Search PubMed⌕ Search

Biomedical subjects

T Takubo

Publications and source records attributed to T Takubo.

At least 109 records · Page 6Linked to original sources
PubMed1991

Epithelium modulates the potency of vasoactive intestinal peptide in the guinea pig.

The purpose of the study was to evaluate the importance of the epithelium in determining the potency of exogenous vasoactive intestinal peptide (VIP) in inhibiting responses of isolated guinea pig trachea to vagal stimulation. Isolated innervated tracheal preparations (n = 56) were mounted in glass organ baths in Krebs-Henseleit (K-H) solution at 37 degrees C and gassed with 95% O2-5% CO2. The inside of the trachea was separately perfused with K-H solution at 1 ml/min. The vagal nerve trunks were stimulated (20 V, 1-ms pulses, 10-s trains) at low (0.5 Hz) and high frequency (15 Hz) alternately, and the contractile responses were measured as increases in intratracheal pressures. VIP (10(-8)-10(-7) M) inhibited responses to both high- and low-frequency stimulation. VIP was more potent in inhibiting contractions when administered to the outside than the inside surface of the trachea, and disruptionon of the epithelium abolished this difference. The endopeptidase inhibitors phosphoramidon and thiorphan (5 x 10(-6) M) potentiated the action of VIP. These data indicate that the epithelium reduces the efficacy of VIP. We suggest that the epithelium is a site of degradation of VIP by endopeptidase and may also be a diffusion barrier.

Animals↗
PubMed1991

Ventilatory effects of percutaneous magnetophrenic stimulation.

This study was conducted with the purpose of elucidating the ventilatory effect of percutaneous magnetic stimulation of the phrenic nerve and investigating the possibility of clinically utilizing this effect as the mechanism of an artificial respirator. A magnetic stimulator consisting of a flat circular coil generating strong magnetic fields up to a maximum of 1.3 Tesla was developed. Formed from 1.8 mm diameter copper wire, this coil is 40 mm in diameter, 14 mm in thickness and has an inductance of 24 microH. The appurtenant current generator can deliver more than 5000 A to the coil. The capacitor terminal voltage (Vc) of the generator was used as a parameter of the intensity of the stimulus. Ventilatory effects were assessed mainly by diaphragmatic electromyogram and by transdiaphragmatic pressure, ventilation flow and tidal volume measurements. Magnetic stimulation was applied percutaneously to a unilateral phrenic nerve in dogs as well as human subjects and also to a median nerve of the forearm in human subjects. The range of stimulatory intensity Vc necessary to obtain ventilatory effects was 400-500 V, and the tidal volume thus obtained corresponded to normal breathing at rest for both dogs and humans. No pain was felt in the vicinity of point of application of the stimulator and there were no significant adverse effects such as changes in the ECG or heart rate. These results indicated that percutaneous magnetic stimulation of the phrenic nerve could produce adequate ventilatory effects in control applications.

Animals↗
PubMed1990

Development and clinical application of a portable oxygen concentrator.

We have produced a compact, lightweight oxygen concentrator, using a newly-developed polymer of poly [1-(trimethylsilyl)-1-propyne] with a performance, i.e. oxygen permeability, of 61 x 10 cm3 (STP) cm/cm2 s cmHg, which is 17 times higher than that of the membrane material of conventional concentrators. The oxygen and nitrogen selectivity was 1.80. The dimensions of the apparatus are 325 x 180 x 150 mm and it weighs about 4.0 kg. It is actuated by a battery (DC 12 V, 5.6 Ah), with a 100 V AC source and a car battery (12 V) source also available. The power consumption is 70 W. The generated oxygen concentration is about 30%, and the maximum flow rate is 41/min. Applying 10 samples of various chronic pulmonary diseases to the subject, the suction of oxygen from the apparatus in the patients' rest state was conducted. An increase in the PaO2, from an average of 59.1 Torr before the suction to an average of 68.5 Torr after the suction, together with easing of breathing, was indicated. The usefulness of this apparatus for supplying portable oxygen-treatment to patients with chronic respiratory disease is shown.

Berylliosis↗
PubMed1988

Serum doxapram and respiratory neuromuscular drive in normal man.

To investigate the means by which doxapram affects the control of ventilation, ventilatory function and P0.1 have been related to serum doxapram concentration during a 45-min infusion of doxapram hydrochloride in 7 healthy, conscious subjects under normoxic conditions. Serum doxapram concentrations increased during the infusion: 1.88, 2.48, 3.42, and 3.97 micrograms/ml after 5, 10, 30 and 45 min, respectively. The majority of significant changes in the measurements from the baseline were observed at 30 and 45 min: VE, VT, P0.1, P0.1/end-tidal CO2 tension, VT/Ti and blood pressure were increased, and end-tidal CO2 tension was decreased. No significant changes in Pdimax, Ti/Ttot, VE/P0.1, and P0.1/(VT/Ti) were observed. A correlation was observed between the % increases in P0.1 and VE and doxapram concentration, and between VE and P0.1. The doxapram-induced increase in VE appears to be caused by increased neural drive. It is related to the serum drug concentration in the conscious subject.

Adult↗
PubMed1987

A case of lowered eosinophilic leucocyte peroxidase activity found unexpectedly using an automated haematology analyser (the Technicon H6000 system)

The Technicon H6000 system simultaneously determines blood cell and leucocyte differential counts automatically using cytochemistry and cell size measurements. Part of the information provided by this instrument is a plot of peroxidase staining intensity against leucocyte cell size called 'the leucocyte peroxidase distribution display'. Recently, an abnormal leucocyte peroxidase distribution display was observed, on a sample from a post-operative lung cancer patient, in which eosinophilic leucocytes did not react with peroxidase. Neutrophils reacted in a normal way with this sample. The eosinophils were further examined by electron microscopy and manual peroxidase staining. Some peroxidase positive granules were observed in the eosinophilic leucocytes. The abnormal leucocyte peroxidase distribution display was found to be due to a separate group of eosinophilic leucocytes with lowered peroxidase activity.

Blood Cell Count↗
PubMed1986

Differential count of 5,000 leukocytes for acute nonlymphocytic leukemia patients during remission.

In order to find the level of leukemic cells during remission a differential count of 5,000 leukocytes was made in 91 acute nonlymphocytic leukemia cases during their first complete remission. Patients were divided into three groups according to the level of leukemic cells, i.e., 0-1/5,000, 2-4/5,000 and 5-/5,000. A close correlation was observed between the survival of patients and the level of leukemic cells and their tendency to decrease or increase during remission. All patients in whom leukemic cells rose from 0-1/5,000 to a level higher than 8/5,000 suffered a documented relapse after 4-8 weeks. This method appears to be a good supportive examination for acute leukemia patients during remission.

Acute Disease↗
PubMed1984

Detection of human T-cell leukemia virus antibodies in a Japanese T-cell leukemia patient with hypercalcemia.

A T-cell (KH-2) from a Japanese T-cell leukemia patient with hypercalcemia has been characterized and shown to be similar in its properties to Human T-cell leukemia virus (HTLV)-positive T-cell lines from T-cell leukemia patients from different parts of the world. The HTLV isolated from the Japanese T-cell leukemia patient with hypercalcemia belongs to the HTLV family and has properties similar to HTLV from T-cell leukemia patients from the United States, Israel, and the Caribbean.

Antibodies, Viral↗
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

[Early phase II study of PL-AC [N4-palmitoyl-(1-beta-D-arabinofuranosyl) cytosine] on hematopoietic malignancies].

Twenty-one patients with hematopoietic malignancies including 6 previously untreated, 9 pretreated, and in relapse, 5 in complete remission and one in partial remission all were treated with PL-AC. The patients consisted of 12 acute myelocytic leukemias, 4 acute monocytic leukemias, 2 acute lymphocytic leukemias, one erythroleukemia, one malignant lymphoma and one chronic monocytic leukemia. PL-AC was given orally at a dosage of 50-1200 mg daily. Mean total dosage was 4.74 g (0.6-15.25), and the mean administration period was 3.43 days (1-122). days Responses were observed in 4 out of 9 pretreated patients by a decrease of blast cells in the peripheral blood. Partial remission was obtained in one case which lasted 8 months. Out of 5 previously untreated acute leukemias, one partial remission and 4 hematological responses were observed. The plasma concentration of Ara-C was maximal at 3 hours and was not detectable after 12 hours. Side effects observed were nausea in 5 patients vomiting in one patient and liver dysfunction in one patient. These side effects however were not so severe as to stop drug administration. PL-AC may be administered in doses ranged 150-250 mg for 2-3 weeks without any severe side effects, and with some clinical effects.

Administration, Oral↗
PubMed1983

Classification of acute non-lymphocytic leukemia according to the distribution picture of peroxidase activity and cell size: correlation between the classification and therapeutic response.

A distribution picture was prepared on the basis of the correlation between peroxidase activity and cell size in leukemic cells using an automated leukocyte differential counter (Hemalog-D). From this, acute nonlymphocytic leukemia was classified into three groups in which the therapeutic response was examined. The leukemic cells of Group I were medium or large and were negative or weakly positive to peroxidase. These cells were characterized by their location in the upper part of the normal lymphocyte distribution. The leukocyte differential count, measured by a computer on the basis of the distribution picture, showed an increase in large unstained cells (LUC) and lymphocytes. The leukemic cells of Group II were large and positive to peroxidase and were characterized by their location in the right upper part, across the region of LUC, monocytes, basophil and neutrophil leukocytes as seen in the distribution picture. The findings of Hemalog-D showed an increase in LUC, remainder and neutrophil leukocytes. The leukemic cells of Group III were medium-sized and moderately or strongly positive to peroxidase. This group was characterized by their location in the lower part of normal neutrophil leukocytes and Hemalog-D showed an increase in neutrophil leukocytes. A total of 71 patients with acute nonlymphocytic leukemia were assessed according to this classification. Group I (14 patients): 11 with acute myelogenous leukemia (AML), 2 with acute monocytic leukemia (AMoL) and 1 with acute myelomonocytic leukemia ( AMMoL ); Group II (17 patients): 7 with AML and 10 with AMoL; Group III (40 patients): 28 with AML, 4 with AMoL, 1 with AMMoL and 7 with acute promyelocytic leukemia (APL). These groups were treated with the protocol (DCMP two step, BH-AC DMP, BH-AC AMP) established by the Yamada Leukemia Study Group of the Japan Welfare Ministry Cancer Research Project (chairman Yamada, K). The complete remission rate was 35.7% in Group I, 58.8% in Group II and 85.0% in Group III. The difference between Groups I and III was statistically significant (P less than 0.005), as was the difference between Groups II and III (P less than 0.1), while that between Groups I and II was not significant. The median survival was 12 months in Group I, 9 months in Group II and 15 months in the Group III and the difference between Groups I and III was statistically significant (P less than 0.05). Group III included a small number of AMoL and APL patients in addition to AML, while Groups I and II consisted mainly of patients with AMoL and AML.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗