The dmc1 Mutant Allows an Insight Into the DNA Double-Strand Break Repair During Meiosis in Barley (Hordeum vulgare L.)

Meiosis is a process of essential importance for sexual reproduction, as it leads to production of gametes. The recombination event (crossing-over) generates genetic variation by introducing new combination of alleles. The first step of crossing-over is introduction of a targeted double-strand break (DSB) in DNA. DMC1 (Disrupted Meiotic cDNA1) is a recombinase that is specific only for cells undergoing meiosis and takes part in repair of such DSBs by searching and invading homologous sequences that are subsequently used as a template for the repair process. Although role of the DMC1 gene has been validated in Arabidopsis thaliana, a functional analysis of its homolog in barley, a crop species of significant importance in agriculture, has never been performed. Here, we describe the identification of barley mutants carrying substitutions in the HvDMC1 gene. We performed mutational screening using TILLING (Targeting Induced Local Lesions IN Genomes) strategy and the barley TILLING population, HorTILLUS, developed after double-treatment of spring barley cultivar 'Sebastian' with sodium azide and N-methyl-N-nitrosourea. One of the identified alleles, dmc1.c, was found independently in two different M₂ plants. The G2571A mutation identified in this allele leads to a substitution of the highly conserved amino acid (arginine-183 to lysine) in the DMC1 protein sequence. Two mutant lines carrying the same dmc1.c allele show similar disturbances during meiosis. The chromosomal aberrations included anaphase bridges and chromosome fragments in anaphase/telophase I and anaphase/telophase II, as well as micronuclei in tetrads. Moreover, atypical tetrads containing three or five cells were observed. A highly increased frequency of all chromosome aberrations during meiosis have been observed in the dmc1.c mutants compared to parental variety. The results indicated that DMC1 is required for the DSB repair, crossing-over and proper chromosome disjunction during meiosis in barley.

Reduced fecundity and cellular changes in Acheta domesticus after multigenerational exposure to graphene oxide nanoparticles in food

Despite the fact that the demand for graphene and its derivatives in commercial applications is still growing, many aspects of its toxicity and biocompatibility are still poorly understood. Graphene oxide, which is released into the environment (air, soil and water) as so-called nanowaste or nanopollution, is able to penetrate living organisms. It is highly probable that, due to its specific nature, it can migrate along food chains thereby causing negative consequences. Our previous studies reported that short-term exposure to graphene oxide may increase the antioxidative defense parameters, level of DNA damage, which results in numerous degenerative changes in the gut and gonads. The presented research focuses on reproductive dysfunction and cellular changes in Acheta domesticus after exposure to GO nanoparticles in food (concentrations of 20 and 200 μg·g^-1 of food) throughout their entire life cycle. The results showed that long-term exposure to GO caused a significant decrease in the reproductive capabilities of the animals. Moreover, the next generation of A. domesticus had a lower cell vitality compared to their parental generation. It is possible that graphene oxide can cause multigenerational harmful effects.

Assessment of the chemical, microbiological and toxicological aspects of post-processing water from underground coal gasification

The purpose of this paper is to provide a comprehensive characterisation (including chemical, microbiological and toxicological parameters) of water after the underground coal gasification (UCG) process. This is the first report in which these parameters were analysed together to assess the environmental risk of the water generated during the simulation of the underground coal gasification (UCG) process performed by the Central Mining Institute (Poland). Chemical analysis of the water indicated many hazardous chemical compounds, including benzene, toluene, ethylbenzene, xylene, phenols and polycyclic aromatic hydrocarbons (PAHs). Additionally, large quantities of inorganic compounds from the coal and ashes produced during the volatilisation process were noted. Due to the presence of refractory and inhibitory compounds in the post-processing water samples, the microbiological and toxicological analyses revealed the high toxicity of the UCG post-processing water. Among the tested microorganisms, mesophilic, thermophilic, psychrophilic, spore-forming, anaerobic and S-oxidizing bacteria were identified. However, the number of detected microorganisms was very low. The psychrophilic bacteria dominated among tested bacteria. There were no fungi or Actinomycetes in any of the water samples. Preliminary study revealed that hydrocarbon-oxidizing bacteria were metabolically active in the water samples. The samples were very toxic to the biotests, with the TU50 reaching 262. None of biotests was the most sensitive to all samples. Cytotoxicity and genotoxicity testing of the water samples in Vicia uncovered strong cytotoxic and clastogenic effects. Furthermore, TUNEL indicated that all of the water samples caused sporadic DNA fragmentation in the nuclei of the roots.

[Evaluation of some clinic data in patients with tinea versicolor]

Fungi from Malassezia species may be a component of human and animal skin onthocenosis but also may cause general mycoses in patients from high risk groups. The aim of study was the evaluation of some clinic data in patients with tinea versicolor, who entered to Department of Biology and Medical Parasitology, Centre for Treatment of Parasitic Diseases and Mycoses, Medical University of Lodz. Forty four patients with tinea versicolor were examined. Localization and number of skin lesions as well as eventually risk factor were examined. In all patients mycological examine was done; morphotic elements of fungi in direct and stained slides were found, cultures on solid medium with oil olive were done. In Wood light fluorescence of changed skin was observed. The most incidence of tinea versicolor was observed in young persons to compare with to another age groups. The most frequently localization of clinical lesions concerned back skin, back and chest. In women - to compare with to male patients--clinical lesions on back skin were significantly more frequent. The only one factor was conducived to infection--it was a seborrhea of the skin, observed mainly in patients from the youngest age group.

[Susceptibility to miconazole and itraconazole of Candida strains isolated from hospitalized and outpatient clinic patients]

It is known that fungi representing different genera and species can cause organ-limited or systemic infections after disrupting of the natural defense mechanisms in a human organism. The treatment of mycoses still encounters considerable difficulties. Therefore, in vitro assessment of the susceptibility of fungal strains to the antifungal agents now in use and to new drugs is needed more urgently than ever before. It should be emphasized that we treat the fungal susceptibility to antifungal drugs as a quantitative feature of the strain examined. The aim of the presently reported study was the evaluation of the antimycotic action of two azole compounds--miconazole and itraconazole (Janssen) against 205 Candida strains isolated from the various biological specimens of two groups of patients--hospitalized (group 1) and examined in outpatient clinic (group 2); differentiation of species and codes of these strains; analysis of dose-response curves and parameters of polygons of the azoles minimal inhibitory concentrations (MIC). The susceptibility to miconazole and itraconazole was estimated with the agar diffusion test on 3% Sabouraud's agar--the method developed in our laboratory, using several different concentrations of the drug, which made the plotting of dose-response curves possible. The lowest concentration inhibiting the growth of fungal strain (MIC) was calculated using a transformed equation of rectilinear regression according to Kadłubowski. Species and fungal codes of isolated strains were evaluated according to the guidelines worked out in our department with the use of different media and biochemical tests (bioMérieux). Among 89 strains isolated from the hospitalized patients, six species of the genus Candida genus were found; one strain belonged to Trichosporon cutaneum species. The most frequently encountered species was Candida albicans (73%), which significantly dominated over C. tropicalis, C. parapsilosis, C. glabrata, C. lipolytica and C. famata. All strains from the second group of patients belonged to C. albicans species. In all C. albicans strains from both groups of patients, the most frequent assimilation code (2576174) was found. The miconazole MIC values for Candida strains isolated from the group 1 were characterized by a wide range of variation, from 0.0247 mg/l to 6.826 mg/l, from group 2 - 0.0277 to 0.719 mg/l. The itraconazole MIC values were 0.011 to 2.813 mg/l, and 0.0103 to 0.718 mg/l, respectively. The analysis of mean values (x) of miconazole and itraconazole MICs and other parameters allowed us to find that the strains isolated from the patients of group 1 were significantly less susceptible to both drugs in comparison with the strains of the group 2 patients. Also, C. albicans strains from this group of patients had a significantly lower (x) MIC in comparison to the mean values for the most of Candida species isolated from the hospitalized patients (P < 0.001). In conclusion, we have found that the most Candida strains from both groups of patients were susceptible to the examined antifungal agents. The strains isolated from the outpatient clinic patients were generally more susceptible especially to itraconazole in comparison with strains from hospitalized patients.

[Current possibilities of using antimyocotic drugs in the treatment of various skin disorders]

Current possibilities of using antimycotic drugs in the treatment of various skin disorders. The purpose of this article is to review the literature data on the therapeutic protocols and the results of using some antimycotics in different skin diseases. In addition to the antimycotic action, particular antifungal drugs such as itraconazole, ketoconazole and terbinafine exhibit anti-inflammatory activity by inhibiting the synthesis of 5-lipooxygenase metabolites. As these metabolites are involved in a number of inflammatory and immunoreactive processes the dual action of the drugs may be suitably exploited in the treatment of some skin diseases which are otherwise difficult to cure. Another rationale for the use of antimycotics in certain skin disorders is their action against Malassezia. It has been recently demonstrated that Malassezia, present as a commensal in the epidermis, may play an important role in inducing certain inflammatory processes by stimulating cytokine production by keratinocytes. The antimycotics proved to be useful in the therapy of the following skin conditions: seborrheic dermatitis, Malassezia folliculitis, perioral dermatitis and papulopustular rosacea, as well as adult atopic dermatitis. The use of antimycotic drugs in amicrobial palmoplantar pustulosis and sebopsoriasis remains controversial. These medications are also an alternative in the treatment of leishmaniosis.

[The role of fungi in etiopathogenesis of delayed orthopaedic wound healing]

Mycological investigations were carried out in 20 patients due to the delayed wound healing, following orthopaedic surgery at the Department of Orthopaedics, Medical University of Lódź. The material samples for fungal assessment were taken from the wound, surrounding skin and oral cavity. In all patients, the fungi were isolated at least from one ontocenosis; from the wound in 40.0% of subjects studied, from the wound-surrounding skin in 55.0% and from the oral cavity in 85.0%. It should be emphasized that the occurrence of fungi was more frequently observed simultaneously in two or three ontocenoses (70.0%) than in one (30.0%). Unifocal infection was found only in the oral cavity, while the presence of fungi in the wound was accompanied by their appearance in the region of wound-surrounding skin and/or in the oral cavity.

[Fungi in patients with diabetes mellitus type 2: prevalence, species of isolated strains]

In 77 diabetic patients the detection of fungi was carried out in the oral cavity, digestive tract, genital organs and skin lesions. Patient age ranged from 39 to 82 years, with the Body Mass Index (BMI) from 22 to the highest values of 46.5. Diabetes control was assessed by determination of the glucose level in serum after overnight fasting and after lunch, as well as by determination of the HbA(1c) level. Fungi were diagnosed in 61 patients (79.6%). The total of 111 fungal strains were isolated in 319 cultures evaluated from 12 biological materials. Fungal strains were detected in the highest percentage in oral cavity (77.9%), in the lower percentage in anus (33.8%), vagina discharge (11.6%) and the region of vulva (14.3%). Fungi were observed in one focus--exclusively in the oral cavity--in 28 (36.4%) patients, whereas they occurred in multifocal infections in 33 (42.9%) patients. The isolated fungal strains were classified into 4 genera (Candida, Saccharomyces, Trichosporon, Aspergillus) and 12 species. The most frequently detected fungi were C. albicans (55.2%), followed by C. glabrata (12.4%), C parapsilosis (10.5%) and C. tropicalis (9.5%). Relatively low percentage of fungi identified in vagina was associated, among others, with the fact that most of the female patients with diabetes were at the postmenopausal period. In all the patients in whom fungi were isolated from the vagina contents, these fungi were also found in other ontocenoses. The increase in percentage of fungal strains from genera other than Candida in patients with a higher risk is of clinical importance, as some of them are resistant in vitro to azole derivatives e.g. fluconazole. The digestive tract is thought to be the most frequent fungal habitat. A considerable prevalence of fungi, multifocal infections, particularly related to oral cavity and anus, and occurrence of high percentage of strains different from C. albicans species of Candida genus in female patients with type 2 diabetes indicate the necessity of the special mode of diagnostic and therapeutic management.

[Algorithm of diagnostic procedure in candidosis of male genital organs]

The results of earlier own studies performed in male patients with symptomatic candidosis of genital organs enabled to work out an algorithm of diagnostic procedure to determine of the fungal reservoir in a male patient. The study comprised 50 persons: 25 males and 25 female partners with clinical signs of recurrent genital organs candidosis. To mycological examination 6 specimens from males and 5 from females were collected. A total number of 275 cultures was examined. In the 45% of patients fungi were detected in all foci of infection. In the some cases (20%) fungal strains were isolated in males only from ejaculate but from their sexual partners from all examined specimens. Clinical and mycological cure often required more than one administration of oral antifungal agents.

[The capability of deamination of aminoacids by selected strains of fungi]

We have studied the capability of dissociation of 22 L-form aminoacids by 27 strains of fungi belonging to species: Candida, Cryptococcus, Geotrichum, Rhodotorula, Saccharomyces, Trichosporon. Fungal strains were cultured on agar medium with phenyl red and studied aminoacid. Disamination of an aminoacid by a fungus resulted in alkalisation of the medium and change of its colour from yellow to pink. Strains from genus Trichosporon and Geotrichum decomposed the most aminoacids (15-16), while fungi from genus Candida decomposed less aminoacid (1-8). Strains form species Candida famata, C. kefyr, C. lambica. C. rugosa, C. neoformans, R. mucilaginosa and S. cerevisiae did not show any ability to desaminate any of the 22 aminoacids used in the study. Aminoacids most frequently disaminated, by the studied strains of fungi included acidic aliphatic aminoacids and their amides: L-aspartic acid, L-asparagine, L-glutaminic acid, L-glutamine and neutral aliphatic aminoacids: L-glycin, L-alanine, L-serine. Aromatic and sulphur aminoacids (L-cysteine, L-cystine) were not decomposed by the studied fungal strains.