Search

The aim of this study was to analyse epidemiological and clinical characteristics of invasive pneumococcal disease (IPD) in adults before and after the introduction of the general childhood conjugate pneumococcal vaccination programme in the Czech Republic.The retrospective observational sentinel study included adults with IPD admitted to the Na Bulovce Hospital in Prague from 1/2000 through 12/2019. A case of IPD was defined as isolation of Streptococcus pneumoniae from a primarily sterile site.A total of 304 IPD cases were diagnosed during the study period, with a male to female ratio of 1.49:1 and age median of 58 years (IQR 43-73). The most prevalent clinical forms were bacteraemic pneumonia (185 cases; 60.9%) and purulent meningitis (90; 29.6%). A total of 157/293 patients (53.6%) required intensive care, and the case fatality rate was 25.3% (n = 77). The serotype was determined in 292 (96.0%) isolates, the most prevalent being serotypes 3 (38; 12.5%), 4 (28; 9.2%), 7F (24; 7.9%), 8 (21; 6.9%), and 1 (18; 5.9%). Both clinical and epidemiological characteristics of IPD caused by the most prevalent serotypes differed considerably. Patients diagnosed with serotype 3 were older, more frequently required intensive care, and showed higher mortality. The proportion of IPD caused by non-PCV13 serotypes increased from 28.8% (19/66) in 2000-2005 to 54.8% (40/70) in 2015-2019 (p = 0.001).The study demonstrated that invasive diseases caused by the most prevalent pneumococcal serotypes differ in their epidemiological and clinical characteristics and case fatality rate. During the study period, there was a significant increase in IPD caused by non-PCV 13 serotypes, limiting the effect of vaccination in adults.

One of the tasks of top management is during the meeting the goal of sustainable development and market growth to ensure that the resources that are essential to the implementation and fulfillment of the objectives are identified and made available. These resources include employees, suppliers, information, infrastructure, work environment or financial resources. But what gives the business a competitive advantage? With application of existing resources management methods, it is to realize its strategic capabilities and to find ways how to link the organization’s resources and performance to each other. This means identifying how organizations contribute to value creation and find key value drivers. The aim of the article is to identify the value drivers and, on the basis of the choice of one value driver, to show when it changes it effects the operating profit of the construction company. For the purpose of creating this target, the values from the company’s accounting statements will be used, the percentage method will be used to determine the costs during the reporting period. By using the sensitivity analysis method, it will be examined the impact of the change in the value driver on the operating profit.

Although spring viremia of carp virus (SVCV) can cause high mortalities in common carp, a commercial vaccine is not available for worldwide use. Here, we report a DNA vaccine based on the expression of the SVCV glycoprotein (G) which, when injected in the muscle even at a single low dose of 0.1 µg DNA/g of fish, confers up to 100% protection against a subsequent bath challenge with SVCV. Importantly, to best validate vaccine efficacy, we also optimized a reliable bath challenge model closely mimicking a natural infection, based on a prolonged exposure of carp to SVCV at 15°C. Using this optimized bath challenge, we showed a strong age-dependent susceptibility of carp to SVCV, with high susceptibility at young age (3 months) and a full resistance at 9 months. We visualized local expression of the G protein and associated early inflammatory response by immunohistochemistry and described changes in the gene expression of pro-inflammatory cytokines, chemokines, and antiviral genes in the muscle of vaccinated fish. Adaptive immune responses were investigated by analyzing neutralizing titers against SVCV in the serum of vaccinated fish and thein vitroproliferation capacity of peripheral SVCV-specific T cells. We show significantly higher serum neutralizing titers and the presence of SVCV-specific T cells in the blood of vaccinated fish, which proliferated upon stimulation with SVCV. Altogether, this is the first study reporting on a protective DNA vaccine against SVCV in carp and the first to provide a detailed characterization of local innate as well as systemic adaptive immune responses elicited upon DNA vaccination that suggest a role not only of B cells but also of T cells in the protection conferred by the SVCV-G DNA vaccine.

PurposeThe purpose of this paper is to synthesize anticorrosion pigments ZnFe2O4 from diverse raw materials of various shapes and size of primary particles.Design/methodology/approachAnticorrosion pigments were synthesized through a high‐temperature process during a solid phase. Zinc ferrites were prepared from hematite (α‐Fe2O3), goethite (α‐FeO.OH), magnetite (Fe3O4), and specularite (Fe2O3) entering into reaction with zinc oxide at temperatures ranging from 600 up to 1,100°C. The nature of the initial raw material, primarily the shape of its particles, affects the shape of the particles of the synthesized zinc ferrite. The formulated zinc ferrites had a rod‐shape, lamellar, and/or isometric shape. The shape of the particles of synthesized zinc ferrites was studied with regard to its effects on the mechanical and corrosion resistance of organic coatings. The obtained pigments were characterized by means of X‐ray diffraction analysis and scanning electron microscopy. The synthesized anticorrosion pigments were used to prepare epoxy coatings and water‐borne styrene‐acrylate coatings that were subjected to post‐application tests for physical‐mechanical properties and anticorrosion properties.FindingsThe shape of the particles was identified in the synthesized pigments. X‐ray diffraction analysis revealed the degree of precipitation and lattice parameters. All of the synthesized pigments had good anticorrosion efficiency in an epoxy and in styrene‐acrylate coatings. Compared with a commercially used anticorrosion pigment, their protective power in coatings was demonstrably stronger.Practical implicationsThe synthesized pigments can be used conveniently in coatings protecting metal bases against corrosion.Originality/valueThe synthesis of zinc ferrites with different particle shapes for applications in anticorrosion coatings provides a new way of protecting metals against corrosion. Of benefit is the fact that the synthesized pigments do not contain any environmentally harmful substances.

PurposeTo synthesise anticorrosion pigments of a lamellar and core‐shell type based on Zn, Ca and Mg ferrites for metal protecting paints.Design/methodology/approachThe anticorrosion pigments were synthesised from oxides or carbonates at high temperature. The pigments synthesised had particles with a pronounced lamellar‐tubular shape consisting of MgFe2O4; Mg0.8Zn0.2Fe2O4; Mg0.6Zn0.4Fe2O4; Mg0.4Zn0.6Fe2O4; Mg0.2Zn0.8Fe2O4; ZnFe2O4; Ca0.2Zn0.8Fe2O4; and CaFe2O4. The other type of synthesised ferrite pigments were core‐shell anticorrosion pigments where a layer corresponding to the compositions including MgFe2O4/KAl3Si3O11; Mg0.8Zn0.2Fe2O4/KAl3Si3O11; Mg0.6Zn0.4Fe2O4/KAl3Si3O11; Mg0.4Zn0.6Fe2O4/KAl3Si3O11; Mg0.2Zn0.8Fe2O4/KAl3Si3O11; ZnFe2O4/KAl3Si3O11; Ca0.2Zn0.8Fe2O4/KAl3Si3O11; and CaFe2O4/KAl3Si3O11 was applied onto the core – white mica – by a chemical reaction. The pigments prepared were characterised by means of X‐ray diffraction analysis, particle size distribution measurement, and scanning electron microscopy. The anticorrosion pigments synthesised were used to formulate alkyd paints that were tested in corrosion atmospheres.FindingsLamellar particles were detected in the pigments prepared, whereas quality coverage of the core was identified in the core‐shell ferrites. Good anticorrosion efficiency was detected in all of the pigments synthesised.Practical implicationsThe pigments synthesised can be conveniently utilised in paints to protect metal bases from corrosion.Originality/valueThe method of using the ferrites synthesised as metal protecting anticorrosion paints is new. Of great benefit are the application and the method of synthesising the anticorrosion pigments that do not contain any heavy metals and are environmentally friendly.

L. MART~NKOVA, P. JOZLOVA AND D. VESELV. 1995. The biological activity of the pigment extracts from Monascus purpureus included their antibiotic action not only against bacteria but also against some species of yeasts and filamentous fungi, as well as embryotoxicity and teratogenicity. These activities depended on the presence of the orange component (monascorubrin and rubropunctatin). The formation of these compounds was influenced by the composition of the culture medium and by cultivation of the fungus : when amino acids, peptides or proteins were available during cultivation, as in the case of solid-state cultivation on rice, wheat or pearl barley or submerged cultivation with an organic nitrogen source, the bioactive compounds were converted into inactive complexes and, to a lesser extent, into purple pigments (monascorubramine and rubropunctamine) which retained some biological activity. The toxicity of the orange pigments may reside in the same reaction as their detoxication, i.e. in their binding

We present the case of a 66-year-old female after renal transplant with severe course of herpes zoster (HZ). Although HZ represents a common infectious complication of transplant patients, its variable manifestation and ability to disseminate warrants serious consideration. Prompt diagnosis and treatment are essential in preventing further spread and disastrous complications.

Recent data from deep uranium mines in Czechoslovakia indicated that mines are exposed to other mutagenic factors in addition to radon daughter products. Mycotoxins were identified as a possible source of mutagens in these mines. Mycotoxins were examined in 38 samples from mines and in throat swabs taken from 116 miners and 78 controls. The following mycotoxins were identified from mines samples: aflatoxins B1 and G1, citrinin, citreoviridin, mycophenolic acid, and sterigmatocystin. Some mold strains isolated from mines and throat swabs were investigated for mutagenic activity by the SOS chromotest and Salmonella assay with strains TA100 and TA98. Mutagenicity was observed, especially with metabolic activation in vitro. These data suggest that mycotoxins produced by molds in uranium mines are a new genotoxic factor for uranium miners.

Neoangiogenesis and inhibition of apoptosis are two factors considered as major leading causes of tumorigenesis. NO, synthesized by NOS, plays an important role in tumour growth, dissemination and vascularization. Caspase-3 is an executive enzyme of apoptosis. The presented research work has been focused on the comparative evaluation of localization of the angiogenic and proapoptotic cytokines expressed in tonsillar diseases. The immunohistochemical reaction of eNOS, iNOS and caspase-3 in tonsillar cancer (N = 17), chronic tonsillitis (N = 11) and clinically healthy tonsils (N = 8) was detected. High eNOS occurrence in endothelial cells of highly vascularized regions in tonsillar cancer, variable eNOS expression in the vessels of lamina propria in chronic tonsillitis and high expression in the cytoplasm of endothelial cells of small veins in healthy tonsillar tissue was ascertained. Increased iNOS expression was found in cancer tissue in comparison with the healthy tonsils. Nevertheless, the highest expression of iNOS was found in chronic tonsillitis. Higher expression of caspase-3 was discovered in germinal centres of lymphoid follicles of the chronic tonsillitis tissue. However, the positivity in the interfollicular zone and surface squamous epithelium was weak only. Merely isolated caspase-3-positive cells were found in tonsillar cancer. Very low expression of caspase-3 was detected in the lymphatic follicles of the healthy tonsils. Research results showed high expression of eNOS in the carcinomatous tissue. The eNOS expression in chronic tonsillitis confirms its role in regulating the lymphocyte circulation. Low expression of caspase-3 in malignant epithelial cells of tonsillar cancer shows decreased capability of apoptosis compared to chronic tonsillitis tissue, where apoptosis seems to be rather frequent and concentrated in the germinal centres of lymphatic follicles. The differences in localization of eNOS and caspase-3 expression between benign and malignant processes may be a promising tool for precise morphological distinction of chronic inflammation and tumours.

The nutritional value of wheat artificially infested with Penicillium cyclopium, Mucor sp. and Aspergillus flavus was studied in two balance experiments on rats. The samples of ground wheat were sterilized by radiation, inoculated with the suspension of mould spores and incubated for 10 or 30 days at 25°C. The wheat samples and strains of moulds were tested for the production of aflatoxins, cyclopiazonic acid, citrinine, patuline, ochratoxin A and penicillic acid. In addition, the toxicity of wheat extract was tested on chicken embryos. Analyses for mycotoxins and chick embryo toxicity tests were negative. Mould infestation of wheat decreased the fat content and increased fat acidity. The amino acid content was somewhat higher in the inoculated wheat than in a non-inoculated control. The balance experiments showed that the strong infestation of wheat with moulds had no significant effect on the nitrogen digestibility or biological value of protein in rats.

IGF-I, HGF, TGFbeta1, bFGF and VEGF are involved in the pathogenesis of thyroid gland tumors and their growth. We decided to find whether changes in the production of these cytokines by thyroid tumor cells are reflected by changes of their peripheral blood. Using ELISA kits, we measured the concentrations of growth factors in the peripheral blood serum in 28 patients with thyroid gland tumors (14 adenomas, 14 papillary carcinomas) and compared these concentrations with those in healthy people. We found significantly lower serum levels of IGF-I in patients with thyroid adenoma compared to the healthy population. Serum levels of HGF and bFGF were significantly higher in patients with thyroid adenoma and papillary carcinoma compared with those in healthy subjects. Serum concentrations of TGFbeta1 and VEGF were not significantly different in any groups of investigated subjects. Changes in the production of these cytokines by thyroid gland tumor cells are reflected in their peripheral blood levels, but these levels also depend on a number of other physiological and pathological processes in the organism. However, significant differences of HGF and bFGF serum levels can be explained by their very high production by thyroid tumor cells and by their strong effect on the follicular and endothelial cell proliferation.

Rubropunctatin (1), monascorubrin (2), monascin (3) and ankaflavin (4) were purified from the mycelium of Monascus purpureus by flash chromatography on silica gel or reversed phase. Their embryotoxicity towards chicken embryos decreased in the order 2 > 1 > 3 > 4. The lower homologues 1 and 3 exhibited teratogenic effects on these organisms. Significant antibiotic activities against Bacillus subtilis and Candida pseudotropicalis were found with compounds 1 and 2. Immunosuppressive activity on mouse T-splenocytes was most pronounced with compounds 3 and 4. None of the compounds showed significant cytotoxic activity towards rat hepatocytes in vitro. Incubation of resting cells of M. purpureus with glycine afforded the dark-red compounds 5 and 6 where the pyran moiety of 1 and 2 changed into the N-substituted dihydropyridine moiety by replacement of the O-atom by the amino group of glycine. Compounds 5 and 6 were less biologically active than the major pigments 1-4.

Mycotoxins zearalenone and vomitoxin (4-deoxynivalenol) are often joint contaminants of grains infested by micromycetes of the genus Fusarium. Toxic effects of both mycotoxins on experimental organisms and farm animals are well known, but we have not found any literary reference to toxic effects of the combination zearalenone and vomitoxin. Embryotoxic effects of zearalenone, vomitoxin and combinations of various doses of zearalenone with constant addition of vomitoxin were studied in a three-day chick embryo. The objective of the study was to determine the coaction of vomitoxin on zearalenone embryotoxicity. Thermostat-incubated fertile eggs of White Leghorn hens were candled after three-day incubation, the shell above the embryo was removed, and within the embryotoxicity range zearalenone, vomitoxin and various doses of zearalenone with constant addition of 2 micrograms vomitoxin were applied to morphologically normal embryos. The groups of ten embryos were applied mycotoxins and their combinations in 10 microliters of their solutions to amnions using a special glass micropipette. Control group comprised twenty embryos which were applied 10 microliters of solvents used, 1% NaHCO3 and 10% ethanol. The eggs were covered with glass plates and their incubation was going on until the eighth day of their development. The embryos that died during incubation were discarded. On the eighth day of development, surviving embryos were taken out from the eggs and malformations of head, orofacial region, body wall, limbs and heart were determined microscopically. Tab. I shows total numbers of dead and malformed embryos after application of the particular doses of zearalenone, vomitoxin, their combinations and control solvents. The embryotoxicity range started at a dose of 5 to 20 micrograms per embryo. Zearalanone did not have any teratogenic effects on chick embryos. Applications of high doses of zearalenone (100 and 30 micrograms) instantly caused arrhythmia, atrio-ventricular dissociation or even heart stoppage. The beginning of the embryotoxicity range for vomitoxin was found to be within the narrow range of 1 to 3 micrograms per embryo. Among malformations, only a defect of the interventricular septum of the heart was found in 4% of the cases. The combined embryotoxic effects of zearalenone and vomitoxin were of additive, and mostly embryolethal nature. Among the malformations searched for, only 5% of the embryos exhibited a defect of the interventricular septum of the heart. Due to the good prediction fitness of chick embryo that has been proved by estimates of mycotoxin toxicity to mammals it is possible to suppose that toxic effects of the frequently occurring combinations of zearalenone and vomitoxin in fusarium-infected feeds will also be of additive nature for farm animals.

Three and four-day-old chick embryos were exposed to thalidomide as well as to its hydrolysis products before and after in vitro biotrasformation of these compounds with rat liver homogenate. Significant embryotoxic effects of 30 and 100 micrograms doses per embryo encountered only in the case when the products of alkaline hydrolysis of thalidomide were pretreated with rat liver homogenate.

Recent data from deep uranium mines in Czechoslovakia indicated that in addition to radon daughter products, miners are also exposed to chemical mutagens. Mycotoxins were identified as a possible source of mutagenicity present in the mines. Various methods of biomonitoring were used to examine three groups of miners from different uranium mines. Cytogenetic analysis of peripheral lymphocytes, unscheduled DNA synthesis (UDS) in lymphocytes, and lipid peroxidation (LPO) in both plasma and lymphocytes were studied on 66 exposed miners and 56 controls. Throat swabs were taken from 116 miners and 78 controls. Significantly increased numbers of aberrant cells were found in all groups of miners, as well as decreased UDS values in lymphocytes and increased LPO plasma levels in comparison to controls. Molds were detected in throat swabs from 27% of miners, and 58% of these molds were embryotoxic. Only 5% of the control samples contained molds and none of them was embryotoxic. The following mycotoxins were isolated from miners' throat swab samples: rugulosin, sterigmatocystin, mycophenolic acid, brevianamid A, citreoviridin, citrinin, penicilic acid, and secalonic acid. These data suggest that mycotoxins are a genotoxic factor affecting uranium miners.

A crucial role of the site of administration in the sensitivity of the alternative system using chick embryo for testing embryotoxicity was demonstrated by morphological evaluation of the effects of T-2 toxin and secalonic acid D, and by incorporation of [14C]sodium acetate radioactivity. Secalonic acid D, administered to 2-, 3-, and 4-day-old embryos in doses higher than 1 μg produced mostly malformations of the face (bilateral cleft beak, microphthalmia) while the teratogenic effects of T-2 toxin were being limited to the embryonic trunk of 2-day-old embryos (rumplessness) after administering doses higher than 0.001 μg. In case of subgerminal and intraamniotic injections, the doses of both mycotoxins needed for producing embryotoxic effects comparable to those obtained with the more commonly used yolk sac injections appeared to be lower by one and two orders of magnitude, respectively. The results stress the need of using the shortest transport channel of test substances from the site of application to the target tissues of the embryo, when the maximum sensitivity and reproducibility of the test system are to be expected. © 1992 Wiley-Liss, Inc.

Embryotoxic effects of 25 mycotoxins were investigated in two-, three- and four-day chick embryos; the results were evaluated on the eighth day of development. The embryotoxicity ranged from 0.0001 to 0.1 microgram per embryo in T-2 toxin, aflatoxin B1, G1, B2 and M1, cytochalasin E, ochratoxin A and PR-toxin; from 0.1 to 1.0 microgram per embryo in sterigmatocystin, aflatoxin G2, vomitoxin (4deoxynivalenol), patulin, rubratoxin B, secalonic acid D, mycophenolic acid, and from 1.0 to 100 micrograms per embryo in penicillic acid, cyclopiazonic acid, tenuazonic acid, citrinine, brevianamide A, zearalenone, fusaric acid, griseofulvin, kojic acid and 8-methoxypsolaren. Acute cardiotoxic effects were observed in PR-toxin, patulin, rubratoxin B, penicillic acid, citrinine and zearalenone. Teratogenic effects with a spectrum of different embryonal malformations occurred in T-2 toxin, ochratoxin A, PR-toxin, patulin, secalonic acid D, mycophenolic acid and citrinine. The embryotoxic effects demonstrated in chick embryos correlated with the well-know literary data on mammals. Considering the different chemical composition and biological effects of mycotoxins, we suppose that the embryotoxicity test of chick embryos will also be suitable for testing other biologically active substances in the environment.

Parasitic relationships between Pythium oligandrum Drechsler and some phytopathogenic species of the Oomycetes class were investigated on agar plates. A high parasitic ability of Pythium oligandrum on Pythium ultimum Trow, P. debaryanum Hesse, and Aphanomyces laevis De By species was proved in this study of relationships among these fungi, commonly populating the rhizosphere of emerging sugar beet. P. oligandrum produces numerous thin haustorial threads, searching the hyphae of host species and enwrapping them during the parasitation. In a later parasitation stage the host organs were enwrapped by thicker hyphae of P. oligandrum as well. P. oligandrum grew through the colony of parasitized species mostly within 24 hours after inoculation and was able to destroy it entirely within 5--6 days. P. oligandrum produced numerous fructification organs in contradistinction to parasitized species. P. oligandrum oospores germinated abundantly when host species were present. Hyperparasitism of P. oligandrum was found both in cultivation with a single host and in common cultivation with all three host species simultaneously.

Pythium oligandrum Drechsler was found as a very weak pathogen of emerging sugar-beet by means of the inoculation of the sterilized soil. The hyperparasitic ability of Pythium oligandrum Drechsler to relative species, viz. Pythium ultimum Trow and Pythium debaryanum (Hesse) were proved in rhizosphere of emerging sugar-beet. The rhizosphere soil inoculation by P. ultimum resulted in the sugar-beet emergence about 3% while the sugar-beet emergence achieved 110% if P. ultimum and P. oligandrum were inoculated simultaneously. The sugar-beet emergence due to the dual inoculation of rhizosphere soil by P. ultimum and P. debaryanum was about 3%, whereas due to P. ultimum, P. debaryanum, and P. oligandrum 77%.

The population of microorganisms in wheat rhizosphere changed in the presence of the fungus Gaeumannomyces graminis var. tritici causing the take-all of wheat. In the majority of cases when the soil was artificially contaminated by the fungus, both the number of bacteria in the rhizosphere and the bacteria/fungi ratio temporarily increased. At the beginning bacteria growing in the presence of NH4+ predominated, later bacteria utilizing organic N-substances prevailed. Pseudomonas fluorescens and the related species colonized the rhizosphere and the soil to a greater extent in the presence of G. graminis. The wheat rhizosphere with G. graminis was found to contain a higher level of the slime-producing bacterium Agrobacterium spp.; this microorganism occurred on hyphal surfaces (in hyphosphere) of both G. graminis growing in soil and Mucor spp. Changes in microbial populations in the wheat rhizosphere during the first stage of colonization by G. graminis can be partly explained by a simultaneous rhizosphere colonization by microorganisms which accompany this fungus in soil. In the period of increase in the number of bacteria in rhizosphere a temporary stimulation of wheat growth was observed.

Summary In laboratory, glasshouse and field experiments, Pythium oligandrum has been identified as a mycoparasite capable of suppressing damping-off pathogens in emerging sugar-beet. Furthermore, in paired cultures with P. oligandrum on agar-plates, the fungi Botrytis cinerea, Acremonium strictum, Acremonium apii, Paecilomyces sp., Penicillium albidum, Phialophora malorum, Scopulariopsis brevicaulis and Humicola fusco-atra, were also distinctly inhibited by P. oligandrum. A smaller inhibitory effect of P. oligandrum was observed on Acremonium vitellinum, Gliocladium roseum and Chaetomium globosum. On the other hand, the fungi Mucor heterosporum, Rhizopus arrhizus and Mortierella sp. were found to be inhibitors of P. oligandrum, although unable to stop its growth. Drechslera sp. (conidial stage of Cochliobolus sativus) and Mucor piriformis proved more effective, entailing the disappearance of the mycoparasite in mixed cultures. However, the inhibitory activity of those fungi, demonstrated on agar plates, was not confirmed in vivo. The inoculation of seeds with mycelium of P. oligandrum + P. ultimum with and without addition of M. piriformis, led us either instance to an increase in both the rate of emergence, and the weight and state of health of the plants involved. In a pot trial, an emergence rate of sugar-beet plants higher than achieved when using a chemical called Agronex Hepta T 30 was attained after the sugar-beet seeds had been treated with a biopreparation of P. oligandrum in liquid form. But the liquid preparation had only a short-lived effect. In powdery form, the biopreparation was found to be more suitable in that respect. The current method of producing of the latter has made it possible to stabilise the component of P. oligandrum oospores without impairing their vitality and infectibility, even after three years' storage. An unusually high production of oospores has been obtained by means of surface stationary cultivation of the mycoparasite and a new procedure to prepare the agent in powdery form. Concentration of the final product varied within the range of 50 to 500 million oospores/g.

Summary 1. Bacteria and Actinomyces neither inhibited nor stimulated the growth of Pythium oligandrum in dual culture studies on agar plates. 2. Small differences were found in the influence of P. oligandrum on bacteria, suggesting their division into three groups: Group I: Xanthomonas sp., Staphylococcus epidermidis, Bacillus sphaericus, B. subtilis, B. pumilis, and Acinetobacter anitratus. No inhibition zones were formed between the colonies of these bacteria and P. oligandrum. P. oligandrum quickly occupied the agar plate and overgrew the colonies of the bacteria. Group II: Pseudomonas sp., Micrococcus luteus, Micrococcus roseus, and Brevibacterium luteum. No inhibition zones were formed between the colonies of the bacteria and P. oligandrum. P. oligandrum quickly occupied the agar plate, but did not grow over the bacterial colonies. Group III: Bacillus cereus, B. cereus subsp. mycoides, B. megaterium, and Brevibacterium sp. Indistinct inhibition zones were formed between the bacterial colonies and P. oligandrum. Lysis of the mycelium was found in some parts of the P. oligandrum growth. 3. An indistinct inhibition zone was also formed between the colonies of Streptomyces sp. and P. oligandrum. The P. oligandrum growth occupied the whole agar plate and usually overgrew the colonies of Actinomyces. 4. P. oligandrum strongly inhibited Rhizoctonia solani, thus prerenting its growth dual cultivation of both fungi. P. oligandrum did not produce any fruiting organs and no enwrapping of hyphae was found. 5. P. oligandrum entirely occupied the substrate and did not allow further growth of Fusarium culmorum by the fourth day after inoculation. 6. P. oligandrum strongly inhibited Trichoderma viride and T. koningii and reduced their development in dual cultivation. P. oligandrum did not produce any fruiting organs and no enwrapping of hyphae was found.

The toxinogenicity of 720 fungal isolates was evaluated using the Chisk Embryotoxicity Screening Test (CHEST, phase I). Three hundred and sixteen (43.9%) isolates produced some of the 23 identified mycotoxins, unidentified toxic metabolites were produced by 170 (23.6%), and 234 (32.5%) isolates showed no signs of toxinogenicity. The 24 h lasting chick embryo assay proved very suitable for detecting fungal products with general cytotoxic potential where it yielded results consistent with those obtained with cell cultures and higher organisms. Simplicity, rapidity, and modest laboratory equipment belong to the advantages of this reliable and non expensive screening procedure.

The nucleation of cracks by a spark discharge was studied using optical and transmission electron microscopy. It was found that in molybdenum single crystal dislocations are produced by the spark discharge and low angle boundaries are found on {100} and {110} planes. It is proposed that the high density of dislocations in these walls may be responsible for the initial crack nucleation. The crack tip in thin foils as well as in bulk specimen was always found to be blunted by plastic deformation. In a few cases in the bulk specimens re-nucleation of crack at the crack tip was observed and seemed to be related to twinning. Die Keimbildung von Rissen durch Funkenentladung wurde mittels optischer Mikroskopie und Durchstrahlungselektronenmikroskopie untersucht. Es wurde gefunden, das in Molybdaneinkristallen Versetzungen durch Funkenentladungen hervorgerufen werden. Auf {100}- und {110}-Ebenen wurden Kleinwinkelgrenzen beobachtet. Es wird angenommen, das die hohe Dichte der -Versetzungen in diesen Wanden fur die ursprungliche Risbildung verantwortlich sein kann. Es wird gefunden, das die Risspitzen sowohl in dunnen Schichten als auch in massiven Proben immer durch plastische Deformation abgestumpft werden. In einigen Fallen wurde in den massiven Proben erneute Keimbildung der Risse an der Risspitze beobachtet, was mit Zwillingsbildung verknupft zu sein scheint.

The slip geometry in molybdenum has been studied at room temperature by tensile deformation of thin foils under an electron microscope. The orientation of the tensile axis was in the middle of the stereographic triangle, consequently the system with maximum resolved shear stress was (101) [111]. Observations have shown that the choice of slip systems depends not only on the orientation factor of the slip systems but very strongly on the orientation of the foil plane. In the present work this phenomenon is explained by assuming that the difference in the mobilities of screw and edge dislocations is sufficiently large to influence the choice of slip systems. The most active systems are those where the dislocation loops can easily lose their screw component to the surface leaving the edge component to propagate through the foil. Die Gleitgeometrie von Molybdan wurde bei Zimmertemperatur durch plastische Deformation dunner Folien im Elektronenmikroskop untersucht. Die Orientierung der Dehnungsachsen war im Mittelpunkt des stereographischen Dreiecks, somit war das System mit maximal aufgeloster Scherspannung stets ein (101) [111]-System. Beobachtungen haben gezeigt, das die Auslese von Gleitsystemen nicht nur vom Orientierungsfaktor des Gleit-systems, sondern sehr stark von der Orientierung der Folienebene abhangt. Diese Erscheinung wird in dieser Arbeit durch die Annahme erklart, das die Differenzen in den Beweglichkeiten von Schrauben- und Stufenversetzungen gros genug sind, um die Auswahl der Gleitsysteme zu beeinflussen. Die aktivsten Systeme sind die, deren Versetzungsschleifen sehr leicht ihre Schraubenkomponente an die Oberflache verlieren konnen und die Stufenkomponente zum Wandern durch die Folie bestehen lassen.

The activity of 20 mycotoxins was tested by the recently developed initiator tRNA acceptance assay for carcinogens. With the exception of citrinin, all compounds carcinogenic for rodents stimulated the charging of tRNA with L-methionine. In three out of four non-carcinogenic mycotoxins the test was negative. Five carcinogenic mycotoxins were negative in mutagenicity tests but positive in the acceptance assay indicating that also non-mutagenic carcinogens may be detected by the latter procedure.

The embryotoxic potential of ochratoxin A and citrinin was studied after administering, either subgerminally or intraamniotically, single mounting doses of the mycotoxins to chicken embryos on days 2, 3, and 4. The beginning of the embryotoxicity dose range was found to be between 0.01 to 0.05 microgram for ochratoxin A and 1 to 10 micrograms for citrinin. The maximum response to both mycotoxins occurred after administration on day 3. In addition to significant growth retardation of fetuses, exencephaly, microphthalmia, cleft beak, reduction deformities of the limbs, and abdominal wall and ventricular septal defects were encountered on day 8 of incubation. When 4 micrograms of citrinin was constantly added to ochratoxin A administered in the dose range of 0.03 to 0.5 microgram, a strictly additive effect was seen. It may be supposed that citrinin produced together with ochratoxin A in some strains of Penicillium viridicatum Westling does not potentiate the clear-cut embryotoxic action of the latter mycotoxin.

Over the years 1983 to 1984, eight strains of Penicillium oxalicum were isolated from feed mixtures for chickens; all of them produced on wheat secalonic acid D (1 to 22 mg X kg-1). As found out, toxic dose of secalonic acid D for two-day, three--day and four-day chicken embryos is 0.90, 2.80 and 3.80 micrograms, respectively. Teratogenic effects, microophthalmia and bilateral beak fissure was observed in the embryotoxicity range on all days of application.

In the experiment the goat was administered an amount of 450 mg aflatoxin B1. The milk taken during the experiment was lyophilized and aflatoxins B1 and M1 were isolated. After the death of the goat some tissues, blood and bile of the experimental animal were analyzed to find out the aflatoxin content.

The authors describe the finding and identification of ochratoxin A in fodder barley of Czechoslovak produce. The fungus Penicillium verrucosum var. verrucosum, which is an ample producer of ochratoxin A, was isolated from a sample of barley. The isolated fungus was cultivated on several substrates at different temperatures and the production of ochratoxin A was studied during cultivation. The authors believe that the ochratoxicoses of farm animals may also occur in Czechoslovakia and that it would be useful to study this mycotoxin in selected feeds.

The embryotoxicity of aflatoxins B1, B2, G1, G2 and M1 was investigated after administration to chick embryos on either Day 2, 3 or 4. Treatment resulted mainly in embryolethality and a rank order for embryotoxicity was established where B1 greater than G1 greater than M1 = B2 greater than G2. The sensitivity of embryos to aflatoxin administration decreased with their age. These results document the general cytotoxic character of aflatoxin action upon the embryonic morphogenetic systems, actions that apparently require neither specific metabolic activation nor any specific target.

Embryos of White Leghorn Fowls incubated for 40 h were injected subgerminally with 19 mycotoxins dissolved in 30% ethanol to provide a range of doses. Embryonic death as well as the incidence of caudal-trunk abnormalities were determined after a further 24 h incubation. Of the substances tested, the maximum toxic effects were exerted by T-2 toxin and diacetoxyscirpenol which produced 100% embryonic mortality at doses as low as 0.01 microgram. 100 micrograms of griseofulvin, on the other hand, were needed to achieve the same effect. Abnormal development of the caudal trunk was observed after T-2 toxin and diacetoxyscirpenol (0.001 micrograms each) and griseofulvin (10 micrograms) administration. Comparison of these data with results published for both cell and tissue culture techniques and for classical rodent acute toxicity tests reveals a high predictive value for the Chick Embryotoxicity Screening Test (CHEST I), at least for mycotoxins.

Material milled and sampled in 1986 in one Prague flour mill included two flour batches contaminated with a toxicogenic strain of Penicillium islandicum Sopp. P. islandicum, cultivated under experimental conditions, yielded the total of eight grams of chloroform extract containing three grams of luteoskyrin from a kilogram of wheat. The effective dose of chloroform extract was 0.8 microgram (0.5-1.8) for a two-day old chicken embryo, 2.0 microgram (1.7-2.6) for a three-day old embryo and 2.8 micrograms (1.7-4.7) for a four-day old embryo. On all days of administration the chloroform extract had a strong teratogenous action. The most frequent malformations included microophthalmia and anophthalmia, cerebral hernia, bilaterally cleft beak, and reduction deformities of the extremities.

In 1979 to 1983, 148 strains of Penicillium cyclopium were isolated from wheat and from poultry feed mixtures; 11.5% of these strains produced cyclopiazonic acid at the rate of up to 500 mg per kg of wheat. Forty-seven percent of the 96 isolates of Aspergillus flavus and 56% of the nine isolates of Penicillium griseofulvum produced cyclopiazonic acid at the maximum rate of 80 and 10 mg per kg. The ED50 of cyclopiazonic acid for two, three and four days old chicken embryo was found to be 2.40, 4.70 and 2.70 micrograms, respectively. Teratogenic effects were observed only in the two days old embryos in which the caudal end of trunk was shortened at the frequency of 0.36 and microophthalmia occurred at the frequency of 0.33. The LD50 of cyclopiazonic acid in day-old cockerels was found to be 21.71 mg per kg of weight.

In agar plate tests antagonists Gliomastix cerealis and Gliocladium roseum were ineffective against Phoma exigua var. foveata . However, this phytopathogen was very effectively suppressed by the Pythium oligandrum Drechsler. An in vivo trial was conducted to elucidate the effect of treatment of potato seed with the powdery preparation Polygandron containing the Pythium oligandrum oospores, on the incidence of Phoma exigua var. foveata rot in potato tubers of the stored potato seed.

Twenty-seven samples of fodder wheat from the 1980 harvest, visibly attacked by mould, were analyzed for the content of zearalenone. Zearalenone was found to be present in ten samples and its content ranged from 50 to 1300 micrograms per kg. One of the five samples of pelleted feeds, taken at random, contained 14 mg zearalenone per kg. Fifty-three moulds of the genus Fusarium were isolated from the feeds. Among the 19 moulds of F. graminearum, 15 produced zearalenone; 11 moulds of F. culmorum produced zearalenone in all cases, and of the two moulds of F. tricinctum one produced zearalenone. Ten moulds of F. oxysporum, eight moulds of F. sporotrichioides and three molds of F. moniliforme did not produce any zearalenone. Under the described conditions the tested moulds produced 200 to 1200 mg of zearalenone per 1 kg.

Feeding the maize silage infected with the mold Penicillium roqueforti resulted in 112 dairy cows in the loss of appetite, stoppage of rumen activity and gut inflammation. The abortion of first-calvers in the seventh and eighth month was observed. The mold P. roqueforti produced on the sterile maize silage, at the temperature of 20 degrees C, up to 160 mg of PR-toxin per kg after 22 days of cultivation. The maximum production in the liquid medium was 900 mg of PR-toxin per litre, at the temperature of 13 degrees C after 50 days of cultivation. The isolated PR-toxin was identified spectrophotometrically and by the thin-layer chromatography after detection by 3-methyl-2-benzothiazoline-hydrochloride. The dose of 0.01 microgram PR-toxin was extremely toxic for 40-hr old chicken embryos.U

In connection with investigations of an occurence of potential mycotoxin producing moulds in the foodstuffs of the Czechoslovak Socialistic Republic the authors have followed the occurence of A. ochraceus strains in them and the ability of isolated strains to produce ochratoxin A in vitro. From 14708g of different kinds of foodstuffs and from 6757 on surface sterilized cereal and maize grains of Central European origin A. ochraceus have been isolated only 27 times, from 492g of foodstuffs and 8430 on surface sterilized green coffee beans imported from the tropical and subtropical countries 917-times. 11 (36.6%) from 30 tested strains, isolated from imported foodstuffs and coffee beans were producers of ochratoxin A in vitro, not a single strain of 20 tested strains from foodstuffs of domestic origin didn't produce ochratoxin A. On the basis of the obtained results the authors come to the conclusion, that in the foodstuffs of Central European origin the ochratoxin A producing A. ochraceus strains don't play probably an active role.