Evaluation of a rapid cultural method for identification of salmonellas in naturally contaminated veterinary samples©

Three thousand and forty-two samples of post-mortem tissues, environmental swabs, animal feed ingredients and eggs were examined by conventional methods and by a simple rapid culture method. The rapid method gave reliable presumptive identification of salmonella contamination within 48 h of the start of culture. The rapid method also showed enhanced sensitivity for detection of salmonellas, in most types of sample, particularly those taken in poultry houses and hatcheries where high levels of competitive faecal bacteria are present.     

Adrenergic stimulation of membrane protein phosphorylation in human erythrocytes

Adrenergic modification of membrane protein phosphorylation was studied in intact human erythrocytes. Micromolar norepinephrine increased ³²P incorporation into Band 2 by 70%, and into Band 3 by 40%. Phosphorylation levels observed with a series of specific agonists and antagonists suggest that an α-adrenergic receptor is involved in this effect. The mechanism of linkage between this receptor and protein phosphorylation does not appear to involve modulation of intracellular concentrations of ATP, cyclic AMP, or cyclic GMP.     

Median nerve compression and trigger finger in the mucopolysaccharidoses and related diseases.

Patients with Hurler's syndrome (MPS-1H), I-cell disease (ML-II) and pseudo-Hurler's syndrome (ML-III) had median nerve compression and triggering of the fingers which limited finger extension. To our knowledge, this combination has not been reported previously in patients with mucopolysaccharidoses and related disorders. In all of our 3 cases the median nerve was compressed by thickened flexor tenosynovium. Synovectomy and resection of the volar carpal ligament improved the hand function in all, including the mentally retarded patient with Hurler's syndrome. Release of the fibroosseous tunnel in two patients was followed by an increased range of motion (but not full extension). A fourth patient, without a mucopolysaccharide storage disorder, also had the combination of trigger finger and carpal tunnel syndrome.     

Bromotrifluoroacetone alkylates hemoglobin at cysteine β93

The site of alkylation of hemoglobin by bromotrifluoroacetone has been determined by peptide mapping, using a stable radioactive label for the trifluoroacetonyl function. This study and ¹H and ¹⁹F-nmr experiments confirm the site of modification to be the β93 cysteine found in the βT10 tryptic peptide fragment of the modified hemoglobin.     

Curcumin activation of a bacterial mechanosensitive channel underlies its membrane permeability and adjuvant properties

Curcumin, a natural compound isolated from the rhizome of turmeric, has been shown to have antibacterial properties. It has several physiological effects on bacteria including an apoptosis-like response involving RecA, membrane permeabilization, inhibiting septation, and it can also work synergistically with other antibiotics. The mechanism by which curcumin permeabilizes the bacterial membrane has been unclear. Most bacterial species contain a Mechanosensitive channel of large conductance, MscL, which serves the function of a biological emergency release valve; these large-pore channels open in response to membrane tension from osmotic shifts and, to avoid cell lysis, allow the release of solutes from the cytoplasm. Here we show that the MscL channel underlies the membrane permeabilization by curcumin as well as its synergistic properties with other antibiotics, by allowing access of antibiotics to the cytoplasm; MscL also appears to have an inhibitory role in septation, which is enhanced when activated by curcumin.     

Cloning and nucleotide sequence of the Streptomyces coelicolor gene encoding glutamine synthetase

The Streptomyces coelicolor glutamine synthetase (GS) structural gene (glnA) was cloned by complementing the glutamine growth requirement of an Escherichia coli strain containing a deletion of its glnALG operon. Expression of the cloned S. coelicolor glnA gene in E. coli cells was found to require an E. coli plasmid promoter. The nucleotide sequence of an S. coelicolor 2280-bp DNA segment containing the glnA gene was determined and the complete glnA amino acid sequence deduced. Comparison of the derived S. coelicolor GS protein sequence with the amino acid sequences of GS from other bacteria suggests that the S. coelicolor GS protein is more similar to the GS proteins from Gram-negative bacteria than it is with the GS proteins from two Gram-positive bacteria, Bacillus subtilis and Clostridium acetobutylicum.     

Structural requirements of carbohydrates to bind Agaricus bisporus lectin

Galbeta1-3GalNAc (T-disaccharide) and related molecules were assayed to describe the structural requirements of carbohydrates to bind Agaricus bisporus lectin (ABL). Results provide insight into the most relevant regions of T-disaccharide involved in the binding of ABL. It was found that monosaccharides bind ABL weakly indicating a more extended carbohydrate-binding site as compared to those involvedin the T- disaccharide specific lectins such as jacalin and peanut agglutinin. Lacto-N-biose (Galbeta1-3GlcNAc) unlike T-disaccharide, is unable to inhibit the ABL interaction, thus showing the great importance of the position of the axial C-4 hydroxyl group of GalNAc in T-disaccharide. This finding could explain the inhibitory ability of Galbeta1-6GlcNAc and lactose because C-4 and C-3 hydroxyl groups of reducing Glc, respectively, occupy a similar position as reported by conformational analysis. From the comparison of different glycolipids bearing terminal T-disaccharide bound to different linkages, it can be seen than ABL binding is even more impaired by an adjacent C-6 residual position than by the anomeric influence of T-disaccharide. Furthermore, the addition of beta-GlcNAc to the terminal T-disaccharide in C-3 position of Gal does not affect the ABL binding whereas if an anionic group such as glucuronic acid is added to C-3, the binding is partially affected. These findings demonstrate that ABL holds a particular binding nature different from that of other T-disaccharide specific lectins.