Limited plasticity of the rabbit visual cortex and hippocampal neurons in the oddball test

The activity of 41 visual cortex and 20 hippocampal neurons from field CA1 was registered in experiments using oddball-stimulation with different color stimuli varied in intensity. 34% cortical and 37% hippocampal neurons demonstrated plasticity reactions. The significant increase of latest phases of neuronal activity (200-500 and 200-1000 ms after stimulation for cortical neurons and 300-550 ms for hippocampal neurons) was shown in responses to rare deviant stimuli, which had a less intensity than frequently standards. The quantity of the earliest neuronal phase of activity (40-120 ms after stimulation) was stabilized in responses to deviants and standards during the experiment. We propose that such increase of the latest phases of neuronal activity (the limited plasticity) may reflect the mechanisms of orienting reaction.     

Effect of weightlessness on the indices of brain development (the results of pregnant rats being on the Kosmos-1514 biosatellite and research on the subsequent development of their progeny on Earth)

Beginning from the 13th day of pregnancy the rats were under conditions of weightlessness of spaceflight for 6 days. After landing in 18-day-old fetuses the state of their brain development is investigated comparing to that in control animals, that are on the Earth. As demonstrates analysis of a number of morphological processes: reproduction, migration, neuronal differentiation, growth of processes, establishment of nervous connections, neuroglial interconnections and vascularization--all they under conditions of weightlessness develop rather fully. Certain deviations in vascularization (as examples the medulla oblongata and the striated tuber are taken) are observed--the amount of vessels is greater and they are thinner--and changes in migration rate of cells is demonstrated by the example of the cortical plate formation. These changes are quickly levelled during their subsequent development on the Earth.     

A machine learning approach for the identification of odorant binding proteins from sequence-derived properties

Background  

Odorant binding proteins (OBPs) are believed to shuttle odorants from the environment to the underlying odorant receptors, for which they could potentially serve as odorant presenters. Although several sequence based search methods have been exploited for protein family prediction, less effort has been devoted to the prediction of OBPs from sequence data and this area is more challenging due to poor sequence identity between these proteins.     

Hes1 Increases the Invasion Ability of Colorectal Cancer Cells via the STAT3-MMP14 Pathway

The Notch pathway contributes to self-renewal of tumor-initiating cell and inhibition of normal colonic epithelial cell differentiation. Deregulated expression of Notch1 and Jagged1 is observed in colorectal cancer. Hairy/enhancer of split (HES) family, the most characterized targets of Notch, involved in the development of many cancers. In this study, we explored the role of Hes1 in the tumorigenesis of colorectal cancer. Knocking down Hes1 induced CRC cell senescence and decreased the invasion ability, whereas over-expression of Hes1 increased STAT3 phosphorylation activity and up-regulated MMP14 protein level. We further explored the expression of Hes1 in human colorectal cancer and found high Hes1 mRNA expression is associated with poor prognosis in CRC patients. These findings suggest that Hes1 regulates the invasion ability through the STAT3-MMP14 pathway in CRC cells and high Hes1 expression is a predictor of poor prognosis of CRC.     

Epidemiologic situation of West Nile fever in Russia in 2010

Problem of tropical arbovirus infection--West Nile fever (WNF)--spread in Russian Federation is discussed. Biology of WNF is discussed, WNF sources and reservoir are characterized. WNF outbreaks in Russia during the past 2 decades are presented in detail. Outbreaks of different years, possible causes and epidemiology are discussed. Features of WNF clinical course during various outbreaks and WNF diagnostic problems are presented.     

Combination of dasatinib and curcumin eliminates chemo-resistant colon cancer cells

Metastatic colorectal cancer remains a serious health concern with poor patient survival. Although 5-Fluorouracil (5-FU) or 5-FU plus oxaliplatin (FOLFOX) is the standard therapy for colorectal cancer, it has met with limited success. Recurrence of the tumor after chemotherapy could partly be explained by the enrichment of the chemo-resistant sub-population of cancer stem cells (CSCs) that possess the ability for self-renewal and differentiation into different lineages in the tumor. Therefore development of therapeutic strategies that target CSCs for successful treatment of this malignancy is warranted. The current investigation was undertaken to examine the effectiveness of the combination therapy of dasatinib (a Src inhibitor) and curcumin (a dietary agent with pleiotropic effect) in inhibiting the growth and other properties of carcinogenesis of chemo-resistant colon cancer cells that are enriched in CSCs sub-population. Remnants of spontaneous adenomas from APC ^{Min +/-} mice treated with dasatinib and/or curcumin were analyzed for several cancer stem cell markers (ALDH, CD44, CD133 and CD166). Human colon cancer cells HCT-116 (p53 wild type; K-ras mutant) and HT-29 (p53 mutant; K-ras wild type) were used to generate FOLFOX resistant (referred to as CR) cells. The effectiveness of the combination therapy in inhibiting growth, invasive potential and stemness was examined in colon cancer CR cells. The residual tumors from APC ^{Min +/-} mice treated with dasatinib and/or curcumin showed 80-90% decrease in the expression of the CSC markers ALDH, CD44, CD133, CD166. The colon cancer CR cells showed a higher expression of CSCs markers, cell invasion potential and ability to form colonospheres, compared to the corresponding parental cells. The combination therapy of dasatinib and curcumin demonstrated synergistic interactions in CR HCT-116 and CR HT-29 cells, as determined by Calcusyn analysis. The combinatorial therapy inhibited cellular growth, invasion and colonosphere formation and also reduced CSC population as evidenced by the decreased expression of CSC specific markers: CD133, CD44, CD166 and ALDH. Our data suggest that the combination therapy of dasatinib and curcumin may be a therapeutic strategy for re-emergence of chemo-resistant colon cancer by targeting CSC sub-population.     

Choline acetyltransferase activity of spinal cord cell cultures increased by co-culture with muscle and by muscle-conditioned medium

Activity of the enzyme choline acetyltransferase (CAT), which mediates the synthesis of the neurotransmitter, acetylcholine, was increased up to 20- fold in spinal cord (SC) cells grown in culture with muscle cells for 2 wk. This increase was directly related to the duration of co-culture as well as to the cell density of both the SC and muscle involved and was not affected by the presence of the acetylcholine receptor blocking agent, α-bungarotoxin. Glutamic acid decarboxylase (GAD) activity was often markedly decreased in SC-muscle cultures while the activities of acetylcholinesterase and several other enzymes were little changed. Increased CAT activity was also observed when SC cultures were maintained in medium which had been conditioned by muscle cells or by undifferentiated cells from embryonic muscle. Muscle-conditioned medium (CM) did not affect the activities of SC cell GAD or acetylcholinesterase. Dilution or concentration of the CM directly affected its ability to increase SC CAT activity , as did the duration and timing of exposure of the SC cells to the CM. The medium could be conditioned by muscle cells in the presence or absence of serum, and remained effective after dialysis or heating to 58 degrees C. Membrane filtration data were consistent with the conclusion that the active material(s) in CM had a molecular weight in excess of 50,000 daltons. We conclude that large molecular weight material that is released by muscle cells is capable of producing a specific increase in CAT activity of SC cells.     

Rat testicular germ cells and sertoli cells release different types of bioactive transforming growth factor beta in vitro

Several in vivo studies have reported the presence of immunoreactive transforming growth factor-β's (TGF-β's) in testicular cells at defined stages of their differentiation. The most pronounced changes in TGF-β₁ and TGF-β₂ immunoreactivity occurred during spermatogenesis. In the present study we have investigated whether germ cells and Sertoli cells are able to secrete bioactive TGF-β's in vitro, using the CCl64 mink lung epithelial cell line as bioassay for the measurement of TGF-β. In cellular lysates, TGF-β bioactivity was only observed following heat-treatment, indicating that within these cells TGF-β is present in a latent form. To our surprise, active TGF-β could be detected in the culture supernatant of germ cells and Sertoli cells without prior heat-treatment. This suggests that these cells not only produce and release TGF-β in a latent form, but that they also release a factor which can convert latent TGF-β into its active form. Following heat-activation of these culture supernatant's, total TGF-β bioactivity increased 6- to 9-fold. Spermatocytes are the cell type that releases most bioactive TGF-β during a 24 h culture period, although round and elongated spermatids and Sertoli cells also secrete significant amounts of TGF-β. The biological activity of TGF-β could be inhibited by neutralizing antibodies against TGF-β₁ (spermatocytes and round spermatids) and TGF-β₂ (round and elongating spermatids). TGF-β activity in the Sertoli cell culture supernatant was inhibited slightly by either the TGF-β₁ and TGF-β₂ neutralizing antibody.These in vitro data suggest that germ cells and Sertoli cells release latent TGF-β's. Following secretion, the TGF-β's are converted to a biological active form that can interact with specific TGF-β receptors. These results strengthen the hypothesis that TGF-β's may play a physiological role in germ cell proliferation/differentiation and Sertoli cell function.     

Structure of the centriole complex in mouse hepatocytes in the experimental induction of a G2 block

In the regenerating liver hepatocytes the centriolar cycle is retarded corresponding to the delay of the nuclear cycle up to the beginning of G2-block. A prolonged staying of cells in the premitotic condition results in the phenomenon that according to their DNA these cells correspond to the G2-period, whereas according to their centriolar complex structure they move into the following G1 and G0-periods, passing mitosis. Thus, in the G2-blocked hepatocytes there is a separation of the nuclear cycle and centriolar cycles. Moreover, during the diping action the centriolar capacity of forming cytoplasmic and mitotic microtubules is suppressed.