Play and Intentionality Among Today's Preschoolers

A comparison is made of data on the level of development of play activity and its influence on the volitional behavior of today's preschoolers and the preschoolers of the 1940s–1950s. The results of the comparison point to a substantial decrease in the level of narrative role-playing among children today. The study reproduces the widely known experiment of Z.V. Manuilenko (1948). The comparison of data on preschoolers of the mid-twentieth century and the beginning of the twenty-first shows a significant decrease in the level of volitional behavior in both play and nonplay situations. The results suggest that primitive, underdeveloped play cannot define a zone of proximal development and fulfill the status of primary activity.     

High activity of antioxidant enzymes in a tumor as a factor of "avoidance of control" in the immune system

The enzymes that utilize H2O2 and lipoperoxides as well as the enzymes of the bioregeneration system glutathione and NADP+ have been examined for activity in the superficial and deep regions of DMBA-induced rat fibrosarcoma and the adjoining skeletal muscle. The activities shown by catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase, and glucoso-6-phosphate dehydrogenase were 2-3 times higher and reduced glutathione levels were lower in the superficial than in deep areas. The high antioxidant potential of the tumor superficial areas is proposed to be due to the oxygen-dependent mechanisms by which macrophages and neutrophils select tumor cell clones by the given sign.     

Effects of verapamil on the development of pain syndrome in rats after section of the sciatic nerve]

The effect of daily verapamil administration (5 mg/kg) on pain sensitivity, bioelectric activity of cerebral cortex and microcirculation was studied in rats with cut sciatic nerve. Verapamil untreated rats showed hyperalgesia, autotomies and hypersynchronic discharges in contralateral hemisphere, increased range of evoked potentials and disorders in microcirculatory system which evidence developing pain syndrome. Early introduction of verapamil after the nerve cut prevented the emergence of pain syndrome.     

Cadmium and Nickel Toxicity for <Emphasis Type="Italic">Sinapis alba</Emphasis> Plants Inoculated with Endophytic Strains of <Emphasis Type="Italic">Bacillus subtilis</Emphasis>

We studied the effect of cadmium and nickel on Sinapis alba L. plants inoculated with endophytic strains of Bacillus subtilis. It was shown that treatment of S. alba seeds with endophytic strains of bacteria B. subtilis improves plant resistance to the toxic effect of cadmium and nickel and reduces manifestation of oxidative stress in the presence of higher levels of metal ions in the above-ground part of plants. Anti-stress effect and the ability of endophytic strains of B. subtilis to intensify uptake of cadmium and nickel ions by S. alba plants may be used for phytoextraction of heavy metals and stimulation of plant growth in contaminated areas.     

Isosteric ribavirin analogues: Synthesis and antiviral activities

The novel isosteric ribavirin analogues were synthesized by two different ways. Some of them showed significant antiviral action against hepatitis C virus (HCV), herpes simplex (HCV-1) and influenza A virus comparable to that of ribavirin itself. The data obtained confirm the proposed theory of the ribavirin possible antiviral activity mechanism related with bioisosterism.     

Biomarkers of toxicity in Clarias gariepinus exposed to sublethal concentrations of polycyclic aromatic hydrocarbons

Physiological, biochemical and histological indices in Clarias gariepinus broodstock, and teratogenic indices in embryos exposed to sublethal concentrations of naphthalene, phenanthrene and pyrene were investigated in 2014 using a static-renewal bioassay protocol. Phenanthrene (1.41 mg l^?1) was the most toxic, followed by pyrene (1.53 mg l^?1) and naphthalene (7.21 mg l^?1), based on 96 h LC50 values. Hepatosomatic indices were significantly higher in naphthalene- and pyrene-treated males compared with solvent controls, whereas fecundity in females was significantly lower by factors of 2.4 (naphthalene), 2.8 (phenanthrene) and 2.4 (pyrene), compared with controls. Catalase levels were lower in female phenanthrene-treated fish compared with controls. Histological alterations observed in PAH-treated fish include oedema, inflammatory cells, epithelial lifting and hyperplasia in the gills, vacuolation, haemosiderin pigments and sinusoidal congestion in the liver, and degenerated zona radiata in the ovary. Teratogenic effects were not observed, as evidenced by the lack of histological alterations in embryos spawned from pre-exposed broodstock. Sex-specific responses and the utility of biomarkers at cellular and individual levels of organisation are therefore demonstrated for holistic evaluations of polycyclic aromatic hydrocarbons in ecotoxicological studies.