strains belonging to the H-2^p/H-2^q family. High serum levels of antibodies to mouse and rat type II collagen were seen only in H-2^q mice, whereas mice belonging to the p, w3, w5, and w17 haplotypes displayed low type II collagen-specific antibody responses. Mice from three different H-2^q-carrying strains (DBA/1, NFR/N, and B10.G) with different non-major histocompatibility complex genes were all susceptible to collagen arthritis, but they displayed a varying incidence of arthritis and varying clinical features. No arthritis was seen in non-H-2^q mice, except in the B10.CAS2 strain where a few mice developed arthritis despite very low serum levels of type II collagen-specific antibodies. We conclude that small differences in the A chain of class II transplantation antigens are of importance for the development of arthritis and for the stimulation of a high response after immunization with type 11 collagen.Abbreviations used in this paper ELISA enzyme-linked immunosorbent assay - PBS phosphate-buffered saline - Ig immunoglobulin - MHC major histocompatibility complex     

Le festucetum hystricis,une association montagnarde nouvelle de l'Espagne

Sans résuméReçu par la rédaction le 31.I.1954.     

Recombinant Families Locate the Gene for Non-Type I Cystinuria between Markers C13 and D19S587 on Chromosome 19q13.1

Cystinuria is an autosomal recessive aminoaciduria in which three urinary phenotypes have been described. The gene responsible for type I, SLC3A1, encodes the amino acid transporter rBAT. This gene is not responsible for types II or III. Recently the type III locus (CSNU3) was mapped by two groups to overlapping 6-Mb regions on chromosome 19q. In the present study, we restrict the critical region for non-type I cystinuria to 2.4 Mb by recombination analysis in Italian, German, and Spanish families. For this purpose, we have used the microsatellite markers described in the region plus new microsatellites that we have developed. Our results locate the non-type I cystinuria gene in an interval flanked by the markers C13 and D19S587, which are about 2.8 cM apart.     

Evolution of organic matter in a full-scale composting plant for the treatment of sewage sludge and biowaste by respiration techniques and pyrolysis-GC/MS

A full-scale composting plant treating in two parallel lines sewage sludge and the source-selected organic fraction of municipal solid waste (OFMSW or biowaste) has been completely monitored. Chemical routine analysis proved not to be suitable for an adequate plant monitoring in terms of stabilization and characterization of the process and final compost properties. However, the dynamic respiration index demonstrated to be the most feasible tool to determine the progression of the degradation and stabilization of organic matter for both sewage sludge and OFMSW lines. Both lines exhibited an important degree of stabilization of organic matter using rapid and cumulative respiration indices. Pyrolysis-GC/MS was applied to the most important inputs, outputs, and intermediate points of the plant. It proved to be a powerful tool for the qualitative characterization of molecular composition of organic matter present in solid samples. A full characterization of the samples considered is also presented.     

Detection by chemical cross-linking of bovine brain synapsin I self-association.

Synapsin I is believed to play an important role in the regulation of neurotransmitter release, since it is able to bind to synaptic vesicles, to the cytoskeleton and to membrane proteins; in addition, it bundles F-actin and microtubules. These properties, which are controlled by phosphorylation, could be explained if synapsin has different and multiple binding sites or if synapsin I is able to form polymers by self-association. In this study we present experimental evidence that synapsin I at low concentration forms self-associated dimers, as revealed after mild treatments with cross-linking agents. We have especially studied here the effects of copper/o-phenanthroline, a zero-length cross-linking agent which forms covalent links by oxidative formation of S-S bridges between adjacent cysteines. The time course and concentration-dependence of synapsin-dimer formation are studied; interestingly, these experiments could suggest a different behaviour of the two polypeptides. Limited proteolysis of phosphorylated synapsin I by V8 protease, alpha-chymotrypsin or collagenase, performed on the isolated dimer and monomer, allows us to localize tentatively in the central hydrophobic core of the molecule the cysteine residues the oxidation of which by copper/o-phenanthroline gives rise to synapsin dimers.     

Induction of triggering receptor expressed on myeloid cells (TREM-1) in airway epithelial cells by 1,25(OH)₂ vitamin D₃

The airway epithelium plays a role in host defense through the binding of innate immune receptors, which leads to the activation of inflammatory mediators, including antimicrobial peptides. The active form of vitamin D, 1,25(OH)(2)D(3), induces the expression of the antimicrobial peptide LL-37 in both myeloid cells and airway epithelial cells (AEC). Here, we demonstrate that mRNA encoding triggering receptor expressed on myeloid cells (TREM)-1 was induced up to 12-fold by 1,25(OH)(2)D(3) in normal human bronchial epithelial (NHBE) cells and in well-differentiated cultures of six airway epithelial cell lines from patients with cystic fibrosis and healthy individuals. TREM-2 and DAP12 were also expressed in airway cultures, but not induced by vitamin D. Induction occurs through a vitamin D response element identified in its proximal promoter region, and was regulated by PU.1 expressed in the AEC. Activation of TREM-1 by a cross-linking antibody led to an induction of both human β-defensin-2 and TNF-α mRNA, demonstrating its functionality in these cells. Our results expand on the role played by the airway epithelium in innate immunity and suggest that vitamin D can modulate the innate immune defense of the airway epithelium, and could potentially be developed as an adjunctive therapy for airway infections.