Monte Carlo simulations and experimental results on neutron production in the uranium spallation target QUINTA irradiated with 660 MeV protons.

The activation experiment was performed using the accelerated beam of Phasotron accelerator at the Joint Institute for Nuclear Research (JINR). The natural uranium spallation target QUINTA was irradiated with protons with energy 660 MeV. Monte Carlo simulations of neutron production were performed using the Geant4 code. The number of leakage neutrons from the sections of the uranium target surrounded by the lead shielding and the number of leakage neutrons from lead were determined. The total number of fissions in the setup QUINTA was determined. Experimental values of reaction rates for the produced nuclei in the 127I sample were obtained and several values of reaction rates were compared with the results of simulations. Experimentally determined fluence of neutrons in energy interval 10-175 MeV using the (n,xn) reactions in the 127I(NaI) sample was compared with the results of simulations. Possibility of transmutation of the long-lived radionuclide 129I in the QUINTA setup was estimated.

Characterization of the alpha-amylase-encoding gene from Thermomonospora curvata.

The nucleotide sequence of a 3007-bp DNA fragment from Thermomonospora curvata CCM3352 containing the coding and regulatory region of the alpha-amylase-encoding gene (tam) was determined. Primer extension mapping was used to determine the 5' end of the transcript, and it was demonstrated that the gene is transcribed from a unique promoter which is also functional in Streptomyces lividans TK24. Transcription of tam in T. curvata was induced by maltose, even in the presence of glucose. In S. lividans, tam was expressed constitutively. The deduced amino acid sequence reveals a considerable similarity with alpha-amylases from streptomycetes.

[Computed tomography and magnetic resonance tomography of the lower leg in chronic venous insufficiency]. / Computertomographie und Kernspintomographie des Unterschenkels bei chronischer Veneninsuffizienz.

Sixty-two lower limbs in 29 women and six men with chronic venous insufficiency (CVI) of grade II and III were examined by CT and eight of these additionally with MRI. The changes were compared with the findings in 21 patients of similar age, but without venous abnormalities. The most important findings were subcutaneous fibrosis with or without calcification, nonspecific infiltration of the extrafascial spaces and degeneration of the Achilles' tendon. The simultaneous occurrence of these changes can be regarded as typical of advanced CVI. CT was somewhat superior to MRI; its use can be justified as part of posttherapeutic follow-up and for special problems.

Transformation of Streptomyces lincolnensis protoplasts with plasmid vectors.

A method for the preparation and regeneration of protoplasts of Streptomyces lincolnensis is described. Mycelium in the early exponential phase appeared to be most suitable for this purpose and yielded up to 25% regenerated intact cells. Transformation of S. lincolnensis protoplasts was achieved using broad-host-range streptomycete plasmid vectors pIJ622, pMP66, pRS410 and pIJ943 constructed from replicons pIJ101, pSLG33 and SCP2. The efficiency of transformation was 3.10(3) transformants per micrograms plasmid DNA when (2-5).10(7) recipient protoplasts were used. Interspecific transformations showed that there is no efficient restriction system in S. lincolnensis that would limit the transfer of genetic information from S. lividans or E. coli.

Selective regeneration of Bacillus subtilis protoplasts transformed to kanamycin resistance.

An HTY medium osmotically stabilized with 0.5 M D-glucitol was used for regeneration of Bacillus subtilis protoplasts. The application of glucitol as osmotic stabilizer allows simultaneous selection of cells resistant to kanamycin to be made since this antibiotic is not inactivated by glucitol when added to the regeneration medium.

Preparation of protoplasts and regeneration of intact cells of Streptomyces cinnamonensis.

Protoplasts were prepared and intact cells were regenerated in Streptomyces cinnamonensis--a monensin producer--to make genetic manipulations with this strain possible. 70-80% of protoplasts were formed and up to 90% of them could regenerate into intact cells.

Transformation in Bacillus subtilis. Initial stages of the transformation process and their energy dependence.

NaN3 was found to inhibit transformation but not the irreversible binding of donor 3H-DNA in competent cells of the original low-transformable strain Bacillus subtilis 168 trp2. Addition of NaN3 to cells of two mutants Bacillus subtilis HT39 and HT46 with an increased transformability decreased substantially the irreversible binding of the donor DNA to the competent cells. The decreased irreversible binding of DNA is caused by an increased osmotic sensitivity of competent cells of the mutants HT39 and HT46 in the presence of NaN3, leading preferentially to lysis of the competent cells.

Degradation by Eco R1 endonuclease of DNA isolated from phages infecting Bacillus licheniformis and Bacillus thuringiensis.

DNA was isolated from lytic phages of two strains, Bacillus licheniformis, a producer of bacitracin, and Bacillus thuringiensis forming protein paracrystals with pronounced insecticidal effects. Its sensitivity to Eco R1 restriction endonuclease was determined. It was the aim of the work to find out whether these phages could serve as vectors in the transfer and possible amplification of genes of the two important industrial species of bacilli. Approximate values of the molecular weight of DNA of the two phages were determined after degradation of the phage DNA by Eco R1, followed by comparison of electrophoretic mobility of individual fragments with that of the Eco R1-degraded DNA of phage lambdab2.

Transformation of Streptomyces granaticolor with natural and recombinant plasmid vectors.

Protoplasts of Streptomyces granaticolor were found to be transformable by the broad-host-range plasmid pIJ350 but no transformants were detected when the narrow-host-range plasmid pIJ2 or the shuttle vector pPM66 (pIJ350--pBR322) isolated from E. coli cells were used. The onset of blue colour granaticin production by S. granaticolor cells was used as a marker to prepare protoplasts with a high transformation capacity. The presence of a restriction system is discussed.

WD-repeat protein encoding genes among prokaryotes of the Streptomyces genus.

Southern hybridization with probes designed for detection of WD-repeats coding sequences gave positive results in 21 streptomycete strains indicating that WD-repeats encoding genes are massively spread among streptomycetes. One of them, the wdlA gene of Streptomyces lincolnensis, codes for a 971 amino acid protein with seven WD-repeats in its C-terminus, two transmembrane domains and an ATP/GTP binding site upstream of the WD-repeat region.

Large-scale isolation and partial characterization of plasmid DNA from B. larvae.

Large-scale preparation of plasmid DNA from two Bacillus larvae strains 423 and 728, honey-bee pathogens, is described. The isolated plasmid DNAs were analyzed by restriction enzyme mapping. No difference in the resulting maps was found for six restriction enzymes. The plasmid DNAs were also compared by Southern blot hybridization and by electron microscopy. The results confirmed the identity of these plasmid DNAs. All these data suggest that B. larvae strains harbor the same plasmid.

Constitution of the metabolic type of streptomycetes during the first hours of cultivation.

Using the examples of biosynthesis of streptomycin, bialaphos, actinorhodin, oligoketides and autoregulators during the first hours of streptomycete cultivation, it is stressed that the external environment in cooperation with the internal metabolic abilities of the cell determines the metabolic type that would develop during the life cycle of the producing streptomycetes. If we accept that a certain metabolic type (from the point of view of the production of secondary metabolites) was determined already during the first hours of cultivation of the microorganisms, we must also admit that the availability of primary metabolites in the so-called production phase of growth (stationary phase, idiophase, etc.) is to a certain extent determined by the very early stages of strain development.

D-Glucosamine as inhibitor of early processes of transformation in Bacillus subtilis 168 trp2.

Glucosamine added to a transformation medium (TM2) after a 30-min cultivation of cells exhibited the highest inhibitory effect on the transformation process in Bacillus subtilis 168 trp2. The recipient culture was least sensitive to glucosamine added after 50 min. Glucosamine had no inhibitory effect when added 10 min after the transformation DNA.

Isolation and characterization of the pMI10 plasmid from Bacillus subtilis, an alpha-amylase producer.

The plasmid DNA pMI10 (5310 bp) was isolated from the alpha-amylase producing strain B. subtilis A18. Thirteen restriction endonucleases were used to digest pMI10 DNA and the restriction map of pMI10 DNA was constructed by mapping PstI (1), HindII (2), BglI (2), BspRI (3) and HindIII (3) sites.

Effect of temperature on alpha-amylase formation and DNA replication in Bacillus subtilis.

The effect of temperature on extracellular alpha-amylase synthesis and chromosomal and plasmid DNA replication in Bacillus subtilis A18 carrying plasmid pMI10 was studied. The specific growth rate mu increased with elevated temperature up to 42.5 degrees C, while the activities of alpha-amylase per population dry mass decreased. No obvious quantitative changes of 14C-thymidine incorporation per dry mass increase and no basic differences in plasmid copy number in the range of temperatures from 25 to 40 degrees C were found.

Non-transformable mutants of Bacillus subtilis defective in the penetration of DNA into the cell.

Four non-transformable mutants of Bacillus subtilis 168 defective in the penetration of DNA into the recipient cell were isolated. All mutants were fully non-transformable with mutation in genes influencing irreversible binding of the donor DNA by the recipient cell.

Effects of temperature and novobiocin on the expression of calf prochymosin gene and on plasmid copy number in recombinant Escherichia coli.

Escherichia coli strain HB101 harboring an expression plasmid bearing calf prochymosin gene under the control of the tac promoter was grown in the presence of IPTG with or without novobiocin at 28 and 40 degrees C, respectively. The differential rates of synthesis of prochymosin inclusions, and, for comparison, of beta-lactamase and beta-galactosidase, as well as plasmid copy number, were determined during the first hours of steady state growth. At 28 degrees C the induced expression of prochymosin gene was almost blocked. Addition of novobiocin did not alleviate this effect. In fact, it strengthened it, and we conclude that both these additive inhibitory effects are a consequence of the decrease in negative superhelical tension of plasmid DNA to an insufficient level. At 40 degrees C the differential rate of prochymosin synthesis was markedly enhanced. Since the copy number of the expression plasmid increased approximately to the same extent, we conclude that an increase in gene dose is the cause. The stimulation of cloned heterologous gene expression at 40 degrees C and inhibition at 28 degrees C may be conveniently used in biotechnological-scale cultivations of some recombinant bacteria.

Transfer of liposome-encapsulated plasmid DNA to Bacillus subtilis protoplasts and calcium-treated Escherichia coli cells.

Protoplasts of Bacillus subtilis 168 trpC2 str and cells of Escherichia coli SK 1590 after treatment with calcium chloride were transformed to tetracycline resistance with the recombinant plasmid pUN82 entrapped in the reverse phase evaporation liposomes. Frequency of transfer was 4 X 10(-4)% in B. subtilis and 8 X 10(-6)% in E. coli.

[Phalloplethysmographic findings in homosexual pedophile offenders]. / Falopletysmografické nálezy u pachatelu homosexuálne pedofilních deliktu.

Using phalloplethysmographic tests comprising 20 coloured slides of four categories the authors examined 50 homosexual pedophil delinquents and a matched group of heterosexual men. The findings of the two compared groups differed significantly on exposure to three categories of erotic stimuli--adult heterosexual and homosexual objects and child homosexual objects. Only on projection of child heterosexual objects there were no statistically significant differences in the number and magnitude of positive vasomotor reactions recorded in the two groups. Men in the control group responded more frequently and more positively to adult heterosexual objects than homosexual pedophil delinquents. The latter responded more frequently positively to adult and child homosexual objects. In more than one quarter of the delinquents (13 men) a preference of child objects was found, i.e. a deviant pedophil orientation. In seven men the preference of child objects was without sexual differentiation, six men preferred homosexual child objects.

[Phalloplethysmography findings in pedophilia and exhibitionism offenders]. / Falopletysmografické nálezy u pachatelu pedofilne exhibicionistických deliktu.

BACKGROUND: Exhibitionist behaviour focused on children (usually girls) is one of the most frequent forms of sexual child abuse. Exposure in the presence of children signalizes possible pedophil inclinations of the offender. The present paper presents the results of PPG examinations of these offenders with special attention to assessment how often these men have an objective phallographic pedophil orientation. The results of PPG examinations in this group of sexual delinquents are also compared with the findings in a control group of men who report a heterosexual orientation and preference of objects of suitable age. METHODS AND RESULTS: Using an electrocapacitance phalloplythysmographic apparatus the authors examined 50 men (mean age 36.3 years, range 17-67 years) who committed exhibitionist activities in the presence of girls under 12 years. The PPG examination was made under standard conditions; all examined subjects were shown sets of coloured slides with adult and child objects of hetero and homosexual character. In the same way a control group was examined formed by 50 male volunteers of similar age and social background. The men in the control group responded more frequently and more merkedly by positive vasomotor reactions to adult heterosexual objects than subjects who committed pedophil exhibitionist offences. The latter reacted significantly more often to child objects of both sexes. In more than half the delinquent group (in 26 men) there was an undefined differentiation of age as regards objects of female sex and 6 (12%) men of this group had preference for heterosexual child objects, i.e. an obvious pedophil orientation. In men of the control group only in one case there was an indication of an ill defined differentiation of age, in all the others an unequivocal or clearly indicated preference of heterosexual objects was found. CONCLUSIONS: PPG examinations confirmed that only a minor part of subjects committing pedophil exhibitionist offences have a deviant orientation. It was revealed that the most frequent phallographic finding in this group of sexual delinquents is an ill defined differentiation of age in objects of female sex. The investigation confirmed the importance of phalloplethysmography in elucidating sexually motivated structures of offenders of pedophil sexual activities.