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Biomedical subjects

K Machida

Publications and source records attributed to K Machida.

At least 271 records · Page 15Linked to original sources
PubMed1984

Exogenous ATP induces electrical membrane responses in fibroblasts.

Mouse fibroblastic L cells responded to exogenous ATP (greater than or equal to 0.2 mM) with a transient hyperpolarization due to increased membrane permeability to K+. By contrast, intracellular injection of ATP (up to about 3 mM) produced no noticeable effects on the membrane potential. The effects of a non-hydrolysable analogue of ATP (AMP-PNP) were similar to those of ATP. After successive applications of ATP, the cell membrane became virtually unresponsive (desensitized). Extracellular ADP was also effective, but AMP or adenosine was not. Antazoline suppressed the ATP response. Thus, exogenous ATP and ADP appear to stimulate P2- purinoceptors . Similar responses to ATP (or ADP) were also observed in human normal diploid fibroblasts (Flow 1000 line).

Adenosine Diphosphate↗
PubMed1984

Granulocytic sarcoma presenting as a mediastinal tumor. Report of a case and cytological and cytochemical studies of tumor cells in vivo and in vitro.

An unusual case of granulocytic sarcoma in a 23-year-old man is reported. The patient initially presented with mediastinal tumor and was diagnosed clinically as having thymoma. The patient was treated by radiotherapy and surgical removal of the tumor. Histology of the excised tumor had been nondiagnostic because of extensive fibrous changes. Eight months later, the patient developed pleural effusion on the right, which soon was followed by blood and bone marrow pictures consistent with acute promyelocytic leukemia. In vitro culture of pleural effusion cells unexpectedly gave rise to a continuously growing peroxidase-positive myeloid cell line. Autopsy revealed the recurrent mediastinal tumor to be positive for intracytoplasmic naphthol AS-D chloroacetate esterase and lysozyme activity. From these findings, the patient retrospectively was diagnosed as having mediastinal granulocytic sarcoma, which terminated in pleural effusion and acute promyelocytic leukemia.

Adult↗
PubMed1984

Establishment of a new peroxidase-positive human myeloid cell line, PL-21.

A myeloid cell line, designated PL-21, was established from the peripheral blood of a patient with acute promyelocytic leukemia. The PL-21 cell line grew in single-cell suspension, with a doubling time of 48-64 hr, and consisted of promyelocytes with fine immature nuclei and prominent azurophilic granules in the cytoplasm. PL-21 cells were positive for peroxidase, naphthol AS-D chloroacetate esterase, and Sudan Black B staining. Under the usual culture conditions, a small proportion of these cells differentiated into mature granulocytes, and this differentiation was enhanced by the addition of dimethyl sulfoxide in the culture medium. PL-21 cells had receptors for the Fc portion of IgG and complement, intracytoplasmic lysozyme and phagocytic activity, but lacked Epstein-Barr virus-associated nuclear antigen. Chromosome analysis of this cell line revealed a human male polyploid karyotype with 13q+ and double minute chromosomes. This new myeloid cell line may provide useful material for the study of proliferation and differentiation of human leukemia cells.

Adult↗
PubMed1984

[Prospective study to assess the clinical efficacy of bone scintigraphy--methodology and some preliminary results].

The purpose of this study is to evaluate prospectively the value of radionuclide bone scans at the preoperative assessment of carcinomas of the breast and prostate carcinomas. Ten hospitals which are in or near Tokyo are participating in this study. For each patient under study, three kinds of sheet are filled by doctors. The first sheet named "preexamination diagnosis data sheet" is recorded before preoperative bone scan by attending physicians mainly. The second sheet named "postexamination diagnosis data sheet" is recorded after preoperative bone scan by nuclear medicine physicians who performed bone scintigraphy. The third sheet named "final diagnosis data sheet" is recorded after about a year of follow up period by attending physicians or nuclear medicine physicians. These data have been stored in a electric computer. Some preliminary analysis has been made by comparing the confidence level of diagnosis for bone metastasis before and after bone scintigraphy. In this report, methodology of the analysis and some results are described.

Adult↗
PubMed1983

Mutagenic activity of N-nitrosomethamphetamine and N-nitrosoephedrine.

The mutagenicity of N-nitrosomethamphetamine (NMA) and N-nitrosoephedrine (NEP), which were synthesized in our laboratory, was examined by the modified pre-incubation method of Ames assay using Salmonella typhimurium TA100 and TA98. Both nitroso compounds showed significant mutagenic activity in the presence of hamster S9.

Animals↗
PubMed1983

Urinary cyclic AMP and cyclic GMP in rats given three different concentrations of cadmium in the diet for one year.

Male and female weanling rats of the SPF Fisher strain were fed purified diets containing three different levels of cadmium (0.008, 0.3, 30 micrograms Cd/g feed). Urine was collected from each animal 1 year after the start of the experiment, and cyclic AMP and cyclic AMP in the urine were measured by radioimmunoassay. Urinary excretion of cyclic AMP and GMP changed in proportion to the intake of Cd. The ratio of cyclic AMP: cyclic GMP, which combined the changes of these two cyclic nucleotides, increased with Cd intake, and these relationships were statistically significantly different in males and females.

Animals↗
PubMed1983

Hypertrophy of the caudate lobe of the liver demonstrated with single photon emission CT.

A case of hypertrophy of the caudate lobe of the liver is reported in which transmission CT scanning strongly suggested the presence of a liver tumor. However, single photon emission CT using Tc-99m phytate showed that there was only caudate lobe enlargement with no evidence of a space-occupying lesion. The usefulness of single photon emission CT in such situations is discussed.

Child↗
PubMed1983

Computed tomography and scintigraphy of aldosteronoma. A comparative study.

Twelve cases of aldosteronoma were evaluated with CT and radioisotope scintigraphy to compare the diagnostic capability of both methods. All cases were diagnosed with scintigraphy, while six of 12 cases were diagnosed with CT. However, considering that nuclear imaging requires seven or eight days for evaluation, and the radiation dose is relatively high, it seems reasonable to perform CT scans initially in the localization of an aldosteronoma and to include scintigraphy in those cases in which aldosteronoma is not demonstrated by CT.

19-Iodocholesterol↗
PubMed1983

Combination chemotherapy for small cell carcinoma of the lung: evaluation of four-drug combination of cyclophosphamide, vincristine, methotrexate, and procarbazine.

Forty-one patients with small cell carcinoma of the lung were treated with a four-drug combination of cyclophosphamide, vincristine, methotrexate, and procarbazine. The response rate was 68% (28 responded among 41 patients), with 10 complete responses (24%) and 18 partial responses (44%). The median survival time from the initiation of chemotherapy was 11 months for patients with limited disease and 8 months for those with extensive disease. Patients who achieved complete response survived significantly longer than those who did not; the median survival time for complete responders was 14.5 months, compared to 8.5 months for partial responders and 6 months for non-responders. Myelosuppressive toxicity remained within acceptable limits, with 5% incidence of leukocytopenia (less than 1,000/microliter) and 7% incidence of thrombocytopenia (less than 50,000/microliter) following the first course of the regimen.

Adult↗