Application of Prussian blue nanoparticles for the radioactive Cs decontamination in Fukushima region.

Cs decontamination efficiencies of the composites of iron hexacyanoferrate nanoparticles were investigated in comparison with commercial Prussian blue and natural zeolite. In pure water solution, the adsorption rate varied with sizes. In ash extract, where Cs adsorbing ability of zeolite was sharply dropped due to its poor selectivity, the impact of coexisting ions was negligible for FeHCF. FeHCF-n11, having the finest primary and secondary particle size, resulted the highest distribution coefficient, which was comparable to the high efficiency analogues, CoHCF or NiHCF. This observation suggested the possibility of preparing the high performance FeHCF by particle size and composition adjustment. FeHCF nanoparticle in bead form was tested for the removal of radioactive Cs in pilot scale. Due to larger secondary particle size, pronounced effect of solution temperature on the Cs adsorption kinetics on FeHCF bead was observed. Adjusting the mass of the adsorbent for the given solution temperature is recommended for achieving high decontamination rate.

Monitoring low-radioactivity caesium in Fukushima waters.

A new monitoring system has been established to assess low-level radioactive caesium in Fukushima waters directly using caesium adsorbents: plastic containers, U8 containers, and a germanium (Ge) detector container packed with nanoparticle-Prussian blue (PB) immobilized on a polymer. The results show that the calibration coefficient for a flow rate of 0.3 L min(-1) was 1.27 in Fukushima waters for germanium semiconductor scintillations related to (133)Cs concentrations and radioactive caesium amounts.

Electrochemical gene sensor arrays prepared using non-contact nanoliter array spotting of gene probes.

A capillary-based pitch-variable array spotter, designed to dispense solutions in nanoliter volumes with high precision and density, was used to immobilize gene probes on a microelectrode array chip. Small volumes of the probe solutions were dispensed onto the microelectrodes, without any physical contact between the capillary ends and the electrode surfaces, to fabricate an electrochemical gene sensor array chip. The fabricated gene sensor array chip showed sequence-selective responses, expressed on a pseudocolor scale, to a target DNA sample. It was demonstrated that this dispensing technique provides integrated sensor array chips by dispensing small volumes of solutions of synthesized functional gene probes onto microelectrode array chips, a process not possible with conventional dispensing techniques.

Allelic loss analysis of tumor suppressor genes regardless of heterozygosity: von Hippel-Lindau gene loss in renal cell carcinoma.

PURPOSE: VHL, the von Hippel-Lindau tumor suppressor gene, has no microsatellites, but rather single nucleotide polymorphisms inside the gene. However, their low heterozygosity is unfavorable for loss of heterozygosity analysis. We examined whether our modified single nucleotide polymorphism genotyping method would be useful for allelic loss analysis of the VHL gene in heterozygous and homozygous genotypes of sporadic renal cell carcinoma. MATERIALS AND METHODS: Genomic DNA was extracted from tumor and nontumor tissues in 35 cases of sporadic renal cell carcinoma. The single nucleotide polymorphism (rs1642742), G or A containing region of the VHL gene was amplified from sample DNA and subjected to primer extension reaction with fluorescent dideoxynucleotide triphosphate. Template directed incorporation of fluorescent dideoxyguanosine triphosphate or dideoxyadenosine triphosphate was quantitatively analyzed and the A/G (G/A) signal ratio was compared between tumor and nontumor tissues. RESULTS: We confirmed quantitative template directed incorporation of dideoxyguanosine triphosphate or dideoxyadenosine triphosphate using model templates with various ratios of DNA from the 2 genotypes AA and GG. In 20 heterozygous cases of renal cell carcinoma the A/G signal ratio was significantly differentiated between tumor and nontumor in 9 loss of heterozygosity positive cases but not in 11 loss of heterozygosity negative cases. A total of 15 homozygous renal cell carcinoma cases were tested by adding homozygous control DNA of a different genotype before analysis. Eight of the 15 cases showed a significantly lower signal ratio in tumor than in nontumor, whereas the other 7 showed no significant difference. CONCLUSIONS: Our modified single nucleotide polymorphism genotyping is broadly applicable to allelic loss analysis of tumor suppressor genes in heterozygous and homozygous tumors.

Prostate cancer with supraclavicular lymphadenopathy and bulky abdominal tumor.

A 73-year-old man with suspected lymphoproliferative disorder was introduced to our hospital. The patient demonstrated palpable hard masses in the abdomen. Enhanced computed tomography of the abdomen and pelvis revealed a bulky mass of para-aortic lymph nodes. Biopsy of left-sided supraclavicular lymph nodes revealed metastatic adenocarcinoma. Serum tumor markers were examined, revealing prostate-specific antigen (PSA) levels of 3,354.0 ng/ml. Rectal examinations revealed a stony-hard prostatic mass. Biopsy of the prostate disclosed poorly to moderately differentiated adenocarcinoma. Although metastases to the supraclavicular lymph nodes are rare in prostate cancer, it should be distinguished from malignant lymphoma and other malignancies.