Laccase isoform diversity in basidiomycete Lentinus strigosus 1566: Potential for phenylpropanoid polymerization.

Three laccase isoforms with different physicochemical properties could be purified from culture liquid of basidiomycete Lentinus strigosus 1566 obtained during submerged cultivation. The purified laccases possessed individual selectivity in relation to different phenolic compounds. Laccases I, II, and III (59, 65, and 61 kDa respectively) were more active in acidic conditions at around 70 °C. However, in contrast to laccases I and II, laccase III retained its activity (8-30%) and stability during at least one week of incubation at neutral conditions that allows its biotechnological application carried out at neutral environment. The activation phenomena for some of the purified laccases from L. strigosus 1566 during incubation at high temperature, different pH, and sulfates is shown and discussed. According to MALDI-TOF analysis, laccases I and II are most closely related to the laccase of Panus rudis (AAR13230). Transformation of phenylpropanoids by the predominant laccases of L. strigosus 1566 to different polymers was demonstrated, indicating a great potential for producing novel pharmaceutical valuable analogues of lignans, stilbenes, flavonoids, and etc.. The studied laccases, which are products of the same strain, can become a convenient model for further studies of the structural mechanisms of the shift of T-/pH-optima, activation, and T-/pH-stability.

[Selective regulation of laccase isoform production by the Lentinus strigosus 1566 fungus].

The effects of a number of culture medium components, such as peptone, yeast extract, mono- and disaccharides, copper ions, 2,6-dimethylphenol, and polycaproamide fiber, on the laccase activity dynamics in the culture liquid and laccase isoform production by the Lentinus strigosus 1566 fungus were studied. It was demonstrated that some saccharides selectively induced or inhibited the synthesis of different laccase isoforms. Similar action was exerted by copper ions, 2,6-dimethylphenol, and polycaproamide fiber, as well as by their combination. Selective in vivo regulation of the production of certain laccase isoforms by basidial fungi by means of altering the culturing medium composition can be utilised for various biotechnological purposes.

[Monitoring of congenital malformations in children in the Kursk region].

The research established the frequency, spectrum and the prevalence of congenital malformations (CM) in the Kursk region, the analysis of the results of monitoring the CM for the period from 2005 to 2009 has been performed. The evaluation of influence of the major pollutants of air and soil on the possibility of CM arising in children in the Kursk region has been presented.

[The possibility of using neural networks for the 3D visualization of hygienic studies of the health status on the example of the physical development of the child population].

In the course of the research the possibility of using 3d visualization of the results of hygienic investigations using software package STATISTICA Neural Networks as exemplified by the physical development of children in the Kursk region has been demonstrated, assessment of the possibility of application the proposed method has been done.

[Shielding of the geomagnetic field in apartment houses].

The present investigation has studied the specific features of shielding of the natural geomagnetic field (GMF) in the multistorey apartment houses. The results of the experimental study of the shielding properties of some building materials are presented. It is shown that there are 1.2 to 2.0-fold reductions in GMF induction within the houses depending on the number of storeys and the properties of building materials. The level of GMF within the multistorey apartment house decreases by an average of 27.2+/-0.5 microTl from the 1st to the 9th floor and the GMF attenuation factor in many apartment houses exceeds the permissible limit for working places, especially on the top floors. On designing new building materials and constructions and on architectural design, one should keep in mind their shielding properties.

[New efficient producers of fungal laccases].

Two promising strains of laccase producers--Lentinus strigosus 1566 and Steccherinum ochraceum 1833--were found by screening of basidiomycetes. The cultivation conditions increasing the enzyme yield were selected. The maximal laccase activity was observed in the case of submerged cultivation of the mycelium immobilized on polycaproamide fibers in rich media in the presence of 2 mM CuSO4 in combination with the optimal inducer, namely, 2,6-dimethylphenol for L. strigosus and 2,4-dimethylphenol for S. ochraceum. Under these conditions, the activity of S. ochraceum laccase amounted to 33.1 U/ml and that of L. strigosus, to 186.5 U/ml. Anthracene was transformed with S. ochraceum laccase, and its oxidation to anthraquinone was demonstrated by mass spectrometry.

[Hygienic assessment of the use of pesticides in the areas of the Kursk Region].

The paper deals with the evaluation of current trends in the application of pesticides and in the detection of their residues in the environmental objects of the Kursk Region. A reduction in the rate of use of pesticides and changes in their structure and range has been established. The amount of organic chlorides and organic phosphates has been decreased while the use of carbamates, heterocyclic compounds, pyrethroids, the derivatives of azoles, avermectins, meonicotinoids, and the derivatives of aryloxyphenoxypropionic acids increased. The degree of environmental danger of the applied pesticides to human health has decreased by 11.2 times in the past 18 years.

[Ecological threat for human health during the electrical and anomalous geomagnetic fields' influence (review of the literature)].

The work deals with the peculiarities of weak electromagnetic fields' influence on organism. It is shown that in conditions of magnetic anomaly the intensified geomagnetic field is considered to be the main natural principally unavoidable factor. The combination of anomalous and electromagnetic fields as well as their various combinations with other different by nature factors can present certain risk for the health of servicemen and population of magnetic anomaly region.

[Analysis of the kinetics of Ca2+ signals in Ehrlich ascites tumor cells upon the inhibition of the mitochondrial Na+/Ca2+ exchanger]. / Analiz kinetiki Ca2+-signalov v kletkakh astsitnoi kartsinomy Erlikha pri ingibirovanii mitokhondrial'nogo Na+/Ca2+-obmennika.

Signals of cytosolic Ca2+ (Ca2+c) and mitochondrial Ca2+ (Ca2+m) evoked by the activation of purinoreceptors of Ehrlich ascites tumor cells at different extents of inhibition of the mitochondrial Na+/Ca2+ exchanger by tetraphenylphosphonium (TPP+) were investigated. [Ca2+c] was measured by Fura-2 fluorescence, and [Ca2+m] changes were inferred from NAD(P)H fluorescence. The addition of ATP to the cell suspension induced a NAD(P)H response, which replicated Ca2+c signal with some retardation of the peak and a slower decay. In the presence of increasing TPP+ concentrations, NAD(P)H responses evidenced that the rate of [Ca2+m] decay strongly decreases, while the phase of initial rise does not change. The maximal TPP+ dose did not affect [Ca2+c] and NAD(P)H fluorescence in the resting state, as well as ATP-induced [Ca2+c] responses. These data are described in a mathematical model, which accounts for Ca2+ transport through the membranes of endoplasmic reticulum and mitochondria, as well as through the plasma membrane. The model indicates a low rate of the mitochondrial cycle of Ca2+ uptake/efflux at rest and a strong activation of the uptake with increasing [Ca2+c] to which a Hill coefficient of no less than 4 corresponds. Furthermore, the rise of the uptake rate changes in a short time to a decline, and the peak of the rate is markedly ahead of the peak of [Ca2+c].

[Threats to human health in the use of pesticides (a review)]. / Ugrozy zdorov'iu cheloveka pri ispol'zovanii pestitsidov (obzor).

The paper presents current trends in the use of pesticides and detection of their residues in the environmental objects. Pesticides are shown to be a serious health risk factor for different groups of the population when they are irrationally used and inadequately stored. A package of measures to prevent intoxication and to reduce a risk for pesticide entry into the body is provided.

[Hygienic evaluation of the combined effect of electromagnetic fields and pesticides in experimental conditions]. / Gigienicheskaia otsenka sochetannogo deistviia élektromagnitnogo polia i pestitsidov v éksperimente.

The paper deals with the evaluation of combined effects of some natural and anthropogenic factors that are typical of the Kursk magnetic anomaly region by means of dispersion analysis in the experiments on albino rats and mice. The resultant signs were the indices of animal deaths, nonspecific protective factors, immune responses, changes in body weight, etc. A higher geomagnetic field can modify the biological effects of exposure to agricultural chemicals. The combined effects of a static electromagnetic field with induction of 300 microT to 0.3 T and of chlorpyrifos at various concentrations (0.1, 1, 50, and 100 mg/kg) were found to potentiate the toxic properties of the pesticide. The proportion of the potentiation effects increased as the intensity of the studied factors rose. The dispersion analysis established a predominant role of chlorpyrifos in the combined effects of the factors on the death of animals, serum complementary activity, antibody- and rosette-forming cells of the spleen and other lymphoid organs. The role of a static electromagnetic field is prevalent in the formation of effects of the intensity and completeness of phagocytosis.

[Segmental contractile activity of the left ventricle in life threatening arrhythmia]. / Segmentarnaia sokratitel'naia aktivnost' levogo zheludochka pri zhizneopasnykh aritmiiakh.

Intramural pressure (IMP) in the middle segment of the left ventricle and in the apex under ventricular extrasystoles was measured in experiments on the hearts of narcotized dogs. Early extrasystoles caused greater lowering of IMP and blood ejection. Bigeminia was associated with segmental and transmural nonuniformities of IMP which may be due to additional dragging effects in the myocardium. Magnitude of cardiac ejection under extrasystoles depends on nonuniform contractions of the segments of the left ventricle.

[Effects of students' work activities in autumn agricultural teams on their morbidity]. / Vliianie trudovoi deiatel'nosti studentov v osennikh sel'skokhoziaistvennykh otriadakh na ikh zabolevaemost'.

The authors used social studies, timing in order to assess organization and work conditions of manual cotton harvesting by students. Further analysis covered morbidity with transitory disablement among the participants of 8 agricultural teams. Manual cotton harvesting appeared to bring intensive physical strain, awkward working posture, long trips to carry heavy loads in excessive exposure to agrochemical agents. Those hazards induced the growing morbidity. Each third one of the examinees faced transitory disablement. The morbidity structure was opened by respiratory diseases (25.1% of all the cases and 16.9% of all the disablement days), then came gastrointestinal diseases (21.6% and 18.0% respectively), the third place was occupied by neurologic illnesses and disorders of sensory organs (12.8% and 10.1% respectively). The studies proved the activities estimated as an important hazard for the students' health.