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S Koizumi

Publications and source records attributed to S Koizumi.

At least 73 records · Page 4Linked to original sources
PubMed1999

Differential metal response and regulation of human heavy metal-inducible genes.

A number of heavy metal-inducible genes have been reported, but their ranges of response to various metal species are not well known. It is also unclear if these genes are regulated through common mechanisms. To answer these questions, we compared induction kinetics of human metal-inducible genes including the MT-IIA (coding for a metallothionein isoform), hsp70 (coding for the 70-kDa heat-shock protein), and c-fos genes in HeLa cells exposed to Zn, Cd, Ag, Hg, Cu(II), Co, or Ni ions. Transcripts from these three genes were increased after exposure to wide ranges of metals, but each gene was unique in its induction kinetics. Generally, induction was observed at lower metal concentrations in the order of MT-IIA, hsp70, and c-fos. These genes also showed differential responses in time course: more rapid induction was observed in the order of c-fos, hsp70, and MT-IIA after exposure to Zn or Cd. Since the metal-responsive element (MRE) and heat shock element (HSE) of the MT-IIA and hsp70 genes, respectively, are thought to be the cis-acting DNA elements that mediate metal response, we compared the properties of proteins that specifically bind to these elements. MRE-binding activity was detected only in the extract from cells exposed to Zn. By contrast, HSE-binding activity was detected in extracts from cells treated with Zn, Cd, Ag, and Cu. The former was also activated by Zn in vitro, while the latter was not. Each of these DNA-binding activities showed no affinity to the recognition sequence of the other. These results demonstrate that the human metal-inducible genes have broad ranges of response to a variety of heavy metals, but suggest that they are probably regulated through independent mechanisms.

Antigens, Nuclear↗
PubMed1999

Pancreatoduodenectomy for locally advanced or recurrent colon cancer: report of two cases.

A 66-year-old man, who had ascending colon cancer which invaded the duodenum, pancreas, and superior mesenteric vein, underwent a curative resection including an extended right hemicolectomy, pylorus-preserving pancreatoduodenectomy, and a partial resection of the superior mesenteric vein. The pathological examination revealed adenocarcinoma of the colon, which directly invaded the duodenum and pancreas, thus causing duodenocolic fistula. Tumor infiltration to the superior mesenteric vein was not histologically proven. Two out of 40 lymph nodes were also involved. The patient is still alive and disease-free 37 months after the operation. A 72-year-old man, with a history of surgery two previous times for ascending colon cancer and its recurrence, underwent a third operation including a resection of the former ileocolic anastomosis en bloc by means of a pylorus-preserving pancreatoduodenectomy with a curative intent. The pathological examination revealed adenocarcinoma of the colon, which directly invaded the duodenum and pancreas. Seven out of 31 lymph nodes were also involved. The patient died of recurrence 24 months after the third operation. These two cases demonstrated the usefulness of a resection of the colon en bloc by means of a pancreatoduodenectomy in patients with either locally advanced colon cancer or locally advanced recurrent colon cancer.

Adenocarcinoma↗
PubMed1999

Impaired response of granulocyte-committed progenitor cells to stem cell factor and granulocyte colony-stimulating factor in human cyclic neutropenia.

Although cyclic neutropenia (CN) has been the subject of extensive studies due to its striking clinical picture, the abnormality of hematopoietic progenitor cells in patients with CN has been poorly defined. We studied the sensitivity of progenitor cells of a CN patient to colony-stimulating factors (CSF) including G-CSF, interleukin-3 (IL-3), and stem cell factor (SCF). Peripheral blood progenitor cells of the patient required a significantly higher dose of G-CSF to give rise to colonies than those of normal controls. While the presence of SCF enhanced the number of G-CSF-induced colonies regardless of the concentration of G-CSF in normal controls, this synergistic effect of SCF was limited to the high concentration of G-CSF in the patient, indicating that the abnormality in hematopoiesis in CN involved more immature progenitor cells responsive to SCF.

Adult↗
PubMed1999

Selectively induced high MRP gene expression in multidrug-resistant human HL60 leukemia cells.

A subclone HL60/DOX was selected from a human leukemic HL60 cell line for resistance to doxorubicin (DOX) by exposure to stepwise increasing concentrations of the drug and coexposure to a potential P-glycoprotein (P-gp) inhibitor, cepharanthine (a biscoclaurine alkaloid). Compared with the parent HL60 cells, the HL60/DOX cells were 13.0-fold more resistant to DOX and showed multidrug-resistant (MDR) phenotype characterized by 4.6-fold, 2.3-fold, and 5.7-fold cross-resistance to vincristine, pirarubicin, and etoposide, respectively, but no cross-resistance to alkylating agent, cisplatin. Immunocytochemical analyses using the specific monoclonal antibody, MRPr1, and quantitative analyses using a competitive reverse transcription-polymerase chain reaction (CRT-PCR) confirmed overexpression of MRP gene products (about 8-fold determined by CRT-PCR) in this resistant clone. The P-gp expression was not detectable by the monoclonal antibody, C219, in the HL60/DOX cells, and that was consistent with extremely low levels of mdr1 mRNA expression determined by CRT-PCR in this clone. Drug accumulation and efflux studies demonstrated the significantly increased efflux rate of DOX compared to the parent HL60 cells. This enhancement of DOX efflux was reversed by the addition of 10 microM verapamil. To investigate the additional underlying mechanisms contributing to MDR phenotype in the HL60/DOX cells, the levels of DNA topoisomerases (Topo) including Topo I, Topo IIalpha, and Topo IIbeta, and gamma-glutamylcystein synthetase (y-GCS) expression were determined using CRT-PCR techniques. Normal expression of each enzyme at the transcriptional level was demonstrated in this resistant clone. Southern blot analysis of the gene organization in the HL60/DOX cells revealed the amplification of MRP gene. These results indicate that alteration of the drug accumulation from enhanced efflux appears to be a major mechanism(s) of MDR phenotype and attributable to high levels of MRP expression in the HL60/DOX cells. Overexpression of MRP in this clone is regulated by the genomic amplification of DNA and increased levels of the MRP mRNA, independently with the normal expression of Topo I, Topo IIalpha, Topo IIbeta, or gamma-GCS.

ATP-Binding Cassette Transporters↗
PubMed1999

Characterization of elementary Ca2+ release signals in NGF-differentiated PC12 cells and hippocampal neurons.

Elementary Ca2+ release signals in nerve growth factor- (NGF-) differentiated PC12 cells and hippocampal neurons, functionally analogous to the "Ca2+ sparks" and "Ca2+ puffs" identified in other cell types, were characterized by confocal microscopy. They either occurred spontaneously or could be activated by caffeine and metabotropic agonists. The release events were dissimilar to the sparks and puffs described so far, as many arose from clusters of both ryanodine receptors (RyRs) and inositol 1,4,5-trisphosphate receptors (InsP3Rs). Increasing either the stimulus strength or loading of the intracellular stores enhanced the frequency of and coupling between elementary release sites and evoked global Ca2+ signals. In the PC12 cells, the elementary Ca2+ release preferentially occurred around the branch points. Spatio-temporal recruitment of such elementary release events may regulate neuronal activities.

Animals↗
PubMed1999

Internal tandem duplication of the FLT3 gene and clinical evaluation in childhood acute myeloid leukemia. The Children's Cancer and Leukemia Study Group, Japan.

We analyzed tandem duplication in the juxtamembrane (JM) domain of the FLT3 (FMS-like tyrosine kinase 3/FLK2, CD135) gene in 94 children with acute myeloid leukemia (AML) and evaluated its correlation with clinical features. Longer polymerase chain reaction (PCR) products were observed in five patients; 1/3 of M0, 119 of M1, 1/39 of M2, 1/9 of M3 and 1/12 of M5. The sequence analyses of abnormal PCR products showed that all the abnormal products were derived from tandem duplications involving the JM domain and that all the lengthened sequences were in-frame as we previously reported. Statistical analyses revealed a significantly lower incidence of the tandem duplication in childhood AML patients than in adult patients (P < 0.05), and significantly shorter disease-free survival in patients with mutant FLT3 than in patients with wild-type FLT3 (P < 0.05). Our results suggest that the tandem duplication in the JM domain of the FLT3 gene is not a frequent phenomenon but might be a factor of poor prognosis in childhood patients with AML.

Acute Disease↗
PubMed1999

Transcriptional activity and regulatory protein binding of metal-responsive elements of the human metallothionein-IIA gene.

Multiple copies of a cis-acting DNA element, metal-responsive element (MRE) are required for heavy metal-induced transcriptional activation of mammalian metallothionein genes. To approach the regulatory mechanism mediated by these multiple elements, we studied the properties of seven MREs located upstream of the human metallothionein-IIA (hMT-IIA) gene in detail. Transfection assays of reporter gene constructs each containing one of these MREs as the promoter element revealed that only four MREs can mediate zinc response. With respect to the distribution of active MREs over the promoter region, the hMT-IIA gene is largely different from the mouse metallothionein-I gene, suggesting that MRE arrangement is not an important factor for metal regulation. Experiments using various model promoters showed that multiple MRE copies act highly synergistically, supporting the biological significance of the multiplicity. Only the four active MREs efficiently bound the purified transcription factor human MTF-1, and MRE mutants defective in binding this protein lost the ability to support zinc-induced reporter gene expression, strongly suggesting that the direct interaction between human MTF-1 and a set of the selected MREs plays the major role in heavy metal regulation. In protein/DNA binding reactions in vitro, the purified human MTF-1 was activated by zinc but not by other metallothionein-inducing heavy metals, supporting the idea that zinc is the direct modulator of human MTF-1.

DNA-Binding Proteins↗
PubMed1999

Microsatellite analysis of childhood leukemia: correlation of 9p and 12p chromosome abnormalities with expression of related genes.

BACKGROUND: Loss of heterozygosity (LOH) and DNA replication error (RER) have been thought to be involved in carcinogenesis, but have not been investigated in childhood leukemia and lymphoma. METHODS: Eighty samples from 65 patients with childhood leukemia and lymphoma were examined using seven different microsatellite markers for RER analysis. Additionally, LOH in two chromosome regions (9p and 12p) was investigated. Furthermore, expression of the TEL, TEL/AML1 and p27(KIP1) genes on 12p and the p16 gene on 9p were detected by reverse transcriptase polymerase chain reaction. RESULTS: Replication errors were detected in 5/65 patients (7.7%). Most (4/5 patients) RER were preferentially located in the 9p and 12p regions. There were two patients who had DNA abnormalities in both 9p and 12p, one with common acute lymphoblastic leukemia (ALL) showed 9p LOH and the TEL/AML1 fusion gene on 12p and the other with common ALL and 12p RER had diminished expression of both the p27(KIP1) gene on 12p and the p16 gene on 9p. CONCLUSIONS: Combined DNA alterations on 9p and 12p, involving LOH, RER and/or gene mutation and chromosomal translocation, were found in childhood acute leukemia, especially in common ALL.

Child↗
PubMed1999

[An analysis of fever of unknown origin defined by newly proposed practical criteria. A prospective study of 56 cases].

The criteria proposed by Petersdorf has been in use internationally to define the fever of unknown origin (FUO) since 1961 and the research of FUO has progressed with this criteria. Mean-while, new diagnostic methods have been developed and illness behavior of febrile patients has changed considerablly. Accordingly, the definition by Petersdorf is becoming less matched to current clinical situation. Therefore, we have developed a new practical criteria of FUO; i.e., out-patients who are febrile more than 2 weeks, documented temperature higher than 37.5 degrees C at least on one occasion and undetermined diagnosis and in-patients who are febrile more than 1 week with documented temperature higher than 37.5 degrees C, and undetermined diagnosis. Between October 1, 1993, and October 31, 1996, we prospectively collected a series of febrile patients who fulfilled our new criteria. We identified 56 patients by our criteria (23 male and 33 female, age: 49.7 +/- 20.6. range 15 to 88). Of this 56 patients, 19 (32%) were found to have infections, 18 (31%) had collagen disorders, 5 (9%) had malignancy and 6 (10%) had died. Of 56 patients, 38 (68%) were in the newly added group. Of these 38 patients, 4 patients had subacute necrotizing lymphoadenitis, 4 cytomegalovirus infection, 3 polymyalgia rheumatica, 3 tuberculosis. Four patients (10%) died. With our criteria, febrile patients who previously had not been included were found to have as poor a prognosis as with the Petersdorf group.

Adolescent↗
PubMed1999

Oxidative stress causes enhanced endothelial cell injury in human heme oxygenase-1 deficiency.

The first known human case of heme oxygenase-1 (HO-1) deficiency is presented in this report. The patient is a six-year-old boy with severe growth retardation. He has been suffering from persistent hemolytic anemia characterized by marked erythrocyte fragmentation and intravascular hemolysis, with paradoxical increase of serum haptoglobin and low bilirubin. An abnormal coagulation/fibrinolysis system, associated with elevated thrombomodulin and von Willebrand factor, indicated the presence of severe, persistent endothelial damage. Electron microscopy of renal glomeruli revealed detachment of endothelium, with subendothelial deposition of an unidentified material. Iron deposition was noted in renal and hepatic tissue. Immunohistochemistry of hepatic tissue and immunoblotting of a cadmium-stimulated Epstein-Barr virus-transformed lymphoblastoid cell line (LCL) revealed complete absence of HO-1 production. An LCL derived from the patient was extremely sensitive to hemin-induced cell injury. Sequence analysis of the patient's HO-1 gene revealed complete loss of exon-2 of the maternal allele and a two-nucleotide deletion within exon3 of the paternal allele. Growth retardation, anemia, iron deposition, and vulnerability to stressful injury are all characteristics observed in recently described HO-1 targeted mice. This study presents not only the first human case of HO-1 deficiency but may also provide clues to the key roles played by this important enzyme in vivo.

Animals↗
PubMed1999

Age-dependent increase of IgE-binding and FcepsilonRI expression on circulating basophils in children.

Peripheral blood basophils are sparse in the circulation, but they express high-affinity receptors for IgE (FCepsilonRI) and bind IgE efficiently. The present study was performed to elucidate the role of IgE bound on the basophil surface in the development of allergic responses during infancy and early childhood. IgE-binding and FcepsilonRI expression on basophils were evaluated by two-color flow cytometry. Basophil-bound IgE increased rapidly and reached adult levels during infancy in atopic patients, while it gradually increased with advancing age in parallel with serum IgE in normal controls. IgE-binding and FcepsilonRI expression in atopic children were higher than in normal controls among various age groups. They correlated with serum IgE levels but reached a plateau when serum IgE exceeded 300 ng/mL. A low, but significant level of FcepsilonRI expression was observed on cord blood basophils, although IgE-binding was usually undetectable. Incubation of cord blood with IgE rapidly saturated the preexisting IgE receptors and basophil-bound IgE levels increased. When neonatal basophils were cultured for 48 h with IgE, FcepsilonRI expression was upregulated dose-dependently and IgE-binding increased further. The up-regulation of FcepsilonRI was completely inhibited by cycloheximide, indicating that it was dependent on de novo protein synthesis. These results suggest that IgE-binding on basophils serves as a sensitive indicator of allergic sensitization, and that IgE functions as a positive regulator of FcepsilonRI expression in vivo.

Adolescent↗
PubMed1999

[An analysis of questionnaires about geriatric medicine/medical education sent to members of the Japanese Society of General Medicine].

Geriatric medical care can be viewed as general medical care for the elderly. We conducted a survey of members of the Japanese Society of General Medicine who belong to a university hospital, on their views of geriatric medicine/medical education. The questionnaires consisted of six categories of items about: (1) the physician's career; (2) whether the physician performs geriatric research in his/her laboratory; (3) whether the physician has an interest in geriatric medicine or medical education; (4) the physician's views on geriatric medicine or medical education; (5) of what pre- and post-graduate medical education on geriatric medicine should consist, from the physician's point of view: and (6) the physician's ideas about geriatric medicine/medical education in view of general medicine. Out of the 181 questionnaires sent, 96 (53%) people replied, of whom 51 (53.1%) were members of a Department of General Medicine, 57 (60%) were teaching staff, 46 (48.4%) had experience in home medical care such as home visits, and 17 (18.1%) belonged to the Japanese Society of Geriatric Medicine. Seventy-six respondents (85.4%) had an interest in geriatric medicine/medical education. Of the respondents, 96.8% recognized the need for pre- and post-graduate medical education concerning geriatrics. Some members of the Japanese Society of General Medicine who answered the questionnaire see geriatric medicine as entirely general medicine, and also that geriatric medicine is important, necessary and special. In addition, they see that the field of geriatric medicine is not yet developed in regard to geriatric medical care and education. Most respondents could not specify which section in a medical university is responsible for teaching the fields of basic and social medicine. This result shows that it may be difficult to incorporate pre-graduate geriatric medical education into the curriculum. As part of the pre-graduate curriculum of medical education on geriatrics, a practical exercise such as inspection of a geriatric hospital and geriatric home was considered most desirable by the respondents. Out of nine items, the top three most important aspects of post-graduate medical education on geriatrics for clinical and social medicine, were (1) studying the medical care and welfare of the elderly, (2) assessing the impaired life function of the elderly, and (3) studying pharmaco- therapy. Out of 6 items, the top three most important aspects of a practical exercise in post-graduate medical education in geriatrics were (1) providing general care to the elderly, (2) giving rehabilitation guidance and (3) providing psychological support for the elderly. Furthermore, 20 of the respondents (22.5%) have performed geriatric medical research on either the activities of daily life of the elderly or living wills, both of which seem to reflect the health and life of elderly people.

Attitude of Health Personnel↗
PubMed1999

The clinical epidemiological investigation of diagnostic modalities in breast cancer detection--a comparison of ultrasonography and mammography.

We reviewed the medical records and images of 39 women with palpable breast masses, including 18 cases with breast cancer and 21 cases with benign breast mass, to compare diagnostic accuracy and clinical agreement between ultrasonography and mammography in breast cancer detection. We showed that the operating characteristics of ultrasonography, including sensitivity, specificity and positive likelihood ratio, were superior to that of mammography. We also confirmed that the established malignant criteria for malignancy, including lobulated shape, irregular contour and non-uniform internal echo in ultrasonography, and stellate mass in mammography, were statistically significant in distinguishing breast cancer from benign breast lesion. Moreover, the interobserver agreement kappa of ultrasonography and mammography were 0.64 and 0.59, respectively. Ultrasonography was also superior to mammography in attaining clinical agreement between the different observers in breast cancer detection.

Breast Neoplasms↗
PubMed1999

[Treatment for advanced colorectal carcinoma with 5-fluorouracil plus low-dose leucovorin].

From July 1992 to May 1996, 16 patients with non-curative postoperative or recurrent colorectal carcinomas were treated with 5-fluorouracil (5-FU) plus leucovorin (LV) systemic chemotherapy. LV was given at a dose of 20 mg/m2/d immediately followed by 5-FU at 370 mg/m2/d. LV was given by rapid intravenous (i.v.) injection and 5-FU by rapid or drip i.v. for 5 consecutive days. Courses were repeated once every 4 weeks for two months and then once every 5 weeks. All patients took 3 or more courses. The toxicity was tolerable, but one patient needed hospitalization because of severe gastro-intestinal toxicity. We observed 3 PR cases, no CR and an overall response rate of 19%. The response duration was 6 to 8 months, averaging 7.3 months, and median survival was 12 months. It was possible to perform this chemotherapy on an outpatient basis, so we think this chemotherapy is superior to in-hospital chemotherapy considering the issue of quality of life. However, the response rate was low and its duration was short. We must investigate chemotherapy further with new and more powerful chemical modulations to increase the response rate and to prolong the response duration.

Adenocarcinoma↗
PubMed1999

[Treatment for a high-risk group for childhood acute lymphoblastic leukemia].

Chemotherapy regimens for high-risk (HR) groups for childhood acute lymphoblastic leukemia (ALL) are briefly reviewed in this study. For patients with B-precursor ALL, the HR category includes patients more than 10 years of age who have a WBC count at diagnosis of more than the 50,000/microliter that is becoming a global standard for HR classification. Since 1981, the Children's Cancer and Leukemia Study Group (CCLSG) has developed a series of protocols for HR-ALL. These include the H811, H851, H874, H/HH911 and more recent H/HH941 protocols. With the H874 protocol in particular, patient outcomes with new intensive regimens strengthened by early treatment with cyclophosphamide (CPM) plus cytosine arabinoside (Ara-C), and reinduction therapy with THP-adriamycin, vincristine, prednisone and L-asparaginase seem to be better than outcomes of patients with the previous protocols. An intermediate-dose of CPM plus Ara-C showed a significantly higher event-free survival (EFS) rate than a high-dose regimen with the same drugs. The EFS rates at 4 years based on the H941 and HH941 protocols were 72.8% and 62.8%, respectively. Although the various prognostic factors for acute myelogenous leukemia (AML) have been inconsistent, bone marrow chromosome abnormalities including monosomy 7 an 11q23 rearrangement have become indicators for a poor prognosis, whereas patients with t (15; 17), t (8; 21) and inv (16) have a decreased likelihood of relapse after achieving remission. The 11q23 abnormality is a very important prognostic factor for infant acute leukemia. Based on these findings renewal protocols for AML, including hematopoietic stem cell transplantation, have been conducted by our CCLSG and other study groups.

Antineoplastic Combined Chemotherapy Protocols↗