Chromatin matrix activity in hepatocyte nuclei after disturbance of the hepatic vagal innervation

The level of matrix activity of extranucleolar and nucleolar chromatin in hepatocytes of white noninbred rats has been studied in dynamics after disturbance of the vagal innervation. In order to estimate the labelling intensity of nuclear structures, the histoautoradiographic method is used. After bilateral subdiaphragmal vagotomy at early stages (1-2 weeks) the level of the nucleoplasm and nucleolus increases essentially, and by the 30th day a tendency to its normalization is noted. A conclusion is made that the peripheral nervous system influences the intensity of metabolic processes in the nucleus.     

Globin-coding sequences in the nuclear 28S pre-mRNA and in the cytoplasmic RNA of pigeon erythroid cells

The steady-state content of globin-coding sequences in nuclear and cytoplasmic RNA of pigeon erythroid cells was estimated by hybridization in the excess of nuclear 28S RNA and cytoplasmic poly(A) + RNA with [3H]DNA, synthesized on globin mRNA. Sequences of 9S globin mRNA are found in 0.06% of molecules of non-ribosomal 28S nuclear RNA (pre-mRNA) of erythroblasts and in 0.5% of molecules of non-ribosomal 28S nuclear RNA of reticulocytes. The content of globin mRNA in erythroblast cytoplasm is, respectively lower than in that of reticulocytes.     

Dynamics of the factors of 137Cs transfer to natural and sown grasses in the long term after the accident at the Chernobyl power plant

The regularities of changes in factors of 137Cs transfer to natural and sown grasses in the longterm period after the Chernobyl accident are described. The dynamics of changes in factors of 137Cs transfer to sown grasses over the period of 1993 to 1999 was of a non-uniform character. On average, these transfer factors (TF) tended to decrease in that period. A significant tendency for an increase in TF to sown grasses was noted for 1997-1999. The half-life periods of decrease in TF to natural grasses in the period 1993-1999 were shown to be ranged from 4.6 to 24.6 years. It was demonstrated that the differences in the TF dynamics between sown and natural grasses were related to the peculiarities of their development and application of countermeasures.     

An overview of malaria transmission from the perspective of Amazon Anopheles vectors

In the Americas, areas with a high risk of malaria transmission are mainly located in the Amazon Forest, which extends across nine countries. One keystone step to understanding the Plasmodium life cycle in Anopheles species from the Amazon Region is to obtain experimentally infected mosquito vectors. Several attempts to colonise Ano- pheles species have been conducted, but with only short-lived success or no success at all. In this review, we review the literature on malaria transmission from the perspective of its Amazon vectors. Currently, it is possible to develop experimental Plasmodium vivax infection of the colonised and field-captured vectors in laboratories located close to Amazonian endemic areas. We are also reviewing studies related to the immune response to P. vivax infection of Anopheles aquasalis, a coastal mosquito species. Finally, we discuss the importance of the modulation of Plasmodium infection by the vector microbiota and also consider the anopheline genomes. The establishment of experimental mosquito infections with Plasmodium falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide interesting models for studying malaria in the Amazonian scenario is important. Understanding the molecular mechanisms involved in the development of the parasites in New World vectors is crucial in order to better determine the interaction process and vectorial competence.     

Status of the detoxication function of the liver after vagal denervation

In 14 and 25 days of bilateral subdiaphragmatic+ vagotomy perimeter of the endoplasmic reticulum (EPR) of hepatocytes, content of the enzyme (cytochrome R-450) built into the membrane in microsomal fractions, speed of hydroxylation of substrates and oxygen absorption decreased and the section area of EPR and duration of the hexonal sleep increased. The results demonstrate certain disturbances of the detoxication function of the denervated liver.     

Influence of individual domains of the translation termination factor eRF1 on induction of the GTPase activity of the translation termination factor eRF3

Translation termination in eukaryotes is governed by two proteins, belonging to the class-1 (eRF1) and class-2 (eRF3) polypeptide release factors. eRF3 catalyzes hydrolysis of GTP to GDP and inorganic phosphate in the ribosome in the absence of mRNA, tRNA, aminoacyl-tRNA and peptidyl-tRNA but needs the presence of eRF1. It's known that eRF1 and eRF3 interact with each other in vitro and in vivo via their C-terminal regions. eRF1 consists of three domains - N, M, and C. In this study we examined the influence of individual domains of the human eRF1 on induction of the human eRF3 GTPase activity in the ribosome in vitro. It was shown that none of the N-, M-, C- and NM-domains induces eRF3 GTPase activity in presence of the ribosomes. MC-domain does induce GTPase activity of eRF3 but four times less efficient than full-length eRF1, therefore, MC-domain (and very likely M-domain) binds to the ribosome in the presence of eRF3. Based on these data and taking into account the data available in literature, a conclusion was drawn that the N domain of eRF1 is not essential for eRF1-dependent induction of the eRF3 GTPase activity. A working hypothesis is formulated, postulating that GTPase activity eRF3 during the translation termination is associated with the intermolecular interactions of GTP/GDP, GTPase center of the large ribosomal subunit (60S), MC-domain of eRF1, C-terminal region and GTP-binding domains of eRF3, but without participation of the N-terminal region of eRF3.     

Genetic diversity of chloroquine-resistant Plasmodium vivax parasites from the western Brazilian Amazon

The molecular basis of Plasmodium vivax chloroquine (CQ) resistance is still unknown. Elucidating the molecular background of parasites that are sensitive or resistant to CQ will help to identify and monitor the spread of resistance. By genotyping a panel of molecular markers, we demonstrate a similar genetic variability between in vitro CQ-resistant and sensitive phenotypes of P. vivax parasites. However, our studies identified two loci (MS8 and MSP1-B10) that could be used to discriminate between both CQ-susceptible phenotypes among P. vivax isolates in vitro. These preliminary data suggest that microsatellites may be used to identify and to monitor the spread of P. vivax-resistance around the world.     

Characterization and transferability of microsatellite markers of the cultivated peanut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis>)

Background  

The genus Arachis includes Arachis hypogaea (cultivated peanut) and wild species that are used in peanut breeding or as forage. Molecular markers have been employed in several studies of this genus, but microsatellite markers have only been used in few investigations. Microsatellites are very informative and are useful to assess genetic variability, analyze mating systems and in genetic mapping. The objectives of this study were to develop A. hypogaea microsatellite loci and to evaluate the transferability of these markers to other Arachis species.     

In vitro and in vivo conditional sensitization of hepatocellular carcinoma cells to TNF-induced apoptosis by Taxol

High mortality among hepatocellular carcinoma (HCC) patients reflects both late diagnosis and low curability, due to pharmacoresistance. Taxol (TAX) is toxic for many human HCC-derived cell lines, yet its clinical efficacy on HCCs is poor. Combining TAX with other drugs appears a promising possibility to overcome such refractoriness. We analyzed whether combining tumor necrosis factor (TNF) with TAX would improve their toxicity. Human HCC-derived cell lines were treated with TAX or TNF, alone or combined. Apoptosis was assessed by morphology and flow-cytometry. Several pro- and anti-apoptotic molecules were evaluated by western blotting and/or enzymatic assay. After a 24 hour treatment, TNF was ineffective and TAX modestly cytotoxic, whereas HCC cells were conditionally sensitized to TNF by TAX. Indeed some relevant parameters were shifted to a prodeath setting: TNF-receptor 1 was increased, SOCS3, c-FLIP and pSTAT3 were markedly downregulated. These observations provide a significant clue to critically improve the drug susceptibility of HCC cells by combining 2 agents, TAX and TNF. The sequential application of TAX at a low dosage followed by TNF for only a short time triggered a strong apoptotic response. Of interest, prior TAX administration could also sensitize to TNF-induced apoptosis in the Yoshida AH-130 hepatoma transplanted in mice. Therefore, scrutinizing the possibility to develop similar combination drug regimens in suitable preclinical models seems highly advisable.