Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 19 recordsLinked to original sources

PubMed1992

C33 antigen recognized by monoclonal antibodies inhibitory to human T cell leukemia virus type 1-induced syncytium formation is a member of a new family of transmembrane proteins including CD9, CD37, CD53, and CD63.

C33 Ag was originally identified by mAb inhibitory to syncytium formation induced by human T cell leukemia virus type 1. The Ag was shown to be a highly heterogeneous glycoprotein consisting of a 28-kDa protein and N-linked oligosaccharides ranging from 10 to 50 kDa. In the present study, cDNA clones were isolated from a human T cell cDNA expression library in Escherichia coli by using mAb C33. The identity of cDNA was verified by immunostaining and immunoprecipitation of transfected NIH3T3 cells with mAb. The cDNA contained an open reading frame of a 267-amino acid sequence which was a type III integral membrane protein of 29.6 kDa with four putative transmembrane domains and three putative N-glycosylation sites. The C33 gene was found to belong to a newly defined family of genes for membrane proteins, such as CD9, CD37, CD53, CD63, and TAPA-1, and was identical to R2, a cDNA recently isolated because of its strong up-regulation after T cell activation. Availability of mAb for C33 Ag enabled us to define its distribution in human leukocytes. C33 Ag was expressed in CD4+ T cells, CD19+ B cells, CD14+ monocytes, and CD16+ granulocytes. Its expression was low in CD8+ T cells and mostly negative in CD16+ NK cells. PHA stimulation enhanced the expression of C33 Ag in CD4+ T cells by about 5-fold and in CD8+ T cells by about 20-fold. PHA stimulation also induced the dramatic size changes in the N-linked sugars previously shown to accompany human T cell leukemia virus type 1-induced transformation of CD4+ T cells.

Amino Acid Sequence↗

PubMed1992

Strong induction of ICAM-1 in human T cells transformed by human T-cell-leukemia virus type 1 and depression of ICAM-1 or LFA-1 in adult T-cell-leukemia-derived cell lines.

Sixteen human T-cell lines were studied for the expression of a cell-adhesion molecule ICAM-1 and its counter-receptor LFA-1. The cell lines included 3 human T-cell-leukemia-virus-type-I (HTLV-1)-negative cell lines derived from acute lymphoblastic leukemia (ALL) and 13 HTLV-1-positive cell lines, 7 of them established from cord- or peripheral-blood T cells by in vitro transformation with HTLV-1, 2 derived from HTLV-1 carriers, and 4 derived from patients with adult T-cell leukemia (ATL). In sharp contrast to a basal level of ICAM-1 in 3 HTLV-1-negative ALL cell lines, strong induction of ICAM-1 was seen in all HTLV-1-positive T-cell lines except for MT-1, one of the 4 ATL cell lines used in the present study. On the other hand, the expression of LFA-1 (CD11a and CD18) was more or less similar among the cell lines with and without HTLV-1. Interestingly, however, 3 out of 4 ATL cell lines (TL-Om1, H582, HUT102) revealed striking depression of LFA-1 expression. Several lines of evidence strongly argued against direct involvement of the viral transactivator p40tax or some autocrine cytokines in the induction of ICAM-1 in HTLV-1-positive T-cell lines. It was also found that ICAM-1 and LFA-1 were involved in syncytium formation induced in the co-culture of HTLV-1-positive and HTLV-1-negative human T-cell lines. Implications of constitutive expression of ICAM-1 for certain clinical manifestations of ATL and of depression of either ICAM-1 or LFA-1 during progression of ATL are discussed.

Animals↗

PubMed1992

Hinge region of human IgG2 protein: conformational studies with monoclonal antibodies.

We previously produced three anti-human IgG2 mAbs with high specificity and found that they recognize distinct epitopes in the hinge region and neighboring residues in human IgG2: HG2-6A was reactive with the hinge region (Glu216-Pro230); HG2-56F with the Pro234 residue and HG2-30F with the Val235 residue. In this study, we evaluated the reactivities of those three mAbs with human IgG2 protein under various conditions. The results obtained using HG2-6A mAb indicated that the hinge region was concealed in the native form, but exposed after heat treatment at 63 degrees C, or chemical treatment with 3 M KSCN, 3 M guanidine, 30% CH3CN, 8 M urea or acid at pH 2.0 as well as by adsorption onto polystyrene beads. The IgG2 hinge region was also exposed after binding to specific antigens. The Pro234 residue recognized by HG2-56F mAb was exposed under all conditions studied. The neighboring Val235 residue recognized by HG2-30F, however, was completely concealed in the native and antigen-bound states. Only treatment with 3 M guanidine and acid at pH 2.0, or physical adsorption induced conformational changes to partially expose the Val235 residue.

Antibodies, Monoclonal↗

PubMed1992

Involvement of neuronal cell surface molecule B2 in the formation of retinal plexiform layers.

The B2 molecule is a 220 kd neuronal cell surface protein of Xenopus, recognized by monoclonal antibody B2 (MAb B2). Immunohistochemistry using MAb B2 revealed that the B2 molecule was expressed in both the inner and outer plexiform layers within the neural retina. During development of the neural retina, the B2 molecule first appeared at stages 35/36 in the newly formed plexiform layers. When embryonic eyes were cultured in the presence of anti-B2 antiserum (Fab fragments), the formation of the retinal plexiform layers was impeded. These data suggest that the cell surface molecule B2 plays a role in the development of retinal plexiform layers.

Animals↗

PubMed1992

Human T cell leukaemia virus type 1 p21X mRNA: constitutive expression in peripheral blood mononuclear cells of patients with adult T cell leukaemia.

Although the p21X protein of human T cell leukaemia virus type 1 (HTLV-1) is generally thought to be expressed from a doubly spliced mRNA transcript (tax/rex mRNA) that encodes the p40tax, p27rex and p21X proteins, we have shown previously that a novel, alternatively spliced mRNA transcript (p21X mRNA) is responsible for p21X production in HTLV-1-infected cell lines. In the present study, we analysed expression of p21X mRNA and tax/rex mRNA in uncultured and cultured peripheral blood mononuclear cells (PBMCs) from eight patients with adult T cell leukaemia by using a quantitative polymerase chain reaction coupled to reverse transcription. The results demonstrated that the expression of p21X mRNA occurs constitutively in all uncultured and cultured PBMCs, whereas the expression of tax/rex mRNA is inducible in the cultured PBMCs, as described previously. In uncultured and cultured PBMCs from the one specimen in which p21X mRNA was highly expressed, the p21X protein was detectable by Western blotting. On the other hand, p27rex protein was detectable only after cultivation. These findings indicate that p21X mRNA is constitutively expressed in vivo and is responsible for production of p21X protein.

Adult↗

PubMed1992

An autopsy case of invasive pituitary adenoma (prolactinoma) with rapid fatal clinical course due to streptococcal meningitis.

A 44-year-old male suffered epistaxis and headache of sudden onset and was diagnosed as having suppurative meningitis due to streptococci. Four days after the onset of symptoms, he died despite treatment with antibiotics. Destruction and ballooning of the sella turcica was revealed by a plain head X-ray examination during the clinical course. At autopsy, a massive tumorous lesion extended from the ballooned sella turcica to the paranasal cavities, nasopharynx and facial bone, and this had resulted in suppurative meningitis. The tumor was also disseminated to the basal skull. The tumor cells possessed prominent nuclear atypia and were immunohistochemically positive for prolactin. This was diagnosed as a case of pituitary adenoma with markedly invasive pathological findings and a rapid and fatal clinical course.

Adenoma↗

PubMed1992

Identification of membrane antigen C33 recognized by monoclonal antibodies inhibitory to human T-cell leukemia virus type 1 (HTLV-1)-induced syncytium formation: altered glycosylation of C33 antigen in HTLV-1-positive T cells.

We isolated four monoclonal antibodies (MAbs), M38, M101, M104, and C33, which were capable of inhibiting syncytium formation induced in a human T-cell line, MOLT-4-#8, by coculture with human T-cell leukemia virus type 1 (HTLV-1)-positive human T-cell lines. The MAbs had, however, no inhibitory activity on syncytium formation induced in a human osteosarcoma line, HOS, by HTLV-1-positive T-cell lines. They also did not inhibit syncytium formation induced in MOLT-4-#8 by human immunodeficiency virus type 1-positive MOLT-4. All MAbs reacted with various human cell lines of lymphoid and nonlymphoid origins, including HTLV-1-positive T-cell lines. Furthermore, they all reacted with a murine A9 clone containing human chromosome 11 fragment q23-pter. Two MAbs, M104 and C33, immunoprecipitated a membrane antigen with the same molecular size. The antigen (henceforth called C33 antigen) was about 40 to 55 kDa in HTLV-1-negative Jurkat, CEM, MOLT-4, and normal peripheral blood CD4-positive human T cells and about 40 to 75 kDa in HTLV-1-positive C91/PL, TCL-Kan, MT-2, and in fresh HTLV-1-transformed CD4-positive human T-cell lines. Pulse-chase experiments revealed that C33 antigen was synthesized as a 35-kDa precursor that was then processed to 41 to 50 kDa in MOLT-4 and to 44 to 70 kDa in C91/PL. In the presence of tunicamycin, a 28-kDa protein was synthesized. The conversion from 35 kDa to 41 to 50 kDa in MOLT-4 and to 44 to 70 kDa in C91/PL was inhibited by monensin. Treatment with N-glycanase alone, but not with sialidase and O-glycanase in combination, completely removed the sugar moiety of C33 antigen from both HTLV-1-negative Jurkat and HTLV-1-positive C91/PL. Therefore, C33 antigen has only N-linked carbohydrates, the modification of which appears to be substantially altered in the presence of the HTLV-1 genome.

Antibodies, Monoclonal↗

PubMed1992

Deposition of loosely bound and firmly bound fluorides on tooth enamel by an acidic gel containing fluorosilicate and monocalcium phosphate monohydrate.

The amounts of loosely bound fluoride (F) deposited on human enamel by 4-min and 2-hour treatments with either acidulated phosphate fluoride (APF) or a monocalcium phosphate monohydrate and sodium hexafluorosilicate (MCPM-SHFS)-containing gel were measured with the use of a constant-composition F washing method. Enamel biopsies conducted before treatment and after washing were used to determine the firmly bound F uptake. The results showed that the MCPM-SHFS treatments produced significantly more loosely bound F than did the APF treatments. The 4-min treatment with either APF or MCPM-SHFS did not produce significant firmly bound F deposition, but the 2-hour treatments did, with that produced by MCPM-SHFS being significantly greater. The MCPM-SHFS gel, which had the same F content as APF and which may be applied to the proximal tooth surfaces in vivo without the use of a tray, has the potential to be more efficacious than APF because it deposits greater amounts of both loosely bound and firmly bound F.

Acidulated Phosphate Fluoride↗

PubMed1992

Effect of a two-solution fluoride mouthrinse on remineralization of enamel lesions in vitro.

A previous study showed that a two-solution fluoride (F) rinse deposited significantly more loosely-bound F on the tooth surface than did a sodium fluoride (NaF) rinse with the same F concentration (12 mmol/L). In the present study, this experimental rinse was evaluated for its ability to cause remineralization of enamel lesions in an in vitro pH-cycling model. Caries-like lesions were formed in the enamel of extracted human molars by means of a pH 4 demineralizing solution. Fifty-one approximately 120-microns-thick sections containing lesions were randomly divided into (1) control, (2) NaF rinse, and (3) two-solution F rinse groups. With the cut surfaces protected, the control samples were immersed in a pH 7 remineralizing solution for 12 days, and twice daily the sections were also exposed to a pH 4 demineralizing solution for 30 min. Samples in the NaF group received an additional one-minute rinse with a NaF (12 mmol/L) solution twice daily. Samples in the two-solution rinse group received the rinse treatment with a 12 mmol/L F solution prepared by combination of a Na2SiF6 and phosphate-containing solution with a calcium solution just before use. The mineral contents of the lesions were assessed by quantitative microradiography. The results showed that (1) no significant de- or remineralization was detected in the controls; (2) a 46% decrease in mineral loss (delta Z) of the lesion was produced by the NaF rinses; and (3) a 94% decrease in delta Z and a 20-microns-thick, mineral-dense surface-coating were produced by the two-solution F rinse treatment.

Apatites↗

PubMed1992

In vivo fluoride concentrations measured for two hours after a NaF or a novel two-solution rinse.

The concentrations of fluoride in various samples from the oral environment were measured at timed intervals after a novel rinse or a NaF rinse, both containing a total of 12 mmol/L (228 ppm) fluoride. The novel rinse consisted of two solutions mixed just before application: Part A contained calcium chloride and sodium acetate; part B contained a hydrolyzable source of fluoride (sodium hexafluorosilicate) and sodium phosphate. Samples were obtained as follows: Single-site plaque-fluid samples were obtained by centrifugation of first-molar plaque; pooled whole-plaque samples were collected from second molars; centrifuged, pooled whole-saliva was collected by vacuum. All samples were analyzed by micro-analytical methods. Results showed that, compared with NaF, the two-solution rinse produced significantly higher salivary fluoride concentrations, plaque-fluid fluoride concentrations, and acid-extractable fluoride in the whole plaque by factors of about 4, 2, and 6, respectively, at 120 min. The results of this study suggest that the new rinse may provide a greater cariostatic effect at the same fluoride dosage than does a NaF rinse.

Adult↗

PubMed1992

Structures of N-linked oligosaccharides of microsomal glycoproteins from developing castor bean endosperms.

The structures of sugar chains of the glycoproteins from the microsomal fraction of developing castor bean endosperms have been analyzed. The structural analyses were done by a fluorescence method combined with component analysis, exoglycosidase digestions, partial acetolysis, Smith degradation, and 1H-NMR spectroscopy. The estimated structures fell into three categories; the first was oligomannose-type, the second xylomannose-type, the third complex-type. Among these oligosaccharides, Man3Fuc1Xyl1GlcNAc2 (M3FX) and Man6GlcNAc2 (M6B) were the major structures. The structures of Man4GlcNAc2 (M4C) and Man4Xyl1GlcNAc2 (M4X) have also been found in the microsomal glycoproteins of the developing bean endosperms. These results could indicate that the structures of M4C, M4X, and M3FX are formed in the stage of sugar chain processing in the microsomal fraction, in which oligomannose-type sugar chains are modified into complex-type ones by several kinds of processing enzymes.

Carbohydrate Sequence↗

PubMed1992

Glycinin A4A5 subunit digesting protease in soybean seeds.

Endopeptidase was partially purified from the globulin fraction of 4-hr-imbibed soybean seeds. The protease fraction obtained had proteolytic activity on the glycinin A4A5 subunit at both pH 4 and 8. A suitable peptidic substrate for the endopeptidase was isolated from the tryptic digest of the carboxymethylated A4A5 subunit. Using the tryptic peptide of glycinin A5 subunit, a simple assay system for the soybean endopeptidase activity has been established. The activity was significantly inhibited by phenylmethylsulfonyl fluoride, indicating the endopeptidase is a serine protease.

Amino Acid Sequence↗

PubMed1992

Acute toxicity of tri-n-butyltin chloride (TBTC) in the Syrian golden hamster.

The effects of tri-n-butyltin chloride (TBTC) on Syrian golden hamsters were studied. TBTC in single doses of 0, 29.6, 44.4, 66.7, 100 or 150 mg/kg were given to 10 male hamsters in each group and the mortality rates were determined two weeks thereafter. They were 0% (0/10), 0% (0/10), 10% (1/10), 10% (1/10), 30% (3/10) and 70% (7/10) for 0, 29.6, 44.4, 66.7, 100 and 150 mg/kg groups, respectively. In the case of females, seven groups consisting of 10 animals each were given TBTC at doses of 0, 29.6, 44.4, 66.7, 100, 150, or 225 mg/kg. The mortality rates determined two weeks after the TBTC treatment were 0% (0/10), 10% (1/10), 10% (1/10), 0% (0/10), 40% (4/10), 30% (3/10) and 90% (9/10) for 0, 29.6, 44.4, 66.7, 100, and 225 mg/kg groups, respectively. Based on these mortality data, the LD50s via oral administration were determined as 146.9 mg/kg (95% C.I. 111.8-193.3 mg/kg) for the male and 172 mg/kg (95% C.I. 127.2-233.4 mg/kg) for the female. Regarding pathological changes, animals experienced lesions in the bile duct, such as the dilatation of the common bile duct and cholestasis, and/or adhesion of the bile duct to the liver, gallbladder, pancreas and duodenum. In a separate experiment, a single dose of 44.4 mg/kg TBTC was administered orally to 12 male hamsters, then the concentrations of TBTC and its metabolite, di-n-butyltin chloride (DBTC), in the liver were analyzed by means of gas chromatography for 14 days after the treatment. The maximum concentrations of TBTC and DBTC appeared one day after the administration, and decreased rapidly thereafter. The concentration of DBTC was found to be higher than that of TBTC throughout the experimental period.

Alanine Transaminase↗

PubMed1992

Malignant lymphoma in the mesentery with immune thrombocytopenia.

A 69-year-old man was referred to our hospital for further evaluation of an abdominal mass. After admission, he was suspected of having a malignant mesenteric tumor. Laboratory data disclosed thrombocytopenia with increased levels of platelet-associated immunoglobulin G. On surgery, the tumor involved the ileal mesentery, invading the urinary bladder and mucosal surface of the terminal ileum. The diagnosis of mesenteric lymphoma with immune thrombocytopenia was made. Complete remission was obtained after surgery and the subsequent three courses of combination chemotherapy. However, thrombocytopenia still persisted. This rare presentation is discussed with a review of the available literature.

Aged↗

PubMed1992

Contralateral development of acute subdural hematoma following surgery for chronic subdural hematoma--case report.

An unusual case of acute subdural hematoma developed after drainage of chronic subdural hematoma in a 71-year-old male. The acute subdural hematoma was located over a membranous layer in the subdural space similar to the outer membrane of the chronic subdural hematoma. Intraoperatively, bleeding from the bridging vein and oozing from the superior sagittal sinus were observed. The membranous layer probably separated from the dura mater following decompression after drainage of the contralateral hematoma, and this separation then damaged the bridging vein and superior sagittal sinus, resulting in the acute subdural hematoma.

Acute Disease↗

PubMed1992

Histopathological reactions of calcium phosphate cement.

Calcium phosphate cement (CPC) consisting of Ca4 (PO4)2O and CaHPO4 (2H2O) was recently developed. This study evaluated in vivo aspects of CPC and CPC mixtures compared to those of commercial hydroxyapatite (HP) and several endodontic materials: Grossman's cement (GC), calcium hydroxide-iodine paste (CHP) and gutta-percha plate (GP). Biocompatibility of subcutaneous implants in Donryu rats was evaluated after one month. Results showed very slight inflammatory reactions from CPC, CPC mixtures and HP. The materials were surrounded by thin fibrous connective tissues with a small number of lymphocytes and plasma cells. Severe inflammatory reactions were provoked by GC. Granulation tissues induced by CHP resembled those of pseudoxanthomatous granuloma. The GP material was encapsulated by relatively thick fibrous connective tissues with little inflammatory reactions.

Animals↗

PubMed1992

[A case of chronic scrotal hematocele and review of the literature].

A 38-year-old man visited our hospital because of swelling of left scrotal content. He had no history of trauma of scrotum, fever, pain or dysuria. Physical examination revealed a tumor larger than a fist in the left scrotum. Ultrasonography revealed an echogenic mass with echolucent area in the scrotum. Surgical extirpation of the left scrotal tumor was performed under the diagnosis of left testicular tumor. The mass was encapsulated by a white fibrous membrane and was 700 g in weight. The tumor contained 200 ml of dark brown pus-like material. Histological examination revealed deposition of cholesterine crista and infiltration of lymphocyte in tunica vaginalis with extremely atrophic testis, destructive spermatogenesis and atrophic epididymis. Twenty one cases of chronic scrotal hematocele have been reported in the Japanese literature. The age of the patients reported was 38 to 77 years old with a mean age of 65 years. Orchiectomy was done under the diagnosis of testicular tumor in 20 of the 21 cases. Our case was thought to be of an idiopathic chronic scrotal hematocele. The disease should be considered even in the absence of a particular cause such as injury and inflammation of scrotal content.

Adult↗

PubMed1992

[Intracranial primary malignant lymphoma following Behçet's disease--case report].

We reported a case of intracranial primary malignant lymphoma following Behçet disease treated with colchicine. A 43-year-old female with a past history of oral ulcer and folliculitis visited the Department of Ophthalmology on December, 1990, because of her impaired visual acuity. A diagnosis of uveitis due to incomplete type Behçet disease was made from funduscopic examination and her past history. She had been received 1.0mg/day colchicine for six months in the outpatient clinic. She was referred to our department on August 19, 1991, with nausea and headache. On admission, neurological examination revealed slight right cerebellar ataxia showing dysmetria and dysdiadochokinesis. Computed tomography scan and magnetic resonance images demonstrated a malignant lymphoma in the left cerebellar hemisphere. Stereotaxic biopsy resulted in the B cell type malignant lymphoma (Diffuse large cell type). Galliumscintigraphy, physical examination and peripheral blood examination disclosed no systemic abnormalities. There was a reduction of lymphocyte's response to PHA (phytohemagglutinin) stimulation (1.24). The tuberculin reaction was negative. Colchicine was discontinued and the therapy with radiation and prednisolone (20 mg/day) was started under the diagnosis of intracranial primary malignant lymphoma. She was discharged without any neurological deficits on November 25, 1991. She still suffers from impaired visual acuity, but has no problems in daily life. To our knowledge no intracranial primary malignant lymphoma following Behçet disease has been reported previously. The relationship between Behçet disease treated with colchicine and the occurrence of malignant lymphoma is discussed. In our case we speculated that malignant lymphoma might have occurred in an immunosuppressive state due to administration colchicine.

Adult↗