High frequency, cell type-specific visualization of fluorescent-tagged genomic sites in interphase and mitotic cells of living Arabidopsis plants

Background  

Interphase chromosome organization and dynamics can be studied in living cells using fluorescent tagging techniques that exploit bacterial operator/repressor systems and auto-fluorescent proteins. A nuclear-localized Repressor Protein-Fluorescent Protein (RP-FP) fusion protein binds to operator repeats integrated as transgene arrays at defined locations in the genome. Under a fluorescence microscope, the tagged sites appear as bright fluorescent dots in living cells. This technique has been used successfully in plants, but is often hampered by low expression of genes encoding RP-FP fusion proteins, perhaps owing to one or more gene silencing mechanisms that are prevalent in plant cells.     

Myeloma-related disorder with leukaemic progression in a cat

A 10-year-old American Shorthair cat with nasal discharge, anorexia, and weight loss was found to have pancytopenia and hyperproteinaemia. Bone marrow aspiration revealed atypical plasma cells that totalled 50% of the nucleated bone marrow cells. The number of atypical plasma cells progressively increased in the peripheral blood during the observation period of 64 days. The cat did not respond to treatments with melphalan, chlorambucil, and prednisolone, and died 71 days after the initial presentation. Clinical, cytological, histopathological, and immunohistochemical findings in this case supported the diagnosis of myeloma-related disorder (MRD) with leukaemic progression.     

Basal area growth and mortality of Betula maximowicziana affected by crown dieback in a secondary forest in Hokkaido, northern Japan

Since the late 1990s, decline of B. maximowicziana Regel has been observed in mature secondary forests in various parts of Hokkaido, northern Japan. To develop a method of thinning for large-timber production of B. maximowicziana, we measured basal area growth and the mortality of 217 trees during a four-year period (1999–2003) in a 90-year-old secondary forest with serious tree damage. We analyzed growth and mortality in relation to the degree of crown dieback (DC), symmetric and asymmetric competition from neighbors, and initial tree size. Individual basal area growth decreased with increasing DC, with increasing symmetric (two-sided) competition, and with decreasing initial tree size. During the four-year period, 4.1% of the observed trees died. Logistic regression analysis revealed that mortality rate increased with increasing DC and with increasing symmetric competition. These results suggest that both growth and mortality rates were affected by the same factors (i.e., DC and symmetric competition). We concluded that the resource for which individuals were competing at the study site was underground, most likely water. Modeled growth and mortality rates can be used to improve the management of damaged forests. A management plan for the damaged study site is proposed.     

Fabrication of pulverized cellulosics by ultra high-pressure water jet treatment and usage in polymer nanocomposites and graft copolymerization

Cellulose powders were pulverized by an ultra high-pressure counter-collision treatment in an aqueous suspension state, and then used in composites with vinyl polymers and graft copolymerized with methyl methacrylate using ceric ion initiator. The influence of freeze-drying methods after microfibrillation of cellulose was visualized by scanning electron microscopy (SEM). The coalescence of microfibrillar structures was observed to increase easily reflecting the freeze-drying conditions. While the degree of microfibrillation was unsatisfactory for use as fillers in preparing polymer-nanocellulose composites, the situation was found to be rectified with the use of a proper kneading technique. The roles of microfibrillated cellulose in processes producing bio-nano-composites suitable for practical uses were studied through SEM observations and measurements of physical properties. The characteristics of the successive graft copolymerization were studied through examining the monomer conversion and the grafting effi- ciency. The significant improvement in the grafting became apparent in response to the counter-collision pretreatment. Dynamic viscoelastic properties of the molded sheets of the grafted products were studied to measure the effects of the graft copolymerization compared with the corresponding physically blended material and neat poly(methyl methacrylate). The grafting reaction resulted in composites with much higher heat-resisting properties than those obtained for the latter two.     

Retention behavior of size and aluminum components in handsheets prepared in rosin soap size-alum systems

Handsheets were prepared with rosin soap size and aluminum sulfate under various conditions, and the retention behavior of the rosin size and aluminum components in the handsheets was studied. Pyrolysis-gas chromatography and X-ray fluorescence analysis were used to determine the size and aluminum contents in the handsheets, respectively. When the addition level of rosin soap size varied from 0% to 4% and that of aluminum sulfate was fixed at 2%, the rosin size content increased with the increase in the size addition level, whereas aluminum and calcium contents were roughly constant. Under these conditions, handsheets prepared from fines-free pulp had aluminum contents less than those for the original beaten pulp, probably because the former pulp had a carboxyl content less than that of the latter pulp. Not only the conventional rosin retention mechanism but also mechanism proposed below must exist in the rosin soap size-alum systems. That is, some aluminum compounds originating from aluminum sulfate are adsorbed on pulp fibers immediately after the aluminum sulfate addition. These adsorbed aluminum compounds form cationic sites on pulp fibers, and free rosin acid components with anionic charges are then adsorbed onto the cationic sites of pulp fibers at the wet-end.This research was presented in part at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996     

Plasma cell myeloma producing IgG, IgM, and IgA immunoglobulins in a cow.

A diagnosis of plasma cell myeloma was made in a 6-year-old Holstein cow that showed continuous nosebleed, progressing emaciation, and hyperglobulinemia. Necropsy revealed enlargement of the caudal mesenteric lymph nodes. Lymph nodes and spleen were infiltrated by neoplastic plasma cells. Renal lymph nodes, bone marrow, and kidneys also were affected. Amyloid-like material that was negative for Congo red was present in most of the affected lymph nodes. Congo red-positive amyloid material was noted in spleen, kidneys, liver, and adrenal glands. Neoplastic plasma cells exhibited immunohistochemical reactions for lambda-light chain and 3 classes of heavy chain but not for kappa-light chain. Nonamyloid deposits were labeled with antisera against lambda-light chain and heavy chains. Plasmacytoid cells, which stained positively for IgG, IgM, or IgA, were intermingled in all lesions. Production of 3 types of immunoglobulins may be caused by heavy-chain class switching, constantly occurring in certain proportions.