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T Fujiwara

Publications and source records attributed to T Fujiwara.

At least 721 records · Page 40Linked to original sources
PubMed1994

[Quantitative analysis of DNA topoisomerase I activity in human and rat glioma: characterization and mechanism of resistance to antitopoisomerase chemical, camptothecin-11].

Camptothecin-11 (CPT-11) is a new derivation of camptothecin, a plant alkaloid antitumor agent. Previous studies indicated that antitumor activity of CPT-11 was mediated through interaction of the drugs with its target enzyme, DNA topoisomerase I (topo I). In this study, we studied the relation between sensitivity to CPT-11 and topo I activity of glioma cells. Furthermore, we established CPT-11 resistant cell lines in order to elucidate potential mechanisms of drug resistance. A clear correlation between the sensitivities to CPT-11 and topo I activities in surgical glioma specimens was demonstrated. Activities of topo I in CPT-11 sensitive group (IC50 values for CPT-11; < 50 micrograms/ml) tended to be higher than those in CPT-11 resistant group (IC50 values; > or = 50). Topo I activity may serve as a novel marker to predict the sensitivity of gliomas to topo inhibitors. CPT-11 resistance cell lines (T98G/CPT-11 and C6) respectively exhibit a 5.4- and 7.3-fold increase in resistance to CPT-11. No differences in topo I activity and intracellular accumulation of CPT-11 were observed between parent and CPT-11 resistant lines. On the other hand, topo I from T98G/CPT-11 and C6/CPT-11 cells were at least 4- and 2-fold resistant to the inhibitory effect of the CPT-11 on the relaxation activity of topo I in comparison with their parent lines. This enzymological difference may be responsible for the resistance to CPT-11.

Animals↗
PubMed1994

[How to use glucocorticoids in ophthalmology].

Administration of glucocorticoid, one of the corticosteroid hormones, is one of the most important therapeutic strategy in ophthalmological treatment. Almost all kinds of glucocorticoid agents are commercially available for various ocular diseases, including cortisone, hydrocortisone, prednisolone, methylprednisolone, triamcinolone, dexamethasone, paramethasone, betamethasone and fluolometholone. Glucocorticoids are administrated in preparations of eye drops, ointments, injections and tablets for local and systemic use. Systemic glucocorticoid treatment should, in general, only be considered when local treatment with eye drops or with injections fail, when the disease is bilateral, or when systemic findings indicate the need. "Producing less severe side effects or complications, obtaining the most efficacy, with long duration" is the main principles in ophthalmological use of glucocorticoids. Steroid cataract (posterior subcapsular opacity) and steroid glaucoma (intraocular pressure elevation) are the two main ocular complications of glucocorticoid administration. Serial slitlamp examination and tonometry are essential to prevent them.

Drug Administration Routes↗
PubMed1994

[A case of hypertrophic obstructive cardiomyopathy (HOCM) complicated by infective endocarditis (IE) and mitral regurgitation (MR)].

The case of a 56-year-old man who underwent mitral valve replacement due to HOCM complicated by IE and MR is reported. Preoperative 2D echocardiographic assessment of the mitral valve revealed systole anterior motion (SAM) and vegetation, and color flow Doppler echocardiographic examination revealed severe mitral regurgitation. The left ventricular out-flow tract gradient decreased from 140 mmHg preoperatively to 60 mmHg postoperatively. Mitral valve replacement should be considered in patients with associated IE and severe MR.

Cardiomyopathy, Hypertrophic↗
PubMed1994

[A case of acute retrograde type I dissecting aneurysm of aorta underwent three operations].

A 54-year-old man with an acute retrograde type I dissecting aneurysm of the aorta underwent three operations for four years. The first operation was by the Collins method, the second was a graft replacement of the descending aorta, and the third involved a graft replacement of the ascending aorta and aortic arch, revascularization of the aortic branches and replacement of the aortic valve. In operations on acute retrograde type I dissecting aneurysms of the aorta, the methods of Koster or Collins are in appropriate in cases where sufficient entry treatment is impossible, and graft replacement of the ascending aorta at least is considered to be necessary.

Acute Disease↗
PubMed1994

[Evaluation of colon diseases by using new method of extracorporeal ultrasonic examination during usual colon endoscopy].

Generally two types of ultrasonic colon examination method are carried out. One is extracorporeal ultrasonographic examination (US). And another is endoscopic ultrasonographic examination (EUS). US is technically easy but is difficult to take good image of colon diseases. EUS can give us good and sufficient informations. But it is technically difficult and gives much trouble to patients. During usual endoscopy, we have tried extracorporeal ultrasonic examination by filling de-aired water around the diseased colon area. With this new method, we could easily identify the disease and got much better picture than usual US. And this new method gave almost no trouble and pain to examinees in comparison with EUS.

Calcinosis↗
PubMed1993

Molecular cloning and sequencing of the fimbrilin gene of Porphyromonas gingivalis strains and characterization of recombinant proteins.

The fimA gene encoding the subunit protein of fimbriae, fimbrilin, from nine strains of Porphyromonas gingivalis was cloned using polymerase chain reaction and the nucleotide sequence was determined. Analysis of the nucleotide and the deduced amino acid sequences revealed that the fimA gene of the test strains was composed of 1044 to 1083 bp, and the molecular weight of the deduced polypeptides was calculated to be 37,527 to 38,239. All the test strains shared the same or similar sequences, but simultaneously considerable differences in the sequences were found among the strains. Western blot analysis using rabbit antiserum to P. gingivalis 381 fimbriae demonstrated that the recombinant fimbrilins of 8 out of 9 strains expressed in Escherichia coli reacted with the antiserum exhibiting a 43 to 48 kDa band. Taken together, these results indicate that four genetical clusters are noted among the fimA gene of P. gingivalis strains.

Amino Acid Sequence↗
PubMed1993

A retroviral wild-type p53 expression vector penetrates human lung cancer spheroids and inhibits growth by inducing apoptosis.

Multicellular tumor spheroids approximate the three-dimensional configuration of primary and metastatic tumors. The effects of retrovirus-mediated transduction of wild-type p53 (wt-p53) were studied on multicellular tumor spheroids of human non-small cell lung cancer cell lines H322a, the p53 gene of which is homozygously mutated at codon 248, and WT226b, which has endogenous wt-p53. The growth of WT226b spheroids was not affected by exogenous wt-p53 transduction; the growth of H322a spheroids, however, was significantly inhibited by the addition of wt-p53 virus stocks. Transduction of cells by the wt-p53 retroviral vector and penetration of multiple cell layers in H322a spheroids was demonstrated by in situ polymerase chain reaction/hybridization with the neomycin-resistant neo probe. Apoptotic changes indicating programmed cell death were observed in H322a spheroids treated with the wt-p53 virus. These results suggest that retroviral vectors can penetrate into multiple cell layers of three-dimensional tumor masses and induce potentially therapeutic effects.

Apoptosis↗
PubMed1993

Allocation of mouse cerebellar granule cells derived from embryonic ventricular progenitors--a study using a recombinant retrovirus.

Granule cells of the mammalian cerebellar cortex originate from embryonic progenitors present in the ventricular germinal layer. To investigate the allocation fate of these ventricular progenitors in the mouse, we labeled a few of them on embryonic day 13 with a recombinant retrovirus carrying lacZ which encodes E. coli beta-galactosidase (beta-gal), and the labeled cells in the postnatal cerebellar cortex were detected by beta-gal histochemistry. In the postnatal cerebellar cortex, the virally-labeled beta-gal+ granule cells formed discrete clusters. These clusters were not compactly packed with the beta-gal+ cells, and there was intermingling with beta-gal- granule cells. Neither beta-gal+ Purkinje cells nor glia were found to be included in the clusters. Most of the granule cell clusters were incompatible with the functional areas of the cortex. These results suggest: (1) granule cells derived from individual ventricular progenitors are allocated in clusters and are not extensively dispersed, (2) granule cells descended from one progenitor may mix with their neighbors that are descended from another progenitor, (3) the allocation fate of the ventricular progenitors of granule cells is not restricted to the functional areas of the cerebellar cortex.

Animals↗
PubMed1993

Characterization of four new cell lines derived from small-cell gastrointestinal carcinoma.

Four human small-cell gastrointestinal carcinoma cell lines were established from tumor tissues of patients with esophageal, gastric or rectal cancer, and were studied morphologically and biochemically in comparison with small-cell lung carcinoma (SCLC) cell lines and common gastric cancer cell lines. Cells from all the small-cell gastrointestinal carcinoma lines were as small as classic SCLC cells and had characteristic neurosecretory granules. Cells from only one line grew as tightly packed spherical aggregates of floating cells, and those of the other 3 grew attached to substrate. Although high levels of creatine kinase brain isoenzyme (CK-BB) were detected in all 4 cell lines, 2 of them showed low levels of aromatic L-amino-acid decarboxylase and 3 had low levels of neuron-specific enolase (NSE). None of the lines showed simultaneous elevation of enzymes. C-myc, N-myc, and L-myc were not amplified in any of the cell lines, but c-myc mRNA was expressed in 2 lines. Our findings indicate that all small-cell gastrointestinal carcinoma cells examined belong to the variant type which is used in the classification of SCLC. Furthermore, the ECC18 line, derived from esophageal cancer, seemed to be of true endocrine cell origin, while the 3 other small-cell gastrointestinal carcinoma lines seemed to arise via neoplastic neometaplasia from adenocarcinoma cells to endocrine cells.

Aged↗
PubMed1993

Purification, characterization and molecular cloning of an acidic amino acid-specific proteinase from Streptomyces fradiae ATCC 14544.

We have isolated a novel acidic amino-acid-specific proteinase from Streptomyces fradiae ATCC 14544, using benzyloxycarbonyl-L-Phe-L-Leu-L-Glu-p-nitroanilide (Z-Phe-Leu-Glu-pNA) as a substrate. A proteinase, which we propose to call SFase, was purified from the culture filtrate by salting out, repeated S-Sepharose chromatography, and affinity chromatography (CH-Sepharose-Phe-Leu-D-Glu-OMe). The purified enzyme showed a single band having an apparent molecular weight of 19,000 on sodium dodecyl sulfate polyacrylamide gel electrophoresis. When synthetic peptides were used as substrates, SFase showed high specificity for Z-Phe-Leu-Glu-pNA. Comparison with nitroanilides of glutamic acid and aspartic acid as substrates revealed that the reactivity was about 10-fold higher for a glutamyl bond than an aspartyl bond. SFase selectively hydrolyzed the -Glu-Ala-bond of two glutamyl bonds in the oxidized insulin B-chain within the initial reaction time until the starting material was completely digested. Diisopropylfluorophosphate and benzyloxycarbonyl-Phe-Leu-Glu chloromethylketone completely inhibited SFase, while metalloproteinase inhibitors, such as EDTA and o-phenanthrolin, did not inhibit the enzyme. The findings indicate that SFase can be classified as a serine proteinase, and is highly specific for a glutamyl bond in comparison with an aspartyl bond. To elucidate the complete primary structure and precursor of SFase, its gene was cloned from genomic DNA of the producing strain, and the nucleotide sequence was determined. Consideration of the N- and C-terminal amino-acid sequences of the mature protein of SFase indicates that it consists of 187 amino acids, which follows a prepropeptide of 170 residues. In comparison with the acidic amino-acid-specific proteinase from Streptomyces griseus (Svendsen, I., Jensen, M.R. and Breddam, K. (1991) FEBS Lett. 292, 165-167), SFase had 82% homology in the amino acid sequence. The processing site for maturation of SFase was a unique sequence (-Glu-Val-), so that the propeptide could be released by cleavage of the peptide bond between Glu and Val.

Amino Acid Sequence↗
PubMed1993

Quantitative analysis of DNA topoisomerase I activity in human and rat glioma: characterization and mechanism of resistance to antitopoisomerase chemical, camptothecin-11.

Camptothecin-11 (CPT-11) is a new derivative of camptothecin, a plant alkaloid antitumor agent. Previous studies indicated that antitumor activity of CPT-11 was mediated through interaction of the drugs with its target enzyme, DNA topoisomerase I (topo I). In this study, we studied the relation between sensitivity to CPT-11 and topo I activity of glioma cells. Furthermore, we established CPT-11 resistant cell lines in order to elucidate the potential mechanisms of drug resistance. A clear correlation between the sensitivities to CPT-11 and topo I activities in surgical glioma specimens was demonstrated. Activities of topo I in the CPT-11-sensitive group (IC50 values for CPT-11; < 50 micrograms/ml) tended to be higher than those in the CPT-11-resistant group (IC50 values, > or = 50). Topo I activity may serve as a novel marker to predict the sensitivity of gliomas to topo inhibitors. CPT-11-resistant cell lines (T98G/CPT-11 and C6), respectively, exhibit a 5.4- and 7.3-fold increase in resistance to CPT-11. No differences in topo I activity and intracellular accumulation of CPT-11 were observed between the parent and CPT-11-resistant lines. On the other hand, topo I from T98G/CPT-11 and C6-CPT-11 cells was at least 4- and 2-fold resistant to the inhibitory effect of the CPT-11 on the relaxation activity of topo I, in comparison with their parent lines. This enzymological difference may be responsible for the resistance to CPT-11.

Animals↗
PubMed1993

Development of inositol trisphosphate-induced calcium release mechanism during maturation of hamster oocytes.

Mature hamster eggs exhibit repetitive increases in the intracellular Ca2+ concentration ([Ca2+]i) at fertilization, caused by inositol 1,4,5-trisphosphate (InsP3)-induced Ca2+ release (IICR) from stores. Oscillating Ca2+ rises also occurred in inseminated immature oocytes at the germinal vesicle (GV) stage but the peak [Ca2+]i of each response was about half of that in mature eggs. Like the responses to sperm in the mature egg, those in the immature oocyte were also blocked by injection of a monoclonal antibody against the InsP3 receptor (18A10). Compared with mature eggs, immature oocytes were more sensitive to externally applied serotonin which caused repetitive IICR, but each response was smaller. The development of the IICR mechanism during oocyte maturation was investigated using iontophoretic injection of InsP3 and Ca2+ imaging with fura 2. In immature oocytes the rise in [Ca2+]i with an InsP3 pulse of 1.2 nA for 1 sec was 35% of that in mature eggs. The response increased with increasing doses of InsP3. The nearly maximum response, obtained with a 20-nA 2-sec pulse, was 80% of that in mature eggs, suggesting that immature oocytes are less sensitive to InsP3 but that most of Ca(2+)-releasable stores are already present in the immature oocyte. IICR developed in two phases during in vivo maturation. The sensitivity to InsP3 increased gradually between the GV stage and prometaphase of the first meiosis. Then a nonlinear dose-response relation developed during the second meiosis to metaphase II, resulting in regenerative, propagating Ca2+ release induced by a threshold pulse of 1 nA for 1 sec in mature eggs. Similar changes occurred during in vitro maturation of oocytes isolated from follicles at GV stage and cultured for up to 16 hr. The development of IICR is thought to be a prerequisite factor for the acquisition of the ability of an egg to undergo normal fertilization.

Animals↗
PubMed1993

Upstream regulatory sequences from two beta-conglycinin genes.

Genes encoding the beta-conglycinin seed storage proteins of soybean are expressed only in seeds during specific stages of development. The different subunits of beta-conglycinin, alpha', alpha and beta, are encoded by distinct members of a gene family. Yet there are marked differences in the regulation of the genes encoding the alpha'/alpha and beta subunits. Previous work (Chen et al., EMBO J 7: 297-302, 1988) identified a seed specific transcriptional enhancer upstream of a gene encoding the alpha' subunit. Mutations were made within this region to discern its functional components. Among those identified is a 62 bp region (between -77 and -140) that contains a vicilin box consensus sequence as well as a sequence that binds the soybean nuclear factor SEF4 in vitro. A second region, which contains a sequence homologous to the core of the legumin box consensus (i.e., CATGCAT-like or RY repeat element) at -246, was also shown to affect the activity of this enhancer in transgenic plants. A series of 5' terminal deletions were used to identify regulatory elements upstream of the beta subunit gene. Two regions were identified (from -553 to -442 and from -308 to -72) that, when deleted, led to a marked reduction in gene expression. Both of these elements contain sequences that bind SEF4 in vitro. The distal element also contains an AT-rich segment that recognizes a second nuclear factor, SEF1, in vitro. Neither of these elements contains any homology to the vicilin box consensus.

Antigens, Plant↗
PubMed1993

Evaluation of the treatment response of lung cancer with positron emission tomography and L-[methyl-11C]methionine: a preliminary study.

We carried out a study to evaluate treatment response and residual mass in lung cancer with positron emission tomography (PET), using L-[methyl-11C]methionine (MET). MET tumour uptake and tumour volume measured by computed tomography (CT) before and within 2 weeks after radiotherapy or chemoradiotherapy were compared in 43 studies of 21 patients. Ten patients with local control (no recurrence) of tumour showed a larger decrease in MET uptake (65.2% +/- 12.2%) than in tumour volume (50.8% +/- 9.6%, P < 0.01). Five patients with early recurrence (from 1 to 4 months) showed smaller decreases in both MET uptake (22.2% +/- 13.5%) and tumour volume (28.6% +/- 20.0%) than those in the no-recurrence group (P < 0.01). Four patients with late recurrence (after 11 months or more) showed a similar decrease to the no-recurrence group in MET uptake (72.8% +/- 14.8%) but little change in tumour volume (18.5% +/- 19.0%), the latter result corresponding to that in the early-recurrence group. Using tumour volume only, the no-recurrence group was differentiated from both the early- and the late-recurrence group (P < 0.01), but the early-recurrence group was not differentiated from the late-recurrence group. Using the MET uptake data, the early-recurrence group was clearly distinguished from the late-recurrence group (P < 0.01), but the late-recurrence group was indistinguishable from the no-recurrence group. CT was useful in distinguishing the no-recurrence group from the groups in which there was ultimate recurrence, whether early or late. When a residual mass is seen on CT, PET seems to be helpful in evaluating tumour viability.

Adenocarcinoma↗
PubMed1993

Oxytocin solution structure changes upon protonation of the N-terminus in dimethyl sulfoxide.

With the combined use of various two-dimensional (2D) NMR techniques, a complete assignment of the 1H and 13C resonances of oxytocin, Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH2, for two molecular states, protonated and unprotonated at the N-terminal group, was performed in dimethyl sulfoxide. A small but distinct change in the backbone conformation of the six-residue cyclic moiety, associated with the protonation, was first suggested from those NMR parameters relevant to conformation, such as change with temperature in the chemical shifts of the peptide amide protons and changes in chemical shifts and homonuclear as well as heteronuclear three-bond coupling constants. The solution structures of oxytocin for the protonated and unprotonated forms were then calculated using distance analysis in dihedral-angle space, based on a relaxation matrix evaluated from quantitative NOE intensities at different mixing times. Total amounts of 93 and 105 distances were determined for the protonated and the unprotonated forms, respectively. There were 25 interresidue distances relevant to the structure of the cyclic moiety for the protonated form of oxytocin and 43 for the unprotonated form. Overall structures with the lowest target penalty function were similar between the two forms, having a beta-turn structure at the endocyclic residues of the Tyr-Ile-Gln-Asn moiety. The local backbone conformations near the N-terminus, however, were significantly different between the two forms. This was found to be due to a change in the dihedral angle of the disulfide bridge (chi ss around C-S-S-C), which closes the ring in the cyclic peptide. The dihedral angle was about +90 degrees for the unprotonated form and an intermediate value of about +45 degrees for the protonated form.

Amino Acid Sequence↗
PubMed1993

The shape and distribution of lysosomes and endocytosis in the ciliary epithelial cells of rats.

The shape and distribution of lysosomes in the ciliary epithelium of rat eyes were examined by electron microscopy combined with acid phosphatase (ACPase) cytochemistry and three-dimensional observation of 2 microns-thick sections. ACPase activity was cytochemically localized in lysosomes and trans Golgi cisternae in the non-pigmented epithelial (NPE) and pigmented epithelial (PE) cells. In NPE cells, it was shown three-dimensionally, that most lysosomes had an elongate form, up to 5 microns in length, and a diameter of 70-100 nm. These elongate lysosomes (nematolysosomes) were predominantly located in the basal region of the cells. In contrast, PE cells had spherical lysosomes distributed at random throughout the cytoplasm. However, no nematolysosomes were seen in the PE cells. When the isolated ciliary processes were incubated in a medium containing horseradish peroxidase (HRP), HRP was incorporated into the nematolysosome-like structures by pinocytosis from the basal surface of the NPE cells. These findings suggest that nematolysosomes are associated with the pinocytotic activity of NPE cells. The pinocytosis-nematolysosomal route may be involved in the uptake and degradation of macromolecules from the aqueous humor in the posterior chamber.

Acid Phosphatase↗