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.

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.

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.

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.

[Detection of O,O,S-trimethyl phosphorodithioate, an impurity in phenthoate (PAP), in komatsuna].

An unknown peak (peak A) was detected in a mass chromatogram of komatsuna extract containing a high concentration of phenthoate (PAP), and it was considered to be O,O,S-trimethyl phosphorodithioate (OOS). Although it is generally known that OOS exists as an impurity in technical malathion and PAP, it has not been reported that OOS is present in crops. Since an OOS standard is not commercially available, OOS was separated and purified from commercial emulsifiable malathion. Peak A was confirmed to be OOS by GC/MS using the purified OOS. The concentration of OOS was estimated to be 0.02 microgram/g. It is supposed that OOS was detected in crops because they contained a high concentration of PAP residue.

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.

The McCoy laryngoscope, external laryngeal pressure, and their combined use.

The efficacy of the McCoy laryngoscope, external laryngeal pressure, and their combination to improve the laryngoscopic view was evaluated in 219 patients and compared with the Macintosh laryngoscope. An experienced laryngoscopist performed laryngoscopy twice using the Macintosh laryngoscope and the McCoy laryngoscope in a random sequence, and external laryngeal pressure was applied in each laryngoscopy with the laryngoscopist's right hand. The laryngoscopic view obtained was graded on our modified Cormack's method. Without external laryngeal pressure, the McCoy laryngoscope provided a better laryngoscopic view than that obtained by the Macintosh laryngoscope (P < 0.001, signed rank test), but the view was worse than that with the Macintosh laryngoscope under external laryngeal pressure (P < 0.001). The McCoy laryngoscope combined with external laryngeal pressure provided a better view than the Macintosh laryngoscope with external laryngeal pressure (P < 0.001).

C8/119S mutation of major mite allergen Derf-2 leads to degenerate secondary structure and molecular polymerization and induces potent and exclusive Th1 cell differentiation.

Hyposensitization therapy for atopic diseases has been conducted for decades but suffered from many problems including anaphylactic reactions. We previously developed a mutant protein of the major mite allergen Derf-2, C8/119S, which showed reduced binding to IgE. The C8/119S mutant was shown to exhibit more efficient hyposensitizing effect than Derf-2 in the animal model of allergic bronchial asthma. In the present study, we indicate that C8/119S exhibits markedly augmented immunogenicity for the proliferation of Derf-2-specific human T cells and T cell clones irrespective of the epitope specificity as compared with Derf-2. Furthermore, C8/119S has induced potent and almost exclusive differentiation of Th1 cells from the peripheral blood of atopic patients in vitro. Neither Ag dosage effect nor absence of B cell-mediated Ag presentation could fully account for these effects. C8/119S has been indicated to lose the characteristic beta-barrel structure as judged by circular dichroism spectroscopic analysis and to polymerize solubly in physiological condition. Heating of Derf-2 also caused less stable molecular aggregation, but it hardly affected the secondary structure and failed to induce such a polarity toward the Th1 cell differentiation. These results have indicated that the degenerate secondary structure of C8/119S leading to stable molecular polymerization is primarily responsible for the marked increase in T cell-immunogenicity and the induction of exclusive Th1 cell differentiation in atopic patients. It has been suggested strongly that the recombinant C8/119S protein can provide an effective Ag with the least risk of anaphylaxis for allergen immunotherapy against house dust mite in human.

Comparison of skin prick test with serially diluted wild-type and genetically engineered recombinant Der f2.

BACKGROUND: C8/119S, a genetically engineered less allergenic mutant of group II allergen (Der f2) of house dust mite, Dermatophagoidesfarinae, was constructed in order to reduce the risk of anaphylactic reactions of allergen specific immunotherapy. OBJECTIVE: To further evaluate, with a larger number of mite-allergic patients, the safety of C8/119S for the treatments of humans. METHOD: We tested the dose-dependent responses of 20 mite-allergic volunteers to a skin prick test with C8/119S and wild-type recombinant Der f2 and compared the biologic potentials of these allergens to induce type I allergic reactions. In a separate experiment, we compared IgE binding capacities to C8/119S and to wild-type recombinant Der f2 in individual sera from 34 mite-allergic donors. RESULTS: The concentration of C8/119S needed to induce positive skin prick test (SPT) reaction was at least 100 times more than that of recombinant Der f2 in 95% of the volunteers tested. Consistent with this result, IgE binding data showed that 85% of the mite-allergic donors had little or no detectable IgE bound to C8/119S. Our data also shows that a minority of mite-allergic patients responded in a similar manner to both C8/119S and wild-type recombinant Der f2. CONCLUSION: Our data confirms that C8/119S is much less allergenic and thus can be used safely for immunotherapy of most of mite-allergic patients. Care should still be taken because, in a minority of patients, C8/119S may cause similar type I allergic reactions as does wild-type recombinant Der f2.

[Recent pollen sensitization and its possible involvement in allergic diseases among children in a pediatric allergy clinic].

We studied the rate of sensitization to several pollen allergens as well as to house dust mites in 226 children visiting our pediatric allergy clinic during the past 3 years (from April 1996 to March 1999). The allergens studied were Sugi (Japanese cedar pollen, Cryptomeria japonica), Kamogaya (Dactylis gromerata), Butakusa (ragweed, Ambrosia artemisiifolia), and Der f (house dust mite, Dermatophagoides farinae). The presence of nasal symptoms (either seasonal and perenial) was checked in 97 children visiting the clinic in March 1999. Overall average sensitization rates were 82.3% for Der f, 53.1% for Sugi, 38.5% for Kamogaya, and 17.1% for Butakusa. Among children aged 12 or more, sensitization rates for Sugi and Kamogaya were much higher (68.8%, 56.3%, respectively). Those who had seasonal nasal symptoms showed significantly higher rates of sensitization to the pollens. However, more than half of patients without nasal symptoms, 62.8% of whom had only atopic dermatitis (AD), also showed sensitization to the pollens. Several possible factors accounting for pollen sensitization in children with only AD and no sasal symptoms, such as existence of occult allergic rhinitis, future onset of allergic rhinitis, or pollen as directly aggravating factor of AD, need to be evaluated by careful follow-up of these cases.

Relationships between atopy and lung function: results from a sample of one hundred medical students in Japan.

BACKGROUND: The prevalence of allergic diseases has been increasing dramatically and several studies have shown that atopy is related to asthmatic symptoms and bronchial hyperresponsiveness. OBJECTIVE: To observe the relationships between atopic status and asthmatic predisposition (obstructive change in lung function) in apparently healthy young adults in Japan. METHODS: A sample of 100 healthy Japanese medical students were subjected to a skin prick test for 11 common aeroallergens and food allergens, and their spirometric lung function was measured. RESULTS: Surprisingly, 90% of them showed a positive prick test result for at least one of the 11 allergens tested, and 59% of them showed allergic responses to more than three allergens. The positive rate for Dermatophagoidesfarinae (Der) was the highest (71.0%), followed by house dust (57.0%), Dactylois gloinerata (42.0%), Cryptomeria gromerata (Cry) (40.0%), and cat fur (39.0%). Furthermore, there was no statistical difference in the positive rates for Der and Cry between groups with and without either the present illness or past history of any of the three major allergic diseases: bronchial asthma (BA), atopic dermatitis (AD), or allergic rhinitis (AR). Compared with the positive rates for these aeroallergens, those for food allergens were much lower (4% to 9%). Several lung function parameters, including the levels of FEV1% and %V50 which reflect obstructive pulmonary changes, showed significant negative correlation to the number of skin prick test-positive allergens. The same correlation was observed for groups without either the present illness or past history of BA. CONCLUSION: These data suggest that those who are multi-allergic tend to feature subclinical asthma-like changes in their lung functions. Further studies are needed to determine whether this multi-allergic status can lead to future onset of asthma or other allergic diseases.

Month of birth and prevalence of atopic dermatitis in schoolchildren: dry skin in early infancy as a possible etiologic factor.

BACKGROUND: Month of birth has been shown to affect later development of allergic diseases. OBJECTIVE: We sought to evaluate the relationship between month of birth and the prevalence of atopic dermatitis (AD) in a large-scale general population of schoolchildren and to elucidate the possible mechanism for this relationship. METHODS: Questionnaire data on the prevalence of allergic diseases were obtained for 33,725 schoolchildren aged 7 to 15 years. In a separate study the water-holding capacity of "uninvolved" skin was compared for children with and without AD. RESULTS: We found striking differences in the prevalence of AD according to the month of birth (chi2 = 34.9, P <.0001). Overall, those born in autumn showed the highest (7.5%), and those born in spring showed the lowest (5.5%), prevalence of AD. There was little or no such tendency for the prevalence of bronchial asthma (chi2 = 17.2, P =.103) and allergic rhinitis (chi2 = 24, P =.01). We found no statistical variation across birth month in the ratio of AD with no other allergic disease/total AD, indicating that this deviation was observed whatever the allergic predisposition of the subjects. In a separate study a significantly lower water-holding capacity of uninvolved skin was observed in children with AD even from early infancy. CONCLUSION: These findings lead us to speculate that the climate in early infancy affects the skin condition and that those born in autumn have dry skin in early infancy, which may ultimately result in a higher prevalence of AD among young schoolchildren. This might be at least one of the "nonallergic" etiologic factors of this complex disease.

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.

Synthesis and nematocidal activity of diarylnonanoids related to malabaricones.

Twenty diarylnonanones were synthesized and their nematocidal activity was examined. Among those, the p-hydroxy compound 16 exhibited the strongest activity comparable to the natural diarylnonanoids, malabaricones A and C. Diarylundecanoid 57 also showed appreciable activity.

[Re-evaluation of multi-allergen skin prick test for infants with atopic dermatitis--clinical relevance and evaluation by mothers].

We performed skin-prick tests (SPT) for 8 food and inhalant allergens on 55 infants (between 3 months and 2 years of age) with atopic dermatitis (AD) at their initial visit to our allergy clinic. SPT results were compared with those of radioallergosorbent tests (RAST) and the severity of AD symptoms. We also administered a questionnaire-based survey of 46 patients mothers to see how they evaluated SPT compared to blood tests. SPT for egg white had the highest positive rate (91%) and far exceeded that for other allergens. More than two allergens showed positive in more than half of the patients, and about 30% of them showed positive reactions to more than three allergens. Concordance rate between SPT and RAST was 78.6%. Patients showing positive reactions to multi-allergens tended to have more severe AD symptoms. Mothers appreciated the SPT test and felt that quick results for multi-allergens was the greatest advantage of SPT. More than 90% of the mothers wanted the allergic status of their next children to be evaluated with SPT. Especially, more than 30% of the mothers preferred SPT than RAST as initial screening test. As SPT is harmless, easy to administer even in infancy, and has different advantages for those of RAST, this method deserves further re-evaluation as a means of identifying allergic status especially among infants.

A useful method to evaluate bone resorption inhibitors, using osteoclast-like multinucleated cells.

Since excessive bone resorption in postmenopausal osteoporosis is a pathological manifestation of the disease, it is important to control bone resorption activity of osteoclasts as a means of controlling the disease. To screen bone resorption inhibitors, a simple and quantitative method to assay bone resorption is needed. However, it has been difficult to prepare a lot of osteoclasts required for the screening of many compounds in vitro. We used the method for the preparation of mouse osteoclast-like multinucleated cells in vitro and developed a useful method in which osteoclast-like multinucleated cells were placed on dentin slices and the calcium released from dentin into the culture medium was measured. Under the optimal conditions, the increase of the calcium concentration caused by bone resorption activity of the osteoclast-like cells was significant and inhibited by calcitonin in a dose-dependent manner. We also examined the inhibitory effect of calcitonin on the pit area caused by bone resorption and found that the decrease of the calcium released from dentin was correlated with that of the pit area. Furthermore, several known bone resorption inhibitors such as bisphosphonate, bafilomycin A1, and herbimycin A showed inhibitory effects on the calcium release from dentin slices. Thus, this simple method provides us a useful screening system to find bone resorption inhibitors with novel mechanisms.

[A epidemiologic study on the prevalence of the allergic diseases in school children in Kyoto City].

UNLABELLED: The prevalence of allergic diseases in school children in Kyoto City (17,906 children) was examined with the questionnaire which was prepared by the Study Group of Epidemiology of Allergic Diseases funded by the Ministry of Public Welfare in 1993. RESULTS: 1) The number of valid reply was 16,176 (reply rate 90.3%). The reply rate of each question was from 89.5% to 98.9% (average 95.7%). 2) The prevalence of bronchial asthma was 4.9% in the elementary school children, 3.5% in the junior high school children and 4.5% in total, and the prevalence in boys was higher than girls (ratio 1.6). The prevalence of wheezing was 6.5%, 2.7% and 5.5%, respectively, and the sex ratio was 1.2. 3) The prevalence of atopic dermatitis was 5.3% in elementary school children, 4.0% in junior high school children and 5.0% in total, and the prevalence in boys was lower than girls (ratio 0.87). 4) The prevalence of allergic rhinitis was 19.8% in elementary school children, 21.2% in junior high school children and 20.3% in total, and the prevalence in boys was higher than girls (ratio 1.3). 5) The prevalence of allergic conjunctivitis was 11.9% in elementary school children, 15.4% in junior high school children and 13.0% in total and the prevalence in boys was almost same as girls (ratio 0.98). 6) The prevalence of any allergic diseases was 32.2% in elementary school children, 31.7% in junior high school children and 32.1% in total and the prevalence in boys was higher than girls (ratio 1.2).