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Biomedical subjects

K Nagata

Publications and source records attributed to K Nagata.

At least 973 records · Page 54Linked to original sources
PubMed1983

Different responsiveness of hepatic and pulmonary microsomal mixed function oxidases to phenobarbital-type and 3-methylcholanthrene-type polychlorinated biphenyls in rats.

Inductive effects of pretreatments with a phenobarbital(PB)-type 2, 4, 5, 2', 4', 5'-hexachlorobiphenyl(HCB), a 3-methylcholantrene(MC)-type 3, 4, 5, 3', 4'-pentachlorbiphenyl(PenCB) and a mixed type polychlorinated biphenyl(PCB) mixture, Kanechlor(KC-)400 as well as PB and MC on the hepatic and pulmonary microsomal mixed function oxidases(MFOs) were examined and compared using male Wistar rats. Hepatic cytochrome P-450(448) content was increased 2- to 4-fold by pretreatment with all inducers tested, whereas the pulmonary content was slightly elevated only by the MC-type(MC and PenCB) and mixed type inducers. Benzphetamine(BZ) N-demethylase activity in the liver was strongly enhanced by the PB-type(PB and HCB) and mixed type inducers, but not affected by MC and suppressed by PenCB. Pulmonary BZ N-demethylation was not affected by pretreatments with the MC-type and mixed type inducers while both PB-type inducers decreased the activity. The PB-type inducers, showing a weak inducibility for aryl hydrocarbon hydroxylase(AHH) in the liver, also diminished the activity in the lung. In contrast, a marked enhancement of AHH activity in both organs was caused by pretreatment with the MC-type and mixed type inducers. AHH activity in both organs from PenCB-treated rats was highly sensitive to alpha-naphthoflavone but almost insensitive to SKF 525-A. These results strongly suggest that the pulmonary MFO in rats in inducible only with MC-type but not with PB-type PCB unlike the hepatic MFO.

Animals↗
PubMed1983

Monocyte function in idiopathic nephrotic syndrome in childhood.

The monocyte function of 112 specimens from 42 children with idiopathic nephrotic syndrome (INS) aged from 2 to 17 years was studied by the methods of nitroblue tetrazolium (NBT) reduction, phagocytosis of immunobeads (IB) and yeast cells, chemotaxis and acid alpha-naphthyl acetate esterase (ANAE) staining. The dissociation between phagocytosis and chemotaxis was observed in the fresh cases of steroid sensitive INS and in the cases of steroid non-sensitive INS. In the fresh cases of steroid sensitive INS, NBT reduction and phagocytosis were increased, but chemotaxis was decreased. In the cases of steroid non-sensitive INS, the phagocytosis of IB was decreased, but chemotaxis was increased. These findings suggest a different pathogenesis between steroid sensitive and steroid non-sensitive INS. The dissociation between phagocytosis and chemotaxis may be explained by the alteration of the surface receptors of monocyte and by lymphokines.

Adolescent↗
PubMed1983

Purification and characterization of galactosephilic component present on the cell surfaces of Streptococcus sanguis ATCC 10557.

Previous studies have indicated that a galactosephilic component present on the bacterial cell surfaces of Streptococcus sanguis ATCC 10557 may be responsible for the salivary glycoprotein-mediated binding of the cells. The purpose of this study was to investigate the purification and characterization of galactosephilic cell surface component from S. sanguis ATCC 10557. A galactosephilic component involving fibrils on the cell surfaces was isolated by the techniques of freezing and thawing, and purified by an affinity chromatography on beta-D-galactose binding-Bio-Gel P-2 followed by gel filtrations on Bio-Gel P-150 and on Bio-Gel P-30. Both disk gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the purified product was homogeneous. The isoelectric point of the purified sample was 8.5 to 9.0. Treatment of the purified sample with pronase E reduced remarkably either the hemagglutinating activity or the precipitation reaction with proline-rich glycoprotein in human parotid saliva, suggesting that the active site may be present on the peptide moieties. When sugar specificity was examined by hemagglutination-inhibition test, D-galactose was the strongest inhibitor. The results of this study suggest that the galactosephilic component may be a bacterial lectin.

Cell Wall↗
PubMed1983

[Effects of a combination chemotherapy "VEMA" consisting of vincristine, cyclophosphamide, methotrexate and ACNU in the treatment of small cell bronchogenic carcinoma].

A combination chemotherapy "VEMA" consisting of vincristine (VCR), cyclophosphamide (Endoxan, EX), methotrexate (MTX) and nimustine (ACNU) has been carried out for the treatment of small cell bronchogenic carcinoma since September, 1978. "VEMA" regimen consists of VCR 1.3 mg/m2 iv push on day 1, EX 500 mg/m2 iv infusion on day 1 and 2, MTX 28 mg/m2 iv push on day 1, 2 and 3, and ACNU 67 mg/m2 iv push on day 3. This dose schedule was repeated every 3 to 4 weeks. The regimen was given to 14 patients and 12 patients were evaluable. In the 12 evaluable cases, 2 case of complete response (CR), 7 cases of partial response (PR) and 2 cases of effusion effective were obtained. Response rate of CR + PR was 90%. Response rate including CR, PR and effusion effective was 91.7%. The major clinical toxicity of "VEMA" therapy was bone marrow suppression. Other side effects were anorexia, nausea, vomiting, alopecia and stomatitis: etc; however, these side effects were not life threatening to terminate "VEMA" therapy. In conclusion, "VEMA" regimen is a new potent combination chemotherapy in the treatment of small cell bronchogenic carcinoma.

Adult↗
PubMed1983

[Phase II study with methyl-6[[[2-chloroethyl) nitrosoamino] carbonyl] amino]-6-deoxy-alpha-D-glucopyranoside (MCNU) in hematological malignancies].

A total of 117 cases with hematological malignancies were treated with MCNU at doses of 70-100 mg/m2. Following are the results obtained. 1. MCNU showed a marked depression of cells in the cases with CML, polycythemia vera and thrombocythemia. The low level of cells was maintained for 2 to 7 months. 2. A good response was observed in several cases with blastic crises of CML. 3. No response was observed in two cases with acute leukemia. 4. Although a fair response was observed in several cases with malignant lymphoma or multiple myeloma, moderate bone marrow suppression was observed in a majority of the cases.

Adult↗
PubMed1983

[Pharmacokinetics and a phase I study of tegafur-uracil enterogranules in cancer patients].

UFT-E, enterogranules of tegafur-uracil (at molar ratio of 1: 4) was developed in order to minimize GI toxicity of UFT. Pharmacokinetic study after single oral administration of 300 to 1200 mg of UFT-E was carried out in cancer patients measuring tagafur, uracil and 5-FU levels in serum, normal tissue and tumor tissue using HPLC and GC-mass. In the all doses studied, curves of serum tegafur after administration of UFT-E were consistently higher than those of uracil and 5-FU. Peak 5-FU levels were observed at 2-4 hours after administration of UFT-E. Maximum 5-FU levels ranged 0.1-3.0 mcg/ml and were variable in each patient even at the same doses. The serum 5-FU level was correlated with tegafur and uracil levels, especially with the latter. The curves of serum 5-FU of UFT-E were different from those of UFT, and the peak time of UFT-E occurred 2 or 3 hours later than that of UFT and the decrease of 5-FU level was slower. The concentrations of 5-FU in tumor tissue (T) were observed in most of the cases compared with those in normal tissue (N) (T/N ratio of more than 2.0 was observed in 16/23 patients), especially in the patients received higher doses of UFT-E and in the patients with GI cancers. In the phase I study of oral daily consecutive administration of UFT-E in 23 cancer patients, the GI side effects such as anorexia, nausea, vomiting and diarrhea, were observed in 5 out of 23 patientsr.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗