Halo Structure of the Neutron-Dripline Nucleus

The heaviest bound isotope of boron ^{19}B has been investigated using exclusive measurements of its Coulomb dissociation, into ^{17}B and two neutrons, in collisions with Pb at 220 MeV/nucleon. Enhanced electric dipole (E1) strength is observed just above the two-neutron decay threshold with an integrated E1 strength of B(E1)=1.64±0.06(stat)±0.12(sys) e^{2} fm^{2} for relative energies below 6 MeV. This feature, known as a soft E1 excitation, provides the first firm evidence that ^{19}B has a prominent two-neutron halo. Three-body calculations that reproduce the energy spectrum indicate that the valence neutrons have a significant s-wave configuration and exhibit a dineutronlike correlation.

First Observation of

The most neutron-rich boron isotopes ^{20}B and ^{21}B have been observed for the first time following proton removal from ^{22}N and ^{22}C at energies around 230 MeV/nucleon. Both nuclei were found to exist as resonances which were detected through their decay into ^{19}B and one or two neutrons. Two-proton removal from ^{22}N populated a prominent resonancelike structure in ^{20}B at around 2.5 MeV above the one-neutron decay threshold, which is interpreted as arising from the closely spaced 1^{-},2^{-} ground-state doublet predicted by the shell model. In the case of proton removal from ^{22}C, the ^{19}B plus one- and two-neutron channels were consistent with the population of a resonance in ^{21}B 2.47±0.19 MeV above the two-neutron decay threshold, which is found to exhibit direct two-neutron decay. The ground-state mass excesses determined for ^{20,21}B are found to be in agreement with mass surface extrapolations derived within the latest atomic-mass evaluations.

Nucleus

The unbound nucleus ^{26}O has been investigated using invariant-mass spectroscopy following one-proton removal reaction from a ^{27}F beam at 201 MeV/nucleon. The decay products, ^{24}O and two neutrons, were detected in coincidence using the newly commissioned SAMURAI spectrometer at the RIKEN Radioactive Isotope Beam Factory. The ^{26}O ground-state resonance was found to lie only 18±3(stat)±4(syst) keV above threshold. In addition, a higher lying level, which is most likely the first 2^{+} state, was observed for the first time at 1.28_{-0.08}^{+0.11} MeV above threshold. Comparison with theoretical predictions suggests that three-nucleon forces, pf-shell intruder configurations, and the continuum are key elements to understanding the structure of the most neutron-rich oxygen isotopes beyond the drip line.

Observation of low- and high-energy Gamow-Teller phonon excitations in nuclei.

Gamow-Teller (GT) transitions in atomic nuclei are sensitive to both nuclear shell structure and effective residual interactions. The nuclear GT excitations were studied for the mass number A = 42, 46, 50, and 54 "f-shell" nuclei in ((3)He, t) charge-exchange reactions. In the (42)Ca → (42)Sc reaction, most of the GT strength is concentrated in the lowest excited state at 0.6 MeV, suggesting the existence of a low-energy GT phonon excitation. As A increases, a high-energy GT phonon excitation develops in the 6-11 MeV region. In the (54)Fe → (54)Co reaction, the high-energy GT phonon excitation mainly carries the GT strength. The existence of these two GT phonon excitations are attributed to the 2 fermionic degrees of freedom in nuclei.

Problems in the regulation of genetic tests in Japan: what can we learn from direct-to-consumer genetic tests?

As one of the countries that have invested greatly in the field of bioscience, Japan is facing difficulties introducing human genetic research to the market. A key issue is how to regulate the quality of genetic testing. Since genetic testing is a part of clinical laboratory tests, the regulatory framework for these tests should cover the regulation of genetic testing. Nevertheless, the quality of clinical laboratory tests has been regulated largely by the authority of medical professionals. The fact that genetic testing can be provided without supervision of medical professionals reveals the necessity for the regulation of quality of genetic testing. While medical geneticists have publicly criticized direct-to-consumer (DTC) genetic testing, a group of industries related to DTC genetic testing have established self-regulatory guidelines on the quality control of genetic analysis, based on the OECD guidelines. This article describes the regulatory framework for clinical laboratory tests including genetic tests, and the gaps in regulation, which are particularly highlighted by the appearance of DTC genetic testing. Furthermore the current initiatives taken by different organizations, especially the self-regulatory initiatives by related industries, will be discussed. To conclude the article, recommendations to improve the situation will be made.

Gamow-Teller strength distributions in 48Sc by the 48Ca(p,n) and 48Ti(n,p) reactions and two-neutrino double-beta decay nuclear matrix elements.

The double-differential cross sections for the 48Ca(p,n) and 48Ti(n,p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) components. The integrated GT strengths up to an excitation energy of 30 MeV in 48Sc are 15.3+/-2.2 and 2.8+/-0.3 in the (p,n) and (n,p) spectra, respectively. In the (n,p) spectra additional GT strengths were found above 8 MeV where shell models within the fp shell-model space predict almost no GT strengths, suggesting that the present shell-model description of the nuclear matrix element of the two-neutrino double-beta decay is incomplete.

Correlations between bone mineral density and demographic, lifestyle, and biochemical variables in community-dwelling Japanese women 69 years of age and over.

INTRODUCTION: A few epidemiologic studies have comprehensively attempted to identify risk factors for low bone mineral density (BMD) in elderly Asian women. The purpose of this study was to identify demographic, lifestyle, and biochemical factors correlated with BMD in elderly Japanese women 69 years of age and over. METHODS: The study design was cross-sectional. The subjects were 583 ambulatory women aged 69 years and over, and their average age was 74.3 (SD 4.4) years. Predictor variables were age, reproductive history, anthropometric indices, grip strength, calcium intake, lifestyle information, and serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D (1,25(OH)(2)D), osteocalcin (OC), and undercarboxylated osteocalcin (ucOC) values. The outcome variable was forearm BMD measured with a DTX-200 osteometer. RESULTS: Simple linear regression analyses showed that BMD was significantly positively associated with body height, weight, body mass index, grip strength, serum albumin concentration, and "housework," and negatively associated with age, years since menopause, age at menarche, number of children, serum 1,25(OH)(2)D concentration, serum OC concentration, and ucOC concentration. The stepwise multiple regression analysis showed that weight (beta=0.00316, SE=0.00028, R(2)=0.180), age (beta=-0.00321, SE=0.00050, R(2)=0.108), log-transformed serum OC (beta=-0.0445, SE=0.0064, R(2)=0.053), log-transformed serum 1,25(OH)(2)D (beta=-0.0401, SE=0.0074, R(2)=0.050), "farmwork" (beta=0.00904, SE=0.00426, R(2)=0.005), and serum 25(OH)D concentration (beta=0.000281, SE=0.000120, R(2)=0.003) were significantly associated with BMD. CONCLUSION: It was concluded that body weight is a major predictor of forearm BMD among the factors measured in this study in independent Japanese women 69 years of age and over and that serum 1,25(OH)(2)D concentration may be associated with cortical BMD. Maintenance of body weight is very important for maintaining BMD in this population, unless a large weight aggravates obesity-related diseases. A follow-up study is needed to confirm these findings.

HLA class II antibodies in transfusion-related acute lung injury.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is a serious, sometimes fatal, complication of transfusion. Granulocyte and HLA class I antibodies present in blood donors have been associated with TRALI. HLA class II antibodies have recently been described in a few cases of TRALI. STUDY DESIGN AND METHODS: Donors involved in TRALI reactions reported to a blood center over an 18-month period were tested for HLA class I and II antibodies as well as granulocyte antibodies, if HLA antibodies were not identified. RESULTS: HLA class II antibodies were identified, in at least one donor, in 7 (64%) of 11 cases of TRALI. HLA class I antibodies were identified in combination with HLA class II antibodies in 5 of these 7 cases. HLA class I antibodies were exclusively identified in 2 cases. Granulocyte antibodies were identified in 1 case, and no antibodies were identified in another. CONCLUSION: In addition to HLA class I antibodies, HLA class II antibodies are associated with TRALI. Testing of donors for HLA class II antibodies as well as HLA class I and granulocyte antibodies is recommended as part of the investigation of suspected cases of TRALI.

Crystal structure-reactivity correlation in single-crystalline photochromism of 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene.

Single-crystalline photochromism of 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene 1a was followed in situ by X-ray crystallographic analysis. The crystal of 1a has two molecules with different conformations in the crystallographic asymmetric unit. The X-ray analysis of the photoirradiated crystal showed that the photocyclization reaction of the molecule with the shorter distance between the reactive carbons prevails over the reaction of the other molecule. The mechanism has been discussed based on the calculation of the electronic transitions of the two molecules in the different conformations. The photocyclization quantum yield was determined to be 1 (100%) in the crystal.

Higher incidence of diabetic nephropathy in type 2 than in type 1 diabetes in early-onset diabetes in Japan.

BACKGROUND: Whether the type of diabetes, race, and year and age of diagnosis affect the incidence of diabetic vascular complications is unknown. That both type 1 and type 2 diabetes occur in the young Japanese population prompted us to investigate whether the type of diabetes and the year of diagnosis are related to the incidence of nephropathy. METHODS: Of the 17,256 diabetic patients who visited the outpatient clinic at our diabetes center between 1965 and 1990, 1578 (9.1%) had early-onset diabetes (diagnosed before the age of 30); of these, 620 (39%) had type 1, and 958 (61%) had type 2 diabetes. The incidence of nephropathy was analyzed in the patients according to postpubertal duration and year of diagnosis. RESULTS: The cumulative incidence of nephropathy after 30 years of postpubertal diabetes was significantly higher (P < 0.0001) in type 2 diabetic patients (44.4%, 95% CI, 37.0 to 51.8%) than in type 1 diabetic patients (20.2%, 95% CI, 14.9 to 25.8%). The incidence of nephropathy among type 1 diabetic patients has declined during the past two decades, whereas it has not among type 2 diabetic patients. The rate ratio for type 2 diabetic patients diagnosed between 1980 and 1984 relative to type 1 diabetic patients diagnosed in the same period was 2.74 (95% CI, 1. 17 to 6.41). CONCLUSIONS: The incidence of nephropathy has declined in Japanese patients with type 1 but not in those with type 2 diabetes. In young Japanese patients, because of the higher incidence of nephropathy in type 2 diabetes and the higher prevalence of type 2 than type 1 diabetes, type 2 diabetes is likely the major cause of diabetic nephropathy.

Prevalence of anorexia nervosa and bulimia nervosa in a geographically defined area in Japan.

OBJECTIVE: Little has been understood regarding the frequency of eating disorders in Japan. This study was designed to identify the prevalence of anorexia nervosa (AN) and bulimia nervosa (BN) in Japan. METHOD: We asked doctors in all of the relevant medical facilities (130 hospitals and 1,326 clinics) in Niigata Prefecture to report patients with DSM-IV-diagnosed eating disorders who appeared or were admitted between 20-24 October 1997. The response rate was 94.4%. RESULTS: The estimated point prevalences of AN and BN were 4.79 and 1.02, respectively, per 100,000 females. Specifically for the age group of 15-29 years, the prevalence of AN was 17.10 and that of BN 5.79. DISCUSSION: The prevalence of AN and BN in Japan is lower than that for European Caucasian populations. This result may be due to cultural and ethnic differences and/or it may be a transient phenomenon.

Serum 25-hydroxyvitamin D levels in active women of middle and advanced age in a rural community in Japan.

There have been few epidemiologic studies on vitamin D status in Asians. The purpose of this study was to investigate the 25-hydroxyvitamin D (25[OH]D) levels in active women of middle and advanced age in Japan. We targeted 236 women who participated in an annual health check-up program in September 1997. Among them, 160 women were examined. Serum 25(OH)D2 and 25(OH)D3 levels were determined with high-performance liquid chromatography. In addition, the study included survey questions regarding age, body weight and height, occupation, use of skin protection, clinical and reproductive histories, and lifestyles. The average age was 65.6 y (SD = 8.3). The mean concentrations of 25(OH)D2 and 25(OH)D3 were 0.5 (SD = 3.2) nmol/L and 78.3 (SD = 17.8) nmol/L, respectively. None of the subjects showed hypovitaminosis D (25[OH]D < 37.0 nmol/L). Concentrations of 25(OH)D3 did not change with age (r = -0.079, P = 0.32), nor did other variables associated with 25(OH)D3 concentrations except for "engaging in farming" (P = 0.03) in the occupational category. These findings indicate that 25(OH)D levels in active middle- and advanced-aged women in Japan have appropriate vitamin-D status. Studies to elucidate and assess the dietary intake of vitamin D in Japanese women can be of further benefit.

Donor cell induced CD69 expression and intracellular IL-2 and IL-4 production by peripheral blood lymphocytes isolated from kidney transplant recipients.

Flow cytometry assays, which measure CD69 activation and intracellular cytokine production, have been used to measure peripheral blood lymphocyte (PBL) responses to in vitro antigen exposure. In the present study, we show that, in healthy individuals and immunosuppressed kidney transplant recipients, CD69 expression and intracellular cytokine production by peripheral blood T cells compare favorably to thymidine uptake as a measure of PBL response to alloantigen in mixed leukocyte culture (MLC). Heparinized whole blood from 23 healthy individuals was incubated for 24-48 h with 3rd party allogeneic monocytes; blood from twelve kidney transplant recipients was incubated with monocytes from their kidney donor and with monocytes from unrelated individuals. The percentage of T cells expressing surface CD69 or intracellular IL-2 or IL-4 was determined by 3-color flow cytometry. We identified 5 donor-specific response patterns in our kidney transplant group. One transplant recipient was hyporesponsive; his cells did not express CD69 or produce IL-2 in response to either donor or 3rd party allogeneic cells. All other transplant recipients expressed CD69 and IL-2 in response to 3rd party allogeneic cells. Two had no response to donor cells (donor-specific hyporesponsiveness), three had donor-specific anergy (CD69 expression without cytokine production in response to donor cells), five had a donor-specific Thl response (CD69 expression and IL-2 production in response to donor cells), and one had a donor-specific Th2 response (CD69 expression and IL-4 but not IL-2 production in response to donor cells). Rapid measures of donor-specific hyporesponsiveness such as CD69 activation antigen expression and intracellular cytokine production may prove valuable in monitoring lymphocyte function and aid in the long-term management of kidney transplant recipients.

Assessment of insulin resistance in acromegaly associated with diabetes mellitus before and after transsphenoidal adenomectomy.

With a euglycemic hyperinsulinemic clamp method, whole-body insulin resistance was assessed in 6 cases with acromegaly associated with diabetes mellitus before and after transsphenoidal adenomectomy. The glucose infusion rate (GIR) correlated well with the plasma IGF-I level but poorly with that of GH. Further improvement in insulin sensitivity occurred 3-4 months after operation without substantial changes in plasma levels of both GH and IGF-I or glycemic control. These results indicate that GH excess can induce insulin resistance in association with plasma IGF-I and also through undefined secondary effect.

Polymorphism at codons 114, 116, 145, and 163 muddle the typing of HLA-B*1304.

Genetic exchanges often muddle the typing of HLA class I molecules, this is also the case for HLA-B*1304. Serologic and molecular DNA class I typing report a B15/B55 type for cell 847, whereas DNA sequencing finds B*5501/B*1304. HLA-B*1304 differs by no more than four amino acids from other HLA-B13 molecules, a comparative analysis of the B13 and B15 families was therefore performed to determine why serologic and molecular DNA approaches report a B15 type for B*1304. Comparisons demonstrate that limited differences individuate the B15 and B13 molecules such that the genetic recombination of codons 145 and 163 in the class I heavy chain's alpha 2 alpha helix prompt B*1304 to exhibit a B15X21 pattern of serologic cross-reactivity. Molecular DNA class I typing approaches are also swayed by genetic recombinations to type B*1304 as a B15 molecule: B15-like nucleotide sequences encoding residues 114, 116, and 145, lead B*1304 to exhibit a B15 PCR amplification pattern. Thus, genetic exchanges encoding key amino acids in the class I heavy chain lead molecular and serologic typing approaches to categorize HLA-B*1304 as a member of the B15 family.

Abnormalities of T waves in effort angina pectoris patients at rest evaluated by spatial velocity electrocardiogram.

The normal shape of the T wave on the standard 12-lead electrocardiogram (ECG) is asymmetrical. The spatial velocity electrocardiogram (SVECG) is a method of recording the slope of the wave of the ECG and makes it possible to quantify the symmetry of the ECG-T wave. The aim of this study was to diagnose resting effort angina pectoris not detectable by conventional resting ECG using SVECG. We studied SVECG-T waves in effort angina pectoris patients with significant coronary artery stenosis but with normal resting ECG (AP group: 50 subjects) and in an age- and sex-matched normal controls (N group: 30 subjects). The SVECG is depicted as a simple differential wave, and all SVECG-T waves had two peaks. The first peak of the SVECG-T wave was designated as the 'a' wave and the second peak as the 'c' wave. The heights (a wave-mag, c wave-mag) and c wave-mag/a wave-mag ratio (c/a ratio) were calculated. The c/a ratio was significantly decreased in the AP group (1.52 +/- 0.29 vs 1.87 +/- 0.27, p < 0.0001). In cases below the cut off c/a ratio of 1.7, the diagnostic sensitivity, specificity and accuracy for effort angina pectoris were retrospectively evaluated to be 82%, 70% and 78%, respectively. The heights of the 'a' and 'c' waves correspond to the maximum slope of the ascending and descending limbs of the T wave on ECG. The symmetrization of the T wave on ECG is considered to occur when the c/a ratio decreases and approaches 1.0. In conclusion, the c/a ratio of the SVECG-T wave is a useful index to diagnose effort angina pectoris at rest when the resting ECG is normal.