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N Wakabayashi

Publications and source records attributed to N Wakabayashi.

At least 37 records · Page 2Linked to original sources
PubMed1997

H-aggregation of Methyl Orange at the Interface between the Water Phase and Oil Phase in a Water-in-Oil Microemulsion

Methyl orange dissolved in a water-in-oil microemulsion was examined by UV-VIS absorption spectroscopy and differential scanning calorimetry (DSC). Methyl orange showed two temperature-dependent peaks at 416 and 354 nm in the microemulsion. The former was attributed to a methyl orange monomer, and the latter to aggregates of the dye in the parallel orientation (H-aggregates) at the interface between the water phase and the oil phase in the microemulsion. The position of methyl orange in the microemulsion was verified by DSC analysis.

Journal Article↗
PubMed1997

A short-term clinical follow-up study of superplastic titanium alloy for major connectors of removable partial dentures.

STATEMENT OF PROBLEM: Superplastic forming of Ti-6A1-4V alloy has been used in the fabrication of a removable denture framework. The method provides the titanium alloy denture framework with excellent physical properties not seen in cast titanium prostheses. PURPOSE: This study describes the technical procedure for fabricating removable dentures with this type of framework and evaluates clinical applications of the dentures in short-term follow-up periods from 6 months to 3 years. RESULTS: Results of this study demonstrated that the dentures functioned well and did not cause any major clinical difficulties. The patients have expressed satisfaction with the dentures at regular recall appointments. CONCLUSION: The clinical observations suggest that this method is suitable for fabricating titanium alloy removable dentures.

Acrylic Resins↗
PubMed1997

All-cast-titanium removable partial denture for a patient with a severely reduced interarch distance: a case report.

A patient had a maxillary posterior edentulous area and severely reduced interarch distance that precluded the use of a conventional removable partial denture. An all-cast-titanium denture base and occlusal surface was designed to fabricate a removable denture to restore the edentulous area. Titanium was cast in a centrifugal casting machine with electric are melting design. The desirable characteristics of titanium, such as favorable mechanical properties, low density, and comparatively low cost, make this metal particularly effective and suitable for construction of an all-cast-metal denture base with a metal occlusal surface.

Adult↗
PubMed1995

Isolation and expression of a chicken DNA methyltransferase cDNA.

A 0.5 kb fragment of chicken DNA methyltransferase cDNA was PCR-amplified using a set of degenerate primers. A clone harboring a 5 kb insert was isolated from a cDNA library by screening with the PCR-amplified cDNA fragment as a probe. The elucidated nucleotide sequence gave a 4,614 nucleotide open reading frame, and the predicted protein was highly homologous to the mouse and human DNA methyltransferases, especially in the amino acid sequence of the catalytic domain in the carboxyl-terminal region. The cysteine-rich region and Lys-Gly repeat first found in the mouse sequence were also conserved in chicken. However, about 250 amino acid residues in the amino-terminal portion of chicken DNA methyltransferase diverged from the amino-terminus of the mouse or human sequence. Northern blot analysis showed that the message of chicken DNA methyltransferase was expressed at high levels in the testis, in the lung and in Marek's virus-transformed chicken T-lymphoma cells. Expression of the chicken DNA methyltransferase in COS1 cells demonstrated that the enzyme is a so-called maintenance-type methylase. When poly(dG-dC)-poly(dG-dC) was used as the methyl acceptor, to provide a measure of de novo methylase activity, the Km value for S-adenosyl L-methionine was about 5 microM, which was 10 times higher than that when poly(dI-dC)-poly(dI-dC) was used. The affinity of DNA methyltransferase for S-adenosyl L-methionine in catalyzing de novo-type methylation activity was lower than that in catalyzing maintenance-type activity, though it was still high enough for the enzyme to work as a de novo-type methylase under physiological conditions.

Amino Acid Sequence↗
PubMed1993

[Clinical pharmacology and efficacy of S-1108].

We studied the pharmacokinetics of a new cephem antibiotic, S-1108, in patients with impaired kidney functions. Serum and urinary levels of S-1006 were determined after oral administration of S-1108 at 150 mg to 9 patients with renal dysfunction. In patients with severe renal impairment, high serum levels were maintained over long periods of time. Urinary excretion rates of S-1006 were lower as degrees of kidney failure were severer. S-1108 was administered to treat 27 patients with respiratory tract infections, and its clinical efficacy and safety were evaluated. The clinical efficacies were good in 26 patients, but poor in 1, yielding an efficacy rate of 96.3%. As to adverse reactions; diarrhea was observed in one case. Laboratory tests revealed elevated GOT and GPT in 1, and elevated gamma-GTP in another. These abnormalities, however, were slight and no severe side effects were caused by the drug.

Administration, Oral↗
PubMed1993

[Clinical evaluation and pharmacology of DQ-2556 in the patients with compromised renal function].

We studied the pharmacokinetics of a new cephem antibiotic, DQ-2556, in patients with impaired kidney function. The peak concentrations of the compound in the serum were observed irrespective of the degree of kidney failure 5 minutes after its bolus administration of 1.0 g intravenously, and no significant difference was observed in the concentrations among the patients. On the other hand, the decrease in its concentrations in the serum was impeded in proportion to degrees of kidney failure and, in particular, hemodialysis patients showed markedly delayed clearance of the drug from the serum; the half-lives in the serum (beta phase) were prolonged to ca. 6 hours in patients with severe kidney failure (Ccr ca. 20 ml/min) and did so markedly to ca. 17 to 21 hours in patients with hemodialysis as compared with ca. 2.5 hours in patients with slight kidney failure (Ccr ca. 50 ml/min). Urinary excretion rates (0-to-24 hours values) were ca. 70% in patients with slight kidney failure, ca. 60% in patients with moderate kidney failure and ca. 40% in patients with severe kidney failure, showing a tendency toward a decline in relation to increasing degrees of kidney failure. The compound showed a satisfactory dialytic property. The clinical efficacy and safety of DQ-2556 were evaluated upon administering if at daily doses of 0.5 g b.i.d. and 1.0 g b.i.d. for 7 and 14 consecutive days respectively, in patients with lower respiratory tract infections. The clinical efficacies were excellent in 2 patients, good in 11 and poor in 2, yielding a efficacy rate of 86.7%. No side effects were observed, though, a neutrophil sedimentation ratio decreased in a patient, and a down-shift of prothrombin activities was observed in another. These results suggest that DQ-2556 is useful for lower respiratory tract infections, but in patients with kidney failures it is required to seek the most suitable regimen since the excretion rates of the compound decrease as degrees of kidney failure become severer.

Adult↗
PubMed1993

[Cell proliferation and maturation of ectopic submucosal glands of the stomach].

Stomachs with multiple submucosal glands keep our attention because of their high risk for having gastric carcinomas, but little is known about the relationship between submucosal glands and occurring cancers. So we investigated the structure of submucosal glands including location of proliferating cells. We labeled proliferating cells of three stomachs with cancerous lesions by circulating artificial blood through the isolated organs with bromodeoxyuridine (BrdU). Serial sections of submucosal glands were stained with hematoxylin eosin, periodic acid Schiff, Alcian blue, high iron diamine-Alcian blue, concanavalin A paradox, galactose oxidase Schiff as well as anti-BrdU immunohistochemically. Results showed that most of submucosal glands were composed of functionally matured cells and these cells made regular structure just like those of mucosal layer. Labeling index of BrdU of these submucosal glands were low (0.2%-0.7%). Two atypical glands were seen, and labeling index were 2.6% and 22.2% respectively. In conclusion, submucosal glands of the stomachs were thought to be made by moving proliferating cells from mucosal layer to submucosal layer. So we saw these submucosal glands paracancerous lesions rather than precancerous ones. But we couldn't deny the possibility to occur cancerous lesions from atypical glands in submucosal glands.

Aged↗
PubMed1993

[Analysis of proliferative activity in gastric biopsy specimens by combined BrdU and DNA polymerase alpha immunohistochemistry].

To evaluate correctly the proliferative activity of tumor cells, it is necessary to clarify not only S-phase fraction but also the growth fraction of tumor tissues. We used combined BrdU and DNA polymerase alpha (pol-alpha) immunohistochemistry to gastric biopsy specimens, and analyzed the proliferation of the neoplastic lesions of various degrees of malignancy. The results were as follows: The distribution of pol-alpha positive cells were almost the same as that of BrdU positive cells, but the percentage of pol-alpha positive cells was higher than that of BrdU positive cells irrespective of the mucosal specimens. In the adenomas, both BrdU and pol-alpha positive cells distributed generally superficially in the mucosal layer. In the well differentiated adenocarcinomas, both BrdU and pol-alpha positive cells distributed diffusely in the deeper layer of the mucosa. The ratio of the number of BrdU positive cells to that of pol-alpha positive cells, which means the S-phase fraction in the growth fraction, was higher in the tumor and that higher in the well differentiated adenocarcinomas than that of the adenomas. In conclusion, the combined BrdU and pol-alpha immunohistochemistry in gastric biopsy specimens are useful to evaluate the degree of malignancy.

Adenocarcinoma↗
PubMed1992

Production and characterisation of a human monoclonal thyroid peroxidase autoantibody.

A human-mouse hybridoma has been produced by fusion of Hashimoto thyroid lymphocytes with the mouse myeloma line X63-Ag8.653. The cloned hybridoma secreted 2.5 micrograms per 10(6) cells per day of an IgG kappa thyroid peroxidase (TPO) autoantibody (2G4) with high affinity (2.5 x 10(9) molar-1) and specificity for human TPO. 2G4 did not react with lactoperoxidase, horseradish peroxidase or human myeloperoxidase or with porcine TPO or with human thyroglobulin. Plastic tubes coated with 2G4 bound about 50% of 125I-labelled human TPO added and the binding was inhibited by IgGs prepared from 18/18 TPO autoantibody-positive sera. This indicated that all 18 sera contained autoantibodies which recognised the same (or closely related) epitope as 2G4. Plastic tubes coated with IgGs from different TPO autoantibody-positive patient sera also bound 125I-labelled TPO but inhibition by 2G4 in this system was not complete. This suggested that the sera contained at least 2 types of TPO autoantibodies, with only one type of autoantibody reactive with the same epitope as 2G4.

Animals↗
PubMed1992

[Mechanical property and adaptability of super-plastic titanium alloy denture base].

The purpose of this study is to investigate the mechanical property and the adaptability of the upper complete denture bases made by superplastic forming of Ti-6A1-4V alloy plates which have various thicknesses. The strength of the denture base made by superplastic forming using the 0.55 mm thickness plate was lower than that of the base made by Co-Cr alloy casting in the standard form when loaded on the hard metal board. But by increasing the thickness by partial or full diffusion bonding of two Ti-6A1-4V alloy plates, the denture base became stronger than the Co-Cr alloy base. With resin occlusion rims, all the denture bases were reinforced. Moreover, when loaded on the mastermodel covered with rubber in the residual ridge and palate area, the difference of the strain between the thin and the thick bases became small. However, the strain of the thin base increased particularly when the base had a contact with the mastermodel on a small area in the palate. The superplastic forming denture bases revealed a high adaptability with the space less than 0.13 mm on the average between the base and the mastermodel. And increasing the thickness of the base prevented the worsening of the adaptability after curing resin for the denture.

Biomechanical Phenomena↗
PubMed1992

[Clinical pharmacology and efficacy of levofloxacin in elderly patients].

We studied a newly developed oral quinolone antimicrobial agent, levofloxacin (LVFX, DR-3355), and obtained the following results. 1. Serum and urine levels of LVFX were determined after oral administration of LVFX 100 mg to 11 elderly patients with various degrees of renal function insufficiencies. The patients were classified according to creatinine clearance (Ccr) values into Group I (n = 1, Ccr greater than or equal to 70 ml/min), Group II (n = 4, 40 less than or equal to Ccr less than 70 ml/min), and Group III (n = 6, Ccr less than 40 ml/min). The peak levels of LVFX did not differ greatly among the 3 groups, but in patients with severely impaired renal functions, serum concentrations decreased more slowly than in those with slightly and moderately impaired renal functions, and high serum levels were maintained over a long period. Urinary excretion of LVFX diminished in relation to degrees of renal failure. 2. LVFX was administered to treat 13 elderly patients with respiratory tract infections. Clinical responses were good in all patients with a high efficacy rate of 100%. Laboratory tests revealed eosinophilia in 1 case. The symptom was mild, however, and no severe side effects due to the drug were observed.

Aged↗
PubMed1990

[Bending behavior of superplastic titanium alloy for denture base].

The mechanical behavior of the Ti-6A1 4V alloy denture base made by superplastic forming was studied using various bending tests. The bending strength of the Ti-6A1-4V alloy plate made by superplastic forming was as strong as that of the casting Co-Cr alloy plate with the same thickness. The bending strength of the superplastic forming plate with channels was higher than that of the plain plate. Increase in the arch curvature of the plate decreased the strength, because increase in the arch curvature of the plate decreased the thickness of the superplastic forming plate. Similar results were obtained for the clinical models. The appropriate original thickness for superplastic forming denture base was derived empirically from the experimental values for depth of palate.

Chromium Alloys↗
PubMed1987

[Anatomical observation of the bony and ligamentous structures around the wrist--comparative study of the crab-eating monkey and the human].

So far as we surveyed in the literature, no articles had been published on precise studies on the bony and ligamentous structures around the wrist joint in crab-eating monkey. The authors made an observation about these particular anatomical structures by careful dissection of the 40 crab-eating monkeys, and the results were compared with those of three fresh human cadavers. The most significant differences were that the monkey had nine carpal bones (os centrale in addition), quite different configuration of the pisiform bone, no radio-scapho-capitate ligament, hypoplastic or no radio-scapho-lunate ligament, and different structure of the triangular fibro-cartilage complex. We discussed these differences from the view point of functional anatomy.

Adult↗