Biomedical subjects

T Okabe

Publications and source records attributed to T Okabe.

At least 163 records · Page 9Linked to original sources

PubMed1996

Truncation at the C-terminus of the DAX-1 protein impairs its biological actions in patients with X-linked adrenal hypoplasia congenita.

The DAX-1 [DSS (dosage-sensitive sex)-AHC critical region in the X, gene 1] gene has been reported to be responsible for X-linked adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism. However, the function and structure of the DAX-1 protein have not been characterized. In this study, molecular analysis of the DAX-1 gene from 6 patients with AHC, including 2 siblings, identified 5 novel mutations with 3 nonsense mutations and 2 frameshift mutations. Case 1 had a nonsense mutation at position 395 (Q395X). Cases 2 and 3, who were siblings, had a nonsense mutation at position 91 (Y91X). Case 4 had a 2-base deletion (AT) at nucleotides 1610 and 1611 and a 1-base insertion (G) resulting in a premature stop codon at position 462 (1610-1611 del AT ins G). Case 5 had a nonsense mutation at position 271 (Y271X). Case 6 had a 1-base deletion (C) at nucleotide 1169, which induced a frame shift and a premature stop codon at position 371 (1169 del C). All mutated DAX-1 proteins had truncated C-terminal domains. In addition, reverse transcription-PCR and direct sequencing characterized the mutant messenger ribonucleic acid in testis from case 1. Our results suggest that these 5 novel mutations are responsible for X-linked AHC and that the C-terminus of the DAX-1 protein, especially the terminal 11 amino acids, is necessary for normal adrenal cortical embryogenesis.

Adolescent↗

PubMed1996

Oculopharyngeal muscular dystrophy in two unrelated Japanese families.

The occurrence of oculopharyngeal muscular dystrophy (OPMD) in Orientals is uncertain. We identified two unrelated Japanese families, including 30 affected individuals (14 men, 16 women, mean age 58 years) of OPMD through four generations, with complete penetrance. Their major clinical manifestations were late-onset bilateral ptosis and dysphagia. Histologic studies of slightly affected muscles reveal mild myogenic changes, occasional rimmed vacuoles, and small angulated fibers. By contrast, the severely involved cricopharyngeal muscle showed marked loss of fibers and massive proliferation of connective tissue. Ultrastructural studies of four different biopsied muscles disclosed subsarcolemmal intranuclear tubulofilamentous inclusions, identical to those of non-Japanese OPMD patients.

Aged↗

PubMed1996

Initial mercury evaporation from amalgams made with in-containing commercial alloys.

This study examined the Hg evaporation behavior during the early setting of amalgams that contain In in the alloy powders. Two different types of commercially available In-containing alloys were tested: an In-particle admixed powder (Indisperse, D) and an In-containing single-composition powder (Indiloy, S). Mercury evaporation from specimens (4 mm in dia, 8 mm tall) was monitored 10 min after trituration to 180 min using a mercury vapor analyzer according to the methods used in a previous study. The amounts released from 10 min to 180 min were compared with the results of our previous study on a single-composition amalgam (Tytin, T) with pure Hg and with Hg-In liquids (5 or 10%). Amalgam S and In-containing T terminated Hg evaporation within 180 min. There was no significant (p > 0.05) difference in the amount released between T amalgam made using pure mercury and D, and between T amalgam made with 5% In-containing mercury and S amalgam. Mercury release from amalgam D was significantly (p < 0.05) higher than from S or both types of In-containing T amalgam. Adding In to mercury or alloying In into the alloy particles appeared to be more effective in reducing the mercury vapor than admixing pure In particles into the amalgam.

Analysis of Variance↗

PubMed1996

Titanium in dentistry: development and research in the U.S.A.

Titanium has received a great deal of attention from dental researchers and clinicians. In the United States, the history of the application of titanium as a biomaterial started as early as 1940 when experiments with titanium implants were done using laboratory animals. It appears that in 1959, two American researchers were the first to suggest casting titanium to fabricate implant posts. The use of cast titanium for dental prostheses in the U.S. was first reported in 1977. The present survey revealed that during the last decade, the number of research projects on the applications of titanium to dentistry that were presented at annual IADR/AADR meetings has steadily increased. The majority of these presentations have been made by American researchers, and 59% of these were related to dental implantology. The numbers of reports on casting and prosthodontic applications have steadily increased, but they are still more limited. The purpose of this review was to provide information on the development and the current status of research on titanium in dentistry in the U.S.

Dental Casting Technique↗

PubMed1996

[A case of carcinomatous peritonitis for which combination therapy of 5-FU, leucovorin and cisplatin was effective].

This case report describes a case of carcinomatous peritonitis which showed a good response to the combination therapy of 5-FU, leucovorin and cisplatin. A 55-year-old man was admitted with complaints of meteorism due to ascites fluid. Ascitic examination showed a high concentration of CEA and CA19-9, and adenocarcinoma cells. Laboratory and radiological examination did not reveal the origin of the carcinoma, and laparotomy suggested an appendiceal origin. The combination chemotherapy with 5-FU, leucovorin and cisplatin was conducted for a total of 11 courses for 2 years with good QOL until his death. This therapy was suggested to be useful for inoperable carcinomatous peritonitis.

Adenocarcinoma↗

PubMed1996

[NGFI-B/nur77 family involved in T-cell apoptosis].

NGFI-B/nur77 is a member of the steroid receptor superfamily. NGFI-B/nur77 and its related genes constitute a family and the NGFI-B/nur77 family consists of three subtypes, named nur77 alpha, nur77 beta, nur77 gamma. We cloned human nur77 beta cDNA, called TINUR. Although NGFI-B/nur77 is essential for TCR-mediated apoptosis in T-cell hybridomas, the reports on nur77 knock-out mice and nur77 dominant negative transgenic mice suggest that there is a functional redundancy among NGFI-B/nur77 family. NGFI-B/nur77 binds to the response element by monomer or heterodimer with retinoid X receptor (RXR). Assuming that 9-cis-retinoic acid (9-cis-RA) inhibits TCR-mediated apoptosis, nur77 may cause apoptosis by monomer in the absence of 9-cis-RA and may inhibit apoptosis by heterodimer with RXR in the presence of 9-cis-RA.

Animals↗

PubMed1995

Follow-up study in a patient with Setleis syndrome.

We report on an 8-year-old Japanese boy with Setleis syndrome. The patient had a very characteristic "coarse" facial appearance, bitemporal "forceps marks," skin aplasia, sparse hair, and skin hypo- and hyperpigmentation. He also had previously undescribed manifestations, including an aberrant hair pattern of the forehead, linear skin lesions on the forehead, short palpebral fissures, a small skin tag on the right cheek, cone-shaped teeth, and pectus carinatum. Dermatoglyphic studies documented aberrant distal palmar creases (simian crease variant), 8 arches, and reduced total finger ridge count. When serial photographs were reviewed, his facial characteristics became more obvious with increasing age.

Child↗

PubMed1995

cDNA cloning of a NGFI-B/nur77-related transcription factor from an apoptotic human T cell line.

A human T lymphoid cell line, PEER, dies by apoptosis in the presence of PMA and calcium ionophore. A new gene, TINUR, was cloned from apoptotic PEER cells. The expression of the TINUR gene is induced within 1 h after the cross-linking of the T cell Ag receptor complex. TINUR belongs to the NGFI-B/nur77 family of the steroid receptor superfamily and is an orphan receptor. TINUR binds to the same DNA sequence as NGFI-B/nur77. We also propose that the NGFI-B/nur77 family can be classified into two subtypes.

Amino Acid Sequence↗

PubMed1995

Trichostatin A inhibits both ras-induced neurite outgrowth of PC12 cells and morphological transformation of NIH3T3 cells.

During screening for inhibitors of ras-mediated differentiation of PC12 cells, trichostatin A (TSA) was isolated from the metabolites of Streptomyces as a potent inhibitor. TSA blocked both oncogenic ras- and NGF-induced neurite outgrowth from PC12 cells. However, addition of TSA 1 h after NGF-stimulation did not inhibit neuronal differentiation, suggesting that TSA affects an early step in the NGF-signaling pathway mediated by ras. Northern blotting analysis showed that TSA prolonged the maximum expression period of c=fos mRNA triggered by NGF and delayed its return to the basal level. TSA reduced c-jun mRNA induction by NGF but greatly enhanced c-myc mRNA induced by NGF. Yoshida et al. (J. Biol. Chem, 265, 17174-17179, 1990) showed that TSA inhibits histone deacetylation, which might influence the gene expression involved in cellular differentiation. In this study, we also found that TSA prevents histone deacetylation in PC12 cells as well as other cell lines, suggesting that inhibition of histone deacetylation by TSA might affect the expression of early-response genes. We also demonstrated that TSA induced reversion of oncogenic ras-transformed NIH3T3 cells to a normal morphology, suggesting that inhibitors of ras-mediated differentiation of PC12 cells may be effective as anticancer agents.

3T3 Cells↗

PubMed1995

Growth stimulation of ferritin of human leukemia cells in vitro.

Ferritin has been reported to inhibit the growth of some leukemia cells in serum-supplemented culture. Recently we have found that ferritin stimulates the proliferation of human acute myeloblastic leukemia cells HL-60 and erythroleukemia cells K-562-T1 in serum-free medium. In this study, we examined the effect of ferritin against 14 human leukemia cell lines using human heart ferritin in serum-depleted culture medium. Among 14 cell lines tested, 10 were stimulated to proliferate by ferritin (maximum response at 30-300 ng/ml) with 0-1% fetal calf serum (FCS). The growth of all the cell lines was significantly inhibited by ferritin in the presence of 10% FCS. These results suggest that ferritin has dual functions; it promotes the growth of leukemia cells with low concentrations of FCS, but suppresses their growth with high concentrations of FCS.

Cell Division↗

PubMed1995

Effect of zinc on strength and fatigue resistance of amalgam.

OBJECTIVES: This study was conducted to determine the effect of zinc in amalgam on the static mechanical properties and resistance to fatigue-crack propagation of amalgams. METHODS: Fatigue, creep, compressive and flexure tests were performed on high-Cu Dispersalloy (Johnson and Johnson Dental Products Co., East Windsor, NJ, USA) and low-Cu Velvalloy (S.S. White Dental Products Int., Philadelphia, PA, USA) in both Zn-containing and Zn-free formulations. Linear Elastic Fracture Mechanics principles were used to characterize the fatigue behavior (crack lengths were monitored). RESULTS: The incorporation of Zn into these amalgams significantly improved their fatigue and creep resistance, while the effect of Zn on the static compressive and flexure strengths was not consistent. Zn significantly increased (p < 0.05) the resistance to fatigue crack propagation during Stage II crack growth for both amalgams, and increased the variations in crack velocity for a given stress intensity difference, without visibly altering the path or nature of the fatigue cracks. Possible influences on fatigue behavior were the mixed microstructure (particles and matrix), the nature of the crack tip, and creep. SIGNIFICANCE: The superior resistance to tensile fatigue crack propagation of amalgams containing small amounts of Zn (approximately 1 wt%) in vitro compared with amalgams with no Zn correlated with the superior resistance to marginal breakdown in vivo of Zn-containing amalgams. The range of stress intensities over which stable cracks could propagate was small, while the large variations observed in fatigue crack growth rates for individual materials invalidate predicting a unique fatigue life from the empirical equations obtained.

Analysis of Variance↗

PubMed1995

Isolation of a cDNA for a growth factor of vascular endothelial cells from human lung cancer cells: its identity with insulin-like growth factor II.

We have found growth-promoting activity for vascular endothelial cells in the conditioned medium of a human lung cancer cell line, T3M-11. Purification and characterization of the growth-promoting activity have been carried out using ammonium sulfate precipitation and gel-exclusion chromatography. The activity migrated as a single peak just after ribonuclease. It did not bind to a heparin affinity column. These results suggest that the activity is not a heparin-binding growth factor (including fibroblast growth factors) or a vascular endothelial growth factor. To identify the molecule exhibiting the growth-promoting activity, a cDNA encoding the growth factor was isolated through functional expression cloning in COS-1 cells from a cDNA library prepared from T3M-11 cells. The nucleotide sequence encoded by the cDNA proved to be identical with that of insulin-like growth factor II.

Animals↗

PubMed1995

Casting of Ti-6Al-4V alloy compared with pure Ti in an Ar-arc casting machine.

Dental prostheses of Ti are normally cast in pure Ti. Some appliances, however, require higher yield strength. Casting of Ti alloys is of interest in such cases. The objective of the present work was to study the quality of castings made of Ti-6Al-4V compared with those made of pure Ti. Casting was made into a mold kept at room temperature using a MgO-Al2O3 investment. A standardized five-unit bridge was cast, consisting of two cylindrical crowns with sharp margins and three pontics. The overall mold filling was satisfactory. The margins of the casting alloys were, however, more rugged and incomplete than those of pure Ti. The most likely reason for this difference is the increased formation of dendrites in the alloy and thus more resistance to fluid flow. Furthermore, the sprue of the alloy was also found to contain some spherical, internal pores. Such pores were rare in the pure Ti castings. The surface reactions were found to be minimal for both of the materials. Increased casting deficiencies observed in the cast bridges of the Ti-6Al-4V alloy, compared with pure Ti, were: 1) the margins of the crowns in the bridge were less complete and 2) there was a tendency to an increased internal porosity, particularly in the sprues.

Alloys↗

PubMed1995

[A case of toxic shock-like syndrome due to Streptococcus pyogenes].

A case of toxic-shock syndrome due to Streptococcus pyogenes is reported. A 76-year-old female was admitted with complaints of fevers and chills. She had been suffering from cellulitis on her right dorsum pedis for 7 months. Laboratory data on admission showed elevated values of WBC, CRP, and dysfunction of the liver and kidney. She was diagnosed as sepsis due to the cellulitis, and was treated with PIPC and FMOX. However, several hours after admission, her blood pressure decreased and oliguria appeared. Bacteriological examinations from the blood and the cellulitis revealed group A beta-hemolytic Streptococcus which gave streptococcal pyrogenic exotoxin (T-28, SPE.B + C). She died 23 hours after her admission in spite of changing antibiotics to a high-dose of PC-G therapy. This is one of the rare cases of toxic shock-like syndrome due to Streptococcus pyogenes from the cellulitis of the dorsum pedis.

Aged↗

PubMed1995

Mercury vaporization from amalgams with varied alloy compositions.

The fact that mercury is released from dental amalgam restorations after abrasion provides a source of continued controversy over the safe use of this material. Studies have shown that the amount and rate of mercury release vary for different amalgam products. The objective of this study was to determine how alloy composition affects mercury vaporization from experimental amalgams with similar alloy particle size and shape and percent residual mercury. An hypothesis to be tested was that mercury release is dependent upon the concentration of tin in the silver-mercury matrix phase of the amalgam. Seven spherical amalgam alloys (two low-copper and five high-copper) were made by a dental manufacturer (Tokuriki Honten, Japan). Trituration conditions were adjusted so that all set amalgams had the same residual Hg (47.3%). ADA-type amalgam cylinders were aged for 14 days at 37 degrees C, then lightly wet-abraded on #600 silicon carbide, dried, and placed into a tube through which air was blown at a rate of 750 mL/min. Mercury vaporization was monitored with a gold film analyzer (Jerome 411) for 30 min. Total Hg release was determined by integration. We analyzed polished specimens via electron microprobe to determine composition, volume fraction of silver-mercury matrix (gamma 1), and amount of tin in the gamma 1. The results showed a strong negative correlation (r2 = 0.941) between the log of total mercury released and the amount of tin in the gamma 1. The effect of alloy composition, specifically the presence or absence of zinc in the amalgam, could not be definitively determined.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1995

Up-regulation of high-affinity dehydroepiandrosterone binding activity by dehydroepiandrosterone in activated human T lymphocytes.

Although evidence indicates that dehydroepiandrosterone (DHEA) exerts direct physiological effects, its mechanism of action remains unknown. DHEA binding sites were examined using a whole-cell binding assay in a human T lymphoid cell line, PEER, revealing that a single class of high-affinity binding sites for DHEA (dissociation constant = 7.4 +/- 0.53 nmol/L, mean +/- SE, n = 4) was greatly increased when treated with DHEA, phorbol-12-myristate-13-acetate, and the Ca2+ ionophore A23187. Bound [3H]DHEA was displaced sensitively by DHEA and secondarily by dihydrotestosterone, but not effectively by other steroids, including DHEA sulfate. These results not only indicate the existence of a DHEA receptor, but also suggest that T cells become susceptible to regulation by DHEA during the process of signal-induced activation.

Binding Sites↗

PubMed1995

Protective effect of the combined vaccine prepared from cell-free-antigen of Actinobacillus pleuropneumoniae serotypes 1, 2 and 5 in pigs.

Cell-free-antigens prepared from a concentrated culture supernatant of Actinobacillus pleuropneumoniae (A. pleuropneumoniae) serotypes 1, 2 and 5 were mixed and emulsified with oil adjuvant. The combined vaccine of these 3 serotypes of A. pleuropneumoniae was tested for its ability to confer protection. Pigs immunized with the combined vaccine survived and showed no clinical signs against an intratracheal challenge with A. pleuropneumoniae. In contrast, control pigs inoculated with concentrated culture media emulsified with oil adjuvant developed typical symptoms of pleuropneumonia after challenge inoculation.

Actinobacillus Infections↗

PubMed1995

Protective efficacy of cell-free-antigen of Actinobacillus pleuropneumoniae in mice.

Cell-free-antigen (CFA) vaccines of strain Y-1 (serotype 1), G-4 (serotype 2) and E-3 (serotype 5) of Actinobacillus pleuropneumoniae (A. pleuropneumoniae) were prepared by emulsifying concentrated culture supernatant with oil-adjuvant. Mice immunized with the CFA vaccine had a high survival rate (90-100%) against challenge with the homologous strain. They also had cross-protective activity against challenge with the heterogeneous strains but their survival rate was low (20-50%). On the other hand, mice immunized with whole cell vaccine showed serotype specific protection and only a little cross protection. The protective antigens of the CFA were investigated. MAbs were produced by the standard method using spleen cells of mice immunized with CFA. MAbs to Apx I, II, III and capsular antigen of serotype 5 were obtained. Only MAbs to Apx I showed hemolysin neutralization activity among them. The protective effect of these MAbs against A. pleuropneumoniae infection were examined by passive immunization. Administration of Apx I MAb to mice extended survival time after challenge with serotype 5. The mice showed partial cross-protection against challenge with serotype 1. Survival rate was considerably low after the challenge infection. None of the mice given MAbs to Apx II or III were protected against challenge with serotype 5. The mice given MAb to capsular antigen of serotype 5 had a high survival rate (70%) against a challenge with a homologous serotype. Furthermore, mice given MAbs against Apx I and capsular antigen of serotype 5 were completely protected against a challenge with A. pleuropneumoniae serotype 5.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinobacillus Infections↗