[Comparative evaluation of treatment results in advanced multiple myeloma with the help of polychemotherapy with vincristine, doxorubicin, dexamethasone (VAD) or only with dexamethasone].

A prospective clinical trial was undertaken to determine the therapeutical effectiveness of multidrug chemotherapy consisting of vincristine, doxorubicin and dexamethasone (VAD) or only high dose of dexamethasone (D) in 56 patients with multiple myeloma (MM). The group of patients included 41 with intermediate (II) and 15 with high (III) tumor mass. The final evaluation was performed in 19 patients treated with D and in 19 receiving VAD regimen.

Transformation of Thiobacillus versutus with plasmid DNA.

The representative of the facultatively chemolithotrophic thiobacilli, Thiobacillus versutus has been successfully transformed for the first time with plasmid DNA. The plasmid used for the transformation study was pKK2, a derivative of the broad host range pSa plasmid conferring Km resistance being effectively expressed in T. versutus.

Wavelength referencing in single-mode microbend sensors.

The strong wavelength dependence of microbending losses in single-mode fibers is utilized in wavelength referencing for fluctuation-free microbend sensors. Through fiber size and microbend periodicity, optimization of the wavelength dependence can be increased dramatically. The reference and signal wavelengths can be provided through the spectrum of a light-emitting diode.

Penicillin-binding proteins of Thiobacillus versutus.

The cytoplasmic membrane of Thiobacillus versutus was found to contain at least nine penicillin-binding proteins (PBPs) with apparent molecular weights as judged by sodium dodecyl sulphate polyacrylamide slab gel electrophoresis of 87000 (PBP1), 81000 (PBP2), 68000 (PBP3), 63000 (PBP4), 57000 (PBP5), 40000 (PBP6), 37000 (PBP70, 33000 (PBP8) and 31000 (PBP9). The PBP pattern of T. versutus was thus quite different from that of the Enterobacteria and the Pseudomonads.

R68.45 plasmid mediated conjugation in Thiobacillus A2.

Plasmid R68.45 classified into the IncP-1 group which is characterized by a broad host range, was transferred from Pseudomonas aeruginosa PA025 or Escherichia coli into Thiobacillus A2 by conjugation. The R plasmid was stably maintained in Thiobacillus A2 but only neomycin/kanamycin resistance was fully expressed in the new host.

Replication of plasmid R6K in DNA polymerase deficient mutants of Escherichia coli.

The plasmid R6K has been introduced into a number of Escherichia coli polymerase deficient (pol) mutants. In polCts mutants transferred to the nonpermissive temperature to inactivate polymerase III, R6K replicates but the replication products have a density in dye-CsCl gradients intermediate between supercoiled and linear forms. This aberrant replication requires normal cellular levels of polymerase I since it does not occur in polA polCts mutants.

Isolation and preliminary characterization of R6K plasmid deletion mutants.

Several deletion mutants of R6K have been isolated by mutagen treatment of bacterial host carrying wild type of the plasmid and search for clones that lost ampicillin or streptomycin resistance. The molecular weight of the mutants as estimated by agarose gel electrophoresis was 15 times 10(6) minus 23 times 10(6) compared to 26 times 10(6) for the parental plasmid. The mutants were characterized in respect of the level of resistance to ampicillin and frequency of conjugational transfer.

Nonintegrated plasmid-chromosome complexes in Escherichia coli.

A number of plasmid systems have been examined for the ability of their covalently closed circular deoxyribonucleic acid (CCC DNA) forms to cosediment in neutral sucrose gradients with the folded chromosomes of their respective hosts. Given that cosedimentation of CCC plasmid and chromosomal DNA represents a bound or complexed state between these replicons, our results can be expressed as follows. (i) All plasmid systems complex, on the average, at least one plasmid per chromosomal equivalent.