Search PubMed⌕ Search

Biomedical subjects

T Koizumi

Publications and source records attributed to T Koizumi.

At least 19 recordsLinked to original sources
PubMed2006

Troglitazone inhibits cell growth and induces apoptosis of B-cell acute lymphoblastic leukemia cells with t(14;18).

Peroxisome proliferator-activated receptor-gamma (PPARgamma), a member of the nuclear receptor superfamily, has been detected in several human leukemia cells. Recent studies reported that PPARgamma ligands inhibit cell proliferation and induce apoptosis in both normal and malignant B-lineage cells. We investigated the expression of PPARgamma and the effects of PPARgamma ligands on UTree-O2, Bay91 and 380, three B-cell acute lymphoblastic leukemia (B-ALL) cell lines with t(14;18), which show a poor prognosis, accompanying c-myc abnormality. Western blot analysis identified expression of PPARgamma protein and real-time PCR that of PPARgamma mRNA on the three cell lines. Troglitazone (TGZ), a synthetic PPARgamma ligand, inhibited cell growth in these cell lines in a dose-dependent manner, which was associated with G(1) cell cycle arrest and apoptosis. We also found this effect PPARgamma independent since PPARgamma antagonists failed to reverse this effect. We assessed the expression of c-myc, an apoptosis-regulatory gene, since c-myc abnormality was detected in most B-ALL cells with t(14;18). TGZ was found to dose-dependently downregulate the expression of c-myc mRNA and c-myc protein in the three cell lines. These results suggest that TGZ inhibits cell growth via induction of G(1) cell cycle arrest and apoptosis in these cell lines and that TGZ-induced apoptosis, at least in part, may be related to the downregulation of c-myc expression. Moreover, the downregulation of c-myc expression by TGZ may depend on a PPARgamma-independent mechanism. Further studies indicate that PPARgamma ligands may serve as a therapeutic agent in B-ALL with t(14;18).

Adolescent↗
PubMed2005

Trial of remote telemedicine support for patients with chronic respiratory failure at home through a multistation communication system.

To create and test a multistation telemedicine support system, three remote locations were connected: the homes of two patients with chronic respiratory failure, the hospital of the attending physician, and the hospital of the pulmonary specialist. Real-time connections were set up between the three locations. Medical history and biologic variables were noninvasively recorded, including blood pressure, arterial oxygen saturation, three-lead electrocardiogram, and end-tidal carbon dioxide. Both physicians shared in these data real-time. If necessary, the respiratory specialist could provide medical advice to the attending physician based on the patient's condition. The trial program resulted in the same information being exchanged remotely using the multi-station telemedicine system that would be exchanged in a direct, face-to-face encounter. This result, together with the improvement in quality of life and the establishment of appropriate treatment and cooperation between the respiratory specialist and attending physician, suggests our system can be considered useful and promising for further use.

Aged↗
PubMed2005

Phase I trial of nedaplatin and paclitaxel for patients with non-small cell lung cancer.

A phase I study was conducted to evaluate the maximum tolerated dose and feasibility of combination with nedaplatin (NDP) and paclitaxel in patients with non-small cell lung cancer (NSCLC). Fifteen patients under 75 years old, with unresectable NSCLC who had not previously received chemotherapy or radiotherapy, with a performance status of 0-1, were enrolled. The dose escalation levels (NDP/Paclitaxel; mg/m2 day 1) were 80/150 (level 1), 80/180 (level 2), 90/180 (level 3) and repeated every 28 days. All patients receiving level 3 had dose-limiting toxicity. One patient developed grade 4 neutropenia with infection, two had incomplete recovery of neutropenia and thrombocytopenia by the 28th day after the first cycle of chemotherapy. Non-hematologic toxicities, including nephrotoxicity, nausea/vomiting, alopecia, and hypersensitivity reaction, were tolerated. Three of the 15 patients achieved partial responses. We concluded that the recommended dose was paclitaxel 180 and NDP 80 mg/m2 due to the hematologic toxicity.

Adult↗
PubMed2005

Airway inflammation during stable and acutely exacerbated chronic obstructive pulmonary disease.

The aim of this study was to clarify the mechanism of increased airway inflammation during an acute exacerbation. A total of 68 chronic obstructive pulmonary disease patients in a stable phase were enrolled and followed-up for 2-3 yrs. Inflammatory cells were analysed, and interleukin (IL)-8, neutrophil elastase, eotaxin, tryptase and RANTES (regulated on activation, normal T-cell expressed and secreted) were measured in sputum, both in a stable phase and during acute exacerbation. Out of 68 patients, 30 (unstable group) developed an acute exacerbation and expectorated adequate sputum during exacerbation. Thirty-two patients (stable group) did not develop any exacerbation for 2-3 yrs. The number of neutrophils, lymphocytes and eosinophils, and the levels of IL-8, eosinophil cationic protein (ECP), eotaxin and tryptase in sputum obtained from patients in both groups during the stable phase were significantly higher than those from healthy nonsmokers. There were no significant differences in cell analysis and biomarkers between the two groups, but patients in the unstable group showed more severe airflow limitation. In the unstable group, total cells, lymphocytes, neutrophils and eosinophils, and IL-8, neutrophil elastase, ECP and RANTES levels were significantly increased during an exacerbation from values in a stable phase. These findings suggest that exacerbation of chronic obstructive pulmonary disease may associate with additional increases in airway inflammation mediated by neutrophils, lymphocytes, eosinophils, interleukin-8 and RANTES.

Acute Disease↗
PubMed2005

Clinical usefulness of CEA-mRNA determination in minor effusion.

Malignant pleural effusion of lung cancer is an important prognostic factor, even in minor effusions. Previous studies reported that cytological examination could not detect malignant cells in pleural dissemination cases. Therefore, we used real-time PCR as a more sensitive test to detect malignant cells. The subjects were selected from 132 primary lung cancer patients and 8 benign tumor patients as negative control. These subjects had no apparent pleural effusion or distant metastasis. All subjects were negative on cytological examination and without exfoliation evidence. The follow-up duration was 18.1 +/- 7.1 months (mean +/- SD). In the real-time PCR, the CEA-mRNA and GAPDH-mRNA parameters were measured simultaneously, and the CEA-mRNA ratio was obtained as normalized values of CEA-mRNA divided by GAPDH-mRNA. The CEA-mRNA ratio in our study was correlated with lymph node metastasis (N-factor: p = 0.0948) and lymphatic invasion (Ly-factor: p = 0.0520). Using a proportional hazard model, with recurrence or death as terminal point, the CEA-mRNA ratio affected the recurrence risk by 1.920 (95% CI: 1.104-3.340) in Stage 1a. Using log rank testing, we found significant differences in the recurrence rate between the CEA-mRNA-positive and -negative cases (p = 0.0039) at cut-off point 0.1.

Base Sequence↗
PubMed2004

Quantitative nested reverse transcriptase PCR vs. real-time PCR for measuring AML1/ETO (MTG8) transcripts.

A quantitative nested reverse transcriptase polymerase chain reaction (QN-RT-PCR) method was developed using a plasmid cDNA containing the AML1/ETO (MTG8) fusion transcript from Kasumi-1 cells, an acute-myelogenous leukemia cell line with the t(8;21) translocation. In this method, the plasmid was detectable at a concentration of 10(-17) m. The fusion transcript in a mixture of 10(7) Rice94 (Burkitt lymphoma cell line) cells containing two Kasumi-1 cells was detectable at 10(-17) m. In a previously published real-time PCR method, the plasmid containing the fusion transcript was detectable at 10(-16) m or higher, and 20 or more Kasumi-1 cells were detectable in 10(7) Rice94 cells. Thus, this QN-RT-PCR method is more sensitive than the real-time PCR. When the same samples were examined by real-time PCR and our QN-RT-PCR method, in one patient in clinical remission after chemotherapy and allogeneic-bone marrow transplantation (BMT), the transcript was detected by QN-RT-PCR 60 days prior to hematological relapse, in contrast to 10 days before hematological relapse by real-time PCR. The transcript level was below 10(-17) m (undetectable) with this QN-RT-PCR in patients in clinical remission after chemotherapy and BMT, while it was 10(-15)-10(-16) m in patients in clinical remission after chemotherapy alone. The quantitative difference of the transcript level in minimal residual disease (MRD) between these two different types of clinical remission was estimated to be at least 10(2)-fold. This QN-RT-PCR method is useful for predicting hematological relapse and for quantitatively estimating MRD in different types of clinical remission.

Cell Line, Tumor↗
PubMed2002

Effects of an eosinophil chemotaxis inhibitor, TAK-661, on antigen-induced asthmatic responses in allergic sheep.

Eosinophils have been shown to play a role in allergen-induced airway responses. The aim in this study was to examine the effects of TAK-661, a newly developed product as a specific inhibitory agent of eosinophil chemotaxis, on antigen-induced asthmatic responses in allergic sheep model. Seven Ascaris-sensitive, "dual-respondent" allergic sheep were provocated by an Ascaris suum antigen or phosphate-buffered saline 2 hrs after intra-stomach administration of TAK-661 or a placebo. Pulmonary resistances were measured throughout the experiment, and airway responsiveness to methacholine, bronchoalveolar lavage (BAL), and histological examination were performed 8 hrs after the antigen challenge. Antigen provocation induced dual-phase bronchoconstriction, eosinophilia in BAL and eosinophil infiltration into the airway wall, and an increase in airway responsiveness in placebo-treated sheep. The administration of TAK-661 significantly reduced the bronchoconstriction during the late phase, along with the inhibition of eosinophilia in BAL and the eosinophil infiltration into the airway wall. TAK-661 had a tendency to reduce early-phase bronchoconstriction and airway hyperresponsiveness, but there were no significant differences. These findings suggest that the eosinophil accumulation into the airway induced by antigen provocation may contribute to the development of late-phase bronchoconstriction, however, the development of airway hyperresponsiveness during late asthmatic response may not always be due to only eosinophilic inflammation in the airway.

Animals↗
PubMed2002

Choledocholithiasis in an infant of extremely low birthweight.

A five-month-old infant of extremely low birthweight with choledocholithiasis is reported. A baby girl was delivered at 26 weeks gestation as a second twin, weighing 834 g. At 30 days of age, gallbladder stones were found by routine ultrasonography. She had vomiting at 157 days of age. Ultrasonography revealed calculi in the gallbladder and a dilated common bile duct. She was conservatively treated with scopolamine, antibiotics and dehydrocholic and ursodeoxycholic acids, and the calculi had disappeared by 189 days of age. Although conservative treatment succeeded in this patient, further cases should be analysed to establish how to manage choledocholithiasis in such small infants.

Dehydrocholic Acid↗
PubMed2002

Early-onset group B streptococcal sepsis in a preterm infant with Kostmann syndrome.

UNLABELLED: A preterm infant died of group B streptococcal sepsis 7 h after birth. The infant's complete blood count showed total agranulocytosis. Histopathology of the major organs showed significant bacterial invasion without infiltration of polymorphonuclear leucocytes. Examination of the bone marrow revealed normal cellularity of the granulocyte precursors with arrested maturation. These findings are consistent with Kostmann syndrome. CONCLUSION: It is suggested that in patients with deteriorating early-onset infection, underlying congenital abnormalities in host defence, such as Kostmann syndrome, should be considered.

Age of Onset↗
PubMed2001

T-cell receptor gammadelta T-cell leukemia with the morphology of T-cell prolymphocytic leukemia and a postthymic immunophenotype.

T-cell prolymphocytic leukemia (T-PLL) is a postthymic T-cell neoplasm with a characteristic morphology and heterogeneous immunophenotype. Most cases of T-PLL express membrane T-cell receptors (TCRs) of the alphabeta phenotype. We experienced a 30-year-old man suffering from TCRgammadelta T-cell leukemia with morphology compatible to T-PLL with a postthymic phenotype. He was admitted with skin eruption and pancytopenia. Peripheral blood and bone marrow were occupied with medium-sized lymphocytes, which had moderately condensed chromatin with a single nucleolus and sparse, nongranular basophilic cytoplasm. The immunophenotype was CD1a-, CD2-, CD3+, CD4-, CD5+, CD7+, CD8-, and terminal deoxynucleotidyl transferase negative. Hepatosplenomegaly was absent. He was diagnosed as having T-PLL and was treated with combination chemotherapy. Six months later the leukemic cell became chemoresistant. Although the patient showed transient improvement in response to pentostatin, he died 13 months after the diagnosis. To our knowledge, this is the first case of T-PLL with a TCRgammadelta phenotype.

Adult↗
PubMed2001

Effect of pH on skin permeation enhancement of acidic drugs by l-menthol-ethanol system.

The effect of pH on the skin permeation enhancement of three acidic drugs by the l-menthol-ethanol system was investigated. The total flux of acidic drugs from the system remarkably varied over the pH range 3.0-8.0, and the permeation enhancement factor depended on the system pH and drug. A skin permeation model, which consists of two permeant (unionized and ionized) species, two system (oily and aqueous) phases, and two permeation (lipid and pore) pathways, was developed. The assumptions were made that only the unionized species can distribute to the oily phase and transport via the lipid pathway. The model explained the relationship between the concentration of drug in the aqueous phase and system pH. The skin permeability data were also described by the model and permeability coefficients corresponding to the physicochemical properties of permeant were calculated for the lipid and pore pathways. The model simulation showed that the permeation of acidic drugs occurred from the aqueous phase and the oily phase acted as a reservoir. Whether the total flux increased with increase of pH was dependent on the lipophilicity of drug. These results suggest that the pH of l-menthol-ethanol system should be given attention to elicit the maximum permeation enhancement.

Animals↗
PubMed2001

Mechanistic modeling of drug release from chitosan coated tablets.

A mechanistic model for drug release from tablets coated with chitosan was derived, assuming that: (1) core tablets are spherical and the drug dissolution is diffusion dependent. (2) In order for the drug release to occur, dissolution medium penetrates through the coated film and leaches out the drug through the film and the lag-time, t(lag) is set for these processes. (3) The coated film itself dissolves and becomes thinner with time. (4) After the film has completely dissipated and the undissolved core tablet becomes naked, drug release proceeds just as the spherical core tablet. Drug release rate was given as a differential equation. Model adaptation was carried out to the release data of propranolol hydrochloride tablets coated with chitosan and kept in different storage conditions. The goodness-of-fit of our model was better than any other conventional equations tested and estimated model parameters were informative.

Chitin↗