Search PubMed⌕ Search

Biomedical subjects

M Okazaki

Publications and source records attributed to M Okazaki.

At least 415 records · Page 23Linked to original sources
PubMed1989

Identification by monoclonal antibody of the tumor antigen of a human autologous breast cancer cell that is involved in cytotoxicity by a cytotoxic T-cell clone.

We have already established a pair of human autologous clones, tumor-specific cytotoxic T-lymphocyte clone TcHMC-1 and tumor target clone HMC-1-8, that were derived from the metastatic pleural effusion of a patient with mammary carcinoma. In this paper, we describe the target antigen that was defined by monoclonal antibody 3A2. This monoclonal antibody selectively inhibited the cytotoxic action of TcHMC-1 against HMC1-8 autologous tumor target cells, but not the cytotoxicity of lymphokine-activated killer and possibly natural killer cells against HMC-1-8 cells. Western blot analysis using the 3A2 monoclonal antibody identified a molecule with an approximate molecular weight of 92,000. This antigen was highly expressed on autologous primary cancer cells of breast carcinoma tissue, but not on the normal mammary gland in the same patient. Moreover, this antigen can be detected on approximately 50% of human allogeneic breast carcinomas, but not on other neoplastic tissues such as gastric and colonic carcinomas except for one out of 10 prostatic carcinomas. Nonneoplastic normal cells did not express this antigen. It was also suggested that the antigen is not murine mammary tumor virus-related products. These data suggest that 3A2-defined antigen could participate in the cytotoxicity by human autologous cytotoxic T-lymphocytes as the target molecule expressed on tumor cells.

Antibodies, Monoclonal↗
PubMed1989

Close linkage of MEN2A with RBP3 locus in Japanese kindreds.

The gene responsible for multiple endocrine neoplasia type 2A (MEN2A) has recently been assigned to the pericentromeric region of chromosome 10 in European Caucasian kindreds by linkage analysis using a DNA marker, interstitial retinol-binding protein 3 (RBP3). We have found tight linkage between the MEN2A and RBP3 loci in Japanese MEN2A kindreds. The maximum lod score is 5.19 at a recombination fraction of 0.00. This result suggests that mutation of a certain gene close to RBP3 is responsible for MEN2A irrespective of ethnic backgrounds.

Female↗
PubMed1989

Reaction of Ca2+ and phosphate ester.

The reaction of calcium ions and organic phosphate ester monomer at varying pHs was examined. Above pH 10, poorly crystallized hydroxyapatite was formed, which had lower crystallinity than that synthesized with inorganic phosphate as a source of P under the same conditions. On the other hand, the results of X-ray diffraction, chemical analysis, infrared absorption analysis and differential thermal analysis suggested that, crystalline organic calcium phosphate ester was formed below pH 10, whilst for the synthesis with inorganic phosphate hydroxyapatite was formed at pH 7.4.

Calcium↗
PubMed1989

Insolubilization of apatite-collagen composites by UV irradiation.

The physico-chemical properties and biocompatibility of insolubilized apatite-collagen composites were examined. A carbonate-containing hydroxyapatite with chemical composition and crystallinity similar to that of bone was synthesized at pH 7.4 and 60 degrees C. The apatite powder was mixed with collagen solution, whose antigenicity had been removed by enzymatic treatment and formed into apatite-collagen pellets. After insolubilization by UV irradiation for 4 h, the composites showed remarkably reduced disintegration and showed good biocompatibility when implanted into rat abdomen.

Animals↗
PubMed1989

Carbachol-induced cosecretion of immunoreactive atrial natriuretic peptides with catecholamines from cultured bovine adrenal medullary cells.

The distribution and secretion of atrial natriuretic peptides (ANPs) were investigated in bovine adrenal medulla. (1) Cultured bovine adrenal medullary cells (2 x 10(6)/dish) contained 100.4 +/- 6.0 fmol of immunoreactive ANP (IR-ANP) and 207.3 +/- 6.6 nmol of catecholamines as epinephrine plus norepinephrine. (2) Stimulation of nicotinic but not muscarinic acetylcholine receptors caused a cosecretion of IR-ANP and catecholamines corresponding to the ratio of IR-ANP to catecholamines in cultured bovine adrenal medullary cells. (3) Carbachol-stimulated secretion of IR-ANP was dependent on the presence of extracellular Ca2+. (4) Chromaffin granules isolated from bovine adrenal medulla contained large amounts of IR-ANP and catecholamines, in the same ratio as did cultured adrenal medullary cells. (5) Reverse-phase HPLC analysis showed that both stored and secreted IR-ANP consisted of two components, which eluted at the position of ANP(99-126) or ANP(1-126). These results indicate that ANPs are stored as ANP(99-126) and ANP(1-126) in chromaffin granules, and are cosecreted in parallel with catecholamines in a Ca2+-dependent manner by the stimulation of nicotinic acetylcholine receptors.

Adrenal Medulla↗
PubMed1989

Near UV-induced free radicals in ocular lens, studied by ESR and spin trapping.

An electron spin resonance (ESR) study on UV-photolysis of human and canine lens nuclei was carried out at room temperature. (1) At least two kinds of free radical signals, a narrow signal and a broad one, were detected at around g = 2.004. The latter is similar to that observed upon irradiation of a model solution containing both tryptophan and cysteine. (2) Two spin adducts were detected upon irradiation of canine lens in the presence of a spin trapping reagent (DMPO, 5,5-dimethyl-1-pyrroline N-oxide), i.e. a spin adduct of sulphur-centered radical (most likely glutathione thiyl radical) and the protonated adduct of solvated electron (presumably due to photo-ionization of tryptophan). (3) A tentative and simplified reaction mechanism of UV-induced damage is discussed on the basis of these observations.

Animals↗
PubMed1989

[Studies on retainer's effect on unilateral designs of mandibular unilateral distal extention dentures. 1].

The dispersion of occlusal forces around both the abutment teeth and the alveolar mucosa is generally considered as an most important principal in minimizing the denture mobility and the local over-load on designing the distal extention-type denture. This study was undertaken to investigate the principal factors in designing uni-lateral-type clasp denture equipped with direct and indirect retainer. Our data show: 1. Guide-plane provides maximam retention power in cooperation with high fixable indirect retainer. 2. Direction of load and design of the denture are the major responsible factors for shifting the horizontal rotation center of denture body. Especially the shape of indirect retainer was demonstrated to alter direction and amount of displacement of the denture base and abutment teeth. 3. Most types of uni-lateral distal extention denture exhibited upward and downward movement when they function in vivo. 4. Negative type indirect retainer plased at incisor was shown to be harmful due to its intrinsic slunting force on teeth to labial direction. On the other hand positive type indirect retainer was considered to be more desirable because the force through clasp moves abutment teeth vertically.

Alveolar Process↗
PubMed1989

[Specific physicochemical properties of apatites. 9. Organic phosphate ester monomer as a source of P].

Reactions of calcium ions and organic phosphate ester monomers were examined at 60 degrees C and 80 degrees C and at various pH. By a modification of the method used for HAp synthesis, calcium acetate was fed into aqueous solution of mechanically stirred mono (methacryloyloxyethyl) acid phosphate. Above a pH of 10, poorly crystallized hydroxyapatite was formed with lower crystallinity than that synthesized with inorganic phosphate as a source of P under the same conditions. This result suggested that phosphate ester and/or decomposed acrylic monomer may inhibit the diffusion of Ca2+ and PO4(3-) and the formation of the apatite crystal. On the other hand, the results of X-ray diffraction, chemical analysis, and infrared absorption analysis suggested that crystalline organic calcium phosphate ester was formed below pH 10, while in synthesis with inorganic phosphate, hydroxyapatite was formed at pH 7.4.

Calcium Phosphates↗
PubMed1989

Crystal growth of fluoridated hydroxyapatites inhibited in the presence of gelatin.

Three types of fluoridated hydroxyapatites were synthesized in the presence of low concentrations of gelatin solution. The crystallinity of gelatin-free fluoridated hydroxyapatites increased at high degree of fluoridation, after it showed complex behavior at lower fluoride content. However, increasing of gelatin concentration in the solution, the crystallinity decreased, especially at high fluoride content. Chemical analysis and a- and c-axis dimensions showed no significant difference among those series, and gelatin contents in the precipitates were negligible when compared with the supplied amounts. These results suggest that gelatin may inhibit the crystal growth of fluoridated apatites only as a surrounding factor, overcoming the promoting action of fluoride.

Collagen↗
PubMed1989

[Therapeutic effect of stage III breast cancer--comparative study of preoperative intra-arterial infusion chemotherapy and non-infusion therapy].

Between January 1977 and March 1988, 111 patients of stage III breast cancer were treated in Sapporo Medical College. The median age was 51.6 years (range, 26-83 years). Menopausal status was 47 cases of premenopausal, 19 cases of perimenopausal and 45 cases of postomenopausal. Fifty-seven of these patients received intra-arterial infusion chemotherapy. The anticancer drugs were mainly given by two routes, infusion into the internal mammary artery and the subclavian artery. Continuous infusion of 5-FU and intermittent injections of MMC, ADR or 4'-epi-ADR were jointly or individually made in each artery. Clinico-histological response was studied in 53 out of 57 patients. Clinical response, defined as CR + PR, was noted in 33 patients (62.3%). Histological response according to Shimosato Criteria, defined as grade IIb or better, appeared in 31 patients (58.5%). Non-infusion group contained 27.7% of stage IIIb, against 72.2% in infusion group. The 5-year overall survival rates were; non-infusion group 62%, 5-FU infusion group 34.1%, and ADR MMC group 66.2%. A significant difference was seen between 5-FU infusion group and ADR-MMC group (p = 0.03). The median disease-free interval was 22.0 months (range, 1-77 months) in infusion group and 28.2 months (range, 1-124 months) in non-infusion group. MMC + ADR combination group revealed the most excellent results in terms of the 5 year survival rate and clinicohistological effect.

Adult↗
PubMed1989

[Computer graphics of apatite crystals].

Hydroxyapatite was studied by computer graphics. The data of structural coordinates of hydroxyapatite crystal was put into a protein graphics program in A units. The connection of each element, with what comes front and rear, was displayed by the shade-line erasing method, and the solid-image was expressed by the degree of lightness from the light source. The tint of color was drawn by Raster graphics method. A fine picture can be obtained with the program. Rotating the graphics freely in an angle around X, Y or Z axis, gives a view from any direction. Crystal graphics model of fluoridated hydroxyapatite, in which F- ions substituted in part into OH- position, was also drawn.

Computer Graphics↗
PubMed1989

[A long surviving hepatocellular carcinoma case (2 years 1 month) with tumor thrombus in the portal trunk treated by embolization].

A 55-year-old male patient suffered from hepatocellular carcinoma (HCC) with tumor thrombus in the portal trunk and cavernous transformation in the liver hilus. He was treated 4 times effectively by transcatheter arterial embolization (TAE). Tumor thrombus in the portal trunk which was demonstrated by portography before TAE disappeared following initial TAE. He is still alive 2 years and 1 month after initial TAE. We reported a long surviving case with advanced HCC treated by TAE and TAE for advanced HCC was discussed.

Carcinoma, Hepatocellular↗
PubMed1989

Allele loss on chromosome 10 and point mutation of ras oncogenes are infrequent in tumors of MEN 2A.

The multiple endocrine neoplasia type 2A (MEN 2A) gene has been mapped to the centromeric region of chromosome 10 by linkage analysis. We examined 36 medullary thyroid carcinomas (MTCs) (16 hereditary and 20 sporadic) and ten pheochromocytomas (eight hereditary and two sporadic) to detect loss of alleles on chromosome 10 using seven polymorphic DNA markers mapped to this chromosome. Of 20 informative cases, only one (5%) sporadic MTC showed loss of heterozygosity at the locus RBP3. Allele loss at the RBP3 locus was not found in pheochromocytomas from six heterozygotes. All tumors retained constitutional heterozygosity at six other loci on chromosome 10 (D10S17, D10S34, D10S24 on the short arm, D10S15 in the pericentromeric region, D10S20, and D10S4 on the long arm). Our findings suggest that the second hit for tumorigenesis in MEN 2A may not be loss of function of the normal allele at the homologous locus on the other copy of chromosome 10. Mutated ras oncogene was found only in one of 18 MTCs at the codon 61 of H-ras.

Adrenal Gland Neoplasms↗
PubMed1989

[An acoustical analysis of TMJ sounds and its clinical importance].

The aim of this report was to establish a method for objective examination of TMJ sounds which is required for preventive care of the TMJ dysfunction, and to confirm its clinical importance by means of analysis of mandibular border movement and EMG. The subjects for the acoustical analysis of TMJ sounds consisted of 13 temporomandibular joints as the clicking group, 4 as the crepitus group, and 11 as the control group. The subjects for the analysis of the mandibular movement and EMG consisted of 8 adults with clicking as the clicking group and 11 without TMJ sounds as the control. The results obtained were as follows: 1. Clear and stable TMJ sounds waves could be recorded from the external auditory meatuses. 2. Clicking sounds waves showed a sharper rising and shorter duration than crepitus sounds waves. Comparing the three groups on the basis of the data of power spectrum analysis of frequencies using FFT, the spectrum of frequencies of the crepitus group was the highest and broadest, and that of control group was the lowest. 3. The deviation of the trace of mandibular border movement in the clicking group tended to be larger than in the control group. 4. In the clicking group, the frequency of occurrence of the silent period of EMG bursts during tooth tapping was lower and the duration of the silent period was shorter than in the control group. Duration, interval and cycle of EMG bursts during gum chewing in the clicking group was longer than in the control group. 5. From the above, it was suggested that the ones with TMJ sounds had the TMJ dysfunction latently, therefore it was considered valuable to use an analysis of TMJ sounds in the examination for the preventive care of the TMJ dysfunction.

Humans↗
PubMed1989

Thermal oxidation effect on porcelain-titanium restoration.

Titanium has good corrosion resistance, light density, high strength and excellent biocompatibility. Conventional ceramicmetal restorations were used extensively in dentistry because of their esthetic appearance and good strength properties. The purpose of this study was to investigate the influence of various thermal treatments on the bond strength and physical properties of the porcelain-titanium system. Pure titanium was treated in a porcelain furnace at temperatures ranging from 600 to 1000 degrees C, under vacuum and in air, respectively. X-ray diffraction analysis revealed that the relative peak intensity of alpha-Ti was decreased, while the TiO2 was increased when raising the firing temperature. The vickers hardness number was increased at elevated temperatures, especially over 900 degrees C, and firing in air was harder than under vacuum. The tension-shear bond strength was highest in the green stage and lowest in the 1000 degrees C treated group. The metallographic microscopic of the porcelaintitanium interface revealed a thick band-like zone in the 1000 degrees C treated sample. Therefore it seems that the excess oxidation layer of TiO2 weakened the bond strength of porcelain-titanium. Contrary to the conventional ceramic-gold alloys system, the recommended degassing procedure was not suitable for the porcelain-titanium restoration.

Dental Porcelain↗
PubMed1989

[T-cell lymphomas of the skin: a study of 7 cases excluding mycosis fungoides and adult T-cell leukemia/lymphoma].

Seven cases of T-cell lymphomas of the skin, excluding mycosis fungoides and adult T-cell leukemia/lymphoma, treated at the Department of Dermatology, Miyazaki Medical College for the previous 5 years were studied. Five were males and 2 were females, with a mean age of 61 years. Six patients presented either multiple skin tumors or subcutaneous indurations. Histologically, all cases presented dense infiltrations of the tumor cells showing variable morphological characteristics. Surface markers were also variable, suggesting that these were not a single entity. Treatment consisted of chemotherapy in 5 cases and electron beam therapy in 5 (localized in 4 and generalized in 1). Complete remission was obtained in 5 cases. The mean period from the first examination to death in the three fatal cases was 11.7 months, and the mean period of observation from the first examination to the present time in 4 cases ranged from 12 months to 40 months. Clinicopathological characteristics of these cases were compared with those of adult T-cell leukemia/lymphoma.

Adult↗