Search PubMed⌕ Search

Biomedical subjects

I Tanaka

Publications and source records attributed to I Tanaka.

At least 451 records · Page 25Linked to original sources
PubMed1987

[A case of multiple gastric carcinoids with argyrophil cell hyperplasia].

A case of multiple gastric carcinoid tumors (CT) with diffuse hyperplasia of argyrophil cell in a 47-year-old female is reported. On gross examination, five polypoid CT, the largest measuring 0.8 cm in the diameter, were found in the gastric body. Argyrophil cell micronests (ACM) in the deep mucosa were found to be distributed throughout the stomach. ACM arise from the proliferated argyrophil cells within the mucosal gland by isolation, budding, replacing and developing into CT. Some of these argyrophil cells in the CT and ACM showed only serotonin immunoreactivity. We have identified electron microscopically EC cells and ECL cells with vacuolated, eccentric electron dense granules, 130-360 nm in diameter.

Carcinoid Tumor↗
PubMed1987

[Single-agent trial with epirubicin in hematological malignancies].

Twelve patients with hematological malignancies were treated with epirubicin and ten patients were evaluable. One out of our four patients with ALL, who had a previous therapy of anthracycline, achieved a partial remission (PR: 25%). In two patients with AML, remission was not obtained. Of four patients with NHL, one with B-cell lymphoma achieved complete remission (CR) and one with ATLL partial remission (CR + PR: 50%). Stomatitis was observed as a major side effect in three patients with acute leukemia and in one with NHL. In conclusion, our trial seems to show the efficacy of epirubicin in lymphoid malignancies.

Acute Disease↗
PubMed1987

Low dose cytosine arabinoside therapy in myelodysplastic syndrome and acute myeloid leukemia.

Four patients with acute myeloid leukemia (AML) and three with myelodysplastic syndrome (MDS) were given low dose cytosine arabinoside (Ara-C) therapy. One patient with de novo AML and two patients having refractory anemia with excess of blasts (RAEB) achieved responses. Although the responses lasted for only a short duration (2-3 months), the therapy was well tolerated and not accompanied by severe complications, while severe cytopenia was a frequent side effect with transfusions being necessary in most patients. This therapy could be clinically effective for certain types of AML and MDS (especially RAEB and RAEB in transformation).

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

[Phase II study of a new nitrosourea derivative, MCNU, in tablet form. Takai Blood Cancer Study Group].

A phase II study of the oral agent methyl 6-[3-(2-chloroethyl)-3-nitrosoureido]-6-deoxy-alpha-D-glucopyranoside (MCNU tablet) for myeloproliferative disorders was performed. Fifty-two patients were treated with MCNU tablets and 43 patients were evaluated for clinical effects and 45 for adverse effects. The standard regimen was as follows; oral administration of 50mg (one tablet)/body/day every 4-6 days was considered as one course, and this was repeated at 6-8-week intervals if possible, with certain modifications according to dosage, period of administration and dose interval wherever necessary. Of 16 patients with chronic myelogenous leukemia (CML) in the chronic phase, 13 achieved complete remission (CR), and 3 achieved partial remission (PR). The overall response ratio was 100%. Rapid reduction of leucocytes was detected within two weeks. One patient with CML in blast crisis achieved PR (100%). Of 15 patients with polycythemia vera, 13 showed an excellent effect (87%), and 1 a moderate effect (6.7%), the overall response ratio being 93%. In essential thrombocythemia, an excellent effect (70%) was obtained in 7 of 10 patients. One patient with myelofibrosis showed an excellent effect (100%). Nausea & vomiting (33%) and anorexia (13%) were major adverse effects, but these symptoms were observed only transiently. Liver dysfunction was also seen in 8.9% of patients, but no patient showed severe manifestations. Our study supports the contention that MCNU tablet is a useful agent against myeloproliferative disorders.

Administration, Oral↗
PubMed1987

The structure of Bowman-Birk type protease inhibitor A-II from peanut (Arachis hypogaea) at 3.3 A resolution.

The structure of Bowman-Birk type protease inhibitor (A-II from peanut) is described at 3.3 A resolution. The molecules form a tetramer with 222 local symmetry in our crystals. Each monomer has an elongated shape with approximate dimensions of 45 X 15 X 15 A and consists of two distinct domains. The three-dimensional structures of the two domains are similar and are related by the intramolecular approximate twofold rotation axis. The two independent protease binding sites protrude from the molecular body on opposite sides. A scheme for the molecular evolution of the double-headed Bowman-Birk type protease inhibitors is proposed, based on the three-dimensional structure.

Arachis↗
PubMed1986

Insulin-like growth factor I stimulates growth in normal growing rats.

The scarcity of purified somatomedin/insulin-like growth factor (SM/IGF) has prevented investigation of the mechanisms of SM/IGF action. Recently insulin-like growth factor I (IGF-I) has been synthesized by recombinant DNA technology. The availability of large quantities of the biosynthetic IGF-I made it possible to study its effects by administering 120 micrograms/day via s.c. implanted minipump to rats for 7 days. After this 7 day administration of IGF-I, the body weight increased to 197.6 +/- 3.5% of initial values; the value was significantly greater than that of the control (179.4 +/- 3.7% of initial values, P less than 0.01). The body length and tibial epiphyseal width in IGF-I-treated rats were also significantly increased over those of control rats. The weights of kidneys, liver, testes and pituitary in IGF-I-treated rats were greater than those in control rats as well. These results provide a first demonstration that IGF-I stimulates growth in normal rats in vivo, and suggest that IGF-I might be useful in the treatment of growth retardation.

Animals↗
PubMed1986

Heterogeneity of factor IX BM. Difference of cleavage sites by factor XIa and Ca2+ in factor IX Kashihara, factor IX Nagoya and factor IX Niigata.

Abnormal factor IX was isolated from the plasma of a patient with hemophilia B Kashihara and two patients with hemophilia BM. The F.IX was purified to homogeneity by using monoclonal anti-F.IX-Sephrose, heparin-Sepharose and DEAE-Sephadex A-50 affinity chromatography successively. The isolated proteins have the same molecular weight and the same mobility on crossed immunoelectrophoresis as normal F.IX. The limited proteolysis of purified proteins was induced by F.XIa/Ca2+ or by RVV-X/Ca2+. A time course study showed that F.IX Nagoya seemed to be cleaved by neither F.XIa nor RVV-X, F.IX Kashihara was cleaved partially by F.XIa but not by RVV-X, and that F.IX Niigata was cleaved completely at the rate similar to normal F.IX, though the resultant product of F.IX Niigata did not show any F.IXa activity. These results favored the view that hemophilia B+ or BM is a heterogeneous disorder.

Antigens, Heterophile↗
PubMed1986

A new generator for producing propylene oxide vapor in inhalation toxicity studies.

A vapor generator for propylene oxide which has a high vapor pressure (boiling point: 33.9 degrees C, vapor pressure: 442 mmHg at 20 degrees C) was developed. For inhalation toxicity studies, until now, there have been few generators capable of producing a low concentration of vapor from a liquid with high vapor pressure. In this study, the vapor was generated from the surface of a sintered sphere of glass beads filled with propylene oxide. The sphere was hung in a glass column which was installed in a Dewar vessel chilled with ice. The liquid of propylene oxide was automatically supplied from a reservoir to the sphere by capillary suction pressure caused by the evaporation of the liquid from the surface. The concentration of the generated vapor was able to be kept constant over a long period by using a carrier gas dried by a silica gel column, and could be regulated by the flow rate of carrier and dilution gas, and the sphere diameter. This generator is useful for the investigation of health effects of propylene oxide in inhalation toxicity studies.

Environmental Exposure↗
PubMed1986

Release of immunoreactive atrial natriuretic factor from rat hypothalamus in vitro.

Atrial natriuretic factor (ANF) had been found in brain tissues. Its role and the mechanisms by which it is produced and functions in the brain were not clear. We have initiated in vitro studies to find whether it is released from brain tissue and to elucidate the mechanism of its release. ANF was found to be released from rat hypothalamus by a depolarizing concentration of potassium and by a calcium-dependent mechanism. The ANF released was found to be predominantly a low molecular weight form. A small amount of high molecular weight form was also released. These results suggest that ANF produced in brain tissues is released, by a depolarization-induced and calcium-mediated mechanism, presumably from neuronal cells.

Animals↗
PubMed1986

Ethylene oxide neuropathy in rats. Exposure to 250 ppm.

In Wistar rats subjected to a 6-h exposure to ethylene oxide at the concentration of 250 parts per million once, 5 times a week for 9 months, histopathologic studies of myelinated fibers of the proximal sural, distal sural and peroneal nerves and of the fasciculus gracilis at the 5th thoracic and 3rd cervical segments of the spinal cord were performed to observe whether ethylene oxide of such a concentration would lead to degeneration of primary sensory neurons. Throughout the study, no definite abnormality of the gait or posture was observed in both control and test rats. Qualitative histologic studies disclosed preferential distal axonal degeneration of myelinated fibers in both sural nerves and gracile fascicles in the test rats, although the extent of the distribution and the severity of the degenerative findings were variable. Such findings are consistent with mild axonal degeneration found among patients suffering from ethylene oxide toxicity. Therefore, in rats, exposure to 250 ppm ethylene oxide produces central-peripheral distal axonal degeneration of primary sensory neurons.

Animals↗
PubMed1986

Pulmonary deposition and clearance of a coal fly ash aerosol by inhalation.

Wistar male rats were exposed to coal fly ash aerosols at average exposure concentration of 10.4 mg/m3 for 7 hr/day, 5 days/week for 1 month. Some rats were sacrificed just after the exposure, while others were kept for 6 or 10 months clearance time before sacrifice. There were no differences in body weight gain between fly ash exposure groups and controls. The burden of fly ash was estimated by the measurement of aluminum contents in rat organs. Aluminum concentrations in lungs of exposure groups were much higher than those of controls. No apparent deposition of fly ash was observed in the liver, kidneys, spleen, and blood, but lung burdens of up to about 0.7 mg of fly ash were found. The apparent deposition fraction was 5.1% after the 1-month exposure. The clearance rate of fly ash deposited in rat lungs may be very slow.

Administration, Inhalation↗
PubMed1986

Atrial pressure and secretion of atrial natriuretic factor into the human central circulation.

Atrial natriuretic factor, a peptide found in mammalian cardiac atria, has natriuretic and vasodilatory properties that may be important in the regulation of intravascular volume. To study factors related to its release in human subjects, intracardiac pressures and plasma atrial natriuretic factor concentrations in the central circulation were measured in 34 patients with a variety of cardiovascular disorders. Plasma atrial natriuretic factor concentration increased from the inferior vena cava to the right atrium (76 +/- 24 to 162 +/- 37 pg/ml, p less than 0.001) and from the vena cava to the aorta (76 +/- 24 to 177 +/- 46 pg/ml, p less than 0.001). Mean right atrial pressure was positively correlated with atrial natriuretic factor concentration in the pulmonary artery (r = 0.58, p less than 0.001), and mean pulmonary capillary wedge pressure was positively correlated with concentration in the aorta (r = 0.64, p less than 0.001). In six patients whose atrial natriuretic factor concentrations were measured at two different levels of atrial pressure, increased atrial pressure was accompanied by increased atrial natriuretic factor concentration in the pulmonary artery (p less than 0.01) and aorta (p less than 0.01). Atrial natriuretic factor levels measured in fresh myocardium from a patient undergoing cardiac transplantation showed tissue concentrations in the atria 500-fold higher than tissue concentrations in the ventricles. These data document that atrial natriuretic factor is found in human atrial myocardium and suggest that it may be released in response to increased atrial pressure. Such a secretory release mechanism is consistent with the hypothesis that atrial natriuretic factor plays a role in the regulation of circulatory volume.

Adult↗
PubMed1986

Crystal structure of a prokaryotic ribosomal protein.

The structure of ribosomal protein L30 from Bacillus stearothermophilus has been solved to a resolution of 2.5 A. The molecule is somewhat elongated and contains two helices and a three-stranded, anti-parallel beta-pleated sheet. The protein fold, in which helices pack on the same side of the sheet, generates a simple helix-sheet, two-layered motif. It is possible to distinguish three hydrophobic patches on the molecular surface, and one end has six isolated arginine and lysine residues. It is proposed that these reflect sites of protein-protein and protein-RNA interaction, respectively. The protein fold is very similar to that of the only other known ribosomal protein structure, L7/L12 from Escherichia coli, and, based on this similarity, an attempt is made to align the amino acid sequences of the two proteins.

Crystallography↗