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Naoko Watanabe

Publications and source records attributed to Naoko Watanabe.

At least 37 records · Page 2Linked to original sources
PubMed2004

Gene expression in the elicitation phase of guinea pig DTH and CHS reactions.

Delayed-type hypersensitivity (DTH) reactions are divided into classical DTH induced by protein antigens and contact hypersensitivity (CHS) induced by haptens. It has been reported that different cytokines and T cell subsets are involved in the induction of each DTH reaction. We previously isolated many genes whose expression is elevated during elicitation of skin DTH reaction in guinea pigs. In this study, we focused on the expression of tryptophanyl-tRNA synthetase (WRS), ferritin heavy chain and major histocompatibility complex (MHC) class II genes to investigate the different regulatory mechanisms in classical DTH and CHS. Furthermore, the expression of various cytokines and chemokines was examined. WRS expression in classical DTH was higher than that in CHS, and the expression of interferon-gamma but not that of transforming growth factor-beta showed similar patterns. MHC class II mRNA increased only in classical DTH. The differential expression of WRS and MHC class II genes in classical DTH might be caused by the differential expression of interferon-gamma and/or the involvement of CD4(+) T cells in classical DTH, respectively. In contrast, the expression of ferritin heavy chain and interleukin-1beta was elevated in CHS, and also by treatment with dinitrochlorobenzene in unsensitized guinea pigs, and expression of both was correlated.

Animals↗
PubMed2004

Ischemic preconditioning protects hepatocytes via reactive oxygen species derived from Kupffer cells in rats.

BACKGROUND AND AIMS: Hepatic ischemic preconditioning decreases sinusoidal endothelial cell injury and Kupffer cell activation after cold ischemia/reperfusion, leading to improved survival of liver transplant recipients in rats. Ischemic preconditioning also protects livers against warm ischemia/reperfusion injury, in which hepatocyte injury is remarkable. We aimed to determine whether ischemic preconditioning directly protects hepatocytes and to elucidate its mechanisms. METHODS: Rats were injected with gadolinium chloride to deplete Kupffer cells or with N -acetyl- l -cysteine, superoxide dismutase, or catalase to scavenge reactive oxygen species. Livers were then preconditioned by 10 minutes of ischemia and 10 minutes of reperfusion. Subsequently, livers were subjected to 40 minutes of warm ischemia and 60 minutes of reperfusion in vivo or in a liver perfusion system. In other rats, livers were preconditioned by H(2)O(2) perfusion instead of ischemia. In the other experiments, livers were perfused with nitro blue tetrazolium to detect reactive oxygen species formation. RESULTS: Ischemic preconditioning decreased injury in hepatocytes, but not in sinusoidal endothelial cells. Kupffer cell depletion itself did not change hepatocyte injury after ischemia/reperfusion, indicating no contribution of Kupffer cells to ischemia/reperfusion injury. However, Kupffer cell depletion reversed hepatoprotection by ischemic preconditioning. Reactive oxygen species formation occurred in Kupffer cells after ischemic preconditioning. Scavenging of reactive oxygen species reversed the effect of ischemic preconditioning, and H(2)O(2) preconditioning mimicked ischemic preconditioning. CONCLUSIONS: Ischemic preconditioning directly protected hepatocytes after warm ischemia/reperfusion, which is not via suppression of changes in sinusoidal cells as in cold ischemia/reperfusion injury. This hepatocyte protection was mediated by reactive oxygen species produced by Kupffer cells.

Acetylcysteine↗
PubMed2004

Frequent hypomethylation in multiple promoter CpG islands is associated with global hypomethylation, but not with frequent promoter hypermethylation.

Hypomethylation of the global genome, considered to be composed mainly of repetitive sequences, is consistently observed in cancers, and aberrant hypo- and hypermethylation of CpG islands (CGIs) in promoter regions are also observed. Since methylation alterations in unique promoter sequences and in other genomic regions have distinct consequences, we analyzed the relationship between the global hypomethylation and the hypomethylation of unique promoter CGIs using human gastric cancers. Seven of ten gastric cancer cell lines showed marked decreases in 5-methylcytosine content, which correlated with hypomethylation of the LINE1 repetitive sequence. Six of the seven cell lines showed hypomethylation in five or all of the six normally methylated CGIs in promoter regions of six genes, and this was associated with induction of aberrant expression. The remaining three cell lines without global hypomethylation showed promoter hypomethylation in one or none of the six CGIs. Frequent promoter hypomethylation, however, did not correlate with frequent promoter hypermethylation. In primary gastric cancers too, global hypomethylation was associated with hypomethylation of LINE1 repetitive sequence and promoter hypomethylation. Of 93 gastric cancers, 33 cancers with frequent promoter hypomethylation and 27 cancers with frequent promoter hypermethylation constituted different groups. These findings represent experimental evidence that frequent hypomethylation of normally methylated promoter CGIs is associated with global hypomethylation, and that these hypomethylations occur independently of frequent promoter CGI hypermethylation.

5-Methylcytosine↗
PubMed2004

Successful treatment of mu-heavy chain disease with fludarabine monophosphate: a case report.

Heavy chain diseases (HCD) are monoclonal lymphoproliferative disorders of B-cells characterized by the synthesis of truncated heavy chains without associated light chains. In patients with mu-HCD, which is a very rare form of HCD, neoplastic cells produce immunoglobulin M heavy chain. The prognosis for patients with mu-HCD is poor, and there is no specific treatment for mu-HCD. In this report, we present a patient with mu-HCD accompanied by splenomegaly and thrombocytopenia. We treated this patient with the fludarabine monophosphate therapy we use for patients with B-cell chronic lymphocytic leukemia. After 5 courses of fludarabine monophosphate treatment, the splenomegaly and thrombocytopenia improved. Fludarabine monophosphate therapy may be a new strategy to improve the prognosis of patients with mu-HCD.

Antimetabolites, Antineoplastic↗
PubMed2004

[Severe hyponatremia with consciousness disturbance caused by hydroxyurea in a patient with chronic myeloid leukemia].

A 79-year-old man was admitted because of consciousness disturbance on August 9, 2002. He had been diagnosed as having chronic myeloid leukemia in 1999, and since then, he had continued to take hydroxyurea (1500 mg/day) orally. On admission, his serum sodium concentration was as low as 119 mEq/L, while urinary sodium excretion was high. Based on the blood picture and lack of hepatosplenomegaly, we considered that the leukemia was still in the chronic phase. Because of normal blood level of the antidiuretic hormone (ADH) concentration and sufficient urine volume, the syndrome of inappropriate ADH secretion (SIADH) was unlikely, and sodium-losing nephropathy was suspected. After discontinuation of hydroxyurea, the urinary sodium excretion decreased and the patient's consciousness became clear concomitantly with improvement in the serum Na level. This patient appears to be the first case of hyponatremia caused by hydroxyurea.

Aged↗
PubMed2004

[Pleural involvement in the course of chronic myelomonocytic leukemia and the development of multiple colonic perforation due to leukemic infiltration in the acute leukemia phase].

A 68-year-old man with chronic myelomonocytic leukemia (CMML) was initially treated with hydroxyurea with subsequent stable disease. In the time course, he developed bilateral pleuritis accompanied by leukocytosis and spiking fever. Cytologic analysis of the pleural effusion revealed abundant mature granulocytes and monocytes. He was treated with intravenous or oral etoposide with consequent resolution of the pleuritis, indicating the pleural involvement of CMML. Three months later, he developed hepatomegaly and became febrile. One month thereafter, the CMML transformed to acute myeloid leukemia, and the patient developed massive bloody stools associated with epigastric pain and leukocytosis. A gastrofiberscopic examination showed multiple bleeding gastric ulcers. The bleeding ulcers were treated with the clipping procedure; however, the bloody stools continued. Although intravenous etoposide was effective for the leukocytosis and hepatomegaly, the treatment did not improve the bloody stools. The patient finally died of panperitonitis. The autopsy showed multiple ulcers of the transverse colon, some of which were perforated. Microscopically, the ulcerated areas were densely infiltrated with leukemic cells predominantly consisting of immature monocytes and granulocytes. This patient may be the first reported case of CMML complicated by colonic perforation due to leukemic infiltration.

Aged↗
PubMed2004

Effects of 17beta-estradiol on survival, growth, sexual development and molting cycles of the marine crustacean mysid shrimp, Americamysis bahia.

A 14-day partial life-cycle test was performed to assess the effects of 17beta-estradiol (E2) on the survival, growth, sexual development and molting cycles of a marine crustacean mysid shrimp (Americamysis bahia). Seven-day-old mysids were exposed to the nominal E2 concentrations of 31.3, 62.5, 125, 250 and 500 microg/l for 14 days. The total length and the body weight of mysids significantly decreased relative to the controls when exposed to 62.5, 250 and 500 microg/l E2 for 14 days. Moreover, the carapace length significantly decreased in the 500 microg/l E2 treatment groups. No significant differences were observed in sex ratio with the appearance of secondary sex characteristics in the all treatment groups including the control and solvent control groups. However, the percentage of females with eggs in the oviduct or brood sac decreased significantly in mysids treated with E2 at 62.5, 125, 250 and 500 microg/l. The cumulative total number of molting cycles when exposed to E2 for 14 days significantly decreased in the treatment groups at 500 microg/l relative to the controls. These results suggest that concentrations of E2 over 62.5 microg/l may cause growth suppression in mysid shrimp, and that the disruption of molting cycles may result in alterations in growth due to a sublethal response to toxicant exposure.

Animals↗
PubMed2003

Silent cleanup of very early apoptotic cells by macrophages.

Apoptotic cells are phagocytosed as soon as they appear in vivo. In this study, we first determined precisely at what stage apoptotic cells are phagocytosed by macrophages, and then examined the subsequent cytokine production. Phagocytosis was confirmed by flow cytometry and confocal laser microscopy, whereas the subsequent response was examined by ELISA and RT-PCR for quantitative and semiquantitative measurement of the protein and mRNA levels of cytokines, respectively. Even the cell populations containing very early apoptotic cells, such as IL-2-dependent CTLL-2 cells cultured in the absence of IL-2 for 4 h and a murine leukemic cell line, P388 cells, treated with etoposide for 5 h, were phagocytosed by macrophages. Although the cell populations containing the very early apoptotic cells used in this study were FITC-Annexin V-negative and did not show a decrease in cell size as compared with untreated cells, they showed a very small increase in phosphatidylserine on the cell surface, as detected with Cy3-Annexin V, and a decrease in mitochondrial membrane potential, indicating that the cell populations had already started the apoptotic process. Phagocytosis of such populations containing very early apoptotic cells was inhibited by phospho-L-serine much more significantly than Arg-Gly-Asp-Ser. In addition, macrophages hardly produced either proinflammatory or anti-inflammatory cytokines after phagocytosis, thus being an almost null response. These results are contrary to the generally accepted concept that the phagocytosis of apoptotic cells leads to the production of anti-inflammatory cytokines, suggesting instead that cells starting to undergo apoptosis are quickly phagocytosed by macrophages without any inflammation in vivo.

Animals↗
PubMed2003

What difference does the choice of SES make in health inequality measurement?

This note explores the implications for measuring socioeconomic inequality in health of choosing one measure of SES rather than another. Three points emerge. First, whilst similar rankings in the two the SES measures will result in similar inequalities, this is a sufficient condition not a necessary one. What matters is whether rank differences are correlated with health - if they are not, the measured degree of inequality will be the same. Second, the statistical importance of choosing one SES measure rather than another can be assessed simply by estimating an artificial regression. Third, in the 19 countries examined here, it seems for the most part to make little difference to the measured degree of socioeconomic inequalities in malnutrition among under-five children whether one measures SES by consumption or by an asset-based wealth index.

Anthropometry↗
PubMed2003

Suppression of differentiation and proliferation of early chondrogenic cells by Notch.

Notch is a transmembrane protein involved in cell fate determination. In the present study, we observed temporally and spatially restricted expression of Notch1 in developing cartilage. Notch1 was localized starting from the mesenchymal condensation stage of embryonic mouse forelimbs. Interestingly, although localization could not be detected in the proliferating chondrocytes, obvious immunoreactivity indicating its expression was retained in the perichondrial region. Next, we investigated the expression of Notch1 and related molecules in a chondrogenic cell line, ATDC5 cells. Notch1, Delta-like (Dll)1, Deltex2, and Deltex3 were coexpressed after 6-day insulin treatment. Expression of Hairy and Enhancer of split homologue (HES)-1 followed thereafter. These results suggest that Notch may have a role in the early stage of chondrogenesis. To assess the effect of Notch activation, we cultured ATDC5 cells with a myeloma clone constitutively expressing Dll1, a ligand of Notch. We also used an adenovirus vector to express the constitutively active Notch1 intracellular domain (NIC). Activating either the endogenous or exogenous Notch receptor dramatically inhibited chondrogenic cell differentiation of ATDC5 cells, as assessed by Alcian blue staining of the cells and chondrocyte differentiation markers. Last, we investigated the effect of NIC on the proliferation of the ATDC5 cells. Expression of NIC by the adenovirus strongly suppressed thymidine incorporation. These results indicate that Notch is expressed in the initial stage of chondrogenic cell differentiation and has a strong inhibitory effect on both differentiation and proliferation of the cells when activated. The expression of Notch decreases as chondrogenic differentiation proceeds; however, a population of the cells with sustained expression of Notch1 become perichondrial cells. Considering that the perichondrium acts as a stem cell source of osteoblasts and chondrocytes, Notch1 may have a role in the formation of these cells by suppressing both differentiation and proliferation.

Adenoviridae↗
PubMed2003

Fidelity of the methylation pattern and its variation in the genome.

The methylated or unmethylated status of a CpG site is copied faithfully from parental DNA to daughter DNA, and functions as a cellular memory. However, no information is available for the fidelity of methylation pattern in unmethylated CpG islands (CGIs) or its variation in the genome. Here, we determined the methylation status of each CpG site on each DNA molecule obtained from clonal populations of normal human mammary epithelial cells. Methylation pattern error rates (MPERs) were calculated based upon the deviation from the methylation patterns that should be obtained if the cells had 100% fidelity in replicating the methylation pattern. Unmethylated CGIs in the promoter regions of five genes showed MPERs of 0.018-0.032 errors/site/21.6 generations, and the fidelity of methylation pattern was calculated as 99.85%-99.92%/site/generation. In contrast, unmethylated CGIs outside the promoter regions showed MPERs more than twice as high (P < 0.01). Methylated regions, including a CGI in the MAGE-A3 promoter and DMR of the H19 gene, showed much lower MPERs than unmethylated CGIs. These showed that errors in methylation pattern were mainly due to de novo methylations in unmethylated regions. The differential MPERs even among unmethylated CGIs indicated that a promoter-specific protection mechanism(s) from de novo methylation was present.

Base Composition↗
PubMed2003

Novel splicing events of untranslated first exons in human estrogen receptor alpha (ER alpha) gene.

In order to analyze the structures of the 5'-untranslated region of estrogen receptor alpha (ER alpha) mRNA in human uterine endometrium (Em), total RNA from Em was analyzed by 5'-rapid amplification of the cDNA ends method with antisense primer located on exon 1 of human ER alpha gene. Three isoforms of 5'-RACE clones were obtained: ER alpha mRNAs containing exon (A) (the upstream region of exon 1), exon C, and exons F-E2 (we adopted the nomenclature of 5'-untranslated exons of the Gannon group). The results imply that the major isoforms of ER alpha mRNA expressed in Em are these three isoforms. Moreover, reverse transcription-polymerase chain reaction (RT-PCR) analysis was carried out on Em, ovary (Ov) and liver (Li) mRNAs to detect the novel isoforms of ER alpha mRNA in these tissues, using sense primers located on exons (A), B, C, F, and E1, and antisense primer located on exon 1. As a result, in addition to the previously reported ER alpha mRNA isoforms containing exons (A), B, C, F-E2 and E1-E2 on exon 1, we identified two novel isoform mRNAs in which exons F and E1 were directly spliced onto exon 1. Differential distributions of these isoforms of ER alpha mRNAs in Em, Ov and Li were demonstrated by RT-PCR-Southern blot analysis. These results, together with the previous reports by others, indicate that there are at least ten isoforms of ER alpha mRNA containing different 5'-untranslated regions, exons (A), B, C, D, T1-T2, T1, F-E2, F, E1-E2 and E1, expressed in human, and that these are involved in tissue specific expression of the gene.

Base Sequence↗
PubMed2003

Association of intestinal malignant lymphoma and ulcerative colitis.

A 42-year-old woman with refractory ulcerative colitis (UC) developed ascites, pleural effusion, pretibial edema and severe anemia. Colonofiberscopic examination showed a bulky submucosal tumor in the sigmoid colon, which was histologically diagnosed as malignant lymphoma (diffuse large, B cell type). The lymphoma was resistant to chemotherapy. Autologous peripheral blood stem cell transplantation (PBSCT) was effective; however, she died of severe infection after the second PBSCT. Although the association of intestinal lymphoma with UC is rare, lymphoma should be taken into consideration when the clinical course of UC is atypical or when UC is refractory to therapy.

Adult↗
PubMed2002

Single nucleotide instability: a wide involvement in human and rat mammary carcinogenesis?

Genetic instability plays important roles in carcinogenesis. In two cell lines which we established from mammary carcinomas induced in lacI-transgenic rats by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), spontaneous point mutation rates (MRs) of the endogenous hypoxanthine-guanine phosphoribosyltransferase (hprt) gene and lacI transgene were found to be increased. The two rat mammary carcinoma cell lines lacked microsatellite instability (MSI), and nuclear extracts from them were proficient in G/T mismatch binding. The increase of spontaneous point MRs was considered to be due to a mechanism(s) different from mismatch repair insufficiency, and this type of genetic instability was termed as single nucleotide instability (SNI). SNI in the rat mammary carcinoma cell lines was characterized by the elevation of A:T to C:G transversions of the hprt and lacI genes, which were rarely observed in normal mammary epithelial cells. The elevation of A:T to C:G transversions was also present in the lacI gene of the primary carcinomas of the two cell lines, which suggested that the molecular abnormality present in the cell lines was already present in their primary carcinomas. Mth1 mutation, which is known to cause elevation of A:T to C:G transversions, was analyzed in the 2 cell lines and in 11 primary PhIP-induced mammary carcinomas, but no mutations were observed. Finally, spontaneous point MRs of the hprt gene were measured in six human breast cancer cell lines, and increase was found in five of them. These human breast cancer cell lines were proficient in G/T mismatch binding, and were reported to lack MSI. SNI was suggested to play a wide involvement in human and rat mammary carcinogenesis.

Animals↗
PubMed2002

Etiology-specific gene expression profiles in rat mammary carcinomas.

Identification of etiology of human cancers is important for effective cancer prevention, and attempts to estimate the roles of a variety of environmental carcinogens in human cancers are being made. Here, we applied cDNA microarray technology to estimate whether gene expression profiles of cancers would reflect their etiology. Using rat mammary carcinoma models, expression profiles were analyzed in two groups of carcinomas induced by distinct carcinogens but with the same histological classification. Four carcinomas induced by 7,12-dimethylbenz[a]anthracene (DMBA) and three carcinomas induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and a high-fat diet were analyzed by a GeneChip oligonucleotide microarray that contained approximately 8000 rat genes. By hierarchical clustering analysis, the seven carcinomas were classified into two groups that exactly coincided with the DMBA-induced and the PhIP-induced groups. The correlation coefficient between the two groups was 0.63, and those between any carcinomas within each group ranged from 0.78 to 0.95. In addition, characteristic clusters of genes were also identified that highlighted distinct and common characteristics of both groups. Seventeen genes were down-regulated in the DMBA and up-regulated in the PhIP-induced groups. Thirty-three genes were regulated in the opposite manner. Our results indicated that gene expression profiles in cancers reflect their etiology and suggested a possibility that etiology of cancers could be retrospectively estimated from their expression profiles.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2002

Exip, a new alternative splicing variant of p38 alpha, can induce an earlier onset of apoptosis in HeLa cells.

One of the major families of the mitogen-activated kinases (MAPK), p38, has been shown to transduce extracellular stress stimuli into cellular responses. Among them, p38 alpha is the best characterized isoform and many biological phenomena, especially in the inflammatory responses, were attributed to the specific inhibitor-sensitive isoforms, namely p38 alpha and p38 beta. However, the roles played by each member are still unclear. Here, we report the identification of a new splice variant of p38 alpha, Exip (for exon skip), by RT-PCR using mRNA derived from a renal tumor cell line, OS-RC-2. Exip is predicted to encode a 307-amino-acid protein and the absence of exons 10, 11, and 11' results in the shift of the reading frame at the exon 9-12 junction to produce a unique 53-amino-acid C-terminus. The expression of mRNA was barely observed in cultured cells tested, but substantial amounts of mRNA were detected in mouse tissues. Unlike p38 alpha, Exip lost a common docking domain well conserved in major MAPK families for their specific interactions with upstream kinases or downstream substrates. Even though Exip is not phosphorylated at conserved TGY motif by p38-activating treatments, such as an osmotic shock or coexpression with a constitutive active form of MKK6 in HeLa cells, Exip can induce an earlier onset of apoptosis in HeLa cells. These results indicate that Exip has unique properties as a member of p38 alpha and may play role(s) in the signal transduction pathway(s) different from those of p38 alpha.

3T3 Cells↗
PubMed2002

Studies on mammary carcinogenesis induced by a heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, in mice and rats.

Ten heterocyclic amines (HCAs) that are produced by heating amino acids, proteins, or proteinaceous food such as fish and meat were examined for carcinogenicity in rats and mice. Three of them, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), have been shown to induce mammary cancer in female F344 and/or SD rats, but none of the HCAs induced mammary cancer in CDF(1) mice. This report reviews our recent studies on mammary carcinogenesis of PhIP in various strains of mice and on the roles of genomic instability in the rat mammary carcinogenesis of PhIP. We demonstrated that the survival time from mammary adenocarcinomas was shorter in PhIP-treated BALB/c mice than that in the untreated control, and with a significantly higher incidence in the C.B-17 strain of mice compared with that of the control. To clarify mechanisms of mammary carcinogenesis, we examined genomic instability in rat mammary cancer induced by PhIP. Mammary cancers were induced in F344 x SD F(1) rats harboring the lacI transgene, and two cell lines were established from two adenocarcinomas. They showed a greater than 10-fold higher frequency of spontaneous mutations than that of the primary culture of normal mammary epithelial cells, in the lacI transgene and the hprt endogenous gene during cell replication. Nucleotide sequencing revealed that almost all types of mutations were increased, with a remarkable increase of A:T --> C:G mutation. This genomic instability was not attributed either to alterations of mismatch-repair enzymes or to p53. These mutational characteristics were also observed in the original tumors. Single-nucleotide instability (SNI) might be implicated in the mammary cancer induced by PhIP.

Adenocarcinoma↗