Effect of change in activity level of catecholaminergic systems on motor, respiratory, and cardiac activities in rat embryos

Parameters of motor, respiratory and cardiac activities were studied in rat embryos (E17-20) after changes in activity level of catecholaminergic systems. To produce conditions for excessive level of catecholamines, the animal were administered individually with preparation of L-DOPA at doses of 25, 50 and 100 mg/kg. Also studied was action of L-DOPA after blockade of D1-(antagonist - SCH-23390, 0.1 mg/kg), D2-(antagonist - sulpiride, 50 mg/kg) dopaminic, and beta2-(antagonist - propranolol, 1 mg/kg) adrenergic receptors. It was found out in E17-18 that the DOPA administration regardless of dose, while in E19-20 dose-dependently produces continuous generalized activity. Between E18 and E19, ontogenetically new is the appearance in 92 % of embryos of stereotypical head movements (circular movements, lateral and dorso-ventral flexions) following in the nearsecond rhythm. Injection of DOPA to rat embryos increased 2-6 times the number of respiratory movements by the gasping type in E17-20 and decreased the amount of episodes of continuous rhythmical respiration in E19-20. No significant heart rate changes were observed after introduction of DOPA to E17-20. There was noted a tendency for a weak acceleration of the heart rate. The changes in activities of the motor and respiratory systems due to a rise of catecholamine level are not connected with activation of the dopamine system, as they are not reduced by blockade of dopamine receptors.     

Characteristics of continuous cell line 293 used for preparation of antineoplastic agent Cancerolysin]

Certification of continuous cell 293 culture used for cultivation of antineoplastic preparation Cancerolysin was carried out. The seeding and working banks of cells 293 were established and deposited for storage at the Vector Centre. The cells were certified in accordance with the WHO requirements. The cell 293 culture was shown to have high proliferative activity; morphology typical of the line; its karyotype and enzymogram are typical of human cells; the culture is not contaminated with bacteria, fungi, mycoplasms and viruses including oncogenic ones; it has high virus-producing activity; it preserves stability of all the biological properties in long-term cultivation. The seeding and working cell banks were recommended for the use in production of drugs for the treatment of oncologic patients.     

Provision of nestboxes raises the breeding density of Great Tits Parus major equally in coniferous and deciduous woodland

Nestbox provision is a technique used to increase nest-site availability for secondary cavity-nesting birds. However, little is known about the demographic consequences of nestbox provision in different habitat types. To assess how nestbox provision affects the density of hole-nesting birds simultaneously in two contrasting habitats, we compared the breeding density of Great Tits along transects without nestboxes with that in transects where nestboxes were provided. Although the initial density of breeders was considerably higher in the deciduous habitat than in the coniferous habitat, provision of nestboxes increased density by a similar number of additional pairs in each habitat type. Thus, the provision of nestboxes in managed coniferous forests may be as effective in increasing the breeding opportunities of cavity nesters as in deciduous stands. Moreover, previous research showed that pairs in deciduous habitat with nestboxes have consistently lower breeding success than those in coniferous habitat with nestboxes. It is possible that the addition of nestboxes in the preferred habitat increased density to such an extent that density-dependent effects became apparent.     

Effect of gametocidal chromosome 4S' on the phenotype segregation ratio in genetic analysis of common wheat lines

Using experimental data on genetic analysis of introgressive lines for the character "hairy leaf sheath" controlled by the "cuckoo" chromosome 4S1, the algorithm for calculation of the theoretical segregation ratio in F2 was developed. Segregation distortion is caused by non-viability of the majority of gametes lacking the chromosome 4S1. The frequency of functioning gametes without the chromosome 4S1 is determined by the probability p versus the theoretically expected ratio 7 nonviable: 9 viable ones. Since segregation involves two characters, gamete viability and hairiness, the ratio 15 hairy: 1 hairless was used as a basis for search of the frequency p by maximum-likelihood method using 16 populations F2 from crossing the lines differing in the character studied.