Biomedical subjects

K Itoh

Publications and source records attributed to K Itoh.

At least 451 records · Page 25Linked to original sources

PubMed1998

The combination of photocatalysis and ozonolysis as a new approach for cleaning 2,4-dichlorophenoxyaceticacid polluted water.

Treatment of 2,4-D polluted waters with photocatalysis leads to the buildup of high concentrations of the long living intermediate 2,4-DCP. A new approach using a combination of ozonolysis and photocatalysis gave better degradation results with lower intermediate concentrations. The advantages of photocatalysis giving a constant decline in TOC and of ozonolysis giving no buildup of high intermediate concentrations were combined. Degradation data of 2,4-D for photocatalysis, ozonolysis and the combination of both for different pH ranges are given. Data on the main intermediate 2,4-DCP are given for the three different approaches.

2,4-Dichlorophenoxyacetic Acid↗

PubMed1998

Ultrasound instruments as possible vectors of staphylococcal infection.

In this study, we evaluated whether ultrasound instruments are important in the spread of nosocomial staphylococcal infections. Following genomic typing by pulsed-field gel electrophoresis, it was apparent that ultrasound procedures transferred colonizing staphylococci from a patient's skin to the ultrasound instruments. Staphylococcus aureus survived in the transmission medium for longer than in water. Furthermore, S. aureus was more resistant to the ultrasonic medium than Pseudomonas aeruginosa, also a significant cause of hospital-acquired infections. To prevent staphylococcal transmission by ultrasound equipment, we recommend disinfection of the probe and removal of the medium after each examination.

Cross Infection↗

PubMed1998

Bonding efficacy and interfacial microstructure between resin and dentine primed with glyceryl methacrylate.

OBJECTIVES: To evaluate the effect of two experimental primers based on glyceryl methacrylate (GM, 2,3-dihydroxypropyl methacrylate) and 2-hydroxyethyl methacrylate (2-HEMA) on the marginal adaptation of light-cured composite placed into cylindrical dentine cavities and to study the interfacial microstructure. METHODS: The bonding efficacy of two experimental dentine primers combined with a dentine cleanser composed of either 0.5 mol l-1 EDTA neutralized to pH 7.4 by sodium hydroxide or 10% citric acid containing 3% ferric chloride (10-3 solution), and a commercial dentine bonding agent containing phosphate ester, were examined by measuring the wall-to-wall polymerization contraction gap of a commercial light-activated resin composite placed into cylindrical dentine cavities. The adhesive interface between the dentine and the dentine adhesive was observed using a transmission electron microscope (TEM). RESULTS: The formation of a contraction gap was completely prevented by priming with GM, regardless of the dentine cleanser used. However, in groups primed with 2-HEMA, gap formation was observed in three and four specimens out of 10 in the groups that were cleaned with the EDTA and 10-3 solution, respectively. In samples primed with GM, a high-density layer was observed by TEM at the superficial dentine in the hybrid layer, which may have indicated a high monomer content, whereas no density variations were observed in the hybrid layer in samples primed with 2-HEMA.

Adhesives↗

PubMed1998

A role for Xenopus Frizzled 8 in dorsal development.

The establishment of cell and tissue polarity during animal development often requires signaling by Wnts, extracellular signaling polypeptides. Transmembrane receptors of the Frizzled family are implicated in the transduction of Wnt signals in responding cells. Xfz8 is a novel cDNA encoding a Xenopus homologue of mouse Frizzled 8. Xfz8 transcripts are expressed zygotically in the organizer at the early gastrula stage and in the most anterior ectoderm at later stages, suggesting a role in axis specification. When Xfz8 mRNA is overexpressed in ventral marginal zone cells, a secondary body axis with prominent head structures develops. Surprisingly, axis induction was not accompanied by activation of early dorsal marginal zone markers at the gastrula stages, whereas Xwnt8 induced these markers with high efficiency. These findings suggest that Xfz8 is a product of the organizer and mimics its function. Head induction by Xfz8 was blocked by co-expression of GSK3beta or a dominant negative form of Xenopus Dishevelled, suggesting that this effect of Xfz8 requires Wnt signal transduction. When Xfz8 is overexpressed in animal pole cells, dorsal marginal zone markers Xnr3, Xotx2 and a promoter construct for Siamois, were selectively activated, demonstrating the difference in competence between animal pole cells and ventral marginal zone cells in response to Xfz8. It is proposed that the Wnt pathways are activated at two different steps during axis formation: to induce the Spemann organizer and to implement organizer functions by triggering dorsoanterior development.

Amino Acid Sequence↗

PubMed1998

Toxicity and efficacy of ifosfamide, carboplatin and etoposide (modified ICE) as a salvage chemotherapy in Japanese patients with relapsed or refractory aggressive non-Hodgkin's lymphoma.

The combination of ifosfamide, carboplatin and etoposide (modified ICE), was evaluated for its toxicity and activity in relapsed or refractory aggressive non-Hodgkin's lymphoma. Twenty patients, 14-69 years of age, with relapsed (19 cases) or refractory (one case) aggressive non-Hodgkin's lymphoma were treated with modified ICE therapy, consisting of ifosfamide 6 g/m2 (1.2 g/m2 day 1-5), carboplatin 400 mg/m2 (day 1) and etoposide 500 mg/m2 (100 mg/m2 day 1-5). The regimen was repeated at approximately 28-day intervals. All patients had undergone a doxorubicin-containing regimen before modified ICE therapy. Median total dose of previously received doxorubicin was 406 mg/m2 (range: 200-825 mg/m2). The median interval from diagnosis to modified ICE therapy was 9.4 months (range: 3.6-121 months). Two patients achieved CR and five achieved PR out of 16 patients with measurable lesions (response rate 43.8%; 95% confidence interval 19.0-68.6%). Median overall survival was 227 days (range: 41-552 days) from the start of modified ICE therapy. Myelosuppression was the most serious toxicity, namely 16 patients (80%) and 11 patients (55%) showed grade 4 neutropenia and grade 4 thrombocytopenia after the first course, respectively. Modified ICE therapy might be an active regimen with acceptable toxicity as a salvage chemotherapy in aggressive non-Hodgkin's lymphoma.

Adolescent↗

PubMed1998

Biological effects of a relatively low concentration of 1-beta-D-arabinofuranosylcytosine in K562 cells: alterations of the cell cycle, erythroid-differentiation, and apoptosis.

Therapeutic strategies for leukemia are directed to induction of differentiation and apoptosis as well as growth inhibition. One of the key antileukemic agents, 1-beta-D-arabinofuranosylcytosine (ara C), is clinically applied according to these therapeutic aims. However, the molecular effects of 0.1 microg/ml of ara C, a concentration that corresponds to the serum level in leukemic patients on a conventional dose of ara C, have not been well disclosed. Here, we addressed these issues using K562 cells which derived from a blastic crisis of chronic myeloid leukemia. DNA synthesis of treated cells was suppressed from 1-6 h. But, it recovered at 12 h and no further inhibition was observed. The number of cells was not decreased but DNA fragmentation was observed at 72 h. The number of erythroid-differentiated cells also increased to 30% at 72 h. Along with treatment, no marked alteration of mRNAs for cell cycle-regulating genes was found and the retinoblastoma gene product remained hyperphosphorylated throughout treatment. The expression of mRNAs for apoptosis-regulating genes also remained unchanged, except for slight down-regulation of Bax. c-myc protein was not found later than 48 h, and Max mRNA was downregulated. c-jun was immediately induced, followed by the fluctuated expression level along with treatment. These findings suggest that the 0.1 microg/ml ara C changed the proliferation, differentiation and death of K562 cells in a biphasic manner. In the early phase, DNA synthesis was inhibited without altering the expression of cell cycle regulating-genes. In the latter phase, cell death and erythroid- differentiation occurred in accordance with the down-regulation of c-myc.

Apoptosis↗

PubMed1998

Effectiveness of weekly subcutaneous recombinant human erythropoietin administration for chemotherapy-induced anemia.

The effects of weekly subcutaneous recombinant human erythropoietin (r-hEPO) administration on anemia during chemotherapy including cisplatin and 5-fluorouracil in patients with head and neck carcinomas were examined. Weekly subcutaneous r-hEPO administration in cancer patients has not been investigated previously. Patients were treated with r-hEPO 100 IU/kg (2 patients), 200 IU/kg (6 patients), or 400 IU/kg (5 patients), or placebo, and effectiveness was evaluated by monitoring hemoglobin concentration changes after administration for 8 weeks. Hemoglobin concentrations in all 3 r-hEPO dosage groups were higher than that in the control group during chemotherapy. All r-hEPO doses produced improvements in the anemia induced by chemotherapy; however, the 400 IU/kg dose was most effective. The requirement for blood transfusions decreased in patients receiving r-hEPO therapy, and no significant side-effects were associated with r-hEPO administration. These results suggest that chemotherapy-induced anemia can be prevented by weekly subcutaneous r-hEPO administration.

Aged↗

PubMed1998

Predicting chemotherapeutic response to small-cell lung cancer of platinum compounds by thallium-201 single-photon emission computerized tomography.

Thallium-201 single-photon emission computerized tomography (SPECT) was used to clarify the relationship between 201Tl uptake and the response in chemotherapy to platinum compounds in 21 patients with small-cell lung cancer. 201Tl-SPECT scans were obtained twice: at 15 min (early scan) and 120 min (delayed scan) after an intravenous injection of 111 MBq (3 mCi) of thallium-201 chloride. We obtained the uptake ratio from each scan and calculated the retention index:uptake ratio = region of interest uptake/contralateral normal lung uptake; retention index = (delayed ratio - early ratio)/early ratio. After 201Tl scintigraphy, 12 patients received chemotherapy consisting of platinum compounds and nine were treated with chemoradiation. Among patients receiving only chemotherapy, the retention index correlated with the responses to chemotherapy. In an in vitro study, ouabain, an inhibitor of the Na,K-ATPase pump, reduced sensitivity to cisplatin and inhibited intracellular thallium uptake in the small-cell lung cancer cell line. These studies suggest that 201Tl-SPECT is a useful indicator of response to chemotherapy with platinum compounds in small-cell lung cancer, and that Na,K-ATPase is commonly involved in transporting both thallium and platinum compounds into cancer cells.

Aged↗

PubMed1998

A phase I trial of docetaxel and 5-day continuous infusion of 5-fluorouracil in patients with advanced or recurrent breast cancer.

To determine the maximum-tolerated doses (MTDs), the dose-limiting toxicities (DLTs) and the recommended doses for further trials of docetaxel in combination with a 5-day continuous infusion of 5-fluorouracil (5-FU) in advanced or recurrent breast cancer patients who had been treated previously with at least one chemotherapeutic regimen, patients were treated with docetaxel as a 1-h infusion on day 1 followed by 5-FU as a continuous infusion on days 1 through 5 every 3-4 weeks. Three or six patients were assessed at the following escalating dose levels of docetaxel/5-FU per day: 40/150, 40/300, 50/300, 50/500 and 60/500 mg m(-2). Nineteen patients entered this trial, of whom 18 could be assessed for adverse event and therapeutic efficacy. The DLTs were neutropenia and diarrhoea. The MTDs were 60 mg m(-2) of docetaxel on day 1 and 500 mg m(-2) per day of 5-day continuous infusion of 5-FU. One of 18 patients achieved a complete response and eight achieved partial response (over all response rate: 50%). The recommended doses of docetaxel and 5-day continuous infusion of 5-FU for a phase II trial are 50 mg m(-2) and 500 mg m(-2) per day every 3 or 4 weeks.

Adult↗

PubMed1998

Angiotensin-converting enzyme gene polymorphism in Nepal.

It has recently been found that there were very few hypertensives in the inhabitants of one Nepalese village, even though their salt consumption, per capita, was as high as citizens in many western countries. To evaluate the genetic factors involved in this phenomenon, we studied whether they had a special genotype distribution of angiotensin-converting enzyme (ACE) gene I/D polymorphism, which was recently reported to be involved in salt sensitivity. One hundred and thirty-eight subjects were evaluated in Nepal. Only nine subjects (6.5%) in this population were hypertensives (over 140/90 mm Hg) while consuming 11 g salt/day, which confirmed the previous results. The distribution of genotypes and alleles of ACE gene I/D polymorphism was similar to that in the Japanese and Chinese, who had five-times more hypertensives while consuming almost as much salt as Nepalese, but significantly different from those in Caucasians. The present study reports, for the first time, the genotype distribution of ACE gene I/D polymorphism in Nepalese subjects. Furthermore, the results suggest ACE gene polymorphism may not be involved in the 'salt-resistance' in this population.

Aged↗

PubMed1998

Recurrent aciclovir-resistant herpes simplex in a child with Wiskott-Aldrich syndrome.

A boy with Wiskott-Aldrich syndrome suffered from thymidine kinase (TK)-altered and aciclovir-resistant herpes simplex virus type 1 (HSV-1) skin infections. He presented with severe herpes simplex around the left eye in March 1993 at the age of 8 years. HSV-1 strain TAS was isolated and was shown to be susceptible to aciclovir (50% inhibitory concentration (IC50) 0.23 microg/mL). He was treated with intravenous (i.v.) high dose aciclovir, 2 mg/kg per h, which produced an improvement. About 1 year later (May 1994), a severe herpes simplex infection appeared on his face, arm, genitalia, back and foot. Treatment with i.v. aciclovir, 2 mg/kg per h, was initiated, but the skin lesions did not improve. HSV-1 strain TAR was isolated and was shown to be resistant to aciclovir (IC50 36 microg/mL). HSV-1 TAR and TAS were susceptible to vidarabine (IC50 4. 4 and 2.9 microg/mL, respectively). The skin lesions were treated with i.v. vidarabine, 15-20 mg/kg per day, and healed satisfactorily. However, in March 1995, the patient again experienced a severe herpes simplex infection around the left eye. HSV-1 strain R95 was isolated and was shown to be resistant to aciclovir (IC50 36 microg/mL). Diminished sensitivity of HSV-1 TAR and R95 to aciclovir was associated with reduced viral TK activity and loss of aciclovir phosphorylation activity.

Acyclovir↗

PubMed1998

The adverse effect of commercial dentine-bonding systems on the skin of guinea pigs.

It was widely known that 2-hydroxyethyl methacrylate (2-HEMA) can cause contact dermatitis. Commercially available dentine primers and dentine bonding agents that contain 2-HEMA are widely used. The purpose of this study was to investigate the cumulative irritation and delayed hypersensitivity caused by commercial dentine bonding systems when applied to the skin of guinea pigs. We have concluded that almost no dentine bonding systems cause cumulative irritation, but some commercially available dentine bonding systems may produce delayed hypersensitivity.

Animals↗

PubMed1998

Acute myelogenous leukemia with monosomy 7, inv(3) (q21q26), involving activated EVI 1 gene occurring after a complete remission of lymphoblastic lymphoma: a case report.

A 42-year-old female with a mediastinal tumor and massive pleural effusion ws admitted to our hospital in June 1993. Biopsy revealed lymphoblastic lymphoma. She had no evidence of distant metastasis except pleural effusion. Bone marrow examination revealed a normal karyotype (46, XY). The patient had been progression-free for more than 1 year after achieving complete remission by induction, consolidation and maintenance therapy according to the standard chemotherapy and involved-field radiation for lymphoblastic lymphoma. From May 1996 progressive leukopenia and thrombocytopenia developed. The diagnosis of refractory anemia with excess of blasts (RAEB) was made. Subsequently, in November 1996, she developed acute myelogenous leukemia (AML), M4 type by FAB classification. The karyotype of MDS and AML clones involved inversion (3) (q21q26) and monosomy 7. The EVI 1 gene was examined and was proved to be rearranged and activated. This may be the first case among the therapy-related cases of MDS/AML reported whose karyotypes were followed and in which the mRNA expression of EVI 1 gene involved was directly proved in the leukemogenesis process of chemotherapy-induced secondary MDS and AML.

Chromosome Inversion↗

PubMed1998

Successful treatment by radiation and hormone therapy of isolated local recurrence of breast cancer 24 years after mastectomy accompanied by immune thrombocytopenia: a case report.

We report a case of isolated local recurrence of breast cancer, which was accompanied by idiopathic thrombocytopenic purpura (ITP) and benign monoclonal gammopathy that presented 24 years after the patient underwent mastectomy. A 72-year-old female patient with a chest wall tumor was referred to our hospital in November 1994. Twenty-four years previously she had surgically treated breast cancer, of which the pathology was scirrhous carcinoma. Needle biopsy of the tumor revealed tubular carcinoma, which is compatible with local recurrence of breast cancer. She had no evidence of regional lymph node involvement or distant metastasis. Hematological and serological examination revealed a low platelet count accompanied by M-proteinemia (IgG, kappa-type) and a mild increase in platelet-associated IgG. She was initially treated with extensive-field chest wall radiation (60 Gy), followed by systemic administration of tamoxifen. Complete local control of isolated local recurrence (LR) was achieved after radiation therapy (RT) and the patient has been progression-free for more than 2 years. Platelet count recovered gradually to a normal level after achievement of complete remission induced by radiation and tamoxifen. This may be the first case suggestive of a paraneoplastic syndrome of immune thrombocytopenia accompanied by local recurrence of breast cancer.

Adenocarcinoma↗

PubMed1998

Successful treatment with nedaplatin in patients with ovarian cancer that recurred after platinum-containing chemotherapy: report of two cases.

We report the successful treatment with nedaplatin of two cases of ovarian cancer that recurred after platinum-containing chemotherapy. A 52-year-old woman presented in June 1994 with massive accumulation of ascitic fluid. Pathological diagnosis of the specimen obtained at surgery in July 1994 was serous papillary adenocarcinoma of the ovary. In September 1995, approximately seven months after the completion of six cycles of CAP chemotherapy (cyclophosphamide, adriamycin and cisplatinum), she was referred to our hospital because of massive accumulation of ascitic fluid. The carbohydrate antigen 125 (CA-125) value was 485 U/ml. Cytologic study of her ascitic fluid was positive for adenocarcinoma cells. She did not respond to intravenous irinotecan and two cycles of intraperitoneal cisplatin. Nedaplatin 100 mg/m2 was administered. Complete response was achieved in September 1996 and continued for four months with a total of seven cycles of nedaplatin. The second case was a 60-year-old woman who was admitted to our hospital in December 1994 because of ascitic fluid. Diagnosis of ovarian cancer was based on an elevated level of CA-125 (1380 U/ml). Treatment with CAP and CC (cyclophosphamide and carboplatin) maintained a partial response for seven months. In August 1996, her disease progressed, although she was receiving CC therapy. Nedaplatin 100 mg/m2 was administered. Partial response was achieved again in November 1996 and continued for four months, with a total of five cycles of nedaplatin. In the light of our experience, treatment with nedaplatin in a patient with recurrent ovarian cancer might be worthwhile as palliative chemotherapy.

Adenocarcinoma, Papillary↗

PubMed1998

Ablation of Nrf2 function does not increase the erythroid or megakaryocytic cell lineage dysfunction caused by p45 NF-E2 gene disruption.

Maf recognition elements (MAREs or NF-E2 binding sites) have been shown to be vital for erythroid- and megakaryocyte-specific gene expression. Transcription factor NF-E2 is composed of p45, a large subunit belonging to the CNC family proteins, and a small Maf subunit, and is thought to activate transcription through its binding to MAREs in both the erythroid and megakaryocytic cell lineages. While p45 gene knockout mice exhibit thrombocytopenia due to abnormal terminal differentiation of megakaryocytes, and the mutant mice die of massive bleeding within a week after birth, anemia is not apparent in these animals. Disruption of the nrf2 gene, encoding another CNC family protein, results in no hematological abnormalities. We have therefore tested the hypothesis that Nrf2 might compensate for the p45 deficiency in erythroid lineage cells of p45-knockout mice, thereby masking the anticipated anemia. However, we failed to detect any greater failure in either erythroid or megakaryocytic cell development in Nrf2 plus p45 compound mutant mice as compared to with either individual homozygous mutation. These data suggest that p45 and Nrf2 may both be dispensable for hematopoietic cell development, and that other factors regulate erythroid- and megakaryocyte-specific gene expression through their required MAREs.

Anemia↗

PubMed1998

Activation of microvascular endothelial cells in active ulcerative colitis and detection of inducible nitric oxide synthase.

Endothelial nitric oxide (NO) synthase (NOS) that is expressed constitutively on microvascular endothelium is believed to be essential to systemic and/or local vascular integrity. Endothelial cells (ECs) were reported to express inducible NOS (iNOS) under some conditions iNOS expression indicates vascular activation. In this study we examined microvascular activation using ECs obtained from patients with ulcerative colitis (UC). We cultured ECs from the mesenteries of surgical UC patients and assayed NOS activity by NADPH-diaphorase cytochemistry and immunocytochemistry with an anti-iNOS antibody. Strong NOS activity was demonstrated on the cells from UC patients (5/5), whereas no activity was detected on the cells from cancer patients and human umbilical vein endothelial cells (HUVEC 0/5, 0/5). Strong iNOS activity was detected by immunoreaction, and large amounts of NO generated were detected by the conversion from [14C]arginine to [14C]citrulline (HUVEC 624+/-376 vs. EC-UC 1,492+/-233 dpm). These results suggest the possibility that ECs express spontaneous and continuous iNOS in active UC. They indicate a close relationship of vascular activation with the pathogenesis of UC.

Adult↗

PubMed1998

Seroprevalence of Helicobacter pylori infection in Nepal: low prevalence in an isolated rural village.

OBJECTIVE: To determine the seroprevalence of Helicobacter pylori infection in Nepal. DESIGN: H. pylori infection was identified using a specific and sensitive enzyme-linked immunosorbent assay for anti-H. pylori immunoglobulin G. STUDY POPULATION: Serum samples were collected from 1142 inhabitants (age range 4-93 years) from two villages: Kotyang, a rural isolated village (250 men, 210 women) and Bhadrakali, a suburban village of Kathmandu (334 men, 348 women). RESULTS: The overall prevalence of H. pylori infection was 56.8%, while significantly higher prevalence was found in the suburban village (Bhadrakali; 67.2%) than in the rural village (Kotyang; 41.5%). This difference was generally reflected by the infection rate in the 10-14-year-old age-group (Bhadrakali, 60% compared with Kotyang, 22.2%). The prevalence of infection significantly increased with age, while no significant difference was found in the prevalence of infection by gender. There was no difference in H. pylori positivity between individuals with and without upper abdominal symptoms in both villages. CONCLUSION: There was a significant regional difference in the seroprevalence of H. pylori within Nepal, which showed lower prevalence in an isolated rural village. This difference was mainly caused by the different acquisition rate in teenagers, thus indicating that the teenage lifestyle of this particular environment seemed to be the major determinant in the acquisition of H. pylori infection in the population.

Adolescent↗