Immunohistochemical localization of 36 and 29 kDa proteins in sparganum.

Antigenic proteins of 36 and 29 kDa were localized in Spirometra mansoni plerocercoid (sparganum) immunohistochemically by avidin biotin complex (ABC) staining. When polyclonal antibodies such as BALB/c mouse serum immunized with crude saline extract of sparganum or confirmed sparganosis sera were reacted as primary antibodies, the positive chromogen (3-amino, 9-ethylcarbazole) reactions were recognized at syncytial tegument, tegumental cells, muscle and parenchymal cells and lining cells of excretory canals. A monoclonal antibody (MAb) which was reacting to 36 and 29 kDa proteins in the extract of the worm was localized at the syncytial tegument and tegumental cells. The present results suggested that the potent antigenic proteins of 36 and 29 kDa in sparganum were produced at the tegumental cells and transported to the syncytial tegument.     

Kinetic properties of a L-cysteine desulfhydrase-deficient mutant in the enzymatic formation of L-cysteine from D,L-ATC

Summary A mutant strain lacking in activity of L-cysteine desulfhydrase, a L-cysteine-decomposing enzyme, was screened after UV-treatment ofPseudomonas sp. CU6. The properties of the two strains, original and mutant, were compared on the basis of parameter values estimated from kinetic simulations of the enzymatic formation of L-cysteine from D,L-ATC. Both strains suffered from product inhibition, though inhibition was less for the mutant strain.     

Purification of monomeric agmatine iminohydrolase from soybean

Agmatine iminohydrolase (EC 3.5.3.12) was purified to homogeneity from the cytosol of soybean (Glycine max) axes by chromatographic separations on Sephadex G-25, Bio-rex 70, and agmatine-affinity columns. The enzyme was homogeneous by the criteria of analytical gel electrophoresis. Molecular weights estimated by Sephadex G-100 gel and sodium dodecyl sulfate polyacrylamide gel electrophoresis were 70,000, indicating that the soybean axes enzyme is a monomer, in contrast to the dimeric enzymes from corn and rice. The isoelectric point determined by gel electrofocusing was 7.5, higher than that of the corn enzyme (4.7). The optimal pH and temperature for activity were 6.5 and 50 degrees C, respectively. The enzyme has high specificity for agmatine, and the Km for agmatine was 2.5 x 10(-3) molar. The enzyme was sensitive to Cu2+ and also was inhibited by p-hydroxymercuribenzoate.     

Image processing software for enhanced visualization of faint or noisy autoradiographic images

A computer program for digital image processing is described which can be implemented using scanning densitometer hardware pre-existing in most biology departments plus computer video hardware which may either pre-exist in the biology department or would represent a moderate upgrade over an already planned computer purchase. The primary purpose of this computer program is to provide contrast enhancement of faint or low contrast autoradiograph images and to implement background subtraction and digital smoothing methods which permit visualization of blurry electrophoresis bands against noisy backgrounds. However, the program also has modest editing capabilities that allow its use in the routine preparation of images for publication. Finally, the program has facilities for deblurring, edge enhancement and multiple image averaging, which give it usefulness in other forms of photographic analysis.     

A linkage map of distal mouse chromosome 12

To refine the linkage map of distal mouse Chromosome 12, we have identified DNA restriction fragment variants associated with a creatine kinase gene (Ck-3), the Akt proto-oncogene, an Abelson proviral integration site (D12N1), and the immunoglobulin heavy chain V_H3609 variable region family (Igh-V36). The patterns of inheritance of these markers in backcross progeny and recombinant inbred mouse strains allowed their localization with respect to previously mapped genes to yield the linkage map: Aat-15.8 cM-Ck-3-0.9 cM-(Crip, Akt, Igh-C)-0.3 cM-(D12N1, Igh-V). This map confirms genetically the localization of the Igh-V gene complex distal to Igh-C on the chromosome. It differs from previous maps in placing D12N1 distal to Igh-C, and in suggesting that the Igh-V gene complex spans less than one centiMorgan (cM).Other DNA sequence variants detected with the creatine kinase probe allowed definition of four additional genetic loci: Ck-1 near Lmyc-1 on Chromosome 4; Ck-2 between Upg-1 and Hprt-ps1 (D17Rp10) on distal Chromosome 17; Ck-4 near Mpmv-17 and Mls-3 on Chromosome 16; and Ck-5 near Hba on Chromosome 11.     

Immobilization of enzymes on activated carbon: selection and preparation of the carbon support.

Based upon its superior catalytic activity for H2O2 decomposition, a bituminous coal-based activated carbon was selected for investigations of pretreatment and enzyme immobilization methods. Pretreatments considered include acid washing, exposure to strong oxidizing agents, contact with concentrated peroxide solutions, nitration and amination, isothiocyanate derivatization, silanization, and stearic acid coating. Effects of these pretreatments on morphology and trace-metal content of the carbon pellets have been studied using scanning electron microscopy and dispersive analysis of x rays. Immobilization of glucoamylase by adsorption, glutaraldehyde crosslinking, and covalent attachment to carbon activated by water-soluble diimide or diazotization have been examined. These different enzyme-carbon catalysts have been characterized by their enzyme loading, enzyme activity, catalytic activity for H2O2 decomposition, or combinations of these measures of performance.     

Enterobacteriaceae and Pseudomonas aeruginosa Recovered from Vegetable Salads

Klebsiella, Enterobacter, and Serratia were recovered frequently in high counts from vegetable salads. Pseudomonas aeruginosa, although isolated frequently, was in lower counts.