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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 1,027 records · Page 57Linked to original sources
PubMed1988

Comparative study of the antitumor effect of two types of murine recombinant interferons, (beta) and (gamma), against B16-F10 melanoma.

A comparative study of the antitumor effect of murine recombinant interferon(beta) less than Mu-rIFN(beta) greater than and murine recombinant interferon(gamma) less than Mu-rIFN(gamma) greater on B16-F10 melanoma was conducted. Administration of Mu-rIFN(gamma) i.p. into C57BL/6 mice on days 1 to 7 produced a higher suppressive effect than Mu-rIFN(beta) both on the growth of s.c. implanted tumor and on the formation of artificial pulmonary metastasis. Pharmacokinetic study of Mu-rIFN(gamma) demonstrated that high plasma levels were retained for a long time. In clonogenic assay, Mu-rIFN(gamma) at 1000 units/ml showed about 80% inhibition of colonies of B16-F10 melanoma. However, Mu-rIFN(beta) hardly inhibited the colonies, even at 1000 units/ml. Augmentation of natural killer (NK) cytotoxicity was much greater with Mu-rIFN(beta) than Mu-rIFN(gamma), whereas Mu-rIFN(gamma) enhanced the cytotoxicity of peritoneal macrophages more strongly than Mu-rIFN(beta). Injection of Mu-rIFN(gamma) i.p. 1 day before tumor challenge also inhibited the formation of pulmonary metastasis of B16-F10 melanoma. However, pretreatment of mice with carrageenan significantly suppressed the inhibitory effect of Mu-rIFN(gamma). From these results, it is suggested that the inhibitory effect of Mu-rIFN(gamma) on the tumor growth and metastases of B16-F10 melanoma is mediated partly by direct antitumor effect and partly by the activation of macrophages, and that the augmentation of NK activity contributes mainly to the antitumor effect of Mu-rIFN(beta).

Animals↗
PubMed1988

Cytogenetic effect of carboplatin on human lymphocytes.

Carboplatin, a second generation cisplatin analogue, was tested for induction of sister chromatid exchange (SCE) as well as chromosomal aberrations in human lymphocytes in vitro and in vivo. A dose-dependent effect was observed for increased frequency of metaphases with SCE (r = 0.984, P less than 0.001) as well as chromosomal aberrations (r = 0.994, P less than 0.001), primarily chromatid gap or break, in vitro. SCE induction by carboplatin was less than that by cisplatin at the same concentration. When patients were treated with a single dose of carboplatin at a dose of 450 mg/m2, the frequency of SCE and chromatid type aberrations increased significantly. However, even when considering dose and peak plasma concentration in patients receiving carboplatin, it appears that the ability of carboplatin to induce SCE and chromosomal aberrations is weaker than that of cisplatin. SCE frequencies induced by carboplatin decreased with time going by, and in one patient who was tested 5 weeks after treatment, SCE frequency showed a decrease to the pretreatment level. It thus appears that carboplatin has an improved therapeutic index over the parent compound, cisplatin, because of its less mutagenic or carcinogenic hazard, in addition to the largely reduced incidence of untoward effects.

Aged↗
PubMed1988

New method for ultrasonic Doppler probe angle determination.

A new method is described to determine the Doppler probe angle using a standard pulsed Doppler; the technique is based on the determination of vessel position with respect to the skin surface. The transit times of ultrasound waves toward the vessel from multiple probe positions on the skin, the distance between probe positions, and the probe-skin angle are measured. Using the probe-skin angle and the slope of the regression curve, the vessel-skin angle is determined trigonometrically. Experimental results show high accuracy within a vessel-skin angle range of 5-40 degrees.

Mathematics↗
PubMed1988

Ampicillin concentrations in human serum and periodontal membrane following a single oral administration of talampicillin.

1. Ampicillin concentrations in human serum and periodontal membrane after a single oral administration of talampicillin (500 mg) were assayed by the agar diffusion (paper disc) method. 2. The peak times of serum and periodontal membrane were identical, being 150 min after administration. 3. The peak concentrations of serum and periodontal membrane were 7.81 micrograms/ml and 4.11 micrograms/g, respectively. 4. The mean ratio of periodontal membrane to serum concentration at the peak time was 0.53.

Administration, Oral↗
PubMed1988

Evaluation of corrective surgery for tetralogy of Fallot from late results by multivariate statistical analysis.

From 1966 to 1985, 469 pediatric patients with the tetralogy of Fallot (mean age, 4.9 years) were corrected (hospital mortality 11.9%). There were 9 late deaths (1.9%). In 186 patients, hemodynamic studies were performed 2-14 years postoperatively (mean age, 10.4 years). An increased cardiothoracic ratio (CTR) of 60% or more was found in 42 patients with impaired postoperative physical activity. The factors affecting the late results were investigated in relation to CTR by the quantification method of multivariate analysis. As for the enlarged CTR, pulmonary regurgitation was more of a contributing factor than pulmonary stenosis. In pulmonary regurgitation, the pulmonary artery area index (PAAI) and reconstruction of the right ventricular outflow tract (RVOT) were highly significant factors. For pressure gradient, the VSD site was the most significant factor. These analyses suggest that preservation and/or reconstruction of the pulmonary valve, or trans-annular patching with the necessary minimal area for the RVOT (PAAI) not to exceed 4 cm2/m2 at the time of operation is important for satisfactory late results.

Adolescent↗
PubMed1988

Massive systemic venous thrombosis after Fontan operation: report of a case.

A 7 year old boy with single ventricle with pulmonary stenosis underwent a modified Fontan procedure. He had a very stormy postoperative course complicated by continued pleural effusion, hepatomegaly, and chylothorax. He eventually died after an atrial septum reopening. At autopsy, massive thrombi were found in the inferior vena cava, right atrium, and pulmonary artery. This complication was probably due to multiple factors, but a routine anticoagulation therapy may be required after Fontan procedure.

Cardiac Surgical Procedures↗
PubMed1988

A bed temperature monitoring system for assessing body movement during sleep.

A method of monitoring and analysing temperature distribution in a patient's bed during bed rest and sleep is described. The system consists of 16 temperature sensors, a solid-state recorder and a personal computer. The temperature sensors are attached on the surface of a bed mat. The temperature of the 16 measurement points are recorded and stored on a multichannel solid-state recorder, where a programmable read-only memory (PROM) is used as the memory device. The PROM is detachable from the recorder, and the temperature data is read by a computer. A two-dimensional temperature distribution pattern is obtained by interpolating the temperature between measured points. The system was effective for long-term temperature monitoring without patient discomfort, and it proved reliable and easy to use. The temperature distribution and changes in the distribution indicated body movement and hence periods of sleep.

Beds↗
PubMed1988

Zinc concentration in plasma and erythrocytes of subjects receiving folic acid supplementation.

It has been suggested that oral supplements of folic acid interfere with the intestinal absorption of zinc and may have toxic side effects. The concentrations of Zn and folate in blood were monitored in a group of women with cervical dysplasia randomly assigned to receive 10 mg/d of either folic acid (pteroylglutamic acid) or ascorbate. Fifty subjects were evaluated after 2 mo; 21 of the same subjects were evaluated again after 4 mo. No untoward clinical effects were observed. Significant elevation of erythrocyte folate above the baseline value was observed in the supplemented group but not in the placebo group (p less than 0.001). The concentration of Zn in plasma and erythrocytes did not change significantly in either the folate-treated or placebo groups after 2 and 4 mo. It is concluded that carefully controlled clinical intervention trials of this type do not impose a risk of depleting the concentration of Zn in erythrocytes and plasma.

Clinical Trials as Topic↗
PubMed1988

Phase II study of carboplatin in small cell lung cancer.

Carboplatin (CBDCA; cis-diammine-1, 1-cyclobutane dicarboxylate platinum II), a new platinum analogue, was administered to 18 patients with small cell lung cancer (SCLC) at a dose of 300-450 mg/m2 intravenously every four weeks, in a phase II study. All patients could be evaluated to assess response and 17 for toxicity. The overall response rate was 28% (5/18), including one complete response. Of eight patients previously untreated, four (50%) showed a response, including one complete response. The response rate in patients with no previous cisplatin-treatment was 50% (5/10). Response durations in five responders were 2, 3, greater than 4, greater than 10 and 11 months. Toxicity was primarily hematologic, with thrombocytopenia being dose-limiting. Thrombocytopenia (less than 75,000/mm3) was observed in 12 patients (71%), six requiring platelet transfusion. Leukopenia (less than 3,000/mm3) was observed in 11 patients (65%). There were no episodes of serious infection or bleeding, however. Myelosuppression was more severe in heavily pretreated patients than in patients previously untreated. Dose reductions were required following multiple treatments for cumulative myelotoxicity. Mild to moderate nausea and vomiting occurred in seven patients (44%). Nephrotoxicity and ototoxicity were not observed. Carboplatin was demonstrated to be an active agent against SCLC. Further investigation into dose and schedule of CBDCA in combination chemotherapy is warranted.

Aged↗
PubMed1988

In vitro increase of histidine decarboxylase activity and release of histamine by peritoneal resident cells of mast cell-deficient W/Wv mice; possible involvement of macrophages.

When peritoneal resident cells (PRCs) of genetically mast cell-deficient WBB6F1-W/Wv mice were cultured in vitro for 5 h at 37 degrees C, their histidine decarboxylase [HDC, L-histidine carboxylase, E.C. 4.1.1.22] activity increased 10-fold. Since inhibitors for energy production and mRNA and protein syntheses inhibited this increase of HDC activity, it appeared to represent de novo synthesis of the enzyme, i.e., induction. This increase was followed by an increase in the amount of histamine in the culture medium of the cells, indicating that histamine synthesized by the induced HDC was not stored in the cells but was quickly released. Mast cells were not involved in the HDC induction, because the extents of HDC induction in PRCs of W/Wv and wild type +/+ mice were similar. The removal of T cells with anti-Thy-1,2 antibody and complement from the PRCs did not affect the HDC induction, but the removal of phagocytes decreased the induction to one-tenth in spite of a 2-fold increase in the proportion of B cells in the PRCs. After separation of the PRCs into adherent and non-adherent fractions, the increase in HDC activity was found to be associated with the adherent fraction that was mostly positive to esterase staining. These results suggest that HDC was induced in peritoneal macrophages.

Animals↗
PubMed1988

Radionuclide transport from soil to air, native vegetation, kangaroo rats and grazing cattle on the Nevada test site.

Between 1970 and 1986 the Nevada Applied Ecology Group (NAEG), U.S. Department of Energy, conducted environmental radionuclide studies at weapons-testing sites on or adjacent to the Nevada Test Site. In this paper, NAEG studies conducted at two nuclear (fission) sites (NS201, NS219) and two nonnuclear (nonfission) sites (Area 13 [Project 57] and Clean Slate 2) are reviewed, synthesized and compared regarding (1) soil particle-size distribution and physical-chemical characteristics of 239 + 240Pu-bearing radioactive particles, (2) 239 + 240Pu resuspension rates and (3) transuranic and fission-product radionuclide transfers from soil to native vegetation, kangaroo rats and grazing cattle. The data indicate that transuranic radionuclides were transferred more readily on the average from soil to air, the external surfaces of native vegetation and to tissues of kangaroo rats at Area 13 than at NS201 or NS219. The 239 + 240Pu resuspension factor for undisturbed soil at Area 13 was three to four orders-of-magnitude larger than at NS201 and NS219, the geometric mean (GM) vegetation-over-soil 239 + 240Pu concentration ratio was from ten to 100 times larger than at NS201, and the GM GI-over-soil, carcass-over-soil and pelt-over-soil 239 + 240Pu ratios for kangaroo rats were about ten times larger than at NS201. These results are consistent with the finding that Area 13, compared with NS201 or NS219, has a higher percentage of radioactivity associated with smaller soil particles and a larger percentage of resuspendable and respirable soil. However, the resuspension factor increased by a factor of 27 at NS201 when the surface soil was disturbed, and by a factor of 12 at NS219 following a wildfire. The average (GM) concentration of 239 + 240Pu for the GI (and contents) of Area 13 kangaroo rats and for the rumen contents of beef cattle that grazed Area 13 were very similar (400 vs. 440 Bq kg-1 dry wt, respectively) although the variability between individuals was very large. The GM carcass-over-GI 239 + 240Pu concentration ratio for kangaroo rats at Area 13, Clean Slate 2, and NS201 were similar in value (approximately 2 X 10(-2)), as were the GM GI-over-vegetation concentration ratios (approximately 2 X 10(0)) (no statistical differences).(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants, Radioactive↗
PubMed1988

Increased cholera toxin-, and forskolin-induced cyclic AMP accumulations in psoriatic involved versus uninvolved or normal human epidermis.

Psoriatic involved epidermis reveals variously altered receptor-adenylate cyclase responses; among them the most prominent is defective beta-adrenergic adenylate cyclase response, which is normally the major receptor-adenylate cyclase system of human epidermis. It is known that activation of hormone-stimulated adenylate cyclase, a membrane-bound enzyme complex, requires functional coupling of at least 3 distinct subunits: 1) receptor subunit (R), 2) guanine nucleotide binding protein (G), and 3) catalytic subunit (C). The precise nature of the beta-adrenergic defect in the psoriatic epidermis, however, remains to be determined, especially in terms of G and C function. Using the involved and uninvolved skin from psoriatic patients, we investigated effects of cholera toxin (which monitors G-C interaction) and forskolin (which monitors C function) on the adenylate cyclase system of epidermis, which were compared with those of normal human epidermis. Both agents increased cyclic AMP levels of involved, uninvolved, and normal human epidermis. Marked accumulations were observed in the presence of cyclic nucleotide phosphodiesterase inhibitor, isobutyl-methylxanthine (IBMX); without the phosphodiesterase inhibitor, the effect of each agent was minimal. Comparison of the effects of cholera toxin revealed that the psoriatic involved epidermis accumulates much more cyclic AMP than the uninvolved epidermis (involved: 193 +/- 65; uninvolved: 117 +/- 54 pmoles/mg protein/5 h). Similarly forskolin-induced cyclic AMP accumulations of the involved epidermis were much more than those of uninvolved epidermis (involved: 374 +/- 152; uninvolved: 101 +/- 41 pmoles/mg protein/2 h). Those of normal human epidermis were not significantly different from those of uninvolved epidermis (cholera toxin: 99 +/- 36 pmoles/mg protein/5 h; forskolin: 84 +/- 22 pmoles/mg protein/2 h). Our results indicate that G and C function and their interaction is not defective (but rather increased) in the psoriatic involved epidermis. This suggests that the defective beta-adrenergic response of psoriatic involved epidermis reflects defective R or R-G interaction of the epidermal adenylate cyclase system.

1-Methyl-3-isobutylxanthine↗
PubMed1988

Three schedules of recombinant human interleukin-2 in the treatment of malignancy: side effects and immunologic effects in relation to serum level.

Recombinant human interleukin-2 (rIL-2) was administered to 34 patients with advanced malignancy. Three schedules of rIL-2 administration employed were as follows: (A) 2-hr iv infusion of 6.7 X 10(5) U/m2/day (A1, 6 cases) or 2.2 X 10(6) U/m2/day (A2, 8 cases) for five consecutive days; (B) 24-hr continuous iv infusion of 3.3 X 10(5) U/m2/day (B1, 3 cases), 6.7 X 10(5) U/m2/day (B2, 7 cases) or 1.1 X 10(6) U/m2/day (B3, 5 cases) for 28 consecutive days; and (C) 24-hr continuous iv infusion of 6.7 X 10(5) U/m2/day (C, 5 cases) for 5 consecutive days per week for four weeks. The common side effects were fever (79%), eosinophilia (61%), malaise (56%), erythema or rash (50%), chills (38%) and nausea or vomiting (35%), with the dose-limiting toxicities being hypotension in group A, and renal dysfunction with fluid retention in groups B and C. In the case of 2-hr iv infusion, rIL-2 was rapidly cleared from the plasma, with a half life of about 30 min, while in the case of 24-hr continuous infusion, more than 1 U/ml serum IL-2 activity was maintained for 14 days in group B3. Natural killer (NK) and lymphokine-activated killer (LAK) activities were augmented by rIL-2 administration in patients of groups A, B3 and C. In eight patients of group B, NK and LAK activities transiently decreased after rIL-2 administration, and recovered by day 3. The percentage of IL-2 receptor and Leu HLA-DR positive cells reached the peak level on day 7 in group B. In patients of group C, the percentage of Leu HLA-DR positive cells as well as NK and LAK activities increased upon rIL-2 administration and decreased during an intermission of two days. However, the percentage of rIL-2 receptor positive cells increased during the intermission of rIL-2. The most effective schedule of rIL-2 administration was considered to be the schedule of group C on the basis of this study.

Adult↗
PubMed1988

Shear-layer detection in poststenotic flow by spectrum analysis of Doppler signals.

Spectrum analysis of the Doppler signals was performed 0.5 tube diameters downstream from an axisymmetric constriction with an area reduction of 80 percent in steady flow at a jet Reynolds number of 2840. Both pulsed and continuous wave (CW) Doppler spectra showed significant reverse flow components in the separated flow. The pulsed Doppler spectra exhibited sudden changes when the sample volume crossed the shear layer between the center jet and the separated flow. A power spectrum equation was theoretically derived from continuity of flow to define the Doppler shift frequency for the shear layer velocity. The CW Doppler spectrum showed a minimum spectrum density at a frequency which equalled the shear layer Doppler shift frequency derived from the equation. The pulsed spectra exhibited the sudden changes at the same frequency as well.

Blood Flow Velocity↗