Carbonic anhydrase activity in the vas deferens of the cotton leafworm - Spodoptera littoralis (Lepidoptera: Noctuidae) controlled by circadian clock.

The male reproductive tract of Lepidoptera is an ideal model for the study of the physiological role of peripheral clocks in insects. The latter are significant in the generation and coordination of rhythmic phenomena which facilitate the initial stages of sperm capacitation. This process requires the maintenance of pH in the upper vas deferens (UVD) aided by, among others, H+-ATPase. Our aim was to determine the potential involvement of carbonic anhydrase (CA) in this process, an enzyme tasked with generating protons subsequently utilized by H+-ATPase to acidify the UVD milieu in S. littoralis, during the time when the lumen of this organ is filled with sperm. We attempted to answer the question whether CA activity can be controlled by the biological oscillator present in the male reproductive tract of the cotton leafworm. Using PAGE zymography, the presence of CA was demonstrated in the UVD wall, but not in the luminal fluid nor in the sperm. Using histochemistry, it was shown that CA is active in the UVD epithelium, and that this activity varies throughout the day and is most likely controlled by an endogenous biological clock. Conversely, the application of CA inhibitors, acetazolamide and sodium thiocyanate, in conjunction with an analysis of H+-ATPase activity in the acidification the UVD environment shows that CA most likely does not play a direct role in the regulation of the pH in this organ.

Structure of the O-specific polysaccharide of Hafnia alvei PCM 1196.

An acidic O-specific polysaccharide was isolated from Hafnia alvei PCM 1196 lipopolysaccharide and studied by sugar and methylation analyses along with one- and two-dimensional 1H and 13C NMR spectroscopy, including NOESY and HMBC experiments. The following structure of the pentasaccharide repeating unit was established: -->4)-alpha-D-GalpA-(1-->3)-beta-D-GlcpNAc-(1-->2)-beta-D-Galp-(1-->6)-alpha-D-Glcp-(1-->6)-alpha-D-GlcpNAc-(1-->.

Rare, suppurative pulmonary infection caused by Nocardiopsis dassonvillei recognized by glycolipid markers.

An opportunistic actinomycete was isolated as the only etiological agent of a severe, suppurative pulmonary infection. The strain was rapidly recognised as Nocardiopsis by the taxonomically important and immunologically active glycolipid markers (G1 and G2). Identification of the clinical isolate, from a group of actinomycetes mainly known as soil habitants, was definitely proved by chemotaxonomic studies (cell wall/sugar, phospholipid and fatty acid types) as well as by genomic data (GC content, DNA-DNA reassociation). The level of DNA-DNA homology of the clinical actinomycete, in comparison with other reference members of this genus, revealed the highest (88%) relatedness to Nocardiopsis dassonvillei. The results confirmed the value and generic specificity of glycolipid markers from Nocardiopsis, the first time used for rapid recognition of a clinical strain causing a nocardiosis-like disease.

Serological characterisation of anti-endotoxin sera directed against the conjugates of oligosaccharide core of Escherichia coli type R1, R2, R3, J5 and Salmonella Ra with tetanus toxoid.

The covalent conjugates of oligosaccharide core: Escherichia coli type R1, R2, R3, J5 and Salmonella Ra with tetanus toxoid have been prepared using reaction of reductive amination. The neoglycoconjugates were good immunogens in rabbits yielding a high level of anti-lipopolysaccharide antibodies of IgG class. The antibodies were used to examine the possibility of their reactions with smooth lipopolysaccharides. We have found that all antisera were able to react with the lipopolysaccharide molecules of identical or related core type, possessing core oligosaccharides substituted with O-specific chains. These reactions were shown in both the ELISA assay and the immunoblotting test.

The sensitivity of Hafnia alvei strains to the bactericidal effect of serum.

Most Hafnia alvei strains are sensitive to the bactericidal action of normal bovine serum (NBS) as well as to a serum in which the alternative pathway of complement activation has been thermally blocked. Introduction of polysaccharides (PS) to NBS lowers the bactericidal effect. In a serum in which the alternative pathway of complement activation is blocked, PS completely cancels the bacterial effect.

Structural and serological characterization of Hafnia alvei lipopolysaccharide core region.

The structures and serological activities of core oligosaccharide of Hafnia alvei strains have been investigated. Methylation analysis, NMR spectroscopy and various specific degradation procedures were the principal methods used. It is concluded that, core hexasaccharides are identical in the lipopolysaccharides tested and are built of two glucose, three heptose and one 2-keto-3-deoxyoctulosonic acid residues. The antiserum raised against the ATCC13337 oligosaccharide core-tetanus toxoid conjugate cross-reacted strongly with all lipopolysaccharides used as antigens in ELISA test, suggesting that this core region is the common structure in the Hafnia genus.

Genetic properties of the Salmonella enteritidis R404 plasmid aggregate I. Conjugational separation of different derivative plasmid aggregates and their genetic properties.

Conjugational transfer of R404 factor, found in Salmonella enteritidis strain, was examined. Six derivative forms differing in resistance pattern were isolated. The manner of conjugational separation during transfer of R404 factor from E. coli to E. coli strain was the same as from the original strain of S. enteritidis to E. coli strain. During following conjugation, all isolated forms except one, could give forms differing in a resistance pattern from the parenteral ones. This one form, from which different conjugational forms could not be separated, was assumed to be a single plasmid and was designated pCK2. All other forms, including the original R404 factor were assumed to be plasmid aggregates.