Gamma-ray exposure from neutron-induced radionuclides in soil in Hiroshima and Nagasaki based on DS02 calculations

As a result of joint efforts by Japanese, US and German scientists, the Dosimetry System 2002 (DS02) was developed as a new dosimetry system, to evaluate individual radiation dose to atomic bomb survivors in Hiroshima and Nagasaki. Although the atomic bomb radiation consisted of initial radiation and residual radiation, only initial radiation was reevaluated in DS02 because, for most survivors in the life span study group, the residual dose was negligible compared to the initial dose. It was reported, however, that there were individuals who entered the city at the early stage after the explosion and experienced hemorrhage, diarrhea, etc., which were symptoms of acute radiation syndrome. In this study, external exposure due to radionuclides induced in soil by atomic bomb neutrons was reevaluated based on DS02 calculations, as a function of both the distance from the hypocenters and the elapsed time after the explosions. As a result, exposure rates of 6 and 4 Gy h(-1) were estimated at the hypocenter at 1 min after the explosion in Hiroshima and Nagasaki, respectively. These exposure rates decreased rapidly by a factor of 1,000 1 day later, and by a factor of 1 million 1 week later. Maximum cumulative exposure from the time of explosion was 1.2 and 0.6 Gy at the hypocenters in Hiroshima and Nagasaki, respectively. Induced radiation decreased also with distance from the hypocenters, by a factor of about 10 at 500 m and a factor of three to four hundreds at 1,000 m. Consequently, a significant exposure due to induced radiation is considered feasible to those who entered the area closer to a distance of 1,000 m from the hypocenters, within one week after the bombing.     

Production of Higher-quality Plastein from a Crude Single-cell Protein

From defatted n-paraffin-assimilating yeast cells, a crude protein was obtained by alkaliextraction followed by acid-precipitation. Then the protein was treated with ether until extractable substances were removed exhaustively at this stage. However, at the next stage where the ether-treated protein had been partially hydrolyzed with pepsin, when the hydrolysate was retreated with ether, it was found that ether-extractable substances totalling 270 mg/100 g were obtainable additionally. Chromatographic investigations demonstrated that the substances included significant amounts of aliphatic and aromatic hydrocarbons, some indoles, and a ubiquinone (n = 8).

From the protein hydrolysate (substrate) after the above ether-treatment, a plastein was synthesized with Bioprase under the specific conditions. The plastein was obtained as a precipitate when the whole reaction mixture was treated with aqueous ethanol or acetone. The quantity and quality (nitrogen content) of the plastein depended on the ethanol or acetone concentration. Roughly speaking, the higher the concentration, the more the plastein quantity. The converse relation held for the quality; a plastein precipitated by treatment solely with water showed a higher quality than any other case.     

Long-term Administration of Probiotics to Asymptomatic Pre-school Children for Either the Eradication or the Prevention of Helicobacter pylori Infection

Background:  The role of probiotics in the armamentarium remains to be defined. The aims of this study were to investigate whether the long-time administration of Lactobacillus gasseri OLL2716 (LG21) strain can eradicate H. pylori in asymptomatic pre-school children and/or prevent H. pylori infection.
Methods: A total of 440 children, from 5–7 years of age, attending a kindergarten in Thailand were screened by the Helicobacter pylori stool antigen (HpSA) test. Thereafter 132 H. pylori positive and 308 H. pylori negative children were recruited to eradication and randomized prevention arms, respectively. Children in the active and placebo treatment groups received Lactobacillus gasseri OLL2716 (LG21) containing cheese and ordinary cheese, respectively, for 12 months. Eradication was defined as reversion by HpSA at 12 months. Prevention was defined as persistently HpSA negative at 12 months.
Results:  Eighty-two of 132 H. pylori positive (62%) completed the eradication arm, of which 24 (29.3%) were negative at 12 months according to the HpSA test. In the randomized prevention arm, 123 of 156 (79%) and 99 of 122 (81%) completed active and placebo arms, respectively, of which 4.1% and 8.1%, respectively, were HpSA positive at 12 months based on a per-protocol analysis ( p  = .21).
Conclusion: Further trials are needed.     

The habitat disruption induces immune-suppression and oxidative stress in honey bees

The honey bee is a major insect used for pollination of many commercial crops worldwide. Although the use of honey bees for pollination can disrupt the habitat, the effects on their physiology have never been determined. Recently, honey bee colonies have often collapsed when introduced in greenhouses for pollination in Japan. Thus, suppressing colony collapses and maintaining the number of worker bees in the colonies is essential for successful long-term pollination in greenhouses and recycling of honey bee colonies. To understand the physiological states of honey bees used for long-term pollination in greenhouses, we characterized their gene expression profiles by microarray. We found that the greenhouse environment changes the gene expression profiles and induces immune-suppression and oxidative stress in honey bees. In fact, the increase of the number of Nosema microsporidia and protein carbonyl content was observed in honey bees during pollination in greenhouses. Thus, honey bee colonies are likely to collapse during pollination in greenhouses when heavily infested with pathogens. Degradation of honey bee habitat by changing the outside environment of the colony, during pollination services for example, imposes negative impacts on honey bees. Thus, worldwide use of honey bees for crop pollination in general could be one of reasons for the decline of managed honey bee colonies.     

Comparative mapping of the wheat chromosome 5A Vrn-A1 region with rice and its relationship to QTL for flowering time

 The vernalization gene Vrn-A1 on chromosome 5A is the predominant gene determining the spring/winter habit difference in bread wheat. Vrn-A1 was physically mapped using a set of deletion lines which located it to the region of chromosome 5A flanked by deletion breakpoints 0.68 and 0.78. This interval was shown to be homoeologous to a region of rice chromosome 3 that contains the flowering-time QTL Hd-6, previously mapped in a Nipponbare×Kasalath cross, and FLTQ1, a novel QTL identified by analysis of 78 F₃ families derived from a cross of ‘IR20’ב63–83’. Possible relationships between Vrn-A1 and rice QTL are discussed. Analysis of the chromosome 5A deletion lines showed evidence for a second, more proximal flowering-time effect located between deletion breakpoints 0.56 and 0.64. The proximal part of chromosome 5A is homoeologous to rice chromosome 9, on which two QTL were detected in the ‘IR20ב63–83’ cross. The possible relationship between these effects is also discussed. Received: 23 December 1997 / Accepted: 12 January 1998     

Cleavage of Host Cytokeratin-6 by Lysine-Specific Gingipain Induces Gingival Inflammation in Periodontitis Patients

Background/PurposeLysine-specific gingipain (Kgp) is a virulence factor secreted from Porphyromonas gingivalis (P. gingivalis), a major etiological bacterium of periodontal disease. Keratin intermediate filaments maintain the structural integrity of gingival epithelial cells, but are targeted by Kgp to produce a novel cytokeratin 6 fragment (K6F). We investigated the release of K6F and its induction of cytokine secretion.MethodsK6F present in the gingival crevicular fluid of periodontal disease patients and in gingipain-treated rat gingival epithelial cell culture supernatants was measured by matrix-assisted laser desorption/ionization time-of-flight mass spectrometer-based rapid quantitative peptide analysis using BLOTCHIP. K6F in gingival tissues was immunostained, and cytokeratin 6 protein was analyzed by immunofluorescence staining and flow cytometry. Activation of MAPK in gingival epithelial cells was evaluated by immunoblotting. ELISA was used to measure K6F and the cytokines release induced by K6F. Human gingival fibroblast migration was assessed using a Matrigel invasion chamber assay.ResultsWe identified K6F, corresponding to the C-terminus region of human cytokeratin 6 (amino acids 359–378), in the gingival crevicular fluid of periodontal disease patients and in the supernatant from gingival epithelial cells cultured with Kgp. K6F antigen was distributed from the basal to the spinous epithelial layers in gingivae from periodontal disease patients. Cytokeratin 6 on gingival epithelial cells was degraded by Kgp, but not by Arg-gingipain, P. gingivalis lipopolysaccharide or Actinobacillus actinomycetemcomitans lipopolysaccharide. K6F, but not a scrambled K6F peptide, induced human gingival fibroblast migration and secretion of interleukin (IL)-6, IL-8 and monocyte chemoattractant protein-1. These effects of K6F were mediated by activation of p38 MAPK and Jun N-terminal kinase, but not p42/44 MAPK or p-Akt.ConclusionKgp degrades gingival epithelial cell cytokeratin 6 to K6F that, on release, induces invasion and cytokine secretion by human gingival fibroblasts. Thus, Kgp may contribute to the development of periodontal disease.     

Characteristics of halorhodopsin-bacterioruberin complex from Natronomonas pharaonis membrane in the solubilized system

Halorhodopsin is a retinal protein with a seven-transmembrane helix and acts as an inward light-driven Cl(-) pump. In this study, structural state of the solubilized halorhodopsin (NpHR) from the biomembrane of mutant strain KM-1 of Natronomonas pharaonis in nonionic detergent was investigated. A gel filtration chromatography monitored absorbances at 280 and 504 nm corresponding to the protein and a lipid soluble pigment of bacterioruberin (BR), respectively, has clearly detected an oligomer formation of the NpHRs and a complex formation between the NpHR and BR in the solubilized system. A molar ratio of NpHR:BR in the solubilized complex was close to 1:1. Further SDS-PAGE analysis of the solubilized NpHR cross-linked by 1% glutaraldehyde has revealed that the NpHR forms homotrimer in detergent system. Although this trimeric structure was stable in the presence of NaCl, it was dissociated to the monomer by the heat treatment at 45 °C in the desalted condition. The same tendency has been reported in the case of trimeric NpHR expressed heterologously on the E. coli membrane, leading to a conclusion that the change of strength of the trimeric association dependent on the ion binding is a universal feature of the NpHR. Interestingly, the trimer dissociation on the NpHR was accompanied by the complete dissociation of the BR molecule from the protein, indicated that the cavity formed by the NpHR protomers in the trimeric conformation is important for tight binding of the BR. Because the binding affinity for Cl(-) and the resistance to hydroxylamine under light illumination showed only minor differences between the NpHR in the solubilized state and that on the biomembrane, the influences of solubilization to the tertiary structure and function of the protein are thought to be minor. This NpHR-BR complex in the solubilized system has a potential to be a good model system to investigate the intermolecular interaction between the membrane protein and lipid.     

Spread of X-chromosome inactivation into chromosome 15 is associated with Prader–Willi syndrome phenotype in a boy with a t(X;15)(p21.1;q11.2) translocation

X-chromosome inactivation (XCI) is an essential mechanism in females that compensates for the genome imbalance between females and males. It is known that XCI can spread into an autosome of patients with X;autosome translocations. The subject was a 5-year-old boy with Prader?CWilli syndrome (PWS)-like features including hypotonia, hypo-genitalism, hypo-pigmentation, and developmental delay. G-banding, fluorescent in situ hybridization, BrdU-incorporated replication, human androgen receptor gene locus assay, SNP microarrays, ChIP-on-chip assay, bisulfite sequencing, and real-time RT-PCR were performed. Cytogenetic analyses revealed that the karyotype was 46,XY,der(X)t(X;15)(p21.1;q11.2),?15. In the derivative chromosome, the X and half of the chromosome 15 segments showed late replication. The X segment was maternal, and the chromosome 15 region was paternal, indicating its post-zygotic origin. The two chromosome 15s had a biparental origin. The DNA methylation level was relatively high in the region proximal from the breakpoint, and the level decreased toward the middle of the chromosome 15 region; however, scattered areas of hypermethylation were found in the distal region. The promoter regions of the imprinted SNRPN and the non-imprinted OCA2 genes were completely and half methylated, respectively. However, no methylation was found in the adjacent imprinted gene UBE3A, which contained a lower density of LINE1 repeats. Our findings suggest that XCI spread into the paternal chromosome 15 led to the aberrant hypermethylation of SNRPN and OCA2 and their decreased expression, which contributes to the PWS-like features and hypo-pigmentation of the patient. To our knowledge, this is the first chromosome-wide methylation study in which the DNA methylation level is demonstrated in an autosome subject to XCI.