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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 1,081 records · Page 60Linked to original sources
PubMed1987

Automated measurement of the electro-oculogram for clinical use.

A method of automated measurement of the EOG amplitude is described. Its main advantages are as follows: 1. The mean of amplitudes, at a series of time dots within a single EOG deflection recorded with DC-amplification, are automatically measured and printed out. 2. Artifacts due to blinks, overshoots or other irregular eye movements are automatically eliminated. 3. A base line drift is automatically compensated. The L/D ratios obtained in 80 eyes with this method were essentially equal to those obtained by a manual measurement (correlation coefficient 0.9905).

Adaptation, Physiological↗
PubMed1987

Prognostic factors in non-small cell lung cancer: multiregression analysis in the National Cancer Center Hospital (Japan).

A total of 190 patients with unresectable non-small cell lung cancer (NSCLC) were analyzed retrospectively using eight pretreatment and three treatment-related prognostic factors in terms of influence on survival. All the patients received chemotherapy with or without chest irradiation, according to the protocol of phase II or phase III trials of the National Cancer Center Hospital Tokyo between April 1980 and December 1985. The eight pretreatment factors selected were performance status, sex, stage, age, histology, and metastasis to brain, bone or, liver. Three treatment-related factors were radiation therapy to the primary site, response to chemotherapy, and treatment period, before or after clinical administration of cis-diamminedichloroplatinum (II) (CDDP). Of the 190 patients, 71 (37.4%) were alive for more than 1 year, but only 17 patients (8.9%) survived 2 years after the initiation of chemotherapy. By univariate analysis, performance status 0-1, female, no metastasis to bone or liver, response to chemotherapy, and treatment period after CDDP were considered to be favorable prognostic factors. By multiregression analysis, performance status, sex, and treatment period after CDDP proved to be important factors for long-term survival. Consideration of these prognostic factors could enable the results of chemotherapy to be more accurately evaluated, and stratification of patients with advanced NSCLC based on performance status and sex before entry into a randomized controlled trial is recommended.

Adenocarcinoma↗
PubMed1987

The effects of prazosin and propranolol in combination with thiazide diuretics on blood pressure and serum lipids: a multicentre study.

We have carried out randomized 12-week multicentre study to compare the effects of prazosin and propranolol on blood pressure and serum lipids in 70 patients with essential hypertension after a 4 week minimum period of treatment with thiazide diuretics. After 12 weeks treatment with prazosin (n = 40, 1.5-12.0 mg per day) or propranolol (n = 30, 30-120 mg per day) with diuretics there was a significant blood pressure reduction from 165.1/97.9 mmHg to 151.2/90.6 mmHg and from 167/96.5 mmHg to 153/91.9 mmHg, respectively. In the 12th week a significant decrease was noted in triglyceride and in low-density lipoprotein cholesterol (LDL + VLDL-C), but no significant effects were seen in high-density lipoprotein cholesterol (HDL-C) in patients receiving prazosin. On the other hand, a significant decrease in lecithin cholesterol acyltransferase (LCAT) was seen in patients receiving propranolol. Twenty-six of 40 patients receiving prazosin were given an additional 12 weeks of treatment. Twenty-two of 30 patients initially treated with propranolol were switched from propranolol to prazosin after 13 weeks and given prazosin up to the 24th week. At 24 weeks, the blood pressure was 149/93.0 mmHg in the prazosin group and 155/89.2 mmHg in the group which switched from propranolol to prazosin. Triglyceride remained reduced in the prazosin group at the 24th week. In the group which switched from propranolol to prazosin, triglyceride decreased significantly over the next 12 weeks.

Benzothiadiazines↗
PubMed1987

In vitro methods for studying the accuracy of velocity determination and spatial resolution of a color Doppler flow mapping system.

We tested a color Doppler flow mapping system (Aloka 880, 3.5 mHz) to image the steady flow of a suspension of cornstarch (0.1% to 1.75%) in water, flowing at known velocities through a series of Tygon tubing with internal diameters of 1.6 to 4.8 mm and latex rubber tubing (7.9 to 15.9 mm) in a water tank. Flow through the tubes was imaged at 2 to 12 cm and 2 to 18 cm distances from the transducer, by the use of the near and far focus settings of the instrument. First, the color flow diameters were compared to the known internal diameters of the tubing oriented at a 30- to 70-degree flow angle to the direction of interrogation to test axial resolution as well as lateral resolution. For the near transmit focus setting, the color diameters increasingly overestimated the actual flow diameters as the distance from the transducer increased progressively beyond 6 cm (i.e., overestimation of up to 25 mm or 500% for the 4.8 mm tubing and 250% for the 9.5 mm tubing at 16 cm from the transducer). For the far transmit focus setting and for distances within 10 cm, the color diameters did not differ significantly (i.e., more than 1 mm) from the actual diameter. The lowest velocity color encoded by the instrument was 3 cm/sec for a pulse repetition frequency of 4 kHz. At a flow velocity of about 50 cm/sec, 6 cm distance from the transducer and mid gain settings, flow through the 1.6 mm tube barely color coded, while flow through 2.4, 3.2, and 4.8 mm tubes was easily imaged.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1987

Increased methionine synthetase activity in zinc-deficient rat liver.

To study the effect of zinc deficiency on folate metabolism, three groups of male Sprague-Dawley rats (zinc deficient (ZD), restricted-fed (RF + Zn), and ad libitum-fed control (control] were given a semipurified 25% egg white protein diet. The ZD group received less than 10.3 nmol zinc/g of diet, while the RF + Zn and control groups were given 1620 nmol zinc/g of diet. After 6-7 weeks of feeding, severe zinc deficiency developed in ZD rats. Hepatic methionine synthetase activity was increased in the ZD group compared to both the RF + Zn and control groups, but hepatic 5,10-CH2-H4folate reductase activity was similar in all groups. This increased methionine synthetase activity found in zinc-deficient rats might induce secondary alterations in folate metabolism. These changes include significantly lowered plasma folate levels, decreased 5-CH3-H4folate in liver, and increased rates of histidine and formate oxidation. The latter two findings suggest that the available non-5-CH3-H4folate is increased in zinc deficiency.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1987

Clonotypic comparison of IgG anti-DNA antibodies of healthy subjects and systemic lupus erythematosus patients: studies on heterogeneity and avidity.

Qualitative characteristics of IgG anti-ssDNA antibodies were studied and compared by isoelectric focusing (IEF) and enzyme-linked immunosorbent assay (ELISA) between normal human sera (NHS) and systemic lupus erythematosus (SLE) sera. In NHS, IgG anti-ssDNA spectrotypes were observed in a high alkaline pH range (7.5 to 8.5) at physiological NaCl concentrations (0.15 M). In SLE sera the spectrotypes were found to a more intensified extent in the alkaline pH range as compared to those in NHS. With regard to avidity, analyzed by salt-dependent changes of anti-ssDNA activities, NHS showed strong ssDNA-binding bands in a wide range of pH 7.0-8.5 comparable to those in SLE sera. However, these bands became extremely weak and/or faint in pH 7.5-8.5 as the NaCl concentration was raised to 0.15 M and 0.20 M. On the other hand, SLE sera still exhibited thick binding bands at higher NaCl concentrations. This salt-dependency of these antibodies was-also demonstrated by ELISA of serum samples adjusted to contain comparable antibody levels. These findings suggest that clonotypes of IgG anti-ssDNA antibodies both in NHS and in SLE sera are essentially oligoclonal and highly cationic, and that the distinctive characteristics of these antibodies in NHS may be of low avidity, in contrast to SLE sera which exhibit high avidity.

Adult↗
PubMed1987

Induction of histidine decarboxylase in non-mast cells in the spleen of mice by injection of staphylococcal enterotoxin A.

Injection of Staphylococcal enterotoxin A (SEA) into WBB6F1-W/WV mice genetically deficient in mast cells resulted in a 10-fold increase in the histidine decarboxylase [HDC, L-histidine carboxylase, EC 4.1.1.22] activity of their spleen. The nature of the spleen cells responsible for this increased HDC activity was studied. The HDC induction by SEA was abolished on day 1 after X-ray irradiation of the mice at 400 rad and restored by transplantation of bone marrow cells from normal WBB6F1-+/+ littermates into the X-ray irradiated WBB6F1-W/WV mice. Transplantation of cells from other organs of the normal mice, such as the thymus, mesenteric lymph node and spleen, did not restore the HDC increase significantly. Transplantation of cultured mast cells also did not restore the increase. Moreover, the high HDC activity of spleen cells induced by SEA was not affected by their treatment with anti-Thy-1,2 antibody and complement. Depletion of phagocytes from the spleen by treatment with carbonyl iron resulted in decrease in HDC activity. These results suggested that phagocytic cells derived from haemopoietic stem cells of the bone marrow were responsible for the increase in HDC activity induced by SEA.

Animals↗
PubMed1987

Induction of murine gamma interferon production by lipopolysaccharide and interleukin-2 in Propionibacterium acnes-induced peritoneal exudate cells.

Lipopolysaccharide (LPS) induces high levels of gamma interferon (IFN-gamma) in the circulation of mice pretreated with heat-killed Propionibacterium acnes. The following results were obtained in the present study. LPS, as well as interleukin-2 (IL-2), was also able to induce IFN-gamma in vitro in peritoneal exudate cells (PEC) from such mice. Splenocytes and lymph node cells from these mice or resident peritoneal cells from control mice produced trace or undetectable amount of IFN-gamma upon exposure to LPS. A synergistic effect on IFN-gamma induction was observed when LPS was added to a culture of PEC together with IL-2. Indomethacin augmented the induction of IFN-gamma by LPS or IL-2, and prostaglandin E2 reversed its effect. Deprivation of plastic-adherent or nylon wool-adherent cells abolished the induction by LPS or IL-2, whereas it did not affect that by concanavalin A. Culture supernatant of plastic-adherent cells incubated with LPS stimulated the nylon wool-nonadherent cells to produce IFN-gamma in the presence of IL-2, but interleukin-1 or phorbol myristic acetate did not replace the LPS-stimulated supernatant. The ability of PEC to produce IFN-gamma measured as a function of time after P. acnes injection increased in proportion to their natural killer (NK)-like activity against YAC-1 cells. Moreover, treatment of PEC with monoclonal anti-Thy-1 antibody or with anti-asialo GM1 antiserum plus complement eliminated the production of IFN-gamma and the NK-like activity simultaneously, whereas treatment with monoclonal anti-Lyt-2 antibody plus complement did not. These results suggest that IL-2 and some unidentified factor released from plastic-adherent cells by LPS stimulation cooperatively induce IFN-gamma production in activated, Thy-1- and asialo GM1-positive NK-like cells appearing in inflammatory reactions and that prostaglandin E2 regulates IFN-gamma production in these cells.

Animals↗
PubMed1987

Continuous-wave Doppler velocities and gradients across fixed tunnel obstructions: studies in vitro and in vivo.

The simplified Bernoulli relationship appears to be quite accurate for predicting gradients across discrete valvular obstructions. Controversy exists about how accurately it predicts the severity of disease in longer segment obstructions. In this study we constructed a pulsatile model of subvalvular pulmonary stensosis in vitro to study nine custom-made subvalvular tunnels 2, 4, and 7 mm in length with flow cross sections of 0.5 to 1.5 cm2 and with the stenotic segment proximal to a nonstenotic bioprosthetic valve, and a pulsatile model in vitro of a 16 mm long tunnel-like ventricular septal defect (VSD) of varying cross-sectional area (0.20 to 0.64 cm2). We also compared the observations in vitro with those in an open-chest dog preparation with a tunnel-like interventricular communication. In the subpulmonic stenosis model, for each individual tunnel, 10 instantaneous peak gradients between 15 to 105 mm Hg were available. The pressure gradients across the tunnel alone, measured in the subvalvular area, were consistently higher than the measured gradients across the tunnel plus valve, suggesting some relaminarization of flow (i.e., a decrease in velocity) and pressure recovery (i.e., an increase in pressure) distal to the obstruction. Continuous-wave Doppler velocities across the 4 and 7 mm tunnels for the highest gradients were slightly lower than for the 2 mm tunnel at the same gradients, and it was only for the 0.5 cm2 cross section, 4 and 7 mm tunnels that there was a suggestion of minor viscous energy loss. For all the subvalvular tunnels studied, the Bernoulli relationship accurately predicted the results of the pressure drop across the tunnel only, while the gradient across tunnel plus valve was consistently lower. For the VSD tunnel model in vitro, the Doppler-derived gradients were approximately 40% higher than the measured gradients. The findings for the subvalvular and VSD tunnels in vitro and similar findings in the open-chest dogs with VSD suggest that relaminarization of flow and recovery of pressure occurred distal to the tunnel orifice, whereas continuous-wave Doppler findings correlate with the highest instantaneous gradients measured in the lowest pressure areas at the vena contracta of the tunnel.

Animals↗
PubMed1987

[Antitumor effects of royal jelly (RJ)].

Antitumor effects of Royal Jelly (RJ) were investigated employing the transplantable tumors of mouse advance leukemia L1210 and P388 strains and Ehrlich, Sarcoma-180 ascites and solid tumor strains. RJ was administered orally in a prophylactic-therapeutic (30 days before and 30 days after the transplantations of tumor cells) or a therapeutic (30 days after the transplantations of tumor cells) manner. Tumor cells were transplanted i.p. (ascites tumor) or s.c. (solid tumor). The daily dose of RJ was 0 (control), 10, 100, or 1000 mg/kg. In the case of the therapeutic experiments employing advance leukemia L1210 and P388 strains, which gave quite a short survival period of 8 approximately 9 days, RJ did not show any antitumor effect. In the case of the therapeutic RJ application employing the Sarcoma-180 ascites tumor, which gave a moderate survival period of 16 days, the increased life span was 9.3 approximately 19.3%; and with the Ehrlich ascites tumor (survival period of 22.1 days), the increased life span was 20.4% (RJ 10 mg/kg . day) and 17.6% (RJ 1,000 mg/kg . day), but no antitumor effect was observed at the dose of 100 mg/kg . day. In the case of the therapeutic experiment employing Ehrlich solid tumor, tumor growth inhibition was 25.3 approximately 54.8%, where as the use of the prophylactic-therapeutic regimen gave a tumor growth inhibition of 38.3 approximately 45.7%. In the case of the therapeutic RJ application employing Sarcoma-180 solid tumor, tumor growth inhibition was 45.1 approximately 59.7%, where as the prophylactic-therapeutic regimen gave a tumor growth inhibition of 49.1 approximately 56.1%.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗