Purification of a fibrolast-inhibitory factor from Actinobacillus actinomycetemcomitans Y4

Abstract A factor showing inhibitory activity against human gingival fibrolasts was extracted from the cytosol fraction of Actinobacillus actinomycetemcomitans Y4. The activity markedly inhibited the proliferation of human gingival fibrolasts, but had no effect on cell viability or gross morphology. No such activity was found in cytosol fractions from either Porphyromonas gingivalis 381 or Escherichia coli HB101. The extract from A. actinomycetemcomitans Y4 was then purified by anion-exchange chromatography, hydroxyapatite chromatography and gel-filtration chromatography to give a single band on SDS-PAGE with an apparent molecular mass of 65 kDa. The purification ratio was 183-fold with a recovery rate of 5% compared with the crude extract (starting material) when the activity was assessed by direct cell counts.     

Bovine Diarrhea Virus

Five strains of bovine diarrhea virus were isolated from Japanese cattle using bovine tissue cultures. These are the first isolations of this virus from Japanese cattle to be reported. Of importance is the finding that the new isolates, which are non-cytopathogenic, induce an exaltation of Newcastle disease virus in bovine testicular cell culture. This finding has provided a laboratory tool whereby the assay of the virus and its neutralizing antibody can readily be performed.     

Possible existence of ion pairs at the mouths of ion channels

An electrostatic calculation suggests that when an ion is bound near the mouth of a channel penetrating a low-dielectric membrane, a counter ion may form an ion pair with this ion. The tendency towards ion-pair formation is remarkably enhanced at channel mouths by forces (image forces) arising from the charges induced on the boundaries between different dielectrics. The binding constant for the formation of ion-pairs of monovalent ions is estimated under the assumption that local interactions between the counter ion and the channel wall are negligibly small. It is of the order of 1–10 molal^?1 or more for the binding of a Cl^? (F^?) counter ion to an $\text{Na}{}^{\mathrm{+}}$ ($\text{Li}{}^{\mathrm{+}}$) ion if appropriate conditions are fulfilled. The binding constant depends on the position of the binding site, the dimensions and geometries of the channel and channel mouth, and the state of ion loading of the channel, as well as the ionic species. The present results also indicate that when cation (anion) channels have anionic (cationic) groups as integrant parts of their channel walls, interactions between these charged groups and permeant ions are markedly enhanced by the image forces.     

New Plasmid-Mediated Phosphorylation of Gentamicin C in Staphylococcus aureus

A clinical isolate of Staphylococcus aureus resistant to gentamicin, kanamycin and 3′,4′-dideoxykanamycin B contained two enzymes capable of inactivating gentamicin, i.e., an aminoglycoside 2″-phosphotransferase and aminoglycoside acetyltransferase.     

Lobeline production by hairy root culture of Lobelia inflata L.

Hairy roots were obtained following inoculation of the stems of Lobelia inflata L. with Agrobacterium rhizogenes strain ATCC 15834. These hairy roots contained agropine and mannopine. In addition, lobeline was detected by HPLC and confirmed by mass spectrometry. Various media were tested for the growth of hairy roots as well as for the content of lobeline in hairy roots. The growth rate of hairy roots cultured in Nitsch and Nitsch's medium was approximately one third of those cultured in other media. The lobeline content of hairy roots (18–54 g/g dry weight) cultured in these media was the same order of magnitude compared with that of roots of L. inflata (24 g/g dry weight) cultivated in pots. The hairy roots cultured in Nitsch and Nitsch's medium were morphologically different from those cultured in other media.Abbreviations MS medium Murashige and Skoog's medium - 1/2 MS medium one-half strength of the standard Murashige and Skoog's medium - B5 medium Gamborg's B5 medium - NN medium Nitsch and Nitsch's medium - FW fresh weight - DW dry weight     

Nudeotide Pools and Purine Metabolism in Tissue Cultures of Wild-Type Datura innoxia and Adenine-Requiring Auxotroph

Cells of the auxotrophic mutant, Ad1, of Datura innoxia requiredadenine, adenosine, or inosine for their growth on solid agarmedium which contained Murashige-Skoog salts, 2,4-dichloro-phenoxyaceticacid, and sucrose. Thirteen purine and pyrimidine nucleotidesin extracts of wild-type and Ad1 cells were separated and quantifiedby HPLC. Levels of ADP-glucose and UMP were significantly higherin Ad1 than in wild-type cells, but those of other nucleotideswas found when Ad1 cells were transferred to fresh medium withoutadenine. The rate of the biosynthesis de novo of purines, asestimated from the rate of incorporation of ¹⁴C from [2-¹⁴C]-glycine and [¹⁴C]formate into adenine nucleotides, was reducedin Ad1 cells to 21 and 13% of the wild-type rate, respectively.The activities involved in the salvage of adenine and adenosinein Ad1 cells were similar to those in wild-type cells. Ad1 cellshad the capability to convert adenine to guanine nucleotidesand guanine to adenine nucleotides. ¹ Part 27 of the series, "Metabolic Regulation in Plant CellCulture". (Received March 7, 1988; Accepted August 3, 1988)     

Evidence for the location of foreign genes in three different chromosomes in a plant obtained from direct DNA transfer

Tobacco mesophyll protoplasts were treated with plasmids, pCT2 (17.1 kbp) or pCT2T3 (18.3 kbp), which contained a chimeric aminoglycoside phosphotransferase II (APH(3′)II) gene and an intact nopaline synthase gene. Expression of two marker enzymes, APH(3′)II and nopaline synthase, were analyzed in transformed plants. Four out of 16 transformants obtained by pCT2T3 possessed both enzymes. Upon self-pollination, the progeny of one of transformants (T2) segregated to 153∶4 in terms of resistant and susceptible character to kanamycin, suggesting insertion of foreign genes into three independent chromosomes. The kanamycin resistant character in the rest of transformants showed 3∶1 segregation. DNA blot analysis of the T2 transformant and progenies indicated the presence of two marker genes.     

Chromatin diminution and chromosome elimination in four Japanese hagfish species

Cytogenetic examination of four Japanese hagfish species belonging to the order Myxinida (Eptatretus okinoseanus, E. burgeri. Paramyxine atami, and Myxine garmani) revealed differences in chromosome number between germ cells (spermatocytes and spermatogonia) and somatic cells (liver, blood, gill, and kidney). The differences in chromosome number between spermatogonia (54, 52, 48, and 16) and somatic cells (34, 36, 34, and 14) were 20, 16, 14, and 2 in E. okinoseanus, E. burgeri, P. atami, and M. garmani, respectively. The amount of DNA in a somatic cell (2C) relative to that in a germ cell (2C) averaged 54.6% (E. okinoseanus type A), 44.9% (E. okinoseanus type B), 79.1% (E. burgeri), 60.0% (P. atami), and 70.2% (M. garmani). These results clearly indicate that chromosome elimination takes place during early cleavage in the four hagfish species of Myxinida living in Japanese waters, except in the ancestral germline cells. C-banding of metaphase chromosome preparations of germline and somatic cells from each hagfish species revealed that the C-band-positive chromatin in the ancestral somatic cells had been almost completely eliminated. Three patterns of elimination of this chromatin are discussed.     

Altered localization of antigen recognized by proteinuriainducing monoclonal antibody in experimental nephrosis

Change in the localization of the antigen recognized by the proteinuria-inducing monoclonal antibody (MA) 5-1-6 in experimental nephrosis was studied by indirect and biotin-avidin immunofluorescence, and immunoperoxidase at light and electron microscopical levels. The proteinuric state was induced by the administration of the aminonucleoside of puromycin (PAN) or adriamycin. The antigen decreased in quantity and/or its distribution changed with an increase in the amount of protein excreted in both experimental models. Recovery from the alterations observed during the development and proteinuria appeared to occur when PAN-induced proteinuria subsided. This antigenic molecule may thus be essential for maintaining the normal permselectivity of glomerular capillary walls.