Inactivation and sedimentation of mercury from organomercurials by Klebsiella pneumoniae

Abstract A susceptibility of 63 clinical isolates of Klebsiella pneumoniae to inorganic and organic mercuric compounds was determined. 18 of them were found to be resistant to fluorescein mercuric acetate (FMA) and merbromin (MB). Moreover, all the resistant strains inactivate the antibacterial effect of FMA. The changes in the amount of organic mercury at the time of inactivation of the drug and the structures of the end products were examined in detail with the plasmid-bearing strain JK9 and its transconjugants of Escherichia coli .
The results showed that FMA was inactivated by an intracellular enzyme produced inducively and was degraded to fluorescein (sodium salt, uranine), which led to the sedimentation of metallic mercury. The discovery of the genes conferring inducible organic mercury-inactivating enzymes determined by plasmids was the next step and their application in the recovery of metallic mercury from organomercurials is now imminent.     

A novel cell-surface antigen expressed on most leukocytes and a minor cortisone-resistant population of thymocytes in rats: characterization by monoclonal antibodies

A cell-surface antigen on rat lympho-hemopoietic cells was determined by using a monoclonal antibody, R2-1B3 (1B3). The 1B3 antibody, when tested for its reactivity with different hemopoietic cells by cytofluorography with a FACS analyzer, labeled more than 80% of lymph node, spleen, and bone marrow cells and 10-20% of thymus cells. Cytofluorographic analysis performed on purified rat T cells, B cells, macrophages, and granulocytes demonstrated that the antigen defined by 1B3 was readily detectable on all of these cell types, with the greatest expression on B cells. A minor population of thymocytes that were labeled by 1B3 appeared to be cortisone-resistant and were located mainly in the thymic medulla. These 1B3 positive thymic cells seemed to be functionally more mature than 1B3-negative thymus cells as suggested by the fact that the cytotoxic treatment of thymus cells with 1B3 antibody and complement (C) resulted in significant reduction of their responsiveness to phytomitogens and lymphokines derived from concanavalin A (con A) activated rat spleen cell cultures. Immunochemical data showed that 1B3 antibody recognized the broad ill-defined band with a molecular weight of 32K to 47K daltons as estimated by SDS-polyacrylamide gel electrophoresis. These data indicate that the 1B3 defined antigen is distinct from other, previously reported, antigens on rat lymphoid cells including leukocyte-common (L-C) and MRC OX-22 antigens, and that this 1B3 antibody is a useful reagent for analyzing the intrathymic differentiation of T cells in rats.     

Adherence of Fusobacterium necrophorum to bovine hepatic cells

Abstract The adherence of Fusobacterium necrophorum to the surface of bovine hepatic cells was investigated. Hemagglutinating strain VPI2891 adhered well to the cell membranes, whereas non-hemagglutinating strain S-45 adhered less well. The adherence of the former strain was strongly inhibited by the homologous anti-hemagglutinin serum. Immunofluorescence study revealed that the purified hemagglutinin bound to the membranes of the hepatic cells. These findings suggest that the adherence of F. necrophorum to the bovine hepatic cells is mediated by the bacterial hemagglutinin and has pathogenic importance in bovine necrobacillosis.     

Separation of the Effects of Photoperiod and Hormones on Sex Expression in Cucumber

The effects of photoperiod on the sex expression of cucumberflowers were examined in relation to the endogenous GA and ethyleneproduction with short day (SD)- and long day (LD)-sensitivecultivars under controlled environmental conditions. Growth of plants was greatly reduced under LD in both typesof cultivars. Reflecting this, GA activity was greater and ethyleneevolution less in plants grown under SD than in those underLD. However, the number of pistillate flowers increased underSD and LD in SD- and LD-sensitive cultivar, respectively, indicatingthat a change in sex expression did not coincide with hormonalchanges in the SD-sensitive cultivar. Thus, the effect of photoperiodon the sex expression was found to be separate, at least inpart, from the effect of GA or ethylene in cucumber. (Received September 16, 1982; Accepted December 7, 1982)     

Carbon-cycling changes during regeneration of a decinduous broadleaf forest after clear-cutting II. Aboveground net production

Growth and death rates of aboveground plant parts were measured in a mature forest and four different-aged deciduous broadleaf forests regeneratede after clear-cutting, with special reference to rates for woody parts (stems and branches) of different diameters (ø) in rerms of the pipe model theory (Shinozaki et al., 1964). The total biomass increment of woody parts of trees higher than 1.3 m varied within a range of 2.1-4.6 ton ha^?1 yr^?1, the increase beingdue largely to the growth of canopy trees exposed to direct sunlight. Biomass increments of small (ø<1 cm) and medium (1≤ø<5 cm) woody parts were negligibly small except in the youngest forest, and changes in aboveground woody biomass with forest age after clear-cutting mainly resulted from accumulation of large (5 cm<ø) woody parts of canopy trees. Biomass loss of trees due to death and grazing increased with forest age from 4.0 to 8.3 ton ha^?1 yr^?1. Recovery of leaf and small wood falls was observed at the early stage of regeneration, while large wood falls increased during regeneration. Flower and fruit fall was markedly higher in the mature forest than in the other four forest types. Mortality of woody parts became higher with forest age and was 20, 5.0 and 0.46% yr^?1 for small, medium and large parts, respectively, at the mature stage. Aboveground net production of the forest was in therange 7.6-13.3 ton ha^?1 yr^?1 with the undergrowth vegetation lower than 1.3 m being 0.4-1.4 ton ha^?1 yr^?1. Production recovered rapidly at an early stage of regeneration and was highest in mature forest.     

Comparative study of the sugar chains of gamma-glutamyltranspeptidases purified from human hepatocellular carcinoma and from human liver

The sugar chains of gamma-glutamyltranspeptidases, purified from human hepatoma and from normal human liver, were released quantitatively as oligosaccharides by hydrazinolysis. Comparative study of their structures revealed that the following structural alterations are induced by hepatocyte carcinogenesis: 1) high mannose type sugar chains are detected in the hepatoma enzyme but not in the normal liver enzyme; 2) abnormal biantennary sugar chains containing C-2,4 outer chain branches newly appeared; 3) the total amounts of tri- and tetraantennary sugar chains containing C-2,6 outer chain branches increased up to three times.     

Carbohydrate structures of nonspecific cross-reacting antigen-2, a glycoprotein purified from meconium as an antigen cross-reacting with anticarcinoembryonic antigen antibody. Occurrence of complex-type sugar chains with the Gal beta 1----3GlcNAc beta 1----3Gal beta 1----4GlcNAc beta 1----outer chains

Nonspecific cross-reacting antigen-2 (NCA-2) is a glycoprotein purified from meconium as a closely correlated entity with carcinoembryonic antigen (CEA). As in the case of CEA, only asparagine-linked sugar chains are included in NCA-2. In order to elucidate the structural characteristics of the sugar chains of NCA-2, they were quantitatively released from the polypeptide backbone by hydrazinolysis and reduced with NaB3H4 after N-acetylation. The radioactive oligosaccharides were fractionated by paper electrophoresis, serial chromatography on immobilized lectin columns, and Bio-Gel P-4 (under 400 mesh) column chromatography. Structures of the oligosaccharides were estimated from the data of the binding specificities of immobilized lectin columns and the effective size of each oligosaccharide determined by passing through a Bio-Gel P-4 column and were then confirmed by endo-beta-galactosidase digestion, sequential digestion with exoglycosidases with different aglycon specificities, and methylation analysis. NCA-2 contains a similar number (27 mol) of sugar chains in one molecule compared with CEA (24-26 mol). However, all sugar chains of NCA-2 were complex-type in contrast to CEA, approximately 8% of the sugar chains of which were high mannose-type (Yamashita, K., Totani, K., Kuroki, M., Matsuoka, Y., Ueda, I., and Kobata, A. (1987) Cancer Res. 47, 3451-3459). About 80% of the oligosaccharides from NCA-2 contain bisecting N-acetylglucosamine residues, and the percent molar ratio of mono-, bi, tri, and tetraantennary oligosaccharides was 2:14:57:27. (+/- Fuc alpha 1----2)Gal beta 1----4(+/- Fuc alpha 1----3)GlcNAc, (+/- Fuc alpha 1----2)Gal beta 1----3(+/- Fuc alpha 1----4)GlcNAc, (+/- Fuc alpha 1----2)Gal beta 1----4(+/- Fuc alpha 1----3)GlcNAc beta 1---- 3Gal beta 1----4GlcNAc, (+/- Fuc alpha 1----2)Gal beta 1----3(+/- Fuc alpha 1----4)GlcNAc beta 1---- 3Gal beta 1----4GlcNAc, and GalNAc beta 1----3Gal beta 1----3GlcNAc beta 1----3Gal beta 1----4GlcNAc were found as their outer chain moieties. Approximately 60% of the oligosaccharides from NCA-2 contain the Gal beta 1----4 or 3GlcNAc beta 1----3Gal beta 1----4GlcNAc beta 1----group in their outer chains.     

Indolepyruvate Pathway for Indole-3-Acetic Acid Biosynthesis in Bradyrhizobium elkanii

Indole-3-acetaldehyde (IAAId) was detected in the culture supernatantof Bradyrhizobium elkanii. Deuteriumlabelled L-tryptophan (Trp)was incorporated into IAAId and indole-3-acetic acid (IAA),suggesting that B. elkanii produces IAA via IAAId from Trp.In B. elkanii cell suspension, indole-3-pyruvic acid (IPyA)was converted to IAAId, and exogenously added IAAId was rapidlyconverted to IAA. Furthermore, the activity of indolepyruvatedecarboxylase (IPDC), which catalyzes the decarboxylation ofIPyA to produce IAAId and is a key enzyme for IPyA pathway,was detected in B. elkanii cell-free extract. The IPDC activitydepended on Mg²⁺ and thiamine pyrophosphate, cofactors of decarboxylation.This mounting evidence strongly suggests that IAA synthesisoccurs via IPyA pathway (Trp IPyA p IAAId IAA) in B. elkanii. (Received December 11, 1995; Accepted March 4, 1996)     

Dibromothymoquinone (DBMIB) Replaces the Function of QA at 77 K in the Isolated Photosystem II Reaction Center (D1-D2-Cytochrome b559) Complex: Difference Spectrum of the P680+(DBMIB-) State

Transient absorbance changes of the primary electron donor chlorophylla (P680) and acceptor pheophytin a (H) were measured at 77 Kby nanosecond laser spectroscopy in the D1-D2-cytochrome b₅₅₉photosystem II reaction center complex containing dibromomethylisopropylbenzoquinone (DBMIB). After the laser excitation of the reactioncenter in the presence of DBMIB, only the P680⁺-(DBMIB^-) statewas detected. P680⁺ mainly decayed with a t_1/e of 11 ms. Inthe absence of DBMIB, the excitation produced the P680⁺H^- radicalpair. The radical pair produced the triplet state (P680^T) witha t_1/e of 50 ns, and P680^T then decayed with a t_1/e of 2.1 ms.It was concluded that H_- was oxidized by DBMIB in a time rangefaster than the detecting time resolution (3.5 ns) even at 77K. The rapid oxidation of H^- by DBMIB was also confirmed bythe suppression of delayed fluorescence with a decay t_1/e of50 ns. The P680⁺(DBMIB^-)/P680(DBMIB) difference spectrum exhibiteda Q_y, band with a peak at 682 nm with a shoulder at 673 nm.The spectral shape was almost temperature insensitive between77 and 265 K. The feature of this spectrum in the wavelengthrange between 330 and 720 nm was compared with that of P680_T/P680or H^-/H at 77 K. (Received May 8, 1996; Accepted June 24, 1996)