The Koryak phase of the Flora development in the Northern Pacific frame

The Koryak phase of the floristic development in the Northern Pacific frame is discussed. Newly obtained data on the Koryak Flora from the Amaam Lagoon area (Northeastern Russia) and Paleocene floras of the Northern Alaska have extended geographic and temporal ranges of the phase. Interregional statuses of the Koryak phase and phytostratigraphic horizon based on this phase, which is traced over the entire Northern Pacific frame and not just the Anadyr-Koryak region as was earlier supposed, are substantiated. The upper boundary of this horizon is defined; the age ranges from the Late Maastrichtian-Danian to Early Selandian.     

Role of the caudate nucleus head in delayed spatial preference and differentiation of trace reflexes in Macaca mulatta

Using phase-correlation analysis, electrical stimulation and pharmacological treatment (Benactyzine), changes in functional importance of the head of n. caudatus have been observed which were related to regulation needs for the delayed spatial preference and differentiation of temporal reflexes. Structural elements of any morpho-functional system are not determined constantly by one and the same functional importance. They may change their functional quality with respect to changes in experimental situation.     

Mathematical modeling of the invagination of epithelial layers in embryogenesis

Biophysics - Invagination of epithelial sheets is an important type of morphogenetic deformation. Primary invagination during gastrulation in the sea urchin provides one of the simplest and...     

Sex differences in the gonadotropins of the Black Sea plaice Scophthalmus maeoticus

No quantitative differences in the effect of acetone-dried pituitaries from male and female plaice upon loach-recipients (Misgurnus fossilis) have been found in testing the activity of the glands on plaice-recipients. This fact suggests the existence of qualitative differences between gonadotropins from plaice males and females. This conclusion was supported in the experiments on the effect of purified gonadotropic fractions, isolated separately from male and female hypophyses, on maturation of the loach. Three gonadotropic fractions obtained by preparative disc-electrophoresis in polyacrylamide gel, differ in their biological activity and electrophoretic mobility. The activity of gonadotropic fractions in males is higher, than in females; electrophoretic mobility of two fractions is also higher in males, whereas the third fraction does not exhibit sexual differences.     

Liposome formulations of combretastatin A4 and its 4-arylcoumarin analogue prodrugs: The antitumor effect in the mouse model of breast cancer

The antimitotic agent combretastatin A-4 (CA-4) has been recently proposed as an antivascular agent for anticancer therapy. In order to reduce systemic toxicity by means of administration in liposome formulations, new lipophilic prodrugs, oleic derivatives of CA-4 and its 4-arylcoumarin analogue (CA4-Ole and ArC-Ole, respectively), have been synthesized in this study. Liposomes with mean diameter of 100 nm prepared on the basis of egg phosphatidylcholine and baker’s yeast phosphatidylinositol quantitatively included up to 15 mol% of CA4-Ole, or 7 mol% of ArC-Ole. To achieve targeting to neovascular endothelium prodrug bearing liposomes decorated with the tetrasaccharide selectin ligand Sialyl Lewis X (SiaLeX) have been also prepared. The antitumor activity was studied in vivo using the model of slow-growing mouse breast cancer. Under the dose used (22 mg/kg) and the administration protocol (four injections, one per a week, starting from the appearance of palpable tumors) cytostatic CA-4 did not reveal any anticancer effect; moreover, it even stimulated tumor growth. The liposome formulations of CA4-Ole did not demonstrate such stimulation. However, to achieve a pronounced antitumor effect, the number of injections of liposomes should be apparently increased. The cytotoxic activity of a novel antimitotic agent ArC was one order of magnitude lower in the human breast carcinoma cell culture in vitro. Nevertheless, in vivo in the mouse model of breast cancer the antitumor effect of this compound corresponded to the double equivalent dose of CA-4. The results demonstrate perspectives of SiaLe^X-liposomes loaded with ArC-Ole: the preparation partially inhibited tumor growth already after the second injection. Thus, subsequent optimization of doses and regimens of administration both for ArC and liposomal ArC-Ole formulations are needed.     

Glycan-binding profile of DC-like cells

Modification of vaccine carriers by decoration with glycans can enhance binding to and even targeting of dendritic cells (DCs), thus augmenting vaccine efficacy. To find a specific glycan-“vector” it is necessary to know glycan-binding profile of DCs. This task is not trivial; the small number of circulating blood DCs available for isolation hinders screening and therefore advancement of the profiling. It would be more convenient to employ long-term cell cultures or even primary DCs from murine blood. We therefore examined whether THP-1 (human monocyte cell line) and DC2.4 (immature murine DC-like cell line) could serve as a model for human DCs. These cells were probed with a set of glycans previously identified as binding to circulating human CD14low/-CD16+CD83+ DCs. In addition, we tested a subpopulation of murine CD14low/-CD80+СD11c+CD16+ cells reported as relating to the human CD14low/-CD16+CD83+ cells. Manα1–3(Manα1–6)Manβ1–4GlcNAcβ1–4GlcNAcβ bound to both the cell lines and the murine CD14low/-CD80+СD11c+CD16+ cells. Primary cells, but not the cell cultures, were capable of binding GalNAcα1–3Galβ (Adi), the most potent ligand for binding to human circulating DCs. In conclusion, not one of the studied cell lines proved an adequate model for DCs processes involving lectin binding. Although the glycan-binding profile of BYRB-Rb (8.17)1Iem mouse DCs could prove useful for assessing human DCs, important glycan interactions were missing, a situation which was aggravated when employing cells from the BALB/c strain. Accordingly, one must treat results from murine work with caution when seeking vaccine targeting of human DCs, and certainly should avoid cell lines such as THP-1 and DC2.4 cells.     

The role of the serum interleukin-2 inhibitor in the rejection of allogeneic hematopoietic tissue in sublethally irradiated mice

The influence of ionizing radiation (5 Gy) on the interleukin-2 inhibitor in mouse serum has been investigated. It has been shown that the concentration of IL-2 inhibitor decreases on days 3-6 and increases considerably on days 10-15 after irradiation. A correlation has been found between the number of T-helpers in spleens of exposed allogenic chimeras and low IL-2 inhibitor content of serum. An attempt has been made to use the increased IL-2 inhibitor level for improving the acceptance of allogenic cells in the sublethally exposed mice.     

Protocol of a prospective study on the diagnostic value of transcranial duplex scanning of the substantia nigra in patients with parkinsonian symptoms

Background  

Parkinson's disease (PD) is the second most common neurodegenerative disorder. As there is no definitive diagnostic test, its diagnosis is based on clinical criteria. Recently transcranial duplex scanning (TCD) of the substantia nigra in the brainstem has been proposed as an instrument to diagnose PD. We and others have found that TCD scanning of substantia nigra duplex is a relatively accurate diagnostic instrument in patients with parkinsonian symptoms. However, all studies on TCD so far have involved well-defined, later-stage PD patients, which will obviously lead to an overestimate of the diagnostic accuracy of TCD.