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Biomedical subjects

T Takimoto

Publications and source records attributed to T Takimoto.

At least 91 records · Page 5Linked to original sources
PubMed1989

VP-16-induced nucleotide pool changes and poly(ADP-ribose) synthesis: the role of VP-16 in interphase death.

Exposure of human promyelocytic leukemia cell line (HL-60) to VP-16 resulted in accumulation of DNA strand breaks. Concomitantly, intracellular NAD levels fell at 1 h, followed by declines in ATP at 2 h and in GTP, CTP, and UTP at 3 h. Furthermore, marked morphological changes, such as loss of microvilli or bleb formation, appeared at 4 h and cell death by 8-10 h. The addition of an inhibitor of poly(ADP-ribose) polymerase, 3-aminobenzamide (5 mM), theophylline (2 mM), or thymidine (1 mM), prevented these sequential reductions of nucleotide pools and cell death. In fact, the activation of poly(ADP-ribose) synthesis was detectable within a few hours after treatment with VP-16, although it was smaller than that induced by N-methyl-N'-nitro-N-nitrosoguanidine. These results may suggest the possible role of activation of poly(ADP-ribosyl)ation in VP-16-induced nucleotide pool changes and subsequent interphase death.

Benzamides↗
PubMed1989

Synergistic effect of methotrexate and 1-beta-D-arabinofuranosylcytosine on the generation of DNA strand breaks in a human promyelocytic leukemia cell line.

We investigated the accumulation of DNA strand breaks in a human promyelocytic leukemia cell line, HL-60, treated with methotrexate (MTX) and 1-beta-D-arabinofuranosylcytosine (Ara-C). The sequential treatment with MTX then Ara-C had a synergistic effect on the formation of DNA strand breaks, which was dependent on MTX and Ara-C concentrations. On the other hand, when Ara-C preceded MTX, no such synergism was observed. The addition of both thymidine and hypoxanthine to this system, but not thymidine or hypoxanthine alone, abolished the synergism. Pretreatment with MTX augmented the generation of 1-beta-D-arabinofuranosylcytosine 5'-triphosphate. However, this augmentation did not necessarily correlate with the amount of strand breaks. Whatever the underlying mechanism of this synergism is, our present data provide one possible biochemical basis for sequential MTX and Ara-C therapy.

Aphidicolin↗
PubMed1989

Hamartoma of the tongue.

Hamartomas of the tongue are rare. A case of a 6-year-old girl with hamartoma at the base of the tongue is reported. The diagnosis was confirmed by a histopathologic examination of the mass after removal in a wedge fashion by the CO2 laser under general anesthesia. The literature is reviewed and discussed.

Child↗
PubMed1989

Parapharyngeal schwannoma of the cervical sympathetic chain in a child.

Parapharyngeal schwannomas of the cervical sympathetic chain are benign tumors that have not been reported in children, compared to parapharyngeal neuroblastomas. We present, to our knowledge, the youngest reported case of parapharyngeal schwannoma of the cervical sympathetic chain. The nerve of origin could be clearly ascertained when excision was made through a cervical approach.

Child, Preschool↗
PubMed1989

Ranula and sarcoid granuloma of a sublingual gland.

A case is reported in which the treatment of the ranula consisted of dissection of the cystic wall along with excision of the sublingual gland of origin. The histological picture of the gland was consistent with sarcoidosis. Thereafter, all other examinations were negative for sarcoidosis. However, there remains the possibility that the lesion may be the precursor of widespread sarcoidosis which might occur in the future.

Adult↗
PubMed1989

First branchial cleft anomaly: a report of case.

A rare case of first branchial cleft anomaly in a 21-year-old female is described. A fistulous tract was located near the angle of the mandible and anterior to the sternocleidmastoid muscle, extending upwards under the facial nerve and opening into the external auditory canal. The tract was completely removed and the facial nerve was preserved. Histopathologic examination revealed that the tract was composed of keratinizing squamous cell epithelium with adnexal structures and cartilage.

Adult↗
PubMed1989

Reevaluation of treatment of ranula.

Ranulas or mucoceles of the floor of the mouth are cysts arising from the sublingual glands. Experience with 27 such patients over the past 10 years is reviewed. Successful treatment was achieved by excision of the cyst with the sublingual gland.

Adolescent↗
PubMed1989

The human nasopharynx as a reservoir for Epstein-Barr virus.

Nineteen human nasopharyngeal tissue specimens biopsied from patients with suspected nasopharyngeal carcinoma (NPC) and 15 adenoid tissue specimens obtained by surgery were successfully grown in culture without bacterial and fungal contamination. Fibroblastic growth developed in all of the cultures. In some cases, epithelial growth was also seen among the fibroblastic growth. The cells became round and floated in the culture fluid between 19th and 57th day of culture in 6 out of 10 NPC tissue cultures, 3 out of 9 tissue cultures of apparently normal nasopharyngeal mucosa of patients referred for exclusion of NPC, and 4 out of 15 adenoid tissue cultures. The floating cells consisted of B-lymphoblastoid cells and were positive Epstein-Barr virus (EBV)-associated nuclear antigen (EBNA). The data suggest that a small number of B-lymphocytes in the human nasopharynx serve as a reservoir for EBV.

Adenoids↗
PubMed1989

Intravagal parathyroid adenoma.

An extremely rare case of intravagal parathyroid adenoma is presented. The tumour caused fusiform swelling of the left vagus nerve was shelled out. Post-operatively the left recurrent nerve palsy was recovered in the two months. Serum calcium level returned to normal on the tenth day after the surgical operation without symptoms of hypocalcaemia.

Adenoma↗
PubMed1989

Agenesis of the cervical internal carotid artery.

Total or segmental agenesis of the internal carotid artery is a rare anomaly. The cervical portion of the internal carotid artery was absent in the right side of the patient who was carried out radical surgery due to recurrent oropharyngeal cancer. Post-operative venous digital subtraction angiography revealed that the remaining intracranial portion of the internal carotid artery was normally patent and supplied blood flow via ipsilateral external carotid artery. Otolaryngologist-Head and Neck surgeon should know such a vascular anomaly and avoid a disastrous result on dividing the external carotid artery.

Carotid Artery, Internal↗
PubMed1989

Pharyngeal cyst arising from second branchial cleft.

A rare case of pharyngeal cyst arising from the second branchial cleft in a 14-year-old boy is described. A cyst located in the right posterolateral wall of the oropharynx was completely removed by an intraoral approach. Histopathological examination revealed that the cyst was lined with columnar (respiratory type) epithelium.

Adolescent↗
PubMed1989

Epstein-Barr virus with transforming and early antigen-inducing ability originating from nasopharyngeal carcinoma: mapping of the viral genome.

Epstein-Barr virus (EBV) from a human hybrid epithelial cell line (NPC-KT), derived from the fusion of human adenoidal cells and EBV genome-containing primary nasopharyngeal carcinoma cells (NPC) has both transforming and early antigen (EA)-inducing abilities. EBV DNA from NPC-KT cells was partially digested with TaqI and ligated to the cloning vector pJB8 at the ClaI site. This cosmid library encompassed the whole genomic DNA of the virus except for several kb of the terminal fragments. The identification and location of each of the cloned DNA fragments have been defined by hybridization to blots prepared with B95-8 and NPC-KT virion DNA. Defective heterogeneous restriction enzyme fragments of the viral DNA were not identified in any of the cosmid clones nor detected in hybridizations to virion DNA, which indicates that a single virus population derived from the NPC tissue has both transforming and EA-inducing activities.

Antigens, Viral↗
PubMed1989

Fibrin glue in the surgical treatment of ranulas.

The essential treatment of a ranula is meticulous dissection of the thin wall of the cyst in continuity with the sublingual gland of origin. We have used a technique of fibrin glue injection into the cystic space of the ranula after it had been evacuated by aspiration. The fibrin glue within the cystic cavity prevents collapse of the wall of the cyst during surgery and facilitates and simplifies the surgical procedure by clearly outlining the involved area and by sharply delineating its thin wall.

Fibrin Tissue Adhesive↗
PubMed1989

Cytopathic effects induced by Epstein-Barr virus replication in epithelial nasopharyngeal carcinoma hybrid cells.

NPC-KT cl.S61, a subclone derived from an epithelial-nasopharyngeal carcinoma hybrid cell line (NPC-KT), showed cytopathic changes characteristic of herpesvirus replication, including formation of multinucleated giant cells and inclusion bodies, when Epstein-Barr virus replicative cycle was induced by 5-iodo-2'-deoxyuridine. Acyclovir (an inhibitor of herpesvirus DNA polymerase), Epstein-Barr virus-immune human serum, or 2-deoxyglucose (an inhibitor of the glycosylation) interfered with syncytium formation, indicating that a virus-specified glycoprotein belonging to the late group is responsible for cell fusion induced by Epstein-Barr virus replication in cl.S61 cells.

Acyclovir↗
PubMed1989

Gene mapping of an Epstein-Barr virus isolate obtained from a nasopharyngeal carcinoma.

Gene mapping of an Epstein-Barr virus (EBV) isolate derived from a nasopharyngeal carcinoma (NPC), designated NPC-EBV, has been performed. This isolate was rescued from an NPC epithelial hybrid cell line (NPC-KT), and used to transform cotton-top tamarin lymphocytes which, along with the epithelial NPC-KT cells, were used in the mapping studies. Using the BamHI and EcoRI restriction enzymes, we found that the NPC-EBV isolate did not contain the deletions observed in the genomes of the prototype HR-1 and B95-8 isolates, and may represent a 'more complete' virus genome. Polymorphism was observed in the BamHI-X, T, H, and L regions as compared to the HR-1 and B95-8 isolates. The NPC-EBV DNA in the epithelial NPC-KT cells was compared to the NPC-EBV genome in three different cotton-top tamarin lymphoblastoid cell lines transformed with the isolate. The restriction patterns were the same with one exception; there were differences in the size of the BamHI N-J het regions. This finding is consistent with the idea that the BamHI N-J het region may be the switch point of EBV DNA from the linear to the episomal form. The NPC-EBV is the first NPC-derived isolate to be obtained from epithelial cells in vivo and maintained in epithelial cells in vitro, and will be useful for studying biological variability of EBV.

Blotting, Southern↗
PubMed1989

Spontaneous lymphoblastoid transformation of cells obtained from human tonsils.

Spontaneous lymphoblastoid transformation of cells obtained from 25 human tonsils were investigated. Three Epstein-Barr virus (EBV) genome-positive lymphoblastoid cell lines were spontaneously established in tissue cultures in vitro from human tonsils. In addition, the frequency of spontaneous lymphoblastoid transformation was increased by the treatment of tumor promoter, 12-0-tetradecanoylphorbol-13-acetate and 18 lymphoblastoid cell lines were established. The data suggest that the human tonsil is a reservoir for EBV.

Adolescent↗
PubMed1989

Characteristics of Epstein-Barr virus-carrying lymphoblastoid cells derived from human tonsil: EBV production and autoantibody response.

Tonsillar and peripheral blood lymphocytes from 20 patients with tonsillitis were examined for production of Epstein-Barr virus (EBV) and antinuclear antibodies within 2 weeks after EBV transformation. All established lymphoblastoid cell lines (LCLs) contained more than 90% EBV nuclear antigen-positive cells. However, no LCLs produced biologically active virus. On the other hand, 10 (50%) out of 20 tonsillar LCLs and 4 (20%) out of 20 peripheral blood LCLs produced autoantibodies. These results showed that there are differences in an EBV-induced lymphocyte autoantibody response between tonsillar lymphocytes and peripheral blood lymphocytes.

Antibodies, Antinuclear↗