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Biomedical subjects

K Mitani

Publications and source records attributed to K Mitani.

At least 217 records · Page 12Linked to original sources
PubMed1988

Establishment of a human megakaryoblastic cell line (T-33) from chronic myelogenous leukemia in megakaryoblastic crisis.

A megakaryoblastic cell line, termed T-33, was established from the peripheral blood of a patient with Philadelphia chromosome-positive chronic myelogenous leukemia in megakaryoblastic crisis. T-33 cells have been maintained in RPMI 1640 medium containing 10% fetal calf serum in a single cell suspension with a doubling time of 24-36 h for over 2 years. Giemsa-banded karyotypes were female hyperdiploid with a modal chromosomal number of 51, all cells including Philadelphia chromosome. The cells showed strong positivity for periodic acid-Schiff and alpha-naphthyl acetate esterase, and weak for alpha-naphthyl butyrate esterase, but were negative for myeloperoxidase. Flow cytometric analysis of cell surface markers showed the existence of HLA-DR, MY-7, MY-9, and a platelet antigen (Yukb), and no markers for T- or B-lymphocytes. Most of the cells fixed with acetone were positive for Factor VIII, platelet glycoprotein IIb-IIIa, IIIa (Yukb), and Ib, but negative for glycophorin A and hemoglobin. Ultrastructural platelet peroxidase was demonstrated in 2-3% of cells and the percentage of positive cells increased up to 20% after the treatment with 12-O-tetradecanoylphorbol-13-acetate. The cells contained small dense granules negative for platelet peroxidase, their number increasing threefold after 12-O-tetradecanoylphorbol-13-acetate treatment. Such treated cells frequently showed a complex of the demarcation membrane in the cytoplasm. T-33 responded thrombin to exhibit calcium influx. This cell line may be useful for the study of the early stage of megakaryocytic differentiation in human megakaryopoiesis.

Antigens, Surface↗
PubMed1988

Palytoxin induces a nonselective cation channel in single ventricular cells of rat.

Palytoxin (PTX) causes a depolarization in every excitable tissue tested. We examined whether PTX induces a channel current, which might be responsible for the depolarizing action, in single ventricular cells from rat hearts using a patch-clamp technique. In cell-attached configuration, when PTX (30 pmol/l) was present in a patch pipette, a single channel current appeared, which was different from currents through known channels. When the major cation in the pipette was Na+, the amplitude of the unitary current at the resting potential level was 0.74 +/- 0.05 pA, the slope conductance was 9 pS and the reversal potential was 79 mV positive to the resting potential. The channel was little selective between cations because it was permeable not only to Na+ but also to K+, Cs+ and Li+ although it practically did not permit the passage of choline+, TEA+, Ba2+ and Ca2+. Thus PTX induces a novel, nonselective cation channel in cardiac cells, which may result in a depolarization.

Acrylamides↗
PubMed1988

Peripheral neuropathy with predominantly motor manifestations in a patient with carcinoma of the uterus.

An autopsy case of a 56-year-old woman who had carcinoma of the corpus uteri and peripheral neuropathy with predominantly motor manifestations is described. The neurological abnormalities included subacute weakness of the limbs and loss of deep reflexes, which improved after the surgical removal of the uterine carcinoma. Neuropathologically, peripheral nerves mainly presented features of axonal degeneration with a mild loss of myelinated fibres. Anterior horns of the spinal cord showed central chromatolysis of the motor nerve cells and many spheroids without neuronal loss. Axonopathy of peripheral nerves was considered to be the main pathological process in this paraneoplastic syndrome.

Carcinoma↗
PubMed1988

Right ventricular outflow obstruction secondary to post-infarction aneurysm: a possible new syndrome.

Two patients with extensive anterior myocardial infarction developed a hitherto unreported type of right ventricular outflow tract obstruction. A 71-year-old woman, who had had an acute infarction 10 years before, was admitted for sustained ventricular tachycardia. A loud ejection murmur was heard in the mid-precordium. The echocardiogram and left ventriculogram showed a septal aneurysm, with a systolic gradient of 21 mmHg between the right ventricular outflow tract and apex. The ejection murmur was detected in the outflow tract by intracardiac phonocardiography. The second patient was a 60-year-old man who had had an acute infarction at age 47. He was also referred because of ventricular tachycardia, and his clinical situation was almost the same as that of the first case. Our search of the literature failed to disclose any similar case with a loud ejection murmur confirmed by intracardiac phonocardiography to be due to an obstructive septal aneurysm.

Aged↗
PubMed1987

Vapor compression distiller and membrane technology for water revitalization.

Water revitalization for a space station can consist of membrane filtration processes and a distillation process. Water recycling equipment using membrane filtration processes was manufactured for ground testing. It was assembled using commercially available components. Two systems for the distillation are studied; one is an absorption type thermopervaporation cell and the other is a vapor compression distiller. Absorption type thermopervaporation able to easily produce condensed water under zero gravity was investigated experimentally and through simulated calculation. The vapor compression distiller was studied experimentally and it offers significant energy savings for evaporation of water.

Absorption↗
PubMed1986

A human Y-chromosome specific repeated DNA family (DYZ1) consists of a tandem array of pentanucleotides.

We have determined the complete nucleotide sequence of a 3564 bp EcoRI fragment which represents a major component of the human Y-chromosome specific repeated DNA family (DYZ1). Sequencing result showed a tandem array of pentanucleotides after five nucleotides were inserted or deleted at four positions. 229 out of the 713 pentanucleotides were TTCCA, and 297 were its single-base substituents. Southern hybridization analyses of male genomic DNAs showed that several endonuclease cleavage sites were located at intervals of 3.56kb in the DYZ1 locus. This indicates that the DYZ1 repeated DNA family evolved and expanded by unequal crossovers which occurred at distances of 3.56kb. As there is a uniformly distributed array of pentanucleotides on this locus, it is not a sequence homology that determines the distance of unequal crossovers. A higher order of chromatin structure may be involved in the determination of distance in unequal crossovers.

Chromosome Deletion↗