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Biomedical subjects

T Takimoto

Publications and source records attributed to T Takimoto.

At least 73 records · Page 4Linked to original sources
PubMed1990

Fibrous histiocytoma of the tongue base.

Fibrous histiocytomas usually occur in the dermis and superficial subcutis. Involvement of the tongue is extremely rare. A 51-year-old female, referred to us for a sore throat, was noted on intraoral examination to have a polypoid mass with a smooth mucosal surface on the base of the tongue. This lesion was excised because of its probable continuing growth. This tumor, which showed staining for alpha 1-antichymotrypsin, was pathohistologically diagnosed as fibrous histiocytoma. This was the second documented case of fibrous histiocytoma of the tongue.

Female↗
PubMed1990

Fourth branchial pouch anomaly.

We present an extremely rare case of fourth branchial fistula in a 23-year-old male. The characteristic clinical feature was a recurrent left lower neck abscess which did not respond to appropriate medical and surgical therapy. Radiography and a computed tomographic scan with contrast material revealed a fistula running from the apex of the left pyriform sinus (internal opening) to the left lower neck abscess. The fistula tract was excised surgically. Histological examination of the excised fistula revealed a squamous epithelial lining and subepithelial lymphoid tissue. This pyriform sinus fistula is thought to be of fourth pharyngeal pouch origin, because of its surgical aspects and the histological findings of the excised fistula.

Abscess↗
PubMed1990

Concatameric replication of Epstein-Barr virus: structure of the termini in virus-producer and newly transformed cell lines.

The linear form of Epstein-Barr virus (EBV) DNA has homologous direct tandem repeats of approximately 500 bp at each terminus (TR). After infection, EBV DNA circularizes via the TR to form the intracellular episomal DNA. To analyze the mechanism of the synthesis of linear DNA through possible replicative intermediates, the terminal fragments were identified in the total intracellular DNA and the covalently closed circular DNA from a productively infected cell line after induction of replication or after treatment with an inhibitor of viral DNA synthesis. These studies indicate that some of the fused terminal fragments detected in the total intracellular DNA are replication-dependent forms which are selectively excluded from the covalently closed circular fraction and are eliminated after treatment with acyclovir. The EBV terminal restriction enzyme fragments were identified in three producer cell lines, each with a characteristic number of TR in the intracellular episomal DNA. Identification of the termini in cell lines established with the three virus strains revealed that the newly transformed cell lines had a greater number of TR than did the template DNA in the producer cell line. The increase in the number of TR in progeny episomes indicates that linear DNA is produced from concatameric replicative intermediates rather than from amplified catenated circular intermediates.

Cell Line↗
PubMed1990

Interactions between Epstein-Barr virus (EBV) and human cell lines: growth and EBV induction.

Differences in in vitro growth characteristics between Epstein-Barr virus (EBV) genome-negative and genome-positive lymphoblastoid cell lines and between EBV genome-negative and genome-positive epithelial cell lines were investigated. All EBV genome-positive cells were able to grow in medium containing only 0.75% fetal calf serum (FCS), whereas no EBV genome-negative cells were able to grow at this low concentration. However, there was no clear difference between the growth of the two EBV genome-negative lymphoblastoid cell lines (BJAB and Ramos) and two EBV genome-positive BJAB and Ramos sublines (BJAB/B95-8 and Ramos/B95-8) in medium containing more than 2.5% FCS. On the other hand, an EBV genome-positive clone of A2L/AH epithelial hybrid cells (cl-1) grew in both concentrations of FCS better than an EBV genome-negative clone of A2L/AH cells (cl-654). In addition, there was a difference in EBV induction between EBV genome-positive lymphoblastoid (BJAB/B95-8 and Ramos/B95-8) and epithelial (cl-1) cells after treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA). Treatment of BJAB/B95-8 and Ramos/B95-8 cells with TPA induced a low percentage of EBV-induced early antigen but not viral capsid antigen, whereas treatment of cl-1 cells with TPA induced both early antigen and viral capsid antigen.

Cell Line↗
PubMed1990

Epstein-Barr virus (EBV) receptors on epithelial hybrid cells derived from nasopharyngeal carcinoma.

We previously established an Epstein-Barr virus (EBV) genome-positive epithelial hybrid cell line, designated NPC-KT, which was prepared by fusing primary epithelial cells derived from nasopharyngeal carcinoma (NPC) with an epithelial Ad-AH cell line. In this study, we measured the presence of the EBV receptors using radiolabelled EBV. It was determined that similar amounts of Burkitt's lymphoma (BL)-derived P3HR-1 or NPC-KT-derived EBV can attach BL-derived Raji cells, but that only P3HR-1 virus can attach to NPC-KT cells. In addition, the superinfection of NPC-KT cells with P3HR-1 virus could not be inhibited by pretreatment with a monoclonal antibody against C3d (OKB7). Raji cells adsorbed with OKB7 became much less susceptible to superinfection with P3HR-1 or NPC virus. The data suggest that EBV receptors unrelated to C3d receptor exist.

Cell Line↗
PubMed1990

Plunging ranula localized in the parapharyngeal space.

Plunging ranulas are a mucous extravasation and usually originate from the sublingual gland. They dissect between the facial planes and muscle of the base of the tongue to the submandibular triangle. We report here a rare case of plunging ranula localized in the parapharyngeal space. The relevant anatomy is reviewed and discussed.

Humans↗
PubMed1990

Branchial cleft fistula with heterotopic salivary gland tissue in the lower neck.

A rare case of second branchial fistula with heterotopic salivary gland tissue in the lower neck is described. The patient was a 12-year-old girl with a fistula which appeared to be clinically a second branchial cleft anomaly. It was removed from her neck. Histological examination revealed that the lesion was a branchial cleft fistula with elements of salivary gland tissue.

Branchioma↗
PubMed1990

Osseous hemangioma arising in the facial bone.

Hemangiomas of bone are rare tumors in the facial region. In our own case, magnetic resonance imaging showed unique linear high-signal-intensity internal components in T1-weighted images. The histological study demonstrated that adipose tissue occurring in the stroma of the tumor caused the high signal intensity in T1-weighted images. We employed a vascularized calvarial bone flap to reconstruct the malar eminence after resection of the tumor.

Aged↗
PubMed1990

[Dissolution of silver and copper from Ag-Cu binary alloys under dynamic conditions].

Ag-Cu binary alloys containing 5-30% copper were subjected to dynamic extraction at 200 rpm and 37 degrees C to simulate the functional movement in the oral environment. Extraction was carried out in Eagle's minimum essential medium every two weeks for 18 weeks. The corrosion products were examined by the separation of extracts with a 0.22 micron filter. Significant dissolution of copper occurred with increasing copper content, but the increase in silver dissolution was slight. The amount of copper in the filtrate was the same as that in the extract, but no silver was detected in the filtrate. Therefore, dynamic extraction accelerated the dissolution of copper from the Ag-Cu binary alloys and thus lowered the corrosion resistance.

Copper↗
PubMed1990

[Corrosion behavior of Ag-Pd binary alloys under dynamic conditions and its cytotoxicity (in vitro)].

Ag-Pd binary alloys with various palladium contents were extracted in Eagle's minimum essential medium by dynamic extraction at 200 rpm at 37 degrees C. The extracts were filtered through a 0.22 microns cellulose acetate filter, and the silver and palladium amount of the extracts and filtrates as dissolved metallic elements was measured with atomic absorption spectroscopy. Extracts and filtrates were also used in cultivation of L-929 cells to study in vitro cytotoxicity. An increase in the palladium content of the alloy resulted in decreased silver dissolution and increased palladium dissolution. The amount of palladium in the filtrates increased as the extraction period was extended, but the amount of silver was negligible in all filtrates. Extracts which had been extracted for 1 day showed strong cytotoxicity in pure Ag. However, the addition of palladium at a weight percent of more than 40% decreased cytotoxicity almost to the control level. Filtrate which had been extracted for 1 or 3 days was noncytotoxic in all alloys. However, the filtrate which had been extracted for 5 or 7 days showed cytotoxicity, which was especially strong in high-palladium alloys. These results demonstrate that extraction using a dynamic method appears to be useful in the investigation of their corrosion and biocompatibility.

Biocompatible Materials↗
PubMed1989

Cell cycle related change of Ara-C transport in HL-60 cells after differentiation induction.

Using a promyelocytic leukemia cell line, HL-60, we studied the membrane transport of Ara-C before and after differentiation induced by retinoic acid (RA). In RA-treated cells, Ara-C transport was reduced and there was a concomitant increase of the ID50 values of Ara-C in comparison with the controls. By three different procedures to synchronize untreated cells, i.e. density arrest G1 phase enrichment, aphidicolin-induced S phase accumulation and the double isoleucine block method, we found that Ara-C transport was 30-50% higher in the S phase than in the G1 phase. Therefore, the observed decrease in Ara-C transport is, in part, due to the retarded growth accompanied by an accumulation of cells in the G1 phase after differentiation induction.

Aphidicolin↗
PubMed1989

Induction of histidine decarboxylase in rat basophilic leukemia cells by interferon and prevention of its effect in coincubation with ADP-ribosyltransferase inhibitors.

Treatment of rat basophilic leukemia cell line (2H3) with interferon-alpha significantly increased intracellular histamine levels. On the other hand, the histidine content was decreased reciprocally by interferon in a dose-dependent manner. Concomitantly, the activity of histidine decarboxylase, the enzyme responsible for histamine synthesis, was augmented. The increase in histidine decarboxylase activity was partially abolished in co-incubation with inhibitors of ADP-ribosyltransferase, such as 3-aminobenzamide or nicotinamide. These results suggest the pivotal role of activation of histidine decarboxylase, presumably through ADP-ribosylation of the enzyme, in interferon-induced histamine synthesis.

Animals↗