First Application of Mass Measurements with the Rare-RI Ring Reveals the Solar r-Process Abundance Trend at A=122 and A=123.

The Rare-RI Ring (R3) is a recently commissioned cyclotronlike storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF-^{127}Sn, ^{126}In, ^{125}Cd, ^{124}Ag, ^{123}Pd-were injected in R3. Masses of ^{126}In, ^{125}Cd, and ^{123}Pd were measured whereby the mass uncertainty of ^{123}Pd was improved. This is the first reported measurement with a new storage ring mass spectrometry technique realized at a heavy-ion cyclotron and employing individual injection of the preidentified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new ^{123}Pd result on the solar r-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction Y_{e}. It is found that the neutron capture cross section on ^{123}Pd increases by a factor of 2.2 and ß-delayed neutron emission probability, P_{1 n}, of ^{123}Rh increases by 14%. The neutron capture cross section on ^{122}Pd decreases by a factor of 2.6 leading to pileup of material at A=122, thus reproducing the trend of the solar r-process abundances. The trend of the two-neutron separation energies (S_{2n}) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S_{2n} value at N=77. Such large increase of the S_{2n} values before N=82 was proposed as an alternative to the quenching of the N=82 shell gap to reproduce r-process abundances in the mass region of A=112-124.

Copper-resistant halophilic bacterium isolated from the polluted Maruit Lake, Egypt.

AIMS: To isolate and characterize copper-resistant halophilic bacteria from the polluted Maruit Lake, Egypt and identify the role of plasmids in toxic metal resistance. METHODS AND RESULTS: We isolated strain MA2, showing high copper resistance up to the 1.5 mmol l(-1) concentration; it was also resistant to other metals such as nickel, cobalt and zinc and a group of antibiotics. Partial 16S rRNA analysis revealed that strain MA2 belonged to the genus Halomonas. Copper uptake, measured by atomic absorption spectrophotometery, was higher in the absence of NaCl than in the presence of 0.5-1.0 mol l(-1) NaCl during 5-15 min of incubation. Cell fractionation and electron microscopic observation clarified that most of the copper accumulated in the outer membrane and periplasmic fractions of the cells. Plasmid screening yielded two plasmids: pMA21 (11 kb) and pMA22 (5 kb). Plasmid curing resulted in a strain that lost both the plasmids and was sensitive to cobalt and chromate but not copper, nickel and zinc. This cured strain also showed weak growth in the presence of 0.5-1.0 mol l(-1) NaCl. Partial sequencing of both plasmids led to the identification of different toxic metals transporters but copper transporters were not identified. CONCLUSIONS: The highest cell viability was found in the presence of 1.0 mol l(-1) NaCl at different copper concentrations, and copper uptake was optimal in the absence of NaCl. Plasmid pMA21 encoded chromate, cobalt, zinc and cadmium transporters, whereas pMA22 encoded specific zinc and RND (resistance, nodulation, cell division) efflux transporters as well as different kinds of metabolic enzymes. Copper resistance was mainly incorporated in the chromosome. SIGNIFICANCE AND IMPACT OF THE STUDY: Strain MA2 is a fast and efficient tool for copper bioremediation and the isolated plasmids show significant characteristics of both toxic metal and antibiotic resistance.

Maximizing T c by tuning nematicity and magnetism in FeSe1-x S x superconductors.

A fundamental issue concerning iron-based superconductivity is the roles of electronic nematicity and magnetism in realising high transition temperature (T c). To address this issue, FeSe is a key material, as it exhibits a unique pressure phase diagram involving non-magnetic nematic and pressure-induced antiferromagnetic ordered phases. However, as these two phases in FeSe have considerable overlap, how each order affects superconductivity remains perplexing. Here we construct the three-dimensional electronic phase diagram, temperature (T) against pressure (P) and isovalent S-substitution (x), for FeSe1-x S x . By simultaneously tuning chemical and physical pressures, against which the chalcogen height shows a contrasting variation, we achieve a complete separation of nematic and antiferromagnetic phases. In between, an extended non-magnetic tetragonal phase emerges, where T c shows a striking enhancement. The completed phase diagram uncovers that high-T c superconductivity lies near both ends of the dome-shaped antiferromagnetic phase, whereas T c remains low near the nematic critical point.

In vivo radiolocalization of antiosteogenic sarcoma monoclonal antibodies in osteogenic sarcoma xenografts.

Monoclonal antibodies Ost6 and Ost7 (mouse Immunoglobulin G1) to human osteogenic sarcoma were isolated from ascitic fluid and labeled with radioiodine. After injection into athymic nu/nu mice with s.c. xenografts of human osteogenic sarcoma, the uptake of radioactivity in tumors, visceral organs, and blood was determined. Five days after injection, Ost6 and Ost7 showed preferential accumulation in tumors (tumor:blood ratio, 4.3). Furthermore, with testicular and bladder tumors, both unreactive with Ost7, there was no localization of radiolabeled Ost7 in xenograft growths. When Ost7 was labeled with 131I, its accumulation into human osteogenic sarcoma could be clearly visualized by whole-body gamma-scintigraphy without computer-assisted data processing.

Analysis of antigenic expression by primary and autologous metastatic human sarcomas using murine monoclonal antibodies.

The efficacy of monoclonal antibody therapy depends in part on the expression of the relevant tumor-associated antigens by both primary tumors and their metastases. Antigen expression by paired primary and autologous metastases from surgically excised osteogenic and soft-tissue sarcomas from 15 patients was studied using a panel of murine hybridoma monoclonal antibodies and indirect immunoperoxidase staining of formalin-fixed tissue sections. The panel included three antibodies (B3619, 17-9H3, OST6) recognizing sarcoma-associated antigens and an antibody recognizing an HLA-DR framework determinant (OKla1). In most cases, antibody binding to both primary and metastatic tumors was observed. However, marked heterogeneity of binding intensity between primary and metastatic tumors and of cells expressing antigens within tumors was noted. This occurred even though primary and metastatic tumors demonstrated homogeneous histology and cellular morphology. Differences were noted among patients as well as among metastases taken from an individual. A significant number of both primary and metastatic tumors contained cells that did not bind a particular antibody even in the presence of other cells that demonstrated significant antibody binding. Thus, strategies for single monoclonal antibody therapy may be limited by heterogeneity of intertumor and intratumor antigenic expression.

Detection of human osteosarcoma-associated antigen(s) by monoclonal antibodies.

Hybrid cell lines have been derived from a fusion between mouse myeloma cells, NS1, and spleen cells from mice immunized with freshly resected osteosarcoma cells from an untreated patient. Of the 276 hybrids obtained, five secreted antibodies which bound to osteosarcoma tissues but not to autologous skin fibroblasts. The antibodies from three of these five hybrids, OST6, OST7, and OST15, reacted with all of five osteosarcoma tissues and with one chondrosarcoma tissue but not with other malignant or benign tumors. Tests of various normal tissues were negative, except for weak binding to a subpopulation of chondrocytes in articular cartilage. The reciprocal binding inhibition test showed that OST6, OST7, and OST15 antibodies were directed against different antigenic determinants.

Control of membrane potential by external H+ concentration in Bacillus subtilis as determined by an ion-selective electrode.

The membrane potential of intact bacteria was monitored by measuring the tetraphenylphosphonium ion distribution across the membrane using poly--(vinyl chloride) matrix-type electrode selective to tetraphenylphosphonimum ion. It was found that the tetraphenylphosphonium ion was not countertransported against H+ movement. The membrane potential of Bacillus subtilis was estimated to be 80-120 mV inside-negative at external pH 7. The effect of the external pH on the membrane potential was studied. It varied from 30 to 40 mV/decade change in the external [H+] in the pH region of greater than 6.5, increasing pH making it more inside-negative. The addition of carbonyl cyanide m-chlorophenylhydrazone depolarized the membrane, and the membrane potential approached the H+ equilibrium potential. The addition of N,N'-dicyclohexylcarbodiimide did not abolish the pH dependence of the membrane potential. Increasing the external [K+] did not affect the pH dependence. CN- partially depolarized the membrane. A parallel conductance model for membrane potential could explain the results qualitatively.

Involvement of CD11b/CD18 in enhanced neutrophil adhesion by Fc gamma receptor stimulation.

Neutrophils showed a rapid and transient adhesion to immunoglobulin G (IgG)-coated plates compared with their adhesion to bovine serum albumin (BSA)-coated plates: the adhesion reached a peak after 15 min of incubation and then gradually returned to almost the basal state in 60 min. The addition of monomeric IgG or anti-Fc gamma RII monoclonal antibody (mAb) (IV.3) suppressed the increase in adhesion, whereas anti-Fc gamma RIII mAb (3G8) was hardly effective, indicating that the interaction of Fc gamma R, especially Fc gamma RII, with coated IgG is involved in the process. Adhesion was also blocked by cytochalasin B, suggesting that functional actin filament structures are crucial. Protein kinase inhibitors, erbstatin and genistein, inhibited the adhesion in a dose-dependent manner. The adhesion was inhibited by anti-CD11b (M1/70) and anti-CD18 (MHM23, TS1/18) mAbs. Moreover, neutrophils from a patient with complete leukocyte adhesion deficiency syndrome did not show increased adhesion to IgG-coated plates. The adhesion of neutrophils to fibrinogen- and BSA-coated plates was also increased when Fc gamma R was stimulated in the fluid phase with soluble aggregated IgG, which was also inhibited by anti-CD11b mAb. Stimulation of neutrophil Fc gamma R with soluble aggregated IgG enhanced the expression of CD11b in concert with the enhanced adhesion. These data collectively suggest that stimulation via Fc gamma R evokes a tyrosine kinase-dependent and actin filament-dependent intracellular signal that enhances the specific and nonspecific adhesive activity of neutrophils, presumably through the activation of CD11b/CD18.

Heat-labile, complement-like factor(s) of animal sera prevent(s) HIV-1 infectivity in vitro.

We studied inactivation of HIV-1 by fresh sera of animals. We found that while fresh sera of humans and chimpanzees (among others) did not have antiviral activity, fresh sera of several other mammals, especially those of rodents and felines, showed a dose-dependent viral-inactivating property against cell-free HIV-1; these sera were also capable of inactivating virus preadsorbed to cells, similar to neutralizing antibody. The activity was destroyed by heating to 56 degrees C, required Ca2+ but no antiviral antibody, and therefore apparently involves the classical complement pathway. The activity could not be ascribed to any single fraction of sera separated on a size exclusion HPLC column. Mouse serum (the only one tested) also inactivated HIV-2. The data are consistent with classical C-mediated pathway inactivation of HIV-1 and HIV-2 by animal sera and is the first report of any "complement-like" antilentiviral serum factor. Elucidation of this mechanism may aid in understanding the lack of activity of human serum against HIV-1 and may prove useful in combined interventive strategies against HIV-1.

Distinct aggregation of beta- and gamma-chains of the high-affinity IgE receptor on cross-linking.

The high-affinity IgE receptor (FcepsilonRI) on mast cells and basophils consists of a ligand-binding alpha-chain and two kinds of signaling chains, a beta-chain and disulfide-linked homodimeric gamma-chains. Crosslinking by multivalent antigen results in the aggregation of the bound IgE/alpha-chain complexes at the cell surface, triggering cell activation, and subsequent internalization through coated pits. However, the precise topographical alterations of the signaling beta- and gamma-chains during stimulation remain unclarified despite their importance in ligand binding/signaling coupling. Here we describe the dynamics of FcepsilonRI subunit distribution in rat basophilic leukemia cells during stimulation as revealed by immunofluorescence and immunogold electron microscopy. Immunolocalization of beta- and gamma-chains was homogeneously distributed on the cell surfaces before stimulation, while crosslinking with multivalent antigen, which elicited optimal degranulation, caused a distinct aggregation of these signaling chains on the cell membrane. Moreover, only gamma- but not beta-chains were aggregated during the stimulation that evoked suboptimal secretion. These findings suggest that high-affinity IgE receptor beta- and gamma-chains do not co-aggregate but for the most part form homogenous aggregates of beta-chains or gamma-chains after crosslinking.

Direct detection of hepatitis B virus gene integrated in the Alexander cell using fluorescence in situ polymerase chain reaction.

Prolonged infection of hepatitis B virus (HBV) is reported to cause hepatocellular carcinoma (HCC) via liver cirrhosis. However, it is still unknown whether the HCC is induced by the HBV DNA integration or by inflammatory stimulation during the phase of liver cirrhosis. The aim of this study is to determine the intracellular or intranuclear distribution of HBV DNA with a highly sensitive assay. Here we directly detected the integration of HBV DNA by fluorescence in situ polymerase chain reaction (FISPCR). Since FISPCR products directly incorporate rhodamine-4-dUTP, the nucleus of Alexander cells integrated with HBV gene reacted with the HBV primers emits obvious fluorescence. The fluorescence values which were measured with an imaging analyzer show a significant difference between Alexander cells as compared to the controls. In conclusion, the target sequences of HBV were specifically amplified as fluorescent DNA after the present FISPCR procedure. This method could provide a novel and simple strategy for determining the quantitative role of viral DNA integration in oncogenesis.

A quantitative enzyme-linked immunosorbent assay for Dermatophagoides pteronyssinus-specific immunoglobulin G.

A monoclonal mouse anti-human IgG was used to develop an enzyme-linked immunosorbent assay (ELISA) for the measurement of Dermatophagoides pteronyssinus (DP)-specific IgG in human sera. This monoclonal antibody (HG2-25) binds to all subclasses of IgG but not to IgA, IgM, or IgE. For the assay, the DP antigen is coated firmly on polystyrene beads through physical adsorption and any leakable antigen is washed off. The assay gives satisfactory reproducibility and parallelism of the dilution curves. Using 0.1% human serum albumin as a substitute for the DP-specific IgG preabsorbed diluent gave extremely low backgrounds and high sensitivity. Horseradish peroxidase-labeled HG2-25 prepared with the optimum degree of conjugation and free of polymerized conjugates gave responses fairly proportional to the doses. This ELISA gives a satisfactory recovery and is not affected by nonspecific IgG levels in human sera.

Novel development of exciton-coupled circular dichroism based on induced axial chirality.

[reaction--see text] A simple method for determining the absolute configuration of chiral alcohols with a unique chromophoric reagent 1 based on induced exciton chirality has been developed. Practical usefulness of the present method was demonstrated by the determination of the absolute configuration of 17,18-dihydroxybergamottin.

A novel method for detection and counting of single bacteria in a wide field using an ultra-high-sensitivity TV camera without a microscope.

We describe a novel method for enumeration of bacteria, based on the principle that small, light emitting particles on a flat surface can be easily and rapidly detected and counted using an ultra-high-sensitivity TV camera. To test this method, we obtained TV images of individual cells of a luminous bacterium on a membrane filter without the use of a microscope. The positions of the luminous points in the TV images were almost the same as the positions of the bacterial colonies after growth. Our results show that the single cells can be efficiently detected and counted by our method if they emit light or can be stimulated to emit light.

Rapid detection and counting of single bacteria in a wide field using a photon-counting TV camera.

Using Escherichia coli as a model bacterium, we tested a photon-counting method for enumeration of bacteria. This method is based on the principle that microscopic sized luminous particles in a wide field can be directly detected and counted using a photon-counting TV camera without the use of a microscope. E. coli cells were labeled with peroxidase and luminescence induced by adding a luminol-based reaction mixture. The number of luminous spots in the TV images was in good agreement with the number of bacterial colonies grown from labeled cells. The results show that our method provides a rapid and easy microbial counting system for such purposes as clinical diagnosis, microbial analysis in food, and environmental assessment.

Stimulation of neurotrophic factor secretion from 1321N1 human astrocytoma cells by novel diterpenoids, scabronines A and G.

Glial cells release neurotrophic factors that maintain neurons functionally. When rat pheochromocytoma cells (PC-12) were cultivated with the conditioned medium of human astrocytoma cells (1321N1) incubated with the new diterpenoids, scabronines A and G, isolated from Sarcodon scabrosus, they changed their morphology and there was neurite outgrowth. The scabronines increased the expression of mRNA for nerve growth factor (NGF), and the secretion of NGF from 1321N1 cells in a concentration-dependent manner. However, the enhanced neurite outgrowth produced by the conditioned media was slightly inhibited by NGF neutralizing antibody, and the concentration of NGF released in response to the scabronines was insufficient to cause differentiation. These results suggest that scabronines cause the secretion of other factors together with NGF from 1321N1 cells. The diterpenoids are useful drugs to clarify the mechanism of synthesis and secretion of neurotrophic factors.

Mobility of Impatiens capensis flowers: effect on pollen deposition and hummingbird foraging.

Flexible pedicels are characteristic of birdpollinated plants, yet have received little attention in studies of hummingbird-flower interactions. A major implication of flexible pedicels is that flowers may move during pollination. We examined whether such motion affected interactions between ruby-throated hummingbirds (Archilochus colubris) and jewelweed (Impatiens capensis) by increasing pollen deposition and by altering the effectiveness of nectar removal. For I. capensis, flower mobility enhanced pollen deposition: birds had significantly longer contact with anthers and more pollen deposited on their bills and crowns when foraging at mobile flowers than at flowers that had been experimentally immobilized. In contrast, flower mobility imposed a cost on hummingbirds by significantly increasing their handling times and reducing their extraction rates relative to their interactions with immobile flowers. Field observations indicated that the motion observed during hummingbird visits did not occur when bees (Bombus spp., Apis mellifera) visited I. capensis flowers, which suggests that the mobility of I. capensis flowers is an adaptation for hummingbird pollination.

[Production of useful recombinant proteins using Namalwa KJM-1 cells adapted to serum-free medium].

We investigated the basic technology of cell culture conditions for production of useful substances such as cytokines, and related proteins produced by Namalwa cells. Namalwa cells, human B lymphoblastoid cells, were used for large scale production of alpha-interferon. Namalwa KJM-1, a subline of Namalwa cells, adapted to serum- and albumin-free medium, can grow at a high density above 1 x 10(7) cells/ml in suspension manner by the use of a perfusion culture system, Biofermenter, containing a cone-type cell-sedimentation column as cell separator. Several kinds of cytokine cDNA can be introduced and expressed in Namalwa KJM-1 cells. Some of these were produced in large quantities by use of a gene amplification method with dhfr, even through the Namalwa KJM-1 cells contained endogenous dhfr genes. For stable production of the target protein, Namalwa KJM-1 cells are very useful host cells, because they have no effective endogenous protease activity in the conditioned medium. Using Biofermenter with micro-silicone fibers and a dialysis system, the specific productivity of the target proteins was not depressed at a high cell density.

[Induction of LAK cells by high density dialyzing culture device and its cytotoxicity].

Lymphokine activated killer (LAK) cells are generated by culture of lymphocytes with interleukin 2 (IL-2) in short term culture (3 to 5 days) and are used for adoptive immunotherapy for advanced cancer patients. The culture condition hitherto reported are essentially based on the rotating culture system, in which the maximum cell density was at 2 X 10(6) cell/ml and the cell recovery was usually less than 100%. The inability to induce LAK cells efficiently in vitro made the culturing of cells for therapy rather difficult and costly work because the mean infusion dose of LAK cells of one patient requires more than 1 X 10(10)/ml. We have therefore attempted to culture lymphocytes in 10 times higher concentration comparing with conventional methods. By using a new dialyzing culture system under continuous regulation of the amount of infused IL-2, nutrition medium, and pO2 and pCO2, we could culture cells at 2 X 10(7)/ml for more than 21 days and the resulted LAK cells showed a 100 times increase of activity on a per cell basis. By limiting dilution procedure, these killer cells mostly express T cell markers such as CD3 and CD8 but dose not express CD16.

Change of retinal correspondence in monocularly reduced intensity of stimulus.

We analyzed the retinal correspondence with a phase difference haploscope on reducing the stimulus intensity of a monocular image with a series of neutral density filters. Ninety-one exotropes were examined by this method. Five cases changed from normal to anomalous correspondence when the stimulation of the strabismic eye was reduced. Two cases showed anomalous correspondence without a filter, but normal correspondence with a reduced stimulus of the normal eye. All these seven cases showed normal correspondence with any other test. The results suggest that masked anomalous correspondence becomes manifest in some cases when the strabismic eye is stimulated more intensely than the normal eye. These cases display both normal and anomalous correspondence and this condition may be called dual correspondence.