Abstract: Method for detecting Campylobacter by PCR detection of DNA sequence highly conserved between species lari, coli, jejuni and upsaliensis. Speciation between these four is possible as the PCR product is differentially cleaved by restriction endonucleases.

Abstract: Method for detecing Campylobacter by PCR detection of DNA sequence, highly conserved between species lari, coli, jejuni and upsaliensis. Speciation between these four is possible as the PCR product is differentially cleaved by restriction endonucleases.

Abstract: A pharmaceutical composition for use in the prophylaxis or treatment of pathological conditions resulting from the presence of superoxide radicals, comprising a manganese-superoxide dismutase (MnSOD) enzyme and a pharmaceutically acceptable excipient. The MnSOD enzyme is in native form and has substantially the amino acid sequence of SEQ ID NO: 17 or SEQ ID NO: 29 and is free of pyrogens consisting of macromolecular substances native to Bacillus Stearothermophilus (BS) or Bacillus Caldotenax (BC). Processes for producing the novel pharmaceutical composition and a method for the prophylaxis or treatment of pathological conditions resulting from the presence of superoxide radicals utilizing the novel composition are also disclosed.

Abstract: Expression vector for expressing the E. coli a polypeptide other than E. coli malate dehydrogenase coded for by a DNA coding sequence. The vector includes a DNA coding for the polypeptide and also includes an initiation codon wherein the DNA sequence is operatively linked to an upstream sequence located upstream of the initiation codon and which is capable of controlling expression of the polypeptide. The upstream sequence consists on the 285 base pair sequence defined by SEQ ID NO:3. A process for expressing a polypeptide by culturing a host strain of E. coli transformed with an expression vector of the invention is also provided.

Abstract: An ultrasonic field is used to manipulate biological cells or other particles in fluid suspension. A cavity is bounded by a thin plastics wall and excitation is confined to a single acoustic mode to displace the cells radially. The resulting column of cells can be transported more easily than the radially diffuse bands produced in earlier apparatus.

Abstract: A method of degrading an organic nitrogen compound to its reduction products, in which the compound is caused to react with a reducing agent in the presence of a complex of a corrin containing a metal-centered ring system. Preferred complexes are cobalt-centered hydrolysis products of Vitamin B12, such as cobyrinic acid, and in one embodiment these complexes are immobilised on a substrate. Using the method environmental pollutants such as nitrobenzenes may be rapidly reduced.

Abstract: A method for the estimation of a salicylate in a sample is characterized by enzymatically converting the salicylate to a catechol by the action of a salicylate mono-oxygenase enzyme on the salicylate in the presence of a reduced pyridine nucleotide, reacting the catechol with a compound selected from compounds of formula I or amine or phenolic compounds of formulae II, III or IV ##STR1##

Abstract: A fluid densitometer is constructed using loudspeaker technology. The loudspeaker diaphragm carries a fluid sample chamber. The increased mass loading causes a shift in resonant frequency of the loudspeaker when driven in positive feedback. With suitable calibration the shift in frequency provides a measure of the density of the fluid sample. In a modification, two loudspeakers are mounted back to back with the opposing diaphragms defining a sample chamber.

Abstract: A recombinant thermophilic NAD-dependent dehydrogenase having a hydrophobic amino acid at position 104 and/or 102. The enzymes are effective in catalysing the dehydrogenation of homologues of pyruvic acid of formula CnH.sub.2n+1 COCOOH, wherein n is>1, to homologues of lactic acid of formula CH.sub.n H.sub.2n+1 CHOHCOOH, wherein n is>1.

Abstract: A method for dehalogenation of organohalogen compounds, e.g. environmental pollutants in industrial waste. The organohalogen is reacted with a reducing agent in the presence of a selected metal-centered corrin, porphyrin or phthalocyanine complex. Preferred complexes are hydrolysis products of cyanocobalamin, of formula (I), in which R.sup.1 is NH.sub.2 or OH, R.sup.2 is H, CH.sub.2 CH.sub.2 COOH or CH.sub.2 CH.sub.2 CONH.sub.2, R.sup.3 is H, CH.sub.2 CH.sub.2 COOH or CH.sub.2 CH.sub.2 CONH.sub.2, and R.sup.4 is NHCH.sub.2 CH(OH)CH.sub.3, OH or NH.sub.2. The complex is preferably immobilized on a substrate. Some novel metal-centered porphyrin complexes are also described. A dehalogenation apparatus using the method of the invention is also described.

Abstract: The concentration of an ionic species (e.g. K.sup.+) is determined using an ion sensitive electrode having an appropriate membrane (e.g. valinomycin in plasticised PVC). In place of a conventional reference electrode, the half cell is completed with an electrode having an identical membrane but lacking the constituent producing the ion-selective response (e.g. plasticised PVC). The working and reference electrodes can then be made in substantially the same manner to null of interferents. The difficulties associated with double junctions are avoided.

Abstract: A process is provided for the purification of L-asparaginase by contacting a crude extract of L-asparaginase with a solid medium having cation exchange groups so as to adsorb L-asparaginase on the support and eluting adsorbed L-asparaginase from the support. The cation exchange groups comprise sulphonate groups and the elution step is carried out at a pH which is higher than the pH used in the contacting step.

Abstract: A method of monitoring the aggregation of cells in, for example, an immuno-agglutination assay, comprises promoting agglutination sonically in a capillary and inverting the capillary to cause agglutinated particles to settle at a meniscus. The granular appearance of agglutinated cells can be distinguished visually from the smooth distribution of non-aggregated cells.

Abstract: Particle velocity is determined optically through the use of crossed interference fringe patterns. The fringe patterns are produced by passing laser beams of distinct wavelength along a common optical fibre and through two crossed diffraction gratings which are bonded to the free end of the fibre. Each diffraction grating is constructed in the manner of an interference filter so as to produce interference fringes at one wavelength but to transmit the other wavelength substantially uniformly across the grating. Other interference elements can be used in place of diffraction gratings and the use of a single diffraction grating is envisaged in certain circumstances. An indication of the sense of particle movement can be achieved by creating a fringe pattern of steadily increasing fringe spacing.

Abstract: Filtering apparatus for the separation of microparticles such as bacteria has two planar sheets each with an array of laser drilled or etched pores. One or both of the sheets can be displaced relative to the other under feedback control to bring the pores into greater or lesser register. The effective pore size is thus varied to provide controlled selectivity.

Abstract: An electrochemical reference element is proposed having a metal electrode such as silver coated with the tetraphenyl (TPB) salt of the metal. The element may form the internal reference of an ion selective electrode with an ion selective membrane carried directly upon the TPB coating. The element provides a thermodynamically reversible couple suitable for use in a non-aqueous environment.

Abstract: A method is provided for treating a viral infection in a subject by administering a surfactant and/or a steroid so as to produce a high concentration thereof in the systemic circulation. The method is particularly applicable to the treatment of HIV infections. The use of surfactants and/or steroids in the production of pharmaceutical compositions is described.

Abstract: Apparatus for optical analysis of particles such as biological cells utilizes twin beams passing through a common optical fibre to avoid problems of alignment. For scattering measurements, a narrower beam can be used to gate detection of a broader beam to avoid amiguities associated with off-axis particles. The twin beams can also be used for thermal lensing, fluorescence or other techniques. Different beam diameters can alternatively be achieved in a single beam by controlling the focal length of a beam focussing lens.

Abstract: A filter which is particularly useful with biological material is formed of porous piezoelectric material such as PZT or Polyvinylidene fluoride. By an application of a voltage to the piezoelectric material, the filter body is caused to vibrate so as to inhibit fouling. In a modification, the piezoelectric material is not itself porous but is bonded to a filter membrane such that vibrations of the piezoelectric material are transmitted to the membrane. Through suitable control of the vibration, the selectivity of the filter can be controlled. In other modifications the vibratory movement of the filter membrane can be produced in other ways such as electro-mechanically.

Abstract: A method of investigating the condition of biological particles, in particular the fraction of viable cells in a bacteria population involves applying a voltage and monitoring the voltage induced by magnetic induction in a detector coil. The applied voltage is of a variable frequency alternating voltage and is preferably induced in the medium through a drive coil.