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T Tamura

Publications and source records attributed to T Tamura.

At least 829 records · Page 46Linked to original sources
PubMed1991

Role of a GC-rich motif in transcription regulation of the adenovirus type 2 IVa2 promoter which lacks typical TATA-box element.

Promoter of the adenovirus type 2 IVa2 (IVa2) gene does not have a TATA-box element, hence it is considered to be a model of cellular TATA-less promoters. In vitro transcription of the IVa2 promoter in HeLa cell extracts identified a proximal cis-element around -40 relative to the transcription start site. DNase I footprint analysis revealed the presence of a DNA-binding factor which interacts with sequences ACCCCTCCCACTTAG at -50. Competition footprint analysis and sequence comparisons showed that the IVa2 proximal promoter element is equivalent to the GC-box, the Sp1-binding site.

Adenoviruses, Human↗
PubMed1991

[A case of fibrous dysplasia (McCune Albright syndrome) associated with acromegaly].

We report a case of a 47-year-old woman with McCune-Albright syndrome associated with unusual growth-hormone and prolactin hypersecretion. Acromegaly was suspected on clinical examination, and she was referred to us. She had no history of precocious puberty or pathological fracture. She was 154cm tall, weighing 62kg with so-called acromegalic facies. There were two lumps, one of which was on her right lateral forehead. The other on the right lower extremity seemed to be due to a bone deformity. Some brown pigmented macules with irregular borders were present on her lips and oral mucosa. Endocrine examination revealed elevated basal levels of plasma GH (54ng/ml) and PRL (36.2ng/ml), which paradoxically increased after injection of TRH. Plasma levels of these hormones did not change after LHRH test, and plasma GH level increased after GHRH test. A skull X-ray film showed a double floor of the sella turcia and hyperostotic formation of the right sphenoid bone. MRI and CT showed a tumor shadow in the right sella turcica. Bone roentogenography of the right fibula and tibia showed a large centrally expanding lesion with a ground-glass or cystic appearance and a thin cortex. The left fibula showed a similar lesion. We recognized similar findings in other bones which also showed abnormal accumulation in a radionuclide bone scan with 99mTc. On the basis of physical, endocrinological and roentogenographical examination, we diagnosed her as displaying McCune-Albright syndrome. We operated on her by transsphenoidal surgery and confirmed a functioning chromophobe adenoma which was removed during surgery. She has been free of GH and PRL hypersecretion since then. The pathology of the sphenoidal sinus affected with fibrous bone was in accordance with the findings of fibrous dysplasia. McCune-Albright syndrome (MCAS) is known as a syndrome characterized by polyostotic fibrous dysplasia and cutaneous pigmentation and multiple endocrinopathy. Its etiology is unknown. This syndrome with acromegaly is rare, and although 26 cases have been described in literature, pathological examinations have been undertaken in only three cases. This case was very rare and valuable because, by operating on her by the transsphenoidal route in spite of the sphenoidal sinus being affected with fibrous bone, we were able to confirm a chromophobe adenoma secreting both GH and PRL. We recognized that acromegaly with MCAS was endocrinologically, morphologically and immunohistologically the same as acromegaly without MCAS. Therefore, we concluded that acromegaly with MCAS is much the same as acromegaly without MCAS.

Acromegaly↗
PubMed1991

Demonstration of a transcription element in vitro between the capping site and translation initiation site of the mouse myelin basic protein gene.

A transcription element was identified, by in vitro analyses, just downstream from the capping site of the mouse myelin basic protein (MBP) gene. Deletion of this element caused a dramatic drop of transcription efficiency in mouse brain, rat liver and HeLa cell nuclear extracts, regardless of the form of DNA being closed circular or linear form. DNase I footprint analysis demonstrated the presence of a ubiquitous trans-acting factor for this region. This element functioned even when it is located in the normal direction downstream from the adenovirus major late promoter. Mutation analysis suggested that an essential part of the downstream element was located between +25 and +45.

Animals↗
PubMed1991

Phase I study and pharmacological analysis of cis-diammine(glycolato)platinum (254-S; NSC 375101D) administered by 5-day continuous intravenous infusion.

A phase I study of cis-diammine(glycolato)platinum (254-S; NSC 375101D) was conducted in 15 patients with refractory or relapsing malignancy by 5-day continuous i.v. infusion. Three to 5 patients per dose were given 50, 75, 87.5, or 100 mg/m2/120 h (10-20 mg/m2 daily for 5 days). Toxicity evaluation and pharmacokinetic analysis were performed in 15 and 14 patients, respectively. Thrombocytopenia and neutropenia were the dose-limiting toxicities at the maximum tolerated dose of 87.5 mg/m2/120 h (17.5 mg/m2/day); however, nonhematological toxicities including renal toxicity, nausea and vomiting, and peripheral neuropathy were mild and well tolerated. The nadir of platelets and neutrophils was observed 4 and 5 weeks, respectively, after the initiation of drug infusion. Plasma and urine samples were obtained during and after infusion for quantification by atomic absorption spectrophotometry of total and free platinum levels derived from 254-S. The maximum level of total platinum was obtained after 120 h of infusion, whereas the steady state concentration of free platinum in the patients given 75 mg/m2 or more was over 0.1 microgram/ml. Free platinum levels declined monophasically, with half-lives of 0.65-2.56 h/100 mg/m2 dose. The mean area under the concentration versus time curve (AUC) in the patients treated with 75 mg/m2 was 1069 micrograms/ml, which was similar to that obtained in the patients receiving 100 mg/m2 of 254-S by i.v. drip infusion over 30 min. There was a direct correlation between the dose administered and the AUC of platinum (R = 0.757, P = 0.002) or the steady state plasma concentration of free platinum (R = 0.763, P = 0.002). The percentage of platinum excreted in urine 144 h after the initiation of infusion ranged from 73.1 to 100% for each dose level. No significant relationship was established between creatinine clearance in patients before treatment and the AUC or steady state concentration of free platinum. The plasma platinum AUC showed a linear correlation with the percentage of change in leukocytes [formula: see text] (R = 0.736, P = 0.003). In conclusion, the recommended phase II dose for a continuous infusion of 254-S is 75.5 mg/m2/120 h every 6 hours.

Adult↗
PubMed1991

Mechanisms underlying the slow onset of action of a new dihydropyridine, NZ-105, on a cultured smooth muscle cell line.

The inhibitory effect of a new dihydropyridine derivative, (+/-)-2-[benzyl(phenyl)amino]ethyl-1,4-dihydro-2,6-dimethyl-5- (5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorinan-2-yl)-4-(3-nitrophenyl )-3- pyridinecarboxylate hydrochloride (NZ-105), on whole cell Ca2+ current (ICa) in cultured vascular smooth muscle cells was investigated with the patch clamp technique. NZ-105 blocked ICa in a concentration-dependent manner when the command pulse ranged from +10 mV to -50 mV. The inhibitory effect of NZ-105 appeared at concentrations higher than 10 pmol/l and it blocked ICa completely at a concentration of 1 nmol/l. The concentration which produced the half-maximal inhibitory effect was estimated to be around 20 pmol/l. NZ-105 (500 pmol/l) completely blocked ICa elicited by depolarization to +10 mV at a holding potential of -40 mV, whereas it blocked ICa by only 67% at a holding potential of -90 mV. NZ-105 (100 pmol/l) shifted the steady-state inactivation curve by 40 mV to more negative potentials without affecting its slope factor. The blocking time constant of 500 pmol/l NZ-105 was 57.6 +/- 9.9 s at a holding potential of -70 mV. These results indicate that NZ-105 has characteristics typical of dihydropyridines and binds to Ca2+ channels of vascular smooth muscle cells with a high affinity. They also suggested that the slow onset of its action is due to the slow binding of the drug to Ca2+ channels.

Animals↗
PubMed1991

A t(Y;15) translocation with a deletion of the proximal Yq in a boy with mixed gonadal dysgenesis.

A Japanese boy with genital malformation and mixed gonadal dysgenesis is described. The karyotype appeared to be 46,X t(15;Y)(p13;q11). A comparison of the Q-positive segment on der(15) with that of the paternal Y chromosome revealed, however, the loss of over half of the Q-positive segment from the paternal Y during t(15;Y) translocation. The father had an unusually long Y chromosome that corresponded to a chromosome 18. DNA analysis further revealed a deletion of the non-fluorescent part of the long arm of the Y chromosome spanning interval 5-6.

Blotting, Southern↗
PubMed1991

Blockade of Cl channels by organic and inorganic blockers in vascular smooth muscle cells.

The effects of Cl channel blockers on large-conductance (LC-type) Cl channels of cultured vascular smooth muscle cells (VSMC) were studied in order to characterize the channel pharmacologically. Intracellular disulphonic stilbene derivatives, such as 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid (DIDS) and 4-acetamido-4-isothiocyanostilbene-2,2'-disulphonic acid (SITS) inhibited Cl channel activity in a dose-dependent manner. An obvious inhibitory effect of DIDS in this condition was obtained at concentrations higher than 5 microM, and the complete inhibition was obtained at around 100 microM, which was almost 10 times less than the effective dose of SITS. The inhibitory effect of DIDS was reversible at a drug concentration of lower than 50 microM. Single-channel conductance decreased as the concentration of DIDS increased. This decrease in the conductance was a consequence of unresolved openings of the channel due to fast blocking and unblocking rates of the drug. The Cl channel was also obviously inhibited by extracellular DIDS at a concentration of 1 mM. In addition, in cell-attached patches, 500 microM DIDS applied extracellularly inhibited Cl channel activated by the application of polymyxin B. We also investigated the effect of Zn on Cl channels in VSMC. Intracellular Zn dose dependently and reversibly blocked the channel at the positive intracellular potential range, whereas at the negative intracellular potential range it did not block the channel activity. Results in this study suggest the diversity of Cl channels among various tissues.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1991

Prediction of the antitumor activity of new platinum analogs based on their ex vivo pharmacodynamics as determined by bioassay.

We report the predictive model for the clinical response of new platinum analogs against lung cancer by a bioassay using human lung-cancer cell lines including small-cell (SCLC) and non-small-cell lung cancer (NSCLC). Exponentially growing cells of six different SCLC and six NSCLC lines were exposed to different concentrations of the three platinum compounds, cisplatin, carboplatin, and 254-S in a double-agar colony-forming cell assay. The concentrations inhibiting 50% of colony formation (IC50 value) for cisplatin, carboplatin and 254-S in SCLC cell lines were significantly lower than those in NSCLC cell lines. A total of 15 patients entered the pharmacological study. In all, 80 mg/m2 cisplatin, 450 mg/m2 carboplatin, and 100 mg/m2 254-S were each given to five patients by intravenous drip infusion. Bioassay as well as chemical assay was achieved by clonogenic techniques using NCI-H-69 (SCLC cell line) and PC-9 (NSCLC cell line) as target cells. Biological comparison of antitumor activity was performed on the basis of the antitumor activity of patients' plasma using the antitumor index (ATI), which was defined as the area under the percentage of colony suppression versus time curve obtained by bioassay and calculated by the trapezoidal rule. When NCI-H-69 and PC-9 were used as target cells for bioassay, colony-inhibitory activity was revealed by the ATIs. The ATIs obtained by bioassay showed better correlation than the AUCs obtained by chemical assay with the clinical response for cisplatin and carboplatin against SCLC and NSCLC, according to the following equation: [Reported Response (%)] = 11.5668 + 0.0014 x [ATI] (r = 0.97). The response rates for 254-S against SCLC and NSCLC were predicted by this formula to be 40%-65% and 14%-16%, respectively. 254-S is prospectively suspected of having the same, if not more, activity then carboplatin against SCLC and of having almost the same activity as cisplatin against NSCLC.

Antineoplastic Agents↗
PubMed1991

Photoplethysmography. Part 1. Comparison with laser Doppler flowmetry.

Photoplethysmography (PPG) and laser Doppler flowmetry (LDF) were compared and evaluated. The comparison was accomplished considering differences in physical principles and geometrical and optical conditions. Changes in human skin perfusion were induced by cold and hot water provocation on limited areas of the finger and the forearm. The results showed that LDF and PPG, using red light at 630-660 nm and a commercial PPG probe, were in general equally sensitive in detecting a blood perfusion increase following a skin temperature elevation. However, we also found that PPG occasionally showed an inverse response to a skin temperature elevation, especially in finger skin. Furthermore, the study indicated that laser light is unsuitable as a light source in PPG using optical fibres of small diameter and with no fibre separation. It was also found that the physical dimensions of the probe (including the light source and photodetector) play an important role in determining the measuring volume and the quality of the signal.

Hot Temperature↗
PubMed1991

Bidirectional cavopulmonary anastomosis using vertical vein for right isomerism, pulmonary atresia, and TAPVR.

An 8-year-old girl who was diagnosed as having right atrial isomerism, pulmonary atresia, butterfly-shaped juxtaductal pulmonary arterial stenosis, total anomalous pulmonary venous return of the supracardiac type, regurgitant common atrioventricular valve, and univentricular heart of the right ventricular type underwent bilateral, bidirectional cavopulmonary anastomosis using a vertical vein and anastomosis between the common pulmonary venous trunk and atrium. The surgical procedure in this patient is described.

Anastomosis, Surgical↗
PubMed1991

IL-2 production by B cells stimulated with a specific antigen.

The ability of a specific antigen (Ag) to stimulate B cells to produce IL-2 was examined with a murine B lymphoma line, A20-HL, which expressed surface IgM specific for trinitrophenyl (TNP). The culture supernatant of A20-HL cells stimulated with TNP3.9-ovalbumin (-OVA) or anti-IgM goat IgG contained an activity which supported the proliferation of an IL-2-dependent T cell line, CTLL-2. Neither TNP3.9-OVA nor anti-IgM antibody stimulated the parent line, A20.2J, which did not bear TNP-specific sIg, whereas anti-mouse Ig rabbit IgG F(ab)2 did stimulate both A20-HL cells and A20.2J cells. The active material in the culture supernatant was identified as IL-2 based on the experiments in which the activity was inhibited by anti-IL-2 mAb, and IL-2 mRNA was expressed in A20-HL cells stimulated with TNP3.9-OVA or anti-IgM antibody. These results support the conclusion that a specific Ag can stimulate A20-HL cells to produce IL-2. For IL-2 production, TNP receptors on A20-HL cells have to be appropriately cross-linked, inasmuch as either TNP3.9-OVA or TNP6.7-OVA was much more effective than TNP1.2-OVA and TNP22.9-OVA in the induction of IL-2 production by A20-HL cells.

Antigens↗
PubMed1991

Cyclic adenosine monophosphate promotes the proliferation of chicken granulosa cells in culture.

The aim of this study was to determine if cAMP regulates the proliferation of chicken granulosa cells and if there is a difference in the effects of cAMP on the granulosa cell proliferation between the largest follicle (F1) and the smaller follicles. Granulosa cells collected from F1 and the third largest follicle (F3) were cultured in medium M199 containing 1% calf serum with or without dibutyryl cAMP (dbcAMP). Proliferation of granulosa cells of F1 was promoted by dbcAMP in a dose-dependent manner. The most effective concentration of dbcAMP to promote the granulosa cell proliferation was 2 mM. In the culture without dbcAMP, the number of the granulosa cells was not changed significantly for 6 days, whereas, in the presence of 2 mM dbcAMP, the number of the granulosa cells was markedly increased during 2 to 6 days. The proliferation of the granulosa cells of F3 was stimulated by dbcAMP in the same manner as that of F1. Morphologically, the granulosa cells of F1 and F3 cultured for 2 days had a sheet-like appearance in control culture, whereas they were contracted, leaving finger-like cytoplasmic processes attached to the adjacent cells and substratum in the presence of 2 mM dbcAMP. After 6 days culture, approximately 90% of the cells of F1 stained positive for 3 beta-hydroxysteroid dehydrogenase activity in 2 mM dbcAMP-containing culture, whereas only about 20% of the cells were positive in control culture. These results suggest that cAMP promotes the proliferation of the granulosa cells during the follicular growth and this response of granulosa cells to cAMP is similar for F1 and F3.

Animals↗
PubMed1991

Enzymatic dispersion of mast cells from human sinus mucosa: characterization of histamine release and its comparison with chopped fragments of the tissue.

Functional characteristics of mast cells in chopped fragments from sinus mucosa, which was dissected from patients with chronic sinusitis, were compared with those from dispersed cells prepared by enzymatic treatment. The results obtained in this study were the following. (1) Both chopped fragments and dispersed cells released histamine in a dose-dependent manner when incubated with anti-IgE. However, higher histamine release was always observed in dispersed cells. (2) Although no differences in the ability to reduce histamine release with salbutamol or forskolin could be observed between chopped fragments and dispersed cells, staurosporin and p-bromophenacyl bromide were more active on dispersed mast cells than chopped fragments. (3) Passive sensitization of dispersed cells with an allergic serum containing IgE to mite could be achieved only after elution of IgE on the cells with lactic acid.

Acetophenones↗
PubMed1991

A randomised clinical trial of vindesine plus cisplatin versus mitomycin plus vindesine and cisplatin in advanced non-small cell lung cancer.

This trial was carried out to evaluate the therapeutic benefit of the addition of mitomycin to vindesine plus cisplatin (80 mg/m2) in 126 previously untreated non-small cell lung cancer (NSCLC) patients. 124 patients were evaluable for toxicity and survival and 122 for response. No patient achieved complete response. The partial response rate (PR) in the vindesine plus cisplatin (VP) and mitomycin plus vindesine and cisplatin (MVP) groups were 23% (14/62) vs. 35% (21/60) (P = 0.13) with a median duration of response of 23 vs. 37 weeks (P = 0.071), respectively. Time to progression (TTP) and survival time (ST) were similar for both treatment arms [median TTP; 14 vs. 21 weeks (P = 0.10), median ST; 9.1 vs. 10.5 months (P = 0.94), respectively]. No difference in the frequency of side-effects was observed except that WHO grade 3 and 4 leukopenia was higher in the MVP group. In multivariate analysis, the significant predictors of survival were serum albumin, sex, performance status, lactate dehydrogenase and stage. In conclusion, the addition of mitomycin to the VP regimen appears to have limited value in advanced NSCLC.

Adult↗