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1.  Radiosensitivity of pimonidazole-unlabelled intratumour quiescent cell population to γ-rays, accelerated carbon ion beams and boron neutron capture reaction 
The British Journal of Radiology  2013;86(1021):20120302.
To detect the radiosensitivity of intratumour quiescent (Q) cells unlabelled with pimonidazole to accelerated carbon ion beams and the boron neutron capture reaction (BNCR).
EL4 tumour-bearing C57BL/J mice received 5-bromo-29-deoxyuridine (BrdU) continuously to label all intratumour proliferating (P) cells. After the administration of pimonidazole, tumours were irradiated with c-rays, accelerated carbon ion beams or reactor neutron beams with the prior administration of a 10B-carrier. Responses of intratumour Q and total (P+Q) cell populations were assessed based on frequencies of micronucleation and apoptosis using immunofluorescence staining for BrdU. The response of pimonidazole-unlabelled tumour cells was assessed by means of apoptosis frequency using immunofluorescence staining for pimonidazole.
Following c-ray irradiation, the pimonidazole-unlabelled tumour cell fraction showed significantly enhanced radiosensitivity compared with the whole tumour cell fraction, more remarkably in the Q than total cell populations. However, a significantly greater decrease in radiosensitivity in the pimonidazole-unlabelled cell fraction, evaluated using a delayed assay or a decrease in radiation dose rate, was more clearly observed among the Q than total cells. These changes in radiosensitivity were suppressed following carbon ion beam and neutron beam-only irradiaton. In the BNCR, the use of a 10B-carrier, especially L-para-boronophenylalanine-10B, enhanced the sensitivity of the pimonidazole-unlabelled cells more clearly in the Q than total cells.
The radiosensitivity of the pimonidazole-unlabelled cell fraction depends on the quality of radiation delivered and characteristics of the 10B-carrier used in the BNCR.
Advances in knowledge
The pimonidazole-unlabelled subfraction of Q tumour cells may be a critical target in tumour control.
PMCID: PMC3615400  PMID: 23255546
2.  Effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy 
The British Journal of Radiology  2012;85(1011):249-258.
To evaluate the effects of employing a 10B-carrier and manipulating intratumour hypoxia on local tumour response and lung metastatic potential in boron neutron capture therapy (BNCT) by measuring the response of intratumour quiescent (Q) cells.
B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2′-deoxyuridine (BrdU) to label all proliferating (P) cells. The tumours received reactor thermal neutron beam irradiation following the administration of a 10B-carrier [L-para-boronophenylalanine-10B (BPA) or sodium mercaptoundecahydrododecaborate-10B (BSH)] in combination with an acute hypoxia-releasing agent (nicotinamide) or mild temperature hyperthermia (MTH). Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (P+Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In other tumour-bearing mice, macroscopic lung metastases were enumerated 17 days after irradiation.
BPA-BNCT increased the sensitivity of the total tumour cell population more than BSH-BNCT. However, the sensitivity of Q cells treated with BPA was lower than that of BSH-treated Q cells. With or without a 10B–carrier, MTH enhanced the sensitivity of the Q cell population. Without irradiation, nicotinamide treatment decreased the number of lung metastases. With irradiation, BPA-BNCT, especially in combination with nicotinamide treatment, showed the potential to reduce the number of metastases more than BSH-BNCT.
BSH-BNCT in combination with MTH improves local tumour control, while BPA-BNCT in combination with nicotinamide may reduce the number of lung metastases.
PMCID: PMC3473983  PMID: 22391496
3.  Reducing intratumour acute hypoxia through bevacizumab treatment, referring to the response of quiescent tumour cells and metastatic potential 
The British Journal of Radiology  2011;84(1008):1131-1138.
The aim was to evaluate the influence of bevacizumab on intratumour oxygenation status and lung metastasis following radiotherapy, with specific reference to the response of quiescent (Q) cell populations within irradiated tumours.
B16-BL6 melanoma tumour-bearing C57BL/6 mice were continuously given 5-bromo-2-deoxyuridine (BrdU) to label all proliferating (P) cells. They received γ-ray irradiation following treatment with the acute hypoxia-releasing agent nicotinamide or local mild temperature hyperthermia (MTH) with or without the administration of bevacizumab under aerobic conditions or totally hypoxic conditions, achieved by clamping the proximal end of the tumours. Immediately after the irradiation, cells from some tumours were isolated and incubated with a cytokinesis blocker. The responses of the Q and total (P + Q) cell populations were assessed based on the frequency of micronuclei using immunofluorescence staining for BrdU. In the other tumour-bearing mice, macroscopic lung metastases were enumerated 17 days after irradiation.
3 days after bevacizumab administration, acute hypoxia-rich total cell population in the tumour showed a remarkably enhanced radiosensitivity to γ-rays, and the hypoxic fraction (HF) was reduced, even after MTH treatment. However, the hypoxic fraction was not reduced after nicotinamide treatment. With or without γ-ray irradiation, bevacizumab administration showed some potential to reduce the number of lung metastases as well as nicotinamide treatment.
Bevacizumab has the potential to reduce perfusion-limited acute hypoxia and some potential to cause a decrease in the number of lung metastases as well as nicotinamide.
PMCID: PMC3473837  PMID: 21586505
4.  Circulating Tumor Cells as a Potential Biomarker in Selecting Patients for Pulmonary Metastasectomy from Colorectal Cancer: Report of a Case 
Case Reports in Oncology  2012;5(3):542-545.
Pulmonary metastasectomy is indicated for selected patients with metastatic colorectal cancer. A 43-year-old woman presented with solitary pulmonary metastasis from descending colon cancer and pulmonary metastasectomy was performed because of absence of any other active metastasis as well as normal serum carcinoembryonic antigen value. However, she died due to early development of nodal and bone metastases within 6 months after thoracotomy. The presence of circulating tumor cells (CTCs) in the peripheral blood (6 CTCs/7.5 ml) was the only factor to predict such a poor prognosis, suggesting that the CTC test is useful in selecting patients for pulmonary metastasectomy.
PMCID: PMC3492968  PMID: 23139669
Circulating tumor cells; Colorectal cancer; Pulmonary metastasectomy
5.  Economic recession and health inequalities in Japan: analysis with a national sample, 1986–2001 
Little is known about whether economic crises widen health inequalities. Japan experienced more than 10 years of economic recession beginning in the 1990s. The question of whether socioeconomic-based inequality in self-rated health widened after the economic crisis was examined.
Design, setting and participants
Repeated cross-sectional survey design. Two pooled datasets from 1986 and 1989 and from 1998 and 2001 were analysed separately, and temporal change was examined. The study took place in Japan among the working-age population (20–60 years old). The two surveys consisted of 168 801 and 150 016 people, respectively, with about an 80% response rate.
The absolute percentages of people reporting poor health declined across all socioeconomic statuses following the crisis. However, after controlling for confounding factors, the odds ratio (OR) for poor self-rated health (95% confidence intervals) among middle-class non-manual workers (clerical/sales/service workers) compared with the highest class workers (managers/administrators) was 1.02 (0.92 to 1.14) before the crisis but increased to 1.14 (1.02 to 1.29) after the crisis (p for temporal change = 0.02). The association was stronger among males. The adjusted ORs among professional workers and young female homemakers also marginally increased over time. Unemployed people were twice as likely to report poor health compared with the highest class workers throughout the period. Self-rated health of people with middle to higher incomes deteriorated in relative terms following the crisis compared with that of lower income people.
Self-rated health improved in absolute terms for all occupational groups even after the economic recession. However, the relative disparity increased between the top and middle occupational groups in men.
PMCID: PMC2785845  PMID: 18791043
6.  Relative deprivation and incident functional disability among older Japanese women and men: prospective cohort study 
A prospective observational study was conducted to test the hypothesis that relative deprivation was associated with incident physical or cognitive disability, independent of absolute income.
Study subjects consist of 9463 non-disabled people aged 65+ years in the Aichi Gerontological Evaluation Study (AGES), Aichi prefecture, Japan. Baseline mail-in survey in 2003 gathered information on income, educational attainment, lifestyle factors (smoking, alcohol consumption and health check-up) and healthcare utilisation. Three-year incidence of disability was assessed through public long-term care insurance databases and resident registry.
A total of 7673 subjects (81%) with complete information were analysed. Our measure of relative deprivation was the Yitzhaki index across eight reference groups, which calculates the deprivation suffered by each individual as a function of the aggregate income shortfall for each person relative to everyone else with higher incomes in that person’s reference group. Cox regression demonstrated that, after controlling for sociodemographic factors (including absolute income), the hazard ratio (and 95% confidence intervals) of incident physical/cognitive disability per one standard deviation increase in relative deprivation ranged from 1.13 (0.99 to 1.29) to 1.15 (1.01 to 1.31) in men and from 1.11 (0.94 to 1.31) to 1.18 (1.00 to 1.39) in women, depending on the definition of the reference group. Additional adjustment for lifestyle factors attenuated the hazard ratios to statistical non-significance.
Relative deprivation may be a mechanism underlying the link between income inequality and disability in older age, at least among men. Lifestyle factors in part explain the association between relative deprivation and incident disability.
PMCID: PMC2677290  PMID: 19218252
9.  Defective PEX gene products correlate with the protein import, biochemical abnormalities, and phenotypic heterogeneity in peroxisome biogenesis disorders 
Journal of Medical Genetics  1999;36(10):779-781.
Peroxisome biogenesis disorders (PBD) comprise three phenotypes including Zellweger syndrome (ZS) (the most severe), neonatal adrenoleucodystrophy, and infantile Refsum disease (IRD) (the most mild), and can be classified into at least 12 genetic complementation groups, which are not predictive of the phenotypes. Several pathogenic genes for PBD groups have been identified, but the relationship between the defective gene products and phenotypic heterogeneity has remained unclear. We identified a mutation in the PEX2 gene in an IRD patient with compound heterozygosity for a missense mutation and the known nonsense mutation detected in ZS patients. In transfection experiments using the peroxisome deficient CHO mutant, Z65 with a nonsense mutation in the PEX2 gene, we noted the E55K mutation had mosaic activities of peroxisomal protein import machinery and residual activities of peroxisomal functions, including dihydroxyacetone phosphate acyltransferase and β oxidation of very long chain fatty acids. The nonsense mutation severely affects these peroxisomal functions as well as the protein import. These data suggest that allelic heterogeneity of the PEX gene affects the peroxisomal protein import and functions and regulates the clinical severity in PBD.

Keywords: Zellweger syndrome; infantile Refsum disease; PEX gene; mosaic
PMCID: PMC1734244  PMID: 10528859
10.  Molecular basis of selective IgG2 deficiency. The mutated membrane-bound form of gamma2 heavy chain caused complete IGG2 deficiency in two Japanese siblings. 
Journal of Clinical Investigation  1998;101(3):677-681.
Patients with IgG2 deficiency have recurrent sinopulmonary infections caused by Pneumococcus and Hemophilus. Hereditary and selective IgG2 deficiency was suspected in two Japanese siblings whose serum IgG2 levels were under detection limits, while other serum levels of immunoglobulin subclasses were within normal ranges. Expression level of spontaneous germline Cgamma2 transcript was normal, but that of the spontaneous mature Cgamma2 transcript was greatly decreased in the patients' PBMCs, suggesting the presence of a defect at or after the class switch to Cgamma2. We sequenced the Cgamma2 gene region, and in both patients a homozygous one-base insertion (1793insG) was present in exon 4 of the Cgamma2 gene, just upstream from the alternative splice site for M exons. The mutant membrane-bound gamma2 heavy chain loses the transmembrane domain and the evolutionarily conserved cytoplasmic domain. Considering several lines of evidence showing that intact expression of the membrane-bound heavy chain is essential for a normal response of B cells and production of secreted immunoglobulin in mice, we concluded that 1793insG is responsible for selective and complete IgG2 deficiency in these two siblings. This is the first documentation of a mutation in human selective IgG2 deficiency.
PMCID: PMC508612  PMID: 9449702
11.  Suppression of methicillin resistance in a mecA-containing pre-methicillin-resistant Staphylococcus aureus strain is caused by the mecI-mediated repression of PBP 2' production. 
Antimicrobial Agents and Chemotherapy  1996;40(12):2680-2685.
The mechanism of methicillin susceptibility was studied in Staphylococcus aureus N315P, a pre-methicillin-resistant S. aureus strain that is susceptible to methicillin, despite the presence of mecA in the chromosome. In the presence of mec regulator genes mecI and mecR1, transcription of the mecA gene was not inducible by the addition of methicillin to the culture medium. Inactivation of the mecI gene function by replacing it with tetL made N315P express heterogeneous-type methicillin resistance. The subclone, in which the mecI gene was replaced, subclone P delta I, produced 12 times greater amounts of mecA gene transcripts and 8.5 times more PBP 2' protein than N315P. These data indicate that the mecI gene-encoded repression of mecA gene transcription is responsible for the apparent methicillin susceptibility phenotype of pre-methicillin-resistant S. aureus N315P.
PMCID: PMC163603  PMID: 9124822
12.  Hibernation-associated gene regulation of plasma proteins with a collagen-like domain in mammalian hibernators. 
Molecular and Cellular Biology  1993;13(3):1516-1521.
In mammals, hibernation is expressed by only a limited number of species, and the molecular mechanisms underlying hibernation are not well understood. Recently, we have found plasma proteins which disappear from blood specifically during hibernation in a mammalian hibernator, the chipmunk. Here, we report the cDNA cloning of these chipmunk hibernation-related proteins, HP-20, -25, and -27, and analyses of their expression. All three proteins contain a collagen-like domain near the N terminus and are highly homologous to each other. Their mRNAs were detected only in liver in nonhibernating chipmunks, and in hibernating chipmunks, the amounts were reduced to less than 1/10 of those in nonhibernating chipmunks, indicating that HP-20, -25, and -27 mRNA expression is regulated similarly in association with hibernation. Southern blot analyses of the squirrel family with each of chipmunk HP-20, -25, and -27 cDNA revealed that a nonhibernating species (tree squirrel) as well as another hibernating species (ground squirrel) retained the corresponding genes. However, their transcripts were detected only with the hibernating species, and in hibernating ground squirrels, their levels were greatly reduced compared with those in nonhibernating animals, as were the cases with the chipmunk. These observations are the first line of evidence for occurrence of hibernation-associated gene regulation. The results would indicate the commitment of HP-20, -25, and -27 to hibernation and support the idea that genetic controls are involved in mammalian hibernation.
PMCID: PMC359463  PMID: 8441393
13.  Cord blood lymphocyte responses to food antigens for the prediction of allergic disorders. 
Archives of Disease in Childhood  1992;67(8):1003-1007.
Proliferative responses of cord blood lymphocytes (CBLs) to food antigens and cord blood IgE concentrations were measured in 37 full term newborn infants for the prediction of allergic disorders. In these 37 infants who were followed up for two years, allergic history of the family was found in four (sensitivity 57.1%) and cord blood IgE concentrations were greater than 0.5 IU/ml in three (sensitivity 42.9%) of seven infants who developed allergic disorders. When CBLs were stimulated twice by ovalbumin or bovine serum albumin, the value of the stimulation index in proliferative responses of CBLs to ovalbumin or bovine serum albumin was greater than 1.5 in six (sensitivity 85.7%) of seven infants who developed allergic disorders. The specificity of the responses of CBLs in the prediction of the development of allergic disorders was 93.3%. The proliferative responses of CBLs to food antigens were useful in the prediction of not only development of allergic disorders but also offending allergens. These observations provide further evidence that sensitisation is occurring in utero. This would appear to be increasingly important in the genesis of early atopic problems. As our follow up is only two years, in utero sensitisation is a prediction for the early development of atopic disease but only longer follow up will show whether this holds good for allergic disorders at any age.
PMCID: PMC1793573  PMID: 1520001
15.  Interleukin-2 production of lymphocytes in food sensitive atopic dermatitis. 
Archives of Disease in Childhood  1992;67(3):280-284.
The proliferative responses of peripheral blood mononuclear cells (PBMC) to food antigens in 22 patients with food sensitive atopic dermatitis were significantly higher than the responses of healthy children and food sensitive children with immediate symptoms. Moreover, the activity of interleukin-2 (IL-2) in supernatants of food antigen stimulated PBMC cultures from patients with atopic dermatitis was significantly higher than that in healthy children and food sensitive children with immediate symptoms. The activity of IL-2 in culture supernatants of separated cell populations stimulated with food antigens from patients with atopic dermatitis and healthy children was investigated. The activity of IL-2 in supernatants of food antigen stimulated T cell cultures could be detected in patients with atopic dermatitis but not in healthy children. These results suggest that the increased IL-2 production after food antigen stimulation is due to increased T cell activity in food sensitive atopic dermatitis.
PMCID: PMC1793662  PMID: 1575549
16.  Parameters that govern the regulation of immunoglobulin delta heavy-chain gene expression. 
Molecular and Cellular Biology  1990;10(10):5340-5348.
The mu and delta immunoglobulin heavy-chain genes comprise a complex transcriptional unit in which a single mRNA precursor gives rise to mu- and delta-specific transcripts. During the immature B-cell stage, posttranscriptional processing events involving alternate splicing and cleavage-polyadenylation site selection give rise to mu- but not delta-encoding transcripts. In terminally differentiated B cells, delta mRNA is not synthesized because of a transcription termination event occurring upstream of the delta-gene locus. In an attempt to gain insight into the respective contributions of alternate splicing and cleavage-polyadenylation in the control of delta mRNA synthesis, we have constructed a set of plasmids in which membrane mu (mu m)-delta intergenic sequences containing the mu m poly(A) site but differing in splicing capacity were inserted in between a VH and delta gene. The mu m-delta insertion vectors were transfected into a B lymphoma line representative of an immature stage, and proximal mu m poly(A) site usage and delta mRNA synthesis were assessed. To determine unequivocally whether the mu m-delta intergenic region can regulate termination, the insertion vectors were also transfected into a B myeloma line, and transcription through the region was measured. In immature B-cell transfectants, splicing site selection was found to have a key role in determining poly(A) site utilization and concomitant delta mRNA expression. Mature delta mRNA synthesis was blocked by an upstream cleavage-polyadenylation event only when the proximal poly(A) site was associated with appropriate splicing signals. Furthermore, in vitro transcription assays revealed that the mu m-delta intergenic region is sufficient to regulate transcription termination within a 1,2430-base-pair region containing the mu m poly(A) site in myeloma transfectants. The mu m-delta insertion vectors provide an excellent model system for studying the regulatory aspects of this transcription termination event.
PMCID: PMC361229  PMID: 2118995
17.  Genome-wide association study identifies a potent locus associated with human opioid sensitivity 
Molecular Psychiatry  2012;19(1):55-62.
Opioids, such as morphine and fentanyl, are widely used as effective analgesics for the treatment of acute and chronic pain. In addition, the opioid system has a key role in the rewarding effects of morphine, ethanol, cocaine and various other drugs. Although opioid sensitivity is well known to vary widely among individual subjects, several candidate genetic polymorphisms reported so far are not sufficient for fully understanding the wide range of interindividual differences in human opioid sensitivity. By conducting a multistage genome-wide association study (GWAS) in healthy subjects, we found that genetic polymorphisms within a linkage disequilibrium block that spans 2q33.3–2q34 were strongly associated with the requirements for postoperative opioid analgesics after painful cosmetic surgery. The C allele of the best candidate single-nucleotide polymorphism (SNP), rs2952768, was associated with more analgesic requirements, and consistent results were obtained in patients who underwent abdominal surgery. In addition, carriers of the C allele in this SNP exhibited less vulnerability to severe drug dependence in patients with methamphetamine dependence, alcohol dependence, and eating disorders and a lower ‘Reward Dependence' score on a personality questionnaire in healthy subjects. Furthermore, the C/C genotype of this SNP was significantly associated with the elevated expression of a neighboring gene, CREB1. These results show that SNPs in this locus are the most potent genetic factors associated with human opioid sensitivity known to date, affecting both the efficacy of opioid analgesics and liability to severe substance dependence. Our findings provide valuable information for the personalized treatment of pain and drug dependence.
PMCID: PMC3873034  PMID: 23183491
analgesia; dependence; opioids; pharmacogenetics
18.  The effect of (2'-5') and (3'-5') phosphodiester linkages on conformational and stacking properties of cytidylyl-cytidine in aqueous solution. 
Nucleic Acids Research  1976;3(10):2549-2562.
Conformational properties of (2'-5') and (3'-5') CpC have been determined by proton magnetic resonance spectroscopy at 220 MHz. The ribose ring structures are predominantly 3E with the exception of the ring from the 2'-phosphate fragment of C(2'-5')pC which exhibits an 2E pucker. Bases are oriented anti with respect to the ribose and the conformations about C4'-C5', C5'-O5', C3'-O3' (C2'-O2') are gg, g'g', and g+ in equilibrium g-, respectively. The dimers exist as mixtures of stacked (g+g+ and g-g- about the P-O(C) bonds) and unstacked species at 20 degrees C. Stacking is estimated to be 35% in both dimers.
PMCID: PMC343112  PMID: 995643
19.  X-ray structure of cytidine-5'-O-dimethylphosphate. Novel stacking between the ribosyl O(2') hydroxyl oxygen atom and the base. 
Nucleic Acids Research  1984;12(17):6813-6825.
The anionic oxygen atoms of the phosphodiester backbone of RNA and DNA are particularly susceptible to esterification by many mutagenic and carcinogenic alkylating agents. To better understand the geometric, electronic and conformational properties of the alkylated sugar phosphate moiety, the X-ray structure of the phosphotriesterified nucleotide, cytidine-5'-O-dimethylphosphate (C11H18N3O8P), was undertaken. The compound crystallizes in the monoclinic space group P2, with unit cell parameters of a = 5.741(2), b = 11.625(1), c = 11.425(1)A, beta = 94.43(2) degrees. The structure was solved by direct methods and refined by block-diagonal least-squares technique to an R index of 0.034 (Rw = 0.046). The D-ribofuranosyl ring is in the 3T2 twist conformation (P = 13.1(2) degrees, tau m = 36.7(2) degrees) and the conformation about the C(1')-N(1) glycosyl bond is anti (XCN = 8.3(2) degrees). The four P-O bond lengths are significantly shorter than those of the nonalkylated nucleotides. The three sets of phosphodiester linkages, (omega 'A, omega A), (omega 'B, omega B) and (omega 'C, omega C), take the (g-,t), (t,g) and (g-,t) conformations, respectively. There is no base-base or alkyl-base stacking, however, a novel intermolecular stacking is found between the ribosyl O(2') hydroxyl oxygen atom and a neighboring pyrimidine ring. This hydroxyl-base stacking interaction may have implications in the stabilization of the tertiary and quarternary structure of ribonucleic acids and nucleic acid-protein complexes.
PMCID: PMC320118  PMID: 6548306

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