Assessment of the Annual Additional Effective Doses amongst Minamisoma Children during the Second Year after the Fukushima Daiichi Nuclear Power Plant Disaster

An assessment of the external and internal radiation exposure levels, which includes calculation of effective doses from chronic radiation exposure and assessment of long-term radiation-related health risks, has become mandatory for residents living near the nuclear power plant in Fukushima, Japan. Data for all primary and secondary children in Minamisoma who participated in both external and internal screening programs were employed to assess the annual additional effective dose acquired due to the Fukushima Daiichi nuclear power plant disaster. In total, 881 children took part in both internal and external radiation exposure screening programs between 1^st April 2012 to 31^st March 2013. The level of additional effective doses ranged from 0.025 to 3.49 mSv/year with the median of 0.70 mSv/year. While 99.7% of the children (n = 878) were not detected with internal contamination, 90.3% of the additional effective doses was the result of external radiation exposure. This finding is relatively consistent with the doses estimated by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The present study showed that the level of annual additional effective doses among children in Minamisoma has been low, even after the inter-individual differences were taken into account. The dose from internal radiation exposure was negligible presumably due to the success of contaminated food control.     

Tissue distribution of rat angiotensinogen mRNA and structural analysis of its heterogeneity

The tissue distribution and the structural heterogeneity of the rat angiotensinogen mRNA have been investigated with the aid of a previously cloned cDNA as well as a genomic DNA for rat angiotensinogen as analytical probes. The angiotensinogen mRNA is expressed not only in the liver but also in various tissues including the brain, kidney, adrenal gland, ovary, and lung. The relative levels of the mRNA in the above tissues have been estimated to be 3-4, 20-30 (for the next three tissues), and around 100 times less than that in the liver, respectively. The mRNAs in both hepatic and extrahepatic tissues are encoded by a single gene in the rat genome. At least four different size classes of the angiotensinogen mRNA that start with a single 5' terminus and differ only in the lengths of their 3'-untranslated regions have been identified, and these multiple mRNA species are most likely generated by using the polyadenylation signals AAUAAA and AUUAAA found 10-30 nucleotides upstream from the four polyadenylation sites. Because the structures of these multiple mRNA species do not vary among the tissues of the liver, brain, and kidney, angiotensinogen synthesized locally is structurally identical to that produced in the liver and may have some biological roles independent of the circulating angiotensinogen, mainly derived from the liver. In addition, the sequence of the 5'-flanking region of the angiotensinogen gene has been determined, and some features common to other steroid hormone-responsive genes have been discussed.     

Early nuclear events of in vitro fertilization in the domestic fowl (Gallus domesticus)

In vitro fertilization in the domestic fowl (Gallus domesticus) was investigated by observation of the early nuclear events. Ova retrieved from the fimbria following ovulation were inseminated in vitro with 10(6)-10(7) spermatozoa in Dulbecco's modified Eagle's medium (DMEM) for 10 min and then further incubated in DMEM + albumen for 1, 2, 3, or 4 hr. These eggs were histologically examined by epifluorescent microscopy after staining with 4',6'-diamidino-2-phenylindole (DAPI). Nuclei of spermatozoa at various stages of transformation were observed in the ova incubated for 1-3 hr. Close pairing of two pronuclei, presumed to be male and female juxtaposition, was detected in ova incubated for 4 hr. These data provide direct evidence for the in vitro fertilization of fowl eggs and suggested that the early process of in vitro fertilization is comparable to that of in vivo fertilization.     

The role of heavy-metal ATPases,HMAs, in zinc and cadmium transport in rice

The P_1B-type heavy metal ATPases (HMAs) are diverse in terms of tissue distribution, subcellular localization, and metal specificity. Functional studies of HMAs have shown that these transporters can be divided into two subgroups based on their metal-substrate specificity: a copper (Cu)/silver (Ag) group and a zinc (Zn)/cobalt (Co)/cadmium (Cd)/lead (Pb) group. Studies on Arabidopsis thaliana and metal hyperaccumulator plants indicate that HMAs play an important role in the translocation or detoxification of Zn and Cd in plants. Rice possesses nine HMA genes, of which OsHMA1–OsHMA3 belong to the Zn/Co/Cd/Pb subgroup. OsHMA2 plays an important role in root-to-shoot translocation of Zn and Cd, and participates in Zn and Cd transport to developing seeds in rice. OsHMA3 transports Cd and plays a role in the sequestration of Cd into vacuoles in root cells. Modification of the expression of these genes might be an effective approach for reducing the Cd concentration in rice grains.     

miR-146a Polymorphism (rs2910164) Predicts Colorectal Cancer Patients’ Susceptibility to Liver Metastasis

miR-146a plays important roles in cancer as it directly targets NUMB, an inhibitor of Notch signaling. miR-146a is reportedly regulated by a G>C polymorphism (SNP; rs2910164). This polymorphism affects various cancers, including colorectal cancer (CRC). However, the clinical significance of miR-146a polymorphism in CRC remains unclear. A total of 59 patients with CRC were divided into 2 groups: a CC/CG genotype (n = 32) and a GG genotype (n = 27), based on the miR-146a polymorphism. cDNA microarray analysis was performed using 59 clinical samples. Significantly enriched gene sets in each genotype were extracted using GSEA. We also investigated the association between miR-146a polymorphism and miR-146a, NUMB expression or migratory response in CRC cell lines. The CC/CG genotype was associated with significantly more synchronous liver metastasis (p = 0.007). A heat map of the two genotypes showed that the expression profiles were clearly stratified. GSEA indicated that Notch signaling and JAK/STAT3 signaling were significantly associated with the CC/CG genotype (p = 0.004 and p = 0.023, respectively). CRC cell lines with the pre-miR-146a/C revealed significantly higher miR-146a expression (p = 0.034) and higher NUMB expression and chemotactic activity. In CRC, miR-146a polymorphism is involved in liver metastasis. Identification of this polymorphism could be useful to identify patients with a high risk of liver metastasis in CRC.     

Light activates H2 15O flow in rice: Detailed monitoring using a positron-emitting tracer imaging system (PETIS)

Water (H₂ ¹⁵O) translocation from the roots to the top of rice plants ( Oryza saliva L. cv. Nipponbare) was visualized over time by a positron-emitting tracer imaging system (PETIS). H₂ ¹⁵O flow was activated 8 min after plants were exposed to bright light (1 500 μmol m⁻² s⁻¹). When the light was subsequently removed, the flow gradually slowed and completely stopped after 12 min. In plants exposed to low light (500 μmol m⁻² s⁻¹), H₂ ¹⁵O flow was activated more slowly, and a higher translocation rate of H₂ ¹⁵O was observed in the same low light at the end of the next dark period. NaCl (80 m M ) and methylmercury (1 m M ) directly suppressed absorption of H₂ ¹⁵O by the roots, while methionine sulfoximine (1 m M ), abscisic acid (10 μ M ) and carbonyl cyanide m -chlorophenylhydrazone (10 m M ) were transported to the leaves and enhanced stomatal closure, reducing H₂ ¹⁵O translocation.     

Synthesis and biological studies of 5-aminolevulinic acid-containing dendrimers for photodynamic therapy.

Using a convergent growth approach, a series of novel 5-aminolevulinic acid (ALA)-containing dendrimers have been synthesized. In these molecules, ALA residues are attached to the periphery by ester linkages, with amide bonds connecting the dendrons. Three first-generation dendrimers, bearing either 6 or 9 ALA residues, were synthesized by attachment of a tris(Boc-protected ALA)-containing wedge (1) to a di- or tripodent aromatic, or tripodent aliphatic core. Two second generation 18-ALA-containing dendrimers were also synthesized using a 3,3'-iminodipropionic acid spacer unit between wedge 1 and the aromatic core. These compounds differed only in the distance between the core and the linker unit. The Boc-protected dendrimers were deprotected using trifluoroacetic acid and isolated as their TFA salts. The potential of these ALA ester dendrimers as macromolecular prodrugs for photodynamic therapy has been demonstrated in the tumorigenic keratinocyte PAM 212 cell line.     

Effect of tea catechins on mitochondrial DNA 4977-bp deletions in human leucocytes

The catechins in green tea have antioxidative and antimutagenic effects. We examined the effect of green tea enriched with catechins on the presence of mitochondrial DNA (mtDNA) with a common 4977-bp deletion mutation (mtDNA4977) in human leucocytes. Ten healthy females [aged 20.80 +/- 1.03 years] drank 350 ml of catechin-rich tea daily after supper for 5 weeks. Blood samples were collected twice before, and twice after 5 weeks of consuming the tea. Deletions in mtDNA were analyzed using the nested polymerase chain reaction (PCR). We identified a common mtDNA4977 deletion in nine participants before drinking the tea. However, this mtDNA4977 deletion was not evident in leucocytes from most of the participants 5 weeks after drinking the tea. Catechins found in tea might contribute to the maintenance of health status by reducing damage to mtDNA and by maintaining the capacity of mtDNA for oxidative phosphorylation.     

Lectin histochemistry in rat thyroid tumours

The thyroid tumours and background goiterous and adenomatous lesions induced in rats with diisopropanolnitrosamine (DIPN) plus methylthiouracil (MTU), and regenerative thyroid tissues after wounding were studied by lectin histochemistry. Ten weeks after cessation of the carcinogen treatments, carcinomas invading the surrounding tissues and blood vessels (13/20) and papillary micronodules (11/20) were formed in the thyroid tissues. In general, the carcinoma lesion was solitary, and the papillary micronodules were multiple in a single thyroid gland. Among the lectins tested, Maclura pomifera (MPA) and Solanum tuberosum (STA) showed specific binding with both carcinoma and papillary micronodule lesions, but not with the background goiterous and adenomatous lesions and regenerative thyroid tissues. The former both lesions showed higher labelling indices with BUdR or 3H-thymidine and poorer thyroglobulin accumulation than the latters, thereby indicating their enhanced proliferative capability and depressed potency of cyto-differentiation. The common cytological and histochemical properties of carcinoma lesions and papillary micronodules allow us to regard the latter as pre-invading carcinoma lesions. The lectins MPA and STA may be, therefore, used as the specific markers of malignancy in rat thyroid carcinogenesis.