Ketamine-induced tongue protrusions in rats

1. The purpose of this study was to demonstrate that ketamine anesthesia (100 mg/kg) induces tongue protrusions (P) in addition to retrusions (R) and swallows (S) in adult rats. 2. These linguo-pharyngeal events occur alone or combined in various sequential patterns. 3. The SPR sequence is not the predominant pattern in all preparations suggesting profound disruption of physiological linkages by ketamine. 4. Haloperidol administration suppresses these events for 1-120 min depending on the dose (0.75-2.5 mg/kg). 5. Swallows are the least vulnerable to haloperidol. 6. This and previous findings provide further evidence that ketamine induced linguo-pharyngeal activity can serve as a model for acute or tardive dyskinesia better than stereotypies.     

Isolation and sequencing of cDNA clones encoding Drosophila chromosomal protein D1. A repeating motif in proteins which recognize at DNA

Drosophila melanogaster D1 is a satellite DNA-associated protein which preferentially binds DNA sequences containing runs of AT base pairs. Clones encoding this polypeptide have been isolated from a lambda gt11 cDNA library by immunological screening with a D1 antiserum. The deduced sequence of the D1 polypeptide is 355 amino acids long and contains 10 copies of a repeating motif consisting of a glycine-arginine-proline (GRP) tripeptide located within a cluster of basic amino acids. Three copies of a similar motif have previously been observed in a mammalian satellite DNA-binding protein, high mobility group protein I (Lund, T., Dahl, K. H., Mork, E., Holtlund, J., and Laland, S. G. (1987) Biochem. Biophys. Res. Commun. 146, 725-730), suggesting that this motif may be a general feature of proteins which bind AT-rich satellite DNA and perhaps other AT-containing DNA as well.     

IMPRINTING EFFECTS OF THREE AMINO ACIDS (ALANINE,LYSINE AND GLYCINE) AND THEIR OLIGOPEPTIDES INTETRAHYMENA PYRIFORMIS. DATA FROM THE HORMONE AND HORMONE RECEPTOR EVOLUTION

Hormonal imprinting takes place at the first encounter of the hormone and receptor, and results in a changed binding capacity and reaction of the cell and its progeny generations. The imprinting effect of three amino acids and their oligopeptides is studied using fluorescent-labelled peptides. Glycine and lysine could provoke positive imprinting (increased binding in the progeny generations) for their own peptides, but alanine could not. Mostly positive imprinting was provoked by glycine and lysine peptides for their own peptides of different chain length. The optimal chain length provoking self-imprinting was four for glycine, two for lysine and three for alanine. Except in this case, alanine was neutral or provoked mostly negative imprinting. After reaching the optimal chain length, there is a decline in binding. Evolutionary conclusions are discussed.     

Induction of cytotoxic T cells to a cross-reactive epitope in the hepatitis C virus nonstructural RNA polymerase-like protein.

Cytotoxic T lymphocytes (CTL) have been found to mediate protection in vivo against certain virus infections. CTL also may play an important role in control of infection by hepatitis C virus (HCV), but no CTL epitopes have yet been defined in any HCV protein. The nonstructural protein with homology to RNA polymerase should be a relatively conserved target protein for CTL. To investigate the epitope specificity of CTL specific for this protein, we used 28 peptides from this sequence to study murine CTL. Mice were immunized with a recombinant vaccinia virus expressing the HCV nonstructural region corresponding to the flavivirus NS5 gene (RNA polymerase), and the primed spleen cells were restimulated in vitro with peptides. CTL from H-2d mice responded to a single 16-residue synthetic peptide (HCV 2422 to 2437). This relatively conserved epitope was presented by H-2d class I major histocompatibility complex (MHC) molecules to conventional CD4- CD8+ CTL but was not recognized by CTL restricted by H-2b. Moreover, exon shuffle experiments using several transfectants expressing recombinant Dd/Ld and Kd demonstrated that this peptide is seen in association with alpha 1 and alpha 2 domains of the Dd class I MHC molecule. This peptide differs from the homologous segments of this nonstructural region from three other HCV isolates by one residue each. Variant peptides with single amino acid substitutions were made to test the effect of each residue on the ability to sensitize targets. Neither substitution affected recognition. Therefore, these conservative mutations affected peptide interaction neither with the Dd class I MHC molecule nor with the T-cell receptor. Because these CTL cross-react with all four sequenced isolates of HCV in the United States and Japan, if human CTL display similar cross-reactivity, this peptide may be valuable for studies of HCV diagnosis and vaccine development. Our study provides the first evidence that CD8+ CTL can recognize an epitope from the HCV sequence in association with a class I MHC molecule.     

Iodometric measurement of lipid hydroperoxides in human plasma

Many assay techniques have been used to measure lipid hydroperoxides in plasma, including absorbance of conjugated dienes and reactivity with thiobarbituric acid. Because these measurements are not specific for lipid hydroperoxides, we modified an exisiting iodometric method to correct for interfering phenomena and to provide a more specific measurement of the lipid hydroperoxide content of plasma. To ensure reproducible extraction of hydroperoxides from the many possible forms in plasma, the plasma was treated to hydrolyze enzymatically cholesterol ester, triglycerides, and phospholipids, and the nonesterified fatty acid peroxides were then extracted with ethyl acetate. Extracted lipids were reacted with potassium iodide in acetic acid and methylene chloride, and the resulting triiodide ion (I3-) was measured spectrophotometrically. Correction for nonoxidizing chromophores was made after back-titration of the triiodide ion to iodide with sodium thiosulfate and other non-peroxide oxidants were estimated by their resistance to reduction with glutathione peroxidase. Recovery of added hydroperoxide standards provided routine validations of the procedure's efficiency. The method indicated that insignificant amounts of hydroperoxide may be in the less polar lipids, but the total amount of lipid hydroperoxide esterfied in the plasma lipids of apparently healthy humans may be as much as 4.0 +/- 1.7 microM.     

Intense photon emission induced by fracture of γ–irradiated Dy‐, Tm‐, Sm‐ and Mn‐doped CaSO4 single crystals

When an γ‐irradiated Dy‐, Tm‐, Sm‐ or Mn‐doped CaSO₄ crystal is impulsively deformed, two peaks appear in the ML intensity versus time curve, whereby the first ML peak is found in the deformation region and the second in the post‐deformation region of the crystals. In this study, intensities I_m1 and I_m2 corresponding to first and second ML peaks, respectively, increased linearly with an impact velocity v₀ of the piston used to deform the crystals, and times t_m1 and t_m2 corresponding to the first and second ML peaks, respectively, decreased with impact velocity. Total ML intensity initially increased with impact velocity and then reached a saturation value for higher values of impact velocity. ML intensity increased with increasing γ‐doses and size of crystals. Results showed that the electric field produced as a result of charging of newly‐created surfaces caused tunneling of electrons to the valence band of the hole‐trapping centres. The free holes generated moved in the valence band and their subsequent recombination with electron trapping centres released energy, thereby resulting in excitation of luminescent centres. Copyright © 2012 John Wiley & Sons, Ltd.     

Cell Budding from Normal Appearing Epithelia: A Predictor of Colorectal Cancer Metastasis?

Background: Colorectal carcinogenesis is believed to be a multi-stage process that originates with a localized adenoma, which linearly progresses to an intra-mucosal carcinoma, to an invasive lesion, and finally to metastatic cancer. This progression model is supported by tissue culture and animal model studies, but it is difficult to reconcile with several well-established observations, principally among these are that up to 25% of early stage (Stage I/II), node-negative colorectal cancer (CRC) develop distant metastasis, and that circulating CRC cells are undetectable in peripheral blood samples of up to 50% of patients with confirmed metastasis, but more than 30% of patients with no detectable metastasis exhibit such cells. The mechanism responsible for this diverse behavior is unknown, and there are no effective means to identify patients with pending, or who are at high risk for, developing metastatic CRC.Novel findings: Our previous studies of human breast and prostate cancer have shown that cancer invasion arises from the convergence of a tissue injury, the innate immune response to that injury, and the presence of tumor stem cells within tumor capsules at the site of the injury. Focal degeneration of a capsule due to age or disease attracts lymphocyte infiltration that degrades the degenerating capsules resulting in the formation of a focal disruption in the capsule, which selectively favors proliferating or “budding” of the underlying tumor stem cells. Our recent studies suggest that lymphocyte infiltration also triggers metastasis by disrupting the intercellular junctions and surface adhesion molecules within the proliferating cell buds causing their dissociation. Then, lymphocytes and tumor cells are conjoined through membrane fusion to form tumor-lymphocyte chimeras (TLCs) that allows the tumor stem cell to avail itself of the lymphocyte''s natural ability to migrate and breach cell barriers in order to intravasate and to travel to distant organs. Our most recent studies of human CRC have detected nearly identical focal capsule disruptions, lymphocyte infiltration, budding cells, and the formation of TLCs. Our studies have further shown that age- and type-matched node-positive and -negative CRC have a significantly different morphological and immunohistochemical profile and that the majority of lymphatic ducts with disseminated cells are located within the mucosa adjacent to morphologically normal appearing epithelial structures that express a stem cell-related marker.New hypothesis: Based on these findings and the growth patterns of budding cells revealed by double immunohistochemistry, we further hypothesize that metastatic spread is an early event of carcinogenesis and that budding cells overlying focal capsule disruptions represent invasion- and metastasis-initiating cells that follow one of four pathways to progress: (1) to undergo extensive in situ proliferation leading to the formation of tumor nests that subsequently invade the submucosa, (2) to migrate with associated lymphocytes functioning as “seeds” to grow in new sites, (3) to migrate and intravasate into pre-existing vascular structures by forming TLCs, or (4) to intravasate into vascular structures that are generated by the budding cells themselves. We also propose that only node-positive cases harbor stem cells with the potential for multi-lineage differentiation and unique surface markers that permit intravasation.