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M Toyoda

Publications and source records attributed to M Toyoda.

At least 181 records · Page 10Linked to original sources
PubMed1994

[Comparison of several fluorescence HPLC methods for fumonisin analysis].

Fumonisin has no particular cromophore groups in its chemical structure applicable for trace analysis, and therefore requires derivatization prior to measurement. Currently, the analysis of fumonisin B1 (FB1), B2 (FB2) is generally carried out after derivatizing FB1 mainly with o-phthalaldehyde to make a fluorescent compound (OPA-F). The OPA-F is, however, not sufficiently stable for precise analysis, and we have thus examined other fluorescent derivatives including fluorescamine, FMOC, NBD-F and DBD-F. The analytical method using FMOC as fluorescent agent required column chromatography after the derivatizing reaction, while reaction of FB1 with fluorescamine gave two chromatographic peaks. FMOC and fluorescamine are accordingly not desirable as fluorescent agents for analysis of small quantities of FB1 and FB2 in foods. In conclusion, for precise analysis of such trace amounts of FB1 and FB2, NBD-F or DBD-F should be used as fluorescent agents.

4-Chloro-7-nitrobenzofurazan↗
PubMed1993

Tracheobronchial AL amyloidosis: histologic, immunohistochemical, ultrastructural, and immunoelectron microscopic observations.

We have studied three cases of localized amyloidosis in the lower respiratory tract. Amyloid was nodularly or diffusely deposited in the lamina propria of the tracheobronchial mucosa. Its nature was confirmed by Congo red staining with green birefringence on polarized microscopy. "Tracheobronchopathia osteoplastica" also was demonstrated. Plasma cells and lymphocytes were scant in the amyloid mass. Few fibroblasts and even fewer macrophages were seen. The number of plasma cells was not increased in the bone marrow in any of our cases. Amyloid fibrils were demonstrated by electron microscopic examination. The amyloid P component was detected by immunohistochemical methods. The precursor protein of amyloidosis was shown to be amyloid L protein by the postembedding protein-A gold technique with anti-light chain antisera. The role of the plasma cells in amyloid formation, however, could not be ascertained. Based on these observations, amyloid fibril formation in tracheobronchial amyloidosis appears to be related to light chains secreted by local plasma cells, combined with amyloid P, calcium, and other factors.

Adult↗
PubMed1993

Suppression of intestinal smooth muscle contraction by 4-ethylguaiacol, a constituent of wood creosote.

Wood creosote, a mixture of phenolic compounds, suppresses in vitro contractions of rat intestine. To identify a compound in wood creosote able to inhibit intestinal motility, we screened its constituent phenolic compounds and found 4-ethylguaiacol (4-EG) as an active compound. It suppressed the spontaneous phasic (IC50 = 513 +/- 48 mumol/l) as well as spasmogenic-agent-induced tonic longitudinal contractions of isolated rat ileum in a reversible and concentration-dependent manner. KCl-depolarization-induced tonic contraction, which was susceptible to a calcium channel blocking agent, was also suppressed by 4-EG with an IC50 of 433 +/- 41 mumol/l. Furthermore, calcium-ionophore-induced contraction, which was affected by an influx of extracellular calcium ion that bypassed calcium channels, was suppressed by 4-EG with an IC50 of 97 +/- 18 mumol/l. These results support the concept that the effect of wood creosote to suppress intestinal motility is attributable, partially or entirely, to its component 4-EG and that this effect of 4-EG on the intestinal muscle is produced at some stage(s) of the muscle contraction process after influx of extracellular calcium into the cytosol of smooth muscle.

Animals↗
PubMed1993

[Phacomatosis].

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Adolescent↗
PubMed1992

Suppression of intestinal smooth muscle contraction by phenolic compounds.

Wood creosote, a mixture of guaiacol, creosol, and other related phenolic compounds, suppresses the spontaneous longitudinal phasic contractions of an isolated rat ileal segment. Thirty-two phenolic compounds were screened for this activity to identify the active substances in wood creosote. Of the 32 compounds tested, 2,3,6-trimethylphenol, 2,4,6-trimethylphenol, and 4-ethylguaiacol were most effective and their respective IC50 values were 0.035, 0.037, and 0.043 mM. Guaiacol and creosol, the chief constituents of wood creosote, were moderately effective and their respective IC50 values were 0.18 and 0.13 mM. Other phenolic compounds in wood creosote also suppressed the ileal contraction although their IC50 values differed markedly from each other. These results suggest that practically all of its constituent phenolic compounds contribute to wood creosote's capacity to suppress ileal contraction.

Animals↗
PubMed1991

Length of the human umbilical cord in multiple pregnancy.

The factors controlling the length of the human umbilical cord are uncertain. In the generally accepted 'tension theory', the length of the umbilical cord is proposed to increase the tensile force on it in the uterus. The greatest tensile force is supposed to be fetal movement. If this is so, the length of the umbilical cord should be shorter in multiple pregnancy than in single pregnancy. To examine this possibility we measured the umbilical cord lengths in 3314 singleton births, 82 twins births (164 infants), and 11 triplet or quadruplet births (35 infants). The cord lengths in multiple pregnancies (twins 51.3 cm, triplets and quadruplets 50.1 cm) tended to be shorter than that in singleton pregnancies (57.2 cm). However, no significant difference was found in the ratio of the umbilical cord length to the infant body weight in these groups. Therefore, we conclude that an important factor in determining the cord length is the size of the infant.

Body Weight↗
PubMed1991

Characterization of AL amyloid protein identified by immunoelectron microscopy: a simple method using the protein A-gold technique.

The classification of amyloidosis depends on the chemical nature of the specific amyloid protein involved. Because AL amyloid protein consists mainly of variable regions of light chain (LC), immunohistochemical staining with conventional anti-LC antisera cannot identify its protein. We were able to classify three cases of AL amyloidosis, including one case of AL-kappa LC and two cases of AL-lambda LC, using post-embedding protein A-gold immunoelectron microscopy on autopsy-derived tissues. We describe here our procedure in which a protein A-gold staining apparatus was used. The main advantage of this method is that many sections can be stained and washed simultaneously under the same conditions. These results suggest that the post-embedding protein A-gold technique using conventional kappa or lambda LC may be useful in diagnosing AL amyloidosis.

Amyloid↗
PubMed1991

Characterization of contaminants in EMS-associated L-tryptophan samples by high-performance liquid chromatography.

To identify chemical contaminant(s) associated with eosinophilia-myalgia syndrome (EMS), case and control lots of tryptophan were analyzed by HPLC with both UV and FL detection. Numerous contaminant peaks appeared on the chromatograms and some of them were identified as 5-hydroxytryptophan, indol aldehyde, indol, etc; from the retention time of authentic compounds. Among these, three peaks were significantly associated with case lots. One corresponds to di-tryptophan aminal of aldehyde (peak E). Others are unknown contaminants, UV-5 (FL-7) and UV-28 (FL-36). The structural elucidation and toxicological implication of UV-5 (FL-7) are currently in progress.

Chromatography, High Pressure Liquid↗
PubMed1990

Serum interleukin-2 levels in a patient with focal segmental glomerulosclerosis. Relationship to clinical course and cyclosporin A therapy.

We describe a patient with steroid-resistant focal segmental glomerulosclerosis (FSGS) whose serum interleukin-2 (IL-2) levels were markedly elevated in association with disease activity. With cyclosporin A (CsA) treatment, the patient entered remission and serum IL-2 fell to undetectable levels. After cessation of CsA, the patient relapsed and the serum IL-2 levels were elevated again. Reinstitution of CsA therapy was followed by a partial remission and disappearance of detectable serum IL-2 levels.

Cyclosporins↗
PubMed1990

Exogenous interleukin-2 does not reverse the immunoinhibitory effects of 1,25-dihydroxyvitamin D3 on human peripheral blood lymphocyte immunoglobulin production.

1,25-Dihydroxyvitamin D3 (1,25-D3) is known to have potent inhibitory effects on human peripheral blood mononuclear cell (PBMC) functions. Previous experiments suggest that addition of interleukin-2 (IL-2) to cell cultures can reverse the antiproliferative action of 1,25-D3. Previous studies have also shown that the CD4+ T-cell subset is more sensitive to the antiproliferative actions of 1,25-D3 than are the CD8+ T-cells. The objective of this study was to determine whether exogenous IL-2 could reverse the antiproliferative and immunoinhibitory action (inhibition of Ig production) in mitogen-activated PBMC cultures and in fluorescein-activated cell sorting (FACS) experiments where CD8+ T-cells were removed from PBMCs before mitogen stimulation with/without exogenous IL-2 added. In these studies, addition of IL-2 to mitogen-activated, 1,25-D3-treated PBMCs allowed the cells to overcome the 1,25-D3 suppressive effect on cell proliferation. However, exogenous IL-2 did not overcome the 1,25-D3-mediated inhibitory effect on PBMC Ig production. Using FACS lymphocyte populations (CD4+, CD8+ and B-cells), we showed that CD4+ T-cell-directed Ig synthesis in co-culture with autologous B-cells was inhibitable by incubation of cells with 1,25-D3, but Ig synthesis was restored to near-normal levels by addition of exogenous IL-2. This clearly contrasts with the inability of Il-2 to reverse the 1,25-D3 inhibitory effect on Ig synthesis in PBMCs. In other experiments, when CD8+ cells were removed from mitogen-stimulated, 1,25-D3-treated PBMCs, addition of exogenous IL-2 resulted in a full reversal of the 1,25-D3-mediated Ig inhibition. These data suggest that the inability of IL-2 to reverse the inhibitory effects of 1,25-D3 on PBMC Ig production is probably a result of a lack of sensitivity of CD8+ T-cells to the antiproliferative and immunoregulatory actions of 1,25-D3. This is possibly because of a differential expression of 1,25-D3 receptors on CD4+ and CD8+ T-cells.

B-Lymphocytes↗
PubMed1990

Metabolic and hematologic effects and immune complex formation related to pertussis immunization.

Selected metabolic, hematologic, and immunologic functions were evaluated in 3- to 6-mo-old Finnish infants who received whole-cell pertussis-component diphtheria and tetanus toxoids and pertussis vaccine, adsorbed (DTP) vaccine, and in 4- to 6-y-old Los Angeles children who received either a licensed DTP vaccine or an acellular pertussis component DTP vaccine. One d after immunization, there was an increase in total leukocytes and neutrophils and a decrease in lymphocytes in all vaccinees. In 4- to 6-y-old children the leukocytosis and neutrophilia were greater in recipients who received the standard DTP vaccine than in vaccinees who received an acellular pertussis component DTP vaccine. In infants there was an increase in the mean plasma insulin concentration but no change in the glucose concentration 24 h after immunization; no increase in the mean plasma insulin was noted in the 4- to 6-y-old children. Three 4- to 6-y-old vaccinees had higher circulating immune complex concentrations after immunization and two of these children had high clinical reaction scores. The etiology of adverse reactions after DTP immunization is multifactorial. In contrast with findings in animals, our findings do not demonstrate a clinically significant effect due to lymphocytosis-promoting factor on glucose metabolism in vaccinated children. Neutrophilia in vaccinees is probably due to endotoxin, and some reactions may be due to circulating immune complexes.

Antigen-Antibody Complex↗
PubMed1990

[Studies on chemical analysis of mycotoxin (XXI). A rapid analytical method for aflatoxins by immunoaffinity column chromatography and high performance liquid chromatography].

An analytical method for aflatoxins using solvent extraction, affinity column (containing monoclonal antibodies against aflatoxins bound onto agarose) clean-up and high performance liquid chromatographic determination was applied to the analysis of aflatoxins in peanuts, pistachio nuts, white and black peppers and corn. Recoveries of aflatoxins B1, B2, G1 and G2 spiked to peanuts, pistachio nuts and corn at the level of 20 ppb were 77.4-81.4, 70.1-77.9 and 72.3-94.8%, respectively. In the case of white and black peppers, because the spiked aflatoxin recovery rate was low, further purification steps should be studied. The stability of the affinity column was good. This procedure is recommended as a rapid and reliable method for the analysis of aflatoxins in the three kinds of foods, peanuts, pistachio nuts and corn.

Aflatoxins↗
PubMed1990

A study on the impression materials using for the mannequin practice.

The mannequin exercises which are practiced in clinical exercises of dental colleges are getting more important these days. It is necessary to compare the difference between the efficiency of a mannequin and a living body. When making a partial denture using the simulation model, it is very important to know what kind of impression materials you are able to use or the accuracy of those impression materials. A study on a simulation model is used for making a partial denture. Choosing some sort of impression materials and treatment positions have the possibility to exert influence on impression taking through the process from impression taking to model making. At first, to find the impression materials which are able to take the impression of simulation model's simulate mucous membrane, choose nine impression materials and examined them. Then, examine the effective relationship between the impression taking and the mannequin's head and back position. Establish a mannequin's head and back inclination from four positions. Cut the acquired four models at the same location and examine them. The following results were obtained. 1. Of the impression materials used, with the exception of Flexicon and Rapid, there was no adhesiveness observed with the artificial mucosa. In addition, in the case of Exaflex Injection, Regular and Putty, there were noninduration sections among the sections that contacted with the artificial mucosa. 2. Regarding the effect of the bodily position, changes in the impression were observed for the upper jaw in the case of the median sagittal section C and the lateral section S. This was particularly frequent on the palate in the molar region.(ABSTRACT TRUNCATED AT 250 WORDS)

Dental Impression Materials↗
PubMed1990

[A study of linearity and reciprocity during shock applied with a hammer to human dry skull].

The authors used a human dry skull on which the cranial bone mandible had been joined with an artificial articulator disk to form a single unit. Impact acceleration corresponding to weak and strong tapping was considered a dynamic load in examining the vibration transfer characteristics of the facial cranial bone when impact was applied from the mentum section in a situation designed to be closer to reality. Flexion injection type (resonance frequency f0 = 100 to 150 Hz, produced by GC Corp.) was applied to the human dry skull as an artificial periodontal membrane at thickness of 0.3 mm. In addition, Exaflex heavy body type (f0 = 400 Hz, produced by GC Corp.) was applied as an artificial disk. This was then placed on a damper produced by spreading a rubber dam sheet with a thickness of 35 microns on a tire tube with a diameter of 35 cm and an air pressure of 35 kg/cm2. Investigations were then made concerning linearity and reciprocity to determine whether an experimental system could be achieved or not. This was then followed by modal analysis. As a result, the following matters were ascertained: (1) The resonating area differed according to the extent of the force. (2) An increase in the viscoelastic elements of the silicon was accompanied by attenuation of force. (3) Directionality of force attenuation was caused by the complexity of bone structure. (4) A tapping force of 0.3G or 1G was sufficiently attenuated by the facial cranial bone. (5) The transfer function at the bone seams and thinner areas of the bones was insufficient for modal analysis of the facial region and total cranial bone of the human dry skull.

Biomechanical Phenomena↗
PubMed1990

[A case of tuberculous arthritis of shoulder].

A rara case of tuberculous arthritis of right shoulder was reported. Plain X ray and CT showed bone destruction in humerus and glenoid process and soft tissue swelling with calcification was also demonstrated. T2 weighted images showed extension of abscess clearly. And extension to bone marrow was showed on CT and T1 weighted MR images.

Arthritis, Infectious↗