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T Ishida

Publications and source records attributed to T Ishida.

At least 523 records · Page 29Linked to original sources
PubMed1995

Enhancement of aromatic amino acid-nucleic acid base stacking interaction by metal coordination to base: fluorescence study on a tryptophan-Pt(II)-guanine ternary complex.

In order to investigate the effect of the Pt(II) ion on the stacking interaction between tryptophan and a guanine base, the quenching of Trp fluorescence was monitored for some systems in the absence and presence of the metal ion, and the association constants were obtained by the analysis of Eadie-Hofstee plots. All spectral data suggested that the stacking interaction is enhanced by the Pt(II) coordination to the guanine N7 atom. The result indicates the importance of the metal ion as a bookmark in the specific recognition of a nucleic acid base by an aromatic amino acid residue.

Base Composition↗
PubMed1995

Design of noncovalent trypsin inhibitor based on the X-ray crystal structure of the complex.

The inhibitory mechanism of trans-4-aminomethylcyclohexanecarbonyl-L-phenyl-alanine-4-carbo xymethylanilide (1), a noncovalent serine protease inhibitor synthesized based on previous structure-activity studies, was clarified based on the X-ray crystal structure of the complex (2.2 A resolution, R = 0.175), where the amino group of the aminomethylcyclohexane moiety was bifurcately hydrogen-bonded to the carboxyl oxygens of Asp 189 side group (specificity pocket), and the hydrogen bonds of the cyclohexanecarbonyl oxygen to NHs of Gly 193 and Ser 195 residues (oxyanion hole) and of Phe NH to Ser 195 O gamma atom (catalytic triad) were observed. In contrast, the Phe benzene moiety and terminal carboxymethylanilide of 1 were not well located on the electron density map, suggesting the conformational freedom of these P1' and P2' sites at the binding pocket. Based on these insights, trans-4-aminomethylcyclohexanecarbonyl-4-nitro-L-phenylalanine-4-+ ++benzoylanilide (2) was designed, in which the P1' and P2' sites were modified so as to effectively interact with the amino acid residues of trypsin binding pocket via hydrogen bonding and van der Waals interactions, respectively. Consequently, 2 showed 40 times higher inhibitory activity against trypsin than 1.

Crystallization↗
PubMed1995

Structure of the osteopontin gene and its promoter.

We cloned the hOPN gene and its 5' upstream region, and analyzed its exon-intron structure and potential regulatory sequences of the promoter region in comparison with those of mouse and porcine homologues. The hOPN gene consists of 7 exons that are similar to those of the mouse gene, although the hOPN gene is longer than the mouse homologue. This difference is attributable to an insertion of about 1750 bp immediately before exon 4 in the hOPN gene. A region of approximately 285 bp immediately upstream of the hOPN transcription initiation site was highly conserved and contained a number of potential cis regulatory consensus sequences. CAT analysis using SCC-3 cells demonstrated that nucleotides at positions -439 to -270, -124 to -80, and -55 to -39 contained cis-acting enhancing elements, in which the -124 to -80 element was much more active than the others. Deletion of the sequences between -474 and -270 localized the cis elements to the sequence at position -439 to -410, whereas the deletion between -124 to -80 localized it to -124 to -115, and -94 to -80 (data not shown). Gel shift analysis using synthesized double-stranded oligonucleotides corresponding to the 30 bp at position -439 to -410 (data not shown), and 10 and 15 bp regions at positions -124 to -115 and -94 to -80, respectively, as probes revealed that each probe formed one or two bands complexed with a nuclear protein prepared from SCC-3 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Expression of wild-type and mutated rabbit osteopontin in Escherichia coli, and their effects on adhesion and migration of P388D1 cells.

Recombinant wild-type rabbit osteopontin (rOP) and the protein with an aspartate-to-glutamate transposition induced by a point mutation in the rabbit OP cDNA within the Gly-Arg-Gly-Asp-Ser (GRGDS) sequence were expressed in Escherichia coli and purified to homogeneity. P388D1 cells bound rOP in a saturable manner. rOP induced adhesion and haptotaxis of P388D1 cells, whereas mutated rabbit OP (rOPmut) did not. Anti-rOP IgG F(ab')2 and synthetic GRGDS peptide inhibited rOP-mediated adhesion and haptotaxis of P388D1 cells. Fibronectin (FN)-mediated adhesion of P388D1 cells was markedly inhibited in the presence of fluid-phase rOP. Adhesion of P388D1 cells to rOP was significantly inhibited by anti-[alpha-subunits of VLA4 (alpha 4) and VLA5 (alpha 5)] monoclonal antibodies (mAbs), but not by anti-[alpha-subunit of vitronectin (VN) receptor (alpha V) or Mac-1 (alpha M)] mAb. Adhesion of P388D1 cells to FN and VN was significantly inhibited by anti-alpha V mAb but not anti-alpha 4, -alpha 5 or -alpha M mAb. Haptotaxis of P388D1 cells to rOP was significantly inhibited by anti-alpha V mAb, but not by anti-alpha 4, -alpha 5 and alpha M mAbs, whereas that to FN showed no inhibition with all three mAbs. Haptotaxis of P388D1 cells to VN was significantly inhibited by anti-alpha 5 and -alpha V mAbs but not by anti-alpha 4 and -alpha M mAbs. Similar features of inhibition of adhesion and haptotaxis of P388D1 cells to human OP were observed by mAbs. rOP had no chemotactic effect on P388D1 cells. Significant polymorphonuclear leucocyte migration was observed 3-12 h after intradermal injection of rOP into rabbits.

Amino Acid Sequence↗
PubMed1995

The role of cyclic AMP in the lipopolysaccharide-induced suppression of thymidine kinase activity in macrophage.

We observed that lipopolysaccharide (LPS, 1 micrograms/ml) can suppress [3H]thymidine incorporation into acid-insoluble fraction in a mouse macrophage cell line J774 (over 70% at 6 h) without affecting the uptake of [3H]thymidine or DNA polymerase activity. Paralleling this suppression, a decrease in the thymidine kinase (TK) activity, but not of thymidine monophosphate (TMP) kinase and thymidine diphosphate (TDP) kinase, was observed. LPS dose-dependently increased intracellular cAMP levels to about 3.5-times basal at 6 h, proportionally to the decrease of the TK activity. Elevation of intracellular cAMP by several reagents also decreased TK activity. Apparently LPS treatment elevates cAMP concentration by decreasing the low Km cAMP phosphodiesterase activity (58% at 6 h). The time course of cAMP-dependent protein kinase (PK-A) activity during the first 6 h after LPS treatment correlated with that of cAMP concentration. Treatment with a PK-A inhibitor restored about 63% of LPS-induced reduction of TK activity at 6 h. At longer times, however, there was a discrepancy between the change of cAMP concentration or PK-A activity and the reduction of TK activity. Therefore, protein kinase activation caused by the accumulation of intracellular cAMP probably triggers some mechanism responsible for the reduction of the TK activity.

Cells, Cultured↗
PubMed1995

Stereochemical aspects of the hydration of trans-anethole epoxide in the rat.

Racemic trans-anethole epoxide [1-(4'-methoxyphenyl)-propane-1,2-oxide] was incubated with water, buffers, and rat liver microsomes and cytosol and the stereochemistry of the diols produced was determined by HPLC as their dicamphanyl esters. The diol metabolites were isolated by HPLC from the urine of rats administered [1'-14C] trans-anethole and their stereochemistry determined after derivatization to their camphanyl esters. The stereochemical course of the metabolism of trans-anethole by rat liver microsomes and cytosol is discussed.

Allylbenzene Derivatives↗
PubMed1995

Lymph node cancer of the mediastinal or hilar region with an unknown primary site.

We herein report three cases of lymph node cancer of the mediastinal or hilar region, in which the primary sites could not be determined in spite of performing various systemic examinations. Two cases revealed a large cell anaplastic carcinoma in the mediastinal lymph node, while the other demonstrated a small cell carcinoma in the hilar lymph node. However, based on radiographic and pathological examinations, the primary sites could not be found in either the head and neck, lung, or abdominal organs. All cases underwent surgical resections for lymph node cancer, while two patients also received adjuvant therapy. Two patients experienced recurrence soon after treatment. Despite the rarity of this disease, lymph node cancer must always be kept in mind when an enlargement of either the mediastinal or hilar lymph node is detected in patients with an unknown primary site, and a poor prognosis is generally expected.

Aged↗
PubMed1995

Characteristics of non-small cell lung cancer 3 cm or less in diameter.

We retrospectively investigated 308 cases of non-small cell lung cancer of < or = 3 cm diameter. There were 204 adenocarcinomas, 78 squamous cell carcinomas, 15 large cell carcinomas, and 11 other carcinomas. According to TNM staging, there were one case stage 0, 208 stage I, 22 stage II, 49 stage IIIA, 15 stage IIIB, and 13 cases stage IV. T1 disease was seen in 262 cases, T2 in 19, T3 in 10, T4 in 16, and Tis in 1. N0 disease was seen in 217 cases, N1 in 30, N2 in 60, and N3 in 1. The 5-year survival rate of all cases was 63%. There were statistically significant differences among T status (T1 vs. T3, T4), N status (N0 vs. N1, N2), and M status (M0 vs. M1) (P < 0.01). The 5-year survival rates of cases with adenocarcinoma and squamous cell carcinoma were 60% and 64%, respectively. In 204 cases of adenocarcinoma, T3 disease was found in one case, T4 disease in 15 (7%), and nodal involvement (N1 + N2) was present in 69 (34%). In 78 cases of squamous cell carcinoma T3 was seen in 6 (8%), T4 in 1, and nodal involvement in 14 (18%). The incidence of T3 disease, T4, and N(+) varied significantly according to histology (P < 0.05). Our investigation suggested that cases of small-sized lung cancer were often at an advanced stage at detection, and that the spread of disease differed according to histology. The patient with small-sized lung cancer should be offered a standard operation regardless of histology.

Adenocarcinoma↗
PubMed1995

Plasma cell myeloma in unusually young patients: a report of two cases and review of the literature.

Two cases of plasma cell myeloma in unusually young patients are reported. One was a case of multiple myeloma involving the skull and ribs in a 23-year-old woman, the other of solitary myeloma of the tibia in a 21-year-old man. Both the cases were non-secretory myeloma; however, monoclonal immunoglobulins were demonstrated by immunohistochemical studies. Plasma cell myeloma in patients below the age of 30 years is extremely rare. Our literature search disclosed 20 well-documented cases of multiple myeloma and 25 cases of solitary myeloma in patients at or below the age of 30. Plasma cell myeloma may occur in young persons, so it should be considered in the pre-biopsy differential diagnosis when bone lesions radiologically consistent with myeloma are encountered in young patients.

Adult↗
PubMed1995

Conserved delta-activity in reverse enantiomeric opioid peptide.

A reverse enantiomeric peptide has a reversed amino acid sequence with enantiomeric amino acid residues compared with its parent peptide. In most cases the random change of amino acid sequence or chirality might be expected to bring about significant changes in peptide activity. However, the reverse enantiomeric peptides of Leu-enkephalin and Tyr-D-Ala-Gly-Phe-D-Leu (DADLE) have shown affinity for the opioid delta-receptor, but not for mu- or kappa-receptors. This suggests that delta-opioid receptor recognition occurs primarily through interaction with the peptide side chains, since the native opioid peptide and its reverse enantiomer are able to have similar side-chain conformation.

Amino Acid Sequence↗
PubMed1995

Tophaceous pseudogout (tumoral calcium pyrophosphate dihydrate crystal deposition disease).

Most cases of calcium deposition seen radiologically in soft tissues are caused by calcium hydroxyapatite and occur either as a complication of trauma with associated necrosis (eg, fat necrosis), generalized connective tissue diseases (eg, scleroderma), metabolic disturbances (eg, hyperparathyroidism, familial hyperphosphatemia), sarcoidosis, myeloma, or metastases. Hydroxyapatite deposits are seen at many soft tissue sites, including joint capsules, ligaments, blood vessels, dermis, etc. On the other hand, deposits of calcium pyrophosphate are seen typically in the meniscus, articular cartilage, ligamentum flavum, and intervertebral disc. They usually are punctate or linear in distribution within the meniscus or parallel to the subchondral bone end plate. We report seven cases of massive focal calcium pyrophosphate dihydrate (CPPD) crystal deposition disease (tophaceous pseudogout) that occurred in atypical locations for CPPD. The ages of the patients ranged from 31 to 86 years (average, 60.7 years). One patient was male and six were female. The temporomandibular joint was involved in three patients and the metatarsophalangeal joint of the great toe was involved in two patients. The hip joint and cervical spine were involved in one patient each. A mass or swelling with or without pain was a common symptom. None of the patients in our series had clinical or radiographic evidence of CPPD crystal deposition disease in any other joints. Roentgenograms showed calcified lesions with a granular or fluffy pattern. Histologically, the lesions showed small or large deposits of intensely basophilic calcified material containing needle shaped and rhomboid crystals with weakly positive birefringence characteristic of CPPD. Foreign body granulomatous reaction to the CPPD deposition was constantly found. Chondroid metaplasia around and in the areas of CPPD deposition was observed commonly. Some of the chondroid areas showed cellular atypia in chondrocytes suggestive of a malignant cartilage tumor. It is important to recognize this rare form of CPPD crystal deposition disease and to identify the CPPD crystals in the calcified deposits, thus avoiding the misdiagnosis of benign or malignant cartilaginous lesions.

Adult↗
PubMed1995

p53 expression and DNA ploidy of cartilage lesions.

The aim of this study was to investigate the expression of a tumor suppressor gene (p53) in cartilage lesions of bone and its relationship to their histological grade and DNA ploidy. An immunohistochemical assay for p53 and Feulgen-stained DNA preparations was subjected to computerized image analysis. Enchondromas, synovial chondromatosis, and low grade (grade I and II) chondrosarcomas were diploid. High grade (grade III) chondrosarcomas and high grade sarcomatous components of dedifferentiated chondrosarcomas were aneuploid. Well differentiated cartilaginous components of dedifferentiated chondrosarcomas were diploid. Microscopic examination showed weak focal positivity for p53 in one of 10 enchondromas one of six examples of synovial chondromatosis, and three of four low grade (grade I and II) chondrosarcomas. All three high grade (grade III) chondrosarcomas were strongly positive for p53. The high grade sarcomatous component of all four dedifferentiated chondrosarcomas was strongly positive for p53, whereas only focal weak positivity was noted in the well differentiated cartilaginous areas. These results were confirmed by quantitative computer-assisted image analysis, which showed that high grade aneuploid cartilage tumors demonstrated strikingly higher levels of p53 than did diploid low grade malignant tumors or benign cartilage lesions.

Adult↗
PubMed1995

Translocation (9;22)(q22;q12). A recurrent chromosome abnormality in extraskeletal myxoid chondrosarcoma.

Cytogenetic analysis of a case of extraskeletal myxoid chondrosarcoma revealed a reciprocal translocation between 9q and 22q in almost all metaphases analyzed. Structural rearrangements involving 9q and 22q have been reported previously in three cases of extraskeletal myxoid chondrosarcoma. The breakpoints on chromosomes 9 and 22 in the present case were in regions 9q22-q31 and 22q11-q12.2, respectively. The same breakpoints were present in all three previously reported cases. Thus, this recently identified rearrangement of 9q and 22q may serve as a critical cytogenetic parameter for the diagnosis and classification of extraskeletal myxoid chondrosarcoma, as well as being a primary chromosomal event in the course of development of this rare malignancy.

Chondrosarcoma↗
PubMed1995

A unified model for cell-killing by heat: interpretation of continuous, step-down, step-up and split heating.

We have already proposed a model for the lethal effects of heat on cells. In the model, a three-step process for cellular inactivation was hypothesized: 1) heating produces sublethal damage; 2) the damage is repaired in a certain time period; 3) the cell is inactivated when it undergoes cumulative sublethal damage to the extent that it cannot be repaired. Using the previous model, we investigated the modifications of the survival curve in 1) continuous heating, 2) step-down heating, 3) step-up heating, and 4) recovery from the thermal injury by split heating. These four phenomena were explained well with the mathematical model.

Animals↗