The High-Low Arctic boundary: How is it determined and where is it located?

Geobotanical subdivision of landcover is a baseline for many studies. The High-Low Arctic boundary is considered to be of fundamental natural importance. The wide application of different delimitation schemes in various ecological studies and climatic scenarios raises the following questions: (i) What are the common criteria to define the High and Low Arctic? (ii) Could human impact significantly change the distribution of the delimitation criteria? (iii) Is the widely accepted temperature criterion still relevant given ongoing climate change? and (iv) Could we locate the High-Low Arctic boundary by mapping these criteria derived from modern open remote sensing and climatic data? Researchers rely on common criteria for geobotanical delimitation of the Arctic.

A randomized trial assessing the efficacy, immunogenicity, and safety of vaccination with live attenuated varicella zoster virus-containing vaccines: ten-year follow-up in Russian children.

In Russia, a universal varicella vaccination (UVV) program has not been implemented, and varicella vaccination coverage is low. We assessed the efficacy, antibody persistence, and safety of one- and two-dose varicella vaccination schedules in Russian children with a ten-year follow-up period, as part of an international phase IIIB, observer-blind, randomized, controlled trial (NCT00226499). Children aged 12-22 months were randomized (3:3:1) to receive two doses of tetravalent measles-mumps-rubella-varicella vaccine (V2 group), one dose trivalent measles-mumps-rubella (MMR) vaccine and one dose of varicella vaccine (V1 group), or two doses of MMR vaccine (V0 [control] group), 42 days apart.

[Interacting insulators from the Drosophila melanogaster bithorax complex can form independent expression domains].

Regulatory region of three bithorax complex genes, Ultrabithorax (Ubx), abdominal-A (abd-A), and Abdominal-B (Abd-B) can be divided into nine iab domains, capable of directing expression of one of the genes in certain abdominal parasegment of Drosophila. In the Abd-B regulatory region, three insulators were identified, including Fab-7 and Fab-8, which flanked the iab-7domain, and Mcp, which separated the Abd-B and abd-A regulatory regions. It was suggested that boundary insulators formed a barrier between active and repressed chromatin.

Structure and variability of spinning reaction waves in three-dimensional excitable media.

A mathematical simulation for a reaction wave that propagates in a cylindrical sample is performed. The propagation modes that have not yet been observed experimentally are predicted. The areas of existence for these modes have been determined.

[Change of isoforms' spectrum of alpha-L-fucoside secreted by affected cells in some hereditary lysosomal diseases].

In vitro it was studied the isoform spectra of the intracellular and secreted alpha-L-fucosidase from skin fibroblasts of patients with Fabry disease (glycolipidosis), Hurler and Sanfilippo D diseases (mucopolysaccharodosis, types I and III) and in the normal state was studied. It was shown that the multiple form profile of secreted alpha-L-fucosidase in patients fibroblasts was changed as compared to that in control: the pathological cells were characterized by expression of more basic isoforms of alpha-L-fucosidase. The changes were similar to those in sucrose-loaded normal cells, modelling storage disease.

Change of isoforms' spectra of alpha-L-fucosidase from human skin fibroblasts in intracellular storage of nonhydrolyzable substances.

The effect of exogenous and endogenous products storage in lysosomes on the activity and multiple forms of alpha-L-fucosidase from human skin fibroblasts was investigated. It was shown that sucrose load, modelling intralysosomal accumulation of nonhydrolyzable products, causes certain changes in secretion level of alpha-L-fucosidase and multiple forms' spectra of the intracellular and secreted enzymes. These changes were different for the enzyme from embryonal and postnatal normal fibroblasts.

Comparative studies of intracellular activity, secretion and multiple forms spectra of human skin fibroblast alpha-L-fucosidase in the normaland after sucrose load.

Activity and multiple forms of intracellular and secreted alpha-L-fucosidases from human skin fibroblasts were studied in normal and sucrose-loaded cells--modelling intralysosomal nonhydrolyzable products' accumulation in vitro. Certain differences in secretion levels were found after sucrose load for alpha-L-fucosidases from embryonal and postnatal cell lines. Different effects of sucrose load on multiple forms' spectra of the intracellular and secreted alpha-L-fucosidases from embryonal and postnatal fibroblasts were revealed.

Human chorionic beta-mannosidase: comparison with beta-mannosidase from human cultured fibroblasts.

The conditions for assay of beta-mannosidase activity in human chorionic villi (CV) were studied using the fluorogenic substrate 4-methylumbelliferyl-beta-D-mannopyranoside. A comparison of the biochemical properties of the CV beta-mannosidase with those of the enzyme from human cultured fibroblasts showed their similarity. Like the enzyme from skin fibroblasts, the CV beta-mannosidase had rather high activity.

[Beta-mannosidase of trophoblast and humana skin fibroblasts].

Conditions for assay of beta-mannosidase activity in human chorionic villi were studied using the fluorogenic substrate 4-methylumbelliferyl-beta-D-mannopyranoside. Comparison of the biochemical properties of the chorionic villi beta-mannosidase with those of the enzyme from human cultured fibroblasts showed their similarity. Like the enzyme from skin fibroblasts, the chorionic villi beta-mannosidase had rather high activity.

[Changes in the organization of the intermediate filament system of human fibroblasts in lysosomal storage diseases and their modeling].

The organization of the system of the vimentin intermediate filaments (IFs) in human fibroblasts in lysosomal storage diseases (Fabry's disease, mannosidosis) and their modelling has been studied in vitro. It was shown that during accumulation of nonhydrolyzable compounds, hypertrophy of the lysosomal compartment is accompanied by formation of ring-shaped bundles IFs, surrounding apparently these increased organelles. The changed organization of IFs is characteristic of polarised pathological cells in monolayer, and after repassage it is retained only at the spreading state; on transition from the discoid to extended cellular form there occurred the centrifugal shift of ring-shaped structures of IFs to active cell border and gradual restoration of radial fibrillar state of IFs.

[Intravital determination of pH gradient between the cytoplasm and lysosomes in human fibroblasts in the normal state and in hereditary storage diseases].

Presented are the results of measurements of pH in cytoplasm and lysosomes of skin fibroblasts of healthy donors and patients with lysosomal storage diseases, mannosidosis, Fabry, Krabbe disease. The pH value was estimated in the stationary phase of growth using neutral red (lysosomes) and fluorescein diacetate (cytoplasm). It was shown that the cytoplasmic pH value in pathological cells didn't virtually differ from the control values.

Estimation and comparison of lysosomal and cytoplasmic pH of human fibroblasts from healthy donors and patients with lysosomal storage diseases.

Measurements were made of the pH of cytoplasm and lysosomes of cultured skin fibroblasts from healthy donors and from patients with lysosomal storage diseases (mannosidosis, Fabry's disease, and Krabbe's disease), and the effects of sucrose loading on normal fibroblasts were studied. The cytoplasmic pH of the pathological cells did not differ from control values, but the intralysosomal pH was significantly higher in sucrose-loaded normal fibroblasts and in cells from a patient with mannosidosis and from another with Fabry's disease. The change in pH observed accorded with an increase in size of the organelles, owing to accumulation of nonhydrolyzable compounds.

[A pH increase in human fibroblast lysosomes during accumulation of non-hydrolysable compounds].

The changes in intralysosomal pH were measured in the stationary phase of normal human embryonic fibroblast growth under sucrose loading over a period of 6 to 120 hours and in cells with a typical lysosomal storage pathology, Fabry's disease, using a vital indicator dye, neutral red. It was shown that long-term hypertrophy of the lysosomal compartment during intracellular accumulation of non-hydrolysable compounds is concomitant with a pH increase, on the average, by 0.4 units.

[Change in intracellular activity and secretion of various lysosomal glycosidases of human fibroblasts cultured in medium with sucrose].

Intracellular activation of lysosomal glycosidases from human skin fibroblasts (alpha-L-fucosidase, beta-D-hexosaminidase, beta-D-galactosidase and beta-D-glucuronidase) was shown to occur on the 3rd-6th days of cultivation in media containing 0.04 M sucrose. The increase in the enzyme activity ranged from 40 to 300% depending on cell strain, nature of enzyme and cultivation time.

[Secretion of alpha-L-fucosidase by human embryonal skin fibroblasts].

The amount of alpha-L-fucosidase secreted by normal human fibroblasts was higher in the medium containing 10% bovine serum than in the medium containing 0.1% bovine serum. Glycosidase secretion was twice higher at the advanced than at the initial stage of subcultivation.

[Intracellular activity and secretion of various lysosomal glycosidases in cultured human skin fibroblasts].

The intracellular activities of four lysosomal glycosidases (alpha-L-fucosidase, beta-D-hexosaminidase, beta-D-galactosidase and beta-D-glucuronidase) in human skin fibroblasts cultured in a medium with 0.1% serum increased in a greater degree than that in a medium with 10% serum. Only two glycosidases (alpha-L-fucosidase and beta-D-hexosaminidase) were secreted by fibroblasts in the culture medium.

[Lysosomal glycosidase activity in cultured human fibroblasts].

A study was made of the activity of 3 lysosomal glycosidases -beta-D-galactosidase (K. P. 3.

[Cells with fragmented nuclei in ascites hepatoma 22A and their participation in proliferation].

The number of cells with fragmented nuclei (FN) (mainly, multilobate) increased with aging of ascites hepatoma 22A (AH22A) as follows: 15 +/- 9.3% in the 6-day AH22A, 196 +/- 53% in the 14-day tumor and 453 +/- 51% in the delayed (18-day) AH22A. The basic way of FN formation was amitotic.

[Binuclear cells in rat liver during repair regeneration of the organ].

At early stages after partial hepatectomy (17 hours after the operation) binuclear cells become involved in proliferation in much lesser numbers, and 37 and 53 hours after the operation--in much greater numbers relative to their part in the population. New formation of binuclear cells (the presence of labeled binuclear cells 20 hours after the thymidine H3 administration) was the most intensive at the early regeneration stages (16--36 hours after the operation), when about 20% of mitoses are acytokinetic and lead to the formation of binuclear cells. At later periods only 8% of mitoses result in formation of binuclear cells.

[Characteristics of the mitotic cycle of cells during the terminal stage of development of ascitic hepatoma 22A].

The authors studied growth peculiarities of the ascitic hepatoma 22A at the terminal stage of development. As shown by the autoradiography method, some of the cells could be at the G1-period or at the R1-period for 2 or even 4 days; the average duration of the G2-period constituted 16 hours. 55--60% of the cells were at the much prolonged G1- and R1-period, 7%--at the S-period, and 9%--at the G2-period.

[Reduction of the prereplicative period of the mitotic cycle in hepatocytes on repeated stimulation of divisions].

Repeated stimulation of division soon after the primary one (2--3 days later) induces a shorteining of the prereplicative phase of the mitotic cylce of hepatocytes to 9--10 hours in the regenerating rat liver. The cells dividing repeatedly after one stimulation were found to pass through the G1-phase of the second mitotic cycle during the same period. It may be suggested that the cells with the minimal duration of the prereplicative phase failed to pass through the transformation period.

[Rate of progress of the 1st post-stimulation division of the mitotic cycle by cells of ascitic hepatoma 22A of different ages].

A study was made of the progress rate of cells of the ascitic hepatoma 22A of different age during the iirst mitotic cycle after the stimulation of division. The "ageing" (11-day), terminal (14-day), and "delayed" (4 days older than the terminal stage) ascitic fluids were used. The maximal values of the labeled nuclei index was found to be reached by 9--12 hours (it was mainly due to the transtion of the quiescent to the S-period) and the maximal mitotic index--by 18--21 hours after the inoculation, independently of the tumour age.

[Regenerative growth of asvitic hepatoma 22A].

A study was made of the recurrent growth of ascite hepatoma 22A, occurring at transplantation of 11-12-day old tumours to new hosts. The mitotic activity of the hepatoma was found to increase by 3 to 4 times (12-15 hours after inoculation). This increased cell proliferation is due mainly to a sharp shortening of all the periods of mitotic cycle.