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Biomedical subjects

I Suzuki

Publications and source records attributed to I Suzuki.

At least 217 records · Page 12Linked to original sources
PubMed1990

Light Induction and the Effect of Nitrogen Status upon the Activity of Carbonic Anhydrase in Maize Leaves.

The regulation of carbonic anhydrase (CA) activity in maize (Zea mays L.) leaves by light and nitrogen nutrition was determined. CA activity increased by more than 100-fold in illuminated leaves and decreased in leaves placed in the dark; low levels of CA activity were observed in leaves illuminated with low light intensities. CA activity was reduced in plants grown under nitrogen deficiency and recovered only slowly when supplemented with nitrate. Parallel studies were conducted to follow the levels of phosphoenolpyruvate carboxylase. Experiments indicate that the level of CA and phosphoenolpyruvate carboxylase present in leaves may be controlled by similar mechanisms.

Journal Article↗
PubMed1990

[Experiments of contamination with bacteria while transfusion between the newly developed porous polymer plug and by air needle plug].

We newly developed a transfusion plug that has an air passage of polymer porous material (I Cap). This porous polymer material theoretical does not pass the infectious microorganisms. We experimented contaminations during the transfusions by I Cap and that using air needles. Trypticated soy broth was used for the experiments. Experiments of transfusion in a dusty environment revealed that the transfusions by air needles got 100% contamination and that by I Cap was 0%. The experiments in a clinic room transfusions also revealed that air needle resulted in 30.3% contamination but on the contrary 0% with the I Cap. Dusty air was flown under high pressure (1.5 atmospheric pressure) through the same filter of I Cap for 30 minutes into the trypticated soy broth. These experiments revealed that the filter did not permeate bacteria and that transfusions with air needle was contaminated with dust.

Air↗
PubMed1990

Ferrous Iron and Sulfur Oxidation and Ferric Iron Reduction Activities of Thiobacillus ferrooxidans Are Affected by Growth on Ferrous Iron, Sulfur, or a Sulfide Ore.

Eight strains of Thiobacillus ferrooxidans (laboratory strains Tf-1 [= ATCC 13661] and Tf-2 [= ATCC 19859] and mine isolates SM-1, SM-2, SM-3, SM-4, SM-5, and SM-8) and three strains of Thiobacillus thiooxidans (laboratory strain Tt [= ATCC 8085] and mine isolates SM-6 and SM-7) were grown on ferrous iron (Fe), elemental sulfur (S), or sulfide ore (Fe, Cu, and Zn). The cells were studied for their aerobic Fe - and S-oxidizing activities (O(2) consumption) and anaerobic S-oxidizing activity with ferric iron (Fe) (Fe formation). Fe-grown T. ferrooxidans cells oxidized S aerobically at a rate of 2 to 4% of the Fe oxidation rate. The rate of anaerobic S oxidation with Fe was equal to the aerobic oxidation rate in SM-1, SM-3, SM-4, and SM-5, but was only one-half or less that in Tf-1, Tf-2, SM-2, and SM-8. Transition from growth on Fe to that on S produced cells with relatively undiminished Fe oxidation activities and increased S oxidation (both aerobic and anaerobic) activities in Tf-2, SM-4, and SM-5, whereas it produced cells with dramatically reduced Fe oxidation and anaerobic S oxidation activities in Tf-1, SM-1, SM-2, SM-3, and SM-8. Growth on ore 1 of metal-leaching Fe-grown strains and on ore 2 of all Fe-grown strains resulted in very high yields of cells with high Fe and S oxidation (both aerobic and anaerobic) activities with similar ratios of various activities. Sulfur-grown Tf-2, SM-1, SM-4, SM-6, SM-7, and SM-8 cultures leached metals from ore 3, and Tf-2 and SM-4 cells recovered showed activity ratios similar to those of other ore-grown cells. It is concluded that all the T. ferrooxidans strains studied have the ability to produce cells with Fe and S oxidation and Fe reduction activities, but their levels are influenced by growth substrates and strain differences.

Journal Article↗
PubMed1990

Determination of precise focus distribution and tailored lobectomy in temporal lobe epilepsy.

For the purpose of precise localization of epileptic foci, combined depth and subdural electrodes were applied to patients with intractable complex partial seizures. To determine speech-related areas, extraoperative functional mapping of the temporal lateral cortex was also carried out through the subdural electrodes. Based on these data, the extent of surgical resections was tailored to include as much of the epileptogenic areas as possible, while preserving the functionally essential zones of the lateral cortex. The results thus acquired have been satisfactory in terms of seizure control and the preservation of speech function.

Dominance, Cerebral↗
PubMed1990

Enhancement of hematopoietic response of mice by intraperitoneal administration of a beta-glucan, SSG, obtained from Sclerotinia sclerotiorum.

Effects of intraperitoneal (i.p.) administration of SSG, a (1----3)-beta-D-glucan obtained from the culture filtrate of Sclerotinia sclerotiorum IFO 9395, on hematopoietic responses of mice were investigated. Numbers of spleen and peripheral leukocytes increased 7 d after administration of SSG (250 micrograms/mouse). The percentages of polymorphonuclear leukocytes (PMN) in both spleen and peripheral blood increased markedly. The numbers of macrophage progenitor cells also increased in both spleens and femurs of the mice administered SSG. Furthermore, levels of colony-stimulating activity (CSA) in sera were elevated, and two peaks were observed (at 6 h and on day 7 after administration). Elevated CSAs were also observed in the cultures of peritoneal cells taken from mice 3 or 6 h after administration of SSG. These results may suggest that i.p. administration of SSG into mice enhanced the production of colony-stimulating factors (CSFs), and then increased the numbers of both spleen and peripheral blood leukocytes.

Animals↗
PubMed1990

Immunohistopathological properties of pleomorphic adenoma in salivary gland.

Fifty-eight salivary gland pleomorphic adenomas and 5 normal salivary glands were studied immunohistochemically with respect to intermediate filaments (keratin, desmin, and vimentin), actin and S-100 protein to observe the cellular differentiation of these tumor cells. Normal myoepithelial cells showed positive immunostaining for actin, vimentin and S-100 protein. Pleomorphic adenomas expressed keratin, vimentin and S-100 protein to various degrees, but only a few tumor cells of pleomorphic adenoma revealed actin. The results indicate that the tumor cells of pleomorphic adenoma show a bipolar differentiation capability of both epithelial and mesenchymal origins, although normal myoepithelial cells show only mesenchymal characteristics. The findings also support previous reports using light and electron microscopy, and also contribute to more precise diagnosis and a better understanding of the histogenesis of this tumor.

Actins↗
PubMed1990

[The use of the bio-pump with an interposed soft reservoir in replacement of descending thoracic aortic aneurysms].

The centrifugal pump (bio-pump) as a temporary shunt during the operation of the descending thoracic aortic aneurysms was used as effective means of providing adequate circulation to the lower body. But in the acute excessive bleeding, estimates of the flow to the abdominal viscera as well as spinal cord are variable. We employed bio-pump with an interposed soft reservoir under low dose systemic heparinization in 2 cases of the descending thoracic aortic aneurysms. Both cases had been maintained adequate flow and perfusion pressure in the time of acute excessive hemorrhage, and there were no evidence of the organ failures due to microembolism. Furthermore, postoperative hemorrhage by using low dose heparin seemed to be unrisky. Compared with the previous method, bio-pump with an interposed soft reservoir provides adequate circulation to the lower body even if acute excessive bleeding occurred.

Aorta, Thoracic↗
PubMed1990

[Contamination and flow speed determination during fluid replacement using newly developed I-cap].

The authors have developed a new cork (I-cap) for transfusion bottle. The I-cap does not require a needle for allowing the air into the bottle. Instead, we put a water-repellent porous filter (W-R filter) made of sintered high molecular weight porous material in it, to allow passage of the air to and from the bottle. The results obtained in experiments designed to determine the contamination and flow-speed with the I-cap, standard cork and soft-bag, were as follow: 1) There was no bacterial contamination when the I-cap was employed, even under high pressure (1.5 atmospheric pressure). 2) Fluid replacement requiring "air-needles" was easily contaminated. 3) Flow-speed, when an I-cap is used, was more stable than when using conventional methods. 4) Flow-speed was most unstable when soft-bags were employed. Thus, the I-cap we have developed, allows the safe use of hard-type infusion bottles, without requiring an "air-needle" and ensuring a steady flow-speed. Our data demonstrate that I-cap can be safely and universally adapted for hard-type infusion bottles.

Equipment Contamination↗
PubMed1989

Tumor necrosis factor as an activator of human granulocytes. Potentiation of the metabolisms triggered by the Ca2+-mobilizing agonists.

TNF stimulated superoxide (O2-) release directly in human granulocytes in a dose-dependent manner (1 to 1000 U/ml), although its potency was weak. TNF-induced O2- release was inhibited by cAMP agonists or ionomycin, and was not accompanied with an increase in cytoplasmic free Ca2+ [( Ca2+]i) and membrane potential changes (depolarization). These findings indicate that neither Ca2+ mobilization nor membrane depolarization is required for TNF-receptor-mediated cell activation. The pretreatment of human granulocytes with TNF enhanced O2- release and membrane depolarization in parallel stimulated by the receptor-mediated Ca2+-mobilizing agonists (FMLP, Con A, and wheat germ agglutinin) or the Ca2+ ionophore ionomycin, but not by PMA, a direct activator of protein kinase C. The optimal effect was obtained by pretreatment of cells with 100 U/ml TNF for 5 to 10 min at 37 degrees C, although the magnitude of enhancement varied according to the agonists used as subsequent stimuli. TNF did not affect an increase in [Ca2+]i stimulated by the Ca2+-mobilizing agonists, except Con A. Con A-induced increase in [Ca2+]i was enhanced by TNF in a dose-dependent manner. These diverse effects of TNF could be partly explained by the exclusive potentiation by TNF of the metabolic events triggered by an increase in [Ca2+]i.

Adjuvants, Immunologic↗
PubMed1989

Immunomodulation by orally administered beta-glucan in mice.

Orally administered SSG, a beta-1,3-glucan obtained from the culture filtrate of the fungus Sclerotinia sclerotiorum IFO 9395, was examined for effects on immune responses in mice. The proliferative responses of spleen cells from SSG-administered mice (40 or 80 mg/kg, daily for 5 or 10 consecutive days) to a T-cell mitogen, concanavalin A (Con A), or a B-cell mitogen, lipopolysaccharide (LPS), were higher than those from normal mice. Oral administration of SSG (80 mg/kg) to mice also enhanced the activities of both natural killer (NK) cells in spleen and the lysosomal enzyme of peritoneal macrophages. Furthermore, significant inhibition of tumor growth was observed in syngeneic tumor systems when SSG was administered directly after tumor implantation. The inhibiting effect required high doses of SSG (over 80 mg/kg). These results demonstrate that SSG can potentiate the immune response of mice following oral administration.

Adjuvants, Immunologic↗
PubMed1989

Zygomatic approach for resection of mesial temporal epileptic focus.

By using the zygomatic approach, temporal mesial and polar epileptic foci are easily accessible through an incision in the inferior temporal gyrus. In this approach, a major part of the superior and middle temporal gyrus is preserved, and there is no risk of postoperative dysnomia even on the dominant side for speech. Combined use of depth and subdural electrodes is advisable for precise determination of focus distributions throughout the mesial and lateral structures of the temporal lobe. We have applied this approach in 5 patients with satisfactory results.

Epilepsy, Temporal Lobe↗
PubMed1989

[Use of Rokitamycin dry syrup in cases of upper deep cervical lymphadenitis and otitis media with exudatives].

Dry syrup of Rokitamycin (RKM.DS), a new macrolide antibiotic with 16-membered ring developed by Toyo Jozo Co., Ltd., was used on cases of upper deep cervical lymphadenitis (UDCL) and of otitis media with exudatives (OME) likely caused by chlamydia infections, and its clinical effects were investigated. 1) In four cases of UDCL (C. psittaci infections), daily doses of 20.0-28.6 mg/kg were administered for 10-42 consecutive days and good efficacies were observed with two cases of excellent results and two cases of good results. 2) In one case of OME (C. trachomatis infection) a daily dose of 30.0 mg/kg was administered for 15 consecutive days and good effectiveness was observed. 3) No side effect was observed in any of the cases. From the above results, it became clear that RKM.DS could effectively used as a therapeutic agent for UDCL and OME in children.

Child↗
PubMed1989

Synergistic Competitive Inhibition of Ferrous Iron Oxidation by Thiobacillus ferrooxidans by Increasing Concentrations of Ferric Iron and Cells.

Oxidation of ferrous iron by Thiobacillus ferrooxidans SM-4 was inhibited competitively by increasing concentrations of ferric iron or cells. A kinetic analysis showed that binding of one inhibitor did not exclude binding of the other and led to synergistic inhibition by the two inhibitors. Binding of one inhibitor, however, was affected by the other inhibitor, and the apparent inhibition constant increased with increasing concentrations of the other inhibitor.

Journal Article↗
PubMed1989

Rate Equations and Kinetic Parameters of the Reactions Involved in Pyrite Oxidation by Thiobacillus ferrooxidans.

Rate equations and kinetic parameters were obtained for various reactions involved in the bacterial oxidation of pyrite. The rate constants were 3.5 muM Fe per min per FeS(2) percent pulp density for the spontaneous pyrite dissolution, 10 muM Fe per min per mM Fe for the indirect leaching with Fe, 90 muM O(2) per min per mg of wet cells per ml for the Thiobacillus ferrooxidans oxidation of washed pyrite, and 250 muM O(2) per min per mg of wet cells per ml for the T. ferrooxidans oxidation of unwashed pyrite. The K(m) values for pyrite concentration were similar and were 1.9, 2.5, and 2.75% pulp density for indirect leaching, washed pyrite oxidation by T. ferrooxidans, and unwashed pyrite oxidation by T. ferrooxidans, respectively. The last reaction was competitively inhibited by increasing concentrations of cells, with a K(i) value of 0.13 mg of wet cells per ml. T. ferrooxidans cells also increased the rate of Fe production from Fe plus pyrite.

Journal Article↗