Cloning and antigenic expression of two genes from Chlamydia psittaci avian strain

Abstract: Genes from Chlamydia psittaci P-1041 were cloned into the Bam HI site of pUC19 and were transformed to host Escherichia coli JM109. Two recombinant plasmids that expressed protein antigens of Chlamydia were isolated. The sizes of the DNA fragments were 1350 and 1710 bp, and encoded for polypeptides of M _r 25 and 42 kilodaltons (kDa), respectively. The 25-kDa protein had cross-reactivity with antisera to ten C. psittaci strains and two C. trachomatis strains, whereas the 42-kDa protein reacted only with homologous antiserum to the C. psittaci P-1041 strain. Furthermore, in Southern hybridization analysis these two fragments as probes hybridized with DNA of ten C. psittaci strains and four C. trachomatis strains. These results indicated that the two fragments shared a DNA sequence common to the chlamydial genus.     

Hypusine, N6-(4-amino-2-hydroxybutyl)-2,6-diaminohexanoic acid,in tissue proteins of mammals

Hypusine, N⁶-(4-amino-2-hydroxybutyl)-2,6-diaminohexanoic acid was isolated from proteins of bovine brain. Its identification was performed by comparison of its behavior in amino acid analysis, paper chromatography and electrophoresis to that of the authentic compound, and by periodic acid-permanganate oxidation which split hypusine into β-alanine and lysine. Hypusine was found in proteins of various organs of rabbits.Formation of hypusine from lysine was demonstrated by the intraperitoneal injection of labeled lysine into a rat and isolation of radioactive hypusine from the animal proteins. This findings indicates a possibility that hypusine is derived from the lysine residue of proteins through attachment of the 4-amino-2-hydroxybutyl moiety to the N⁶-amino radical of lysine.     

Adjuvant Action of Capsular Polysaccharide of Klebsiella pneumoniae on Antibody Response

The sequence of histological changes in the regional lymph node and other lymphoid organs of mice injected with the capsular polysaccharide of Klebsiella pneumoniae (CPS-K) or bacterial lipopolysaccharide (LPS) was followed. Injection of CPS-K, but not LPS, induced the following characteristic histological changes in the regional lymph node. In the early stage there was a marked decrease in the number of small lymphocytes, accompanied by the appearance of scattered fragmented nuclei and infiltration of polymorphonuclear neutrophilic leukocytes, and in the late stage there was marked proliferation of macrophage-like cells and pyroninophilic cells. Histological changes in the thymus and spleen and changes in cell populations in the bone marrow and peripheral blood after CPS-K injection were essentially the same as after LPS injection. Since CPS-K has a much stronger adjuvant action on antibody response than does LPS, it is suggested that the characteristic histological changes in the regional lymph node after injection of CPS-K are closely related to its extraordinarily strong adjuvant action.     

A New Brassinolide-related Steroid in the Leaves of Thea sinensis

Microscopic and dynamic mechanical properties for mixed aqueous gels of agar and gelatin have been studied. The microscopic observation showed formation of micro granules in the gels under the phase-contrast visual field. The constituent was recognized as agar by metachroma tic staining using a microspectrophotometer. Dynamic moduli of the gels were measured from 0.01 to 200 Hz by phase difference and by resonance. A minimum E' value was obtained for the mixed gel at a volume fraction of agar of 0.6. E′ of all gels and E″ of mixed gels were frequency dependent above 30 Hz.     

Dystrophin in rod spherules; submembranous dense regions facing bipolar cell processes

 It is known that the retina contains the protein dystrophin in the ribbon synapse, but the ultrastructural analysis is not yet fully elucidated. Our previous study reported that dystrophin is localized under the rod cell membranes in rat retinas. In the present study, we have investigated the relationship between dystrophin-rich regions of rod cell membranes and other neuronal processes in mouse retinas with a monoclonal antibody raised against the human dystrophin C-terminus. Immunoblotting, immunofluorescence stainings, and immunoelectron microscopy were employed. Immunoblotting analysis indicated that mouse retinas possessed some of the dystrophin isoforms of approximately 260 kDa, 140 kDa, and 70 kDa molecular weight. Confocal images showed a punctate appearance in the outer plexiform layer, as previously described. Immunoelectron microscopy showed that dystrophin immunoreactive products were always observed at submembranous dense regions of the rod spherule abutting bipolar processes. These results suggest that retinal dystrophin may be closely involved in signal transmission from rods to bipolar cells. Accepted: 7 May 1997