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Biomedical subjects

S Doi

Publications and source records attributed to S Doi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Detection of fetal HPCs in maternal circulation after delivery.

BACKGROUND: Circulation of mature fetal blood cells in the maternal blood for a certain postpartum period has been verified, but detailed study of the fetal HPCs has not been reported. The objective of this study was to evaluate the frequency and clearance of these cells in the peripheral blood of puerperal women. STUDY DESIGN AND METHODS: PBMNCs from 15 puerperal women who gave birth to male infants were cultured in semi-solid medium containing hematopoietic stimulating factors. Colonies formed in the medium were individually characterized, collected, and subjected to PCR amplification of the SRY gene on Y chromosome to confirm fetal origin. RESULTS: The mean numbers of fetal progenitor cell colonies isolated per mL of maternal blood were 1.63, 2.48, 0.56, 0.12, and 0 on the day of delivery, at 4 days, 1 month, 6 months, and 1 year after delivery, respectively. There was no difference in the ratio of fetal versus maternal colonies between erythroid and granulocyte/macrophage lineages. CONCLUSION: The present study demonstrated that a significant number of fetal HPCs circulate in the maternal blood for a duration of at least 6 months after delivery.

Delivery, Obstetric↗
PubMed2001

Mercury adsorption onto pyrolyzed waste paper.

The ability of pyrolyzed waste paper to remove mercury from aqueous solutions by physicochemical adsorption was investigated. Defibered waste newsprint was pyrolyzed in a nitrogen atmosphere at 300 degrees C for 3 h. The pyrolysis residue showed high affinity to inorganic divalent mercury species. To investigate the adsorption characteristics, the factors affecting mercury adsorption were examined. The adsorbent was efficient in capturing mercury in neutral and basic media, although limited adsorption occurred in acidic media. The extent of the adsorption was also dependent upon the solution temperature and initial concentration of mercury in solution. The adsorption followed both the Langmuir and Freundlich isotherms.

Adsorption↗
PubMed2001

Endothelial nitric oxide synthase intron 4 polymorphism influences the progression of renal disease.

BACKGROUND/AIM: Nitric oxide is a potent regulator of intrarenal hemodynamics and may influence the renal function. We investigated whether polymorphism of intron 4 of the endothelial constitutive nitric oxide synthase (ecNOS) gene is related to the progression of chronic renal failure. METHODS: Polymorphism of ecNOS intron 4 was studied in 1,005 hemodialysis patients (710 with nondiabetic nephropathy and 295 with diabetic nephropathy) and was compared with the findings in 189 healthy subjects. ecNOS genotypes were determined by the polymerase chain reaction, followed by agarose gel electrophoresis. RESULTS: The frequencies of ecNOS4a/a, ecNOS4a/b, and ecNOS4b/b genotypes were, respectively, 0% (0/189), 13.8% (26/189), and 86.2% (163/189) in the control group; 1.7% (12/710), 22.1% (157/710), and 76.2% (541/710) in the nondiabetic nephropathy group, and 1.0% (3/295), 22.7% (67/295), and 76.3% (225/295) in the diabetic nephropathy group. The frequency of ecNOS4a (ecNOSa/a and ecNOSa/b) was significantly higher in both the nondiabetic group and in the diabetic group than in the controls (p = 0.0025 and p = 0.0438, respectively). CONCLUSION: There was a significantly higher frequency of the a allele of intron 4 in both nondiabetic and diabetic hemodialysis patients, so the polymorphism of intron 4 of the ecNOS gene may have a wide influence on the progression of renal disease.

Adult↗
PubMed2001

[High-dose therapy and peripheral blood stem cell transplantation for patients with aggressive non-Hodgkin's lymphoma remaining in initial remission: results of a feasibility study].

High-dose therapy with peripheral blood stem cell transplantation (HDT/PBSCT) was performed as one aspect of front-line therapy in patients with poor-risk aggressive non-Hodgkin's lymphoma (high-intermediate/high risk) according to the age-adjusted international prognostic index (aaIPI). Twenty-nine patients were enrolled in this study between November 1994 and March 1999. CHOP + etoposide (CHOP-E) was used as an initial chemotherapy and as a chemotherapy agent for the purpose of cell harvesting. Peripheral blood stem cells were harvested from 17 patients, and HDT with CEC (carboplatin, etoposide, cyclophosphamide)/PBSCT was performed in 11 patients. Eighteen patients dropped out, including five for whom CHOP-E therapy was ineffective and 5 who did not give consent for cell harvesting or HDT/PBSCT. CHOP-E therapy produced complete remission (CR) in 15 out of 26 patients (58%) after discounting the 3 who were ineligible among the 29 who were initially enrolled. The median observation period after PBSCT in the 11 patients who underwent HDT/PBSCT was 25 months (3 to 50 months), and the 3-year disease-free survival rate was 73%. No serious complications associated with the transplantation were observed. We were able to confirm the feasibility and safety of HDT/PBSCT as one form of front-line therapy for aggressive non-Hodgkin's lymphoma in patients under 60 years of age.

Adolescent↗
PubMed2001

[Prediction of the need for mechanical ventilation after transsternal thymectomy in patients with myasthenia gravis].

Between June 1992 and May 2000, transsternal extended thymectomy was performed for 70 patients with myasthenia gravis in our hospital. We were able to evaluate 64 of them in terms of prediction of the need for postoperative mechanical ventilation using the score systems reported by Leventhal et al., Kimura et al. and the criteria of Adachi et al.. For these systems, the rates of agreement between predictions and results were 85.9%, 82.8%, and 64.1%, respectively. The two former systems had some false negative cases (i.e., they predicted that ventilation would not be needed when in fact it was), but the last one gave no false negatives. We recommend Adachi's criteria for clinical safety. In our cases the patients whose value of %VC multiplied by FEV1.0% was less than 7,000 (Adachi's criterion is less in 8,300), especially, needed careful management with regard to respiratory crisis.

Adolescent↗
PubMed2001

[Complete cytogenetic response to interferon-alpha in a patient with chronic myelogenous leukemia undergoing hemodialysis].

We describe a complete cytogenetic response to interferon-alpha in a patient with chronic myelogenous leukemia undergoing chronic hemodialysis. Although IFN-alpha therapy has been applied to patients with chronic hepatitis C receiving hemodialysis, the pharmacokinetics of IFN-alpha in patients with poor renal function still remain unclear. In the present patient, the serum IFN-alpha concentration remained high even 48 hours after injection (42.9 IU/ml), and IFN-alpha was almost completely removed by hemodialysis (< 6 UI/ml). The patient was treated with IFN-alpha (3 x 10(6) IU, three times a week), and cytogenetic disappearance (0%) of the Ph-positive clone was confirmed 31 months after the start of therapy. Recombinant human erythropoietin (Epo) was used to treat anemia due to renal failure and IFN-alpha therapy. The anemia was controllable with Epo, and no adverse effect was observed.

Anemia↗
PubMed2001

[A case of hepatic metastasis of gastric cancer responding to TS-1, administered for two consecutive weeks and one week rest].

We have treated a case of hepatic metastasis of gastric cancer that has responded well to TS-1. The patient was a 68-year-old male, who underwent distal gastrectomy for gastric cancer. After surgery 5'-deoxy-5-fluorouridine (5'-DFUR) 800 mg/day was administered orally for two months. Grade 4 diarrhea appeared, so administration of 5'-DFUR was discontinued. Afterward the patient was followed with no chemotherapy. Liver metastasis (S6, 3 cm in diameter) was found at twelve months after surgery. 5'-DFUR (800 mg/day) was administered orally everyday. Grade 3 diarrhea appeared and metastasis showed NC after four weeks. 5'-DFUR administration was discontinued. Seventeen days later TS-1 (80 mg/day) was administered orally everyday for 2 weeks, followed by 1 week rest, as one course. Two courses of TS-1 administration resulted in a marked reduction of the liver metastasis, for a PR (75% reduction). After 3 courses, the liver metastasis showed CR. The patient is alive without recurrence after 12 courses. This TS-1 administration regimen was effective and tolerable for a patient with liver metastasis from gastric cancer.

Adenocarcinoma, Scirrhous↗
PubMed2001

[Influence of peplomycin on pulmonary function (PaO2, %DLco) in patients with oral carcinoma].

The pathogenesis of pulmonary fibrosis (PF) induced by bleomycin and its derivative, peplomycin (PEP), is insufficiently understood. To prevent PF and to administer PEP safely, we examined the influence of PEP on pulmonary function in 135 patients who underwent concomitant chemo (PEP + 5-FU)-radio (60Co) therapy and pulmonary function tests. In the inductive therapy, 5 mg of PEP was intramuscularly injected three times a week and a total of 41.6 +/- 14.3 mg was administered. Of the patients, 98 received oral azelastine hydrochloride (AZH, 4 mg/day) during the inductive therapy with the aim of prophylaxis of PF. The oxygen partial pressure in arterial blood (PaO2) only slightly decreased from 84.2 +/- 12.1 mmHg before treatment to 82.8 +/- 12.5 mmHg after treatment, while, carbon oxide diffusion (%DLco) decreased after treatment in most patients (p < 0.001, by paired t test) with mean values before treatment of 106.3 +/- 24.5% and after treatment 99.5 +/- 24.9%. The decrease of %DLco was associated with the dose of PEP until about 40 mg but further decreases of %DLco were not prominent. In the patients who underwent oral AZH, the decrease of %DLco weaker than that in patients without AZH: the decrease rates of %DLco in the former and latter were 4.3 +/- 9.4% and 14.1 +/- 15.9%, respectively. From the chest X-ray examination, mild PF was suspected in three patients but no advancement of PF or clinical symptoms were observed. From these results, it was concluded first that %DLco is more useful than PaO2 as the predisposing risk factor for PF, second that the decrease of %DLco depends on the dose of PEP until about 40 mg, third that AZH is expected to inhibit PEP-induced PF, and fourth that a small dose (20-40 mg) of PEP can be administered without inducing PF if care is exercised as to the patient's age, general condition and the value of %DLco in the use of PEP.

Aged↗
PubMed2001

[Inhaled corticosteroid therapy in childhood asthma].

Asthma has been recognized as a chronic inflammatory disorder of the airway. The early use of antiinflammatory agents, one of which is inhaled corticosteroids, is advocated in the treatment of chronic asthma. Beclomethasone dipropionate (BDP) is effective in childhood asthma. CD4 T-cell activation correlate with the values of the coefficient variation (CV) of peak expiratory flow (PEF) in asthmatic patients, suggesting that CV of PEF is a good marker for assessing not only the variability of airway obstruction but also the degree of airway inflammation. PEF monitoring is useful for better controlling asthma, because some patients treated with inhaled corticosteroid may still remain undertreated.

Administration, Inhalation↗
PubMed2000

Analysis of T wave changes by activation recovery interval in patients with atrial septal defect.

We examined the distributions of the activation recovery interval (ARI), which is correlated with the local action potential duration (APD), to clarify the origin of the repolarization changes in ASD. The ECGs, QRST isointegral maps and ARI isochronal maps of 21 children with ASD from 3 to 5 years old in age were studied in comparison with 21 age-matched normal children. A conventional and 87 unipolar body surface ECG were simultaneously recorded. The ARIs were determined from the first derivatives of the ECG waveforms. Abnormal ST-T patterns were observed in 11 of 21 ASD, but only in two normal children. The QRST maps of a split positive area pattern were seen in 15 of ASD but none of the normal. In the ARI maps, all the normal children exhibited a short-ARI area on the left and a long-ARI area on the right side of the chest. In 19 of ASD, the ARI distribution revealed a leftward extension of the long-ARI area on the anterior chest, a relative shortening on the right anterior chest, and a localized prolonged ARI on the left anterior chest. The results suggest that right ventricular (RV) volume overload in ASD produces a localized prolongation of the APD on the RV epicardium.

Child, Preschool↗
PubMed2000

Hopf bifurcations in multiple-parameter space of the Hodgkin-Huxley equations I. Global organization of bistable periodic solutions.

The Hodgkin-Huxley equations (HH) are parameterized by a number of parameters and shows a variety of qualitatively different behaviors depending on the parameter values. We explored the dynamics of the HH for a wide range of parameter values in the multiple-parameter space, that is, we examined the global structure of bifurcations of the HH. Results are summarized in various two-parameter bifurcation diagrams with I(ext) (externally applied DC current) as the abscissa and one of the other parameters as the ordinate. In each diagram, the parameter plane was divided into several regions according to the qualitative behavior of the equations. In particular, we focused on periodic solutions emerging via Hopf bifurcations and identified parameter regions in which either two stable periodic solutions with different amplitudes and periods and a stable equilibrium point or two stable periodic solutions coexist. Global analysis of the bifurcation structure suggested that generation of these regions is associated with degenerate Hopf bifurcations.

Axons↗
PubMed2000

Hopf bifurcations in multiple-parameter space of the hodgkin-huxley equations II. Singularity theoretic approach and highly degenerate bifurcations.

In the Hodgkin-Huxley equations (HH), we have identified the parameter regions in which either two stable periodic solutions with different amplitudes and periods and an equilibrium point or two stable periodic solutions coexist. The global structure of bifurcations in the multiple-parameter space in the HH suggested that the bistabilities of the periodic solutions are associated with the degenerate Hopf bifurcation points by which several qualitatively different behaviors are organized. In this paper, we clarify this by analyzing the details of the degenerate Hopf bifurcations using the singularity theory approach which deals with local bifurcations near a highly degenerate fixed point.

Axons↗
PubMed2000

Monoclonal antibody stains oligodendrocytes and Schwann cells in zebrafish (Danio rerio).

We prepared a monoclonal antibody that recognizes oligodendrocytes and Schwann cells in zebrafish. On immunoblots, the antibody mainly recognized three protein bands of 34 kDa in a membrane fraction from adult zebrafish brain. Medaka fish (Oryzias latipes) also possessed the same protein bands in a membrane fraction. The antibody did not stain neurons, but stained cells in fiber tracts and cranial and spinal nerves. In order to determine the nature of these cells, the staining pattern of the monoclonal antibody was compared with that of a myelin basic protein antiserum. Both antibodies stained oligodendrocytes and Schwann cells in fixed sections from the adult zebrafish. Both antigens were also co-localized in cultured glial cells. Taken together, these results indicate that the new monoclonal antibody recognizes myelinating glial cells in zebrafish and will be useful for the analysis of piscine glia.

Animals↗
PubMed2000

Association studies of 33 single nucleotide polymorphisms (SNPs) in 29 candidate genes for bronchial asthma: positive association a T924C polymorphism in the thromboxane A2 receptor gene.

Although intensive studies have attempted to elucidate the genetic background of bronchial asthma (BA), one of the most common of the chronic inflammatory diseases in human populations, genetic factors associated with its pathogenesis are still not well understood. We surveyed 29 possible candidate genes for this disease for single nucleotide polymorphisms (SNPs), the most frequent type of genetic variation, in genomic DNAs from Japanese BA patients. We identified 33 SNPs, only four of which had been reported previously, among 14 of those genes. We also performed association studies using 585 BA patients and 343 normal controls for these SNPs. Of the 33 SNPs tested, 32 revealed no positive association with BA, but a T924C polymorphism in the thromboxane A2 receptor gene showed significant association (chi2=4.71, P=0.030), especially with respect to adult patients (chi2=6.20, P=0.013). Our results suggest that variants of the TBXA2R gene or some nearby gene(s) may play an important role in the pathogenesis of adult BA.

Alleles↗
PubMed2000

Enhanced apoptosis of squamous cell carcinoma cells by interleukin-2-activated cytotoxic lymphocytes combined with radiation and anticancer drugs.

Induction of potent apoptosis is required in cancer therapy. We examined the combination effect of interleukin-2-activated lymphocytes (LAK cells) and anticancer drugs or gamma (gamma)-rays on the induction of apoptosis in an established oral squamous cell carcinoma cell line (OSC-3 cells). By pretreatment of OSC-3 cells with (137)Cs (5 Gy), 5-fluorouracil (5-FU) (0.5 microg/ml) or cis-dichlorodiammine-platinum (CDDP) (5 microg/ml), the activation of bid and caspase-3 by LAK cells was strongly increased and associated with an enhanced degradation of poly-(ADP-ribose) polymerase (PARP) and/or nuclear mitotic apparatus protein (NuMA) and the increased fragmentation of DNA. The LAK cell-enhanced caspase-3 activity in the pretreated OSC-3 cells was decreased to approximately 70% and 40% of the control by the addition of Z-AAD-CMK (a granzyme B inhibitor) and neutralising monoclonal antibody to Fas antigen (alphaFas-IgG), respectively. The combined treatment-induced DNA fragmentation was suppressed by approximately 20% and 30% of the control by the addition of Z-AAD-CMK and alpha Fas-IgG, respectively, in the co-culture system. While Ac-DEVD-CHO (a caspase-3 inhibitor) suppressed the DNA fragmentation levels to approximately half and this was similar to the amount of suppression that was obtained by the addition of both alpha Fas-IgG and Z-AAD-CMK. In addition, LAK cell-activated bid may have increased the intracellular reactive oxygen intermediates (ROI) level and induced a decrease of mitochondrial membrane potential. These influences by LAK cells were enhanced when OSC-3 cells were pretreated with each anticancer drug or (137)Cs. Furthermore, the increase of ROI by LAK cells was suppressed by alpha Fas-IgG and Z-AAD-CMK to approximately half the level of the control. These results indicate that anticancer drugs and gamma-rays prime squamous cell carcinoma cells to be susceptible to apoptosis by LAK cells, that LAK cell-induced apoptosis largely depends on the activation of caspase-3 by the Fas/Fas-ligand signal and granzyme B, and that LAK cells induce ROI in the target cells, which is largely mediated by Fas and granzyme B.

Antineoplastic Agents↗
PubMed2000

Regulation of Candida albicans growth and adhesion by saliva.

To examine the local regulation of oral Candida albicans growth, we examined non-stimulated and stimulated salivary flow rates (SFRs) and the C. albicans growth and adhesion inhibitory activities of saliva in 60 patients with oral candidiasis (divided into two groups: 25 patients with oral candidiasis only (group OC) and 35 patients with oral candidiasis and systemic diseases (group CS)) and 30 healthy control subjects. Both non-stimulated and stimulated SFRs in patients, especially in group CS; were decreased in comparison with those in the healthy control subjects. The levels of secretory immunoglobulin A (sIgA) in group OC and group CS and the lactoferrin level in group CS were decreased as compared with those in control individuals, although there were no differences in transferrin and total secretory component (SC) levels between the three groups. The secretion amounts (microg/min) of these proteins were statistically significantly decreased in the patients, especially in group CS. Saliva from the patients showed a lesser inhibitory effect on C. albicans growth and adhesion to HeLa cells than did saliva from the control subjects. In addition, polymorphonuclear leukocytes (PMNs) in patients' saliva generated smaller amounts of superoxide than did those in control subjects' saliva, and phagocytic and C. albicans killing activities were suppressed in the patients. These results indicate that the decreases in SFR, secretion of antimicrobial proteins in saliva, and salivary PMN activity are risk factors for oral candidiasis associated with aging and systemic diseases.

Adult↗