Authors:L. Nagy, T. Gajda, J. Kürti, K. Schrantz and K. Burger
Iron(III) complexes of D-saccharose and D-glucose were prepared. The compositions of the complexes were determined by standard analytical methods. The Mössbauer spectra reflected the presence of high-spin iron(III) in the polynuclear species. EPR spectroscopy demonstrated antiferromagnetically coupled iron(III) centers within the solid complexes. The13C NMR spectra indicated the presence of a mixture of coordination isomers of iron(III) complexes containing the sugar ligand in differently bound forms.
Authors:I. Gresits, S. Tölgyesi, L. Nagy and J. Solymosi
A radioisotope-excited energy-dispersive X-ray fluorescence system has been constructed and used for the analysis of blood samples for trace elements. The possibility of determination of trace elements in blood by X-ray fluorescence based on comparison with standard reference materials has been outlined and the applicability of the method demonstrated by the analysis of blood samples. The method enables fast, non-destructive direct analyses to be carried out without lengthy sample pretreatment on a routine basis.
Several sorbents were prepared by precipitating zirconium phosphate on activated carbon support material. The main parameters
of the chemical procedure were optimized in order to obtain the highest decontamination factors which can be achieved in the
case of Cs+, Sr2+ and I− ions. For the characterization of the sorbents, sorption isotherms and capacity data were determined. The reproducibility
of the preparation is about 10%.
Authors:K. Szabó, L. Nagy, G. Török, D. Hegedüs and G. Fóti
A control system for monitoring the radioactive concentration in aqueous wastes of nuclear installations was elaborated. The
mobile station developed for in situ control enables simultaneous measurement of gamma radiation in the energy range of 0.15–2.0
MeV and that of beta radiation in the energy range of 0.3–2.0 MeV by means of a combined scintillation detector. Disturbing
effects of accompanying and secundary radiations on the determination of the counting efficiency vs. radiation energy functions
used in calculation of the radioactive concentration limits as well as some experiences during a long time of operation of
the system have been discussed.
Authors:L. Kredics, Zsuzsanna Antal, Ilona Dóczi, L. Manczinger, F. Kevei and Elisabeth Nagy
Cefditoren is the active form of cefditoren pivoxil, a new, broad-spectrum oral cephalosporin with strong in vitro activity against penicillin-susceptible and resistant Streptococcus pneumoniae. In this study, the minimum inhibitory concentrations (MICs) of cefditoren were determined for a special selection of S. pneumoniae isolates known to be susceptible, moderately susceptible or fully resistant to penicillin; these isolates originated from the lower respiratory tract of adults with pneumonia or the upper respiratory tract of children with or without symptoms of infection. Some of this latter group of isolates exhibited extremely high MICs to penicillin (³32 mg/l), whereas the MICs of cefditoren did not exceed 2 mg/l. The MIC50 and MIC90 of cefditoren proved to be 0.25 and 1.0 mg/l, respectively, with a range of MICs £0.015-2.0 mg/l for all the tested S. pneumoniae isolates. Its good activity suggests that cefditoren is expected to be a potent drug in infections caused by penicillin-resistant and multidrug-resistant S. pneumoniae.
Authors:L. Kredics, Zsuzsanna Antal, A. Szekeres, L. Manczinger, Ilona Dóczi, F. Kevei and Elisabeth Nagy
Species belonging to the filamentous fungal genus Trichoderma are well known as potential candidates for the biological control of plant pathogenic fungi and as cellulase producers of biotechnological importance. Several data were published in the last decade also about the clinical importance of this genus, indicating that Trichoderma strains may be potential opportunistic pathogens in immunocompromised patients. However, there is a lack of information about the potential virulence factors of clinical Trichoderma strains. This study was designed to examine the extracellular proteolytic enzymes of six clinical T. longibrachiatum isolates. Supernatants from induced liquid cultures of the examined strains were screened for proteolytic enzyme activities with 11 different chromogenic p-nitroaniline substrates. The production of trypsin-like, chymotrypsin-like and chymoelastase-like protease activities cleaving N-Benzoyl-L-Phe-L-Val-L-Arg-p-nitroanilide, N-Succinyl-L-Ala-L-Ala-L-Pro-L-Phe-p-nitroanilide,and N-Succinyl-L- Ala-L-Ala-L-Pro-L-Leu-p-nitroanilide, respectively, was common among the strains examined. Separation of trypsin- and chymotrypsin-like activities by column chromatography revealed, that both systems are complex consisting of several isoenzymes. The pH-dependence of these two protease systems was also studied. Based on the results, the different isoenzymes seem to have different optimal pH values. Extracellular proteolytic enzymes may be involved in the pathogenecity of Trichoderma strains as facultative human pathogens.