35-10-9.pdf

The microtubule organizational changes in the isolated generative cells of Allemanda schottii were followed using immunofluorescence and confocal laser scanning microscopy. Due to the improved resolution and the lack of out-of-focus flares, the microtubule cytoskeleton of the generative cells could be visualized more clearly than using conventional epifluorescence systems. Immediately after isolation the microtubule cytoskeleton of the generative cells was cage-like composed of longitudinally oriented microtubule bundles. Later, some bundles began to depolymerize and at the same time some smaller bundles appearred. The smaller bundles unlike the longitudinal bundles crisscrossed throughout the cell. Later still, the cells became spherical. Both the longitudinal and the smaller bundles disappearred. At the same time some of the microtubules began to aggregate around the nucleus. These perinuclear microtubules were apparently not very stable, because soon afterwards,they started to disintegrate. By the time the cells became completely spherical,the cytoplasm became filled with diffuse fluorescence indicating that the tubulin was no longer existing in a polymerized form but in a monomeric form inside the cell. After the fuberlin had completely depolymerized the microtubules started to reform. The sequence of events leading to the reformation of the microtubule cytoskeleton in the spherical cells was as follow: A few nucleating centres began to form first. Then the nucleating centres gave rise to microtubule bundles. The bundles extended and aggregated to form a reticulate network. This cytoskeletal network appearred stable and well organized. It also had a lot of microtubule-bundle junctions. The network persisted after Triton X-l00 extraction.     

Lessons from genetically engineered animal models. XII. IL-10-deficient (IL-10(-/-) mice and intestinal inflammation

Interleukin (IL)-10(-/-) mice spontaneously develop intestinal inflammation characterized by discontinuous transmural lesions affecting the small and large intestine and by dysregulated production of proinflammatory cytokines. The uncontrolled generation of IFN-gamma-producing CD4(+) T cells (Th1 type) has been shown to play a causal role in the development of enterocolitis affecting these mutants. This article discusses studies of IL-10(-/-) mice that have investigated the role of enteric organisms in triggering intestinal disease, the mediators responsible for initiating and maintaining intestinal disease, the role IL-10 plays in the generation and/or function of regulatory cells, and the results of IL-10 therapy in experimental animal models of inflammatory bowel disease (IBD) and human patients with IBD.     

A lac promoter with a changed distance between -10 and -35 regions.

A lac promotor mutant was constructed by filling in the protruding ends of the HpaII site located within the lac promotor. The mutation, named M42, is a two base pair insertion that changes the distance between the -10 and -35 regions from 18 to 20 residues. The activity of the mutant promotor measured in vivo is 15% of the wild-type promotor. The M42 promotor is sensitive to the catabolite repression in the manner similar to that of the wild type. Sequences of several deletions within the lac promotor are also given.     

Measurement of 10(-7) to 10(-12) mol of potassium by stimulation of pyruvate kinase.

A method for measuring potassium is described which is based on the requirement of pyruvate kinase for this cation. Activity of this enzyme is linear with respect to potassium concentration between 10 and 100 μm. The rate of pyruvate formation is measured with lactic dehydrogenase and NADH in a coupled assay. Other common cations do not interfere at concentrations likely to be present. With a variety of plant extracts, potassium concentrations obtained with the assay were in agreement with those obtained using a flame photometer. For measuring smaller amounts of potassium the reaction is carried out in a small volume and the NAD⁺ produced is converted to a highly fluorescent product or is amplified by enzymatic cycling. These procedures have been tested extensively only on plant material, but the assay should be generally applicable.     

Isolation and characterization of bacteriophage FC3-10 from Klebsiella spp.

FC3-10 is a Klebsiella spp. specific bacteriophage isolated on a rough mutant (strain KT707, chemotype Rd) of K. pneumoniae C3. The bacteriophage receptor for this phage was shown to be the low-molecular mass lipopolysaccharide (LPS) fraction (LPS-core oligosaccharides), specifically the heptose content of the LPS inner-core. This is the first phage isolated on Klebsiella, the receptor for which is the LPS-core. This phage was unable to plate on Salmonella typhimurium LPS mutants with chemotypes Rd2 or Re showing incomplete or no heptose content on their LPS-core, respectively. Spontaneous phage-resistant mutants from different Klebsiella strains were deep-rough LPS mutants or encapsulated revertants from unencapsulated mutant strains.     

Dream content of 10- to 11-year-old preadolescent boys and girls.

This study examines the content of dreams of 10 to 11-year-old boys (n = 80) and girls (n = 102) gathered using the Most Recent Dream Method (Hartmann, Elkin, & Garg, 1991) and analyzed through the Hall and Van de Castle Method (1966; Domhoff, 1996). The study compares the dreams of the Italian sample with those of a normative adult sample and other research on the dreams of preadolescents of various countries (United States, Spain, and Switzerland). In the main it confirms the results of such preadolescent dream analysis research (Avila-White, Schneider, & Domhoff, 1999; Oberst, Charles, & Chamarro, 2005; Saline, 1999; Strauch & Lederbogen, 1999), highlighting in particular the importance of aggressive physical interaction in the participants under study. The data that emerge from dream analysis may be compared with the results of research into problems of aggression and transgression in boys and girls at this age (Achenbach & Rescorla, 2007). Dream analysis may represent a significant contribution to the study of preadolescence, allowing the characteristics and prevailing themes of preadolescents to be compared with those of participants from other age ranges. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facile transition between 3(10)- and alpha-helix: structures of 8-, 9-, and 10-residue peptides containing the -(Leu-Aib-Ala)2-Phe-Aib- fragment.

A structural transition from a 3(10)-helix to an alpha-helix has been characterized at high resolution for an octapeptide segment located in 3 different sequences. Three synthetic peptides, decapeptide (A) Boc-Aib-Trp-(Leu-Aib-Ala)2-Phe-Aib-OMe, nonapeptide (B) Boc-Trp-(Leu-Aib-Ala)2-Phe-Aib-OMe, and octapeptide (C) Boc-(Leu-Aib-Ala)2-Phe-Aib-OMe, are completely helical in their respective crystals. At 0.9 A resolution, R factors for A, B, and C are 8.3%, 5.4%, and 7.3%, respectively. The octapeptide and nonapeptide form ideal 3(10)-helices with average torsional angles phi(N-C alpha) and psi(C alpha-C') of -57 degrees, -26 degrees C and -60 degrees, -27 degrees for B. The 10-residue peptide (A) begins as a 3(10)-helix and abruptly changes to an alpha-helix at carbonyl O(3), which is the acceptor for both a 4-->1 hydrogen bond with N(6)H and a 5-->1 hydrogen with N(7)H, even though the last 8 residues have the same sequence in all 3 peptides. The average phi, psi angles in the decapeptide are -58 degrees, -28 degrees for residues 1-3 and -63 degrees, -41 degrees for residues 4-10. The packing of helices in the crystals does not provide any obvious reason for the transition in helix type. Fourier transform infrared studies in the solid state also provide evidence for a 3(10)- to alpha-helix transition with the amide I band appearing at 1,656-1,657 cm-1 in the 9- and 10-residue peptides, whereas in shorter sequences the band is observed at 1,667 cm-1.     

Inhibition of IFN-gamma-inducible protein-10 abrogates colitis in IL-10-/- mice

A deficiency in understanding the steps responsible for colitis is the lack of comprehension for the role chemokines play in mucosal inflammation. IFN-gamma-inducible protein-10 (IP-10) and CXCR3 are highly expressed at sites of colitis. Our findings show that IP-10 significantly contributes to the development of Th1 and inflammatory responses. Specifically, IP-10 inhibition in IL-10(-/-) mice attenuates the associated increases in serum and/or local amyloid A, IL-2, IL-6, TNF-alpha, IFN-gamma, IL-1alpha, and IL-1beta with colitis as compared with IL-10(-/-) mice that develop colitis similar to human Crohn's disease. Correspondingly, the rate or intensity of inflammation in IL-10(-/-) mice treated with anti-IP-10 Abs showed improved scoring of inflammation, compared with control IL-10(-/-) mice. This study provides important and novel information regarding IP-10 as a target for the treatment of colitis.     

Physical Analysis of Tn10- and Is10-Promoted Transpositions and Rearrangements

We have investigated by Southern blot hybridization the rate of IS10 transposition and other Tn10/IS10-promoted rearrangements in Escherichia coli and Salmonella strains bearing single chromosomal insertions of Tn10 or a related Tn10 derivative. We present evidence for three primary conclusions. First, the rate of IS10 transposition is approximately 10(-4) per cell per bacterial generation when overnight cultures are grown and plated on minimal media and is at least ten times more frequent than any other Tn10/IS10-promoted DNA alteration. Second, all of the chromosomal rearrangements observed can be accounted for by two previously characterized Tn10-promoted rearrangements: deletion/inversions and deletions. Together these rearrangements occur at about 10% the rate of IS10 transposition. Third, the data suggest that intramolecular Tn10-promoted rearrangements preferentially use nearby target sites, while the target sites for IS10 transposition events are scattered randomly around the chromosome.     

Synthesis of 10- and 9-membered dilactams derived from aspartic and glutamic acids.

9- and 10-membered bridged dipeptides derived from L-aspartic acid and L- or D-glutamic acid were synthesized using aminoacyl incorporation reaction. Key intermediates containing internal pyroglutamyl moiety were prepared via side chain to backbone cyclization of related protected dipeptide derivatives of glutamic acid.     

Two-dimensional NMR studies on 1-10 fragment of adrenocorticotropic hormone.

Various two-dimensional NMR techniques have been used to obtain complete resonance assignments of the protons in the 1-10 fragment of adrenocorticotropic hormone (ACTH). 1H-1H coupling constants among the backbone protons and the chemical shift values measured in aqueous and in dimethyl sulphoxide solutions indicated preference for extended but different conformations in the two solvents.