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Biomedical subjects

K Tamura

Publications and source records attributed to K Tamura.

At least 1,153 records · Page 64Linked to original sources
PubMed1987

[Collision tumor of the stomach].

In a gastric neoplasm, malignant lymphoma is a relatively rare disease and a malignant lymphoma complicated by a carcinoma is very rarely found in the same stomach. As far as we could determine in a search of the literature, the coexistence of a gastric cancer and a malignant lymphoma was found in only 30 cases including our case and collision was seen in 10 of these. Our report concerns a recent case of malignant gastric lymphoma colliding with II c early gastric cancer, and is followed by a discussion. The patient, a man of 68, had complained of epigastralgia. The case was diagnosed as a gastric malignant lymphoma after an upper gastrointestinal roentgenogram and endoscopy. A biopsy revealed a torous malignant lymphoma (diffuse medium-sized cell type) and an II c early gastric cancer (tub 2) and suggested the collision between them.

Aged↗
PubMed1987

[Severity of aortic stenosis assessed by Doppler techniques].

Continuous wave (CW) Doppler ultrasound has facilitated accurate estimates of pressure gradient (PG) across a stenotic valve. However, the severity of stenosis cannot be assessed using PG alone because it is dependent on actual flow across the valve. In this study, Doppler techniques were used to predict PG and aortic valve areas (AVA) in adults with aortic stenosis (AS). Fifty-four adult patients undergoing cardiac catheterization for suspected AS were prospectively evaluated. There were 28 men and 26 women, who ranged in age from 25 to 68 years with a mean of 56 years. These Doppler ultrasound studies were performed using a 2 MHz transducer and an Aloka SSD-730. With CW Doppler ultrasound, the highest velocities of the aortic jet were recorded from an apical approach. Left ventricular outflow flows were recorded about 1.0-1.5 cm below the aortic annulus using high PRF. Doppler waveforms were analyzed for the AT/ET (AT: acceleration time, ET: ejection time), and Doppler PG was calculated from the maximum velocity (V) of the aortic jet based on a modified Bernoulli equation (PG = 4V2), and aortic valve area was obtained using the continuity equation-(AVA = left ventricular outflow tract stroke volume divided by AS jet velocity integral). These data were compared with hemodynamic data obtained from cardiac catheterization. The following results were obtained: 1. In eight patients with substantial aortic regurgitation, whose maximum catheter PG were from 20 to 45 mmHg, the AT/ET was less than 0.30. The ratio of AT/ET correlated with the peak velocity of the aortic jet (r = 0.88) and the maximum PG (r = 0.87) obtained from cardiac catheterization. 2. In 46 patients with AS, the maximum PG by CW Doppler showed an excellent correlation with maximum catheterization PG (r = 0.97, SEE 6 mmHg), and the mean PG as calculated by the two techniques also disclosed a good correlation (r = 0.97, SEE 5.4 mmHg).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1987

[Effects of phenytoin on cell-mediated immunity].

Phenytoin is a highly effective anticonvulsant agent that is widely administrated to prevent some kinds of patients with brain tumor. But it has been said that phenytoin may have some immunosuppresive potential for hosts. In this study, we evaluated the effects of phenytoin upon cellular immunity such as NK, CTL and LAK activity in murine models. Fresh splenocytes were taken out from mice (CBA/J, C 3 H/HeN, C 57 BL/6) into which phenytoin had been injected intraperitoneally at a daily dose of 1,000 micrograms for 28 days. The serum concentration of phenytoin in the experimental models was 10-20 micrograms/ml. The cytotoxic activities were estimated by a 4-hr 51Cr release assay. The mitogen-stimulated lymphocyte function was evaluated by 3H-thymidine incorporation into DNA. The NK activity was estimated by cytotoxicity of splenocytes of CBA/J mice against NK-sensitive YAC-1 cells. The cytotoxic T-lymphocyte (CTL) activity was estimated by cytotoxicity of splenocytes of C 57 BL/6 mice which were stimulated in vitro for 5 days by splenocytes of C 3H/HeN treated with mitomycin C, against RSV-M glioma cells. Lymphokine-activated killer (LAK) activity was estimated by cytotoxicity of LAK cells, which were induced from splenocytes of C 3 H/HeN mice by human recombinant interleukin-2 (rIL-2), against syngeneic RSV glioma and allogeneic 203 glioma cells. 3H-thymidine incorporation of splenocytes of C 57 BL/6 mice was reduced significantly (p less than 0.01) in phenytoin-treated mice. The cytotoxicity of splenocytes of non-treated CBA/J mice against YAC-1 cells was 75%, but that of phenytoin-treated CBL/J mice was a few %.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[Antitumor efficacy of recombinant interferon-beta on human glioma].

The antitumor efficacy of recombinant interferon-beta (rIFN-beta) on human glioblastomas was investigated in vitro and in meningeal gliomatosis(MG) models. A total of 1.5 X 10(5) human glioma (ONS-12 and ONS-20) cells were suspended in 2 ml of RPMI-1640 with 10% fetal calf serum and placed in plastic dishes (Falcon #3001). rIFN-beta 10(2)-10(5) units were then added to each culture dish on days 3, 5 and 7. Both ONS-12 and ONS-20 human glioma cells were suppressed with a low dose of rIFN-beta. As MG models, 5 X 10(7) ONS-12 glioma cells were suspended in saline and transcutaneously inoculated into the cisterna magna of BALB/c nu/nu mice using a 27-gauge needle. The median survival times (MST) of MG models which were treated by intrathecal administration of 10(3) U of rIFN-beta and intraperitoneal injection of 10(4) U of rIFN-beta were 11.0 and 8.0 days, compared with an MST of 7 days for control mice. The rIFN-beta was not effective by intraperitoneal administration but was effective by intrathecal administration in the MG models. The MSTs of MG models which were treated by administration of 10(5) U, 10(3) U of rIFN-beta and 0.1 ml saline were 15.0, 19.0 and 9.0 days, respectively. The therapeutic efficacy in MG models depended on the administration route of rIFN-beta, and as far as could be determined from the MG models, high-dose administration of rIFN-beta was not always useful.

Animals↗
PubMed1986

Calcitonin gene-related peptide excites myenteric neurons.

Intracellular methods were used to record electrical behavior of myenteric neurons in guinea-pig ileum in vitro. Calcitonin gene-related peptide (CGRP; 1 nM to 1 microM) and calcitonin (1-100 microM) were applied by addition to the superfusion solution of longitudinal muscle-myenteric plexus preparations. Both peptides were applied also by pressure ejection from fine-tipped micropipettes. CGRP, applied by either method, evoked a long-lasting depolarization of the cell membranes that was dose-dependent (ED50 = 50 nM) and was associated with an increase in the input resistance, suppression of post-spike hyperpolarizing potentials and enhanced excitability in all neurons that were tested. The enhanced excitability was reflected by a significant increase in the number of action potentials evoked by intracellular injection of constant current depolarizing pulses. Enhanced excitability also was apparent as a train of spikes that appeared at the crests of the CGRP-induced depolarization. The excitatory action of CGRP simulated slow synaptic excitation. Application of calcitonin did not evoke any changes in electrical behavior of myenteric neurons. The results are consistent with a neurotransmitter or neuromodulator role for CGRP in the enteric nervous system and suggest that it may participate in local neurohumoral regulation of gastrointestinal effector systems.

Action Potentials↗
PubMed1986

Effects of pressure and potassium chloride on the aggregation of poly(gamma-benzyl-L-glutamate) in liposomal bilayers.

Fluorescence depolarization studies were made on dimyristoylphosphatidylcholine liposomes containing four kinds of dansylated poly(gamma-benzyl-L-glutamate) with different degrees of polymerization or hydrocarbon chain lengths under high pressure at up to 981 bar (1 bar = 10 MPa). Potassium chloride promoted the aggregation of the synthetic peptides in liposomal bilayers at both atmospheric and high pressure. The chain lengths of the hydrocarbons of the peptides had more influence than their degrees of polymerization on aggregation.

Dimyristoylphosphatidylcholine↗
PubMed1986

Cortical cells driven by the low-threshold tooth pulpal afferent in cats.

The input pattern and spatial distribution of tooth pulp-driven neurons (TPNs) in the cat cortex were studied by recording the unitary activities of these neurons. Stimulation was applied to the upper and lower canine and molar tooth pulps. It was possible to record activities of TPNs in the deep layers of the areas 3a and 3b of the coronal gyrus of cerebral cortex. TPNs driven by the ipsilateral tooth pulp stimulation were distributed more anteroventrally than those driven by contralateral stimulation. Cells driven by bilateral pulp stimulation were situated between these two neurons. The threshold intensity for TPNs in the area 3a was lower than that for neurons in 3b. The majority of TPNs in the area 3a of the anterior part of the coronal gyrus received inputs from low-threshold masseteric muscular afferents as well as from tooth pulp afferents. The findings suggest that TPNs in the area 3a may have a relation to orofacial motor functions.

Animals↗
PubMed1986

Clinical analysis of 33 patients with adult T-cell leukemia (ATL)-diagnostic criteria and significance of high- and low-risk ATL.

The clinical characteristics of 33 patients with adult T-cell leukemia (ATL) are described. All patients were born and have lived in Miyazaki Prefecture (southwest of Japan). Because of a wide range of clinical presentations and courses, they were subdivided into 2 groups. In the high-risk group, patients presented with high white-cell counts (WBC greater than or equal to 20,000/microliter) and over 30% of abnormal lymphoid cells (18 patients) and hypercalcemia with a low percentage of leukemic cells (5 patients). In this group the median survival time was only 3 months despite various modes of treatment. In contrast, patients of the second group exhibited a low percentage of abnormal lymphoid cells (WBC less than 20,000/microliter and/or leukemic cells less than 30%) and had no hypercalcemia (8 patients). Their clinical course was chronic with a median survival of 8 months, regardless of modalities of treatment. Two patients went through a period when the number of circulating leukemic cells was low (less than or equal to 5%) before overt leukemia appeared. Other clinical features, signs, symptoms, routine laboratory data, serum anti-ATL-associated antibody, cell membrane markers and cytogenetic studies were similar to those observed in other districts of Kyushu island.

Adult↗