The Periodically Graded Metal–Insulator–Metal Gap Structure for Plasmonic Waveguides

In this paper, we explore the potential of the plasmonic metal–insulator–metal (MIM) periodically graded structure. Based on the coupled modes approach, an analytical model has been observed for the surface plasmon polariton (SPP) propagation. The band modes of SPP can be also supported by the MIM structure and we have analyzed the strong dependence of band width on structure parameters. The obtained analytical expressions allow one to easily choose the structure parameters for the desired band width.     

Chromothripsis in Hepatocarcinogenesis: The Role of a Micronuclear Aberration and Polyploidy

In this study, we used the mouse model of chemically induced hepatocarcinogenesis to investigate the chromosomal aberrations in hepatic cells. The model was obtained by combined treatment of mice with Dipin (radiomimetic drug) followed by partial hepatectomy. Cytological analysis of isolated liver cells treated with Dipin has demonstrated a number of hepatocytes with structural nuclear abnormalities and multiple micronuclei. Karyotype analysis of polyploid hepatocytes has shown numerous chromosomal aberrations including alleged morphological manifestations of chromothripsis, a special type of genomic reorganization characterized by the local disintegration of chromosomes. Micronuclei with chromosomal fragments have developed as a result of double-strand DNA breaks and might serve as the initial substrate for chromothripsis. The emergence of micronuclei containing chromosomal fragments is the most important result of the treatment employed. Therefore, the presented model of liver cancer (hepatocarcinogenesis) can be used to study the process of chromothripsis in the future.     

Role of Intrinsic and Extrinsic Factors in the Regulation of the Mitotic Checkpoint Kinase Bub1

The spindle assembly checkpoint (SAC) monitors microtubule attachment to kinetochores to ensure accurate sister chromatid segregation during mitosis. The SAC members Bub1 and BubR1 are paralogs that underwent significant functional specializations during evolution. We report an in-depth characterization of the kinase domains of Bub1 and BubR1. BubR1 kinase domain binds nucleotides but is unable to deliver catalytic activity in vitro. Conversely, Bub1 is an active kinase regulated by intra-molecular phosphorylation at the P+1 loop. The crystal structure of the phosphorylated Bub1 kinase domain illustrates a hitherto unknown conformation of the P+1 loop docked into the active site of the Bub1 kinase. Both Bub1 and BubR1 bind Bub3 constitutively. A hydrodynamic characterization of Bub1:Bub3 and BubR1:Bub3 demonstrates both complexes to have 1:1 stoichiometry, with no additional oligomerization. Conversely, Bub1:Bub3 and BubR1:Bub3 combine to form a heterotetramer. Neither BubR1:Bub3 nor Knl1, the kinetochore receptor of Bub1:Bub3, modulate the kinase activity of Bub1 in vitro, suggesting autonomous regulation of the Bub1 kinase domain. We complement our study with an analysis of the Bub1 substrates. Our results contribute to the mechanistic characterization of a crucial cell cycle checkpoint.     

Secretory granules from different glands contain neurocuprein-like protein

Secretory granules obtained from bovine pituitary, atrium and adrenal medulla contain an extremely acidic copper protein resembling by its main physico-chemical and antigenic properties as well as by the ability of its apoform to inhibit dopamine beta-monooxygenase the protein from brain, neurocuprein.     

Enzymatic nanoreactors for environmentally benign biotransformations. 1. Formation and catalytic activity of supramolecular complexes of laccase and linear-dendritic block copolymers

We describe the construction of enzymatic nanoreactors through noncovalent envelopment of a glycoprotein by amphiphilic linear-dendritic AB or ABA copolymers. The synthetic procedure is based on the regioselective adsorption of dendritic poly(benzyl ether)-block-linear poly(ethylene glycol)-block-dendritic poly(benzyl ether) or linear poly(ethylene oxide)-block-dendritic poly(benzyl ether) copolymers onto the oxidative enzyme laccase from Trametes versicolor in aqueous medium. The complexes formed have improved catalytic activity compared with the native enzyme (77-85 nkat/mL vs 60 nkat/mL, respectively) and are more stable at elevated temperatures up to 70 degrees C. Experiments with deglycosylated laccase confirm that the glycoside fragments in the native enzyme serve as the anchor sites for the linear-dendritic copolymers. The enzymatic nanoreactors are able to effectively oxidize series of substrates: phenolic compounds (syringaldazine) and hydrophobic polyaromatic hydrocarbons (anthracene and benzo[a]pyrene) under "green" chemistry conditions.     

Rapid purification of annexin V from human placenta by affinity chromatography

Affinity purification of annexin V from human placenta on column with appropriate monospecific antibodies is developed. The procedure permits purification of the protein to a highly purified state by a two stage procedure. The yield of the protein is about 5 mg per 100 g of wet tissue. Because of high homologies between various annexins, it was supposed that this procedure can be also applied for purification of other annexins from other tissues.     

Some trends in the somatic development of children and adolescents under iodine-deficiency: materials from the Saratov region

2,106 girls and 2,169 boys from 7 to 17 were investigated in 2002-2004 in three urban settlements of the Saratov region (Povolzhje area): the town of Khvalynsk, population 15,000, with a low level of industrialization; the city of Balakovo, population 220,000, highly industrialized and with a nuclear power station; and the city of Saratov, population around 1,000,000 a regional capital, and also highly industrialized. The whole area, particularly the location of Khvalynsk, is also characterized by iodine deficiency (iodine concentration is 0.78 mkg/kg v. normal values of 5-7 mkg/kg).The program included about 30 anthropometric measurements, evaluation of developmental stages of secondary sexual characteristics, and information on menarcheal age by the status quo method. Information on parental occupation and education, as well as number of children per family was collected by questionnaire. For the analysis all the data were standardized, and further comparisons were made irrespective of age groups. The significance of differences was assessed by one-way ANOVA. For height, weight and chest circumference there are significant differences among the three populations (p < 0.001), with Khvalynsk children being the smallest in body height and weight. However, in chest circumference they are close to or even bigger (girls) than Balakovo children. The children from Khvalynsk are characterized by the lowest values for subcutaneous fat layer, both on the trunk and extremities. For the age of menarche, Khvalynsk girls have the highest values: 13 years 5 months (13.42). In Balakovo and Saratov, the corresponding figures are identical: 13 years 2 months (13.17). Secular changes in Khvalynsk and Saratov children are discussed as compared to the literature.     

Dynamic assembly,localization and proteolysis of the <Emphasis Type="Italic">Bacillus subtilis</Emphasis> SMC complex

Background  

SMC proteins are key components of several protein complexes that perform vital tasks in different chromosome dynamics. Bacterial SMC forms a complex with ScpA and ScpB that is essential for chromosome arrangement and segregation. The complex localizes to discrete centres on the nucleoids that during most of the time of the cell cycle localize in a bipolar manner. The complex binds to DNA and condenses DNA in an as yet unknown manner.